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[mirror_ubuntu-bionic-kernel.git] / net / unix / af_unix.c
1 /*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
4 * Authors: Alan Cox, <alan.cox@linux.org>
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 * Version: $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $
12 *
13 * Fixes:
14 * Linus Torvalds : Assorted bug cures.
15 * Niibe Yutaka : async I/O support.
16 * Carsten Paeth : PF_UNIX check, address fixes.
17 * Alan Cox : Limit size of allocated blocks.
18 * Alan Cox : Fixed the stupid socketpair bug.
19 * Alan Cox : BSD compatibility fine tuning.
20 * Alan Cox : Fixed a bug in connect when interrupted.
21 * Alan Cox : Sorted out a proper draft version of
22 * file descriptor passing hacked up from
23 * Mike Shaver's work.
24 * Marty Leisner : Fixes to fd passing
25 * Nick Nevin : recvmsg bugfix.
26 * Alan Cox : Started proper garbage collector
27 * Heiko EiBfeldt : Missing verify_area check
28 * Alan Cox : Started POSIXisms
29 * Andreas Schwab : Replace inode by dentry for proper
30 * reference counting
31 * Kirk Petersen : Made this a module
32 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
33 * Lots of bug fixes.
34 * Alexey Kuznetosv : Repaired (I hope) bugs introduces
35 * by above two patches.
36 * Andrea Arcangeli : If possible we block in connect(2)
37 * if the max backlog of the listen socket
38 * is been reached. This won't break
39 * old apps and it will avoid huge amount
40 * of socks hashed (this for unix_gc()
41 * performances reasons).
42 * Security fix that limits the max
43 * number of socks to 2*max_files and
44 * the number of skb queueable in the
45 * dgram receiver.
46 * Artur Skawina : Hash function optimizations
47 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
48 * Malcolm Beattie : Set peercred for socketpair
49 * Michal Ostrowski : Module initialization cleanup.
50 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
51 * the core infrastructure is doing that
52 * for all net proto families now (2.5.69+)
53 *
54 *
55 * Known differences from reference BSD that was tested:
56 *
57 * [TO FIX]
58 * ECONNREFUSED is not returned from one end of a connected() socket to the
59 * other the moment one end closes.
60 * fstat() doesn't return st_dev=0, and give the blksize as high water mark
61 * and a fake inode identifier (nor the BSD first socket fstat twice bug).
62 * [NOT TO FIX]
63 * accept() returns a path name even if the connecting socket has closed
64 * in the meantime (BSD loses the path and gives up).
65 * accept() returns 0 length path for an unbound connector. BSD returns 16
66 * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
67 * socketpair(...SOCK_RAW..) doesn't panic the kernel.
68 * BSD af_unix apparently has connect forgetting to block properly.
69 * (need to check this with the POSIX spec in detail)
70 *
71 * Differences from 2.0.0-11-... (ANK)
72 * Bug fixes and improvements.
73 * - client shutdown killed server socket.
74 * - removed all useless cli/sti pairs.
75 *
76 * Semantic changes/extensions.
77 * - generic control message passing.
78 * - SCM_CREDENTIALS control message.
79 * - "Abstract" (not FS based) socket bindings.
80 * Abstract names are sequences of bytes (not zero terminated)
81 * started by 0, so that this name space does not intersect
82 * with BSD names.
83 */
84
85 #include <linux/module.h>
86 #include <linux/kernel.h>
87 #include <linux/signal.h>
88 #include <linux/sched.h>
89 #include <linux/errno.h>
90 #include <linux/string.h>
91 #include <linux/stat.h>
92 #include <linux/dcache.h>
93 #include <linux/namei.h>
94 #include <linux/socket.h>
95 #include <linux/un.h>
96 #include <linux/fcntl.h>
97 #include <linux/termios.h>
98 #include <linux/sockios.h>
99 #include <linux/net.h>
100 #include <linux/in.h>
101 #include <linux/fs.h>
102 #include <linux/slab.h>
103 #include <asm/uaccess.h>
104 #include <linux/skbuff.h>
105 #include <linux/netdevice.h>
106 #include <net/net_namespace.h>
107 #include <net/sock.h>
108 #include <net/tcp_states.h>
109 #include <net/af_unix.h>
110 #include <linux/proc_fs.h>
111 #include <linux/seq_file.h>
112 #include <net/scm.h>
113 #include <linux/init.h>
114 #include <linux/poll.h>
115 #include <linux/rtnetlink.h>
116 #include <linux/mount.h>
117 #include <net/checksum.h>
118 #include <linux/security.h>
119
120 static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
121 static DEFINE_SPINLOCK(unix_table_lock);
122 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
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
129 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
130 {
131 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
132 }
133
134 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
135 {
136 scm->secid = *UNIXSID(skb);
137 }
138 #else
139 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
140 { }
141
142 static 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 rwlock.
150 */
151
152 static 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
162 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
163 {
164 return unix_peer(osk) == sk;
165 }
166
167 static 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
172 static 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
177 static struct 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 }
188
189 static inline void unix_release_addr(struct unix_address *addr)
190 {
191 if (atomic_dec_and_test(&addr->refcnt))
192 kfree(addr);
193 }
194
195 /*
196 * Check unix socket name:
197 * - should be not zero length.
198 * - if started by not zero, should be NULL terminated (FS object)
199 * - if started by zero, it is abstract name.
200 */
201
202 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
203 {
204 if (len <= sizeof(short) || len > sizeof(*sunaddr))
205 return -EINVAL;
206 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
207 return -EINVAL;
208 if (sunaddr->sun_path[0]) {
209 /*
210 * This may look like an off by one error but it is a bit more
211 * subtle. 108 is the longest valid AF_UNIX path for a binding.
212 * sun_path[108] doesnt as such exist. However in kernel space
213 * we are guaranteed that it is a valid memory location in our
214 * kernel address buffer.
