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CRED: Wrap task credential accesses in the UNIX socket protocol
[linux-2.6.git] / net / unix / af_unix.c
blob338c1aec708944262c793fbdb6898dcc6e5eaa27
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
118 static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
119 static DEFINE_SPINLOCK(unix_table_lock);
120 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
121
122 #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
123
124 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
125
126 #ifdef CONFIG_SECURITY_NETWORK
127 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
128 {
129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
130 }
131
132 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
133 {
134 scm->secid = *UNIXSID(skb);
135 }
136 #else
137 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
138 { }
139
140 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
141 { }
142 #endif /* CONFIG_SECURITY_NETWORK */
143
144 /*
145 * SMP locking strategy:
146 * hash table is protected with spinlock unix_table_lock
147 * each socket state is protected by separate rwlock.
148 */
149
150 static inline unsigned unix_hash_fold(__wsum n)
151 {
152 unsigned hash = (__force unsigned)n;
153 hash ^= hash>>16;
154 hash ^= hash>>8;
155 return hash&(UNIX_HASH_SIZE-1);
156 }
157
158 #define unix_peer(sk) (unix_sk(sk)->peer)
159
160 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
161 {
162 return unix_peer(osk) == sk;
163 }
164
165 static inline int unix_may_send(struct sock *sk, struct sock *osk)
166 {
167 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
168 }
169
170 static inline int unix_recvq_full(struct sock const *sk)
171 {
172 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
173 }
174
175 static struct sock *unix_peer_get(struct sock *s)
176 {
177 struct sock *peer;
178
179 unix_state_lock(s);
180 peer = unix_peer(s);
181 if (peer)
182 sock_hold(peer);
183 unix_state_unlock(s);
184 return peer;
185 }
186
187 static inline void unix_release_addr(struct unix_address *addr)
188 {
189 if (atomic_dec_and_test(&addr->refcnt))
190 kfree(addr);
191 }
192
193 /*
194 * Check unix socket name:
195 * - should be not zero length.
196 * - if started by not zero, should be NULL terminated (FS object)
197 * - if started by zero, it is abstract name.
198 */
199
200 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
201 {
202 if (len <= sizeof(short) || len > sizeof(*sunaddr))
203 return -EINVAL;
204 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
205 return -EINVAL;
206 if (sunaddr->sun_path[0]) {
207 /*
208 * This may look like an off by one error but it is a bit more
209 * subtle. 108 is the longest valid AF_UNIX path for a binding.
210 * sun_path[108] doesnt as such exist. However in kernel space
211 * we are guaranteed that it is a valid memory location in our
212 * kernel address buffer.
213 */
214 ((char *)sunaddr)[len]=0;
215 len = strlen(sunaddr->sun_path)+1+sizeof(short);
216 return len;
217 }
218
219 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
220 return len;
221 }
222
223 static void __unix_remove_socket(struct sock *sk)
224 {
225 sk_del_node_init(sk);
226 }
227
228 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
229 {
230 WARN_ON(!sk_unhashed(sk));
231 sk_add_node(sk, list);
232 }
233
234 static inline void unix_remove_socket(struct sock *sk)
235 {
236 spin_lock(&unix_table_lock);
237 __unix_remove_socket(sk);
238 spin_unlock(&unix_table_lock);
239 }
240
241 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
242 {
243 spin_lock(&unix_table_lock);
244 __unix_insert_socket(list, sk);
245 spin_unlock(&unix_table_lock);
246 }
247
248 static struct sock *__unix_find_socket_byname(struct net *net,
249 struct sockaddr_un *sunname,
250 int len, int type, unsigned hash)
251 {
252 struct sock *s;
253 struct hlist_node *node;
254
255 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
256 struct unix_sock *u = unix_sk(s);
257
258 if (!net_eq(sock_net(s), net))
259 continue;
260
261 if (u->addr->len == len &&
262 !memcmp(u->addr->name, sunname, len))
263 goto found;
264 }
265 s = NULL;
266 found:
267 return s;
268 }
269
270 static inline struct sock *unix_find_socket_byname(struct net *net,
271 struct sockaddr_un *sunname,
272 int len, int type,
273 unsigned hash)
274 {
275 struct sock *s;
276
277 spin_lock(&unix_table_lock);
278 s = __unix_find_socket_byname(net, sunname, len, type, hash);
279 if (s)
280 sock_hold(s);
281 spin_unlock(&unix_table_lock);
282 return s;
283 }
284
285 static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
286 {
287 struct sock *s;
288 struct hlist_node *node;
289
290 spin_lock(&unix_table_lock);
291 sk_for_each(s, node,
292 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
293 struct dentry *dentry = unix_sk(s)->dentry;
294
295 if (!net_eq(sock_net(s), net))
296 continue;
297
298 if(dentry && dentry->d_inode == i)
299 {
300 sock_hold(s);
301 goto found;
302 }
303 }
304 s = NULL;
305 found:
306 spin_unlock(&unix_table_lock);
307 return s;
308 }
309
310 static inline int unix_writable(struct sock *sk)
311 {
312 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
313 }
314
315 static void unix_write_space(struct sock *sk)
316 {
317 read_lock(&sk->sk_callback_lock);
318 if (unix_writable(sk)) {
319 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
320 wake_up_interruptible_sync(sk->sk_sleep);
321 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
322 }
323 read_unlock(&sk->sk_callback_lock);
324 }
325
326 /* When dgram socket disconnects (or changes its peer), we clear its receive
327 * queue of packets arrived from previous peer. First, it allows to do
328 * flow control based only on wmem_alloc; second, sk connected to peer
329 * may receive messages only from that peer. */
330 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
331 {
332 if (!skb_queue_empty(&sk->sk_receive_queue)) {
333 skb_queue_purge(&sk->sk_receive_queue);
334 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
335
336 /* If one link of bidirectional dgram pipe is disconnected,
337 * we signal error. Messages are lost. Do not make this,
338 * when peer was not connected to us.
339 */
340 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
341 other->sk_err = ECONNRESET;
342 other->sk_error_report(other);
343 }
344 }
345 }
346
347 static void unix_sock_destructor(struct sock *sk)
348 {
349 struct unix_sock *u = unix_sk(sk);
350
351 skb_queue_purge(&sk->sk_receive_queue);
352
353 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
354 WARN_ON(!sk_unhashed(sk));
355 WARN_ON(sk->sk_socket);
356 if (!sock_flag(sk, SOCK_DEAD)) {
357 printk("Attempt to release alive unix socket: %p\n", sk);
358 return;
359 }
360
361 if (u->addr)
362 unix_release_addr(u->addr);
363
364 atomic_dec(&unix_nr_socks);
365 #ifdef UNIX_REFCNT_DEBUG
366 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
367 #endif
368 }
369
370 static int unix_release_sock (struct sock *sk, int embrion)
371 {
372 struct unix_sock *u = unix_sk(sk);
373 struct dentry *dentry;
374 struct vfsmount *mnt;
375 struct sock *skpair;
376 struct sk_buff *skb;
377 int state;
378
379 unix_remove_socket(sk);
380
381 /* Clear state */
382 unix_state_lock(sk);
383 sock_orphan(sk);
384 sk->sk_shutdown = SHUTDOWN_MASK;
385 dentry = u->dentry;
386 u->dentry = NULL;
387 mnt = u->mnt;
388 u->mnt = NULL;
389 state = sk->sk_state;
390 sk->sk_state = TCP_CLOSE;
391 unix_state_unlock(sk);
392
393 wake_up_interruptible_all(&u->peer_wait);
394
395 skpair=unix_peer(sk);
396
397 if (skpair!=NULL) {
398 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
399 unix_state_lock(skpair);
400 /* No more writes */
401 skpair->sk_shutdown = SHUTDOWN_MASK;
402 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
403 skpair->sk_err = ECONNRESET;
404 unix_state_unlock(skpair);
405 skpair->sk_state_change(skpair);
406 read_lock(&skpair->sk_callback_lock);
407 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
408 read_unlock(&skpair->sk_callback_lock);
409 }
410 sock_put(skpair); /* It may now die */
411 unix_peer(sk) = NULL;
412 }
413
414 /* Try to flush out this socket. Throw out buffers at least */
415
416 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
417 if (state==TCP_LISTEN)
418 unix_release_sock(skb->sk, 1);
419 /* passed fds are erased in the kfree_skb hook */
420 kfree_skb(skb);
421 }
422
423 if (dentry) {
424 dput(dentry);
425 mntput(mnt);
426 }
427
428 sock_put(sk);
429
430 /* ---- Socket is dead now and most probably destroyed ---- */
431
432 /*
433 * Fixme: BSD difference: In BSD all sockets connected to use get
434 * ECONNRESET and we die on the spot. In Linux we behave
435 * like files and pipes do and wait for the last
436 * dereference.
