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 #include <linux/module.h>
84 #include <linux/kernel.h>
85 #include <linux/signal.h>
86 #include <linux/sched.h>
87 #include <linux/errno.h>
88 #include <linux/string.h>
89 #include <linux/stat.h>
90 #include <linux/dcache.h>
91 #include <linux/namei.h>
92 #include <linux/socket.h>
94 #include <linux/fcntl.h>
95 #include <linux/termios.h>
96 #include <linux/sockios.h>
97 #include <linux/net.h>
100 #include <linux/slab.h>
101 #include <asm/uaccess.h>
102 #include <linux/skbuff.h>
103 #include <linux/netdevice.h>
104 #include <net/net_namespace.h>
105 #include <net/sock.h>
106 #include <net/tcp_states.h>
107 #include <net/af_unix.h>
108 #include <linux/proc_fs.h>
109 #include <linux/seq_file.h>
111 #include <linux/init.h>
112 #include <linux/poll.h>
113 #include <linux/rtnetlink.h>
114 #include <linux/mount.h>
115 #include <net/checksum.h>
116 #include <linux/security.h>
118 static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
119 static DEFINE_SPINLOCK(unix_table_lock);
120 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
122 #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
124 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
126 #ifdef CONFIG_SECURITY_NETWORK
127 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
132 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
134 scm->secid = *UNIXSID(skb);
137 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
140 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
142 #endif /* CONFIG_SECURITY_NETWORK */
145 * SMP locking strategy:
146 * hash table is protected with spinlock unix_table_lock
147 * each socket state is protected by separate rwlock.
150 static inline unsigned unix_hash_fold(__wsum n)
152 unsigned hash = (__force unsigned)n;
155 return hash&(UNIX_HASH_SIZE-1);
158 #define unix_peer(sk) (unix_sk(sk)->peer)
160 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
162 return unix_peer(osk) == sk;
165 static inline int unix_may_send(struct sock *sk, struct sock *osk)
167 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
170 static inline int unix_recvq_full(struct sock const *sk)
172 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
175 static struct sock *unix_peer_get(struct sock *s)
183 unix_state_unlock(s);
187 static inline void unix_release_addr(struct unix_address *addr)
189 if (atomic_dec_and_test(&addr->refcnt))
194 * Check unix socket name:
195 * - should be not zero length.
196 * - if started by not zero, should be NULL terminated (FS object)
197 * - if started by zero, it is abstract name.
200 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
202 if (len <= sizeof(short) || len > sizeof(*sunaddr))
204 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
206 if (sunaddr->sun_path[0]) {
208 * This may look like an off by one error but it is a bit more
209 * subtle. 108 is the longest valid AF_UNIX path for a binding.
210 * sun_path[108] doesnt as such exist. However in kernel space
211 * we are guaranteed that it is a valid memory location in our
212 * kernel address buffer.
214 ((char *)sunaddr)[len]=0;
215 len = strlen(sunaddr->sun_path)+1+sizeof(short);
219 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
223 static void __unix_remove_socket(struct sock *sk)
225 sk_del_node_init(sk);
228 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
230 WARN_ON(!sk_unhashed(sk));
231 sk_add_node(sk, list);
234 static inline void unix_remove_socket(struct sock *sk)
236 spin_lock(&unix_table_lock);
237 __unix_remove_socket(sk);
238 spin_unlock(&unix_table_lock);
241 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
243 spin_lock(&unix_table_lock);
244 __unix_insert_socket(list, sk);
245 spin_unlock(&unix_table_lock);
248 static struct sock *__unix_find_socket_byname(struct net *net,
249 struct sockaddr_un *sunname,
250 int len, int type, unsigned hash)
253 struct hlist_node *node;
255 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
256 struct unix_sock *u = unix_sk(s);
258 if (!net_eq(sock_net(s), net))
261 if (u->addr->len == len &&
262 !memcmp(u->addr->name, sunname, len))
270 static inline struct sock *unix_find_socket_byname(struct net *net,
271 struct sockaddr_un *sunname,
277 spin_lock(&unix_table_lock);
278 s = __unix_find_socket_byname(net, sunname, len, type, hash);
281 spin_unlock(&unix_table_lock);
285 static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
288 struct hlist_node *node;
290 spin_lock(&unix_table_lock);
292 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
293 struct dentry *dentry = unix_sk(s)->dentry;
295 if (!net_eq(sock_net(s), net))
298 if(dentry && dentry->d_inode == i)
306 spin_unlock(&unix_table_lock);
310 static inline int unix_writable(struct sock *sk)
312 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
315 static void unix_write_space(struct sock *sk)
317 read_lock(&sk->sk_callback_lock);
318 if (unix_writable(sk)) {
319 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
320 wake_up_interruptible_sync(sk->sk_sleep);
321 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
323 read_unlock(&sk->sk_callback_lock);
326 /* When dgram socket disconnects (or changes its peer), we clear its receive
327 * queue of packets arrived from previous peer. First, it allows to do
328 * flow control based only on wmem_alloc; second, sk connected to peer
329 * may receive messages only from that peer. */
330 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
332 if (!skb_queue_empty(&sk->sk_receive_queue)) {
333 skb_queue_purge(&sk->sk_receive_queue);
334 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
336 /* If one link of bidirectional dgram pipe is disconnected,
337 * we signal error. Messages are lost. Do not make this,
338 * when peer was not connected to us.
