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.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 <asm/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>
121 struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
122 EXPORT_SYMBOL_GPL(unix_socket_table);
123 DEFINE_SPINLOCK(unix_table_lock);
124 EXPORT_SYMBOL_GPL(unix_table_lock);
125 static atomic_long_t unix_nr_socks;
128 static struct hlist_head *unix_sockets_unbound(void *addr)
130 unsigned long hash = (unsigned long)addr;
134 hash %= UNIX_HASH_SIZE;
135 return &unix_socket_table[UNIX_HASH_SIZE + hash];
138 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE)
140 #ifdef CONFIG_SECURITY_NETWORK
141 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
143 UNIXCB(skb).secid = scm->secid;
146 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
148 scm->secid = UNIXCB(skb).secid;
151 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
153 return (scm->secid == UNIXCB(skb).secid);
156 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
159 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
162 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
166 #endif /* CONFIG_SECURITY_NETWORK */
169 * SMP locking strategy:
170 * hash table is protected with spinlock unix_table_lock
171 * each socket state is protected by separate spin lock.
174 static inline unsigned int unix_hash_fold(__wsum n)
176 unsigned int hash = (__force unsigned int)csum_fold(n);
179 return hash&(UNIX_HASH_SIZE-1);
182 #define unix_peer(sk) (unix_sk(sk)->peer)
184 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
186 return unix_peer(osk) == sk;
189 static inline int unix_may_send(struct sock *sk, struct sock *osk)
191 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
194 static inline int unix_recvq_full(struct sock const *sk)
196 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
199 struct sock *unix_peer_get(struct sock *s)
207 unix_state_unlock(s);
210 EXPORT_SYMBOL_GPL(unix_peer_get);
212 static inline void unix_release_addr(struct unix_address *addr)
214 if (atomic_dec_and_test(&addr->refcnt))
219 * Check unix socket name:
220 * - should be not zero length.
221 * - if started by not zero, should be NULL terminated (FS object)
222 * - if started by zero, it is abstract name.
225 static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp)
227 if (len <= sizeof(short) || len > sizeof(*sunaddr))
229 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
231 if (sunaddr->sun_path[0]) {
233 * This may look like an off by one error but it is a bit more
234 * subtle. 108 is the longest valid AF_UNIX path for a binding.
235 * sun_path[108] doesn't as such exist. However in kernel space
236 * we are guaranteed that it is a valid memory location in our
237 * kernel address buffer.
239 ((char *)sunaddr)[len] = 0;
240 len = strlen(sunaddr->sun_path)+1+sizeof(short);
244 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
248 static void __unix_remove_socket(struct sock *sk)
250 sk_del_node_init(sk);
253 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
255 WARN_ON(!sk_unhashed(sk));
256 sk_add_node(sk, list);
259 static inline void unix_remove_socket(struct sock *sk)
261 spin_lock(&unix_table_lock);
262 __unix_remove_socket(sk);
263 spin_unlock(&unix_table_lock);
266 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
268 spin_lock(&unix_table_lock);
269 __unix_insert_socket(list, sk);
270 spin_unlock(&unix_table_lock);
273 static struct sock *__unix_find_socket_byname(struct net *net,
274 struct sockaddr_un *sunname,
275 int len, int type, unsigned int hash)
279 sk_for_each(s, &unix_socket_table[hash ^ type]) {
280 struct unix_sock *u = unix_sk(s);
282 if (!net_eq(sock_net(s), net))
285 if (u->addr->len == len &&
286 !memcmp(u->addr->name, sunname, len))
294 static inline struct sock *unix_find_socket_byname(struct net *net,
295 struct sockaddr_un *sunname,
301 spin_lock(&unix_table_lock);
302 s = __unix_find_socket_byname(net, sunname, len, type, hash);
305 spin_unlock(&unix_table_lock);
309 static struct sock *unix_find_socket_byinode(struct inode *i)
313 spin_lock(&unix_table_lock);
315 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
316 struct dentry *dentry = unix_sk(s)->path.dentry;
318 if (dentry && d_backing_inode(dentry) == i) {
325 spin_unlock(&unix_table_lock);
329 /* Support code for asymmetrically connected dgram sockets
331 * If a datagram socket is connected to a socket not itself connected
332 * to the first socket (eg, /dev/log), clients may only enqueue more
333 * messages if the present receive queue of the server socket is not
334 * "too large". This means there's a second writeability condition
335 * poll and sendmsg need to test. The dgram recv code will do a wake
336 * up on the peer_wait wait queue of a socket upon reception of a
337 * datagram which needs to be propagated to sleeping would-be writers
338 * since these might not have sent anything so far. This can't be
339 * accomplished via poll_wait because the lifetime of the server
340 * socket might be less than that of its clients if these break their
341 * association with it or if the server socket is closed while clients
342 * are still connected to it and there's no way to inform "a polling
343 * implementation" that it should let go of a certain wait queue
345 * In order to propagate a wake up, a wait_queue_t of the client
346 * socket is enqueued on the peer_wait queue of the server socket
347 * whose wake function does a wake_up on the ordinary client socket
348 * wait queue. This connection is established whenever a write (or
349 * poll for write) hit the flow control condition and broken when the
350 * association to the server socket is dissolved or after a wake up
354 static int unix_dgram_peer_wake_relay(wait_queue_t *q, unsigned mode, int flags,
358 wait_queue_head_t *u_sleep;
360 u = container_of(q, struct unix_sock, peer_wake);
362 __remove_wait_queue(&unix_sk(u->peer_wake.private)->peer_wait,
364 u->peer_wake.private = NULL;
366 /* relaying can only happen while the wq still exists */
367 u_sleep = sk_sleep(&u->sk);
369 wake_up_interruptible_poll(u_sleep, key);
374 static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)
376 struct unix_sock *u, *u_other;
380 u_other = unix_sk(other);
382 spin_lock(&u_other->peer_wait.lock);
384 if (!u->peer_wake.private) {
385 u->peer_wake.private = other;
386 __add_wait_queue(&u_other->peer_wait, &u->peer_wake);
391 spin_unlock(&u_other->peer_wait.lock);
395 static void unix_dgram_peer_wake_disconnect(struct sock *sk,
398 struct unix_sock *u, *u_other;
401 u_other = unix_sk(other);
402 spin_lock(&u_other->peer_wait.lock);
404 if (u->peer_wake.private == other) {
405 __remove_wait_queue(&u_other->peer_wait, &u->peer_wake);
406 u->peer_wake.private = NULL;
409 spin_unlock(&u_other->peer_wait.lock);
412 static void unix_dgram_peer_wake_disconnect_wakeup(struct sock *sk,
415 unix_dgram_peer_wake_disconnect(sk, other);
416 wake_up_interruptible_poll(sk_sleep(sk),
423 * - unix_peer(sk) == other
424 * - association is stable
426 static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
430 connected = unix_dgram_peer_wake_connect(sk, other);
432 if (unix_recvq_full(other))
436 unix_dgram_peer_wake_disconnect(sk, other);
441 static int unix_writable(const struct sock *sk)
443 return sk->sk_state != TCP_LISTEN &&
444 (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
447 static void unix_write_space(struct sock *sk)
449 struct socket_wq *wq;
452 if (unix_writable(sk)) {
453 wq = rcu_dereference(sk->sk_wq);
454 if (skwq_has_sleeper(wq))
455 wake_up_interruptible_sync_poll(&wq->wait,
456 POLLOUT | POLLWRNORM | POLLWRBAND);
457 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
462 /* When dgram socket disconnects (or changes its peer), we clear its receive
463 * queue of packets arrived from previous peer. First, it allows to do
464 * flow control based only on wmem_alloc; second, sk connected to peer
465 * may receive messages only from that peer. */
466 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
468 if (!skb_queue_empty(&sk->sk_receive_queue)) {
469 skb_queue_purge(&sk->sk_receive_queue);
470 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
472 /* If one link of bidirectional dgram pipe is disconnected,
473 * we signal error. Messages are lost. Do not make this,
474 * when peer was not connected to us.