437 *
438 * Can't we simply set sock->err?
439 *
440 * What the above comment does talk about? --ANK(980817)
441 */
442
443 if (unix_tot_inflight)
444 unix_gc(); /* Garbage collect fds */
445
446 return 0;
447 }
448
449 static int unix_listen(struct socket *sock, int backlog)
450 {
451 int err;
452 struct sock *sk = sock->sk;
453 struct unix_sock *u = unix_sk(sk);
454
455 err = -EOPNOTSUPP;
456 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
457 goto out; /* Only stream/seqpacket sockets accept */
458 err = -EINVAL;
459 if (!u->addr)
460 goto out; /* No listens on an unbound socket */
461 unix_state_lock(sk);
462 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
463 goto out_unlock;
464 if (backlog > sk->sk_max_ack_backlog)
465 wake_up_interruptible_all(&u->peer_wait);
466 sk->sk_max_ack_backlog = backlog;
467 sk->sk_state = TCP_LISTEN;
468 /* set credentials so connect can copy them */
469 sk->sk_peercred.pid = task_tgid_vnr(current);
470 current_euid_egid(&sk->sk_peercred.uid, &sk->sk_peercred.gid);
471 err = 0;
472
473 out_unlock:
474 unix_state_unlock(sk);
475 out:
476 return err;
477 }
478
479 static int unix_release(struct socket *);
480 static int unix_bind(struct socket *, struct sockaddr *, int);
481 static int unix_stream_connect(struct socket *, struct sockaddr *,
482 int addr_len, int flags);
483 static int unix_socketpair(struct socket *, struct socket *);
484 static int unix_accept(struct socket *, struct socket *, int);
485 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
486 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
487 static unsigned int unix_dgram_poll(struct file *, struct socket *,
488 poll_table *);
489 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
490 static int unix_shutdown(struct socket *, int);
491 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
492 struct msghdr *, size_t);
493 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
494 struct msghdr *, size_t, int);
495 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
496 struct msghdr *, size_t);
497 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
498 struct msghdr *, size_t, int);
499 static int unix_dgram_connect(struct socket *, struct sockaddr *,
500 int, int);
501 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
502 struct msghdr *, size_t);
503
504 static const struct proto_ops unix_stream_ops = {
505 .family = PF_UNIX,
506 .owner = THIS_MODULE,
507 .release = unix_release,
508 .bind = unix_bind,
509 .connect = unix_stream_connect,
510 .socketpair = unix_socketpair,
511 .accept = unix_accept,
512 .getname = unix_getname,
513 .poll = unix_poll,
514 .ioctl = unix_ioctl,
515 .listen = unix_listen,
516 .shutdown = unix_shutdown,
517 .setsockopt = sock_no_setsockopt,
518 .getsockopt = sock_no_getsockopt,
519 .sendmsg = unix_stream_sendmsg,
520 .recvmsg = unix_stream_recvmsg,
521 .mmap = sock_no_mmap,
522 .sendpage = sock_no_sendpage,
523 };
524
525 static const struct proto_ops unix_dgram_ops = {
526 .family = PF_UNIX,
527 .owner = THIS_MODULE,
528 .release = unix_release,
529 .bind = unix_bind,
530 .connect = unix_dgram_connect,
531 .socketpair = unix_socketpair,
532 .accept = sock_no_accept,
533 .getname = unix_getname,
534 .poll = unix_dgram_poll,
535 .ioctl = unix_ioctl,
536 .listen = sock_no_listen,
537 .shutdown = unix_shutdown,
538 .setsockopt = sock_no_setsockopt,
539 .getsockopt = sock_no_getsockopt,
540 .sendmsg = unix_dgram_sendmsg,
541 .recvmsg = unix_dgram_recvmsg,
542 .mmap = sock_no_mmap,
543 .sendpage = sock_no_sendpage,
544 };
545
546 static const struct proto_ops unix_seqpacket_ops = {
547 .family = PF_UNIX,
548 .owner = THIS_MODULE,
549 .release = unix_release,
550 .bind = unix_bind,
551 .connect = unix_stream_connect,
552 .socketpair = unix_socketpair,
553 .accept = unix_accept,
554 .getname = unix_getname,
555 .poll = unix_dgram_poll,
556 .ioctl = unix_ioctl,
557 .listen = unix_listen,
558 .shutdown = unix_shutdown,
559 .setsockopt = sock_no_setsockopt,
560 .getsockopt = sock_no_getsockopt,
561 .sendmsg = unix_seqpacket_sendmsg,
562 .recvmsg = unix_dgram_recvmsg,
563 .mmap = sock_no_mmap,
564 .sendpage = sock_no_sendpage,
565 };
566
567 static struct proto unix_proto = {
568 .name = "UNIX",
569 .owner = THIS_MODULE,
570 .obj_size = sizeof(struct unix_sock),
571 };
572
573 /*
574 * AF_UNIX sockets do not interact with hardware, hence they
575 * dont trigger interrupts - so it's safe for them to have
576 * bh-unsafe locking for their sk_receive_queue.lock. Split off
577 * this special lock-class by reinitializing the spinlock key:
578 */
579 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
580
581 static struct sock * unix_create1(struct net *net, struct socket *sock)
582 {
583 struct sock *sk = NULL;
584 struct unix_sock *u;
585
586 atomic_inc(&unix_nr_socks);
587 if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
588 goto out;
589
590 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
591 if (!sk)
592 goto out;
593
594 sock_init_data(sock,sk);
595 lockdep_set_class(&sk->sk_receive_queue.lock,
596 &af_unix_sk_receive_queue_lock_key);
597
598 sk->sk_write_space = unix_write_space;
599 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
600 sk->sk_destruct = unix_sock_destructor;
601 u = unix_sk(sk);
602 u->dentry = NULL;
603 u->mnt = NULL;
604 spin_lock_init(&u->lock);
605 atomic_long_set(&u->inflight, 0);
606 INIT_LIST_HEAD(&u->link);
607 mutex_init(&u->readlock); /* single task reading lock */
608 init_waitqueue_head(&u->peer_wait);
609 unix_insert_socket(unix_sockets_unbound, sk);
610 out:
611 if (sk == NULL)
612 atomic_dec(&unix_nr_socks);
613 return sk;
614 }
615
616 static int unix_create(struct net *net, struct socket *sock, int protocol)
617 {
618 if (protocol && protocol != PF_UNIX)
619 return -EPROTONOSUPPORT;
620
621 sock->state = SS_UNCONNECTED;
622
623 switch (sock->type) {
624 case SOCK_STREAM:
625 sock->ops = &unix_stream_ops;
626 break;
627 /*
628 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
629 * nothing uses it.
