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Linux v2.6.17-rc2
[linux-2.6/next.git] / net / unix / af_unix.c
blobd901465ce0135093276d55adabbb7691591097c3
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/config.h>
87 #include <linux/kernel.h>
88 #include <linux/signal.h>
89 #include <linux/sched.h>
90 #include <linux/errno.h>
91 #include <linux/string.h>
92 #include <linux/stat.h>
93 #include <linux/dcache.h>
94 #include <linux/namei.h>
95 #include <linux/socket.h>
96 #include <linux/un.h>
97 #include <linux/fcntl.h>
98 #include <linux/termios.h>
99 #include <linux/sockios.h>
100 #include <linux/net.h>
101 #include <linux/in.h>
102 #include <linux/fs.h>
103 #include <linux/slab.h>
104 #include <asm/uaccess.h>
105 #include <linux/skbuff.h>
106 #include <linux/netdevice.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/smp_lock.h>
116 #include <linux/rtnetlink.h>
117 #include <linux/mount.h>
118 #include <net/checksum.h>
119 #include <linux/security.h>
120
121 int sysctl_unix_max_dgram_qlen = 10;
122
123 struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
124 DEFINE_SPINLOCK(unix_table_lock);
125 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
126
127 #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
128
129 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
130
131 /*
132 * SMP locking strategy:
133 * hash table is protected with spinlock unix_table_lock
134 * each socket state is protected by separate rwlock.
135 */
136
137 static inline unsigned unix_hash_fold(unsigned hash)
138 {
139 hash ^= hash>>16;
140 hash ^= hash>>8;
141 return hash&(UNIX_HASH_SIZE-1);
142 }
143
144 #define unix_peer(sk) (unix_sk(sk)->peer)
145
146 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
147 {
148 return unix_peer(osk) == sk;
149 }
150
151 static inline int unix_may_send(struct sock *sk, struct sock *osk)
152 {
153 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
154 }
155
156 static struct sock *unix_peer_get(struct sock *s)
157 {
158 struct sock *peer;
159
160 unix_state_rlock(s);
161 peer = unix_peer(s);
162 if (peer)
163 sock_hold(peer);
164 unix_state_runlock(s);
165 return peer;
166 }
167
168 static inline void unix_release_addr(struct unix_address *addr)
169 {
170 if (atomic_dec_and_test(&addr->refcnt))
171 kfree(addr);
172 }
173
174 /*
175 * Check unix socket name:
176 * - should be not zero length.
177 * - if started by not zero, should be NULL terminated (FS object)
178 * - if started by zero, it is abstract name.
179 */
180
181 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
182 {
183 if (len <= sizeof(short) || len > sizeof(*sunaddr))
184 return -EINVAL;
185 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
186 return -EINVAL;
187 if (sunaddr->sun_path[0]) {
188 /*
189 * This may look like an off by one error but it is a bit more
190 * subtle. 108 is the longest valid AF_UNIX path for a binding.
191 * sun_path[108] doesnt as such exist. However in kernel space
192 * we are guaranteed that it is a valid memory location in our
193 * kernel address buffer.
194 */
195 ((char *)sunaddr)[len]=0;
196 len = strlen(sunaddr->sun_path)+1+sizeof(short);
197 return len;
198 }
199
200 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
201 return len;
202 }
203
204 static void __unix_remove_socket(struct sock *sk)
205 {
206 sk_del_node_init(sk);
207 }
208
209 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
210 {
211 BUG_TRAP(sk_unhashed(sk));
212 sk_add_node(sk, list);
213 }
214
215 static inline void unix_remove_socket(struct sock *sk)
216 {
217 spin_lock(&unix_table_lock);
218 __unix_remove_socket(sk);
219 spin_unlock(&unix_table_lock);
220 }
221
222 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
223 {
224 spin_lock(&unix_table_lock);
225 __unix_insert_socket(list, sk);
226 spin_unlock(&unix_table_lock);
227 }
228
229 static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname,
230 int len, int type, unsigned hash)
231 {
232 struct sock *s;
233 struct hlist_node *node;
234
235 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
236 struct unix_sock *u = unix_sk(s);
237
238 if (u->addr->len == len &&
239 !memcmp(u->addr->name, sunname, len))
240 goto found;
241 }
242 s = NULL;
243 found:
244 return s;
245 }
246
247 static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname,
248 int len, int type,
249 unsigned hash)
250 {
251 struct sock *s;
252
253 spin_lock(&unix_table_lock);
254 s = __unix_find_socket_byname(sunname, len, type, hash);
255 if (s)
256 sock_hold(s);
257 spin_unlock(&unix_table_lock);
258 return s;
259 }
260
261 static struct sock *unix_find_socket_byinode(struct inode *i)
262 {
263 struct sock *s;
264 struct hlist_node *node;
265
266 spin_lock(&unix_table_lock);
267 sk_for_each(s, node,
268 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
269 struct dentry *dentry = unix_sk(s)->dentry;
270
271 if(dentry && dentry->d_inode == i)
272 {
273 sock_hold(s);
274 goto found;
275 }
276 }
277 s = NULL;
278 found:
279 spin_unlock(&unix_table_lock);
280 return s;
281 }
282
283 static inline int unix_writable(struct sock *sk)
284 {
285 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
286 }
287
288 static void unix_write_space(struct sock *sk)
289 {
290 read_lock(&sk->sk_callback_lock);
291 if (unix_writable(sk)) {
292 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
293 wake_up_interruptible(sk->sk_sleep);
294 sk_wake_async(sk, 2, POLL_OUT);
295 }
296 read_unlock(&sk->sk_callback_lock);
297 }
298
299 /* When dgram socket disconnects (or changes its peer), we clear its receive
300 * queue of packets arrived from previous peer. First, it allows to do
301 * flow control based only on wmem_alloc; second, sk connected to peer
302 * may receive messages only from that peer. */
303 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
304 {
305 if (!skb_queue_empty(&sk->sk_receive_queue)) {
306 skb_queue_purge(&sk->sk_receive_queue);
307 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
308
309 /* If one link of bidirectional dgram pipe is disconnected,
310 * we signal error. Messages are lost. Do not make this,
311 * when peer was not connected to us.