476 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
477 other->sk_err = ECONNRESET;
478 other->sk_error_report(other);
483 static void unix_sock_destructor(struct sock *sk)
485 struct unix_sock *u = unix_sk(sk);
487 skb_queue_purge(&sk->sk_receive_queue);
489 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
490 WARN_ON(!sk_unhashed(sk));
491 WARN_ON(sk->sk_socket);
492 if (!sock_flag(sk, SOCK_DEAD)) {
493 pr_info("Attempt to release alive unix socket: %p\n", sk);
498 unix_release_addr(u->addr);
500 atomic_long_dec(&unix_nr_socks);
502 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
504 #ifdef UNIX_REFCNT_DEBUG
505 pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk,
506 atomic_long_read(&unix_nr_socks));
510 static void unix_release_sock(struct sock *sk, int embrion)
512 struct unix_sock *u = unix_sk(sk);
518 unix_remove_socket(sk);
523 sk->sk_shutdown = SHUTDOWN_MASK;
525 u->path.dentry = NULL;
527 state = sk->sk_state;
528 sk->sk_state = TCP_CLOSE;
529 unix_state_unlock(sk);
531 wake_up_interruptible_all(&u->peer_wait);
533 skpair = unix_peer(sk);
535 if (skpair != NULL) {
536 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
537 unix_state_lock(skpair);
539 skpair->sk_shutdown = SHUTDOWN_MASK;
540 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
541 skpair->sk_err = ECONNRESET;
542 unix_state_unlock(skpair);
543 skpair->sk_state_change(skpair);
544 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
547 unix_dgram_peer_wake_disconnect(sk, skpair);
548 sock_put(skpair); /* It may now die */
549 unix_peer(sk) = NULL;
552 /* Try to flush out this socket. Throw out buffers at least */
554 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
555 if (state == TCP_LISTEN)
556 unix_release_sock(skb->sk, 1);
557 /* passed fds are erased in the kfree_skb hook */
558 UNIXCB(skb).consumed = skb->len;
567 /* ---- Socket is dead now and most probably destroyed ---- */
570 * Fixme: BSD difference: In BSD all sockets connected to us get
571 * ECONNRESET and we die on the spot. In Linux we behave
572 * like files and pipes do and wait for the last
575 * Can't we simply set sock->err?
577 * What the above comment does talk about? --ANK(980817)
580 if (unix_tot_inflight)
581 unix_gc(); /* Garbage collect fds */
584 static void init_peercred(struct sock *sk)
586 put_pid(sk->sk_peer_pid);
587 if (sk->sk_peer_cred)
588 put_cred(sk->sk_peer_cred);
589 sk->sk_peer_pid = get_pid(task_tgid(current));
590 sk->sk_peer_cred = get_current_cred();
593 static void copy_peercred(struct sock *sk, struct sock *peersk)
595 put_pid(sk->sk_peer_pid);
596 if (sk->sk_peer_cred)
597 put_cred(sk->sk_peer_cred);
598 sk->sk_peer_pid = get_pid(peersk->sk_peer_pid);
599 sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
602 static int unix_listen(struct socket *sock, int backlog)
605 struct sock *sk = sock->sk;
606 struct unix_sock *u = unix_sk(sk);
607 struct pid *old_pid = NULL;
610 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
611 goto out; /* Only stream/seqpacket sockets accept */
614 goto out; /* No listens on an unbound socket */
616 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
618 if (backlog > sk->sk_max_ack_backlog)
619 wake_up_interruptible_all(&u->peer_wait);
620 sk->sk_max_ack_backlog = backlog;
621 sk->sk_state = TCP_LISTEN;
622 /* set credentials so connect can copy them */
627 unix_state_unlock(sk);
633 static int unix_release(struct socket *);
634 static int unix_bind(struct socket *, struct sockaddr *, int);
635 static int unix_stream_connect(struct socket *, struct sockaddr *,
636 int addr_len, int flags);
637 static int unix_socketpair(struct socket *, struct socket *);
638 static int unix_accept(struct socket *, struct socket *, int);
639 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
640 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
641 static unsigned int unix_dgram_poll(struct file *, struct socket *,
643 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
644 static int unix_shutdown(struct socket *, int);
645 static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t);
646 static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int);
647 static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset,
648 size_t size, int flags);
649 static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos,
650 struct pipe_inode_info *, size_t size,
652 static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
653 static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
654 static int unix_dgram_connect(struct socket *, struct sockaddr *,
656 static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t);
657 static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t,
660 static int unix_set_peek_off(struct sock *sk, int val)
662 struct unix_sock *u = unix_sk(sk);
664 if (mutex_lock_interruptible(&u->readlock))
667 sk->sk_peek_off = val;
668 mutex_unlock(&u->readlock);
674 static const struct proto_ops unix_stream_ops = {
676 .owner = THIS_MODULE,
677 .release = unix_release,
679 .connect = unix_stream_connect,
680 .socketpair = unix_socketpair,
681 .accept = unix_accept,
682 .getname = unix_getname,
685 .listen = unix_listen,
686 .shutdown = unix_shutdown,
687 .setsockopt = sock_no_setsockopt,
688 .getsockopt = sock_no_getsockopt,
689 .sendmsg = unix_stream_sendmsg,
690 .recvmsg = unix_stream_recvmsg,
691 .mmap = sock_no_mmap,
692 .sendpage = unix_stream_sendpage,
693 .splice_read = unix_stream_splice_read,
694 .set_peek_off = unix_set_peek_off,
697 static const struct proto_ops unix_dgram_ops = {
699 .owner = THIS_MODULE,
700 .release = unix_release,
702 .connect = unix_dgram_connect,
703 .socketpair = unix_socketpair,
704 .accept = sock_no_accept,
705 .getname = unix_getname,
706 .poll = unix_dgram_poll,
708 .listen = sock_no_listen,
709 .shutdown = unix_shutdown,
710 .setsockopt = sock_no_setsockopt,
711 .getsockopt = sock_no_getsockopt,
712 .sendmsg = unix_dgram_sendmsg,
713 .recvmsg = unix_dgram_recvmsg,
714 .mmap = sock_no_mmap,
715 .sendpage = sock_no_sendpage,
716 .set_peek_off = unix_set_peek_off,
719 static const struct proto_ops unix_seqpacket_ops = {
721 .owner = THIS_MODULE,
722 .release = unix_release,
724 .connect = unix_stream_connect,
725 .socketpair = unix_socketpair,
726 .accept = unix_accept,
727 .getname = unix_getname,
728 .poll = unix_dgram_poll,
730 .listen = unix_listen,
731 .shutdown = unix_shutdown,
732 .setsockopt = sock_no_setsockopt,
