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diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 4014006ce2e5..73ac2c6efc4e 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1,5105 +1,5108 @@
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1988, 1990, 1993
* The Regents of the University of California.
* Copyright (c) 2004 The FreeBSD Foundation
* Copyright (c) 2004-2008 Robert N. M. Watson
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
/*
* Comments on the socket life cycle:
*
* soalloc() sets of socket layer state for a socket, called only by
* socreate() and sonewconn(). Socket layer private.
*
* sodealloc() tears down socket layer state for a socket, called only by
* sofree() and sonewconn(). Socket layer private.
*
* pr_attach() associates protocol layer state with an allocated socket;
* called only once, may fail, aborting socket allocation. This is called
* from socreate() and sonewconn(). Socket layer private.
*
* pr_detach() disassociates protocol layer state from an attached socket,
* and will be called exactly once for sockets in which pr_attach() has
* been successfully called. If pr_attach() returned an error,
* pr_detach() will not be called. Socket layer private.
*
* pr_abort() and pr_close() notify the protocol layer that the last
* consumer of a socket is starting to tear down the socket, and that the
* protocol should terminate the connection. Historically, pr_abort() also
* detached protocol state from the socket state, but this is no longer the
* case. pr_fdclose() is called when userspace invokes close(2) on a socket
* file descriptor.
*
* socreate() creates a socket and attaches protocol state. This is a public
* interface that may be used by socket layer consumers to create new
* sockets.
*
* sonewconn() creates a socket and attaches protocol state. This is a
* public interface that may be used by protocols to create new sockets when
* a new connection is received and will be available for accept() on a
* listen socket.
*
* soclose() destroys a socket after possibly waiting for it to disconnect.
* This is a public interface that socket consumers should use to close and
* release a socket when done with it.
*
* soabort() destroys a socket without waiting for it to disconnect (used
* only for incoming connections that are already partially or fully
* connected). This is used internally by the socket layer when clearing
* listen socket queues (due to overflow or close on the listen socket), but
* is also a public interface protocols may use to abort connections in
* their incomplete listen queues should they no longer be required. Sockets
* placed in completed connection listen queues should not be aborted for
* reasons described in the comment above the soclose() implementation. This
* is not a general purpose close routine, and except in the specific
* circumstances described here, should not be used.
*
* sofree() will free a socket and its protocol state if all references on
* the socket have been released, and is the public interface to attempt to
* free a socket when a reference is removed. This is a socket layer private
* interface.
*
* NOTE: In addition to socreate() and soclose(), which provide a single
* socket reference to the consumer to be managed as required, there are two
* calls to explicitly manage socket references, soref(), and sorele().
* Currently, these are generally required only when transitioning a socket
* from a listen queue to a file descriptor, in order to prevent garbage
* collection of the socket at an untimely moment. For a number of reasons,
* these interfaces are not preferred, and should be avoided.
*
* NOTE: With regard to VNETs the general rule is that callers do not set
* curvnet. Exceptions to this rule include soabort(), sodisconnect(),
* sofree(), sorele(), sonewconn() and sorflush(), which are usually called
* from a pre-set VNET context. sopoll_generic() currently does not need a
* VNET context to be set.
*/
#include <sys/cdefs.h>
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_kern_tls.h"
#include "opt_ktrace.h"
#include "opt_sctp.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/fcntl.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/domain.h>
#include <sys/file.h> /* for struct knote */
#include <sys/hhook.h>
#include <sys/kernel.h>
#include <sys/khelp.h>
#include <sys/kthread.h>
#include <sys/ktls.h>
#include <sys/event.h>
#include <sys/eventhandler.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/sbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/resourcevar.h>
#include <net/route.h>
#include <sys/sched.h>
#include <sys/signalvar.h>
#include <sys/smp.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/jail.h>
#include <sys/syslog.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp.h>
#include <net/vnet.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <vm/uma.h>
#ifdef COMPAT_FREEBSD32
#include <sys/mount.h>
#include <sys/sysent.h>
#include <compat/freebsd32/freebsd32.h>
#endif
static int soreceive_generic_locked(struct socket *so,
struct sockaddr **psa, struct uio *uio, struct mbuf **mp,
struct mbuf **controlp, int *flagsp);
static int soreceive_rcvoob(struct socket *so, struct uio *uio,
int flags);
static int soreceive_stream_locked(struct socket *so, struct sockbuf *sb,
struct sockaddr **psa, struct uio *uio, struct mbuf **mp,
struct mbuf **controlp, int flags);
static int sosend_generic_locked(struct socket *so, struct sockaddr *addr,
struct uio *uio, struct mbuf *top, struct mbuf *control,
int flags, struct thread *td);
static void so_rdknl_lock(void *);
static void so_rdknl_unlock(void *);
static void so_rdknl_assert_lock(void *, int);
static void so_wrknl_lock(void *);
static void so_wrknl_unlock(void *);
static void so_wrknl_assert_lock(void *, int);
static void filt_sordetach(struct knote *kn);
static int filt_soread(struct knote *kn, long hint);
static void filt_sowdetach(struct knote *kn);
static int filt_sowrite(struct knote *kn, long hint);
static int filt_soempty(struct knote *kn, long hint);
static const struct filterops soread_filtops = {
.f_isfd = 1,
.f_detach = filt_sordetach,
.f_event = filt_soread,
.f_copy = knote_triv_copy,
};
static const struct filterops sowrite_filtops = {
.f_isfd = 1,
.f_detach = filt_sowdetach,
.f_event = filt_sowrite,
.f_copy = knote_triv_copy,
};
static const struct filterops soempty_filtops = {
.f_isfd = 1,
.f_detach = filt_sowdetach,
.f_event = filt_soempty,
.f_copy = knote_triv_copy,
};
so_gen_t so_gencnt; /* generation count for sockets */
MALLOC_DEFINE(M_SONAME, "soname", "socket name");
MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
#define VNET_SO_ASSERT(so) \
VNET_ASSERT(curvnet != NULL, \
("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
#ifdef SOCKET_HHOOK
VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
#define V_socket_hhh VNET(socket_hhh)
static inline int hhook_run_socket(struct socket *, void *, int32_t);
#endif
#ifdef COMPAT_FREEBSD32
#ifdef __amd64__
/* off_t has 4-byte alignment on i386 but not on other 32-bit platforms. */
#define __splice32_packed __packed
#else
#define __splice32_packed
#endif
struct splice32 {
int32_t sp_fd;
int64_t sp_max;
struct timeval32 sp_idle;
} __splice32_packed;
#undef __splice32_packed
#endif
/*
* Limit on the number of connections in the listen queue waiting
* for accept(2).
* NB: The original sysctl somaxconn is still available but hidden
* to prevent confusion about the actual purpose of this number.
*/
VNET_DEFINE_STATIC(u_int, somaxconn) = SOMAXCONN;
#define V_somaxconn VNET(somaxconn)
static int
sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
{
int error;
u_int val;
val = V_somaxconn;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr )
return (error);
/*
* The purpose of the UINT_MAX / 3 limit, is so that the formula
* 3 * sol_qlimit / 2
* below, will not overflow.
*/
if (val < 1 || val > UINT_MAX / 3)
return (EINVAL);
V_somaxconn = val;
return (0);
}
SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue,
CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE | CTLFLAG_VNET, 0, sizeof(u_int),
sysctl_somaxconn, "IU",
"Maximum listen socket pending connection accept queue size");
SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE | CTLFLAG_VNET, 0,
sizeof(u_int), sysctl_somaxconn, "IU",
"Maximum listen socket pending connection accept queue size (compat)");
static u_int numopensockets;
static int
sysctl_numopensockets(SYSCTL_HANDLER_ARGS)
{
u_int val;
#ifdef VIMAGE
if(!IS_DEFAULT_VNET(curvnet))
val = curvnet->vnet_sockcnt;
else
#endif
val = numopensockets;
return (sysctl_handle_int(oidp, &val, 0, req));
}
SYSCTL_PROC(_kern_ipc, OID_AUTO, numopensockets,
CTLTYPE_UINT | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_VNET, 0, sizeof(u_int),
sysctl_numopensockets, "IU", "Number of open sockets");
/*
* so_global_mtx protects so_gencnt, numopensockets, and the per-socket
* so_gencnt field.
*/
static struct mtx so_global_mtx;
MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
/*
* General IPC sysctl name space, used by sockets and a variety of other IPC
* types.
*/
SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"IPC");
/*
* Initialize the socket subsystem and set up the socket
* memory allocator.
*/
static uma_zone_t socket_zone;
int maxsockets;
static void
socket_zone_change(void *tag)
{
maxsockets = uma_zone_set_max(socket_zone, maxsockets);
}
static int splice_init_state;
static struct sx splice_init_lock;
SX_SYSINIT(splice_init_lock, &splice_init_lock, "splice_init");
static SYSCTL_NODE(_kern_ipc, OID_AUTO, splice, CTLFLAG_RW, 0,
"Settings relating to the SO_SPLICE socket option");
static bool splice_receive_stream = true;
SYSCTL_BOOL(_kern_ipc_splice, OID_AUTO, receive_stream, CTLFLAG_RWTUN,
&splice_receive_stream, 0,
"Use soreceive_stream() for stream splices");
static uma_zone_t splice_zone;
static struct proc *splice_proc;
struct splice_wq {
struct mtx mtx;
STAILQ_HEAD(, so_splice) head;
bool running;
} __aligned(CACHE_LINE_SIZE);
static struct splice_wq *splice_wq;
static uint32_t splice_index = 0;
static void so_splice_timeout(void *arg, int pending);
static void so_splice_xfer(struct so_splice *s);
static int so_unsplice(struct socket *so, bool timeout);
static void
splice_work_thread(void *ctx)
{
struct splice_wq *wq = ctx;
struct so_splice *s, *s_temp;
STAILQ_HEAD(, so_splice) local_head;
int cpu;
cpu = wq - splice_wq;
if (bootverbose)
printf("starting so_splice worker thread for CPU %d\n", cpu);
for (;;) {
mtx_lock(&wq->mtx);
while (STAILQ_EMPTY(&wq->head)) {
wq->running = false;
mtx_sleep(wq, &wq->mtx, 0, "-", 0);
wq->running = true;
}
STAILQ_INIT(&local_head);
STAILQ_CONCAT(&local_head, &wq->head);
STAILQ_INIT(&wq->head);
mtx_unlock(&wq->mtx);
STAILQ_FOREACH_SAFE(s, &local_head, next, s_temp) {
mtx_lock(&s->mtx);
CURVNET_SET(s->src->so_vnet);
so_splice_xfer(s);
CURVNET_RESTORE();
}
}
}
static void
so_splice_dispatch_async(struct so_splice *sp)
{
struct splice_wq *wq;
bool running;
wq = &splice_wq[sp->wq_index];
mtx_lock(&wq->mtx);
STAILQ_INSERT_TAIL(&wq->head, sp, next);
running = wq->running;
mtx_unlock(&wq->mtx);
if (!running)
wakeup(wq);
}
void
so_splice_dispatch(struct so_splice *sp)
{
mtx_assert(&sp->mtx, MA_OWNED);
if (sp->state != SPLICE_IDLE) {
mtx_unlock(&sp->mtx);
} else {
sp->state = SPLICE_QUEUED;
mtx_unlock(&sp->mtx);
so_splice_dispatch_async(sp);
}
}
static int
splice_zinit(void *mem, int size __unused, int flags __unused)
{
struct so_splice *s;
s = (struct so_splice *)mem;
mtx_init(&s->mtx, "so_splice", NULL, MTX_DEF);
return (0);
}
static void
splice_zfini(void *mem, int size)
{
struct so_splice *s;
s = (struct so_splice *)mem;
mtx_destroy(&s->mtx);
}
static int
splice_init(void)
{
struct thread *td;
int error, i, state;
state = atomic_load_acq_int(&splice_init_state);
if (__predict_true(state > 0))
return (0);
if (state < 0)
return (ENXIO);
sx_xlock(&splice_init_lock);
if (splice_init_state != 0) {
sx_xunlock(&splice_init_lock);
return (0);
}
splice_zone = uma_zcreate("splice", sizeof(struct so_splice), NULL,
NULL, splice_zinit, splice_zfini, UMA_ALIGN_CACHE, 0);
splice_wq = mallocarray(mp_maxid + 1, sizeof(*splice_wq), M_TEMP,
M_WAITOK | M_ZERO);
/*
* Initialize the workqueues to run the splice work. We create a
* work queue for each CPU.
*/
CPU_FOREACH(i) {
STAILQ_INIT(&splice_wq[i].head);
mtx_init(&splice_wq[i].mtx, "splice work queue", NULL, MTX_DEF);
}
/* Start kthreads for each workqueue. */
error = 0;
CPU_FOREACH(i) {
error = kproc_kthread_add(splice_work_thread, &splice_wq[i],
&splice_proc, &td, 0, 0, "so_splice", "thr_%d", i);
if (error) {
printf("Can't add so_splice thread %d error %d\n",
i, error);
break;
}
/*
* It's possible to create loops with SO_SPLICE; ensure that
* worker threads aren't able to starve the system too easily.
*/
thread_lock(td);
sched_prio(td, PUSER);
thread_unlock(td);
}
splice_init_state = error != 0 ? -1 : 1;
sx_xunlock(&splice_init_lock);
return (error);
}
/*
* Lock a pair of socket's I/O locks for splicing. Avoid blocking while holding
* one lock in order to avoid potential deadlocks in case there is some other
* code path which acquires more than one I/O lock at a time.
*/
static void
splice_lock_pair(struct socket *so_src, struct socket *so_dst)
{
int error;
for (;;) {
error = SOCK_IO_SEND_LOCK(so_dst, SBL_WAIT | SBL_NOINTR);
KASSERT(error == 0,
("%s: failed to lock send I/O lock: %d", __func__, error));
error = SOCK_IO_RECV_LOCK(so_src, 0);
KASSERT(error == 0 || error == EWOULDBLOCK,
("%s: failed to lock recv I/O lock: %d", __func__, error));
if (error == 0)
break;
SOCK_IO_SEND_UNLOCK(so_dst);
error = SOCK_IO_RECV_LOCK(so_src, SBL_WAIT | SBL_NOINTR);
KASSERT(error == 0,
("%s: failed to lock recv I/O lock: %d", __func__, error));
error = SOCK_IO_SEND_LOCK(so_dst, 0);
KASSERT(error == 0 || error == EWOULDBLOCK,
("%s: failed to lock send I/O lock: %d", __func__, error));
if (error == 0)
break;
SOCK_IO_RECV_UNLOCK(so_src);
}
}
static void
splice_unlock_pair(struct socket *so_src, struct socket *so_dst)
{
SOCK_IO_RECV_UNLOCK(so_src);
SOCK_IO_SEND_UNLOCK(so_dst);
}
/*
* Move data from the source to the sink. Assumes that both of the relevant
* socket I/O locks are held.
*/
static int
so_splice_xfer_data(struct socket *so_src, struct socket *so_dst, off_t max,
ssize_t *lenp)
{
struct uio uio;
struct mbuf *m;
struct sockbuf *sb_src, *sb_dst;
ssize_t len;
long space;
int error, flags;
SOCK_IO_RECV_ASSERT_LOCKED(so_src);
SOCK_IO_SEND_ASSERT_LOCKED(so_dst);
error = 0;
m = NULL;
memset(&uio, 0, sizeof(uio));
sb_src = &so_src->so_rcv;
sb_dst = &so_dst->so_snd;
space = sbspace(sb_dst);
if (space < 0)
space = 0;
len = MIN(max, MIN(space, sbavail(sb_src)));
if (len == 0) {
SOCK_RECVBUF_LOCK(so_src);
if ((sb_src->sb_state & SBS_CANTRCVMORE) != 0)
error = EPIPE;
SOCK_RECVBUF_UNLOCK(so_src);
} else {
flags = MSG_DONTWAIT;
uio.uio_resid = len;
if (splice_receive_stream && sb_src->sb_tls_info == NULL) {
error = soreceive_stream_locked(so_src, sb_src, NULL,
&uio, &m, NULL, flags);
} else {
error = soreceive_generic_locked(so_src, NULL,
&uio, &m, NULL, &flags);
}
if (error != 0 && m != NULL) {
m_freem(m);
m = NULL;
}
}
if (m != NULL) {
len -= uio.uio_resid;
error = sosend_generic_locked(so_dst, NULL, NULL, m, NULL,
MSG_DONTWAIT, curthread);
} else if (error == 0) {
len = 0;
SOCK_SENDBUF_LOCK(so_dst);
if ((sb_dst->sb_state & SBS_CANTSENDMORE) != 0)
error = EPIPE;
SOCK_SENDBUF_UNLOCK(so_dst);
}
if (error == 0)
*lenp = len;
return (error);
}
/*
* Transfer data from the source to the sink.
*/
static void
so_splice_xfer(struct so_splice *sp)
{
struct socket *so_src, *so_dst;
off_t max;
ssize_t len;
int error;
mtx_assert(&sp->mtx, MA_OWNED);
KASSERT(sp->state == SPLICE_QUEUED || sp->state == SPLICE_CLOSING,
("so_splice_xfer: invalid state %d", sp->state));
KASSERT(sp->max != 0, ("so_splice_xfer: max == 0"));
if (sp->state == SPLICE_CLOSING) {
/* Userspace asked us to close the splice. */
goto closing;
}
sp->state = SPLICE_RUNNING;
so_src = sp->src;
so_dst = sp->dst;
max = sp->max > 0 ? sp->max - so_src->so_splice_sent : OFF_MAX;
if (max < 0)
max = 0;
/*
* Lock the sockets in order to block userspace from doing anything
* sneaky. If an error occurs or one of the sockets can no longer
* transfer data, we will automatically unsplice.
*/
mtx_unlock(&sp->mtx);
splice_lock_pair(so_src, so_dst);
error = so_splice_xfer_data(so_src, so_dst, max, &len);
mtx_lock(&sp->mtx);
/*
* Update our stats while still holding the socket locks. This
* synchronizes with getsockopt(SO_SPLICE), see the comment there.
*/
if (error == 0) {
KASSERT(len >= 0, ("%s: len %zd < 0", __func__, len));
so_src->so_splice_sent += len;
}
splice_unlock_pair(so_src, so_dst);
switch (sp->state) {
case SPLICE_CLOSING:
closing:
sp->state = SPLICE_CLOSED;
wakeup(sp);
mtx_unlock(&sp->mtx);
break;
case SPLICE_RUNNING:
if (error != 0 ||
(sp->max > 0 && so_src->so_splice_sent >= sp->max)) {
sp->state = SPLICE_EXCEPTION;
soref(so_src);
mtx_unlock(&sp->mtx);
(void)so_unsplice(so_src, false);
sorele(so_src);
} else {
/*
* Locklessly check for additional bytes in the source's
* receive buffer and queue more work if possible. We
* may end up queuing needless work, but that's ok, and
* if we race with a thread inserting more data into the
* buffer and observe sbavail() == 0, the splice mutex
* ensures that splice_push() will queue more work for
* us.
*/
if (sbavail(&so_src->so_rcv) > 0 &&
sbspace(&so_dst->so_snd) > 0) {
sp->state = SPLICE_QUEUED;
mtx_unlock(&sp->mtx);
so_splice_dispatch_async(sp);
} else {
sp->state = SPLICE_IDLE;
mtx_unlock(&sp->mtx);
}
}
break;
default:
__assert_unreachable();
}
}
static void
socket_init(void *tag)
{
socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, 0);
maxsockets = uma_zone_set_max(socket_zone, maxsockets);
uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
EVENTHANDLER_PRI_FIRST);
}
SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
#ifdef SOCKET_HHOOK
static void
socket_hhook_register(int subtype)
{
if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
&V_socket_hhh[subtype],
HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register hook\n", __func__);
}
static void
socket_hhook_deregister(int subtype)
{
if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
printf("%s: WARNING: unable to deregister hook\n", __func__);
}
static void
socket_vnet_init(const void *unused __unused)
{
int i;
/* We expect a contiguous range */
for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
socket_hhook_register(i);
}
VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
socket_vnet_init, NULL);
static void
socket_vnet_uninit(const void *unused __unused)
{
int i;
for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
socket_hhook_deregister(i);
}
VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
socket_vnet_uninit, NULL);
#endif /* SOCKET_HHOOK */
/*
* Initialise maxsockets. This SYSINIT must be run after
* tunable_mbinit().
*/
static void
init_maxsockets(void *ignored)
{
TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
maxsockets = imax(maxsockets, maxfiles);
}
SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
/*
* Sysctl to get and set the maximum global sockets limit. Notify protocols
* of the change so that they can update their dependent limits as required.
*/
static int
sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
{
int error, newmaxsockets;
newmaxsockets = maxsockets;
error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
if (error == 0 && req->newptr && newmaxsockets != maxsockets) {
if (newmaxsockets > maxsockets &&
newmaxsockets <= maxfiles) {
maxsockets = newmaxsockets;
EVENTHANDLER_INVOKE(maxsockets_change);
} else
error = EINVAL;
}
return (error);
}
SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets,
CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
&maxsockets, 0, sysctl_maxsockets, "IU",
"Maximum number of sockets available");
/*
* Socket operation routines. These routines are called by the routines in
* sys_socket.c or from a system process, and implement the semantics of
* socket operations by switching out to the protocol specific routines.
*/
/*
* Get a socket structure from our zone, and initialize it. Note that it
* would probably be better to allocate socket and PCB at the same time, but
* I'm not convinced that all the protocols can be easily modified to do
* this.
*
* soalloc() returns a socket with a ref count of 0.
*/
static struct socket *
soalloc(struct vnet *vnet)
{
struct socket *so;
so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
if (so == NULL)
return (NULL);
#ifdef MAC
if (mac_socket_init(so, M_NOWAIT) != 0) {
uma_zfree(socket_zone, so);
return (NULL);
}
#endif
if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
uma_zfree(socket_zone, so);
return (NULL);
}
/*
* The socket locking protocol allows to lock 2 sockets at a time,
* however, the first one must be a listening socket. WITNESS lacks
* a feature to change class of an existing lock, so we use DUPOK.
*/
mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
- mtx_init(&so->so_snd_mtx, "so_snd", NULL, MTX_DEF);
- mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF);
so->so_rcv.sb_sel = &so->so_rdsel;
so->so_snd.sb_sel = &so->so_wrsel;
sx_init(&so->so_snd_sx, "so_snd_sx");
sx_init(&so->so_rcv_sx, "so_rcv_sx");
TAILQ_INIT(&so->so_snd.sb_aiojobq);
TAILQ_INIT(&so->so_rcv.sb_aiojobq);
TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
#ifdef VIMAGE
VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
__func__, __LINE__, so));
so->so_vnet = vnet;
#endif
#ifdef SOCKET_HHOOK
/* We shouldn't need the so_global_mtx */
if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
/* Do we need more comprehensive error returns? */
uma_zfree(socket_zone, so);
return (NULL);
}
#endif
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
++numopensockets;
#ifdef VIMAGE
vnet->vnet_sockcnt++;
#endif
mtx_unlock(&so_global_mtx);
return (so);
}
/*
* Free the storage associated with a socket at the socket layer, tear down
* locks, labels, etc. All protocol state is assumed already to have been
* torn down (and possibly never set up) by the caller.
*/
void
sodealloc(struct socket *so)
{
KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
--numopensockets; /* Could be below, but faster here. */
#ifdef VIMAGE
VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
__func__, __LINE__, so));
so->so_vnet->vnet_sockcnt--;
#endif
mtx_unlock(&so_global_mtx);
#ifdef MAC
mac_socket_destroy(so);
#endif
#ifdef SOCKET_HHOOK
hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
#endif
khelp_destroy_osd(&so->osd);
if (SOLISTENING(so)) {
if (so->sol_accept_filter != NULL)
accept_filt_setopt(so, NULL);
} else {
if (so->so_rcv.sb_hiwat)
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
if (so->so_snd.sb_hiwat)
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
sx_destroy(&so->so_snd_sx);
sx_destroy(&so->so_rcv_sx);
- mtx_destroy(&so->so_snd_mtx);
- mtx_destroy(&so->so_rcv_mtx);
}
crfree(so->so_cred);
mtx_destroy(&so->so_lock);
uma_zfree(socket_zone, so);
}
+/*
+ * Shim to accomodate protocols that already do their own socket buffers
+ * management (marked with PR_SOCKBUF) with protocols that yet do not.
+ *
+ * Attach via socket(2) is different from attach via accept(2). In case of
+ * normal socket(2) syscall it is the pr_attach that calls soreserve(), even
+ * for protocols that don't yet do PR_SOCKBUF. In case of accepted connection
+ * it is our shim that calls soreserve() and the hiwat values are taken from
+ * the parent socket.
+ */
+static int
+soattach(struct socket *so, int proto, struct thread *td, struct socket *head)
+{
+ int error;
+
+ VNET_ASSERT(curvnet == so->so_vnet,
+ ("%s: %p != %p", __func__, curvnet, so->so_vnet));
+
+ if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
+ mtx_init(&so->so_snd_mtx, "so_snd", NULL, MTX_DEF);
+ mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF);
+ so->so_snd.sb_mtx = &so->so_snd_mtx;
+ so->so_rcv.sb_mtx = &so->so_rcv_mtx;
+ }
+ if (head == NULL || (error = soreserve(so, head->sol_sbsnd_hiwat,
+ head->sol_sbrcv_hiwat)) == 0)
+ error = so->so_proto->pr_attach(so, proto, td);
+ if (error != 0 && (so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
+ mtx_destroy(&so->so_snd_mtx);
+ mtx_destroy(&so->so_rcv_mtx);
+ }
+
+ return (error);
+}
+
/*
* socreate returns a socket with a ref count of 1 and a file descriptor
* reference. The socket should be closed with soclose().
*/
int
socreate(int dom, struct socket **aso, int type, int proto,
struct ucred *cred, struct thread *td)
{
struct protosw *prp;
struct socket *so;
int error;
prp = pffindproto(dom, type, proto);
if (prp == NULL) {
/* No support for domain. */
if (pffinddomain(dom) == NULL)
return (EAFNOSUPPORT);
/* No support for socket type. */
if (proto == 0 && type != 0)
return (EPROTOTYPE);
return (EPROTONOSUPPORT);
}
MPASS(prp->pr_attach);
if ((prp->pr_flags & PR_CAPATTACH) == 0) {
if (CAP_TRACING(td))
ktrcapfail(CAPFAIL_PROTO, &proto);
if (IN_CAPABILITY_MODE(td))
return (ECAPMODE);
}
if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
return (EPROTONOSUPPORT);
so = soalloc(CRED_TO_VNET(cred));
if (so == NULL)
return (ENOBUFS);
so->so_type = type;
so->so_cred = crhold(cred);
if ((prp->pr_domain->dom_family == PF_INET) ||
(prp->pr_domain->dom_family == PF_INET6) ||
(prp->pr_domain->dom_family == PF_ROUTE))
so->so_fibnum = td->td_proc->p_fibnum;
else
so->so_fibnum = 0;
so->so_proto = prp;
#ifdef MAC
mac_socket_create(cred, so);
#endif
knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
so_rdknl_assert_lock);
knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
so_wrknl_assert_lock);
- if ((prp->pr_flags & PR_SOCKBUF) == 0) {
- so->so_snd.sb_mtx = &so->so_snd_mtx;
- so->so_rcv.sb_mtx = &so->so_rcv_mtx;
- }
- /*
- * Auto-sizing of socket buffers is managed by the protocols and
- * the appropriate flags must be set in the pr_attach() method.
- */
CURVNET_SET(so->so_vnet);
- error = prp->pr_attach(so, proto, td);
+ error = soattach(so, proto, td, NULL);
CURVNET_RESTORE();
if (error) {
sodealloc(so);
return (error);
}
soref(so);
*aso = so;
return (0);
}
#ifdef REGRESSION
static int regression_sonewconn_earlytest = 1;
SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
&regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
#endif
static int sooverprio = LOG_DEBUG;
SYSCTL_INT(_kern_ipc, OID_AUTO, sooverprio, CTLFLAG_RW,
&sooverprio, 0, "Log priority for listen socket overflows: 0..7 or -1 to disable");
static struct timeval overinterval = { 60, 0 };
SYSCTL_TIMEVAL_SEC(_kern_ipc, OID_AUTO, sooverinterval, CTLFLAG_RW,
&overinterval,
"Delay in seconds between warnings for listen socket overflows");
/*
* When an attempt at a new connection is noted on a socket which supports
* accept(2), the protocol has two options:
* 1) Call legacy sonewconn() function, which would call protocol attach
* method, same as used for socket(2).
* 2) Call solisten_clone(), do attach that is specific to a cloned connection,
* and then call solisten_enqueue().
*
* Note: the ref count on the socket is 0 on return.
*/
struct socket *
solisten_clone(struct socket *head)
{
struct sbuf descrsb;
struct socket *so;
int len, overcount;
u_int qlen;
const char localprefix[] = "local:";
char descrbuf[SUNPATHLEN + sizeof(localprefix)];
#if defined(INET6)
char addrbuf[INET6_ADDRSTRLEN];
#elif defined(INET)
char addrbuf[INET_ADDRSTRLEN];
#endif
bool dolog, over;
SOLISTEN_LOCK(head);
over = (head->sol_qlen > 3 * head->sol_qlimit / 2);
#ifdef REGRESSION
if (regression_sonewconn_earlytest && over) {
#else
if (over) {
#endif
head->sol_overcount++;
dolog = (sooverprio >= 0) &&
!!ratecheck(&head->sol_lastover, &overinterval);
/*
* If we're going to log, copy the overflow count and queue
* length from the listen socket before dropping the lock.
* Also, reset the overflow count.
*/
if (dolog) {
overcount = head->sol_overcount;
head->sol_overcount = 0;
qlen = head->sol_qlen;
}
SOLISTEN_UNLOCK(head);
if (dolog) {
/*
* Try to print something descriptive about the
* socket for the error message.
*/
sbuf_new(&descrsb, descrbuf, sizeof(descrbuf),
SBUF_FIXEDLEN);
switch (head->so_proto->pr_domain->dom_family) {
#if defined(INET) || defined(INET6)
#ifdef INET
case AF_INET:
#endif
#ifdef INET6
case AF_INET6:
if (head->so_proto->pr_domain->dom_family ==
AF_INET6 ||
(sotoinpcb(head)->inp_inc.inc_flags &
INC_ISIPV6)) {
ip6_sprintf(addrbuf,
&sotoinpcb(head)->inp_inc.inc6_laddr);
sbuf_printf(&descrsb, "[%s]", addrbuf);
} else
#endif
{
#ifdef INET
inet_ntoa_r(
sotoinpcb(head)->inp_inc.inc_laddr,
addrbuf);
sbuf_cat(&descrsb, addrbuf);
#endif
}
sbuf_printf(&descrsb, ":%hu (proto %u)",
ntohs(sotoinpcb(head)->inp_inc.inc_lport),
head->so_proto->pr_protocol);
break;
#endif /* INET || INET6 */
case AF_UNIX:
sbuf_cat(&descrsb, localprefix);
if (sotounpcb(head)->unp_addr != NULL)
len =
sotounpcb(head)->unp_addr->sun_len -
offsetof(struct sockaddr_un,
sun_path);
else
len = 0;
if (len > 0)
sbuf_bcat(&descrsb,
sotounpcb(head)->unp_addr->sun_path,
len);
else
sbuf_cat(&descrsb, "(unknown)");
break;
}
/*
* If we can't print something more specific, at least
* print the domain name.
*/
if (sbuf_finish(&descrsb) != 0 ||
sbuf_len(&descrsb) <= 0) {
sbuf_clear(&descrsb);
sbuf_cat(&descrsb,
head->so_proto->pr_domain->dom_name ?:
"unknown");
sbuf_finish(&descrsb);
}
KASSERT(sbuf_len(&descrsb) > 0,
("%s: sbuf creation failed", __func__));
/*
* Preserve the historic listen queue overflow log
* message, that starts with "sonewconn:". It has
* been known to sysadmins for years and also test
* sys/kern/sonewconn_overflow checks for it.
*/
if (head->so_cred == 0) {
log(LOG_PRI(sooverprio),
"sonewconn: pcb %p (%s): "
"Listen queue overflow: %i already in "
"queue awaiting acceptance (%d "
"occurrences)\n", head->so_pcb,
sbuf_data(&descrsb),
qlen, overcount);
} else {
log(LOG_PRI(sooverprio),
"sonewconn: pcb %p (%s): "
"Listen queue overflow: "
"%i already in queue awaiting acceptance "
"(%d occurrences), euid %d, rgid %d, jail %s\n",
head->so_pcb, sbuf_data(&descrsb), qlen,
overcount, head->so_cred->cr_uid,
head->so_cred->cr_rgid,
head->so_cred->cr_prison ?
head->so_cred->cr_prison->pr_name :
"not_jailed");
}
sbuf_delete(&descrsb);
overcount = 0;
}
return (NULL);
}
SOLISTEN_UNLOCK(head);
VNET_ASSERT(head->so_vnet != NULL, ("%s: so %p vnet is NULL",
__func__, head));
so = soalloc(head->so_vnet);
if (so == NULL) {
log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
"limit reached or out of memory\n",
__func__, head->so_pcb);
return (NULL);
}
so->so_listen = head;
so->so_type = head->so_type;
/*
* POSIX is ambiguous on what options an accept(2)ed socket should
* inherit from the listener. Words "create a new socket" may be
* interpreted as not inheriting anything. Best programming practice
* for application developers is to not rely on such inheritance.
* FreeBSD had historically inherited all so_options excluding
* SO_ACCEPTCONN, which virtually means all SOL_SOCKET level options,
* including those completely irrelevant to a new born socket. For
* compatibility with older versions we will inherit a list of
* meaningful options.
* The crucial bit to inherit is SO_ACCEPTFILTER. We need it present
* in the child socket for soisconnected() promoting socket from the
* incomplete queue to complete. It will be cleared before the child
* gets available to accept(2).
*/
so->so_options = head->so_options & (SO_ACCEPTFILTER | SO_KEEPALIVE |
SO_DONTROUTE | SO_LINGER | SO_OOBINLINE | SO_NOSIGPIPE);
so->so_linger = head->so_linger;
so->so_state = head->so_state;
so->so_fibnum = head->so_fibnum;
so->so_proto = head->so_proto;
so->so_cred = crhold(head->so_cred);
#ifdef SOCKET_HHOOK
if (V_socket_hhh[HHOOK_SOCKET_NEWCONN]->hhh_nhooks > 0) {
if (hhook_run_socket(so, head, HHOOK_SOCKET_NEWCONN)) {
sodealloc(so);
log(LOG_DEBUG, "%s: hhook run failed\n", __func__);
return (NULL);
}
}
#endif
#ifdef MAC
mac_socket_newconn(head, so);
#endif
knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
so_rdknl_assert_lock);
knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
so_wrknl_assert_lock);
- VNET_SO_ASSERT(head);
- if (soreserve(so, head->sol_sbsnd_hiwat, head->sol_sbrcv_hiwat)) {
- sodealloc(so);
- log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
- __func__, head->so_pcb);
- return (NULL);
- }
so->so_rcv.sb_lowat = head->sol_sbrcv_lowat;
so->so_snd.sb_lowat = head->sol_sbsnd_lowat;
so->so_rcv.sb_timeo = head->sol_sbrcv_timeo;
so->so_snd.sb_timeo = head->sol_sbsnd_timeo;
so->so_rcv.sb_flags = head->sol_sbrcv_flags & SB_AUTOSIZE;
so->so_snd.sb_flags = head->sol_sbsnd_flags &
(SB_AUTOSIZE | SB_AUTOLOWAT);
- if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
- so->so_snd.sb_mtx = &so->so_snd_mtx;
- so->so_rcv.sb_mtx = &so->so_rcv_mtx;
- }
return (so);
}
/* Connstatus may be 0 or SS_ISCONNECTED. */
struct socket *
sonewconn(struct socket *head, int connstatus)
{
struct socket *so;
if ((so = solisten_clone(head)) == NULL)
return (NULL);
- if (so->so_proto->pr_attach(so, 0, NULL) != 0) {
+ if (soattach(so, 0, NULL, head) != 0) {
sodealloc(so);
log(LOG_DEBUG, "%s: pcb %p: pr_attach() failed\n",
__func__, head->so_pcb);
return (NULL);
}
(void)solisten_enqueue(so, connstatus);
return (so);
}
/*
* Enqueue socket cloned by solisten_clone() to the listen queue of the
* listener it has been cloned from.
*
* Return 'true' if socket landed on complete queue, otherwise 'false'.
*/
bool
solisten_enqueue(struct socket *so, int connstatus)
{
struct socket *head = so->so_listen;
MPASS(refcount_load(&so->so_count) == 0);
refcount_init(&so->so_count, 1);
SOLISTEN_LOCK(head);
if (head->sol_accept_filter != NULL)
connstatus = 0;
so->so_state |= connstatus;
soref(head); /* A socket on (in)complete queue refs head. */
if (connstatus) {
TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
so->so_qstate = SQ_COMP;
head->sol_qlen++;
solisten_wakeup(head); /* unlocks */
return (true);
} else {
/*
* Keep removing sockets from the head until there's room for
* us to insert on the tail. In pre-locking revisions, this
* was a simple if(), but as we could be racing with other
* threads and soabort() requires dropping locks, we must
* loop waiting for the condition to be true.
*/
while (head->sol_incqlen > head->sol_qlimit) {
struct socket *sp;
sp = TAILQ_FIRST(&head->sol_incomp);
TAILQ_REMOVE(&head->sol_incomp, sp, so_list);
head->sol_incqlen--;
SOCK_LOCK(sp);
sp->so_qstate = SQ_NONE;
sp->so_listen = NULL;
SOCK_UNLOCK(sp);
sorele_locked(head); /* does SOLISTEN_UNLOCK, head stays */
soabort(sp);
SOLISTEN_LOCK(head);
}
TAILQ_INSERT_TAIL(&head->sol_incomp, so, so_list);
so->so_qstate = SQ_INCOMP;
head->sol_incqlen++;
SOLISTEN_UNLOCK(head);
return (false);
}
}
#if defined(SCTP) || defined(SCTP_SUPPORT)
/*
* Socket part of sctp_peeloff(). Create a new socket for an
* association. The new socket is returned with a reference.
*
* XXXGL: reduce copy-paste with solisten_clone().
*/
struct socket *
sopeeloff(struct socket *head)
{
struct socket *so;
VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
__func__, __LINE__, head));
KASSERT(head->so_type == SOCK_SEQPACKET,
("%s: unexpecte so_type: %d", __func__, head->so_type));
so = soalloc(head->so_vnet);
if (so == NULL) {
log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
"limit reached or out of memory\n",
__func__, head->so_pcb);
return (NULL);
}
so->so_type = SOCK_STREAM;
so->so_options = head->so_options;
so->so_linger = head->so_linger;
so->so_state = (head->so_state & SS_NBIO) | SS_ISCONNECTED;
so->so_fibnum = head->so_fibnum;
so->so_proto = head->so_proto;
so->so_cred = crhold(head->so_cred);
#ifdef MAC
mac_socket_newconn(head, so);
#endif
knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
so_rdknl_assert_lock);
knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
so_wrknl_assert_lock);
- VNET_SO_ASSERT(head);
- if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
- sodealloc(so);
- log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
- __func__, head->so_pcb);
- return (NULL);
- }
- if (so->so_proto->pr_attach(so, 0, NULL)) {
+ if (soattach(so, 0, NULL, head)) {
sodealloc(so);
log(LOG_DEBUG, "%s: pcb %p: pr_attach() failed\n",
__func__, head->so_pcb);
return (NULL);
}
so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
so->so_snd.sb_lowat = head->so_snd.sb_lowat;
so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
so->so_snd.sb_timeo = head->so_snd.sb_timeo;
so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
- if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
- so->so_snd.sb_mtx = &so->so_snd_mtx;
- so->so_rcv.sb_mtx = &so->so_rcv_mtx;
- }
soref(so);
return (so);
}
#endif /* SCTP */
int
sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_bind(so, nam, td);
CURVNET_RESTORE();
return (error);
}
int
sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_bindat(fd, so, nam, td);
CURVNET_RESTORE();
return (error);
}
/*
* solisten() transitions a socket from a non-listening state to a listening
* state, but can also be used to update the listen queue depth on an
* existing listen socket. The protocol will call back into the sockets
* layer using solisten_proto_check() and solisten_proto() to check and set
* socket-layer listen state. Call backs are used so that the protocol can
* acquire both protocol and socket layer locks in whatever order is required
* by the protocol.
*
* Protocol implementors are advised to hold the socket lock across the
* socket-layer test and set to avoid races at the socket layer.
*/
int
solisten(struct socket *so, int backlog, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_listen(so, backlog, td);
CURVNET_RESTORE();
return (error);
}
/*
* Prepare for a call to solisten_proto(). Acquire all socket buffer locks in
* order to interlock with socket I/O.
*/
int
solisten_proto_check(struct socket *so)
{
SOCK_LOCK_ASSERT(so);
if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
SS_ISDISCONNECTING)) != 0)
return (EINVAL);
/*
* Sleeping is not permitted here, so simply fail if userspace is
* attempting to transmit or receive on the socket. This kind of
* transient failure is not ideal, but it should occur only if userspace
* is misusing the socket interfaces.
*/
if (!sx_try_xlock(&so->so_snd_sx))
return (EAGAIN);
if (!sx_try_xlock(&so->so_rcv_sx)) {
sx_xunlock(&so->so_snd_sx);
return (EAGAIN);
}
mtx_lock(&so->so_snd_mtx);
mtx_lock(&so->so_rcv_mtx);
/* Interlock with soo_aio_queue() and KTLS. */
if (!SOLISTENING(so)) {
bool ktls;
#ifdef KERN_TLS
ktls = so->so_snd.sb_tls_info != NULL ||
so->so_rcv.sb_tls_info != NULL;
#else
ktls = false;
#endif
if (ktls ||
(so->so_snd.sb_flags & (SB_AIO | SB_AIO_RUNNING)) != 0 ||
(so->so_rcv.sb_flags & (SB_AIO | SB_AIO_RUNNING)) != 0) {
solisten_proto_abort(so);
return (EINVAL);
}
}
return (0);
}
/*
* Undo the setup done by solisten_proto_check().
*/
void
solisten_proto_abort(struct socket *so)
{
mtx_unlock(&so->so_snd_mtx);
mtx_unlock(&so->so_rcv_mtx);
sx_xunlock(&so->so_snd_sx);
sx_xunlock(&so->so_rcv_sx);
}
void
solisten_proto(struct socket *so, int backlog)
{
int sbrcv_lowat, sbsnd_lowat;
u_int sbrcv_hiwat, sbsnd_hiwat;
short sbrcv_flags, sbsnd_flags;
sbintime_t sbrcv_timeo, sbsnd_timeo;
SOCK_LOCK_ASSERT(so);
KASSERT((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
SS_ISDISCONNECTING)) == 0,
("%s: bad socket state %p", __func__, so));
if (SOLISTENING(so))
goto listening;
/*
* Change this socket to listening state.
*/
sbrcv_lowat = so->so_rcv.sb_lowat;
sbsnd_lowat = so->so_snd.sb_lowat;
sbrcv_hiwat = so->so_rcv.sb_hiwat;
sbsnd_hiwat = so->so_snd.sb_hiwat;
sbrcv_flags = so->so_rcv.sb_flags;
sbsnd_flags = so->so_snd.sb_flags;
sbrcv_timeo = so->so_rcv.sb_timeo;
sbsnd_timeo = so->so_snd.sb_timeo;
#ifdef MAC
mac_socketpeer_label_free(so->so_peerlabel);
#endif
if (!(so->so_proto->pr_flags & PR_SOCKBUF)) {
sbdestroy(so, SO_SND);
sbdestroy(so, SO_RCV);
}
#ifdef INVARIANTS
bzero(&so->so_rcv,
sizeof(struct socket) - offsetof(struct socket, so_rcv));
#endif
so->sol_sbrcv_lowat = sbrcv_lowat;
so->sol_sbsnd_lowat = sbsnd_lowat;
so->sol_sbrcv_hiwat = sbrcv_hiwat;
so->sol_sbsnd_hiwat = sbsnd_hiwat;
so->sol_sbrcv_flags = sbrcv_flags;
so->sol_sbsnd_flags = sbsnd_flags;
so->sol_sbrcv_timeo = sbrcv_timeo;
so->sol_sbsnd_timeo = sbsnd_timeo;
so->sol_qlen = so->sol_incqlen = 0;
TAILQ_INIT(&so->sol_incomp);
TAILQ_INIT(&so->sol_comp);
so->sol_accept_filter = NULL;
so->sol_accept_filter_arg = NULL;
so->sol_accept_filter_str = NULL;
so->sol_upcall = NULL;
so->sol_upcallarg = NULL;
so->so_options |= SO_ACCEPTCONN;
listening:
if (backlog < 0 || backlog > V_somaxconn)
backlog = V_somaxconn;
so->sol_qlimit = backlog;
mtx_unlock(&so->so_snd_mtx);
mtx_unlock(&so->so_rcv_mtx);
sx_xunlock(&so->so_snd_sx);
sx_xunlock(&so->so_rcv_sx);
}
/*
* Wakeup listeners/subsystems once we have a complete connection.
* Enters with lock, returns unlocked.
*/
void
solisten_wakeup(struct socket *sol)
{
if (sol->sol_upcall != NULL)
(void )sol->sol_upcall(sol, sol->sol_upcallarg, M_NOWAIT);
else {
selwakeuppri(&sol->so_rdsel, PSOCK);
KNOTE_LOCKED(&sol->so_rdsel.si_note, 0);
}
SOLISTEN_UNLOCK(sol);
wakeup_one(&sol->sol_comp);
if ((sol->so_state & SS_ASYNC) && sol->so_sigio != NULL)
pgsigio(&sol->so_sigio, SIGIO, 0);
}
/*
* Return single connection off a listening socket queue. Main consumer of
* the function is kern_accept4(). Some modules, that do their own accept
* management also use the function. The socket reference held by the
* listen queue is handed to the caller.
*
* Listening socket must be locked on entry and is returned unlocked on
* return.
* The flags argument is set of accept4(2) flags and ACCEPT4_INHERIT.
*/
int
solisten_dequeue(struct socket *head, struct socket **ret, int flags)
{
struct socket *so;
int error;
SOLISTEN_LOCK_ASSERT(head);
while (!(head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp) &&
head->so_error == 0) {
error = msleep(&head->sol_comp, SOCK_MTX(head), PSOCK | PCATCH,
"accept", 0);
if (error != 0) {
SOLISTEN_UNLOCK(head);
return (error);
}
}
if (head->so_error) {
error = head->so_error;
head->so_error = 0;
} else if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp))
error = EWOULDBLOCK;
else
error = 0;
if (error) {
SOLISTEN_UNLOCK(head);
return (error);
}
so = TAILQ_FIRST(&head->sol_comp);
SOCK_LOCK(so);
KASSERT(so->so_qstate == SQ_COMP,
("%s: so %p not SQ_COMP", __func__, so));
head->sol_qlen--;
so->so_qstate = SQ_NONE;
so->so_listen = NULL;
TAILQ_REMOVE(&head->sol_comp, so, so_list);
if (flags & ACCEPT4_INHERIT)
so->so_state |= (head->so_state & SS_NBIO);
else
so->so_state |= (flags & SOCK_NONBLOCK) ? SS_NBIO : 0;
SOCK_UNLOCK(so);
sorele_locked(head);
*ret = so;
return (0);
}
static struct so_splice *
so_splice_alloc(off_t max)
{
struct so_splice *sp;
sp = uma_zalloc(splice_zone, M_WAITOK);
sp->src = NULL;
sp->dst = NULL;
sp->max = max > 0 ? max : -1;
do {
sp->wq_index = atomic_fetchadd_32(&splice_index, 1) %
(mp_maxid + 1);
} while (CPU_ABSENT(sp->wq_index));
sp->state = SPLICE_INIT;
TIMEOUT_TASK_INIT(taskqueue_thread, &sp->timeout, 0, so_splice_timeout,
sp);
return (sp);
}
static void
so_splice_free(struct so_splice *sp)
{
KASSERT(sp->state == SPLICE_CLOSED,
("so_splice_free: sp %p not closed", sp));
uma_zfree(splice_zone, sp);
}
static void
so_splice_timeout(void *arg, int pending __unused)
{
struct so_splice *sp;
sp = arg;
(void)so_unsplice(sp->src, true);
}
/*
* Splice the output from so to the input of so2.