312 */
313 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
314 other->sk_err = ECONNRESET;
315 other->sk_error_report(other);
316 }
317 }
318 }
319
320 static void unix_sock_destructor(struct sock *sk)
321 {
322 struct unix_sock *u = unix_sk(sk);
323
324 skb_queue_purge(&sk->sk_receive_queue);
325
326 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
327 BUG_TRAP(sk_unhashed(sk));
328 BUG_TRAP(!sk->sk_socket);
329 if (!sock_flag(sk, SOCK_DEAD)) {
330 printk("Attempt to release alive unix socket: %p\n", sk);
331 return;
332 }
333
334 if (u->addr)
335 unix_release_addr(u->addr);
336
337 atomic_dec(&unix_nr_socks);
338 #ifdef UNIX_REFCNT_DEBUG
339 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
340 #endif
341 }
342
343 static int unix_release_sock (struct sock *sk, int embrion)
344 {
345 struct unix_sock *u = unix_sk(sk);
346 struct dentry *dentry;
347 struct vfsmount *mnt;
348 struct sock *skpair;
349 struct sk_buff *skb;
350 int state;
351
352 unix_remove_socket(sk);
353
354 /* Clear state */
355 unix_state_wlock(sk);
356 sock_orphan(sk);
357 sk->sk_shutdown = SHUTDOWN_MASK;
358 dentry = u->dentry;
359 u->dentry = NULL;
360 mnt = u->mnt;
361 u->mnt = NULL;
362 state = sk->sk_state;
363 sk->sk_state = TCP_CLOSE;
364 unix_state_wunlock(sk);
365
366 wake_up_interruptible_all(&u->peer_wait);
367
368 skpair=unix_peer(sk);
369
370 if (skpair!=NULL) {
371 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
372 unix_state_wlock(skpair);
373 /* No more writes */
374 skpair->sk_shutdown = SHUTDOWN_MASK;
375 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
376 skpair->sk_err = ECONNRESET;
377 unix_state_wunlock(skpair);
378 skpair->sk_state_change(skpair);
379 read_lock(&skpair->sk_callback_lock);
380 sk_wake_async(skpair,1,POLL_HUP);
381 read_unlock(&skpair->sk_callback_lock);
382 }
383 sock_put(skpair); /* It may now die */
384 unix_peer(sk) = NULL;
385 }
386
387 /* Try to flush out this socket. Throw out buffers at least */
388
389 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
390 if (state==TCP_LISTEN)
391 unix_release_sock(skb->sk, 1);
392 /* passed fds are erased in the kfree_skb hook */
393 kfree_skb(skb);
394 }
395
396 if (dentry) {
397 dput(dentry);
398 mntput(mnt);
399 }
400
401 sock_put(sk);
402
403 /* ---- Socket is dead now and most probably destroyed ---- */
404
405 /*
406 * Fixme: BSD difference: In BSD all sockets connected to use get
407 * ECONNRESET and we die on the spot. In Linux we behave
408 * like files and pipes do and wait for the last
409 * dereference.
410 *
411 * Can't we simply set sock->err?
412 *
413 * What the above comment does talk about? --ANK(980817)
414 */
415
416 if (atomic_read(&unix_tot_inflight))
417 unix_gc(); /* Garbage collect fds */
418
419 return 0;
420 }
421
422 static int unix_listen(struct socket *sock, int backlog)
423 {
424 int err;
425 struct sock *sk = sock->sk;
426 struct unix_sock *u = unix_sk(sk);
427
428 err = -EOPNOTSUPP;
429 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
430 goto out; /* Only stream/seqpacket sockets accept */
431 err = -EINVAL;
432 if (!u->addr)
433 goto out; /* No listens on an unbound socket */
434 unix_state_wlock(sk);
435 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
436 goto out_unlock;
437 if (backlog > sk->sk_max_ack_backlog)
438 wake_up_interruptible_all(&u->peer_wait);
439 sk->sk_max_ack_backlog = backlog;
440 sk->sk_state = TCP_LISTEN;
441 /* set credentials so connect can copy them */
442 sk->sk_peercred.pid = current->tgid;
443 sk->sk_peercred.uid = current->euid;
444 sk->sk_peercred.gid = current->egid;
445 err = 0;
446
447 out_unlock:
448 unix_state_wunlock(sk);
449 out:
450 return err;
451 }
452
453 static int unix_release(struct socket *);
454 static int unix_bind(struct socket *, struct sockaddr *, int);
455 static int unix_stream_connect(struct socket *, struct sockaddr *,
456 int addr_len, int flags);
457 static int unix_socketpair(struct socket *, struct socket *);
458 static int unix_accept(struct socket *, struct socket *, int);
459 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
460 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
461 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
462 static int unix_shutdown(struct socket *, int);
463 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
464 struct msghdr *, size_t);
465 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
466 struct msghdr *, size_t, int);
467 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
468 struct msghdr *, size_t);
469 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
470 struct msghdr *, size_t, int);
471 static int unix_dgram_connect(struct socket *, struct sockaddr *,
472 int, int);
473 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
474 struct msghdr *, size_t);
475
476 static const struct proto_ops unix_stream_ops = {
477 .family = PF_UNIX,
478 .owner = THIS_MODULE,
479 .release = unix_release,
480 .bind = unix_bind,
481 .connect = unix_stream_connect,
482 .socketpair = unix_socketpair,
483 .accept = unix_accept,
484 .getname = unix_getname,
485 .poll = unix_poll,
486 .ioctl = unix_ioctl,
487 .listen = unix_listen,
488 .shutdown = unix_shutdown,
489 .setsockopt = sock_no_setsockopt,
490 .getsockopt = sock_no_getsockopt,
491 .sendmsg = unix_stream_sendmsg,
492 .recvmsg = unix_stream_recvmsg,
493 .mmap = sock_no_mmap,
494 .sendpage = sock_no_sendpage,
495 };
496
497 static const struct proto_ops unix_dgram_ops = {
498 .family = PF_UNIX,
499 .owner = THIS_MODULE,
500 .release = unix_release,
501 .bind = unix_bind,
502 .connect = unix_dgram_connect,
503 .socketpair = unix_socketpair,
504 .accept = sock_no_accept,
505 .getname = unix_getname,
506 .poll = datagram_poll,
507 .ioctl = unix_ioctl,
508 .listen = sock_no_listen,
509 .shutdown = unix_shutdown,
510 .setsockopt = sock_no_setsockopt,
511 .getsockopt = sock_no_getsockopt,
512 .sendmsg = unix_dgram_sendmsg,
513 .recvmsg = unix_dgram_recvmsg,
514 .mmap = sock_no_mmap,
515 .sendpage = sock_no_sendpage,
516 };
517
518 static const struct proto_ops unix_seqpacket_ops = {
519 .family = PF_UNIX,
520 .owner = THIS_MODULE,
521 .release = unix_release,
522 .bind = unix_bind,
523 .connect = unix_stream_connect,
524 .socketpair = unix_socketpair,
525 .accept = unix_accept,
526 .getname = unix_getname,
527 .poll = datagram_poll,
528 .ioctl = unix_ioctl,
529 .listen = unix_listen,
530 .shutdown = unix_shutdown,
531 .setsockopt = sock_no_setsockopt,
532 .getsockopt = sock_no_getsockopt,
533 .sendmsg = unix_seqpacket_sendmsg,
534 .recvmsg = unix_dgram_recvmsg,
535 .mmap = sock_no_mmap,
536 .sendpage = sock_no_sendpage,
537 };
538
539 static struct proto unix_proto = {
540 .name = "UNIX",
541 .owner = THIS_MODULE,
542 .obj_size = sizeof(struct unix_sock),
543 };
544
545 static struct sock * unix_create1(struct socket *sock)
546 {
547 struct sock *sk = NULL;
548 struct unix_sock *u;
549
550 if (atomic_read(&unix_nr_socks) >= 2*get_max_files())
551 goto out;
552
553 sk = sk_alloc(PF_UNIX, GFP_KERNEL, &unix_proto, 1);
554 if (!sk)
555 goto out;
556
557 atomic_inc(&unix_nr_socks);
558
559 sock_init_data(sock,sk);
560
561 sk->sk_write_space = unix_write_space;
562 sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen;
563 sk->sk_destruct = unix_sock_destructor;
564 u = unix_sk(sk);
565 u->dentry = NULL;
566 u->mnt = NULL;
567 spin_lock_init(&u->lock);
568 atomic_set(&u->inflight, sock ? 0 : -1);
569 mutex_init(&u->readlock); /* single task reading lock */
570 init_waitqueue_head(&u->peer_wait);
571 unix_insert_socket(unix_sockets_unbound, sk);
572 out:
573 return sk;
574 }
575
576 static int unix_create(struct socket *sock, int protocol)
577 {
578 if (protocol && protocol != PF_UNIX)
579 return -EPROTONOSUPPORT;
580
581 sock->state = SS_UNCONNECTED;
582
583 switch (sock->type) {
584 case SOCK_STREAM:
585 sock->ops = &unix_stream_ops;
586 break;
587 /*
588 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
589 * nothing uses it.