733 .getsockopt = sock_no_getsockopt,
734 .sendmsg = unix_seqpacket_sendmsg,
735 .recvmsg = unix_seqpacket_recvmsg,
736 .mmap = sock_no_mmap,
737 .sendpage = sock_no_sendpage,
738 .set_peek_off = unix_set_peek_off,
741 static struct proto unix_proto = {
743 .owner = THIS_MODULE,
744 .obj_size = sizeof(struct unix_sock),
748 * AF_UNIX sockets do not interact with hardware, hence they
749 * dont trigger interrupts - so it's safe for them to have
750 * bh-unsafe locking for their sk_receive_queue.lock. Split off
751 * this special lock-class by reinitializing the spinlock key:
753 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
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);
769 lockdep_set_class(&sk->sk_receive_queue.lock,
770 &af_unix_sk_receive_queue_lock_key);
772 sk->sk_write_space = unix_write_space;
773 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
774 sk->sk_destruct = unix_sock_destructor;
776 u->path.dentry = NULL;
778 spin_lock_init(&u->lock);
779 atomic_long_set(&u->inflight, 0);
780 INIT_LIST_HEAD(&u->link);
781 mutex_init(&u->readlock); /* single task reading 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;
815 sock->ops = &unix_dgram_ops;
818 sock->ops = &unix_seqpacket_ops;
821 return -ESOCKTNOSUPPORT;
824 return unix_create1(net, sock, kern) ? 0 : -ENOMEM;
827 static int unix_release(struct socket *sock)
829 struct sock *sk = sock->sk;
834 unix_release_sock(sk, 0);
840 static int unix_autobind(struct socket *sock)
842 struct sock *sk = sock->sk;
843 struct net *net = sock_net(sk);
844 struct unix_sock *u = unix_sk(sk);
845 static u32 ordernum = 1;
846 struct unix_address *addr;
848 unsigned int retries = 0;
850 err = mutex_lock_interruptible(&u->readlock);
859 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
863 addr->name->sun_family = AF_UNIX;
864 atomic_set(&addr->refcnt, 1);
867 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
868 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
870 spin_lock(&unix_table_lock);
871 ordernum = (ordernum+1)&0xFFFFF;
873 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
875 spin_unlock(&unix_table_lock);
877 * __unix_find_socket_byname() may take long time if many names
878 * are already in use.
881 /* Give up if all names seems to be in use. */
882 if (retries++ == 0xFFFFF) {
889 addr->hash ^= sk->sk_type;
891 __unix_remove_socket(sk);
893 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
894 spin_unlock(&unix_table_lock);
897 out: mutex_unlock(&u->readlock);
901 static struct sock *unix_find_other(struct net *net,
902 struct sockaddr_un *sunname, int len,
903 int type, unsigned int hash, int *error)
909 if (sunname->sun_path[0]) {
911 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
914 inode = d_backing_inode(path.dentry);
915 err = inode_permission(inode, MAY_WRITE);
920 if (!S_ISSOCK(inode->i_mode))
922 u = unix_find_socket_byinode(inode);
926 if (u->sk_type == type)
932 if (u->sk_type != type) {
938 u = unix_find_socket_byname(net, sunname, len, type, hash);
940 struct dentry *dentry;
941 dentry = unix_sk(u)->path.dentry;
943 touch_atime(&unix_sk(u)->path);
956 static int unix_mknod(struct dentry *dentry, struct path *path, umode_t mode,
961 err = security_path_mknod(path, dentry, mode, 0);
963 err = vfs_mknod(d_inode(path->dentry), dentry, mode, 0);
965 res->mnt = mntget(path->mnt);
966 res->dentry = dget(dentry);
973 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
975 struct sock *sk = sock->sk;
976 struct net *net = sock_net(sk);
977 struct unix_sock *u = unix_sk(sk);
978 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
979 char *sun_path = sunaddr->sun_path;
982 struct unix_address *addr;
983 struct hlist_head *list;
985 struct dentry *dentry;
988 if (sunaddr->sun_family != AF_UNIX)
991 if (addr_len == sizeof(short)) {
992 err = unix_autobind(sock);
996 err = unix_mkname(sunaddr, addr_len, &hash);
1004 /* Get the parent directory, calculate the hash for last
1007 dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
1009 if (IS_ERR(dentry)) {
1010 /* delay report until after 'already bound' check */
1011 name_err = PTR_ERR(dentry);
1016 err = mutex_lock_interruptible(&u->readlock);
1025 err = name_err == -EEXIST ? -EADDRINUSE : name_err;
1030 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
1034 memcpy(addr->name, sunaddr, addr_len);
1035 addr->len = addr_len;
1036 addr->hash = hash ^ sk->sk_type;
1037 atomic_set(&addr->refcnt, 1);
1041 umode_t mode = S_IFSOCK |
1042 (SOCK_INODE(sock)->i_mode & ~current_umask());
1043 err = unix_mknod(dentry, &path, mode, &u_path);
1047 unix_release_addr(addr);
1050 addr->hash = UNIX_HASH_SIZE;
1051 hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
1052 spin_lock(&unix_table_lock);
1054 list = &unix_socket_table[hash];
1056 spin_lock(&unix_table_lock);
1058 if (__unix_find_socket_byname(net, sunaddr, addr_len,
1059 sk->sk_type, hash)) {
1060 unix_release_addr(addr);
1064 list = &unix_socket_table[addr->hash];
1068 __unix_remove_socket(sk);
1070 __unix_insert_socket(list, sk);
1073 spin_unlock(&unix_table_lock);
1075 mutex_unlock(&u->readlock);
1078 done_path_create(&path, dentry);
1084 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
1086 if (unlikely(sk1 == sk2) || !sk2) {
1087 unix_state_lock(sk1);
1091 unix_state_lock(sk1);
1092 unix_state_lock_nested(sk2);
1094 unix_state_lock(sk2);
1095 unix_state_lock_nested(sk1);
1099 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
1101 if (unlikely(sk1 == sk2) || !sk2) {
1102 unix_state_unlock(sk1);
1105 unix_state_unlock(sk1);
1106 unix_state_unlock(sk2);
1109 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
1110 int alen, int flags)
1112 struct sock *sk = sock->sk;
1113 struct net *net = sock_net(sk);
1114 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
1119 if (addr->sa_family != AF_UNSPEC) {
1120 err = unix_mkname(sunaddr, alen, &hash);
1125 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
1126 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
1130 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
1134 unix_state_double_lock(sk, other);
1136 /* Apparently VFS overslept socket death. Retry. */
1137 if (sock_flag(other, SOCK_DEAD)) {
1138 unix_state_double_unlock(sk, other);
1144 if (!unix_may_send(sk, other))
1147 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1153 * 1003.1g breaking connected state with AF_UNSPEC
1156 unix_state_double_lock(sk, other);
1160 * If it was connected, reconnect.
