diff --git a/en_US.ISO8859-1/books/handbook/config/chapter.sgml b/en_US.ISO8859-1/books/handbook/config/chapter.sgml index 8d396b81bc..88bb051922 100644 --- a/en_US.ISO8859-1/books/handbook/config/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/config/chapter.sgml @@ -1,2990 +1,2990 @@ Chern Lee Written by Mike Smith Based on a tutorial written by Matt Dillon Also based on tuning(7) written by Configuration and Tuning Synopsis system configuration system optimization One of the important aspects of &os; is system configuration. Correct system configuration will help prevent headaches during future upgrades. This chapter will explain much of the &os; configuration process, including some of the parameters which can be set to tune a &os; system. After reading this chapter, you will know: How to efficiently work with file systems and swap partitions. The basics of rc.conf configuration and /usr/local/etc/rc.d startup systems. How to configure and test a network card. How to configure virtual hosts on your network devices. How to use the various configuration files in /etc. How to tune &os; using sysctl variables. How to tune disk performance and modify kernel limitations. Before reading this chapter, you should: Understand &unix; and &os; basics (). Be familiar with the basics of kernel configuration/compilation (). Initial Configuration Partition Layout partition layout /etc /var /usr Base Partitions When laying out file systems with &man.disklabel.8; or &man.sysinstall.8;, remember that hard drives transfer data faster from the outer tracks to the inner. Thus smaller and heavier-accessed file systems should be closer to the outside of the drive, while larger partitions like /usr should be placed toward the inner. It is a good idea to create partitions in a similar order to: root, swap, /var, /usr. The size of /var reflects the intended machine usage. /var is used to hold mailboxes, log files, and printer spools. Mailboxes and log files can grow to unexpected sizes depending on how many users exist and how long log files are kept. Most users would never require a gigabyte, but remember that /var/tmp must be large enough to contain packages. The /usr partition holds much of the files required to support the system, the &man.ports.7; collection (recommended) and the source code (optional). Both of which are optional at install time. At least 2 gigabytes would be recommended for this partition. When selecting partition sizes, keep the space requirements in mind. Running out of space in one partition while barely using another can be a hassle. Some users have found that &man.sysinstall.8;'s Auto-defaults partition sizer will sometimes select smaller than adequate /var and / partitions. Partition wisely and generously. Swap Partition swap sizing swap partition As a rule of thumb, the swap partition should be about double the size of system memory (RAM). For example, if the machine has 128 megabytes of memory, the swap file should be 256 megabytes. Systems with less memory may perform better with more swap. Less than 256 megabytes of swap is not recommended and memory expansion should be considered. The kernel's VM paging algorithms are tuned to perform best when the swap partition is at least two times the size of main memory. Configuring too little swap can lead to inefficiencies in the VM page scanning code and might create issues later if more memory is added. On larger systems with multiple SCSI disks (or multiple IDE disks operating on different controllers), it is recommend that a swap is configured on each drive (up to four drives). The swap partitions should be approximately the same size. The kernel can handle arbitrary sizes but internal data structures scale to 4 times the largest swap partition. Keeping the swap partitions near the same size will allow the kernel to optimally stripe swap space across disks. Large swap sizes are fine, even if swap is not used much. It might be easier to recover from a runaway program before being forced to reboot. Why Partition? Several users think a single large partition will be fine, but there are several reasons why this is a bad idea. First, each partition has different operational characteristics and separating them allows the file system to tune accordingly. For example, the root and /usr partitions are read-mostly, without much writing. While a lot of reading and writing could occur in /var and /var/tmp. By properly partitioning a system, fragmentation introduced in the smaller write heavy partitions will not bleed over into the mostly-read partitions. Keeping the write-loaded partitions closer to the disk's edge, will increase I/O performance in the partitions where it occurs the most. Now while I/O performance in the larger partitions may be needed, shifting them more toward the edge of the disk will not lead to a significant performance improvement over moving /var to the edge. Finally, there are safety concerns. A smaller, neater root partition which is mostly read-only has a greater chance of surviving a bad crash. Core Configuration rc files rc.conf The principal location for system configuration information is within /etc/rc.conf. This file contains a wide range of configuration information, principally used at system startup to configure the system. Its name directly implies this; it is configuration information for the rc* files. An administrator should make entries in the rc.conf file to override the default settings from /etc/defaults/rc.conf. The defaults file should not be copied verbatim to /etc - it contains default values, not examples. All system-specific changes should be made in the rc.conf file itself. A number of strategies may be applied in clustered applications to separate site-wide configuration from system-specific configuration in order to keep administration overhead down. The recommended approach is to place site-wide configuration into another file, such as /etc/rc.conf.site, and then include this file into /etc/rc.conf, which will contain only system-specific information. As rc.conf is read by &man.sh.1; it is trivial to achieve this. For example: rc.conf: . rc.conf.site hostname="node15.example.com" network_interfaces="fxp0 lo0" ifconfig_fxp0="inet 10.1.1.1" rc.conf.site: defaultrouter="10.1.1.254" saver="daemon" blanktime="100" The rc.conf.site file can then be distributed to every system using rsync or a similar program, while the rc.conf file remains unique. Upgrading the system using &man.sysinstall.8; or make world will not overwrite the rc.conf file, so system configuration information will not be lost. Application Configuration Typically, installed applications have their own configuration files, with their own syntax, etc. It is important that these files be kept separate from the base system, so that they may be easily located and managed by the package management tools. /usr/local/etc Typically, these files are installed in /usr/local/etc. In the case where an application has a large number of configuration files, a subdirectory will be created to hold them. Normally, when a port or package is installed, sample configuration files are also installed. These are usually identified with a .default suffix. If there are no existing configuration files for the application, they will be created by copying the .default files. For example, consider the contents of the directory /usr/local/etc/apache: -rw-r--r-- 1 root wheel 2184 May 20 1998 access.conf -rw-r--r-- 1 root wheel 2184 May 20 1998 access.conf.default -rw-r--r-- 1 root wheel 9555 May 20 1998 httpd.conf -rw-r--r-- 1 root wheel 9555 May 20 1998 httpd.conf.default -rw-r--r-- 1 root wheel 12205 May 20 1998 magic -rw-r--r-- 1 root wheel 12205 May 20 1998 magic.default -rw-r--r-- 1 root wheel 2700 May 20 1998 mime.types -rw-r--r-- 1 root wheel 2700 May 20 1998 mime.types.default -rw-r--r-- 1 root wheel 7980 May 20 1998 srm.conf -rw-r--r-- 1 root wheel 7933 May 20 1998 srm.conf.default The file sizes show that only the srm.conf file has been changed. A later update of the Apache port would not overwrite this changed file. Tom Rhodes Contributed by Starting Services services Many users choose to install third party software on &os; from the ports collection. In many of these situations it may be necessary to configure the software in a manner which will allow it to be started upon system initialization. Services, such as mail/postfix or www/apache13 are just two of the many software packages which may be started during system initialization. This section explains the procedures available for starting third party software. In &os;, most included services, such as &man.cron.8;, are started through the system start up scripts. These scripts may differ depending on &os; or vendor version; however, the most important aspect to consider is that their start up configuration can be handled through simple startup scripts. Before the advent of rcNG, applications would drop a simple start up script into the - /usr/local/etc/rc.d + /usr/local/etc/rc.d directory which would be read by the system initialization scripts. These scripts would then be executed during the latter stages of system start up. While many individuals have spent hours trying to merge the old configuration style into the new system, the fact remains that some third party utilities still require a script simply dropped into the aforementioned directory. The subtle differences in the scripts depend whether or not rcNG is being used. Prior to &os; 5.1 the old configuration style is used and in almost all cases a new style script would do just fine. While every script must meet some minimal requirements, most of the time these requirements are &os; version agnostic. Each script must have a .sh extension appended to the end and every script must be executable by the system. The latter may be achieved by using the chmod command and setting the unique permissions of 755. There should also be, at minimal, an option to start the application and an option to stop the application. The simplest start up script would probably look a little bit like this one: #!/bin/sh echo -n ' utility' case "$1" in start) /usr/local/bin/utility ;; stop) kill -9 `cat /var/run/utility.pid` ;; *) echo "Usage: `basename $0` {start|stop}" >&2 exit 64 ;; esac exit 0 This script provides for a stop and start option for the application hereto referred simply as utility. This application could then have the following line placed in /etc/rc.conf: utility_enable="YES" Could be started manually with: &prompt.root; /usr/local/etc/rc.d/utility.sh start While not all third party software requires the line in rc.conf, almost every day a new port will be modified to accept this configuration. Check the final output of the installation for more information on a specific application. Some third party software will provide start up scripts which permit the application to be used with rcNG; although, this will be discussed in the next section. Extended Application Configuration Now that &os; includes rcNG, configuration of application start up has become more optimal; indeed, it has become a bit more in depth. Using the key words discussed in the rcNG section, applications may now be set to start after certain other services for example DNS; may permit extra flags to be passed through rc.conf in place of hard coded flags in the start up script, etc. A basic script may look similar to the following: #!/bin/sh # # PROVIDE: utility # REQUIRE: DAEMON # BEFORE: LOGIN # KEYWORD: FreeBSD shutdown # # DO NOT CHANGE THESE DEFAULT VALUES HERE # SET THEM IN THE /etc/rc.conf FILE # utility_enable=${utility_enable-"NO"} utility_flags=${utility_flags-""} utility_pidfile=${utility_pidfile-"/var/run/utility.pid"} . /etc/rc.subr name="utility" rcvar=`set_rcvar` command="/usr/local/sbin/utility" load_rc_config $name pidfile="${utility_pidfile}" start_cmd="echo \"Starting ${name}.\"; /usr/bin/nice -5 ${command} ${utility_flags} ${command_args}" run_rc_command "$1" This script will ensure that the provided utility will be started before the login service but after the daemon service. It also provides a method for setting and tracking the PID, or process ID file. This new method also allows for easier manipulation of the command line arguments, inclusion of the default functions provided in /etc/rc.subr, compatibility with the &man.rcorder.8; utility and provide for easier configuration via the rc.conf file. In essence, this script could even be placed in - /etc/rc.d directory. + /etc/rc.d directory. Yet, that has the potential to upset the &man.mergemaster.8; utility when used in conjunction with software upgrades. Using Services to Start Services Other services, such as POP3 server daemons, IMAP, etc. could be started using the &man.inetd.8;. This involves installing the service utility from the ports collection with a configuration line appended to the /etc/inetd.conf file, or uncommenting one of the current configuration lines. Working with inetd and its configuration is described in depth in the inetd section. In some cases, it may be more plausible to use the &man.cron.8; daemon to start system services. This approach has a number of advantages because cron runs these processes as the crontab's file owner. This allows regular users to start and maintain some applications. The cron utility provides a unique feature, @reboot, which may be used in place of the time specification. This will cause the job to be run when &man.cron.8; is started, normally during system initialization. Tom Rhodes Contributed by Configuring the <command>cron</command> Utility cron configuration One of the most useful utilities in &os; is &man.cron.8;. The cron utility runs in the background and constantly checks the /etc/crontab file. The cron utility also checks the /var/cron/tabs directory, in search of new crontab files. These crontab files store information about specific functions which cron is supposed to perform at certain times. The cron utility uses two different types of configuration files, the system crontab and user crontabs. The only difference between these two formats is the sixth field. In the system crontab, the sixth field is the name of a user for the command to run as. This gives the system crontab the ability to run commands as any user. In a user crontab, the sixth field is the command to run, and all commands run as the user who created the crontab; this is an important security feature. User crontabs allow individual users to schedule tasks without the need for root privileges. Commands in a user's crontab run with the permissions of the user who owns the crontab. The root user can have a user crontab just like any other user. This one is different from /etc/crontab (the system crontab). Because of the system crontab, there is usually no need to create a user crontab for root. Let us take a look at the /etc/crontab file (the system crontab): # /etc/crontab - root's crontab for &os; # # $&os;: src/etc/crontab,v 1.32 2002/11/22 16:13:39 tom Exp $ # # SHELL=/bin/sh PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin HOME=/var/log # # #minute hour mday month wday who command # # */5 * * * * root /usr/libexec/atrun Like most &os; configuration files, the # character represents a comment. A comment can be placed in the file as a reminder of what and why a desired action is performed. Comments cannot be on the same line as a command or else they will be interpreted as part of the command; they must be on a new line. Blank lines are ignored. First, the environment must be defined. The equals (=) character is used to define any environment settings, as with this example where it is used for the SHELL, PATH, and HOME options. If the shell line is omitted, cron will use the default, which is sh. If the PATH variable is omitted, no default will be used and file locations will need to be absolute. If HOME is omitted, cron will use the invoking users home directory. This line defines a total of seven fields. Listed here are the values minute, hour, mday, month, wday, who, and command. These are almost all self explanatory. minute is the time in minutes the command will be run. hour is similar to the minute option, just in hours. mday stands for day of the month. month is similar to hour and minute, as it designates the month. The wday option stands for day of the week. All these fields must be numeric values, and follow the twenty-four hour clock. The who field is special, and only exists in the /etc/crontab file. This field specifies which user the command should be run as. When a user installs his or her crontab file, they will not have this option. Finally, the command option is listed. This is the last field, so naturally it should designate the command to be executed. This last line will define the values discussed above. Notice here we have a */5 listing, followed by several more * characters. These * characters mean first-last, and can be interpreted as every time. So, judging by this line, it is apparent that the atrun command is to be invoked by root every five minutes regardless of what day or month it is. For more information on the atrun command, see the &man.atrun.8; manual page. Commands can have any number of flags passed to them; however, commands which extend to multiple lines need to be broken with the backslash \ continuation character. This is the basic set up for every crontab file, although there is one thing different about this one. Field number six, where we specified the username, only exists in the system /etc/crontab file. This field should be omitted for individual user crontab files. Installing a Crontab You must not use the procedure described here to edit/install the system crontab. Simply use your favorite editor: the cron utility will notice that the file has changed and immediately begin using the updated version. See this FAQ entry for more information. To install a freshly written user crontab, first use your favorite editor to create a file in the proper format, and then use the crontab utility. The most common usage is: &prompt.user; crontab crontab-file In this example, crontab-file is the filename of a crontab that was previously created. There is also an option to list installed crontab files: just pass the option to crontab and look over the output. For users who wish to begin their own crontab file from scratch, without the use of a template, the crontab -e option is available. This will invoke the selected editor with an empty file. When the file is saved, it will be automatically installed by the crontab command. If you later want to remove your user crontab completely, use crontab with the option. Tom Rhodes Contributed by Using rc under FreeBSD 5.X rcNG &os; has recently integrated the NetBSD rc.d system for system initialization. Users should notice the files listed in the /etc/rc.d directory. Many of these files are for basic services which can be controlled with the , , and options. For instance, &man.sshd.8; can be restarted with the following command: &prompt.root; /etc/rc.d/sshd restart This procedure is similar for other services. Of course, services are usually started automatically as specified in &man.rc.conf.5;. For example, enabling the Network Address Translation daemon at startup is as simple as adding the following line to /etc/rc.conf: natd_enable="YES" If a line is already present, then simply change the to . The rc scripts will automatically load any other dependent services during the next reboot, as described below. Since the rc.d system is primarily intended to start/stop services at system startup/shutdown time, the standard , and options will only perform their action if the appropriate /etc/rc.conf variables are set. For instance the above sshd restart command will only work if sshd_enable is set to in /etc/rc.conf. To , or a service regardless of the settings in /etc/rc.conf, the commands should be prefixed with force. For instance to restart sshd regardless of the current /etc/rc.conf setting, execute the following command: &prompt.root; /etc/rc.d/sshd forcerestart It is easy to check if a service is enabled in /etc/rc.conf by running the appropriate rc.d script with the option . Thus, an administrator can check that sshd is in fact enabled in /etc/rc.conf by running: &prompt.root; /etc/rc.d/sshd rcvar # sshd $sshd_enable=YES The second line (# sshd) is the output from the sshd command, not a root console. To determine if a service is running, a option is available. For instance to verify that sshd is actually started: &prompt.root; /etc/rc.d/sshd status sshd is running as pid 433. It is also possible to a service. This will attempt to send a signal to an individual service, forcing the service to reload its configuration files. In most cases this means sending the service a SIGHUP signal. The rcNG structure is not only used for network services, it also contributes to most of the system initialization. For instance, consider the bgfsck file. When this script is executed, it will print out the following message: Starting background file system checks in 60 seconds. Therefore this file is used for background file system checks, which are done only during system initialization. Many system services depend on other services to function properly. For example, NIS and other RPC-based services may fail to start until after the rpcbind (portmapper) service has started. To resolve this issue, information about dependencies and other meta-data is included in the comments at the top of each startup script. The &man.rcorder.8; program is then used to parse these comments during system initialization to determine the order in which system services should be invoked to satisfy the dependencies. The following words may be included at the top of each startup file: PROVIDE: Specifies the services this file provides. REQUIRE: Lists services which are required for this service. This file will run after the specified services. BEFORE: Lists services which depend on this service. This file will run before the specified services. KEYWORD: &os; or NetBSD. This is used for *BSD dependent features. By using this method, an administrator can easily control system services without the hassle of runlevels like some other &unix; operating systems. Additional information about the &os; 5.X rc.d system can be found in the &man.rc.8; and &man.rc.subr.8; manual pages. Marc Fonvieille Contributed by Setting Up Network Interface Cards network card configuration Nowadays we can not think about a computer without thinking about a network connection. Adding and configuring a network card is a common task for any &os; administrator. Locating the Correct Driver network card configuration locating the driver Before you begin, you should know the model of the card you have, the chip it uses, and whether it is a PCI or ISA card. &os; supports a wide variety of both PCI and ISA cards. Check the Hardware Compatibility List for your release to see if your card is supported. Once you are sure your card is supported, you need to determine the proper driver for the card. The file /usr/src/sys/i386/conf/LINT will give you the list of network interfaces drivers with some information about the supported chipsets/cards. If you have doubts about which driver is the correct one, read the manual page of the driver. The manual page will give you more information about the supported hardware and even the possible problems that could occur. If you own a common card, most of the time you will not have to look very hard for a driver. Drivers for common network cards are present in the GENERIC kernel, so your card should show up during boot, like so: dc0: <82c169 PNIC 10/100BaseTX> port 0xa000-0xa0ff mem 0xd3800000-0xd38 000ff irq 15 at device 11.0 on pci0 dc0: Ethernet address: 00:a0:cc:da:da:da miibus0: <MII bus> on dc0 ukphy0: <Generic IEEE 802.3u media interface> on miibus0 ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto dc1: <82c169 PNIC 10/100BaseTX> port 0x9800-0x98ff mem 0xd3000000-0xd30 000ff irq 11 at device 12.0 on pci0 dc1: Ethernet address: 00:a0:cc:da:da:db miibus1: <MII bus> on dc1 ukphy1: <Generic IEEE 802.3u media interface> on miibus1 ukphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto In this example, we see that two cards using the &man.dc.4; driver are present on the system. To use your network card, you will need to load the proper driver. This may be accomplished in one of two ways. The easiest way is to simply load a kernel module for your network card with &man.kldload.8;. A module is not available for all network card drivers (ISA cards and cards using the &man.ed.4; driver, for example). Alternatively, you may statically compile the support for your card into your kernel. Check /usr/src/sys/i386/conf/LINT and the manual page of the driver to know what to add in your kernel configuration file. For more information about recompiling your kernel, please see . If your card was detected at boot by your kernel (GENERIC) you do not have to build a new kernel. Configuring the Network Card network card configuration configuration Once the right driver is loaded for the network card, the card needs to be configured. As with many other things, the network card may have been configured at installation time by sysinstall. To display the configuration for the network interfaces on your system, enter the following command: &prompt.user; ifconfig dc0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 192.168.1.3 netmask 0xffffff00 broadcast 192.168.1.255 ether 00:a0:cc:da:da:da media: Ethernet autoselect (100baseTX <full-duplex>) status: active dc1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.0.1 netmask 0xffffff00 broadcast 10.0.0.255 ether 00:a0:cc:da:da:db media: Ethernet 10baseT/UTP status: no carrier lp0: flags=8810<POINTOPOINT,SIMPLEX,MULTICAST> mtu 1500 lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet 127.0.0.1 netmask 0xff000000 tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 Old versions of &os; may require the option following &man.ifconfig.8;, for more details about the correct syntax of &man.ifconfig.8;, please refer to the manual page. Note also that entries concerning IPv6 (inet6 etc.) were omitted in this example. In this example, the following devices were displayed: dc0: The first Ethernet interface dc1: The second Ethernet interface lp0: The parallel port interface lo0: The loopback device tun0: The tunnel device used by ppp &os; uses the driver name followed by the order in which one the card is detected at the kernel boot to name the network card. For example sis2 would be the third network card on the system using the &man.sis.4; driver. In this example, the dc0 device is up and running. The key indicators are: UP means that the card is configured and ready. The card has an Internet (inet) address (in this case 192.168.1.3). It has a valid subnet mask (netmask; 0xffffff00 is the same as 255.255.255.0). It has a valid broadcast address (in this case, 192.168.1.255). The MAC address of the card (ether) is 00:a0:cc:da:da:da The physical media selection is on autoselection mode (media: Ethernet autoselect (100baseTX <full-duplex>)). We see that dc1 was configured to run with 10baseT/UTP media. For more information on available media types for a driver, please refer to its manual page. The status of the link (status) is active, i.e. the carrier is detected. For dc1, we see status: no carrier. This is normal when an Ethernet cable is not plugged into the card. If the &man.ifconfig.8; output had shown something similar to: dc0: flags=8843<BROADCAST,SIMPLEX,MULTICAST> mtu 1500 ether 00:a0:cc:da:da:da it would indicate the card has not been configured. To configure your card, you need root privileges. The network card configuration can be done from the command line with &man.ifconfig.8; but you would have to do it after each reboot of the system. The file /etc/rc.conf is where to add the network card's configuration. Open /etc/rc.conf in your favorite editor. You need to add a line for each network card present on the system, for example in our case, we added these lines: ifconfig_dc0="inet 192.168.1.3 netmask 255.255.255.0" ifconfig_dc1="inet 10.0.0.1 netmask 255.255.255.0 media 10baseT/UTP" You have to replace dc0, dc1, and so on, with the correct device for your cards, and the addresses with the proper ones. You should read the card driver and &man.ifconfig.8; manual pages for more details about the allowed options and also &man.rc.conf.5; manual page for more information on the syntax of /etc/rc.conf. If you configured the network during installation, some lines about the network card(s) may be already present. Double check /etc/rc.conf before adding any lines. You will also have to edit the file /etc/hosts to add the names and the IP addresses of various machines of the LAN, if they are not already there. For more information please refer to &man.hosts.5; and to /usr/share/examples/etc/hosts. Testing and Troubleshooting Once you have made the necessary changes in /etc/rc.conf, you should reboot your system. This will allow the change(s) to the interface(s) to be applied, and verify that the system restarts without any configuration errors. Once the system has been rebooted, you should test the network interfaces. Testing the Ethernet Card network card configuration testing the card To verify that an Ethernet card is configured correctly, you have to try two things. First, ping the interface itself, and then ping another machine on the LAN. First test the local interface: &prompt.user; ping -c5 192.168.1.3 PING 192.168.1.3 (192.168.1.3): 56 data bytes 64 bytes from 192.168.1.3: icmp_seq=0 ttl=64 time=0.082 ms 64 bytes from 192.168.1.3: icmp_seq=1 ttl=64 time=0.074 ms 64 bytes from 192.168.1.3: icmp_seq=2 ttl=64 time=0.076 ms 64 bytes from 192.168.1.3: icmp_seq=3 ttl=64 time=0.108 ms 64 bytes from 192.168.1.3: icmp_seq=4 ttl=64 time=0.076 ms --- 192.168.1.3 ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max/stddev = 0.074/0.083/0.108/0.013 ms Now we have to ping another machine on the LAN: &prompt.user; ping -c5 192.168.1.2 PING 192.168.1.2 (192.168.1.2): 56 data bytes 64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=0.726 ms 64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.766 ms 64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.700 ms 64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=0.747 ms 64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=0.704 ms --- 192.168.1.2 ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max/stddev = 0.700/0.729/0.766/0.025 ms You could also use the machine name instead of 192.168.1.2 if you have set up the /etc/hosts file. Troubleshooting network card configuration troubleshooting Troubleshooting hardware and software configurations is always a pain, and a pain which can be alleviated by checking the simple things first. Is your network cable plugged in? Have you properly configured the network services? Did you configure the firewall correctly? Is the card you are using supported by &os;? Always check the hardware notes before sending off a bug report. Update your version of &os; to the latest STABLE version. Check the mailing list archives, or perhaps search the Internet. If the card works, yet performance is poor, it would be worthwhile to read over the &man.tuning.7; manual page. You can also check the network configuration as incorrect network settings can cause slow connections. Some users experience one or two device timeout messages, which is normal for some cards. If they continue, or are bothersome, you may wish to be sure the device is not conflicting with another device. Double check the cable connections. Perhaps you may just need to get another card. At times, users see a few watchdog timeout errors. The first thing to do here is to check your network cable. Many cards require a PCI slot which supports Bus Mastering. On some old motherboards, only one PCI slot allows it (usually slot 0). Check the network card and the motherboard documentation to determine if that may be the problem. No route to host messages occur if the system is unable to route a packet to the destination host. This can happen if no default route is specified, or if a cable is unplugged. Check the output of netstat -rn and make sure there is a valid route to the host you are trying to reach. If there is not, read on to . ping: sendto: Permission denied error messages are often caused by a misconfigured firewall. If ipfw is enabled in the kernel but no rules have been defined, then the default policy is to deny all traffic, even ping requests! Read on to for more information. Sometimes performance of the card is poor, or below average. In these cases it is best to set the media selection mode from autoselect to the correct media selection. While this usually works for most hardware, it may not resolve this issue for everyone. Again, check all the network settings, and read over the &man.tuning.7; manual page. Virtual Hosts virtual hosts IP aliases A very common use of &os; is virtual site hosting, where one server appears to the network as many servers. This is achieved by assigning multiple network addresses to a single interface. A given network interface has one real address, and may have any number of alias addresses. These aliases are normally added by placing alias entries in /etc/rc.conf. An alias entry for the interface fxp0 looks like: ifconfig_fxp0_alias0="inet xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx" Note that alias entries must start with alias0 and proceed upwards in order, (for example, _alias1, _alias2, and so on). The configuration process will stop at the first missing number. The calculation of alias netmasks is important, but fortunately quite simple. For a given interface, there must be one address which correctly represents the network's netmask. Any other addresses which fall within this network must have a netmask of all 1s (expressed as either 255.255.255.255 or 0xffffffff). For example, consider the case where the fxp0 interface is connected to two networks, the 10.1.1.0 network with a netmask of 255.255.255.0 and the 202.0.75.16 network with a netmask of 255.255.255.240. We want the system to appear at 10.1.1.1 through 10.1.1.5 and at 202.0.75.17 through 202.0.75.20. As noted above, only the first address in a given network range (in this case, 10.0.1.1 and 202.0.75.17) should have a real netmask; all the rest (10.1.1.2 through 10.1.1.5 and 202.0.75.18 through 202.0.75.20) must be configured with a netmask of 255.255.255.255. The following entries configure the adapter correctly for this arrangement: ifconfig_fxp0="inet 10.1.1.1 netmask 255.255.255.0" ifconfig_fxp0_alias0="inet 10.1.1.2 netmask 255.255.255.255" ifconfig_fxp0_alias1="inet 10.1.1.3 netmask 255.255.255.255" ifconfig_fxp0_alias2="inet 10.1.1.4 netmask 255.255.255.255" ifconfig_fxp0_alias3="inet 10.1.1.5 netmask 255.255.255.255" ifconfig_fxp0_alias4="inet 202.0.75.17 netmask 255.255.255.240" ifconfig_fxp0_alias5="inet 202.0.75.18 netmask 255.255.255.255" ifconfig_fxp0_alias6="inet 202.0.75.19 netmask 255.255.255.255" ifconfig_fxp0_alias7="inet 202.0.75.20 netmask 255.255.255.255" Configuration Files <filename>/etc</filename> Layout There are a number of directories in which configuration information is kept. These include: /etc Generic system configuration information; data here is system-specific. /etc/defaults Default versions of system configuration files. /etc/mail Extra &man.sendmail.8; configuration, other MTA configuration files. /etc/ppp Configuration for both user- and kernel-ppp programs. /etc/namedb Default location for &man.named.8; data. Normally named.conf and zone files are stored here. /usr/local/etc Configuration files for installed applications. May contain per-application subdirectories. /usr/local/etc/rc.d Start/stop scripts for installed applications. /var/db Automatically generated system-specific database files, such as the package database, the locate database, and so on Hostnames hostname DNS <filename>/etc/resolv.conf</filename> resolv.conf /etc/resolv.conf dictates how &os;'s resolver accesses the Internet Domain Name System (DNS). The most common entries to resolv.conf are: nameserver The IP address of a name server the resolver should query. The servers are queried in the order listed with a maximum of three. search Search list for hostname lookup. This is normally determined by the domain of the local hostname. domain The local domain name. A typical resolv.conf: search example.com nameserver 147.11.1.11 nameserver 147.11.100.30 Only one of the search and domain options should be used. If you are using DHCP, &man.dhclient.8; usually rewrites resolv.conf with information received from the DHCP server. <filename>/etc/hosts</filename> hosts /etc/hosts is a simple text database reminiscent of the old Internet. It works in conjunction with DNS and NIS providing name to IP address mappings. Local computers connected via a LAN can be placed in here for simplistic naming purposes instead of setting up a &man.named.8; server. Additionally, /etc/hosts can be used to provide a local record of Internet names, reducing the need to query externally for commonly accessed names. # $&os;$ # # Host Database # This file should contain the addresses and aliases # for local hosts that share this file. # In the presence of the domain name service or NIS, this file may # not be consulted at all; see /etc/nsswitch.conf for the resolution order. # # ::1 localhost localhost.my.domain myname.my.domain 127.0.0.1 localhost localhost.my.domain myname.my.domain # # Imaginary network. #10.0.0.2 myname.my.domain myname #10.0.0.3 myfriend.my.domain myfriend # # According to RFC 1918, you can use the following IP networks for # private nets which will never be connected to the Internet: # # 10.0.0.0 - 10.255.255.255 # 172.16.0.0 - 172.31.255.255 # 192.168.0.0 - 192.168.255.255 # # In case you want to be able to connect to the Internet, you need # real official assigned numbers. PLEASE PLEASE PLEASE do not try # to invent your own network numbers but instead get one from your # network provider (if any) or from the Internet Registry (ftp to # rs.internic.net, directory `/templates'). # /etc/hosts takes on the simple format of: [Internet address] [official hostname] [alias1] [alias2] ... For example: 10.0.0.1 myRealHostname.example.com myRealHostname foobar1 foobar2 Consult &man.hosts.5; for more information. Log File Configuration log files <filename>syslog.conf</filename> syslog.conf syslog.conf is the configuration file for the &man.syslogd.8; program. It indicates which types of syslog messages are logged to particular log files. # $&os;$ # # Spaces ARE valid field separators in this file. However, # other *nix-like systems still insist on using tabs as field # separators. If you are sharing this file between systems, you # may want to use only tabs as field separators here. # Consult the syslog.conf(5) manual page. *.err;kern.debug;auth.notice;mail.crit /dev/console *.notice;kern.debug;lpr.info;mail.crit;news.err /var/log/messages security.* /var/log/security mail.info /var/log/maillog lpr.info /var/log/lpd-errs cron.* /var/log/cron *.err root *.notice;news.err root *.alert root *.emerg * # uncomment this to log all writes to /dev/console to /var/log/console.log #console.info /var/log/console.log # uncomment this to enable logging of all log messages to /var/log/all.log #*.* /var/log/all.log # uncomment this to enable logging to a remote log host named loghost #*.* @loghost # uncomment these if you're running inn # news.crit /var/log/news/news.crit # news.err /var/log/news/news.err # news.notice /var/log/news/news.notice !startslip *.* /var/log/slip.log !ppp *.* /var/log/ppp.log Consult the &man.syslog.conf.5; manual page for more information. <filename>newsyslog.conf</filename> newsyslog.conf newsyslog.conf is the configuration file for &man.newsyslog.8;, a program that is normally scheduled to run by &man.cron.8;. &man.newsyslog.8; determines when log files require archiving or rearranging. logfile is moved to logfile.0, logfile.0 is moved to logfile.1, and so on. Alternatively, the log files may be archived in &man.gzip.1; format causing them to be named: logfile.0.gz, logfile.1.gz, and so on. newsyslog.conf indicates which log files are to be managed, how many are to be kept, and when they are to be touched. Log files can be rearranged and/or archived when they have either reached a certain size, or at a certain periodic time/date. # configuration file for newsyslog # $&os;$ # # filename [owner:group] mode count size when [ZB] [/pid_file] [sig_num] /var/log/cron 600 3 100 * Z /var/log/amd.log 644 7 100 * Z /var/log/kerberos.log 644 7 100 * Z /var/log/lpd-errs 644 7 100 * Z /var/log/maillog 644 7 * @T00 Z /var/log/sendmail.st 644 10 * 168 B /var/log/messages 644 5 100 * Z /var/log/all.log 600 7 * @T00 Z /var/log/slip.log 600 3 100 * Z /var/log/ppp.log 600 3 100 * Z /var/log/security 600 10 100 * Z /var/log/wtmp 644 3 * @01T05 B /var/log/daily.log 640 7 * @T00 Z /var/log/weekly.log 640 5 1 $W6D0 Z /var/log/monthly.log 640 12 * $M1D0 Z /var/log/console.log 640 5 100 * Z Consult the &man.newsyslog.8; manual page for more information. <filename>sysctl.conf</filename> sysctl.conf sysctl sysctl.conf looks much like rc.conf. Values are set in a variable=value form. The specified values are set after the system goes into multi-user mode. Not all variables are settable in this mode. A sample sysctl.conf turning off logging of fatal signal exits and letting Linux programs know they are really running under &os;: kern.logsigexit=0 # Do not log fatal signal exits (e.g. sig 11) compat.linux.osname=&os; compat.linux.osrelease=4.3-STABLE Tuning with sysctl sysctl tuning with sysctl &man.sysctl.8; is an interface that allows you to make changes to a running &os; system. This includes many advanced options of the TCP/IP stack and virtual memory system that can dramatically improve performance for an experienced system administrator. Over five hundred system variables can be read and set using &man.sysctl.8;. At its core, &man.sysctl.8; serves two functions: to read and to modify system settings. To view all readable variables: &prompt.user; sysctl -a To read a particular variable, for example, kern.maxproc: &prompt.user; sysctl kern.maxproc kern.maxproc: 1044 To set a particular variable, use the intuitive variable=value syntax: &prompt.root; sysctl kern.maxfiles=5000 kern.maxfiles: 2088 -> 5000 Settings of sysctl variables are usually either strings, numbers, or booleans (a boolean being 1 for yes or a 0 for no). If you want to set automatically some variables each time the machine boots, add them to the /etc/sysctl.conf file. For more information see the &man.sysctl.conf.5; manual page and the . Tom Rhodes Contributed by &man.sysctl.8; Read-only In some cases it may be desirable to modify read-only &man.sysctl.8; values. While this is not recommended, it is also sometimes unavoidable. For instance on some laptop models the &man.cardbus.4; device will not probe memory ranges, and fail with errors which look similar to: cbb0: Could not map register memory device_probe_and_attach: cbb0 attach returned 12 Cases like the one above usually require the modification of some default &man.sysctl.8; settings which are set read only. To overcome these situations a user can put &man.sysctl.8; OIDs in their local /boot/loader.conf. Default settings are located in the /boot/defaults/loader.conf file. Fixing the problem mentioned above would require a user to set in the aforementioned file. Now &man.cardbus.4; will work properly. Tuning Disks Sysctl Variables <varname>vfs.vmiodirenable</varname> vfs.vmiodirenable The vfs.vmiodirenable sysctl variable may be set to either 0 (off) or 1 (on); it is 1 by default. This variable controls how directories are cached by the system. Most directories are small, using just a single fragment (typically 1 K) in the file system and less (typically 512 bytes) in the buffer cache. With this variable turned off (to 0), the buffer cache will only cache a fixed number of directories even if you have a huge amount of memory. When turned on (to 1), this sysctl allows the buffer cache to use the VM Page Cache to cache the directories, making all the memory available for caching directories. However, the minimum in-core memory used to cache a directory is the physical page size (typically 4 K) rather than 512  bytes. We recommend keeping this option on if you are running any services which manipulate large numbers of files. Such services can include web caches, large mail systems, and news systems. Keeping this option on will generally not reduce performance even with the wasted memory but you should experiment to find out. <varname>vfs.write_behind</varname> vfs.write_behind The vfs.write_behind sysctl variable defaults to 1 (on). This tells the file system to issue media writes as full clusters are collected, which typically occurs when writing large sequential files. The idea is to avoid saturating the buffer cache with dirty buffers when it would not benefit I/O performance. However, this may stall processes and under certain circumstances you may wish to turn it off. <varname>vfs.hirunningspace</varname> vfs.hirunningspace The vfs.hirunningspace sysctl variable determines how much outstanding write I/O may be queued to disk controllers system-wide at any given instance. The default is usually sufficient but on machines with lots of disks you may want to bump it up to four or five megabytes. Note that setting too high a value (exceeding the buffer cache's write threshold) can lead to extremely bad clustering performance. Do not set this value arbitrarily high! Higher write values may add latency to reads occurring at the same time. There are various other buffer-cache and VM page cache related sysctls. We do not recommend modifying these values. As of &os; 4.3, the VM system does an extremely good job of automatically tuning itself. <varname>vm.swap_idle_enabled</varname> vm.swap_idle_enabled The vm.swap_idle_enabled sysctl variable is useful in large multi-user systems where you have lots of users entering and leaving the system and lots of idle processes. Such systems tend to generate a great deal of continuous pressure on free memory reserves. Turning this feature on and tweaking the swapout hysteresis (in idle seconds) via vm.swap_idle_threshold1 and vm.swap_idle_threshold2 allows you to depress the priority of memory pages associated with idle processes more quickly then the normal pageout algorithm. This gives a helping hand to the pageout daemon. Do not turn this option on unless you need it, because the tradeoff you are making is essentially pre-page memory sooner rather than later; thus eating more swap and disk bandwidth. In a small system this option will have a determinable effect but in a large system that is already doing moderate paging this option allows the VM system to stage whole processes into and out of memory easily. <varname>hw.ata.wc</varname> hw.ata.wc &os; 4.3 flirted with turning off IDE write caching. This reduced write bandwidth to IDE disks but was considered necessary due to serious data consistency issues introduced by hard drive vendors. The problem is that IDE drives lie about when a write completes. With IDE write caching turned on, IDE hard drives not only write data to disk out of order, but will sometimes delay writing some blocks indefinitely when under heavy disk loads. A crash or power failure may cause serious file system corruption. &os;'s default was changed to be safe. Unfortunately, the result was such a huge performance loss that we changed write caching back to on by default after the release. You should check the default on your system by observing the hw.ata.wc sysctl variable. If IDE write caching is turned off, you can turn it back on by setting the kernel variable back to 1. This must be done from the boot loader at boot time. Attempting to do it after the kernel boots will have no effect. For more information, please see &man.ata.4;. <literal>SCSI_DELAY</literal> (<varname>kern.cam.scsi_delay</varname>) SCSI_DELAY kern.cam.scsi_delay The SCSI_DELAY kernel config may be used to reduce system boot times. The defaults are fairly high and can be responsible for 15 seconds of delay in the boot process. Reducing it to 5 seconds usually works (especially with modern drives). Newer versions of &os; (5.0 and higher) should use the kern.cam.scsi_delay boot time tunable. The tunable, and kernel config option accept values in terms of milliseconds and not seconds. Soft Updates Soft Updates tunefs The &man.tunefs.8; program can be used to fine-tune a file system. This program has many different options, but for now we are only concerned with toggling Soft Updates on and off, which is done by: &prompt.root; tunefs -n enable /filesystem &prompt.root; tunefs -n disable /filesystem A filesystem cannot be modified with &man.tunefs.8; while it is mounted. A good time to enable Soft Updates is before any partitions have been mounted, in single-user mode. As of &os; 4.5, it is possible to enable Soft Updates at filesystem creation time, through use of the -U option to &man.newfs.8;. Soft Updates drastically improves meta-data performance, mainly file creation and deletion, through the use of a memory cache. We recommend to use Soft Updates on all of your file systems. There are two downsides to Soft Updates that you should be aware of: First, Soft Updates guarantees filesystem consistency in the case of a crash but could very easily be several seconds (even a minute!) behind updating the physical disk. If your system crashes you may lose more work than otherwise. Secondly, Soft Updates delays the freeing of filesystem blocks. If you have a filesystem (such as the root filesystem) which is almost full, performing a major update, such as make installworld, can cause the filesystem to run out of space and the update to fail. More Details about Soft Updates Soft Updates details There are two traditional approaches to writing a file systems meta-data back to disk. (Meta-data updates are updates to non-content data like inodes or directories.) Historically, the default behavior was to write out meta-data updates synchronously. If a directory had been changed, the system waited until the change was actually written to disk. The file data buffers (file contents) were passed through the buffer cache and backed up to disk later on asynchronously. The advantage of this implementation is that it operates safely. If there is a failure during an update, the meta-data are always in a consistent state. A file is either created completely or not at all. If the data blocks of a file did not find their way out of the buffer cache onto the disk by the time of the crash, &man.fsck.8; is able to recognize this and repair the filesystem by setting the file length to 0. Additionally, the implementation is clear and simple. The disadvantage is that meta-data changes are slow. An rm -r, for instance, touches all the files in a directory sequentially, but each directory change (deletion of a file) will be written synchronously to the disk. This includes updates to the directory itself, to the inode table, and possibly to indirect blocks allocated by the file. Similar considerations apply for unrolling large hierarchies (tar -x). The second case is asynchronous meta-data updates. This is the default for Linux/ext2fs and mount -o async for *BSD ufs. All meta-data updates are simply being passed through the buffer cache too, that is, they will be intermixed with the updates of the file content data. The advantage of this implementation is there is no need to wait until each meta-data update has been written to disk, so all operations which cause huge amounts of meta-data updates work much faster than in the synchronous case. Also, the implementation is still clear and simple, so there is a low risk for bugs creeping into the code. The disadvantage is that there is no guarantee at all for a consistent state of the filesystem. If there is a failure during an operation that updated large amounts of meta-data (like a power failure, or someone pressing the reset button), the filesystem will be left in an unpredictable state. There is no opportunity to examine the state of the filesystem when the system comes up again; the data blocks of a file could already have been written to the disk while the updates of the inode table or the associated directory were not. It is actually impossible to implement a fsck which is able to clean up the resulting chaos (because the necessary information is not available on the disk). If the filesystem has been damaged beyond repair, the only choice is to use &man.newfs.8; on it and restore it from backup. The usual solution for this problem was to implement dirty region logging, which is also referred to as journaling, although that term is not used consistently and is occasionally applied to other forms of transaction logging as well. Meta-data updates are still written synchronously, but only into a small region of the disk. Later on they will be moved to their proper location. Because the logging area is a small, contiguous region on the disk, there are no long distances for the disk heads to move, even during heavy operations, so these operations are quicker than synchronous updates. Additionally the complexity of the implementation is fairly limited, so the risk of bugs being present is low. A disadvantage is that all meta-data are written twice (once into the logging region and once to the proper location) so for normal work, a performance pessimization might result. On the other hand, in case of a crash, all pending meta-data operations can be quickly either rolled-back or completed from the logging area after the system comes up again, resulting in a fast filesystem startup. Kirk McKusick, the developer of Berkeley FFS, solved this problem with Soft Updates: all pending meta-data updates are kept in memory and written out to disk in a sorted sequence (ordered meta-data updates). This has the effect that, in case of heavy meta-data operations, later updates to an item catch the earlier ones if the earlier ones are still in memory and have not already been written to disk. So all operations on, say, a directory are generally performed in memory before the update is written to disk (the data blocks are sorted according to their position so that they will not be on the disk ahead of their meta-data). If the system crashes, this causes an implicit log rewind: all operations which did not find their way to the disk appear as if they had never happened. A consistent filesystem state is maintained that appears to be the one of 30 to 60 seconds earlier. The algorithm used guarantees that all resources in use are marked as such in their appropriate bitmaps: blocks and inodes. After a crash, the only resource allocation error that occurs is that resources are marked as used which are actually free. &man.fsck.8; recognizes this situation, and frees the resources that are no longer used. It is safe to ignore the dirty state of the filesystem after a crash by forcibly mounting it with mount -f. In order to free resources that may be unused, &man.fsck.8; needs to be run at a later time. This is the idea behind the background fsck: at system startup time, only a snapshot of the filesystem is recorded. The fsck can be run later on. All file systems can then be mounted dirty, so the system startup proceeds in multiuser mode. Then, background fscks will be scheduled for all file systems where this is required, to free resources that may be unused. (File systems that do not use Soft Updates still need the usual foreground fsck though.) The advantage is that meta-data operations are nearly as fast as asynchronous updates (i.e. faster than with logging, which has to write the meta-data twice). The disadvantages are the complexity of the code (implying a higher risk for bugs in an area that is highly sensitive regarding loss of user data), and a higher memory consumption. Additionally there are some idiosyncrasies one has to get used to. After a crash, the state of the filesystem appears to be somewhat older. In situations where the standard synchronous approach would have caused some zero-length files to remain after the fsck, these files do not exist at all with a Soft Updates filesystem because neither the meta-data nor the file contents have ever been written to disk. Disk space is not released until the updates have been written to disk, which may take place some time after running rm. This may cause problems when installing large amounts of data on a filesystem that does not have enough free space to hold all the files twice. Tuning Kernel Limits tuning kernel limits File/Process Limits <varname>kern.maxfiles</varname> kern.maxfiles kern.maxfiles can be raised or lowered based upon your system requirements. This variable indicates the maximum number of file descriptors on your system. When the file descriptor table is full, file: table is full will show up repeatedly in the system message buffer, which can be viewed with the dmesg command. Each open file, socket, or fifo uses one file descriptor. A large-scale production server may easily require many thousands of file descriptors, depending on the kind and number of services running concurrently. kern.maxfile's default value is dictated by the option in your kernel configuration file. kern.maxfiles grows proportionally to the value of . When compiling a custom kernel, it is a good idea to set this kernel configuration option according to the uses of your system. From this number, the kernel is given most of its pre-defined limits. Even though a production machine may not actually have 256 users connected at once, the resources needed may be similar to a high-scale web server. As of &os; 4.5, setting to 0 in your kernel configuration file will choose a reasonable default value based on the amount of RAM present in your system. <varname>kern.ipc.somaxconn</varname> kern.ipc.somaxconn The kern.ipc.somaxconn sysctl variable limits the size of the listen queue for accepting new TCP connections. The default value of 128 is typically too low for robust handling of new connections in a heavily loaded web server environment. For such environments, it is recommended to increase this value to 1024 or higher. The service daemon may itself limit the listen queue size (e.g. &man.sendmail.8;, or Apache) but will often have a directive in its configuration file to adjust the queue size. Large listen queues also do a better job of avoiding Denial of Service (DoS) attacks. Network Limits The NMBCLUSTERS kernel configuration option dictates the amount of network Mbufs available to the system. A heavily-trafficked server with a low number of Mbufs will hinder &os;'s ability. Each cluster represents approximately 2 K of memory, so a value of 1024 represents 2 megabytes of kernel memory reserved for network buffers. A simple calculation can be done to figure out how many are needed. If you have a web server which maxes out at 1000 simultaneous connections, and each connection eats a 16 K receive and 16 K send buffer, you need approximately 32 MB worth of network buffers to cover the web server. A good rule of thumb is to multiply by 2, so 2x32 MB / 2 KB = 64 MB / 2 kB = 32768. We recommend values between 4096 and 32768 for machines with greater amounts of memory. Under no circumstances should you specify an arbitrarily high value for this parameter as it could lead to a boot time crash. The option to &man.netstat.1; may be used to observe network cluster use. kern.ipc.nmbclusters loader tunable should be used to tune this at boot time. Only older versions of &os; will require you to use the NMBCLUSTERS kernel &man.config.8; option. For busy servers that make extensive use of the &man.sendfile.2; system call, it may be necessary to increase the number of &man.sendfile.2; buffers via the NSFBUFS kernel configuration option or by setting its value in /boot/loader.conf (see &man.loader.8; for details). A common indicator that this parameter needs to be adjusted is when processes are seen in the sfbufa state. The sysctl variable kern.ipc.nsfbufs is a read-only glimpse at the kernel configured variable. This parameter nominally scales with kern.maxusers, however it may be necessary to tune accordingly. Even though a socket has been marked as non-blocking, calling &man.sendfile.2; on the non-blocking socket may result in the &man.sendfile.2; call blocking until enough struct sf_buf's are made available. <varname>net.inet.ip.portrange.*</varname> net.inet.ip.portrange.* The net.inet.ip.portrange.* sysctl variables control the port number ranges automatically bound to TCP and UDP sockets. There are three ranges: a low range, a default range, and a high range. Most network programs use the default range which is controlled by the net.inet.ip.portrange.first and net.inet.ip.portrange.last, which default to 1024 and 5000, respectively. Bound port ranges are used for outgoing connections, and it is possible to run the system out of ports under certain circumstances. This most commonly occurs when you are running a heavily loaded web proxy. The port range is not an issue when running servers which handle mainly incoming connections, such as a normal web server, or has a limited number of outgoing connections, such as a mail relay. For situations where you may run yourself out of ports, it is recommended to increase net.inet.ip.portrange.last modestly. A value of 10000, 20000 or 30000 may be reasonable. You should also consider firewall effects when changing the port range. Some firewalls may block large ranges of ports (usually low-numbered ports) and expect systems to use higher ranges of ports for outgoing connections — for this reason it is recommended that net.inet.ip.portrange.first be lowered. TCP Bandwidth Delay Product TCP Bandwidth Delay Product Limiting net.inet.tcp.inflight_enable The TCP Bandwidth Delay Product Limiting is similar to TCP/Vegas in NetBSD. It can be enabled by setting net.inet.tcp.inflight_enable sysctl variable to 1. The system will attempt to calculate the bandwidth delay product for each connection and limit the amount of data queued to the network to just the amount required to maintain optimum throughput. This feature is useful if you are serving data over modems, Gigabit Ethernet, or even high speed WAN links (or any other link with a high bandwidth delay product), especially if you are also using window scaling or have configured a large send window. If you enable this option, you should also be sure to set net.inet.tcp.inflight_debug to 0 (disable debugging), and for production use setting net.inet.tcp.inflight_min to at least 6144 may be beneficial. However, note that setting high minimums may effectively disable bandwidth limiting depending on the link. The limiting feature reduces the amount of data built up in intermediate route and switch packet queues as well as reduces the amount of data built up in the local host's interface queue. With fewer packets queued up, interactive connections, especially over slow modems, will also be able to operate with lower Round Trip Times. However, note that this feature only effects data transmission (uploading / server side). It has no effect on data reception (downloading). Adjusting net.inet.tcp.inflight_stab is not recommended. This parameter defaults to 20, representing 2 maximal packets added to the bandwidth delay product window calculation. The additional window is required to stabilize the algorithm and improve responsiveness to changing conditions, but it can also result in higher ping times over slow links (though still much lower than you would get without the inflight algorithm). In such cases, you may wish to try reducing this parameter to 15, 10, or 5; and may also have to reduce net.inet.tcp.inflight_min (for example, to 3500) to get the desired effect. Reducing these parameters should be done as a last resort only. Adding Swap Space No matter how well you plan, sometimes a system does not run as you expect. If you find you need more swap space, it is simple enough to add. You have three ways to increase swap space: adding a new hard drive, enabling swap over NFS, and creating a swap file on an existing partition. Swap on a New Hard Drive The best way to add swap, of course, is to use this as an excuse to add another hard drive. You can always use another hard drive, after all. If you can do this, go reread the discussion of swap space in of the Handbook for some suggestions on how to best arrange your swap. Swapping over NFS Swapping over NFS is only recommended if you do not have a local hard disk to swap to. Swapping over NFS is slow and inefficient in versions of &os; prior to 4.X. It is reasonably fast and efficient in 4.0-RELEASE and newer. Even with newer versions of &os;, NFS swapping will be limited by the available network bandwidth and puts an additional burden on the NFS server. Swapfiles You can create a file of a specified size to use as a swap file. In our example here we will use a 64MB file called /usr/swap0. You can use any name you want, of course. Creating a Swapfile on &os; 4.X Be certain that your kernel configuration includes the vnode driver. It is not in recent versions of GENERIC. pseudo-device vn 1 #Vnode driver (turns a file into a device) Create a vn-device: &prompt.root; cd /dev &prompt.root; sh MAKEDEV vn0 Create a swapfile (/usr/swap0): &prompt.root; dd if=/dev/zero of=/usr/swap0 bs=1024k count=64 Set proper permissions on (/usr/swap0): &prompt.root; chmod 0600 /usr/swap0 Enable the swap file in /etc/rc.conf: swapfile="/usr/swap0" # Set to name of swapfile if aux swapfile desired. Reboot the machine or to enable the swap file immediately, type: &prompt.root; vnconfig -e /dev/vn0b /usr/swap0 swap Creating a Swapfile on &os; 5.X Be certain that your kernel configuration includes the memory disk driver (&man.md.4;). It is default in GENERIC kernel. device md # Memory "disks" Create a swapfile (/usr/swap0): &prompt.root; dd if=/dev/zero of=/usr/swap0 bs=1024k count=64 Set proper permissions on (/usr/swap0): &prompt.root; chmod 0600 /usr/swap0 Enable the swap file in /etc/rc.conf: swapfile="/usr/swap0" # Set to name of swapfile if aux swapfile desired. Reboot the machine or to enable the swap file immediately, type: &prompt.root; mdconfig -a -t vnode -f /usr/swap0 -u 0 && swapon /dev/md0 Hiten Pandya Written by Tom Rhodes Power and Resource Management It is very important to utilize hardware resources in an efficient manner. Before ACPI was introduced, it was very difficult and inflexible for operating systems to manage the power usage and thermal properties of a system. The hardware was controlled by some sort of BIOS embedded interface, such as Plug and Play BIOS (PNPBIOS), or Advanced Power Management (APM) and so on. Power and Resource Management is one of the key components of a modern operating system. For example, you may want an operating system to monitor system limits (and possibly alert you) in case your system temperature increased unexpectedly. In this section of the &os; Handbook, we will provide comprehensive information about ACPI. References will be provided for further reading at the end. Please be aware that ACPI is available on &os; 5.X and above systems as a default kernel module. For &os; 4.9, ACPI can be enabled by adding the line device acpica to a kernel configuration and rebuilding. What Is ACPI? Advanced Configuration and Power Interface (ACPI) is a standard written by an alliance of vendors to provide a standard interface for hardware resources and power management (hence the name). It is a key element in Operating System-directed configuration and Power Management, i.e.: it provides more control and flexibility to the operating system (OS). Modern systems stretched the limits of the current Plug and Play interfaces (such as APM, which is used in &os; 4.X), prior to the introduction of ACPI. ACPI is the direct successor to APM (Advanced Power Management). Shortcomings of Advanced Power Management (APM) The Advanced Power Management (APM) facility controls the power usage of a system based on its activity. The APM BIOS is supplied by the (system) vendor and it is specific to the hardware platform. An APM driver in the OS mediates access to the APM Software Interface, which allows management of power levels. There are four major problems in APM. Firstly, power management is done by the (vendor-specific) BIOS, and the OS does not have any knowledge of it. One example of this, is when the user sets idle-time values for a hard drive in the APM BIOS, that when exceeded, it (BIOS) would spin down the hard drive, without the consent of the OS. Secondly, the APM logic is embedded in the BIOS, and it operates outside the scope of the OS. This means users can only fix problems in their APM BIOS by flashing a new one into the ROM; which is a very dangerous procedure with the potential to leave the system in an unrecoverable state if it fails. Thirdly, APM is a vendor-specific technology, which means that there is a lot of parity (duplication of efforts) and bugs found in one vendor's BIOS, may not be solved in others. Last but not the least, the APM BIOS did not have enough room to implement a sophisticated power policy, or one that can adapt very well to the purpose of the machine. Plug and Play BIOS (PNPBIOS) was unreliable in many situations. PNPBIOS is 16-bit technology, so the OS has to use 16-bit emulation in order to interface with PNPBIOS methods. The &os; APM driver is documented in the &man.apm.4; manual page. Configuring <acronym>ACPI</acronym> The acpi.ko driver is loaded by default at start up by the &man.loader.8; and should not be compiled into the kernel. The reasoning behind this is that modules are easier to work with, say if switching to another acpi.ko without doing a kernel rebuild. This has the advantage of making testing easier. Another reason is that starting ACPI after a system has been brought up is not too useful, and in some cases can be fatal. In doubt, just disable ACPI all together. This driver should not and can not be unloaded because the system bus uses it for various hardware interactions. ACPI can be disabled with the &man.acpiconf.8; utility. In fact most of the interaction with ACPI can be done via &man.acpiconf.8;. Basically this means, if anything about ACPI is in the &man.dmesg.8; output, then most likely it is already running. ACPI and APM cannot coexist and should be used separately. The last one to load will terminate if the driver notices the other running. In the simplest form, ACPI can be used to put the system into a sleep mode with &man.acpiconf.8;, the flag, and a 1-5 option. Most users will only need 1. Option 5 will do a soft-off which is the same action as: &prompt.root; halt -p The other options are available. Check out the &man.acpiconf.8; manual page for more information. Nate Lawson Written by Peter Schultz With contributions from Tom Rhodes Using and Debugging &os; <acronym>ACPI</acronym> ACPI is a fundamentally new way of discovering devices, managing power usage, and providing standardized access to various hardware previously managed by the BIOS. Progress is being made toward ACPI working on all systems, but bugs in some motherboards' ACPI Machine Language (AML) bytecode, incompleteness in &os;'s kernel subsystems, and bugs in the &intel; ACPI-CA interpreter continue to appear. This document is intended to help you assist the &os; ACPI maintainers in identifying the root cause of problems you observe and debugging and developing a solution. Thanks for reading this and we hope we can solve your system's problems. Submitting Debugging Information Before submitting a problem, be sure you are running the latest BIOS version and, if available, embedded controller firmware version. For those of you that want to submit a problem right away, please send the following information to freebsd-acpi@FreeBSD.org: Description of the buggy behavior, including system type and model and anything that causes the bug to appear. Also, please note as accurately as possible when the bug began occurring if it is new for you. The &man.dmesg.8; output after boot -v, including any error messages generated by you exercising the bug. The &man.dmesg.8; output from boot -v with ACPI disabled, if disabling it helps fix the problem. Output from sysctl hw.acpi. This is also a good way of figuring out what features your system offers. URL where your ACPI Source Language (ASL) can be found. Do not send the ASL directly to the list as it can be very large. Generate a copy of your ASL by running this command: &prompt.root; acpidump -t -d > name-system.asl (Substitute your login name for name and manufacturer/model for system. Example: njl-FooCo6000.asl) Most of the developers watch the &a.current; but please submit problems to &a.acpi.name; to be sure it is seen. Please be patient, all of us have full-time jobs elsewhere. If your bug is not immediately apparent, we will probably ask you to submit a PR via &man.send-pr.1;. When entering a PR, please include the same information as requested above. This will help us track the problem and resolve it. Do not send a PR without emailing &a.acpi.name; first as we use PRs as reminders of existing problems, not a reporting mechanism. It is likely that your problem has been reported by someone before. Background ACPI is present in all modern computers that conform to the ia32 (x86), ia64 (Itanium), and amd64 (AMD) architectures. The full standard has many features including CPU performance management, power planes control, thermal zones, various battery systems, embedded controllers, and bus enumeration. Most systems implement less than the full standard. For instance, a desktop system usually only implements the bus enumeration parts while a laptop might have cooling and battery management support as well. Laptops also have suspend and resume, with their own associated complexity. An ACPI-compliant system has various components. The BIOS and chipset vendors provide various fixed tables (e.g., FADT) in memory that specify things like the APIC map (used for SMP), config registers, and simple configuration values. Additionally, a table of bytecode (the Differentiated System Description Table DSDT) is provided that specifies a tree-like name space of devices and methods. The ACPI driver must parse the fixed tables, implement an interpreter for the bytecode, and modify device drivers and the kernel to accept information from the ACPI subsystem. For &os;, &intel; has provided an interpreter (ACPI-CA) that is shared with Linux and NetBSD. The path to the ACPI-CA source code is - src/sys/contrib/dev/acpica. + src/sys/contrib/dev/acpica. The glue code that allows ACPI-CA to work on &os; is in src/sys/dev/acpica/Osd. Finally, drivers that implement various ACPI devices are found in - src/sys/dev/acpica. + src/sys/dev/acpica. Common Problems For ACPI to work correctly, all the parts have to work correctly. Here are some common problems, in order of frequency of appearance, and some possible workarounds or fixes. Suspend/Resume ACPI has three suspend to RAM (STR) states, S1-S3, and one suspend to disk state (STD), called S4. S5 is soft off and is the normal state your system is in when plugged in but not powered up. S4 can actually be implemented two separate ways. S4BIOS is a BIOS-assisted suspend to disk. S4OS is implemented entirely by the operating system. Start by checking sysctl hw.acpi for the suspend-related items. Here are the results for a Thinkpad: hw.acpi.supported_sleep_state: S3 S4 S5 hw.acpi.s4bios: 0 This means that we can use acpiconf -s to test S3, S4OS, and S5. If was one (1), we would have S4BIOS support instead of S4 OS. When testing suspend/resume, start with S1, if supported. This state is most likely to work since it does not require much driver support. No one has implemented S2 but if you have it, it is similar to S1. The next thing to try is S3. This is the deepest STR state and requires a lot of driver support to properly reinitialize your hardware. If you have problems resuming, feel free to email the &a.acpi.name; list but do not expect the problem to be resolved since there are a lot of drivers/hardware that need more testing and work. To help isolate the problem, remove as many drivers from your kernel as possible. If it works, you can narrow down which driver is the problem by loading drivers until it fails again. Typically binary drivers like nvidia.ko, X11 display drivers, and USB will have the most problems while Ethernet interfaces usually work fine. If you can properly load/unload the drivers, you can automate this by putting the appropriate commands in /etc/rc.suspend and /etc/rc.resume. There is a commented-out example for unloading and loading a driver. Try setting to zero (0) if your display is messed up after resume. Try setting longer or shorter values for to see if that helps. Another thing to try is load a recent Linux distribution with ACPI support and test their suspend/resume support on the same hardware. If it works on Linux, it is likely a &os; driver problem and narrowing down which driver causes the problems will help us fix the problem. Note that the ACPI maintainers do not usually maintain other drivers (e.g sound, ATA, etc.) so any work done on tracking down a driver problem should probably eventually be posted to the &a.current.name; list and mailed to the driver maintainer. If you are feeling adventurous, go ahead and start putting some debugging &man.printf.3;s in a problematic driver to track down where in its resume function it hangs. Finally, try disabling ACPI and enabling APM instead. If suspend/resume works with APM, you may be better off sticking with APM, especially on older hardware (pre-2000). It took vendors a while to get ACPI support correct and older hardware is more likely to have BIOS problems with ACPI. System Hangs (temporary or permanent) Most system hangs are a result of lost interrupts or an interrupt storm. Chipsets have a lot of problems based on how the BIOS configures interrupts before boot, correctness of the APIC (MADT) table, and routing of the System Control Interrupt (SCI). Interrupt storms can be distinguished from lost interrupts by checking the output of vmstat -i and looking at the line that has acpi0. If the counter is increasing at more than a couple per second, you have an interrupt storm. If the system appears hung, try breaking to DDB (CTRL ALTESC on console) and type show interrupts. Your best hope when dealing with interrupt problems is to try disabling APIC support with hint.apic.0.disabled="1" in loader.conf. Panics Panics are relatively rare for ACPI and are the top priority to be fixed. The first step is to isolate the steps to reproduce the panic (if possible) and get a backtrace. Follow the advice for enabling options DDB and setting up a serial console (see ) or setting up a &man.dump.8; partition. You can get a backtrace in DDB with tr. If you have to handwrite the backtrace, be sure to at least get the lowest five (5) and top five (5) lines in the trace. Then, try to isolate the problem by booting with ACPI disabled. If that works, you can isolate the ACPI subsystem by using various values of . See the &man.acpi.4; manual page for some examples. System Powers Up After Suspend or Shutdown First, try setting hw.acpi.disable_on_poweroff="0" in &man.loader.conf.5;. This keeps ACPI from disabling various events during the shutdown process. Some systems need this value set to 1 (the default) for the same reason. This usually fixes the problem of a system powering up spontaneously after a suspend or poweroff. Other Problems If you have other problems with ACPI (working with a docking station, devices not detected, etc.), please email a description to the mailing list as well; however, some of these issues may be related to unfinished parts of the ACPI subsystem so they might take a while to be implemented. Please be patient and prepared to test patches we may send you. <acronym>ASL</acronym>, <command>acpidump</command>, and <acronym>IASL</acronym> The most common problem is the BIOS vendors providing incorrect (or outright buggy!) bytecode. This is usually manifested by kernel console messages like this: ACPI-1287: *** Error: Method execution failed [\\_SB_.PCI0.LPC0.FIGD._STA] \\ (Node 0xc3f6d160), AE_NOT_FOUND Often, you can resolve these problems by updating your BIOS to the latest revision. Most console messages are harmless but if you have other problems like battery status not working, they're a good place to start looking for problems in the AML. The bytecode, known as AML, is compiled from a source language called ASL. The AML is found in the table known as the DSDT. To get a copy of your ASL, use &man.acpidump.8;. You should use both the (show contents of the fixed tables) and (disassemble AML to ASL) options. See the Submitting Debugging Information section for an example syntax. The simplest first check you can do is to recompile your ASL to check for errors. Warnings can usually be ignored but errors are bugs that will usually prevent ACPI from working correctly. To recompile your ASL, issue the following command: &prompt.root; iasl your.asl Fixing Your <acronym>ASL</acronym> In the long run, our goal is for almost everyone to have ACPI work without any user intervention. At this point, however, we are still developing workarounds for common mistakes made by the BIOS vendors. The µsoft; interpreter (acpi.sys and acpiec.sys) does not strictly check for adherence to the standard, and thus many BIOS vendors who only test ACPI under &windows; never fix their ASL. We hope to continue to identify and document exactly what non-standard behavior is allowed by µsoft;'s interpreter and replicate it so &os; can work without forcing users to fix the ASL. As a workaround and to help us identify behavior, you can fix the ASL manually. If this works for you, please send a &man.diff.1; of the old and new ASL so we can possibly work around the buggy behavior in ACPI-CA and thus make your fix unnecessary. Here is a list of common error messages, their cause, and how to fix them: _OS dependencies Some AML assumes the world consists of various &windows; versions. You can tell &os; to claim it is any OS to see if this fixes problems you may have. An easy way to override this is to set hw.acpi.osname="Windows 2001" in /boot/loader.conf or other similar strings you find in the ASL. Missing Return statements Some methods do not explicitly return a value as the standard requires. While ACPI-CA does not handle this, &os; has a workaround that allows it to return the value implicitly. You can also add explicit Return statements where required if you know what value should be returned. To force iasl to compile the ASL, use the flag. Overriding the Default <acronym>AML</acronym> After you customize your.asl, you will want to compile it, run: &prompt.root; iasl your.asl You can add the flag to force creation of the AML, even if there are errors during compilation. Remember that some errors (e.g., missing Return statements) are automatically worked around by the interpreter. DSDT.aml is the default output filename for iasl. You can load this instead of your BIOS's buggy copy (which is still present in flash memory) by editing /boot/loader.conf as follows: acpi_dsdt_load="YES" acpi_dsdt_name="/boot/DSDT.aml" Be sure to copy your DSDT.aml to the - /boot directory. + /boot directory. Getting Debugging Output From <acronym>ACPI</acronym> The ACPI driver has a very flexible debugging facility. It allows you to specify a set of subsystems as well as the level of verbosity. The subsystems you wish to debug are specified as layers and are broken down into ACPI-CA components (ACPI_ALL_COMPONENTS) and ACPI hardware support (ACPI_ALL_DRIVERS). The verbosity of debugging output is specified as the level and ranges from ACPI_LV_ERROR (just report errors) to ACPI_LV_VERBOSE (everything). The level is a bitmask so multiple options can be set at once, separated by spaces. In practice, you will want to use a serial console to log the output if it is so long it flushes the console message buffer. A full list of the individual layers and levels is found in the &man.acpi.4; manual page. Debugging output is not enabled by default. To enable it, add options ACPI_DEBUG to your kernel configuration file if ACPI is compiled into the kernel. You can add ACPI_DEBUG=1 to your /etc/make.conf to enable it globally. If it is a module, you can recompile just your acpi.ko module as follows: &prompt.root; cd /sys/modules/acpi/acpi && make clean && make ACPI_DEBUG=1 Install acpi.ko in - /boot/kernel and add your + /boot/kernel and add your desired level and layer to loader.conf. This example enables debug messages for all ACPI-CA components and all ACPI hardware drivers (CPU, LID, etc.) It will only output error messages, the least verbose level. debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS" debug.acpi.level="ACPI_LV_ERROR" If the information you want is triggered by a specific event (say, a suspend and then resume), you can leave out changes to loader.conf and instead use sysctl to specify the layer and level after booting and preparing your system for the specific event. The sysctls are named the same as the tunables in loader.conf. References More information about ACPI may be found in the following locations: The &a.acpi; The ACPI Mailing List Archives The old ACPI Mailing List Archives The ACPI 2.0 Specification &os; Manual pages: &man.acpi.4;, &man.acpi.thermal.4;, &man.acpidump.8;, &man.iasl.8;, &man.acpidb.8; DSDT debugging resource. (Uses Compaq as an example but generally useful.) diff --git a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml index 61e1fd3c39..b7dbfc9155 100644 --- a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml @@ -1,3808 +1,3808 @@ Storage Synopsis This chapter covers the use of disks in FreeBSD. This includes memory-backed disks, network-attached disks, standard SCSI/IDE storage devices, and devices using the USB interface. After reading this chapter, you will know: The terminology FreeBSD uses to describe the organization of data on a physical disk (partitions and slices). How to add additional hard disks to your system. How to configure &os; to use USB storage devices. How to set up virtual file systems, such as memory disks. How to use quotas to limit disk space usage. How to encrypt disks to secure them against attackers. How to create and burn CDs and DVDs on FreeBSD. The various storage media options for backups. How to use backup programs available under FreeBSD. How to backup to floppy disks. What snapshots are and how to use them efficiently. Before reading this chapter, you should: Know how to configure and install a new FreeBSD kernel (). Device Names The following is a list of physical storage devices supported in FreeBSD, and the device names associated with them. Physical Disk Naming Conventions Drive type Drive device name IDE hard drives ad IDE CDROM drives acd SCSI hard drives and USB Mass storage devices da SCSI CDROM drives cd Assorted non-standard CDROM drives mcd for Mitsumi CD-ROM, scd for Sony CD-ROM, matcd for Matsushita/Panasonic CD-ROM The &man.matcd.4; driver has been removed in FreeBSD 4.X branch since October 5th, 2002 and does not exist in FreeBSD 5.0 and 5.1 releases. However this driver is back in the FreeBSD 5.X branch since June 16th, 2003. Floppy drives fd SCSI tape drives sa IDE tape drives ast Flash drives fla for &diskonchip; Flash device RAID drives aacd for &adaptec; AdvancedRAID, mlxd and mlyd for &mylex;, amrd for AMI &megaraid;, idad for Compaq Smart RAID, twed for &tm.3ware; RAID.
