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[POWERPC] Remove dead EEH code
[linux-2.6/libata-dev.git] / net / unix / af_unix.c
blobd70fa30d4294383f4cbdc45feec8a1df90f65a2b
1 /*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
4 * Authors: Alan Cox, <alan.cox@linux.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Version: $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $
12 *
13 * Fixes:
14 * Linus Torvalds : Assorted bug cures.
15 * Niibe Yutaka : async I/O support.
16 * Carsten Paeth : PF_UNIX check, address fixes.
17 * Alan Cox : Limit size of allocated blocks.
18 * Alan Cox : Fixed the stupid socketpair bug.
19 * Alan Cox : BSD compatibility fine tuning.
20 * Alan Cox : Fixed a bug in connect when interrupted.
21 * Alan Cox : Sorted out a proper draft version of
22 * file descriptor passing hacked up from
23 * Mike Shaver's work.
24 * Marty Leisner : Fixes to fd passing
25 * Nick Nevin : recvmsg bugfix.
26 * Alan Cox : Started proper garbage collector
27 * Heiko EiBfeldt : Missing verify_area check
28 * Alan Cox : Started POSIXisms
29 * Andreas Schwab : Replace inode by dentry for proper
30 * reference counting
31 * Kirk Petersen : Made this a module
32 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
33 * Lots of bug fixes.
34 * Alexey Kuznetosv : Repaired (I hope) bugs introduces
35 * by above two patches.
36 * Andrea Arcangeli : If possible we block in connect(2)
37 * if the max backlog of the listen socket
38 * is been reached. This won't break
39 * old apps and it will avoid huge amount
40 * of socks hashed (this for unix_gc()
41 * performances reasons).
42 * Security fix that limits the max
43 * number of socks to 2*max_files and
44 * the number of skb queueable in the
45 * dgram receiver.
46 * Artur Skawina : Hash function optimizations
47 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
48 * Malcolm Beattie : Set peercred for socketpair
49 * Michal Ostrowski : Module initialization cleanup.
50 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
51 * the core infrastructure is doing that
52 * for all net proto families now (2.5.69+)
53 *
54 *
55 * Known differences from reference BSD that was tested:
56 *
57 * [TO FIX]
58 * ECONNREFUSED is not returned from one end of a connected() socket to the
59 * other the moment one end closes.
60 * fstat() doesn't return st_dev=0, and give the blksize as high water mark
61 * and a fake inode identifier (nor the BSD first socket fstat twice bug).
62 * [NOT TO FIX]
63 * accept() returns a path name even if the connecting socket has closed
64 * in the meantime (BSD loses the path and gives up).
65 * accept() returns 0 length path for an unbound connector. BSD returns 16
66 * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
67 * socketpair(...SOCK_RAW..) doesn't panic the kernel.
68 * BSD af_unix apparently has connect forgetting to block properly.
69 * (need to check this with the POSIX spec in detail)
70 *
71 * Differences from 2.0.0-11-... (ANK)
72 * Bug fixes and improvements.
73 * - client shutdown killed server socket.
74 * - removed all useless cli/sti pairs.
75 *
76 * Semantic changes/extensions.
77 * - generic control message passing.
78 * - SCM_CREDENTIALS control message.
79 * - "Abstract" (not FS based) socket bindings.
80 * Abstract names are sequences of bytes (not zero terminated)
81 * started by 0, so that this name space does not intersect
82 * with BSD names.
83 */
84
85 #include <linux/module.h>
86 #include <linux/kernel.h>
87 #include <linux/signal.h>
88 #include <linux/sched.h>
89 #include <linux/errno.h>
90 #include <linux/string.h>
91 #include <linux/stat.h>
92 #include <linux/dcache.h>
93 #include <linux/namei.h>
94 #include <linux/socket.h>
95 #include <linux/un.h>
96 #include <linux/fcntl.h>
97 #include <linux/termios.h>
98 #include <linux/sockios.h>
99 #include <linux/net.h>
100 #include <linux/in.h>
101 #include <linux/fs.h>
102 #include <linux/slab.h>
103 #include <asm/uaccess.h>
104 #include <linux/skbuff.h>
105 #include <linux/netdevice.h>
106 #include <net/sock.h>
107 #include <net/tcp_states.h>
108 #include <net/af_unix.h>
109 #include <linux/proc_fs.h>
110 #include <linux/seq_file.h>
111 #include <net/scm.h>
112 #include <linux/init.h>
113 #include <linux/poll.h>
114 #include <linux/rtnetlink.h>
115 #include <linux/mount.h>
116 #include <net/checksum.h>
117 #include <linux/security.h>
118
119 int sysctl_unix_max_dgram_qlen __read_mostly = 10;
120
121 struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
122 DEFINE_SPINLOCK(unix_table_lock);
123 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
124
125 #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
126
127 #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
128
129 #ifdef CONFIG_SECURITY_NETWORK
130 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
131 {
132 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
133 }
134
135 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
136 {
137 scm->secid = *UNIXSID(skb);
138 }
139 #else
140 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
141 { }
142
143 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
144 { }
145 #endif /* CONFIG_SECURITY_NETWORK */
146
147 /*
148 * SMP locking strategy:
149 * hash table is protected with spinlock unix_table_lock
150 * each socket state is protected by separate rwlock.
151 */
152
153 static inline unsigned unix_hash_fold(__wsum n)
154 {
155 unsigned hash = (__force unsigned)n;
156 hash ^= hash>>16;
157 hash ^= hash>>8;
158 return hash&(UNIX_HASH_SIZE-1);
159 }
160
161 #define unix_peer(sk) (unix_sk(sk)->peer)
162
163 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
164 {
165 return unix_peer(osk) == sk;
166 }
167
168 static inline int unix_may_send(struct sock *sk, struct sock *osk)
169 {
170 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
171 }
172
173 static struct sock *unix_peer_get(struct sock *s)
174 {
175 struct sock *peer;
176
177 unix_state_lock(s);
178 peer = unix_peer(s);
179 if (peer)
180 sock_hold(peer);
181 unix_state_unlock(s);
182 return peer;
183 }
184
185 static inline void unix_release_addr(struct unix_address *addr)
186 {
187 if (atomic_dec_and_test(&addr->refcnt))
188 kfree(addr);
189 }
190
191 /*
192 * Check unix socket name:
193 * - should be not zero length.
194 * - if started by not zero, should be NULL terminated (FS object)
195 * - if started by zero, it is abstract name.
196 */
197
198 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
199 {
200 if (len <= sizeof(short) || len > sizeof(*sunaddr))
201 return -EINVAL;
202 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
203 return -EINVAL;
204 if (sunaddr->sun_path[0]) {
205 /*
206 * This may look like an off by one error but it is a bit more
207 * subtle. 108 is the longest valid AF_UNIX path for a binding.
208 * sun_path[108] doesnt as such exist. However in kernel space
209 * we are guaranteed that it is a valid memory location in our
210 * kernel address buffer.
