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ipv4: fix checkpatch errors
[deliverable/linux.git] / net / unix / af_unix.c
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1/*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
4 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
5 *
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.
10 *
11 * Fixes:
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
21 * Mike Shaver's work.
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
28 * reference counting
29 * Kirk Petersen : Made this a module
30 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
31 * Lots of bug fixes.
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
43 * dgram receiver.
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+)
51 *
52 *
53 * Known differences from reference BSD that was tested:
54 *
55 * [TO FIX]
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).
60 * [NOT TO FIX]
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)
68 *
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.
73 *
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
80 * with BSD names.
81 */
82
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>
93#include <linux/un.h>
94#include <linux/fcntl.h>
95#include <linux/termios.h>
96#include <linux/sockios.h>
97#include <linux/net.h>
98#include <linux/in.h>
99#include <linux/fs.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>
110#include <net/scm.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>
117
118struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
119EXPORT_SYMBOL_GPL(unix_socket_table);
120DEFINE_SPINLOCK(unix_table_lock);
121EXPORT_SYMBOL_GPL(unix_table_lock);
122static atomic_long_t unix_nr_socks;
123
124#define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
125
126#define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
127
128#ifdef CONFIG_SECURITY_NETWORK
129static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
130{
131 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
132}
133
134static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
135{
136 scm->secid = *UNIXSID(skb);
137}
138#else
139static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
140{ }
141
142static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
143{ }
144#endif /* CONFIG_SECURITY_NETWORK */
145
146/*
147 * SMP locking strategy:
148 * hash table is protected with spinlock unix_table_lock
149 * each socket state is protected by separate spin lock.
150 */
151
152static inline unsigned unix_hash_fold(__wsum n)
153{
154 unsigned hash = (__force unsigned)n;
155 hash ^= hash>>16;
156 hash ^= hash>>8;
157 return hash&(UNIX_HASH_SIZE-1);
158}
159
160#define unix_peer(sk) (unix_sk(sk)->peer)
161
162static inline int unix_our_peer(struct sock *sk, struct sock *osk)
163{
164 return unix_peer(osk) == sk;
165}
166
167static inline int unix_may_send(struct sock *sk, struct sock *osk)
168{
169 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
170}
171
172static inline int unix_recvq_full(struct sock const *sk)
173{
174 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
175}
176
177struct sock *unix_peer_get(struct sock *s)
178{
179 struct sock *peer;
180
181 unix_state_lock(s);
182 peer = unix_peer(s);
183 if (peer)
184 sock_hold(peer);
185 unix_state_unlock(s);
186 return peer;
187}
188EXPORT_SYMBOL_GPL(unix_peer_get);
189
190static inline void unix_release_addr(struct unix_address *addr)
191{
192 if (atomic_dec_and_test(&addr->refcnt))
193 kfree(addr);
194}
195
196/*
197 * Check unix socket name:
198 * - should be not zero length.
199 * - if started by not zero, should be NULL terminated (FS object)
200 * - if started by zero, it is abstract name.
201 */
202
203static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned *hashp)
204{
205 if (len <= sizeof(short) || len > sizeof(*sunaddr))
206 return -EINVAL;
207 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
208 return -EINVAL;
209 if (sunaddr->sun_path[0]) {
210 /*
211 * This may look like an off by one error but it is a bit more
212 * subtle. 108 is the longest valid AF_UNIX path for a binding.
213 * sun_path[108] doesn't as such exist. However in kernel space
214 * we are guaranteed that it is a valid memory location in our
215 * kernel address buffer.
216 */
217 ((char *)sunaddr)[len] = 0;
218 len = strlen(sunaddr->sun_path)+1+sizeof(short);
219 return len;
220 }
221
222 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
223 return len;
224}
225
226static void __unix_remove_socket(struct sock *sk)
227{
228 sk_del_node_init(sk);
229}
230
231static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
232{
233 WARN_ON(!sk_unhashed(sk));
234 sk_add_node(sk, list);
235}
236
237static inline void unix_remove_socket(struct sock *sk)
238{
239 spin_lock(&unix_table_lock);
240 __unix_remove_socket(sk);
241 spin_unlock(&unix_table_lock);
242}
243
244static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
245{
246 spin_lock(&unix_table_lock);
247 __unix_insert_socket(list, sk);
248 spin_unlock(&unix_table_lock);
249}
250
251static struct sock *__unix_find_socket_byname(struct net *net,
252 struct sockaddr_un *sunname,
253 int len, int type, unsigned hash)
254{
255 struct sock *s;
256 struct hlist_node *node;
257
258 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
259 struct unix_sock *u = unix_sk(s);
260
261 if (!net_eq(sock_net(s), net))
262 continue;
263
264 if (u->addr->len == len &&
265 !memcmp(u->addr->name, sunname, len))
266 goto found;
267 }
268 s = NULL;
269found:
270 return s;
271}
272
273static inline struct sock *unix_find_socket_byname(struct net *net,
274 struct sockaddr_un *sunname,
275 int len, int type,
276 unsigned hash)
277{
278 struct sock *s;
279
280 spin_lock(&unix_table_lock);
281 s = __unix_find_socket_byname(net, sunname, len, type, hash);
282 if (s)
283 sock_hold(s);
284 spin_unlock(&unix_table_lock);
285 return s;
286}
287
288static struct sock *unix_find_socket_byinode(struct inode *i)
289{
290 struct sock *s;
291 struct hlist_node *node;
292
293 spin_lock(&unix_table_lock);
294 sk_for_each(s, node,
295 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
296 struct dentry *dentry = unix_sk(s)->path.dentry;
297
298 if (dentry && dentry->d_inode == i) {
299 sock_hold(s);
300 goto found;
301 }
302 }
303 s = NULL;
304found:
305 spin_unlock(&unix_table_lock);
306 return s;
307}
308
309static inline int unix_writable(struct sock *sk)
310{
311 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
312}
313
314static void unix_write_space(struct sock *sk)
315{
316 struct socket_wq *wq;
317
318 rcu_read_lock();
319 if (unix_writable(sk)) {
320 wq = rcu_dereference(sk->sk_wq);
321 if (wq_has_sleeper(wq))
322 wake_up_interruptible_sync_poll(&wq->wait,
323 POLLOUT | POLLWRNORM | POLLWRBAND);
324 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
325 }
326 rcu_read_unlock();
327}
328
329/* When dgram socket disconnects (or changes its peer), we clear its receive
330 * queue of packets arrived from previous peer. First, it allows to do
331 * flow control based only on wmem_alloc; second, sk connected to peer
332 * may receive messages only from that peer. */
333static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
334{
335 if (!skb_queue_empty(&sk->sk_receive_queue)) {
336 skb_queue_purge(&sk->sk_receive_queue);
337 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
338
339 /* If one link of bidirectional dgram pipe is disconnected,
340 * we signal error. Messages are lost. Do not make this,
341 * when peer was not connected to us.
342 */
343 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
344 other->sk_err = ECONNRESET;
345 other->sk_error_report(other);
346 }
347 }
348}
349
350static void unix_sock_destructor(struct sock *sk)
351{
352 struct unix_sock *u = unix_sk(sk);
353
354 skb_queue_purge(&sk->sk_receive_queue);
355
356 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
357 WARN_ON(!sk_unhashed(sk));
358 WARN_ON(sk->sk_socket);
359 if (!sock_flag(sk, SOCK_DEAD)) {
360 printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk);
361 return;
362 }
363
364 if (u->addr)
365 unix_release_addr(u->addr);
366
367 atomic_long_dec(&unix_nr_socks);
368 local_bh_disable();
369 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
370 local_bh_enable();
371#ifdef UNIX_REFCNT_DEBUG
372 printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk,
373 atomic_long_read(&unix_nr_socks));
374#endif
375}
376
377static int unix_release_sock(struct sock *sk, int embrion)
378{
379 struct unix_sock *u = unix_sk(sk);
380 struct path path;
381 struct sock *skpair;
382 struct sk_buff *skb;
383 int state;
384
385 unix_remove_socket(sk);
386
387 /* Clear state */
388 unix_state_lock(sk);
389 sock_orphan(sk);
390 sk->sk_shutdown = SHUTDOWN_MASK;
391 path = u->path;
392 u->path.dentry = NULL;
393 u->path.mnt = NULL;
394 state = sk->sk_state;
395 sk->sk_state = TCP_CLOSE;
396 unix_state_unlock(sk);
397
398 wake_up_interruptible_all(&u->peer_wait);
399
400 skpair = unix_peer(sk);
401
402 if (skpair != NULL) {
403 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
404 unix_state_lock(skpair);
405 /* No more writes */
406 skpair->sk_shutdown = SHUTDOWN_MASK;
407 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
408 skpair->sk_err = ECONNRESET;
409 unix_state_unlock(skpair);
410 skpair->sk_state_change(skpair);
411 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
412 }
413 sock_put(skpair); /* It may now die */
414 unix_peer(sk) = NULL;
415 }
416
417 /* Try to flush out this socket. Throw out buffers at least */
418
419 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
420 if (state == TCP_LISTEN)
421 unix_release_sock(skb->sk, 1);
422 /* passed fds are erased in the kfree_skb hook */
423 kfree_skb(skb);
424 }
425
426 if (path.dentry)
427 path_put(&path);
428
429 sock_put(sk);
430
431 /* ---- Socket is dead now and most probably destroyed ---- */
432
433 /*
434 * Fixme: BSD difference: In BSD all sockets connected to use get
435 * ECONNRESET and we die on the spot. In Linux we behave
436 * like files and pipes do and wait for the last
437 * dereference.
