2 * NET4: Implementation of BSD Unix domain sockets.
4 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 * Linus Torvalds : Assorted bug cures.
13 * Niibe Yutaka : async I/O support.
14 * Carsten Paeth : PF_UNIX check, address fixes.
15 * Alan Cox : Limit size of allocated blocks.
16 * Alan Cox : Fixed the stupid socketpair bug.
17 * Alan Cox : BSD compatibility fine tuning.
18 * Alan Cox : Fixed a bug in connect when interrupted.
19 * Alan Cox : Sorted out a proper draft version of
20 * file descriptor passing hacked up from
22 * Marty Leisner : Fixes to fd passing
23 * Nick Nevin : recvmsg bugfix.
24 * Alan Cox : Started proper garbage collector
25 * Heiko EiBfeldt : Missing verify_area check
26 * Alan Cox : Started POSIXisms
27 * Andreas Schwab : Replace inode by dentry for proper
29 * Kirk Petersen : Made this a module
30 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
32 * Alexey Kuznetosv : Repaired (I hope) bugs introduces
33 * by above two patches.
34 * Andrea Arcangeli : If possible we block in connect(2)
35 * if the max backlog of the listen socket
36 * is been reached. This won't break
37 * old apps and it will avoid huge amount
38 * of socks hashed (this for unix_gc()
39 * performances reasons).
40 * Security fix that limits the max
41 * number of socks to 2*max_files and
42 * the number of skb queueable in the
44 * Artur Skawina : Hash function optimizations
45 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
46 * Malcolm Beattie : Set peercred for socketpair
47 * Michal Ostrowski : Module initialization cleanup.
48 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
49 * the core infrastructure is doing that
50 * for all net proto families now (2.5.69+)
53 * Known differences from reference BSD that was tested:
56 * ECONNREFUSED is not returned from one end of a connected() socket to the
57 * other the moment one end closes.
58 * fstat() doesn't return st_dev=0, and give the blksize as high water mark
59 * and a fake inode identifier (nor the BSD first socket fstat twice bug).
61 * accept() returns a path name even if the connecting socket has closed
62 * in the meantime (BSD loses the path and gives up).
63 * accept() returns 0 length path for an unbound connector. BSD returns 16
64 * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
65 * socketpair(...SOCK_RAW..) doesn't panic the kernel.
66 * BSD af_unix apparently has connect forgetting to block properly.
67 * (need to check this with the POSIX spec in detail)
69 * Differences from 2.0.0-11-... (ANK)
70 * Bug fixes and improvements.
71 * - client shutdown killed server socket.
72 * - removed all useless cli/sti pairs.
74 * Semantic changes/extensions.
75 * - generic control message passing.
76 * - SCM_CREDENTIALS control message.
77 * - "Abstract" (not FS based) socket bindings.
78 * Abstract names are sequences of bytes (not zero terminated)
79 * started by 0, so that this name space does not intersect
83 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
85 #include <linux/module.h>
86 #include <linux/kernel.h>
87 #include <linux/signal.h>
88 #include <linux/sched/signal.h>
89 #include <linux/errno.h>
90 #include <linux/string.h>
91 #include <linux/stat.h>
92 #include <linux/dcache.h>
93 #include <linux/namei.h>
94 #include <linux/socket.h>
96 #include <linux/fcntl.h>
97 #include <linux/termios.h>
98 #include <linux/sockios.h>
99 #include <linux/net.h>
100 #include <linux/in.h>
101 #include <linux/fs.h>
102 #include <linux/slab.h>
103 #include <linux/uaccess.h>
104 #include <linux/skbuff.h>
105 #include <linux/netdevice.h>
106 #include <net/net_namespace.h>
107 #include <net/sock.h>
108 #include <net/tcp_states.h>
109 #include <net/af_unix.h>
110 #include <linux/proc_fs.h>
111 #include <linux/seq_file.h>
113 #include <linux/init.h>
114 #include <linux/poll.h>
115 #include <linux/rtnetlink.h>
116 #include <linux/mount.h>
117 #include <net/checksum.h>
118 #include <linux/security.h>
119 #include <linux/freezer.h>
120 #include <linux/file.h>
122 struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
123 EXPORT_SYMBOL_GPL(unix_socket_table);
124 DEFINE_SPINLOCK(unix_table_lock);
125 EXPORT_SYMBOL_GPL(unix_table_lock);
126 static atomic_long_t unix_nr_socks;
129 static struct hlist_head *unix_sockets_unbound(void *addr)
131 unsigned long hash = (unsigned long)addr;
135 hash %= UNIX_HASH_SIZE;
136 return &unix_socket_table[UNIX_HASH_SIZE + hash];
139 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE)
141 #ifdef CONFIG_SECURITY_NETWORK
142 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
144 UNIXCB(skb).secid = scm->secid;
147 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
149 scm->secid = UNIXCB(skb).secid;
152 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
154 return (scm->secid == UNIXCB(skb).secid);
157 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
160 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
163 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
167 #endif /* CONFIG_SECURITY_NETWORK */
170 * SMP locking strategy:
171 * hash table is protected with spinlock unix_table_lock
172 * each socket state is protected by separate spin lock.
175 static inline unsigned int unix_hash_fold(__wsum n)
177 unsigned int hash = (__force unsigned int)csum_fold(n);
180 return hash&(UNIX_HASH_SIZE-1);
183 #define unix_peer(sk) (unix_sk(sk)->peer)
185 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
187 return unix_peer(osk) == sk;
190 static inline int unix_may_send(struct sock *sk, struct sock *osk)
192 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
195 static inline int unix_recvq_full(struct sock const *sk)
197 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
200 struct sock *unix_peer_get(struct sock *s)
208 unix_state_unlock(s);
211 EXPORT_SYMBOL_GPL(unix_peer_get);
213 static inline void unix_release_addr(struct unix_address *addr)
215 if (refcount_dec_and_test(&addr->refcnt))
220 * Check unix socket name:
221 * - should be not zero length.
222 * - if started by not zero, should be NULL terminated (FS object)
223 * - if started by zero, it is abstract name.
226 static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp)
230 if (len <= sizeof(short) || len > sizeof(*sunaddr))
232 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
234 if (sunaddr->sun_path[0]) {
236 * This may look like an off by one error but it is a bit more
237 * subtle. 108 is the longest valid AF_UNIX path for a binding.
238 * sun_path[108] doesn't as such exist. However in kernel space
239 * we are guaranteed that it is a valid memory location in our
240 * kernel address buffer.