*/
static int
so_splice(struct socket *so, struct socket *so2, struct splice *splice)
{
struct so_splice *sp;
int error;
if (splice->sp_max < 0)
return (EINVAL);
/* Handle only TCP for now; TODO: other streaming protos */
if (so->so_proto->pr_protocol != IPPROTO_TCP ||
so2->so_proto->pr_protocol != IPPROTO_TCP)
return (EPROTONOSUPPORT);
if (so->so_vnet != so2->so_vnet)
return (EINVAL);
/* so_splice_xfer() assumes that we're using these implementations. */
KASSERT(so->so_proto->pr_sosend == sosend_generic,
("so_splice: sosend not sosend_generic"));
KASSERT(so2->so_proto->pr_soreceive == soreceive_generic ||
so2->so_proto->pr_soreceive == soreceive_stream,
("so_splice: soreceive not soreceive_generic/stream"));
sp = so_splice_alloc(splice->sp_max);
so->so_splice_sent = 0;
sp->src = so;
sp->dst = so2;
error = 0;
SOCK_LOCK(so);
if (SOLISTENING(so))
error = EINVAL;
else if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING)) == 0)
error = ENOTCONN;
else if (so->so_splice != NULL)
error = EBUSY;
if (error != 0) {
SOCK_UNLOCK(so);
uma_zfree(splice_zone, sp);
return (error);
}
SOCK_RECVBUF_LOCK(so);
if (so->so_rcv.sb_tls_info != NULL) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
uma_zfree(splice_zone, sp);
return (EINVAL);
}
so->so_rcv.sb_flags |= SB_SPLICED;
so->so_splice = sp;
soref(so);
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
error = 0;
SOCK_LOCK(so2);
if (SOLISTENING(so2))
error = EINVAL;
else if ((so2->so_state & (SS_ISCONNECTED | SS_ISCONNECTING)) == 0)
error = ENOTCONN;
else if (so2->so_splice_back != NULL)
error = EBUSY;
if (error != 0) {
SOCK_UNLOCK(so2);
mtx_lock(&sp->mtx);
sp->dst = NULL;
sp->state = SPLICE_EXCEPTION;
mtx_unlock(&sp->mtx);
so_unsplice(so, false);
return (error);
}
SOCK_SENDBUF_LOCK(so2);
if (so->so_snd.sb_tls_info != NULL) {
SOCK_SENDBUF_UNLOCK(so2);
SOCK_UNLOCK(so2);
mtx_lock(&sp->mtx);
sp->dst = NULL;
sp->state = SPLICE_EXCEPTION;
mtx_unlock(&sp->mtx);
so_unsplice(so, false);
return (EINVAL);
}
so2->so_snd.sb_flags |= SB_SPLICED;
so2->so_splice_back = sp;
soref(so2);
mtx_lock(&sp->mtx);
SOCK_SENDBUF_UNLOCK(so2);
SOCK_UNLOCK(so2);
if (splice->sp_idle.tv_sec != 0 || splice->sp_idle.tv_usec != 0) {
taskqueue_enqueue_timeout_sbt(taskqueue_thread, &sp->timeout,
tvtosbt(splice->sp_idle), 0, C_PREL(4));
}
/*
* Transfer any data already present in the socket buffer.
*/
KASSERT(sp->state == SPLICE_INIT,
("so_splice: splice %p state %d", sp, sp->state));
sp->state = SPLICE_QUEUED;
so_splice_xfer(sp);
return (0);
}
static int
so_unsplice(struct socket *so, bool timeout)
{
struct socket *so2;
struct so_splice *sp;
bool drain, so2rele;
/*
* First unset SB_SPLICED and hide the splice structure so that
* wakeup routines will stop enqueuing work. This also ensures that
* a only a single thread will proceed with the unsplice.
*/
SOCK_LOCK(so);
if (SOLISTENING(so)) {
SOCK_UNLOCK(so);
return (EINVAL);
}
SOCK_RECVBUF_LOCK(so);
if ((so->so_rcv.sb_flags & SB_SPLICED) == 0) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
return (ENOTCONN);
}
sp = so->so_splice;
mtx_lock(&sp->mtx);
if (sp->state == SPLICE_INIT) {
/*
* A splice is in the middle of being set up.
*/
mtx_unlock(&sp->mtx);
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
return (ENOTCONN);
}
mtx_unlock(&sp->mtx);
so->so_rcv.sb_flags &= ~SB_SPLICED;
so->so_splice = NULL;
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
so2 = sp->dst;
if (so2 != NULL) {
SOCK_LOCK(so2);
KASSERT(!SOLISTENING(so2), ("%s: so2 is listening", __func__));
SOCK_SENDBUF_LOCK(so2);
KASSERT((so2->so_snd.sb_flags & SB_SPLICED) != 0,
("%s: so2 is not spliced", __func__));
KASSERT(so2->so_splice_back == sp,
("%s: so_splice_back != sp", __func__));
so2->so_snd.sb_flags &= ~SB_SPLICED;
so2rele = so2->so_splice_back != NULL;
so2->so_splice_back = NULL;
SOCK_SENDBUF_UNLOCK(so2);
SOCK_UNLOCK(so2);
}
/*
* No new work is being enqueued. The worker thread might be
* splicing data right now, in which case we want to wait for it to
* finish before proceeding.
*/
mtx_lock(&sp->mtx);
switch (sp->state) {
case SPLICE_QUEUED:
case SPLICE_RUNNING:
sp->state = SPLICE_CLOSING;
while (sp->state == SPLICE_CLOSING)
msleep(sp, &sp->mtx, PSOCK, "unsplice", 0);
break;
case SPLICE_INIT:
case SPLICE_IDLE:
case SPLICE_EXCEPTION:
sp->state = SPLICE_CLOSED;
break;
default:
__assert_unreachable();
}
if (!timeout) {
drain = taskqueue_cancel_timeout(taskqueue_thread, &sp->timeout,
NULL) != 0;
} else {
drain = false;
}
mtx_unlock(&sp->mtx);
if (drain)
taskqueue_drain_timeout(taskqueue_thread, &sp->timeout);
/*
* Now we hold the sole reference to the splice structure.
* Clean up: signal userspace and release socket references.
*/
sorwakeup(so);
CURVNET_SET(so->so_vnet);
sorele(so);
if (so2 != NULL) {
sowwakeup(so2);
if (so2rele)
sorele(so2);
}
CURVNET_RESTORE();
so_splice_free(sp);
return (0);
}
/*
* Free socket upon release of the very last reference.
*/
static void
sofree(struct socket *so)
{
struct protosw *pr = so->so_proto;
SOCK_LOCK_ASSERT(so);
KASSERT(refcount_load(&so->so_count) == 0,
("%s: so %p has references", __func__, so));
KASSERT(SOLISTENING(so) || so->so_qstate == SQ_NONE,
("%s: so %p is on listen queue", __func__, so));
KASSERT(SOLISTENING(so) || (so->so_rcv.sb_flags & SB_SPLICED) == 0,
("%s: so %p rcvbuf is spliced", __func__, so));
KASSERT(SOLISTENING(so) || (so->so_snd.sb_flags & SB_SPLICED) == 0,
("%s: so %p sndbuf is spliced", __func__, so));
KASSERT(so->so_splice == NULL && so->so_splice_back == NULL,
("%s: so %p has spliced data", __func__, so));
SOCK_UNLOCK(so);
if (so->so_dtor != NULL)
so->so_dtor(so);
VNET_SO_ASSERT(so);
if (pr->pr_detach != NULL)
pr->pr_detach(so);
if (!(pr->pr_flags & PR_SOCKBUF) && !SOLISTENING(so)) {
/*
* From this point on, we assume that no other references to
* this socket exist anywhere else in the stack. Therefore,
* no locks need to be acquired or held.
*/
#ifdef INVARIANTS
SOCK_SENDBUF_LOCK(so);
SOCK_RECVBUF_LOCK(so);
#endif
sbdestroy(so, SO_SND);
sbdestroy(so, SO_RCV);
#ifdef INVARIANTS
SOCK_SENDBUF_UNLOCK(so);
SOCK_RECVBUF_UNLOCK(so);
#endif
+ mtx_destroy(&so->so_snd_mtx);
+ mtx_destroy(&so->so_rcv_mtx);
}
seldrain(&so->so_rdsel);
seldrain(&so->so_wrsel);
knlist_destroy(&so->so_rdsel.si_note);
knlist_destroy(&so->so_wrsel.si_note);
sodealloc(so);
}
/*
* Release a reference on a socket while holding the socket lock.
* Unlocks the socket lock before returning.
*/
void
sorele_locked(struct socket *so)
{
SOCK_LOCK_ASSERT(so);
if (refcount_release(&so->so_count))
sofree(so);
else
SOCK_UNLOCK(so);
}
/*
* Close a socket on last file table reference removal. Initiate disconnect
* if connected. Free socket when disconnect complete.
*
* This function will sorele() the socket. Note that soclose() may be called
* prior to the ref count reaching zero. The actual socket structure will
* not be freed until the ref count reaches zero.
*/
int
soclose(struct socket *so)
{
struct accept_queue lqueue;
int error = 0;
bool listening, last __diagused;
CURVNET_SET(so->so_vnet);
funsetown(&so->so_sigio);
if (so->so_state & SS_ISCONNECTED) {
if ((so->so_state & SS_ISDISCONNECTING) == 0) {
error = sodisconnect(so);
if (error) {
if (error == ENOTCONN)
error = 0;
goto drop;
}
}
if ((so->so_options & SO_LINGER) != 0 && so->so_linger != 0) {
if ((so->so_state & SS_ISDISCONNECTING) &&
(so->so_state & SS_NBIO))
goto drop;
while (so->so_state & SS_ISCONNECTED) {
error = tsleep(&so->so_timeo,
PSOCK | PCATCH, "soclos",
so->so_linger * hz);
if (error)
break;
}
}
}
drop:
if (so->so_proto->pr_close != NULL)
so->so_proto->pr_close(so);
SOCK_LOCK(so);
if ((listening = SOLISTENING(so))) {
struct socket *sp;
TAILQ_INIT(&lqueue);
TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);
so->sol_qlen = so->sol_incqlen = 0;
TAILQ_FOREACH(sp, &lqueue, so_list) {
SOCK_LOCK(sp);
sp->so_qstate = SQ_NONE;
sp->so_listen = NULL;
SOCK_UNLOCK(sp);
last = refcount_release(&so->so_count);
KASSERT(!last, ("%s: released last reference for %p",
__func__, so));
}
}
sorele_locked(so);
if (listening) {
struct socket *sp, *tsp;
TAILQ_FOREACH_SAFE(sp, &lqueue, so_list, tsp)
soabort(sp);
}
CURVNET_RESTORE();
return (error);
}
/*
* soabort() is used to abruptly tear down a connection, such as when a
* resource limit is reached (listen queue depth exceeded), or if a listen
* socket is closed while there are sockets waiting to be accepted.
*
* This interface is tricky, because it is called on an unreferenced socket,
* and must be called only by a thread that has actually removed the socket
* from the listen queue it was on. Likely this thread holds the last
* reference on the socket and soabort() will proceed with sofree(). But
* it might be not the last, as the sockets on the listen queues are seen
* from the protocol side.
*
* This interface will call into the protocol code, so must not be called
* with any socket locks held. Protocols do call it while holding their own
* recursible protocol mutexes, but this is something that should be subject
* to review in the future.
*
* Usually socket should have a single reference left, but this is not a
* requirement. In the past, when we have had named references for file
* descriptor and protocol, we asserted that none of them are being held.
*/
void
soabort(struct socket *so)
{
VNET_SO_ASSERT(so);
if (so->so_proto->pr_abort != NULL)
so->so_proto->pr_abort(so);
SOCK_LOCK(so);
sorele_locked(so);
}
int
soaccept(struct socket *so, struct sockaddr *sa)
{
#ifdef INVARIANTS
u_char len = sa->sa_len;
#endif
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_accept(so, sa);
KASSERT(sa->sa_len <= len,
("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
CURVNET_RESTORE();
return (error);
}
int
sopeeraddr(struct socket *so, struct sockaddr *sa)
{
#ifdef INVARIANTS
u_char len = sa->sa_len;
#endif
int error;
CURVNET_ASSERT_SET();
error = so->so_proto->pr_peeraddr(so, sa);
KASSERT(sa->sa_len <= len,
("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
return (error);
}
int
sosockaddr(struct socket *so, struct sockaddr *sa)
{
#ifdef INVARIANTS
u_char len = sa->sa_len;
#endif
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_sockaddr(so, sa);
KASSERT(sa->sa_len <= len,
("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
CURVNET_RESTORE();
return (error);
}
int
soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (soconnectat(AT_FDCWD, so, nam, td));
}
int
soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
/*
* If protocol is connection-based, can only connect once.
* Otherwise, if connected, try to disconnect first. This allows
* user to disconnect by connecting to, e.g., a null address.
*
* Note, this check is racy and may need to be re-evaluated at the
* protocol layer.
*/
if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
(error = sodisconnect(so)))) {
error = EISCONN;
} else {
/*
* Prevent accumulated error from previous connection from
* biting us.
*/
so->so_error = 0;
if (fd == AT_FDCWD) {
error = so->so_proto->pr_connect(so, nam, td);
} else {
error = so->so_proto->pr_connectat(fd, so, nam, td);
}
}
CURVNET_RESTORE();
return (error);
}
int
soconnect2(struct socket *so1, struct socket *so2)
{
int error;
CURVNET_SET(so1->so_vnet);
error = so1->so_proto->pr_connect2(so1, so2);
CURVNET_RESTORE();
return (error);
}
int
sodisconnect(struct socket *so)
{
int error;
if ((so->so_state & SS_ISCONNECTED) == 0)
return (ENOTCONN);
if (so->so_state & SS_ISDISCONNECTING)
return (EALREADY);
VNET_SO_ASSERT(so);
error = so->so_proto->pr_disconnect(so);
return (error);
}
int
sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
long space;
ssize_t resid;
int clen = 0, error, dontroute;
KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
("sosend_dgram: !PR_ATOMIC"));
if (uio != NULL)
resid = uio->uio_resid;
else
resid = top->m_pkthdr.len;
/*
* In theory resid should be unsigned. However, space must be
* signed, as it might be less than 0 if we over-committed, and we
* must use a signed comparison of space and resid. On the other
* hand, a negative resid causes us to loop sending 0-length
* segments to the protocol.
*/
if (resid < 0) {
error = EINVAL;
goto out;
}
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
if (td != NULL)
td->td_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
SOCKBUF_LOCK(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EPIPE;
goto out;
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
if ((so->so_state & SS_ISCONNECTED) == 0) {
/*
* `sendto' and `sendmsg' is allowed on a connection-based
* socket if it supports implied connect. Return ENOTCONN if
* not connected and no address is supplied.
*/
if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
if (!(resid == 0 && clen != 0)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = ENOTCONN;
goto out;
}
} else if (addr == NULL) {
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EDESTADDRREQ;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
}
/*
* Do we need MSG_OOB support in SOCK_DGRAM? Signs here may be a
* problem and need fixing.
*/
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
space -= clen;
SOCKBUF_UNLOCK(&so->so_snd);
if (resid > space) {
error = EMSGSIZE;
goto out;
}
if (uio == NULL) {
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
} else {
/*
* Copy the data from userland into a mbuf chain.
* If no data is to be copied in, a single empty mbuf
* is returned.
*/
top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
(M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
if (top == NULL) {
error = EFAULT; /* only possible error */
goto out;
}
space -= resid - uio->uio_resid;
resid = uio->uio_resid;
}
KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
/*
* XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
* than with.
*/
if (dontroute) {
SOCK_LOCK(so);
so->so_options |= SO_DONTROUTE;
SOCK_UNLOCK(so);
}
/*
* XXX all the SBS_CANTSENDMORE checks previously done could be out
* of date. We could have received a reset packet in an interrupt or
* maybe we slept while doing page faults in uiomove() etc. We could
* probably recheck again inside the locking protection here, but
* there are probably other places that this also happens. We must
* rethink this.
*/
VNET_SO_ASSERT(so);
error = so->so_proto->pr_send(so, (flags & MSG_OOB) ? PRUS_OOB :
/*
* If the user set MSG_EOF, the protocol understands this flag and
* nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
*/
((flags & MSG_EOF) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) &&
(resid <= 0)) ?
PRUS_EOF :
/* If there is more to send set PRUS_MORETOCOME */
(flags & MSG_MORETOCOME) ||
(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
top, addr, control, td);
if (dontroute) {
SOCK_LOCK(so);
so->so_options &= ~SO_DONTROUTE;
SOCK_UNLOCK(so);
}
clen = 0;
control = NULL;
top = NULL;
out:
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
/*
* Send on a socket. If send must go all at once and message is larger than
* send buffering, then hard error. Lock against other senders. If must go
* all at once and not enough room now, then inform user that this would
* block and do nothing. Otherwise, if nonblocking, send as much as
* possible. The data to be sent is described by "uio" if nonzero, otherwise
* by the mbuf chain "top" (which must be null if uio is not). Data provided
* in mbuf chain must be small enough to send all at once.
*
* Returns nonzero on error, timeout or signal; callers must check for short
* counts if EINTR/ERESTART are returned. Data and control buffers are freed
* on return.
*/
static int
sosend_generic_locked(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
long space;
ssize_t resid;
int clen = 0, error, dontroute;
int atomic = sosendallatonce(so) || top;
int pr_send_flag;
#ifdef KERN_TLS
struct ktls_session *tls;
int tls_enq_cnt, tls_send_flag;
uint8_t tls_rtype;
tls = NULL;
tls_rtype = TLS_RLTYPE_APP;
#endif
SOCK_IO_SEND_ASSERT_LOCKED(so);
if (uio != NULL)
resid = uio->uio_resid;
else if ((top->m_flags & M_PKTHDR) != 0)
resid = top->m_pkthdr.len;
else
resid = m_length(top, NULL);
/*
* In theory resid should be unsigned. However, space must be
* signed, as it might be less than 0 if we over-committed, and we
* must use a signed comparison of space and resid. On the other
* hand, a negative resid causes us to loop sending 0-length
* segments to the protocol.
*
* Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
* type sockets since that's an error.
*/
if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
error = EINVAL;
goto out;
}
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
(so->so_proto->pr_flags & PR_ATOMIC);
if (td != NULL)
td->td_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
#ifdef KERN_TLS
tls_send_flag = 0;
tls = ktls_hold(so->so_snd.sb_tls_info);
if (tls != NULL) {
if (tls->mode == TCP_TLS_MODE_SW)
tls_send_flag = PRUS_NOTREADY;
if (control != NULL) {
struct cmsghdr *cm = mtod(control, struct cmsghdr *);
if (clen >= sizeof(*cm) &&
cm->cmsg_type == TLS_SET_RECORD_TYPE) {
tls_rtype = *((uint8_t *)CMSG_DATA(cm));
clen = 0;
m_freem(control);
control = NULL;
atomic = 1;
}
}
if (resid == 0 && !ktls_permit_empty_frames(tls)) {
error = EINVAL;
goto out;
}
}
#endif
restart:
do {
SOCKBUF_LOCK(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EPIPE;
goto out;
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
if ((so->so_state & SS_ISCONNECTED) == 0) {
/*
* `sendto' and `sendmsg' is allowed on a connection-
* based socket if it supports implied connect.
* Return ENOTCONN if not connected and no address is
* supplied.
*/
if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
if (!(resid == 0 && clen != 0)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = ENOTCONN;
goto out;
}
} else if (addr == NULL) {
SOCKBUF_UNLOCK(&so->so_snd);
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EDESTADDRREQ;
goto out;
}
}
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
if ((atomic && resid > so->so_snd.sb_hiwat) ||
clen > so->so_snd.sb_hiwat) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EMSGSIZE;
goto out;
}
if (space < resid + clen &&
(atomic || space < so->so_snd.sb_lowat || space < clen)) {
if ((so->so_state & SS_NBIO) ||
(flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EWOULDBLOCK;
goto out;
}
error = sbwait(so, SO_SND);
SOCKBUF_UNLOCK(&so->so_snd);
if (error)
goto out;
goto restart;
}
SOCKBUF_UNLOCK(&so->so_snd);
space -= clen;
do {
if (uio == NULL) {
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
#ifdef KERN_TLS
if (tls != NULL) {
ktls_frame(top, tls, &tls_enq_cnt,
tls_rtype);
tls_rtype = TLS_RLTYPE_APP;
}
#endif
} else {
/*
* Copy the data from userland into a mbuf
* chain. If resid is 0, which can happen
* only if we have control to send, then
* a single empty mbuf is returned. This
* is a workaround to prevent protocol send
* methods to panic.
*/
#ifdef KERN_TLS
if (tls != NULL) {
top = m_uiotombuf(uio, M_WAITOK, space,
tls->params.max_frame_len,
M_EXTPG |
((flags & MSG_EOR) ? M_EOR : 0));
if (top != NULL) {
ktls_frame(top, tls,
&tls_enq_cnt, tls_rtype);
}
tls_rtype = TLS_RLTYPE_APP;
} else
#endif
top = m_uiotombuf(uio, M_WAITOK, space,
(atomic ? max_hdr : 0),
(atomic ? M_PKTHDR : 0) |
((flags & MSG_EOR) ? M_EOR : 0));
if (top == NULL) {
error = EFAULT; /* only possible error */
goto out;
}
space -= resid - uio->uio_resid;
resid = uio->uio_resid;
}
if (dontroute) {
SOCK_LOCK(so);
so->so_options |= SO_DONTROUTE;
SOCK_UNLOCK(so);
}
/*
* XXX all the SBS_CANTSENDMORE checks previously
* done could be out of date. We could have received
* a reset packet in an interrupt or maybe we slept
* while doing page faults in uiomove() etc. We
* could probably recheck again inside the locking
* protection here, but there are probably other
* places that this also happens. We must rethink
* this.
*/
VNET_SO_ASSERT(so);
pr_send_flag = (flags & MSG_OOB) ? PRUS_OOB :
/*
* If the user set MSG_EOF, the protocol understands
* this flag and nothing left to send then use
* PRU_SEND_EOF instead of PRU_SEND.
*/
((flags & MSG_EOF) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) &&
(resid <= 0)) ?
PRUS_EOF :
/* If there is more to send set PRUS_MORETOCOME. */
(flags & MSG_MORETOCOME) ||
(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0;
#ifdef KERN_TLS
pr_send_flag |= tls_send_flag;
#endif
error = so->so_proto->pr_send(so, pr_send_flag, top,
addr, control, td);
if (dontroute) {
SOCK_LOCK(so);
so->so_options &= ~SO_DONTROUTE;
SOCK_UNLOCK(so);
}
#ifdef KERN_TLS
if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) {
if (error != 0) {
m_freem(top);
top = NULL;
} else {
soref(so);
ktls_enqueue(top, so, tls_enq_cnt);
}
}
#endif
clen = 0;
control = NULL;
top = NULL;
if (error)
goto out;
} while (resid && space > 0);
} while (resid);
out:
#ifdef KERN_TLS
if (tls != NULL)
ktls_free(tls);
#endif
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
int
sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
int error;
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
if (error)
return (error);
error = sosend_generic_locked(so, addr, uio, top, control, flags, td);
SOCK_IO_SEND_UNLOCK(so);
return (error);
}
/*
* Send to a socket from a kernel thread.
*
* XXXGL: in almost all cases uio is NULL and the mbuf is supplied.
* Exception is nfs/bootp_subr.c. It is arguable that the VNET context needs
* to be set at all. This function should just boil down to a static inline
* calling the protocol method.
*/
int
sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_sosend(so, addr, uio,
top, control, flags, td);
CURVNET_RESTORE();
return (error);
}
/*
* send(2), write(2) or aio_write(2) on a socket.
*/
int
sousrsend(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *control, int flags, struct proc *userproc)
{
struct thread *td;
ssize_t len;
int error;
td = uio->uio_td;
len = uio->uio_resid;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_sosend(so, addr, uio, NULL, control, flags,
td);
CURVNET_RESTORE();
if (error != 0) {
/*
* Clear transient errors for stream protocols if they made
* some progress. Make exclusion for aio(4) that would
* schedule a new write in case of EWOULDBLOCK and clear
* error itself. See soaio_process_job().
*/
if (uio->uio_resid != len &&
(so->so_proto->pr_flags & PR_ATOMIC) == 0 &&
userproc == NULL &&
(error == ERESTART || error == EINTR ||
error == EWOULDBLOCK))
error = 0;
/* Generation of SIGPIPE can be controlled per socket. */
if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0 &&
(flags & MSG_NOSIGNAL) == 0) {
if (userproc != NULL) {
/* aio(4) job */
PROC_LOCK(userproc);
kern_psignal(userproc, SIGPIPE);
PROC_UNLOCK(userproc);
} else {
PROC_LOCK(td->td_proc);
tdsignal(td, SIGPIPE);
PROC_UNLOCK(td->td_proc);
}
}
}
return (error);
}
/*
* The part of soreceive() that implements reading non-inline out-of-band
* data from a socket. For more complete comments, see soreceive(), from
* which this code originated.
*
* Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
* unable to return an mbuf chain to the caller.
*/
static int
soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
{
struct protosw *pr = so->so_proto;
struct mbuf *m;
int error;
KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
VNET_SO_ASSERT(so);
m = m_get(M_WAITOK, MT_DATA);
error = pr->pr_rcvoob(so, m, flags & MSG_PEEK);
if (error)
goto bad;
do {
error = uiomove(mtod(m, void *),
(int) min(uio->uio_resid, m->m_len), uio);
m = m_free(m);
} while (uio->uio_resid && error == 0 && m);
bad:
if (m != NULL)
m_freem(m);
return (error);
}
/*
* Following replacement or removal of the first mbuf on the first mbuf chain
* of a socket buffer, push necessary state changes back into the socket
* buffer so that other consumers see the values consistently. 'nextrecord'
* is the callers locally stored value of the original value of
* sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
* NOTE: 'nextrecord' may be NULL.
*/
static __inline void
sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
{
SOCKBUF_LOCK_ASSERT(sb);
/*
* First, update for the new value of nextrecord. If necessary, make
* it the first record.
*/
if (sb->sb_mb != NULL)
sb->sb_mb->m_nextpkt = nextrecord;
else
sb->sb_mb = nextrecord;
/*
* Now update any dependent socket buffer fields to reflect the new
* state. This is an expanded inline of SB_EMPTY_FIXUP(), with the
* addition of a second clause that takes care of the case where
* sb_mb has been updated, but remains the last record.
*/
if (sb->sb_mb == NULL) {
sb->sb_mbtail = NULL;
sb->sb_lastrecord = NULL;
} else if (sb->sb_mb->m_nextpkt == NULL)
sb->sb_lastrecord = sb->sb_mb;
}
/*
* Implement receive operations on a socket. We depend on the way that
* records are added to the sockbuf by sbappend. In particular, each record
* (mbufs linked through m_next) must begin with an address if the protocol
* so specifies, followed by an optional mbuf or mbufs containing ancillary
* data, and then zero or more mbufs of data. In order to allow parallelism
* between network receive and copying to user space, as well as avoid
* sleeping with a mutex held, we release the socket buffer mutex during the
* user space copy. Although the sockbuf is locked, new data may still be
* appended, and thus we must maintain consistency of the sockbuf during that
* time.
*
* The caller may receive the data as a single mbuf chain by supplying an
* mbuf **mp for use in returning the chain. The uio is then used only for
* the count in uio_resid.
*/
static int
soreceive_generic_locked(struct socket *so, struct sockaddr **psa,
struct uio *uio, struct mbuf **mp, struct mbuf **controlp, int *flagsp)
{
struct mbuf *m;
int flags, error, offset;
ssize_t len;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
int moff, type = 0;
ssize_t orig_resid = uio->uio_resid;
bool report_real_len = false;
SOCK_IO_RECV_ASSERT_LOCKED(so);
error = 0;
if (flagsp != NULL) {
report_real_len = *flagsp & MSG_TRUNC;
*flagsp &= ~MSG_TRUNC;
flags = *flagsp &~ MSG_EOR;
} else
flags = 0;
restart:
SOCKBUF_LOCK(&so->so_rcv);
m = so->so_rcv.sb_mb;
/*
* If we have less data than requested, block awaiting more (subject
* to any timeout) if:
* 1. the current count is less than the low water mark, or
* 2. MSG_DONTWAIT is not set
*/
if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
sbavail(&so->so_rcv) < uio->uio_resid) &&
sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
KASSERT(m != NULL || !sbavail(&so->so_rcv),
("receive: m == %p sbavail == %u",
m, sbavail(&so->so_rcv)));
if (so->so_error || so->so_rerror) {
if (m != NULL)
goto dontblock;
if (so->so_error)
error = so->so_error;
else
error = so->so_rerror;
if ((flags & MSG_PEEK) == 0) {
if (so->so_error)
so->so_error = 0;
else
so->so_rerror = 0;
}
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
if (m != NULL)
goto dontblock;
#ifdef KERN_TLS
else if (so->so_rcv.sb_tlsdcc == 0 &&
so->so_rcv.sb_tlscc == 0) {
#else
else {
#endif
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
}
for (; m != NULL; m = m->m_next)
if (m->m_type == MT_OOBDATA || (m->m_flags & M_EOR)) {
m = so->so_rcv.sb_mb;
goto dontblock;
}
if ((so->so_state & (SS_ISCONNECTING | SS_ISCONNECTED |
SS_ISDISCONNECTING | SS_ISDISCONNECTED)) == 0 &&
(so->so_proto->pr_flags & PR_CONNREQUIRED) != 0) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = ENOTCONN;
goto release;
}
if (uio->uio_resid == 0 && !report_real_len) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
if ((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO))) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = EWOULDBLOCK;
goto release;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
error = sbwait(so, SO_RCV);
SOCKBUF_UNLOCK(&so->so_rcv);
if (error)
goto release;
goto restart;
}
dontblock:
/*
* From this point onward, we maintain 'nextrecord' as a cache of the
* pointer to the next record in the socket buffer. We must keep the
* various socket buffer pointers and local stack versions of the
* pointers in sync, pushing out modifications before dropping the
* socket buffer mutex, and re-reading them when picking it up.
*
* Otherwise, we will race with the network stack appending new data
* or records onto the socket buffer by using inconsistent/stale
* versions of the field, possibly resulting in socket buffer
* corruption.
*
* By holding the high-level sblock(), we prevent simultaneous
* readers from pulling off the front of the socket buffer.
*/
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
nextrecord = m->m_nextpkt;
if (pr->pr_flags & PR_ADDR) {
KASSERT(m->m_type == MT_SONAME,
("m->m_type == %d", m->m_type));
orig_resid = 0;
if (psa != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *),
M_NOWAIT);
if (flags & MSG_PEEK) {
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
so->so_rcv.sb_mb = m_free(m);
m = so->so_rcv.sb_mb;
sockbuf_pushsync(&so->so_rcv, nextrecord);
}
}
/*
* Process one or more MT_CONTROL mbufs present before any data mbufs
* in the first mbuf chain on the socket buffer. If MSG_PEEK, we
* just copy the data; if !MSG_PEEK, we call into the protocol to
* perform externalization (or freeing if controlp == NULL).
*/
if (m != NULL && m->m_type == MT_CONTROL) {
struct mbuf *cm = NULL, *cmn;
struct mbuf **cme = &cm;
#ifdef KERN_TLS
struct cmsghdr *cmsg;
struct tls_get_record tgr;
/*
* For MSG_TLSAPPDATA, check for an alert record.
* If found, return ENXIO without removing
* it from the receive queue. This allows a subsequent
* call without MSG_TLSAPPDATA to receive it.
* Note that, for TLS, there should only be a single
* control mbuf with the TLS_GET_RECORD message in it.
*/
if (flags & MSG_TLSAPPDATA) {
cmsg = mtod(m, struct cmsghdr *);
if (cmsg->cmsg_type == TLS_GET_RECORD &&
cmsg->cmsg_len == CMSG_LEN(sizeof(tgr))) {
memcpy(&tgr, CMSG_DATA(cmsg), sizeof(tgr));
if (__predict_false(tgr.tls_type ==
TLS_RLTYPE_ALERT)) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = ENXIO;
goto release;
}
}
}
#endif
do {
if (flags & MSG_PEEK) {
if (controlp != NULL) {
*controlp = m_copym(m, 0, m->m_len,
M_NOWAIT);
controlp = &(*controlp)->m_next;
}
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
so->so_rcv.sb_mb = m->m_next;
m->m_next = NULL;
*cme = m;
cme = &(*cme)->m_next;
m = so->so_rcv.sb_mb;
}
} while (m != NULL && m->m_type == MT_CONTROL);
if ((flags & MSG_PEEK) == 0)
sockbuf_pushsync(&so->so_rcv, nextrecord);
while (cm != NULL) {
cmn = cm->m_next;
cm->m_next = NULL;
if (controlp != NULL)
*controlp = cm;
else
m_freem(cm);
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
cm = cmn;
}
if (m != NULL)
nextrecord = so->so_rcv.sb_mb->m_nextpkt;
else
nextrecord = so->so_rcv.sb_mb;
orig_resid = 0;
}
if (m != NULL) {
if ((flags & MSG_PEEK) == 0) {
KASSERT(m->m_nextpkt == nextrecord,
("soreceive: post-control, nextrecord !sync"));
if (nextrecord == NULL) {
KASSERT(so->so_rcv.sb_mb == m,
("soreceive: post-control, sb_mb!=m"));
KASSERT(so->so_rcv.sb_lastrecord == m,
("soreceive: post-control, lastrecord!=m"));
}
}
type = m->m_type;
if (type == MT_OOBDATA)
flags |= MSG_OOB;
} else {
if ((flags & MSG_PEEK) == 0) {
KASSERT(so->so_rcv.sb_mb == nextrecord,
("soreceive: sb_mb != nextrecord"));
if (so->so_rcv.sb_mb == NULL) {
KASSERT(so->so_rcv.sb_lastrecord == NULL,
("soreceive: sb_lastercord != NULL"));
}
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
/*
* Now continue to read any data mbufs off of the head of the socket
* buffer until the read request is satisfied. Note that 'type' is
* used to store the type of any mbuf reads that have happened so far
* such that soreceive() can stop reading if the type changes, which
* causes soreceive() to return only one of regular data and inline
* out-of-band data in a single socket receive operation.
*/
moff = 0;
offset = 0;
while (m != NULL && !(m->m_flags & M_NOTREADY) && uio->uio_resid > 0 &&
error == 0) {
/*
* If the type of mbuf has changed since the last mbuf
* examined ('type'), end the receive operation.
*/
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
if (type != m->m_type)
break;
} else if (type == MT_OOBDATA)
break;
else
KASSERT(m->m_type == MT_DATA,
("m->m_type == %d", m->m_type));
so->so_rcv.sb_state &= ~SBS_RCVATMARK;
len = uio->uio_resid;
if (so->so_oobmark && len > so->so_oobmark - offset)
len = so->so_oobmark - offset;
if (len > m->m_len - moff)
len = m->m_len - moff;
/*
* If mp is set, just pass back the mbufs. Otherwise copy
* them out via the uio, then free. Sockbuf must be
* consistent here (points to current mbuf, it points to next
* record) when we drop priority; we must note any additions
* to the sockbuf when we block interrupts again.
*/
if (mp == NULL) {
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
if ((m->m_flags & M_EXTPG) != 0)
error = m_unmapped_uiomove(m, moff, uio,
(int)len);
else
error = uiomove(mtod(m, char *) + moff,
(int)len, uio);
SOCKBUF_LOCK(&so->so_rcv);
if (error) {
/*
* The MT_SONAME mbuf has already been removed
* from the record, so it is necessary to
* remove the data mbufs, if any, to preserve
* the invariant in the case of PR_ADDR that
* requires MT_SONAME mbufs at the head of
* each record.
*/
if (pr->pr_flags & PR_ATOMIC &&
((flags & MSG_PEEK) == 0))
(void)sbdroprecord_locked(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
} else
uio->uio_resid -= len;
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (len == m->m_len - moff) {
if (m->m_flags & M_EOR)
flags |= MSG_EOR;
if (flags & MSG_PEEK) {
m = m->m_next;
moff = 0;
} else {
nextrecord = m->m_nextpkt;
sbfree(&so->so_rcv, m);
if (mp != NULL) {
m->m_nextpkt = NULL;
*mp = m;
mp = &m->m_next;
so->so_rcv.sb_mb = m = m->m_next;
*mp = NULL;
} else {
so->so_rcv.sb_mb = m_free(m);
m = so->so_rcv.sb_mb;
}
sockbuf_pushsync(&so->so_rcv, nextrecord);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
}
} else {
if (flags & MSG_PEEK)
moff += len;
else {
if (mp != NULL) {
if (flags & MSG_DONTWAIT) {
*mp = m_copym(m, 0, len,
M_NOWAIT);
if (*mp == NULL) {
/*
* m_copym() couldn't
* allocate an mbuf.
* Adjust uio_resid back
* (it was adjusted
* down by len bytes,
* which we didn't end
* up "copying" over).
*/
uio->uio_resid += len;
break;
}
} else {
SOCKBUF_UNLOCK(&so->so_rcv);
*mp = m_copym(m, 0, len,
M_WAITOK);
SOCKBUF_LOCK(&so->so_rcv);
}
}
sbcut_locked(&so->so_rcv, len);
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_oobmark) {
if ((flags & MSG_PEEK) == 0) {
so->so_oobmark -= len;
if (so->so_oobmark == 0) {
so->so_rcv.sb_state |= SBS_RCVATMARK;
break;
}
} else {
offset += len;
if (offset == so->so_oobmark)
break;
}
}
if (flags & MSG_EOR)
break;
/*
* If the MSG_WAITALL flag is set (for non-atomic socket), we
* must not quit until "uio->uio_resid == 0" or an error
* termination. If a signal/timeout occurs, return with a
* short count but without error. Keep sockbuf locked
* against other readers.
*/
while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
!sosendallatonce(so) && nextrecord == NULL) {
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_error || so->so_rerror ||
so->so_rcv.sb_state & SBS_CANTRCVMORE)
break;
/*
* Notify the protocol that some data has been
* drained before blocking.
*/
if (pr->pr_flags & PR_WANTRCVD) {
SOCKBUF_UNLOCK(&so->so_rcv);
VNET_SO_ASSERT(so);
pr->pr_rcvd(so, flags);
SOCKBUF_LOCK(&so->so_rcv);
if (__predict_false(so->so_rcv.sb_mb == NULL &&
(so->so_error || so->so_rerror ||
so->so_rcv.sb_state & SBS_CANTRCVMORE)))
break;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
/*
* We could receive some data while was notifying
* the protocol. Skip blocking in this case.
*/
if (so->so_rcv.sb_mb == NULL) {
error = sbwait(so, SO_RCV);
if (error) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
}
m = so->so_rcv.sb_mb;
if (m != NULL)
nextrecord = m->m_nextpkt;
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (m != NULL && pr->pr_flags & PR_ATOMIC) {
if (report_real_len)
uio->uio_resid -= m_length(m, NULL) - moff;
flags |= MSG_TRUNC;
if ((flags & MSG_PEEK) == 0)
(void) sbdroprecord_locked(&so->so_rcv);
}
if ((flags & MSG_PEEK) == 0) {
if (m == NULL) {
/*
* First part is an inline SB_EMPTY_FIXUP(). Second
* part makes sure sb_lastrecord is up-to-date if
* there is still data in the socket buffer.
*/
so->so_rcv.sb_mb = nextrecord;
if (so->so_rcv.sb_mb == NULL) {
so->so_rcv.sb_mbtail = NULL;
so->so_rcv.sb_lastrecord = NULL;
} else if (nextrecord->m_nextpkt == NULL)
so->so_rcv.sb_lastrecord = nextrecord;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
/*
* If soreceive() is being done from the socket callback,
* then don't need to generate ACK to peer to update window,
* since ACK will be generated on return to TCP.
*/
if (!(flags & MSG_SOCALLBCK) &&
(pr->pr_flags & PR_WANTRCVD)) {
SOCKBUF_UNLOCK(&so->so_rcv);
VNET_SO_ASSERT(so);
pr->pr_rcvd(so, flags);
SOCKBUF_LOCK(&so->so_rcv);
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (orig_resid == uio->uio_resid && orig_resid &&
(flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto restart;
}
SOCKBUF_UNLOCK(&so->so_rcv);
if (flagsp != NULL)
*flagsp |= flags;
release:
return (error);
}
int
soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp, struct mbuf **controlp, int *flagsp)
{
int error, flags;
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
if (flagsp != NULL) {
flags = *flagsp;
if ((flags & MSG_OOB) != 0)
return (soreceive_rcvoob(so, uio, flags));
} else {
flags = 0;
}
if (mp != NULL)
*mp = NULL;
error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
if (error)
return (error);
error = soreceive_generic_locked(so, psa, uio, mp, controlp, flagsp);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
/*
* Optimized version of soreceive() for stream (TCP) sockets.
*/
static int
soreceive_stream_locked(struct socket *so, struct sockbuf *sb,
struct sockaddr **psa, struct uio *uio, struct mbuf **mp0,
struct mbuf **controlp, int flags)
{
int len = 0, error = 0, oresid;
struct mbuf *m, *n = NULL;
SOCK_IO_RECV_ASSERT_LOCKED(so);
/* Easy one, no space to copyout anything. */
if (uio->uio_resid == 0)
return (EINVAL);
oresid = uio->uio_resid;
SOCKBUF_LOCK(sb);
/* We will never ever get anything unless we are or were connected. */
if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
error = ENOTCONN;
goto out;
}
restart:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
/* Abort if socket has reported problems. */
if (so->so_error) {
if (sbavail(sb) > 0)
goto deliver;
if (oresid > uio->uio_resid)
goto out;
error = so->so_error;
if (!(flags & MSG_PEEK))
so->so_error = 0;
goto out;
}
/* Door is closed. Deliver what is left, if any. */
if (sb->sb_state & SBS_CANTRCVMORE) {
if (sbavail(sb) > 0)
goto deliver;
else
goto out;
}
/* Socket buffer is empty and we shall not block. */
if (sbavail(sb) == 0 &&
((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
error = EAGAIN;
goto out;
}
/* Socket buffer got some data that we shall deliver now. */
if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO)) ||
sbavail(sb) >= sb->sb_lowat ||
sbavail(sb) >= uio->uio_resid ||
sbavail(sb) >= sb->sb_hiwat) ) {
goto deliver;
}
/* On MSG_WAITALL we must wait until all data or error arrives. */
if ((flags & MSG_WAITALL) &&
(sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
goto deliver;
/*
* Wait and block until (more) data comes in.
* NB: Drops the sockbuf lock during wait.
*/
error = sbwait(so, SO_RCV);
if (error)
goto out;
goto restart;
deliver:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
/* Statistics. */
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
/* Fill uio until full or current end of socket buffer is reached. */
len = min(uio->uio_resid, sbavail(sb));
if (mp0 != NULL) {
/* Dequeue as many mbufs as possible. */
if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
if (*mp0 == NULL)
*mp0 = sb->sb_mb;
else
m_cat(*mp0, sb->sb_mb);
for (m = sb->sb_mb;
m != NULL && m->m_len <= len;
m = m->m_next) {
KASSERT(!(m->m_flags & M_NOTREADY),
("%s: m %p not available", __func__, m));
len -= m->m_len;
uio->uio_resid -= m->m_len;
sbfree(sb, m);
n = m;
}
n->m_next = NULL;
sb->sb_mb = m;
sb->sb_lastrecord = sb->sb_mb;
if (sb->sb_mb == NULL)
SB_EMPTY_FIXUP(sb);
}
/* Copy the remainder. */
if (len > 0) {
KASSERT(sb->sb_mb != NULL,
("%s: len > 0 && sb->sb_mb empty", __func__));
m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
if (m == NULL)
len = 0; /* Don't flush data from sockbuf. */
else
uio->uio_resid -= len;
if (*mp0 != NULL)
m_cat(*mp0, m);
else
*mp0 = m;
if (*mp0 == NULL) {
error = ENOBUFS;
goto out;
}
}
} else {
/* NB: Must unlock socket buffer as uiomove may sleep. */
SOCKBUF_UNLOCK(sb);
error = m_mbuftouio(uio, sb->sb_mb, len);
SOCKBUF_LOCK(sb);
if (error)
goto out;
}
SBLASTRECORDCHK(sb);
SBLASTMBUFCHK(sb);
/*
* Remove the delivered data from the socket buffer unless we
* were only peeking.
*/
if (!(flags & MSG_PEEK)) {
if (len > 0)
sbdrop_locked(sb, len);
/* Notify protocol that we drained some data. */
if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
(((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
!(flags & MSG_SOCALLBCK))) {
SOCKBUF_UNLOCK(sb);
VNET_SO_ASSERT(so);
so->so_proto->pr_rcvd(so, flags);
SOCKBUF_LOCK(sb);
}
}
/*
* For MSG_WAITALL we may have to loop again and wait for
* more data to come in.
*/
if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
goto restart;
out:
SBLASTRECORDCHK(sb);
SBLASTMBUFCHK(sb);
SOCKBUF_UNLOCK(sb);
return (error);
}
int
soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
struct sockbuf *sb;
int error, flags;
sb = &so->so_rcv;
/* We only do stream sockets. */
if (so->so_type != SOCK_STREAM)
return (EINVAL);
if (psa != NULL)
*psa = NULL;
if (flagsp != NULL)
flags = *flagsp & ~MSG_EOR;
else
flags = 0;
if (controlp != NULL)
*controlp = NULL;
if (flags & MSG_OOB)
return (soreceive_rcvoob(so, uio, flags));
if (mp0 != NULL)
*mp0 = NULL;
#ifdef KERN_TLS
/*
* KTLS store TLS records as records with a control message to
* describe the framing.
*
* We check once here before acquiring locks to optimize the
* common case.
*/
if (sb->sb_tls_info != NULL)
return (soreceive_generic(so, psa, uio, mp0, controlp,
flagsp));
#endif
/*
* Prevent other threads from reading from the socket. This lock may be
* dropped in order to sleep waiting for data to arrive.
*/
error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
if (error)
return (error);
#ifdef KERN_TLS
if (__predict_false(sb->sb_tls_info != NULL)) {
SOCK_IO_RECV_UNLOCK(so);
return (soreceive_generic(so, psa, uio, mp0, controlp,
flagsp));
}
#endif
error = soreceive_stream_locked(so, sb, psa, uio, mp0, controlp, flags);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
/*
* Optimized version of soreceive() for simple datagram cases from userspace.
* Unlike in the stream case, we're able to drop a datagram if copyout()
* fails, and because we handle datagrams atomically, we don't need to use a
* sleep lock to prevent I/O interlacing.
*/
int
soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
struct mbuf *m, *m2;
int flags, error;
ssize_t len;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
if (flagsp != NULL)
flags = *flagsp &~ MSG_EOR;
else
flags = 0;
/*
* For any complicated cases, fall back to the full
* soreceive_generic().
*/
if (mp0 != NULL || (flags & (MSG_PEEK | MSG_OOB | MSG_TRUNC)))
return (soreceive_generic(so, psa, uio, mp0, controlp,
flagsp));
/*
* Enforce restrictions on use.
*/
KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
("soreceive_dgram: wantrcvd"));
KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
("soreceive_dgram: SBS_RCVATMARK"));
KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
("soreceive_dgram: P_CONNREQUIRED"));
/*
* Loop blocking while waiting for a datagram.