1162 if (unix_peer(sk)) {
1163 struct sock *old_peer = unix_peer(sk);
1164 unix_peer(sk) = other;
1165 unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer);
1167 unix_state_double_unlock(sk, other);
1169 if (other != old_peer)
1170 unix_dgram_disconnected(sk, old_peer);
1173 unix_peer(sk) = other;
1174 unix_state_double_unlock(sk, other);
1179 unix_state_double_unlock(sk, other);
1185 static long unix_wait_for_peer(struct sock *other, long timeo)
1187 struct unix_sock *u = unix_sk(other);
1191 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1193 sched = !sock_flag(other, SOCK_DEAD) &&
1194 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1195 unix_recvq_full(other);
1197 unix_state_unlock(other);
1200 timeo = schedule_timeout(timeo);
1202 finish_wait(&u->peer_wait, &wait);
1206 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1207 int addr_len, int flags)
1209 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
1210 struct sock *sk = sock->sk;
1211 struct net *net = sock_net(sk);
1212 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1213 struct sock *newsk = NULL;
1214 struct sock *other = NULL;
1215 struct sk_buff *skb = NULL;
1221 err = unix_mkname(sunaddr, addr_len, &hash);
1226 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1227 (err = unix_autobind(sock)) != 0)
1230 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1232 /* First of all allocate resources.
1233 If we will make it after state is locked,
1234 we will have to recheck all again in any case.
1239 /* create new sock for complete connection */
1240 newsk = unix_create1(sock_net(sk), NULL, 0);
1244 /* Allocate skb for sending to listening sock */
1245 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1250 /* Find listening sock. */
1251 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1255 /* Latch state of peer */
1256 unix_state_lock(other);
1258 /* Apparently VFS overslept socket death. Retry. */
1259 if (sock_flag(other, SOCK_DEAD)) {
1260 unix_state_unlock(other);
1265 err = -ECONNREFUSED;
1266 if (other->sk_state != TCP_LISTEN)
1268 if (other->sk_shutdown & RCV_SHUTDOWN)
1271 if (unix_recvq_full(other)) {
1276 timeo = unix_wait_for_peer(other, timeo);
1278 err = sock_intr_errno(timeo);
1279 if (signal_pending(current))
1287 It is tricky place. We need to grab our state lock and cannot
1288 drop lock on peer. It is dangerous because deadlock is
1289 possible. Connect to self case and simultaneous
1290 attempt to connect are eliminated by checking socket
1291 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1292 check this before attempt to grab lock.
1294 Well, and we have to recheck the state after socket locked.
1300 /* This is ok... continue with connect */
1302 case TCP_ESTABLISHED:
1303 /* Socket is already connected */
1311 unix_state_lock_nested(sk);
1313 if (sk->sk_state != st) {
1314 unix_state_unlock(sk);
1315 unix_state_unlock(other);
1320 err = security_unix_stream_connect(sk, other, newsk);
1322 unix_state_unlock(sk);
1326 /* The way is open! Fastly set all the necessary fields... */
1329 unix_peer(newsk) = sk;
1330 newsk->sk_state = TCP_ESTABLISHED;
1331 newsk->sk_type = sk->sk_type;
1332 init_peercred(newsk);
1333 newu = unix_sk(newsk);
1334 RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq);
1335 otheru = unix_sk(other);
1337 /* copy address information from listening to new sock*/
1339 atomic_inc(&otheru->addr->refcnt);
1340 newu->addr = otheru->addr;
1342 if (otheru->path.dentry) {
1343 path_get(&otheru->path);
1344 newu->path = otheru->path;
1347 /* Set credentials */
1348 copy_peercred(sk, other);
1350 sock->state = SS_CONNECTED;
1351 sk->sk_state = TCP_ESTABLISHED;
1354 smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */
1355 unix_peer(sk) = newsk;
1357 unix_state_unlock(sk);
1359 /* take ten and and send info to listening sock */
1360 spin_lock(&other->sk_receive_queue.lock);
1361 __skb_queue_tail(&other->sk_receive_queue, skb);
1362 spin_unlock(&other->sk_receive_queue.lock);
1363 unix_state_unlock(other);
1364 other->sk_data_ready(other);
1370 unix_state_unlock(other);
1375 unix_release_sock(newsk, 0);
1381 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1383 struct sock *ska = socka->sk, *skb = sockb->sk;
1385 /* Join our sockets back to back */
1388 unix_peer(ska) = skb;
1389 unix_peer(skb) = ska;
1393 if (ska->sk_type != SOCK_DGRAM) {
1394 ska->sk_state = TCP_ESTABLISHED;
1395 skb->sk_state = TCP_ESTABLISHED;
1396 socka->state = SS_CONNECTED;
1397 sockb->state = SS_CONNECTED;
1402 static void unix_sock_inherit_flags(const struct socket *old,
1405 if (test_bit(SOCK_PASSCRED, &old->flags))
1406 set_bit(SOCK_PASSCRED, &new->flags);
1407 if (test_bit(SOCK_PASSSEC, &old->flags))
1408 set_bit(SOCK_PASSSEC, &new->flags);
1411 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1413 struct sock *sk = sock->sk;
1415 struct sk_buff *skb;
1419 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
1423 if (sk->sk_state != TCP_LISTEN)
1426 /* If socket state is TCP_LISTEN it cannot change (for now...),
1427 * so that no locks are necessary.
1430 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1432 /* This means receive shutdown. */
1439 skb_free_datagram(sk, skb);
1440 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1442 /* attach accepted sock to socket */
1443 unix_state_lock(tsk);
1444 newsock->state = SS_CONNECTED;
1445 unix_sock_inherit_flags(sock, newsock);
1446 sock_graft(tsk, newsock);
1447 unix_state_unlock(tsk);
1455 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1457 struct sock *sk = sock->sk;
1458 struct unix_sock *u;
1459 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
1463 sk = unix_peer_get(sk);
1474 unix_state_lock(sk);
1476 sunaddr->sun_family = AF_UNIX;
1477 sunaddr->sun_path[0] = 0;
1478 *uaddr_len = sizeof(short);
1480 struct unix_address *addr = u->addr;
1482 *uaddr_len = addr->len;
1483 memcpy(sunaddr, addr->name, *uaddr_len);
1485 unix_state_unlock(sk);
1491 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1495 scm->fp = UNIXCB(skb).fp;
1496 UNIXCB(skb).fp = NULL;
1498 for (i = scm->fp->count-1; i >= 0; i--)
1499 unix_notinflight(scm->fp->user, scm->fp->fp[i]);
1502 static void unix_destruct_scm(struct sk_buff *skb)
1504 struct scm_cookie scm;
1505 memset(&scm, 0, sizeof(scm));
1506 scm.pid = UNIXCB(skb).pid;
1508 unix_detach_fds(&scm, skb);
1510 /* Alas, it calls VFS */
1511 /* So fscking what? fput() had been SMP-safe since the last Summer */
1517 * The "user->unix_inflight" variable is protected by the garbage
1518 * collection lock, and we just read it locklessly here. If you go
1519 * over the limit, there might be a tiny race in actually noticing
1520 * it across threads. Tough.
