blob: 87c0360eaa254e5ff4349a43710d39fd68d01f72 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
Alan Cox113aa832008-10-13 19:01:08 -07004 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#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>
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200104#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105#include <net/sock.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -0700106#include <net/tcp_states.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113#include <linux/rtnetlink.h>
114#include <linux/mount.h>
115#include <net/checksum.h>
116#include <linux/security.h>
117
Adrian Bunk13111692007-07-30 18:05:45 -0700118static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
119static DEFINE_SPINLOCK(unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120static atomic_t unix_nr_socks = ATOMIC_INIT(0);
121
122#define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE])
123
124#define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
125
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700126#ifdef CONFIG_SECURITY_NETWORK
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700127static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700128{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700130}
131
132static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
133{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700134 scm->secid = *UNIXSID(skb);
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700135}
136#else
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700137static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700138{ }
139
140static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
141{ }
142#endif /* CONFIG_SECURITY_NETWORK */
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144/*
145 * SMP locking strategy:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800146 * hash table is protected with spinlock unix_table_lock
Stephen Hemminger663717f2010-02-18 14:12:06 -0800147 * each socket state is protected by separate spin lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 */
149
Al Viro44bb9362006-11-14 21:36:14 -0800150static inline unsigned unix_hash_fold(__wsum n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
Al Viro44bb9362006-11-14 21:36:14 -0800152 unsigned hash = (__force unsigned)n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 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{
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800167 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
Rainer Weikusat3c734192008-06-17 22:28:05 -0700170static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175static struct sock *unix_peer_get(struct sock *s)
176{
177 struct sock *peer;
178
David S. Miller1c92b4e2007-05-31 13:24:26 -0700179 unix_state_lock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 peer = unix_peer(s);
181 if (peer)
182 sock_hold(peer);
David S. Miller1c92b4e2007-05-31 13:24:26 -0700183 unix_state_unlock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 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 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900199
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800200static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned *hashp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201{
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 */
Jianjun Konge27dfce2008-11-01 21:38:31 -0700214 ((char *)sunaddr)[len] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 len = strlen(sunaddr->sun_path)+1+sizeof(short);
216 return len;
217 }
218
Joe Perches07f07572008-11-19 15:44:53 -0800219 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 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{
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700230 WARN_ON(!sk_unhashed(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 sk_add_node(sk, list);
232}
233
234static inline void unix_remove_socket(struct sock *sk)
235{
David S. Millerfbe9cc42005-12-13 23:26:29 -0800236 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 __unix_remove_socket(sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800238 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
241static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
242{
David S. Millerfbe9cc42005-12-13 23:26:29 -0800243 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 __unix_insert_socket(list, sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800245 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800248static struct sock *__unix_find_socket_byname(struct net *net,
249 struct sockaddr_un *sunname,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 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
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900258 if (!net_eq(sock_net(s), net))
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800259 continue;
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 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
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800270static inline struct sock *unix_find_socket_byname(struct net *net,
271 struct sockaddr_un *sunname,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 int len, int type,
273 unsigned hash)
274{
275 struct sock *s;
276
David S. Millerfbe9cc42005-12-13 23:26:29 -0800277 spin_lock(&unix_table_lock);
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800278 s = __unix_find_socket_byname(net, sunname, len, type, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 if (s)
280 sock_hold(s);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800281 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 return s;
283}
284
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800285static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286{
287 struct sock *s;
288 struct hlist_node *node;
289
David S. Millerfbe9cc42005-12-13 23:26:29 -0800290 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 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
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900295 if (!net_eq(sock_net(s), net))
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800296 continue;
297
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800298 if (dentry && dentry->d_inode == i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 sock_hold(s);
300 goto found;
301 }
302 }
303 s = NULL;
304found:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800305 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 return s;
307}
308
309static inline int unix_writable(struct sock *sk)
310{
311 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
312}
313
314static void unix_write_space(struct sock *sk)
315{
316 read_lock(&sk->sk_callback_lock);
317 if (unix_writable(sk)) {
Jiri Olsaa57de0b2009-07-08 12:09:13 +0000318 if (sk_has_sleeper(sk))
Eric Dumazetaa395142010-04-20 13:03:51 +0000319 wake_up_interruptible_sync(sk_sleep(sk));
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +0800320 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 }
322 read_unlock(&sk->sk_callback_lock);
323}
324
325/* When dgram socket disconnects (or changes its peer), we clear its receive
326 * queue of packets arrived from previous peer. First, it allows to do
327 * flow control based only on wmem_alloc; second, sk connected to peer
328 * may receive messages only from that peer. */
329static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
330{
David S. Millerb03efcf2005-07-08 14:57:23 -0700331 if (!skb_queue_empty(&sk->sk_receive_queue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 skb_queue_purge(&sk->sk_receive_queue);
333 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
334
335 /* If one link of bidirectional dgram pipe is disconnected,
336 * we signal error. Messages are lost. Do not make this,
337 * when peer was not connected to us.