590 */
591 case SOCK_RAW:
592 sock->type=SOCK_DGRAM;
593 case SOCK_DGRAM:
594 sock->ops = &unix_dgram_ops;
595 break;
596 case SOCK_SEQPACKET:
597 sock->ops = &unix_seqpacket_ops;
598 break;
599 default:
600 return -ESOCKTNOSUPPORT;
601 }
602
603 return unix_create1(sock) ? 0 : -ENOMEM;
604 }
605
606 static int unix_release(struct socket *sock)
607 {
608 struct sock *sk = sock->sk;
609
610 if (!sk)
611 return 0;
612
613 sock->sk = NULL;
614
615 return unix_release_sock (sk, 0);
616 }
617
618 static int unix_autobind(struct socket *sock)
619 {
620 struct sock *sk = sock->sk;
621 struct unix_sock *u = unix_sk(sk);
622 static u32 ordernum = 1;
623 struct unix_address * addr;
624 int err;
625
626 mutex_lock(&u->readlock);
627
628 err = 0;
629 if (u->addr)
630 goto out;
631
632 err = -ENOMEM;
633 addr = kmalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
634 if (!addr)
635 goto out;
636
637 memset(addr, 0, sizeof(*addr) + sizeof(short) + 16);
638 addr->name->sun_family = AF_UNIX;
639 atomic_set(&addr->refcnt, 1);
640
641 retry:
642 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
643 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
644
645 spin_lock(&unix_table_lock);
646 ordernum = (ordernum+1)&0xFFFFF;
647
648 if (__unix_find_socket_byname(addr->name, addr->len, sock->type,
649 addr->hash)) {
650 spin_unlock(&unix_table_lock);
651 /* Sanity yield. It is unusual case, but yet... */
652 if (!(ordernum&0xFF))
653 yield();
654 goto retry;
655 }
656 addr->hash ^= sk->sk_type;
657
658 __unix_remove_socket(sk);
659 u->addr = addr;
660 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
661 spin_unlock(&unix_table_lock);
662 err = 0;
663
664 out: mutex_unlock(&u->readlock);
665 return err;
666 }
667
668 static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
669 int type, unsigned hash, int *error)
670 {
671 struct sock *u;
672 struct nameidata nd;
673 int err = 0;
674
675 if (sunname->sun_path[0]) {
676 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
677 if (err)
678 goto fail;
679 err = vfs_permission(&nd, MAY_WRITE);
680 if (err)
681 goto put_fail;
682
683 err = -ECONNREFUSED;
684 if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
685 goto put_fail;
686 u=unix_find_socket_byinode(nd.dentry->d_inode);
687 if (!u)
688 goto put_fail;
689
690 if (u->sk_type == type)
691 touch_atime(nd.mnt, nd.dentry);
692
693 path_release(&nd);
694
695 err=-EPROTOTYPE;
696 if (u->sk_type != type) {
697 sock_put(u);
698 goto fail;
699 }
700 } else {
701 err = -ECONNREFUSED;
702 u=unix_find_socket_byname(sunname, len, type, hash);
703 if (u) {
704 struct dentry *dentry;
705 dentry = unix_sk(u)->dentry;
706 if (dentry)
707 touch_atime(unix_sk(u)->mnt, dentry);
708 } else
709 goto fail;
710 }
711 return u;
712
713 put_fail:
714 path_release(&nd);
715 fail:
716 *error=err;
717 return NULL;
718 }
719
720
721 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
722 {
723 struct sock *sk = sock->sk;
724 struct unix_sock *u = unix_sk(sk);
725 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
726 struct dentry * dentry = NULL;
727 struct nameidata nd;
728 int err;
729 unsigned hash;
730 struct unix_address *addr;
731 struct hlist_head *list;
732
733 err = -EINVAL;
734 if (sunaddr->sun_family != AF_UNIX)
735 goto out;
736
737 if (addr_len==sizeof(short)) {
738 err = unix_autobind(sock);
739 goto out;
740 }
741
742 err = unix_mkname(sunaddr, addr_len, &hash);
743 if (err < 0)
744 goto out;
745 addr_len = err;
746
747 mutex_lock(&u->readlock);
748
749 err = -EINVAL;
750 if (u->addr)
751 goto out_up;
752
753 err = -ENOMEM;
754 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
755 if (!addr)
756 goto out_up;
757
758 memcpy(addr->name, sunaddr, addr_len);
759 addr->len = addr_len;
760 addr->hash = hash ^ sk->sk_type;
761 atomic_set(&addr->refcnt, 1);
762
763 if (sunaddr->sun_path[0]) {
764 unsigned int mode;
765 err = 0;
766 /*
767 * Get the parent directory, calculate the hash for last
768 * component.
769 */
770 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
771 if (err)
772 goto out_mknod_parent;
773
774 dentry = lookup_create(&nd, 0);
775 err = PTR_ERR(dentry);
776 if (IS_ERR(dentry))
777 goto out_mknod_unlock;
778
779 /*
780 * All right, let's create it.