215 */
216 ((char *)sunaddr)[len]=0;
217 len = strlen(sunaddr->sun_path)+1+sizeof(short);
218 return len;
219 }
220
221 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
222 return len;
223 }
224
225 static void __unix_remove_socket(struct sock *sk)
226 {
227 sk_del_node_init(sk);
228 }
229
230 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
231 {
232 BUG_TRAP(sk_unhashed(sk));
233 sk_add_node(sk, list);
234 }
235
236 static inline void unix_remove_socket(struct sock *sk)
237 {
238 spin_lock(&unix_table_lock);
239 __unix_remove_socket(sk);
240 spin_unlock(&unix_table_lock);
241 }
242
243 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
244 {
245 spin_lock(&unix_table_lock);
246 __unix_insert_socket(list, sk);
247 spin_unlock(&unix_table_lock);
248 }
249
250 static struct sock *__unix_find_socket_byname(struct net *net,
251 struct sockaddr_un *sunname,
252 int len, int type, unsigned hash)
253 {
254 struct sock *s;
255 struct hlist_node *node;
256
257 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
258 struct unix_sock *u = unix_sk(s);
259
260 if (!net_eq(sock_net(s), net))
261 continue;
262
263 if (u->addr->len == len &&
264 !memcmp(u->addr->name, sunname, len))
265 goto found;
266 }
267 s = NULL;
268 found:
269 return s;
270 }
271
272 static inline struct sock *unix_find_socket_byname(struct net *net,
273 struct sockaddr_un *sunname,
274 int len, int type,
275 unsigned hash)
276 {
277 struct sock *s;
278
279 spin_lock(&unix_table_lock);
280 s = __unix_find_socket_byname(net, sunname, len, type, hash);
281 if (s)
282 sock_hold(s);
283 spin_unlock(&unix_table_lock);
284 return s;
285 }
286
287 static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
288 {
289 struct sock *s;
290 struct hlist_node *node;
291
292 spin_lock(&unix_table_lock);
293 sk_for_each(s, node,
294 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
295 struct dentry *dentry = unix_sk(s)->dentry;
296
297 if (!net_eq(sock_net(s), net))
298 continue;
299
300 if(dentry && dentry->d_inode == i)
301 {
302 sock_hold(s);
303 goto found;
304 }
305 }
306 s = NULL;
307 found:
308 spin_unlock(&unix_table_lock);
309 return s;
310 }
311
312 static inline int unix_writable(struct sock *sk)
313 {
314 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
315 }
316
317 static void unix_write_space(struct sock *sk)
318 {
319 read_lock(&sk->sk_callback_lock);
320 if (unix_writable(sk)) {
321 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
322 wake_up_interruptible_sync(sk->sk_sleep);
323 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
324 }
325 read_unlock(&sk->sk_callback_lock);
326 }
327
328 /* When dgram socket disconnects (or changes its peer), we clear its receive
329 * queue of packets arrived from previous peer. First, it allows to do
330 * flow control based only on wmem_alloc; second, sk connected to peer
331 * may receive messages only from that peer. */
332 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
333 {
334 if (!skb_queue_empty(&sk->sk_receive_queue)) {
335 skb_queue_purge(&sk->sk_receive_queue);
336 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
337
338 /* If one link of bidirectional dgram pipe is disconnected,
339 * we signal error. Messages are lost. Do not make this,
340 * when peer was not connected to us.
341 */
342 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
343 other->sk_err = ECONNRESET;
344 other->sk_error_report(other);
345 }
346 }
347 }
348
349 static void unix_sock_destructor(struct sock *sk)
350 {
351 struct unix_sock *u = unix_sk(sk);
352
353 skb_queue_purge(&sk->sk_receive_queue);
354
355 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
356 BUG_TRAP(sk_unhashed(sk));
357 BUG_TRAP(!sk->sk_socket);
358 if (!sock_flag(sk, SOCK_DEAD)) {
359 printk("Attempt to release alive unix socket: %p\n", sk);
360 return;
361 }
362
363 if (u->addr)
364 unix_release_addr(u->addr);
365
366 atomic_dec(&unix_nr_socks);
367 #ifdef UNIX_REFCNT_DEBUG
368 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
369 #endif
370 }
371
372 static int unix_release_sock (struct sock *sk, int embrion)
373 {
374 struct unix_sock *u = unix_sk(sk);
375 struct dentry *dentry;
376 struct vfsmount *mnt;
377 struct sock *skpair;
378 struct sk_buff *skb;
379 int state;
380
381 unix_remove_socket(sk);
382
383 /* Clear state */
384 unix_state_lock(sk);
385 sock_orphan(sk);
386 sk->sk_shutdown = SHUTDOWN_MASK;
387 dentry = u->dentry;
388 u->dentry = NULL;
389 mnt = u->mnt;
390 u->mnt = NULL;
391 state = sk->sk_state;
392 sk->sk_state = TCP_CLOSE;
393 unix_state_unlock(sk);
394
395 wake_up_interruptible_all(&u->peer_wait);
396
397 skpair=unix_peer(sk);
398
399 if (skpair!=NULL) {
400 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
401 unix_state_lock(skpair);
402 /* No more writes */
403 skpair->sk_shutdown = SHUTDOWN_MASK;
404 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
405 skpair->sk_err = ECONNRESET;
406 unix_state_unlock(skpair);
407 skpair->sk_state_change(skpair);
408 read_lock(&skpair->sk_callback_lock);
409 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
410 read_unlock(&skpair->sk_callback_lock);
411 }
412 sock_put(skpair); /* It may now die */
413 unix_peer(sk) = NULL;
414 }
415
416 /* Try to flush out this socket. Throw out buffers at least */
417
418 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
419 if (state==TCP_LISTEN)
420 unix_release_sock(skb->sk, 1);
421 /* passed fds are erased in the kfree_skb hook */
422 kfree_skb(skb);
423 }
424
425 if (dentry) {
426 dput(dentry);
427 mntput(mnt);
428 }
429
430 sock_put(sk);
431
432 /* ---- Socket is dead now and most probably destroyed ---- */
433
434 /*
435 * Fixme: BSD difference: In BSD all sockets connected to use get
436 * ECONNRESET and we die on the spot. In Linux we behave
437 * like files and pipes do and wait for the last
438 * dereference.
439 *
440 * Can't we simply set sock->err?
441 *
442 * What the above comment does talk about? --ANK(980817)
443 */
444
445 if (unix_tot_inflight)
446 unix_gc(); /* Garbage collect fds */
447
448 return 0;
449 }
450
451 static int unix_listen(struct socket *sock, int backlog)
452 {
453 int err;
454 struct sock *sk = sock->sk;
455 struct unix_sock *u = unix_sk(sk);
456
457 err = -EOPNOTSUPP;
458 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
459 goto out; /* Only stream/seqpacket sockets accept */
460 err = -EINVAL;
461 if (!u->addr)
462 goto out; /* No listens on an unbound socket */
463 unix_state_lock(sk);
464 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
465 goto out_unlock;
466 if (backlog > sk->sk_max_ack_backlog)
467 wake_up_interruptible_all(&u->peer_wait);
468 sk->sk_max_ack_backlog = backlog;
469 sk->sk_state = TCP_LISTEN;
470 /* set credentials so connect can copy them */
471 sk->sk_peercred.pid = task_tgid_vnr(current);
472 sk->sk_peercred.uid = current->euid;
473 sk->sk_peercred.gid = current->egid;
474 err = 0;
475
476 out_unlock:
477 unix_state_unlock(sk);
478 out:
479 return err;
480 }
481
482 static int unix_release(struct socket *);
483 static int unix_bind(struct socket *, struct sockaddr *, int);
484 static int unix_stream_connect(struct socket *, struct sockaddr *,
485 int addr_len, int flags);
486 static int unix_socketpair(struct socket *, struct socket *);
487 static int unix_accept(struct socket *, struct socket *, int);
488 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
489 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
490 static unsigned int unix_dgram_poll(struct file *, struct socket *,
491 poll_table *);
492 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
493 static int unix_shutdown(struct socket *, int);
494 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
495 struct msghdr *, size_t);
496 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
497 struct msghdr *, size_t, int);