438 *
439 * Can't we simply set sock->err?
440 *
441 * What the above comment does talk about? --ANK(980817)
442 */
443
444 if (unix_tot_inflight)
445 unix_gc(); /* Garbage collect fds */
446
447 return 0;
448}
449
450static void init_peercred(struct sock *sk)
451{
452 put_pid(sk->sk_peer_pid);
453 if (sk->sk_peer_cred)
454 put_cred(sk->sk_peer_cred);
455 sk->sk_peer_pid = get_pid(task_tgid(current));
456 sk->sk_peer_cred = get_current_cred();
457}
458
459static void copy_peercred(struct sock *sk, struct sock *peersk)
460{
461 put_pid(sk->sk_peer_pid);
462 if (sk->sk_peer_cred)
463 put_cred(sk->sk_peer_cred);
464 sk->sk_peer_pid = get_pid(peersk->sk_peer_pid);
465 sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
466}
467
468static int unix_listen(struct socket *sock, int backlog)
469{
470 int err;
471 struct sock *sk = sock->sk;
472 struct unix_sock *u = unix_sk(sk);
473 struct pid *old_pid = NULL;
474 const struct cred *old_cred = NULL;
475
476 err = -EOPNOTSUPP;
477 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
478 goto out; /* Only stream/seqpacket sockets accept */
479 err = -EINVAL;
480 if (!u->addr)
481 goto out; /* No listens on an unbound socket */
482 unix_state_lock(sk);
483 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
484 goto out_unlock;
485 if (backlog > sk->sk_max_ack_backlog)
486 wake_up_interruptible_all(&u->peer_wait);
487 sk->sk_max_ack_backlog = backlog;
488 sk->sk_state = TCP_LISTEN;
489 /* set credentials so connect can copy them */
490 init_peercred(sk);
491 err = 0;
492
493out_unlock:
494 unix_state_unlock(sk);
495 put_pid(old_pid);
496 if (old_cred)
497 put_cred(old_cred);
498out:
499 return err;
500}
501
502static int unix_release(struct socket *);
503static int unix_bind(struct socket *, struct sockaddr *, int);
504static int unix_stream_connect(struct socket *, struct sockaddr *,
505 int addr_len, int flags);
506static int unix_socketpair(struct socket *, struct socket *);
507static int unix_accept(struct socket *, struct socket *, int);
508static int unix_getname(struct socket *, struct sockaddr *, int *, int);
509static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
510static unsigned int unix_dgram_poll(struct file *, struct socket *,
511 poll_table *);
512static int unix_ioctl(struct socket *, unsigned int, unsigned long);
513static int unix_shutdown(struct socket *, int);
514static int unix_stream_sendmsg(struct kiocb *, struct socket *,
515 struct msghdr *, size_t);
516static int unix_stream_recvmsg(struct kiocb *, struct socket *,
517 struct msghdr *, size_t, int);
518static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
519 struct msghdr *, size_t);
520static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
521 struct msghdr *, size_t, int);
522static int unix_dgram_connect(struct socket *, struct sockaddr *,
523 int, int);
524static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
525 struct msghdr *, size_t);
526static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *,
527 struct msghdr *, size_t, int);
528
529static void unix_set_peek_off(struct sock *sk, int val)
530{
531 struct unix_sock *u = unix_sk(sk);
532
533 mutex_lock(&u->readlock);
534 sk->sk_peek_off = val;
535 mutex_unlock(&u->readlock);
536}
537
538
539static const struct proto_ops unix_stream_ops = {
540 .family = PF_UNIX,
541 .owner = THIS_MODULE,
542 .release = unix_release,
543 .bind = unix_bind,
544 .connect = unix_stream_connect,
545 .socketpair = unix_socketpair,
546 .accept = unix_accept,
547 .getname = unix_getname,
548 .poll = unix_poll,
549 .ioctl = unix_ioctl,
550 .listen = unix_listen,
551 .shutdown = unix_shutdown,
552 .setsockopt = sock_no_setsockopt,
553 .getsockopt = sock_no_getsockopt,
554 .sendmsg = unix_stream_sendmsg,
555 .recvmsg = unix_stream_recvmsg,
556 .mmap = sock_no_mmap,
557 .sendpage = sock_no_sendpage,
558 .set_peek_off = unix_set_peek_off,
559};
560
561static const struct proto_ops unix_dgram_ops = {
562 .family = PF_UNIX,
563 .owner = THIS_MODULE,
564 .release = unix_release,
565 .bind = unix_bind,
566 .connect = unix_dgram_connect,
567 .socketpair = unix_socketpair,
568 .accept = sock_no_accept,
569 .getname = unix_getname,
570 .poll = unix_dgram_poll,
571 .ioctl = unix_ioctl,
572 .listen = sock_no_listen,
573 .shutdown = unix_shutdown,
574 .setsockopt = sock_no_setsockopt,
575 .getsockopt = sock_no_getsockopt,
576 .sendmsg = unix_dgram_sendmsg,
577 .recvmsg = unix_dgram_recvmsg,
578 .mmap = sock_no_mmap,
579 .sendpage = sock_no_sendpage,
580 .set_peek_off = unix_set_peek_off,
581};
582
583static const struct proto_ops unix_seqpacket_ops = {
584 .family = PF_UNIX,
585 .owner = THIS_MODULE,
586 .release = unix_release,
587 .bind = unix_bind,
588 .connect = unix_stream_connect,
589 .socketpair = unix_socketpair,
590 .accept = unix_accept,
591 .getname = unix_getname,
592 .poll = unix_dgram_poll,
593 .ioctl = unix_ioctl,
594 .listen = unix_listen,
595 .shutdown = unix_shutdown,
596 .setsockopt = sock_no_setsockopt,
597 .getsockopt = sock_no_getsockopt,
598 .sendmsg = unix_seqpacket_sendmsg,
599 .recvmsg = unix_seqpacket_recvmsg,
600 .mmap = sock_no_mmap,
601 .sendpage = sock_no_sendpage,
602 .set_peek_off = unix_set_peek_off,
603};
604
605static struct proto unix_proto = {
606 .name = "UNIX",
607 .owner = THIS_MODULE,
608 .obj_size = sizeof(struct unix_sock),
609};
610
611/*
612 * AF_UNIX sockets do not interact with hardware, hence they
613 * dont trigger interrupts - so it's safe for them to have
614 * bh-unsafe locking for their sk_receive_queue.lock. Split off
615 * this special lock-class by reinitializing the spinlock key:
616 */
617static struct lock_class_key af_unix_sk_receive_queue_lock_key;
618
619static struct sock *unix_create1(struct net *net, struct socket *sock)
620{
621 struct sock *sk = NULL;
622 struct unix_sock *u;
623
624 atomic_long_inc(&unix_nr_socks);
625 if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
626 goto out;
627
628 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
629 if (!sk)
630 goto out;
631
632 sock_init_data(sock, sk);
633 lockdep_set_class(&sk->sk_receive_queue.lock,
634 &af_unix_sk_receive_queue_lock_key);
635
636 sk->sk_write_space = unix_write_space;
637 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
638 sk->sk_destruct = unix_sock_destructor;
639 u = unix_sk(sk);
640 u->path.dentry = NULL;
641 u->path.mnt = NULL;
642 spin_lock_init(&u->lock);
643 atomic_long_set(&u->inflight, 0);
644 INIT_LIST_HEAD(&u->link);
645 mutex_init(&u->readlock); /* single task reading lock */
646 init_waitqueue_head(&u->peer_wait);
647 unix_insert_socket(unix_sockets_unbound, sk);
648out:
649 if (sk == NULL)
650 atomic_long_dec(&unix_nr_socks);
651 else {
652 local_bh_disable();
653 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
654 local_bh_enable();
655 }
656 return sk;
657}
658
659static int unix_create(struct net *net, struct socket *sock, int protocol,
660 int kern)
661{
662 if (protocol && protocol != PF_UNIX)
663 return -EPROTONOSUPPORT;
664
665 sock->state = SS_UNCONNECTED;
666
667 switch (sock->type) {
668 case SOCK_STREAM:
669 sock->ops = &unix_stream_ops;
670 break;
671 /*
672 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
673 * nothing uses it.