781 */
782 mode = S_IFSOCK |
783 (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
784 err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
785 if (err)
786 goto out_mknod_dput;
787 mutex_unlock(&nd.dentry->d_inode->i_mutex);
788 dput(nd.dentry);
789 nd.dentry = dentry;
790
791 addr->hash = UNIX_HASH_SIZE;
792 }
793
794 spin_lock(&unix_table_lock);
795
796 if (!sunaddr->sun_path[0]) {
797 err = -EADDRINUSE;
798 if (__unix_find_socket_byname(sunaddr, addr_len,
799 sk->sk_type, hash)) {
800 unix_release_addr(addr);
801 goto out_unlock;
802 }
803
804 list = &unix_socket_table[addr->hash];
805 } else {
806 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
807 u->dentry = nd.dentry;
808 u->mnt = nd.mnt;
809 }
810
811 err = 0;
812 __unix_remove_socket(sk);
813 u->addr = addr;
814 __unix_insert_socket(list, sk);
815
816 out_unlock:
817 spin_unlock(&unix_table_lock);
818 out_up:
819 mutex_unlock(&u->readlock);
820 out:
821 return err;
822
823 out_mknod_dput:
824 dput(dentry);
825 out_mknod_unlock:
826 mutex_unlock(&nd.dentry->d_inode->i_mutex);
827 path_release(&nd);
828 out_mknod_parent:
829 if (err==-EEXIST)
830 err=-EADDRINUSE;
831 unix_release_addr(addr);
832 goto out_up;
833 }
834
835 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
836 int alen, int flags)
837 {
838 struct sock *sk = sock->sk;
839 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
840 struct sock *other;
841 unsigned hash;
842 int err;
843
844 if (addr->sa_family != AF_UNSPEC) {
845 err = unix_mkname(sunaddr, alen, &hash);
846 if (err < 0)
847 goto out;
848 alen = err;
849
850 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
851 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
852 goto out;
853
854 other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
855 if (!other)
856 goto out;
857
858 unix_state_wlock(sk);
859
860 err = -EPERM;
861 if (!unix_may_send(sk, other))
862 goto out_unlock;
863
864 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
865 if (err)
866 goto out_unlock;
867
868 } else {
869 /*
870 * 1003.1g breaking connected state with AF_UNSPEC
871 */
872 other = NULL;
873 unix_state_wlock(sk);
874 }
875
876 /*
877 * If it was connected, reconnect.
878 */
879 if (unix_peer(sk)) {
880 struct sock *old_peer = unix_peer(sk);
881 unix_peer(sk)=other;
882 unix_state_wunlock(sk);
883
884 if (other != old_peer)
885 unix_dgram_disconnected(sk, old_peer);
886 sock_put(old_peer);
887 } else {
888 unix_peer(sk)=other;
889 unix_state_wunlock(sk);
890 }
891 return 0;
892
893 out_unlock:
894 unix_state_wunlock(sk);
895 sock_put(other);
896 out:
897 return err;
898 }
899
900 static long unix_wait_for_peer(struct sock *other, long timeo)
901 {
902 struct unix_sock *u = unix_sk(other);
903 int sched;
904 DEFINE_WAIT(wait);
905
906 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
907
908 sched = !sock_flag(other, SOCK_DEAD) &&
909 !(other->sk_shutdown & RCV_SHUTDOWN) &&
910 (skb_queue_len(&other->sk_receive_queue) >
911 other->sk_max_ack_backlog);
912
913 unix_state_runlock(other);
914
915 if (sched)
916 timeo = schedule_timeout(timeo);
917
918 finish_wait(&u->peer_wait, &wait);
919 return timeo;
920 }
921
922 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
923 int addr_len, int flags)
924 {
925 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
926 struct sock *sk = sock->sk;
927 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
928 struct sock *newsk = NULL;
929 struct sock *other = NULL;
930 struct sk_buff *skb = NULL;
931 unsigned hash;
932 int st;
933 int err;
934 long timeo;
935
936 err = unix_mkname(sunaddr, addr_len, &hash);
937 if (err < 0)
938 goto out;
939 addr_len = err;
940
941 if (test_bit(SOCK_PASSCRED, &sock->flags)
942 && !u->addr && (err = unix_autobind(sock)) != 0)
943 goto out;
944
945 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
946
947 /* First of all allocate resources.
948 If we will make it after state is locked,
949 we will have to recheck all again in any case.
950 */
951
952 err = -ENOMEM;
953
954 /* create new sock for complete connection */
955 newsk = unix_create1(NULL);
956 if (newsk == NULL)
957 goto out;
958
959 /* Allocate skb for sending to listening sock */
960 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
961 if (skb == NULL)
962 goto out;
963
964 restart:
965 /* Find listening sock. */
966 other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err);
967 if (!other)
968 goto out;
969
970 /* Latch state of peer */
971 unix_state_rlock(other);
972
973 /* Apparently VFS overslept socket death. Retry. */
974 if (sock_flag(other, SOCK_DEAD)) {
975 unix_state_runlock(other);
976 sock_put(other);
977 goto restart;
978 }
979
980 err = -ECONNREFUSED;
981 if (other->sk_state != TCP_LISTEN)
982 goto out_unlock;
983
984 if (skb_queue_len(&other->sk_receive_queue) >
985 other->sk_max_ack_backlog) {
986 err = -EAGAIN;
987 if (!timeo)
988 goto out_unlock;
989
990 timeo = unix_wait_for_peer(other, timeo);
991
992 err = sock_intr_errno(timeo);
993 if (signal_pending(current))
994 goto out;
995 sock_put(other);
996 goto restart;
997 }
998
999 /* Latch our state.
1000
1001 It is tricky place. We need to grab write lock and cannot
1002 drop lock on peer. It is dangerous because deadlock is
1003 possible. Connect to self case and simultaneous
1004 attempt to connect are eliminated by checking socket
1005 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1006 check this before attempt to grab lock.
1007
1008 Well, and we have to recheck the state after socket locked.
1009 */
1010 st = sk->sk_state;
1011
1012 switch (st) {
1013 case TCP_CLOSE:
1014 /* This is ok... continue with connect */
1015 break;
1016 case TCP_ESTABLISHED:
1017 /* Socket is already connected */
1018 err = -EISCONN;
1019 goto out_unlock;
1020 default:
1021 err = -EINVAL;
1022 goto out_unlock;
1023 }
1024
1025 unix_state_wlock(sk);
1026
1027 if (sk->sk_state != st) {
1028 unix_state_wunlock(sk);
1029 unix_state_runlock(other);
1030 sock_put(other);
1031 goto restart;
1032 }
1033
1034 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1035 if (err) {
1036 unix_state_wunlock(sk);
1037 goto out_unlock;
1038 }
1039
1040 /* The way is open! Fastly set all the necessary fields... */
1041
1042 sock_hold(sk);
1043 unix_peer(newsk) = sk;
1044 newsk->sk_state = TCP_ESTABLISHED;
1045 newsk->sk_type = sk->sk_type;
1046 newsk->sk_peercred.pid = current->tgid;
1047 newsk->sk_peercred.uid = current->euid;
1048 newsk->sk_peercred.gid = current->egid;
1049 newu = unix_sk(newsk);
1050 newsk->sk_sleep = &newu->peer_wait;
1051 otheru = unix_sk(other);
1052
1053 /* copy address information from listening to new sock*/
1054 if (otheru->addr) {
1055 atomic_inc(&otheru->addr->refcnt);
1056 newu->addr = otheru->addr;
1057 }
1058 if (otheru->dentry) {
1059 newu->dentry = dget(otheru->dentry);
1060 newu->mnt = mntget(otheru->mnt);
1061 }
1062
1063 /* Set credentials */
1064 sk->sk_peercred = other->sk_peercred;
1065
1066 sock->state = SS_CONNECTED;
1067 sk->sk_state = TCP_ESTABLISHED;
1068 sock_hold(newsk);
1069
1070 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1071 unix_peer(sk) = newsk;
1072
1073 unix_state_wunlock(sk);
1074
1075 /* take ten and and send info to listening sock */
1076 spin_lock(&other->sk_receive_queue.lock);
1077 __skb_queue_tail(&other->sk_receive_queue, skb);
1078 /* Undo artificially decreased inflight after embrion
1079 * is installed to listening socket. */
1080 atomic_inc(&newu->inflight);
1081 spin_unlock(&other->sk_receive_queue.lock);
1082 unix_state_runlock(other);
1083 other->sk_data_ready(other, 0);
1084 sock_put(other);
1085 return 0;
1086
1087 out_unlock:
1088 if (other)
1089 unix_state_runlock(other);
1090
1091 out:
1092 if (skb)
1093 kfree_skb(skb);
1094 if (newsk)
1095 unix_release_sock(newsk, 0);
1096 if (other)
1097 sock_put(other);
1098 return err;
1099 }
1100
1101 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1102 {
1103 struct sock *ska=socka->sk, *skb = sockb->sk;
1104
1105 /* Join our sockets back to back */
1106 sock_hold(ska);
1107 sock_hold(skb);
1108 unix_peer(ska)=skb;
1109 unix_peer(skb)=ska;
1110 ska->sk_peercred.pid = skb->sk_peercred.pid = current->tgid;
1111 ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid;
1112 ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid;
1113
1114 if (ska->sk_type != SOCK_DGRAM) {
1115 ska->sk_state = TCP_ESTABLISHED;
1116 skb->sk_state = TCP_ESTABLISHED;
1117 socka->state = SS_CONNECTED;
1118 sockb->state = SS_CONNECTED;
1119 }
1120 return 0;
1121 }
1122
1123 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1124 {
1125 struct sock *sk = sock->sk;
1126 struct sock *tsk;
1127 struct sk_buff *skb;
1128 int err;
1129
1130 err = -EOPNOTSUPP;
1131 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1132 goto out;
1133
1134 err = -EINVAL;
1135 if (sk->sk_state != TCP_LISTEN)
1136 goto out;
1137
1138 /* If socket state is TCP_LISTEN it cannot change (for now...),
1139 * so that no locks are necessary.