211 */
212 ((char *)sunaddr)[len]=0;
213 len = strlen(sunaddr->sun_path)+1+sizeof(short);
214 return len;
215 }
216
217 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
218 return len;
219 }
220
221 static void __unix_remove_socket(struct sock *sk)
222 {
223 sk_del_node_init(sk);
224 }
225
226 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
227 {
228 BUG_TRAP(sk_unhashed(sk));
229 sk_add_node(sk, list);
230 }
231
232 static inline void unix_remove_socket(struct sock *sk)
233 {
234 spin_lock(&unix_table_lock);
235 __unix_remove_socket(sk);
236 spin_unlock(&unix_table_lock);
237 }
238
239 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
240 {
241 spin_lock(&unix_table_lock);
242 __unix_insert_socket(list, sk);
243 spin_unlock(&unix_table_lock);
244 }
245
246 static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname,
247 int len, int type, unsigned hash)
248 {
249 struct sock *s;
250 struct hlist_node *node;
251
252 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
253 struct unix_sock *u = unix_sk(s);
254
255 if (u->addr->len == len &&
256 !memcmp(u->addr->name, sunname, len))
257 goto found;
258 }
259 s = NULL;
260 found:
261 return s;
262 }
263
264 static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname,
265 int len, int type,
266 unsigned hash)
267 {
268 struct sock *s;
269
270 spin_lock(&unix_table_lock);
271 s = __unix_find_socket_byname(sunname, len, type, hash);
272 if (s)
273 sock_hold(s);
274 spin_unlock(&unix_table_lock);
275 return s;
276 }
277
278 static struct sock *unix_find_socket_byinode(struct inode *i)
279 {
280 struct sock *s;
281 struct hlist_node *node;
282
283 spin_lock(&unix_table_lock);
284 sk_for_each(s, node,
285 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
286 struct dentry *dentry = unix_sk(s)->dentry;
287
288 if(dentry && dentry->d_inode == i)
289 {
290 sock_hold(s);
291 goto found;
292 }
293 }
294 s = NULL;
295 found:
296 spin_unlock(&unix_table_lock);
297 return s;
298 }
299
300 static inline int unix_writable(struct sock *sk)
301 {
302 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
303 }
304
305 static void unix_write_space(struct sock *sk)
306 {
307 read_lock(&sk->sk_callback_lock);
308 if (unix_writable(sk)) {
309 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
310 wake_up_interruptible(sk->sk_sleep);
311 sk_wake_async(sk, 2, POLL_OUT);
312 }
313 read_unlock(&sk->sk_callback_lock);
314 }
315
316 /* When dgram socket disconnects (or changes its peer), we clear its receive
317 * queue of packets arrived from previous peer. First, it allows to do
318 * flow control based only on wmem_alloc; second, sk connected to peer
319 * may receive messages only from that peer. */
320 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
321 {
322 if (!skb_queue_empty(&sk->sk_receive_queue)) {
323 skb_queue_purge(&sk->sk_receive_queue);
324 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
325
326 /* If one link of bidirectional dgram pipe is disconnected,
327 * we signal error. Messages are lost. Do not make this,
328 * when peer was not connected to us.
329 */
330 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
331 other->sk_err = ECONNRESET;
332 other->sk_error_report(other);
333 }
334 }
335 }
336
337 static void unix_sock_destructor(struct sock *sk)
338 {
339 struct unix_sock *u = unix_sk(sk);
340
341 skb_queue_purge(&sk->sk_receive_queue);
342
343 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
344 BUG_TRAP(sk_unhashed(sk));
345 BUG_TRAP(!sk->sk_socket);
346 if (!sock_flag(sk, SOCK_DEAD)) {
347 printk("Attempt to release alive unix socket: %p\n", sk);
348 return;
349 }
350
351 if (u->addr)
352 unix_release_addr(u->addr);
353
354 atomic_dec(&unix_nr_socks);
355 #ifdef UNIX_REFCNT_DEBUG
356 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
357 #endif
358 }
359
360 static int unix_release_sock (struct sock *sk, int embrion)
361 {
362 struct unix_sock *u = unix_sk(sk);
363 struct dentry *dentry;
364 struct vfsmount *mnt;
365 struct sock *skpair;
366 struct sk_buff *skb;
367 int state;
368
369 unix_remove_socket(sk);
370
371 /* Clear state */
372 unix_state_lock(sk);
373 sock_orphan(sk);
374 sk->sk_shutdown = SHUTDOWN_MASK;
375 dentry = u->dentry;
376 u->dentry = NULL;
377 mnt = u->mnt;
378 u->mnt = NULL;
379 state = sk->sk_state;
380 sk->sk_state = TCP_CLOSE;
381 unix_state_unlock(sk);
382
383 wake_up_interruptible_all(&u->peer_wait);
384
385 skpair=unix_peer(sk);
386
387 if (skpair!=NULL) {
388 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
389 unix_state_lock(skpair);
390 /* No more writes */
391 skpair->sk_shutdown = SHUTDOWN_MASK;
392 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
393 skpair->sk_err = ECONNRESET;
394 unix_state_unlock(skpair);
395 skpair->sk_state_change(skpair);
396 read_lock(&skpair->sk_callback_lock);
397 sk_wake_async(skpair,1,POLL_HUP);
398 read_unlock(&skpair->sk_callback_lock);
399 }
400 sock_put(skpair); /* It may now die */
401 unix_peer(sk) = NULL;
402 }
403
404 /* Try to flush out this socket. Throw out buffers at least */
405
406 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
407 if (state==TCP_LISTEN)
408 unix_release_sock(skb->sk, 1);
409 /* passed fds are erased in the kfree_skb hook */
410 kfree_skb(skb);
411 }
412
413 if (dentry) {
414 dput(dentry);
415 mntput(mnt);
416 }
417
418 sock_put(sk);
419
420 /* ---- Socket is dead now and most probably destroyed ---- */
421
422 /*
423 * Fixme: BSD difference: In BSD all sockets connected to use get
424 * ECONNRESET and we die on the spot. In Linux we behave
425 * like files and pipes do and wait for the last
426 * dereference.
427 *
428 * Can't we simply set sock->err?
429 *
430 * What the above comment does talk about? --ANK(980817)
431 */
432
433 if (atomic_read(&unix_tot_inflight))
434 unix_gc(); /* Garbage collect fds */
435
436 return 0;
437 }
438
439 static int unix_listen(struct socket *sock, int backlog)
440 {
441 int err;
442 struct sock *sk = sock->sk;
443 struct unix_sock *u = unix_sk(sk);
444
445 err = -EOPNOTSUPP;
446 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
447 goto out; /* Only stream/seqpacket sockets accept */
448 err = -EINVAL;
449 if (!u->addr)
450 goto out; /* No listens on an unbound socket */
451 unix_state_lock(sk);
452 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
453 goto out_unlock;
454 if (backlog > sk->sk_max_ack_backlog)
455 wake_up_interruptible_all(&u->peer_wait);
456 sk->sk_max_ack_backlog = backlog;
457 sk->sk_state = TCP_LISTEN;
458 /* set credentials so connect can copy them */
459 sk->sk_peercred.pid = current->tgid;
460 sk->sk_peercred.uid = current->euid;
461 sk->sk_peercred.gid = current->egid;
462 err = 0;
463
464 out_unlock:
465 unix_state_unlock(sk);
466 out:
467 return err;
468 }
469
470 static int unix_release(struct socket *);
471 static int unix_bind(struct socket *, struct sockaddr *, int);
472 static int unix_stream_connect(struct socket *, struct sockaddr *,
473 int addr_len, int flags);
474 static int unix_socketpair(struct socket *, struct socket *);
475 static int unix_accept(struct socket *, struct socket *, int);
476 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
477 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
478 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
479 static int unix_shutdown(struct socket *, int);
480 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
481 struct msghdr *, size_t);
482 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
483 struct msghdr *, size_t, int);
484 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
485 struct msghdr *, size_t);
486 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
487 struct msghdr *, size_t, int);