242 ((char *)sunaddr)[len] = 0;
243 len = strlen(sunaddr->sun_path)+1+sizeof(short);
247 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
251 static void __unix_remove_socket(struct sock *sk)
253 sk_del_node_init(sk);
256 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
258 WARN_ON(!sk_unhashed(sk));
259 sk_add_node(sk, list);
262 static inline void unix_remove_socket(struct sock *sk)
264 spin_lock(&unix_table_lock);
265 __unix_remove_socket(sk);
266 spin_unlock(&unix_table_lock);
269 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
271 spin_lock(&unix_table_lock);
272 __unix_insert_socket(list, sk);
273 spin_unlock(&unix_table_lock);
276 static struct sock *__unix_find_socket_byname(struct net *net,
277 struct sockaddr_un *sunname,
278 int len, int type, unsigned int hash)
282 sk_for_each(s, &unix_socket_table[hash ^ type]) {
283 struct unix_sock *u = unix_sk(s);
285 if (!net_eq(sock_net(s), net))
288 if (u->addr->len == len &&
289 !memcmp(u->addr->name, sunname, len))
297 static inline struct sock *unix_find_socket_byname(struct net *net,
298 struct sockaddr_un *sunname,
304 spin_lock(&unix_table_lock);
305 s = __unix_find_socket_byname(net, sunname, len, type, hash);
308 spin_unlock(&unix_table_lock);
312 static struct sock *unix_find_socket_byinode(struct inode *i)
316 spin_lock(&unix_table_lock);
318 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
319 struct dentry *dentry = unix_sk(s)->path.dentry;
321 if (dentry && d_backing_inode(dentry) == i) {
328 spin_unlock(&unix_table_lock);
332 /* Support code for asymmetrically connected dgram sockets
334 * If a datagram socket is connected to a socket not itself connected
335 * to the first socket (eg, /dev/log), clients may only enqueue more
336 * messages if the present receive queue of the server socket is not
337 * "too large". This means there's a second writeability condition
338 * poll and sendmsg need to test. The dgram recv code will do a wake
339 * up on the peer_wait wait queue of a socket upon reception of a
340 * datagram which needs to be propagated to sleeping would-be writers
341 * since these might not have sent anything so far. This can't be
342 * accomplished via poll_wait because the lifetime of the server
343 * socket might be less than that of its clients if these break their
344 * association with it or if the server socket is closed while clients
345 * are still connected to it and there's no way to inform "a polling
346 * implementation" that it should let go of a certain wait queue
348 * In order to propagate a wake up, a wait_queue_entry_t of the client
349 * socket is enqueued on the peer_wait queue of the server socket
350 * whose wake function does a wake_up on the ordinary client socket
351 * wait queue. This connection is established whenever a write (or
352 * poll for write) hit the flow control condition and broken when the
353 * association to the server socket is dissolved or after a wake up
357 static int unix_dgram_peer_wake_relay(wait_queue_entry_t *q, unsigned mode, int flags,
361 wait_queue_head_t *u_sleep;
363 u = container_of(q, struct unix_sock, peer_wake);
365 __remove_wait_queue(&unix_sk(u->peer_wake.private)->peer_wait,
367 u->peer_wake.private = NULL;
369 /* relaying can only happen while the wq still exists */
370 u_sleep = sk_sleep(&u->sk);
372 wake_up_interruptible_poll(u_sleep, key_to_poll(key));
377 static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)
379 struct unix_sock *u, *u_other;
383 u_other = unix_sk(other);
385 spin_lock(&u_other->peer_wait.lock);
387 if (!u->peer_wake.private) {
388 u->peer_wake.private = other;
389 __add_wait_queue(&u_other->peer_wait, &u->peer_wake);
394 spin_unlock(&u_other->peer_wait.lock);
398 static void unix_dgram_peer_wake_disconnect(struct sock *sk,
401 struct unix_sock *u, *u_other;
404 u_other = unix_sk(other);
405 spin_lock(&u_other->peer_wait.lock);
407 if (u->peer_wake.private == other) {
408 __remove_wait_queue(&u_other->peer_wait, &u->peer_wake);
409 u->peer_wake.private = NULL;
412 spin_unlock(&u_other->peer_wait.lock);
415 static void unix_dgram_peer_wake_disconnect_wakeup(struct sock *sk,
418 unix_dgram_peer_wake_disconnect(sk, other);
419 wake_up_interruptible_poll(sk_sleep(sk),
426 * - unix_peer(sk) == other
427 * - association is stable
429 static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
433 connected = unix_dgram_peer_wake_connect(sk, other);
435 /* If other is SOCK_DEAD, we want to make sure we signal
436 * POLLOUT, such that a subsequent write() can get a
437 * -ECONNREFUSED. Otherwise, if we haven't queued any skbs
438 * to other and its full, we will hang waiting for POLLOUT.
440 if (unix_recvq_full(other) && !sock_flag(other, SOCK_DEAD))
444 unix_dgram_peer_wake_disconnect(sk, other);
449 static int unix_writable(const struct sock *sk)
451 return sk->sk_state != TCP_LISTEN &&
452 (refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
455 static void unix_write_space(struct sock *sk)
457 struct socket_wq *wq;
460 if (unix_writable(sk)) {
461 wq = rcu_dereference(sk->sk_wq);
462 if (skwq_has_sleeper(wq))
463 wake_up_interruptible_sync_poll(&wq->wait,
464 EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);
465 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
470 /* When dgram socket disconnects (or changes its peer), we clear its receive
471 * queue of packets arrived from previous peer. First, it allows to do
472 * flow control based only on wmem_alloc; second, sk connected to peer
473 * may receive messages only from that peer. */
474 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
476 if (!skb_queue_empty(&sk->sk_receive_queue)) {
477 skb_queue_purge(&sk->sk_receive_queue);
478 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
480 /* If one link of bidirectional dgram pipe is disconnected,
481 * we signal error. Messages are lost. Do not make this,
482 * when peer was not connected to us.
484 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
485 other->sk_err = ECONNRESET;
486 other->sk_error_report(other);
491 static void unix_sock_destructor(struct sock *sk)
493 struct unix_sock *u = unix_sk(sk);
495 skb_queue_purge(&sk->sk_receive_queue);
497 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
498 WARN_ON(!sk_unhashed(sk));
499 WARN_ON(sk->sk_socket);
500 if (!sock_flag(sk, SOCK_DEAD)) {
501 pr_info("Attempt to release alive unix socket: %p\n", sk);
506 unix_release_addr(u->addr);
508 atomic_long_dec(&unix_nr_socks);
510 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
512 #ifdef UNIX_REFCNT_DEBUG
513 pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk,
514 atomic_long_read(&unix_nr_socks));
518 static void unix_release_sock(struct sock *sk, int embrion)
520 struct unix_sock *u = unix_sk(sk);
526 unix_remove_socket(sk);
531 sk->sk_shutdown = SHUTDOWN_MASK;
533 u->path.dentry = NULL;
535 state = sk->sk_state;
536 sk->sk_state = TCP_CLOSE;
537 unix_state_unlock(sk);
539 wake_up_interruptible_all(&u->peer_wait);
541 skpair = unix_peer(sk);
543 if (skpair != NULL) {
544 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
545 unix_state_lock(skpair);
547 skpair->sk_shutdown = SHUTDOWN_MASK;
548 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
549 skpair->sk_err = ECONNRESET;
550 unix_state_unlock(skpair);
551 skpair->sk_state_change(skpair);
552 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
555 unix_dgram_peer_wake_disconnect(sk, skpair);
556 sock_put(skpair); /* It may now die */
557 unix_peer(sk) = NULL;
560 /* Try to flush out this socket. Throw out buffers at least */
562 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
563 if (state == TCP_LISTEN)
564 unix_release_sock(skb->sk, 1);
565 /* passed fds are erased in the kfree_skb hook */
566 UNIXCB(skb).consumed = skb->len;
575 /* ---- Socket is dead now and most probably destroyed ---- */
578 * Fixme: BSD difference: In BSD all sockets connected to us get
579 * ECONNRESET and we die on the spot. In Linux we behave
580 * like files and pipes do and wait for the last
583 * Can't we simply set sock->err?