1140 */
1141
1142 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1143 if (!skb) {
1144 /* This means receive shutdown. */
1145 if (err == 0)
1146 err = -EINVAL;
1147 goto out;
1148 }
1149
1150 tsk = skb->sk;
1151 skb_free_datagram(sk, skb);
1152 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1153
1154 /* attach accepted sock to socket */
1155 unix_state_wlock(tsk);
1156 newsock->state = SS_CONNECTED;
1157 sock_graft(tsk, newsock);
1158 unix_state_wunlock(tsk);
1159 return 0;
1160
1161 out:
1162 return err;
1163 }
1164
1165
1166 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1167 {
1168 struct sock *sk = sock->sk;
1169 struct unix_sock *u;
1170 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1171 int err = 0;
1172
1173 if (peer) {
1174 sk = unix_peer_get(sk);
1175
1176 err = -ENOTCONN;
1177 if (!sk)
1178 goto out;
1179 err = 0;
1180 } else {
1181 sock_hold(sk);
1182 }
1183
1184 u = unix_sk(sk);
1185 unix_state_rlock(sk);
1186 if (!u->addr) {
1187 sunaddr->sun_family = AF_UNIX;
1188 sunaddr->sun_path[0] = 0;
1189 *uaddr_len = sizeof(short);
1190 } else {
1191 struct unix_address *addr = u->addr;
1192
1193 *uaddr_len = addr->len;
1194 memcpy(sunaddr, addr->name, *uaddr_len);
1195 }
1196 unix_state_runlock(sk);
1197 sock_put(sk);
1198 out:
1199 return err;
1200 }
1201
1202 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1203 {
1204 int i;
1205
1206 scm->fp = UNIXCB(skb).fp;
1207 skb->destructor = sock_wfree;
1208 UNIXCB(skb).fp = NULL;
1209
1210 for (i=scm->fp->count-1; i>=0; i--)
1211 unix_notinflight(scm->fp->fp[i]);
1212 }
1213
1214 static void unix_destruct_fds(struct sk_buff *skb)
1215 {
1216 struct scm_cookie scm;
1217 memset(&scm, 0, sizeof(scm));
1218 unix_detach_fds(&scm, skb);
1219
1220 /* Alas, it calls VFS */
1221 /* So fscking what? fput() had been SMP-safe since the last Summer */
1222 scm_destroy(&scm);
1223 sock_wfree(skb);
1224 }
1225
1226 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1227 {
1228 int i;
1229 for (i=scm->fp->count-1; i>=0; i--)
1230 unix_inflight(scm->fp->fp[i]);
1231 UNIXCB(skb).fp = scm->fp;
1232 skb->destructor = unix_destruct_fds;
1233 scm->fp = NULL;
1234 }
1235
1236 /*
1237 * Send AF_UNIX data.
1238 */
1239
1240 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1241 struct msghdr *msg, size_t len)
1242 {
1243 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1244 struct sock *sk = sock->sk;
1245 struct unix_sock *u = unix_sk(sk);
1246 struct sockaddr_un *sunaddr=msg->msg_name;
1247 struct sock *other = NULL;
1248 int namelen = 0; /* fake GCC */
1249 int err;
1250 unsigned hash;
1251 struct sk_buff *skb;
1252 long timeo;
1253 struct scm_cookie tmp_scm;
1254
1255 if (NULL == siocb->scm)
1256 siocb->scm = &tmp_scm;
1257 err = scm_send(sock, msg, siocb->scm);
1258 if (err < 0)
1259 return err;
1260
1261 err = -EOPNOTSUPP;
1262 if (msg->msg_flags&MSG_OOB)
1263 goto out;
1264
1265 if (msg->msg_namelen) {
1266 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1267 if (err < 0)
1268 goto out;
1269 namelen = err;
1270 } else {
1271 sunaddr = NULL;
1272 err = -ENOTCONN;
1273 other = unix_peer_get(sk);
1274 if (!other)
1275 goto out;
1276 }
1277
1278 if (test_bit(SOCK_PASSCRED, &sock->flags)
1279 && !u->addr && (err = unix_autobind(sock)) != 0)
1280 goto out;
1281
1282 err = -EMSGSIZE;
1283 if (len > sk->sk_sndbuf - 32)
1284 goto out;
1285
1286 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1287 if (skb==NULL)
1288 goto out;
1289
1290 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1291 if (siocb->scm->fp)
1292 unix_attach_fds(siocb->scm, skb);
1293
1294 skb->h.raw = skb->data;
1295 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1296 if (err)
1297 goto out_free;
1298
1299 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1300
1301 restart:
1302 if (!other) {
1303 err = -ECONNRESET;
1304 if (sunaddr == NULL)
1305 goto out_free;
1306
1307 other = unix_find_other(sunaddr, namelen, sk->sk_type,
1308 hash, &err);
1309 if (other==NULL)
1310 goto out_free;
1311 }
1312
1313 unix_state_rlock(other);
1314 err = -EPERM;
1315 if (!unix_may_send(sk, other))
1316 goto out_unlock;
1317
1318 if (sock_flag(other, SOCK_DEAD)) {
1319 /*
1320 * Check with 1003.1g - what should
1321 * datagram error
1322 */
1323 unix_state_runlock(other);
1324 sock_put(other);
1325
1326 err = 0;
1327 unix_state_wlock(sk);
1328 if (unix_peer(sk) == other) {
1329 unix_peer(sk)=NULL;
1330 unix_state_wunlock(sk);
1331
1332 unix_dgram_disconnected(sk, other);
1333 sock_put(other);
1334 err = -ECONNREFUSED;
1335 } else {
1336 unix_state_wunlock(sk);
1337 }
1338
1339 other = NULL;
1340 if (err)
1341 goto out_free;
1342 goto restart;
1343 }
1344
1345 err = -EPIPE;
1346 if (other->sk_shutdown & RCV_SHUTDOWN)
1347 goto out_unlock;
1348
1349 if (sk->sk_type != SOCK_SEQPACKET) {
1350 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1351 if (err)
1352 goto out_unlock;
1353 }
1354
1355 if (unix_peer(other) != sk &&
1356 (skb_queue_len(&other->sk_receive_queue) >
1357 other->sk_max_ack_backlog)) {
1358 if (!timeo) {
1359 err = -EAGAIN;
1360 goto out_unlock;
1361 }
1362
1363 timeo = unix_wait_for_peer(other, timeo);
1364
1365 err = sock_intr_errno(timeo);
1366 if (signal_pending(current))
1367 goto out_free;
1368
1369 goto restart;
1370 }
1371
1372 skb_queue_tail(&other->sk_receive_queue, skb);