David O'Brien Originally contributed by Adding Disks disks adding Lets say we want to add a new SCSI disk to a machine that currently only has a single drive. First turn off the computer and install the drive in the computer following the instructions of the computer, controller, and drive manufacturer. Due to the wide variations of procedures to do this, the details are beyond the scope of this document. Login as user root. After you have installed the drive, inspect /var/run/dmesg.boot to ensure the new disk was found. Continuing with our example, the newly added drive will be da1 and we want to mount it on /1 (if you are adding an IDE drive, the device name will be wd1 in pre-4.0 systems, or ad1 in 4.X and 5.X systems). partitions slices fdisk Because FreeBSD runs on IBM-PC compatible computers, it must take into account the PC BIOS partitions. These are different from the traditional BSD partitions. A PC disk has up to four BIOS partition entries. If the disk is going to be truly dedicated to FreeBSD, you can use the dedicated mode. Otherwise, FreeBSD will have to live within one of the PC BIOS partitions. FreeBSD calls the PC BIOS partitions slices so as not to confuse them with traditional BSD partitions. You may also use slices on a disk that is dedicated to FreeBSD, but used in a computer that also has another operating system installed. This is to not confuse the fdisk utility of the other operating system. In the slice case the drive will be added as /dev/da1s1e. This is read as: SCSI disk, unit number 1 (second SCSI disk), slice 1 (PC BIOS partition 1), and e BSD partition. In the dedicated case, the drive will be added simply as /dev/da1e. Due to the use of 32-bit integers to store the number of sectors &man.bsdlabel.8; (called &man.disklabel.8; in &os; 4.X) is limited to 2^32-1 sectors per disk or 2TB in most cases. The &man.fdisk.8; format allows a starting sector of no more than 2^32-1 and a length of no more than 2^32-1, limiting partitions to 2TB and disks to 4TB in most cases. The &man.sunlabel.8; format is limited to 2^32-1 sectors per partition and 8 partitions for a total of 16TB. For larger disks, &man.gpt.8; partitions may be used. Using &man.sysinstall.8; sysinstall adding disks su Navigating <application>Sysinstall</application> You may use /stand/sysinstall to partition and label a new disk using its easy to use menus. Either login as user root or use the su command. Run /stand/sysinstall and enter the Configure menu. Within the FreeBSD Configuration Menu, scroll down and select the Fdisk option. <application>fdisk</application> Partition Editor Once inside fdisk, we can type A to use the entire disk for FreeBSD. When asked if you want to remain cooperative with any future possible operating systems, answer YES. Write the changes to the disk using W. Now exit the FDISK editor by typing q. Next you will be asked about the Master Boot Record. Since you are adding a disk to an already running system, choose None. Disk Label Editor BSD partitions Next, you need to exit sysinstall and start it again. Follow the directions above, although this time choose the Label option. This will enter the Disk Label Editor. This is where you will create the traditional BSD partitions. A disk can have up to eight partitions, labeled a-h. A few of the partition labels have special uses. The a partition is used for the root partition (/). Thus only your system disk (e.g, the disk you boot from) should have an a partition. The b partition is used for swap partitions, and you may have many disks with swap partitions. The c partition addresses the entire disk in dedicated mode, or the entire FreeBSD slice in slice mode. The other partitions are for general use. sysinstall's Label editor favors the e partition for non-root, non-swap partitions. Within the Label editor, create a single file system by typing C. When prompted if this will be a FS (file system) or swap, choose FS and type in a mount point (e.g, /mnt). When adding a disk in post-install mode, sysinstall will not create entries in /etc/fstab for you, so the mount point you specify is not important. You are now ready to write the new label to the disk and create a file system on it. Do this by typing W. Ignore any errors from sysinstall that it could not mount the new partition. Exit the Label Editor and sysinstall completely. Finish The last step is to edit /etc/fstab to add an entry for your new disk. Using Command Line Utilities Using Slices This setup will allow your disk to work correctly with other operating systems that might be installed on your computer and will not confuse other operating systems' fdisk utilities. It is recommended to use this method for new disk installs. Only use dedicated mode if you have a good reason to do so! &prompt.root; dd if=/dev/zero of=/dev/da1 bs=1k count=1 &prompt.root; fdisk -BI da1 #Initialize your new disk &prompt.root; disklabel -B -w -r da1s1 auto #Label it. &prompt.root; disklabel -e da1s1 # Edit the disklabel just created and add any partitions. &prompt.root; mkdir -p /1 &prompt.root; newfs /dev/da1s1e # Repeat this for every partition you created. &prompt.root; mount /dev/da1s1e /1 # Mount the partition(s) &prompt.root; vi /etc/fstab # Add the appropriate entry/entries to your /etc/fstab. If you have an IDE disk, substitute ad for da. On pre-4.X systems use wd. Dedicated OS/2 If you will not be sharing the new drive with another operating system, you may use the dedicated mode. Remember this mode can confuse Microsoft operating systems; however, no damage will be done by them. IBM's &os2; however, will appropriate any partition it finds which it does not understand. &prompt.root; dd if=/dev/zero of=/dev/da1 bs=1k count=1 &prompt.root; disklabel -Brw da1 auto &prompt.root; disklabel -e da1 # create the `e' partition &prompt.root; newfs -d0 /dev/da1e &prompt.root; mkdir -p /1 &prompt.root; vi /etc/fstab # add an entry for /dev/da1e &prompt.root; mount /1 An alternate method is: &prompt.root; dd if=/dev/zero of=/dev/da1 count=2 &prompt.root; disklabel /dev/da1 | disklabel -BrR da1 /dev/stdin &prompt.root; newfs /dev/da1e &prompt.root; mkdir -p /1 &prompt.root; vi /etc/fstab # add an entry for /dev/da1e &prompt.root; mount /1 Since &os; 5.1-RELEASE, the &man.bsdlabel.8; utility replaces the old &man.disklabel.8; program. With &man.bsdlabel.8; a number of obsolete options and parameters have been retired; in the examples above the option should be removed with &man.bsdlabel.8;. For more information, please refer to the &man.bsdlabel.8; manual page. RAID Software RAID Christopher Shumway Original work by Jim Brown Revised by RAIDsoftware RAIDCCD Concatenated Disk Driver (CCD) Configuration When choosing a mass storage solution the most important factors to consider are speed, reliability, and cost. It is rare to have all three in balance; normally a fast, reliable mass storage device is expensive, and to cut back on cost either speed or reliability must be sacrificed. In designing the system described below, cost was chosen as the most important factor, followed by speed, then reliability. Data transfer speed for this system is ultimately constrained by the network. And while reliability is very important, the CCD drive described below serves online data that is already fully backed up on CD-R's and can easily be replaced. Defining your own requirements is the first step in choosing a mass storage solution. If your requirements prefer speed or reliability over cost, your solution will differ from the system described in this section. Installing the Hardware In addition to the IDE system disk, three Western Digital 30GB, 5400 RPM IDE disks form the core of the CCD disk described below providing approximately 90GB of online storage. Ideally, each IDE disk would have its own IDE controller and cable, but to minimize cost, additional IDE controllers were not used. Instead the disks were configured with jumpers so that each IDE controller has one master, and one slave. Upon reboot, the system BIOS was configured to automatically detect the disks attached. More importantly, FreeBSD detected them on reboot: ad0: 19574MB <WDC WD205BA> [39770/16/63] at ata0-master UDMA33 ad1: 29333MB <WDC WD307AA> [59598/16/63] at ata0-slave UDMA33 ad2: 29333MB <WDC WD307AA> [59598/16/63] at ata1-master UDMA33 ad3: 29333MB <WDC WD307AA> [59598/16/63] at ata1-slave UDMA33 If FreeBSD does not detect all the disks, ensure that you have jumpered them correctly. Most IDE drives also have a Cable Select jumper. This is not the jumper for the master/slave relationship. Consult the drive documentation for help in identifying the correct jumper. Next, consider how to attach them as part of the file system. You should research both &man.vinum.8; () and &man.ccd.4;. In this particular configuration, &man.ccd.4; was chosen. Setting Up the CCD The driver &man.ccd.4; allows you to take several identical disks and concatenate them into one logical file system. In order to use &man.ccd.4;, you need a kernel with &man.ccd.4; support built in. Add this line to your kernel configuration file, rebuild, and reinstall the kernel: pseudo-device ccd 4 On 5.X systems, you have to use instead the following line: device ccd In FreeBSD 5.X, it is not necessary to specify a number of &man.ccd.4; devices, as the &man.ccd.4; device driver is now self-cloning — new device instances will automatically be created on demand. The &man.ccd.4; support can also be loaded as a kernel loadable module in FreeBSD 3.0 or later. To set up &man.ccd.4;, you must first use &man.disklabel.8; to label the disks: disklabel -r -w ad1 auto disklabel -r -w ad2 auto disklabel -r -w ad3 auto This creates a disklabel for ad1c, ad2c and ad3c that spans the entire disk. Since &os; 5.1-RELEASE, the &man.bsdlabel.8; utility replaces the old &man.disklabel.8; program. With &man.bsdlabel.8; a number of obsolete options and parameters have been retired; in the examples above the option should be removed. For more information, please refer to the &man.bsdlabel.8; manual page. The next step is to change the disk label type. You can use &man.disklabel.8; to edit the disks: disklabel -e ad1 disklabel -e ad2 disklabel -e ad3 This opens up the current disk label on each disk with the editor specified by the EDITOR environment variable, typically &man.vi.1;. An unmodified disk label will look something like this: 8 partitions: # size offset fstype [fsize bsize bps/cpg] c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597) Add a new e partition for &man.ccd.4; to use. This can usually be copied from the c partition, but the must be 4.2BSD. The disk label should now look something like this: 8 partitions: # size offset fstype [fsize bsize bps/cpg] c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597) e: 60074784 0 4.2BSD 0 0 0 # (Cyl. 0 - 59597) Building the File System The device node for ccd0c may not exist yet, so to create it, perform the following commands: cd /dev sh MAKEDEV ccd0 In FreeBSD 5.0, &man.devfs.5; will automatically manage device nodes in /dev, so use of MAKEDEV is not necessary. Now that you have all of the disks labeled, you must build the &man.ccd.4;. To do that, use &man.ccdconfig.8;, with options similar to the following: ccdconfig ccd0 32 0 /dev/ad1e /dev/ad2e /dev/ad3e The use and meaning of each option is shown below: The first argument is the device to configure, in this case, /dev/ccd0c. The /dev/ portion is optional. The interleave for the file system. The interleave defines the size of a stripe in disk blocks, each normally 512 bytes. So, an interleave of 32 would be 16,384 bytes. Flags for &man.ccdconfig.8;. If you want to enable drive mirroring, you can specify a flag here. This configuration does not provide mirroring for &man.ccd.4;, so it is set at 0 (zero). The final arguments to &man.ccdconfig.8; are the devices to place into the array. Use the complete pathname for each device. After running &man.ccdconfig.8; the &man.ccd.4; is configured. A file system can be installed. Refer to &man.newfs.8; for options, or simply run: newfs /dev/ccd0c Making it All Automatic Generally, you will want to mount the &man.ccd.4; upon each reboot. To do this, you must configure it first. Write out your current configuration to /etc/ccd.conf using the following command: ccdconfig -g > /etc/ccd.conf During reboot, the script /etc/rc runs ccdconfig -C if /etc/ccd.conf exists. This automatically configures the &man.ccd.4; so it can be mounted. If you are booting into single user mode, before you can &man.mount.8; the &man.ccd.4;, you need to issue the following command to configure the array: ccdconfig -C To automatically mount the &man.ccd.4;, place an entry for the &man.ccd.4; in /etc/fstab so it will be mounted at boot time: /dev/ccd0c /media ufs rw 2 2 The Vinum Volume Manager RAIDsoftware RAID Vinum The Vinum Volume Manager is a block device driver which implements virtual disk drives. It isolates disk hardware from the block device interface and maps data in ways which result in an increase in flexibility, performance and reliability compared to the traditional slice view of disk storage. &man.vinum.8; implements the RAID-0, RAID-1 and RAID-5 models, both individually and in combination. See for more information about &man.vinum.8;. Hardware RAID RAID hardware FreeBSD also supports a variety of hardware RAID controllers. These devices control a RAID subsystem without the need for FreeBSD specific software to manage the array. Using an on-card BIOS, the card controls most of the disk operations itself. The following is a brief setup description using a Promise IDE RAID controller. When this card is installed and the system is started up, it displays a prompt requesting information. Follow the instructions to enter the card's setup screen. From here, you have the ability to combine all the attached drives. After doing so, the disk(s) will look like a single drive to FreeBSD. Other RAID levels can be set up accordingly. Rebuilding ATA RAID1 Arrays FreeBSD allows you to hot-replace a failed disk in an array. This requires that you catch it before you reboot. You will probably see something like the following in /var/log/messages or in the &man.dmesg.8; output: ad6 on monster1 suffered a hard error. ad6: READ command timeout tag=0 serv=0 - resetting ad6: trying fallback to PIO mode ata3: resetting devices .. done ad6: hard error reading fsbn 1116119 of 0-7 (ad6 bn 1116119; cn 1107 tn 4 sn 11)\\ status=59 error=40 ar0: WARNING - mirror lost Using &man.atacontrol.8;, check for further information: &prompt.root; atacontrol list ATA channel 0: Master: no device present Slave: acd0 <HL-DT-ST CD-ROM GCR-8520B/1.00> ATA/ATAPI rev 0 ATA channel 1: Master: no device present Slave: no device present ATA channel 2: Master: ad4 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present ATA channel 3: Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present &prompt.root; atacontrol status ar0 ar0: ATA RAID1 subdisks: ad4 ad6 status: DEGRADED You will first need to detach the disk from the array so that you can safely remove it: &prompt.root; atacontrol detach 3 Replace the disk. Reattach the disk as a spare: &prompt.root; atacontrol attach 3 Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present Rebuild the array: &prompt.root; atacontrol rebuild ar0 The rebuild command hangs until complete. However, it is possible to open another terminal (using Alt Fn) and check on the progress by issuing the following command: &prompt.root; dmesg | tail -10 [output removed] ad6: removed from configuration ad6: deleted from ar0 disk1 ad6: inserted into ar0 disk1 as spare &prompt.root; atacontrol status ar0 ar0: ATA RAID1 subdisks: ad4 ad6 status: REBUILDING 0% completed Wait until this operation completes. Marc Fonvieille Contributed by USB Storage Devices USB disks A lot of external storage solutions, nowadays, use the Universal Serial Bus (USB): hard drives, USB thumbdrives, CD-R burners, etc. &os; provides support for these devices. Configuration The USB mass storage devices driver, &man.umass.4;, provides the support for USB storage devices. If you use the GENERIC kernel, you do not have to change anything in your configuration. If you use a custom kernel, be sure that the following lines are present in your kernel configuration file: device scbus device da device pass device uhci device ohci device usb device umass The &man.umass.4; driver uses the SCSI subsystem to access to the USB storage devices, your USB device will be seen as a SCSI device by the system. Depending on the USB chipset on your motherboard, you only need either device uhci or device ohci, however having both in the kernel configuration file is harmless. Do not forget to compile and install the new kernel if you added any lines. If your USB device is a CD-R or DVD burner, the SCSI CD-ROM driver, &man.cd.4;, must be added to the kernel via the line: device cd Since the burner is seen as a SCSI drive, the driver &man.atapicam.4; should not be used in the kernel configuration. Support for USB 2.0 controllers is provided on &os; 5.X, and on the 4.X branch since &os; 4.10-RELEASE. You have to add: device ehci to your configuration file for USB 2.0 support. Note &man.uhci.4; and &man.ohci.4; drivers are still needed if you want USB 1.X support. On &os; 4.X, the USB daemon (&man.usbd.8;) must be running to be able to see some USB devices. To enable it, add usbd_enable="YES" to your /etc/rc.conf file and reboot the machine. Testing the Configuration The configuration is ready to be tested: plug in your USB device, and in the system message buffer (&man.dmesg.8;), the drive should appear as something like: umass0: USB Solid state disk, rev 1.10/1.00, addr 2 GEOM: create disk da0 dp=0xc2d74850 da0 at umass-sim0 bus 0 target 0 lun 0 da0: <Generic Traveling Disk 1.11> Removable Direct Access SCSI-2 device da0: 1.000MB/s transfers da0: 126MB (258048 512 byte sectors: 64H 32S/T 126C) Of course, the brand, the device node (da0) and other details can differ according to your configuration. Since the USB device is seen as a SCSI one, the camcontrol command can be used to list the USB storage devices attached to the system: &prompt.root; camcontrol devlist <Generic Traveling Disk 1.11> at scbus0 target 0 lun 0 (da0,pass0) If the drive comes with a file system, you should be able to mount it. The will help you to format and create partitions on the USB drive if needed. If you unplug the device (the disk must be unmounted before), you should see, in the system message buffer, something like the following: umass0: at uhub0 port 1 (addr 2) disconnected (da0:umass-sim0:0:0:0): lost device (da0:umass-sim0:0:0:0): removing device entry GEOM: destroy disk da0 dp=0xc2d74850 umass0: detached Further Reading Beside the Adding Disks and Mounting and Unmounting File Systems sections, reading various manual pages may be also useful: &man.umass.4;, &man.camcontrol.8;, and &man.usbdevs.8;. Mike Meyer Contributed by Creating and Using Optical Media (CDs) CDROMs creating Introduction CDs have a number of features that differentiate them from conventional disks. Initially, they were not writable by the user. They are designed so that they can be read continuously without delays to move the head between tracks. They are also much easier to transport between systems than similarly sized media were at the time. CDs do have tracks, but this refers to a section of data to be read continuously and not a physical property of the disk. To produce a CD on FreeBSD, you prepare the data files that are going to make up the tracks on the CD, then write the tracks to the CD. ISO 9660 file systems ISO 9660 The ISO 9660 file system was designed to deal with these differences. It unfortunately codifies file system limits that were common then. Fortunately, it provides an extension mechanism that allows properly written CDs to exceed those limits while still working with systems that do not support those extensions. sysutils/cdrtools The sysutils/cdrtools port includes &man.mkisofs.8;, a program that you can use to produce a data file containing an ISO 9660 file system. It has options that support various extensions, and is described below. CD burner ATAPI Which tool to use to burn the CD depends on whether your CD burner is ATAPI or something else. ATAPI CD burners use the burncd program that is part of the base system. SCSI and USB CD burners should use cdrecord from the sysutils/cdrtools port. burncd has a limited number of supported drives. To find out if a drive is supported, see the CD-R/RW supported drives list. CD burner ATAPI/CAM driver If you run &os; 5.X, &os; 4.8-RELEASE version or higher, it will be possible to use cdrecord and other tools for SCSI drives on an ATAPI hardware with the ATAPI/CAM module. If you want a CD burning software with a graphical user interface, you should have a look to X-CD-Roast or K3b. These tools are available as packages or from the sysutils/xcdroast and sysutils/k3b ports. X-CD-Roast and K3b require the ATAPI/CAM module with ATAPI hardware. mkisofs The &man.mkisofs.8; program, which is part of the sysutils/cdrtools port, produces an ISO 9660 file system that is an image of a directory tree in the &unix; file system name space. The simplest usage is: &prompt.root; mkisofs -o imagefile.iso /path/to/tree file systems ISO 9660 This command will create an imagefile.iso containing an ISO 9660 file system that is a copy of the tree at /path/to/tree. In the process, it will map the file names to names that fit the limitations of the standard ISO 9660 file system, and will exclude files that have names uncharacteristic of ISO file systems. file systems HFS file systems Joliet A number of options are available to overcome those restrictions. In particular, enables the Rock Ridge extensions common to &unix; systems, enables Joliet extensions used by Microsoft systems, and can be used to create HFS file systems used by &macos;. For CDs that are going to be used only on FreeBSD systems, can be used to disable all filename restrictions. When used with , it produces a file system image that is identical to the FreeBSD tree you started from, though it may violate the ISO 9660 standard in a number of ways. CDROMs creating bootable The last option of general use is . This is used to specify the location of the boot image for use in producing an El Torito bootable CD. This option takes an argument which is the path to a boot image from the top of the tree being written to the CD. By default, &man.mkisofs.8; creates an ISO image in the so-called floppy disk emulation mode, and thus expects the boot image to be exactly 1200, 1440 or 2880 KB in size. Some boot loaders, like the one used by the FreeBSD distribution disks, do not use emulation mode; in this case, the option should be used. So, if /tmp/myboot holds a bootable FreeBSD system with the boot image in /tmp/myboot/boot/cdboot, you could produce the image of an ISO 9660 file system in /tmp/bootable.iso like so: &prompt.root; mkisofs -R -no-emul-boot -b boot/cdboot -o /tmp/bootable.iso /tmp/myboot Having done that, if you have vn (FreeBSD 4.X), or md (FreeBSD 5.X) configured in your kernel, you can mount the file system with: &prompt.root; vnconfig -e vn0c /tmp/bootable.iso &prompt.root; mount -t cd9660 /dev/vn0c /mnt for FreeBSD 4.X, and for FreeBSD 5.X: &prompt.root; mdconfig -a -t vnode -f /tmp/bootable.iso -u 0 &prompt.root; mount -t cd9660 /dev/md0 /mnt At which point you can verify that /mnt and /tmp/myboot are identical. There are many other options you can use with &man.mkisofs.8; to fine-tune its behavior. In particular: modifications to an ISO 9660 layout and the creation of Joliet and HFS discs. See the &man.mkisofs.8; manual page for details. burncd CDROMs burning If you have an ATAPI CD burner, you can use the burncd command to burn an ISO image onto a CD. burncd is part of the base system, installed as /usr/sbin/burncd. Usage is very simple, as it has few options: &prompt.root; burncd -f cddevice data imagefile.iso fixate Will burn a copy of imagefile.iso on cddevice. The default device is /dev/acd0 (or /dev/acd0c under &os; 4.X). See &man.burncd.8; for options to set the write speed, eject the CD after burning, and write audio data. cdrecord If you do not have an ATAPI CD burner, you will have to use cdrecord to burn your CDs. cdrecord is not part of the base system; you must install it from either the port at sysutils/cdrtools or the appropriate package. Changes to the base system can cause binary versions of this program to fail, possibly resulting in a coaster. You should therefore either upgrade the port when you upgrade your system, or if you are tracking -STABLE, upgrade the port when a new version becomes available. While cdrecord has many options, basic usage is even simpler than burncd. Burning an ISO 9660 image is done with: &prompt.root; cdrecord dev=device imagefile.iso The tricky part of using cdrecord is finding the to use. To find the proper setting, use the flag of cdrecord, which might produce results like this: CDROMs burning &prompt.root; cdrecord -scanbus Cdrecord 1.9 (i386-unknown-freebsd4.2) Copyright (C) 1995-2000 Jörg Schilling Using libscg version 'schily-0.1' scsibus0: 0,0,0 0) 'SEAGATE ' 'ST39236LW ' '0004' Disk 0,1,0 1) 'SEAGATE ' 'ST39173W ' '5958' Disk 0,2,0 2) * 0,3,0 3) 'iomega ' 'jaz 1GB ' 'J.86' Removable Disk 0,4,0 4) 'NEC ' 'CD-ROM DRIVE:466' '1.26' Removable CD-ROM 0,5,0 5) * 0,6,0 6) * 0,7,0 7) * scsibus1: 1,0,0 100) * 1,1,0 101) * 1,2,0 102) * 1,3,0 103) * 1,4,0 104) * 1,5,0 105) 'YAMAHA ' 'CRW4260 ' '1.0q' Removable CD-ROM 1,6,0 106) 'ARTEC ' 'AM12S ' '1.06' Scanner 1,7,0 107) * This lists the appropriate value for the devices on the list. Locate your CD burner, and use the three numbers separated by commas as the value for . In this case, the CRW device is 1,5,0, so the appropriate input would be . There are easier ways to specify this value; see &man.cdrecord.1; for details. That is also the place to look for information on writing audio tracks, controlling the speed, and other things. Duplicating Audio CDs You can duplicate an audio CD by extracting the audio data from the CD to a series of files, and then writing these files to a blank CD. The process is slightly different for ATAPI and SCSI drives. SCSI Drives Use cdda2wav to extract the audio. &prompt.user; cdda2wav -v255 -D2,0 -B -Owav Use cdrecord to write the .wav files. &prompt.user; cdrecord -v dev=2,0 -dao -useinfo *.wav Make sure that 2,0 is set appropriately, as described in . ATAPI Drives The ATAPI CD driver makes each track available as /dev/acddtnn, where d is the drive number, and nn is the track number written with two decimal digits, prefixed with zero as needed. So the first track on the first disk is /dev/acd0t01, the second is /dev/acd0t02, the third is /dev/acd0t03, and so on. Make sure the appropriate files exist in /dev. &prompt.root; cd /dev &prompt.root; sh MAKEDEV acd0t99 In FreeBSD 5.0, &man.devfs.5; will automatically create and manage entries in /dev for you, so it is not necessary to use MAKEDEV. Extract each track using &man.dd.1;. You must also use a specific block size when extracting the files. &prompt.root; dd if=/dev/acd0t01 of=track1.cdr bs=2352 &prompt.root; dd if=/dev/acd0t02 of=track2.cdr bs=2352 ... Burn the extracted files to disk using burncd. You must specify that these are audio files, and that burncd should fixate the disk when finished. &prompt.root; burncd -f /dev/acd0 audio track1.cdr track2.cdr ... fixate Duplicating Data CDs You can copy a data CD to a image file that is functionally equivalent to the image file created with &man.mkisofs.8;, and you can use it to duplicate any data CD. The example given here assumes that your CDROM device is acd0. Substitute your correct CDROM device. Under &os; 4.X, a c must be appended to the end of the device name to indicate the entire partition or, in the case of CDROMs, the entire disc. &prompt.root; dd if=/dev/acd0 of=file.iso bs=2048 Now that you have an image, you can burn it to CD as described above. Using Data CDs Now that you have created a standard data CDROM, you probably want to mount it and read the data on it. By default, &man.mount.8; assumes that a file system is of type ufs. If you try something like: &prompt.root; mount /dev/cd0 /mnt you will get a complaint about Incorrect super block, and no mount. The CDROM is not a UFS file system, so attempts to mount it as such will fail. You just need to tell &man.mount.8; that the file system is of type ISO9660, and everything will work. You do this by specifying the option &man.mount.8;. For example, if you want to mount the CDROM device, /dev/cd0, under /mnt, you would execute: &prompt.root; mount -t cd9660 /dev/cd0 /mnt Note that your device name (/dev/cd0 in this example) could be different, depending on the interface your CDROM uses. Also, the option just executes &man.mount.cd9660.8;. The above example could be shortened to: &prompt.root; mount_cd9660 /dev/cd0 /mnt You can generally use data CDROMs from any vendor in this way. Disks with certain ISO 9660 extensions might behave oddly, however. For example, Joliet disks store all filenames in two-byte Unicode characters. The FreeBSD kernel does not speak Unicode (yet!), so non-English characters show up as question marks. (If you are running FreeBSD 4.3 or later, the CD9660 driver includes hooks to load an appropriate Unicode conversion table on the fly. Modules for some of the common encodings are available via the sysutils/cd9660_unicode port.) Occasionally, you might get Device not configured when trying to mount a CDROM. This usually means that the CDROM drive thinks that there is no disk in the tray, or that the drive is not visible on the bus. It can take a couple of seconds for a CDROM drive to realize that it has been fed, so be patient. Sometimes, a SCSI CDROM may be missed because it did not have enough time to answer the bus reset. If you have a SCSI CDROM please add the following option to your kernel configuration and rebuild your kernel. options SCSI_DELAY=15000 This tells your SCSI bus to pause 15 seconds during boot, to give your CDROM drive every possible chance to answer the bus reset. Burning Raw Data CDs You can choose to burn a file directly to CD, without creating an ISO 9660 file system. Some people do this for backup purposes. This runs more quickly than burning a standard CD: &prompt.root; burncd -f /dev/acd1 -s 12 data archive.tar.gz fixate In order to retrieve the data burned to such a CD, you must read data from the raw device node: &prompt.root; tar xzvf /dev/acd1 You cannot mount this disk as you would a normal CDROM. Such a CDROM cannot be read under any operating system except FreeBSD. If you want to be able to mount the CD, or share data with another operating system, you must use &man.mkisofs.8; as described above. Marc Fonvieille Contributed by CD burner ATAPI/CAM driver Using the ATAPI/CAM Driver This driver allows ATAPI devices (CD-ROM, CD-RW, DVD drives etc...) to be accessed through the SCSI subsystem, and so allows the use of applications like sysutils/cdrdao or &man.cdrecord.1;. To use this driver, you will need to add the following lines to your kernel configuration file: device atapicam device scbus device cd device pass You also need the following line in your kernel configuration file: device ata which should already be present. Then rebuild, install your new kernel, and reboot your machine. During the boot process, your burner should show up, like so: acd0: CD-RW <MATSHITA CD-RW/DVD-ROM UJDA740> at ata1-master PIO4 cd0 at ata1 bus 0 target 0 lun 0 cd0: <MATSHITA CDRW/DVD UJDA740 1.00> Removable CD-ROM SCSI-0 device cd0: 16.000MB/s transfers cd0: Attempt to query device size failed: NOT READY, Medium not present - tray closed The drive could now be accessed via the /dev/cd0 device name, for example to mount a CD-ROM on /mnt, just type the following: &prompt.root; mount -t cd9660 /dev/cd0 /mnt As root, you can run the following command to get the SCSI address of the burner: &prompt.root; camcontrol devlist <MATSHITA CDRW/DVD UJDA740 1.00> at scbus1 target 0 lun 0 (pass0,cd0) So 1,0,0 will be the SCSI address to use with &man.cdrecord.1; and other SCSI application. For more information about ATAPI/CAM and SCSI system, refer to the &man.atapicam.4; and &man.cam.4; manual pages. Marc Fonvieille Contributed by Andy Polyakov With inputs from Creating and Using Optical Media (DVDs) DVD burning Introduction Compared to the CD, the DVD is the next generation of optical media storage technology. The DVD can hold more data than any CD and is nowadays the standard for video publishing. Five physical recordable formats can be defined for what we will call a recordable DVD: DVD-R: This was the first DVD recordable format available. The DVD-R standard is defined by the DVD Forum. This format is write once. DVD-RW: This is the rewriteable version of the DVD-R standard. A DVD-RW can be rewritten about 1000 times. DVD-RAM: This is also a rewriteable format supported by the DVD Forum. A DVD-RAM can be seen as a removable hard drive. However, this media is not compatible with most DVD-ROM drives and DVD-Video players; only a few DVD writers support the DVD-RAM format. DVD+RW: This is a rewriteable format defined by the DVD+RW Alliance. A DVD+RW can be rewritten about 1000 times. DVD+R: This format is the write once variation of the DVD+RW format. A single layer recordable DVD can hold up to 4,700,000,000 bytes which is actually 4.38 GB or 4485 MB (1 kilobyte is 1024 bytes). A distinction must be made between the physical media and the application. For example, a DVD-Video is a specific file layout that can be written on any recordable DVD physical media: DVD-R, DVD+R, DVD-RW etc. Before choosing the type of media, you must be sure that both the burner and the DVD-Video player (a standalone player or a DVD-ROM drive on a computer) are compatible with the media under consideration. Configuration The program &man.growisofs.1; will be used to perform DVD recording. This command is part of the dvd+rw-tools utilities (sysutils/dvd+rw-tools). The dvd+rw-tools support all DVD media types. These tools use the SCSI subsystem to access to the devices, therefore the ATAPI/CAM support must be added to your kernel. If your burner uses the USB interface this addition is useless, and you should read the for more details on USB devices configuration. You also have to enable DMA access for ATAPI devices, this can be done in adding the following line to the /boot/loader.conf file: hw.ata.atapi_dma="1" Before attempting to use the dvd+rw-tools you should consult the dvd+rw-tools' hardware compatibility notes for any information related to your DVD burner. If you want a graphical user interface, you should have a look to K3b (sysutils/k3b) which provides a user friendly interface to &man.growisofs.1; and many others burning tools. Burning Data DVDs The &man.growisofs.1; command is a frontend to mkisofs, it will invoke &man.mkisofs.8; to create the file system layout and will perform the write on the DVD. This means you do not need to create an image of the data before the burning process. To burn onto a DVD+R or a DVD-R the data from the /path/to/data directory, use the + class="directory">/path/to/data directory, use the following command: &prompt.root; growisofs -dvd-compat -Z /dev/cd0 -J -R /path/to/data The options are passed to &man.mkisofs.8; for the file system creation (in this case: an ISO 9660 file system with Joliet and Rock Ridge extensions), consult the &man.mkisofs.8; manual page for more details. The option is used for the initial session recording in any case: multiple sessions or not. The DVD device, /dev/cd0, must be changed according to your configuration. The parameter will close the disk, the recording will be unappendable. In return this should provide better media compatibility with DVD-ROM drives. It is also possible to burn a pre-mastered image, for example to burn the image imagefile.iso, we will run: &prompt.root; growisofs -dvd-compat -Z /dev/cd0=imagefile.iso The write speed should be detected and automatically set according to the media and the drive being used. If you want to force the write speed, use the parameter. For more information, read the &man.growisofs.1; manual page. DVD DVD-Video Burning a DVD-Video A DVD-Video is a specific file layout based on ISO 9660 and the micro-UDF (M-UDF) specifications. The DVD-Video also presents a specific data structure hierarchy, it is the reason why you need a particular program such as multimedia/dvdauthor to author the DVD. If you already have an image of the DVD-Video file system, just burn it in the same way as for any image, see the previous section for an example. If you have made the DVD authoring and the result is in, for example, the directory - /path/to/video, the + /path/to/video, the following command should be used to burn the DVD-Video: &prompt.root; growisofs -Z /dev/cd0 -dvd-video /path/to/video The option will be passed down to &man.mkisofs.8; and will instruct it to create a DVD-Video file system layout. Beside this, the option implies &man.growisofs.1; option. DVD DVD+RW Using a DVD+RW Unlike CD-RW, a virgin DVD+RW needs to be formatted before first use. The &man.growisofs.1; program will take care of it automatically whenever appropriate, which is the recommended way. However you can use the dvd+rw-format command to format the DVD+RW: &prompt.root; dvd+rw-format /dev/cd0 You need to perform this operation just once, keep in mind that only virgin DVD+RW medias need to be formatted. Then you can burn the DVD+RW in the way seen in previous sections. If you want to burn new data (burn a totally new file system not append some data) onto a DVD+RW, you do not need to blank it, you just have to write over the previous recording (in performing a new initial session), like this: &prompt.root; growisofs -Z /dev/cd0 -J -R /path/to/newdata DVD+RW format offers the possibility to easily append data to a previous recording. The operation consists in merging a new session to the existing one, it is not multisession writing, &man.growisofs.1; will grow the ISO 9660 file system present on the media. For example, if we want to append data to our previous DVD+RW, we have to use the following: &prompt.root; growisofs -M /dev/cd0 -J -R /path/to/nextdata The same &man.mkisofs.8; options we used to burn the initial session should be used during next writes. You may want to use the option if you want better media compatibility with DVD-ROM drives. In the DVD+RW case, this will not prevent you from adding data. If for any reason you really want to blank the media, do the following: &prompt.root; growisofs -Z /dev/cd0=/dev/zero DVD DVD-RW Using a DVD-RW A DVD-RW accepts two disc formats: the incremental sequential one and the restricted overwrite. By default DVD-RW discs are in sequential format. A virgin DVD-RW can be directly written without the need of a formatting operation, however a non-virgin DVD-RW in sequential format needs to be blanked before to be able to write a new initial session. To blank a DVD-RW in sequential mode, run: &prompt.root; dvd+rw-format -blank=full /dev/cd0 A full blanking () will take about one hour on a 1x media. A fast blanking can be performed using the option if the DVD-RW will be recorded in Disk-At-Once (DAO) mode. To burn the DVD-RW in DAO mode, use the command: &prompt.root; growisofs -use-the-force-luke=dao -Z /dev/cd0=imagefile.iso The option should not be required since &man.growisofs.1; attempts to detect minimally (fast blanked) media and engage DAO write. In fact one should use restricted overwrite mode with any DVD-RW, this format is more flexible than the default incremental sequential one. To write data on a sequential DVD-RW, use the same instructions as for the other DVD formats: &prompt.root; growisofs -Z /dev/cd0 -J -R /path/to/data If you want to append some data to your previous recording, you will have to use the &man.growisofs.1; option. However, if you perform data addition on a DVD-RW in incremental sequential mode, a new session will be created on the disc and the result will be a multi-session disc. A DVD-RW in restricted overwrite format does not need to be blanked before a new initial session, you just have to overwrite the disc with the option, this is similar to the DVD+RW case. It is also possible to grow an existing ISO 9660 file system written on the disc in a same way as for a DVD+RW with the option. The result will be a one-session DVD. To put a DVD-RW in the restricted overwrite format, the following command must be used: &prompt.root; dvd+rw-format /dev/cd0 To change back to the sequential format use: &prompt.root; dvd+rw-format -blank=full /dev/cd0 Multisession Very few DVD-ROM drives support multisession DVDs, they will most of time, hopefully, only read the first session. DVD+R, DVD-R and DVD-RW in sequential format can accept multiple sessions, the notion of multiple sessions does not exist for the DVD+RW and the DVD-RW restricted overwrite formats. Using the following command after an initial (non-closed) session on a DVD+R, DVD-R, or DVD-RW in sequential format, will add a new session to the disc: &prompt.root; growisofs -M /dev/cd0 -J -R /path/to/nextdata Using this command line with a DVD+RW or a DVD-RW in restricted overwrite mode, will append data in merging the new session to the existing one. The result will be a single-session disc. This is the way used to add data after an initial write on these medias. Some space on the media is used between each session for end and start of sessions. Therefore, one should add sessions with large amount of data to optimize media space. The number of sessions is limited to 154 for a DVD+R, about 2000 for a DVD-R, and 127 for a DVD+R Double Layer. For More Information To obtain more information about a DVD, the dvd+rw-mediainfo /dev/cd0 command can be ran with the disc in the drive. More information about the dvd+rw-tools can be found in the &man.growisofs.1; manual page, on the dvd+rw-tools web site and in the cdwrite mailing list archives. The dvd+rw-mediainfo output of the resulting recording or the media with issues is mandatory for any problem report. Without this output, it will be quite impossible to help you. Julio Merino Original work by Martin Karlsson Rewritten by Creating and Using Floppy Disks Storing data on floppy disks is sometimes useful, for example when one does not have any other removable storage media or when one needs to transfer small amounts of data to another computer. This section will explain how to use floppy disks in FreeBSD. It will primarily cover formatting and usage of 3.5inch DOS floppies, but the concepts are similar for other floppy disk formats. Formatting Floppies The Device Floppy disks are accessed through entries in /dev, just like other devices. To access the raw floppy disk in 4.X and earlier releases, one uses /dev/fdN, where N stands for the drive number, usually 0, or /dev/fdNX, where X stands for a letter. In 5.0 or newer releases, simply use /dev/fdN. The Disk Size in 4.X and Earlier Releases There are also /dev/fdN.size devices, where size is a floppy disk size in kilobytes. These entries are used at low-level format time to determine the disk size. 1440kB is the size that will be used in the following examples. Sometimes the entries under /dev will have to be (re)created. To do that, issue: &prompt.root; cd /dev && ./MAKEDEV "fd*" The Disk Size in 5.0 and Newer Releases In 5.0, &man.devfs.5; will automatically manage device nodes in /dev, so use of MAKEDEV is not necessary. The desired disk size is passed to &man.fdformat.1; through the flag. Supported sizes are listed in &man.fdcontrol.8;, but be advised that 1440kB is what works best. Formatting A floppy disk needs to be low-level formated before it can be used. This is usually done by the vendor, but formatting is a good way to check media integrity. Although it is possible to force larger (or smaller) disk sizes, 1440kB is what most floppy disks are designed for. To low-level format the floppy disk you need to use &man.fdformat.1;. This utility expects the device name as an argument. Make note of any error messages, as these can help determine if the disk is good or bad. Formatting in 4.X and Earlier Releases Use the /dev/fdN.size devices to format the floppy. Insert a new 3.5inch floppy disk in your drive and issue: &prompt.root; /usr/sbin/fdformat /dev/fd0.1440 Formatting in 5.0 and Newer Releases Use the /dev/fdN devices to format the floppy. Insert a new 3.5inch floppy disk in your drive and issue: &prompt.root; /usr/sbin/fdformat -f 1440 /dev/fd0 The Disk Label After low-level formatting the disk, you will need to place a disk label on it. This disk label will be destroyed later, but it is needed by the system to determine the size of the disk and its geometry later. The new disk label will take over the whole disk, and will contain all the proper information about the geometry of the floppy. The geometry values for the disk label are listed in /etc/disktab. You can run now &man.disklabel.8; like so: &prompt.root; /sbin/disklabel -B -r -w /dev/fd0 fd1440 Since &os; 5.1-RELEASE, the &man.bsdlabel.8; utility replaces the old &man.disklabel.8; program. With &man.bsdlabel.8; a number of obsolete options and parameters have been retired; in the example above the option should be removed. For more information, please refer to the &man.bsdlabel.8; manual page. The File System Now the floppy is ready to be high-level formated. This will place a new file system on it, which will let FreeBSD read and write to the disk. After creating the new file system, the disk label is destroyed, so if you want to reformat the disk, you will have to recreate the disk label. The floppy's file system can be either UFS or FAT. FAT is generally a better choice for floppies. To put a new file system on the floppy, issue: &prompt.root; /sbin/newfs_msdos /dev/fd0 The disk is now ready for use. Using the Floppy To use the floppy, mount it with &man.mount.msdos.8; (in 4.X and earlier releases) or &man.mount.msdosfs.8; (in 5.0 or newer releases). One can also use emulators/mtools from the ports collection. Creating and Using Data Tapes tape media The major tape media are the 4mm, 8mm, QIC, mini-cartridge and DLT. 4mm (DDS: Digital Data Storage) tape media DDS (4mm) tapes tape media QIC tapes 4mm tapes are replacing QIC as the workstation backup media of choice. This trend accelerated greatly when Conner purchased Archive, a leading manufacturer of QIC drives, and then stopped production of QIC drives. 4mm drives are small and quiet but do not have the reputation for reliability that is enjoyed by 8mm drives. The cartridges are less expensive and smaller (3 x 2 x 0.5 inches, 76 x 51 x 12 mm) than 8mm cartridges. 4mm, like 8mm, has comparatively short head life for the same reason, both use helical scan. Data throughput on these drives starts ~150 kB/s, peaking at ~500 kB/s. Data capacity starts at 1.3 GB and ends at 2.0 GB. Hardware compression, available with most of these drives, approximately doubles the capacity. Multi-drive tape library units can have 6 drives in a single cabinet with automatic tape changing. Library capacities reach 240 GB. The DDS-3 standard now supports tape capacities up to 12 GB (or 24 GB compressed). 4mm drives, like 8mm drives, use helical-scan. All the benefits and drawbacks of helical-scan apply to both 4mm and 8mm drives. Tapes should be retired from use after 2,000 passes or 100 full backups. 8mm (Exabyte) tape media Exabyte (8mm) tapes 8mm tapes are the most common SCSI tape drives; they are the best choice of exchanging tapes. Nearly every site has an Exabyte 2 GB 8mm tape drive. 8mm drives are reliable, convenient and quiet. Cartridges are inexpensive and small (4.8 x 3.3 x 0.6 inches; 122 x 84 x 15 mm). One downside of 8mm tape is relatively short head and tape life due to the high rate of relative motion of the tape across the heads. Data throughput ranges from ~250 kB/s to ~500 kB/s. Data sizes start at 300 MB and go up to 7 GB. Hardware compression, available with most of these drives, approximately doubles the capacity. These drives are available as single units or multi-drive tape libraries with 6 drives and 120 tapes in a single cabinet. Tapes are changed automatically by the unit. Library capacities reach 840+ GB. The Exabyte Mammoth model supports 12 GB on one tape (24 GB with compression) and costs approximately twice as much as conventional tape drives. Data is recorded onto the tape using helical-scan, the heads are positioned at an angle to the media (approximately 6 degrees). The tape wraps around 270 degrees of the spool that holds the heads. The spool spins while the tape slides over the spool. The result is a high density of data and closely packed tracks that angle across the tape from one edge to the other. QIC tape media QIC-150 QIC-150 tapes and drives are, perhaps, the most common tape drive and media around. QIC tape drives are the least expensive serious backup drives. The downside is the cost of media. QIC tapes are expensive compared to 8mm or 4mm tapes, up to 5 times the price per GB data storage. But, if your needs can be satisfied with a half-dozen tapes, QIC may be the correct choice. QIC is the most common tape drive. Every site has a QIC drive of some density or another. Therein lies the rub, QIC has a large number of densities on physically similar (sometimes identical) tapes. QIC drives are not quiet. These drives audibly seek before they begin to record data and are clearly audible whenever reading, writing or seeking. QIC tapes measure (6 x 4 x 0.7 inches; 15.2 x 10.2 x 1.7 mm). Data throughput ranges from ~150 kB/s to ~500 kB/s. Data capacity ranges from 40 MB to 15 GB. Hardware compression is available on many of the newer QIC drives. QIC drives are less frequently installed; they are being supplanted by DAT drives. Data is recorded onto the tape in tracks. The tracks run along the long axis of the tape media from one end to the other. The number of tracks, and therefore the width of a track, varies with the tape's capacity. Most if not all newer drives provide backward-compatibility at least for reading (but often also for writing). QIC has a good reputation regarding the safety of the data (the mechanics are simpler and more robust than for helical scan drives). Tapes should be retired from use after 5,000 backups. DLT tape media DLT DLT has the fastest data transfer rate of all the drive types listed here. The 1/2" (12.5mm) tape is contained in a single spool cartridge (4 x 4 x 1 inches; 100 x 100 x 25 mm). The cartridge has a swinging gate along one entire side of the cartridge. The drive mechanism opens this gate to extract the tape leader. The tape leader has an oval hole in it which the drive uses to hook the tape. The take-up spool is located inside the tape drive. All the other tape cartridges listed here (9 track tapes are the only exception) have both the supply and take-up spools located inside the tape cartridge itself. Data throughput is approximately 1.5 MB/s, three times the throughput of 4mm, 8mm, or QIC tape drives. Data capacities range from 10 GB to 20 GB for a single drive. Drives are available in both multi-tape changers and multi-tape, multi-drive tape libraries containing from 5 to 900 tapes over 1 to 20 drives, providing from 50 GB to 9 TB of storage. With compression, DLT Type IV format supports up to 70 GB capacity. Data is recorded onto the tape in tracks parallel to the direction of travel (just like QIC tapes). Two tracks are written at once. Read/write head lifetimes are relatively long; once the tape stops moving, there is no relative motion between the heads and the tape. AIT tape media AIT AIT is a new format from Sony, and can hold up to 50 GB (with compression) per tape. The tapes contain memory chips which retain an index of the tape's contents. This index can be rapidly read by the tape drive to determine the position of files on the tape, instead of the several minutes that would be required for other tapes. Software such as SAMS:Alexandria can operate forty or more AIT tape libraries, communicating directly with the tape's memory chip to display the contents on screen, determine what files were backed up to which tape, locate the correct tape, load it, and restore the data from the tape. Libraries like this cost in the region of $20,000, pricing them a little out of the hobbyist market. Using a New Tape for the First Time The first time that you try to read or write a new, completely blank tape, the operation will fail. The console messages should be similar to: sa0(ncr1:4:0): NOT READY asc:4,1 sa0(ncr1:4:0): Logical unit is in process of becoming ready The tape does not contain an Identifier Block (block number 0). All QIC tape drives since the adoption of QIC-525 standard write an Identifier Block to the tape. There are two solutions: mt fsf 1 causes the tape drive to write an Identifier Block to the tape. Use the front panel button to eject the tape. Re-insert the tape and dump data to the tape. dump will report DUMP: End of tape detected and the console will show: HARDWARE FAILURE info:280 asc:80,96. rewind the tape using: mt rewind. Subsequent tape operations are successful. Backups to Floppies Can I Use Floppies for Backing Up My Data? backup floppies floppy disks Floppy disks are not really a suitable media for making backups as: The media is unreliable, especially over long periods of time. Backing up and restoring is very slow. They have a very limited capacity (the days of backing up an entire hard disk onto a dozen or so floppies has long since passed). However, if you have no other method of backing up your data then floppy disks are better than no backup at all. If you do have to use floppy disks then ensure that you use good quality ones. Floppies that have been lying around the office for a couple of years are a bad choice. Ideally use new ones from a reputable manufacturer. So How Do I Backup My Data to Floppies? The best way to backup to floppy disk is to use &man.tar.1; with the (multi volume) option, which allows backups to span multiple floppies. To backup all the files in the current directory and sub-directory use this (as root): &prompt.root; tar Mcvf /dev/fd0 * When the first floppy is full &man.tar.1; will prompt you to insert the next volume (because &man.tar.1; is media independent it refers to volumes; in this context it means floppy disk). Prepare volume #2 for /dev/fd0 and hit return: This is repeated (with the volume number incrementing) until all the specified files have been archived. Can I Compress My Backups? tar gzip compression Unfortunately, &man.tar.1; will not allow the option to be used for multi-volume archives. You could, of course, &man.gzip.1; all the files, &man.tar.1; them to the floppies, then &man.gunzip.1; the files again! How Do I Restore My Backups? To restore the entire archive use: &prompt.root; tar Mxvf /dev/fd0 There are two ways that you can use to restore only specific files. First, you can start with the first floppy and use: &prompt.root; tar Mxvf /dev/fd0 filename The utility &man.tar.1; will prompt you to insert subsequent floppies until it finds the required file. Alternatively, if you know which floppy the file is on then you can simply insert that floppy and use the same command as above. Note that if the first file on the floppy is a continuation from the previous one then &man.tar.1; will warn you that it cannot restore it, even if you have not asked it to! Backup Basics The three major backup programs are &man.dump.8;, &man.tar.1;, and &man.cpio.1;. Dump and Restore backup software dump / restore dump restore The traditional &unix; backup programs are dump and restore. They operate on the drive as a collection of disk blocks, below the abstractions of files, links and directories that are created by the file systems. dump backs up an entire file system on a device. It is unable to backup only part of a file system or a directory tree that spans more than one file system. dump does not write files and directories to tape, but rather writes the raw data blocks that comprise files and directories. If you use dump on your root directory, you would not back up /home, /usr or many other directories since these are typically mount points for other file systems or symbolic links into those file systems. dump has quirks that remain from its early days in Version 6 of AT&T UNIX (circa 1975). The default parameters are suitable for 9-track tapes (6250 bpi), not the high-density media available today (up to 62,182 ftpi). These defaults must be overridden on the command line to utilize the capacity of current tape drives. .rhosts It is also possible to backup data across the network to a tape drive attached to another computer with rdump and rrestore. Both programs rely upon rcmd and ruserok to access the remote tape drive. Therefore, the user performing the backup must be listed in the .rhosts file on the remote computer. The arguments to rdump and rrestore must be suitable to use on the remote computer. When rdumping from a FreeBSD computer to an Exabyte tape drive connected to a Sun called komodo, use: &prompt.root; /sbin/rdump 0dsbfu 54000 13000 126 komodo:/dev/nsa8 /dev/da0a 2>&1 Beware: there are security implications to allowing .rhosts authentication. Evaluate your situation carefully. It is also possible to use dump and restore in a more secure fashion over ssh. Using <command>dump</command> over <application>ssh</application> &prompt.root; /sbin/dump -0uan -f - /usr | gzip -2 | ssh -c blowfish \ targetuser@targetmachine.example.com dd of=/mybigfiles/dump-usr-l0.gz Or using dump's built-in method, setting the environment variable RSH: Using <command>dump</command> over <application>ssh</application> with <envar>RSH</envar> set &prompt.root; RSH=/usr/bin/ssh /sbin/dump -0uan -f targetuser@targetmachine.example.com:/dev/sa0 <command>tar</command> backup software tar &man.tar.1; also dates back to Version 6 of AT&T UNIX (circa 1975). tar operates in cooperation with the file system; tar writes files and directories to tape. tar does not support the full range of options that are available from &man.cpio.1;, but tar does not require the unusual command pipeline that cpio uses. tar Most versions of tar do not support backups across the network. The GNU version of tar, which FreeBSD utilizes, supports remote devices using the same syntax as rdump. To tar to an Exabyte tape drive connected to a Sun called komodo, use: &prompt.root; /usr/bin/tar cf komodo:/dev/nsa8 . 2>&1 For versions without remote device support, you can use a pipeline and rsh to send the data to a remote tape drive. &prompt.root; tar cf - . | rsh hostname dd of=tape-device obs=20b If you are worried about the security of backing up over a network you should use the ssh command instead of rsh. <command>cpio</command> backup software cpio &man.cpio.1; is the original &unix; file interchange tape program for magnetic media. cpio has options (among many others) to perform byte-swapping, write a number of different archive formats, and pipe the data to other programs. This last feature makes cpio an excellent choice for installation media. cpio does not know how to walk the directory tree and a list of files must be provided through stdin. cpio cpio does not support backups across the network. You can use a pipeline and rsh to send the data to a remote tape drive. &prompt.root; for f in directory_list; do find $f >> backup.list done &prompt.root; cpio -v -o --format=newc < backup.list | ssh user@host "cat > backup_device" Where directory_list is the list of directories you want to back up, user@host is the user/hostname combination that will be performing the backups, and backup_device is where the backups should be written to (e.g., /dev/nsa0). <command>pax</command> backup software pax pax POSIX IEEE &man.pax.1; is IEEE/&posix;'s answer to tar and cpio. Over the years the various versions of tar and cpio have gotten slightly incompatible. So rather than fight it out to fully standardize them, &posix; created a new archive utility. pax attempts to read and write many of the various cpio and tar formats, plus new formats of its own. Its command set more resembles cpio than tar. <application>Amanda</application> backup software Amanda Amanda Amanda (Advanced Maryland Network Disk Archiver) is a client/server backup system, rather than a single program. An Amanda server will backup to a single tape drive any number of computers that have Amanda clients and a network connection to the Amanda server. A common problem at sites with a number of large disks is that the length of time required to backup to data directly to tape exceeds the amount of time available for the task. Amanda solves this problem. Amanda can use a holding disk to backup several file systems at the same time. Amanda creates archive sets: a group of tapes used over a period of time to create full backups of all the file systems listed in Amanda's configuration file. The archive set also contains nightly incremental (or differential) backups of all the file systems. Restoring a damaged file system requires the most recent full backup and the incremental backups. The configuration file provides fine control of backups and the network traffic that Amanda generates. Amanda will use any of the above backup programs to write the data to tape. Amanda is available as either a port or a package, it is not installed by default. Do Nothing Do nothing is not a computer program, but it is the most widely used backup strategy. There are no initial costs. There is no backup schedule to follow. Just say no. If something happens to your data, grin and bear it! If your time and your data is worth little to nothing, then Do nothing is the most suitable backup program for your computer. But beware, &unix; is a useful tool, you may find that within six months you have a collection of files that are valuable to you. Do nothing is the correct backup method for /usr/obj and other directory trees that can be exactly recreated by your computer. An example is the files that comprise the HTML or &postscript; version of this Handbook. These document formats have been created from SGML input files. Creating backups of the HTML or &postscript; files is not necessary. The SGML files are backed up regularly. Which Backup Program Is Best? LISA &man.dump.8; Period. Elizabeth D. Zwicky torture tested all the backup programs discussed here. The clear choice for preserving all your data and all the peculiarities of &unix; file systems is dump. Elizabeth created file systems containing a large variety of unusual conditions (and some not so unusual ones) and tested each program by doing a backup and restore of those file systems. The peculiarities included: files with holes, files with holes and a block of nulls, files with funny characters in their names, unreadable and unwritable files, devices, files that change size during the backup, files that are created/deleted during the backup and more. She presented the results at LISA V in Oct. 1991. See torture-testing Backup and Archive Programs. Emergency Restore Procedure Before the Disaster There are only four steps that you need to perform in preparation for any disaster that may occur. disklabel First, print the disklabel from each of your disks (e.g. disklabel da0 | lpr), your file system table (/etc/fstab) and all boot messages, two copies of each. fix-it floppies Second, determine that the boot and fix-it floppies (boot.flp and fixit.flp) have all your devices. The easiest way to check is to reboot your machine with the boot floppy in the floppy drive and check the boot messages. If all your devices are listed and functional, skip on to step three. Otherwise, you have to create two custom bootable floppies which have a kernel that can mount all of your disks and access your tape drive. These floppies must contain: fdisk, disklabel, newfs, mount, and whichever backup program you use. These programs must be statically linked. If you use dump, the floppy must contain restore. Third, create backup tapes regularly. Any changes that you make after your last backup may be irretrievably lost. Write-protect the backup tapes. Fourth, test the floppies (either boot.flp and fixit.flp or the two custom bootable floppies you made in step two.) and backup tapes. Make notes of the procedure. Store these notes with the bootable floppy, the printouts and the backup tapes. You will be so distraught when restoring that the notes may prevent you from destroying your backup tapes (How? In place of tar xvf /dev/sa0, you might accidentally type tar cvf /dev/sa0 and over-write your backup tape). For an added measure of security, make bootable floppies and two backup tapes each time. Store one of each at a remote location. A remote location is NOT the basement of the same office building. A number of firms in the World Trade Center learned this lesson the hard way. A remote location should be physically separated from your computers and disk drives by a significant distance. A Script for Creating a Bootable Floppy /mnt/sbin/init gzip -c -best /sbin/fsck > /mnt/sbin/fsck gzip -c -best /sbin/mount > /mnt/sbin/mount gzip -c -best /sbin/halt > /mnt/sbin/halt gzip -c -best /sbin/restore > /mnt/sbin/restore gzip -c -best /bin/sh > /mnt/bin/sh gzip -c -best /bin/sync > /mnt/bin/sync cp /root/.profile /mnt/root cp -f /dev/MAKEDEV /mnt/dev chmod 755 /mnt/dev/MAKEDEV chmod 500 /mnt/sbin/init chmod 555 /mnt/sbin/fsck /mnt/sbin/mount /mnt/sbin/halt chmod 555 /mnt/bin/sh /mnt/bin/sync chmod 6555 /mnt/sbin/restore # # create the devices nodes # cd /mnt/dev ./MAKEDEV std ./MAKEDEV da0 ./MAKEDEV da1 ./MAKEDEV da2 ./MAKEDEV sa0 ./MAKEDEV pty0 cd / # # create minimum file system table # cat > /mnt/etc/fstab < /mnt/etc/passwd < /mnt/etc/master.passwd < After the Disaster The key question is: did your hardware survive? You have been doing regular backups so there is no need to worry about the software. If the hardware has been damaged, the parts should be replaced before attempting to use the computer. If your hardware is okay, check your floppies. If you are using a custom boot floppy, boot single-user (type -s at the boot: prompt). Skip the following paragraph. If you are using the boot.flp and fixit.flp floppies, keep reading. Insert the boot.flp floppy in the first floppy drive and boot the computer. The original install menu will be displayed on the screen. Select the Fixit--Repair mode with CDROM or floppy. option. Insert the fixit.flp when prompted. restore and the other programs that you need are located in /mnt2/stand. Recover each file system separately. mount root partition disklabel newfs Try to mount (e.g. mount /dev/da0a /mnt) the root partition of your first disk. If the disklabel was damaged, use disklabel to re-partition and label the disk to match the label that you printed and saved. Use newfs to re-create the file systems. Re-mount the root partition of the floppy read-write (mount -u -o rw /mnt). Use your backup program and backup tapes to recover the data for this file system (e.g. restore vrf /dev/sa0). Unmount the file system (e.g. umount /mnt). Repeat for each file system that was damaged. Once your system is running, backup your data onto new tapes. Whatever caused the crash or data loss may strike again. Another hour spent now may save you from further distress later. * I Did Not Prepare for the Disaster, What Now? ]]> Marc Fonvieille Reorganized and enhanced by Network, Memory, and File-Backed File Systems virtual disks disks virtual Aside from the disks you physically insert into your computer: floppies, CDs, hard drives, and so forth; other forms of disks are understood by FreeBSD - the virtual disks. NFS Coda disks memory These include network file systems such as the Network File System and Coda, memory-based file systems and file-backed file systems. According to the FreeBSD version you run, you will have to use different tools for creation and use of file-backed and memory-based file systems. The FreeBSD 4.X users will have to use &man.MAKEDEV.8; to create the required devices. FreeBSD 5.0 and later use &man.devfs.5; to allocate device nodes transparently for the user. File-Backed File System under FreeBSD 4.X disks file-backed (4.X) The utility &man.vnconfig.8; configures and enables vnode pseudo-disk devices. A vnode is a representation of a file, and is the focus of file activity. This means that &man.vnconfig.8; uses files to create and operate a file system. One possible use is the mounting of floppy or CD images kept in files. To use &man.vnconfig.8;, you need &man.vn.4; support in your kernel configuration file: pseudo-device vn To mount an existing file system image: Using vnconfig to Mount an Existing File System Image under FreeBSD 4.X &prompt.root; vnconfig vn0 diskimage &prompt.root; mount /dev/vn0c /mnt To create a new file system image with &man.vnconfig.8;: Creating a New File-Backed Disk with <command>vnconfig</command> &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records out &prompt.root; vnconfig -s labels -c vn0 newimage &prompt.root; disklabel -r -w vn0 auto &prompt.root; newfs vn0c Warning: 2048 sector(s) in last cylinder unallocated /dev/vn0c: 10240 sectors in 3 cylinders of 1 tracks, 4096 sectors 5.0MB in 1 cyl groups (16 c/g, 32.00MB/g, 1280 i/g) super-block backups (for fsck -b #) at: 32 &prompt.root; mount /dev/vn0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/vn0c 4927 1 4532 0% /mnt File-Backed File System under FreeBSD 5.X disks file-backed (5.X) The utility &man.mdconfig.8; is used to configure and enable memory disks, &man.md.4;, under FreeBSD 5.X. To use &man.mdconfig.8;, you have to load &man.md.4; module or to add the support in your kernel configuration file: device md The &man.mdconfig.8; command supports three kinds of memory backed virtual disks: memory disks allocated with &man.malloc.9;, memory disks using a file or swap space as backing. One possible use is the mounting of floppy or CD images kept in files. To mount an existing file system image: Using <command>mdconfig</command> to Mount an Existing File System Image under FreeBSD 5.X &prompt.root; mdconfig -a -t vnode -f diskimage -u 0 &prompt.root; mount /dev/md0 /mnt To create a new file system image with &man.mdconfig.8;: Creating a New File-Backed Disk with <command>mdconfig</command> &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records out &prompt.root; mdconfig -a -t vnode -f newimage -u 0 &prompt.root; disklabel -r -w md0 auto &prompt.root; newfs md0c /dev/md0c: 5.0MB (10240 sectors) block size 16384, fragment size 2048 using 4 cylinder groups of 1.27MB, 81 blks, 256 inodes. super-block backups (for fsck -b #) at: 32, 2624, 5216, 7808 &prompt.root; mount /dev/md0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0c 4846 2 4458 0% /mnt If you do not specify the unit number with the option, &man.mdconfig.8; will use the &man.md.4; automatic allocation to select an unused device. The name of the allocated unit will be output on stdout like md4. For more details about &man.mdconfig.8;, please refer to the manual page. Since &os; 5.1-RELEASE, the &man.bsdlabel.8; utility replaces the old &man.disklabel.8; program. With &man.bsdlabel.8; a number of obsolete options and parameters have been retired; in the example above the option should be removed. For more information, please refer to the &man.bsdlabel.8; manual page. The utility &man.mdconfig.8; is very useful, however it asks many command lines to create a file-backed file system. FreeBSD 5.0 also comes with a tool called &man.mdmfs.8;, this program configures a &man.md.4; disk using &man.mdconfig.8;, puts a UFS file system on it using &man.newfs.8;, and mounts it using &man.mount.8;. For example, if you want to create and mount the same file system image as above, simply type the following: Configure and Mount a File-Backed Disk with <command>mdmfs</command> &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records out &prompt.root; mdmfs -F newimage -s 5m md0 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0 4846 2 4458 0% /mnt If you use the option without unit number, &man.mdmfs.8; will use &man.md.4; auto-unit feature to automatically select an unused device. For more details about &man.mdmfs.8;, please refer to the manual page. Memory-Based File System under FreeBSD 4.X disks memory file system (4.X) The &man.md.4; driver is a simple, efficient means to create memory file systems under FreeBSD 4.X. &man.malloc.9; is used to allocate the memory. Simply take a file system you have prepared with, for example, &man.vnconfig.8;, and: md Memory Disk under FreeBSD 4.X &prompt.root; dd if=newimage of=/dev/md0 5120+0 records in 5120+0 records out &prompt.root; mount /dev/md0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0c 4927 1 4532 0% /mnt For more details, please refer to &man.md.4; manual page. Memory-Based File System under FreeBSD 5.X disks memory file system (5.X) The same tools are used for memory-based and file-backed file systems: &man.mdconfig.8; or &man.mdmfs.8;. The storage for memory-based file system is allocated with &man.malloc.9;. Creating a New Memory-Based Disk with <command>mdconfig</command> &prompt.root; mdconfig -a -t malloc -s 5m -u 1 &prompt.root; newfs -U md1 /dev/md1: 5.0MB (10240 sectors) block size 16384, fragment size 2048 using 4 cylinder groups of 1.27MB, 81 blks, 256 inodes. with soft updates super-block backups (for fsck -b #) at: 32, 2624, 5216, 7808 &prompt.root; mount /dev/md1 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md1 4846 2 4458 0% /mnt Creating a New Memory-Based Disk with <command>mdmfs</command> &prompt.root; mdmfs -M -s 5m md2 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md2 4846 2 4458 0% /mnt Instead of using a &man.malloc.9; backed file system, it is possible to use swap, for that just replace with in the command line of &man.mdconfig.8;. The &man.mdmfs.8; utility by default (without ) creates a swap-based disk. For more details, please refer to &man.mdconfig.8; and &man.mdmfs.8; manual pages. Detaching a Memory Disk from the System disks detaching a memory disk When a memory-based or file-based file system is not used, you should release all resources to the system. The first thing to do is to unmount the file system, then use &man.mdconfig.8; to detach the disk from the system and release the resources. For example to detach and free all resources used by /dev/md4: &prompt.root; mdconfig -d -u 4 It is possible to list information about configured &man.md.4; devices in using the command mdconfig -l. For FreeBSD 4.X, &man.vnconfig.8; is used to detach the device. For example to detach and free all resources used by /dev/vn4: &prompt.root; vnconfig -u vn4 Tom Rhodes Contributed by File System Snapshots file systems snapshots FreeBSD 5.0 offers a new feature in conjunction with Soft Updates: File system snapshots. Snapshots allow a user to create images of specified file systems, and treat them as a file. Snapshot files must be created in the file system that the action is performed on, and a user may create no more than 20 snapshots per file system. Active snapshots are recorded in the superblock so they are persistent across unmount and remount operations along with system reboots. When a snapshot is no longer required, it can be removed with the standard &man.rm.1; command. Snapshots may be removed in any order, however all the used space may not be acquired because another snapshot will possibly claim some of the released blocks. During initial creation, the flag (see the &man.chflags.1; manual page) is set to ensure that even root cannot write to the snapshot. The &man.unlink.1; command makes an exception for snapshot files since it allows them to be removed with the flag set, so it is not necessary to clear the flag before removing a snapshot file. Snapshots are created with the &man.mount.8; command. To place a snapshot of /var in the file /var/snapshot/snap use the following command: &prompt.root; mount -u -o snapshot /var/snapshot/snap /var Alternatively, you can use &man.mksnap.ffs.8; to create a snapshot: &prompt.root; mksnap_ffs /var /var/snapshot/snap Once a snapshot has been created, it has several uses: Some administrators will use a snapshot file for backup purposes, because the snapshot can be transfered to CDs or tape. File integrity, &man.fsck.8; may be ran on the snapshot. Assuming that the file system was clean when it was mounted, you should always get a clean (and unchanging) result. This is essentially what the background &man.fsck.8; process does. Run the &man.dump.8; utility on the snapshot. A dump will be returned that is consistent with the file system and the timestamp of the snapshot. &man.dump.8; can also take a snapshot, create a dump image and then remove the snapshot in one command using the flag. &man.mount.8; the snapshot as a frozen image of the file system. To &man.mount.8; the snapshot /var/snapshot/snap run: &prompt.root; mdconfig -a -t vnode -f /var/snapshot/snap -u 4 &prompt.root; mount -r /dev/md4 /mnt You can now walk the hierarchy of your frozen /var file system mounted at /mnt. Everything will be in the same state it was during the snapshot creation time. The only exception is that any earlier snapshots will appear as zero length files. When the use of a snapshot has delimited, it can be unmounted with: &prompt.root; umount /mnt &prompt.root; mdconfig -d -u 4 For more information about and file system snapshots, including technical papers, you can visit Marshall Kirk McKusick's website at . File System Quotas accounting disk space disk quotas Quotas are an optional feature of the operating system that allow you to limit the amount of disk space and/or the number of files a user or members of a group may allocate on a per-file system basis. This is used most often on timesharing systems where it is desirable to limit the amount of resources any one user or group of users may allocate. This will prevent one user or group of users from consuming all of the available disk space. Configuring Your System to Enable Disk Quotas Before attempting to use disk quotas, it is necessary to make sure that quotas are configured in your kernel. This is done by adding the following line to your kernel configuration file: options QUOTA The stock GENERIC kernel does not have this enabled by default, so you will have to configure, build and install a custom kernel in order to use disk quotas. Please refer to for more information on kernel configuration. Next you will need to enable disk quotas in /etc/rc.conf. This is done by adding the line: enable_quotas="YES" disk quotas checking For finer control over your quota startup, there is an additional configuration variable available. Normally on bootup, the quota integrity of each file system is checked by the &man.quotacheck.8; program. The &man.quotacheck.8; facility insures that the data in the quota database properly reflects the data on the file system. This is a very time consuming process that will significantly affect the time your system takes to boot. If you would like to skip this step, a variable in /etc/rc.conf is made available for the purpose: check_quotas="NO" If you are running FreeBSD prior to 3.2-RELEASE, the configuration is simpler, and consists of only one variable. Set the following in your /etc/rc.conf: check_quotas="YES" Finally you will need to edit /etc/fstab to enable disk quotas on a per-file system basis. This is where you can either enable user or group quotas or both for all of your file systems. To enable per-user quotas on a file system, add the option to the options field in the /etc/fstab entry for the file system you want to enable quotas on. For example: /dev/da1s2g /home ufs rw,userquota 1 2 Similarly, to enable group quotas, use the option instead of . To enable both user and group quotas, change the entry as follows: /dev/da1s2g /home ufs rw,userquota,groupquota 1 2 By default, the quota files are stored in the root directory of the file system with the names quota.user and quota.group for user and group quotas respectively. See &man.fstab.5; for more information. Even though the &man.fstab.5; manual page says that you can specify an alternate location for the quota files, this is not recommended because the various quota utilities do not seem to handle this properly. At this point you should reboot your system with your new kernel. /etc/rc will automatically run the appropriate commands to create the initial quota files for all of the quotas you enabled in /etc/fstab, so there is no need to manually create any zero length quota files. In the normal course of operations you should not be required to run the &man.quotacheck.8;, &man.quotaon.8;, or &man.quotaoff.8; commands manually. However, you may want to read their manual pages just to be familiar with their operation. Setting Quota Limits disk quotas limits Once you have configured your system to enable quotas, verify that they really are enabled. An easy way to do this is to run: &prompt.root; quota -v You should see a one line summary of disk usage and current quota limits for each file system that quotas are enabled on. You are now ready to start assigning quota limits with the &man.edquota.8; command. You have several options on how to enforce limits on the amount of disk space a user or group may allocate, and how many files they may create. You may limit allocations based on disk space (block quotas) or number of files (inode quotas) or a combination of both. Each of these limits are further broken down into two categories: hard and soft limits. hard limit A hard limit may not be exceeded. Once a user reaches his hard limit he may not make any further allocations on the file system in question. For example, if the user has a hard limit of 500 blocks on a file system and is currently using 490 blocks, the user can only allocate an additional 10 blocks. Attempting to allocate an additional 11 blocks will fail. soft limit Soft limits, on the other hand, can be exceeded for a limited amount of time. This period of time is known as the grace period, which is one week by default. If a user stays over his or her soft limit longer than the grace period, the soft limit will turn into a hard limit and no further allocations will be allowed. When the user drops back below the soft limit, the grace period will be reset. The following is an example of what you might see when you run the &man.edquota.8; command. When the &man.edquota.8; command is invoked, you are placed into the editor specified by the EDITOR environment variable, or in the vi editor if the EDITOR variable is not set, to allow you to edit the quota limits. &prompt.root; edquota -u test Quotas for user test: /usr: blocks in use: 65, limits (soft = 50, hard = 75) inodes in use: 7, limits (soft = 50, hard = 60) /usr/var: blocks in use: 0, limits (soft = 50, hard = 75) inodes in use: 0, limits (soft = 50, hard = 60) You will normally see two lines for each file system that has quotas enabled. One line for the block limits, and one line for inode limits. Simply change the value you want updated to modify the quota limit. For example, to raise this user's block limit from a soft limit of 50 and a hard limit of 75 to a soft limit of 500 and a hard limit of 600, change: /usr: blocks in use: 65, limits (soft = 50, hard = 75) to: /usr: blocks in use: 65, limits (soft = 500, hard = 600) The new quota limits will be in place when you exit the editor. Sometimes it is desirable to set quota limits on a range of UIDs. This can be done by use of the option on the &man.edquota.8; command. First, assign the desired quota limit to a user, and then run edquota -p protouser startuid-enduid. For example, if user test has the desired quota limits, the following command can be used to duplicate those quota limits for UIDs 10,000 through 19,999: &prompt.root; edquota -p test 10000-19999 For more information see &man.edquota.8; manual page. Checking Quota Limits and Disk Usage disk quotas checking You can use either the &man.quota.1; or the &man.repquota.8; commands to check quota limits and disk usage. The &man.quota.1; command can be used to check individual user or group quotas and disk usage. A user may only examine his own quota, and the quota of a group he is a member of. Only the super-user may view all user and group quotas. The &man.repquota.8; command can be used to get a summary of all quotas and disk usage for file systems with quotas enabled. The following is some sample output from the quota -v command for a user that has quota limits on two file systems. Disk quotas for user test (uid 1002): Filesystem blocks quota limit grace files quota limit grace /usr 65* 50 75 5days 7 50 60 /usr/var 0 50 75 0 50 60 grace period On the /usr file system in the above example, this user is currently 15 blocks over the soft limit of 50 blocks and has 5 days of the grace period left. Note the asterisk * which indicates that the user is currently over his quota limit. Normally file systems that the user is not using any disk space on will not show up in the output from the &man.quota.1; command, even if he has a quota limit assigned for that file system. The option will display those file systems, such as the /usr/var file system in the above example. Quotas over NFS NFS Quotas are enforced by the quota subsystem on the NFS server. The &man.rpc.rquotad.8; daemon makes quota information available to the &man.quota.1; command on NFS clients, allowing users on those machines to see their quota statistics. Enable rpc.rquotad in /etc/inetd.conf like so: rquotad/1 dgram rpc/udp wait root /usr/libexec/rpc.rquotad rpc.rquotad Now restart inetd: &prompt.root; kill -HUP `cat /var/run/inetd.pid` Lucky Green Contributed by
shamrock@cypherpunks.to
 Encrypting Disk Partitions disks encrypting FreeBSD offers excellent online protections against unauthorized data access. File permissions and Mandatory Access Control (MAC) (see ) help prevent unauthorized third-parties from accessing data while the operating system is active and the computer is powered up. However, the permissions enforced by the operating system are irrelevant if an attacker has physical access to a computer and can simply move the computer's hard drive to another system to copy and analyze the sensitive data. Regardless of how an attacker may have come into possession of a hard drive or powered-down computer, GEOM Based Disk Encryption (gbde) can protect the data on the computer's file systems against even highly-motivated attackers with significant resources. Unlike cumbersome encryption methods that encrypt only individual files, gbde transparently encrypts entire file systems. No cleartext ever touches the hard drive's platter. Enabling gbde in the Kernel Become <username>root</username> Configuring gbde requires super-user privileges. &prompt.user; su - Password: Verify the Operating System Version &man.gbde.4; requires FreeBSD 5.0 or higher. &prompt.root; uname -r 5.0-RELEASE Add &man.gbde.4; Support to the Kernel Configuration File Using your favorite text editor, add the following line to your kernel configuration file: options GEOM_BDE Configure, recompile, and install the FreeBSD kernel. This process is described in . Reboot into the new kernel. Preparing the Encrypted Hard Drive The following example assumes that you are adding a new hard drive to your system that will hold a single encrypted partition. This partition will be mounted as /private. gbde can also be used to encrypt /home and /var/mail, but this requires more complex instructions which exceed the scope of this introduction. Add the New Hard Drive Install the new drive to the system as explained in . For the purposes of this example, a new hard drive partition has been added as /dev/ad4s1c. The /dev/ad0s1* devices represent existing standard FreeBSD partitions on the example system. &prompt.root; ls /dev/ad* /dev/ad0 /dev/ad0s1b /dev/ad0s1e /dev/ad4s1 /dev/ad0s1 /dev/ad0s1c /dev/ad0s1f /dev/ad4s1c /dev/ad0s1a /dev/ad0s1d /dev/ad4 Create a Directory to Hold gbde Lock Files &prompt.root; mkdir /etc/gbde The gbde lock file contains information that gbde requires to access encrypted partitions. Without access to the lock file, gbde will not be able to decrypt the data contained in the encrypted partition without significant manual intervention which is not supported by the software. Each encrypted partition uses a separate lock file. Initialize the gbde Partition A gbde partition must be initialized before it can be used. This initialization needs to be performed only once: &prompt.root; gbde init /dev/ad4s1c -i -L /etc/gbde/ad4s1c &man.gbde.8; will open your editor, permitting you to set various configuration options in a template. For use with UFS1 or UFS2, set the sector_size to 2048: $FreeBSD: src/sbin/gbde/template.txt,v 1.1 2002/10/20 11:16:13 phk Exp $ # # Sector size is the smallest unit of data which can be read or written. # Making it too small decreases performance and decreases available space. # Making it too large may prevent filesystems from working. 512 is the # minimum and always safe. For UFS, use the fragment size # sector_size = 2048 [...] &man.gbde.8; will ask you twice to type the passphrase that should be used to secure the data. The passphrase must be the same both times. gbde's ability to protect your data depends entirely on the quality of the passphrase that you choose. For tips on how to select a secure passphrase that is easy to remember, see the Diceware Passphrase website. The gbde init command creates a lock file for your gbde partition that in this example is stored as /etc/gbde/ad4s1c. gbde lock files must be backed up together with the contents of any encrypted partitions. While deleting a lock file alone cannot prevent a determined attacker from decrypting a gbde partition, without the lock file, the legitimate owner will be unable to access the data on the encrypted partition without a significant amount of work that is totally unsupported by &man.gbde.8; and its designer. Attach the Encrypted Partition to the Kernel &prompt.root; gbde attach /dev/ad4s1c -l /etc/gbde/ad4s1c You will be asked to provide the passphrase that you selected during the initialization of the encrypted partition. The new encrypted device will show up in /dev as /dev/device_name.bde: &prompt.root; ls /dev/ad* /dev/ad0 /dev/ad0s1b /dev/ad0s1e /dev/ad4s1 /dev/ad0s1 /dev/ad0s1c /dev/ad0s1f /dev/ad4s1c /dev/ad0s1a /dev/ad0s1d /dev/ad4 /dev/ad4s1c.bde Create a File System on the Encrypted Device Once the encrypted device has been attached to the kernel, you can create a file system on the device. To create a file system on the encrypted device, use &man.newfs.8;. Since it is much faster to initialize a new UFS2 file system than it is to initialize the old UFS1 file system, using &man.newfs.8; with the option is recommended. The option is the default with &os; 5.1-RELEASE and later. &prompt.root; newfs -U -O2 /dev/ad4s1c.bde The &man.newfs.8; command must be performed on an attached gbde partition which is identified by a *.bde extension to the device name. Mount the Encrypted Partition Create a mount point for the encrypted file system. &prompt.root; mkdir /private Mount the encrypted file system. &prompt.root; mount /dev/ad4s1c.bde /private Verify That the Encrypted File System is Available The encrypted file system should now be visible to &man.df.1; and be available for use. &prompt.user; df -H Filesystem Size Used Avail Capacity Mounted on /dev/ad0s1a 1037M 72M 883M 8% / /devfs 1.0K 1.0K 0B 100% /dev /dev/ad0s1f 8.1G 55K 7.5G 0% /home /dev/ad0s1e 1037M 1.1M 953M 0% /tmp /dev/ad0s1d 6.1G 1.9G 3.7G 35% /usr /dev/ad4s1c.bde 150G 4.1K 138G 0% /private Mounting Existing Encrypted File Systems After each boot, any encrypted file systems must be re-attached to the kernel, checked for errors, and mounted, before the file systems can be used. The required commands must be executed as user root. Attach the gbde Partition to the Kernel &prompt.root; gbde attach /dev/ad4s1c -l /etc/gbde/ad4s1c You will be asked to provide the passphrase that you selected during initialization of the encrypted gbde partition. Check the File System for Errors Since encrypted file systems cannot yet be listed in /etc/fstab for automatic mounting, the file systems must be checked for errors by running &man.fsck.8; manually before mounting. &prompt.root; fsck -p -t ffs /dev/ad4s1c.bde Mount the Encrypted File System &prompt.root; mount /dev/ad4s1c.bde /private The encrypted file system is now available for use. Automatically Mounting Encrypted Partitions It is possible to create a script to automatically attach, check, and mount an encrypted partition, but for security reasons the script should not contain the &man.gbde.8; password. Instead, it is recommended that such scripts be run manually while providing the password via the console or &man.ssh.1;. Cryptographic Protections Employed by gbde &man.gbde.8; encrypts the sector payload using 128-bit AES in CBC mode. Each sector on the disk is encrypted with a different AES key. For more information on gbde's cryptographic design, including how the sector keys are derived from the user-supplied passphrase, see &man.gbde.4;. Compatibility Issues &man.sysinstall.8; is incompatible with gbde-encrypted devices. All *.bde devices must be detached from the kernel before starting &man.sysinstall.8; or it will crash during its initial probing for devices. To detach the encrypted device used in our example, use the following command: &prompt.root; gbde detach /dev/ad4s1c Also note that, as &man.vinum.4; does not use the &man.geom.4; subsystem, you cannot use gbde with vinum volumes. diff --git a/en_US.ISO8859-1/books/handbook/install/chapter.sgml b/en_US.ISO8859-1/books/handbook/install/chapter.sgml index f5440a20d4..a6063ccafc 100644 --- a/en_US.ISO8859-1/books/handbook/install/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/install/chapter.sgml @@ -1,5573 +1,5573 @@ Jim Mock Restructured, reorganized, and parts rewritten by Randy Pratt The sysinstall walkthrough, screenshots, and general copy by Installing FreeBSD Synopsis installation FreeBSD is provided with a text-based, easy to use installation program called sysinstall. This is the default installation program for FreeBSD, although vendors are free to provide their own installation suite if they wish. This chapter describes how to use sysinstall to install FreeBSD. After reading this chapter, you will know: How to create the FreeBSD installation disks. How FreeBSD refers to, and subdivides, your hard disks. How to start sysinstall. The questions sysinstall will ask you, what they mean, and how to answer them. Before reading this chapter, you should: Read the supported hardware list that shipped with the version of FreeBSD you are installing, and verify that your hardware is supported. In general, these installation instructions are written for &i386; (PC compatible) architecture computers. Where applicable, instructions specific to other platforms (for example, Alpha) will be listed. Although this guide is kept as up to date as possible, you may find minor differences between the installer and what is shown here. It is suggested that you use this chapter as a general guide rather than a literal installation manual. Pre-installation Tasks Inventory Your Computer Before installing FreeBSD you should attempt to inventory the components in your computer. The FreeBSD installation routines will show you the components (hard disks, network cards, CDROM drives, and so forth) with their model number and manufacturer. FreeBSD will also attempt to determine the correct configuration for these devices, which includes information about IRQ and IO port usage. Due to the vagaries of PC hardware this process is not always completely successful, and you may need to correct FreeBSD's determination of your configuration. If you already have another operating system installed, such as &windows; or Linux, it is a good idea to use the facilities provided by those operating systems to see how your hardware is already configured. If you are not sure what settings an expansion card is using, you may find it printed on the card itself. Popular IRQ numbers are 3, 5, and 7, and IO port addresses are normally written as hexadecimal numbers, such as 0x330. We recommend you print or write down this information before installing FreeBSD. It may help to use a table, like this: Sample Device Inventory Device Name IRQ IO port(s) Notes First hard disk N/A N/A 40 GB, made by Seagate, first IDE master CDROM N/A N/A First IDE slave Second hard disk N/A N/A 20 GB, made by IBM, second IDE master First IDE controller 14 0x1f0 Network card N/A N/A &intel; 10/100 Modem N/A N/A &tm.3com; 56K faxmodem, on COM1 …
Backup Your Data If the computer you will be installing FreeBSD on contains valuable data, then ensure you have it backed up, and that you have tested the backups before installing FreeBSD. The FreeBSD installation routine will prompt you before writing any data to your disk, but once that process has started it cannot be undone. Decide Where to Install FreeBSD If you want FreeBSD to use your entire hard disk, then there is nothing more to concern yourself with at this point — you can skip this section. However, if you need FreeBSD to co-exist with other operating systems then you need to have a rough understanding of how data is laid out on the disk, and how this affects you. Disk Layouts for the &i386; A PC disk can be divided into discrete chunks. These chunks are called partitions. By design, the PC only supports four partitions per disk. These partitions are called primary partitions. To work around this limitation and allow more than four partitions, a new partition type was created, the extended partition. A disk may contain only one extended partition. Special partitions, called logical partitions, can be created inside this extended partition. Each partition has a partition ID, which is a number used to identify the type of data on the partition. FreeBSD partitions have the partition ID of 165. In general, each operating system that you use will identify partitions in a particular way. For example, DOS, and its descendants, like &windows;, assign each primary and logical partition a drive letter, starting with C:. FreeBSD must be installed into a primary partition. FreeBSD can keep all its data, including any files that you create, on this one partition. However, if you have multiple disks, then you can create a FreeBSD partition on all, or some, of them. When you install FreeBSD, you must have one partition available. This might be a blank partition that you have prepared, or it might be an existing partition that contains data that you no longer care about. If you are already using all the partitions on all your disks, then you will have to free one of them for FreeBSD using the tools provided by the other operating systems you use (e.g., fdisk on DOS or &windows;). If you have a spare partition then you can use that. However, you may need to shrink one or more of your existing partitions first. A minimal installation of FreeBSD takes as little as 100 MB of disk space. However, that is a very minimal install, leaving almost no space for your own files. A more realistic minimum is 250 MB without a graphical environment, and 350 MB or more if you want a graphical user interface. If you intend to install a lot of third party software as well, then you will need more space. You can use a commercial tool such as &partitionmagic; to resize your partitions to make space for FreeBSD. The tools directory on the CDROM contains two free software tools which can carry out this task, namely FIPS and PResizer. Documentation for both of these is available in the same directory. FIPS, PResizer, and &partitionmagic; can resize FAT16 and FAT32 partitions — used in &ms-dos; through &windows; ME. &partitionmagic; is the only known application that can resize NTFS. Incorrect use of these tools can delete the data on your disk. Be sure that you have recent, working backups before using them. Using an Existing Partition Unchanged Suppose that you have a computer with a single 4 GB disk that already has a version of &windows; installed, and you have split the disk into two drive letters, C: and D:, each of which is 2 GB in size. You have 1 GB of data on C:, and 0.5 GB of data on D:. This means that your disk has two partitions on it, one per drive letter. You can copy all your existing data from D: to C:, which will free up the second partition, ready for FreeBSD. Shrinking an Existing Partition Suppose that you have a computer with a single 4 GB disk that already has a version of &windows; installed. When you installed &windows; you created one large partition, giving you a C: drive that is 4 GB in size. You are currently using 1.5 GB of space, and want FreeBSD to have 2 GB of space. In order to install FreeBSD you will need to either: Backup your &windows; data, and then reinstall &windows;, asking for a 2 GB partition at install time. Use one of the tools such as &partitionmagic;, described above, to shrink your &windows; partition. Disk Layouts for the Alpha Alpha You will need a dedicated disk for FreeBSD on the Alpha. It is not possible to share a disk with another operating system at this time. Depending on the specific Alpha machine you have, this disk can either be a SCSI disk or an IDE disk, as long as your machine is capable of booting from it. Following the conventions of the Digital / Compaq manuals all SRM input is shown in uppercase. SRM is case insensitive. To find the names and types of disks in your machine, use the SHOW DEVICE command from the SRM console prompt: >>>SHOW DEVICE dka0.0.0.4.0 DKA0 TOSHIBA CD-ROM XM-57 3476 dkc0.0.0.1009.0 DKC0 RZ1BB-BS 0658 dkc100.1.0.1009.0 DKC100 SEAGATE ST34501W 0015 dva0.0.0.0.1 DVA0 ewa0.0.0.3.0 EWA0 00-00-F8-75-6D-01 pkc0.7.0.1009.0 PKC0 SCSI Bus ID 7 5.27 pqa0.0.0.4.0 PQA0 PCI EIDE pqb0.0.1.4.0 PQB0 PCI EIDE This example is from a Digital Personal Workstation 433au and shows three disks attached to the machine. The first is a CDROM drive called DKA0 and the other two are disks and are called DKC0 and DKC100 respectively. Disks with names of the form DKx are SCSI disks. For example DKA100 refers to a SCSI disk with SCSI target ID 1 on the first SCSI bus (A), whereas DKC300 refers to a SCSI disk with SCSI ID 3 on the third SCSI bus (C). Devicename PKx refers to the SCSI host bus adapter. As seen in the SHOW DEVICE output SCSI CDROM drives are treated as any other SCSI hard disk drive. IDE disks have names similar to DQx, while PQx is the associated IDE controller. Collect Your Network Configuration Details If you intend to connect to a network as part of your FreeBSD installation (for example, if you will be installing from an FTP site or an NFS server), then you need to know your network configuration. You will be prompted for this information during the installation so that FreeBSD can connect to the network to complete the install. Connecting to an Ethernet Network or Cable/DSL Modem If you connect to an Ethernet network, or you have an Internet connection using an Ethernet adapter via cable or DSL, then you will need the following information: IP address IP address of the default gateway Hostname DNS server IP addresses Subnet Mask If you do not know this information, then ask your system administrator or service provider. They may say that this information is assigned automatically, using DHCP. If so, make a note of this. Connecting Using a Modem If you dial up to an ISP using a regular modem then you can still install FreeBSD over the Internet, it will just take a very long time. You will need to know: The phone number to dial for your ISP The COM: port your modem is connected to The username and password for your ISP account Check for FreeBSD Errata Although the FreeBSD project strives to ensure that each release of FreeBSD is as stable as possible, bugs do occasionally creep into the process. On very rare occasions those bugs affect the installation process. As these problems are discovered and fixed, they are noted in the FreeBSD Errata, which is found on the FreeBSD web site. You should check the errata before installing to make sure that there are no late-breaking problems which you should be aware of. Information about all the releases, including the errata for each release, can be found on the release information section of the FreeBSD web site. Obtain the FreeBSD Installation Files The FreeBSD installation process can install FreeBSD from files located in any of the following places: Local Media A CDROM or DVD A DOS partition on the same computer A SCSI or QIC tape Floppy disks Network An FTP site, going through a firewall, or using an HTTP proxy, as necessary An NFS server A dedicated parallel or serial connection If you have purchased FreeBSD on CD or DVD then you already have everything you need, and should proceed to the next section (). If you have not obtained the FreeBSD installation files you should skip ahead to which explains how to prepare to install FreeBSD from any of the above. After reading that section, you should come back here, and read on to . Prepare the Boot Media The FreeBSD installation process is started by booting your computer into the FreeBSD installer—it is not a program you run within another operating system. Your computer normally boots using the operating system installed on your hard disk, but it can also be configured to use a bootable floppy disk. Most modern computers can also boot from a CDROM in the CDROM drive. If you have FreeBSD on CDROM or DVD (either one you purchased or you prepared yourself), and your computer allows you to boot from the CDROM or DVD (typically a BIOS option called Boot Order or similar), then you can skip this section. The FreeBSD CDROM and DVD images are bootable and can be used to install FreeBSD without any other special preparation. To create boot floppy images, follow these steps: Acquire the Boot Floppy Images The boot disks are available on your installation media in the floppies/ directory, and can also be downloaded from the floppies directory, ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/<arch>/<version>-RELEASE/floppies/. Replace <arch> and <version> with the architecture and the version number which you want to install, respectively. For example, the boot floppy images for &os; &rel.current;-RELEASE for &i386; are available from . The floppy images have a .flp extension. The floppies/ directory contains a number of different images, and the ones you will need to use depends on the version of FreeBSD you are installing, and in some cases, the hardware you are installing to. If you are installing FreeBSD 4.x in most cases you will just need two files, kern.flp and mfsroot.flp. If you are installing FreeBSD 5.x in most cases you will need three floppies, boot.flp, kern1.flp, and kern2.flp. Additional device drivers may be necessary for some systems. These drivers are provided on the drivers.flp image. Check README.TXT in the same directory for the most up to date information about these floppy images. Your FTP program must use binary mode to download these disk images. Some web browsers have been known to use text (or ASCII) mode, which will be apparent if you cannot boot from the disks. Prepare the Floppy Disks You must prepare one floppy disk per image file you had to download. It is imperative that these disks are free from defects. The easiest way to test this is to format the disks for yourself. Do not trust pre-formatted floppies. The format utility in &windows; will not tell about the presence of bad blocks, it simply marks them as bad and ignores them. It is advised that you use brand new floppies if choosing this installation route. If you try to install FreeBSD and the installation program crashes, freezes, or otherwise misbehaves, one of the first things to suspect is the floppies. Try writing the floppy image files to new disks and try again. Write the Image Files to the Floppy Disks The .flp files are not regular files you copy to the disk. They are images of the complete contents of the disk. This means that you cannot simply copy files from one disk to another. Instead, you must use specific tools to write the images directly to the disk. DOS If you are creating the floppies on a computer running &ms-dos;/&windows;, then we provide a tool to do this called fdimage. If you are using the floppies from the CDROM, and your CDROM is the E: drive, then you would run this: E:\> tools\fdimage floppies\kern.flp A: Repeat this command for each .flp file, replacing the floppy disk each time, being sure to label the disks with the name of the file that you copied to them. Adjust the command line as necessary, depending on where you have placed the .flp files. If you do not have the CDROM, then fdimage can be downloaded from the tools directory on the FreeBSD FTP site. If you are writing the floppies on a &unix; system (such as another FreeBSD system) you can use the &man.dd.1; command to write the image files directly to disk. On FreeBSD, you would run: &prompt.root; dd if=kern.flp of=/dev/fd0 On FreeBSD, /dev/fd0 refers to the first floppy disk (the A: drive). /dev/fd1 would be the B: drive, and so on. Other &unix; variants might have different names for the floppy disk devices, and you will need to check the documentation for the system as necessary. You are now ready to start installing FreeBSD. Starting the Installation By default, the installation will not make any changes to your disk(s) until you see the following message: Last Chance: Are you SURE you want continue the installation? If you're running this on a disk with data you wish to save then WE STRONGLY ENCOURAGE YOU TO MAKE PROPER BACKUPS before proceeding! We can take no responsibility for lost disk contents! The install can be exited at any time prior to the final warning without changing the contents of the hard drive. If you are concerned that you have configured something incorrectly you can just turn the computer off before this point, and no damage will be done. Booting Booting for the &i386; Start with your computer turned off. Turn on the computer. As it starts it should display an option to enter the system set up menu, or BIOS, commonly reached by keys like F2, F10, Del, or Alt S . Use whichever keystroke is indicated on screen. In some cases your computer may display a graphic while it starts. Typically, pressing Esc will dismiss the graphic and allow you to see the necessary messages. Find the setting that controls which devices the system boots from. This is usually labeled as the Boot Order and commonly shown as a list of devices, such as Floppy, CDROM, First Hard Disk, and so on. If you needed to prepare boot floppies, then make sure that the floppy disk is selected. If you are booting from the CDROM then make sure that that is selected instead. In case of doubt, you should consult the manual that came with your computer, and/or its motherboard. Make the change, then save and exit. The computer should now restart. If you needed to prepare boot floppies, as described in , then one of them will be the first boot disc, probably the one containing kern.flp. Put this disc in your floppy drive. If you are booting from CDROM, then you will need to turn on the computer, and insert the CDROM at the first opportunity. If your computer starts up as normal and loads your existing operating system, then either: The disks were not inserted early enough in the boot process. Leave them in, and try restarting your computer. The BIOS changes earlier did not work correctly. You should redo that step until you get the right option. Your particular BIOS does not support booting from the desired media. FreeBSD will start to boot. If you are booting from CDROM you will see a display similar to this (version information omitted): Verifying DMI Pool Data ........ Boot from ATAPI CD-ROM : 1. FD 2.88MB System Type-(00) Uncompressing ... done BTX loader 1.00 BTX version is 1.01 Console: internal video/keyboard BIOS drive A: is disk0 BIOS drive B: is disk1 BIOS drive C: is disk2 BIOS drive D: is disk3 BIOS 639kB/261120kB available memory FreeBSD/i386 bootstrap loader, Revision 0.8 /kernel text=0x277391 data=0x3268c+0x332a8 | | Hit [Enter] to boot immediately, or any other key for command prompt. Booting [kernel] in 9 seconds... _ If you are booting from floppy disc, you will see a display similar to this (version information omitted): Verifying DMI Pool Data ........ BTX loader 1.00 BTX version is 1.01 Console: internal video/keyboard BIOS drive A: is disk0 BIOS drive C: is disk1 BIOS 639kB/261120kB available memory FreeBSD/i386 bootstrap loader, Revision 0.8 /kernel text=0x277391 data=0x3268c+0x332a8 | Please insert MFS root floppy and press enter: Follow these instructions by removing the kern.flp disc, insert the mfsroot.flp disc, and press Enter. Whether you booted from floppy or CDROM, the boot process will then get to this point: Hit [Enter] to boot immediately, or any other key for command prompt. Booting [kernel] in 9 seconds... _ Either wait ten seconds, or press Enter. This will then launch the kernel configuration menu. Booting for the Alpha Alpha Start with your computer turned off. Turn on the computer and wait for a boot monitor prompt. If you needed to prepare boot floppies, as described in then one of them will be the first boot disc, probably the one containing kern.flp. Put this disc in your floppy drive and type the following command to boot the disk (substituting the name of your floppy drive if necessary): >>>BOOT DVA0 -FLAGS '' -FILE '' If you are booting from CDROM, insert the CDROM into the drive and type the following command to start the installation (substituting the name of the appropriate CDROM drive if necessary): >>>BOOT DKA0 -FLAGS '' -FILE '' FreeBSD will start to boot. If you are booting from a floppy disc, at some point you will see the message: Please insert MFS root floppy and press enter: Follow these instructions by removing the kern.flp disc, insert the mfsroot.flp disc, and press Enter. Whether you booted from floppy or CDROM, the boot process will then get to this point: Hit [Enter] to boot immediately, or any other key for command prompt. Booting [kernel] in 9 seconds... _ Either wait ten seconds, or press Enter. This will then launch the kernel configuration menu. Kernel Configuration From FreeBSD versions 5.0 and later, userconfig has been deprecated in favor of the new &man.device.hints.5; method. For more information on &man.device.hints.5; please visit The kernel is the core of the operating system. It is responsible for many things, including access to all the devices you may have on your system, such as hard disks, network cards, sound cards, and so on. Each piece of hardware supported by the FreeBSD kernel has a driver associated with it. Each driver has a two or three letter name, such as sa for the SCSI sequential access driver, or sio for the Serial I/O driver (which manages COM ports). When the kernel starts, each driver checks the system to see whether or not the hardware it supports exists on your system. If it does, then the driver configures the hardware and makes it available to the rest of the kernel. This checking is commonly referred to as device probing. Unfortunately, it is not always possible to do this in a safe way. Some hardware drivers do not co-exist well, and probing for one piece of hardware can sometimes leave another in an inconsistent state. This is a basic limitation of the PC design. Many older devices are called ISA devices—as opposed to PCI devices. The ISA specification requires each device to have some information hard coded into it, typically the Interrupt Request Line number (IRQ) and IO port address that the driver uses. This information is commonly set by using physical jumpers on the card, or by using a DOS based utility. This was often a source of problems, because it was not possible to have two devices that shared the same IRQ or port address. Newer devices follow the PCI specification, which does not require this, as the devices are supposed to cooperate with the BIOS, and are told which IRQ and IO port addresses to use. If you have any ISA devices in your computer then FreeBSD's driver for that device will need to be configured with the IRQ and port address that you have set the card to. This is why carrying out an inventory of your hardware (see ) can be useful. Unfortunately, the default IRQs and memory ports used by some drivers clash. This is because some ISA devices are shipped with IRQs or memory ports that clash. The defaults in FreeBSD's drivers are deliberately set to mirror the manufacturer's defaults, so that, out of the box, as many devices as possible will work. This is almost never an issue when running FreeBSD day-to-day. Your computer will not normally contain two pieces of hardware that clash, because one of them would not work (irrespective of the operating system you are using). It becomes an issue when you are installing FreeBSD for the first time because the kernel used to carry out the install has to contain as many drivers as possible, so that many different hardware configurations can be supported. This means that some of those drivers will have conflicting configurations. The devices are probed in a strict order, and if you own a device that is probed late in the process, but conflicted with an earlier probe, then your hardware might not function or be probed correctly when you install FreeBSD. Because of this, the first thing you have the opportunity to do when installing FreeBSD is look at the list of drivers that are configured into the kernel, and either disable some of them, if you do not own that device, or confirm (and alter) the driver's configuration if you do own the device but the defaults are wrong. This probably sounds much more complicated than it actually is. shows the first kernel configuration menu. We recommend that you choose the Start kernel configuration in full-screen visual mode option, as it presents the easiest interface for the new user.
Kernel Configuration Menu &txt.install.userconfig;
The kernel configuration screen () is then divided into four sections: A collapsible list of all the drivers that are currently marked as active, subdivided into groups such as Storage, and Network. Each driver is shown as a description, its two or three letter driver name, and the IRQ and memory port used by that driver. In addition, if an active driver conflicts with another active driver then CONF is shown next to the driver name. This section also shows the total number of conflicting drivers that are currently active. Drivers that have been marked inactive. They remain in the kernel, but they will not probe for their device when the kernel starts. These are subdivided into groups in the same way as the active driver list. More detail about the currently selected driver, including its IRQ and memory port address. Information about the keystrokes that are valid at this point in time.
The Kernel Device Configuration Visual Interface &txt.install.userconfig2;
Do not worry if any conflicts are listed, it is to be expected; all the drivers are enabled, and as has already been explained, some of them will conflict with one another. You now have to work through the list of drivers, resolving the conflicts. Resolving Driver Conflicts Press X. This will completely expand the list of drivers, so you can see all of them. You will need to use the arrow keys to scroll back and forth through the active driver list. shows the result of pressing X.
Expanded Driver List
Disable all the drivers for devices that you do not have. To disable a driver, highlight it with the arrow keys and press Del. The driver will be moved to the Inactive Drivers list. If you inadvertently disable a device that you need then press Tab to switch to the Inactive Drivers list, select the driver that you disabled, and press Enter to move it back to the active list. Do not disable sc0. This controls the screen, and you will need this unless you are installing over a serial cable. Only disable atkbd0 if you are using a USB keyboard. If you have a normal keyboard then you must keep atkbd0. If there are no conflicts listed then you can skip this step. Otherwise, the remaining conflicts need to be examined. If they do not have the indication of an allowed conflict in the message area, then either the IRQ/address for device probe will need to be changed, or the IRQ/address on the hardware will need to be changed. To change the driver's configuration for IRQ and IO port address, select the device and press Enter. The cursor will move to the third section of the screen, and you can change the values. You should enter the values for IRQ and port address that you discovered when you made your hardware inventory. Press Q to finish editing the device's configuration and return to the active driver list. If you are not sure what these figures should be then you can try using -1. Some FreeBSD drivers can safely probe the hardware to discover what the correct value should be, and a value of -1 configures them to do this. The procedure for changing the address on the hardware varies from device to device. For some devices you may need to physically remove the card from your computer and adjust jumper settings or DIP switches. Other cards may have come with a DOS floppy that contains the programs used to reconfigure the card. In any case, you should refer to the documentation that came with the device. This will obviously entail restarting your computer, so you will need to boot back into the FreeBSD installation routine when you have reconfigured the card. When all the conflicts have been resolved the screen will look similar to .
Driver Configuration With No Conflicts
As you can see, the active driver list is now much smaller, with only drivers for the hardware that actually exists being listed. You can now save these changes, and move on to the next step of the install. Press Q to quit the device configuration interface. This message will appear: Save these parameters before exiting? ([Y]es/[N]o/[C]ancel) Answer Y to save the parameters to memory (it will be saved to disk if you finish the install) and the probing will start. After displaying the probe results in white on black text sysinstall will start and display its main menu ().
Sysinstall Main Menu
Reviewing the Device Probe Results The last few hundred lines that have been displayed on screen are stored and can be reviewed. To review the buffer, press Scroll Lock. This turns on scrolling in the display. You can then use the arrow keys, or PageUp and PageDown to view the results. Press Scroll Lock again to stop scrolling. Do this now, to review the text that scrolled off the screen when the kernel was carrying out the device probes. You will see text similar to , although the precise text will differ depending on the devices that you have in your computer.
Typical Device Probe Results avail memory = 253050880 (247120K bytes) Preloaded elf kernel "kernel" at 0xc0817000. Preloaded mfs_root "/mfsroot" at 0xc0817084. md0: Preloaded image </mfsroot> 4423680 bytes at 0xc03ddcd4 md1: Malloc disk Using $PIR table, 4 entries at 0xc00fde60 npx0: <math processor> on motherboard npx0: INT 16 interface pcib0: <Host to PCI bridge> on motherboard pci0: <PCI bus> on pcib0 pcib1:<VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 on pci0 pci1: <PCI bus> on pcib1 pci1: <Matrox MGA G200 AGP graphics accelerator> at 0.0 irq 11 isab0: <VIA 82C586 PCI-ISA bridge> at device 7.0 on pci0 isa0: <iSA bus> on isab0 atapci0: <VIA 82C586 ATA33 controller> port 0xe000-0xe00f at device 7.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 uhci0 <VIA 83C572 USB controller> port 0xe400-0xe41f irq 10 at device 7.2 on pci 0 usb0: <VIA 83572 USB controller> on uhci0 usb0: USB revision 1.0 uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr1 uhub0: 2 ports with 2 removable, self powered pci0: <unknown card> (vendor=0x1106, dev=0x3040) at 7.3 dc0: <ADMtek AN985 10/100BaseTX> port 0xe800-0xe8ff mem 0xdb000000-0xeb0003ff ir q 11 at device 8.0 on pci0 dc0: Ethernet address: 00:04:5a:74:6b:b5 miibus0: <MII bus> on dc0 ukphy0: <Generic IEEE 802.3u media interface> on miibus0 ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto ed0: <NE2000 PCI Ethernet (RealTek 8029)> port 0xec00-0xec1f irq 9 at device 10. 0 on pci0 ed0 address 52:54:05:de:73:1b, type NE2000 (16 bit) isa0: too many dependant configs (8) isa0: unexpected small tag 14 orm0: <Option ROM> at iomem 0xc0000-0xc7fff on isa0 fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: <1440-KB 3.5" drive> on fdc0 drive 0 atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0 atkbd0: <AT Keyboard> flags 0x1 irq1 on atkbdc0 kbd0 at atkbd0 psm0: <PS/2 Mouse> irq 12 on atkbdc0 psm0: model Generic PS/@ mouse, device ID 0 vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0 sc0: <System console> at flags 0x100 on isa0 sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 pppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/15 bytes threshold plip0: <PLIP network interface> on ppbus0 ad0: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata0-master UDMA33 acd0: CD-RW <LITE-ON LTR-1210B> at ata1-slave PIO4 Mounting root from ufs:/dev/md0c /stand/sysinstall running as init on vty0
Check the probe results carefully to make sure that FreeBSD found all the devices you expected. If a device was not found, then it will not be listed. If the device's driver required configuring with the IRQ and port address then you should check that you entered them correctly. If you need to make changes to the UserConfig device probing, it is easy to exit the sysinstall program and start over again. It is also a good way to become more familiar with the process.
Select Sysinstall Exit
Use the arrow keys to select Exit Install from the Main Install Screen menu. The following message will display: User Confirmation Requested Are you sure you wish to exit? The system will reboot (be sure to remove any floppies from the drives). [ Yes ] No The install program will start again if the CDROM is left in the drive and &gui.yes; is selected. If you are booting from floppies it will be necessary to remove the mfsroot.flp floppy and replace it with kern.flp before rebooting. Introducing Sysinstall The sysinstall utility is the installation application provided by the FreeBSD Project. It is console based and is divided into a number of menus and screens that you can use to configure and control the installation process. The sysinstall menu system is controlled by the arrow keys, Enter, Space, and other keys. A detailed description of these keys and what they do is contained in sysinstall's usage information. To review this information, ensure that the Usage entry is highlighted and that the [Select] button is selected, as shown in , then press Enter. The instructions for using the menu system will be displayed. After reviewing them, press Enter to return to the Main Menu.
Selecting Usage from Sysinstall Main Menu
Selecting the Documentation Menu From the Main Menu, select Doc with the arrow keys and press Enter.
Selecting Documentation Menu
This will display the Documentation Menu.
Sysinstall Documentation Menu
It is important to read the documents provided. To view a document, select it with the arrow keys and press Enter. When finished reading a document, pressing Enter will return to the Documentation Menu. To return to the Main Installation Menu, select Exit with the arrow keys and press Enter. Selecting the Keymap Menu To change the keyboard mapping, use the arrow keys to select Keymap from the menu and press Enter. This is only required if you are using a non-standard or non-US keyboard.
Sysinstall Main Menu
A different keyboard mapping may be chosen by selecting the menu item using up/down arrow keys and pressing Space. Pressing Space again will unselect the item. When finished, choose the &gui.ok; using the arrow keys and press Enter. Only a partial list is shown in this screen representation. Selecting &gui.cancel; by pressing Tab will use the default keymap and return to the Main Install Menu.
Sysinstall Keymap Menu
Installation Options Screen Select Options and press Enter.
Sysinstall Main Menu
Sysinstall Options
The default values are usually fine for most users and do not need to be changed. The release name will vary according to the version being installed. The description of the selected item will appear at the bottom of the screen highlighted in blue. Notice that one of the options is Use Defaults to reset all values to startup defaults. Press F1 to read the help screen about the various options. Pressing Q will return to the Main Install menu. Begin a Standard Installation The Standard installation is the option recommended for those new to &unix; or FreeBSD. Use the arrow keys to select Standard and then press Enter to start the installation.
Begin Standard Installation
Allocating Disk Space Your first task is to allocate disk space for FreeBSD, and label that space so that sysinstall can prepare it. In order to do this you need to know how FreeBSD expects to find information on the disk. BIOS Drive Numbering Before you install and configure FreeBSD on your system, there is an important subject that you should be aware of, especially if you have multiple hard drives. DOS Microsoft Windows In a PC running a BIOS-dependent operating system such as &ms-dos; or µsoft.windows;, the BIOS is able to abstract the normal disk drive order, and the operating system goes along with the change. This allows the user to boot from a disk drive other than the so-called primary master. This is especially convenient for some users who have found that the simplest and cheapest way to keep a system backup is to buy an identical second hard drive, and perform routine copies of the first drive to the second drive using Ghost or XCOPY . Then, if the first drive fails, or is attacked by a virus, or is scribbled upon by an operating system defect, he can easily recover by instructing the BIOS to logically swap the drives. It is like switching the cables on the drives, but without having to open the case. SCSI BIOS More expensive systems with SCSI controllers often include BIOS extensions which allow the SCSI drives to be re-ordered in a similar fashion for up to seven drives. A user who is accustomed to taking advantage of these features may become surprised when the results with FreeBSD are not as expected. FreeBSD does not use the BIOS, and does not know the logical BIOS drive mapping. This can lead to very perplexing situations, especially when drives are physically identical in geometry, and have also been made as data clones of one another. When using FreeBSD, always restore the BIOS to natural drive numbering before installing FreeBSD, and then leave it that way. If you need to switch drives around, then do so, but do it the hard way, and open the case and move the jumpers and cables. An Illustration from the Files of Bill and Fred's Exceptional Adventures: Bill breaks-down an older Wintel box to make another FreeBSD box for Fred. Bill installs a single SCSI drive as SCSI unit zero and installs FreeBSD on it. Fred begins using the system, but after several days notices that the older SCSI drive is reporting numerous soft errors and reports this fact to Bill. After several more days, Bill decides it is time to address the situation, so he grabs an identical SCSI drive from the disk drive archive in the back room. An initial surface scan indicates that this drive is functioning well, so Bill installs this drive as SCSI unit four and makes an image copy from drive zero to drive four. Now that the new drive is installed and functioning nicely, Bill decides that it is a good idea to start using it, so he uses features in the SCSI BIOS to re-order the disk drives so that the system boots from SCSI unit four. FreeBSD boots and runs just fine. Fred continues his work for several days, and soon Bill and Fred decide that it is time for a new adventure — time to upgrade to a newer version of FreeBSD. Bill removes SCSI unit zero because it was a bit flaky and replaces it with another identical disk drive from the archive. Bill then installs the new version of FreeBSD onto the new SCSI unit zero using Fred's magic Internet FTP floppies. The installation goes well. Fred uses the new version of FreeBSD for a few days, and certifies that it is good enough for use in the engineering department. It is time to copy all of his work from the old version. So Fred mounts SCSI unit four (the latest copy of the older FreeBSD version). Fred is dismayed to find that none of his precious work is present on SCSI unit four. Where did the data go? When Bill made an image copy of the original SCSI unit zero onto SCSI unit four, unit four became the new clone. When Bill re-ordered the SCSI BIOS so that he could boot from SCSI unit four, he was only fooling himself. FreeBSD was still running on SCSI unit zero. Making this kind of BIOS change will cause some or all of the Boot and Loader code to be fetched from the selected BIOS drive, but when the FreeBSD kernel drivers take-over, the BIOS drive numbering will be ignored, and FreeBSD will transition back to normal drive numbering. In the illustration at hand, the system continued to operate on the original SCSI unit zero, and all of Fred's data was there, not on SCSI unit four. The fact that the system appeared to be running on SCSI unit four was simply an artifact of human expectations. We are delighted to mention that no data bytes were killed or harmed in any way by our discovery of this phenomenon. The older SCSI unit zero was retrieved from the bone pile, and all of Fred's work was returned to him, (and now Bill knows that he can count as high as zero). Although SCSI drives were used in this illustration, the concepts apply equally to IDE drives. Creating Slices Using FDisk No changes you make at this point will be written to the disk. If you think you have made a mistake and want to start again you can use the menus to exit sysinstall and try again or press U to use the Undo option. If you get confused and can not see how to exit you can always turn your computer off. After choosing to begin a standard installation in sysinstall you will be shown this message: Message In the next menu, you will need to set up a DOS-style ("fdisk") partitioning scheme for your hard disk. If you simply wish to devote all disk space to FreeBSD (overwriting anything else that might be on the disk(s) selected) then use the (A)ll command to select the default partitioning scheme followed by a (Q)uit. If you wish to allocate only free space to FreeBSD, move to a partition marked "unused" and use the (C)reate command. [ OK ] [ Press enter or space ] Press Enter as instructed. You will then be shown a list of all the hard drives that the kernel found when it carried out the device probes. shows an example from a system with two IDE disks. They have been called ad0 and ad2.
Select Drive for FDisk
You might be wondering why ad1 is not listed here. Why has it been missed? Consider what would happen if you had two IDE hard disks, one as the master on the first IDE controller, and one as the master on the second IDE controller. If FreeBSD numbered these as it found them, as ad0 and ad1 then everything would work. But if you then added a third disk, as the slave device on the first IDE controller, it would now be ad1, and the previous ad1 would become ad2. Because device names (such as ad1s1a) are used to find filesystems, you may suddenly discover that some of your filesystems no longer appear correctly, and you would need to change your FreeBSD configuration. To work around this, the kernel can be configured to name IDE disks based on where they are, and not the order in which they were found. With this scheme the master disk on the second IDE controller will always be ad2, even if there are no ad0 or ad1 devices. This configuration is the default for the FreeBSD kernel, which is why this display shows ad0 and ad2. The machine on which this screenshot was taken had IDE disks on both master channels of the IDE controllers, and no disks on the slave channels. You should select the disk on which you want to install FreeBSD, and then press &gui.ok;. FDisk will start, with a display similar to that shown in . The FDisk display is broken into three sections. The first section, covering the first two lines of the display, shows details about the currently selected disk, including its FreeBSD name, the disk geometry, and the total size of the disk. The second section shows the slices that are currently on the disk, where they start and end, how large they are, the name FreeBSD gives them, and their description and sub-type. This example shows two small unused slices, which are artifacts of disk layout schemes on the PC. It also shows one large FAT slice, which almost certainly appears as C: in &ms-dos; / &windows;, and an extended slice, which may contain other drive letters for &ms-dos; / &windows;. The third section shows the commands that are available in FDisk.
Typical Fdisk Partitions before Editing
What you do now will depend on how you want to slice up your disk. If you want to use FreeBSD for the entire disk (which will delete all the other data on this disk when you confirm that you want sysinstall to continue later in the installation process) then you can press A, which corresponds to the Use Entire Disk option. The existing slices will be removed, and replaced with a small area flagged as unused (again, an artifact of PC disk layout), and then one large slice for FreeBSD. If you do this, then you should select the newly created FreeBSD slice using the arrow keys, and press S to mark the slice as being bootable. The screen will then look very similar to . Note the A in the Flags column, which indicates that this slice is active, and will be booted from. If you will be deleting an existing slice to make space for FreeBSD then you should select the slice using the arrow keys, and then press D. You can then press C, and be prompted for size of slice you want to create. Enter the appropriate figure and press Enter. The default value in this box represents the largest possible slice you can make, which could be the largest contiguous block of unallocated space or the size of the entire hard disk. If you have already made space for FreeBSD (perhaps by using a tool such as &partitionmagic;) then you can press C to create a new slice. Again, you will be prompted for the size of slice you would like to create.
Fdisk Partition Using Entire Disk
When finished, press Q. Your changes will be saved in sysinstall, but will not yet be written to disk. Install a Boot Manager You now have the option to install a boot manager. In general, you should choose to install the FreeBSD boot manager if: You have more than one drive, and have installed FreeBSD onto a drive other than the first one. You have installed FreeBSD alongside another operating system on the same disk, and you want to choose whether to start FreeBSD or the other operating system when you start the computer. If FreeBSD is going to be the only operating system on this machine, installed on the first hard disk, then the Standard boot manager will suffice. Choose None if you are using a third-party boot manager capable of booting FreeBSD. Make your choice and press Enter.
Sysinstall Boot Manager Menu
The help screen, reached by pressing F1, discusses the problems that can be encountered when trying to share the hard disk between operating systems. Creating Slices on Another Drive If there is more than one drive, it will return to the Select Drives screen after the boot manager selection. If you wish to install FreeBSD on to more than one disk, then you can select another disk here and repeat the slice process using FDisk. If you are installing FreeBSD on a drive other than your first, then the FreeBSD boot manager needs to be installed on both drives.
Exit Select Drive
The Tab key toggles between the last drive selected, &gui.ok;, and &gui.cancel;. Press the Tab once to toggle to the &gui.ok;, then press Enter to continue with the installation. Creating Partitions Using <application>Disklabel</application> You must now create some partitions inside each slice that you have just created. Remember that each partition is lettered, from a through to h, and that partitions b, c, and d have conventional meanings that you should adhere to. Certain applications can benefit from particular partition schemes, especially if you are laying out partitions across more than one disk. However, for this, your first FreeBSD installation, you do not need to give too much thought to how you partition the disk. It is more important that you install FreeBSD and start learning how to use it. You can always re-install FreeBSD to change your partition scheme when you are more familiar with the operating system. This scheme features four partitions—one for swap space, and three for filesystems. Partition Layout for First Disk Partition Filesystem Size Description a / 100 MB This is the root filesystem. Every other filesystem will be mounted somewhere under this one. 100 MB is a reasonable size for this filesystem. You will not be storing too much data on it, as a regular FreeBSD install will put about 40 MB of data here. The remaining space is for temporary data, and also leaves expansion space if future versions of FreeBSD need more space in /. b N/A 2-3 x RAM The system's swap space is kept on this partition. Choosing the right amount of swap space can be a bit of an art. A good rule of thumb is that your swap space should be two or three times as much as the available physical memory (RAM). You should also have at least 64 MB of swap, so if you have less than 32 MB of RAM in your computer then set the swap amount to 64 MB. If you have more than one disk then you can put swap space on each disk. FreeBSD will then use each disk for swap, which effectively speeds up the act of swapping. In this case, calculate the total amount of swap you need (e.g., 128 MB), and then divide this by the number of disks you have (e.g., two disks) to give the amount of swap you should put on each disk, in this example, 64 MB of swap per disk. e /var 50 MB The /var directory contains files that are constantly varying; log files, and other administrative files. Many of these files are read-from or written-to extensively during FreeBSD's day-to-day running. Putting these files on another filesystem allows FreeBSD to optimize the access of these files without affecting other files in other directories that do not have the same access pattern. f /usr Rest of disk All your other files will typically be stored in /usr and its subdirectories.
If you will be installing FreeBSD on to more than one disk then you must also create partitions in the other slices that you configured. The easiest way to do this is to create two partitions on each disk, one for the swap space, and one for a filesystem. Partition Layout for Subsequent Disks Partition Filesystem Size Description b N/A See description As already discussed, you can split swap space across each disk. Even though the a partition is free, convention dictates that swap space stays on the b partition. e /diskn Rest of disk The rest of the disk is taken up with one big partition. This could easily be put on the a partition, instead of the e partition. However, convention says that the a partition on a slice is reserved for the filesystem that will be the root (/) filesystem. You do not have to follow this convention, but sysinstall does, so following it yourself makes the installation slightly cleaner. You can choose to mount this filesystem anywhere; this example suggests that you mount them as directories /diskn, where n is a number that changes for each disk. But you can use another scheme if you prefer.
Having chosen your partition layout you can now create it using sysinstall. You will see this message: Message Now, you need to create BSD partitions inside of the fdisk partition(s) just created. If you have a reasonable amount of disk space (200MB or more) and don't have any special requirements, simply use the (A)uto command to allocate space automatically. If you have more specific needs or just don't care for the layout chosen by (A)uto, press F1 for more information on manual layout. [ OK ] [ Press enter or space ] Press Enter to start the FreeBSD partition editor, called Disklabel. shows the display when you first start Disklabel. The display is divided in to three sections. The first few lines show the name of the disk you are currently working on, and the slice that contains the partitions you are creating (at this point Disklabel calls this the Partition name rather than slice name). This display also shows the amount of free space within the slice; that is, space that was set aside in the slice, but that has not yet been assigned to a partition. The middle of the display shows the partitions that have been created, the name of the filesystem that each partition contains, their size, and some options pertaining to the creation of the filesystem. The bottom third of the screen shows the keystrokes that are valid in Disklabel.
Sysinstall Disklabel Editor
Disklabel can automatically create partitions for you and assign them default sizes. Try this now, by Pressing A. You will see a display similar to that shown in . Depending on the size of the disk you are using, the defaults may or may not be appropriate. This does not matter, as you do not have to accept the defaults. Beginning with FreeBSD 4.5, the default partitioning assigns the /tmp directory its own partition instead of being part of the / partition. This helps avoid filling the / partition with temporary files.
Sysinstall Disklabel Editor with Auto Defaults
If you choose to not use the default partitions and wish to replace them with your own, use the arrow keys to select the first partition, and press D to delete it. Repeat this to delete all the suggested partitions. To create the first partition (a, mounted as / — root), make sure the proper disk slice at the top of the screen is selected and press C. A dialog box will appear prompting you for the size of the new partition (as shown in ). You can enter the size as the number of disk blocks you want to use, or as a number followed by either M for megabytes, G for gigabytes, or C for cylinders. Beginning with FreeBSD 5.X, users can: select UFS2 using the Custom Newfs (Z) option, create labels with Auto Defaults and modify them with the Custom Newfs option or add during the regular creation period. Do not forget to add for SoftUpdates if you use the Custom Newfs option!
Free Space for Root Partition
The default size shown will create a partition that takes up the rest of the slice. If you are using the partition sizes described in the earlier example, then delete the existing figure using Backspace, and then type in 64M, as shown in . Then press &gui.ok;.
Edit Root Partition Size
Having chosen the partition's size you will then be asked whether this partition will contain a filesystem or swap space. The dialog box is shown in . This first partition will contain a filesystem, so check that FS is selected and press Enter.
Choose the Root Partition Type
Finally, because you are creating a filesystem, you must tell Disklabel where the filesystem is to be mounted. The dialog box is shown in . The root filesystem's mount point is /, so type /, and then press Enter.
Choose the Root Mount Point
The display will then update to show you the newly created partition. You should repeat this procedure for the other partitions. When you create the swap partition, you will not be prompted for the filesystem mount point, as swap partitions are never mounted. When you create the final partition, /usr, you can leave the suggested size as is, to use the rest of the slice. Your final FreeBSD DiskLabel Editor screen will appear similar to , although your values chosen may be different. Press Q to finish.
Sysinstall Disklabel Editor
Choosing What to Install Select the Distribution Set Deciding which distribution set to install will depend largely on the intended use of the system and the amount of disk space available. The predefined options range from installing the smallest possible configuration to everything. Those who are new to &unix; and/or FreeBSD should almost certainly select one of these canned options. Customizing a distribution set is typically for the more experienced user. Press F1 for more information on the distribution set options and what they contain. When finished reviewing the help, pressing Enter will return to the Select Distributions Menu. If a graphical user interface is desired then a distribution set that is preceded by an X should be chosen. The configuration of &xfree86; and selection of a default desktop is part of the post-installation steps. The default version of &xfree86; that is installed depends on the version of the FreeBSD that you are installing. For FreeBSD versions prior to 4.6, &xfree86; 3.X is installed. For FreeBSD 4.6 and later, &xfree86; 4.X is the default. You should check to see whether your video card is supported at the &xfree86; web site. If your video card is not supported under the default version that FreeBSD will install, you should select a distribution without X for installation. After installation, install and configure the appropriate version of &xfree86; using the ports collection. If compiling a custom kernel is anticipated, select an option which includes the source code. For more information on why a custom kernel should be built or how to build a custom kernel, see . Obviously, the most versatile system is one that includes everything. If there is adequate disk space, select All as shown in by using the arrow keys and press Enter. If there is a concern about disk space consider using an option that is more suitable for the situation. Do not fret over the perfect choice, as other distributions can be added after installation.
Choose Distributions
Installing the Ports Collection After selecting the desired distribution, an opportunity to install the FreeBSD Ports Collection is presented. The ports collection is an easy and convenient way to install software. The ports collection does not contain the source code necessary to compile the software. Instead, it is a collection of files which automates the downloading, compiling and installation of third-party software packages. discusses how to use the ports collection. The installation program does not check to see if you have adequate space. Select this option only if you have adequate hard disk space. As of FreeBSD &rel.current;, the FreeBSD Ports Collection takes up about &ports.size; of disk space. You can safely assume a larger value for more recent versions of FreeBSD. User Confirmation Requested Would you like to install the FreeBSD ports collection? This will give you ready access to over &os.numports; ported software packages, at a cost of around &ports.size; of disk space when "clean" and possibly much more than that if a lot of the distribution tarballs are loaded (unless you have the extra CDs from a FreeBSD CD/DVD distribution available and can mount it on /cdrom, in which case this is far less of a problem). The ports collection is a very valuable resource and well worth having on your /usr partition, so it is advisable to say Yes to this option. For more information on the ports collection & the latest ports, visit: http://www.FreeBSD.org/ports [ Yes ] No Select &gui.yes; with the arrow keys to install the ports collection or &gui.no; to skip this option. Press Enter to continue. The Choose Distributions menu will redisplay.
Confirm Distributions
If satisfied with the options, select Exit with the arrow keys, ensure that &gui.ok; is highlighted, and pressing Enter to continue. Choosing Your Installation Media If Installing from a CDROM or DVD, use the arrow keys to highlight Install from a FreeBSD CD/DVD. Ensure that &gui.ok; is highlighted, then press Enter to proceed with the installation. For other methods of installation, select the appropriate option and follow the instructions. Press F1 to display the Online Help for installation media. Press Enter to return to the media selection menu.