585 * What the above comment does talk about? --ANK(980817)
588 if (unix_tot_inflight)
589 unix_gc(); /* Garbage collect fds */
592 static void init_peercred(struct sock *sk)
594 put_pid(sk->sk_peer_pid);
595 if (sk->sk_peer_cred)
596 put_cred(sk->sk_peer_cred);
597 sk->sk_peer_pid = get_pid(task_tgid(current));
598 sk->sk_peer_cred = get_current_cred();
601 static void copy_peercred(struct sock *sk, struct sock *peersk)
603 put_pid(sk->sk_peer_pid);
604 if (sk->sk_peer_cred)
605 put_cred(sk->sk_peer_cred);
606 sk->sk_peer_pid = get_pid(peersk->sk_peer_pid);
607 sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
610 static int unix_listen(struct socket *sock, int backlog)
613 struct sock *sk = sock->sk;
614 struct unix_sock *u = unix_sk(sk);
615 struct pid *old_pid = NULL;
618 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
619 goto out; /* Only stream/seqpacket sockets accept */
622 goto out; /* No listens on an unbound socket */
624 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
626 if (backlog > sk->sk_max_ack_backlog)
627 wake_up_interruptible_all(&u->peer_wait);
628 sk->sk_max_ack_backlog = backlog;
629 sk->sk_state = TCP_LISTEN;
630 /* set credentials so connect can copy them */
635 unix_state_unlock(sk);
641 static int unix_release(struct socket *);
642 static int unix_bind(struct socket *, struct sockaddr *, int);
643 static int unix_stream_connect(struct socket *, struct sockaddr *,
644 int addr_len, int flags);
645 static int unix_socketpair(struct socket *, struct socket *);
646 static int unix_accept(struct socket *, struct socket *, int, bool);
647 static int unix_getname(struct socket *, struct sockaddr *, int);
648 static __poll_t unix_poll(struct file *, struct socket *, poll_table *);
649 static __poll_t unix_dgram_poll(struct file *, struct socket *,
651 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
652 static int unix_shutdown(struct socket *, int);
653 static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t);
654 static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int);
655 static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset,
656 size_t size, int flags);
657 static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos,
658 struct pipe_inode_info *, size_t size,
660 static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
661 static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
662 static int unix_dgram_connect(struct socket *, struct sockaddr *,
664 static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t);
665 static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t,
668 static int unix_set_peek_off(struct sock *sk, int val)
670 struct unix_sock *u = unix_sk(sk);
672 if (mutex_lock_interruptible(&u->iolock))
675 sk->sk_peek_off = val;
676 mutex_unlock(&u->iolock);
682 static const struct proto_ops unix_stream_ops = {
684 .owner = THIS_MODULE,
685 .release = unix_release,
687 .connect = unix_stream_connect,
688 .socketpair = unix_socketpair,
689 .accept = unix_accept,
690 .getname = unix_getname,
693 .listen = unix_listen,
694 .shutdown = unix_shutdown,
695 .setsockopt = sock_no_setsockopt,
696 .getsockopt = sock_no_getsockopt,
697 .sendmsg = unix_stream_sendmsg,
698 .recvmsg = unix_stream_recvmsg,
699 .mmap = sock_no_mmap,
700 .sendpage = unix_stream_sendpage,
701 .splice_read = unix_stream_splice_read,
702 .set_peek_off = unix_set_peek_off,
705 static const struct proto_ops unix_dgram_ops = {
707 .owner = THIS_MODULE,
708 .release = unix_release,
710 .connect = unix_dgram_connect,
711 .socketpair = unix_socketpair,
712 .accept = sock_no_accept,
713 .getname = unix_getname,
714 .poll = unix_dgram_poll,
716 .listen = sock_no_listen,
717 .shutdown = unix_shutdown,
718 .setsockopt = sock_no_setsockopt,
719 .getsockopt = sock_no_getsockopt,
720 .sendmsg = unix_dgram_sendmsg,
721 .recvmsg = unix_dgram_recvmsg,
722 .mmap = sock_no_mmap,
723 .sendpage = sock_no_sendpage,
724 .set_peek_off = unix_set_peek_off,
727 static const struct proto_ops unix_seqpacket_ops = {
729 .owner = THIS_MODULE,
730 .release = unix_release,
732 .connect = unix_stream_connect,
733 .socketpair = unix_socketpair,
734 .accept = unix_accept,
735 .getname = unix_getname,
736 .poll = unix_dgram_poll,
738 .listen = unix_listen,
739 .shutdown = unix_shutdown,
740 .setsockopt = sock_no_setsockopt,
741 .getsockopt = sock_no_getsockopt,
742 .sendmsg = unix_seqpacket_sendmsg,
743 .recvmsg = unix_seqpacket_recvmsg,
744 .mmap = sock_no_mmap,
745 .sendpage = sock_no_sendpage,
746 .set_peek_off = unix_set_peek_off,
749 static struct proto unix_proto = {
751 .owner = THIS_MODULE,
752 .obj_size = sizeof(struct unix_sock),
755 static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
757 struct sock *sk = NULL;
760 atomic_long_inc(&unix_nr_socks);
761 if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
764 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto, kern);
768 sock_init_data(sock, sk);
770 sk->sk_allocation = GFP_KERNEL_ACCOUNT;
771 sk->sk_write_space = unix_write_space;
772 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
773 sk->sk_destruct = unix_sock_destructor;
775 u->path.dentry = NULL;
777 spin_lock_init(&u->lock);
778 atomic_long_set(&u->inflight, 0);
779 INIT_LIST_HEAD(&u->link);
780 mutex_init(&u->iolock); /* single task reading lock */
781 mutex_init(&u->bindlock); /* single task binding lock */
782 init_waitqueue_head(&u->peer_wait);
783 init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
784 unix_insert_socket(unix_sockets_unbound(sk), sk);
787 atomic_long_dec(&unix_nr_socks);
790 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
796 static int unix_create(struct net *net, struct socket *sock, int protocol,
799 if (protocol && protocol != PF_UNIX)
800 return -EPROTONOSUPPORT;
802 sock->state = SS_UNCONNECTED;
804 switch (sock->type) {
806 sock->ops = &unix_stream_ops;
809 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
813 sock->type = SOCK_DGRAM;
816 sock->ops = &unix_dgram_ops;
819 sock->ops = &unix_seqpacket_ops;
822 return -ESOCKTNOSUPPORT;
825 return unix_create1(net, sock, kern) ? 0 : -ENOMEM;
828 static int unix_release(struct socket *sock)
830 struct sock *sk = sock->sk;
835 unix_release_sock(sk, 0);
841 static int unix_autobind(struct socket *sock)
843 struct sock *sk = sock->sk;
844 struct net *net = sock_net(sk);
845 struct unix_sock *u = unix_sk(sk);
846 static u32 ordernum = 1;
847 struct unix_address *addr;
849 unsigned int retries = 0;
851 err = mutex_lock_interruptible(&u->bindlock);
860 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
864 addr->name->sun_family = AF_UNIX;
865 refcount_set(&addr->refcnt, 1);
868 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
869 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
871 spin_lock(&unix_table_lock);
872 ordernum = (ordernum+1)&0xFFFFF;
874 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
876 spin_unlock(&unix_table_lock);
878 * __unix_find_socket_byname() may take long time if many names
879 * are already in use.
882 /* Give up if all names seems to be in use. */
883 if (retries++ == 0xFFFFF) {
890 addr->hash ^= sk->sk_type;
892 __unix_remove_socket(sk);
893 smp_store_release(&u->addr, addr);
894 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
895 spin_unlock(&unix_table_lock);
898 out: mutex_unlock(&u->bindlock);
902 static struct sock *unix_find_other(struct net *net,
903 struct sockaddr_un *sunname, int len,
904 int type, unsigned int hash, int *error)
910 if (sunname->sun_path[0]) {
912 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
915 inode = d_backing_inode(path.dentry);
916 err = inode_permission(inode, MAY_WRITE);
921 if (!S_ISSOCK(inode->i_mode))
923 u = unix_find_socket_byinode(inode);
927 if (u->sk_type == type)
933 if (u->sk_type != type) {
939 u = unix_find_socket_byname(net, sunname, len, type, hash);
941 struct dentry *dentry;
942 dentry = unix_sk(u)->path.dentry;
944 touch_atime(&unix_sk(u)->path);
957 static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
959 struct dentry *dentry;
963 * Get the parent directory, calculate the hash for last
966 dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
967 err = PTR_ERR(dentry);
972 * All right, let's create it.
