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net_sched: implement a root container qdisc sch_mqprio
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / unix / af_unix.c
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1/*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
4 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Fixes:
12 * Linus Torvalds : Assorted bug cures.
13 * Niibe Yutaka : async I/O support.
14 * Carsten Paeth : PF_UNIX check, address fixes.
15 * Alan Cox : Limit size of allocated blocks.
16 * Alan Cox : Fixed the stupid socketpair bug.
17 * Alan Cox : BSD compatibility fine tuning.
18 * Alan Cox : Fixed a bug in connect when interrupted.
19 * Alan Cox : Sorted out a proper draft version of
20 * file descriptor passing hacked up from
21 * Mike Shaver's work.
22 * Marty Leisner : Fixes to fd passing
23 * Nick Nevin : recvmsg bugfix.
24 * Alan Cox : Started proper garbage collector
25 * Heiko EiBfeldt : Missing verify_area check
26 * Alan Cox : Started POSIXisms
27 * Andreas Schwab : Replace inode by dentry for proper
28 * reference counting
29 * Kirk Petersen : Made this a module
30 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
31 * Lots of bug fixes.
32 * Alexey Kuznetosv : Repaired (I hope) bugs introduces
33 * by above two patches.
34 * Andrea Arcangeli : If possible we block in connect(2)
35 * if the max backlog of the listen socket
36 * is been reached. This won't break
37 * old apps and it will avoid huge amount
38 * of socks hashed (this for unix_gc()
39 * performances reasons).
40 * Security fix that limits the max
41 * number of socks to 2*max_files and
42 * the number of skb queueable in the
43 * dgram receiver.
44 * Artur Skawina : Hash function optimizations
45 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
46 * Malcolm Beattie : Set peercred for socketpair
47 * Michal Ostrowski : Module initialization cleanup.
48 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
49 * the core infrastructure is doing that
50 * for all net proto families now (2.5.69+)
51 *
52 *
53 * Known differences from reference BSD that was tested:
54 *
55 * [TO FIX]
56 * ECONNREFUSED is not returned from one end of a connected() socket to the
57 * other the moment one end closes.
58 * fstat() doesn't return st_dev=0, and give the blksize as high water mark
59 * and a fake inode identifier (nor the BSD first socket fstat twice bug).
60 * [NOT TO FIX]
61 * accept() returns a path name even if the connecting socket has closed
62 * in the meantime (BSD loses the path and gives up).
63 * accept() returns 0 length path for an unbound connector. BSD returns 16
64 * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
65 * socketpair(...SOCK_RAW..) doesn't panic the kernel.
66 * BSD af_unix apparently has connect forgetting to block properly.
67 * (need to check this with the POSIX spec in detail)
68 *
69 * Differences from 2.0.0-11-... (ANK)
70 * Bug fixes and improvements.
71 * - client shutdown killed server socket.
72 * - removed all useless cli/sti pairs.
73 *
74 * Semantic changes/extensions.
75 * - generic control message passing.
76 * - SCM_CREDENTIALS control message.
77 * - "Abstract" (not FS based) socket bindings.
78 * Abstract names are sequences of bytes (not zero terminated)
79 * started by 0, so that this name space does not intersect
80 * with BSD names.
81 */
82
83#include <linux/module.h>
84#include <linux/kernel.h>
85#include <linux/signal.h>
86#include <linux/sched.h>
87#include <linux/errno.h>
88#include <linux/string.h>
89#include <linux/stat.h>
90#include <linux/dcache.h>
91#include <linux/namei.h>
92#include <linux/socket.h>
93#include <linux/un.h>
94#include <linux/fcntl.h>
95#include <linux/termios.h>
96#include <linux/sockios.h>
97#include <linux/net.h>
98#include <linux/in.h>
99#include <linux/fs.h>
100#include <linux/slab.h>
101#include <asm/uaccess.h>
102#include <linux/skbuff.h>
103#include <linux/netdevice.h>
104#include <net/net_namespace.h>
105#include <net/sock.h>
106#include <net/tcp_states.h>
107#include <net/af_unix.h>
108#include <linux/proc_fs.h>
109#include <linux/seq_file.h>
110#include <net/scm.h>
111#include <linux/init.h>
112#include <linux/poll.h>
113#include <linux/rtnetlink.h>
114#include <linux/mount.h>
115#include <net/checksum.h>
116#include <linux/security.h>
117
118static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
119static DEFINE_SPINLOCK(unix_table_lock);
120static atomic_long_t unix_nr_socks;
121
122#define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
123
124#define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
125
126#ifdef CONFIG_SECURITY_NETWORK
127static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
128{
129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
130}
131
132static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
133{
134 scm->secid = *UNIXSID(skb);
135}
136#else
137static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
138{ }
139
140static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
141{ }
142#endif /* CONFIG_SECURITY_NETWORK */
143
144/*
145 * SMP locking strategy:
146 * hash table is protected with spinlock unix_table_lock
147 * each socket state is protected by separate spin lock.
148 */
149
150static inline unsigned unix_hash_fold(__wsum n)
151{
152 unsigned hash = (__force unsigned)n;
153 hash ^= hash>>16;
154 hash ^= hash>>8;
155 return hash&(UNIX_HASH_SIZE-1);
156}
157
158#define unix_peer(sk) (unix_sk(sk)->peer)
159
160static inline int unix_our_peer(struct sock *sk, struct sock *osk)
161{
162 return unix_peer(osk) == sk;
163}
164
165static inline int unix_may_send(struct sock *sk, struct sock *osk)
166{
167 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
168}
169
170static inline int unix_recvq_full(struct sock const *sk)
171{
172 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
173}
174
175static struct sock *unix_peer_get(struct sock *s)
176{
177 struct sock *peer;
178
179 unix_state_lock(s);
180 peer = unix_peer(s);
181 if (peer)
182 sock_hold(peer);
183 unix_state_unlock(s);
184 return peer;
185}
186
187static inline void unix_release_addr(struct unix_address *addr)
188{
189 if (atomic_dec_and_test(&addr->refcnt))
190 kfree(addr);
191}
192
193/*
194 * Check unix socket name:
195 * - should be not zero length.
196 * - if started by not zero, should be NULL terminated (FS object)
197 * - if started by zero, it is abstract name.
198 */
199
200static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned *hashp)
201{
202 if (len <= sizeof(short) || len > sizeof(*sunaddr))
203 return -EINVAL;
204 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
205 return -EINVAL;
206 if (sunaddr->sun_path[0]) {
207 /*
208 * This may look like an off by one error but it is a bit more
209 * subtle. 108 is the longest valid AF_UNIX path for a binding.
210 * sun_path[108] doesnt as such exist. However in kernel space
211 * we are guaranteed that it is a valid memory location in our
212 * kernel address buffer.
213 */
214 ((char *)sunaddr)[len] = 0;
215 len = strlen(sunaddr->sun_path)+1+sizeof(short);
216 return len;
217 }
218
219 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
220 return len;
221}
222
223static void __unix_remove_socket(struct sock *sk)
224{
225 sk_del_node_init(sk);
226}
227
228static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
229{
230 WARN_ON(!sk_unhashed(sk));
231 sk_add_node(sk, list);
232}
233
234static inline void unix_remove_socket(struct sock *sk)
235{
236 spin_lock(&unix_table_lock);
237 __unix_remove_socket(sk);
238 spin_unlock(&unix_table_lock);
239}
240
241static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
242{
243 spin_lock(&unix_table_lock);
244 __unix_insert_socket(list, sk);
245 spin_unlock(&unix_table_lock);
246}
247
248static struct sock *__unix_find_socket_byname(struct net *net,
249 struct sockaddr_un *sunname,
250 int len, int type, unsigned hash)
251{
252 struct sock *s;
253 struct hlist_node *node;
254
255 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
256 struct unix_sock *u = unix_sk(s);
257
258 if (!net_eq(sock_net(s), net))
259 continue;
260
261 if (u->addr->len == len &&
262 !memcmp(u->addr->name, sunname, len))
263 goto found;
264 }
265 s = NULL;
266found:
267 return s;
268}
269
270static inline struct sock *unix_find_socket_byname(struct net *net,
271 struct sockaddr_un *sunname,
272 int len, int type,
273 unsigned hash)
274{
275 struct sock *s;
276
277 spin_lock(&unix_table_lock);
278 s = __unix_find_socket_byname(net, sunname, len, type, hash);
279 if (s)
280 sock_hold(s);
281 spin_unlock(&unix_table_lock);
282 return s;
283}
284
285static struct sock *unix_find_socket_byinode(struct inode *i)
286{
287 struct sock *s;
288 struct hlist_node *node;
289
290 spin_lock(&unix_table_lock);
291 sk_for_each(s, node,
292 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
293 struct dentry *dentry = unix_sk(s)->dentry;
294
295 if (dentry && dentry->d_inode == i) {
296 sock_hold(s);
297 goto found;
298 }
299 }
300 s = NULL;
301found:
302 spin_unlock(&unix_table_lock);
303 return s;
304}
305
306static inline int unix_writable(struct sock *sk)
307{
308 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
309}
310
311static void unix_write_space(struct sock *sk)
312{
313 struct socket_wq *wq;
314
315 rcu_read_lock();
316 if (unix_writable(sk)) {
317 wq = rcu_dereference(sk->sk_wq);
318 if (wq_has_sleeper(wq))
319 wake_up_interruptible_sync_poll(&wq->wait,
320 POLLOUT | POLLWRNORM | POLLWRBAND);
321 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
322 }
323 rcu_read_unlock();
324}
325
326/* When dgram socket disconnects (or changes its peer), we clear its receive
327 * queue of packets arrived from previous peer. First, it allows to do
328 * flow control based only on wmem_alloc; second, sk connected to peer
329 * may receive messages only from that peer. */
330static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
331{
332 if (!skb_queue_empty(&sk->sk_receive_queue)) {
333 skb_queue_purge(&sk->sk_receive_queue);
334 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
335
336 /* If one link of bidirectional dgram pipe is disconnected,
337 * we signal error. Messages are lost. Do not make this,
338 * when peer was not connected to us.