488 static int unix_dgram_connect(struct socket *, struct sockaddr *,
489 int, int);
490 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
491 struct msghdr *, size_t);
492
493 static const struct proto_ops unix_stream_ops = {
494 .family = PF_UNIX,
495 .owner = THIS_MODULE,
496 .release = unix_release,
497 .bind = unix_bind,
498 .connect = unix_stream_connect,
499 .socketpair = unix_socketpair,
500 .accept = unix_accept,
501 .getname = unix_getname,
502 .poll = unix_poll,
503 .ioctl = unix_ioctl,
504 .listen = unix_listen,
505 .shutdown = unix_shutdown,
506 .setsockopt = sock_no_setsockopt,
507 .getsockopt = sock_no_getsockopt,
508 .sendmsg = unix_stream_sendmsg,
509 .recvmsg = unix_stream_recvmsg,
510 .mmap = sock_no_mmap,
511 .sendpage = sock_no_sendpage,
512 };
513
514 static const struct proto_ops unix_dgram_ops = {
515 .family = PF_UNIX,
516 .owner = THIS_MODULE,
517 .release = unix_release,
518 .bind = unix_bind,
519 .connect = unix_dgram_connect,
520 .socketpair = unix_socketpair,
521 .accept = sock_no_accept,
522 .getname = unix_getname,
523 .poll = datagram_poll,
524 .ioctl = unix_ioctl,
525 .listen = sock_no_listen,
526 .shutdown = unix_shutdown,
527 .setsockopt = sock_no_setsockopt,
528 .getsockopt = sock_no_getsockopt,
529 .sendmsg = unix_dgram_sendmsg,
530 .recvmsg = unix_dgram_recvmsg,
531 .mmap = sock_no_mmap,
532 .sendpage = sock_no_sendpage,
533 };
534
535 static const struct proto_ops unix_seqpacket_ops = {
536 .family = PF_UNIX,
537 .owner = THIS_MODULE,
538 .release = unix_release,
539 .bind = unix_bind,
540 .connect = unix_stream_connect,
541 .socketpair = unix_socketpair,
542 .accept = unix_accept,
543 .getname = unix_getname,
544 .poll = datagram_poll,
545 .ioctl = unix_ioctl,
546 .listen = unix_listen,
547 .shutdown = unix_shutdown,
548 .setsockopt = sock_no_setsockopt,
549 .getsockopt = sock_no_getsockopt,
550 .sendmsg = unix_seqpacket_sendmsg,
551 .recvmsg = unix_dgram_recvmsg,
552 .mmap = sock_no_mmap,
553 .sendpage = sock_no_sendpage,
554 };
555
556 static struct proto unix_proto = {
557 .name = "UNIX",
558 .owner = THIS_MODULE,
559 .obj_size = sizeof(struct unix_sock),
560 };
561
562 /*
563 * AF_UNIX sockets do not interact with hardware, hence they
564 * dont trigger interrupts - so it's safe for them to have
565 * bh-unsafe locking for their sk_receive_queue.lock. Split off
566 * this special lock-class by reinitializing the spinlock key:
567 */
568 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
569
570 static struct sock * unix_create1(struct socket *sock)
571 {
572 struct sock *sk = NULL;
573 struct unix_sock *u;
574
575 if (atomic_read(&unix_nr_socks) >= 2*get_max_files())
576 goto out;
577
578 sk = sk_alloc(PF_UNIX, GFP_KERNEL, &unix_proto, 1);
579 if (!sk)
580 goto out;
581
582 atomic_inc(&unix_nr_socks);
583
584 sock_init_data(sock,sk);
585 lockdep_set_class(&sk->sk_receive_queue.lock,
586 &af_unix_sk_receive_queue_lock_key);
587
588 sk->sk_write_space = unix_write_space;
589 sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen;
590 sk->sk_destruct = unix_sock_destructor;
591 u = unix_sk(sk);
592 u->dentry = NULL;
593 u->mnt = NULL;
594 spin_lock_init(&u->lock);
595 atomic_set(&u->inflight, sock ? 0 : -1);
596 mutex_init(&u->readlock); /* single task reading lock */
597 init_waitqueue_head(&u->peer_wait);
598 unix_insert_socket(unix_sockets_unbound, sk);
599 out:
600 return sk;
601 }
602
603 static int unix_create(struct socket *sock, int protocol)
604 {
605 if (protocol && protocol != PF_UNIX)
606 return -EPROTONOSUPPORT;
607
608 sock->state = SS_UNCONNECTED;
609
610 switch (sock->type) {
611 case SOCK_STREAM:
612 sock->ops = &unix_stream_ops;
613 break;
614 /*
615 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
616 * nothing uses it.
617 */
618 case SOCK_RAW:
619 sock->type=SOCK_DGRAM;
620 case SOCK_DGRAM:
621 sock->ops = &unix_dgram_ops;
622 break;
623 case SOCK_SEQPACKET:
624 sock->ops = &unix_seqpacket_ops;
625 break;
626 default:
627 return -ESOCKTNOSUPPORT;
628 }
629
630 return unix_create1(sock) ? 0 : -ENOMEM;
631 }
632
633 static int unix_release(struct socket *sock)
634 {
635 struct sock *sk = sock->sk;
636
637 if (!sk)
638 return 0;
639
640 sock->sk = NULL;
641
642 return unix_release_sock (sk, 0);
643 }
644
645 static int unix_autobind(struct socket *sock)
646 {
647 struct sock *sk = sock->sk;
648 struct unix_sock *u = unix_sk(sk);
649 static u32 ordernum = 1;
650 struct unix_address * addr;
651 int err;
652
653 mutex_lock(&u->readlock);
654
655 err = 0;
656 if (u->addr)
657 goto out;
658
659 err = -ENOMEM;
660 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
661 if (!addr)
662 goto out;
663
664 addr->name->sun_family = AF_UNIX;
665 atomic_set(&addr->refcnt, 1);
666
667 retry:
668 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
669 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
670
671 spin_lock(&unix_table_lock);
672 ordernum = (ordernum+1)&0xFFFFF;
673
674 if (__unix_find_socket_byname(addr->name, addr->len, sock->type,
675 addr->hash)) {
676 spin_unlock(&unix_table_lock);
677 /* Sanity yield. It is unusual case, but yet... */
678 if (!(ordernum&0xFF))
679 yield();
680 goto retry;
681 }
682 addr->hash ^= sk->sk_type;
683
684 __unix_remove_socket(sk);
685 u->addr = addr;
686 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
687 spin_unlock(&unix_table_lock);
688 err = 0;
689
690 out: mutex_unlock(&u->readlock);
691 return err;
692 }
693
694 static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
695 int type, unsigned hash, int *error)
696 {
697 struct sock *u;
698 struct nameidata nd;
699 int err = 0;
700
701 if (sunname->sun_path[0]) {
702 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
703 if (err)
704 goto fail;
705 err = vfs_permission(&nd, MAY_WRITE);
706 if (err)
707 goto put_fail;
708
709 err = -ECONNREFUSED;
710 if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
711 goto put_fail;
712 u=unix_find_socket_byinode(nd.dentry->d_inode);
713 if (!u)
714 goto put_fail;
715
716 if (u->sk_type == type)
717 touch_atime(nd.mnt, nd.dentry);
718
719 path_release(&nd);
720
721 err=-EPROTOTYPE;
722 if (u->sk_type != type) {
723 sock_put(u);
724 goto fail;
725 }
726 } else {
727 err = -ECONNREFUSED;
728 u=unix_find_socket_byname(sunname, len, type, hash);
729 if (u) {
730 struct dentry *dentry;
731 dentry = unix_sk(u)->dentry;
732 if (dentry)
733 touch_atime(unix_sk(u)->mnt, dentry);
734 } else
735 goto fail;
736 }
737 return u;
738
739 put_fail:
740 path_release(&nd);
741 fail:
742 *error=err;
743 return NULL;
744 }
745
746
747 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
748 {
749 struct sock *sk = sock->sk;
750 struct unix_sock *u = unix_sk(sk);
751 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
752 struct dentry * dentry = NULL;
753 struct nameidata nd;
754 int err;
755 unsigned hash;
756 struct unix_address *addr;
757 struct hlist_head *list;
758
759 err = -EINVAL;
760 if (sunaddr->sun_family != AF_UNIX)
761 goto out;
762
763 if (addr_len==sizeof(short)) {
764 err = unix_autobind(sock);
765 goto out;
766 }
767
768 err = unix_mkname(sunaddr, addr_len, &hash);
769 if (err < 0)
770 goto out;
771 addr_len = err;
772
773 mutex_lock(&u->readlock);
774
775 err = -EINVAL;
776 if (u->addr)
777 goto out_up;
778
779 err = -ENOMEM;
780 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
781 if (!addr)
782 goto out_up;
783
784 memcpy(addr->name, sunaddr, addr_len);
785 addr->len = addr_len;
786 addr->hash = hash ^ sk->sk_type;
787 atomic_set(&addr->refcnt, 1);
788
789 if (sunaddr->sun_path[0]) {
790 unsigned int mode;
791 err = 0;
792 /*
793 * Get the parent directory, calculate the hash for last
794 * component.