674 */
675 case SOCK_RAW:
676 sock->type = SOCK_DGRAM;
677 case SOCK_DGRAM:
678 sock->ops = &unix_dgram_ops;
679 break;
680 case SOCK_SEQPACKET:
681 sock->ops = &unix_seqpacket_ops;
682 break;
683 default:
684 return -ESOCKTNOSUPPORT;
685 }
686
687 return unix_create1(net, sock) ? 0 : -ENOMEM;
688}
689
690static int unix_release(struct socket *sock)
691{
692 struct sock *sk = sock->sk;
693
694 if (!sk)
695 return 0;
696
697 sock->sk = NULL;
698
699 return unix_release_sock(sk, 0);
700}
701
702static int unix_autobind(struct socket *sock)
703{
704 struct sock *sk = sock->sk;
705 struct net *net = sock_net(sk);
706 struct unix_sock *u = unix_sk(sk);
707 static u32 ordernum = 1;
708 struct unix_address *addr;
709 int err;
710 unsigned int retries = 0;
711
712 mutex_lock(&u->readlock);
713
714 err = 0;
715 if (u->addr)
716 goto out;
717
718 err = -ENOMEM;
719 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
720 if (!addr)
721 goto out;
722
723 addr->name->sun_family = AF_UNIX;
724 atomic_set(&addr->refcnt, 1);
725
726retry:
727 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
728 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
729
730 spin_lock(&unix_table_lock);
731 ordernum = (ordernum+1)&0xFFFFF;
732
733 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
734 addr->hash)) {
735 spin_unlock(&unix_table_lock);
736 /*
737 * __unix_find_socket_byname() may take long time if many names
738 * are already in use.
739 */
740 cond_resched();
741 /* Give up if all names seems to be in use. */
742 if (retries++ == 0xFFFFF) {
743 err = -ENOSPC;
744 kfree(addr);
745 goto out;
746 }
747 goto retry;
748 }
749 addr->hash ^= sk->sk_type;
750
751 __unix_remove_socket(sk);
752 u->addr = addr;
753 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
754 spin_unlock(&unix_table_lock);
755 err = 0;
756
757out: mutex_unlock(&u->readlock);
758 return err;
759}
760
761static struct sock *unix_find_other(struct net *net,
762 struct sockaddr_un *sunname, int len,
763 int type, unsigned hash, int *error)
764{
765 struct sock *u;
766 struct path path;
767 int err = 0;
768
769 if (sunname->sun_path[0]) {
770 struct inode *inode;
771 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
772 if (err)
773 goto fail;
774 inode = path.dentry->d_inode;
775 err = inode_permission(inode, MAY_WRITE);
776 if (err)
777 goto put_fail;
778
779 err = -ECONNREFUSED;
780 if (!S_ISSOCK(inode->i_mode))
781 goto put_fail;
782 u = unix_find_socket_byinode(inode);
783 if (!u)
784 goto put_fail;
785
786 if (u->sk_type == type)
787 touch_atime(&path);
788
789 path_put(&path);
790
791 err = -EPROTOTYPE;
792 if (u->sk_type != type) {
793 sock_put(u);
794 goto fail;
795 }
796 } else {
797 err = -ECONNREFUSED;
798 u = unix_find_socket_byname(net, sunname, len, type, hash);
799 if (u) {
800 struct dentry *dentry;
801 dentry = unix_sk(u)->path.dentry;
802 if (dentry)
803 touch_atime(&unix_sk(u)->path);
804 } else
805 goto fail;
806 }
807 return u;
808
809put_fail:
810 path_put(&path);
811fail:
812 *error = err;
813 return NULL;
814}
815
816
817static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
818{
819 struct sock *sk = sock->sk;
820 struct net *net = sock_net(sk);
821 struct unix_sock *u = unix_sk(sk);
822 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
823 char *sun_path = sunaddr->sun_path;
824 struct dentry *dentry = NULL;
825 struct path path;
826 int err;
827 unsigned hash;
828 struct unix_address *addr;
829 struct hlist_head *list;
830
831 err = -EINVAL;
832 if (sunaddr->sun_family != AF_UNIX)
833 goto out;
834
835 if (addr_len == sizeof(short)) {
836 err = unix_autobind(sock);
837 goto out;
838 }
839
840 err = unix_mkname(sunaddr, addr_len, &hash);
841 if (err < 0)
842 goto out;
843 addr_len = err;
844
845 mutex_lock(&u->readlock);
846
847 err = -EINVAL;
848 if (u->addr)
849 goto out_up;
850
851 err = -ENOMEM;
852 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
853 if (!addr)
854 goto out_up;
855
856 memcpy(addr->name, sunaddr, addr_len);
857 addr->len = addr_len;
858 addr->hash = hash ^ sk->sk_type;
859 atomic_set(&addr->refcnt, 1);
860
861 if (sun_path[0]) {
862 umode_t mode;
863 err = 0;
864 /*
865 * Get the parent directory, calculate the hash for last
866 * component.
867 */
868 dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
869 err = PTR_ERR(dentry);
870 if (IS_ERR(dentry))
871 goto out_mknod_parent;
872
873 /*
874 * All right, let's create it.
875 */
876 mode = S_IFSOCK |
877 (SOCK_INODE(sock)->i_mode & ~current_umask());
878 err = mnt_want_write(path.mnt);
879 if (err)
880 goto out_mknod_dput;
881 err = security_path_mknod(&path, dentry, mode, 0);
882 if (err)
883 goto out_mknod_drop_write;
884 err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0);
885out_mknod_drop_write:
886 mnt_drop_write(path.mnt);
887 if (err)
888 goto out_mknod_dput;
889 mutex_unlock(&path.dentry->d_inode->i_mutex);
890 dput(path.dentry);
891 path.dentry = dentry;
892
893 addr->hash = UNIX_HASH_SIZE;
894 }
895
896 spin_lock(&unix_table_lock);
897
898 if (!sun_path[0]) {
899 err = -EADDRINUSE;
900 if (__unix_find_socket_byname(net, sunaddr, addr_len,
901 sk->sk_type, hash)) {
902 unix_release_addr(addr);
903 goto out_unlock;
904 }
905
906 list = &unix_socket_table[addr->hash];
907 } else {
908 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
909 u->path = path;
910 }
911
912 err = 0;
913 __unix_remove_socket(sk);
914 u->addr = addr;
915 __unix_insert_socket(list, sk);
916
917out_unlock:
918 spin_unlock(&unix_table_lock);
919out_up:
920 mutex_unlock(&u->readlock);
921out:
922 return err;
923
924out_mknod_dput:
925 dput(dentry);
926 mutex_unlock(&path.dentry->d_inode->i_mutex);
927 path_put(&path);
928out_mknod_parent:
929 if (err == -EEXIST)
930 err = -EADDRINUSE;
931 unix_release_addr(addr);
932 goto out_up;
933}
934
935static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
936{
937 if (unlikely(sk1 == sk2) || !sk2) {
938 unix_state_lock(sk1);
939 return;
940 }
941 if (sk1 < sk2) {
942 unix_state_lock(sk1);
943 unix_state_lock_nested(sk2);
944 } else {
945 unix_state_lock(sk2);
946 unix_state_lock_nested(sk1);
947 }
948}
949
950static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
951{
952 if (unlikely(sk1 == sk2) || !sk2) {
953 unix_state_unlock(sk1);
954 return;
955 }
956 unix_state_unlock(sk1);
957 unix_state_unlock(sk2);
958}
959
960static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
961 int alen, int flags)
962{
963 struct sock *sk = sock->sk;
964 struct net *net = sock_net(sk);
965 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
966 struct sock *other;
967 unsigned hash;
968 int err;
969
970 if (addr->sa_family != AF_UNSPEC) {
971 err = unix_mkname(sunaddr, alen, &hash);
972 if (err < 0)
973 goto out;
974 alen = err;
975
976 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
977 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
978 goto out;
979
980restart:
981 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
982 if (!other)
983 goto out;
984
985 unix_state_double_lock(sk, other);
986
987 /* Apparently VFS overslept socket death. Retry. */
988 if (sock_flag(other, SOCK_DEAD)) {
989 unix_state_double_unlock(sk, other);
990 sock_put(other);
991 goto restart;
992 }
993
994 err = -EPERM;
995 if (!unix_may_send(sk, other))
996 goto out_unlock;
997
998 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
999 if (err)
1000 goto out_unlock;
1001
1002 } else {
1003 /*
1004 * 1003.1g breaking connected state with AF_UNSPEC
1005 */
1006 other = NULL;
1007 unix_state_double_lock(sk, other);
1008 }
1009
1010 /*
1011 * If it was connected, reconnect.
