diff --git a/en_US.ISO8859-1/articles/new-users/article.sgml b/en_US.ISO8859-1/articles/new-users/article.sgml index 92a862ed06..99f641c894 100644 --- a/en_US.ISO8859-1/articles/new-users/article.sgml +++ b/en_US.ISO8859-1/articles/new-users/article.sgml @@ -1,1052 +1,1052 @@ - +
For People New to Both FreeBSD and Unix Annelise Anderson
andrsn@andrsn.stanford.edu
 August 15, 1997 Congratulations on installing FreeBSD! This introduction is for people new to both FreeBSD and Un*x—so it starts with basics. It assumes you're using version 2.0.5 or later of FreeBSD as distributed by BSDi or FreeBSD.org, your system (for now) has a single user (you)—and you're probably pretty good with DOS/Windows or OS/2. Logging in and Getting Out Log in (when you see login:) as a user you created during installation or as root. (Your FreeBSD installation will already have an account for root; root can go anywhere and do anything, including deleting essential files, so be careful!) The symbols &prompt.user; and &prompt.root; in the following stand for the prompt (yours may be different), with &prompt.user; indicating an ordinary user and &prompt.root; indicating root. To log out (and get a new login: prompt) type &prompt.root; exit as often as necessary. Yes, press enter after commands, and remember that Unix is case-sensitive—exit, not EXIT. To shut down the machine type &prompt.root; /sbin/shutdown -h now Or to reboot type &prompt.root; /sbin/shutdown -r now or &prompt.root; /sbin/reboot You can also reboot with CtrlAltDelete. Give it a little time to do its work. This is equivalent to /sbin/reboot in recent releases of FreeBSD and is much, much better than hitting the reset button. You don't want to have to reinstall this thing, do you? Adding A User with Root Privileges If you didn't create any users when you installed the system and are thus logged in as root, you should probably create a user now with &prompt.root; adduser The first time you use adduser, it might ask for some defaults to save. You might want to make the default shell csh instead of sh, if it suggests sh as the default. Otherwise just press enter to accept each default. These defaults are saved in /etc/adduser.conf, an editable file. Suppose you create a user jack with full name Jack Benimble. Give jack a password if security (even kids around who might pound on the keyboard) is an issue. When it asks you if you want to invite jack into other groups, type wheel Login group is ``jack''. Invite jack into other groups: wheel This will make it possible to log in as jack and use the su command to become root. Then you won't get scolded any more for logging in as root. You can quit adduser any time by typing CtrlC, and at the end you'll have a chance to approve your new user or simply type n for no. You might want to create a second new user (jill?) so that when you edit jack's login files, you'll have a hot spare in case something goes wrong. Once you've done this, use exit to get back to a login prompt and log in as jack. In general, it's a good idea to do as much work as possible as an ordinary user who doesn't have the power—and risk—of root. If you already created a user and you want the user to be able to su to root, you can log in as root and edit the file /etc/group, adding jack to the first line (the group wheel). But first you need to practice vi, the text editor--or use the simpler text editor, ee, installed on recent version of FreeBSD. To delete a user, use the rmuser command. Looking Around Logged in as an ordinary user, look around and try out some commands that will access the sources of help and information within FreeBSD. Here are some commands and what they do: id Tells you who you are! pwd Shows you where you are—the current working directory. ls Lists the files in the current directory. ls Lists the files in the current directory with a * after executables, a / after directories, and an @ after symbolic links. ls Lists the files in long format—size, date, permissions. ls Lists hidden dot files with the others. If you're root, the dot files show up without the switch. cd Changes directories. cd .. backs up one level; note the space after cd. cd /usr/local goes there. cd ~ goes to the home directory of the person logged in—e.g., /usr/home/jack. Try cd /cdrom, and then ls, to find out if your CDROM is mounted and working. view filename Lets you look at a file (named filename) without changing it. Try view /etc/fstab. :q to quit. cat filename Displays filename on screen. If it's too long and you can see only the end of it, press ScrollLock and use the up-arrow to move backward; you can use ScrollLock with man pages too. Press ScrollLock again to quit scrolling. You might want to try cat on some of the dot files in your home directory—cat .cshrc, cat .login, cat .profile. You'll notice aliases in .cshrc for some of the ls commands (they're very convenient). You can create other aliases by editing .cshrc. You can make these aliases available to all users on the system by putting them in the system-wide csh configuration file, /etc/csh.cshrc. Getting Help and Information Here are some useful sources of help. Text stands for something of your choice that you type in—usually a command or filename. apropos text Everything containing string text in the whatis database. man text The man page for text. The major source of documentation for Un*x systems. man ls will tell you all the ways to use the ls command. Press Enter to move through text, Ctrlb to go back a page, Ctrlf to go forward, q or Ctrlc to quit. which text Tells you where in the user's path the command text is found. locate text All the paths where the string text is found. whatis text Tells you what the command text does and its man page. Typing whatis * will tell you about all the binaries in the current directory. whereis text Finds the file text, giving its full path. You might want to try using whatis on some common useful commands like cat, more, grep, mv, find, tar, chmod, chown, date, and script. more lets you read a page at a time as it does in DOS, e.g., ls -l | more or more filename. The * works as a wildcard—e.g., ls w* will show you files beginning with w. Are some of these not working very well? Both locate and whatis depend on a database that's rebuilt weekly. If your machine isn't going to be left on over the weekend (and running FreeBSD), you might want to run the commands for daily, weekly, and monthly maintenance now and then. Run them as root and give each one time to finish before you start the next one, for now. &prompt.root; periodic daily output omitted &prompt.root; periodic weekly output omitted &prompt.root; periodic monthly output omitted If you get tired of waiting, press AltF2 to get another virtual console, and log in again. After all, it's a multi-user, multi-tasking system. Nevertheless these commands will probably flash messages on your screen while they're running; you can type clear at the prompt to clear the screen. Once they've run, you might want to look at /var/mail/root and /var/log/messages. Running such commands is part of system administration—and as a single user of a Unix system, you're your own system administrator. Virtually everything you need to be root to do is system administration. Such responsibilities aren't covered very well even in those big fat books on Unix, which seem to devote a lot of space to pulling down menus in windows managers. You might want to get one of the two leading books on systems administration, either Evi Nemeth et.al.'s UNIX System Administration Handbook (Prentice-Hall, 1995, ISBN 0-13-15051-7)—the second edition with the red cover; or Æleen Frisch's Essential System Administration (O'Reilly & Associates, 1993, ISBN 0-937175-80-3). I used Nemeth. Editing Text To configure your system, you need to edit text files. Most of them will be in the /etc directory; and you'll need to su to root to be able to change them. You can use the easy ee, but in the long run the text editor vi is worth learning. There's an excellent tutorial on vi in /usr/src/contrib/nvi/docs/tutorial if you have that installed; otherwise you can get it by ftp to ftp.cdrom.com in the directory FreeBSD/FreeBSD-current/src/contrib/nvi/docs/tutorial. Before you edit a file, you should probably back it up. Suppose you want to edit /etc/rc.conf. You could just use cd /etc to get to the /etc directory and do: &prompt.root; cp rc.conf rc.conf.orig This would copy rc.conf to rc.conf.orig, and you could later copy rc.conf.orig to rc.conf to recover the original. But even better would be moving (renaming) and then copying back: &prompt.root; mv rc.conf rc.conf.orig &prompt.root; cp rc.conf.orig rc.conf because the mv command preserves the original date and owner of the file. You can now edit rc.conf. If you want the original back, you'd then mv rc.conf rc.conf.myedit (assuming you want to preserve your edited version) and then &prompt.root; mv rc.conf.orig rc.conf to put things back the way they were. To edit a file, type &prompt.root; vi filename Move through the text with the arrow keys. Esc (the escape key) puts vi in command mode. Here are some commands: x delete letter the cursor is on dd delete the entire line (even if it wraps on the screen) i insert text at the cursor a insert text after the cursor Once you type i or a, you can enter text. Esc puts you back in command mode where you can type :w to write your changes to disk and continue editing :wq to write and quit :q! to quit without saving changes /text to move the cursor to text; /Enter (the enter key) to find the next instance of text. G to go to the end of the file nG to go to line n in the file, where n is a number CtrlL to redraw the screen Ctrlb and Ctrlf go back and forward a screen, as they do with more and view. Practice with vi in your home directory by creating a new file with vi filename and adding and deleting text, saving the file, and calling it up again. vi delivers some surprises because it's really quite complex, and sometimes you'll inadvertently issue a command that will do something you don't expect. (Some people actually like vi—it's more powerful than DOS EDIT—find out about the :r command.) Use Esc one or more times to be sure you're in command mode and proceed from there when it gives you trouble, save often with :w, and use :q! to get out and start over (from your last :w) when you need to. Now you can cd to /etc, su to root, use vi to edit the file /etc/group, and add a user to wheel so the user has root privileges. Just add a comma and the user's login name to the end of the first line in the file, press Esc, and use :wq to write the file to disk and quit. Instantly effective. (You didn't put a space after the comma, did you?) Printing Files from DOS At this point you probably don't have the printer working, so here's a way to create a file from a man page, move it to a floppy, and then print it from DOS. Suppose you want to read carefully about changing permissions on files (pretty important). You can use the command man chmod to read about it. The command &prompt.user; man chmod | col -b > chmod.txt will remove formatting codes and send the man page to the chmod.txt file instead of showing it on your screen. Now put a dos-formatted diskette in your floppy drive a, su to root, and type &prompt.root; /sbin/mount -t msdos /dev/fd0 /mnt to mount the floppy drive on /mnt. Now (you no longer need to be root, and you can type exit to get back to being user jack) you can go to the directory where you created chmod.txt and copy the file to the floppy with: &prompt.user; cp chmod.txt /mnt and use ls /mnt to get a directory listing of /mnt, which should show the file chmod.txt. You might especially want to make a file from /sbin/dmesg by typing &prompt.user; /sbin/dmesg > dmesg.txt and copying dmesg.txt to the floppy. /sbin/dmesg is the boot log record, and it's useful to understand it because it shows what FreeBSD found when it booted up. If you ask questions on freebsd-questions@FreeBSD.org or on a USENET group—like FreeBSD isn't finding my tape drive, what do I do?—people will want to know what dmesg has to say. You can now dismount the floppy drive (as root) to get the disk out with &prompt.root; /sbin/umount /mnt and reboot to go to DOS. Copy these files to a DOS directory, call them up with DOS EDIT, Windows Notepad or Wordpad, or a word processor, make a minor change so the file has to be saved, and print as you normally would from DOS or Windows. Hope it works! man pages come out best if printed with the dos print command. (Copying files from FreeBSD to a mounted dos partition is in some cases still a little risky.) Getting the printer printing from FreeBSD involves creating an appropriate entry in /etc/printcap and creating a matching spool directory in /var/spool/output. If your printer is on lpt0 (what dos calls LPT1), you may only need to go to /var/spool/output and (as root) create the directory lpd by typing: mkdir lpd, if it doesn't already exist. Then the printer should respond if it's turned on when the system is booted, and lp or lpr should send a file to the printer. Whether or not the file actually prints depends on configuring it, which is covered in the FreeBSD handbook. Other Useful Commands df shows file space and mounted systems. ps aux shows processes running. ps ax is a narrower form. rm filename remove filename. rm -R dir removes a directory dir and all subdirectories—careful! ls -R lists files in the current directory and all subdirectories; I used a variant, ls -AFR > where.txt, to get a list of all the files in / and (separately) /usr before I found better ways to find files. passwd to change user's password (or root's password) man hier man page on the Unix file system Use find to locate filename in /usr or any of its subdirectories with &prompt.user; find /usr -name "filename" You can use * as a wildcard in "filename" (which should be in quotes). If you tell find to search in / instead of /usr it will look for the file(s) on all mounted file systems, including the CDROM and the dos partition. An excellent book that explains Unix commands and utilities is Abrahams & Larson, Unix for the Impatient (2nd ed., Addison-Wesley, 1996). There's also a lot of Unix information on the Internet. Try the Unix Reference Desk. Next Steps You should now have the tools you need to get around and edit files, so you can get everything up and running. There is a great deal of information in the FreeBSD handbook (which is probably on your hard drive) and FreeBSD's web site. A wide variety of packages and ports are on the CDROM as well as the web site. The handbook tells you more about how to use them (get the package if it exists, with pkg_add /cdrom/packages/All/packagename, where packagename is the filename of the package). The cdrom has lists of the packages and ports with brief descriptions in cdrom/packages/index, cdrom/packages/index.txt, and cdrom/ports/index, with fuller descriptions in /cdrom/ports/*/*/pkg/DESCR, where the *s represent subdirectories of kinds of programs and program names respectively. If you find the handbook too sophisticated (what with lndir and all) on installing ports from the cdrom, here's what usually works: Find the port you want, say kermit. There will be a directory for it on the cdrom. Copy the subdirectory to /usr/local (a good place for software you add that should be available to all users) with: &prompt.root; cp -R /cdrom/ports/comm/kermit /usr/local This should result in a /usr/local/kermit subdirectory that has all the files that the kermit subdirectory on the CDROM has. Next, create the directory /usr/ports/distfiles if it doesn't already exist using mkdir. Now check check /cdrom/ports/distfiles for a file with a name that indicates it's the port you want. Copy that file to /usr/ports/distfiles; in recent versions you can skip this step, as FreeBSD will do it for you. In the case of kermit, there is no distfile. Then cd to the subdirectory of /usr/local/kermit that has the file Makefile. Type &prompt.root; make all install During this process the port will ftp to get any compressed files it needs that it didn't find on the cdrom or in /usr/ports/distfiles. If you don't have your network running yet and there was no file for the port in /cdrom/ports/distfiles, you will have to get the distfile using another machine and copy it to /usr/ports/distfiles from a floppy or your dos partition. Read Makefile (with cat or more or view) to find out where to go (the master distribution site) to get the file and what its name is. Its name will be truncated when downloaded to DOS, and after you get it into /usr/ports/distfiles you'll have to rename it (with the mv command) to its original name so it can be found. (Use binary file transfers!) Then go back to /usr/local/kermit, find the directory with Makefile, and type make all install. The other thing that happens when installing ports or packages is that some other program is needed. If the installation stops with a message can't find unzip or whatever, you might need to install the package or port for unzip before you continue. Once it's installed type rehash to make FreeBSD reread the files in the path so it knows what's there. (If you get a lot of path not found messages when you use whereis or which, you might want to make additions to the list of directories in the path statement in .cshrc in your home directory. The path statement in Unix does the same kind of work it does in DOS, except the current directory is not (by default) in the path for security reasons; if the command you want is in the directory you're in, you need to type ./ before the command to make it work; no space after the slash.) You might want to get the most recent version of Netscape from their ftp site. (Netscape requires the X Window System.) There's now a FreeBSD version, so look around carefully. Just use gunzip filename and tar xvf filename on it, move the binary to /usr/local/bin or some other place binaries are kept, rehash, and then put the following lines in .cshrc in each user's home directory or (easier) in /etc/csh.cshrc, the system-wide csh start-up file: setenv XKEYSYMDB /usr/X11R6/lib/X11/XKeysymDB setenv XNLSPATH /usr/X11R6/lib/X11/nls This assumes that the file XKeysymDB and the directory nls are in /usr/X11R6/lib/X11; if they're not, find them and put them there. If you originally got Netscape as a port using the CDROM (or ftp), don't replace /usr/local/bin/netscape with the new netscape binary; this is just a shell script that sets up the environment variables for you. Instead rename the new binary to netscape.bin and replace the old binary, which is /usr/local/netscape/netscape. Your Working Environment Your shell is the most important part of your working environment. In DOS, the usual shell is command.com. The shell is what interprets the commands you type on the command line, and thus communicates with the rest of the operating system. You can also write shell scripts, which are like DOS batch files: a series of commands to be run without your intervention. Two shells come installed with FreeBSD: csh and sh. csh is good for command-line work, but scripts should be written with sh (or bash). You can find out what shell you have by typing echo $SHELL. The csh shell is okay, but tcsh does everything csh does and - more. It It allows you to recall commands with the arrow keys + more. It allows you to recall commands with the arrow keys and edit them. It has tab-key completion of filenames (csh uses the escape key), and it lets you switch to the directory you were last in with cd -. It's also much easier to alter your prompt with tcsh. It makes life a lot easier. Here are the three steps for installing a new shell: Install the shell as a port or a package, just as you would any other port or package. Use rehash and which tcsh (assuming you're installing tcsh) to make sure it got installed. As root, edit /etc/shells, adding a line in the file for the new shell, in this case /usr/local/bin/tcsh, and save the file. (Some ports may do this for you.) Use the chsh command to change your shell to tcsh permanently, or type tcsh at the prompt to change your shell without logging in again. It can be dangerous to change root's shell to something other than sh or csh on early versions of FreeBSD and many other versions of Unix; you may not have a working shell when the system puts you into single user mode. The solution is to use su -m to become root, which will give you the tcsh as root, because the shell is part of the environment. You can make this permanent by adding it to your .tcshrc file as an alias with alias su su -m. When tcsh starts up, it will read the /etc/csh.cshrc and /etc/csh.login files, as does csh. It will also read the .login file in your home directory and the .cshrc file as well, unless you provide a .tcshrc file. This you can do by simply copying .cshrc to .tcshrc. Now that you've installed tcsh, you can adjust your prompt. You can find the details in the manual page for tcsh, but here is a line to put in your .tcshrc that will tell you how many commands you have typed, what time it is, and what directory you are in. It also produces a > if you're an ordinary user and a # if you're root, but tsch will do that in any case: set prompt = "%h %t %~ %# " This should go in the same place as the existing set prompt line if there is one, or under "if($?prompt) then" if not. Comment out the old line; you can always switch back to it if you prefer it. Don't forget the spaces and quotes. You can get the .tcshrc reread by typing source .tcshrc. You can get a listing of other environmental variables that have been set by typing env at the prompt. The result will show you your default editor, pager, and terminal type, among possibly many others. A useful command if you log in from a remote location and can't run a program because the terminal isn't capable is setenv TERM vt100. Other As root, you can dismount the CDROM with /sbin/umount /cdrom, take it out of the drive, insert another one, and mount it with /sbin/mount_cd9660 /dev/cd0a /cdrom assuming cd0a is the device name for your CDROM drive. The most recent versions of FreeBSD let you mount the cdrom with just /sbin/mount /cdrom. Using the live file system—the second of FreeBSD's CDROM disks—is useful if you've got limited space. What is on the live file system varies from release to release. You might try playing games from the cdrom. This involves using lndir, which gets installed with the X Window System, to tell the program(s) where to find the necessary files, because they're in the /cdrom file system instead of in /usr and its subdirectories, which is where they're expected to be. Read man lndir. Comments Welcome If you use this guide I'd be interested in knowing where it was unclear and what was left out that you think should be included, and if it was helpful. My thanks to Eugene W. Stark, professor of computer science at SUNY-Stony Brook, and John Fieber for helpful comments. Annelise Anderson, andrsn@andrsn.stanford.edu
diff --git a/en_US.ISO8859-1/books/developers-handbook/x86/chapter.sgml b/en_US.ISO8859-1/books/developers-handbook/x86/chapter.sgml index 174433eb55..d5b2df1551 100644 --- a/en_US.ISO8859-1/books/developers-handbook/x86/chapter.sgml +++ b/en_US.ISO8859-1/books/developers-handbook/x86/chapter.sgml @@ -1,6539 +1,6539 @@ x86 Assembly Language Programming This chapter was written by G. Adam Stanislav. Whiz Kid Technomagic Synopsis Assembly language programing under Unix is highly undocumented. It is generally assumed that no one would ever want to use it because various Unix systems run on different microprocessors, so everything should be written in C for portability. In reality, C portability is quite a myth. Even C programs need to be modified when ported from one Unix to another, regardless of what processor each runs on. Typically, such a program is full of conditional statements depending on the system it is compiled for. Even if we believe that all of Unix software should be written in C, or some other high-level language, we still need assembly language programmers: Who else would write the section of C library that accesses the kernel? In this chapter I will attempt to show you how you can use assembly language writing Unix programs, specifically under FreeBSD. This chapter does not explain the basics of assembly language. There are enough resources about that (for a complete online course in assembly language, see Randall Hyde's Art of Assembly Language; or if you prefer a printed book, take a look at Jeff Duntemann's Assembly Language Step-by-Step). However, once the chapter is finished, any assembly language programmer will be able to write programs for FreeBSD quickly and efficiently. Copyright © 2000-2001 G. Adam Stanislav. All rights reserved. The Tools The Assembler The most important tool for assembly language programming is the assembler, the software that converts assembly language code into machine language. Two very different assemblers are available for FreeBSD. One is as1, which uses the traditional Unix assembly language syntax. It comes with the system. The other is /usr/ports/devel/nasm. It uses the Intel syntax. Its main advantage is that it can assemble code for many operating systems. It needs to be installed separately, but is completely free. This chapter uses nasm syntax because most assembly language programmers coming to FreeBSD from other operating systems will find it easier to understand. And, because, quite frankly, that is what I am used to. The Linker The output of the assembler, like that of any compiler, needs to be linked to form an executable file. The standard ld1 linker comes with FreeBSD. It works with the code assembled with either assembler. System Calls Default Calling Convention By default, the FreeBSD kernel uses the C calling convention. Further, although the kernel is accessed using int 80h, it is assumed the program will call a function that issues int 80h, rather than issuing int 80h directly. This convention is very convenient, and quite superior to the Microsoft convention used by MS DOS. Why? Because the Unix convention allows any program written in any language to access the kernel. An assembly language program can do that as well. For example, we could open a file: kernel: int 80h ; Call kernel ret open: push dword mode push dword flags push dword path mov eax, 5 call kernel add esp, byte 12 ret This is a very clean and portable way of coding. If you need to port the code to a Unix system which uses a different interrupt, or a different way of passing parameters, all you need to change is the kernel procedure. But assembly language programmers like to shave off cycles. The above example requires a call/ret combination. We can eliminate it by pushing an extra dword: open: push dword mode push dword flags push dword path mov eax, 5 push eax ; Or any other dword int 80h add esp, byte 16 The 5 that we have placed in EAX identifies the kernel function, in this case open. Alternate Calling Convention FreeBSD is an extremely flexible system. It offers other ways of calling the kernel. For it to work, however, the system must have Linux emulation installed. Linux is a Unix-like system. However, its kernel uses the same system-call convention of passing parameters in registers MS DOS does. As with the Unix convention, the function number is placed in EAX. The parameters, however, are not passed on the stack but in EBX, ECX, EDX, ESI, EDI, EBP: open: mov eax, 5 mov ebx, path mov ecx, flags mov edx, mode int 80h This convention has a great disadvantage over the Unix way, at least as far as assembly language programming is concerned: Every time you make a kernel call you must push the registers, then pop them later. This makes your code bulkier and slower. Nevertheless, FreeBSD gives you a choice. If you do choose the Linux convention, you must let the system know about it. After your program is assembled and linked, you need to brand the executable: &prompt.user; brandelf -f Linux filename Which Convention Should You Use? If you are coding specifically for FreeBSD, you should always use the Unix convention: It is faster, you can store global variables in registers, you do not have to brand the executable, and you do not impose the installation of the Linux emulation package on the target system. If you want to create portable code that can also run on Linux, you will probably still want to give the FreeBSD users as efficient a code as possible. I will show you how you can accomplish that after I have explained the basics. Call Numbers To tell the kernel which system service you are calling, place its number in EAX. Of course, you need to know what the number is. The <filename>syscalls</filename> File The numbers are listed in syscalls. locate syscalls finds this file in several different formats, all produced automatically from syscalls.master. You can find the master file for the default Unix calling convention in /usr/src/sys/kern/syscalls.master. If you need to use the other convention implemented in the Linux emulation mode, read /usr/src/sys/i386/linux/syscalls.master. Not only do FreeBSD and Linux use different calling conventions, they sometimes use different numbers for the same functions. syscalls.master describes how the call is to be made: 0 STD NOHIDE { int nosys(void); } syscall nosys_args int 1 STD NOHIDE { void exit(int rval); } exit rexit_args void 2 STD POSIX { int fork(void); } 3 STD POSIX { ssize_t read(int fd, void *buf, size_t nbyte); } 4 STD POSIX { ssize_t write(int fd, const void *buf, size_t nbyte); } 5 STD POSIX { int open(char *path, int flags, int mode); } 6 STD POSIX { int close(int fd); } etc... It is the leftmost column that tells us the number to place in EAX. The rightmost column tells us what parameters to push. They are pushed from right to left. For example, to open a file, we need to push the mode first, then flags, then the address at which the path is stored. Return Values A system call would not be useful most of the time if it did not return some kind of a value: The file descriptor of an open file, the number of bytes read to a buffer, the system time, etc. Additionally, the system needs to inform us if an error occurs: A file does not exist, system resources are exhausted, we passed an invalid parameter, etc. Man Pages The traditional place to look for information about various system calls under Unix systems are the man pages. FreeBSD describes its system calls in section 2, sometimes in section 3. For example, open2 says:
If successful, open() returns a non-negative integer, termed a file descriptor. It returns -1 on failure, and sets errno to indicate the error.
The assembly language programmer new to Unix and FreeBSD will immediately ask the puzzling question: Where is errno and how do I get to it? The information presented in the man pages applies to C programs. The assembly language programmer needs additional information. Where Are the Return Values? Unfortunately, it depends... For most system calls it is in EAX, but not for all. A good rule of thumb, when working with a system call for the first time, is to look for the return value in EAX. If it is not there, you need further research. I am aware of one system call that returns the value in EDX: SYS_fork. All others I have worked with use EAX. But I have not worked with them all yet. If you cannot find the answer here or anywhere else, study libc source code and see how it interfaces with the kernel. Where Is <varname>errno</varname>? Actually, nowhere... errno is part of the C language, not the Unix kernel. When accessing kernel services directly, the error code is returned in EAX, the same register the proper return value generally ends up in. This makes perfect sense. If there is no error, there is no error code. If there is an error, there is no return value. One register can contain either. Determining an Error Occurred When using the standard FreeBSD calling convention, the carry flag is cleared upon success, set upon failure. When using the Linux emulation mode, the signed value in EAX is non-negative upon success, and contains the return value. In case of an error, the value is negative, i.e., -errno. Creating Portable Code Portability is generally not one of the strengths of assembly language. Yet, writing assembly language programs for different platforms is possible, especially with nasm. I have written assembly language libraries that can be assembled for such different operating systems as Windows and FreeBSD. It is all the more possible when you want your code to run on two platforms which, while different, are based on similar architectures. For example, FreeBSD is Unix, Linux is Unix-like. I only mentioned three differences between them (from an assembly language programmer's perspective): The calling convention, the function numbers, and the way of returning values. Dealing with Function Numbers In many cases the function numbers are the same. However, even when they are not, the problem is easy to deal with: Instead of using numbers in your code, use constants which you have declared differently depending on the target architecture: %ifdef LINUX %define SYS_execve 11 %else %define SYS_execve 59 %endif Dealing with Conventions Both, the calling convention, and the return value (the errno problem) can be resolved with macros: %ifdef LINUX %macro system 0 call kernel %endmacro align 4 kernel: push ebx push ecx push edx push esi push edi push ebp mov ebx, [esp+32] mov ecx, [esp+36] mov edx, [esp+40] mov esi, [esp+44] mov ebp, [esp+48] int 80h pop ebp pop edi pop esi pop edx pop ecx pop ebx or eax, eax js .errno clc ret .errno: neg eax stc ret %else %macro system 0 int 80h %endmacro %endif Dealing with Other Portability Issues The above solutions can handle most cases of writing code portable between FreeBSD and Linux. Nevertheless, with some kernel services the differences are deeper. In that case, you need to write two different handlers for those particular system calls, and use conditional assembly. Luckily, most of your code does something other than calling the kernel, so usually you will only need a few such conditional sections in your code. Using a Library You can avoid portability issues in your main code altogether by writing a library of system calls. Create a separate library for FreeBSD, a different one for Linux, and yet other libraries for more operating systems. In your library, write a separate function (or procedure, if you prefer the traditional assembly language terminology) for each system call. Use the C calling convention of passing parameters. But still use EAX to pass the call number in. In that case, your FreeBSD library can be very simple, as many seemingly different functions can be just labels to the same code: sys.open: sys.close: [etc...] int 80h ret Your Linux library will require more different functions. But even here you can group system calls using the same number of parameters: sys.exit: sys.close: [etc... one-parameter functions] push ebx mov ebx, [esp+12] int 80h pop ebx jmp sys.return ... sys.return: or eax, eax js sys.err clc ret sys.err: neg eax stc ret The library approach may seem inconvenient at first because it requires you to produce a separate file your code depends on. But it has many advantages: For one, you only need to write it once and can use it for all your programs. You can even let other assembly language programmers use it, or perhaps use one written by someone else. But perhaps the greatest advantage of the library is that your code can be ported to other systems, even by other programmers, by simply writing a new library without any changes to your code. If you do not like the idea of having a library, you can at least place all your system calls in a separate assembly language file and link it with your main program. Here, again, all porters have to do is create a new object file to link with your main program. Using an Include File If you are releasing your software as (or with) source code, you can use macros and place them in a separate file, which you include in your code. Porters of your software will simply write a new include file. No library or external object file is necessary, yet your code is portable without any need to edit the code. This is the approach we will use throughout this chapter. We will name our include file system.inc, and add to it whenever we deal with a new system call. We can start our system.inc by declaring the standard file descriptors: %define stdin 0 %define stdout 1 %define stderr 2 Next, we create a symbolic name for each system call: %define SYS_nosys 0 %define SYS_exit 1 %define SYS_fork 2 %define SYS_read 3 %define SYS_write 4 ; [etc...] We add a short, non-global procedure with a long name, so we do not accidentally reuse the name in our code: section .text align 4 access.the.bsd.kernel: int 80h ret We create a macro which takes one argument, the syscall number: %macro system 1 mov eax, %1 call access.the.bsd.kernel %endmacro Finally, we create macros for each syscall. These macros take no arguments. %macro sys.exit 0 system SYS_exit %endmacro %macro sys.fork 0 system SYS_fork %endmacro %macro sys.read 0 system SYS_read %endmacro %macro sys.write 0 system SYS_write %endmacro ; [etc...] Go ahead, enter it into your editor and save it as system.inc. We will add more to it as we discuss more syscalls. Our First Program We are now ready for our first program, the mandatory Hello, World! 1: %include 'system.inc' 2: 3: section .data 4: hello db 'Hello, World!', 0Ah 5: hbytes equ $-hello 6: 7: section .text 8: global _start 9: _start: 10: push dword hbytes 11: push dword hello 12: push dword stdout 13: sys.write 14: 15: push dword 0 16: sys.exit Here is what it does: Line 1 includes the defines, the macros, and the code from system.inc. Lines 3-5 are the data: Line 3 starts the data section/segment. Line 4 contains the string "Hello, World!" followed by a new line (0Ah). Line 5 creates a constant that contains the length of the string from line 4 in bytes. Lines 7-16 contain the code. Note that FreeBSD uses the elf file format for its executables, which requires every program to start at the point labeled _start (or, more precisely, the linker expects that). This label has to be global. Lines 10-13 ask the system to write hbytes bytes of the hello string to stdout. Lines 15-16 ask the system to end the program with the return value of 0. The SYS_exit syscall never returns, so the code ends there. If you have come to Unix from MS DOS assembly language background, you may be used to writing directly to the video hardware. You will never have to worry about this in FreeBSD, or any other flavor of Unix. As far as you are concerned, you are writing to a file known as stdout. This can be the video screen, or a telnet terminal, or an actual file, or even the input of another program. Which one it is, is for the system to figure out. Assembling the Code Type the code (except the line numbers) in an editor, and save it in a file named hello.asm. You need nasm to assemble it. Installing <application>nasm</application> If you do not have nasm, type: &prompt.user; su Password:your root password &prompt.root; cd /usr/ports/devel/nasm &prompt.root; make install &prompt.root; exit &prompt.user; You may type make install clean instead of just make install if you do not want to keep nasm source code. Either way, FreeBSD will automatically download nasm from the Internet, compile it, and install it on your system. If your system is not FreeBSD, you need to get nasm from its home page. You can still use it to assemble FreeBSD code. Now you can assemble, link, and run the code: &prompt.user; nasm -f elf hello.asm &prompt.user; ld -s -o hello hello.o &prompt.user; ./hello Hello, World! &prompt.user; Writing Unix Filters A common type of Unix application is a filter—a program that reads data from the stdin, processes it somehow, then writes the result to stdout. In this chapter, we shall develop a simple filter, and learn how to read from stdin and write to stdout. This filter will convert each byte of its input into a hexadecimal number followed by a blank space. %include 'system.inc' section .data hex db '0123456789ABCDEF' buffer db 0, 0, ' ' section .text global _start _start: ; read a byte from stdin push dword 1 push dword buffer push dword stdin sys.read add esp, byte 12 or eax, eax je .done ; convert it to hex movzx eax, byte [buffer] mov edx, eax shr dl, 4 mov dl, [hex+edx] mov [buffer], dl and al, 0Fh mov al, [hex+eax] mov [buffer+1], al ; print it push dword 3 push dword buffer push dword stdout sys.write add esp, byte 12 jmp short _start .done: push dword 0 sys.exit In the data section we create an array called hex. It contains the 16 hexadecimal digits in ascending order. The array is followed by a buffer which we will use for both input and output. The first two bytes of the buffer are initially set to 0. This is where we will write the two hexadecimal digits (the first byte also is where we will read the input). The third byte is a space. The code section consists of four parts: Reading the byte, converting it to a hexadecimal number, writing the result, and eventually exiting the program. To read the byte, we ask the system to read one byte from stdin, and store it in the first byte of the buffer. The system returns the number of bytes read in EAX. This will be 1 while data is coming, or 0, when no more input data is available. Therefore, we check the value of EAX. If it is 0, we jump to .done, otherwise we continue. For simplicity sake, we are ignoring the possibility of an error condition at this time. The hexadecimal conversion reads the byte from the buffer into EAX, or actually just AL, while clearing the remaining bits of EAX to zeros. We also copy the byte to EDX because we need to convert the upper four bits (nibble) separately from the lower four bits. We store the result in the first two bytes of the buffer. Next, we ask the system to write the three bytes of the buffer, i.e., the two hexadecimal digits and the blank space, to stdout. We then jump back to the beginning of the program and process the next byte. Once there is no more input left, we ask the system to exit our program, returning a zero, which is the traditional value meaning the program was successful. Go ahead, and save the code in a file named hex.asm, then type the following (the ^D means press the control key and type D while holding the control key down): &prompt.user; nasm -f elf hex.asm &prompt.user; ld -s -o hex hex.o &prompt.user; ./hex Hello, World! 48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A Here I come! 48 65 72 65 20 49 20 63 6F 6D 65 21 0A ^D &prompt.user; If you are migrating to Unix from MS DOS, you may be wondering why each line ends with 0A instead of 0D 0A. This is because Unix does not use the cr/lf convention, but a "new line" convention, which is 0A in hexadecimal. Can we improve this? Well, for one, it is a bit confusing because once we have converted a line of text, our input no longer starts at the begining of the line. We can modify it to print a new line instead of a space after each 0A: %include 'system.inc' section .data hex db '0123456789ABCDEF' buffer db 0, 0, ' ' section .text global _start _start: mov cl, ' ' .loop: ; read a byte from stdin push dword 1 push dword buffer push dword stdin sys.read add esp, byte 12 or eax, eax je .done ; convert it to hex movzx eax, byte [buffer] mov [buffer+2], cl cmp al, 0Ah jne .hex mov [buffer+2], al .hex: mov edx, eax shr dl, 4 mov dl, [hex+edx] mov [buffer], dl and al, 0Fh mov al, [hex+eax] mov [buffer+1], al ; print it push dword 3 push dword buffer push dword stdout sys.write add esp, byte 12 jmp short .loop .done: push dword 0 sys.exit We have stored the space in the CL register. We can do this safely because, unlike Microsoft Windows, Unix system calls do not modify the value of any register they do not use to return a value in. That means we only need to set CL once. We have, therefore, added a new label .loop and jump to it for the next byte instead of jumping at _start. We have also added the .hex label so we can either have a blank space or a new line as the third byte of the buffer. Once you have changed hex.asm to reflect these changes, type: &prompt.user; nasm -f elf hex.asm &prompt.user; ld -s -o hex hex.o &prompt.user; ./hex Hello, World! 48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A Here I come! 48 65 72 65 20 49 20 63 6F 6D 65 21 0A ^D &prompt.user; That looks better. But this code is quite inefficient! We are making a system call for every single byte twice (once to read it, another time to write the output). Buffered Input and Output We can improve the efficiency of our code by buffering our input and output. We create an input buffer and read a whole sequence of bytes at one time. Then we fetch them one by one from the buffer. We also create an output buffer. We store our output in it until it is full. At that time we ask the kernel to write the contents of the buffer to stdout. The program ends when there is no more input. But we still need to ask the kernel to write the contents of our output buffer to stdout one last time, otherwise some of our output would make it to the output buffer, but never be sent out. Do not forget that, or you will be wondering why some of your output is missing. %include 'system.inc' %define BUFSIZE 2048 section .data hex db '0123456789ABCDEF' section .bss ibuffer resb BUFSIZE obuffer resb BUFSIZE section .text global _start _start: sub eax, eax sub ebx, ebx sub ecx, ecx mov edi, obuffer .loop: ; read a byte from stdin call getchar ; convert it to hex mov dl, al shr al, 4 mov al, [hex+eax] call putchar mov al, dl and al, 0Fh mov al, [hex+eax] call putchar mov al, ' ' cmp dl, 0Ah jne .put mov al, dl .put: call putchar jmp short .loop align 4 getchar: or ebx, ebx jne .fetch call read .fetch: lodsb dec ebx ret read: push dword BUFSIZE mov esi, ibuffer push esi push dword stdin sys.read add esp, byte 12 mov ebx, eax or eax, eax je .done sub eax, eax ret align 4 .done: call write ; flush output buffer push dword 0 sys.exit align 4 putchar: stosb inc ecx cmp ecx, BUFSIZE je write ret align 4 write: sub edi, ecx ; start of buffer push ecx push edi push dword stdout sys.write add esp, byte 12 sub eax, eax sub ecx, ecx ; buffer is empty now ret We now have a third section in the source code, named .bss. This section is not included in our executable file, and, therefore, cannot be initialized. We use resb instead of db. It simply reserves the requested size of uninitialized memory for our use. We take advantage of the fact that the system does not modify the registers: We use registers for what, otherwise, would have to be global variables stored in the .data section. This is also why the Unix convention of passing parameters to system calls on the stack is superior to the Microsoft convention of passing them in the registers: We can keep the registers for our own use. We use EDI and ESI as pointers to the next byte to be read from or written to. We use EBX and ECX to keep count of the number of bytes in the two buffers, so we know when to dump the output to, or read more input from, the system. Let us see how it works now: &prompt.user; nasm -f elf hex.asm &prompt.user; ld -s -o hex hex.o &prompt.user; ./hex Hello, World! Here I come! 48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A 48 65 72 65 20 49 20 63 6F 6D 65 21 0A ^D &prompt.user; Not what you expected? The program did not print the output until we pressed ^D. That is easy to fix by inserting three lines of code to write the output every time we have converted a new line to 0A. I have marked the three lines with > (do not copy the > in your hex.asm). %include 'system.inc' %define BUFSIZE 2048 section .data hex db '0123456789ABCDEF' section .bss ibuffer resb BUFSIZE obuffer resb BUFSIZE section .text global _start _start: sub eax, eax sub ebx, ebx sub ecx, ecx mov edi, obuffer .loop: ; read a byte from stdin call getchar ; convert it to hex mov dl, al shr al, 4 mov al, [hex+eax] call putchar mov al, dl and al, 0Fh mov al, [hex+eax] call putchar mov al, ' ' cmp dl, 0Ah jne .put mov al, dl .put: call putchar > cmp al, 0Ah > jne .loop > call write jmp short .loop align 4 getchar: or ebx, ebx jne .fetch call read .fetch: lodsb dec ebx ret read: push dword BUFSIZE mov esi, ibuffer push esi push dword stdin sys.read add esp, byte 12 mov ebx, eax or eax, eax je .done sub eax, eax ret align 4 .done: call write ; flush output buffer push dword 0 sys.exit align 4 putchar: stosb inc ecx cmp ecx, BUFSIZE je write ret align 4 write: sub edi, ecx ; start of buffer push ecx push edi push dword stdout sys.write add esp, byte 12 sub eax, eax sub ecx, ecx ; buffer is empty now ret Now, let us see how it works: &prompt.user; nasm -f elf hex.asm &prompt.user; ld -s -o hex hex.o &prompt.user; ./hex Hello, World! 48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A Here I come! 48 65 72 65 20 49 20 63 6F 6D 65 21 0A ^D &prompt.user; Not bad for a 644-byte executable, is it! This approach to buffered input/output still contains a hidden danger. I will discuss—and fix—it later, when I talk about the dark side of buffering. How to Unread a Character This may be a somewhat advanced topic, mostly of interest to programmers familiar with the theory of compilers. If you wish, you may skip to the next section, and perhaps read this later. While our sample program does not require it, more sophisticated filters often need to look ahead. In other words, they may need to see what the next character is (or even several characters). If the next character is of a certain value, it is part of the token currently being processed. Otherwise, it is not. For example, you may be parsing the input stream for a textual string (e.g., when implementing a language compiler): If a character is followed by another character, or perhaps a digit, it is part of the token you are processing. If it is followed by white space, or some other value, then it is not part of the current token. This presents an interesting problem: How to return the next character back to the input stream, so it can be read again later? One possible solution is to store it in a character variable, then set a flag. We can modify getchar to check the flag, and if it is set, fetch the byte from that variable instead of the input buffer, and reset the flag. But, of course, that slows us down. The C language has an ungetc() function, just for that purpose. Is there a quick way to implement it in our code? I would like you to scroll back up and take a look at the getchar procedure and see if you can find a nice and fast solution before reading the next paragraph. Then come back here and see my own solution. The key to returning a character back to the stream is in how we are getting the characters to start with: First we check if the buffer is empty by testing the value of EBX. If it is zero, we call the read procedure. If we do have a character available, we use lodsb, then decrease the value of EBX. The lodsb instruction is effectively identical to: mov al, [esi] inc esi The byte we have fetched remains in the buffer until the next time read is called. We do not know when that happens, but we do know it will not happen until the next call to getchar. Hence, to "return" the last-read byte back to the stream, all we have to do is decrease the value of ESI and increase the value of EBX: ungetc: dec esi inc ebx ret But, be careful! We are perfectly safe doing this if our look-ahead is at most one character at a time. If we are examining more than one upcoming character and call ungetc several times in a row, it will work most of the time, but not all the time (and will be tough to debug). Why? Because as long as getchar does not have to call read, all of the pre-read bytes are still in the buffer, and our ungetc works without a glitch. But the moment getchar calls read, the contents of the buffer change. We can always rely on ungetc working properly on the last character we have read with getchar, but not on anything we have read before that. If your program reads more than one byte ahead, you have at least two choices: If possible, modify the program so it only reads one byte ahead. This is the simplest solution. If that option is not available, first of all determine the maximum number of characters your program needs to return to the input stream at one time. Increase that number slightly, just to be sure, preferably to a multiple of 16—so it aligns nicely. Then modify the .bss section of your code, and create a small "spare" buffer right before your input buffer, something like this: section .bss resb 16 ; or whatever the value you came up with ibuffer resb BUFSIZE obuffer resb BUFSIZE You also need to modify your ungetc to pass the value of the byte to unget in AL: ungetc: dec esi inc ebx mov [esi], al ret With this modification, you can call ungetc up to 17 times in a row safely (the first call will still be within the buffer, the remaining 16 may be either within the buffer or within the "spare"). Command Line Arguments Our hex program will be more useful if it can read the names of an input and output file from its command line, i.e., if it can process the command line arguments. But... Where are they? Before a Unix system starts a program, it pushes some data on the stack, then jumps at the _start label of the program. Yes, I said jumps, not calls. That means the data can be accessed by reading [esp+offset], or by simply popping it. The value at the top of the stack contains the number of command line arguments. It is traditionally called argc, for "argument count." Command line arguments follow next, all argc of them. These are typically referred to as argv, for "argument value(s)." That is, we get argv[0], argv[1], ..., argv[argc-1]. These are not the actual arguments, but pointers to arguments, i.e., memory addresses of the actual arguments. The arguments themselves are NUL-terminated character strings. The argv list is followed by a NULL pointer, which is simply a 0. There is more, but this is enough for our purposes right now. If you have come from the MS DOS programming environment, the main difference is that each argument is in a separate string. The second difference is that there is no practical limit on how many arguments there can be. Armed with this knowledge, we are almost ready for the next version of hex.asm. First, however, we need to add a few lines to system.inc: First, we need to add two new entries to our list of system call numbers: %define SYS_open 5 %define SYS_close 6 Then we add two new macros at the end of the file: %macro sys.open 0 system SYS_open %endmacro %macro sys.close 0 system SYS_close %endmacro Here, then, is our modified source code: %include 'system.inc' %define BUFSIZE 2048 section .data fd.in dd stdin fd.out dd stdout hex db '0123456789ABCDEF' section .bss ibuffer resb BUFSIZE obuffer resb BUFSIZE section .text align 4 err: push dword 1 ; return failure sys.exit align 4 global _start _start: add esp, byte 8 ; discard argc and argv[0] pop ecx jecxz .init ; no more arguments ; ECX contains the path to input file push dword 0 ; O_RDONLY push ecx sys.open jc err ; open failed add esp, byte 8 mov [fd.in], eax pop ecx jecxz .init ; no more arguments ; ECX contains the path to output file push dword 420 ; file mode (644 octal) push dword 0200h | 0400h | 01h ; O_CREAT | O_TRUNC | O_WRONLY push ecx sys.open jc err add esp, byte 12 mov [fd.out], eax .init: sub eax, eax sub ebx, ebx sub ecx, ecx mov edi, obuffer .loop: ; read a byte from input file or stdin call getchar ; convert it to hex mov dl, al shr al, 4 mov al, [hex+eax] call putchar mov al, dl and al, 0Fh mov al, [hex+eax] call putchar mov al, ' ' cmp dl, 0Ah jne .put mov al, dl .put: call putchar cmp al, dl jne .loop call write jmp short .loop align 4 getchar: or ebx, ebx jne .fetch call read .fetch: lodsb dec ebx ret read: push dword BUFSIZE mov esi, ibuffer push esi push dword [fd.in] sys.read add esp, byte 12 mov ebx, eax or eax, eax je .done sub eax, eax ret align 4 .done: call write ; flush output buffer ; close files push dword [fd.in] sys.close push dword [fd.out] sys.close ; return success push dword 0 sys.exit align 4 putchar: stosb inc ecx cmp ecx, BUFSIZE je write ret align 4 write: sub edi, ecx ; start of buffer push ecx push edi push dword [fd.out] sys.write add esp, byte 12 sub eax, eax sub ecx, ecx ; buffer is empty now ret In our .data section we now have two new variables, fd.in and fd.out. We store the input and output file descriptors here. In the .text section we have replaced the references to stdin and stdout with [fd.in] and [fd.out]. The .text section now starts with a simple error handler, which does nothing but exit the program with a return value of 1. The error handler is before _start so we are within a short distance from where the errors occur. Naturally, the program execution still begins at _start. First, we remove argc and argv[0] from the stack: They are of no interest to us (in this program, that is). We pop argv[1] to ECX. This register is particularly suited for pointers, as we can handle NULL pointers with jecxz. If argv[1] is not NULL, we try to open the file named in the first argument. Otherwise, we continue the program as before: Reading from stdin, writing to stdout. If we fail to open the input file (e.g., it does not exist), we jump to the error handler and quit. If all went well, we now check for the second argument. If it is there, we open the output file. Otherwise, we send the output to stdout. If we fail to open the output file (e.g., it exists and we do not have the write permission), we, again, jump to the error handler. The rest of the code is the same as before, except we close the input and output files before exiting, and, as mentioned, we use [fd.in] and [fd.out]. Our executable is now a whopping 768 bytes long. Can we still improve it? Of course! Every program can be improved. Here are a few ideas of what we could do: Have our error handler print a message to stderr. Add error handlers to the read and write functions. Close stdin when we open an input file, stdout when we open an output file. Add command line switches, such as -i and -o, so we can list the input and output files in any order, or perhaps read from stdin and write to a file. Print a usage message if command line arguments are incorrect. I shall leave these enhancements as an exercise to the reader: You already know everything you need to know to implement them. Unix Environment An important Unix concept is the environment, which is defined by environment variables. Some are set by the system, others by you, yet others by the shell, or any program that loads another program. How to Find Environment Variables I said earlier that when a program starts executing, the stack contains argc followed by the NULL-terminated argv array, followed by something else. The "something else" is the environment, or, to be more precise, a NULL-terminated array of pointers to environment variables. This is often referred to as env. The structure of env is the same as that of argv, a list of memory addresses followed by a NULL (0). In this case, there is no "envc"—we figure out where the array ends by searching for the final NULL. The variables usually come in the name=value format, but sometimes the =value part may be missing. We need to account for that possibility. webvars I could just show you some code that prints the environment the same way the Unix env command does. But I thought it would be more interesting to write a simple assembly language CGI utility. CGI: A Quick Overview I have a detailed CGI tutorial on my web site, but here is a very quick overview of CGI: The web server communicates with the CGI program by setting environment variables. The CGI program sends its output to stdout. The web server reads it from there. It must start with an HTTP header followed by two blank lines. It then prints the HTML code, or whatever other type of data it is producing. While certain environment variables use standard names, others vary, depending on the web server. That makes webvars quite a useful diagnostic tool. The Code Our webvars program, then, must send out the HTTP header followed by some HTML mark-up. It then must read the environment variables one by one and send them out as part of the HTML page. The code follows. I placed comments and explanations right inside the code: ;;;;;;; webvars.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; Copyright (c) 2000 G. Adam Stanislav ; All rights reserved. ; ; Redistribution and use in source and binary forms, with or without ; modification, are permitted provided that the following conditions ; are met: ; 1. Redistributions of source code must retain the above copyright ; notice, this list of conditions and the following disclaimer. ; 2. Redistributions in binary form must reproduce the above copyright ; notice, this list of conditions and the following disclaimer in the ; documentation and/or other materials provided with the distribution. ; ; THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE ; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ; ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE ; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL ; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS ; OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) ; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT ; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY ; OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF ; SUCH DAMAGE. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; Version 1.0 ; ; Started: 8-Dec-2000 ; Updated: 8-Dec-2000 ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; %include 'system.inc' section .data http db 'Content-type: text/html', 0Ah, 0Ah db '<?xml version="1.0" encoding="UTF-8"?>', 0Ah db '<!DOCTYPE html PUBLIC "-//W3C/DTD XHTML Strict//EN" ' db '"DTD/xhtml1-strict.dtd">', 0Ah db '<html xmlns="http://www.w3.org/1999/xhtml" ' db 'xml.lang="en" lang="en">', 0Ah db '<head>', 0Ah db '<title>Web Environment</title>', 0Ah db '<meta name="author" content="G. Adam Stanislav" />', 0Ah db '</head>', 0Ah, 0Ah db '<body bgcolor="#ffffff" text="#000000" link="#0000ff" ' db 'vlink="#840084" alink="#0000ff">', 0Ah db '<div class="webvars">', 0Ah db '<h1>Web Environment</h1>', 0Ah db '<p>The following <b>environment variables</b> are defined ' db 'on this web server:</p>', 0Ah, 0Ah db '<table align="center" width="80" border="0" cellpadding="10" ' db 'cellspacing="0" class="webvars">', 0Ah httplen equ $-http left db '<tr>', 0Ah db '<td class="name"><tt>' leftlen equ $-left middle db '</tt></td>', 0Ah db '<td class="value"><tt><b>' midlen equ $-middle undef db '<i>(undefined)</i>' undeflen equ $-undef right db '</b></tt></td>', 0Ah db '</tr>', 0Ah rightlen equ $-right wrap db '</table>', 0Ah db '</div>', 0Ah db '</body>', 0Ah db '</html>', 0Ah, 0Ah wraplen equ $-wrap section .text global _start _start: ; First, send out all the http and xhtml stuff that is ; needed before we start showing the environment push dword httplen push dword http push dword stdout sys.write ; Now find how far on the stack the environment pointers ; are. We have 12 bytes we have pushed before "argc" mov eax, [esp+12] ; We need to remove the following from the stack: ; ; The 12 bytes we pushed for sys.write ; The 4 bytes of argc ; The EAX*4 bytes of argv ; The 4 bytes of the NULL after argv ; ; Total: ; 20 + eax * 4 ; ; Because stack grows down, we need to ADD that many bytes ; to ESP. lea esp, [esp+20+eax*4] cld ; This should already be the case, but let's be sure. ; Loop through the environment, printing it out .loop: pop edi or edi, edi ; Done yet? je near .wrap ; Print the left part of HTML push dword leftlen push dword left push dword stdout sys.write ; It may be tempting to search for the '=' in the env string next. ; But it is possible there is no '=', so we search for the ; terminating NUL first. mov esi, edi ; Save start of string sub ecx, ecx not ecx ; ECX = FFFFFFFF sub eax, eax repne scasb not ecx ; ECX = string length + 1 mov ebx, ecx ; Save it in EBX ; Now is the time to find '=' mov edi, esi ; Start of string mov al, '=' repne scasb not ecx add ecx, ebx ; Length of name push ecx push esi push dword stdout sys.write ; Print the middle part of HTML table code push dword midlen push dword middle push dword stdout sys.write ; Find the length of the value not ecx lea ebx, [ebx+ecx-1] ; Print "undefined" if 0 or ebx, ebx jne .value mov ebx, undeflen mov edi, undef .value: push ebx push edi push dword stdout sys.write ; Print the right part of the table row push dword rightlen push dword right push dword stdout sys.write ; Get rid of the 60 bytes we have pushed add esp, byte 60 ; Get the next variable jmp .loop .wrap: ; Print the rest of HTML push dword wraplen push dword wrap push dword stdout sys.write ; Return success push dword 0 sys.exit This code produces a 1,396-byte executable. Most of it is data, i.e., the HTML mark-up we need to send out. Assemble and link it as usual: &prompt.user; nasm -f elf webvars.asm &prompt.user; ld -s -o webvars webvars.o To use it, you need to upload webvars to your web server. Depending on how your web server is set up, you may have to store it in a special cgi-bin directory, or perhaps rename it with a .cgi extension. Then you need to use your browser to view its output. To see its output on my web server, please go to http://www.int80h.org/webvars/. If curious about the additional environment variables present in a password protected web directory, go to http://www.int80h.org/private/, using the name asm and password programmer. Working with Files We have already done some basic file work: We know how to open and close them, how to read and write them using buffers. But Unix offers much more functionality when it comes to files. We will examine some of it in this section, and end up with a nice file conversion utility. Indeed, let us start at the end, that is, with the file conversion utility. It always makes programming easier when we know from the start what the end product is supposed to do. One of the first programs I wrote for Unix was tuc, a text-to-Unix file converter. It converts a text file from other operating systems to a Unix text file. In other words, it changes from different kind of line endings to the newline convention of Unix. It saves the output in a different file. Optionally, it converts a Unix text file to a DOS text file. I have used tuc extensively, but always only to convert from some other OS to Unix, never the other way. I have always wished it would just overwrite the file instead of me having to send the output to a different file. Most of the time, I end up using it like this: &prompt.user; tuc myfile tempfile &prompt.user; mv tempfile myfile It would be nice to have a ftuc, i.e., fast tuc, and use it like this: &prompt.user; ftuc myfile In this chapter, then, we will write ftuc in assembly language (the original tuc is in C), and study various file-oriented kernel services in the process. At first sight, such a file conversion is very simple: All you have to do is strip the carriage returns, right? If you answered yes, think again: That approach will work most of the time (at least with MS DOS text files), but will fail occasionally. The problem is that not all non-Unix text files end their line with the carriage return / line feed sequence. Some use carriage returns without line feeds. Others combine several blank lines into a single carriage return followed by several line feeds. And so on. A text file converter, then, must be able to handle any possible line endings: carriage return / line feed carriage return line feed / carriage return line feed It should also handle files that use some kind of a combination of the above (e.g., carriage return followed by several line feeds). Finite State Machine The problem is easily solved by the use of a technique called finite state machine, originally developed by the designers of digital electronic circuits. A finite state machine is a digital circuit whose output is dependent not only on its input but on its previous input, i.e., on its state. The microprocessor is an example of a finite state machine: Our assembly language code is assembled to machine language in which some assembly language code produces a single byte of machine language, while others produce several bytes. As the microprocessor fetches the bytes from the memory one by one, some of them simply change its state rather than produce some output. When all the bytes of the op code are fetched, the microprocessor produces some output, or changes the value of a register, etc. Because of that, all software is essentially a sequence of state instructions for the microprocessor. Nevertheless, the concept of finite state machine is useful in software design as well. Our text file converter can be designed as a finite state machine with three possible states. We could call them states 0-2, but it will make our life easier if we give them symbolic names: ordinary cr lf Our program will start in the ordinary state. During this state, the program action depends on its input as follows: If the input is anything other than a carriage return or line feed, the input is simply passed on to the output. The state remains unchanged. If the input is a carriage return, the state is changed to cr. The input is then discarded, i.e., no output is made. If the input is a line feed, the state is changed to lf. The input is then discarded. Whenever we are in the cr state, it is because the last input was a carriage return, which was unprocessed. What our software does in this state again depends on the current input: If the input is anything other than a carriage return or line feed, output a line feed, then output the input, then change the state to ordinary. If the input is a carriage return, we have received two (or more) carriage returns in a row. We discard the input, we output a line feed, and leave the state unchanged. If the input is a line feed, we output the line feed and change the state to ordinary. Note that this is not the same as the first case above – if we tried to combine them, we would be outputting two line feeds instead of one. Finally, we are in the lf state after we have received a line feed that was not preceded by a carriage return. This will happen when our file already is in Unix format, or whenever several lines in a row are expressed by a single carriage return followed by several line feeds, or when line ends with a line feed / carriage return sequence. Here is how we need to handle our input in this state: If the input is anything other than a carriage return or line feed, we output a line feed, then output the input, then change the state to ordinary. This is exactly the same action as in the cr state upon receiving the same kind of input. If the input is a carriage return, we discard the input, we output a line feed, then change the state to ordinary. If the input is a line feed, we output the line feed, and leave the state unchanged. The Final State The above finite state machine works for the entire file, but leaves the possibility that the final line end will be ignored. That will happen whenever the file ends with a single carriage return or a single line feed. I did not think of it when I wrote tuc, just to discover that occasionally it strips the last line ending. This problem is easily fixed by checking the state after the entire file was processed. If the state is not ordinary, we simply need to output one last line feed. Now that we have expressed our algorithm as a finite state machine, we could easily design a dedicated digital electronic circuit (a "chip") to do the conversion for us. Of course, doing so would be considerably more expensive than writing an assembly language program. The Output Counter Because our file conversion program may be combining two characters into one, we need to use an output counter. We initialize it to 0, and increase it every time we send a character to the output. At the end of the program, the counter will tell us what size we need to set the file to. Implementing FSM in Software The hardest part of working with a finite state machine is analyzing the problem and expressing it as a finite state machine. That accomplished, the software almost writes itself. In a high-level language, such as C, there are several main approaches. One is to use a switch statement which chooses what function should be run. For example, switch (state) { default: case REGULAR: regular(inputchar); break; case CR: cr(inputchar); break; case LF: lf(inputchar); break; } Another approach is by using an array of function pointers, something like this: (output[state])(inputchar); Yet another is to have state be a function pointer, set to point at the appropriate function: (*state)(inputchar); This is the approach we will use in our program because it is very easy to do in assembly language, and very fast, too. We will simply keep the address of the right procedure in EBX, and then just issue: call ebx This is possibly faster than hardcoding the address in the code because the microprocessor does not have to fetch the address from the memory—it is already stored in one of its registers. I said possibly because with the caching modern microprocessors do, either way may be equally fast. Memory Mapped Files Because our program works on a single file, we cannot use the approach that worked for us before, i.e., to read from an input file and to write to an output file. Unix allows us to map a file, or a section of a file, into memory. To do that, we first need to open the file with the appropriate read/write flags. Then we use the mmap system call to map it into the memory. One nice thing about mmap is that it automatically works with virtual memory: We can map more of the file into the memory than we have physical memory available, yet still access it through regular memory op codes, such as mov, lods, and stos. Whatever changes we make to the memory image of the file will be written to the file by the system. We do not even have to keep the file open: As long as it stays mapped, we can read from it and write to it. The 32-bit Intel microprocessors can access up to four gigabytes of memory – physical or virtual. The FreeBSD system allows us to use up to a half of it for file mapping. For simplicity sake, in this tutorial we will only convert files that can be mapped into the memory in their entirety. There are probably not too many text files that exceed two gigabytes in size. If our program encounters one, it will simply display a message suggesting we use the original tuc instead. If you examine your copy of syscalls.master, you will find two separate syscalls named mmap. This is because of evolution of Unix: There was the traditional BSD mmap, syscall 71. That one was superceded by the POSIX mmap, syscall 197. The FreeBSD system supports both because older programs were written by using the original BSD version. But new software uses the POSIX version, which is what we will use. The syscalls.master file lists the POSIX version like this: 197 STD BSD { caddr_t mmap(caddr_t addr, size_t len, int prot, \ int flags, int fd, long pad, off_t pos); } This differs slightly from what mmap2 says. That is because mmap2 describes the C version. The difference is in the long pad argument, which is not present in the C version. However, the FreeBSD syscalls add a 32-bit pad after pushing a 64-bit argument. In this case, off_t is a 64-bit value. When we are finished working with a memory-mapped file, we unmap it with the munmap syscall: For an in-depth treatment of mmap, see W. Richard Stevens' Unix Network Programming, Volume 2, Chapter 12. Determining File Size Because we need to tell mmap how many bytes of the file to map into the memory, and because we want to map the entire file, we need to determine the size of the file. We can use the fstat syscall to get all the information about an open file that the system can give us. That includes the file size. Again, syscalls.master lists two versions of fstat, a traditional one (syscall 62), and a POSIX one (syscall 189). Naturally, we will use the POSIX version: 189 STD POSIX { int fstat(int fd, struct stat *sb); } This is a very straightforward call: We pass to it the address of a stat structure and the descriptor of an open file. It will fill out the contents of the stat structure. I do, however, have to say that I tried to declare the stat structure in the .bss section, and fstat did not like it: It set the carry flag indicating an error. After I changed the code to allocate the structure on the stack, everything was working fine. Changing the File Size Because our program may combine carriage return / line feed sequences into straight line feeds, our output may be smaller than our input. However, since we are placing our output into the same file we read the input from, we may have to change the size of the file. The ftruncate system call allows us to do just that. Despite its somewhat misleading name, the ftruncate system call can be used to both truncate the file (make it smaller) and to grow it. And yes, we will find two versions of ftruncate in syscalls.master, an older one (130), and a newer one (201). We will use the newer one: 201 STD BSD { int ftruncate(int fd, int pad, off_t length); } Please note that this one contains a int pad again. ftuc We now know everything we need to write ftuc. We start by adding some new lines in system.inc. First, we define some constants and structures, somewhere at or near the beginning of the file: ;;;;;;; open flags %define O_RDONLY 0 %define O_WRONLY 1 %define O_RDWR 2 ;;;;;;; mmap flags %define PROT_NONE 0 %define PROT_READ 1 %define PROT_WRITE 2 %define PROT_EXEC 4 ;; %define MAP_SHARED 0001h %define MAP_PRIVATE 0002h ;;;;;;; stat structure struc stat st_dev resd 1 ; = 0 st_ino resd 1 ; = 4 st_mode resw 1 ; = 8, size is 16 bits st_nlink resw 1 ; = 10, ditto st_uid resd 1 ; = 12 st_gid resd 1 ; = 16 st_rdev resd 1 ; = 20 st_atime resd 1 ; = 24 st_atimensec resd 1 ; = 28 st_mtime resd 1 ; = 32 st_mtimensec resd 1 ; = 36 st_ctime resd 1 ; = 40 st_ctimensec resd 1 ; = 44 st_size resd 2 ; = 48, size is 64 bits st_blocks resd 2 ; = 56, ditto st_blksize resd 1 ; = 64 st_flags resd 1 ; = 68 st_gen resd 1 ; = 72 st_lspare resd 1 ; = 76 st_qspare resd 4 ; = 80 endstruc We define the new syscalls: %define SYS_mmap 197 %define SYS_munmap 73 %define SYS_fstat 189 %define SYS_ftruncate 201 We add the macros for their use: %macro sys.mmap 0 system SYS_mmap %endmacro %macro sys.munmap 0 system SYS_munmap %endmacro %macro sys.ftruncate 0 system SYS_ftruncate %endmacro %macro sys.fstat 0 system SYS_fstat %endmacro And here is our code: ;;;;;;; Fast Text-to-Unix Conversion (ftuc.asm) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; Started: 21-Dec-2000 ;; Updated: 22-Dec-2000 ;; ;; Copyright 2000 G. Adam Stanislav. ;; All rights reserved. ;; ;;;;;;; v.1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; %include 'system.inc' section .data db 'Copyright 2000 G. Adam Stanislav.', 0Ah db 'All rights reserved.', 0Ah usg db 'Usage: ftuc filename', 0Ah usglen equ $-usg co db "ftuc: Can't open file.", 0Ah colen equ $-co fae db 'ftuc: File access error.', 0Ah faelen equ $-fae ftl db 'ftuc: File too long, use regular tuc instead.', 0Ah ftllen equ $-ftl mae db 'ftuc: Memory allocation error.', 0Ah maelen equ $-mae section .text align 4 memerr: push dword maelen push dword mae jmp short error align 4 toolong: push dword ftllen push dword ftl jmp short error align 4 facerr: push dword faelen push dword fae jmp short error align 4 cantopen: push dword colen push dword co jmp short error align 4 usage: push dword usglen push dword usg error: push dword stderr sys.write push dword 1 sys.exit align 4 global _start _start: pop eax ; argc pop eax ; program name pop ecx ; file to convert jecxz usage pop eax or eax, eax ; Too many arguments? jne usage ; Open the file push dword O_RDWR push ecx sys.open jc cantopen mov ebp, eax ; Save fd sub esp, byte stat_size mov ebx, esp ; Find file size push ebx push ebp ; fd sys.fstat jc facerr mov edx, [ebx + st_size + 4] ; File is too long if EDX != 0 ... or edx, edx jne near toolong mov ecx, [ebx + st_size] ; ... or if it is above 2 GB or ecx, ecx js near toolong ; Do nothing if the file is 0 bytes in size jecxz .quit ; Map the entire file in memory push edx push edx ; starting at offset 0 push edx ; pad push ebp ; fd push dword MAP_SHARED push dword PROT_READ | PROT_WRITE push ecx ; entire file size push edx ; let system decide on the address sys.mmap jc near memerr mov edi, eax mov esi, eax push ecx ; for SYS_munmap push edi ; Use EBX for state machine mov ebx, ordinary mov ah, 0Ah cld .loop: lodsb call ebx loop .loop cmp ebx, ordinary je .filesize ; Output final lf mov al, ah stosb inc edx .filesize: ; truncate file to new size push dword 0 ; high dword push edx ; low dword push eax ; pad push ebp sys.ftruncate ; close it (ebp still pushed) sys.close add esp, byte 16 sys.munmap .quit: push dword 0 sys.exit align 4 ordinary: cmp al, 0Dh je .cr cmp al, ah je .lf stosb inc edx ret align 4 .cr: mov ebx, cr ret align 4 .lf: mov ebx, lf ret align 4 cr: cmp al, 0Dh je .cr cmp al, ah je .lf xchg al, ah stosb inc edx xchg al, ah ; fall through .lf: stosb inc edx mov ebx, ordinary ret align 4 .cr: mov al, ah stosb inc edx ret align 4 lf: cmp al, ah je .lf cmp al, 0Dh je .cr xchg al, ah stosb inc edx xchg al, ah stosb inc edx mov ebx, ordinary ret align 4 .cr: mov ebx, ordinary mov al, ah ; fall through .lf: stosb inc edx ret Do not use this program on files stored on a disk formated by MS DOS or Windows. There seems to be a subtle bug in the FreeBSD code when using mmap on these drives mounted under FreeBSD: If the file is over a certain size, mmap will just fill the memory with zeros, and then copy them to the file overwriting its contents. One-Pointed Mind As a student of Zen, I like the idea of a one-pointed mind: Do one thing at a time, and do it well. This, indeed, is very much how Unix works as well. While a typical Windows application is attempting to do everything imaginable (and is, therefore, riddled with bugs), a typical Unix program does only one thing, and it does it well. The typical Unix user then essentially assembles his own applications by writing a shell script which combines the various existing programs by piping the output of one program to the input of another. When writing your own Unix software, it is generally a good idea to see what parts of the problem you need to solve can be handled by existing programs, and only write your own programs for that part of the problem that you do not have an existing solution for. CSV I will illustrate this principle with a specific real-life example I was faced with recently: I needed to extract the 11th field of each record from a database I downloaded from a web site. The database was a CSV file, i.e., a list of comma-separated values. That is quite a standard format for sharing data among people who may be using different database software. The first line of the file contains the list of various fields separated by commas. The rest of the file contains the data listed line by line, with values separated by commas. I tried awk, using the comma as a separator. But because several lines contained a quoted comma, awk was extracting the wrong field from those lines. Therefore, I needed to write my own software to extract the 11th field from the CSV file. However, going with the Unix spirit, I only needed to write a simple filter that would do the following: Remove the first line from the file; Change all unquoted commas to a different character; Remove all quotation marks. Strictly speaking, I could use sed to remove the first line from the file, but doing so in my own program was very easy, so I decided to do it and reduce the size of the pipeline. At any rate, writing a program like this took me about 20 minutes. Writing a program that extracts the 11th field from the CSV file would take a lot longer, and I could not reuse it to extract some other field from some other database. This time I decided to let it do a little more work than a typical tutorial program would: It parses its command line for options; It displays proper usage if it finds wrong arguments; It produces meaningful error messages. Here is its usage message: Usage: csv [-t<delim>] [-c<comma>] [-p] [-o <outfile>] [-i <infile>] All parameters are optional, and can appear in any order. The -t parameter declares what to replace the commas with. The tab is the default here. For example, -t; will replace all unquoted commas with semicolons. I did not need the -c option, but it may come in handy in the future. It lets me declare that I want a character other than a comma replaced with something else. For example, -c@ will replace all at signs (useful if you want to split a list of email addresses to their user names and domains). The -p option preserves the first line, i.e., it does not delete it. By default, we delete the first line because in a CSV file it contains the field names rather than data. The -i and -o options let me specify the input and the output files. Defaults are stdin and stdout, so this is a regular Unix filter. I made sure that both -i filename and -ifilename are accepted. I also made sure that only one input and one output files may be specified. To get the 11th field of each record, I can now do: &prompt.user; csv '-t;' data.csv | awk '-F;' '{print $11}' The code stores the options (except for the file descriptors) in EDX: The comma in DH, the new separator in DL, and the flag for the -p option in the highest bit of EDX, so a check for its sign will give us a quick decision what to do. Here is the code: ;;;;;;; csv.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; Convert a comma-separated file to a something-else separated file. ; ; Started: 31-May-2001 ; Updated: 1-Jun-2001 ; ; Copyright (c) 2001 G. Adam Stanislav ; All rights reserved. ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; %include 'system.inc' %define BUFSIZE 2048 section .data fd.in dd stdin fd.out dd stdout usg db 'Usage: csv [-t<delim>] [-c<comma>] [-p] [-o <outfile>] [-i <infile>]', 0Ah usglen equ $-usg iemsg db "csv: Can't open input file", 0Ah iemlen equ $-iemsg oemsg db "csv: Can't create output file", 0Ah oemlen equ $-oemsg section .bss ibuffer resb BUFSIZE obuffer resb BUFSIZE section .text align 4 ierr: push dword iemlen push dword iemsg push dword stderr sys.write push dword 1 ; return failure sys.exit align 4 oerr: push dword oemlen push dword oemsg push dword stderr sys.write push dword 2 sys.exit align 4 usage: push dword usglen push dword usg push dword stderr sys.write push dword 3 sys.exit align 4 global _start _start: add esp, byte 8 ; discard argc and argv[0] mov edx, (',' << 8) | 9 .arg: pop ecx or ecx, ecx je near .init ; no more arguments ; ECX contains the pointer to an argument cmp byte [ecx], '-' jne usage inc ecx mov ax, [ecx] .o: cmp al, 'o' jne .i ; Make sure we are not asked for the output file twice cmp dword [fd.out], stdout jne usage ; Find the path to output file - it is either at [ECX+1], ; i.e., -ofile -- ; or in the next argument, ; i.e., -o file inc ecx or ah, ah jne .openoutput pop ecx jecxz usage .openoutput: push dword 420 ; file mode (644 octal) push dword 0200h | 0400h | 01h ; O_CREAT | O_TRUNC | O_WRONLY push ecx sys.open jc near oerr add esp, byte 12 mov [fd.out], eax jmp short .arg .i: cmp al, 'i' jne .p ; Make sure we are not asked twice cmp dword [fd.in], stdin jne near usage ; Find the path to the input file inc ecx or ah, ah jne .openinput pop ecx or ecx, ecx je near usage .openinput: push dword 0 ; O_RDONLY push ecx sys.open jc near ierr ; open failed add esp, byte 8 mov [fd.in], eax jmp .arg .p: cmp al, 'p' jne .t or ah, ah jne near usage or edx, 1 << 31 jmp .arg .t: cmp al, 't' ; redefine output delimiter jne .c or ah, ah je near usage mov dl, ah jmp .arg .c: cmp al, 'c' jne near usage or ah, ah je near usage mov dh, ah jmp .arg align 4 .init: sub eax, eax sub ebx, ebx sub ecx, ecx mov edi, obuffer ; See if we are to preserve the first line or edx, edx js .loop .firstline: ; get rid of the first line call getchar cmp al, 0Ah jne .firstline .loop: ; read a byte from stdin call getchar ; is it a comma (or whatever the user asked for)? cmp al, dh jne .quote ; Replace the comma with a tab (or whatever the user wants) mov al, dl .put: call putchar jmp short .loop .quote: cmp al, '"' jne .put ; Print everything until you get another quote or EOL. If it ; is a quote, skip it. If it is EOL, print it. .qloop: call getchar cmp al, '"' je .loop cmp al, 0Ah je .put call putchar jmp short .qloop align 4 getchar: or ebx, ebx jne .fetch call read .fetch: lodsb dec ebx ret read: jecxz .read call write .read: push dword BUFSIZE mov esi, ibuffer push esi push dword [fd.in] sys.read add esp, byte 12 mov ebx, eax or eax, eax je .done sub eax, eax ret align 4 .done: call write ; flush output buffer ; close files push dword [fd.in] sys.close push dword [fd.out] sys.close ; return success push dword 0 sys.exit align 4 putchar: stosb inc ecx cmp ecx, BUFSIZE je write ret align 4 write: jecxz .ret ; nothing to write sub edi, ecx ; start of buffer push ecx push edi push dword [fd.out] sys.write add esp, byte 12 sub eax, eax sub ecx, ecx ; buffer is empty now .ret: ret Much of it is taken from hex.asm above. But there is one important difference: I no longer call write whenever I am outputing a line feed. Yet, the code can be used interactively. I have found a better solution for the interactive problem since I first started writing this chapter. I wanted to make sure each line is printed out separately only when needed. After all, there is no need to flush out every line when used non-interactively. The new solution I use now is to call write every time I find the input buffer empty. That way, when running in the interactive mode, the program reads one line from the user's keyboard, processes it, and sees its input buffer is empty. It flushes its output and reads the next line. The Dark Side of Buffering This change prevents a mysterious lockup in a very specific case. I refer to it as the dark side of buffering, mostly because it presents a danger that is not quite obvious. It is unlikely to happen with a program like the csv above, so let us consider yet another filter: In this case we expect our input to be raw data representing color values, such as the red, green, and blue intensities of a pixel. Our output will be the negative of our input. Such a filter would be very simple to write. Most of it would look just like all the other filters we have written so far, so I am only going to show you its inner loop: .loop: call getchar not al ; Create a negative call putchar jmp short .loop Because this filter works with raw data, it is unlikely to be used interactively. But it could be called by image manipulation software. And, unless it calls write before each call to read, chances are it will lock up. Here is what might happen: The image editor will load our filter using the C function popen(). It will read the first row of pixels from a bitmap or pixmap. It will write the first row of pixels to the pipe leading to the fd.in of our filter. Our filter will read each pixel from its input, turn it to a negative, and write it to its output buffer. Our filter will call getchar to fetch the next pixel. getchar will find an empty input buffer, so it will call read. read will call the SYS_read system call. The kernel will suspend our filter until the image editor sends more data to the pipe. The image editor will read from the other pipe, connected to the fd.out of our filter so it can set the first row of the output image before it sends us the second row of the input. The kernel suspends the image editor until it receives some output from our filter, so it can pass it on to the image editor. At this point our filter waits for the image editor to send it more data to process, while the image editor is waiting for our filter to send it the result of the processing of the first row. But the result sits in our output buffer. The filter and the image editor will continue waiting for each other forever (or, at least, until they are killed). Our software has just entered a race condition. This problem does not exist if our filter flushes its output buffer before asking the kernel for more input data. Using the <acronym>FPU</acronym> Strangely enough, most of assembly language literature does not even mention the existence of the FPU, or floating point unit, let alone discuss programming it. Yet, never does assembly language shine more than when we create highly optimized FPU code by doing things that can be done only in assembly language. Organization of the <acronym>FPU</acronym> The FPU consists of 8 80–bit floating–point registers. These are organized in a stack fashion—you can push a value on TOS (top of stack) and you can pop it. That said, the assembly language op codes are not push and pop because those are already taken. You can push a value on TOS by using fld, fild, and fbld. Several other op codes let you push many common constants—such as pi—on the TOS. Similarly, you can pop a value by using fst, fstp, fist, fistp, and fbstp. Actually, only the op codes that end with a p will literally pop the value, the rest will store it somewhere else without removing it from the TOS. We can transfer the data between the TOS and the computer memory either as a 32–bit, 64–bit, or 80–bit real, a 16–bit, 32–bit, or 64–bit integer, or an 80–bit packed decimal. The 80–bit packed decimal is a special case of binary coded decimal which is very convenient when converting between the ASCII representation of data and the internal data of the FPU. It allows us to use 18 significant digits. No matter how we represent data in the memory, the FPU always stores it in the 80–bit real format in its registers. Its internal precision is at least 19 decimal digits, so even if we choose to display results as ASCII in the full 18–digit precision, we are still showing correct results. We can perform mathematical operations on the TOS: We can calculate its sine, we can scale it (i.e., we can multiply or divide it by a power of 2), we can calculate its base–2 logarithm, and many other things. We can also multiply or divide it by, add it to, or subtract it from, any of the FPU registers (including itself). The official Intel op code for the TOS is st, and for the registers st(0)–st(7). st and st(0), then, refer to the same register. For whatever reasons, the original author of nasm has decided to use different op codes, namely st0–st7. In other words, there are no parentheses, and the TOS is always st0, never just st. The Packed Decimal Format The packed decimal format uses 10 bytes (80 bits) of memory to represent 18 digits. The number represented there is always an integer. You can use it to get decimal places by multiplying the TOS by a power of 10 first. The highest bit of the highest byte (byte 9) is the sign bit: If it is set, the number is negative, otherwise, it is positive. The rest of the bits of this byte are unused/ignored. The remaining 9 bytes store the 18 digits of the number: 2 digits per byte. The more significant digit is stored in the high nibble (4 bits), the less significant digit in the low nibble. That said, you might think that -1234567 would be stored in the memory like this (using hexadecimal notation): 80 00 00 00 00 00 01 23 45 67 Alas it is not! As with everything else of Intel make, even the packed decimal is little–endian. That means our -1234567 is stored like this: 67 45 23 01 00 00 00 00 00 80 Remember that, or you will be pulling your hair out in desperation! The book to read—if you can find it—is Richard Startz' 8087/80287/80387 for the IBM PC & Compatibles. Though it does seem to take the fact about the little–endian storage of the packed decimal for granted. I kid you not about the desperation of trying to figure out what was wrong with the filter I show below before it occurred to me I should try the little–endian order even for this type of data. Excursion to Pinhole Photography To write meaningful software, we must not only understand our programming tools, but also the field we are creating software for. Our next filter will help us whenever we want to build a pinhole camera, so, we need some background in pinhole photography before we can continue. The Camera The easiest way to describe any camera ever built is as some empty space enclosed in some lightproof material, with a small hole in the enclosure. The enclosure is usually sturdy (e.g., a box), though sometimes it is flexible (the bellows). It is quite dark inside the camera. However, the hole lets light rays in through a single point (though in some cases there may be several). These light rays form an image, a representation of whatever is outside the camera, in front of the hole. If some light sensitive material (such as film) is placed inside the camera, it can capture the image. The hole often contains a lens, or a lens assembly, often called the objective. The Pinhole But, strictly speaking, the lens is not necessary: The original cameras did not use a lens but a pinhole. Even today, pinholes are used, both as a tool to study how cameras work, and to achieve a special kind of image. The image produced by the pinhole is all equally sharp. Or blurred. There is an ideal size for a pinhole: If it is either larger or smaller, the image loses its sharpness. Focal Length This ideal pinhole diameter is a function of the square root of focal length, which is the distance of the pinhole from the film. D = PC * sqrt(FL) In here, D is the ideal diameter of the pinhole, FL is the focal length, and PC is a pinhole constant. According to Jay Bender, its value is 0.04, while Kenneth Connors has determined it to be 0.037. Others have proposed other values. Plus, this value is for the daylight only: Other types of light will require a different constant, whose value can only be determined by experimentation. The F–Number The f–number is a very useful measure of how much light reaches the film. A light meter can determine that, for example, to expose a film of specific sensitivity with f5.6 may require the exposure to last 1/1000 sec. It does not matter whether it is a 35–mm camera, or a 6x9cm camera, etc. As long as we know the f–number, we can determine the proper exposure. The f–number is easy to calculate: F = FL / D In other words, the f–number equals the focal length divided by the diameter of the pinhole. It also means a higher f–number either implies a smaller pinhole or a larger focal distance, or both. That, in turn, implies, the higher the f–number, the longer the exposure has to be. Furthermore, while pinhole diameter and focal distance are one–dimensional measurements, both, the film and the pinhole, are two–dimensional. That means that if you have measured the exposure at f–number A as t, then the exposure at f–number B is: t * (B / A)² Normalized F–Number While many modern cameras can change the diameter of their pinhole, and thus their f–number, quite smoothly and gradually, such was not always the case. To allow for different f–numbers, cameras typically contained a metal plate with several holes of different sizes drilled to them. Their sizes were chosen according to the above formula in such a way that the resultant f–number was one of standard f–numbers used on all cameras everywhere. For example, a very old Kodak Duaflex IV camera in my possession has three such holes for f–numbers 8, 11, and 16. A more recently made camera may offer f–numbers of 2.8, 4, 5.6, 8, 11, 16, 22, and 32 (as well as others). These numbers were not chosen arbitrarily: They all are powers of the square root of 2, though they may be rounded somewhat. The F–Stop A typical camera is designed in such a way that setting any of the normalized f–numbers changes the feel of the dial. It will naturally stop in that position. Because of that, these positions of the dial are called f–stops. Since the f–numbers at each stop are powers of the square root of 2, moving the dial by 1 stop will double the amount of light required for proper exposure. Moving it by 2 stops will quadruple the required exposure. Moving the dial by 3 stops will require the increase in exposure 8 times, etc. Designing the Pinhole Software We are now ready to decide what exactly we want our pinhole software to do. Processing Program Input Since its main purpose is to help us design a working pinhole camera, we will use the focal length as the input to the program. This is something we can determine without software: Proper focal length is determined by the size of the film and by the need to shoot "regular" pictures, wide angle pictures, or telephoto pictures. Most of the programs we have written so far worked with individual characters, or bytes, as their input: The hex program converted individual bytes into a hexadecimal number, the csv program either let a character through, or deleted it, or changed it to a different character, etc. One program, ftuc used the state machine to consider at most two input bytes at a time. But our pinhole program cannot just work with individual characters, it has to deal with larger syntactic units. For example, if we want the program to calculate the pinhole diameter (and other values we will discuss later) at the focal lengths of 100 mm, 150 mm, and 210 mm, we may want to enter something like this: 100, 150, 210 Our program needs to consider more than a single byte of input at a time. When it sees the first 1, it must understand it is seeing the first digit of a decimal number. When it sees the 0 and the other 0, it must know it is seeing more digits of the same number. When it encounters the first comma, it must know it is no longer receiving the digits of the first number. It must be able to convert the digits of the first number into the value of 100. And the digits of the second number into the value of 150. And, of course, the digits of the third number into the numeric value of 210. We need to decide what delimiters to accept: Do the input numbers have to be separated by a comma? If so, how do we treat two numbers separated by something else? Personally, I like to keep it simple. Something either is a number, so I process it. Or it is not a number, so I discard it. I don't like the computer complaining about me typing in an extra character when it is obvious that it is an extra character. Duh! Plus, it allows me to break up the monotony of computing and type in a query instead of just a number: What is the best pinhole diameter for the focal length of 150? There is no reason for the computer to spit out a number of complaints: Syntax error: What Syntax error: is Syntax error: the Syntax error: best Et cetera, et cetera, et cetera. Secondly, I like the # character to denote the start of a comment which extends to the end of the line. This does not take too much effort to code, and lets me treat input files for my software as executable scripts. In our case, we also need to decide what units the input should come in: We choose millimeters because that is how most photographers measure the focus length. Finally, we need to decide whether to allow the use of the decimal point (in which case we must also consider the fact that much of the world uses a decimal comma). In our case allowing for the decimal point/comma would offer a false sense of precision: There is little if any noticeable difference between the focus lengths of 50 and 51, so allowing the user to input something like 50.5 is not a good idea. This is my opinion, mind you, but I am the one writing this program. You can make other choices in yours, of course. Offering Options The most important thing we need to know when building a pinhole camera is the diameter of the pinhole. Since we want to shoot sharp images, we will use the above formula to calculate the pinhole diameter from focal length. As experts are offering several different values for the PC constant, we will need to have the choice. It is traditional in Unix programming to have two main ways of choosing program parameters, plus to have a default for the time the user does not make a choice. Why have two ways of choosing? One is to allow a (relatively) permanent choice that applies automatically each time the software is run without us having to tell it over and over what we want it to do. The permanent choices may be stored in a configuration file, typically found in the user's home directory. The file usually has the same name as the application but is started with a dot. Often "rc" is added to the file name. So, ours could be ~/.pinhole or ~/.pinholerc. (The ~/ means current user's home directory.) The configuration file is used mostly by programs that have many configurable parameters. Those that have only one (or a few) often use a different method: They expect to find the parameter in an environment variable. In our case, we might look at an environment variable named PINHOLE. Usually, a program uses one or the other of the above methods. Otherwise, if a configuration file said one thing, but an environment variable another, the program might get confused (or just too complicated). Because we only need to choose one such parameter, we will go with the second method and search the environment for a variable named PINHOLE. The other way allows us to make ad hoc decisions: "Though I usually want you to use 0.039, this time I want 0.03872." In other words, it allows us to override the permanent choice. This type of choice is usually done with command line parameters. Finally, a program always needs a default. The user may not make any choices. Perhaps he does not know what to choose. Perhaps he is "just browsing." Preferably, the default will be the value most users would choose anyway. That way they do not need to choose. Or, rather, they can choose the default without an additional effort. Given this system, the program may find conflicting options, and handle them this way: If it finds an ad hoc choice (e.g., command line parameter), it should accept that choice. It must ignore any permanent choice and any default. Otherwise, if it finds a permanent option (e.g., an environment variable), it should accept it, and ignore the default. Otherwise, it should use the default. We also need to decide what format our PC option should have. At first site, it seems obvious to use the PINHOLE=0.04 format for the environment variable, and -p0.04 for the command line. Allowing that is actually a security risk. The PC constant is a very small number. Naturally, we will test our software using various small values of PC. But what will happen if someone runs the program choosing a huge value? It may crash the program because we have not designed it to handle huge numbers. Or, we may spend more time on the program so it can handle huge numbers. We might do that if we were writing commercial software for computer illiterate audience. Or, we might say, "Tough! The user should know better."" Or, we just may make it impossible for the user to enter a huge number. This is the approach we will take: We will use an implied 0. prefix. In other words, if the user wants 0.04, we will expect him to type -p04, or set PINHOLE=04 in his environment. So, if he says -p9999999, we will interpret it as 0.9999999—still ridiculous but at least safer. Secondly, many users will just want to go with either Bender's constant or Connors' constant. To make it easier on them, we will interpret -b as identical to -p04, and -c as identical to -p037. The Output We need to decide what we want our software to send to the output, and in what format. Since our input allows for an unspecified number of focal length entries, it makes sense to use a traditional database–style output of showing the result of the calculation for each focal length on a separate line, while separating all values on one line by a tab character. Optionally, we should also allow the user to specify the use of the CSV format we have studied earlier. In this case, we will print out a line of comma–separated names describing each field of every line, then show our results as before, but substituting a comma for the tab. We need a command line option for the CSV format. We cannot use -c because that already means use Connors' constant. For some strange reason, many web sites refer to CSV files as "Excel spreadsheet" (though the CSV format predates Excel). We will, therefore, use the -e switch to inform our software we want the output in the CSV format. We will start each line of the output with the focal length. This may sound repetitious at first, especially in the interactive mode: The user types in the focal length, and we are repeating it. But the user can type several focal lengths on one line. The input can also come in from a file or from the output of another program. In that case the user does not see the input at all. By the same token, the output can go to a file which we will want to examine later, or it could go to the printer, or become the input of another program. So, it makes perfect sense to start each line with the focal length as entered by the user. No, wait! Not as entered by the user. What if the user types in something like this: 00000000150 Clearly, we need to strip those leading zeros. So, we might consider reading the user input as is, converting it to binary inside the FPU, and printing it out from there. But... What if the user types something like this: 17459765723452353453534535353530530534563507309676764423 Ha! The packed decimal FPU format lets us input 18–digit numbers. But the user has entered more than 18 digits. How do we handle that? Well, we could modify our code to read the first 18 digits, enter it to the FPU, then read more, multiply what we already have on the TOS by 10 raised to the number of additional digits, then add to it. Yes, we could do that. But in this program it would be ridiculous (in a different one it may be just the thing to do): Even the circumference of the Earth expressed in millimeters only takes 11 digits. Clearly, we cannot build a camera that large (not yet, anyway). So, if the user enters such a huge number, he is either bored, or testing us, or trying to break into the system, or playing games—doing anything but designing a pinhole camera. What will we do? We will slap him in the face, in a manner of speaking: 17459765723452353453534535353530530534563507309676764423 ??? ??? ??? ??? ??? To achieve that, we will simply ignore any leading zeros. Once we find a non–zero digit, we will initialize a counter to 0 and start taking three steps: Send the digit to the output. Append the digit to a buffer we will use later to produce the packed decimal we can send to the FPU. Increase the counter. Now, while we are taking these three steps, we also need to watch out for one of two conditions: If the counter grows above 18, we stop appending to the buffer. We continue reading the digits and sending them to the output. If, or rather when, the next input character is not a digit, we are done inputting for now. Incidentally, we can simply discard the non–digit, unless it is a #, which we must return to the input stream. It starts a comment, so we must see it after we are done producing output and start looking for more input. That still leaves one possibility uncovered: If all the user enters is a zero (or several zeros), we will never find a non–zero to display. We can determine this has happened whenever our counter stays at 0. In that case we need to send 0 to the output, and perform another "slap in the face": 0 ??? ??? ??? ??? ??? Once we have displayed the focal length and determined it is valid (greater than 0 but not exceeding 18 digits), we can calculate the pinhole diameter. It is not by coincidence that pinhole contains the word pin. Indeed, many a pinhole literally is a pin hole, a hole carefully punched with the tip of a pin. That is because a typical pinhole is very small. Our formula gets the result in millimeters. We will multiply it by 1000, so we can output the result in microns. At this point we have yet another trap to face: Too much precision. Yes, the FPU was designed for high precision mathematics. But we are not dealing with high precision mathematics. We are dealing with physics (optics, specifically). Suppose we want to convert a truck into a pinhole camera (we would not be the first ones to do that!). Suppose its box is 12 meters long, so we have the focal length of 12000. Well, using Bender's constant, it gives us square root of 12000 multiplied by 0.04, which is 4.381780460 millimeters, or 4381.780460 microns. Put either way, the result is absurdly precise. Our truck is not exactly 12000 millimeters long. We did not measure its length with such a precision, so stating we need a pinhole with the diameter of 4.381780460 millimeters is, well, deceiving. 4.4 millimeters would do just fine. I "only" used ten digits in the above example. Imagine the absurdity of going for all 18! We need to limit the number of significant digits of our result. One way of doing it is by using an integer representing microns. So, our truck would need a pinhole with the diameter of 4382 microns. Looking at that number, we still decide that 4400 microns, or 4.4 millimeters is close enough. Additionally, we can decide that no matter how big a result we get, we only want to display four siginificant digits (or any other number of them, of course). Alas, the FPU does not offer rounding to a specific number of digits (after all, it does not view the numbers as decimal but as binary). We, therefore, must devise an algorithm to reduce the number of significant digits. Here is mine (I think it is awkward—if you know a better one, please, let me know): Initialize a counter to 0. While the number is greater than or equal to 10000, divide it by 10 and increase the counter. Output the result. While the counter is greater than 0, output 0 and decrease the counter. The 10000 is only good if you want four significant digits. For any other number of significant digits, replace 10000 with 10 raised to the number of significant digits. We will, then, output the pinhole diameter in microns, rounded off to four significant digits. At this point, we know the focal -length and the the pinhole +length and the pinhole diameter. That means we have enough information to also calculate the f–number. We will display the f–number, rounded to four significant digits. Chances are the f–number will tell us very little. To make it more meaningful, we can find the nearest normalized f–number, i.e., the nearest power of the square root of 2. We do that by multiplying the actual f–number by itself, which, of course, will give us its square. We will then calculate its base–2 logarithm, which is much easier to do than calculating the base–square–root–of–2 logarithm! We will round the result to the nearest integer. Next, we will raise 2 to the result. Actually, the FPU gives us a good shortcut to do that: We can use the fscale op code to "scale" 1, which is analogous to shifting an integer left. Finally, we calculate the square root of it all, and we have the nearest normalized f–number. If all that sounds overwhelming—or too much work, perhaps—it may become much clearer if you see the code. It takes 9 op codes altogether: fmul st0, st0 fld1 fld st1 fyl2x frndint fld1 fscale fsqrt fstp st1 The first line, fmul st0, st0, squares the contents of the TOS (top of the stack, same as st, called st0 by nasm). The fld1 pushes 1 on the TOS. The next line, fld st1, pushes the square back to the TOS. At this point the square is both in st and st(2) (it will become clear why we leave a second copy on the stack in a moment). st(1) contains 1. Next, fyl2x calculates base–2 logarithm of st multiplied by st(1). That is why we placed 1 on st(1) before. At this point, st contains the logarithm we have just calculated, st(1) contains the square of the actual f–number we saved for later. frndint rounds the TOS to the nearest integer. fld1 pushes a 1. fscale shifts the 1 we have on the TOS by the value in st(1), effectively raising 2 to st(1). Finally, fsqrt calculates the square root of the result, i.e., the nearest normalized f–number. We now have the nearest normalized f–number on the TOS, the base–2 logarithm rounded to the nearest integer in st(1), and the square of the actual f–number in st(2). We are saving the value in st(2) for later. But we do not need the contents of st(1) anymore. The last line, fstp st1, places the contents of st to st(1), and pops. As a result, what was st(1) is now st, what was st(2) is now st(1), etc. The new st contains the normalized f–number. The new st(1) contains the square of the actual f–number we have stored there for posterity. At this point, we are ready to output the normalized f–number. Because it is normalized, we will not round it off to four significant digits, but will send it out in its full precision. The normalized f-number is useful as long as it is reasonably small and can be found on our light meter. Otherwise we need a different method of determining proper exposure. Earlier we have figured out the formula of calculating proper exposure at an arbitrary f–number from that measured at a different f–number. Every light meter I have ever seen can determine proper exposure at f5.6. We will, therefore, calculate an "f5.6 multiplier," i.e., by how much we need to multiply the exposure measured at f5.6 to determine the proper exposure for our pinhole camera. From the above formula we know this factor can be calculated by dividing our f–number (the actual one, not the normalized one) by 5.6, and squaring the result. Mathematically, dividing the square of our f–number by the square of 5.6 will give us the same result. Computationally, we do not want to square two numbers when we can only square one. So, the first solution seems better at first. But... 5.6 is a constant. We do not have to have our FPU waste precious cycles. We can just tell it to divide the square of the f–number by whatever 5.6² equals to. Or we can divide the f–number by 5.6, and then square the result. The two ways now seem equal. But, they are not! Having studied the principles of photography above, we remember that the 5.6 is actually square root of 2 raised to the fifth power. An irrational number. The square of this number is exactly 32. Not only is 32 an integer, it is a power of 2. We do not need to divide the square of the f–number by 32. We only need to use fscale to shift it right by five positions. In the FPU lingo it means we will fscale it with st(1) equal to -5. That is much faster than a division. So, now it has become clear why we have saved the square of the f–number on the top of the FPU stack. The calculation of the f5.6 multiplier is the easiest calculation of this entire program! We will output it rounded to four significant digits. There is one more useful number we can calculate: The number of stops our f–number is from f5.6. This may help us if our f–number is just outside the range of our light meter, but we have a shutter which lets us set various speeds, and this shutter uses stops. Say, our f–number is 5 stops from f5.6, and the light meter says we should use 1/1000 sec. Then we can set our shutter speed to 1/1000 first, then move the dial by 5 stops. This calculation is quite easy as well. All we have to do is to calculate the base-2 logarithm of the f5.6 multiplier we had just calculated (though we need its value from before we rounded it off). We then output the result rounded to the nearest integer. We do not need to worry about having more than four significant digits in this one: The result is most likely to have only one or two digits anyway. FPU Optimizations In assembly language we can optimize the FPU code in ways impossible in high languages, including C. Whenever a C function needs to calculate a floating–point value, it loads all necessary variables and constants into FPU registers. It then does whatever calculation is required to get the correct result. Good C compilers can optimize that part of the code really well. It "returns" the value by leaving the result on the TOS. However, before it returns, it cleans up. Any variables and constants it used in its calculation are now gone from the FPU. It cannot do what we just did above: We calculated the square of the f–number and kept it on the stack for later use by another function. We knew we would need that value later on. We also knew we had enough room on the stack (which only has room for 8 numbers) to store it there. A C compiler has no way of knowing that a value it has on the stack will be required again in the very near future. Of course, the C programmer may know it. But the only recourse he has is to store the value in a memory variable. That means, for one, the value will be changed from the 80-bit precision used internally by the FPU to a C double (64 bits) or even single (32 bits). That also means that the value must be moved from the TOS into the memory, and then back again. Alas, of all FPU operations, the ones that access the computer memory are the slowest. So, whenever programming the FPU in assembly language, look for the ways of keeping intermediate results on the FPU stack. We can take that idea even further! In our program we are using a constant (the one we named PC). It does not matter how many pinhole diameters we are calculating: 1, 10, 20, 1000, we are always using the same constant. Therefore, we can optimize our program by keeping the constant on the stack all the time. Early on in our program, we are calculating the value of the above constant. We need to divide our input by 10 for every digit in the constant. It is much faster to multiply than to divide. So, at the start of our program, we divide 10 into 1 to obtain 0.1, which we then keep on the stack: Instead of dividing the input by 10 for every digit, we multiply it by 0.1. By the way, we do not input 0.1 directly, even though we could. We have a reason for that: While 0.1 can be expressed with just one decimal place, we do not know how many binary places it takes. We, therefore, let the FPU calculate its binary value to its own high precision. We are using other constants: We multiply the pinhole diameter by 1000 to convert it from millimeters to microns. We compare numbers to 10000 when we are rounding them off to four significant digits. So, we keep both, 1000 and 10000, on the stack. And, of course, we reuse the 0.1 when rounding off numbers to four digits. Last but not least, we keep -5 on the stack. We need it to scale the square of the f–number, instead of dividing it by 32. It is not by coincidence we load this constant last. That makes it the top of the stack when only the constants are on it. So, when the square of the f–number is being scaled, the -5 is at st(1), precisely where fscale expects it to be. It is common to create certain constants from scratch instead of loading them from the memory. That is what we are doing with -5: fld1 ; TOS = 1 fadd st0, st0 ; TOS = 2 fadd st0, st0 ; TOS = 4 fld1 ; TOS = 1 faddp st1, st0 ; TOS = 5 fchs ; TOS = -5 We can generalize all these optimizations into one rule: Keep repeat values on the stack! PostScript is a stack–oriented programming language. There are many more books available about PostScript than about the FPU assembly language: Mastering PostScript will help you master the FPU. <application>pinhole</application>—The Code ;;;;;;; pinhole.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; Find various parameters of a pinhole camera construction and use ; ; Started: 9-Jun-2001 ; Updated: 10-Jun-2001 ; ; Copyright (c) 2001 G. Adam Stanislav ; All rights reserved. ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; %include 'system.inc' %define BUFSIZE 2048 section .data align 4 ten dd 10 thousand dd 1000 tthou dd 10000 fd.in dd stdin fd.out dd stdout envar db 'PINHOLE=' ; Exactly 8 bytes, or 2 dwords long pinhole db '04,', ; Bender's constant (0.04) connors db '037', 0Ah ; Connors' constant usg db 'Usage: pinhole [-b] [-c] [-e] [-p <value>] [-o <outfile>] [-i <infile>]', 0Ah usglen equ $-usg iemsg db "pinhole: Can't open input file", 0Ah iemlen equ $-iemsg oemsg db "pinhole: Can't create output file", 0Ah oemlen equ $-oemsg pinmsg db "pinhole: The PINHOLE constant must not be 0", 0Ah pinlen equ $-pinmsg toobig db "pinhole: The PINHOLE constant may not exceed 18 decimal places", 0Ah biglen equ $-toobig huhmsg db 9, '???' separ db 9, '???' sep2 db 9, '???' sep3 db 9, '???' sep4 db 9, '???', 0Ah huhlen equ $-huhmsg header db 'focal length in millimeters,pinhole diameter in microns,' db 'F-number,normalized F-number,F-5.6 multiplier,stops ' db 'from F-5.6', 0Ah headlen equ $-header section .bss ibuffer resb BUFSIZE obuffer resb BUFSIZE dbuffer resb 20 ; decimal input buffer bbuffer resb 10 ; BCD buffer section .text align 4 huh: call write push dword huhlen push dword huhmsg push dword [fd.out] sys.write add esp, byte 12 ret align 4 perr: push dword pinlen push dword pinmsg push dword stderr sys.write push dword 4 ; return failure sys.exit align 4 consttoobig: push dword biglen push dword toobig push dword stderr sys.write push dword 5 ; return failure sys.exit align 4 ierr: push dword iemlen push dword iemsg push dword stderr sys.write push dword 1 ; return failure sys.exit align 4 oerr: push dword oemlen push dword oemsg push dword stderr sys.write push dword 2 sys.exit align 4 usage: push dword usglen push dword usg push dword stderr sys.write push dword 3 sys.exit align 4 global _start _start: add esp, byte 8 ; discard argc and argv[0] sub esi, esi .arg: pop ecx or ecx, ecx je near .getenv ; no more arguments ; ECX contains the pointer to an argument cmp byte [ecx], '-' jne usage inc ecx mov ax, [ecx] inc ecx .o: cmp al, 'o' jne .i ; Make sure we are not asked for the output file twice cmp dword [fd.out], stdout jne usage ; Find the path to output file - it is either at [ECX+1], ; i.e., -ofile -- ; or in the next argument, ; i.e., -o file or ah, ah jne .openoutput pop ecx jecxz usage .openoutput: push dword 420 ; file mode (644 octal) push dword 0200h | 0400h | 01h ; O_CREAT | O_TRUNC | O_WRONLY push ecx sys.open jc near oerr add esp, byte 12 mov [fd.out], eax jmp short .arg .i: cmp al, 'i' jne .p ; Make sure we are not asked twice cmp dword [fd.in], stdin jne near usage ; Find the path to the input file or ah, ah jne .openinput pop ecx or ecx, ecx je near usage .openinput: push dword 0 ; O_RDONLY push ecx sys.open jc near ierr ; open failed add esp, byte 8 mov [fd.in], eax jmp .arg .p: cmp al, 'p' jne .c or ah, ah jne .pcheck pop ecx or ecx, ecx je near usage mov ah, [ecx] .pcheck: cmp ah, '0' jl near usage cmp ah, '9' ja near usage mov esi, ecx jmp .arg .c: cmp al, 'c' jne .b or ah, ah jne near usage mov esi, connors jmp .arg .b: cmp al, 'b' jne .e or ah, ah jne near usage mov esi, pinhole jmp .arg .e: cmp al, 'e' jne near usage or ah, ah jne near usage mov al, ',' mov [huhmsg], al mov [separ], al mov [sep2], al mov [sep3], al mov [sep4], al jmp .arg align 4 .getenv: ; If ESI = 0, we did not have a -p argument, ; and need to check the environment for "PINHOLE=" or esi, esi jne .init sub ecx, ecx .nextenv: pop esi or esi, esi je .default ; no PINHOLE envar found ; check if this envar starts with 'PINHOLE=' mov edi, envar mov cl, 2 ; 'PINHOLE=' is 2 dwords long rep cmpsd jne .nextenv ; Check if it is followed by a digit mov al, [esi] cmp al, '0' jl .default cmp al, '9' jbe .init ; fall through align 4 .default: ; We got here because we had no -p argument, ; and did not find the PINHOLE envar. mov esi, pinhole ; fall through align 4 .init: sub eax, eax sub ebx, ebx sub ecx, ecx sub edx, edx mov edi, dbuffer+1 mov byte [dbuffer], '0' ; Convert the pinhole constant to real .constloop: lodsb cmp al, '9' ja .setconst cmp al, '0' je .processconst jb .setconst inc dl .processconst: inc cl cmp cl, 18 ja near consttoobig stosb jmp short .constloop align 4 .setconst: or dl, dl je near perr finit fild dword [tthou] fld1 fild dword [ten] fdivp st1, st0 fild dword [thousand] mov edi, obuffer mov ebp, ecx call bcdload .constdiv: fmul st0, st2 loop .constdiv fld1 fadd st0, st0 fadd st0, st0 fld1 faddp st1, st0 fchs ; If we are creating a CSV file, ; print header cmp byte [separ], ',' jne .bigloop push dword headlen push dword header push dword [fd.out] sys.write .bigloop: call getchar jc near done ; Skip to the end of the line if you got '#' cmp al, '#' jne .num call skiptoeol jmp short .bigloop .num: ; See if you got a number cmp al, '0' jl .bigloop cmp al, '9' ja .bigloop ; Yes, we have a number sub ebp, ebp sub edx, edx .number: cmp al, '0' je .number0 mov dl, 1 .number0: or dl, dl ; Skip leading 0's je .nextnumber push eax call putchar pop eax inc ebp cmp ebp, 19 jae .nextnumber mov [dbuffer+ebp], al .nextnumber: call getchar jc .work cmp al, '#' je .ungetc cmp al, '0' jl .work cmp al, '9' ja .work jmp short .number .ungetc: dec esi inc ebx .work: ; Now, do all the work or dl, dl je near .work0 cmp ebp, 19 jae near .toobig call bcdload ; Calculate pinhole diameter fld st0 ; save it fsqrt fmul st0, st3 fld st0 fmul st5 sub ebp, ebp ; Round off to 4 significant digits .diameter: fcom st0, st7 fstsw ax sahf jb .printdiameter fmul st0, st6 inc ebp jmp short .diameter .printdiameter: call printnumber ; pinhole diameter ; Calculate F-number fdivp st1, st0 fld st0 sub ebp, ebp .fnumber: fcom st0, st6 fstsw ax sahf jb .printfnumber fmul st0, st5 inc ebp jmp short .fnumber .printfnumber: call printnumber ; F number ; Calculate normalized F-number fmul st0, st0 fld1 fld st1 fyl2x frndint fld1 fscale fsqrt fstp st1 sub ebp, ebp call printnumber ; Calculate time multiplier from F-5.6 fscale fld st0 ; Round off to 4 significant digits .fmul: fcom st0, st6 fstsw ax sahf jb .printfmul inc ebp fmul st0, st5 jmp short .fmul .printfmul: call printnumber ; F multiplier ; Calculate F-stops from 5.6 fld1 fxch st1 fyl2x sub ebp, ebp call printnumber mov al, 0Ah call putchar jmp .bigloop .work0: mov al, '0' call putchar align 4 .toobig: call huh jmp .bigloop align 4 done: call write ; flush output buffer ; close files push dword [fd.in] sys.close push dword [fd.out] sys.close finit ; return success push dword 0 sys.exit align 4 skiptoeol: ; Keep reading until you come to cr, lf, or eof call getchar jc done cmp al, 0Ah jne .cr ret .cr: cmp al, 0Dh jne skiptoeol ret align 4 getchar: or ebx, ebx jne .fetch call read .fetch: lodsb dec ebx clc ret read: jecxz .read call write .read: push dword BUFSIZE mov esi, ibuffer push esi push dword [fd.in] sys.read add esp, byte 12 mov ebx, eax or eax, eax je .empty sub eax, eax ret align 4 .empty: add esp, byte 4 stc ret align 4 putchar: stosb inc ecx cmp ecx, BUFSIZE je write ret align 4 write: jecxz .ret ; nothing to write sub edi, ecx ; start of buffer push ecx push edi push dword [fd.out] sys.write add esp, byte 12 sub eax, eax sub ecx, ecx ; buffer is empty now .ret: ret align 4 bcdload: ; EBP contains the number of chars in dbuffer push ecx push esi push edi lea ecx, [ebp+1] lea esi, [dbuffer+ebp-1] shr ecx, 1 std mov edi, bbuffer sub eax, eax mov [edi], eax mov [edi+4], eax mov [edi+2], ax .loop: lodsw sub ax, 3030h shl al, 4 or al, ah mov [edi], al inc edi loop .loop fbld [bbuffer] cld pop edi pop esi pop ecx sub eax, eax ret align 4 printnumber: push ebp mov al, [separ] call putchar ; Print the integer at the TOS mov ebp, bbuffer+9 fbstp [bbuffer] ; Check the sign mov al, [ebp] dec ebp or al, al jns .leading ; We got a negative number (should never happen) mov al, '-' call putchar .leading: ; Skip leading zeros mov al, [ebp] dec ebp or al, al jne .first cmp ebp, bbuffer jae .leading ; We are here because the result was 0. ; Print '0' and return mov al, '0' jmp putchar .first: ; We have found the first non-zero. ; But it is still packed test al, 0F0h jz .second push eax shr al, 4 add al, '0' call putchar pop eax and al, 0Fh .second: add al, '0' call putchar .next: cmp ebp, bbuffer jb .done mov al, [ebp] push eax shr al, 4 add al, '0' call putchar pop eax and al, 0Fh add al, '0' call putchar dec ebp jmp short .next .done: pop ebp or ebp, ebp je .ret .zeros: mov al, '0' call putchar dec ebp jne .zeros .ret: ret The code follows the same format as all the other filters we have seen before, with one subtle exception:
We are no longer assuming that the end of input implies the end of things to do, something we took for granted in the character–oriented filters. This filter does not process characters. It processes a language (albeit a very simple one, consisting only of numbers). When we have no more input, it can mean one of two things: We are done and can quit. This is the same as before. The last character we have read was a digit. We have stored it at the end of our ASCII–to–float conversion buffer. We now need to convert the contents of that buffer into a number and write the last line of our output. For that reason, we have modified our getchar and our read routines to return with the carry flag clear whenever we are fetching another character from the input, or the carry flag set whenever there is no more input. Of course, we are still using assembly language magic to do that! Take a good look at getchar. It always returns with the carry flag clear. Yet, our main code relies on the carry flag to tell it when to quit—and it works. The magic is in read. Whenever it receives more input from the system, it just returns to getchar, which fetches a character from the input buffer, clears the carry flag and returns. But when read receives no more input from the system, it does not return to getchar at all. Instead, the add esp, byte 4 op code adds 4 to ESP, sets the carry flag, and returns. So, where does it return to? Whenever a program uses the call op code, the microprocessor pushes the return address, i.e., it stores it on the top of the stack (not the FPU stack, the system stack, which is in the memory). When a program uses the ret op code, the microprocessor pops the return value from the stack, and jumps to the address that was stored there. But since we added 4 to ESP (which is the stack pointer register), we have effectively given the microprocessor a minor case of amnesia: It no longer remembers it was getchar that called read. And since getchar never pushed anything before calling read, the top of the stack now contains the return address to whatever or whoever called getchar. As far as that caller is concerned, he called getchar, which returned with the carry flag set!
Other than that, the bcdload routine is caught up in the middle of a Lilliputian conflict between the Big–Endians and the Little–Endians. It is converting the text representation of a number into that number: The text is stored in the big–endian order, but the packed decimal is little–endian. To solve the conflict, we use the std op code early on. We cancel it with cld later on: It is quite important we do not call anything that may depend on the default setting of the direction flag while std is active. Everything else in this code should be quite clear, providing you have read the entire chapter that precedes it. It is a classical example of the adage that programming requires a lot of thought and only a little coding. Once we have thought through every tiny detail, the code almost writes itself. Using <application>pinhole</application> Because we have decided to make the program ignore any input except for numbers (and even those inside a comment), we can actually perform textual queries. We do not have to, but we can. In my humble opinion, forming a textual query, instead of having to follow a very strict syntax, makes software much more user friendly. Suppose we want to build a pinhole camera to use the 4x5 inch film. The standard focal length for that film is about 150mm. We want to fine–tune our focal length so the pinhole diameter is as round a number as possible. Let us also suppose we are quite comfortable with cameras but somewhat intimidated by computers. Rather than just have to type in a bunch of numbers, we want to ask a couple of questions. Our session might look like this: &prompt.user; pinhole Computer, What size pinhole do I need for the focal length of 150? 150 490 306 362 2930 12 Hmmm... How about 160? 160 506 316 362 3125 12 Let's make it 155, please. 155 498 311 362 3027 12 Ah, let's try 157... 157 501 313 362 3066 12 156? 156 500 312 362 3047 12 That's it! Perfect! Thank you very much! ^D We have found that while for the focal length of 150, our pinhole diameter should be 490 microns, or 0.49 mm, if we go with the almost identical focal length of 156 mm, we can get away with a pinhole diameter of exactly one half of a millimeter. Scripting Because we have chosen the # character to denote the start of a comment, we can treat our pinhole software as a scripting language. You have probably seen shell scripts that start with: #! /bin/sh ...or... #!/bin/sh ...because the blank space after the #! is optional. Whenever Unix is asked to run an executable file which starts with the #!, it assumes the file is a script. It adds the command to the rest of the first line of the script, and tries to execute that. Suppose now that we have installed pinhole in /usr/local/bin/, we can now write a script to calculate various pinhole diameters suitable for various focal lengths commonly used with the 120 film. The script might look something like this: #! /usr/local/bin/pinhole -b -i # Find the best pinhole diameter # for the 120 film ### Standard 80 ### Wide angle 30, 40, 50, 60, 70 ### Telephoto 100, 120, 140 Because 120 is a medium size film, we may name this file medium. We can set its permissions to execute, and run it as if it were a program: &prompt.user; chmod 755 medium &prompt.user; ./medium Unix will interpret that last command as: &prompt.user; /usr/local/bin/pinhole -b -i ./medium It will run that command and display: 80 358 224 256 1562 11 30 219 137 128 586 9 40 253 158 181 781 10 50 283 177 181 977 10 60 310 194 181 1172 10 70 335 209 181 1367 10 100 400 250 256 1953 11 120 438 274 256 2344 11 140 473 296 256 2734 11 Now, let us enter: &prompt.user; ./medium -c Unix will treat that as: &prompt.user; /usr/local/bin/pinhole -b -i ./medium -c That gives it two conflicting options: -b and -c (Use Bender's constant and use Connors' constant). We have programmed it so later options override early ones—our program will calculate everything using Connors' constant: 80 331 242 256 1826 11 30 203 148 128 685 9 40 234 171 181 913 10 50 262 191 181 1141 10 60 287 209 181 1370 10 70 310 226 256 1598 11 100 370 270 256 2283 11 120 405 296 256 2739 11 140 438 320 362 3196 12 We decide we want to go with Bender's constant after all. We want to save its values as a comma–separated file: &prompt.user; ./medium -b -e > bender &prompt.user; cat bender focal length in millimeters,pinhole diameter in microns,F-number,normalized F-number,F-5.6 multiplier,stops from F-5.6 80,358,224,256,1562,11 30,219,137,128,586,9 40,253,158,181,781,10 50,283,177,181,977,10 60,310,194,181,1172,10 70,335,209,181,1367,10 100,400,250,256,1953,11 120,438,274,256,2344,11 140,473,296,256,2734,11 &prompt.user; Caveats Assembly language programmers who "grew up" under MS DOS and Windows often tend to take shortcuts. Reading the keyboard scan codes and writing directly to video memory are two classical examples of practices which, under MS DOS are not frowned upon but considered the right thing to do. The reason? Both the PC BIOS and MS DOS are notoriously slow when performing these operations. You may be tempted to continue similar practices in the Unix environment. For example, I have seen a web site which explains how to access the keyboard scan codes on a popular Unix clone. That is generally a very bad idea in Unix environment! Let me explain why. Unix Is Protected For one thing, it may simply not be possible. Unix runs in protected mode. Only the kernel and device drivers are allowed to access hardware directly. Perhaps a particular Unix clone will let you read the keyboard scan codes, but chances are a real Unix operating system will not. And even if one version may let you do it, the next one may not, so your carefully crafted software may become a dinosaur overnight. Unix Is an Abstraction But there is a much more important reason not to try accessing the hardware directly (unless, of course, you are writing a device driver), even on the Unix-like systems that let you do it: Unix is an abstraction! There is a major difference in the philosophy of design between MS DOS and Unix. MS DOS was designed as a single-user system. It is run on a computer with a keyboard and a video screen attached directly to that computer. User input is almost guaranteed to come from that keyboard. Your program's output virtually always ends up on that screen. This is NEVER guaranteed under Unix. It is quite common for a Unix user to pipe and redirect program input and output: &prompt.user; program1 | program2 | program3 > file1 If you have written program2, your input does not come from the keyboard but from the output of program1. Similarly, your output does not go to the screen but becomes the input for program3 whose output, in turn, goes to file1. But there is more! Even if you made sure that your input comes from, and your output goes to, the terminal, there is no guarantee the terminal is a PC: It may not have its video memory where you expect it, nor may its keyboard be producing PC-style scan codes. It may be a Macintosh, or any other computer. Now you may be shaking your head: My software is in PC assembly language, how can it run on a Macintosh? But I did not say your software would be running on a Macintosh, only that its terminal may be a Macintosh. Under Unix, the terminal does not have to be directly attached to the computer that runs your software, it can even be on another continent, or, for that matter, on another planet. It is perfectly possible that a Macintosh user in Australia connects to a Unix system in North America (or anywhere else) via telnet. The software then runs on one computer, while the terminal is on a different computer: If you try to read the scan codes, you will get the wrong input! Same holds true about any other hardware: A file you are reading may be on a disk you have no direct access to. A camera you are reading images from may be on a space shuttle, connected to you via satellites. That is why under Unix you must never make any assumptions about where your data is coming from and going to. Always let the system handle the physical access to the hardware. These are caveats, not absolute rules. Exceptions are possible. For example, if a text editor has determined it is running on a local machine, it may want to read the scan codes directly for improved control. I am not mentioning these caveats to tell you what to do or what not to do, just to make you aware of certain pitfalls that await you if you have just arrived to Unix form MS DOS. Of course, creative people often break rules, and it is OK as long as they know they are breaking them and why. Acknowledgements This tutorial would never have been possible without the help of many experienced FreeBSD programmers from the FreeBSD hackers mailing list, many of whom have patiently answered my questions, and pointed me in the right direction in my attempts to explore the inner workings of Unix system programming in general and FreeBSD in particular. Thomas M. Sommers opened the door for me. His How do I write "Hello, world" in FreeBSD assembler? web page was my first encounter with an example of assembly language programming under FreeBSD. Jake Burkholder has kept the door open by willingly answering all of my questions and supplying me with example assembly language source code. Copyright © 2000-2001 G. Adam Stanislav. All rights reserved. diff --git a/en_US.ISO8859-1/books/fdp-primer/examples/appendix.sgml b/en_US.ISO8859-1/books/fdp-primer/examples/appendix.sgml index e093732098..0f6c30f197 100644 --- a/en_US.ISO8859-1/books/fdp-primer/examples/appendix.sgml +++ b/en_US.ISO8859-1/books/fdp-primer/examples/appendix.sgml @@ -1,355 +1,355 @@ Examples This appendix contains example SGML files and command lines you can use to convert them from one output format to another. If you have successfully installed the Documentation Project tools then you should - be able to to use these examples directly. + be able to use these examples directly. These examples are not exhaustive—they do not contain all the elements you might want to use, particularly in your document's front matter. For more examples of DocBook markup you should examine the SGML source for this and other documents, available in the CVSup doc collection, or available online starting at http://www.FreeBSD.org/cgi/cvsweb.cgi/doc/. To avoid confusion, these examples use the standard DocBook 3.1 DTD rather than the FreeBSD extension. They also use the stock stylesheets distributed by Norm Walsh, rather than any customisations made to those stylesheets by the FreeBSD Documentation Project. This makes them more useful as generic DocBook examples. DocBook <sgmltag>book</sgmltag> DocBook <sgmltag>book</sgmltag> An Example Book Your first name Your surname
foo@example.com
 2000 Copyright string here If your book has an abstract then it should go here. Preface Your book may have a preface, in which case it should be placed here. My first chapter This is the first chapter in my book. My first section This is the first section in my book. ]]> DocBook <sgmltag>article</sgmltag> DocBook <sgmltag>article</sgmltag>
An example article Your first name Your surname
foo@example.com
 2000 Copyright string here If your article has an abstract then it should go here. My first section This is the first section in my article. My first sub-section This is the first sub-section in my article.
]]> Producing formatted output This section assumes that you have installed the software listed in the textproc/docproj port, either by hand, or by using the port. Further, it is assumed that your software is installed in subdirectories under /usr/local/, and the directory where binaries have been installed is in your PATH. Adjust the paths as necessary for your system. Using Jade Converting DocBook to HTML (one large file) &prompt.user; jade -V nochunks \ -c /usr/local/share/sgml/docbook/dsssl/modular/catalog \ -c /usr/local/share/sgml/docbook/catalog \ -c /usr/local/share/sgml/jade/catalog \ -d /usr/local/share/sgml/docbook/dsssl/modular/html/docbook.dsl -t sgml file.sgml > file.html Specifies the nochunks parameter to the stylesheets, forcing all output to be written to STDOUT (using Norm Walsh's stylesheets). Specifies the catalogs that Jade will need to process. Three catalogs are required. The first is a catalog that contains information about the DSSSL stylesheets. The second contains information about the DocBook DTD. The third contains information specific to Jade. Specifies the full path to the DSSSL stylesheet that Jade will use when processing the document. Instructs Jade to perform a transformation from one DTD to another. In this case, the input is being transformed from the DocBook DTD to the HTML DTD. Specifies the file that Jade should process, and redirects output to the specified .html file. Converting DocBook to HTML (several small files) &prompt.user; jade \ -c /usr/local/share/sgml/docbook/dsssl/modular/catalog \ -c /usr/local/share/sgml/docbook/catalog \ -c /usr/local/share/sgml/jade/catalog \ -d /usr/local/share/sgml/docbook/dsssl/modular/html/docbook.dsl -t sgml file.sgml Specifies the catalogs that Jade will need to process. Three catalogs are required. The first is a catalog that contains information about the DSSSL stylesheets. The second contains information about the DocBook DTD. The third contains information specific to Jade. Specifies the full path to the DSSSL stylesheet that Jade will use when processing the document. Instructs Jade to perform a transformation from one DTD to another. In this case, the input is being transformed from the DocBook DTD to the HTML DTD. Specifies the file that Jade should process. The stylesheets determine how the individual HTML files will be named, and the name of the root file (i.e., the one that contains the start of the document. This example may still only generate one HTML file, depending on the structure of the document you are processing, and the stylesheet's rules for splitting output. Converting DocBook to Postscript The source SGML file must be converted to a TeX file. &prompt.user; jade -Vtex-backend \ -c /usr/local/share/sgml/docbook/dsssl/modular/catalog \ -c /usr/local/share/sgml/docbook/catalog \ -c /usr/local/share/sgml/jade/catalog \ -d /usr/local/share/sgml/docbook/dsssl/modular/print/docbook.dsl -t tex file.sgml Customises the stylesheets to use various options specific to producing output for TeX. Specifies the catalogs that Jade will need to process. Three catalogs are required. The first is a catalog that contains information about the DSSSL stylesheets. The second contains information about the DocBook DTD. The third contains information specific to Jade. Specifies the full path to the DSSSL stylesheet that Jade will use when processing the document. Instructs Jade to convert the output to TeX. The generated .tex file must now be run through tex, specifying the &jadetex macro package. &prompt.user; tex "&jadetex" file.tex You have to run tex at least three times. The first run processes the document, and determines areas of the document which are referenced from other parts of the document, for use in indexing, and so on. Do not be alarmed if you see warning messages such as LaTeX Warning: Reference `136' on page 5 undefined on input line 728. at this point. The second run reprocesses the document now that certain pieces of information are known (such as the document's page length). This allows index entries and other cross-references to be fixed up. The third pass performs any final cleanup necessary. The output from this stage will be file.dvi. Finally, run dvips to convert the .dvi file to Postscript. &prompt.user; dvips -o file.ps file.dvi Converting DocBook to PDF The first part of this process is identical to that when converting DocBook to Postscript, using the same jade command line (). When the .tex file has been generated you run TeX as before. However, use the &pdfjadetex macro package instead. &prompt.user; tex "&pdfjadetex" file.tex Again, run this command three times. This will generate file.pdf, which does not need to be processed any further. diff --git a/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml b/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml index ddf8ece3fa..e9cb2b13da 100644 --- a/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml +++ b/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml @@ -1,2563 +1,2563 @@ SGML Markup This chapter describes the three markup languages you will encounter when you contribute to the FreeBSD documentation project. Each section describes the markup language, and details the markup that you are likely to want to use, or that is already in use. These markup languages contain a large number of elements, and it can be confusing sometimes to know which element to use for a particular situation. This section goes through the elements you are most likely to need, and gives examples of how you would use them. This is not an exhaustive list of elements, since that would just reiterate the documentation for each language. The aim of this section is to list those elements more likely to be useful to you. If you have a question about how best to markup a particular piece of content, please post it to the FreeBSD Documentation Project mailing list freebsd-doc@FreeBSD.org. Inline vs. block In the remainder of this document, when describing elements, inline means that the element can occur within a block element, and does not cause a line break. A block element, by comparison, will cause a line break (and other processing) when it is encountered. HTML HTML, the HyperText Markup Language, is the markup language of choice on the World Wide Web. More information can be found at <URL:http://www.w3.org/>. HTML is used to markup pages on the FreeBSD web site. It should not (generally) be used to mark up other documention, since DocBook offers a far richer set of elements to choose from. Consequently, you will normally only encounter HTML pages if you are writing for the web site. HTML has gone through a number of versions, 1, 2, 3.0, 3.2, and the latest, 4.0 (available in both strict and loose variants). The HTML DTDs are available from the ports collection in the textproc/html port. They are automatically installed as part of the textproc/docproj port. Formal Public Identifier (FPI) There are a number of HTML FPIs, depending upon the version (also known as the level) of HTML that you want to declare your document to be compliant with. The majority of HTML documents on the FreeBSD web site comply with the loose version of HTML 4.0. PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" Sectional elements An HTML document is normally split in to two sections. The first section, called the head, contains meta-information about the document, such as its title, the name of the author, the parent document, and so on. The second section, the body, contains the content that will be displayed to the user. These sections are indicated with head and body elements respectively. These elements are contained within the top-level html element. Normal HTML document structure <html> <head> <title>The document's title</title> </head> <body> … </body> </html> Block elements Headings HTML allows you to denote headings in your document, at up to six different levels. The largest and most prominent heading is h1, then h2, continuing down to h6. The element's content is the text of the heading. <sgmltag>h1</sgmltag>, <sgmltag>h2</sgmltag>, etc. Use: First section