974 err = security_path_mknod(&path, dentry, mode, 0);
976 err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0);
978 res->mnt = mntget(path.mnt);
979 res->dentry = dget(dentry);
982 done_path_create(&path, dentry);
986 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
988 struct sock *sk = sock->sk;
989 struct net *net = sock_net(sk);
990 struct unix_sock *u = unix_sk(sk);
991 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
992 char *sun_path = sunaddr->sun_path;
995 struct unix_address *addr;
996 struct hlist_head *list;
997 struct path path = { };
1000 if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
1001 sunaddr->sun_family != AF_UNIX)
1004 if (addr_len == sizeof(short)) {
1005 err = unix_autobind(sock);
1009 err = unix_mkname(sunaddr, addr_len, &hash);
1015 umode_t mode = S_IFSOCK |
1016 (SOCK_INODE(sock)->i_mode & ~current_umask());
1017 err = unix_mknod(sun_path, mode, &path);
1025 err = mutex_lock_interruptible(&u->bindlock);
1034 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
1038 memcpy(addr->name, sunaddr, addr_len);
1039 addr->len = addr_len;
1040 addr->hash = hash ^ sk->sk_type;
1041 refcount_set(&addr->refcnt, 1);
1044 addr->hash = UNIX_HASH_SIZE;
1045 hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
1046 spin_lock(&unix_table_lock);
1048 list = &unix_socket_table[hash];
1050 spin_lock(&unix_table_lock);
1052 if (__unix_find_socket_byname(net, sunaddr, addr_len,
1053 sk->sk_type, hash)) {
1054 unix_release_addr(addr);
1058 list = &unix_socket_table[addr->hash];
1062 __unix_remove_socket(sk);
1063 smp_store_release(&u->addr, addr);
1064 __unix_insert_socket(list, sk);
1067 spin_unlock(&unix_table_lock);
1069 mutex_unlock(&u->bindlock);
1077 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
1079 if (unlikely(sk1 == sk2) || !sk2) {
1080 unix_state_lock(sk1);
1084 unix_state_lock(sk1);
1085 unix_state_lock_nested(sk2);
1087 unix_state_lock(sk2);
1088 unix_state_lock_nested(sk1);
1092 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
1094 if (unlikely(sk1 == sk2) || !sk2) {
1095 unix_state_unlock(sk1);
1098 unix_state_unlock(sk1);
1099 unix_state_unlock(sk2);
1102 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
1103 int alen, int flags)
1105 struct sock *sk = sock->sk;
1106 struct net *net = sock_net(sk);
1107 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
1113 if (alen < offsetofend(struct sockaddr, sa_family))
1116 if (addr->sa_family != AF_UNSPEC) {
1117 err = unix_mkname(sunaddr, alen, &hash);
1122 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
1123 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
1127 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
1131 unix_state_double_lock(sk, other);
1133 /* Apparently VFS overslept socket death. Retry. */
1134 if (sock_flag(other, SOCK_DEAD)) {
1135 unix_state_double_unlock(sk, other);
1141 if (!unix_may_send(sk, other))
1144 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1150 * 1003.1g breaking connected state with AF_UNSPEC
1153 unix_state_double_lock(sk, other);
1157 * If it was connected, reconnect.
1159 if (unix_peer(sk)) {
1160 struct sock *old_peer = unix_peer(sk);
1161 unix_peer(sk) = other;
1162 unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer);
1164 unix_state_double_unlock(sk, other);
1166 if (other != old_peer)
1167 unix_dgram_disconnected(sk, old_peer);
1170 unix_peer(sk) = other;
1171 unix_state_double_unlock(sk, other);
1176 unix_state_double_unlock(sk, other);
1182 static long unix_wait_for_peer(struct sock *other, long timeo)
1184 struct unix_sock *u = unix_sk(other);
1188 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1190 sched = !sock_flag(other, SOCK_DEAD) &&
1191 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1192 unix_recvq_full(other);
1194 unix_state_unlock(other);
1197 timeo = schedule_timeout(timeo);
1199 finish_wait(&u->peer_wait, &wait);
1203 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1204 int addr_len, int flags)
1206 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
1207 struct sock *sk = sock->sk;
1208 struct net *net = sock_net(sk);
1209 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1210 struct sock *newsk = NULL;
1211 struct sock *other = NULL;
1212 struct sk_buff *skb = NULL;
1218 err = unix_mkname(sunaddr, addr_len, &hash);
1223 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1224 (err = unix_autobind(sock)) != 0)
1227 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1229 /* First of all allocate resources.
1230 If we will make it after state is locked,
1231 we will have to recheck all again in any case.
1236 /* create new sock for complete connection */
1237 newsk = unix_create1(sock_net(sk), NULL, 0);
1241 /* Allocate skb for sending to listening sock */
1242 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1247 /* Find listening sock. */
1248 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1252 /* Latch state of peer */
1253 unix_state_lock(other);
1255 /* Apparently VFS overslept socket death. Retry. */
1256 if (sock_flag(other, SOCK_DEAD)) {
1257 unix_state_unlock(other);
1262 err = -ECONNREFUSED;
1263 if (other->sk_state != TCP_LISTEN)
1265 if (other->sk_shutdown & RCV_SHUTDOWN)
1268 if (unix_recvq_full(other)) {
1273 timeo = unix_wait_for_peer(other, timeo);
1275 err = sock_intr_errno(timeo);
1276 if (signal_pending(current))
1284 It is tricky place. We need to grab our state lock and cannot
1285 drop lock on peer. It is dangerous because deadlock is
1286 possible. Connect to self case and simultaneous
1287 attempt to connect are eliminated by checking socket
1288 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1289 check this before attempt to grab lock.
1291 Well, and we have to recheck the state after socket locked.
1297 /* This is ok... continue with connect */
1299 case TCP_ESTABLISHED:
1300 /* Socket is already connected */
1308 unix_state_lock_nested(sk);
1310 if (sk->sk_state != st) {
1311 unix_state_unlock(sk);
1312 unix_state_unlock(other);
1317 err = security_unix_stream_connect(sk, other, newsk);
1319 unix_state_unlock(sk);
1323 /* The way is open! Fastly set all the necessary fields... */
1326 unix_peer(newsk) = sk;
1327 newsk->sk_state = TCP_ESTABLISHED;
1328 newsk->sk_type = sk->sk_type;
1329 init_peercred(newsk);
1330 newu = unix_sk(newsk);
1331 RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq);
1332 otheru = unix_sk(other);
1334 /* copy address information from listening to new sock
1336 * The contents of *(otheru->addr) and otheru->path
1337 * are seen fully set up here, since we have found
1338 * otheru in hash under unix_table_lock. Insertion
1339 * into the hash chain we'd found it in had been done
1340 * in an earlier critical area protected by unix_table_lock,
1341 * the same one where we'd set *(otheru->addr) contents,
1342 * as well as otheru->path and otheru->addr itself.
1344 * Using smp_store_release() here to set newu->addr
1345 * is enough to make those stores, as well as stores
1346 * to newu->path visible to anyone who gets newu->addr
1347 * by smp_load_acquire(). IOW, the same warranties
1348 * as for unix_sock instances bound in unix_bind() or
1349 * in unix_autobind().