795 */
796 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
797 if (err)
798 goto out_mknod_parent;
799
800 dentry = lookup_create(&nd, 0);
801 err = PTR_ERR(dentry);
802 if (IS_ERR(dentry))
803 goto out_mknod_unlock;
804
805 /*
806 * All right, let's create it.
807 */
808 mode = S_IFSOCK |
809 (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
810 err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
811 if (err)
812 goto out_mknod_dput;
813 mutex_unlock(&nd.dentry->d_inode->i_mutex);
814 dput(nd.dentry);
815 nd.dentry = dentry;
816
817 addr->hash = UNIX_HASH_SIZE;
818 }
819
820 spin_lock(&unix_table_lock);
821
822 if (!sunaddr->sun_path[0]) {
823 err = -EADDRINUSE;
824 if (__unix_find_socket_byname(sunaddr, addr_len,
825 sk->sk_type, hash)) {
826 unix_release_addr(addr);
827 goto out_unlock;
828 }
829
830 list = &unix_socket_table[addr->hash];
831 } else {
832 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
833 u->dentry = nd.dentry;
834 u->mnt = nd.mnt;
835 }
836
837 err = 0;
838 __unix_remove_socket(sk);
839 u->addr = addr;
840 __unix_insert_socket(list, sk);
841
842 out_unlock:
843 spin_unlock(&unix_table_lock);
844 out_up:
845 mutex_unlock(&u->readlock);
846 out:
847 return err;
848
849 out_mknod_dput:
850 dput(dentry);
851 out_mknod_unlock:
852 mutex_unlock(&nd.dentry->d_inode->i_mutex);
853 path_release(&nd);
854 out_mknod_parent:
855 if (err==-EEXIST)
856 err=-EADDRINUSE;
857 unix_release_addr(addr);
858 goto out_up;
859 }
860
861 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
862 {
863 if (unlikely(sk1 == sk2) || !sk2) {
864 unix_state_lock(sk1);
865 return;
866 }
867 if (sk1 < sk2) {
868 unix_state_lock(sk1);
869 unix_state_lock_nested(sk2);
870 } else {
871 unix_state_lock(sk2);
872 unix_state_lock_nested(sk1);
873 }
874 }
875
876 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
877 {
878 if (unlikely(sk1 == sk2) || !sk2) {
879 unix_state_unlock(sk1);
880 return;
881 }
882 unix_state_unlock(sk1);
883 unix_state_unlock(sk2);
884 }
885
886 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
887 int alen, int flags)
888 {
889 struct sock *sk = sock->sk;
890 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
891 struct sock *other;
892 unsigned hash;
893 int err;
894
895 if (addr->sa_family != AF_UNSPEC) {
896 err = unix_mkname(sunaddr, alen, &hash);
897 if (err < 0)
898 goto out;
899 alen = err;
900
901 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
902 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
903 goto out;
904
905 restart:
906 other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
907 if (!other)
908 goto out;
909
910 unix_state_double_lock(sk, other);
911
912 /* Apparently VFS overslept socket death. Retry. */
913 if (sock_flag(other, SOCK_DEAD)) {
914 unix_state_double_unlock(sk, other);
915 sock_put(other);
916 goto restart;
917 }
918
919 err = -EPERM;
920 if (!unix_may_send(sk, other))
921 goto out_unlock;
922
923 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
924 if (err)
925 goto out_unlock;
926
927 } else {
928 /*
929 * 1003.1g breaking connected state with AF_UNSPEC
930 */
931 other = NULL;
932 unix_state_double_lock(sk, other);
933 }
934
935 /*
936 * If it was connected, reconnect.
937 */
938 if (unix_peer(sk)) {
939 struct sock *old_peer = unix_peer(sk);
940 unix_peer(sk)=other;
941 unix_state_double_unlock(sk, other);
942
943 if (other != old_peer)
944 unix_dgram_disconnected(sk, old_peer);
945 sock_put(old_peer);
946 } else {
947 unix_peer(sk)=other;
948 unix_state_double_unlock(sk, other);
949 }
950 return 0;
951
952 out_unlock:
953 unix_state_double_unlock(sk, other);
954 sock_put(other);
955 out:
956 return err;
957 }
958
959 static long unix_wait_for_peer(struct sock *other, long timeo)
960 {
961 struct unix_sock *u = unix_sk(other);
962 int sched;
963 DEFINE_WAIT(wait);
964
965 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
966
967 sched = !sock_flag(other, SOCK_DEAD) &&
968 !(other->sk_shutdown & RCV_SHUTDOWN) &&
969 (skb_queue_len(&other->sk_receive_queue) >
970 other->sk_max_ack_backlog);
971
972 unix_state_unlock(other);
973
974 if (sched)
975 timeo = schedule_timeout(timeo);
976
977 finish_wait(&u->peer_wait, &wait);
978 return timeo;
979 }
980
981 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
982 int addr_len, int flags)
983 {
984 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
985 struct sock *sk = sock->sk;
986 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
987 struct sock *newsk = NULL;
988 struct sock *other = NULL;
989 struct sk_buff *skb = NULL;
990 unsigned hash;
991 int st;
992 int err;
993 long timeo;
994
995 err = unix_mkname(sunaddr, addr_len, &hash);
996 if (err < 0)
997 goto out;
998 addr_len = err;
999
1000 if (test_bit(SOCK_PASSCRED, &sock->flags)
1001 && !u->addr && (err = unix_autobind(sock)) != 0)
1002 goto out;
1003
1004 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1005
1006 /* First of all allocate resources.
1007 If we will make it after state is locked,
1008 we will have to recheck all again in any case.
1009 */
1010
1011 err = -ENOMEM;
1012
1013 /* create new sock for complete connection */
1014 newsk = unix_create1(NULL);
1015 if (newsk == NULL)
1016 goto out;
1017
1018 /* Allocate skb for sending to listening sock */
1019 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1020 if (skb == NULL)
1021 goto out;
1022
1023 restart:
1024 /* Find listening sock. */
1025 other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err);
1026 if (!other)
1027 goto out;
1028
1029 /* Latch state of peer */
1030 unix_state_lock(other);
1031
1032 /* Apparently VFS overslept socket death. Retry. */
1033 if (sock_flag(other, SOCK_DEAD)) {
1034 unix_state_unlock(other);
1035 sock_put(other);
1036 goto restart;
1037 }
1038
1039 err = -ECONNREFUSED;
1040 if (other->sk_state != TCP_LISTEN)
1041 goto out_unlock;
1042
1043 if (skb_queue_len(&other->sk_receive_queue) >
1044 other->sk_max_ack_backlog) {
1045 err = -EAGAIN;
1046 if (!timeo)
1047 goto out_unlock;
1048
1049 timeo = unix_wait_for_peer(other, timeo);
1050
1051 err = sock_intr_errno(timeo);
1052 if (signal_pending(current))
1053 goto out;
1054 sock_put(other);
1055 goto restart;
1056 }
1057
1058 /* Latch our state.