498 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
499 struct msghdr *, size_t);
500 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
501 struct msghdr *, size_t, int);
502 static int unix_dgram_connect(struct socket *, struct sockaddr *,
503 int, int);
504 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
505 struct msghdr *, size_t);
506
507 static const struct proto_ops unix_stream_ops = {
508 .family = PF_UNIX,
509 .owner = THIS_MODULE,
510 .release = unix_release,
511 .bind = unix_bind,
512 .connect = unix_stream_connect,
513 .socketpair = unix_socketpair,
514 .accept = unix_accept,
515 .getname = unix_getname,
516 .poll = unix_poll,
517 .ioctl = unix_ioctl,
518 .listen = unix_listen,
519 .shutdown = unix_shutdown,
520 .setsockopt = sock_no_setsockopt,
521 .getsockopt = sock_no_getsockopt,
522 .sendmsg = unix_stream_sendmsg,
523 .recvmsg = unix_stream_recvmsg,
524 .mmap = sock_no_mmap,
525 .sendpage = sock_no_sendpage,
526 };
527
528 static const struct proto_ops unix_dgram_ops = {
529 .family = PF_UNIX,
530 .owner = THIS_MODULE,
531 .release = unix_release,
532 .bind = unix_bind,
533 .connect = unix_dgram_connect,
534 .socketpair = unix_socketpair,
535 .accept = sock_no_accept,
536 .getname = unix_getname,
537 .poll = unix_dgram_poll,
538 .ioctl = unix_ioctl,
539 .listen = sock_no_listen,
540 .shutdown = unix_shutdown,
541 .setsockopt = sock_no_setsockopt,
542 .getsockopt = sock_no_getsockopt,
543 .sendmsg = unix_dgram_sendmsg,
544 .recvmsg = unix_dgram_recvmsg,
545 .mmap = sock_no_mmap,
546 .sendpage = sock_no_sendpage,
547 };
548
549 static const struct proto_ops unix_seqpacket_ops = {
550 .family = PF_UNIX,
551 .owner = THIS_MODULE,
552 .release = unix_release,
553 .bind = unix_bind,
554 .connect = unix_stream_connect,
555 .socketpair = unix_socketpair,
556 .accept = unix_accept,
557 .getname = unix_getname,
558 .poll = unix_dgram_poll,
559 .ioctl = unix_ioctl,
560 .listen = unix_listen,
561 .shutdown = unix_shutdown,
562 .setsockopt = sock_no_setsockopt,
563 .getsockopt = sock_no_getsockopt,
564 .sendmsg = unix_seqpacket_sendmsg,
565 .recvmsg = unix_dgram_recvmsg,
566 .mmap = sock_no_mmap,
567 .sendpage = sock_no_sendpage,
568 };
569
570 static struct proto unix_proto = {
571 .name = "UNIX",
572 .owner = THIS_MODULE,
573 .obj_size = sizeof(struct unix_sock),
574 };
575
576 /*
577 * AF_UNIX sockets do not interact with hardware, hence they
578 * dont trigger interrupts - so it's safe for them to have
579 * bh-unsafe locking for their sk_receive_queue.lock. Split off
580 * this special lock-class by reinitializing the spinlock key:
581 */
582 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
583
584 static struct sock * unix_create1(struct net *net, struct socket *sock)
585 {
586 struct sock *sk = NULL;
587 struct unix_sock *u;
588
589 atomic_inc(&unix_nr_socks);
590 if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
591 goto out;
592
593 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
594 if (!sk)
595 goto out;
596
597 sock_init_data(sock,sk);
598 lockdep_set_class(&sk->sk_receive_queue.lock,
599 &af_unix_sk_receive_queue_lock_key);
600
601 sk->sk_write_space = unix_write_space;
602 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
603 sk->sk_destruct = unix_sock_destructor;
604 u = unix_sk(sk);
605 u->dentry = NULL;
606 u->mnt = NULL;
607 spin_lock_init(&u->lock);
608 atomic_set(&u->inflight, 0);
609 INIT_LIST_HEAD(&u->link);
610 mutex_init(&u->readlock); /* single task reading lock */
611 init_waitqueue_head(&u->peer_wait);
612 unix_insert_socket(unix_sockets_unbound, sk);
613 out:
614 if (sk == NULL)
615 atomic_dec(&unix_nr_socks);
616 return sk;
617 }
618
619 static int unix_create(struct net *net, struct socket *sock, int protocol)
620 {
621 if (protocol && protocol != PF_UNIX)
622 return -EPROTONOSUPPORT;
623
624 sock->state = SS_UNCONNECTED;
625
626 switch (sock->type) {
627 case SOCK_STREAM:
628 sock->ops = &unix_stream_ops;
629 break;
630 /*
631 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
632 * nothing uses it.
633 */
634 case SOCK_RAW:
635 sock->type=SOCK_DGRAM;
636 case SOCK_DGRAM:
637 sock->ops = &unix_dgram_ops;
638 break;
639 case SOCK_SEQPACKET:
640 sock->ops = &unix_seqpacket_ops;
641 break;
642 default:
643 return -ESOCKTNOSUPPORT;
644 }
645
646 return unix_create1(net, sock) ? 0 : -ENOMEM;
647 }
648
649 static int unix_release(struct socket *sock)
650 {
651 struct sock *sk = sock->sk;
652
653 if (!sk)
654 return 0;
655
656 sock->sk = NULL;
657
658 return unix_release_sock (sk, 0);
659 }
660
661 static int unix_autobind(struct socket *sock)
662 {
663 struct sock *sk = sock->sk;
664 struct net *net = sock_net(sk);
665 struct unix_sock *u = unix_sk(sk);
666 static u32 ordernum = 1;
667 struct unix_address * addr;
668 int err;
669
670 mutex_lock(&u->readlock);
671
672 err = 0;
673 if (u->addr)
674 goto out;
675
676 err = -ENOMEM;
677 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
678 if (!addr)
679 goto out;
680
681 addr->name->sun_family = AF_UNIX;
682 atomic_set(&addr->refcnt, 1);
683
684 retry:
685 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
686 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
687
688 spin_lock(&unix_table_lock);
689 ordernum = (ordernum+1)&0xFFFFF;
690
691 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
692 addr->hash)) {
693 spin_unlock(&unix_table_lock);
694 /* Sanity yield. It is unusual case, but yet... */
695 if (!(ordernum&0xFF))
696 yield();
697 goto retry;
698 }
699 addr->hash ^= sk->sk_type;
700
701 __unix_remove_socket(sk);
702 u->addr = addr;
703 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
704 spin_unlock(&unix_table_lock);
705 err = 0;
706
707 out: mutex_unlock(&u->readlock);
708 return err;
709 }
710
711 static struct sock *unix_find_other(struct net *net,
712 struct sockaddr_un *sunname, int len,
713 int type, unsigned hash, int *error)
714 {
715 struct sock *u;
716 struct nameidata nd;
717 int err = 0;
718
719 if (sunname->sun_path[0]) {
720 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
721 if (err)
722 goto fail;
723 err = vfs_permission(&nd, MAY_WRITE);
724 if (err)
725 goto put_fail;
726
727 err = -ECONNREFUSED;
728 if (!S_ISSOCK(nd.path.dentry->d_inode->i_mode))
729 goto put_fail;
730 u = unix_find_socket_byinode(net, nd.path.dentry->d_inode);
731 if (!u)
732 goto put_fail;
733
734 if (u->sk_type == type)
735 touch_atime(nd.path.mnt, nd.path.dentry);
736
737 path_put(&nd.path);
738
739 err=-EPROTOTYPE;
740 if (u->sk_type != type) {
741 sock_put(u);
742 goto fail;
743 }
744 } else {
745 err = -ECONNREFUSED;
746 u=unix_find_socket_byname(net, sunname, len, type, hash);
747 if (u) {
748 struct dentry *dentry;
749 dentry = unix_sk(u)->dentry;
750 if (dentry)
751 touch_atime(unix_sk(u)->mnt, dentry);
752 } else
753 goto fail;
754 }
755 return u;
756
757 put_fail:
758 path_put(&nd.path);
759 fail:
760 *error=err;
761 return NULL;
762 }
763
764
765 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
766 {
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;
772 struct nameidata nd;
773 int err;
774 unsigned hash;
775 struct unix_address *addr;
776 struct hlist_head *list;
777
778 err = -EINVAL;
779 if (sunaddr->sun_family != AF_UNIX)
780 goto out;
781
782 if (addr_len==sizeof(short)) {
783 err = unix_autobind(sock);
784 goto out;
785 }
786
787 err = unix_mkname(sunaddr, addr_len, &hash);
788 if (err < 0)
789 goto out;
790 addr_len = err;
791
792 mutex_lock(&u->readlock);
793
794 err = -EINVAL;
795 if (u->addr)
796 goto out_up;
797
798 err = -ENOMEM;
799 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
800 if (!addr)
801 goto out_up;
802
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);
807
808 if (sunaddr->sun_path[0]) {
809 unsigned int mode;
810 err = 0;
811 /*
812 * Get the parent directory, calculate the hash for last
813 * component.