1522 static inline bool too_many_unix_fds(struct task_struct *p)
1524 struct user_struct *user = current_user();
1526 if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
1527 return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
1531 #define MAX_RECURSION_LEVEL 4
1533 static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1536 unsigned char max_level = 0;
1538 if (too_many_unix_fds(current))
1539 return -ETOOMANYREFS;
1541 for (i = scm->fp->count - 1; i >= 0; i--) {
1542 struct sock *sk = unix_get_socket(scm->fp->fp[i]);
1545 max_level = max(max_level,
1546 unix_sk(sk)->recursion_level);
1548 if (unlikely(max_level > MAX_RECURSION_LEVEL))
1549 return -ETOOMANYREFS;
1552 * Need to duplicate file references for the sake of garbage
1553 * collection. Otherwise a socket in the fps might become a
1554 * candidate for GC while the skb is not yet queued.
1556 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1557 if (!UNIXCB(skb).fp)
1560 for (i = scm->fp->count - 1; i >= 0; i--)
1561 unix_inflight(scm->fp->user, scm->fp->fp[i]);
1565 static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
1569 UNIXCB(skb).pid = get_pid(scm->pid);
1570 UNIXCB(skb).uid = scm->creds.uid;
1571 UNIXCB(skb).gid = scm->creds.gid;
1572 UNIXCB(skb).fp = NULL;
1573 unix_get_secdata(scm, skb);
1574 if (scm->fp && send_fds)
1575 err = unix_attach_fds(scm, skb);
1577 skb->destructor = unix_destruct_scm;
1581 static bool unix_passcred_enabled(const struct socket *sock,
1582 const struct sock *other)
1584 return test_bit(SOCK_PASSCRED, &sock->flags) ||
1585 !other->sk_socket ||
1586 test_bit(SOCK_PASSCRED, &other->sk_socket->flags);
1590 * Some apps rely on write() giving SCM_CREDENTIALS
1591 * We include credentials if source or destination socket
1592 * asserted SOCK_PASSCRED.
1594 static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
1595 const struct sock *other)
1597 if (UNIXCB(skb).pid)
1599 if (unix_passcred_enabled(sock, other)) {
1600 UNIXCB(skb).pid = get_pid(task_tgid(current));
1601 current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
1605 static int maybe_init_creds(struct scm_cookie *scm,
1606 struct socket *socket,
1607 const struct sock *other)
1610 struct msghdr msg = { .msg_controllen = 0 };
1612 err = scm_send(socket, &msg, scm, false);
1616 if (unix_passcred_enabled(socket, other)) {
1617 scm->pid = get_pid(task_tgid(current));
1618 current_uid_gid(&scm->creds.uid, &scm->creds.gid);
1623 static bool unix_skb_scm_eq(struct sk_buff *skb,
1624 struct scm_cookie *scm)
1626 const struct unix_skb_parms *u = &UNIXCB(skb);
1628 return u->pid == scm->pid &&
1629 uid_eq(u->uid, scm->creds.uid) &&
1630 gid_eq(u->gid, scm->creds.gid) &&
1631 unix_secdata_eq(scm, skb);
1635 * Send AF_UNIX data.
1638 static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1641 struct sock *sk = sock->sk;
1642 struct net *net = sock_net(sk);
1643 struct unix_sock *u = unix_sk(sk);
1644 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
1645 struct sock *other = NULL;
1646 int namelen = 0; /* fake GCC */
1649 struct sk_buff *skb;
1651 struct scm_cookie scm;
1657 err = scm_send(sock, msg, &scm, false);
1662 if (msg->msg_flags&MSG_OOB)
1665 if (msg->msg_namelen) {
1666 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1673 other = unix_peer_get(sk);
1678 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1679 && (err = unix_autobind(sock)) != 0)
1683 if (len > sk->sk_sndbuf - 32)
1686 if (len > SKB_MAX_ALLOC) {
1687 data_len = min_t(size_t,
1688 len - SKB_MAX_ALLOC,
1689 MAX_SKB_FRAGS * PAGE_SIZE);
1690 data_len = PAGE_ALIGN(data_len);
1692 BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE);
1695 skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
1696 msg->msg_flags & MSG_DONTWAIT, &err,
1697 PAGE_ALLOC_COSTLY_ORDER);
1701 err = unix_scm_to_skb(&scm, skb, true);
1704 max_level = err + 1;
1706 skb_put(skb, len - data_len);
1707 skb->data_len = data_len;
1709 err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
1713 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1718 if (sunaddr == NULL)
1721 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1727 if (sk_filter(other, skb) < 0) {
1728 /* Toss the packet but do not return any error to the sender */
1734 unix_state_lock(other);
1737 if (!unix_may_send(sk, other))
1740 if (unlikely(sock_flag(other, SOCK_DEAD))) {
1742 * Check with 1003.1g - what should
1745 unix_state_unlock(other);
1749 unix_state_lock(sk);
1752 if (unix_peer(sk) == other) {
1753 unix_peer(sk) = NULL;
1754 unix_dgram_peer_wake_disconnect_wakeup(sk, other);
1756 unix_state_unlock(sk);
1758 unix_dgram_disconnected(sk, other);
1760 err = -ECONNREFUSED;
1762 unix_state_unlock(sk);
1772 if (other->sk_shutdown & RCV_SHUTDOWN)
1775 if (sk->sk_type != SOCK_SEQPACKET) {
1776 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1781 if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {
1783 timeo = unix_wait_for_peer(other, timeo);
1785 err = sock_intr_errno(timeo);
1786 if (signal_pending(current))
1793 unix_state_unlock(other);
1794 unix_state_double_lock(sk, other);
1797 if (unix_peer(sk) != other ||
1798 unix_dgram_peer_wake_me(sk, other)) {
1806 goto restart_locked;
1810 if (unlikely(sk_locked))
1811 unix_state_unlock(sk);
1813 if (sock_flag(other, SOCK_RCVTSTAMP))
1814 __net_timestamp(skb);
1815 maybe_add_creds(skb, sock, other);
1816 skb_queue_tail(&other->sk_receive_queue, skb);
1817 if (max_level > unix_sk(other)->recursion_level)
1818 unix_sk(other)->recursion_level = max_level;
1819 unix_state_unlock(other);
1820 other->sk_data_ready(other);
1827 unix_state_unlock(sk);
1828 unix_state_unlock(other);
1838 /* We use paged skbs for stream sockets, and limit occupancy to 32768
1839 * bytes, and a minimun of a full page.