Choose Installation Media
FTP Installation Modes installation network FTP There are three FTP installation modes you can choose from: active FTP, passive FTP, or via a HTTP proxy. FTP Active: Install from an FTP server This option will make all FTP transfers use Active mode. This will not work through firewalls, but will often work with older FTP servers that do not support passive mode. If your connection hangs with passive mode (the default), try active! FTP Passive: Install from an FTP server through a firewall FTP passive mode This option instructs sysinstall to use Passive mode for all FTP operations. This allows the user to pass through firewalls that do not allow incoming connections on random TCP ports. FTP via a HTTP proxy: Install from an FTP server through a http proxy FTP via a HTTP proxy This option instructs sysinstall to use the HTTP protocol (like a web browser) to connect to a proxy for all FTP operations. The proxy will translate the requests and send them to the FTP server. This allows the user to pass through firewalls that do not allow FTP at all, but offer a HTTP proxy. In this case, you have to specify the proxy in addition to the FTP server. For a proxy FTP server, you should usually give the name of the server you really want as a part of the username, after an @ sign. The proxy server then fakes the real server. For example, assuming you want to install from ftp.FreeBSD.org, using the proxy FTP server foo.example.com, listening on port 1024. In this case, you go to the options menu, set the FTP username to ftp@ftp.FreeBSD.org, and the password to your email address. As your installation media, you specify FTP (or passive FTP, if the proxy supports it), and the URL ftp://foo.example.com:1234/pub/FreeBSD. Since /pub/FreeBSD from ftp.FreeBSD.org is proxied under foo.example.com, you are able to install from that machine (which will fetch the files from ftp.FreeBSD.org as your installation requests them). Committing to the Installation The installation can now proceed if desired. This is also the last chance for aborting the installation to prevent changes to the hard drive. User Confirmation Requested Last Chance! Are you SURE you want to continue the installation? If you're running this on a disk with data you wish to save then WE STRONGLY ENCOURAGE YOU TO MAKE PROPER BACKUPS before proceeding! We can take no responsibility for lost disk contents! [ Yes ] No Select &gui.yes; and press Enter to proceed. The installation time will vary according to the distribution chosen, installation media, and the speed of the computer. There will be a series of messages displayed indicating the status. The installation is complete when the following message is displayed: Message Congratulations! You now have FreeBSD installed on your system. We will now move on to the final configuration questions. For any option you do not wish to configure, simply select No. If you wish to re-enter this utility after the system is up, you may do so by typing: /stand/sysinstall . [ OK ] [ Press enter to continue ] Press Enter to proceed with post-installation configurations. Selecting &gui.no; and pressing Enter will abort the installation so no changes will be made to your system. The following message will appear: Message Installation complete with some errors. You may wish to scroll through the debugging messages on VTY1 with the scroll-lock feature. You can also choose "No" at the next prompt and go back into the installation menus to retry whichever operations have failed. [ OK ] This message is generated because nothing was installed. Pressing Enter will return to the Main Installation Menu to exit the installation. Post-installation Configuration of various options follows the successful installation. An option can be configured by re-entering the configuration options before booting the new FreeBSD system or after installation using /stand/sysinstall and selecting Configure. Network Device Configuration If you previously configured PPP for an FTP install, this screen will not display and can be configured later as described above. For detailed information on Local Area Networks and configuring FreeBSD as a gateway/router refer to the Advanced Networking chapter. User Confirmation Requested Would you like to configure any Ethernet or SLIP/PPP network devices? [ Yes ] No To configure a network device, select &gui.yes; and press Enter. Otherwise, select &gui.no; to continue.
Selecting an Ethernet Device
Select the interface to be configured with the arrow keys and press Enter. User Confirmation Requested Do you want to try IPv6 configuration of the interface? Yes [ No ] In this private local area network, the current Internet type protocol (IPv4) was sufficient and &gui.no; was selected with the arrow keys and Enter pressed. If you are connected to an existing IPv6 network with an RA server, then choose &gui.yes; and press Enter. It will take several seconds to scan for RA servers. User Confirmation Requested Do you want to try DHCP configuration of the interface? Yes [ No ] If DHCP (Dynamic Host Configuration Protocol) is not required select &gui.no; with the arrow keys and press Enter. Selecting &gui.yes; will execute dhclient, and if successful, will fill in the network configuration information automatically. Refer to for more information. The following Network Configuration screen shows the configuration of the Ethernet device for a system that will act as the gateway for a Local Area Network.
Set Network Configuration for ed0
Use Tab to select the information fields and fill in appropriate information: Host The fully-qualified hostname, such as k6-2.example.com in this case. Domain The name of the domain that your machine is in, such as example.com for this case. IPv4 Gateway IP address of host forwarding packets to non-local destinations. You must fill this in if the machine is a node on the network. Leave this field blank if the machine is the gateway to the Internet for the network. The IPv4 Gateway is also known as the default gateway or default route. Name server IP address of your local DNS server. There is no local DNS server on this private local area network so the IP address of the provider's DNS server (208.163.10.2) was used. IPv4 address The IP address to be used for this interface was 192.168.0.1 Netmask The address block being used for this local area network is a Class C block (192.168.0.0 - 192.168.255.255). The default netmask is for a Class C network (255.255.255.0). Extra options to ifconfig Any interface-specific options to ifconfig you would like to add. There were none in this case. Use Tab to select &gui.ok; when finished and press Enter. User Confirmation Requested Would you like to Bring Up the ed0 interface right now? [ Yes ] No Choosing &gui.yes; and pressing Enter will bring the machine up on the network and be ready for use. However, this does not accomplish much during installation, since the machine still needs to be rebooted. Configure Gateway User Confirmation Requested Do you want this machine to function as a network gateway? [ Yes ] No If the machine will be acting as the gateway for a local area network and forwarding packets between other machines then select &gui.yes; and press Enter. If the machine is a node on a network then select &gui.no; and press Enter to continue. Configure Internet Services User Confirmation Requested Do you want to configure inetd and the network services that it provides? Yes [ No ] If &gui.no; is selected, various services such telnetd will not be enabled. This means that remote users will not be able to telnet into this machine. Local users will be still be able to access remote machines with telnet. These services can be enabled after installation by editing /etc/inetd.conf with your favorite text editor. See for more information. Select &gui.yes; if you wish to configure these services during install. An additional confirmation will display: User Confirmation Requested The Internet Super Server (inetd) allows a number of simple Internet services to be enabled, including finger, ftp and telnetd. Enabling these services may increase risk of security problems by increasing the exposure of your system. With this in mind, do you wish to enable inetd? [ Yes ] No Select &gui.yes; to continue. User Confirmation Requested inetd(8) relies on its configuration file, /etc/inetd.conf, to determine which of its Internet services will be available. The default FreeBSD inetd.conf(5) leaves all services disabled by default, so they must be specifically enabled in the configuration file before they will function, even once inetd(8) is enabled. Note that services for IPv6 must be separately enabled from IPv4 services. Select [Yes] now to invoke an editor on /etc/inetd.conf, or [No] to use the current settings. [ Yes ] No Selecting &gui.yes; will allow adding services by deleting the # at the beginning of a line.
Editing <filename>inetd.conf</filename>
After adding the desired services, pressing Esc will display a menu which will allow exiting and saving the changes. Anonymous FTP User Confirmation Requested Do you want to have anonymous FTP access to this machine? Yes [ No ] Deny Anonymous FTP Selecting the default &gui.no; and pressing Enter will still allow users who have accounts with passwords to use FTP to access the machine. Allow Anonymous FTP Anyone can access your machine if you elect to allow anonymous FTP connections. The security implications should be considered before enabling this option. For more information about security see . To allow anonymous FTP, use the arrow keys to select &gui.yes; and press Enter. The following screen (or similar) will display:
Default Anonymous FTP Configuration
Pressing F1 will display the help: This screen allows you to configure the anonymous FTP user. The following configuration values are editable: UID: The user ID you wish to assign to the anonymous FTP user. All files uploaded will be owned by this ID. Group: Which group you wish the anonymous FTP user to be in. Comment: String describing this user in /etc/passwd FTP Root Directory: Where files available for anonymous FTP will be kept. Upload subdirectory: Where files uploaded by anonymous FTP users will go. The ftp root directory will be put in /var by default. If you do not have enough room there for the anticipated FTP needs, the /usr directory could be used by setting the FTP Root Directory to /usr/ftp. When you are satisfied with the values, press Enter to continue. User Confirmation Requested Create a welcome message file for anonymous FTP users? [ Yes ] No If you select &gui.yes; and press Enter, an editor will automatically start allowing you to edit the message.
Edit the FTP Welcome Message
This is a text editor called ee. Use the instructions to change the message or change the message later using a text editor of your choice. Note the file name/location at the bottom of the editor screen. Press Esc and a pop-up menu will default to a) leave editor. Press Enter to exit and continue. Press Enter again to save changes if you made any. Configure Network File System Network File System (NFS) allows sharing of files across a network. A machine can be configured as a server, a client, or both. Refer to for a more information. NFS Server User Confirmation Requested Do you want to configure this machine as an NFS server? Yes [ No ] If there is no need for a Network File System server, select &gui.no; and press Enter. If &gui.yes; is chosen, a message will pop-up indicating that the exports file must be created. Message Operating as an NFS server means that you must first configure an /etc/exports file to indicate which hosts are allowed certain kinds of access to your local filesystems. Press [Enter] now to invoke an editor on /etc/exports [ OK ] Press Enter to continue. A text editor will start allowing the exports file to be created and edited.
Editing <filename>exports</filename>
Use the instructions to add the actual exported filesystems now or later using a text editor of your choice. Note the file name/location at the bottom of the editor screen. Press Esc and a pop-up menu will default to a) leave editor. Press Enter to exit and continue. NFS Client The NFS client allows your machine to access NFS servers. User Confirmation Requested Do you want to configure this machine as an NFS client? Yes [ No ] With the arrow keys, select &gui.yes; or &gui.no; as appropriate and press Enter. Security Profile A security profile is a set of configuration options that attempts to achieve the desired ratio of security to convenience by enabling and disabling certain programs and other settings. The more severe the security profile, the fewer programs will be enabled by default. This is one of the basic principles of security: do not run anything except what you must. Please note that the security profile is just a default setting. All programs can be enabled and disabled after you have installed FreeBSD by editing or adding the appropriate line(s) to /etc/rc.conf. For more information, please see the &man.rc.conf.5; manual page. The following table describes what each of the security profiles does. The columns are the choices you have for a security profile, and the rows are the program or feature that the profile enables or disables. Possible Security Profiles Extreme Moderate &man.sendmail.8; NO YES &man.sshd.8; NO YES &man.portmap.8; NO MAYBE The portmapper is enabled if the machine has been configured as an NFS client or server earlier in the installation. NFS server NO YES &man.securelevel.8; YES If you choose a security profile that sets the securelevel to Extreme or High, you must be aware of the implications. Please read the &man.init.8; manual page and pay particular attention to the meanings of the security levels, or you may have significant trouble later! NO
User Confirmation Requested Do you want to select a default security profile for this host (select No for "medium" security)? [ Yes ] No Selecting &gui.no; and pressing Enter will set the security profile to medium. Selecting &gui.yes; and pressing Enter will allow selecting a different security profile.
Security Profile Options
Press F1 to display the help. Press Enter to return to selection menu. Use the arrow keys to choose Medium unless your are sure that another level is required for your needs. With &gui.ok; highlighted, press Enter. An appropriate confirmation message will display depending on which security setting was chosen. Message Moderate security settings have been selected. Sendmail and SSHd have been enabled, securelevels are disabled, and NFS server setting have been left intact. PLEASE NOTE that this still does not save you from having to properly secure your system in other ways or exercise due diligence in your administration, this simply picks a standard set of out-of-box defaults to start with. To change any of these settings later, edit /etc/rc.conf [OK] Message Extreme security settings have been selected. Sendmail, SSHd, and NFS services have been disabled, and securelevels have been enabled. PLEASE NOTE that this still does not save you from having to properly secure your system in other ways or exercise due diligence in your administration, this simply picks a more secure set of out-of-box defaults to start with. To change any of these settings later, edit /etc/rc.conf [OK] Press Enter to continue with the post-installation configuration. The security profile is not a silver bullet! Even if you use the extreme setting, you need to keep up with security issues by reading an appropriate mailing list (), using good passwords and passphrases, and generally adhering to good security practices. It simply sets up the desired security to convenience ratio out of the box. System Console Settings There are several options available to customize the system console. User Confirmation Requested Would you like to customize your system console settings? [ Yes ] No To view and configure the options, select &gui.yes; and press Enter.
System Console Configuration Options
A commonly used option is the screen saver. Use the arrow keys to select Saver and then press Enter.
Screen Saver Options
Select the desired screen saver using the arrow keys and then press Enter. The System Console Configuration menu will redisplay. The default time interval is 300 seconds. To change the time interval, select Saver again. At the Screen Saver Options menu, select Timeout using the arrow keys and press Enter. A pop-up menu will appear:
Screen Saver Timeout
The value can be changed, then select &gui.ok; and press Enter to return to the System Console Configuration menu.
System Console Configuration Exit
Selecting Exit and pressing Enter will continue with the post-installation configurations. Setting the Time Zone Setting the time zone for your machine will allow it to automatically correct for any regional time changes and perform other time zone related functions properly. The example shown is for a machine located in the Eastern time zone of the United States. Your selections will vary according to your geographical location. User Confirmation Requested Would you like to set this machine's time zone now? [ Yes ] No Select &gui.yes; and press Enter to set the time zone. User Confirmation Requested Is this machine's CMOS clock set to UTC? If it is set to local time or you don't know, please choose NO here! Yes [ No ] Select &gui.yes; or &gui.no; according to how the machine's clock is configured and press Enter.
Select Your Region
The appropriate region is selected using the arrow keys and then pressing Enter.
Select Your Country
Select the appropriate country using the arrow keys and press Enter.
Select Your Time Zone
The appropriate time zone is selected using the arrow keys and pressing Enter. Confirmation Does the abbreviation 'EDT' look reasonable? [ Yes ] No Confirm the abbreviation for the time zone is correct. If it looks okay, press Enter to continue with the post-installation configuration. Linux Compatibility User Confirmation Requested Would you like to enable Linux binary compatibility? [ Yes ] No Selecting &gui.yes; and pressing Enter will allow running Linux software on FreeBSD. The install will add the appropriate packages for Linux compatibility. If installing by FTP, the machine will need to be connected to the Internet. Sometimes a remote ftp site will not have all the distributions like the Linux binary compatibility. This can be installed later if necessary. Mouse Settings This option will allow you to cut and paste text in the console and user programs with a 3-button mouse. If using a 2-button mouse, refer to manual page, &man.moused.8;, after installation for details on emulating the 3-button style. This example depicts a non-USB mouse configuration (such as a PS/2 or COM port mouse): User Confirmation Requested Does this system have a non-USB mouse attached to it? [ Yes ] No Select &gui.yes; for a non-USB mouse or &gui.no; for a USB mouse and press Enter.
Select Mouse Protocol Type
Use the arrow keys to select Type and press Enter.
Set Mouse Protocol
The mouse used in this example is a PS/2 type, so the default Auto was appropriate. To change protocol, use the arrow keys to select another option. Ensure that &gui.ok; is highlighted and press Enter to exit this menu.
Configure Mouse Port
Use the arrow keys to select Port and press Enter.
Setting the Mouse Port
This system had a PS/2 mouse, so the default PS/2 was appropriate. To change the port, use the arrow keys and then press Enter.
Enable the Mouse Daemon
Last, use the arrow keys to select Enable, and press Enter to enable and test the mouse daemon.
Test the Mouse Daemon
Move the mouse around the screen and verify the cursor shown responds properly. If it does, select &gui.yes; and press Enter. If not, the mouse has not been configured correctly — select &gui.no; and try using different configuration options. Select Exit with the arrow keys and press Enter to return to continue with the post-installation configuration. Configure Additional Network Services Configuring network services can be a daunting task for new users if they lack previous knowledge in this area. Networking, including the Internet, is critical to all modern operating systems including &os;; as a result, it is very useful to have some understanding &os;'s extensive networking capabilities. Doing this during the installation will ensure users have some understanding of the various services available to them. Network services are programs that accept input from anywhere on the network. Every effort is made to make sure these programs will not do anything harmful. Unfortunately, programmers are not perfect and through time there have been cases where bugs in network services have been exploited by attackers to do bad things. It is important that you only enable the network services you know that you need. If in doubt it is best if you do not enable a network service until you find out that you do need it. You can always enable it later by re-running sysinstall or by using the features provided by the /etc/rc.conf file. Selecting the Networking option will display a menu similar to the one below:
Network Configuration Upper-level
The first option, Interfaces, was previously covered during the , thus this option can safely be ignored. Selecting the AMD option adds support for the BSD automatic mount utility. This is usually used in conjunction with the NFS protocol (see below) for automatically mounting remote file systems. No special configuration is required here. Next in line is the AMD Flags option. When selected, a menu will pop up for you to enter specific AMD flags. The menu already contains a set of default options: -a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map The option sets the default mount location which is specified here as /.amd_mnt. The option specifies the default log file; however, when syslogd is used all log activity will be sent to the system log daemon. The - /host directory is used + /host directory is used to mount an exported file system from a remote - host, while /net + host, while /net directory is used to mount an exported file system from an IP address. The /etc/amd.map file defines the default options for AMD exports. The Anon FTP option permits anonymous FTP connections. Select this option to make this machine an anonymous FTP server. Be aware of the security risks involved with this option. Another menu will be displayed to explain the security risks and configuration in depth. The Gateway configuration menu will set the machine up to be a gateway as explained previously. This can be used to unset the Gateway option if you accidentally selected it during the installation process. The Inetd option can be used to configure or completely disable the &man.inetd.8; daemon as discussed above. The Mail option is used to configure the system's default MTA or Mail Transfer Agent. Selecting this option will bring up the following menu:
Select a default MTA
Here you are offered a choice as to which MTA to install and set as the default. An MTA is nothing more than a mail server which delivers email to users on the system or the Internet. Selecting Sendmail will install the popular sendmail server which is the &os; default. The Sendmail local option will set sendmail to be the default MTA, but disable its ability to receive incoming email from the Internet. The other options here, Postfix and Exim act similar to Sendmail. They both deliver email; however, some users prefer these alternatives to the sendmail MTA. After selecting an MTA, or choosing not to select an MTA, the network configuration menu will appear with the next option being NFS client. The NFS client option will configure the system to communicate with a server via NFS. An NFS server makes file systems available to other machines on the network via the NFS protocol. If this is a stand alone machine, this option can remain unselected. The system may require more configuration later; see for more information about client and server configuration. Below that option is the NFS server option, permitting you to set the system up as an NFS server. This adds the required information to start up the RPC remote procedure call services. RPC is used to coordinate connections between hosts and programs. Next in line is the Ntpdate option, which deals with time synchronization. When selected, a menu like the one below shows up:
Ntpdate Configuration
From this menu, select the server which is the closest to your location. Selecting a close one will make the time synchronization more accurate as a server further from your location may have more connection latency. The next option is the PCNFSD selection. This option will install the net/pcnfsd package from the ports collection. This is a useful utility which provides NFS authentication services for systems which are unable to provide their own, such as Microsoft's &ms-dos; operating system. Now you must scroll down a bit to see the other options:
Network Configuration Lower-level
The &man.rpcbind.8;, &man.rpc.statd.8;, and &man.rpc.lockd.8; utilities are all used for Remote Procedure Calls (RPC). The rpcbind utility manages communication between NFS servers and clients, and is required for NFS servers to operate correctly. The rpc.statd daemon interacts with the rpc.statd daemon on other hosts to provide status monitoring. The reported status is usually held in the /var/db/statd.status file. The next option listed here is the rpc.lockd option, which, when selected, will provide file locking services. This is usually used with rpc.statd to monitor what hosts are requesting locks and how frequently they request them. While these last two options are marvelous for debugging, they are not required for NFS servers and clients to operate correctly. As you progress down the list the next item here is Routed, which is the routing daemon. The &man.routed.8; utility manages network routing tables, discovers multicast routers, and supplies a copy of the routing tables to any physically connected host on the network upon request. This is mainly used for machines which act as a gateway for the local network. When selected, a menu will be presented requesting the default location of the utility. The default location is already defined for you and can be selected with the Enter key. You will then be presented with yet another menu, this time asking for the flags you wish to pass on to routed. The default is and it should already appear on the screen. Next in line is the Rwhod option which, when selected, will start the &man.rwhod.8; daemon during system initialization. The rwhod utility broadcasts system messages across the network periodically, or collects them when in consumer mode. More information can be found in the &man.ruptime.1; and &man.rwho.1; manual pages. The next to the last option in the list is for the &man.sshd.8; daemon. This is the secure shell server for OpenSSH and it is highly recommended over the standard telnet and FTP servers. The sshd server is used to create a secure connection from one host to another by using encrypted connections. Finally there is the TCP Extensions option. This enables the TCP Extensions defined in RFC 1323 and RFC 1644. While on many hosts this can speed up connections, it can also cause some connections to be dropped. It is not recommended for servers, but may be beneficial for stand alone machines. Now that you have configured the network services, you can scroll up to the very top item which is Exit and continue on to the next configuration section. Configure X Server In order to use a graphical user interface such as KDE, GNOME, or others, the X server will need to be configured. In order to run &xfree86; as a non root user you will need to have x11/wrapper installed. This is installed by default beginning with FreeBSD 4.7. For earlier versions this can be added from the Package Selection menu. To see whether your video card is supported, check the &xfree86; web site. User Confirmation Requested Would you like to configure your X server at this time? [ Yes ] No It is necessary to know your monitor specifications and video card information. Equipment damage can occur if settings are incorrect. If you do not have this information, select &gui.no; and perform the configuration after installation when you have the information using /stand/sysinstall, selecting Configure and then XFree86. Improper configuration of the X server at this time can leave the machine in a frozen state. It is often advised to configure the X server once the installation has completed. If you have graphics card and monitor information, select &gui.yes; and press Enter to proceed with configuring the X server.
Select Configuration Method Menu
There are several ways to configure the X server. Use the arrow keys to select one of the methods and press Enter. Be sure to read all instructions carefully. The xf86cfg and xf86cfg -textmode methods may make the screen go dark and take a few seconds to start. Be patient. The following will illustrate the use of the xf86config configuration tool. The configuration choices you make will depend on the hardware in the system so your choices will probably be different than those shown: Message You have configured and been running the mouse daemon. Choose "/dev/sysmouse" as the mouse port and "SysMouse" or "MouseSystems" as the mouse protocol in the X configuration utility. [ OK ] [ Press enter to continue ] This indicates that the mouse daemon previously configured has been detected. Press Enter to continue. Starting xf86config will display a brief introduction: This program will create a basic XF86Config file, based on menu selections you make. The XF86Config file usually resides in /usr/X11R6/etc/X11 or /etc/X11. A sample XF86Config file is supplied with XFree86; it is configured for a standard VGA card and monitor with 640x480 resolution. This program will ask for a pathname when it is ready to write the file. You can either take the sample XF86Config as a base and edit it for your configuration, or let this program produce a base XF86Config file for your configuration and fine-tune it. Before continuing with this program, make sure you know what video card you have, and preferably also the chipset it uses and the amount of video memory on your video card. SuperProbe may be able to help with this. Press enter to continue, or ctrl-c to abort. Pressing Enter will start the mouse configuration. Be sure to follow the instructions and use Mouse Systems as the mouse protocol and /dev/sysmouse as the mouse port even if using a PS/2 mouse is shown as an illustration. First specify a mouse protocol type. Choose one from the following list: 1. Microsoft compatible (2-button protocol) 2. Mouse Systems (3-button protocol) & FreeBSD moused protocol 3. Bus Mouse 4. PS/2 Mouse 5. Logitech Mouse (serial, old type, Logitech protocol) 6. Logitech MouseMan (Microsoft compatible) 7. MM Series 8. MM HitTablet 9. Microsoft IntelliMouse If you have a two-button mouse, it is most likely of type 1, and if you have a three-button mouse, it can probably support both protocol 1 and 2. There are two main varieties of the latter type: mice with a switch to select the protocol, and mice that default to 1 and require a button to be held at boot-time to select protocol 2. Some mice can be convinced to do 2 by sending a special sequence to the serial port (see the ClearDTR/ClearRTS options). Enter a protocol number: 2 You have selected a Mouse Systems protocol mouse. If your mouse is normally in Microsoft-compatible mode, enabling the ClearDTR and ClearRTS options may cause it to switch to Mouse Systems mode when the server starts. Please answer the following question with either 'y' or 'n'. Do you want to enable ClearDTR and ClearRTS? n You have selected a three-button mouse protocol. It is recommended that you do not enable Emulate3Buttons, unless the third button doesn't work. Please answer the following question with either 'y' or 'n'. Do you want to enable Emulate3Buttons? y Now give the full device name that the mouse is connected to, for example /dev/tty00. Just pressing enter will use the default, /dev/mouse. On FreeBSD, the default is /dev/sysmouse. Mouse device: /dev/sysmouse The keyboard is the next item to be configured. A generic 101-key model is shown for illustration. Any name may be used for the variant or simply press Enter to accept the default value. Please select one of the following keyboard types that is the better description of your keyboard. If nothing really matches, choose 1 (Generic 101-key PC) 1 Generic 101-key PC 2 Generic 102-key (Intl) PC 3 Generic 104-key PC 4 Generic 105-key (Intl) PC 5 Dell 101-key PC 6 Everex STEPnote 7 Keytronic FlexPro 8 Microsoft Natural 9 Northgate OmniKey 101 10 Winbook Model XP5 11 Japanese 106-key 12 PC-98xx Series 13 Brazilian ABNT2 14 HP Internet 15 Logitech iTouch 16 Logitech Cordless Desktop Pro 17 Logitech Internet Keyboard 18 Logitech Internet Navigator Keyboard 19 Compaq Internet 20 Microsoft Natural Pro 21 Genius Comfy KB-16M 22 IBM Rapid Access 23 IBM Rapid Access II 24 Chicony Internet Keyboard 25 Dell Internet Keyboard Enter a number to choose the keyboard. 1 Please select the layout corresponding to your keyboard 1 U.S. English 2 U.S. English w/ ISO9995-3 3 U.S. English w/ deadkeys 4 Albanian 5 Arabic 6 Armenian 7 Azerbaidjani 8 Belarusian 9 Belgian 10 Bengali 11 Brazilian 12 Bulgarian 13 Burmese 14 Canadian 15 Croatian 16 Czech 17 Czech (qwerty) 18 Danish Enter a number to choose the country. Press enter for the next page 1 Please enter a variant name for 'us' layout. Or just press enter for default variant us Please answer the following question with either 'y' or 'n'. Do you want to select additional XKB options (group switcher, group indicator, etc.)? n Next, we proceed to the configuration for the monitor. Do not exceed the ratings of your monitor. Damage could occur. If you have any doubts, do the configuration after you have the information. Now we want to set the specifications of the monitor. The two critical parameters are the vertical refresh rate, which is the rate at which the whole screen is refreshed, and most importantly the horizontal sync rate, which is the rate at which scanlines are displayed. The valid range for horizontal sync and vertical sync should be documented in the manual of your monitor. If in doubt, check the monitor database /usr/X11R6/lib/X11/doc/Monitors to see if your monitor is there. Press enter to continue, or ctrl-c to abort. You must indicate the horizontal sync range of your monitor. You can either select one of the predefined ranges below that correspond to industry- standard monitor types, or give a specific range. It is VERY IMPORTANT that you do not specify a monitor type with a horizontal sync range that is beyond the capabilities of your monitor. If in doubt, choose a conservative setting. hsync in kHz; monitor type with characteristic modes 1 31.5; Standard VGA, 640x480 @ 60 Hz 2 31.5 - 35.1; Super VGA, 800x600 @ 56 Hz 3 31.5, 35.5; 8514 Compatible, 1024x768 @ 87 Hz interlaced (no 800x600) 4 31.5, 35.15, 35.5; Super VGA, 1024x768 @ 87 Hz interlaced, 800x600 @ 56 Hz 5 31.5 - 37.9; Extended Super VGA, 800x600 @ 60 Hz, 640x480 @ 72 Hz 6 31.5 - 48.5; Non-Interlaced SVGA, 1024x768 @ 60 Hz, 800x600 @ 72 Hz 7 31.5 - 57.0; High Frequency SVGA, 1024x768 @ 70 Hz 8 31.5 - 64.3; Monitor that can do 1280x1024 @ 60 Hz 9 31.5 - 79.0; Monitor that can do 1280x1024 @ 74 Hz 10 31.5 - 82.0; Monitor that can do 1280x1024 @ 76 Hz 11 Enter your own horizontal sync range Enter your choice (1-11): 6 You must indicate the vertical sync range of your monitor. You can either select one of the predefined ranges below that correspond to industry- standard monitor types, or give a specific range. For interlaced modes, the number that counts is the high one (e.g. 87 Hz rather than 43 Hz). 1 50-70 2 50-90 3 50-100 4 40-150 5 Enter your own vertical sync range Enter your choice: 2 You must now enter a few identification/description strings, namely an identifier, a vendor name, and a model name. Just pressing enter will fill in default names. The strings are free-form, spaces are allowed. Enter an identifier for your monitor definition: Hitachi The selection of a video card driver from a list is next. If you pass your card on the list, continue to press Enter and the list will repeat. Only an excerpt from the list is shown: Now we must configure video card specific settings. At this point you can choose to make a selection out of a database of video card definitions. Because there can be variation in Ramdacs and clock generators even between cards of the same model, it is not sensible to blindly copy the settings (e.g. a Device section). For this reason, after you make a selection, you will still be asked about the components of the card, with the settings from the chosen database entry presented as a strong hint. The database entries include information about the chipset, what driver to run, the Ramdac and ClockChip, and comments that will be included in the Device section. However, a lot of definitions only hint about what driver to run (based on the chipset the card uses) and are untested. If you can't find your card in the database, there's nothing to worry about. You should only choose a database entry that is exactly the same model as your card; choosing one that looks similar is just a bad idea (e.g. a GemStone Snail 64 may be as different from a GemStone Snail 64+ in terms of hardware as can be). Do you want to look at the card database? y 288 Matrox Millennium G200 8MB mgag200 289 Matrox Millennium G200 SD 16MB mgag200 290 Matrox Millennium G200 SD 4MB mgag200 291 Matrox Millennium G200 SD 8MB mgag200 292 Matrox Millennium G400 mgag400 293 Matrox Millennium II 16MB mga2164w 294 Matrox Millennium II 4MB mga2164w 295 Matrox Millennium II 8MB mga2164w 296 Matrox Mystique mga1064sg 297 Matrox Mystique G200 16MB mgag200 298 Matrox Mystique G200 4MB mgag200 299 Matrox Mystique G200 8MB mgag200 300 Matrox Productiva G100 4MB mgag100 301 Matrox Productiva G100 8MB mgag100 302 MediaGX mediagx 303 MediaVision Proaxcel 128 ET6000 304 Mirage Z-128 ET6000 305 Miro CRYSTAL VRX Verite 1000 Enter a number to choose the corresponding card definition. Press enter for the next page, q to continue configuration. 288 Your selected card definition: Identifier: Matrox Millennium G200 8MB Chipset: mgag200 Driver: mga Do NOT probe clocks or use any Clocks line. Press enter to continue, or ctrl-c to abort. Now you must give information about your video card. This will be used for the "Device" section of your video card in XF86Config. You must indicate how much video memory you have. It is probably a good idea to use the same approximate amount as that detected by the server you intend to use. If you encounter problems that are due to the used server not supporting the amount memory you have (e.g. ATI Mach64 is limited to 1024K with the SVGA server), specify the maximum amount supported by the server. How much video memory do you have on your video card: 1 256K 2 512K 3 1024K 4 2048K 5 4096K 6 Other Enter your choice: 6 Amount of video memory in Kbytes: 8192 You must now enter a few identification/description strings, namely an identifier, a vendor name, and a model name. Just pressing enter will fill in default names (possibly from a card definition). Your card definition is Matrox Millennium G200 8MB. The strings are free-form, spaces are allowed. Enter an identifier for your video card definition: Next, the video modes are set for the resolutions desired. Typically, useful ranges are 640x480, 800x600, and 1024x768 but those are a function of video card capability, monitor size, and eye comfort. When selecting a color depth, select the highest mode that your card will support. For each depth, a list of modes (resolutions) is defined. The default resolution that the server will start-up with will be the first listed mode that can be supported by the monitor and card. Currently it is set to: "640x480" "800x600" "1024x768" "1280x1024" for 8-bit "640x480" "800x600" "1024x768" "1280x1024" for 16-bit "640x480" "800x600" "1024x768" "1280x1024" for 24-bit Modes that cannot be supported due to monitor or clock constraints will be automatically skipped by the server. 1 Change the modes for 8-bit (256 colors) 2 Change the modes for 16-bit (32K/64K colors) 3 Change the modes for 24-bit (24-bit color) 4 The modes are OK, continue. Enter your choice: 2 Select modes from the following list: 1 "640x400" 2 "640x480" 3 "800x600" 4 "1024x768" 5 "1280x1024" 6 "320x200" 7 "320x240" 8 "400x300" 9 "1152x864" a "1600x1200" b "1800x1400" c "512x384" Please type the digits corresponding to the modes that you want to select. For example, 432 selects "1024x768" "800x600" "640x480", with a default mode of 1024x768. Which modes? 432 You can have a virtual screen (desktop), which is screen area that is larger than the physical screen and which is panned by moving the mouse to the edge of the screen. If you don't want virtual desktop at a certain resolution, you cannot have modes listed that are larger. Each color depth can have a differently-sized virtual screen Please answer the following question with either 'y' or 'n'. Do you want a virtual screen that is larger than the physical screen? n For each depth, a list of modes (resolutions) is defined. The default resolution that the server will start-up with will be the first listed mode that can be supported by the monitor and card. Currently it is set to: "640x480" "800x600" "1024x768" "1280x1024" for 8-bit "1024x768" "800x600" "640x480" for 16-bit "640x480" "800x600" "1024x768" "1280x1024" for 24-bit Modes that cannot be supported due to monitor or clock constraints will be automatically skipped by the server. 1 Change the modes for 8-bit (256 colors) 2 Change the modes for 16-bit (32K/64K colors) 3 Change the modes for 24-bit (24-bit color) 4 The modes are OK, continue. Enter your choice: 4 Please specify which color depth you want to use by default: 1 1 bit (monochrome) 2 4 bits (16 colors) 3 8 bits (256 colors) 4 16 bits (65536 colors) 5 24 bits (16 million colors) Enter a number to choose the default depth. 4 Finally, the configuration needs to be saved. Be sure to enter /etc/XF86Config as the location for saving the configuration. I am going to write the XF86Config file now. Make sure you don't accidently overwrite a previously configured one. Shall I write it to /etc/X11/XF86Config? y If the configuration fails, you can try the configuration again by selecting &gui.yes; when the following message appears: User Confirmation Requested The XFree86 configuration process seems to have failed. Would you like to try again? [ Yes ] No If you have trouble configuring &xfree86;, select &gui.no; and press Enter and continue with the installation process. After installation you can use xf86cfg -textmode or xf86config to access the command line configuration utilities as root. There is an additional method for configuring &xfree86; described in . If you choose not to configure &xfree86; at this time the next menu will be for package selection. The default setting which allows the server to be killed is the hotkey sequence CtrlAlt Backspace. This can be executed if something is wrong with the server settings and prevent hardware damage. The default setting that allows video mode switching will permit changing of the mode while running X with the hotkey sequence CtrlAlt+ or CtrlAlt- . After you have &xfree86; running, the display can be adjusted for height, width, or centering by using xvidtune. There are warnings that improper settings can damage your equipment. Heed them. If in doubt, do not do it. Instead, use the monitor controls to adjust the display for X Window. There may be some display differences when switching back to text mode, but it is better than damaging equipment. Read the &man.xvidtune.1; manual page before making any adjustments. Following a successful &xfree86; configuration, it will proceed to the selection of a default desktop. Select Default X Desktop There are a variety of window managers available. They range from very basic environments to full desktop environments with a large suite of software. Some require only minimal disk space and low memory while others with more features require much more. The best way to determine which is most suitable for you is to try a few different ones. Those are available from the ports collection or as packages and can be added after installation. You can select one of the popular desktops to be installed and configured as the default desktop. This will allow you to start it right after installation.
Select Default Desktop
Use the arrow keys to select a desktop and press Enter. Installation of the selected desktop will proceed. Install Packages Packages are pre-compiled binaries and are a convenient way to install software. Installation of one package is shown for purposes of illustration. Additional packages can also be added at this time if desired. After installation /stand/sysinstall can be used to add additional packages. User Confirmation Requested The FreeBSD package collection is a collection of hundreds of ready-to-run applications, from text editors to games to WEB servers and more. Would you like to browse the collection now? [ Yes ] No Selecting &gui.yes; and pressing Enter will be followed by the Package Selection screens:
Select Package Category
Only packages on the current installation media are available for installation at any given time. All packages available will be displayed if All is selected or you can select a particular category. Highlight your selection with the arrow keys and press Enter. A menu will display showing all the packages available for the selection made:
Select Packages
The bash shell is shown selected. Select as many as desired by highlighting the package and pressing the Space key. A short description of each package will appear in the lower left corner of the screen. Pressing the Tab key will toggle between the last selected package, &gui.ok;, and &gui.cancel;. When you have finished marking the packages for installation, press Tab once to toggle to the &gui.ok; and press Enter to return to the Package Selection menu. The left and right arrow keys will also toggle between &gui.ok; and &gui.cancel;. This method can also be used to select &gui.ok; and press Enter to return to the Package Selection menu.
Install Packages
Use the Tab and arrow keys to select [ Install ] and press Enter. You will then need to confirm that you want to install the packages:
Confirm Package Installation
Selecting &gui.ok; and pressing Enter will start the package installation. Installing messages will appear until completed. Make note if there are any error messages. The final configuration continues after packages are installed. If you end up not selecting any packages, and wish to return to the final configuration, select Install anyways. Add Users/Groups You should add at least one user during the installation so that you can use the system without being logged in as root. The root partition is generally small and running applications as root can quickly fill it. A bigger danger is noted below: User Confirmation Requested Would you like to add any initial user accounts to the system? Adding at least one account for yourself at this stage is suggested since working as the "root" user is dangerous (it is easy to do things which adversely affect the entire system). [ Yes ] No Select &gui.yes; and press Enter to continue with adding a user.
Select User
Select User with the arrow keys and press Enter.
Add User Information
The following descriptions will appear in the lower part of the screen as the items are selected with Tab to assist with entering the required information: Login ID The login name of the new user (mandatory). UID The numerical ID for this user (leave blank for automatic choice). Group The login group name for this user (leave blank for automatic choice). Password The password for this user (enter this field with care!). Full name The user's full name (comment). Member groups The groups this user belongs to (i.e. gets access rights for). Home directory The user's home directory (leave blank for default). Login shell The user's login shell (leave blank for default, e.g. /bin/sh). The login shell was changed from /bin/sh to /usr/local/bin/bash to use the bash shell that was previously installed as a package. Do not try to use a shell that does not exist or you will not be able to login. The most common shell used in the BSD-world is the C shell, which can be indicated as /bin/tcsh. The user was also added to the wheel group to be able to become a superuser with root privileges. When you are satisfied, press &gui.ok; and the User and Group Management menu will redisplay:
Exit User and Group Management
Groups can also be added at this time if specific needs are known. Otherwise, this may be accessed through using /stand/sysinstall after installation is completed. When you are finished adding users, select Exit with the arrow keys and press Enter to continue the installation. Set the <username>root</username> Password Message Now you must set the system manager's password. This is the password you'll use to log in as "root". [ OK ] [ Press enter to continue ] Press Enter to set the root password. The password will need to be typed in twice correctly. Needless to say, make sure you have a way of finding the password if you forget. Changing local password for root. New password : Retype new password : The installation will continue after the password is successfully entered. Exiting Install If you need to configure additional network devices or any other configuration, you can do it at this point or after installation with /stand/sysinstall. User Confirmation Requested Visit the general configuration menu for a chance to set any last options? Yes [ No ] Select &gui.no; with the arrow keys and press Enter to return to the Main Installation Menu.
Exit Install
Select [X Exit Install] with the arrow keys and press Enter. You will be asked to confirm exiting the installation: User Confirmation Requested Are you sure you wish to exit? The system will reboot (be sure to remove any floppies from the drives). [ Yes ] No Select &gui.yes; and remove the floppy if booting from the floppy. The CDROM drive is locked until the machine starts to reboot. The CDROM drive is then unlocked and the disk can be removed from drive (quickly). The system will reboot so watch for any error messages that may appear. FreeBSD Bootup FreeBSD Bootup on the &i386; If everything went well, you will see messages scroll off the screen and you will arrive at a login prompt. You can view the content of the messages by pressing Scroll-Lock and using PgUp and PgDn. Pressing Scroll-Lock again will return to the prompt. The entire message may not display (buffer limitation) but it can be viewed from the command line after logging in by typing dmesg at the prompt. Login using the username/password you set during installation (rpratt, in this example). Avoid logging in as root except when necessary. Typical boot messages (version information omitted): Copyright (c) 1992-2002 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. Timecounter "i8254" frequency 1193182 Hz CPU: AMD-K6(tm) 3D processor (300.68-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x580 Stepping = 0 Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX> AMD Features=0x80000800<SYSCALL,3DNow!> real memory = 268435456 (262144K bytes) config> di sn0 config> di lnc0 config> di le0 config> di ie0 config> di fe0 config> di cs0 config> di bt0 config> di aic0 config> di aha0 config> di adv0 config> q avail memory = 256311296 (250304K bytes) Preloaded elf kernel "kernel" at 0xc0491000. Preloaded userconfig_script "/boot/kernel.conf" at 0xc049109c. md0: Malloc disk Using $PIR table, 4 entries at 0xc00fde60 npx0: <math processor> on motherboard npx0: INT 16 interface pcib0: <Host to PCI bridge> on motherboard pci0: <PCI bus> on pcib0 pcib1: <VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 on pci0 pci1: <PCI bus> on pcib1 pci1: <Matrox MGA G200 AGP graphics accelerator> at 0.0 irq 11 isab0: <VIA 82C586 PCI-ISA bridge> at device 7.0 on pci0 isa0: <ISA bus> on isab0 atapci0: <VIA 82C586 ATA33 controller> port 0xe000-0xe00f at device 7.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 uhci0: <VIA 83C572 USB controller> port 0xe400-0xe41f irq 10 at device 7.2 on pci0 usb0: <VIA 83C572 USB controller> on uhci0 usb0: USB revision 1.0 uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered chip1: <VIA 82C586B ACPI interface> at device 7.3 on pci0 ed0: <NE2000 PCI Ethernet (RealTek 8029)> port 0xe800-0xe81f irq 9 at device 10.0 on pci0 ed0: address 52:54:05:de:73:1b, type NE2000 (16 bit) isa0: too many dependant configs (8) isa0: unexpected small tag 14 fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0 fdc0: FIFO enabled, 8 bytes threshold fd0: <1440-KB 3.5" drive> on fdc0 drive 0 atkbdc0: <keyboard controller (i8042)> at port 0x60-0x64 on isa0 atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0 kbd0 at atkbd0 psm0: <PS/2 Mouse> irq 12 on atkbdc0 psm0: model Generic PS/2 mouse, device ID 0 vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0 sc0: <System console> at flags 0x1 on isa0 sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/15 bytes threshold ppbus0: IEEE1284 device found /NIBBLE Probing for PnP devices on ppbus0: plip0: <PLIP network interface> on ppbus0 lpt0: <Printer> on ppbus0 lpt0: Interrupt-driven port ppi0: <Parallel I/O> on ppbus0 ad0: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata0-master using UDMA33 ad2: 8063MB <IBM-DHEA-38451> [16383/16/63] at ata1-master using UDMA33 acd0: CDROM <DELTA OTC-H101/ST3 F/W by OIPD> at ata0-slave using PIO4 Mounting root from ufs:/dev/ad0s1a swapon: adding /dev/ad0s1b as swap device Automatic boot in progress... /dev/ad0s1a: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1a: clean, 48752 free (552 frags, 6025 blocks, 0.9% fragmentation) /dev/ad0s1f: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1f: clean, 128997 free (21 frags, 16122 blocks, 0.0% fragmentation) /dev/ad0s1g: FILESYSTEM CLEAN; SKIPPING CHECKS /dev/ad0s1g: clean, 3036299 free (43175 frags, 374073 blocks, 1.3% fragmentation) /dev/ad0s1e: filesystem CLEAN; SKIPPING CHECKS /dev/ad0s1e: clean, 128193 free (17 frags, 16022 blocks, 0.0% fragmentation) Doing initial network setup: hostname. ed0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255 inet6 fe80::5054::5ff::fede:731b%ed0 prefixlen 64 tentative scopeid 0x1 ether 52:54:05:de:73:1b lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x8 inet6 ::1 prefixlen 128 inet 127.0.0.1 netmask 0xff000000 Additional routing options: IP gateway=YES TCP keepalive=YES routing daemons:. additional daemons: syslogd. Doing additional network setup:. Starting final network daemons: creating ssh RSA host key Generating public/private rsa1 key pair. Your identification has been saved in /etc/ssh/ssh_host_key. Your public key has been saved in /etc/ssh/ssh_host_key.pub. The key fingerprint is: cd:76:89:16:69:0e:d0:6e:f8:66:d0:07:26:3c:7e:2d root@k6-2.example.com creating ssh DSA host key Generating public/private dsa key pair. Your identification has been saved in /etc/ssh/ssh_host_dsa_key. Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub. The key fingerprint is: f9:a1:a9:47:c4:ad:f9:8d:52:b8:b8:ff:8c:ad:2d:e6 root@k6-2.example.com. setting ELF ldconfig path: /usr/lib /usr/lib/compat /usr/X11R6/lib /usr/local/lib a.out ldconfig path: /usr/lib/aout /usr/lib/compat/aout /usr/X11R6/lib/aout starting standard daemons: inetd cron sshd usbd sendmail. Initial rc.i386 initialization:. rc.i386 configuring syscons: blank_time screensaver moused. Additional ABI support: linux. Local package initialization:. Additional TCP options:. FreeBSD/i386 (k6-2.example.com) (ttyv0) login: rpratt Password: Generating the RSA and DSA keys may take some time on slower machines. This happens only on the initial boot-up of a new installation. Subsequent boots will be faster. If the X server has been configured and a Default Desktop chosen, it can be started by typing startx at the command line. Bootup of FreeBSD on the Alpha Alpha Once the install procedure has finished, you will be able to start FreeBSD by typing something like this to the SRM prompt: >>>BOOT DKC0 This instructs the firmware to boot the specified disk. To make FreeBSD boot automatically in the future, use these commands: >>> SET BOOT_OSFLAGS A >>> SET BOOT_FILE '' >>> SET BOOTDEF_DEV DKC0 >>> SET AUTO_ACTION BOOT The boot messages will be similar (but not identical) to those produced by FreeBSD booting on the &i386;. FreeBSD Shutdown It is important to properly shutdown the operating system. Do not just turn off power. First, become a superuser by typing su at the command line and entering the root password. This will work only if the user is a member of the wheel group. Otherwise, login as root and use shutdown -h now. The operating system has halted. Please press any key to reboot. It is safe to turn off the power after the shutdown command has been issued and the message Please press any key to reboot appears. If any key is pressed instead of turning off the power switch, the system will reboot. You could also use the Ctrl Alt Del key combination to reboot the system, however this is not recommended during normal operation. Supported Hardware hardware FreeBSD currently runs on a wide variety of ISA, VLB, EISA, and PCI bus-based PCs with Intel, AMD, Cyrix, or NexGen x86 processors, as well as a number of machines based on the Compaq Alpha processor. Support for generic IDE or ESDI drive configurations, various SCSI controllers, PCMCIA cards, USB devices, and network and serial cards is also provided. FreeBSD also supports IBM's microchannel (MCA) bus. A list of supported hardware is provided with each FreeBSD release in the FreeBSD Hardware Notes. This document can usually be found in a file named HARDWARE.TXT, in the top-level directory of a CDROM or FTP distribution or in sysinstall's documentation menu. It lists, for a given architecture, what hardware devices are known to be supported by each release of FreeBSD. Copies of the supported hardware list for various releases and architectures can also be found on the Release Information page of the FreeBSD Web site. Troubleshooting installation troubleshooting The following section covers basic installation troubleshooting, such as common problems people have reported. There are also a few questions and answers for people wishing to dual-boot FreeBSD with &ms-dos;. What to Do If Something Goes Wrong Due to various limitations of the PC architecture, it is impossible for probing to be 100% reliable, however, there are a few things you can do if it fails. Check the Hardware Notes document for your version of FreeBSD to make sure your hardware is supported. If your hardware is supported and you still experience lock-ups or other problems, reset your computer, and when the visual kernel configuration option is given, choose it. This will allow you to go through your hardware and supply information to the system about it. The kernel on the boot disks is configured assuming that most hardware devices are in their factory default configuration in terms of IRQs, IO addresses, and DMA channels. If your hardware has been reconfigured, you will most likely need to use the configuration editor to tell FreeBSD where to find things. It is also possible that a probe for a device not present will cause a later probe for another device that is present to fail. In that case, the probes for the conflicting driver(s) should be disabled. Some installation problems can be avoided or alleviated by updating the firmware on various hardware components, most notably the motherboard. The motherboard firmware may also be referred to as BIOS and most of the motherboard or computer manufactures have a website where the upgrades and upgrade information may be located. Most manufacturers strongly advise against upgrading the motherboard BIOS unless there is a good reason for doing so, which could possibly be a critical update of sorts. The upgrade process can go wrong, causing permanent damage to the BIOS chip. Do not disable any drivers you will need during the installation, such as your screen (sc0). If the installation wedges or fails mysteriously after leaving the configuration editor, you have probably removed or changed something you should not have. Reboot and try again. In configuration mode, you can: List the device drivers installed in the kernel. Disable device drivers for hardware that is not present in your system. Change IRQs, DRQs, and IO port addresses used by a device driver. After adjusting the kernel to match your hardware configuration, type Q to boot with the new settings. Once the installation has completed, any changes you made in the configuration mode will be permanent so you do not have to reconfigure every time you boot. It is still highly likely that you will eventually want to build a custom kernel. Dealing with Existing &ms-dos; Partitions DOS Many users wish to install &os; on PCs inhabited by µsoft; based operating systems. For those instances, &os; has a utility known as FIPS. This utility can be found in the tools directory on the install CD-ROM, or downloaded from one of various &os; mirrors. The FIPS utility allows you to split an existing &ms-dos; partition into two pieces, preserving the original partition and allowing you to install onto the second free piece. You first need to defragment your &ms-dos; partition using the &windows;; Disk Defragmenter utility (go into Explorer, right-click on the hard drive, and choose to defrag your hard drive), or use Norton Disk Tools. Now you can run the FIPS utility. It will prompt you for the rest of the information, just follow the on screen instructions. Afterwards, you can reboot and install &os; on the new free slice. See the Distributions menu for an estimate of how much free space you will need for the kind of installation you want. There is also a very useful product from PowerQuest (http://www.powerquest.com) called &partitionmagic;. This application has far more functionality than FIPS, and is highly recommended if you plan to add/remove operating systems often. It does cost money, so if you plan to install &os; and keep it installed, FIPS will probably be fine for you. Using &ms-dos; and &windows; File Systems At this time, &os; does not support file systems compressed with the Double Space™ application. Therefore the file system will need to be uncompressed before &os; can access the data. This can be done by running the Compression Agent located in the Start> Programs > System Tools menu. &os; can support &ms-dos; based file systems. This requires you use the &man.mount.msdos.8; command (in &os; 5.X, the command is &man.mount.msdosfs.8;) with the required parameters. The utilities most common usage is: &prompt.root; mount_msdos /dev/ad0s1 /mnt In this example, the &ms-dos; file system is located on the first partition of the primary hard disk. Your situation may be different, check the output from the dmesg, and mount commands. They should produce enough information too give an idea of the partition layout. Extended &ms-dos; file systems are usually mapped after the &os; partitions. In other words, the slice number may be higher than the ones &os; is using. For instance, the first &ms-dos; partition may be /dev/ad0s1, the &os; partition may be /dev/ad0s2, with the extended &ms-dos; partition being located on /dev/ad0s3. To some, this can be confusing at first. NTFS partitions can also be mounted in a similar manner using the &man.mount.ntfs.8; command. Alpha User's Questions and Answers Alpha This section answers some commonly asked questions about installing FreeBSD on Alpha systems. Can I boot from the ARC or Alpha BIOS Console? ARC Alpha BIOS SRM No. &os;, like Compaq Tru64 and VMS, will only boot from the SRM console. Help, I have no space! Do I need to delete everything first? Unfortunately, yes. Can I mount my Compaq Tru64 or VMS filesystems? No, not at this time. Valentino Vaschetto Contributed by Advanced Installation Guide This section describes how to install FreeBSD in exceptional cases. Installing FreeBSD on a System without a Monitor or Keyboard installation headless (serial console) serial console This type of installation is called a headless install, because the machine that you are trying to install FreeBSD on either does not have a monitor attached to it, or does not even have a VGA output. How is this possible you ask? Using a serial console. A serial console is basically using another machine to act as the main display and keyboard for a system. To do this, just follow the steps to create installation floppies, explained in . To modify these floppies to boot into a serial console, follow these steps: Enabling the Boot Floppies to Boot into a Serial Console mount If you were to boot into the floppies that you just made, FreeBSD would boot into its normal install mode. We want FreeBSD to boot into a serial console for our install. To do this, you have to mount the kern.flp floppy onto your FreeBSD system using the &man.mount.8; command. &prompt.root; mount /dev/fd0 /mnt Now that you have the floppy mounted, you must - change into the /mnt directory: + change into the /mnt directory: &prompt.root; cd /mnt Here is where you must set the floppy to boot into a serial console. You have to make a file called boot.config containing /boot/loader -h. All this does is pass a flag to the bootloader to boot into a serial console. &prompt.root; echo "/boot/loader -h" > boot.config Now that you have your floppy configured correctly, you must unmount the floppy using the &man.umount.8; command: &prompt.root; cd / &prompt.root; umount /mnt Now you can remove the floppy from the floppy drive. Connecting Your Null Modem Cable null modem cable You now need to connect a null modem cable between the two machines. Just connect the cable to the serial ports of the 2 machines. A normal serial cable will not work here, you need a null modem cable because it has some of the wires inside crossed over. Booting Up for the Install It is now time to go ahead and start the install. Put the kern.flp floppy in the floppy drive of the machine you are doing the headless install on, and power on the machine. Connecting to Your Headless Machine cu Now you have to connect to that machine with &man.cu.1;: &prompt.root; cu -l /dev/cuaa0 That's it! You should now be able to control the headless machine through your cu session. It will ask you to put in the mfsroot.flp, and then it will come up with a selection of what kind of terminal to use. Select the FreeBSD color console and proceed with your install! Preparing Your Own Installation Media To prevent repetition, FreeBSD disk in this context means a FreeBSD CDROM or DVD that you have purchased or produced yourself. There may be some situations in which you need to create your own FreeBSD installation media and/or source. This might be physical media, such as a tape, or a source that sysinstall can use to retrieve the files, such as a local FTP site, or an &ms-dos; partition. For example: You have many machines connected to your local network, and one FreeBSD disk. You want to create a local FTP site using the contents of the FreeBSD disk, and then have your machines use this local FTP site instead of needing to connect to the Internet. You have a FreeBSD disk, and FreeBSD does not recognize your CD/DVD drive, but &ms-dos;/&windows; does. You want to copy the FreeBSD installations files to a DOS partition on the same computer, and then install FreeBSD using those files. The computer you want to install on does not have a CD/DVD drive or a network card, but you can connect a Laplink-style serial or parallel cable to a computer that does. You want to create a tape that can be used to install FreeBSD. Creating an Installation CDROM As part of each release, the FreeBSD project makes available two CDROM images (ISO images). These images can be written (burned) to CDs if you have a CD writer, and then used to install FreeBSD. If you have a CD writer, and bandwidth is cheap, then this is the easiest way to install FreeBSD. Download the Correct ISO Images The ISO images for each release can be downloaded from ftp://ftp.FreeBSD.org/pub/FreeBSD/ISO-IMAGES-arch/version or the closest mirror. Substitute arch and version as appropriate. That directory will normally contain the following images: FreeBSD ISO Image Names and Meanings Filename Contains version-mini.iso Everything you need to install FreeBSD. version-disc1.iso Everything you need to install FreeBSD, and as many additional third party packages as would fit on the disc. version-disc2.iso A live filesystem, which is used in conjunction with the Repair facility in sysinstall. A copy of the FreeBSD CVS tree. As many additional third party packages as would fit on the disc.
You must download one of either the mini ISO image, or the image of disc one. Do not download both of them, since the disc one image contains everything that the mini ISO image contains. Use the mini ISO if Internet access is cheap for you. It will let you install FreeBSD, and you can then install third party packages by downloading them using the ports/packages system (see ) as necessary. Use the image of disc one if you want a reasonable selection of third party packages on the disc as well. The additional disc images are useful, but not essential, especially if you have high-speed access to the Internet. Write the CDs You must then write the CD images to disc. If you will be doing this on another FreeBSD system then see for more information (in particular, and ). If you will be doing this on another platform then you will need to use whatever utilities exist to control your CD writer on that platform. The images provided are in the standard ISO format, which many CD writing applications support. Creating a Local FTP Site with a FreeBSD Disk installation network FTP FreeBSD disks are laid out in the same way as the FTP site. This makes it very easy for you to create a local FTP site that can be used by other machines on your network when installing FreeBSD. On the FreeBSD computer that will host the FTP site, ensure that the CDROM is in the drive, and mounted on /cdrom. &prompt.root; mount /cdrom Create an account for anonymous FTP in /etc/passwd. Do this by editing /etc/passwd using &man.vipw.8; and adding this line: ftp:*:99:99::0:0:FTP:/cdrom:/nonexistent Ensure that the FTP service is enabled in /etc/inetd.conf. Anyone with network connectivity to your machine can now chose a media type of FTP and type in ftp://your machine after picking Other in the FTP sites menu during the install. This approach is OK for a machine that is on your local network, and that is protected by your firewall. Offering up FTP services to other machines over the Internet (and not your local network) exposes your computer to the attention of crackers and other undesirables. We strongly recommend that you follow good security practices if you do this. Creating Installation Floppies installation floppies If you must install from floppy disk (which we suggest you do not do), either due to unsupported hardware or simply because you insist on doing things the hard way, you must first prepare some floppies for the installation. At a minimum, you will need as many 1.44 MB or 1.2 MB floppies as it takes to hold all the files in the bin (binary distribution) directory. If you are preparing the floppies from DOS, then they must be formatted using the &ms-dos; FORMAT command. If you are using &windows;, use Explorer to format the disks (right-click on the A: drive, and select Format. Do not trust factory pre-formatted floppies. Format them again yourself, just to be sure. Many problems reported by our users in the past have resulted from the use of improperly formatted media, which is why we are making a point of it now. If you are creating the floppies on another FreeBSD machine, a format is still not a bad idea, though you do not need to put a DOS filesystem on each floppy. You can use the disklabel and newfs commands to put a UFS filesystem on them instead, as the following sequence of commands (for a 3.5" 1.44 MB floppy) illustrates: &prompt.root; fdformat -f 1440 fd0.1440 &prompt.root; disklabel -w -r fd0.1440 floppy3 &prompt.root; newfs -t 2 -u 18 -l 1 -i 65536 /dev/fd0 Use fd0.1200 and floppy5 for 5.25" 1.2 MB disks. Then you can mount and write to them like any other filesystem. After you have formatted the floppies, you will need to copy the files to them. The distribution files are split into chunks conveniently sized so that five of them will fit on a conventional 1.44 MB floppy. Go through all your floppies, packing as many files as will fit on each one, until you have all of the distributions you want packed up in this fashion. Each distribution should go into a subdirectory on the floppy, e.g.: a:\bin\bin.aa, a:\bin\bin.ab, and so on. Once you come to the Media screen during the install process, select Floppy and you will be prompted for the rest. Installing from an &ms-dos; Partition installation from MS-DOS To prepare for an installation from an &ms-dos; partition, copy the files from the distribution into a directory called freebsd in the root directory of the partition. For example, c:\freebsd. The directory structure of the CDROM or FTP site must be partially reproduced within this directory, so we suggest using the DOS xcopy command if you are copying it from a CD. For example, to prepare for a minimal installation of FreeBSD: C:\> md c:\freebsd C:\> xcopy e:\bin c:\freebsd\bin\ /s C:\> xcopy e:\manpages c:\freebsd\manpages\ /s Assuming that C: is where you have free space and E: is where your CDROM is mounted. If you do not have a CDROM drive, you can download the distribution from ftp.FreeBSD.org. Each distribution is in its own directory; for example, the base distribution can be found in the &rel.current;/base/ directory. In the 4.X and older releases of &os; the base distribution is called bin. Adjust the sample commands and URLs above accordingly, if you are using one of these versions. For as many distributions you wish to install from an &ms-dos; partition (and you have the free space for), install each one under c:\freebsd — the BIN distribution is the only one required for a minimum installation. Creating an Installation Tape installation from QIC/SCSI Tape Installing from tape is probably the easiest method, short of an online FTP install or CDROM install. The installation program expects the files to be simply tarred onto the tape. After getting all of the distribution files you are interested in, simply tar them onto the tape: &prompt.root; cd /freebsd/distdir &prompt.root; tar cvf /dev/rwt0 dist1 ... dist2 When you perform the installation, you should make sure that you leave enough room in some temporary directory (which you will be allowed to choose) to accommodate the full contents of the tape you have created. Due to the non-random access nature of tapes, this method of installation requires quite a bit of temporary storage. When starting the installation, the tape must be in the drive before booting from the boot floppy. The installation probe may otherwise fail to find it. Before Installing over a Network installation network serial (SLIP or PPP) installation network parallel (PLIP) installation network Ethernet There are three types of network installations available. Serial port (SLIP or PPP), Parallel port (PLIP (laplink cable)), or Ethernet (a standard Ethernet controller (includes some PCMCIA)). The SLIP support is rather primitive, and limited primarily to hard-wired links, such as a serial cable running between a laptop computer and another computer. The link should be hard-wired as the SLIP installation does not currently offer a dialing capability; that facility is provided with the PPP utility, which should be used in preference to SLIP whenever possible. If you are using a modem, then PPP is almost certainly your only choice. Make sure that you have your service provider's information handy as you will need to know it fairly early in the installation process. If you use PAP or CHAP to connect your ISP (in other words, if you can connect to the ISP in &windows; without using a script), then all you will need to do is type in dial at the ppp prompt. Otherwise, you will need to know how to dial your ISP using the AT commands specific to your modem, as the PPP dialer provides only a very simple terminal emulator. Please refer to the user-ppp handbook and FAQ entries for further information. If you have problems, logging can be directed to the screen using the command set log local .... If a hard-wired connection to another FreeBSD (2.0-R or later) machine is available, you might also consider installing over a laplink parallel port cable. The data rate over the parallel port is much higher than what is typically possible over a serial line (up to 50 kbytes/sec), thus resulting in a quicker installation. Finally, for the fastest possible network installation, an Ethernet adapter is always a good choice! FreeBSD supports most common PC Ethernet cards; a table of supported cards (and their required settings) is provided in the Hardware Notes for each release of FreeBSD. If you are using one of the supported PCMCIA Ethernet cards, also be sure that it is plugged in before the laptop is powered on! FreeBSD does not, unfortunately, currently support hot insertion of PCMCIA cards during installation. You will also need to know your IP address on the network, the netmask value for your address class, and the name of your machine. If you are installing over a PPP connection and do not have a static IP, fear not, the IP address can be dynamically assigned by your ISP. Your system administrator can tell you which values to use for your particular network setup. If you will be referring to other hosts by name rather than IP address, you will also need a name server and possibly the address of a gateway (if you are using PPP, it is your provider's IP address) to use in talking to it. If you want to install by FTP via a HTTP proxy, you will also need the proxy's address. If you do not know the answers to all or most of these questions, then you should really probably talk to your system administrator or ISP before trying this type of installation. Before Installing via NFS installation network NFS The NFS installation is fairly straight-forward. Simply copy the FreeBSD distribution files you want onto an NFS server and then point the NFS media selection at it. If this server supports only privileged port (as is generally the default for Sun workstations), you will need to set the option in the Options menu before installation can proceed. If you have a poor quality Ethernet card which suffers from very slow transfer rates, you may also wish to toggle the flag. In order for NFS installation to work, the server must support subdir mounts, for example, if your FreeBSD &rel.current; distribution directory lives on: ziggy:/usr/archive/stuff/FreeBSD, then ziggy will have to allow the direct mounting of /usr/archive/stuff/FreeBSD, not just /usr or /usr/archive/stuff. In FreeBSD's /etc/exports file, this is controlled by the options. Other NFS servers may have different conventions. If you are getting permission denied messages from the server, then it is likely that you do not have this enabled properly. diff --git a/en_US.ISO8859-1/books/handbook/mac/chapter.sgml b/en_US.ISO8859-1/books/handbook/mac/chapter.sgml index c381f5d9b5..6ccbc899a1 100644 --- a/en_US.ISO8859-1/books/handbook/mac/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/mac/chapter.sgml @@ -1,2211 +1,2211 @@ Tom Rhodes Written by Mandatory Access Control Synopsis MAC Mandatory Access Control &os; 5.X introduced new security extensions from the TrustedBSD project based on the &posix;.1e draft. Two of the most significant new security mechanisms are file system Access Control Lists (ACLs) and Mandatory Access Control (MAC) facilities. Mandatory Access Control allows new access control modules to be loaded, implementing new security policies. Some provide protections of a narrow subset of the system, hardening a particular service, while others provide comprehensive labeled security across all subjects and objects. The mandatory part of the definition comes from the fact that the enforcement of the controls is done by administrators and the system, and is not left up to the discretion of users as is done with discretionary access control (DAC, the standard file and System V IPC permissions on &os;). This chapter will focus on the Mandatory Access Control Framework (MAC Framework), and a set of pluggable policy modules implementing various security policies. After reading this chapter, you will know: What MAC modules are currently included in &os; and their associated policies. What MAC policies are capable of implementing, the difference between a label and non-labeled policy. How to efficiently configure a system to use the MAC framework. How to configure the different policies used by the MAC modules. How to implement a more secure environment using the MAC framework and the examples shown. How to test the MAC configuration to ensure the framework has been properly implemented. Before reading this chapter, you should: Understand &unix; and &os; basics (). Be familiar with the basics of kernel configuration/compilation (). Have some familiarity with security and how it pertains to &os; (). The improper use of the information in this chapter may cause loss of access to the system, aggravation of users, or inability to access the features provided by &xfree86;. More importantly, MAC should not be relied upon to completely secure a system. The MAC framework only augments existing security policy; without sound security practices and regular security checks, the system will never be completely secure. It should also be noted that the examples contained within this chapter are just that, examples. It is not recommended that these particular settings be rolled out on a production system. Implementing these policies takes a good deal of thought. One who does not fully understand exactly how everything works may find him or herself going back through the entire system and reconfiguring many files or directories. What Will Not Be Covered This chapter covers a broad range of security issues relating to the MAC framework; however, the development of new MAC policies will not be covered. A number of modules included with the MAC framework have specific characteristics which are provided for both testing and new module development. These include the &man.mac.test.4;, &man.mac.stub.4; and &man.mac.none.4; modules/policies. For more information on these modules and the various mechanisms they provide, please review the manual pages. Key Terms in this Chapter Before reading this chapter, a few key terms must be explained. This will hopefully clear up any confusion that may occur and avoid the abrupt introduction of new terms and information. compartment: A compartment is a a set of programs and data to be partitioned or separated, where users are given explicit access to specific components of a system. Also, a compartment represents a grouping, such as a work group, department, project, or topic. Using compartments, it is possible to implement a need-to-know policy. integrity: Integrity, as a key concept, is the level of trust which can be placed on data. As the integrity of the data is elevated, so does the ability to trust that data. label: A label is a security attribute which can be applied to files, directories, or other items in the system. It could be considered to be a confidentiality stamp; when a label is placed on a file it describes the security properties for that specific file and will only permit access by files, users, resources, etc. with a similar security setting. The meaning and interpretation of label values depends on the policy: while some policies might treat a label as representing the integrity or secrecy of an object, other policies might use labels to hold rules for access. level: The increased or decreased setting of a security attribute. As the level increases, its security is considered to elevate as well. multilabel: The property is a file system option which can be set in single user mode using the &man.tunefs.8; utility; set during the boot operation using the &man.fstab.5; file; or during the creation of a new file system. This option will permit an administrator to apply different MAC labels on different objects. This option only applies to labeled policies. object: An object or system object is an entity through which information flows under the direction of a subject. This includes directories, files, fields, screens, keyboards, memory, magnetic storage, printers or any other data storage/moving device. Basically, an object is a data container or a system resource; access to an object effectively means access to the data. policy: A collection of rules which defines how objectives are to be achieved. A policy usually documents how certain items are to be handled. This chapter will consider the term policy in this context as a security policy; i.e. a collection of rules which will control the flow of data and information and define whom will have access to that data and information. sensitivity: Usually used when discussing MLS. A sensitivity level is a term used to describe how important or secret the data should be. As the sensitivity level increases, so does the importance of the data. single label: A single label is when the entire file system uses one label to enforce access control over the flow of data. When a file system has this set, which is any time when the option is not set, all files will conform to the same label setting. subject: a subject is any active entity that causes information to flow between objects; e.g. a user, user processor, system process, etc. On &os;, this is almost always a thread acting in a process on behalf of a user. Explanation of MAC With all of these new terms in mind, consider how the MAC framework augments the security of the system as a whole. The various security policies provided by the MAC framework could be used to protect the network and file systems, block users from accessing certain ports and sockets, and more. Perhaps the best use of the policies is to blend them together, by loading several security policy modules at a time, for a multi-layered security environment. In a multi-layered security environment, multiple policies are in effect to keep security in check. This is different then a hardening policy, which typically hardens elements of a system that is used only for specific purposes. The only downside is administrative overhead in cases of multiple file system labels, setting network access control user by user, etc. These downsides are minimal when compared to the lasting effect of the framework; for instance, the ability to pick choose which policies are required for a specific configuration keeps performance overhead down. The reduction of support for unneeded policies can increase the overall performance of the system as well as offer flexibility of choice. A good implementation would consider the overall security requirements and effectively implement the various policies offered by the framework. Thus a system utilizing MAC features should at least guarantee that a user will not be permitted to change security attributes at will; all user utilities, programs and scripts must work within the constraints of the access rules provided by the selected policies; and that total control of the MAC access rules are in the hands of the system administrator. It is the sole duty of the system administrator to carefully select the correct policies. Some environments may need to limit access control over the network; in these cases, the &man.mac.portacl.4;, &man.mac.ifoff.4; and even &man.mac.biba.4; policies might make good starting points. In other cases, strict confidentiality of file system objects might be required. Policies such as &man.mac.bsdextended.4; and &man.mac.mls.4; exist for this purpose. Policy decisions could be made based on network configuration. Perhaps only certain users should be permitted access to facilities provided by &man.ssh.1; to access the network or the Internet. The &man.mac.portacl.4; would be the policy of choice for these situations. But what should be done in the case of file systems? Should all access to certain directories be severed from other groups or specific users? Or should we limit user or utility access to specific files by setting certain objects as classified? In the file system case, access to objects might be considered confidential to some users but not to others. For an example, a large development team might be broken off into smaller groups of individuals. Developers in project A might not be permitted to access objects written by developers in project B. Yet they might need to access objects created by developers in project C; that is quite a situation indeed. Using the different policies provided by the MAC framework; users could be divided into these groups and then given access to the appropriate areas without the fear of information leakage. Thus, each policy has a unique way of dealing with the overall security of a system. Policy selection should be based on a well thought out security policy. In many cases, the overall policy may need to be revised and reimplemented on the system. Understanding the different policies offered by the MAC framework will help administrators choose the best policies for their situations. The default &os; kernel does not include the option for the MAC framework; thus the following kernel option must be added before trying any of the examples or information in this chapter: options MAC And the kernel will require a rebuild and a reinstall. While the various manual pages for MAC modules state that they may be built into the kernel, it is possible to lock the system out of the network and more. Implementing MAC is much like implementing a firewall, but care must be taken to prevent being completely locked out of the system. The ability to revert back to a previous configuration should be considered while the implementation of MAC remotely should be done with extreme caution. Understanding MAC Labels A MAC label is a security attribute which may be applied to subjects and objects throughout the system. When setting a label, the user must be able to comprehend what it is, exactly, that is being done. The attributes available on an object depend on the policy loaded, and that policies interpret their attributes in pretty different ways. If improperly configured due to lack of comprehension, or the inability to understand the implications, the result will be the unexpected and perhaps, undesired, behavior of the system. The security label on an object is used as a part of a security access control decision by a policy. With some policies, the label by itself contains all information necessary to make a decision; in other models, the labels may be processed as part of a larger rule set, etc. For instance, setting the label of biba/low on a file will represent a label maintained by the Biba policy, with a value of low. A few policies which support the labeling feature in &os; offers three specific predefined labels. These are the low, high, and equal labels. Although they enforce access control in a different manner with each policy, you can be sure that the low label will be the lowest setting, the equal label will set the subject or object to be disabled or unaffected, and the high label will enforce the highest setting available in the Biba and MLS policies. Within single label file system environments, only one label may be used on objects. This will enforce one set of access permissions across the entire system and in many environments may be all that is required. There are a few cases; however, where multiple labels may be set on objects or subjects in the file system. For those cases, the option may be passed to &man.tunefs.8;. In the case of Biba and MLS, a numeric label may be set to indicate the precise level of hierarchical control. This numeric level is used to partition or sort information into different groups of say, classification only permitting access to that group or a higher group level. In most cases the administrator will only be setting up a single label to use throughout the file system. Hey wait, this is similar to DAC! I thought MAC gave control strictly to the administrator. That statement still holds true, to some extent root is the one in control and who configures the policy so that users are placed in the appropriate categories/access levels. Alas, many policies can restrict the root user as well. Basic control over objects will then be released to the group but root may revoke or modify the settings at any time. This is the hierarchal/clearance model covered by policies such as Biba and MLS. Label Configuration Virtually all aspects of label policy configuration will be performed using the base system utilities. These commands provide a simple interface for object or subject configuration or the manipulation and verification of the configuration. All configuration may be done by use of the &man.setfmac.8; and &man.setpmac.8; utilities. The setfmac command is used to set MAC labels on system objects while the setpmac command is used to set the labels on system subjects. Observe: &prompt.root; setfmac biba/high test If no errors occurred with the command above, a prompt will be returned. The only time these commands are not quiescent is when an error occurred; similarly to the &man.chmod.1; and &man.chown.8; commands. In some cases this error may be a Permission denied and is usually obtained when the label is being set or modified on an object which is restricted.Other conditions may produce different failures. For instance, the file may not be owned by the user attempting to relabel the object, the object may not exist or may be read only. A mandatory policy will not allow the process to relabel the file, maybe because of a property of the file, a property of the process, or a property of the proposed new label value. For example: a user running at low integrity tries to change the label of a high integrity file. Or perhaps a user running at low integrity tries to change the label of a low integrity file to a high integrity label. The system administrator may use the following commands to overcome this: &prompt.root; setfmac biba/high test Permission denied &prompt.root; setpmac biba/low setfmac biba/high test &prompt.root; getfmac test test: biba/high As we see above, setpmac can be used to override the policy's settings by assigning a different label to the invoked process. The getpmac utility is usually used with currently running processes, such as sendmail: although it takes a process ID in place of a command the logic is extremely similar. If users attempt to manipulate a file not in their access, subject to the rules of the loaded policies, the Operation not permitted error will be displayed by the mac_set_link function. Users and Label Settings Users themselves are required to have labels so that their files and processes may properly interact with the security policy defined on the system. This is configured through the login.conf file by use of login classes. Every policy that uses labels will implement the user class setting. An example entry containing every policy is listed below: default:\ :copyright=/etc/COPYRIGHT:\ :welcome=/etc/motd:\ :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\ :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:\ :manpath=/usr/share/man /usr/local/man:\ :nologin=/usr/sbin/nologin:\ :cputime=1h30m:\ :datasize=8M:\ :vmemoryuse=100M:\ :stacksize=2M:\ :memorylocked=4M:\ :memoryuse=8M:\ :filesize=8M:\ :coredumpsize=8M:\ :openfiles=24:\ :maxproc=32:\ :priority=0:\ :requirehome:\ :passwordtime=91d:\ :umask=022:\ :ignoretime@:\ :label=partition/13,mls/5,biba/10(5-15),lomac10[2]: The label option is used to set the user class default label which will be enforced by MAC. Users will never be permitted to modify this value, thus it can be considered not optional in the user case. In a real configuration, however, the administrator will never wish to enable every policy. It is recommended that the rest of this chapter be reviewed before any of this configuration is implemented. Users may change their label after the initial login; however, this change is subject constraints of the policy. The example above tells the Biba policy that a process's minimum integrity is 5, its maximum is 15, but the default effective label is 10. The process will run at 10 until it chooses to change label, perhaps due to the user using the setpmac command, which will be constrained by Biba to the range set at login. In all cases, after a change to login.conf, the login class capability database must be rebuilt using cap_mkdb and this will be reflected throughout every forthcoming example or discussion. It is useful to note that many sites may have a particularly large number of users requiring several different user classes. In depth planning is required as this may get extremely difficult to manage. Future versions of &os; will include a new way to deal with mapping users to labels; however, this will not be available until some time after &os; 5.3. Network Interfaces and Label Settings Labels may also be set on network interfaces to help control the flow of data across the network. In all cases they function in the same way the policies function with respect to objects. Users at high settings in biba, for example, will not be permitted to access network interfaces with a label of low. The may be passed to ifconfig when setting the MAC label on network interfaces. For example: &prompt.root; ifconfig bge0 maclabel biba/equal will set the MAC label of biba/equal on the &man.bge.4; interface. When using a setting similar to biba/high(low-high) the entire label should be quoted; otherwise an error will be returned. Each policy which supports labeling has some tunable which may be used to disable the MAC label on network interfaces. Setting the label to will have a similar effect. Review the output from sysctl, the policy manual pages, or even the information found later in this chapter for those tunables. Singlelabel or Multilabel? By default the system will use the option. But what does this mean to the administrator? There are several differences which, in their own right, offer pros and cons to the flexibility in the systems security model. The only permits for one label, for instance biba/high to be used for each subject or object. It provides for lower administration overhead but decreases the flexibility of policies which support labeling. Many administrators may want to use the option in their security policy. The option will permit each subject or object to have its own independent MAC label in place of the standard option which will allow only one label throughout the partition. The and label options are only required for the policies which implement the labeling feature, including the Biba, Lomac, MLS and SEBSD policies. In many cases, the may not need to be set at all. Consider the following situation and security model: &os; web-server using the MAC framework and a mix of the various policies. This machine only requires one label, biba/high, for everything in the system. Here the file system would not require the option as a single label will always be in effect. But, this machine will be a web server and should have the web server run at biba/low to prevent write up capabilities. The Biba policy and how it works will be discussed later, so if the previous comment was difficult to interpret just continue reading and return. The server could use a separate partition set at biba/low for most if not all of its runtime state. Much is lacking from this example, for instance the restrictions on data, configuration and user settings; however, this is just a quick example to prove the aforementioned point. If any of the non-labeling policies are to be used, then the option would never be required. These include the seeotheruids, portacl and partition policies. It should also be noted that using with a partition and establishing a security model based on functionality could open the doors for higher administrative overhead as everything in the file system would have a label. This includes directories, files, and even device nodes. The following command will set on the file systems to have multiple labels. This may only be done in single user mode: &prompt.root; tunefs -l enable / This is not a requirement for the swap file system. Some users have experienced problems with setting the flag on the root partition. If this is the case, please review the of this chapter. Controlling MAC with Tunables Without any modules loaded, there are still some parts of MAC which may be configured using the sysctl interface. These tunables are described below and in all cases the number one (1) means enabled while the number zero (0) means disabled: security.mac.enforce_fs defaults to one (1) and enforces MAC file system policies on the file systems. security.mac.enforce_kld defaults to one (1) and enforces MAC kernel linking policies on the dynamic kernel linker (see &man.kld.4;). security.mac.enforce_network defaults to one (1) and enforces MAC network policies. security.mac.enforce_pipe defaults to one (1) and enforces MAC policies on pipes. security.mac.enforce_process defaults to one (1) and enforces MAC policies on processes which utilize inter-process communication. security.mac.enforce_socket defaults to one (1) and enforces MAC policies on sockets (see the &man.socket.2; manual page). security.mac.enforce_system defaults to one (1) and enforces MAC policies on system activities such as accounting and rebooting. security.mac.enforce_vm defaults to one (1) and enforces MAC policies on the virtual memory system. Every policy or MAC option supports tunables. These usually hang off of the security.mac.<policyname> tree. To view all of the tunables from MAC use the following command: &prompt.root; sysctl -da | grep mac This should be interpreted as all of the basic MAC policies are enforced by default. If the modules were built into the kernel the system would be extremely locked down and most likely unable to communicate with the local network or connect to the Internet, etc. This is why building the modules into the kernel is not completely recommended. Not because it limits the ability to disable features on the fly with sysctl, but it permits the administrator to instantly switch the policies of a system without the requirement of rebuilding and reinstalling a new system. Module Configuration Every module included with the MAC framework may be either compiled into the kernel as noted above or loaded as a run-time kernel module. The recommended method is to add the module name to the /boot/loader.conf file so that it will load during the initial boot operation. The following sections will discuss the various MAC modules and cover their features. Implementing them into a specific environment will also be a consideration of this chapter. Some modules support the use of labeling, which is controlling access by enforcing a label such as this is allowed and this is not. A label configuration file may control how files may be accessed, network communication can be exchanged, and more. The previous section showed how the flag could be set on file systems to enable per-file or per-partition access control. A single label configuration would enforce only one label across the system, that is why the tunefs option is called . The MAC seeotheruids Module MAC See Other UIDs Policy Module name: mac_seeotheruids.ko Kernel configuration line: options MAC_SEEOTHERUIDS Boot option: mac_seeotheruids_load="YES" The &man.mac.seeotheruids.4; module mimics and extends the security.bsd.see_other_uids and security.bsd.see_other_gids sysctl tunables. This option does not require any labels to be set before configuration and can operate transparently with the other modules. After loading the module, the following sysctl tunables may be used to control the features: security.mac.seeotheruids.enabled will enable the module's features and use the default settings. These default settings will deny users the ability to view processes and sockets owned by other users. security.mac.seeotheruids.specificgid_enabled will allow a certain group to be exempt from this policy. To exempt specific groups from this policy, use the security.mac.seeotheruids.specificgid=XXX sysctl tunable. In the above example, the XXX should be replaced with the numeric group ID to be exempted. security.mac.seeotheruids.primarygroup_enabled is used to exempt specific primary groups from this policy. When using this tunable, the security.mac.seeotheruids.specificgid_enabled may not be set. It should be noted that the root user is not exempt from this policy. This is one of the large differences between the MAC version and the standard tunable version included by default: security.bsd.seeotheruids. The MAC bsdextended Module MAC File System Firewall Policy Module name: mac_bsdextended.ko Kernel configuration line: options MAC_BSDEXTENDED Boot option: mac_bsdextended_load="YES" The &man.mac.bsdextended.4; module enforces the file system firewall. This module's policy provides an extension to the standard file system permissions model, permitting an administrator to create a firewall-like ruleset to protect files, utilities, and directories in the file system hierarchy. The policy may be created using a utility, &man.ugidfw.8;, that has a syntax similar to that of &man.ipfw.8;. More tools can be written by using the functions in the &man.libugidfw.3; library. Extreme caution should be taken when working with this module; incorrect use could block access to certain parts of the file system. Examples After the &man.mac.bsdextended.4; module has been loaded, the following command may be used to list the current rule configuration: &prompt.root; ugidfw list 0 slots, 0 rules As expected, there are no rules defined. This means that everything is still completely accessible. To create a rule which will block all access by users but leave root unaffected, simply run the following command: &prompt.root; ugidfw add subject not uid root new object not uid root mode n In releases prior to &os; 5.3, the add parameter did not exist. In those cases the set should be used instead. See below for a command example. This is a very bad idea as it will block all users from issuing even the most simple commands, such as ls. A more patriotic list of rules might be: &prompt.root; ugidfw set 2 subject uid user1 object uid user2 mode n &prompt.root; ugidfw set 3 subject uid user1 object gid user2 mode n This will block any and all access, including directory listings, to user2's home directory from the username user1. In place of user1, the could be passed. This will enforce the same access restrictions above for all users in place of just one user. The root user will be unaffected by these changes. This should give a general idea of how the &man.mac.bsdextended.4; module may be used to help fortify a file system. For more information, see the &man.mac.bsdextended.4; and the &man.ugidfw.8; manual pages. The MAC ifoff Module MAC Interface Silencing Policy Module name: mac_ifoff.ko Kernel configuration line: options MAC_IFOFF Boot option: mac_ifoff_load="YES" The &man.mac.ifoff.4; module exists solely to disable network interfaces on the fly and keep network interfaces from being brought up during the initial system boot. It does not require any labels to be set up on the system, nor does it have a dependency on other MAC modules. Most of the control is done through the sysctl tunables listed below. security.mac.ifoff.lo_enabled will enable/disable all traffic on the loopback (&man.lo.4;) interface. security.mac.ifoff.bpfrecv_enabled will enable/disable all traffic on the Berkeley Packet Filter interface (&man.bpf.4;) security.mac.ifoff.other_enabled will enable/disable traffic on all other interfaces. One of the most common uses of &man.mac.ifoff.4; is network monitoring in an environment where network traffic should not be permitted during the boot sequence. Another suggested use would be to write a script which uses security/aide to automatically block network traffic if it finds new or altered files in protected directories. The MAC portacl Module MAC Port Access Control List Policy Module name: mac_portacl.ko Kernel configuration line: MAC_PORTACL Boot option: mac_portacl_load="YES" The &man.mac.portacl.4; module is used to limit binding to local TCP and UDP ports using a variety of sysctl variables. In essence &man.mac.portacl.4; makes it possible to allow non-root users to bind to specified privileged ports, i.e. ports fewer than 1024. Once loaded, this module will enable the MAC policy on all sockets. The following tunables are available: security.mac.portacl.enabled will enable/disable the policy completely.Due to a bug the security.mac.portacl.enabled sysctl variable will not work on &os; 5.2.1 or previous releases. security.mac.portacl.port_high will set the highest port number that &man.mac.portacl.4; will enable protection for. security.mac.portacl.suser_exempt will, when set to a non-zero value, exempt the root user from this policy. security.mac.portacl.rules will specify the actual mac_portacl policy; see below. The actual mac_portacl policy, as specified in the security.mac.portacl.rules sysctl, is a text string of the form: rule[,rule,...] with as many rules as needed. Each rule is of the form: idtype:id:protocol:port. The idtype parameter can be uid or gid and used to interpret the id parameter as either a user id or group id, respectively. The protocol parameter is used to determine if the rule should apply to TCP or UDP by setting the parameter to tcp or udp. The final port parameter is the port number to allow the specified user or group to bind to. Since the ruleset is interpreted directly by the kernel only numeric values can be used for the user ID, group ID, and port parameters. I.e. user, group, and port service names cannot be used. By default, on &unix;-like systems, ports fewer than 1024 can only be used by/bound to privileged processes, i.e. those run as root. For &man.mac.portacl.4; to allow non-privileged processes to bind to ports below 1024 this standard &unix; restriction has to be disabled. This can be accomplished by setting the &man.sysctl.8; variables net.inet.ip.portrange.reservedlow and net.inet.ip.portrange.reservedhigh to zero. See the examples below or review the &man.mac.portacl.4; manual page for further information. Examples The following examples should illuminate the above discussion a little better: &prompt.root; sysctl security.mac.portacl.port_high=1023 &prompt.root; sysctl net.inet.ip.portrange.reservedlow=0 net.inet.ip.portrange.reservedhigh=0 First we set &man.mac.portacl.4; to cover the standard privileged ports and disable the normal &unix; bind restrictions. &prompt.root; sysctl security.mac.portacl.suser_exempt=1 The root user should not be crippled by this policy, thus set the security.mac.portacl.suser_exempt to a non-zero value. The &man.mac.portacl.4; module has now been set up to behave the same way &unix;-like systems behave by default. &prompt.root; sysctl security.mac.portacl.rules=uid:80:tcp:80 Allow the user with UID 80 (normally the www user) to bind to port 80. This can be used to allow the www user to run a web server without ever having root privilege. &prompt.root; sysctl security.mac.portacl.rules=uid:1001:tcp:110,uid:1001:tcp:995 Permit the user with the UID of 1001 to bind to the TCP ports 110 (pop3) and 995 (pop3s). This will permit this user to start a server that accepts connections on ports 110 and 995. MAC Policies with Labeling Features The next few sections will discuss MAC policies which use labels. From here on this chapter will focus on the features of &man.mac.biba.4;, &man.mac.lomac.4;, &man.mac.partition.4;, and &man.mac.mls.4;. This is an example configuration only and should not be considered for a production implementation. The goal is to document and show the syntax as well as examples for implementation and testing. For these policies to work correctly several preparations must be made. Preparation for Labeling Policies The following changes are required in the login.conf file: An insecure class, or another class of similar type, must be added. The login class of insecure is not required and just used as an example here; different configurations may use another class name. The insecure class should have the following settings and definitions. Several of these can be altered but the line which defines the default label is a requirement and must remain. insecure:\ :copyright=/etc/COPYRIGHT:\ :welcome=/etc/motd:\ :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\ :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:\ :manpath=/usr/share/man /usr/local/man:\ :nologin=/usr/sbin/nologin:\ :cputime=1h30m:\ :datasize=8M:\ :vmemoryuse=100M:\ :stacksize=2M:\ :memorylocked=4M:\ :memoryuse=8M:\ :filesize=8M:\ :coredumpsize=8M:\ :openfiles=24:\ :maxproc=32:\ :priority=0:\ :requirehome:\ :passwordtime=91d:\ :umask=022:\ :ignoretime@:\ :label=partition/13,mls/5,biba/low: The &man.cap.mkdb.1; command needs to be ran on &man.login.conf.5; before any of the users can be switched over to the new class. The root should also be placed into a login class; otherwise, almost every command executed by root will require the use of setpmac. Rebuilding the login.conf database may cause some errors later with the daemon class. Simply uncommenting the daemon account and rebuilding the database should alleviate these issues. Ensure that all partitions on which MAC labeling will be implemented support the . We must do this because many of the examples here contain different labels for testing purposes. Review the output from the mount command as a precautionary measure. Switch any users who will have the higher security mechanisms enforced over to the new user class. A quick run of &man.pw.8; or &man.vipw.8; should do the trick. The MAC partition Module MAC Process Partition Policy Module name: mac_partition.ko Kernel configuration line: options MAC_PARTITION Boot option: mac_partition_load="YES" The &man.mac.partition.4; policy will drop processes into specific partitions based on their MAC label. Think of it as a special type of &man.jail.8;, though that is hardly a worthy comparison. This is one module that should be added to the &man.loader.conf.5; file so that it loads and enables the policy during the boot process. Most configuration for this policy is done using the &man.setpmac.8; utility which will be explained below. The following sysctl tunable is available for this policy: security.mac.partition.enabled will enable the enforcement of MAC process partitions. When this policy is enabled, users will only be permitted to see their processes but will not be permitted to work with certain utilities. For instance, a user in the insecure class above will not be permitted to access the top command as well as many other commands that must spawn a process. To set or drop utilities into a partition label, use the setpmac utility: &prompt.root; setpmac partition/13 top This will add the top command to the label set on users in the insecure class. Note that all processes spawned by users in the insecure class will stay in the partition/13 label. Examples The following command will show you the partition label and the process list: &prompt.root; ps Zax This next command will allow the viewing of another user's process partition label and that user's currently running processes: &prompt.root; ps -ZU trhodes Users can see processes in root's label unless the &man.mac.seeotheruids.4; policy is loaded. A really crafty implementation could have all of the services disabled in /etc/rc.conf and started by a script that starts them with the proper labeling set. The following policies support integer settings in place of the three default labels offered. These options, including their limitations, are further explained in the module manual pages. The MAC Multi-Level Security Module MAC Multi-Level Security Policy Module name: mac_mls.ko Kernel configuration line: options MAC_MLS Boot option: mac_mls_load="YES" The &man.mac.mls.4; policy controls access between subjects and objects in the system by enforcing a strict information flow policy. In MLS environments, a clearance level is set in each subject or objects label, along with compartments. Since these clearance or sensibility levels can reach numbers greater than six thousand; it would be a daunting task for any system administrator to thoroughly configure each subject or object. Thankfully, three instant labels are already included in this policy. These labels are mls/low, mls/equal and mls/high. Since these labels are described in depth in the manual page, they will only get a brief description here: The mls/low label contains a low configuration which permits it to be dominated by all other objects. Anything labeled with mls/low will have a low clearance level and not be permitted to access information of a higher level. In addition, this label will prevent objects of a higher clearance level from writing or passing information on to them. The mls/equal label should be placed on objects considered to be exempt from the policy. The mls/high label is the highest level of clearance possible. Objects assigned this label will hold dominance over all other objects in the system; however, they will not permit the leaking of information to objects of a lower class. MLS provides for: A hierarchical security level with a set of non hierarchical categories; Fixed rules: no read up, no write down (a subject can have read access to objects on its own level or below, but not above. Similarly, a subject can have write access to objects on its own level or above but not beneath.); Secrecy (preventing inappropriate disclosure of data); Basis for the design of systems that concurrently handle data at multiple sensitivity levels (without leaking information between secret and confidential). The following sysctl tunables are available for the configuration of special services and interfaces: security.mac.mls.enabled is used to enable/disable the MLS policy. security.mac.mls.ptys_equal will label all &man.pty.4; devices as mls/equal during creation. security.mac.mls.revocation_enabled is used to revoke access to objects after their label changes to a label of a lower grade. security.mac.mls.max_compartments is used to set the maximum number of compartment levels with objects; basically the maximum compartment number allowed on a system. To manipulate the MLS labels, the &man.setfmac.8; command has been provided. To assign a label to an object, issue the following command: &prompt.root; setfmac mls/5 test To get the MLS label for the file test issue the following command: &prompt.root; getfmac test This is a summary of the MLS policy's features. Another approach is to create a master policy - file in /etc which + file in /etc which specifies the MLS policy information and to feed that file into the setfmac command. This method will be explained after all policies are covered. Observations: an object with lower clearance is unable to observe higher clearance processes. A basic policy would be to enforce mls/high on everything not to be read, even if it needs to be written. Enforce mls/low on everything not to be written, even if it needs to be read. And finally enforce mls/equal on the rest. All users marked insecure should be set at mls/low. The MAC Biba Module MAC Biba Integrity Policy Module name: mac_biba.ko Kernel configuration line: options MAC_BIBA Boot option: mac_biba_load="YES" The &man.mac.biba.4; module loads the MAC Biba policy. This policy works much like that of the MLS policy with the exception that the rules for information flow are slightly reversed. This is said to prevent the downward flow of sensitive information whereas the MLS policy prevents the upward flow of sensitive information; thus, much of this section can apply to both policies. In Biba environments, an integrity label is set on each subject or object. These labels are made up of hierarchal grades, and non-hierarchal components. As an object's or subject's grade ascends, so does its integrity. Supported labels are biba/low, biba/equal, and biba/high; as explained below: The biba/low label is considered the lowest integrity an object or subject may have. Setting this on objects or subjects will block their write access to objects or subjects marked high. They still have read access though. The biba/equal label should only be placed on objects considered to be exempt from the policy. The biba/high label will permit writing to objects set at a lower label but not permit reading that object. It is recommended that this label be placed on objects that affect the integrity of the entire system. Biba provides for: Hierarchical integrity level with a set of non hierarchical integrity categories; Fixed rules: no write up, no read down (opposite of MLS). A subject can have write access to objects on its own level or below, but not above. Similarly, a subject can have read access to objects on its own level or above, but not below; Integrity (preventing inappropriate modification of data); Integrity levels (instead of MLS sensitivity levels). The following sysctl tunables can be used to manipulate the Biba policy. security.mac.biba.enabled may be used to enable/disable enforcement of the Biba policy on the target machine. security.mac.biba.ptys_equal may be used to disable the Biba policy on &man.pty.4; devices. security.mac.biba.revocation_enabled will force the revocation of access to objects if the label is changed to dominate the subject. To access the Biba policy setting on system objects, use the setfmac and getfmac commands: &prompt.root; setfmac biba/low test &prompt.root; getfmac test test: biba/low Observations: a lower integrity subject is unable to write to a higher integrity subject; a higher integrity subject cannot observe or read a lower integrity object. The MAC LOMAC Module MAC LOMAC Module name: mac_lomac.ko Kernel configuration line: options MAC_LOMAC Boot option: mac_lomac_load="YES" Unlike the MAC Biba policy, the &man.mac.lomac.4; policy permits access to lower integrity objects only after decreasing the integrity level to not disrupt any integrity rules. The MAC version of the Low-watermark integrity policy, not to be confused with the older &man.lomac.4; implementation, works almost identically to Biba but with the exception of using floating labels to support subject demotion via an auxiliary grade compartment. This secondary compartment takes the form of [auxgrade]. When assigning a lomac policy with an auxiliary grade, it should look a little bit like: lomac/10[2] where the number two (2) is the auxiliary grade. The MAC LOMAC policy relies on the ubiquitous labeling of all system objects with integrity labels, permitting subjects to read from low integrity objects and then downgrading the label on the subject to prevent future writes to high integrity objects. This is the [auxgrade] option discussed above, thus the policy may provide for greater compatibility and require less initial configuration than Biba. Examples Like the Biba and MLS policies; the setfmac and setpmac utilities may be used to place labels on system objects: &prompt.root; setfmac /usr/home/trhodes lomac/high[low] &prompt.root; getfmac /usr/home/trhodes lomac/high[low] Notice the auxiliary grade here is low, this is a feature provided only by the MAC LOMAC policy. Implementing a Secure Environment with MAC MAC Example Implementation The following demonstration will implement a secure environment using various MAC modules with properly configured policies. This is only a test and should not be considered the complete answer to everyone's security woes. Just implementing a policy and ignoring it never works and could be disastrous in a production environment. Before beginning this process, the multilabel option must be set on each file system as stated at the beginning of this chapter. Not doing so will result in errors. Create an insecure User Class Begin the procedure by adding the following user class to the /etc/login.conf file: insecure:\ :copyright=/etc/COPYRIGHT:\ :welcome=/etc/motd:\ :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\ :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin :manpath=/usr/share/man /usr/local/man:\ :nologin=/usr/sbin/nologin:\ :cputime=1h30m:\ :datasize=8M:\ :vmemoryuse=100M:\ :stacksize=2M:\ :memorylocked=4M:\ :memoryuse=8M:\ :filesize=8M:\ :coredumpsize=8M:\ :openfiles=24:\ :maxproc=32:\ :priority=0:\ :requirehome:\ :passwordtime=91d:\ :umask=022:\ :ignoretime@:\ :label=partition/13,mls/5: And adding the following line to the default user class: :label=mls/equal,biba/equal,partition/equal: Once this is completed, the following command must be issued to rebuild the database: &prompt.root; cap_mkdb /etc/login.conf Boot with the Correct Modules Add the following lines to /boot/loader.conf so the required modules will load during system initialization: mac_biba_load="YES" mac_mls_load="YES" mac_seeotheruids_load="YES" mac_partition_load="YES" Set All Users to Insecure All user accounts that are not root or system users will now require a login class. The login class is required otherwise users will be refused access to common commands such as &man.vi.1;. The following sh script should do the trick: &prompt.root; for x in `awk -F: '($3 >= 1001) && ($3 != 65534) { print $1 }' \ /etc/passwd`; do pw usermod $x -L insecure; done; The cap_mkdb command will need to be run on /etc/master.passwd after this change. Complete the Configuration A contexts file should now be created; the following example was taken from Robert Watson's example policy and should be placed in /etc/policy.contexts. # This is the default BIBA/MLS policy for this system. .