This is the heading for the first section

This is the heading for the first sub-section

This is the heading for the second section

]]> Generally, an HTML page should have one first level heading (h1). This can contain many second level headings (h2), which can in turn contain many third level headings. Each hn element should have the same element, but one further up the hierarchy, preceeding it. Leaving gaps in the numbering is to be avoided. Bad ordering of <sgmltag>h<replaceable>n</replaceable></sgmltag> elements Use: First section

Sub-section

]]> Paragraphs HTML supports a single paragraph element, p. <sgmltag>p</sgmltag> Use: This is a paragraph. It can contain just about any other element.

]]> Block quotations A block quotation is an extended quotation from another document that should not appear within the current paragraph. <sgmltag>blockquote</sgmltag> Use: A small excerpt from the US Constitution:

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
]]> Lists You can present the user with three types of lists, ordered, unordered, and definition. Typically, each entry in an ordered list will be numbered, while each entry in an unordered list will be preceded by a bullet point. Definition lists are composed of two sections for each entry. The first section is the term being defined, and the second section is the definition of the term. Ordered lists are indicated by the ol element, unordered lists by the ul element, and definition lists by the dl element. Ordered and unordered lists contain listitems, indicated by the li element. A listitem can contain textual content, or it may be further wrapped in one or more p elements. Definition lists contain definition terms (dt) and definition descriptions (dd). A definition term can only contain inline elements. A definition description can contain other block elements. <sgmltag>ul</sgmltag> and <sgmltag>ol</sgmltag> Use: An unordered list. Listitems will probably be preceeded by bullets.

  • First item
  • Second item
  • Third item

An ordered list, with list items consisting of multiple paragraphs. Each item (note: not each paragraph) will be numbered.