338 */
339 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
340 other->sk_err = ECONNRESET;
341 other->sk_error_report(other);
342 }
343 }
344}
345
346static void unix_sock_destructor(struct sock *sk)
347{
348 struct unix_sock *u = unix_sk(sk);
349
350 skb_queue_purge(&sk->sk_receive_queue);
351
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700352 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
353 WARN_ON(!sk_unhashed(sk));
354 WARN_ON(sk->sk_socket);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 if (!sock_flag(sk, SOCK_DEAD)) {
Eric Dumazet6b41e7d2008-11-19 15:48:09 -0800356 printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 return;
358 }
359
360 if (u->addr)
361 unix_release_addr(u->addr);
362
363 atomic_dec(&unix_nr_socks);
David S. Miller6f756a82008-11-23 17:34:03 -0800364 local_bh_disable();
Eric Dumazeta8076d82008-11-17 02:38:49 -0800365 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
David S. Miller6f756a82008-11-23 17:34:03 -0800366 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367#ifdef UNIX_REFCNT_DEBUG
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800368 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk,
369 atomic_read(&unix_nr_socks));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370#endif
371}
372
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800373static int unix_release_sock(struct sock *sk, int embrion)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374{
375 struct unix_sock *u = unix_sk(sk);
376 struct dentry *dentry;
377 struct vfsmount *mnt;
378 struct sock *skpair;
379 struct sk_buff *skb;
380 int state;
381
382 unix_remove_socket(sk);
383
384 /* Clear state */
David S. Miller1c92b4e2007-05-31 13:24:26 -0700385 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 sock_orphan(sk);
387 sk->sk_shutdown = SHUTDOWN_MASK;
388 dentry = u->dentry;
389 u->dentry = NULL;
390 mnt = u->mnt;
391 u->mnt = NULL;
392 state = sk->sk_state;
393 sk->sk_state = TCP_CLOSE;
David S. Miller1c92b4e2007-05-31 13:24:26 -0700394 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396 wake_up_interruptible_all(&u->peer_wait);
397
Jianjun Konge27dfce2008-11-01 21:38:31 -0700398 skpair = unix_peer(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
Jianjun Konge27dfce2008-11-01 21:38:31 -0700400 if (skpair != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
David S. Miller1c92b4e2007-05-31 13:24:26 -0700402 unix_state_lock(skpair);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 /* No more writes */
404 skpair->sk_shutdown = SHUTDOWN_MASK;
405 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
406 skpair->sk_err = ECONNRESET;
David S. Miller1c92b4e2007-05-31 13:24:26 -0700407 unix_state_unlock(skpair);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 skpair->sk_state_change(skpair);
409 read_lock(&skpair->sk_callback_lock);
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +0800410 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 read_unlock(&skpair->sk_callback_lock);
412 }
413 sock_put(skpair); /* It may now die */
414 unix_peer(sk) = NULL;
415 }
416
417 /* Try to flush out this socket. Throw out buffers at least */
418
419 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
Jianjun Konge27dfce2008-11-01 21:38:31 -0700420 if (state == TCP_LISTEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 unix_release_sock(skb->sk, 1);
422 /* passed fds are erased in the kfree_skb hook */
423 kfree_skb(skb);
424 }
425
426 if (dentry) {
427 dput(dentry);
428 mntput(mnt);
429 }
430
431 sock_put(sk);
432
433 /* ---- Socket is dead now and most probably destroyed ---- */
434
435 /*
436 * Fixme: BSD difference: In BSD all sockets connected to use get
437 * ECONNRESET and we die on the spot. In Linux we behave
438 * like files and pipes do and wait for the last
439 * dereference.
440 *
441 * Can't we simply set sock->err?