339 */
340 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
341 other->sk_err = ECONNRESET;
342 other->sk_error_report(other);
343 }
344 }
345}
346
347static void unix_sock_destructor(struct sock *sk)
348{
349 struct unix_sock *u = unix_sk(sk);
350
351 skb_queue_purge(&sk->sk_receive_queue);
352
353 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
354 WARN_ON(!sk_unhashed(sk));
355 WARN_ON(sk->sk_socket);
356 if (!sock_flag(sk, SOCK_DEAD)) {
357 printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk);
358 return;
359 }
360
361 if (u->addr)
362 unix_release_addr(u->addr);
363
364 atomic_long_dec(&unix_nr_socks);
365 local_bh_disable();
366 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
367 local_bh_enable();
368#ifdef UNIX_REFCNT_DEBUG
369 printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk,
370 atomic_long_read(&unix_nr_socks));
371#endif
372}
373
374static int unix_release_sock(struct sock *sk, int embrion)
375{
376 struct unix_sock *u = unix_sk(sk);
377 struct dentry *dentry;
378 struct vfsmount *mnt;
379 struct sock *skpair;
380 struct sk_buff *skb;
381 int state;
382
383 unix_remove_socket(sk);
384
385 /* Clear state */
386 unix_state_lock(sk);
387 sock_orphan(sk);
388 sk->sk_shutdown = SHUTDOWN_MASK;
389 dentry = u->dentry;
390 u->dentry = NULL;
391 mnt = u->mnt;
392 u->mnt = NULL;
393 state = sk->sk_state;
394 sk->sk_state = TCP_CLOSE;
395 unix_state_unlock(sk);
396
397 wake_up_interruptible_all(&u->peer_wait);
398
399 skpair = unix_peer(sk);
400
401 if (skpair != NULL) {
402 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
403 unix_state_lock(skpair);
404 /* No more writes */
405 skpair->sk_shutdown = SHUTDOWN_MASK;
406 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
407 skpair->sk_err = ECONNRESET;
408 unix_state_unlock(skpair);
409 skpair->sk_state_change(skpair);
410 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
411 }
412 sock_put(skpair); /* It may now die */
413 unix_peer(sk) = NULL;
414 }
415
416 /* Try to flush out this socket. Throw out buffers at least */
417
418 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
419 if (state == TCP_LISTEN)
420 unix_release_sock(skb->sk, 1);
421 /* passed fds are erased in the kfree_skb hook */
422 kfree_skb(skb);
423 }
424
425 if (dentry) {
426 dput(dentry);
427 mntput(mnt);
428 }
429
430 sock_put(sk);
431
432 /* ---- Socket is dead now and most probably destroyed ---- */
433
434 /*
435 * Fixme: BSD difference: In BSD all sockets connected to use get
436 * ECONNRESET and we die on the spot. In Linux we behave
437 * like files and pipes do and wait for the last
438 * dereference.
439 *
440 * Can't we simply set sock->err?
441 *
442 * What the above comment does talk about? --ANK(980817)
443 */
444
445 if (unix_tot_inflight)
446 unix_gc(); /* Garbage collect fds */
447
448 return 0;
449}
450
451static void init_peercred(struct sock *sk)
452{
453 put_pid(sk->sk_peer_pid);
454 if (sk->sk_peer_cred)
455 put_cred(sk->sk_peer_cred);
456 sk->sk_peer_pid = get_pid(task_tgid(current));
457 sk->sk_peer_cred = get_current_cred();
458}
459
460static void copy_peercred(struct sock *sk, struct sock *peersk)
461{
462 put_pid(sk->sk_peer_pid);
463 if (sk->sk_peer_cred)
464 put_cred(sk->sk_peer_cred);
465 sk->sk_peer_pid = get_pid(peersk->sk_peer_pid);
466 sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
467}
468
469static int unix_listen(struct socket *sock, int backlog)
470{
471 int err;
472 struct sock *sk = sock->sk;
473 struct unix_sock *u = unix_sk(sk);
474 struct pid *old_pid = NULL;
475 const struct cred *old_cred = NULL;
476
477 err = -EOPNOTSUPP;
478 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
479 goto out; /* Only stream/seqpacket sockets accept */
480 err = -EINVAL;
481 if (!u->addr)
482 goto out; /* No listens on an unbound socket */
483 unix_state_lock(sk);
484 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
485 goto out_unlock;
486 if (backlog > sk->sk_max_ack_backlog)
487 wake_up_interruptible_all(&u->peer_wait);
488 sk->sk_max_ack_backlog = backlog;
489 sk->sk_state = TCP_LISTEN;
490 /* set credentials so connect can copy them */
491 init_peercred(sk);
492 err = 0;
493
494out_unlock:
495 unix_state_unlock(sk);
496 put_pid(old_pid);
497 if (old_cred)
498 put_cred(old_cred);
499out:
500 return err;
501}
502
503static int unix_release(struct socket *);
504static int unix_bind(struct socket *, struct sockaddr *, int);
505static int unix_stream_connect(struct socket *, struct sockaddr *,
506 int addr_len, int flags);
507static int unix_socketpair(struct socket *, struct socket *);
508static int unix_accept(struct socket *, struct socket *, int);
509static int unix_getname(struct socket *, struct sockaddr *, int *, int);
510static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
511static unsigned int unix_dgram_poll(struct file *, struct socket *,
512 poll_table *);
513static int unix_ioctl(struct socket *, unsigned int, unsigned long);
514static int unix_shutdown(struct socket *, int);
515static int unix_stream_sendmsg(struct kiocb *, struct socket *,
516 struct msghdr *, size_t);
517static int unix_stream_recvmsg(struct kiocb *, struct socket *,
518 struct msghdr *, size_t, int);
519static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
520 struct msghdr *, size_t);
521static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
522 struct msghdr *, size_t, int);
523static int unix_dgram_connect(struct socket *, struct sockaddr *,
524 int, int);
525static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
526 struct msghdr *, size_t);
527
528static const struct proto_ops unix_stream_ops = {
529 .family = PF_UNIX,
530 .owner = THIS_MODULE,
531 .release = unix_release,
532 .bind = unix_bind,
533 .connect = unix_stream_connect,
534 .socketpair = unix_socketpair,
535 .accept = unix_accept,
536 .getname = unix_getname,
537 .poll = unix_poll,
538 .ioctl = unix_ioctl,
539 .listen = unix_listen,
540 .shutdown = unix_shutdown,
541 .setsockopt = sock_no_setsockopt,
542 .getsockopt = sock_no_getsockopt,
543 .sendmsg = unix_stream_sendmsg,
544 .recvmsg = unix_stream_recvmsg,
545 .mmap = sock_no_mmap,
546 .sendpage = sock_no_sendpage,
547};
548
549static const struct proto_ops unix_dgram_ops = {
550 .family = PF_UNIX,
551 .owner = THIS_MODULE,
552 .release = unix_release,
553 .bind = unix_bind,
554 .connect = unix_dgram_connect,
555 .socketpair = unix_socketpair,
556 .accept = sock_no_accept,
557 .getname = unix_getname,
558 .poll = unix_dgram_poll,
559 .ioctl = unix_ioctl,
560 .listen = sock_no_listen,
561 .shutdown = unix_shutdown,
562 .setsockopt = sock_no_setsockopt,
563 .getsockopt = sock_no_getsockopt,
564 .sendmsg = unix_dgram_sendmsg,
565 .recvmsg = unix_dgram_recvmsg,
566 .mmap = sock_no_mmap,
567 .sendpage = sock_no_sendpage,
568};
569
570static const struct proto_ops unix_seqpacket_ops = {
571 .family = PF_UNIX,
572 .owner = THIS_MODULE,
573 .release = unix_release,
574 .bind = unix_bind,