  1. This is the first item. It only has one paragraph.

  2. This is the first paragraph of the second item.

    This is the second paragraph of the second item.

  3. This is the first and only paragraph of the third item.

]]> Definition lists with <sgmltag>dl</sgmltag> Use:
Term 1

Paragraph 1 of definition 1.

Paragraph 2 of definition 1.

Term 2

Paragraph 1 of definition 2.

Term 3
Paragraph 1 of definition 3. Note that the <p> element is not required in the single paragraph case.
]]> Pre-formatted text You can indicate that text should be shown to the user exactly as it is in the file. Typically, this means that the text is shown in a fixed font, multiple spaces are not merged in to one, and line breaks in the text are significant. In order to do this, wrap the content in the pre element. <sgmltag>pre</sgmltag> You could use pre to mark up an e-mail message; From: nik@FreeBSD.org To: freebsd-doc@FreeBSD.org Subject: New documentation available There's a new copy of my primer for contributers to the FreeBSD Documentation Project available at Comments appreciated. N]]> Tables Most text-mode browsers (such as Lynx) do not render tables particularly effectively. If you are relying on the tabular display of your content, you should consider using alternative markup to prevent confusion. Mark up tabular information using the table element. A table consists of one or more table rows (tr), each containing one or more cells of table data (td). Each cell can contain other block elements, such as paragraphs or lists. It can also contain another table (this nesting can repeat indefinitely). If the cell only contains one paragraph then you do not need to include the p element. Simple use of <sgmltag>table</sgmltag> Use: This is a simple 2x2 table.

Top left cell Top right cell
Bottom left cell Bottom right cell
]]> A cell can span multiple rows and columns. To indicate this, add the rowspan and/or colspan attributes, with values indicating the number of rows of columns that should be spanned. Using <literal>rowspan</literal> Use: One tall thin cell on the left, two short cells next to it on the right.

Long and thin
Top cell Bottom cell
]]> Using <literal>colspan</literal> Use: One long cell on top, two short cells below it.

Top cell
Bottom left cell Bottom right cell
]]> Using <literal>rowspan</literal> and <literal>colspan</literal> together Use: On a 3x3 grid, the top left block is a 2x2 set of cells merged in to one. The other cells are normal.

Top left large cell Top right cell
Middle right cell
Bottom left cell Bottom middle cell Bottom right cell
]]> In-line elements Emphasising information You have two levels of emphasis available in HTML, em and strong. em is for a normal level of emphasis and strong indicates stronger emphasis. Typically, em is rendered in italic and strong is rendered in bold. This is not always the case, however, and you should not rely on it. <sgmltag>em</sgmltag> and <sgmltag>strong</sgmltag> Use: This has been emphasised, while this has been strongly emphasised.

]]> Bold and italics Because HTML includes presentational markup, you can also indicate that particular content should be rendered in bold or italic. The elements are b and i respectively. <sgmltag>b</sgmltag> and <sgmltag>i</sgmltag> This is in bold, while this is in italics.

]]> Indicating fixed pitch text If you have content that should be rendered in a fixed pitch (typewriter) typeface, use tt (for “teletype”). <sgmltag>tt</sgmltag> Use: This document was originally written by Nik Clayton, who can be reached by e-mail as nik@FreeBSD.org.

]]> Content size You can indicate that content should be shown in a larger or smaller font. There are three ways of doing this. Use big and small around the content you wish to change size. These tags can be nested, so <big><big>This is much bigger</big></big> is possible. Use font with the size attribute set to +1 or -1 respectively. This has the same effect as using big or small. However, the use of this approach is deprecated. Use font with the size attribute set to a number between 1 and 7. The default font size is 3. This approach is deprecated. <sgmltag>big</sgmltag>, <sgmltag>small</sgmltag>, and <sgmltag>font</sgmltag> The following fragments all do the same thing. This text is slightly smaller. But this text is slightly bigger.

This text is slightly smaller. But this text is slightly bigger

This text is slightly smaller. But this text is slightly bigger.

]]> Links Links are also in-line elements. Linking to other documents on the WWW In order to include a link to another document on the WWW you must know the URL of the document you want to link to. The link is indicated with a, and the href attribute contains the URL of the target document. The content of the element becomes the link, and is normally indicated to the user in some way (underlining, change of colour, different mouse cursor when over the link, and so on). Using <literal><a href="..."></literal> Use: More information is available at the FreeBSD web site.

]]> These links will take the user to the top of the chosen document. Linking to other parts of documents Linking to a point within another document (or within the same document) requires that the document author include anchors that you can link to. Anchors are indicated with a and the name attribute instead of href. Using <literal><a name="..."></literal> Use: This paragraph can be referenced in other links with the name para1.

]]> To link to a named part of a document, write a normal link to that document, but include the name of the anchor after a # symbol. Linking to a named part of another document Assume that the para1 example resides in a document called foo.html. More information can be found in the first paragraph of foo.html.

]]> If you are linking to a named anchor within the same document then you can omit the document's URL, and just include the name of the anchor (with the preceeding #). Linking to a named part of the same document Assume that the para1 example resides in this document More information can be found in the first paragraph of this document.