630 */
631 case SOCK_RAW:
632 sock->type=SOCK_DGRAM;
633 case SOCK_DGRAM:
634 sock->ops = &unix_dgram_ops;
635 break;
636 case SOCK_SEQPACKET:
637 sock->ops = &unix_seqpacket_ops;
638 break;
639 default:
640 return -ESOCKTNOSUPPORT;
641 }
642
643 return unix_create1(net, sock) ? 0 : -ENOMEM;
644 }
645
646 static int unix_release(struct socket *sock)
647 {
648 struct sock *sk = sock->sk;
649
650 if (!sk)
651 return 0;
652
653 sock->sk = NULL;
654
655 return unix_release_sock (sk, 0);
656 }
657
658 static int unix_autobind(struct socket *sock)
659 {
660 struct sock *sk = sock->sk;
661 struct net *net = sock_net(sk);
662 struct unix_sock *u = unix_sk(sk);
663 static u32 ordernum = 1;
664 struct unix_address * addr;
665 int err;
666
667 mutex_lock(&u->readlock);
668
669 err = 0;
670 if (u->addr)
671 goto out;
672
673 err = -ENOMEM;
674 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
675 if (!addr)
676 goto out;
677
678 addr->name->sun_family = AF_UNIX;
679 atomic_set(&addr->refcnt, 1);
680
681 retry:
682 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
683 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
684
685 spin_lock(&unix_table_lock);
686 ordernum = (ordernum+1)&0xFFFFF;
687
688 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
689 addr->hash)) {
690 spin_unlock(&unix_table_lock);
691 /* Sanity yield. It is unusual case, but yet... */
692 if (!(ordernum&0xFF))
693 yield();
694 goto retry;
695 }
696 addr->hash ^= sk->sk_type;
697
698 __unix_remove_socket(sk);
699 u->addr = addr;
700 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
701 spin_unlock(&unix_table_lock);
702 err = 0;
703
704 out: mutex_unlock(&u->readlock);
705 return err;
706 }
707
708 static struct sock *unix_find_other(struct net *net,
709 struct sockaddr_un *sunname, int len,
710 int type, unsigned hash, int *error)
711 {
712 struct sock *u;
713 struct path path;
714 int err = 0;
715
716 if (sunname->sun_path[0]) {
717 struct inode *inode;
718 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
719 if (err)
720 goto fail;
721 inode = path.dentry->d_inode;
722 err = inode_permission(inode, MAY_WRITE);
723 if (err)
724 goto put_fail;
725
726 err = -ECONNREFUSED;
727 if (!S_ISSOCK(inode->i_mode))
728 goto put_fail;
729 u = unix_find_socket_byinode(net, inode);
730 if (!u)
731 goto put_fail;
732
733 if (u->sk_type == type)
734 touch_atime(path.mnt, path.dentry);
735
736 path_put(&path);
737
738 err=-EPROTOTYPE;
739 if (u->sk_type != type) {
740 sock_put(u);
741 goto fail;
742 }
743 } else {
744 err = -ECONNREFUSED;
745 u=unix_find_socket_byname(net, sunname, len, type, hash);
746 if (u) {
747 struct dentry *dentry;
748 dentry = unix_sk(u)->dentry;
749 if (dentry)
750 touch_atime(unix_sk(u)->mnt, dentry);
751 } else
752 goto fail;
753 }
754 return u;
755
756 put_fail:
757 path_put(&path);
758 fail:
759 *error=err;
760 return NULL;
761 }
762
763
764 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
765 {
766 struct sock *sk = sock->sk;
767 struct net *net = sock_net(sk);
768 struct unix_sock *u = unix_sk(sk);
769 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
770 struct dentry * dentry = NULL;
771 struct nameidata nd;
772 int err;
773 unsigned hash;
774 struct unix_address *addr;
775 struct hlist_head *list;
776
777 err = -EINVAL;
778 if (sunaddr->sun_family != AF_UNIX)
779 goto out;
780
781 if (addr_len==sizeof(short)) {
782 err = unix_autobind(sock);
783 goto out;
784 }
785
786 err = unix_mkname(sunaddr, addr_len, &hash);
787 if (err < 0)
788 goto out;
789 addr_len = err;
790
791 mutex_lock(&u->readlock);
792
793 err = -EINVAL;
794 if (u->addr)
795 goto out_up;
796
797 err = -ENOMEM;
798 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
799 if (!addr)
800 goto out_up;
801
802 memcpy(addr->name, sunaddr, addr_len);
803 addr->len = addr_len;
804 addr->hash = hash ^ sk->sk_type;
805 atomic_set(&addr->refcnt, 1);
806
807 if (sunaddr->sun_path[0]) {
808 unsigned int mode;
809 err = 0;
810 /*
811 * Get the parent directory, calculate the hash for last
812 * component.
813 */
814 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
815 if (err)
816 goto out_mknod_parent;
817
818 dentry = lookup_create(&nd, 0);
819 err = PTR_ERR(dentry);
820 if (IS_ERR(dentry))
821 goto out_mknod_unlock;
822
823 /*
824 * All right, let's create it.
825 */
826 mode = S_IFSOCK |
827 (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
828 err = mnt_want_write(nd.path.mnt);
829 if (err)
830 goto out_mknod_dput;
831 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
832 mnt_drop_write(nd.path.mnt);
833 if (err)
834 goto out_mknod_dput;
835 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
836 dput(nd.path.dentry);
837 nd.path.dentry = dentry;
838
839 addr->hash = UNIX_HASH_SIZE;
840 }
841
842 spin_lock(&unix_table_lock);
843
844 if (!sunaddr->sun_path[0]) {
845 err = -EADDRINUSE;
846 if (__unix_find_socket_byname(net, sunaddr, addr_len,
847 sk->sk_type, hash)) {
848 unix_release_addr(addr);
849 goto out_unlock;
850 }
851
852 list = &unix_socket_table[addr->hash];
853 } else {
854 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
855 u->dentry = nd.path.dentry;
856 u->mnt = nd.path.mnt;
857 }
858
859 err = 0;
860 __unix_remove_socket(sk);
861 u->addr = addr;
862 __unix_insert_socket(list, sk);
863
864 out_unlock:
865 spin_unlock(&unix_table_lock);
866 out_up:
867 mutex_unlock(&u->readlock);
868 out:
869 return err;
870
871 out_mknod_dput:
872 dput(dentry);
873 out_mknod_unlock:
874 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
875 path_put(&nd.path);
876 out_mknod_parent:
877 if (err==-EEXIST)
878 err=-EADDRINUSE;
879 unix_release_addr(addr);
880 goto out_up;
881 }
882
883 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
884 {
885 if (unlikely(sk1 == sk2) || !sk2) {
886 unix_state_lock(sk1);
887 return;
888 }
889 if (sk1 < sk2) {
890 unix_state_lock(sk1);
891 unix_state_lock_nested(sk2);
892 } else {
893 unix_state_lock(sk2);
894 unix_state_lock_nested(sk1);
895 }
896 }
897
898 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
899 {
900 if (unlikely(sk1 == sk2) || !sk2) {
901 unix_state_unlock(sk1);
902 return;
903 }
904 unix_state_unlock(sk1);
905 unix_state_unlock(sk2);
906 }
907
908 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
909 int alen, int flags)
910 {
911 struct sock *sk = sock->sk;
912 struct net *net = sock_net(sk);
913 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
914 struct sock *other;
915 unsigned hash;
916 int err;
917
918 if (addr->sa_family != AF_UNSPEC) {
919 err = unix_mkname(sunaddr, alen, &hash);
920 if (err < 0)
921 goto out;
922 alen = err;
923
924 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
925 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
926 goto out;
927
928 restart:
929 other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
930 if (!other)
931 goto out;
932
933 unix_state_double_lock(sk, other);
934
935 /* Apparently VFS overslept socket death. Retry. */
936 if (sock_flag(other, SOCK_DEAD)) {
937 unix_state_double_unlock(sk, other);
938 sock_put(other);
939 goto restart;
940 }
941
942 err = -EPERM;
943 if (!unix_may_send(sk, other))
944 goto out_unlock;
945
946 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
947 if (err)
948 goto out_unlock;
949
950 } else {
951 /*
952 * 1003.1g breaking connected state with AF_UNSPEC
953 */
954 other = NULL;
955 unix_state_double_lock(sk, other);
956 }
957
958 /*
959 * If it was connected, reconnect.