1373 unix_state_runlock(other);
1374 other->sk_data_ready(other, len);
1375 sock_put(other);
1376 scm_destroy(siocb->scm);
1377 return len;
1378
1379 out_unlock:
1380 unix_state_runlock(other);
1381 out_free:
1382 kfree_skb(skb);
1383 out:
1384 if (other)
1385 sock_put(other);
1386 scm_destroy(siocb->scm);
1387 return err;
1388 }
1389
1390
1391 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1392 struct msghdr *msg, size_t len)
1393 {
1394 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1395 struct sock *sk = sock->sk;
1396 struct sock *other = NULL;
1397 struct sockaddr_un *sunaddr=msg->msg_name;
1398 int err,size;
1399 struct sk_buff *skb;
1400 int sent=0;
1401 struct scm_cookie tmp_scm;
1402
1403 if (NULL == siocb->scm)
1404 siocb->scm = &tmp_scm;
1405 err = scm_send(sock, msg, siocb->scm);
1406 if (err < 0)
1407 return err;
1408
1409 err = -EOPNOTSUPP;
1410 if (msg->msg_flags&MSG_OOB)
1411 goto out_err;
1412
1413 if (msg->msg_namelen) {
1414 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1415 goto out_err;
1416 } else {
1417 sunaddr = NULL;
1418 err = -ENOTCONN;
1419 other = unix_peer(sk);
1420 if (!other)
1421 goto out_err;
1422 }
1423
1424 if (sk->sk_shutdown & SEND_SHUTDOWN)
1425 goto pipe_err;
1426
1427 while(sent < len)
1428 {
1429 /*
1430 * Optimisation for the fact that under 0.01% of X
1431 * messages typically need breaking up.
1432 */
1433
1434 size = len-sent;
1435
1436 /* Keep two messages in the pipe so it schedules better */
1437 if (size > ((sk->sk_sndbuf >> 1) - 64))
1438 size = (sk->sk_sndbuf >> 1) - 64;
1439
1440 if (size > SKB_MAX_ALLOC)
1441 size = SKB_MAX_ALLOC;
1442
1443 /*
1444 * Grab a buffer
1445 */
1446
1447 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1448
1449 if (skb==NULL)
1450 goto out_err;
1451
1452 /*
1453 * If you pass two values to the sock_alloc_send_skb
1454 * it tries to grab the large buffer with GFP_NOFS
1455 * (which can fail easily), and if it fails grab the
1456 * fallback size buffer which is under a page and will
1457 * succeed. [Alan]
1458 */
1459 size = min_t(int, size, skb_tailroom(skb));
1460
1461 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1462 if (siocb->scm->fp)
1463 unix_attach_fds(siocb->scm, skb);
1464
1465 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1466 kfree_skb(skb);
1467 goto out_err;
1468 }
1469
1470 unix_state_rlock(other);
1471
1472 if (sock_flag(other, SOCK_DEAD) ||
1473 (other->sk_shutdown & RCV_SHUTDOWN))
1474 goto pipe_err_free;
1475
1476 skb_queue_tail(&other->sk_receive_queue, skb);
1477 unix_state_runlock(other);
1478 other->sk_data_ready(other, size);
1479 sent+=size;
1480 }
1481
1482 scm_destroy(siocb->scm);
1483 siocb->scm = NULL;
1484
1485 return sent;
1486
1487 pipe_err_free:
1488 unix_state_runlock(other);
1489 kfree_skb(skb);
1490 pipe_err:
1491 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1492 send_sig(SIGPIPE,current,0);
1493 err = -EPIPE;
1494 out_err:
1495 scm_destroy(siocb->scm);
1496 siocb->scm = NULL;
1497 return sent ? : err;
1498 }
1499
1500 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1501 struct msghdr *msg, size_t len)
1502 {
1503 int err;
1504 struct sock *sk = sock->sk;
1505
1506 err = sock_error(sk);
1507 if (err)
1508 return err;
1509
1510 if (sk->sk_state != TCP_ESTABLISHED)
1511 return -ENOTCONN;
1512
1513 if (msg->msg_namelen)
1514 msg->msg_namelen = 0;
1515
1516 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1517 }
1518
1519 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1520 {
1521 struct unix_sock *u = unix_sk(sk);
1522
1523 msg->msg_namelen = 0;
1524 if (u->addr) {
1525 msg->msg_namelen = u->addr->len;
1526 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1527 }
1528 }
1529
1530 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1531 struct msghdr *msg, size_t size,
1532 int flags)
1533 {
1534 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1535 struct scm_cookie tmp_scm;
1536 struct sock *sk = sock->sk;
1537 struct unix_sock *u = unix_sk(sk);
1538 int noblock = flags & MSG_DONTWAIT;
1539 struct sk_buff *skb;
1540 int err;
1541
1542 err = -EOPNOTSUPP;
1543 if (flags&MSG_OOB)
1544 goto out;
1545
1546 msg->msg_namelen = 0;
1547
1548 mutex_lock(&u->readlock);
1549
1550 skb = skb_recv_datagram(sk, flags, noblock, &err);
1551 if (!skb)
1552 goto out_unlock;
1553
1554 wake_up_interruptible(&u->peer_wait);
1555
1556 if (msg->msg_name)
1557 unix_copy_addr(msg, skb->sk);
1558
1559 if (size > skb->len)
1560 size = skb->len;
1561 else if (size < skb->len)
1562 msg->msg_flags |= MSG_TRUNC;
1563
1564 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1565 if (err)
1566 goto out_free;
1567
1568 if (!siocb->scm) {
1569 siocb->scm = &tmp_scm;
1570 memset(&tmp_scm, 0, sizeof(tmp_scm));
1571 }
1572 siocb->scm->creds = *UNIXCREDS(skb);
1573
1574 if (!(flags & MSG_PEEK))
1575 {
1576 if (UNIXCB(skb).fp)
1577 unix_detach_fds(siocb->scm, skb);
1578 }
1579 else
1580 {
1581 /* It is questionable: on PEEK we could:
1582 - do not return fds - good, but too simple 8)
1583 - return fds, and do not return them on read (old strategy,
1584 apparently wrong)
1585 - clone fds (I chose it for now, it is the most universal
1586 solution)
1587
1588 POSIX 1003.1g does not actually define this clearly
1589 at all. POSIX 1003.1g doesn't define a lot of things
1590 clearly however!