442 *
443 * What the above comment does talk about? --ANK(980817)
444 */
445
Pavel Emelyanov9305cfa2007-11-10 22:06:01 -0800446 if (unix_tot_inflight)
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900447 unix_gc(); /* Garbage collect fds */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
449 return 0;
450}
451
452static int unix_listen(struct socket *sock, int backlog)
453{
454 int err;
455 struct sock *sk = sock->sk;
456 struct unix_sock *u = unix_sk(sk);
457
458 err = -EOPNOTSUPP;
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800459 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
460 goto out; /* Only stream/seqpacket sockets accept */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 err = -EINVAL;
462 if (!u->addr)
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800463 goto out; /* No listens on an unbound socket */
David S. Miller1c92b4e2007-05-31 13:24:26 -0700464 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
466 goto out_unlock;
467 if (backlog > sk->sk_max_ack_backlog)
468 wake_up_interruptible_all(&u->peer_wait);
469 sk->sk_max_ack_backlog = backlog;
470 sk->sk_state = TCP_LISTEN;
471 /* set credentials so connect can copy them */
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700472 sk->sk_peercred.pid = task_tgid_vnr(current);
David Howells19d65622008-11-14 10:39:10 +1100473 current_euid_egid(&sk->sk_peercred.uid, &sk->sk_peercred.gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 err = 0;
475
476out_unlock:
David S. Miller1c92b4e2007-05-31 13:24:26 -0700477 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478out:
479 return err;
480}
481
482static int unix_release(struct socket *);
483static int unix_bind(struct socket *, struct sockaddr *, int);
484static int unix_stream_connect(struct socket *, struct sockaddr *,
485 int addr_len, int flags);
486static int unix_socketpair(struct socket *, struct socket *);
487static int unix_accept(struct socket *, struct socket *, int);
488static int unix_getname(struct socket *, struct sockaddr *, int *, int);
489static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700490static unsigned int unix_dgram_poll(struct file *, struct socket *,
491 poll_table *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492static int unix_ioctl(struct socket *, unsigned int, unsigned long);
493static int unix_shutdown(struct socket *, int);
494static int unix_stream_sendmsg(struct kiocb *, struct socket *,
495 struct msghdr *, size_t);
496static int unix_stream_recvmsg(struct kiocb *, struct socket *,
497 struct msghdr *, size_t, int);
498static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
499 struct msghdr *, size_t);
500static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
501 struct msghdr *, size_t, int);
502static int unix_dgram_connect(struct socket *, struct sockaddr *,
503 int, int);
504static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
505 struct msghdr *, size_t);
506
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800507static const struct proto_ops unix_stream_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 .family = PF_UNIX,
509 .owner = THIS_MODULE,
510 .release = unix_release,
511 .bind = unix_bind,
512 .connect = unix_stream_connect,
513 .socketpair = unix_socketpair,
514 .accept = unix_accept,
515 .getname = unix_getname,
516 .poll = unix_poll,
517 .ioctl = unix_ioctl,
518 .listen = unix_listen,
519 .shutdown = unix_shutdown,
520 .setsockopt = sock_no_setsockopt,
521 .getsockopt = sock_no_getsockopt,
522 .sendmsg = unix_stream_sendmsg,
523 .recvmsg = unix_stream_recvmsg,
524 .mmap = sock_no_mmap,
525 .sendpage = sock_no_sendpage,
526};
527
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800528static const struct proto_ops unix_dgram_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 .family = PF_UNIX,
530 .owner = THIS_MODULE,
531 .release = unix_release,
532 .bind = unix_bind,
533 .connect = unix_dgram_connect,
534 .socketpair = unix_socketpair,
535 .accept = sock_no_accept,
536 .getname = unix_getname,
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700537 .poll = unix_dgram_poll,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 .ioctl = unix_ioctl,
539 .listen = sock_no_listen,
540 .shutdown = unix_shutdown,
541 .setsockopt = sock_no_setsockopt,
542 .getsockopt = sock_no_getsockopt,
543 .sendmsg = unix_dgram_sendmsg,
544 .recvmsg = unix_dgram_recvmsg,
545 .mmap = sock_no_mmap,
546 .sendpage = sock_no_sendpage,
547};
548
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800549static const struct proto_ops unix_seqpacket_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 .family = PF_UNIX,
551 .owner = THIS_MODULE,
552 .release = unix_release,
553 .bind = unix_bind,
554 .connect = unix_stream_connect,
555 .socketpair = unix_socketpair,
556 .accept = unix_accept,
557 .getname = unix_getname,
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700558 .poll = unix_dgram_poll,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 .ioctl = unix_ioctl,