1351 if (otheru->path.dentry) {
1352 path_get(&otheru->path);
1353 newu->path = otheru->path;
1355 refcount_inc(&otheru->addr->refcnt);
1356 smp_store_release(&newu->addr, otheru->addr);
1358 /* Set credentials */
1359 copy_peercred(sk, other);
1361 sock->state = SS_CONNECTED;
1362 sk->sk_state = TCP_ESTABLISHED;
1365 smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */
1366 unix_peer(sk) = newsk;
1368 unix_state_unlock(sk);
1370 /* take ten and and send info to listening sock */
1371 spin_lock(&other->sk_receive_queue.lock);
1372 __skb_queue_tail(&other->sk_receive_queue, skb);
1373 spin_unlock(&other->sk_receive_queue.lock);
1374 unix_state_unlock(other);
1375 other->sk_data_ready(other);
1381 unix_state_unlock(other);
1386 unix_release_sock(newsk, 0);
1392 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1394 struct sock *ska = socka->sk, *skb = sockb->sk;
1396 /* Join our sockets back to back */
1399 unix_peer(ska) = skb;
1400 unix_peer(skb) = ska;
1404 if (ska->sk_type != SOCK_DGRAM) {
1405 ska->sk_state = TCP_ESTABLISHED;
1406 skb->sk_state = TCP_ESTABLISHED;
1407 socka->state = SS_CONNECTED;
1408 sockb->state = SS_CONNECTED;
1413 static void unix_sock_inherit_flags(const struct socket *old,
1416 if (test_bit(SOCK_PASSCRED, &old->flags))
1417 set_bit(SOCK_PASSCRED, &new->flags);
1418 if (test_bit(SOCK_PASSSEC, &old->flags))
1419 set_bit(SOCK_PASSSEC, &new->flags);
1422 static int unix_accept(struct socket *sock, struct socket *newsock, int flags,
1425 struct sock *sk = sock->sk;
1427 struct sk_buff *skb;
1431 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
1435 if (sk->sk_state != TCP_LISTEN)
1438 /* If socket state is TCP_LISTEN it cannot change (for now...),
1439 * so that no locks are necessary.
1442 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1444 /* This means receive shutdown. */
1451 skb_free_datagram(sk, skb);
1452 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1454 /* attach accepted sock to socket */
1455 unix_state_lock(tsk);
1456 newsock->state = SS_CONNECTED;
1457 unix_sock_inherit_flags(sock, newsock);
1458 sock_graft(tsk, newsock);
1459 unix_state_unlock(tsk);
1467 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1469 struct sock *sk = sock->sk;
1470 struct unix_address *addr;
1471 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
1475 sk = unix_peer_get(sk);
1485 addr = smp_load_acquire(&unix_sk(sk)->addr);
1487 sunaddr->sun_family = AF_UNIX;
1488 sunaddr->sun_path[0] = 0;
1489 err = sizeof(short);
1492 memcpy(sunaddr, addr->name, addr->len);
1499 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1503 scm->fp = UNIXCB(skb).fp;
1504 UNIXCB(skb).fp = NULL;
1506 for (i = scm->fp->count-1; i >= 0; i--)
1507 unix_notinflight(scm->fp->user, scm->fp->fp[i]);
1510 static void unix_destruct_scm(struct sk_buff *skb)
1512 struct scm_cookie scm;
1513 memset(&scm, 0, sizeof(scm));
1514 scm.pid = UNIXCB(skb).pid;
1516 unix_detach_fds(&scm, skb);
1518 /* Alas, it calls VFS */
1519 /* So fscking what? fput() had been SMP-safe since the last Summer */
1525 * The "user->unix_inflight" variable is protected by the garbage
1526 * collection lock, and we just read it locklessly here. If you go
1527 * over the limit, there might be a tiny race in actually noticing
1528 * it across threads. Tough.
1530 static inline bool too_many_unix_fds(struct task_struct *p)
1532 struct user_struct *user = current_user();
1534 if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
1535 return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
1539 static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1543 if (too_many_unix_fds(current))
1544 return -ETOOMANYREFS;
1547 * Need to duplicate file references for the sake of garbage
1548 * collection. Otherwise a socket in the fps might become a
1549 * candidate for GC while the skb is not yet queued.
1551 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1552 if (!UNIXCB(skb).fp)
1555 for (i = scm->fp->count - 1; i >= 0; i--)
1556 unix_inflight(scm->fp->user, scm->fp->fp[i]);
1560 static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
1564 UNIXCB(skb).pid = get_pid(scm->pid);
1565 UNIXCB(skb).uid = scm->creds.uid;
1566 UNIXCB(skb).gid = scm->creds.gid;
1567 UNIXCB(skb).fp = NULL;
1568 unix_get_secdata(scm, skb);
1569 if (scm->fp && send_fds)
1570 err = unix_attach_fds(scm, skb);
1572 skb->destructor = unix_destruct_scm;
1576 static bool unix_passcred_enabled(const struct socket *sock,
1577 const struct sock *other)
1579 return test_bit(SOCK_PASSCRED, &sock->flags) ||
1580 !other->sk_socket ||
1581 test_bit(SOCK_PASSCRED, &other->sk_socket->flags);
1585 * Some apps rely on write() giving SCM_CREDENTIALS
1586 * We include credentials if source or destination socket
1587 * asserted SOCK_PASSCRED.
1589 static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
1590 const struct sock *other)
1592 if (UNIXCB(skb).pid)
1594 if (unix_passcred_enabled(sock, other)) {
1595 UNIXCB(skb).pid = get_pid(task_tgid(current));
1596 current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
1600 static int maybe_init_creds(struct scm_cookie *scm,
1601 struct socket *socket,
1602 const struct sock *other)
1605 struct msghdr msg = { .msg_controllen = 0 };
1607 err = scm_send(socket, &msg, scm, false);
1611 if (unix_passcred_enabled(socket, other)) {
1612 scm->pid = get_pid(task_tgid(current));
1613 current_uid_gid(&scm->creds.uid, &scm->creds.gid);
1618 static bool unix_skb_scm_eq(struct sk_buff *skb,
1619 struct scm_cookie *scm)
1621 const struct unix_skb_parms *u = &UNIXCB(skb);
1623 return u->pid == scm->pid &&
1624 uid_eq(u->uid, scm->creds.uid) &&
1625 gid_eq(u->gid, scm->creds.gid) &&
1626 unix_secdata_eq(scm, skb);
1630 * Send AF_UNIX data.
1633 static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1636 struct sock *sk = sock->sk;
1637 struct net *net = sock_net(sk);
1638 struct unix_sock *u = unix_sk(sk);
1639 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
1640 struct sock *other = NULL;
1641 int namelen = 0; /* fake GCC */
1644 struct sk_buff *skb;
1646 struct scm_cookie scm;
1651 err = scm_send(sock, msg, &scm, false);
1656 if (msg->msg_flags&MSG_OOB)
1659 if (msg->msg_namelen) {
1660 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1667 other = unix_peer_get(sk);
1672 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1673 && (err = unix_autobind(sock)) != 0)
1677 if (len > sk->sk_sndbuf - 32)
1680 if (len > SKB_MAX_ALLOC) {
1681 data_len = min_t(size_t,
1682 len - SKB_MAX_ALLOC,
1683 MAX_SKB_FRAGS * PAGE_SIZE);
1684 data_len = PAGE_ALIGN(data_len);
1686 BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE);
1689 skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
1690 msg->msg_flags & MSG_DONTWAIT, &err,
1691 PAGE_ALLOC_COSTLY_ORDER);
1695 err = unix_scm_to_skb(&scm, skb, true);
1699 skb_put(skb, len - data_len);
1700 skb->data_len = data_len;
1702 err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1706 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1711 if (sunaddr == NULL)
1714 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1720 if (sk_filter(other, skb) < 0) {
1721 /* Toss the packet but do not return any error to the sender */
1727 unix_state_lock(other);
1730 if (!unix_may_send(sk, other))
1733 if (unlikely(sock_flag(other, SOCK_DEAD))) {
1735 * Check with 1003.1g - what should
1738 unix_state_unlock(other);
1742 unix_state_lock(sk);
1745 if (unix_peer(sk) == other) {
1746 unix_peer(sk) = NULL;
1747 unix_dgram_peer_wake_disconnect_wakeup(sk, other);
1749 unix_state_unlock(sk);
1751 unix_dgram_disconnected(sk, other);
1753 err = -ECONNREFUSED;
1755 unix_state_unlock(sk);
1765 if (other->sk_shutdown & RCV_SHUTDOWN)
1768 if (sk->sk_type != SOCK_SEQPACKET) {
1769 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1774 /* other == sk && unix_peer(other) != sk if
1775 * - unix_peer(sk) == NULL, destination address bound to sk
1776 * - unix_peer(sk) == sk by time of get but disconnected before lock
1779 unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {
1781 timeo = unix_wait_for_peer(other, timeo);
1783 err = sock_intr_errno(timeo);
1784 if (signal_pending(current))
1791 unix_state_unlock(other);
1792 unix_state_double_lock(sk, other);
1795 if (unix_peer(sk) != other ||
1796 unix_dgram_peer_wake_me(sk, other)) {
1804 goto restart_locked;
1808 if (unlikely(sk_locked))
1809 unix_state_unlock(sk);
1811 if (sock_flag(other, SOCK_RCVTSTAMP))
1812 __net_timestamp(skb);
1813 maybe_add_creds(skb, sock, other);
1814 skb_queue_tail(&other->sk_receive_queue, skb);
1815 unix_state_unlock(other);
1816 other->sk_data_ready(other);
1823 unix_state_unlock(sk);
1824 unix_state_unlock(other);
1834 /* We use paged skbs for stream sockets, and limit occupancy to 32768
1835 * bytes, and a minimum of a full page.