814 */
815 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
816 if (err)
817 goto out_mknod_parent;
818
819 dentry = lookup_create(&nd, 0);
820 err = PTR_ERR(dentry);
821 if (IS_ERR(dentry))
822 goto out_mknod_unlock;
823
824 /*
825 * All right, let's create it.
826 */
827 mode = S_IFSOCK |
828 (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
829 err = mnt_want_write(nd.path.mnt);
830 if (err)
831 goto out_mknod_dput;
832 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
833 mnt_drop_write(nd.path.mnt);
834 if (err)
835 goto out_mknod_dput;
836 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
837 dput(nd.path.dentry);
838 nd.path.dentry = dentry;
839
840 addr->hash = UNIX_HASH_SIZE;
841 }
842
843 spin_lock(&unix_table_lock);
844
845 if (!sunaddr->sun_path[0]) {
846 err = -EADDRINUSE;
847 if (__unix_find_socket_byname(net, sunaddr, addr_len,
848 sk->sk_type, hash)) {
849 unix_release_addr(addr);
850 goto out_unlock;
851 }
852
853 list = &unix_socket_table[addr->hash];
854 } else {
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;
858 }
859
860 err = 0;
861 __unix_remove_socket(sk);
862 u->addr = addr;
863 __unix_insert_socket(list, sk);
864
865 out_unlock:
866 spin_unlock(&unix_table_lock);
867 out_up:
868 mutex_unlock(&u->readlock);
869 out:
870 return err;
871
872 out_mknod_dput:
873 dput(dentry);
874 out_mknod_unlock:
875 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
876 path_put(&nd.path);
877 out_mknod_parent:
878 if (err==-EEXIST)
879 err=-EADDRINUSE;
880 unix_release_addr(addr);
881 goto out_up;
882 }
883
884 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
885 {
886 if (unlikely(sk1 == sk2) || !sk2) {
887 unix_state_lock(sk1);
888 return;
889 }
890 if (sk1 < sk2) {
891 unix_state_lock(sk1);
892 unix_state_lock_nested(sk2);
893 } else {
894 unix_state_lock(sk2);
895 unix_state_lock_nested(sk1);
896 }
897 }
898
899 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
900 {
901 if (unlikely(sk1 == sk2) || !sk2) {
902 unix_state_unlock(sk1);
903 return;
904 }
905 unix_state_unlock(sk1);
906 unix_state_unlock(sk2);
907 }
908
909 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
910 int alen, int flags)
911 {
912 struct sock *sk = sock->sk;
913 struct net *net = sock_net(sk);
914 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
915 struct sock *other;
916 unsigned hash;
917 int err;
918
919 if (addr->sa_family != AF_UNSPEC) {
920 err = unix_mkname(sunaddr, alen, &hash);
921 if (err < 0)
922 goto out;
923 alen = err;
924
925 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
926 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
927 goto out;
928
929 restart:
930 other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
931 if (!other)
932 goto out;
933
934 unix_state_double_lock(sk, other);
935
936 /* Apparently VFS overslept socket death. Retry. */
937 if (sock_flag(other, SOCK_DEAD)) {
938 unix_state_double_unlock(sk, other);
939 sock_put(other);
940 goto restart;
941 }
942
943 err = -EPERM;
944 if (!unix_may_send(sk, other))
945 goto out_unlock;
946
947 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
948 if (err)
949 goto out_unlock;
950
951 } else {
952 /*
953 * 1003.1g breaking connected state with AF_UNSPEC
954 */
955 other = NULL;
956 unix_state_double_lock(sk, other);
957 }
958
959 /*
960 * If it was connected, reconnect.
961 */
962 if (unix_peer(sk)) {
963 struct sock *old_peer = unix_peer(sk);
964 unix_peer(sk)=other;
965 unix_state_double_unlock(sk, other);
966
967 if (other != old_peer)
968 unix_dgram_disconnected(sk, old_peer);
969 sock_put(old_peer);
970 } else {
971 unix_peer(sk)=other;
972 unix_state_double_unlock(sk, other);
973 }
974 return 0;
975
976 out_unlock:
977 unix_state_double_unlock(sk, other);
978 sock_put(other);
979 out:
980 return err;
981 }
982
983 static long unix_wait_for_peer(struct sock *other, long timeo)
984 {
985 struct unix_sock *u = unix_sk(other);
986 int sched;
987 DEFINE_WAIT(wait);
988
989 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
990
991 sched = !sock_flag(other, SOCK_DEAD) &&
992 !(other->sk_shutdown & RCV_SHUTDOWN) &&
993 unix_recvq_full(other);
994
995 unix_state_unlock(other);
996
997 if (sched)
998 timeo = schedule_timeout(timeo);
999
1000 finish_wait(&u->peer_wait, &wait);
1001 return timeo;
1002 }
1003
1004 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1005 int addr_len, int flags)
1006 {
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;
1014 unsigned hash;
1015 int st;
1016 int err;
1017 long timeo;
1018
1019 err = unix_mkname(sunaddr, addr_len, &hash);
1020 if (err < 0)
1021 goto out;
1022 addr_len = err;
1023
1024 if (test_bit(SOCK_PASSCRED, &sock->flags)
1025 && !u->addr && (err = unix_autobind(sock)) != 0)
1026 goto out;
1027
1028 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1029
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.