575 .connect = unix_stream_connect,
576 .socketpair = unix_socketpair,
577 .accept = unix_accept,
578 .getname = unix_getname,
579 .poll = unix_dgram_poll,
580 .ioctl = unix_ioctl,
581 .listen = unix_listen,
582 .shutdown = unix_shutdown,
583 .setsockopt = sock_no_setsockopt,
584 .getsockopt = sock_no_getsockopt,
585 .sendmsg = unix_seqpacket_sendmsg,
586 .recvmsg = unix_dgram_recvmsg,
587 .mmap = sock_no_mmap,
588 .sendpage = sock_no_sendpage,
589};
590
591static struct proto unix_proto = {
592 .name = "UNIX",
593 .owner = THIS_MODULE,
594 .obj_size = sizeof(struct unix_sock),
595};
596
597/*
598 * AF_UNIX sockets do not interact with hardware, hence they
599 * dont trigger interrupts - so it's safe for them to have
600 * bh-unsafe locking for their sk_receive_queue.lock. Split off
601 * this special lock-class by reinitializing the spinlock key:
602 */
603static struct lock_class_key af_unix_sk_receive_queue_lock_key;
604
605static struct sock *unix_create1(struct net *net, struct socket *sock)
606{
607 struct sock *sk = NULL;
608 struct unix_sock *u;
609
610 atomic_long_inc(&unix_nr_socks);
611 if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
612 goto out;
613
614 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
615 if (!sk)
616 goto out;
617
618 sock_init_data(sock, sk);
619 lockdep_set_class(&sk->sk_receive_queue.lock,
620 &af_unix_sk_receive_queue_lock_key);
621
622 sk->sk_write_space = unix_write_space;
623 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
624 sk->sk_destruct = unix_sock_destructor;
625 u = unix_sk(sk);
626 u->dentry = NULL;
627 u->mnt = NULL;
628 spin_lock_init(&u->lock);
629 atomic_long_set(&u->inflight, 0);
630 INIT_LIST_HEAD(&u->link);
631 mutex_init(&u->readlock); /* single task reading lock */
632 init_waitqueue_head(&u->peer_wait);
633 unix_insert_socket(unix_sockets_unbound, sk);
634out:
635 if (sk == NULL)
636 atomic_long_dec(&unix_nr_socks);
637 else {
638 local_bh_disable();
639 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
640 local_bh_enable();
641 }
642 return sk;
643}
644
645static int unix_create(struct net *net, struct socket *sock, int protocol,
646 int kern)
647{
648 if (protocol && protocol != PF_UNIX)
649 return -EPROTONOSUPPORT;
650
651 sock->state = SS_UNCONNECTED;
652
653 switch (sock->type) {
654 case SOCK_STREAM:
655 sock->ops = &unix_stream_ops;
656 break;
657 /*
658 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
659 * nothing uses it.
660 */
661 case SOCK_RAW:
662 sock->type = SOCK_DGRAM;
663 case SOCK_DGRAM:
664 sock->ops = &unix_dgram_ops;
665 break;
666 case SOCK_SEQPACKET:
667 sock->ops = &unix_seqpacket_ops;
668 break;
669 default:
670 return -ESOCKTNOSUPPORT;
671 }
672
673 return unix_create1(net, sock) ? 0 : -ENOMEM;
674}
675
676static int unix_release(struct socket *sock)
677{
678 struct sock *sk = sock->sk;
679
680 if (!sk)
681 return 0;
682
683 sock->sk = NULL;
684
685 return unix_release_sock(sk, 0);
686}
687
688static int unix_autobind(struct socket *sock)
689{
690 struct sock *sk = sock->sk;
691 struct net *net = sock_net(sk);
692 struct unix_sock *u = unix_sk(sk);
693 static u32 ordernum = 1;
694 struct unix_address *addr;
695 int err;
696 unsigned int retries = 0;
697
698 mutex_lock(&u->readlock);
699
700 err = 0;
701 if (u->addr)
702 goto out;
703
704 err = -ENOMEM;
705 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
706 if (!addr)
707 goto out;
708
709 addr->name->sun_family = AF_UNIX;
710 atomic_set(&addr->refcnt, 1);
711
712retry:
713 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
714 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
715
716 spin_lock(&unix_table_lock);
717 ordernum = (ordernum+1)&0xFFFFF;
718
719 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
720 addr->hash)) {
721 spin_unlock(&unix_table_lock);
722 /*
723 * __unix_find_socket_byname() may take long time if many names
724 * are already in use.
725 */
726 cond_resched();
727 /* Give up if all names seems to be in use. */
728 if (retries++ == 0xFFFFF) {
729 err = -ENOSPC;
730 kfree(addr);
731 goto out;
732 }
733 goto retry;
734 }
735 addr->hash ^= sk->sk_type;
736
737 __unix_remove_socket(sk);
738 u->addr = addr;
739 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
740 spin_unlock(&unix_table_lock);
741 err = 0;
742
743out: mutex_unlock(&u->readlock);
744 return err;
745}
746
747static struct sock *unix_find_other(struct net *net,
748 struct sockaddr_un *sunname, int len,
749 int type, unsigned hash, int *error)
750{
751 struct sock *u;
752 struct path path;
753 int err = 0;
754
755 if (sunname->sun_path[0]) {
756 struct inode *inode;
757 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
758 if (err)
759 goto fail;
760 inode = path.dentry->d_inode;
761 err = inode_permission(inode, MAY_WRITE);
762 if (err)
763 goto put_fail;
764
765 err = -ECONNREFUSED;
766 if (!S_ISSOCK(inode->i_mode))
767 goto put_fail;
768 u = unix_find_socket_byinode(inode);
769 if (!u)
770 goto put_fail;
771
772 if (u->sk_type == type)
773 touch_atime(path.mnt, path.dentry);
774
775 path_put(&path);
776
777 err = -EPROTOTYPE;
778 if (u->sk_type != type) {
779 sock_put(u);
780 goto fail;
781 }
782 } else {
783 err = -ECONNREFUSED;
784 u = unix_find_socket_byname(net, sunname, len, type, hash);
785 if (u) {
786 struct dentry *dentry;
787 dentry = unix_sk(u)->dentry;
788 if (dentry)
789 touch_atime(unix_sk(u)->mnt, dentry);
790 } else
791 goto fail;
792 }
793 return u;
794
795put_fail:
796 path_put(&path);
797fail:
798 *error = err;
799 return NULL;
800}
801
802
803static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
804{
805 struct sock *sk = sock->sk;
806 struct net *net = sock_net(sk);
807 struct unix_sock *u = unix_sk(sk);
808 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
809 struct dentry *dentry = NULL;
810 struct nameidata nd;
811 int err;
812 unsigned hash;
813 struct unix_address *addr;
814 struct hlist_head *list;
815
816 err = -EINVAL;
817 if (sunaddr->sun_family != AF_UNIX)
818 goto out;
819
820 if (addr_len == sizeof(short)) {
821 err = unix_autobind(sock);
822 goto out;
823 }
824
825 err = unix_mkname(sunaddr, addr_len, &hash);
826 if (err < 0)
827 goto out;
828 addr_len = err;
829
830 mutex_lock(&u->readlock);
831
832 err = -EINVAL;
833 if (u->addr)
834 goto out_up;
835
836 err = -ENOMEM;
837 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
838 if (!addr)
839 goto out_up;
840
841 memcpy(addr->name, sunaddr, addr_len);
842 addr->len = addr_len;
843 addr->hash = hash ^ sk->sk_type;
844 atomic_set(&addr->refcnt, 1);
845
846 if (sunaddr->sun_path[0]) {
847 unsigned int mode;
848 err = 0;
849 /*
850 * Get the parent directory, calculate the hash for last
851 * component.
852 */
853 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
854 if (err)
855 goto out_mknod_parent;
856
857 dentry = lookup_create(&nd, 0);
858 err = PTR_ERR(dentry);
859 if (IS_ERR(dentry))
860 goto out_mknod_unlock;
861
862 /*
863 * All right, let's create it.