340 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
341 other->sk_err = ECONNRESET;
342 other->sk_error_report(other);
347 static void unix_sock_destructor(struct sock *sk)
349 struct unix_sock *u = unix_sk(sk);
351 skb_queue_purge(&sk->sk_receive_queue);
353 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
354 WARN_ON(!sk_unhashed(sk));
355 WARN_ON(sk->sk_socket);
356 if (!sock_flag(sk, SOCK_DEAD)) {
357 printk("Attempt to release alive unix socket: %p\n", sk);
362 unix_release_addr(u->addr);
364 atomic_dec(&unix_nr_socks);
365 #ifdef UNIX_REFCNT_DEBUG
366 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
370 static int unix_release_sock (struct sock *sk, int embrion)
372 struct unix_sock *u = unix_sk(sk);
373 struct dentry *dentry;
374 struct vfsmount *mnt;
379 unix_remove_socket(sk);
384 sk->sk_shutdown = SHUTDOWN_MASK;
389 state = sk->sk_state;
390 sk->sk_state = TCP_CLOSE;
391 unix_state_unlock(sk);
393 wake_up_interruptible_all(&u->peer_wait);
395 skpair=unix_peer(sk);
398 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
399 unix_state_lock(skpair);
401 skpair->sk_shutdown = SHUTDOWN_MASK;
402 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
403 skpair->sk_err = ECONNRESET;
404 unix_state_unlock(skpair);
405 skpair->sk_state_change(skpair);
406 read_lock(&skpair->sk_callback_lock);
407 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
408 read_unlock(&skpair->sk_callback_lock);
410 sock_put(skpair); /* It may now die */
411 unix_peer(sk) = NULL;
414 /* Try to flush out this socket. Throw out buffers at least */
416 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
417 if (state==TCP_LISTEN)
418 unix_release_sock(skb->sk, 1);
419 /* passed fds are erased in the kfree_skb hook */
430 /* ---- Socket is dead now and most probably destroyed ---- */
433 * Fixme: BSD difference: In BSD all sockets connected to use get
434 * ECONNRESET and we die on the spot. In Linux we behave
435 * like files and pipes do and wait for the last
438 * Can't we simply set sock->err?
440 * What the above comment does talk about? --ANK(980817)
443 if (unix_tot_inflight)
444 unix_gc(); /* Garbage collect fds */
449 static int unix_listen(struct socket *sock, int backlog)
452 struct sock *sk = sock->sk;
453 struct unix_sock *u = unix_sk(sk);
456 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
457 goto out; /* Only stream/seqpacket sockets accept */
460 goto out; /* No listens on an unbound socket */
462 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
464 if (backlog > sk->sk_max_ack_backlog)
465 wake_up_interruptible_all(&u->peer_wait);
466 sk->sk_max_ack_backlog = backlog;
467 sk->sk_state = TCP_LISTEN;
468 /* set credentials so connect can copy them */
469 sk->sk_peercred.pid = task_tgid_vnr(current);
470 sk->sk_peercred.uid = current->euid;
471 sk->sk_peercred.gid = current->egid;
475 unix_state_unlock(sk);
480 static int unix_release(struct socket *);
481 static int unix_bind(struct socket *, struct sockaddr *, int);
482 static int unix_stream_connect(struct socket *, struct sockaddr *,
483 int addr_len, int flags);
484 static int unix_socketpair(struct socket *, struct socket *);
485 static int unix_accept(struct socket *, struct socket *, int);
486 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
487 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
488 static unsigned int unix_dgram_poll(struct file *, struct socket *,
490 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
491 static int unix_shutdown(struct socket *, int);
492 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
493 struct msghdr *, size_t);
494 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
495 struct msghdr *, size_t, int);
496 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
497 struct msghdr *, size_t);
498 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
499 struct msghdr *, size_t, int);
500 static int unix_dgram_connect(struct socket *, struct sockaddr *,
502 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
503 struct msghdr *, size_t);
505 static const struct proto_ops unix_stream_ops = {
507 .owner = THIS_MODULE,
508 .release = unix_release,
510 .connect = unix_stream_connect,
511 .socketpair = unix_socketpair,
512 .accept = unix_accept,
513 .getname = unix_getname,
516 .listen = unix_listen,
517 .shutdown = unix_shutdown,
518 .setsockopt = sock_no_setsockopt,
519 .getsockopt = sock_no_getsockopt,
520 .sendmsg = unix_stream_sendmsg,
521 .recvmsg = unix_stream_recvmsg,
522 .mmap = sock_no_mmap,
523 .sendpage = sock_no_sendpage,
526 static const struct proto_ops unix_dgram_ops = {
528 .owner = THIS_MODULE,
529 .release = unix_release,
531 .connect = unix_dgram_connect,
532 .socketpair = unix_socketpair,
533 .accept = sock_no_accept,
534 .getname = unix_getname,
535 .poll = unix_dgram_poll,
537 .listen = sock_no_listen,
538 .shutdown = unix_shutdown,
539 .setsockopt = sock_no_setsockopt,
540 .getsockopt = sock_no_getsockopt,
541 .sendmsg = unix_dgram_sendmsg,
542 .recvmsg = unix_dgram_recvmsg,