1012 */
1013 if (unix_peer(sk)) {
1014 struct sock *old_peer = unix_peer(sk);
1015 unix_peer(sk) = other;
1016 unix_state_double_unlock(sk, other);
1017
1018 if (other != old_peer)
1019 unix_dgram_disconnected(sk, old_peer);
1020 sock_put(old_peer);
1021 } else {
1022 unix_peer(sk) = other;
1023 unix_state_double_unlock(sk, other);
1024 }
1025 return 0;
1026
1027out_unlock:
1028 unix_state_double_unlock(sk, other);
1029 sock_put(other);
1030out:
1031 return err;
1032}
1033
1034static long unix_wait_for_peer(struct sock *other, long timeo)
1035{
1036 struct unix_sock *u = unix_sk(other);
1037 int sched;
1038 DEFINE_WAIT(wait);
1039
1040 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1041
1042 sched = !sock_flag(other, SOCK_DEAD) &&
1043 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1044 unix_recvq_full(other);
1045
1046 unix_state_unlock(other);
1047
1048 if (sched)
1049 timeo = schedule_timeout(timeo);
1050
1051 finish_wait(&u->peer_wait, &wait);
1052 return timeo;
1053}
1054
1055static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1056 int addr_len, int flags)
1057{
1058 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
1059 struct sock *sk = sock->sk;
1060 struct net *net = sock_net(sk);
1061 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1062 struct sock *newsk = NULL;
1063 struct sock *other = NULL;
1064 struct sk_buff *skb = NULL;
1065 unsigned hash;
1066 int st;
1067 int err;
1068 long timeo;
1069
1070 err = unix_mkname(sunaddr, addr_len, &hash);
1071 if (err < 0)
1072 goto out;
1073 addr_len = err;
1074
1075 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1076 (err = unix_autobind(sock)) != 0)
1077 goto out;
1078
1079 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1080
1081 /* First of all allocate resources.
1082 If we will make it after state is locked,
1083 we will have to recheck all again in any case.
1084 */
1085
1086 err = -ENOMEM;
1087
1088 /* create new sock for complete connection */
1089 newsk = unix_create1(sock_net(sk), NULL);
1090 if (newsk == NULL)
1091 goto out;
1092
1093 /* Allocate skb for sending to listening sock */
1094 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1095 if (skb == NULL)
1096 goto out;
1097
1098restart:
1099 /* Find listening sock. */
1100 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1101 if (!other)
1102 goto out;
1103
1104 /* Latch state of peer */
1105 unix_state_lock(other);
1106
1107 /* Apparently VFS overslept socket death. Retry. */
1108 if (sock_flag(other, SOCK_DEAD)) {
1109 unix_state_unlock(other);
1110 sock_put(other);
1111 goto restart;
1112 }
1113
1114 err = -ECONNREFUSED;
1115 if (other->sk_state != TCP_LISTEN)
1116 goto out_unlock;
1117 if (other->sk_shutdown & RCV_SHUTDOWN)
1118 goto out_unlock;
1119
1120 if (unix_recvq_full(other)) {
1121 err = -EAGAIN;
1122 if (!timeo)
1123 goto out_unlock;
1124
1125 timeo = unix_wait_for_peer(other, timeo);
1126
1127 err = sock_intr_errno(timeo);
1128 if (signal_pending(current))
1129 goto out;
1130 sock_put(other);
1131 goto restart;
1132 }
1133
1134 /* Latch our state.
1135
1136 It is tricky place. We need to grab our state lock and cannot
1137 drop lock on peer. It is dangerous because deadlock is
1138 possible. Connect to self case and simultaneous
1139 attempt to connect are eliminated by checking socket
1140 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1141 check this before attempt to grab lock.
1142
1143 Well, and we have to recheck the state after socket locked.
1144 */
1145 st = sk->sk_state;
1146
1147 switch (st) {
1148 case TCP_CLOSE:
1149 /* This is ok... continue with connect */
1150 break;
1151 case TCP_ESTABLISHED:
1152 /* Socket is already connected */
1153 err = -EISCONN;
1154 goto out_unlock;
1155 default:
1156 err = -EINVAL;
1157 goto out_unlock;
1158 }
1159
1160 unix_state_lock_nested(sk);
1161
1162 if (sk->sk_state != st) {
1163 unix_state_unlock(sk);
1164 unix_state_unlock(other);
1165 sock_put(other);
1166 goto restart;
1167 }
1168
1169 err = security_unix_stream_connect(sk, other, newsk);
1170 if (err) {
1171 unix_state_unlock(sk);
1172 goto out_unlock;
1173 }
1174
1175 /* The way is open! Fastly set all the necessary fields... */
1176
1177 sock_hold(sk);
1178 unix_peer(newsk) = sk;
1179 newsk->sk_state = TCP_ESTABLISHED;
1180 newsk->sk_type = sk->sk_type;
1181 init_peercred(newsk);
1182 newu = unix_sk(newsk);
1183 RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq);
1184 otheru = unix_sk(other);
1185
1186 /* copy address information from listening to new sock*/
1187 if (otheru->addr) {
1188 atomic_inc(&otheru->addr->refcnt);
1189 newu->addr = otheru->addr;
1190 }
1191 if (otheru->path.dentry) {
1192 path_get(&otheru->path);
1193 newu->path = otheru->path;
1194 }
1195
1196 /* Set credentials */
1197 copy_peercred(sk, other);
1198
1199 sock->state = SS_CONNECTED;
1200 sk->sk_state = TCP_ESTABLISHED;
1201 sock_hold(newsk);
1202
1203 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1204 unix_peer(sk) = newsk;
1205
1206 unix_state_unlock(sk);
1207
1208 /* take ten and and send info to listening sock */
1209 spin_lock(&other->sk_receive_queue.lock);
1210 __skb_queue_tail(&other->sk_receive_queue, skb);
1211 spin_unlock(&other->sk_receive_queue.lock);
1212 unix_state_unlock(other);
1213 other->sk_data_ready(other, 0);
1214 sock_put(other);
1215 return 0;
1216
1217out_unlock:
1218 if (other)
1219 unix_state_unlock(other);
1220
1221out:
1222 kfree_skb(skb);
1223 if (newsk)
1224 unix_release_sock(newsk, 0);
1225 if (other)
1226 sock_put(other);
1227 return err;
1228}
1229
1230static int unix_socketpair(struct socket *socka, struct socket *sockb)
1231{
1232 struct sock *ska = socka->sk, *skb = sockb->sk;
1233
1234 /* Join our sockets back to back */
1235 sock_hold(ska);
1236 sock_hold(skb);
1237 unix_peer(ska) = skb;
1238 unix_peer(skb) = ska;
1239 init_peercred(ska);
1240 init_peercred(skb);
1241
1242 if (ska->sk_type != SOCK_DGRAM) {
1243 ska->sk_state = TCP_ESTABLISHED;
1244 skb->sk_state = TCP_ESTABLISHED;
1245 socka->state = SS_CONNECTED;
1246 sockb->state = SS_CONNECTED;
1247 }
1248 return 0;
1249}
1250
1251static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1252{
1253 struct sock *sk = sock->sk;
1254 struct sock *tsk;
1255 struct sk_buff *skb;
1256 int err;
1257
1258 err = -EOPNOTSUPP;
1259 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
1260 goto out;
1261
1262 err = -EINVAL;
1263 if (sk->sk_state != TCP_LISTEN)
1264 goto out;
1265
1266 /* If socket state is TCP_LISTEN it cannot change (for now...),
1267 * so that no locks are necessary.