864 */
865 mode = S_IFSOCK |
866 (SOCK_INODE(sock)->i_mode & ~current_umask());
867 err = mnt_want_write(nd.path.mnt);
868 if (err)
869 goto out_mknod_dput;
870 err = security_path_mknod(&nd.path, dentry, mode, 0);
871 if (err)
872 goto out_mknod_drop_write;
873 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
874out_mknod_drop_write:
875 mnt_drop_write(nd.path.mnt);
876 if (err)
877 goto out_mknod_dput;
878 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
879 dput(nd.path.dentry);
880 nd.path.dentry = dentry;
881
882 addr->hash = UNIX_HASH_SIZE;
883 }
884
885 spin_lock(&unix_table_lock);
886
887 if (!sunaddr->sun_path[0]) {
888 err = -EADDRINUSE;
889 if (__unix_find_socket_byname(net, sunaddr, addr_len,
890 sk->sk_type, hash)) {
891 unix_release_addr(addr);
892 goto out_unlock;
893 }
894
895 list = &unix_socket_table[addr->hash];
896 } else {
897 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
898 u->dentry = nd.path.dentry;
899 u->mnt = nd.path.mnt;
900 }
901
902 err = 0;
903 __unix_remove_socket(sk);
904 u->addr = addr;
905 __unix_insert_socket(list, sk);
906
907out_unlock:
908 spin_unlock(&unix_table_lock);
909out_up:
910 mutex_unlock(&u->readlock);
911out:
912 return err;
913
914out_mknod_dput:
915 dput(dentry);
916out_mknod_unlock:
917 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
918 path_put(&nd.path);
919out_mknod_parent:
920 if (err == -EEXIST)
921 err = -EADDRINUSE;
922 unix_release_addr(addr);
923 goto out_up;
924}
925
926static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
927{
928 if (unlikely(sk1 == sk2) || !sk2) {
929 unix_state_lock(sk1);
930 return;
931 }
932 if (sk1 < sk2) {
933 unix_state_lock(sk1);
934 unix_state_lock_nested(sk2);
935 } else {
936 unix_state_lock(sk2);
937 unix_state_lock_nested(sk1);
938 }
939}
940
941static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
942{
943 if (unlikely(sk1 == sk2) || !sk2) {
944 unix_state_unlock(sk1);
945 return;
946 }
947 unix_state_unlock(sk1);
948 unix_state_unlock(sk2);
949}
950
951static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
952 int alen, int flags)
953{
954 struct sock *sk = sock->sk;
955 struct net *net = sock_net(sk);
956 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
957 struct sock *other;
958 unsigned hash;
959 int err;
960
961 if (addr->sa_family != AF_UNSPEC) {
962 err = unix_mkname(sunaddr, alen, &hash);
963 if (err < 0)
964 goto out;
965 alen = err;
966
967 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
968 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
969 goto out;
970
971restart:
972 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
973 if (!other)
974 goto out;
975
976 unix_state_double_lock(sk, other);
977
978 /* Apparently VFS overslept socket death. Retry. */
979 if (sock_flag(other, SOCK_DEAD)) {
980 unix_state_double_unlock(sk, other);
981 sock_put(other);
982 goto restart;
983 }
984
985 err = -EPERM;
986 if (!unix_may_send(sk, other))
987 goto out_unlock;
988
989 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
990 if (err)
991 goto out_unlock;
992
993 } else {
994 /*
995 * 1003.1g breaking connected state with AF_UNSPEC
996 */
997 other = NULL;
998 unix_state_double_lock(sk, other);
999 }
1000
1001 /*
1002 * If it was connected, reconnect.
1003 */
1004 if (unix_peer(sk)) {
1005 struct sock *old_peer = unix_peer(sk);
1006 unix_peer(sk) = other;
1007 unix_state_double_unlock(sk, other);
1008
1009 if (other != old_peer)
1010 unix_dgram_disconnected(sk, old_peer);
1011 sock_put(old_peer);
1012 } else {
1013 unix_peer(sk) = other;
1014 unix_state_double_unlock(sk, other);
1015 }
1016 return 0;
1017
1018out_unlock:
1019 unix_state_double_unlock(sk, other);
1020 sock_put(other);
1021out:
1022 return err;
1023}
1024
1025static long unix_wait_for_peer(struct sock *other, long timeo)
1026{
1027 struct unix_sock *u = unix_sk(other);
1028 int sched;
1029 DEFINE_WAIT(wait);
1030
1031 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1032
1033 sched = !sock_flag(other, SOCK_DEAD) &&
1034 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1035 unix_recvq_full(other);
1036
1037 unix_state_unlock(other);
1038
1039 if (sched)
1040 timeo = schedule_timeout(timeo);
1041
1042 finish_wait(&u->peer_wait, &wait);
1043 return timeo;
1044}
1045
1046static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1047 int addr_len, int flags)
1048{
1049 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
1050 struct sock *sk = sock->sk;
1051 struct net *net = sock_net(sk);
1052 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1053 struct sock *newsk = NULL;
1054 struct sock *other = NULL;
1055 struct sk_buff *skb = NULL;
1056 unsigned hash;
1057 int st;
1058 int err;
1059 long timeo;
1060
1061 err = unix_mkname(sunaddr, addr_len, &hash);
1062 if (err < 0)
1063 goto out;
1064 addr_len = err;
1065
1066 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1067 (err = unix_autobind(sock)) != 0)
1068 goto out;
1069
1070 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1071
1072 /* First of all allocate resources.
1073 If we will make it after state is locked,
1074 we will have to recheck all again in any case.
1075 */
1076
1077 err = -ENOMEM;
1078
1079 /* create new sock for complete connection */
1080 newsk = unix_create1(sock_net(sk), NULL);
1081 if (newsk == NULL)
1082 goto out;
1083
1084 /* Allocate skb for sending to listening sock */
1085 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1086 if (skb == NULL)
1087 goto out;
1088
1089restart:
1090 /* Find listening sock. */
1091 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1092 if (!other)
1093 goto out;
1094
1095 /* Latch state of peer */
1096 unix_state_lock(other);
1097
1098 /* Apparently VFS overslept socket death. Retry. */
1099 if (sock_flag(other, SOCK_DEAD)) {
1100 unix_state_unlock(other);
1101 sock_put(other);
1102 goto restart;
1103 }
1104
1105 err = -ECONNREFUSED;
1106 if (other->sk_state != TCP_LISTEN)
1107 goto out_unlock;
1108 if (other->sk_shutdown & RCV_SHUTDOWN)
1109 goto out_unlock;
1110
1111 if (unix_recvq_full(other)) {
1112 err = -EAGAIN;
1113 if (!timeo)
1114 goto out_unlock;
1115
1116 timeo = unix_wait_for_peer(other, timeo);
1117
1118 err = sock_intr_errno(timeo);
1119 if (signal_pending(current))
1120 goto out;
1121 sock_put(other);
1122 goto restart;
1123 }
1124
1125 /* Latch our state.
1126
1127 It is tricky place. We need to grab write lock and cannot
1128 drop lock on peer. It is dangerous because deadlock is
1129 possible. Connect to self case and simultaneous
1130 attempt to connect are eliminated by checking socket
1131 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1132 check this before attempt to grab lock.