]]> DocBook DocBook was designed by the Davenport Group to be a DTD for writing technical documentation. As such, and unlike LinuxDoc and HTML, DocBook is very heavily oriented towards markup that describes what something is, rather than describing how it should be presented. <literal>formal</literal> vs. <literal>informal</literal> Some elements may exist in two forms, formal and informal. Typically, the formal version of the element will consist of a title followed by the information version of the element. The informal version will not have a title. The DocBook DTD is available from the ports collection in the textproc/docbook port. It is automatically installed as part of the textproc/docproj port. FreeBSD extensions The FreeBSD Documentation Project has extended the DocBook DTD by adding some new elements. These elements serve to make some of the markup more precise. Where a FreeBSD specific element is listed below it is clearly marked. Throughout the rest of this document, the term “DocBook” is used to mean the FreeBSD extended DocBook DTD. There is nothing about these extensions that is FreeBSD specific, it was just felt that they were useful enhancements for this particular project. Should anyone from any of the other *nix camps (NetBSD, OpenBSD, Linux, …) be interested in collaborating on a standard DocBook extension set, please get in touch with Nik Clayton nik@FreeBSD.org. The FreeBSD extensions are not (currently) in the ports collection. They are stored in the FreeBSD CVS tree, as doc/share/sgml/freebsd.dtd. Formal Public Identifier (FPI) In compliance with the DocBook guidelines for writing FPIs for DocBook customisations, the FPI for the FreeBSD extended DocBook DTD is; PUBLIC "-//FreeBSD//DTD DocBook V4.1-Based Extension//EN" Document structure DocBook allows you to structure your documentation in several ways. In the FreeBSD Documentation Project we are using two primary types of DocBook document: the book and the article. A book is organised into chapters. This is a mandatory requirement. There may be parts between the book and the chapter to provide another layer of organisation. The Handbook is arranged in this way. A chapter may (or may not) contain one or more sections. These are indicated with the sect1 element. If a section contains another section then use the sect2 element, and so on, up to sect5. Chapters and sections contain the remainder of the content. An article is simpler than a book, and does not use chapters. Instead, the content of an article is organised into one or more sections, using the same sect1 (and sect2 and so on) elements that are used in books. Obviously, you should consider the nature of the documentation you are writing in order to decide whether it is best marked up as a book or an article. Articles are well suited to information that does not need to be broken down into several chapters, and that is, relatively speaking, quite short, at up to 20-25 pages of content. Books are best suited to information that can be broken up into several chapters, possibly with appendices and similar content as well. The FreeBSD tutorials are all marked up as articles, while this document, the FreeBSD FAQ, and the FreeBSD Handbook are all marked up as books. Starting a book The content of the book is contained within the book element. As well as containing structural markup, this element can contain elements that include additional information about the book. This is either meta-information, used for reference purposes, or additional content used to produce a title page. This additional information should be contained within bookinfo. Boilerplate <sgmltag>book</sgmltag> with <sgmltag>bookinfo</sgmltag> <book> <bookinfo> <title>Your title here</title> <author> <firstname>Your first name</firstname> <surname>Your surname</surname> <affiliation> <address><email>Your e-mail address</email></address> </affiliation> </author> <copyright> <year>1998</year> <holder role="mailto:your e-mail address">Your name</holder> </copyright> <pubdate role="rcs">$Date$</pubdate> <releaseinfo>$Id$</releaseinfo> <abstract> <para>Include an abstract of the book's contents here.</para> </abstract> </bookinfo> … </book> Starting an article The content of the article is contained within the article element. As well as containing structural markup, this element can contain elements that include additional information about the article. This is either meta-information, used for reference purposes, or additional content used to produce a title page. This additional information should be contained within articleinfo. Boilerplate <sgmltag>article</sgmltag> with <sgmltag>articleinfo</sgmltag> <article> <articleinfo> <title>Your title here</title> <author> <firstname>Your first name</firstname> <surname>Your surname</surname> <affiliation> <address><email>Your e-mail address</email></address> </affiliation> </author> <copyright> <year>1998</year> <holder role="mailto:your e-mail address">Your name</holder> </copyright> <pubdate role="rcs">$Date$</pubdate> <releaseinfo>$Id$</releaseinfo> <abstract> <para>Include an abstract of the article's contents here.</para> </abstract> </articleinfo> … </article> Indicating chapters Use chapter to mark up your chapters. Each chapter has a mandatory title. Articles do not contain chapters, they are reserved for books. A simple chapter The chapter's title ... ]]> A chapter cannot be empty; it must contain elements in addition to title. If you need to include an empty chapter then just use an empty paragraph. Empty chapters This is an empty chapter ]]> Sections below chapters In books, chapters may (but do not need to) be broken up into sections, subsections, and so on. In articles, sections are the main structural element, and each article must contain at least one section. Use the sectn element. The n indicates the section number, which identifies the section level. The first sectn is sect1. You can have one or more of these in a chapter. They can contain one or more sect2 elements, and so on, down to sect5. Sections in chapters A sample chapter Some text in the chapter. First section (1.1) … Second section (1.2) First sub-section (1.2.1) First sub-sub-section (1.2.1.1) … Second sub-section (1.2.2) … ]]> This example includes section numbers in the section titles. You should not do this in your documents. Adding the section numbers is carried out the by the stylesheets (of which more later), and you do not need to manage them yourself. Subdividing using <sgmltag>part</sgmltag>s You can introduce another layer of organisation between book and chapter with one or more parts. This cannot be done in an article. Introduction Overview ... What is FreeBSD? ... History ... ]]> Block elements Paragraphs DocBook supports three types of paragraphs: formalpara, para, and simpara. Most of the time you will only need to use para. formalpara includes a title element, and simpara disallows some elements from within para. Stick with para. <sgmltag>para</sgmltag> Use: This is a paragraph. It can contain just about any other element. ]]> Appearance: This is a paragraph. It can contain just about any other element. Block quotations A block quotation is an extended quotation from another document that should not appear within the current paragraph. You will probably only need it infrequently. Blockquotes can optionally contain a title and an attribution (or they can be left untitled and unattributed). <sgmltag>blockquote</sgmltag> Use: A small excerpt from the US Constitution;
Preamble to the Constitution of the United States Copied from a web site somewhere We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
]]> Appearance:
Preamble to the Constitution of the United States Copied from a web site somewhere We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
Tips, notes, warnings, cautions, important information and sidebars. You may need to include extra information separate from the main body of the text. Typically this is “meta” information that the user should be aware of. Depending on the nature of the information, one of tip, note, warning, caution, and important should be used. Alternatively, if the information is related to the main text but is not one of the above, use sidebar. The circumstances in which to choose one of these elements over another is unclear. The DocBook documentation suggests; A Note is for information that should be heeded by all readers. An Important element is a variation on Note. A Caution is for information regarding possible data loss or software damage. A Warning is for information regarding possible hardware damage or injury to life or limb. <sgmltag>warning</sgmltag> Use: Installing FreeBSD may make you want to delete Windows from your harddisk. ]]> Installing FreeBSD may make you want to delete Windows from your harddisk. Lists and procedures You will often need to list pieces of information to the user, or present them with a number of steps that must be carried out in order to accomplish a particular goal. In order to do this, use itemizedlist, orderedlist, or procedureThere are other types of list element in DocBook, but we're not concerned with those at the moment. itemizedlist and orderedlist are similar to their counterparts in HTML, ul and ol. Each one consists of one or more listitem elements, and each listitem contains one or more block elements. The listitem elements are analagous to HTML's li tags. However, unlike HTML, they are required. procedure is slightly different. It consists of steps, which may in turn consists of more steps or substeps. Each step contains block elements. <sgmltag>itemizedlist</sgmltag>, <sgmltag>orderedlist</sgmltag>, and <sgmltag>procedure</sgmltag> Use: This is the first itemized item. This is the second itemized item. This is the first ordered item. This is the second ordered item. Do this. Then do this. And now do this. ]]> Appearance: This is the first itemized item. This is the second itemized item. This is the first ordered item. This is the second ordered item. Do this. Then do this. And now do this. Showing file samples If you want to show a fragment of a file (or perhaps a complete file) to the user, wrap it in the programlisting element. White space and line breaks within programlisting are significant. In particular, this means that the opening tag should appear on the same line as the first line of the output, and the closing tag should appear on the same line as the last line of the output, otherwise spurious blank lines may be included. <sgmltag>programlisting</sgmltag> Use: When you have finished, your program should look like this; #include <stdio.h> int main(void) { printf("hello, world\n"); }]]> Notice how the angle brackets in the #include line need to be referenced by their entities instead of being included literally. Appearance: When you have finished, your program should look like this; #include <stdio.h> int main(void) { printf("hello, world\n"); } Callouts A callout is a mechanism for referring back to an earlier piece of text or specific position within an earlier example without linking to it within the text. To do this, mark areas of interest in your example (programlisting, literallayout, or whatever) with the co element. Each element must have a unique id assigned to it. After the example include a calloutlist that refers back to the example and provides additional commentary. <sgmltag>co</sgmltag> and <sgmltag>calloutlist</sgmltag> When you have finished, your program should look like this; #include <stdio.h> int main(void) { printf("hello, world\n"); } Includes the standard IO header file. Specifies that main() returns an int. The printf() call that writes hello, world to standard output. ]]> Appearance: When you have finished, your program should look like this; #include <stdio.h> int main(void) { printf("hello, world\n"); } Includes the standard IO header file. Specifies that main() returns an int. The printf() call that writes hello, world to standard output. Tables Unlike HTML, you do not need to use tables for layout purposes, as the stylesheet handles those issues for you. Instead, just use tables for marking up tabular data. In general terms (and see the DocBook documentation for more detail) a table (which can be either formal or informal) consists of a table element. This contains at least one tgroup element, which specifies (as an attribute) the number of columns in this table group. Within the tablegroup you can then have one thead element, which contains elements for the table headings (column headings), and one tbody which contains the body of the table. Both tgroup and thead contain row elements, which in turn contain entry elements. Each entry element specifies one cell in the table. <sgmltag>informaltable</sgmltag> Use: This is column head 1 This is column head 2 Row 1, column 1 Row 1, column 2 Row 2, column 1 Row 2, column 2 ]]> Appearance: This is column head 1 This is column head 2 Row 1, column 1 Row 1, column 2 Row 2, column 1 Row 2, column 2 If you don't want a border around the table the frame attribute can be added to the informaltable element with a value of none (i.e., <informaltable frame="none">). Tables where <literal>frame="none"</literal> Appearance: This is column head 1 This is column head 2 Row 1, column 1 Row 1, column 2 Row 2, column 1 Row 2, column 2 Examples for the user to follow A lot of the time you need to show examples for the user to follow. Typically, these will consist of dialogs with the computer; the user types in a command, the user gets a response back, they type in another command, and so on. A number of distinct elements and entities come in to play here. screen Everything the user sees in this example will be on the computer screen, so the next element is screen. Within screen, white space is significant. prompt, &prompt.root; and &prompt.user; Some of the things the user will be seeing on the screen are prompts from the computer (either from the OS, command shell, or application. These should be marked up using prompt. As a special case, the two shell prompts for the normal user and the root user have been provided as entities. Every time you want to indicate the user is at a shell prompt, use one of &prompt.root; and &prompt.user; as necessary. They do not need to be inside prompt. &prompt.root; and &prompt.user; are FreeBSD extensions to DocBook, and are not part of the original DTD. userinput When displaying text that the user should type in, wrap it in userinput tags. It will probably be displayed differently to the user. <sgmltag>screen</sgmltag>, <sgmltag>prompt</sgmltag>, and <sgmltag>userinput</sgmltag> Use: &prompt.user; ls -1 foo1 foo2 foo3 &prompt.user; ls -1 | grep foo2 foo2 &prompt.user; su Password: &prompt.root; cat foo2 This is the file called 'foo2']]> Appearance: &prompt.user; ls -1 foo1 foo2 foo3 &prompt.user; ls -1 | grep foo2 foo2 &prompt.user; su Password: &prompt.root; cat foo2 This is the file called 'foo2' Even though we are displaying the contents of the file foo2, it is not marked up as programlisting. Reserve programlisting for showing fragments of files outside the context of user actions. In-line elements Emphasising information When you want to emphasise a particular word or phrase, use emphasis. This may be presented as italic, or bold, or might be spoken differently with a text-to-speech system. There is no way to change the presentation of the emphasis within your document, no equivalent of HTML's b and i. If the information you are presenting is important then consider presenting it in important rather than emphasis. <sgmltag>emphasis</sgmltag> Use: FreeBSD is without doubt the premiere Unix like operating system for the Intel architecture.]]> Appearance: FreeBSD is without doubt the premiere Unix like operating system for the Intel architecture. Applications, commands, options, and cites You will frequently want to refer to both applications and commands when writing for the Handbook. The distinction between them is simple: an application is the name for a suite (or possibly just 1) of programs that fulfil a particular task. A command is the name of a program that the user can run. In addition, you will occasionally need to list one or more of the options that a command might take. Finally, you will often want to list a command with its manual section number, in the “command(number)” format so common in Unix manuals. Mark up application names with application. When you want to list a command with its manual section number (which should be most of the time) the DocBook element is citerefentry. This will contain a further two elements, refentrytitle and manvolnum. The content of refentrytitle is the name of the command, and the content of manvolnum is the manual page section. This can be cumbersome to write, and so a series of general entities have been created to make this easier. Each entity takes the form &man.manual-page.manual-section;. The file that contains these entities is in doc/share/sgml/man-refs.ent, and can be referred to using this FPI: PUBLIC "-//FreeBSD//ENTITIES DocBook Manual Page Entities//EN" Therefore, the introduction to your documentation will probably look like this: <!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V4.1-Based Extension//EN" [ <!ENTITY % man PUBLIC "-//FreeBSD//ENTITIES DocBook Manual Page Entities//EN"> %man; … ]> Use command when you want to include a command name “in-line” but present it as something the user should type in. Use option to mark up a command's options. This can be confusing, and sometimes the choice is not always clear. Hopefully this example makes it clearer. Applications, commands, and options. Use: Sendmail is the most widely used Unix mail application. Sendmail includes the sendmail 8 , &man.mailq.8;, and &man.newaliases.8; programs. One of the command line parameters to sendmail 8 , , will display the current status of messages in the mail queue. Check this on the command line by running sendmail -bp.]]> Appearance: Sendmail is the most widely used Unix mail application. Sendmail includes the sendmail 8 , mailq 8 , and newaliases 8 programs. One of the command line parameters to sendmail 8 , , will display the current status of messages in the mail queue. Check this on the command line by running sendmail -bp. Notice how the &man.command.section; notation is easier to follow. Files, directories, extensions Whenever you wish to refer to the name of a file, a directory, or a file extension, use filename. <sgmltag>filename</sgmltag> Use: The SGML source for the Handbook in English can be found in /usr/doc/en/handbook/. The first file is called handbook.sgml in that directory. You should also see a Makefile and a number of files with a .ent extension.]]> Appearance: The SGML source for the Handbook in English can be found in /usr/doc/en/handbook/. The first file is called handbook.sgml in that directory. You should also see a Makefile and a number of files with a .ent extension. Devices FreeBSD extension These elements are part of the FreeBSD extension to DocBook, and do not exist in the original DocBook DTD. When referring to devices you have two choices. You can either refer to the device as it appears in /dev, or you can use the name of the device as it appears in the kernel. For this latter course, use devicename. Sometimes you will not have a choice. Some devices, such as networking cards, do not have entries in /dev, or the entries are markedly different from those entries. <sgmltag>devicename</sgmltag> Use: sio is used for serial communication in FreeBSD. sio manifests through a number of entries in /dev, including /dev/ttyd0 and /dev/cuaa0. By contrast, the networking devices, such as ed0 do not appear in /dev. In MS-DOS, the first floppy drive is referred to as a:. In FreeBSD it is /dev/fd0.]]> Appearance: sio is used for serial communication in FreeBSD. sio manifests through a number of entries in /dev, including /dev/ttyd0 and /dev/cuaa0. By contrast, the networking devices, such as ed0 do not appear in /dev. In MS-DOS, the first floppy drive is referred to as a:. In FreeBSD it is /dev/fd0. Hosts, domains, IP addresses, and so forth FreeBSD extension These elements are part of the FreeBSD extension to DocBook, and do not exist in the original DocBook DTD. You can markup identification information for networked computers (hosts) in several ways, depending on the nature of the information. All of them use hostid as the element, with the role attribute selecting the type of the marked up information. No role attribute, or role="hostname" With no role attribute (i.e., hostid...hostid the marked up information is the simple hostname, such as freefall or wcarchive. You can explicitly specify this with role="hostname". role="domainname" The text is a domain name, such as FreeBSD.org or ngo.org.uk. There is no hostname component. role="fqdn" The text is a Fully Qualified Domain Name, with both hostname and domain name parts. role="ipaddr" The text is an IP address, probably expressed as a dotted quad. role="ip6addr" The text is an IPv6 address. role="netmask" The text is a network mask, which might be expressed as a dotted quad, a hexadecimal string, or as a / followed by a number. role="mac" The text is an ethernet MAC address, expressed as a series of 2 digit hexadecimal numbers seperated by colons. <sgmltag>hostid</sgmltag> and roles Use: The local machine can always be referred to by the name localhost, which will have the IP address 127.0.0.1. The FreeBSD.org domain contains a number of different hosts, including freefall.FreeBSD.org and bento.FreeBSD.org. When adding an IP alias to an interface (using ifconfig) always use a netmask of 255.255.255.255 (which can also be expressed as 0xffffffff. The MAC address uniquely identifies every network card in in existence. A typical MAC address looks like 08:00:20:87:ef:d0.]]> Appearance: The local machine can always be referred to by the name localhost, which will have the IP address 127.0.0.1. The FreeBSD.org domain contains a number of different hosts, including freefall.FreeBSD.org and bento.FreeBSD.org. When adding an IP alias to an interface (using ifconfig) always use a netmask of 255.255.255.255 (which can also be expressed as 0xffffffff. The MAC address uniquely identifies every network card in existence. A typical MAC address looks like 08:00:20:87:ef:d0. Usernames FreeBSD extension These elements are part of the FreeBSD extension to DocBook, and do not exist in the original DocBook DTD. When you need to refer to a specific username, such as root or bin, use username. <sgmltag>username</sgmltag> Use: To carry out most system administration functions you will need to be root.]]> Appearance: To carry out most system administration functions you will need to be root. Describing <filename>Makefile</filename>s FreeBSD extension These elements are part of the FreeBSD extension to DocBook, and do not exist in the original DocBook DTD. Two elements exist to describe parts of Makefiles, maketarget and makevar. maketarget identifies a build target exported by a Makefile that can be given as a parameter to make. makevar identifies a variable that can be set (in the environment, on the make command line, or within the Makefile) to influence the process. <sgmltag>maketarget</sgmltag> and <sgmltag>makevar</sgmltag> Use: Two common targets in a Makefile are all and clean. Typically, invoking all will rebuild the application, and invoking clean will remove the temporary files (.o for example) created by the build process. clean may be controlled by a number of variables, including CLOBBER and RECURSE.]]> Appearance: Two common targets in a Makefile are all and clean. Typically, invoking all will rebuild the application, and invoking clean will remove the temporary files (.o for example) created by the build process. clean may be controlled by a number of variables, including CLOBBER and RECURSE. Literal text You will often need to include “literal” text in the Handbook. This is text that is excerpted from another file, or which should be copied from the Handbook into another file verbatim. Some of the time, programlisting will be sufficient to denote this text. programlisting is not always appropriate, particularly when you want to include a portion of a file “in-line” with the rest of the paragraph. On these occasions, use literal. <sgmltag>literal</sgmltag> Use: The maxusers 10 line in the kernel configuration file determines the size of many system tables, and is a rough guide to how many simultaneous logins the system will support.]]> Appearance: The maxusers 10 line in the kernel configuration file determines the size of many system tables, and is a rough guide to how many simultaneous logins the system will support. Showing items that the user <emphasis>must</emphasis> fill in There will often be times when you want to show the user what to do, or refer to a file, or command line, or similar, where the user can not simply copy the examples that you provide, but must instead include some information themselves. replaceable is designed for this eventuality. Use it inside other elements to indicate parts of that element's content that the user must replace. <sgmltag>replaceable</sgmltag> Use: &prompt.user; man command ]]> Appearance: &prompt.user; man command replaceable can be used in many different elements, including literal. This example also shows that replaceable should only be wrapped around the content that the user is meant to provide. The other content should be left alone. Use: The maxusers n line in the kernel configuration file determines the size of many system tables, and is a rough guide to how many simultaneous logins the system will support. For a desktop workstation, 32 is a good value for n.]]> Appearance: The maxusers n line in the kernel configuration file determines the size of many system tables, and is a rough guide to how many simultaneous logins the system will support. For a desktop workstation, 32 is a good value for n. Images Image support in the documentation is currently extremely experimental. I think the mechanisms described here are unlikely to change, but that's not guaranteed. You will also need to install the graphics/ImageMagick port, which is used to convert between the different image formats. This is a big port, and most of it is not required. However, while we're working on the Makefiles and other infrastructure it makes things easier. This port is not in the textproc/docproj meta port, you must install it by hand. The best example of what follows in practice is the en_US.ISO8859-1/articles/vm-design/ document. If you're unsure of the description that follows, take a look at the files in that directory to see how everything hangs togther. Experiment with creating different formatted versions of the document to see how the image markup appears in the formatted output. Image formats We currently support two formats for images. The format you should use will depend on the nature of your image. For images that are primarily vector based, such as network diagrams, timelines, and similar, use Encapsulated Postscript, and make sure that your images have the .eps extension. For bitmaps, such as screen captures, use the Portable Network Graphic format, and make sure that your images have the .png extension. These are the only formats in which images should be committed to the CVS repository. Use the right format for the right image. It is to be expected that your documentation will have a mix of EPS and PNG images. The Makefiles ensure that the correct format image is chosen depending on the output format that you use for your documentation. Do not commit the same image to the repository in two different formats. It is anticipated that the Documentation Project will switch to using the Scalable Vector Graphic (SVG) format for vector images. However, the current state of SVG capable editing tools makes this impractical. Markup The markup for an image is relatively simple. First, markup a mediaobject. The mediaobject can contain other, more specific objects. We are concerned with two, the imageobject and the textobject. You should include one imageobject, and two textobject elements. The imageobject will point to the name of the image file that will be used (without the extension). The textobject elements contain information that will be presented to the user as well as, or instead of, the image. There are two circumstances where this can happen. When the reader is viewing the documentation in HTML. In this case, each image will need to have associated alternate text to show the user, typically whilst the image is loading, or if they hover the mouse pointer over the image. When the reader is viewing the documentation in plain text. In this case, each image should have an ASCII art equivalent to show the user. An example will probably make things easier to understand. Suppose you have an image, called fig1, that you want to include in the document. This image is of a rectangle with an A inside it. The markup for this would be as follows. <mediaobject> <imageobject> <imagedata fileref="fig1"> </imageobject> <textobject> <literallayout class="monospaced">+---------------+ | A | +---------------+</literallayout> </textobject> <textobject> <phrase>A picture</phrase> </textobject> </mediaobject> Include an imagedata element inside the imageobject element. The fileref attribute should contain the filename of the image to include, without the extension. The stylesheets will work out which extension should be added to the filename automatically. The first textobject should contain a literallayout element, where the class attribute is set to monospaced. This is your opportunity to demonstrate your ASCII art skills. This content will be used if the document is converted to plain text. Notice how the first and last lines of the content of the literallayout element butt up next to the element's tags. This ensures no extraneous white space is included. The second textobject should contain a single phrase element. The contents of this will become the alt attribute for the image when this document is converted to HTML. <filename>Makefile</filename> entries Your images must be listed in the Makefile in the IMAGES variable. This variable should contain the name of all your source images. For example, if you have created three figures, fig1.eps, fig2.png, fig3.png, then your Makefile should have lines like this in it. … IMAGES= fig1.eps fig2.png fig3.png … or … IMAGES= fig1.eps IMAGES+= fig2.png IMAGES+= fig3.png … Again, the Makefile will work out the complete list of images it needs to build your source document, you only need to list the image files you provided. Images and chapters in subdirectories You must be careful when you separate your documentation in to smaller files (see ) in different directories. Suppose you have a book with three chapters, and the chapters are stored in their own directories, called chapter1/chapter.sgml, chapter2/chapter.sgml, and chapter3/chapter.sgml. If each chapter has images associated with it, I suggest you place those images in each chapter's subdirectory (chapter1/, chapter2/, and chapter3/). However, if you do this you must include the directory names in the IMAGES variable in the Makefile, and you must include the directory name in the imagedata element in your document. For example, if you have chapter1/fig1.png, then chapter1/chapter.sgml should contain <mediaobject> <imageobject> <imagedata fileref="chapter1/fig1"> </imageobject> … </mediaobject> The directory name must be included in the fileref attribute The Makefile must contain … IMAGES= chapter1/fig1.png … Then everything should just work. Links Links are also in-line elements. Linking to other parts of the same document - Linking within the same document requires you to to specify + Linking within the same document requires you to specify where you are linking from (i.e., the text the user will click, or otherwise indicate, as the source of the link) and where you are linking to (the link's destination). Each element within DocBook has an attribute called id. You can place text in this attribute to uniquely name the element it is attached to. This value will be used when you specify the link source. Normally, you will only be linking to chapters or sections, so you would add the id attribute to these elements. <literal>id on chapters and sections</literal> Introduction This is the introduction. It contains a subsection, which is identified as well. Sub-sect 1 This is the subsection. ]]> Obviously, you should use more descriptive values. The values must be unique within the document (i.e., not just the file, but the document the file might be included in as well). Notice how the id for the subsection is constructed by appending text to the id of the chapter. This helps to ensure that they are unique. If you want to allow the user to jump into a specific portion of the document (possibly in the middle of a paragraph or an example), use anchor. This element has no content, but takes an id attribute. <sgmltag>anchor</sgmltag> This paragraph has an embedded link target in it. It won't show up in the document.]]> When you want to provide the user with a link they can activate (probably by clicking) to go to a section of the document that has an id attribute, you can use either xref or link. Both of these elements have a linkend attribute. The value of this attribute should be the value that you have used in a id attribute (it does not matter if that value has not yet occurred in your document; this will work for forward links as well as backward links). If you use xref then you have no control over the text of the link. It will be generated for you. Using <sgmltag>xref</sgmltag> Assume that this fragment appears somewhere in a document that includes the id example; More information can be found in . More specific information can be found in .]]> The text of the link will be generated automatically, and will look like (emphasised text indicates the text that will be the link);
More information can be found in Chapter One. More specific information can be found in the section called Sub-sect 1.
Notice how the text from the link is derived from the section title or the chapter number. This means that you can not use xref to link to an id attribute on an anchor element. The anchor has no content, so the xref can not generate the text for the link. If you want to control the text of the link then use link. This element wraps content, and the content will be used for the link. Using <sgmltag>link</sgmltag> Assume that this fragment appears somewhere in a document that includes the id example. More information can be found in the first chapter. More specific information can be found in FreeBSD home page instead.]]> Appearance: Of course, you could stop reading this document and go to the FreeBSD home page instead. * LinuxDoc LinuxDoc is an adaptation of the QWERTZ DTD, first adopted by the Linux Documentation Project, and subsequently adopted by the FreeBSD Documentation Project. The LinuxDoc DTD contains primarily appearance related markup rather than content related markup (i.e., it describes what something looks like rather than what it is). Both the FreeBSD Documentation Project and the Linux Documentation Project are migrating from the LinuxDoc DTD to the DocBook DTD. The LinuxDoc DTD is available from the ports collection in the textproc/linuxdoc category. diff --git a/en_US.ISO8859-1/books/handbook/boot/chapter.sgml b/en_US.ISO8859-1/books/handbook/boot/chapter.sgml index d1c2c988c8..95676520eb 100644 --- a/en_US.ISO8859-1/books/handbook/boot/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/boot/chapter.sgml @@ -1,549 +1,549 @@ The FreeBSD Booting Process Synopsis FreeBSD uses a three-stage bootstrap by default, which basically entails three programs which call each other in order (two boot blocks, and the loader). Each of these three build on the previous program's understanding and provide increasing amounts of sophistication. The kernel is then started, which will then probe for devices and initialize them for use. Once the kernel boot process is finished, the kernel passes control to the user process &man.init.8;, which then makes sure the disks are in a usable state. &man.init.8; then starts the user-level resource configuration which then mounts filesystems, sets up network cards to act on the network, and generally starts all the processes that usually are run on a FreeBSD system at startup. The Boot Blocks: Bootstrap Stages 1 and 2 Bootstrapping is the process whereby a computer probes and initializes its devices, and works out what programs it is supposed to run. This involves the use of special Read Only Memory chips, which determine what further operations to do, and these usually pass control to other chips that do consistency and memory tests, configure devices, and provide a mechanism for programs to determine what configuration details were determined. In standard personal computers, this involves the BIOS (which oversees the bootstrap), and CMOS (which stores configuration). BIOS and CMOS understand disks, and also understand where on the disk to find a program that will know how to load up an operating system. This chapter will not deal with this first part of the bootstrap process. Instead it will focus on what happens after control is passed to the program on the disk. The boot blocks are responsible for finding (usually) the loader, and running it, and thus need to understand how to find that program on the filesystem, how to run the program, and also allow minor configuration of how they work. boot0 There is actually a preceding bootblock, named boot0, which lives on the Master Boot Record, the special part of the disk that the system bootstrap looks for and runs, and it simply shows a list of possible slices to boot from. boot0 is very simple, since the program in the MBR can only be 512 bytes in size. It displays something like this: boot0 screenshot F1 DOS F2 FreeBSD F3 Linux F4 ?? F5 Drive 1 Default: F2 boot1 boot1 is found on the boot sector of the boot slice, which is where boot0, or any other program on the MBR expects to find the program to run to continue the boot process. boot1 is very simple, since it too can only be 512 bytes in size, and knows just enough about the FreeBSD disklabel, which stores information about the slice, to find and execute boot2. boot2 boot2 is slightly more sophisticated, and understands the FreeBSD filesystem enough to find files on it, and can provide a simple interface to choose the kernel or loader to run. Since the loader is much more sophisticated, and provides a nice easy-to-use boot configuration, boot2 usually runs it, but previously it was tasked to run the kernel directly. boot2 screenshot >> FreeBSD/i386 BOOT Default: 0:wd(0,a)/kernel boot: Loader: Bootstrap Stage Three The loader is the final stage of the three-stage bootstrap, and is located on the filesystem, usually as /boot/loader. While /boot/boot0, /boot/boot1, and /boot/boot2 are files there, they are not the actual copies in the MBR, the boot sector, or the disklabel respectively. The loader is intended as a user-friendly method for configuration, using an easy-to-use built-in command set, backed up by a more powerful interpreter, with a more complex command set. Loader Program Flow During initialization, the loader will probe for a console and for disks, and figure out what disk it is booting from. It will set variables accordingly, and then the interpreter is started, and the easy-to-use commands are explained to it. loader will then read /boot/loader.rc, which by default reads in /boot/defaults/loader.conf which sets reasonable defaults for variables and reads /boot/loader.conf for local changes to those variables. loader.rc then acts on these variables, loading whichever modules and kernel are selected. Finally, by default, the loader issues a 10 second wait for key presses, and boots the kernel if it is not interrupted. If interrupted, the user is presented with a prompt which understands the easy-to-use command set, where the user may adjust variables, unload all modules, load modules, and then finally boot or reboot. A more technical discussion of the process is available in &man.loader.8; Loader Built-In Commands The easy-to-use command set comprises of: autoboot seconds Proceeds to boot the kernel if not interrupted within the time span given, in seconds. It displays a countdown, and the default timespan is 10 seconds. boot -options kernelname Immediately proceeds to boot the kernel, with the given options, if any, and with the kernel name given, if it is. boot-conf Goes through the same automatic configuration of modules based on variables as what happens at boot. This only makes sense if you use unload first, and change some variables, most commonly kernel. help topic Shows help messages read from /boot/loader.help. If the topic given is index, then the list of available topics is given. include filename … Processes the file with the given filename. The file is read in, and interpreted line by line. An error immediately stops the include command. load type filename Loads the kernel, kernel module, or file of the type given, with the filename given. Any arguments after filename are passed to the file. ls path Displays a listing of files in the given path, or the root directory, if the path is not specified. If is specified, file sizes will be shown too. lsdev Lists all of the devices from which it may be possible to load modules. If is specified, more details are printed. lsmod Displays loaded modules. If is specified, more details are shown. more filename Display the files specified, with a pause at each LINES displayed. reboot Immediately reboots the system. set variable set variable=value Set loader's environment variables. unload Removes all loaded modules. Loader Examples Here are some practical examples of loader usage. To simply boot your usual kernel, but in single-user mode: boot -s To unload your usual kernel and modules, and then load just your old (or another) kernel: unload load kernel.old You can use kernel.GENERIC to refer to the generic kernel that comes on the install disk, or kernel.old to refer to your previously installed kernel (when you've upgraded or configured your own kernel, for example). Use the following to load your usual modules with another kernel: unload set kernel="kernel.old" boot-conf To load a kernel configuration script (an automated script which does the things you'd normally do in the kernel boot-time configurator): load -t userconfig_script /boot/kernel.conf Kernel Interaction During Boot Once the kernel is loaded by either loader (as usual) or boot2 (bypassing the loader), it examines its boot flags, if any, and adjusts its behavior as necessary. Kernel Boot Flags Here are the more common boot flags: during kernel initialization, ask for the device - to mount as as the root file system. + to mount as the root file system. boot from CDROM. run UserConfig, the boot-time kernel configurator boot into single-user mode be more verbose during kernel startup There are other boot flags, read &man.boot.8; for more information on them. Init: Process Control Initialization Once the kernel has finished booting, it passes control to the user process init, which is located at /sbin/init, or the program path specified in the init_path variable in loader. Automatic Reboot Sequence The automatic reboot sequence makes sure that the filesystems available on the system are consistent. If they are not, and fsck can not fix the inconsistencies, init drops the system into single-user mode for the system administrator to take care of the problems directly. Single-User Mode This mode can be reached through the automatic reboot sequence, or by the user booting with the or setting the boot_single variable in loader. It can also be reached by calling shutdown without the reboot () or halt () options, from multi-user mode. If the system console console is set to insecure in /etc/ttys, then the system prompts for the root password before initiating single-user mode. An insecure console in /etc/ttys # name getty type status comments # # This entry needed for asking password when init goes to single-user mode # If you want to be asked for password, change "secure" to "insecure" here console none unknown off insecure An insecure console means that you consider your physical security to the console to be insecure, and want to make sure only someone who knows the root password may use single-user mode, and it does not mean that you want to run your console insecurely. Thus, if you want security, choose insecure, not secure. Multi-User Mode If init finds your filesystems to be in order, or once the user has finished in single-user mode, the system enters multi-user mode, in which it starts the resource configuration of the system. Resource Configuration (rc) The resource configuration system reads in configuration defaults from /etc/defaults/rc.conf, and system-specific details from /etc/rc.conf, and then proceeds to mount the system filesystems mentioned in /etc/fstab, start up networking services, starts up miscellaneous system daemons, and finally runs the startup scripts of locally installed packages. &man.rc.8; is a good reference to the resource configuration system, as is examining the scripts themselves. Shutdown Sequence Upon controlled shutdown, via shutdown, init will attempt to run the script /etc/rc.shutdown, and then proceed to send all processes the terminate signal, and subsequently the kill signal to any that don't terminate timely. diff --git a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml index 646638773c..469876183c 100644 --- a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml @@ -1,1073 +1,1073 @@ Disks Synopsis This chapter covers how to use disks, whether physical, memory, or networked, on FreeBSD. BIOS Drive Numbering Before you install and configure FreeBSD on your system, there is an important subject that you should be aware of if, especially if you have multiple hard drives. In a PC running DOS or any of the BIOS-dependent operating systems (WINxxx), 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's like switching the cables on the drives, but without having to open the case. 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's 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's 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's 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's 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. Disk Naming Physical drives come in two main flavors, IDE, or SCSI; but there are also drives backed by RAID controllers, flash memory, and so forth. Since these behave quite differently, they have their own drivers and devices. Physical Disk Naming Conventions Drive type Drive device name IDE hard drives ad in 4.0-RELEASE, wd before 4.0-RELEASE. IDE CDROM drives acd from 3.1-RELEASE, wcd before 4.0-RELEASE. SCSI hard drives da from 3.0-RELEASE, sd before 3.0-RELEASE. 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 Floppy drives fd SCSI tape drives sa from 3.0-RELEASE, st before 3.0-RELEASE. IDE tape drives ast from 4.0-RELEASE, wst before 4.0-RELEASE. Flash drives fla for DiskOnChip Flash device from 3.3-RELEASE. RAID drives myxd for Mylex, and amrd for AMI MegaRAID, idad for Compaq Smart RAID. from 4.0-RELEASE. id between 3.2-RELEASE and 4.0-RELEASE.
Slices and Partitions Physical disks usually contain slices, unless they are dangerously dedicated. Slice numbers follow the device name, prefixed with an s: da0s1. Slices, dangerously dedicated physical drives, and other drives contain partitions, which represented as letters from a to h. b is reserved for swap partitions, and c is an unused partition the size of the entire slice or drive. This is explained in . Mounting and Unmounting Filesystems The filesystem is best visualized as a tree, rooted, as it were, at /. /dev, /usr, and the other directories in the root directory are branches, which may have their own branches, such as /usr/local, and so on. There are various reasons to house some of these directories on separate filesystems. /var contains log, spool, and various types of temporary files, and as such, may get filled up. Filling up the root filesystem isn't a good idea, so splitting /var from / is often a good idea. Another common reason to contain certain directory trees on other filesystems is if they are to be housed on separate physical disks, or are separate virtual disks, such as Network File System mounts, or CDROM drives. The fstab File During the boot process, filesystems listed in /etc/fstab are automatically mounted (unless they are listed with ). The /etc/fstab file contains a list of lines of the following format: device /mount-point fstype options dumpfreq passno device is a device name (which should exist), as explained in the Disk naming conventions above. mount-point is a directory (which should exist), on which to mount the filesystem. fstype is the filesystem type to pass to &man.mount.8;. The default FreeBSD filesystem is ufs. options is either for read-write filesystems, or for read-only filesystems, followed by any other options that may be needed. A common option is for filesystems not normally mounted during the boot sequence. Other options in the &man.mount.8; manual page. dumpfreq is the number of days the filesystem should be dumped, and passno is the pass number during which the filesystem is mounted during the boot sequence. The mount Command The &man.mount.8; command is what is ultimately used to mount filesystems. In its most basic form, you use: &prompt.root; mount device mountpoint There are plenty of options, as mentioned in the &man.mount.8; manual page, but the most common are: mount options Mount all filesystems in /etc/fstab, as modified by , if given. Do everything but actually mount the filesystem. Force the mounting the filesystem. Mount the filesystem read-only. fstype Mount the given filesystem as the given filesystem type, or mount only filesystems of the given type, if given the option. ufs is the default filesystem type. Update mount options on the filesystem. Be verbose. Mount the filesystem read-write. The takes a comma-separated list of the options, including the following: nodev Do not interpret special devices on the filesystem. Useful security option. noexec Do not allow execution of binaries on this filesystem. Useful security option. nosuid Do not interpret setuid or setgid flags on the filesystem. Useful security option. The umount Command The umount command takes, as a parameter, one of a mountpoint, a device name, or the or option. All forms take to force unmounting, and for verbosity. and are used to unmount all mounted filesystems, possibly modified by the filesystem types listed after . , however, doesn't attempt to unmount the root filesystem. Adding Disks Originally contributed by &a.obrien; 26 April 1998 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 the wide variations of procedures to do this, the details are beyond the scope of this document. Login as user root. After you've 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, it will be wd1 in pre-4.0 systems, or ad1 in most 4.X systems). 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 with in 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. Using sysinstall 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. With in the FreeBSD Configuration Menu, scroll down and select the Partition item. Next you should be presented with a list of hard drives installed in your system. If you do not see da1 listed, you need to recheck your physical installation and dmesg output in the file /var/run/dmesg.boot. Select da1 to enter the FDISK Partition Editor. Choose 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 using q. Next you will be asked about the Master Boot Record. Since you are adding a disk to an already running system, choose None. Next 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. With in the Label editor, create a single file system using C. When prompted if this will be a FS (file system) or swap, choose FS and give 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 isn't important. You are now ready to write the new label to the disk and create a file system on it. Do this by hitting W. Ignore any errors from Sysinstall that it could not mount the new partition. Exit the Label Editor and Sysinstall completely. 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/rda1 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 # Now edit the disklabel you 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 -t ufs /dev/da1s1e /1 # Mount the partition(s) &prompt.root; vi /etc/fstab # When satisfied, 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 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 OS/2 however, will appropriate any partition it finds which it doesn't understand. &prompt.root; dd if=/dev/zero of=/dev/rda1 bs=1k count=1 &prompt.root; disklabel -Brw da1 auto &prompt.root; disklabel -e da1 # create the `e' partition &prompt.root; newfs -d0 /dev/rda1e &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/rda1 count=2 &prompt.root; disklabel /dev/rda1 | disklabel -BrR da1 /dev/stdin &prompt.root; newfs /dev/rda1e &prompt.root; mkdir -p /1 &prompt.root; vi /etc/fstab # add an entry for /dev/da1e &prompt.root; mount /1 Virtual Disks: Network, Memory, and File-Based Filesystems 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. These include network filesystems such as the Network Filesystem and Coda, memory-based filesystems such as md and file-backed filesystems created by vnconfig. vnconfig: file-backed filesystem &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 filesystem. One possible use is the mounting of floppy or CD images kept in files. To mount an existing filesystem image: Using vnconfig to mount an existing filesystem image &prompt.root; vnconfig vn0 diskimage &prompt.root; mount /dev/vn0c /mnt To create a new filesystem image with vnconfig: Creating a New File-Backed Disk with vnconfig &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/rvn0c: 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 md: Memory Filesystem md is a simple, efficient means to do memory filesystems. Simply take a filesystem you've prepared with, for example, &man.vnconfig.8;, and: md memory disk &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 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 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 the Configuring the FreeBSD Kernel section 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 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 quotacheck program. The quotacheck 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 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 userquota option to the options field in the /etc/fstab entry for the file system you want - to to enable quotas on. For example: + to enable quotas on. For example: /dev/da1s2g /home ufs rw,userquota 1 2 Similarly, to enable group quotas, use the groupquota option instead of the userquota keyword. 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 for more information. Even though that man 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 quotacheck, quotaon, or quotaoff commands manually. However, you may want to read their man pages just to be familiar with their operation. Setting Quota 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 edquota 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. 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 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 edquota command. When the edquota 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 users 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 edquota 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 See man edquota for more detailed information. Checking Quota Limits and Disk Usage You can use either the quota or the repquota commands to check quota limits and disk usage. The quota command can be used to check individual user and group quotas and disk usage. Only the super-user may examine quotas and usage for other users, or for groups that they are not a member of. The repquota 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 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 quota 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 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` Creating CDs Contributed by Mike Meyer mwm@mired.org, April 2001. Introduction CDs have a number of features that differentiate them from conventional disks. Initially, they weren't 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. 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. The mkisofs program is used to produce a data file containing an ISO 9660 file system. It has options that support various extensions, and is described below. You can install it with the /usr/ports/sysutils/mkisofs port. 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 the cdrecord from the /usr/ports/sysutils/cdrecord port. mkisofs mkisofs 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 imagefile.iso /path/to/tree This command will create an imagefile 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. Read &man.mkisofs.8; for details of this process, and options that can be used to control it. 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 Macs. Read &man.mkisofs.8; for more information on the last two. 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. 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. So, given that /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 boot/cdboot /tmp/bootable.iso /tmp/myboot Having done that, if you have vn configured in your kernel, you can mount the file system with: &prompt.root; vnconfig vn0c /tmp/bootable.iso &prompt.root; mount cd9660 /dev/vn0c /mnt At which point you can verify that /mnt and /tmp/myboot are identical. There are many other options you can use with mkisofs to fine-tune its behavior. See &man.mkisofs.8; for details. burncd 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 cddevice data imagefile.iso fixate Will burn a copy of imagefile.iso on cddevice. The default device is /dev/acd0. 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 /usr/ports/sysutils/cdrecord 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 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: &prompt.root; cdrecord 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 =1,5,0. 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. diff --git a/en_US.ISO8859-1/books/handbook/hw/chapter.sgml b/en_US.ISO8859-1/books/handbook/hw/chapter.sgml index 79502f53d7..2898faf3d7 100644 --- a/en_US.ISO8859-1/books/handbook/hw/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/hw/chapter.sgml @@ -1,5854 +1,5854 @@ PC Hardware compatibility Issues of hardware compatibility are among the most troublesome in the computer industry today and FreeBSD is by no means immune to trouble. In this respect, FreeBSD's advantage of being able to run on inexpensive commodity PC hardware is also its liability when it comes to support for the amazing variety of components on the market. While it would be impossible to provide an exhaustive listing of hardware that FreeBSD supports, this section serves as a catalog of the device drivers included with FreeBSD and the hardware each drivers supports. Where possible and appropriate, notes about specific products are included. You may also want to refer to the kernel configuration file section in this handbook for a list of supported devices. As FreeBSD is a volunteer project without a funded testing department, we depend on you, the user, for much of the information contained in this catalog. If you have direct experience of hardware that does or does not work with FreeBSD, please let us know by sending e-mail to the &a.doc;. Questions about supported hardware should be directed to the &a.questions; (see Mailing Lists for more information). When submitting information or asking a question, please remember to specify exactly what version of FreeBSD you are using and include as many details of your hardware as possible. Resources on the Internet The following links have proven useful in selecting hardware. Though some of what you see won't necessarily be specific (or even applicable) to FreeBSD, most of the hardware information out there is OS independent. Please check with the FreeBSD hardware guide to make sure that your chosen configuration is supported before making any purchases. The Pentium Systems Hardware Performance Guide Sample Configurations The following list of sample hardware configurations by no means constitutes an endorsement of a given hardware vendor or product by The FreeBSD Project. This information is provided only as a public service and merely catalogs some of the experiences that various individuals have had with different hardware combinations. Your mileage may vary. Slippery when wet. Beware of dog. Jordan's Picks I have had fairly good luck building workstation and server configurations with the following components. I can't guarantee that you will too, nor that any of the companies here will remain best buys forever. I will try, when I can, to keep this list up-to-date but cannot obviously guarantee that it will be at any given time. Motherboards For Pentium Pro (P6) systems, I'm quite fond of the Tyan S1668 dual-processor motherboard as well as the Intel PR440FX motherboard with on-board SCSI WIDE and 100/10MB Intel EtherExpress NIC. You can build a dandy little single or dual processor system (which is supported in FreeBSD 3.0) for very little cost now that the Pentium Pro 180/256K chips have fallen so greatly in price, but no telling how much longer this will last. For the Pentium II, I'm rather partial to the ASUS P2l97-S motherboard with the on-board Adaptec SCSI WIDE controller. For Pentium machines, the ASUS P55T2P4 motherboard appears to be a good choice for mid-to-high range Pentium server and workstation systems. Those wishing to build more fault-tolerant systems should also be sure to use Parity memory or, for truly 24/7 applications, ECC memory. ECC memory does involve a slight performance trade-off (which may or may not be noticeable depending on your application) but buys you significantly increased fault-tolerance to memory errors. Disk Controllers This one is a bit trickier, and while I used to recommend the Buslogic controllers unilaterally for everything from ISA to PCI, now I tend to lean towards the Adaptec 1542CF for ISA, Buslogic Bt747c for EISA and Adaptec 2940UW for PCI. The NCR/Symbios cards for PCI have also worked well for me, though you need to make sure that your motherboard supports the BIOS-less model if you're using one of those (if your card has nothing which looks even vaguely like a ROM chip on it, you've probably got one which expects its BIOS to be on your motherboard). If you should find that you need more than one SCSI controller in a PCI machine, you may wish to consider conserving your scarce PCI bus resources by buying the Adaptec 3940 card, which puts two SCSI controllers (and internal busses) in a single slot. There are two types of 3940 on the market—the older model with AIC 7880 chips on it, and the newer one with AIC 7895 chips. The newer model requires CAM support which is not yet part of FreeBSD—you have to add it, or install from one of the CAM binary snapshot release. Disk drives In this particular game of Russian roulette, I'll make few specific recommendations except to say SCSI over IDE whenever you can afford it. Even in small desktop configurations, SCSI often makes more sense since it allows you to easily migrate drives from server to desktop as falling drive prices make it economical to do so. If you have more than one machine to administer then think of it not simply as storage, think of it as a food chain! For a serious server configuration, there's not even any argument—use SCSI equipment and good cables. CDROM drives My SCSI preferences extend to SCSI CDROM drives as well, and while the Toshiba drives have always been favorites of mine (in whatever speed is hot that week), I'm still fond of my good old Plextor PX-12CS drive. It's only a 12 speed, but it's offered excellent performance and reliability. Generally speaking, most SCSI CDROM drives I've seen have been of pretty solid construction and you probably won't go wrong with an HP or NEC SCSI CDROM drive either. SCSI CDROM prices also appear to have dropped considerably in the last few months and are now quite competitive with IDE CDROMs while remaining a technically superior solution. I now see no reason whatsoever to settle for an IDE CDROM drive if given a choice between the two. CD Recordable (WORM) drives At the time of this writing, FreeBSD supports 3 types of CDR drives (though I believe they all ultimately come from Phillips anyway): The Phillips CDD 522 (Acts like a Plasmon), the PLASMON RF4100 and the HP 6020i. I myself use the HP 6020i for burning CDROMs (in 2.2 and later releases—it does not work with earlier releases of the SCSI code) and it works very well. See /usr/share/examples/worm on your 2.2 system for example scripts used to created ISO9660 filesystem images (with RockRidge extensions) and burn them onto an HP6020i CDR. Tape drives I've had pretty good luck with both 8mm drives from Exabyte and 4mm (DAT) drives from HP. For backup purposes, I'd have to give the higher recommendation to the Exabyte due to the more robust nature (and higher storage capacity) of 8mm tape. Video Cards If you can also afford to buy a commercial X server for US$99 from Xi Graphics, Inc. (formerly X Inside, Inc) then I can heartily recommend the Matrox Millenium II card. Note that support for this card is also excellent with the XFree86 server, which is now at version 3.3.2. You also certainly can't go wrong with one of Number 9's cards — their S3 Vision 868 and 968 based cards (the 9FX series) also being quite fast and very well supported by XFree86's S3 server. You can also pick up their Revolution 3D cards very cheaply these days, especially if you require a lot of video memory. Monitors I have had very good luck with the Sony Multiscan 17seII monitors, as have I with the Viewsonic offering in the same (Trinitron) tube. For larger than 17", all I can recommend at the time of this writing is to not spend any less than U.S. $2,000 for a 21" monitor or $1,700 for a 20" monitor if that's what you really need. There are good monitors available in the >=20" range and there are also cheap monitors in the >=20" range. Unfortunately, very few are both cheap and good! Networking I can recommend the Intel EtherExpress Pro/100B card first and foremost, followed by the SMC Ultra 16 controller for any ISA application and the SMC EtherPower or Compex ENET32 cards for slightly cheaper PCI based networking. In general, any PCI NIC based around DEC's DC21041 Ethernet controller chip, such as the Znyx ZX342 or DEC DE435/450, will generally work quite well and can frequently be found in 2-port and 4-port version (useful for firewalls and routers), though the Pro/100MB card has the edge when it comes to providing the best performance with lower overhead. If what you're looking for is the cheapest possible solution then almost any NE2000 clone will do a fine job for very little cost. Serial If you're looking for high-speed serial networking solutions, then Digi International makes the SYNC/570 series, with drivers now in FreeBSD-CURRENT. Emerging Technologies also manufactures a board with T1/E1 capabilities, using software they provide. I have no direct experience using either product, however. multiport card options are somewhat more numerous, though it has to be said that FreeBSD's support for Cyclades's products is probably the tightest, primarily as a result of that company's commitment to making sure that we are adequately supplied with evaluation boards and technical specs. I've heard that the Cyclom-16Ye offers the best price/performance, though I've not checked the prices lately. Other multiport cards I've heard good things about are the BOCA and AST cards, and Stallion Technologies apparently offers an unofficial driver for their cards at this location. Audio I currently use a Creative Labs AWE32 though just about anything from Creative Labs will generally work these days. This is not to say that other types of sound cards don't also work, simply that I have little experience with them (I was a former GUS fan, but Gravis's sound card situation has been dire for some time). Video For video capture, there are two good choices — any card based on the Brooktree BT848 chip, such as the Hauppauge or WinTV boards, will work very nicely with FreeBSD. Another board which works for me is the Matrox Meteor card. FreeBSD also supports the older video spigot card from Creative Labs, but those are getting somewhat difficult to find. Note that the Meteor frame grabber card will not work with motherboards based on the 440FX chipset! See the motherboard reference section for details. In such cases, it's better to go with a BT848 based board. Core/Processing Motherboards, busses, and chipsets * ISA * EISA * VLB PCI Contributed by &a.obrien; from postings by &a.rgrimes;. 25 April 1995. Continuing updates by &a.jkh;. Last update on 26 August 1996. Of the Intel PCI chip sets, the following list describes various types of known-brokenness and the degree of breakage, listed from worst to best. Mercury: Cache coherency problems, especially if there are ISA bus masters behind the ISA to PCI bridge chip. Hardware flaw, only known work around is to turn the cache off. Saturn-I (ie, 82424ZX at rev 0, 1 or 2): Write back cache coherency problems. Hardware flaw, only known work around is to set the external cache to write-through mode. Upgrade to Saturn-II. Saturn-II (ie, 82424ZX at rev 3 or 4): Works fine, but many MB manufactures leave out the external dirty bit SRAM needed for write back operation. You can work around this either by running it in write through mode, or get the dirty bit SRAM installed (I have these for the ASUS PCI/I-486SP3G rev 1.6 and later boards). Neptune: Can not run more than 2 bus master devices. Admitted Intel design flaw. Workarounds include do not run more than 2 bus masters, special hardware design to replace the PCI bus arbiter (appears on Intel Altair board and several other Intel server group MB's). And of course Intel's official answer, move to the Triton chip set, we fixed it there. Triton (ie, 430FX): No known cache coherency or bus master problems, chip set does not implement parity checking. Workaround for parity issue. Use Triton-II based motherboards if you have the choice. Triton-II (ie, 430HX): All reports on motherboards using this chipset have been favorable so far. No known problems. Orion: Early versions of this chipset suffered from a PCI write-posting bug which can cause noticeable performance degradation in applications where large amounts of PCI bus traffic is involved. B0 stepping or later revisions of the chipset fixed this problem. 440FX: This Pentium Pro support chipset seems to work well, and does not suffer from any of the early Orion chipset problems. It also supports a wider variety of memory, including ECC and parity. The only known problem with it is that the Matrox Meteor frame grabber card doesn't like it. CPUs/FPUs Contributed by &a.asami;. 26 December 1997. P6 class (Pentium Pro/Pentium II) Both the Pentium Pro and Pentium II work fine with FreeBSD. In fact, our main FTP site ftp.FreeBSD.org (also known as "ftp.cdrom.com", world's largest ftp site) runs FreeBSD on a Pentium Pro. Configurations details are available for interested parties. Pentium class The Intel Pentium (P54C), Pentium MMX (P55C), AMD K6 and Cyrix/IBM 6x86MX processors are all reported to work with FreeBSD. I will not go into details of which processor is faster than what, there are millions of web sites on the Internet that tells you one way or another. :) Various CPUs have different voltage/cooling requirements. Make sure your motherboard can supply the exact voltage needed by the CPU. For instance, many recent MMX chips require split voltage (e.g., 2.9V core, 3.3V I/O). Also, some AMD and Cyrix/IBM chips run hotter than Intel chips. In that case, make sure you have good heatsink/fans (you can get the list of certified parts from their web pages). Clock speeds Contributed by &a.rgrimes;. 1 October 1996. Updated by &a.asami;. 27 December 1997. Pentium class machines use different clock speeds for the various parts of the system. These being the speed of the CPU, external memory bus, and the PCI bus. It is not always true that a faster processor will make a system faster than a slower one, due to the various clock speeds used. Below is a table showing the differences: Rated CPU MHz External Clock and Memory Bus MHz External to Internal Clock Multiplier PCI Bus Clock MHz 60 60 1.0 30 66 66 1.0 33 75 50 1.5 25 90 60 1.5 30 100 50 2 25 100 66 1.5 33 120 60 2 30 133 66 2 33 150 60 2.5 30 (Intel, AMD) 150 75 2 37.5 (Cyrix/IBM 6x86MX) 166 66 2.5 33 180 60 3 30 200 66 3 33 233 66 3.5 33 66MHz may actually be 66.667MHz, but don't assume so. The Pentium 100 can be run at either 50MHz external clock with a multiplier of 2 or at 66MHz and a multiplier of 1.5. As can be seen the best parts to be using are the 100, 133, 166, 200 and 233, with the exception that at a multiplier of 3 or more the CPU starves for memory. The AMD K6 Bug In 1997, there have been reports of the AMD K6 seg faulting during heavy compilation. That problem has been fixed in 3Q '97. According to reports, K6 chips with date mark 9733 or larger (i.e., manufactured in the 33rd week of '97 or later) do not have this bug. * 486 class * 386 class 286 class Sorry, FreeBSD does not run on 80286 machines. It is nearly impossible to run today's large full-featured unices on such hardware. * Memory The minimum amount of memory you must have to install FreeBSD is 5 MB. Once your system is up and running you can build a custom kernel that will use less memory. If you use the boot4.flp you can get away with having only 4 MB. * BIOS Input/Output Devices * Video cards * Sound cards Serial ports and multiport cards The UART: What it is and how it works Copyright © 1996 &a.uhclem;, All Rights Reserved. 13 January 1996. The Universal Asynchronous Receiver/Transmitter (UART) controller is the key component of the serial communications subsystem of a computer. The UART takes bytes of data and transmits the individual bits in a sequential fashion. At the destination, a second UART re-assembles the bits into complete bytes. Serial transmission is commonly used with modems and for non-networked communication between computers, terminals and other devices. There are two primary forms of serial transmission: Synchronous and Asynchronous. Depending on the modes that are supported by the hardware, the name of the communication sub-system will usually include a A if it supports Asynchronous communications, and a S if it supports Synchronous communications. Both forms are described below. Some common acronyms are:
UART Universal Asynchronous Receiver/Transmitter
USART Universal Synchronous-Asynchronous Receiver/Transmitter
Synchronous Serial Transmission Synchronous serial transmission requires that the sender and receiver share a clock with one another, or that the sender provide a strobe or other timing signal so that the receiver knows when to read the next bit of the data. In most forms of serial Synchronous communication, if there is no data available at a given instant to transmit, a fill character must be sent instead so that data is always being transmitted. Synchronous communication is usually more efficient because only data bits are transmitted between sender and receiver, and - synchronous communication can be more more costly if extra wiring + synchronous communication can be more costly if extra wiring and circuits are required to share a clock signal between the sender and receiver. A form of Synchronous transmission is used with printers and fixed disk devices in that the data is sent on one set of wires while a clock or strobe is sent on a different wire. Printers and fixed disk devices are not normally serial devices because most fixed disk interface standards send an entire word of data for each clock or strobe signal by using a separate wire for each bit of the word. In the PC industry, these are known as Parallel devices. The standard serial communications hardware in the PC does not support Synchronous operations. This mode is described here for comparison purposes only. Asynchronous Serial Transmission Asynchronous transmission allows data to be transmitted without the sender having to send a clock signal to the receiver. Instead, the sender and receiver must agree on timing parameters in advance and special bits are added to each word which are used to synchronize the sending and receiving units. When a word is given to the UART for Asynchronous transmissions, a bit called the "Start Bit" is added to the beginning of each word that is to be transmitted. The Start Bit is used to alert the receiver that a word of data is about to be sent, and to force the clock in the receiver into synchronization with the clock in the transmitter. These two clocks must be accurate enough to not have the frequency drift by more than 10% during the transmission of the remaining bits in the word. (This requirement was set in the days of mechanical teleprinters and is easily met by modern electronic equipment.) After the Start Bit, the individual bits of the word of data are sent, with the Least Significant Bit (LSB) being sent first. Each bit in the transmission is transmitted for exactly the same amount of time as all of the other bits, and the receiver looks at the wire at approximately halfway through the period assigned to each bit to determine if the bit is a 1 or a 0. For example, if it takes two seconds to send each bit, the receiver will examine the signal to determine if it is a 1 or a 0 after one second has passed, then it will wait two seconds and then examine the value of the next bit, and so on. The sender does not know when the receiver has looked at the value of the bit. The sender only knows when the clock says to begin transmitting the next bit of the word. When the entire data word has been sent, the transmitter may add a Parity Bit that the transmitter generates. The Parity Bit may be used by the receiver to perform simple error checking. Then at least one Stop Bit is sent by the transmitter. When the receiver has received all of the bits in the data word, it may check for the Parity Bits (both sender and receiver must agree on whether a Parity Bit is to be used), and then the receiver looks for a Stop Bit. If the Stop Bit does not appear when it is supposed to, the UART considers the entire word to be garbled and will report a Framing Error to the host processor when the data word is read. The usual cause of a Framing Error is that the sender and receiver clocks were not running at the same speed, or that the signal was interrupted. Regardless of whether the data was received correctly or not, the UART automatically discards the Start, Parity and Stop bits. If the sender and receiver are configured identically, these bits are not passed to the host. If another word is ready for transmission, the Start Bit for the new word can be sent as soon as the Stop Bit for the previous word has been sent. Because asynchronous data is self synchronizing, if there is no data to transmit, the transmission line can be idle. Other UART Functions In addition to the basic job of converting data from parallel to serial for transmission and from serial to parallel on reception, a UART will usually provide additional circuits for signals that can be used to indicate the state of the transmission media, and to regulate the flow of data in the event that the remote device is not prepared to accept more data. For example, when the device connected to the UART is a modem, the modem may report the presence of a carrier on the phone line while the computer may be able to instruct the modem to reset itself or to - not take calls by asserting or disasserting one more more of these + not take calls by asserting or disasserting one more of these extra signals. The function of each of these additional signals is defined in the EIA RS232-C standard. The RS232-C and V.24 Standards In most computer systems, the UART is connected to circuitry that generates signals that comply with the EIA RS232-C specification. There is also a CCITT standard named V.24 that mirrors the specifications included in RS232-C. RS232-C Bit Assignments (Marks and Spaces) In RS232-C, a value of 1 is called a Mark and a value of 0 is called a Space. When a communication line is idle, the line is said to be Marking, or transmitting continuous 1 values. The Start bit always has a value of 0 (a Space). The Stop Bit always has a value of 1 (a Mark). This means that there will always be a Mark (1) to Space (0) transition on the line at the start of every word, even when multiple word are transmitted back to back. This guarantees that sender and receiver can resynchronize their clocks regardless of the content of the data bits that are being transmitted. The idle time between Stop and Start bits does not have to be an exact multiple (including zero) of the bit rate of the communication link, but most UARTs are designed this way for simplicity. In RS232-C, the "Marking" signal (a 1) is represented by a voltage between -2 VDC and -12 VDC, and a "Spacing" signal (a 0) is represented by a voltage between 0 and +12 VDC. The transmitter is supposed to send +12 VDC or -12 VDC, and the receiver is supposed to allow for some voltage loss in long cables. Some transmitters in low power devices (like portable computers) sometimes use only +5 VDC and -5 VDC, but these values are still acceptable to a RS232-C receiver, provided that the cable lengths are short. RS232-C Break Signal RS232-C also specifies a signal called a Break, which is caused by sending continuous Spacing values (no Start or Stop bits). When there is no electricity present on the data circuit, the line is considered to be sending Break. The Break signal must be of a duration longer than the time it takes to send a complete byte plus Start, Stop and Parity bits. Most UARTs can distinguish between a Framing Error and a Break, but if the UART cannot do this, the Framing Error detection can be used to identify Breaks. In the days of teleprinters, when numerous printers around the country were wired in series (such as news services), any unit could cause a Break by temporarily opening the entire circuit so that no current flowed. This was used to allow a location with urgent news to interrupt some other location that was currently sending information. In modern systems there are two types of Break signals. If the Break is longer than 1.6 seconds, it is considered a "Modem Break", and some modems can be programmed to terminate the conversation and go on-hook or enter the modems' command mode when the modem detects this signal. If the Break is smaller than 1.6 seconds, it signifies a Data Break and it is up to the remote computer to respond to this signal. Sometimes this form of Break is used as an Attention or Interrupt signal and sometimes is accepted as a substitute for the ASCII CONTROL-C character. Marks and Spaces are also equivalent to Holes and No Holes in paper tape systems. Breaks cannot be generated from paper tape or from any other byte value, since bytes are always sent with Start and Stop bit. The UART is usually capable of generating the continuous Spacing signal in response to a special command from the host processor. RS232-C DTE and DCE Devices The RS232-C specification defines two types of equipment: the Data Terminal Equipment (DTE) and the Data Carrier Equipment (DCE). Usually, the DTE device is the terminal (or computer), and the DCE is a modem. Across the phone line at the other end of a conversation, the receiving modem is also a DCE device and the computer that is connected to that modem is a DTE device. The DCE device receives signals on the pins that the DTE device transmits on, and vice versa. When two devices that are both DTE or both DCE must be connected together without a modem or a similar media translater between them, a NULL modem must be used. The NULL modem electrically re-arranges the cabling so that the transmitter output is connected to the receiver input on the other device, and vice versa. Similar translations are performed on all of the control signals so that each device will see what it thinks are DCE (or DTE) signals from the other device. The number of signals generated by the DTE and DCE devices are not symmetrical. The DTE device generates fewer signals for the DCE device than the DTE device receives from the DCE. RS232-C Pin Assignments The EIA RS232-C specification (and the ITU equivalent, V.24) calls for a twenty-five pin connector (usually a DB25) and defines the purpose of most of the pins in that connector. In the IBM Personal Computer and similar systems, a subset of RS232-C signals are provided via nine pin connectors (DB9). The signals that are not included on the PC connector deal mainly with synchronous operation, and this transmission mode is not supported by the UART that IBM selected for use in the IBM PC. Depending on the computer manufacturer, a DB25, a DB9, or both types of connector may be used for RS232-C communications. (The IBM PC also uses a DB25 connector for the parallel printer interface which causes some confusion.) Below is a table of the RS232-C signal assignments in the DB25 and DB9 connectors. DB25 RS232-C Pin DB9 IBM PC Pin EIA Circuit Symbol CCITT Circuit Symbol Common Name Signal Source Description 1 - AA 101 PG/FG - Frame/Protective Ground 2 3 BA 103 TD DTE Transmit Data 3 2 BB 104 RD DCE Receive Data 4 7 CA 105 RTS DTE Request to Send 5 8 CB 106 CTS DCE Clear to Send 6 6 CC 107 DSR DCE Data Set Ready 7 5 AV 102 SG/GND - Signal Ground 8 1 CF 109 DCD/CD DCE Data Carrier Detect 9 - - - - - Reserved for Test 10 - - - - - Reserved for Test 11 - - - - - Reserved for Test 12 - CI 122 SRLSD DCE Sec. Recv. Line Signal Detector 13 - SCB 121 SCTS DCE Secondary Clear to Send 14 - SBA 118 STD DTE Secondary Transmit Data 15 - DB 114 TSET DCE Trans. Sig. Element Timing 16 - SBB 119 SRD DCE Secondary Received Data 17 - DD 115 RSET DCE Receiver Signal Element Timing 18 - - 141 LOOP DTE Local Loopback 19 - SCA 120 SRS DTE Secondary Request to Send 20 4 CD 108.2 DTR DTE Data Terminal Ready 21 - - - RDL DTE Remote Digital Loopback 22 9 CE 125 RI DCE Ring Indicator 23 - CH 111 DSRS DTE Data Signal Rate Selector 24 - DA 113 TSET DTE Trans. Sig. Element Timing 25 - - 142 - DCE Test Mode Bits, Baud and Symbols Baud is a measurement of transmission speed in asynchronous communication. Because of advances in modem communication technology, this term is frequently misused when describing the data rates in newer devices. Traditionally, a Baud Rate represents the number of bits that are actually being sent over the media, not the amount of data that is actually moved from one DTE device to the other. The Baud count includes the overhead bits Start, Stop and Parity that are generated by the sending UART and removed by the receiving UART. This means that seven-bit words of data actually take 10 bits to be completely transmitted. Therefore, a modem capable of moving 300 bits per second from one place to another can normally only move 30 7-bit words if Parity is used and one Start and Stop bit are present. If 8-bit data words are used and Parity bits are also used, the data rate falls to 27.27 words per second, because it now takes 11 bits to send the eight-bit words, and the modem still only sends 300 bits per second. The formula for converting bytes per second into a baud rate and vice versa was simple until error-correcting modems came along. These modems receive the serial stream of bits from the UART in the host computer (even when internal modems are used the data is still frequently serialized) and converts the bits back into bytes. These bytes are then combined into packets and sent over the phone line using a Synchronous transmission method. This means that the Stop, Start, and Parity bits added by the UART in the DTE (the computer) were removed by the modem before transmission by the sending modem. When these bytes are received by the remote modem, the remote modem adds Start, Stop and Parity bits to the words, converts them to a serial format and then sends them to the receiving UART in the remote computer, who then strips the Start, Stop and Parity bits. The reason all these extra conversions are done is so that the two modems can perform error correction, which means that the receiving modem is able to ask the sending modem to resend a block of data that was not received with the correct checksum. This checking is handled by the modems, and the DTE devices are usually unaware that the process is occurring. By striping the Start, Stop and Parity bits, the additional bits of data that the two modems must share between themselves to perform error-correction are mostly concealed from the effective transmission rate seen by the sending and receiving DTE equipment. For example, if a modem sends ten 7-bit words to another modem without including the Start, Stop and Parity bits, the sending modem will be able to add 30 bits of its own information that the receiving modem can use to do error-correction without impacting the transmission speed of the real data. The use of the term Baud is further confused by modems that perform compression. A single 8-bit word passed over the telephone line might represent a dozen words that were transmitted to the sending modem. The receiving modem will expand the data back to its original content and pass that data to the receiving DTE. Modern modems also include buffers that allow the rate that bits move across the phone line (DCE to DCE) to be a different speed than the speed that the bits move between the DTE and DCE on both ends of the conversation. Normally the speed between the DTE and DCE is higher than the DCE to DCE speed because of the use of compression by the modems. Because the number of bits needed to describe a byte varied during the trip between the two machines plus the differing bits-per-seconds speeds that are used present on the DTE-DCE and DCE-DCE links, the usage of the term Baud to describe the overall communication speed causes problems and can misrepresent the true transmission speed. So Bits Per Second (bps) is the correct term to use to describe the transmission rate seen at the DCE to DCE interface and Baud or Bits Per Second are acceptable terms to use when a connection is made between two systems with a wired connection, or if a modem is in use that is not performing error-correction or compression. Modern high speed modems (2400, 9600, 14,400, and 19,200bps) in reality still operate at or below 2400 baud, or more accurately, 2400 Symbols per second. High speed modem are able to encode more bits of data into each Symbol using a technique called Constellation Stuffing, which is why the effective bits per second rate of the modem is higher, but the modem continues to operate within the limited audio bandwidth that the telephone system provides. Modems operating at 28,800 and higher speeds have variable Symbol rates, but the technique is the same. The IBM Personal Computer UART Starting with the original IBM Personal Computer, IBM selected the National Semiconductor INS8250 UART for use in the IBM PC Parallel/Serial Adapter. Subsequent generations of compatible computers from IBM and other vendors continued to use the INS8250 or improved versions of the National