1268 */
1269
1270 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1271 if (!skb) {
1272 /* This means receive shutdown. */
1273 if (err == 0)
1274 err = -EINVAL;
1275 goto out;
1276 }
1277
1278 tsk = skb->sk;
1279 skb_free_datagram(sk, skb);
1280 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1281
1282 /* attach accepted sock to socket */
1283 unix_state_lock(tsk);
1284 newsock->state = SS_CONNECTED;
1285 sock_graft(tsk, newsock);
1286 unix_state_unlock(tsk);
1287 return 0;
1288
1289out:
1290 return err;
1291}
1292
1293
1294static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1295{
1296 struct sock *sk = sock->sk;
1297 struct unix_sock *u;
1298 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
1299 int err = 0;
1300
1301 if (peer) {
1302 sk = unix_peer_get(sk);
1303
1304 err = -ENOTCONN;
1305 if (!sk)
1306 goto out;
1307 err = 0;
1308 } else {
1309 sock_hold(sk);
1310 }
1311
1312 u = unix_sk(sk);
1313 unix_state_lock(sk);
1314 if (!u->addr) {
1315 sunaddr->sun_family = AF_UNIX;
1316 sunaddr->sun_path[0] = 0;
1317 *uaddr_len = sizeof(short);
1318 } else {
1319 struct unix_address *addr = u->addr;
1320
1321 *uaddr_len = addr->len;
1322 memcpy(sunaddr, addr->name, *uaddr_len);
1323 }
1324 unix_state_unlock(sk);
1325 sock_put(sk);
1326out:
1327 return err;
1328}
1329
1330static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1331{
1332 int i;
1333
1334 scm->fp = UNIXCB(skb).fp;
1335 UNIXCB(skb).fp = NULL;
1336
1337 for (i = scm->fp->count-1; i >= 0; i--)
1338 unix_notinflight(scm->fp->fp[i]);
1339}
1340
1341static void unix_destruct_scm(struct sk_buff *skb)
1342{
1343 struct scm_cookie scm;
1344 memset(&scm, 0, sizeof(scm));
1345 scm.pid = UNIXCB(skb).pid;
1346 scm.cred = UNIXCB(skb).cred;
1347 if (UNIXCB(skb).fp)
1348 unix_detach_fds(&scm, skb);
1349
1350 /* Alas, it calls VFS */
1351 /* So fscking what? fput() had been SMP-safe since the last Summer */
1352 scm_destroy(&scm);
1353 sock_wfree(skb);
1354}
1355
1356#define MAX_RECURSION_LEVEL 4
1357
1358static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1359{
1360 int i;
1361 unsigned char max_level = 0;
1362 int unix_sock_count = 0;
1363
1364 for (i = scm->fp->count - 1; i >= 0; i--) {
1365 struct sock *sk = unix_get_socket(scm->fp->fp[i]);
1366
1367 if (sk) {
1368 unix_sock_count++;
1369 max_level = max(max_level,
1370 unix_sk(sk)->recursion_level);
1371 }
1372 }
1373 if (unlikely(max_level > MAX_RECURSION_LEVEL))
1374 return -ETOOMANYREFS;
1375
1376 /*
1377 * Need to duplicate file references for the sake of garbage
1378 * collection. Otherwise a socket in the fps might become a
1379 * candidate for GC while the skb is not yet queued.
1380 */
1381 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1382 if (!UNIXCB(skb).fp)
1383 return -ENOMEM;
1384
1385 if (unix_sock_count) {
1386 for (i = scm->fp->count - 1; i >= 0; i--)
1387 unix_inflight(scm->fp->fp[i]);
1388 }
1389 return max_level;
1390}
1391
1392static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
1393{
1394 int err = 0;
1395
1396 UNIXCB(skb).pid = get_pid(scm->pid);
1397 if (scm->cred)
1398 UNIXCB(skb).cred = get_cred(scm->cred);
1399 UNIXCB(skb).fp = NULL;
1400 if (scm->fp && send_fds)
1401 err = unix_attach_fds(scm, skb);
1402
1403 skb->destructor = unix_destruct_scm;
1404 return err;
1405}
1406
1407/*
1408 * Some apps rely on write() giving SCM_CREDENTIALS
1409 * We include credentials if source or destination socket
1410 * asserted SOCK_PASSCRED.
1411 */
1412static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
1413 const struct sock *other)
1414{
1415 if (UNIXCB(skb).cred)
1416 return;
1417 if (test_bit(SOCK_PASSCRED, &sock->flags) ||
1418 !other->sk_socket ||
1419 test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
1420 UNIXCB(skb).pid = get_pid(task_tgid(current));
1421 UNIXCB(skb).cred = get_current_cred();
1422 }
1423}
1424
1425/*
1426 * Send AF_UNIX data.
1427 */
1428
1429static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1430 struct msghdr *msg, size_t len)
1431{
1432 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1433 struct sock *sk = sock->sk;
1434 struct net *net = sock_net(sk);
1435 struct unix_sock *u = unix_sk(sk);
1436 struct sockaddr_un *sunaddr = msg->msg_name;
1437 struct sock *other = NULL;
1438 int namelen = 0; /* fake GCC */
1439 int err;
1440 unsigned hash;
1441 struct sk_buff *skb;
1442 long timeo;
1443 struct scm_cookie tmp_scm;
1444 int max_level;
1445 int data_len = 0;
1446
1447 if (NULL == siocb->scm)
1448 siocb->scm = &tmp_scm;
1449 wait_for_unix_gc();
1450 err = scm_send(sock, msg, siocb->scm);
1451 if (err < 0)
1452 return err;
1453
1454 err = -EOPNOTSUPP;
1455 if (msg->msg_flags&MSG_OOB)
1456 goto out;
1457
1458 if (msg->msg_namelen) {
1459 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1460 if (err < 0)
1461 goto out;
1462 namelen = err;
1463 } else {
1464 sunaddr = NULL;
1465 err = -ENOTCONN;
1466 other = unix_peer_get(sk);
1467 if (!other)
1468 goto out;
1469 }
1470
1471 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1472 && (err = unix_autobind(sock)) != 0)
1473 goto out;
1474
1475 err = -EMSGSIZE;
1476 if (len > sk->sk_sndbuf - 32)
1477 goto out;
1478
1479 if (len > SKB_MAX_ALLOC)
1480 data_len = min_t(size_t,
1481 len - SKB_MAX_ALLOC,
1482 MAX_SKB_FRAGS * PAGE_SIZE);
1483
1484 skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
1485 msg->msg_flags & MSG_DONTWAIT, &err);
1486 if (skb == NULL)
1487 goto out;
1488
1489 err = unix_scm_to_skb(siocb->scm, skb, true);
1490 if (err < 0)
1491 goto out_free;
1492 max_level = err + 1;
1493 unix_get_secdata(siocb->scm, skb);
1494
1495 skb_put(skb, len - data_len);
1496 skb->data_len = data_len;
1497 skb->len = len;
1498 err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len);
1499 if (err)
1500 goto out_free;
1501
1502 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1503
1504restart:
1505 if (!other) {
1506 err = -ECONNRESET;
1507 if (sunaddr == NULL)
1508 goto out_free;
1509
1510 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1511 hash, &err);
1512 if (other == NULL)
1513 goto out_free;
1514 }
1515
1516 if (sk_filter(other, skb) < 0) {
1517 /* Toss the packet but do not return any error to the sender */
1518 err = len;
1519 goto out_free;
1520 }
1521
1522 unix_state_lock(other);
1523 err = -EPERM;
1524 if (!unix_may_send(sk, other))
1525 goto out_unlock;
1526
1527 if (sock_flag(other, SOCK_DEAD)) {
1528 /*
1529 * Check with 1003.1g - what should
1530 * datagram error
1531 */
1532 unix_state_unlock(other);
1533 sock_put(other);
1534
1535 err = 0;
1536 unix_state_lock(sk);
1537 if (unix_peer(sk) == other) {
1538 unix_peer(sk) = NULL;
1539 unix_state_unlock(sk);
1540
1541 unix_dgram_disconnected(sk, other);
1542 sock_put(other);
1543 err = -ECONNREFUSED;
1544 } else {
1545 unix_state_unlock(sk);
1546 }
1547
1548 other = NULL;
1549 if (err)
1550 goto out_free;
1551 goto restart;
1552 }
1553
1554 err = -EPIPE;
1555 if (other->sk_shutdown & RCV_SHUTDOWN)
1556 goto out_unlock;
1557
1558 if (sk->sk_type != SOCK_SEQPACKET) {
1559 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1560 if (err)
1561 goto out_unlock;
1562 }
1563
1564 if (unix_peer(other) != sk && unix_recvq_full(other)) {
1565 if (!timeo) {
1566 err = -EAGAIN;
1567 goto out_unlock;
1568 }
1569
1570 timeo = unix_wait_for_peer(other, timeo);
1571
1572 err = sock_intr_errno(timeo);
1573 if (signal_pending(current))
1574 goto out_free;
1575
1576 goto restart;
1577 }
1578
1579 if (sock_flag(other, SOCK_RCVTSTAMP))
1580 __net_timestamp(skb);
1581 maybe_add_creds(skb, sock, other);
1582 skb_queue_tail(&other->sk_receive_queue, skb);
1583 if (max_level > unix_sk(other)->recursion_level)
1584 unix_sk(other)->recursion_level = max_level;
1585 unix_state_unlock(other);
1586 other->sk_data_ready(other, len);
1587 sock_put(other);
1588 scm_destroy(siocb->scm);
1589 return len;
1590
1591out_unlock:
1592 unix_state_unlock(other);
1593out_free:
1594 kfree_skb(skb);
1595out:
1596 if (other)
1597 sock_put(other);
1598 scm_destroy(siocb->scm);
1599 return err;
1600}
1601
1602
1603static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1604 struct msghdr *msg, size_t len)
1605{
1606 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1607 struct sock *sk = sock->sk;
1608 struct sock *other = NULL;
1609 int err, size;
1610 struct sk_buff *skb;
1611 int sent = 0;
1612 struct scm_cookie tmp_scm;
1613 bool fds_sent = false;
1614 int max_level;
1615
1616 if (NULL == siocb->scm)
1617 siocb->scm = &tmp_scm;
1618 wait_for_unix_gc();
1619 err = scm_send(sock, msg, siocb->scm);
1620 if (err < 0)
1621 return err;
1622
1623 err = -EOPNOTSUPP;
1624 if (msg->msg_flags&MSG_OOB)
1625 goto out_err;
1626
1627 if (msg->msg_namelen) {
1628 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1629 goto out_err;
1630 } else {
1631 err = -ENOTCONN;
1632 other = unix_peer(sk);
1633 if (!other)
1634 goto out_err;
1635 }
1636
1637 if (sk->sk_shutdown & SEND_SHUTDOWN)
1638 goto pipe_err;
1639
1640 while (sent < len) {
1641 /*
1642 * Optimisation for the fact that under 0.01% of X
1643 * messages typically need breaking up.