543 .mmap = sock_no_mmap,
544 .sendpage = sock_no_sendpage,
547 static const struct proto_ops unix_seqpacket_ops = {
549 .owner = THIS_MODULE,
550 .release = unix_release,
552 .connect = unix_stream_connect,
553 .socketpair = unix_socketpair,
554 .accept = unix_accept,
555 .getname = unix_getname,
556 .poll = unix_dgram_poll,
558 .listen = unix_listen,
559 .shutdown = unix_shutdown,
560 .setsockopt = sock_no_setsockopt,
561 .getsockopt = sock_no_getsockopt,
562 .sendmsg = unix_seqpacket_sendmsg,
563 .recvmsg = unix_dgram_recvmsg,
564 .mmap = sock_no_mmap,
565 .sendpage = sock_no_sendpage,
568 static struct proto unix_proto = {
570 .owner = THIS_MODULE,
571 .obj_size = sizeof(struct unix_sock),
575 * AF_UNIX sockets do not interact with hardware, hence they
576 * dont trigger interrupts - so it's safe for them to have
577 * bh-unsafe locking for their sk_receive_queue.lock. Split off
578 * this special lock-class by reinitializing the spinlock key:
580 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
582 static struct sock * unix_create1(struct net *net, struct socket *sock)
584 struct sock *sk = NULL;
587 atomic_inc(&unix_nr_socks);
588 if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
591 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
595 sock_init_data(sock,sk);
596 lockdep_set_class(&sk->sk_receive_queue.lock,
597 &af_unix_sk_receive_queue_lock_key);
599 sk->sk_write_space = unix_write_space;
600 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
601 sk->sk_destruct = unix_sock_destructor;
605 spin_lock_init(&u->lock);
606 atomic_long_set(&u->inflight, 0);
607 INIT_LIST_HEAD(&u->link);
608 mutex_init(&u->readlock); /* single task reading lock */
609 init_waitqueue_head(&u->peer_wait);
610 unix_insert_socket(unix_sockets_unbound, sk);
613 atomic_dec(&unix_nr_socks);
617 static int unix_create(struct net *net, struct socket *sock, int protocol)
619 if (protocol && protocol != PF_UNIX)
620 return -EPROTONOSUPPORT;
622 sock->state = SS_UNCONNECTED;
624 switch (sock->type) {
626 sock->ops = &unix_stream_ops;
629 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
633 sock->type=SOCK_DGRAM;
635 sock->ops = &unix_dgram_ops;
638 sock->ops = &unix_seqpacket_ops;
641 return -ESOCKTNOSUPPORT;
644 return unix_create1(net, sock) ? 0 : -ENOMEM;
647 static int unix_release(struct socket *sock)
649 struct sock *sk = sock->sk;
656 return unix_release_sock (sk, 0);
659 static int unix_autobind(struct socket *sock)
661 struct sock *sk = sock->sk;
662 struct net *net = sock_net(sk);
663 struct unix_sock *u = unix_sk(sk);
664 static u32 ordernum = 1;
665 struct unix_address * addr;
668 mutex_lock(&u->readlock);
675 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
679 addr->name->sun_family = AF_UNIX;
680 atomic_set(&addr->refcnt, 1);
683 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
684 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
686 spin_lock(&unix_table_lock);
687 ordernum = (ordernum+1)&0xFFFFF;
689 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
691 spin_unlock(&unix_table_lock);
692 /* Sanity yield. It is unusual case, but yet... */
693 if (!(ordernum&0xFF))
697 addr->hash ^= sk->sk_type;
699 __unix_remove_socket(sk);
701 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
702 spin_unlock(&unix_table_lock);
705 out: mutex_unlock(&u->readlock);
709 static struct sock *unix_find_other(struct net *net,
710 struct sockaddr_un *sunname, int len,
711 int type, unsigned hash, int *error)
717 if (sunname->sun_path[0]) {
719 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
722 inode = path.dentry->d_inode;
723 err = inode_permission(inode, MAY_WRITE);
728 if (!S_ISSOCK(inode->i_mode))
730 u = unix_find_socket_byinode(net, inode);
734 if (u->sk_type == type)
735 touch_atime(path.mnt, path.dentry);
740 if (u->sk_type != type) {
746 u=unix_find_socket_byname(net, sunname, len, type, hash);
748 struct dentry *dentry;
749 dentry = unix_sk(u)->dentry;
751 touch_atime(unix_sk(u)->mnt, dentry);
765 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
767 struct sock *sk = sock->sk;
768 struct net *net = sock_net(sk);
769 struct unix_sock *u = unix_sk(sk);
770 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
771 struct dentry * dentry = NULL;
775 struct unix_address *addr;
776 struct hlist_head *list;
779 if (sunaddr->sun_family != AF_UNIX)
782 if (addr_len==sizeof(short)) {
783 err = unix_autobind(sock);
787 err = unix_mkname(sunaddr, addr_len, &hash);
792 mutex_lock(&u->readlock);
799 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
803 memcpy(addr->name, sunaddr, addr_len);
804 addr->len = addr_len;
805 addr->hash = hash ^ sk->sk_type;
806 atomic_set(&addr->refcnt, 1);
808 if (sunaddr->sun_path[0]) {
812 * Get the parent directory, calculate the hash for last
815 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
817 goto out_mknod_parent;
819 dentry = lookup_create(&nd, 0);
820 err = PTR_ERR(dentry);
822 goto out_mknod_unlock;
825 * All right, let's create it.