* biba/high,mls/high /sbin/dhclient biba/high(low),mls/high(low) /dev(/.*)? biba/equal,mls/equal # This is not an exhaustive list of all "privileged" devices. /dev/mdctl biba/high,mls/high /dev/pci biba/high,mls/high /dev/k?mem biba/high,mls/high /dev/io biba/high,mls/high /dev/agp.* biba/high,mls/high (/var)?/tmp(/.*)? biba/equal,mls/equal /tmp/\.X11-unix biba/high(equal),mls/high(equal) /tmp/\.X11-unix/.* biba/equal,mls/equal /proc(/.*)? biba/equal,mls/equal /mnt.* biba/low,mls/low (/usr)?/home biba/high(low),mls/high(low) (/usr)?/home/.* biba/low,mls/low /var/mail(/.*)? biba/low,mls/low /var/spool/mqueue(/.*)? biba/low,mls/low (/mnt)?/cdrom(/.*)? biba/high,mls/high (/usr)?/home/(ftp|samba)(/.*)? biba/high,mls/high /var/log/sendmail\.st biba/low,mls/low /var/run/utmp biba/equal,mls/equal /var/log/(lastlog|wtmp) biba/equal,mls/equal This policy will enforce security by setting restrictions on both the downward and upward flow of information with regards to the directories and utilities listed on the left. This can now be read into our system by issuing the following command: &prompt.root; setfsmac -ef /etc/policy.contexts / &prompt.root; setfsmac -ef /etc/policy.contexts /usr The above file system layout may be different depending on environment. The /etc/mac.conf file requires the following modifications in the main section: default_labels file ?biba,?mls default_labels ifnet ?biba,?mls default_labels process ?biba,?mls,?partition default_labels socket ?biba,?mls Testing the Configuration MAC Configuration Testing Add a user with the adduser command and place that user in the insecure class for these tests. The examples below will show a mix of root and regular user tests; use the prompt to distinguish between the two. Basic Labeling Tests &prompt.user; getpmac biba/15(15-15),mls/15(15-15),partition/15 &prompt.root; setpmac partition/15,mls/equal top The top process will be killed before we start another top process. MAC Seeotheruids Tests &prompt.user; ps Zax biba/15(15-15),mls/15(15-15),partition/15 1096 #C: S 0:00.03 -su (bash) biba/15(15-15),mls/15(15-15),partition/15 1101 #C: R+ 0:00.01 ps Zax We should not be permitted to see any processes owned by other users. MAC Partition Test Disable the MAC seeotheruids policy for the rest of these tests: &prompt.root; sysctl security.mac.seeotheruids.enabled=0 &prompt.user; ps Zax LABEL PID TT STAT TIME COMMAND biba/equal(low-high),mls/equal(low-high),partition/15 1122 #C: S+ 0:00.02 top biba/15(15-15),mls/15(15-15),partition/15 1096 #C: S 0:00.05 -su (bash) biba/15(15-15),mls/15(15-15),partition/15 1123 #C: R+ 0:00.01 ps Zax All users should be permitted to see every process in their partition. Testing Biba and MLS Labels &prompt.root; setpmac partition/15,mls/equal,biba/high\(high-high\) top &prompt.user; ps Zax LABEL PID TT STAT TIME COMMAND biba/high(high-high),mls/equal(low-high),partition/15 1251 #C: S+ 0:00.02 top biba/15(15-15),mls/15(15-15),partition/15 1096 #C: S 0:00.06 -su (bash) biba/15(15-15),mls/15(15-15),partition/15 1157 #C: R+ 0:00.00 ps Zax The Biba policy allows us to read higher-labeled objects. &prompt.root; setpmac partition/15,mls/equal,biba/low top &prompt.user; ps Zax LABEL PID TT STAT TIME COMMAND biba/15(15-15),mls/15(15-15),partition/15 1096 #C: S 0:00.07 -su (bash) biba/15(15-15),mls/15(15-15),partition/15 1226 #C: R+ 0:00.01 ps Zax The Biba policy does not allow lower-labeled objects to be read; however, MLS does. &prompt.user; ifconfig bge0 | grep maclabel maclabel biba/low(low-low),mls/low(low-low) &prompt.user; ping -c 1 192.0.34.166 PING 192.0.34.166 (192.0.34.166): 56 data bytes ping: sendto: Permission denied Users are unable to ping example.com, or any domain for that matter. To prevent this error from occurring, run the following command: &prompt.root; sysctl security.mac.biba.trust_all_interfaces=1 This sets the default interface label to insecure mode, so the default Biba policy label will not be enforced. &prompt.root; ifconfig bge0 maclabel biba/equal\(low-high\),mls/equal\(low-high\) &prompt.user; ping -c 1 192.0.34.166 PING 192.0.34.166 (192.0.34.166): 56 data bytes 64 bytes from 192.0.34.166: icmp_seq=0 ttl=50 time=204.455 ms --- 192.0.34.166 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max/stddev = 204.455/204.455/204.455/0.000 ms By setting a more correct label, we can issue ping requests. Now to create a few files for some read and write testing procedures: &prompt.root; touch test1 test2 test3 test4 test5 &prompt.root; getfmac test1 test1: biba/equal,mls/equal &prompt.root; setfmac biba/low test1 test2; setfmac biba/high test4 test5; \ setfmac mls/low test1 test3; setfmac mls/high test2 test4 &prompt.root; setfmac mls/equal,biba/equal test3 && getfmac test? test1: biba/low,mls/low test2: biba/low,mls/high test3: biba/equal,mls/equal test4: biba/high,mls/high test5: biba/high,mls/equal &prompt.root; chown testuser:testuser test? All of these files should now be owned by our testuser user. And now for some read tests: &prompt.user; ls test1 test2 test3 test4 test5 &prompt.user; ls test? ls: test1: Permission denied ls: test2: Permission denied ls: test4: Permission denied test3 test5 We should not be permitted to observe pairs; e.g.: (biba/low,mls/low), (biba/low,mls/high) and (biba/high,mls/high). And of course, read access should be denied. Now for some write tests: &prompt.user; for i in `echo test*`; do echo 1 > $i; done -su: test1: Permission denied -su: test4: Permission denied -su: test5: Permission denied Like with the read tests, write access should not be permitted to write pairs; e.g.: (biba/low,mls/high) and (biba/equal,mls/equal). &prompt.user; cat test? cat: test1: Permission denied cat: test2: Permission denied 1 cat: test4: Permission denied And now as root: &prompt.root; cat test2 1 Another Example: Using MAC to Constrain a Web Server A separate location for the web data which users must be capable of accessing will be appointed. This will permit biba/high processes access rights to the web data. Begin by creating a directory to store the web data in: &prompt.root; mkdir /usr/home/cvs Now initialize it with cvs: &prompt.root; cvs -d /usr/home/cvs init The first goal is to enable the biba policy, thus the mac_biba_enable="YES" should be placed in /boot/loader.conf. This assumes that support for MAC has been enabled in the kernel. From this point on everything in the system should be set at biba/high by default. The following modification must be made to the login.conf file, under the default user class: :ignoretime@:\ :umask=022:\ :label=biba/high: Every user should now be placed in the default class; a command such as: &prompt.root; for x in `awk -F: '($3 >= 1001) && ($3 != 65534) { print $1 }' \ /etc/passwd`; do pw usermod $x -L default; done; will accomplish this task in a few moments. Now create another class, web, a copy of default, with the label setting of biba/low. Create a user who will be used to work with the main web data stored in a cvs repository. This user must be placed in our new login class, web. Since the default is biba/high everywhere, the repository will be the same. The web data must also be the same for users to have read/write access to it; however, since our web server will be serving data that biba/high users must access, we will need to downgrade the data as a whole. The perfect tools for this are &man.sh.1; and &man.cron.8; and are already provided in &os;. The following script should do everything we want: PATH=/bin:/usr/bin:/usr/local/bin; export PATH; CVSROOT=/home/repo; export CVSROOT; cd /home/web; cvs -qR checkout -P htdocs; exit; In many cases the cvs Id tags must be placed into the web site data files. This script may now be placed into web's home directory and the following &man.crontab.1; entry added: # Check out the web data as biba/low every twelve hours: 0 */12 * * * web /home/web/checkout.sh This will check out the HTML sources every twelve hours on the machine. The default startup method for the web server must also be modified to start the process as biba/low. This can be done by making the following modification to the /usr/local/etc/rc.d/apache.sh script: command="setpmac biba/low /usr/local/sbin/httpd" The Apache configuration must be altered to work with the biba/low policy. In this case the software must be configured to append to the log files in a directory set at biba/low or else access denied errors will be returned. Following this example requires that the docroot directive be set to /home/web/htdocs; otherwise, Apache will fail when trying to locate the directory to serve documents from. Other configuration variables must be altered as well, including the PID file, Scoreboardfile, DocumentRoot, log file locations, or any other variable which requires write access. When using biba, all write access will be denied to the server in areas not set at biba/low. Troubleshooting the MAC Framework MAC Troubleshooting During the development stage, a few users reported problems with normal configuration. Some of these problems are listed below: The <option>multilabel</option> option cannot be enabled on <filename>/</filename> The flag does not stay enabled on my root (/) partition! It seems that one out of every fifty users has this problem, indeed, we had this problem during our initial configuration. Further observation of this so called bug has lead me to believe that it is a result of either incorrect documentation or misinterpretation of the documentation. Regardless of why it happened, the following steps may be taken to resolve it: Edit /etc/fstab and set the root partition at for read-only. Reboot into single user mode. Run tunefs on /. Reboot the system into normal mode. Run mount / and change the back to in /etc/fstab and reboot the system again. Double-check the output from the mount to ensure that has been properly set on the root file system. Cannot start &xfree86; after <acronym>MAC</acronym> After establishing a secure environment with MAC, I am no longer able to start &xfree86;! This could be caused by the MAC partition policy or by a mislabeling in one of the MAC labeling policies. To debug, try the following: Check the error message; if the user is in the insecure class, the partition policy may be the culprit. Try setting the user's class back to the default class and rebuild the database with the cap_mkdb command. If this does not alleviate the problem, go to step two. Double-check the label policies. Ensure that the policies are set correctly for the user in question, the &xfree86; application, and - the /dev + the /dev entries. If neither of these resolve the problem, send the error message and a description of your environment to the TrustedBSD discussion lists located at the TrustedBSD website or to the &a.questions; mailing list. Error: &man..secure.path.3; cannot stat <filename>.login_conf</filename> When I attempt to switch from the root to another user in the system, the error message _secure_path: unable to state .login_conf. This message is usually shown when the user has a higher label setting then that of the user whom they are attempting to become. For instance a user on the system, joe, has a default label of . The root user, who has a label of , cannot view joe's home directory. This will happen regardless if root has used the su command to become joe, or not. In this scenario, the Biba integrity model will not permit root to view objects set at a lower integrity level. The <username>root</username> username is broken! In normal or even single user mode, the root is not recognized. The whoami command returns 0 (zero) and su returns who are you?. What could be going on? This can happen if a labeling policy has been disabled, either by a &man.sysctl.8; or the policy module was unloaded. If the policy is being disabled or has been temporarily disabled, then the login capabilities database needs to be reconfigured with the option being removed. Double check the login.conf file to ensure that all options have been removed and rebuild the database with the cap_mkdb command. diff --git a/en_US.ISO8859-1/books/handbook/mail/chapter.sgml b/en_US.ISO8859-1/books/handbook/mail/chapter.sgml index fb01ea2f46..d23caf576f 100644 --- a/en_US.ISO8859-1/books/handbook/mail/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/mail/chapter.sgml @@ -1,2295 +1,2295 @@ Bill Lloyd Original work by Jim Mock Rewritten by Electronic Mail Synopsis email electronic mail Electronic Mail, better known as email, is one of the most widely used forms of communication today. This chapter provides a basic introduction to running a mail server on &os;, as well as an introduction to sending and receiving email using &os;; however, it is not a complete reference and in fact many important considerations are omitted. For more complete coverage of the subject, the reader is referred to the many excellent books listed in . After reading this chapter, you will know: What software components are involved in sending and receiving electronic mail. Where basic sendmail configuration files are located in FreeBSD. The difference between remote and local mailboxes. How to block spammers from illegally using your mail server as a relay. How to install and configure an alternate Mail Transfer Agent on your system, replacing sendmail. How to troubleshoot common mail server problems. How to use SMTP with UUCP. How to set up the system to send mail only. How to use mail with a dialup connection. How to configure SMTP Authentication for added security. How to install and use a Mail User Agent, such as mutt to send and receive email. How to download your mail from a remote POP or IMAP server. How to automatically apply filters and rules to incoming email. Before reading this chapter, you should: Properly set up your network connection (). Properly set up the DNS information for your mail host (). Know how to install additional third-party software (). Using Electronic Mail POP IMAP DNS There are five major parts involved in an email exchange. They are: the user program, the server daemon, DNS, a remote or local mailbox, and of course, the mailhost itself. The User Program This includes command line programs such as mutt, pine, elm, and mail, and GUI programs such as balsa, xfmail to name a few, and something more sophisticated like a WWW browser. These programs simply pass off the email transactions to the local mailhost, either by calling one of the server daemons available, or delivering it over TCP. Mailhost Server Daemon mail server daemons sendmail mail server daemons postfix mail server daemons qmail mail server daemons exim &os; ships with sendmail by default, but also support numerous other mail server daemons, just some of which include: exim; postfix; qmail. The server daemon usually has two functions—it is responsible for receiving incoming mail as well as delivering outgoing mail. It is not responsible for the collection of mail using protocols such as POP or IMAP to read your email, nor does it allow connecting to local mbox or Maildir mailboxes. You may require an additional daemon for that. Older versions of sendmail have some serious security issues which may result in an attacker gaining local and/or remote access to your machine. Make sure that you are running a current version to avoid these problems. Optionally, install an alternative MTA from the &os; Ports Collection. Email and DNS The Domain Name System (DNS) and its daemon named play a large role in the delivery of email. In order to deliver mail from your site to another, the server daemon will look up the remote site in the DNS to determine the host that will receive mail for the destination. This process also occurs when mail is sent from a remote host to your mail server. MX record DNS is responsible for mapping hostnames to IP addresses, as well as for storing information specific to mail delivery, known as MX records. The MX (Mail eXchanger) record specifies which host, or hosts, will receive mail for a particular domain. If you do not have an MX record for your hostname or domain, the mail will be delivered directly to your host provided you have an A record pointing your hostname to your IP address. You may view the MX records for any domain by using the &man.host.1; command, as seen in the example below: &prompt.user; host -t mx FreeBSD.org FreeBSD.org mail is handled (pri=10) by mx1.FreeBSD.org Receiving Mail email receiving Receiving mail for your domain is done by the mail host. It will collect all mail sent to your domain and store it either in mbox (the default method for storing mail) or Maildir format, depending on your configuration. Once mail has been stored, it may either be read locally using applications such as &man.mail.1; or mutt, or remotely accessed and collected using protocols such as POP or IMAP. This means that should you only wish to read mail locally, you are not required to install a POP or IMAP server. Accessing remote mailboxes using <acronym>POP</acronym> and <acronym>IMAP</acronym> POP IMAP In order to access mailboxes remotely, you are required to have access to a POP or IMAP server. These protocols allow users to connect to their mailboxes from remote locations with ease. Though both POP and IMAP allow users to remotely access mailboxes, IMAP offers many advantages, some of which are: IMAP can store messages on a remote server as well as fetch them. IMAP supports concurrent updates. IMAP can be extremely useful over low-speed links as it allows users to fetch the structure of messages without downloading them; it can also perform tasks such as searching on the server in order to minimize data transfer between clients and servers. In order to install a POP or IMAP server, the following steps should be performed: Choose an IMAP or POP server that best suits your needs. The following POP and IMAP servers are well known and serve as some good examples: qpopper; teapop; imap-uw; courier-imap; Install the POP or IMAP daemon of your choosing from the ports collection. Where required, modify /etc/inetd.conf to load the POP or IMAP server. It should be noted that both POP and IMAP transmit information, including username and password credentials in clear-text. This means that if you wish to secure the transmission of information across these protocols, you should consider tunneling sessions over &man.ssh.1;. Tunneling sessions is described in . Accessing local mailboxes Mailboxes may be accessed locally by directly utilizing MUAs on the server on which the mailbox resides. This can be done using applications such as mutt or &man.mail.1;. The Mail Host mail host The mail host is the name given to a server that is responsible for delivering and receiving mail for your host, and possibly your network. Christopher Shumway Contributed by <application>sendmail</application> Configuration sendmail &man.sendmail.8; is the default Mail Transfer Agent (MTA) in FreeBSD. sendmail's job is to accept mail from Mail User Agents (MUA) and deliver it to the appropriate mailer as defined by its configuration file. sendmail can also accept network connections and deliver mail to local mailboxes or deliver it to another program. sendmail uses the following configuration files: /etc/mail/access /etc/mail/aliases /etc/mail/local-host-names /etc/mail/mailer.conf /etc/mail/mailertable /etc/mail/sendmail.cf /etc/mail/virtusertable Filename Function /etc/mail/access sendmail access database file /etc/mail/aliases Mailbox aliases /etc/mail/local-host-names Lists of hosts sendmail accepts mail for /etc/mail/mailer.conf Mailer program configuration /etc/mail/mailertable Mailer delivery table /etc/mail/sendmail.cf sendmail master configuration file /etc/mail/virtusertable Virtual users and domain tables <filename>/etc/mail/access</filename> The access database defines what host(s) or IP addresses have access to the local mail server and what kind of access they have. Hosts can be listed as , , or simply passed to sendmail's error handling routine with a given mailer error. Hosts that are listed as , which is the default, are allowed to send mail to this host as long as the mail's final destination is the local machine. Hosts that are listed as are rejected for all mail connections. Hosts that have the option for their hostname are allowed to send mail for any destination through this mail server. Configuring the <application>sendmail</application> Access Database cyberspammer.com 550 We don't accept mail from spammers FREE.STEALTH.MAILER@ 550 We don't accept mail from spammers another.source.of.spam REJECT okay.cyberspammer.com OK 128.32 RELAY In this example we have five entries. Mail senders that match the left hand side of the table are affected by the action on the right side of the table. The first two examples give an error code to sendmail's error handling routine. The message is printed to the remote host when a mail matches the left hand side of the table. The next entry rejects mail from a specific host on the Internet, another.source.of.spam. The next entry accepts mail connections from a host okay.cyberspammer.com, which is more exact than the cyberspammer.com line above. More specific matches override less exact matches. The last entry allows relaying of electronic mail from hosts with an IP address that begins with 128.32. These hosts would be able to send mail through this mail server that are destined for other mail servers. When this file is updated, you need to run make in /etc/mail/ to update the database. <filename>/etc/mail/aliases</filename> The aliases database contains a list of virtual mailboxes that are expanded to other user(s), files, programs or other aliases. Here are a few examples that can be used in /etc/mail/aliases: Mail Aliases root: localuser ftp-bugs: joe,eric,paul bit.bucket: /dev/null procmail: "|/usr/local/bin/procmail" The file format is simple; the mailbox name on the left side of the colon is expanded to the target(s) on the right. The first example simply expands the mailbox root to the mailbox localuser, which is then looked up again in the aliases database. If no match is found, then the message is delivered to the local user localuser. The next example shows a mail list. Mail to the mailbox ftp-bugs is expanded to the three local mailboxes joe, eric, and paul. Note that a remote mailbox could be specified as user@example.com. The next example shows writing mail to a file, in this case /dev/null. The last example shows sending mail to a program, in this case the mail message is written to the standard input of /usr/local/bin/procmail through a &unix; pipe. When this file is updated, you need to run make in /etc/mail/ to update the database. <filename>/etc/mail/local-host-names</filename> This is a list of hostnames &man.sendmail.8; is to accept as the local host name. Place any domains or hosts that sendmail is to be receiving mail for. For example, if this mail server was to accept mail for the domain example.com and the host mail.example.com, its local-host-names might look something like this: example.com mail.example.com When this file is updated, &man.sendmail.8; needs to be restarted to read the changes. <filename>/etc/mail/sendmail.cf</filename> sendmail's master configuration file, sendmail.cf controls the overall behavior of sendmail, including everything from rewriting e-mail addresses to printing rejection messages to remote mail servers. Naturally, with such a diverse role, this configuration file is quite complex and its details are a bit out of the scope of this section. Fortunately, this file rarely needs to be changed for standard mail servers. The master sendmail configuration file can be built from &man.m4.1; macros that define the features and behavior of sendmail. Please see /usr/src/contrib/sendmail/cf/README for some of the details. When changes to this file are made, sendmail needs to be restarted for the changes to take effect. <filename>/etc/mail/virtusertable</filename> The virtusertable maps mail addresses for virtual domains and mailboxes to real mailboxes. These mailboxes can be local, remote, aliases defined in /etc/mail/aliases or files. Example Virtual Domain Mail Map root@example.com root postmaster@example.com postmaster@noc.example.net @example.com joe In the above example, we have a mapping for a domain example.com. This file is processed in a first match order down the file. The first item maps root@example.com to the local mailbox root. The next entry maps postmaster@example.com to the mailbox postmaster on the host noc.example.net. Finally, if nothing from example.com has matched so far, it will match the last mapping, which matches every other mail message addressed to someone at example.com. This will be mapped to the local mailbox joe. Andrew Boothman Written by Gregory Neil Shapiro Information taken from e-mails written by Changing Your Mail Transfer Agent email change mta As already mentioned, FreeBSD comes with sendmail already installed as your MTA (Mail Transfer Agent). Therefore by default it is in charge of your outgoing and incoming mail. However, for a variety of reasons, some system administrators want to change their system's MTA. These reasons range from simply wanting to try out another MTA to needing a specific feature or package which relies on another mailer. Fortunately, whatever the reason, FreeBSD makes it easy to make the change. Install a New MTA You have a wide choice of MTAs available. A good starting point is the FreeBSD Ports Collection where you will be able to find many. Of course you are free to use any MTA you want from any location, as long as you can make it run under FreeBSD. Start by installing your new MTA. Once it is installed it gives you a chance to decide if it really fulfills your needs, and also gives you the opportunity to configure your new software before getting it to take over from sendmail. When doing this, you should be sure that installing the new software will not attempt to overwrite system binaries such as /usr/bin/sendmail. Otherwise, your new mail software has essentially been put into service before you have configured it. Please refer to your chosen MTA's documentation for information on how to configure the software you have chosen. Disable <application>sendmail</application> The procedure used to start sendmail changed significantly between 4.5-RELEASE and 4.6-RELEASE. Therefore, the procedure used to disable it is subtly different. FreeBSD 4.5-STABLE before 2002/4/4 and Earlier (Including 4.5-RELEASE and Earlier) Enter: sendmail_enable="NO" into /etc/rc.conf. This will disable sendmail's incoming mail service, but if /etc/mail/mailer.conf (see below) is not changed, sendmail will still be used to send e-mail. FreeBSD 4.5-STABLE after 2002/4/4 (Including 4.6-RELEASE and Later) In order to completely disable sendmail you must use sendmail_enable="NONE" in /etc/rc.conf. If you disable sendmail's outgoing mail service in this way, it is important that you replace it with a fully working alternative mail delivery system. If you choose not to, system functions such as &man.periodic.8; will be unable to deliver their results by e-mail as they would normally expect to. Many parts of your system may expect to have a functional sendmail-compatible system. If applications continue to use sendmail's binaries to try to send e-mail after you have disabled them, mail could go into an inactive sendmail queue, and never be delivered. If you only want to disable sendmail's incoming mail service, you should set sendmail_enable="NO" in /etc/rc.conf. More information on sendmail's startup options is available from the &man.rc.sendmail.8; manual page. Running Your New MTA on Boot You may have a choice of two methods for running your new MTA on boot, again depending on what version of FreeBSD you are running. FreeBSD 4.5-STABLE before 2002/4/11 (Including 4.5-RELEASE and Earlier) Add a script to /usr/local/etc/rc.d/ that ends in .sh and is executable by root. The script should accept start and stop parameters. At startup time the system scripts will execute the command /usr/local/etc/rc.d/supermailer.sh start which you can also use to manually start the server. At shutdown time, the system scripts will use the stop option, running the command /usr/local/etc/rc.d/supermailer.sh stop which you can also use to manually stop the server while the system is running. FreeBSD 4.5-STABLE after 2002/4/11 (Including 4.6-RELEASE and Later) With later versions of FreeBSD, you can use the above method or you can set mta_start_script="filename" in /etc/rc.conf, where filename is the name of some script that you want executed at boot to start your MTA. Replacing <application>sendmail</application> as the System's Default Mailer The program sendmail is so ubiquitous as standard software on &unix; systems that some software just assumes it is already installed and configured. For this reason, many alternative MTA's provide their own compatible implementations of the sendmail command-line interface; this facilitates using them as drop-in replacements for sendmail. Therefore, if you are using an alternative mailer, you will need to make sure that software trying to execute standard sendmail binaries such as /usr/bin/sendmail actually executes your chosen mailer instead. Fortunately, FreeBSD provides a system called &man.mailwrapper.8; that does this job for you. When sendmail is operating as installed, you will find something like the following in /etc/mail/mailer.conf: sendmail /usr/libexec/sendmail/sendmail send-mail /usr/libexec/sendmail/sendmail mailq /usr/libexec/sendmail/sendmail newaliases /usr/libexec/sendmail/sendmail hoststat /usr/libexec/sendmail/sendmail purgestat /usr/libexec/sendmail/sendmail This means that when any of these common commands (such as sendmail itself) are run, the system actually invokes a copy of mailwrapper named sendmail, which checks mailer.conf and executes /usr/libexec/sendmail/sendmail instead. This system makes it easy to change what binaries are actually executed when these default sendmail functions are invoked. Therefore if you wanted /usr/local/supermailer/bin/sendmail-compat to be run instead of sendmail, you could change /etc/mail/mailer.conf to read: sendmail /usr/local/supermailer/bin/sendmail-compat send-mail /usr/local/supermailer/bin/sendmail-compat mailq /usr/local/supermailer/bin/mailq-compat newaliases /usr/local/supermailer/bin/newaliases-compat hoststat /usr/local/supermailer/bin/hoststat-compat purgestat /usr/local/supermailer/bin/purgestat-compat Finishing Once you have everything configured the way you want it, you should either kill the sendmail processes that you no longer need and start the processes belonging to your new software, or simply reboot. Rebooting will also give you the opportunity to ensure that you have correctly configured your system to start your new MTA automatically on boot. Troubleshooting email troubleshooting Why do I have to use the FQDN for hosts on my site? You will probably find that the host is actually in a different domain; for example, if you are in foo.bar.edu and you wish to reach a host called mumble in the bar.edu domain, you will have to refer to it by the fully-qualified domain name, mumble.bar.edu, instead of just mumble. BIND Traditionally, this was allowed by BSD BIND resolvers. However the current version of BIND that ships with FreeBSD no longer provides default abbreviations for non-fully qualified domain names other than the domain you are in. So an unqualified host mumble must either be found as mumble.foo.bar.edu, or it will be searched for in the root domain. This is different from the previous behavior, where the search continued across mumble.bar.edu, and mumble.edu. Have a look at RFC 1535 for why this was considered bad practice, or even a security hole. As a good workaround, you can place the line: search foo.bar.edu bar.edu instead of the previous: domain foo.bar.edu into your /etc/resolv.conf. However, make sure that the search order does not go beyond the boundary between local and public administration, as RFC 1535 calls it. MX record sendmail says mail loops back to myself This is answered in the sendmail FAQ as follows: I'm getting these error messages: 553 MX list for domain.net points back to relay.domain.net 554 <user@domain.net>... Local configuration error How can I solve this problem? You have asked mail to the domain (e.g., domain.net) to be forwarded to a specific host (in this case, relay.domain.net) by using an MX record, but the relay machine does not recognize itself as domain.net. Add domain.net to /etc/mail/local-host-names [known as /etc/sendmail.cw prior to version 8.10] (if you are using FEATURE(use_cw_file)) or add Cw domain.net to /etc/mail/sendmail.cf. The sendmail FAQ can be found at and is recommended reading if you want to do any tweaking of your mail setup. PPP How can I run a mail server on a dial-up PPP host? You want to connect a FreeBSD box on a LAN to the Internet. The FreeBSD box will be a mail gateway for the LAN. The PPP connection is non-dedicated. UUCP MX record There are at least two ways to do this. One way is to use UUCP. Another way is to get a full-time Internet server to provide secondary MX services for your domain. For example, if your company's domain is example.com and your Internet service provider has set example.net up to provide secondary MX services to your domain: example.com. MX 10 example.com. MX 20 example.net. Only one host should be specified as the final recipient (add Cw example.com in /etc/mail/sendmail.cf on example.com). When the sending sendmail is trying to deliver the mail it will try to connect to you (example.com) over the modem link. It will most likely time out because you are not online. The program sendmail will automatically deliver it to the secondary MX site, i.e. your Internet provider (example.net). The secondary MX site will then periodically try to connect to your host and deliver the mail to the primary MX host (example.com). You might want to use something like this as a login script: #!/bin/sh # Put me in /usr/local/bin/pppmyisp ( sleep 60 ; /usr/sbin/sendmail -q ) & /usr/sbin/ppp -direct pppmyisp If you are going to create a separate login script for a user you could use sendmail -qRexample.com instead in the script above. This will force all mail in your queue for example.com to be processed immediately. A further refinement of the situation is as follows: Message stolen from the &a.isp;. > we provide the secondary MX for a customer. The customer connects to > our services several times a day automatically to get the mails to > his primary MX (We do not call his site when a mail for his domains > arrived). Our sendmail sends the mailqueue every 30 minutes. At the > moment he has to stay 30 minutes online to be sure that all mail is > gone to the primary MX. > > Is there a command that would initiate sendmail to send all the mails > now? The user has not root-privileges on our machine of course. In the privacy flags section of sendmail.cf, there is a definition Opgoaway,restrictqrun Remove restrictqrun to allow non-root users to start the queue processing. You might also like to rearrange the MXs. We are the 1st MX for our customers like this, and we have defined: # If we are the best MX for a host, try directly instead of generating # local config error. OwTrue That way a remote site will deliver straight to you, without trying the customer connection. You then send to your customer. Only works for hosts, so you need to get your customer to name their mail machine customer.com as well as hostname.customer.com in the DNS. Just put an A record in the DNS for customer.com. Why do I keep getting Relaying Denied errors when sending mail from other hosts? In default FreeBSD installations, sendmail is configured to only send mail from the host it is running on. For example, if a POP server is available, then users will be able to check mail from school, work, or other remote locations but they still will not be able to send outgoing emails from outside locations. Typically, a few moments after the attempt, an email will be sent from MAILER-DAEMON with a 5.7 Relaying Denied error message. There are several ways to get around this. The most straightforward solution is to put your ISP's address in a relay-domains file at /etc/mail/relay-domains. A quick way to do this would be: &prompt.root; echo "your.isp.example.com" > /etc/mail/relay-domains After creating or editing this file you must restart sendmail. This works great if you are a server administrator and do not wish to send mail locally, or would like to use a point and click client/system on another machine or even another ISP. It is also very useful if you only have one or two email accounts set up. If there is a large number of addresses to add, you can simply open this file in your favorite text editor and then add the domains, one per line: your.isp.example.com other.isp.example.net users-isp.example.org www.example.org Now any mail sent through your system, by any host in this list (provided the user has an account on your system), will succeed. This is a very nice way to allow users to send mail from your system remotely without allowing people to send SPAM through your system. Advanced Topics The following section covers more involved topics such as mail configuration and setting up mail for your entire domain. Basic Configuration email configuration Out of the box, you should be able to send email to external hosts as long as you have set up /etc/resolv.conf or are running your own name server. If you would like to have mail for your host delivered to the MTA (e.g., sendmail) on your own FreeBSD host, there are two methods: Run your own name server and have your own domain. For example, FreeBSD.org Get mail delivered directly to your host. This is done by delivering mail directly to the current DNS name for your machine. For example, example.FreeBSD.org. SMTP Regardless of which of the above you choose, in order to have mail delivered directly to your host, it must have a permanent static IP address (not a dynamic address, as with most PPP dial-up configurations). If you are behind a firewall, it must pass SMTP traffic on to you. If you want to receive mail directly at your host, you need to be sure of either of two things: MX record Make sure that the (lowest-numbered) MX record in your DNS points to your host's IP address. Make sure there is no MX entry in your DNS for your host. Either of the above will allow you to receive mail directly at your host. Try this: &prompt.root; hostname example.FreeBSD.org &prompt.root; host example.FreeBSD.org example.FreeBSD.org has address 204.216.27.XX If that is what you see, mail directly to yourlogin@example.FreeBSD.org should work without problems (assuming sendmail is running correctly on example.FreeBSD.org). If instead you see something like this: &prompt.root; host example.FreeBSD.org example.FreeBSD.org has address 204.216.27.XX example.FreeBSD.org mail is handled (pri=10) by hub.FreeBSD.org All mail sent to your host (example.FreeBSD.org) will end up being collected on hub under the same username instead of being sent directly to your host. The above information is handled by your DNS server. The DNS record that carries mail routing information is the Mail eXchange entry. If no MX record exists, mail will be delivered directly to the host by way of its IP address. The MX entry for freefall.FreeBSD.org at one time looked like this: freefall MX 30 mail.crl.net freefall MX 40 agora.rdrop.com freefall MX 10 freefall.FreeBSD.org freefall MX 20 who.cdrom.com As you can see, freefall had many MX entries. The lowest MX number is the host that receives mail directly if available; if it is not accessible for some reason, the others (sometimes called backup MXes) accept messages temporarily, and pass it along when a lower-numbered host becomes available, eventually to the lowest-numbered host. Alternate MX sites should have separate Internet connections from your own in order to be most useful. Your ISP or another friendly site should have no problem providing this service for you. Mail for Your Domain In order to set up a mailhost (a.k.a. mail server) you need to have any mail sent to various workstations directed to it. Basically, you want to claim any mail for any hostname in your domain (in this case *.FreeBSD.org) and divert it to your mail server so your users can receive their mail on the master mail server. DNS To make life easiest, a user account with the same username should exist on both machines. Use &man.adduser.8; to do this. The mailhost you will be using must be the designated mail exchanger for each workstation on the network. This is done in your DNS configuration like so: example.FreeBSD.org A 204.216.27.XX ; Workstation MX 10 hub.FreeBSD.org ; Mailhost This will redirect mail for the workstation to the mailhost no matter where the A record points. The mail is sent to the MX host. You cannot do this yourself unless you are running a DNS server. If you are not, or cannot run your own DNS server, talk to your ISP or whoever provides your DNS. If you are doing virtual email hosting, the following information will come in handy. For this example, we will assume you have a customer with his own domain, in this case customer1.org, and you want all the mail for customer1.org sent to your mailhost, mail.myhost.com. The entry in your DNS should look like this: customer1.org MX 10 mail.myhost.com You do not need an A record for customer1.org if you only want to handle email for that domain. Be aware that pinging customer1.org will not work unless an A record exists for it. The last thing that you must do is tell sendmail on your mailhost what domains and/or hostnames it should be accepting mail for. There are a few different ways this can be done. Either of the following will work: Add the hosts to your /etc/mail/local-host-names file if you are using the FEATURE(use_cw_file). If you are using a version of sendmail earlier than 8.10, the file is /etc/sendmail.cw. Add a Cwyour.host.com line to your /etc/sendmail.cf or /etc/mail/sendmail.cf if you are using sendmail 8.10 or higher. SMTP with UUCP The sendmail configuration that ships with FreeBSD is designed for sites that connect directly to the Internet. Sites that wish to exchange their mail via UUCP must install another sendmail configuration file. Tweaking /etc/mail/sendmail.cf manually is an advanced topic. sendmail version 8 generates config files via &man.m4.1; preprocessing, where the actual configuration occurs on a higher abstraction level. The &man.m4.1; configuration files can be found under /usr/src/usr.sbin/sendmail/cf. If you did not install your system with full sources, the sendmail configuration set has been broken out into a separate source distribution tarball. Assuming you have your FreeBSD source code CDROM mounted, do: &prompt.root; cd /cdrom/src &prompt.root; cat scontrib.?? | tar xzf - -C /usr/src/contrib/sendmail This extracts to only a few hundred kilobytes. The file README in the cf directory can serve as a basic introduction to &man.m4.1; configuration. The best way to support UUCP delivery is to use the mailertable feature. This creates a database that sendmail can use to make routing decisions. First, you have to create your .mc file. The directory /usr/src/usr.sbin/sendmail/cf/cf contains a few examples. Assuming you have named your file foo.mc, all you need to do in order to convert it into a valid sendmail.cf is: &prompt.root; cd /usr/src/usr.sbin/sendmail/cf/cf &prompt.root; make foo.cf &prompt.root; cp foo.cf /etc/mail/sendmail.cf A typical .mc file might look like: VERSIONID(`Your version number') OSTYPE(bsd4.4) FEATURE(accept_unresolvable_domains) FEATURE(nocanonify) FEATURE(mailertable, `hash -o /etc/mail/mailertable') define(`UUCP_RELAY', your.uucp.relay) define(`UUCP_MAX_SIZE', 200000) define(`confDONT_PROBE_INTERFACES') MAILER(local) MAILER(smtp) MAILER(uucp) Cw your.alias.host.name Cw youruucpnodename.UUCP The lines containing accept_unresolvable_domains, nocanonify, and confDONT_PROBE_INTERFACES features will prevent any usage of the DNS during mail delivery. The UUCP_RELAY clause is needed to support UUCP delivery. Simply put an Internet hostname there that is able to handle .UUCP pseudo-domain addresses; most likely, you will enter the mail relay of your ISP there. Once you have this, you need an /etc/mail/mailertable file. If you have only one link to the outside that is used for all your mails, the following file will suffice: # # makemap hash /etc/mail/mailertable.db < /etc/mail/mailertable . uucp-dom:your.uucp.relay A more complex example might look like this: # # makemap hash /etc/mail/mailertable.db < /etc/mail/mailertable # horus.interface-business.de uucp-dom:horus .interface-business.de uucp-dom:if-bus interface-business.de uucp-dom:if-bus .heep.sax.de smtp8:%1 horus.UUCP uucp-dom:horus if-bus.UUCP uucp-dom:if-bus . uucp-dom: The first three lines handle special cases where domain-addressed mail should not be sent out to the default route, but instead to some UUCP neighbor in order to shortcut the delivery path. The next line handles mail to the local Ethernet domain that can be delivered using SMTP. Finally, the UUCP neighbors are mentioned in the .UUCP pseudo-domain notation, to allow for a uucp-neighbor !recipient override of the default rules. The last line is always a single dot, matching everything else, with UUCP delivery to a UUCP neighbor that serves as your universal mail gateway to the world. All of the node names behind the uucp-dom: keyword must be valid UUCP neighbors, as you can verify using the command uuname. As a reminder that this file needs to be converted into a DBM database file before use. The command line to accomplish this is best placed as a comment at the top of the mailertable file. You always have to execute this command each time you change your mailertable file. Final hint: if you are uncertain whether some particular mail routing would work, remember the option to sendmail. It starts sendmail in address test mode; simply enter 3,0, followed by the address you wish to test for the mail routing. The last line tells you the used internal mail agent, the destination host this agent will be called with, and the (possibly translated) address. Leave this mode by typing CtrlD. &prompt.user; sendmail -bt ADDRESS TEST MODE (ruleset 3 NOT automatically invoked) Enter <ruleset> <address> > 3,0 foo@example.com canonify input: foo @ example . com ... parse returns: $# uucp-dom $@ your.uucp.relay $: foo < @ example . com . > > ^D Bill Moran Contributed by Setting Up to Send Only There are many instances where you may only want to send mail through a relay. Some examples are: Your computer is a desktop machine, but you want to use programs such as &man.send-pr.1;. To do so, you should use your ISP's mail relay. The computer is a server that does not handle mail locally, but needs to pass off all mail to a relay for processing. Just about any MTA is capable of filling this particular niche. Unfortunately, it can be very difficult to properly configure a full-featured MTA just to handle offloading mail. Programs such as sendmail and postfix are largely overkill for this use. Additionally, if you are using a typical Internet access service, your agreement may forbid you from running a mail server. The easiest way to fulfill those needs is to install the mail/ssmtp port. Execute the following commands as root: &prompt.root; cd /usr/ports/mail/ssmtp &prompt.root; make install replace clean Once installed, mail/ssmtp can be configured with a four-line file located at /usr/local/etc/ssmtp/ssmtp.conf: root=yourrealemail@example.com mailhub=mail.example.com rewriteDomain=example.com hostname=_HOSTNAME_ Make sure you use your real email address for root. Enter your ISP's outgoing mail relay in place of mail.example.com (some ISPs call this the outgoing mail server or SMTP server). Make sure you disable sendmail by setting sendmail_enable="NONE" in /etc/rc.conf. mail/ssmtp has some other options available. See the example configuration file in /usr/local/etc/ssmtp or the manual page of ssmtp for some examples and more information. Setting up ssmtp in this manner will allow any software on your computer that needs to send mail to function properly, while not violating your ISP's usage policy or allowing your computer to be hijacked for spamming. Using Mail with a Dialup Connection If you have a static IP address, you should not need to adjust anything from the defaults. Set your host name to your assigned Internet name and sendmail will do the rest. If you have a dynamically assigned IP number and use a dialup PPP connection to the Internet, you will probably have a mailbox on your ISPs mail server. Let's assume your ISP's domain is example.net, and that your user name is user, you have called your machine bsd.home, and your ISP has told you that you may use relay.example.net as a mail relay. In order to retrieve mail from your mailbox, you must install a retrieval agent. The fetchmail utility is a good choice as it supports many different protocols. This program is available as a package or from the ports collection (mail/fetchmail). Usually, your ISP will provide POP. If you are using user PPP, you can automatically fetch your mail when an Internet connection is established with the following entry in /etc/ppp/ppp.linkup: MYADDR: !bg su user -c fetchmail If you are using sendmail (as shown below) to deliver mail to non-local accounts, you probably want to have sendmail process your mailqueue as soon as your Internet connection is established. To do this, put this command after the fetchmail command in /etc/ppp/ppp.linkup: !bg su user -c "sendmail -q" Assume that you have an account for user on bsd.home. In the home directory of user on bsd.home, create a .fetchmailrc file: poll example.net protocol pop3 fetchall pass MySecret This file should not be readable by anyone except user as it contains the password MySecret. In order to send mail with the correct from: header, you must tell sendmail to use user@example.net rather than user@bsd.home. You may also wish to tell sendmail to send all mail via relay.example.net, allowing quicker mail transmission. The following .mc file should suffice: VERSIONID(`bsd.home.mc version 1.0') OSTYPE(bsd4.4)dnl FEATURE(nouucp)dnl MAILER(local)dnl MAILER(smtp)dnl Cwlocalhost Cwbsd.home MASQUERADE_AS(`example.net')dnl FEATURE(allmasquerade)dnl FEATURE(masquerade_envelope)dnl FEATURE(nocanonify)dnl FEATURE(nodns)dnl define(`SMART_HOST', `relay.example.net') Dmbsd.home define(`confDOMAIN_NAME',`bsd.home')dnl define(`confDELIVERY_MODE',`deferred')dnl Refer to the previous section for details of how to turn this .mc file into a sendmail.cf file. Also, do not forget to restart sendmail after updating sendmail.cf. James Gorham Written by SMTP Authentication Having SMTP Authentication in place on your mail server has a number of benefits. SMTP Authentication can add another layer of security to sendmail, and has the benefit of giving mobile users who switch hosts the ability to use the same mail server without the need to reconfigure their mail client settings each time. Install security/cyrus-sasl from the ports. You can find this port in security/cyrus-sasl. security/cyrus-sasl has a number of compile time options to choose from and, for the method we will be using here, make sure to select the option. After installing security/cyrus-sasl, edit /usr/local/lib/sasl/Sendmail.conf (or create it if it does not exist) and add the following line: pwcheck_method: passwd This method will enable sendmail to authenticate against your FreeBSD passwd database. This saves the trouble of creating a new set of usernames and passwords for each user that needs to use SMTP authentication, and keeps the login and mail password the same. Now edit /etc/make.conf and add the following lines: SENDMAIL_CFLAGS=-I/usr/local/include/sasl1 -DSASL SENDMAIL_LDFLAGS=-L/usr/local/lib SENDMAIL_LDADD=-lsasl These lines will give sendmail the proper configuration options for linking to cyrus-sasl at compile time. Make sure that cyrus-sasl has been installed before recompiling sendmail. Recompile sendmail by executing the following commands: &prompt.root; cd /usr/src/usr.sbin/sendmail &prompt.root; make cleandir &prompt.root; make obj &prompt.root; make &prompt.root; make install The compile of sendmail should not have any problems if /usr/src has not been changed extensively and the shared libraries it needs are available. After sendmail has been compiled and reinstalled, edit your /etc/mail/freebsd.mc file (or whichever file you use as your .mc file. Many administrators choose to use the output from &man.hostname.1; as the .mc file for uniqueness). Add these lines to it: dnl set SASL options TRUST_AUTH_MECH(`GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl define(`confAUTH_MECHANISMS', `GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl define(`confDEF_AUTH_INFO', `/etc/mail/auth-info')dnl These options configure the different methods available to sendmail for authenticating users. If you would like to use a method other than pwcheck, please see the included documentation. Finally, run &man.make.1; while in /etc/mail. That will run your new .mc file and create a .cf file named freebsd.cf (or whatever name you have used for your .mc file). Then use the command make install restart, which will copy the file to sendmail.cf, and will properly restart sendmail. For more information about this process, you should refer to /etc/mail/Makefile. If all has gone correctly, you should be able to enter your login information into the mail client and send a test message. For further investigation, set the of sendmail to 13 and watch /var/log/maillog for any errors. You may wish to add the following lines to /etc/rc.conf so this service will be available after every system boot: sasl_pwcheck_enable="YES" sasl_pwcheck_program="/usr/local/sbin/pwcheck" This will ensure the initialization of SMTP_AUTH upon system boot. For more information, please see the sendmail page regarding SMTP authentication. Marc Silver Contributed by Mail User Agents Mail User Agents A Mail User Agent (MUA) is an application that is used to send and receive email. Furthermore, as email evolves and becomes more complex, MUA's are becoming increasingly powerful in the way they interact with email; this gives users increased functionality and flexibility. &os; contains support for numerous mail user agents, all of which can be easily installed using the FreeBSD Ports Collection. Users may choose between graphical email clients such as evolution or balsa, console based clients such as mutt, pine or mail, or the web interfaces used by some large organizations. mail &man.mail.1; is the default Mail User Agent (MUA) in &os;. It is a console based MUA that offers all the basic functionality required to send and receive text-based email, though it is limited in interaction abilities with attachments and can only support local mailboxes. Although mail does not natively support interaction with POP or IMAP servers, these mailboxes may be downloaded to a local mbox file using an application such as fetchmail, which will be discussed later in this chapter (). In order to send and receive email, simply invoke the mail command as per the following example: &prompt.user; mail The contents of the user mailbox in - /var/mail are + /var/mail are automatically read by the mail utility. Should the mailbox be empty, the utility exits with a message indicating that no mails could be found. Once the mailbox has been read, the application interface is started, and a list of messages will be displayed. Messages are automatically numbered, as can be seen in the following example: Mail version 8.1 6/6/93. Type ? for help. "/var/mail/marcs": 3 messages 3 new >N 1 root@localhost Mon Mar 8 14:05 14/510 "test" N 2 root@localhost Mon Mar 8 14:05 14/509 "user account" N 3 root@localhost Mon Mar 8 14:05 14/509 "sample" Messages can now be read by using the t mail command, suffixed by the message number that should be displayed. In this example, we will read the first email: & t 1 Message 1: From root@localhost Mon Mar 8 14:05:52 2004 X-Original-To: marcs@localhost Delivered-To: marcs@localhost To: marcs@localhost Subject: test Date: Mon, 8 Mar 2004 14:05:52 +0200 (SAST) From: root@localhost (Charlie Root) This is a test message, please reply if you receive it. As can be seen in the example above, the t key will cause the message to be displayed with full headers. To display the list of messages again, the h key should be used. If the email requires a response, you may use mail to reply, by using either the R or r mail keys. The R key instructs mail to reply only to the sender of the email, while r replies not only to the sender, but also to other recipients of the message. You may also suffix these commands with the mail number which you would like make a reply to. Once this has been done, the response should be entered, and the end of the message should be marked by a single . on a new line. An example can be seen below: & R 1 To: root@localhost Subject: Re: test Thank you, I did get your email. . EOT In order to send new email, the m key should be used, followed by the recipient email address. Multiple recipients may also be specified by separating each address with the , delimiter. The subject of the message may then be entered, followed by the message contents. The end of the message should be specified by putting a single . on a new line. & mail root@localhost Subject: I mastered mail Now I can send and receive email using mail ... :) . EOT While inside the mail utility, the ? command may be used to display help at any time, the &man.mail.1; manual page should also be consulted for more help with mail. As previously mentioned, the &man.mail.1; command was not originally designed to handle attachments, and thus deals with them very poorly. Newer MUAs such as mutt handle attachments in a much more intelligent way. But should you still wish to use the mail command, the converters/mpack port may be of considerable use. mutt mutt is a small yet very powerful Mail User Agent, with excellent features, just some of which include: The ability to thread messages; PGP support for digital signing and encryption of email; MIME Support; Maildir Support; Highly customizable. All of these features help to make mutt one of the most advanced mail user agents available. See for more information on mutt. The stable version of mutt may be installed using the mail/mutt port, while the current development version may be installed via the mail/mutt-devel port. After the port has been installed, mutt can be started by issuing the following command: &prompt.user; mutt mutt will automatically read the contents of the user mailbox in /var/mail and display the contents + class="directory">/var/mail and display the contents if applicable. If no mails are found in the user mailbox, then mutt will wait for commands from the user. The example below shows mutt displaying a list of messages: In order to read an email, simply select it using the cursor keys, and press the Enter key. An example of mutt displaying email can be seen below: As with the &man.mail.1; command, mutt allows users to reply only to the sender of the message as well as to all recipients. To reply only to the sender of the email, use the r keyboard shortcut. To send a group reply, which will be sent to the original sender as well as all the message recipients, use the g shortcut. mutt makes use of the &man.vi.1; command as an editor for creating and replying to emails. This may be customized by the user by creating or editing their own .muttrc file in their home directory and setting the editor variable. In order to compose a new mail message, press m. After a valid subject has been given, mutt will start &man.vi.1; and the mail can be written. Once the contents of the mail are complete, save and quit from vi and mutt will resume, displaying a summary screen of the mail that is to be delivered. In order to send the mail, press y. An example of the summary screen can be seen below: mutt also contains extensive help, which can be accessed from most of the menus by pressing the ? key. The top line also displays the keyboard shortcuts where appropriate. pine pine is aimed at a beginner user, but also includes some advanced features. The pine software has had several remote vulnerabilities discovered in the past, which allowed remote attackers to execute arbitrary code as users on the local system, by the action of sending a specially-prepared email. All such known problems have been fixed, but the pine code is written in a very insecure style and the &os; Security Officer believes there are likely to be other undiscovered vulnerabilities. You install pine at your own risk. The current version of pine may be installed using the mail/pine4 port. Once the port has installed, pine can be started by issuing the following command: &prompt.user; pine The first time that pine is run it displays a greeting page with a brief introduction, as well as a request from the pine development team to send an anonymous email message allowing them to judge how many users are using their client. To send this anonymous message, press Enter, or alternatively press E to exit the greeting without sending an anonymous message. An example of the greeting page can be seen below: Users are then presented with the main menu, which can be easily navigated using the cursor keys. This main menu provides shortcuts for the composing new mails, browsing of mail directories, and even the administration of address book entries. Below the main menu, relevant keyboard shortcuts to perform functions specific to the task at hand are shown. The default directory opened by pine - is the inbox. To view the message index, press + is the inbox. To view the message index, press I, or select the MESSAGE INDEX option as seen below: The message index shows messages in the current directory, and can be navigated by using the cursor keys. Highlighted messages can be read by pressing the Enter key. In the screenshot below, a sample message is displayed by pine. Keyboard shortcuts are displayed as a reference at the bottom of the screen. An example of one of these shortcuts is the r key, which tells the MUA to reply to the current message being displayed. Replying to an email in pine is done using the pico editor, which is installed by default with pine. The pico utility makes it easy to navigate around the message and is slightly more forgiving on novice users than &man.vi.1; or &man.mail.1;. Once the reply is complete, the message can be sent by pressing CtrlX . The pine application will ask for confirmation. The pine application can be customized using the SETUP option from the main menu. Consult for more information. Marc Silver Contributed by Using fetchmail Using fetchmail fetchmail is a full-featured IMAP and POP client which allows users to automatically download mail from remote IMAP and POP servers and save it into local mailboxes; there it can be accessed more easily. fetchmail can be installed using the mail/fetchmail port, and offers various features, some of which include: Support of POP3, APOP, KPOP, IMAP, ETRN and ODMR protocols. Ability to forward mail using SMTP, which allows filtering, forwarding, and aliasing to function normally. May be run in daemon mode to check periodically for new messages. Can retrieve multiple mailboxes and forward them based on configuration, to different local users. While it is outside the scope of this document to explain all of fetchmail's features, some basic features will be explained. The fetchmail utility requires a configuration file known as .fetchmailrc, in order to run correctly. This file includes server information as well as login credentials. Due to the sensitive nature of the contents of this file, it is advisable to make it readable only by the owner, with the following command: &prompt.user; chmod 600 .fetchmailrc The following .fetchmailrc serves as an example for downloading a single user mailbox using POP. It tells fetchmail to connect to example.com using a username of joesoap and a password of XXX. This example assumes that the user joesoap is also a user on the local system. poll example.com protocol pop3 username "joesoap" password "XXX" The next example connects to multiple POP and IMAP servers and redirects to different local usernames where applicable: poll example.com proto pop3: user "joesoap", with password "XXX", is "jsoap" here; user "andrea", with password "XXXX"; poll example2.net proto imap: user "john", with password "XXXXX", is "myth" here; The fetchmail utility can be run in daemon mode by running it with the flag, followed by the interval (in seconds) that fetchmail should poll servers listed in the .fetchmailrc file. The following example would cause fetchmail to poll every 60 seconds: &prompt.user; fetchmail -d 60 More information on fetchmail can be found at . Marc Silver Contributed by Using procmail Using procmail The procmail utility is an incredibly powerful application used to filter incoming mail. It allows users to define rules which can be matched to incoming mails to perform specific functions or to reroute mail to alternative mailboxes and/or email addresses. procmail can be installed using the mail/procmail port. Once installed, it can be directly integrated into most MTAs; consult your MTA documentation for more information. Alternatively, procmail can be integrated by adding the following line to a .forward in the home directory of the user utilizing procmail features: "|exec /usr/local/bin/procmail || exit 75" The following section will display some basic procmail rules, as well as brief descriptions on what they do. These rules, and others must be inserted into a .procmailrc file, which must reside in the user's home directory. The majority of these rules can also be found in the &man.procmailex.5; manual page. Forward all mail from user@example.com to an external address of goodmail@example2.com: :0 * ^From.*user@example.com ! goodmail@example2.com Forward all mails shorter than 1000 bytes to an external address of goodmail@example2.com: :0 * < 1000 ! goodmail@example2.com Send all mail sent to alternate@example.com into a mailbox called alternate: :0 * ^TOalternate@example.com alternate Send all mail with a subject of Spam to /dev/null: :0 ^Subject:.*Spam /dev/null A useful recipe that parses incoming &os;.org mailing lists and places each list in its own mailbox: :0 * ^Sender:.owner-freebsd-\/[^@]+@FreeBSD.ORG { LISTNAME=${MATCH} :0 * LISTNAME??^\/[^@]+ FreeBSD-${MATCH} } diff --git a/en_US.ISO8859-1/books/handbook/mirrors/chapter.sgml b/en_US.ISO8859-1/books/handbook/mirrors/chapter.sgml index e99eb25dd0..2a5a749ee0 100644 --- a/en_US.ISO8859-1/books/handbook/mirrors/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/mirrors/chapter.sgml @@ -1,2857 +1,2857 @@ Obtaining FreeBSD CDROM and DVD Publishers Retail Boxed Products FreeBSD is available as a boxed product (FreeBSD CDs, additional software, and printed documentation) from several retailers:
CompUSA WWW:
Frys Electronics WWW:
CD and DVD Sets FreeBSD CD and DVD sets are available from many online retailers:
BSD Mall by Daemon News PO Box 161 Nauvoo, IL 62354 USA Phone: +1 866 273-6255 Fax: +1 217 453-9956 Email: sales@bsdmall.com WWW:
BSD-Systems Email: info@bsd-systems.co.uk WWW:
fastdiscs.com 6 Eltham Close Leeds, LS6 2TY United Kingdom Phone: +44 870 1995 171 Email: sales@fastdiscs.com WWW:
FreeBSD Mall, Inc. 3623 Sanford Street Concord, CA 94520-1405 USA Phone: +1 925 674-0783 Fax: +1 925 674-0821 Email: info@freebsdmall.com WWW:
FreeBSD Services Ltd 11 Lapwing Close Bicester OX26 6XR United Kingdom WWW:
Hinner EDV St. Augustinus-Str. 10 D-81825 München Germany Phone: (089) 428 419 WWW:
Ikarios 22-24 rue Voltaire 92000 Nanterre France WWW:
Ingram Micro 1600 E. St. Andrew Place Santa Ana, CA 92705-4926 USA Phone: 1 (800) 456-8000 WWW:
JMC Software Ireland Phone: 353 1 6291282 WWW:
The Linux Emporium Hilliard House, Lester Way Wallingford OX10 9TA United Kingdom Phone: +44 1491 837010 Fax: +44 1491 837016 WWW:
Linux System Labs Australia 21 Ray Drive Balwyn North VIC - 3104 Australia Phone: +61 3 9857 5918 Fax: +61 3 9857 8974 WWW:
LinuxCenter.Ru Galernaya Street, 55 Saint-Petersburg 190000 Russia Phone: +7-812-3125208 Email: info@linuxcenter.ru WWW:
UNIXDVD.COM LTD 57 Primrose Avenue Sheffield S5 6FS United Kingdom WWW:
Distributors If you are a reseller and want to carry FreeBSD CDROM products, please contact a distributor:
Cylogistics 809B Cuesta Dr., #2149 Mountain View, CA 94040 USA Phone: +1 650 694-4949 Fax: +1 650 694-4953 Email: sales@cylogistics.com WWW:
FreeBSD Services Ltd 11 Lapwing Close Bicester OX26 6XR United Kingdom WWW:
Kudzu, LLC 7375 Washington Ave. S. Edina, MN 55439 USA Phone: +1 952 947-0822 Fax: +1 952 947-0876 Email: sales@kudzuenterprises.com
LinuxCenter.Ru Galernaya Street, 55 Saint-Petersburg 190000 Russia Phone: +7-812-3125208 Email: info@linuxcenter.ru WWW:
Navarre Corp 7400 49th Ave South New Hope, MN 55428 USA Phone: +1 763 535-8333 Fax: +1 763 535-0341 WWW:
FTP Sites The official sources for FreeBSD are available via anonymous FTP from a worldwide set of mirror sites. The site is well connected and allows a large number of connections to it, but you are probably better off finding a closer mirror site (especially if you decide to set up some sort of mirror site). The FreeBSD mirror sites database is more accurate than the mirror listing in the Handbook, as it gets its information from the DNS rather than relying on static lists of hosts. Additionally, FreeBSD is available via anonymous FTP from the following mirror sites. If you choose to obtain FreeBSD via anonymous FTP, please try to use a site near you. The mirror sites listed as Primary Mirror Sites typically have the entire FreeBSD archive (all the currently available versions for each of the architectures) but you will probably have faster download times from a site that is in your country or region. The regional sites carry the most recent versions for the most popular architecture(s) but might not carry the entire FreeBSD archive. All sites provide access via anonymous FTP but some sites also provide access via other methods. The access methods available for each site are provided in parenthesis after the hostname. &chap.mirrors.ftp.inc; Anonymous CVS <anchor id="anoncvs-intro">Introduction Anonymous CVS (or, as it is otherwise known, anoncvs) is a feature provided by the CVS utilities bundled with FreeBSD for synchronizing with a remote CVS repository. Among other things, it allows users of FreeBSD to perform, with no special privileges, read-only CVS operations against one of the FreeBSD project's official anoncvs servers. To use it, one simply sets the CVSROOT environment variable to point at the appropriate anoncvs server, provides the well-known password anoncvs with the cvs login command, and then uses the &man.cvs.1; command to access it like any local repository. The cvs login command, stores the passwords that are used for authenticating to the CVS server in a file called .cvspass in your HOME directory. If this file does not exist, you might get an error when trying to use cvs login for the first time. Just make an empty .cvspass file, and retry to login. While it can also be said that the CVSup and anoncvs services both perform essentially the same function, there are various trade-offs which can influence the user's choice of synchronization methods. In a nutshell, CVSup is much more efficient in its usage of network resources and is by far the most technically sophisticated of the two, but at a price. To use CVSup, a special client must first be installed and configured before any bits can be grabbed, and then only in the fairly large chunks which CVSup calls collections. Anoncvs, by contrast, can be used to examine anything from an individual file to a specific program (like ls or grep) by referencing the CVS module name. Of course, anoncvs is also only good for read-only operations on the CVS repository, so if it is your intention to support local development in one repository shared with the FreeBSD project bits then CVSup is really your only option. <anchor id="anoncvs-usage">Using Anonymous CVS Configuring &man.cvs.1; to use an Anonymous CVS repository is a simple matter of setting the CVSROOT environment variable to point to one of the FreeBSD project's anoncvs servers. At the time of this writing, the following servers are available: Austria: :pserver:anoncvs@anoncvs.at.FreeBSD.org:/home/ncvs (Use cvs login and enter any password when prompted.) France: :pserver:anoncvs@anoncvs.fr.FreeBSD.org:/home/ncvs (pserver (password anoncvs), ssh (no password)) Germany: :pserver:anoncvs@anoncvs.de.FreeBSD.org:/home/ncvs (Use cvs login and enter the password anoncvs when prompted.) Germany: :pserver:anoncvs@anoncvs2.de.FreeBSD.org:/home/ncvs (rsh, pserver, ssh, ssh/2022) Japan: :pserver:anoncvs@anoncvs.jp.FreeBSD.org:/home/ncvs (Use cvs login and enter the password anoncvs when prompted.) Sweden: freebsdanoncvs@anoncvs.se.FreeBSD.org:/home/ncvs (ssh only - no password) USA: freebsdanoncvs@anoncvs.FreeBSD.org:/home/ncvs (ssh only - no password) USA: anoncvs@anoncvs1.FreeBSD.org:/home/ncvs (ssh only - no password) Since CVS allows one to check out virtually any version of the FreeBSD sources that ever existed (or, in some cases, will exist), you need to be familiar with the revision () flag to &man.cvs.1; and what some of the permissible values for it in the FreeBSD Project repository are. There are two kinds of tags, revision tags and branch tags. A revision tag refers to a specific revision. Its meaning stays the same from day to day. A branch tag, on the other hand, refers to the latest revision on a given line of development, at any given time. Because a branch tag does not refer to a specific revision, it may mean something different tomorrow than it means today. contains revision tags that users might be interested in. Again, none of these are valid for the ports collection since the ports collection does not have multiple revisions. When you specify a branch tag, you normally receive the latest versions of the files on that line of development. If you wish to receive some past version, you can do so by specifying a date with the flag. See the &man.cvs.1; manual page for more details. Examples While it really is recommended that you read the manual page for &man.cvs.1; thoroughly before doing anything, here are some quick examples which essentially show how to use Anonymous CVS: Checking Out Something from -CURRENT (&man.ls.1;) and Deleting It Again: &prompt.user; setenv CVSROOT :pserver:anoncvs@anoncvs.FreeBSD.org:/home/ncvs &prompt.user; cvs login At the prompt, enter the password anoncvs. &prompt.user; cvs co ls &prompt.user; cvs release -d ls &prompt.user; cvs logout Using SSH to check out the <filename>src/</filename> tree: &prompt.user; cvs -d freebsdanoncvs@anoncvs.FreeBSD.org:/home/ncvs co src The authenticity of host 'anoncvs.freebsd.org (128.46.156.46)' can't be established. DSA key fingerprint is 52:02:38:1a:2f:a8:71:d3:f5:83:93:8d:aa:00:6f:65. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'anoncvs.freebsd.org' (DSA) to the list of known hosts. Checking Out the Version of &man.ls.1; in the 3.X-STABLE Branch: &prompt.user; setenv CVSROOT :pserver:anoncvs@anoncvs.FreeBSD.org:/home/ncvs &prompt.user; cvs login At the prompt, enter the password anoncvs. &prompt.user; cvs co -rRELENG_3 ls &prompt.user; cvs release -d ls &prompt.user; cvs logout Creating a List of Changes (as Unified Diffs) to &man.ls.1; &prompt.user; setenv CVSROOT :pserver:anoncvs@anoncvs.FreeBSD.org:/home/ncvs &prompt.user; cvs login At the prompt, enter the password anoncvs. &prompt.user; cvs rdiff -u -rRELENG_3_0_0_RELEASE -rRELENG_3_4_0_RELEASE ls &prompt.user; cvs logout Finding Out What Other Module Names Can Be Used: &prompt.user; setenv CVSROOT :pserver:anoncvs@anoncvs.FreeBSD.org:/home/ncvs &prompt.user; cvs login At the prompt, enter the password anoncvs. &prompt.user; cvs co modules &prompt.user; more modules/modules &prompt.user; cvs release -d modules &prompt.user; cvs logout Other Resources The following additional resources may be helpful in learning CVS: CVS Tutorial from Cal Poly. CVS Home, the CVS development and support community. CVSweb is the FreeBSD Project web interface for CVS. Using CTM CTM is a method for keeping a remote directory tree in sync with a central one. It has been developed for usage with FreeBSD's source trees, though other people may find it useful for other purposes as time goes by. Little, if any, documentation currently exists at this time on the process of creating deltas, so contact the &a.ctm-users.name; mailing list for more information and if you wish to use CTM for other things. Why Should I Use <application>CTM</application>? CTM will give you a local copy of the FreeBSD source trees. There are a number of flavors of the tree available. Whether you wish to track the entire CVS tree or just one of the branches, CTM can provide you the information. If you are an active developer on FreeBSD, but have lousy or non-existent TCP/IP connectivity, or simply wish to have the changes automatically sent to you, CTM was made for you. You will need to obtain up to three deltas per day for the most active branches. However, you should consider having them sent by automatic email. The sizes of the updates are always kept as small as possible. This is typically less than 5K, with an occasional (one in ten) being 10-50K and every now and then a large 100K+ or more coming around. You will also need to make yourself aware of the various caveats related to working directly from the development sources rather than a pre-packaged release. This is particularly true if you choose the current sources. It is recommended that you read Staying current with FreeBSD. What Do I Need to Use <application>CTM</application>? You will need two things: The CTM program, and the initial deltas to feed it (to get up to current levels). The CTM program has been part of FreeBSD ever since version 2.0 was released, and lives in /usr/src/usr.sbin/ctm if you have a copy of the source available. If you are running a pre-2.0 version of FreeBSD, you can fetch the current CTM sources directly from: The deltas you feed CTM can be had two ways, FTP or email. If you have general FTP access to the Internet then the following FTP sites support access to CTM: or see section mirrors. FTP the relevant directory and fetch the README file, starting from there. If you wish to get your deltas via email: Subscribe to one of the CTM distribution lists. &a.ctm-cvs-cur.name; supports the entire CVS tree. &a.ctm-src-cur.name; supports the head of the development branch. &a.ctm-src-4.name; supports the 4.X release branch, etc.. (If you do not know how to subscribe yourself to a list, click on the list name above or go to &a.mailman.lists.link; and click on the list that you wish to subscribe to. The list page should contain all of the necessary subscription instructions.) When you begin receiving your CTM updates in the mail, you may use the ctm_rmail program to unpack and apply them. You can actually use the ctm_rmail program directly from a entry in /etc/aliases if you want to have the process run in a fully automated fashion. Check the ctm_rmail manual page for more details. No matter what method you use to get the CTM deltas, you should subscribe to the &a.ctm-announce.name; mailing list. In the future, this will be the only place where announcements concerning the operations of the CTM system will be posted. Click on the list name above and follow the instructions to subscribe to the list. Using <application>CTM</application> for the First Time Before you can start using CTM deltas, you will need to get to a starting point for the deltas produced subsequently to it. First you should determine what you already have. Everyone can start from an empty directory. You must use an initial Empty delta to start off your CTM supported tree. At some point it is intended that one of these started deltas be distributed on the CD for your convenience, however, this does not currently happen. Since the trees are many tens of megabytes, you should prefer to start from something already at hand. If you have a -RELEASE CD, you can copy or extract an initial source from it. This will save a significant transfer of data. You can recognize these starter deltas by the X appended to the number (src-cur.3210XEmpty.gz for instance). The designation following the X corresponds to the origin of your initial seed. Empty is an empty directory. As a rule a base transition from Empty is produced every 100 deltas. By the way, they are large! 70 to 80 Megabytes of gzip'd data is common for the XEmpty deltas. Once you have picked a base delta to start from, you will also need all deltas with higher numbers following it. Using <application>CTM</application> in Your Daily Life To apply the deltas, simply say: &prompt.root; cd /where/ever/you/want/the/stuff &prompt.root; ctm -v -v /where/you/store/your/deltas/src-xxx.* CTM understands deltas which have been put through gzip, so you do not need to gunzip them first, this saves disk space. Unless it feels very secure about the entire process, CTM will not touch your tree. To verify a delta you can also use the flag and CTM will not actually touch your tree; it will merely verify the integrity of the delta and see if it would apply cleanly to your current tree. There are other options to CTM as well, see the manual pages or look in the sources for more information. That is really all there is to it. Every time you get a new delta, just run it through CTM to keep your sources up to date. Do not remove the deltas if they are hard to download again. You just might want to keep them around in case something bad happens. Even if you only have floppy disks, consider using fdwrite to make a copy. Keeping Your Local Changes As a developer one would like to experiment with and change files in the source tree. CTM supports local modifications in a limited way: before checking for the presence of a file foo, it first looks for foo.ctm. If this file exists, CTM will operate on it instead of foo. This behavior gives us a simple way to maintain local changes: simply copy the files you plan to modify to the corresponding file names with a .ctm suffix. Then you can freely hack the code, while CTM keeps the .ctm file up-to-date. Other Interesting <application>CTM</application> Options Finding Out Exactly What Would Be Touched by an Update You can determine the list of changes that CTM will make on your source repository using the option to CTM. This is useful if you would like to keep logs of the changes, pre- or post- process the modified files in any manner, or just are feeling a tad paranoid. Making Backups Before Updating Sometimes you may want to backup all the files that would be changed by a CTM update. Specifying the option causes CTM to backup all files that would be touched by a given CTM delta to backup-file. Restricting the Files Touched by an Update Sometimes you would be interested in restricting the scope of a given CTM update, or may be interested in extracting just a few files from a sequence of deltas. You can control the list of files that CTM would operate on by specifying filtering regular expressions using the and options. For example, to extract an up-to-date copy of lib/libc/Makefile from your collection of saved CTM deltas, run the commands: &prompt.root; cd /where/ever/you/want/to/extract/it/ &prompt.root; ctm -e '^lib/libc/Makefile' ~ctm/src-xxx.* For every file specified in a CTM delta, the and options are applied in the order given on the command line. The file is processed by CTM only if it is marked as eligible after all the and options are applied to it. Future Plans for <application>CTM</application> Tons of them: Use some kind of authentication into the CTM system, so as to allow detection of spoofed CTM updates. Clean up the options to CTM, they became confusing and counter intuitive. Miscellaneous Stuff There is a sequence of deltas for the ports collection too, but interest has not been all that high yet. CTM Mirrors CTM/FreeBSD is available via anonymous FTP from the following mirror sites. If you choose to obtain CTM via anonymous FTP, please try to use a site near you. In case of problems, please contact the &a.ctm-users.name; mailing list. California, Bay Area, official source South Africa, backup server for old deltas Taiwan/R.O.C. If you did not find a mirror near to you or the mirror is incomplete, try to use a search engine such as alltheweb. Using CVSup Introduction CVSup is a software package for distributing and updating source trees from a master CVS repository on a remote server host. The FreeBSD sources are maintained in a CVS repository on a central development machine in California. With CVSup, FreeBSD users can easily keep their own source trees up to date. CVSup uses the so-called pull model of updating. Under the pull model, each client asks the server for updates, if and when they are wanted. The server waits passively for update requests from its clients. Thus all updates are instigated by the client. The server never sends unsolicited updates. Users must either run the CVSup client manually to get an update, or they must set up a cron job to run it automatically on a regular basis. The term CVSup, capitalized just so, refers to the entire software package. Its main components are the client cvsup which runs on each user's machine, and the server cvsupd which runs at each of the FreeBSD mirror sites. As you read the FreeBSD documentation and mailing lists, you may see references to sup. Sup was the predecessor of CVSup, and it served a similar purpose. CVSup is used much in the same way as sup and, in fact, uses configuration files which are backward-compatible with sup's. Sup is no longer used in the FreeBSD project, because CVSup is both faster and more flexible. Installation The easiest way to install CVSup is to use the precompiled net/cvsup package from the FreeBSD packages collection. If you prefer to build CVSup from source, you can use the net/cvsup port instead. But be forewarned: the net/cvsup port depends on the Modula-3 system, which takes a substantial amount of time and disk space to download and build. If you are going to be using CVSup on a machine which will not have &xfree86; or &xorg; installed, such as a server, be sure to use the port which does not include the CVSup GUI, net/cvsup-without-gui. CVSup Configuration CVSup's operation is controlled by a configuration file called the supfile. There are some sample supfiles in the directory /usr/share/examples/cvsup/. The information in a supfile answers the following questions for CVSup: Which files do you want to receive? Which versions of them do you want? Where do you want to get them from? Where do you want to put them on your own machine? Where do you want to put your status files? In the following sections, we will construct a typical supfile by answering each of these questions in turn. First, we describe the overall structure of a supfile. A supfile is a text file. Comments begin with # and extend to the end of the line. Lines that are blank and lines that contain only comments are ignored. Each remaining line describes a set of files that the user wishes to receive. The line begins with the name of a collection, a logical grouping of files defined by the server. The name of the collection tells the server which files you want. After the collection name come zero or more fields, separated by white space. These fields answer the questions listed above. There are two types of fields: flag fields and value fields. A flag field consists of a keyword standing alone, e.g., delete or compress. A value field also begins with a keyword, but the keyword is followed without intervening white space by = and a second word. For example, release=cvs is a value field. A supfile typically specifies more than one collection to receive. One way to structure a supfile is to specify all of the relevant fields explicitly for each collection. However, that tends to make the supfile lines quite long, and it is inconvenient because most fields are the same for all of the collections in a supfile. CVSup provides a defaulting mechanism to avoid these problems. Lines beginning with the special pseudo-collection name *default can be used to set flags and values which will be used as defaults for the subsequent collections in the supfile. A default value can be overridden for an individual collection, by specifying a different value with the collection itself. Defaults can also be changed or augmented in mid-supfile by additional *default lines. With this background, we will now proceed to construct a supfile for receiving and updating the main source tree of FreeBSD-CURRENT. Which files do you want to receive? The files available via CVSup are organized into named groups called collections. The collections that are available are described in the following section. In this example, we wish to receive the entire main source tree for the FreeBSD system. There is a single large collection src-all which will give us all of that. As a first step toward constructing our supfile, we simply list the collections, one per line (in this case, only one line): src-all Which version(s) of them do you want? With CVSup, you can receive virtually any version of the sources that ever existed. That is possible because the cvsupd server works directly from the CVS repository, which contains all of the versions. You specify which one of them you want using the tag= and value fields. Be very careful to specify any tag= fields correctly. Some tags are valid only for certain collections of files. If you specify an incorrect or misspelled tag, CVSup will delete files which you probably do not want deleted. In particular, use only tag=. for the ports-* collections. The tag= field names a symbolic tag in the repository. There are two kinds of tags, revision tags and branch tags. A revision tag refers to a specific revision. Its meaning stays the same from day to day. A branch tag, on the other hand, refers to the latest revision on a given line of development, at any given time. Because a branch tag does not refer to a specific revision, it may mean something different tomorrow than it means today. contains branch tags that users might be interested in. When specifying a tag in CVSup's configuration file, it must be preceded with tag= (RELENG_4 will become tag=RELENG_4). Keep in mind that only the tag=. is relevant for the ports collection. Be very careful to type the tag name exactly as shown. CVSup cannot distinguish between valid and invalid tags. If you misspell the tag, CVSup will behave as though you had specified a valid tag which happens to refer to no files at all. It will delete your existing sources in that case. When you specify a branch tag, you normally receive the latest versions of the files on that line of development. If you wish to receive some past version, you can do so by specifying a date with the value field. The &man.cvsup.1; manual page explains how to do that. For our example, we wish to receive FreeBSD-CURRENT. We add this line at the beginning of our supfile: *default tag=. There is an important special case that comes into play if you specify neither a tag= field nor a date= field. In that case, you receive the actual RCS files directly from the server's CVS repository, rather than receiving a particular version. Developers generally prefer this mode of operation. By maintaining a copy of the repository itself on their systems, they gain the ability to browse the revision histories and examine past versions of files. This gain is achieved at a large cost in terms of disk space, however. Where do you want to get them from? We use the host= field to tell cvsup where to obtain its updates. Any of the CVSup mirror sites will do, though you should try to select one that is close to you in cyberspace. In this example we will use a fictional FreeBSD distribution site, cvsup99.FreeBSD.org: *default host=cvsup99.FreeBSD.org You will need to change the host to one that actually exists before running CVSup. On any particular run of cvsup, you can override the host setting on the command line, with . Where do you want to put them on your own machine? The prefix= field tells cvsup where to put the files it receives. In this example, we will put the source files directly into our main source tree, /usr/src. The src directory is already implicit in the collections we have chosen to receive, so this is the correct specification: *default prefix=/usr Where should cvsup maintain its status files? The CVSup client maintains certain status files in what is called the base directory. These files help CVSup to work more efficiently, by keeping track of which updates you have already received. We will use the standard base directory, /var/db: *default base=/var/db If your base directory does not already exist, now would be a good time to create it. The cvsup client will refuse to run if the base directory does not exist. Miscellaneous supfile settings: There is one more line of boiler plate that normally needs to be present in the supfile: *default release=cvs delete use-rel-suffix compress release=cvs indicates that the server should get its information out of the main FreeBSD CVS repository. This is virtually always the case, but there are other possibilities which are beyond the scope of this discussion. delete gives CVSup permission to delete files. You should always specify this, so that CVSup can keep your source tree fully up-to-date. CVSup is careful to delete only those files for which it is responsible. Any extra files you happen to have will be left strictly alone. use-rel-suffix is ... arcane. If you really want to know about it, see the &man.cvsup.1; manual page. Otherwise, just specify it and do not worry about it. compress enables the use of gzip-style compression on the communication channel. If your network link is T1 speed or faster, you probably should not use compression. Otherwise, it helps substantially. Putting it all together: Here is the entire supfile for our example: *default tag=. *default host=cvsup99.FreeBSD.org *default prefix=/usr *default base=/var/db *default release=cvs delete use-rel-suffix compress src-all The <filename>refuse</filename> File As mentioned above, CVSup uses a pull method. Basically, this means that you connect to the CVSup server, and it says, Here is what you can download from me..., and your client responds OK, I will take this, this, this, and this. In the default configuration, the CVSup client will take every file associated with the collection and tag you chose in the configuration file. However, this is not always what you want, especially if you are synching the doc, ports, or www trees — most people cannot read four or five languages, and therefore they do not need to download the language-specific files. If you are CVSuping the ports collection, you can get around this by specifying each collection individually (e.g., ports-astrology, ports-biology, etc instead of simply saying ports-all). However, since the doc and www trees do not have language-specific collections, you must use one of CVSup's many nifty features: the refuse file. The refuse file essentially tells CVSup that it should not take every single file from a collection; in other words, it tells the client to refuse certain files from the server. The refuse file can be found (or, if you do not yet have one, should be placed) in base/sup/. base is defined in your supfile; our defined base is /var/db, which means that by default the refuse file is /var/db/sup/refuse. The refuse file has a very simple format; it simply contains the names of files or directories that you do not wish to download. For example, if you cannot speak any languages other than English and some German, and you do not feel the need to read the German translation of documentation, you can put the following in your refuse file: doc/da_* doc/de_* doc/el_* doc/es_* doc/fr_* doc/it_* doc/ja_* doc/nl_* doc/no_* doc/pl_* doc/pt_* doc/ru_* doc/sr_* doc/zh_* and so forth for the other languages (you can find the full list by browsing the FreeBSD CVS repository). With this very useful feature, those users who are on slow links or pay by the minute for their Internet connection will be able to save valuable time as they will no longer need to download files that they will never use. For more information on refuse files and other neat features of CVSup, please view its manual page. Running <application>CVSup</application> You are now ready to try an update. The command line for doing this is quite simple: &prompt.root; cvsup supfile where supfile is of course the name of the supfile you have just created. Assuming you are running under X11, cvsup will display a GUI window with some buttons to do the usual things. Press the go button, and watch it run. Since you are updating your actual /usr/src tree in this example, you will need to run the program as root so that cvsup has the permissions it needs to update your files. Having just created your configuration file, and having never used this program before, that might understandably make you nervous. There is an easy way to do a trial run without touching your precious files. Just create an empty directory somewhere convenient, and name it as an extra argument on the command line: &prompt.root; mkdir /var/tmp/dest &prompt.root; cvsup supfile /var/tmp/dest The directory you specify will be used as the destination directory for all file updates. CVSup will examine your usual files in /usr/src, but it will not modify or delete any of them. Any file updates will instead land in /var/tmp/dest/usr/src. CVSup will also leave its base directory status files untouched when run this way. The new versions of those files will be written into the specified directory. As long as you have read access to /usr/src, you do not even need to be root to perform this kind of trial run. If you are not running X11 or if you just do not like GUIs, you should add a couple of options to the command line when you run cvsup: &prompt.root; cvsup -g -L 2 supfile The tells CVSup not to use its GUI. This is automatic if you are not running X11, but otherwise you have to specify it. The tells CVSup to print out the details of all the file updates it is doing. There are three levels of verbosity, from to . The default is 0, which means total silence except for error messages. There are plenty of other options available. For a brief list of them, type cvsup -H. For more detailed descriptions, see the manual page. Once you are satisfied with the way updates are working, you can arrange for regular runs of CVSup using &man.cron.8;. Obviously, you should not let CVSup use its GUI when running it from &man.cron.8;. <application>CVSup</application> File Collections The file collections available via CVSup are organized hierarchically. There are a few large collections, and they are divided into smaller sub-collections. Receiving a large collection is equivalent to receiving each of its sub-collections. The hierarchical relationships among collections are reflected by the use of indentation in the list below. The most commonly used collections are src-all, and ports-all. The other collections are used only by small groups of people for specialized purposes, and some mirror sites may not carry all of them. cvs-all release=cvs The main FreeBSD CVS repository, including the cryptography code. distrib release=cvs Files related to the distribution and mirroring of FreeBSD. doc-all release=cvs Sources for the FreeBSD Handbook and other documentation. This does not include files for the FreeBSD web site. ports-all release=cvs The FreeBSD Ports Collection. If you do not want to update the whole of ports-all (the whole ports tree), but use one of the subcollections listed below, make sure that you always update the ports-base subcollection! Whenever something changes in the ports build infrastructure represented by ports-base, it is virtually certain that those changes will be used by real ports real soon. Thus, if you only update the real ports and they use some of the new features, there is a very high chance that their build will fail with some mysterious error message. The very first thing to do in this case is to make sure that your ports-base subcollection is up to date. ports-archivers release=cvs Archiving tools. ports-astro release=cvs Astronomical ports. ports-audio release=cvs Sound support. ports-base release=cvs The Ports Collection build infrastructure - various files located in the Mk/ and Tools/ subdirectories of /usr/ports. Please see the important warning above: you should always update this subcollection, whenever you update any part of the FreeBSD Ports Collection! ports-benchmarks release=cvs Benchmarks. ports-biology release=cvs Biology. ports-cad release=cvs Computer aided design tools. ports-chinese release=cvs Chinese language support. ports-comms release=cvs Communication software. ports-converters release=cvs character code converters. ports-databases release=cvs Databases. ports-deskutils release=cvs Things that used to be on the desktop before computers were invented. ports-devel release=cvs Development utilities. ports-dns release=cvs DNS related software. ports-editors release=cvs Editors. ports-emulators release=cvs Emulators for other operating systems. ports-finance release=cvs Monetary, financial and related applications. ports-ftp release=cvs FTP client and server utilities. ports-games release=cvs Games. ports-german release=cvs German language support. ports-graphics release=cvs Graphics utilities. ports-hungarian release=cvs Hungarian language support. ports-irc release=cvs Internet Relay Chat utilities. ports-japanese release=cvs Japanese language support. ports-java release=cvs &java; utilities. ports-korean release=cvs Korean language support. ports-lang release=cvs Programming languages. ports-mail release=cvs Mail software. ports-math release=cvs Numerical computation software. ports-mbone release=cvs MBone applications. ports-misc release=cvs Miscellaneous utilities. ports-multimedia release=cvs Multimedia software. ports-net release=cvs Networking software. ports-news release=cvs USENET news software. ports-palm release=cvs Software support for Palm series. ports-polish release=cvs Polish language support. ports-portuguese release=cvs Portuguese language support. ports-print release=cvs Printing software. ports-russian release=cvs Russian language support. ports-security release=cvs Security utilities. ports-shells release=cvs Command line shells. ports-sysutils release=cvs System utilities. ports-textproc release=cvs text processing utilities (does not include desktop publishing). ports-vietnamese release=cvs Vietnamese language support. ports-www release=cvs Software related to the World Wide Web. ports-x11 release=cvs Ports to support the X window system. ports-x11-clocks release=cvs X11 clocks. ports-x11-fm release=cvs X11 file managers. ports-x11-fonts release=cvs X11 fonts and font utilities. ports-x11-toolkits release=cvs X11 toolkits. ports-x11-servers X11 servers. ports-x11-wm X11 window managers. src-all release=cvs The main FreeBSD sources, including the cryptography code. src-base release=cvs Miscellaneous files at the top of /usr/src. src-bin release=cvs User utilities that may be needed in single-user mode (/usr/src/bin). src-contrib release=cvs Utilities and libraries from outside the FreeBSD project, used relatively unmodified (/usr/src/contrib). src-crypto release=cvs Cryptography utilities and libraries from outside the FreeBSD project, used relatively unmodified (/usr/src/crypto). src-eBones release=cvs Kerberos and DES (/usr/src/eBones). Not used in current releases of FreeBSD. src-etc release=cvs System configuration files (/usr/src/etc). src-games release=cvs Games (/usr/src/games). src-gnu release=cvs Utilities covered by the GNU Public License (/usr/src/gnu). src-include release=cvs Header files (/usr/src/include). src-kerberos5 release=cvs Kerberos5 security package (/usr/src/kerberos5). src-kerberosIV release=cvs KerberosIV security package (/usr/src/kerberosIV). src-lib release=cvs Libraries (/usr/src/lib). src-libexec release=cvs System programs normally executed by other programs (/usr/src/libexec). src-release release=cvs Files required to produce a FreeBSD release (/usr/src/release). src-sbin release=cvs System utilities for single-user mode (/usr/src/sbin). src-secure release=cvs Cryptographic libraries and commands (/usr/src/secure). src-share release=cvs Files that can be shared across multiple systems (/usr/src/share). src-sys release=cvs The kernel (/usr/src/sys). src-sys-crypto release=cvs Kernel cryptography code (/usr/src/sys/crypto). src-tools release=cvs Various tools for the maintenance of FreeBSD (/usr/src/tools). src-usrbin release=cvs User utilities (/usr/src/usr.bin). src-usrsbin release=cvs System utilities (/usr/src/usr.sbin). www release=cvs The sources for the FreeBSD WWW site. distrib release=self The CVSup server's own configuration files. Used by CVSup mirror sites. gnats release=current The GNATS bug-tracking database. mail-archive release=current FreeBSD mailing list archive. www release=current The pre-processed FreeBSD WWW site files (not the source files). Used by WWW mirror sites. For More Information For the CVSup FAQ and other information about CVSup, see The CVSup Home Page. Most FreeBSD-related discussion of CVSup takes place on the &a.hackers;. New versions of the software are announced there, as well as on the &a.announce;. Questions and bug reports should be addressed to the author of the program at cvsup-bugs@polstra.com. CVSup Sites CVSup servers for FreeBSD are running at the following sites: &chap.mirrors.cvsup.inc; CVS Tags When obtaining or updating sources using cvs or CVSup, a revision tag must be specified. A revision tag refers to either a particular line of &os; development, or a specific point in time. The first type are called branch tags, and the second type are called release tags. Branch Tags All of these, with the exception of HEAD (which is always a valid tag), only apply to the src/ tree. The ports/, doc/, and www/ trees are not branched. HEAD Symbolic name for the main line, or FreeBSD-CURRENT. Also the default when no revision is specified. In CVSup, this tag is represented by a . (not punctuation, but a literal . character). In CVS, this is the default when no revision tag is specified. It is usually not a good idea to checkout or update to CURRENT sources on a STABLE machine, unless that is your intent. RELENG_5 The line of development for FreeBSD-5.X, also known as FreeBSD 5-STABLE. RELENG_5_3 The release branch for FreeBSD-5.3, used only for security advisories and other critical fixes. RELENG_5_2 The release branch for FreeBSD-5.2 and FreeBSD-5.2.1, used only for security advisories and other critical fixes. RELENG_5_1 The release branch for FreeBSD-5.1, used only for security advisories and other critical fixes. RELENG_5_0 The release branch for FreeBSD-5.0, used only for security advisories and other critical fixes. RELENG_4 The line of development for FreeBSD-4.X, also known as FreeBSD 4-STABLE. RELENG_4_10 The release branch for FreeBSD-4.10, used only for security advisories and other critical fixes. RELENG_4_9 The release branch for FreeBSD-4.9, used only for security advisories and other critical fixes. RELENG_4_8 The release branch for FreeBSD-4.8, used only for security advisories and other critical fixes. RELENG_4_7 The release branch for FreeBSD-4.7, used only for security advisories and other critical fixes. RELENG_4_6 The release branch for FreeBSD-4.6 and FreeBSD-4.6.2, used only for security advisories and other critical fixes. RELENG_4_5 The release branch for FreeBSD-4.5, used only for security advisories and other critical fixes. RELENG_4_4 The release branch for FreeBSD-4.4, used only for security advisories and other critical fixes. RELENG_4_3 The release branch for FreeBSD-4.3, used only for security advisories and other critical fixes. RELENG_3 The line of development for FreeBSD-3.X, also known as 3.X-STABLE. RELENG_2_2 The line of development for FreeBSD-2.2.X, also known as 2.2-STABLE. This branch is mostly obsolete. Release Tags These tags refer to a specific point in time when a particular version of &os; was released. The release engineering process is documented in more detail by the Release Engineering Information and Release Process documents. - The src tree uses tag names that + The src tree uses tag names that start with RELENG_ tags. - The ports and - doc trees use tags whose names + The ports and + doc trees use tags whose names begin with RELEASE tags. - Finally, the www tree is not + Finally, the www tree is not tagged with any special name for releases. RELENG_5_3_0_RELEASE FreeBSD 5.3 RELENG_4_10_0_RELEASE FreeBSD 4.10 RELENG_5_2_1_RELEASE FreeBSD 5.2.1 RELENG_5_2_0_RELEASE FreeBSD 5.2 RELENG_4_9_0_RELEASE FreeBSD 4.9 RELENG_5_1_0_RELEASE FreeBSD 5.1 RELENG_4_8_0_RELEASE FreeBSD 4.8 RELENG_5_0_0_RELEASE FreeBSD 5.0 RELENG_4_7_0_RELEASE FreeBSD 4.7 RELENG_4_6_2_RELEASE FreeBSD 4.6.2 RELENG_4_6_1_RELEASE FreeBSD 4.6.1 RELENG_4_6_0_RELEASE FreeBSD 4.6 RELENG_4_5_0_RELEASE FreeBSD 4.5 RELENG_4_4_0_RELEASE FreeBSD 4.4 RELENG_4_3_0_RELEASE FreeBSD 4.3 RELENG_4_2_0_RELEASE FreeBSD 4.2 RELENG_4_1_1_RELEASE FreeBSD 4.1.1 RELENG_4_1_0_RELEASE FreeBSD 4.1 RELENG_4_0_0_RELEASE FreeBSD 4.0 RELENG_3_5_0_RELEASE FreeBSD-3.5 RELENG_3_4_0_RELEASE FreeBSD-3.4 RELENG_3_3_0_RELEASE FreeBSD-3.3 RELENG_3_2_0_RELEASE FreeBSD-3.2 RELENG_3_1_0_RELEASE FreeBSD-3.1 RELENG_3_0_0_RELEASE FreeBSD-3.0 RELENG_2_2_8_RELEASE FreeBSD-2.2.8 RELENG_2_2_7_RELEASE FreeBSD-2.2.7 RELENG_2_2_6_RELEASE FreeBSD-2.2.6 RELENG_2_2_5_RELEASE FreeBSD-2.2.5 RELENG_2_2_2_RELEASE FreeBSD-2.2.2 RELENG_2_2_1_RELEASE FreeBSD-2.2.1 RELENG_2_2_0_RELEASE FreeBSD-2.2.0 AFS Sites AFS servers for FreeBSD are running at the following sites: Sweden The path to the files are: /afs/stacken.kth.se/ftp/pub/FreeBSD/ stacken.kth.se # Stacken Computer Club, KTH, Sweden 130.237.234.43 #hot.stacken.kth.se 130.237.237.230 #fishburger.stacken.kth.se 130.237.234.3 #milko.stacken.kth.se Maintainer ftp@stacken.kth.se rsync Sites The following sites make FreeBSD available through the rsync protocol. The rsync utility works in much the same way as the &man.rcp.1; command, but has more options and uses the rsync remote-update protocol which transfers only the differences between two sets of files, thus greatly speeding up the synchronization over the network. This is most useful if you are a mirror site for the FreeBSD FTP server, or the CVS repository. The rsync suite is available for many operating systems, on FreeBSD, see the net/rsync port or use the package. Czech Republic rsync://ftp.cz.FreeBSD.org/ Available collections: ftp: A partial mirror of the FreeBSD FTP server. FreeBSD: A full mirror of the FreeBSD FTP server. Germany rsync://grappa.unix-ag.uni-kl.de/ Available collections: freebsd-cvs: The full FreeBSD CVS repository. This machine also mirrors the CVS repositories of the NetBSD and the OpenBSD projects, among others. Netherlands rsync://ftp.nl.FreeBSD.org/ Available collections: vol/3/freebsd-core: A full mirror of the FreeBSD FTP server. United Kingdom rsync://rsync.mirror.ac.uk/ Available collections: ftp.FreeBSD.org: A full mirror of the FreeBSD FTP server. United States of America rsync://ftp-master.FreeBSD.org/ This server may only be used by FreeBSD primary mirror sites. Available collections: FreeBSD: The master archive of the FreeBSD FTP server. acl: The FreeBSD master ACL list. rsync://ftp13.FreeBSD.org/ Available collections: FreeBSD: A full mirror of the FreeBSD FTP server. diff --git a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml index 4d8426a9a5..b9bb250f56 100644 --- a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml @@ -1,1858 +1,1858 @@ Ross Lippert Edited by Multimedia Synopsis FreeBSD supports a wide variety of sound cards, allowing you to enjoy high fidelity output from your computer. This includes the ability to record and playback audio in the MPEG Audio Layer 3 (MP3), WAV, and Ogg Vorbis formats as well as many other formats. The FreeBSD Ports Collection also contains applications allowing you to edit your recorded audio, add sound effects, and control attached MIDI devices. With some willingness to experiment, FreeBSD can support playback of video files and DVD's. The number of applications to encode, convert, and playback various video media is more limited than the number of sound applications. For example as of this writing, there is no good re-encoding application in the FreeBSD Ports Collection, which could be use to convert between formats, as there is with audio/sox. However, the software landscape in this area is changing rapidly. This chapter will describe the necessary steps to configure your sound card. The configuration and installation of X11 () has already taken care of the hardware issues for your video card, though there may be some tweaks to apply for better playback. After reading this chapter, you will know: How to configure your system so that your sound card is recognized. Methods to test that your card is working using sample applications. How to troubleshoot your sound setup. How to playback and encode MP3s and other audio. How video is supported by the X server. Some video player/encoder ports which give good results. How to playback DVD's, .mpg and .avi files. How to rip CD and DVD information into files. How to configure a TV card. How to configure an image scanner. Before reading this chapter, you should: Know how to configure and install a new kernel (). Trying to mount audio CDs with the &man.mount.8; command will result in an error, at least, and a kernel panic, at worst. These media have specialized encodings which differ from the usual ISO-filesystem. Moses Moore Contributed by Marc Fonvieille Enhanced for &os; 5.X by Setting Up the Sound Card Configuring the System PCI ISA sound cards Before you begin, you should know the model of the card you have, the chip it uses, and whether it is a PCI or ISA card. FreeBSD supports a wide variety of both PCI and ISA cards. Check the supported audio devices list of the Hardware Notes to see if your card is supported. This document will also mention which driver supports your card. kernel configuration To use your sound device, you will need to load the proper device driver. This may be accomplished in one of two ways. The easiest way is to simply load a kernel module for your sound card with &man.kldload.8; which can either be done from the command line: &prompt.root; kldload snd_emu10k1 or by adding the appropriate line to the file /boot/loader.conf like this: snd_emu10k1_load="YES" These examples are for a Creative &soundblaster; Live! sound card. Other available loadable sound modules are listed in /boot/defaults/loader.conf. If you are not sure which driver to use, you may try to load the snd_driver module: &prompt.root; kldload snd_driver This is a metadriver loading the most common device drivers at once. This speeds up the search for the correct driver. It is also possible to load all sound drivers via the /boot/loader.conf facility. Under &os; 4.X, to load all sound drivers, you have to load the snd module instead of snd_driver. A second method is to statically compile in support for your sound card in your kernel. The section below provides the information you need to add support for your hardware in this manner. For more information about recompiling your kernel, please see . Configuring a Custom Kernel with Sound Support The first thing to do is adding the generic audio driver &man.sound.4; to the kernel, for that you will need to add the following line to the kernel configuration file: device sound Under &os; 4.X, you would use the following line: device pcm Then we have to add the support for our sound card. Therefore, we need to know which driver supports the card. Check the supported audio devices list of the Hardware Notes, to determine the correct driver for your sound card. For example, a Creative &soundblaster; Live! sound card is supported by the &man.snd.emu10k1.4; driver. To add the support for this card, use the following: device "snd_emu10k1" Be sure to read the manual page of the driver for the syntax to use. Information regarding the syntax of sound drivers in the kernel configuration can also be found in the /usr/src/sys/conf/NOTES file (/usr/src/sys/i386/conf/LINT for &os; 4.X). Non-PnP ISA cards may require you to provide the kernel with information on the sound card settings (IRQ, I/O port, etc). This is done via the /boot/device.hints file. At system boot, the &man.loader.8; will read this file and pass the settings to the kernel. For example, an old Creative &soundblaster; 16 ISA non-PnP card will use the &man.snd.sbc.4; driver, with the following line added to the kernel configuration file: device sbc as well as the following in /boot/device.hints: hint.sbc.0.at="isa" hint.sbc.0.port="0x220" hint.sbc.0.irq="5" hint.sbc.0.drq="1" hint.sbc.0.flags="0x15" In this case, the card uses the 0x220 I/O port and the IRQ 5. The syntax used in the /boot/device.hints file is covered in the sound driver manual page. On &os; 4.X, these settings are directly written in the kernel configuration file. In the case of our ISA card, we would only use this line: device sbc0 at isa? port 0x220 irq 5 drq 1 flags 0x15 The settings shown above are the defaults. In some cases, you may need to change the IRQ or the other settings to match your card. See the &man.snd.sbc.4; manual page for more information. Under &os; 4.X, some systems with built-in motherboard sound devices may require the following option in the kernel configuration: options PNPBIOS Testing the Sound Card After rebooting with the modified kernel, or after loading the required module, the sound card should appear in your system message buffer (&man.dmesg.8;) as something like: pcm0: <Intel ICH3 (82801CA)> port 0xdc80-0xdcbf,0xd800-0xd8ff irq 5 at device 31.5 on pci0 pcm0: [GIANT-LOCKED] pcm0: <Cirrus Logic CS4205 AC97 Codec> The status of the sound card may be checked via the /dev/sndstat file: &prompt.root; cat /dev/sndstat FreeBSD Audio Driver (newpcm) Installed devices: pcm0: <Intel ICH3 (82801CA)> at io 0xd800, 0xdc80 irq 5 bufsz 16384 kld snd_ich (1p/2r/0v channels duplex default) The output from your system may vary. If no pcm devices show up, go back and review what was done earlier. Go through your kernel configuration file again and make sure the correct device is chosen. Common problems are listed in . If all goes well, you should now have a functioning sound card. If your CD-ROM or DVD-ROM drive is properly coupled to your sound card, you can put a CD in the drive and play it with &man.cdcontrol.1;: &prompt.user; cdcontrol -f /dev/acd0 play 1 Various applications, such as audio/workman can provide a friendlier interface. You may want to install an application such as audio/mpg123 to listen to MP3 audio files. A quick way to test the card is sending data to the /dev/dsp, like this: &prompt.user; cat filename > /dev/dsp where filename can be any file. This command line should produce some noise, confirming the sound card is actually working. &os; 4.X users need to create the sound card device nodes before being able to use it. If the card showed up in message buffer as pcm0, you will have to run the following as root: &prompt.root; cd /dev &prompt.root; sh MAKEDEV snd0 If the card detection returned pcm1, follow the same steps as shown above, replacing snd0 with snd1. MAKEDEV will create a group of device nodes that will be used by the different sound related applications. Sound card mixer levels can be changed via the &man.mixer.8; command. More details can be found in the &man.mixer.8; manual page. Common Problems device nodes I/O port IRQ DSP Error Solution unsupported subdevice XX One or more of the device nodes was not created correctly. Repeat the steps above. sb_dspwr(XX) timed out The I/O port is not set correctly. bad irq XX The IRQ is set incorrectly. Make sure that the set IRQ and the sound IRQ are the same. xxx: gus pcm not attached, out of memory There is not enough available memory to use the device. xxx: can't open /dev/dsp! Check with fstat | grep dsp if another application is holding the device open. Noteworthy troublemakers are esound and KDE's sound support. Munish Chopra Contributed by Utilizing Multiple Sound Sources It is often desirable to have multiple sources of sound that are able to play simultaneously, such as when esound or artsd do not support sharing of the sound device with a certain application. FreeBSD lets you do this through Virtual Sound Channels, which can be set with the &man.sysctl.8; facility. Virtual channels allow you to multiplex your sound card's playback channels by mixing sound in the kernel. To set the number of virtual channels, there are two sysctl knobs which, if you are the root user, can be set like this: &prompt.root; sysctl hw.snd.pcm0.vchans=4 &prompt.root; sysctl hw.snd.maxautovchans=4 The above example allocates four virtual channels, which is a practical number for everyday use. hw.snd.pcm0.vchans is the number of virtual channels pcm0 has, and is configurable once a device has been attached. hw.snd.maxautovchans is the number of virtual channels a new audio device is given when it is attached using &man.kldload.8;. Since the pcm module can be loaded independently of the hardware drivers, hw.snd.maxautovchans can store how many virtual channels any devices which are attached later will be given. If you are not using &man.devfs.5;, you will have to point your applications at /dev/dsp0.x, where x is 0 to 3 if hw.snd.pcm.0.vchans is set to 4 as in the above example. On a system using &man.devfs.5;, the above will automatically be allocated transparently to the user. Josef El-Rayes Contributed by Setting Default Values for Mixer Channels The default values for the different mixer channels are hardcoded in the sourcecode of the &man.pcm.4; driver. There are a lot of different applications and daemons that allow you to set values for the mixer they remember and set each time they are started, but this is not a clean solution, we want to have default values at the driver level. This is accomplished by defining the appropriate values in /boot/device.hints. E.g.: hint.pcm.0.vol="100" This will set the volume channel to a default value of 100, as soon as the &man.pcm.4; module gets loaded. Only &os; 5.3 and above support this. Chern Lee Contributed by MP3 Audio MP3 (MPEG Layer 3 Audio) accomplishes near CD-quality sound, leaving no reason to let your FreeBSD workstation fall short of its offerings. MP3 Players By far, the most popular &xfree86; MP3 player is XMMS (X Multimedia System). Winamp skins can be used with XMMS since the GUI is almost identical to that of Nullsoft's Winamp. XMMS also has native plug-in support. XMMS can be installed from the multimedia/xmms port or package. XMMS' interface is intuitive, with a playlist, graphic equalizer, and more. Those familiar with Winamp will find XMMS simple to use. The audio/mpg123 port is an alternative, command-line MP3 player. mpg123 can be run by specifying the sound device and the MP3 file on the command line, as shown below: &prompt.root; mpg123 -a /dev/dsp1.0 Foobar-GreatestHits.mp3 High Performance MPEG 1.0/2.0/2.5 Audio Player for Layer 1, 2 and 3. Version 0.59r (1999/Jun/15). Written and copyrights by Michael Hipp. Uses code from various people. See 'README' for more! THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK! Playing MPEG stream from Foobar-GreatestHits.mp3 ... MPEG 1.0 layer III, 128 kbit/s, 44100 Hz joint-stereo /dev/dsp1.0 should be replaced with the dsp device entry on your system. Ripping CD Audio Tracks Before encoding a CD or CD track to MP3, the audio data on the CD must be ripped onto the hard drive. This is done by copying the raw CDDA (CD Digital Audio) data to WAV files. The cdda2wav tool, which is a part of the sysutils/cdrtools suite, is used for ripping audio information from CDs and the information associated with them. With the audio CD in the drive, the following command can be issued (as root) to rip an entire CD into individual (per track) WAV files: &prompt.root; cdda2wav -D 0,1,0 -B cdda2wav will support ATAPI (IDE) CDROM drives. To rip from an IDE drive, specify the device name in place of the SCSI unit numbers. For example, to rip track 7 from an IDE drive: &prompt.root; cdda2wav -D /dev/acd0a -t 7 The indicates the SCSI device 0,1,0, which corresponds to the output of cdrecord -scanbus. To rip individual tracks, make use of the option as shown: &prompt.root; cdda2wav -D 0,1,0 -t 7 This example rips track seven of the audio CDROM. To rip a range of tracks, for