1841 #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768))
1843 static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1846 struct sock *sk = sock->sk;
1847 struct sock *other = NULL;
1849 struct sk_buff *skb;
1851 struct scm_cookie scm;
1852 bool fds_sent = false;
1857 err = scm_send(sock, msg, &scm, false);
1862 if (msg->msg_flags&MSG_OOB)
1865 if (msg->msg_namelen) {
1866 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1870 other = unix_peer(sk);
1875 if (sk->sk_shutdown & SEND_SHUTDOWN)
1878 while (sent < len) {
1881 /* Keep two messages in the pipe so it schedules better */
1882 size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
1884 /* allow fallback to order-0 allocations */
1885 size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
1887 data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
1889 data_len = min_t(size_t, size, PAGE_ALIGN(data_len));
1891 skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
1892 msg->msg_flags & MSG_DONTWAIT, &err,
1893 get_order(UNIX_SKB_FRAGS_SZ));
1897 /* Only send the fds in the first buffer */
1898 err = unix_scm_to_skb(&scm, skb, !fds_sent);
1903 max_level = err + 1;
1906 skb_put(skb, size - data_len);
1907 skb->data_len = data_len;
1909 err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size);
1915 unix_state_lock(other);
1917 if (sock_flag(other, SOCK_DEAD) ||
1918 (other->sk_shutdown & RCV_SHUTDOWN))
1921 maybe_add_creds(skb, sock, other);
1922 skb_queue_tail(&other->sk_receive_queue, skb);
1923 if (max_level > unix_sk(other)->recursion_level)
1924 unix_sk(other)->recursion_level = max_level;
1925 unix_state_unlock(other);
1926 other->sk_data_ready(other);
1935 unix_state_unlock(other);
1938 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1939 send_sig(SIGPIPE, current, 0);
1943 return sent ? : err;
1946 static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
1947 int offset, size_t size, int flags)
1950 bool send_sigpipe = false;
1951 bool init_scm = true;
1952 struct scm_cookie scm;
1953 struct sock *other, *sk = socket->sk;
1954 struct sk_buff *skb, *newskb = NULL, *tail = NULL;
1956 if (flags & MSG_OOB)
1959 other = unix_peer(sk);
1960 if (!other || sk->sk_state != TCP_ESTABLISHED)
1965 unix_state_unlock(other);
1966 mutex_unlock(&unix_sk(other)->readlock);
1967 newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
1973 /* we must acquire readlock as we modify already present
1974 * skbs in the sk_receive_queue and mess with skb->len
1976 err = mutex_lock_interruptible(&unix_sk(other)->readlock);
1978 err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
1982 if (sk->sk_shutdown & SEND_SHUTDOWN) {
1984 send_sigpipe = true;
1988 unix_state_lock(other);
1990 if (sock_flag(other, SOCK_DEAD) ||
1991 other->sk_shutdown & RCV_SHUTDOWN) {
1993 send_sigpipe = true;
1994 goto err_state_unlock;
1998 err = maybe_init_creds(&scm, socket, other);
2000 goto err_state_unlock;
2004 skb = skb_peek_tail(&other->sk_receive_queue);
2005 if (tail && tail == skb) {
2007 } else if (!skb || !unix_skb_scm_eq(skb, &scm)) {
2014 } else if (newskb) {
2015 /* this is fast path, we don't necessarily need to
2016 * call to kfree_skb even though with newskb == NULL
2017 * this - does no harm
2019 consume_skb(newskb);
2023 if (skb_append_pagefrags(skb, page, offset, size)) {
2029 skb->data_len += size;
2030 skb->truesize += size;
2031 atomic_add(size, &sk->sk_wmem_alloc);
2034 err = unix_scm_to_skb(&scm, skb, false);
2036 goto err_state_unlock;
2037 spin_lock(&other->sk_receive_queue.lock);
2038 __skb_queue_tail(&other->sk_receive_queue, newskb);
2039 spin_unlock(&other->sk_receive_queue.lock);
2042 unix_state_unlock(other);
2043 mutex_unlock(&unix_sk(other)->readlock);
2045 other->sk_data_ready(other);
2050 unix_state_unlock(other);
2052 mutex_unlock(&unix_sk(other)->readlock);
2055 if (send_sigpipe && !(flags & MSG_NOSIGNAL))
2056 send_sig(SIGPIPE, current, 0);
2062 static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg,
2066 struct sock *sk = sock->sk;
2068 err = sock_error(sk);
2072 if (sk->sk_state != TCP_ESTABLISHED)
2075 if (msg->msg_namelen)
2076 msg->msg_namelen = 0;
2078 return unix_dgram_sendmsg(sock, msg, len);
2081 static int unix_seqpacket_recvmsg(struct socket *sock, struct msghdr *msg,
2082 size_t size, int flags)
2084 struct sock *sk = sock->sk;
2086 if (sk->sk_state != TCP_ESTABLISHED)
2089 return unix_dgram_recvmsg(sock, msg, size, flags);
2092 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
2094 struct unix_sock *u = unix_sk(sk);
2097 msg->msg_namelen = u->addr->len;
2098 memcpy(msg->msg_name, u->addr->name, u->addr->len);
2102 static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
2103 size_t size, int flags)
2105 struct scm_cookie scm;
2106 struct sock *sk = sock->sk;
2107 struct unix_sock *u = unix_sk(sk);
2108 struct sk_buff *skb, *last;
2117 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2120 mutex_lock(&u->readlock);
2122 skip = sk_peek_offset(sk, flags);
2123 skb = __skb_try_recv_datagram(sk, flags, &peeked, &skip, &err,
2128 mutex_unlock(&u->readlock);
2133 !__skb_wait_for_more_packets(sk, &err, &timeo, last));
2135 if (!skb) { /* implies readlock unlocked */
2136 unix_state_lock(sk);
2137 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
2138 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
2139 (sk->sk_shutdown & RCV_SHUTDOWN))
2141 unix_state_unlock(sk);
2145 if (wq_has_sleeper(&u->peer_wait))
2146 wake_up_interruptible_sync_poll(&u->peer_wait,
2147 POLLOUT | POLLWRNORM |
2151 unix_copy_addr(msg, skb->sk);
2153 if (size > skb->len - skip)
2154 size = skb->len - skip;
2155 else if (size < skb->len - skip)
2156 msg->msg_flags |= MSG_TRUNC;
2158 err = skb_copy_datagram_msg(skb, skip, msg, size);
2162 if (sock_flag(sk, SOCK_RCVTSTAMP))
2163 __sock_recv_timestamp(msg, sk, skb);
2165 memset(&scm, 0, sizeof(scm));
2167 scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
2168 unix_set_secdata(&scm, skb);
2170 if (!(flags & MSG_PEEK)) {
2172 unix_detach_fds(&scm, skb);
2174 sk_peek_offset_bwd(sk, skb->len);
2176 /* It is questionable: on PEEK we could:
2177 - do not return fds - good, but too simple 8)
2178 - return fds, and do not return them on read (old strategy,
2180 - clone fds (I chose it for now, it is the most universal
2183 POSIX 1003.1g does not actually define this clearly
2184 at all. POSIX 1003.1g doesn't define a lot of things
2189 sk_peek_offset_fwd(sk, size);
2192 scm.fp = scm_fp_dup(UNIXCB(skb).fp);
2194 err = (flags & MSG_TRUNC) ? skb->len - skip : size;
2196 scm_recv(sock, msg, &scm, flags);
2199 skb_free_datagram(sk, skb);
2200 mutex_unlock(&u->readlock);
2206 * Sleep until more data has arrived. But check for races..