1133
1134 Well, and we have to recheck the state after socket locked.
1135 */
1136 st = sk->sk_state;
1137
1138 switch (st) {
1139 case TCP_CLOSE:
1140 /* This is ok... continue with connect */
1141 break;
1142 case TCP_ESTABLISHED:
1143 /* Socket is already connected */
1144 err = -EISCONN;
1145 goto out_unlock;
1146 default:
1147 err = -EINVAL;
1148 goto out_unlock;
1149 }
1150
1151 unix_state_lock_nested(sk);
1152
1153 if (sk->sk_state != st) {
1154 unix_state_unlock(sk);
1155 unix_state_unlock(other);
1156 sock_put(other);
1157 goto restart;
1158 }
1159
1160 err = security_unix_stream_connect(sk, other, newsk);
1161 if (err) {
1162 unix_state_unlock(sk);
1163 goto out_unlock;
1164 }
1165
1166 /* The way is open! Fastly set all the necessary fields... */
1167
1168 sock_hold(sk);
1169 unix_peer(newsk) = sk;
1170 newsk->sk_state = TCP_ESTABLISHED;
1171 newsk->sk_type = sk->sk_type;
1172 init_peercred(newsk);
1173 newu = unix_sk(newsk);
1174 newsk->sk_wq = &newu->peer_wq;
1175 otheru = unix_sk(other);
1176
1177 /* copy address information from listening to new sock*/
1178 if (otheru->addr) {
1179 atomic_inc(&otheru->addr->refcnt);
1180 newu->addr = otheru->addr;
1181 }
1182 if (otheru->dentry) {
1183 newu->dentry = dget(otheru->dentry);
1184 newu->mnt = mntget(otheru->mnt);
1185 }
1186
1187 /* Set credentials */
1188 copy_peercred(sk, other);
1189
1190 sock->state = SS_CONNECTED;
1191 sk->sk_state = TCP_ESTABLISHED;
1192 sock_hold(newsk);
1193
1194 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1195 unix_peer(sk) = newsk;
1196
1197 unix_state_unlock(sk);
1198
1199 /* take ten and and send info to listening sock */
1200 spin_lock(&other->sk_receive_queue.lock);
1201 __skb_queue_tail(&other->sk_receive_queue, skb);
1202 spin_unlock(&other->sk_receive_queue.lock);
1203 unix_state_unlock(other);
1204 other->sk_data_ready(other, 0);
1205 sock_put(other);
1206 return 0;
1207
1208out_unlock:
1209 if (other)
1210 unix_state_unlock(other);
1211
1212out:
1213 kfree_skb(skb);
1214 if (newsk)
1215 unix_release_sock(newsk, 0);
1216 if (other)
1217 sock_put(other);
1218 return err;
1219}
1220
1221static int unix_socketpair(struct socket *socka, struct socket *sockb)
1222{
1223 struct sock *ska = socka->sk, *skb = sockb->sk;
1224
1225 /* Join our sockets back to back */
1226 sock_hold(ska);
1227 sock_hold(skb);
1228 unix_peer(ska) = skb;
1229 unix_peer(skb) = ska;
1230 init_peercred(ska);
1231 init_peercred(skb);
1232
1233 if (ska->sk_type != SOCK_DGRAM) {
1234 ska->sk_state = TCP_ESTABLISHED;
1235 skb->sk_state = TCP_ESTABLISHED;
1236 socka->state = SS_CONNECTED;
1237 sockb->state = SS_CONNECTED;
1238 }
1239 return 0;
1240}
1241
1242static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1243{
1244 struct sock *sk = sock->sk;
1245 struct sock *tsk;
1246 struct sk_buff *skb;
1247 int err;
1248
1249 err = -EOPNOTSUPP;
1250 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
1251 goto out;
1252
1253 err = -EINVAL;
1254 if (sk->sk_state != TCP_LISTEN)
1255 goto out;
1256
1257 /* If socket state is TCP_LISTEN it cannot change (for now...),
1258 * so that no locks are necessary.
1259 */
1260
1261 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1262 if (!skb) {
1263 /* This means receive shutdown. */
1264 if (err == 0)
1265 err = -EINVAL;
1266 goto out;
1267 }
1268
1269 tsk = skb->sk;
1270 skb_free_datagram(sk, skb);
1271 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1272
1273 /* attach accepted sock to socket */
1274 unix_state_lock(tsk);
1275 newsock->state = SS_CONNECTED;
1276 sock_graft(tsk, newsock);
1277 unix_state_unlock(tsk);
1278 return 0;
1279
1280out:
1281 return err;
1282}
1283
1284
1285static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1286{
1287 struct sock *sk = sock->sk;
1288 struct unix_sock *u;
1289 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
1290 int err = 0;
1291
1292 if (peer) {
1293 sk = unix_peer_get(sk);
1294
1295 err = -ENOTCONN;
1296 if (!sk)
1297 goto out;
1298 err = 0;
1299 } else {
1300 sock_hold(sk);
1301 }
1302
1303 u = unix_sk(sk);
1304 unix_state_lock(sk);
1305 if (!u->addr) {
1306 sunaddr->sun_family = AF_UNIX;
1307 sunaddr->sun_path[0] = 0;
1308 *uaddr_len = sizeof(short);
1309 } else {
1310 struct unix_address *addr = u->addr;
1311
1312 *uaddr_len = addr->len;
1313 memcpy(sunaddr, addr->name, *uaddr_len);
1314 }
1315 unix_state_unlock(sk);
1316 sock_put(sk);
1317out:
1318 return err;
1319}
1320
1321static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1322{
1323 int i;
1324
1325 scm->fp = UNIXCB(skb).fp;
1326 UNIXCB(skb).fp = NULL;
1327
1328 for (i = scm->fp->count-1; i >= 0; i--)
1329 unix_notinflight(scm->fp->fp[i]);
1330}
1331
1332static void unix_destruct_scm(struct sk_buff *skb)
1333{
1334 struct scm_cookie scm;
1335 memset(&scm, 0, sizeof(scm));
1336 scm.pid = UNIXCB(skb).pid;
1337 scm.cred = UNIXCB(skb).cred;
1338 if (UNIXCB(skb).fp)
1339 unix_detach_fds(&scm, skb);
1340
1341 /* Alas, it calls VFS */
1342 /* So fscking what? fput() had been SMP-safe since the last Summer */
1343 scm_destroy(&scm);
1344 sock_wfree(skb);
1345}
1346
1347#define MAX_RECURSION_LEVEL 4
1348
1349static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1350{
1351 int i;
1352 unsigned char max_level = 0;
1353 int unix_sock_count = 0;
1354
1355 for (i = scm->fp->count - 1; i >= 0; i--) {
1356 struct sock *sk = unix_get_socket(scm->fp->fp[i]);
1357
1358 if (sk) {
1359 unix_sock_count++;
1360 max_level = max(max_level,
1361 unix_sk(sk)->recursion_level);
1362 }
1363 }
1364 if (unlikely(max_level > MAX_RECURSION_LEVEL))
1365 return -ETOOMANYREFS;
1366
1367 /*
1368 * Need to duplicate file references for the sake of garbage
1369 * collection. Otherwise a socket in the fps might become a
1370 * candidate for GC while the skb is not yet queued.
1371 */
1372 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1373 if (!UNIXCB(skb).fp)
1374 return -ENOMEM;
1375
1376 if (unix_sock_count) {
1377 for (i = scm->fp->count - 1; i >= 0; i--)
1378 unix_inflight(scm->fp->fp[i]);
1379 }
1380 return max_level;
1381}
1382
1383static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
1384{
1385 int err = 0;
1386 UNIXCB(skb).pid = get_pid(scm->pid);
1387 UNIXCB(skb).cred = get_cred(scm->cred);
1388 UNIXCB(skb).fp = NULL;
1389 if (scm->fp && send_fds)
1390 err = unix_attach_fds(scm, skb);
1391
1392 skb->destructor = unix_destruct_scm;
1393 return err;
1394}
1395
1396/*
1397 * Send AF_UNIX data.