example, track one to seven, specify a range: &prompt.root; cdda2wav -D 0,1,0 -t 1+7 The utility &man.dd.1; can also be used to extract audio tracks on ATAPI drives, read for more information on that possibility. Encoding MP3s Nowadays, the mp3 encoder of choice is lame. Lame can be found at audio/lame in the ports tree. Using the ripped WAV files, the following command will convert audio01.wav to audio01.mp3: &prompt.root; lame -h -b 128 \ --tt "Foo Song Title" \ --ta "FooBar Artist" \ --tl "FooBar Album" \ --ty "2001" \ --tc "Ripped and encoded by Foo" \ --tg "Genre" \ audio01.wav audio01.mp3 128 kbits seems to be the standard MP3 bitrate in use. Many enjoy the higher quality 160, or 192. The higher the bitrate, the more disk space the resulting MP3 will consume--but the quality will be higher. The option turns on the higher quality but a little slower mode. The options beginning with indicate ID3 tags, which usually contain song information, to be embedded within the MP3 file. Additional encoding options can be found by consulting the lame man page. Decoding MP3s In order to burn an audio CD from MP3s, they must be converted to a non-compressed WAV format. Both XMMS and mpg123 support the output of MP3 to an uncompressed file format. Writing to Disk in XMMS: Launch XMMS. Right-click on the window to bring up the XMMS menu. Select Preference under Options. Change the Output Plugin to Disk Writer Plugin. Press Configure. Enter (or choose browse) a directory to write the uncompressed files to. Load the MP3 file into XMMS as usual, with volume at 100% and EQ settings turned off. Press Play — XMMS will appear as if it is playing the MP3, but no music will be heard. It is actually playing the MP3 to a file. Be sure to set the default Output Plugin back to what it was before in order to listen to MP3s again. Writing to stdout in mpg123: Run mpg123 -s audio01.mp3 > audio01.pcm XMMS writes a file in the WAV format, while mpg123 converts the MP3 into raw PCM audio data. Both of these formats can be used with cdrecord to create audio CDs. You have to use raw PCM with &man.burncd.8;. If you use WAV files, you will notice a small tick sound at the beginning of each track, this sound is the header of the WAV file. You can simply remove the header of a WAV file with the utility SoX (it can be installed from the audio/sox port or package): &prompt.user; sox -t wav -r 44100 -s -w -c 2 track.wav track.raw Read for more information on using a CD burner in FreeBSD. Ross Lippert Contributed by Video Playback Video playback is a very new and rapidly developing application area. Be patient. Not everything is going to work as smoothly as it did with sound. Before you begin, you should know the model of the video card you have and the chip it uses. While &xorg; and &xfree86; support a wide variety of video cards, fewer give good playback performance. To obtain a list of extensions supported by the X server using your card use the command &man.xdpyinfo.1; while X11 is running. It is a good idea to have a short MPEG file which can be treated as a test file for evaluating various players and options. Since some DVD players will look for DVD media in /dev/dvd by default, or have this device name hardcoded in them, you might find it useful to make symbolic links to the proper devices: &prompt.root; ln -sf /dev/acd0c /dev/dvd &prompt.root; ln -sf /dev/racd0c /dev/rdvd On FreeBSD 5.X, which uses &man.devfs.5; there is a slightly different set of recommended links: &prompt.root; ln -sf /dev/acd0 /dev/dvd &prompt.root; ln -sf /dev/acd0 /dev/rdvd Note that due to the nature of &man.devfs.5;, manually created links like these will not persist if you reboot your system. In order to create the symbolic links automatically whenever you boot your system, add the following lines to /etc/devfs.conf: link acd0 dvd link acd0 rdvd Additionally, DVD decryption, which requires invoking special DVD-ROM functions, requires write permission on the DVD devices. kernel options options CPU_ENABLE_SSE kernel options options USER_LDT Some of the ports discussed rely on the following kernel options to build correctly. Before attempting to build, add these options to the kernel configuration file, build a new kernel, and reboot: option CPU_ENABLE_SSE option USER_LDT option USER_LDT does not exist on &os; 5.X. To enhance the shared memory X11 interface, it is recommended that the values of some &man.sysctl.8; variables should be increased: kern.ipc.shmmax=67108864 kern.ipc.shmall=32768 Determining Video Capabilities XVideo SDL DGA There are several possible ways to display video under X11. What will really work is largely hardware dependent. Each method described below will have varying quality across different hardware. Secondly, the rendering of video in X11 is a topic receiving a lot of attention lately, and with each version of &xorg;, or of &xfree86;, there may be significant improvement. A list of common video interfaces: X11: normal X11 output using shared memory. XVideo: an extension to the X11 interface which supports video in any X11 drawable. SDL: the Simple Directmedia Layer. DGA: the Direct Graphics Access. SVGAlib: low level console graphics layer. XVideo &xorg; and &xfree86; 4.X have an extension called XVideo (aka Xvideo, aka Xv, aka xv) which allows video to be directly displayed in drawable objects through a special acceleration. This extension provides very good quality playback even on low-end machines. To check whether the extension is running, use xvinfo: &prompt.user; xvinfo XVideo is supported for your card if the result looks like: X-Video Extension version 2.2 screen #0 Adaptor #0: "Savage Streams Engine" number of ports: 1 port base: 43 operations supported: PutImage supported visuals: depth 16, visualID 0x22 depth 16, visualID 0x23 number of attributes: 5 "XV_COLORKEY" (range 0 to 16777215) client settable attribute client gettable attribute (current value is 2110) "XV_BRIGHTNESS" (range -128 to 127) client settable attribute client gettable attribute (current value is 0) "XV_CONTRAST" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_SATURATION" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_HUE" (range -180 to 180) client settable attribute client gettable attribute (current value is 0) maximum XvImage size: 1024 x 1024 Number of image formats: 7 id: 0x32595559 (YUY2) guid: 59555932-0000-0010-8000-00aa00389b71 bits per pixel: 16 number of planes: 1 type: YUV (packed) id: 0x32315659 (YV12) guid: 59563132-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x30323449 (I420) guid: 49343230-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x36315652 (RV16) guid: 52563135-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x3e0, 0x7c00 id: 0x35315652 (RV15) guid: 52563136-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x7e0, 0xf800 id: 0x31313259 (Y211) guid: 59323131-0000-0010-8000-00aa00389b71 bits per pixel: 6 number of planes: 3 type: YUV (packed) id: 0x0 guid: 00000000-0000-0000-0000-000000000000 bits per pixel: 0 number of planes: 0 type: RGB (packed) depth: 1 red, green, blue masks: 0x0, 0x0, 0x0 Also note that the formats listed (YUV2, YUV12, etc) are not present with every implementation of XVideo and their absence may hinder some players. If the result looks like: X-Video Extension version 2.2 screen #0 no adaptors present Then XVideo is probably not supported for your card. If XVideo is not supported for your card, this only means that it will be more difficult for your display to meet the computational demands of rendering video. Depending on your video card and processor, though, you might still be able to have a satisfying experience. You should probably read about ways of improving performance in the advanced reading . Simple Directmedia Layer The Simple Directmedia Layer, SDL, was intended to be a porting layer between µsoft.windows;, BeOS, and &unix;, allowing cross-platform applications to be developed which made efficient use of sound and graphics. The SDL layer provides a low-level abstraction to the hardware which can sometimes be more efficient than the X11 interface. The SDL can be found at devel/sdl12. Direct Graphics Access Direct Graphics Access is an &xfree86; extension which allows a program to bypass the X server and directly alter the framebuffer. Because it relies on a low level memory mapping to effect this sharing, programs using it must be run as root. The DGA extension can be tested and benchmarked by &man.dga.1;. When dga is running, it changes the colors of the display whenever a key is pressed. To quit, use q. Ports and Packages Dealing with Video video ports video packages This section discusses the software available from the FreeBSD Ports Collection which can be used for video playback. Video playback is a very active area of software development, and the capabilities of various applications are bound to diverge somewhat from the descriptions given here. Firstly, it is important to know that many of the video applications which run on FreeBSD were developed as Linux applications. Many of these applications are still beta-quality. Some of the problems that you may encounter with video packages on FreeBSD include: An application cannot playback a file which another application produced. An application cannot playback a file which the application itself produced. The same application on two different machines, rebuilt on each machine for that machine, plays back the same file differently. A seemingly trivial filter like rescaling of the image size results in very bad artifacts from a buggy rescaling routine. An application frequently dumps core. Documentation is not installed with the port and can be - found either on the web or under the port's work + found either on the web or under the port's work directory. Many of these applications may also exhibit Linux-isms. That is, there may be issues resulting from the way some standard libraries are implemented in the Linux distributions, or some features of the Linux kernel which have been assumed by the authors of the applications. These issues are not always noticed and worked around by the port maintainers, which can lead to problems like these: The use of /proc/cpuinfo to detect processor characteristics. A misuse of threads which causes a program to hang upon completion instead of truly terminating. Software not yet in the FreeBSD Ports Collection which is commonly used in conjunction with the application. So far, these application developers have been cooperative with port maintainers to minimize the work-arounds needed for port-ing. MPlayer MPlayer is a recently developed and rapidly developing video player. The goals of the MPlayer team are speed and flexibility on Linux and other Unices. The project was started when the team founder got fed up with bad playback performance on then available players. Some would say that the graphical interface has been sacrificed for a streamlined design. However, once you get used to the command line options and the key-stroke controls, it works very well. Building MPlayer MPlayer making MPlayer resides in multimedia/mplayer. MPlayer performs a variety of hardware checks during the build process, resulting in a binary which will not be portable from one system to another. Therefore, it is important to build it from ports and not to use a binary package. Additionally, a number of options can be specified in the make command line, as described in the Makefile and at the start of the build: &prompt.root; cd /usr/ports/multimedia/mplayer &prompt.root; make N - O - T - E Take a careful look into the Makefile in order to learn how to tune mplayer towards you personal preferences! For example, make WITH_GTK1 builds MPlayer with GTK1-GUI support. If you want to use the GUI, you can either install /usr/ports/multimedia/mplayer-skins or download official skin collections from http://www.mplayerhq.hu/homepage/dload.html The default port options should be sufficient for most users. However, if you need the XviD codec, you have to specify the WITH_XVID option in the command line. The default DVD device can also be defined with the WITH_DVD_DEVICE option, by default /dev/acd0 will be used. As of this writing, the MPlayer port will build its HTML documentation and two executables, mplayer, and mencoder, which is a tool for re-encoding video. The HTML documentation for MPlayer is very informative. If the reader finds the information on video hardware and interfaces in this chapter lacking, the MPlayer documentation is a very thorough supplement. You should definitely take the time to read the MPlayer documentation if you are looking for information about video support in &unix;. Using MPlayer MPlayer use Any user of MPlayer must set up a .mplayer subdirectory of her home directory. To create this necessary subdirectory, you can type the following: &prompt.user; cd /usr/ports/multimedia/mplayer &prompt.user; make install-user The command options for mplayer are listed in the manual page. For even more detail there is HTML documentation. In this section, we will describe only a few common uses. To play a file, such as testfile.avi, through one of the various video interfaces set the option: &prompt.user; mplayer -vo xv testfile.avi &prompt.user; mplayer -vo sdl testfile.avi &prompt.user; mplayer -vo x11 testfile.avi &prompt.root; mplayer -vo dga testfile.avi &prompt.root; mplayer -vo 'sdl:dga' testfile.avi It is worth trying all of these options, as their relative performance depends on many factors and will vary significantly with hardware. To play from a DVD, replace the testfile.avi with where N is the title number to play and DEVICE is the device node for the DVD-ROM. For example, to play title 3 from /dev/dvd: &prompt.root; mplayer -vo xv dvd://3 -dvd-device /dev/dvd The default DVD device can be defined during the build of the MPlayer port via the WITH_DVD_DEVICE option. By default, this device is /dev/acd0. More details can be found in the port Makefile. To stop, pause, advance and so on, consult the keybindings, which are output by running mplayer -h or read the manual page. Additional important options for playback are: which engages the fullscreen mode and which helps performance. In order for the mplayer command line to not become too large, the user can create a file .mplayer/config and set default options there: vo=xv fs=yes zoom=yes Finally, mplayer can be used to rip a DVD title into a .vob file. To dump out the second title from a DVD, type this: &prompt.root; mplayer -dumpstream -dumpfile out.vob dvd://2 -dvd-device /dev/dvd The output file, out.vob, will be MPEG and can be manipulated by the other packages described in this section. mencoder mencoder Before using mencoder it is a good idea to familiarize yourself with the options from the HTML documentation. There is a manual page, but it is not very useful without the HTML documentation. There are innumerable ways to improve quality, lower bitrate, and change formats, and some of these tricks may make the difference between good or bad performance. Here are a couple of examples to get you going. First a simple copy: &prompt.user; mencoder input.avi -oac copy -ovc copy -o output.avi Improper combinations of command line options can yield output files that are unplayable even by mplayer. Thus, if you just want to rip to a file, stick to the in mplayer. To convert input.avi to the MPEG4 codec with MPEG3 audio encoding (audio/lame is required): &prompt.user; mencoder input.avi -oac mp3lame -lameopts br=192 \ -ovc lavc -lavcopts vcodec=mpeg4:vhq -o output.avi This has produced output playable by mplayer and xine. input.avi can be replaced with and run as root to re-encode a DVD title directly. Since you are likely to be dissatisfied with your results the first time around, it is recommended you dump the title to a file and work on the file. The xine Video Player The xine video player is a project of wide scope aiming not only at being an all in one video solution, but also in producing a reusable base library and a modular executable which can be extended with plugins. It comes both as a package and as a port, multimedia/xine. The xine player is still very rough around the edges, but it is clearly off to a good start. In practice, xine requires either a fast CPU with a fast video card, or support for the XVideo extension. The GUI is usable, but a bit clumsy. As of this writing, there is no input module shipped with xine which will play CSS encoded DVD's. There are third party builds which do have modules for this built in them, but none of these are in the FreeBSD Ports Collection. Compared to MPlayer, xine does more for the user, but at the same time, takes some of the more fine-grained control away from the user. The xine video player performs best on XVideo interfaces. By default, xine player will start up in a graphical user interface. The menus can then be used to open a specific file: &prompt.user; xine Alternatively, it may be invoked to play a file immediately without the GUI with the command: &prompt.user; xine -g -p mymovie.avi The transcode Utilities The software transcode is not a player, but a suite of tools for re-encoding .avi and .mpg files. With transcode, one has the ability to merge video files, repair broken files, using command line tools with stdin/stdout stream interfaces. Like MPlayer, transcode is very experimental software which must be build from the port multimedia/transcode. Using a great many options to the make command. We recommend: &prompt.root; make WITH_LIBMPEG2=yes If you plan to install multimedia/avifile, then add the WITH_AVIFILE option to your make command line, as shown here: &prompt.root; make WITH_AVIFILE=yes WITH_LIBMPEG2=yes Here are two examples of using transcode for video conversion which produce rescaled output. The first encodes the output to an openDIVX AVI file, while the second encodes to the much more portable MPEG format. &prompt.user; transcode -i input.vob -x vob -V -Z 320x240 \ -y opendivx -N 0x55 -o output.avi &prompt.user; transcode -i input.vob -x vob -V -Z 320x240 \ -y mpeg -N 0x55 -o output.tmp &prompt.user; tcmplex -o output.mpg -i output.tmp.m1v -p output.tmp.mpa -m 1 There is a manual page for transcode, but there is little documentation for the various tc* utilities (such as tcmplex) which are also installed. However, the command line option can always be given to get curt usage instructions for a command. In comparison, transcode runs significantly slower than mencoder, but it has a better chance of producing a more widely playable file. MPEGs created by transcode have been known to play on &windows.media; Player and Apple's &quicktime;, for example. Further Reading The various video software packages for FreeBSD are developing rapidly. It is quite possible that in the near future many of the problems discussed here will have been resolved. In the mean time, those who want to get the very most out of FreeBSD's A/V capabilities will have to cobble together knowledge from several FAQs and tutorials and use a few different applications. This section exists to give the reader pointers to such additional information. The MPlayer documentation is very technically informative. These documents should probably be consulted by anyone wishing to obtain a high level of expertise with &unix; video. The MPlayer mailing list is hostile to anyone who has not bothered to read the documentation, so if you plan on making bug reports to them, RTFM. The xine HOWTO contains a chapter on performance improvement which is general to all players. Finally, there are some other promising applications which the reader may try: Avifile which is also a port multimedia/avifile. Ogle which is also a port multimedia/ogle. Xtheater multimedia/dvdauthor, an open source package for authoring DVD content. Josef El-Rayes Original contribution by Marc Fonvieille Enhanced and adapted by Setting Up TV Cards TV cards Introduction TV cards allow you to watch broadcast or cable TV on your computer. Most of them accept composite video via an RCA or S-video input and some of these cards come with a FM radio tuner. &os; provides support for PCI-based TV cards using a Brooktree Bt848/849/878/879 or a Conexant CN-878/Fusion 878a Video Capture Chip with the &man.bktr.4; driver. You must also ensure the board comes with a supported tuner, consult the &man.bktr.4; manual page for a list of supported tuners. Adding the Driver To use your card, you will need to load the &man.bktr.4; driver, this can be done by adding the following line to the /boot/loader.conf file like this: bktr_load="YES" Alternatively, you may statically compile the support for the TV card in your kernel, in that case add the following lines to your kernel configuration: device bktr device iicbus device iicbb device smbus These additional device drivers are necessary because of the card components being interconnected via an I2C bus. Then build and install a new kernel. Once the support was added to your system, you have to reboot your machine. During the boot process, your TV card should show up, like this: bktr0: <BrookTree 848A> mem 0xd7000000-0xd7000fff irq 10 at device 10.0 on pci0 iicbb0: <I2C bit-banging driver> on bti2c0 iicbus0: <Philips I2C bus> on iicbb0 master-only iicbus1: <Philips I2C bus> on iicbb0 master-only smbus0: <System Management Bus> on bti2c0 bktr0: Pinnacle/Miro TV, Philips SECAM tuner. Of course these messages can differ according to your hardware. However you should check if the tuner is correctly detected; it is still possible to override some of the detected parameters with &man.sysctl.8; MIBs and kernel configuration file options. For example, if you want to force the tuner to a Philips SECAM tuner, you should add the following line to your kernel configuration file: options OVERRIDE_TUNER=6 or you can directly use &man.sysctl.8;: &prompt.root; sysctl hw.bt848.tuner=6 See the &man.bktr.4; manual page and the /usr/src/sys/conf/NOTES file for more details on the available options. (If you are under &os; 4.X, /usr/src/sys/conf/NOTES is replaced with /usr/src/sys/i386/conf/LINT.) Useful Applications To use your TV card you need to install one of the following applications: multimedia/fxtv provides TV-in-a-window and image/audio/video capture capabilities. multimedia/xawtv is also a TV application, with the same features as fxtv. misc/alevt decodes and displays Videotext/Teletext. audio/xmradio, an application to use the FM radio tuner coming with some TV cards. audio/wmtune, a handy desktop application for radio tuners. More applications are available in the &os; Ports Collection. Troubleshooting If you encounter any problem with your TV card, you should check at first if the video capture chip and the tuner are really supported by the &man.bktr.4; driver and if you used the right configuration options. For more support and various questions about your TV card you may want to contact and use the archives of the &a.multimedia.name; mailing list. Marc Fonvieille Written by Image Scanners image scanners Introduction &os;, like any modern operating system, allows the use of image scanners. Standardized access to scanners is provided by the SANE (Scanner Access Now Easy) API available through the &os; Ports Collection. SANE will also use some &os; devices drivers to access to the scanner hardware. &os; supports both SCSI and USB scanners. Be sure your scanner is supported by SANE prior to performing any configuration. SANE has a supported devices list that can provide you with information about the support for a scanner and its status. The &man.uscanner.4; manual page also provides a list of supported USB scanners. Kernel Configuration As mentioned above both SCSI and USB interfaces are supported. According to your scanner interface, different device drivers are required. USB Interface The GENERIC kernel by default includes the device drivers needed to support USB scanners. Should you decide to use a custom kernel, be sure that the following lines are present in your kernel configuration file: device usb device uhci device ohci device uscanner Depending upon the USB chipset on your motherboard, you will only need either device uhci or device ohci, however having both in the kernel configuration file is harmless. If you do not want to rebuild your kernel and your kernel is not the GENERIC one, you can directly load the &man.uscanner.4; device driver module with the &man.kldload.8; command: &prompt.root; kldload uscanner To load this module at each system startup, add the following line to /boot/loader.conf: uscanner_load="YES" After rebooting with the correct kernel, or after loading the required module, plug in your USB scanner. The scanner should appear in your system message buffer (&man.dmesg.8;) as something like: uscanner0: EPSON EPSON Scanner, rev 1.10/3.02, addr 2 This shows that our scanner is using the /dev/uscanner0 device node. On &os; 4.X, the USB daemon (&man.usbd.8;) must be running to be able to see some USB devices. To enable this, add usbd_enable="YES" to your /etc/rc.conf file and reboot the machine. SCSI Interface If your scanner comes with a SCSI interface, it is important to know which SCSI controller board you will use. According to the SCSI chipset used, you will have to tune your kernel configuration file. The GENERIC kernel supports the most common SCSI controllers. Be sure to read the NOTES file (LINT under &os; 4.X) and add the correct line to your kernel configuration file. In addition to the SCSI adapter driver, you need to have the following lines in your kernel configuration file: device scbus device pass Once your kernel has been properly compiled, you should be able to see the devices in your system message buffer, when booting: pass2 at aic0 bus 0 target 2 lun 0 pass2: <AGFA SNAPSCAN 600 1.10> Fixed Scanner SCSI-2 device pass2: 3.300MB/s transfers If your scanner was not powered-on at system boot, it is still possible to manually force the detection by performing a SCSI bus scan with the &man.camcontrol.8; command: &prompt.root; camcontrol rescan all Re-scan of bus 0 was successful Re-scan of bus 1 was successful Re-scan of bus 2 was successful Re-scan of bus 3 was successful Then the scanner will appear in the SCSI devices list: &prompt.root; camcontrol devlist <IBM DDRS-34560 S97B> at scbus0 target 5 lun 0 (pass0,da0) <IBM DDRS-34560 S97B> at scbus0 target 6 lun 0 (pass1,da1) <AGFA SNAPSCAN 600 1.10> at scbus1 target 2 lun 0 (pass3) <PHILIPS CDD3610 CD-R/RW 1.00> at scbus2 target 0 lun 0 (pass2,cd0) More details about SCSI devices, are available in the &man.scsi.4; and &man.camcontrol.8; manual pages. SANE Configuration The SANE system has been splitted in two parts: the backends (graphics/sane-backends) and the frontends (graphics/sane-frontends). The backends part provides access to the scanner itself. The SANE's supported devices list specifies which backend will support your image scanner. It is mandatory to determine the correct backend for your scanner if you want to be able to use your device. The frontends part provides the graphical scanning interface (xscanimage). The first thing to do is install the graphics/sane-backends port or package. Then, use the sane-find-scanner command to check the scanner detection by the SANE system: &prompt.root; sane-find-scanner -q found SCSI scanner "AGFA SNAPSCAN 600 1.10" at /dev/pass3 The output will show the interface type of the scanner and the device node used to attach the scanner to the system. The vendor and the product model may not appear, it is not important. Some USB scanners require you to load a firmware, this is explained in the backend manual page. You should also read &man.sane-find-scanner.1; and &man.sane.7; manual pages. Now we have to check if the scanner will be identified by a scanning frontend. By default, the SANE backends comes with a command line tool called &man.scanimage.1;. This command allows you to list the devices and to perform an image acquisition from the command line. The option is used to list the scanner device: &prompt.root; scanimage -L device `snapscan:/dev/pass3' is a AGFA SNAPSCAN 600 flatbed scanner No output or a message saying that no scanners were identified indicates that &man.scanimage.1; is unable to identify the scanner. If this happens, you will need to edit the backend configuration file and define the scanner device used. The /usr/local/etc/sane.d/ directory + class="directory">/usr/local/etc/sane.d/ directory contains all backends configuration files. This identification problem does appear with certain USB scanners. For example, with the USB scanner used in the , sane-find-scanner gives us the following information: &prompt.root; sane-find-scanner -q found USB scanner (UNKNOWN vendor and product) at device /dev/uscanner0 The scanner is correctly detected, it uses the USB interface and is attached to the /dev/uscanner0 device node. We can now check if the scanner is correctly identified: &prompt.root; scanimage -L No scanners were identified. If you were expecting something different, check that the scanner is plugged in, turned on and detected by the sane-find-scanner tool (if appropriate). Please read the documentation which came with this software (README, FAQ, manpages). Since the scanner is not identified, we will need to edit the /usr/local/etc/sane.d/epson.conf file. The scanner model used was the &epson.perfection; 1650, so we know the scanner will use the epson backend. Be sure to read the help comments in the backends configuration files. Line changes are quite simple: comment out all lines that have the wrong interface for your scanner (in our case, we will comment out all lines starting with the word scsi as our scanner uses the USB interface), then add at the end of the file a line specifying the interface and the device node used. In this case, we add the following line: usb /dev/uscanner0 Please be sure to read the comments provided in the backend configuration file as well as the backend manual page for more details and correct syntax to use. We can now verify if the scanner is identified: &prompt.root; scanimage -L device `epson:/dev/uscanner0' is a Epson GT-8200 flatbed scanner Our USB scanner has been identified. It is not important if the brand and the model do not match. The key item to be concerned with is the `epson:/dev/uscanner0' field, which give us the right backend name and the right device node. Once the scanimage -L command is able to see the scanner, the configuration is complete. The device is now ready to scan. While &man.scanimage.1; does allow us to perform an image acquisition from the command line, it is preferable to use a graphical user interface to perform image scanning. SANE offers a simple but efficient graphical interface: xscanimage (graphics/sane-frontends). Xsane (graphics/xsane) is another popular graphical scanning frontend. This frontend offers advanced features such as various scanning mode (photocopy, fax, etc.), color correction, batch scans, etc. Both of these applications are useable as a GIMP plugin. Allowing Scanner Access to Other Users All previous operations have been done with root privileges. You may however, need other users to have access to the scanner. The user will need read and write permissions to the device node used by the scanner. As an example, our USB scanner uses the device node /dev/uscanner0 which is owned by the operator group. Adding the user joe to the operator group will allow him to use the scanner: &prompt.root; pw groupmod operator -m joe For more details read the &man.pw.8; manual page. You also have to set the correct write permissions (0660 or 0664) on the /dev/uscanner0 device node, by default the operator group can only read the device node. This is done by adding the following lines to the /etc/devfs.rules file: [system=5] add path uscanner0 mode 660 Then add the following to /etc/rc.conf and reboot the machine: devfs_system_ruleset="system" More information regarding these lines can be found in the &man.devfs.8; manual page. Under &os; 4.X, the operator group has, by default, read and write permissions to /dev/uscanner0. Of course, for security reasons, you should think twice before adding a user to any group, especially the operator group. diff --git a/en_US.ISO8859-1/books/handbook/network-servers/chapter.sgml b/en_US.ISO8859-1/books/handbook/network-servers/chapter.sgml index 5bab973287..5a293d6a85 100644 --- a/en_US.ISO8859-1/books/handbook/network-servers/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/network-servers/chapter.sgml @@ -1,5099 +1,5099 @@ Murray Stokely Reorganized by Network Servers Synopsis This chapter will cover some of the more frequently used network services on &unix; systems. We will cover how to install, configure, test, and maintain many different types of network services. Example configuration files are included throughout this chapter for you to benefit from. After reading this chapter, you will know: How to manage the inetd daemon. How to set up a network filesystem. How to set up a network information server for sharing user accounts. How to set up automatic network settings using DHCP. How to set up a domain name server. How to set up the Apache HTTP Server. How to set up a File Transfer Protocol (FTP) Server. How to set up a file and print server for &windows; clients using Samba. How to synchronize the time and date, and set up a time server, with the NTP protocol. Before reading this chapter, you should: Understand the basics of the /etc/rc scripts. Be familiar with basic network terminology. Know how to install additional third-party software (). Chern Lee Contributed by The <application>inetd</application> <quote>Super-Server</quote> Overview &man.inetd.8; is referred to as the Internet Super-Server because it manages connections for several services. When a connection is received by inetd, it determines which program the connection is destined for, spawns the particular process and delegates the socket to it (the program is invoked with the service socket as its standard input, output and error descriptors). Running one instance of inetd reduces the overall system load as compared to running each daemon individually in stand-alone mode. Primarily, inetd is used to spawn other daemons, but several trivial protocols are handled directly, such as chargen, auth, and daytime. This section will cover the basics in configuring inetd through its command-line options and its configuration file, /etc/inetd.conf. Settings inetd is initialized through the /etc/rc.conf system. The inetd_enable option is set to NO by default, but is often times turned on by sysinstall with the medium security profile. Placing: inetd_enable="YES" or inetd_enable="NO" into /etc/rc.conf can enable or disable inetd starting at boot time. Additionally, different command-line options can be passed to inetd via the inetd_flags option. Command-Line Options inetd synopsis: -d Turn on debugging. -l Turn on logging of successful connections. -w Turn on TCP Wrapping for external services (on by default). -W Turn on TCP Wrapping for internal services which are built into inetd (on by default). -c maximum Specify the default maximum number of simultaneous invocations of each service; the default is unlimited. May be overridden on a per-service basis with the parameter. -C rate Specify the default maximum number of times a service can be invoked from a single IP address in one minute; the default is unlimited. May be overridden on a per-service basis with the parameter. -R rate Specify the maximum number of times a service can be invoked in one minute; the default is 256. A rate of 0 allows an unlimited number of invocations. -a Specify one specific IP address to bind to. Alternatively, a hostname can be specified, in which case the IPv4 or IPv6 address which corresponds to that hostname is used. Usually a hostname is specified when inetd is run inside a &man.jail.8;, in which case the hostname corresponds to the &man.jail.8; environment. When hostname specification is used and both IPv4 and IPv6 bindings are desired, one entry with the appropriate protocol type for each binding is required for each service in /etc/inetd.conf. For example, a TCP-based service would need two entries, one using tcp4 for the protocol and the other using tcp6. -p Specify an alternate file in which to store the process ID. These options can be passed to inetd using the inetd_flags option in /etc/rc.conf. By default, inetd_flags is set to -wW, which turns on TCP wrapping for inetd's internal and external services. For novice users, these parameters usually do not need to be modified or even entered in /etc/rc.conf. An external service is a daemon outside of inetd, which is invoked when a connection is received for it. On the other hand, an internal service is one that inetd has the facility of offering within itself. <filename>inetd.conf</filename> Configuration of inetd is controlled through the /etc/inetd.conf file. When a modification is made to /etc/inetd.conf, inetd can be forced to re-read its configuration file by sending a HangUP signal to the inetd process as shown: Sending <application>inetd</application> a HangUP Signal &prompt.root; kill -HUP `cat /var/run/inetd.pid` Each line of the configuration file specifies an individual daemon. Comments in the file are preceded by a #. The format of /etc/inetd.conf is as follows: service-name socket-type protocol {wait|nowait}[/max-child[/max-connections-per-ip-per-minute]] user[:group][/login-class] server-program server-program-arguments An example entry for the ftpd daemon using IPv4: ftp stream tcp nowait root /usr/libexec/ftpd ftpd -l service-name This is the service name of the particular daemon. It must correspond to a service listed in /etc/services. This determines which port inetd must listen to. If a new service is being created, it must be placed in /etc/services first. socket-type Either stream, dgram, raw, or seqpacket. stream must be used for connection-based, TCP daemons, while dgram is used for daemons utilizing the UDP transport protocol. protocol One of the following: Protocol Explanation tcp, tcp4 TCP IPv4 udp, udp4 UDP IPv4 tcp6 TCP IPv6 udp6 UDP IPv6 tcp46 Both TCP IPv4 and v6 udp46 Both UDP IPv4 and v6 {wait|nowait}[/max-child[/max-connections-per-ip-per-minute]] indicates whether the daemon invoked from inetd is able to handle its own socket or not. socket types must use the option, while stream socket daemons, which are usually multi-threaded, should use . usually hands off multiple sockets to a single daemon, while spawns a child daemon for each new socket. The maximum number of child daemons inetd may spawn can be set using the option. If a limit of ten instances of a particular daemon is needed, a /10 would be placed after . In addition to , another option limiting the maximum connections from a single place to a particular daemon can be enabled. does just this. A value of ten here would limit any particular IP address connecting to a particular service to ten attempts per minute. This is useful to prevent intentional or unintentional resource consumption and Denial of Service (DoS) attacks to a machine. In this field, or is mandatory. and are optional. A stream-type multi-threaded daemon without any or limits would simply be: nowait. The same daemon with a maximum limit of ten daemons would read: nowait/10. Additionally, the same setup with a limit of twenty connections per IP address per minute and a maximum total limit of ten child daemons would read: nowait/10/20. These options are all utilized by the default settings of the fingerd daemon, as seen here: finger stream tcp nowait/3/10 nobody /usr/libexec/fingerd fingerd -s user This is the username that the particular daemon should run as. Most commonly, daemons run as the root user. For security purposes, it is common to find some servers running as the daemon user, or the least privileged nobody user. server-program The full path of the daemon to be executed when a connection is received. If the daemon is a service provided by inetd internally, then should be used. server-program-arguments This works in conjunction with by specifying the arguments, starting with argv[0], passed to the daemon on invocation. If mydaemon -d is the command line, mydaemon -d would be the value of . Again, if the daemon is an internal service, use here. Security Depending on the security profile chosen at install, many of inetd's daemons may be enabled by default. If there is no apparent need for a particular daemon, disable it! Place a # in front of the daemon in question in /etc/inetd.conf, and then send a hangup signal to inetd. Some daemons, such as fingerd, may not be desired at all because they provide an attacker with too much information. Some daemons are not security-conscious and have long, or non-existent timeouts for connection attempts. This allows an attacker to slowly send connections to a particular daemon, thus saturating available resources. It may be a good idea to place and limitations on certain daemons. By default, TCP wrapping is turned on. Consult the &man.hosts.access.5; manual page for more information on placing TCP restrictions on various inetd invoked daemons. Miscellaneous daytime, time, echo, discard, chargen, and auth are all internally provided services of inetd. The auth service provides identity (ident, identd) network services, and is configurable to a certain degree. Consult the &man.inetd.8; manual page for more in-depth information. Tom Rhodes Reorganized and enhanced by Bill Swingle Written by Network File System (NFS) NFS Among the many different filesystems that FreeBSD supports is the Network File System, also known as NFS. NFS allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files. Some of the most notable benefits that NFS can provide are: Local workstations use less disk space because commonly used data can be stored on a single machine and still remain accessible to others over the network. There is no need for users to have separate home directories on every network machine. Home directories could be set up on the NFS server and made available throughout the network. Storage devices such as floppy disks, CDROM drives, and &iomegazip; drives can be used by other machines on the network. This may reduce the number of removable media drives throughout the network. How <acronym>NFS</acronym> Works NFS consists of at least two main parts: a server and one or more clients. The client remotely accesses the data that is stored on the server machine. In order for this to function properly a few processes have to be configured and running. In &os; 5.X, the portmap utility has been replaced with the rpcbind utility. Thus, in &os; 5.X the user is required to replace every instance of portmap with rpcbind in the forthcoming examples. The server has to be running the following daemons: NFS server file server unix clients portmap mountd nfsd Daemon Description nfsd The NFS daemon which services requests from the NFS clients. mountd The NFS mount daemon which carries out the requests that &man.nfsd.8; passes on to it. portmap The portmapper daemon allows NFS clients to discover which port the NFS server is using. The client can also run a daemon, known as nfsiod. The nfsiod daemon services the requests from the NFS server. This is optional, and improves performance, but is not required for normal and correct operation. See the &man.nfsiod.8; manual page for more information. Configuring <acronym>NFS</acronym> NFS configuration NFS configuration is a relatively straightforward process. The processes that need to be running can all start at boot time with a few modifications to your /etc/rc.conf file. On the NFS server, make sure that the following options are configured in the /etc/rc.conf file: portmap_enable="YES" nfs_server_enable="YES" mountd_flags="-r" mountd runs automatically whenever the NFS server is enabled. On the client, make sure this option is present in /etc/rc.conf: nfs_client_enable="YES" The /etc/exports file specifies which filesystems NFS should export (sometimes referred to as share). Each line in /etc/exports specifies a filesystem to be exported and which machines have access to that filesystem. Along with what machines have access to that filesystem, access options may also be specified. There are many such options that can be used in this file but only a few will be mentioned here. You can easily discover other options by reading over the &man.exports.5; manual page. Here are a few example /etc/exports entries: NFS export examples The following examples give an idea of how to export filesystems, although the settings may be different depending on your environment and network configuration. For instance, to export the /cdrom directory to three example machines that have the same domain name as the server (hence the lack of a domain name for each) or have entries in your /etc/hosts file. The flag makes the exported filesystem read-only. With this flag, the remote system will not be able to write any changes to the exported filesystem. /cdrom -ro host1 host2 host3 The following line exports /home to three hosts by IP address. This is a useful setup if you have a private network without a DNS server configured. Optionally the /etc/hosts file could be configured for internal hostnames; please review &man.hosts.5; for more information. The flag allows the subdirectories to be mount points. In other words, it will not mount the subdirectories but permit the client to mount only the directories that are required or needed. /home -alldirs 10.0.0.2 10.0.0.3 10.0.0.4 The following line exports /a so that two clients from different domains may access the filesystem. The flag allows the root user on the remote system to write data on the exported filesystem as root. If the -maproot=root flag is not specified, then even if a user has root access on the remote system, he will not be able to modify files on the exported filesystem. /a -maproot=root host.example.com box.example.org In order for a client to access an exported filesystem, the client must have permission to do so. Make sure the client is listed in your /etc/exports file. In /etc/exports, each line represents the export information for one filesystem to one host. A remote host can only be specified once per filesystem, and may only have one default entry. For example, assume that /usr is a single filesystem. The following /etc/exports would be invalid: /usr/src client /usr/ports client One filesystem, /usr, has two lines specifying exports to the same host, client. The correct format for this situation is: /usr/src /usr/ports client The properties of one filesystem exported to a given host must all occur on one line. Lines without a client specified are treated as a single host. This limits how you can export filesystems, but for most people this is not an issue. The following is an example of a valid export list, where /usr and /exports are local filesystems: # Export src and ports to client01 and client02, but only # client01 has root privileges on it /usr/src /usr/ports -maproot=root client01 /usr/src /usr/ports client02 # The client machines have root and can mount anywhere # on /exports. Anyone in the world can mount /exports/obj read-only /exports -alldirs -maproot=root client01 client02 /exports/obj -ro You must restart mountd whenever you modify /etc/exports so the changes can take effect. This can be accomplished by sending the HUP signal to the mountd process: &prompt.root; kill -HUP `cat /var/run/mountd.pid` Alternatively, a reboot will make FreeBSD set everything up properly. A reboot is not necessary though. Executing the following commands as root should start everything up. On the NFS server: &prompt.root; portmap &prompt.root; nfsd -u -t -n 4 &prompt.root; mountd -r On the NFS client: &prompt.root; nfsiod -n 4 Now everything should be ready to actually mount a remote file system. In these examples the server's name will be server and the client's name will be client. If you only want to temporarily mount a remote filesystem or would rather test the configuration, just execute a command like this as root on the client: NFS mounting &prompt.root; mount server:/home /mnt This will mount the /home directory on the server at /mnt on the client. If everything is set up correctly you should be able to enter /mnt on the client and see all the files that are on the server. If you want to automatically mount a remote filesystem each time the computer boots, add the filesystem to the /etc/fstab file. Here is an example: server:/home /mnt nfs rw 0 0 The &man.fstab.5; manual page lists all the available options. Practical Uses NFS has many practical uses. Some of the more common ones are listed below: NFS uses Set several machines to share a CDROM or other media among them. This is cheaper and often a more convenient method to install software on multiple machines. On large networks, it might be more convenient to configure a central NFS server in which to store all the user home directories. These home directories can then be exported to the network so that users would always have the same home directory, regardless of which workstation they log in to. Several machines could have a common /usr/ports/distfiles directory. That way, when you need to install a port on several machines, you can quickly access the source without downloading it on each machine. Wylie Stilwell Contributed by Chern Lee Rewritten by Automatic Mounts with <application>amd</application> amd automatic mounter daemon &man.amd.8; (the automatic mounter daemon) automatically mounts a remote filesystem whenever a file or directory within that filesystem is accessed. Filesystems that are inactive for a period of time will also be automatically unmounted by amd. Using amd provides a simple alternative to permanent mounts, as permanent mounts are usually listed in /etc/fstab. amd operates by attaching itself as an NFS server to the /host and /net directories. When a file is accessed within one of these directories, amd looks up the corresponding remote mount and automatically mounts it. /net is used to mount an exported filesystem from an IP address, while /host is used to mount an export from a remote hostname. An access to a file within /host/foobar/usr would tell amd to attempt to mount the /usr export on the host foobar. Mounting an Export with <application>amd</application> You can view the available mounts of a remote host with the showmount command. For example, to view the mounts of a host named foobar, you can use: &prompt.user; showmount -e foobar Exports list on foobar: /usr 10.10.10.0 /a 10.10.10.0 &prompt.user; cd /host/foobar/usr As seen in the example, the showmount shows /usr as an export. When changing directories to /host/foobar/usr, amd attempts to resolve the hostname foobar and automatically mount the desired export. amd can be started by the startup scripts by placing the following lines in /etc/rc.conf: amd_enable="YES" Additionally, custom flags can be passed to amd from the amd_flags option. By default, amd_flags is set to: amd_flags="-a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map" The /etc/amd.map file defines the default options that exports are mounted with. The /etc/amd.conf file defines some of the more advanced features of amd. Consult the &man.amd.8; and &man.amd.conf.5; manual pages for more information. John Lind Contributed by Problems Integrating with Other Systems Certain Ethernet adapters for ISA PC systems have limitations which can lead to serious network problems, particularly with NFS. This difficulty is not specific to FreeBSD, but FreeBSD systems are affected by it. The problem nearly always occurs when (FreeBSD) PC systems are networked with high-performance workstations, such as those made by Silicon Graphics, Inc., and Sun Microsystems, Inc. The NFS mount will work fine, and some operations may succeed, but suddenly the server will seem to become unresponsive to the client, even though requests to and from other systems continue to be processed. This happens to the client system, whether the client is the FreeBSD system or the workstation. On many systems, there is no way to shut down the client gracefully once this problem has manifested itself. The only solution is often to reset the client, because the NFS situation cannot be resolved. Though the correct solution is to get a higher performance and capacity Ethernet adapter for the FreeBSD system, there is a simple workaround that will allow satisfactory operation. If the FreeBSD system is the server, include the option on the mount from the client. If the FreeBSD system is the client, then mount the NFS filesystem with the option . These options may be specified using the fourth field of the fstab entry on the client for automatic mounts, or by using the parameter of the &man.mount.8; command for manual mounts. It should be noted that there is a different problem, sometimes mistaken for this one, when the NFS servers and clients are on different networks. If that is the case, make certain that your routers are routing the necessary UDP information, or you will not get anywhere, no matter what else you are doing. In the following examples, fastws is the host (interface) name of a high-performance workstation, and freebox is the host (interface) name of a FreeBSD system with a lower-performance Ethernet adapter. Also, /sharedfs will be the exported NFS filesystem (see &man.exports.5;), and /project will be the mount point on the client for the exported filesystem. In all cases, note that additional options, such as or and may be desirable in your application. Examples for the FreeBSD system (freebox) as the client in /etc/fstab on freebox: fastws:/sharedfs /project nfs rw,-r=1024 0 0 As a manual mount command on freebox: &prompt.root; mount -t nfs -o -r=1024 fastws:/sharedfs /project Examples for the FreeBSD system as the server in /etc/fstab on fastws: freebox:/sharedfs /project nfs rw,-w=1024 0 0 As a manual mount command on fastws: &prompt.root; mount -t nfs -o -w=1024 freebox:/sharedfs /project Nearly any 16-bit Ethernet adapter will allow operation without the above restrictions on the read or write size. For anyone who cares, here is what happens when the failure occurs, which also explains why it is unrecoverable. NFS typically works with a block size of 8 K (though it may do fragments of smaller sizes). Since the maximum Ethernet packet is around 1500 bytes, the NFS block gets split into multiple Ethernet packets, even though it is still a single unit to the upper-level code, and must be received, assembled, and acknowledged as a unit. The high-performance workstations can pump out the packets which comprise the NFS unit one right after the other, just as close together as the standard allows. On the smaller, lower capacity cards, the later packets overrun the earlier packets of the same unit before they can be transferred to the host and the unit as a whole cannot be reconstructed or acknowledged. As a result, the workstation will time out and try again, but it will try again with the entire 8 K unit, and the process will be repeated, ad infinitum. By keeping the unit size below the Ethernet packet size limitation, we ensure that any complete Ethernet packet received can be acknowledged individually, avoiding the deadlock situation. Overruns may still occur when a high-performance workstations is slamming data out to a PC system, but with the better cards, such overruns are not guaranteed on NFS units. When an overrun occurs, the units affected will be retransmitted, and there will be a fair chance that they will be received, assembled, and acknowledged. Bill Swingle Written by Eric Ogren Enhanced by Udo Erdelhoff Network Information System (NIS/YP) What Is It? NIS Solaris HP-UX AIX Linux NetBSD OpenBSD NIS, which stands for Network Information Services, was developed by Sun Microsystems to centralize administration of &unix; (originally &sunos;) systems. It has now essentially become an industry standard; all major &unix; like systems (&solaris;, HP-UX, &aix;, Linux, NetBSD, OpenBSD, FreeBSD, etc) support NIS. yellow pagesNIS NIS was formerly known as Yellow Pages, but because of trademark issues, Sun changed the name. The old term (and yp) is still often seen and used. NIS domains It is a RPC-based client/server system that allows a group of machines within an NIS domain to share a common set of configuration files. This permits a system administrator to set up NIS client systems with only minimal configuration data and add, remove or modify configuration data from a single location. Windows NT It is similar to the &windowsnt; domain system; although the internal implementation of the two are not at all similar, the basic functionality can be compared. Terms/Processes You Should Know There are several terms and several important user processes that you will come across when attempting to implement NIS on FreeBSD, whether you are trying to create an NIS server or act as an NIS client: portmap Term Description NIS domainname An NIS master server and all of its clients (including its slave servers) have a NIS domainname. Similar to an &windowsnt; domain name, the NIS domainname does not have anything to do with DNS. portmap Must be running in order to enable RPC (Remote Procedure Call, a network protocol used by NIS). If portmap is not running, it will be impossible to run an NIS server, or to act as an NIS client. ypbind Binds an NIS client to its NIS server. It will take the NIS domainname from the system, and using RPC, connect to the server. ypbind is the core of client-server communication in an NIS environment; if ypbind dies on a client machine, it will not be able to access the NIS server. ypserv Should only be running on NIS servers; this is the NIS server process itself. If &man.ypserv.8; dies, then the server will no longer be able to respond to NIS requests (hopefully, there is a slave server to take over for it). There are some implementations of NIS (but not the FreeBSD one), that do not try to reconnect to another server if the server it used before dies. Often, the only thing that helps in this case is to restart the server process (or even the whole server) or the ypbind process on the client. rpc.yppasswdd Another process that should only be running on NIS master servers; this is a daemon that will allow NIS clients to change their NIS passwords. If this daemon is not running, users will have to login to the NIS master server and change their passwords there. How Does It Work? There are three types of hosts in an NIS environment: master servers, slave servers, and clients. Servers act as a central repository for host configuration information. Master servers hold the authoritative copy of this information, while slave servers mirror this information for redundancy. Clients rely on the servers to provide this information to them. Information in many files can be shared in this manner. The master.passwd, group, and hosts files are commonly shared via NIS. Whenever a process on a client needs information that would normally be found in these files locally, it makes a query to the NIS server that it is bound to instead. Machine Types NIS master server A NIS master server. This server, analogous to a &windowsnt; primary domain controller, maintains the files used by all of the NIS clients. The passwd, group, and other various files used by the NIS clients live on the master server. It is possible for one machine to be an NIS master server for more than one NIS domain. However, this will not be covered in this introduction, which assumes a relatively small-scale NIS environment. NIS slave server NIS slave servers. Similar to the &windowsnt; backup domain controllers, NIS slave servers maintain copies of the NIS master's data files. NIS slave servers provide the redundancy, which is needed in important environments. They also help to balance the load of the master server: NIS Clients always attach to the NIS server whose response they get first, and this includes slave-server-replies. NIS client NIS clients. NIS clients, like most &windowsnt; workstations, authenticate against the NIS server (or the &windowsnt; domain controller in the &windowsnt; workstations case) to log on. Using NIS/YP This section will deal with setting up a sample NIS environment. This section assumes that you are running FreeBSD 3.3 or later. The instructions given here will probably work for any version of FreeBSD greater than 3.0, but there are no guarantees that this is true. Planning Let us assume that you are the administrator of a small university lab. This lab, which consists of 15 FreeBSD machines, currently has no centralized point of administration; each machine has its own /etc/passwd and /etc/master.passwd. These files are kept in sync with each other only through manual intervention; currently, when you add a user to the lab, you must run adduser on all 15 machines. Clearly, this has to change, so you have decided to convert the lab to use NIS, using two of the machines as servers. Therefore, the configuration of the lab now looks something like: Machine name IP address Machine role ellington 10.0.0.2 NIS master coltrane 10.0.0.3 NIS slave basie 10.0.0.4 Faculty workstation bird 10.0.0.5 Client machine cli[1-11] 10.0.0.[6-17] Other client machines If you are setting up a NIS scheme for the first time, it is a good idea to think through how you want to go about it. No matter what the size of your network, there are a few decisions that need to be made. Choosing a NIS Domain Name NIS domainname This might not be the domainname that you are used to. It is more accurately called the NIS domainname. When a client broadcasts its requests for info, it includes the name of the NIS domain that it is part of. This is how multiple servers on one network can tell which server should answer which request. Think of the NIS domainname as the name for a group of hosts that are related in some way. Some organizations choose to use their Internet domainname for their NIS domainname. This is not recommended as it can cause confusion when trying to debug network problems. The NIS domainname should be unique within your network and it is helpful if it describes the group of machines it represents. For example, the Art department at Acme Inc. might be in the acme-art NIS domain. For this example, assume you have chosen the name test-domain. SunOS However, some operating systems (notably &sunos;) use their NIS domain name as their Internet domain name. If one or more machines on your network have this restriction, you must use the Internet domain name as your NIS domain name. Physical Server Requirements There are several things to keep in mind when choosing a machine to use as a NIS server. One of the unfortunate things about NIS is the level of dependency the clients have on the server. If a client cannot contact the server for its NIS domain, very often the machine becomes unusable. The lack of user and group information causes most systems to temporarily freeze up. With this in mind you should make sure to choose a machine that will not be prone to being rebooted regularly, or one that might be used for development. The NIS server should ideally be a stand alone machine whose sole purpose in life is to be an NIS server. If you have a network that is not very heavily used, it is acceptable to put the NIS server on a machine running other services, just keep in mind that if the NIS server becomes unavailable, it will affect all of your NIS clients adversely. NIS Servers The canonical copies of all NIS information are stored on a single machine called the NIS master server. The databases used to store the information are called NIS maps. In FreeBSD, these maps are stored in /var/yp/[domainname] where [domainname] is the name of the NIS domain being served. A single NIS server can support several domains at once, therefore it is possible to have several such directories, one for each supported domain. Each domain will have its own independent set of maps. NIS master and slave servers handle all NIS requests with the ypserv daemon. ypserv is responsible for receiving incoming requests from NIS clients, translating the requested domain and map name to a path to the corresponding database file and transmitting data from the database back to the client. Setting Up a NIS Master Server NIS server configuration Setting up a master NIS server can be relatively straight forward, depending on your needs. FreeBSD comes with support for NIS out-of-the-box. All you need is to add the following lines to /etc/rc.conf, and FreeBSD will do the rest for you. nisdomainname="test-domain" This line will set the NIS domainname to test-domain upon network setup (e.g. after reboot). nis_server_enable="YES" This will tell FreeBSD to start up the NIS server processes when the networking is next brought up. nis_yppasswdd_enable="YES" This will enable the rpc.yppasswdd daemon which, as mentioned above, will allow users to change their NIS password from a client machine. Depending on your NIS setup, you may need to add further entries. See the section about NIS servers that are also NIS clients, below, for details. Now, all you have to do is to run the command /etc/netstart as superuser. It will set up everything for you, using the values you defined in /etc/rc.conf. Initializing the NIS Maps NIS maps The NIS maps are database files, that are kept in the /var/yp directory. They are generated from configuration files in the /etc directory of the NIS master, with one exception: the /etc/master.passwd file. This is for a good reason, you do not want to propagate passwords to your root and other administrative accounts to all the servers in the NIS domain. Therefore, before we initialize the NIS maps, you should: &prompt.root; cp /etc/master.passwd /var/yp/master.passwd &prompt.root; cd /var/yp &prompt.root; vi master.passwd You should remove all entries regarding system accounts (bin, tty, kmem, games, etc), as well as any accounts that you do not want to be propagated to the NIS clients (for example root and any other UID 0 (superuser) accounts). Make sure the /var/yp/master.passwd is neither group nor world readable (mode 600)! Use the chmod command, if appropriate. Tru64 UNIX When you have finished, it is time to initialize the NIS maps! FreeBSD includes a script named ypinit to do this for you (see its manual page for more information). Note that this script is available on most &unix; Operating Systems, but not on all. On Digital UNIX/Compaq Tru64 UNIX it is called ypsetup. Because we are generating maps for an NIS master, we are going to pass the option to ypinit. To generate the NIS maps, assuming you already performed the steps above, run: ellington&prompt.root; ypinit -m test-domain Server Type: MASTER Domain: test-domain Creating an YP server will require that you answer a few questions. Questions will all be asked at the beginning of the procedure. Do you want this procedure to quit on non-fatal errors? [y/n: n] n Ok, please remember to go back and redo manually whatever fails. If you don't, something might not work. At this point, we have to construct a list of this domains YP servers. rod.darktech.org is already known as master server. Please continue to add any slave servers, one per line. When you are done with the list, type a <control D>. master server : ellington next host to add: coltrane next host to add: ^D The current list of NIS servers looks like this: ellington coltrane Is this correct? [y/n: y] y [..output from map generation..] NIS Map update completed. ellington has been setup as an YP master server without any errors. ypinit should have created /var/yp/Makefile from /var/yp/Makefile.dist. When created, this file assumes that you are operating in a single server NIS environment with only FreeBSD machines. Since test-domain has a slave server as well, you must edit /var/yp/Makefile: ellington&prompt.root; vi /var/yp/Makefile You should comment out the line that says NOPUSH = "True" (if it is not commented out already). Setting up a NIS Slave Server NIS slave server Setting up an NIS slave server is even more simple than setting up the master. Log on to the slave server and edit the file /etc/rc.conf as you did before. The only difference is that we now must use the option when running ypinit. The option requires the name of the NIS master be passed to it as well, so our command line looks like: coltrane&prompt.root; ypinit -s ellington test-domain Server Type: SLAVE Domain: test-domain Master: ellington Creating an YP server will require that you answer a few questions. Questions will all be asked at the beginning of the procedure. Do you want this procedure to quit on non-fatal errors? [y/n: n] n Ok, please remember to go back and redo manually whatever fails. If you don't, something might not work. There will be no further questions. The remainder of the procedure should take a few minutes, to copy the databases from ellington. Transferring netgroup... ypxfr: Exiting: Map successfully transferred Transferring netgroup.byuser... ypxfr: Exiting: Map successfully transferred Transferring netgroup.byhost... ypxfr: Exiting: Map successfully transferred Transferring master.passwd.byuid... ypxfr: Exiting: Map successfully transferred Transferring passwd.byuid... ypxfr: Exiting: Map successfully transferred Transferring passwd.byname... ypxfr: Exiting: Map successfully transferred Transferring group.bygid... ypxfr: Exiting: Map successfully transferred Transferring group.byname... ypxfr: Exiting: Map successfully transferred Transferring services.byname... ypxfr: Exiting: Map successfully transferred Transferring rpc.bynumber... ypxfr: Exiting: Map successfully transferred Transferring rpc.byname... ypxfr: Exiting: Map successfully transferred Transferring protocols.byname... ypxfr: Exiting: Map successfully transferred Transferring master.passwd.byname... ypxfr: Exiting: Map successfully transferred Transferring networks.byname... ypxfr: Exiting: Map successfully transferred Transferring networks.byaddr... ypxfr: Exiting: Map successfully transferred Transferring netid.byname... ypxfr: Exiting: Map successfully transferred Transferring hosts.byaddr... ypxfr: Exiting: Map successfully transferred Transferring protocols.bynumber... ypxfr: Exiting: Map successfully transferred Transferring ypservers... ypxfr: Exiting: Map successfully transferred Transferring hosts.byname... ypxfr: Exiting: Map successfully transferred coltrane has been setup as an YP slave server without any errors. Don't forget to update map ypservers on ellington. You should now have a directory called /var/yp/test-domain. Copies of the NIS master server's maps should be in this directory. You will need to make sure that these stay updated. The following /etc/crontab entries on your slave servers should do the job: 20 * * * * root /usr/libexec/ypxfr passwd.byname 21 * * * * root /usr/libexec/ypxfr passwd.byuid These two lines force the slave to sync its maps with the maps on the master server. Although these entries are not mandatory, since the master server attempts to ensure any changes to its NIS maps are communicated to its slaves and because password information is vital to systems depending on the server, it is a good idea to force the updates. This is more important on busy networks where map updates might not always complete. Now, run the command /etc/netstart on the slave server as well, which again starts the NIS server. NIS Clients An NIS client establishes what is called a binding to a particular NIS server using the ypbind daemon. ypbind checks the system's default domain (as set by the domainname command), and begins broadcasting RPC requests on the local network. These requests specify the name of the domain for which ypbind is attempting to establish a binding. If a server that has been configured to serve the requested domain receives one of the broadcasts, it will respond to ypbind, which will record the server's address. If there are several servers available (a master and several slaves, for example), ypbind will use the address of the first one to respond. From that point on, the client system will direct all of its NIS requests to that server. ypbind will occasionally ping the server to make sure it is still up and running. If it fails to receive a reply to one of its pings within a reasonable amount of time, ypbind will mark the domain as unbound and begin broadcasting again in the hopes of locating another server. Setting Up a NIS Client NIS client configuration Setting up a FreeBSD machine to be a NIS client is fairly straightforward. Edit the file /etc/rc.conf and add the following lines in order to set the NIS domainname and start ypbind upon network startup: nisdomainname="test-domain" nis_client_enable="YES" To import all possible password entries from the NIS server, remove all user accounts from your /etc/master.passwd file and use vipw to add the following line to the end of the file: +::::::::: This line will afford anyone with a valid account in the NIS server's password maps an account. There are many ways to configure your NIS client by changing this line. See the netgroups section below for more information. For more detailed reading see O'Reilly's book on Managing NFS and NIS. You should keep at least one local account (i.e. not imported via NIS) in your /etc/master.passwd and this account should also be a member of the group wheel. If there is something wrong with NIS, this account can be used to log in remotely, become root, and fix things. To import all possible group entries from the NIS server, add this line to your /etc/group file: +:*:: After completing these steps, you should be able to run ypcat passwd and see the NIS server's passwd map. NIS Security In general, any remote user can issue an RPC to &man.ypserv.8; and retrieve the contents of your NIS maps, provided the remote user knows your domainname. To prevent such unauthorized transactions, &man.ypserv.8; supports a feature called securenets which can be used to restrict access to a given set of hosts. At startup, &man.ypserv.8; will attempt to load the securenets information from a file called /var/yp/securenets. This path varies depending on the path specified with the option. This file contains entries that consist of a network specification and a network mask separated by white space. Lines starting with # are considered to be comments. A sample securenets file might look like this: # allow connections from local host -- mandatory 127.0.0.1 255.255.255.255 # allow connections from any host # on the 192.168.128.0 network 192.168.128.0 255.255.255.0 # allow connections from any host # between 10.0.0.0 to 10.0.15.255 # this includes the machines in the testlab 10.0.0.0 255.255.240.0 If &man.ypserv.8; receives a request from an address that matches one of these rules, it will process the request normally. If the address fails to match a rule, the request will be ignored and a warning message will be logged. If the /var/yp/securenets file does not exist, ypserv will allow connections from any host. The ypserv program also has support for Wietse Venema's tcpwrapper package. This allows the administrator to use the tcpwrapper configuration files for access control instead of /var/yp/securenets. While both of these access control mechanisms provide some security, they, like the privileged port test, are vulnerable to IP spoofing attacks. All NIS-related traffic should be blocked at your firewall. Servers using /var/yp/securenets may fail to serve legitimate NIS clients with archaic TCP/IP implementations. Some of these implementations set all host bits to zero when doing broadcasts and/or fail to observe the subnet mask when calculating the broadcast address. While some of these problems can be fixed by changing the client configuration, other problems may force the retirement of the client systems in question or the abandonment of /var/yp/securenets. Using /var/yp/securenets on a server with such an archaic implementation of TCP/IP is a really bad idea and will lead to loss of NIS functionality for large parts of your network. tcpwrapper The use of the tcpwrapper package increases the latency of your NIS server. The additional delay may be long enough to cause timeouts in client programs, especially in busy networks or with slow NIS servers. If one or more of your client systems suffers from these symptoms, you should convert the client systems in question into NIS slave servers and force them to bind to themselves. Barring Some Users from Logging On In our lab, there is a machine basie that is supposed to be a faculty only workstation. We do not want to take this machine out of the NIS domain, yet the passwd file on the master NIS server contains accounts for both faculty and students. What can we do? There is a way to bar specific users from logging on to a machine, even if they are present in the NIS database. To do this, all you must do is add -username to the end of the /etc/master.passwd file on the client machine, where username is the username of the user you wish to bar from logging in. This should preferably be done using vipw, since vipw will sanity check your changes to /etc/master.passwd, as well as automatically rebuild the password database when you finish editing. For example, if we wanted to bar user bill from logging on to basie we would: basie&prompt.root; vipw [add -bill to the end, exit] vipw: rebuilding the database... vipw: done basie&prompt.root; cat /etc/master.passwd root:[password]:0:0::0:0:The super-user:/root:/bin/csh toor:[password]:0:0::0:0:The other super-user:/root:/bin/sh daemon:*:1:1::0:0:Owner of many system processes:/root:/sbin/nologin operator:*:2:5::0:0:System &:/:/sbin/nologin bin:*:3:7::0:0:Binaries Commands and Source,,,:/:/sbin/nologin tty:*:4:65533::0:0:Tty Sandbox:/:/sbin/nologin kmem:*:5:65533::0:0:KMem Sandbox:/:/sbin/nologin games:*:7:13::0:0:Games pseudo-user:/usr/games:/sbin/nologin news:*:8:8::0:0:News Subsystem:/:/sbin/nologin man:*:9:9::0:0:Mister Man Pages:/usr/share/man:/sbin/nologin bind:*:53:53::0:0:Bind Sandbox:/:/sbin/nologin uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/libexec/uucp/uucico xten:*:67:67::0:0:X-10 daemon:/usr/local/xten:/sbin/nologin pop:*:68:6::0:0:Post Office Owner:/nonexistent:/sbin/nologin nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/sbin/nologin +::::::::: -bill basie&prompt.root; Udo Erdelhoff Contributed by Using Netgroups netgroups The method shown in the previous section works reasonably well if you need special rules for a very small number of users and/or machines. On larger networks, you will forget to bar some users from logging onto sensitive machines, or you may even have to modify each machine separately, thus losing the main benefit of NIS: centralized administration. The NIS developers' solution for this problem is called netgroups. Their purpose and semantics can be compared to the normal groups used by &unix; file systems. The main differences are the lack of a numeric ID and the ability to define a netgroup by including both user accounts and other netgroups. Netgroups were developed to handle large, complex networks with hundreds of users and machines. On one hand, this is a Good Thing if you are forced to deal with such a situation. On the other hand, this complexity makes it almost impossible to explain netgroups with really simple examples. The example used in the remainder of this section demonstrates this problem. Let us assume that your successful introduction of NIS in your laboratory caught your superiors' interest. Your next job is to extend your NIS domain to cover some of the other machines on campus. The two tables contain the names of the new users and new machines as well as brief descriptions of them. User Name(s) Description alpha, beta Normal employees of the IT department charlie, delta The new apprentices of the IT department echo, foxtrott, golf, ... Ordinary employees able, baker, ... The current interns Machine Name(s) Description war, death, famine, pollution Your most important servers. Only the IT employees are allowed to log onto these machines. pride, greed, envy, wrath, lust, sloth Less important servers. All members of the IT department are allowed to login onto these machines. one, two, three, four, ... Ordinary workstations. Only the real employees are allowed to use these machines. trashcan A very old machine without any critical data. Even the intern is allowed to use this box. If you tried to implement these restrictions by separately blocking each user, you would have to add one -user line to each system's passwd for each user who is not allowed to login onto that system. If you forget just one entry, you could be in trouble. It may be feasible to do this correctly during the initial setup, however you will eventually forget to add the lines for new users during day-to-day operations. After all, Murphy was an optimist. Handling this situation with netgroups offers several advantages. Each user need not be handled separately; you assign a user to one or more netgroups and allow or forbid logins for all members of the netgroup. If you add a new machine, you will only have to define login restrictions for netgroups. If a new user is added, you will only have to add the user to one or more netgroups. Those changes are independent of each other: no more for each combination of user and machine do... If your NIS setup is planned carefully, you will only have to modify exactly one central configuration file to grant or deny access to machines. The first step is the initialization of the NIS map netgroup. FreeBSD's &man.ypinit.8; does not create this map by default, but its NIS implementation will support it once it has been created. To create an empty map, simply type ellington&prompt.root; vi /var/yp/netgroup and start adding content. For our example, we need at least four netgroups: IT employees, IT apprentices, normal employees and interns. IT_EMP (,alpha,test-domain) (,beta,test-domain) IT_APP (,charlie,test-domain) (,delta,test-domain) USERS (,echo,test-domain) (,foxtrott,test-domain) \ (,golf,test-domain) INTERNS (,able,test-domain) (,baker,test-domain) IT_EMP, IT_APP etc. are the names of the netgroups. Each bracketed group adds one or more user accounts to it. The three fields inside a group are: The name of the host(s) where the following items are valid. If you do not specify a hostname, the entry is valid on all hosts. If you do specify a hostname, you will enter a realm of darkness, horror and utter confusion. The name of the account that belongs to this netgroup. The NIS domain for the account. You can import accounts from other NIS domains into your netgroup if you are one of the unlucky fellows with more than one NIS domain. Each of these fields can contain wildcards. See &man.netgroup.5; for details. netgroups Netgroup names longer than 8 characters should not be used, especially if you have machines running other operating systems within your NIS domain. The names are case sensitive; using capital letters for your netgroup names is an easy way to distinguish between user, machine and netgroup names. Some NIS clients (other than FreeBSD) cannot handle netgroups with a large number of entries. For example, some older versions of &sunos; start to cause trouble if a netgroup contains more than 15 entries. You can circumvent this limit by creating several sub-netgroups with 15 users or less and a real netgroup that consists of the sub-netgroups: BIGGRP1 (,joe1,domain) (,joe2,domain) (,joe3,domain) [...] BIGGRP2 (,joe16,domain) (,joe17,domain) [...] BIGGRP3 (,joe31,domain) (,joe32,domain) BIGGROUP BIGGRP1 BIGGRP2 BIGGRP3 You can repeat this process if you need more than 225 users within a single netgroup. Activating and distributing your new NIS map is easy: ellington&prompt.root; cd /var/yp ellington&prompt.root; make This will generate the three NIS maps netgroup, netgroup.byhost and netgroup.byuser. Use &man.ypcat.1; to check if your new NIS maps are available: ellington&prompt.user; ypcat -k netgroup ellington&prompt.user; ypcat -k netgroup.byhost ellington&prompt.user; ypcat -k netgroup.byuser The output of the first command should resemble the contents of /var/yp/netgroup. The second command will not produce output if you have not specified host-specific netgroups. The third command can be used to get the list of netgroups for a user. The client setup is quite simple. To configure the server war, you only have to start &man.vipw.8; and replace the line +::::::::: with +@IT_EMP::::::::: Now, only the data for the users defined in the netgroup IT_EMP is imported into war's password database and only these users are allowed to login. Unfortunately, this limitation also applies to the ~ function of the shell and all routines converting between user names and numerical user IDs. In other words, cd ~user will not work, ls -l will show the numerical ID instead of the username and find . -user joe -print will fail with No such user. To fix this, you will have to import all user entries without allowing them to login onto your servers. This can be achieved by adding another line to /etc/master.passwd. This line should contain: +:::::::::/sbin/nologin, meaning Import all entries but replace the shell with /sbin/nologin in the imported entries. You can replace any field in the passwd entry by placing a default value in your /etc/master.passwd. Make sure that the line +:::::::::/sbin/nologin is placed after +@IT_EMP:::::::::. Otherwise, all user accounts imported from NIS will have /sbin/nologin as their login shell. After this change, you will only have to change one NIS map if a new employee joins the IT department. You could use a similar approach for the less important servers by replacing the old +::::::::: in their local version of /etc/master.passwd with something like this: +@IT_EMP::::::::: +@IT_APP::::::::: +:::::::::/sbin/nologin The corresponding lines for the normal workstations could be: +@IT_EMP::::::::: +@USERS::::::::: +:::::::::/sbin/nologin And everything would be fine until there is a policy change a few weeks later: The IT department starts hiring interns. The IT interns are allowed to use the normal workstations and the less important servers; and the IT apprentices are allowed to login onto the main servers. You add a new netgroup IT_INTERN, add the new IT interns to this netgroup and start to change the configuration on each and every machine... As the old saying goes: Errors in centralized planning lead to global mess. NIS' ability to create netgroups from other netgroups can be used to prevent situations like these. One possibility is the creation of role-based netgroups. For example, you could create a netgroup called BIGSRV to define the login restrictions for the important servers, another netgroup called SMALLSRV for the less important servers and a third netgroup called USERBOX for the normal workstations. Each of these netgroups contains the netgroups that are allowed to login onto these machines. The new entries for your NIS map netgroup should look like this: BIGSRV IT_EMP IT_APP SMALLSRV IT_EMP IT_APP ITINTERN USERBOX IT_EMP ITINTERN USERS This method of defining login restrictions works reasonably well if you can define groups of machines with identical restrictions. Unfortunately, this is the exception and not the rule. Most of the time, you will need the ability to define login restrictions on a per-machine basis. Machine-specific netgroup definitions are the other possibility to deal with the policy change outlined above. In this scenario, the /etc/master.passwd of each box contains two lines starting with +. The first of them adds a netgroup with the accounts allowed to login onto this machine, the second one adds all other accounts with /sbin/nologin as shell. It is a good idea to use the ALL-CAPS version of the machine name as the name of the netgroup. In other words, the lines should look like this: +@BOXNAME::::::::: +:::::::::/sbin/nologin Once you have completed this task for all your machines, you will not have to modify the local versions of /etc/master.passwd ever again. All further changes can be handled by modifying the NIS map. Here is an example of a possible netgroup map for this scenario with some additional goodies: # Define groups of users first IT_EMP (,alpha,test-domain) (,beta,test-domain) IT_APP (,charlie,test-domain) (,delta,test-domain) DEPT1 (,echo,test-domain) (,foxtrott,test-domain) DEPT2 (,golf,test-domain) (,hotel,test-domain) DEPT3 (,india,test-domain) (,juliet,test-domain) ITINTERN (,kilo,test-domain) (,lima,test-domain) D_INTERNS (,able,test-domain) (,baker,test-domain) # # Now, define some groups based on roles USERS DEPT1 DEPT2 DEPT3 BIGSRV IT_EMP IT_APP SMALLSRV IT_EMP IT_APP ITINTERN USERBOX IT_EMP ITINTERN USERS # # And a groups for a special tasks # Allow echo and golf to access our anti-virus-machine SECURITY IT_EMP (,echo,test-domain) (,golf,test-domain) # # machine-based netgroups # Our main servers WAR BIGSRV FAMINE BIGSRV # User india needs access to this server POLLUTION BIGSRV (,india,test-domain) # # This one is really important and needs more access restrictions DEATH IT_EMP # # The anti-virus-machine mentioned above ONE SECURITY # # Restrict a machine to a single user TWO (,hotel,test-domain) # [...more groups to follow] If you are using some kind of database to manage your user accounts, you should be able to create the first part of the map with your database's report tools. This way, new users will automatically have access to the boxes. One last word of caution: It may not always be advisable to use machine-based netgroups. If you are deploying a couple of dozen or even hundreds of identical machines for student labs, you should use role-based netgroups instead of machine-based netgroups to keep the size of the NIS map within reasonable limits. Important Things to Remember There are still a couple of things that you will need to do differently now that you are in an NIS environment. Every time you wish to add a user to the lab, you must add it to the master NIS server only, and you must remember to rebuild the NIS maps. If you forget to do this, the new user will not be able to login anywhere except on the NIS master. For example, if we needed to add a new user jsmith to the lab, we would: &prompt.root; pw useradd jsmith &prompt.root; cd /var/yp &prompt.root; make test-domain You could also run adduser jsmith instead of pw useradd jsmith. Keep the administration accounts out of the NIS maps. You do not want to be propagating administrative accounts and passwords to machines that will have users that should not have access to those accounts. Keep the NIS master and slave secure, and minimize their downtime. If somebody either hacks or simply turns off these machines, they have effectively rendered many people without the ability to login to the lab. This is the chief weakness of any centralized administration system. If you do not protect your NIS servers, you will have a lot of angry users! NIS v1 Compatibility FreeBSD's ypserv has some support for serving NIS v1 clients. FreeBSD's NIS implementation only uses the NIS v2 protocol, however other implementations include support for the v1 protocol for backwards compatibility with older systems. The ypbind daemons supplied with these systems will try to establish a binding to an NIS v1 server even though they may never actually need it (and they may persist in broadcasting in search of one even after they receive a response from a v2 server). Note that while support for normal client calls is provided, this version of ypserv does not handle v1 map transfer requests; consequently, it cannot be used as a master or slave in conjunction with older NIS servers that only support the v1 protocol. Fortunately, there probably are not any such servers still in use today. NIS Servers That Are Also NIS Clients Care must be taken when running ypserv in a multi-server domain where the server machines are also NIS clients. It is generally a good idea to force the servers to bind to themselves rather than allowing them to broadcast bind requests and possibly become bound to each other. Strange failure modes can result if one server goes down and others are dependent upon it. Eventually all the clients will time out and attempt to bind to other servers, but the delay involved can be considerable and the failure mode is still present since the servers might bind to each other all over again. You can force a host to bind to a particular server by running ypbind with the flag. If you do not want to do this manually each time you reboot your NIS server, you can add the following lines to your /etc/rc.conf: nis_client_enable="YES" # run client stuff as well nis_client_flags="-S NIS domain,server" See &man.ypbind.8; for further information. Password Formats NIS password formats One of the most common issues that people run into when trying to implement NIS is password format compatibility. If your NIS server is using DES encrypted passwords, it will only support clients that are also using DES. For example, if you have &solaris; NIS clients in your network, then you will almost certainly need to use DES encrypted passwords. To check which format your servers and clients are using, look at /etc/login.conf. If the host is configured to use DES encrypted passwords, then the default class will contain an entry like this: default:\ :passwd_format=des:\ :copyright=/etc/COPYRIGHT:\ [Further entries elided] Other possible values for the passwd_format capability include blf and md5 (for Blowfish and MD5 encrypted passwords, respectively). If you have made changes to /etc/login.conf, you will also need to rebuild the login capability database, which is achieved by running the following command as root: &prompt.root; cap_mkdb /etc/login.conf The format of passwords already in /etc/master.passwd will not be updated until a user changes his password for the first time after the login capability database is rebuilt. Next, in order to ensure that passwords are encrypted with the format that you have chosen, you should also check that the crypt_default in /etc/auth.conf gives precedence to your chosen password format. To do this, place the format that you have chosen first in the list. For example, when using DES encrypted passwords, the entry would be: crypt_default = des blf md5 Having followed the above steps on each of the &os; based NIS servers and clients, you can be sure that they all agree on which password format is used within your network. If you have trouble authenticating on an NIS client, this is a pretty good place to start looking for possible problems. Remember: if you want to deploy an NIS server for a heterogenous network, you will probably have to use DES on all systems because it is the lowest common standard. Greg Sutter Written by Automatic Network Configuration (DHCP) What Is DHCP? Dynamic Host Configuration Protocol DHCP Internet Software Consortium (ISC) DHCP, the Dynamic Host Configuration Protocol, describes the means by which a system can connect to a network and obtain the necessary information for communication upon that network. FreeBSD uses the ISC (Internet Software Consortium) DHCP implementation, so all implementation-specific information here is for use with the ISC distribution. What This Section Covers This section describes both the client-side and server-side components of the ISC DHCP system. The client-side program, dhclient, comes integrated within FreeBSD, and the server-side portion is available from the net/isc-dhcp3-server port. The &man.dhclient.8;, &man.dhcp-options.5;, and &man.dhclient.conf.5; manual pages, in addition to the references below, are useful resources. How It Works UDP When dhclient, the DHCP client, is executed on the client machine, it begins broadcasting requests for configuration information. By default, these requests are on UDP port 68. The server replies on UDP 67, giving the client an IP address and other relevant network information such as netmask, router, and DNS servers. All of this information comes in the form of a DHCP lease and is only valid for a certain time (configured by the DHCP server maintainer). In this manner, stale IP addresses for clients no longer connected to the network can be automatically reclaimed. DHCP clients can obtain a great deal of information from the server. An exhaustive list may be found in &man.dhcp-options.5;. FreeBSD Integration FreeBSD fully integrates the ISC DHCP client, dhclient. DHCP client support is provided within both the installer and the base system, obviating the need for detailed knowledge of network configurations on any network that runs a DHCP server. dhclient has been included in all FreeBSD distributions since 3.2. sysinstall DHCP is supported by sysinstall. When configuring a network interface within sysinstall, the first question asked is: Do you want to try DHCP configuration of this interface?. Answering affirmatively will execute dhclient, and if successful, will fill in the network configuration information automatically. There are two things you must do to have your system use DHCP upon startup: DHCP requirements Make sure that the bpf device is compiled into your kernel. To do this, add device bpf (pseudo-device bpf under &os; 4.X) to your kernel configuration file, and rebuild the kernel. For more information about building kernels, see . The bpf device is already part of the GENERIC kernel that is supplied with FreeBSD, so if you do not have a custom kernel, you should not need to create one in order to get DHCP working. For those who are particularly security conscious, you should be warned that bpf is also the device that allows packet sniffers to work correctly (although they still have to be run as root). bpf is required to use DHCP, but if you are very sensitive about security, you probably should not add bpf to your kernel in the expectation that at some point in the future you will be using DHCP. Edit your /etc/rc.conf to include the following: ifconfig_fxp0="DHCP" Be sure to replace fxp0 with the designation for the interface that you wish to dynamically configure, as described in . If you are using a different location for dhclient, or if you wish to pass additional flags to dhclient, also include the following (editing as necessary): dhcp_program="/sbin/dhclient" dhcp_flags="" DHCP server The DHCP server, dhcpd, is included as part of the net/isc-dhcp3-server port in the ports collection. This port contains the ISC DHCP server and documentation. Files DHCP configuration files /etc/dhclient.conf dhclient requires a configuration file, /etc/dhclient.conf. Typically the file contains only comments, the defaults being reasonably sane. This configuration file is described by the &man.dhclient.conf.5; manual page. /sbin/dhclient dhclient is statically linked and resides in /sbin. The &man.dhclient.8; manual page gives more information about dhclient. /sbin/dhclient-script dhclient-script is the FreeBSD-specific DHCP client configuration script. It is described in &man.dhclient-script.8;, but should not need any user modification to function properly. /var/db/dhclient.leases The DHCP client keeps a database of valid leases in this file, which is written as a log. &man.dhclient.leases.5; gives a slightly longer description. Further Reading The DHCP protocol is fully described in RFC 2131. An informational resource has also been set up at . Installing and Configuring a DHCP Server What This Section Covers This section provides information on how to configure a FreeBSD system to act as a DHCP server using the ISC (Internet Software Consortium) implementation of the DHCP suite. The server portion of the suite is not provided as part of FreeBSD, and so you will need to install the net/isc-dhcp3-server port to provide this service. See for more information on using the ports collection. DHCP Server Installation DHCP installation In order to configure your FreeBSD system as a DHCP server, you will need to ensure that the &man.bpf.4; device is compiled into your kernel. To do this, add device bpf (pseudo-device bpf under &os; 4.X) to your kernel configuration file, and rebuild the kernel. For more information about building kernels, see . The bpf device is already part of the GENERIC kernel that is supplied with FreeBSD, so you do not need to create a custom kernel in order to get DHCP working. Those who are particularly security conscious should note that bpf is also the device that allows packet sniffers to work correctly (although such programs still need privileged access). bpf is required to use DHCP, but if you are very sensitive about security, you probably should not include bpf in your kernel purely because you expect to use DHCP at some point in the future. The next thing that you will need to do is edit the sample dhcpd.conf which was installed by the net/isc-dhcp3-server port. By default, this will be /usr/local/etc/dhcpd.conf.sample, and you should copy this to /usr/local/etc/dhcpd.conf before proceeding to make changes. Configuring the DHCP Server DHCP dhcpd.conf dhcpd.conf is comprised of declarations regarding subnets and hosts, and is perhaps most easily explained using an example : option domain-name "example.com"; option domain-name-servers 192.168.4.100; option subnet-mask 255.255.255.0; default-lease-time 3600; max-lease-time 86400; ddns-update-style none; subnet 192.168.4.0 netmask 255.255.255.0 { range 192.168.4.129 192.168.4.254; option routers 192.168.4.1; } host mailhost { hardware ethernet 02:03:04:05:06:07; fixed-address mailhost.example.com; } This option specifies the domain that will be provided to clients as the default search domain. See &man.resolv.conf.5; for more information on what this means. This option specifies a comma separated list of DNS servers that the client should use. The netmask that will be provided to clients. A client may request a specific length of time that a lease will be valid. Otherwise the server will assign a lease with this expiry value (in seconds). This is the maximum length of time that the server will lease for. Should a client request a longer lease, a lease will be issued, although it will only be valid for max-lease-time seconds. This option specifies whether the DHCP server should attempt to update DNS when a lease is accepted or released. In the ISC implementation, this option is required. This denotes which IP addresses should be used in the pool reserved for allocating to clients. IP addresses between, and including, the ones stated are handed out to clients. Declares the default gateway that will be provided to clients. The hardware MAC address of a host (so that the DHCP server can recognize a host when it makes a request). Specifies that the host should always be given the same IP address. Note that using a hostname is correct here, since the DHCP server will resolve the hostname itself before returning the lease information. Once you have finished writing your dhcpd.conf, you can proceed to start the server by issuing the following command: &prompt.root; /usr/local/etc/rc.d/isc-dhcpd.sh start Should you need to make changes to the configuration of your server in the future, it is important to note that sending a SIGHUP signal to dhcpd does not result in the configuration being reloaded, as it does with most daemons. You will need to send a SIGTERM signal to stop the process, and then restart it using the command above. Files DHCP configuration files /usr/local/sbin/dhcpd dhcpd is statically linked and resides in /usr/local/sbin. The &man.dhcpd.8; manual page installed with the port gives more information about dhcpd. /usr/local/etc/dhcpd.conf dhcpd requires a configuration file, /usr/local/etc/dhcpd.conf before it will start providing service to clients. This file needs to contain all the information that should be provided to clients that are being serviced, along with information regarding the operation of the server. This configuration file is described by the &man.dhcpd.conf.5; manual page installed by the port. /var/db/dhcpd.leases The DHCP server keeps a database of leases it has issued in this file, which is written as a log. The manual page &man.dhcpd.leases.5;, installed by the port gives a slightly longer description. /usr/local/sbin/dhcrelay dhcrelay is used in advanced environments where one DHCP server forwards a request from a client to another DHCP server on a separate network. If you require this functionality, then install the net/isc-dhcp3-relay port. The &man.dhcrelay.8; manual page provided with the port contains more detail. Chern Lee Contributed by Domain Name System (DNS) Overview BIND FreeBSD utilizes, by default, a version of BIND (Berkeley Internet Name Domain), which is the most common implementation of the DNS protocol. DNS is the protocol through which names are mapped to IP addresses, and vice versa. For example, a query for www.FreeBSD.org will receive a reply with the IP address of The FreeBSD Project's web server, whereas, a query for ftp.FreeBSD.org will return the IP address of the corresponding FTP machine. Likewise, the opposite can happen. A query for an IP address can resolve its hostname. It is not necessary to run a name server to perform DNS lookups on a system. DNS DNS is coordinated across the Internet through a somewhat complex system of authoritative root name servers, and other smaller-scale name servers who host and cache individual domain information. This document refers to BIND 8.x, as it is the stable version used in FreeBSD. BIND 9.x in FreeBSD can be installed through the net/bind9 port. RFC1034 and RFC1035 dictate the DNS protocol. Currently, BIND is maintained by the Internet Software Consortium . Terminology To understand this document, some terms related to DNS must be understood. resolver reverse DNS root zone Term Definition Forward DNS Mapping of hostnames to IP addresses Origin Refers to the domain covered in a particular zone file named, BIND, name server Common names for the BIND name server package within FreeBSD Resolver A system process through which a machine queries a name server for zone information Reverse DNS The opposite of forward DNS; mapping of IP addresses to hostnames Root zone The beginning of the Internet zone hierarchy. All zones fall under the root zone, similar to how all files in a file system fall under the root directory. Zone An individual domain, subdomain, or portion of the DNS administered by the same authority zones examples Examples of zones: . is the root zone org. is a zone under the root zone example.org is a zone under the org. zone foo.example.org. is a subdomain, a zone under the example.org. zone 1.2.3.in-addr.arpa is a zone referencing all IP addresses which fall under the 3.2.1.* IP space. As one can see, the more specific part of a hostname appears to its left. For example, example.org. is more specific than org., as org. is more specific than the root zone. The layout of each part of a hostname is much like a filesystem: the /dev directory falls within the root, and so on. Reasons to Run a Name Server Name servers usually come in two forms: an authoritative name server, and a caching name server. An authoritative name server is needed when: one wants to serve DNS information to the world, replying authoritatively to queries. a domain, such as example.org, is registered and IP addresses need to be assigned to hostnames under it. an IP address block requires reverse DNS entries (IP to hostname). a backup name server, called a slave, must reply to queries when the primary is down or inaccessible. A caching name server is needed when: a local DNS server may cache and respond more quickly than querying an outside name server. a reduction in overall network traffic is desired (DNS traffic has been measured to account for 5% or more of total Internet traffic). When one queries for www.FreeBSD.org, the resolver usually queries the uplink ISP's name server, and retrieves the reply. With a local, caching DNS server, the query only has to be made once to the outside world by the caching DNS server. Every additional query will not have to look to the outside of the local network, since the information is cached locally. How It Works In FreeBSD, the BIND daemon is called named for obvious reasons. File Description named the BIND daemon ndc name daemon control program /etc/namedb directory where BIND zone information resides /etc/namedb/named.conf daemon configuration file Zone files are usually contained within the /etc/namedb directory, and contain the DNS zone information served by the name server. Starting BIND BIND starting Since BIND is installed by default, configuring it all is relatively simple. To ensure the named daemon is started at boot, put the following line in /etc/rc.conf: named_enable="YES" To start the daemon manually (after configuring it): &prompt.root; ndc start Configuration Files BIND configuration files Using <command>make-localhost</command> Be sure to: &prompt.root; cd /etc/namedb &prompt.root; sh make-localhost to properly create the local reverse DNS zone file in /etc/namedb/localhost.rev. <filename>/etc/namedb/named.conf</filename> // $FreeBSD$ // // Refer to the named(8) manual page for details. If you are ever going // to setup a primary server, make sure you've understood the hairy // details of how DNS is working. Even with simple mistakes, you can // break connectivity for affected parties, or cause huge amount of // useless Internet traffic. options { directory "/etc/namedb"; // In addition to the "forwarders" clause, you can force your name // server to never initiate queries of its own, but always ask its // forwarders only, by enabling the following line: // // forward only; // If you've got a DNS server around at your upstream provider, enter // its IP address here, and enable the line below. This will make you // benefit from its cache, thus reduce overall DNS traffic in the Internet. /* forwarders { 127.0.0.1; }; */ Just as the comment says, to benefit from an uplink's cache, forwarders can be enabled here. Under normal circumstances, a name server will recursively query the Internet looking at certain name servers until it finds the answer it is looking for. Having this enabled will have it query the uplink's name server (or name server provided) first, taking advantage of its cache. If the uplink name server in question is a heavily trafficked, fast name server, enabling this may be worthwhile. 127.0.0.1 will not work here. Change this IP address to a name server at your uplink. /* * If there is a firewall between you and name servers you want * to talk to, you might need to uncomment the query-source * directive below. Previous versions of BIND always asked * questions using port 53, but BIND 8.1 uses an unprivileged * port by default. */ // query-source address * port 53; /* * If running in a sandbox, you may have to specify a different * location for the dumpfile. */ // dump-file "s/named_dump.db"; }; // Note: the following will be supported in a future release. /* host { any; } { topology { 127.0.0.0/8; }; }; */ // Setting up secondaries is way easier and the rough picture for this // is explained below. // // If you enable a local name server, don't forget to enter 127.0.0.1 // into your /etc/resolv.conf so this server will be queried first. // Also, make sure to enable it in /etc/rc.conf. zone "." { type hint; file "named.root"; }; zone "0.0.127.IN-ADDR.ARPA" { type master; file "localhost.rev"; }; zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.INT" { type master; file "localhost.rev"; }; // NB: Do not use the IP addresses below, they are faked, and only // serve demonstration/documentation purposes! // // Example secondary config entries. It can be convenient to become // a secondary at least for the zone where your own domain is in. Ask // your network administrator for the IP address of the responsible // primary. // // Never forget to include the reverse lookup (IN-ADDR.ARPA) zone! // (This is the first bytes of the respective IP address, in reverse // order, with ".IN-ADDR.ARPA" appended.) // // Before starting to setup a primary zone, better make sure you fully // understand how DNS and BIND works, however. There are sometimes // unobvious pitfalls. Setting up a secondary is comparably simpler. // // NB: Don't blindly enable the examples below. :-) Use actual names // and addresses instead. // // NOTE!!! FreeBSD runs BIND in a sandbox (see named_flags in rc.conf). // The directory containing the secondary zones must be write accessible // to BIND. The following sequence is suggested: // // mkdir /etc/namedb/s // chown bind:bind /etc/namedb/s // chmod 750 /etc/namedb/s For more information on running BIND in a sandbox, see Running named in a sandbox. /* zone "example.com" { type slave; file "s/example.com.bak"; masters { 192.168.1.1; }; }; zone "0.168.192.in-addr.arpa" { type slave; file "s/0.168.192.in-addr.arpa.bak"; masters { 192.168.1.1; }; }; */ In named.conf, these are examples of slave entries for a forward and reverse zone. For each new zone served, a new zone entry must be added to named.conf. For example, the simplest zone entry for example.org can look like: zone "example.org" { type master; file "example.org"; }; The zone is a master, as indicated by the statement, holding its zone information in /etc/namedb/example.org indicated by the statement. zone "example.org" { type slave; file "example.org"; }; In the slave case, the zone information is transferred from the master name server for the particular zone, and saved in the file specified. If and when the master server dies or is unreachable, the slave name server will have the transferred zone information and will be able to serve it. Zone Files An example master zone file for example.org (existing within /etc/namedb/example.org) is as follows: $TTL 3600 example.org. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh 3600 ; Retry 604800 ; Expire 86400 ) ; Minimum TTL ; DNS Servers @ IN NS ns1.example.org. @ IN NS ns2.example.org. ; Machine Names localhost IN A 127.0.0.1 ns1 IN A 3.2.1.2 ns2 IN A 3.2.1.3 mail IN A 3.2.1.10 @ IN A 3.2.1.30 ; Aliases www IN CNAME @ ; MX Record @ IN MX 10 mail.example.org. Note that every hostname ending in a . is an exact hostname, whereas everything without a trailing . is referenced to the origin. For example, www is translated into www.origin. In our fictitious zone file, our origin is example.org., so www would translate to www.example.org. The format of a zone file follows: recordname IN recordtype value DNS records The most commonly used DNS records: SOA start of zone authority NS an authoritative name server A a host address CNAME the canonical name for an alias MX mail exchanger PTR a domain name pointer (used in reverse DNS) example.org. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh after 3 hours 3600 ; Retry after 1 hour 604800 ; Expire after 1 week 86400 ) ; Minimum TTL of 1 day example.org. the domain name, also the origin for this zone file. ns1.example.org. the primary/authoritative name server for this zone. admin.example.org. the responsible person for this zone, email address with @ replaced. (admin@example.org becomes admin.example.org) 5 the serial number of the file. This must be incremented each time the zone file is modified. Nowadays, many admins prefer a yyyymmddrr format for the serial number. 2001041002 would mean last modified 04/10/2001, the latter 02 being the second time the zone file has been modified this day. The serial number is important as it alerts slave name servers for a zone when it is updated. @ IN NS ns1.example.org. This is an NS entry. Every name server that is going to reply authoritatively for the zone must have one of these entries. The @ as seen here could have been example.org. The @ translates to the origin. localhost IN A 127.0.0.1 ns1 IN A 3.2.1.2 ns2 IN A 3.2.1.3 mail IN A 3.2.1.10 @ IN A 3.2.1.30 The A record indicates machine names. As seen above, ns1.example.org would resolve to 3.2.1.2. Again, the origin symbol, @, is used here, thus meaning example.org would resolve to 3.2.1.30. www IN CNAME @ The canonical name record is usually used for giving aliases to a machine. In the example, www is aliased to the machine addressed to the origin, or example.org (3.2.1.30). CNAMEs can be used to provide alias hostnames, or round robin one hostname among multiple machines. MX record @ IN MX 10 mail.example.org. The MX record indicates which mail servers are responsible for handling incoming mail for the zone. mail.example.org is the hostname of the mail server, and 10 being the priority of that mail server. One can have several mail servers, with priorities of 3, 2, 1. A mail server attempting to deliver to example.org would first try the highest priority MX, then the second highest, etc, until the mail can be properly delivered. For in-addr.arpa zone files (reverse DNS), the same format is used, except with PTR entries instead of A or CNAME. $TTL 3600 1.2.3.in-addr.arpa. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh 3600 ; Retry 604800 ; Expire 3600 ) ; Minimum @ IN NS ns1.example.org. @ IN NS ns2.example.org. 2 IN PTR ns1.example.org. 3 IN PTR ns2.example.org. 10 IN PTR mail.example.org. 30 IN PTR example.org. This file gives the proper IP address to hostname mappings of our above fictitious domain. Caching Name Server BIND caching name server A caching name server is a name server that is not authoritative for any zones. It simply asks queries of its own, and remembers them for later use. To set one up, just configure the name server as usual, omitting any inclusions of zones. Running <application>named</application> in a Sandbox BIND running in a sandbox chroot For added security you may want to run &man.named.8; as an unprivileged user, and configure it to &man.chroot.8; into a sandbox directory. This makes everything outside of the sandbox inaccessible to the named daemon. Should named be compromised, this will help to reduce the damage that can be caused. By default, FreeBSD has a user and a group called bind, intended for this use. Various people would recommend that instead of configuring named to chroot, you should run named inside a &man.jail.8;. This section does not attempt to cover this situation. Since named will not be able to access anything outside of the sandbox (such as shared libraries, log sockets, and so on), there are a number of steps that need to be followed in order to allow named to function correctly. In the following checklist, it is assumed that the path to the sandbox is /etc/namedb and that you have made no prior modifications to the contents of this directory. Perform the following steps as root: Create all directories that named expects to see: &prompt.root; cd /etc/namedb &prompt.root; mkdir -p bin dev etc var/tmp var/run master slave &prompt.root; chown bind:bind slave var/* named only needs write access to these directories, so that is all we give it. Rearrange and create basic zone and configuration files: &prompt.root; cp /etc/localtime etc &prompt.root; mv named.conf etc && ln -sf etc/named.conf &prompt.root; mv named.root master &prompt.root; sh make-localhost && mv localhost.rev localhost-v6.rev master &prompt.root; cat > master/named.localhost $ORIGIN localhost. $TTL 6h @ IN SOA localhost. postmaster.localhost. ( 1 ; serial 3600 ; refresh 1800 ; retry 604800 ; expiration 3600 ) ; minimum IN NS localhost. IN A 127.0.0.1 ^D This allows named to log the correct time to &man.syslogd.8;. syslog logs DNS If you are running a version of &os; prior to 4.9-RELEASE, build a statically linked copy of named-xfer, and copy it into the sandbox: &prompt.root; cd /usr/src/lib/libisc &prompt.root; make cleandir && make cleandir && make depend && make all &prompt.root; cd /usr/src/lib/libbind &prompt.root; make cleandir && make cleandir && make depend && make all &prompt.root; cd /usr/src/libexec/named-xfer &prompt.root; make cleandir && make cleandir && make depend && make NOSHARED=yes all &prompt.root; cp named-xfer /etc/namedb/bin && chmod 555 /etc/namedb/bin/named-xfer After your statically linked named-xfer is installed some cleaning up is required, to avoid leaving stale copies of libraries or programs in your source tree: &prompt.root; cd /usr/src/lib/libisc &prompt.root; make cleandir &prompt.root; cd /usr/src/lib/libbind &prompt.root; make cleandir &prompt.root; cd /usr/src/libexec/named-xfer &prompt.root; make cleandir This step has been reported to fail occasionally. If this happens to you, then issue the command: &prompt.root; cd /usr/src && make cleandir && make cleandir and delete your /usr/obj tree: &prompt.root; rm -fr /usr/obj && mkdir /usr/obj This will clean out any cruft from your source tree, and retrying the steps above should then work. If you are running &os; version 4.9-RELEASE or later, then the copy of named-xfer in /usr/libexec is statically linked by default, and you can simply use &man.cp.1; to copy it into your sandbox. Make a dev/null that named can see and write to: &prompt.root; cd /etc/namedb/dev && mknod null c 2 2 &prompt.root; chmod 666 null Symlink /var/run/ndc to /etc/namedb/var/run/ndc: &prompt.root; ln -sf /etc/namedb/var/run/ndc /var/run/ndc This simply avoids having to specify the option to &man.ndc.8; every time you run it. Since the contents of /var/run are deleted on boot, if this is something that you find useful you may wish to add this command to root's crontab, making use of the option. See &man.crontab.5; for more information regarding this. syslog logs named Configure &man.syslogd.8; to create an extra log socket that named can write to. To do this, add -l /etc/namedb/dev/log to the syslogd_flags variable in /etc/rc.conf. chroot Arrange to have named start and chroot itself to the sandbox by adding the following to /etc/rc.conf: named_enable="YES" named_flags="-u bind -g bind -t /etc/namedb /etc/named.conf" Note that the configuration file /etc/named.conf is denoted by a full pathname relative to the sandbox, i.e. in the line above, the file referred to is actually /etc/namedb/etc/named.conf. The next step is to edit /etc/namedb/etc/named.conf so that named knows which zones to load and where to find them on the disk. There follows a commented example (anything not specifically commented here is no different from the setup for a DNS server not running in a sandbox): options { directory "/"; named-xfer "/bin/named-xfer"; version ""; // Don't reveal BIND version query-source address * port 53; }; // ndc control socket controls { unix "/var/run/ndc" perm 0600 owner 0 group 0; }; // Zones follow: zone "localhost" IN { type master; file "master/named.localhost"; allow-transfer { localhost; }; notify no; }; zone "0.0.127.in-addr.arpa" IN { type master; file "master/localhost.rev"; allow-transfer { localhost; }; notify no; }; zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.int" { type master; file "master/localhost-v6.rev"; allow-transfer { localhost; }; notify no; }; zone "." IN { type hint; file "master/named.root"; }; zone "private.example.net" in { type master; file "master/private.example.net.db"; allow-transfer { 192.168.10.0/24; }; }; zone "10.168.192.in-addr.arpa" in { type slave; masters { 192.168.10.2; }; file "slave/192.168.10.db"; }; The directory statement is specified as /, since all files that named needs are within this directory (recall that this is equivalent to a normal user's /etc/namedb). Specifies the full path to the named-xfer binary (from named's frame of reference). This is necessary since named is compiled to look for named-xfer in /usr/libexec by default. Specifies the filename (relative to the directory statement above) where named can find the zone file for this zone. Specifies the filename (relative to the directory statement above) where named should write a copy of the zone file for this zone after successfully transferring it from the master server. This is why we needed to change the ownership of the directory slave to bind in the setup stages above. After completing the steps above, either reboot your server or restart &man.syslogd.8; and start &man.named.8;, making sure to use the new options specified in syslogd_flags and named_flags. You should now be running a sandboxed copy of named! Security Although BIND is the most common implementation of DNS, there is always the issue of security. Possible and exploitable security holes are sometimes found. It is a good idea to read CERT's security advisories and to subscribe to the &a.security-notifications; to stay up to date with the current Internet and FreeBSD security issues. If a problem arises, keeping sources up to date and having a fresh build of named would not hurt. Further Reading BIND/named manual pages: &man.ndc.8; &man.named.8; &man.named.conf.5; Official ISC BIND Page BIND FAQ O'Reilly DNS and BIND 4th Edition RFC1034 - Domain Names - Concepts and Facilities RFC1035 - Domain Names - Implementation and Specification Tom Rhodes Written by <acronym>BIND</acronym>9 and &os; bind9 setting up The release of &os; 5.3 brought the BIND9 DNS server software into the distribution. New security features, a new file system layout and automated &man.chroot.8; configuration came with the import. This section has been written in two parts, the first will discuss new features and their configuration; the latter will cover upgrades to aid in move to &os; 5.3. From this moment on, the server will be referred to simply as &man.named.8; in place of BIND. This section skips over the terminology described in the previous section as well as some of the theoretical discussions; thus, it is recommended that the previous section be consulted before reading any further here. Configuration files for named currently reside in - /var/named/etc/namedb/ and + /var/named/etc/namedb/ and will need modification before use. This is where most of the configuration will be performed. Configuration of a Master Zone To configure a master zone visit - /var/named/etc/namedb/ + /var/named/etc/namedb/ and run the following command: &prompt.root; sh make-localhost If all went well a new file should exist in the - master directory. The + master directory. The filenames should be localhost.rev for the local domain name and localhost-v6.rev for IPv6 configurations. As the default configuration file, configuration for its use will already be present in the named.conf file. Configuration of a Slave Zone Configuration for extra domains or sub domains may be done properly by setting them as a slave zone. In most cases, the master/localhost.rev could just be - copied over into the slave + copied over into the slave directory and modified. Once completed, the files need to be properly added in named.conf such as in the following configuration for example.com: zone "example.com" { type slave; file "slave/example.com"; masters { 10.0.0.1; }; }; zone "0.168.192.in-addr.arpa" { type slave; file "slave/0.168.192.in-addr.arpa"; masters { 10.0.0.1; }; }; Note well that in this example, the master IP address is the primary domain server from which the zones are transferred; it does not necessary serve as DNS server itself. System Initialization Configuration In order for the named daemon to start when the system is booted, the following option must be present in the rc.conf file: named_enable="YES" While other options exist, this is the bare minimal requirement. Consult the &man.rc.conf.5; manual page for a list of the other options. If nothing is entered in the rc.conf file then named may be started on the command line by invoking: &prompt.root; /etc/rc.d/named start <acronym>BIND</acronym>9 Security While &os automatically drops named into a &man.chroot.8; environment; there are several other security mechanisms in place which could help to lure off possible DNS service attacks. Query Access Control Lists A query access control list can be used to restrict queries against the zones. The configuration works by defining the network inside of the acl token and then listing IP addresses in the zone configuration. To permit domains to query the example host, just define it like this: acl "example.com" { 192.168.0.0/24; }; zone "example.com" { type slave; file "slave/example.com"; masters { 10.0.0.1; }; allow-query { example.com; }; }; zone "0.168.192.in-addr.arpa" { type slave; file "slave/0.168.192.in-addr.arpa"; masters { 10.0.0.1; }; allow-query { example.com; }; }; Restrict Version Permitting version lookups on the DNS server could be opening the doors for an attacker. A malicious user may use this information to hunt up known exploits or bugs to utilize against the host. A false version string can be placed the options section of named.conf: options { directory "/etc/namedb"; pid-file "/var/run/named/pid"; dump-file "/var/dump/named_dump.db"; statistics-file "/var/stats/named.stats"; version "None of your business"; Murray Stokely Contributed by Apache HTTP Server web server setting up Apache Overview &os; is used to run some of the busiest web sites in the world. The majority of web servers on the Internet are using the Apache HTTP Server. Apache software packages should be included on your FreeBSD installation media. If you did not install Apache when you first installed FreeBSD, then you can install it from the www/apache13 or www/apache2 port. Once Apache has been installed successfully, it must be configured. This section covers version 1.3.X of the Apache HTTP Server as that is the most widely used version for &os;. Apache 2.X introduces many new technologies but they are not discussed here. For more information about Apache 2.X, please see . Configuration Apache configuration file The main Apache HTTP Server configuration file is installed as /usr/local/etc/apache/httpd.conf on &os;. This file is a typical &unix; text configuration file with comment lines beginning with the # character. A comprehensive description of all possible configuration options is outside the scope of this book, so only the most frequently modified directives will be described here. ServerRoot "/usr/local" This specifies the default directory hierarchy for the Apache installation. Binaries are stored in the - bin and - sbin subdirectories + bin and + sbin subdirectories of the server root, and configuration files are stored in - etc/apache. + etc/apache. ServerAdmin you@your.address The address to which problems with the server should be emailed. This address appears on some server-generated pages, such as error documents. ServerName www.example.com ServerName allows you to set a host name which is sent back to clients for your server if it is different to the one that the host is configured with (i.e., use www instead of the host's real name). DocumentRoot "/usr/local/www/data" DocumentRoot: The directory out of which you will serve your documents. By default, all requests are taken from this directory, but symbolic links and aliases may be used to point to other locations. It is always a good idea to make backup copies of your Apache configuration file before making changes. Once you are satisfied with your initial configuration you are ready to start running Apache. Running <application>Apache</application> Apache starting or stopping Apache does not run from the inetd super server as many other network servers do. It is configured to run standalone for better performance for incoming HTTP requests from client web browsers. A shell script wrapper is included to make starting, stopping, and restarting the server as simple as possible. To start up Apache for the first time, just run: &prompt.root; /usr/local/sbin/apachectl start You can stop the server at any time by typing : &prompt.root; /usr/local/sbin/apachectl stop After making changes to the configuration file for any reason, you will need to restart the server: &prompt.root; /usr/local/sbin/apachectl restart To launch Apache at system startup, add the following line to /etc/rc.conf: apache_enable="YES" If you would like to supply additional command line options for the Apache httpd program started at system boot, you may specify them with an additional line in rc.conf: apache_flags="" Now that the web server is running, you can view your web site by pointing a web browser to http://localhost/. The default web page that is displayed is /usr/local/www/data/index.html. Virtual Hosting Apache supports two different types of Virtual Hosting. The first method is Name-based Virtual Hosting. Name-based virtual hosting uses the clients HTTP/1.1 headers to figure out the hostname. This allows many different domains to share the same IP address. To setup Apache to use Name-based Virtual Hosting add an entry like the following to your httpd.conf: NameVirtualHost * If your webserver was named www.domain.tld and you wanted to setup a virtual domain for www.someotherdomain.tld then you would add the following entries to httpd.conf: <VirtualHost *> ServerName www.domain.tld DocumentRoot /www/domain.tld <VirtualHost> <VirtualHost *> ServerName www.someotherdomain.tld DocumentRoot /www/someotherdomain.tld </VirtualHost> Replace the addresses with the addresses you want to use and the path to the documents with what you are using. For more information about setting up virtual hosts, please consult the official Apache documentation at: Apache Modules Apache modules There are many different Apache modules available to add functionality to the basic server. The FreeBSD Ports Collection provides an easy way to install Apache together with some of the more popular add-on modules. mod_ssl web server secure SSL cryptography The mod_ssl module uses the OpenSSL library to provide strong cryptography via the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols. This module provides everything necessary to request a signed certificate from a trusted certificate signing authority so that you can run a secure web server on &os;. If you have not yet installed Apache, then a version of Apache 1.3.X that includes mod_ssl may be installed with the www/apache13-modssl port. SSL support is also available for Apache 2.X in the www/apache2 port, where it is enabled by default. mod_perl Perl The Apache/Perl integration project brings together the full power of the Perl programming language and the Apache HTTP Server. With the mod_perl module it is possible to write Apache modules entirely in Perl. In addition, the persistent interpreter embedded in the server avoids the overhead of starting an external interpreter and the penalty of Perl start-up time. If you have not yet installed Apache, then a version of Apache that includes mod_perl may be installed with the www/apache13-modperl port. PHP PHP PHP, which stands for PHP: Hypertext Preprocessor is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. Its syntax draws upon C, &java;, and Perl, and is easy to learn. The main goal of the language is to allow web developers to write dynamically generated webpages quickly, but you can do much more with PHP. PHP may be installed from the lang/php5 port. Murray Stokely Contributed by File Transfer Protocol (FTP) FTP server Overview The File Transfer Protocol (FTP) provides users with a simple way to transfer files to and from an FTP server. &os; includes FTP server software, ftpd, in the base system. This makes setting up and administering an FTP server on FreeBSD very straightforward. Configuration The most important configuration step is deciding which accounts will be allowed access to the FTP server. A normal FreeBSD system has a number of system accounts used for various daemons, but unknown users should not be allowed to log in with these accounts. The /etc/ftpusers file is a list of users disallowed any FTP access. By default, it includes the aforementioned system accounts, but it is possible to add specific users here that should not be allowed access to FTP. You may want to restrict the access of some users without preventing them completely from using FTP. This can be accomplished with the /etc/ftpchroot file. This file lists users and groups subject to FTP access restrictions. The &man.ftpchroot.5; manual page has all of the details so it will not be described in detail here. If you would like to enable anonymous FTP access to your server, then you must create a user named ftp on your &os; system. Users will then be able to log on to your FTP server with a username of ftp or anonymous and with any password (by convention an email address for the user should be used as the password). The FTP server will call &man.chroot.2; when an anonymous user logs in, to restrict access to only the home directory of the ftp user. There are two text files that specify welcome messages to be displayed to FTP clients. The contents of the file /etc/ftpwelcome will be displayed to users before they reach the login prompt. After a successful login, the contents of the file /etc/ftpmotd will be displayed. Note that the path to this file is relative to the login environment, so the file ~ftp/etc/ftpmotd would be displayed for anonymous users. Once the FTP server has been configured properly, it must be enabled in /etc/inetd.conf. All that is required here is to remove the comment symbol # from in front of the existing ftpd line : ftp stream tcp nowait root /usr/libexec/ftpd ftpd -l As explained in , a HangUP Signal must be sent to inetd after this configuration file is changed. You can now log on to your FTP server by typing: &prompt.user; ftp localhost Maintaining syslog logs FTP The ftpd daemon uses &man.syslog.3; to log messages. By default, the system log daemon will put messages related to FTP in the /var/log/xferlog file. The location of the FTP log can be modified by changing the following line in /etc/syslog.conf: ftp.info /var/log/xferlog Be aware of the potential problems involved with running an anonymous FTP server. In particular, you should think twice about allowing anonymous users to upload files. You may find that your FTP site becomes a forum for the trade of unlicensed commercial software or worse. If you do need to allow anonymous FTP uploads, then you should set up the permissions so that these files can not be read by other anonymous users until they have been reviewed. Murray Stokely Contributed by File and Print Services for µsoft.windows; clients (Samba) Samba server Microsoft Windows file server Windows clients print server Windows clients Overview Samba is a popular open source software package that provides file and print services for µsoft.windows; clients. Such clients can connect to and use FreeBSD filespace as if it was a local disk drive, or FreeBSD printers as if they were local printers. Samba software packages should be included on your FreeBSD installation media. If you did not install Samba when you first installed FreeBSD, then you can install it from the net/samba3 port or package. Configuration A default Samba configuration file is installed as /usr/local/etc/smb.conf.default. This file must be copied to /usr/local/etc/smb.conf and customized before Samba can be used. The smb.conf file contains runtime configuration information for Samba, such as definitions of the printers and filesystem shares that you would like to share with &windows; clients. The Samba package includes a web based tool called swat which provides a simple way of configuring the smb.conf file. Using the Samba Web Administration Tool (SWAT) The Samba Web Administration Tool (SWAT) runs as a daemon from inetd. Therefore, the following line in /etc/inetd.conf should be uncommented before swat can be used to configure Samba: swat stream tcp nowait/400 root /usr/local/sbin/swat As explained in , a HangUP Signal must be sent to inetd after this configuration file is changed. Once swat has been enabled in inetd.conf, you can use a browser to connect to . You will first have to log on with the system root account. Once you have successfully logged on to the main Samba configuration page, you can browse the system documentation, or begin by clicking on the Globals tab. The Globals section corresponds to the variables that are set in the [global] section of /usr/local/etc/smb.conf. Global Settings Whether you are using swat or editing /usr/local/etc/smb.conf directly, the first directives you are likely to encounter when configuring Samba are: workgroup NT Domain-Name or Workgroup-Name for the computers that will be accessing this server. netbios name NetBIOS This sets the NetBIOS name by which a Samba server is known. By default it is the same as the first component of the host's DNS name. server string This sets the string that will be displayed with the net view command and some other networking tools that seek to display descriptive text about the server. Security Settings Two of the most important settings in /usr/local/etc/smb.conf are the security model chosen, and the backend password format for client users. The following directives control these options: security The two most common options here are security = share and security = user. If your clients use usernames that are the same as their usernames on your &os; machine then you will want to use user level security. This is the default security policy and it requires clients to first log on before they can access shared resources. In share level security, client do not need to log onto the server with a valid username and password before attempting to connect to a shared resource. This was the default security model for older versions of Samba. passdb backend NIS+ LDAP SQL database Samba has several different backend authentication models. You can authenticate clients with LDAP, NIS+, a SQL database, or a modified password file. The default authentication method is smbpasswd, and that is all that will be covered here. Assuming that the default smbpasswd backend is used, the /usr/local/private/smbpasswd file must be created to allow Samba to authenticate clients. If you would like to give all of your &unix; user accounts access from &windows; clients, use the following command: &prompt.root; grep -v "^#" /etc/passwd | make_smbpasswd > /usr/local/private/smbpasswd &prompt.root; chmod 600 /usr/local/private/smbpasswd Please see the Samba documentation for additional information about configuration options. With the basics outlined here, you should have everything you need to start running Samba. Starting <application>Samba</application> To enable Samba when your system boots, add the following line to /etc/rc.conf: samba_enable="YES" You can then start Samba at any time by typing: &prompt.root; /usr/local/etc/rc.d/samba.sh start Starting SAMBA: removing stale tdbs : Starting nmbd. Starting smbd. Samba actually consists of three separate daemons. You should see that both the nmbd and smbd daemons are started by the samba.sh script. If you enabled winbind name resolution services in smb.conf, then you will also see that the winbindd daemon is started. You can stop Samba at any time by typing : &prompt.root; /usr/local/etc/rc.d/samba.sh stop Samba is a complex software suite with functionality that allows broad integration with µsoft.windows; networks. For more information about functionality beyond the basic installation described here, please see . Tom Hukins Contributed by Clock Synchronization with NTP NTP Overview Over time, a computer's clock is prone to drift. The Network Time Protocol (NTP) is one way to ensure your clock stays accurate. Many Internet services rely on, or greatly benefit from, computers' clocks being accurate. For example, a web server may receive requests to send a file if it has been modified since a certain time. In a local area network environment, it is essential that computers sharing files from the same file server have synchronized clocks so that file timestamps stay consistent. Services such as &man.cron.8; also rely on an accurate system clock to run commands at the specified times. NTP ntpd FreeBSD ships with the &man.ntpd.8; NTP server which can be used to query other NTP servers to set the clock on your machine or provide time services to others. Choosing Appropriate NTP Servers NTP choosing servers In order to synchronize your clock, you will need to find one or more NTP servers to use. Your network administrator or ISP may have set up an NTP server for this purpose—check their documentation to see if this is the case. There is an online list of publicly accessible NTP servers which you can use to find an NTP server near to you. Make sure you are aware of the policy for any servers you choose, and ask for permission if required. Choosing several unconnected NTP servers is a good idea in case one of the servers you are using becomes unreachable or its clock is unreliable. &man.ntpd.8; uses the responses it receives from other servers intelligently—it will favor unreliable servers less than reliable ones. Configuring Your Machine NTP configuration Basic Configuration ntpdate If you only wish to synchronize your clock when the machine boots up, you can use &man.ntpdate.8;. This may be appropriate for some desktop machines which are frequently rebooted and only require infrequent synchronization, but most machines should run &man.ntpd.8;. Using &man.ntpdate.8; at boot time is also a good idea for machines that run &man.ntpd.8;. The &man.ntpd.8; program changes the clock gradually, whereas &man.ntpdate.8; sets the clock, no matter how great the difference between a machine's current clock setting and the correct time. To enable &man.ntpdate.8; at boot time, add ntpdate_enable="YES" to /etc/rc.conf. You will also need to specify all servers you wish to synchronize with and any flags to be passed to &man.ntpdate.8; in ntpdate_flags. NTP ntp.conf General Configuration NTP is configured by the /etc/ntp.conf file in the format described in &man.ntp.conf.5;. Here is a simple example: server ntplocal.example.com prefer server timeserver.example.org server ntp2a.example.net driftfile /var/db/ntp.drift The server option specifies which servers are to be used, with one server listed on each line. If a server is specified with the prefer argument, as with ntplocal.example.com, that server is preferred over other servers. A response from a preferred server will be discarded if it differs significantly from other servers' responses, otherwise it will be used without any consideration to other responses. The prefer argument is normally used for NTP servers that are known to be highly accurate, such as those with special time monitoring hardware. The driftfile option specifies which file is used to store the system clock's frequency offset. The &man.ntpd.8; program uses this to automatically compensate for the clock's natural drift, allowing it to maintain a reasonably correct setting even if it is cut off from all external time sources for a period of time. The driftfile option specifies which file is used to store information about previous responses from the NTP servers you are using. This file contains internal information for NTP. It should not be modified by any other process. Controlling Access to Your Server By default, your NTP server will be accessible to all hosts on the Internet. The restrict option in /etc/ntp.conf allows you to control which machines can access your server. If you want to deny all machines from accessing your NTP server, add the following line to /etc/ntp.conf: restrict default ignore If you only want to allow machines within your own network to synchronize their clocks with your server, but ensure they are not allowed to configure the server or used as peers to synchronize against, add restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap instead, where 192.168.1.0 is an IP address on your network and 255.255.255.0 is your network's netmask. /etc/ntp.conf can contain multiple restrict options. For more details, see the Access Control Support subsection of &man.ntp.conf.5;. Running the NTP Server To ensure the NTP server is started at boot time, add the line xntpd_enable="YES" to /etc/rc.conf. If you wish to pass additional flags to &man.ntpd.8;, edit the xntpd_flags parameter in /etc/rc.conf. To start the server without rebooting your machine, run ntpd being sure to specify any additional parameters from xntpd_flags in /etc/rc.conf. For example: &prompt.root; ntpd -p /var/run/ntpd.pid Under &os; 5.X, various options in /etc/rc.conf have been renamed. Thus, you have to replace every instance of xntpd with ntpd in the options above. Using ntpd with a Temporary Internet Connection The &man.ntpd.8; program does not need a permanent connection to the Internet to function properly. However, if you have a temporary connection that is configured to dial out on demand, it is a good idea to prevent NTP traffic from triggering a dial out or keeping the connection alive. If you are using user PPP, you can use filter directives in /etc/ppp/ppp.conf. For example: set filter dial 0 deny udp src eq 123 # Prevent NTP traffic from initiating dial out set filter dial 1 permit 0 0 set filter alive 0 deny udp src eq 123 # Prevent incoming NTP traffic from keeping the connection open set filter alive 1 deny udp dst eq 123 # Prevent outgoing NTP traffic from keeping the connection open set filter alive 2 permit 0/0 0/0 For more details see the PACKET FILTERING section in &man.ppp.8; and the examples in /usr/share/examples/ppp/. Some Internet access providers block low-numbered ports, preventing NTP from functioning since replies never reach your machine. Further Information Documentation for the NTP server can be found in /usr/share/doc/ntp/ in HTML format. diff --git a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml index 4f4344d146..2078899ae6 100644 --- a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml @@ -1,4949 +1,4949 @@ Sean Kelly Contributed by Jim Mock Restructured and updated by Printing Synopsis LPD spooling system printing FreeBSD can be used to print to a wide variety of printers, from the oldest impact printer to the latest laser printers, and everything in between, allowing you to produce high quality printed output from the applications you run. FreeBSD can also be configured to act as a print server on a network; in this capacity FreeBSD can receive print jobs from a variety of other computers, including other FreeBSD computers, &windows; and &macos; hosts. FreeBSD will ensure that one job at a time is printed, and can keep statistics on which users and machines are doing the most printing, produce banner pages showing who's printout is who's, and more. After reading this chapter, you will know: How to configure the FreeBSD print spooler. How to install print filters, to handle special print jobs differently, including converting incoming documents to print formats that your printers understand. How to enable header, or banner pages on your printout. How to print to printers connected to other computers. How to print to printers connected directly to the network. How to control printer restrictions, including limiting the size of print jobs, and preventing certain users from printing. How to keep printer statistics, and account for printer usage. How to troubleshoot printing problems. Before reading this chapter, you should: Know how to configure and install a new kernel (). Introduction In order to use printers with FreeBSD, you will need to set them up to work with the Berkeley line printer spooling system, also known as the LPD spooling system. It is the standard printer control system in FreeBSD. This chapter introduces the LPD spooling system, often simply called LPD, and will guide you through its configuration. If you are already familiar with LPD or another printer spooling system, you may wish to skip to section Setting up the spooling system. LPD controls everything about a host's printers. It is responsible for a number of things: It controls access to attached printers and printers attached to other hosts on the network. print jobs It enables users to submit files to be printed; these submissions are known as jobs. It prevents multiple users from accessing a printer at the same time by maintaining a queue for each printer. It can print header pages (also known as banner or burst pages) so users can easily find jobs they have printed in a stack of printouts. It takes care of communications parameters for printers connected on serial ports. It can send jobs over the network to a LPD spooler on another host. It can run special filters to format jobs to be printed for various printer languages or printer capabilities. It can account for printer usage. Through a configuration file (/etc/printcap), and by providing the special filter programs, you can enable the LPD system to do all or some subset of the above for a great variety of printer hardware. Why You Should Use the Spooler If you are the sole user of your system, you may be wondering why you should bother with the spooler when you do not need access control, header pages, or printer accounting. While it is possible to enable direct access to a printer, you should use the spooler anyway since: LPD prints jobs in the background; you do not have to wait for data to be copied to the printer. &tex; LPD can conveniently run a job to be printed through filters to add date/time headers or convert a special file format (such as a &tex; DVI file) into a format the printer will understand. You will not have to do these steps manually. Many free and commercial programs that provide a print feature usually expect to talk to the spooler on your system. By setting up the spooling system, you will more easily support other software you may later add or already have. Basic Setup To use printers with the LPD spooling system, you will need to set up both your printer hardware and the LPD software. This document describes two levels of setup: See section Simple Printer Setup to learn how to connect a printer, tell LPD how to communicate with it, and print plain text files to the printer. See section Advanced Printer Setup to find out how to print a variety of special file formats, to print header pages, to print across a network, to control access to printers, and to do printer accounting. Simple Printer Setup This section tells how to configure printer hardware and the LPD software to use the printer. It teaches the basics: Section Hardware Setup gives some hints on connecting the printer to a port on your computer. Section Software Setup shows how to set up the LPD spooler configuration file (/etc/printcap). If you are setting up a printer that uses a network protocol to accept data to print instead of a serial or parallel interface, see Printers With Networked Data Stream Interfaces. Although this section is called Simple Printer Setup, it is actually fairly complex. Getting the printer to work with your computer and the LPD spooler is the hardest part. The advanced options like header pages and accounting are fairly easy once you get the printer working. Hardware Setup This section tells about the various ways you can connect a printer to your PC. It talks about the kinds of ports and cables, and also the kernel configuration you may need to enable FreeBSD to speak to the printer. If you have already connected your printer and have successfully printed with it under another operating system, you can probably skip to section Software Setup. Ports and Cables Printers sold for use on PC's today generally come with one or more of the following three interfaces: printers serial Serial interfaces, also known as RS232C or RS232D, or COM ports, use a serial port on your computer to send data to the printer. Serial interfaces are common in the computer industry and cables are readily available and also easy to construct. Serial interfaces sometimes need special cables and might require you to configure somewhat complex communications options. Most PC serial ports have a maximum transmission rate of 115200 bps, which makes printing large graphic print jobs with them impractical. printers parallel Parallel interfaces use a parallel port on your computer to send data to the printer. Parallel interfaces are common in the PC market and are faster than RS232 serial. Cables are readily available but more difficult to construct by hand. There are usually no communications options with parallel interfaces, making their configuration exceedingly simple. centronics parallel printers Parallel interfaces are sometimes known as Centronics interfaces, named after the connector type on the printer. printers USB USB interfaces, named for the Universal Serial Bus, can run at even faster speeds than parallel or RS232 serial interfaces. Cables are simple and cheap. USB is superior to RS232 Serial and to Parallel for printing, but it is not as well supported under &unix; systems. A way to avoid this problem is to purchase a printer that has both a USB interface and a Parallel interface, as many printers do. In general, Parallel interfaces usually offer just one-way communication (computer to printer) while serial and USB gives you two-way. Newer parallel ports (EPP and ECP) and printers can communicate in both directions under FreeBSD when a IEEE1284 compliant cable is used. PostScript Two-way communication to the printer over a parallel port is generally done in one of two ways. The first method uses a custom built printer driver for FreeBSD that speaks the proprietary language used by the printer. This is common with inkjet printers and can be used for reporting ink levels and other status information. The second method is used when the printer supports &postscript;. &postscript; jobs are actually programs sent to the printer; they need not produce paper at all and may return results directly to the computer. &postscript; also uses two-way communication to tell the computer about problems, such as errors in the &postscript; program or paper jams. Your users may be appreciative of such information. Furthermore, the best way to do effective accounting with a &postscript; printer requires two-way communication: you ask the printer for its page count (how many pages it has printed in its lifetime), then send the user's job, then ask again for its page count. Subtract the two values and you know how much paper to charge the user. Parallel Ports To hook up a printer using a parallel interface, connect the Centronics cable between the printer and the computer. The instructions that came with the printer, the computer, or both should give you complete guidance. Remember which parallel port you used on the computer. The first parallel port is /dev/ppc0 to FreeBSD; the second is /dev/ppc1, and so on. The printer device name uses the same scheme: /dev/lpt0 for the printer on the first parallel ports etc. Serial Ports To hook up a printer using a serial interface, connect the proper serial cable between the printer and the computer. The instructions that came with the printer, the computer, or both should give you complete guidance. If you are unsure what the proper serial cable is, you may wish to try one of the following alternatives: A modem cable connects each pin of the connector on one end of the cable straight through to its corresponding pin of the connector on the other end. This type of cable is also known as a DTE-to-DCE cable. null-modem cable A null-modem cable connects some pins straight through, swaps others (send data to receive data, for example), and shorts some internally in each connector hood. This type of cable is also known as a DTE-to-DTE cable. A serial printer cable, required for some unusual printers, is like the null-modem cable, but sends some signals to their counterparts instead of being internally shorted. baud rate parity flow control protocol You should also set up the communications parameters for the printer, usually through front-panel controls or DIP switches on the printer. Choose the highest bps (bits per second, sometimes baud rate) rate that both your computer and the printer can support. Choose 7 or 8 data bits; none, even, or odd parity; and 1 or 2 stop bits. Also choose a flow control protocol: either none, or XON/XOFF (also known as in-band or software) flow control. Remember these settings for the software configuration that follows. Software Setup This section describes the software setup necessary to print with the LPD spooling system in FreeBSD. Here is an outline of the steps involved: Configure your kernel, if necessary, for the port you are using for the printer; section Kernel Configuration tells you what you need to do. Set the communications mode for the parallel port, if you are using a parallel port; section Setting the Communication Mode for the Parallel Port gives details. Test if the operating system can send data to the printer. Section Checking Printer Communications gives some suggestions on how to do this. Set up LPD for the printer by modifying the file /etc/printcap. You will find out how to do this later in this chapter. Kernel Configuration The operating system kernel is compiled to work with a specific set of devices. The serial or parallel interface for your printer is a part of that set. Therefore, it might be necessary to add support for an additional serial or parallel port if your kernel is not already configured for one. To find out if the kernel you are currently using supports a serial interface, type: &prompt.root; grep sioN /var/run/dmesg.boot Where N is the number of the serial port, starting from zero. If you see output similar to the following: sio2 at port 0x3e8-0x3ef irq 5 on isa sio2: type 16550A then the kernel supports the port. To find out if the kernel supports a parallel interface, type: &prompt.root; grep ppcN /var/run/dmesg.boot Where N is the number of the parallel port, starting from zero. If you see output similar to the following: ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/8 bytes threshold then the kernel supports the port. You might have to reconfigure your kernel in order for the operating system to recognize and use the parallel or serial port you are using for the printer. To add support for a serial port, see the section on kernel configuration. To add support for a parallel port, see that section and the section that follows. Adding <filename>/dev</filename> Entries for the Ports FreeBSD 5.0 includes the devfs filesystem which automatically creates device nodes as needed. If you are running a version of FreeBSD with devfs enabled then you can safely skip this section. Even though the kernel may support communication along a serial or parallel port, you will still need a software interface through which programs running on the system can send and receive data. That is what entries in the /dev directory are for. To add a /dev entry for a port: Become root with the &man.su.1; command. Enter the root password when prompted. Change to the /dev directory: &prompt.root; cd /dev Type: &prompt.root; ./MAKEDEV port Where port is the device entry for the port you want to make. Use lpt0 for the printer on the first parallel port, lpt1 for the printer on the second port, and so on; use ttyd0 for the first serial port, ttyd1 for the second, and so on. Type: &prompt.root; ls -l port to make sure the device entry got created. Setting the Communication Mode for the Parallel Port When you are using the parallel interface, you can choose whether FreeBSD should use interrupt-driven or polled communication with the printer. The generic printer device driver (&man.lpt.4;) on FreeBSD 4.X and 5.X uses the &man.ppbus.4; system, which controls the port chipset with the &man.ppc.4; driver. The interrupt-driven method is the default with the GENERIC kernel. With this method, the operating system uses an IRQ line to determine when the printer is ready for data. The polled method directs the operating system to repeatedly ask the printer if it is ready for more data. When it responds ready, the kernel sends more data. The interrupt-driven method is usually somewhat faster but uses up a precious IRQ line. Some newer HP printers are claimed not to work correctly in interrupt mode, apparently due to some (not yet exactly understood) timing problem. These printers need polled mode. You should use whichever one works. Some printers will work in both modes, but are painfully slow in interrupt mode. You can set the communications mode in two ways: by configuring the kernel or by using the &man.lptcontrol.8; program. To set the communications mode by configuring the kernel: Edit your kernel configuration file. Look for an ppc0 entry. If you are setting up the second parallel port, use ppc1 instead. Use ppc2 for the third port, and so on. If you want interrupt-driven mode, for FreeBSD 4.X add the irq specifier: device ppc0 at isa? irq N Where N is the IRQ number for your computer's parallel port. For FreeBSD 5.X, edit the following line: hint.ppc.0.irq="N" in the /boot/device.hints file and replace N with the right IRQ number. The kernel configuration file must also contain the &man.ppc.4; driver: device ppc If you want polled mode, do not add the irq specifier: For FreeBSD 4.X, use the following line in your kernel configuration file: device ppc0 at isa? For FreeBSD 5.X, simply remove in your /boot/device.hints file, the following line: hint.ppc.0.irq="N" In some cases, this is not enough to put the port in polled mode under FreeBSD 5.X. Most of time it comes from &man.acpi.4; driver, this latter is able to probe and attach devices, and therefore, control the access mode to the printer port. You should check your &man.acpi.4; configuration to correct this problem. Save the file. Then configure, build, and install the kernel, then reboot. See kernel configuration for more details. To set the communications mode with &man.lptcontrol.8;: Type: &prompt.root; lptcontrol -i -d /dev/lptN to set interrupt-driven mode for lptN. Type: &prompt.root; lptcontrol -p -d /dev/lptN to set polled-mode for lptN. You could put these commands in your /etc/rc.local file to set the mode each time your system boots. See &man.lptcontrol.8; for more information. Checking Printer Communications Before proceeding to configure the spooling system, you should make sure the operating system can successfully send data to your printer. It is a lot easier to debug printer communication and the spooling system separately. To test the printer, we will send some text to it. For printers that can immediately print characters sent to them, the program &man.lptest.1; is perfect: it generates all 96 printable ASCII characters in 96 lines. PostScript For a &postscript; (or other language-based) printer, we will need a more sophisticated test. A small &postscript; program, such as the following, will suffice: %!PS 100 100 moveto 300 300 lineto stroke 310 310 moveto /Helvetica findfont 12 scalefont setfont (Is this thing working?) show showpage The above &postscript; code can be placed into a file and used as shown in the examples appearing in the following sections. PCL When this document refers to a printer language, it is assuming a language like &postscript;, and not Hewlett Packard's PCL. Although PCL has great functionality, you can intermingle plain text with its escape sequences. &postscript; cannot directly print plain text, and that is the kind of printer language for which we must make special accommodations. Checking a Parallel Printer printers parallel This section tells you how to check if FreeBSD can communicate with a printer connected to a parallel port. To test a printer on a parallel port: Become root with &man.su.1;. Send data to the printer. If the printer can print plain text, then use &man.lptest.1;. Type: &prompt.root; lptest > /dev/lptN Where N is the number of the parallel port, starting from zero. If the printer understands &postscript; or other printer language, then send a small program to the printer. Type: &prompt.root; cat > /dev/lptN Then, line by line, type the program carefully as you cannot edit a line once you have pressed RETURN or ENTER. When you have finished entering the program, press CONTROL+D, or whatever your end of file key is. Alternatively, you can put the program in a file and type: &prompt.root; cat file > /dev/lptN Where file is the name of the file containing the program you want to send to the printer. You should see something print. Do not worry if the text does not look right; we will fix such things later. Checking a Serial Printer printers serial This section tells you how to check if FreeBSD can communicate with a printer on a serial port. To test a printer on a serial port: Become root with &man.su.1;. Edit the file /etc/remote. Add the following entry: printer:dv=/dev/port:br#bps-rate:pa=parity bits-per-second serial port parity Where port is the device entry for the serial port (ttyd0, ttyd1, etc.), bps-rate is the bits-per-second rate at which the printer communicates, and parity is the parity required by the printer (either even, odd, none, or zero). Here is a sample entry for a printer connected via a serial line to the third serial port at 19200 bps with no parity: printer:dv=/dev/ttyd2:br#19200:pa=none Connect to the printer with &man.tip.1;. Type: &prompt.root; tip printer If this step does not work, edit the file /etc/remote again and try using /dev/cuaaN instead of /dev/ttydN. Send data to the printer. If the printer can print plain text, then use &man.lptest.1;. Type: &prompt.user; $lptest If the printer understands &postscript; or other printer language, then send a small program to the printer. Type the program, line by line, very carefully as backspacing or other editing keys may be significant to the printer. You may also need to type a special end-of-file key for the printer so it knows it received the whole program. For &postscript; printers, press CONTROL+D. Alternatively, you can put the program in a file and type: &prompt.user; >file Where file is the name of the file containing the program. After &man.tip.1; sends the file, press any required end-of-file key. You should see something print. Do not worry if the text does not look right; we will fix that later. Enabling the Spooler: the <filename>/etc/printcap</filename> File At this point, your printer should be hooked up, your kernel configured to communicate with it (if necessary), and you have been able to send some simple data to the printer. Now, we are ready to configure LPD to control access to your printer. You configure LPD by editing the file /etc/printcap. The LPD spooling system reads this file each time the spooler is used, so updates to the file take immediate effect. printers capabilities The format of the &man.printcap.5; file is straightforward. Use your favorite text editor to make changes to /etc/printcap. The format is identical to other capability files like /usr/share/misc/termcap and /etc/remote. For complete information about the format, see the &man.cgetent.3;. The simple spooler configuration consists of the following steps: Pick a name (and a few convenient aliases) for the printer, and put them in the /etc/printcap file; see the Naming the Printer section for more information on naming. header pages Turn off header pages (which are on by default) by inserting the sh capability; see the Suppressing Header Pages section for more information. Make a spooling directory, and specify its location with the sd capability; see the Making the Spooling Directory section for more information. Set the /dev entry to use for the printer, and note it in /etc/printcap with the lp capability; see the Identifying the Printer Device for more information. Also, if the printer is on a serial port, set up the communication parameters with the ms# capability which is discussed in the Configuring Spooler Communications Parameters section. Install a plain text input filter; see the Installing the Text Filter section for details. Test the setup by printing something with the &man.lpr.1; command. More details are available in the Trying It Out and Troubleshooting sections. Language-based printers, such as &postscript; printers, cannot directly print plain text. The simple setup outlined above and described in the following sections assumes that if you are installing such a printer you will print only files that the printer can understand. Users often expect that they can print plain text to any of the printers installed on your system. Programs that interface to LPD to do their printing usually make the same assumption. If you are installing such a printer and want to be able to print jobs in the printer language and print plain text jobs, you are strongly urged to add an additional step to the simple setup outlined above: install an automatic plain-text-to-&postscript; (or other printer language) conversion program. The section entitled Accommodating Plain Text Jobs on &postscript; Printers tells how to do this. Naming the Printer The first (easy) step is to pick a name for your printer It really does not matter whether you choose functional or whimsical names since you can also provide a number of aliases for the printer. At least one of the printers specified in the /etc/printcap should have the alias lp. This is the default printer's name. If users do not have the PRINTER environment variable nor specify a printer name on the command line of any of the LPD commands, then lp will be the default printer they get to use. Also, it is common practice to make the last alias for a printer be a full description of the printer, including make and model. Once you have picked a name and some common aliases, put them in the /etc/printcap file. The name of the printer should start in the leftmost column. Separate each alias with a vertical bar and put a colon after the last alias. In the following example, we start with a skeletal /etc/printcap that defines two printers (a Diablo 630 line printer and a Panasonic KX-P4455 &postscript; laser printer): # # /etc/printcap for host rose # rattan|line|diablo|lp|Diablo 630 Line Printer: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4: In this example, the first printer is named rattan and has as aliases line, diablo, lp, and Diablo 630 Line Printer. Since it has the alias lp, it is also the default printer. The second is named bamboo, and has as aliases ps, PS, S, panasonic, and Panasonic KX-P4455 PostScript v51.4. Suppressing Header Pages printing header pages The LPD spooling system will by default print a header page for each job. The header page contains the user name who requested the job, the host from which the job came, and the name of the job, in nice large letters. Unfortunately, all this extra text gets in the way of debugging the simple printer setup, so we will suppress header pages. To suppress header pages, add the sh capability to the entry for the printer in /etc/printcap. Here is an example /etc/printcap with sh added: # # /etc/printcap for host rose - no header pages anywhere # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh: Note how we used the correct format: the first line starts in the leftmost column, and subsequent lines are indented with a single TAB. Every line in an entry except the last ends in a backslash character. Making the Spooling Directory printer spool print jobs The next step in the simple spooler setup is to make a spooling directory, a directory where print jobs reside until they are printed, and where a number of other spooler support files live. Because of the variable nature of spooling directories, it is customary to put these directories under /var/spool. It is not necessary to backup the contents of spooling directories, either. Recreating them is as simple as running &man.mkdir.1;. It is also customary to make the directory with a name that is identical to the name of the printer, as shown below: &prompt.root; mkdir /var/spool/printer-name However, if you have a lot of printers on your network, you might want to put the spooling directories under a single directory that you reserve just for printing with LPD. We will do this for our two example printers rattan and bamboo: &prompt.root; mkdir /var/spool/lpd &prompt.root; mkdir /var/spool/lpd/rattan &prompt.root; mkdir /var/spool/lpd/bamboo If you are concerned about the privacy of jobs that users print, you might want to protect the spooling directory so it is not publicly accessible. Spooling directories should be owned and be readable, writable, and searchable by user daemon and group daemon, and no one else. We will do this for our example printers: &prompt.root; chown daemon:daemon /var/spool/lpd/rattan &prompt.root; chown daemon:daemon /var/spool/lpd/bamboo &prompt.root; chmod 770 /var/spool/lpd/rattan &prompt.root; chmod 770 /var/spool/lpd/bamboo Finally, you need to tell LPD about these directories using the /etc/printcap file. You specify the pathname of the spooling directory with the sd capability: # # /etc/printcap for host rose - added spooling directories # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo: Note that the name of the printer starts in the first column but all other entries describing the printer should be indented with a tab and each line escaped with a backslash. If you do not specify a spooling directory with sd, the spooling system will use /var/spool/lpd as a default. Identifying the Printer Device In the Adding /dev Entries for the Ports section, we identified which entry in the /dev directory FreeBSD will use to communicate with the printer. Now, we tell LPD that information. When the spooling system has a job to print, it will open the specified device on behalf of the filter program (which is responsible for passing data to the printer). List the /dev entry pathname in the /etc/printcap file using the lp capability. In our running example, let us assume that rattan is on the first parallel port, and bamboo is on a sixth serial port; here are the additions to /etc/printcap: # # /etc/printcap for host rose - identified what devices to use # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5: If you do not specify the lp capability for a printer in your /etc/printcap file, LPD uses /dev/lp as a default. /dev/lp currently does not exist in FreeBSD. If the printer you are installing is connected to a parallel port, skip to the section entitled, Installing the Text Filter. Otherwise, be sure to follow the instructions in the next section. Configuring Spooler Communication Parameters printers serial For printers on serial ports, LPD can set up the bps rate, parity, and other serial communication parameters on behalf of the filter program that sends data to the printer. This is advantageous since: It lets you try different communication parameters by simply editing the /etc/printcap file; you do not have to recompile the filter program. It enables the spooling system to use the same filter program for multiple printers which may have different serial communication settings. The following /etc/printcap capabilities control serial communication parameters of the device listed in the lp capability: br#bps-rate Sets the communications speed of the device to bps-rate, where bps-rate can be 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, or 115200 bits-per-second. ms#stty-mode Sets the options for the terminal device after opening the device. &man.stty.1; explains the available options. When LPD opens the device specified by the lp capability, it sets the characteristics of the device to those specified with the ms# capability. Of particular interest will be the parenb, parodd, cs5, cs6, cs7, cs8, cstopb, crtscts, and ixon modes, which are explained in the &man.stty.1; manual page. Let us add to our example printer on the sixth serial port. We will set the bps rate to 38400. For the mode, we will set no parity with -parenb, 8-bit characters with cs8, no modem control with clocal and hardware flow control with crtscts: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts: Installing the Text Filter printing filters We are now ready to tell LPD what text filter to use to send jobs to the printer. A text filter, also known as an input filter, is a program that LPD runs when it has a job to print. When LPD runs the text filter for a printer, it sets the filter's standard input to the job to print, and its standard output to the printer device specified with the lp capability. The filter is expected to read the job from standard input, perform any necessary translation for the printer, and write the results to standard output, which will get printed. For more information on the text filter, see the Filters section. For our simple printer setup, the text filter can be a small shell script that just executes /bin/cat to send the job to the printer. FreeBSD comes with another filter called lpf that handles backspacing and underlining for printers that might not deal with such character streams well. And, of course, you can use any other filter program you want. The filter lpf is described in detail in section entitled lpf: a Text Filter. First, let us make the shell script /usr/local/libexec/if-simple be a simple text filter. Put the following text into that file with your favorite text editor: #!/bin/sh # # if-simple - Simple text input filter for lpd # Installed in /usr/local/libexec/if-simple # # Simply copies stdin to stdout. Ignores all filter arguments. /bin/cat && exit 0 exit 2 Make the file executable: &prompt.root; chmod 555 /usr/local/libexec/if-simple And then tell LPD to use it by specifying it with the if capability in /etc/printcap. We will add it to the two printers we have so far in the example /etc/printcap: # # /etc/printcap for host rose - added text filter # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:\ :if=/usr/local/libexec/if-simple: A copy of the if-simple script can be found in the /usr/share/examples/printing + class="directory">/usr/share/examples/printing directory. Turn on <application>LPD</application> &man.lpd.8; is run from /etc/rc, controlled by the lpd_enable variable. This variable defaults to NO. If you have not done so already, add the line: lpd_enable="YES" to /etc/rc.conf, and then either restart your machine, or just run &man.lpd.8;. &prompt.root; lpd Trying It Out You have reached the end of the simple LPD setup. Unfortunately, congratulations are not quite yet in order, since we still have to test the setup and correct any problems. To test the setup, try printing something. To print with the LPD system, you use the command &man.lpr.1;, which submits a job for printing. You can combine &man.lpr.1; with the &man.lptest.1; program, introduced in section Checking Printer Communications to generate some test text. To test the simple LPD setup: Type: &prompt.root; lptest 20 5 | lpr -Pprinter-name Where printer-name is a the name of a printer (or an alias) specified in /etc/printcap. To test the default printer, type &man.lpr.1; without any argument. Again, if you are testing a printer that expects &postscript;, send a &postscript; program in that language instead of using &man.lptest.1;. You can do so by putting the program in a file and typing lpr file. For a &postscript; printer, you should get the results of the program. If you are using &man.lptest.1;, then your results should look like the following: !"#$%&'()*+,-./01234 "#$%&'()*+,-./012345 #$%&'()*+,-./0123456 $%&'()*+,-./01234567 %&'()*+,-./012345678 To further test the printer, try downloading larger programs (for language-based printers) or running &man.lptest.1; with different arguments. For example, lptest 80 60 will produce 60 lines of 80 characters each. If the printer did not work, see the Troubleshooting section. Advanced Printer Setup This section describes filters for printing specially formatted files, header pages, printing across networks, and restricting and accounting for printer usage. Filters printing filters Although LPD handles network protocols, queuing, access control, and other aspects of printing, most of the real work happens in the filters. Filters are programs that communicate with the printer and handle its device dependencies and special requirements. In the simple printer setup, we installed a plain text filter—an extremely simple one that should work with most printers (section Installing the Text Filter). However, in order to take advantage of format conversion, printer accounting, specific printer quirks, and so on, you should understand how filters work. It will ultimately be the filter's responsibility to handle these aspects. And the bad news is that most of the time you have to provide filters yourself. The good news is that many are generally available; when they are not, they are usually easy to write. Also, FreeBSD comes with one, /usr/libexec/lpr/lpf, that works with many printers that can print plain text. (It handles backspacing and tabs in the file, and does accounting, but that is about all it does.) There are also several filters and filter components in the FreeBSD Ports Collection. Here is what you will find in this section: Section How Filters Work, tries to give an overview of a filter's role in the printing process. You should read this section to get an understanding of what is happening under the hood when LPD uses filters. This knowledge could help you anticipate and debug problems you might encounter as you install more and more filters on each of your printers. LPD expects every printer to be able to print plain text by default. This presents a problem for &postscript; (or other language-based printers) which cannot directly print plain text. Section Accommodating Plain Text Jobs on &postscript; Printers tells you what you should do to overcome this problem. You should read this section if you have a &postscript; printer. &postscript; is a popular output format for many programs. Some people even write &postscript; code directly. Unfortunately, &postscript; printers are expensive. Section Simulating &postscript; on Non &postscript; Printers tells how you can further modify a printer's text filter to accept and print &postscript; data on a non &postscript; printer. You should read this section if you do not have a &postscript; printer. Section Conversion Filters tells about a way you can automate the conversion of specific file formats, such as graphic or typesetting data, into formats your printer can understand. After reading this section, you should be able to set up your printers such that users can type lpr -t to print troff data, or lpr -d to print &tex; DVI data, or lpr -v to print raster image data, and so forth. I recommend reading this section. Section Output Filters tells all about a not often used feature of LPD: output filters. Unless you are printing header pages (see Header Pages), you can probably skip that section altogether. Section lpf: a Text Filter describes lpf, a fairly complete if simple text filter for line printers (and laser printers that act like line printers) that comes with FreeBSD. If you need a quick way to get printer accounting working for plain text, or if you have a printer which emits smoke when it sees backspace characters, you should definitely consider lpf. A copy of the various scripts described below can be found in the /usr/share/examples/printing + class="directory">/usr/share/examples/printing directory. How Filters Work As mentioned before, a filter is an executable program started by LPD to handle the device-dependent part of communicating with the printer. When LPD wants to print a file in a job, it starts a filter program. It sets the filter's standard input to the file to print, its standard output to the printer, and its standard error to the error logging file (specified in the lf capability in /etc/printcap, or /dev/console by default). troff Which filter LPD starts and the filter's arguments depend on what is listed in the /etc/printcap file and what arguments the user specified for the job on the &man.lpr.1; command line. For example, if the user typed lpr -t, LPD would start the troff filter, listed in the tf capability for the destination printer. If the user wanted to print plain text, it would start the if filter (this is mostly true: see Output Filters for details). There are three kinds of filters you can specify in /etc/printcap: The text filter, confusingly called the input filter in LPD documentation, handles regular text printing. Think of it as the default filter. LPD expects every printer to be able to print plain text by default, and it is the text filter's job to make sure backspaces, tabs, or other special characters do not confuse the printer. If you are in an environment where you have to account for printer usage, the text filter must also account for pages printed, usually by counting the number of lines printed and comparing that to the number of lines per page the printer supports. The text filter is started with the following argument list: filter-name -c -wwidth -llength -iindent -n login -h host acct-file where appears if the job is submitted with lpr -l width is the value from the pw (page width) capability specified in /etc/printcap, default 132 length is the value from the pl (page length) capability, default 66 indent is the amount of the indentation from lpr -i, default 0 login is the account name of the user printing the file host is the host name from which the job was submitted acct-file is the name of the accounting file from the af capability. printing filters A conversion filter converts a specific file format into one the printer can render onto paper. For example, ditroff typesetting data cannot be directly printed, but you can install a conversion filter for ditroff files to convert the ditroff data into a form the printer can digest and print. Section Conversion Filters tells all about them. Conversion filters also need to do accounting, if you need printer accounting. Conversion filters are started with the following arguments: filter-name -xpixel-width -ypixel-height -n login -h host acct-file where pixel-width is the value from the px capability (default 0) and pixel-height is the value from the py capability (default 0). The output filter is used only if there is no text filter, or if header pages are enabled. In my experience, output filters are rarely used. Section Output Filters describe them. There are only two arguments to an output filter: filter-name -wwidth -llength which are identical to the text filters and arguments. Filters should also exit with the following exit status: exit 0 If the filter printed the file successfully. exit 1 If the filter failed to print the file but wants LPD to try to print the file again. LPD will restart a filter if it exits with this status. exit 2 If the filter failed to print the file and does not want LPD to try again. LPD will throw out the file. The text filter that comes with the FreeBSD release, /usr/libexec/lpr/lpf, takes advantage of the page width and length arguments to determine when to send a form feed and how to account for printer usage. It uses the login, host, and accounting file arguments to make the accounting entries. If you are shopping for filters, see if they are LPD-compatible. If they are, they must support the argument lists described above. If you plan on writing filters for general use, then have them support the same argument lists and exit codes. Accommodating Plain Text Jobs on &postscript; Printers print jobs If you are the only user of your computer and &postscript; (or other language-based) printer, and you promise to never send plain text to your printer and to never use features of various programs that will want to send plain text to your printer, then you do not need to worry about this section at all. But, if you would like to send both &postscript; and plain text jobs to the printer, then you are urged to augment your printer setup. To do so, we have the text filter detect if the arriving job is plain text or &postscript;. All &postscript; jobs must start with %! (for other printer languages, see your printer documentation). If those are the first two characters in the job, we have &postscript;, and can pass the rest of the job directly. If those are not the first two characters in the file, then the filter will convert the text into &postscript; and print the result. How do we do this? printers serial If you have got a serial printer, a great way to do it is to install lprps. lprps is a &postscript; printer filter which performs two-way communication with the printer. It updates the printer's status file with verbose information from the printer, so users and administrators can see exactly what the state of the printer is (such as toner low or paper jam). But more importantly, it includes a program called psif which detects whether the incoming job is plain text and calls textps (another program that comes with lprps) to convert it to &postscript;. It then uses lprps to send the job to the printer. lprps is part of the FreeBSD Ports Collection (see The Ports Collection). You can fetch, build and install it yourself, of course. After installing lprps, just specify the pathname to the psif program that is part of lprps. If you installed lprps from the ports collection, use the following in the serial &postscript; printer's entry in /etc/printcap: :if=/usr/local/libexec/psif: You should also specify the rw capability; that tells LPD to open the printer in read-write mode. If you have a parallel &postscript; printer (and therefore cannot use two-way communication with the printer, which lprps needs), you can use the following shell script as the text filter: #!/bin/sh # # psif - Print PostScript or plain text on a PostScript printer # Script version; NOT the version that comes with lprps # Installed in /usr/local/libexec/psif # IFS="" read -r first_line first_two_chars=`expr "$first_line" : '\(..\)'` if [ "$first_two_chars" = "%!" ]; then # # PostScript job, print it. # echo "$first_line" && cat && printf "\004" && exit 0 exit 2 else # # Plain text, convert it, then print it. # ( echo "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 exit 2 fi In the above script, textps is a program we installed separately to convert plain text to &postscript;. You can use any text-to-&postscript; program you wish. The FreeBSD Ports Collection (see The Ports Collection) includes a full featured text-to-&postscript; program called a2ps that you might want to investigate. Simulating &postscript; on Non &postscript; Printers PostScript emulating Ghostscript &postscript; is the de facto standard for high quality typesetting and printing. &postscript; is, however, an expensive standard. Thankfully, Aladdin Enterprises has a free &postscript; work-alike called Ghostscript that runs with FreeBSD. Ghostscript can read most &postscript; files and can render their pages onto a variety of devices, including many brands of non-PostScript printers. By installing Ghostscript and using a special text filter for your printer, you can make your non &postscript; printer act like a real &postscript; printer. Ghostscript is in the FreeBSD Ports Collection, if you would like to install it from there. You can fetch, build, and install it quite easily yourself, as well. To simulate &postscript;, we have the text filter detect if it is printing a &postscript; file. If it is not, then the filter will pass the file directly to the printer; otherwise, it will use Ghostscript to first convert the file into a format the printer will understand. Here is an example: the following script is a text filter for Hewlett Packard DeskJet 500 printers. For other printers, substitute the argument to the gs (Ghostscript) command. (Type gs -h to get a list of devices the current installation of Ghostscript supports.) #!/bin/sh # # ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 # Installed in /usr/local/libexec/ifhp # # Treat LF as CR+LF (to avoid the "staircase effect" on HP/PCL # printers): # printf "\033&k2G" || exit 2 # # Read first two characters of the file # IFS="" read -r first_line first_two_chars=`expr "$first_line" : '\(..\)'` if [ "$first_two_chars" = "%!" ]; then # # It is PostScript; use Ghostscript to scan-convert and print it. # /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ -sOutputFile=- - && exit 0 else # # Plain text or HP/PCL, so just print it directly; print a form feed # at the end to eject the last page. # echo "$first_line" && cat && printf "\033&l0H" && exit 0 fi exit 2 Finally, you need to notify LPD of the filter via the if capability: :if=/usr/local/libexec/ifhp: That is it. You can type lpr plain.text and lpr whatever.ps and both should print successfully. Conversion Filters After completing the simple setup described in Simple Printer Setup, the first thing you will probably want to do is install conversion filters for your favorite file formats (besides plain ASCII text). Why Install Conversion Filters? &tex; printing dvi files Conversion filters make printing various kinds of files easy. As an example, suppose we do a lot of work with the &tex; typesetting system, and we have a &postscript; printer. Every time we generate a DVI file from &tex;, we cannot print it directly until we convert the DVI file into &postscript;. The command sequence goes like this: &prompt.user; dvips seaweed-analysis.dvi &prompt.user; lpr seaweed-analysis.ps By installing a conversion filter for DVI files, we can skip the hand conversion step each time by having LPD do it for us. Now, each time we get a DVI file, we are just one step away from printing it: &prompt.user; lpr -d seaweed-analysis.dvi We got LPD to do the DVI file conversion for us by specifying the option. Section Formatting and Conversion Options lists the conversion options. For each of the conversion options you want a printer to support, install a conversion filter and specify its pathname in /etc/printcap. A conversion filter is like the text filter for the simple printer setup (see section Installing the Text Filter) except that instead of printing plain text, the filter converts the file into a format the printer can understand. Which Conversions Filters Should I Install? You should install the conversion filters you expect to use. If you print a lot of DVI data, then a DVI conversion filter is in order. If you have got plenty of troff to print out, then you probably want a troff filter. The following table summarizes the filters that LPD works with, their capability entries for the /etc/printcap file, and how to invoke them with the lpr command: File type /etc/printcap capability lpr option cifplot cf DVI df plot gf ditroff nf FORTRAN text rf troff tf raster vf plain text if none, , or In our example, using lpr -d means the printer needs a df capability in its entry in /etc/printcap. FORTRAN Despite what others might contend, formats like FORTRAN text and plot are probably obsolete. At your site, you can give new meanings to these or any of the formatting options just by installing custom filters. For example, suppose you would like to directly print Printerleaf files (files from the Interleaf desktop publishing program), but will never print plot files. You could install a Printerleaf conversion filter under the gf capability and then educate your users that lpr -g mean print Printerleaf files. Installing Conversion Filters Since conversion filters are programs you install outside of the base FreeBSD installation, they should probably go under /usr/local. The directory /usr/local/libexec is a popular location, since they are specialized programs that only LPD will run; regular users should not ever need to run them. To enable a conversion filter, specify its pathname under the appropriate capability for the destination printer in /etc/printcap. In our example, we will add the DVI conversion filter to the entry for the printer named bamboo. Here is the example /etc/printcap file again, with the new df capability for the printer bamboo. # # /etc/printcap for host rose - added df filter for bamboo # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:rw:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: The DVI filter is a shell script named /usr/local/libexec/psdf. Here is that script: #!/bin/sh # # psdf - DVI to PostScript printer filter # Installed in /usr/local/libexec/psdf # # Invoked by lpd when user runs lpr -d # exec /usr/local/bin/dvips -f | /usr/local/libexec/lprps "$@" This script runs dvips in filter mode (the argument) on standard input, which is the job to print. It then starts the &postscript; printer filter lprps (see section Accommodating Plain Text Jobs on &postscript; Printers) with the arguments LPD passed to this script. lprps will use those arguments to account for the pages printed. More Conversion Filter Examples Since there is no fixed set of steps to install conversion filters, let me instead provide more examples. Use these as guidance to making your own filters. Use them directly, if appropriate. This example script is a raster (well, GIF file, actually) conversion filter for a Hewlett Packard LaserJet III-Si printer: #!/bin/sh # # hpvf - Convert GIF files into HP/PCL, then print # Installed in /usr/local/libexec/hpvf PATH=/usr/X11R6/bin:$PATH; export PATH giftopnm | ppmtopgm | pgmtopbm | pbmtolj -resolution 300 \ && exit 0 \ || exit 2 It works by converting the GIF file into a portable anymap, converting that into a portable graymap, converting that into a portable bitmap, and converting that into LaserJet/PCL-compatible data. Here is the /etc/printcap file with an entry for a printer using the above filter: # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif:\ :vf=/usr/local/libexec/hpvf: The following script is a conversion filter for troff data from the groff typesetting system for the &postscript; printer named bamboo: #!/bin/sh # # pstf - Convert groff's troff data into PS, then print. # Installed in /usr/local/libexec/pstf # exec grops | /usr/local/libexec/lprps "$@" The above script makes use of lprps again to handle the communication with the printer. If the printer were on a parallel port, we would use this script instead: #!/bin/sh # # pstf - Convert groff's troff data into PS, then print. # Installed in /usr/local/libexec/pstf # exec grops That is it. Here is the entry we need to add to /etc/printcap to enable the filter: :tf=/usr/local/libexec/pstf: Here is an example that might make old hands at FORTRAN blush. It is a FORTRAN-text filter for any printer that can directly print plain text. We will install it for the printer teak: #!/bin/sh # # hprf - FORTRAN text filter for LaserJet 3si: # Installed in /usr/local/libexec/hprf # printf "\033&k2G" && fpr && printf "\033&l0H" && exit 0 exit 2 And we will add this line to the /etc/printcap for the printer teak to enable this filter: :rf=/usr/local/libexec/hprf: Here is one final, somewhat complex example. We will add a DVI filter to the LaserJet printer teak introduced earlier. First, the easy part: updating /etc/printcap with the location of the DVI filter: :df=/usr/local/libexec/hpdf: Now, for the hard part: making the filter. For that, we need a DVI-to-LaserJet/PCL conversion program. The FreeBSD Ports Collection (see The Ports Collection) has one: dvi2xx is the name of the package. Installing this package gives us the program we need, dvilj2p, which converts DVI into LaserJet IIp, LaserJet III, and LaserJet 2000 compatible codes. dvilj2p makes the filter hpdf quite complex since dvilj2p cannot read from standard input. It wants to work with a filename. What is worse, the filename has to end in .dvi so using /dev/fd/0 for standard input is problematic. We can get around that problem by linking (symbolically) a temporary file name (one that ends in .dvi) to /dev/fd/0, thereby forcing dvilj2p to read from standard input. The only other fly in the ointment is the fact that we cannot use /tmp for the temporary link. Symbolic links are owned by user and group bin. The filter runs as user daemon. And the /tmp directory has the sticky bit set. The filter can create the link, but it will not be able clean up when done and remove it since the link will belong to a different user. Instead, the filter will make the symbolic link in the current working directory, which is the spooling directory (specified by the sd capability in /etc/printcap). This is a perfect place for filters to do their work, especially since there is (sometimes) more free disk space in the spooling directory than under /tmp. Here, finally, is the filter: #!/bin/sh # # hpdf - Print DVI data on HP/PCL printer # Installed in /usr/local/libexec/hpdf PATH=/usr/local/bin:$PATH; export PATH # # Define a function to clean up our temporary files. These exist # in the current directory, which will be the spooling directory # for the printer. # cleanup() { rm -f hpdf$$.dvi } # # Define a function to handle fatal errors: print the given message # and exit 2. Exiting with 2 tells LPD to do not try to reprint the # job. # fatal() { echo "$@" 1>&2 cleanup exit 2 } # # If user removes the job, LPD will send SIGINT, so trap SIGINT # (and a few other signals) to clean up after ourselves. # trap cleanup 1 2 15 # # Make sure we are not colliding with any existing files. # cleanup # # Link the DVI input file to standard input (the file to print). # ln -s /dev/fd/0 hpdf$$.dvi || fatal "Cannot symlink /dev/fd/0" # # Make LF = CR+LF # printf "\033&k2G" || fatal "Cannot initialize printer" # # Convert and print. Return value from dvilj2p does not seem to be # reliable, so we ignore it. # dvilj2p -M1 -q -e- dfhp$$.dvi # # Clean up and exit # cleanup exit 0 Automated Conversion: an Alternative to Conversion Filters All these conversion filters accomplish a lot for your printing environment, but at the cost forcing the user to specify (on the &man.lpr.1; command line) which one to use. If your users are not particularly computer literate, having to specify a filter option will become annoying. What is worse, though, is that an incorrectly specified filter option may run a filter on the wrong type of file and cause your printer to spew out hundreds of sheets of paper. Rather than install conversion filters at all, you might want to try having the text filter (since it is the default filter) detect the type of file it has been asked to print and then automatically run the right conversion filter. Tools such as file can be of help here. Of course, it will be hard to determine the differences between some file types—and, of course, you can still provide conversion filters just for them. apsfilter printing filters apsfilter The FreeBSD Ports Collection has a text filter that performs automatic conversion called apsfilter. It can detect plain text, &postscript;, and DVI files, run the proper conversions, and print. Output Filters The LPD spooling system supports one other type of filter that we have not yet explored: an output filter. An output filter is intended for printing plain text only, like the text filter, but with many simplifications. If you are using an output filter but no text filter, then: LPD starts an output filter once for the entire job instead of once for each file in the job. LPD does not make any provision to identify the start or the end of files within the job for the output filter. LPD does not pass the user's login or host to the filter, so it is not intended to do accounting. In fact, it gets only two arguments: filter-name -wwidth -llength Where width is from the pw capability and length is from the pl capability for the printer in question. Do not be seduced by an output filter's simplicity. If you would like each file in a job to start on a different page an output filter will not work. Use a text filter (also known as an input filter); see section Installing the Text Filter. Furthermore, an output filter is actually more complex in that it has to examine the byte stream being sent to it for special flag characters and must send signals to itself on behalf of LPD. However, an output filter is necessary if you want header pages and need to send escape sequences or other initialization strings to be able to print the header page. (But it is also futile if you want to charge header pages to the requesting user's account, since LPD does not give any user or host information to the output filter.) On a single printer, LPD allows both an output filter and text or other filters. In such cases, LPD will start the output filter to print the header page (see section Header Pages) only. LPD then expects the output filter to stop itself by sending two bytes to the filter: ASCII 031 followed by ASCII 001. When an output filter sees these two bytes (031, 001), it should stop by sending SIGSTOP to itself. When LPD's done running other filters, it will restart the output filter by sending SIGCONT to it. If there is an output filter but no text filter and LPD is working on a plain text job, LPD uses the output filter to do the job. As stated before, the output filter will print each file of the job in sequence with no intervening form feeds or other paper advancement, and this is probably not what you want. In almost all cases, you need a text filter. The program lpf, which we introduced earlier as a text filter, can also run as an output filter. If you need a quick-and-dirty output filter but do not want to write the byte detection and signal sending code, try lpf. You can also wrap lpf in a shell script to handle any initialization codes the printer might require. <command>lpf</command>: a Text Filter The program /usr/libexec/lpr/lpf that comes with FreeBSD binary distribution is a text filter (input filter) that can indent output (job submitted with lpr -i), allow literal characters to pass (job submitted with lpr -l), adjust the printing position for backspaces and tabs in the job, and account for pages printed. It can also act like an output filter. lpf is suitable for many printing environments. And although it has no capability to send initialization sequences to a printer, it is easy to write a shell script to do the needed initialization and then execute lpf. page accounting accounting printer In order for lpf to do page accounting correctly, it needs correct values filled in for the pw and pl capabilities in the /etc/printcap file. It uses these values to determine how much text can fit on a page and how many pages were in a user's job. For more information on printer accounting, see Accounting for Printer Usage. Header Pages If you have lots of users, all of them using various printers, then you probably want to consider header pages as a necessary evil. banner pages header pages header pages Header pages, also known as banner or burst pages identify to whom jobs belong after they are printed. They are usually printed in large, bold letters, perhaps with decorative borders, so that in a stack of printouts they stand out from the real documents that comprise users' jobs. They enable users to locate their jobs quickly. The obvious drawback to a header page is that it is yet one more sheet that has to be printed for every job, their ephemeral usefulness lasting not more than a few minutes, ultimately finding themselves in a recycling bin or rubbish heap. (Note that header pages go with each job, not each file in a job, so the paper waste might not be that bad.) The LPD system can provide header pages automatically for your printouts if your printer can directly print plain text. If you have a &postscript; printer, you will need an external program to generate the header page; see Header Pages on &postscript; Printers. Enabling Header Pages In the Simple Printer Setup section, we turned off header pages by specifying sh (meaning suppress header) in the /etc/printcap file. To enable header pages for a printer, just remove the sh capability. Sounds too easy, right? You are right. You might have to provide an output filter to send initialization strings to the printer. Here is an example output filter for Hewlett Packard PCL-compatible printers: #!/bin/sh # # hpof - Output filter for Hewlett Packard PCL-compatible printers # Installed in /usr/local/libexec/hpof printf "\033&k2G" || exit 2 exec /usr/libexec/lpr/lpf Specify the path to the output filter in the of capability. See the Output Filters section for more information. Here is an example /etc/printcap file for the printer teak that we introduced earlier; we enabled header pages and added the above output filter: # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif:\ :vf=/usr/local/libexec/hpvf:\ :of=/usr/local/libexec/hpof: Now, when users print jobs to teak, they get a header page with each job. If users want to spend time searching for their printouts, they can suppress header pages by submitting the job with lpr -h; see the Header Page Options section for more &man.lpr.1; options. LPD prints a form feed character after the header page. If your printer uses a different character or sequence of characters to eject a page, specify them with the ff capability in /etc/printcap. Controlling Header Pages By enabling header pages, LPD will produce a long header, a full page of large letters identifying the user, host, and job. Here is an example (kelly printed the job named outline from host rose): k ll ll k l l k l l k k eeee l l y y k k e e l l y y k k eeeeee l l y y kk k e l l y y k k e e l l y yy k k eeee lll lll yyy y y y y yyyy ll t l i t l oooo u u ttttt l ii n nnn eeee o o u u t l i nn n e e o o u u t l i n n eeeeee o o u u t l i n n e o o u uu t t l i n n e e oooo uuu u tt lll iii n n eeee r rrr oooo ssss eeee rr r o o s s e e r o o ss eeeeee r o o ss e r o o s s e e r oooo ssss eeee Job: outline Date: Sun Sep 17 11:04:58 1995 LPD appends a form feed after this text so the job starts on a new page (unless you have sf (suppress form feeds) in the destination printer's entry in /etc/printcap). If you prefer, LPD can make a short header; specify sb (short banner) in the /etc/printcap file. The header page will look like this: rose:kelly Job: outline Date: Sun Sep 17 11:07:51 1995 Also by default, LPD prints the header page first, then the job. To reverse that, specify hl (header last) in /etc/printcap. Accounting for Header Pages Using LPD's built-in header pages enforces a particular paradigm when it comes to printer accounting: header pages must be free of charge. Why? Because the output filter is the only external program that will have control when the header page is printed that could do accounting, and it is not provided with any user or host information or an accounting file, so it has no idea whom to charge for printer use. It is also not enough to just add one page to the text filter or any of the conversion filters (which do have user and host information) since users can suppress header pages with lpr -h. They could still be charged for header pages they did not print. Basically, lpr -h will be the preferred option of environmentally-minded users, but you cannot offer any incentive to use it. It is still not enough to have each of the filters generate their own header pages (thereby being able to charge for them). If users wanted the option of suppressing the header pages with lpr -h, they will still get them and be charged for them since LPD does not pass any knowledge of the option to any of the filters. So, what are your options? You can: Accept LPD's paradigm and make header pages free. Install an alternative to LPD, such as LPRng. Section Alternatives to the Standard Spooler tells more about other spooling software you can substitute for LPD. Write a smart output filter. Normally, an output filter is not meant to do anything more than initialize a printer or do some simple character conversion. It is suited for header pages and plain text jobs (when there is no text (input) filter). But, if there is a text filter for the plain text jobs, then LPD will start the output filter only for the header pages. And the output filter can parse the header page text that LPD generates to determine what user and host to charge for the header page. The only other problem with this method is that the output filter still does not know what accounting file to use (it is not passed the name of the file from the af capability), but if you have a well-known accounting file, you can hard-code that into the output filter. To facilitate the parsing step, use the sh (short header) capability in /etc/printcap. Then again, all that might be too much trouble, and users will certainly appreciate the more generous system administrator who makes header pages free. Header Pages on &postscript; Printers As described above, LPD can generate a plain text header page suitable for many printers. Of course, &postscript; cannot directly print plain text, so the header page feature of LPD is useless—or mostly so. One obvious way to get header pages is to have every conversion filter and the text filter generate the header page. The filters should use the user and host arguments to generate a suitable header page. The drawback of this method is that users will always get a header page, even if they submit jobs with lpr -h. Let us explore this method. The following script takes three arguments (user login name, host name, and job name) and makes a simple &postscript; header page: #!/bin/sh # # make-ps-header - make a PostScript header page on stdout # Installed in /usr/local/libexec/make-ps-header # # # These are PostScript units (72 to the inch). Modify for A4 or # whatever size paper you are using: # page_width=612 page_height=792 border=72 # # Check arguments # if [ $# -ne 3 ]; then echo "Usage: `basename $0` <user> <host> <job>" 1>&2 exit 1 fi # # Save these, mostly for readability in the PostScript, below. # user=$1 host=$2 job=$3 date=`date` # # Send the PostScript code to stdout. # exec cat <<EOF %!PS % % Make sure we do not interfere with user's job that will follow % save % % Make a thick, unpleasant border around the edge of the paper. % $border $border moveto $page_width $border 2 mul sub 0 rlineto 0 $page_height $border 2 mul sub rlineto currentscreen 3 -1 roll pop 100 3 1 roll setscreen $border 2 mul $page_width sub 0 rlineto closepath 0.8 setgray 10 setlinewidth stroke 0 setgray % % Display user's login name, nice and large and prominent % /Helvetica-Bold findfont 64 scalefont setfont $page_width ($user) stringwidth pop sub 2 div $page_height 200 sub moveto ($user) show % % Now show the boring particulars % /Helvetica findfont 14 scalefont setfont /y 200 def [ (Job:) (Host:) (Date:) ] { 200 y moveto show /y y 18 sub def } forall /Helvetica-Bold findfont 14 scalefont setfont /y 200 def [ ($job) ($host) ($date) ] { 270 y moveto show /y y 18 sub def } forall % % That is it % restore showpage EOF Now, each of the conversion filters and the text filter can call this script to first generate the header page, and then print the user's job. Here is the DVI conversion filter from earlier in this document, modified to make a header page: #!/bin/sh # # psdf - DVI to PostScript printer filter # Installed in /usr/local/libexec/psdf # # Invoked by lpd when user runs lpr -d # orig_args="$@" fail() { echo "$@" 1>&2 exit 2 } while getopts "x:y:n:h:" option; do case $option in x|y) ;; # Ignore n) login=$OPTARG ;; h) host=$OPTARG ;; *) echo "LPD started `basename $0` wrong." 1>&2 exit 2 ;; esac done [ "$login" ] || fail "No login name" [ "$host" ] || fail "No host name" ( /usr/local/libexec/make-ps-header $login $host "DVI File" /usr/local/bin/dvips -f ) | eval /usr/local/libexec/lprps $orig_args Notice how the filter has to parse the argument list in order to determine the user and host name. The parsing for the other conversion filters is identical. The text filter takes a slightly different set of arguments, though (see section How Filters Work). As we have mentioned before, the above scheme, though fairly simple, disables the suppress header page option (the option) to lpr. If users wanted to save a tree (or a few pennies, if you charge for header pages), they would not be able to do so, since every filter's going to print a header page with every job. To allow users to shut off header pages on a per-job basis, you will need to use the trick introduced in section Accounting for Header Pages: write an output filter that parses the LPD-generated header page and produces a &postscript; version. If the user submits the job with lpr -h, then LPD will not generate a header page, and neither will your output filter. Otherwise, your output filter will read the text from LPD and send the appropriate header page &postscript; code to the printer. If you have a &postscript; printer on a serial line, you can make use of lprps, which comes with an output filter, psof, which does the above. Note that psof does not charge for header pages. Networked Printing printers network network printing FreeBSD supports networked printing: sending jobs to remote printers. Networked printing generally refers to two different things: Accessing a printer attached to a remote host. You install a printer that has a conventional serial or parallel interface on one host. Then, you set up LPD to enable access to the printer from other hosts on the network. Section Printers Installed on Remote Hosts tells how to do this. Accessing a printer attached directly to a network. The printer has a network interface in addition (or in place of) a more conventional serial or parallel interface. Such a printer might work as follows: It might understand the LPD protocol and can even queue jobs from remote hosts. In this case, it acts just like a regular host running LPD. Follow the same procedure in section Printers Installed on Remote Hosts to set up such a printer. It might support a data stream network connection. In this case, you attach the printer to one host on the network by making that host responsible for spooling jobs and sending them to the printer. Section Printers with Networked Data Stream Interfaces gives some suggestions on installing such printers. Printers Installed on Remote Hosts The LPD spooling system has built-in support for sending jobs to other hosts also running LPD (or are compatible with LPD). This feature enables you to install a printer on one host and make it accessible from other hosts. It also works with printers that have network interfaces that understand the LPD protocol. To enable this kind of remote printing, first install a printer on one host, the printer host, using the simple printer setup described in the Simple Printer Setup section. Do any advanced setup in Advanced Printer Setup that you need. Make sure to test the printer and see if it works with the features of LPD you have enabled. Also ensure that the local host has authorization to use the LPD service in the remote host (see Restricting Jobs from Remote Printers). printers network network printing If you are using a printer with a network interface that is compatible with LPD, then the printer host in the discussion below is the printer itself, and the printer name is the name you configured for the printer. See the documentation that accompanied your printer and/or printer-network interface. If you are using a Hewlett Packard Laserjet then the printer name text will automatically perform the LF to CRLF conversion for you, so you will not require the hpif script. Then, on the other hosts you want to have access to the printer, make an entry in their /etc/printcap files with the following: Name the entry anything you want. For simplicity, though, you probably want to use the same name and aliases as on the printer host. Leave the lp capability blank, explicitly (:lp=:). Make a spooling directory and specify its location in the sd capability. LPD will store jobs here before they get sent to the printer host. Place the name of the printer host in the rm capability. Place the printer name on the printer host in the rp capability. That is it. You do not need to list conversion filters, page dimensions, or anything else in the /etc/printcap file. Here is an example. The host rose has two printers, bamboo and rattan. We will enable users on the host orchid to print to those printers. Here is the /etc/printcap file for orchid (back from section Enabling Header Pages). It already had the entry for the printer teak; we have added entries for the two printers on the host rose: # # /etc/printcap for host orchid - added (remote) printers on rose # # # teak is local; it is connected directly to orchid: # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/ifhp:\ :vf=/usr/local/libexec/vfhp:\ :of=/usr/local/libexec/ofhp: # # rattan is connected to rose; send jobs for rattan to rose: # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: # # bamboo is connected to rose as well: # bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo: Then, we just need to make spooling directories on orchid: &prompt.root; mkdir -p /var/spool/lpd/rattan /var/spool/lpd/bamboo &prompt.root; chmod 770 /var/spool/lpd/rattan /var/spool/lpd/bamboo &prompt.root; chown daemon:daemon /var/spool/lpd/rattan /var/spool/lpd/bamboo Now, users on orchid can print to rattan and bamboo. If, for example, a user on orchid typed &prompt.user; lpr -P bamboo -d sushi-review.dvi the LPD system on orchid would copy the job to the spooling directory /var/spool/lpd/bamboo and note that it was a DVI job. As soon as the host rose has room in its bamboo spooling directory, the two LPDs would transfer the file to rose. The file would wait in rose's queue until it was finally printed. It would be converted from DVI to &postscript; (since bamboo is a &postscript; printer) on rose. Printers with Networked Data Stream Interfaces Often, when you buy a network interface card for a printer, you can get two versions: one which emulates a spooler (the more expensive version), or one which just lets you send data to it as if you were using a serial or parallel port (the cheaper version). This section tells how to use the cheaper version. For the more expensive one, see the previous section Printers Installed on Remote Hosts. The format of the /etc/printcap file lets you specify what serial or parallel interface to use, and (if you are using a serial interface), what baud rate, whether to use flow control, delays for tabs, conversion of newlines, and more. But there is no way to specify a connection to a printer that is listening on a TCP/IP or other network port. To send data to a networked printer, you need to develop a communications program that can be called by the text and conversion filters. Here is one such example: the script netprint takes all data on standard input and sends it to a network-attached printer. We specify the hostname of the printer as the first argument and the port number to which to connect as the second argument to netprint. Note that this supports one-way communication only (FreeBSD to printer); many network printers support two-way communication, and you might want to take advantage of that (to get printer status, perform accounting, etc.). #!/usr/bin/perl # # netprint - Text filter for printer attached to network # Installed in /usr/local/libexec/netprint # $#ARGV eq 1 || die "Usage: $0 <printer-hostname> <port-number>"; $printer_host = $ARGV[0]; $printer_port = $ARGV[1]; require 'sys/socket.ph'; ($ignore, $ignore, $protocol) = getprotobyname('tcp'); ($ignore, $ignore, $ignore, $ignore, $address) = gethostbyname($printer_host); $sockaddr = pack('S n a4 x8', &AF_INET, $printer_port, $address); socket(PRINTER, &PF_INET, &SOCK_STREAM, $protocol) || die "Can't create TCP/IP stream socket: $!"; connect(PRINTER, $sockaddr) || die "Can't contact $printer_host: $!"; while (<STDIN>) { print PRINTER; } exit 0; We can then use this script in various filters. Suppose we had a Diablo 750-N line printer connected to the network. The printer accepts data to print on port number 5100. The host name of the printer is scrivener. Here is the text filter for the printer: #!/bin/sh # # diablo-if-net - Text filter for Diablo printer `scrivener' listening # on port 5100. Installed in /usr/local/libexec/diablo-if-net # exec /usr/libexec/lpr/lpf "$@" | /usr/local/libexec/netprint scrivener 5100 Restricting Printer Usage printers restricting access to This section gives information on restricting printer usage. The LPD system lets you control who can access a printer, both locally or remotely, whether they can print multiple copies, how large their jobs can be, and how large the printer queues can get. Restricting Multiple Copies The LPD system makes it easy for users to print multiple copies of a file. Users can print jobs with lpr -#5 (for example) and get five copies of each file in the job. Whether this is a good thing is up to you. If you feel multiple copies cause unnecessary wear and tear on your printers, you can disable the option to &man.lpr.1; by adding the sc capability to the /etc/printcap file. When users submit jobs with the option, they will see: lpr: multiple copies are not allowed Note that if you have set up access to a printer remotely (see section Printers Installed on Remote Hosts), you need the sc capability on the remote /etc/printcap files as well, or else users will still be able to submit multiple-copy jobs by using another host. Here is an example. This is the /etc/printcap file for the host rose. The printer rattan is quite hearty, so we will allow multiple copies, but the laser printer bamboo is a bit more delicate, so we will disable multiple copies by adding the sc capability: # # /etc/printcap for host rose - restrict multiple copies on bamboo # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:sc:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:rw:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: Now, we also need to add the sc capability on the host orchid's /etc/printcap (and while we are at it, let us disable multiple copies for the printer teak): # # /etc/printcap for host orchid - no multiple copies for local # printer teak or remote printer bamboo teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sd=/var/spool/lpd/teak:mx#0:sc:\ :if=/usr/local/libexec/ifhp:\ :vf=/usr/local/libexec/vfhp:\ :of=/usr/local/libexec/ofhp: rattan|line|diablo|lp|Diablo 630 Line Printer:\ :lp=:rm=rose:rp=rattan:sd=/var/spool/lpd/rattan: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :lp=:rm=rose:rp=bamboo:sd=/var/spool/lpd/bamboo:sc: By using the sc capability, we prevent the use of lpr -#, but that still does not prevent users from running &man.lpr.1; multiple times, or from submitting the same file multiple times in one job like this: &prompt.user; lpr forsale.sign forsale.sign forsale.sign forsale.sign forsale.sign There are many ways to prevent this abuse (including ignoring it) which you are free to explore. Restricting Access to Printers You can control who can print to what printers by using the &unix; group mechanism and the rg capability in /etc/printcap. Just place the users you want to have access to a printer in a certain group, and then name that group in the rg capability. Users outside the group (including root) will be greeted with lpr: Not a member of the restricted group if they try to print to the controlled printer. As with the sc (suppress multiple copies) capability, you need to specify rg on remote hosts that also have access to your printers, if you feel it is appropriate (see section Printers Installed on Remote Hosts). For example, we will let anyone access the printer rattan, but only those in group artists can use bamboo. Here is the familiar /etc/printcap for host rose: # # /etc/printcap for host rose - restricted group for bamboo # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:rw:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: Let us leave the other example /etc/printcap file (for the host orchid) alone. Of course, anyone on orchid can print to bamboo. It might be the case that we only allow certain logins on orchid anyway, and want them to have access to the printer. Or not. There can be only one restricted group per printer. Controlling Sizes of Jobs Submitted print jobs If you have many users accessing the printers, you probably need to put an upper limit on the sizes of the files users can submit to print. After all, there is only so much free space on the filesystem that houses the spooling directories, and you also need to make sure there is room for the jobs of other users. print jobs controlling LPD enables you to limit the maximum byte size a file in a job can be with the mx capability. The units are in BUFSIZ blocks, which are 1024 bytes. If you put a zero for this capability, there will be no limit on file size; however, if no mx capability is specified, then a default limit of 1000 blocks will be used. The limit applies to files in a job, and not the total job size. LPD will not refuse a file that is larger than the limit you place on a printer. Instead, it will queue as much of the file up to the limit, which will then get printed. The rest will be discarded. Whether this is correct behavior is up for debate. Let us add limits to our example printers rattan and bamboo. Since those artists' &postscript; files tend to be large, we will limit them to five megabytes. We will put no limit on the plain text line printer: # # /etc/printcap for host rose # # # No limit on job size: # rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:mx#0:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple: # # Limit of five megabytes: # bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:rw:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: Again, the limits apply to the local users only. If you have set up access to your printers remotely, remote users will not get those limits. You will need to specify the mx capability in the remote /etc/printcap files as well. See section Printers Installed on Remote Hosts for more information on remote printing. There is another specialized way to limit job sizes from remote printers; see section Restricting Jobs from Remote Printers. Restricting Jobs from Remote Printers The LPD spooling system provides several ways to restrict print jobs submitted from remote hosts: Host restrictions You can control from which remote hosts a local LPD accepts requests with the files /etc/hosts.equiv and /etc/hosts.lpd. LPD checks to see if an incoming request is from a host listed in either one of these files. If not, LPD refuses the request. The format of these files is simple: one host name per line. Note that the file /etc/hosts.equiv is also used by the &man.ruserok.3; protocol, and affects programs like &man.rsh.1; and &man.rcp.1;, so be careful. For example, here is the /etc/hosts.lpd file on the host rose: orchid violet madrigal.fishbaum.de This means rose will accept requests from the hosts orchid, violet, and madrigal.fishbaum.de. If any other host tries to access rose's LPD, the job will be refused. Size restrictions You can control how much free space there needs to remain on the filesystem where a spooling directory resides. Make a file called minfree in the spooling directory for the local printer. Insert in that file a number representing how many disk blocks (512 bytes) of free space there has to be for a remote job to be accepted. This lets you insure that remote users will not fill your filesystem. You can also use it to give a certain priority to local users: they will be able to queue jobs long after the free disk space has fallen below the amount specified in the minfree file. For example, let us add a minfree file for the printer bamboo. We examine /etc/printcap to find the spooling directory for this printer; here is bamboo's entry: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:sc:rg=artists:mx#5000:\ :lp=/dev/ttyd5:ms#-parenb cs8 clocal crtscts:rw:mx#5000:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: The spooling directory is given in the sd capability. We will make three megabytes (which is 6144 disk blocks) the amount of free disk space that must exist on the filesystem for LPD to accept remote jobs: &prompt.root; echo 6144 > /var/spool/lpd/bamboo/minfree User restrictions You can control which remote users can print to local printers by specifying the rs capability in /etc/printcap. When rs appears in the entry for a locally-attached printer, LPD will accept jobs from remote hosts if the user submitting the job also has an account of the same login name on the local host. Otherwise, LPD refuses the job. This capability is particularly useful in an environment where there are (for example) different departments sharing a network, and some users transcend departmental boundaries. By giving them accounts on your systems, they can use your printers from their own departmental systems. If you would rather allow them to use only your printers and not your computer resources, you can give them token accounts, with no home directory and a useless shell like /usr/bin/false. Accounting for Printer Usage accounting printer So, you need to charge for printouts. And why not? Paper and ink cost money. And then there are maintenance costs—printers are loaded with moving parts and tend to break down. You have examined your printers, usage patterns, and maintenance fees and have come up with a per-page (or per-foot, per-meter, or per-whatever) cost. Now, how do you actually start accounting for printouts? Well, the bad news is the LPD spooling system does not provide much help in this department. Accounting is highly dependent on the kind of printer in use, the formats being printed, and your requirements in charging for printer usage. To implement accounting, you have to modify a printer's text filter (to charge for plain text jobs) and the conversion filters (to charge for other file formats), to count pages or query the printer for pages printed. You cannot get away with using the simple output filter, since it cannot do accounting. See section Filters. Generally, there are two ways to do accounting: Periodic accounting is the more common way, possibly because it is easier. Whenever someone prints a job, the filter logs the user, host, and number of pages to an accounting file. Every month, semester, year, or whatever time period you prefer, you collect the accounting files for the various printers, tally up the pages printed by users, and charge for usage. Then you truncate all the logging files, starting with a clean slate for the next period. Timely accounting is less common, probably because it is more difficult. This method has the filters charge users for printouts as soon as they use the printers. Like disk quotas, the accounting is immediate. You can prevent users from printing when their account goes in the red, and might provide a way for users to check and adjust their print quotas. But this method requires some database code to track users and their quotas. The LPD spooling system supports both methods easily: since you have to provide the filters (well, most of the time), you also have to provide the accounting code. But there is a bright side: you have enormous flexibility in your accounting methods. For example, you choose whether to use periodic or timely accounting. You choose what information to log: user names, host names, job types, pages printed, square footage of paper used, how long the job took to print, and so forth. And you do so by modifying the filters to save this information. Quick and Dirty Printer Accounting FreeBSD comes with two programs that can get you set up with simple periodic accounting right away. They are the text filter lpf, described in section lpf: a Text Filter, and &man.pac.8;, a program to gather and total entries from printer accounting files. As mentioned in the section on filters (Filters), LPD starts the text and the conversion filters with the name of the accounting file to use on the filter command line. The filters can use this argument to know where to write an accounting file entry. The name of this file comes from the af capability in /etc/printcap, and if not specified as an absolute path, is relative to the spooling directory. LPD starts lpf with page width and length arguments (from the pw and pl capabilities). lpf uses these arguments to determine how much paper will be used. After sending the file to the printer, it then writes an accounting entry in the accounting file. The entries look like this: 2.00 rose:andy 3.00 rose:kelly 3.00 orchid:mary 5.00 orchid:mary 2.00 orchid:zhang You should use a separate accounting file for each printer, as lpf has no file locking logic built into it, and two lpfs might corrupt each other's entries if they were to write to the same file at the same time. An easy way to insure a separate accounting file for each printer is to use af=acct in /etc/printcap. Then, each accounting file will be in the spooling directory for a printer, in a file named acct. When you are ready to charge users for printouts, run the &man.pac.8; program. Just change to the spooling directory for the printer you want to collect on and type pac. You will get a dollar-centric summary like the following: Login pages/feet runs price orchid:kelly 5.00 1 $ 0.10 orchid:mary 31.00 3 $ 0.62 orchid:zhang 9.00 1 $ 0.18 rose:andy 2.00 1 $ 0.04 rose:kelly 177.00 104 $ 3.54 rose:mary 87.00 32 $ 1.74 rose:root 26.00 12 $ 0.52 total 337.00 154 $ 6.74 These are the arguments &man.pac.8; expects: Which printer to summarize. This option works only if there is an absolute path in the af capability in /etc/printcap. Sort the output by cost instead of alphabetically by user name. Ignore host name in the accounting files. With this option, user smith on host alpha is the same user smith on host gamma. Without, they are different users. Compute charges with price dollars per page or per foot instead of the price from the pc capability in /etc/printcap, or two cents (the default). You can specify price as a floating point number. Reverse the sort order. Make an accounting summary file and truncate the accounting file. name … Print accounting information for the given user names only. In the default summary that &man.pac.8; produces, you see the number of pages printed by each user from various hosts. If, at your site, host does not matter (because users can use any host), run pac -m, to produce the following summary: Login pages/feet runs price andy 2.00 1 $ 0.04 kelly 182.00 105 $ 3.64 mary 118.00 35 $ 2.36 root 26.00 12 $ 0.52 zhang 9.00 1 $ 0.18 total 337.00 154 $ 6.74 To compute the dollar amount due, &man.pac.8; uses the pc capability in the /etc/printcap file (default of 200, or 2 cents per page). Specify, in hundredths of cents, the price per page or per foot you want to charge for printouts in this capability. You can override this value when you run &man.pac.8; with the option. The units for the option are in dollars, though, not hundredths of cents. For example, &prompt.root; pac -p1.50 makes each page cost one dollar and fifty cents. You can really rake in the profits by using this option. Finally, running pac -s will save the summary information in a summary accounting file, which is named the same as the printer's accounting file, but with _sum appended to the name. It then truncates the accounting file. When you run &man.pac.8; again, it rereads the summary file to get starting totals, then adds information from the regular accounting file. How Can You Count Pages Printed? In order to perform even remotely accurate accounting, you need to be able to determine how much paper a job uses. This is the essential problem of printer accounting. For plain text jobs, the problem is not that hard to solve: you count how many lines are in a job and compare it to how many lines per page your printer supports. Do not forget to take into account backspaces in the file which overprint lines, or long logical lines that wrap onto one or more additional physical lines. The text filter lpf (introduced in lpf: a Text Filter) takes into account these things when it does accounting. If you are writing a text filter which needs to do accounting, you might want to examine lpf's source code. How do you handle other file formats, though? Well, for DVI-to-LaserJet or DVI-to-&postscript; conversion, you can have your filter parse the diagnostic output of dvilj or dvips and look to see how many pages were converted. You might be able to do similar things with other file formats and conversion programs. But these methods suffer from the fact that the printer may not actually print all those pages. For example, it could jam, run out of toner, or explode—and the user would still get charged. So, what can you do? There is only one sure way to do accurate accounting. Get a printer that can tell you how much paper it uses, and attach it via a serial line or a network connection. Nearly all &postscript; printers support this notion. Other makes and models do as well (networked Imagen laser printers, for example). Modify the filters for these printers to get the page usage after they print each job and have them log accounting information based on that value only. There is no line counting nor error-prone file examination required. Of course, you can always be generous and make all printouts free. Using Printers printers usage This section tells you how to use printers you have set up with FreeBSD. Here is an overview of the user-level commands: &man.lpr.1; Print jobs &man.lpq.1; Check printer queues &man.lprm.1; Remove jobs from a printer's queue There is also an administrative command, &man.lpc.8;, described in the section Administering the LPD Spooler, used to control printers and their queues. All three of the commands &man.lpr.1;, &man.lprm.1;, and &man.lpq.1; accept an option to specify on which printer/queue to operate, as listed in the /etc/printcap file. This enables you to submit, remove, and check on jobs for various printers. If you do not use the option, then these commands use the printer specified in the PRINTER environment variable. Finally, if you do not have a PRINTER environment variable, these commands default to the printer named lp. Hereafter, the terminology default printer means the printer named in the PRINTER environment variable, or the printer named lp when there is no PRINTER environment variable. Printing Jobs To print files, type: &prompt.user; lpr filename ... printing This prints each of the listed files to the default printer. If you list no files, &man.lpr.1; reads data to print from standard input. For example, this command prints some important system files: &prompt.user; lpr /etc/host.conf /etc/hosts.equiv To select a specific printer, type: &prompt.user; lpr -P printer-name filename ... This example prints a long listing of the current directory to the printer named rattan: &prompt.user; ls -l | lpr -P rattan Because no files were listed for the &man.lpr.1; command, lpr read the data to print from standard input, which was the output of the ls -l command. The &man.lpr.1; command can also accept a wide variety of options to control formatting, apply file conversions, generate multiple copies, and so forth. For more information, see the section Printing Options. Checking Jobs print jobs When you print with &man.lpr.1;, the data you wish to print is put together in a package called a print job, which is sent to the LPD spooling system. Each printer has a queue of jobs, and your job waits in that queue along with other jobs from yourself and from other users. The printer prints those jobs in a first-come, first-served order. To display the queue for the default printer, type &man.lpq.1;. For a specific printer, use the option. For example, the command &prompt.user; lpq -P bamboo shows the queue for the printer named bamboo. Here is an example of the output of the lpq command: bamboo is ready and printing Rank Owner Job Files Total Size active kelly 9 /etc/host.conf, /etc/hosts.equiv 88 bytes 2nd kelly 10 (standard input) 1635 bytes 3rd mary 11 ... 78519 bytes This shows three jobs in the queue for bamboo. The first job, submitted by user kelly, got assigned job number 9. Every job for a printer gets a unique job number. Most of the time you can ignore the job number, but you will need it if you want to cancel the job; see section Removing Jobs for details. Job number nine consists of two files; multiple files given on the &man.lpr.1; command line are treated as part of a single job. It is the currently active job (note the word active under the Rank column), which means the printer should be currently printing that job. The second job consists of data passed as the standard input to the &man.lpr.1; command. The third job came from user mary; it is a much larger job. The pathname of the file she is trying to print is too long to fit, so the &man.lpq.1; command just shows three dots. The very first line of the output from &man.lpq.1; is also useful: it tells what the printer is currently doing (or at least what LPD thinks the printer is doing). The &man.lpq.1; command also support a option to generate a detailed long listing. Here is an example of lpq -l: waiting for bamboo to become ready (offline ?) kelly: 1st [job 009rose] /etc/host.conf 73 bytes /etc/hosts.equiv 15 bytes kelly: 2nd [job 010rose] (standard input) 1635 bytes mary: 3rd [job 011rose] /home/orchid/mary/research/venus/alpha-regio/mapping 78519 bytes Removing Jobs If you change your mind about printing a job, you can remove the job from the queue with the &man.lprm.1; command. Often, you can even use &man.lprm.1; to remove an active job, but some or all of the job might still get printed. To remove a job from the default printer, first use &man.lpq.1; to find the job number. Then type: &prompt.user; lprm job-number To remove the job from a specific printer, add the option. The following command removes job number 10 from the queue for the printer bamboo: &prompt.user; lprm -P bamboo 10 The &man.lprm.1; command has a few shortcuts: lprm - Removes all jobs (for the default printer) belonging to you. lprm user Removes all jobs (for the default printer) belonging to user. The superuser can remove other users' jobs; you can remove only your own jobs. lprm With no job number, user name, or appearing on the command line, &man.lprm.1; removes the currently active job on the default printer, if it belongs to you. The superuser can remove any active job. Just use the option with the above shortcuts to operate on a specific printer instead of the default. For example, the following command removes all jobs for the current user in the queue for the printer named rattan: &prompt.user; lprm -P rattan - If you are working in a networked environment, &man.lprm.1; will let you remove jobs only from the host from which the jobs were submitted, even if the same printer is available from other hosts. The following command sequence demonstrates this: &prompt.user; lpr -P rattan myfile &prompt.user; rlogin orchid &prompt.user; lpq -P rattan Rank Owner Job Files Total Size active seeyan 12 ... 