828 (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
829 err = mnt_want_write(nd.path.mnt);
832 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
833 mnt_drop_write(nd.path.mnt);
836 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
837 dput(nd.path.dentry);
838 nd.path.dentry = dentry;
840 addr->hash = UNIX_HASH_SIZE;
843 spin_lock(&unix_table_lock);
845 if (!sunaddr->sun_path[0]) {
847 if (__unix_find_socket_byname(net, sunaddr, addr_len,
848 sk->sk_type, hash)) {
849 unix_release_addr(addr);
853 list = &unix_socket_table[addr->hash];
855 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
856 u->dentry = nd.path.dentry;
857 u->mnt = nd.path.mnt;
861 __unix_remove_socket(sk);
863 __unix_insert_socket(list, sk);
866 spin_unlock(&unix_table_lock);
868 mutex_unlock(&u->readlock);
875 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
880 unix_release_addr(addr);
884 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
886 if (unlikely(sk1 == sk2) || !sk2) {
887 unix_state_lock(sk1);
891 unix_state_lock(sk1);
892 unix_state_lock_nested(sk2);
894 unix_state_lock(sk2);
895 unix_state_lock_nested(sk1);
899 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
901 if (unlikely(sk1 == sk2) || !sk2) {
902 unix_state_unlock(sk1);
905 unix_state_unlock(sk1);
906 unix_state_unlock(sk2);
909 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
912 struct sock *sk = sock->sk;
913 struct net *net = sock_net(sk);
914 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
919 if (addr->sa_family != AF_UNSPEC) {
920 err = unix_mkname(sunaddr, alen, &hash);
925 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
926 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
930 other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
934 unix_state_double_lock(sk, other);
936 /* Apparently VFS overslept socket death. Retry. */
937 if (sock_flag(other, SOCK_DEAD)) {
938 unix_state_double_unlock(sk, other);
944 if (!unix_may_send(sk, other))
947 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
953 * 1003.1g breaking connected state with AF_UNSPEC
956 unix_state_double_lock(sk, other);
960 * If it was connected, reconnect.
963 struct sock *old_peer = unix_peer(sk);
965 unix_state_double_unlock(sk, other);
967 if (other != old_peer)
968 unix_dgram_disconnected(sk, old_peer);
972 unix_state_double_unlock(sk, other);
977 unix_state_double_unlock(sk, other);
983 static long unix_wait_for_peer(struct sock *other, long timeo)
985 struct unix_sock *u = unix_sk(other);
989 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
991 sched = !sock_flag(other, SOCK_DEAD) &&
992 !(other->sk_shutdown & RCV_SHUTDOWN) &&
993 unix_recvq_full(other);
995 unix_state_unlock(other);
998 timeo = schedule_timeout(timeo);
1000 finish_wait(&u->peer_wait, &wait);
1004 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1005 int addr_len, int flags)
1007 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1008 struct sock *sk = sock->sk;
1009 struct net *net = sock_net(sk);
1010 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1011 struct sock *newsk = NULL;
1012 struct sock *other = NULL;
1013 struct sk_buff *skb = NULL;
1019 err = unix_mkname(sunaddr, addr_len, &hash);
1024 if (test_bit(SOCK_PASSCRED, &sock->flags)
1025 && !u->addr && (err = unix_autobind(sock)) != 0)
1028 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1030 /* First of all allocate resources.
1031 If we will make it after state is locked,
1032 we will have to recheck all again in any case.
1037 /* create new sock for complete connection */
1038 newsk = unix_create1(sock_net(sk), NULL);
1042 /* Allocate skb for sending to listening sock */
1043 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1048 /* Find listening sock. */
1049 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1053 /* Latch state of peer */
1054 unix_state_lock(other);
1056 /* Apparently VFS overslept socket death. Retry. */
1057 if (sock_flag(other, SOCK_DEAD)) {
1058 unix_state_unlock(other);
1063 err = -ECONNREFUSED;
1064 if (other->sk_state != TCP_LISTEN)
1067 if (unix_recvq_full(other)) {
1072 timeo = unix_wait_for_peer(other, timeo);
1074 err = sock_intr_errno(timeo);
1075 if (signal_pending(current))
1083 It is tricky place. We need to grab write lock and cannot
1084 drop lock on peer. It is dangerous because deadlock is
1085 possible. Connect to self case and simultaneous
1086 attempt to connect are eliminated by checking socket
1087 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1088 check this before attempt to grab lock.