1033 */
1034
1035 err = -ENOMEM;
1036
1037 /* create new sock for complete connection */
1038 newsk = unix_create1(sock_net(sk), NULL);
1039 if (newsk == NULL)
1040 goto out;
1041
1042 /* Allocate skb for sending to listening sock */
1043 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1044 if (skb == NULL)
1045 goto out;
1046
1047 restart:
1048 /* Find listening sock. */
1049 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1050 if (!other)
1051 goto out;
1052
1053 /* Latch state of peer */
1054 unix_state_lock(other);
1055
1056 /* Apparently VFS overslept socket death. Retry. */
1057 if (sock_flag(other, SOCK_DEAD)) {
1058 unix_state_unlock(other);
1059 sock_put(other);
1060 goto restart;
1061 }
1062
1063 err = -ECONNREFUSED;
1064 if (other->sk_state != TCP_LISTEN)
1065 goto out_unlock;
1066
1067 if (unix_recvq_full(other)) {
1068 err = -EAGAIN;
1069 if (!timeo)
1070 goto out_unlock;
1071
1072 timeo = unix_wait_for_peer(other, timeo);
1073
1074 err = sock_intr_errno(timeo);
1075 if (signal_pending(current))
1076 goto out;
1077 sock_put(other);
1078 goto restart;
1079 }
1080
1081 /* Latch our state.
1082
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.
1089
1090 Well, and we have to recheck the state after socket locked.
1091 */
1092 st = sk->sk_state;
1093
1094 switch (st) {
1095 case TCP_CLOSE:
1096 /* This is ok... continue with connect */
1097 break;
1098 case TCP_ESTABLISHED:
1099 /* Socket is already connected */
1100 err = -EISCONN;
1101 goto out_unlock;
1102 default:
1103 err = -EINVAL;
1104 goto out_unlock;
1105 }
1106
1107 unix_state_lock_nested(sk);
1108
1109 if (sk->sk_state != st) {
1110 unix_state_unlock(sk);
1111 unix_state_unlock(other);
1112 sock_put(other);
1113 goto restart;
1114 }
1115
1116 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1117 if (err) {
1118 unix_state_unlock(sk);
1119 goto out_unlock;
1120 }
1121
1122 /* The way is open! Fastly set all the necessary fields... */
1123
1124 sock_hold(sk);
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);
1134
1135 /* copy address information from listening to new sock*/
1136 if (otheru->addr) {
1137 atomic_inc(&otheru->addr->refcnt);
1138 newu->addr = otheru->addr;
1139 }
1140 if (otheru->dentry) {
1141 newu->dentry = dget(otheru->dentry);
1142 newu->mnt = mntget(otheru->mnt);
1143 }
1144
1145 /* Set credentials */
1146 sk->sk_peercred = other->sk_peercred;
1147
1148 sock->state = SS_CONNECTED;
1149 sk->sk_state = TCP_ESTABLISHED;
1150 sock_hold(newsk);
1151
1152 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1153 unix_peer(sk) = newsk;
1154
1155 unix_state_unlock(sk);
1156
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);
1163 sock_put(other);
1164 return 0;
1165
1166 out_unlock:
1167 if (other)
1168 unix_state_unlock(other);
1169
1170 out:
1171 if (skb)
1172 kfree_skb(skb);
1173 if (newsk)
1174 unix_release_sock(newsk, 0);
1175 if (other)
1176 sock_put(other);
1177 return err;
1178 }
1179
1180 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1181 {
1182 struct sock *ska=socka->sk, *skb = sockb->sk;
1183
1184 /* Join our sockets back to back */
1185 sock_hold(ska);
1186 sock_hold(skb);
1187 unix_peer(ska)=skb;
1188 unix_peer(skb)=ska;
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;
1192
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;
1198 }
1199 return 0;
1200 }
1201
1202 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1203 {
1204 struct sock *sk = sock->sk;
1205 struct sock *tsk;
1206 struct sk_buff *skb;
1207 int err;
1208
1209 err = -EOPNOTSUPP;
1210 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1211 goto out;
1212
1213 err = -EINVAL;
1214 if (sk->sk_state != TCP_LISTEN)
1215 goto out;
1216
1217 /* If socket state is TCP_LISTEN it cannot change (for now...),
1218 * so that no locks are necessary.
1219 */
1220
1221 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1222 if (!skb) {
1223 /* This means receive shutdown. */
1224 if (err == 0)
1225 err = -EINVAL;
1226 goto out;
1227 }
1228
1229 tsk = skb->sk;
1230 skb_free_datagram(sk, skb);
1231 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1232
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);
1238 return 0;
1239
1240 out:
1241 return err;
1242 }
1243
1244
1245 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1246 {
1247 struct sock *sk = sock->sk;
1248 struct unix_sock *u;
1249 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1250 int err = 0;
1251
1252 if (peer) {
1253 sk = unix_peer_get(sk);
1254
1255 err = -ENOTCONN;
1256 if (!sk)
1257 goto out;
1258 err = 0;
1259 } else {
1260 sock_hold(sk);
1261 }
1262
1263 u = unix_sk(sk);
1264 unix_state_lock(sk);
1265 if (!u->addr) {
1266 sunaddr->sun_family = AF_UNIX;
1267 sunaddr->sun_path[0] = 0;
1268 *uaddr_len = sizeof(short);
1269 } else {
1270 struct unix_address *addr = u->addr;
1271
1272 *uaddr_len = addr->len;
1273 memcpy(sunaddr, addr->name, *uaddr_len);
1274 }
1275 unix_state_unlock(sk);
1276 sock_put(sk);
1277 out:
1278 return err;
1279 }
1280
1281 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1282 {
1283 int i;
1284
1285 scm->fp = UNIXCB(skb).fp;
1286 skb->destructor = sock_wfree;
1287 UNIXCB(skb).fp = NULL;
1288
1289 for (i=scm->fp->count-1; i>=0; i--)
1290 unix_notinflight(scm->fp->fp[i]);
1291 }
1292
1293 static void unix_destruct_fds(struct sk_buff *skb)
1294 {
1295 struct scm_cookie scm;
1296 memset(&scm, 0, sizeof(scm));
1297 unix_detach_fds(&scm, skb);
1298
1299 /* Alas, it calls VFS */
1300 /* So fscking what? fput() had been SMP-safe since the last Summer */
1301 scm_destroy(&scm);
1302 sock_wfree(skb);
1303 }
1304
1305 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1306 {
1307 int i;
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;
1312 scm->fp = NULL;
1313 }
1314
1315 /*
1316 * Send AF_UNIX data.