1591
1592 */
1593 if (UNIXCB(skb).fp)
1594 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1595 }
1596 err = size;
1597
1598 scm_recv(sock, msg, siocb->scm, flags);
1599
1600 out_free:
1601 skb_free_datagram(sk,skb);
1602 out_unlock:
1603 mutex_unlock(&u->readlock);
1604 out:
1605 return err;
1606 }
1607
1608 /*
1609 * Sleep until data has arrive. But check for races..
1610 */
1611
1612 static long unix_stream_data_wait(struct sock * sk, long timeo)
1613 {
1614 DEFINE_WAIT(wait);
1615
1616 unix_state_rlock(sk);
1617
1618 for (;;) {
1619 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1620
1621 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1622 sk->sk_err ||
1623 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1624 signal_pending(current) ||
1625 !timeo)
1626 break;
1627
1628 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1629 unix_state_runlock(sk);
1630 timeo = schedule_timeout(timeo);
1631 unix_state_rlock(sk);
1632 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1633 }
1634
1635 finish_wait(sk->sk_sleep, &wait);
1636 unix_state_runlock(sk);
1637 return timeo;
1638 }
1639
1640
1641
1642 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1643 struct msghdr *msg, size_t size,
1644 int flags)
1645 {
1646 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1647 struct scm_cookie tmp_scm;
1648 struct sock *sk = sock->sk;
1649 struct unix_sock *u = unix_sk(sk);
1650 struct sockaddr_un *sunaddr=msg->msg_name;
1651 int copied = 0;
1652 int check_creds = 0;
1653 int target;
1654 int err = 0;
1655 long timeo;
1656
1657 err = -EINVAL;
1658 if (sk->sk_state != TCP_ESTABLISHED)
1659 goto out;
1660
1661 err = -EOPNOTSUPP;
1662 if (flags&MSG_OOB)
1663 goto out;
1664
1665 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1666 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1667
1668 msg->msg_namelen = 0;
1669
1670 /* Lock the socket to prevent queue disordering
1671 * while sleeps in memcpy_tomsg
1672 */
1673
1674 if (!siocb->scm) {
1675 siocb->scm = &tmp_scm;
1676 memset(&tmp_scm, 0, sizeof(tmp_scm));
1677 }
1678
1679 mutex_lock(&u->readlock);
1680
1681 do
1682 {
1683 int chunk;
1684 struct sk_buff *skb;
1685
1686 skb = skb_dequeue(&sk->sk_receive_queue);
1687 if (skb==NULL)
1688 {
1689 if (copied >= target)
1690 break;
1691
1692 /*
1693 * POSIX 1003.1g mandates this order.
1694 */
1695
1696 if ((err = sock_error(sk)) != 0)
1697 break;
1698 if (sk->sk_shutdown & RCV_SHUTDOWN)
1699 break;
1700 err = -EAGAIN;
1701 if (!timeo)
1702 break;
1703 mutex_unlock(&u->readlock);
1704
1705 timeo = unix_stream_data_wait(sk, timeo);
1706
1707 if (signal_pending(current)) {
1708 err = sock_intr_errno(timeo);
1709 goto out;
1710 }
1711 mutex_lock(&u->readlock);
1712 continue;
1713 }
1714
1715 if (check_creds) {
1716 /* Never glue messages from different writers */
1717 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1718 skb_queue_head(&sk->sk_receive_queue, skb);
1719 break;
1720 }
1721 } else {
1722 /* Copy credentials */
1723 siocb->scm->creds = *UNIXCREDS(skb);
1724 check_creds = 1;
1725 }
1726
1727 /* Copy address just once */
1728 if (sunaddr)
1729 {
1730 unix_copy_addr(msg, skb->sk);
1731 sunaddr = NULL;
1732 }
1733
1734 chunk = min_t(unsigned int, skb->len, size);
1735 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1736 skb_queue_head(&sk->sk_receive_queue, skb);
1737 if (copied == 0)
1738 copied = -EFAULT;
1739 break;
1740 }
1741 copied += chunk;
1742 size -= chunk;
1743
1744 /* Mark read part of skb as used */
1745 if (!(flags & MSG_PEEK))
1746 {
1747 skb_pull(skb, chunk);
1748
1749 if (UNIXCB(skb).fp)
1750 unix_detach_fds(siocb->scm, skb);
1751
1752 /* put the skb back if we didn't use it up.. */
1753 if (skb->len)
1754 {
1755 skb_queue_head(&sk->sk_receive_queue, skb);
1756 break;
1757 }
1758
1759 kfree_skb(skb);
1760
1761 if (siocb->scm->fp)
1762 break;
1763 }
1764 else
1765 {
1766 /* It is questionable, see note in unix_dgram_recvmsg.