49123 bytes 2nd kelly 13 myfile 12 bytes &prompt.user; lprm -P rattan 13 rose: Permission denied &prompt.user; logout &prompt.user; lprm -P rattan 13 dfA013rose dequeued cfA013rose dequeued Beyond Plain Text: Printing Options The &man.lpr.1; command supports a number of options that control formatting text, converting graphic and other file formats, producing multiple copies, handling of the job, and more. This section describes the options. Formatting and Conversion Options The following &man.lpr.1; options control formatting of the files in the job. Use these options if the job does not contain plain text or if you want plain text formatted through the &man.pr.1; utility. &tex; For example, the following command prints a DVI file (from the &tex; typesetting system) named fish-report.dvi to the printer named bamboo: &prompt.user; lpr -P bamboo -d fish-report.dvi These options apply to every file in the job, so you cannot mix (say) DVI and ditroff files together in a job. Instead, submit the files as separate jobs, using a different conversion option for each job. All of these options except and require conversion filters installed for the destination printer. For example, the option requires the DVI conversion filter. Section Conversion Filters gives details. Print cifplot files. Print DVI files. Print FORTRAN text files. Print plot data. Indent the output by number columns; if you omit number, indent by 8 columns. This option works only with certain conversion filters. Do not put any space between the and the number. Print literal text data, including control characters. Print ditroff (device independent troff) data. -p Format plain text with &man.pr.1; before printing. See &man.pr.1; for more information. Use title on the &man.pr.1; header instead of the file name. This option has effect only when used with the option. Print troff data. Print raster data. Here is an example: this command prints a nicely formatted version of the &man.ls.1; manual page on the default printer: &prompt.user; zcat /usr/share/man/man1/ls.1.gz | troff -t -man | lpr -t The &man.zcat.1; command uncompresses the source of the &man.ls.1; manual page and passes it to the &man.troff.1; command, which formats that source and makes GNU troff output and passes it to &man.lpr.1;, which submits the job to the LPD spooler. Because we used the option to &man.lpr.1;, the spooler will convert the GNU troff output into a format the default printer can understand when it prints the job. Job Handling Options The following options to &man.lpr.1; tell LPD to handle the job specially: -# copies Produce a number of copies of each file in the job instead of just one copy. An administrator may disable this option to reduce printer wear-and-tear and encourage photocopier usage. See section Restricting Multiple Copies. This example prints three copies of parser.c followed by three copies of parser.h to the default printer: &prompt.user; lpr -#3 parser.c parser.h -m Send mail after completing the print job. With this option, the LPD system will send mail to your account when it finishes handling your job. In its message, it will tell you if the job completed successfully or if there was an error, and (often) what the error was. -s Do not copy the files to the spooling directory, but make symbolic links to them instead. If you are printing a large job, you probably want to use this option. It saves space in the spooling directory (your job might overflow the free space on the filesystem where the spooling directory resides). It saves time as well since LPD will not have to copy each and every byte of your job to the spooling directory. There is a drawback, though: since LPD will refer to the original files directly, you cannot modify or remove them until they have been printed. If you are printing to a remote printer, LPD will eventually have to copy files from the local host to the remote host, so the option will save space only on the local spooling directory, not the remote. It is still useful, though. -r Remove the files in the job after copying them to the spooling directory, or after printing them with the option. Be careful with this option! Header Page Options These options to &man.lpr.1; adjust the text that normally appears on a job's header page. If header pages are suppressed for the destination printer, these options have no effect. See section Header Pages for information about setting up header pages. -C text Replace the hostname on the header page with text. The hostname is normally the name of the host from which the job was submitted. -J text Replace the job name on the header page with text. The job name is normally the name of the first file of the job, or stdin if you are printing standard input. -h Do not print any header page. At some sites, this option may have no effect due to the way header pages are generated. See Header Pages for details. Administering Printers As an administrator for your printers, you have had to install, set up, and test them. Using the &man.lpc.8; command, you can interact with your printers in yet more ways. With &man.lpc.8;, you can Start and stop the printers Enable and disable their queues Rearrange the order of the jobs in each queue. First, a note about terminology: if a printer is stopped, it will not print anything in its queue. Users can still submit jobs, which will wait in the queue until the printer is started or the queue is cleared. If a queue is disabled, no user (except root) can submit jobs for the printer. An enabled queue allows jobs to be submitted. A printer can be started for a disabled queue, in which case it will continue to print jobs in the queue until the queue is empty. In general, you have to have root privileges to use the &man.lpc.8; command. Ordinary users can use the &man.lpc.8; command to get printer status and to restart a hung printer only. Here is a summary of the &man.lpc.8; commands. Most of the commands take a printer-name argument to tell on which printer to operate. You can use all for the printer-name to mean all printers listed in /etc/printcap. abort printer-name Cancel the current job and stop the printer. Users can still submit jobs if the queue is enabled. clean printer-name Remove old files from the printer's spooling directory. Occasionally, the files that make up a job are not properly removed by LPD, particularly if there have been errors during printing or a lot of administrative activity. This command finds files that do not belong in the spooling directory and removes them. disable printer-name Disable queuing of new jobs. If the printer is running, it will continue to print any jobs remaining in the queue. The superuser (root) can always submit jobs, even to a disabled queue. This command is useful while you are testing a new printer or filter installation: disable the queue and submit jobs as root. Other users will not be able to submit jobs until you complete your testing and re-enable the queue with the enable command. down printer-name message Take a printer down. Equivalent to disable followed by stop. The message appears as the printer's status whenever a user checks the printer's queue with &man.lpq.1; or status with lpc status. enable printer-name Enable the queue for a printer. Users can submit jobs but the printer will not print anything until it is started. help command-name Print help on the command command-name. With no command-name, print a summary of the commands available. restart printer-name Start the printer. Ordinary users can use this command if some extraordinary circumstance hangs LPD, but they cannot start a printer stopped with either the stop or down commands. The restart command is equivalent to abort followed by start. start printer-name Start the printer. The printer will print jobs in its queue. stop printer-name Stop the printer. The printer will finish the current job and will not print anything else in its queue. Even though the printer is stopped, users can still submit jobs to an enabled queue. topq printer-name job-or-username Rearrange the queue for printer-name by placing the jobs with the listed job numbers or the jobs belonging to username at the top of the queue. For this command, you cannot use all as the printer-name. up printer-name Bring a printer up; the opposite of the down command. Equivalent to start followed by enable. &man.lpc.8; accepts the above commands on the command line. If you do not enter any commands, &man.lpc.8; enters an interactive mode, where you can enter commands until you type exit, quit, or end-of-file. Alternatives to the Standard Spooler If you have been reading straight through this manual, by now you have learned just about everything there is to know about the LPD spooling system that comes with FreeBSD. You can probably appreciate many of its shortcomings, which naturally leads to the question: What other spooling systems are out there (and work with FreeBSD)? LPRng LPRng LPRng, which purportedly means LPR: the Next Generation is a complete rewrite of PLP. Patrick Powell and Justin Mason (the principal maintainer of PLP) collaborated to make LPRng. The main site for LPRng is . CUPS CUPS CUPS, the Common UNIX Printing System, provides a portable printing layer for &unix;-based operating systems. It has been developed by Easy Software Products to promote a standard printing solution for all &unix; vendors and users. CUPS uses the Internet Printing Protocol (IPP) as the basis for managing print jobs and queues. The Line Printer Daemon (LPD) Server Message Block (SMB), and AppSocket (a.k.a. JetDirect) protocols are also supported with reduced functionality. CUPS adds network printer browsing and PostScript Printer Description (PPD) based printing options to support real-world printing under &unix;. The main site for CUPS is . Troubleshooting After performing the simple test with &man.lptest.1;, you might have gotten one of the following results instead of the correct printout: It worked, after awhile; or, it did not eject a full sheet. The printer printed the above, but it sat for awhile and did nothing. In fact, you might have needed to press a PRINT REMAINING or FORM FEED button on the printer to get any results to appear. If this is the case, the printer was probably waiting to see if there was any more data for your job before it printed anything. To fix this problem, you can have the text filter send a FORM FEED character (or whatever is necessary) to the printer. This is usually sufficient to have the printer immediately print any text remaining in its internal buffer. It is also useful to make sure each print job ends on a full sheet, so the next job does not start somewhere on the middle of the last page of the previous job. The following replacement for the shell script /usr/local/libexec/if-simple prints a form feed after it sends the job to the printer: #!/bin/sh # # if-simple - Simple text input filter for lpd # Installed in /usr/local/libexec/if-simple # # Simply copies stdin to stdout. Ignores all filter arguments. # Writes a form feed character (\f) after printing job. /bin/cat && printf "\f" && exit 0 exit 2 It produced the staircase effect. You got the following on paper: !"#$%&'()*+,-./01234 "#$%&'()*+,-./012345 #$%&'()*+,-./0123456 MS-DOS OS/2 ASCII You have become another victim of the staircase effect, caused by conflicting interpretations of what characters should indicate a new line. &unix; style operating systems use a single character: ASCII code 10, the line feed (LF). &ms-dos;, &os2;, and others uses a pair of characters, ASCII code 10 and ASCII code 13 (the carriage return or CR). Many printers use the &ms-dos; convention for representing new-lines. When you print with FreeBSD, your text used just the line feed character. The printer, upon seeing a line feed character, advanced the paper one line, but maintained the same horizontal position on the page for the next character to print. That is what the carriage return is for: to move the location of the next character to print to the left edge of the paper. Here is what FreeBSD wants your printer to do: Printer received CR Printer prints CR Printer received LF Printer prints CR + LF Here are some ways to achieve this: Use the printer's configuration switches or control panel to alter its interpretation of these characters. Check your printer's manual to find out how to do this. If you boot your system into other operating systems besides FreeBSD, you may have to reconfigure the printer to use a an interpretation for CR and LF characters that those other operating systems use. You might prefer one of the other solutions, below. Have FreeBSD's serial line driver automatically convert LF to CR+LF. Of course, this works with printers on serial ports only. To enable this feature, use the ms# capability and set the onlcr mode in the /etc/printcap file for the printer. Send an escape code to the printer to have it temporarily treat LF characters differently. Consult your printer's manual for escape codes that your printer might support. When you find the proper escape code, modify the text filter to send the code first, then send the print job. PCL Here is an example text filter for printers that understand the Hewlett-Packard PCL escape codes. This filter makes the printer treat LF characters as a LF and CR; then it sends the job; then it sends a form feed to eject the last page of the job. It should work with nearly all Hewlett Packard printers. #!/bin/sh # # hpif - Simple text input filter for lpd for HP-PCL based printers # Installed in /usr/local/libexec/hpif # # Simply copies stdin to stdout. Ignores all filter arguments. # Tells printer to treat LF as CR+LF. Ejects the page when done. printf "\033&k2G" && cat && printf "\033&l0H" && exit 0 exit 2 Here is an example /etc/printcap from a host called orchid. It has a single printer attached to its first parallel port, a Hewlett Packard LaserJet 3Si named teak. It is using the above script as its text filter: # # /etc/printcap for host orchid # teak|hp|laserjet|Hewlett Packard LaserJet 3Si:\ :lp=/dev/lpt0:sh:sd=/var/spool/lpd/teak:mx#0:\ :if=/usr/local/libexec/hpif: It overprinted each line. The printer never advanced a line. All of the lines of text were printed on top of each other on one line. This problem is the opposite of the staircase effect, described above, and is much rarer. Somewhere, the LF characters that FreeBSD uses to end a line are being treated as CR characters to return the print location to the left edge of the paper, but not also down a line. Use the printer's configuration switches or control panel to enforce the following interpretation of LF and CR characters: Printer receives Printer prints CR CR LF CR + LF The printer lost characters. While printing, the printer did not print a few characters in each line. The problem might have gotten worse as the printer ran, losing more and more characters. The problem is that the printer cannot keep up with the speed at which the computer sends data over a serial line (this problem should not occur with printers on parallel ports). There are two ways to overcome the problem: If the printer supports XON/XOFF flow control, have FreeBSD use it by specifying the ixon mode in the ms# capability. If the printer supports carrier flow control, specify the crtscts mode in the ms# capability. Make sure the cable connecting the printer to the computer is correctly wired for carrier flow control. It printed garbage. The printer printed what appeared to be random garbage, but not the desired text. This is usually another symptom of incorrect communications parameters with a serial printer. Double-check the bps rate in the br capability, and the parity setting in the ms# capability; make sure the printer is using the same settings as specified in the /etc/printcap file. Nothing happened. If nothing happened, the problem is probably within FreeBSD and not the hardware. Add the log file (lf) capability to the entry for the printer you are debugging in the /etc/printcap file. For example, here is the entry for rattan, with the lf capability: rattan|line|diablo|lp|Diablo 630 Line Printer:\ :sh:sd=/var/spool/lpd/rattan:\ :lp=/dev/lpt0:\ :if=/usr/local/libexec/if-simple:\ :lf=/var/log/rattan.log Then, try printing again. Check the log file (in our example, /var/log/rattan.log) to see any error messages that might appear. Based on the messages you see, try to correct the problem. If you do not specify a lf capability, LPD uses /dev/console as a default. diff --git a/en_US.ISO8859-1/books/handbook/security/chapter.sgml b/en_US.ISO8859-1/books/handbook/security/chapter.sgml index 1f0119f045..dea91e8e61 100644 --- a/en_US.ISO8859-1/books/handbook/security/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/security/chapter.sgml @@ -1,7583 +1,7583 @@ Matthew Dillon Much of this chapter has been taken from the security(7) manual page by Security security Synopsis This chapter will provide a basic introduction to system security concepts, some general good rules of thumb, and some advanced topics under &os;. A lot of the topics covered here can be applied to system and Internet security in general as well. The Internet is no longer a friendly place in which everyone wants to be your kind neighbor. Securing your system is imperative to protect your data, intellectual property, time, and much more from the hands of hackers and the like. &os; provides an array of utilities and mechanisms to ensure the integrity and security of your system and network. After reading this chapter, you will know: Basic system security concepts, in respect to &os;. About the various crypt mechanisms available in &os;, such as DES and MD5. How to set up one-time password authentication. How to configure TCP Wrappers for use with inetd. How to set up KerberosIV on &os; releases prior to 5.0. How to set up Kerberos5 on post &os; 5.0 releases. How to create firewalls using IPFW. How to configure IPsec and create a VPN between &os;/&windows; machines. How to configure and use OpenSSH, &os;'s SSH implementation. What file system ACLs are and how to use them. How to utilize the &os; security advisories publications. Before reading this chapter, you should: Understand basic &os; and Internet concepts. Introduction Security is a function that begins and ends with the system administrator. While all BSD &unix; multi-user systems have some inherent security, the job of building and maintaining additional security mechanisms to keep those users honest is probably one of the single largest undertakings of the sysadmin. Machines are only as secure as you make them, and security concerns are ever competing with the human necessity for convenience. &unix; systems, in general, are capable of running a huge number of simultaneous processes and many of these processes operate as servers — meaning that external entities can connect and talk to them. As yesterday's mini-computers and mainframes become today's desktops, and as computers become networked and internetwork, security becomes an even bigger issue. Security is best implemented through a layered onion approach. In a nutshell, what you want to do is to create as many layers of security as are convenient and then carefully monitor the system for intrusions. You do not want to overbuild your security or you will interfere with the detection side, and detection is one of the single most important aspects of any security mechanism. For example, it makes little sense to set the schg flags (see &man.chflags.1;) on every system binary because while this may temporarily protect the binaries, it prevents an attacker who has broken in from making an easily detectable change that may result in your security mechanisms not detecting the attacker at all. System security also pertains to dealing with various forms of attack, including attacks that attempt to crash, or otherwise make a system unusable, but do not attempt to compromise the root account (break root). Security concerns can be split up into several categories: Denial of service attacks. User account compromises. Root compromise through accessible servers. Root compromise via user accounts. Backdoor creation. DoS attacks Denial of Service (DoS) security DoS attacks Denial of Service (DoS) Denial of Service (DoS) A denial of service attack is an action that deprives the machine of needed resources. Typically, DoS attacks are brute-force mechanisms that attempt to crash or otherwise make a machine unusable by overwhelming its servers or network stack. Some DoS attacks try to take advantage of bugs in the networking stack to crash a machine with a single packet. The latter can only be fixed by applying a bug fix to the kernel. Attacks on servers can often be fixed by properly specifying options to limit the load the servers incur on the system under adverse conditions. Brute-force network attacks are harder to deal with. A spoofed-packet attack, for example, is nearly impossible to stop, short of cutting your system off from the Internet. It may not be able to take your machine down, but it can saturate your Internet connection. security account compromises A user account compromise is even more common than a DoS attack. Many sysadmins still run standard telnetd, rlogind, rshd, and ftpd servers on their machines. These servers, by default, do not operate over encrypted connections. The result is that if you have any moderate-sized user base, one or more of your users logging into your system from a remote location (which is the most common and convenient way to login to a system) will have his or her password sniffed. The attentive system admin will analyze his remote access logs looking for suspicious source addresses even for successful logins. One must always assume that once an attacker has access to a user account, the attacker can break root. However, the reality is that in a well secured and maintained system, access to a user account does not necessarily give the attacker access to root. The distinction is important because without access to root the attacker cannot generally hide his tracks and may, at best, be able to do nothing more than mess with the user's files, or crash the machine. User account compromises are very common because users tend not to take the precautions that sysadmins take. security backdoors System administrators must keep in mind that there are potentially many ways to break root on a machine. The attacker may know the root password, the attacker may find a bug in a root-run server and be able to break root over a network connection to that server, or the attacker may know of a bug in a suid-root program that allows the attacker to break root once he has broken into a user's account. If an attacker has found a way to break root on a machine, the attacker may not have a need to install a backdoor. Many of the root holes found and closed to date involve a considerable amount of work by the attacker to cleanup after himself, so most attackers install backdoors. A backdoor provides the attacker with a way to easily regain root access to the system, but it also gives the smart system administrator a convenient way to detect the intrusion. Making it impossible for an attacker to install a backdoor may actually be detrimental to your security, because it will not close off the hole the attacker found to break in the first place. Security remedies should always be implemented with a multi-layered onion peel approach and can be categorized as follows: Securing root and staff accounts. Securing root–run servers and suid/sgid binaries. Securing user accounts. Securing the password file. Securing the kernel core, raw devices, and file systems. Quick detection of inappropriate changes made to the system. Paranoia. The next section of this chapter will cover the above bullet items in greater depth. Securing &os; security securing &os; Command vs. Protocol Throughout this document, we will use bold text to refer to an application, and a monospaced font to refer to specific commands. Protocols will use a normal font. This typographical distinction is useful for instances such as ssh, since it is a protocol as well as command. The sections that follow will cover the methods of securing your &os; system that were mentioned in the last section of this chapter. Securing the <username>root</username> Account and Staff Accounts su First off, do not bother securing staff accounts if you have not secured the root account. Most systems have a password assigned to the root account. The first thing you do is assume that the password is always compromised. This does not mean that you should remove the password. The password is almost always necessary for console access to the machine. What it does mean is that you should not make it possible to use the password outside of the console or possibly even with the &man.su.1; command. For example, make sure that your ptys are specified as being insecure in the /etc/ttys file so that direct root logins via telnet or rlogin are disallowed. If using other login services such as sshd, make sure that direct root logins are disabled there as well. You can do this by editing your /etc/ssh/sshd_config file, and making sure that PermitRootLogin is set to NO. Consider every access method — services such as FTP often fall through the cracks. Direct root logins should only be allowed via the system console. wheel Of course, as a sysadmin you have to be able to get to root, so we open up a few holes. But we make sure these holes require additional password verification to operate. One way to make root accessible is to add appropriate staff accounts to the wheel group (in /etc/group). The staff members placed in the wheel group are allowed to su to root. You should never give staff members native wheel access by putting them in the wheel group in their password entry. Staff accounts should be placed in a staff group, and then added to the wheel group via the /etc/group file. Only those staff members who actually need to have root access should be placed in the wheel group. It is also possible, when using an authentication method such as Kerberos, to use Kerberos' .k5login file in the root account to allow a &man.ksu.1; to root without having to place anyone at all in the wheel group. This may be the better solution since the wheel mechanism still allows an intruder to break root if the intruder has gotten hold of your password file and can break into a staff account. While having the wheel mechanism is better than having nothing at all, it is not necessarily the safest option. An indirect way to secure staff accounts, and ultimately root access is to use an alternative login access method and do what is known as starring out the encrypted password for the staff accounts. Using the &man.vipw.8; command, one can replace each instance of an encrypted password with a single * character. This command will update the /etc/master.passwd file and user/password database to disable password-authenticated logins. A staff account entry such as: foobar:R9DT/Fa1/LV9U:1000:1000::0:0:Foo Bar:/home/foobar:/usr/local/bin/tcsh Should be changed to this: foobar:*:1000:1000::0:0:Foo Bar:/home/foobar:/usr/local/bin/tcsh This change will prevent normal logins from occurring, since the encrypted password will never match *. With this done, staff members must use another mechanism to authenticate themselves such as &man.kerberos.1; or &man.ssh.1; using a public/private key pair. When using something like Kerberos, one generally must secure the machines which run the Kerberos servers and your desktop workstation. When using a public/private key pair with ssh, one must generally secure the machine used to login from (typically one's workstation). An additional layer of protection can be added to the key pair by password protecting the key pair when creating it with &man.ssh-keygen.1;. Being able to star out the passwords for staff accounts also guarantees that staff members can only login through secure access methods that you have set up. This forces all staff members to use secure, encrypted connections for all of their sessions, which closes an important hole used by many intruders: sniffing the network from an unrelated, less secure machine. The more indirect security mechanisms also assume that you are logging in from a more restrictive server to a less restrictive server. For example, if your main box is running all sorts of servers, your workstation should not be running any. In order for your workstation to be reasonably secure you should run as few servers as possible, up to and including no servers at all, and you should run a password-protected screen blanker. Of course, given physical access to a workstation an attacker can break any sort of security you put on it. This is definitely a problem that you should consider, but you should also consider the fact that the vast majority of break-ins occur remotely, over a network, from people who do not have physical access to your workstation or servers. KerberosIV Using something like Kerberos also gives you the ability to disable or change the password for a staff account in one place, and have it immediately affect all the machines on which the staff member may have an account. If a staff member's account gets compromised, the ability to instantly change his password on all machines should not be underrated. With discrete passwords, changing a password on N machines can be a mess. You can also impose re-passwording restrictions with Kerberos: not only can a Kerberos ticket be made to timeout after a while, but the Kerberos system can require that the user choose a new password after a certain period of time (say, once a month). Securing Root-run Servers and SUID/SGID Binaries ntalk comsat finger sandboxes sshd telnetd rshd rlogind The prudent sysadmin only runs the servers he needs to, no more, no less. Be aware that third party servers are often the most bug-prone. For example, running an old version of imapd or popper is like giving a universal root ticket out to the entire world. Never run a server that you have not checked out carefully. Many servers do not need to be run as root. For example, the ntalk, comsat, and finger daemons can be run in special user sandboxes. A sandbox is not perfect, unless you go through a large amount of trouble, but the onion approach to security still stands: If someone is able to break in through a server running in a sandbox, they still have to break out of the sandbox. The more layers the attacker must break through, the lower the likelihood of his success. Root holes have historically been found in virtually every server ever run as root, including basic system servers. If you are running a machine through which people only login via sshd and never login via telnetd or rshd or rlogind, then turn off those services! &os; now defaults to running ntalkd, comsat, and finger in a sandbox. Another program which may be a candidate for running in a sandbox is &man.named.8;. /etc/defaults/rc.conf includes the arguments necessary to run named in a sandbox in a commented-out form. Depending on whether you are installing a new system or upgrading an existing system, the special user accounts used by these sandboxes may not be installed. The prudent sysadmin would research and implement sandboxes for servers whenever possible. sendmail There are a number of other servers that typically do not run in sandboxes: sendmail, popper, imapd, ftpd, and others. There are alternatives to some of these, but installing them may require more work than you are willing to perform (the convenience factor strikes again). You may have to run these servers as root and rely on other mechanisms to detect break-ins that might occur through them. The other big potential root holes in a system are the suid-root and sgid binaries installed on the system. Most of these binaries, such as rlogin, reside in /bin, /sbin, /usr/bin, or /usr/sbin. While nothing is 100% safe, the system-default suid and sgid binaries can be considered reasonably safe. Still, root holes are occasionally found in these binaries. A root hole was found in Xlib in 1998 that made xterm (which is typically suid) vulnerable. It is better to be safe than sorry and the prudent sysadmin will restrict suid binaries, that only staff should run, to a special group that only staff can access, and get rid of (chmod 000) any suid binaries that nobody uses. A server with no display generally does not need an xterm binary. Sgid binaries can be almost as dangerous. If an intruder can break an sgid-kmem binary, the intruder might be able to read /dev/kmem and thus read the encrypted password file, potentially compromising any passworded account. Alternatively an intruder who breaks group kmem can monitor keystrokes sent through ptys, including Pt's used by users who login through secure methods. An intruder that breaks the tty group can write to almost any user's tty. If a user is running a terminal program or emulator with a keyboard-simulation feature, the intruder can potentially generate a data stream that causes the user's terminal to echo a command, which is then run as that user. Securing User Accounts User accounts are usually the most difficult to secure. While you can impose Draconian access restrictions on your staff and star out their passwords, you may not be able to do so with any general user accounts you might have. If you do have sufficient control, then you may win out and be able to secure the user accounts properly. If not, you simply have to be more vigilant in your monitoring of those accounts. Use of ssh and Kerberos for user accounts is more problematic, due to the extra administration and technical support required, but still a very good solution compared to a crypted password file. Securing the Password File The only sure fire way is to * out as many passwords as you can and use ssh or Kerberos for access to those accounts. Even though the encrypted password file (/etc/spwd.db) can only be read by root, it may be possible for an intruder to obtain read access to that file even if the attacker cannot obtain root-write access. Your security scripts should always check for and report changes to the password file (see the Checking file integrity section below). Securing the Kernel Core, Raw Devices, and File systems If an attacker breaks root he can do just about anything, but there are certain conveniences. For example, most modern kernels have a packet sniffing device driver built in. Under &os; it is called the bpf device. An intruder will commonly attempt to run a packet sniffer on a compromised machine. You do not need to give the intruder the capability and most systems do not have the need for the bpf device compiled in. sysctl But even if you turn off the bpf device, you still have /dev/mem and /dev/kmem to worry about. For that matter, the intruder can still write to raw disk devices. Also, there is another kernel feature called the module loader, &man.kldload.8;. An enterprising intruder can use a KLD module to install his own bpf device, or other sniffing device, on a running kernel. To avoid these problems you have to run the kernel at a higher secure level, at least securelevel 1. The securelevel can be set with a sysctl on the kern.securelevel variable. Once you have set the securelevel to 1, write access to raw devices will be denied and special chflags flags, such as schg, will be enforced. You must also ensure that the schg flag is set on critical startup binaries, directories, and script files — everything that gets run up to the point where the securelevel is set. This might be overdoing it, and upgrading the system is much more difficult when you operate at a higher secure level. You may compromise and run the system at a higher secure level but not set the schg flag for every system file and directory under the sun. Another possibility is to simply mount / and /usr read-only. It should be noted that being too Draconian in what you attempt to protect may prevent the all-important detection of an intrusion. Checking File Integrity: Binaries, Configuration Files, Etc. When it comes right down to it, you can only protect your core system configuration and control files so much before the convenience factor rears its ugly head. For example, using chflags to set the schg bit on most of the files in / and /usr is probably counterproductive, because while it may protect the files, it also closes a detection window. The last layer of your security onion is perhaps the most important — detection. The rest of your security is pretty much useless (or, worse, presents you with a false sense of safety) if you cannot detect potential incursions. Half the job of the onion is to slow down the attacker, rather than stop him, in order to give the detection side of the equation a chance to catch him in the act. The best way to detect an incursion is to look for modified, missing, or unexpected files. The best way to look for modified files is from another (often centralized) limited-access system. Writing your security scripts on the extra-secure limited-access system makes them mostly invisible to potential attackers, and this is important. In order to take maximum advantage you generally have to give the limited-access box significant access to the other machines in the business, usually either by doing a read-only NFS export of the other machines to the limited-access box, or by setting up ssh key-pairs to allow the limited-access box to ssh to the other machines. Except for its network traffic, NFS is the least visible method — allowing you to monitor the file systems on each client box virtually undetected. If your limited-access server is connected to the client boxes through a switch, the NFS method is often the better choice. If your limited-access server is connected to the client boxes through a hub, or through several layers of routing, the NFS method may be too insecure (network-wise) and using ssh may be the better choice even with the audit-trail tracks that ssh lays. Once you give a limited-access box, at least read access to the client systems it is supposed to monitor, you must write scripts to do the actual monitoring. Given an NFS mount, you can write scripts out of simple system utilities such as &man.find.1; and &man.md5.1;. It is best to physically md5 the client-box files at least once a day, and to test control files such as those found in /etc and /usr/local/etc even more often. When mismatches are found, relative to the base md5 information the limited-access machine knows is valid, it should scream at a sysadmin to go check it out. A good security script will also check for inappropriate suid binaries and for new or deleted files on system partitions such as / and /usr. When using ssh rather than NFS, writing the security script is much more difficult. You essentially have to scp the scripts to the client box in order to run them, making them visible, and for safety you also need to scp the binaries (such as find) that those scripts use. The ssh client on the client box may already be compromised. All in all, using ssh may be necessary when running over insecure links, but it is also a lot harder to deal with. A good security script will also check for changes to user and staff members access configuration files: .rhosts, .shosts, .ssh/authorized_keys and so forth… files that might fall outside the purview of the MD5 check. If you have a huge amount of user disk space, it may take too long to run through every file on those partitions. In this case, setting mount flags to disallow suid binaries and devices on those partitions is a good idea. The nodev and nosuid options (see &man.mount.8;) are what you want to look into. You should probably scan them anyway, at least once a week, since the object of this layer is to detect a break-in whether or not the break-in is effective. Process accounting (see &man.accton.8;) is a relatively low-overhead feature of the operating system which might help as a post-break-in evaluation mechanism. It is especially useful in tracking down how an intruder has actually broken into a system, assuming the file is still intact after the break-in occurs. Finally, security scripts should process the log files, and the logs themselves should be generated in as secure a manner as possible — remote syslog can be very useful. An intruder tries to cover his tracks, and log files are critical to the sysadmin trying to track down the time and method of the initial break-in. One way to keep a permanent record of the log files is to run the system console to a serial port and collect the information on a continuing basis through a secure machine monitoring the consoles. Paranoia A little paranoia never hurts. As a rule, a sysadmin can add any number of security features, as long as they do not affect convenience, and can add security features that do affect convenience with some added thought. Even more importantly, a security administrator should mix it up a bit — if you use recommendations such as those given by this document verbatim, you give away your methodologies to the prospective attacker who also has access to this document. Denial of Service Attacks Denial of Service (DoS) This section covers Denial of Service attacks. A DoS attack is typically a packet attack. While there is not much you can do about modern spoofed packet attacks that saturate your network, you can generally limit the damage by ensuring that the attacks cannot take down your servers. Limiting server forks. Limiting springboard attacks (ICMP response attacks, ping broadcast, etc.). Kernel Route Cache. A common DoS attack is against a forking server that attempts to cause the server to eat processes, file descriptors, and memory, until the machine dies. inetd (see &man.inetd.8;) has several options to limit this sort of attack. It should be noted that while it is possible to prevent a machine from going down, it is not generally possible to prevent a service from being disrupted by the attack. Read the inetd manual page carefully and pay specific attention to the , , and options. Note that spoofed-IP attacks will circumvent the option to inetd, so typically a combination of options must be used. Some standalone servers have self-fork-limitation parameters. Sendmail has its option, which tends to work much better than trying to use sendmail's load limiting options due to the load lag. You should specify a MaxDaemonChildren parameter, when you start sendmail, high enough to handle your expected load, but not so high that the computer cannot handle that number of sendmails without falling on its face. It is also prudent to run sendmail in queued mode () and to run the daemon (sendmail -bd) separate from the queue-runs (sendmail -q15m). If you still want real-time delivery you can run the queue at a much lower interval, such as , but be sure to specify a reasonable MaxDaemonChildren option for that sendmail to prevent cascade failures. Syslogd can be attacked directly and it is strongly recommended that you use the option whenever possible, and the option otherwise. You should also be fairly careful with connect-back services such as tcpwrapper's reverse-identd, which can be attacked directly. You generally do not want to use the reverse-ident feature of tcpwrappers for this reason. It is a very good idea to protect internal services from external access by firewalling them off at your border routers. The idea here is to prevent saturation attacks from outside your LAN, not so much to protect internal services from network-based root compromise. Always configure an exclusive firewall, i.e., firewall everything except ports A, B, C, D, and M-Z. This way you can firewall off all of your low ports except for certain specific services such as named (if you are primary for a zone), ntalkd, sendmail, and other Internet-accessible services. If you try to configure the firewall the other way — as an inclusive or permissive firewall, there is a good chance that you will forget to close a couple of services, or that you will add a new internal service and forget to update the firewall. You can still open up the high-numbered port range on the firewall, to allow permissive-like operation, without compromising your low ports. Also take note that &os; allows you to control the range of port numbers used for dynamic binding, via the various net.inet.ip.portrange sysctl's (sysctl -a | fgrep portrange), which can also ease the complexity of your firewall's configuration. For example, you might use a normal first/last range of 4000 to 5000, and a hiport range of 49152 to 65535, then block off everything under 4000 in your firewall (except for certain specific Internet-accessible ports, of course). ICMP_BANDLIM Another common DoS attack is called a springboard attack — to attack a server in a manner that causes the server to generate responses which overloads the server, the local network, or some other machine. The most common attack of this nature is the ICMP ping broadcast attack. The attacker spoofs ping packets sent to your LAN's broadcast address with the source IP address set to the actual machine they wish to attack. If your border routers are not configured to stomp on ping's to broadcast addresses, your LAN winds up generating sufficient responses to the spoofed source address to saturate the victim, especially when the attacker uses the same trick on several dozen broadcast addresses over several dozen different networks at once. Broadcast attacks of over a hundred and twenty megabits have been measured. A second common springboard attack is against the ICMP error reporting system. By constructing packets that generate ICMP error responses, an attacker can saturate a server's incoming network and cause the server to saturate its outgoing network with ICMP responses. This type of attack can also crash the server by running it out of mbuf's, especially if the server cannot drain the ICMP responses it generates fast enough. The &os; kernel has a new kernel compile option called which limits the effectiveness of these sorts of attacks. The last major class of springboard attacks is related to certain internal inetd services such as the udp echo service. An attacker simply spoofs a UDP packet with the source address being server A's echo port, and the destination address being server B's echo port, where server A and B are both on your LAN. The two servers then bounce this one packet back and forth between each other. The attacker can overload both servers and their LANs simply by injecting a few packets in this manner. Similar problems exist with the internal chargen port. A competent sysadmin will turn off all of these inetd-internal test services. Spoofed packet attacks may also be used to overload the kernel route cache. Refer to the net.inet.ip.rtexpire, rtminexpire, and rtmaxcache sysctl parameters. A spoofed packet attack that uses a random source IP will cause the kernel to generate a temporary cached route in the route table, viewable with netstat -rna | fgrep W3. These routes typically timeout in 1600 seconds or so. If the kernel detects that the cached route table has gotten too big it will dynamically reduce the rtexpire but will never decrease it to less than rtminexpire. There are two problems: The kernel does not react quickly enough when a lightly loaded server is suddenly attacked. The rtminexpire is not low enough for the kernel to survive a sustained attack. If your servers are connected to the Internet via a T3 or better, it may be prudent to manually override both rtexpire and rtminexpire via &man.sysctl.8;. Never set either parameter to zero (unless you want to crash the machine). Setting both parameters to 2 seconds should be sufficient to protect the route table from attack. Access Issues with Kerberos and SSH ssh KerberosIV There are a few issues with both Kerberos and ssh that need to be addressed if you intend to use them. Kerberos V is an excellent authentication protocol, but there are bugs in the kerberized telnet and rlogin applications that make them unsuitable for dealing with binary streams. Also, by default Kerberos does not encrypt a session unless you use the option. ssh encrypts everything by default. ssh works quite well in every respect except that it forwards encryption keys by default. What this means is that if you have a secure workstation holding keys that give you access to the rest of the system, and you ssh to an insecure machine, your keys are usable. The actual keys themselves are not exposed, but ssh installs a forwarding port for the duration of your login, and if an attacker has broken root on the insecure machine he can utilize that port to use your keys to gain access to any other machine that your keys unlock. We recommend that you use ssh in combination with Kerberos whenever possible for staff logins. ssh can be compiled with Kerberos support. This reduces your reliance on potentially exposed ssh keys while at the same time protecting passwords via Kerberos. ssh keys should only be used for automated tasks from secure machines (something that Kerberos is unsuited to do). We also recommend that you either turn off key-forwarding in the ssh configuration, or that you make use of the from=IP/DOMAIN option that ssh allows in its authorized_keys file to make the key only usable to entities logging in from specific machines. Bill Swingle Parts rewritten and updated by DES, MD5, and Crypt security crypt crypt DES MD5 Every user on a &unix; system has a password associated with their account. It seems obvious that these passwords need to be known only to the user and the actual operating system. In order to keep these passwords secret, they are encrypted with what is known as a one-way hash, that is, they can only be easily encrypted but not decrypted. In other words, what we told you a moment ago was obvious is not even true: the operating system itself does not really know the password. It only knows the encrypted form of the password. The only way to get the plain-text password is by a brute force search of the space of possible passwords. Unfortunately the only secure way to encrypt passwords when &unix; came into being was based on DES, the Data Encryption Standard. This was not such a problem for users resident in the US, but since the source code for DES could not be exported outside the US, &os; had to find a way to both comply with US law and retain compatibility with all the other &unix; variants that still used DES. The solution was to divide up the encryption libraries so that US users could install the DES libraries and use DES but international users still had an encryption method that could be exported abroad. This is how &os; came to use MD5 as its default encryption method. MD5 is believed to be more secure than DES, so installing DES is offered primarily for compatibility reasons. Recognizing Your Crypt Mechanism Before &os; 4.4 libcrypt.a was a symbolic link pointing to the library which was used for encryption. &os; 4.4 changed libcrypt.a to provide a configurable password authentication hash library. Currently the library supports DES, MD5 and Blowfish hash functions. By default &os; uses MD5 to encrypt passwords. It is pretty easy to identify which encryption method &os; is set up to use. Examining the encrypted passwords in the /etc/master.passwd file is one way. Passwords encrypted with the MD5 hash are longer than those encrypted with the DES hash and also begin with the characters $1$. Passwords starting with $2a$ are encrypted with the Blowfish hash function. DES password strings do not have any particular identifying characteristics, but they are shorter than MD5 passwords, and are coded in a 64-character alphabet which does not include the $ character, so a relatively short string which does not begin with a dollar sign is very likely a DES password. The password format used for new passwords is controlled by the passwd_format login capability in /etc/login.conf, which takes values of des, md5 or blf. See the &man.login.conf.5; manual page for more information about login capabilities. One-time Passwords one-time passwords security one-time passwords S/Key is a one-time password scheme based on a one-way hash function. &os; uses the MD4 hash for compatibility but other systems have used MD5 and DES-MAC. S/Key has been part of the &os; base system since version 1.1.5 and is also used on a growing number of other operating systems. S/Key is a registered trademark of Bell Communications Research, Inc. From version 5.0 of &os;, S/Key has been replaced with the functionally equivalent OPIE (One-time Passwords In Everything). OPIE uses the MD5 hash by default. There are three different sorts of passwords which we will discuss below. The first is your usual &unix; style or Kerberos password; we will call this a &unix; password. The second sort is the one-time password which is generated by the S/Key key program or the OPIE &man.opiekey.1; program and accepted by the keyinit or &man.opiepasswd.1; programs and the login prompt; we will call this a one-time password. The final sort of password is the secret password which you give to the key/opiekey programs (and sometimes the keyinit/opiepasswd programs) which it uses to generate one-time passwords; we will call it a secret password or just unqualified password. The secret password does not have anything to do with your &unix; password; they can be the same but this is not recommended. S/Key and OPIE secret passwords are not limited to 8 characters like old &unix; passwordsUnder &os; the standard login password may be up to 128 characters in length., they can be as long as you like. Passwords of six or seven word long phrases are fairly common. For the most part, the S/Key or OPIE system operates completely independently of the &unix; password system. Besides the password, there are two other pieces of data that are important to S/Key and OPIE. One is what is known as the seed or key, consisting of two letters and five digits. The other is what is called the iteration count, a number between 1 and 100. S/Key creates the one-time password by concatenating the seed and the secret password, then applying the MD4/MD5 hash as many times as specified by the iteration count and turning the result into six short English words. These six English words are your one-time password. The authentication system (primarily PAM) keeps track of the last one-time password used, and the user is authenticated if the hash of the user-provided password is equal to the previous password. Because a one-way hash is used it is impossible to generate future one-time passwords if a successfully used password is captured; the iteration count is decremented after each successful login to keep the user and the login program in sync. When the iteration count gets down to 1, S/Key and OPIE must be reinitialized. There are three programs involved in each system which we will discuss below. The key and opiekey programs accept an iteration count, a seed, and a secret password, and generate a one-time password or a consecutive list of one-time passwords. The keyinit and opiepasswd programs are used to initialize S/Key and OPIE respectively, and to change passwords, iteration counts, or seeds; they take either a secret passphrase, or an iteration count, seed, and one-time password. The keyinfo and opieinfo programs examine the relevant credentials files (/etc/skeykeys or /etc/opiekeys) and print out the invoking user's current iteration count and seed. There are four different sorts of operations we will cover. The first is using keyinit or opiepasswd over a secure connection to set up one-time-passwords for the first time, or to change your password or seed. The second operation is using keyinit or opiepasswd over an insecure connection, in conjunction with key or opiekey over a secure connection, to do the same. The third is using key/opiekey to log in over an insecure connection. The fourth is using key or opiekey to generate a number of keys which can be written down or printed out to carry with you when going to some location without secure connections to anywhere. Secure Connection Initialization To initialize S/Key for the first time, change your password, or change your seed while logged in over a secure connection (e.g. on the console of a machine or via ssh), use the keyinit command without any parameters while logged in as yourself: &prompt.user; keyinit Adding unfurl: Reminder - Only use this method if you are directly connected. If you are using telnet or rlogin exit with no password and use keyinit -s. Enter secret password: Again secret password: ID unfurl s/key is 99 to17757 DEFY CLUB PRO NASH LACE SOFT For OPIE, opiepasswd is used instead: &prompt.user; opiepasswd -c [grimreaper] ~ $ opiepasswd -f -c Adding unfurl: Only use this method from the console; NEVER from remote. If you are using telnet, xterm, or a dial-in, type ^C now or exit with no password. Then run opiepasswd without the -c parameter. Using MD5 to compute responses. Enter new secret pass phrase: Again new secret pass phrase: ID unfurl OTP key is 499 to4268 MOS MALL GOAT ARM AVID COED At the Enter new secret pass phrase: or Enter secret password: prompts, you should enter a password or phrase. Remember, this is not the password that you will use to login with, this is used to generate your one-time login keys. The ID line gives the parameters of your particular instance: your login name, the iteration count, and seed. When logging in the system will remember these parameters and present them back to you so you do not have to remember them. The last line gives the particular one-time password which corresponds to those parameters and your secret password; if you were to re-login immediately, this one-time password is the one you would use. Insecure Connection Initialization To initialize or change your secret password over an insecure connection, you will need to already have a secure connection to some place where you can run key or opiekey; this might be in the form of a desk accessory on a &macintosh;, or a shell prompt on a machine you trust. You will also need to make up an iteration count (100 is probably a good value), and you may make up your own seed or use a randomly-generated one. Over on the insecure connection (to the machine you are initializing), use the keyinit -s command: &prompt.user; keyinit -s Updating unfurl: Old key: to17758 Reminder you need the 6 English words from the key command. Enter sequence count from 1 to 9999: 100 Enter new key [default to17759]: s/key 100 to 17759 s/key access password: s/key access password:CURE MIKE BANE HIM RACY GORE For OPIE, you need to use opiepasswd: &prompt.user; opiepasswd Updating unfurl: You need the response from an OTP generator. Old secret pass phrase: otp-md5 498 to4268 ext Response: GAME GAG WELT OUT DOWN CHAT New secret pass phrase: otp-md5 499 to4269 Response: LINE PAP MILK NELL BUOY TROY ID mark OTP key is 499 gr4269 LINE PAP MILK NELL BUOY TROY To accept the default seed (which the keyinit program confusingly calls a key), press Return. Then before entering an access password, move over to your secure connection or S/Key desk accessory, and give it the same parameters: &prompt.user; key 100 to17759 Reminder - Do not use this program while logged in via telnet or rlogin. Enter secret password: <secret password> CURE MIKE BANE HIM RACY GORE Or for OPIE: &prompt.user; opiekey 498 to4268 Using the MD5 algorithm to compute response. Reminder: Don't use opiekey from telnet or dial-in sessions. Enter secret pass phrase: GAME GAG WELT OUT DOWN CHAT Now switch back over to the insecure connection, and copy the one-time password generated over to the relevant program. Generating a Single One-time Password Once you have initialized S/Key or OPIE, when you login you will be presented with a prompt like this: &prompt.user; telnet example.com Trying 10.0.0.1... Connected to example.com Escape character is '^]'. FreeBSD/i386 (example.com) (ttypa) login: <username> s/key 97 fw13894 Password: Or for OPIE: &prompt.user; telnet example.com Trying 10.0.0.1... Connected to example.com Escape character is '^]'. FreeBSD/i386 (example.com) (ttypa) login: <username> otp-md5 498 gr4269 ext Password: As a side note, the S/Key and OPIE prompts have a useful feature (not shown here): if you press Return at the password prompt, the prompter will turn echo on, so you can see what you are typing. This can be extremely useful if you are attempting to type in a password by hand, such as from a printout. MS-DOS Windows MacOS At this point you need to generate your one-time password to answer this login prompt. This must be done on a trusted system that you can run key or opiekey on. (There are versions of these for DOS, &windows; and &macos; as well.) They need both the iteration count and the seed as command line options. You can cut-and-paste these right from the login prompt on the machine that you are logging in to. On the trusted system: &prompt.user; key 97 fw13894 Reminder - Do not use this program while logged in via telnet or rlogin. Enter secret password: WELD LIP ACTS ENDS ME HAAG For OPIE: &prompt.user; opiekey 498 to4268 Using the MD5 algorithm to compute response. Reminder: Don't use opiekey from telnet or dial-in sessions. Enter secret pass phrase: GAME GAG WELT OUT DOWN CHAT Now that you have your one-time password you can continue logging in: login: <username> s/key 97 fw13894 Password: <return to enable echo> s/key 97 fw13894 Password [echo on]: WELD LIP ACTS ENDS ME HAAG Last login: Tue Mar 21 11:56:41 from 10.0.0.2 ... Generating Multiple One-time Passwords Sometimes you have to go places where you do not have access to a trusted machine or secure connection. In this case, it is possible to use the key and opiekey commands to generate a number of one-time passwords beforehand to be printed out and taken with you. For example: &prompt.user; key -n 5 30 zz99999 Reminder - Do not use this program while logged in via telnet or rlogin. Enter secret password: <secret password> 26: SODA RUDE LEA LIND BUDD SILT 27: JILT SPY DUTY GLOW COWL ROT 28: THEM OW COLA RUNT BONG SCOT 29: COT MASH BARR BRIM NAN FLAG 30: CAN KNEE CAST NAME FOLK BILK Or for OPIE: &prompt.user; opiekey -n 5 30 zz99999 Using the MD5 algorithm to compute response. Reminder: Don't use opiekey from telnet or dial-in sessions. Enter secret pass phrase: <secret password> 26: JOAN BORE FOSS DES NAY QUIT 27: LATE BIAS SLAY FOLK MUCH TRIG 28: SALT TIN ANTI LOON NEAL USE 29: RIO ODIN GO BYE FURY TIC 30: GREW JIVE SAN GIRD BOIL PHI The requests five keys in sequence, the specifies what the last iteration number should be. Note that these are printed out in reverse order of eventual use. If you are really paranoid, you might want to write the results down by hand; otherwise you can cut-and-paste into lpr. Note that each line shows both the iteration count and the one-time password; you may still find it handy to scratch off passwords as you use them. Restricting Use of &unix; Passwords S/Key can place restrictions on the use of &unix; passwords based on the host name, user name, terminal port, or IP address of a login session. These restrictions can be found in the configuration file /etc/skey.access. The &man.skey.access.5; manual page has more information on the complete format of the file and also details some security cautions to be aware of before depending on this file for security. If there is no /etc/skey.access file (this is the default on &os; 4.X systems), then all users will be allowed to use &unix; passwords. If the file exists, however, then all users will be required to use S/Key unless explicitly permitted to do otherwise by configuration statements in the skey.access file. In all cases, &unix; passwords are permitted on the console. Here is a sample skey.access configuration file which illustrates the three most common sorts of configuration statements: permit internet 192.168.0.0 255.255.0.0 permit user fnord permit port ttyd0 The first line (permit internet) allows users whose IP source address (which is vulnerable to spoofing) matches the specified value and mask, to use &unix; passwords. This should not be considered a security mechanism, but rather, a means to remind authorized users that they are using an insecure network and need to use S/Key for authentication. The second line (permit user) allows the specified username, in this case fnord, to use &unix; passwords at any time. Generally speaking, this should only be used for people who are either unable to use the key program, like those with dumb terminals, or those who are ineducable. The third line (permit port) allows all users logging in on the specified terminal line to use &unix; passwords; this would be used for dial-ups. OPIE can restrict the use of &unix; passwords based on the IP address of a login session just like S/Key does. The relevant file is /etc/opieaccess, which is present by default on &os; 5.0 and newer systems. Please check &man.opieaccess.5; for more information on this file and which security considerations you should be aware of when using it. Here is a sample opieaccess file: permit 192.168.0.0 255.255.0.0 This line allows users whose IP source address (which is vulnerable to spoofing) matches the specified value and mask, to use &unix; passwords at any time. If no rules in opieaccess are matched, the default is to deny non-OPIE logins. Tom Rhodes Written by: TCP Wrappers TCP Wrappers Anyone familiar with &man.inetd.8; has probably heard of TCP Wrappers at some point. But few individuals seem to fully comprehend its usefulness in a network environment. It seems that everyone wants to install a firewall to handle network connections. While a firewall has a wide variety of uses, there are some things that a firewall not handle such as sending text back to the connection originator. The TCP software does this and much more. In the next few sections many of the TCP Wrappers features will be discussed, and, when applicable, example configuration lines will be provided. The TCP Wrappers software extends the abilities of inetd to provide support for every server daemon under its control. Using this method it is possible to provide logging support, return messages to connections, permit a daemon to only accept internal connections, etc. While some of these features can be provided by implementing a firewall, this will add not only an extra layer of protection but go beyond the amount of control a firewall can provide. The added functionality of TCP Wrappers should not be considered a replacement for a good firewall; however, but should used in conjunction with a firewall and other security configurations to add an extra layer of protection for the system. Since this is an extension to the configuration of inetd, the reader is expected have read the inetd configuration section. While programs run by &man.inetd.8; are not exactly daemons, they have traditionally been called daemons. This is the term we will use in this section too. Initial Configuration The only requirement of using TCP Wrappers in &os; is to ensure the inetd server is started from rc.conf with the option; this is the default setting. Of course, proper configuration of /etc/hosts.allow is also expected, but &man.syslogd.8; will throw messages in the system logs in these cases. Unlike other implementations of TCP Wrappers, the use of hosts.deny has been deprecated. All configuration options should be placed in /etc/hosts.allow. In the simplest configuration, daemon connection policies are set to either be permitted or blocked depending on the options in /etc/hosts.allow. The default configuration in &os; is to allow a connection to every daemon started with inetd. Changing this will be discussed only after the basic configuration is covered. Basic configuration usually takes the form of daemon : address : action. Where daemon is the daemon name which inetd started. The address can be a valid hostname, an IP address or an IPv6 address enclosed in brackets ([ ]). The action field can be either allow or deny to grant or deny access appropriately. Keep in mind that configuration works off a first rule match semantic, meaning that the configuration file is scanned in ascending order for a matching rule. When a match is found the rule is applied and the search process will halt. Several other options exist but they will be explained in a later section. A simple configuration line may easily be constructed from that information alone. For example, to allow POP3 connections via the mail/qpopper daemon, the following lines should be appended to hosts.allow: # This line is required for POP3 connections: qpopper : ALL : allow After adding this line, inetd will need restarted. This can be accomplished by use of the &man.kill.1; command, or with the restart parameter with /etc/rc.d/inetd. Advanced Configuration TCP Wrappers has advanced options too; they will allow for more control over the way connections are handled. In some cases it may be a good idea to return a comment to certain hosts or daemon connections. In other cases, perhaps a log file should be recorded or an email sent to the administrator. Other situations may require the use of a service for local connections only. This is all possible through the use of configuration options known as wildcards, expansion characters and external command execution. The next two sections are written to cover these situations. External Commands Suppose that a situation occurs where a connection should be denied yet a reason should be sent to the individual who attempted to establish that connection. How could it be done? That action can be made possible by using the option. When a connection attempt is made, will be called to execute a shell command or script. An example already exists in the hosts.allow file: # The rest of the daemons are protected. ALL : ALL \ : severity auth.info \ : twist /bin/echo "You are not welcome to use %d from %h." This example shows that the message, You are not allowed to use daemon from hostname. will be returned for any daemon not previously configured in the access file. This is extremely useful for sending a reply back to the connection initiator right after the established connection is dropped. Note that any message returned must be wrapped in quote " characters; there are no exceptions to this rule. It may be possible to launch a denial of service attack on the server if an attacker, or group of attackers could flood these daemons with connection requests. Another possibility is to use the option in these cases. Like , the implicitly denies the connection and may be used to run external shell commands or scripts. Unlike , will not send a reply back to the individual who established the connection. For an example, consider the following configuration line: # We do not allow connections from example.com: ALL : .example.com \ : spawn (/bin/echo %a from %h attempted to access %d >> \ /var/log/connections.log) \ : deny This will deny all connection attempts from the *.example.com domain; simultaneously logging the hostname, IP address and the daemon which they attempted to access in the /var/log/connections.log file. Aside from the already explained substitution characters above, e.g. %a, a few others exist. See the &man.hosts.access.5; manual page for the complete list. Wildcard Options Thus far the ALL example has been used continuously throughout the examples. Other options exist which could extend the functionality a bit further. For instance, ALL may be used to match every instance of either a daemon, domain or an IP address. Another wildcard available is PARANOID which may be used to match any host which provides an IP address that may be forged. In other words, paranoid may be used to define an action to be taken whenever a connection is made from an IP address that differs from its hostname. The following example may shed some more light on this discussion: # Block possibly spoofed requests to sendmail: sendmail : PARANOID : deny In that example all connection requests to sendmail which have an IP address that varies from its hostname will be denied. Using the PARANOID may severely cripple servers if the client or server has a broken DNS setup. Administrator discretion is advised. To learn more about wildcards and their associated functionality, see the &man.hosts.access.5; manual page. Before any of the specific configuration lines above will work, the first configuration line should be commented out in hosts.allow. This was noted at the beginning of this section. Mark Murray Contributed by Mark Dapoz Based on a contribution by <application>KerberosIV</application> Kerberos is a network add-on system/protocol that allows users to authenticate themselves through the services of a secure server. Services such as remote login, remote copy, secure inter-system file copying and other high-risk tasks are made considerably safer and more controllable. The following instructions can be used as a guide on how to set up Kerberos as distributed for &os;. However, you should refer to the relevant manual pages for a complete description. Installing <application>KerberosIV</application> MIT KerberosIV Installing Kerberos is an optional component of &os;. The easiest way to install this software is by selecting the krb4 or krb5 distribution in sysinstall during the initial installation of &os;. This will install the eBones (KerberosIV) or Heimdal (Kerberos5) implementation of Kerberos. These implementations are included because they are developed outside the USA/Canada and were thus available to system owners outside those countries during the era of restrictive export controls on cryptographic code from the USA. Alternatively, the MIT implementation of Kerberos is available from the ports collection as security/krb5. Creating the Initial Database This is done on the Kerberos server only. First make sure that you do not have any old Kerberos databases around. You should change to the directory /etc/kerberosIV and check that only the following files are present: &prompt.root; cd /etc/kerberosIV &prompt.root; ls README krb.conf krb.realms If any additional files (such as principal.* or master_key) exist, then use the kdb_destroy command to destroy the old Kerberos database, or if Kerberos is not running, simply delete the extra files. You should now edit the krb.conf and krb.realms files to define your Kerberos realm. In this case the realm will be EXAMPLE.COM and the server is grunt.example.com. We edit or create the krb.conf file: &prompt.root; cat krb.conf EXAMPLE.COM EXAMPLE.COM grunt.example.com admin server CS.BERKELEY.EDU okeeffe.berkeley.edu ATHENA.MIT.EDU kerberos.mit.edu ATHENA.MIT.EDU kerberos-1.mit.edu ATHENA.MIT.EDU kerberos-2.mit.edu ATHENA.MIT.EDU kerberos-3.mit.edu LCS.MIT.EDU kerberos.lcs.mit.edu TELECOM.MIT.EDU bitsy.mit.edu ARC.NASA.GOV trident.arc.nasa.gov In this case, the other realms do not need to be there. They are here as an example of how a machine may be made aware of multiple realms. You may wish to not include them for simplicity. The first line names the realm in which this system works. The other lines contain realm/host entries. The first item on a line is a realm, and the second is a host in that realm that is acting as a key distribution center. The words admin server following a host's name means that host also provides an administrative database server. For further explanation of these terms, please consult the Kerberos manual pages. Now we have to add grunt.example.com to the EXAMPLE.COM realm and also add an entry to put all hosts in the .example.com domain in the EXAMPLE.COM realm. The krb.realms file would be updated as follows: &prompt.root; cat krb.realms grunt.example.com EXAMPLE.COM .example.com EXAMPLE.COM .berkeley.edu CS.BERKELEY.EDU .MIT.EDU ATHENA.MIT.EDU .mit.edu ATHENA.MIT.EDU Again, the other realms do not need to be there. They are here as an example of how a machine may be made aware of multiple realms. You may wish to remove them to simplify things. The first line puts the specific system into the named realm. The rest of the lines show how to default systems of a particular subdomain to a named realm. Now we are ready to create the database. This only needs to run on the Kerberos server (or Key Distribution Center). Issue the kdb_init command to do this: &prompt.root; kdb_init Realm name [default ATHENA.MIT.EDU ]: EXAMPLE.COM You will be prompted for the database Master Password. It is important that you NOT FORGET this password. Enter Kerberos master key: Now we have to save the key so that servers on the local machine can pick it up. Use the kstash command to do this: &prompt.root; kstash Enter Kerberos master key: Current Kerberos master key version is 1. Master key entered. BEWARE! This saves the encrypted master password in /etc/kerberosIV/master_key. Making It All Run KerberosIV Inital Startup Two principals need to be added to the database for each system that will be secured with Kerberos. Their names are kpasswd and rcmd. These two principals are made for each system, with the instance being the name of the individual system. These daemons, kpasswd and rcmd allow other systems to change Kerberos passwords and run commands like &man.rcp.1;, &man.rlogin.1; and &man.rsh.1;. Now let us add these entries: &prompt.root; kdb_edit Opening database... Enter Kerberos master key: Current Kerberos master key version is 1. Master key entered. BEWARE! Previous or default values are in [brackets] , enter return to leave the same, or new value. Principal name: passwd Instance: grunt <Not found>, Create [y] ? y Principal: passwd, Instance: grunt, kdc_key_ver: 1 New Password: <---- enter RANDOM here Verifying password New Password: <---- enter RANDOM here Random password [y] ? y Principal's new key version = 1 Expiration date (enter yyyy-mm-dd) [ 2000-01-01 ] ? Max ticket lifetime (*5 minutes) [ 255 ] ? Attributes [ 0 ] ? Edit O.K. Principal name: rcmd Instance: grunt <Not found>, Create [y] ? Principal: rcmd, Instance: grunt, kdc_key_ver: 1 New Password: <---- enter RANDOM here Verifying password New Password: <---- enter RANDOM here Random password [y] ? Principal's new key version = 1 Expiration date (enter yyyy-mm-dd) [ 2000-01-01 ] ? Max ticket lifetime (*5 minutes) [ 255 ] ? Attributes [ 0 ] ? Edit O.K. Principal name: <---- null entry here will cause an exit Creating the Server File We now have to extract all the instances which define the services on each machine. For this we use the ext_srvtab command. This will create a file which must be copied or moved by secure means to each Kerberos client's /etc/kerberosIV directory. This file must be present on each server and client, and is crucial to the operation of Kerberos. &prompt.root; ext_srvtab grunt Enter Kerberos master key: Current Kerberos master key version is 1. Master key entered. BEWARE! Generating 'grunt-new-srvtab'.... Now, this command only generates a temporary file which must be renamed to srvtab so that all the servers can pick it up. Use the &man.mv.1; command to move it into place on the original system: &prompt.root; mv grunt-new-srvtab srvtab If the file is for a client system, and the network is not deemed safe, then copy the client-new-srvtab to removable media and transport it by secure physical means. Be sure to rename it to srvtab in the client's /etc/kerberosIV directory, and make sure it is mode 600: &prompt.root; mv grumble-new-srvtab srvtab &prompt.root; chmod 600 srvtab Populating the Database We now have to add some user entries into the database. First let us create an entry for the user jane. Use the kdb_edit command to do this: &prompt.root; kdb_edit Opening database... Enter Kerberos master key: Current Kerberos master key version is 1. Master key entered. BEWARE! Previous or default values are in [brackets] , enter return to leave the same, or new value. Principal name: jane Instance: <Not found>, Create [y] ? y Principal: jane, Instance: , kdc_key_ver: 1 New Password: <---- enter a secure password here Verifying password New Password: <---- re-enter the password here Principal's new key version = 1 Expiration date (enter yyyy-mm-dd) [ 2000-01-01 ] ? Max ticket lifetime (*5 minutes) [ 255 ] ? Attributes [ 0 ] ? Edit O.K. Principal name: <---- null entry here will cause an exit Testing It All Out First we have to start the Kerberos daemons. Note that if you have correctly edited your /etc/rc.conf then this will happen automatically when you reboot. This is only necessary on the Kerberos server. Kerberos clients will automatically get what they need from the /etc/kerberosIV directory. &prompt.root; kerberos & Kerberos server starting Sleep forever on error Log file is /var/log/kerberos.log Current Kerberos master key version is 1. Master key entered. BEWARE! Current Kerberos master key version is 1 Local realm: EXAMPLE.COM &prompt.root; kadmind -n & KADM Server KADM0.0A initializing Please do not use 'kill -9' to kill this job, use a regular kill instead Current Kerberos master key version is 1. Master key entered. BEWARE! Now we can try using the kinit command to get a ticket for the ID jane that we created above: &prompt.user; kinit jane MIT Project Athena (grunt.example.com) Kerberos Initialization for "jane" Password: Try listing the tokens using klist to see if we really have them: &prompt.user; klist Ticket file: /tmp/tkt245 Principal: jane@EXAMPLE.COM Issued Expires Principal Apr 30 11:23:22 Apr 30 19:23:22 krbtgt.EXAMPLE.COM@EXAMPLE.COM Now try changing the password using &man.passwd.1; to check if the kpasswd daemon can get authorization to the Kerberos database: &prompt.user; passwd realm EXAMPLE.COM Old password for jane: New Password for jane: Verifying password New Password for jane: Password changed. Adding <command>su</command> Privileges Kerberos allows us to give each user who needs root privileges their own separate &man.su.1; password. We could now add an ID which is authorized to &man.su.1; to root. This is controlled by having an instance of root associated with a principal. Using kdb_edit we can create the entry jane.root in the Kerberos database: &prompt.root; kdb_edit Opening database... Enter Kerberos master key: Current Kerberos master key version is 1. Master key entered. BEWARE! Previous or default values are in [brackets] , enter return to leave the same, or new value. Principal name: jane Instance: root <Not found>, Create [y] ? y Principal: jane, Instance: root, kdc_key_ver: 1 New Password: <---- enter a SECURE password here Verifying password New Password: <---- re-enter the password here Principal's new key version = 1 Expiration date (enter yyyy-mm-dd) [ 2000-01-01 ] ? Max ticket lifetime (*5 minutes) [ 255 ] ? 12 <--- Keep this short! Attributes [ 0 ] ? Edit O.K. Principal name: <---- null entry here will cause an exit Now try getting tokens for it to make sure it works: &prompt.root; kinit jane.root MIT Project Athena (grunt.example.com) Kerberos Initialization for "jane.root" Password: Now we need to add the user to root's .klogin file: &prompt.root; cat /root/.klogin jane.root@EXAMPLE.COM Now try doing the &man.su.1;: &prompt.user; su Password: and take a look at what tokens we have: &prompt.root; klist Ticket file: /tmp/tkt_root_245 Principal: jane.root@EXAMPLE.COM Issued Expires Principal May 2 20:43:12 May 3 04:43:12 krbtgt.EXAMPLE.COM@EXAMPLE.COM Using Other Commands In an earlier example, we created a principal called jane with an instance root. This was based on a user with the same name as the principal, and this is a Kerberos default; that a <principal>.<instance> of the form <username>.root will allow that <username> to &man.su.1; to root if the necessary entries are in the .klogin file in root's home directory: &prompt.root; cat /root/.klogin jane.root@EXAMPLE.COM Likewise, if a user has in their own home directory lines of the form: &prompt.user; cat ~/.klogin jane@EXAMPLE.COM jack@EXAMPLE.COM This allows anyone in the EXAMPLE.COM realm who has authenticated themselves as jane or jack (via kinit, see above) to access to jane's account or files on this system (grunt) via &man.rlogin.1;, &man.rsh.1; or &man.rcp.1;. For example, jane now logs into another system using Kerberos: &prompt.user; kinit MIT Project Athena (grunt.example.com) Password: &prompt.user; rlogin grunt Last login: Mon May 1 21:14:47 from grumble Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD BUILT-19950429 (GR386) #0: Sat Apr 29 17:50:09 SAT 1995 Or jack logs into jane's account on the same machine (jane having set up the .klogin file as above, and the person in charge of Kerberos having set up principal jack with a null instance): &prompt.user; kinit &prompt.user; rlogin grunt -l jane MIT Project Athena (grunt.example.com) Password: Last login: Mon May 1 21:16:55 from grumble Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD BUILT-19950429 (GR386) #0: Sat Apr 29 17:50:09 SAT 1995 Tillman Hodgson Contributed by Mark Murray Based on a contribution by <application>Kerberos5</application> Every &os; release beyond &os;-5.1 includes support only for Kerberos5. Hence Kerberos5 is the only version included, and its configuration is similar in many aspects to that of KerberosIV. The following information only applies to Kerberos5 in post &os;-5.0 releases. Users who wish to use the KerberosIV package may install the security/krb4 port. Kerberos is a network add-on system/protocol that allows users to authenticate themselves through the services of a secure server. Services such as remote login, remote copy, secure inter-system file copying and other high-risk tasks are made considerably safer and more controllable. Kerberos can be described as an identity-verifying proxy system. It can also be described as a trusted third-party authentication system. Kerberos provides only one function — the secure authentication of users on the network. It does not provide authorization functions (what users are allowed to do) or auditing functions (what those users did). After a client and server have used Kerberos to prove their identity, they can also encrypt all of their communications to assure privacy and data integrity as they go about their business. Therefore it is highly recommended that Kerberos be used with other security methods which provide authorization and audit services. The following instructions can be used as a guide on how to set up Kerberos as distributed for &os;. However, you should refer to the relevant manual pages for a complete description. For purposes of demonstrating a Kerberos installation, the various name spaces will be handled as follows: The DNS domain (zone) will be example.org. The Kerberos realm will be EXAMPLE.ORG. Please use real domain names when setting up Kerberos even if you intend to run it internally. This avoids DNS problems and assures inter-operation with other Kerberos realms. History Kerberos5 History Kerberos was created by MIT as a solution to network security problems. The Kerberos protocol uses strong cryptography so that a client can prove its identity to a server (and vice versa) across an insecure network connection. Kerberos is both the name of a network authentication protocol and an adjective to describe programs that implement the program (Kerberos telnet, for example). The current version of the protocol is version 5, described in RFC 1510. Several free implementations of this protocol are available, covering a wide range of operating systems. The Massachusetts Institute of Technology (MIT), where Kerberos was originally developed, continues to develop their Kerberos package. It is commonly used in the US as a cryptography product, as such it has historically been affected by US export regulations. The MIT Kerberos is available as a port (security/krb5). Heimdal Kerberos is another version 5 implementation, and was explicitly developed outside of the US to avoid export regulations (and is thus often included in non-commercial &unix; variants). The Heimdal Kerberos distribution is available as a port (security/heimdal), and a minimal installation of it is included in the base &os; install. In order to reach the widest audience, these instructions assume the use of the Heimdal distribution included in &os;. Setting up a Heimdal <acronym>KDC</acronym> Kerberos5 Key Distribution Center Configuration The Key Distribution Center (KDC) is the centralized authentication service that Kerberos provides — it is the computer that issues Kerberos tickets. The KDC is considered trusted by all other computers in the Kerberos realm, and thus has heightened security concerns. Note that while running the Kerberos server requires very few computing resources, a dedicated machine acting only as a KDC is recommended for security reasons. To begin setting up a KDC, ensure that your /etc/rc.conf file contains the correct settings to act as a KDC (you may need to adjust paths to reflect your own system): kerberos5_server_enable="YES" kadmind5_server_enable="YES" kerberos_stash="YES" The is only available in &os; 4.X. Next we will set up your Kerberos config file, /etc/krb5.conf: [libdefaults] default_realm = EXAMPLE.ORG [realms] EXAMPLE.ORG = { kdc = kerberos.example.org admin_server = kerberos.example.org } [domain_realm] .example.org = EXAMPLE.ORG Note that this /etc/krb5.conf file implies that your KDC will have the fully-qualified hostname of kerberos.example.org. You will need to add a CNAME (alias) entry to your zone file to accomplish this if your KDC has a different hostname. For large networks with a properly configured BIND DNS server, the above example could be trimmed to: [libdefaults] default_realm = EXAMPLE.ORG With the following lines being appended to the example.org zonefile: _kerberos._udp IN SRV 01 00 88 kerberos.example.org. _kerberos._tcp IN SRV 01 00 88 kerberos.example.org. _kpasswd._udp IN SRV 01 00 464 kerberos.example.org. _kerberos-adm._tcp IN SRV 01 00 749 kerberos.example.org. _kerberos IN TXT EXAMPLE.ORG. For clients to be able to find the Kerberos services, you must have either a fully configured /etc/krb5.conf or a miminally configured /etc/krb5.conf and a properly configured DNS server. Next we will create the Kerberos database. This database contains the keys of all principals encrypted with a master password. You are not required to remember this password, it will be stored in a file (/var/heimdal/m-key). To create the master key, run kstash and enter a password. Once the master key has been created, you can initialize the database using the kadmin program with the -l option (standing for local). This option instructs kadmin to modify the database files directly rather than going through the kadmind network service. This handles the chicken-and-egg problem of trying to connect to the database before it is created. Once you have the kadmin prompt, use the init command to create your realms initial database. Lastly, while still in kadmin, create your first principal using the add command. Stick to the defaults options for the principal for now, you can always change them later with the modify command. Note that you can use the ? command at any prompt to see the available options. A sample database creation session is shown below: &prompt.root; kstash Master key: xxxxxxxx Verifying password - Master key: xxxxxxxx &prompt.root; kadmin -l kadmin> init EXAMPLE.ORG Realm max ticket life [unlimited]: kadmin> add tillman Max ticket life [unlimited]: Max renewable life [unlimited]: Attributes []: Password: xxxxxxxx Verifying password - Password: xxxxxxxx Now it is time to start up the KDC services. Run /etc/rc.d/kerberos start and /etc/rc.d/kadmind start to bring up the services. Note that you won't have any kerberized daemons running at this point but you should be able to confirm the that the KDC is functioning by obtaining and listing a ticket for the principal (user) that you just created from the command-line of the KDC itself: &prompt.user; k5init tillman tillman@EXAMPLE.ORG's Password: &prompt.user; k5list Credentials cache: FILE:/tmp/krb5cc_500 Principal: tillman@EXAMPLE.ORG Issued Expires Principal Aug 27 15:37:58 Aug 28 01:37:58 krbtgt/EXAMPLE.ORG@EXAMPLE.ORG <application>Kerberos</application> enabling a server with Heimdal services Kerberos5 Enabling Services First, we need a copy of the Kerberos configuration file, /etc/krb5.conf. To do so, simply copy it over to the client computer from the KDC in a secure fashion (using network utilities, such as &man.scp.1;, or physically via a floppy disk). Next you need a /etc/krb5.keytab file. This is the major difference between a server providing Kerberos enabled daemons and a workstation — the server must have a keytab file. This file contains the servers host key, which allows it and the KDC to verify each others identity. It must be transmitted to the server in a secure fashion, as the security of the server can be broken if the key is made public. This explicitly means that transferring it via a clear text channel, such as FTP, is a very bad idea. Typically, you transfer to the keytab to the server using the kadmin program. This is handy because you also need to create the host principal (the KDC end of the krb5.keytab) using kadmin. Note that you must have already obtained a ticket and that this ticket must be allowed to use the kadmin interface in the kadmind.acl. See the section titled Remote administration in the Heimdal info pages (info heimdal) for details on designing access control lists. If you do not want to enable remote kadmin access, you can simply securely connect to the KDC (via local console, &man.ssh.1; or Kerberos &man.telnet.1;) and perform administration locally using kadmin -l. After installing the /etc/krb5.conf file, you can use kadmin from the Kerberos server. The add --random-key command will let you add the servers host principal, and the ext command will allow you to extract the servers host principal to its own keytab. For example: &prompt.root; kadmin kadmin> add --random-key host/myserver.example.org Max ticket life [unlimited]: Max renewable life [unlimited]: Attributes []: kadmin> ext host/myserver.example.org kadmin> exit Note that the ext command (short for extract) stores the extracted key in /etc/krb5.keytab by default. If you do not have kadmind running on the KDC (possibly for security reasons) and thus do not have access to kadmin remotely, you can add the host principal (host/myserver.EXAMPLE.ORG) directly on the KDC and then extract it to a temporary file (to avoid over-writing the /etc/krb5.keytab on the KDC) using something like this: &prompt.root; kadmin kadmin> ext --keytab=/tmp/example.keytab host/myserver.example.org kadmin> exit You can then securely copy the keytab to the server computer (using scp or a floppy, for example). Be sure to specify a non-default keytab name to avoid over-writing the keytab on the KDC. At this point your server can communicate with the KDC (due to its krb5.conf file) and it can prove its own identity (due to the krb5.keytab file). It is now ready for you to enable some Kerberos services. For this example we will enable the telnet service by putting a line like this into your /etc/inetd.conf and then restarting the &man.inetd.8; service with /etc/rc.d/inetd restart: telnet stream tcp nowait root /usr/libexec/telnetd telnetd -a user The critical bit is that the -a (for authentication) type is set to user. Consult the &man.telnetd.8; manual page for more details. <application>Kerberos</application> enabling a client with Heimdal Kerberos5 Client Configuration Setting up a client computer is almost trivially easy. As far as Kerberos configuration goes, you only need the Kerberos configuration file, located at /etc/krb5.conf. Simply securely copy it over to the client computer from the KDC. Test your client computer by attempting to use kinit, klist, and kdestroy from the client to obtain, show, and then delete a ticket for the principal you created above. You should also be able to use Kerberos applications to connect to Kerberos enabled servers, though if that does not work and obtaining a ticket does the problem is likely with the server and not with the client or the KDC. When testing an application like telnet, try using a packet sniffer (such as &man.tcpdump.1;) to confirm that your password is not sent in the clear. Try using telnet with the -x option, which encrypts the entire data stream (similar to ssh). The core Kerberos client applications (traditionally named kinit, klist, kdestroy, and kpasswd) are installed in the base &os; install. Note that &os; versions prior to 5.0 renamed them to k5init, k5list, k5destroy, k5passwd, and k5stash (though it is typically only used once). Various non-core Kerberos client applications are also installed by default. This is where the minimal nature of the base Heimdal installation is felt: telnet is the only Kerberos enabled service. The Heimdal port adds some of the missing client applications: Kerberos enabled versions of ftp, rsh, rcp, rlogin, and a few other less common programs. The MIT port also contains a full suite of Kerberos client applications. User configuration files: <filename>.k5login</filename> and <filename>.k5users</filename> Kerberos5 User Configuration Files Users within a realm typically have their Kerberos principal (such as tillman@EXAMPLE.ORG) mapped to a local user account (such as a local account named tillman). Client applications such as telnet usually do not require a user name or a principal. Occasionally, however, you want to grant access to a local user account to someone who does not have a matching Kerberos principal. For example, tillman@EXAMPLE.ORG may need access to the local user account webdevelopers. Other principals may also need access to that local account. The .k5login and .k5users files, placed in a users home directory, can be used similar to a powerful combination of .hosts and .rhosts, solving this problem. For example, if a .k5login with the following contents: tillman@example.org jdoe@example.org Were to be placed into the home directory of the local user webdevelopers then both principals listed would have access to that account without requiring a shared password. Reading the manual pages for these commands is recommended. Note that the ksu manual page covers .k5users. <application>Kerberos</application> Tips, Tricks, and Troubleshooting Kerberos5 Troubleshooting When using either the Heimdal or MIT Kerberos ports ensure that your PATH environment variable lists the Kerberos versions of the client applications before the system versions. Do all the computers in your realm have synchronized time settings? If not, authentication may fail. describes how to synchronize clocks using NTP. MIT and Heimdal inter-operate nicely. Except for kadmin, the protocol for which is not standardized. If you change your hostname, you also need to change your host/ principal and update your keytab. This also applies to special keytab entries like the www/ principal used for Apache's www/mod_auth_kerb. All hosts in your realm must be resolvable (both forwards and reverse) in DNS (or /etc/hosts as a minimum). CNAMEs will work, but the A and PTR records must be correct and in place. The error message isn't very intuitive: Kerberos5 refuses authentication because Read req failed: Key table entry not found. Some operating systems that may being acting as clients to your KDC do not set the permissions for ksu to be setuid root. This means that ksu does not work, which is a good security idea but annoying. This is not a KDC error. With MIT Kerberos, if you want to allow a principal to have a ticket life longer than the default ten hours, you must use modify_principal in kadmin to change the maxlife of both the principal in question and the krbtgt principal. Then the principal can use the -l option with kinit to request a ticket with a longer lifetime. If you run a packet sniffer on your KDC to add in troubleshooting and then run kinit from a workstation, you will notice that your TGT is sent immediately upon running kinit — even before you type your password! The explanation is that the Kerberos server freely transmits a TGT (Ticket Granting Ticket) to any unauthorized request; however, every TGT is encrypted in a key derived from the user's password. Therefore, when a user types their password it is not being sent to the KDC, it is being used to decrypt the TGT that kinit already obtained. If the decryption process results in a valid ticket with a valid time stamp, the user has valid Kerberos credentials. These credentials include a session key for establishing secure communications with the Kerberos server in the future, as well as the actual ticket-granting ticket, which is actually encrypted with the Kerberos server's own key. This second layer of encryption is unknown to the user, but it is what allows the Kerberos server to verify the authenticity of each TGT. If you want to use long ticket lifetimes (a week, for example) and you are using OpenSSH to connect to the machine where your ticket is stored, make sure that Kerberos is set to no in your sshd_config or else your tickets will be deleted when you log out. Remember that host principals can have a longer ticket lifetime as well. If your user principal has a lifetime of a week but the host you are connecting to has a lifetime of nine hours, you will have an expired host principal in your cache and the ticket cache will not work as expected. When setting up a krb5.dict file to prevent specific bad passwords from being used (the manual page for kadmind covers this briefly), remember that it only applies to principals that have a password policy assigned to them. The krb5.dict files format is simple: one string per line. Creating a symbolic link to /usr/share/dict/words might be useful. Differences with the <acronym>MIT</acronym> port The major difference between the MIT and Heimdal installs relates to the kadmin program which has a different (but equivalent) set of commands and uses a different protocol. This has a large implications if your KDC is MIT as you will not be able to use the Heimdal kadmin program to administer your KDC remotely (or vice versa, for that matter). The client applications may also take slightly different command line options to accomplish the same tasks. Following the instructions on the MIT Kerberos web site () is recommended. Be careful of path issues: the MIT port installs into /usr/local/ by default, and the normal system applications may be run instead of MIT if your PATH environment variable lists the system directories first. With the MIT security/krb5 port that is provided by &os;, be sure to read the /usr/local/share/doc/krb5/README.FreeBSD file installed by the port if you want to understand why logins via telnetd and klogind behave somewhat oddly. Most importantly, correcting the incorrect permissions on cache file behavior requires that the login.krb5 binary be used for authentication so that it can properly change ownership for the forwarded credentials. Mitigating limitations found in <application>Kerberos</application> Kerberos5 Limitations and Shortcomings <application>Kerberos</application> is an all-or-nothing approach Every service enabled on the network must be modified to work with Kerberos (or be otherwise secured against network attacks) or else the users credentials could be stolen and re-used. An example of this would be Kerberos enabling all remote shells (via rsh and telnet, for example) but not converting the POP3 mail server which sends passwords in plain text. <application>Kerberos</application> is intended for single-user workstations In a multi-user environment, Kerberos is less secure. This is because it stores the tickets in the /tmp directory, which is readable by all users. If a user is sharing a computer with several other people simultaneously (i.e. multi-user), it is possible that the user's tickets can be stolen (copied) by another user. This can be overcome with the -c filename command-line option or (preferably) the KRB5CCNAME environment variable, but this is rarely done. In principal, storing the ticket in the users home directory and using simple file permissions can mitigate this problem. The KDC is a single point of failure By design, the KDC must be as secure as the master password database is contained on it. The KDC should have absolutely no other services running on it and should be physically secured. The danger is high because Kerberos stores all passwords encrypted with the same key (the master key), which in turn is stored as a file on the KDC. As a side note, a compromised master key is not quite as bad as one might normally fear. The master key is only used to encrypt the Kerberos database and as a seed for the random number generator. As long as access to your KDC is secure, an attacker cannot do much with the master key. Additionally, if the KDC is unavailable (perhaps due to a denial of service attack or network problems) the network services are unusable as authentication can not be performed, a recipe for a denial-of-service attack. This can alleviated with multiple KDCs (a single master and one or more slaves) and with careful implementation of secondary or fall-back authentication (PAM is excellent for this). <application>Kerberos</application> Shortcomings Kerberos allows users, hosts and services to authenticate between themselves. It does not have a mechanism to authenticate the KDC to the users, hosts or services. This means that a trojanned kinit (for example) could record all user names and passwords. Something like security/tripwire or other file system integrity checking tools can alleviate this. Resources and further information Kerberos5 External Resources The Kerberos FAQ Designing an Authentication System: a Dialog in Four Scenes RFC 1510, The Kerberos Network Authentication Service (V5) MIT Kerberos home page Heimdal Kerberos home page Joseph J. Barbish Contributed by Brad Davis Converted to SGML and updated by Firewalls firewall security firewalls Introduction All software-based firewalls provide some way to filter incoming and outgoing traffic that flows through your system. The firewall uses one or more sets of rules to inspect the network packets as they come in or go out of your network connections and either allows the traffic through or blocks it. The rules of the firewall can inspect one or more characteristics of the packets, including but not limited to the protocol type, the source or destination host address and the source or destination port. Firewalls greatly enhance the security of your network, your applications and services. They can be used to do one of more of the following things: To protect and insulate the applications, services and machines of your internal network from unwanted traffic coming in from the public Internet. To limit or disable access from hosts of the internal network to services of the public Internet. To support network address translation (NAT), which allows your internal network to use private IP addresses and share a single connection to the public Internet (either with a single IP address or by a shared pool of automatically assigned public addresses). Firewall Rule Set Types Constructing a software application firewall rule set may seem to be trivial, but most people get it wrong. The most common mistake is to create an exclusive firewall rather than an inclusive firewall. An exclusive firewall allows all services through except for those matching a set of rules that block certain services. An inclusive firewall does the reverse. It only allows services matching the rules through and blocks everything else. This way you can control what services can originate behind the firewall destined for the public Internet and also control which services originating from the public Internet may access your network. Inclusive firewalls are much, much safer than exclusive firewalls. When you use your browser to access a web site there are many internal functions that happen before your screen fills with the data from the target web site. Your browser does not receive one large file containing all the data and display format instructions at one time. Each internal function accesses the public Internet in multiple send/receive cycles of packets of information. When all the packets containing the data finally arrive, the data contained in the packets is combined together to fill your screen. Each service (DNS, HTTP, etc) has its own port number. The port number 80 is for HTTP services. So you can code your firewall to only allow web page session start requests originating from your LAN to pass through the firewall out to the public Internet. Security can be tightened further by telling the firewall to monitor the send/receive cycles of all the packets making up that session until the session completes. These are called stateful capabilities and provides the maximum level of protection. A firewall rule set that does not implement stateful capabilities on all the services being authorized is an insecure firewall that is still open to many of the most common methods of attack. Firewall Software Applications &os; has two different firewall software products built into the base system. They are IPFILTER (i.e. also known as IPF) and IPFIREWALL (i.e. also known as IPFW). IPFIREWALL has the built in DUMMYNET traffic shaper facilities for controlling bandwidth usage. IPFILTER does not have a built in traffic shaper facility for controlling bandwidth usage, but the ALTQ port application can be used to accomplish the same function. The DUMMYNET feature and ALTQ is generally useful only to large ISPs or commercial users. Both IPF and IPFW use rules to control the access of packets to and from your system, although they go about it different ways and have different rule syntaxes. The IPFW sample rule set (found in /etc/rc.firewall) delivered in the basic install is outdated, complicated and does not use stateful rules on the interface facing the public Internet. It exclusively uses legacy stateless rules which only have the ability to open or close the service ports. The IPFW example stateful rules sets presented here supercede the /etc/rc.firewall file distributed with the system. Stateful rules have technically advanced interrogation abilities capable of defending against the flood of different methods currently employed by attackers. Both of these firewall software solutions IPF and IPFW still maintain their legacy heritage of their original rule processing order and reliance on non-stateful rules. These outdated concepts are not covered here, only the new, modern stateful rule construct and rule processing order is presented. You should read about both of them and make your own decision on which one best fits your needs. The author prefers IPFILTER because its stateful rules are much less complicated to use in a NAT environment and it has a built in ftp proxy that simplifies the rules to allow secure outbound FTP usage. If is also more appropriate to the knowledge level of the inexperienced firewall user. Since all firewalls are based on interrogating the values of selected packet control fields, the creator of the firewall rules must have an understanding of how TCP/IP works, what the different values in the packet control fields are and how these values are used in a normal session conversation. For a good explanation go to: . The Packet Filter Firewall As of July 2003 the OpenBSD firewall software application known as PF was ported to &os; 5.3. PF is a complete, fully featured firewall that contains ALTQ for bandwidth usage management in a way similar to the dummynet provides in IPFW. The OpenBSD project does an outstanding job of maintaining the PF users' guide that it will not be made part of this handbook firewall section as that would just be duplicated effort. For older 5.X version of &os; you can find PF in the &os; ports collection here: security/pf. More info can be found at the PF for &os; web site: . The OpenBSD PF user's guide is here: . PF in &os; 5.X is at the level of OpenBSD version 3.5. The port from the &os; ports collection at the level of OpenBSD version 3.4. Keep that in mind when browsing the user's guide. Enabling PF PF is included in the basic &os; install for versions newer than 5.3 as a separate run time loadable module. PF will dynamically load its kernel loadable module when the rc.conf statement pf_enable="YES" is used. The loadable module was created with &man.pflog.4; logging enabled. Kernel options It is not a mandatory requirement that you enable PF by compiling the following options into the &os; kernel. It is only presented here as background information. Compiling PF into the kernel causes the loadable module to never be used. Sample kernel config PF option statements are in the /usr/src/sys/conf/NOTES kernel source and are reproduced here: device pf device pflog device pfsync device pf tells the compile to include Packet Filter as part of its core kernel. device pflog enables the optional &man.pflog.4; pseudo network device which can be used to log traffic to a &man.bpf.4; descriptor. The &man.pflogd.8; daemon can be used to store the logging information to disk. device pfsync enables the optional &man.pfsync.4; pseudo network device that is used to monitor state changes. As this is not part of the loadable module one has to build a custom kernel to use it. These settings will take affect only after you have built and installed a kernel with them set. Available rc.conf Options You need the following statements in /etc/rc.conf to activate PF at boot time: pf_enable="YES" # Enable PF (load module if required) pf_rules="/etc/pf.conf" # rules definition file for pf pf_flags="" # additional flags for pfctl startup pflog_enable="YES" # start pflogd(8) pflog_logfile="/var/log/pflog" # where pflogd should store the logfile pflog_flags="" # additional flags for pflogd startup If you have a LAN behind this firewall and have to forward packets for the computers in the LAN or want to do NAT you have to enable the following option as well: gateway_enable="YES" # Enable as Lan gateway The IPFILTER (IPF) Firewall The author of IPFILTER is Darren Reed. IPFILTER is not operating system dependent. IPFILTER is a open source application and has been ported to &os;, NetBSD, OpenBSD, SunOS, HP/UX, and Solaris operating systems. IPFILTER is actively being supported and maintained, with updated versions being released regularly. IPFILTER is based on a kernel-side firewall and NAT mechanism that can be controlled and monitored by userland interface programs. The firewall rules can be set or deleted with the &man.ipf.8; utility. The NAT rules can be set or deleted with the &man.ipnat.1; utility. The &man.ipfstat.8; utility can print run-time statistics for the kernel parts of IPFILTER. The &man.ipmon.8; program can log IPFILTER actions to the system log files. IPF was originally written using a rule processing logic of the last matching rule wins and used only stateless type of rules. Over time IPF has been enhanced to include a quick option and a stateful keep state option which drastically modernized the rules processing logic. IPF's official documentation covers the legacy rule coding parameters and the legacy rule file processing logic. the modernized functions are only included as additional options, completely understating their benefits in producing a far superior secure firewall. The instructions contained in this section are based on using rules that contain the quick option and the stateful keep state option. This is the basic framework for coding an inclusive firewall rule set. An inclusive firewall only allows packets matching the rules to pass through. This way you can control what services can originate behind the firewall destine for the public Internet and also control the services which can originate from the public Internet accessing your private network. Everything else is blocked and logged by default design. Inclusive firewalls are much, much more secure than exclusive firewall rule sets and is the only rule set type covered here in. For detailed explanation of the legacy rules processing method see: and . The IPF FAQ is at . Enabling IPF IPF is included in the basic &os; install as a separate run time loadable module. IPF will dynamically load its kernel loadable module when the rc.conf statement ipfilter_enable="YES" is used. The loadable module was created with logging enabled and the default pass all options. You do not need to compile IPF into the &os; kernel just to change the default to block all , you can do that by just coding a block all rule at the end of your rule set. Kernel options It is not a mandatory requirement that you enable IPF by compiling the following options into the &os; kernel. It is only presented here as background information. Compiling IPF into the kernel causes the loadable module to never be used. Sample kernel config IPF option statements are in the /usr/src/sys/i386/conf/LINT kernel source and are reproduced here. options IPFILTER options IPFILTER_LOG options IPFILTER_DEFAULT_BLOCK options IPFILTER tells the compile to include IPFILTER as part of its core kernel. options IPFILTER_LOG enables the option to have IPF log traffic by writing to the ipl packet logging pseudo—device for every rule that has the log keyword. options IPFILTER_DEFAULT_BLOCK changes the default behavior so any packet not matching a firewall pass rule gets blocked. These settings will take affect only after you have built and installed a kernel with them set. Available rc.conf Options You need the following statements in /etc/rc.conf to activate IPF at boot time: ipfilter_enable="YES" # Start ipf firewall ipfilter_rules="/etc/ipf.rules" # loads rules definition text file ipmon_enable="YES" # Start IP monitor log ipmon_flags="-Ds" # D = start as daemon # s = log to syslog # v = log tcp window, ack, seq # n = map IP & port to names If you have a LAN behind this firewall that uses the reserved private IP address ranges, then you need to add the following to enable NAT function. gateway_enable="YES" # Enable as Lan gateway ipnat_enable="YES" # Start ipnat function ipnat_rules="/etc/ipnat.rules" # rules definition file for ipnat IPF The ipf command is used to load your rules file. Normally you create a file containing your custom rules and use this command to replace in mass the currently running firewall internal rules. ipf -Fa -f /etc/ipf.rules -Fa means flush all internal rules tables. -f means this is the file to read for the rules to load. This gives you the ability to make changes to their custom rules file, run the above IPF command thus updating the running firewall with a fresh copy of all the rules without having to reboot the system. This method is very convenient for testing new rules as the procedure can be executed as many times as needed. See the &man.ipf.8; man page for details on the other flags available with this command. The &man.ipf.8; command expects the rules file to be a standard text file. It will not accept a rules file written as a script with symbolic substitution. There is a way to build IPF rules that utilities the power of script symbolic substitution. See the Building Rule Script section. IPFSTAT The default behavior of &man.ipfstat.8; is to retrieve and display the totals of the accumulated statistics gathered as a result of applying the user coded rules against packets going in and out of the firewall since it was last started, or since the last time the accumulators were reset to zero by ipf -Z command. See the &man.ipfstat.8; manual page for details. The default &man.ipfstat.8; command output will look something like this: input packets: blocked 99286 passed 1255609 nomatch 14686 counted 0 output packets: blocked 4200 passed 1284345 nomatch 14687 counted 0 input packets logged: blocked 99286 passed 0 output packets logged: blocked 0 passed 0 packets logged: input 0 output 0 log failures: input 3898 output 0 fragment state(in): kept 0 lost 0 fragment state(out): kept 0 lost 0 packet state(in): kept 169364 lost 0 packet state(out): kept 431395 lost 0 ICMP replies: 0 TCP RSTs sent: 0 Result cache hits(in): 1215208 (out): 1098963 IN Pullups succeeded: 2 failed: 0 OUT Pullups succeeded: 0 failed: 0 Fastroute successes: 0 failures: 0 TCP cksum fails(in): 0 (out): 0 Packet log flags set: (0) When supplied with either -i for inbound or -o for outbound, it will retrieve and display the appropriate list of filter rules currently installed and in use by the kernel. ipfstat -in displays the inbound internal rules table with rule number. ipfstat -on displays the outbound internal rules table with the rule number. The output will look something like this: @1 pass out on xl0 from any to any @2 block out on dc0 from any to any @3 pass out quick on dc0 proto tcp/udp from any to any keep state ipfstat -ih displays the inbound internal rules table prefixed each rule with count of how many times the rule was matched. ipfstat -oh displays the outbound internal rules table prefixed each rule with count of how many times the rule was matched. The output will look something like this: 2451423 pass out on xl0 from any to any 354727 block out on dc0 from any to any 430918 pass out quick on dc0 proto tcp/udp from any to any keep state One of the most important functions of the ipfstat command is the -t flag which activates the display state table in a way similar to the way &man.top.1; shows the &os; running process table. When your firewall is under attack this function gives you the ability to identify, drill down to, and see the attacking packets. The optional sub-flags give the ability to select destination or source IP, port, protocol, you want to monitor in real time. See the &man.ipfstat.8 man page for details. IPMON In order for ipmon to properly work, the kernel option IPFILTER_LOG must be turned on. This command has 2 different modes it can be used in. Native mode is the default mode when you type the command on the command line without the -D flag. Daemon mode is for when you want to have a continuous system log file available so you can review logging of past events. This is how &os; and IPFILTER are configured to work together. &os; has a built in facility to automatically rotate syslogs. That is why outputting the log information to syslogd is better than the default of outputting to a regular file. In rc.conf file you see the ipmon_flags statement uses the "-Ds" flags ipmon_flags="-Ds" # D = start as daemon # s = log to syslog # v = log tcp window, ack, seq # n = map IP & port to names The benefits of logging are obvious. It provides the ability to review, after the fact, information like: what packets had been dropped, what addresses they came from and where they were going. These all give you a significant edge in tracking down attackers. Even with the logging facility enabled, IPF will not generate any rule logging on its own. The firewall administrator decides what rules in the rule set he wants to log and adds the log keyword to those rules. Normally only deny rules are logged. Its very customary to include a default deny everything rule with the log keyword included as your last rule in the rule set. This way you get to see all the packets that did not match any of the rules in the rule set. IPMON Logging Syslogd uses its own special method for segregation of log data. It uses special grouping called facility and level. IPMON in -Ds mode uses Local0 as the facility name. All IPMON logged data goes to Local0. The following levels can be used to further segregate the logged data if desired. LOG_INFO - packets logged using the "log" keyword as the action rather than pass or block. LOG_NOTICE - packets logged which are also passed LOG_WARNING - packets logged which are also blocked LOG_ERR - packets which have been logged and which can be considered short To setup IPFILTER to log all data to /var/log/ipfilter.log, you will need to create the file. The following command will do that: touch /var/log/ipfilter.log The syslog function is controlled by definition statements in the /etc/syslog.conf file. The syslog.conf file offers considerable flexibility in how syslog will deal with system messages issued by software applications like IPF. Add the following statement to /etc/syslog.conf : Local0.* /var/log/ipfilter.log The Local0.* means to write all the logged messages to the coded file location. To activate the changes to /etc/syslog.conf you can reboot or bump the syslog task into re-reading /etc/syslog.conf by kill -HUP <pid>. You get the pid (i.e. process number) by listing the tasks with the ps -ax command. Find syslog in the display and the pid is the number in the left column. Do not forget to change /etc/newsyslog.conf to rotate the new log you just created above. The Format of Logged Messages Messages generated by ipmon consist of data fields separated by white space. Fields common to all messages are: The date of packet receipt. The time of packet receipt. This is in the form HH:MM:SS.F, for hours, minutes, seconds, and fractions of a second (which can be several digits long). The name of the interface the packet was processed on, e.g. dc0. The group and rule number of the rule, e.g. @0:17. These can be viewed with ipfstat -in. The action: p for passed, b for blocked, S for a short packet, n did not match any rules, L for a log rule. The order of precedence in showing flags is: S, p, b, n, L. A capital P or B means that the packet has been logged due to a global logging setting, not a particular rule. The addresses. This is actually three fields: the source address and port (separated by a comma), the -> symbol, and the destination address and port. 209.53.17.22,80 -> 198.73.220.17,1722. PR followed by the protocol name or number, e.g. PR tcp. len followed by the header length and total length of the packet, e.g. len 20 40. If the packet is a TCP packet, there will be an additional field starting with a hyphen followed by letters corresponding to any flags that were set. See the &man.ipmon.8; manual page for a list of letters and their flags. If the packet is an ICMP packet, there will be two fields at the end, the first always being ICMP, and the next being the ICMP message and sub-message type, separated by a slash, e.g. ICMP 3/3 for a port unreachable message. Building the Rule Script Some experienced IPF users create a file containing the rules and code them in a manner compatible with running them as a script with symbolic substitution. The major benefit of doing this is you only have to change the value associated with the symbolic name and when the script is run all the rules containing the symbolic name will have the value substituted in the rules. Being a script, you can use symbolic substitution to code frequent used values and substitute them in multiple rules. You will see this in the following example. The script syntax used here is compatible with the sh, csh, and tcsh shells. Symbolic substitution fields are prefixed with a dollar sign $. Symbolic fields do not have the $ prefix The value to populate the Symbolic field must be enclosed with "double quotes". Start your rule file with something like this: ############# Start of IPF rules script ######################## oif="dc0" # name of the outbound interface odns="192.0.2.11" # ISP's dns server IP address Symbolic> myip="192.0.2.7" # My Static IP address from ISP ks="keep state" fks="flags S keep state" # You can use this same to build the /etc/ipf.rules file #cat >> /etc/ipf.rules << EOF # exec ipf command and read inline data, stop reading # when word EOF is found. There has to be one line # after the EOF line to work correctly. /sbin/ipf -Fa -f - << EOF # Allow out access to my ISP's Domain name server. pass out quick on $oif proto tcp from any to $odns port = 53 $fks pass out quick on $oif proto udp from any to $odns port = 53 $ks # Allow out non-secure standard www function pass out quick on $oif proto tcp from $myip to any port = 80 $fks # Allow out secure www function https over TLS SSL pass out quick on $oif proto tcp from $myip to any port = 443 $fks EOF ################## End of IPF rules script ######################## That is all there is to it. The rules are not important in this example, how the Symbolic substitution field are populated and used are. If the above example was in /etc/ipf.rules.script file, you could reload these rules by entering on the command line. sh /etc/ipf.rules.script There is one problem with using a rules file with embedded symbolics. IPF has no problem with it, but the rc startup scripts that read rc.conf will have problems. To get around this limitation with a rc scripts, remove the following line: ipfilter_rules= Add a script like the following to your /usr/local/etc/rc.d/ startup directory. The script should have a obvious name like loadipfrules.sh . The .sh extension is mandatory. #!