2208 static long unix_stream_data_wait(struct sock *sk, long timeo,
2209 struct sk_buff *last, unsigned int last_len)
2211 struct sk_buff *tail;
2214 unix_state_lock(sk);
2217 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2219 tail = skb_peek_tail(&sk->sk_receive_queue);
2221 (tail && tail->len != last_len) ||
2223 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2224 signal_pending(current) ||
2228 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2229 unix_state_unlock(sk);
2230 timeo = freezable_schedule_timeout(timeo);
2231 unix_state_lock(sk);
2233 if (sock_flag(sk, SOCK_DEAD))
2236 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2239 finish_wait(sk_sleep(sk), &wait);
2240 unix_state_unlock(sk);
2244 static unsigned int unix_skb_len(const struct sk_buff *skb)
2246 return skb->len - UNIXCB(skb).consumed;
2249 struct unix_stream_read_state {
2250 int (*recv_actor)(struct sk_buff *, int, int,
2251 struct unix_stream_read_state *);
2252 struct socket *socket;
2254 struct pipe_inode_info *pipe;
2257 unsigned int splice_flags;
2260 static int unix_stream_read_generic(struct unix_stream_read_state *state)
2262 struct scm_cookie scm;
2263 struct socket *sock = state->socket;
2264 struct sock *sk = sock->sk;
2265 struct unix_sock *u = unix_sk(sk);
2267 int flags = state->flags;
2268 int noblock = flags & MSG_DONTWAIT;
2269 bool check_creds = false;
2274 size_t size = state->size;
2275 unsigned int last_len;
2278 if (sk->sk_state != TCP_ESTABLISHED)
2282 if (flags & MSG_OOB)
2285 target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
2286 timeo = sock_rcvtimeo(sk, noblock);
2288 memset(&scm, 0, sizeof(scm));
2290 /* Lock the socket to prevent queue disordering
2291 * while sleeps in memcpy_tomsg
2293 mutex_lock(&u->readlock);
2295 if (flags & MSG_PEEK)
2296 skip = sk_peek_offset(sk, flags);
2303 struct sk_buff *skb, *last;
2305 unix_state_lock(sk);
2306 if (sock_flag(sk, SOCK_DEAD)) {
2310 last = skb = skb_peek(&sk->sk_receive_queue);
2311 last_len = last ? last->len : 0;
2314 unix_sk(sk)->recursion_level = 0;
2315 if (copied >= target)
2319 * POSIX 1003.1g mandates this order.
2322 err = sock_error(sk);
2325 if (sk->sk_shutdown & RCV_SHUTDOWN)
2328 unix_state_unlock(sk);
2332 mutex_unlock(&u->readlock);
2334 timeo = unix_stream_data_wait(sk, timeo, last,
2337 if (signal_pending(current)) {
2338 err = sock_intr_errno(timeo);
2343 mutex_lock(&u->readlock);
2346 unix_state_unlock(sk);
2350 while (skip >= unix_skb_len(skb)) {
2351 skip -= unix_skb_len(skb);
2353 last_len = skb->len;
2354 skb = skb_peek_next(skb, &sk->sk_receive_queue);
2359 unix_state_unlock(sk);
2362 /* Never glue messages from different writers */
2363 if (!unix_skb_scm_eq(skb, &scm))
2365 } else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
2366 /* Copy credentials */
2367 scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
2368 unix_set_secdata(&scm, skb);
2372 /* Copy address just once */
2373 if (state->msg && state->msg->msg_name) {
2374 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr,
2375 state->msg->msg_name);
2376 unix_copy_addr(state->msg, skb->sk);
2380 chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size);
2382 chunk = state->recv_actor(skb, skip, chunk, state);
2383 drop_skb = !unix_skb_len(skb);
2384 /* skb is only safe to use if !drop_skb */
2395 /* the skb was touched by a concurrent reader;
2396 * we should not expect anything from this skb
2397 * anymore and assume it invalid - we can be
2398 * sure it was dropped from the socket queue
2400 * let's report a short read
2406 /* Mark read part of skb as used */
2407 if (!(flags & MSG_PEEK)) {
2408 UNIXCB(skb).consumed += chunk;
2410 sk_peek_offset_bwd(sk, chunk);
2413 unix_detach_fds(&scm, skb);
2415 if (unix_skb_len(skb))
2418 skb_unlink(skb, &sk->sk_receive_queue);
2424 /* It is questionable, see note in unix_dgram_recvmsg.
2427 scm.fp = scm_fp_dup(UNIXCB(skb).fp);
2429 sk_peek_offset_fwd(sk, chunk);
2436 last_len = skb->len;
2437 unix_state_lock(sk);
2438 skb = skb_peek_next(skb, &sk->sk_receive_queue);
2441 unix_state_unlock(sk);
2446 mutex_unlock(&u->readlock);
2448 scm_recv(sock, state->msg, &scm, flags);
2452 return copied ? : err;
2455 static int unix_stream_read_actor(struct sk_buff *skb,
2456 int skip, int chunk,
2457 struct unix_stream_read_state *state)
2461 ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip,
2463 return ret ?: chunk;
2466 static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
2467 size_t size, int flags)
2469 struct unix_stream_read_state state = {
2470 .recv_actor = unix_stream_read_actor,
2477 return unix_stream_read_generic(&state);
2480 static ssize_t skb_unix_socket_splice(struct sock *sk,
2481 struct pipe_inode_info *pipe,
2482 struct splice_pipe_desc *spd)
2485 struct unix_sock *u = unix_sk(sk);
2487 mutex_unlock(&u->readlock);
2488 ret = splice_to_pipe(pipe, spd);
2489 mutex_lock(&u->readlock);
2494 static int unix_stream_splice_actor(struct sk_buff *skb,
2495 int skip, int chunk,
2496 struct unix_stream_read_state *state)
2498 return skb_splice_bits(skb, state->socket->sk,
2499 UNIXCB(skb).consumed + skip,
2500 state->pipe, chunk, state->splice_flags,
2501 skb_unix_socket_splice);
2504 static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos,
2505 struct pipe_inode_info *pipe,
2506 size_t size, unsigned int flags)
2508 struct unix_stream_read_state state = {
2509 .recv_actor = unix_stream_splice_actor,
2513 .splice_flags = flags,
2516 if (unlikely(*ppos))
2519 if (sock->file->f_flags & O_NONBLOCK ||
2520 flags & SPLICE_F_NONBLOCK)
2521 state.flags = MSG_DONTWAIT;
2523 return unix_stream_read_generic(&state);
2526 static int unix_shutdown(struct socket *sock, int mode)
2528 struct sock *sk = sock->sk;
2531 if (mode < SHUT_RD || mode > SHUT_RDWR)
2534 * SHUT_RD (0) -> RCV_SHUTDOWN (1)
2535 * SHUT_WR (1) -> SEND_SHUTDOWN (2)
2536 * SHUT_RDWR (2) -> SHUTDOWN_MASK (3)
2540 unix_state_lock(sk);
2541 sk->sk_shutdown |= mode;
2542 other = unix_peer(sk);
2545 unix_state_unlock(sk);
2546 sk->sk_state_change(sk);
2549 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
2553 if (mode&RCV_SHUTDOWN)
2554 peer_mode |= SEND_SHUTDOWN;
2555 if (mode&SEND_SHUTDOWN)
2556 peer_mode |= RCV_SHUTDOWN;
2557 unix_state_lock(other);
2558 other->sk_shutdown |= peer_mode;
2559 unix_state_unlock(other);
2560 other->sk_state_change(other);
2561 if (peer_mode == SHUTDOWN_MASK)
2562 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
2563 else if (peer_mode & RCV_SHUTDOWN)
2564 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
2572 long unix_inq_len(struct sock *sk)
2574 struct sk_buff *skb;
2577 if (sk->sk_state == TCP_LISTEN)
2580 spin_lock(&sk->sk_receive_queue.lock);
2581 if (sk->sk_type == SOCK_STREAM ||
2582 sk->sk_type == SOCK_SEQPACKET) {
2583 skb_queue_walk(&sk->sk_receive_queue, skb)
2584 amount += unix_skb_len(skb);
2586 skb = skb_peek(&sk->sk_receive_queue);
2590 spin_unlock(&sk->sk_receive_queue.lock);
2594 EXPORT_SYMBOL_GPL(unix_inq_len);
2596 long unix_outq_len(struct sock *sk)
2598 return sk_wmem_alloc_get(sk);
2600 EXPORT_SYMBOL_GPL(unix_outq_len);
2602 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2604 struct sock *sk = sock->sk;
2610 amount = unix_outq_len(sk);
2611 err = put_user(amount, (int __user *)arg);
2614 amount = unix_inq_len(sk);
2618 err = put_user(amount, (int __user *)arg);
2627 static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait)
2629 struct sock *sk = sock->sk;
2632 sock_poll_wait(file, sk_sleep(sk), wait);
2635 /* exceptional events? */
2638 if (sk->sk_shutdown == SHUTDOWN_MASK)
2640 if (sk->sk_shutdown & RCV_SHUTDOWN)
2641 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2644 if (!skb_queue_empty(&sk->sk_receive_queue))
2645 mask |= POLLIN | POLLRDNORM;
2647 /* Connection-based need to check for termination and startup */
2648 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2649 sk->sk_state == TCP_CLOSE)
2653 * we set writable also when the other side has shut down the
2654 * connection. This prevents stuck sockets.