1644 */
1645
1646 size = len-sent;
1647
1648 /* Keep two messages in the pipe so it schedules better */
1649 if (size > ((sk->sk_sndbuf >> 1) - 64))
1650 size = (sk->sk_sndbuf >> 1) - 64;
1651
1652 if (size > SKB_MAX_ALLOC)
1653 size = SKB_MAX_ALLOC;
1654
1655 /*
1656 * Grab a buffer
1657 */
1658
1659 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT,
1660 &err);
1661
1662 if (skb == NULL)
1663 goto out_err;
1664
1665 /*
1666 * If you pass two values to the sock_alloc_send_skb
1667 * it tries to grab the large buffer with GFP_NOFS
1668 * (which can fail easily), and if it fails grab the
1669 * fallback size buffer which is under a page and will
1670 * succeed. [Alan]
1671 */
1672 size = min_t(int, size, skb_tailroom(skb));
1673
1674
1675 /* Only send the fds in the first buffer */
1676 err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
1677 if (err < 0) {
1678 kfree_skb(skb);
1679 goto out_err;
1680 }
1681 max_level = err + 1;
1682 fds_sent = true;
1683
1684 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
1685 if (err) {
1686 kfree_skb(skb);
1687 goto out_err;
1688 }
1689
1690 unix_state_lock(other);
1691
1692 if (sock_flag(other, SOCK_DEAD) ||
1693 (other->sk_shutdown & RCV_SHUTDOWN))
1694 goto pipe_err_free;
1695
1696 maybe_add_creds(skb, sock, other);
1697 skb_queue_tail(&other->sk_receive_queue, skb);
1698 if (max_level > unix_sk(other)->recursion_level)
1699 unix_sk(other)->recursion_level = max_level;
1700 unix_state_unlock(other);
1701 other->sk_data_ready(other, size);
1702 sent += size;
1703 }
1704
1705 scm_destroy(siocb->scm);
1706 siocb->scm = NULL;
1707
1708 return sent;
1709
1710pipe_err_free:
1711 unix_state_unlock(other);
1712 kfree_skb(skb);
1713pipe_err:
1714 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1715 send_sig(SIGPIPE, current, 0);
1716 err = -EPIPE;
1717out_err:
1718 scm_destroy(siocb->scm);
1719 siocb->scm = NULL;
1720 return sent ? : err;
1721}
1722
1723static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1724 struct msghdr *msg, size_t len)
1725{
1726 int err;
1727 struct sock *sk = sock->sk;
1728
1729 err = sock_error(sk);
1730 if (err)
1731 return err;
1732
1733 if (sk->sk_state != TCP_ESTABLISHED)
1734 return -ENOTCONN;
1735
1736 if (msg->msg_namelen)
1737 msg->msg_namelen = 0;
1738
1739 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1740}
1741
1742static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock,
1743 struct msghdr *msg, size_t size,
1744 int flags)
1745{
1746 struct sock *sk = sock->sk;
1747
1748 if (sk->sk_state != TCP_ESTABLISHED)
1749 return -ENOTCONN;
1750
1751 return unix_dgram_recvmsg(iocb, sock, msg, size, flags);
1752}
1753
1754static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1755{
1756 struct unix_sock *u = unix_sk(sk);
1757
1758 msg->msg_namelen = 0;
1759 if (u->addr) {
1760 msg->msg_namelen = u->addr->len;
1761 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1762 }
1763}
1764
1765static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1766 struct msghdr *msg, size_t size,
1767 int flags)
1768{
1769 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1770 struct scm_cookie tmp_scm;
1771 struct sock *sk = sock->sk;
1772 struct unix_sock *u = unix_sk(sk);
1773 int noblock = flags & MSG_DONTWAIT;
1774 struct sk_buff *skb;
1775 int err;
1776 int peeked, skip;
1777
1778 err = -EOPNOTSUPP;
1779 if (flags&MSG_OOB)
1780 goto out;
1781
1782 msg->msg_namelen = 0;
1783
1784 err = mutex_lock_interruptible(&u->readlock);
1785 if (err) {
1786 err = sock_intr_errno(sock_rcvtimeo(sk, noblock));
1787 goto out;
1788 }
1789
1790 skip = sk_peek_offset(sk, flags);
1791
1792 skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err);
1793 if (!skb) {
1794 unix_state_lock(sk);
1795 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1796 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1797 (sk->sk_shutdown & RCV_SHUTDOWN))
1798 err = 0;
1799 unix_state_unlock(sk);
1800 goto out_unlock;
1801 }
1802
1803 wake_up_interruptible_sync_poll(&u->peer_wait,
1804 POLLOUT | POLLWRNORM | POLLWRBAND);
1805
1806 if (msg->msg_name)
1807 unix_copy_addr(msg, skb->sk);
1808
1809 if (size > skb->len - skip)
1810 size = skb->len - skip;
1811 else if (size < skb->len - skip)
1812 msg->msg_flags |= MSG_TRUNC;
1813
1814 err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size);
1815 if (err)
1816 goto out_free;
1817
1818 if (sock_flag(sk, SOCK_RCVTSTAMP))
1819 __sock_recv_timestamp(msg, sk, skb);
1820
1821 if (!siocb->scm) {
1822 siocb->scm = &tmp_scm;
1823 memset(&tmp_scm, 0, sizeof(tmp_scm));
1824 }
1825 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
1826 unix_set_secdata(siocb->scm, skb);
1827
1828 if (!(flags & MSG_PEEK)) {
1829 if (UNIXCB(skb).fp)
1830 unix_detach_fds(siocb->scm, skb);
1831
1832 sk_peek_offset_bwd(sk, skb->len);
1833 } else {
1834 /* It is questionable: on PEEK we could:
1835 - do not return fds - good, but too simple 8)
1836 - return fds, and do not return them on read (old strategy,
1837 apparently wrong)
1838 - clone fds (I chose it for now, it is the most universal
1839 solution)
1840
1841 POSIX 1003.1g does not actually define this clearly
1842 at all. POSIX 1003.1g doesn't define a lot of things
1843 clearly however!