1317 */
1318
1319 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1320 struct msghdr *msg, size_t len)
1321 {
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 */
1329 int err;
1330 unsigned hash;
1331 struct sk_buff *skb;
1332 long timeo;
1333 struct scm_cookie tmp_scm;
1334
1335 if (NULL == siocb->scm)
1336 siocb->scm = &tmp_scm;
1337 err = scm_send(sock, msg, siocb->scm);
1338 if (err < 0)
1339 return err;
1340
1341 err = -EOPNOTSUPP;
1342 if (msg->msg_flags&MSG_OOB)
1343 goto out;
1344
1345 if (msg->msg_namelen) {
1346 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1347 if (err < 0)
1348 goto out;
1349 namelen = err;
1350 } else {
1351 sunaddr = NULL;
1352 err = -ENOTCONN;
1353 other = unix_peer_get(sk);
1354 if (!other)
1355 goto out;
1356 }
1357
1358 if (test_bit(SOCK_PASSCRED, &sock->flags)
1359 && !u->addr && (err = unix_autobind(sock)) != 0)
1360 goto out;
1361
1362 err = -EMSGSIZE;
1363 if (len > sk->sk_sndbuf - 32)
1364 goto out;
1365
1366 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1367 if (skb==NULL)
1368 goto out;
1369
1370 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1371 if (siocb->scm->fp)
1372 unix_attach_fds(siocb->scm, skb);
1373 unix_get_secdata(siocb->scm, skb);
1374
1375 skb_reset_transport_header(skb);
1376 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1377 if (err)
1378 goto out_free;
1379
1380 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1381
1382 restart:
1383 if (!other) {
1384 err = -ECONNRESET;
1385 if (sunaddr == NULL)
1386 goto out_free;
1387
1388 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1389 hash, &err);
1390 if (other==NULL)
1391 goto out_free;
1392 }
1393
1394 unix_state_lock(other);
1395 err = -EPERM;
1396 if (!unix_may_send(sk, other))
1397 goto out_unlock;
1398
1399 if (sock_flag(other, SOCK_DEAD)) {
1400 /*
1401 * Check with 1003.1g - what should
1402 * datagram error
1403 */
1404 unix_state_unlock(other);
1405 sock_put(other);
1406
1407 err = 0;
1408 unix_state_lock(sk);
1409 if (unix_peer(sk) == other) {
1410 unix_peer(sk)=NULL;
1411 unix_state_unlock(sk);
1412
1413 unix_dgram_disconnected(sk, other);
1414 sock_put(other);
1415 err = -ECONNREFUSED;
1416 } else {
1417 unix_state_unlock(sk);
1418 }
1419
1420 other = NULL;
1421 if (err)
1422 goto out_free;
1423 goto restart;
1424 }
1425
1426 err = -EPIPE;
1427 if (other->sk_shutdown & RCV_SHUTDOWN)
1428 goto out_unlock;
1429
1430 if (sk->sk_type != SOCK_SEQPACKET) {
1431 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1432 if (err)
1433 goto out_unlock;
1434 }
1435
1436 if (unix_peer(other) != sk && unix_recvq_full(other)) {
1437 if (!timeo) {
1438 err = -EAGAIN;
1439 goto out_unlock;
1440 }
1441
1442 timeo = unix_wait_for_peer(other, timeo);
1443
1444 err = sock_intr_errno(timeo);
1445 if (signal_pending(current))
1446 goto out_free;
1447
1448 goto restart;
1449 }
1450
1451 skb_queue_tail(&other->sk_receive_queue, skb);
1452 unix_state_unlock(other);
1453 other->sk_data_ready(other, len);
1454 sock_put(other);
1455 scm_destroy(siocb->scm);
1456 return len;
1457
1458 out_unlock:
1459 unix_state_unlock(other);
1460 out_free:
1461 kfree_skb(skb);
1462 out:
1463 if (other)
1464 sock_put(other);
1465 scm_destroy(siocb->scm);
1466 return err;
1467 }
1468
1469
1470 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1471 struct msghdr *msg, size_t len)
1472 {
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;
1477 int err,size;
1478 struct sk_buff *skb;
1479 int sent=0;
1480 struct scm_cookie tmp_scm;
1481
1482 if (NULL == siocb->scm)
1483 siocb->scm = &tmp_scm;
1484 err = scm_send(sock, msg, siocb->scm);
1485 if (err < 0)
1486 return err;
1487
1488 err = -EOPNOTSUPP;
1489 if (msg->msg_flags&MSG_OOB)
1490 goto out_err;
1491
1492 if (msg->msg_namelen) {
1493 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1494 goto out_err;
1495 } else {
1496 sunaddr = NULL;
1497 err = -ENOTCONN;
1498 other = unix_peer(sk);
1499 if (!other)
1500 goto out_err;
1501 }
1502
1503 if (sk->sk_shutdown & SEND_SHUTDOWN)
1504 goto pipe_err;
1505
1506 while(sent < len)
1507 {
1508 /*
1509 * Optimisation for the fact that under 0.01% of X
1510 * messages typically need breaking up.
1511 */
1512
1513 size = len-sent;
1514
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;
1518
1519 if (size > SKB_MAX_ALLOC)
1520 size = SKB_MAX_ALLOC;
1521
1522 /*
1523 * Grab a buffer
1524 */
1525
1526 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1527
1528 if (skb==NULL)
1529 goto out_err;
1530
1531 /*
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
1536 * succeed. [Alan]
1537 */
1538 size = min_t(int, size, skb_tailroom(skb));
1539
1540 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1541 if (siocb->scm->fp)
1542 unix_attach_fds(siocb->scm, skb);
1543
1544 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1545 kfree_skb(skb);
1546 goto out_err;
1547 }
1548
1549 unix_state_lock(other);
1550
1551 if (sock_flag(other, SOCK_DEAD) ||
1552 (other->sk_shutdown & RCV_SHUTDOWN))
1553 goto pipe_err_free;
1554
1555 skb_queue_tail(&other->sk_receive_queue, skb);
1556 unix_state_unlock(other);
1557 other->sk_data_ready(other, size);
1558 sent+=size;
1559 }
1560
1561 scm_destroy(siocb->scm);
1562 siocb->scm = NULL;
1563
1564 return sent;
1565
1566 pipe_err_free:
1567 unix_state_unlock(other);
1568 kfree_skb(skb);
1569 pipe_err:
1570 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1571 send_sig(SIGPIPE,current,0);
1572 err = -EPIPE;
1573 out_err:
1574 scm_destroy(siocb->scm);
1575 siocb->scm = NULL;
1576 return sent ? : err;
1577 }
1578
1579 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1580 struct msghdr *msg, size_t len)
1581 {
1582 int err;
1583 struct sock *sk = sock->sk;
1584
1585 err = sock_error(sk);
1586 if (err)
1587 return err;
1588
1589 if (sk->sk_state != TCP_ESTABLISHED)
1590 return -ENOTCONN;
1591
1592 if (msg->msg_namelen)
1593 msg->msg_namelen = 0;
1594
1595 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1596 }
1597
1598 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1599 {
1600 struct unix_sock *u = unix_sk(sk);
1601
1602 msg->msg_namelen = 0;
1603 if (u->addr) {
1604 msg->msg_namelen = u->addr->len;
1605 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1606 }
1607 }
1608
1609 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1610 struct msghdr *msg, size_t size,
1611 int flags)
1612 {
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;
1619 int err;
1620
1621 err = -EOPNOTSUPP;
1622 if (flags&MSG_OOB)
1623 goto out;
1624
1625 msg->msg_namelen = 0;
1626
1627 mutex_lock(&u->readlock);
1628
1629 skb = skb_recv_datagram(sk, flags, noblock, &err);
1630 if (!skb) {
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))
1635 err = 0;
1636 unix_state_unlock(sk);
1637 goto out_unlock;
1638 }
1639
1640 wake_up_interruptible_sync(&u->peer_wait);
1641
1642 if (msg->msg_name)
1643 unix_copy_addr(msg, skb->sk);
1644
1645 if (size > skb->len)
1646 size = skb->len;
1647 else if (size < skb->len)
1648 msg->msg_flags |= MSG_TRUNC;
1649
1650 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1651 if (err)
1652 goto out_free;
1653
1654 if (!siocb->scm) {
1655 siocb->scm = &tmp_scm;
1656 memset(&tmp_scm, 0, sizeof(tmp_scm));
1657 }
1658 siocb->scm->creds = *UNIXCREDS(skb);
1659 unix_set_secdata(siocb->scm, skb);
1660
1661 if (!(flags & MSG_PEEK))
1662 {
1663 if (UNIXCB(skb).fp)
1664 unix_detach_fds(siocb->scm, skb);
1665 }
1666 else
1667 {
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,
1671 apparently wrong)
1672 - clone fds (I chose it for now, it is the most universal
1673 solution)
1674
1675 POSIX 1003.1g does not actually define this clearly
1676 at all. POSIX 1003.1g doesn't define a lot of things
1677 clearly however!