1398 */
1399
1400static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1401 struct msghdr *msg, size_t len)
1402{
1403 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1404 struct sock *sk = sock->sk;
1405 struct net *net = sock_net(sk);
1406 struct unix_sock *u = unix_sk(sk);
1407 struct sockaddr_un *sunaddr = msg->msg_name;
1408 struct sock *other = NULL;
1409 int namelen = 0; /* fake GCC */
1410 int err;
1411 unsigned hash;
1412 struct sk_buff *skb;
1413 long timeo;
1414 struct scm_cookie tmp_scm;
1415 int max_level;
1416
1417 if (NULL == siocb->scm)
1418 siocb->scm = &tmp_scm;
1419 wait_for_unix_gc();
1420 err = scm_send(sock, msg, siocb->scm);
1421 if (err < 0)
1422 return err;
1423
1424 err = -EOPNOTSUPP;
1425 if (msg->msg_flags&MSG_OOB)
1426 goto out;
1427
1428 if (msg->msg_namelen) {
1429 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1430 if (err < 0)
1431 goto out;
1432 namelen = err;
1433 } else {
1434 sunaddr = NULL;
1435 err = -ENOTCONN;
1436 other = unix_peer_get(sk);
1437 if (!other)
1438 goto out;
1439 }
1440
1441 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1442 && (err = unix_autobind(sock)) != 0)
1443 goto out;
1444
1445 err = -EMSGSIZE;
1446 if (len > sk->sk_sndbuf - 32)
1447 goto out;
1448
1449 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1450 if (skb == NULL)
1451 goto out;
1452
1453 err = unix_scm_to_skb(siocb->scm, skb, true);
1454 if (err < 0)
1455 goto out_free;
1456 max_level = err + 1;
1457 unix_get_secdata(siocb->scm, skb);
1458
1459 skb_reset_transport_header(skb);
1460 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1461 if (err)
1462 goto out_free;
1463
1464 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1465
1466restart:
1467 if (!other) {
1468 err = -ECONNRESET;
1469 if (sunaddr == NULL)
1470 goto out_free;
1471
1472 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1473 hash, &err);
1474 if (other == NULL)
1475 goto out_free;
1476 }
1477
1478 if (sk_filter(other, skb) < 0) {
1479 /* Toss the packet but do not return any error to the sender */
1480 err = len;
1481 goto out_free;
1482 }
1483
1484 unix_state_lock(other);
1485 err = -EPERM;
1486 if (!unix_may_send(sk, other))
1487 goto out_unlock;
1488
1489 if (sock_flag(other, SOCK_DEAD)) {
1490 /*
1491 * Check with 1003.1g - what should
1492 * datagram error
1493 */
1494 unix_state_unlock(other);
1495 sock_put(other);
1496
1497 err = 0;
1498 unix_state_lock(sk);
1499 if (unix_peer(sk) == other) {
1500 unix_peer(sk) = NULL;
1501 unix_state_unlock(sk);
1502
1503 unix_dgram_disconnected(sk, other);
1504 sock_put(other);
1505 err = -ECONNREFUSED;
1506 } else {
1507 unix_state_unlock(sk);
1508 }
1509
1510 other = NULL;
1511 if (err)
1512 goto out_free;
1513 goto restart;
1514 }
1515
1516 err = -EPIPE;
1517 if (other->sk_shutdown & RCV_SHUTDOWN)
1518 goto out_unlock;
1519
1520 if (sk->sk_type != SOCK_SEQPACKET) {
1521 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1522 if (err)
1523 goto out_unlock;
1524 }
1525
1526 if (unix_peer(other) != sk && unix_recvq_full(other)) {
1527 if (!timeo) {
1528 err = -EAGAIN;
1529 goto out_unlock;
1530 }
1531
1532 timeo = unix_wait_for_peer(other, timeo);
1533
1534 err = sock_intr_errno(timeo);
1535 if (signal_pending(current))
1536 goto out_free;
1537
1538 goto restart;
1539 }
1540
1541 if (sock_flag(other, SOCK_RCVTSTAMP))
1542 __net_timestamp(skb);
1543 skb_queue_tail(&other->sk_receive_queue, skb);
1544 if (max_level > unix_sk(other)->recursion_level)
1545 unix_sk(other)->recursion_level = max_level;
1546 unix_state_unlock(other);
1547 other->sk_data_ready(other, len);
1548 sock_put(other);
1549 scm_destroy(siocb->scm);
1550 return len;
1551
1552out_unlock:
1553 unix_state_unlock(other);
1554out_free:
1555 kfree_skb(skb);
1556out:
1557 if (other)
1558 sock_put(other);
1559 scm_destroy(siocb->scm);
1560 return err;
1561}
1562
1563
1564static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1565 struct msghdr *msg, size_t len)
1566{
1567 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1568 struct sock *sk = sock->sk;
1569 struct sock *other = NULL;
1570 struct sockaddr_un *sunaddr = msg->msg_name;
1571 int err, size;
1572 struct sk_buff *skb;
1573 int sent = 0;
1574 struct scm_cookie tmp_scm;
1575 bool fds_sent = false;
1576 int max_level;
1577
1578 if (NULL == siocb->scm)
1579 siocb->scm = &tmp_scm;
1580 wait_for_unix_gc();
1581 err = scm_send(sock, msg, siocb->scm);
1582 if (err < 0)
1583 return err;
1584
1585 err = -EOPNOTSUPP;
1586 if (msg->msg_flags&MSG_OOB)
1587 goto out_err;
1588
1589 if (msg->msg_namelen) {
1590 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1591 goto out_err;
1592 } else {
1593 sunaddr = NULL;
1594 err = -ENOTCONN;
1595 other = unix_peer(sk);
1596 if (!other)
1597 goto out_err;
1598 }
1599
1600 if (sk->sk_shutdown & SEND_SHUTDOWN)
1601 goto pipe_err;
1602
1603 while (sent < len) {
1604 /*
1605 * Optimisation for the fact that under 0.01% of X
1606 * messages typically need breaking up.
1607 */
1608
1609 size = len-sent;
1610
1611 /* Keep two messages in the pipe so it schedules better */
1612 if (size > ((sk->sk_sndbuf >> 1) - 64))
1613 size = (sk->sk_sndbuf >> 1) - 64;
1614
1615 if (size > SKB_MAX_ALLOC)
1616 size = SKB_MAX_ALLOC;
1617
1618 /*
1619 * Grab a buffer
1620 */
1621
1622 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT,
1623 &err);
1624
1625 if (skb == NULL)
1626 goto out_err;
1627
1628 /*
1629 * If you pass two values to the sock_alloc_send_skb
1630 * it tries to grab the large buffer with GFP_NOFS
1631 * (which can fail easily), and if it fails grab the
1632 * fallback size buffer which is under a page and will
1633 * succeed. [Alan]
1634 */
1635 size = min_t(int, size, skb_tailroom(skb));
1636
1637
1638 /* Only send the fds in the first buffer */
1639 err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
1640 if (err < 0) {
1641 kfree_skb(skb);
1642 goto out_err;
1643 }
1644 max_level = err + 1;
1645 fds_sent = true;
1646
1647 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
1648 if (err) {
1649 kfree_skb(skb);
1650 goto out_err;
1651 }
1652
1653 unix_state_lock(other);
1654
1655 if (sock_flag(other, SOCK_DEAD) ||
1656 (other->sk_shutdown & RCV_SHUTDOWN))
1657 goto pipe_err_free;
1658
1659 skb_queue_tail(&other->sk_receive_queue, skb);
1660 if (max_level > unix_sk(other)->recursion_level)
1661 unix_sk(other)->recursion_level = max_level;
1662 unix_state_unlock(other);
1663 other->sk_data_ready(other, size);
1664 sent += size;
1665 }
1666
1667 scm_destroy(siocb->scm);
1668 siocb->scm = NULL;
1669
1670 return sent;
1671
1672pipe_err_free:
1673 unix_state_unlock(other);
1674 kfree_skb(skb);
1675pipe_err:
1676 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1677 send_sig(SIGPIPE, current, 0);
1678 err = -EPIPE;
1679out_err:
1680 scm_destroy(siocb->scm);
1681 siocb->scm = NULL;
1682 return sent ? : err;
1683}
1684
1685static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1686 struct msghdr *msg, size_t len)
1687{
1688 int err;
1689 struct sock *sk = sock->sk;
1690
1691 err = sock_error(sk);
1692 if (err)
1693 return err;
1694
1695 if (sk->sk_state != TCP_ESTABLISHED)
1696 return -ENOTCONN;
1697
1698 if (msg->msg_namelen)
1699 msg->msg_namelen = 0;
1700
1701 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1702}
1703
1704static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1705{
1706 struct unix_sock *u = unix_sk(sk);
1707
1708 msg->msg_namelen = 0;
1709 if (u->addr) {
1710 msg->msg_namelen = u->addr->len;
1711 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1712 }
1713}
1714
1715static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1716 struct msghdr *msg, size_t size,
1717 int flags)
1718{
1719 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1720 struct scm_cookie tmp_scm;
1721 struct sock *sk = sock->sk;
1722 struct unix_sock *u = unix_sk(sk);
1723 int noblock = flags & MSG_DONTWAIT;
1724 struct sk_buff *skb;
1725 int err;
1726
1727 err = -EOPNOTSUPP;
1728 if (flags&MSG_OOB)
1729 goto out;
1730
1731 msg->msg_namelen = 0;
1732
1733 mutex_lock(&u->readlock);
1734
1735 skb = skb_recv_datagram(sk, flags, noblock, &err);
1736 if (!skb) {
1737 unix_state_lock(sk);
1738 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1739 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1740 (sk->sk_shutdown & RCV_SHUTDOWN))
1741 err = 0;
1742 unix_state_unlock(sk);
1743 goto out_unlock;
1744 }
1745
1746 wake_up_interruptible_sync_poll(&u->peer_wait,
1747 POLLOUT | POLLWRNORM | POLLWRBAND);
1748
1749 if (msg->msg_name)
1750 unix_copy_addr(msg, skb->sk);
1751
1752 if (size > skb->len)
1753 size = skb->len;
1754 else if (size < skb->len)
1755 msg->msg_flags |= MSG_TRUNC;
1756
1757 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1758 if (err)
1759 goto out_free;
1760
1761 if (sock_flag(sk, SOCK_RCVTSTAMP))
1762 __sock_recv_timestamp(msg, sk, skb);
1763
1764 if (!siocb->scm) {
1765 siocb->scm = &tmp_scm;
1766 memset(&tmp_scm, 0, sizeof(tmp_scm));
1767 }
1768 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
1769 unix_set_secdata(siocb->scm, skb);
1770
1771 if (!(flags & MSG_PEEK)) {
1772 if (UNIXCB(skb).fp)
1773 unix_detach_fds(siocb->scm, skb);
1774 } else {
1775 /* It is questionable: on PEEK we could:
1776 - do not return fds - good, but too simple 8)
1777 - return fds, and do not return them on read (old strategy,
1778 apparently wrong)
1779 - clone fds (I chose it for now, it is the most universal
1780 solution)
1781
1782 POSIX 1003.1g does not actually define this clearly
1783 at all. POSIX 1003.1g doesn't define a lot of things
1784 clearly however!