1837 #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768))
1839 static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1842 struct sock *sk = sock->sk;
1843 struct sock *other = NULL;
1845 struct sk_buff *skb;
1847 struct scm_cookie scm;
1848 bool fds_sent = false;
1852 err = scm_send(sock, msg, &scm, false);
1857 if (msg->msg_flags&MSG_OOB)
1860 if (msg->msg_namelen) {
1861 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1865 other = unix_peer(sk);
1870 if (sk->sk_shutdown & SEND_SHUTDOWN)
1873 while (sent < len) {
1876 /* Keep two messages in the pipe so it schedules better */
1877 size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
1879 /* allow fallback to order-0 allocations */
1880 size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
1882 data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
1884 data_len = min_t(size_t, size, PAGE_ALIGN(data_len));
1886 skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
1887 msg->msg_flags & MSG_DONTWAIT, &err,
1888 get_order(UNIX_SKB_FRAGS_SZ));
1892 /* Only send the fds in the first buffer */
1893 err = unix_scm_to_skb(&scm, skb, !fds_sent);
1900 skb_put(skb, size - data_len);
1901 skb->data_len = data_len;
1903 err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size);
1909 unix_state_lock(other);
1911 if (sock_flag(other, SOCK_DEAD) ||
1912 (other->sk_shutdown & RCV_SHUTDOWN))
1915 maybe_add_creds(skb, sock, other);
1916 skb_queue_tail(&other->sk_receive_queue, skb);
1917 unix_state_unlock(other);
1918 other->sk_data_ready(other);
1927 unix_state_unlock(other);
1930 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1931 send_sig(SIGPIPE, current, 0);
1935 return sent ? : err;
1938 static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
1939 int offset, size_t size, int flags)
1942 bool send_sigpipe = false;
1943 bool init_scm = true;
1944 struct scm_cookie scm;
1945 struct sock *other, *sk = socket->sk;
1946 struct sk_buff *skb, *newskb = NULL, *tail = NULL;
1948 if (flags & MSG_OOB)
1951 other = unix_peer(sk);
1952 if (!other || sk->sk_state != TCP_ESTABLISHED)
1957 unix_state_unlock(other);
1958 mutex_unlock(&unix_sk(other)->iolock);
1959 newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
1965 /* we must acquire iolock as we modify already present
1966 * skbs in the sk_receive_queue and mess with skb->len
1968 err = mutex_lock_interruptible(&unix_sk(other)->iolock);
1970 err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
1974 if (sk->sk_shutdown & SEND_SHUTDOWN) {
1976 send_sigpipe = true;
1980 unix_state_lock(other);
1982 if (sock_flag(other, SOCK_DEAD) ||
1983 other->sk_shutdown & RCV_SHUTDOWN) {
1985 send_sigpipe = true;
1986 goto err_state_unlock;
1990 err = maybe_init_creds(&scm, socket, other);
1992 goto err_state_unlock;
1996 skb = skb_peek_tail(&other->sk_receive_queue);
1997 if (tail && tail == skb) {
1999 } else if (!skb || !unix_skb_scm_eq(skb, &scm)) {
2006 } else if (newskb) {
2007 /* this is fast path, we don't necessarily need to
2008 * call to kfree_skb even though with newskb == NULL
2009 * this - does no harm
2011 consume_skb(newskb);
2015 if (skb_append_pagefrags(skb, page, offset, size)) {
2021 skb->data_len += size;
2022 skb->truesize += size;
2023 refcount_add(size, &sk->sk_wmem_alloc);
2026 err = unix_scm_to_skb(&scm, skb, false);
2028 goto err_state_unlock;
2029 spin_lock(&other->sk_receive_queue.lock);
2030 __skb_queue_tail(&other->sk_receive_queue, newskb);
2031 spin_unlock(&other->sk_receive_queue.lock);
2034 unix_state_unlock(other);
2035 mutex_unlock(&unix_sk(other)->iolock);
2037 other->sk_data_ready(other);
2042 unix_state_unlock(other);
2044 mutex_unlock(&unix_sk(other)->iolock);
2047 if (send_sigpipe && !(flags & MSG_NOSIGNAL))
2048 send_sig(SIGPIPE, current, 0);
2054 static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg,
2058 struct sock *sk = sock->sk;
2060 err = sock_error(sk);
2064 if (sk->sk_state != TCP_ESTABLISHED)
2067 if (msg->msg_namelen)
2068 msg->msg_namelen = 0;
2070 return unix_dgram_sendmsg(sock, msg, len);
2073 static int unix_seqpacket_recvmsg(struct socket *sock, struct msghdr *msg,
2074 size_t size, int flags)
2076 struct sock *sk = sock->sk;
2078 if (sk->sk_state != TCP_ESTABLISHED)
2081 return unix_dgram_recvmsg(sock, msg, size, flags);
2084 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
2086 struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);
2089 msg->msg_namelen = addr->len;
2090 memcpy(msg->msg_name, addr->name, addr->len);
2094 static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
2095 size_t size, int flags)
2097 struct scm_cookie scm;
2098 struct sock *sk = sock->sk;
2099 struct unix_sock *u = unix_sk(sk);
2100 struct sk_buff *skb, *last;
2109 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2112 mutex_lock(&u->iolock);
2114 skip = sk_peek_offset(sk, flags);
2115 skb = __skb_try_recv_datagram(sk, flags, NULL, &peeked, &skip,
2120 mutex_unlock(&u->iolock);
2125 !__skb_wait_for_more_packets(sk, &err, &timeo, last));
2127 if (!skb) { /* implies iolock unlocked */
2128 unix_state_lock(sk);
2129 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
2130 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
2131 (sk->sk_shutdown & RCV_SHUTDOWN))
2133 unix_state_unlock(sk);
2137 if (wq_has_sleeper(&u->peer_wait))
2138 wake_up_interruptible_sync_poll(&u->peer_wait,
2139 EPOLLOUT | EPOLLWRNORM |
2143 unix_copy_addr(msg, skb->sk);
2145 if (size > skb->len - skip)
2146 size = skb->len - skip;
2147 else if (size < skb->len - skip)
2148 msg->msg_flags |= MSG_TRUNC;
2150 err = skb_copy_datagram_msg(skb, skip, msg, size);
2154 if (sock_flag(sk, SOCK_RCVTSTAMP))
2155 __sock_recv_timestamp(msg, sk, skb);
2157 memset(&scm, 0, sizeof(scm));
2159 scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
2160 unix_set_secdata(&scm, skb);
2162 if (!(flags & MSG_PEEK)) {
2164 unix_detach_fds(&scm, skb);
2166 sk_peek_offset_bwd(sk, skb->len);
2168 /* It is questionable: on PEEK we could:
2169 - do not return fds - good, but too simple 8)
2170 - return fds, and do not return them on read (old strategy,
2172 - clone fds (I chose it for now, it is the most universal
2175 POSIX 1003.1g does not actually define this clearly
2176 at all. POSIX 1003.1g doesn't define a lot of things
2181 sk_peek_offset_fwd(sk, size);
2184 scm.fp = scm_fp_dup(UNIXCB(skb).fp);
2186 err = (flags & MSG_TRUNC) ? skb->len - skip : size;
2188 scm_recv(sock, msg, &scm, flags);
2191 skb_free_datagram(sk, skb);
2192 mutex_unlock(&u->iolock);
2198 * Sleep until more data has arrived. But check for races..