1678
1679 */
1680 if (UNIXCB(skb).fp)
1681 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1682 }
1683 err = size;
1684
1685 scm_recv(sock, msg, siocb->scm, flags);
1686
1687 out_free:
1688 skb_free_datagram(sk,skb);
1689 out_unlock:
1690 mutex_unlock(&u->readlock);
1691 out:
1692 return err;
1693 }
1694
1695 /*
1696 * Sleep until data has arrive. But check for races..
1697 */
1698
1699 static long unix_stream_data_wait(struct sock * sk, long timeo)
1700 {
1701 DEFINE_WAIT(wait);
1702
1703 unix_state_lock(sk);
1704
1705 for (;;) {
1706 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1707
1708 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1709 sk->sk_err ||
1710 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1711 signal_pending(current) ||
1712 !timeo)
1713 break;
1714
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);
1720 }
1721
1722 finish_wait(sk->sk_sleep, &wait);
1723 unix_state_unlock(sk);
1724 return timeo;
1725 }
1726
1727
1728
1729 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1730 struct msghdr *msg, size_t size,
1731 int flags)
1732 {
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;
1738 int copied = 0;
1739 int check_creds = 0;
1740 int target;
1741 int err = 0;
1742 long timeo;
1743
1744 err = -EINVAL;
1745 if (sk->sk_state != TCP_ESTABLISHED)
1746 goto out;
1747
1748 err = -EOPNOTSUPP;
1749 if (flags&MSG_OOB)
1750 goto out;
1751
1752 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1753 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1754
1755 msg->msg_namelen = 0;
1756
1757 /* Lock the socket to prevent queue disordering
1758 * while sleeps in memcpy_tomsg
1759 */
1760
1761 if (!siocb->scm) {
1762 siocb->scm = &tmp_scm;
1763 memset(&tmp_scm, 0, sizeof(tmp_scm));
1764 }
1765
1766 mutex_lock(&u->readlock);
1767
1768 do
1769 {
1770 int chunk;
1771 struct sk_buff *skb;
1772
1773 unix_state_lock(sk);
1774 skb = skb_dequeue(&sk->sk_receive_queue);
1775 if (skb==NULL)
1776 {
1777 if (copied >= target)
1778 goto unlock;
1779
1780 /*
1781 * POSIX 1003.1g mandates this order.
1782 */
1783
1784 if ((err = sock_error(sk)) != 0)
1785 goto unlock;
1786 if (sk->sk_shutdown & RCV_SHUTDOWN)
1787 goto unlock;
1788
1789 unix_state_unlock(sk);
1790 err = -EAGAIN;
1791 if (!timeo)
1792 break;
1793 mutex_unlock(&u->readlock);
1794
1795 timeo = unix_stream_data_wait(sk, timeo);
1796
1797 if (signal_pending(current)) {
1798 err = sock_intr_errno(timeo);
1799 goto out;
1800 }
1801 mutex_lock(&u->readlock);
1802 continue;
1803 unlock:
1804 unix_state_unlock(sk);
1805 break;
1806 }
1807 unix_state_unlock(sk);
1808
1809 if (check_creds) {
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);
1813 break;
1814 }
1815 } else {
1816 /* Copy credentials */
1817 siocb->scm->creds = *UNIXCREDS(skb);
1818 check_creds = 1;
1819 }
1820
1821 /* Copy address just once */
1822 if (sunaddr)
1823 {
1824 unix_copy_addr(msg, skb->sk);
1825 sunaddr = NULL;
1826 }
1827
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);
1831 if (copied == 0)
1832 copied = -EFAULT;
1833 break;
1834 }
1835 copied += chunk;
1836 size -= chunk;
1837
1838 /* Mark read part of skb as used */
1839 if (!(flags & MSG_PEEK))
1840 {
1841 skb_pull(skb, chunk);
1842
1843 if (UNIXCB(skb).fp)
1844 unix_detach_fds(siocb->scm, skb);
1845
1846 /* put the skb back if we didn't use it up.. */
1847 if (skb->len)
1848 {
1849 skb_queue_head(&sk->sk_receive_queue, skb);
1850 break;
1851 }
1852
1853 kfree_skb(skb);
1854
1855 if (siocb->scm->fp)
1856 break;
1857 }
1858 else
1859 {
1860 /* It is questionable, see note in unix_dgram_recvmsg.
1861 */
1862 if (UNIXCB(skb).fp)
1863 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1864
1865 /* put message back and return */
1866 skb_queue_head(&sk->sk_receive_queue, skb);
1867 break;
1868 }
1869 } while (size);
1870
1871 mutex_unlock(&u->readlock);
1872 scm_recv(sock, msg, siocb->scm, flags);
1873 out:
1874 return copied ? : err;
1875 }
1876
1877 static int unix_shutdown(struct socket *sock, int mode)
1878 {
1879 struct sock *sk = sock->sk;
1880 struct sock *other;
1881
1882 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1883
1884 if (mode) {
1885 unix_state_lock(sk);
1886 sk->sk_shutdown |= mode;
1887 other=unix_peer(sk);
1888 if (other)
1889 sock_hold(other);
1890 unix_state_unlock(sk);
1891 sk->sk_state_change(sk);
1892
1893 if (other &&
1894 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1895
1896 int peer_mode = 0;
1897
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);
1912 }
1913 if (other)
1914 sock_put(other);
1915 }
1916 return 0;
1917 }
1918
1919 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1920 {
1921 struct sock *sk = sock->sk;
1922 long amount=0;
1923 int err;
1924
1925 switch(cmd)
1926 {
1927 case SIOCOUTQ:
1928 amount = atomic_read(&sk->sk_wmem_alloc);
1929 err = put_user(amount, (int __user *)arg);
1930 break;
1931 case SIOCINQ:
1932 {
1933 struct sk_buff *skb;
1934
1935 if (sk->sk_state == TCP_LISTEN) {
1936 err = -EINVAL;
1937 break;
1938 }
1939
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)
1944 amount += skb->len;
1945 } else {
1946 skb = skb_peek(&sk->sk_receive_queue);
1947 if (skb)
1948 amount=skb->len;
1949 }
1950 spin_unlock(&sk->sk_receive_queue.lock);
1951 err = put_user(amount, (int __user *)arg);
1952 break;
1953 }
1954
1955 default:
1956 err = -ENOIOCTLCMD;
1957 break;
1958 }
1959 return err;
1960 }
1961
1962 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1963 {
1964 struct sock *sk = sock->sk;
1965 unsigned int mask;
1966
1967 poll_wait(file, sk->sk_sleep, wait);
1968 mask = 0;
1969
1970 /* exceptional events? */
1971 if (sk->sk_err)
1972 mask |= POLLERR;
1973 if (sk->sk_shutdown == SHUTDOWN_MASK)
1974 mask |= POLLHUP;
1975 if (sk->sk_shutdown & RCV_SHUTDOWN)
1976 mask |= POLLRDHUP;
1977
1978 /* readable? */
1979 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1980 (sk->sk_shutdown & RCV_SHUTDOWN))
1981 mask |= POLLIN | POLLRDNORM;
1982
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)
1985 mask |= POLLHUP;
1986
1987 /*
1988 * we set writable also when the other side has shut down the
1989 * connection. This prevents stuck sockets.