*/
SOCKBUF_LOCK(&so->so_rcv);
while ((m = so->so_rcv.sb_mb) == NULL) {
KASSERT(sbavail(&so->so_rcv) == 0,
("soreceive_dgram: sb_mb NULL but sbavail %u",
sbavail(&so->so_rcv)));
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_rcv);
return (error);
}
if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
uio->uio_resid == 0) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (0);
}
if ((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO))) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (EWOULDBLOCK);
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
error = sbwait(so, SO_RCV);
if (error) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (error);
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
nextrecord = m->m_nextpkt;
if (nextrecord == NULL) {
KASSERT(so->so_rcv.sb_lastrecord == m,
("soreceive_dgram: lastrecord != m"));
}
KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
("soreceive_dgram: m_nextpkt != nextrecord"));
/*
* Pull 'm' and its chain off the front of the packet queue.
*/
so->so_rcv.sb_mb = NULL;
sockbuf_pushsync(&so->so_rcv, nextrecord);
/*
* Walk 'm's chain and free that many bytes from the socket buffer.
*/
for (m2 = m; m2 != NULL; m2 = m2->m_next)
sbfree(&so->so_rcv, m2);
/*
* Do a few last checks before we let go of the lock.
*/
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
if (pr->pr_flags & PR_ADDR) {
KASSERT(m->m_type == MT_SONAME,
("m->m_type == %d", m->m_type));
if (psa != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *),
M_WAITOK);
m = m_free(m);
}
KASSERT(m, ("%s: no data or control after soname", __func__));
/*
* Packet to copyout() is now in 'm' and it is disconnected from the
* queue.
*
* Process one or more MT_CONTROL mbufs present before any data mbufs
* in the first mbuf chain on the socket buffer. We call into the
* protocol to perform externalization (or freeing if controlp ==
* NULL). In some cases there can be only MT_CONTROL mbufs without
* MT_DATA mbufs.
*/
if (m->m_type == MT_CONTROL) {
struct mbuf *cm = NULL, *cmn;
struct mbuf **cme = &cm;
do {
m2 = m->m_next;
m->m_next = NULL;
*cme = m;
cme = &(*cme)->m_next;
m = m2;
} while (m != NULL && m->m_type == MT_CONTROL);
while (cm != NULL) {
cmn = cm->m_next;
cm->m_next = NULL;
if (controlp != NULL)
*controlp = cm;
else
m_freem(cm);
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
cm = cmn;
}
}
KASSERT(m == NULL || m->m_type == MT_DATA,
("soreceive_dgram: !data"));
while (m != NULL && uio->uio_resid > 0) {
len = uio->uio_resid;
if (len > m->m_len)
len = m->m_len;
error = uiomove(mtod(m, char *), (int)len, uio);
if (error) {
m_freem(m);
return (error);
}
if (len == m->m_len)
m = m_free(m);
else {
m->m_data += len;
m->m_len -= len;
}
}
if (m != NULL) {
flags |= MSG_TRUNC;
m_freem(m);
}
if (flagsp != NULL)
*flagsp |= flags;
return (0);
}
int
soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_soreceive(so, psa, uio, mp0, controlp, flagsp);
CURVNET_RESTORE();
return (error);
}
int
soshutdown(struct socket *so, enum shutdown_how how)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_shutdown(so, how);
CURVNET_RESTORE();
return (error);
}
/*
* Used by several pr_shutdown implementations that use generic socket buffers.
*/
void
sorflush(struct socket *so)
{
int error;
VNET_SO_ASSERT(so);
/*
* Dislodge threads currently blocked in receive and wait to acquire
* a lock against other simultaneous readers before clearing the
* socket buffer. Don't let our acquire be interrupted by a signal
* despite any existing socket disposition on interruptable waiting.
*
* The SOCK_IO_RECV_LOCK() is important here as there some pr_soreceive
* methods that read the top of the socket buffer without acquisition
* of the socket buffer mutex, assuming that top of the buffer
* exclusively belongs to the read(2) syscall. This is handy when
* performing MSG_PEEK.
*/
socantrcvmore(so);
error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
if (error != 0) {
KASSERT(SOLISTENING(so),
("%s: soiolock(%p) failed", __func__, so));
return;
}
sbrelease(so, SO_RCV);
SOCK_IO_RECV_UNLOCK(so);
}
int
sosetfib(struct socket *so, int fibnum)
{
if (fibnum < 0 || fibnum >= rt_numfibs)
return (EINVAL);
SOCK_LOCK(so);
so->so_fibnum = fibnum;
SOCK_UNLOCK(so);
return (0);
}
#ifdef SOCKET_HHOOK
/*
* Wrapper for Socket established helper hook.
* Parameters: socket, context of the hook point, hook id.
*/
static inline int
hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
{
struct socket_hhook_data hhook_data = {
.so = so,
.hctx = hctx,
.m = NULL,
.status = 0
};
CURVNET_SET(so->so_vnet);
HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
CURVNET_RESTORE();
/* Ugly but needed, since hhooks return void for now */
return (hhook_data.status);
}
#endif
/*
* Perhaps this routine, and sooptcopyout(), below, ought to come in an
* additional variant to handle the case where the option value needs to be
* some kind of integer, but not a specific size. In addition to their use
* here, these functions are also called by the protocol-level pr_ctloutput()
* routines.
*/
int
sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
{
size_t valsize;
/*
* If the user gives us more than we wanted, we ignore it, but if we
* don't get the minimum length the caller wants, we return EINVAL.
* On success, sopt->sopt_valsize is set to however much we actually
* retrieved.
*/
if ((valsize = sopt->sopt_valsize) < minlen)
return EINVAL;
if (valsize > len)
sopt->sopt_valsize = valsize = len;
if (sopt->sopt_td != NULL)
return (copyin(sopt->sopt_val, buf, valsize));
bcopy(sopt->sopt_val, buf, valsize);
return (0);
}
/*
* Kernel version of setsockopt(2).
*
* XXX: optlen is size_t, not socklen_t
*/
int
so_setsockopt(struct socket *so, int level, int optname, void *optval,
size_t optlen)
{
struct sockopt sopt;
sopt.sopt_level = level;
sopt.sopt_name = optname;
sopt.sopt_dir = SOPT_SET;
sopt.sopt_val = optval;
sopt.sopt_valsize = optlen;
sopt.sopt_td = NULL;
return (sosetopt(so, &sopt));
}
int
sosetopt(struct socket *so, struct sockopt *sopt)
{
int error, optval;
struct linger l;
struct timeval tv;
sbintime_t val, *valp;
uint32_t val32;
#ifdef MAC
struct mac extmac;
#endif
CURVNET_SET(so->so_vnet);
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
error = so->so_proto->pr_ctloutput(so, sopt);
} else {
switch (sopt->sopt_name) {
case SO_ACCEPTFILTER:
error = accept_filt_setopt(so, sopt);
if (error)
goto bad;
break;
case SO_LINGER:
error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
if (error)
goto bad;
if (l.l_linger < 0 ||
l.l_linger > USHRT_MAX ||
l.l_linger > (INT_MAX / hz)) {
error = EDOM;
goto bad;
}
SOCK_LOCK(so);
so->so_linger = l.l_linger;
if (l.l_onoff)
so->so_options |= SO_LINGER;
else
so->so_options &= ~SO_LINGER;
SOCK_UNLOCK(so);
break;
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_DONTROUTE:
case SO_USELOOPBACK:
case SO_BROADCAST:
case SO_REUSEADDR:
case SO_REUSEPORT:
case SO_REUSEPORT_LB:
case SO_OOBINLINE:
case SO_TIMESTAMP:
case SO_BINTIME:
case SO_NOSIGPIPE:
case SO_NO_DDP:
case SO_NO_OFFLOAD:
case SO_RERROR:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
goto bad;
SOCK_LOCK(so);
if (optval)
so->so_options |= sopt->sopt_name;
else
so->so_options &= ~sopt->sopt_name;
SOCK_UNLOCK(so);
break;
case SO_SETFIB:
error = so->so_proto->pr_ctloutput(so, sopt);
break;
case SO_USER_COOKIE:
error = sooptcopyin(sopt, &val32, sizeof val32,
sizeof val32);
if (error)
goto bad;
so->so_user_cookie = val32;
break;
case SO_SNDBUF:
case SO_RCVBUF:
case SO_SNDLOWAT:
case SO_RCVLOWAT:
error = so->so_proto->pr_setsbopt(so, sopt);
if (error)
goto bad;
break;
case SO_SNDTIMEO:
case SO_RCVTIMEO:
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
struct timeval32 tv32;
error = sooptcopyin(sopt, &tv32, sizeof tv32,
sizeof tv32);
CP(tv32, tv, tv_sec);
CP(tv32, tv, tv_usec);
} else
#endif
error = sooptcopyin(sopt, &tv, sizeof tv,
sizeof tv);
if (error)
goto bad;
if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
tv.tv_usec >= 1000000) {
error = EDOM;
goto bad;
}
if (tv.tv_sec > INT32_MAX)
val = SBT_MAX;
else
val = tvtosbt(tv);
SOCK_LOCK(so);
valp = sopt->sopt_name == SO_SNDTIMEO ?
(SOLISTENING(so) ? &so->sol_sbsnd_timeo :
&so->so_snd.sb_timeo) :
(SOLISTENING(so) ? &so->sol_sbrcv_timeo :
&so->so_rcv.sb_timeo);
*valp = val;
SOCK_UNLOCK(so);
break;
case SO_LABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof extmac,
sizeof extmac);
if (error)
goto bad;
error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
so, &extmac);
#else
error = EOPNOTSUPP;
#endif
break;
case SO_TS_CLOCK:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
goto bad;
if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
error = EINVAL;
goto bad;
}
so->so_ts_clock = optval;
break;
case SO_MAX_PACING_RATE:
error = sooptcopyin(sopt, &val32, sizeof(val32),
sizeof(val32));
if (error)
goto bad;
so->so_max_pacing_rate = val32;
break;
case SO_SPLICE: {
struct splice splice;
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
struct splice32 splice32;
error = sooptcopyin(sopt, &splice32,
sizeof(splice32), sizeof(splice32));
if (error == 0) {
splice.sp_fd = splice32.sp_fd;
splice.sp_max = splice32.sp_max;
CP(splice32.sp_idle, splice.sp_idle,
tv_sec);
CP(splice32.sp_idle, splice.sp_idle,
tv_usec);
}
} else
#endif
{
error = sooptcopyin(sopt, &splice,
sizeof(splice), sizeof(splice));
}
if (error)
goto bad;
#ifdef KTRACE
if (KTRPOINT(curthread, KTR_STRUCT))
ktrsplice(&splice);
#endif
error = splice_init();
if (error != 0)
goto bad;
if (splice.sp_fd >= 0) {
struct file *fp;
struct socket *so2;
if (!cap_rights_contains(sopt->sopt_rights,
&cap_recv_rights)) {
error = ENOTCAPABLE;
goto bad;
}
error = getsock(sopt->sopt_td, splice.sp_fd,
&cap_send_rights, &fp);
if (error != 0)
goto bad;
so2 = fp->f_data;
error = so_splice(so, so2, &splice);
fdrop(fp, sopt->sopt_td);
} else {
error = so_unsplice(so, false);
}
break;
}
default:
#ifdef SOCKET_HHOOK
if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
error = hhook_run_socket(so, sopt,
HHOOK_SOCKET_OPT);
else
#endif
error = ENOPROTOOPT;
break;
}
if (error == 0)
(void)so->so_proto->pr_ctloutput(so, sopt);
}
bad:
CURVNET_RESTORE();
return (error);
}
/*
* Helper routine for getsockopt.
*/
int
sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
{
int error;
size_t valsize;
error = 0;
/*
* Documented get behavior is that we always return a value, possibly
* truncated to fit in the user's buffer. Traditional behavior is
* that we always tell the user precisely how much we copied, rather
* than something useful like the total amount we had available for
* her. Note that this interface is not idempotent; the entire
* answer must be generated ahead of time.
*/
valsize = min(len, sopt->sopt_valsize);
sopt->sopt_valsize = valsize;
if (sopt->sopt_val != NULL) {
if (sopt->sopt_td != NULL)
error = copyout(buf, sopt->sopt_val, valsize);
else
bcopy(buf, sopt->sopt_val, valsize);
}
return (error);
}
int
sogetopt(struct socket *so, struct sockopt *sopt)
{
int error, optval;
struct linger l;
struct timeval tv;
#ifdef MAC
struct mac extmac;
#endif
CURVNET_SET(so->so_vnet);
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
error = so->so_proto->pr_ctloutput(so, sopt);
CURVNET_RESTORE();
return (error);
} else {
switch (sopt->sopt_name) {
case SO_ACCEPTFILTER:
error = accept_filt_getopt(so, sopt);
break;
case SO_LINGER:
SOCK_LOCK(so);
l.l_onoff = so->so_options & SO_LINGER;
l.l_linger = so->so_linger;
SOCK_UNLOCK(so);
error = sooptcopyout(sopt, &l, sizeof l);
break;
case SO_USELOOPBACK:
case SO_DONTROUTE:
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_REUSEADDR:
case SO_REUSEPORT:
case SO_REUSEPORT_LB:
case SO_BROADCAST:
case SO_OOBINLINE:
case SO_ACCEPTCONN:
case SO_TIMESTAMP:
case SO_BINTIME:
case SO_NOSIGPIPE:
case SO_NO_DDP:
case SO_NO_OFFLOAD:
case SO_RERROR:
optval = so->so_options & sopt->sopt_name;
integer:
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case SO_FIB:
SOCK_LOCK(so);
optval = so->so_fibnum;
SOCK_UNLOCK(so);
goto integer;
case SO_DOMAIN:
optval = so->so_proto->pr_domain->dom_family;
goto integer;
case SO_TYPE:
optval = so->so_type;
goto integer;
case SO_PROTOCOL:
optval = so->so_proto->pr_protocol;
goto integer;
case SO_ERROR:
SOCK_LOCK(so);
if (so->so_error) {
optval = so->so_error;
so->so_error = 0;
} else {
optval = so->so_rerror;
so->so_rerror = 0;
}
SOCK_UNLOCK(so);
goto integer;
case SO_SNDBUF:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_sbsnd_hiwat :
so->so_snd.sb_hiwat;
SOCK_UNLOCK(so);
goto integer;
case SO_RCVBUF:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_sbrcv_hiwat :
so->so_rcv.sb_hiwat;
SOCK_UNLOCK(so);
goto integer;
case SO_SNDLOWAT:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_sbsnd_lowat :
so->so_snd.sb_lowat;
SOCK_UNLOCK(so);
goto integer;
case SO_RCVLOWAT:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_sbrcv_lowat :
so->so_rcv.sb_lowat;
SOCK_UNLOCK(so);
goto integer;
case SO_SNDTIMEO:
case SO_RCVTIMEO:
SOCK_LOCK(so);
tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
(SOLISTENING(so) ? so->sol_sbsnd_timeo :
so->so_snd.sb_timeo) :
(SOLISTENING(so) ? so->sol_sbrcv_timeo :
so->so_rcv.sb_timeo));
SOCK_UNLOCK(so);
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
struct timeval32 tv32;
CP(tv, tv32, tv_sec);
CP(tv, tv32, tv_usec);
error = sooptcopyout(sopt, &tv32, sizeof tv32);
} else
#endif
error = sooptcopyout(sopt, &tv, sizeof tv);
break;
case SO_LABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof(extmac),
sizeof(extmac));
if (error)
goto bad;
error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
so, &extmac);
if (error)
goto bad;
/* Don't copy out extmac, it is unchanged. */
#else
error = EOPNOTSUPP;
#endif
break;
case SO_PEERLABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof(extmac),
sizeof(extmac));
if (error)
goto bad;
error = mac_getsockopt_peerlabel(
sopt->sopt_td->td_ucred, so, &extmac);
if (error)
goto bad;
/* Don't copy out extmac, it is unchanged. */
#else
error = EOPNOTSUPP;
#endif
break;
case SO_LISTENQLIMIT:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_qlimit : 0;
SOCK_UNLOCK(so);
goto integer;
case SO_LISTENQLEN:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_qlen : 0;
SOCK_UNLOCK(so);
goto integer;
case SO_LISTENINCQLEN:
SOCK_LOCK(so);
optval = SOLISTENING(so) ? so->sol_incqlen : 0;
SOCK_UNLOCK(so);
goto integer;
case SO_TS_CLOCK:
optval = so->so_ts_clock;
goto integer;
case SO_MAX_PACING_RATE:
optval = so->so_max_pacing_rate;
goto integer;
case SO_SPLICE: {
off_t n;
/*
* Acquire the I/O lock to serialize with
* so_splice_xfer(). This is not required for
* correctness, but makes testing simpler: once a byte
* has been transmitted to the sink and observed (e.g.,
* by reading from the socket to which the sink is
* connected), a subsequent getsockopt(SO_SPLICE) will
* return an up-to-date value.
*/
error = SOCK_IO_RECV_LOCK(so, SBL_WAIT);
if (error != 0)
goto bad;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
n = 0;
} else {
n = so->so_splice_sent;
}
SOCK_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
error = sooptcopyout(sopt, &n, sizeof(n));
break;
}
default:
#ifdef SOCKET_HHOOK
if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
error = hhook_run_socket(so, sopt,
HHOOK_SOCKET_OPT);
else
#endif
error = ENOPROTOOPT;
break;
}
}
bad:
CURVNET_RESTORE();
return (error);
}
int
soopt_getm(struct sockopt *sopt, struct mbuf **mp)
{
struct mbuf *m, *m_prev;
int sopt_size = sopt->sopt_valsize;
MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return ENOBUFS;
}
m->m_len = min(MCLBYTES, sopt_size);
} else {
m->m_len = min(MLEN, sopt_size);
}
sopt_size -= m->m_len;
*mp = m;
m_prev = m;
while (sopt_size) {
MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
if (m == NULL) {
m_freem(*mp);
return ENOBUFS;
}
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
M_NOWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_freem(m);
m_freem(*mp);
return ENOBUFS;
}
m->m_len = min(MCLBYTES, sopt_size);
} else {
m->m_len = min(MLEN, sopt_size);
}
sopt_size -= m->m_len;
m_prev->m_next = m;
m_prev = m;
}
return (0);
}
int
soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
{
struct mbuf *m0 = m;
if (sopt->sopt_val == NULL)
return (0);
while (m != NULL && sopt->sopt_valsize >= m->m_len) {
if (sopt->sopt_td != NULL) {
int error;
error = copyin(sopt->sopt_val, mtod(m, char *),
m->m_len);
if (error != 0) {
m_freem(m0);
return(error);
}
} else
bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
sopt->sopt_valsize -= m->m_len;
sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
m = m->m_next;
}
if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
panic("ip6_sooptmcopyin");
return (0);
}
int
soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
{
struct mbuf *m0 = m;
size_t valsize = 0;
if (sopt->sopt_val == NULL)
return (0);
while (m != NULL && sopt->sopt_valsize >= m->m_len) {
if (sopt->sopt_td != NULL) {
int error;
error = copyout(mtod(m, char *), sopt->sopt_val,
m->m_len);
if (error != 0) {
m_freem(m0);
return(error);
}
} else
bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
sopt->sopt_valsize -= m->m_len;
sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
valsize += m->m_len;
m = m->m_next;
}
if (m != NULL) {
/* enough soopt buffer should be given from user-land */
m_freem(m0);
return(EINVAL);
}
sopt->sopt_valsize = valsize;
return (0);
}
/*
* sohasoutofband(): protocol notifies socket layer of the arrival of new
* out-of-band data, which will then notify socket consumers.
*/
void
sohasoutofband(struct socket *so)
{
if (so->so_sigio != NULL)
pgsigio(&so->so_sigio, SIGURG, 0);
selwakeuppri(&so->so_rdsel, PSOCK);
}
int
sopoll_generic(struct socket *so, int events, struct thread *td)
{
int revents;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
if (!(events & (POLLIN | POLLRDNORM)))
revents = 0;
else if (!TAILQ_EMPTY(&so->sol_comp))
revents = events & (POLLIN | POLLRDNORM);
else if ((events & POLLINIGNEOF) == 0 && so->so_error)
revents = (events & (POLLIN | POLLRDNORM)) | POLLHUP;
else {
selrecord(td, &so->so_rdsel);
revents = 0;
}
} else {
revents = 0;
SOCK_SENDBUF_LOCK(so);
SOCK_RECVBUF_LOCK(so);
if (events & (POLLIN | POLLRDNORM))
if (soreadabledata(so) && !isspliced(so))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (sowriteable(so) && !issplicedback(so))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & (POLLPRI | POLLRDBAND))
if (so->so_oobmark ||
(so->so_rcv.sb_state & SBS_RCVATMARK))
revents |= events & (POLLPRI | POLLRDBAND);
if ((events & POLLINIGNEOF) == 0) {
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
revents |= events & (POLLIN | POLLRDNORM);
if (so->so_snd.sb_state & SBS_CANTSENDMORE)
revents |= POLLHUP;
}
}
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
revents |= events & POLLRDHUP;
if (revents == 0) {
if (events &
(POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND | POLLRDHUP)) {
selrecord(td, &so->so_rdsel);
so->so_rcv.sb_flags |= SB_SEL;
}
if (events & (POLLOUT | POLLWRNORM)) {
selrecord(td, &so->so_wrsel);
so->so_snd.sb_flags |= SB_SEL;
}
}
SOCK_RECVBUF_UNLOCK(so);
SOCK_SENDBUF_UNLOCK(so);
}
SOCK_UNLOCK(so);
return (revents);
}
int
sokqfilter_generic(struct socket *so, struct knote *kn)
{
struct sockbuf *sb;
sb_which which;
struct knlist *knl;
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &soread_filtops;
knl = &so->so_rdsel.si_note;
sb = &so->so_rcv;
which = SO_RCV;
break;
case EVFILT_WRITE:
kn->kn_fop = &sowrite_filtops;
knl = &so->so_wrsel.si_note;
sb = &so->so_snd;
which = SO_SND;
break;
case EVFILT_EMPTY:
kn->kn_fop = &soempty_filtops;
knl = &so->so_wrsel.si_note;
sb = &so->so_snd;
which = SO_SND;
break;
default:
return (EINVAL);
}
SOCK_LOCK(so);
if (SOLISTENING(so)) {
knlist_add(knl, kn, 1);
} else {
SOCK_BUF_LOCK(so, which);
knlist_add(knl, kn, 1);
sb->sb_flags |= SB_KNOTE;
if ((kn->kn_sfflags & NOTE_LOWAT) &&
(sb->sb_flags & SB_AUTOLOWAT))
sb->sb_flags &= ~SB_AUTOLOWAT;
SOCK_BUF_UNLOCK(so, which);
}
SOCK_UNLOCK(so);
return (0);
}
static void
filt_sordetach(struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
so_rdknl_lock(so);
knlist_remove(&so->so_rdsel.si_note, kn, 1);
if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
so->so_rcv.sb_flags &= ~SB_KNOTE;
so_rdknl_unlock(so);
}
/*ARGSUSED*/
static int
filt_soread(struct knote *kn, long hint)
{
struct socket *so;
so = kn->kn_fp->f_data;
if (SOLISTENING(so)) {
SOCK_LOCK_ASSERT(so);
kn->kn_data = so->sol_qlen;
if (so->so_error) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
}
return (!TAILQ_EMPTY(&so->sol_comp));
}
if ((so->so_rcv.sb_flags & SB_SPLICED) != 0)
return (0);
SOCK_RECVBUF_LOCK_ASSERT(so);
kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
} else if (so->so_error || so->so_rerror)
return (1);
if (kn->kn_sfflags & NOTE_LOWAT) {
if (kn->kn_data >= kn->kn_sdata)
return (1);
} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
return (1);
#ifdef SOCKET_HHOOK
/* This hook returning non-zero indicates an event, not error */
return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
#else
return (0);
#endif
}
static void
filt_sowdetach(struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
so_wrknl_lock(so);
knlist_remove(&so->so_wrsel.si_note, kn, 1);
if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
so->so_snd.sb_flags &= ~SB_KNOTE;
so_wrknl_unlock(so);
}
/*ARGSUSED*/
static int
filt_sowrite(struct knote *kn, long hint)
{
struct socket *so;
so = kn->kn_fp->f_data;
if (SOLISTENING(so))
return (0);
SOCK_SENDBUF_LOCK_ASSERT(so);
kn->kn_data = sbspace(&so->so_snd);
#ifdef SOCKET_HHOOK
hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
#endif
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
} else if (so->so_error) /* temporary udp error */
return (1);
else if (((so->so_state & SS_ISCONNECTED) == 0) &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
return (0);
else if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
else
return (kn->kn_data >= so->so_snd.sb_lowat);
}
static int
filt_soempty(struct knote *kn, long hint)
{
struct socket *so;
so = kn->kn_fp->f_data;
if (SOLISTENING(so))
return (1);
SOCK_SENDBUF_LOCK_ASSERT(so);
kn->kn_data = sbused(&so->so_snd);
if (kn->kn_data == 0)
return (1);
else
return (0);
}
int
socheckuid(struct socket *so, uid_t uid)
{
if (so == NULL)
return (EPERM);
if (so->so_cred->cr_uid != uid)
return (EPERM);
return (0);
}
/*
* These functions are used by protocols to notify the socket layer (and its
* consumers) of state changes in the sockets driven by protocol-side events.
*/
/*
* Procedures to manipulate state flags of socket and do appropriate wakeups.
*
* Normal sequence from the active (originating) side is that
* soisconnecting() is called during processing of connect() call, resulting
* in an eventual call to soisconnected() if/when the connection is
* established. When the connection is torn down soisdisconnecting() is
* called during processing of disconnect() call, and soisdisconnected() is
* called when the connection to the peer is totally severed. The semantics
* of these routines are such that connectionless protocols can call
* soisconnected() and soisdisconnected() only, bypassing the in-progress
* calls when setting up a ``connection'' takes no time.
*
* From the passive side, a socket is created with two queues of sockets:
* so_incomp for connections in progress and so_comp for connections already
* made and awaiting user acceptance. As a protocol is preparing incoming
* connections, it creates a socket structure queued on so_incomp by calling
* sonewconn(). When the connection is established, soisconnected() is
* called, and transfers the socket structure to so_comp, making it available
* to accept().
*
* If a socket is closed with sockets on either so_incomp or so_comp, these
* sockets are dropped.
*
* If higher-level protocols are implemented in the kernel, the wakeups done
* here will sometimes cause software-interrupt process scheduling.
*/
void
soisconnecting(struct socket *so)
{
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTING;
SOCK_UNLOCK(so);
}
void
soisconnected(struct socket *so)
{
bool last __diagused;
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTED;
if (so->so_qstate == SQ_INCOMP) {
struct socket *head = so->so_listen;
int ret;
KASSERT(head, ("%s: so %p on incomp of NULL", __func__, so));
/*
* Promoting a socket from incomplete queue to complete, we
* need to go through reverse order of locking. We first do
* trylock, and if that doesn't succeed, we go the hard way
* leaving a reference and rechecking consistency after proper
* locking.
*/
if (__predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
soref(head);
SOCK_UNLOCK(so);
SOLISTEN_LOCK(head);
SOCK_LOCK(so);
if (__predict_false(head != so->so_listen)) {
/*
* The socket went off the listen queue,
* should be lost race to close(2) of sol.
* The socket is about to soabort().
*/
SOCK_UNLOCK(so);
sorele_locked(head);
return;
}
last = refcount_release(&head->so_count);
KASSERT(!last, ("%s: released last reference for %p",
__func__, head));
}
again:
if ((so->so_options & SO_ACCEPTFILTER) == 0) {
TAILQ_REMOVE(&head->sol_incomp, so, so_list);
head->sol_incqlen--;
TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
head->sol_qlen++;
so->so_qstate = SQ_COMP;
SOCK_UNLOCK(so);
solisten_wakeup(head); /* unlocks */
} else {
SOCK_RECVBUF_LOCK(so);
soupcall_set(so, SO_RCV,
head->sol_accept_filter->accf_callback,
head->sol_accept_filter_arg);
so->so_options &= ~SO_ACCEPTFILTER;
ret = head->sol_accept_filter->accf_callback(so,
head->sol_accept_filter_arg, M_NOWAIT);
if (ret == SU_ISCONNECTED) {
soupcall_clear(so, SO_RCV);
SOCK_RECVBUF_UNLOCK(so);
goto again;
}
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
SOLISTEN_UNLOCK(head);
}
return;
}
SOCK_UNLOCK(so);
wakeup(&so->so_timeo);
sorwakeup(so);
sowwakeup(so);
}
void
soisdisconnecting(struct socket *so)
{
SOCK_LOCK(so);
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= SS_ISDISCONNECTING;
if (!SOLISTENING(so)) {
SOCK_RECVBUF_LOCK(so);
socantrcvmore_locked(so);
SOCK_SENDBUF_LOCK(so);
socantsendmore_locked(so);
}
SOCK_UNLOCK(so);
wakeup(&so->so_timeo);
}
void
soisdisconnected(struct socket *so)
{
SOCK_LOCK(so);
/*
* There is at least one reader of so_state that does not
* acquire socket lock, namely soreceive_generic(). Ensure
* that it never sees all flags that track connection status
* cleared, by ordering the update with a barrier semantic of
* our release thread fence.
*/
so->so_state |= SS_ISDISCONNECTED;
atomic_thread_fence_rel();
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
if (!SOLISTENING(so)) {
SOCK_UNLOCK(so);
SOCK_RECVBUF_LOCK(so);
socantrcvmore_locked(so);
SOCK_SENDBUF_LOCK(so);
sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
socantsendmore_locked(so);
} else
SOCK_UNLOCK(so);
wakeup(&so->so_timeo);
}
int
soiolock(struct socket *so, struct sx *sx, int flags)
{
int error;
KASSERT((flags & SBL_VALID) == flags,
("soiolock: invalid flags %#x", flags));
if ((flags & SBL_WAIT) != 0) {
if ((flags & SBL_NOINTR) != 0) {
sx_xlock(sx);
} else {
error = sx_xlock_sig(sx);
if (error != 0)
return (error);
}
} else if (!sx_try_xlock(sx)) {
return (EWOULDBLOCK);
}
if (__predict_false(SOLISTENING(so))) {
sx_xunlock(sx);
return (ENOTCONN);
}
return (0);
}
void
soiounlock(struct sx *sx)
{
sx_xunlock(sx);
}
/*
* Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
*/
struct sockaddr *
sodupsockaddr(const struct sockaddr *sa, int mflags)
{
struct sockaddr *sa2;
sa2 = malloc(sa->sa_len, M_SONAME, mflags);
if (sa2)
bcopy(sa, sa2, sa->sa_len);
return sa2;
}
/*
* Register per-socket destructor.
*/
void
sodtor_set(struct socket *so, so_dtor_t *func)
{
SOCK_LOCK_ASSERT(so);
so->so_dtor = func;
}
/*
* Register per-socket buffer upcalls.
*/
void
soupcall_set(struct socket *so, sb_which which, so_upcall_t func, void *arg)
{
struct sockbuf *sb;
KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
switch (which) {
case SO_RCV:
sb = &so->so_rcv;
break;
case SO_SND:
sb = &so->so_snd;
break;
}
SOCK_BUF_LOCK_ASSERT(so, which);
sb->sb_upcall = func;
sb->sb_upcallarg = arg;
sb->sb_flags |= SB_UPCALL;
}
void
soupcall_clear(struct socket *so, sb_which which)
{
struct sockbuf *sb;
KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
switch (which) {
case SO_RCV:
sb = &so->so_rcv;
break;
case SO_SND:
sb = &so->so_snd;
break;
}
SOCK_BUF_LOCK_ASSERT(so, which);
KASSERT(sb->sb_upcall != NULL,
("%s: so %p no upcall to clear", __func__, so));
sb->sb_upcall = NULL;
sb->sb_upcallarg = NULL;
sb->sb_flags &= ~SB_UPCALL;
}
void
solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
{
SOLISTEN_LOCK_ASSERT(so);
so->sol_upcall = func;
so->sol_upcallarg = arg;
}
static void
so_rdknl_lock(void *arg)
{
struct socket *so = arg;
retry:
if (SOLISTENING(so)) {
SOLISTEN_LOCK(so);
} else {
SOCK_RECVBUF_LOCK(so);
if (__predict_false(SOLISTENING(so))) {
SOCK_RECVBUF_UNLOCK(so);
goto retry;
}
}
}
static void
so_rdknl_unlock(void *arg)
{
struct socket *so = arg;
if (SOLISTENING(so))
SOLISTEN_UNLOCK(so);
else
SOCK_RECVBUF_UNLOCK(so);
}
static void
so_rdknl_assert_lock(void *arg, int what)
{
struct socket *so = arg;
if (what == LA_LOCKED) {
if (SOLISTENING(so))
SOLISTEN_LOCK_ASSERT(so);
else
SOCK_RECVBUF_LOCK_ASSERT(so);
} else {
if (SOLISTENING(so))
SOLISTEN_UNLOCK_ASSERT(so);
else
SOCK_RECVBUF_UNLOCK_ASSERT(so);
}
}
static void
so_wrknl_lock(void *arg)
{
struct socket *so = arg;
retry:
if (SOLISTENING(so)) {
SOLISTEN_LOCK(so);
} else {
SOCK_SENDBUF_LOCK(so);
if (__predict_false(SOLISTENING(so))) {
SOCK_SENDBUF_UNLOCK(so);
goto retry;
}
}
}
static void
so_wrknl_unlock(void *arg)
{
struct socket *so = arg;
if (SOLISTENING(so))
SOLISTEN_UNLOCK(so);
else
SOCK_SENDBUF_UNLOCK(so);
}
static void
so_wrknl_assert_lock(void *arg, int what)
{
struct socket *so = arg;
if (what == LA_LOCKED) {
if (SOLISTENING(so))
SOLISTEN_LOCK_ASSERT(so);
else
SOCK_SENDBUF_LOCK_ASSERT(so);
} else {
if (SOLISTENING(so))
SOLISTEN_UNLOCK_ASSERT(so);
else
SOCK_SENDBUF_UNLOCK_ASSERT(so);
}
}
/*
* Create an external-format (``xsocket'') structure using the information in
* the kernel-format socket structure pointed to by so. This is done to
* reduce the spew of irrelevant information over this interface, to isolate
* user code from changes in the kernel structure, and potentially to provide
* information-hiding if we decide that some of this information should be
* hidden from users.
*/
void
sotoxsocket(struct socket *so, struct xsocket *xso)
{
bzero(xso, sizeof(*xso));
xso->xso_len = sizeof *xso;
xso->xso_so = (uintptr_t)so;
xso->so_type = so->so_type;
xso->so_options = so->so_options;
xso->so_linger = so->so_linger;
xso->so_state = so->so_state;
xso->so_pcb = (uintptr_t)so->so_pcb;
xso->xso_protocol = so->so_proto->pr_protocol;
xso->xso_family = so->so_proto->pr_domain->dom_family;
xso->so_timeo = so->so_timeo;
xso->so_error = so->so_error;
xso->so_uid = so->so_cred->cr_uid;
xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
SOCK_LOCK(so);
xso->so_fibnum = so->so_fibnum;
if (SOLISTENING(so)) {
xso->so_qlen = so->sol_qlen;
xso->so_incqlen = so->sol_incqlen;
xso->so_qlimit = so->sol_qlimit;
xso->so_oobmark = 0;
} else {
xso->so_state |= so->so_qstate;
xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
xso->so_oobmark = so->so_oobmark;
sbtoxsockbuf(&so->so_snd, &xso->so_snd);
sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
if ((so->so_rcv.sb_flags & SB_SPLICED) != 0)
xso->so_splice_so = (uintptr_t)so->so_splice->dst;
}
SOCK_UNLOCK(so);
}
int
so_options_get(const struct socket *so)
{
return (so->so_options);
}
void
so_options_set(struct socket *so, int val)
{
so->so_options = val;
}
int
so_error_get(const struct socket *so)
{
return (so->so_error);
}
void
so_error_set(struct socket *so, int val)
{
so->so_error = val;
}
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 60736af5adf6..d56aac883d9c 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1,4617 +1,4616 @@
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California. All Rights Reserved.
* Copyright (c) 2004-2009 Robert N. M. Watson All Rights Reserved.
* Copyright (c) 2018 Matthew Macy
* Copyright (c) 2022-2025 Gleb Smirnoff <glebius@FreeBSD.org>
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
/*
* UNIX Domain (Local) Sockets
*
* This is an implementation of UNIX (local) domain sockets. Each socket has
* an associated struct unpcb (UNIX protocol control block). Stream sockets
* may be connected to 0 or 1 other socket. Datagram sockets may be
* connected to 0, 1, or many other sockets. Sockets may be created and
* connected in pairs (socketpair(2)), or bound/connected to using the file
* system name space. For most purposes, only the receive socket buffer is
* used, as sending on one socket delivers directly to the receive socket
* buffer of a second socket.
*
* The implementation is substantially complicated by the fact that
* "ancillary data", such as file descriptors or credentials, may be passed
* across UNIX domain sockets. The potential for passing UNIX domain sockets
* over other UNIX domain sockets requires the implementation of a simple
* garbage collector to find and tear down cycles of disconnected sockets.
*
* TODO:
* RDM
* rethink name space problems
* need a proper out-of-band
*/
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/domain.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/queue.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/taskqueue.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/vnode.h>
#include <net/vnet.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#include <security/mac/mac_framework.h>
#include <vm/uma.h>
MALLOC_DECLARE(M_FILECAPS);
static struct domain localdomain;
static uma_zone_t unp_zone;
static unp_gen_t unp_gencnt; /* (l) */
static u_int unp_count; /* (l) Count of local sockets. */
static ino_t unp_ino; /* Prototype for fake inode numbers. */
static int unp_rights; /* (g) File descriptors in flight. */
static struct unp_head unp_shead; /* (l) List of stream sockets. */
static struct unp_head unp_dhead; /* (l) List of datagram sockets. */
static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */
static struct mtx_pool *unp_vp_mtxpool;
struct unp_defer {
SLIST_ENTRY(unp_defer) ud_link;
struct file *ud_fp;
};
static SLIST_HEAD(, unp_defer) unp_defers;
static int unp_defers_count;
static const struct sockaddr sun_noname = {
.sa_len = sizeof(sun_noname),
.sa_family = AF_LOCAL,
};
/*
* Garbage collection of cyclic file descriptor/socket references occurs
* asynchronously in a taskqueue context in order to avoid recursion and
* reentrance in the UNIX domain socket, file descriptor, and socket layer
* code. See unp_gc() for a full description.
*/
static struct timeout_task unp_gc_task;
/*
* The close of unix domain sockets attached as SCM_RIGHTS is
* postponed to the taskqueue, to avoid arbitrary recursion depth.
* The attached sockets might have another sockets attached.
*/
static struct task unp_defer_task;
/*
* SOCK_STREAM and SOCK_SEQPACKET unix(4) sockets fully bypass the send buffer,
* however the notion of send buffer still makes sense with them. Its size is
* the amount of space that a send(2) syscall may copyin(9) before checking
* with the receive buffer of a peer. Although not linked anywhere yet,
* pointed to by a stack variable, effectively it is a buffer that needs to be
* sized.
*
* SOCK_DGRAM sockets really use the sendspace as the maximum datagram size,
* and don't really want to reserve the sendspace. Their recvspace should be
* large enough for at least one max-size datagram plus address.
*/
static u_long unpst_sendspace = 64*1024;
static u_long unpst_recvspace = 64*1024;
static u_long unpdg_maxdgram = 8*1024; /* support 8KB syslog msgs */
static u_long unpdg_recvspace = 16*1024;
static u_long unpsp_sendspace = 64*1024;
static u_long unpsp_recvspace = 64*1024;
static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Local domain");
static SYSCTL_NODE(_net_local, SOCK_STREAM, stream,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"SOCK_STREAM");
static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"SOCK_DGRAM");
static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"SOCK_SEQPACKET");
SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
&unpst_sendspace, 0, "Default stream send space.");
SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
&unpst_recvspace, 0, "Default stream receive space.");
SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
&unpdg_maxdgram, 0, "Maximum datagram size.");
SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
&unpdg_recvspace, 0, "Default datagram receive space.");
SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW,
&unpsp_sendspace, 0, "Default seqpacket send space.");
SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW,
&unpsp_recvspace, 0, "Default seqpacket receive space.");
SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
"File descriptors in flight.");
SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
&unp_defers_count, 0,
"File descriptors deferred to taskqueue for close.");
/*
* Locking and synchronization:
*
* Several types of locks exist in the local domain socket implementation:
* - a global linkage lock
* - a global connection list lock
* - the mtxpool lock
* - per-unpcb mutexes
*
* The linkage lock protects the global socket lists, the generation number
* counter and garbage collector state.
*
* The connection list lock protects the list of referring sockets in a datagram
* socket PCB. This lock is also overloaded to protect a global list of
* sockets whose buffers contain socket references in the form of SCM_RIGHTS
* messages. To avoid recursion, such references are released by a dedicated
* thread.
*
* The mtxpool lock protects the vnode from being modified while referenced.
* Lock ordering rules require that it be acquired before any PCB locks.
*
* The unpcb lock (unp_mtx) protects the most commonly referenced fields in the
* unpcb. This includes the unp_conn field, which either links two connected
* PCBs together (for connected socket types) or points at the destination
* socket (for connectionless socket types). The operations of creating or
* destroying a connection therefore involve locking multiple PCBs. To avoid
* lock order reversals, in some cases this involves dropping a PCB lock and
* using a reference counter to maintain liveness.
*
* UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
* allocated in pr_attach() and freed in pr_detach(). The validity of that
* pointer is an invariant, so no lock is required to dereference the so_pcb
* pointer if a valid socket reference is held by the caller. In practice,
* this is always true during operations performed on a socket. Each unpcb
* has a back-pointer to its socket, unp_socket, which will be stable under
* the same circumstances.
*
* This pointer may only be safely dereferenced as long as a valid reference
* to the unpcb is held. Typically, this reference will be from the socket,
* or from another unpcb when the referring unpcb's lock is held (in order
* that the reference not be invalidated during use). For example, to follow
* unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee
* that detach is not run clearing unp_socket.
*
* Blocking with UNIX domain sockets is a tricky issue: unlike most network
* protocols, bind() is a non-atomic operation, and connect() requires
* potential sleeping in the protocol, due to potentially waiting on local or
* distributed file systems. We try to separate "lookup" operations, which
* may sleep, and the IPC operations themselves, which typically can occur
* with relative atomicity as locks can be held over the entire operation.
*
* Another tricky issue is simultaneous multi-threaded or multi-process
* access to a single UNIX domain socket. These are handled by the flags
* UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
* binding, both of which involve dropping UNIX domain socket locks in order
* to perform namei() and other file system operations.
*/
static struct rwlock unp_link_rwlock;
static struct mtx unp_defers_lock;
#define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \
"unp_link_rwlock")
#define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \
RA_LOCKED)
#define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
RA_UNLOCKED)
#define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock)
#define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock)
#define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock)
#define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock)
#define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
RA_WLOCKED)
#define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock)
#define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \
"unp_defer", NULL, MTX_DEF)
#define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock)
#define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock)
#define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK();
#define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK();
#define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \
"unp", "unp", \
MTX_DUPOK|MTX_DEF)
#define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx)
#define UNP_PCB_LOCKPTR(unp) (&(unp)->unp_mtx)
#define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx)
#define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx)
#define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx)
#define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx)
#define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED)
#define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED)
static int uipc_connect2(struct socket *, struct socket *);
static int uipc_ctloutput(struct socket *, struct sockopt *);
static int unp_connect(struct socket *, struct sockaddr *,
struct thread *);
static int unp_connectat(int, struct socket *, struct sockaddr *,
struct thread *, bool);
static void unp_connect2(struct socket *, struct socket *, bool);
static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
static void unp_dispose(struct socket *so);
static void unp_drop(struct unpcb *);
static void unp_gc(__unused void *, int);
static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
static void unp_discard(struct file *);
static void unp_freerights(struct filedescent **, int);
static int unp_internalize(struct mbuf *, struct mchain *,
struct thread *);
static void unp_internalize_fp(struct file *);
static int unp_externalize(struct mbuf *, struct mbuf **, int);
static int unp_externalize_fp(struct file *);
static void unp_addsockcred(struct thread *, struct mchain *, int);
static void unp_process_defers(void * __unused, int);
static void uipc_wrknl_lock(void *);
static void uipc_wrknl_unlock(void *);
static void uipc_wrknl_assert_lock(void *, int);
static void
unp_pcb_hold(struct unpcb *unp)
{
u_int old __unused;
old = refcount_acquire(&unp->unp_refcount);
KASSERT(old > 0, ("%s: unpcb %p has no references", __func__, unp));
}
static __result_use_check bool
unp_pcb_rele(struct unpcb *unp)
{
bool ret;
UNP_PCB_LOCK_ASSERT(unp);
if ((ret = refcount_release(&unp->unp_refcount))) {
UNP_PCB_UNLOCK(unp);
UNP_PCB_LOCK_DESTROY(unp);
uma_zfree(unp_zone, unp);
}
return (ret);
}
static void
unp_pcb_rele_notlast(struct unpcb *unp)
{
bool ret __unused;
ret = refcount_release(&unp->unp_refcount);
KASSERT(!ret, ("%s: unpcb %p has no references", __func__, unp));
}
static void
unp_pcb_lock_pair(struct unpcb *unp, struct unpcb *unp2)
{
UNP_PCB_UNLOCK_ASSERT(unp);
UNP_PCB_UNLOCK_ASSERT(unp2);
if (unp == unp2) {
UNP_PCB_LOCK(unp);
} else if ((uintptr_t)unp2 > (uintptr_t)unp) {
UNP_PCB_LOCK(unp);
UNP_PCB_LOCK(unp2);
} else {
UNP_PCB_LOCK(unp2);
UNP_PCB_LOCK(unp);
}
}
static void
unp_pcb_unlock_pair(struct unpcb *unp, struct unpcb *unp2)
{
UNP_PCB_UNLOCK(unp);
if (unp != unp2)
UNP_PCB_UNLOCK(unp2);
}
/*
* Try to lock the connected peer of an already locked socket. In some cases
* this requires that we unlock the current socket. The pairbusy counter is
* used to block concurrent connection attempts while the lock is dropped. The
* caller must be careful to revalidate PCB state.
*/
static struct unpcb *
unp_pcb_lock_peer(struct unpcb *unp)
{
struct unpcb *unp2;
UNP_PCB_LOCK_ASSERT(unp);
unp2 = unp->unp_conn;
if (unp2 == NULL)
return (NULL);
if (__predict_false(unp == unp2))
return (unp);
UNP_PCB_UNLOCK_ASSERT(unp2);
if (__predict_true(UNP_PCB_TRYLOCK(unp2)))
return (unp2);
if ((uintptr_t)unp2 > (uintptr_t)unp) {
UNP_PCB_LOCK(unp2);
return (unp2);
}
unp->unp_pairbusy++;
unp_pcb_hold(unp2);
UNP_PCB_UNLOCK(unp);
UNP_PCB_LOCK(unp2);
UNP_PCB_LOCK(unp);
KASSERT(unp->unp_conn == unp2 || unp->unp_conn == NULL,
("%s: socket %p was reconnected", __func__, unp));
if (--unp->unp_pairbusy == 0 && (unp->unp_flags & UNP_WAITING) != 0) {
unp->unp_flags &= ~UNP_WAITING;
wakeup(unp);
}
if (unp_pcb_rele(unp2)) {
/* unp2 is unlocked. */
return (NULL);
}
if (unp->unp_conn == NULL) {
UNP_PCB_UNLOCK(unp2);
return (NULL);
}
return (unp2);
}
/*
* Try to lock peer of our socket for purposes of sending data to it.
*/
static int
uipc_lock_peer(struct socket *so, struct unpcb **unp2)
{
struct unpcb *unp;
int error;
unp = sotounpcb(so);
UNP_PCB_LOCK(unp);
*unp2 = unp_pcb_lock_peer(unp);
if (__predict_false(so->so_error != 0)) {
error = so->so_error;
so->so_error = 0;
UNP_PCB_UNLOCK(unp);
if (*unp2 != NULL)
UNP_PCB_UNLOCK(*unp2);
return (error);
}
if (__predict_false(*unp2 == NULL)) {
/*
* Different error code for a previously connected socket and
* a never connected one. The SS_ISDISCONNECTED is set in the
* unp_soisdisconnected() and is synchronized by the pcb lock.