Semiconductor UART family. National Semiconductor UART Family Tree There have been several versions and subsequent generations of the INS8250 UART. Each major version is described below. INS8250 -> INS8250B \ \ \-> INS8250A -> INS82C50A \ \ \-> NS16450 -> NS16C450 \ \ \-> NS16550 -> NS16550A -> PC16550D INS8250 This part was used in the original IBM PC and IBM PC/XT. The original name for this part was the INS8250 ACE (Asynchronous Communications Element) and it is made from NMOS technology. The 8250 uses eight I/O ports and has a one-byte send and a one-byte receive buffer. This original UART has several race conditions and other flaws. The original IBM BIOS includes code to work around these flaws, but this made the BIOS dependent on the flaws being present, so subsequent parts like the 8250A, 16450 or 16550 could not be used in the original IBM PC or IBM PC/XT. INS8250-B This is the slower speed of the INS8250 made from NMOS technology. It contains the same problems as the original INS8250. INS8250A An improved version of the INS8250 using XMOS technology with various functional flaws corrected. The INS8250A was used initially in PC clone computers by vendors who used clean BIOS designs. Because of the corrections in the chip, this part could not be used with a BIOS compatible with the INS8250 or INS8250B. INS82C50A This is a CMOS version (low power consumption) of the INS8250A and has similar functional characteristics. NS16450 Same as NS8250A with improvements so it can be used with faster CPU bus designs. IBM used this part in the IBM AT and updated the IBM BIOS to no longer rely on the bugs in the INS8250. NS16C450 This is a CMOS version (low power consumption) of the NS16450. NS16550 Same as NS16450 with a 16-byte send and receive buffer but the buffer design was flawed and could not be reliably be used. NS16550A Same as NS16550 with the buffer flaws corrected. The 16550A and its successors have become the most popular UART design in the PC industry, mainly due it its ability to reliably handle higher data rates on operating systems with sluggish interrupt response times. NS16C552 This component consists of two NS16C550A CMOS UARTs in a single package. PC16550D Same as NS16550A with subtle flaws corrected. This is revision D of the 16550 family and is the latest design available from National Semiconductor. The NS16550AF and the PC16550D are the same thing National reorganized their part numbering system a few years ago, and the NS16550AFN no longer exists by that name. (If you have a NS16550AFN, look at the date code on the part, which is a four digit number that usually starts with a nine. The first two digits of the number are the year, and the last two digits are the week in that year when the part was packaged. If you have a NS16550AFN, it is probably a few years old.) The new numbers are like PC16550DV, with minor differences in the suffix letters depending on the package material and its shape. (A description of the numbering system can be found below.) It is important to understand that in some stores, you may pay $15(US) for a NS16550AFN made in 1990 and in the next bin are the new PC16550DN parts with minor fixes that National has made since the AFN part was in production, the PC16550DN was probably made in the past six months and it costs half (as low as $5(US) in volume) as much as the NS16550AFN because they are readily available. As the supply of NS16550AFN chips continues to shrink, the price will probably continue to increase until more people discover and accept that the PC16550DN really has the same function as the old part number. National Semiconductor Part Numbering System The older NSnnnnnrqp part numbers are now of the format PCnnnnnrgp. The r is the revision field. The current revision of the 16550 from National Semiconductor is D. The p is the package-type field. The types are: "F" QFP (quad flat pack) L lead type "N" DIP (dual inline package) through hole straight lead type "V" LPCC (lead plastic chip carrier) J lead type The g is the product grade field. If an I precedes the package-type letter, it indicates an industrial grade part, which has higher specs than a standard part but not as high as Military Specification (Milspec) component. This is an optional field. So what we used to call a NS16550AFN (DIP Package) is now called a PC16550DN or PC16550DIN. Other Vendors and Similar UARTs Over the years, the 8250, 8250A, 16450 and 16550 have been licensed or copied by other chip vendors. In the case of the 8250, 8250A and 16450, the exact circuit (the megacell) was licensed to many vendors, including Western Digital and Intel. Other vendors reverse-engineered the part or produced emulations that had similar behavior. In internal modems, the modem designer will frequently emulate the 8250A/16450 with the modem microprocessor, and the emulated UART will frequently have a hidden buffer consisting of several hundred bytes. Because of the size of the buffer, these emulations can be as reliable as a 16550A in their ability to handle high speed data. However, most operating systems will still report that the UART is only a 8250A or 16450, and may not make effective use of the extra buffering present in the emulated UART unless special drivers are used. Some modem makers are driven by market forces to abandon a design that has hundreds of bytes of buffer and instead use a 16550A UART so that the product will compare favorably in market comparisons even though the effective performance may be lowered by this action. A common misconception is that all parts with 16550A written on them are identical in performance. There are differences, and in some cases, outright flaws in most of these 16550A clones. When the NS16550 was developed, the National Semiconductor obtained several patents on the design and they also limited licensing, making it harder for other vendors to provide a chip with similar features. Because of the patents, reverse-engineered designs and emulations had to avoid infringing the claims covered by the patents. Subsequently, these copies almost never perform exactly the same as the NS16550A or PC16550D, which are the parts most computer and modem makers want to buy but are sometimes unwilling to pay the price required to get the genuine part. Some of the differences in the clone 16550A parts are unimportant, while others can prevent the device from being used at all with a given operating system or driver. These differences may show up when using other drivers, or when particular combinations of events occur that were not well tested or considered in the Windows driver. This is because most modem vendors and 16550-clone makers use the Microsoft drivers from Windows for Workgroups 3.11 and the Microsoft MS-DOS utility as the primary tests for compatibility with the NS16550A. This over-simplistic criteria means that if a different operating system is used, problems could appear due to subtle differences between the clones and genuine components. National Semiconductor has made available a program named COMTEST that performs compatibility tests independent of any OS drivers. It should be remembered that the purpose of this type of program is to demonstrate the flaws in the products of the competition, so the program will report major as well as extremely subtle differences in behavior in the part being tested. In a series of tests performed by the author of this document in 1994, components made by National Semiconductor, TI, StarTech, and CMD as well as megacells and emulations embedded in internal modems were tested with COMTEST. A difference count for some of these components is listed below. Because these tests were performed in 1994, they may not reflect the current performance of the given product from a vendor. It should be noted that COMTEST normally aborts when an excessive number or certain types of problems have been detected. As part of this testing, COMTEST was modified so that it would not abort no matter how many differences were encountered. Vendor Part Number Errors (aka "differences" reported) National (PC16550DV) 0 National (NS16550AFN) 0 National (NS16C552V) 0 TI (TL16550AFN) 3 CMD (16C550PE) 19 StarTech (ST16C550J) 23 Rockwell Reference modem with internal 16550 or an emulation (RC144DPi/C3000-25) 117 Sierra Modem with an internal 16550 (SC11951/SC11351) 91 To date, the author of this document has not found any non-National parts that report zero differences using the COMTEST program. It should also be noted that National has had five versions of the 16550 over the years and the newest parts behave a bit differently than the classic NS16550AFN that is considered the benchmark for functionality. COMTEST appears to turn a blind eye to the differences within the National product line and reports no errors on the National parts (except for the original 16550) even when there are official erratas that describe bugs in the A, B and C revisions of the parts, so this bias in COMTEST must be taken into account. It is important to understand that a simple count of differences from COMTEST does not reveal a lot about what differences are important and which are not. For example, about half of the differences reported in the two modems listed above that have internal UARTs were caused by the clone UARTs not supporting five- and six-bit character modes. The real 16550, 16450, and 8250 UARTs all support these modes and COMTEST checks the functionality of these modes so over fifty differences are reported. However, almost no modern modem supports five- or six-bit characters, particularly those with error-correction and compression capabilities. This means that the differences related to five- and six-bit character modes can be discounted. Many of the differences COMTEST reports have to do with timing. In many of the clone designs, when the host reads from one port, the status bits in some other port may not update in the same amount of time (some faster, some slower) as a real NS16550AFN and COMTEST looks for these differences. This means that the number of differences can be misleading in that one device may only have one or two differences but they are extremely serious, and some other device that updates the status registers faster or slower than the reference part (that would probably never affect the operation of a properly written driver) could have dozens of differences reported. COMTEST can be used as a screening tool to alert the administrator to the presence of potentially incompatible components that might cause problems or have to be handled as a special case. If you run COMTEST on a 16550 that is in a modem or a modem is attached to the serial port, you need to first issue a ATE0&W command to the modem so that the modem will not echo any of the test characters. If you forget to do this, COMTEST will report at least this one difference: Error (6)...Timeout interrupt failed: IIR = c1 LSR = 61 8250/16450/16550 Registers The 8250/16450/16550 UART occupies eight contiguous I/O port addresses. In the IBM PC, there are two defined locations for these eight ports and they are known collectively as COM1 and COM2. The makers of PC-clones and add-on cards have created two additional areas known as COM3 and COM4, but these extra COM ports conflict with other hardware on some systems. The most common conflict is with video adapters that provide IBM 8514 emulation. COM1 is located from 0x3f8 to 0x3ff and normally uses IRQ 4 COM2 is located from 0x2f8 to 0x2ff and normally uses IRQ 3 COM3 is located from 0x3e8 to 0x3ef and has no standardized IRQ COM4 is located from 0x2e8 to 0x2ef and has no standardized IRQ. A description of the I/O ports of the 8250/16450/16550 UART is provided below. I/O Port Access Allowed Description +0x00 write (DLAB==0) Transmit Holding Register (THR).Information written to this port are treated as data words and will be transmitted by the UART. +0x00 read (DLAB==0) Receive Buffer Register (RBR).Any data words received by the UART form the serial link are accessed by the host by reading this port. +0x00 write/read (DLAB==1) Divisor Latch LSB (DLL)This value will be divided from the master input clock (in the IBM PC, the master clock is 1.8432MHz) and the resulting clock will determine the baud rate of the UART. This register holds bits 0 thru 7 of the divisor. +0x01 write/read (DLAB==1) Divisor Latch MSB (DLH)This value will be divided from the master input clock (in the IBM PC, the master clock is 1.8432MHz) and the resulting clock will determine the baud rate of the UART. This register holds bits 8 thru 15 of the divisor. +0x01 write/read (DLAB==0) Interrupt Enable Register (IER)The 8250/16450/16550 UART classifies events into one of four categories. Each category can be configured to generate an interrupt when any of the events occurs. The 8250/16450/16550 UART generates a single external interrupt signal regardless of how many events in the enabled categories have occurred. It is up to the host processor to respond to the interrupt and then poll the enabled interrupt categories (usually all categories have interrupts enabled) to determine the true cause(s) of the interrupt. Bit 7 Reserved, always 0. Bit 6 Reserved, always 0. Bit 5 Reserved, always 0. Bit 4 Reserved, always 0. Bit 3 Enable Modem Status Interrupt (EDSSI). Setting this bit to "1" allows the UART to generate an interrupt when a change occurs on one or more of the status lines. Bit 2 Enable Receiver Line Status Interrupt (ELSI) Setting this bit to "1" causes the UART to generate an interrupt when the an error (or a BREAK signal) has been detected in the incoming data. Bit 1 Enable Transmitter Holding Register Empty Interrupt (ETBEI) Setting this bit to "1" causes the UART to generate an interrupt when the UART has room for one or more additional characters that are to be transmitted. Bit 0 Enable Received Data Available Interrupt (ERBFI) Setting this bit to "1" causes the UART to generate an interrupt when the UART has received enough characters to exceed the trigger level of the FIFO, or the FIFO timer has expired (stale data), or a single character has been received when the FIFO is disabled. +0x02 write FIFO Control Register (FCR) (This port does not exist on the 8250 and 16450 UART.) Bit 7 Receiver Trigger Bit #1 Bit 6 Receiver Trigger Bit #0These two bits control at what point the receiver is to generate an interrupt when the FIFO is active. 7 6 How many words are received before an interrupt is generated 0 0 1 0 1 4 1 0 8 1 1 14 Bit 5 Reserved, always 0. Bit 4 Reserved, always 0. Bit 3 DMA Mode Select. If Bit 0 is set to "1" (FIFOs enabled), setting this bit changes the operation of the -RXRDY and -TXRDY signals from Mode 0 to Mode 1. Bit 2 Transmit FIFO Reset. When a "1" is written to this bit, the contents of the FIFO are discarded. Any word currently being transmitted will be sent intact. This function is useful in aborting transfers. Bit 1 Receiver FIFO Reset. When a "1" is written to this bit, the contents of the FIFO are discarded. Any word currently being assembled in the shift register will be received intact. Bit 0 16550 FIFO Enable. When set, both the transmit and receive FIFOs are enabled. Any contents in the holding register, shift registers or FIFOs are lost when FIFOs are enabled or disabled. +0x02 read Interrupt Identification Register Bit 7 FIFOs enabled. On the 8250/16450 UART, this bit is zero. Bit 6 FIFOs enabled. On the 8250/16450 UART, this bit is zero. Bit 5 Reserved, always 0. Bit 4 Reserved, always 0. Bit 3 Interrupt ID Bit #2. On the 8250/16450 UART, this bit is zero. Bit 2 Interrupt ID Bit #1 Bit 1 Interrupt ID Bit #0.These three bits combine to report the category of event that caused the interrupt that is in progress. These categories have priorities, so if multiple categories of events occur at the same time, the UART will report the more important events first and the host must resolve the events in the order they are reported. All events that caused the current interrupt must be resolved before any new interrupts will be generated. (This is a limitation of the PC architecture.) 2 1 0 Priority Description 0 1 1 First Received Error (OE, PE, BI, or FE) 0 1 0 Second Received Data Available 1 1 0 Second Trigger level identification (Stale data in receive buffer) 0 0 1 Third Transmitter has room for more words (THRE) 0 0 0 Fourth Modem Status Change (-CTS, -DSR, -RI, or -DCD) Bit 0 Interrupt Pending Bit. If this bit is set to "0", then at least one interrupt is pending. +0x03 write/read Line Control Register (LCR) Bit 7 Divisor Latch Access Bit (DLAB). When set, access to the data transmit/receive register (THR/RBR) and the Interrupt Enable Register (IER) is disabled. Any access to these ports is now redirected to the Divisor Latch Registers. Setting this bit, loading the Divisor Registers, and clearing DLAB should be done with interrupts disabled. Bit 6 Set Break. When set to "1", the transmitter begins to transmit continuous Spacing until this bit is set to "0". This overrides any bits of characters that are being transmitted. Bit 5 Stick Parity. When parity is enabled, setting this bit causes parity to always be "1" or "0", based on the value of Bit 4. Bit 4 Even Parity Select (EPS). When parity is enabled and Bit 5 is "0", setting this bit causes even parity to be transmitted and expected. Otherwise, odd parity is used. Bit 3 Parity Enable (PEN). When set to "1", a parity bit is inserted between the last bit of the data and the Stop Bit. The UART will also expect parity to be present in the received data. Bit 2 Number of Stop Bits (STB). If set to "1" and using 5-bit data words, 1.5 Stop Bits are transmitted and expected in each data word. For 6, 7 and 8-bit data words, 2 Stop Bits are transmitted and expected. When this bit is set to "0", one Stop Bit is used on each data word. Bit 1 Word Length Select Bit #1 (WLSB1) Bit 0 Word Length Select Bit #0 (WLSB0) Together these bits specify the number of bits in each data word. 1 0 Word Length 0 0 5 Data Bits 0 1 6 Data Bits 1 0 7 Data Bits 1 1 8 Data Bits +0x04 write/read Modem Control Register (MCR) Bit 7 Reserved, always 0. Bit 6 Reserved, always 0. Bit 5 Reserved, always 0. Bit 4 Loop-Back Enable. When set to "1", the UART transmitter and receiver are internally connected together to allow diagnostic operations. In addition, the UART modem control outputs are connected to the UART modem control inputs. CTS is connected to RTS, DTR is connected to DSR, OUT1 is connected to RI, and OUT 2 is connected to DCD. Bit 3 OUT 2. An auxiliary output that the host processor may set high or low. In the IBM PC serial adapter (and most clones), OUT 2 is used to tri-state (disable) the interrupt signal from the 8250/16450/16550 UART. Bit 2 OUT 1. An auxiliary output that the host processor may set high or low. This output is not used on the IBM PC serial adapter. Bit 1 Request to Send (RTS). When set to "1", the output of the UART -RTS line is Low (Active). Bit 0 Data Terminal Ready (DTR). When set to "1", the output of the UART -DTR line is Low (Active). +0x05 write/read Line Status Register (LSR) Bit 7 Error in Receiver FIFO. On the 8250/16450 UART, this bit is zero. This bit is set to "1" when any of the bytes in the FIFO have one or more of the following error conditions: PE, FE, or BI. Bit 6 Transmitter Empty (TEMT). When set to "1", there are no words remaining in the transmit FIFO or the transmit shift register. The transmitter is completely idle. Bit 5 Transmitter Holding Register Empty (THRE). When set to "1", the FIFO (or holding register) now has room for at least one additional word to transmit. The transmitter may still be transmitting when this bit is set to "1". Bit 4 Break Interrupt (BI). The receiver has detected a Break signal. Bit 3 Framing Error (FE). A Start Bit was detected but the Stop Bit did not appear at the expected time. The received word is probably garbled. Bit 2 Parity Error (PE). The parity bit was incorrect for the word received. Bit 1 Overrun Error (OE). A new word was received and there was no room in the receive buffer. The newly-arrived word in the shift register is discarded. On 8250/16450 UARTs, the word in the holding register is discarded and the newly- arrived word is put in the holding register. Bit 0 Data Ready (DR) One or more words are in the receive FIFO that the host may read. A word must be completely received and moved from the shift register into the FIFO (or holding register for 8250/16450 designs) before this bit is set. +0x06 write/read Modem Status Register (MSR) Bit 7 Data Carrier Detect (DCD). Reflects the state of the DCD line on the UART. Bit 6 Ring Indicator (RI). Reflects the state of the RI line on the UART. Bit 5 Data Set Ready (DSR). Reflects the state of the DSR line on the UART. Bit 4 Clear To Send (CTS). Reflects the state of the CTS line on the UART. Bit 3 Delta Data Carrier Detect (DDCD). Set to "1" - if the -DCD line has changed state one more more + if the -DCD line has changed state one more times since the last time the MSR was read by the host. Bit 2 Trailing Edge Ring Indicator (TERI). Set to "1" if the -RI line has had a low to high transition since the last time the MSR was read by the host. Bit 1 Delta Data Set Ready (DDSR). Set to "1" if the - -DSR line has changed state one more more times + -DSR line has changed state one more times since the last time the MSR was read by the host. Bit 0 Delta Clear To Send (DCTS). Set to "1" if the - -CTS line has changed state one more more times + -CTS line has changed state one more times since the last time the MSR was read by the host. +0x07 write/read Scratch Register (SCR). This register performs no function in the UART. Any value can be written by the host to this location and read by the host later on. Beyond the 16550A UART Although National Semiconductor has not offered any components compatible with the 16550 that provide additional features, various other vendors have. Some of these components are described below. It should be understood that to effectively utilize these improvements, drivers may have to be provided by the chip vendor since most of the popular operating systems do not support features beyond those provided by the 16550. ST16650 By default this part is similar to the NS16550A, but an extended 32-byte send and receive buffer can be optionally enabled. Made by StarTech. TIL16660 By default this part behaves similar to the NS16550A, but an extended 64-byte send and receive buffer can be optionally enabled. Made by Texas Instruments. Hayes ESP This proprietary plug-in card contains a 2048-byte send and receive buffer, and supports data rates to 230.4Kbit/sec. Made by Hayes. In addition to these dumb UARTs, many vendors produce intelligent serial communication boards. This type of design usually provides a microprocessor that interfaces with several UARTs, processes and buffers the data, and then alerts the main PC processor when necessary. Because the UARTs are not directly accessed by the PC processor in this type of communication system, it is not necessary for the vendor to use UARTs that are compatible with the 8250, 16450, or the 16550 UART. This leaves the designer free to components that may have better performance characteristics. Configuring the <devicename>sio</devicename> driver The sio driver provides support for NS8250-, NS16450-, NS16550 and NS16550A-based EIA RS-232C (CCITT V.24) communications interfaces. Several multiport cards are supported as well. See the &man.sio.4; manual page for detailed technical documentation. Digi International (DigiBoard) PC/8 Contributed by &a.awebster;. 26 August 1995. Here is a config snippet from a machine with a Digi International PC/8 with 16550. It has 8 modems connected to these 8 lines, and they work just great. Do not forget to add options COM_MULTIPORT or it will not work very well! device sio4 at isa? port 0x100 tty flags 0xb05 device sio5 at isa? port 0x108 tty flags 0xb05 device sio6 at isa? port 0x110 tty flags 0xb05 device sio7 at isa? port 0x118 tty flags 0xb05 device sio8 at isa? port 0x120 tty flags 0xb05 device sio9 at isa? port 0x128 tty flags 0xb05 device sio10 at isa? port 0x130 tty flags 0xb05 device sio11 at isa? port 0x138 tty flags 0xb05 irq 9 vector siointr The trick in setting this up is that the MSB of the flags represent the last SIO port, in this case 11 so flags are 0xb05. Boca 16 Contributed by &a.whiteside;. 26 August 1995. The procedures to make a Boca 16 port board with FreeBSD are pretty straightforward, but you will need a couple things to make it work: You either need the kernel sources installed so you can recompile the necessary options or you will need someone else to compile it for you. The 2.0.5 default kernel does not come with multiport support enabled and you will need to add a device entry for each port anyways. Two, you will need to know the interrupt and IO setting for your Boca Board so you can set these options properly in the kernel. One important note — the actual UART chips for the Boca 16 are in the connector box, not on the internal board itself. So if you have it unplugged, probes of those ports will fail. I have never tested booting with the box unplugged and plugging it back in, and I suggest you do not either. If you do not already have a custom kernel configuration file set up, refer to Kernel Configuration for general procedures. The following are the specifics for the Boca 16 board and assume you are using the kernel name MYKERNEL and editing with vi. Add the line options COM_MULTIPORT to the config file. Where the current device sion lines are, you will need to add 16 more devices. Only the last device includes the interrupt vector for the board. (See the &man.sio.4; manual page for detail as to why.) The following example is for a Boca Board with an interrupt of 3, and a base IO address 100h. The IO address for Each port is +8 hexadecimal from the previous port, thus the 100h, 108h, 110h... addresses. device sio1 at isa? port 0x100 tty flags 0x1005 device sio2 at isa? port 0x108 tty flags 0x1005 device sio3 at isa? port 0x110 tty flags 0x1005 device sio4 at isa? port 0x118 tty flags 0x1005 … device sio15 at isa? port 0x170 tty flags 0x1005 device sio16 at isa? port 0x178 tty flags 0x1005 irq 3 vector siointr The flags entry must be changed from this example unless you are using the exact same sio assignments. Flags are set according to 0xMYY where M indicates the minor number of the master port (the last port on a Boca 16) and YY indicates if FIFO is enabled or disabled(enabled), IRQ sharing is used(yes) and if there is an AST/4 compatible IRQ control register(no). In this example, flags 0x1005 indicates that the master port is sio16. If I added another board and assigned sio17 through sio28, the flags for all 16 ports on that board would be 0x1C05, where 1C indicates the minor number of the master port. Do not change the 05 setting. Save and complete the kernel configuration, recompile, install and reboot. Presuming you have successfully installed the recompiled kernel and have it set to the correct address and IRQ, your boot message should indicate the successful probe of the Boca ports as follows: (obviously the sio numbers, IO and IRQ could be different) sio1 at 0x100-0x107 flags 0x1005 on isa sio1: type 16550A (multiport) sio2 at 0x108-0x10f flags 0x1005 on isa sio2: type 16550A (multiport) sio3 at 0x110-0x117 flags 0x1005 on isa sio3: type 16550A (multiport) sio4 at 0x118-0x11f flags 0x1005 on isa sio4: type 16550A (multiport) sio5 at 0x120-0x127 flags 0x1005 on isa sio5: type 16550A (multiport) sio6 at 0x128-0x12f flags 0x1005 on isa sio6: type 16550A (multiport) sio7 at 0x130-0x137 flags 0x1005 on isa sio7: type 16550A (multiport) sio8 at 0x138-0x13f flags 0x1005 on isa sio8: type 16550A (multiport) sio9 at 0x140-0x147 flags 0x1005 on isa sio9: type 16550A (multiport) sio10 at 0x148-0x14f flags 0x1005 on isa sio10: type 16550A (multiport) sio11 at 0x150-0x157 flags 0x1005 on isa sio11: type 16550A (multiport) sio12 at 0x158-0x15f flags 0x1005 on isa sio12: type 16550A (multiport) sio13 at 0x160-0x167 flags 0x1005 on isa sio13: type 16550A (multiport) sio14 at 0x168-0x16f flags 0x1005 on isa sio14: type 16550A (multiport) sio15 at 0x170-0x177 flags 0x1005 on isa sio15: type 16550A (multiport) sio16 at 0x178-0x17f irq 3 flags 0x1005 on isa sio16: type 16550A (multiport master) If the messages go by too fast to see, &prompt.root; dmesg | more will show you the boot messages. Next, appropriate entries in /dev for the devices must be made using the /dev/MAKEDEV script. After becoming root: &prompt.root; cd /dev &prompt.root; ./MAKEDEV tty1 &prompt.root; ./MAKEDEV cua1 (everything in between) &prompt.root; ./MAKEDEV ttyg &prompt.root; ./MAKEDEV cuag If you do not want or need call-out devices for some reason, you can dispense with making the cua* devices. If you want a quick and sloppy way to make sure the devices are working, you can simply plug a modem into each port and (as root) &prompt.root; echo at > ttyd* for each device you have made. You should see the RX lights flash for each working port. Support for Cheap Multi-UART Cards Contributed by Helge Oldach hmo@sep.hamburg.com, September 1999 Ever wondered about FreeBSD support for your 20$ multi-I/O card with two (or more) COM ports, sharing IRQs? Here's how: Usually the only option to support these kind of boards is to use a distinct IRQ for each port. For example, if your CPU board has an on-board COM1 port (aka sio0–I/O address 0x3F8 and IRQ 4) and you have an extension board with two UARTs, you will commonly need to configure them as COM2 (aka sio1–I/O address 0x2F8 and IRQ 3), and the third port (aka sio2) as I/O 0x3E8 and IRQ 5. Obviously this is a waste of IRQ resources, as it should be basically possible to run both extension board ports using a single IRQ with the COM_MULTIPORT configuration described in the previous sections. Such cheap I/O boards commonly have a 4 by 3 jumper matrix for the COM ports, similar to the following: o o o * Port A | o * o * Port B | o * o o IRQ 2 3 4 5 Shown here is port A wired for IRQ 5 and port B wired for IRQ 3. The IRQ columns on your specific board may vary—other boards may supply jumpers for IRQs 3, 4, 5, and 7 instead. One could conclude that wiring both ports for IRQ 3 using a handcrafted wire-made jumper covering all three connection points in the IRQ 3 column would solve the issue, but no. You cannot duplicate IRQ 3 because the output drivers of each UART are wired in a totem pole fashion, so if one of the UARTs drives IRQ 3, the output signal will not be what you would expect. Depending on the implementation of the extension board or your motherboard, the IRQ 3 line will continuously stay up, or always stay low. You need to decouple the IRQ drivers for the two UARTs, so that the IRQ line of the board only goes up if (and only if) one of the UARTs asserts a IRQ, and stays low otherwise. The solution was proposed by Joerg Wunsch j@ida.interface-business.de: To solder up a wired-or consisting of two diodes (Germanium or Schottky-types strongly preferred) and a 1 kOhm resistor. Here is the schematic, starting from the 4 by 3 jumper field above: Diode +---------->|-------+ / | o * o o | 1 kOhm Port A +----|######|-------+ o * o o | | Port B `-------------------+ ==+== o * o o | Ground \ | +--------->|-------+ IRQ 2 3 4 5 Diode The cathodes of the diodes are connected to a common point, together with a 1 kOhm pull-down resistor. It is essential to connect the resistor to ground to avoid floating of the IRQ line on the bus. Now we are ready to configure a kernel. Staying with this example, we would configure: # standard on-board COM1 port device sio0 at isa? port "IO_COM1" tty flags 0x10 # patched-up multi-I/O extension board options COM_MULTIPORT device sio1 at isa? port "IO_COM2" tty flags 0x205 device sio2 at isa? port "IO_COM3" tty flags 0x205 irq 3 Note that the flags setting for sio1 and sio2 is truly essential; refer to &man.sio.4; for details. (Generally, the 2 in the "flags" attribute refers to sio2 which holds the IRQ, and you surely want a 5 low nibble.) With kernel verbose mode turned on this should yield something similar to this: sio0: irq maps: 0x1 0x11 0x1 0x1 sio0 at 0x3f8-0x3ff irq 4 flags 0x10 on isa sio0: type 16550A sio1: irq maps: 0x1 0x9 0x1 0x1 sio1 at 0x2f8-0x2ff flags 0x205 on isa sio1: type 16550A (multiport) sio2: irq maps: 0x1 0x9 0x1 0x1 sio2 at 0x3e8-0x3ef irq 3 flags 0x205 on isa sio2: type 16550A (multiport master) Though /sys/i386/isa/sio.c is somewhat cryptic with its use of the irq maps array above, the basic idea is that you observe 0x1 in the first, third, and fourth place. This means that the corresponding IRQ was set upon output and cleared after, which is just what we would expect. If your kernel does not display this behavior, most likely there is something wrong with your wiring. Configuring the <devicename>cy</devicename> driver Contributed by Alex Nash. 6 June 1996. The Cyclades multiport cards are based on the cy driver instead of the usual sio driver used by other multiport cards. Configuration is a simple matter of: Add the cy device to your kernel configuration (note that your irq and iomem settings may differ). device cy0 at isa? tty irq 10 iomem 0xd4000 iosiz 0x2000 vector cyintr Rebuild and install the new kernel. Make the device nodes by typing (the following example assumes an 8-port board): &prompt.root; cd /dev &prompt.root; for i in 0 1 2 3 4 5 6 7;do ./MAKEDEV cuac$i ttyc$i;done If appropriate, add dialup entries to /etc/ttys by duplicating serial device (ttyd) entries and using ttyc in place of ttyd. For example: ttyc0 "/usr/libexec/getty std.38400" unknown on insecure ttyc1 "/usr/libexec/getty std.38400" unknown on insecure ttyc2 "/usr/libexec/getty std.38400" unknown on insecure … ttyc7 "/usr/libexec/getty std.38400" unknown on insecure Reboot with the new kernel. Configuring the <devicename>si</devicename> driver Contributed by &a.nsayer;. 25 March 1998. The Specialix SI/XIO and SX multiport cards use the si driver. A single machine can have up to 4 host cards. The following host cards are supported: ISA SI/XIO host card (2 versions) EISA SI/XIO host card PCI SI/XIO host card ISA SX host card PCI SX host card Although the SX and SI/XIO host cards look markedly different, their functionality are basically the same. The host cards do not use I/O locations, but instead require a 32K chunk of memory. The factory configuration for ISA cards places this at 0xd0000-0xd7fff. They also require an IRQ. PCI cards will, of course, auto-configure themselves. You can attach up to 4 external modules to each host card. The external modules contain either 4 or 8 serial ports. They come in the following varieties: SI 4 or 8 port modules. Up to 57600 bps on each port supported. XIO 8 port modules. Up to 115200 bps on each port supported. One type of XIO module has 7 serial and 1 parallel port. SXDC 8 port modules. Up to 921600 bps on each port supported. Like XIO, a module is available with one parallel port as well. To configure an ISA host card, add the following line to your kernel configuration file, changing the numbers as appropriate: device si0 at isa? tty iomem 0xd0000 irq 11 Valid IRQ numbers are 9, 10, 11, 12 and 15 for SX ISA host cards and 11, 12 and 15 for SI/XIO ISA host cards. To configure an EISA or PCI host card, use this line: device si0 After adding the configuration entry, rebuild and install your new kernel. After rebooting with the new kernel, you need to make the device nodes in /dev. The MAKEDEV script will take care of this for you. Count how many total ports you have and type: &prompt.root; cd /dev &prompt.root; ./MAKEDEV ttyAnn cuaAnn (where nn is the number of ports) If you want login prompts to appear on these ports, you will need to add lines like this to /etc/ttys: ttyA01 "/usr/libexec/getty std.9600" vt100 on insecure Change the terminal type as appropriate. For modems, dialup or unknown is fine. * Parallel ports * Modems * Network cards * Keyboards Mice Contributed by Joel Sutton jsutton@bbcon.com.au January 2000 FreeBSD supports a variety of different mice via the PS/2, serial and USB ports. Most users choose to use the mouse daemon to handle their mouse because it allows interaction in both X and on the system console. For more information on the mouse daemon refer to &man.moused.8;. The examples throughout this section assume that the mouse daemon is being used. This section contains the names of specific products that the author has confirmed will work with FreeBSD. Other similar devices not listed may also be supported. PS/2 System Configuration To ensure that your PS/2 mouse functions correctly with the mouse daemon you will need to include the following text in /etc/rc.conf moused_enable="YES" moused_type="ps/2" moused_port="/dev/psm0" Known Compatible Devices Logitech First Mouse - Three Button Microsoft Serial - PS/2 Compatible Mouse Serial System Configuration To ensure that your serial mouse functions correctly with the mouse daemon you will need to include the following text in /etc/rc.conf. This example assumes that the mouse is connected to COM1: and can be automatically recognized by the mouse daemon. moused_enable="YES" moused_type="auto" moused_port="/dev/cuaa0" See the &man.moused.8; manual page for a detailed description of how to configure the mouse daemon to work with specific types of serial mice. Known Compatible Devices Generic Microsoft Compatible Mice Logitech First Mouse - Three Button Microsoft Serial - PS/2 Compatible Mouse USB System Configuration The USB device drivers are a relatively new addition to FreeBSD and have not yet been included in the GENERIC kernel. The following procedure is an example of how to setup the relevant drivers on a typical system. Add the ums device to the usb section of your kernel configuration. For example: controller usb0 controller uhci0 device ums0 Rebuild and install the new kernel. Make the device node by typing: &prompt.root; cd /dev &prompt.root; sh MAKEDEV ums0 Include the following text in /etc/rc.conf to ensure correct operation of the mouse daemon: moused_enable="YES" moused_type="auto" moused_port="/dev/ums0" Reboot the system. &prompt.root; shutdown -r now Known Compatible Devices Logitech TrackMan - Marble Wheel * Other ]]> Storage Devices Using ESDI hard disks Copyright © 1995, &a.wilko;. 24 September 1995. ESDI is an acronym that means Enhanced Small Device Interface. It is loosely based on the good old ST506/412 interface originally devised by Seagate Technology, the makers of the first affordable 5.25" winchester disk. The acronym says Enhanced, and rightly so. In the first place the speed of the interface is higher, 10 or 15 Mbits/second instead of the 5 Mbits/second of ST412 interfaced drives. Secondly some higher level commands are added, making the ESDI interface somewhat 'smarter' to the operating system driver writers. It is by no means as smart as SCSI by the way. ESDI is standardized by ANSI. Capacities of the drives are boosted by putting more sectors on each track. Typical is 35 sectors per track, high capacity drives I have seen were up to 54 sectors/track. Although ESDI has been largely obsoleted by IDE and SCSI interfaces, the availability of free or cheap surplus drives makes them ideal for low (or now) budget systems. Concepts of ESDI Physical connections The ESDI interface uses two cables connected to each drive. One cable is a 34 pin flat cable edge connector that carries the command and status signals from the controller to the drive and vice-versa. The command cable is daisy chained between all the drives. So, it forms a bus onto which all drives are connected. The second cable is a 20 pin flat cable edge connector that carries the data to and from the drive. This cable is radially connected, so each drive has its own direct connection to the controller. To the best of my knowledge PC ESDI controllers are limited to using a maximum of 2 drives per controller. This is compatibility feature(?) left over from the WD1003 standard that reserves only a single bit for device addressing. Device addressing On each command cable a maximum of 7 devices and 1 controller can be present. To enable the controller to uniquely identify which drive it addresses, each ESDI device is equipped with jumpers or switches to select the devices address. On PC type controllers the first drive is set to address 0, the second disk to address 1. Always make sure you set each disk to an unique address! So, on a PC with its two drives/controller maximum the first drive is drive 0, the second is drive 1. Termination The daisy chained command cable (the 34 pin cable remember?) needs to be terminated at the last drive on the chain. For this purpose ESDI drives come with a termination resistor network that can be removed or disabled by a jumper when it is not used. So, one and only one drive, the one at the farthest end of the command cable has its terminator installed/enabled. The controller automatically terminates the other end of the cable. Please note that this implies that the controller must be at one end of the cable and not in the middle. Using ESDI disks with FreeBSD Why is ESDI such a pain to get working in the first place? People who tried ESDI disks with FreeBSD are known to have developed a profound sense of frustration. A combination of factors works against you to produce effects that are hard to understand when you have never seen them before. This has also led to the popular legend ESDI and FreeBSD is a plain NO-GO. The following sections try to list all the pitfalls and solutions. ESDI speed variants As briefly mentioned before, ESDI comes in two speed flavors. The older drives and controllers use a 10 Mbits/second data transfer rate. Newer stuff uses 15 Mbits/second. It is not hard to imagine that 15 Mbits/second drive cause problems on controllers laid out for 10 Mbits/second. As always, consult your controller and drive documentation to see if things match. Stay on track Mainstream ESDI drives use 34 to 36 sectors per track. Most (older) controllers cannot handle more than this number of sectors. Newer, higher capacity, drives use higher numbers of sectors per track. For instance, I own a 670 MB drive that has 54 sectors per track. In my case, the controller could not handle this number of sectors. It proved to work well except that it only used 35 sectors on each track. This meant losing a lot of disk space. Once again, check the documentation of your hardware for more info. Going out-of-spec like in the example might or might not work. Give it a try or get another more capable controller. Hard or soft sectoring Most ESDI drives allow hard or soft sectoring to be selected using a jumper. Hard sectoring means that the drive will produce a sector pulse on the start of each new sector. The controller uses this pulse to tell when it should start to write or read. Hard sectoring allows a selection of sector size (normally 256, 512 or 1024 bytes per formatted sector). FreeBSD uses 512 byte sectors. The number of sectors per track also varies while still using the same number of bytes per formatted sector. The number of unformatted bytes per sector varies, dependent on your controller it needs more or less overhead bytes to work correctly. Pushing more sectors on a track of course gives you more usable space, but might give problems if your controller needs more bytes than the drive offers. In case of soft sectoring, the controller itself determines where to start/stop reading or writing. For ESDI hard sectoring is the default (at least on everything I came across). I never felt the urge to try soft sectoring. In general, experiment with sector settings before you install FreeBSD because you need to re-run the low-level format after each change. Low level formatting ESDI drives need to be low level formatted before they are usable. A reformat is needed whenever you figgle with the number of sectors/track jumpers or the physical orientation of the drive (horizontal, vertical). So, first think, then format. The format time must not be underestimated, for big disks it can take hours. After a low level format, a surface scan is done to find and flag bad sectors. Most disks have a manufacturer bad block list listed on a piece of paper or adhesive sticker. In addition, on most disks the list is also written onto the disk. Please use the manufacturer's list. It is much easier to remap a defect now than after FreeBSD is installed. Stay away from low-level formatters that mark all sectors of a track as bad as soon as they find one bad sector. Not only does this waste space, it also and more importantly causes you grief with bad144 (see the section on bad144). Translations Translations, although not exclusively a ESDI-only problem, might give you real trouble. Translations come in multiple flavors. Most of them have in common that they attempt to work around the limitations posed upon disk geometries by the original IBM PC/AT design (thanks IBM!). First of all there is the (in)famous 1024 cylinder limit. For a system to be able to boot, the stuff (whatever operating system) must be in the first 1024 cylinders of a disk. Only 10 bits are available to encode the cylinder number. For the number of sectors the limit is 64 (0-63). When you combine the 1024 cylinder limit with the 16 head limit (also a design feature) you max out at fairly limited disk sizes. To work around this problem, the manufacturers of ESDI PC controllers added a BIOS prom extension on their boards. This BIOS extension handles disk I/O for booting (and for some operating systems all disk I/O) by using translation. For instance, a big drive might be presented to the system as having 32 heads and 64 sectors/track. The result is that the number of cylinders is reduced to something below 1024 and is therefore usable by the system without problems. It is noteworthy to know that FreeBSD does not use the BIOS after its kernel has started. More on this later. A second reason for translations is the fact that most older system BIOSes could only handle drives with 17 sectors per track (the old ST412 standard). Newer system BIOSes usually have a user-defined drive type (in most cases this is drive type 47). Whatever you do to translations after reading this document, keep in mind that if you have multiple operating systems on the same disk, all must use the same translation While on the subject of translations, I have seen one controller type (but there are probably more like this) offer the option to logically split a drive in multiple partitions as a BIOS option. I had select 1 drive == 1 partition because this controller wrote this info onto the disk. On power-up it read the info and presented itself to the system based on the info from the disk. Spare sectoring Most ESDI controllers offer the possibility to remap bad sectors. During/after the low-level format of the disk bad sectors are marked as such, and a replacement sector is put in place (logically of course) of the bad one. In most cases the remapping is done by using N-1 sectors on each track for actual data storage, and sector N itself is the spare sector. N is the total number of sectors physically available on the track. The idea behind this is that the operating system sees a 'perfect' disk without bad sectors. In the case of FreeBSD this concept is not usable. The problem is that the translation from bad to good is performed by the BIOS of the ESDI controller. FreeBSD, being a true 32 bit operating system, does not use the BIOS after it has been booted. Instead, it has device drivers that talk directly to the hardware. So: don't use spare sectoring, bad block remapping or whatever it may be called by the controller manufacturer when you want to use the disk for FreeBSD. Bad block handling The preceding section leaves us with a problem. The controller's bad block handling is not usable and still FreeBSD's filesystems assume perfect media without any flaws. To solve this problem, FreeBSD use the bad144 tool. Bad144 (named after a Digital Equipment standard for bad block handling) scans a FreeBSD slice for bad blocks. Having found these bad blocks, it writes a table with the offending block numbers to the end of the FreeBSD slice. When the disk is in operation, the disk accesses are checked against the table read from the disk. Whenever a block number is requested that is in the bad144 list, a replacement block (also from the end of the FreeBSD slice) is used. In this way, the bad144 replacement scheme presents 'perfect' media to the FreeBSD filesystems. There are a number of potential pitfalls associated with the use of bad144. First of all, the slice cannot have more than 126 bad sectors. If your drive has a high number of bad sectors, you might need to divide it into multiple FreeBSD slices each containing less than 126 bad sectors. Stay away from low-level format programs that mark every sector of a track as bad when they find a flaw on the track. As you can imagine, the 126 limit is quickly reached when the low-level format is done this way. Second, if the slice contains the root filesystem, the slice should be within the 1024 cylinder BIOS limit. During the boot process the bad144 list is read using the BIOS and this only succeeds when the list is within the 1024 cylinder limit. The restriction is not that only the root filesystem must be within the 1024 cylinder limit, but rather the entire slice that contains the root filesystem. Kernel configuration ESDI disks are handled by the same wddriver as IDE and ST412 MFM disks. The wd driver should work for all WD1003 compatible interfaces. Most hardware is jumperable for one of two different I/O address ranges and IRQ lines. This allows you to have two wd type controllers in one system. When your hardware allows non-standard strappings, you can use these with FreeBSD as long as you enter the correct info into the kernel config file. An example from the kernel config file (they live in /sys/i386/conf BTW). # First WD compatible controller controller wdc0 at isa? port "IO_WD1" bio irq 14 vector wdintr disk wd0 at wdc0 drive 0 disk wd1 at wdc0 drive 1 # Second WD compatible controller controller wdc1 at isa? port "IO_WD2" bio irq 15 vector wdintr disk wd2 at wdc1 drive 0 disk wd3 at wdc1 drive 1 Particulars on ESDI hardware Adaptec 2320 controllers I successfully installed FreeBSD onto a ESDI disk controlled by a ACB-2320. No other operating system was present on the disk. To do so I low level formatted the disk using NEFMT.EXE (ftpable from www.adaptec.com) and answered NO to the question whether the disk should be formatted with a spare sector on each track. The BIOS on the ACD-2320 was disabled. I used the free configurable option in the system BIOS to allow the BIOS to boot it. Before using NEFMT.EXE I tried to format the disk using the ACB-2320 BIOS built-in formatter. This proved to be a show stopper, because it did not give me an option to disable spare sectoring. With spare sectoring enabled the FreeBSD installation process broke down on the bad144 run. Please check carefully which ACB-232xy variant you have. The x is either 0 or 2, indicating a controller without or with a floppy controller on board. The y is more interesting. It can either be a blank, a A-8 or a D. A blank indicates a plain 10 Mbits/second controller. An A-8 indicates a 15 Mbits/second controller capable of handling 52 sectors/track. A D means a 15 Mbits/second controller that can also handle drives with > 36 sectors/track (also 52 ?). All variations should be capable of using 1:1 interleaving. Use 1:1, FreeBSD is fast enough to handle it. Western Digital WD1007 controllers I successfully installed FreeBSD onto a ESDI disk controlled by a WD1007 controller. To be precise, it was a WD1007-WA2. Other variations of the WD1007 do exist. To get it to work, I had to disable the sector translation and the WD1007's onboard BIOS. This implied I could not use the low-level formatter built into this BIOS. Instead, I grabbed WDFMT.EXE from www.wdc.com Running this formatted my drive just fine. Ultrastor U14F controllers According to multiple reports from the net, Ultrastor ESDI boards work OK with FreeBSD. I lack any further info on particular settings. Further reading If you intend to do some serious ESDI hacking, you might want to have the official standard at hand: The latest ANSI X3T10 committee document is: Enhanced Small Device Interface (ESDI) [X3.170-1990/X3.170a-1991] [X3T10/792D Rev 11] On Usenet the newsgroup comp.periphs is a noteworthy place to look for more info. The World Wide Web (WWW) also proves to be a very handy info source: For info on Adaptec ESDI controllers see http://www.adaptec.com/. For info on Western Digital controllers see http://www.wdc.com/. Thanks to... Andrew Gordon for sending me an Adaptec 2320 controller and ESDI disk for testing. What is SCSI? Copyright © 1995, &a.wilko;. July 6, 1996. SCSI is an acronym for Small Computer Systems Interface. It is an ANSI standard that has become one of the leading I/O buses in the computer industry. The foundation of the SCSI standard was laid by Shugart Associates (the same guys that gave the world the first mini floppy disks) when they introduced the SASI bus (Shugart Associates Standard Interface). After some time an industry effort was started to come to a more strict standard allowing devices from different vendors to work together. This effort was recognized in the ANSI SCSI-1 standard. The SCSI-1 standard (approximately 1985) is rapidly becoming obsolete. The current standard is SCSI-2 (see Further reading), with SCSI-3 on the drawing boards. In addition to a physical interconnection standard, SCSI defines a logical (command set) standard to which disk devices must adhere. This standard is called the Common Command Set (CCS) and was developed more or less in parallel with ANSI SCSI-1. SCSI-2 includes the (revised) CCS as part of the standard itself. The commands are dependent on the type of device at hand. It does not make much sense of course to define a Write command for a scanner. The SCSI bus is a parallel bus, which comes in a number of variants. The oldest and most used is an 8 bit wide bus, with single-ended signals, carried on 50 wires. (If you do not know what single-ended means, do not worry, that is what this document is all about.) Modern designs also use 16 bit wide buses, with differential signals. This allows transfer speeds of 20Mbytes/second, on cables lengths of up to 25 meters. SCSI-2 allows a maximum bus width of 32 bits, using an additional cable. Quickly emerging are Ultra SCSI (also called Fast-20) and Ultra2 (also called Fast-40). Fast-20 is 20 million transfers per second (20 Mbytes/sec on a 8 bit bus), Fast-40 is 40 million transfers per second (40 Mbytes/sec on a 8 bit bus). Most hard drives sold today are single-ended Ultra SCSI (8 or 16 bits). Of course the SCSI bus not only has data lines, but also a number of control signals. A very elaborate protocol is part of the standard to allow multiple devices to share the bus in an efficient manner. In SCSI-2, the data is always checked using a separate parity line. In pre-SCSI-2 designs parity was optional. In SCSI-3 even faster bus types are introduced, along with a serial SCSI busses that reduces the cabling overhead and allows a higher maximum bus length. You might see names like SSA and fibre channel in this context. None of the serial buses are currently in widespread use (especially not in the typical FreeBSD environment). For this reason the serial bus types are not discussed any further. As you could have guessed from the description above, SCSI devices are intelligent. They have to be to adhere to the SCSI standard (which is over 2 inches thick BTW). So, for a hard disk drive for instance you do not specify a head/cylinder/sector to address a particular block, but simply the number of the block you want. Elaborate caching schemes, automatic bad block replacement etc are all made possible by this 'intelligent device' approach. On a SCSI bus, each possible pair of devices can communicate. Whether their function allows this is another matter, but the standard does not restrict it. To avoid signal contention, the 2 devices have to arbitrate for the bus before using it. The philosophy of SCSI is to have a standard that allows older-standard devices to work with newer-standard ones. So, an old SCSI-1 device should normally work on a SCSI-2 bus. I say Normally, because it is not absolutely sure that the implementation of an old device follows the (old) standard closely enough to be acceptable on a new bus. Modern devices are usually more well-behaved, because the standardization has become more strict and is better adhered to by the device manufacturers. Generally speaking, the chances of getting a working set of devices on a single bus is better when all the devices are SCSI-2 or newer. This implies that you do not have to dump all your old stuff when you get that shiny 2GB disk: I own a system on which a pre-SCSI-1 disk, a SCSI-2 QIC tape unit, a SCSI-1 helical scan tape unit and 2 SCSI-1 disks work together quite happily. From a performance standpoint you might want to separate your older and newer (=faster) devices however. Components of SCSI As said before, SCSI devices are smart. The idea is to put the knowledge about intimate hardware details onto the SCSI device itself. In this way, the host system does not have to worry about things like how many heads a hard disks has, or how many tracks there are on a specific tape device. If you are curious, the standard specifies commands with which you can query your devices on their hardware particulars. FreeBSD uses this capability during boot to check out what devices are connected and whether they need any special treatment. The advantage of intelligent devices is obvious: the device drivers on the host can be made in a much more generic fashion, there is no longer a need to change (and qualify!) drivers for every odd new device that is introduced. For cabling and connectors there is a golden rule: get good stuff. With bus speeds going up all the time you will save yourself a lot of grief by using good material. So, gold plated connectors, shielded cabling, sturdy connector hoods with strain reliefs etc are the way to go. Second golden rule: do no use cables longer than necessary. I once spent 3 days hunting down a problem with a flaky machine only to discover that shortening the SCSI bus by 1 meter solved the problem. And the original bus length was well within the SCSI specification. SCSI bus types From an electrical point of view, there are two incompatible bus types: single-ended and differential. This means that there are two different main groups of SCSI devices and controllers, which cannot be mixed on the same bus. It is possible however to use special converter hardware to transform a single-ended bus into a differential one (and vice versa). The differences between the bus types are explained in the next sections. In lots of SCSI related documentation there is a sort of jargon in use to abbreviate the different bus types. A small list: FWD: Fast Wide Differential FND: Fast Narrow Differential SE: Single Ended FN: Fast Narrow etc. With a minor amount of imagination one can usually imagine what is meant. Wide is a bit ambiguous, it can indicate 16 or 32 bit buses. As far as I know, the 32 bit variant is not (yet) in use, so wide normally means 16 bit. Fast means that the timing on the bus is somewhat different, so that on a narrow (8 bit) bus 10 Mbytes/sec are possible instead of 5 Mbytes/sec for 'slow' SCSI. As discussed before, bus speeds of 20 and 40 million transfers/second are also emerging (Fast-20 == Ultra SCSI and Fast-40 == Ultra2 SCSI). The data lines > 8 are only used for data transfers and device addressing. The transfers of commands and status messages etc are only performed on the lowest 8 data lines. The standard allows narrow devices to operate on a wide bus. The usable bus width is negotiated between the devices. You have to watch your device addressing closely when mixing wide and narrow. Single ended buses A single-ended SCSI bus uses signals that are either 5 Volts or 0 Volts (indeed, TTL levels) and are relative to a COMMON ground reference. A singled ended 8 bit SCSI bus has approximately 25 ground lines, who are all tied to a single `rail' on all devices. A standard single ended bus has a maximum length of 6 meters. If the same bus is used with fast-SCSI devices, the maximum length allowed drops to 3 meters. Fast-SCSI means that instead of 5Mbytes/sec the bus allows 10Mbytes/sec transfers. Fast-20 (Ultra SCSI) and Fast-40 allow for 20 and 40 million transfers/second respectively. So, F20 is 20 Mbytes/second on a 8 bit bus, 40 Mbytes/second on a 16 bit bus etc. For F20 the max bus length is 1.5 meters, for F40 it becomes 0.75 meters. Be aware that F20 is pushing the limits quite a bit, so you will quickly find out if your SCSI bus is electrically sound. If some devices on your bus use 'fast' to communicate your bus must adhere to the length restrictions for fast buses! It is obvious that with the newer fast-SCSI devices the bus length can become a real bottleneck. This is why the differential SCSI bus was introduced in the SCSI-2 standard. For connector pinning and connector types please refer to the SCSI-2 standard (see Further reading) itself, connectors etc are listed there in painstaking detail. Beware of devices using non-standard cabling. For instance Apple uses a 25pin D-type connecter (like the one on serial ports and parallel printers). Considering that the official SCSI bus needs 50 pins you can imagine the use of this connector needs some 'creative cabling'. The reduction of the number of ground wires they used is a bad idea, you better stick to 50 pins cabling in accordance with the SCSI standard. For Fast-20 and 40 do not even think about buses like this. Differential buses A differential SCSI bus has a maximum length of 25 meters. Quite a difference from the 3 meters for a single-ended fast-SCSI bus. The idea behind differential signals is that each bus signal has its own return wire. So, each signal is carried on a (preferably twisted) pair of wires. The voltage difference between these two wires determines whether the signal is asserted or de-asserted. To a certain extent the voltage difference between ground and the signal wire pair is not relevant (do not try 10 kVolts though). It is beyond the scope of this document to explain why this differential idea is so much better. Just accept that electrically seen the use of differential signals gives a much better noise margin. You will normally find differential buses in use for inter-cabinet connections. Because of the lower cost single ended is mostly used for shorter buses like inside cabinets. There is nothing that stops you from using differential stuff with FreeBSD, as long as you use a controller that has device driver support in FreeBSD. As an example, Adaptec marketed the AHA1740 as a single ended board, whereas the AHA1744 was differential. The software interface to the host is identical for both. Terminators Terminators in SCSI terminology are resistor networks that are used to get a correct impedance matching. Impedance matching is important to get clean signals on the bus, without reflections or ringing. If you once made a long distance telephone call on a bad line you probably know what reflections are. With 20Mbytes/sec traveling over your SCSI bus, you do not want signals echoing back. Terminators come in various incarnations, with more or less sophisticated designs. Of course, there are internal and external variants. Many SCSI devices come with a number of sockets in which a number of resistor networks can (must be!) installed. If you remove terminators from a device, carefully store them. You will need them when you ever decide to reconfigure your SCSI bus. There is enough variation in even these simple tiny things to make finding the exact replacement a frustrating business. There are also SCSI devices that have a single jumper to enable or disable a built-in terminator. There are special terminators you can stick onto a flat cable bus. Others look like external connectors, or a connector hood without a cable. So, lots of choice as you can see. There is much debate going on if and when you should switch from simple resistor (passive) terminators to active terminators. Active terminators contain slightly more elaborate circuit to give cleaner bus signals. The general consensus seems to be that the usefulness of active termination increases when you have long buses and/or fast devices. If you ever have problems with your SCSI buses you might consider trying an active terminator. Try to borrow one first, they reputedly are quite expensive. Please keep in mind that terminators for differential and single-ended buses are not identical. You should not mix the two variants. OK, and now where should you install your terminators? This is by far the most misunderstood part of SCSI. And it is by far the simplest. The rule is: every single line on the SCSI bus has 2 (two) terminators, one at each end of the bus. So, two and not one or three or whatever. Do yourself a favor and stick to this rule. It will save you endless grief, because wrong termination has the potential to introduce highly mysterious bugs. (Note the potential here; the nastiest part is that it may or may not work.) A common pitfall is to have an internal (flat) cable in a machine and also an external cable attached to the controller. It seems almost everybody forgets to remove the terminators from the controller. The terminator must now be on the last external device, and not on the controller! In general, every reconfiguration of a SCSI bus must pay attention to this. Termination is to be done on a per-line basis. This means if you have both narrow and wide buses connected to the same host adapter, you need to enable termination on the higher 8 bits of the bus on the adapter (as well as the last devices on each bus, of course). What I did myself is remove all terminators from my SCSI devices and controllers. I own a couple of external terminators, for both the Centronics-type external cabling and for the internal flat cable connectors. This makes reconfiguration much easier. On modern devices, sometimes integrated terminators are used. These things are special purpose integrated circuits that can be enabled or disabled with a control pin. It is not necessary to physically remove them from a device. You may find them on newer host adapters, sometimes they are software configurable, using some sort of setup tool. Some will even auto-detect the cables attached to the connectors and automatically set up the termination as necessary. At any rate, consult your documentation! Terminator power The terminators discussed in the previous chapter need power to operate properly. On the SCSI bus, a line is dedicated to this purpose. So, simple huh? Not so. Each device can provide its own terminator power to the terminator sockets it has on-device. But if you have external terminators, or when the device supplying the terminator power to the SCSI bus line is switched off you are in trouble. The idea is that initiators (these are devices that initiate actions on the bus, a discussion follows) must supply terminator power. All SCSI devices are allowed (but not required) to supply terminator power. To allow for un-powered devices on a bus, the terminator power must be supplied to the bus via a diode. This prevents the backflow of current to un-powered devices. To prevent all kinds of nastiness, the terminator power is usually fused. As you can imagine, fuses might blow. This can, but does not have to, lead to a non functional bus. If multiple devices supply terminator power, a single blown fuse will not put you out of business. A single supplier with a blown fuse certainly will. Clever external terminators sometimes have a LED indication that shows whether terminator power is present. In newer designs auto-restoring fuses that 'reset' themselves after some time are sometimes used. Device addressing Because the SCSI bus is, ehh, a bus there must be a way to distinguish or address the different devices connected to it. This is done by means of the SCSI or target ID. Each device has a unique target ID. You can select the ID to which a device must respond using a set of jumpers, or a dip switch, or something similar. Some SCSI host adapters let you change the target ID from the boot menu. (Yet some others will not let you change the ID from 7.) Consult the documentation of your device for more information. Beware of multiple devices configured to use the same ID. Chaos normally reigns in this case. A pitfall is that one of the devices sharing the same ID sometimes even manages to answer to I/O requests! For an 8 bit bus, a maximum of 8 targets is possible. The maximum is 8 because the selection is done bitwise using the 8 data lines on the bus. For wide buses this increases to the number of data lines (usually 16). A narrow SCSI device can not communicate with a SCSI device with a target ID larger than 7. This means it is generally not a good idea to move your SCSI host adapter's target ID to something higher than 7 (or your CDROM will stop working). The higher the SCSI target ID, the higher the priority the devices has. When it comes to arbitration between devices that want to use the bus at the same time, the device that has the highest SCSI ID will win. This also means that the SCSI host adapter usually uses target ID 7. Note however that the lower 8 IDs have higher priorities than the higher 8 IDs on a wide-SCSI bus. Thus, the order of target IDs is: [7 6 .. 1 0 15 14 .. 9 8] - on a wide-SCSI system. (If you you are wondering why the lower 8 + on a wide-SCSI system. (If you are wondering why the lower 8 have higher priority, read the previous paragraph for a hint.) For a further subdivision, the standard allows for Logical Units or LUNs for short. A single target ID may have multiple LUNs. For example, a tape device including a tape changer may have LUN 0 for the tape device itself, and LUN 1 for the tape changer. In this way, the host system can address each of the functional units of the tape changer as desired. Bus layout SCSI buses are linear. So, not shaped like Y-junctions, star topologies, rings, cobwebs or whatever else people might want to invent. One of the most common mistakes is for people with wide-SCSI host adapters to connect devices on all three connecters (external connector, internal wide connector, internal narrow connector). Don't do that. It may appear to work if you are really lucky, but I can almost guarantee that your system will stop functioning at the most unfortunate moment (this is also known as Murphy's law). You might notice that the terminator issue discussed earlier becomes rather hairy if your bus is not linear. Also, if you have more connectors than devices on your internal SCSI cable, make sure you attach devices on connectors on both ends instead of using the connectors in the middle and let one or both ends dangle. This will screw up the termination of the bus. The electrical characteristics, its noise margins and ultimately the reliability of it all are tightly related to linear bus rule. Stick to the linear bus rule! Using SCSI with FreeBSD About translations, BIOSes and magic... As stated before, you should first make sure that you have a electrically sound bus. When you want to use a SCSI disk on your PC as boot disk, you must aware of some quirks related to PC BIOSes. The PC BIOS in its first incarnation used a low level physical interface to the hard disk. So, you had to tell the BIOS (using a setup tool or a BIOS built-in setup) how your disk physically looked like. This involved stating number of heads, number of cylinders, number of sectors per track, obscure things like precompensation and reduced write current cylinder etc. One might be inclined to think that since SCSI disks are smart you can forget about this. Alas, the arcane setup issue is still present today. The system BIOS needs to know how to access your SCSI disk with the head/cyl/sector method in order to load the FreeBSD kernel during boot. The SCSI host adapter or SCSI controller you have put in your AT/EISA/PCI/whatever bus to connect your disk therefore has its own on-board BIOS. During system startup, the SCSI BIOS takes over the hard disk interface routines from the system BIOS. To fool the system BIOS, the system setup is normally set to No hard disk present. Obvious, isn't it? The SCSI BIOS itself presents to the system a so called translated drive. This means that a fake drive table is constructed that allows the PC to boot the drive. This translation is often (but not always) done using a pseudo drive with 64 heads and 32 sectors per track. By varying the number of cylinders, the SCSI BIOS adapts to the actual drive size. It is useful to note that 32 * 64 / 2 = the size of your drive in megabytes. The division by 2 is to get from disk blocks that are normally 512 bytes in size to Kbytes. Right. All is well now?! No, it is not. The system BIOS has another quirk you might run into. The number of cylinders of a bootable hard disk cannot be greater than 1024. Using the translation above, this is a show-stopper for disks greater than 1 GB. With disk capacities going up all the time this is causing problems. Fortunately, the solution is simple: just use another translation, e.g. with 128 heads instead of 32. In most cases new SCSI BIOS versions are available to upgrade older SCSI host adapters. Some newer adapters have an option, in the form of a jumper or software setup selection, to switch the translation the SCSI BIOS uses. It is very important that all operating systems on the disk use the same translation to get the right idea about where to find the relevant partitions. So, when installing FreeBSD you must answer any questions about heads/cylinders etc using the translated values your host adapter uses. Failing to observe the translation issue might lead to un-bootable systems or operating systems overwriting each others partitions. Using fdisk you should be able to see all partitions. You might have heard some talk of lying devices? Older FreeBSD kernels used to report the geometry of SCSI disks when booting. An example from one of my systems: aha0 targ 0 lun 0: <MICROP 1588-15MB1057404HSP4> sd0: 636MB (1303250 total sec), 1632 cyl, 15 head, 53 sec, bytes/sec 512 Newer kernels usually do not report this information. e.g. (bt0:0:0): "SEAGATE ST41651 7574" type 0 fixed SCSI 2 sd0(bt0:0:0): Direct-Access 1350MB (2766300 512 byte sectors) Why has this changed? This info is retrieved from the SCSI disk itself. Newer disks often use a technique called zone bit recording. The idea is that on the outer cylinders of the drive there is more space so more sectors per track can be put on them. This results in disks that have more tracks on outer cylinders than on the inner cylinders and, last but not least, have more capacity. You can imagine that the value reported by the drive when inquiring about the geometry now becomes suspect at best, and nearly always misleading. When asked for a geometry , it is nearly always better to supply the geometry used by the BIOS, or if the BIOS is never going to know about this disk, (e.g. it is not a booting disk) to supply a fictitious geometry that is convenient. SCSI subsystem design FreeBSD uses a layered SCSI subsystem. For each different controller card a device driver is written. This driver knows all the intimate details about the hardware it controls. The driver has a interface to the upper layers of the SCSI subsystem through which it receives its commands and reports back any status. On top of the card drivers there are a number of more generic drivers for a class of devices. More specific: a driver for tape devices (abbreviation: st), magnetic disks (sd), CDROMs (cd) etc. In case you are wondering where you can find this stuff, it all lives in /sys/scsi. See the man pages in section 4 for more details. The multi level design allows a decoupling of low-level bit banging and more high level stuff. Adding support for another piece of hardware is a much more manageable problem. Kernel configuration Dependent on your hardware, the kernel configuration file must contain one or more lines describing your host adapter(s). This includes I/O addresses, interrupts etc. Consult the man page for your adapter driver to get more info. Apart from that, check out /sys/i386/conf/LINT for an overview of a kernel config file. LINT contains every possible option you can dream of. It does not imply LINT will actually get you to a working kernel at all. Although it is probably stating the obvious: the kernel config file should reflect your actual hardware setup. So, interrupts, I/O addresses etc must match the kernel config file. During system boot messages will be displayed to indicate whether the configured hardware was actually found. Note that most of the EISA/PCI drivers (namely ahb, ahc, ncr and amd will automatically obtain the correct parameters from the host adapters themselves at boot time; thus, you just need to write, for instance, controller ahc0. An example loosely based on the FreeBSD 2.2.5-Release kernel config file LINT with some added comments (between []): # SCSI host adapters: `aha', `ahb', `aic', `bt', `nca' # # aha: Adaptec 154x # ahb: Adaptec 174x # ahc: Adaptec 274x/284x/294x # aic: Adaptec 152x and sound cards using the Adaptec AIC-6360 (slow!) # amd: AMD 53c974 based SCSI cards (e.g., Tekram DC-390 and 390T) # bt: Most Buslogic controllers # nca: ProAudioSpectrum cards using the NCR 5380 or Trantor T130 # ncr: NCR/Symbios 53c810/815/825/875 etc based SCSI cards # uha: UltraStore 14F and 34F # sea: Seagate ST01/02 8 bit controller (slow!) # wds: Western Digital WD7000 controller (no scatter/gather!). # [For an Adaptec AHA274x/284x/294x/394x etc controller] controller ahc0 [For an NCR/Symbios 53c875 based controller] controller ncr0 [For an Ultrastor adapter] controller uha0 at isa? port "IO_UHA0" bio irq ? drq 5 vector uhaintr # Map SCSI buses to specific SCSI adapters controller scbus0 at ahc0 controller scbus2 at ncr0 controller scbus1 at uha0 # The actual SCSI devices disk sd0 at scbus0 target 0 unit 0 [SCSI disk 0 is at scbus 0, LUN 0] disk sd1 at scbus0 target 1 [implicit LUN 0 if omitted] disk sd2 at scbus1 target 3 [SCSI disk on the uha0] disk sd3 at scbus2 target 4 [SCSI disk on the ncr0] tape st1 at scbus0 target 6 [SCSI tape at target 6] device cd0 at scbus? [the first ever CDROM found, no wiring] The example above tells the kernel to look for a ahc (Adaptec 274x) controller, then for an NCR/Symbios board, and so on. The lines following the controller specifications tell the kernel to configure specific devices but only attach them when they match the target ID and LUN specified on the corresponding bus. Wired down devices get first shot at the unit numbers so the first non wired down device, is allocated the unit number one greater than the highest wired down unit number for that kind of device. So, if you had a SCSI tape at target ID 2 it would be configured as st2, as the tape at target ID 6 is wired down to unit number 1. Wired down devices need not be found to get their unit number. The unit number for a wired down device is reserved for that device, even if it is turned off at boot time. This allows the device to be turned on and brought on-line at a later time, without rebooting. Notice that a device's unit number has no relationship with its target ID on the SCSI bus. Below is another example of a kernel config file as used by FreeBSD version < 2.0.5. The difference with the first example is that devices are not wired down. Wired down means that you specify which SCSI target belongs to which device. A kernel built to the config file below will attach the first SCSI disk it finds to sd0, the second disk to sd1 etc. If you ever removed or added a disk, all other devices of the same type (disk in this case) would 'move around'. This implies you have to change /etc/fstab each time. Although the old style still works, you are strongly recommended to use this new feature. It will save you a lot of grief whenever you shift your hardware around on the SCSI buses. So, when you re-use your old trusty config file after upgrading from a pre-FreeBSD2.0.5.R system check this out. [driver for Adaptec 174x] controller ahb0 at isa? bio irq 11 vector ahbintr [for Adaptec 154x] controller aha0 at isa? port "IO_AHA0" bio irq 11 drq 5 vector ahaintr [for Seagate ST01/02] controller sea0 at isa? bio irq 5 iomem 0xc8000 iosiz 0x2000 vector seaintr controller scbus0 device sd0 [support for 4 SCSI harddisks, sd0 up sd3] device st0 [support for 2 SCSI tapes] [for the CDROM] device cd0 #Only need one of these, the code dynamically grows Both examples support SCSI disks. If during boot more devices of a specific type (e.g. sd disks) are found than are configured in the booting kernel, the system will simply allocate more devices, incrementing the unit number starting at the last number wired down. If there are no wired down devices then counting starts at unit 0. Use man 4 scsi to check for the latest info on the SCSI subsystem. For more detailed info on host adapter drivers use e.g., man 4 ahc for info on the Adaptec 294x driver. Tuning your SCSI kernel setup Experience has shown that some devices are slow to respond to INQUIRY commands after a SCSI bus reset (which happens at boot time). An INQUIRY command is sent by the kernel on boot to see what kind of device (disk, tape, CDROM etc.) is connected to a specific target ID. This process is called device probing by the way. To work around the 'slow response' problem, FreeBSD allows a tunable delay time before the SCSI devices are probed following a SCSI bus reset. You can set this delay time in your kernel configuration file using a line like: options SCSI_DELAY=15 #Be pessimistic about Joe SCSI device This line sets the delay time to 15 seconds. On my own system I had to use 3 seconds minimum to get my trusty old CDROM drive to be recognized. Start with a high value (say 30 seconds or so) when you have problems with device recognition. If this helps, tune it back until it just stays working. Rogue SCSI devices Although the SCSI standard tries to be complete and concise, it is a complex standard and implementing things correctly is no easy task. Some vendors do a better job then others. This is exactly where the rogue devices come into view. Rogues are devices that are recognized by the FreeBSD kernel as behaving slightly (...) non-standard. Rogue devices are reported by the kernel when booting. An example for two of my cartridge tape units: Feb 25 21:03:34 yedi /kernel: ahb0 targ 5 lun 0: <TANDBERG TDC 3600 -06:> Feb 25 21:03:34 yedi /kernel: st0: Tandberg tdc3600 is a known rogue Mar 29 21:16:37 yedi /kernel: aha0 targ 5 lun 0: <ARCHIVE VIPER 150 21247-005> Mar 29 21:16:37 yedi /kernel: st1: Archive Viper 150 is a known rogue For instance, there are devices that respond to all LUNs on a certain target ID, even if they are actually only one device. It is easy to see that the kernel might be fooled into believing that there are 8 LUNs at that particular target ID. The confusion this causes is left as an exercise to the reader. The SCSI subsystem of FreeBSD recognizes devices with bad habits by looking at the INQUIRY response they send when probed. Because the INQUIRY response also includes the version number of the device firmware, it is even possible that for different firmware versions different workarounds are used. See e.g. /sys/scsi/st.c and /sys/scsi/scsiconf.c for more info on how this is done. This scheme works fine, but keep in mind that it of course only works for devices that are known to be weird. If you are the first to connect your bogus Mumbletech SCSI CDROM you might be the one that has to define which workaround is needed. After you got your Mumbletech working, please send the required workaround to the FreeBSD development team for inclusion in the next release of FreeBSD. Other Mumbletech owners will be grateful to you. Multiple LUN devices In some cases you come across devices that use multiple logical units (LUNs) on a single SCSI ID. In most cases FreeBSD only probes devices for LUN 0. An example are so called bridge boards that connect 2 non-SCSI harddisks to a SCSI bus (e.g. an Emulex MD21 found in old Sun systems). This means that any devices with LUNs != 0 are not normally found during device probe on system boot. To work around this problem you must add an appropriate entry in /sys/scsi/scsiconf.c and rebuild your kernel. Look for a struct that is initialized like below: { T_DIRECT, T_FIXED, "MAXTOR", "XT-4170S", "B5A", "mx1", SC_ONE_LU } For you Mumbletech BRIDGE2000 that has more than one LUN, acts as a SCSI disk and has firmware revision 123 you would add something like: { T_DIRECT, T_FIXED, "MUMBLETECH", "BRIDGE2000", "123", "sd", SC_MORE_LUS } The kernel on boot scans the inquiry data it receives against the table and acts accordingly. See the source for more info. Tagged command queuing Modern SCSI devices, particularly magnetic disks, support what is called tagged command queuing (TCQ). In a nutshell, TCQ allows the device to have multiple I/O requests outstanding at the same time. Because the device is intelligent, it can optimize its operations (like head positioning) based on its own request queue. On SCSI devices like RAID (Redundant Array of Independent Disks) arrays the TCQ function is indispensable to take advantage of the device's inherent parallelism. Each I/O request is uniquely identified by a tag (hence the name tagged command queuing) and this tag is used by FreeBSD to see which I/O in the device drivers queue is reported as complete by the device. It should be noted however that TCQ requires device driver support and that some devices implemented it not quite right in their firmware. This problem bit me once, and it leads to highly mysterious problems. In such cases, try to disable TCQ. Busmaster host adapters Most, but not all, SCSI host adapters are bus mastering controllers. This means that they can do I/O on their own without putting load onto the host CPU for data movement. This is of course an advantage for a multitasking operating system like FreeBSD. It must be noted however that there might be some rough edges. For instance an Adaptec 1542 controller can be set to use different transfer speeds on the host bus (ISA or AT in this case). The controller is settable to different rates because not all motherboards can handle the higher speeds. Problems like hang-ups, bad data etc might be the result of using a higher data transfer rate then your motherboard can stomach. The solution is of course obvious: switch to a lower data transfer rate and try if that works better. In the case of a Adaptec 1542, there is an option that can be put into the kernel config file to allow dynamic determination of the right, read: fastest feasible, transfer rate. This option is disabled by default: options "TUNE_1542" #dynamic tune of bus DMA speed Check the man pages for the host adapter that you use. Or better still, use the ultimate documentation (read: driver source). Tracking down problems The following list is an attempt to give a guideline for the most common SCSI problems and their solutions. It is by no means complete. Check for loose connectors and cables. Check and double check the location and number of your terminators. Check if your bus has at least one supplier of terminator power (especially with external terminators. Check if no double target IDs are used. Check if all devices to be used are powered up. Make a minimal bus config with as little devices as possible. If possible, configure your host adapter to use slow bus speeds. Disable tagged command queuing to make things as simple as possible (for a NCR host adapter based system see man ncrcontrol) If you can compile a kernel, make one with the SCSIDEBUG option, and try accessing the device with debugging turned on for that device. If your device does not even probe at startup, you may have to define the address of the device that is failing, and the desired debug level in /sys/scsi/scsidebug.h. If it probes but just does not work, you can use the &man.scsi.8; command to dynamically set a debug level to it in a running kernel (if SCSIDEBUG is defined). This will give you copious debugging output with which to confuse the gurus. See man 4 scsi for more exact information. Also look at man 8 scsi. Further reading If you intend to do some serious SCSI hacking, you might want to have the official standard at hand: Approved American National Standards can be purchased from ANSI at
13th Floor 11 West 42nd Street New York NY 10036 Sales Dept: (212) 642-4900
You can also buy many ANSI standards and most committee draft documents from Global Engineering Documents,
15 Inverness Way East Englewood CO, 80112-5704 Phone: (800) 854-7179 Outside USA and Canada: (303) 792-2181 Fax: (303) 792- 2192