560 .listen = unix_listen,
561 .shutdown = unix_shutdown,
562 .setsockopt = sock_no_setsockopt,
563 .getsockopt = sock_no_getsockopt,
564 .sendmsg = unix_seqpacket_sendmsg,
565 .recvmsg = unix_dgram_recvmsg,
566 .mmap = sock_no_mmap,
567 .sendpage = sock_no_sendpage,
568};
569
570static struct proto unix_proto = {
Eric Dumazet248969a2008-11-17 00:00:30 -0800571 .name = "UNIX",
572 .owner = THIS_MODULE,
Eric Dumazet248969a2008-11-17 00:00:30 -0800573 .obj_size = sizeof(struct unix_sock),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574};
575
Ingo Molnara09785a2006-07-03 00:25:12 -0700576/*
577 * AF_UNIX sockets do not interact with hardware, hence they
578 * dont trigger interrupts - so it's safe for them to have
579 * bh-unsafe locking for their sk_receive_queue.lock. Split off
580 * this special lock-class by reinitializing the spinlock key:
581 */
582static struct lock_class_key af_unix_sk_receive_queue_lock_key;
583
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800584static struct sock *unix_create1(struct net *net, struct socket *sock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585{
586 struct sock *sk = NULL;
587 struct unix_sock *u;
588
Pavel Emelyanov284b3272007-11-10 22:08:30 -0800589 atomic_inc(&unix_nr_socks);
590 if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 goto out;
592
Pavel Emelyanov6257ff22007-11-01 00:39:31 -0700593 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 if (!sk)
595 goto out;
596
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800597 sock_init_data(sock, sk);
Ingo Molnara09785a2006-07-03 00:25:12 -0700598 lockdep_set_class(&sk->sk_receive_queue.lock,
599 &af_unix_sk_receive_queue_lock_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600
601 sk->sk_write_space = unix_write_space;
Denis V. Luneva0a53c82007-12-11 04:19:17 -0800602 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 sk->sk_destruct = unix_sock_destructor;
604 u = unix_sk(sk);
605 u->dentry = NULL;
606 u->mnt = NULL;
Benjamin LaHaisefd19f322006-01-03 14:10:46 -0800607 spin_lock_init(&u->lock);
Al Viro516e0cc2008-07-26 00:39:17 -0400608 atomic_long_set(&u->inflight, 0);
Miklos Szeredi1fd05ba2007-07-11 14:22:39 -0700609 INIT_LIST_HEAD(&u->link);
Ingo Molnar57b47a52006-03-20 22:35:41 -0800610 mutex_init(&u->readlock); /* single task reading lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 init_waitqueue_head(&u->peer_wait);
612 unix_insert_socket(unix_sockets_unbound, sk);
613out:
Pavel Emelyanov284b3272007-11-10 22:08:30 -0800614 if (sk == NULL)
615 atomic_dec(&unix_nr_socks);
Eric Dumazet920de802008-11-24 00:09:29 -0800616 else {
617 local_bh_disable();
Eric Dumazeta8076d82008-11-17 02:38:49 -0800618 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
Eric Dumazet920de802008-11-24 00:09:29 -0800619 local_bh_enable();
620 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 return sk;
622}
623
Eric Paris3f378b62009-11-05 22:18:14 -0800624static int unix_create(struct net *net, struct socket *sock, int protocol,
625 int kern)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626{
627 if (protocol && protocol != PF_UNIX)
628 return -EPROTONOSUPPORT;
629
630 sock->state = SS_UNCONNECTED;
631
632 switch (sock->type) {
633 case SOCK_STREAM:
634 sock->ops = &unix_stream_ops;
635 break;
636 /*
637 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
638 * nothing uses it.
639 */
640 case SOCK_RAW:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700641 sock->type = SOCK_DGRAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 case SOCK_DGRAM:
643 sock->ops = &unix_dgram_ops;
644 break;
645 case SOCK_SEQPACKET:
646 sock->ops = &unix_seqpacket_ops;
647 break;
648 default:
649 return -ESOCKTNOSUPPORT;
650 }
651
Eric W. Biederman1b8d7ae2007-10-08 23:24:22 -0700652 return unix_create1(net, sock) ? 0 : -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653}
654
655static int unix_release(struct socket *sock)
656{
657 struct sock *sk = sock->sk;
658
659 if (!sk)
660 return 0;
661
662 sock->sk = NULL;
663
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800664 return unix_release_sock(sk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665}
666
667static int unix_autobind(struct socket *sock)
668{
669 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900670 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 struct unix_sock *u = unix_sk(sk);
672 static u32 ordernum = 1;
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800673 struct unix_address *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 int err;
675
Ingo Molnar57b47a52006-03-20 22:35:41 -0800676 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678 err = 0;
679 if (u->addr)
680 goto out;
681
682 err = -ENOMEM;
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700683 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 if (!addr)
685 goto out;
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 addr->name->sun_family = AF_UNIX;
688 atomic_set(&addr->refcnt, 1);
689
690retry:
691 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
Joe Perches07f07572008-11-19 15:44:53 -0800692 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
David S. Millerfbe9cc42005-12-13 23:26:29 -0800694 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 ordernum = (ordernum+1)&0xFFFFF;
696
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800697 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 addr->hash)) {
David S. Millerfbe9cc42005-12-13 23:26:29 -0800699 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 /* Sanity yield. It is unusual case, but yet... */
701 if (!(ordernum&0xFF))
702 yield();
703 goto retry;
704 }
705 addr->hash ^= sk->sk_type;
706
707 __unix_remove_socket(sk);
708 u->addr = addr;
709 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800710 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 err = 0;
712
Ingo Molnar57b47a52006-03-20 22:35:41 -0800713out: mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 return err;
715}
716
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800717static struct sock *unix_find_other(struct net *net,
718 struct sockaddr_un *sunname, int len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 int type, unsigned hash, int *error)
720{
721 struct sock *u;
Al Viro421748e2008-08-02 01:04:36 -0400722 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 int err = 0;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 if (sunname->sun_path[0]) {
Al Viro421748e2008-08-02 01:04:36 -0400726 struct inode *inode;
727 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 if (err)
729 goto fail;
Al Viro421748e2008-08-02 01:04:36 -0400730 inode = path.dentry->d_inode;
731 err = inode_permission(inode, MAY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 if (err)
733 goto put_fail;
734
735 err = -ECONNREFUSED;
Al Viro421748e2008-08-02 01:04:36 -0400736 if (!S_ISSOCK(inode->i_mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 goto put_fail;
Al Viro421748e2008-08-02 01:04:36 -0400738 u = unix_find_socket_byinode(net, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 if (!u)
740 goto put_fail;
741
742 if (u->sk_type == type)
Al Viro421748e2008-08-02 01:04:36 -0400743 touch_atime(path.mnt, path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744
Al Viro421748e2008-08-02 01:04:36 -0400745 path_put(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746
Jianjun Konge27dfce2008-11-01 21:38:31 -0700747 err = -EPROTOTYPE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 if (u->sk_type != type) {
749 sock_put(u);
750 goto fail;
751 }
752 } else {
753 err = -ECONNREFUSED;
Jianjun Konge27dfce2008-11-01 21:38:31 -0700754 u = unix_find_socket_byname(net, sunname, len, type, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 if (u) {
756 struct dentry *dentry;
757 dentry = unix_sk(u)->dentry;
758 if (dentry)
759 touch_atime(unix_sk(u)->mnt, dentry);
760 } else
761 goto fail;
762 }
763 return u;
764
765put_fail:
Al Viro421748e2008-08-02 01:04:36 -0400766 path_put(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767fail:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700768 *error = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 return NULL;
770}
771
772
773static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
774{
775 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900776 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -0700778 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800779 struct dentry *dentry = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 struct nameidata nd;
781 int err;
782 unsigned hash;
783 struct unix_address *addr;
784 struct hlist_head *list;
785
786 err = -EINVAL;
787 if (sunaddr->sun_family != AF_UNIX)
788 goto out;
789
Jianjun Konge27dfce2008-11-01 21:38:31 -0700790 if (addr_len == sizeof(short)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 err = unix_autobind(sock);
792 goto out;
793 }
794
795 err = unix_mkname(sunaddr, addr_len, &hash);
796 if (err < 0)
797 goto out;
798 addr_len = err;
799
Ingo Molnar57b47a52006-03-20 22:35:41 -0800800 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802 err = -EINVAL;
803 if (u->addr)
804 goto out_up;
805
806 err = -ENOMEM;
807 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
808 if (!addr)
809 goto out_up;
810
811 memcpy(addr->name, sunaddr, addr_len);
812 addr->len = addr_len;
813 addr->hash = hash ^ sk->sk_type;
814 atomic_set(&addr->refcnt, 1);
815
816 if (sunaddr->sun_path[0]) {
817 unsigned int mode;
818 err = 0;
819 /*
820 * Get the parent directory, calculate the hash for last
821 * component.
822 */
823 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
824 if (err)
825 goto out_mknod_parent;
Christoph Hellwigf81a0bf2005-05-19 12:26:43 -0700826
827 dentry = lookup_create(&nd, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 err = PTR_ERR(dentry);
829 if (IS_ERR(dentry))
830 goto out_mknod_unlock;
Christoph Hellwigf81a0bf2005-05-19 12:26:43 -0700831
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 /*
833 * All right, let's create it.