1090 Well, and we have to recheck the state after socket locked.
1096 /* This is ok... continue with connect */
1098 case TCP_ESTABLISHED:
1099 /* Socket is already connected */
1107 unix_state_lock_nested(sk);
1109 if (sk->sk_state != st) {
1110 unix_state_unlock(sk);
1111 unix_state_unlock(other);
1116 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1118 unix_state_unlock(sk);
1122 /* The way is open! Fastly set all the necessary fields... */
1125 unix_peer(newsk) = sk;
1126 newsk->sk_state = TCP_ESTABLISHED;
1127 newsk->sk_type = sk->sk_type;
1128 newsk->sk_peercred.pid = task_tgid_vnr(current);
1129 newsk->sk_peercred.uid = current->euid;
1130 newsk->sk_peercred.gid = current->egid;
1131 newu = unix_sk(newsk);
1132 newsk->sk_sleep = &newu->peer_wait;
1133 otheru = unix_sk(other);
1135 /* copy address information from listening to new sock*/
1137 atomic_inc(&otheru->addr->refcnt);
1138 newu->addr = otheru->addr;
1140 if (otheru->dentry) {
1141 newu->dentry = dget(otheru->dentry);
1142 newu->mnt = mntget(otheru->mnt);
1145 /* Set credentials */
1146 sk->sk_peercred = other->sk_peercred;
1148 sock->state = SS_CONNECTED;
1149 sk->sk_state = TCP_ESTABLISHED;
1152 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1153 unix_peer(sk) = newsk;
1155 unix_state_unlock(sk);
1157 /* take ten and and send info to listening sock */
1158 spin_lock(&other->sk_receive_queue.lock);
1159 __skb_queue_tail(&other->sk_receive_queue, skb);
1160 spin_unlock(&other->sk_receive_queue.lock);
1161 unix_state_unlock(other);
1162 other->sk_data_ready(other, 0);
1168 unix_state_unlock(other);
1174 unix_release_sock(newsk, 0);
1180 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1182 struct sock *ska=socka->sk, *skb = sockb->sk;
1184 /* Join our sockets back to back */
1189 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
1190 ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid;
1191 ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid;
1193 if (ska->sk_type != SOCK_DGRAM) {
1194 ska->sk_state = TCP_ESTABLISHED;
1195 skb->sk_state = TCP_ESTABLISHED;
1196 socka->state = SS_CONNECTED;
1197 sockb->state = SS_CONNECTED;
1202 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1204 struct sock *sk = sock->sk;
1206 struct sk_buff *skb;
1210 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1214 if (sk->sk_state != TCP_LISTEN)
1217 /* If socket state is TCP_LISTEN it cannot change (for now...),
1218 * so that no locks are necessary.
1221 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1223 /* This means receive shutdown. */
1230 skb_free_datagram(sk, skb);
1231 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1233 /* attach accepted sock to socket */
1234 unix_state_lock(tsk);
1235 newsock->state = SS_CONNECTED;
1236 sock_graft(tsk, newsock);
1237 unix_state_unlock(tsk);
1245 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1247 struct sock *sk = sock->sk;
1248 struct unix_sock *u;
1249 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1253 sk = unix_peer_get(sk);
1264 unix_state_lock(sk);
1266 sunaddr->sun_family = AF_UNIX;
1267 sunaddr->sun_path[0] = 0;
1268 *uaddr_len = sizeof(short);
1270 struct unix_address *addr = u->addr;
1272 *uaddr_len = addr->len;
1273 memcpy(sunaddr, addr->name, *uaddr_len);
1275 unix_state_unlock(sk);
1281 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1285 scm->fp = UNIXCB(skb).fp;
1286 skb->destructor = sock_wfree;
1287 UNIXCB(skb).fp = NULL;
1289 for (i=scm->fp->count-1; i>=0; i--)
1290 unix_notinflight(scm->fp->fp[i]);
1293 static void unix_destruct_fds(struct sk_buff *skb)
1295 struct scm_cookie scm;
1296 memset(&scm, 0, sizeof(scm));
1297 unix_detach_fds(&scm, skb);
1299 /* Alas, it calls VFS */
1300 /* So fscking what? fput() had been SMP-safe since the last Summer */
1305 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1308 for (i=scm->fp->count-1; i>=0; i--)
1309 unix_inflight(scm->fp->fp[i]);
1310 UNIXCB(skb).fp = scm->fp;
1311 skb->destructor = unix_destruct_fds;
1316 * Send AF_UNIX data.