1844
1845 */
1846
1847 sk_peek_offset_fwd(sk, size);
1848
1849 if (UNIXCB(skb).fp)
1850 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1851 }
1852 err = (flags & MSG_TRUNC) ? skb->len - skip : size;
1853
1854 scm_recv(sock, msg, siocb->scm, flags);
1855
1856out_free:
1857 skb_free_datagram(sk, skb);
1858out_unlock:
1859 mutex_unlock(&u->readlock);
1860out:
1861 return err;
1862}
1863
1864/*
1865 * Sleep until data has arrive. But check for races..
1866 */
1867
1868static long unix_stream_data_wait(struct sock *sk, long timeo)
1869{
1870 DEFINE_WAIT(wait);
1871
1872 unix_state_lock(sk);
1873
1874 for (;;) {
1875 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1876
1877 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1878 sk->sk_err ||
1879 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1880 signal_pending(current) ||
1881 !timeo)
1882 break;
1883
1884 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1885 unix_state_unlock(sk);
1886 timeo = schedule_timeout(timeo);
1887 unix_state_lock(sk);
1888 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1889 }
1890
1891 finish_wait(sk_sleep(sk), &wait);
1892 unix_state_unlock(sk);
1893 return timeo;
1894}
1895
1896
1897
1898static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1899 struct msghdr *msg, size_t size,
1900 int flags)
1901{
1902 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1903 struct scm_cookie tmp_scm;
1904 struct sock *sk = sock->sk;
1905 struct unix_sock *u = unix_sk(sk);
1906 struct sockaddr_un *sunaddr = msg->msg_name;
1907 int copied = 0;
1908 int check_creds = 0;
1909 int target;
1910 int err = 0;
1911 long timeo;
1912 int skip;
1913
1914 err = -EINVAL;
1915 if (sk->sk_state != TCP_ESTABLISHED)
1916 goto out;
1917
1918 err = -EOPNOTSUPP;
1919 if (flags&MSG_OOB)
1920 goto out;
1921
1922 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1923 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1924
1925 msg->msg_namelen = 0;
1926
1927 /* Lock the socket to prevent queue disordering
1928 * while sleeps in memcpy_tomsg
1929 */
1930
1931 if (!siocb->scm) {
1932 siocb->scm = &tmp_scm;
1933 memset(&tmp_scm, 0, sizeof(tmp_scm));
1934 }
1935
1936 err = mutex_lock_interruptible(&u->readlock);
1937 if (err) {
1938 err = sock_intr_errno(timeo);
1939 goto out;
1940 }
1941
1942 skip = sk_peek_offset(sk, flags);
1943
1944 do {
1945 int chunk;
1946 struct sk_buff *skb;
1947
1948 unix_state_lock(sk);
1949 skb = skb_peek(&sk->sk_receive_queue);
1950again:
1951 if (skb == NULL) {
1952 unix_sk(sk)->recursion_level = 0;
1953 if (copied >= target)
1954 goto unlock;
1955
1956 /*
1957 * POSIX 1003.1g mandates this order.
1958 */
1959
1960 err = sock_error(sk);
1961 if (err)
1962 goto unlock;
1963 if (sk->sk_shutdown & RCV_SHUTDOWN)
1964 goto unlock;
1965
1966 unix_state_unlock(sk);
1967 err = -EAGAIN;
1968 if (!timeo)
1969 break;
1970 mutex_unlock(&u->readlock);
1971
1972 timeo = unix_stream_data_wait(sk, timeo);
1973
1974 if (signal_pending(current)
1975 || mutex_lock_interruptible(&u->readlock)) {
1976 err = sock_intr_errno(timeo);
1977 goto out;
1978 }
1979
1980 continue;
1981 unlock:
1982 unix_state_unlock(sk);
1983 break;
1984 }
1985
1986 if (skip >= skb->len) {
1987 skip -= skb->len;
1988 skb = skb_peek_next(skb, &sk->sk_receive_queue);
1989 goto again;
1990 }
1991
1992 unix_state_unlock(sk);
1993
1994 if (check_creds) {
1995 /* Never glue messages from different writers */
1996 if ((UNIXCB(skb).pid != siocb->scm->pid) ||
1997 (UNIXCB(skb).cred != siocb->scm->cred))
1998 break;
1999 } else {
2000 /* Copy credentials */
2001 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
2002 check_creds = 1;
2003 }
2004
2005 /* Copy address just once */
2006 if (sunaddr) {
2007 unix_copy_addr(msg, skb->sk);
2008 sunaddr = NULL;
2009 }
2010
2011 chunk = min_t(unsigned int, skb->len - skip, size);
2012 if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) {
2013 if (copied == 0)
2014 copied = -EFAULT;
2015 break;
2016 }
2017 copied += chunk;
2018 size -= chunk;
2019
2020 /* Mark read part of skb as used */
2021 if (!(flags & MSG_PEEK)) {
2022 skb_pull(skb, chunk);
2023
2024 sk_peek_offset_bwd(sk, chunk);
2025
2026 if (UNIXCB(skb).fp)
2027 unix_detach_fds(siocb->scm, skb);
2028
2029 if (skb->len)
2030 break;
2031
2032 skb_unlink(skb, &sk->sk_receive_queue);
2033 consume_skb(skb);
2034
2035 if (siocb->scm->fp)
2036 break;
2037 } else {
2038 /* It is questionable, see note in unix_dgram_recvmsg.
2039 */
2040 if (UNIXCB(skb).fp)
2041 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
2042
2043 sk_peek_offset_fwd(sk, chunk);
2044
2045 break;
2046 }
2047 } while (size);
2048
2049 mutex_unlock(&u->readlock);
2050 scm_recv(sock, msg, siocb->scm, flags);
2051out:
2052 return copied ? : err;
2053}
2054
2055static int unix_shutdown(struct socket *sock, int mode)
2056{
2057 struct sock *sk = sock->sk;
2058 struct sock *other;
2059
2060 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
2061
2062 if (!mode)
2063 return 0;
2064
2065 unix_state_lock(sk);
2066 sk->sk_shutdown |= mode;
2067 other = unix_peer(sk);
2068 if (other)
2069 sock_hold(other);
2070 unix_state_unlock(sk);
2071 sk->sk_state_change(sk);
2072
2073 if (other &&
2074 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
2075
2076 int peer_mode = 0;
2077
2078 if (mode&RCV_SHUTDOWN)
2079 peer_mode |= SEND_SHUTDOWN;
2080 if (mode&SEND_SHUTDOWN)
2081 peer_mode |= RCV_SHUTDOWN;
2082 unix_state_lock(other);
2083 other->sk_shutdown |= peer_mode;
2084 unix_state_unlock(other);
2085 other->sk_state_change(other);
2086 if (peer_mode == SHUTDOWN_MASK)
2087 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
2088 else if (peer_mode & RCV_SHUTDOWN)
2089 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
2090 }
2091 if (other)
2092 sock_put(other);
2093
2094 return 0;
2095}
2096
2097long unix_inq_len(struct sock *sk)
2098{
2099 struct sk_buff *skb;
2100 long amount = 0;
2101
2102 if (sk->sk_state == TCP_LISTEN)
2103 return -EINVAL;
2104
2105 spin_lock(&sk->sk_receive_queue.lock);
2106 if (sk->sk_type == SOCK_STREAM ||
2107 sk->sk_type == SOCK_SEQPACKET) {
2108 skb_queue_walk(&sk->sk_receive_queue, skb)
2109 amount += skb->len;
2110 } else {
2111 skb = skb_peek(&sk->sk_receive_queue);
2112 if (skb)
2113 amount = skb->len;
2114 }
2115 spin_unlock(&sk->sk_receive_queue.lock);
2116
2117 return amount;
2118}
2119EXPORT_SYMBOL_GPL(unix_inq_len);
2120
2121long unix_outq_len(struct sock *sk)
2122{
2123 return sk_wmem_alloc_get(sk);
2124}
2125EXPORT_SYMBOL_GPL(unix_outq_len);
2126
2127static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2128{
2129 struct sock *sk = sock->sk;
2130 long amount = 0;
2131 int err;
2132
2133 switch (cmd) {
2134 case SIOCOUTQ:
2135 amount = unix_outq_len(sk);
2136 err = put_user(amount, (int __user *)arg);
2137 break;
2138 case SIOCINQ:
2139 amount = unix_inq_len(sk);
2140 if (amount < 0)
2141 err = amount;
2142 else
2143 err = put_user(amount, (int __user *)arg);
2144 break;
2145 default:
2146 err = -ENOIOCTLCMD;
2147 break;
2148 }
2149 return err;
2150}
2151
2152static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait)
2153{
2154 struct sock *sk = sock->sk;
2155 unsigned int mask;
2156
2157 sock_poll_wait(file, sk_sleep(sk), wait);
2158 mask = 0;
2159
2160 /* exceptional events? */
2161 if (sk->sk_err)
2162 mask |= POLLERR;
2163 if (sk->sk_shutdown == SHUTDOWN_MASK)
2164 mask |= POLLHUP;
2165 if (sk->sk_shutdown & RCV_SHUTDOWN)
2166 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2167
2168 /* readable? */
2169 if (!skb_queue_empty(&sk->sk_receive_queue))
2170 mask |= POLLIN | POLLRDNORM;
2171
2172 /* Connection-based need to check for termination and startup */
2173 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2174 sk->sk_state == TCP_CLOSE)
2175 mask |= POLLHUP;
2176
2177 /*
2178 * we set writable also when the other side has shut down the
2179 * connection. This prevents stuck sockets.