960 */
961 if (unix_peer(sk)) {
962 struct sock *old_peer = unix_peer(sk);
963 unix_peer(sk)=other;
964 unix_state_double_unlock(sk, other);
965
966 if (other != old_peer)
967 unix_dgram_disconnected(sk, old_peer);
968 sock_put(old_peer);
969 } else {
970 unix_peer(sk)=other;
971 unix_state_double_unlock(sk, other);
972 }
973 return 0;
974
975 out_unlock:
976 unix_state_double_unlock(sk, other);
977 sock_put(other);
978 out:
979 return err;
980 }
981
982 static long unix_wait_for_peer(struct sock *other, long timeo)
983 {
984 struct unix_sock *u = unix_sk(other);
985 int sched;
986 DEFINE_WAIT(wait);
987
988 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
989
990 sched = !sock_flag(other, SOCK_DEAD) &&
991 !(other->sk_shutdown & RCV_SHUTDOWN) &&
992 unix_recvq_full(other);
993
994 unix_state_unlock(other);
995
996 if (sched)
997 timeo = schedule_timeout(timeo);
998
999 finish_wait(&u->peer_wait, &wait);
1000 return timeo;
1001 }
1002
1003 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1004 int addr_len, int flags)
1005 {
1006 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1007 struct sock *sk = sock->sk;
1008 struct net *net = sock_net(sk);
1009 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1010 struct sock *newsk = NULL;
1011 struct sock *other = NULL;
1012 struct sk_buff *skb = NULL;
1013 unsigned hash;
1014 int st;
1015 int err;
1016 long timeo;
1017
1018 err = unix_mkname(sunaddr, addr_len, &hash);
1019 if (err < 0)
1020 goto out;
1021 addr_len = err;
1022
1023 if (test_bit(SOCK_PASSCRED, &sock->flags)
1024 && !u->addr && (err = unix_autobind(sock)) != 0)
1025 goto out;
1026
1027 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1028
1029 /* First of all allocate resources.
1030 If we will make it after state is locked,
1031 we will have to recheck all again in any case.
1032 */
1033
1034 err = -ENOMEM;
1035
1036 /* create new sock for complete connection */
1037 newsk = unix_create1(sock_net(sk), NULL);
1038 if (newsk == NULL)
1039 goto out;
1040
1041 /* Allocate skb for sending to listening sock */
1042 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1043 if (skb == NULL)
1044 goto out;
1045
1046 restart:
1047 /* Find listening sock. */
1048 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1049 if (!other)
1050 goto out;
1051
1052 /* Latch state of peer */
1053 unix_state_lock(other);
1054
1055 /* Apparently VFS overslept socket death. Retry. */
1056 if (sock_flag(other, SOCK_DEAD)) {
1057 unix_state_unlock(other);
1058 sock_put(other);
1059 goto restart;
1060 }
1061
1062 err = -ECONNREFUSED;
1063 if (other->sk_state != TCP_LISTEN)
1064 goto out_unlock;
1065
1066 if (unix_recvq_full(other)) {
1067 err = -EAGAIN;
1068 if (!timeo)
1069 goto out_unlock;
1070
1071 timeo = unix_wait_for_peer(other, timeo);
1072
1073 err = sock_intr_errno(timeo);
1074 if (signal_pending(current))
1075 goto out;
1076 sock_put(other);
1077 goto restart;
1078 }
1079
1080 /* Latch our state.
1081
1082 It is tricky place. We need to grab write lock and cannot
1083 drop lock on peer. It is dangerous because deadlock is
1084 possible. Connect to self case and simultaneous
1085 attempt to connect are eliminated by checking socket
1086 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1087 check this before attempt to grab lock.
1088
1089 Well, and we have to recheck the state after socket locked.
1090 */
1091 st = sk->sk_state;
1092
1093 switch (st) {
1094 case TCP_CLOSE:
1095 /* This is ok... continue with connect */
1096 break;
1097 case TCP_ESTABLISHED:
1098 /* Socket is already connected */
1099 err = -EISCONN;
1100 goto out_unlock;
1101 default:
1102 err = -EINVAL;
1103 goto out_unlock;
1104 }
1105
1106 unix_state_lock_nested(sk);
1107
1108 if (sk->sk_state != st) {
1109 unix_state_unlock(sk);
1110 unix_state_unlock(other);
1111 sock_put(other);
1112 goto restart;
1113 }
1114
1115 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1116 if (err) {
1117 unix_state_unlock(sk);
1118 goto out_unlock;
1119 }
1120
1121 /* The way is open! Fastly set all the necessary fields... */
1122
1123 sock_hold(sk);
1124 unix_peer(newsk) = sk;
1125 newsk->sk_state = TCP_ESTABLISHED;
1126 newsk->sk_type = sk->sk_type;
1127 newsk->sk_peercred.pid = task_tgid_vnr(current);
1128 current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid);
1129 newu = unix_sk(newsk);
1130 newsk->sk_sleep = &newu->peer_wait;
1131 otheru = unix_sk(other);
1132
1133 /* copy address information from listening to new sock*/
1134 if (otheru->addr) {
1135 atomic_inc(&otheru->addr->refcnt);
1136 newu->addr = otheru->addr;
1137 }
1138 if (otheru->dentry) {
1139 newu->dentry = dget(otheru->dentry);
1140 newu->mnt = mntget(otheru->mnt);
1141 }
1142
1143 /* Set credentials */
1144 sk->sk_peercred = other->sk_peercred;
1145
1146 sock->state = SS_CONNECTED;
1147 sk->sk_state = TCP_ESTABLISHED;
1148 sock_hold(newsk);
1149
1150 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1151 unix_peer(sk) = newsk;
1152
1153 unix_state_unlock(sk);
1154
1155 /* take ten and and send info to listening sock */
1156 spin_lock(&other->sk_receive_queue.lock);
1157 __skb_queue_tail(&other->sk_receive_queue, skb);
1158 spin_unlock(&other->sk_receive_queue.lock);
1159 unix_state_unlock(other);
1160 other->sk_data_ready(other, 0);
1161 sock_put(other);
1162 return 0;
1163
1164 out_unlock:
1165 if (other)
1166 unix_state_unlock(other);
1167
1168 out:
1169 if (skb)
1170 kfree_skb(skb);
1171 if (newsk)
1172 unix_release_sock(newsk, 0);
1173 if (other)
1174 sock_put(other);
1175 return err;
1176 }
1177
1178 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1179 {
1180 struct sock *ska=socka->sk, *skb = sockb->sk;
1181
1182 /* Join our sockets back to back */
1183 sock_hold(ska);
1184 sock_hold(skb);
1185 unix_peer(ska)=skb;
1186 unix_peer(skb)=ska;
1187 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
1188 current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid);
1189 ska->sk_peercred.uid = skb->sk_peercred.uid;
1190 ska->sk_peercred.gid = skb->sk_peercred.gid;
1191
1192 if (ska->sk_type != SOCK_DGRAM) {
1193 ska->sk_state = TCP_ESTABLISHED;
1194 skb->sk_state = TCP_ESTABLISHED;
1195 socka->state = SS_CONNECTED;
1196 sockb->state = SS_CONNECTED;
1197 }
1198 return 0;
1199 }
1200
1201 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1202 {
1203 struct sock *sk = sock->sk;
1204 struct sock *tsk;
1205 struct sk_buff *skb;
1206 int err;
1207
1208 err = -EOPNOTSUPP;
1209 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1210 goto out;
1211
1212 err = -EINVAL;
1213 if (sk->sk_state != TCP_LISTEN)
1214 goto out;
1215
1216 /* If socket state is TCP_LISTEN it cannot change (for now...),
1217 * so that no locks are necessary.