1319 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1320 struct msghdr *msg, size_t len)
1322 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1323 struct sock *sk = sock->sk;
1324 struct net *net = sock_net(sk);
1325 struct unix_sock *u = unix_sk(sk);
1326 struct sockaddr_un *sunaddr=msg->msg_name;
1327 struct sock *other = NULL;
1328 int namelen = 0; /* fake GCC */
1331 struct sk_buff *skb;
1333 struct scm_cookie tmp_scm;
1335 if (NULL == siocb->scm)
1336 siocb->scm = &tmp_scm;
1337 err = scm_send(sock, msg, siocb->scm);
1342 if (msg->msg_flags&MSG_OOB)
1345 if (msg->msg_namelen) {
1346 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1353 other = unix_peer_get(sk);
1358 if (test_bit(SOCK_PASSCRED, &sock->flags)
1359 && !u->addr && (err = unix_autobind(sock)) != 0)
1363 if (len > sk->sk_sndbuf - 32)
1366 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1370 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1372 unix_attach_fds(siocb->scm, skb);
1373 unix_get_secdata(siocb->scm, skb);
1375 skb_reset_transport_header(skb);
1376 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1380 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1385 if (sunaddr == NULL)
1388 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1394 unix_state_lock(other);
1396 if (!unix_may_send(sk, other))
1399 if (sock_flag(other, SOCK_DEAD)) {
1401 * Check with 1003.1g - what should
1404 unix_state_unlock(other);
1408 unix_state_lock(sk);
1409 if (unix_peer(sk) == other) {
1411 unix_state_unlock(sk);
1413 unix_dgram_disconnected(sk, other);
1415 err = -ECONNREFUSED;
1417 unix_state_unlock(sk);
1427 if (other->sk_shutdown & RCV_SHUTDOWN)
1430 if (sk->sk_type != SOCK_SEQPACKET) {
1431 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1436 if (unix_peer(other) != sk && unix_recvq_full(other)) {
1442 timeo = unix_wait_for_peer(other, timeo);
1444 err = sock_intr_errno(timeo);
1445 if (signal_pending(current))
1451 skb_queue_tail(&other->sk_receive_queue, skb);
1452 unix_state_unlock(other);
1453 other->sk_data_ready(other, len);
1455 scm_destroy(siocb->scm);
1459 unix_state_unlock(other);
1465 scm_destroy(siocb->scm);
1470 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1471 struct msghdr *msg, size_t len)
1473 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1474 struct sock *sk = sock->sk;
1475 struct sock *other = NULL;
1476 struct sockaddr_un *sunaddr=msg->msg_name;
1478 struct sk_buff *skb;
1480 struct scm_cookie tmp_scm;
1482 if (NULL == siocb->scm)
1483 siocb->scm = &tmp_scm;
1484 err = scm_send(sock, msg, siocb->scm);
1489 if (msg->msg_flags&MSG_OOB)
1492 if (msg->msg_namelen) {
1493 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1498 other = unix_peer(sk);
1503 if (sk->sk_shutdown & SEND_SHUTDOWN)
1509 * Optimisation for the fact that under 0.01% of X
1510 * messages typically need breaking up.
1515 /* Keep two messages in the pipe so it schedules better */
1516 if (size > ((sk->sk_sndbuf >> 1) - 64))
1517 size = (sk->sk_sndbuf >> 1) - 64;
1519 if (size > SKB_MAX_ALLOC)
1520 size = SKB_MAX_ALLOC;
1526 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1532 * If you pass two values to the sock_alloc_send_skb
1533 * it tries to grab the large buffer with GFP_NOFS
1534 * (which can fail easily), and if it fails grab the
1535 * fallback size buffer which is under a page and will
1538 size = min_t(int, size, skb_tailroom(skb));
1540 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1542 unix_attach_fds(siocb->scm, skb);
1544 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1549 unix_state_lock(other);
1551 if (sock_flag(other, SOCK_DEAD) ||
1552 (other->sk_shutdown & RCV_SHUTDOWN))
1555 skb_queue_tail(&other->sk_receive_queue, skb);
1556 unix_state_unlock(other);
1557 other->sk_data_ready(other, size);
1561 scm_destroy(siocb->scm);
1567 unix_state_unlock(other);
1570 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1571 send_sig(SIGPIPE,current,0);
1574 scm_destroy(siocb->scm);
1576 return sent ? : err;
1579 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1580 struct msghdr *msg, size_t len)
1583 struct sock *sk = sock->sk;
1585 err = sock_error(sk);
1589 if (sk->sk_state != TCP_ESTABLISHED)
1592 if (msg->msg_namelen)
1593 msg->msg_namelen = 0;
1595 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1598 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1600 struct unix_sock *u = unix_sk(sk);
1602 msg->msg_namelen = 0;
1604 msg->msg_namelen = u->addr->len;
1605 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1609 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1610 struct msghdr *msg, size_t size,
1613 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1614 struct scm_cookie tmp_scm;
1615 struct sock *sk = sock->sk;
1616 struct unix_sock *u = unix_sk(sk);
1617 int noblock = flags & MSG_DONTWAIT;
1618 struct sk_buff *skb;
1625 msg->msg_namelen = 0;
1627 mutex_lock(&u->readlock);
1629 skb = skb_recv_datagram(sk, flags, noblock, &err);
1631 unix_state_lock(sk);
1632 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1633 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1634 (sk->sk_shutdown & RCV_SHUTDOWN))
1636 unix_state_unlock(sk);
1640 wake_up_interruptible_sync(&u->peer_wait);
1643 unix_copy_addr(msg, skb->sk);
1645 if (size > skb->len)
1647 else if (size < skb->len)
1648 msg->msg_flags |= MSG_TRUNC;
1650 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1655 siocb->scm = &tmp_scm;
1656 memset(&tmp_scm, 0, sizeof(tmp_scm));
1658 siocb->scm->creds = *UNIXCREDS(skb);
1659 unix_set_secdata(siocb->scm, skb);
1661 if (!(flags & MSG_PEEK))
1664 unix_detach_fds(siocb->scm, skb);
1668 /* It is questionable: on PEEK we could:
1669 - do not return fds - good, but too simple 8)
1670 - return fds, and do not return them on read (old strategy,
1672 - clone fds (I chose it for now, it is the most universal
1675 POSIX 1003.1g does not actually define this clearly
1676 at all. POSIX 1003.1g doesn't define a lot of things
1681 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1685 scm_recv(sock, msg, siocb->scm, flags);
1688 skb_free_datagram(sk,skb);
1690 mutex_unlock(&u->readlock);
1696 * Sleep until data has arrive. But check for races..