1990 */
1991 if (unix_writable(sk))
1992 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1993
1994 return mask;
1995 }
1996
1997 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
1998 poll_table *wait)
1999 {
2000 struct sock *sk = sock->sk, *other;
2001 unsigned int mask, writable;
2002
2003 poll_wait(file, sk->sk_sleep, wait);
2004 mask = 0;
2005
2006 /* exceptional events? */
2007 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2008 mask |= POLLERR;
2009 if (sk->sk_shutdown & RCV_SHUTDOWN)
2010 mask |= POLLRDHUP;
2011 if (sk->sk_shutdown == SHUTDOWN_MASK)
2012 mask |= POLLHUP;
2013
2014 /* readable? */
2015 if (!skb_queue_empty(&sk->sk_receive_queue) ||
2016 (sk->sk_shutdown & RCV_SHUTDOWN))
2017 mask |= POLLIN | POLLRDNORM;
2018
2019 /* Connection-based need to check for termination and startup */
2020 if (sk->sk_type == SOCK_SEQPACKET) {
2021 if (sk->sk_state == TCP_CLOSE)
2022 mask |= POLLHUP;
2023 /* connection hasn't started yet? */
2024 if (sk->sk_state == TCP_SYN_SENT)
2025 return mask;
2026 }
2027
2028 /* writable? */
2029 writable = unix_writable(sk);
2030 if (writable) {
2031 other = unix_peer_get(sk);
2032 if (other) {
2033 if (unix_peer(other) != sk) {
2034 poll_wait(file, &unix_sk(other)->peer_wait,
2035 wait);
2036 if (unix_recvq_full(other))
2037 writable = 0;
2038 }
2039
2040 sock_put(other);
2041 }
2042 }
2043
2044 if (writable)
2045 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2046 else
2047 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2048
2049 return mask;
2050 }
2051
2052 #ifdef CONFIG_PROC_FS
2053 static struct sock *first_unix_socket(int *i)
2054 {
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]);
2058 }
2059 return NULL;
2060 }
2061
2062 static struct sock *next_unix_socket(int *i, struct sock *s)
2063 {
2064 struct sock *next = sk_next(s);
2065 /* More in this chain? */
2066 if (next)
2067 return next;
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]);
2072 }
2073 return NULL;
2074 }
2075
2076 struct unix_iter_state {
2077 struct seq_net_private p;
2078 int i;
2079 };
2080 static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
2081 {
2082 struct unix_iter_state *iter = seq->private;
2083 loff_t off = 0;
2084 struct sock *s;
2085
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))
2088 continue;
2089 if (off == pos)
2090 return s;
2091 ++off;
2092 }
2093 return NULL;
2094 }
2095
2096
2097 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2098 __acquires(unix_table_lock)
2099 {
2100 spin_lock(&unix_table_lock);
2101 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2102 }
2103
2104 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2105 {
2106 struct unix_iter_state *iter = seq->private;
2107 struct sock *sk = v;
2108 ++*pos;
2109
2110 if (v == SEQ_START_TOKEN)
2111 sk = first_unix_socket(&iter->i);
2112 else
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);
2116 return sk;
2117 }
2118
2119 static void unix_seq_stop(struct seq_file *seq, void *v)
2120 __releases(unix_table_lock)
2121 {
2122 spin_unlock(&unix_table_lock);
2123 }
2124
2125 static int unix_seq_show(struct seq_file *seq, void *v)
2126 {
2127
2128 if (v == SEQ_START_TOKEN)
2129 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2130 "Inode Path\n");
2131 else {
2132 struct sock *s = v;
2133 struct unix_sock *u = unix_sk(s);
2134 unix_state_lock(s);
2135
2136 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2137 s,
2138 atomic_read(&s->sk_refcnt),
2139 0,
2140 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2141 s->sk_type,
2142 s->sk_socket ?
2143 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2144 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2145 sock_i_ino(s));
2146
2147 if (u->addr) {
2148 int i, len;
2149 seq_putc(seq, ' ');
2150
2151 i = 0;
2152 len = u->addr->len - sizeof(short);
2153 if (!UNIX_ABSTRACT(s))
2154 len--;
2155 else {
2156 seq_putc(seq, '@');
2157 i++;
2158 }
2159 for ( ; i < len; i++)
2160 seq_putc(seq, u->addr->name->sun_path[i]);
2161 }
2162 unix_state_unlock(s);
2163 seq_putc(seq, '\n');
2164 }
2165
2166 return 0;
2167 }
2168
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,
2174 };
2175
2176
2177 static int unix_seq_open(struct inode *inode, struct file *file)
2178 {
2179 return seq_open_net(inode, file, &unix_seq_ops,
2180 sizeof(struct unix_iter_state));
2181 }
2182
2183 static const struct file_operations unix_seq_fops = {
2184 .owner = THIS_MODULE,
2185 .open = unix_seq_open,
2186 .read = seq_read,
2187 .llseek = seq_lseek,
2188 .release = seq_release_net,
2189 };
2190
2191 #endif
2192
2193 static struct net_proto_family unix_family_ops = {
2194 .family = PF_UNIX,
2195 .create = unix_create,
2196 .owner = THIS_MODULE,
2197 };
2198
2199
2200 static int unix_net_init(struct net *net)
2201 {
2202 int error = -ENOMEM;
2203
2204 net->unx.sysctl_max_dgram_qlen = 10;
2205 if (unix_sysctl_register(net))
2206 goto out;
2207
2208 #ifdef CONFIG_PROC_FS
2209 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2210 unix_sysctl_unregister(net);
2211 goto out;
2212 }
2213 #endif
2214 error = 0;
2215 out:
2216 return 0;
2217 }
2218
2219 static void unix_net_exit(struct net *net)
2220 {
2221 unix_sysctl_unregister(net);
2222 proc_net_remove(net, "unix");
2223 }
2224
2225 static struct pernet_operations unix_net_ops = {
2226 .init = unix_net_init,
2227 .exit = unix_net_exit,
2228 };
2229
2230 static int __init af_unix_init(void)
2231 {
2232 int rc = -1;
2233 struct sk_buff *dummy_skb;
2234
2235 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2236
2237 rc = proto_register(&unix_proto, 1);
2238 if (rc != 0) {
2239 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2240 __func__);
2241 goto out;
2242 }
2243
2244 sock_register(&unix_family_ops);
2245 register_pernet_subsys(&unix_net_ops);
2246 out:
2247 return rc;
2248 }
2249
2250 static void __exit af_unix_exit(void)
2251 {
2252 sock_unregister(PF_UNIX);
2253 proto_unregister(&unix_proto);
2254 unregister_pernet_subsys(&unix_net_ops);
2255 }
2256
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);
2263
2264 MODULE_LICENSE("GPL");
2265 MODULE_ALIAS_NETPROTO(PF_UNIX);
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