1218 */
1219
1220 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1221 if (!skb) {
1222 /* This means receive shutdown. */
1223 if (err == 0)
1224 err = -EINVAL;
1225 goto out;
1226 }
1227
1228 tsk = skb->sk;
1229 skb_free_datagram(sk, skb);
1230 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1231
1232 /* attach accepted sock to socket */
1233 unix_state_lock(tsk);
1234 newsock->state = SS_CONNECTED;
1235 sock_graft(tsk, newsock);
1236 unix_state_unlock(tsk);
1237 return 0;
1238
1239 out:
1240 return err;
1241 }
1242
1243
1244 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1245 {
1246 struct sock *sk = sock->sk;
1247 struct unix_sock *u;
1248 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1249 int err = 0;
1250
1251 if (peer) {
1252 sk = unix_peer_get(sk);
1253
1254 err = -ENOTCONN;
1255 if (!sk)
1256 goto out;
1257 err = 0;
1258 } else {
1259 sock_hold(sk);
1260 }
1261
1262 u = unix_sk(sk);
1263 unix_state_lock(sk);
1264 if (!u->addr) {
1265 sunaddr->sun_family = AF_UNIX;
1266 sunaddr->sun_path[0] = 0;
1267 *uaddr_len = sizeof(short);
1268 } else {
1269 struct unix_address *addr = u->addr;
1270
1271 *uaddr_len = addr->len;
1272 memcpy(sunaddr, addr->name, *uaddr_len);
1273 }
1274 unix_state_unlock(sk);
1275 sock_put(sk);
1276 out:
1277 return err;
1278 }
1279
1280 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1281 {
1282 int i;
1283
1284 scm->fp = UNIXCB(skb).fp;
1285 skb->destructor = sock_wfree;
1286 UNIXCB(skb).fp = NULL;
1287
1288 for (i=scm->fp->count-1; i>=0; i--)
1289 unix_notinflight(scm->fp->fp[i]);
1290 }
1291
1292 static void unix_destruct_fds(struct sk_buff *skb)
1293 {
1294 struct scm_cookie scm;
1295 memset(&scm, 0, sizeof(scm));
1296 unix_detach_fds(&scm, skb);
1297
1298 /* Alas, it calls VFS */
1299 /* So fscking what? fput() had been SMP-safe since the last Summer */
1300 scm_destroy(&scm);
1301 sock_wfree(skb);
1302 }
1303
1304 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1305 {
1306 int i;
1307 for (i=scm->fp->count-1; i>=0; i--)
1308 unix_inflight(scm->fp->fp[i]);
1309 UNIXCB(skb).fp = scm->fp;
1310 skb->destructor = unix_destruct_fds;
1311 scm->fp = NULL;
1312 }
1313
1314 /*
1315 * Send AF_UNIX data.
1316 */
1317
1318 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1319 struct msghdr *msg, size_t len)
1320 {
1321 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1322 struct sock *sk = sock->sk;
1323 struct net *net = sock_net(sk);
1324 struct unix_sock *u = unix_sk(sk);
1325 struct sockaddr_un *sunaddr=msg->msg_name;
1326 struct sock *other = NULL;
1327 int namelen = 0; /* fake GCC */
1328 int err;
1329 unsigned hash;
1330 struct sk_buff *skb;
1331 long timeo;
1332 struct scm_cookie tmp_scm;
1333
1334 if (NULL == siocb->scm)
1335 siocb->scm = &tmp_scm;
1336 err = scm_send(sock, msg, siocb->scm);
1337 if (err < 0)
1338 return err;
1339
1340 err = -EOPNOTSUPP;
1341 if (msg->msg_flags&MSG_OOB)
1342 goto out;
1343
1344 if (msg->msg_namelen) {
1345 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1346 if (err < 0)
1347 goto out;
1348 namelen = err;
1349 } else {
1350 sunaddr = NULL;
1351 err = -ENOTCONN;
1352 other = unix_peer_get(sk);
1353 if (!other)
1354 goto out;
1355 }
1356
1357 if (test_bit(SOCK_PASSCRED, &sock->flags)
1358 && !u->addr && (err = unix_autobind(sock)) != 0)
1359 goto out;
1360
1361 err = -EMSGSIZE;
1362 if (len > sk->sk_sndbuf - 32)
1363 goto out;
1364
1365 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1366 if (skb==NULL)
1367 goto out;
1368
1369 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1370 if (siocb->scm->fp)
1371 unix_attach_fds(siocb->scm, skb);
1372 unix_get_secdata(siocb->scm, skb);
1373
1374 skb_reset_transport_header(skb);
1375 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1376 if (err)
1377 goto out_free;
1378
1379 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1380
1381 restart:
1382 if (!other) {
1383 err = -ECONNRESET;
1384 if (sunaddr == NULL)
1385 goto out_free;
1386
1387 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1388 hash, &err);
1389 if (other==NULL)
1390 goto out_free;
1391 }
1392
1393 unix_state_lock(other);
1394 err = -EPERM;
1395 if (!unix_may_send(sk, other))
1396 goto out_unlock;
1397
1398 if (sock_flag(other, SOCK_DEAD)) {
1399 /*
1400 * Check with 1003.1g - what should
1401 * datagram error
1402 */
1403 unix_state_unlock(other);
1404 sock_put(other);
1405
1406 err = 0;
1407 unix_state_lock(sk);
1408 if (unix_peer(sk) == other) {
1409 unix_peer(sk)=NULL;
1410 unix_state_unlock(sk);
1411
1412 unix_dgram_disconnected(sk, other);
1413 sock_put(other);
1414 err = -ECONNREFUSED;
1415 } else {
1416 unix_state_unlock(sk);
1417 }
1418
1419 other = NULL;
1420 if (err)
1421 goto out_free;
1422 goto restart;
1423 }
1424
1425 err = -EPIPE;
1426 if (other->sk_shutdown & RCV_SHUTDOWN)
1427 goto out_unlock;
1428
1429 if (sk->sk_type != SOCK_SEQPACKET) {
1430 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1431 if (err)
1432 goto out_unlock;
1433 }
1434
1435 if (unix_peer(other) != sk && unix_recvq_full(other)) {
1436 if (!timeo) {
1437 err = -EAGAIN;
1438 goto out_unlock;
1439 }
1440
1441 timeo = unix_wait_for_peer(other, timeo);
1442
1443 err = sock_intr_errno(timeo);
1444 if (signal_pending(current))
1445 goto out_free;
1446
1447 goto restart;
1448 }
1449
1450 skb_queue_tail(&other->sk_receive_queue, skb);
1451 unix_state_unlock(other);
1452 other->sk_data_ready(other, len);
1453 sock_put(other);
1454 scm_destroy(siocb->scm);
1455 return len;
1456
1457 out_unlock:
1458 unix_state_unlock(other);
1459 out_free:
1460 kfree_skb(skb);
1461 out:
1462 if (other)
1463 sock_put(other);
1464 scm_destroy(siocb->scm);
1465 return err;
1466 }
1467
1468
1469 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1470 struct msghdr *msg, size_t len)
1471 {
1472 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1473 struct sock *sk = sock->sk;
1474 struct sock *other = NULL;
1475 struct sockaddr_un *sunaddr=msg->msg_name;
1476 int err,size;
1477 struct sk_buff *skb;
1478 int sent=0;
1479 struct scm_cookie tmp_scm;
1480
1481 if (NULL == siocb->scm)
1482 siocb->scm = &tmp_scm;
1483 err = scm_send(sock, msg, siocb->scm);
1484 if (err < 0)
1485 return err;
1486
1487 err = -EOPNOTSUPP;
1488 if (msg->msg_flags&MSG_OOB)
1489 goto out_err;
1490
1491 if (msg->msg_namelen) {
1492 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1493 goto out_err;
1494 } else {
1495 sunaddr = NULL;
1496 err = -ENOTCONN;
1497 other = unix_peer(sk);
1498 if (!other)
1499 goto out_err;
1500 }
1501
1502 if (sk->sk_shutdown & SEND_SHUTDOWN)
1503 goto pipe_err;
1504
1505 while(sent < len)
1506 {
1507 /*
1508 * Optimisation for the fact that under 0.01% of X
1509 * messages typically need breaking up.