1059
1060 It is tricky place. We need to grab write lock and cannot
1061 drop lock on peer. It is dangerous because deadlock is
1062 possible. Connect to self case and simultaneous
1063 attempt to connect are eliminated by checking socket
1064 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1065 check this before attempt to grab lock.
1066
1067 Well, and we have to recheck the state after socket locked.
1068 */
1069 st = sk->sk_state;
1070
1071 switch (st) {
1072 case TCP_CLOSE:
1073 /* This is ok... continue with connect */
1074 break;
1075 case TCP_ESTABLISHED:
1076 /* Socket is already connected */
1077 err = -EISCONN;
1078 goto out_unlock;
1079 default:
1080 err = -EINVAL;
1081 goto out_unlock;
1082 }
1083
1084 unix_state_lock_nested(sk);
1085
1086 if (sk->sk_state != st) {
1087 unix_state_unlock(sk);
1088 unix_state_unlock(other);
1089 sock_put(other);
1090 goto restart;
1091 }
1092
1093 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1094 if (err) {
1095 unix_state_unlock(sk);
1096 goto out_unlock;
1097 }
1098
1099 /* The way is open! Fastly set all the necessary fields... */
1100
1101 sock_hold(sk);
1102 unix_peer(newsk) = sk;
1103 newsk->sk_state = TCP_ESTABLISHED;
1104 newsk->sk_type = sk->sk_type;
1105 newsk->sk_peercred.pid = current->tgid;
1106 newsk->sk_peercred.uid = current->euid;
1107 newsk->sk_peercred.gid = current->egid;
1108 newu = unix_sk(newsk);
1109 newsk->sk_sleep = &newu->peer_wait;
1110 otheru = unix_sk(other);
1111
1112 /* copy address information from listening to new sock*/
1113 if (otheru->addr) {
1114 atomic_inc(&otheru->addr->refcnt);
1115 newu->addr = otheru->addr;
1116 }
1117 if (otheru->dentry) {
1118 newu->dentry = dget(otheru->dentry);
1119 newu->mnt = mntget(otheru->mnt);
1120 }
1121
1122 /* Set credentials */
1123 sk->sk_peercred = other->sk_peercred;
1124
1125 sock->state = SS_CONNECTED;
1126 sk->sk_state = TCP_ESTABLISHED;
1127 sock_hold(newsk);
1128
1129 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1130 unix_peer(sk) = newsk;
1131
1132 unix_state_unlock(sk);
1133
1134 /* take ten and and send info to listening sock */
1135 spin_lock(&other->sk_receive_queue.lock);
1136 __skb_queue_tail(&other->sk_receive_queue, skb);
1137 /* Undo artificially decreased inflight after embrion
1138 * is installed to listening socket. */
1139 atomic_inc(&newu->inflight);
1140 spin_unlock(&other->sk_receive_queue.lock);
1141 unix_state_unlock(other);
1142 other->sk_data_ready(other, 0);
1143 sock_put(other);
1144 return 0;
1145
1146 out_unlock:
1147 if (other)
1148 unix_state_unlock(other);
1149
1150 out:
1151 if (skb)
1152 kfree_skb(skb);
1153 if (newsk)
1154 unix_release_sock(newsk, 0);
1155 if (other)
1156 sock_put(other);
1157 return err;
1158 }
1159
1160 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1161 {
1162 struct sock *ska=socka->sk, *skb = sockb->sk;
1163
1164 /* Join our sockets back to back */
1165 sock_hold(ska);
1166 sock_hold(skb);
1167 unix_peer(ska)=skb;
1168 unix_peer(skb)=ska;
1169 ska->sk_peercred.pid = skb->sk_peercred.pid = current->tgid;
1170 ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid;
1171 ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid;
1172
1173 if (ska->sk_type != SOCK_DGRAM) {
1174 ska->sk_state = TCP_ESTABLISHED;
1175 skb->sk_state = TCP_ESTABLISHED;
1176 socka->state = SS_CONNECTED;
1177 sockb->state = SS_CONNECTED;
1178 }
1179 return 0;
1180 }
1181
1182 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1183 {
1184 struct sock *sk = sock->sk;
1185 struct sock *tsk;
1186 struct sk_buff *skb;
1187 int err;
1188
1189 err = -EOPNOTSUPP;
1190 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1191 goto out;
1192
1193 err = -EINVAL;
1194 if (sk->sk_state != TCP_LISTEN)
1195 goto out;
1196
1197 /* If socket state is TCP_LISTEN it cannot change (for now...),
1198 * so that no locks are necessary.
1199 */
1200
1201 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1202 if (!skb) {
1203 /* This means receive shutdown. */
1204 if (err == 0)
1205 err = -EINVAL;
1206 goto out;
1207 }
1208
1209 tsk = skb->sk;
1210 skb_free_datagram(sk, skb);
1211 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1212
1213 /* attach accepted sock to socket */
1214 unix_state_lock(tsk);
1215 newsock->state = SS_CONNECTED;
1216 sock_graft(tsk, newsock);
1217 unix_state_unlock(tsk);
1218 return 0;
1219
1220 out:
1221 return err;
1222 }
1223
1224
1225 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1226 {
1227 struct sock *sk = sock->sk;
1228 struct unix_sock *u;
1229 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1230 int err = 0;
1231
1232 if (peer) {
1233 sk = unix_peer_get(sk);
1234
1235 err = -ENOTCONN;
1236 if (!sk)
1237 goto out;
1238 err = 0;
1239 } else {
1240 sock_hold(sk);
1241 }
1242
1243 u = unix_sk(sk);
1244 unix_state_lock(sk);
1245 if (!u->addr) {
1246 sunaddr->sun_family = AF_UNIX;
1247 sunaddr->sun_path[0] = 0;
1248 *uaddr_len = sizeof(short);
1249 } else {
1250 struct unix_address *addr = u->addr;
1251
1252 *uaddr_len = addr->len;
1253 memcpy(sunaddr, addr->name, *uaddr_len);
1254 }
1255 unix_state_unlock(sk);
1256 sock_put(sk);
1257 out:
1258 return err;
1259 }
1260
1261 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1262 {
1263 int i;
1264
1265 scm->fp = UNIXCB(skb).fp;
1266 skb->destructor = sock_wfree;
1267 UNIXCB(skb).fp = NULL;
1268
1269 for (i=scm->fp->count-1; i>=0; i--)
1270 unix_notinflight(scm->fp->fp[i]);
1271 }
1272
1273 static void unix_destruct_fds(struct sk_buff *skb)
1274 {
1275 struct scm_cookie scm;
1276 memset(&scm, 0, sizeof(scm));
1277 unix_detach_fds(&scm, skb);
1278
1279 /* Alas, it calls VFS */
1280 /* So fscking what? fput() had been SMP-safe since the last Summer */
1281 scm_destroy(&scm);
1282 sock_wfree(skb);
1283 }
1284
1285 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1286 {
1287 int i;
1288 for (i=scm->fp->count-1; i>=0; i--)
1289 unix_inflight(scm->fp->fp[i]);
1290 UNIXCB(skb).fp = scm->fp;
1291 skb->destructor = unix_destruct_fds;
1292 scm->fp = NULL;
1293 }
1294
1295 /*
1296 * Send AF_UNIX data.