Many X3T10 draft documents are available electronically on the SCSI BBS (719-574-0424) and on the ncrinfo.ncr.com anonymous ftp site. Latest X3T10 committee documents are: AT Attachment (ATA or IDE) [X3.221-1994] (Approved) ATA Extensions (ATA-2) [X3T10/948D Rev 2i] Enhanced Small Device Interface (ESDI) [X3.170-1990/X3.170a-1991] (Approved) Small Computer System Interface — 2 (SCSI-2) [X3.131-1994] (Approved) SCSI-2 Common Access Method Transport and SCSI Interface Module (CAM) [X3T10/792D Rev 11] Other publications that might provide you with additional information are: SCSI: Understanding the Small Computer System Interface, written by NCR Corporation. Available from: Prentice Hall, Englewood Cliffs, NJ, 07632 Phone: (201) 767-5937 ISBN 0-13-796855-8 Basics of SCSI, a SCSI tutorial written by Ancot Corporation Contact Ancot for availability information at: Phone: (415) 322-5322 Fax: (415) 322-0455 SCSI Interconnection Guide Book, an AMP publication (dated 4/93, Catalog 65237) that lists the various SCSI connectors and suggests cabling schemes. Available from AMP at (800) 522-6752 or (717) 564-0100 Fast Track to SCSI, A Product Guide written by Fujitsu. Available from: Prentice Hall, Englewood Cliffs, NJ, 07632 Phone: (201) 767-5937 ISBN 0-13-307000-X The SCSI Bench Reference, The SCSI Encyclopedia, and the SCSI Tutor, ENDL Publications, 14426 Black Walnut Court, Saratoga CA, 95070 Phone: (408) 867-6642 Zadian SCSI Navigator (quick ref. book) and Discover the Power of SCSI (First book along with a one-hour video and tutorial book), Zadian Software, Suite 214, 1210 S. Bascom Ave., San Jose, CA 92128, (408) 293-0800 On Usenet the newsgroups comp.periphs.scsi and comp.periphs are noteworthy places to look for more info. You can also find the SCSI-Faq there, which is posted periodically. Most major SCSI device and host adapter suppliers operate ftp sites and/or BBS systems. They may be valuable sources of information about the devices you own. * Disk/tape controllers * SCSI * IDE * Floppy Hard drives SCSI hard drives Contributed by &a.asami;. 17 February 1998. As mentioned in the SCSI section, virtually all SCSI hard drives sold today are SCSI-2 compliant and thus will work fine as long as you connect them to a supported SCSI host adapter. Most problems people encounter are either due to badly designed cabling (cable too long, star topology, etc.), insufficient termination, or defective parts. Please refer to the SCSI section first if your SCSI hard drive is not working. However, there are a couple of things you may want to take into account before you purchase SCSI hard drives for your system. Rotational speed Rotational speeds of SCSI drives sold today range from around 4,500RPM to 10,000RPM. Most of them are either 5,400RPM or 7,200RPM. Even though the 7,200RPM drives can generally transfer data faster, they run considerably hotter than their 5,400RPM counterparts. A large fraction of today's disk drive malfunctions are heat-related. If you do not have very good cooling in your PC case, you may want to stick with 5,400RPM or slower drives. Note that newer drives, with higher areal recording densities, can deliver much more bits per rotation than older ones. Today's top-of-line 5,400RPM drives can sustain a throughput comparable to 7,200RPM drives of one or two model generations ago. The number to find on the spec sheet for bandwidth is internal data (or transfer) rate. It is usually in megabits/sec so divide it by 8 and you'll get the rough approximation of how much megabytes/sec you can get out of the drive. (If you are a speed maniac and want a 10,000RPM drive for your cute little PC, be my guest; however, those drives become extremely hot. Don't even think about it if you don't have a fan blowing air directly at the drive or a properly ventilated disk enclosure.) Obviously, the latest 10,000RPM drives and 7,200RPM drives can deliver more data than the latest 5,400RPM drives, so if absolute bandwidth is the necessity for your applications, you have little choice but to get the faster drives. Also, if you need low latency, faster drives are better; not only do they usually have lower average seek times, but also the rotational delay is one place where slow-spinning drives can never beat a faster one. (The average rotational latency is half the time it takes to rotate the drive once; thus, it's 3 milliseconds for 10,000RPM drives, 4.2ms for 7,200RPM drives and 5.6ms for 5,400RPM drives.) Latency is seek time plus rotational delay. Make sure you understand whether you need low latency or more accesses per second, though; in the latter case (e.g., news servers), it may not be optimal to purchase one big fast drive. You can achieve similar or even better results by using the ccd (concatenated disk) driver to create a striped disk array out of multiple slower drives for comparable overall cost. Make sure you have adequate air flow around the drive, especially if you are going to use a fast-spinning drive. You generally need at least 1/2" (1.25cm) of spacing above and below a drive. Understand how the air flows through your PC case. Most cases have the power supply suck the air out of the back. See where the air flows in, and put the drive where it will have the largest volume of cool air flowing around it. You may need to seal some unwanted holes or add a new fan for effective cooling. Another consideration is noise. Many 7,200 or faster drives generate a high-pitched whine which is quite unpleasant to most people. That, plus the extra fans often required for cooling, may make 7,200 or faster drives unsuitable for some office and home environments. Form factor Most SCSI drives sold today are of 3.5" form factor. They come in two different heights; 1.6" (half-height) or 1" (low-profile). The half-height drive is the same height as a CDROM drive. However, don't forget the spacing rule mentioned in the previous section. If you have three standard 3.5" drive bays, you will not be able to put three half-height drives in there (without frying them, that is). Interface The majority of SCSI hard drives sold today are Ultra or Ultra-wide SCSI. The maximum bandwidth of Ultra SCSI is 20MB/sec, and Ultra-wide SCSI is 40MB/sec. There is no difference in max cable length between Ultra and Ultra-wide; however, the more devices you have on the same bus, the sooner you will start having bus integrity problems. Unless you have a well-designed disk enclosure, it is not easy to make more than 5 or 6 Ultra SCSI drives work on a single bus. On the other hand, if you need to connect many drives, going for Fast-wide SCSI may not be a bad idea. That will have the same max bandwidth as Ultra (narrow) SCSI, while electronically it's much easier to get it right. My advice would be: if you want to connect many disks, get wide SCSI drives; they usually cost a little more but it may save you down the road. (Besides, if you can't afford the cost difference, you shouldn't be building a disk array.) There are two variant of wide SCSI drives; 68-pin and 80-pin SCA (Single Connector Attach). The SCA drives don't have a separate 4-pin power connector, and also read the SCSI ID settings through the 80-pin connector. If you are really serious about building a large storage system, get SCA drives and a good SCA enclosure (dual power supply with at least one extra fan). They are more electronically sound than 68-pin counterparts because there is no stub of the SCSI bus inside the disk canister as in arrays built from 68-pin drives. They are easier to install too (you just need to screw the drive in the canister, instead of trying to squeeze in your fingers in a tight place to hook up all the little cables (like the SCSI ID and disk activity LED lines). * IDE hard drives Tape drives Contributed by &a.jmb;. 2 July 1996. General tape access commands &man.mt.1; provides generic access to the tape drives. Some of the more common commands are rewind, erase, and status. See the &man.mt.1; manual page for a detailed description. Controller Interfaces There are several different interfaces that support tape drives. The interfaces are SCSI, IDE, Floppy and Parallel Port. A wide variety of tape drives are available for these interfaces. Controllers are discussed in Disk/tape controllers. SCSI drives The &man.st.4; driver provides support for 8mm (Exabyte), 4mm (DAT: Digital Audio Tape), QIC (Quarter-Inch Cartridge), DLT (Digital Linear Tape), QIC Mini cartridge and 9-track (remember the big reels that you see spinning in Hollywood computer rooms) tape drives. See the &man.st.4; manual page for a detailed description. The drives listed below are currently being used by members of the FreeBSD community. They are not the only drives that will work with FreeBSD. They just happen to be the ones that we use. 4mm (DAT: Digital Audio Tape) Archive Python 28454 Archive Python 04687 HP C1533A HP C1534A HP 35450A HP 35470A HP 35480A SDT-5000 Wangtek 6200 8mm (Exabyte) EXB-8200 EXB-8500 EXB-8505 QIC (Quarter-Inch Cartridge) Archive Anaconda 2750 Archive Viper 60 Archive Viper 150 Archive Viper 2525 Tandberg TDC 3600 Tandberg TDC 3620 Tandberg TDC 3800 Tandberg TDC 4222 Wangtek 5525ES DLT (Digital Linear Tape) Digital TZ87 Mini-Cartridge Conner CTMS 3200 Exabyte 2501 Autoloaders/Changers Hewlett-Packard HP C1553A Autoloading DDS2 * IDE drives Floppy drives Conner 420R * Parallel port drives Detailed Information Archive Anaconda 2750 The boot message identifier for this drive is ARCHIVE ANCDA 2750 28077 -003 type 1 removable SCSI 2 This is a QIC tape drive. Native capacity is 1.35GB when using QIC-1350 tapes. This drive will read and write QIC-150 (DC6150), QIC-250 (DC6250), and QIC-525 (DC6525) tapes as well. Data transfer rate is 350kB/s using &man.dump.8;. Rates of 530kB/s have been reported when using Amanda Production of this drive has been discontinued. The SCSI bus connector on this tape drive is reversed from that on most other SCSI devices. Make sure that you have enough SCSI cable to twist the cable one-half turn before and after the Archive Anaconda tape drive, or turn your other SCSI devices upside-down. Two kernel code changes are required to use this drive. This drive will not work as delivered. If you have a SCSI-2 controller, short jumper 6. Otherwise, the drive behaves are a SCSI-1 device. When operating as a SCSI-1 device, this drive, locks the SCSI bus during some tape operations, including: fsf, rewind, and rewoffl. If you are using the NCR SCSI controllers, patch the file /usr/src/sys/pci/ncr.c (as shown below). Build and install a new kernel. *** 4831,4835 **** }; ! if (np->latetime>4) { /* ** Although we tried to wake it up, --- 4831,4836 ---- }; ! if (np->latetime>1200) { /* ** Although we tried to wake it up, Reported by: &a.jmb; Archive Python 28454 The boot message identifier for this drive is ARCHIVE Python 28454-XXX4ASB type 1 removable SCSI 2 density code 0x8c, 512-byte blocks This is a DDS-1 tape drive. Native capacity is 2.5GB on 90m tapes. Data transfer rate is XXX. This drive was repackaged by Sun Microsystems as model 595-3067. Reported by: Bob Bishop rb@gid.co.uk Throughput is in the 1.5 MByte/sec range, however this will drop if the disks and tape drive are on the same SCSI controller. Reported by: Robert E. Seastrom rs@seastrom.com Archive Python 04687 The boot message identifier for this drive is ARCHIVE Python 04687-XXX 6580 Removable Sequential Access SCSI-2 device This is a DAT-DDS-2 drive. Native capacity is 4GB when using 120m tapes. This drive supports hardware data compression. Switch 4 controls MRS (Media Recognition System). MRS tapes have stripes on the transparent leader. Switch 4 off enables MRS, on disables MRS. Parity is controlled by switch 5. Switch 5 on to enable parity control. Compression is enabled with Switch 6 off. It is possible to override compression with the SCSI MODE SELECT command (see &man.mt.1;). Data transfer rate is 800kB/s. Archive Viper 60 The boot message identifier for this drive is ARCHIVE VIPER 60 21116 -007 type 1 removable SCSI 1 This is a QIC tape drive. Native capacity is 60MB. Data transfer rate is XXX. Production of this drive has been discontinued. Reported by: Philippe Regnauld regnauld@hsc.fr Archive Viper 150 The boot message identifier for this drive is ARCHIVE VIPER 150 21531 -004 Archive Viper 150 is a known rogue type 1 removable SCSI 1. A multitude of firmware revisions exist for this drive. Your drive may report different numbers (e.g 21247 -005. This is a QIC tape drive. Native capacity is 150/250MB. Both 150MB (DC6150) and 250MB (DC6250) tapes have the recording format. The 250MB tapes are approximately 67% longer than the 150MB tapes. This drive can read 120MB tapes as well. It can not write 120MB tapes. Data transfer rate is 100kB/s This drive reads and writes DC6150 (150MB) and DC6250 (250MB) tapes. This drives quirks are known and pre-compiled into the scsi tape device driver (&man.st.4;). Under FreeBSD 2.2-CURRENT, use mt blocksize 512 to set the blocksize. (The particular drive had firmware revision 21247 -005. Other firmware revisions may behave differently) Previous versions of FreeBSD did not have this problem. Production of this drive has been discontinued. Reported by: Pedro A M Vazquez vazquez@IQM.Unicamp.BR &a.msmith; Archive Viper 2525 The boot message identifier for this drive is ARCHIVE VIPER 2525 25462 -011 type 1 removable SCSI 1 This is a QIC tape drive. Native capacity is 525MB. Data transfer rate is 180kB/s at 90 inches/sec. The drive reads QIC-525, QIC-150, QIC-120 and QIC-24 tapes. Writes QIC-525, QIC-150, and QIC-120. Firmware revisions prior to 25462 -011 are bug ridden and will not function properly. Production of this drive has been discontinued. Conner 420R The boot message identifier for this drive is Conner tape. This is a floppy controller, mini cartridge tape drive. Native capacity is XXXX Data transfer rate is XXX The drive uses QIC-80 tape cartridges. Reported by: Mark Hannon mark@seeware.DIALix.oz.au Conner CTMS 3200 The boot message identifier for this drive is CONNER CTMS 3200 7.00 type 1 removable SCSI 2. This is a mini cartridge tape drive. Native capacity is XXXX Data transfer rate is XXX The drive uses QIC-3080 tape cartridges. Reported by: Thomas S. Traylor tst@titan.cs.mci.com <ulink url="http://www.digital.com/info/Customer-Update/931206004.txt.html">DEC TZ87</ulink> The boot message identifier for this drive is DEC TZ87 (C) DEC 9206 type 1 removable SCSI 2 density code 0x19 This is a DLT tape drive. Native capacity is 10GB. This drive supports hardware data compression. Data transfer rate is 1.2MB/s. This drive is identical to the Quantum DLT2000. The drive firmware can be set to emulate several well-known drives, including an Exabyte 8mm drive. Reported by: &a.wilko; <ulink url="http://www.Exabyte.COM:80/Products/Minicartridge/2501/Rfeatures.html">Exabyte EXB-2501</ulink> The boot message identifier for this drive is EXABYTE EXB-2501 This is a mini-cartridge tape drive. Native capacity is 1GB when using MC3000XL mini cartridges. Data transfer rate is XXX This drive can read and write DC2300 (550MB), DC2750 (750MB), MC3000 (750MB), and MC3000XL (1GB) mini cartridges. WARNING: This drive does not meet the SCSI-2 specifications. The drive locks up completely in response to a SCSI MODE_SELECT command unless there is a formatted tape in the drive. Before using this drive, set the tape blocksize with &prompt.root; mt -f /dev/st0ctl.0 blocksize 1024 Before using a mini cartridge for the first time, the mini cartridge must be formated. FreeBSD 2.1.0-RELEASE and earlier: &prompt.root; /sbin/scsi -f /dev/rst0.ctl -s 600 -c "4 0 0 0 0 0" (Alternatively, fetch a copy of the scsiformat shell script from FreeBSD 2.1.5/2.2.) FreeBSD 2.1.5 and later: &prompt.root; /sbin/scsiformat -q -w /dev/rst0.ctl Right now, this drive cannot really be recommended for FreeBSD. Reported by: Bob Beaulieu ez@eztravel.com Exabyte EXB-8200 The boot message identifier for this drive is EXABYTE EXB-8200 252X type 1 removable SCSI 1 This is an 8mm tape drive. Native capacity is 2.3GB. Data transfer rate is 270kB/s. This drive is fairly slow in responding to the SCSI bus during boot. A custom kernel may be required (set SCSI_DELAY to 10 seconds). There are a large number of firmware configurations for this drive, some have been customized to a particular vendor's hardware. The firmware can be changed via EPROM replacement. Production of this drive has been discontinued. Reported by: &a.msmith; Exabyte EXB-8500 The boot message identifier for this drive is EXABYTE EXB-8500-85Qanx0 0415 type 1 removable SCSI 2 This is an 8mm tape drive. Native capacity is 5GB. Data transfer rate is 300kB/s. Reported by: Greg Lehey grog@lemis.de <ulink url="http://www.Exabyte.COM:80/Products/8mm/8505XL/Rfeatures.html">Exabyte EXB-8505</ulink> The boot message identifier for this drive is EXABYTE EXB-85058SQANXR1 05B0 type 1 removable SCSI 2 This is an 8mm tape drive which supports compression, and is upward compatible with the EXB-5200 and EXB-8500. Native capacity is 5GB. The drive supports hardware data compression. Data transfer rate is 300kB/s. Reported by: Glen Foster gfoster@gfoster.com Hewlett-Packard HP C1533A The boot message identifier for this drive is HP C1533A 9503 type 1 removable SCSI 2. This is a DDS-2 tape drive. DDS-2 means hardware data compression and narrower tracks for increased data capacity. Native capacity is 4GB when using 120m tapes. This drive supports hardware data compression. Data transfer rate is 510kB/s. This drive is used in Hewlett-Packard's SureStore 6000eU and 6000i tape drives and C1533A DDS-2 DAT drive. The drive has a block of 8 dip switches. The proper settings for FreeBSD are: 1 ON; 2 ON; 3 OFF; 4 ON; 5 ON; 6 ON; 7 ON; 8 ON. switch 1 switch 2 Result On On Compression enabled at power-on, with host control On Off Compression enabled at power-on, no host control Off On Compression disabled at power-on, with host control Off Off Compression disabled at power-on, no host control Switch 3 controls MRS (Media Recognition System). MRS tapes have stripes on the transparent leader. These identify the tape as DDS (Digital Data Storage) grade media. Tapes that do not have the stripes will be treated as write-protected. Switch 3 OFF enables MRS. Switch 3 ON disables MRS. See HP SureStore Tape Products and Hewlett-Packard Disk and Tape Technical Information for more information on configuring this drive. Warning: Quality control on these drives varies greatly. One FreeBSD core-team member has returned 2 of these drives. Neither lasted more than 5 months. Reported by: &a.se; Hewlett-Packard HP 1534A The boot message identifier for this drive is HP HP35470A T503 type 1 removable SCSI 2 Sequential-Access density code 0x13, variable blocks. This is a DDS-1 tape drive. DDS-1 is the original DAT tape format. Native capacity is 2GB when using 90m tapes. Data transfer rate is 183kB/s. The same mechanism is used in Hewlett-Packard's SureStore 2000i tape drive, C35470A DDS format DAT drive, C1534A DDS format DAT drive and HP C1536A DDS format DAT drive. The HP C1534A DDS format DAT drive has two indicator lights, one green and one amber. The green one indicates tape action: slow flash during load, steady when loaded, fast flash during read/write operations. The amber one indicates warnings: slow flash when cleaning is required or tape is nearing the end of its useful life, steady indicates an hard fault. (factory service required?) Reported by Gary Crutcher gcrutchr@nightflight.com Hewlett-Packard HP C1553A Autoloading DDS2 The boot message identifier for this drive is "". This is a DDS-2 tape drive with a tape changer. DDS-2 means hardware data compression and narrower tracks for increased data capacity. Native capacity is 24GB when using 120m tapes. This drive supports hardware data compression. Data transfer rate is 510kB/s (native). This drive is used in Hewlett-Packard's SureStore 12000e tape drive. The drive has two selectors on the rear panel. The selector closer to the fan is SCSI id. The other selector should be set to 7. There are four internal switches. These should be set: 1 ON; 2 ON; 3 ON; 4 OFF. At present the kernel drivers do not automatically change tapes at the end of a volume. This shell script can be used to change tapes: #!/bin/sh PATH="/sbin:/usr/sbin:/bin:/usr/bin"; export PATH usage() { echo "Usage: dds_changer [123456ne] raw-device-name echo "1..6 = Select cartridge" echo "next cartridge" echo "eject magazine" exit 2 } if [ $# -ne 2 ] ; then usage fi cdb3=0 cdb4=0 cdb5=0 case $1 in [123456]) cdb3=$1 cdb4=1 ;; n) ;; e) cdb5=0x80 ;; ?) usage ;; esac scsi -f $2 -s 100 -c "1b 0 0 $cdb3 $cdb4 $cdb5" Hewlett-Packard HP 35450A The boot message identifier for this drive is HP HP35450A -A C620 type 1 removable SCSI 2 Sequential-Access density code 0x13 This is a DDS-1 tape drive. DDS-1 is the original DAT tape format. Native capacity is 1.2GB. Data transfer rate is 160kB/s. Reported by: Mark Thompson mark.a.thompson@pobox.com Hewlett-Packard HP 35470A The boot message identifier for this drive is HP HP35470A 9 09 type 1 removable SCSI 2 This is a DDS-1 tape drive. DDS-1 is the original DAT tape format. Native capacity is 2GB when using 90m tapes. Data transfer rate is 183kB/s. The same mechanism is used in Hewlett-Packard's SureStore 2000i tape drive, C35470A DDS format DAT drive, C1534A DDS format DAT drive, and HP C1536A DDS format DAT drive. Warning: Quality control on these drives varies greatly. One FreeBSD core-team member has returned 5 of these drives. None lasted more than 9 months. Reported by: David Dawes dawes@rf900.physics.usyd.edu.au (9 09) Hewlett-Packard HP 35480A The boot message identifier for this drive is HP HP35480A 1009 type 1 removable SCSI 2 Sequential-Access density code 0x13. This is a DDS-DC tape drive. DDS-DC is DDS-1 with hardware data compression. DDS-1 is the original DAT tape format. Native capacity is 2GB when using 90m tapes. It cannot handle 120m tapes. This drive supports hardware data compression. Please refer to the section on HP C1533A for the proper switch settings. Data transfer rate is 183kB/s. This drive is used in Hewlett-Packard's SureStore 5000eU and 5000i tape drives and C35480A DDS format DAT drive.. This drive will occasionally hang during a tape eject operation (mt offline). Pressing the front panel button will eject the tape and bring the tape drive back to life. WARNING: HP 35480-03110 only. On at least two occasions this tape drive when used with FreeBSD 2.1.0, an IBM Server 320 and an 2940W SCSI controller resulted in all SCSI disk partitions being lost. The problem has not be analyzed or resolved at this time. <ulink url="http://www.sel.sony.com/SEL/ccpg/storage/tape/t5000.html">Sony SDT-5000</ulink> There are at least two significantly different models: one is a DDS-1 and the other DDS-2. The DDS-1 version is SDT-5000 3.02. The DDS-2 version is SONY SDT-5000 327M. The DDS-2 version has a 1MB cache. This cache is able to keep the tape streaming in almost any circumstances. The boot message identifier for this drive is SONY SDT-5000 3.02 type 1 removable SCSI 2 Sequential-Access density code 0x13 Native capacity is 4GB when using 120m tapes. This drive supports hardware data compression. Data transfer rate is depends upon the model or the drive. The rate is 630kB/s for the SONY SDT-5000 327M while compressing the data. For the SONY SDT-5000 3.02, the data transfer rate is 225kB/s. In order to get this drive to stream, set the blocksize to 512 bytes (mt blocksize 512) reported by Kenneth Merry ken@ulc199.residence.gatech.edu. SONY SDT-5000 327M information reported by Charles Henrich henrich@msu.edu. Reported by: &a.jmz; Tandberg TDC 3600 The boot message identifier for this drive is TANDBERG TDC 3600 =08: type 1 removable SCSI 2 This is a QIC tape drive. Native capacity is 150/250MB. This drive has quirks which are known and work around code is present in the scsi tape device driver (&man.st.4;). Upgrading the firmware to XXX version will fix the quirks and provide SCSI 2 capabilities. Data transfer rate is 80kB/s. IBM and Emerald units will not work. Replacing the firmware EPROM of these units will solve the problem. Reported by: &a.msmith; Tandberg TDC 3620 This is very similar to the Tandberg TDC 3600 drive. Reported by: &a.joerg; Tandberg TDC 3800 The boot message identifier for this drive is TANDBERG TDC 3800 =04Y Removable Sequential Access SCSI-2 device This is a QIC tape drive. Native capacity is 525MB. Reported by: &a.jhs; Tandberg TDC 4222 The boot message identifier for this drive is TANDBERG TDC 4222 =07 type 1 removable SCSI 2 This is a QIC tape drive. Native capacity is 2.5GB. The drive will read all cartridges from the 60 MB (DC600A) upwards, and write 150 MB (DC6150) upwards. Hardware compression is optionally supported for the 2.5 GB cartridges. This drives quirks are known and pre-compiled into the scsi tape device driver (&man.st.4;) beginning with FreeBSD 2.2-CURRENT. For previous versions of FreeBSD, use mt to read one block from the tape, rewind the tape, and then execute the backup program (mt fsr 1; mt rewind; dump ...) Data transfer rate is 600kB/s (vendor claim with compression), 350 KB/s can even be reached in start/stop mode. The rate decreases for smaller cartridges. Reported by: &a.joerg; Wangtek 5525ES The boot message identifier for this drive is WANGTEK 5525ES SCSI REV7 3R1 type 1 removable SCSI 1 density code 0x11, 1024-byte blocks This is a QIC tape drive. Native capacity is 525MB. Data transfer rate is 180kB/s. The drive reads 60, 120, 150, and 525MB tapes. The drive will not write 60MB (DC600 cartridge) tapes. In order to overwrite 120 and 150 tapes reliably, first erase (mt erase) the tape. 120 and 150 tapes used a wider track (fewer tracks per tape) than 525MB tapes. The extra width of the previous tracks is not overwritten, as a result the new data lies in a band surrounded on both sides by the previous data unless the tape have been erased. This drives quirks are known and pre-compiled into the scsi tape device driver (&man.st.4;). Other firmware revisions that are known to work are: M75D Reported by: Marc van Kempen marc@bowtie.nl REV73R1 Andrew Gordon Andrew.Gordon@net-tel.co.uk M75D Wangtek 6200 The boot message identifier for this drive is WANGTEK 6200-HS 4B18 type 1 removable SCSI 2 Sequential-Access density code 0x13 This is a DDS-1 tape drive. Native capacity is 2GB using 90m tapes. Data transfer rate is 150kB/s. Reported by: Tony Kimball alk@Think.COM * Problem drives CDROM drives Contributed by &a.obrien;. 23 November 1997. As mentioned in Jordan's Picks Generally speaking those in The FreeBSD Project prefer SCSI CDROM drives over IDE CDROM drives. However not all SCSI CDROM drives are equal. Some feel the quality of some SCSI CDROM drives have been deteriorating to that of IDE CDROM drives. Toshiba used to be the favored stand-by, but many on the SCSI mailing list have found displeasure with the 12x speed XM-5701TA as its volume (when playing audio CDROMs) is not controllable by the various audio player software. Another area where SCSI CDROM manufacturers are cutting corners is adherence to the SCSI specification. Many SCSI CDROMs will respond to multiple LUNs for its target address. Known violators include the 6x Teac CD-56S 1.0D. * Other * Other * PCMCIA diff --git a/en_US.ISO8859-1/books/handbook/ports/chapter.sgml b/en_US.ISO8859-1/books/handbook/ports/chapter.sgml index a5d0479b5a..063fc1ecc6 100644 --- a/en_US.ISO8859-1/books/handbook/ports/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/ports/chapter.sgml @@ -1,1254 +1,1254 @@ Installing Applications: Packages and Ports Synopsis There is only so much you can do with FreeBSD. If you are an operating systems developer then the base system likely contains everything you need. If that is not what you are planning to do with FreeBSD then you will probably want to install additional software—perhaps a web server, or a mail reader, or a graphical environment such as KDE or GNOME. If you have used a Unix system before you will know that the typical procedure for installing third party software goes something like this: Download the software, which might be distributed in source code format, or as a binary. Unpack the software from its distribution format (typically a tarball compressed with either &man.compress.1; or &man.gzip.1;). Locate the documentation (perhaps a README file, or some files in a doc/ subdirectory) and read up on how to install the software. If the software was distributed in source format, compile it. This may involve editing a Makefile, or running a configure script, and other work. Test and install the software. And that is only if everything goes well. If you are installing a software package that was not deliberately ported to FreeBSD you may even have to go in and edit the code to make it work properly. Should you want to, you can continue to install software the traditional way with FreeBSD. However, FreeBSD provides two technologies which can save you a lot of effort; packages and ports. At the time of writing, over 4,000 third party applications have been made available in this way. For any given application, the FreeBSD package for that application is a single file which you must download. The package contains pre-compiled copies of all the commands for the application, as well as any configuration files or documentation. A downloaded package file can be manipulated with FreeBSD pkg_* commands, such as &man.pkg.add.1; &man.pkg.delete.1;, &man.pkg.info.1;, and so on. Installing a new application can be carried out with a single command. A FreeBSD port for an application is a collection of files designed to automate the process of compiling an application from source code. Remember that there are a number of steps you would normally carry out if you compiled a program yourself (unpacking, patching, compiling, installing). The files that make up a port contain all the necessary information to alllow the system to do this for you. You run a handful of simple commands and the source code for the application is automatically downloaded, extracted, patched, compiled, and installed for you. In fact, the ports system can also be used to generate packages which can later be manipulated with the pkg_* commands. Both packages and ports understand dependencies. Suppose you want to install an application that depends on a specific library being installed. Both the application and the library have been made available as FreeBSD ports and packages. If you use the pkg_add command or the ports system to add the application, both will notice that the library has not been installed, and the commands will install the library first. Given that the two technologies are quite similar, you might be wondering why FreeBSD bothers with both. Packages and ports both have their own strengths, and which one you use will depend on your own preference. Package benefits A compressed package tarball is typically smaller than the compressed tarball containing the source code for the application. Packages do not require any additional compilation. For large applications, such as Mozilla, KDE, or GNOME this can be important, particularly if you are on a slow system. Packages do not require you to understand any of the process involved in compiling software on FreeBSD. Ports benefits Packages are normally compiled with conservative options, because they have to run on the maximum number of systems. By installing from the port, you can tweak the compilation options to (for example) generate code that is specific to a 686 processor. Some packages have compile time options relating to what they can and can't do. For example, Apache can be configured with a wide variety of different builtin options. By building from the port you do not have to accept the default options, and can set them yourself. In some cases, multiple packages will exist for the same application to specify certain settings. For example, Ghostscript is available as a ghostscript package and a ghostscript-nox11 package, depending on whether or not you have installed an X11 server. This sort of rough tweaking is possible with packages, but rapidly becomes impossible if an application has more than one or two different compile time options. The licensing conditions of some software distributions forbid binary distribution. They must be distributed as source code. Some people do not trust binary distributions. At least with source code, you can (in theory) read through it and look for potential problems yourself. If you have local patches, you will need the source in order to apply them. Some people like having code around, so they can read it if they get bored, hack it, borrow from it (license permitting, of course), and so on. To keep track of updated ports, subscribe to freebsd-ports. The remainder of this chapter will explain how to use packages and ports to install and manage third party software on FreeBSD. Finding your application Before you can install any applications you need to know what you want, and what the application is called. FreeBSD's list of available applications is growing all the time. Currently there are over 4,000 applications available as packages or ports. There are a number of ways to find what you want. The FreeBSD web site maintains an up-to-date searchable list of all the available applications, at http://www.FreeBSD.org/ports/. The name space is divided in to categories, and you may either search for an application by name (if you know it), or you can list all the applications available in a category. Dan Langille maintains FreshPorts, at http://www.freshports.org/. FreshPorts tracks changes to the applications in the ports tree as they happen, and allows you to watch one or more ports, and will send you an e-mail when they are updated. If you do not know the name of the application you want, try using a site like FreshMeat (http://www.freshmeat.net/) or AppWatch (http://www.appwatch.com/) to find an application, then check back at the FreeBSD site to see if the application has been ported yet. Using the Packages System Contributed by &a.chern;, April 30, 2001. Installing a Package You can use the &man.pkg.add.1; utility to install a FreeBSD software package from a local file or from a server on the network. Downloading a package and then installing it locally &prompt.root; ftp ftp2.freebsd.org Connected to ftp2.freebsd.org. 220 ftp2.freebsd.org FTP server (Version 6.00LS) ready. 331 Guest login ok, send your email address as password. 230- 230- This machine is in Vienna, VA, USA, hosted by Verio. 230- Questions? E-mail freebsd@vienna.verio.net. 230- 230- 230 Guest login ok, access restrictions apply. Remote system type is UNIX. Using binary mode to transfer files. ftp> cd /pub/FreeBSD/ports/packages/irc 250 CWD command successful. ftp> get xchat-1.7.1.tgz local: xchat-1.7.1.tgz remote: xchat-1.7.1.tgz 150 Opening BINARY mode data connection for 'xchat-1.7.1.tgz' (471488 bytes). 100% |**************************************************| 460 KB 00:00 ETA 226 Transfer complete. 471488 bytes received in 5.37 seconds (85.70 KB/s) ftp> exit &prompt.root; pkg_add xchat-1.7.1.tgz &prompt.root; If you don't have a source of local packages (such as a FreeBSD CD-ROM set) then it will probably be easier to use the -r option to &man.pkg.add.1;. This will cause the utility to automatically determine the correct object format and release and then to fetch and install the package from an FTP site. &prompt.root; pkg_add -r xchat-1.7.1 This would download the correct package and add it without any further user intervention. Package files are distributed in .tgz format. You can find them at ftp://ftp.freebsd.org/ports/packages, or on the FreeBSD CD-ROM distribution. Every CD on the FreeBSD 4-CD set (and PowerPak, etc) contains packages in the /packages directory. The layout of the packages is similar to that of the /usr/ports tree. Each category has its own directory, and every package can be found within the All directory. The directory structure of the package system is homologous to that of the ports; they work with each other to form the entire package/port system. Deleting a Package &prompt.root pkg_delete xchat-1.7.1 &prompt.root &man.pkg.delete.1; is the utility for removing previously installed software package distributions. Managing packages &man.pkg.info.1; a utility that lists and describes the various packages installed. &prompt.root pkg_info cvsup-bin-16.1 A general network file distribution system optimized for CV docbook-1.2 Meta-port for the different versions of the DocBook DTD ... &man.pkg.version.1; a utility that summarizes the versions of all installed packages. It compares the package version to the current version found in the ports tree. &prompt.root pkg_version cvsup-bin = docbook = ... The symbols in the second column indicate the relative age of the installed version and the version available in the local ports tree. = The version of the installed package matches that of the one found in the local ports tree. < The installed version is older then the one available in the ports tree. >The installed version is newer than the one found in the local ports tree. (local ports tree is probably out of date) ?The installed package cannot be found in the ports index. *There are multiple versions of the package. Miscellaneous &man.pkg.add.1; &man.pkg.delete.1; &man.pkg.info.1; &man.pkg.version.1; &man.pkg.create.1; All package information is stored within the /var/db/pkg directory. The listing of contents and descriptions of each package can be found within files in this directory. Using the Ports Collection The following sections provide basic instructions on using the ports collection to install or remove programs from your system. Installing Ports The first thing that should be explained when it comes to the Ports collection is what is actually meant by a skeleton. In a nutshell, a port skeleton is a minimal set of files that are needed for a program to compile and install cleanly on FreeBSD. Each port skeleton includes: A Makefile. The Makefile contains various statements that specify how the application should be compiled and where it should be installed on your system A distinfo file. This file contains information about the files that must be downloaded to build the - port, and checksums, to ensure that that files have not been + port, and checksums, to ensure that those files have not been corrupted during the download. A files directory. This directory contains patches to make the program compile and install on your FreeBSD system. Patches are basically small files that specify changes to particular files. They are in plain text format, and basically say Remove line 10 or Change line 26 to this .... Patches are also known as diffs because they are generated by the diff program. This directory may also contain other files used in building the port. A pkg-comment file. This is a one-line description of the program. A pkg-descr file. This is a more detailed, often multiple-line, description of the program. A pkg-plist file. This is a list of all the files that will be installed by the port. It also tells the ports system what files to remove upon deinstallation. Now that you have enough background information to know what the Ports collection is used for, you are ready to install your first port. There are two ways this can be done, and each is explained below. Before we get into that however, you will need to choose a port to install. There are a few ways to do this, with the easiest method being the ports listing on the FreeBSD web site. You can browse through the ports listed there or use the search function on the site. Each port also includes a description so you can read a bit about each port before deciding to install it. Another method is to use the whereis command. To use whereis, simply type whereis <program you want to install> at the prompt, and if it is found on your system, you will be told where it is, like so: &prompt.root; whereis xchat xchat: /usr/ports/irc/xchat &prompt.root; This tells us that xchat (an irc client) can be found in the /usr/ports/irc/xchat directory. Yet another way of finding a particular port is by using the Ports collection's built-in search mechanism. To use the search feature, you will need to be in the /usr/ports directory. Once in that directory, run make search key=program-name where program-name is the name of the program you want to find. For example, if you were looking for xchat: &prompt.root; cd /usr/ports &prompt.root; make search key=xchat Port: xchat-1.3.8 Path: /usr/ports/irc/xchat Info: An X11 IRC client using the GTK+ toolkit, and optionally, GNOME Maint: jim@FreeBSD.org Index: irc B-deps: XFree86-3.3.5 bzip2-0.9.5d gettext-0.10.35 giflib-4.1.0 glib-1.2.6 gmake-3.77 gtk-1.2.6 imlib-1.9.8 jpeg-6b png-1.0.3 tiff-3.5.1 R-deps: XFree86-3.3.5 gettext-0.10.35 giflib-4.1.0 glib-1.2.6 gtk-1.2.6 imlib-1.9.8 jpeg-6b png-1.0.3 tiff-3.5.1 The part of the output you want to pay particular attention to is the Path: line, since that tells you where to find it. The other information provided is not needed in order to install the port directly, so it will not be covered here. You must be the root user to install ports. Now that you have found a port you would like to install, you are ready to do the actual installation. Installing ports from a CDROM As you may have guessed from the title, everything described in this section assumes you have a FreeBSD CDROM set. If you do not, you can order one from the FreeBSD Mall. Assuming that your FreeBSD CDROM is in the drive and is mounted on /cdrom (and the mount point must be /cdrom), you are ready to install the port. To begin, change directories to the directory where the port you want to install lives: &prompt.root; cd /usr/ports/irc/xchat Once inside the xchat directory, you will see the port skeleton. The next step is to compile (also called build) the port. This is done by simply typing make at the prompt. Once you have done so, you should see something like this: &prompt.root; make >> xchat-1.3.8.tar.bz2 doesn't seem to exist on this system. >> Attempting to fetch from file:/cdrom/ports/distfiles/. ===> Extracting for xchat-1.3.8 >> Checksum OK for xchat-1.3.8.tar.bz2. ===> xchat-1.3.8 depends on executable: bzip2 - found ===> xchat-1.3.8 depends on executable: gmake - found ===> xchat-1.3.8 depends on shared library: gtk12.2 - found ===> xchat-1.3.8 depends on shared library: Imlib.5 - found ===> xchat-1.3.8 depends on shared library: X11.6 - found ===> Patching for xchat-1.3.8 ===> Applying FreeBSD patches for xchat-1.3.8 ===> Configuring for xchat-1.3.8 ... [configure output snipped] ... ===> Building for xchat-1.3.8 ... [compilation snipped] ... &prompt.root; Take notice that once the compile is complete you are returned to your prompt. The next step is to install the port. In order to install it, you simply need to tack one word onto the make command, and that word is install: &prompt.root; make install ===> Installing for xchat-1.3.8 ===> xchat-1.3.8 depends on shared library: gtk12.2 - found ===> xchat-1.3.8 depends on shared library: Imlib.5 - found ===> xchat-1.3.8 depends on shared library: X11.6 - found ... [install routines snipped] ... ===> Generating temporary packing list ===> Installing xchat docs in /usr/X11R6/share/doc/xchat ===> Registering installation for xchat-1.3.8 &prompt.root; Once you are returned to your prompt, you should be able to run the application you just installed. You can save an extra step by just running make install instead of make and make install as two separate steps. Please be aware that the licenses of a few ports do not allow for inclusion on the CDROM. This could be for various - reasons, including things such as as registration form needs + reasons, including things such as registration form needs to be filled out before downloading, if redistribution is not allowed, and so on. If you wish to install a port not included on the CDROM, you will need to be online in order to do so (see the next section). Installing ports from the Internet As with the last section, this section makes an assumption that you have a working Internet connection. If you do not, you will need to do the CDROM installation. Installing a port from the Internet is done exactly the same way as it would be if you were installing from a CDROM. The only difference between the two is that the program's source code is downloaded from the Internet instead of pulled from the CDROM. The steps involved are identical: &prompt.root; make install >> xchat-1.3.8.tar.bz2 doesn't seem to exist on this system. >> Attempting to fetch from http://xchat.org/files/v1.3/. Receiving xchat-1.3.8.tar.bz2 (305543 bytes): 100% 305543 bytes transferred in 2.9 seconds (102.81 Kbytes/s) ===> Extracting for xchat-1.3.8 >> Checksum OK for xchat-1.3.8.tar.bz2. ===> xchat-1.3.8 depends on executable: bzip2 - found ===> xchat-1.3.8 depends on executable: gmake - found ===> xchat-1.3.8 depends on shared library: gtk12.2 - found ===> xchat-1.3.8 depends on shared library: Imlib.5 - found ===> xchat-1.3.8 depends on shared library: X11.6 - found ===> Patching for xchat-1.3.8 ===> Applying FreeBSD patches for xchat-1.3.8 ===> Configuring for xchat-1.3.8 ... [configure output snipped] ... ===> Building for xchat-1.3.8 ... [compilation snipped] ... ===> Installing for xchat-1.3.8 ===> xchat-1.3.8 depends on shared library: gtk12.2 - found ===> xchat-1.3.8 depends on shared library: Imlib.5 - found ===> xchat-1.3.8 depends on shared library: X11.6 - found ... [install routines snipped] ... ===> Generating temporary packing list ===> Installing xchat docs in /usr/X11R6/share/doc/xchat ===> Registering installation for xchat-1.3.8 &prompt.root; As you can see, the only difference is the line that tells you where the system is fetching the port from. That about does it for installing ports onto your system. In the section you will learn how to remove a port from your system. Removing Installed Ports Now that you know how to install ports, you are probably wondering how to remove them, just in case you install one and later on you decide that you installed the wrong port. The next few paragraphs will cover just that. Now we will remove our previous example (which was xchat for those of you not paying attention). As with installing ports, the first thing you must do is change to the port directory, which if you remember was /usr/ports/irc/xchat. After you change directories, you are ready to uninstall xchat. This is done with the make deinstall command (makes sense right?): &prompt.root; cd /usr/ports/irc/xchat &prompt.root; make deinstall ===> Deinstalling for xchat-1.3.8 &prompt.root; That was easy enough. You have now managed to remove xchat from your system. If you would like to reinstall it, you can do so by running make reinstall from the /usr/ports/irc/xchat directory. Troubleshooting The following sections cover some of the more frequently asked questions about the Ports collection and some basic troubleshooting techniques, and what do to if a port is broken. Some Questions and Answers I thought this was going to be a discussion about modems??! Ah, you must be thinking of the serial ports on the back of your computer. We are using port here to mean the result of porting a program from one version of UNIX to another. What is a patch? A patch is a small file that specifies how to go from one version of a file to another. It contains plain text, and basically says things like delete line 23, add these two lines after line 468, or change line 197 to this. They are also known as diffs because they are generated by the diff program. What is all this about tarballs? It is a file ending in .tar, or with variations such as .tar.gz, .tar.Z, .tar.bz2, and even .tgz. Basically, it is a directory tree that has been archived into a single file (.tar) and optionally compressed (.gz). This technique was originally used for Tape ARchives (hence the name tar), but it is a widely used way of distributing program source code around the Internet. You can see what files are in them, or even extract them yourself by using the standard UNIX tar program, which comes with the base FreeBSD system, like this: &prompt.user; tar tvzf foobar.tar.gz &prompt.user; tar xzvf foobar.tar.gz &prompt.user; tar tvf foobar.tar &prompt.user; tar xvf foobar.tar And a checksum? It is a number generated by adding up all the data in the file you want to check. If any of the characters change, the checksum will no longer be equal to the total, so a simple comparison will allow you to spot the difference. I did what you said for compiling ports from a CDROM and it worked great until I tried to install the kermit port. &prompt.root; make install >> cku190.tar.gz doesn't seem to exist on this system. >> Attempting to fetch from ftp://kermit.columbia.edu/kermit/archives/. Why can it not be found? Have I got a dud CDROM? As was explained in the compiling ports from CDROM section, some ports cannot be put on the CDROM set due to licensing restrictions. Kermit is an example of that. The licensing terms for kermit do not allow us to put the tarball for it on the CDROM, so you will have to fetch it by hand—sorry! The reason why you got all those error messages was because you were not connected to the Internet at the time. Once you have downloaded it from any of the MASTER_SITES (listed in the Makefile), you can restart the install process. I did that, but when I tried to put it into /usr/ports/distfiles I got some error about not having permission. The ports mechanism looks for the tarball in /usr/ports/distfiles, but you will not be able to copy anything there because it is symlinked to the CDROM, which is read-only. You can tell it to look somewhere else by doing: &prompt.root; make DISTDIR=/where/you/put/it install Does the ports scheme only work if you have everything in /usr/ports? My system administrator says I must put everything under /u/people/guests/wurzburger, but it does not seem to work. You can use the PORTSDIR and PREFIX variables to tell the ports mechanism to use different directories. For instance, &prompt.root; make PORTSDIR=/u/people/guests/wurzburger/ports install will compile the port in /u/people/guests/wurzburger/ports and install everything under /usr/local. &prompt.root; make PREFIX=/u/people/guests/wurzburger/local install will compile it in /usr/ports and install it in /u/people/guests/wurzburger/local. And of course, &prompt.root; make PORTSDIR=../ports PREFIX=../local install will combine the two (it is too long to write fully on the page, but it should give you the general idea). Some ports that use &man.imake.1; (a part of the X Windows System) don't work well with PREFIX, and will insist on installing under /usr/X11R6. Similarly, some Perl ports ignore PREFIX and install in the Perl tree. Making these ports respect PREFIX is a difficult or impossible job. If you do not fancy typing all that in every time you install a port, it is a good idea to put these variables into your environment. Read the man page for your shell for instructions on doing so. I do not have a FreeBSD CDROM, but I would like to have all the tarballs handy on my system so I do not have to wait for a download every time I install a port. Is there any way to get them all at once? To get every single tarball for the Ports collection, do: &prompt.root; cd /usr/ports &prompt.root; make fetch For all the tarballs for a single ports directory, do: &prompt.root; cd /usr/ports/directory &prompt.root; make fetch and for just one port—well, you have probably guessed already. I know it is probably faster to fetch the tarballs from one of the FreeBSD mirror sites close by. Is there any way to tell the port to fetch them from servers other than the ones listed in the MASTER_SITES? Yes. If you know, for example, that ftp.FreeBSD.org is much closer to you than the sites listed in MASTER_SITES, do as follows: &prompt.root; cd /usr/ports/directory &prompt.root; make MASTER_SITE_OVERRIDE= \ ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/ fetch I want to know what files make is going to need before it tries to pull them down. make fetch-list will display a list of the files needed for a port. Is there any way to stop the port from compiling? I want to do some hacking on the source before I install it, but it is a bit tiresome to watch it and hit control-C every time. Doing make extract will stop it after it has fetched and extracted the source code. I am trying to make my own port and I want to be able to stop it compiling until I have had a chance to see if my patches worked properly. Is there something like make extract, but for patches? Yep, make patch is what you want. You will probably find the PATCH_DEBUG option useful as well. And by the way, thank you for your efforts! I have heard that some compiler options can cause bugs. Is this true? How can I make sure that I compile ports with the right settings? Yes, with version 2.6.3 of gcc (the version shipped with FreeBSD 2.1.0 and 2.1.5), the option could result in buggy code unless you used the option as well. (Most of the ports do not use ). You should be able to specify the compiler options used by something like: &prompt.root; make CFLAGS='-O2 -fno-strength-reduce' install or by editing /etc/make.conf, but unfortunately not all ports respect this. The surest way is to do make configure, then go into the source directory and inspect the Makefiles by hand, but this can get tedious if the source has lots of sub-directories, each with their own Makefiles. The default FreeBSD compiler options are quite conservative, so if you have not changed them you should not have any problems. There are so many ports it is hard to find the one I want. Is there a list anywhere of what ports are available? Look in the INDEX file in /usr/ports. If you would like to search the ports collection for a keyword, you can do that too. For example, you can find ports relevant to the LISP programming language using: &prompt.user; cd /usr/ports &prompt.user; make search key=lisp I went to install the foo port but the system suddenly stopped compiling it and starting compiling the bar port. What is going on? The foo port needs something that is supplied with bar — for instance, if foo uses graphics, bar might have a library with useful graphics processing routines. Or bar might be a tool that is needed to compile the foo port. I installed the grizzle program from the ports and frankly it is a complete waste of disk space. I want to delete it but I do not know where it put all the files. Any clues? No problem, just do: &prompt.root; pkg_delete grizzle-6.5 Alternatively, you can do: &prompt.root; cd /usr/ports/somewhere/grizzle &prompt.root; make deinstall Hang on a minute, you have to know the version number to use that command. You do not seriously expect me to remember that, do you?? Not at all, you can find it out by doing: &prompt.root; pkg_info -a | grep grizzle Information for grizzle-6.5: grizzle-6.5 - the combined piano tutorial, LOGO interpreter and shoot 'em up arcade game. Talking of disk space, the ports directory seems to be taking up an awful lot of room. Is it safe to go in there and delete things? Yes, if you have installed the program and are fairly certain you will not need the source again, there is no point in keeping it hanging around. The best way to do this is: &prompt.root; cd /usr/ports &prompt.root; make clean which will go through all the ports subdirectories and delete everything except the skeletons for each port. I tried that and it still left all those tarballs or whatever you called them in the distfiles directory. Can I delete those as well? Yes, if you are sure you have finished with them, those can go as well. They can be removed manually, or by using make distclean. I like having lots and lots of programs to play with. Is there any way of installing all the ports in one go? Just do: &prompt.root; cd /usr/ports &prompt.root; make install Be careful, as some ports may install files with the same name. If you install two graphics ports and they both install /usr/local/bin/plot then you will obviously have problems. OK, I tried that, but I thought it would take a very long time so I went to bed and left it to get on with it. When I looked at the computer this morning, it had only done three and a half ports. Did something go wrong? No, the problem is that some of the ports need to ask you questions that we cannot answer for you (e.g., Do you want to print on A4 or US letter sized paper?) and they need to have someone on hand to answer them. I really do not want to spend all day staring at the monitor. Any better ideas? OK, do this before you go to bed/work/the local park: &prompt.root cd /usr/ports &prompt.root; make -DBATCH install This will install every port that does not require user input. Then, when you come back, do: &prompt.root; cd /usr/ports &prompt.root; make -DIS_INTERACTIVE install to finish the job. At work, we are using frobble, which is in your Ports collection, but we have altered it quite a bit to get it to do what we need. Is there any way of making our own packages, so we can distribute it more easily around our sites? No problem, assuming you know how to make patches for your changes: &prompt.root; cd /usr/ports/somewhere/frobble &prompt.root; make extract &prompt.root; cd work/frobble-2.8 [Apply your patches] &prompt.root; cd ../.. &prompt.root; make package This ports stuff is really clever. I am desperate to find out how you did it. What is the secret? Nothing secret about it at all, just look at the bsd.port.mk and bsd.port.subdir.mk files in your makefiles directory. (Readers with an aversion to intricate shell-scripts are advised not to follow this link...) Help! This port is broken! If you come across a port that doesn't work for you, there are a few things you can do, including: Fix it! The how to make a port section should help you do this. Gripe—by email only! Send email to the maintainer of the port first. Type make maintainer or read the Makefile to find the maintainer's email address. Remember to include the name and version of the port (send the $FreeBSD: line from the Makefile) and the output leading up to the error when you email the maintainer. If you do not get a response from the maintainer, you can use send-pr to submit a bug report. Forget about it. This is the easiest route—very few ports can be classified as essential. There's also a good chance any problems will be fixed in the next version when the port is updated. Grab the package from an ftp site near you. The master package collection is on ftp.FreeBSD.org in the packages directory, but be sure to check your local mirror first! These are more likely to work than trying to compile from source and are a lot faster as well. Use the &man.pkg.add.1; program to install the package on your system. Advanced Topics The documentation that was here has been moved to its own Porter's Handbook for ease of reference. Please go there if you wish to create and submit your own ports. diff --git a/en_US.ISO8859-1/books/handbook/ppp-and-slip/chapter.sgml b/en_US.ISO8859-1/books/handbook/ppp-and-slip/chapter.sgml index b89c535ebe..98e7f71b45 100644 --- a/en_US.ISO8859-1/books/handbook/ppp-and-slip/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/ppp-and-slip/chapter.sgml @@ -1,2778 +1,2778 @@ PPP and SLIP Restructured, reorganized, and updated by &a.jim;, 1 March 2000. Synopsis If you are connecting to the Internet via modem, or wish to provide dial-up connections to the Internet for others using FreeBSD, you have the option of using PPP or SLIP. This chapter covers three varieties of PPP; user, kernel, and PPPoE (PPP over Ethernet). It also covers setting up a SLIP client and server. The first variety of PPP that will be covered is User PPP. User PPP was introduced into FreeBSD in 2.0.5-RELEASE as an addition to the already existing kernel implementation of PPP. You may be wondering what the main difference is between User PPP and kernel PPP. The answer is simple; user PPP does not run as a daemon, and can run as and when desired. No PPP interface needs to be compiled into their kernel; it runs as a user process, and uses the tunnel device driver (tun) to get data into and out of the kernel. From here on out in this chapter, user ppp will simply be referred to as ppp unless a distinction needs to be made between it - and and any other PPP software such as pppd. + and any other PPP software such as pppd. Unless otherwise stated, all of the commands explained in this section should be executed as root. Using User PPP Originally contributed by &a.brian;, with input from &a.nik;, &a.dirkvangulik;, and &a.pjc;. User PPP Assumptions This document assumes you have the following: An account with an Internet Service Provider (ISP) which you connect to using PPP. Further, you have a modem or other device connected to your system and configured correctly, which allows you to connect to your ISP. The dial-up number(s) of your ISP. Your login name and password. This can be either a regular UNIX-style login and password pair, or a PAP or CHAP login and password pair. The IP address(es) of one or more name servers. Normally, you will be given two IP addresses by your ISP to use for this. If they have not given you at least one, then you can use the enable dns command in your ppp.conf file to tell ppp to set the name servers for you. The following information may be supplied by your ISP, but is not completely necessary: The IP address of your ISP's gateway. The gateway is the machine to which you will connect and will be set up as your default route. If you do not have this information, we can make one up and your ISP's PPP server will tell us the correct value when we connect. This IP number is referred to as HISADDR by ppp. The netmask you should use. If your ISP has not provided you with one, you can safely use 255.255.255.0. If your ISP provides you with a static IP address and hostname, you can enter it. Otherwise, we simply let the peer assign whatever IP address it sees fit. If you do not have any of the required information, contact your ISP and make sure they provide it to you. Preparing the Kernel As previously mentioned, ppp uses the tun device, and whichever kernel you are using must have tun configured. The tun device is preconfigured for the default GENERIC kernel that ships with FreeBSD. However, if you have installed a custom kernel, you must make sure your kernel is configured for ppp. To check, go to your kernel compile directory (/sys/i386/conf or /sys/pc98/conf) and examine your configuration file. It should have the following line somewhere in it: pseudo-device tun 1 If this line is not present, you will need to add it to the configuration file and recompile your kernel. The stock GENERIC kernel has this included, so if you have not installed a custom kernel or do not have a /sys directory, you do not have to change anything. If you do need to recompile your kernel, please refer to the kernel configuration section for more information. You can check how many tunnel devices your current kernel has by typing the following: &prompt.root; ifconfig -a tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 inet 200.10.100.1 --> 203.10.100.24 netmask 0xffffffff tun1: flags=8050<POINTOPOINT,RUNNING,MULTICAST> mtu 576 tun2: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 inet 203.10.100.1 --> 203.10.100.20 netmask 0xffffffff tun3: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 In FreeBSD 4.0 and later releases, you will only see any tun devices which have already been used. This means you might not see any tun devices. If this is the case, do not worry; the device should be created dynamically when ppp attempts to use it. This case shows four tunnel devices, two of which are currently configured and being used. It should be noted that the RUNNING flag above indicates that the interface has been used at some point—it is not an error if your interface does not show up as RUNNING. If for some reason you have a kernel that does not have the tun device in it and cannot recompile the kernel, all is not lost. You should be able to dynamically load the code. Please refer to the appropriate &man.modload.8; and &man.lkm.4; man pages for further details. Check the <devicename>tun</devicename> device Under normal circumstances, most users will only require one tun device (/dev/tun0). If you have specified more than one on the pseudo-device line for tun in your kernel configuration file, then alter all references to tun0 below to reflect whichever device number you are using (e.g., tun2). The easiest way to make sure that the tun0 device is configured correctly, is to remake the device. This process is quite easy. To remake the device, do the following: &prompt.root; cd /dev &prompt.root; ./MAKEDEV tun0 If you need 16 tunnel devices in your kernel, you will need to create them. This can be done by executing the following commands: &prompt.root; cd /dev &prompt.root; ./MAKEDEV tun15 To confirm that the kernel is configured correctly, issue the follow command and compare the results: &prompt.root; ifconfig tun0 tun0: flags=8050<POINTOPOINT,RUNNING,MULTICAST> mut 1500 The RUNNING flag may not yet be set, in which case you will see: &prompt.root; ifconfig tun0 tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 Remember from earlier that you might not see the device if it has not been used yet, as tun devices are created on demand in FreeBSD 4.0 and later releases. Name Resolution Configuration The resolver is the part of the system that turns IP addresses into hostnames and vice versa. It can be configured to look for maps that describe IP to hostname mappings in one of two places. The first is a file called /etc/hosts. Read &man.hosts.5; for more information. The second is the Internet Domain Name Service (DNS), a distributed data base, the discussion of which is beyond the scope of this document. The resolver is a set of system calls that do the name mappings, but you have to tell them where to find their information. You do this by first editing the file /etc/host.conf. Do not call this file /etc/hosts.conf (note the extra s) as the results can be confusing. Edit <filename>/etc/host.conf</filename> This file should contain the following two lines (in this order): hosts bind These instruct the resolver to first look in the file /etc/hosts, and then to consult the DNS if the name was not found. Edit <filename>/etc/hosts</filename> This file should contain the IP addresses and names of machines on your network. At a bare minimum it should contain entries for the machine which will be running ppp. Assuming that your machine is called foo.bar.com with the IP address 10.0.0.1, /etc/hosts should contain: 127.0.0.1 localhost.bar.com localhost 127.0.0.1 localhost.bar.com. 10.0.0.1 foo.bar.com foo 10.0.0.1 foo.bar.com. The first two lines define the alias localhost as a synonym for the current machine. Regardless of your own IP address, the IP address for this line should always be 127.0.0.1. The second two lines map the name foo.bar.com (and the shorthand foo) to the IP address 10.0.0.1. If your provider allocates you a static IP address and name, use them in place of the 10.0.0.1 entry. Edit <filename>/etc/resolv.conf</filename> The /etc/resolv.conf file tells the resolver how to behave. If you are running your own DNS, you may leave this file empty. Normally, you will need to enter the following line(s): domain bar.com nameserver x.x.x.x nameserver y.y.y.y The x.x.x.x and y.y.y.y addresses are those given to you by your ISP. Add as many nameserver lines as your ISP provides. The domain line defaults to your hostname's domain, and is probably unnecessary. Refer to the &man.resolv.conf.5; manual page for details of other possible entries in this file. If you are running PPP version 2 or greater, the enable dns command will tell PPP to request that your ISP confirms the nameserver values. If your ISP supplies different addresses (or if there are no nameserver lines in /etc/resolv.conf), PPP will rewrite the file with the ISP-supplied values. <application>PPP</application> Configuration Both ppp and pppd (the kernel level implementation of PPP) use the configuration files located in the /usr/share/examples/ppp directory. The sample configuration files provided are a good reference, so do not delete them. Configuring ppp requires that you edit a number of files, depending on your requirements. What you put in them depends to some extent on whether your ISP allocates IP addresses statically (i.e., you get given one IP address, and always use that one) or dynamically (i.e., your IP address changes each time you connect to your ISP). PPP and Static IP Addresses You will need to create a configuration file called /etc/ppp/ppp.conf. It should look similar to the example below. Lines that end in a : start in the first column, all other lines should be indented as shown using spaces or tabs. 1 default: 2 set device /dev/cuaa0 3 set speed 115200 4 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \"\" ATE1Q0 OK-AT-OK \\dATDT\\TTIMEOUT 40 CONNECT" 5 provider: 6 set phone "(123) 456 7890" 7 set login "TIMEOUT 10 \"\" \"\" gin:--gin: foo word: bar col: ppp" 8 set timeout 300 9 set ifaddr x.x.x.x y.y.y.y 255.255.255.0 0.0.0.0 10 add default HISADDR 11 enable dns Do not include the line numbers, they are just for reference in this discussion. Line 1: Identifies the default entry. Commands in this entry are executed automatically when ppp is run. Line 2: Identifies the device to which the modem is connected. COM1 is /dev/cuaa0 and COM2 is /dev/cuaa1. Line 3: Sets the speed you want to connect at. If 115200 does not work (it should with any reasonably new modem), try 38400 instead. Line 4: The dial string. User PPP uses an expect-send syntax similar to the &man.chat.8; program. Refer to the manual page for information on the features of this language. Line 5: Identifies an entry for a provider called provider. Line 6: Sets the phone number for this provider. Multiple phone numbers may be specified using the colon (:) or pipe character (|)as a separator. The difference between the two separators is described in &man.ppp.8;. To summarize, if you want to rotate through the numbers, use a colon. If you want to always attempt to dial the first number first and only use the other numbers if the first number fails, use the pipe character. Always quote the entire set of phone numbers as shown. Line 7: The login string is of the same chat-like syntax as the dial string. In this example, the string works for a service whose login session looks like this: J. Random Provider login: foo password: bar protocol: ppp You will need to alter this script to suit your own needs. When you write this script for the first time, you should enable chat logging to ensure that the conversation is going as expected. If you are using PAP or CHAP, there will be no login at this point, so your login string can be left blank. See PAP and CHAP authentication for further details. Line 8: Sets the default timeout (in seconds) for the connection. Here, the connection will be closed automatically after 300 seconds of inactivity. If you never want to timeout, set this value to zero. Line 9: Sets the interface addresses. The string x.x.x.x should be replaced by the IP address that your provider has allocated to you. The string y.y.y.y should be replaced by the IP address that your ISP indicated for their gateway (the machine to which you connect). If your ISP hasn't given you a gateway address, use 10.0.0.2/0. If you need to use a guessed address, make sure that you create an entry in /etc/ppp/ppp.linkup as per the instructions for PPP and Dynamic IP addresses. If this line is omitted, ppp cannot run in or mode. Line 10: Adds a default route to your ISP's gateway. The special word HISADDR is replaced with the gateway address specified on line 9. It is important that this line appears after line 9, otherwise HISADDR will not yet be initialized. Line 11: This line tells PPP to ask your ISP to confirm that your nameserver addresses are correct. If your ISP supports this facility, PPP can then update /etc/resolv.conf with the correct nameserver entries. It is not necessary to add an entry to ppp.linkup when you have a static IP address as your routing table entries are already correct before you connect. You may however wish to create an entry to invoke programs after connection. This is explained later with the sendmail example. Example configuration files can be found in the /usr/share/examples/ppp directory. PPP and Dynamic IP Addresses If your service provider does not assign static IP addresses, ppp can be configured to negotiate the local and remote addresses. This is done by guessing an IP address and allowing ppp to set it up correctly using the IP Configuration Protocol (IPCP) after connecting. The ppp.conf configuration is the same as PPP and Static IP Addresses, with the following change: 9 set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 Again, do not include the line numbers, they are just for reference. Indentation of at least one space is required. Line 9: The number after the / character is the number of bits of the address that ppp will insist on. You may wish to use IP numbers more appropriate to your circumstances, but the above example will always work. The last argument (0.0.0.0) tells PPP to negotiate using address 0.0.0.0 rather than 10.0.0.1. Do not use 0.0.0.0 as the first argument to set ifaddr as it prevents PPP from setting up an initial route in mode. If you are running version 1.x of PPP, you will also need to create an entry in /etc/ppp/ppp.linkup. ppp.linkup is used after a connection has been established. At this point, ppp will know what IP addresses should really be used. The following entry will delete the existing bogus routes, and create correct ones: 1 provider: 2 delete ALL 3 add 0 0 HISADDR Line 1: On establishing a connection, ppp will look for an entry in ppp.linkup according to the following rules: First, try to match the same label as we used in ppp.conf. If that fails, look for an entry for the IP address of our gateway. This entry is a four-octet IP style label. If we still have not found an entry, look for the MYADDR entry. Line 2: This line tells ppp to delete all of the existing routes for the acquired tun interface (except the direct route entry). Line 3: This line tells ppp to add a default route that points to HISADDR. HISADDR will be replaced with the IP number of the gateway as negotiated in the IPCP. See the pmdemand entry in the files /usr/share/examples/ppp/ppp.conf.sample and /usr/share/examples/ppp/ppp.linkup.sample for a detailed example. Version 2 of PPP introduces sticky routes. Any add or delete lines that contain MYADDR or HISADDR will be remembered, and any time the actual values of MYADDR or HISADDR change, the routes will be reapplied. This removes the necessity of repeating these lines in ppp.linkup. Receiving Incoming Calls When you configure ppp to receive incoming calls on a machine connected to a LAN, you must decide if you wish to forward packets to the LAN. If you do, you should allocate the peer an IP number from your LAN's subnet, and use the command enable proxy in your /etc/ppp/ppp.conf file. You should also confirm that the /etc/rc.conf file contains the following: gateway="YES" Which getty? Configuring FreeBSD for Dial-up Services provides a good description on enabling dial-up services using getty. An alternative to getty is mgetty, a smarter version of getty designed with dial-up lines in mind. The advantages of using mgetty is that it actively talks to modems, meaning if port is turned off in /etc/ttys then your modem will not answer the phone. Later versions of mgetty (from 0.99beta onwards) also support the automatic detection of PPP streams, allowing your clients script-less access to your server. Refer to Mgetty and AutoPPP for more information on mgetty. <application>PPP</application> Permissions The ppp command must normally be run as user id 0. If however, you wish to allow ppp to run in server mode as a normal user by executing ppp as described below, that user must be given permission to run ppp by adding them to the network group in /etc/group. You will also need to give them access to one or more sections of the configuration file using the allow command: allow users fred mary If this command is used in the default section, it gives the specified users access to everything. PPP Shells for Dynamic-IP Users Create a file called /etc/ppp/ppp-shell containing the following: #!/bin/sh IDENT=`echo $0 | sed -e 's/^.*-\(.*\)$/\1/'` CALLEDAS="$IDENT" TTY=`tty` if [ x$IDENT = xdialup ]; then IDENT=`basename $TTY` fi echo "PPP for $CALLEDAS on $TTY" echo "Starting PPP for $IDENT" exec /usr/sbin/ppp -direct $IDENT This script should be executable. Now make a symbolic link called ppp-dialup to this script using the following commands: &prompt.root; ln -s ppp-shell /etc/ppp/ppp-dialup You should use this script as the shell for all of your dialup users. This is an example from /etc/password for a dialup PPP user with username pchilds (remember don't directly edit the password file, use vipw). pchilds:*:1011:300:Peter Childs PPP:/home/ppp:/etc/ppp/ppp-dialup Create a /home/ppp directory that is world readable containing the following 0 byte files: -r--r--r-- 1 root wheel 0 May 27 02:23 .hushlogin -r--r--r-- 1 root wheel 0 May 27 02:22 .rhosts which prevents /etc/motd from being displayed. PPP shells for Static-IP Users Create the ppp-shell file as above and for each account with statically assigned IPs create a symbolic link to ppp-shell. For example, if you have three dialup customers fred, sam, and mary, that you route class C networks for, you would type the following: &prompt.root; ln -s /etc/ppp/ppp-shell /etc/ppp/ppp-fred &prompt.root; ln -s /etc/ppp/ppp-shell /etc/ppp/ppp-sam &prompt.root; ln -s /etc/ppp/ppp-shell /etc/ppp/ppp-mary Each of these users dialup accounts should have their shell set to the symbolic link created above (i.e., mary's shell should be /etc/ppp/ppp-mary). Setting up ppp.conf for dynamic-IP users The /etc/ppp/ppp.conf file should contain something along the lines of: default: set debug phase lcp chat set timeout 0 ttyd0: set ifaddr 203.14.100.1 203.14.100.20 255.255.255.255 enable proxy ttyd1: set ifaddr 203.14.100.1 203.14.100.21 255.255.255.255 enable proxy The indenting is important. The default: section is loaded for each session. For each dialup line enabled in /etc/ttys create an entry similar to the one for ttyd0: above. Each line should get a unique IP address from your pool of IP addresses for dynamic users. Setting up <filename>ppp.conf</filename> for static-IP users Along with the contents of the sample /usr/share/examples/ppp/ppp.conf above you should add a section for each of the statically assigned dialup users. We will continue with our fred, sam, and mary example. fred: set ifaddr 203.14.100.1 203.14.101.1 255.255.255.255 sam: set ifaddr 203.14.100.1 203.14.102.1 255.255.255.255 mary: set ifaddr 203.14.100.1 203.14.103.1 255.255.255.255 The file /etc/ppp/ppp.linkup should also contain routing information for each static IP user if required. The line below would add a route for the 203.14.101.0 class C via the client's ppp link. fred: add 203.14.101.0 netmask 255.255.255.0 HISADDR sam: add 203.14.102.0 netmask 255.255.255.0 HISADDR mary: add 203.14.103.0 netmask 255.255.255.0 HISADDR More on <command>mgetty</command>, AutoPPP, and MS extensions <command>mgetty</command> and AutoPPP Configuring and compiling mgetty with the AUTO_PPP option enabled allows mgetty to detect the LCP phase of PPP connections and automatically spawn off a ppp shell. However, since the default login/password sequence does not occur it is necessary to authenticate users using either PAP or CHAP. This section assumes the user has successfully configured, compiled, and installed a version of mgetty with the AUTO_PPP option (v0.99beta or later). Make sure your /usr/local/etc/mgetty+sendfax/login.config file has the following in it: /AutoPPP/ - - /etc/ppp/ppp-pap-dialup This will tell mgetty to run the ppp-pap-dialup script for detected PPP connections. Create a file called /etc/ppp/ppp-pap-dialup containing the following (the file should be executable): #!/bin/sh exec /usr/sbin/ppp -direct pap$IDENT For each dialup line enabled in /etc/ttys, create a corresponding entry in /etc/ppp/ppp.conf. This will happily co-exist with the definitions we created above. pap: enable pap set ifaddr 203.14.100.1 203.14.100.20-203.14.100.40 enable proxy Each user logging in with this method will need to have a username/password in /etc/ppp/ppp.secret file, or alternatively add the following option to authenticate users via PAP from /etc/password file. enable passwdauth If you wish to assign some users a static IP number, you can specify the number as the third argument in /etc/ppp/ppp.secret. See /usr/share/examples/ppp/ppp.secret.sample for examples. MS extensions It is possible to configure PPP to supply DNS and NetBIOS nameserver addresses on demand. To enable these extensions with PPP version 1.x, the following lines might be added to the relevant section of /etc/ppp/ppp.conf. enable msext set ns 203.14.100.1 203.14.100.2 set nbns 203.14.100.5 And for PPP version 2 and above: accept dns set dns 203.14.100.1 203.14.100.2 set nbns 203.14.100.5 This will tell the clients the primary and secondary name server addresses, and a netbios nameserver host. In version 2 and above, if the set dns line is omitted, PPP will use the values found in /etc/resolv.conf. PAP and CHAP authentication Some ISPs set their system up so that the authentication part of your connection is done using either of the PAP or CHAP authentication mechanisms. If this is the case, your ISP will not give a login: prompt when you connect, but will start talking PPP immediately. PAP is less secure than CHAP, but security is not normally an issue here as passwords, although being sent as plain text with PAP, are being transmitted down a serial line only. There's not much room for crackers to eavesdrop. Referring back to the PPP and Static IP addresses or PPP and Dynamic IP addresses sections, the following alterations must be made: 7 set login … 12 set authname MyUserName 13 set authkey MyPassword As always, do not include the line numbers, they are just for reference in this discussion. Indentation of at least one space is required. Line 7: Your ISP will not normally require that you log into the server if you're using PAP or CHAP. You must therefore disable your set login string. Line 12: This line specifies your PAP/CHAP user name. You will need to insert the correct value for MyUserName. Line 13: This line specifies your PAP/CHAP password. You will need to insert the correct value for MyPassword. You may want to add an additional line, such as: 15 accept PAP or 15 accept CHAP to make it obvious that this is the intention, but PAP and CHAP are both accepted by default. Changing your <command>ppp</command> configuration on the fly It is possible to talk to the ppp program while it is running in the background, but only if a suitable diagnostic port has been set up. To do this, add the following line to your configuration: set server /var/run/ppp-tun%d DiagnosticPassword 0177 This will tell PPP to listen to the specified unix-domain socket, asking clients for the specified password before allowing access. The %d in the name is replaced with the tun device number that is in use. Once a socket has been set up, the &man.pppctl.8; program may be used in scripts that wish to manipulate the running program. Final system configuration You now have ppp configured, but there are a few more things to do before it is ready to work. They all involve editing the /etc/rc.conf file. Working from the top down in this file, make sure the hostname= line is set, e.g.: hostname="foo.bar.com" If your ISP has supplied you with a static IP address and name, it's probably best that you use this name as your host name. Look for the network_interfaces variable. If you want to configure your system to dial your ISP on demand, make sure the tun0 device is added to the list, otherwise remove it. network_interfaces="lo0 tun0" ifconfig_tun0= The ifconfig_tun0 variable should be empty, and a file called /etc/start_if.tun0 should be created. This file should contain the line: ppp -auto mysystem This script is executed at network configuration time, starting your ppp daemon in automatic mode. If you have a LAN for which this machine is a gateway, you may also wish to use the switch. Refer to the manual page for further details. Set the router program to NO with following line in your /etc/rc.conf: router_enable="NO" It is important that the routed daemon is not started (it is started by default), as it routed tends to delete the default routing table entries created by ppp. It is probably worth your while ensuring that the sendmail_flags line does not include the option, otherwise sendmail will attempt to do a network lookup every now and then, possibly causing your machine to dial out. You may try: sendmail_flags="-bd" The downside of this is that you must force sendmail to re-examine the mail queue whenever the ppp link is up by typing: &prompt.root; /usr/sbin/sendmail -q You may wish to use the !bg command in ppp.linkup to do this automatically: 1 provider: 2 delete ALL 3 add 0 0 HISADDR 4 !bg sendmail -bd -q30m If you don't like this, it is possible to set up a dfilter to block SMTP traffic. Refer to the sample files for further details. Now the only thing left to do is reboot the machine. All that is left is to reboot the machine. After rebooting, you can now either type: &prompt.root; ppp and then dial provider to start the PPP session, or, if you want ppp to establish sessions automatically when there is outbound traffic (and you have not created the start_if.tun0 script), type: &prompt.root; ppp -auto provider Summary To recap, the following steps are necessary when setting up ppp for the first time: Client side: Ensure that the tun device is built into your kernel. Ensure that the tunX device file is available in the /dev directory. Create an entry in /etc/ppp/ppp.conf. The pmdemand example should suffice for most ISPs. If you have a dynamic IP address, create an entry in /etc/ppp/ppp.linkup. Update your /etc/rc.conf file. Create a start_if.tun0 script if you require demand dialing. Server side: Ensure that the tun device is built into your kernel. Ensure that the tunX device file is available in the /dev directory. Create an entry in /etc/passwd (using the &man.vipw.8; program). Create a profile in this users home directory that runs ppp -direct direct-server or similar. Create an entry in /etc/ppp/ppp.conf. The direct-server example should suffice. Create an entry in /etc/ppp/ppp.linkup. Update your /etc/rc.conf file. Using Kernel PPP Parts originally contributed by &a.gena; and &a.rhuff;. Setting up Kernel PPP Before you start setting up PPP on your machine make sure that pppd is located in /usr/sbin and the directory /etc/ppp exists. pppd can work in two modes: As a client, i.e., you want to connect your machine to the outside world via a PPP serial connection or modem line. as a server, i.e. your machine is located on the network and used to connect other computers using PPP. In both cases you will need to set up an options file (/etc/ppp/options or ~/.ppprc if you have more than one user on your machine that uses PPP). You also will need some modem/serial software (preferably kermit) so you can dial and establish a connection with the remote host. Using <command>pppd</command> as a client The following /etc/ppp/options might be used to connect to a CISCO terminal server PPP line. crtscts # enable hardware flow control modem # modem control line noipdefault # remote PPP server must supply your IP address. # if the remote host doesn't send your IP during IPCP # negotiation , remove this option passive # wait for LCP packets domain ppp.foo.com # put your domain name here :<remote_ip> # put the IP of remote PPP host here # it will be used to route packets via PPP link # if you didn't specified the noipdefault option # change this line to <local_ip>:<remote_ip> defaultroute # put this if you want that PPP server will be your # default router To connect: Dial to the remote host using kermit (or some other modem program), and enter your user name and password (or whatever is needed to enable PPP on the remote host). Exit kermit (without hanging up the line). Enter the following: &prompt.root; /usr/src/usr.sbin/pppd.new/pppd /dev/tty01 19200 Be sure to use the appropriate speed and device name. Now your computer is connected with PPP. If the connection fails, you can add the option to the /etc/ppp/options file and check messages on the console to track the problem. Following /etc/ppp/pppup script will make all 3 stages automatically: #!/bin/sh ps ax |grep pppd |grep -v grep pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing pppd, PID=' ${pid} kill ${pid} fi ps ax |grep kermit |grep -v grep pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing kermit, PID=' ${pid} kill -9 ${pid} fi ifconfig ppp0 down ifconfig ppp0 delete kermit -y /etc/ppp/kermit.dial pppd /dev/tty01 19200 /etc/ppp/kermit.dial is a kermit script that dials and makes all necessary authorization on the remote host (an example of such a script is attached to the end of this document). Use the following /etc/ppp/pppdown script to disconnect the PPP line: #!/bin/sh pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'` if [ X${pid} != "X" ] ; then echo 'killing pppd, PID=' ${pid} kill -TERM ${pid} fi ps ax |grep kermit |grep -v grep pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing kermit, PID=' ${pid} kill -9 ${pid} fi /sbin/ifconfig ppp0 down /sbin/ifconfig ppp0 delete kermit -y /etc/ppp/kermit.hup /etc/ppp/ppptest Check to see if PPP is still running by executing /usr/etc/ppp/ppptest, which should look like this: #!/bin/sh pid=`ps ax| grep pppd |grep -v grep|awk '{print $1;}'` if [ X${pid} != "X" ] ; then echo 'pppd running: PID=' ${pid-NONE} else echo 'No pppd running.' fi set -x netstat -n -I ppp0 ifconfig ppp0 To hang up the modem, execute /etc/ppp/kermit.hup, which should contain: set line /dev/tty01 ; put your modem device here set speed 19200 set file type binary set file names literal set win 8 set rec pack 1024 set send pack 1024 set block 3 set term bytesize 8 set command bytesize 8 set flow none pau 1 out +++ inp 5 OK out ATH0\13 echo \13 exit Here is an alternate method using chat instead of kermit. The following two files are sufficient to accomplish a pppd connection. /etc/ppp/options: /dev/cuaa1 115200 crtscts # enable hardware flow control modem # modem control line connect "/usr/bin/chat -f /etc/ppp/login.chat.script" noipdefault # remote PPP serve must supply your IP address. # if the remote host doesn't send your IP during # IPCP negotiation, remove this option passive # wait for LCP packets domain <your.domain> # put your domain name here : # put the IP of remote PPP host here # it will be used to route packets via PPP link # if you didn't specified the noipdefault option # change this line to <local_ip>:<remote_ip> defaultroute # put this if you want that PPP server will be # your default router /etc/ppp/login.chat.script: The following should go on a single line. ABORT BUSY ABORT 'NO CARRIER' "" AT OK ATDT<phone.number> CONNECT "" TIMEOUT 10 ogin:-\\r-ogin: <login-id> TIMEOUT 5 sword: <password> Once these are installed and modified correctly, all you need to do is run pppd, like so: &prompt.root; pppd This sample is based primarily on information provided by: Trev Roydhouse <Trev.Roydhouse@f401.n711.z3.fidonet.org> and used with permission. Using <command>pppd</command> as a server /etc/ppp/options should contain something similar to the following: crtscts # Hardware flow control netmask 255.255.255.0 # netmask ( not required ) 192.114.208.20:192.114.208.165 # ip's of local and remote hosts # local ip must be different from one # you assigned to the ethernet ( or other ) # interface on your machine. # remote IP is ip address that will be # assigned to the remote machine domain ppp.foo.com # your domain passive # wait for LCP modem # modem line The following /etc/ppp/pppserv script will enable tell pppd to behave as a server: #!/bin/sh ps ax |grep pppd |grep -v grep pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing pppd, PID=' ${pid} kill ${pid} fi ps ax |grep kermit |grep -v grep pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing kermit, PID=' ${pid} kill -9 ${pid} fi # reset ppp interface ifconfig ppp0 down ifconfig ppp0 delete # enable autoanswer mode kermit -y /etc/ppp/kermit.ans # run ppp pppd /dev/tty01 19200 Use this /etc/ppp/pppservdown script to stop the server: #!/bin/sh ps ax |grep pppd |grep -v grep pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing pppd, PID=' ${pid} kill ${pid} fi ps ax |grep kermit |grep -v grep pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'` if [ "X${pid}" != "X" ] ; then echo 'killing kermit, PID=' ${pid} kill -9 ${pid} fi ifconfig ppp0 down ifconfig ppp0 delete kermit -y /etc/ppp/kermit.noans The following kermit script (/etc/ppp/kermit.ans) will enable/disable autoanswer mode on your modem. It should look like this: set line /dev/tty01 set speed 19200 set file type binary set file names literal set win 8 set rec pack 1024 set send pack 1024 set block 3 set term bytesize 8 set command bytesize 8 set flow none pau 1 out +++ inp 5 OK out ATH0\13 inp 5 OK echo \13 out ATS0=1\13 ; change this to out ATS0=0\13 if you want to disable ; autoanswer mod inp 5 OK echo \13 exit A script named /etc/ppp/kermit.dial is used for dialing and authenticating on the remote host. You will need to customize it for your needs. Put your login and password in this script; you will also need to change the input statement depending on responses from your modem and remote host. ; ; put the com line attached to the modem here: ; set line /dev/tty01 ; ; put the modem speed here: ; set speed 19200 set file type binary ; full 8 bit file xfer set file names literal set win 8 set rec pack 1024 set send pack 1024 set block 3 set term bytesize 8 set command bytesize 8 set flow none set modem hayes set dial hangup off set carrier auto ; Then SET CARRIER if necessary, set dial display on ; Then SET DIAL if necessary, set input echo on set input timeout proceed set input case ignore def \%x 0 ; login prompt counter goto slhup :slcmd ; put the modem in command mode echo Put the modem in command mode. clear ; Clear unread characters from input buffer pause 1 output +++ ; hayes escape sequence input 1 OK\13\10 ; wait for OK if success goto slhup output \13 pause 1 output at\13 input 1 OK\13\10 if fail goto slcmd ; if modem doesn't answer OK, try again :slhup ; hang up the phone clear ; Clear unread characters from input buffer pause 1 echo Hanging up the phone. output ath0\13 ; hayes command for on hook input 2 OK\13\10 if fail goto slcmd ; if no OK answer, put modem in command mode :sldial ; dial the number pause 1 echo Dialing. output atdt9,550311\13\10 ; put phone number here assign \%x 0 ; zero the time counter :look clear ; Clear unread characters from input buffer increment \%x ; Count the seconds input 1 {CONNECT } if success goto sllogin reinput 1 {NO CARRIER\13\10} if success goto sldial reinput 1 {NO DIALTONE\13\10} if success goto slnodial reinput 1 {\255} if success goto slhup reinput 1 {\127} if success goto slhup if < \%x 60 goto look else goto slhup :sllogin ; login assign \%x 0 ; zero the time counter pause 1 echo Looking for login prompt. :slloop increment \%x ; Count the seconds clear ; Clear unread characters from input buffer output \13 ; ; put your expected login prompt here: ; input 1 {Username: } if success goto sluid reinput 1 {\255} if success goto slhup reinput 1 {\127} if success goto slhup if < \%x 10 goto slloop ; try 10 times to get a login prompt else goto slhup ; hang up and start again if 10 failures :sluid ; ; put your userid here: ; output ppp-login\13 input 1 {Password: } ; ; put your password here: ; output ppp-password\13 input 1 {Entering SLIP mode.