*/
error = so->so_state & SS_ISDISCONNECTED ? EPIPE : ENOTCONN;
UNP_PCB_UNLOCK(unp);
return (error);
}
UNP_PCB_UNLOCK(unp);
return (0);
}
static void
uipc_abort(struct socket *so)
{
struct unpcb *unp, *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
UNP_PCB_UNLOCK_ASSERT(unp);
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (unp2 != NULL) {
unp_pcb_hold(unp2);
UNP_PCB_UNLOCK(unp);
unp_drop(unp2);
} else
UNP_PCB_UNLOCK(unp);
}
static int
uipc_attach(struct socket *so, int proto, struct thread *td)
{
u_long sendspace, recvspace;
struct unpcb *unp;
- int error;
+ int error, rcvmtxopts;
bool locked;
KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
switch (so->so_type) {
case SOCK_DGRAM:
STAILQ_INIT(&so->so_rcv.uxdg_mb);
STAILQ_INIT(&so->so_snd.uxdg_mb);
TAILQ_INIT(&so->so_rcv.uxdg_conns);
/*
* Since send buffer is either bypassed or is a part
* of one-to-many receive buffer, we assign both space
* limits to unpdg_recvspace.
*/
sendspace = recvspace = unpdg_recvspace;
+ rcvmtxopts = 0;
break;
case SOCK_STREAM:
sendspace = unpst_sendspace;
recvspace = unpst_recvspace;
goto common;
case SOCK_SEQPACKET:
sendspace = unpsp_sendspace;
recvspace = unpsp_recvspace;
common:
- /*
- * XXXGL: we need to initialize the mutex with MTX_DUPOK.
- * Ideally, protocols that have PR_SOCKBUF should be
- * responsible for mutex initialization officially, and then
- * this uglyness with mtx_destroy(); mtx_init(); would go away.
- */
- mtx_destroy(&so->so_rcv_mtx);
- mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF | MTX_DUPOK);
+ rcvmtxopts = MTX_DUPOK;
knlist_init(&so->so_wrsel.si_note, so, uipc_wrknl_lock,
uipc_wrknl_unlock, uipc_wrknl_assert_lock);
STAILQ_INIT(&so->so_rcv.uxst_mbq);
break;
default:
panic("uipc_attach");
}
+ mtx_init(&so->so_rcv_mtx, "unix so_rcv", NULL, MTX_DEF | rcvmtxopts);
+ mtx_init(&so->so_snd_mtx, "unix so_snd", NULL, MTX_DEF);
error = soreserve(so, sendspace, recvspace);
if (error)
return (error);
unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
if (unp == NULL)
return (ENOBUFS);
LIST_INIT(&unp->unp_refs);
UNP_PCB_LOCK_INIT(unp);
unp->unp_socket = so;
so->so_pcb = unp;
refcount_init(&unp->unp_refcount, 1);
unp->unp_mode = ACCESSPERMS;
if ((locked = UNP_LINK_WOWNED()) == false)
UNP_LINK_WLOCK();
unp->unp_gencnt = ++unp_gencnt;
unp->unp_ino = ++unp_ino;
unp_count++;
switch (so->so_type) {
case SOCK_STREAM:
LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
break;
case SOCK_DGRAM:
LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
break;
case SOCK_SEQPACKET:
LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
break;
default:
panic("uipc_attach");
}
if (locked == false)
UNP_LINK_WUNLOCK();
return (0);
}
static int
uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct sockaddr_un *soun = (struct sockaddr_un *)nam;
struct vattr vattr;
int error, namelen;
struct nameidata nd;
struct unpcb *unp;
struct vnode *vp;
struct mount *mp;
cap_rights_t rights;
char *buf;
mode_t mode;
if (nam->sa_family != AF_UNIX)
return (EAFNOSUPPORT);
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
if (soun->sun_len > sizeof(struct sockaddr_un))
return (EINVAL);
namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
if (namelen <= 0)
return (EINVAL);
/*
* We don't allow simultaneous bind() calls on a single UNIX domain
* socket, so flag in-progress operations, and return an error if an
* operation is already in progress.
*
* Historically, we have not allowed a socket to be rebound, so this
* also returns an error. Not allowing re-binding simplifies the
* implementation and avoids a great many possible failure modes.
*/
UNP_PCB_LOCK(unp);
if (unp->unp_vnode != NULL) {
UNP_PCB_UNLOCK(unp);
return (EINVAL);
}
if (unp->unp_flags & UNP_BINDING) {
UNP_PCB_UNLOCK(unp);
return (EALREADY);
}
unp->unp_flags |= UNP_BINDING;
mode = unp->unp_mode & ~td->td_proc->p_pd->pd_cmask;
UNP_PCB_UNLOCK(unp);
buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
bcopy(soun->sun_path, buf, namelen);
buf[namelen] = 0;
restart:
NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | NOCACHE,
UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_BINDAT));
/* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
error = namei(&nd);
if (error)
goto error;
vp = nd.ni_vp;
if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
NDFREE_PNBUF(&nd);
if (nd.ni_dvp == vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
if (vp != NULL) {
vrele(vp);
error = EADDRINUSE;
goto error;
}
error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH);
if (error)
goto error;
goto restart;
}
VATTR_NULL(&vattr);
vattr.va_type = VSOCK;
vattr.va_mode = mode;
#ifdef MAC
error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
&vattr);
#endif
if (error == 0) {
/*
* The prior lookup may have left LK_SHARED in cn_lkflags,
* and VOP_CREATE technically only requires the new vnode to
* be locked shared. Most filesystems will return the new vnode
* locked exclusive regardless, but we should explicitly
* specify that here since we require it and assert to that
* effect below.
*/
nd.ni_cnd.cn_lkflags = (nd.ni_cnd.cn_lkflags & ~LK_SHARED) |
LK_EXCLUSIVE;
error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
}
NDFREE_PNBUF(&nd);
if (error) {
VOP_VPUT_PAIR(nd.ni_dvp, NULL, true);
vn_finished_write(mp);
if (error == ERELOOKUP)
goto restart;
goto error;
}
vp = nd.ni_vp;
ASSERT_VOP_ELOCKED(vp, "uipc_bind");
soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
UNP_PCB_LOCK(unp);
VOP_UNP_BIND(vp, unp);
unp->unp_vnode = vp;
unp->unp_addr = soun;
unp->unp_flags &= ~UNP_BINDING;
UNP_PCB_UNLOCK(unp);
vref(vp);
VOP_VPUT_PAIR(nd.ni_dvp, &vp, true);
vn_finished_write(mp);
free(buf, M_TEMP);
return (0);
error:
UNP_PCB_LOCK(unp);
unp->unp_flags &= ~UNP_BINDING;
UNP_PCB_UNLOCK(unp);
free(buf, M_TEMP);
return (error);
}
static int
uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (uipc_bindat(AT_FDCWD, so, nam, td));
}
static int
uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
KASSERT(td == curthread, ("uipc_connect: td != curthread"));
error = unp_connect(so, nam, td);
return (error);
}
static int
uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
struct thread *td)
{
int error;
KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
error = unp_connectat(fd, so, nam, td, false);
return (error);
}
static void
uipc_close(struct socket *so)
{
struct unpcb *unp, *unp2;
struct vnode *vp = NULL;
struct mtx *vplock;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
vplock = NULL;
if ((vp = unp->unp_vnode) != NULL) {
vplock = mtx_pool_find(unp_vp_mtxpool, vp);
mtx_lock(vplock);
}
UNP_PCB_LOCK(unp);
if (vp && unp->unp_vnode == NULL) {
mtx_unlock(vplock);
vp = NULL;
}
if (vp != NULL) {
VOP_UNP_DETACH(vp);
unp->unp_vnode = NULL;
}
if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
unp_disconnect(unp, unp2);
else
UNP_PCB_UNLOCK(unp);
if (vp) {
mtx_unlock(vplock);
vrele(vp);
}
}
static int
uipc_chmod(struct socket *so, mode_t mode, struct ucred *cred __unused,
struct thread *td __unused)
{
struct unpcb *unp;
int error;
if ((mode & ~ACCESSPERMS) != 0)
return (EINVAL);
error = 0;
unp = sotounpcb(so);
UNP_PCB_LOCK(unp);
if (unp->unp_vnode != NULL || (unp->unp_flags & UNP_BINDING) != 0)
error = EINVAL;
else
unp->unp_mode = mode;
UNP_PCB_UNLOCK(unp);
return (error);
}
static int
uipc_connect2(struct socket *so1, struct socket *so2)
{
struct unpcb *unp, *unp2;
if (so1->so_type != so2->so_type)
return (EPROTOTYPE);
unp = so1->so_pcb;
KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
unp2 = so2->so_pcb;
KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
unp_pcb_lock_pair(unp, unp2);
unp_connect2(so1, so2, false);
unp_pcb_unlock_pair(unp, unp2);
return (0);
}
static void
maybe_schedule_gc(void)
{
if (atomic_load_int(&unp_rights) != 0)
taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
}
static void
uipc_detach(struct socket *so)
{
struct unpcb *unp, *unp2;
struct mtx *vplock;
struct vnode *vp;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
vp = NULL;
vplock = NULL;
if (!SOLISTENING(so))
unp_dispose(so);
UNP_LINK_WLOCK();
LIST_REMOVE(unp, unp_link);
if (unp->unp_gcflag & UNPGC_DEAD)
LIST_REMOVE(unp, unp_dead);
unp->unp_gencnt = ++unp_gencnt;
--unp_count;
UNP_LINK_WUNLOCK();
UNP_PCB_UNLOCK_ASSERT(unp);
restart:
if ((vp = unp->unp_vnode) != NULL) {
vplock = mtx_pool_find(unp_vp_mtxpool, vp);
mtx_lock(vplock);
}
UNP_PCB_LOCK(unp);
if (unp->unp_vnode != vp && unp->unp_vnode != NULL) {
if (vplock)
mtx_unlock(vplock);
UNP_PCB_UNLOCK(unp);
goto restart;
}
if ((vp = unp->unp_vnode) != NULL) {
VOP_UNP_DETACH(vp);
unp->unp_vnode = NULL;
}
if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
unp_disconnect(unp, unp2);
else
UNP_PCB_UNLOCK(unp);
UNP_REF_LIST_LOCK();
while (!LIST_EMPTY(&unp->unp_refs)) {
struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
unp_pcb_hold(ref);
UNP_REF_LIST_UNLOCK();
MPASS(ref != unp);
UNP_PCB_UNLOCK_ASSERT(ref);
unp_drop(ref);
UNP_REF_LIST_LOCK();
}
UNP_REF_LIST_UNLOCK();
UNP_PCB_LOCK(unp);
unp->unp_socket->so_pcb = NULL;
unp->unp_socket = NULL;
free(unp->unp_addr, M_SONAME);
unp->unp_addr = NULL;
if (!unp_pcb_rele(unp))
UNP_PCB_UNLOCK(unp);
if (vp) {
mtx_unlock(vplock);
vrele(vp);
}
maybe_schedule_gc();
switch (so->so_type) {
case SOCK_STREAM:
case SOCK_SEQPACKET:
MPASS(SOLISTENING(so) || (STAILQ_EMPTY(&so->so_rcv.uxst_mbq) &&
so->so_rcv.uxst_peer == NULL));
break;
case SOCK_DGRAM:
/*
* Everything should have been unlinked/freed by unp_dispose()
* and/or unp_disconnect().
*/
MPASS(so->so_rcv.uxdg_peeked == NULL);
MPASS(STAILQ_EMPTY(&so->so_rcv.uxdg_mb));
MPASS(TAILQ_EMPTY(&so->so_rcv.uxdg_conns));
MPASS(STAILQ_EMPTY(&so->so_snd.uxdg_mb));
}
+
+ mtx_destroy(&so->so_snd_mtx);
+ mtx_destroy(&so->so_rcv_mtx);
}
static int
uipc_disconnect(struct socket *so)
{
struct unpcb *unp, *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
UNP_PCB_LOCK(unp);
if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
unp_disconnect(unp, unp2);
else
UNP_PCB_UNLOCK(unp);
return (0);
}
static void
uipc_fdclose(struct socket *so __unused)
{
/*
* Ensure that userspace can't create orphaned file descriptors without
* triggering garbage collection. Triggering GC from uipc_detach() is
* not sufficient, since that's only closed once a socket reference
* count drops to zero.
*/
maybe_schedule_gc();
}
static int
uipc_listen(struct socket *so, int backlog, struct thread *td)
{
struct unpcb *unp;
int error;
MPASS(so->so_type != SOCK_DGRAM);
/*
* Synchronize with concurrent connection attempts.
*/
error = 0;
unp = sotounpcb(so);
UNP_PCB_LOCK(unp);
if (unp->unp_conn != NULL || (unp->unp_flags & UNP_CONNECTING) != 0)
error = EINVAL;
else if (unp->unp_vnode == NULL)
error = EDESTADDRREQ;
if (error != 0) {
UNP_PCB_UNLOCK(unp);
return (error);
}
SOCK_LOCK(so);
error = solisten_proto_check(so);
if (error == 0) {
cru2xt(td, &unp->unp_peercred);
if (!SOLISTENING(so)) {
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
}
solisten_proto(so, backlog);
}
SOCK_UNLOCK(so);
UNP_PCB_UNLOCK(unp);
return (error);
}
static int
uipc_peeraddr(struct socket *so, struct sockaddr *ret)
{
struct unpcb *unp, *unp2;
const struct sockaddr *sa;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
UNP_PCB_LOCK(unp);
unp2 = unp_pcb_lock_peer(unp);
if (unp2 != NULL) {
if (unp2->unp_addr != NULL)
sa = (struct sockaddr *)unp2->unp_addr;
else
sa = &sun_noname;
bcopy(sa, ret, sa->sa_len);
unp_pcb_unlock_pair(unp, unp2);
} else {
UNP_PCB_UNLOCK(unp);
sa = &sun_noname;
bcopy(sa, ret, sa->sa_len);
}
return (0);
}
/*
* pr_sosend() called with mbuf instead of uio is a kernel thread. NFS,
* netgraph(4) and other subsystems can call into socket code. The
* function will condition the mbuf so that it can be safely put onto socket
* buffer and calculate its char count and mbuf count.
*
* Note: we don't support receiving control data from a kernel thread. Our
* pr_sosend methods have MPASS() to check that. This may change.
*/
static void
uipc_reset_kernel_mbuf(struct mbuf *m, struct mchain *mc)
{
M_ASSERTPKTHDR(m);
m_clrprotoflags(m);
m_tag_delete_chain(m, NULL);
m->m_pkthdr.rcvif = NULL;
m->m_pkthdr.flowid = 0;
m->m_pkthdr.csum_flags = 0;
m->m_pkthdr.fibnum = 0;
m->m_pkthdr.rsstype = 0;
mc_init_m(mc, m);
MPASS(m->m_pkthdr.len == mc->mc_len);
}
#ifdef SOCKBUF_DEBUG
static inline void
uipc_stream_sbcheck(struct sockbuf *sb)
{
struct mbuf *d;
u_int dacc, dccc, dctl, dmbcnt;
bool notready = false;
dacc = dccc = dctl = dmbcnt = 0;
STAILQ_FOREACH(d, &sb->uxst_mbq, m_stailq) {
if (d == sb->uxst_fnrdy) {
MPASS(d->m_flags & M_NOTREADY);
notready = true;
}
if (d->m_type == MT_CONTROL)
dctl += d->m_len;
else if (d->m_type == MT_DATA) {
dccc += d->m_len;
if (!notready)
dacc += d->m_len;
} else
MPASS(0);
dmbcnt += MSIZE;
if (d->m_flags & M_EXT)
dmbcnt += d->m_ext.ext_size;
if (d->m_stailq.stqe_next == NULL)
MPASS(sb->uxst_mbq.stqh_last == &d->m_stailq.stqe_next);
}
MPASS(sb->uxst_fnrdy == NULL || notready);
MPASS(dacc == sb->sb_acc);
MPASS(dccc == sb->sb_ccc);
MPASS(dctl == sb->sb_ctl);
MPASS(dmbcnt == sb->sb_mbcnt);
(void)STAILQ_EMPTY(&sb->uxst_mbq);
}
#define UIPC_STREAM_SBCHECK(sb) uipc_stream_sbcheck(sb)
#else
#define UIPC_STREAM_SBCHECK(sb) do {} while (0)
#endif
/*
* uipc_stream_sbspace() returns how much a writer can send, limited by char
* count or mbuf memory use, whatever ends first.
*
* An obvious and legitimate reason for a socket having more data than allowed,
* is lowering the limit with setsockopt(SO_RCVBUF) on already full buffer.
* Also, sb_mbcnt may overcommit sb_mbmax in case if previous write observed
* 'space < mbspace', but mchain allocated to hold 'space' bytes of data ended
* up with 'mc_mlen > mbspace'. A typical scenario would be a full buffer with
* writer trying to push in a large write, and a slow reader, that reads just
* a few bytes at a time. In that case writer will keep creating new mbufs
* with mc_split(). These mbufs will carry little chars, but will all point at
* the same cluster, thus each adding cluster size to sb_mbcnt. This means we
* will count same cluster many times potentially underutilizing socket buffer.
* We aren't optimizing towards ineffective readers. Classic socket buffer had
* the same "feature".
*/
static inline u_int
uipc_stream_sbspace(struct sockbuf *sb)
{
u_int space, mbspace;
if (__predict_true(sb->sb_hiwat >= sb->sb_ccc + sb->sb_ctl))
space = sb->sb_hiwat - sb->sb_ccc - sb->sb_ctl;
else
return (0);
if (__predict_true(sb->sb_mbmax >= sb->sb_mbcnt))
mbspace = sb->sb_mbmax - sb->sb_mbcnt;
else
return (0);
return (min(space, mbspace));
}
/*
* UNIX version of generic sbwait() for writes. We wait on peer's receive
* buffer, using our timeout.
*/
static int
uipc_stream_sbwait(struct socket *so, sbintime_t timeo)
{
struct sockbuf *sb = &so->so_rcv;
SOCK_RECVBUF_LOCK_ASSERT(so);
sb->sb_flags |= SB_WAIT;
return (msleep_sbt(&sb->sb_acc, SOCK_RECVBUF_MTX(so), PSOCK | PCATCH,
"sbwait", timeo, 0, 0));
}
static int
uipc_sosend_stream_or_seqpacket(struct socket *so, struct sockaddr *addr,
struct uio *uio0, struct mbuf *m, struct mbuf *c, int flags,
struct thread *td)
{
struct unpcb *unp2;
struct socket *so2;
struct sockbuf *sb;
struct uio *uio;
struct mchain mc, cmc;
size_t resid, sent;
bool nonblock, eor, aio;
int error;
MPASS((uio0 != NULL && m == NULL) || (m != NULL && uio0 == NULL));
MPASS(m == NULL || c == NULL);
if (__predict_false(flags & MSG_OOB))
return (EOPNOTSUPP);
nonblock = (so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT | MSG_NBIO));
eor = flags & MSG_EOR;
mc = MCHAIN_INITIALIZER(&mc);
cmc = MCHAIN_INITIALIZER(&cmc);
sent = 0;
aio = false;
if (m == NULL) {
if (c != NULL && (error = unp_internalize(c, &cmc, td)))
goto out;
/*
* This function may read more data from the uio than it would
* then place on socket. That would leave uio inconsistent
* upon return. Normally uio is allocated on the stack of the
* syscall thread and we don't care about leaving it consistent.
* However, aio(9) will allocate a uio as part of job and will
* use it to track progress. We detect aio(9) checking the
* SB_AIO_RUNNING flag. It is safe to check it without lock
* cause it is set and cleared in the same taskqueue thread.
*
* This check can also produce a false positive: there is
* aio(9) job and also there is a syscall we are serving now.
* No sane software does that, it would leave to a mess in
* the socket buffer, as aio(9) doesn't grab the I/O sx(9).
* But syzkaller can create this mess. For such false positive
* our goal is just don't panic or leak memory.
*/
if (__predict_false(so->so_snd.sb_flags & SB_AIO_RUNNING)) {
uio = cloneuio(uio0);
aio = true;
} else {
uio = uio0;
resid = uio->uio_resid;
}
/*
* Optimization for a case when our send fits into the receive
* buffer - do the copyin before taking any locks, sized to our
* send buffer. Later copyins will also take into account
* space in the peer's receive buffer.
*/
error = mc_uiotomc(&mc, uio, so->so_snd.sb_hiwat, 0, M_WAITOK,
eor ? M_EOR : 0);
if (__predict_false(error))
goto out2;
} else
uipc_reset_kernel_mbuf(m, &mc);
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
if (error)
goto out2;
if (__predict_false((error = uipc_lock_peer(so, &unp2)) != 0))
goto out3;
if (unp2->unp_flags & UNP_WANTCRED_MASK) {
/*
* Credentials are passed only once on SOCK_STREAM and
* SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or
* forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS).
*/
unp_addsockcred(td, &cmc, unp2->unp_flags);
unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT;
}
/*
* Cycle through the data to send and available space in the peer's
* receive buffer. Put a reference on the peer socket, so that it
* doesn't get freed while we sbwait(). If peer goes away, we will
* observe the SBS_CANTRCVMORE and our sorele() will finalize peer's
* socket destruction.
*/
so2 = unp2->unp_socket;
soref(so2);
UNP_PCB_UNLOCK(unp2);
sb = &so2->so_rcv;
while (mc.mc_len + cmc.mc_len > 0) {
struct mchain mcnext = MCHAIN_INITIALIZER(&mcnext);
u_int space;
SOCK_RECVBUF_LOCK(so2);
restart:
UIPC_STREAM_SBCHECK(sb);
if (__predict_false(cmc.mc_len > sb->sb_hiwat)) {
SOCK_RECVBUF_UNLOCK(so2);
error = EMSGSIZE;
goto out4;
}
if (__predict_false(sb->sb_state & SBS_CANTRCVMORE)) {
SOCK_RECVBUF_UNLOCK(so2);
error = EPIPE;
goto out4;
}
/*
* Wait on the peer socket receive buffer until we have enough
* space to put at least control. The data is a stream and can
* be put partially, but control is really a datagram.
*/
space = uipc_stream_sbspace(sb);
if (space < sb->sb_lowat || space < cmc.mc_len) {
if (nonblock) {
if (aio)
sb->uxst_flags |= UXST_PEER_AIO;
SOCK_RECVBUF_UNLOCK(so2);
if (aio) {
SOCK_SENDBUF_LOCK(so);
so->so_snd.sb_ccc =
so->so_snd.sb_hiwat - space;
SOCK_SENDBUF_UNLOCK(so);
}
error = EWOULDBLOCK;
goto out4;
}
if ((error = uipc_stream_sbwait(so2,
so->so_snd.sb_timeo)) != 0) {
SOCK_RECVBUF_UNLOCK(so2);
goto out4;
} else
goto restart;
}
MPASS(space >= cmc.mc_len);
space -= cmc.mc_len;
if (space == 0) {
/* There is space only to send control. */
MPASS(!STAILQ_EMPTY(&cmc.mc_q));
mcnext = mc;
mc = MCHAIN_INITIALIZER(&mc);
} else if (space < mc.mc_len) {
/* Not enough space. */
if (__predict_false(mc_split(&mc, &mcnext, space,
M_NOWAIT) == ENOMEM)) {
/*
* If allocation failed use M_WAITOK and merge
* the chain back. Next time mc_split() will
* easily split at the same place. Only if we
* race with setsockopt(SO_RCVBUF) shrinking
* sb_hiwat can this happen more than once.
*/
SOCK_RECVBUF_UNLOCK(so2);
(void)mc_split(&mc, &mcnext, space, M_WAITOK);
mc_concat(&mc, &mcnext);
SOCK_RECVBUF_LOCK(so2);
goto restart;
}
MPASS(mc.mc_len == space);
}
if (!STAILQ_EMPTY(&cmc.mc_q)) {
STAILQ_CONCAT(&sb->uxst_mbq, &cmc.mc_q);
sb->sb_ctl += cmc.mc_len;
sb->sb_mbcnt += cmc.mc_mlen;
cmc.mc_len = 0;
}
sent += mc.mc_len;
if (sb->uxst_fnrdy == NULL)
sb->sb_acc += mc.mc_len;
sb->sb_ccc += mc.mc_len;
sb->sb_mbcnt += mc.mc_mlen;
STAILQ_CONCAT(&sb->uxst_mbq, &mc.mc_q);
UIPC_STREAM_SBCHECK(sb);
space = uipc_stream_sbspace(sb);
sorwakeup_locked(so2);
if (!STAILQ_EMPTY(&mcnext.mc_q)) {
/*
* Such assignment is unsafe in general, but it is
* safe with !STAILQ_EMPTY(&mcnext.mc_q). In C++ we
* could reload = for STAILQs :)
*/
mc = mcnext;
} else if (uio != NULL && uio->uio_resid > 0) {
/*
* Copyin sum of peer's receive buffer space and our
* sb_hiwat, which is our virtual send buffer size.
* See comment above unpst_sendspace declaration.
* We are reading sb_hiwat locklessly, cause a) we
* don't care about an application that does send(2)
* and setsockopt(2) racing internally, and for an
* application that does this in sequence we will see
* the correct value cause sbsetopt() uses buffer lock
* and we also have already acquired it at least once.
*/
error = mc_uiotomc(&mc, uio, space +
atomic_load_int(&so->so_snd.sb_hiwat), 0, M_WAITOK,
eor ? M_EOR : 0);
if (__predict_false(error))
goto out4;
} else
mc = MCHAIN_INITIALIZER(&mc);
}
MPASS(STAILQ_EMPTY(&mc.mc_q));
td->td_ru.ru_msgsnd++;
out4:
sorele(so2);
out3:
SOCK_IO_SEND_UNLOCK(so);
out2:
if (aio) {
freeuio(uio);
uioadvance(uio0, sent);
} else if (uio != NULL)
uio->uio_resid = resid - sent;
if (!mc_empty(&cmc))
unp_scan(mc_first(&cmc), unp_freerights);
out:
mc_freem(&mc);
mc_freem(&cmc);
return (error);
}
/*
* Wakeup a writer, used by recv(2) and shutdown(2).
*
* @param so Points to a connected stream socket with receive buffer locked
*
* In a blocking mode peer is sleeping on our receive buffer, and we need just
* wakeup(9) on it. But to wake up various event engines, we need to reach
* over to peer's selinfo. This can be safely done as the socket buffer
* receive lock is protecting us from the peer going away.
*/
static void
uipc_wakeup_writer(struct socket *so)
{
struct sockbuf *sb = &so->so_rcv;
struct selinfo *sel;
SOCK_RECVBUF_LOCK_ASSERT(so);
MPASS(sb->uxst_peer != NULL);
sel = &sb->uxst_peer->so_wrsel;
if (sb->uxst_flags & UXST_PEER_SEL) {
selwakeuppri(sel, PSOCK);
/*
* XXXGL: sowakeup() does SEL_WAITING() without locks.
*/
if (!SEL_WAITING(sel))
sb->uxst_flags &= ~UXST_PEER_SEL;
}
if (sb->sb_flags & SB_WAIT) {
sb->sb_flags &= ~SB_WAIT;
wakeup(&sb->sb_acc);
}
KNOTE_LOCKED(&sel->si_note, 0);
SOCK_RECVBUF_UNLOCK(so);
}
static void
uipc_cantrcvmore(struct socket *so)
{
SOCK_RECVBUF_LOCK(so);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
selwakeuppri(&so->so_rdsel, PSOCK);
KNOTE_LOCKED(&so->so_rdsel.si_note, 0);
if (so->so_rcv.uxst_peer != NULL)
uipc_wakeup_writer(so);
else
SOCK_RECVBUF_UNLOCK(so);
}
static int
uipc_soreceive_stream_or_seqpacket(struct socket *so, struct sockaddr **psa,
struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
struct sockbuf *sb = &so->so_rcv;
struct mbuf *control, *m, *first, *part, *next;
u_int ctl, space, datalen, mbcnt, partlen;
int error, flags;
bool nonblock, waitall, peek;
MPASS(mp0 == NULL);
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
flags = flagsp != NULL ? *flagsp : 0;
nonblock = (so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT | MSG_NBIO));
peek = flags & MSG_PEEK;
waitall = (flags & MSG_WAITALL) && !peek;
/*
* This check may fail only on a socket that never went through
* connect(2). We can check this locklessly, cause: a) for a new born
* socket we don't care about applications that may race internally
* between connect(2) and recv(2), and b) for a dying socket if we
* miss update by unp_sosidisconnected(), we would still get the check
* correct. For dying socket we would observe SBS_CANTRCVMORE later.
*/
if (__predict_false((atomic_load_short(&so->so_state) &
(SS_ISCONNECTED|SS_ISDISCONNECTED)) == 0))
return (ENOTCONN);
error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
if (__predict_false(error))
return (error);
restart:
SOCK_RECVBUF_LOCK(so);
UIPC_STREAM_SBCHECK(sb);
while (sb->sb_acc < sb->sb_lowat &&
(sb->sb_ctl == 0 || controlp == NULL)) {
if (so->so_error) {
error = so->so_error;
if (!peek)
so->so_error = 0;
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
if (sb->sb_state & SBS_CANTRCVMORE) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (0);
}
if (nonblock) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (EWOULDBLOCK);
}
error = sbwait(so, SO_RCV);
if (error) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
}
MPASS(STAILQ_FIRST(&sb->uxst_mbq));
MPASS(sb->sb_acc > 0 || sb->sb_ctl > 0);
mbcnt = 0;
ctl = 0;
first = STAILQ_FIRST(&sb->uxst_mbq);
if (first->m_type == MT_CONTROL) {
control = first;
STAILQ_FOREACH_FROM(first, &sb->uxst_mbq, m_stailq) {
if (first->m_type != MT_CONTROL)
break;
ctl += first->m_len;
mbcnt += MSIZE;
if (first->m_flags & M_EXT)
mbcnt += first->m_ext.ext_size;
}
} else
control = NULL;
/*
* Find split point for the next copyout. On exit from the loop,
* 'next' points to the new head of the buffer STAILQ and 'datalen'
* contains the amount of data we will copy out at the end. The
* copyout is protected by the I/O lock only, as writers can only
* append to the buffer. We need to record the socket buffer state
* and do all length adjustments before dropping the socket buffer lock.
*/
for (space = uio->uio_resid, m = next = first, part = NULL, datalen = 0;
space > 0 && m != sb->uxst_fnrdy && m->m_type == MT_DATA;
m = STAILQ_NEXT(m, m_stailq)) {
if (space >= m->m_len) {
space -= m->m_len;
datalen += m->m_len;
mbcnt += MSIZE;
if (m->m_flags & M_EXT)
mbcnt += m->m_ext.ext_size;
if (m->m_flags & M_EOR) {
flags |= MSG_EOR;
next = STAILQ_NEXT(m, m_stailq);
break;
}
} else {
datalen += space;
partlen = space;
if (!peek) {
m->m_len -= partlen;
m->m_data += partlen;
}
next = part = m;
break;
}
next = STAILQ_NEXT(m, m_stailq);
}
if (!peek) {
if (next == NULL)
STAILQ_INIT(&sb->uxst_mbq);
else
STAILQ_FIRST(&sb->uxst_mbq) = next;
MPASS(sb->sb_acc >= datalen);
sb->sb_acc -= datalen;
sb->sb_ccc -= datalen;
MPASS(sb->sb_ctl >= ctl);
sb->sb_ctl -= ctl;
MPASS(sb->sb_mbcnt >= mbcnt);
sb->sb_mbcnt -= mbcnt;
UIPC_STREAM_SBCHECK(sb);
if (__predict_true(sb->uxst_peer != NULL)) {
struct unpcb *unp2;
bool aio;
if ((aio = sb->uxst_flags & UXST_PEER_AIO))
sb->uxst_flags &= ~UXST_PEER_AIO;
uipc_wakeup_writer(so);
/*
* XXXGL: need to go through uipc_lock_peer() after
* the receive buffer lock dropped, it was protecting
* us from unp_soisdisconnected(). The aio workarounds
* should be refactored to the aio(4) side.
*/
if (aio && uipc_lock_peer(so, &unp2) == 0) {
struct socket *so2 = unp2->unp_socket;
SOCK_SENDBUF_LOCK(so2);
so2->so_snd.sb_ccc -= datalen;
sowakeup_aio(so2, SO_SND);
SOCK_SENDBUF_UNLOCK(so2);
UNP_PCB_UNLOCK(unp2);
}
} else
SOCK_RECVBUF_UNLOCK(so);
} else
SOCK_RECVBUF_UNLOCK(so);
while (control != NULL && control->m_type == MT_CONTROL) {
if (!peek) {
/*
* unp_externalize() failure must abort entire read(2).
* Such failure should also free the problematic
* control, but link back the remaining data to the head
* of the buffer, so that socket is not left in a state
* where it can't progress forward with reading.
* Probability of such a failure is really low, so it
* is fine that we need to perform pretty complex
* operation here to reconstruct the buffer.
*/
error = unp_externalize(control, controlp, flags);
control = m_free(control);
if (__predict_false(error && control != NULL)) {
struct mchain cmc;
mc_init_m(&cmc, control);
SOCK_RECVBUF_LOCK(so);
if (__predict_false(
(sb->sb_state & SBS_CANTRCVMORE) ||
cmc.mc_len + sb->sb_ccc + sb->sb_ctl >
sb->sb_hiwat)) {
/*
* While the lock was dropped and we
* were failing in unp_externalize(),
* the peer could has a) disconnected,
* b) filled the buffer so that we
* can't prepend data back.
* These are two edge conditions that
* we just can't handle, so lose the
* data and return the error.
*/
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
unp_scan(mc_first(&cmc),
unp_freerights);
mc_freem(&cmc);
return (error);
}
UIPC_STREAM_SBCHECK(sb);
/* XXXGL: STAILQ_PREPEND */
STAILQ_CONCAT(&cmc.mc_q, &sb->uxst_mbq);
STAILQ_SWAP(&cmc.mc_q, &sb->uxst_mbq, mbuf);
sb->sb_ctl = sb->sb_acc = sb->sb_ccc =
sb->sb_mbcnt = 0;
STAILQ_FOREACH(m, &sb->uxst_mbq, m_stailq) {
if (m->m_type == MT_DATA) {
sb->sb_acc += m->m_len;
sb->sb_ccc += m->m_len;
} else {
sb->sb_ctl += m->m_len;
}
sb->sb_mbcnt += MSIZE;
if (m->m_flags & M_EXT)
sb->sb_mbcnt +=
m->m_ext.ext_size;
}
UIPC_STREAM_SBCHECK(sb);
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
} else {
/*
* XXXGL
*
* In MSG_PEEK case control is not externalized. This
* means we are leaking some kernel pointers to the
* userland. They are useless to a law-abiding
* application, but may be useful to a malware. This
* is what the historical implementation in the
* soreceive_generic() did. To be improved?
*/
if (controlp != NULL) {
*controlp = m_copym(control, 0, control->m_len,
M_WAITOK);
controlp = &(*controlp)->m_next;
}
control = STAILQ_NEXT(control, m_stailq);
}
}
for (m = first; datalen > 0; m = next) {
void *data;
u_int len;
next = STAILQ_NEXT(m, m_stailq);
if (m == part) {
data = peek ?
mtod(m, char *) : mtod(m, char *) - partlen;
len = partlen;
} else {
data = mtod(m, char *);
len = m->m_len;
}
error = uiomove(data, len, uio);
if (__predict_false(error)) {
if (!peek)
for (; m != part && datalen > 0; m = next) {
next = STAILQ_NEXT(m, m_stailq);
MPASS(datalen >= m->m_len);
datalen -= m->m_len;
m_free(m);
}
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
datalen -= len;
if (!peek && m != part)
m_free(m);
}
if (waitall && !(flags & MSG_EOR) && uio->uio_resid > 0)
goto restart;
SOCK_IO_RECV_UNLOCK(so);
if (flagsp != NULL)
*flagsp |= flags;
uio->uio_td->td_ru.ru_msgrcv++;
return (0);
}
static int
uipc_sopoll_stream_or_seqpacket(struct socket *so, int events,
struct thread *td)
{
struct unpcb *unp = sotounpcb(so);
int revents;
UNP_PCB_LOCK(unp);
if (SOLISTENING(so)) {
/* The above check is safe, since conversion to listening uses
* both protocol and socket lock.
*/
SOCK_LOCK(so);
if (!(events & (POLLIN | POLLRDNORM)))
revents = 0;
else if (!TAILQ_EMPTY(&so->sol_comp))
revents = events & (POLLIN | POLLRDNORM);
else if (so->so_error)
revents = (events & (POLLIN | POLLRDNORM)) | POLLHUP;
else {
selrecord(td, &so->so_rdsel);
revents = 0;
}
SOCK_UNLOCK(so);
} else {
if (so->so_state & SS_ISDISCONNECTED)
revents = POLLHUP;
else
revents = 0;
if (events & (POLLIN | POLLRDNORM | POLLRDHUP)) {
SOCK_RECVBUF_LOCK(so);
if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat ||
so->so_error || so->so_rerror)
revents |= events & (POLLIN | POLLRDNORM);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
revents |= events &
(POLLIN | POLLRDNORM | POLLRDHUP);
if (!(revents & (POLLIN | POLLRDNORM | POLLRDHUP))) {
selrecord(td, &so->so_rdsel);
so->so_rcv.sb_flags |= SB_SEL;
}
SOCK_RECVBUF_UNLOCK(so);
}
if (events & (POLLOUT | POLLWRNORM)) {
struct socket *so2 = so->so_rcv.uxst_peer;
if (so2 != NULL) {
struct sockbuf *sb = &so2->so_rcv;
SOCK_RECVBUF_LOCK(so2);
if (uipc_stream_sbspace(sb) >= sb->sb_lowat)
revents |= events &
(POLLOUT | POLLWRNORM);
if (sb->sb_state & SBS_CANTRCVMORE)
revents |= POLLHUP;
if (!(revents & (POLLOUT | POLLWRNORM))) {
so2->so_rcv.uxst_flags |= UXST_PEER_SEL;
selrecord(td, &so->so_wrsel);
}
SOCK_RECVBUF_UNLOCK(so2);
} else
selrecord(td, &so->so_wrsel);
}
}
UNP_PCB_UNLOCK(unp);
return (revents);
}
static void
uipc_wrknl_lock(void *arg)
{
struct socket *so = arg;
struct unpcb *unp = sotounpcb(so);
retry:
if (SOLISTENING(so)) {
SOLISTEN_LOCK(so);
} else {
UNP_PCB_LOCK(unp);
if (__predict_false(SOLISTENING(so))) {
UNP_PCB_UNLOCK(unp);
goto retry;
}
if (so->so_rcv.uxst_peer != NULL)
SOCK_RECVBUF_LOCK(so->so_rcv.uxst_peer);
}
}
static void
uipc_wrknl_unlock(void *arg)
{
struct socket *so = arg;
struct unpcb *unp = sotounpcb(so);
if (SOLISTENING(so))
SOLISTEN_UNLOCK(so);
else {
if (so->so_rcv.uxst_peer != NULL)
SOCK_RECVBUF_UNLOCK(so->so_rcv.uxst_peer);
UNP_PCB_UNLOCK(unp);
}
}
static void
uipc_wrknl_assert_lock(void *arg, int what)
{
struct socket *so = arg;
if (SOLISTENING(so)) {
if (what == LA_LOCKED)
SOLISTEN_LOCK_ASSERT(so);
else
SOLISTEN_UNLOCK_ASSERT(so);
} else {
/*
* The pr_soreceive method will put a note without owning the
* unp lock, so we can't assert it here. But we can safely
* dereference uxst_peer pointer, since receive buffer lock
* is assumed to be held here.
*/
if (what == LA_LOCKED && so->so_rcv.uxst_peer != NULL)
SOCK_RECVBUF_LOCK_ASSERT(so->so_rcv.uxst_peer);
}
}
static void
uipc_filt_sowdetach(struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
uipc_wrknl_lock(so);
knlist_remove(&so->so_wrsel.si_note, kn, 1);
uipc_wrknl_unlock(so);
}
static int
uipc_filt_sowrite(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data, *so2;
struct unpcb *unp = sotounpcb(so), *unp2 = unp->unp_conn;
if (SOLISTENING(so))
return (0);
if (unp2 == NULL) {
if (so->so_state & SS_ISDISCONNECTED) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
} else
return (0);
}
so2 = unp2->unp_socket;
SOCK_RECVBUF_LOCK_ASSERT(so2);
kn->kn_data = uipc_stream_sbspace(&so2->so_rcv);
if (so2->so_rcv.sb_state & SBS_CANTRCVMORE) {
kn->kn_flags |= EV_EOF;
return (1);
} else if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
else
return (kn->kn_data >= so2->so_rcv.sb_lowat);
}
static int
uipc_filt_soempty(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data, *so2;
struct unpcb *unp = sotounpcb(so), *unp2 = unp->unp_conn;
if (SOLISTENING(so) || unp2 == NULL)
return (1);
so2 = unp2->unp_socket;
SOCK_RECVBUF_LOCK_ASSERT(so2);
kn->kn_data = uipc_stream_sbspace(&so2->so_rcv);
return (kn->kn_data == 0 ? 1 : 0);
}
static const struct filterops uipc_write_filtops = {
.f_isfd = 1,
.f_detach = uipc_filt_sowdetach,
.f_event = uipc_filt_sowrite,
.f_copy = knote_triv_copy,
};
static const struct filterops uipc_empty_filtops = {
.f_isfd = 1,
.f_detach = uipc_filt_sowdetach,
.f_event = uipc_filt_soempty,
.f_copy = knote_triv_copy,
};
static int
uipc_kqfilter_stream_or_seqpacket(struct socket *so, struct knote *kn)
{
struct unpcb *unp = sotounpcb(so);
struct knlist *knl;
switch (kn->kn_filter) {
case EVFILT_READ:
return (sokqfilter_generic(so, kn));
case EVFILT_WRITE:
kn->kn_fop = &uipc_write_filtops;
break;
case EVFILT_EMPTY:
kn->kn_fop = &uipc_empty_filtops;
break;
default:
return (EINVAL);
}
knl = &so->so_wrsel.si_note;
UNP_PCB_LOCK(unp);
if (SOLISTENING(so)) {
SOLISTEN_LOCK(so);
knlist_add(knl, kn, 1);
SOLISTEN_UNLOCK(so);
} else {
struct socket *so2 = so->so_rcv.uxst_peer;
if (so2 != NULL)
SOCK_RECVBUF_LOCK(so2);
knlist_add(knl, kn, 1);
if (so2 != NULL)
SOCK_RECVBUF_UNLOCK(so2);
}
UNP_PCB_UNLOCK(unp);
return (0);
}
/* PF_UNIX/SOCK_DGRAM version of sbspace() */
static inline bool
uipc_dgram_sbspace(struct sockbuf *sb, u_int cc, u_int mbcnt)
{
u_int bleft, mleft;
/*
* Negative space may happen if send(2) is followed by
* setsockopt(SO_SNDBUF/SO_RCVBUF) that shrinks maximum.
*/
if (__predict_false(sb->sb_hiwat < sb->uxdg_cc ||
sb->sb_mbmax < sb->uxdg_mbcnt))
return (false);
if (__predict_false(sb->sb_state & SBS_CANTRCVMORE))
return (false);
bleft = sb->sb_hiwat - sb->uxdg_cc;
mleft = sb->sb_mbmax - sb->uxdg_mbcnt;
return (bleft >= cc && mleft >= mbcnt);
}
/*
* PF_UNIX/SOCK_DGRAM send
*
* Allocate a record consisting of 3 mbufs in the sequence of
* from -> control -> data and append it to the socket buffer.
*
* The first mbuf carries sender's name and is a pkthdr that stores
* overall length of datagram, its memory consumption and control length.
*/
#define ctllen PH_loc.thirtytwo[1]
_Static_assert(offsetof(struct pkthdr, memlen) + sizeof(u_int) <=
offsetof(struct pkthdr, ctllen), "unix/dgram can not store ctllen");
static int
uipc_sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *m, struct mbuf *c, int flags, struct thread *td)
{
struct unpcb *unp, *unp2;
const struct sockaddr *from;
struct socket *so2;
struct sockbuf *sb;
struct mchain cmc = MCHAIN_INITIALIZER(&cmc);
struct mbuf *f;
u_int cc, ctl, mbcnt;
u_int dcc __diagused, dctl __diagused, dmbcnt __diagused;
int error;
MPASS((uio != NULL && m == NULL) || (m != NULL && uio == NULL));
error = 0;
f = NULL;
if (__predict_false(flags & MSG_OOB)) {
error = EOPNOTSUPP;
goto out;
}
if (m == NULL) {
if (__predict_false(uio->uio_resid > unpdg_maxdgram)) {
error = EMSGSIZE;
goto out;
}
m = m_uiotombuf(uio, M_WAITOK, 0, max_hdr, M_PKTHDR);
if (__predict_false(m == NULL)) {
error = EFAULT;
goto out;
}
f = m_gethdr(M_WAITOK, MT_SONAME);
cc = m->m_pkthdr.len;
mbcnt = MSIZE + m->m_pkthdr.memlen;
if (c != NULL && (error = unp_internalize(c, &cmc, td)))
goto out;
} else {
struct mchain mc;
uipc_reset_kernel_mbuf(m, &mc);
cc = mc.mc_len;
mbcnt = mc.mc_mlen;
if (__predict_false(m->m_pkthdr.len > unpdg_maxdgram)) {
error = EMSGSIZE;
goto out;
}
if ((f = m_gethdr(M_NOWAIT, MT_SONAME)) == NULL) {
error = ENOBUFS;
goto out;
}
}
unp = sotounpcb(so);
MPASS(unp);
/*
* XXXGL: would be cool to fully remove so_snd out of the equation
* and avoid this lock, which is not only extraneous, but also being
* released, thus still leaving possibility for a race. We can easily
* handle SBS_CANTSENDMORE/SS_ISCONNECTED complement in unpcb, but it
* is more difficult to invent something to handle so_error.
*/
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
if (error)
goto out2;
SOCK_SENDBUF_LOCK(so);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCK_SENDBUF_UNLOCK(so);
error = EPIPE;
goto out3;
}
if (so->so_error != 0) {
error = so->so_error;
so->so_error = 0;
SOCK_SENDBUF_UNLOCK(so);
goto out3;
}
if (((so->so_state & SS_ISCONNECTED) == 0) && addr == NULL) {
SOCK_SENDBUF_UNLOCK(so);
error = EDESTADDRREQ;
goto out3;
}
SOCK_SENDBUF_UNLOCK(so);
if (addr != NULL) {
if ((error = unp_connectat(AT_FDCWD, so, addr, td, true)))
goto out3;
UNP_PCB_LOCK_ASSERT(unp);
unp2 = unp->unp_conn;
UNP_PCB_LOCK_ASSERT(unp2);
} else {
UNP_PCB_LOCK(unp);
unp2 = unp_pcb_lock_peer(unp);
if (unp2 == NULL) {
UNP_PCB_UNLOCK(unp);
error = ENOTCONN;
goto out3;
}
}
if (unp2->unp_flags & UNP_WANTCRED_MASK)
unp_addsockcred(td, &cmc, unp2->unp_flags);
if (unp->unp_addr != NULL)
from = (struct sockaddr *)unp->unp_addr;
else
from = &sun_noname;
f->m_len = from->sa_len;
MPASS(from->sa_len <= MLEN);
bcopy(from, mtod(f, void *), from->sa_len);
/*
* Concatenate mbufs: from -> control -> data.
* Save overall cc and mbcnt in "from" mbuf.