1785
1786 */
1787 if (UNIXCB(skb).fp)
1788 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1789 }
1790 err = size;
1791
1792 scm_recv(sock, msg, siocb->scm, flags);
1793
1794out_free:
1795 skb_free_datagram(sk, skb);
1796out_unlock:
1797 mutex_unlock(&u->readlock);
1798out:
1799 return err;
1800}
1801
1802/*
1803 * Sleep until data has arrive. But check for races..
1804 */
1805
1806static long unix_stream_data_wait(struct sock *sk, long timeo)
1807{
1808 DEFINE_WAIT(wait);
1809
1810 unix_state_lock(sk);
1811
1812 for (;;) {
1813 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1814
1815 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1816 sk->sk_err ||
1817 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1818 signal_pending(current) ||
1819 !timeo)
1820 break;
1821
1822 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1823 unix_state_unlock(sk);
1824 timeo = schedule_timeout(timeo);
1825 unix_state_lock(sk);
1826 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1827 }
1828
1829 finish_wait(sk_sleep(sk), &wait);
1830 unix_state_unlock(sk);
1831 return timeo;
1832}
1833
1834
1835
1836static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1837 struct msghdr *msg, size_t size,
1838 int flags)
1839{
1840 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1841 struct scm_cookie tmp_scm;
1842 struct sock *sk = sock->sk;
1843 struct unix_sock *u = unix_sk(sk);
1844 struct sockaddr_un *sunaddr = msg->msg_name;
1845 int copied = 0;
1846 int check_creds = 0;
1847 int target;
1848 int err = 0;
1849 long timeo;
1850
1851 err = -EINVAL;
1852 if (sk->sk_state != TCP_ESTABLISHED)
1853 goto out;
1854
1855 err = -EOPNOTSUPP;
1856 if (flags&MSG_OOB)
1857 goto out;
1858
1859 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1860 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1861
1862 msg->msg_namelen = 0;
1863
1864 /* Lock the socket to prevent queue disordering
1865 * while sleeps in memcpy_tomsg
1866 */
1867
1868 if (!siocb->scm) {
1869 siocb->scm = &tmp_scm;
1870 memset(&tmp_scm, 0, sizeof(tmp_scm));
1871 }
1872
1873 mutex_lock(&u->readlock);
1874
1875 do {
1876 int chunk;
1877 struct sk_buff *skb;
1878
1879 unix_state_lock(sk);
1880 skb = skb_dequeue(&sk->sk_receive_queue);
1881 if (skb == NULL) {
1882 unix_sk(sk)->recursion_level = 0;
1883 if (copied >= target)
1884 goto unlock;
1885
1886 /*
1887 * POSIX 1003.1g mandates this order.
1888 */
1889
1890 err = sock_error(sk);
1891 if (err)
1892 goto unlock;
1893 if (sk->sk_shutdown & RCV_SHUTDOWN)
1894 goto unlock;
1895
1896 unix_state_unlock(sk);
1897 err = -EAGAIN;
1898 if (!timeo)
1899 break;
1900 mutex_unlock(&u->readlock);
1901
1902 timeo = unix_stream_data_wait(sk, timeo);
1903
1904 if (signal_pending(current)) {
1905 err = sock_intr_errno(timeo);
1906 goto out;
1907 }
1908 mutex_lock(&u->readlock);
1909 continue;
1910 unlock:
1911 unix_state_unlock(sk);
1912 break;
1913 }
1914 unix_state_unlock(sk);
1915
1916 if (check_creds) {
1917 /* Never glue messages from different writers */
1918 if ((UNIXCB(skb).pid != siocb->scm->pid) ||
1919 (UNIXCB(skb).cred != siocb->scm->cred)) {
1920 skb_queue_head(&sk->sk_receive_queue, skb);
1921 break;
1922 }
1923 } else {
1924 /* Copy credentials */
1925 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
1926 check_creds = 1;
1927 }
1928
1929 /* Copy address just once */
1930 if (sunaddr) {
1931 unix_copy_addr(msg, skb->sk);
1932 sunaddr = NULL;
1933 }
1934
1935 chunk = min_t(unsigned int, skb->len, size);
1936 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1937 skb_queue_head(&sk->sk_receive_queue, skb);
1938 if (copied == 0)
1939 copied = -EFAULT;
1940 break;
1941 }
1942 copied += chunk;
1943 size -= chunk;
1944
1945 /* Mark read part of skb as used */
1946 if (!(flags & MSG_PEEK)) {
1947 skb_pull(skb, chunk);
1948
1949 if (UNIXCB(skb).fp)
1950 unix_detach_fds(siocb->scm, skb);
1951
1952 /* put the skb back if we didn't use it up.. */
1953 if (skb->len) {
1954 skb_queue_head(&sk->sk_receive_queue, skb);
1955 break;
1956 }
1957
1958 consume_skb(skb);
1959
1960 if (siocb->scm->fp)
1961 break;
1962 } else {
1963 /* It is questionable, see note in unix_dgram_recvmsg.
1964 */
1965 if (UNIXCB(skb).fp)
1966 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1967
1968 /* put message back and return */
1969 skb_queue_head(&sk->sk_receive_queue, skb);
1970 break;
1971 }
1972 } while (size);
1973
1974 mutex_unlock(&u->readlock);
1975 scm_recv(sock, msg, siocb->scm, flags);
1976out:
1977 return copied ? : err;
1978}
1979
1980static int unix_shutdown(struct socket *sock, int mode)
1981{
1982 struct sock *sk = sock->sk;
1983 struct sock *other;
1984
1985 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1986
1987 if (mode) {
1988 unix_state_lock(sk);
1989 sk->sk_shutdown |= mode;
1990 other = unix_peer(sk);
1991 if (other)
1992 sock_hold(other);
1993 unix_state_unlock(sk);
1994 sk->sk_state_change(sk);
1995
1996 if (other &&
1997 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1998
1999 int peer_mode = 0;
2000
2001 if (mode&RCV_SHUTDOWN)
2002 peer_mode |= SEND_SHUTDOWN;
2003 if (mode&SEND_SHUTDOWN)
2004 peer_mode |= RCV_SHUTDOWN;
2005 unix_state_lock(other);
2006 other->sk_shutdown |= peer_mode;
2007 unix_state_unlock(other);
2008 other->sk_state_change(other);
2009 if (peer_mode == SHUTDOWN_MASK)
2010 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
2011 else if (peer_mode & RCV_SHUTDOWN)
2012 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
2013 }
2014 if (other)
2015 sock_put(other);
2016 }
2017 return 0;
2018}
2019
2020static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2021{
2022 struct sock *sk = sock->sk;
2023 long amount = 0;
2024 int err;
2025
2026 switch (cmd) {
2027 case SIOCOUTQ:
2028 amount = sk_wmem_alloc_get(sk);
2029 err = put_user(amount, (int __user *)arg);
2030 break;
2031 case SIOCINQ:
2032 {
2033 struct sk_buff *skb;
2034
2035 if (sk->sk_state == TCP_LISTEN) {
2036 err = -EINVAL;
2037 break;
2038 }
2039
2040 spin_lock(&sk->sk_receive_queue.lock);
2041 if (sk->sk_type == SOCK_STREAM ||
2042 sk->sk_type == SOCK_SEQPACKET) {
2043 skb_queue_walk(&sk->sk_receive_queue, skb)
2044 amount += skb->len;
2045 } else {
2046 skb = skb_peek(&sk->sk_receive_queue);
2047 if (skb)
2048 amount = skb->len;
2049 }
2050 spin_unlock(&sk->sk_receive_queue.lock);
2051 err = put_user(amount, (int __user *)arg);
2052 break;
2053 }
2054
2055 default:
2056 err = -ENOIOCTLCMD;
2057 break;
2058 }
2059 return err;
2060}
2061
2062static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait)
2063{
2064 struct sock *sk = sock->sk;
2065 unsigned int mask;
2066
2067 sock_poll_wait(file, sk_sleep(sk), wait);
2068 mask = 0;
2069
2070 /* exceptional events? */
2071 if (sk->sk_err)
2072 mask |= POLLERR;
2073 if (sk->sk_shutdown == SHUTDOWN_MASK)
2074 mask |= POLLHUP;
2075 if (sk->sk_shutdown & RCV_SHUTDOWN)
2076 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2077
2078 /* readable? */
2079 if (!skb_queue_empty(&sk->sk_receive_queue))
2080 mask |= POLLIN | POLLRDNORM;
2081
2082 /* Connection-based need to check for termination and startup */
2083 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2084 sk->sk_state == TCP_CLOSE)
2085 mask |= POLLHUP;
2086
2087 /*
2088 * we set writable also when the other side has shut down the
2089 * connection. This prevents stuck sockets.