} echo quit :slnodial echo \7No dialtone. Check the telephone line!\7 exit 1 ; local variables: ; mode: csh ; comment-start: "; " ; comment-start-skip: "; " ; end: Using <application>PPP</application> over Ethernet (PPPoE) Contributed by &a.jim; (from node.to) 10 Jan 2000. The following describes how to set up PPP over Ethernet, a.k.a, PPPoE. Prerequisites There are a few requirements that your system will need to meet in order for PPPoE to function properly. They are: Kernel source for FreeBSD 3.4 or later ppp from FreeBSD 3.4 or later Kernel Configuration You will need to set the following options in your kernel configuration file and then compile a new kernel. options NETGRAPH Optionally, you can add options NETGRAPH_PPPOE options NETGRAPH_SOCKET although if this functionality is not available at runtime, ppp will load the relevant modules on demand Setting up <filename>ppp.conf</filename> Here is an example of a working ppp.conf: default: # or name_of_service_provider set device PPPoE:xl1 # replace xl1 with your ethernet device set mru 1492 set mtu 1492 set authname YOURLOGINNAME set authkey YOURPASSWORD set log Phase tun command # you can add more detailed logging if you wish set dial set login set ifaddr 10.0.0.1/0 10.0.0.2/0 add default HISADDR nat enable yes # if you want to enable nat for your local net papchap: set authname YOURLOGINNAME set authkey YOURPASSWORD Care should be taken when running PPPoE with the option. Running <application>PPP</application> As root, you can run: &prompt.root; ppp -ddial name_of_service_provider Starting <application>PPP</application> at Boot Add the following to your /etc/rc.conf file: ppp_enable="YES" ppp_mode="ddial" ppp_nat="YES" ppp_profile="default" # or your provider PPPoE with a 3Com HomeConnect ADSL Modem Dual Link Contributed by &a.lioux;, 07 Apr 2001. In short, it does not work. It should, but unfortunately, that is not the case. For whatever reason, this modem does not follow RFC 2516 (A Method for transmitting PPP over Ethernet (PPPoE), written by L. Mamakos, K. Lidl, J. Evarts, D. Carrel, D. Simone, and R. Wheeler). Since it does not follow the specification, FreeBSD's PPPoE implementation will not talk to it. It is very likely that it will not work under other unixes for that same reason. Complain to 3Com if you think it should comply with the PPPoE specification. If you absolutely want to use your ADSL connection with FreeBSD and are stuck with this modem, you can either: Try replacing the modem with a different brand or model if your DSL provider permits you to do so. If you are not sure which brand(s) will work, the &a.questions; is a good place to ask. Try to get it working. Keep in mind that there is no guarantee it will work, your mileage may vary. If you want to try to make it work, you can do the following, but please keep in mind that you do this at your own risk! Just because it worked for me does not mean it will work for you. There are three steps to the process. They are: Make sure you already have ppp.conf set up. See the beginning of this chapter for more details on doing so. Since the modem does not speak the correct protocol, we need to learn how to speak its variant of the protocol. This information was obtained from a DSLreports forum message. The modem speaks 0x3c12 for DISCOVERY, and 0x3c13 for PAYLOAD identifiers instead of 0x8863 and 0x8864 respectively, as mandated by the PPPoE specification. Code RFC's Code Dual Link Modem's Code PAYLOAD 0x8863 0x3c12 PAYLOAD 0x8864 0x3c13 So, now what? You need to recompile the NETGRAPH_PPPOE code with the modem's codes. For this, you should have installed the full kernel sources. Find the /usr/src/sys/netgraph/ng_pppoe.h file. Be careful while editing this file. You have to modify both the little and the big endian entries. For big endian, find the line with 0x8863 in it, and replace the number with 0x3c12. Do the same with 0x8864, replacing it with 0x3c13. For little endian, find the line with 0x6388in it, and replace the number with 0x123c. Do the same with 0x6488, replacing it with 0x133c. Here is a diff of how the new file should look: &prompt.user; diff -u ng_pppoe.h.orig ng_pppoe.h --- ng_pppoe.h.orig Thu Apr 12 13:42:46 2001 +++ ng_pppoe.h Thu Apr 12 13:44:47 2001 @@ -148,8 +148,8 @@ #define PTT_SYS_ERR (0x0202) #define PTT_GEN_ERR (0x0203) -#define ETHERTYPE_PPPOE_DISC 0x8863 /* pppoe discovery packets */ -#define ETHERTYPE_PPPOE_SESS 0x8864 /* pppoe session packets */ +#define ETHERTYPE_PPPOE_DISC 0x3c12 /* pppoe discovery packets */ +#define ETHERTYPE_PPPOE_SESS 0x3c13 /* pppoe session packets */ #else #define PTT_EOL (0x0000) #define PTT_SRV_NAME (0x0101) @@ -162,8 +162,8 @@ #define PTT_SYS_ERR (0x0202) #define PTT_GEN_ERR (0x0302) -#define ETHERTYPE_PPPOE_DISC 0x6388 /* pppoe discovery packets */ -#define ETHERTYPE_PPPOE_SESS 0x6488 /* pppoe session packets */ +#define ETHERTYPE_PPPOE_DISC 0x123c /* pppoe discovery packets */ +#define ETHERTYPE_PPPOE_SESS 0x133c /* pppoe session packets */ #endif struct pppoe_tag { Then do the following as root: &prompt.root; cd /usr/src/sys/modules/netgraph/pppoe &prompt.root; make clean depend all install &prompt.root; make clean Now you can speak the modem's variant of the PPPoE specification. The third step is to figure out the name of the profile your ISP assigned to the modem. The information for this step was obtained from the Roaring Penguin PPPoE program which can be found in the ports collection. If you still are not able to find it, ask your ISP's tech support. If they do not know it either, and you are feeling bold (this may de-program your modem and render it useless, so think twice about doing it). Install the program shipped with the modem by your provider. Then, access the System menu from the program. The name of your profile should be listed there. It is usually ISP. The profile name will be used in the PPPoE configuration inside ppp.conf as the provider parameter. See the &man.ppp.8; manual page for more information. The PPPoE line in your ppp.conf should look like this: set device PPPoE:xl1:ISP Do not forget to change xl1 to the proper device for your ethernet card. Do not forget to change ISP to the profile you have just found above. For additional information, you can try: Cheaper Broadband with FreeBSD on DSL by Renaud Waldura in Daemon News. Another PPPoE tutorial by Sympatico Users Group. Using SLIP Originally contributed by &a.asami; and &a.ghelmer;, with input from &a.wilko; and &a.piero;. Setting up a SLIP Client The following is one way to set up a FreeBSD machine for SLIP on a static host network. For dynamic hostname assignments (i.e., your address changes each time you dial up), you probably need to do something much fancier. First, determine which serial port your modem is connected to. I have a symbolic link to /dev/modem from /dev/cuaa1, and only use the modem name in my configuration files. It can become quite cumbersome when you need to fix a bunch of files in /etc and .kermrc's all over the system! /dev/cuaa0 is COM1, cuaa1 is COM2, etc. Make sure you have the following in your kernel configuration file: pseudo-device sl 1 It is included in the GENERIC kernel, so this should not be a problem unless you have deleted it. Things you have to do only once Add your home machine, the gateway and nameservers to your /etc/hosts file. Mine looks like this: 127.0.0.1 localhost loghost 136.152.64.181 silvia.HIP.Berkeley.EDU silvia.HIP silvia 136.152.64.1 inr-3.Berkeley.EDU inr-3 slip-gateway 128.32.136.9 ns1.Berkeley.edu ns1 128.32.136.12 ns2.Berkeley.edu ns2 Make sure you have before in your /etc/host.conf. Otherwise, funny things may happen. Edit the /etc/rc.conf file. Set your hostname by editing the line that says: hostname=myname.my.domain You should give it your full Internet hostname. Add sl0 to the list of network interfaces by changing the line that says: network_interfaces="lo0" to: network_interfaces=lo0 sl0 Set the startup flags of sl0 by adding a line: ifconfig_sl0="inet ${hostname} slip-gateway netmask 0xffffff00 up" Designate the default router by changing the line: defaultrouter=NO to: defaultrouter=slip-gateway Make a file /etc/resolv.conf which contains: domain HIP.Berkeley.EDU nameserver 128.32.136.9 nameserver 128.32.136.12 As you can see, these set up the nameserver hosts. Of course, the actual domain names and addresses depend on your environment. Set the password for root and toor (and any other accounts that do not have a password). Use passwd or &man.vipw.8;, do not edit the /etc/passwd or /etc/master.passwd files! Reboot your machine and make sure it comes up with the correct hostname. Making a SLIP connection Dial up, type slip at the prompt, enter your machine name and password. The things you need to enter depends on your environment. If you use kermit, you can try a script like this: # kermit setup set modem hayes set line /dev/modem set speed 115200 set parity none set flow rts/cts set terminal bytesize 8 set file type binary # The next macro will dial up and login define slip dial 643-9600, input 10 =>, if failure stop, - output slip\x0d, input 10 Username:, if failure stop, - output silvia\x0d, input 10 Password:, if failure stop, - output ***\x0d, echo \x0aCONNECTED\x0a Of course, you have to change the hostname and password to fit yours. After doing so, you can just type slip from the kermit prompt to get connected. Leaving your password in plain text anywhere in the filesystem is generally a BAD idea. Do it at your own risk. Leave the kermit there (you can suspend it by z) and as root, type: &prompt.root; slattach -h -c -s 115200 /dev/modem If you are able to ping hosts on the other side of the router, you are connected! If it does not work, you might want to try instead of as an argument to slattach. How to shutdown the connection Do the following: &prompt.root; kill -INT `cat /var/run/slattach.modem.pid` to kill slattach. Keep in mind you must be root to do the above. Then go back to kermit (fg if you suspended it) and exit from it (q). The slattach man page says you have to use ifconfig sl0 down to mark the interface down, but this does not seem to make any difference for me. (ifconfig sl0 reports the same thing.) Some times, your modem might refuse to drop the carrier (mine often does). In that case, simply start kermit and quit it again. It usually goes out on the second try. Troubleshooting If it does not work, feel free to ask me. The things that people tripped over so far: Not using or in slattach (I have no idea why this can be fatal, but adding this flag solved the problem for at least one person). Using instead of (might be hard to see the difference on some fonts). Try ifconfig sl0 to see your interface status. For example, you might get: &prompt.root; ifconfig sl0 sl0: flags=10<POINTOPOINT> inet 136.152.64.181 --> 136.152.64.1 netmask ffffff00 Also, netstat -r will give the routing table, in case you get the no route to host messages from ping. Mine looks like: &prompt.root; netstat -r Routing tables Destination Gateway Flags Refs Use IfaceMTU Rtt Netmasks: (root node) (root node) Route Tree for Protocol Family inet: (root node) => default inr-3.Berkeley.EDU UG 8 224515 sl0 - - localhost.Berkel localhost.Berkeley UH 5 42127 lo0 - 0.438 inr-3.Berkeley.E silvia.HIP.Berkele UH 1 0 sl0 - - silvia.HIP.Berke localhost.Berkeley UGH 34 47641234 lo0 - 0.438 (root node) This is after transferring a bunch of files, your numbers should be smaller). Setting up a SLIP Server This document provides suggestions for setting up SLIP Server services on a FreeBSD system, which typically means configuring your system to automatically startup connections upon login for remote SLIP clients. The author has written this document based on his experience; however, as your system and needs may be different, this document may not answer all of your questions, and the author cannot be responsible if you damage your system or lose data due to attempting to follow the suggestions here. Prerequisites This document is very technical in nature, so background knowledge is required. It is assumed that you are familiar with the TCP/IP network protocol, and in particular, network and node addressing, network address masks, subnetting, routing, and routing protocols, such as RIP. Configuring SLIP services on a dial-up server requires a knowledge of these concepts, and if you are not familiar with them, please read a copy of either Craig Hunt's TCP/IP Network Administration published by O'Reilly & Associates, Inc. (ISBN Number 0-937175-82-X), or Douglas Comer's books on the TCP/IP protocol. It is further assumed that you have already setup your modem(s) and configured the appropriate system files to allow logins through your modems. If you have not prepared your system for this yet, please see the tutorial for configuring dialup services; if you have a World-Wide Web browser available, browse the list of tutorials at http://www.FreeBSD.org/. You may also want to check the manual pages for &man.sio.4; for information on the serial port device driver and &man.ttys.5;, &man.gettytab.5;, &man.getty.8;, & &man.init.8; for information relevant to configuring the system to accept logins on modems, and perhaps &man.stty.1; for information on setting serial port parameters (such as clocal for directly-connected serial interfaces). Quick Overview In its typical configuration, using FreeBSD as a SLIP server works as follows: a SLIP user dials up your FreeBSD SLIP Server system and logs in with a special SLIP login ID that uses /usr/sbin/sliplogin as the special user's shell. The sliplogin program browses the file /etc/sliphome/slip.hosts to find a matching line for the special user, and if it finds a match, connects the serial line to an available SLIP interface and then runs the shell script /etc/sliphome/slip.login to configure the SLIP interface. An Example of a SLIP Server Login For example, if a SLIP user ID were Shelmerg, Shelmerg's entry in /etc/master.passwd would look something like this (except it would be all on one line): Shelmerg:password:1964:89::0:0:Guy Helmer - SLIP:/usr/users/Shelmerg:/usr/sbin/sliplogin When Shelmerg logs in, sliplogin will search /etc/sliphome/slip.hosts for a line that had a matching user ID; for example, there may be a line in /etc/sliphome/slip.hosts that reads: Shelmerg dc-slip sl-helmer 0xfffffc00 autocomp sliplogin will find that matching line, hook the serial line into the next available SLIP interface, and then execute /etc/sliphome/slip.login like this: /etc/sliphome/slip.login 0 19200 Shelmerg dc-slip sl-helmer 0xfffffc00 autocomp If all goes well, /etc/sliphome/slip.login will issue an ifconfig for the SLIP interface to which sliplogin attached itself (slip interface 0,in the above example, which was the first parameter in the list given to slip.login) to set the local IP address (dc-slip), remote IP address (sl-helmer), network mask for the SLIP interface (0xfffffc00), and any additional flags (autocomp). If something goes wrong, sliplogin usually logs good informational messages via the daemon syslog facility, which usually goes into /var/log/messages (see the manual pages for &man.syslogd.8; and &man.syslog.conf.5; and perhaps check /etc/syslog.conf to see to which files syslogd is logging). OK, enough of the examples — let us dive into setting up the system. Kernel Configuration FreeBSD's default kernels usually come with two SLIP interfaces defined (sl0 and sl1); you can use netstat -i to see whether these interfaces are defined in your kernel. Sample output from netstat -i: Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll ed0 1500 <Link>0.0.c0.2c.5f.4a 291311 0 174209 0 133 ed0 1500 138.247.224 ivory 291311 0 174209 0 133 lo0 65535 <Link> 79 0 79 0 0 lo0 65535 loop localhost 79 0 79 0 0 sl0* 296 <Link> 0 0 0 0 0 sl1* 296 <Link> 0 0 0 0 0 The sl0 and sl1 interfaces shown in netstat -i's output indicate that there are two SLIP interfaces built into the kernel. (The asterisks after the sl0 and sl1 indicate that the interfaces are down.) However, FreeBSD's default kernels do not come configured to forward packets (ie, your FreeBSD machine will not act as a router) due to Internet RFC requirements for Internet hosts (see RFCs 1009 [Requirements for Internet Gateways], 1122 [Requirements for Internet Hosts — Communication Layers], and perhaps 1127 [A Perspective on the Host Requirements RFCs]), so if you want your FreeBSD SLIP Server to act as a router, you will have to edit the /etc/rc.conf file and change the setting of the gateway_enable variable to . You will then need to reboot for the new settings to take effect. You will notice that near the end of the default kernel configuration file (/sys/i386/conf/GENERIC) is a line that reads: pseudo-device sl 2 This is the line that defines the number of SLIP devices available in the kernel; the number at the end of the line is the maximum number of SLIP connections that may be operating simultaneously. Please refer to Configuring the FreeBSD Kernel for help in reconfiguring your kernel. Sliplogin Configuration As mentioned earlier, there are three files in the /etc/sliphome directory that are part of the configuration for /usr/sbin/sliplogin (see &man.sliplogin.8; for the actual manual page for sliplogin): slip.hosts, which defines the SLIP users & their associated IP addresses; slip.login, which usually just configures the SLIP interface; and (optionally) slip.logout, which undoes slip.login's effects when the serial connection is terminated. <filename>slip.hosts</filename> Configuration /etc/sliphome/slip.hosts contains lines which have at least four items, separated by whitespace: SLIP user's login ID Local address (local to the SLIP server) of the SLIP link Remote address of the SLIP link Network mask The local and remote addresses may be host names (resolved to IP addresses by /etc/hosts or by the domain name service, depending on your specifications in /etc/host.conf), and the network mask may be a name that can be resolved by a lookup into /etc/networks. On a sample system, /etc/sliphome/slip.hosts looks like this: # # login local-addr remote-addr mask opt1 opt2 # (normal,compress,noicmp) # Shelmerg dc-slip sl-helmerg 0xfffffc00 autocomp At the end of the line is one or more of the options. — no header compression — compress headers — compress headers if the remote end allows it — disable ICMP packets (so any ping packets will be dropped instead of using up your bandwidth) Note that sliplogin under early releases of FreeBSD 2 ignored the options that FreeBSD 1.x recognized, so the options , , , and had no effect until support was added in FreeBSD 2.2 (unless your slip.login script included code to make use of the flags). Your choice of local and remote addresses for your SLIP links depends on whether you are going to dedicate a TCP/IP subnet or if you are going to use proxy ARP on your SLIP server (it is not true proxy ARP, but that is the terminology used in this document to describe it). If you are not sure which method to select or how to assign IP addresses, please refer to the TCP/IP books referenced in the slips-prereqs section and/or consult your IP network manager. If you are going to use a separate subnet for your SLIP clients, you will need to allocate the subnet number out of your assigned IP network number and assign each of your SLIP client's IP numbers out of that subnet. Then, you will probably either need to configure a static route to the SLIP subnet via your SLIP server on your nearest IP router, or install gated on your FreeBSD SLIP server and configure it to talk the appropriate routing protocols to your other routers to inform them about your SLIP server's route to the SLIP subnet. Otherwise, if you will use the proxy ARP method, you will need to assign your SLIP client's IP addresses out of your SLIP server's Ethernet subnet, and you will also need to adjust your /etc/sliphome/slip.login and /etc/sliphome/slip.logout scripts to use &man.arp.8; to manage the proxy-ARP entries in the SLIP server's ARP table. <filename>slip.login</filename> Configuration The typical /etc/sliphome/slip.login file looks like this: #!/bin/sh - # # @(#)slip.login 5.1 (Berkeley) 7/1/90 # # generic login file for a slip line. sliplogin invokes this with # the parameters: # 1 2 3 4 5 6 7-n # slipunit ttyspeed loginname local-addr remote-addr mask opt-args # /sbin/ifconfig sl$1 inet $4 $5 netmask $6 This slip.login file merely ifconfig's the appropriate SLIP interface with the local and remote addresses and network mask of the SLIP interface. If you have decided to use the proxy ARP method (instead of using a separate subnet for your SLIP clients), your /etc/sliphome/slip.login file will need to look something like this: #!/bin/sh - # # @(#)slip.login 5.1 (Berkeley) 7/1/90 # # generic login file for a slip line. sliplogin invokes this with # the parameters: # 1 2 3 4 5 6 7-n # slipunit ttyspeed loginname local-addr remote-addr mask opt-args # /sbin/ifconfig sl$1 inet $4 $5 netmask $6 # Answer ARP requests for the SLIP client with our Ethernet addr /usr/sbin/arp -s $5 00:11:22:33:44:55 pub The additional line in this slip.login, arp -s $5 00:11:22:33:44:55 pub, creates an ARP entry in the SLIP server's ARP table. This ARP entry causes the SLIP server to respond with the SLIP server's Ethernet MAC address whenever a another IP node on the Ethernet asks to speak to the SLIP client's IP address. When using the example above, be sure to replace the Ethernet MAC address (00:11:22:33:44:55) with the MAC address of your system's Ethernet card, or your proxy ARP will definitely not work! You can discover your SLIP server's Ethernet MAC address by looking at the results of running netstat -i; the second line of the output should look something like: ed0 1500 <Link>0.2.c1.28.5f.4a 191923 0 129457 0 116 This indicates that this particular system's Ethernet MAC address is 00:02:c1:28:5f:4a — the periods in the Ethernet MAC address given by netstat -i must be changed to colons and leading zeros should be added to each single-digit hexadecimal number to convert the address into the form that &man.arp.8; desires; see the manual page on &man.arp.8; for complete information on usage. When you create /etc/sliphome/slip.login and /etc/sliphome/slip.logout, the execute bit (ie, chmod 755 /etc/sliphome/slip.login /etc/sliphome/slip.logout) must be set, or sliplogin will be unable to execute it. <filename>slip.logout</filename> Configuration /etc/sliphome/slip.logout is not strictly needed (unless you are implementing proxy ARP), but if you decide to create it, this is an example of a basic slip.logout script: #!/bin/sh - # # slip.logout # # logout file for a slip line. sliplogin invokes this with # the parameters: # 1 2 3 4 5 6 7-n # slipunit ttyspeed loginname local-addr remote-addr mask opt-args # /sbin/ifconfig sl$1 down If you are using proxy ARP, you will want to have /etc/sliphome/slip.logout remove the ARP entry for the SLIP client: #!/bin/sh - # # @(#)slip.logout # # logout file for a slip line. sliplogin invokes this with # the parameters: # 1 2 3 4 5 6 7-n # slipunit ttyspeed loginname local-addr remote-addr mask opt-args # /sbin/ifconfig sl$1 down # Quit answering ARP requests for the SLIP client /usr/sbin/arp -d $5 The arp -d $5 removes the ARP entry that the proxy ARP slip.login added when the SLIP client logged in. It bears repeating: make sure /etc/sliphome/slip.logout has the execute bit set for after you create it (ie, chmod 755 /etc/sliphome/slip.logout). Routing Considerations If you are not using the proxy ARP method for routing packets between your SLIP clients and the rest of your network (and perhaps the Internet), you will probably either have to add static routes to your closest default router(s) to route your SLIP client subnet via your SLIP server, or you will probably need to install and configure gated on your FreeBSD SLIP server so that it will tell your routers via appropriate routing protocols about your SLIP subnet. Static Routes Adding static routes to your nearest default routers can be troublesome (or impossible, if you do not have authority to do so...). If you have a multiple-router network in your organization, some routers, such as Cisco and Proteon, may not only need to be configured with the static route to the SLIP subnet, but also need to be told which static routes to tell other routers about, so some expertise and troubleshooting/tweaking may be necessary to get static-route-based routing to work. Running <command>gated</command> An alternative to the headaches of static routes is to install gated on your FreeBSD SLIP server and configure it to use the appropriate routing protocols (RIP/OSPF/BGP/EGP) to tell other routers about your SLIP subnet. You can use gated from the ports collection or retrieve and build it yourself from the GateD anonymous ftp site; the current version as of this writing is gated-R3_5Alpha_8.tar.Z, which includes support for FreeBSD out-of-the-box. Complete information and documentation on gated is available on the Web starting at the Merit GateD Consortium. Compile and install it, and then write a /etc/gated.conf file to configure your gated; here is a sample, similar to what the author used on a FreeBSD SLIP server: # # gated configuration file for dc.dsu.edu; for gated version 3.5alpha5 # Only broadcast RIP information for xxx.xxx.yy out the ed Ethernet interface # # # tracing options # traceoptions "/var/tmp/gated.output" replace size 100k files 2 general ; rip yes { interface sl noripout noripin ; interface ed ripin ripout version 1 ; traceoptions route ; } ; # # Turn on a bunch of tracing info for the interface to the kernel: kernel { traceoptions remnants request routes info interface ; } ; # # Propagate the route to xxx.xxx.yy out the Ethernet interface via RIP # export proto rip interface ed { proto direct { xxx.xxx.yy mask 255.255.252.0 metric 1; # SLIP connections } ; } ; # # Accept routes from RIP via ed Ethernet interfaces import proto rip interface ed { all ; } ; The above sample gated.conf file broadcasts routing information regarding the SLIP subnet xxx.xxx.yy via RIP onto the Ethernet; if you are using a different Ethernet driver than the ed driver, you will need to change the references to the ed interface appropriately. This sample file also sets up tracing to /var/tmp/gated.output for debugging gated's activity; you can certainly turn off the tracing options if gated works OK for you. You will need to change the xxx.xxx.yy's into the network address of your own SLIP subnet (be sure to change the net mask in the proto direct clause as well). When you get gated built and installed and create a configuration file for it, you will need to run gated in place of routed on your FreeBSD system; change the routed/gated startup parameters in /etc/netstart as appropriate for your system. Please see the manual page for gated for information on gated's command-line parameters. diff --git a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml index 011f36c05a..ebedc1631d 100644 --- a/en_US.ISO8859-1/books/handbook/printing/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/printing/chapter.sgml @@ -1,4565 +1,4565 @@ Printing Contributed by &a.kelly;, 30 September 1995. Restructured and updated by &a.jim;, March 2000. Synopsis 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. Introduction 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. 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. 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 setup 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 Nearly all printers you can get for a PC today support one or both of the following interfaces: Serial interfaces 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. Parallel interfaces use a parallel port on your computer to send data to the printer. Parallel interfaces are common in the PC market. 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. Parallel interfaces are sometimes known as Centronics interfaces, named after the connector type on the printer. In general, serial interfaces are slower than parallel interfaces. Parallel interfaces usually offer just one-way communication (computer to printer) while serial gives you two-way. Many newer parallel ports and printers can communicate in both directions under FreeBSD when a IEEE1284 compliant cable is used. Usually, the only time you need two-way communication with the printer is if the printer speaks PostScript. PostScript printers can be very verbose. In fact, 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/lpt0 to FreeBSD; the second is /dev/lpt1, and so on. 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. 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. 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; dmesg | grep sioN Where N is the number of the serial port, starting from zero. If you see output similar to the following: sio2 at 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; dmesg | grep lptN Where N is the number of the parallel port, starting from zero. If you see output similar to the following lpt0 at 0x378-0x37f on isa 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 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 first parallel port, lpt1 for the second, 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 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 somewhat faster but uses up a precious IRQ line. You should use whichever one works. 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 or add an lpt0 entry. If you are setting up the second parallel port, use lpt1 instead. Use lpt2 for the third port, and so on. If you want interrupt-driven mode, add the irq specifier: device lpt0 at isa? port? tty irq N vector lptintr Where N is the IRQ number for your computer's parallel port. If you want polled mode, do not add the irq specifier: device lpt0 at isa? port? tty vector lptintr 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 -u N to set interrupt-driven mode for lptN. Type: &prompt.root; lptcontrol -p -u N 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. 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. 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 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 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 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: ~$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: ~>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. 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. 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 fs, fc, xs, and xc capabilities; 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 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 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 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, or 38400 bits-per-second. fc#clear-bits Clears the flag bits clear-bits in the sgttyb structure after opening the device. fs#set-bits Sets the flag bits set-bits in the sgttyb structure. xc#clear-bits Clears local mode bits clear-bits after opening the device. xs#set-bits Sets local mode bits set-bits. For more information on the bits for the fc, fs, xc, and xs capabilities, see the file /usr/include/sys/ioctl_compat.h. When LPD opens the device specified by the lp capability, it reads the flag bits in the sgttyb structure; it clears any bits in the fc capability, then sets bits in the fs capability, then applies the resultant setting. It does the same for the local mode bits as well. Let us add to our example printer on the sixth serial port. We will set the bps rate to 38400. For the flag bits, we will set the TANDEM, ANYP, LITOUT, FLUSHO, and PASS8 flags. For the local mode bits, we will set the LITOUT and PASS8 flags: bamboo|ps|PS|S|panasonic|Panasonic KX-P4455 PostScript v51.4:\ :sh:sd=/var/spool/lpd/bamboo:\ :lp=/dev/ttyd5:fs#0x82000c1:xs#0x820: Installing the Text Filter 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:fs#0x82000e1:xs#0x820:\ :if=/usr/local/libexec/if-simple: Turn on LPD &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 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. Even some people (myself included) write PostScript code directly. But 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. 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). 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's 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. 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 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? 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 # read 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 "$first_line"; cat ) | /usr/local/bin/textps && printf "\004" && exit 0 exit 2 fi In the above script, textps is a program we installed separately to convert plain text to PostScript. You can use any text-to-PostScript program you wish. The FreeBSD ports collection (see The Ports Collection) includes a full featured text-to-PostScript program called a2ps that you might want to investigate. Simulating PostScript on Non-PostScript Printers PostScript is the de facto standard for high quality typesetting and printing. PostScript is, however, an expensive standard. Thankfully, Alladin Enterprises has a free PostScript work-alike called Ghostscript that runs with FreeBSD. Ghostscript can read most PostScript files and can render their pages onto a variety of devices, including many brands of non-PostScript printers. By installing Ghostscript and using a special text filter for your printer, you can make your non-PostScript printer act like a real PostScript printer. Ghostscript is in the FreeBSD ports collection, if you would like to install it from there. You can fetch, build, and install it quite easily yourself, as well. To simulate PostScript, we have the text filter detect if it is printing a PostScript file. If it is not, then the filter will pass the file directly to the printer; otherwise, it will use Ghostscript to first convert the file into a format the printer will understand. Here is an example: the following script is a text filter for Hewlett Packard DeskJet 500 printers. For other printers, substitute the argument to the gs (Ghostscript) command. (Type gs -h to get a list of devices the current installation of Ghostscript supports.) #!/bin/sh # # ifhp - Print Ghostscript-simulated PostScript on a DeskJet 500 # Installed in /usr/local/libexec/hpif # # Treat LF as CR+LF: # printf "\033&k2G" || exit 2 # # Read first two characters of the file # read first_line first_two_chars=`expr "$first_line" : '\(..\)'` if [ "$first_two_chars" = "%!" ]; then # # It is PostScript; use Ghostscript to scan-convert and print it. # # Note that PostScript files are actually interpreted programs, # and those programs are allowed to write to stdout, which will # mess up the printed output. So, we redirect stdout to stderr # and then make descriptor 3 go to stdout, and have Ghostscript # write its output there. Exercise for the clever reader: # capture the stderr output from Ghostscript and mail it back to # the user originating the print job. # exec 3>&1 1>&2 /usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=djet500 \ -sOutputFile=/dev/fd/3 - && exit 0 # /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 # 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/hpif: 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? 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 rf 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. 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:fs#0x82000e1:xs#0x820: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. 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. 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. 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, 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 Output Filters 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 Header Page Options 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 should use the user and host arguments to generate a suitable + 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 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 Simple Printer Setup. 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). 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 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's 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:fs#0x82000e1:xs#0x820: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:fs#0x82000e1:xs#0x820: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 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. 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:fs#0x82000e1:xs#0x820: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:fs#0x82000e1:xs#0x820:rw:mx#5000:\ :if=/usr/local/libexec/psif:\ :df=/usr/local/libexec/psdf: The spooling directory is the 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/bam boo/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 compute resources, you can give them token accounts, with no home directory and a useless shell like /usr/bin/false. Accounting for Printer Usage 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. A 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 This section tells you how to use printers you have setup 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 Administrating 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 ... 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 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 files she's 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. 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. Administrating 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 takes 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's 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's started, 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, 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 http://www.astart.com/lprng/LPRng.html. 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 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, OS/2, 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, set the CRMOD bit in fs capability 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. 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 TANDEM bit in the fs capability. If the printer supports carrier flow control, specify the MDMBUF bit in the fs capability. Make sure the cable connecting the printer to the computer is correctly wired for carrier flow control. If the printer does not support any flow control, use some combination of the NLDELAY, TBDELAY, CRDELAY, VTDELAY, and BSDELAY bits in the fs capability to add appropriate delays to the stream of data sent to the printer. 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 bits in the fs and fc capabilities; 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 af2d3d1704..7269fc48af 100644 --- a/en_US.ISO8859-1/books/handbook/security/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/security/chapter.sgml @@ -1,2921 +1,2921 @@ Security Much of this chapter has been taken from the &man.security.7; man page, originally written by &a.dillon;. Synopsis The following chapter will provide a basic introduction to system security concepts, some general good rules of thumb, and some advanced topics such as S/Key, OpenSSL, Kerberos, and others. 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 internetworked, security becomes an ever 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 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. A denial of service attack is an action that deprives the machine of needed resources. Typically, D.O.S. attacks are brute-force mechanisms that attempt to crash or otherwise make a machine unusable by overwhelming its servers or network stack. Some D.O.S. attacks try to take advantages 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. A user account compromise is even more common then a D.O.S. 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 then 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. 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 an 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 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. Backdoors provide 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 – root-run servers and suid/sgid binaries. Securing user accounts. Securing the password file. Securing the kernel core, raw devices, and filesystems. 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 FreeBSD The sections that follow will cover the methods of securing your FreeBSD system that were mentioned in the last section of this chapter. Securing the root account and staff accounts 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 pty's are specified as being unsecure 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. Consider every access method – services such as FTP often fall through the cracks. Direct root logins should only be allowed via the system console. 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 then 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 *'ing out the crypted password for the staff accounts. Using the &man.vipw.8; command, one can replace each instance of a crypted 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 * out the passwords for staff accounts also guarantees that staff members can only login through secure access methods that you have setup. This forces all staff members to use secure, encrypted connections for all of their sessions which closes an important hole used by many intruders: That of 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. 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 effect all the machine the staff member may have an account on. 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 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 isn't perfect unless you go to 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! FreeBSD 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. 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 then 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 hole 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 then 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 crypted password file, potentially compromising any passworded account. Alternatively an intruder who breaks group kmem can monitor keystrokes sent through pty's, including pty'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 * 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 crypted 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 Checking file integrity below). Securing the Kernel Core, Raw Devices, and Filesystems 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 FreeBSD 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 should not have the bpf device compiled in. 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 then 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 limit-access box to ssh to the other machines. Except for its network traffic, NFS is the least visible method – allowing you to monitor the filesystems 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 limit-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 boxes 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 then 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 daemon on the client box may already be compromised. All in all, using ssh may be necessary when running over unsecure links, but it's 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 effect convenience, and can add security features that do effect 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 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 no 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 FreeBSD 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 everything under 4000 off in your firewall (except for certain specific Internet-accessible ports, of course). Another common DOS attack is called a springboard attack – to attack a server in a manner that causes the server to generate responses which then overload 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 FreeBSD kernel has a new kernel compile option called ICMP_BANDLIM 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 then 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 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 unsecure machine, your keys becomes exposed. The actual keys themselves are not exposed, but ssh installs a forwarding port for the duration of your login and if a attacker has broken root on the unsecure 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 exposable 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). 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. DES, MD5, and Crypt Parts rewritten and updated by &a.unfurl;, 21 March 2000. 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 is not such a problem for users that live in the US, but since the source code for DES could not be exported outside the US, FreeBSD had to find a way to both comply with US law and retain compatibility with all the other UNIX variants that still use 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 FreeBSD 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 It is pretty easy to identify which encryption method FreeBSD 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 with encrypted with the DES hash and also begin with the characters $1$. 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 libraries can identify the passwords this way as well. As a result, the DES libraries are able to identify MD5 passwords, and use MD5 to check passwords that were encrypted that way, and DES for the rest. They are able to do this because the DES libraries also contain MD5. Unfortunately, the reverse is not true, so the MD5 libraries cannot authenticate passwords that were encrypted with DES. Identifying which library is being used by the programs on your system is easy as well. Any program that uses crypt is linked against libcrypt which for each type of library is a symbolic link to the appropriate implementation. For example, on a system using the DES versions: &prompt.user; ls -l /usr/lib/libcrypt* lrwxr-xr-x 1 root wheel 13 Mar 19 06:56 libcrypt.a -> libdescrypt.a lrwxr-xr-x 1 root wheel 18 Mar 19 06:56 libcrypt.so.2.0 -> libdescrypt.so.2.0 lrwxr-xr-x 1 root wheel 15 Mar 19 06:56 libcrypt_p.a -> libdescrypt_p.a On a system using the MD5-based libraries, the same links will be present, but the target will be libscrypt rather than libdescrypt. If you have installed the DES-capable crypt library libdescrypt (e.g. by installing the "crypto" distribution), then which password format will be used for new passwords is controlled by the passwd_format login capability in /etc/login.conf, which takes values of either des or md5. See the &man.login.conf.5; manpage for more information about login capabilities. S/Key S/Key is a one-time password scheme based on a one-way hash function. FreeBSD uses the MD4 hash for compatibility but other systems have used MD5 and DES-MAC. S/Key has been part of the FreeBSD 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. There are three different sorts of passwords which we will talk about in the discussion 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 and accepted by the keyinit program 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 program (and sometimes the keyinit program) 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 secret passwords are not limited to 8 characters like UNIX passwords, 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 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. One is what is known as the seed or key and consists of two letters and five digits. The other is what is called the iteration count and is 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 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 login and su programs keep 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 must be reinitialized. There are four programs involved in the S/Key system which we will discuss below. The key program accepts an iteration count, a seed, and a secret password, and generates a one-time password. The keyinit program is used to initialized S/Key, and to change passwords, iteration counts, or seeds; it takes either a secret password, or an iteration count, seed, and one-time password. The keyinfo program examines the /etc/skeykeys file and prints out the invoking user's current iteration count and seed. Finally, the login and su programs contain the necessary logic to accept S/Key one-time passwords for authentication. The login program is also capable of disallowing the use of UNIX passwords on connections coming from specified addresses. There are four different sorts of operations we will cover. The first is using the keyinit program over a secure connection to set up S/Key for the first time, or to change your password or seed. The second operation is using the keyinit program over an insecure connection, in conjunction with the key program over a secure connection, to do the same. The third is using the key program to log in over an insecure connection. The fourth is using the key program 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 At the Enter secret password: prompt 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 S/Key instance; your login name, the iteration count, and seed. When logging in with S/Key, 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 S/Key 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 the key program; 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: 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 Now switch back over to the insecure connection, and copy the one-time password generated by key over to the keyinit program: s/key access password:CURE MIKE BANE HIM RACY GORE ID unfurl s/key is 100 to17759 CURE MIKE BANE HIM RACY GORE The rest of the description from the previous section applies here as well. Generating a single one-time password Once you've initialized S/Key, 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: As a side note, the S/Key prompt has a useful feature (not shown here): if you press return at the password prompt, the login program will turn echo on, so you can see what you are typing. This can be extremely useful if you are attempting to type in an S/Key by hand, such as from a printout. Also, if this machine were configured to disallow UNIX passwords over a connection from the source machine, the prompt would have also included the annotation (s/key required), indicating that only S/Key one-time passwords will be accepted. 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 the key command on. (There are versions of the key program from DOS, Windows and MacOS as well.) The key program needs 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 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 ... This is the easiest mechanism if you have a trusted machine. There is a Java S/Key key applet, The Java OTP Calculator, that you can download and run locally on any Java supporting browser. Generating multiple one-time passwords - Sometimes you have have to go places where you do not have + 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 command to generate a number of one-time passwords before hand 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 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 Restrictions can be placed 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 info 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 FreeBSD default), 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 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 uneducable. 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. Kerberos Contributed by &a.markm; (based on contribution by &a.md;). 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 FreeBSD. However, you should refer to the relevant manual pages for a complete description. In FreeBSD, the Kerberos is not that from the original 4.4BSD-Lite, distribution, but eBones, which had been previously ported to FreeBSD 1.1.5.1, and was sourced from outside the USA/Canada, and was thus available to system owners outside those countries during the era of restrictive export controls on cryptographic code from the USA. 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, of 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 GRONDAR.ZA and the server is grunt.grondar.za. We edit or create the krb.conf file: &prompt.root; cat krb.conf GRONDAR.ZA GRONDAR.ZA grunt.grondar.za 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 hosts name means that host also provides an administrative database server. For further explanation of these terms, please consult the Kerberos man pages. Now we have to add grunt.grondar.za to the GRONDAR.ZA realm and also add an entry to put all hosts in the .grondar.za domain in the GRONDAR.ZA realm. The krb.realms file would be updated as follows: &prompt.root; cat krb.realms grunt.grondar.za GRONDAR.ZA .grondar.za GRONDAR.ZA .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 ]: GRONDAR.ZA 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 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 rcp, rlogin and rsh. Now let's 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 server can pick it up. Use the mv 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's 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 automagically 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: GRONDAR.ZA &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.grondar.za) 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@GRONDAR.ZA Issued Expires Principal Apr 30 11:23:22 Apr 30 19:23:22 krbtgt.GRONDAR.ZA@GRONDAR.ZA Now try changing the password using passwd to check if the kpasswd daemon can get authorization to the Kerberos database: &prompt.user; passwd realm GRONDAR.ZA 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 supassword. We could now add an id which is authorized to su 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.grondar.za) 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@GRONDAR.ZA Now try doing the su: &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@GRONDAR.ZA Issued Expires Principal May 2 20:43:12 May 3 04:43:12 krbtgt.GRONDAR.ZA@GRONDAR.ZA 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 su to root if the necessary entries are in the .klogin file in root's home directory: &prompt.root; cat /root/.klogin jane.root@GRONDAR.ZA Likewise, if a user has in their own home directory lines of the form: &prompt.user; cat ~/.klogin jane@GRONDAR.ZA jack@GRONDAR.ZA This allows anyone in the GRONDAR.ZA realm who has authenticated themselves to jane or jack (via kinit, see above) access to rlogin to jane's account or files on this system (grunt) via rlogin, rsh or rcp. For example, Jane now logs into another system, using Kerberos: &prompt.user; kinit MIT Project Athena (grunt.grondar.za) 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.grondar.za) 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 Firewalls Contributed by &a.gpalmer; and Alex Nash. Firewalls are an area of increasing interest for people who are connected to the Internet, and are even finding applications on private networks to provide enhanced security. This section will hopefully explain what firewalls are, how to use them, and how to use the facilities provided in the FreeBSD kernel to implement them. People often think that having a firewall between your internal network and the Big Bad Internet will solve all your security problems. It may help, but a poorly setup firewall system is more of a security risk than not having one at all. A firewall can add another layer of security to your systems, but it cannot stop a really determined cracker from penetrating your internal network. If you let internal security lapse because you believe your firewall to be impenetrable, you have just made the crackers job that much easier. What is a firewall? There are currently two distinct types of firewalls in common use on the Internet today. The first type is more properly called a packet filtering router, where the kernel on a multi-homed machine chooses whether to forward or block packets based on a set of rules. The second type, known as a proxy server, relies on daemons to provide authentication and to forward packets, possibly on a multi-homed machine which has kernel packet forwarding disabled. Sometimes sites combine the two types of firewalls, so that only a certain machine (known as a bastion host) is allowed to send packets through a packet filtering router onto an internal network. Proxy services are run on the bastion host, which are generally more secure than normal authentication mechanisms. FreeBSD comes with a kernel packet filter (known as IPFW), which is what the rest of this section will concentrate on. Proxy servers can be built on FreeBSD from third party software, but there is such a variety of proxy servers available that it would be impossible to cover them in this document. Packet filtering routers A router is a machine which forwards packets between two or more networks. A packet filtering router has an extra piece of code in its kernel which compares each packet to a list of rules before deciding if it should be forwarded or not. Most modern IP routing software has packet filtering code within it that defaults to forwarding all packets. To enable the filters, you need to define a set of rules for the filtering code so it can decide if the packet should be allowed to pass or not. To decide whether a packet should be passed on, the code looks through its set of rules for a rule which matches the contents of this packets headers. Once a match is found, the rule action is obeyed. The rule action could be to drop the packet, to forward the packet, or even to send an ICMP message back to the originator. Only the first match counts, as the rules are searched in order. Hence, the list of rules can be referred to as a rule chain. The packet matching criteria varies depending on the software used, but typically you can specify rules which depend on the source IP address of the packet, the destination IP address, the source port number, the destination port number (for protocols which support ports), or even the packet type (UDP, TCP, ICMP, etc). Proxy servers Proxy servers are machines which have had the normal system daemons (telnetd, ftpd, etc) replaced with special servers. These servers are called proxy servers as they normally only allow onward connections to be made. This enables you to run (for example) a proxy telnet server on your firewall host, and people can telnet in to your firewall from the outside, go through some authentication mechanism, and then gain access to the internal network (alternatively, proxy servers can be used for signals coming from the internal network and heading out). Proxy servers are normally more secure than normal servers, and often have a wider variety of authentication mechanisms available, including one-shot password systems so that even if someone manages to discover what password you used, they will not be able to use it to gain access to your systems as the password instantly expires. As they do not actually give users access to the host machine, it becomes a lot more difficult for someone to install backdoors around your security system. Proxy servers often have ways of restricting access further, so that only certain hosts can gain access to the servers, and often they can be set up so that you can limit which users can talk to which destination machine. Again, what facilities are available depends largely on what proxy software you choose. What does IPFW allow me to do? IPFW, the software supplied with FreeBSD, is a packet filtering and accounting system which resides in the kernel, and has a user-land control utility, &man.ipfw.8;. Together, they allow you to define and query the rules currently used by the kernel in its routing decisions. There are two related parts to IPFW. The firewall section allows you to perform packet filtering. There is also an IP accounting section which allows you to track usage of your router, based on similar rules to the firewall section. This allows you to see (for example) how much traffic your router is getting from a certain machine, or how much WWW (World Wide Web) traffic it is forwarding. As a result of the way that IPFW is designed, you can use IPFW on non-router machines to perform packet filtering on incoming and outgoing connections. This is a special case of the more general use of IPFW, and the same commands and techniques should be used in this situation. Enabling IPFW on FreeBSD As the main part of the IPFW system lives in the kernel, you will need to add one or more options to your kernel configuration file, depending on what facilities you want, and recompile your kernel. See reconfiguring the kernel for more details on how to recompile your kernel. There are currently three kernel configuration options relevant to IPFW: options IPFIREWALL Compiles into the kernel the code for packet filtering. options IPFIREWALL_VERBOSE Enables code to allow logging of packets through &man.syslogd.8;. Without this option, even if you specify that packets should be logged in the filter rules, nothing will happen. options IPFIREWALL_VERBOSE_LIMIT=10 Limits the number of packets logged through &man.syslogd.8; on a per entry basis. You may wish to use this option in hostile environments in which you want to log firewall activity, but do not want to be open to a denial of service attack via syslog flooding. When a chain entry reaches the packet limit specified, logging is turned off for that particular entry. To resume logging, you will need to reset the associated counter using the &man.ipfw.8; utility: &prompt.root; ipfw zero 4500 Where 4500 is the chain entry you wish to continue logging. Previous versions of FreeBSD contained an IPFIREWALL_ACCT option. This is now obsolete as the firewall code automatically includes accounting facilities. Configuring IPFW The configuration of the IPFW software is done through the &man.ipfw.8; utility. The syntax for this command looks quite complicated, but it is relatively simple once you understand its structure. There are currently four different command categories used by the utility: addition/deletion, listing, flushing, and clearing. Addition/deletion is used to build the rules that control how packets are accepted, rejected, and logged. Listing is used to examine the contents of your rule set (otherwise known as the chain) and packet counters (accounting). Flushing is used to remove all entries from the chain. Clearing is used to zero out one or more accounting entries. Altering the IPFW rules The syntax for this form of the command is: ipfw -N command index action log protocol addresses options There is one valid flag when using this form of the command: -N Resolve addresses and service names in output. The command given can be shortened to the shortest unique form. The valid commands are: add Add an entry to the firewall/accounting rule list delete Delete an entry from the firewall/accounting rule list Previous versions of IPFW used separate firewall and accounting entries. The present version provides packet accounting with each firewall entry. If an index value is supplied, it used to place the entry at a specific point in the chain. Otherwise, the entry is placed at the end of the chain at an index 100 greater than the last chain entry (this does not include the default policy, rule 65535, deny). The log option causes matching rules to be output to the system console if the kernel was compiled with IPFIREWALL_VERBOSE. Valid actions are: reject Drop the packet, and send an ICMP host or port unreachable (as appropriate) packet to the source. allow Pass the packet on as normal. (aliases: pass and accept) deny Drop the packet. The source is not notified via an ICMP message (thus it appears that the packet never arrived at the destination). count Update packet counters but do not allow/deny the packet based on this rule. The search continues with the next chain entry. Each action will be recognized by the shortest unambiguous prefix. The protocols which can be specified are: all Matches any IP packet icmp Matches ICMP packets tcp Matches TCP packets udp Matches UDP packets The address specification is: from address/maskport to address/maskport via interface You can only specify port in conjunction with protocols which support ports (UDP and TCP). The is optional and may specify the IP address or domain name of a local IP interface, or an interface name (e.g. ed0) to match only packets coming through this interface. Interface unit numbers can be specified with an optional wildcard. For example, ppp* would match all kernel PPP interfaces. The syntax used to specify an address/mask is: address or address/mask-bits or address:mask-pattern A valid hostname may be specified in place of the IP address. is a decimal number representing how many bits in the address mask should be set. e.g. specifying 192.216.222.1/24 will create a mask which will allow any address in a class C subnet (in this case, 192.216.222) to be matched. is an IP address which will be logically AND'ed with the address given. The keyword any may be used to specify any IP address. The port numbers to be blocked are specified as: port,port,port… to specify either a single port or a list of ports, or port-port to specify a range of ports. You may also combine a single range with a list, but the range must always be specified first. The options available are: frag Matches if the packet is not the first fragment of the datagram. in Matches if the packet is on the way in. out Matches if the packet is on the way out. ipoptions spec Matches if the IP header contains the comma separated list of options specified in spec. The supported list of IP options are: ssrr (strict source route), lsrr (loose source route), rr (record packet route), and ts (time stamp). The absence of a particular option may be denoted with a leading !. established Matches if the packet is part of an already established TCP connection (i.e. it has the RST or ACK bits set). You can optimize the performance of the firewall by placing established rules early in the chain. setup Matches if the packet is an attempt to establish a TCP connection (the SYN bit set is set but the ACK bit is not). tcpflags flags Matches if the TCP header contains the comma separated list of flags. The supported flags are fin, syn, rst, psh, ack, and urg. The absence of a particular flag may be indicated by a leading !. icmptypes types Matches if the ICMP type is present in the list types. The list may be specified as any combination of ranges and/or individual types separated by commas. Commonly used ICMP types are: 0 echo reply (ping reply), 3 destination unreachable, 5 redirect, 8 echo request (ping request), and 11 time exceeded (used to indicate TTL expiration as with &man.traceroute.8;). Listing the IPFW rules The syntax for this form of the command is: ipfw -a -t -N l There are three valid flags when using this form of the command: -a While listing, show counter values. This option is the only way to see accounting counters. -t Display the last match times for each chain entry. The time listing is incompatible with the input syntax used by the &man.ipfw.8; utility. -N Attempt to resolve given addresses and service names. Flushing the IPFW rules The syntax for flushing the chain is: ipfw flush This causes all entries in the firewall chain to be removed except the fixed default policy enforced by the kernel (index 65535). Use caution when flushing rules, the default deny policy will leave your system cut off from the network until allow entries are added to the chain. Clearing the IPFW packet counters The syntax for clearing one or more packet counters is: ipfw zero index When used without an index argument, all packet counters are cleared. If an index is supplied, the clearing operation only affects a specific chain entry. Example commands for ipfw This command will deny all packets from the host evil.crackers.org to the telnet port of the host nice.people.org: &prompt.root ipfw add deny tcp from evil.crackers.org to nice.people.org 23 The next example denies and logs any TCP traffic from the entire crackers.org network (a class C) to the nice.people.org machine (any port). &prompt.root; ipfw add deny log tcp from evil.crackers.org/24 to nice.people.org If you do not want people sending X sessions to your internal network (a subnet of a class C), the following command will do the necessary filtering: &prompt.root; ipfw add deny tcp from any to my.org/28 6000 setup To see the accounting records: &prompt.root; ipfw -a list or in the short form &prompt.root; ipfw -a l You can also see the last time a chain entry was matched with: &prompt.root; ipfw -at l Building a packet filtering firewall The following suggestions are just that: suggestions. The requirements of each firewall are different and we cannot tell you how to build a firewall to meet your particular requirements. When initially setting up your firewall, unless you have a test bench setup where you can configure your firewall host in a controlled environment, it is strongly recommend you use the logging version of the commands and enable logging in the kernel. This will allow you to quickly identify problem areas and cure them without too much disruption. Even after the initial setup phase is complete, I recommend using the logging for `deny' as it allows tracing of possible attacks and also modification of the firewall rules if your requirements alter. If you use the logging versions of the accept command, it can generate large amounts of log data as one log line will be generated for every packet that passes through the firewall, so large ftp/http transfers, etc, will really slow the system down. It also increases the latencies on those packets as it requires more work to be done by the kernel before the packet can be passed on. syslogd with also start using up a lot more processor time as it logs all the extra data to disk, and it could quite easily fill the partition /var/log is located on. You should enable your firewall from /etc/rc.conf.local or /etc/rc.conf. The associated man page explains which knobs to fiddle and lists some preset firewall configurations. If you do not use a preset configuration, ipfw list will output the current ruleset into a file that you can pass to rc.conf. If you do not use /etc/rc.conf.local or /etc/rc.conf to enable your firewall, it is important to make sure your firewall is enabled before any IP interfaces are configured. The next problem is what your firewall should actually do! This is largely dependent on what access to your network you want to allow from the outside, and how much access to the outside world you want to allow from the inside. Some general rules are: Block all incoming access to ports below 1024 for TCP. This is where most of the security sensitive services are, like finger, SMTP (mail) and telnet. Block all incoming UDP traffic. There are very few useful services that travel over UDP, and what useful - traffic there is is normally a security threat (e.g. Suns RPC and + traffic there is normally a security threat (e.g. Suns RPC and NFS protocols). This has its disadvantages also, since UDP is a connectionless protocol, denying incoming UDP traffic also blocks the replies to outgoing UDP traffic. This can cause a problem for people (on the inside) using external archie (prospero) servers. If you want to allow access to archie, you'll have to allow packets coming from ports 191 and 1525 to any internal UDP port through the firewall. ntp is another service you may consider allowing through, which comes from port 123. Block traffic to port 6000 from the outside. Port 6000 is the port used for access to X11 servers, and can be a security threat (especially if people are in the habit of doing xhost + on their workstations). X11 can actually use a range of ports starting at 6000, the upper limit being how many X displays you can run on the machine. The upper limit as defined by RFC 1700 (Assigned Numbers) is 6063. Check what ports any internal servers use (e.g. SQL servers, etc). It is probably a good idea to block those as well, as they normally fall outside the 1-1024 range specified above. Another checklist for firewall configuration is available from CERT at http://www.cert.org/tech_tips/packet_filtering.html As stated above, these are only guidelines. You will have to decide what filter rules you want to use on your firewall yourself. We cannot accept ANY responsibility if someone breaks into your network, even if you follow the advice given above. OpenSSL As of FreeBSD 4.0, the OpenSSL toolkit is a part of the base system. OpenSSL provides a general-purpose cryptography library, as well as the Secure Sockets Layer v2/v3 (SSLv2/SSLv3) and Transport Layer Security v1 (TLSv1) network security protocols. However, one of the algorithms (specifically IDEA) included in OpenSSL is protected by patents in the USA and elsewhere, and is not available for unrestricted use. IDEA is included in the OpenSSL sources in FreeBSD, but it is not built by default. If you wish to use it, and you comply with the license terms, enable the MAKE_IDEA switch in /etc/make.conf and rebuild your sources using 'make world'. Today, the RSA algorithm is free for use in USA and other countries. In the past it was protected by a patent. Source Code Installations OpenSSL is part of the src-crypto and src-secure cvsup collections. See the Obtaining FreeBSD section for more information about obtaining and updating FreeBSD source code. IPsec Contributed by &a.shin;, 5 March 2000. The IPsec mechanism provides secure communication either for IP layer and socket layer communication. This section should explain how to use them. For implementation details, please refer to The Developers' Handbook. The current IPsec implementation supports both transport mode and tunnel mode. However, tunnel mode comes with some restrictions. http://www.kame.net/newsletter/ has more comprehensive examples. Please be aware that in order to use this functionality, you must have the following options compiled into your kernel: options IPSEC #IP security options IPSEC_ESP #IP security (crypto; define w/IPSEC) Transport mode example with IPv4 Let's setup security association to deploy a secure channel between HOST A (10.2.3.4) and HOST B (10.6.7.8). Here we show a little complicated example. From HOST A to HOST B, only old AH is used. From HOST B to HOST A, new AH and new ESP are combined. Now we should choose algorithm to be used corresponding to "AH"/"new AH"/"ESP"/"new ESP". Please refer to the &man.setkey.8; man page to know algorithm names. Our choice is MD5 for AH, new-HMAC-SHA1 for new AH, and new-DES-expIV with 8 byte IV for new ESP. Key length highly depends on each algorithm. For example, key length must be equal to 16 bytes for MD5, 20 for new-HMAC-SHA1, and 8 for new-DES-expIV. Now we choose "MYSECRETMYSECRET", "KAMEKAMEKAMEKAMEKAME", "PASSWORD", respectively. OK, let's assign SPI (Security Parameter Index) for each protocol. Please note that we need 3 SPIs for this secure channel since three security headers are produced (one for from HOST A to HOST B, two for from HOST B to HOST A). Please also note that SPI MUST be greater than or equal to 256. We choose, 1000, 2000, and 3000, respectively. (1) HOST A ------> HOST B (1)PROTO=AH ALG=MD5(RFC1826) KEY=MYSECRETMYSECRET SPI=1000 (2.1) HOST A <------ HOST B <------ (2.2) (2.1) PROTO=AH ALG=new-HMAC-SHA1(new AH) KEY=KAMEKAMEKAMEKAMEKAME SPI=2000 (2.2) PROTO=ESP ALG=new-DES-expIV(new ESP) IV length = 8 KEY=PASSWORD SPI=3000 Now, let's setup security association. Execute &man.setkey.8; on both HOST A and B: &prompt.root; setkey -c add 10.2.3.4 10.6.7.8 ah-old 1000 -m transport -A keyed-md5 "MYSECRETMYSECRET" ; add 10.6.7.8 10.2.3.4 ah 2000 -m transport -A hmac-sha1 "KAMEKAMEKAMEKAMEKAME" ; add 10.6.7.8 10.2.3.4 esp 3000 -m transport -E des-cbc "PASSWORD" ; ^D Actually, IPsec communication doesn't process until security policy entries will be defined. In this case, you must setup each host. At A: &prompt.root; setkey -c spdadd 10.2.3.4 10.6.7.8 any -P out ipsec ah/transport/10.2.3.4-10.6.7.8/require ; ^D At B: &prompt.root; setkey -c spdadd 10.6.7.8 10.2.3.4 any -P out ipsec esp/transport/10.6.7.8-10.2.3.4/require ; spdadd 10.6.7.8 10.2.3.4 any -P out ipsec ah/transport/10.6.7.8-10.2.3.4/require ; ^D HOST A --------------------------------------> HOST E 10.2.3.4 10.6.7.8 | | ========== old AH keyed-md5 ==========> <========= new AH hmac-sha1 =========== <========= new ESP des-cbc ============ Transport mode example with IPv6 Another example using IPv6. ESP transport mode is recommended for TCP port number 110 between Host-A and Host-B. ============ ESP ============ | | Host-A Host-B fec0::10 -------------------- fec0::11 Encryption algorithm is blowfish-cbc whose key is "kamekame", and authentication algorithm is hmac-sha1 whose key is "this is the test key". Configuration at Host-A: &prompt.root; setkey -c <<EOF spdadd fec0::10[any] fec0::11[110] tcp -P out ipsec esp/transport/fec0::10-fec0::11/use ; spdadd fec0::11[110] fec0::10[any] tcp -P in ipsec esp/transport/fec0::11-fec0::10/use ; add fec0::10 fec0::11 esp 0x10001 -m transport -E blowfish-cbc "kamekame" -A hmac-sha1 "this is the test key" ; add fec0::11 fec0::10 esp 0x10002 -m transport -E blowfish-cbc "kamekame" -A hmac-sha1 "this is the test key" ; EOF and at Host-B: &prompt.root; setkey -c <<EOF spdadd fec0::11[110] fec0::10[any] tcp -P out ipsec esp/transport/fec0::11-fec0::10/use ; spdadd fec0::10[any] fec0::11[110] tcp -P in ipsec esp/transport/fec0::10-fec0::11/use ; add fec0::10 fec0::11 esp 0x10001 -m transport -E blowfish-cbc "kamekame" -A hmac-sha1 "this is the test key" ; add fec0::11 fec0::10 esp 0x10002 -m transport -E blowfish-cbc "kamekame" -A hmac-sha1 "this is the test key" ; EOF Note the direction of SP. Tunnel mode example with IPv4 Tunnel mode between two security gateways Security protocol is old AH tunnel mode, i.e. specified by RFC1826, with keyed-md5 whose key is "this is the test" as authentication algorithm. ======= AH ======= | | Network-A Gateway-A Gateway-B Network-B 10.0.1.0/24 ---- 172.16.0.1 ----- 172.16.0.2 ---- 10.0.2.0/24 Configuration at Gateway-A: &prompt.root; setkey -c <<EOF spdadd 10.0.1.0/24 10.0.2.0/24 any -P out ipsec ah/tunnel/172.16.0.1-172.16.0.2/require ; spdadd 10.0.2.0/24 10.0.1.0/24 any -P in ipsec ah/tunnel/172.16.0.2-172.16.0.1/require ; add 172.16.0.1 172.16.0.2 ah-old 0x10003 -m any -A keyed-md5 "this is the test" ; add 172.16.0.2 172.16.0.1 ah-old 0x10004 -m any -A keyed-md5 "this is the test" ; EOF If port number field is omitted such above then "[any]" is employed. `-m' specifies the mode of SA to be used. "-m any" means wild-card of mode of security protocol. You can use this SA for both tunnel and transport mode. and at Gateway-B: &prompt.root; setkey -c <<EOF spdadd 10.0.2.0/24 10.0.1.0/24 any -P out ipsec ah/tunnel/172.16.0.2-172.16.0.1/require ; spdadd 10.0.1.0/24 10.0.2.0/24 any -P in ipsec ah/tunnel/172.16.0.1-172.16.0.2/require ; add 172.16.0.1 172.16.0.2 ah-old 0x10003 -m any -A keyed-md5 "this is the test" ; add 172.16.0.2 172.16.0.1 ah-old 0x10004 -m any -A keyed-md5 "this is the test" ; EOF Making SA bundle between two security gateways AH transport mode and ESP tunnel mode is required between Gateway-A and Gateway-B. In this case, ESP tunnel mode is applied first, and AH transport mode is next. ========== AH ========= | ======= ESP ===== | | | | | Network-A Gateway-A Gateway-B Network-B fec0:0:0:1::/64 --- fec0:0:0:1::1 ---- fec0:0:0:2::1 --- fec0:0:0:2::/64 Tunnel mode example with IPv6 Encryption algorithm is 3des-cbc, and authentication algorithm for ESP is hmac-sha1. Authentication algorithm for AH is hmac-md5. Configuration at Gateway-A: &prompt.root; setkey -c <<EOF spdadd fec0:0:0:1::/64 fec0:0:0:2::/64 any -P out ipsec esp/tunnel/fec0:0:0:1::1-fec0:0:0:2::1/require ah/transport/fec0:0:0:1::1-fec0:0:0:2::1/require ; spdadd fec0:0:0:2::/64 fec0:0:0:1::/64 any -P in ipsec esp/tunnel/fec0:0:0:2::1-fec0:0:0:1::1/require ah/transport/fec0:0:0:2::1-fec0:0:0:1::1/require ; add fec0:0:0:1::1 fec0:0:0:2::1 esp 0x10001 -m tunnel -E 3des-cbc "kamekame12341234kame1234" -A hmac-sha1 "this is the test key" ; add fec0:0:0:1::1 fec0:0:0:2::1 ah 0x10001 -m transport -A hmac-md5 "this is the test" ; add fec0:0:0:2::1 fec0:0:0:1::1 esp 0x10001 -m tunnel -E 3des-cbc "kamekame12341234kame1234" -A hmac-sha1 "this is the test key" ; add fec0:0:0:2::1 fec0:0:0:1::1 ah 0x10001 -m transport -A hmac-md5 "this is the test" ; EOF Making SAs with the different end ESP tunnel mode is required between Host-A and Gateway-A. Encryption algorithm is cast128-cbc, and authentication algorithm for ESP is hmac-sha1. ESP transport mode is recommended between Host-A and Host-B. Encryption algorithm is rc5-cbc, and authentication algorithm for ESP is hmac-md5. ================== ESP ================= | ======= ESP ======= | | | | | Host-A Gateway-A Host-B fec0:0:0:1::1 ---- fec0:0:0:2::1 ---- fec0:0:0:2::2 Configuration at Host-A: &prompt.root; setkey -c <<EOF spdadd fec0:0:0:1::1[any] fec0:0:0:2::2[80] tcp -P out ipsec esp/transport/fec0:0:0:1::1-fec0:0:0:2::2/use esp/tunnel/fec0:0:0:1::1-fec0:0:0:2::1/require ; spdadd fec0:0:0:2::1[80] fec0:0:0:1::1[any] tcp -P in ipsec esp/transport/fec0:0:0:2::2-fec0:0:0:l::1/use esp/tunnel/fec0:0:0:2::1-fec0:0:0:1::1/require ; add fec0:0:0:1::1 fec0:0:0:2::2 esp 0x10001 -m transport -E cast128-cbc "12341234" -A hmac-sha1 "this is the test key" ; add fec0:0:0:1::1 fec0:0:0:2::1 esp 0x10002 -E rc5-cbc "kamekame" -A hmac-md5 "this is the test" ; add fec0:0:0:2::2 fec0:0:0:1::1 esp 0x10003 -m transport -E cast128-cbc "12341234" -A hmac-sha1 "this is the test key" ; add fec0:0:0:2::1 fec0:0:0:1::1 esp 0x10004 -E rc5-cbc "kamekame" -A hmac-md5 "this is the test" ; EOF OpenSSH Contributed by &a.chern;, April 21, 2001. Secure shell 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. ssh 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 Be sure to make the following additions to your rc.conf file: sshd_enable="YES" This will load the ssh daemon the next time your system initializes. Alternatively, you can simply run the sshd daemon. SSH client The &man.ssh.1; utility works similarly to &man.rlogin.1;. &prompt.root ssh user@foobardomain.com Host key not found from the list of known hosts. Are you sure you want to continue connecting (yes/no)? yes Host 'foobardomain.com' added to the list of known hosts. user@foobardomain.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 during the first time connecting. 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 Secure copy The scp command works similarly to rcp; it copies a file to or from a remote machine, except in a secure fashion. &prompt.root scp user@foobardomain.com:/COPYRIGHT COPYRIGHT user@foobardomain.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 scp here. 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. 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 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. 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. &man.ssh-agent.1; and &man.ssh-add.1; are utilities used in managing multiple passworded private keys. SSH 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.bar.com &prompt.user; -2 this forces &man.ssh.1 to use version 2 of the protocol. (Do not use if you are working with older ssh servers) -N indicates no command, or tunnel only. If omitted, &man.ssh.1; would initiate a normal session. -f forces &man.ssh.1; to run in the background. -L indicates a local tunnel in localport:localhost:remoteport fashion. foo.bar.com is the remote/target SSH server. An SSH tunnel works by creating a listen socket on the specified local host and port. It then forwards any connection to the local host/port via the SSH connection to the remote machine on the specified remote port. In the example, port 5023 on localhost is being forwarded to port 23 on 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. A typical SSH Tunnel &prompt.user; ssh -2 -N -f -L 5025:localhost:25 user@mailserver.foobar.com user@mailserver.foobar.com's password: ***** &prompt.user; telnet localhost 5025 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 mailserver.foobar.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. 