1510 */
1511
1512 size = len-sent;
1513
1514 /* Keep two messages in the pipe so it schedules better */
1515 if (size > ((sk->sk_sndbuf >> 1) - 64))
1516 size = (sk->sk_sndbuf >> 1) - 64;
1517
1518 if (size > SKB_MAX_ALLOC)
1519 size = SKB_MAX_ALLOC;
1520
1521 /*
1522 * Grab a buffer
1523 */
1524
1525 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1526
1527 if (skb==NULL)
1528 goto out_err;
1529
1530 /*
1531 * If you pass two values to the sock_alloc_send_skb
1532 * it tries to grab the large buffer with GFP_NOFS
1533 * (which can fail easily), and if it fails grab the
1534 * fallback size buffer which is under a page and will
1535 * succeed. [Alan]
1536 */
1537 size = min_t(int, size, skb_tailroom(skb));
1538
1539 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1540 if (siocb->scm->fp)
1541 unix_attach_fds(siocb->scm, skb);
1542
1543 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1544 kfree_skb(skb);
1545 goto out_err;
1546 }
1547
1548 unix_state_lock(other);
1549
1550 if (sock_flag(other, SOCK_DEAD) ||
1551 (other->sk_shutdown & RCV_SHUTDOWN))
1552 goto pipe_err_free;
1553
1554 skb_queue_tail(&other->sk_receive_queue, skb);
1555 unix_state_unlock(other);
1556 other->sk_data_ready(other, size);
1557 sent+=size;
1558 }
1559
1560 scm_destroy(siocb->scm);
1561 siocb->scm = NULL;
1562
1563 return sent;
1564
1565 pipe_err_free:
1566 unix_state_unlock(other);
1567 kfree_skb(skb);
1568 pipe_err:
1569 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1570 send_sig(SIGPIPE,current,0);
1571 err = -EPIPE;
1572 out_err:
1573 scm_destroy(siocb->scm);
1574 siocb->scm = NULL;
1575 return sent ? : err;
1576 }
1577
1578 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1579 struct msghdr *msg, size_t len)
1580 {
1581 int err;
1582 struct sock *sk = sock->sk;
1583
1584 err = sock_error(sk);
1585 if (err)
1586 return err;
1587
1588 if (sk->sk_state != TCP_ESTABLISHED)
1589 return -ENOTCONN;
1590
1591 if (msg->msg_namelen)
1592 msg->msg_namelen = 0;
1593
1594 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1595 }
1596
1597 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1598 {
1599 struct unix_sock *u = unix_sk(sk);
1600
1601 msg->msg_namelen = 0;
1602 if (u->addr) {
1603 msg->msg_namelen = u->addr->len;
1604 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1605 }
1606 }
1607
1608 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1609 struct msghdr *msg, size_t size,
1610 int flags)
1611 {
1612 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1613 struct scm_cookie tmp_scm;
1614 struct sock *sk = sock->sk;
1615 struct unix_sock *u = unix_sk(sk);
1616 int noblock = flags & MSG_DONTWAIT;
1617 struct sk_buff *skb;
1618 int err;
1619
1620 err = -EOPNOTSUPP;
1621 if (flags&MSG_OOB)
1622 goto out;
1623
1624 msg->msg_namelen = 0;
1625
1626 mutex_lock(&u->readlock);
1627
1628 skb = skb_recv_datagram(sk, flags, noblock, &err);
1629 if (!skb) {
1630 unix_state_lock(sk);
1631 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1632 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1633 (sk->sk_shutdown & RCV_SHUTDOWN))
1634 err = 0;
1635 unix_state_unlock(sk);
1636 goto out_unlock;
1637 }
1638
1639 wake_up_interruptible_sync(&u->peer_wait);
1640
1641 if (msg->msg_name)
1642 unix_copy_addr(msg, skb->sk);
1643
1644 if (size > skb->len)
1645 size = skb->len;
1646 else if (size < skb->len)
1647 msg->msg_flags |= MSG_TRUNC;
1648
1649 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1650 if (err)
1651 goto out_free;
1652
1653 if (!siocb->scm) {
1654 siocb->scm = &tmp_scm;
1655 memset(&tmp_scm, 0, sizeof(tmp_scm));
1656 }
1657 siocb->scm->creds = *UNIXCREDS(skb);
1658 unix_set_secdata(siocb->scm, skb);
1659
1660 if (!(flags & MSG_PEEK))
1661 {
1662 if (UNIXCB(skb).fp)
1663 unix_detach_fds(siocb->scm, skb);
1664 }
1665 else
1666 {
1667 /* It is questionable: on PEEK we could:
1668 - do not return fds - good, but too simple 8)
1669 - return fds, and do not return them on read (old strategy,
1670 apparently wrong)
1671 - clone fds (I chose it for now, it is the most universal
1672 solution)
1673
1674 POSIX 1003.1g does not actually define this clearly
1675 at all. POSIX 1003.1g doesn't define a lot of things
1676 clearly however!
1677
1678 */
1679 if (UNIXCB(skb).fp)
1680 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1681 }
1682 err = size;
1683
1684 scm_recv(sock, msg, siocb->scm, flags);
1685
1686 out_free:
1687 skb_free_datagram(sk,skb);
1688 out_unlock:
1689 mutex_unlock(&u->readlock);
1690 out:
1691 return err;
1692 }
1693
1694 /*
1695 * Sleep until data has arrive. But check for races..