2200 static long unix_stream_data_wait(struct sock *sk, long timeo,
2201 struct sk_buff *last, unsigned int last_len,
2204 struct sk_buff *tail;
2207 unix_state_lock(sk);
2210 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2212 tail = skb_peek_tail(&sk->sk_receive_queue);
2214 (tail && tail->len != last_len) ||
2216 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2217 signal_pending(current) ||
2221 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2222 unix_state_unlock(sk);
2224 timeo = freezable_schedule_timeout(timeo);
2226 timeo = schedule_timeout(timeo);
2227 unix_state_lock(sk);
2229 if (sock_flag(sk, SOCK_DEAD))
2232 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2235 finish_wait(sk_sleep(sk), &wait);
2236 unix_state_unlock(sk);
2240 static unsigned int unix_skb_len(const struct sk_buff *skb)
2242 return skb->len - UNIXCB(skb).consumed;
2245 struct unix_stream_read_state {
2246 int (*recv_actor)(struct sk_buff *, int, int,
2247 struct unix_stream_read_state *);
2248 struct socket *socket;
2250 struct pipe_inode_info *pipe;
2253 unsigned int splice_flags;
2256 static int unix_stream_read_generic(struct unix_stream_read_state *state,
2259 struct scm_cookie scm;
2260 struct socket *sock = state->socket;
2261 struct sock *sk = sock->sk;
2262 struct unix_sock *u = unix_sk(sk);
2264 int flags = state->flags;
2265 int noblock = flags & MSG_DONTWAIT;
2266 bool check_creds = false;
2271 size_t size = state->size;
2272 unsigned int last_len;
2274 if (unlikely(sk->sk_state != TCP_ESTABLISHED)) {
2279 if (unlikely(flags & MSG_OOB)) {
2284 target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
2285 timeo = sock_rcvtimeo(sk, noblock);
2287 memset(&scm, 0, sizeof(scm));
2289 /* Lock the socket to prevent queue disordering
2290 * while sleeps in memcpy_tomsg
2292 mutex_lock(&u->iolock);
2294 skip = max(sk_peek_offset(sk, flags), 0);
2299 struct sk_buff *skb, *last;
2302 unix_state_lock(sk);
2303 if (sock_flag(sk, SOCK_DEAD)) {
2307 last = skb = skb_peek(&sk->sk_receive_queue);
2308 last_len = last ? last->len : 0;
2311 if (copied >= target)
2315 * POSIX 1003.1g mandates this order.
2318 err = sock_error(sk);
2321 if (sk->sk_shutdown & RCV_SHUTDOWN)
2324 unix_state_unlock(sk);
2330 mutex_unlock(&u->iolock);
2332 timeo = unix_stream_data_wait(sk, timeo, last,
2333 last_len, freezable);
2335 if (signal_pending(current)) {
2336 err = sock_intr_errno(timeo);
2341 mutex_lock(&u->iolock);
2344 unix_state_unlock(sk);
2348 while (skip >= unix_skb_len(skb)) {
2349 skip -= unix_skb_len(skb);
2351 last_len = skb->len;
2352 skb = skb_peek_next(skb, &sk->sk_receive_queue);
2357 unix_state_unlock(sk);
2360 /* Never glue messages from different writers */
2361 if (!unix_skb_scm_eq(skb, &scm))
2363 } else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
2364 /* Copy credentials */
2365 scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
2366 unix_set_secdata(&scm, skb);
2370 /* Copy address just once */
2371 if (state->msg && state->msg->msg_name) {
2372 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr,
2373 state->msg->msg_name);
2374 unix_copy_addr(state->msg, skb->sk);
2378 chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size);
2380 chunk = state->recv_actor(skb, skip, chunk, state);
2381 drop_skb = !unix_skb_len(skb);
2382 /* skb is only safe to use if !drop_skb */
2393 /* the skb was touched by a concurrent reader;
2394 * we should not expect anything from this skb
2395 * anymore and assume it invalid - we can be
2396 * sure it was dropped from the socket queue
2398 * let's report a short read
2404 /* Mark read part of skb as used */
2405 if (!(flags & MSG_PEEK)) {
2406 UNIXCB(skb).consumed += chunk;
2408 sk_peek_offset_bwd(sk, chunk);
2411 unix_detach_fds(&scm, skb);
2413 if (unix_skb_len(skb))
2416 skb_unlink(skb, &sk->sk_receive_queue);
2422 /* It is questionable, see note in unix_dgram_recvmsg.
2425 scm.fp = scm_fp_dup(UNIXCB(skb).fp);
2427 sk_peek_offset_fwd(sk, chunk);
2434 last_len = skb->len;
2435 unix_state_lock(sk);
2436 skb = skb_peek_next(skb, &sk->sk_receive_queue);
2439 unix_state_unlock(sk);
2444 mutex_unlock(&u->iolock);
2446 scm_recv(sock, state->msg, &scm, flags);
2450 return copied ? : err;
2453 static int unix_stream_read_actor(struct sk_buff *skb,
2454 int skip, int chunk,
2455 struct unix_stream_read_state *state)
2459 ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip,
2461 return ret ?: chunk;
2464 static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
2465 size_t size, int flags)
2467 struct unix_stream_read_state state = {
2468 .recv_actor = unix_stream_read_actor,
2475 return unix_stream_read_generic(&state, true);
2478 static int unix_stream_splice_actor(struct sk_buff *skb,
2479 int skip, int chunk,
2480 struct unix_stream_read_state *state)
2482 return skb_splice_bits(skb, state->socket->sk,
2483 UNIXCB(skb).consumed + skip,
2484 state->pipe, chunk, state->splice_flags);
2487 static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos,
2488 struct pipe_inode_info *pipe,
2489 size_t size, unsigned int flags)
2491 struct unix_stream_read_state state = {
2492 .recv_actor = unix_stream_splice_actor,
2496 .splice_flags = flags,
2499 if (unlikely(*ppos))
2502 if (sock->file->f_flags & O_NONBLOCK ||
2503 flags & SPLICE_F_NONBLOCK)
2504 state.flags = MSG_DONTWAIT;
2506 return unix_stream_read_generic(&state, false);
2509 static int unix_shutdown(struct socket *sock, int mode)
2511 struct sock *sk = sock->sk;
2514 if (mode < SHUT_RD || mode > SHUT_RDWR)
2517 * SHUT_RD (0) -> RCV_SHUTDOWN (1)
2518 * SHUT_WR (1) -> SEND_SHUTDOWN (2)
2519 * SHUT_RDWR (2) -> SHUTDOWN_MASK (3)
2523 unix_state_lock(sk);
2524 sk->sk_shutdown |= mode;
2525 other = unix_peer(sk);
2528 unix_state_unlock(sk);
2529 sk->sk_state_change(sk);
2532 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
2536 if (mode&RCV_SHUTDOWN)
2537 peer_mode |= SEND_SHUTDOWN;
2538 if (mode&SEND_SHUTDOWN)
2539 peer_mode |= RCV_SHUTDOWN;
2540 unix_state_lock(other);
2541 other->sk_shutdown |= peer_mode;
2542 unix_state_unlock(other);
2543 other->sk_state_change(other);
2544 if (peer_mode == SHUTDOWN_MASK)
2545 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
2546 else if (peer_mode & RCV_SHUTDOWN)
2547 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
2555 long unix_inq_len(struct sock *sk)
2557 struct sk_buff *skb;
2560 if (sk->sk_state == TCP_LISTEN)
2563 spin_lock(&sk->sk_receive_queue.lock);
2564 if (sk->sk_type == SOCK_STREAM ||
2565 sk->sk_type == SOCK_SEQPACKET) {
2566 skb_queue_walk(&sk->sk_receive_queue, skb)
2567 amount += unix_skb_len(skb);
2569 skb = skb_peek(&sk->sk_receive_queue);