1297 */
1298
1299 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1300 struct msghdr *msg, size_t len)
1301 {
1302 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1303 struct sock *sk = sock->sk;
1304 struct unix_sock *u = unix_sk(sk);
1305 struct sockaddr_un *sunaddr=msg->msg_name;
1306 struct sock *other = NULL;
1307 int namelen = 0; /* fake GCC */
1308 int err;
1309 unsigned hash;
1310 struct sk_buff *skb;
1311 long timeo;
1312 struct scm_cookie tmp_scm;
1313
1314 if (NULL == siocb->scm)
1315 siocb->scm = &tmp_scm;
1316 err = scm_send(sock, msg, siocb->scm);
1317 if (err < 0)
1318 return err;
1319
1320 err = -EOPNOTSUPP;
1321 if (msg->msg_flags&MSG_OOB)
1322 goto out;
1323
1324 if (msg->msg_namelen) {
1325 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1326 if (err < 0)
1327 goto out;
1328 namelen = err;
1329 } else {
1330 sunaddr = NULL;
1331 err = -ENOTCONN;
1332 other = unix_peer_get(sk);
1333 if (!other)
1334 goto out;
1335 }
1336
1337 if (test_bit(SOCK_PASSCRED, &sock->flags)
1338 && !u->addr && (err = unix_autobind(sock)) != 0)
1339 goto out;
1340
1341 err = -EMSGSIZE;
1342 if (len > sk->sk_sndbuf - 32)
1343 goto out;
1344
1345 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1346 if (skb==NULL)
1347 goto out;
1348
1349 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1350 if (siocb->scm->fp)
1351 unix_attach_fds(siocb->scm, skb);
1352 unix_get_secdata(siocb->scm, skb);
1353
1354 skb_reset_transport_header(skb);
1355 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1356 if (err)
1357 goto out_free;
1358
1359 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1360
1361 restart:
1362 if (!other) {
1363 err = -ECONNRESET;
1364 if (sunaddr == NULL)
1365 goto out_free;
1366
1367 other = unix_find_other(sunaddr, namelen, sk->sk_type,
1368 hash, &err);
1369 if (other==NULL)
1370 goto out_free;
1371 }
1372
1373 unix_state_lock(other);
1374 err = -EPERM;
1375 if (!unix_may_send(sk, other))
1376 goto out_unlock;
1377
1378 if (sock_flag(other, SOCK_DEAD)) {
1379 /*
1380 * Check with 1003.1g - what should
1381 * datagram error
1382 */
1383 unix_state_unlock(other);
1384 sock_put(other);
1385
1386 err = 0;
1387 unix_state_lock(sk);
1388 if (unix_peer(sk) == other) {
1389 unix_peer(sk)=NULL;
1390 unix_state_unlock(sk);
1391
1392 unix_dgram_disconnected(sk, other);
1393 sock_put(other);
1394 err = -ECONNREFUSED;
1395 } else {
1396 unix_state_unlock(sk);
1397 }
1398
1399 other = NULL;
1400 if (err)
1401 goto out_free;
1402 goto restart;
1403 }
1404
1405 err = -EPIPE;
1406 if (other->sk_shutdown & RCV_SHUTDOWN)
1407 goto out_unlock;
1408
1409 if (sk->sk_type != SOCK_SEQPACKET) {
1410 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1411 if (err)
1412 goto out_unlock;
1413 }
1414
1415 if (unix_peer(other) != sk &&
1416 (skb_queue_len(&other->sk_receive_queue) >
1417 other->sk_max_ack_backlog)) {
1418 if (!timeo) {
1419 err = -EAGAIN;
1420 goto out_unlock;
1421 }
1422
1423 timeo = unix_wait_for_peer(other, timeo);
1424
1425 err = sock_intr_errno(timeo);
1426 if (signal_pending(current))
1427 goto out_free;
1428
1429 goto restart;
1430 }
1431
1432 skb_queue_tail(&other->sk_receive_queue, skb);
1433 unix_state_unlock(other);
1434 other->sk_data_ready(other, len);
1435 sock_put(other);
1436 scm_destroy(siocb->scm);
1437 return len;
1438
1439 out_unlock:
1440 unix_state_unlock(other);
1441 out_free:
1442 kfree_skb(skb);
1443 out:
1444 if (other)
1445 sock_put(other);
1446 scm_destroy(siocb->scm);
1447 return err;
1448 }
1449
1450
1451 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1452 struct msghdr *msg, size_t len)
1453 {
1454 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1455 struct sock *sk = sock->sk;
1456 struct sock *other = NULL;
1457 struct sockaddr_un *sunaddr=msg->msg_name;
1458 int err,size;
1459 struct sk_buff *skb;
1460 int sent=0;
1461 struct scm_cookie tmp_scm;
1462
1463 if (NULL == siocb->scm)
1464 siocb->scm = &tmp_scm;
1465 err = scm_send(sock, msg, siocb->scm);
1466 if (err < 0)
1467 return err;
1468
1469 err = -EOPNOTSUPP;
1470 if (msg->msg_flags&MSG_OOB)
1471 goto out_err;
1472
1473 if (msg->msg_namelen) {
1474 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1475 goto out_err;
1476 } else {
1477 sunaddr = NULL;
1478 err = -ENOTCONN;
1479 other = unix_peer(sk);
1480 if (!other)
1481 goto out_err;
1482 }
1483
1484 if (sk->sk_shutdown & SEND_SHUTDOWN)
1485 goto pipe_err;
1486
1487 while(sent < len)
1488 {
1489 /*
1490 * Optimisation for the fact that under 0.01% of X
1491 * messages typically need breaking up.
1492 */
1493
1494 size = len-sent;
1495
1496 /* Keep two messages in the pipe so it schedules better */
1497 if (size > ((sk->sk_sndbuf >> 1) - 64))
1498 size = (sk->sk_sndbuf >> 1) - 64;
1499
1500 if (size > SKB_MAX_ALLOC)
1501 size = SKB_MAX_ALLOC;
1502
1503 /*
1504 * Grab a buffer
1505 */
1506
1507 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1508
1509 if (skb==NULL)
1510 goto out_err;
1511
1512 /*
1513 * If you pass two values to the sock_alloc_send_skb
1514 * it tries to grab the large buffer with GFP_NOFS
1515 * (which can fail easily), and if it fails grab the
1516 * fallback size buffer which is under a page and will
1517 * succeed. [Alan]
1518 */
1519 size = min_t(int, size, skb_tailroom(skb));
1520
1521 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1522 if (siocb->scm->fp)
1523 unix_attach_fds(siocb->scm, skb);
1524
1525 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1526 kfree_skb(skb);
1527 goto out_err;
1528 }
1529
1530 unix_state_lock(other);
1531
1532 if (sock_flag(other, SOCK_DEAD) ||
1533 (other->sk_shutdown & RCV_SHUTDOWN))
1534 goto pipe_err_free;
1535
1536 skb_queue_tail(&other->sk_receive_queue, skb);
1537 unix_state_unlock(other);
1538 other->sk_data_ready(other, size);
1539 sent+=size;
1540 }
1541
1542 scm_destroy(siocb->scm);
1543 siocb->scm = NULL;
1544
1545 return sent;
1546
1547 pipe_err_free:
1548 unix_state_unlock(other);
1549 kfree_skb(skb);
1550 pipe_err:
1551 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1552 send_sig(SIGPIPE,current,0);
1553 err = -EPIPE;
1554 out_err:
1555 scm_destroy(siocb->scm);
1556 siocb->scm = NULL;
1557 return sent ? : err;
1558 }
1559
1560 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1561 struct msghdr *msg, size_t len)
1562 {
1563 int err;
1564 struct sock *sk = sock->sk;
1565
1566 err = sock_error(sk);
1567 if (err)
1568 return err;
1569
1570 if (sk->sk_state != TCP_ESTABLISHED)
1571 return -ENOTCONN;
1572
1573 if (msg->msg_namelen)
1574 msg->msg_namelen = 0;
1575
1576 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1577 }
1578
1579 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1580 {
1581 struct unix_sock *u = unix_sk(sk);
1582
1583 msg->msg_namelen = 0;
1584 if (u->addr) {
1585 msg->msg_namelen = u->addr->len;
1586 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1587 }
1588 }
1589
1590 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1591 struct msghdr *msg, size_t size,
1592 int flags)
1593 {
1594 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1595 struct scm_cookie tmp_scm;
1596 struct sock *sk = sock->sk;
1597 struct unix_sock *u = unix_sk(sk);
1598 int noblock = flags & MSG_DONTWAIT;
1599 struct sk_buff *skb;
1600 int err;
1601
1602 err = -EOPNOTSUPP;
1603 if (flags&MSG_OOB)
1604 goto out;
1605
1606 msg->msg_namelen = 0;
1607
1608 mutex_lock(&u->readlock);
1609
1610 skb = skb_recv_datagram(sk, flags, noblock, &err);
1611 if (!skb)
1612 goto out_unlock;
1613
1614 wake_up_interruptible(&u->peer_wait);
1615
1616 if (msg->msg_name)
1617 unix_copy_addr(msg, skb->sk);
1618
1619 if (size > skb->len)
1620 size = skb->len;
1621 else if (size < skb->len)
1622 msg->msg_flags |= MSG_TRUNC;
1623
1624 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1625 if (err)
1626 goto out_free;
1627
1628 if (!siocb->scm) {
1629 siocb->scm = &tmp_scm;
1630 memset(&tmp_scm, 0, sizeof(tmp_scm));
1631 }
1632 siocb->scm->creds = *UNIXCREDS(skb);
1633 unix_set_secdata(siocb->scm, skb);
1634
1635 if (!(flags & MSG_PEEK))
1636 {
1637 if (UNIXCB(skb).fp)
1638 unix_detach_fds(siocb->scm, skb);
1639 }
1640 else
1641 {
1642 /* It is questionable: on PEEK we could:
1643 - do not return fds - good, but too simple 8)
1644 - return fds, and do not return them on read (old strategy,
1645 apparently wrong)
1646 - clone fds (I chose it for now, it is the most universal
1647 solution)
1648
1649 POSIX 1003.1g does not actually define this clearly
1650 at all. POSIX 1003.1g doesn't define a lot of things
1651 clearly however!