*/
if (!STAILQ_EMPTY(&cmc.mc_q)) {
f->m_next = mc_first(&cmc);
mc_last(&cmc)->m_next = m;
/* XXXGL: This is dirty as well as rollback after ENOBUFS. */
STAILQ_INIT(&cmc.mc_q);
} else
f->m_next = m;
m = NULL;
ctl = f->m_len + cmc.mc_len;
mbcnt += cmc.mc_mlen;
#ifdef INVARIANTS
dcc = dctl = dmbcnt = 0;
for (struct mbuf *mb = f; mb != NULL; mb = mb->m_next) {
if (mb->m_type == MT_DATA)
dcc += mb->m_len;
else
dctl += mb->m_len;
dmbcnt += MSIZE;
if (mb->m_flags & M_EXT)
dmbcnt += mb->m_ext.ext_size;
}
MPASS(dcc == cc);
MPASS(dctl == ctl);
MPASS(dmbcnt == mbcnt);
#endif
f->m_pkthdr.len = cc + ctl;
f->m_pkthdr.memlen = mbcnt;
f->m_pkthdr.ctllen = ctl;
/*
* Destination socket buffer selection.
*
* Unconnected sends, when !(so->so_state & SS_ISCONNECTED) and the
* destination address is supplied, create a temporary connection for
* the run time of the function (see call to unp_connectat() above and
* to unp_disconnect() below). We distinguish them by condition of
* (addr != NULL). We intentionally avoid adding 'bool connected' for
* that condition, since, again, through the run time of this code we
* are always connected. For such "unconnected" sends, the destination
* buffer would be the receive buffer of destination socket so2.
*
* For connected sends, data lands on the send buffer of the sender's
* socket "so". Then, if we just added the very first datagram
* on this send buffer, we need to add the send buffer on to the
* receiving socket's buffer list. We put ourselves on top of the
* list. Such logic gives infrequent senders priority over frequent
* senders.
*
* Note on byte count management. As long as event methods kevent(2),
* select(2) are not protocol specific (yet), we need to maintain
* meaningful values on the receive buffer. So, the receive buffer
* would accumulate counters from all connected buffers potentially
* having sb_ccc > sb_hiwat or sb_mbcnt > sb_mbmax.
*/
so2 = unp2->unp_socket;
sb = (addr == NULL) ? &so->so_snd : &so2->so_rcv;
SOCK_RECVBUF_LOCK(so2);
if (uipc_dgram_sbspace(sb, cc + ctl, mbcnt)) {
if (addr == NULL && STAILQ_EMPTY(&sb->uxdg_mb))
TAILQ_INSERT_HEAD(&so2->so_rcv.uxdg_conns, &so->so_snd,
uxdg_clist);
STAILQ_INSERT_TAIL(&sb->uxdg_mb, f, m_stailqpkt);
sb->uxdg_cc += cc + ctl;
sb->uxdg_ctl += ctl;
sb->uxdg_mbcnt += mbcnt;
so2->so_rcv.sb_acc += cc + ctl;
so2->so_rcv.sb_ccc += cc + ctl;
so2->so_rcv.sb_ctl += ctl;
so2->so_rcv.sb_mbcnt += mbcnt;
sorwakeup_locked(so2);
f = NULL;
} else {
soroverflow_locked(so2);
error = ENOBUFS;
if (f->m_next->m_type == MT_CONTROL) {
STAILQ_FIRST(&cmc.mc_q) = f->m_next;
f->m_next = NULL;
}
}
if (addr != NULL)
unp_disconnect(unp, unp2);
else
unp_pcb_unlock_pair(unp, unp2);
td->td_ru.ru_msgsnd++;
out3:
SOCK_IO_SEND_UNLOCK(so);
out2:
if (!mc_empty(&cmc))
unp_scan(mc_first(&cmc), unp_freerights);
out:
if (f)
m_freem(f);
mc_freem(&cmc);
if (m)
m_freem(m);
return (error);
}
/*
* PF_UNIX/SOCK_DGRAM receive with MSG_PEEK.
* The mbuf has already been unlinked from the uxdg_mb of socket buffer
* and needs to be linked onto uxdg_peeked of receive socket buffer.
*/
static int
uipc_peek_dgram(struct socket *so, struct mbuf *m, struct sockaddr **psa,
struct uio *uio, struct mbuf **controlp, int *flagsp)
{
ssize_t len = 0;
int error;
so->so_rcv.uxdg_peeked = m;
so->so_rcv.uxdg_cc += m->m_pkthdr.len;
so->so_rcv.uxdg_ctl += m->m_pkthdr.ctllen;
so->so_rcv.uxdg_mbcnt += m->m_pkthdr.memlen;
SOCK_RECVBUF_UNLOCK(so);
KASSERT(m->m_type == MT_SONAME, ("m->m_type == %d", m->m_type));
if (psa != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *), M_WAITOK);
m = m->m_next;
KASSERT(m, ("%s: no data or control after soname", __func__));
/*
* With MSG_PEEK the control isn't executed, just copied.
*/
while (m != NULL && m->m_type == MT_CONTROL) {
if (controlp != NULL) {
*controlp = m_copym(m, 0, m->m_len, M_WAITOK);
controlp = &(*controlp)->m_next;
}
m = m->m_next;
}
KASSERT(m == NULL || m->m_type == MT_DATA,
("%s: not MT_DATA mbuf %p", __func__, m));
while (m != NULL && uio->uio_resid > 0) {
len = uio->uio_resid;
if (len > m->m_len)
len = m->m_len;
error = uiomove(mtod(m, char *), (int)len, uio);
if (error) {
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
if (len == m->m_len)
m = m->m_next;
}
SOCK_IO_RECV_UNLOCK(so);
if (flagsp != NULL) {
if (m != NULL) {
if (*flagsp & MSG_TRUNC) {
/* Report real length of the packet */
uio->uio_resid -= m_length(m, NULL) - len;
}
*flagsp |= MSG_TRUNC;
} else
*flagsp &= ~MSG_TRUNC;
}
return (0);
}
/*
* PF_UNIX/SOCK_DGRAM receive
*/
static int
uipc_soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
struct sockbuf *sb = NULL;
struct mbuf *m;
int flags, error;
ssize_t len = 0;
bool nonblock;
MPASS(mp0 == NULL);
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
flags = flagsp != NULL ? *flagsp : 0;
nonblock = (so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT | MSG_NBIO));
error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
if (__predict_false(error))
return (error);
/*
* Loop blocking while waiting for a datagram. Prioritize connected
* peers over unconnected sends. Set sb to selected socket buffer
* containing an mbuf on exit from the wait loop. A datagram that
* had already been peeked at has top priority.
*/
SOCK_RECVBUF_LOCK(so);
while ((m = so->so_rcv.uxdg_peeked) == NULL &&
(sb = TAILQ_FIRST(&so->so_rcv.uxdg_conns)) == NULL &&
(m = STAILQ_FIRST(&so->so_rcv.uxdg_mb)) == NULL) {
if (so->so_error) {
error = so->so_error;
if (!(flags & MSG_PEEK))
so->so_error = 0;
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
uio->uio_resid == 0) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (0);
}
if (nonblock) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (EWOULDBLOCK);
}
error = sbwait(so, SO_RCV);
if (error) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
}
if (sb == NULL)
sb = &so->so_rcv;
else if (m == NULL)
m = STAILQ_FIRST(&sb->uxdg_mb);
else
MPASS(m == so->so_rcv.uxdg_peeked);
MPASS(sb->uxdg_cc > 0);
M_ASSERTPKTHDR(m);
KASSERT(m->m_type == MT_SONAME, ("m->m_type == %d", m->m_type));
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
if (__predict_true(m != so->so_rcv.uxdg_peeked)) {
STAILQ_REMOVE_HEAD(&sb->uxdg_mb, m_stailqpkt);
if (STAILQ_EMPTY(&sb->uxdg_mb) && sb != &so->so_rcv)
TAILQ_REMOVE(&so->so_rcv.uxdg_conns, sb, uxdg_clist);
} else
so->so_rcv.uxdg_peeked = NULL;
sb->uxdg_cc -= m->m_pkthdr.len;
sb->uxdg_ctl -= m->m_pkthdr.ctllen;
sb->uxdg_mbcnt -= m->m_pkthdr.memlen;
if (__predict_false(flags & MSG_PEEK))
return (uipc_peek_dgram(so, m, psa, uio, controlp, flagsp));
so->so_rcv.sb_acc -= m->m_pkthdr.len;
so->so_rcv.sb_ccc -= m->m_pkthdr.len;
so->so_rcv.sb_ctl -= m->m_pkthdr.ctllen;
so->so_rcv.sb_mbcnt -= m->m_pkthdr.memlen;
SOCK_RECVBUF_UNLOCK(so);
if (psa != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *), M_WAITOK);
m = m_free(m);
KASSERT(m, ("%s: no data or control after soname", __func__));
/*
* Packet to copyout() is now in 'm' and it is disconnected from the
* queue.
*
* Process one or more MT_CONTROL mbufs present before any data mbufs
* in the first mbuf chain on the socket buffer. We call into the
* unp_externalize() to perform externalization (or freeing if
* controlp == NULL). In some cases there can be only MT_CONTROL mbufs
* without MT_DATA mbufs.
*/
while (m != NULL && m->m_type == MT_CONTROL) {
error = unp_externalize(m, controlp, flags);
m = m_free(m);
if (error != 0) {
SOCK_IO_RECV_UNLOCK(so);
unp_scan(m, unp_freerights);
m_freem(m);
return (error);
}
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
}
KASSERT(m == NULL || m->m_type == MT_DATA,
("%s: not MT_DATA mbuf %p", __func__, m));
while (m != NULL && uio->uio_resid > 0) {
len = uio->uio_resid;
if (len > m->m_len)
len = m->m_len;
error = uiomove(mtod(m, char *), (int)len, uio);
if (error) {
SOCK_IO_RECV_UNLOCK(so);
m_freem(m);
return (error);
}
if (len == m->m_len)
m = m_free(m);
else {
m->m_data += len;
m->m_len -= len;
}
}
SOCK_IO_RECV_UNLOCK(so);
if (m != NULL) {
if (flagsp != NULL) {
if (flags & MSG_TRUNC) {
/* Report real length of the packet */
uio->uio_resid -= m_length(m, NULL);
}
*flagsp |= MSG_TRUNC;
}
m_freem(m);
} else if (flagsp != NULL)
*flagsp &= ~MSG_TRUNC;
return (0);
}
static int
uipc_sendfile_wait(struct socket *so, off_t need, int *space)
{
struct unpcb *unp2;
struct socket *so2;
struct sockbuf *sb;
bool nonblock, sockref;
int error;
MPASS(so->so_type == SOCK_STREAM);
MPASS(need > 0);
MPASS(space != NULL);
nonblock = so->so_state & SS_NBIO;
sockref = false;
if (__predict_false((so->so_state & SS_ISCONNECTED) == 0))
return (ENOTCONN);
if (__predict_false((error = uipc_lock_peer(so, &unp2)) != 0))
return (error);
so2 = unp2->unp_socket;
sb = &so2->so_rcv;
SOCK_RECVBUF_LOCK(so2);
UNP_PCB_UNLOCK(unp2);
while ((*space = uipc_stream_sbspace(sb)) < need &&
(*space < so->so_snd.sb_hiwat / 2)) {
UIPC_STREAM_SBCHECK(sb);
if (nonblock) {
SOCK_RECVBUF_UNLOCK(so2);
return (EAGAIN);
}
if (!sockref)
soref(so2);
error = uipc_stream_sbwait(so2, so->so_snd.sb_timeo);
if (error == 0 &&
__predict_false(sb->sb_state & SBS_CANTRCVMORE))
error = EPIPE;
if (error) {
SOCK_RECVBUF_UNLOCK(so2);
sorele(so2);
return (error);
}
}
UIPC_STREAM_SBCHECK(sb);
SOCK_RECVBUF_UNLOCK(so2);
if (sockref)
sorele(so2);
return (0);
}
/*
* Although this is a pr_send method, for unix(4) it is called only via
* sendfile(2) path. This means we can be sure that mbufs are clear of
* any extra flags and don't require any conditioning.
*/
static int
uipc_sendfile(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *from, struct mbuf *control, struct thread *td)
{
struct mchain mc;
struct unpcb *unp2;
struct socket *so2;
struct sockbuf *sb;
bool notready, wakeup;
int error;
MPASS(so->so_type == SOCK_STREAM);
MPASS(from == NULL && control == NULL);
KASSERT(!(m->m_flags & M_EXTPG),
("unix(4): TLS sendfile(2) not supported"));
notready = flags & PRUS_NOTREADY;
if (__predict_false((so->so_state & SS_ISCONNECTED) == 0)) {
error = ENOTCONN;
goto out;
}
if (__predict_false((error = uipc_lock_peer(so, &unp2)) != 0))
goto out;
mc_init_m(&mc, m);
so2 = unp2->unp_socket;
sb = &so2->so_rcv;
SOCK_RECVBUF_LOCK(so2);
UNP_PCB_UNLOCK(unp2);
UIPC_STREAM_SBCHECK(sb);
sb->sb_ccc += mc.mc_len;
sb->sb_mbcnt += mc.mc_mlen;
if (sb->uxst_fnrdy == NULL) {
if (notready) {
wakeup = false;
STAILQ_FOREACH(m, &mc.mc_q, m_stailq) {
if (m->m_flags & M_NOTREADY) {
sb->uxst_fnrdy = m;
break;
} else {
sb->sb_acc += m->m_len;
wakeup = true;
}
}
} else {
wakeup = true;
sb->sb_acc += mc.mc_len;
}
} else {
wakeup = false;
}
STAILQ_CONCAT(&sb->uxst_mbq, &mc.mc_q);
UIPC_STREAM_SBCHECK(sb);
if (wakeup)
sorwakeup_locked(so2);
else
SOCK_RECVBUF_UNLOCK(so2);
return (0);
out:
/*
* In case of not ready data, uipc_ready() is responsible
* for freeing memory.
*/
if (m != NULL && !notready)
m_freem(m);
return (error);
}
static int
uipc_sbready(struct sockbuf *sb, struct mbuf *m, int count)
{
bool blocker;
/* assert locked */
blocker = (sb->uxst_fnrdy == m);
STAILQ_FOREACH_FROM(m, &sb->uxst_mbq, m_stailq) {
if (count > 0) {
MPASS(m->m_flags & M_NOTREADY);
m->m_flags &= ~M_NOTREADY;
if (blocker)
sb->sb_acc += m->m_len;
count--;
} else if (m->m_flags & M_NOTREADY)
break;
else if (blocker)
sb->sb_acc += m->m_len;
}
if (blocker) {
sb->uxst_fnrdy = m;
return (0);
} else
return (EINPROGRESS);
}
static bool
uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp)
{
struct mbuf *mb;
struct sockbuf *sb;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
SOCK_UNLOCK(so);
return (false);
}
mb = NULL;
sb = &so->so_rcv;
SOCK_RECVBUF_LOCK(so);
if (sb->uxst_fnrdy != NULL) {
STAILQ_FOREACH(mb, &sb->uxst_mbq, m_stailq) {
if (mb == m) {
*errorp = uipc_sbready(sb, m, count);
break;
}
}
}
SOCK_RECVBUF_UNLOCK(so);
SOCK_UNLOCK(so);
return (mb != NULL);
}
static int
uipc_ready(struct socket *so, struct mbuf *m, int count)
{
struct unpcb *unp, *unp2;
int error;
MPASS(so->so_type == SOCK_STREAM);
if (__predict_true(uipc_lock_peer(so, &unp2) == 0)) {
struct socket *so2;
struct sockbuf *sb;
so2 = unp2->unp_socket;
sb = &so2->so_rcv;
SOCK_RECVBUF_LOCK(so2);
UNP_PCB_UNLOCK(unp2);
UIPC_STREAM_SBCHECK(sb);
error = uipc_sbready(sb, m, count);
UIPC_STREAM_SBCHECK(sb);
if (error == 0)
sorwakeup_locked(so2);
else
SOCK_RECVBUF_UNLOCK(so2);
} else {
/*
* The receiving socket has been disconnected, but may still
* be valid. In this case, the not-ready mbufs are still
* present in its socket buffer, so perform an exhaustive
* search before giving up and freeing the mbufs.
*/
UNP_LINK_RLOCK();
LIST_FOREACH(unp, &unp_shead, unp_link) {
if (uipc_ready_scan(unp->unp_socket, m, count, &error))
break;
}
UNP_LINK_RUNLOCK();
if (unp == NULL) {
for (int i = 0; i < count; i++)
m = m_free(m);
return (ECONNRESET);
}
}
return (error);
}
static int
uipc_sense(struct socket *so, struct stat *sb)
{
struct unpcb *unp;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
sb->st_blksize = so->so_snd.sb_hiwat;
sb->st_dev = NODEV;
sb->st_ino = unp->unp_ino;
return (0);
}
static int
uipc_shutdown(struct socket *so, enum shutdown_how how)
{
struct unpcb *unp = sotounpcb(so);
int error;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
if (how != SHUT_WR) {
so->so_error = ECONNABORTED;
solisten_wakeup(so); /* unlocks so */
} else
SOCK_UNLOCK(so);
return (ENOTCONN);
} else if ((so->so_state &
(SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0) {
/*
* POSIX mandates us to just return ENOTCONN when shutdown(2) is
* invoked on a datagram sockets, however historically we would
* actually tear socket down. This is known to be leveraged by
* some applications to unblock process waiting in recv(2) by
* other process that it shares that socket with. Try to meet
* both backward-compatibility and POSIX requirements by forcing
* ENOTCONN but still flushing buffers and performing wakeup(9).
*
* XXXGL: it remains unknown what applications expect this
* behavior and is this isolated to unix/dgram or inet/dgram or
* both. See: D10351, D3039.
*/
error = ENOTCONN;
if (so->so_type != SOCK_DGRAM) {
SOCK_UNLOCK(so);
return (error);
}
} else
error = 0;
SOCK_UNLOCK(so);
switch (how) {
case SHUT_RD:
if (so->so_type == SOCK_DGRAM)
socantrcvmore(so);
else
uipc_cantrcvmore(so);
unp_dispose(so);
break;
case SHUT_RDWR:
if (so->so_type == SOCK_DGRAM)
socantrcvmore(so);
else
uipc_cantrcvmore(so);
unp_dispose(so);
/* FALLTHROUGH */
case SHUT_WR:
if (so->so_type == SOCK_DGRAM) {
socantsendmore(so);
} else {
UNP_PCB_LOCK(unp);
if (unp->unp_conn != NULL)
uipc_cantrcvmore(unp->unp_conn->unp_socket);
UNP_PCB_UNLOCK(unp);
}
}
wakeup(&so->so_timeo);
return (error);
}
static int
uipc_sockaddr(struct socket *so, struct sockaddr *ret)
{
struct unpcb *unp;
const struct sockaddr *sa;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
UNP_PCB_LOCK(unp);
if (unp->unp_addr != NULL)
sa = (struct sockaddr *) unp->unp_addr;
else
sa = &sun_noname;
bcopy(sa, ret, sa->sa_len);
UNP_PCB_UNLOCK(unp);
return (0);
}
static int
uipc_ctloutput(struct socket *so, struct sockopt *sopt)
{
struct unpcb *unp;
struct xucred xu;
int error, optval;
if (sopt->sopt_level != SOL_LOCAL)
return (EINVAL);
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
error = 0;
switch (sopt->sopt_dir) {
case SOPT_GET:
switch (sopt->sopt_name) {
case LOCAL_PEERCRED:
UNP_PCB_LOCK(unp);
if (unp->unp_flags & UNP_HAVEPC)
xu = unp->unp_peercred;
else {
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EINVAL;
}
UNP_PCB_UNLOCK(unp);
if (error == 0)
error = sooptcopyout(sopt, &xu, sizeof(xu));
break;
case LOCAL_CREDS:
/* Unlocked read. */
optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0;
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
case LOCAL_CREDS_PERSISTENT:
/* Unlocked read. */
optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0;
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
default:
error = EOPNOTSUPP;
break;
}
break;
case SOPT_SET:
switch (sopt->sopt_name) {
case LOCAL_CREDS:
case LOCAL_CREDS_PERSISTENT:
error = sooptcopyin(sopt, &optval, sizeof(optval),
sizeof(optval));
if (error)
break;
#define OPTSET(bit, exclusive) do { \
UNP_PCB_LOCK(unp); \
if (optval) { \
if ((unp->unp_flags & (exclusive)) != 0) { \
UNP_PCB_UNLOCK(unp); \
error = EINVAL; \
break; \
} \
unp->unp_flags |= (bit); \
} else \
unp->unp_flags &= ~(bit); \
UNP_PCB_UNLOCK(unp); \
} while (0)
switch (sopt->sopt_name) {
case LOCAL_CREDS:
OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS);
break;
case LOCAL_CREDS_PERSISTENT:
OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT);
break;
default:
break;
}
break;
#undef OPTSET
default:
error = ENOPROTOOPT;
break;
}
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (unp_connectat(AT_FDCWD, so, nam, td, false));
}
static int
unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
struct thread *td, bool return_locked)
{
struct mtx *vplock;
struct sockaddr_un *soun;
struct vnode *vp;
struct socket *so2;
struct unpcb *unp, *unp2, *unp3;
struct nameidata nd;
char buf[SOCK_MAXADDRLEN];
struct sockaddr *sa;
cap_rights_t rights;
int error, len;
bool connreq;
CURVNET_ASSERT_SET();
if (nam->sa_family != AF_UNIX)
return (EAFNOSUPPORT);
if (nam->sa_len > sizeof(struct sockaddr_un))
return (EINVAL);
len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
if (len <= 0)
return (EINVAL);
soun = (struct sockaddr_un *)nam;
bcopy(soun->sun_path, buf, len);
buf[len] = 0;
error = 0;
unp = sotounpcb(so);
UNP_PCB_LOCK(unp);
for (;;) {
/*
* Wait for connection state to stabilize. If a connection
* already exists, give up. For datagram sockets, which permit
* multiple consecutive connect(2) calls, upper layers are
* responsible for disconnecting in advance of a subsequent
* connect(2), but this is not synchronized with PCB connection
* state.
*
* Also make sure that no threads are currently attempting to
* lock the peer socket, to ensure that unp_conn cannot
* transition between two valid sockets while locks are dropped.
*/
if (SOLISTENING(so))
error = EOPNOTSUPP;
else if (unp->unp_conn != NULL)
error = EISCONN;
else if ((unp->unp_flags & UNP_CONNECTING) != 0) {
error = EALREADY;
}
if (error != 0) {
UNP_PCB_UNLOCK(unp);
return (error);
}
if (unp->unp_pairbusy > 0) {
unp->unp_flags |= UNP_WAITING;
mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0);
continue;
}
break;
}
unp->unp_flags |= UNP_CONNECTING;
UNP_PCB_UNLOCK(unp);
connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0;
if (connreq)
sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
else
sa = NULL;
NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT));
error = namei(&nd);
if (error)
vp = NULL;
else
vp = nd.ni_vp;
ASSERT_VOP_LOCKED(vp, "unp_connect");
if (error)
goto bad;
NDFREE_PNBUF(&nd);
if (vp->v_type != VSOCK) {
error = ENOTSOCK;
goto bad;
}
#ifdef MAC
error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
if (error)
goto bad;
#endif
error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
if (error)
goto bad;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
vplock = mtx_pool_find(unp_vp_mtxpool, vp);
mtx_lock(vplock);
VOP_UNP_CONNECT(vp, &unp2);
if (unp2 == NULL) {
error = ECONNREFUSED;
goto bad2;
}
so2 = unp2->unp_socket;
if (so->so_type != so2->so_type) {
error = EPROTOTYPE;
goto bad2;
}
if (connreq) {
if (SOLISTENING(so2))
so2 = solisten_clone(so2);
else
so2 = NULL;
if (so2 == NULL) {
error = ECONNREFUSED;
goto bad2;
}
if ((error = uipc_attach(so2, 0, NULL)) != 0) {
sodealloc(so2);
goto bad2;
}
unp3 = sotounpcb(so2);
unp_pcb_lock_pair(unp2, unp3);
if (unp2->unp_addr != NULL) {
bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
unp3->unp_addr = (struct sockaddr_un *) sa;
sa = NULL;
}
unp_copy_peercred(td, unp3, unp, unp2);
UNP_PCB_UNLOCK(unp2);
unp2 = unp3;
/*
* It is safe to block on the PCB lock here since unp2 is
* nascent and cannot be connected to any other sockets.
*/
UNP_PCB_LOCK(unp);
#ifdef MAC
mac_socketpeer_set_from_socket(so, so2);
mac_socketpeer_set_from_socket(so2, so);
#endif
} else {
unp_pcb_lock_pair(unp, unp2);
}
KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 &&
sotounpcb(so2) == unp2,
("%s: unp2 %p so2 %p", __func__, unp2, so2));
unp_connect2(so, so2, connreq);
if (connreq)
(void)solisten_enqueue(so2, SS_ISCONNECTED);
KASSERT((unp->unp_flags & UNP_CONNECTING) != 0,
("%s: unp %p has UNP_CONNECTING clear", __func__, unp));
unp->unp_flags &= ~UNP_CONNECTING;
if (!return_locked)
unp_pcb_unlock_pair(unp, unp2);
bad2:
mtx_unlock(vplock);
bad:
if (vp != NULL) {
/*
* If we are returning locked (called via uipc_sosend_dgram()),
* we need to be sure that vput() won't sleep. This is
* guaranteed by VOP_UNP_CONNECT() call above and unp2 lock.
* SOCK_STREAM/SEQPACKET can't request return_locked (yet).
*/
MPASS(!(return_locked && connreq));
vput(vp);
}
free(sa, M_SONAME);
if (__predict_false(error)) {
UNP_PCB_LOCK(unp);
KASSERT((unp->unp_flags & UNP_CONNECTING) != 0,
("%s: unp %p has UNP_CONNECTING clear", __func__, unp));
unp->unp_flags &= ~UNP_CONNECTING;
UNP_PCB_UNLOCK(unp);
}
return (error);
}
/*
* Set socket peer credentials at connection time.
*
* The client's PCB credentials are copied from its process structure. The
* server's PCB credentials are copied from the socket on which it called
* listen(2). uipc_listen cached that process's credentials at the time.
*/
void
unp_copy_peercred(struct thread *td, struct unpcb *client_unp,
struct unpcb *server_unp, struct unpcb *listen_unp)
{
cru2xt(td, &client_unp->unp_peercred);
client_unp->unp_flags |= UNP_HAVEPC;
memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred,
sizeof(server_unp->unp_peercred));
server_unp->unp_flags |= UNP_HAVEPC;
client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK);
}
/*
* unix/stream & unix/seqpacket version of soisconnected().
*
* The crucial thing we are doing here is setting up the uxst_peer linkage,
* holding unp and receive buffer locks of the both sockets. The disconnect
* procedure does the same. This gives as a safe way to access the peer in the
* send(2) and recv(2) during the socket lifetime.
*
* The less important thing is event notification of the fact that a socket is
* now connected. It is unusual for a software to put a socket into event
* mechanism before connect(2), but is supposed to be supported. Note that
* there can not be any sleeping I/O on the socket, yet, only presence in the
* select/poll/kevent.
*
* This function can be called via two call paths:
* 1) socketpair(2) - in this case socket has not been yet reported to userland
* and just can't have any event notifications mechanisms set up. The
* 'wakeup' boolean is always false.
* 2) connect(2) of existing socket to a recent clone of a listener:
* 2.1) Socket that connect(2)s will have 'wakeup' true. An application
* could have already put it into event mechanism, is it shall be
* reported as readable and as writable.
* 2.2) Socket that was just cloned with solisten_clone(). Same as 1).
*/
static void
unp_soisconnected(struct socket *so, bool wakeup)
{
struct socket *so2 = sotounpcb(so)->unp_conn->unp_socket;
struct sockbuf *sb;
SOCK_LOCK_ASSERT(so);
UNP_PCB_LOCK_ASSERT(sotounpcb(so));
UNP_PCB_LOCK_ASSERT(sotounpcb(so2));
SOCK_RECVBUF_LOCK_ASSERT(so);
SOCK_RECVBUF_LOCK_ASSERT(so2);
MPASS(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET);
MPASS((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
SS_ISDISCONNECTING)) == 0);
MPASS(so->so_qstate == SQ_NONE);
so->so_state &= ~SS_ISDISCONNECTED;
so->so_state |= SS_ISCONNECTED;
sb = &so2->so_rcv;
sb->uxst_peer = so;
if (wakeup) {
KNOTE_LOCKED(&sb->sb_sel->si_note, 0);
sb = &so->so_rcv;
selwakeuppri(sb->sb_sel, PSOCK);
SOCK_SENDBUF_LOCK_ASSERT(so);
sb = &so->so_snd;
selwakeuppri(sb->sb_sel, PSOCK);
SOCK_SENDBUF_UNLOCK(so);
}
}
static void
unp_connect2(struct socket *so, struct socket *so2, bool wakeup)
{
struct unpcb *unp;
struct unpcb *unp2;
MPASS(so2->so_type == so->so_type);
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
unp2 = sotounpcb(so2);
KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
UNP_PCB_LOCK_ASSERT(unp);
UNP_PCB_LOCK_ASSERT(unp2);
KASSERT(unp->unp_conn == NULL,
("%s: socket %p is already connected", __func__, unp));
unp->unp_conn = unp2;
unp_pcb_hold(unp2);
unp_pcb_hold(unp);
switch (so->so_type) {
case SOCK_DGRAM:
UNP_REF_LIST_LOCK();
LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
UNP_REF_LIST_UNLOCK();
soisconnected(so);
break;
case SOCK_STREAM:
case SOCK_SEQPACKET:
KASSERT(unp2->unp_conn == NULL,
("%s: socket %p is already connected", __func__, unp2));
unp2->unp_conn = unp;
SOCK_LOCK(so);
SOCK_LOCK(so2);
if (wakeup) /* Avoid LOR with receive buffer lock. */
SOCK_SENDBUF_LOCK(so);
SOCK_RECVBUF_LOCK(so);
SOCK_RECVBUF_LOCK(so2);
unp_soisconnected(so, wakeup); /* Will unlock send buffer. */
unp_soisconnected(so2, false);
SOCK_RECVBUF_UNLOCK(so);
SOCK_RECVBUF_UNLOCK(so2);
SOCK_UNLOCK(so);
SOCK_UNLOCK(so2);
break;
default:
panic("unp_connect2");
}
}
static void
unp_soisdisconnected(struct socket *so)
{
SOCK_LOCK_ASSERT(so);
SOCK_RECVBUF_LOCK_ASSERT(so);
MPASS(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET);
MPASS(!SOLISTENING(so));
MPASS((so->so_state & (SS_ISCONNECTING | SS_ISDISCONNECTING |
SS_ISDISCONNECTED)) == 0);
MPASS(so->so_state & SS_ISCONNECTED);
so->so_state |= SS_ISDISCONNECTED;
so->so_state &= ~SS_ISCONNECTED;
so->so_rcv.uxst_peer = NULL;
socantrcvmore_locked(so);
}
static void
unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
{
struct socket *so, *so2;
struct mbuf *m = NULL;
#ifdef INVARIANTS
struct unpcb *unptmp;
#endif
UNP_PCB_LOCK_ASSERT(unp);
UNP_PCB_LOCK_ASSERT(unp2);
KASSERT(unp->unp_conn == unp2,
("%s: unpcb %p is not connected to %p", __func__, unp, unp2));
unp->unp_conn = NULL;
so = unp->unp_socket;
so2 = unp2->unp_socket;
switch (unp->unp_socket->so_type) {
case SOCK_DGRAM:
/*
* Remove our send socket buffer from the peer's receive buffer.
* Move the data to the receive buffer only if it is empty.
* This is a protection against a scenario where a peer
* connects, floods and disconnects, effectively blocking
* sendto() from unconnected sockets.
*/
SOCK_RECVBUF_LOCK(so2);
if (!STAILQ_EMPTY(&so->so_snd.uxdg_mb)) {
TAILQ_REMOVE(&so2->so_rcv.uxdg_conns, &so->so_snd,
uxdg_clist);
if (__predict_true((so2->so_rcv.sb_state &
SBS_CANTRCVMORE) == 0) &&
STAILQ_EMPTY(&so2->so_rcv.uxdg_mb)) {
STAILQ_CONCAT(&so2->so_rcv.uxdg_mb,
&so->so_snd.uxdg_mb);
so2->so_rcv.uxdg_cc += so->so_snd.uxdg_cc;
so2->so_rcv.uxdg_ctl += so->so_snd.uxdg_ctl;
so2->so_rcv.uxdg_mbcnt += so->so_snd.uxdg_mbcnt;
} else {
m = STAILQ_FIRST(&so->so_snd.uxdg_mb);
STAILQ_INIT(&so->so_snd.uxdg_mb);
so2->so_rcv.sb_acc -= so->so_snd.uxdg_cc;
so2->so_rcv.sb_ccc -= so->so_snd.uxdg_cc;
so2->so_rcv.sb_ctl -= so->so_snd.uxdg_ctl;
so2->so_rcv.sb_mbcnt -= so->so_snd.uxdg_mbcnt;
}
/* Note: so may reconnect. */
so->so_snd.uxdg_cc = 0;
so->so_snd.uxdg_ctl = 0;
so->so_snd.uxdg_mbcnt = 0;
}
SOCK_RECVBUF_UNLOCK(so2);
UNP_REF_LIST_LOCK();
#ifdef INVARIANTS
LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) {
if (unptmp == unp)
break;
}
KASSERT(unptmp != NULL,
("%s: %p not found in reflist of %p", __func__, unp, unp2));
#endif
LIST_REMOVE(unp, unp_reflink);
UNP_REF_LIST_UNLOCK();
SOCK_LOCK(so);
so->so_state &= ~SS_ISCONNECTED;
SOCK_UNLOCK(so);
break;
case SOCK_STREAM:
case SOCK_SEQPACKET:
SOCK_LOCK(so);
SOCK_LOCK(so2);
SOCK_RECVBUF_LOCK(so);
SOCK_RECVBUF_LOCK(so2);
unp_soisdisconnected(so);
MPASS(unp2->unp_conn == unp);
unp2->unp_conn = NULL;
unp_soisdisconnected(so2);
SOCK_UNLOCK(so);
SOCK_UNLOCK(so2);
break;
}
if (unp == unp2) {
unp_pcb_rele_notlast(unp);
if (!unp_pcb_rele(unp))
UNP_PCB_UNLOCK(unp);
} else {
if (!unp_pcb_rele(unp))
UNP_PCB_UNLOCK(unp);
if (!unp_pcb_rele(unp2))
UNP_PCB_UNLOCK(unp2);
}
if (m != NULL) {
unp_scan(m, unp_freerights);
m_freemp(m);
}
}
/*
* unp_pcblist() walks the global list of struct unpcb's to generate a
* pointer list, bumping the refcount on each unpcb. It then copies them out
* sequentially, validating the generation number on each to see if it has
* been detached. All of this is necessary because copyout() may sleep on
* disk I/O.
*/
static int
unp_pcblist(SYSCTL_HANDLER_ARGS)
{
struct unpcb *unp, **unp_list;
unp_gen_t gencnt;
struct xunpgen *xug;
struct unp_head *head;
struct xunpcb *xu;
u_int i;
int error, n;
switch ((intptr_t)arg1) {
case SOCK_STREAM:
head = &unp_shead;
break;
case SOCK_DGRAM:
head = &unp_dhead;
break;
case SOCK_SEQPACKET:
head = &unp_sphead;
break;
default:
panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
}
/*
* The process of preparing the PCB list is too time-consuming and
* resource-intensive to repeat twice on every request.
*/
if (req->oldptr == NULL) {
n = unp_count;
req->oldidx = 2 * (sizeof *xug)
+ (n + n/8) * sizeof(struct xunpcb);
return (0);
}
if (req->newptr != NULL)
return (EPERM);
/*
* OK, now we're committed to doing something.
*/
xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO);
UNP_LINK_RLOCK();
gencnt = unp_gencnt;
n = unp_count;
UNP_LINK_RUNLOCK();
xug->xug_len = sizeof *xug;
xug->xug_count = n;
xug->xug_gen = gencnt;
xug->xug_sogen = so_gencnt;
error = SYSCTL_OUT(req, xug, sizeof *xug);
if (error) {
free(xug, M_TEMP);
return (error);
}
unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
UNP_LINK_RLOCK();
for (unp = LIST_FIRST(head), i = 0; unp && i < n;
unp = LIST_NEXT(unp, unp_link)) {
UNP_PCB_LOCK(unp);
if (unp->unp_gencnt <= gencnt) {
if (cr_cansee(req->td->td_ucred,
unp->unp_socket->so_cred)) {
UNP_PCB_UNLOCK(unp);
continue;
}
unp_list[i++] = unp;
unp_pcb_hold(unp);
}
UNP_PCB_UNLOCK(unp);
}
UNP_LINK_RUNLOCK();
n = i; /* In case we lost some during malloc. */
error = 0;
xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
for (i = 0; i < n; i++) {
unp = unp_list[i];
UNP_PCB_LOCK(unp);
if (unp_pcb_rele(unp))
continue;
if (unp->unp_gencnt <= gencnt) {
xu->xu_len = sizeof *xu;
xu->xu_unpp = (uintptr_t)unp;
/*
* XXX - need more locking here to protect against
* connect/disconnect races for SMP.
*/
if (unp->unp_addr != NULL)
bcopy(unp->unp_addr, &xu->xu_addr,
unp->unp_addr->sun_len);
else
bzero(&xu->xu_addr, sizeof(xu->xu_addr));
if (unp->unp_conn != NULL &&
unp->unp_conn->unp_addr != NULL)
bcopy(unp->unp_conn->unp_addr,
&xu->xu_caddr,
unp->unp_conn->unp_addr->sun_len);
else
bzero(&xu->xu_caddr, sizeof(xu->xu_caddr));
xu->unp_vnode = (uintptr_t)unp->unp_vnode;
xu->unp_conn = (uintptr_t)unp->unp_conn;
xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs);
xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink);
xu->unp_gencnt = unp->unp_gencnt;
sotoxsocket(unp->unp_socket, &xu->xu_socket);
UNP_PCB_UNLOCK(unp);
error = SYSCTL_OUT(req, xu, sizeof *xu);
} else {
UNP_PCB_UNLOCK(unp);
}
}
free(xu, M_TEMP);
if (!error) {
/*
* Give the user an updated idea of our state. If the
* generation differs from what we told her before, she knows
* that something happened while we were processing this
* request, and it might be necessary to retry.
*/
xug->xug_gen = unp_gencnt;
xug->xug_sogen = so_gencnt;
xug->xug_count = unp_count;
error = SYSCTL_OUT(req, xug, sizeof *xug);
}
free(unp_list, M_TEMP);
free(xug, M_TEMP);
return (error);
}
SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
(void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
"List of active local datagram sockets");
SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
(void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
"List of active local stream sockets");
SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
(void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
"List of active local seqpacket sockets");
static void
unp_drop(struct unpcb *unp)
{
struct socket *so;
struct unpcb *unp2;
/*
* Regardless of whether the socket's peer dropped the connection
* with this socket by aborting or disconnecting, POSIX requires
* that ECONNRESET is returned on next connected send(2) in case of
* a SOCK_DGRAM socket and EPIPE for SOCK_STREAM.
*/
UNP_PCB_LOCK(unp);
if ((so = unp->unp_socket) != NULL)
so->so_error =
so->so_proto->pr_type == SOCK_DGRAM ? ECONNRESET : EPIPE;
if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) {
/* Last reference dropped in unp_disconnect(). */
unp_pcb_rele_notlast(unp);
unp_disconnect(unp, unp2);
} else if (!unp_pcb_rele(unp)) {
UNP_PCB_UNLOCK(unp);
}
}
static void
unp_freerights(struct filedescent **fdep, int fdcount)
{
struct file *fp;
int i;
KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
for (i = 0; i < fdcount; i++) {
fp = fdep[i]->fde_file;
filecaps_free(&fdep[i]->fde_caps);
unp_discard(fp);
}
free(fdep[0], M_FILECAPS);
}
static bool
restrict_rights(struct file *fp, struct thread *td)
{
struct prison *prison1, *prison2;
prison1 = fp->f_cred->cr_prison;
prison2 = td->td_ucred->cr_prison;
return (prison1 != prison2 && prison1->pr_root != prison2->pr_root &&
prison2 != &prison0);
}
static int
unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
{
struct thread *td = curthread; /* XXX */
struct cmsghdr *cm = mtod(control, struct cmsghdr *);
int *fdp;
struct filedesc *fdesc = td->td_proc->p_fd;
struct filedescent **fdep;
void *data;
socklen_t clen = control->m_len, datalen;
int error, fdflags, newfds;
u_int newlen;
UNP_LINK_UNLOCK_ASSERT();
fdflags = ((flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0) |
((flags & MSG_CMSG_CLOFORK) ? O_CLOFORK : 0);
error = 0;
if (controlp != NULL) /* controlp == NULL => free control messages */
*controlp = NULL;
while (cm != NULL) {
MPASS(clen >= sizeof(*cm) && clen >= cm->cmsg_len);
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
if (cm->cmsg_level == SOL_SOCKET
&& cm->cmsg_type == SCM_RIGHTS) {
newfds = datalen / sizeof(*fdep);
if (newfds == 0)
goto next;
fdep = data;
/* If we're not outputting the descriptors free them. */
if (error || controlp == NULL) {
unp_freerights(fdep, newfds);
goto next;
}
FILEDESC_XLOCK(fdesc);
/*
* Now change each pointer to an fd in the global
* table to an integer that is the index to the local
* fd table entry that we set up to point to the
* global one we are transferring.
*/
newlen = newfds * sizeof(int);
*controlp = sbcreatecontrol(NULL, newlen,
SCM_RIGHTS, SOL_SOCKET, M_WAITOK);
fdp = (int *)
CMSG_DATA(mtod(*controlp, struct cmsghdr *));
if ((error = fdallocn(td, 0, fdp, newfds))) {
FILEDESC_XUNLOCK(fdesc);
unp_freerights(fdep, newfds);
m_freem(*controlp);
*controlp = NULL;
goto next;
}
for (int i = 0; i < newfds; i++, fdp++) {
struct file *fp;
fp = fdep[i]->fde_file;
_finstall(fdesc, fp, *fdp, fdflags |
(restrict_rights(fp, td) ?
O_RESOLVE_BENEATH : 0), &fdep[i]->fde_caps);
unp_externalize_fp(fp);
}
/*
* The new type indicates that the mbuf data refers to
* kernel resources that may need to be released before
* the mbuf is freed.
*/
m_chtype(*controlp, MT_EXTCONTROL);
FILEDESC_XUNLOCK(fdesc);
free(fdep[0], M_FILECAPS);
} else {
/* We can just copy anything else across. */
if (error || controlp == NULL)
goto next;
*controlp = sbcreatecontrol(NULL, datalen,
cm->cmsg_type, cm->cmsg_level, M_WAITOK);
bcopy(data,
CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
datalen);
}
controlp = &(*controlp)->m_next;
next:
if (CMSG_SPACE(datalen) < clen) {
clen -= CMSG_SPACE(datalen);
cm = (struct cmsghdr *)
((caddr_t)cm + CMSG_SPACE(datalen));
} else {
clen = 0;
cm = NULL;
}
}
return (error);
}
static void
unp_zone_change(void *tag)
{
uma_zone_set_max(unp_zone, maxsockets);
}
#ifdef INVARIANTS
static void
unp_zdtor(void *mem, int size __unused, void *arg __unused)
{
struct unpcb *unp;
unp = mem;
KASSERT(LIST_EMPTY(&unp->unp_refs),
("%s: unpcb %p has lingering refs", __func__, unp));
KASSERT(unp->unp_socket == NULL,
("%s: unpcb %p has socket backpointer", __func__, unp));
KASSERT(unp->unp_vnode == NULL,
("%s: unpcb %p has vnode references", __func__, unp));
KASSERT(unp->unp_conn == NULL,
("%s: unpcb %p is still connected", __func__, unp));
KASSERT(unp->unp_addr == NULL,
("%s: unpcb %p has leaked addr", __func__, unp));
}
#endif
static void
unp_init(void *arg __unused)
{
uma_dtor dtor;
#ifdef INVARIANTS
dtor = unp_zdtor;
#else
dtor = NULL;
#endif
unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor,
NULL, NULL, UMA_ALIGN_CACHE, 0);
uma_zone_set_max(unp_zone, maxsockets);
uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
NULL, EVENTHANDLER_PRI_ANY);
LIST_INIT(&unp_dhead);
LIST_INIT(&unp_shead);
LIST_INIT(&unp_sphead);
SLIST_INIT(&unp_defers);
TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
UNP_LINK_LOCK_INIT();
UNP_DEFERRED_LOCK_INIT();
unp_vp_mtxpool = mtx_pool_create("unp vp mtxpool", 32, MTX_DEF);
}
SYSINIT(unp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_SECOND, unp_init, NULL);
static void
unp_internalize_cleanup_rights(struct mbuf *control)
{
struct cmsghdr *cp;
struct mbuf *m;
void *data;
socklen_t datalen;
for (m = control; m != NULL; m = m->m_next) {
cp = mtod(m, struct cmsghdr *);
if (cp->cmsg_level != SOL_SOCKET ||
cp->cmsg_type != SCM_RIGHTS)
continue;
data = CMSG_DATA(cp);
datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data;
unp_freerights(data, datalen / sizeof(struct filedesc *));
}
}
static int
unp_internalize(struct mbuf *control, struct mchain *mc, struct thread *td)
{
struct proc *p;
struct filedesc *fdesc;
struct bintime *bt;
struct cmsghdr *cm;
struct cmsgcred *cmcred;
struct mbuf *m;
struct filedescent *fde, **fdep, *fdev;
struct file *fp;
struct timeval *tv;
struct timespec *ts;
void *data;
socklen_t clen, datalen;
int i, j, error, *fdp, oldfds;
u_int newlen;
MPASS(control->m_next == NULL); /* COMPAT_OLDSOCK may violate */
UNP_LINK_UNLOCK_ASSERT();
p = td->td_proc;
fdesc = p->p_fd;
error = 0;
*mc = MCHAIN_INITIALIZER(mc);
for (clen = control->m_len, cm = mtod(control, struct cmsghdr *),
data = CMSG_DATA(cm);
clen >= sizeof(*cm) && cm->cmsg_level == SOL_SOCKET &&
clen >= cm->cmsg_len && cm->cmsg_len >= sizeof(*cm) &&
(char *)cm + cm->cmsg_len >= (char *)data;
clen -= min(CMSG_SPACE(datalen), clen),
cm = (struct cmsghdr *) ((char *)cm + CMSG_SPACE(datalen)),
data = CMSG_DATA(cm)) {
datalen = (char *)cm + cm->cmsg_len - (char *)data;
switch (cm->cmsg_type) {
case SCM_CREDS:
m = sbcreatecontrol(NULL, sizeof(*cmcred), SCM_CREDS,
SOL_SOCKET, M_WAITOK);
cmcred = (struct cmsgcred *)
CMSG_DATA(mtod(m, struct cmsghdr *));
cmcred->cmcred_pid = p->p_pid;
cmcred->cmcred_uid = td->td_ucred->cr_ruid;
cmcred->cmcred_gid = td->td_ucred->cr_rgid;
cmcred->cmcred_euid = td->td_ucred->cr_uid;
_Static_assert(CMGROUP_MAX >= 1,
"Room needed for the effective GID.");
cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups + 1,
CMGROUP_MAX);
cmcred->cmcred_groups[0] = td->td_ucred->cr_gid;
for (i = 1; i < cmcred->cmcred_ngroups; i++)
cmcred->cmcred_groups[i] =
td->td_ucred->cr_groups[i - 1];
break;
case SCM_RIGHTS:
oldfds = datalen / sizeof (int);
if (oldfds == 0)
continue;
/* On some machines sizeof pointer is bigger than
* sizeof int, so we need to check if data fits into
* single mbuf. We could allocate several mbufs, and
* unp_externalize() should even properly handle that.
* But it is not worth to complicate the code for an
* insane scenario of passing over 200 file descriptors
* at once.