2573 spin_unlock(&sk->sk_receive_queue.lock);
2577 EXPORT_SYMBOL_GPL(unix_inq_len);
2579 long unix_outq_len(struct sock *sk)
2581 return sk_wmem_alloc_get(sk);
2583 EXPORT_SYMBOL_GPL(unix_outq_len);
2585 static int unix_open_file(struct sock *sk)
2591 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2594 if (!smp_load_acquire(&unix_sk(sk)->addr))
2597 path = unix_sk(sk)->path;
2603 fd = get_unused_fd_flags(O_CLOEXEC);
2607 f = dentry_open(&path, O_PATH, current_cred());
2621 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2623 struct sock *sk = sock->sk;
2629 amount = unix_outq_len(sk);
2630 err = put_user(amount, (int __user *)arg);
2633 amount = unix_inq_len(sk);
2637 err = put_user(amount, (int __user *)arg);
2640 err = unix_open_file(sk);
2649 static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wait)
2651 struct sock *sk = sock->sk;
2654 sock_poll_wait(file, sock, wait);
2657 /* exceptional events? */
2660 if (sk->sk_shutdown == SHUTDOWN_MASK)
2662 if (sk->sk_shutdown & RCV_SHUTDOWN)
2663 mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
2666 if (!skb_queue_empty(&sk->sk_receive_queue))
2667 mask |= EPOLLIN | EPOLLRDNORM;
2669 /* Connection-based need to check for termination and startup */
2670 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2671 sk->sk_state == TCP_CLOSE)
2675 * we set writable also when the other side has shut down the
2676 * connection. This prevents stuck sockets.
2678 if (unix_writable(sk))
2679 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
2684 static __poll_t unix_dgram_poll(struct file *file, struct socket *sock,
2687 struct sock *sk = sock->sk, *other;
2688 unsigned int writable;
2691 sock_poll_wait(file, sock, wait);
2694 /* exceptional events? */
2695 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2697 (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
2699 if (sk->sk_shutdown & RCV_SHUTDOWN)
2700 mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
2701 if (sk->sk_shutdown == SHUTDOWN_MASK)
2705 if (!skb_queue_empty(&sk->sk_receive_queue))
2706 mask |= EPOLLIN | EPOLLRDNORM;
2708 /* Connection-based need to check for termination and startup */
2709 if (sk->sk_type == SOCK_SEQPACKET) {
2710 if (sk->sk_state == TCP_CLOSE)
2712 /* connection hasn't started yet? */
2713 if (sk->sk_state == TCP_SYN_SENT)
2717 /* No write status requested, avoid expensive OUT tests. */
2718 if (!(poll_requested_events(wait) & (EPOLLWRBAND|EPOLLWRNORM|EPOLLOUT)))
2721 writable = unix_writable(sk);
2723 unix_state_lock(sk);
2725 other = unix_peer(sk);
2726 if (other && unix_peer(other) != sk &&
2727 unix_recvq_full(other) &&
2728 unix_dgram_peer_wake_me(sk, other))
2731 unix_state_unlock(sk);
2735 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
2737 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2742 #ifdef CONFIG_PROC_FS
2744 #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
2746 #define get_bucket(x) ((x) >> BUCKET_SPACE)
2747 #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1))
2748 #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
2750 static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
2752 unsigned long offset = get_offset(*pos);
2753 unsigned long bucket = get_bucket(*pos);
2755 unsigned long count = 0;
2757 for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) {
2758 if (sock_net(sk) != seq_file_net(seq))
2760 if (++count == offset)
2767 static struct sock *unix_next_socket(struct seq_file *seq,
2771 unsigned long bucket;
2773 while (sk > (struct sock *)SEQ_START_TOKEN) {
2777 if (sock_net(sk) == seq_file_net(seq))
2782 sk = unix_from_bucket(seq, pos);
2787 bucket = get_bucket(*pos) + 1;
2788 *pos = set_bucket_offset(bucket, 1);
2789 } while (bucket < ARRAY_SIZE(unix_socket_table));
2794 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2795 __acquires(unix_table_lock)
2797 spin_lock(&unix_table_lock);
2800 return SEQ_START_TOKEN;
2802 if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table))
2805 return unix_next_socket(seq, NULL, pos);
2808 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2811 return unix_next_socket(seq, v, pos);
2814 static void unix_seq_stop(struct seq_file *seq, void *v)
2815 __releases(unix_table_lock)
2817 spin_unlock(&unix_table_lock);
2820 static int unix_seq_show(struct seq_file *seq, void *v)
2823 if (v == SEQ_START_TOKEN)
2824 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2828 struct unix_sock *u = unix_sk(s);
2831 seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu",
2833 refcount_read(&s->sk_refcnt),
2835 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2838 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2839 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2842 if (u->addr) { // under unix_table_lock here
2847 len = u->addr->len - sizeof(short);
2848 if (!UNIX_ABSTRACT(s))
2854 for ( ; i < len; i++)
2855 seq_putc(seq, u->addr->name->sun_path[i] ?:
2858 unix_state_unlock(s);
2859 seq_putc(seq, '\n');
2865 static const struct seq_operations unix_seq_ops = {
2866 .start = unix_seq_start,
2867 .next = unix_seq_next,
2868 .stop = unix_seq_stop,
2869 .show = unix_seq_show,
2873 static const struct net_proto_family unix_family_ops = {
2875 .create = unix_create,
2876 .owner = THIS_MODULE,
2880 static int __net_init unix_net_init(struct net *net)
2882 int error = -ENOMEM;
2884 net->unx.sysctl_max_dgram_qlen = 10;
2885 if (unix_sysctl_register(net))
2888 #ifdef CONFIG_PROC_FS
2889 if (!proc_create_net("unix", 0, net->proc_net, &unix_seq_ops,
2890 sizeof(struct seq_net_private))) {
2891 unix_sysctl_unregister(net);
2900 static void __net_exit unix_net_exit(struct net *net)
2902 unix_sysctl_unregister(net);
2903 remove_proc_entry("unix", net->proc_net);
2906 static struct pernet_operations unix_net_ops = {
2907 .init = unix_net_init,
2908 .exit = unix_net_exit,
2911 static int __init af_unix_init(void)
2915 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
2917 rc = proto_register(&unix_proto, 1);
2919 pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
2923 sock_register(&unix_family_ops);
2924 register_pernet_subsys(&unix_net_ops);
2929 static void __exit af_unix_exit(void)
2931 sock_unregister(PF_UNIX);
2932 proto_unregister(&unix_proto);
2933 unregister_pernet_subsys(&unix_net_ops);
2936 /* Earlier than device_initcall() so that other drivers invoking
2937 request_module() don't end up in a loop when modprobe tries
2938 to use a UNIX socket. But later than subsys_initcall() because
2939 we depend on stuff initialised there */
2940 fs_initcall(af_unix_init);
2941 module_exit(af_unix_exit);
2943 MODULE_LICENSE("GPL");
2944 MODULE_ALIAS_NETPROTO(PF_UNIX);