2656 if (unix_writable(sk))
2657 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2662 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2665 struct sock *sk = sock->sk, *other;
2666 unsigned int mask, writable;
2668 sock_poll_wait(file, sk_sleep(sk), wait);
2671 /* exceptional events? */
2672 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2674 (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
2676 if (sk->sk_shutdown & RCV_SHUTDOWN)
2677 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2678 if (sk->sk_shutdown == SHUTDOWN_MASK)
2682 if (!skb_queue_empty(&sk->sk_receive_queue))
2683 mask |= POLLIN | POLLRDNORM;
2685 /* Connection-based need to check for termination and startup */
2686 if (sk->sk_type == SOCK_SEQPACKET) {
2687 if (sk->sk_state == TCP_CLOSE)
2689 /* connection hasn't started yet? */
2690 if (sk->sk_state == TCP_SYN_SENT)
2694 /* No write status requested, avoid expensive OUT tests. */
2695 if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT)))
2698 writable = unix_writable(sk);
2700 unix_state_lock(sk);
2702 other = unix_peer(sk);
2703 if (other && unix_peer(other) != sk &&
2704 unix_recvq_full(other) &&
2705 unix_dgram_peer_wake_me(sk, other))
2708 unix_state_unlock(sk);
2712 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2714 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2719 #ifdef CONFIG_PROC_FS
2721 #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
2723 #define get_bucket(x) ((x) >> BUCKET_SPACE)
2724 #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1))
2725 #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
2727 static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
2729 unsigned long offset = get_offset(*pos);
2730 unsigned long bucket = get_bucket(*pos);
2732 unsigned long count = 0;
2734 for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) {
2735 if (sock_net(sk) != seq_file_net(seq))
2737 if (++count == offset)
2744 static struct sock *unix_next_socket(struct seq_file *seq,
2748 unsigned long bucket;
2750 while (sk > (struct sock *)SEQ_START_TOKEN) {
2754 if (sock_net(sk) == seq_file_net(seq))
2759 sk = unix_from_bucket(seq, pos);
2764 bucket = get_bucket(*pos) + 1;
2765 *pos = set_bucket_offset(bucket, 1);
2766 } while (bucket < ARRAY_SIZE(unix_socket_table));
2771 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2772 __acquires(unix_table_lock)
2774 spin_lock(&unix_table_lock);
2777 return SEQ_START_TOKEN;
2779 if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table))
2782 return unix_next_socket(seq, NULL, pos);
2785 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2788 return unix_next_socket(seq, v, pos);
2791 static void unix_seq_stop(struct seq_file *seq, void *v)
2792 __releases(unix_table_lock)
2794 spin_unlock(&unix_table_lock);
2797 static int unix_seq_show(struct seq_file *seq, void *v)
2800 if (v == SEQ_START_TOKEN)
2801 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2805 struct unix_sock *u = unix_sk(s);
2808 seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu",
2810 atomic_read(&s->sk_refcnt),
2812 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2815 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2816 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2824 len = u->addr->len - sizeof(short);
2825 if (!UNIX_ABSTRACT(s))
2831 for ( ; i < len; i++)
2832 seq_putc(seq, u->addr->name->sun_path[i]);
2834 unix_state_unlock(s);
2835 seq_putc(seq, '\n');
2841 static const struct seq_operations unix_seq_ops = {
2842 .start = unix_seq_start,
2843 .next = unix_seq_next,
2844 .stop = unix_seq_stop,
2845 .show = unix_seq_show,
2848 static int unix_seq_open(struct inode *inode, struct file *file)
2850 return seq_open_net(inode, file, &unix_seq_ops,
2851 sizeof(struct seq_net_private));
2854 static const struct file_operations unix_seq_fops = {
2855 .owner = THIS_MODULE,
2856 .open = unix_seq_open,
2858 .llseek = seq_lseek,
2859 .release = seq_release_net,
2864 static const struct net_proto_family unix_family_ops = {
2866 .create = unix_create,
2867 .owner = THIS_MODULE,
2871 static int __net_init unix_net_init(struct net *net)
2873 int error = -ENOMEM;
2875 net->unx.sysctl_max_dgram_qlen = 10;
2876 if (unix_sysctl_register(net))
2879 #ifdef CONFIG_PROC_FS
2880 if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) {
2881 unix_sysctl_unregister(net);
2890 static void __net_exit unix_net_exit(struct net *net)
2892 unix_sysctl_unregister(net);
2893 remove_proc_entry("unix", net->proc_net);
2896 static struct pernet_operations unix_net_ops = {
2897 .init = unix_net_init,
2898 .exit = unix_net_exit,
2901 static int __init af_unix_init(void)
2905 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
2907 rc = proto_register(&unix_proto, 1);
2909 pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
2913 sock_register(&unix_family_ops);
2914 register_pernet_subsys(&unix_net_ops);
2919 static void __exit af_unix_exit(void)
2921 sock_unregister(PF_UNIX);
2922 proto_unregister(&unix_proto);
2923 unregister_pernet_subsys(&unix_net_ops);
2926 /* Earlier than device_initcall() so that other drivers invoking
2927 request_module() don't end up in a loop when modprobe tries
2928 to use a UNIX socket. But later than subsys_initcall() because
2929 we depend on stuff initialised there */
2930 fs_initcall(af_unix_init);
2931 module_exit(af_unix_exit);
2933 MODULE_LICENSE("GPL");
2934 MODULE_ALIAS_NETPROTO(PF_UNIX);