*/
newlen = oldfds * sizeof(fdep[0]);
if (CMSG_SPACE(newlen) > MCLBYTES) {
error = EMSGSIZE;
goto out;
}
/*
* Check that all the FDs passed in refer to legal
* files. If not, reject the entire operation.
*/
fdp = data;
FILEDESC_SLOCK(fdesc);
for (i = 0; i < oldfds; i++, fdp++) {
fp = fget_noref(fdesc, *fdp);
if (fp == NULL) {
FILEDESC_SUNLOCK(fdesc);
error = EBADF;
goto out;
}
if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
FILEDESC_SUNLOCK(fdesc);
error = EOPNOTSUPP;
goto out;
}
}
/*
* Now replace the integer FDs with pointers to the
* file structure and capability rights.
*/
m = sbcreatecontrol(NULL, newlen, SCM_RIGHTS,
SOL_SOCKET, M_WAITOK);
fdp = data;
for (i = 0; i < oldfds; i++, fdp++) {
if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) {
fdp = data;
for (j = 0; j < i; j++, fdp++) {
fdrop(fdesc->fd_ofiles[*fdp].
fde_file, td);
}
FILEDESC_SUNLOCK(fdesc);
error = EBADF;
goto out;
}
}
fdp = data;
fdep = (struct filedescent **)
CMSG_DATA(mtod(m, struct cmsghdr *));
fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
M_WAITOK);
for (i = 0; i < oldfds; i++, fdev++, fdp++) {
fde = &fdesc->fd_ofiles[*fdp];
fdep[i] = fdev;
fdep[i]->fde_file = fde->fde_file;
filecaps_copy(&fde->fde_caps,
&fdep[i]->fde_caps, true);
unp_internalize_fp(fdep[i]->fde_file);
}
FILEDESC_SUNLOCK(fdesc);
break;
case SCM_TIMESTAMP:
m = sbcreatecontrol(NULL, sizeof(*tv), SCM_TIMESTAMP,
SOL_SOCKET, M_WAITOK);
tv = (struct timeval *)
CMSG_DATA(mtod(m, struct cmsghdr *));
microtime(tv);
break;
case SCM_BINTIME:
m = sbcreatecontrol(NULL, sizeof(*bt), SCM_BINTIME,
SOL_SOCKET, M_WAITOK);
bt = (struct bintime *)
CMSG_DATA(mtod(m, struct cmsghdr *));
bintime(bt);
break;
case SCM_REALTIME:
m = sbcreatecontrol(NULL, sizeof(*ts), SCM_REALTIME,
SOL_SOCKET, M_WAITOK);
ts = (struct timespec *)
CMSG_DATA(mtod(m, struct cmsghdr *));
nanotime(ts);
break;
case SCM_MONOTONIC:
m = sbcreatecontrol(NULL, sizeof(*ts), SCM_MONOTONIC,
SOL_SOCKET, M_WAITOK);
ts = (struct timespec *)
CMSG_DATA(mtod(m, struct cmsghdr *));
nanouptime(ts);
break;
default:
error = EINVAL;
goto out;
}
mc_append(mc, m);
}
if (clen > 0)
error = EINVAL;
out:
if (error != 0)
unp_internalize_cleanup_rights(mc_first(mc));
m_freem(control);
return (error);
}
static void
unp_addsockcred(struct thread *td, struct mchain *mc, int mode)
{
struct mbuf *m, *n, *n_prev;
const struct cmsghdr *cm;
int ngroups, i, cmsgtype;
size_t ctrlsz;
ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
if (mode & UNP_WANTCRED_ALWAYS) {
ctrlsz = SOCKCRED2SIZE(ngroups);
cmsgtype = SCM_CREDS2;
} else {
ctrlsz = SOCKCREDSIZE(ngroups);
cmsgtype = SCM_CREDS;
}
/* XXXGL: uipc_sosend_*() need to be improved so that we can M_WAITOK */
m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET, M_NOWAIT);
if (m == NULL)
return;
MPASS((m->m_flags & M_EXT) == 0 && m->m_next == NULL);
if (mode & UNP_WANTCRED_ALWAYS) {
struct sockcred2 *sc;
sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *));
sc->sc_version = 0;
sc->sc_pid = td->td_proc->p_pid;
sc->sc_uid = td->td_ucred->cr_ruid;
sc->sc_euid = td->td_ucred->cr_uid;
sc->sc_gid = td->td_ucred->cr_rgid;
sc->sc_egid = td->td_ucred->cr_gid;
sc->sc_ngroups = ngroups;
for (i = 0; i < sc->sc_ngroups; i++)
sc->sc_groups[i] = td->td_ucred->cr_groups[i];
} else {
struct sockcred *sc;
sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *));
sc->sc_uid = td->td_ucred->cr_ruid;
sc->sc_euid = td->td_ucred->cr_uid;
sc->sc_gid = td->td_ucred->cr_rgid;
sc->sc_egid = td->td_ucred->cr_gid;
sc->sc_ngroups = ngroups;
for (i = 0; i < sc->sc_ngroups; i++)
sc->sc_groups[i] = td->td_ucred->cr_groups[i];
}
/*
* Unlink SCM_CREDS control messages (struct cmsgcred), since just
* created SCM_CREDS control message (struct sockcred) has another
* format.
*/
if (!STAILQ_EMPTY(&mc->mc_q) && cmsgtype == SCM_CREDS)
STAILQ_FOREACH_SAFE(n, &mc->mc_q, m_stailq, n_prev) {
cm = mtod(n, struct cmsghdr *);
if (cm->cmsg_level == SOL_SOCKET &&
cm->cmsg_type == SCM_CREDS) {
mc_remove(mc, n);
m_free(n);
}
}
/* Prepend it to the head. */
mc_prepend(mc, m);
}
static struct unpcb *
fptounp(struct file *fp)
{
struct socket *so;
if (fp->f_type != DTYPE_SOCKET)
return (NULL);
if ((so = fp->f_data) == NULL)
return (NULL);
if (so->so_proto->pr_domain != &localdomain)
return (NULL);
return sotounpcb(so);
}
static void
unp_discard(struct file *fp)
{
struct unp_defer *dr;
if (unp_externalize_fp(fp)) {
dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
dr->ud_fp = fp;
UNP_DEFERRED_LOCK();
SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
UNP_DEFERRED_UNLOCK();
atomic_add_int(&unp_defers_count, 1);
taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
} else
closef_nothread(fp);
}
static void
unp_process_defers(void *arg __unused, int pending)
{
struct unp_defer *dr;
SLIST_HEAD(, unp_defer) drl;
int count;
SLIST_INIT(&drl);
for (;;) {
UNP_DEFERRED_LOCK();
if (SLIST_FIRST(&unp_defers) == NULL) {
UNP_DEFERRED_UNLOCK();
break;
}
SLIST_SWAP(&unp_defers, &drl, unp_defer);
UNP_DEFERRED_UNLOCK();
count = 0;
while ((dr = SLIST_FIRST(&drl)) != NULL) {
SLIST_REMOVE_HEAD(&drl, ud_link);
closef_nothread(dr->ud_fp);
free(dr, M_TEMP);
count++;
}
atomic_add_int(&unp_defers_count, -count);
}
}
static void
unp_internalize_fp(struct file *fp)
{
struct unpcb *unp;
UNP_LINK_WLOCK();
if ((unp = fptounp(fp)) != NULL) {
unp->unp_file = fp;
unp->unp_msgcount++;
}
unp_rights++;
UNP_LINK_WUNLOCK();
}
static int
unp_externalize_fp(struct file *fp)
{
struct unpcb *unp;
int ret;
UNP_LINK_WLOCK();
if ((unp = fptounp(fp)) != NULL) {
unp->unp_msgcount--;
ret = 1;
} else
ret = 0;
unp_rights--;
UNP_LINK_WUNLOCK();
return (ret);
}
/*
* unp_defer indicates whether additional work has been defered for a future
* pass through unp_gc(). It is thread local and does not require explicit
* synchronization.
*/
static int unp_marked;
static void
unp_remove_dead_ref(struct filedescent **fdep, int fdcount)
{
struct unpcb *unp;
struct file *fp;
int i;
/*
* This function can only be called from the gc task.
*/
KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0,
("%s: not on gc callout", __func__));
UNP_LINK_LOCK_ASSERT();
for (i = 0; i < fdcount; i++) {
fp = fdep[i]->fde_file;
if ((unp = fptounp(fp)) == NULL)
continue;
if ((unp->unp_gcflag & UNPGC_DEAD) == 0)
continue;
unp->unp_gcrefs--;
}
}
static void
unp_restore_undead_ref(struct filedescent **fdep, int fdcount)
{
struct unpcb *unp;
struct file *fp;
int i;
/*
* This function can only be called from the gc task.
*/
KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0,
("%s: not on gc callout", __func__));
UNP_LINK_LOCK_ASSERT();
for (i = 0; i < fdcount; i++) {
fp = fdep[i]->fde_file;
if ((unp = fptounp(fp)) == NULL)
continue;
if ((unp->unp_gcflag & UNPGC_DEAD) == 0)
continue;
unp->unp_gcrefs++;
unp_marked++;
}
}
static void
unp_scan_socket(struct socket *so, void (*op)(struct filedescent **, int))
{
struct sockbuf *sb;
SOCK_LOCK_ASSERT(so);
if (sotounpcb(so)->unp_gcflag & UNPGC_IGNORE_RIGHTS)
return;
SOCK_RECVBUF_LOCK(so);
switch (so->so_type) {
case SOCK_DGRAM:
unp_scan(STAILQ_FIRST(&so->so_rcv.uxdg_mb), op);
unp_scan(so->so_rcv.uxdg_peeked, op);
TAILQ_FOREACH(sb, &so->so_rcv.uxdg_conns, uxdg_clist)
unp_scan(STAILQ_FIRST(&sb->uxdg_mb), op);
break;
case SOCK_STREAM:
case SOCK_SEQPACKET:
unp_scan(STAILQ_FIRST(&so->so_rcv.uxst_mbq), op);
break;
}
SOCK_RECVBUF_UNLOCK(so);
}
static void
unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int))
{
struct socket *so, *soa;
so = unp->unp_socket;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
/*
* Mark all sockets in our accept queue.
*/
TAILQ_FOREACH(soa, &so->sol_comp, so_list)
unp_scan_socket(soa, op);
} else {
/*
* Mark all sockets we reference with RIGHTS.
*/
unp_scan_socket(so, op);
}
SOCK_UNLOCK(so);
}
static int unp_recycled;
SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
"Number of unreachable sockets claimed by the garbage collector.");
static int unp_taskcount;
SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
"Number of times the garbage collector has run.");
SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0,
"Number of active local sockets.");
static void
unp_gc(__unused void *arg, int pending)
{
struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
NULL };
struct unp_head **head;
struct unp_head unp_deadhead; /* List of potentially-dead sockets. */
struct file *f, **unref;
struct unpcb *unp, *unptmp;
int i, total, unp_unreachable;
LIST_INIT(&unp_deadhead);
unp_taskcount++;
UNP_LINK_RLOCK();
/*
* First determine which sockets may be in cycles.
*/
unp_unreachable = 0;
for (head = heads; *head != NULL; head++)
LIST_FOREACH(unp, *head, unp_link) {
KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0,
("%s: unp %p has unexpected gc flags 0x%x",
__func__, unp, (unsigned int)unp->unp_gcflag));
f = unp->unp_file;
/*
* Check for an unreachable socket potentially in a
* cycle. It must be in a queue as indicated by
* msgcount, and this must equal the file reference
* count. Note that when msgcount is 0 the file is
* NULL.
*/
if (f != NULL && unp->unp_msgcount != 0 &&
refcount_load(&f->f_count) == unp->unp_msgcount) {
LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead);
unp->unp_gcflag |= UNPGC_DEAD;
unp->unp_gcrefs = unp->unp_msgcount;
unp_unreachable++;
}
}
/*
* Scan all sockets previously marked as potentially being in a cycle
* and remove the references each socket holds on any UNPGC_DEAD
* sockets in its queue. After this step, all remaining references on
* sockets marked UNPGC_DEAD should not be part of any cycle.
*/
LIST_FOREACH(unp, &unp_deadhead, unp_dead)
unp_gc_scan(unp, unp_remove_dead_ref);
/*
* If a socket still has a non-negative refcount, it cannot be in a
* cycle. In this case increment refcount of all children iteratively.
* Stop the scan once we do a complete loop without discovering
* a new reachable socket.
*/
do {
unp_marked = 0;
LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp)
if (unp->unp_gcrefs > 0) {
unp->unp_gcflag &= ~UNPGC_DEAD;
LIST_REMOVE(unp, unp_dead);
KASSERT(unp_unreachable > 0,
("%s: unp_unreachable underflow.",
__func__));
unp_unreachable--;
unp_gc_scan(unp, unp_restore_undead_ref);
}
} while (unp_marked);
UNP_LINK_RUNLOCK();
if (unp_unreachable == 0)
return;
/*
* Allocate space for a local array of dead unpcbs.
* TODO: can this path be simplified by instead using the local
* dead list at unp_deadhead, after taking out references
* on the file object and/or unpcb and dropping the link lock?
*/
unref = malloc(unp_unreachable * sizeof(struct file *),
M_TEMP, M_WAITOK);
/*
* Iterate looking for sockets which have been specifically marked
* as unreachable and store them locally.
*/
UNP_LINK_RLOCK();
total = 0;
LIST_FOREACH(unp, &unp_deadhead, unp_dead) {
KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0,
("%s: unp %p not marked UNPGC_DEAD", __func__, unp));
unp->unp_gcflag &= ~UNPGC_DEAD;
f = unp->unp_file;
if (unp->unp_msgcount == 0 || f == NULL ||
refcount_load(&f->f_count) != unp->unp_msgcount ||
!fhold(f))
continue;
unref[total++] = f;
KASSERT(total <= unp_unreachable,
("%s: incorrect unreachable count.", __func__));
}
UNP_LINK_RUNLOCK();
/*
* Now flush all sockets, free'ing rights. This will free the
* struct files associated with these sockets but leave each socket
* with one remaining ref.
*/
for (i = 0; i < total; i++) {
struct socket *so;
so = unref[i]->f_data;
if (!SOLISTENING(so)) {
CURVNET_SET(so->so_vnet);
socantrcvmore(so);
unp_dispose(so);
CURVNET_RESTORE();
}
}
/*
* And finally release the sockets so they can be reclaimed.
*/
for (i = 0; i < total; i++)
fdrop(unref[i], NULL);
unp_recycled += total;
free(unref, M_TEMP);
}
/*
* Synchronize against unp_gc, which can trip over data as we are freeing it.
*/
static void
unp_dispose(struct socket *so)
{
struct sockbuf *sb;
struct unpcb *unp;
struct mbuf *m;
int error __diagused;
MPASS(!SOLISTENING(so));
unp = sotounpcb(so);
UNP_LINK_WLOCK();
unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS;
UNP_LINK_WUNLOCK();
/*
* Grab our special mbufs before calling sbrelease().
*/
error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
MPASS(!error);
SOCK_RECVBUF_LOCK(so);
switch (so->so_type) {
case SOCK_DGRAM:
while ((sb = TAILQ_FIRST(&so->so_rcv.uxdg_conns)) != NULL) {
STAILQ_CONCAT(&so->so_rcv.uxdg_mb, &sb->uxdg_mb);
TAILQ_REMOVE(&so->so_rcv.uxdg_conns, sb, uxdg_clist);
/* Note: socket of sb may reconnect. */
sb->uxdg_cc = sb->uxdg_ctl = sb->uxdg_mbcnt = 0;
}
sb = &so->so_rcv;
if (sb->uxdg_peeked != NULL) {
STAILQ_INSERT_HEAD(&sb->uxdg_mb, sb->uxdg_peeked,
m_stailqpkt);
sb->uxdg_peeked = NULL;
}
m = STAILQ_FIRST(&sb->uxdg_mb);
STAILQ_INIT(&sb->uxdg_mb);
break;
case SOCK_STREAM:
case SOCK_SEQPACKET:
sb = &so->so_rcv;
m = STAILQ_FIRST(&sb->uxst_mbq);
STAILQ_INIT(&sb->uxst_mbq);
sb->sb_acc = sb->sb_ccc = sb->sb_ctl = sb->sb_mbcnt = 0;
/*
* Trim M_NOTREADY buffers from the free list. They are
* referenced by the I/O thread.
*/
if (sb->uxst_fnrdy != NULL) {
struct mbuf *n, *prev;
while (m != NULL && m->m_flags & M_NOTREADY)
m = m->m_next;
for (prev = n = m; n != NULL; n = n->m_next) {
if (n->m_flags & M_NOTREADY)
prev->m_next = n->m_next;
else
prev = n;
}
sb->uxst_fnrdy = NULL;
}
break;
}
/*
* Mark sb with SBS_CANTRCVMORE. This is needed to prevent
* uipc_sosend_*() or unp_disconnect() adding more data to the socket.
* We came here either through shutdown(2) or from the final sofree().
* The sofree() case is simple as it guarantees that no more sends will
* happen, however we can race with unp_disconnect() from our peer.
* The shutdown(2) case is more exotic. It would call into
* unp_dispose() only if socket is SS_ISCONNECTED. This is possible if
* we did connect(2) on this socket and we also had it bound with
* bind(2) and receive connections from other sockets. Because
* uipc_shutdown() violates POSIX (see comment there) this applies to
* SOCK_DGRAM as well. For SOCK_DGRAM this SBS_CANTRCVMORE will have
* affect not only on the peer we connect(2)ed to, but also on all of
* the peers who had connect(2)ed to us. Their sends would end up
* with ENOBUFS.
*/
sb->sb_state |= SBS_CANTRCVMORE;
(void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
RLIM_INFINITY);
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
if (m != NULL) {
unp_scan(m, unp_freerights);
m_freemp(m);
}
}
static void
unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
{
struct mbuf *m;
struct cmsghdr *cm;
void *data;
socklen_t clen, datalen;
while (m0 != NULL) {
for (m = m0; m; m = m->m_next) {
if (m->m_type != MT_CONTROL)
continue;
cm = mtod(m, struct cmsghdr *);
clen = m->m_len;
while (cm != NULL) {
if (sizeof(*cm) > clen || cm->cmsg_len > clen)
break;
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len
- (caddr_t)data;
if (cm->cmsg_level == SOL_SOCKET &&
cm->cmsg_type == SCM_RIGHTS) {
(*op)(data, datalen /
sizeof(struct filedescent *));
}
if (CMSG_SPACE(datalen) < clen) {
clen -= CMSG_SPACE(datalen);
cm = (struct cmsghdr *)
((caddr_t)cm + CMSG_SPACE(datalen));
} else {
clen = 0;
cm = NULL;
}
}
}
m0 = m0->m_nextpkt;
}
}
/*
* Definitions of protocols supported in the LOCAL domain.
*/
static struct protosw streamproto = {
.pr_type = SOCK_STREAM,
.pr_flags = PR_CONNREQUIRED | PR_CAPATTACH | PR_SOCKBUF,
.pr_ctloutput = &uipc_ctloutput,
.pr_abort = uipc_abort,
.pr_accept = uipc_peeraddr,
.pr_attach = uipc_attach,
.pr_bind = uipc_bind,
.pr_bindat = uipc_bindat,
.pr_connect = uipc_connect,
.pr_connectat = uipc_connectat,
.pr_connect2 = uipc_connect2,
.pr_detach = uipc_detach,
.pr_disconnect = uipc_disconnect,
.pr_fdclose = uipc_fdclose,
.pr_listen = uipc_listen,
.pr_peeraddr = uipc_peeraddr,
.pr_send = uipc_sendfile,
.pr_sendfile_wait = uipc_sendfile_wait,
.pr_ready = uipc_ready,
.pr_sense = uipc_sense,
.pr_shutdown = uipc_shutdown,
.pr_sockaddr = uipc_sockaddr,
.pr_sosend = uipc_sosend_stream_or_seqpacket,
.pr_soreceive = uipc_soreceive_stream_or_seqpacket,
.pr_sopoll = uipc_sopoll_stream_or_seqpacket,
.pr_kqfilter = uipc_kqfilter_stream_or_seqpacket,
.pr_close = uipc_close,
.pr_chmod = uipc_chmod,
};
static struct protosw dgramproto = {
.pr_type = SOCK_DGRAM,
.pr_flags = PR_ATOMIC | PR_ADDR | PR_CAPATTACH | PR_SOCKBUF,
.pr_ctloutput = &uipc_ctloutput,
.pr_abort = uipc_abort,
.pr_accept = uipc_peeraddr,
.pr_attach = uipc_attach,
.pr_bind = uipc_bind,
.pr_bindat = uipc_bindat,
.pr_connect = uipc_connect,
.pr_connectat = uipc_connectat,
.pr_connect2 = uipc_connect2,
.pr_detach = uipc_detach,
.pr_disconnect = uipc_disconnect,
.pr_fdclose = uipc_fdclose,
.pr_peeraddr = uipc_peeraddr,
.pr_sosend = uipc_sosend_dgram,
.pr_sense = uipc_sense,
.pr_shutdown = uipc_shutdown,
.pr_sockaddr = uipc_sockaddr,
.pr_soreceive = uipc_soreceive_dgram,
.pr_close = uipc_close,
.pr_chmod = uipc_chmod,
};
static struct protosw seqpacketproto = {
.pr_type = SOCK_SEQPACKET,
.pr_flags = PR_CONNREQUIRED | PR_CAPATTACH | PR_SOCKBUF,
.pr_ctloutput = &uipc_ctloutput,
.pr_abort = uipc_abort,
.pr_accept = uipc_peeraddr,
.pr_attach = uipc_attach,
.pr_bind = uipc_bind,
.pr_bindat = uipc_bindat,
.pr_connect = uipc_connect,
.pr_connectat = uipc_connectat,
.pr_connect2 = uipc_connect2,
.pr_detach = uipc_detach,
.pr_disconnect = uipc_disconnect,
.pr_fdclose = uipc_fdclose,
.pr_listen = uipc_listen,
.pr_peeraddr = uipc_peeraddr,
.pr_sense = uipc_sense,
.pr_shutdown = uipc_shutdown,
.pr_sockaddr = uipc_sockaddr,
.pr_sosend = uipc_sosend_stream_or_seqpacket,
.pr_soreceive = uipc_soreceive_stream_or_seqpacket,
.pr_sopoll = uipc_sopoll_stream_or_seqpacket,
.pr_kqfilter = uipc_kqfilter_stream_or_seqpacket,
.pr_close = uipc_close,
.pr_chmod = uipc_chmod,
};
static struct domain localdomain = {
.dom_family = AF_LOCAL,
.dom_name = "local",
.dom_nprotosw = 3,
.dom_protosw = {
&streamproto,
&dgramproto,
&seqpacketproto,
}
};
DOMAIN_SET(local);
/*
* A helper function called by VFS before socket-type vnode reclamation.
* For an active vnode it clears unp_vnode pointer and decrements unp_vnode
* use count.
*/
void
vfs_unp_reclaim(struct vnode *vp)
{
struct unpcb *unp;
int active;
struct mtx *vplock;
ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
KASSERT(vp->v_type == VSOCK,
("vfs_unp_reclaim: vp->v_type != VSOCK"));
active = 0;
vplock = mtx_pool_find(unp_vp_mtxpool, vp);
mtx_lock(vplock);
VOP_UNP_CONNECT(vp, &unp);
if (unp == NULL)
goto done;
UNP_PCB_LOCK(unp);
if (unp->unp_vnode == vp) {
VOP_UNP_DETACH(vp);
unp->unp_vnode = NULL;
active = 1;
}
UNP_PCB_UNLOCK(unp);
done:
mtx_unlock(vplock);
if (active)
vunref(vp);
}
#ifdef DDB
static void
db_print_indent(int indent)
{
int i;
for (i = 0; i < indent; i++)
db_printf(" ");
}
static void
db_print_unpflags(int unp_flags)
{
int comma;
comma = 0;
if (unp_flags & UNP_HAVEPC) {
db_printf("%sUNP_HAVEPC", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_WANTCRED_ALWAYS) {
db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_WANTCRED_ONESHOT) {
db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_CONNECTING) {
db_printf("%sUNP_CONNECTING", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_BINDING) {
db_printf("%sUNP_BINDING", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_xucred(int indent, struct xucred *xu)
{
int comma, i;
db_print_indent(indent);
db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n",
xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups);
db_print_indent(indent);
db_printf("cr_groups: ");
comma = 0;
for (i = 0; i < xu->cr_ngroups; i++) {
db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
comma = 1;
}
db_printf("\n");
}
static void
db_print_unprefs(int indent, struct unp_head *uh)
{
struct unpcb *unp;
int counter;
counter = 0;
LIST_FOREACH(unp, uh, unp_reflink) {
if (counter % 4 == 0)
db_print_indent(indent);
db_printf("%p ", unp);
if (counter % 4 == 3)
db_printf("\n");
counter++;
}
if (counter != 0 && counter % 4 != 0)
db_printf("\n");
}
DB_SHOW_COMMAND(unpcb, db_show_unpcb)
{
struct unpcb *unp;
if (!have_addr) {
db_printf("usage: show unpcb <addr>\n");
return;
}
unp = (struct unpcb *)addr;
db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket,
unp->unp_vnode);
db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino,
unp->unp_conn);
db_printf("unp_refs:\n");
db_print_unprefs(2, &unp->unp_refs);
/* XXXRW: Would be nice to print the full address, if any. */
db_printf("unp_addr: %p\n", unp->unp_addr);
db_printf("unp_gencnt: %llu\n",
(unsigned long long)unp->unp_gencnt);
db_printf("unp_flags: %x (", unp->unp_flags);
db_print_unpflags(unp->unp_flags);
db_printf(")\n");
db_printf("unp_peercred:\n");
db_print_xucred(2, &unp->unp_peercred);
db_printf("unp_refcount: %u\n", unp->unp_refcount);
}
#endif
diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c
index 8c58be63cd5a..4b501b221bcb 100644
--- a/sys/netinet/tcp_syncache.c
+++ b/sys/netinet/tcp_syncache.c
@@ -1,2616 +1,2625 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2001 McAfee, Inc.
* Copyright (c) 2006,2013 Andre Oppermann, Internet Business Solutions AG
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Jonathan Lemon
* and McAfee Research, the Security Research Division of McAfee, Inc. under
* DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program. [2001 McAfee, Inc.]
*
* 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.
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/hash.h>
#include <sys/refcount.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h> /* for proc0 declaration */
#include <sys/random.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/syslog.h>
#include <sys/ucred.h>
#include <sys/md5.h>
#include <crypto/siphash/siphash.h>
#include <vm/uma.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_var.h>
#include <netinet/in_pcb.h>
#include <netinet/in_rss.h>
#include <netinet/ip_var.h>
#include <netinet/ip_options.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/in6_rss.h>
#endif
#include <netinet/tcp.h>
#include <netinet/tcp_fastopen.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_syncache.h>
#include <netinet/tcp_ecn.h>
#ifdef TCP_BLACKBOX
#include <netinet/tcp_log_buf.h>
#endif
#ifdef TCP_OFFLOAD
#include <netinet/toecore.h>
#endif
#include <netinet/udp.h>
#include <netipsec/ipsec_support.h>
#include <machine/in_cksum.h>
#include <security/mac/mac_framework.h>
VNET_DEFINE_STATIC(bool, tcp_syncookies) = true;
#define V_tcp_syncookies VNET(tcp_syncookies)
SYSCTL_BOOL(_net_inet_tcp, OID_AUTO, syncookies, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(tcp_syncookies), 0,
"Use TCP SYN cookies if the syncache overflows");
VNET_DEFINE_STATIC(bool, tcp_syncookiesonly) = false;
#define V_tcp_syncookiesonly VNET(tcp_syncookiesonly)
SYSCTL_BOOL(_net_inet_tcp, OID_AUTO, syncookies_only, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(tcp_syncookiesonly), 0,
"Use only TCP SYN cookies");
#ifdef TCP_OFFLOAD
#define ADDED_BY_TOE(sc) ((sc)->sc_tod != NULL)
#endif
static void syncache_drop(struct syncache *, struct syncache_head *);
static void syncache_free(struct syncache *);
static void syncache_insert(struct syncache *, struct syncache_head *);
static int syncache_respond(struct syncache *, int);
static void syncache_send_challenge_ack(struct syncache *);
static struct socket *syncache_socket(struct syncache *, struct socket *,
struct mbuf *m);
static void syncache_timeout(struct syncache *sc, struct syncache_head *sch,
int docallout);
static void syncache_timer(void *);
static uint32_t syncookie_mac(struct in_conninfo *, tcp_seq, uint8_t,
uint8_t *, uintptr_t);
static tcp_seq syncookie_generate(struct syncache_head *, struct syncache *);
static bool syncookie_expand(struct in_conninfo *,
const struct syncache_head *, struct syncache *,
struct tcphdr *, struct tcpopt *, struct socket *,
uint16_t);
static void syncache_pause(struct in_conninfo *);
static void syncache_unpause(void *);
static void syncookie_reseed(void *);
#ifdef INVARIANTS
static void syncookie_cmp(struct in_conninfo *,
const struct syncache_head *, struct syncache *,
struct tcphdr *, struct tcpopt *, struct socket *,
uint16_t);
#endif
/*
* Transmit the SYN,ACK fewer times than TCP_MAXRXTSHIFT specifies.
* 3 retransmits corresponds to a timeout with default values of
* tcp_rexmit_initial * ( 1 +
* tcp_backoff[1] +
* tcp_backoff[2] +
* tcp_backoff[3]) + 3 * tcp_rexmit_slop,
* 1000 ms * (1 + 2 + 4 + 8) + 3 * 200 ms = 15600 ms,
* the odds are that the user has given up attempting to connect by then.
*/
#define SYNCACHE_MAXREXMTS 3
/* Arbitrary values */
#define TCP_SYNCACHE_HASHSIZE 512
#define TCP_SYNCACHE_BUCKETLIMIT 30
VNET_DEFINE_STATIC(struct tcp_syncache, tcp_syncache);
#define V_tcp_syncache VNET(tcp_syncache)
static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, syncache,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TCP SYN cache");
SYSCTL_UINT(_net_inet_tcp_syncache, OID_AUTO, bucketlimit, CTLFLAG_VNET | CTLFLAG_RDTUN,
&VNET_NAME(tcp_syncache.bucket_limit), 0,
"Per-bucket hash limit for syncache");
SYSCTL_UINT(_net_inet_tcp_syncache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN,
&VNET_NAME(tcp_syncache.cache_limit), 0,
"Overall entry limit for syncache");
SYSCTL_UMA_CUR(_net_inet_tcp_syncache, OID_AUTO, count, CTLFLAG_VNET,
&VNET_NAME(tcp_syncache.zone), "Current number of entries in syncache");
SYSCTL_UINT(_net_inet_tcp_syncache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN,
&VNET_NAME(tcp_syncache.hashsize), 0,
"Size of TCP syncache hashtable");
SYSCTL_BOOL(_net_inet_tcp_syncache, OID_AUTO, see_other, CTLFLAG_VNET |
CTLFLAG_RW, &VNET_NAME(tcp_syncache.see_other), 0,
"All syncache(4) entries are visible, ignoring UID/GID, jail(2) "
"and mac(4) checks");
static int
sysctl_net_inet_tcp_syncache_rexmtlimit_check(SYSCTL_HANDLER_ARGS)
{
int error;
u_int new;
new = V_tcp_syncache.rexmt_limit;
error = sysctl_handle_int(oidp, &new, 0, req);
if ((error == 0) && (req->newptr != NULL)) {
if (new > TCP_MAXRXTSHIFT)
error = EINVAL;
else
V_tcp_syncache.rexmt_limit = new;
}
return (error);
}
SYSCTL_PROC(_net_inet_tcp_syncache, OID_AUTO, rexmtlimit,
CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
&VNET_NAME(tcp_syncache.rexmt_limit), 0,
sysctl_net_inet_tcp_syncache_rexmtlimit_check, "IU",
"Limit on SYN/ACK retransmissions");
VNET_DEFINE(int, tcp_sc_rst_sock_fail) = 1;
SYSCTL_INT(_net_inet_tcp_syncache, OID_AUTO, rst_on_sock_fail,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_sc_rst_sock_fail), 0,
"Send reset on socket allocation failure");
static MALLOC_DEFINE(M_SYNCACHE, "syncache", "TCP syncache");
#define SCH_LOCK(sch) mtx_lock(&(sch)->sch_mtx)
#define SCH_UNLOCK(sch) mtx_unlock(&(sch)->sch_mtx)
#define SCH_LOCK_ASSERT(sch) mtx_assert(&(sch)->sch_mtx, MA_OWNED)
/*
* Requires the syncache entry to be already removed from the bucket list.
*/
static void
syncache_free(struct syncache *sc)
{
if (sc->sc_ipopts)
(void)m_free(sc->sc_ipopts);
if (sc->sc_cred)
crfree(sc->sc_cred);
#ifdef MAC
mac_syncache_destroy(&sc->sc_label);
#endif
uma_zfree(V_tcp_syncache.zone, sc);
}
void
syncache_init(void)
{
int i;
V_tcp_syncache.hashsize = TCP_SYNCACHE_HASHSIZE;
V_tcp_syncache.bucket_limit = TCP_SYNCACHE_BUCKETLIMIT;
V_tcp_syncache.rexmt_limit = SYNCACHE_MAXREXMTS;
V_tcp_syncache.hash_secret = arc4random();
TUNABLE_INT_FETCH("net.inet.tcp.syncache.hashsize",
&V_tcp_syncache.hashsize);
TUNABLE_INT_FETCH("net.inet.tcp.syncache.bucketlimit",
&V_tcp_syncache.bucket_limit);
if (!powerof2(V_tcp_syncache.hashsize) ||
V_tcp_syncache.hashsize == 0) {
printf("WARNING: syncache hash size is not a power of 2.\n");
V_tcp_syncache.hashsize = TCP_SYNCACHE_HASHSIZE;
}
V_tcp_syncache.hashmask = V_tcp_syncache.hashsize - 1;
/* Set limits. */
V_tcp_syncache.cache_limit =
V_tcp_syncache.hashsize * V_tcp_syncache.bucket_limit;
TUNABLE_INT_FETCH("net.inet.tcp.syncache.cachelimit",
&V_tcp_syncache.cache_limit);
/* Allocate the hash table. */
V_tcp_syncache.hashbase = malloc(V_tcp_syncache.hashsize *
sizeof(struct syncache_head), M_SYNCACHE, M_WAITOK | M_ZERO);
#ifdef VIMAGE
V_tcp_syncache.vnet = curvnet;
#endif
/* Initialize the hash buckets. */
for (i = 0; i < V_tcp_syncache.hashsize; i++) {
TAILQ_INIT(&V_tcp_syncache.hashbase[i].sch_bucket);
mtx_init(&V_tcp_syncache.hashbase[i].sch_mtx, "tcp_sc_head",
NULL, MTX_DEF);
callout_init_mtx(&V_tcp_syncache.hashbase[i].sch_timer,
&V_tcp_syncache.hashbase[i].sch_mtx, 0);
V_tcp_syncache.hashbase[i].sch_length = 0;
V_tcp_syncache.hashbase[i].sch_sc = &V_tcp_syncache;
V_tcp_syncache.hashbase[i].sch_last_overflow =
-(SYNCOOKIE_LIFETIME + 1);
}
/* Create the syncache entry zone. */
V_tcp_syncache.zone = uma_zcreate("syncache", sizeof(struct syncache),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
V_tcp_syncache.cache_limit = uma_zone_set_max(V_tcp_syncache.zone,
V_tcp_syncache.cache_limit);
/* Start the SYN cookie reseeder callout. */
callout_init(&V_tcp_syncache.secret.reseed, 1);
arc4rand(V_tcp_syncache.secret.key[0], SYNCOOKIE_SECRET_SIZE, 0);
arc4rand(V_tcp_syncache.secret.key[1], SYNCOOKIE_SECRET_SIZE, 0);
callout_reset(&V_tcp_syncache.secret.reseed, SYNCOOKIE_LIFETIME * hz,
syncookie_reseed, &V_tcp_syncache);
/* Initialize the pause machinery. */
mtx_init(&V_tcp_syncache.pause_mtx, "tcp_sc_pause", NULL, MTX_DEF);
callout_init_mtx(&V_tcp_syncache.pause_co, &V_tcp_syncache.pause_mtx,
0);
V_tcp_syncache.pause_until = time_uptime - TCP_SYNCACHE_PAUSE_TIME;
V_tcp_syncache.pause_backoff = 0;
V_tcp_syncache.paused = false;
}
#ifdef VIMAGE
void
syncache_destroy(void)
{
struct syncache_head *sch;
struct syncache *sc, *nsc;
int i;
/*
* Stop the re-seed timer before freeing resources. No need to
* possibly schedule it another time.
*/
callout_drain(&V_tcp_syncache.secret.reseed);
/* Stop the SYN cache pause callout. */
mtx_lock(&V_tcp_syncache.pause_mtx);
if (callout_stop(&V_tcp_syncache.pause_co) == 0) {
mtx_unlock(&V_tcp_syncache.pause_mtx);
callout_drain(&V_tcp_syncache.pause_co);
} else
mtx_unlock(&V_tcp_syncache.pause_mtx);
/* Cleanup hash buckets: stop timers, free entries, destroy locks. */
for (i = 0; i < V_tcp_syncache.hashsize; i++) {
sch = &V_tcp_syncache.hashbase[i];
callout_drain(&sch->sch_timer);
SCH_LOCK(sch);
TAILQ_FOREACH_SAFE(sc, &sch->sch_bucket, sc_hash, nsc)
syncache_drop(sc, sch);
SCH_UNLOCK(sch);
KASSERT(TAILQ_EMPTY(&sch->sch_bucket),
("%s: sch->sch_bucket not empty", __func__));
KASSERT(sch->sch_length == 0, ("%s: sch->sch_length %d not 0",
__func__, sch->sch_length));
mtx_destroy(&sch->sch_mtx);
}
KASSERT(uma_zone_get_cur(V_tcp_syncache.zone) == 0,
("%s: cache_count not 0", __func__));
/* Free the allocated global resources. */
uma_zdestroy(V_tcp_syncache.zone);
free(V_tcp_syncache.hashbase, M_SYNCACHE);
mtx_destroy(&V_tcp_syncache.pause_mtx);
}
#endif
/*
* Inserts a syncache entry into the specified bucket row.
* Locks and unlocks the syncache_head autonomously.
*/
static void
syncache_insert(struct syncache *sc, struct syncache_head *sch)
{
struct syncache *sc2;
SCH_LOCK(sch);
/*
* Make sure that we don't overflow the per-bucket limit.
* If the bucket is full, toss the oldest element.
*/
if (sch->sch_length >= V_tcp_syncache.bucket_limit) {
KASSERT(!TAILQ_EMPTY(&sch->sch_bucket),
("sch->sch_length incorrect"));
syncache_pause(&sc->sc_inc);
sc2 = TAILQ_LAST(&sch->sch_bucket, sch_head);
sch->sch_last_overflow = time_uptime;
syncache_drop(sc2, sch);
}
/* Put it into the bucket. */
TAILQ_INSERT_HEAD(&sch->sch_bucket, sc, sc_hash);
sch->sch_length++;
#ifdef TCP_OFFLOAD
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
tod->tod_syncache_added(tod, sc->sc_todctx);
}
#endif
/* Reinitialize the bucket row's timer. */
if (sch->sch_length == 1)
sch->sch_nextc = ticks + INT_MAX;
syncache_timeout(sc, sch, 1);
SCH_UNLOCK(sch);
TCPSTATES_INC(TCPS_SYN_RECEIVED);
TCPSTAT_INC(tcps_sc_added);
}
/*
* Remove and free entry from syncache bucket row.
* Expects locked syncache head.
*/
static void
syncache_drop(struct syncache *sc, struct syncache_head *sch)
{
SCH_LOCK_ASSERT(sch);
TCPSTATES_DEC(TCPS_SYN_RECEIVED);
TAILQ_REMOVE(&sch->sch_bucket, sc, sc_hash);
sch->sch_length--;
#ifdef TCP_OFFLOAD
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
tod->tod_syncache_removed(tod, sc->sc_todctx);
}
#endif
syncache_free(sc);
}
/*
* Engage/reengage time on bucket row.
*/
static void
syncache_timeout(struct syncache *sc, struct syncache_head *sch, int docallout)
{
int rexmt;
if (sc->sc_rxmits == 0)
rexmt = tcp_rexmit_initial;
else
TCPT_RANGESET(rexmt,
tcp_rexmit_initial * tcp_backoff[sc->sc_rxmits],
tcp_rexmit_min, tcp_rexmit_max);
sc->sc_rxttime = ticks + rexmt;
sc->sc_rxmits++;
if (TSTMP_LT(sc->sc_rxttime, sch->sch_nextc)) {
sch->sch_nextc = sc->sc_rxttime;
if (docallout)
callout_reset(&sch->sch_timer, sch->sch_nextc - ticks,
syncache_timer, (void *)sch);
}
}
/*
* Walk the timer queues, looking for SYN,ACKs that need to be retransmitted.
* If we have retransmitted an entry the maximum number of times, expire it.
* One separate timer for each bucket row.
*/
static void
syncache_timer(void *xsch)
{
struct syncache_head *sch = (struct syncache_head *)xsch;
struct syncache *sc, *nsc;
struct epoch_tracker et;
int tick = ticks;
char *s;
bool paused;
CURVNET_SET(sch->sch_sc->vnet);
/* NB: syncache_head has already been locked by the callout. */
SCH_LOCK_ASSERT(sch);
/*
* In the following cycle we may remove some entries and/or
* advance some timeouts, so re-initialize the bucket timer.
*/
sch->sch_nextc = tick + INT_MAX;
/*
* If we have paused processing, unconditionally remove
* all syncache entries.
*/
mtx_lock(&V_tcp_syncache.pause_mtx);
paused = V_tcp_syncache.paused;
mtx_unlock(&V_tcp_syncache.pause_mtx);
TAILQ_FOREACH_SAFE(sc, &sch->sch_bucket, sc_hash, nsc) {
if (paused) {
syncache_drop(sc, sch);
continue;
}
/*
* We do not check if the listen socket still exists
* and accept the case where the listen socket may be
* gone by the time we resend the SYN/ACK. We do
* not expect this to happens often. If it does,
* then the RST will be sent by the time the remote
* host does the SYN/ACK->ACK.
*/
if (TSTMP_GT(sc->sc_rxttime, tick)) {
if (TSTMP_LT(sc->sc_rxttime, sch->sch_nextc))
sch->sch_nextc = sc->sc_rxttime;
continue;
}
if (sc->sc_rxmits > V_tcp_ecn_maxretries) {
sc->sc_flags &= ~SCF_ECN_MASK;
}
if (sc->sc_rxmits > V_tcp_syncache.rexmt_limit) {
if ((s = tcp_log_addrs(&sc->sc_inc, NULL, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Retransmits exhausted, "
"giving up and removing syncache entry\n",
s, __func__);
free(s, M_TCPLOG);
}
syncache_drop(sc, sch);
TCPSTAT_INC(tcps_sc_stale);
continue;
}
if ((s = tcp_log_addrs(&sc->sc_inc, NULL, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Response timeout, "
"retransmitting (%u) SYN|ACK\n",
s, __func__, sc->sc_rxmits);
free(s, M_TCPLOG);
}
NET_EPOCH_ENTER(et);
if (syncache_respond(sc, TH_SYN|TH_ACK) == 0) {
syncache_timeout(sc, sch, 0);
TCPSTAT_INC(tcps_sndacks);
TCPSTAT_INC(tcps_sndtotal);
TCPSTAT_INC(tcps_sc_retransmitted);
} else {
/*
* Most likely we are memory constrained, so free
* resources.
*/
syncache_drop(sc, sch);
TCPSTAT_INC(tcps_sc_dropped);
}
NET_EPOCH_EXIT(et);
}
if (!TAILQ_EMPTY(&(sch)->sch_bucket))
callout_reset(&(sch)->sch_timer, (sch)->sch_nextc - tick,
syncache_timer, (void *)(sch));
CURVNET_RESTORE();
}
/*
* Returns true if the system is only using cookies at the moment.
* This could be due to a sysadmin decision to only use cookies, or it
* could be due to the system detecting an attack.
*/
static inline bool
syncache_cookiesonly(void)
{
return ((V_tcp_syncookies && V_tcp_syncache.paused) ||
V_tcp_syncookiesonly);
}
/*
* Find the hash bucket for the given connection.
*/
static struct syncache_head *
syncache_hashbucket(struct in_conninfo *inc)
{
uint32_t hash;
/*
* The hash is built on foreign port + local port + foreign address.
* We rely on the fact that struct in_conninfo starts with 16 bits
* of foreign port, then 16 bits of local port then followed by 128
* bits of foreign address. In case of IPv4 address, the first 3
* 32-bit words of the address always are zeroes.
*/
hash = jenkins_hash32((uint32_t *)&inc->inc_ie, 5,
V_tcp_syncache.hash_secret) & V_tcp_syncache.hashmask;
return (&V_tcp_syncache.hashbase[hash]);
}
/*
* Find an entry in the syncache.
* Returns always with locked syncache_head plus a matching entry or NULL.
*/
static struct syncache *
syncache_lookup(struct in_conninfo *inc, struct syncache_head **schp)
{
struct syncache *sc;
struct syncache_head *sch;
*schp = sch = syncache_hashbucket(inc);
SCH_LOCK(sch);
/* Circle through bucket row to find matching entry. */
TAILQ_FOREACH(sc, &sch->sch_bucket, sc_hash)
if (bcmp(&inc->inc_ie, &sc->sc_inc.inc_ie,
sizeof(struct in_endpoints)) == 0)
break;
return (sc); /* Always returns with locked sch. */
}
/*
* This function is called when we get a RST for a
* non-existent connection, so that we can see if the
* connection is in the syn cache. If it is, zap it.
* If required send a challenge ACK.
*/
void
syncache_chkrst(struct in_conninfo *inc, struct tcphdr *th, uint16_t port)
{
struct syncache *sc;
struct syncache_head *sch;
char *s = NULL;
if (syncache_cookiesonly())
return;
sc = syncache_lookup(inc, &sch); /* returns locked sch */
SCH_LOCK_ASSERT(sch);
/*
* No corresponding connection was found in syncache.
* If syncookies are enabled and possibly exclusively
* used, or we are under memory pressure, a valid RST
* may not find a syncache entry. In that case we're
* done and no SYN|ACK retransmissions will happen.
* Otherwise the RST was misdirected or spoofed.
*/
if (sc == NULL) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Spurious RST without matching "
"syncache entry (possibly syncookie only), "
"segment ignored\n", s, __func__);
TCPSTAT_INC(tcps_badrst);
goto done;
}
/* The remote UDP encaps port does not match. */
if (sc->sc_port != port) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Spurious RST with matching "
"syncache entry but non-matching UDP encaps port, "
"segment ignored\n", s, __func__);
TCPSTAT_INC(tcps_badrst);
goto done;
}
/*
* If the RST bit is set, check the sequence number to see
* if this is a valid reset segment.
*
* RFC 793 page 37:
* In all states except SYN-SENT, all reset (RST) segments
* are validated by checking their SEQ-fields. A reset is
* valid if its sequence number is in the window.
*
* RFC 793 page 69:
* There are four cases for the acceptability test for an incoming
* segment:
*
* Segment Receive Test
* Length Window
* ------- ------- -------------------------------------------
* 0 0 SEG.SEQ = RCV.NXT
* 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
* >0 0 not acceptable
* >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
* or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
*
* Note that when receiving a SYN segment in the LISTEN state,
* IRS is set to SEG.SEQ and RCV.NXT is set to SEG.SEQ+1, as
* described in RFC 793, page 66.