/bin/sh sh /etc/ipf.rules.script The permission on this script file must be read, write, exec for owner root. chmod 700 /usr/local/etc/rc.d/ipf.loadrules.sh Now when you system boots your IPF rules will be loaded using the script. IPF Rule Sets A rule set is a group of ipf rules coded to pass or block packets based on the values contained in the packet. The bi-directional exchange of packets between hosts comprises a session conversation. The firewall rule set processes the packet 2 times, once on its arrival from the public Internet host and again as it leaves for its return trip back to the public Internet host. Each tcp/ip service (i.e. telnet, www, mail, etc.) is predefined by its protocol, source and destination IP address, or the source and destination port number. This is the basic selection criteria used to create rules which will pass or block services. IPF was originally written using a rules processing logic of 'the last matching rule wins' and used only stateless rules. Over time IPF has been enhanced to include a 'quick' option and a stateful 'keep state' option which drastically modernized the rules processing logic. The instructions contained in this section is based on using rules that contain the 'quick' option. and the stateful 'keep state' option. This is the basic framework for coding an inclusive firewall rule set. An inclusive firewall only allows services matching the rules through. This way you can control what services can originate behind the firewall destined for the public Internet and also control the services which can originate from the public Internet accessing your private network. Everything else is blocked and logged by default design. Inclusive firewalls are much, much securer than exclusive firewall rule sets and is the only rule set type covered herein. Warning, when working with the firewall rules, always, always do it from the root console of the system running the firewall or you can end up locking your self out. Rule Syntax The rule syntax presented here has been simplified to only address the modern stateful rule context and 'first matching rule wins' logic. For the complete legacy rule syntax description see the online ipf man page at &man.ipf.8 # is used to mark the start of a comment and may appear at the end of a rule line or on its own lines. Blank lines are ignored. Rules contain keywords, These keywords have to be coded in a specific order from left to right on the line. Keywords are identified in bold type. Some keywords have sub-options which may be keywords them selves and also include more sub-options. Each of the headings in the below syntax has a bold section header which expands on the content. ACTION IN-OUT OPTIONS SELECTION STATEFUL PROTO SRC_ADDR,DST_ADDR OBJECT PORT_NUM TCP_FLAG STATEFUL ACTION = block | pass IN-OUT = in | out OPTIONS = log | quick | on interface-name SELECTION = proto value | source/destination IP | port = number | flags flag-value PROTO = tcp/udp | udp | tcp | icmp SRC_ADD,DST_ADDR = all | from object to object OBJECT = IP address | any PORT_NUM = port number TCP_FLAG = S STATEFUL = keep state ACTION The action indicates what to do with the packet if it matches the rest of the filter rule. Each rule must have a action. The following actions are recognized: block indicates that the packet should be dropped if the selection parameters match the packet. pass indicates that the packet should exit the firewall if the selection parameters match the packet. IN-OUT This is a mandatory requirement that each filter rule explicitly state which side of the I/O it is to be used on. The next keyword must be either in or out and one or the other has to be coded or the rule will not pass syntax check. in means this rule is being applied against an inbound packet which has just been received on the interface facing the public Internet. out means this rule is being applied against an outbound packet destined for the interface facing the public Internet. OPTIONS These options must be used in the order shown here. log indicates that the packet header will be written to the ipl log (as described in the LOGGING section below) if the selection parameters match the packet. quick indicates that if the selection parameters match the packet, this rule will be the last rule checked, allowing a "short-circuit" path to avoid processing any following rules for this packet. This option is a mandatory requirement for the modernized rules processing logic. on indicates the interface name to be incorporated into the selection parameters. Interface names are as displayed by ifconfig. Using this option, the rule will only match if the packet is going through that interface in the specified direction (in/out). This option is a mandatory requirement for the modernized rules processing logic. When a packet is logged, the headers of the packet are written to the IPL packet logging pseudo-device. Immediately following the log keyword, the following qualifiers may be used (in this order): body indicates that the first 128 bytes of the packet contents will be logged after the headers. first If the 'log' keyword is being used in conjunction with a "keep state" option, it is recommended that this option is also applied so that only the triggering packet is logged and not every packet which there after matches the 'keep state' information. SELECTION The keywords described in this section are used to describe attributes of the packet to be interrogated when determining whether rules match or don't match. There is a keyword subject, and it has sub-option keywords, one of which has to be selected. The following general-purpose attributes are provided for matching, and must be used in this order: PROTO Proto is the subject keyword, it must be coded along with one of it.s corresponding keyword sub-option values. The value allows a specific protocol to be matched against. This option is a mandatory requirement for the modernized rules processing logic. tcp/udp | udp | tcp | icmp or any protocol names found in /etc/protocols are recognized and may be used. The special protocol keyword tcp/udp may be used to match either a TCP or a UDP packet, and has been added as a convenience to save duplication of otherwise identical rules. SRC_ADDR/DST_ADDR The 'all' keyword is essentially a synonym for "from any to any" with no other match parameters. from src to dst The from and to keywords are used to match against IP addresses. Rules must specify BOTH source and destination parameters. .any. is a special keyword that matches any IP address. As in 'from any to any' or 'from 0.0.0.0/0 to any' or 'from any to 0.0.0.0/0' or 'from 0.0.0.0 to any' or 'from any to 0.0.0.0' IP addresses may be specified as a dotted IP address numeric form/mask-length, or as single dotted IP address numeric form. There isn't a way to match ranges of IP addresses which do not express themselves easily as mask-length. See this link for help on writing mask-length: PORT If a port match is included, for either or both of source and destination, then it is only applied to TCP and UDP packets. When composing port comparisons, either the service name from /etc/services or an integer port number may be used. When the port appears as part of the from object, it matches the source port number, when it appears as part of the to object, it matches the destination port number. The use of the port option with the .to. object is a mandatory requirement for the modernized rules processing logic. As in 'from any to any port = 80' Port comparisons may be done in a number of forms, with a number of comparison operators, or port ranges may be specified. port "=" | "!=" | "<" | ">" | "<=" | ">=" | "eq" | "ne" | "lt" | "gt" | "le" | "ge". To specify port ranges, port "<>" | "><" Following the source and destination matching parameters, the following two parameters are mandatory requirements for the modernized rules processing logic. <acronym>TCP</acronym>_FLAG Flags are only effective for TCP filtering. The letters represents one of the possible flags that can be interrogated in the TCP packet header. The modernized rules processing logic uses the 'flags S' parameter to identify the tcp session start request. STATEFUL 'keep state' indicates that on a pass rule, any packets that match the rules selection parameters is to activate the stateful filtering facility. This option is a mandatory requirement for the modernized rules processing logic. Stateful Filtering Stateful filtering treats traffic as a bi-directional exchange of packets comprising a session conversation. When activated keep-state dynamically generates internal rules for each anticipated packet being exchanged during the bi-directional session conversation. It has the interrogation abilities to determine if the session conversation between the originating sender and the destination are following the valid procedure of bi-directional packet exchange. Any packets that do not properly fit the session conversation template are automatically rejected as impostors. Keep state will also allow ICMP packets related to a TCP or UDP session through. So if you get ICMP type 3 code 4 in response to some web surfing allowed out by a keep state rule, they will be automatically allowed in. Any packet that IPF can be certain is part of a active session, even if it is a different protocol, will be let in. What happens is: Packets destined to go out the interface connected to the public Internet are first checked against the dynamic state table, if the packet matches the next expected packet comprising in a active session conversation, then it exits the firewall and the state of the session conversation flow is updated in the dynamic state table, the remaining packets get checked against the outbound rule set. Packets coming in to the interface connected to the public Internet are first checked against the dynamic state table, if the packet matches the next expected packet comprising a active session conversation, then it exits the firewall and the state of the session conversation flow is updated in the dynamic state table, the remaining packets get checked against the inbound rule set. When the conversation completes it is removed from the dynamic state table. Stateful filtering allows you to focus on blocking/passing new sessions. If the new session is passed, all its subsequent packets will be allowed through automatically and any impostors automatically rejected. If a new session is blocked, none of its subsequent packets will be allowed through. Stateful filtering has technically advanced interrogation abilities capable of defending against the flood of different attack methods currently employed by attackers. Inclusive Rule set Example The following rule set is an example of how to code a very secure inclusive type of firewall. An inclusive firewall only allows services matching pass rules through and blocks all other by default. All firewalls have at the minimum two interfaces which have to have rules to allow the firewall to function. All Unix flavored systems including &os; are designed to use interface l0 and IP address 127.0.0.1 for internal communication with in the &os; operating system. The firewall rules must contain rules to allow free unmolested movement of these special internally used packets. The interface which faces the public Internet, is the one which you code your rules to authorize and control access out to the public Internet and access requests arriving from the public Internet. This can be your .user ppp. tun0 interface or your NIC card that is cabled to your DSL or cable modem. In cases where one or more than one NICs are cabled to Private LANs (local area networks) behind the firewall, those interfaces must have a rule coded to allow free unmolested movement of packets originating from those LAN interfaces. The rules should be first organized into three major sections, all the free unmolested interfaces, public interface outbound, and the public interface inbound. The order of the rules in each of the public interface sections should be in order of the most used rules being placed before less often used rules with the last rule in the section being a block log all packets on that interface and direction. The Outbound section in the following rule set only contains 'pass' rules which contain selection values that uniquely identify the service that is authorized for public Internet access. All the rules have the 'quick', 'on', 'proto', 'port', and 'keep state' option coded. The 'proto tcp' rules have the 'flag' option included to identify the session start request as the triggering packet to activate the stateful facility. The Inbound section has all the blocking of undesirable packets first for two different reasons. First is these things being blocked may be part of an otherwise valid packet which may be allowed in by the later authorized service rules. Second reason is that by having a rule that explicitly blocks selected packets that I receive on an infrequent bases and don't want to see in the log, this keeps them from being caught by the last rule in the section which blocks and logs all packets which have fallen through the rules. The last rule in the section which blocks and logs all packets is how you create the legal evidence needed to prosecute the people who are attacking your system. Another thing you should take note of, is there is no response returned for any of the undesirable stuff, their packets just get dropped and vanish. This way the attackers has no knowledge if his packets have reached your system. The less the attackers can learn about your system the more secure it is. The inbound 'nmap OS fingerprint' attempts rule I log the first occurrence because this is something a attacker would do. Any time you see log messages on a rule with .log first. you should do an ipstat -h command to see the number of times the rule has been matched so you know if your are being flooded, i.e. under attack. When you log packets with port numbers you do not recognize, go to and do a port number lookup to find what the purpose of that port number is. Check out this link for port numbers used by Trojans The following rule set is a complete very secure 'inclusive' type of firewall rule set that I have used on my system. You can not go wrong using this rule set for your own. Just comment out any pass rules for services to don.t want to authorize. If you see messages in your log that you want to stop seeing just add a block rule in the inbound section. You have to change the dc0 interface name in every rule to the interface name of the Nic card that connects your system to the public Internet. For user PPP it would be tun0. Add the following statements to /etc/ipf.rules: ################################################################# # No restrictions on Inside Lan Interface for private network # Not needed unless you have Lan ################################################################# #pass out quick on xl0 all #pass in quick on xl0 all ################################################################# # No restrictions on Loopback Interface ################################################################# pass in quick on lo0 all pass out quick on lo0 all ################################################################# # Interface facing Public Internet (Outbound Section) # Interrogate session start requests originating from behind the # firewall on the private network # or from this gateway server destine for the public Internet. ################################################################# # Allow out access to my ISP's Domain name server. # xxx must be the IP address of your ISP.s DNS. # Dup these lines if your ISP has more than one DNS server # Get the IP addresses from /etc/resolv.conf file pass out quick on dc0 proto tcp from any to xxx port = 53 flags S keep state pass out quick on dc0 proto udp from any to xxx port = 53 keep state # Allow out access to my ISP's DHCP server for cable or DSL networks. # This rule is not needed for .user ppp. type connection to the # public Internet, so you can delete this whole group. # Use the following rule and check log for IP address. # Then put IP address in commented out rule & delete first rule pass out log quick on dc0 proto udp from any to any port = 67 keep state #pass out quick on dc0 proto udp from any to z.z.z.z port = 67 keep state # Allow out non-secure standard www function pass out quick on dc0 proto tcp from any to any port = 80 flags S keep state # Allow out secure www function https over TLS SSL pass out quick on dc0 proto tcp from any to any port = 443 flags S keep state # Allow out send & get email function pass out quick on dc0 proto tcp from any to any port = 110 flags S keep state pass out quick on dc0 proto tcp from any to any port = 25 flags S keep state # Allow out Time pass out quick on dc0 proto tcp from any to any port = 37 flags S keep state # Allow out nntp news pass out quick on dc0 proto tcp from any to any port = 119 flags S keep state # Allow out gateway & LAN users non-secure FTP ( both passive & active modes) # This function uses the IPNAT built in FTP proxy function coded in # the nat rules file to make this single rule function correctly. # If you want to use the pkg_add command to install application packages # on your gateway system you need this rule. pass out quick on dc0 proto tcp from any to any port = 21 flags S keep state # Allow out secure FTP, Telnet, and SCP # This function is using SSH (secure shell) pass out quick on dc0 proto tcp from any to any port = 22 flags S keep state # Allow out non-secure Telnet pass out quick on dc0 proto tcp from any to any port = 23 flags S keep state # Allow out FBSD CVSUP function pass out quick on dc0 proto tcp from any to any port = 5999 flags S keep state # Allow out ping to public Internet pass out quick on dc0 proto icmp from any to any icmp-type 8 keep state # Allow out whois for LAN PC to public Internet pass out quick on dc0 proto tcp from any to any port = 43 flags S keep state # Block and log only the first occurrence of everything # else that.s trying to get out. # This rule enforces the block all by default logic. block out log first quick on dc0 all ################################################################# # Interface facing Public Internet (Inbound Section) # Interrogate packets originating from the public Internet # destine for this gateway server or the private network. ################################################################# # Block all inbound traffic from non-routable or reserved address spaces block in quick on dc0 from 192.168.0.0/16 to any #RFC 1918 private IP block in quick on dc0 from 172.16.0.0/12 to any #RFC 1918 private IP block in quick on dc0 from 10.0.0.0/8 to any #RFC 1918 private IP block in quick on dc0 from 127.0.0.0/8 to any #loopback block in quick on dc0 from 0.0.0.0/8 to any #loopback block in quick on dc0 from 169.254.0.0/16 to any #DHCP auto-config block in quick on dc0 from 192.0.2.0/24 to any #reserved for docs block in quick on dc0 from 204.152.64.0/23 to any #Sun cluster interconnect block in quick on dc0 from 224.0.0.0/3 to any #Class D & E multicast ##### Block a bunch of different nasty things. ############ # That I don't want to see in the log # Block frags block in quick on dc0 all with frags # Block short tcp packets block in quick on dc0 proto tcp all with short # block source routed packets block in quick on dc0 all with opt lsrr block in quick on dc0 all with opt ssrr # Block nmap OS fingerprint attempts # Log first occurrence of these so I can get their IP address block in log first quick on dc0 proto tcp from any to any flags FUP # Block anything with special options block in quick on dc0 all with ipopts # Block public pings block in quick on dc0 proto icmp all icmp-type 8 # Block ident block in quick on dc0 proto tcp from any to any port = 113 # Block all Netbios service. 137=name, 138=datagram, 139=session # Netbios is MS/Windows sharing services. # Block MS/Windows hosts2 name server requests 81 block in log first quick on dc0 proto tcp/udp from any to any port = 137 block in log first quick on dc0 proto tcp/udp from any to any port = 138 block in log first quick on dc0 proto tcp/udp from any to any port = 139 block in log first quick on dc0 proto tcp/udp from any to any port = 81 # Allow traffic in from ISP's DHCP server. This rule must contain # the IP address of your ISP.s DHCP server as it.s the only # authorized source to send this packet type. Only necessary for # cable or DSL configurations. This rule is not needed for # .user ppp. type connection to the public Internet. # This is the same IP address you captured and # used in the outbound section. pass in quick on dc0 proto udp from z.z.z.z to any port = 68 keep state # Allow in standard www function because I have apache server pass in quick on dc0 proto tcp from any to any port = 80 flags S keep state # Allow in non-secure Telnet session from public Internet # labeled non-secure because ID/PW passed over public Internet as clear text. # Delete this sample group if you do not have telnet server enabled. #pass in quick on dc0 proto tcp from any to any port = 23 flags S keep state # Allow in secure FTP, Telnet, and SCP from public Internet # This function is using SSH (secure shell) pass in quick on dc0 proto tcp from any to any port = 22 flags S keep state # Block and log only first occurrence of all remaining traffic # coming into the firewall. The logging of only the first # occurrence stops a .denial of service. attack targeted # at filling up your log file space. # This rule enforces the block all by default logic. block in log first quick on dc0 all ################### End of rules file ##################################### <acronym>NAT</acronym> NAT stands for Network Address Translation. To those familiar with Linux, this concept is called IP Masquerading, NAT and IP Masquerading are the same thing. One of the many things the IPF NAT function enables, is the ability to have a private Local Area Network (LAN) behind the firewall sharing a single ISP assigned IP address to the public Internet. You ask why would someone want to do this. ISPs normally assign a dynamic IP address to their non-commercial users. Dynamic means the IP address can be different each time you dial in and logon to your ISP, or for cable and DSL modem users when you power off and then power on your modems you can get assigned a different IP address. This IP address is how you are known to the public Internet. Now lets say you have 5 PCs at home and each one needs Internet access. You would have to pay your ISP for an individual Internet account for each PC and have 5 phone lines. With NAT you only need a single account with your ISP, then cable your other 4 PC.s to a switch and the switch to the NIC in your &os; system which is going to service your LAN as a gateway. NAT will automatically translate the private LAN IP address for each separate PC on the LAN to the single public IP address as it exits the firewall bound for the public Internet. It also does the reverse translation for returning packets. NAT is most often accomplished without the approval, or knowledge, of your ISP and in most cases is grounds for your ISP terminating your account if found out. Commercial users pay a lot more for their Internet connection and usually get assigned a block of static IP address which never change. The ISP also expects and consents to their Commercial customers using NAT for their internal private LANs. There is a special range of IP addresses reserved for NATed private LAN IP address. According to RFC 1918, you can use the following IP ranges for private nets which will never be routed directly to the public Internet. Start IP 10.0.0.0 - Ending IP 10.255.255.255 Start IP 172.16.0.0 - Ending IP 172.31.255.255 Start IP 192.168.0.0 - Ending IP 192.168.255.255 IP<acronym>NAT</acronym> NAT rules are loaded by using the ipnat command. Typically the NAT rules are stored in /etc/ipnat.rules . See &man.ipnat.1 for details. When changing the NAT rules after NAT has been started, Make your changes to the file containing the nat rules, then run ipnat command with the -CF flags to delete the internal in use NAT rules and flush the contents of the translation table of all active entries. To reload the NAT rules issue a command like this: ipnat -CF -f /etc/ipnat.rules To display some statistics about your NAT, use this command: ipnat -s To list the NAT table's current mappings, use this command: ipnat -l To turn verbose mode on, and display information relating to rule processing and active rules/table entries: ipnat -v IP<acronym>NAT</acronym> Rules NAT rules are very flexible and can accomplish many different things to fit the needs of commercial and home users. The rule syntax presented here has been simplified to what is most commonly used in a non-commercial environment. For a complete rule syntax description see the man ipf page at &man.ipnat.5;. The syntax for a NAT rule looks something like this: map IF LAN_IP_RANGE -> PUBLIC_ADDRESS The keyword `map' starts the rule. Replace IF with the external interface. The LAN_IP_RANGE is what your internal clients use for IP Addressing, usually this is something like 192.168.1.0/24. The PUBLIC_ADDRESS can either be the external IP address or the special keyword `0.32', which means to use the IP address assigned to IF. How <acronym>NAT</acronym> works A packet arrives at the firewall from the LAN with a public destination. It passes through the outbound filter rules, NAT gets his turn at the packet and applies its rules top down, first matching rule wins. NAT tests each of its rules against the packets interface name and source IP address. When a packets interface name matches a NAT rule then the [source IP address, i.e. private Lan IP address] of the packet is checked to see if it falls within the IP address range specified to the left of the arrow symbol on the NAT rule. On a match the packet has its source IP address rewritten with the public IP address obtained by the `0.32' keyword. NAT posts a entry in its internal NAT table so when the packet returns from the public Internet it can be mapped back to its original private IP address and then passed to the filter rules for processing. Enabling IP<acronym>NAT</acronym> To enable IPNAT add these statements to /etc/rc.conf To enable your machine to route traffic between interfaces. gateway_enable="YES" To start IPNAT automatically each time: ipnat_enable="YES" To specify where to load the IPNAT rules from ipnat_rules="/etc/ipnat.rules" <acronym>NAT</acronym> for a very large LAN For networks that have large numbers of PC's on the Lan or networks with more that a single LAN the process of funneling all those private IP address into a single public IP address becomes a resource problem that may cause problems with same port numbers being used many times across many NATed LAN PC's causing collisions. There are 2 ways to relieve this resource problem. Assigning Ports to Use BLAH map dc0 192.168.1.0/24 -> 0.32 In the above rule the packet's source port is unchanged as the packet passes through IPNAT. By adding the portmap keyword you can tell IPNAT to only use source ports in a range. For example the following rule will tell IPNAT to modify the source port to be within that range. map dc0 192.168.1.0/24 -> 0.32 portmap tcp/udp 20000:60000 Additionally we can make things even easier by using the `auto' keyword to tell IPNAT to determine by itself which ports are available to use: map dc0 192.168.1.0/24 -> 0.32 portmap tcp/udp auto Using a pool of public addresses In very large LANs there comes a point where there are just too many LAN addresses to fit into a single public address. By changing the following rule: map dc0 192.168.1.0/24 -> 204.134.75.1 Currently this rule maps all connections through 204.134.75.1. This can be changed to specify a range: map dc0 192.168.1.0/24 -> 204.134.75.1-10 Or a subnet using CIDR notation such as: map dc0 192.168.1.0/24 -> 204.134.75.0/24 Port Redirection An very common practice is to have a web server, email server, database server and DNS sever each segregated to a different PC on the LAN. In this case the traffic from these servers still have to be NATed, but there has to be some way to direct the inbound traffic to the correct LAN PC's. IPNAT has the redirection facilities of NAT to solve this problem. Lets say you have your web server on LAN address 10.0.10.25 and your single public IP address is 20.20.20.5 you would code the rule like this: map dc0 20.20.20.5/32 port 80 -> 10.0.10.25 port 80 or map dc0 0/32 port 80 -> 10.0.10.25 port 80 or for a LAN DNS Server on LAN address of 10.0.10.33 that needs to receive public DNS requests map dc0 20.20.20.5/32 port 53 -> 10.0.10.33 port 53 udp FTP and <acronym>NAT</acronym> FTP is a dinosaur left over from the time before the Internet as it is know today, when research universities were leased lined together and FTP was used to share files among research Scientists. This was a time when data security was not even an idea yet. Over the years the FTP protocol became buried into the backbone of the emerging Internet and its username and password being sent in clear text was never changed to address new security concerns. FTP has two flavors, it can run in active mode or passive mode. The difference is in how the data channel is acquired. Passive mode is more secure as the data channel is acquired be the ordinal ftp session requester. For a real good explanation of FTP and the different modes see IP<acronym>NAT</acronym> Rules IPNAT has a special built in FTP proxy option which can be specified on the NAT map rule. It can monitor all outbound packet traffic for FTP active or passive start session requests and dynamically create temporary filter rules containing only the port number really in use for the data channel. This eliminates the security risk FTP normally exposes the firewall to from having large ranges of high order port numbers open. This rule will handle all the traffic for the internal LAN: map dc0 10.0.10.0/29 -> 0/32 proxy port 21 ftp/tcp This rule handles the FTP traffic from the gateway. map dc0 0.0.0.0/0 -> 0/32 proxy port 21 ftp/tcp This rule handles all non-FTP traffic from the internal LAN. map dc0 10.0.10.0/29 -> 0/32 The FTP map rule goes before our regular map rule. All packets are tested against the first rule from the top. Matches on interface name, then private LAN source IP address, and then is it a FTP packet. If all that matches then the special FTP proxy creates temp filter rules to let the FTP session packets pass in and out, in addition to also NATing the FTP packets. All LAN packets that are not FTP do not match the first rule and fall through to the third rule and are tested, matching on interface and source IP, then are NATed. IP<acronym>NAT</acronym> FTP Filter Rules Only one filter rule is needed for FTP if the NAT FTP proxy is used. Without the FTP Proxy you will need the following three rules # Allow out LAN PC client FTP to public Internet # Active and passive modes pass out quick on rl0 proto tcp from any to any port = 21 flags S keep state # Allow out passive mode data channel high order port numbers pass out quick on rl0 proto tcp from any to any port > 1024 flags S keep state # Active mode let data channel in from FTP server pass in quick on rl0 proto tcp from any to any port = 20 flags S keep state FTP <acronym>NAT</acronym> Proxy Bug As of &os; 4.9 which includes IPFILTER version 3.4.31 the FTP proxy works as documented during the FTP session until the session is told to close. When the close happens packets returning from the remote FTP server are blocked and logged coming in on port 21. The NAT FTP/proxy appears to remove its temp rules prematurely, before receiving the response from the remote FTP server acknowledging the close. Posted problem report to ipf mailing list. Solution is to add filter rule like this one to get rid of these unwanted log messages or do nothing and ignore FTP inbound error messages in your log. Not like you do FTP session to the public Internet all the time, so this is not a big deal. Block in quick on rl0 proto tcp from any to any port = 21 IPFW The IPFIREWALL (IPFW) is a &os; sponsored firewall software application authored and maintained by &os; volunteer staff members. It uses the legacy Stateless rules and a legacy rule coding technique to achieve what is referred to as Simple Stateful logic. The IPFW stateless rule syntax is empowered with technically sophisticated selection capabilities which far surpasses the knowledge level of the customary firewall installer. IPFW is targeted at the professional user or the advanced technical computer hobbyist who have advanced packet selection requirements. A high degree of detailed knowledge into how different protocols use and create their unique packet header information is necessary before the power of the IPFW rules can be unleashed. Providing that level of explanation is out of the scope of this section of the handbook. IPFW is composed of 7 components, the primary component is the kernel firewall filter rule processor and its integrated packet accounting facility, the logging facility, the 'divert' rule which triggers the NAT facility, and the advanced special purpose facilities, the dummynet traffic shaper facilities, the 'fwd rule' forward facility, the bridge facility, and the ipstealth facility. Enabling IPFW IPFW is included in the basic &os; install as a separate run time loadable module. IPFW will dynamically load the kernel module when the rc.conf statement firewall_enable="YES" is used. You do not need to compile IPFW into the &os; kernel unless you want NAT function enabled. After rebooting your system with firewall_enable="YES" in rc.conf the following white highlighted message is displayed on the screen as part of the boot process: IP packet filtering initialized, divert disabled, rule-based forwarding enabled, default to deny, logging disabled You can disregard this message as it is out dated and no longer is the true status of the IPFW loadable module. The loadable module really does have logging ability compiled in. To set the verbose logging limit, There is a knob you can set in /etc/sysctl.conf by adding this statement, logging will be enabled on future reboots. net.inet.ip.fw.verbose_limit=5 Kernel Options It is not a mandatory requirement that you enable IPFW by compiling the following options into the &os; kernel unless you need NAT function. It is presented here as background information. options IPFIREWALL This option enables IPFW as part of the kernel options IPFIREWALL_VERBOSE Enables logging of packets that pass through IPFW and have the 'log' keyword specified in the rule set. options IPFIREWALL_VERBOSE_LIMIT=5 This specifies the default number of packets from a particular rule is to be logged. Without this option, each repeated occurrences of the same packet will be logged, and eventually consuming all the free disk space resulting in services being denied do to lack of resources. The 5 is the number of consecutive times to log evidence of this unique occurrence. options IPFIREWALL_DEFAULT_TO_ACCEPT This option will allow everything to pass through the firewall by default. Which is a good idea when you are first setting up your firewall. options IPV6FIREWALL options IPV6FIREWALL_VERBOSE options IPV6FIREWALL_VERBOSE_LIMIT options IPV6FIREWALL_DEFAULT_TO_ACCEPT These options are exactly the same as the IPv4 options but they are for IPv6. If you don't use IPv6 you might want to use IPV6FIREWALL without any rules to block all IPv6 options IPDIVERT This enables the use of NAT functionality. If you don't include IPFIREWALL_DEFAULT_TO_ACCEPT or set your rules to allow incoming packets you will block all packets going to and from this machine. <filename>/etc/rc.conf</filename> Options If you don't have IPFW compliled into your kernel you will need to load it with the following statement in your /etc/rc.conf: firewall_enable="YES" Set the script to run to activate your rules: firewall_script="/etc/ipfw.rules" Enable logging: firewall_logging="YES" The IPFW Command The ipfw command is the normal vehicle for making manual single rule additions or deletions to the firewall active internal rules while it is running. The problem with using this method is once your system is shutdown or halted all the rules you added or changed or deleted are lost. Writing all your rules in a file and using that file to load the rules at boot time, or to replace in mass the currently running firewall rules with changes you made to the files content is the recommended method used here. The IPFW command is still a very useful to display the running firewall rules to the console screen. The IPFW accounting facility dynamically creates a counter for each rule that counts each packet that matches the rule. During the process of testing a rule, listing the rule with its counter is the only way of determining if the rule is functioning. To list all the rules in sequence: ipfw list To list all the rules with a time stamp of when the last time the rule was matched: ipfw -t list To list the accounting information, packet count for matched rules along with the rules themselves. The first column is the rule number, followed by the number of outgoing matched packets, followed by the number of incoming matched packets, and then the rule itself. ipfw -a list List the dynamic rules in addition to the static rules: ipfw -d list Also show the expired dynamic rules: ipfw -d -e list Zero the counters: ipfw zero Zero the counters for just rule NUM : ipfw zero NUM IPFW Rule Sets A rule set is a group of ipfw rules coded to allow or deny packets based on the values contained in the packet. The bi-directional exchange of packets between hosts comprises a session conversation. The firewall rule set processes the packet 2 times, once on its arrival from the public Internet host and again as it leaves for its return trip back to the public Internet host. Each tcp/ip service (i.e. telnet, www, mail, etc.) is predefined by its protocol, and port number. This is the basic selection criteria used to create rules which will allow or deny services. When a packet enters the firewall it is compared against the first rule in the rule set and progress one rule at a time moving from top to bottom of the set in ascending rule number sequence order. When the packet matches a rule selection parameters, the rules action field value is executed and the search of the rule set terminates for that packet. This is referred to as the 'first match wins' search method. If the packet does not match any of the rules, it gets caught by the mandatory ipfw default rule, number 65535 which denies all packets and discards them without any reply back to the originating destination. The instructions contained here are based on using rules that contain the stateful 'keep state', 'limit', 'in'/'out', and via options. This is the basic framework for coding an inclusive type firewall rule set. An inclusive firewall only allows services matching the rules through. This way you can control what services can originate behind the firewall destine for the public Internet and also control the services which can originate from the public Internet accessing your private network. Everything else is denied by default design. Inclusive firewalls are much, much more secure than exclusive firewall rule sets and is the only rule set type covered here in. When working with the firewall rules be careful, you can end up locking your self out. Rule Syntax The rule syntax presented here has been simplified to what is necessary to create a standard inclusive type firewall rule set. For a complete rule syntax description see the online &man.ipfw.8; man page. Rules contain keywords, These keywords have to be coded in a specific order from left to right on the line. Keywords are identified in bold type. Some keywords have sub-options which may be keywords them selves and also include more sub-options. # is used to mark the start of a comment and may appear at the end of a rule line or on its own lines. Blank lines are ignored. CMD RULE# ACTION LOGGING SELECTION STATEFUL CMD Each rule has to be prefixed with 'add' to add the rule to the internal table. RULE# Each rule has to have a rule number to go with it. ACTION A rule can be associated with one of the following actions, which will be executed when the packet matches the selection criterion of the rule. allow | accept | pass | permit These all mean the same thing which is to allow packets that match the rule to exit the firewall rule processing. The search terminates at this rule. check-state Checks the packet against the dynamic rules table. If a match is found, execute the action associated with the rule which generated this dynamic rule, otherwise move to the next rule. The Check-state rule does not have selection criterion. If no check-state rule is present in the rule set, the dynamic rules table is checked at the first keep-state or limit rule. deny | drop Both words mean the same thing which is to discard packets that match this rule. The search terminates. Logging log or logamount When a packet matches a rule with the log keyword, a message will be logged to syslogd with a facility name of SECURITY. The logging only occurs if the number of packets logged so far for that particular rule does not exceed the logamount parameter. If no logamount is specified, the limit is taken from the sysctl variable net.inet.ip.fw.verbose_limit. In both cases, a value of zero removes the logging limit. Once the limit is reached, logging can be re-enabled by clearing the logging counter or the packet counter for that rule, see the ipfw reset log command. Note: logging is done after all other packet matching conditions have been successfully verified, and before performing the final action (accept, deny) on the packet. It is up to you to decide which rules you want to enable logging on. Selection The keywords described in this section are used to describe attributes of the packet to be interrogated when determining whether rules match or don't match the packet. The following general-purpose attributes are provided for matching, and must be used in this order: udp | tcp | icmp or any protocol names found in /etc/protocols are recognized and may be used. The value specified is protocol to be matched against. This is a mandatory requirement. from src to dst The from and to keywords are used to match against IP addresses. Rules must specify BOTH source and destination parameters. any is a special keyword that matches any IP address. me is a special keyword that matches any IP address configured on an interface in your &os; system to represent the PC the firewall is running on. (i.e. this box) As in from me to any or from any to me or from 0.0.0.0/0 to any or from any to 0.0.0.0/0 or from 0.0.0.0 to any or from any to 0.0.0.0 or from me to 0.0.0.0. IP addresses are specified as a dotted IP address numeric form/mask-length, or as single dotted IP address numeric form. This is a mandatory requirement. See this link for help on writing mask-lengths. port number For protocols which support port numbers (such as TCP and UDP). It is mandatory that you code the port number of the service you want to match on. Service names (from /etc/services) may be used instead of numeric port values. in | out Matches incoming or outgoing packets, respectively. The in and out are keywords and it is mandatory that you code one or the other as part of your rule matching criterion. via IF Matches packets going through the interface specified by exact name. The via keyword causes the interface to always be checked as part of the match process. setup This is a mandatory keyword that identifies the session start request for TCP packets. keep-state This is a mandatory> keyword. Upon a match, the firewall will create a dynamic rule, whose default behavior is to match bidirectional traffic between source and destination IP/port using the same protocol. limit {src-addr | src-port | dst-addr | dst-port} The firewall will only allow N connections with the same set of parameters as specified in the rule. One or more of source and destination addresses and ports can be specified. The 'limit' and 'keep-state' can not be used on same rule. Limit provides the same stateful function as 'keep-state' plus its own functions. Stateful Rule Option Stateful filtering treats traffic as a bi-directional exchange of packets comprising a session conversation. It has the interrogation abilities to determine if the session conversation between the originating sender and the destination are following the valid procedure of bi-directional packet exchange. Any packets that do not properly fit the session conversation template are automatically rejected as impostors. 'check-state' is used to identify where in the IPFW rules set the packet is to be tested against the dynamic rules facility. On a match the packet exits the firewall to continue on its way and a new rule is dynamic created for the next anticipated packet being exchanged during this bi-directional session conversation. On a no match the packet advances to the next rule in the rule set for testing. The dynamic rules facility is vulnerable to resource depletion from a SYN-flood attack which would open a huge number of dynamic rules. To counter this attack, &os; version 4.5 added another new option named limit. This option is used to limit the number of simultaneous session conversations by interrogating the rules source or destinations fields as directed by the limit option and using the packet's IP address found there, in a search of the open dynamic rules counting the number of times this rule and IP address combination occurred, if this count is greater that the value specified on the limit option, the packet is discarded. Logging Firewall Messages The benefits of logging are obvious, provides the ability to review after the fact the rules you activated logging on which provides information like, what packets had been dropped, what addresses they came from, where they were going, giving you a significant edge in tracking down attackers. Even with the logging facility enabled, IPFW will not generate any rule logging on it's own. The firewall administrator decides what rules in the rule set he wants to log and adds the log verb to those rules. Normally only deny rules are logged. Like the deny rule for incoming ICMP pings. It's very customary to duplicate the ipfw default deny everything rule with the log verb included as your last rule in the rule set. This way you get to see all the packets that did not match any of the rules in the rule set. Logging is a two edged sword, if you're not careful, you can lose yourself in the over abundance of log data and fill your disk up with growing log files. DoS attacks that fill up disk drives is one of the oldest attacks around. These log message are not only written to syslogd, but also are displayed on the root console screen and soon become very annoying. The IPFIREWALL_VERBOSE_LIMIT=5 kernel option limits the number of consecutive messages sent to the system logger syslogd, concerning the packet matching of a given rule. When this option is enabled in the kernel, the number of consecutive messages concerning a particular rule is capped at the number specified. There is nothing to be gained from 200 log messages saying the same identical thing. For instance, 5 consecutive messages concerning a particular rule would be logged to syslogd, the remainder identical consecutive messages would be counted and posted to the syslogd with a phrase like this: last message repeated 45 times All logged packets messages are written by default to /var/log/security file, which is defined in the /etc/syslog.conf file. Building Rule Script Most experienced IPFW users create a file containing the rules and code them in a manner compatible with running them as a script. The major benefit of doing this is the firewall rules can be refreshed in mass without the need of rebooting the system to activate the new rules. This method is very convenient in testing new rules as the procedure can be executed as many times as needed. Being a script, you can use symbolic substitution to code frequent used values and substitution them in multiple rules. You will see this in the following example. The script syntax used here is compatible with the 'sh', 'csh', 'tcsh' shells. Symbolic substitution fields are prefixed with a dollar sign $. Symbolic fields do not have the $ prefix. The value to populate the Symbolic field must be enclosed to "double quotes". Start your rules file like this: ############### start of example ipfw rules script ############# # ipfw -q -f flush # Delete all rules # Set defaults oif="tun0" # out interface odns="192.0.2.11" # ISP's dns server IP address cmd="ipfw -q add " # build rule prefix ks="keep-state" # just too lazy to key this each time $cmd 00500 check-state $cmd 00502 deny all from any to any frag $cmd 00501 deny tcp from any to any established $cmd 00600 allow tcp from any to any 80 out via $oif setup $ks $cmd 00610 allow tcp from any to $odns 53 out via $oif setup $ks $cmd 00611 allow udp from any to $odns 53 out via $oif $ks ################### End of example ipfw rules script ############ That is all there is to it. The rules are not important in this example, how the Symbolic substitution field are populated and used are. If the above example was in /etc/ipfw.rules file, you could reload these rules by entering on the command line. sh /etc/ipfw.rules The /etc/ipfw.rules file could be located any where you want and the file could be named any thing you would like. The same thing could also be accomplished by running these commands by hand: ipfw -q -f flush ipfw -q add check-state ipfw -q add deny all from any to any frag ipfw -q add deny tcp from any to any established ipfw -q add allow tcp from any to any 80 out via tun0 setup keep-state ipfw -q add allow tcp from any to 192.0.2.11 53 out via tun0 setup keep-state ipfw -q add 00611 allow udp from any to 192.0.2.11 53 out via tun0 keep-state Stateful Ruleset The following non-NATed rule set is a example of how to code a very secure 'inclusive' type of firewall. An inclusive firewall only allows services matching pass rules through and blocks all other by default. All firewalls have at the minimum two interfaces which have to have rules to allow the firewall to function. All &unix; flavored operating systems, &os; included, are designed to use interface lo and IP address 127.0.0.1 for internal communication with in &os;. The firewall rules must contain rules to allow free unmolested movement of these special internally used packets. The interface which faces the public Internet, is the one which you code your rules to authorize and control access out to the public Internet and access requests arriving from the public Internet. This can be your ppp tun0 interface or your NIC that is connected to your DSL or cable modem. In cases where one or more than one NIC are connected to a private LANs behind the firewall, those interfaces must have rules coded to allow free unmolested movement of packets originating from those LAN interfaces. The rules should be first organized into three major sections, all the free unmolested interfaces, public interface outbound, and the public interface inbound. The order of the rules in each of the public interface sections should be in order of the most used rules being placed before less often used rules with the last rule in the section being a block log all packets on that interface and direction. The Outbound section in the following rule set only contains 'allow' rules which contain selection values that uniquely identify the service that is authorized for public Internet access. All the rules have the, proto, port, in/out, via and keep state option coded. The 'proto tcp' rules have the 'setup' option included to identify the start session request as the trigger packet to be posted to the keep state stateful table. The Inbound section has all the blocking of undesirable packets first for 2 different reasons. First is these things being blocked may be part of an otherwise valid packet which may be allowed in by the later authorized service rules. Second reason is that by having a rule that explicitly blocks selected packets that I receive on an infrequent bases and don't want to see in the log, this keeps them from being caught by the last rule in the section which blocks and logs all packets which have fallen through the rules. The last rule in the section which blocks and logs all packets is how you create the legal evidence needed to prosecute the people who are attacking your system. Another thing you should take note of, is there is no response returned for any of the undesirable stuff, their packets just get dropped and vanish. This way the attackers has no knowledge if his packets have reached your system. The less the attackers can learn about your system the more secure it is. When you log packets with port numbers you do not recognize, go to and do a port number lookup to find what the purpose of that port number is. Check out this link for port numbers used by Trojans: . An Example Inclusive Ruleset The following non-NATed rule set is a complete inclusive type ruleset. You can not go wrong using this rule set for you own. Just comment out any pass rules for services to don't want. If you see messages in your log that you want to stop seeing just add a deny rule in the inbound section. You have to change the 'dc0' interface name in every rule to the interface name of the NIC that connects your system to the public Internet. For user ppp it would be 'tun0'. You will see a pattern in the usage of these rules. All statements that are a request to start a session to the public Internet use keep-state. All the authorized services that originate from the public Internet have the limit option to stop flooding. All rules use in or out to clarify direction. All rules use via interface name to specify the interface the packet is traveling over. The following rules go into /etc/ipfw.rules. ################ Start of IPFW rules file ############################### # Flush out the list before we begin. ipfw -q -f flush # Set rules command prefix cmd="ipfw -q add" pif="dc0" # public interface name of Nic card # facing the public Internet ################################################################# # No restrictions on Inside Lan Interface for private network # Not needed unless you have Lan. # Change xl0 to your Lan Nic card interface name ################################################################# #$cmd 00005 allow all from any to any via xl0 ################################################################# # No restrictions on Loopback Interface ################################################################# $cmd 00010 allow all from any to any via lo0 ################################################################# # Allow the packet through if it has previous been added to the # the "dynamic" rules table by a allow keep-state statement. ################################################################# $cmd 00015 check-state ################################################################# # Interface facing Public Internet (Outbound Section) # Interrogate session start requests originating from behind the # firewall on the private network or from this gateway server # destine for the public Internet. ################################################################# # Allow out access to my ISP's Domain name server. # x.x.x.x must be the IP address of your ISP.s DNS # Dup these lines if your ISP has more than one DNS server # Get the IP addresses from /etc/resolv.conf file $cmd 00110 allow tcp from any to x.x.x.x 53 out via $pif setup keep-state $cmd 00111 allow udp from any to x.x.x.x 53 out via $pif keep-state # Allow out access to my ISP's DHCP server for cable/DSL configurations. # This rule is not needed for .user ppp. connection to the public Internet. # so you can delete this whole group. # Use the following rule and check log for IP address. # Then put IP address in commented out rule & delete first rule $cmd 00120 allow log udp from any to any 67 out via $pif keep-state #$cmd 00120 allow udp from any to x.x.x.x 67 out via $pif keep-state # Allow out non-secure standard www function $cmd 00200 allow tcp from any to any 80 out via $pif setup keep-state # Allow out secure www function https over TLS SSL $cmd 00220 allow tcp from any to any 443 out via $pif setup keep-state # Allow out send & get email function $cmd 00230 allow tcp from any to any 25 out via $pif setup keep-state $cmd 00231 allow tcp from any to any 110 out via $pif setup keep-state # Allow out FBSD (make install & CVSUP) functions # Basically give user root "GOD" privileges. $cmd 00240 allow tcp from me to any out via $pif setup keep-state uid root # Allow out ping $cmd 00250 allow icmp from any to any out via $pif keep-state # Allow out Time $cmd 00260 allow tcp from any to any 37 out via $pif setup keep-state # Allow out nntp news (i.e. news groups) $cmd 00270 allow tcp from any to any 119 out via $pif setup keep-state # Allow out secure FTP, Telnet, and SCP # This function is using SSH (secure shell) $cmd 00280 allow tcp from any to any 22 out via $pif setup keep-state # Allow out whois $cmd 00290 allow tcp from any to any 43 out via $pif setup keep-state # deny and log everything else that.s trying to get out. # This rule enforces the block all by default logic. $cmd 00299 deny log all from any to any out via $pif ################################################################# # Interface facing Public Internet (Inbound Section) # Interrogate packets originating from the public Internet # destine for this gateway server or the private network. ################################################################# # Deny all inbound traffic from non-routable reserved address spaces $cmd 00300 deny all from 192.168.0.0/16 to any in via $pif #RFC 1918 private IP $cmd 00301 deny all from 172.16.0.0/12 to anyin via $pif #RFC 1918 private IP $cmd 00302 deny all from 10.0.0.0/8 to anyin via $pif #RFC 1918 private IP $cmd 00303 deny all from 127.0.0.0/8 to anyin via $pif #loopback $cmd 00304 deny all from 0.0.0.0/8 to anyin via $pif #loopback $cmd 00305 deny all from 169.254.0.0/16 to anyin via $pif #DHCP auto-config $cmd 00306 deny all from 192.0.2.0/24 to anyin via $pif #reserved for docs $cmd 00307 deny all from 204.152.64.0/23 to anyin via $pif #Sun cluster interconnect $cmd 00308 deny all from 224.0.0.0/3 to anyin via $pif #Class D & E multicast # Deny public pings $cmd 00310 deny icmp from any to anyin via $pif # Deny ident $cmd 00315 deny tcp from any to any 113in via $pif # Deny all Netbios service. 137=name, 138=datagram, 139=session # Netbios is MS/Windows sharing services. # Block MS/Windows hosts2 name server requests 81 $cmd 00320 deny tcp from any to any 137in via $pif $cmd 00321 deny tcp from any to any 138in via $pif $cmd 00322 deny tcp from any to any 139in via $pif $cmd 00323 deny tcp from any to any 81 in via $pif # Deny any late arriving packets $cmd 00330 deny all from any to any frag in via $pif # Deny ACK packets that did not match the dynamic rule table $cmd 00332 deny tcp from any to any established in via $pif # Allow traffic in from ISP's DHCP server. This rule must contain # the IP address of your ISP.s DHCP server as it.s the only # authorized source to send this packet type. # Only necessary for cable or DSL configurations. # This rule is not needed for .user ppp. type connection to # the public Internet. This is the same IP address you captured # and used in the outbound section. #$cmd 00360 allow udp from any to x.x.x.x 67 in via $pif keep-state # Allow in standard www function because I have apache server $cmd 00400 allow tcp from any to me 80 in via $pif setup limit src-addr 2 # Allow in secure FTP, Telnet, and SCP from public Internet $cmd 00410 allow tcp from any to me 22 in via $pif setup limit src-addr 2 # Allow in non-secure Telnet session from public Internet # labeled non-secure because ID & PW are passed over public # Internet as clear text. # Delete this sample group if you do not have telnet server enabled. $cmd 00420 allow tcp from any to me 23 in via $pif setup limit src-addr 2 # Reject & Log all incoming connections from the outside $cmd 00499 deny log all from any to any in via $pif # Everything else is denied by default # deny and log all packets that fell through to see what they are $cmd 00999 deny log all from any to any ################ End of IPFW rules file ############################### An Example <acronym>NAT</acronym> and Stateful Ruleset There are some additional configuration statements that need to be enabled to activate the NAT function of IPFW. The kernel source needs 'option divert' statement added to the other IPFIREWALL statements compiled into a custom kernel. In addition to the normal IPFW options in /etc/rc.conf, the following are needed. natd_enable="YES" # Enable NATD function natd_interface="rl0" # interface name of public Internet NIC natd_flags="-dynamic -m" # -m = preserve port numbers if possible Utilizing stateful rules with divert natd rule (Network Address Translation) greatly complicates the rule set coding logic. The positioning of the check-state, and 'divert natd' rules in the rule set becomes very critical. This is no longer a simple fall-through logic flow. A new action type is used, called 'skipto'. To use the skipto command it is mandatory that you number each rule so you know exactly where the skipto rule number is you are really jumping to. The following is an uncommented example of one coding method, selected here to explain the sequence of the packet flow through the rule sets. The processing flow starts with the first rule from the top of the rule file and progress one rule at a time deeper into the file until the end is reach or the packet being tested to the selection criteria matches and the packet is released out of the firewall. It's important to take notice of the location of rule numbers 100 101, 450, 500, and 510. These rules control the translation of the outbound and inbound packets so their entries in the keep-state dynamic table always register the private Lan IP address. Next notice that all the allow and deny rules specified the direction the packet is going (IE outbound or inbound) and the interface. Also notice that all the start outbound session requests all skipto rule 500 for the network address translation. Lets say a LAN user uses their web browser to get a web page. Web pages use port 80 to communicate over. So the packet enters the firewall, It does not match 100 because it is headed out not in. It passes rule 101 because this is the first packet so it has not been posted to the keep-state dynamic table yet. The packet finally comes to rule 125 a matches. It's outbound through the NIC facing the public Internet. The packet still has it's source IP address as a private Lan IP address. On the match to this rule, two action take place. The keep-state option will post this rule into the keep-state dynamic rules table and the specified action is executed. The action is part of the info posted to the dynamic table. In this case it's "skipto rule 500". Rule 500 NATs the packet IP address and out it goes. Remember this, this is very important. This packet makes it's way to the destination and returns and enters the top of the rule set. This time it does match rule 100 and has it destination IP address mapped back to it's corresponding Lan IP address. It then is processed by the check-state rule, it's found in the table as an existing session conversation and released to the LAN. It goes to the LAN PC that sent it and a new packet is sent requesting another segment of the data from the remote server. This time it gets checked by the check-state rule and it's outbound entry is found, the associated action, 'skipto 500', is executed. the packet jumps to rule 500 gets NATed and released on it's way out. On the inbound side, everything coming in that is part of an existing session conversation is being automatically handled by the check-state rule and the properly placed divert natd rules. All we have to address is denying all the bad packets and only allowing in the authorized services. Lets say there is a apache server running on the firewall box and we want people on the public Internet to be able to access the local web site. The new inbound start request packet matches rule 100 and its IP address is mapped to LAN IP for the firewall box. The packet is them matched against all the nasty things we want to check for and finally matches against rule 425. On a match two things occur, the limit option is an extension to keep-state. The packet rule is posted to the keep-state dynamic table but this time any new session requests originating from that source IP address is limited to 2. This defends against DoS attacks of service running on the specified port number. The action is allow so the packet is released to the LAN. On return the check-state rule recognizes the packet as belonging to an existing session conversation sends it to rule 500 for NATing and released to outbound interface. Example Ruleset #1: #!/bin/sh cmd="ipfw -q add" skip="skipto 500" pif=rl0 ks="keep-state" good_tcpo="22,25,37,43,53,80,443,110,119" ipfw -q -f flush $cmd 002 allow all from any to any via xl0 # exclude Lan traffic $cmd 003 allow all from any to any via lo0 # exclude loopback traffic $cmd 100 divert natd ip from any to any in via $pif $cmd 101 check-state # Authorized outbound packets $cmd 120 $skip udp from any to xx.168.240.2 53 out via $pif $ks $cmd 121 $skip udp from any to xx.168.240.5 53 out via $pif $ks $cmd 125 $skip tcp from any to any $good_tcpo out via $pif setup $ks $cmd 130 $skip icmp from any to any out via $pif $ks $cmd 135 $skip udp from any to any 123 out via $pif $ks # Deny all inbound traffic from non-routable reserved address spaces $cmd 300 deny all from 192.168.0.0/16 to any in via $pif #RFC 1918 private IP $cmd 301 deny all from 172.16.0.0/12 to any in via $pif #RFC 1918 private IP $cmd 302 deny all from 10.0.0.0/8 to any in via $pif #RFC 1918 private IP $cmd 303 deny all from 127.0.0.0/8 to any in via $pif #loopback $cmd 304 deny all from 0.0.0.0/8 to any in via $pif #loopback $cmd 305 deny all from 169.254.0.0/16 to any in via $pif #DHCP auto-config $cmd 306 deny all from 192.0.2.0/24 to any in via $pif #reserved for docs $cmd 307 deny all from 204.152.64.0/23 to any in via $pif #Sun cluster $cmd 308 deny all from 224.0.0.0/3 to any in via $pif #Class D & E multicast # Authorized inbound packets $cmd 400 allow udp from xx.70.207.54 to any 68 in $ks $cmd 420 allow tcp from any to me 80 in via $pif setup limit src-addr 1 $cmd 450 deny log ip from any to any # This is skipto location for outbound stateful rules $cmd 500 divert natd ip from any to any out via $pif $cmd 510 allow ip from any to any ######################## end of rules ################## The following is pretty much the same as above but, uses a self documenting coding style full of description comments to help the inexperienced IPFW rule writer to better understand what the rules are doing. Example Ruleset #2: #!/bin/sh ################ Start of IPFW rules file ############################### # Flush out the list before we begin. ipfw -q -f flush # Set rules command prefix cmd="ipfw -q add" skip="skipto 800" pif="rl0" # public interface name of Nic card # facing the public Internet ################################################################# # No restrictions on Inside Lan Interface for private network # Change xl0 to your Lan Nic card interface name ################################################################# $cmd 005 allow all from any to any via xl0 ################################################################# # No restrictions on Loopback Interface ################################################################# $cmd 010 allow all from any to any via lo0 ################################################################# # check if packet is inbound and nat address if it is ################################################################# $cmd 014 divert natd ip from any to any in via $pif ################################################################# # Allow the packet through if it has previous been added to the # the "dynamic" rules table by a allow keep-state statement. ################################################################# $cmd 015 check-state ################################################################# # Interface facing Public Internet (Outbound Section) # Interrogate session start requests originating from behind the # firewall on the private network or from this gateway server # destine for the public Internet. ################################################################# # Allow out access to my ISP's Domain name server. # x.x.x.x must be the IP address of your ISP's DNS # Dup these lines if your ISP has more than one DNS server # Get the IP addresses from /etc/resolv.conf file $cmd 020 $skip tcp from any to x.x.x.x 53 out via $pif setup keep-state # Allow out access to my ISP's DHCP server for cable/DSL configurations. $cmd 030 $skip udp from any to x.x.x.x 67 out via $pif keep-state # Allow out non-secure standard www function $cmd 040 $skip tcp from any to any 80 out via $pif setup keep-state # Allow out secure www function https over TLS SSL $cmd 050 $skip tcp from any to any 443 out via $pif setup keep-state # Allow out send & get email function $cmd 060 $skip tcp from any to any 25 out via $pif setup keep-state $cmd 061 $skip tcp from any to any 110 out via $pif setup keep-state # Allow out FreeBSD (make install & CVSUP) functions # Basically give user root "GOD" privileges. $cmd 070 $skip tcp from me to any out via $pif setup keep-state uid root # Allow out ping $cmd 080 $skip icmp from any to any out via $pif keep-state # Allow out Time $cmd 090 $skip tcp from any to any 37 out via $pif setup keep-state # Allow out nntp news (i.e. news groups) $cmd 100 $skip tcp from any to any 119 out via $pif setup keep-state # Allow out secure FTP, Telnet, and SCP # This function is using SSH (secure shell) $cmd 110 $skip tcp from any to any 22 out via $pif setup keep-state # Allow out whois $cmd 120 $skip tcp from any to any 43 out via $pif setup keep-state # Allow ntp time server $cmd 130 $skip udp from any to any 123 out via $pif keep-state ################################################################# # Interface facing Public Internet (Inbound Section) # Interrogate packets originating from the public Internet # destine for this gateway server or the private network. ################################################################# # Deny all inbound traffic from non-routable reserved address spaces $cmd 300 deny all from 192.168.0.0/16 to any in via $pif #RFC 1918 private IP $cmd 301 deny all from 172.16.0.0/12 to any in via $pif #RFC 1918 private IP $cmd 302 deny all from 10.0.0.0/8 to any in via $pif #RFC 1918 private IP $cmd 303 deny all from 127.0.0.0/8 to any in via $pif #loopback $cmd 304 deny all from 0.0.0.0/8 to any in via $pif #loopback $cmd 305 deny all from 169.254.0.0/16 to any in via $pif #DHCP auto-config $cmd 306 deny all from 192.0.2.0/24 to any in via $pif #reserved for docs $cmd 307 deny all from 204.152.64.0/23 to any in via $pif #Sun cluster $cmd 308 deny all from 224.0.0.0/3 to any in via $pif #Class D & E multicast # Deny ident $cmd 315 deny tcp from any to any 113 in via $pif # Deny all Netbios service. 137=name, 138=datagram, 139=session # Netbios is MS/Windows sharing services. # Block MS/Windows hosts2 name server requests 81 $cmd 320 deny tcp from any to any 137 in via $pif $cmd 321 deny tcp from any to any 138 in via $pif $cmd 322 deny tcp from any to any 139 in via $pif $cmd 323 deny tcp from any to any 81 in via $pif # Deny any late arriving packets $cmd 330 deny all from any to any frag in via $pif # Deny ACK packets that did not match the dynamic rule table $cmd 332 deny tcp from any to any established in via $pif # Allow traffic in from ISP's DHCP server. This rule must contain # the IP address of your ISP's DHCP server as it's the only # authorized source to send this packet type. # Only necessary for cable or DSL configurations. # This rule is not needed for 'user ppp' type connection to # the public Internet. This is the same IP address you captured # and used in the outbound section. $cmd 360 allow udp from x.x.x.x to any 68 in via $pif keep-state # Allow in standard www function because I have apache server $cmd 370 allow tcp from any to me 80 in via $pif setup limit src-addr 2 # Allow in secure FTP, Telnet, and SCP from public Internet $cmd 380 allow tcp from any to me 22 in via $pif setup limit src-addr 2 # Allow in non-secure Telnet session from public Internet # labeled non-secure because ID & PW are passed over public # Internet as clear text. # Delete this sample group if you do not have telnet server enabled. $cmd 390 allow tcp from any to me 23 in via $pif setup limit src-addr 2 # Reject & Log all unauthorized incoming connections from the public Internet $cmd 400 deny log all from any to any in via $pif # Reject & Log all unauthorized out going connections to the public Internet $cmd 450 deny log all from any to any out via $pif # This is skipto location for outbound stateful rules $cmd 800 divert natd ip from any to any out via $pif $cmd 801 allow ip from any to any # Everything else is denied by default # deny and log all packets that fell through to see what they are $cmd 999 deny log all from any to any ################ End of IPFW rules file ############################### Tom Rhodes Written by: OpenSSL security OpenSSL One feature that many users overlook is the OpenSSL toolkit included in &os;. OpenSSL provides an encryption transport layer on top of the normal communications layer; thus allowing it to be intertwined with many network applications and services. Some uses of OpenSSL may include encrypted authentication of mail clients, web based transactions such as credit card payments and more. Many ports such as www/apache13-ssl, and mail/sylpheed-claws will offer compilation support for building with OpenSSL. In most cases the ports collection will attempt to build the security/openssl unless the WITH_OPENSSL_BASE make variable is explicitly set to yes. The version of OpenSSL included in &os; supports Secure Sockets Layer v2/v3 (SSLv2/SSLv3), Transport Layer Security v1 (TLSv1) network security protocols and can be used as a general cryptographic library for use with applications. While OpenSSL supports the IDEA algorithm, it is disabled by default due to United States patents. To use it, the license should be reviewed and, if the restrictions are acceptable, the MAKE_IDEA variable must be set in make.conf. Perhaps one of the most common uses of OpenSSL provide certificates for use with software applications. These certificates ensure that the credentials of the company or individual is valid and are not fraudulent. If the certificate in question has not been verified by one of the several Certificate Authorities, or CAs, a warning is usually produced. A Certificate Authority is a company, such as VeriSign, who will sign certificates in order to validate credentials of individuals or companies. This process has a cost associated with it and is definitely not a requirement for using certificates; however, it can put some of the more paranoid users at ease. Generating Certificates OpenSSL certificate generation To generate a certificate, the following command is available: &prompt.root; openssl req -new -nodes -out req.pem -keyout cert.pem Generating a 1024 bit RSA private key ................++++++ .......................................++++++ writing new private key to 'cert.pem' ----- You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter '.', the field will be left blank. ----- Country Name (2 letter code) [AU]:US State or Province Name (full name) [Some-State]:PA Locality Name (eg, city) []:Pittsburgh Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Company Organizational Unit Name (eg, section) []:Systems Administrator Common Name (eg, YOUR name) []:localhost.example.org Email Address []:trhodes@FreeBSD.org Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []:SOME PASSWORD An optional company name []:Another Name Notice the response directly after the Common Name prompt shows a domain name. This prompt requires a server name to be entered for verification purposes; placing anything but a domain name would yield a useless certificate. Other options for instance expire time, alternate encryption algorithms, etc. are available. A complete list may be obtained by viewing the &man.openssl.1; manual page. A file, cert.pem should now exist in the directory which the aforementioned command was issued. This is the certificate which may be sent to any one of the many CAs for signing. In cases where a signature from a CA is not required, a self signed certificate can be created. First, generate the CA key: &prompt.root; openssl gendsa -des3 -out \ myca.key 1024 Use this key to create the certificate: &prompt.root; openssl req -new -x509 -days 365 -key \ myca.key -out new.crt Two new files should appear in the directory: a certificate authority signature file, myca.key and the certificate itself, new.crt. These should be placed in a directory, preferably under - /etc, which is readable + /etc, which is readable only by root. Permissions of 0700 should be fine for this and they can be set with the chmod utility. Using Certificates, an Example So what can these files do? A good use would be to encrypt connections to the Sendmail MTA. This would dissolve the use of clear text authentication for users who send mail via the local MTA. This is not the best use in the world as some MUAs will present the user with an error if they have not installed the certificate locally. Refer to the documentation included with the software for more information on certificate installation. The following lines should be placed inside the local .mc file: dnl SSL Options define(`confCACERT_PATH',`/etc/certs')dnl define(`confCACERT',`/etc/certs/new.crt')dnl define(`confSERVER_CERT',`/etc/certs/new.crt')dnl define(`confSERVER_KEY',`/etc/certs/myca.key')dnl define(`confTLS_SRV_OPTIONS', `V')dnl - Where /etc/certs/ + Where /etc/certs/ is the directory to be used for storing the certificate and key files locally. The last few requirements are a rebuild of the local .cf file. This is easily achieved by typing make install within the - /etc/mail + /etc/mail directory. Follow that up with make restart which should start the Sendmail daemon. If all went well there will be no error messages in the /var/log/maillog file and Sendmail will show up in the process list. For a simple test, simply connect to the mail server using the &man.telnet.1; utility: &prompt.root; telnet example.com 25 Trying 192.0.34.166... Connected to example.com. Escape character is '^]'. 220 example.com ESMTP Sendmail 8.12.10/8.12.10; Tue, 31 Aug 2004 03:41:22 -0400 (EDT) ehlo example.com 250-example.com Hello example.com [192.0.34.166], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 250-DSN 250-ETRN 250-AUTH LOGIN PLAIN 250-STARTTLS 250-DELIVERBY 250 HELP quit 221 2.0.0 example.com closing connection Connection closed by foreign host. If the STARTTLS line appears in the output then everything is working correctly. Nik Clayton
nik@FreeBSD.org
 Written by VPN over IPsec Creating a VPN between two networks, separated by the Internet, using FreeBSD gateways. Hiten M. Pandya
hmp@FreeBSD.org
 Written by Understanding IPsec This section will guide you through the process of setting up IPsec, and to use it in an environment which consists of FreeBSD and µsoft.windows; 2000/XP machines, to make them communicate securely. In order to set up IPsec, it is necessary that you are familiar with the concepts of building a custom kernel (see ). IPsec is a protocol which sits on top of the Internet Protocol (IP) layer. It allows two or more hosts to communicate in a secure manner (hence the name). The FreeBSD IPsec network stack is based on the KAME implementation, which has support for both protocol families, IPv4 and IPv6. FreeBSD 5.X contains a hardware accelerated IPsec stack, known as Fast IPsec, that was obtained from OpenBSD. It employs cryptographic hardware (whenever possible) via the &man.crypto.4; subsystem to optimize the performance of IPsec. This subsystem is new, and does not support all the features that are available in the KAME version of IPsec. However, in order to enable hardware-accelerated IPsec, the following kernel option has to be added to your kernel configuration file: options FAST_IPSEC # new IPsec (cannot define w/ IPSEC) Note, that it is not currently possible to use the Fast IPsec subsystem in lue with the KAME implementation of IPsec. Consult the &man.fast.ipsec.4; manual page for more information. IPsec consists of two sub-protocols: Encapsulated Security Payload (ESP), protects the IP packet data from third party interference, by encrypting the contents using symmetric cryptography algorithms (like Blowfish, 3DES). Authentication Header (AH), protects the IP packet header from third party interference and spoofing, by computing a cryptographic checksum and hashing the IP packet header fields with a secure hashing function. This is then followed by an additional header that contains the hash, to allow the information in the packet to be authenticated. ESP and AH can either be used together or separately, depending on the environment. IPsec can either be used to directly encrypt the traffic between two hosts (known as Transport Mode); or to build virtual tunnels between two subnets, which could be used for secure communication between two corporate networks (known as Tunnel Mode). The latter is more commonly known as a Virtual Private Network (VPN). The &man.ipsec.4; manual page should be consulted for detailed information on the IPsec subsystem in FreeBSD. To add IPsec support to your kernel, add the following options to your kernel configuration file: options IPSEC #IP security options IPSEC_ESP #IP security (crypto; define w/ IPSEC) If IPsec debugging support is desired, the following kernel option should also be added: options IPSEC_DEBUG #debug for IP security The Problem There is no standard for what constitutes a VPN. VPNs can be implemented using a number of different technologies, each of which have their own strengths and weaknesses. This section presents a scenario, and the strategies used for implementing a VPN for this scenario. The Scenario: Two networks, connected to the Internet, to behave as one The premise is as follows: You have at least two sites Both sites are using IP internally Both sites are connected to the Internet, through a gateway that is running FreeBSD. The gateway on each network has at least one public IP address. The internal addresses of the two networks can be public or private IP addresses, it doesn't matter. You can be running NAT on the gateway machine if necessary. The internal IP addresses of the two networks do not collide. While I expect it is theoretically possible to use a combination of VPN technology and NAT to get this to work, I expect it to be a configuration nightmare. If you find that you are trying to connect two networks, both of which, internally, use the same private IP address range (e.g. both of them use 192.168.1.x), then one of the networks will have to be renumbered. The network topology might look something like this: Network #1 [ Internal Hosts ] Private Net, 192.168.1.2-254 [ Win9x/NT/2K ] [ UNIX ] | | .---[fxp1]---. Private IP, 192.168.1.1 | FreeBSD | `---[fxp0]---' Public IP, A.B.C.D | | -=-=- Internet -=-=- | | .---[fxp0]---. Public IP, W.X.Y.Z | FreeBSD | `---[fxp1]---' Private IP, 192.168.2.1 | | Network #2 [ Internal Hosts ] [ Win9x/NT/2K ] Private Net, 192.168.2.2-254 [ UNIX ] Notice the two public IP addresses. I'll use the letters to refer to them in the rest of this article. Anywhere you see those letters in this article, replace them with your own public IP addresses. Note also that internally, the two gateway machines have .1 IP addresses, and that the two networks have different private IP addresses (192.168.1.x and 192.168.2.x respectively). All the machines on the private networks have been configured to use the .1 machine as their default gateway. The intention is that, from a network point of view, each network should view the machines on the other network as though they were directly attached the same router -- albeit a slightly slow router with an occasional tendency to drop packets. This means that (for example), machine 192.168.1.20 should be able to run ping 192.168.2.34 and have it work, transparently. &windows; machines should be able to see the machines on the other network, browse file shares, and so on, in exactly the same way that they can browse machines on the local network. And the whole thing has to be secure. This means that traffic between the two networks has to be encrypted. Creating a VPN between these two networks is a multi-step process. The stages are as follows: Create a virtual network link between the two networks, across the Internet. Test it, using tools like &man.ping.8;, to make sure it works. Apply security policies to ensure that traffic between the two networks is transparently encrypted and decrypted as necessary. Test this, using tools like &man.tcpdump.1;, to ensure that traffic is encrypted. Configure additional software on the FreeBSD gateways, to allow &windows; machines to see one another across the VPN. Step 1: Creating and testing a <quote>virtual</quote> network link Suppose that you were logged in to the gateway machine on network #1 (with public IP address A.B.C.D, private IP address 192.168.1.1), and you ran ping 192.168.2.1, which is the private address of the machine with IP address W.X.Y.Z. What needs to happen in order for this to work? The gateway machine needs to know how to reach 192.168.2.1. In other words, it needs to have a route to 192.168.2.1. Private IP addresses, such as those in the 192.168.x range are not supposed to appear on the Internet at large. Instead, each packet you send to 192.168.2.1 will need to be wrapped up inside another packet. This packet will need to appear to be from A.B.C.D, and it will have to be sent to W.X.Y.Z. This process is called encapsulation. Once this packet arrives at W.X.Y.Z it will need to unencapsulated, and delivered to 192.168.2.1. You can think of this as requiring a tunnel between the two networks. The two tunnel mouths are the IP addresses A.B.C.D and W.X.Y.Z, and the tunnel must be told the addresses of the private IP addresses that will be allowed to pass through it. The tunnel is used to transfer traffic with private IP addresses across the public Internet. This tunnel is created by using the generic interface, or gif devices on FreeBSD. As you can imagine, the gif interface on each gateway host must be configured with four IP addresses; two for the public IP addresses, and two for the private IP addresses. Support for the gif device must be compiled in to the &os; kernel on both machines. You can do this by adding the line: pseudo-device gif to the kernel configuration files on both machines, and then compile, install, and reboot as normal. Configuring the tunnel is a two step process. First the tunnel must be told what the outside (or public) IP addresses are, using &man.gifconfig.8;. Then the private IP addresses must be configured using &man.ifconfig.8;. In &os; 5.X, the functionality provided by the &man.gifconfig.8; utility has been merged into &man.ifconfig.8;. On the gateway machine on network #1 you would run the following two commands to configure the tunnel. gifconfig gif0 A.B.C.D W.X.Y.Z ifconfig gif0 inet 192.168.1.1 192.168.2.1 netmask 0xffffffff On the other gateway machine you run the same commands, but with the order of the IP addresses reversed. gifconfig gif0 W.X.Y.Z A.B.C.D ifconfig gif0 inet 192.168.2.1 192.168.1.1 netmask 0xffffffff You can then run: gifconfig gif0 to see the configuration. For example, on the network #1 gateway, you would see this: &prompt.root; gifconfig gif0 gif0: flags=8011<UP,POINTTOPOINT,MULTICAST> mtu 1280 inet 192.168.1.1 --> 192.168.2.1 netmask 0xffffffff physical address inet A.B.C.D --> W.X.Y.Z As you can see, a tunnel has been created between the physical addresses A.B.C.D and W.X.Y.Z, and the traffic allowed through the tunnel is that between 192.168.1.1 and 192.168.2.1. This will also have added an entry to the routing table on both machines, which you can examine with the command netstat -rn. This output is from the gateway host on network #1. &prompt.root; netstat -rn Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire ... 192.168.2.1 192.168.1.1 UH 0 0 gif0 ... As the Flags value indicates, this is a host route, which means that each gateway knows how to reach the other gateway, but they do not know how to reach the rest of their respective networks. That problem will be fixed shortly. It is likely that you are running a firewall on both machines. This will need to be circumvented for your VPN traffic. You might want to allow all traffic between both networks, or you might want to include firewall rules that protect both ends of the VPN from one another. It greatly simplifies testing if you configure the firewall to allow all traffic through the VPN. You can always tighten things up later. If you are using &man.ipfw.8; on the gateway machines then a command like ipfw add 1 allow ip from any to any via gif0 will allow all traffic between the two end points of the VPN, without affecting your other firewall rules. Obviously you will need to run this command on both gateway hosts. This is sufficient to allow each gateway machine to ping the other. On 192.168.1.1, you should be able to run ping 192.168.2.1 and get a response, and you should be able to do the same thing on the other gateway machine. However, you will not be able to reach internal machines on either network yet. This is because of the routing -- although the gateway machines know how to reach one another, they do not know how to reach the network behind each one. To solve this problem you must add a static route on each gateway machine. The command to do this on the first gateway would be: route add 192.168.2.0 192.168.2.1 netmask 0xffffff00 This says In order to reach the hosts on the network 192.168.2.0, send the packets to the host 192.168.2.1. You will need to run a similar command on the other gateway, but with the 192.168.1.x addresses instead. IP traffic from hosts on one network will now be able to reach hosts on the other network. That has now created two thirds of a VPN between the two networks, in as much as it is virtual and it is a network. It is not private yet. You can test this using &man.ping.8; and &man.tcpdump.1;. Log in to the gateway host and run tcpdump dst host 192.168.2.1 In another log in session on the same host run ping 192.168.2.1 You will see output that looks something like this: 16:10:24.018080 192.168.1.1 > 192.168.2.1: icmp: echo request 16:10:24.018109 192.168.1.1 > 192.168.2.1: icmp: echo reply 16:10:25.018814 192.168.1.1 > 192.168.2.1: icmp: echo request 16:10:25.018847 192.168.1.1 > 192.168.2.1: icmp: echo reply 16:10:26.028896 192.168.1.1 > 192.168.2.1: icmp: echo request 16:10:26.029112 192.168.1.1 > 192.168.2.1: icmp: echo reply As you can see, the ICMP messages are going back and forth unencrypted. If you had used the parameter to &man.tcpdump.1; to grab more bytes of data from the packets you would see more information. Obviously this is unacceptable. The next section will discuss securing the link between the two networks so that it all traffic is automatically encrypted. Summary: Configure both kernels with pseudo-device gif. Edit /etc/rc.conf on gateway host #1 and add the following lines (replacing IP addresses as necessary). gifconfig_gif0="A.B.C.D W.X.Y.Z" ifconfig_gif0="inet 192.168.1.1 192.168.2.1 netmask 0xffffffff" static_routes="vpn" route_vpn="192.168.2.0 192.168.2.1 netmask 0xffffff00" Edit your firewall script (/etc/rc.firewall, or similar) on both hosts, and add ipfw add 1 allow ip from any to any via gif0 Make similar changes to /etc/rc.conf on gateway host #2, reversing the order of IP addresses. Step 2: Securing the link To secure the link we will be using IPsec. IPsec provides a mechanism for two hosts to agree on an encryption key, and to then use this key in order to encrypt data between the two hosts. The are two areas of configuration to be considered here. There must be a mechanism for two hosts to agree on the encryption mechanism to use. Once two hosts have agreed on this mechanism there is said to be a security association between them. There must be a mechanism for specifying which traffic should be encrypted. Obviously, you don't want to encrypt all your outgoing traffic -- you only want to encrypt the traffic that is part of the VPN. The rules that you put in place to determine what traffic will be encrypted are called security policies. Security associations and security policies are both maintained by the kernel, and can be modified by userland programs. However, before you can do this you must configure the kernel to support IPsec and the Encapsulated Security Payload (ESP) protocol. This is done by configuring a kernel with: options IPSEC options IPSEC_ESP and recompiling, reinstalling, and rebooting. As before you will need to do this to the kernels on both of the gateway hosts. You have two choices when it comes to setting up security associations. You can configure them by hand between two hosts, which entails choosing the encryption algorithm, encryption keys, and so forth, or you can use daemons that implement the Internet Key Exchange protocol (IKE) to do this for you. I recommend the latter. Apart from anything else, it is easier to set up. Editing and displaying security policies is carried out using &man.setkey.8;. By analogy, setkey is to the kernel's security policy tables as &man.route.8; is to the kernel's routing tables. setkey can also display the current security associations, and to continue the analogy further, is akin to netstat -r in that respect. There are a number of choices for daemons to manage security associations with FreeBSD. This article will describe how to use one of these, racoon. racoon is in the FreeBSD ports collection, in the security/ category, and is installed in the usual way. racoon must be run on both gateway hosts. On each host it is configured with the IP address of the other end of the VPN, and a secret key (which you choose, and must be the same on both gateways). The two daemons then contact one another, confirm that they are who they say they are (by using the secret key that you configured). The daemons then generate a new secret key, and use this to encrypt the traffic over the VPN. They periodically change this secret, so that even if an attacker were to crack one of the keys (which is as theoretically close to unfeasible as it gets) it won't do them much good -- by the time they've cracked the key the two daemons have chosen another one. racoon's configuration is stored in ${PREFIX}/etc/racoon. You should find a configuration file there, which should not need to be changed too much. The other component of racoon's configuration, which you will need to change, is the pre-shared key. The default racoon configuration expects to find this in the file ${PREFIX}/etc/racoon/psk.txt. It is important to note that the pre-shared key is not the key that will be used to encrypt your traffic across the VPN link, it is simply a token that allows the key management daemons to trust one another. psk.txt contains a line for each remote site you are dealing with. In this example, where there are two sites, each psk.txt file will contain one line (because each end of the VPN is only dealing with one other end). On gateway host #1 this line should look like this: W.X.Y.Z secret That is, the public IP address of the remote end, whitespace, and a text string that provides the secret. Obviously, you shouldn't use secret as your key -- the normal rules for choosing a password apply. On gateway host #2 the line would look like this A.B.C.D secret That is, the public IP address of the remote end, and the same secret key. psk.txt must be mode 0600 (i.e., only read/write to root) before racoon will run. You must run racoon on both gateway machines. You will also need to add some firewall rules to allow the IKE traffic, which is carried over UDP to the ISAKMP (Internet Security Association Key Management Protocol) port. Again, this should be fairly early in your firewall ruleset. ipfw add 1 allow udp from A.B.C.D to W.X.Y.Z isakmp ipfw add 1 allow udp from W.X.Y.Z to A.B.C.D isakmp Once racoon is running you can try pinging one gateway host from the other. The connection is still not encrypted, but racoon will then set up the security associations between the two hosts -- this might take a moment, and you may see this as a short delay before the ping commands start responding. Once the security association has been set up you can view it using &man.setkey.8;. Run setkey -D on either host to view the security association information. That's one half of the problem. They other half is setting your security policies. To create a sensible security policy, let's review what's been set up so far. This discussions hold for both ends of the link. Each IP packet that you send out has a header that contains data about the packet. The header includes the IP addresses of both the source and destination. As we already know, private IP addresses, such as the 192.168.x.y range are not supposed to appear on the public Internet. Instead, they must first be encapsulated inside another packet. This packet must have the public source and destination IP addresses substituted for the private addresses. So if your outgoing packet started looking like this: .----------------------. | Src: 192.168.1.1 | | Dst: 192.168.2.1 | | <other header info> | +----------------------+ | <packet data> | `----------------------' Then it will be encapsulated inside another packet, looking something like this: .--------------------------. | Src: A.B.C.D | | Dst: W.X.Y.Z | | <other header info> | +--------------------------+ | .----------------------. | | | Src: 192.168.1.1 | | | | Dst: 192.168.2.1 | | | | <other header info> | | | +----------------------+ | | | <packet data> | | | `----------------------' | `--------------------------' This encapsulation is carried out by the gif device. As you can see, the packet now has real IP addresses on the outside, and our original packet has been wrapped up as data inside the packet that will be put out on the Internet. Obviously, we want all traffic between the VPNs to be encrypted. You might try putting this in to words, as: If a packet leaves from A.B.C.D, and it is destined for W.X.Y.Z, then encrypt it, using the necessary security associations. If a packet arrives from W.X.Y.Z, and it is destined for A.B.C.D, then decrypt it, using the necessary security associations. That's close, but not quite right. If you did this, all traffic to and from W.X.Y.Z, even traffic that was not part of the VPN, would be encrypted. That's not quite what you want. The correct policy is as follows If a packet leaves from A.B.C.D, and that packet is encapsulating another packet, and it is destined for W.X.Y.Z, then encrypt it, using the necessary security associations. If a packet arrives from W.X.Y.Z, and that packet is encapsulating another packet, and it is destined for A.B.C.D, then decrypt it, using the necessary security associations. A subtle change, but a necessary one. Security policies are also set using &man.setkey.8;. &man.setkey.8; features a configuration language for defining the policy. You can either enter configuration instructions via stdin, or you can use the option to specify a filename that contains configuration instructions. The configuration on gateway host #1 (which has the public IP address A.B.C.D) to force all outbound traffic to W.X.Y.Z to be encrypted is: spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P out ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require; Put these commands in a file (e.g. /etc/ipsec.conf) and then run &prompt.root; setkey -f /etc/ipsec.conf tells &man.setkey.8; that we want to add a rule to the secure policy database. The rest of this line specifies which packets will match this policy. A.B.C.D/32 and W.X.Y.Z/32 are the IP addresses and netmasks that identify the network or hosts that this policy will apply to. In this case, we want it to apply to traffic between these two hosts. tells the kernel that this policy should only apply to packets that encapsulate other packets. says that this policy applies to outgoing packets, and says that the packet will be secured. The second line specifies how this packet will be encrypted. is the protocol that will be used, while indicates that the packet will be further encapsulated in an IPsec packet. The repeated use of A.B.C.D and W.X.Y.Z is used to select the security association to use, and the final mandates that packets must be encrypted if they match this rule. This rule only matches outgoing packets. You will need a similar rule to match incoming packets. spdadd W.X.Y.Z/32 A.B.C.D/32 ipencap -P in ipsec esp/tunnel/W.X.Y.Z-A.B.C.D/require; Note the instead of in this case, and the necessary reversal of the IP addresses. The other gateway host (which has the public IP address W.X.Y.Z) will need similar rules. spdadd W.X.Y.Z/32 A.B.C.D/32 ipencap -P out ipsec esp/tunnel/W.X.Y.Z-A.B.C.D/require; spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P in ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require; Finally, you need to add firewall rules to allow ESP and IPENCAP packets back and forth. These rules will need to be added to both hosts. ipfw add 1 allow esp from A.B.C.D to W.X.Y.Z ipfw add 1 allow esp from W.X.Y.Z to A.B.C.D ipfw add 1 allow ipencap from A.B.C.D to W.X.Y.Z ipfw add 1 allow ipencap from W.X.Y.Z to A.B.C.D Because the rules are symmetric you can use the same rules on each gateway host. Outgoing packets will now look something like this: .------------------------------. --------------------------. | Src: A.B.C.D | | | Dst: W.X.Y.Z | | | <other header info> | | Encrypted +------------------------------+ | packet. | .--------------------------. | -------------. | contents | | Src: A.B.C.D | | | | are | | Dst: W.X.Y.Z | | | | completely | | <other header info> | | | |- secure | +--------------------------+ | | Encap'd | from third | | .----------------------. | | -. | packet | party | | | Src: 192.168.1.1 | | | | Original |- with real | snooping | | | Dst: 192.168.2.1 | | | | packet, | IP addr | | | | <other header info> | | | |- private | | | | +----------------------+ | | | IP addr | | | | | <packet data> | | | | | | | | `----------------------' | | -' | | | `--------------------------' | -------------' | `------------------------------' --------------------------' When they are received by the far end of the VPN they will first be decrypted (using the security associations that have been negotiated by racoon). Then they will enter the gif interface, which will unwrap the second layer, until you are left with the innermost packet, which can then travel in to the inner network. You can check the security using the same &man.ping.8; test from earlier. First, log in to the A.B.C.D gateway machine, and run: tcpdump dst host 192.168.2.1 In another log in session on the same host run ping 192.168.2.1 This time you should see output like the following: XXX tcpdump output Now, as you can see, &man.tcpdump.1; shows the ESP packets. If you try to examine them with the option you will see (apparently) gibberish, because of the encryption. Congratulations. You have just set up a VPN between two remote sites. Summary Configure both kernels with: options IPSEC options IPSEC_ESP Install security/racoon. Edit ${PREFIX}/etc/racoon/psk.txt on both gateway hosts, adding an entry for the remote host's IP address and a secret key that they both know. Make sure this file is mode 0600. Add the following lines to /etc/rc.conf on each host: ipsec_enable="YES" ipsec_file="/etc/ipsec.conf" Create an /etc/ipsec.conf on each host that contains the necessary spdadd lines. On gateway host #1 this would be: spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P out ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require; spdadd W.X.Y.Z/32 A.B.C.D/32 ipencap -P in ipsec esp/tunnel/W.X.Y.Z-A.B.C.D/require; On gateway host #2 this would be: spdadd W.X.Y.Z/32 A.B.C.D/32 ipencap -P out ipsec esp/tunnel/W.X.Y.Z-A.B.C.D/require; spdadd A.B.C.D/32 W.X.Y.Z/32 ipencap -P in ipsec esp/tunnel/A.B.C.D-W.X.Y.Z/require; Add firewall rules to allow IKE, ESP, and IPENCAP traffic to both hosts: ipfw add 1 allow udp from A.B.C.D to W.X.Y.Z isakmp ipfw add 1 allow udp from W.X.Y.Z to A.B.C.D isakmp ipfw add 1 allow esp from A.B.C.D to W.X.Y.Z ipfw add 1 allow esp from W.X.Y.Z to A.B.C.D ipfw add 1 allow ipencap from A.B.C.D to W.X.Y.Z ipfw add 1 allow ipencap from W.X.Y.Z to A.B.C.D The previous two steps should suffice to get the VPN up and running. Machines on each network will be able to refer to one another using IP addresses, and all traffic across the link will be automatically and securely encrypted. Chern Lee Contributed by OpenSSH OpenSSH security OpenSSH OpenSSH is a set of network connectivity tools used to access remote machines securely. It can be used as a direct replacement for rlogin, rsh, rcp, and telnet. Additionally, any other TCP/IP connections can be tunneled/forwarded securely through SSH. OpenSSH encrypts all traffic to effectively eliminate eavesdropping, connection hijacking, and other network-level attacks. OpenSSH is maintained by the OpenBSD project, and is based upon SSH v1.2.12 with all the recent bug fixes and updates. It is compatible with both SSH protocols 1 and 2. OpenSSH has been in the base system since FreeBSD 4.0. Advantages of Using OpenSSH Normally, when using &man.telnet.1; or &man.rlogin.1;, data is sent over the network in an clear, un-encrypted form. Network sniffers anywhere in between the client and server can steal your user/password information or data transferred in your session. OpenSSH offers a variety of authentication and encryption methods to prevent this from happening. Enabling sshd OpenSSH enabling Be sure to make the following addition to your rc.conf file: sshd_enable="YES" This will load &man.sshd.8;, the daemon program for OpenSSH, the next time your system initializes. Alternatively, you can simply run directly the sshd daemon by typing sshd on the command line. SSH Client OpenSSH client The &man.ssh.1; utility works similarly to &man.rlogin.1;. &prompt.root; ssh user@example.com Host key not found from the list of known hosts. Are you sure you want to continue connecting (yes/no)? yes Host 'example.com' added to the list of known hosts. user@example.com's password: ******* The login will continue just as it would have if a session was created using rlogin or telnet. SSH utilizes a key fingerprint system for verifying the authenticity of the server when the client connects. The user is prompted to enter yes only when connecting for the first time. Future attempts to login are all verified against the saved fingerprint key. The SSH client will alert you if the saved fingerprint differs from the received fingerprint on future login attempts. The fingerprints are saved in ~/.ssh/known_hosts, or ~/.ssh/known_hosts2 for SSH v2 fingerprints. By default, OpenSSH servers are configured to accept both SSH v1 and SSH v2 connections. The client, however, can choose between the two. Version 2 is known to be more robust and secure than its predecessor. The &man.ssh.1; command can be forced to use either protocol by passing it the or argument for v1 and v2, respectively. Secure Copy OpenSSH secure copy scp The &man.scp.1; command works similarly to &man.rcp.1;; it copies a file to or from a remote machine, except in a secure fashion. &prompt.root; scp user@example.com:/COPYRIGHT COPYRIGHT user@example.com's password: ******* COPYRIGHT 100% |*****************************| 4735 00:00 &prompt.root; Since the fingerprint was already saved for this host in the previous example, it is verified when using &man.scp.1; here. The arguments passed to &man.scp.1; are similar to &man.cp.1;, with the file or files in the first argument, and the destination in the second. Since the file is fetched over the network, through SSH, one or more of the file arguments takes on the form . Configuration OpenSSH configuration The system-wide configuration files for both the OpenSSH daemon and client reside within the /etc/ssh directory. ssh_config configures the client settings, while sshd_config configures the daemon. Additionally, the (/usr/sbin/sshd by default), and rc.conf options can provide more levels of configuration. ssh-keygen Instead of using passwords, &man.ssh-keygen.1; can be used to generate RSA keys to authenticate a user: &prompt.user; ssh-keygen -t rsa1 Initializing random number generator... Generating p: .++ (distance 66) Generating q: ..............................++ (distance 498) Computing the keys... Key generation complete. Enter file in which to save the key (/home/user/.ssh/identity): Enter passphrase: Enter the same passphrase again: Your identification has been saved in /home/user/.ssh/identity. ... &man.ssh-keygen.1; will create a public and private key pair for use in authentication. The private key is stored in ~/.ssh/identity, whereas the public key is stored in ~/.ssh/identity.pub. The public key must be placed in ~/.ssh/authorized_keys of the remote machine in order for the setup to work. This will allow connection to the remote machine based upon RSA authentication instead of passwords. The option will create RSA keys for use by SSH protocol version 1. If you want to use RSA keys with the SSH protocol version 2, you have to use the command ssh-keygen -t rsa. If a passphrase is used in &man.ssh-keygen.1;, the user will be prompted for a password each time in order to use the private key. A SSH protocol version 2 DSA key can be created for the same purpose by using the ssh-keygen -t dsa command. This will create a public/private DSA key for use in SSH protocol version 2 sessions only. The public key is stored in ~/.ssh/id_dsa.pub, while the private key is in ~/.ssh/id_dsa. DSA public keys are also placed in ~/.ssh/authorized_keys on the remote machine. &man.ssh-agent.1; and &man.ssh-add.1; are utilities used in managing multiple passworded private keys. The various options and files can be different according to the OpenSSH version you have on your system, to avoid problems you should consult the &man.ssh-keygen.1; manual page. SSH Tunneling OpenSSH tunneling OpenSSH has the ability to create a tunnel to encapsulate another protocol in an encrypted session. The following command tells &man.ssh.1; to create a tunnel for telnet: &prompt.user; ssh -2 -N -f -L 5023:localhost:23 user@foo.example.com &prompt.user; The ssh command is used with the following options: Forces ssh to use version 2 of the protocol. (Do not use if you are working with older SSH servers) Indicates no command, or tunnel only. If omitted, ssh would initiate a normal session. Forces ssh to run in the background. Indicates a local tunnel in localport:remotehost:remoteport fashion. The remote SSH server. An SSH tunnel works by creating a listen socket on localhost on the specified port. It then forwards any connection received on the local host/port via the SSH connection to the specified remote host and port. In the example, port 5023 on localhost is being forwarded to port 23 on localhost of the remote machine. Since 23 is telnet, this would create a secure telnet session through an SSH tunnel. This can be used to wrap any number of insecure TCP protocols such as SMTP, POP3, FTP, etc. Using SSH to Create a Secure Tunnel for SMTP &prompt.user; ssh -2 -N -f -L 5025:localhost:25 user@mailserver.example.com user@mailserver.example.com's password: ***** &prompt.user; telnet localhost 5025 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 mailserver.example.com ESMTP This can be used in conjunction with an &man.ssh-keygen.1; and additional user accounts to create a more seamless/hassle-free SSH tunneling environment. Keys can be used in place of typing a password, and the tunnels can be run as a separate user. Practical SSH Tunneling Examples Secure Access of a POP3 Server At work, there is an SSH server that accepts connections from the outside. On the same office network resides a mail server running a POP3 server. The network, or network path between your home and office may or may not be completely trustable. Because of this, you need to check your e-mail in a secure manner. The solution is to create an SSH connection to your office's SSH server, and tunnel through to the mail server. &prompt.user; ssh -2 -N -f -L 2110:mail.example.com:110 user@ssh-server.example.com user@ssh-server.example.com's password: ****** When the tunnel is up and running, you can point your mail client to send POP3 requests to localhost port 2110. A connection here will be forwarded securely across the tunnel to mail.example.com. Bypassing a Draconian Firewall Some network administrators impose extremely draconian firewall rules, filtering not only incoming connections, but outgoing connections. You may be only given access to contact remote machines on ports 22 and 80 for SSH and web surfing. You may wish to access another (perhaps non-work related) service, such as an Ogg Vorbis server to stream music. If this Ogg Vorbis server is streaming on some other port than 22 or 80, you will not be able to access it. The solution is to create an SSH connection to a machine outside of your network's firewall, and use it to tunnel to the Ogg Vorbis server. &prompt.user; ssh -2 -N -f -L 8888:music.example.com:8000 user@unfirewalled-system.example.org user@unfirewalled-system.example.org's password: ******* Your streaming client can now be pointed to localhost port 8888, which will be forwarded over to music.example.com port 8000, successfully evading the firewall. Further Reading OpenSSH &man.ssh.1; &man.scp.1; &man.ssh-keygen.1; &man.ssh-agent.1; &man.ssh-add.1; &man.sshd.8; &man.sftp-server.8; Tom Rhodes Contributed by ACL File System Access Control Lists In conjunction with file system enhancements like snapshots, FreeBSD 5.0 and later offers the security of File System Access Control Lists (ACLs). Access Control Lists extend the standard &unix; permission model in a highly compatible (&posix;.1e) way. This feature permits an administrator to make use of and take advantage of a more sophisticated security model. To enable ACL support for UFS file systems, the following: options UFS_ACL must be compiled into the kernel. If this option has not been compiled in, a warning message will be displayed when attempting to mount a file system supporting ACLs. This option is included in the GENERIC kernel. ACLs rely on extended attributes being enabled on the file system. Extended attributes are natively supported in the next generation &unix; file system, UFS2. A higher level of administrative overhead is required to configure extended attributes on UFS1 than on UFS2. The performance of extended attributes on UFS2 is also substantially higher. As a result, UFS2 is generally recommended in preference to UFS1 for use with access control lists. ACLs are enabled by the mount-time administrative flag, , which may be added to /etc/fstab. The mount-time flag can also be automatically set in a persistent manner using &man.tunefs.8; to modify a superblock ACLs flag in the file system header. In general, it is preferred to use the superblock flag for several reasons: The mount-time ACLs flag cannot be changed by a remount (&man.mount.8; ), only by means of a complete &man.umount.8; and fresh &man.mount.8;. This means that ACLs cannot be enabled on the root file system after boot. It also means that you cannot change the disposition of a file system once it is in use. Setting the superblock flag will cause the file system to always be mounted with ACLs enabled even if there is not an fstab entry or if the devices re-order. This prevents accidental mounting of the file system without ACLs enabled, which can result in ACLs being improperly enforced, and hence security problems. We may change the ACLs behavior to allow the flag to be enabled without a complete fresh &man.mount.8;, but we consider it desirable to discourage accidental mounting without ACLs enabled, because you can shoot your feet quite nastily if you enable ACLs, then disable them, then re-enable them without flushing the extended attributes. In general, once you have enabled ACLs on a file system, they should not be disabled, as the resulting file protections may not be compatible with those intended by the users of the system, and re-enabling ACLs may re-attach the previous ACLs to files that have since had their permissions changed, resulting in other unpredictable behavior. File systems with ACLs enabled will show a + (plus) sign in their permission settings when viewed. For example: drwx------ 2 robert robert 512 Dec 27 11:54 private drwxrwx---+ 2 robert robert 512 Dec 23 10:57 directory1 drwxrwx---+ 2 robert robert 512 Dec 22 10:20 directory2 drwxrwx---+ 2 robert robert 512 Dec 27 11:57 directory3 drwxr-xr-x 2 robert robert 512 Nov 10 11:54 public_html Here we see that the directory1, directory2, and directory3 directories are all taking advantage of ACLs. The public_html directory is not. Making Use of <acronym>ACL</acronym>s The file system ACLs can be viewed by the &man.getfacl.1; utility. For instance, to view the ACL settings on the test file, one would use the command: &prompt.user; getfacl test #file:test #owner:1001 #group:1001 user::rw- group::r-- other::r-- To change the ACL settings on this file, invoke the &man.setfacl.1; utility. Observe: &prompt.user; setfacl -k test The flag will remove all of the currently defined ACLs from a file or file system. The more preferable method would be to use as it leaves the basic fields required for ACLs to work. &prompt.user; setfacl -m u:trhodes:rwx,group:web:r--,o::--- test In the aforementioned command, the option was used to modify the default ACL entries. Since there were no pre-defined entries, as they were removed by the previous command, this will restore the default options and assign the options listed. Take care to notice that if you add a user or group which does not exist on the system, an Invalid argument error will be printed to stdout. Tom Rhodes Contributed by FreeBSD Security Advisories &os; Security Advisories Like many production quality operating systems, &os; publishes Security Advisories. These advisories are usually mailed to the security lists and noted in the Errata only after the appropriate releases have been patched. This section will work to explain what an advisory is, how to understand it, and what measures to take in order to patch a system. What does an advisory look like? The &os; security advisories look similar to the one below, taken from the &a.security-notifications.name; mailing list. ============================================================================= &os;-SA-XX:XX.UTIL Security Advisory The &os; Project Topic: denial of service due to some problem Category: core Module: sys Announced: 2003-09-23 Credits: Person@EMAIL-ADDRESS Affects: All releases of &os; &os; 4-STABLE prior to the correction date Corrected: 2003-09-23 16:42:59 UTC (RELENG_4, 4.9-PRERELEASE) 2003-09-23 20:08:42 UTC (RELENG_5_1, 5.1-RELEASE-p6) 2003-09-23 20:07:06 UTC (RELENG_5_0, 5.0-RELEASE-p15) 2003-09-23 16:44:58 UTC (RELENG_4_8, 4.8-RELEASE-p8) 2003-09-23 16:47:34 UTC (RELENG_4_7, 4.7-RELEASE-p18) 2003-09-23 16:49:46 UTC (RELENG_4_6, 4.6-RELEASE-p21) 2003-09-23 16:51:24 UTC (RELENG_4_5, 4.5-RELEASE-p33) 2003-09-23 16:52:45 UTC (RELENG_4_4, 4.4-RELEASE-p43) 2003-09-23 16:54:39 UTC (RELENG_4_3, 4.3-RELEASE-p39) &os; only: NO For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit http://www.FreeBSD.org/security/. I. Background II. Problem Description III. Impact IV. Workaround V. Solution VI. Correction details VII. References The Topic field indicates exactly what the problem is. It is basically an introduction to the current security advisory and notes the utility with the vulnerability. The Category refers to the affected part of the system which may be one of core, contrib, or ports. The core category means that the vulnerability affects a core component of the &os; operating system. The contrib category means that the vulnerability affects software contributed to the &os; Project, such as sendmail. Finally the ports category indicates that the vulnerability affects add on software available as part of the ports collection. The Module field refers to the component location, for instance sys. In this example, we see that the module, sys, is affected; therefore, this vulnerability affects a component used within the kernel. The Announced field reflects the date said security advisory was published, or announced to the world. This means that the security team has verified that the problem does exist and that a patch has been committed to the &os; source code repository. The Credits field gives credit to the individual or organization who noticed the vulnerability and reported it. The Affects field explains which releases of &os; are affected by this vulnerability. For the kernel, a quick look over the output from ident on the affected files will help in determining the revision. For ports, the version number is listed after the port name in /var/db/pkg. If the system does not sync with the &os; CVS repository and rebuild daily, chances are that it is affected. The Corrected field indicates the date, time, time offset, and release that was corrected. The &os; only field indicates whether this vulnerability affects just &os;, or if it affects other operating systems as well. The Background field gives information on exactly what the affected utility is. Most of the time this is why the utility exists in &os;, what it is used for, and a bit of information on how the utility came to be. The Problem Description field explains the security hole in depth. This can include information on flawed code, or even how the utility could be maliciously used to open a security hole. The Impact field describes what type of impact the problem could have on a system. For example, this could be anything from a denial of service attack, to extra privileges available to users, or even giving the attacker superuser access. The Workaround field offers a feasible workaround to system administrators who may be incapable of upgrading the system. This may be due to time constraints, network availability, or a slew of other reasons. Regardless, security should not be taken lightly, and an affected system should either be patched or the security hole workaround should be implemented. The Solution field offers instructions on patching the affected system. This is a step by step tested and verified method for getting a system patched and working securely. The Correction Details field displays the CVS branch or release name with the periods changed to underscore characters. It also shows the revision number of the affected files within each branch. The References field usually offers sources of other information. This can included web URLs, books, mailing lists, and newsgroups.