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; diff --git a/en_US.ISO8859-1/books/porters-handbook/book.sgml b/en_US.ISO8859-1/books/porters-handbook/book.sgml index aa6c3ed589..63e3486280 100644 --- a/en_US.ISO8859-1/books/porters-handbook/book.sgml +++ b/en_US.ISO8859-1/books/porters-handbook/book.sgml @@ -1,4498 +1,4499 @@ %man; %bookinfo; %authors; %mailing-lists; ]> FreeBSD Porter's Handbook The FreeBSD Documentation Project April 2000 2000 The FreeBSD Documentation Project &bookinfo.legalnotice; Making a port yourself So, now you are interested in making your own port or upgrading an existing one? Great! What follows are some guidelines for creating a new port for FreeBSD. If you want to upgrade an existing port, you should read this and then read . When this document is not sufficiently detailed, you should refer to /usr/ports/Mk/bsd.port.mk, which all port Makefiles include. Even if you do not hack Makefiles daily, it is well commented, and you will still gain much knowledge from it. Additionally, you may send specific questions to the &a.ports;. Only a fraction of the variables (VAR) that can be overridden are mentioned in this document. Most (if not all) are documented at the start of bsd.port.mk. This file uses a non-standard tab setting. Emacs and Vim should recognize the setting on loading the file. Both vi and ex can be set to use the correct value by typing :set tabstop=4 once the file has been loaded. Quick Porting This section tells you how to do a quick port. In many cases, it is not enough, but we will see. First, get the original tarball and put it into DISTDIR, which defaults to /usr/ports/distfiles. The following assumes that the software compiled out-of-the-box, i.e., there was absolutely no change required for the port to work on your FreeBSD box. If you needed to change something, you will have to refer to the next section too. Writing the <filename>Makefile</filename> The minimal Makefile would look something like this: # New ports collection makefile for: oneko # Date created: 5 December 1994 # Whom: asami # # $FreeBSD$ # PORTNAME= oneko PORTVERSION= 1.1b CATEGORIES= games MASTER_SITES= ftp://ftp.cs.columbia.edu/archives/X11R5/contrib/ MAINTAINER= asami@FreeBSD.org MAN1= oneko.1 MANCOMPRESSED= yes USE_IMAKE= yes .include <bsd.port.mk> See if you can figure it out. Do not worry about the contents of the $FreeBSD$ line, it will be filled in automatically by CVS when the port is imported to our main ports tree. You can find a more detailed example in the sample Makefile section. Writing the description files There are three description files that are required for any port, whether they actually package or not. They are pkg-comment, pkg-descr, and pkg-plist, and their pkg- prefix distinguishes them from other files. <filename>pkg-comment</filename> This is the one-line description of the port. Please do not include the package name (or version number of the software) in the comment. The comment should begin with a capital, and end without a period. Here is an example: A cat chasing a mouse all over the screen <filename>pkg-descr</filename> This is a longer description of the port. One to a few paragraphs concisely explaining what the port does is sufficient. This is not a manual or an in-depth description on how to use or compile the port! Please be careful if you are copying from the README or manpage; too often they are not a concise description of the port or are in an awkward format (e.g., manpages have justified spacing). If the ported software has an official WWW homepage, you should list it here. Prefix one of the websites with WWW: so that automated tools will work correctly. It is recommended that you sign your name at the end of this file, as in: This is a port of oneko, in which a cat chases a poor mouse all over the screen. : (etc.) WWW: http://www.oneko.org/ - Satoshi asami@cs.berkeley.edu <filename>pkg-plist</filename> This file lists all the files installed by the port. It is also called the “packing list” because the package is generated by packing the files listed here. The pathnames are relative to the installation prefix (usually /usr/local or /usr/X11R6). If you are using the MANn variables (as you should be), do not list any manpages here. Here is a small example: bin/oneko lib/X11/app-defaults/Oneko lib/X11/oneko/cat1.xpm lib/X11/oneko/cat2.xpm lib/X11/oneko/mouse.xpm @dirrm lib/X11/oneko Refer to the &man.pkg.create.1; man page for details on the packing list. You should list all the files, but not the name directories, in the list. Also, if the port creates directories for itself during installation, make sure to add @dirrm lines as necessary to remove them when the port is deleted. It is recommended that you keep all the filenames in this file sorted alphabetically. It will make verifying the changes when you upgrade the port much easier. Creating a packing list manually can be a very tedious task. If the port installs a large numbers of files, creating the packing list automatically might save time. Creating the checksum file Just type make makesum. The ports make rules will automatically generate the file distinfo. Testing the port You should make sure that the port rules do exactly what you want them to do, including packaging up the port. These are the important points you need to verify. pkg-plist does not contain anything not installed by your port pkg-plist contains everything that is installed by your port Your port can be installed multiple times using the reinstall target Your port cleans up after itself upon deinstall Recommended test ordering make install make package make deinstall pkg_add package-name make deinstall make reinstall make package Make sure that there are not any warnings issued in any of the package and deinstall stages. After step 3, check to see if all the new directories are correctly deleted. Also, try using the software after step 4, to ensure that it works correctly when installed from a package. Checking your port with <command>portlint</command> Please use portlint to see if your port conforms to our guidelines. The portlint program is part of the ports collection. In particular, you may want to check if the Makefile is in the right shape and the package is named appropriately. Submitting the port First, make sure you have read the DOs and DON'Ts section. Now that you are happy with your port, the only thing remaining is to put it in the main FreeBSD ports tree and make everybody else happy about it too. We do not need your work directory or the pkgname.tgz package, so delete them now. Next, simply include the output of shar `find port_dir` in a bug report and send it with the &man.send-pr.1; program (see Bug Reports and General Commentary for more information about &man.send-pr.1;. If the uncompressed port is larger than 20KB, you should compress it into a tarfile and use &man.uuencode.1; before including it in the bug report (uuencoded tarfiles are acceptable even if the bug report is smaller than 20KB but are not preferred). Be sure to classify the bug report as category ports and class change-request (Do not mark the report confidential!). Also add a short description of the program you ported to the Description field of the PR and the shar or uuencoded tarfile to the Fix field. The latter one helps the committers a lot, who use scripts for the ports-work. One more time, do not include the original source distfile, the work directory, or the package you built with make package. In the past, we asked you to upload new port submissions in our ftp site (ftp.FreeBSD.org). This is no longer recommended as read access is turned off on the incoming/ directory of that site due to the large amount of pirated software showing up there. We will look at your port, get back to you if necessary, and put it in the tree. Your name will also appear in the list of “Additional FreeBSD contributors” in the FreeBSD Handbook and other files. Isn't that great?!? :-) You can make our work a lot easier, if you use a good description in the synopsis of the problem report. We prefer something like “New port: <short description of the port>” for new ports and “Update port: <category>/<port> <short description of the update>” for port updates. If you stick to this scheme, the chance that one takes a look at your PR soon is much bigger. Slow Porting Ok, so it was not that simple, and the port required some modifications to get it to work. In this section, we will explain, step by step, how to modify it to get it to work with the ports paradigm. How things work First, this is the sequence of events which occurs when the user first types make in your port's directory. You may find that having bsd.port.mk in another window while you read this really helps to understand it. But do not worry if you do not really understand what bsd.port.mk is doing, not many people do... :-> The fetch target is run. The fetch target is responsible for making sure that the tarball exists locally in DISTDIR. If fetch cannot find the required files in DISTDIR it will look up the URL MASTER_SITES, which is set in the Makefile, as well as our main ftp site at ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/, where we put sanctioned distfiles as backup. It will then attempt to fetch the named distribution file with FETCH, assuming that the requesting site has direct access to the Internet. If that succeeds, it will save the file in DISTDIR for future use and proceed. The extract target is run. It looks for your port's distribution file (typically a gzip'd tarball) in DISTDIR and unpacks it into a temporary subdirectory specified by WRKDIR (defaults to work). The patch target is run. First, any patches defined in PATCHFILES are applied. Second, if any patch files named patch-* are found in PATCHDIR (defaults to the files subdirectory), they are applied at this time in alphabetical order. The configure target is run. This can do any one of many different things. If it exists, scripts/configure is run. If HAS_CONFIGURE or GNU_CONFIGURE is set, WRKSRC/configure is run. If USE_IMAKE is set, XMKMF (default: xmkmf -a) is run. The build target is run. This is responsible for descending into the port's private working directory (WRKSRC) and building it. If USE_GMAKE is set, GNU make will be used, otherwise the system make will be used. The above are the default actions. In addition, you can define targets pre-something or post-something, or put scripts with those names, in the scripts subdirectory, and they will be run before or after the default actions are done. For example, if you have a post-extract target defined in your Makefile, and a file pre-build in the scripts subdirectory, the post-extract target will be called after the regular extraction actions, and the pre-build script will be executed before the default build rules are done. It is recommended that you use Makefile targets if the actions are simple enough, because it will be easier for someone to figure out what kind of non-default action the port requires. The default actions are done by the bsd.port.mk targets do-something. For example, the commands to extract a port are in the target do-extract. If you are not happy with the default target, you can fix it by redefining the do-something target in your Makefile. The “main” targets (e.g., extract, configure, etc.) do nothing more than make sure all the stages up to that one are completed and call the real targets or scripts, and they are not intended to be changed. If you want to fix the extraction, fix do-extract, but never ever touch extract! Now that you understand what goes on when the user types make, let us go through the recommended steps to create the perfect port. Getting the original sources Get the original sources (normally) as a compressed tarball (foo.tar.gz or foo.tar.Z) and copy it into DISTDIR. Always use mainstream sources when and where you can. If you cannot find a ftp/http site that is well-connected to the net, or can only find sites that have irritatingly non-standard formats, you might want to put a copy on a reliable ftp or http server that you control (e.g., your home page). Make sure you set MASTER_SITES to reflect your choice. If you cannot find somewhere convenient and reliable to put the distfile we can “house” it ourselves on ftp.FreeBSD.org. The distfile must be placed into ~/public_distfiles/ of someone's freefall account. Ask the person who commits your port to do this. This person will also set MASTER_SITES to MASTER_SITE_LOCAL and MASTER_SITE_SUBDIR to their freefall username. If your port's distfile changes all the time for no good reason, consider putting the distfile in your home page and listing it as the first MASTER_SITES. This will prevent users from getting checksum mismatch errors, and also reduce the workload of maintainers of our ftp site. Also, if there is only one master site for the port, it is recommended that you house a backup at your site and list it as the second MASTER_SITES. If your port requires some additional `patches' that are available on the Internet, fetch them too and put them in DISTDIR. Do not worry if they come from a site other than where you got the main source tarball, we have a way to handle these situations (see the description of PATCHFILES below). Modifying the port Unpack a copy of the tarball in a private directory and make whatever changes are necessary to get the port to compile properly under the current version of FreeBSD. Keep careful track of everything you do, as you will be automating the process shortly. Everything, including the deletion, addition, or modification of files should be doable using an automated script or patch file when your port is finished. If your port requires significant user interaction/customization to compile or install, you should take a look at one of Larry Wall's classic Configure scripts and perhaps do something similar yourself. The goal of the new ports collection is to make each port as “plug-and-play” as possible for the end-user while using a minimum of disk space. Unless explicitly stated, patch files, scripts, and other files you have created and contributed to the FreeBSD ports collection are assumed to be covered by the standard BSD copyright conditions. Patching In the preparation of the port, files that have been added or changed can be picked up with a recursive diff for later feeding to patch. Each set of patches you wish to apply should be collected into a file named patch-* where * denotes the sequence in which the patches will be applied — these are done in alphabetical order, thus aa first, ab second and so on. If you wish, you can use names that indicate the pathnames of the files that are patched, such as patch-Imakefile or patch-src-config.h. These files should be stored in PATCHDIR, from where they will be automatically applied. All patches should be relative to WRKSRC (generally the directory your port's tarball unpacks itself into, that being where the build is done). To make fixes and upgrades easier, you should avoid having more than one patch fix the same file (e.g., patch-aa and patch-ab both changing WRKSRC/foobar.c). Configuring Include any additional customization commands in your configure script and save it in the scripts subdirectory. As mentioned above, you can also do this with Makefile targets and/or scripts with the name pre-configure or post-configure. Handling user input If your port requires user input to build, configure, or install, then set IS_INTERACTIVE in your Makefile. This will allow “overnight builds” to skip your port if the user sets the variable BATCH in his environment (and if the user sets the variable INTERACTIVE, then only those ports requiring interaction are built). It is also recommended that if there are reasonable default answers to the questions, you check the PACKAGE_BUILDING variable and turn off the interactive script when it is set. This will allow us to build the packages for CD-ROMs and ftp. Configuring the Makefile Configuring the Makefile is pretty simple, and again we suggest that you look at existing examples before starting. Also, there is a sample Makefile in this handbook, so take a look and please follow the ordering of variables and sections in that template to make your port easier for others to read. Now, consider the following problems in sequence as you design your new Makefile: The original source Does it live in DISTDIR as a standard gzip'd tarball named something like foozolix-1.2.tar.gz? If so, you can go on to the next step. If not, you should look at overriding any of the DISTNAME, EXTRACT_CMD, EXTRACT_BEFORE_ARGS, EXTRACT_AFTER_ARGS, EXTRACT_SUFX, or DISTFILES variables, depending on how alien a format your port's distribution file is. (The most common case is EXTRACT_SUFX=.tar.Z, when the tarball is condensed by regular compress, not gzip.) In the worst case, you can simply create your own do-extract target to override the default, though this should be rarely, if ever, necessary. <makevar>PORTNAME</makevar> and <makevar>PORTVERSION</makevar> You should set PORTNAME to the base name of your port, and PORTVERSION to the version number of the port. <makevar>PORTREVISION</makevar> and <makevar>PORTEPOCH</makevar> <makevar>PORTREVISION</makevar> The PORTREVISION variable is a monotonically increasing value which is reset to 0 with every increase of PORTVERSION (i.e. every time a new official vendor release is made), and appended to the package name if non-zero. PORTREVISION is increased each time a change is made to the FreeBSD port which significantly affects the content or stucture of the derived package. Examples of when PORTREVISION should be bumped: Addition of patches to correct security vulnerabilities, bugs, or to add new functionality to the FreeBSD port. Changes to the port makefile to enable or disable compile-time options in the package. Changes in the packing list or the install-time behaviour of the package (e.g. change to a script which generates initial data for the package, like ssh host keys). Version bump of a port's shared library dependency (in this case, someone trying to install the old package after installing a newer version of the dependency will fail since it will look for the old libfoo.x instead of libfoo.(x+1)). Silent changes to the port distfile which have significant functional differences, i.e. changes to the distfile requiring a correction to distinfo with no corresponding change to PORTVERSION, where a diff -ru of the old and new versions shows non-trivial changes to the code. Examples of changes which do not require a PORTREVISION bump: Style changes to the port skeleton with no functional change to what appears in the resulting package. Changes to MASTER_SITES or other functional changes to the port which do not effect the resulting package. Trivial patches to the distfile such as correction of typos, which are not important enough that users of the package should go to the trouble of upgrading. Build fixes which cause a package to become compilable where it was previously failing (as long as the changes do not introduce any functional change on any other platforms on which the port did previously build). Since PORTREVISION reflects the content of the package, if no package was previously buildable then there is no need to increase PORTREVISION to mark a change. A rule of thumb is to ask yourself whether a change committed to a port is something which someone, somewhere, would benefit from having (either because of an enhancement, fix, or by virtue that the new package will actually work for them). If yes, the PORTREVISION should be bumped so that automated tools (e.g. pkg_version) will highlight the fact that a new package is available. <makevar>PORTEPOCH</makevar> From time to time a software vendor or FreeBSD porter will do something silly and release a version of their software which is actually numerically less than the previous version. An example of this is a port which goes from foo-20000801 to foo-1.0 (the former will be incorrectly treated as a newer version since 20000801 is a numerically greater value than 1). In situations such as this, the PORTEPOCH version should be increased. If PORTEPOCH is nonzero it is appended to the package name as described in section 0 above. PORTEPOCH is never decreased or reset to zero, because that would cause comparison to a package from an earlier epoch to fail (i.e. the package would not be detected as out of date): the new version number (e.g. 1.0,1 in the above example) is still numerically less than the previous version (2000801), but the ,1 suffix is treated specially by automated tools and found to be greater than the implied suffix ",0" on the earlier package) It is expected that PORTEPOCH will not be used for the majority of ports, and that sensible use of PORTVERSION can often pre-empt it becoming necessary if a future release of the software should change the version structure. However, care is needed by FreeBSD porters when a vendor release is made without an official version number - such as a code "snapshot" release. The temptation is to label the release with the release date, which will cause problems as in the example above when a new "official" release is made. For example, if a snapshot release is made on the date 20000917, and the previous version of the software was version 1.2, the snapshot release should be given a PORTVERSION of 1.2.20000917 or similar, not 20000917, so that the succeeding release, say 1.3, is still a numerically greater value. Example of <makevar>PORTREVISION</makevar> and <makevar>PORTEPOCH</makevar> usage The gtkmumble port, version 0.10, is committed to the ports collection. PORTNAME= gtkmumble PORTVERSION= 0.10 PKGNAME becomes gtkmumble-0.10. A security hole is discovered which requires a local FreeBSD patch. PORTREVISION is bumped accordingly. PORTNAME= gtkmumble PORTVERSIOn= 0.10 PORTREVISION= 1 PKGNAME becomes gtkmumble-0.10_1 A new version is released by the vendor, numbered 0.2 (it turns out the author actually intended 0.10 to actually mean 0.1.0, not what comes after 0.9 - oops, too late now). Since the new minor version 2 is numerically less than the previous version 10 the PORTEPOCH must be bumped to manually force the new package to be detected as "newer". Since it is a new vendor release of the code, PORTREVISION is reset to 0 (or removed from the makefile). PORTNAME= gtkmumble PORTVERSION= 0.2 PORTEPOCH= 1 PKGNAME becomes gtkmumble-0.2,1 The next release is 0.3. Since PORTEPOCH never decreases, the version variables are now: PORTNAME= gtkmumble PORTVERSION= 0.3 PORTEPOCH= 1 PKGNAME becomes gtkmumble-0.3,1 If PORTEPOCH were reset to 0 with this upgrade, someone who had installed the gtkmumble-0.10_1 package would not detect the gtkmumble-0.3 package as newer, since 3 is still numerically less than 10. <makevar>PKGNAMEPREFIX</makevar> and <makevar>PKGNAMESUFFIX</makevar> Two optional variables, PKGNAMEPREFIX and PKGNAMESUFFIX, are combined with PORTNAME and PORTVERSION to form PKGNAME as ${PKGNAMEPREFIX}${PORTNAME}${PKGNAMESUFFIX}-${PORTVERSION}. Make sure this conforms to our guidelines for a good package name. In particular, you are not allowed to use a hyphen (-) in PORTVERSION. Also, if the package name has the language- or the compiled.specifics part, use PKGNAMEPREFIX and PKGNAMESUFFIX, respectively. Do not make them part of PORTNAME. <makevar>DISTNAME</makevar> DISTNAME is the name of the port as called by the authors of the software. DISTNAME defaults to ${PORTNAME}-${PORTVERSION}, so override it if necessary. DISTNAME is only used in two places. First, the distribution file list (DISTFILES) defaults to ${DISTNAME}${EXTRACT_SUFX}. Second, the distribution file is expected to extract into a subdirectory named WRKSRC, which defaults to work/${DISTNAME}. PKGNAMEPREFIX and PKGNAMESUFFIX do not affect DISTNAME. Also note that when WRKSRC is equal to work/${PORTNAME}-${PORTVERSION} while the original source archive is named something other than ${PORTNAME}-${PORTVERSION}${EXTRACT_SUFX}, you should probably leave DISTNAME alone— you are better off defining DISTFILES than having to set both DISTNAME and WRKSRC (and possibly EXTRACT_SUFX). <makevar>CATEGORIES</makevar> When a package is created, it is put under /usr/ports/packages/All and links are made from one or more subdirectories of /usr/ports/packages. The names of these subdirectories are specified by the variable CATEGORIES. It is intended to make life easier for the user when he is wading through the pile of packages on the ftp site or the CD-ROM. Please take a look at the existing categories and pick the ones that are suitable for your port. This list also determines where in the ports tree the port is imported. If you put more than one category here, it is assumed that the port files will be put in the subdirectory with the name in the first category. See the categories section for more discussion about how to pick the right categories. If your port truly belongs to something that is different from all the existing ones, you can even create a new category name. In that case, please send mail to the &a.ports; to propose a new category. <makevar>MASTER_SITES</makevar> Record the directory part of the ftp/http-URL pointing at the original tarball in MASTER_SITES. Do not forget the trailing slash (/)! The make macros will try to use this specification for grabbing the distribution file with FETCH if they cannot find it already on the system. It is recommended that you put multiple sites on this list, preferably from different continents. This will safeguard against wide-area network problems, and we are even planning to add support for automatically determining the closest master site and fetching from there! If the original tarball is part of one of the popular archives such as X-contrib, GNU, or Perl CPAN, you may be able refer to those sites in an easy compact form using MASTER_SITE_* (e.g., MASTER_SITE_XCONTRIB and MASTER_SITE_PERL_GNU). Simply set MASTER_SITES to one of these variables and MASTER_SITE_SUBDIR to the path within the archive. Here is an example: MASTER_SITES= ${MASTER_SITE_XCONTRIB} MASTER_SITE_SUBDIR= applications These variables are defined in /usr/ports/Mk/bsd.sites.mk. There are new archives added all the time, so make sure to check the latest version of this file before submitting a port. The user can also set the MASTER_SITE_* variables in /etc/make.conf to override our choices, and use their favorite mirrors of these popular archives instead. <makevar>PATCHFILES</makevar> If your port requires some additional patches that are available by ftp or http, set PATCHFILES to the names of the files and PATCH_SITES to the URL of the directory that contains them (the format is the same as MASTER_SITES). If the patch is not relative to the top of the source tree (i.e., WRKSRC) because it contains some extra pathnames, set PATCH_DIST_STRIP accordingly. For instance, if all the pathnames in the patch have an extra foozolix-1.0/ in front of the filenames, then set PATCH_DIST_STRIP=-p1. Do not worry if the patches are compressed; they will be decompressed automatically if the filenames end with .gz or .Z. If the patch is distributed with some other files, such as documentation, in a gzip'd tarball, you cannot just use PATCHFILES. If that is the case, add the name and the location of the patch tarball to DISTFILES and MASTER_SITES. Then, use the EXTRA_PATCHES variable to point to those files and bsd.port.mk will automatically apply them for you. In particular, do not copy patch files into the PATCHDIR directory—that directory may not be writable. Note that the tarball will have been extracted alongside the regular source by then, so there is no need to explicitly extract it if it is a regular gzip'd or compress'd tarball. If you do the latter, take extra care not to overwrite something that already exists in that directory. Also, do not forget to add a command to remove the copied patch in the pre-clean target. <makevar>MAINTAINER</makevar> Set your mail-address here. Please. :-) For a detailed description of the responsibilities of maintainers, refer to the MAINTAINER on Makefiles section. Dependencies Many ports depend on other ports. There are five variables that you can use to ensure that all the required bits will be on the user's machine. There are also some pre-supported dependency variables for common cases, plus a few more to control the behaviour of dependencies. <makevar>LIB_DEPENDS</makevar> This variable specifies the shared libraries this port depends on. It is a list of lib:dir:target tuples where lib is the name of the shared library, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. For example, LIB_DEPENDS= jpeg.9:${PORTSDIR}/graphics/jpeg:install will check for a shared jpeg library with major version 9, and descend into the graphics/jpeg subdirectory of your ports tree to build and install it if it is not found. The target part can be omitted if it is equal to DEPENDS_TARGET (which defaults to install). The lib part is an argument given to ldconfig -r | grep -wF. There shall be no regular expressions in this variable. The dependency is checked twice, once from within the extract target and then from within the install target. Also, the name of the dependency is put into the package so that pkg_add will automatically install it if it is not on the user's system. <makevar>RUN_DEPENDS</makevar> This variable specifies executables or files this port depends on during run-time. It is a list of path:dir:target tuples where path is the name of the executable or file, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. If path starts with a slash (/), it is treated as a file and its existence is tested with test -e; otherwise, it is assumed to be an executable, and which -s is used to determine if the program exists in the user's search path. For example, RUN_DEPENDS= ${PREFIX}/etc/innd:${PORTSDIR}/news/inn \ wish8.0:${PORTSDIR}/x11-toolkits/tk80 will check if the file or directory /usr/local/etc/innd exists, and build and install it from the news/inn subdirectory of the ports tree if it is not found. It will also see if an executable called wish8.0 is in your search path, and descend into the x11-toolkits/tk80 subdirectory of your ports tree to build and install it if it is not found. In this case, innd is actually an executable; if an executable is in a place that is not expected to be in a normal user's search path, you should use the full pathname. The dependency is checked from within the install target. Also, the name of the dependency is put in to the package so that pkg_add will automatically install it if it is not on the user's system. The target part can be omitted if it is the same as DEPENDS_TARGET. <makevar>BUILD_DEPENDS</makevar> This variable specifies executables or files this port requires to build. Like RUN_DEPENDS, it is a list of path:dir:target tuples. For example, BUILD_DEPENDS= unzip:${PORTSDIR}/archivers/unzip will check for an executable called unzip, and descend into the archivers/unzip subdirectory of your ports tree to build and install it if it is not found. “build” here means everything from extraction to compilation. The dependency is checked from within the extract target. The target part can be omitted if it is the same as DEPENDS_TARGET <makevar>FETCH_DEPENDS</makevar> This variable specifies executables or files this port requires to fetch. Like the previous two, it is a list of path:dir:target tuples. For example, FETCH_DEPENDS= ncftp2:${PORTSDIR}/net/ncftp2 will check for an executable called ncftp2, and descend into the net/ncftp2 subdirectory of your ports tree to build and install it if it is not found. The dependency is checked from within the fetch target. The target part can be omitted if it is the same as DEPENDS_TARGET. <makevar>DEPENDS</makevar> If there is a dependency that does not fall into either of the above four categories, or your port requires having the source of the other port extracted in addition to having it installed, then use this variable. This is a list of dir:target, as there is nothing to check, unlike the previous four. The target part can be omitted if it is the same as DEPENDS_TARGET. Common dependency variables Define USE_XLIB=yes if your port requires the X Window System to be installed (it is implied by USE_IMAKE). Define USE_GMAKE=yes if your port requires GNU make instead of BSD make. Define USE_AUTOCONF=yes if your port requires GNU autoconf to be run. Define USE_QT=yes if your port uses the latest qt toolkit. Use USE_PERL5=yes if your port requires version 5 of the perl language. (The last is especially important since some versions of FreeBSD have perl5 as part of the base system while others do not.) Notes on dependencies As mentioned above, the default target to call when a dependency is required is DEPENDS_TARGET. It defaults to install. This is a user variable; it is never defined in a port's Makefile. If your port needs a special way to handle a dependency, use the :target part of the *_DEPENDS variables instead of redefining DEPENDS_TARGET. When you type make clean, its dependencies are automatically cleaned too. If you do not wish this to happen, define the variable NOCLEANDEPENDS in your environment. To depend on another port unconditionally, use the variable ${NONEXISTENT} as the first field of BUILD_DEPENDS or RUN_DEPENDS. Use this only when you need to the to get to the source of the other port. You can often save compilation time by specifying the target too. For instance BUILD_DEPENDS= ${NONEXISTENT}:${PORTSDIR}/graphics/jpeg:extract will always descend to the JPEG port and extract it. Do not use DEPENDS unless there is no other way the behaviour you want can be accomplished. It will cause the other port to always be built (and installed, by default), and the dependency will go into the packages as well. If this is really what you need, you should probably write it as BUILD_DEPENDS and RUN_DEPENDS instead—at least the intention will be clear. Optional dependencies Some large applications can be built in a number of configurations, adding functionality if one of a number of libraries or applications is available. Since not all users want those libraries or applications, the ports system provides hooks that the port author can use to decide which configuration should be built. Supporting these properly will make uses happy, and effectively provide 2 or more ports for the price of one. The easiest of these to use is WITHOUT_X11. If the port can be built both with and without X support, then it should normally be built with X support. If WITHOUT_X11 is defined, then the version that does not have X support should be built. Various parts of GNOME have such knobs, though they are slightly more difficult to use. The variables to use in the Makefile are WANT_* and HAVE_*. If the application can be built both with or without one of the dependencies listed below, then the Makefile should set WANT_PKG, and should build the version that uses PKG if HAVE_PKG is defined. The WANT_* variables currently supported this way are WANT_GLIB, WANT_GTK, WANT_ESOUND, WANT_IMLIB, and WANT_GNOME. Building mechanisms If your package uses GNU make, set USE_GMAKE=yes. If your package uses configure, set HAS_CONFIGURE=yes. If your package uses GNU configure, set GNU_CONFIGURE=yes (this implies HAS_CONFIGURE). If you want to give some extra arguments to configure (the default argument list --prefix=${PREFIX} for GNU configure and empty for non-GNU configure), set those extra arguments in CONFIGURE_ARGS. If your package uses GNU autoconf, set USE_AUTOCONF=yes. This implies GNU_CONFIGURE, and will cause autoconf to be run before configure. If your package is an X application that creates Makefiles from Imakefiles using imake, then set USE_IMAKE=yes. This will cause the configure stage to automatically do an xmkmf -a. If the flag is a problem for your port, set XMKMF=xmkmf. If the port uses imake but does not understand the install.man target, NO_INSTALL_MANPAGES=yes should be set. In addition, the author of the original port should be shot. :-> If your port's source Makefile has something else than all as the main build target, set ALL_TARGET accordingly. Same goes for install and INSTALL_TARGET. Special considerations There are some more things you have to take into account when you create a port. This section explains the most common of those. Shared Libraries If your port installs one or more shared libraries, define a INSTALLS_SHLIB make variable, which will instruct a bsd.port.mk to run ${LDCONFIG} -m on the directory where the new library is installed (usually PREFIX/lib) during post-install target to register it into the shared library cache. This variable, when defined, will also facilitate addition of an appropriate @exec /sbin/ldconfig -m and @unexec /sbin/ldconfig -R pair into your pkg-plist file, so that a user who installed the package can start using the shared library immediately and deinstallation will not cause the system to still believe the library is there. If you need, you can override default location where the new library is installed by defining LDCONFIG_DIRS make variable, which should contain a list of directories into which shared libraries are to be installed. For example if your port installs shared libraries into PREFIX/lib/foo and PREFIX/lib/bar directories you could use the following in your Makefile: INSTALLS_SHLIB= yes LDCONFIG_DIRS= %%PREFIX%%/lib/foo %%PREFIX%%/lib/bar Note that content of LDCONFIG_DIRS is passed through &man.sed.1; just like the rest of pkg-plist, so PLIST_SUB substitutions also apply here. It is recommended that you use %%PREFIX%% for PREFIX, %%LOCALBASE%% for LOCALBASE and %%X11BASE%% for X11BASE. <makevar>MASTERDIR</makevar> If your port needs to build slightly different versions of packages by having a variable (for instance, resolution, or paper size) take different values, create one subdirectory per package to make it easier for users to see what to do, but try to share as many files as possible between ports. Typically you only need a very short Makefile in all but one of the directories if you use variables cleverly. In the sole Makefiles, you can use MASTERDIR to specify the directory where the rest of the files are. Also, use a variable as part of PKGNAMESUFFIX so the packages will have different names. This will be best demonstrated by an example. This is part of japanese/xdvi300/Makefile; PORTNAME= xdvi PORTVERSION= 17 PKGNAMEPREFIX= ja- PKGNAMESUFFIX= ${RESOLUTION} : # default RESOLUTION?= 300 .if ${RESOLUTION} != 118 && ${RESOLUTION} != 240 && \ ${RESOLUTION} != 300 && ${RESOLUTION} != 400 @${ECHO} "Error: invalid value for RESOLUTION: \"${RESOLUTION}\"" @${ECHO} "Possible values are: 118, 240, 300 (default) and 400." @${FALSE} .endif japanese/xdvi300 also has all the regular patches, package files, etc. If you type make there, it will take the default value for the resolution (300) and build the port normally. As for other resolutions, this is the entire xdvi118/Makefile: RESOLUTION= 118 MASTERDIR= ${.CURDIR}/../xdvi300 .include ${MASTERDIR}/Makefile (xdvi240/Makefile and xdvi400/Makefile are similar). The MASTERDIR definition tells bsd.port.mk that the regular set of subdirectories like FILESDIR and SCRIPTDIR are to be found under xdvi300. The RESOLUTION=118 line will override the RESOLUTION=300 line in xdvi300/Makefile and the port will be built with resolution set to 118. Shared library versions Please read our policy on shared library versioning to understand what to do with shared library versions in general. Do not blindly assume software authors know what they are doing; many of them do not. It is very important that these details are carefully considered, as we have quite a unique situation where we are trying to have dozens of potentially incompatible software pairs co-exist. Careless port imports have caused great trouble regarding shared libraries in the past (ever wondered why the port jpeg-6b has a shared library version of 9?). If in doubt, send a message to the &a.ports;. Most of the time, your job ends by determining the right shared library version and making appropriate patches to implement it. Manpages The MAN[1-9LN] variables will automatically add any manpages to pkg-plist (this means you must not list manpages in the pkg-plist—see generating PLIST for more). It also makes the install stage automatically compress or uncompress manpages depending on the setting of NOMANCOMPRESS in /etc/make.conf. If your port tries to install multiple names for manpages using symlinks or hardlinks, you must use the MLINKS variable to identify these. The link installed by your port will be destroyed and recreated by bsd.port.mk to make sure it points to the correct file. Any manpages listed in MLINKS must not be listed in the pkg-plist. To specify whether the manpages are compressed upon installation, use the MANCOMPRESSED variable. This variable can take three values, yes, no and maybe. yes means manpages are already installed compressed, no means they are not, and maybe means the software already respects the value of NOMANCOMPRESS so bsd.port.mk does not have to do anything special. MANCOMPRESSED is automatically set to yes if USE_IMAKE is set and NO_INSTALL_MANPAGES is not set, and to no otherwise. You do not have to explicitly define it unless the default is not suitable for your port. If your port anchors its man tree somewhere other than PREFIX, you can use the MANPREFIX to set it. Also, if only manpages in certain sections go in a non-standard place, such as some Perl modules ports, you can set individual man paths using MANsectPREFIX (where sect is one of 1-9, L or N). If your manpages go to language-specific subdirectories, set the name of the languages to MANLANG. The value of this variable defaults to "" (i.e., English only). Here is an example that puts it all together. MAN1= foo.1 MAN3= bar.3 MAN4= baz.4 MLINKS= foo.1 alt-name.8 MANLANG= "" ja MAN3PREFIX= ${PREFIX}/share/foobar MANCOMPRESSED= yes This states that six files are installed by this port; ${PREFIX}/man/man1/foo.1.gz ${PREFIX}/man/ja/man1/foo.1.gz ${PREFIX}/share/foobar/man/man3/bar.3.gz ${PREFIX}/share/foobar/man/ja/man3/bar.3.gz ${PREFIX}/man/man4/baz.4.gz ${PREFIX}/man/ja/man4/baz.4.gz Additionally ${PREFIX}/man/man8/alt-name.8.gz may or may not be installed by your port. Regardless, a symlink will be made to join the foo(1) manpage and alt-name(8) manpage. Ports that require Motif There are many programs that require a Motif library (available from several commercial vendors, while there is a free clone reported to be able to run many applications in x11-toolkits/lesstif) to compile. Since it is a popular toolkit and their licenses usually permit redistribution of statically linked binaries, we have made special provisions for handling ports that require Motif in a way that we can easily compile binaries linked either dynamically (for people who are compiling from the port) or statically (for people who distribute packages). <makevar>REQUIRES_MOTIF</makevar> If your port requires Motif, define this variable in the Makefile. This will prevent people who do not own a copy of Motif from even attempting to build it. <makevar>MOTIFLIB</makevar> This variable will be set by bsd.port.mk to be the appropriate reference to the Motif library. Please patch the source to use this wherever the Motif library is referenced in the Makefile or Imakefile. There are two common cases: If the port refers to the Motif library as -lXm in its Makefile or Imakefile, simply substitute ${MOTIFLIB} for it. If the port uses XmClientLibs in its Imakefile, change it to ${MOTIFLIB} ${XTOOLLIB} ${XLIB}. Note that MOTIFLIB (usually) expands to -L/usr/X11R6/lib -lXm or /usr/X11R6/lib/libXm.a, so there is no need to add -L or -l in front. X11 fonts If your port installs fonts for the X Window system, put them in X11BASE/lib/X11/fonts/local. This directory is new to XFree86 release 3.3.3. If it does not exist, please create it, and print out a message urging the user to update their XFree86 to 3.3.3 or newer, or at least add this directory to the font path in /etc/XF86Config. Info files The new version of texinfo (included in 2.2.2-RELEASE and onwards) contains a utility called install-info to add and delete entries to the dir file. If your port installs any info documents, please follow these instructions so your port/package will correctly update the user's PREFIX/info/dir file. (Sorry for the length of this section, but is it imperative to weave all the info files together. If done correctly, it will produce a beautiful listing, so please bear with me! First, this is what you (as a porter) need to know &prompt.user; install-info --help install-info [OPTION]... [INFO-FILE [DIR-FILE]] Install INFO-FILE in the Info directory file DIR-FILE. Options: --delete Delete existing entries in INFO-FILE; don't insert any new entries. : --entry=TEXT Insert TEXT as an Info directory entry. : --section=SEC Put this file's entries in section SEC of the directory. : This program will not actually install info files; it merely inserts or deletes entries in the dir file. Here's a seven-step procedure to convert ports to use install-info. editors/emacs will be used as an example. Look at the texinfo sources and make a patch to insert @dircategory and @direntry statements to files that do not have them. This is part of my patch: --- ./man/vip.texi.org Fri Jun 16 15:31:11 1995 +++ ./man/vip.texi Tue May 20 01:28:33 1997 @@ -2,6 +2,10 @@ @setfilename ../info/vip @settitle VIP +@dircategory The Emacs editor and associated tools +@direntry +* VIP: (vip). A VI-emulation for Emacs. +@end direntry @iftex @finalout : The format should be self-explanatory. Many authors leave a dir file in the source tree that contains all the entries you need, so look around before you try to write your own. Also, make sure you look into related ports and make the section names and entry indentations consistent (we recommend that all entry text start at the 4th tab stop). Note that you can put only one info entry per file because of a bug in install-info --delete that deletes only the first entry if you specify multiple entries in the @direntry section. You can give the dir entries to install-info as arguments ( and ) instead of patching the texinfo sources. This probably is not a good idea for ports because you need to duplicate the same information in three places (Makefile and @exec/@unexec of pkg-plist; see below). However, if you have Japanese (or other multibyte encoding) info files, you will have to use the extra arguments to install-info because makeinfo cannot handle those texinfo sources. (See Makefile and pkg-plist of japanese/skk for examples on how to do this). Go back to the port directory and do a make clean; make and verify that the info files are regenerated from the texinfo sources. Since the texinfo sources are newer than the info files, they should be rebuilt when you type make; but many Makefiles do not include correct dependencies for info files. In emacs' case, it was necessary to patch the main Makefile.in so it would descend into the man subdirectory to rebuild the info pages. --- ./Makefile.in.org Mon Aug 19 21:12:19 1996 +++ ./Makefile.in Tue Apr 15 00:15:28 1997 @@ -184,7 +184,7 @@ # Subdirectories to make recursively. `lisp' is not included # because the compiled lisp files are part of the distribution # and you cannot remake them without installing Emacs first. -SUBDIR = lib-src src +SUBDIR = lib-src src man # The makefiles of the directories in $SUBDIR. SUBDIR_MAKEFILES = lib-src/Makefile man/Makefile src/Makefile oldXMenu/Makefile lwlib/Makefile --- ./man/Makefile.in.org Thu Jun 27 15:27:19 1996 +++ ./man/Makefile.in Tue Apr 15 00:29:52 1997 @@ -66,6 +66,7 @@ ${srcdir}/gnu1.texi \ ${srcdir}/glossary.texi +all: info info: $(INFO_TARGETS) dvi: $(DVI_TARGETS) The second hunk was necessary because the default target in the man subdir is called info, while the main Makefile wants to call all. The installation of the info info file was also removed because we already have one with the same name in /usr/share/info (that patch is not shown here). If there is a place in the Makefile that is installing the dir file, delete it. Your port may not be doing it. Also, remove any commands that are otherwise mucking around with the dir file. --- ./Makefile.in.org Mon Aug 19 21:12:19 1996 +++ ./Makefile.in Mon Apr 14 23:38:07 1997 @@ -368,14 +368,8 @@ if [ `(cd ${srcdir}/info && /bin/pwd)` != `(cd ${infodir} && /bin/pwd)` ]; \ then \ (cd ${infodir}; \ - if [ -f dir ]; then \ - if [ ! -f dir.old ]; then mv -f dir dir.old; \ - else mv -f dir dir.bak; fi; \ - fi; \ cd ${srcdir}/info ; \ - (cd $${thisdir}; ${INSTALL_DATA} ${srcdir}/info/dir ${infodir}/dir); \ - (cd $${thisdir}; chmod a+r ${infodir}/dir); \ for f in ccmode* cl* dired-x* ediff* emacs* forms* gnus* info* message* mh-e* sc* vip*; do \ (cd $${thisdir}; \ ${INSTALL_DATA} ${srcdir}/info/$$f ${infodir}/$$f; \ chmod a+r ${infodir}/$$f); \ (This step is only necessary if you are modifying an existing port.) Take a look at pkg-plist and delete anything that is trying to patch up info/dir. They may be in pkg-install or some other file, so search extensively. Index: pkg-plist =================================================================== RCS file: /usr/cvs/ports/editors/emacs/pkg-plist,v retrieving revision 1.15 diff -u -r1.15 pkg-plist --- pkg-plist 1997/03/04 08:04:00 1.15 +++ pkg-plist 1997/04/15 06:32:12 @@ -15,9 +15,6 @@ man/man1/emacs.1.gz man/man1/etags.1.gz man/man1/ctags.1.gz -@unexec cp %D/info/dir %D/info/dir.bak -info/dir -@unexec cp %D/info/dir.bak %D/info/dir info/cl info/cl-1 info/cl-2 Add a post-install target to the Makefile to call install-info with the installed info files. (It is no longer necessary to create the dir file yourself; install-info automatically creates this file if it does not exist.) Index: Makefile =================================================================== RCS file: /usr/cvs/ports/editors/emacs/Makefile,v retrieving revision 1.26 diff -u -r1.26 Makefile --- Makefile 1996/11/19 13:14:40 1.26 +++ Makefile 1997/05/20 10:25:09 1.28 @@ -20,5 +20,8 @@ post-install: .for file in emacs-19.34 emacsclient etags ctags b2m strip ${PREFIX}/bin/${file} .endfor +.for info in emacs vip viper forms gnus mh-e cl sc dired-x ediff ccmode + install-info ${PREFIX}/info/${info} ${PREFIX}/info/dir +.endfor .include <bsd.port.mk> Edit pkg-plist and add equivalent @exec statements and also @unexec for pkg_delete. Index: pkg-plist =================================================================== RCS file: /usr/cvs/ports/editors/emacs/pkg-plist,v retrieving revision 1.15 diff -u -r1.15 pkg-plist --- pkg-plist 1997/03/04 08:04:00 1.15 +++ pkg-plist 1997/05/20 10:25:12 1.17 @@ -16,7 +14,14 @@ man/man1/etags.1.gz man/man1/ctags.1.gz +@unexec install-info --delete %D/info/emacs %D/info/dir : +@unexec install-info --delete %D/info/ccmode %D/info/dir info/cl info/cl-1 @@ -87,6 +94,18 @@ info/viper-3 info/viper-4 +@exec install-info %D/info/emacs %D/info/dir : +@exec install-info %D/info/ccmode %D/info/dir libexec/emacs/19.34/i386--freebsd/cvtmail libexec/emacs/19.34/i386--freebsd/digest-doc The @unexec install-info --delete commands have to be listed before the info files themselves so they can read the files. Also, the @exec install-info commands have to be after the info files and the @exec command that creates the the dir file. Test and admire your work. :-). Check the dir file before and after each step. The <filename>pkg-<replaceable>*</replaceable></filename> files There are some tricks we have not mentioned yet about the pkg-* files that come in handy sometimes. <filename>pkg-message</filename> If you need to display a message to the installer, you may place the message in pkg-message. This capability is often useful to display additional installation steps to be taken after a pkg_add or to display licensing information. The pkg-message file does not need to be added to pkg-plist. Also, it will not get automatically printed if the user is using the port, not the package, so you should probably display it from the post-install target yourself. <filename>pkg-install</filename> If your port needs to execute commands when the binary package is installed with pkg_add you can do this via the pkg-install script. This script will automatically be added to the package, and will be run twice by pkg_add. The first time as ${SH} pkg-install ${PKGNAME} PRE-INSTALL and the second time as ${SH} pkg-install ${PKGNAME} POST-INSTALL. $2 can be tested to determine which mode the script is being run in. The PKG_PREFIX environmental variable will be set to the package installation directory. See &man.pkg.add.1; for additional information. This script is not run automatically if you install the port with make install. If you are depending on it being run, you will have to explicitly call it from your port's Makefile. <filename>pkg-req</filename> If your port needs to determine if it should install or not, you can create a pkg-req “requirements” script. It will be invoked automatically at installation/deinstallation time to determine whether or not installation/deinstallation should proceed. Changing <filename>pkg-plist</filename> based on make variables Some ports, particularly the p5- ports, need to change their pkg-plist depending on what options they are configured with (or version of perl, in the case of p5- ports). To make this easy, any instances in the pkg-plist of %%OSREL%%, %%PERL_VER%%, and %%PERL_VERSION%% will be substituted for appropriately. The value of %%OSREL%% is the numeric revision of the operating system (e.g., 2.2.7). %%PERL_VERSION%% is the full version number of perl (e.g., 5.00502) and %%PERL_VER%% is the perl version number minus the patchlevel (e.g., 5.005). If you need to make other substitutions, you can set the PLIST_SUB variable with a list of VAR=VALUE pairs and instances of %%VAR%%' will be substituted with VALUE in the pkg-plist. For instance, if you have a port that installs many files in a version-specific subdirectory, you can put something like OCTAVE_VERSION= 2.0.13 PLIST_SUB= OCTAVE_VERSION=${OCTAVE_VERSION} in the Makefile and use %%OCTAVE_VERSION%% wherever the version shows up in pkg-plist. That way, when you upgrade the port, you will not have to change dozens (or in some cases, hundreds) of lines in the pkg-plist. This substitution (as well as addition of any man pages) will be done between the do-install and post-install targets, by reading from PLIST and writing to TMPPLIST (default: WRKDIR/.PLIST.mktmp). So if your port builds PLIST on the fly, do so in or before do-install. Also, if your port needs to edit the resulting file, do so in post-install to a file named TMPPLIST. Changing the names of <filename>pkg-<replaceable>*</replaceable></filename> files All the names of pkg-* files are defined using variables so you can change them in your Makefile if need be. This is especially useful when you are sharing the same pkg-* files among several ports or have to write to one of the above files (see writing to places other than WRKDIR for why it is a bad idea to write directly in to the pkg-* subdirectory). Here is a list of variable names and their default values. (PKGDIR defaults to ${MASTERDIR}.) Variable Default value COMMENT ${PKGDIR}/pkg-comment DESCR ${PKGDIR}/pkg-descr PLIST ${PKGDIR}/pkg-plist PKGINSTALL ${PKGDIR}/pkg-install PKGDEINSTALL ${PKGDIR}/pkg-deinstall PKGREQ ${PKGDIR}/pkg-req PKGMESSAGE ${PKGDIR}/pkg-message Please change these variables rather than overriding PKG_ARGS. If you change PKG_ARGS, those files will not correctly be installed in /var/db/pkg upon install from a port. Licensing Problems Some software packages have restrictive licenses or can be in violation of the law in some countries (such as violating a patent). What we can do with them varies a lot, depending on the exact wordings of the respective licenses. It is your responsibility as a porter to read the licensing terms of the software and make sure that the FreeBSD project will not be held accountable for violating them by redistributing the source or compiled binaries either via ftp or CD-ROM. If in doubt, please contact the &a.ports;. There are two variables you can set in the Makefile to handle the situations that arise frequently: If the port has a “do not sell for profit” type of license, set the variable NO_CDROM to a string describing the reason why. We will make sure such ports will not go into the CD-ROM come release time. The distfile and package will still be available via ftp. If the resulting package needs to be built uniquely for each site, or the resulting binary package cannot be distributed due to licensing; set the variable NO_PACKAGE to a string describing the reason why. We will make sure such packages will not go on the ftp site, nor into the CD-ROM come release time. The distfile will still be included on both however. If the port has legal restrictions on who can use it (e.g., patented stuff) or has a “no commercial use” license, set the variable RESTRICTED to be the string describing the reason why. For such ports, the distfiles/packages will not be available even from our ftp sites. The GNU General Public License (GPL), both version 1 and 2, should not be a problem for ports. If you are a committer, make sure you update the ports/LEGAL file too. Upgrading When you notice that a port is out of date compared to the latest version from the original authors, first make sure you have the latest port. You can find them in the ports/ports-current directory of the ftp mirror sites. You may also use CVSup to keep your whole ports collection up-to-date, as described in the Handbook. The next step is to send a mail to the maintainer, if one is listed in the port's Makefile. That person may already be working on an upgrade, or have a reason to not upgrade the port right now (because of, for example, stability problems of the new version). If the maintainer asks you to do the upgrade or there is not any such person to begin with, please make the upgrade and send the recursive diff (either unified or context diff is fine, but port committers appear to prefer unified diff more) of the new and old ports directories to us (e.g., if your modified port directory is called superedit and the original as in our tree is superedit.bak, then send us the result of diff -ruN superedit.bak superedit). Please examine the output to make sure all the changes make sense. The best way to send us the diff is by including it via &man.send-pr.1; (category ports). Please mention any added or deleted files in the message, as they have to be explicitly specified to CVS when doing a commit. If the diff is more than about 20KB, please compress and uuencode it; otherwise, just include it in the PR as is. Once again, please use &man.diff.1; and not &man.shar.1; to send updates to existing ports! <anchor id="porting-dads">Dos and Don'ts Here is a list of common dos and don'ts that you encounter during the porting process.You should check your own port against this list, but you can also check ports in the PR database that others have submitted. Submit any comments on ports you check as described in Bug Reports and General Commentary. Checking ports in the PR database will both make it faster for us to commit them, and prove that you know what you are doing. Strip Binaries Do strip binaries. If the original source already strips the binaries, fine; otherwise you should add a - post-install rule to to it yourself. Here is an + post-install rule to it yourself. Here is an example: post-install: strip ${PREFIX}/bin/xdl Use the &man.file.1; command on the installed executable to check whether the binary is stripped or not. If it does not say not stripped, it is stripped. INSTALL_* macros Do use the macros provided in bsd.port.mk to ensure correct modes and ownership of files in your own *-install targets. INSTALL_PROGRAM is a command to install binary executables. INSTALL_SCRIPT is a command to install executable scripts. INSTALL_DATA is a command to install sharable data. INSTALL_MAN is a command to install manpages and other documentation (it does not compress anything). These are basically the install command with all the appropriate flags. See below for an example on how to use them. <makevar>WRKDIR</makevar> Do not write anything to files outside WRKDIR. WRKDIR is the only place that is guaranteed to be writable during the port build (see compiling ports from CDROM for an example of building ports from a read-only tree). If you need to modify one of the pkg-* files, do so by redefining a variable, not by writing over it. <makevar>WRKDIRPREFIX</makevar> Make sure your port honors WRKDIRPREFIX. Most ports do not have to worry about this. In particular, if you are referring to a WRKDIR of another port, note that the correct location is WRKDIRPREFIXPORTSDIR/subdir/name/work not PORTSDIR/subdir/name/work or .CURDIR/../../subdir/name/work or some such. Also, if you are defining WRKDIR yourself, make sure you prepend ${WRKDIRPREFIX}${.CURDIR} in the front. Differentiating operating systems and OS versions You may come across code that needs modifications or conditional compilation based upon what version of UNIX it is running under. If you need to make such changes to the code for conditional compilation, make sure you make the changes as general as possible so that we can back-port code to FreeBSD 1.x systems and cross-port to other BSD systems such as 4.4BSD from CSRG, BSD/386, 386BSD, NetBSD, and OpenBSD. The preferred way to tell 4.3BSD/Reno (1990) and newer versions of the BSD code apart is by using the BSD macro defined in <sys/param.h>. Hopefully that file is already included; if not, add the code: #if (defined(__unix__) || defined(unix)) && !defined(USG) #include <sys/param.h> #endif to the proper place in the .c file. We believe that every system that defines these two symbols has sys/param.h. If you find a system that does not, we would like to know. Please send mail to the &a.ports;. Another way is to use the GNU Autoconf style of doing this: #ifdef HAVE_SYS_PARAM_H #include <sys/param.h> #endif Do not forget to add -DHAVE_SYS_PARAM_H to the CFLAGS in the Makefile for this method. Once you have sys/param.h included, you may use: #if (defined(BSD) && (BSD >= 199103)) to detect if the code is being compiled on a 4.3 Net2 code base or newer (e.g. FreeBSD 1.x, 4.3/Reno, NetBSD 0.9, 386BSD, BSD/386 1.1 and below). Use: #if (defined(BSD) && (BSD >= 199306)) to detect if the code is being compiled on a 4.4 code base or newer (e.g. FreeBSD 2.x, 4.4, NetBSD 1.0, BSD/386 2.0 or above). The value of the BSD macro is 199506 for the 4.4BSD-Lite2 code base. This is stated for informational purposes only. It should not be used to distinguish between versions of FreeBSD based only on 4.4-Lite vs. versions that have merged in changes from 4.4-Lite2. The __FreeBSD__ macro should be used instead. Use sparingly: __FreeBSD__ is defined in all versions of FreeBSD. Use it if the change you are making only affects FreeBSD. Porting gotchas like the use of sys_errlist[] vs strerror() are Berkeleyisms, not FreeBSD changes. In FreeBSD 2.x, __FreeBSD__ is defined to be 2. In earlier versions, it is 1. Later versions will bump it to match their major version number. If you need to tell the difference between a FreeBSD 1.x system and a FreeBSD 2.x or 3.x system, usually the right answer is to use the BSD macros described above. If there actually is a FreeBSD specific change (such as special shared library options when using ld) then it is OK to use __FreeBSD__ and #if __FreeBSD__ > 1 to detect a FreeBSD 2.x and later system. If you need more granularity in detecting FreeBSD systems since 2.0-RELEASE you can use the following: #if __FreeBSD__ >= 2 #include <osreldate.h> # if __FreeBSD_version >= 199504 /* 2.0.5+ release specific code here */ # endif #endif Release __FreeBSD_version 2.0-RELEASE 119411 2.1-CURRENT 199501, 199503 2.0.5-RELEASE 199504 2.2-CURRENT before 2.1 199508 2.1.0-RELEASE 199511 2.2-CURRENT before 2.1.5 199512 2.1.5-RELEASE 199607 2.2-CURRENT before 2.1.6 199608 2.1.6-RELEASE 199612 2.1.7-RELEASE 199612 2.2-RELEASE 220000 2.2.1-RELEASE 220000 (no change) 2.2-STABLE after 2.2.1-RELEASE 220000 (no change) 2.2-STABLE after texinfo-3.9 221001 2.2-STABLE after top 221002 2.2.2-RELEASE 222000 2.2-STABLE after 2.2.2-RELEASE 222001 2.2.5-RELEASE 225000 2.2-STABLE after 2.2.5-RELEASE 225001 2.2-STABLE after ldconfig -R merge 225002 2.2.6-RELEASE 226000 2.2.7-RELEASE 227000 2.2-STABLE after 2.2.7-RELEASE 227001 2.2-STABLE after &man.semctl.2; change 227002 2.2.8-RELEASE 228000 2.2-STABLE after 2.2.8-RELEASE 228001 3.0-CURRENT before &man.mount.2; change 300000 3.0-CURRENT after &man.mount.2; change 300001 3.0-CURRENT after &man.semctl.2; change 300002 3.0-CURRENT after ioctl arg changes 300003 3.0-CURRENT after ELF conversion 300004 3.0-RELEASE 300005 3.0-CURRENT after 3.0-RELEASE 300006 3.0-STABLE after 3/4 branch 300007 3.1-RELEASE 310000 3.1-STABLE after 3.1-RELEASE 310001 3.1-STABLE after C++ constructor/destructor order change 310002 3.2-RELEASE 320000 3.2-STABLE 320001 3.2-STABLE after binary-incompatible IPFW and socket changes 320002 3.3-RELEASE 330000 3.3-STABLE 330001 3.3-STABLE after adding &man.mkstemp.3; to libc 330002 3.4-RELEASE 340000 3.4-STABLE 340001 4.0-CURRENT after 3.4 branch 400000 4.0-CURRENT after change in dynamic linker handling 400001 4.0-CURRENT after C++ constructor/destructor order change 400002 4.0-CURRENT after functioning &man.dladdr.3; 400003 4.0-CURRENT after __deregister_frame_info dynamic linker bug fix (also 4.0-CURRENT after EGCS 1.1.2 integration) 400004 4.0-CURRENT after &man.suser.9; API change (also 4.0-CURRENT after newbus) 400005 4.0-CURRENT after cdevsw registration change 400006 4.0-CURRENT after the addition of so_cred for socket level credentials 400007 4.0-CURRENT after the addition of a poll syscall wrapper to libc_r 400008 4.0-CURRENT after the change of the kernel's dev_t type to struct specinfo pointer 400009 4.0-CURRENT after fixing a hole in &man.jail.2; 400010 4.0-CURRENT after the sigset_t datatype change 400011 4.0-CURRENT after the cutover to the GCC 2.95.2 compiler 400012 4.0-CURRENT after adding pluggable linux-mode ioctl handlers 400013 4.0-CURRENT after importing OpenSSL 400014 4.0-CURRENT after the C++ ABI change in GCC 2.95.2 from -fvtable-thunks to -fno-vtable-thunks by default 400015 4.0-CURRENT after importing OpenSSH 400016 4.0-RELEASE 400017 4.0-STABLE after 4.0-RELEASE 400018 4.0-STABLE after merging libxpg4 code into libc. 400020 4.0-STABLE after upgrading Binutils to 2.10.0, ELF branding changes, and tcsh in the base system. 400021 4.1-RELEASE 410000 4.1-STABLE after 4.1-RELEASE 410001 4.1-STABLE after &man.setproctitle.3; moved from libutil to libc. 410002 4.1.1-RELEASE 411000 4.1.1-STABLE after 4.1.1-RELEASE 411001 4.2-RELEASE 420000 4.2-STABLE after combining libgcc.a and libgcc_r.a, and associated GCC linkage changes. 420001 5.0-CURRENT 500000 5.0-CURRENT after adding addition ELF header fields, and changing our ELF binary branding method. 500001 5.0-CURRENT after kld metadata changes. 500002 5.0-CURRENT after buf/bio changes. 500003 5.0-CURRENT after binutils upgrade. 500004 5.0-CURRENT after merging libxpg4 code into libc and after TASKQ interface introduction. 500005 5.0-CURRENT after the addition of AGP interfaces. 500006 5.0-CURRENT after Perl upgrade to 5.6.0 500007 5.0-CURRENT after the update of KAME code to 2000/07 sources. 500008 5.0-CURRENT after ether_ifattach() and ether_ifdetach() changes. 500009 5.0-CURRENT after changing mtree defaults back to original variant, adding -L to follow symlinks. 500010 5.0-CURRENT after kqueue API changed. 500011 5.0-CURRENT after &man.setproctitle.3; moved from libutil to libc. 500012 5.0-CURRENT after the first SMPng commit. 500013 5.0-CURRENT after <sys/select.h> moved to <sys/selinfo.h>. 500014 5.0-CURRENT after combining libgcc.a and libgcc_r.a, and associated GCC linkage changes. 500015 5.0-CURRENT after change allowing libc and libc_r to be linked together, deprecating -pthread option. 500016 5.0-CURRENT after switch from struct ucred to struct xucred to stabilize kernel-exported API for mountd et al. 500017 5.0-CURRENT after addition of CPUTYPE make variable for controlling CPU-specific optimizations. 500018 5.0-CURRENT after moving machine/ioctl_fd.h to sys/fdcio.h 500019 5.0-CURRENT after locale names renaming. 500020 5.0-CURRENT after Bzip2 import. 500021 Note that 2.2-STABLE sometimes identifies itself as “2.2.5-STABLE” after the 2.2.5-RELEASE. The pattern used to be year followed by the month, but we decided to change it to a more straightforward major/minor system starting from 2.2. This is because the parallel development on several branches made it infeasible to classify the releases simply by their real release dates. If you are making a port now, you do not have to worry about old -CURRENTs; they are listed here just for your reference. In the hundreds of ports that have been done, there have only been one or two cases where __FreeBSD__ should have been used. Just because an earlier port screwed up and used it in the wrong place does not mean you should do so too. Writing something after <filename>bsd.port.mk</filename> Do not write anything after the .include <bsd.port.mk> line. It usually can be avoided by including bsd.port.pre.mk somewhere in the middle of your Makefile and bsd.port.post.mk at the end. You need to include either the pre.mk/post.mk pair or bsd.port.mk only; do not mix these two. bsd.port.pre.mk only defines a few variables, which can be used in tests in the Makefile, bsd.port.post.mk defines the rest. Here are some important variables defined in bsd.port.pre.mk (this is not the complete list, please read bsd.port.mk for the complete list). Variable Description ARCH The architecture as returned by uname -m (e.g., i386) OPSYS The operating system type, as returned by uname -s (e.g., FreeBSD) OSREL The release version of the operating system (e.g., 2.1.5 or 2.2.7) OSVERSION The numeric version of the operating system, same as __FreeBSD_version. PORTOBJFORMAT The object format of the system (aout or elf) LOCALBASE The base of the “local” tree (e.g., /usr/local/) X11BASE The base of the “X11” tree (e.g., /usr/X11R6) PREFIX Where the port installs itself (see more on PREFIX). If you have to define the variables USE_IMAKE, USE_X_PREFIX, or MASTERDIR, do so before including bsd.port.pre.mk. Here are some examples of things you can write after bsd.port.pre.mk: # no need to compile lang/perl5 if perl5 is already in system .if ${OSVERSION} > 300003 BROKEN= perl is in system .endif # only one shlib version number for ELF .if ${PORTOBJFORMAT} == "elf" TCL_LIB_FILE= ${TCL_LIB}.${SHLIB_MAJOR} .else TCL_LIB_FILE= ${TCL_LIB}.${SHLIB_MAJOR}.${SHLIB_MINOR} .endif # software already makes link for ELF, but not for a.out post-install: .if ${PORTOBJFORMAT} == "aout" ${LN} -sf liblinpack.so.1.0 ${PREFIX}/lib/liblinpack.so .endif Install additional documentation If your software has some documentation other than the standard man and info pages that you think is useful for the user, install it under PREFIX/share/doc. This can be done, like the previous item, in the post-install target. Create a new directory for your port. The directory name should reflect what the port is. This usually means PORTNAME. However, if you think the user might want different versions of the port to be installed at the same time, you can use the whole PKGNAME. Make the installation dependent to the variable NOPORTDOCS so that users can disable it in /etc/make.conf, like this: post-install: .if !defined(NOPORTDOCS) ${MKDIR} ${PREFIX}/share/doc/xv ${INSTALL_MAN} ${WRKSRC}/docs/xvdocs.ps ${PREFIX}/share/doc/xv .endif Do not forget to add them to pkg-plist too. (Do not worry about NOPORTDOCS here; there is currently no way for the packages to read variables from /etc/make.conf.) You can also use the pkg-message file to display messages upon installation. See the using pkg-message section for details. pkg-message does not need to be added to pkg-plist. <makevar>DIST_SUBDIR</makevar> Do not let your port clutter /usr/ports/distfiles. If your port requires a lot of files to be fetched, or contains a file that has a name that might conflict with other ports (e.g., Makefile), set DIST_SUBDIR to the name of the port (${PORTNAME} or ${PKGNAMEPREFIX}${PORTNAME} should work fine). This will change DISTDIR from the default /usr/ports/distfiles to /usr/ports/distfiles/DIST_SUBDIR, and in effect puts everything that is required for your port into that subdirectory. It will also look at the subdirectory with the same name on the backup master site at ftp.FreeBSD.org. (Setting DISTDIR explicitly in your Makefile will not accomplish this, so please use DIST_SUBDIR.) This does not affect the MASTER_SITES you define in your Makefile. Package information Do include package information, i.e. pkg-comment, pkg-descr, and pkg-plist. Note that these files are not used only for packaging anymore, and are mandatory now, even if NO_PACKAGE is set. RCS strings Do not put RCS strings in patches. CVS will mangle them when we put the files into the ports tree, and when we check them out again, they will come out different and the patch will fail. RCS strings are surrounded by dollar ($) signs, and typically start with $Id or $RCS. Recursive diff Using the recurse () option to diff to generate patches is fine, but please take a look at the resulting patches to make sure you do not have any unnecessary junk in there. In particular, diffs between two backup files, Makefiles when the port uses Imake or GNU configure, etc., are unnecessary and should be deleted. If you had to edit configure.in and run autoconf to regenerate configure, do not take the diffs of configure (it often grows to a few thousand lines!); define USE_AUTOCONF=yes and take the diffs of configure.in. Also, if you had to delete a file, then you can do it in the post-extract target rather than as part of the patch. Once you are happy with the resulting diff, please split it up into one source file per patch file. <makevar>PREFIX</makevar> Do try to make your port install relative to PREFIX. (The value of this variable will be set to LOCALBASE (default /usr/local), unless USE_X_PREFIX or USE_IMAKE is set, in which case it will be X11BASE (default /usr/X11R6).) Not hard-coding /usr/local or /usr/X11R6 anywhere in the source will make the port much more flexible and able to cater to the needs of other sites. For X ports that use imake, this is automatic; otherwise, this can often be done by simply replacing the occurrences of /usr/local (or /usr/X11R6 for X ports that do not use imake) in the various scripts/Makefiles in the port to read PREFIX, as this variable is automatically passed down to every stage of the build and install processes. Make sure your application isn't installing things in /usr/local instead of PREFIX. A quick test for this is to do this is: &prompt.root; make clean; make package PREFIX=/var/tmp/port-name If anything is installed outside of PREFIX, making the package creation process will complain that it can't find the files. + This does not test for the existence of internal references, or correct use of LOCALBASE for references to files from other ports. Testing the installation in /var/tmp/port-name to do that that while you have it installed would do that. Do not set USE_X_PREFIX unless your port truly requires it (i.e., it links against X libs or it needs to reference files in X11BASE). The variable PREFIX can be reassigned in your Makefile or in the user's environment. However, it is strongly discouraged for individual ports to set this variable explicitly in the Makefiles. Also, refer to programs/files from other ports with the variables mentioned above, not explicit pathnames. For instance, if your port requires a macro PAGER to be the full pathname of less, use the compiler flag: -DPAGER=\"${PREFIX}/bin/less\" or -DPAGER=\"${LOCALBASE}/bin/less\" if this is an X port, instead of -DPAGER=\"/usr/local/bin/less\". This way it will have a better chance of working if the system administrator has moved the whole `/usr/local' tree somewhere else. Subdirectories Try to let the port put things in the right subdirectories of PREFIX. Some ports lump everything and put it in the subdirectory with the port's name, which is incorrect. Also, many ports put everything except binaries, header files and manual pages in the a subdirectory of lib, which does not bode well with the BSD paradigm. Many of the files should be moved to one of the following: etc (setup/configuration files), libexec (executables started internally), sbin (executables for superusers/managers), info (documentation for info browser) or share (architecture independent files). See man &man.hier.7; for details, the rules governing /usr pretty much apply to /usr/local too. The exception are ports dealing with USENET “news”. They may use PREFIX/news as a destination for their files. Cleaning up empty directories Do make your ports clean up after themselves when they are deinstalled. This is usually accomplished by adding @dirrm lines for all directories that are specifically created by the port. You need to delete subdirectories before you can delete parent directories. : lib/X11/oneko/pixmaps/cat.xpm lib/X11/oneko/sounds/cat.au : @dirrm lib/X11/oneko/pixmaps @dirrm lib/X11/oneko/sounds @dirrm lib/X11/oneko However, sometimes @dirrm will give you errors because other ports also share the same subdirectory. You can call rmdir from @unexec to remove only empty directories without warning. @unexec rmdir %D/share/doc/gimp 2>/dev/null || true This will neither print any error messages nor cause pkg_delete to exit abnormally even if PREFIX/share/doc/gimp is not empty due to other ports installing some files in there. UIDs If your port requires a certain user to be on the installed system, let the pkg-install script call pw to create it automatically. Look at net/cvsup-mirror for an example. If your port must use the same user/group ID number when it is installed as a binary package as when it was compiled, then you must choose a free UID from 50 to 99 and register it below. Look at japanese/Wnn for an example. Make sure you do not use a UID already used by the system or other ports. This is the current list of UIDs between 50 and 99. majordom:*:54:54:Majordomo Pseudo User:/usr/local/majordomo:/nonexistent cyrus:*:60:60:the cyrus mail server:/nonexistent:/nonexistent gnats:*:61:1:GNATS database owner:/usr/local/share/gnats/gnats-db:/bin/sh uucp:*:66:66:UUCP pseudo-user:/var/spool/uucppublic:/usr/libexec/uucp/uucico xten:*:67:67:X-10 daemon:/usr/local/xten:/nonexistent pop:*:68:6:Post Office Owner (popper):/nonexistent:/nonexistent wnn:*:69:7:Wnn:/nonexistent:/nonexistent ifmail:*:70:66:Ifmail user:/nonexistent:/nonexistent pgsql:*:70:70:PostgreSQL pseudo-user:/usr/local/pgsql:/bin/sh ircd:*:72:72:IRCd hybrid:/nonexistent:/nonexistent alias:*:81:81:QMail user:/var/qmail/alias:/nonexistent qmaill:*:83:81:QMail user:/var/qmail:/nonexistent qmaild:*:82:81:QMail user:/var/qmail:/nonexistent qmailq:*:85:82:QMail user:/var/qmail:/nonexistent qmails:*:87:82:QMail user:/var/qmail:/nonexistent qmailp:*:84:81:QMail user:/var/qmail:/nonexistent qmailr:*:86:82:QMail user:/var/qmail:/nonexistent msql:*:87:87:mSQL-2 pseudo-user:/var/db/msqldb:/bin/sh mysql:*:88:88:MySQL Daemon:/var/db/mysql:/sbin/nologin vpopmail:*:89:89::0:0:User &:/usr/local/vpopmail:/nonexistent Please include a notice when you submit a port (or an upgrade) that reserves a new UID or GID in this range. This allows us to keep the list of reserved IDs up to date. Do things rationally The Makefile should do things simply and reasonably. If you can make it a couple of lines shorter or more readable, then do so. Examples include using a make .if construct instead of a shell if construct, not redefining do-extract if you can redefine EXTRACT* instead, and using GNU_CONFIGURE instead of CONFIGURE_ARGS += --prefix=${PREFIX}. Respect <makevar>CFLAGS</makevar> The port should respect the CFLAGS variable. If it does not, please add NO_PACKAGE=ignores cflags to the Makefile. An example of a Makefile respecting the CFLAGS variable follows. Note the +=: CFLAGS += -Wall -Werror Here is an example which does not respect the CFLAGS variable: CFLAGS = -Wall -Werror The CFLAGS variable is defined on FreeBSD systems in /etc/make.conf. The first example appends additional flags to the CFLAGS variable, preserving any system-wide definitions. The second example clobbers anything previously defined. Configuration files If your port requires some configuration files in PREFIX/etc, do not just install them and list them in pkg-plist. That will cause pkg_delete to delete files carefully edited by the user and a new installation to wipe them out. Instead, install sample files with a suffix (filename.sample will work well) and print out a message pointing out that the user has to copy and edit the file before the software can be made to work. Portlint Do check your work with portlint before you submit or commit it. Feedback Do send applicable changes/patches to the original author/maintainer for inclusion in next release of the code. This will only make your job that much easier for the next release. <filename>README.html</filename> Do not include the README.html file. This file is not part of the cvs collection but is generated using the make readme command. Miscellanea The files pkg-comment, pkg-descr, and pkg-plist should each be double-checked. If you are reviewing a port and feel they can be worded better, do so. Do not copy more copies of the GNU General Public License into our system, please. Please be careful to note any legal issues! Do not let us illegally distribute software! If you are stuck… Do look at existing examples and the bsd.port.mk file before asking us questions! ;-) Do ask us questions if you have any trouble! Do not just beat your head against a wall! :-) A Sample <filename>Makefile</filename> Here is a sample Makefile that you can use to create a new port. Make sure you remove all the extra comments (ones between brackets)! It is recommended that you follow this format (ordering of variables, empty lines between sections, etc.). This format is designed so that the most important information is easy to locate. We recommend that you use portlint to check the Makefile. [the header...just to make it easier for us to identify the ports.] # New ports collection makefile for: xdvi [the "version required" line is only needed when the PORTVERSION variable is not specific enough to describe the port.] # Date created: 26 May 1995 [this is the person who did the original port to FreeBSD, in particular, the person who wrote the first version of this Makefile. Remember, this should not be changed when upgrading the port later.] # Whom: Satoshi Asami <asami@FreeBSD.org> # # $FreeBSD$ [ ^^^^^^^^^ This will be automatically replaced with RCS ID string by CVS when it is committed to our repository. If upgrading a port, do not alter this line back to "$FreeBSD$". CVS deals with it automatically.] # [section to describe the port itself and the master site - PORTNAME and PORTVERSION are always first, followed by CATEGORIES, and then MASTER_SITES, which can be followed by MASTER_SITE_SUBDIR. PKGNAMEPREFIX and PKGNAMESUFFIX, if needed, will be after that. Then comes DISTNAME, EXTRACT_SUFX and/or DISTFILES, and then EXTRACT_ONLY, as necessary.] PORTNAME= xdvi PORTVERSION= 18.2 CATEGORIES= print [do not forget the trailing slash ("/")! if you are not using MASTER_SITE_* macros] MASTER_SITES= ${MASTER_SITE_XCONTRIB} MASTER_SITE_SUBDIR= applications PKGNAMEPREFIX= ja- DISTNAME= xdvi-pl18 [set this if the source is not in the standard ".tar.gz" form] EXTRACT_SUFX= .tar.Z [section for distributed patches -- can be empty] PATCH_SITES= ftp://ftp.sra.co.jp/pub/X11/japanese/ PATCHFILES= xdvi-18.patch1.gz xdvi-18.patch2.gz [maintainer; *mandatory*! This is the person (preferably with commit privileges) whom a user can contact for questions and bug reports - this person should be the porter or someone who can forward questions to the original porter reasonably promptly. If you really do not want to have your address here, set it to "ports@FreeBSD.org".] MAINTAINER= asami@FreeBSD.org [dependencies -- can be empty] RUN_DEPENDS= gs:${PORTSDIR}/print/ghostscript LIB_DEPENDS= Xpm.5:${PORTSDIR}/graphics/xpm [this section is for other standard bsd.port.mk variables that do not belong to any of the above] [If it asks questions during configure, build, install...] IS_INTERACTIVE= yes [If it extracts to a directory other than ${DISTNAME}...] WRKSRC= ${WRKDIR}/xdvi-new [If the distributed patches were not made relative to ${WRKSRC}, you may need to tweak this] PATCH_DIST_STRIP= -p1 [If it requires a "configure" script generated by GNU autoconf to be run] GNU_CONFIGURE= yes [If it requires GNU make, not /usr/bin/make, to build...] USE_GMAKE= yes [If it is an X application and requires "xmkmf -a" to be run...] USE_IMAKE= yes [et cetera.] [non-standard variables to be used in the rules below] MY_FAVORITE_RESPONSE= "yeah, right" [then the special rules, in the order they are called] pre-fetch: i go fetch something, yeah post-patch: i need to do something after patch, great pre-install: and then some more stuff before installing, wow [and then the epilogue] .include <bsd.port.mk> Automated package list creation First, make sure your port is almost complete, with only pkg-plist missing. Create an empty pkg-plist. &prompt.root; touch pkg-plist Next, create a new set of directories which your port can be installed, and install any dependencies. &prompt.root; mtree -U -f /etc/mtree/BSD.local.dist -d -e -p /var/tmp/port-name &prompt.root; make depends PREFIX=/var/tmp/port-name Store the directory structure in a new file. &prompt.root; (cd /var/tmp/port-name && find * -type d) > OLD-DIRS If your port honors PREFIX (which it should) you can then install the port and create the package list. &prompt.root; make install PREFIX=/var/tmp/port-name &prompt.root; (cd /var/tmp/port-name && find * \! -type d) > pkg-plist You must also add any newly created directories to the packing list. &prompt.root; (cd /var/tmp/port-name && find * -type d) | comm -13 OLD-DIRS - | sed -e 's#^#@dirrm #' >> pkg-plist Finally, you need to tidy up the packing list by hand; it isn't all automated. Manual pages should be listed in the port's Makefile under MANn, and not in the package list. User configuration files should be removed, or installed as filename.sample. The info/dir file should not be listed and appropriate install-info lines should be added as noted in the info files section. Any libraries installed by the port should be listed as specified in the shared libraries section. Package Names The following are the conventions you should follow in naming your packages. This is to have our package directory easy to scan, as there are already lots and lots of packages and users are going to turn away if they hurt their eyes! The package name should look like language_region-name-compiled.specifics-version.numbers. The package name is defined as ${PKGNAMEPREFIX}${PORTNAME}${PKGNAMESUFFIX}-${PORTVERSION}. Make sure to set the variables to conform to that format. FreeBSD strives to support the native language of its users. The language- part should be a two letter abbreviation of the natural language defined by ISO-639 if the port is specific to a certain language. Examples are ja for Japanese, ru for Russian, vi for Vietnamese, zh for Chinese, ko for Korean and de for German. If the port is specific to a certain region within the language area, add the two letter country code as well. Examples are en_US for US English and fr_CH for Swiss French. The language- part should be set in the PKGNAMEPREFIX variable. The first letter of name part should be lowercase. (The rest of the name can contain capital letters, so use your own discretion when you are converting a software name that has some capital letters in it.) There is a tradition of naming Perl 5 modules by prepending p5- and converting the double-colon separator to a hyphen; for example, the Data::Dumper module becomes p5-Data-Dumper. If the software in question has numbers, hyphens, or underscores in its name, you may include them as well (like kinput2). If the port can be built with different hardcoded defaults (usually part of the directory name in a family of ports), the -compiled.specifics part should state the compiled-in defaults (the hyphen is optional). Examples are papersize and font units. The compiled.specifics part should be set in the PKGNAMESUFFIX variable. The version string should follow a dash (-) and be a period-separated list of integers and single lowercase alphabetics. In particular, it is not permissible to have another dash inside the version string. The only exception is the string pl (meaning `patchlevel'), which can be used only when there are no major and minor version numbers in the software. If the software version has strings like "alpha", "beta", "rc", or "pre", take the first letter and put it immediately after a period. If the version string continues after those names, the numbers should follow the single alphabet without an extra period between them. The idea is to make it easier to sort ports by looking at the version string. In particular, make sure version number components are always delimited by a period, and if the date is part of the string, use the yyyy.mm.dd format, not dd.mm.yyyy or the non-Y2K compliant yy.mm.dd format. Here are some (real) examples on how to convert the name as called by the software authors to a suitable package name: Distribution Name PKGNAMEPREFIX PORTNAME PKGNAMESUFFIX PORTVERSION Reason mule-2.2.2 (empty) mule (empty) 2.2.2 No changes required XFree86-3.3.6 (empty) XFree86 (empty) 3.3.6 No changes required EmiClock-1.0.2 (empty) emiclock (empty) 1.0.2 No uppercase names for single programs rdist-1.3alpha (empty) rdist (empty) 1.3.a No strings like alpha allowed es-0.9-beta1 (empty) es (empty) 0.9.b1 No strings like beta allowed mailman-2.0rc3 (empty) mailman (empty) 2.0.r3 No strings like rc allowed v3.3beta021.src (empty) tiff (empty) 3.3 What the heck was that anyway? tvtwm (empty) tvtwm (empty) pl11 Version string always required piewm (empty) piewm (empty) 1.0 Version string always required xvgr-2.10pl1 (empty) xvgr (empty) 2.10.1 pl allowed only when no major/minor version numbers gawk-2.15.6 ja- gawk (empty) 2.15.6 Japanese language version psutils-1.13 (empty) psutils -letter 1.13 Papersize hardcoded at package build time pkfonts (empty) pkfonts 300 1.0 Package for 300dpi fonts If there is absolutely no trace of version information in the original source and it is unlikely that the original author will ever release another version, just set the version string to 1.0 (like the piewm example above). Otherwise, ask the original author or use the date string (yyyy.mm.dd) as the version. Categories As you already know, ports are classified in several categories. But for this to work, it is important that porters and users understand what each category is for and how we decide what to put in each category. Current list of categories First, this is the current list of port categories. Those marked with an asterisk (*) are virtual categories—those that do not have a corresponding subdirectory in the ports tree. For non-virtual categories, you will find a one-line description in the pkg/COMMENT file in that subdirectory (e.g., archivers/pkg/COMMENT). Category Description afterstep* Ports to support the AfterStep window manager. archivers Archiving tools. astro Astronomical ports. audio Sound support. benchmarks Benchmarking utilities. biology Biology-related software. cad Computer aided design tools. chinese Chinese language support. comms Communication software. Mostly software to talk to your serial port. converters Character code converters. databases Databases. deskutils Things that used to be on the desktop before computers were invented. devel Development utilities. Do not put libraries here just because they are libraries—unless they truly do not belong anywhere else, they should not be in this category. editors General editors. Specialized editors go in the section for those tools (e.g., a mathematical-formula editor will go in math). elisp* Emacs-lisp ports. emulators Emulators for other operating systems. Terminal emulators do not belong here—X-based ones should go to x11 and text-based ones to either comms or misc, depending on the exact functionality. french French language support. ftp FTP client and server utilities. If your port speaks both FTP and HTTP, put it in ftp with a secondary category of www. games Games. german German language support. gnome* Ports from the GNU Object Model Environment (GNOME) Project. graphics Graphics utilities. hebrew Hebrew language support. irc Internet Relay Chat utilities. ipv6* IPv6 related software. japanese Japanese language support. java Java language support. kde* Ports from the K Desktop Environment (KDE) Project. korean Korean language support. lang Programming languages. linux* Linux applications and support utilities. mail Mail software. math Numerical computation software and other utilities for mathematics. mbone MBone applications. misc Miscellaneous utilities—basically things that do not belong anywhere else. This is the only category that should not appear with any other non-virtual category. If you have misc with something else in your CATEGORIES line, that means you can safely delete misc and just put the port in that other subdirectory! net Miscellaneous networking software. news USENET news software. offix* Ports from the OffiX suite. palm Software support for the 3Com Palm(tm) series. perl5* Ports that require perl version 5 to run. picobsd Ports to support PicoBSD. plan9* Various programs from Plan9. print Printing software. Desktop publishing tools (previewers, etc.) belong here too. python* Software written in python. ruby* Software written in ruby. russian Russian language support. science Scientific ports that don't fit into other categories such as astro, biology and math. security Security utilities. shells Command line shells. sysutils System utilities. tcl76* Ports that use Tcl version 7.6 to run. tcl80* Ports that use Tcl version 8.0 to run. tcl81* Ports that use Tcl version 8.1 to run. tcl82* Ports that use Tcl version 8.2 to run. textproc Text processing utilities. It does not include desktop publishing tools, which go to print/. tk42* Ports that use Tk version 4.2 to run. tk80* Ports that use Tk version 8.0 to run. tk81* Ports that use Tk version 8.1 to run. tk82* Ports that use Tk version 8.2 to run. tkstep80* Ports that use TkSTEP version 8.0 to run. ukrainian Ukrainian language support. vietnamese Vietnamese language support. windowmaker* Ports to support the WindowMaker window manager www Software related to the World Wide Web. HTML language support belongs here too. x11 The X window system and friends. This category is only for software that directly supports the window system. Do not put regular X applications here. If your port is an X application, define USE_XLIB (implied by USE_IMAKE) and put it in the appropriate categories. Also, many of them go into other x11-* categories (see below). x11-clocks X11 clocks. x11-fm X11 file managers. x11-fonts X11 fonts and font utilities. x11-servers X11 servers. x11-toolkits X11 toolkits. x11-wm X11 window managers. zope* Zope support. Choosing the right category As many of the categories overlap, you often have to choose which of the categories should be the primary category of your port. There are several rules that govern this issue. Here is the list of priorities, in decreasing order of precedence. Language specific categories always come first. For example, if your port installs Japanese X11 fonts, then your CATEGORIES line would read japanese x11-fonts. Specific categories win over less-specific ones. For instance, an HTML editor should be listed as www editors, not the other way around. Also, you do not need to list net when the port belongs to any of irc, mail, mbone, news, security, or www. x11 is used as a secondary category only when the primary category is a natural language. In particular, you should not put x11 in the category line for X applications. Emacs modes should be placed in the same ports category as the application supported by the mode, not in editors. For example, an Emacs mode to edit source files of some programming language should go into lang. If your port truly does not belong anywhere else, put it in misc. If you are not sure about the category, please put a comment to that effect in your send-pr submission so we can discuss it before we import it. If you are a committer, send a note to the &a.ports; so we can discuss it first—too often new ports are imported to the wrong category only to be moved right away. Changes to this document and the ports system If you maintain a lot of ports, you should consider following the &a.ports;. Important changes to the way ports work will be announced there. You can always find more detailed information on the latest changes by looking at the bsd.port.mk CVS log. That is It, Folks! Boy, this sure was a long tutorial, wasn't it? Thanks for following us to here, really. Now that you know how to do a port, have at it and convert everything in the world into ports! That is the easiest way to start contributing to the FreeBSD Project! :-)