1699 static long unix_stream_data_wait(struct sock * sk, long timeo)
1703 unix_state_lock(sk);
1706 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1708 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1710 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1711 signal_pending(current) ||
1715 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1716 unix_state_unlock(sk);
1717 timeo = schedule_timeout(timeo);
1718 unix_state_lock(sk);
1719 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1722 finish_wait(sk->sk_sleep, &wait);
1723 unix_state_unlock(sk);
1729 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1730 struct msghdr *msg, size_t size,
1733 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1734 struct scm_cookie tmp_scm;
1735 struct sock *sk = sock->sk;
1736 struct unix_sock *u = unix_sk(sk);
1737 struct sockaddr_un *sunaddr=msg->msg_name;
1739 int check_creds = 0;
1745 if (sk->sk_state != TCP_ESTABLISHED)
1752 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1753 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1755 msg->msg_namelen = 0;
1757 /* Lock the socket to prevent queue disordering
1758 * while sleeps in memcpy_tomsg
1762 siocb->scm = &tmp_scm;
1763 memset(&tmp_scm, 0, sizeof(tmp_scm));
1766 mutex_lock(&u->readlock);
1771 struct sk_buff *skb;
1773 unix_state_lock(sk);
1774 skb = skb_dequeue(&sk->sk_receive_queue);
1777 if (copied >= target)
1781 * POSIX 1003.1g mandates this order.
1784 if ((err = sock_error(sk)) != 0)
1786 if (sk->sk_shutdown & RCV_SHUTDOWN)
1789 unix_state_unlock(sk);
1793 mutex_unlock(&u->readlock);
1795 timeo = unix_stream_data_wait(sk, timeo);
1797 if (signal_pending(current)) {
1798 err = sock_intr_errno(timeo);
1801 mutex_lock(&u->readlock);
1804 unix_state_unlock(sk);
1807 unix_state_unlock(sk);
1810 /* Never glue messages from different writers */
1811 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1812 skb_queue_head(&sk->sk_receive_queue, skb);
1816 /* Copy credentials */
1817 siocb->scm->creds = *UNIXCREDS(skb);
1821 /* Copy address just once */
1824 unix_copy_addr(msg, skb->sk);
1828 chunk = min_t(unsigned int, skb->len, size);
1829 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1830 skb_queue_head(&sk->sk_receive_queue, skb);
1838 /* Mark read part of skb as used */
1839 if (!(flags & MSG_PEEK))
1841 skb_pull(skb, chunk);
1844 unix_detach_fds(siocb->scm, skb);
1846 /* put the skb back if we didn't use it up.. */
1849 skb_queue_head(&sk->sk_receive_queue, skb);
1860 /* It is questionable, see note in unix_dgram_recvmsg.
1863 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1865 /* put message back and return */
1866 skb_queue_head(&sk->sk_receive_queue, skb);
1871 mutex_unlock(&u->readlock);
1872 scm_recv(sock, msg, siocb->scm, flags);
1874 return copied ? : err;
1877 static int unix_shutdown(struct socket *sock, int mode)
1879 struct sock *sk = sock->sk;
1882 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1885 unix_state_lock(sk);
1886 sk->sk_shutdown |= mode;
1887 other=unix_peer(sk);
1890 unix_state_unlock(sk);
1891 sk->sk_state_change(sk);
1894 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1898 if (mode&RCV_SHUTDOWN)
1899 peer_mode |= SEND_SHUTDOWN;
1900 if (mode&SEND_SHUTDOWN)
1901 peer_mode |= RCV_SHUTDOWN;
1902 unix_state_lock(other);
1903 other->sk_shutdown |= peer_mode;
1904 unix_state_unlock(other);
1905 other->sk_state_change(other);
1906 read_lock(&other->sk_callback_lock);
1907 if (peer_mode == SHUTDOWN_MASK)
1908 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
1909 else if (peer_mode & RCV_SHUTDOWN)
1910 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
1911 read_unlock(&other->sk_callback_lock);
1919 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1921 struct sock *sk = sock->sk;
1928 amount = atomic_read(&sk->sk_wmem_alloc);
1929 err = put_user(amount, (int __user *)arg);
1933 struct sk_buff *skb;
1935 if (sk->sk_state == TCP_LISTEN) {
1940 spin_lock(&sk->sk_receive_queue.lock);
1941 if (sk->sk_type == SOCK_STREAM ||
1942 sk->sk_type == SOCK_SEQPACKET) {
1943 skb_queue_walk(&sk->sk_receive_queue, skb)
1946 skb = skb_peek(&sk->sk_receive_queue);
1950 spin_unlock(&sk->sk_receive_queue.lock);
1951 err = put_user(amount, (int __user *)arg);
1962 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1964 struct sock *sk = sock->sk;
1967 poll_wait(file, sk->sk_sleep, wait);
1970 /* exceptional events? */
1973 if (sk->sk_shutdown == SHUTDOWN_MASK)
1975 if (sk->sk_shutdown & RCV_SHUTDOWN)
1979 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1980 (sk->sk_shutdown & RCV_SHUTDOWN))
1981 mask |= POLLIN | POLLRDNORM;
1983 /* Connection-based need to check for termination and startup */
1984 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
1988 * we set writable also when the other side has shut down the
1989 * connection. This prevents stuck sockets.