834 */
835 mode = S_IFSOCK |
Al Viroce3b0f82009-03-29 19:08:22 -0400836 (SOCK_INODE(sock)->i_mode & ~current_umask());
Dave Hansen463c3192008-02-15 14:37:57 -0800837 err = mnt_want_write(nd.path.mnt);
838 if (err)
839 goto out_mknod_dput;
Kentaro Takedabe6d3e52008-12-17 13:24:15 +0900840 err = security_path_mknod(&nd.path, dentry, mode, 0);
841 if (err)
842 goto out_mknod_drop_write;
Jan Blunck4ac91372008-02-14 19:34:32 -0800843 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
Kentaro Takedabe6d3e52008-12-17 13:24:15 +0900844out_mknod_drop_write:
Dave Hansen463c3192008-02-15 14:37:57 -0800845 mnt_drop_write(nd.path.mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 if (err)
847 goto out_mknod_dput;
Jan Blunck4ac91372008-02-14 19:34:32 -0800848 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
849 dput(nd.path.dentry);
850 nd.path.dentry = dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
852 addr->hash = UNIX_HASH_SIZE;
853 }
854
David S. Millerfbe9cc42005-12-13 23:26:29 -0800855 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
857 if (!sunaddr->sun_path[0]) {
858 err = -EADDRINUSE;
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800859 if (__unix_find_socket_byname(net, sunaddr, addr_len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 sk->sk_type, hash)) {
861 unix_release_addr(addr);
862 goto out_unlock;
863 }
864
865 list = &unix_socket_table[addr->hash];
866 } else {
867 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
Jan Blunck4ac91372008-02-14 19:34:32 -0800868 u->dentry = nd.path.dentry;
869 u->mnt = nd.path.mnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 }
871
872 err = 0;
873 __unix_remove_socket(sk);
874 u->addr = addr;
875 __unix_insert_socket(list, sk);
876
877out_unlock:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800878 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879out_up:
Ingo Molnar57b47a52006-03-20 22:35:41 -0800880 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881out:
882 return err;
883
884out_mknod_dput:
885 dput(dentry);
886out_mknod_unlock:
Jan Blunck4ac91372008-02-14 19:34:32 -0800887 mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
Jan Blunck1d957f92008-02-14 19:34:35 -0800888 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889out_mknod_parent:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700890 if (err == -EEXIST)
891 err = -EADDRINUSE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 unix_release_addr(addr);
893 goto out_up;
894}
895
David S. Miller278a3de2007-05-31 15:19:20 -0700896static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
897{
898 if (unlikely(sk1 == sk2) || !sk2) {
899 unix_state_lock(sk1);
900 return;
901 }
902 if (sk1 < sk2) {
903 unix_state_lock(sk1);
904 unix_state_lock_nested(sk2);
905 } else {
906 unix_state_lock(sk2);
907 unix_state_lock_nested(sk1);
908 }
909}
910
911static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
912{
913 if (unlikely(sk1 == sk2) || !sk2) {
914 unix_state_unlock(sk1);
915 return;
916 }
917 unix_state_unlock(sk1);
918 unix_state_unlock(sk2);
919}
920
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
922 int alen, int flags)
923{
924 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900925 struct net *net = sock_net(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -0700926 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 struct sock *other;
928 unsigned hash;
929 int err;
930
931 if (addr->sa_family != AF_UNSPEC) {
932 err = unix_mkname(sunaddr, alen, &hash);
933 if (err < 0)
934 goto out;
935 alen = err;
936
937 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
938 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
939 goto out;
940
David S. Miller278a3de2007-05-31 15:19:20 -0700941restart:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700942 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 if (!other)
944 goto out;
945
David S. Miller278a3de2007-05-31 15:19:20 -0700946 unix_state_double_lock(sk, other);
947
948 /* Apparently VFS overslept socket death. Retry. */
949 if (sock_flag(other, SOCK_DEAD)) {
950 unix_state_double_unlock(sk, other);
951 sock_put(other);
952 goto restart;
953 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
955 err = -EPERM;
956 if (!unix_may_send(sk, other))
957 goto out_unlock;
958
959 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
960 if (err)
961 goto out_unlock;
962
963 } else {
964 /*
965 * 1003.1g breaking connected state with AF_UNSPEC
966 */
967 other = NULL;
David S. Miller278a3de2007-05-31 15:19:20 -0700968 unix_state_double_lock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 }
970
971 /*
972 * If it was connected, reconnect.
973 */
974 if (unix_peer(sk)) {
975 struct sock *old_peer = unix_peer(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -0700976 unix_peer(sk) = other;
David S. Miller278a3de2007-05-31 15:19:20 -0700977 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 if (other != old_peer)
980 unix_dgram_disconnected(sk, old_peer);
981 sock_put(old_peer);
982 } else {
Jianjun Konge27dfce2008-11-01 21:38:31 -0700983 unix_peer(sk) = other;
David S. Miller278a3de2007-05-31 15:19:20 -0700984 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 }
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900986 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
988out_unlock:
David S. Miller278a3de2007-05-31 15:19:20 -0700989 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 sock_put(other);
991out:
992 return err;
993}
994
995static long unix_wait_for_peer(struct sock *other, long timeo)
996{
997 struct unix_sock *u = unix_sk(other);
998 int sched;
999 DEFINE_WAIT(wait);
1000
1001 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1002
1003 sched = !sock_flag(other, SOCK_DEAD) &&
1004 !(other->sk_shutdown & RCV_SHUTDOWN) &&
Rainer Weikusat3c734192008-06-17 22:28:05 -07001005 unix_recvq_full(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
David S. Miller1c92b4e2007-05-31 13:24:26 -07001007 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008
1009 if (sched)
1010 timeo = schedule_timeout(timeo);
1011
1012 finish_wait(&u->peer_wait, &wait);
1013 return timeo;
1014}
1015
1016static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1017 int addr_len, int flags)
1018{
Jianjun Konge27dfce2008-11-01 21:38:31 -07001019 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001021 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1023 struct sock *newsk = NULL;
1024 struct sock *other = NULL;
1025 struct sk_buff *skb = NULL;
1026 unsigned hash;
1027 int st;
1028 int err;
1029 long timeo;
1030
1031 err = unix_mkname(sunaddr, addr_len, &hash);
1032 if (err < 0)
1033 goto out;
1034 addr_len = err;
1035
Joe Perchesf64f9e72009-11-29 16:55:45 -08001036 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1037 (err = unix_autobind(sock)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 goto out;
1039
1040 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1041
1042 /* First of all allocate resources.