1696 */
1697
1698 static long unix_stream_data_wait(struct sock * sk, long timeo)
1699 {
1700 DEFINE_WAIT(wait);
1701
1702 unix_state_lock(sk);
1703
1704 for (;;) {
1705 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1706
1707 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1708 sk->sk_err ||
1709 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1710 signal_pending(current) ||
1711 !timeo)
1712 break;
1713
1714 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1715 unix_state_unlock(sk);
1716 timeo = schedule_timeout(timeo);
1717 unix_state_lock(sk);
1718 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1719 }
1720
1721 finish_wait(sk->sk_sleep, &wait);
1722 unix_state_unlock(sk);
1723 return timeo;
1724 }
1725
1726
1727
1728 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1729 struct msghdr *msg, size_t size,
1730 int flags)
1731 {
1732 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1733 struct scm_cookie tmp_scm;
1734 struct sock *sk = sock->sk;
1735 struct unix_sock *u = unix_sk(sk);
1736 struct sockaddr_un *sunaddr=msg->msg_name;
1737 int copied = 0;
1738 int check_creds = 0;
1739 int target;
1740 int err = 0;
1741 long timeo;
1742
1743 err = -EINVAL;
1744 if (sk->sk_state != TCP_ESTABLISHED)
1745 goto out;
1746
1747 err = -EOPNOTSUPP;
1748 if (flags&MSG_OOB)
1749 goto out;
1750
1751 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1752 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1753
1754 msg->msg_namelen = 0;
1755
1756 /* Lock the socket to prevent queue disordering
1757 * while sleeps in memcpy_tomsg
1758 */
1759
1760 if (!siocb->scm) {
1761 siocb->scm = &tmp_scm;
1762 memset(&tmp_scm, 0, sizeof(tmp_scm));
1763 }
1764
1765 mutex_lock(&u->readlock);
1766
1767 do
1768 {
1769 int chunk;
1770 struct sk_buff *skb;
1771
1772 unix_state_lock(sk);
1773 skb = skb_dequeue(&sk->sk_receive_queue);
1774 if (skb==NULL)
1775 {
1776 if (copied >= target)
1777 goto unlock;
1778
1779 /*
1780 * POSIX 1003.1g mandates this order.
1781 */
1782
1783 if ((err = sock_error(sk)) != 0)
1784 goto unlock;
1785 if (sk->sk_shutdown & RCV_SHUTDOWN)
1786 goto unlock;
1787
1788 unix_state_unlock(sk);
1789 err = -EAGAIN;
1790 if (!timeo)
1791 break;
1792 mutex_unlock(&u->readlock);
1793
1794 timeo = unix_stream_data_wait(sk, timeo);
1795
1796 if (signal_pending(current)) {
1797 err = sock_intr_errno(timeo);
1798 goto out;
1799 }
1800 mutex_lock(&u->readlock);
1801 continue;
1802 unlock:
1803 unix_state_unlock(sk);
1804 break;
1805 }
1806 unix_state_unlock(sk);
1807
1808 if (check_creds) {
1809 /* Never glue messages from different writers */
1810 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1811 skb_queue_head(&sk->sk_receive_queue, skb);
1812 break;
1813 }
1814 } else {
1815 /* Copy credentials */
1816 siocb->scm->creds = *UNIXCREDS(skb);
1817 check_creds = 1;
1818 }
1819
1820 /* Copy address just once */
1821 if (sunaddr)
1822 {
1823 unix_copy_addr(msg, skb->sk);
1824 sunaddr = NULL;
1825 }
1826
1827 chunk = min_t(unsigned int, skb->len, size);
1828 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1829 skb_queue_head(&sk->sk_receive_queue, skb);
1830 if (copied == 0)
1831 copied = -EFAULT;
1832 break;
1833 }
1834 copied += chunk;
1835 size -= chunk;
1836
1837 /* Mark read part of skb as used */
1838 if (!(flags & MSG_PEEK))
1839 {
1840 skb_pull(skb, chunk);
1841
1842 if (UNIXCB(skb).fp)
1843 unix_detach_fds(siocb->scm, skb);
1844
1845 /* put the skb back if we didn't use it up.. */
1846 if (skb->len)
1847 {
1848 skb_queue_head(&sk->sk_receive_queue, skb);
1849 break;
1850 }
1851
1852 kfree_skb(skb);
1853
1854 if (siocb->scm->fp)
1855 break;
1856 }
1857 else
1858 {
1859 /* It is questionable, see note in unix_dgram_recvmsg.
1860 */
1861 if (UNIXCB(skb).fp)
1862 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1863
1864 /* put message back and return */
1865 skb_queue_head(&sk->sk_receive_queue, skb);
1866 break;
1867 }
1868 } while (size);
1869
1870 mutex_unlock(&u->readlock);
1871 scm_recv(sock, msg, siocb->scm, flags);
1872 out:
1873 return copied ? : err;
1874 }
1875
1876 static int unix_shutdown(struct socket *sock, int mode)
1877 {
1878 struct sock *sk = sock->sk;
1879 struct sock *other;
1880
1881 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1882
1883 if (mode) {
1884 unix_state_lock(sk);
1885 sk->sk_shutdown |= mode;
1886 other=unix_peer(sk);
1887 if (other)
1888 sock_hold(other);
1889 unix_state_unlock(sk);
1890 sk->sk_state_change(sk);
1891
1892 if (other &&
1893 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1894
1895 int peer_mode = 0;
1896
1897 if (mode&RCV_SHUTDOWN)
1898 peer_mode |= SEND_SHUTDOWN;
1899 if (mode&SEND_SHUTDOWN)
1900 peer_mode |= RCV_SHUTDOWN;
1901 unix_state_lock(other);
1902 other->sk_shutdown |= peer_mode;
1903 unix_state_unlock(other);
1904 other->sk_state_change(other);
1905 read_lock(&other->sk_callback_lock);
1906 if (peer_mode == SHUTDOWN_MASK)
1907 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
1908 else if (peer_mode & RCV_SHUTDOWN)
1909 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
1910 read_unlock(&other->sk_callback_lock);
1911 }
1912 if (other)
1913 sock_put(other);
1914 }
1915 return 0;
1916 }
1917
1918 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1919 {
1920 struct sock *sk = sock->sk;
1921 long amount=0;
1922 int err;
1923
1924 switch(cmd)
1925 {
1926 case SIOCOUTQ:
1927 amount = atomic_read(&sk->sk_wmem_alloc);
1928 err = put_user(amount, (int __user *)arg);
1929 break;
1930 case SIOCINQ:
1931 {
1932 struct sk_buff *skb;
1933
1934 if (sk->sk_state == TCP_LISTEN) {
1935 err = -EINVAL;
1936 break;
1937 }
1938
1939 spin_lock(&sk->sk_receive_queue.lock);
1940 if (sk->sk_type == SOCK_STREAM ||
1941 sk->sk_type == SOCK_SEQPACKET) {
1942 skb_queue_walk(&sk->sk_receive_queue, skb)
1943 amount += skb->len;
1944 } else {
1945 skb = skb_peek(&sk->sk_receive_queue);
1946 if (skb)
1947 amount=skb->len;
1948 }
1949 spin_unlock(&sk->sk_receive_queue.lock);
1950 err = put_user(amount, (int __user *)arg);
1951 break;
1952 }
1953
1954 default:
1955 err = -ENOIOCTLCMD;
1956 break;
1957 }
1958 return err;
1959 }
1960
1961 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1962 {
1963 struct sock *sk = sock->sk;
1964 unsigned int mask;
1965
1966 poll_wait(file, sk->sk_sleep, wait);
1967 mask = 0;
1968
1969 /* exceptional events? */
1970 if (sk->sk_err)
1971 mask |= POLLERR;
1972 if (sk->sk_shutdown == SHUTDOWN_MASK)
1973 mask |= POLLHUP;
1974 if (sk->sk_shutdown & RCV_SHUTDOWN)
1975 mask |= POLLRDHUP;
1976
1977 /* readable? */
1978 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1979 (sk->sk_shutdown & RCV_SHUTDOWN))
1980 mask |= POLLIN | POLLRDNORM;
1981
1982 /* Connection-based need to check for termination and startup */
1983 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
1984 mask |= POLLHUP;
1985
1986 /*
1987 * we set writable also when the other side has shut down the
1988 * connection. This prevents stuck sockets.