2090 */
2091 if (unix_writable(sk))
2092 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2093
2094 return mask;
2095}
2096
2097static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2098 poll_table *wait)
2099{
2100 struct sock *sk = sock->sk, *other;
2101 unsigned int mask, writable;
2102
2103 sock_poll_wait(file, sk_sleep(sk), wait);
2104 mask = 0;
2105
2106 /* exceptional events? */
2107 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2108 mask |= POLLERR;
2109 if (sk->sk_shutdown & RCV_SHUTDOWN)
2110 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
2111 if (sk->sk_shutdown == SHUTDOWN_MASK)
2112 mask |= POLLHUP;
2113
2114 /* readable? */
2115 if (!skb_queue_empty(&sk->sk_receive_queue))
2116 mask |= POLLIN | POLLRDNORM;
2117
2118 /* Connection-based need to check for termination and startup */
2119 if (sk->sk_type == SOCK_SEQPACKET) {
2120 if (sk->sk_state == TCP_CLOSE)
2121 mask |= POLLHUP;
2122 /* connection hasn't started yet? */
2123 if (sk->sk_state == TCP_SYN_SENT)
2124 return mask;
2125 }
2126
2127 /* No write status requested, avoid expensive OUT tests. */
2128 if (wait && !(wait->key & (POLLWRBAND | POLLWRNORM | POLLOUT)))
2129 return mask;
2130
2131 writable = unix_writable(sk);
2132 other = unix_peer_get(sk);
2133 if (other) {
2134 if (unix_peer(other) != sk) {
2135 sock_poll_wait(file, &unix_sk(other)->peer_wait, wait);
2136 if (unix_recvq_full(other))
2137 writable = 0;
2138 }
2139 sock_put(other);
2140 }
2141
2142 if (writable)
2143 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2144 else
2145 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2146
2147 return mask;
2148}
2149
2150#ifdef CONFIG_PROC_FS
2151static struct sock *first_unix_socket(int *i)
2152{
2153 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
2154 if (!hlist_empty(&unix_socket_table[*i]))
2155 return __sk_head(&unix_socket_table[*i]);
2156 }
2157 return NULL;
2158}
2159
2160static struct sock *next_unix_socket(int *i, struct sock *s)
2161{
2162 struct sock *next = sk_next(s);
2163 /* More in this chain? */
2164 if (next)
2165 return next;
2166 /* Look for next non-empty chain. */
2167 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
2168 if (!hlist_empty(&unix_socket_table[*i]))
2169 return __sk_head(&unix_socket_table[*i]);
2170 }
2171 return NULL;
2172}
2173
2174struct unix_iter_state {
2175 struct seq_net_private p;
2176 int i;
2177};
2178
2179static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
2180{
2181 struct unix_iter_state *iter = seq->private;
2182 loff_t off = 0;
2183 struct sock *s;
2184
2185 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
2186 if (sock_net(s) != seq_file_net(seq))
2187 continue;
2188 if (off == pos)
2189 return s;
2190 ++off;
2191 }
2192 return NULL;
2193}
2194
2195static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2196 __acquires(unix_table_lock)
2197{
2198 spin_lock(&unix_table_lock);
2199 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2200}
2201
2202static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2203{
2204 struct unix_iter_state *iter = seq->private;
2205 struct sock *sk = v;
2206 ++*pos;
2207
2208 if (v == SEQ_START_TOKEN)
2209 sk = first_unix_socket(&iter->i);
2210 else
2211 sk = next_unix_socket(&iter->i, sk);
2212 while (sk && (sock_net(sk) != seq_file_net(seq)))
2213 sk = next_unix_socket(&iter->i, sk);
2214 return sk;
2215}
2216
2217static void unix_seq_stop(struct seq_file *seq, void *v)
2218 __releases(unix_table_lock)
2219{
2220 spin_unlock(&unix_table_lock);
2221}
2222
2223static int unix_seq_show(struct seq_file *seq, void *v)
2224{
2225
2226 if (v == SEQ_START_TOKEN)
2227 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2228 "Inode Path\n");
2229 else {
2230 struct sock *s = v;
2231 struct unix_sock *u = unix_sk(s);
2232 unix_state_lock(s);
2233
2234 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2235 s,
2236 atomic_read(&s->sk_refcnt),
2237 0,
2238 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2239 s->sk_type,
2240 s->sk_socket ?
2241 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2242 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2243 sock_i_ino(s));
2244
2245 if (u->addr) {
2246 int i, len;
2247 seq_putc(seq, ' ');
2248
2249 i = 0;
2250 len = u->addr->len - sizeof(short);
2251 if (!UNIX_ABSTRACT(s))
2252 len--;
2253 else {
2254 seq_putc(seq, '@');
2255 i++;
2256 }
2257 for ( ; i < len; i++)
2258 seq_putc(seq, u->addr->name->sun_path[i]);
2259 }
2260 unix_state_unlock(s);
2261 seq_putc(seq, '\n');
2262 }
2263
2264 return 0;
2265}
2266
2267static const struct seq_operations unix_seq_ops = {
2268 .start = unix_seq_start,
2269 .next = unix_seq_next,
2270 .stop = unix_seq_stop,
2271 .show = unix_seq_show,
2272};
2273
2274static int unix_seq_open(struct inode *inode, struct file *file)
2275{
2276 return seq_open_net(inode, file, &unix_seq_ops,
2277 sizeof(struct unix_iter_state));
2278}
2279
2280static const struct file_operations unix_seq_fops = {
2281 .owner = THIS_MODULE,
2282 .open = unix_seq_open,
2283 .read = seq_read,
2284 .llseek = seq_lseek,
2285 .release = seq_release_net,
2286};
2287
2288#endif
2289
2290static const struct net_proto_family unix_family_ops = {
2291 .family = PF_UNIX,
2292 .create = unix_create,
2293 .owner = THIS_MODULE,
2294};
2295
2296
2297static int __net_init unix_net_init(struct net *net)
2298{
2299 int error = -ENOMEM;
2300
2301 net->unx.sysctl_max_dgram_qlen = 10;
2302 if (unix_sysctl_register(net))
2303 goto out;
2304
2305#ifdef CONFIG_PROC_FS
2306 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2307 unix_sysctl_unregister(net);
2308 goto out;
2309 }
2310#endif
2311 error = 0;
2312out:
2313 return error;
2314}
2315
2316static void __net_exit unix_net_exit(struct net *net)
2317{
2318 unix_sysctl_unregister(net);
2319 proc_net_remove(net, "unix");
2320}
2321
2322static struct pernet_operations unix_net_ops = {
2323 .init = unix_net_init,
2324 .exit = unix_net_exit,
2325};
2326
2327static int __init af_unix_init(void)
2328{
2329 int rc = -1;
2330 struct sk_buff *dummy_skb;
2331
2332 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2333
2334 rc = proto_register(&unix_proto, 1);
2335 if (rc != 0) {
2336 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2337 __func__);
2338 goto out;
2339 }
2340
2341 sock_register(&unix_family_ops);
2342 register_pernet_subsys(&unix_net_ops);
2343out:
2344 return rc;
2345}
2346
2347static void __exit af_unix_exit(void)
2348{
2349 sock_unregister(PF_UNIX);
2350 proto_unregister(&unix_proto);
2351 unregister_pernet_subsys(&unix_net_ops);
2352}
2353
2354/* Earlier than device_initcall() so that other drivers invoking
2355 request_module() don't end up in a loop when modprobe tries
2356 to use a UNIX socket. But later than subsys_initcall() because
2357 we depend on stuff initialised there */
2358fs_initcall(af_unix_init);
2359module_exit(af_unix_exit);
2360
2361MODULE_LICENSE("GPL");
2362MODULE_ALIAS_NETPROTO(PF_UNIX);
kernel source for telekom puls (alcatel/mediatek)