1652
1653 */
1654 if (UNIXCB(skb).fp)
1655 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1656 }
1657 err = size;
1658
1659 scm_recv(sock, msg, siocb->scm, flags);
1660
1661 out_free:
1662 skb_free_datagram(sk,skb);
1663 out_unlock:
1664 mutex_unlock(&u->readlock);
1665 out:
1666 return err;
1667 }
1668
1669 /*
1670 * Sleep until data has arrive. But check for races..
1671 */
1672
1673 static long unix_stream_data_wait(struct sock * sk, long timeo)
1674 {
1675 DEFINE_WAIT(wait);
1676
1677 unix_state_lock(sk);
1678
1679 for (;;) {
1680 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1681
1682 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1683 sk->sk_err ||
1684 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1685 signal_pending(current) ||
1686 !timeo)
1687 break;
1688
1689 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1690 unix_state_unlock(sk);
1691 timeo = schedule_timeout(timeo);
1692 unix_state_lock(sk);
1693 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1694 }
1695
1696 finish_wait(sk->sk_sleep, &wait);
1697 unix_state_unlock(sk);
1698 return timeo;
1699 }
1700
1701
1702
1703 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1704 struct msghdr *msg, size_t size,
1705 int flags)
1706 {
1707 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1708 struct scm_cookie tmp_scm;
1709 struct sock *sk = sock->sk;
1710 struct unix_sock *u = unix_sk(sk);
1711 struct sockaddr_un *sunaddr=msg->msg_name;
1712 int copied = 0;
1713 int check_creds = 0;
1714 int target;
1715 int err = 0;
1716 long timeo;
1717
1718 err = -EINVAL;
1719 if (sk->sk_state != TCP_ESTABLISHED)
1720 goto out;
1721
1722 err = -EOPNOTSUPP;
1723 if (flags&MSG_OOB)
1724 goto out;
1725
1726 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1727 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1728
1729 msg->msg_namelen = 0;
1730
1731 /* Lock the socket to prevent queue disordering
1732 * while sleeps in memcpy_tomsg
1733 */
1734
1735 if (!siocb->scm) {
1736 siocb->scm = &tmp_scm;
1737 memset(&tmp_scm, 0, sizeof(tmp_scm));
1738 }
1739
1740 mutex_lock(&u->readlock);
1741
1742 do
1743 {
1744 int chunk;
1745 struct sk_buff *skb;
1746
1747 unix_state_lock(sk);
1748 skb = skb_dequeue(&sk->sk_receive_queue);
1749 if (skb==NULL)
1750 {
1751 if (copied >= target)
1752 goto unlock;
1753
1754 /*
1755 * POSIX 1003.1g mandates this order.
1756 */
1757
1758 if ((err = sock_error(sk)) != 0)
1759 goto unlock;
1760 if (sk->sk_shutdown & RCV_SHUTDOWN)
1761 goto unlock;
1762
1763 unix_state_unlock(sk);
1764 err = -EAGAIN;
1765 if (!timeo)
1766 break;
1767 mutex_unlock(&u->readlock);
1768
1769 timeo = unix_stream_data_wait(sk, timeo);
1770
1771 if (signal_pending(current)) {
1772 err = sock_intr_errno(timeo);
1773 goto out;
1774 }
1775 mutex_lock(&u->readlock);
1776 continue;
1777 unlock:
1778 unix_state_unlock(sk);
1779 break;
1780 }
1781 unix_state_unlock(sk);
1782
1783 if (check_creds) {
1784 /* Never glue messages from different writers */
1785 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1786 skb_queue_head(&sk->sk_receive_queue, skb);
1787 break;
1788 }
1789 } else {
1790 /* Copy credentials */
1791 siocb->scm->creds = *UNIXCREDS(skb);
1792 check_creds = 1;
1793 }
1794
1795 /* Copy address just once */
1796 if (sunaddr)
1797 {
1798 unix_copy_addr(msg, skb->sk);
1799 sunaddr = NULL;
1800 }
1801
1802 chunk = min_t(unsigned int, skb->len, size);
1803 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1804 skb_queue_head(&sk->sk_receive_queue, skb);
1805 if (copied == 0)
1806 copied = -EFAULT;
1807 break;
1808 }
1809 copied += chunk;
1810 size -= chunk;
1811
1812 /* Mark read part of skb as used */
1813 if (!(flags & MSG_PEEK))
1814 {
1815 skb_pull(skb, chunk);
1816
1817 if (UNIXCB(skb).fp)
1818 unix_detach_fds(siocb->scm, skb);
1819
1820 /* put the skb back if we didn't use it up.. */
1821 if (skb->len)
1822 {
1823 skb_queue_head(&sk->sk_receive_queue, skb);
1824 break;
1825 }
1826
1827 kfree_skb(skb);
1828
1829 if (siocb->scm->fp)
1830 break;
1831 }
1832 else
1833 {
1834 /* It is questionable, see note in unix_dgram_recvmsg.