1989 */
1990 if (unix_writable(sk))
1991 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1992
1993 return mask;
1994 }
1995
1996 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
1997 poll_table *wait)
1998 {
1999 struct sock *sk = sock->sk, *other;
2000 unsigned int mask, writable;
2001
2002 poll_wait(file, sk->sk_sleep, wait);
2003 mask = 0;
2004
2005 /* exceptional events? */
2006 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2007 mask |= POLLERR;
2008 if (sk->sk_shutdown & RCV_SHUTDOWN)
2009 mask |= POLLRDHUP;
2010 if (sk->sk_shutdown == SHUTDOWN_MASK)
2011 mask |= POLLHUP;
2012
2013 /* readable? */
2014 if (!skb_queue_empty(&sk->sk_receive_queue) ||
2015 (sk->sk_shutdown & RCV_SHUTDOWN))
2016 mask |= POLLIN | POLLRDNORM;
2017
2018 /* Connection-based need to check for termination and startup */
2019 if (sk->sk_type == SOCK_SEQPACKET) {
2020 if (sk->sk_state == TCP_CLOSE)
2021 mask |= POLLHUP;
2022 /* connection hasn't started yet? */
2023 if (sk->sk_state == TCP_SYN_SENT)
2024 return mask;
2025 }
2026
2027 /* writable? */
2028 writable = unix_writable(sk);
2029 if (writable) {
2030 other = unix_peer_get(sk);
2031 if (other) {
2032 if (unix_peer(other) != sk) {
2033 poll_wait(file, &unix_sk(other)->peer_wait,
2034 wait);
2035 if (unix_recvq_full(other))
2036 writable = 0;
2037 }
2038
2039 sock_put(other);
2040 }
2041 }
2042
2043 if (writable)
2044 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2045 else
2046 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2047
2048 return mask;
2049 }
2050
2051 #ifdef CONFIG_PROC_FS
2052 static struct sock *first_unix_socket(int *i)
2053 {
2054 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
2055 if (!hlist_empty(&unix_socket_table[*i]))
2056 return __sk_head(&unix_socket_table[*i]);
2057 }
2058 return NULL;
2059 }
2060
2061 static struct sock *next_unix_socket(int *i, struct sock *s)
2062 {
2063 struct sock *next = sk_next(s);
2064 /* More in this chain? */
2065 if (next)
2066 return next;
2067 /* Look for next non-empty chain. */
2068 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
2069 if (!hlist_empty(&unix_socket_table[*i]))
2070 return __sk_head(&unix_socket_table[*i]);
2071 }
2072 return NULL;
2073 }
2074
2075 struct unix_iter_state {
2076 struct seq_net_private p;
2077 int i;
2078 };
2079 static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
2080 {
2081 struct unix_iter_state *iter = seq->private;
2082 loff_t off = 0;
2083 struct sock *s;
2084
2085 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
2086 if (sock_net(s) != seq_file_net(seq))
2087 continue;
2088 if (off == pos)
2089 return s;
2090 ++off;
2091 }
2092 return NULL;
2093 }
2094
2095
2096 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2097 __acquires(unix_table_lock)
2098 {
2099 spin_lock(&unix_table_lock);
2100 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2101 }
2102
2103 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2104 {
2105 struct unix_iter_state *iter = seq->private;
2106 struct sock *sk = v;
2107 ++*pos;
2108
2109 if (v == SEQ_START_TOKEN)
2110 sk = first_unix_socket(&iter->i);
2111 else
2112 sk = next_unix_socket(&iter->i, sk);
2113 while (sk && (sock_net(sk) != seq_file_net(seq)))
2114 sk = next_unix_socket(&iter->i, sk);
2115 return sk;
2116 }
2117
2118 static void unix_seq_stop(struct seq_file *seq, void *v)
2119 __releases(unix_table_lock)
2120 {
2121 spin_unlock(&unix_table_lock);
2122 }
2123
2124 static int unix_seq_show(struct seq_file *seq, void *v)
2125 {
2126
2127 if (v == SEQ_START_TOKEN)
2128 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2129 "Inode Path\n");
2130 else {
2131 struct sock *s = v;
2132 struct unix_sock *u = unix_sk(s);
2133 unix_state_lock(s);
2134
2135 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2136 s,
2137 atomic_read(&s->sk_refcnt),
2138 0,
2139 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2140 s->sk_type,
2141 s->sk_socket ?
2142 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2143 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2144 sock_i_ino(s));
2145
2146 if (u->addr) {
2147 int i, len;
2148 seq_putc(seq, ' ');
2149
2150 i = 0;
2151 len = u->addr->len - sizeof(short);
2152 if (!UNIX_ABSTRACT(s))
2153 len--;
2154 else {
2155 seq_putc(seq, '@');
2156 i++;
2157 }
2158 for ( ; i < len; i++)
2159 seq_putc(seq, u->addr->name->sun_path[i]);
2160 }
2161 unix_state_unlock(s);
2162 seq_putc(seq, '\n');
2163 }
2164
2165 return 0;
2166 }
2167
2168 static const struct seq_operations unix_seq_ops = {
2169 .start = unix_seq_start,
2170 .next = unix_seq_next,
2171 .stop = unix_seq_stop,
2172 .show = unix_seq_show,
2173 };
2174
2175
2176 static int unix_seq_open(struct inode *inode, struct file *file)
2177 {
2178 return seq_open_net(inode, file, &unix_seq_ops,
2179 sizeof(struct unix_iter_state));
2180 }
2181
2182 static const struct file_operations unix_seq_fops = {
2183 .owner = THIS_MODULE,
2184 .open = unix_seq_open,
2185 .read = seq_read,
2186 .llseek = seq_lseek,
2187 .release = seq_release_net,
2188 };
2189
2190 #endif
2191
2192 static struct net_proto_family unix_family_ops = {
2193 .family = PF_UNIX,
2194 .create = unix_create,
2195 .owner = THIS_MODULE,
2196 };
2197
2198
2199 static int unix_net_init(struct net *net)
2200 {
2201 int error = -ENOMEM;
2202
2203 net->unx.sysctl_max_dgram_qlen = 10;
2204 if (unix_sysctl_register(net))
2205 goto out;
2206
2207 #ifdef CONFIG_PROC_FS
2208 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2209 unix_sysctl_unregister(net);
2210 goto out;
2211 }
2212 #endif
2213 error = 0;
2214 out:
2215 return error;
2216 }
2217
2218 static void unix_net_exit(struct net *net)
2219 {
2220 unix_sysctl_unregister(net);
2221 proc_net_remove(net, "unix");
2222 }
2223
2224 static struct pernet_operations unix_net_ops = {
2225 .init = unix_net_init,
2226 .exit = unix_net_exit,
2227 };
2228
2229 static int __init af_unix_init(void)
2230 {
2231 int rc = -1;
2232 struct sk_buff *dummy_skb;
2233
2234 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2235
2236 rc = proto_register(&unix_proto, 1);
2237 if (rc != 0) {
2238 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2239 __func__);
2240 goto out;
2241 }
2242
2243 sock_register(&unix_family_ops);
2244 register_pernet_subsys(&unix_net_ops);
2245 out:
2246 return rc;
2247 }
2248
2249 static void __exit af_unix_exit(void)
2250 {
2251 sock_unregister(PF_UNIX);
2252 proto_unregister(&unix_proto);
2253 unregister_pernet_subsys(&unix_net_ops);
2254 }
2255
2256 /* Earlier than device_initcall() so that other drivers invoking
2257 request_module() don't end up in a loop when modprobe tries
2258 to use a UNIX socket. But later than subsys_initcall() because
2259 we depend on stuff initialised there */
2260 fs_initcall(af_unix_init);
2261 module_exit(af_unix_exit);
2262
2263 MODULE_LICENSE("GPL");
2264 MODULE_ALIAS_NETPROTO(PF_UNIX);
Linus' kernel tree