1767 */
1768 if (UNIXCB(skb).fp)
1769 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1770
1771 /* put message back and return */
1772 skb_queue_head(&sk->sk_receive_queue, skb);
1773 break;
1774 }
1775 } while (size);
1776
1777 mutex_unlock(&u->readlock);
1778 scm_recv(sock, msg, siocb->scm, flags);
1779 out:
1780 return copied ? : err;
1781 }
1782
1783 static int unix_shutdown(struct socket *sock, int mode)
1784 {
1785 struct sock *sk = sock->sk;
1786 struct sock *other;
1787
1788 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1789
1790 if (mode) {
1791 unix_state_wlock(sk);
1792 sk->sk_shutdown |= mode;
1793 other=unix_peer(sk);
1794 if (other)
1795 sock_hold(other);
1796 unix_state_wunlock(sk);
1797 sk->sk_state_change(sk);
1798
1799 if (other &&
1800 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1801
1802 int peer_mode = 0;
1803
1804 if (mode&RCV_SHUTDOWN)
1805 peer_mode |= SEND_SHUTDOWN;
1806 if (mode&SEND_SHUTDOWN)
1807 peer_mode |= RCV_SHUTDOWN;
1808 unix_state_wlock(other);
1809 other->sk_shutdown |= peer_mode;
1810 unix_state_wunlock(other);
1811 other->sk_state_change(other);
1812 read_lock(&other->sk_callback_lock);
1813 if (peer_mode == SHUTDOWN_MASK)
1814 sk_wake_async(other,1,POLL_HUP);
1815 else if (peer_mode & RCV_SHUTDOWN)
1816 sk_wake_async(other,1,POLL_IN);
1817 read_unlock(&other->sk_callback_lock);
1818 }
1819 if (other)
1820 sock_put(other);
1821 }
1822 return 0;
1823 }
1824
1825 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1826 {
1827 struct sock *sk = sock->sk;
1828 long amount=0;
1829 int err;
1830
1831 switch(cmd)
1832 {
1833 case SIOCOUTQ:
1834 amount = atomic_read(&sk->sk_wmem_alloc);
1835 err = put_user(amount, (int __user *)arg);
1836 break;
1837 case SIOCINQ:
1838 {
1839 struct sk_buff *skb;
1840
1841 if (sk->sk_state == TCP_LISTEN) {
1842 err = -EINVAL;
1843 break;
1844 }
1845
1846 spin_lock(&sk->sk_receive_queue.lock);
1847 if (sk->sk_type == SOCK_STREAM ||
1848 sk->sk_type == SOCK_SEQPACKET) {
1849 skb_queue_walk(&sk->sk_receive_queue, skb)
1850 amount += skb->len;
1851 } else {
1852 skb = skb_peek(&sk->sk_receive_queue);
1853 if (skb)
1854 amount=skb->len;
1855 }
1856 spin_unlock(&sk->sk_receive_queue.lock);
1857 err = put_user(amount, (int __user *)arg);
1858 break;
1859 }
1860
1861 default:
1862 err = -ENOIOCTLCMD;
1863 break;
1864 }
1865 return err;
1866 }
1867
1868 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1869 {
1870 struct sock *sk = sock->sk;
1871 unsigned int mask;
1872
1873 poll_wait(file, sk->sk_sleep, wait);
1874 mask = 0;
1875
1876 /* exceptional events? */
1877 if (sk->sk_err)
1878 mask |= POLLERR;
1879 if (sk->sk_shutdown == SHUTDOWN_MASK)
1880 mask |= POLLHUP;
1881 if (sk->sk_shutdown & RCV_SHUTDOWN)
1882 mask |= POLLRDHUP;
1883
1884 /* readable? */
1885 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1886 (sk->sk_shutdown & RCV_SHUTDOWN))
1887 mask |= POLLIN | POLLRDNORM;
1888
1889 /* Connection-based need to check for termination and startup */
1890 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
1891 mask |= POLLHUP;
1892
1893 /*
1894 * we set writable also when the other side has shut down the
1895 * connection. This prevents stuck sockets.
1896 */
1897 if (unix_writable(sk))
1898 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1899
1900 return mask;
1901 }
1902
1903
1904 #ifdef CONFIG_PROC_FS
1905 static struct sock *unix_seq_idx(int *iter, loff_t pos)
1906 {
1907 loff_t off = 0;
1908 struct sock *s;
1909
1910 for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) {
1911 if (off == pos)
1912 return s;
1913 ++off;
1914 }
1915 return NULL;
1916 }
1917
1918
1919 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
1920 {
1921 spin_lock(&unix_table_lock);
1922 return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1);
1923 }
1924
1925 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1926 {
1927 ++*pos;
1928
1929 if (v == (void *)1)
1930 return first_unix_socket(seq->private);
1931 return next_unix_socket(seq->private, v);
1932 }
1933
1934 static void unix_seq_stop(struct seq_file *seq, void *v)
1935 {
1936 spin_unlock(&unix_table_lock);
1937 }
1938
1939 static int unix_seq_show(struct seq_file *seq, void *v)
1940 {
1941
1942 if (v == (void *)1)
1943 seq_puts(seq, "Num RefCount Protocol Flags Type St "
1944 "Inode Path\n");
1945 else {
1946 struct sock *s = v;
1947 struct unix_sock *u = unix_sk(s);
1948 unix_state_rlock(s);
1949
1950 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
1951 s,
1952 atomic_read(&s->sk_refcnt),
1953 0,
1954 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
1955 s->sk_type,
1956 s->sk_socket ?
1957 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
1958 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
1959 sock_i_ino(s));
1960
1961 if (u->addr) {
1962 int i, len;
1963 seq_putc(seq, ' ');
1964
1965 i = 0;
1966 len = u->addr->len - sizeof(short);
1967 if (!UNIX_ABSTRACT(s))
1968 len--;
1969 else {
1970 seq_putc(seq, '@');
1971 i++;
1972 }
1973 for ( ; i < len; i++)
1974 seq_putc(seq, u->addr->name->sun_path[i]);
1975 }
1976 unix_state_runlock(s);
1977 seq_putc(seq, '\n');
1978 }
1979
1980 return 0;
1981 }
1982
1983 static struct seq_operations unix_seq_ops = {
1984 .start = unix_seq_start,
1985 .next = unix_seq_next,
1986 .stop = unix_seq_stop,
1987 .show = unix_seq_show,
1988 };
1989
1990
1991 static int unix_seq_open(struct inode *inode, struct file *file)
1992 {
1993 struct seq_file *seq;
1994 int rc = -ENOMEM;
1995 int *iter = kmalloc(sizeof(int), GFP_KERNEL);
1996
1997 if (!iter)
1998 goto out;
1999
2000 rc = seq_open(file, &unix_seq_ops);
2001 if (rc)
2002 goto out_kfree;
2003
2004 seq = file->private_data;
2005 seq->private = iter;
2006 *iter = 0;
2007 out:
2008 return rc;
2009 out_kfree:
2010 kfree(iter);
2011 goto out;
2012 }
2013
2014 static struct file_operations unix_seq_fops = {
2015 .owner = THIS_MODULE,
2016 .open = unix_seq_open,
2017 .read = seq_read,
2018 .llseek = seq_lseek,
2019 .release = seq_release_private,
2020 };
2021
2022 #endif
2023
2024 static struct net_proto_family unix_family_ops = {
2025 .family = PF_UNIX,
2026 .create = unix_create,
2027 .owner = THIS_MODULE,
2028 };
2029
2030 static int __init af_unix_init(void)
2031 {
2032 int rc = -1;
2033 struct sk_buff *dummy_skb;
2034
2035 if (sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)) {
2036 printk(KERN_CRIT "%s: panic\n", __FUNCTION__);
2037 goto out;
2038 }
2039
2040 rc = proto_register(&unix_proto, 1);
2041 if (rc != 0) {
2042 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2043 __FUNCTION__);
2044 goto out;
2045 }
2046
2047 sock_register(&unix_family_ops);
2048 #ifdef CONFIG_PROC_FS
2049 proc_net_fops_create("unix", 0, &unix_seq_fops);
2050 #endif
2051 unix_sysctl_register();
2052 out:
2053 return rc;
2054 }
2055
2056 static void __exit af_unix_exit(void)
2057 {
2058 sock_unregister(PF_UNIX);
2059 unix_sysctl_unregister();
2060 proc_net_remove("unix");
2061 proto_unregister(&unix_proto);
2062 }
2063
2064 module_init(af_unix_init);
2065 module_exit(af_unix_exit);
2066
2067 MODULE_LICENSE("GPL");
2068 MODULE_ALIAS_NETPROTO(PF_UNIX);
linux-next