1835 */
1836 if (UNIXCB(skb).fp)
1837 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1838
1839 /* put message back and return */
1840 skb_queue_head(&sk->sk_receive_queue, skb);
1841 break;
1842 }
1843 } while (size);
1844
1845 mutex_unlock(&u->readlock);
1846 scm_recv(sock, msg, siocb->scm, flags);
1847 out:
1848 return copied ? : err;
1849 }
1850
1851 static int unix_shutdown(struct socket *sock, int mode)
1852 {
1853 struct sock *sk = sock->sk;
1854 struct sock *other;
1855
1856 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1857
1858 if (mode) {
1859 unix_state_lock(sk);
1860 sk->sk_shutdown |= mode;
1861 other=unix_peer(sk);
1862 if (other)
1863 sock_hold(other);
1864 unix_state_unlock(sk);
1865 sk->sk_state_change(sk);
1866
1867 if (other &&
1868 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1869
1870 int peer_mode = 0;
1871
1872 if (mode&RCV_SHUTDOWN)
1873 peer_mode |= SEND_SHUTDOWN;
1874 if (mode&SEND_SHUTDOWN)
1875 peer_mode |= RCV_SHUTDOWN;
1876 unix_state_lock(other);
1877 other->sk_shutdown |= peer_mode;
1878 unix_state_unlock(other);
1879 other->sk_state_change(other);
1880 read_lock(&other->sk_callback_lock);
1881 if (peer_mode == SHUTDOWN_MASK)
1882 sk_wake_async(other,1,POLL_HUP);
1883 else if (peer_mode & RCV_SHUTDOWN)
1884 sk_wake_async(other,1,POLL_IN);
1885 read_unlock(&other->sk_callback_lock);
1886 }
1887 if (other)
1888 sock_put(other);
1889 }
1890 return 0;
1891 }
1892
1893 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1894 {
1895 struct sock *sk = sock->sk;
1896 long amount=0;
1897 int err;
1898
1899 switch(cmd)
1900 {
1901 case SIOCOUTQ:
1902 amount = atomic_read(&sk->sk_wmem_alloc);
1903 err = put_user(amount, (int __user *)arg);
1904 break;
1905 case SIOCINQ:
1906 {
1907 struct sk_buff *skb;
1908
1909 if (sk->sk_state == TCP_LISTEN) {
1910 err = -EINVAL;
1911 break;
1912 }
1913
1914 spin_lock(&sk->sk_receive_queue.lock);
1915 if (sk->sk_type == SOCK_STREAM ||
1916 sk->sk_type == SOCK_SEQPACKET) {
1917 skb_queue_walk(&sk->sk_receive_queue, skb)
1918 amount += skb->len;
1919 } else {
1920 skb = skb_peek(&sk->sk_receive_queue);
1921 if (skb)
1922 amount=skb->len;
1923 }
1924 spin_unlock(&sk->sk_receive_queue.lock);
1925 err = put_user(amount, (int __user *)arg);
1926 break;
1927 }
1928
1929 default:
1930 err = -ENOIOCTLCMD;
1931 break;
1932 }
1933 return err;
1934 }
1935
1936 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1937 {
1938 struct sock *sk = sock->sk;
1939 unsigned int mask;
1940
1941 poll_wait(file, sk->sk_sleep, wait);
1942 mask = 0;
1943
1944 /* exceptional events? */
1945 if (sk->sk_err)
1946 mask |= POLLERR;
1947 if (sk->sk_shutdown == SHUTDOWN_MASK)
1948 mask |= POLLHUP;
1949 if (sk->sk_shutdown & RCV_SHUTDOWN)
1950 mask |= POLLRDHUP;
1951
1952 /* readable? */
1953 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1954 (sk->sk_shutdown & RCV_SHUTDOWN))
1955 mask |= POLLIN | POLLRDNORM;
1956
1957 /* Connection-based need to check for termination and startup */
1958 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
1959 mask |= POLLHUP;
1960
1961 /*
1962 * we set writable also when the other side has shut down the
1963 * connection. This prevents stuck sockets.
1964 */
1965 if (unix_writable(sk))
1966 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1967
1968 return mask;
1969 }
1970
1971
1972 #ifdef CONFIG_PROC_FS
1973 static struct sock *unix_seq_idx(int *iter, loff_t pos)
1974 {
1975 loff_t off = 0;
1976 struct sock *s;
1977
1978 for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) {
1979 if (off == pos)
1980 return s;
1981 ++off;
1982 }
1983 return NULL;
1984 }
1985
1986
1987 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
1988 {
1989 spin_lock(&unix_table_lock);
1990 return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1);
1991 }
1992
1993 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1994 {
1995 ++*pos;
1996
1997 if (v == (void *)1)
1998 return first_unix_socket(seq->private);
1999 return next_unix_socket(seq->private, v);
2000 }
2001
2002 static void unix_seq_stop(struct seq_file *seq, void *v)
2003 {
2004 spin_unlock(&unix_table_lock);
2005 }
2006
2007 static int unix_seq_show(struct seq_file *seq, void *v)
2008 {
2009
2010 if (v == (void *)1)
2011 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2012 "Inode Path\n");
2013 else {
2014 struct sock *s = v;
2015 struct unix_sock *u = unix_sk(s);
2016 unix_state_lock(s);
2017
2018 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2019 s,
2020 atomic_read(&s->sk_refcnt),
2021 0,
2022 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2023 s->sk_type,
2024 s->sk_socket ?
2025 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2026 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2027 sock_i_ino(s));
2028
2029 if (u->addr) {
2030 int i, len;
2031 seq_putc(seq, ' ');
2032
2033 i = 0;
2034 len = u->addr->len - sizeof(short);
2035 if (!UNIX_ABSTRACT(s))
2036 len--;
2037 else {
2038 seq_putc(seq, '@');
2039 i++;
2040 }
2041 for ( ; i < len; i++)
2042 seq_putc(seq, u->addr->name->sun_path[i]);
2043 }
2044 unix_state_unlock(s);
2045 seq_putc(seq, '\n');
2046 }
2047
2048 return 0;
2049 }
2050
2051 static struct seq_operations unix_seq_ops = {
2052 .start = unix_seq_start,
2053 .next = unix_seq_next,
2054 .stop = unix_seq_stop,
2055 .show = unix_seq_show,
2056 };
2057
2058
2059 static int unix_seq_open(struct inode *inode, struct file *file)
2060 {
2061 struct seq_file *seq;
2062 int rc = -ENOMEM;
2063 int *iter = kmalloc(sizeof(int), GFP_KERNEL);
2064
2065 if (!iter)
2066 goto out;
2067
2068 rc = seq_open(file, &unix_seq_ops);
2069 if (rc)
2070 goto out_kfree;
2071
2072 seq = file->private_data;
2073 seq->private = iter;
2074 *iter = 0;
2075 out:
2076 return rc;
2077 out_kfree:
2078 kfree(iter);
2079 goto out;
2080 }
2081
2082 static const struct file_operations unix_seq_fops = {
2083 .owner = THIS_MODULE,
2084 .open = unix_seq_open,
2085 .read = seq_read,
2086 .llseek = seq_lseek,
2087 .release = seq_release_private,
2088 };
2089
2090 #endif
2091
2092 static struct net_proto_family unix_family_ops = {
2093 .family = PF_UNIX,
2094 .create = unix_create,
2095 .owner = THIS_MODULE,
2096 };
2097
2098 static int __init af_unix_init(void)
2099 {
2100 int rc = -1;
2101 struct sk_buff *dummy_skb;
2102
2103 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2104
2105 rc = proto_register(&unix_proto, 1);
2106 if (rc != 0) {
2107 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2108 __FUNCTION__);
2109 goto out;
2110 }
2111
2112 sock_register(&unix_family_ops);
2113 #ifdef CONFIG_PROC_FS
2114 proc_net_fops_create("unix", 0, &unix_seq_fops);
2115 #endif
2116 unix_sysctl_register();
2117 out:
2118 return rc;
2119 }
2120
2121 static void __exit af_unix_exit(void)
2122 {
2123 sock_unregister(PF_UNIX);
2124 unix_sysctl_unregister();
2125 proc_net_remove("unix");
2126 proto_unregister(&unix_proto);
2127 }
2128
2129 module_init(af_unix_init);
2130 module_exit(af_unix_exit);
2131
2132 MODULE_LICENSE("GPL");
2133 MODULE_ALIAS_NETPROTO(PF_UNIX);
Linux 2.6 libata-dev (mirror)