2180 */
2181 if (unix_writable(sk))
2182 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2183
2184 return mask;
2185}
2186
2187static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2188 poll_table *wait)
2189{
2190 struct sock *sk = sock->sk, *other;
2191 unsigned int mask, writable;
2192
2193 sock_poll_wait(file, sk_sleep(sk), wait);
2194 mask = 0;
2195
2196 /* exceptional events? */
2197 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2198 mask |= POLLERR;
2199 if (sk->sk_shutdown & RCV_SHUTDOWN)
2200 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2201 if (sk->sk_shutdown == SHUTDOWN_MASK)
2202 mask |= POLLHUP;
2203
2204 /* readable? */
2205 if (!skb_queue_empty(&sk->sk_receive_queue))
2206 mask |= POLLIN | POLLRDNORM;
2207
2208 /* Connection-based need to check for termination and startup */
2209 if (sk->sk_type == SOCK_SEQPACKET) {
2210 if (sk->sk_state == TCP_CLOSE)
2211 mask |= POLLHUP;
2212 /* connection hasn't started yet? */
2213 if (sk->sk_state == TCP_SYN_SENT)
2214 return mask;
2215 }
2216
2217 /* No write status requested, avoid expensive OUT tests. */
2218 if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT)))
2219 return mask;
2220
2221 writable = unix_writable(sk);
2222 other = unix_peer_get(sk);
2223 if (other) {
2224 if (unix_peer(other) != sk) {
2225 sock_poll_wait(file, &unix_sk(other)->peer_wait, wait);
2226 if (unix_recvq_full(other))
2227 writable = 0;
2228 }
2229 sock_put(other);
2230 }
2231
2232 if (writable)
2233 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2234 else
2235 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2236
2237 return mask;
2238}
2239
2240#ifdef CONFIG_PROC_FS
2241static struct sock *first_unix_socket(int *i)
2242{
2243 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
2244 if (!hlist_empty(&unix_socket_table[*i]))
2245 return __sk_head(&unix_socket_table[*i]);
2246 }
2247 return NULL;
2248}
2249
2250static struct sock *next_unix_socket(int *i, struct sock *s)
2251{
2252 struct sock *next = sk_next(s);
2253 /* More in this chain? */
2254 if (next)
2255 return next;
2256 /* Look for next non-empty chain. */
2257 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
2258 if (!hlist_empty(&unix_socket_table[*i]))
2259 return __sk_head(&unix_socket_table[*i]);
2260 }
2261 return NULL;
2262}
2263
2264struct unix_iter_state {
2265 struct seq_net_private p;
2266 int i;
2267};
2268
2269static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
2270{
2271 struct unix_iter_state *iter = seq->private;
2272 loff_t off = 0;
2273 struct sock *s;
2274
2275 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
2276 if (sock_net(s) != seq_file_net(seq))
2277 continue;
2278 if (off == pos)
2279 return s;
2280 ++off;
2281 }
2282 return NULL;
2283}
2284
2285static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2286 __acquires(unix_table_lock)
2287{
2288 spin_lock(&unix_table_lock);
2289 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2290}
2291
2292static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2293{
2294 struct unix_iter_state *iter = seq->private;
2295 struct sock *sk = v;
2296 ++*pos;
2297
2298 if (v == SEQ_START_TOKEN)
2299 sk = first_unix_socket(&iter->i);
2300 else
2301 sk = next_unix_socket(&iter->i, sk);
2302 while (sk && (sock_net(sk) != seq_file_net(seq)))
2303 sk = next_unix_socket(&iter->i, sk);
2304 return sk;
2305}
2306
2307static void unix_seq_stop(struct seq_file *seq, void *v)
2308 __releases(unix_table_lock)
2309{
2310 spin_unlock(&unix_table_lock);
2311}
2312
2313static int unix_seq_show(struct seq_file *seq, void *v)
2314{
2315
2316 if (v == SEQ_START_TOKEN)
2317 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2318 "Inode Path\n");
2319 else {
2320 struct sock *s = v;
2321 struct unix_sock *u = unix_sk(s);
2322 unix_state_lock(s);
2323
2324 seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu",
2325 s,
2326 atomic_read(&s->sk_refcnt),
2327 0,
2328 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2329 s->sk_type,
2330 s->sk_socket ?
2331 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2332 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2333 sock_i_ino(s));
2334
2335 if (u->addr) {
2336 int i, len;
2337 seq_putc(seq, ' ');
2338
2339 i = 0;
2340 len = u->addr->len - sizeof(short);
2341 if (!UNIX_ABSTRACT(s))
2342 len--;
2343 else {
2344 seq_putc(seq, '@');
2345 i++;
2346 }
2347 for ( ; i < len; i++)
2348 seq_putc(seq, u->addr->name->sun_path[i]);
2349 }
2350 unix_state_unlock(s);
2351 seq_putc(seq, '\n');
2352 }
2353
2354 return 0;
2355}
2356
2357static const struct seq_operations unix_seq_ops = {
2358 .start = unix_seq_start,
2359 .next = unix_seq_next,
2360 .stop = unix_seq_stop,
2361 .show = unix_seq_show,
2362};
2363
2364static int unix_seq_open(struct inode *inode, struct file *file)
2365{
2366 return seq_open_net(inode, file, &unix_seq_ops,
2367 sizeof(struct unix_iter_state));
2368}
2369
2370static const struct file_operations unix_seq_fops = {
2371 .owner = THIS_MODULE,
2372 .open = unix_seq_open,
2373 .read = seq_read,
2374 .llseek = seq_lseek,
2375 .release = seq_release_net,
2376};
2377
2378#endif
2379
2380static const struct net_proto_family unix_family_ops = {
2381 .family = PF_UNIX,
2382 .create = unix_create,
2383 .owner = THIS_MODULE,
2384};
2385
2386
2387static int __net_init unix_net_init(struct net *net)
2388{
2389 int error = -ENOMEM;
2390
2391 net->unx.sysctl_max_dgram_qlen = 10;
2392 if (unix_sysctl_register(net))
2393 goto out;
2394
2395#ifdef CONFIG_PROC_FS
2396 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2397 unix_sysctl_unregister(net);
2398 goto out;
2399 }
2400#endif
2401 error = 0;
2402out:
2403 return error;
2404}
2405
2406static void __net_exit unix_net_exit(struct net *net)
2407{
2408 unix_sysctl_unregister(net);
2409 proc_net_remove(net, "unix");
2410}
2411
2412static struct pernet_operations unix_net_ops = {
2413 .init = unix_net_init,
2414 .exit = unix_net_exit,
2415};
2416
2417static int __init af_unix_init(void)
2418{
2419 int rc = -1;
2420 struct sk_buff *dummy_skb;
2421
2422 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2423
2424 rc = proto_register(&unix_proto, 1);
2425 if (rc != 0) {
2426 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2427 __func__);
2428 goto out;
2429 }
2430
2431 sock_register(&unix_family_ops);
2432 register_pernet_subsys(&unix_net_ops);
2433out:
2434 return rc;
2435}
2436
2437static void __exit af_unix_exit(void)
2438{
2439 sock_unregister(PF_UNIX);
2440 proto_unregister(&unix_proto);
2441 unregister_pernet_subsys(&unix_net_ops);
2442}
2443
2444/* Earlier than device_initcall() so that other drivers invoking
2445 request_module() don't end up in a loop when modprobe tries
2446 to use a UNIX socket. But later than subsys_initcall() because
2447 we depend on stuff initialised there */
2448fs_initcall(af_unix_init);
2449module_exit(af_unix_exit);
2450
2451MODULE_LICENSE("GPL");
2452MODULE_ALIAS_NETPROTO(PF_UNIX);
Linux kernel - Deliverables
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