*/
if ((SEQ_GEQ(th->th_seq, sc->sc_irs + 1) &&
SEQ_LT(th->th_seq, sc->sc_irs + 1 + sc->sc_wnd)) ||
(sc->sc_wnd == 0 && th->th_seq == sc->sc_irs + 1)) {
if (V_tcp_insecure_rst ||
th->th_seq == sc->sc_irs + 1) {
syncache_drop(sc, sch);
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG,
"%s; %s: Our SYN|ACK was rejected, "
"connection attempt aborted by remote "
"endpoint\n",
s, __func__);
TCPSTAT_INC(tcps_sc_reset);
} else {
TCPSTAT_INC(tcps_badrst);
/* Send challenge ACK. */
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: RST with invalid "
" SEQ %u != NXT %u (+WND %u), "
"sending challenge ACK\n",
s, __func__,
th->th_seq, sc->sc_irs + 1, sc->sc_wnd);
syncache_send_challenge_ack(sc);
}
} else {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: RST with invalid SEQ %u != "
"NXT %u (+WND %u), segment ignored\n",
s, __func__,
th->th_seq, sc->sc_irs + 1, sc->sc_wnd);
TCPSTAT_INC(tcps_badrst);
}
done:
if (s != NULL)
free(s, M_TCPLOG);
SCH_UNLOCK(sch);
}
void
syncache_unreach(struct in_conninfo *inc, tcp_seq th_seq, uint16_t port)
{
struct syncache *sc;
struct syncache_head *sch;
if (syncache_cookiesonly())
return;
sc = syncache_lookup(inc, &sch); /* returns locked sch */
SCH_LOCK_ASSERT(sch);
if (sc == NULL)
goto done;
/* If the port != sc_port, then it's a bogus ICMP msg */
if (port != sc->sc_port)
goto done;
/* If the sequence number != sc_iss, then it's a bogus ICMP msg */
if (ntohl(th_seq) != sc->sc_iss)
goto done;
/*
* If we've retransmitted 3 times and this is our second error,
* we remove the entry. Otherwise, we allow it to continue on.
* This prevents us from incorrectly nuking an entry during a
* spurious network outage.
*
* See tcp_notify().
*/
if ((sc->sc_flags & SCF_UNREACH) == 0 || sc->sc_rxmits < 3 + 1) {
sc->sc_flags |= SCF_UNREACH;
goto done;
}
syncache_drop(sc, sch);
TCPSTAT_INC(tcps_sc_unreach);
done:
SCH_UNLOCK(sch);
}
/*
* Build a new TCP socket structure from a syncache entry.
*
* On success return the newly created socket with its underlying inp locked.
*/
static struct socket *
syncache_socket(struct syncache *sc, struct socket *lso, struct mbuf *m)
{
struct inpcb *inp = NULL;
struct socket *so;
struct tcpcb *tp;
int error;
char *s;
NET_EPOCH_ASSERT();
/*
- * Ok, create the full blown connection, and set things up
- * as they would have been set up if we had created the
- * connection when the SYN arrived.
+ * Creation of a socket via solisten_clone() bypasses call to pr_attach.
+ * That's why there is some pasted code from soattach() and from
+ * tcp_usr_attach() here. This should improve once TCP is PR_SOCKBUF.
*/
if ((so = solisten_clone(lso)) == NULL)
goto allocfail;
+ mtx_init(&so->so_snd_mtx, "so_snd", NULL, MTX_DEF);
+ mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF);
+ so->so_snd.sb_mtx = &so->so_snd_mtx;
+ so->so_rcv.sb_mtx = &so->so_rcv_mtx;
+ error = soreserve(so, lso->sol_sbsnd_hiwat, lso->sol_sbrcv_hiwat);
+ if (error) {
+ sodealloc(so);
+ goto allocfail;
+ }
#ifdef MAC
mac_socketpeer_set_from_mbuf(m, so);
#endif
error = in_pcballoc(so, &V_tcbinfo);
if (error) {
sodealloc(so);
goto allocfail;
}
inp = sotoinpcb(so);
if ((tp = tcp_newtcpcb(inp, sototcpcb(lso))) == NULL) {
in_pcbfree(inp);
sodealloc(so);
goto allocfail;
}
inp->inp_inc.inc_flags = sc->sc_inc.inc_flags;
#ifdef INET6
if (sc->sc_inc.inc_flags & INC_ISIPV6) {
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
inp->in6p_laddr = sc->sc_inc.inc6_laddr;
} else {
inp->inp_vflag &= ~INP_IPV6;
inp->inp_vflag |= INP_IPV4;
#endif
inp->inp_ip_ttl = sc->sc_ip_ttl;
inp->inp_ip_tos = sc->sc_ip_tos;
inp->inp_laddr = sc->sc_inc.inc_laddr;
#ifdef INET6
}
#endif
inp->inp_lport = sc->sc_inc.inc_lport;
#ifdef INET6
if (inp->inp_vflag & INP_IPV6PROTO) {
struct inpcb *oinp = sotoinpcb(lso);
/*
* Inherit socket options from the listening socket.
* Note that in6p_inputopts are not (and should not be)
* copied, since it stores previously received options and is
* used to detect if each new option is different than the
* previous one and hence should be passed to a user.
* If we copied in6p_inputopts, a user would not be able to
* receive options just after calling the accept system call.
*/
inp->inp_flags |= oinp->inp_flags & INP_CONTROLOPTS;
if (oinp->in6p_outputopts)
inp->in6p_outputopts =
ip6_copypktopts(oinp->in6p_outputopts, M_NOWAIT);
inp->in6p_hops = oinp->in6p_hops;
}
if (sc->sc_inc.inc_flags & INC_ISIPV6) {
struct sockaddr_in6 sin6;
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(sin6);
sin6.sin6_addr = sc->sc_inc.inc6_faddr;
sin6.sin6_port = sc->sc_inc.inc_fport;
sin6.sin6_flowinfo = sin6.sin6_scope_id = 0;
INP_HASH_WLOCK(&V_tcbinfo);
error = in6_pcbconnect(inp, &sin6, thread0.td_ucred, false);
INP_HASH_WUNLOCK(&V_tcbinfo);
if (error != 0)
goto abort;
/* Override flowlabel from in6_pcbconnect. */
inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
inp->inp_flow |= sc->sc_flowlabel;
}
#endif /* INET6 */
#if defined(INET) && defined(INET6)
else
#endif
#ifdef INET
{
struct sockaddr_in sin;
inp->inp_options = (m) ? ip_srcroute(m) : NULL;
if (inp->inp_options == NULL) {
inp->inp_options = sc->sc_ipopts;
sc->sc_ipopts = NULL;
}
sin.sin_family = AF_INET;
sin.sin_len = sizeof(sin);
sin.sin_addr = sc->sc_inc.inc_faddr;
sin.sin_port = sc->sc_inc.inc_fport;
bzero((caddr_t)sin.sin_zero, sizeof(sin.sin_zero));
INP_HASH_WLOCK(&V_tcbinfo);
error = in_pcbconnect(inp, &sin, thread0.td_ucred);
INP_HASH_WUNLOCK(&V_tcbinfo);
if (error != 0)
goto abort;
}
#endif /* INET */
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
/* Copy old policy into new socket's. */
if (ipsec_copy_pcbpolicy(sotoinpcb(lso), inp) != 0)
printf("syncache_socket: could not copy policy\n");
#endif
if (sc->sc_flowtype != M_HASHTYPE_NONE) {
inp->inp_flowid = sc->sc_flowid;
inp->inp_flowtype = sc->sc_flowtype;
} else {
/* assign flowid by software RSS hash */
#ifdef INET6
if (sc->sc_inc.inc_flags & INC_ISIPV6) {
rss_proto_software_hash_v6(&inp->in6p_faddr,
&inp->in6p_laddr,
inp->inp_fport,
inp->inp_lport,
IPPROTO_TCP,
&inp->inp_flowid,
&inp->inp_flowtype);
} else
#endif /* INET6 */
{
#ifdef INET
rss_proto_software_hash_v4(inp->inp_faddr,
inp->inp_laddr,
inp->inp_fport,
inp->inp_lport,
IPPROTO_TCP,
&inp->inp_flowid,
&inp->inp_flowtype);
#endif /* INET */
}
}
#ifdef NUMA
inp->inp_numa_domain = sc->sc_numa_domain;
#endif
tp->t_state = TCPS_SYN_RECEIVED;
tp->iss = sc->sc_iss;
tp->irs = sc->sc_irs;
tp->t_port = sc->sc_port;
tcp_rcvseqinit(tp);
tcp_sendseqinit(tp);
tp->snd_wl1 = sc->sc_irs;
tp->snd_max = tp->iss + 1;
tp->snd_nxt = tp->iss + 1;
tp->rcv_up = sc->sc_irs + 1;
tp->rcv_wnd = sc->sc_wnd;
tp->rcv_adv += tp->rcv_wnd;
tp->last_ack_sent = tp->rcv_nxt;
tp->t_flags = sototcpcb(lso)->t_flags &
(TF_LRD|TF_NOPUSH|TF_NODELAY);
if (sc->sc_flags & SCF_NOOPT)
tp->t_flags |= TF_NOOPT;
else {
if (sc->sc_flags & SCF_WINSCALE) {
tp->t_flags |= TF_REQ_SCALE|TF_RCVD_SCALE;
tp->snd_scale = sc->sc_requested_s_scale;
tp->request_r_scale = sc->sc_requested_r_scale;
}
if (sc->sc_flags & SCF_TIMESTAMP) {
tp->t_flags |= TF_REQ_TSTMP|TF_RCVD_TSTMP;
tp->ts_recent = sc->sc_tsreflect;
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_offset = sc->sc_tsoff;
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
if (sc->sc_flags & SCF_SIGNATURE)
tp->t_flags |= TF_SIGNATURE;
#endif
if (sc->sc_flags & SCF_SACK)
tp->t_flags |= TF_SACK_PERMIT;
}
tcp_ecn_syncache_socket(tp, sc);
/*
* Set up MSS and get cached values from tcp_hostcache.
* This might overwrite some of the defaults we just set.
*/
tcp_mss(tp, sc->sc_peer_mss);
/*
* If the SYN,ACK was retransmitted, indicate that CWND to be
* limited to one segment in cc_conn_init().
* NB: sc_rxmits counts all SYN,ACK transmits, not just retransmits.
*/
if (sc->sc_rxmits > 1)
tp->snd_cwnd = 1;
/* Copy over the challenge ACK state. */
tp->t_challenge_ack_end = sc->sc_challenge_ack_end;
tp->t_challenge_ack_cnt = sc->sc_challenge_ack_cnt;
#ifdef TCP_OFFLOAD
/*
* Allow a TOE driver to install its hooks. Note that we hold the
* pcbinfo lock too and that prevents tcp_usr_accept from accepting a
* new connection before the TOE driver has done its thing.
*/
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
tod->tod_offload_socket(tod, sc->sc_todctx, so);
}
#endif
#ifdef TCP_BLACKBOX
/*
* Inherit the log state from the listening socket, if
* - the log state of the listening socket is not off and
* - the listening socket was not auto selected from all sessions and
* - a log id is not set on the listening socket.
* This avoids inheriting a log state which was automatically set.
*/
if ((tcp_get_bblog_state(sototcpcb(lso)) != TCP_LOG_STATE_OFF) &&
((sototcpcb(lso)->t_flags2 & TF2_LOG_AUTO) == 0) &&
(sototcpcb(lso)->t_lib == NULL)) {
tcp_log_state_change(tp, tcp_get_bblog_state(sototcpcb(lso)));
}
#endif
/*
* Copy and activate timers.
*/
tp->t_maxunacktime = sototcpcb(lso)->t_maxunacktime;
tp->t_keepinit = sototcpcb(lso)->t_keepinit;
tp->t_keepidle = sototcpcb(lso)->t_keepidle;
tp->t_keepintvl = sototcpcb(lso)->t_keepintvl;
tp->t_keepcnt = sototcpcb(lso)->t_keepcnt;
tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
TCPSTAT_INC(tcps_accepts);
TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, TCPS_LISTEN);
if (!solisten_enqueue(so, SS_ISCONNECTED))
tp->t_flags |= TF_SONOTCONN;
/* Can we inherit anything from the listener? */
if (tp->t_fb->tfb_inherit != NULL) {
(*tp->t_fb->tfb_inherit)(tp, sotoinpcb(lso));
}
return (so);
allocfail:
/*
* Drop the connection; we will either send a RST or have the peer
* retransmit its SYN again after its RTO and try again.
*/
if ((s = tcp_log_addrs(&sc->sc_inc, NULL, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Socket create failed "
"due to limits or memory shortage\n",
s, __func__);
free(s, M_TCPLOG);
}
TCPSTAT_INC(tcps_listendrop);
return (NULL);
abort:
tcp_discardcb(tp);
in_pcbfree(inp);
sodealloc(so);
if ((s = tcp_log_addrs(&sc->sc_inc, NULL, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: in%s_pcbconnect failed with error %i\n",
s, __func__, (sc->sc_inc.inc_flags & INC_ISIPV6) ? "6" : "",
error);
free(s, M_TCPLOG);
}
TCPSTAT_INC(tcps_listendrop);
return (NULL);
}
/*
* This function gets called when we receive an ACK for a
* socket in the LISTEN state. We look up the connection
* in the syncache, and if its there, we pull it out of
* the cache and turn it into a full-blown connection in
* the SYN-RECEIVED state.
*
* On syncache_socket() success the newly created socket
* has its underlying inp locked.
*
* *lsop is updated, if and only if 1 is returned.
*/
int
syncache_expand(struct in_conninfo *inc, struct tcpopt *to, struct tcphdr *th,
struct socket **lsop, struct mbuf *m, uint16_t port)
{
struct syncache *sc;
struct syncache_head *sch;
struct syncache scs;
char *s;
bool locked;
NET_EPOCH_ASSERT();
KASSERT((tcp_get_flags(th) & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK,
("%s: can handle only ACK", __func__));
if (syncache_cookiesonly()) {
sc = NULL;
sch = syncache_hashbucket(inc);
locked = false;
} else {
sc = syncache_lookup(inc, &sch); /* returns locked sch */
locked = true;
SCH_LOCK_ASSERT(sch);
}
#ifdef INVARIANTS
/*
* Test code for syncookies comparing the syncache stored
* values with the reconstructed values from the cookie.
*/
if (sc != NULL)
syncookie_cmp(inc, sch, sc, th, to, *lsop, port);
#endif
if (sc == NULL) {
if (locked) {
/*
* The syncache is currently in use (neither disabled,
* nor paused), but no entry was found.
*/
if (!V_tcp_syncookies) {
/*
* Since no syncookies are used in case of
* a bucket overflow, don't even check for
* a valid syncookie.
*/
SCH_UNLOCK(sch);
TCPSTAT_INC(tcps_sc_spurcookie);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Spurious ACK, "
"segment rejected "
"(syncookies disabled)\n",
s, __func__);
free(s, M_TCPLOG);
}
return (0);
}
if (sch->sch_last_overflow <
time_uptime - SYNCOOKIE_LIFETIME) {
/*
* Since the bucket did not overflow recently,
* don't even check for a valid syncookie.
*/
SCH_UNLOCK(sch);
TCPSTAT_INC(tcps_sc_spurcookie);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Spurious ACK, "
"segment rejected "
"(no syncache entry)\n",
s, __func__);
free(s, M_TCPLOG);
}
return (0);
}
SCH_UNLOCK(sch);
}
bzero(&scs, sizeof(scs));
/*
* Now check, if the syncookie is valid. If it is, create an on
* stack syncache entry.
*/
if (syncookie_expand(inc, sch, &scs, th, to, *lsop, port)) {
sc = &scs;
TCPSTAT_INC(tcps_sc_recvcookie);
} else {
TCPSTAT_INC(tcps_sc_failcookie);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Segment failed "
"SYNCOOKIE authentication, segment rejected "
"(probably spoofed)\n", s, __func__);
free(s, M_TCPLOG);
}
return (0);
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/* If received ACK has MD5 signature, check it. */
if ((to->to_flags & TOF_SIGNATURE) != 0 &&
(!TCPMD5_ENABLED() ||
TCPMD5_INPUT(m, th, to->to_signature) != 0)) {
/* Drop the ACK. */
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Segment rejected, "
"MD5 signature doesn't match.\n",
s, __func__);
free(s, M_TCPLOG);
}
TCPSTAT_INC(tcps_sig_err_sigopt);
return (-1); /* Do not send RST */
}
#endif /* TCP_SIGNATURE */
if (m != NULL && M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
sc->sc_flowid = m->m_pkthdr.flowid;
sc->sc_flowtype = M_HASHTYPE_GET(m);
}
#ifdef NUMA
sc->sc_numa_domain = m ? m->m_pkthdr.numa_domain : M_NODOM;
#endif
TCPSTATES_INC(TCPS_SYN_RECEIVED);
} else {
if (sc->sc_port != port) {
SCH_UNLOCK(sch);
return (0);
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/*
* If listening socket requested TCP digests, check that
* received ACK has signature and it is correct.
* If not, drop the ACK and leave sc entry in the cache,
* because SYN was received with correct signature.
*/
if (sc->sc_flags & SCF_SIGNATURE) {
if ((to->to_flags & TOF_SIGNATURE) == 0) {
/* No signature */
TCPSTAT_INC(tcps_sig_err_nosigopt);
SCH_UNLOCK(sch);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Segment "
"rejected, MD5 signature wasn't "
"provided.\n", s, __func__);
free(s, M_TCPLOG);
}
return (-1); /* Do not send RST */
}
if (!TCPMD5_ENABLED() ||
TCPMD5_INPUT(m, th, to->to_signature) != 0) {
/* Doesn't match or no SA */
SCH_UNLOCK(sch);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Segment "
"rejected, MD5 signature doesn't "
"match.\n", s, __func__);
free(s, M_TCPLOG);
}
return (-1); /* Do not send RST */
}
}
#endif /* TCP_SIGNATURE */
/*
* RFC 7323 PAWS: If we have a timestamp on this segment and
* it's less than ts_recent, drop it.
* XXXMT: RFC 7323 also requires to send an ACK.
* In tcp_input.c this is only done for TCP segments
* with user data, so be consistent here and just drop
* the segment.
*/
if (sc->sc_flags & SCF_TIMESTAMP && to->to_flags & TOF_TS &&
TSTMP_LT(to->to_tsval, sc->sc_tsreflect)) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG,
"%s; %s: SEG.TSval %u < TS.Recent %u, "
"segment dropped\n", s, __func__,
to->to_tsval, sc->sc_tsreflect);
}
SCH_UNLOCK(sch);
free(s, M_TCPLOG);
return (-1); /* Do not send RST */
}
/*
* If timestamps were not negotiated during SYN/ACK and a
* segment with a timestamp is received, ignore the
* timestamp and process the packet normally.
* See section 3.2 of RFC 7323.
*/
if (!(sc->sc_flags & SCF_TIMESTAMP) &&
(to->to_flags & TOF_TS)) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Timestamp not "
"expected, segment processed normally\n",
s, __func__);
free(s, M_TCPLOG);
}
}
/*
* If timestamps were negotiated during SYN/ACK and a
* segment without a timestamp is received, silently drop
* the segment, unless the missing timestamps are tolerated.
* See section 3.2 of RFC 7323.
*/
if ((sc->sc_flags & SCF_TIMESTAMP) &&
!(to->to_flags & TOF_TS)) {
if (V_tcp_tolerate_missing_ts) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG,
"%s; %s: Timestamp missing, "
"segment processed normally\n",
s, __func__);
free(s, M_TCPLOG);
}
} else {
SCH_UNLOCK(sch);
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG,
"%s; %s: Timestamp missing, "
"segment silently dropped\n",
s, __func__);
free(s, M_TCPLOG);
}
return (-1); /* Do not send RST */
}
}
/*
* SEG.SEQ validation:
* The SEG.SEQ must be in the window starting at our
* initial receive sequence number + 1.
*/
if (SEQ_LEQ(th->th_seq, sc->sc_irs) ||
SEQ_GT(th->th_seq, sc->sc_irs + sc->sc_wnd)) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: SEQ %u != IRS+1 %u, "
"sending challenge ACK\n",
s, __func__, th->th_seq, sc->sc_irs + 1);
syncache_send_challenge_ack(sc);
SCH_UNLOCK(sch);
free(s, M_TCPLOG);
return (-1); /* Do not send RST */
}
/*
* SEG.ACK validation:
* SEG.ACK must match our initial send sequence number + 1.
*/
if (th->th_ack != sc->sc_iss + 1) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: ACK %u != ISS+1 %u, "
"segment rejected\n",
s, __func__, th->th_ack, sc->sc_iss + 1);
SCH_UNLOCK(sch);
free(s, M_TCPLOG);
return (0); /* Do send RST, do not free sc. */
}
TAILQ_REMOVE(&sch->sch_bucket, sc, sc_hash);
sch->sch_length--;
#ifdef TCP_OFFLOAD
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
tod->tod_syncache_removed(tod, sc->sc_todctx);
}
#endif
SCH_UNLOCK(sch);
}
*lsop = syncache_socket(sc, *lsop, m);
if (__predict_false(*lsop == NULL)) {
TCPSTAT_INC(tcps_sc_aborted);
TCPSTATES_DEC(TCPS_SYN_RECEIVED);
} else if (sc != &scs)
TCPSTAT_INC(tcps_sc_completed);
if (sc != &scs)
syncache_free(sc);
return (1);
}
static struct socket *
syncache_tfo_expand(struct syncache *sc, struct socket *lso, struct mbuf *m,
uint64_t response_cookie)
{
struct inpcb *inp;
struct tcpcb *tp;
unsigned int *pending_counter;
struct socket *so;
NET_EPOCH_ASSERT();
pending_counter = intotcpcb(sotoinpcb(lso))->t_tfo_pending;
so = syncache_socket(sc, lso, m);
if (so == NULL) {
TCPSTAT_INC(tcps_sc_aborted);
atomic_subtract_int(pending_counter, 1);
} else {
soisconnected(so);
inp = sotoinpcb(so);
tp = intotcpcb(inp);
tp->t_flags |= TF_FASTOPEN;
tp->t_tfo_cookie.server = response_cookie;
tp->snd_max = tp->iss;
tp->snd_nxt = tp->iss;
tp->t_tfo_pending = pending_counter;
TCPSTATES_INC(TCPS_SYN_RECEIVED);
TCPSTAT_INC(tcps_sc_completed);
}
return (so);
}
/*
* Given a LISTEN socket and an inbound SYN request, add
* this to the syn cache, and send back a segment:
* <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK>
* to the source.
*
* IMPORTANT NOTE: We do _NOT_ ACK data that might accompany the SYN.
* Doing so would require that we hold onto the data and deliver it
* to the application. However, if we are the target of a SYN-flood
* DoS attack, an attacker could send data which would eventually
* consume all available buffer space if it were ACKed. By not ACKing
* the data, we avoid this DoS scenario.
*
* The exception to the above is when a SYN with a valid TCP Fast Open (TFO)
* cookie is processed and a new socket is created. In this case, any data
* accompanying the SYN will be queued to the socket by tcp_input() and will
* be ACKed either when the application sends response data or the delayed
* ACK timer expires, whichever comes first.
*/
struct socket *
syncache_add(struct in_conninfo *inc, struct tcpopt *to, struct tcphdr *th,
struct inpcb *inp, struct socket *so, struct mbuf *m, void *tod,
void *todctx, uint8_t iptos, uint16_t port)
{
struct tcpcb *tp;
struct socket *rv = NULL;
struct syncache *sc = NULL;
struct ucred *cred;
struct syncache_head *sch;
struct mbuf *ipopts = NULL;
u_int ltflags;
int win, ip_ttl, ip_tos;
char *s;
#ifdef INET6
int autoflowlabel = 0;
#endif
#ifdef MAC
struct label *maclabel = NULL;
#endif
struct syncache scs;
uint64_t tfo_response_cookie;
unsigned int *tfo_pending = NULL;
int tfo_cookie_valid = 0;
int tfo_response_cookie_valid = 0;
bool locked;
INP_RLOCK_ASSERT(inp); /* listen socket */
KASSERT((tcp_get_flags(th) & (TH_RST|TH_ACK|TH_SYN)) == TH_SYN,
("%s: unexpected tcp flags", __func__));
/*
* Combine all so/tp operations very early to drop the INP lock as
* soon as possible.
*/
KASSERT(SOLISTENING(so), ("%s: %p not listening", __func__, so));
tp = sototcpcb(so);
cred = V_tcp_syncache.see_other ? NULL : crhold(so->so_cred);
#ifdef INET6
if (inc->inc_flags & INC_ISIPV6) {
if (inp->inp_flags & IN6P_AUTOFLOWLABEL) {
autoflowlabel = 1;
}
ip_ttl = in6_selecthlim(inp, NULL);
if ((inp->in6p_outputopts == NULL) ||
(inp->in6p_outputopts->ip6po_tclass == -1)) {
ip_tos = 0;
} else {
ip_tos = inp->in6p_outputopts->ip6po_tclass;
}
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
ip_ttl = inp->inp_ip_ttl;
ip_tos = inp->inp_ip_tos;
}
#endif
win = so->sol_sbrcv_hiwat;
ltflags = (tp->t_flags & (TF_NOOPT | TF_SIGNATURE));
if (V_tcp_fastopen_server_enable && (tp->t_flags & TF_FASTOPEN) &&
(tp->t_tfo_pending != NULL) &&
(to->to_flags & TOF_FASTOPEN)) {
/*
* Limit the number of pending TFO connections to
* approximately half of the queue limit. This prevents TFO
* SYN floods from starving the service by filling the
* listen queue with bogus TFO connections.
*/
if (atomic_fetchadd_int(tp->t_tfo_pending, 1) <=
(so->sol_qlimit / 2)) {
int result;
result = tcp_fastopen_check_cookie(inc,
to->to_tfo_cookie, to->to_tfo_len,
&tfo_response_cookie);
tfo_cookie_valid = (result > 0);
tfo_response_cookie_valid = (result >= 0);
}
/*
* Remember the TFO pending counter as it will have to be
* decremented below if we don't make it to syncache_tfo_expand().
*/
tfo_pending = tp->t_tfo_pending;
}
#ifdef MAC
if (mac_syncache_init(&maclabel) != 0) {
INP_RUNLOCK(inp);
goto done;
} else
mac_syncache_create(maclabel, inp);
#endif
if (!tfo_cookie_valid)
INP_RUNLOCK(inp);
/*
* Remember the IP options, if any.
*/
#ifdef INET6
if (!(inc->inc_flags & INC_ISIPV6))
#endif
#ifdef INET
ipopts = (m) ? ip_srcroute(m) : NULL;
#else
ipopts = NULL;
#endif
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/*
* When the socket is TCP-MD5 enabled check that,
* - a signed packet is valid
* - a non-signed packet does not have a security association
*
* If a signed packet fails validation or a non-signed packet has a
* security association, the packet will be dropped.
*/
if (ltflags & TF_SIGNATURE) {
if (to->to_flags & TOF_SIGNATURE) {
if (!TCPMD5_ENABLED() ||
TCPMD5_INPUT(m, th, to->to_signature) != 0)
goto done;
} else {
if (TCPMD5_ENABLED() &&
TCPMD5_INPUT(m, NULL, NULL) != ENOENT)
goto done;
}
} else if (to->to_flags & TOF_SIGNATURE)
goto done;
#endif /* TCP_SIGNATURE */
/*
* See if we already have an entry for this connection.
* If we do, resend the SYN,ACK, and reset the retransmit timer.
*
* XXX: should the syncache be re-initialized with the contents
* of the new SYN here (which may have different options?)
*
* XXX: We do not check the sequence number to see if this is a
* real retransmit or a new connection attempt. The question is
* how to handle such a case; either ignore it as spoofed, or
* drop the current entry and create a new one?
*/
if (syncache_cookiesonly()) {
sc = NULL;
sch = syncache_hashbucket(inc);
locked = false;
} else {
sc = syncache_lookup(inc, &sch); /* returns locked sch */
locked = true;
SCH_LOCK_ASSERT(sch);
}
if (sc != NULL) {
if (tfo_cookie_valid)
INP_RUNLOCK(inp);
TCPSTAT_INC(tcps_sc_dupsyn);
if (ipopts) {
/*
* If we were remembering a previous source route,
* forget it and use the new one we've been given.
*/
if (sc->sc_ipopts)
(void)m_free(sc->sc_ipopts);
sc->sc_ipopts = ipopts;
}
/*
* Update timestamp if present.
*/
if ((sc->sc_flags & SCF_TIMESTAMP) && (to->to_flags & TOF_TS))
sc->sc_tsreflect = to->to_tsval;
else
sc->sc_flags &= ~SCF_TIMESTAMP;
/*
* Adjust ECN response if needed, e.g. different
* IP ECN field, or a fallback by the remote host.
*/
if (sc->sc_flags & SCF_ECN_MASK) {
sc->sc_flags &= ~SCF_ECN_MASK;
sc->sc_flags |= tcp_ecn_syncache_add(tcp_get_flags(th), iptos);
}
#ifdef MAC
/*
* Since we have already unconditionally allocated label
* storage, free it up. The syncache entry will already
* have an initialized label we can use.
*/
mac_syncache_destroy(&maclabel);
#endif
TCP_PROBE5(receive, NULL, NULL, m, NULL, th);
/* Retransmit SYN|ACK and reset retransmit count. */
if ((s = tcp_log_addrs(&sc->sc_inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Received duplicate SYN, "
"resetting timer and retransmitting SYN|ACK\n",
s, __func__);
free(s, M_TCPLOG);
}
if (syncache_respond(sc, TH_SYN|TH_ACK) == 0) {
sc->sc_rxmits = 0;
syncache_timeout(sc, sch, 1);
TCPSTAT_INC(tcps_sndacks);
TCPSTAT_INC(tcps_sndtotal);
} else {
/*
* Most likely we are memory constrained, so free
* resources.
*/
syncache_drop(sc, sch);
TCPSTAT_INC(tcps_sc_dropped);
}
SCH_UNLOCK(sch);
goto donenoprobe;
}
KASSERT(sc == NULL, ("sc(%p) != NULL", sc));
/*
* Skip allocating a syncache entry if we are just going to discard
* it later.
*/
if (!locked || tfo_cookie_valid) {
bzero(&scs, sizeof(scs));
sc = &scs;
} else {
sc = uma_zalloc(V_tcp_syncache.zone, M_NOWAIT | M_ZERO);
if (sc == NULL) {
/*
* The zone allocator couldn't provide more entries.
* Treat this as if the cache was full; drop the oldest
* entry and insert the new one.
*/
TCPSTAT_INC(tcps_sc_zonefail);
sc = TAILQ_LAST(&sch->sch_bucket, sch_head);
if (sc != NULL) {
sch->sch_last_overflow = time_uptime;
syncache_drop(sc, sch);
syncache_pause(inc);
}
sc = uma_zalloc(V_tcp_syncache.zone, M_NOWAIT | M_ZERO);
if (sc == NULL) {
if (V_tcp_syncookies) {
bzero(&scs, sizeof(scs));
sc = &scs;
} else {
KASSERT(locked,
("%s: bucket unexpectedly unlocked",
__func__));
SCH_UNLOCK(sch);
goto done;
}
}
}
}
KASSERT(sc != NULL, ("sc == NULL"));
if (!tfo_cookie_valid && tfo_response_cookie_valid)
sc->sc_tfo_cookie = &tfo_response_cookie;
/*
* Fill in the syncache values.
*/
#ifdef MAC
sc->sc_label = maclabel;
#endif
/*
* sc_cred is only used in syncache_pcblist() to list TCP endpoints in
* TCPS_SYN_RECEIVED state when V_tcp_syncache.see_other is false.
* Therefore, store the credentials only when needed:
* - sc is allocated from the zone and not using the on stack instance.
* - the sysctl variable net.inet.tcp.syncache.see_other is false.
* The reference count is decremented when a zone allocated sc is
* freed in syncache_free().
*/
if (sc != &scs && !V_tcp_syncache.see_other) {
sc->sc_cred = cred;
cred = NULL;
} else
sc->sc_cred = NULL;
sc->sc_port = port;
sc->sc_ipopts = ipopts;
bcopy(inc, &sc->sc_inc, sizeof(struct in_conninfo));
sc->sc_ip_tos = ip_tos;
sc->sc_ip_ttl = ip_ttl;
#ifdef TCP_OFFLOAD
sc->sc_tod = tod;
sc->sc_todctx = todctx;
#endif
sc->sc_irs = th->th_seq;
sc->sc_flags = 0;
sc->sc_flowlabel = 0;
/*
* Initial receive window: clip sbspace to [0 .. TCP_MAXWIN].
* win was derived from socket earlier in the function.
*/
win = imax(win, 0);
win = imin(win, TCP_MAXWIN);
sc->sc_wnd = win;
if (V_tcp_do_rfc1323 &&
!(ltflags & TF_NOOPT)) {
/*
* A timestamp received in a SYN makes
* it ok to send timestamp requests and replies.
*/
if ((to->to_flags & TOF_TS) && (V_tcp_do_rfc1323 != 2)) {
sc->sc_tsreflect = to->to_tsval;
sc->sc_flags |= SCF_TIMESTAMP;
sc->sc_tsoff = tcp_new_ts_offset(inc);
}
if ((to->to_flags & TOF_SCALE) && (V_tcp_do_rfc1323 != 3)) {
u_int wscale = 0;
/*
* Pick the smallest possible scaling factor that
* will still allow us to scale up to sb_max, aka
* kern.ipc.maxsockbuf.
*
* We do this because there are broken firewalls that
* will corrupt the window scale option, leading to
* the other endpoint believing that our advertised
* window is unscaled. At scale factors larger than
* 5 the unscaled window will drop below 1500 bytes,
* leading to serious problems when traversing these
* broken firewalls.
*
* With the default maxsockbuf of 256K, a scale factor
* of 3 will be chosen by this algorithm. Those who
* choose a larger maxsockbuf should watch out
* for the compatibility problems mentioned above.
*
* RFC1323: The Window field in a SYN (i.e., a <SYN>
* or <SYN,ACK>) segment itself is never scaled.
*/
while (wscale < TCP_MAX_WINSHIFT &&
(TCP_MAXWIN << wscale) < sb_max)
wscale++;
sc->sc_requested_r_scale = wscale;
sc->sc_requested_s_scale = to->to_wscale;
sc->sc_flags |= SCF_WINSCALE;
}
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/*
* If incoming packet has an MD5 signature, flag this in the
* syncache so that syncache_respond() will do the right thing
* with the SYN+ACK.
*/
if (to->to_flags & TOF_SIGNATURE)
sc->sc_flags |= SCF_SIGNATURE;
#endif /* TCP_SIGNATURE */
if (to->to_flags & TOF_SACKPERM)
sc->sc_flags |= SCF_SACK;
if (to->to_flags & TOF_MSS)
sc->sc_peer_mss = to->to_mss; /* peer mss may be zero */
if (ltflags & TF_NOOPT)
sc->sc_flags |= SCF_NOOPT;
/* ECN Handshake */
if (V_tcp_do_ecn && (tp->t_flags2 & TF2_CANNOT_DO_ECN) == 0)
sc->sc_flags |= tcp_ecn_syncache_add(tcp_get_flags(th), iptos);
if (V_tcp_syncookies || V_tcp_syncookiesonly)
sc->sc_iss = syncookie_generate(sch, sc);
else
sc->sc_iss = arc4random();
#ifdef INET6
if (autoflowlabel) {
if (V_tcp_syncookies || V_tcp_syncookiesonly)
sc->sc_flowlabel = sc->sc_iss;
else
sc->sc_flowlabel = ip6_randomflowlabel();
sc->sc_flowlabel = htonl(sc->sc_flowlabel) & IPV6_FLOWLABEL_MASK;
}
#endif
if (m != NULL && M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
sc->sc_flowid = m->m_pkthdr.flowid;
sc->sc_flowtype = M_HASHTYPE_GET(m);
}
#ifdef NUMA
sc->sc_numa_domain = m ? m->m_pkthdr.numa_domain : M_NODOM;
#endif
if (locked)
SCH_UNLOCK(sch);
if (tfo_cookie_valid) {
rv = syncache_tfo_expand(sc, so, m, tfo_response_cookie);
/* INP_RUNLOCK(inp) will be performed by the caller */
goto tfo_expanded;
}
TCP_PROBE5(receive, NULL, NULL, m, NULL, th);
/*
* Do a standard 3-way handshake.
*/
if (syncache_respond(sc, TH_SYN|TH_ACK) == 0) {
if (sc != &scs)
syncache_insert(sc, sch); /* locks and unlocks sch */
TCPSTAT_INC(tcps_sndacks);
TCPSTAT_INC(tcps_sndtotal);
} else {
/*
* Most likely we are memory constrained, so free resources.
*/
if (sc != &scs)
syncache_free(sc);
TCPSTAT_INC(tcps_sc_dropped);
}
goto donenoprobe;
done:
TCP_PROBE5(receive, NULL, NULL, m, NULL, th);
donenoprobe:
if (m)
m_freem(m);
/*
* If tfo_pending is not NULL here, then a TFO SYN that did not
* result in a new socket was processed and the associated pending
* counter has not yet been decremented. All such TFO processing paths
* transit this point.
*/
if (tfo_pending != NULL)
tcp_fastopen_decrement_counter(tfo_pending);
tfo_expanded:
if (cred != NULL)
crfree(cred);
if (sc == NULL || sc == &scs) {
#ifdef MAC
mac_syncache_destroy(&maclabel);
#endif
if (ipopts)
(void)m_free(ipopts);
}
return (rv);
}
/*
* Send SYN|ACK or ACK to the peer. Either in response to a peer's segment
* or upon 3WHS ACK timeout.
*/
static int
syncache_respond(struct syncache *sc, int flags)
{
struct ip *ip = NULL;
struct mbuf *m;
struct tcphdr *th = NULL;
struct udphdr *udp = NULL;
int optlen, error = 0; /* Make compiler happy */
u_int16_t hlen, tlen, mssopt, ulen;
struct tcpopt to;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
#endif
NET_EPOCH_ASSERT();
hlen =
#ifdef INET6
(sc->sc_inc.inc_flags & INC_ISIPV6) ? sizeof(struct ip6_hdr) :
#endif
sizeof(struct ip);
tlen = hlen + sizeof(struct tcphdr);
if (sc->sc_port) {
tlen += sizeof(struct udphdr);
}
/* Determine MSS we advertize to other end of connection. */
mssopt = tcp_mssopt(&sc->sc_inc);
if (sc->sc_port)
mssopt -= V_tcp_udp_tunneling_overhead;
mssopt = max(mssopt, V_tcp_minmss);
/* XXX: Assume that the entire packet will fit in a header mbuf. */
KASSERT(max_linkhdr + tlen + TCP_MAXOLEN <= MHLEN,
("syncache: mbuf too small: hlen %u, sc_port %u, max_linkhdr %d + "
"tlen %d + TCP_MAXOLEN %ju <= MHLEN %d", hlen, sc->sc_port,
max_linkhdr, tlen, (uintmax_t)TCP_MAXOLEN, MHLEN));
/* Create the IP+TCP header from scratch. */
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL)
return (ENOBUFS);
#ifdef MAC
mac_syncache_create_mbuf(sc->sc_label, m);
#endif
m->m_data += max_linkhdr;
m->m_len = tlen;
m->m_pkthdr.len = tlen;
m->m_pkthdr.rcvif = NULL;
#ifdef INET6
if (sc->sc_inc.inc_flags & INC_ISIPV6) {
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_vfc = IPV6_VERSION;
ip6->ip6_src = sc->sc_inc.inc6_laddr;
ip6->ip6_dst = sc->sc_inc.inc6_faddr;
ip6->ip6_plen = htons(tlen - hlen);
/* ip6_hlim is set after checksum */
/* Zero out traffic class and flow label. */
ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK;
ip6->ip6_flow |= sc->sc_flowlabel;
if (sc->sc_port != 0) {
ip6->ip6_nxt = IPPROTO_UDP;
udp = (struct udphdr *)(ip6 + 1);
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = sc->sc_port;
ulen = (tlen - sizeof(struct ip6_hdr));
th = (struct tcphdr *)(udp + 1);
} else {
ip6->ip6_nxt = IPPROTO_TCP;
th = (struct tcphdr *)(ip6 + 1);
}
ip6->ip6_flow |= htonl(sc->sc_ip_tos << IPV6_FLOWLABEL_LEN);
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
ip = mtod(m, struct ip *);
ip->ip_v = IPVERSION;
ip->ip_hl = sizeof(struct ip) >> 2;
ip->ip_len = htons(tlen);
ip->ip_id = 0;
ip->ip_off = 0;
ip->ip_sum = 0;
ip->ip_src = sc->sc_inc.inc_laddr;
ip->ip_dst = sc->sc_inc.inc_faddr;
ip->ip_ttl = sc->sc_ip_ttl;
ip->ip_tos = sc->sc_ip_tos;
/*
* See if we should do MTU discovery. Route lookups are
* expensive, so we will only unset the DF bit if:
*
* 1) path_mtu_discovery is disabled
* 2) the SCF_UNREACH flag has been set
*/
if (V_path_mtu_discovery && ((sc->sc_flags & SCF_UNREACH) == 0))
ip->ip_off |= htons(IP_DF);
if (sc->sc_port == 0) {
ip->ip_p = IPPROTO_TCP;
th = (struct tcphdr *)(ip + 1);
} else {
ip->ip_p = IPPROTO_UDP;
udp = (struct udphdr *)(ip + 1);
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = sc->sc_port;
ulen = (tlen - sizeof(struct ip));
th = (struct tcphdr *)(udp + 1);
}
}
#endif /* INET */
th->th_sport = sc->sc_inc.inc_lport;
th->th_dport = sc->sc_inc.inc_fport;
if (flags & TH_SYN)
th->th_seq = htonl(sc->sc_iss);
else
th->th_seq = htonl(sc->sc_iss + 1);
th->th_ack = htonl(sc->sc_irs + 1);
th->th_off = sizeof(struct tcphdr) >> 2;
th->th_win = htons(sc->sc_wnd);
th->th_urp = 0;
flags = tcp_ecn_syncache_respond(flags, sc);
tcp_set_flags(th, flags);
/* Tack on the TCP options. */
if ((sc->sc_flags & SCF_NOOPT) == 0) {
to.to_flags = 0;
if (flags & TH_SYN) {
to.to_mss = mssopt;
to.to_flags = TOF_MSS;
if (sc->sc_flags & SCF_WINSCALE) {
to.to_wscale = sc->sc_requested_r_scale;
to.to_flags |= TOF_SCALE;
}
if (sc->sc_flags & SCF_SACK)
to.to_flags |= TOF_SACKPERM;
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
if (sc->sc_flags & SCF_SIGNATURE)
to.to_flags |= TOF_SIGNATURE;
#endif
if (sc->sc_tfo_cookie) {
to.to_flags |= TOF_FASTOPEN;
to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
to.to_tfo_cookie = sc->sc_tfo_cookie;
/* don't send cookie again when retransmitting response */
sc->sc_tfo_cookie = NULL;
}
}
if (sc->sc_flags & SCF_TIMESTAMP) {
to.to_tsval = sc->sc_tsoff + tcp_ts_getticks();
to.to_tsecr = sc->sc_tsreflect;
to.to_flags |= TOF_TS;
}
optlen = tcp_addoptions(&to, (u_char *)(th + 1));
/* Adjust headers by option size. */
th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
m->m_len += optlen;
m->m_pkthdr.len += optlen;
#ifdef INET6
if (sc->sc_inc.inc_flags & INC_ISIPV6)
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) + optlen);
else
#endif
ip->ip_len = htons(ntohs(ip->ip_len) + optlen);
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
if (sc->sc_flags & SCF_SIGNATURE) {
KASSERT(to.to_flags & TOF_SIGNATURE,
("tcp_addoptions() didn't set tcp_signature"));
/* NOTE: to.to_signature is inside of mbuf */
if (!TCPMD5_ENABLED() ||
TCPMD5_OUTPUT(m, th, to.to_signature) != 0) {
m_freem(m);
return (EACCES);
}
}
#endif
} else
optlen = 0;
if (udp) {
ulen += optlen;
udp->uh_ulen = htons(ulen);
}
M_SETFIB(m, sc->sc_inc.inc_fibnum);
m->m_pkthdr.flowid = sc->sc_flowid;
M_HASHTYPE_SET(m, sc->sc_flowtype);
#ifdef NUMA
m->m_pkthdr.numa_domain = sc->sc_numa_domain;
#endif
#ifdef INET6
if (sc->sc_inc.inc_flags & INC_ISIPV6) {
if (sc->sc_port) {
m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in6_cksum_pseudo(ip6, ulen,
IPPROTO_UDP, 0);
th->th_sum = htons(0);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in6_cksum_pseudo(ip6, tlen + optlen - hlen,
IPPROTO_TCP, 0);
}
ip6->ip6_hlim = sc->sc_ip_ttl;
#ifdef TCP_OFFLOAD
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
error = tod->tod_syncache_respond(tod, sc->sc_todctx, m);
return (error);
}
#endif
TCP_PROBE5(send, NULL, NULL, ip6, NULL, th);
error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
if (sc->sc_port) {
m->m_pkthdr.csum_flags = CSUM_UDP;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
th->th_sum = htons(0);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htons(tlen + optlen - hlen + IPPROTO_TCP));
}
#ifdef TCP_OFFLOAD
if (ADDED_BY_TOE(sc)) {
struct toedev *tod = sc->sc_tod;
error = tod->tod_syncache_respond(tod, sc->sc_todctx, m);
return (error);
}
#endif
TCP_PROBE5(send, NULL, NULL, ip, NULL, th);
error = ip_output(m, sc->sc_ipopts, NULL, 0, NULL, NULL);
}
#endif
return (error);
}
static void
syncache_send_challenge_ack(struct syncache *sc)
{
if (tcp_challenge_ack_check(&sc->sc_challenge_ack_end,
&sc->sc_challenge_ack_cnt)) {
if (syncache_respond(sc, TH_ACK) == 0) {
TCPSTAT_INC(tcps_sndacks);
TCPSTAT_INC(tcps_sndtotal);
}
}
}
/*
* The purpose of syncookies is to handle spoofed SYN flooding DoS attacks
* that exceed the capacity of the syncache by avoiding the storage of any
* of the SYNs we receive. Syncookies defend against blind SYN flooding
* attacks where the attacker does not have access to our responses.
*
* Syncookies encode and include all necessary information about the
* connection setup within the SYN|ACK that we send back. That way we
* can avoid keeping any local state until the ACK to our SYN|ACK returns
* (if ever). Normally the syncache and syncookies are running in parallel
* with the latter taking over when the former is exhausted. When matching
* syncache entry is found the syncookie is ignored.
*
* The only reliable information persisting the 3WHS is our initial sequence
* number ISS of 32 bits. Syncookies embed a cryptographically sufficient
* strong hash (MAC) value and a few bits of TCP SYN options in the ISS
* of our SYN|ACK. The MAC can be recomputed when the ACK to our SYN|ACK
* returns and signifies a legitimate connection if it matches the ACK.
*
* The available space of 32 bits to store the hash and to encode the SYN
* option information is very tight and we should have at least 24 bits for
* the MAC to keep the number of guesses by blind spoofing reasonably high.
*
* SYN option information we have to encode to fully restore a connection:
* MSS: is imporant to chose an optimal segment size to avoid IP level
* fragmentation along the path. The common MSS values can be encoded
* in a 3-bit table. Uncommon values are captured by the next lower value
* in the table leading to a slight increase in packetization overhead.
* WSCALE: is necessary to allow large windows to be used for high delay-
* bandwidth product links. Not scaling the window when it was initially
* negotiated is bad for performance as lack of scaling further decreases
* the apparent available send window. We only need to encode the WSCALE
* we received from the remote end. Our end can be recalculated at any
* time. The common WSCALE values can be encoded in a 3-bit table.
* Uncommon values are captured by the next lower value in the table
* making us under-estimate the available window size halving our
* theoretically possible maximum throughput for that connection.
* SACK: Greatly assists in packet loss recovery and requires 1 bit.
* TIMESTAMP and SIGNATURE is not encoded because they are permanent options
* that are included in all segments on a connection. We enable them when
* the ACK has them.