1991 if (unix_writable(sk))
1992 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1997 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2000 struct sock *sk = sock->sk, *other;
2001 unsigned int mask, writable;
2003 poll_wait(file, sk->sk_sleep, wait);
2006 /* exceptional events? */
2007 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2009 if (sk->sk_shutdown & RCV_SHUTDOWN)
2011 if (sk->sk_shutdown == SHUTDOWN_MASK)
2015 if (!skb_queue_empty(&sk->sk_receive_queue) ||
2016 (sk->sk_shutdown & RCV_SHUTDOWN))
2017 mask |= POLLIN | POLLRDNORM;
2019 /* Connection-based need to check for termination and startup */
2020 if (sk->sk_type == SOCK_SEQPACKET) {
2021 if (sk->sk_state == TCP_CLOSE)
2023 /* connection hasn't started yet? */
2024 if (sk->sk_state == TCP_SYN_SENT)
2029 writable = unix_writable(sk);
2031 other = unix_peer_get(sk);
2033 if (unix_peer(other) != sk) {
2034 poll_wait(file, &unix_sk(other)->peer_wait,
2036 if (unix_recvq_full(other))
2045 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2047 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2052 #ifdef CONFIG_PROC_FS
2053 static struct sock *first_unix_socket(int *i)
2055 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
2056 if (!hlist_empty(&unix_socket_table[*i]))
2057 return __sk_head(&unix_socket_table[*i]);
2062 static struct sock *next_unix_socket(int *i, struct sock *s)
2064 struct sock *next = sk_next(s);
2065 /* More in this chain? */
2068 /* Look for next non-empty chain. */
2069 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
2070 if (!hlist_empty(&unix_socket_table[*i]))
2071 return __sk_head(&unix_socket_table[*i]);
2076 struct unix_iter_state {
2077 struct seq_net_private p;
2080 static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
2082 struct unix_iter_state *iter = seq->private;
2086 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
2087 if (sock_net(s) != seq_file_net(seq))
2097 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2098 __acquires(unix_table_lock)
2100 spin_lock(&unix_table_lock);
2101 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2104 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2106 struct unix_iter_state *iter = seq->private;
2107 struct sock *sk = v;
2110 if (v == SEQ_START_TOKEN)
2111 sk = first_unix_socket(&iter->i);
2113 sk = next_unix_socket(&iter->i, sk);
2114 while (sk && (sock_net(sk) != seq_file_net(seq)))
2115 sk = next_unix_socket(&iter->i, sk);
2119 static void unix_seq_stop(struct seq_file *seq, void *v)
2120 __releases(unix_table_lock)
2122 spin_unlock(&unix_table_lock);
2125 static int unix_seq_show(struct seq_file *seq, void *v)
2128 if (v == SEQ_START_TOKEN)
2129 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2133 struct unix_sock *u = unix_sk(s);
2136 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2138 atomic_read(&s->sk_refcnt),
2140 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2143 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2144 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2152 len = u->addr->len - sizeof(short);
2153 if (!UNIX_ABSTRACT(s))
2159 for ( ; i < len; i++)
2160 seq_putc(seq, u->addr->name->sun_path[i]);
2162 unix_state_unlock(s);
2163 seq_putc(seq, '\n');
2169 static const struct seq_operations unix_seq_ops = {
2170 .start = unix_seq_start,
2171 .next = unix_seq_next,
2172 .stop = unix_seq_stop,
2173 .show = unix_seq_show,
2177 static int unix_seq_open(struct inode *inode, struct file *file)
2179 return seq_open_net(inode, file, &unix_seq_ops,
2180 sizeof(struct unix_iter_state));
2183 static const struct file_operations unix_seq_fops = {
2184 .owner = THIS_MODULE,
2185 .open = unix_seq_open,
2187 .llseek = seq_lseek,
2188 .release = seq_release_net,
2193 static struct net_proto_family unix_family_ops = {
2195 .create = unix_create,
2196 .owner = THIS_MODULE,
2200 static int unix_net_init(struct net *net)
2202 int error = -ENOMEM;
2204 net->unx.sysctl_max_dgram_qlen = 10;
2205 if (unix_sysctl_register(net))
2208 #ifdef CONFIG_PROC_FS
2209 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2210 unix_sysctl_unregister(net);
2219 static void unix_net_exit(struct net *net)
2221 unix_sysctl_unregister(net);
2222 proc_net_remove(net, "unix");
2225 static struct pernet_operations unix_net_ops = {
2226 .init = unix_net_init,
2227 .exit = unix_net_exit,
2230 static int __init af_unix_init(void)
2233 struct sk_buff *dummy_skb;
2235 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2237 rc = proto_register(&unix_proto, 1);
2239 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2244 sock_register(&unix_family_ops);
2245 register_pernet_subsys(&unix_net_ops);
2250 static void __exit af_unix_exit(void)
2252 sock_unregister(PF_UNIX);
2253 proto_unregister(&unix_proto);
2254 unregister_pernet_subsys(&unix_net_ops);
2257 /* Earlier than device_initcall() so that other drivers invoking
2258 request_module() don't end up in a loop when modprobe tries
2259 to use a UNIX socket. But later than subsys_initcall() because
2260 we depend on stuff initialised there */
2261 fs_initcall(af_unix_init);
2262 module_exit(af_unix_exit);
2264 MODULE_LICENSE("GPL");
2265 MODULE_ALIAS_NETPROTO(PF_UNIX);