*
* Security of syncookies and attack vectors:
*
* The MAC is computed over (faddr||laddr||fport||lport||irs||flags||secmod)
* together with the gloabl secret to make it unique per connection attempt.
* Thus any change of any of those parameters results in a different MAC output
* in an unpredictable way unless a collision is encountered. 24 bits of the
* MAC are embedded into the ISS.
*
* To prevent replay attacks two rotating global secrets are updated with a
* new random value every 15 seconds. The life-time of a syncookie is thus
* 15-30 seconds.
*
* Vector 1: Attacking the secret. This requires finding a weakness in the
* MAC itself or the way it is used here. The attacker can do a chosen plain
* text attack by varying and testing the all parameters under his control.
* The strength depends on the size and randomness of the secret, and the
* cryptographic security of the MAC function. Due to the constant updating
* of the secret the attacker has at most 29.999 seconds to find the secret
* and launch spoofed connections. After that he has to start all over again.
*
* Vector 2: Collision attack on the MAC of a single ACK. With a 24 bit MAC
* size an average of 4,823 attempts are required for a 50% chance of success
* to spoof a single syncookie (birthday collision paradox). However the
* attacker is blind and doesn't know if one of his attempts succeeded unless
* he has a side channel to interfere success from. A single connection setup
* success average of 90% requires 8,790 packets, 99.99% requires 17,578 packets.
* This many attempts are required for each one blind spoofed connection. For
* every additional spoofed connection he has to launch another N attempts.
* Thus for a sustained rate 100 spoofed connections per second approximately
* 1,800,000 packets per second would have to be sent.
*
* NB: The MAC function should be fast so that it doesn't become a CPU
* exhaustion attack vector itself.
*
* References:
* RFC4987 TCP SYN Flooding Attacks and Common Mitigations
* SYN cookies were first proposed by cryptographer Dan J. Bernstein in 1996
* http://cr.yp.to/syncookies.html (overview)
* http://cr.yp.to/syncookies/archive (details)
*
*
* Schematic construction of a syncookie enabled Initial Sequence Number:
* 0 1 2 3
* 12345678901234567890123456789012
* |xxxxxxxxxxxxxxxxxxxxxxxxWWWMMMSP|
*
* x 24 MAC (truncated)
* W 3 Send Window Scale index
* M 3 MSS index
* S 1 SACK permitted
* P 1 Odd/even secret
*/
/*
* Distribution and probability of certain MSS values. Those in between are
* rounded down to the next lower one.
* [An Analysis of TCP Maximum Segment Sizes, S. Alcock and R. Nelson, 2011]
* .2% .3% 5% 7% 7% 20% 15% 45%
*/
static int tcp_sc_msstab[] = { 216, 536, 1200, 1360, 1400, 1440, 1452, 1460 };
/*
* Distribution and probability of certain WSCALE values. We have to map the
* (send) window scale (shift) option with a range of 0-14 from 4 bits into 3
* bits based on prevalence of certain values. Where we don't have an exact
* match for are rounded down to the next lower one letting us under-estimate
* the true available window. At the moment this would happen only for the
* very uncommon values 3, 5 and those above 8 (more than 16MB socket buffer
* and window size). The absence of the WSCALE option (no scaling in either
* direction) is encoded with index zero.
* [WSCALE values histograms, Allman, 2012]
* X 10 10 35 5 6 14 10% by host
* X 11 4 5 5 18 49 3% by connections
*/
static int tcp_sc_wstab[] = { 0, 0, 1, 2, 4, 6, 7, 8 };
/*
* Compute the MAC for the SYN cookie. SIPHASH-2-4 is chosen for its speed
* and good cryptographic properties.
*/
static uint32_t
syncookie_mac(struct in_conninfo *inc, tcp_seq irs, uint8_t flags,
uint8_t *secbits, uintptr_t secmod)
{
SIPHASH_CTX ctx;
uint32_t siphash[2];
SipHash24_Init(&ctx);
SipHash_SetKey(&ctx, secbits);
switch (inc->inc_flags & INC_ISIPV6) {
#ifdef INET
case 0:
SipHash_Update(&ctx, &inc->inc_faddr, sizeof(inc->inc_faddr));
SipHash_Update(&ctx, &inc->inc_laddr, sizeof(inc->inc_laddr));
break;
#endif
#ifdef INET6
case INC_ISIPV6:
SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(inc->inc6_faddr));
SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(inc->inc6_laddr));
break;
#endif
}
SipHash_Update(&ctx, &inc->inc_fport, sizeof(inc->inc_fport));
SipHash_Update(&ctx, &inc->inc_lport, sizeof(inc->inc_lport));
SipHash_Update(&ctx, &irs, sizeof(irs));
SipHash_Update(&ctx, &flags, sizeof(flags));
SipHash_Update(&ctx, &secmod, sizeof(secmod));
SipHash_Final((u_int8_t *)&siphash, &ctx);
return (siphash[0] ^ siphash[1]);
}
static tcp_seq
syncookie_generate(struct syncache_head *sch, struct syncache *sc)
{
u_int i, secbit, wscale;
uint32_t iss, hash;
uint8_t *secbits;
union syncookie cookie;
cookie.cookie = 0;
/* Map our computed MSS into the 3-bit index. */
for (i = nitems(tcp_sc_msstab) - 1;
tcp_sc_msstab[i] > sc->sc_peer_mss && i > 0;
i--)
;
cookie.flags.mss_idx = i;
/*
* Map the send window scale into the 3-bit index but only if
* the wscale option was received.
*/
if (sc->sc_flags & SCF_WINSCALE) {
wscale = sc->sc_requested_s_scale;
for (i = nitems(tcp_sc_wstab) - 1;
tcp_sc_wstab[i] > wscale && i > 0;
i--)
;
cookie.flags.wscale_idx = i;
}
/* Can we do SACK? */
if (sc->sc_flags & SCF_SACK)
cookie.flags.sack_ok = 1;
/* Which of the two secrets to use. */
secbit = V_tcp_syncache.secret.oddeven & 0x1;
cookie.flags.odd_even = secbit;
secbits = V_tcp_syncache.secret.key[secbit];
hash = syncookie_mac(&sc->sc_inc, sc->sc_irs, cookie.cookie, secbits,
(uintptr_t)sch);
/*
* Put the flags into the hash and XOR them to get better ISS number
* variance. This doesn't enhance the cryptographic strength and is
* done to prevent the 8 cookie bits from showing up directly on the
* wire.
*/
iss = hash & ~0xff;
iss |= cookie.cookie ^ (hash >> 24);
TCPSTAT_INC(tcps_sc_sendcookie);
return (iss);
}
static bool
syncookie_expand(struct in_conninfo *inc, const struct syncache_head *sch,
struct syncache *sc, struct tcphdr *th, struct tcpopt *to,
struct socket *lso, uint16_t port)
{
uint32_t hash;
uint8_t *secbits;
tcp_seq ack, seq;
int wnd;
union syncookie cookie;
/*
* Pull information out of SYN-ACK/ACK and revert sequence number
* advances.
*/
ack = th->th_ack - 1;
seq = th->th_seq - 1;
/*
* Unpack the flags containing enough information to restore the
* connection.
*/
cookie.cookie = (ack & 0xff) ^ (ack >> 24);
/* Which of the two secrets to use. */
secbits = V_tcp_syncache.secret.key[cookie.flags.odd_even];
hash = syncookie_mac(inc, seq, cookie.cookie, secbits, (uintptr_t)sch);
/* The recomputed hash matches the ACK if this was a genuine cookie. */
if ((ack & ~0xff) != (hash & ~0xff))
return (false);
/* Fill in the syncache values. */
sc->sc_flags = 0;
bcopy(inc, &sc->sc_inc, sizeof(struct in_conninfo));
sc->sc_ipopts = NULL;
sc->sc_irs = seq;
sc->sc_iss = ack;
switch (inc->inc_flags & INC_ISIPV6) {
#ifdef INET
case 0:
sc->sc_ip_ttl = sotoinpcb(lso)->inp_ip_ttl;
sc->sc_ip_tos = sotoinpcb(lso)->inp_ip_tos;
break;
#endif
#ifdef INET6
case INC_ISIPV6:
if (sotoinpcb(lso)->inp_flags & IN6P_AUTOFLOWLABEL)
sc->sc_flowlabel =
htonl(sc->sc_iss) & IPV6_FLOWLABEL_MASK;
break;
#endif
}
sc->sc_peer_mss = tcp_sc_msstab[cookie.flags.mss_idx];
/* Only use wscale if it was enabled in the orignal SYN. */
if (cookie.flags.wscale_idx > 0) {
u_int wscale = 0;
/* Recompute the receive window scale that was sent earlier. */
while (wscale < TCP_MAX_WINSHIFT &&
(TCP_MAXWIN << wscale) < sb_max)
wscale++;
sc->sc_requested_r_scale = wscale;
sc->sc_requested_s_scale = tcp_sc_wstab[cookie.flags.wscale_idx];
sc->sc_flags |= SCF_WINSCALE;
}
wnd = lso->sol_sbrcv_hiwat;
wnd = imax(wnd, 0);
wnd = imin(wnd, TCP_MAXWIN);
sc->sc_wnd = wnd;
if (cookie.flags.sack_ok)
sc->sc_flags |= SCF_SACK;
if (to->to_flags & TOF_TS) {
sc->sc_flags |= SCF_TIMESTAMP;
sc->sc_tsreflect = to->to_tsval;
sc->sc_tsoff = tcp_new_ts_offset(inc);
}
if (to->to_flags & TOF_SIGNATURE)
sc->sc_flags |= SCF_SIGNATURE;
sc->sc_rxmits = 0;
sc->sc_port = port;
return (true);
}
#ifdef INVARIANTS
static void
syncookie_cmp(struct in_conninfo *inc, const struct syncache_head *sch,
struct syncache *sc, struct tcphdr *th, struct tcpopt *to,
struct socket *lso, uint16_t port)
{
struct syncache scs;
char *s;
bzero(&scs, sizeof(scs));
if (syncookie_expand(inc, sch, &scs, th, to, lso, port) &&
(sc->sc_peer_mss != scs.sc_peer_mss ||
sc->sc_requested_r_scale != scs.sc_requested_r_scale ||
sc->sc_requested_s_scale != scs.sc_requested_s_scale ||
(sc->sc_flags & SCF_SACK) != (scs.sc_flags & SCF_SACK))) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)) == NULL)
return;
if (sc->sc_peer_mss != scs.sc_peer_mss)
log(LOG_DEBUG, "%s; %s: mss different %i vs %i\n",
s, __func__, sc->sc_peer_mss, scs.sc_peer_mss);
if (sc->sc_requested_r_scale != scs.sc_requested_r_scale)
log(LOG_DEBUG, "%s; %s: rwscale different %i vs %i\n",
s, __func__, sc->sc_requested_r_scale,
scs.sc_requested_r_scale);
if (sc->sc_requested_s_scale != scs.sc_requested_s_scale)
log(LOG_DEBUG, "%s; %s: swscale different %i vs %i\n",
s, __func__, sc->sc_requested_s_scale,
scs.sc_requested_s_scale);
if ((sc->sc_flags & SCF_SACK) != (scs.sc_flags & SCF_SACK))
log(LOG_DEBUG, "%s; %s: SACK different\n", s, __func__);
free(s, M_TCPLOG);
}
}
#endif /* INVARIANTS */
static void
syncookie_reseed(void *arg)
{
struct tcp_syncache *sc = arg;
uint8_t *secbits;
int secbit;
/*
* Reseeding the secret doesn't have to be protected by a lock.
* It only must be ensured that the new random values are visible
* to all CPUs in a SMP environment. The atomic with release
* semantics ensures that.
*/
secbit = (sc->secret.oddeven & 0x1) ? 0 : 1;
secbits = sc->secret.key[secbit];
arc4rand(secbits, SYNCOOKIE_SECRET_SIZE, 0);
atomic_add_rel_int(&sc->secret.oddeven, 1);
/* Reschedule ourself. */
callout_schedule(&sc->secret.reseed, SYNCOOKIE_LIFETIME * hz);
}
/*
* We have overflowed a bucket. Let's pause dealing with the syncache.
* This function will increment the bucketoverflow statistics appropriately
* (once per pause when pausing is enabled; otherwise, once per overflow).
*/
static void
syncache_pause(struct in_conninfo *inc)
{
time_t delta;
const char *s;
/* XXX:
* 2. Add sysctl read here so we don't get the benefit of this
* change without the new sysctl.
*/
/*
* Try an unlocked read. If we already know that another thread
* has activated the feature, there is no need to proceed.
*/
if (V_tcp_syncache.paused)
return;
/* Are cookied enabled? If not, we can't pause. */
if (!V_tcp_syncookies) {
TCPSTAT_INC(tcps_sc_bucketoverflow);
return;
}
/*
* We may be the first thread to find an overflow. Get the lock
* and evaluate if we need to take action.
*/
mtx_lock(&V_tcp_syncache.pause_mtx);
if (V_tcp_syncache.paused) {
mtx_unlock(&V_tcp_syncache.pause_mtx);
return;
}
/* Activate protection. */
V_tcp_syncache.paused = true;
TCPSTAT_INC(tcps_sc_bucketoverflow);
/*
* Determine the last backoff time. If we are seeing a re-newed
* attack within that same time after last reactivating the syncache,
* consider it an extension of the same attack.
*/
delta = TCP_SYNCACHE_PAUSE_TIME << V_tcp_syncache.pause_backoff;
if (V_tcp_syncache.pause_until + delta - time_uptime > 0) {
if (V_tcp_syncache.pause_backoff < TCP_SYNCACHE_MAX_BACKOFF) {
delta <<= 1;
V_tcp_syncache.pause_backoff++;
}
} else {
delta = TCP_SYNCACHE_PAUSE_TIME;
V_tcp_syncache.pause_backoff = 0;
}
/* Log a warning, including IP addresses, if able. */
if (inc != NULL)
s = tcp_log_addrs(inc, NULL, NULL, NULL);
else
s = (const char *)NULL;
log(LOG_WARNING, "TCP syncache overflow detected; using syncookies for "
"the next %lld seconds%s%s%s\n", (long long)delta,
(s != NULL) ? " (last SYN: " : "", (s != NULL) ? s : "",
(s != NULL) ? ")" : "");
free(__DECONST(void *, s), M_TCPLOG);
/* Use the calculated delta to set a new pause time. */
V_tcp_syncache.pause_until = time_uptime + delta;
callout_reset(&V_tcp_syncache.pause_co, delta * hz, syncache_unpause,
&V_tcp_syncache);
mtx_unlock(&V_tcp_syncache.pause_mtx);
}
/* Evaluate whether we need to unpause. */
static void
syncache_unpause(void *arg)
{
struct tcp_syncache *sc;
time_t delta;
sc = arg;
mtx_assert(&sc->pause_mtx, MA_OWNED | MA_NOTRECURSED);
callout_deactivate(&sc->pause_co);
/*
* Check to make sure we are not running early. If the pause
* time has expired, then deactivate the protection.
*/
if ((delta = sc->pause_until - time_uptime) > 0)
callout_schedule(&sc->pause_co, delta * hz);
else
sc->paused = false;
}
/*
* Exports the syncache entries to userland so that netstat can display
* them alongside the other sockets. This function is intended to be
* called only from tcp_pcblist.
*
* Due to concurrency on an active system, the number of pcbs exported
* may have no relation to max_pcbs. max_pcbs merely indicates the
* amount of space the caller allocated for this function to use.
*/
int
syncache_pcblist(struct sysctl_req *req)
{
struct xtcpcb xt;
struct syncache *sc;
struct syncache_head *sch;
int error, i;
bzero(&xt, sizeof(xt));
xt.xt_len = sizeof(xt);
xt.t_state = TCPS_SYN_RECEIVED;
xt.xt_inp.xi_socket.xso_protocol = IPPROTO_TCP;
xt.xt_inp.xi_socket.xso_len = sizeof (struct xsocket);
xt.xt_inp.xi_socket.so_type = SOCK_STREAM;
xt.xt_inp.xi_socket.so_state = SS_ISCONNECTING;
for (i = 0; i < V_tcp_syncache.hashsize; i++) {
sch = &V_tcp_syncache.hashbase[i];
SCH_LOCK(sch);
TAILQ_FOREACH(sc, &sch->sch_bucket, sc_hash) {
if (sc->sc_cred != NULL &&
cr_cansee(req->td->td_ucred, sc->sc_cred) != 0)
continue;
if (sc->sc_inc.inc_flags & INC_ISIPV6)
xt.xt_inp.inp_vflag = INP_IPV6;
else
xt.xt_inp.inp_vflag = INP_IPV4;
xt.xt_encaps_port = sc->sc_port;
bcopy(&sc->sc_inc, &xt.xt_inp.inp_inc,
sizeof (struct in_conninfo));
error = SYSCTL_OUT(req, &xt, sizeof xt);
if (error) {
SCH_UNLOCK(sch);
return (0);
}
}
SCH_UNLOCK(sch);
}
return (0);
}
diff --git a/sys/netlink/netlink_domain.c b/sys/netlink/netlink_domain.c
index 74b46114716e..e906e0d635af 100644
--- a/sys/netlink/netlink_domain.c
+++ b/sys/netlink/netlink_domain.c
@@ -1,1002 +1,1008 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 Ng Peng Nam Sean
* Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
* Copyright (c) 2023 Gleb Smirnoff <glebius@FreeBSD.org>
*
* 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.
*/
/*
* This file contains socket and protocol bindings for netlink.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/domain.h>
#include <sys/jail.h>
#include <sys/mbuf.h>
#include <sys/osd.h>
#include <sys/protosw.h>
#include <sys/proc.h>
#include <sys/ck.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysent.h>
#include <sys/syslog.h>
#include <sys/priv.h>
#include <sys/uio.h>
#include <netlink/netlink.h>
#include <netlink/netlink_ctl.h>
#include <netlink/netlink_var.h>
#define DEBUG_MOD_NAME nl_domain
#define DEBUG_MAX_LEVEL LOG_DEBUG3
#include <netlink/netlink_debug.h>
_DECLARE_DEBUG(LOG_INFO);
_Static_assert((NLP_MAX_GROUPS % 64) == 0,
"NLP_MAX_GROUPS has to be multiple of 64");
_Static_assert(NLP_MAX_GROUPS >= 64,
"NLP_MAX_GROUPS has to be at least 64");
#define NLCTL_TRACKER struct rm_priotracker nl_tracker
#define NLCTL_RLOCK() rm_rlock(&V_nl_ctl.ctl_lock, &nl_tracker)
#define NLCTL_RUNLOCK() rm_runlock(&V_nl_ctl.ctl_lock, &nl_tracker)
#define NLCTL_LOCK_ASSERT() rm_assert(&V_nl_ctl.ctl_lock, RA_LOCKED)
#define NLCTL_WLOCK() rm_wlock(&V_nl_ctl.ctl_lock)
#define NLCTL_WUNLOCK() rm_wunlock(&V_nl_ctl.ctl_lock)
#define NLCTL_WLOCK_ASSERT() rm_assert(&V_nl_ctl.ctl_lock, RA_WLOCKED)
static u_long nl_sendspace = NLSNDQ;
SYSCTL_ULONG(_net_netlink, OID_AUTO, sendspace, CTLFLAG_RW, &nl_sendspace, 0,
"Default netlink socket send space");
static u_long nl_recvspace = NLSNDQ;
SYSCTL_ULONG(_net_netlink, OID_AUTO, recvspace, CTLFLAG_RW, &nl_recvspace, 0,
"Default netlink socket receive space");
extern u_long sb_max_adj;
static u_long nl_maxsockbuf = 512 * 1024 * 1024; /* 512M, XXX: init based on physmem */
static int sysctl_handle_nl_maxsockbuf(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_net_netlink, OID_AUTO, nl_maxsockbuf,
CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_MPSAFE, &nl_maxsockbuf, 0,
sysctl_handle_nl_maxsockbuf, "LU",
"Maximum Netlink socket buffer size");
static unsigned int osd_slot_id = 0;
void
nl_osd_register(void)
{
osd_slot_id = osd_register(OSD_THREAD, NULL, NULL);
}
void
nl_osd_unregister(void)
{
osd_deregister(OSD_THREAD, osd_slot_id);
}
struct nlpcb *
_nl_get_thread_nlp(struct thread *td)
{
return (osd_get(OSD_THREAD, &td->td_osd, osd_slot_id));
}
void
nl_set_thread_nlp(struct thread *td, struct nlpcb *nlp)
{
NLP_LOG(LOG_DEBUG2, nlp, "Set thread %p nlp to %p (slot %u)", td, nlp, osd_slot_id);
if (osd_set(OSD_THREAD, &td->td_osd, osd_slot_id, nlp) == 0)
return;
/* Failed, need to realloc */
void **rsv = osd_reserve(osd_slot_id);
osd_set_reserved(OSD_THREAD, &td->td_osd, osd_slot_id, rsv, nlp);
}
/*
* Looks up a nlpcb struct based on the @portid. Need to claim nlsock_mtx.
* Returns nlpcb pointer if present else NULL
*/
static struct nlpcb *
nl_port_lookup(uint32_t port_id)
{
struct nlpcb *nlp;
CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_port_head, nl_port_next) {
if (nlp->nl_port == port_id)
return (nlp);
}
return (NULL);
}
static void
nlp_join_group(struct nlpcb *nlp, unsigned int group_id)
{
MPASS(group_id < NLP_MAX_GROUPS);
NLCTL_WLOCK_ASSERT();
/* TODO: add family handler callback */
if (!nlp_unconstrained_vnet(nlp))
return;
BIT_SET(NLP_MAX_GROUPS, group_id, &nlp->nl_groups);
}
static void
nlp_leave_group(struct nlpcb *nlp, unsigned int group_id)
{
MPASS(group_id < NLP_MAX_GROUPS);
NLCTL_WLOCK_ASSERT();
BIT_CLR(NLP_MAX_GROUPS, group_id, &nlp->nl_groups);
}
static bool
nlp_memberof_group(struct nlpcb *nlp, unsigned int group_id)
{
MPASS(group_id < NLP_MAX_GROUPS);
NLCTL_LOCK_ASSERT();
return (BIT_ISSET(NLP_MAX_GROUPS, group_id, &nlp->nl_groups));
}
static uint32_t
nlp_get_groups_compat(struct nlpcb *nlp)
{
uint32_t groups_mask = 0;
NLCTL_LOCK_ASSERT();
for (int i = 0; i < 32; i++) {
if (nlp_memberof_group(nlp, i + 1))
groups_mask |= (1 << i);
}
return (groups_mask);
}
static struct nl_buf *
nl_buf_copy(struct nl_buf *nb)
{
struct nl_buf *copy;
copy = nl_buf_alloc(nb->buflen, M_NOWAIT);
if (__predict_false(copy == NULL))
return (NULL);
memcpy(copy, nb, sizeof(*nb) + nb->buflen);
return (copy);
}
/*
* Broadcasts in the writer's buffer.
*/
bool
nl_send_group(struct nl_writer *nw)
{
struct nl_buf *nb = nw->buf;
struct nlpcb *nlp_last = NULL;
struct nlpcb *nlp;
NLCTL_TRACKER;
IF_DEBUG_LEVEL(LOG_DEBUG2) {
struct nlmsghdr *hdr = (struct nlmsghdr *)nb->data;
NL_LOG(LOG_DEBUG2, "MCAST len %u msg type %d len %u to group %d/%d",
nb->datalen, hdr->nlmsg_type, hdr->nlmsg_len,
nw->group.proto, nw->group.id);
}
nw->buf = NULL;
NLCTL_RLOCK();
CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_pcb_head, nl_next) {
if ((nw->group.priv == 0 || priv_check_cred(
nlp->nl_socket->so_cred, nw->group.priv) == 0) &&
nlp->nl_proto == nw->group.proto &&
nlp_memberof_group(nlp, nw->group.id)) {
if (nlp_last != NULL) {
struct nl_buf *copy;
copy = nl_buf_copy(nb);
if (copy != NULL) {
nw->buf = copy;
(void)nl_send(nw, nlp_last);
} else {
NLP_LOCK(nlp_last);
if (nlp_last->nl_socket != NULL)
sorwakeup(nlp_last->nl_socket);
NLP_UNLOCK(nlp_last);
}
}
nlp_last = nlp;
}
}
if (nlp_last != NULL) {
nw->buf = nb;
(void)nl_send(nw, nlp_last);
} else
nl_buf_free(nb);
NLCTL_RUNLOCK();
return (true);
}
void
nl_clear_group(u_int group)
{
struct nlpcb *nlp;
NLCTL_WLOCK();
CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_pcb_head, nl_next)
if (nlp_memberof_group(nlp, group))
nlp_leave_group(nlp, group);
NLCTL_WUNLOCK();
}
static uint32_t
nl_find_port(void)
{
/*
* app can open multiple netlink sockets.
* Start with current pid, if already taken,
* try random numbers in 65k..256k+65k space,
* avoiding clash with pids.
*/
if (nl_port_lookup(curproc->p_pid) == NULL)
return (curproc->p_pid);
for (int i = 0; i < 16; i++) {
uint32_t nl_port = (arc4random() % 65536) + 65536 * 4;
if (nl_port_lookup(nl_port) == 0)
return (nl_port);
NL_LOG(LOG_DEBUG3, "tried %u\n", nl_port);
}
return (curproc->p_pid);
}
static int
nl_bind_locked(struct nlpcb *nlp, struct sockaddr_nl *snl)
{
if (nlp->nl_bound) {
if (nlp->nl_port != snl->nl_pid) {
NL_LOG(LOG_DEBUG,
"bind() failed: program pid %d "
"is different from provided pid %d",
nlp->nl_port, snl->nl_pid);
return (EINVAL); // XXX: better error
}
} else {
if (snl->nl_pid == 0)
snl->nl_pid = nl_find_port();
if (nl_port_lookup(snl->nl_pid) != NULL)
return (EADDRINUSE);
nlp->nl_port = snl->nl_pid;
nlp->nl_bound = true;
CK_LIST_INSERT_HEAD(&V_nl_ctl.ctl_port_head, nlp, nl_port_next);
}
for (int i = 0; i < 32; i++) {
if (snl->nl_groups & ((uint32_t)1 << i))
nlp_join_group(nlp, i + 1);
else
nlp_leave_group(nlp, i + 1);
}
return (0);
}
static int
nl_attach(struct socket *so, int proto, struct thread *td)
{
struct nlpcb *nlp;
int error;
if (__predict_false(netlink_unloading != 0))
return (EAFNOSUPPORT);
error = nl_verify_proto(proto);
if (error != 0)
return (error);
bool is_linux = SV_PROC_ABI(td->td_proc) == SV_ABI_LINUX;
NL_LOG(LOG_DEBUG2, "socket %p, %sPID %d: attaching socket to %s",
so, is_linux ? "(linux) " : "", curproc->p_pid,
nl_get_proto_name(proto));
- nlp = malloc(sizeof(struct nlpcb), M_PCB, M_WAITOK | M_ZERO);
+ mtx_init(&so->so_snd_mtx, "netlink so_snd", NULL, MTX_DEF);
+ mtx_init(&so->so_rcv_mtx, "netlink so_rcv", NULL, MTX_DEF);
error = soreserve(so, nl_sendspace, nl_recvspace);
if (error != 0) {
- free(nlp, M_PCB);
+ mtx_destroy(&so->so_snd_mtx);
+ mtx_destroy(&so->so_rcv_mtx);
return (error);
}
TAILQ_INIT(&so->so_rcv.nl_queue);
TAILQ_INIT(&so->so_snd.nl_queue);
+ nlp = malloc(sizeof(struct nlpcb), M_PCB, M_WAITOK | M_ZERO);
so->so_pcb = nlp;
nlp->nl_socket = so;
nlp->nl_proto = proto;
nlp->nl_process_id = curproc->p_pid;
nlp->nl_linux = is_linux;
nlp->nl_unconstrained_vnet = !jailed_without_vnet(so->so_cred);
nlp->nl_need_thread_setup = true;
NLP_LOCK_INIT(nlp);
refcount_init(&nlp->nl_refcount, 1);
nlp->nl_taskqueue = taskqueue_create("netlink_socket", M_WAITOK,
taskqueue_thread_enqueue, &nlp->nl_taskqueue);
TASK_INIT(&nlp->nl_task, 0, nl_taskqueue_handler, nlp);
taskqueue_start_threads(&nlp->nl_taskqueue, 1, PWAIT,
"netlink_socket (PID %u)", nlp->nl_process_id);
NLCTL_WLOCK();
CK_LIST_INSERT_HEAD(&V_nl_ctl.ctl_pcb_head, nlp, nl_next);
NLCTL_WUNLOCK();
soisconnected(so);
return (0);
}
static int
nl_bind(struct socket *so, struct sockaddr *sa, struct thread *td)
{
struct nlpcb *nlp = sotonlpcb(so);
struct sockaddr_nl *snl = (struct sockaddr_nl *)sa;
int error;
NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid);
if (snl->nl_len != sizeof(*snl)) {
NL_LOG(LOG_DEBUG, "socket %p, wrong sizeof(), ignoring bind()", so);
return (EINVAL);
}
NLCTL_WLOCK();
NLP_LOCK(nlp);
error = nl_bind_locked(nlp, snl);
NLP_UNLOCK(nlp);
NLCTL_WUNLOCK();
NL_LOG(LOG_DEBUG2, "socket %p, bind() to %u, groups %u, error %d", so,
snl->nl_pid, snl->nl_groups, error);
return (error);
}
static int
nl_assign_port(struct nlpcb *nlp, uint32_t port_id)
{
struct sockaddr_nl snl = {
.nl_pid = port_id,
};
int error;
NLCTL_WLOCK();
NLP_LOCK(nlp);
snl.nl_groups = nlp_get_groups_compat(nlp);
error = nl_bind_locked(nlp, &snl);
NLP_UNLOCK(nlp);
NLCTL_WUNLOCK();
NL_LOG(LOG_DEBUG3, "socket %p, port assign: %d, error: %d", nlp->nl_socket, port_id, error);
return (error);
}
/*
* nl_autobind_port binds a unused portid to @nlp
* @nlp: pcb data for the netlink socket
* @candidate_id: first id to consider
*/
static int
nl_autobind_port(struct nlpcb *nlp, uint32_t candidate_id)
{
uint32_t port_id = candidate_id;
NLCTL_TRACKER;
bool exist;
int error = EADDRINUSE;
for (int i = 0; i < 10; i++) {
NL_LOG(LOG_DEBUG3, "socket %p, trying to assign port %d", nlp->nl_socket, port_id);
NLCTL_RLOCK();
exist = nl_port_lookup(port_id) != 0;
NLCTL_RUNLOCK();
if (!exist) {
error = nl_assign_port(nlp, port_id);
if (error != EADDRINUSE)
break;
}
port_id++;
}
NL_LOG(LOG_DEBUG3, "socket %p, autobind to %d, error: %d", nlp->nl_socket, port_id, error);
return (error);
}
static int
nl_connect(struct socket *so, struct sockaddr *sa, struct thread *td)
{
struct sockaddr_nl *snl = (struct sockaddr_nl *)sa;
struct nlpcb *nlp;
NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid);
if (snl->nl_len != sizeof(*snl)) {
NL_LOG(LOG_DEBUG, "socket %p, wrong sizeof(), ignoring bind()", so);
return (EINVAL);
}
nlp = sotonlpcb(so);
if (!nlp->nl_bound) {
int error = nl_autobind_port(nlp, td->td_proc->p_pid);
if (error != 0) {
NL_LOG(LOG_DEBUG, "socket %p, nl_autobind() failed: %d", so, error);
return (error);
}
}
/* XXX: Handle socket flags & multicast */
soisconnected(so);
NL_LOG(LOG_DEBUG2, "socket %p, connect to %u", so, snl->nl_pid);
return (0);
}
static void
destroy_nlpcb_epoch(epoch_context_t ctx)
{
struct nlpcb *nlp;
nlp = __containerof(ctx, struct nlpcb, nl_epoch_ctx);
NLP_LOCK_DESTROY(nlp);
free(nlp, M_PCB);
}
static void
nl_close(struct socket *so)
{
MPASS(sotonlpcb(so) != NULL);
struct nlpcb *nlp;
struct nl_buf *nb;
NL_LOG(LOG_DEBUG2, "detaching socket %p, PID %d", so, curproc->p_pid);
nlp = sotonlpcb(so);
/* Mark as inactive so no new work can be enqueued */
NLP_LOCK(nlp);
bool was_bound = nlp->nl_bound;
NLP_UNLOCK(nlp);
/* Wait till all scheduled work has been completed */
taskqueue_drain_all(nlp->nl_taskqueue);
taskqueue_free(nlp->nl_taskqueue);
NLCTL_WLOCK();
NLP_LOCK(nlp);
if (was_bound) {
CK_LIST_REMOVE(nlp, nl_port_next);
NL_LOG(LOG_DEBUG3, "socket %p, unlinking bound pid %u", so, nlp->nl_port);
}
CK_LIST_REMOVE(nlp, nl_next);
nlp->nl_socket = NULL;
NLP_UNLOCK(nlp);
NLCTL_WUNLOCK();
so->so_pcb = NULL;
while ((nb = TAILQ_FIRST(&so->so_snd.nl_queue)) != NULL) {
TAILQ_REMOVE(&so->so_snd.nl_queue, nb, tailq);
nl_buf_free(nb);
}
while ((nb = TAILQ_FIRST(&so->so_rcv.nl_queue)) != NULL) {
TAILQ_REMOVE(&so->so_rcv.nl_queue, nb, tailq);
nl_buf_free(nb);
}
+ mtx_destroy(&so->so_snd_mtx);
+ mtx_destroy(&so->so_rcv_mtx);
+
NL_LOG(LOG_DEBUG3, "socket %p, detached", so);
/* XXX: is delayed free needed? */
NET_EPOCH_CALL(destroy_nlpcb_epoch, &nlp->nl_epoch_ctx);
}
static int
nl_disconnect(struct socket *so)
{
NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid);
MPASS(sotonlpcb(so) != NULL);
return (ENOTCONN);
}
static int
nl_sockaddr(struct socket *so, struct sockaddr *sa)
{
*(struct sockaddr_nl *)sa = (struct sockaddr_nl ){
/* TODO: set other fields */
.nl_len = sizeof(struct sockaddr_nl),
.nl_family = AF_NETLINK,
.nl_pid = sotonlpcb(so)->nl_port,
};
return (0);
}
static int
nl_sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *m, struct mbuf *control, int flags, struct thread *td)
{
struct nlpcb *nlp = sotonlpcb(so);
struct sockbuf *sb = &so->so_snd;
struct nl_buf *nb;
size_t len;
int error;
MPASS(m == NULL && uio != NULL);
if (__predict_false(control != NULL)) {
m_freem(control);
return (EINVAL);
}
if (__predict_false(flags & MSG_OOB)) /* XXXGL: or just ignore? */
return (EOPNOTSUPP);
if (__predict_false(uio->uio_resid < sizeof(struct nlmsghdr)))
return (ENOBUFS); /* XXXGL: any better error? */
if (__predict_false(uio->uio_resid > sb->sb_hiwat))
return (EMSGSIZE);
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
if (error)
return (error);
len = roundup2(uio->uio_resid, 8) + SCRATCH_BUFFER_SIZE;
if (nlp->nl_linux)
len += roundup2(uio->uio_resid, 8);
nb = nl_buf_alloc(len, M_WAITOK);
nb->datalen = uio->uio_resid;
error = uiomove(&nb->data[0], uio->uio_resid, uio);
if (__predict_false(error))
goto out;
NL_LOG(LOG_DEBUG2, "sending message to kernel %u bytes", nb->datalen);
SOCK_SENDBUF_LOCK(so);
restart:
if (sb->sb_hiwat - sb->sb_ccc >= nb->datalen) {
TAILQ_INSERT_TAIL(&sb->nl_queue, nb, tailq);
sb->sb_acc += nb->datalen;
sb->sb_ccc += nb->datalen;
nb = NULL;
} else if ((so->so_state & SS_NBIO) ||
(flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) {
SOCK_SENDBUF_UNLOCK(so);
error = EWOULDBLOCK;
goto out;
} else {
if ((error = sbwait(so, SO_SND)) != 0) {
SOCK_SENDBUF_UNLOCK(so);
goto out;
} else
goto restart;
}
SOCK_SENDBUF_UNLOCK(so);
if (nb == NULL) {
NL_LOG(LOG_DEBUG3, "success");
NLP_LOCK(nlp);
nl_schedule_taskqueue(nlp);
NLP_UNLOCK(nlp);
}
out:
SOCK_IO_SEND_UNLOCK(so);
if (nb != NULL) {
NL_LOG(LOG_DEBUG3, "failure, error %d", error);
nl_buf_free(nb);
}
return (error);
}
/* Create control data for recvmsg(2) on Netlink socket. */
static struct mbuf *
nl_createcontrol(struct nlpcb *nlp)
{
struct {
struct nlattr nla;
uint32_t val;
} data[] = {
{
.nla.nla_len = sizeof(struct nlattr) + sizeof(uint32_t),
.nla.nla_type = NLMSGINFO_ATTR_PROCESS_ID,
.val = nlp->nl_process_id,
},
{
.nla.nla_len = sizeof(struct nlattr) + sizeof(uint32_t),
.nla.nla_type = NLMSGINFO_ATTR_PORT_ID,
.val = nlp->nl_port,
},
};
return (sbcreatecontrol(data, sizeof(data), NETLINK_MSG_INFO,
SOL_NETLINK, M_WAITOK));
}
static int
nl_soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp, struct mbuf **controlp, int *flagsp)
{
static const struct sockaddr_nl nl_empty_src = {
.nl_len = sizeof(struct sockaddr_nl),
.nl_family = PF_NETLINK,
.nl_pid = 0 /* comes from the kernel */
};
struct sockbuf *sb = &so->so_rcv;
struct nlpcb *nlp = sotonlpcb(so);
struct nl_buf *first, *last, *nb, *next;
struct nlmsghdr *hdr;
int flags, error;
u_int len, overflow, partoff, partlen, msgrcv, datalen;
bool nonblock, trunc, peek;
MPASS(mp == NULL && uio != NULL);
NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid);
if (psa != NULL)
*psa = sodupsockaddr((const struct sockaddr *)&nl_empty_src,
M_WAITOK);
if (controlp != NULL && (nlp->nl_flags & NLF_MSG_INFO))
*controlp = nl_createcontrol(nlp);
flags = flagsp != NULL ? *flagsp & ~MSG_TRUNC : 0;
trunc = flagsp != NULL ? *flagsp & MSG_TRUNC : false;
nonblock = (so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT | MSG_NBIO));
peek = flags & MSG_PEEK;
error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
if (__predict_false(error))
return (error);
len = 0;
overflow = 0;
msgrcv = 0;
datalen = 0;
SOCK_RECVBUF_LOCK(so);
while ((first = TAILQ_FIRST(&sb->nl_queue)) == NULL) {
if (nonblock) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (EWOULDBLOCK);
}
error = sbwait(so, SO_RCV);
if (error) {
SOCK_RECVBUF_UNLOCK(so);
SOCK_IO_RECV_UNLOCK(so);
return (error);
}
}
/*
* Netlink socket buffer consists of a queue of nl_bufs, but for the
* userland there should be no boundaries. However, there are Netlink
* messages, that shouldn't be split. Internal invariant is that a
* message never spans two nl_bufs.
* If a large userland buffer is provided, we would traverse the queue
* until either queue end is reached or the buffer is fulfilled. If
* an application provides a buffer that isn't able to fit a single
* message, we would truncate it and lose its tail. This is the only
* condition where we would lose data. If buffer is able to fit at
* least one message, we would return it and won't truncate the next.
*
* We use same code for normal and MSG_PEEK case. At first queue pass
* we scan nl_bufs and count lenght. In case we can read entire buffer
* at one write everything is trivial. In case we can not, we save
* pointer to the last (or partial) nl_buf and in the !peek case we
* split the queue into two pieces. We can safely drop the queue lock,
* as kernel would only append nl_bufs to the end of the queue, and
* we are the exclusive owner of queue beginning due to sleepable lock.
* At the second pass we copy data out and in !peek case free nl_bufs.
*/
TAILQ_FOREACH(nb, &sb->nl_queue, tailq) {
u_int offset;
MPASS(nb->offset < nb->datalen);
offset = nb->offset;
while (offset < nb->datalen) {
hdr = (struct nlmsghdr *)&nb->data[offset];
MPASS(nb->offset + hdr->nlmsg_len <= nb->datalen);
if (uio->uio_resid < len + hdr->nlmsg_len) {
overflow = len + hdr->nlmsg_len -
uio->uio_resid;
partoff = nb->offset;
if (offset > partoff) {
partlen = offset - partoff;
if (!peek) {
nb->offset = offset;
datalen += partlen;
}
} else if (len == 0 && uio->uio_resid > 0) {
flags |= MSG_TRUNC;
partlen = uio->uio_resid;
if (peek)
goto nospace;
datalen += hdr->nlmsg_len;
if (nb->offset + hdr->nlmsg_len ==
nb->datalen) {
/*
* Avoid leaving empty nb.
* Process last nb normally.
* Trust uiomove() to care
* about negative uio_resid.
*/
nb = TAILQ_NEXT(nb, tailq);
overflow = 0;
partlen = 0;
} else
nb->offset += hdr->nlmsg_len;
msgrcv++;
} else
partlen = 0;
goto nospace;
}
len += hdr->nlmsg_len;
offset += hdr->nlmsg_len;
MPASS(offset <= nb->buflen);
msgrcv++;
}
MPASS(offset == nb->datalen);
datalen += nb->datalen - nb->offset;
}
nospace:
last = nb;
if (!peek) {
if (last == NULL)
TAILQ_INIT(&sb->nl_queue);
else {
/* XXXGL: create TAILQ_SPLIT */
TAILQ_FIRST(&sb->nl_queue) = last;
last->tailq.tqe_prev = &TAILQ_FIRST(&sb->nl_queue);
}
MPASS(sb->sb_acc >= datalen);
sb->sb_acc -= datalen;
sb->sb_ccc -= datalen;
}
SOCK_RECVBUF_UNLOCK(so);
for (nb = first; nb != last; nb = next) {
next = TAILQ_NEXT(nb, tailq);
if (__predict_true(error == 0))
error = uiomove(&nb->data[nb->offset],
(int)(nb->datalen - nb->offset), uio);
if (!peek)
nl_buf_free(nb);
}
if (last != NULL && partlen > 0 && __predict_true(error == 0))
error = uiomove(&nb->data[partoff], (int)partlen, uio);
if (trunc && overflow > 0) {
uio->uio_resid -= overflow;
MPASS(uio->uio_resid < 0);
} else
MPASS(uio->uio_resid >= 0);
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv += msgrcv;
if (flagsp != NULL)
*flagsp |= flags;
SOCK_IO_RECV_UNLOCK(so);
nl_on_transmit(sotonlpcb(so));
return (error);
}
static int
nl_getoptflag(int sopt_name)
{
switch (sopt_name) {
case NETLINK_CAP_ACK:
return (NLF_CAP_ACK);
case NETLINK_EXT_ACK:
return (NLF_EXT_ACK);
case NETLINK_GET_STRICT_CHK:
return (NLF_STRICT);
case NETLINK_MSG_INFO:
return (NLF_MSG_INFO);
}
return (0);
}
static int
nl_ctloutput(struct socket *so, struct sockopt *sopt)
{
struct nlpcb *nlp = sotonlpcb(so);
uint32_t flag;
int optval, error = 0;
NLCTL_TRACKER;
NL_LOG(LOG_DEBUG2, "%ssockopt(%p, %d)", (sopt->sopt_dir) ? "set" : "get",
so, sopt->sopt_name);
switch (sopt->sopt_dir) {
case SOPT_SET:
switch (sopt->sopt_name) {
case NETLINK_ADD_MEMBERSHIP:
case NETLINK_DROP_MEMBERSHIP:
error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
if (error != 0)
break;
if (optval <= 0 || optval >= NLP_MAX_GROUPS) {
error = ERANGE;
break;
}
NL_LOG(LOG_DEBUG2, "ADD/DEL group %d", (uint32_t)optval);
NLCTL_WLOCK();
if (sopt->sopt_name == NETLINK_ADD_MEMBERSHIP)
nlp_join_group(nlp, optval);
else
nlp_leave_group(nlp, optval);
NLCTL_WUNLOCK();
break;
case NETLINK_CAP_ACK:
case NETLINK_EXT_ACK:
case NETLINK_GET_STRICT_CHK:
case NETLINK_MSG_INFO:
error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
if (error != 0)
break;
flag = nl_getoptflag(sopt->sopt_name);
if ((flag == NLF_MSG_INFO) && nlp->nl_linux) {
error = EINVAL;
break;
}
NLCTL_WLOCK();
if (optval != 0)
nlp->nl_flags |= flag;
else
nlp->nl_flags &= ~flag;
NLCTL_WUNLOCK();
break;
default:
error = ENOPROTOOPT;
}
break;
case SOPT_GET:
switch (sopt->sopt_name) {
case NETLINK_LIST_MEMBERSHIPS:
NLCTL_RLOCK();
optval = nlp_get_groups_compat(nlp);
NLCTL_RUNLOCK();
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
case NETLINK_CAP_ACK:
case NETLINK_EXT_ACK:
case NETLINK_GET_STRICT_CHK:
case NETLINK_MSG_INFO:
NLCTL_RLOCK();
optval = (nlp->nl_flags & nl_getoptflag(sopt->sopt_name)) != 0;
NLCTL_RUNLOCK();
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
default:
error = ENOPROTOOPT;
}
break;
default:
error = ENOPROTOOPT;
}
return (error);
}
static int
sysctl_handle_nl_maxsockbuf(SYSCTL_HANDLER_ARGS)
{
int error = 0;
u_long tmp_maxsockbuf = nl_maxsockbuf;
error = sysctl_handle_long(oidp, &tmp_maxsockbuf, arg2, req);
if (error || !req->newptr)
return (error);
if (tmp_maxsockbuf < MSIZE + MCLBYTES)
return (EINVAL);
nl_maxsockbuf = tmp_maxsockbuf;
return (0);
}
static int
nl_setsbopt(struct socket *so, struct sockopt *sopt)
{
int error, optval;
bool result;
if (sopt->sopt_name != SO_RCVBUF)
return (sbsetopt(so, sopt));
/* Allow to override max buffer size in certain conditions */
error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
if (error != 0)
return (error);
NL_LOG(LOG_DEBUG2, "socket %p, PID %d, SO_RCVBUF=%d", so, curproc->p_pid, optval);
if (optval > sb_max_adj) {
if (priv_check(curthread, PRIV_NET_ROUTE) != 0)
return (EPERM);
}
SOCK_RECVBUF_LOCK(so);
result = sbreserve_locked_limit(so, SO_RCV, optval, nl_maxsockbuf, curthread);
SOCK_RECVBUF_UNLOCK(so);
return (result ? 0 : ENOBUFS);
}
#define NETLINK_PROTOSW \
.pr_flags = PR_ATOMIC | PR_ADDR | PR_SOCKBUF, \
.pr_ctloutput = nl_ctloutput, \
.pr_setsbopt = nl_setsbopt, \
.pr_attach = nl_attach, \
.pr_bind = nl_bind, \
.pr_connect = nl_connect, \
.pr_disconnect = nl_disconnect, \
.pr_sosend = nl_sosend, \
.pr_soreceive = nl_soreceive, \
.pr_sockaddr = nl_sockaddr, \
.pr_close = nl_close
static struct protosw netlink_raw_sw = {
.pr_type = SOCK_RAW,
NETLINK_PROTOSW
};
static struct protosw netlink_dgram_sw = {
.pr_type = SOCK_DGRAM,
NETLINK_PROTOSW
};
static struct domain netlinkdomain = {
.dom_family = PF_NETLINK,
.dom_name = "netlink",
.dom_flags = DOMF_UNLOADABLE,
.dom_nprotosw = 2,
.dom_protosw = { &netlink_raw_sw, &netlink_dgram_sw },
};
DOMAIN_SET(netlink);

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