1043 If we will make it after state is locked,
1044 we will have to recheck all again in any case.
1045 */
1046
1047 err = -ENOMEM;
1048
1049 /* create new sock for complete connection */
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001050 newsk = unix_create1(sock_net(sk), NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 if (newsk == NULL)
1052 goto out;
1053
1054 /* Allocate skb for sending to listening sock */
1055 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1056 if (skb == NULL)
1057 goto out;
1058
1059restart:
1060 /* Find listening sock. */
Denis V. Lunev097e66c2007-11-19 22:29:30 -08001061 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 if (!other)
1063 goto out;
1064
1065 /* Latch state of peer */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001066 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067
1068 /* Apparently VFS overslept socket death. Retry. */
1069 if (sock_flag(other, SOCK_DEAD)) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001070 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 sock_put(other);
1072 goto restart;
1073 }
1074
1075 err = -ECONNREFUSED;
1076 if (other->sk_state != TCP_LISTEN)
1077 goto out_unlock;
Tomoki Sekiyama77238f22009-10-18 23:17:37 -07001078 if (other->sk_shutdown & RCV_SHUTDOWN)
1079 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
Rainer Weikusat3c734192008-06-17 22:28:05 -07001081 if (unix_recvq_full(other)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 err = -EAGAIN;
1083 if (!timeo)
1084 goto out_unlock;
1085
1086 timeo = unix_wait_for_peer(other, timeo);
1087
1088 err = sock_intr_errno(timeo);
1089 if (signal_pending(current))
1090 goto out;
1091 sock_put(other);
1092 goto restart;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001093 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094
1095 /* Latch our state.
1096
1097 It is tricky place. We need to grab write lock and cannot
1098 drop lock on peer. It is dangerous because deadlock is
1099 possible. Connect to self case and simultaneous
1100 attempt to connect are eliminated by checking socket
1101 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1102 check this before attempt to grab lock.
1103
1104 Well, and we have to recheck the state after socket locked.
1105 */
1106 st = sk->sk_state;
1107
1108 switch (st) {
1109 case TCP_CLOSE:
1110 /* This is ok... continue with connect */
1111 break;
1112 case TCP_ESTABLISHED:
1113 /* Socket is already connected */
1114 err = -EISCONN;
1115 goto out_unlock;
1116 default:
1117 err = -EINVAL;
1118 goto out_unlock;
1119 }
1120
David S. Miller1c92b4e2007-05-31 13:24:26 -07001121 unix_state_lock_nested(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122
1123 if (sk->sk_state != st) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001124 unix_state_unlock(sk);
1125 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 sock_put(other);
1127 goto restart;
1128 }
1129
1130 err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1131 if (err) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001132 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 goto out_unlock;
1134 }
1135
1136 /* The way is open! Fastly set all the necessary fields... */
1137
1138 sock_hold(sk);
1139 unix_peer(newsk) = sk;
1140 newsk->sk_state = TCP_ESTABLISHED;
1141 newsk->sk_type = sk->sk_type;
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001142 newsk->sk_peercred.pid = task_tgid_vnr(current);
David Howells19d65622008-11-14 10:39:10 +11001143 current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 newu = unix_sk(newsk);
1145 newsk->sk_sleep = &newu->peer_wait;
1146 otheru = unix_sk(other);
1147
1148 /* copy address information from listening to new sock*/
1149 if (otheru->addr) {
1150 atomic_inc(&otheru->addr->refcnt);
1151 newu->addr = otheru->addr;
1152 }
1153 if (otheru->dentry) {
1154 newu->dentry = dget(otheru->dentry);
1155 newu->mnt = mntget(otheru->mnt);
1156 }
1157
1158 /* Set credentials */
1159 sk->sk_peercred = other->sk_peercred;
1160
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 sock->state = SS_CONNECTED;
1162 sk->sk_state = TCP_ESTABLISHED;
Benjamin LaHaise830a1e52005-12-13 23:22:32 -08001163 sock_hold(newsk);
1164
1165 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1166 unix_peer(sk) = newsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
David S. Miller1c92b4e2007-05-31 13:24:26 -07001168 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169
1170 /* take ten and and send info to listening sock */
1171 spin_lock(&other->sk_receive_queue.lock);
1172 __skb_queue_tail(&other->sk_receive_queue, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 spin_unlock(&other->sk_receive_queue.lock);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001174 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 other->sk_data_ready(other, 0);
1176 sock_put(other);
1177 return 0;
1178
1179out_unlock:
1180 if (other)
David S. Miller1c92b4e2007-05-31 13:24:26 -07001181 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182
1183out:
Wei Yongjun40d44442009-02-25 00:32:45 +00001184 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 if (newsk)
1186 unix_release_sock(newsk, 0);
1187 if (other)
1188 sock_put(other);
1189 return err;
1190}
1191
1192static int unix_socketpair(struct socket *socka, struct socket *sockb)
1193{
Jianjun Konge27dfce2008-11-01 21:38:31 -07001194 struct sock *ska = socka->sk, *skb = sockb->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195
1196 /* Join our sockets back to back */
1197 sock_hold(ska);
1198 sock_hold(skb);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001199 unix_peer(ska) = skb;
1200 unix_peer(skb) = ska;
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001201 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
David Howells19d65622008-11-14 10:39:10 +11001202 current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid);
1203 ska->sk_peercred.uid = skb->sk_peercred.uid;
1204 ska->sk_peercred.gid = skb->sk_peercred.gid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205
1206 if (ska->sk_type != SOCK_DGRAM) {
1207 ska->sk_state = TCP_ESTABLISHED;
1208 skb->sk_state = TCP_ESTABLISHED;
1209 socka->state = SS_CONNECTED;
1210 sockb->state = SS_CONNECTED;
1211 }
1212 return 0;
1213}
1214
1215static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1216{
1217 struct sock *sk = sock->sk;
1218 struct sock *tsk;
1219 struct sk_buff *skb;
1220 int err;
1221
1222 err = -EOPNOTSUPP;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001223 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 goto out;
1225
1226 err = -EINVAL;
1227 if (sk->sk_state != TCP_LISTEN)
1228 goto out;
1229
1230 /* If socket state is TCP_LISTEN it cannot change (for now...),
1231 * so that no locks are necessary.
1232 */
1233
1234 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1235 if (!skb) {
1236 /* This means receive shutdown. */
1237 if (err == 0)
1238 err = -EINVAL;
1239 goto out;
1240 }
1241
1242 tsk = skb->sk;
1243 skb_free_datagram(sk, skb);
1244 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1245
1246 /* attach accepted sock to socket */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001247 unix_state_lock(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 newsock->state = SS_CONNECTED;
1249 sock_graft(tsk, newsock);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001250 unix_state_unlock(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 return 0;
1252
1253out:
1254 return err;
1255}
1256
1257
1258static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1259{
1260 struct sock *sk = sock->sk;
1261 struct unix_sock *u;
Cyrill Gorcunov13cfa972009-11-08 05:51:19 +00001262 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 int err = 0;
1264
1265 if (peer) {
1266 sk = unix_peer_get(sk);
1267
1268 err = -ENOTCONN;
1269 if (!sk)
1270 goto out;
1271 err = 0;
1272 } else {
1273 sock_hold(sk);
1274 }
1275
1276 u = unix_sk(sk);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001277 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 if (!u->addr) {
1279 sunaddr->sun_family = AF_UNIX;
1280 sunaddr->sun_path[0] = 0;
1281 *uaddr_len = sizeof(short);
1282 } else {
1283 struct unix_address *addr = u->addr;
1284
1285 *uaddr_len = addr->len;
1286 memcpy(sunaddr, addr->name, *uaddr_len);
1287 }
David S. Miller1c92b4e2007-05-31 13:24:26 -07001288 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 sock_put(sk);
1290out:
1291 return err;
1292}
1293
1294static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1295{
1296 int i;
1297
1298 scm->fp = UNIXCB(skb).fp;
1299 skb->destructor = sock_wfree;
1300 UNIXCB(skb).fp = NULL;
1301
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001302 for (i = scm->fp->count-1; i >= 0; i--)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 unix_notinflight(scm->fp->fp[i]);
1304}
1305
1306static void unix_destruct_fds(struct sk_buff *skb)
1307{
1308 struct scm_cookie scm;
1309 memset(&scm, 0, sizeof(scm));
1310 unix_detach_fds(&scm, skb);
1311
1312 /* Alas, it calls VFS */
1313 /* So fscking what? fput() had been SMP-safe since the last Summer */
1314 scm_destroy(&scm);
1315 sock_wfree(skb);
1316}
1317
Miklos Szeredi62093442008-11-09 15:23:57 +01001318static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319{
1320 int i;
Miklos Szeredi62093442008-11-09 15:23:57 +01001321
1322 /*
1323 * Need to duplicate file references for the sake of garbage
1324 * collection. Otherwise a socket in the fps might become a
1325 * candidate for GC while the skb is not yet queued.
1326 */
1327 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1328 if (!UNIXCB(skb).fp)
1329 return -ENOMEM;
1330
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001331 for (i = scm->fp->count-1; i >= 0; i--)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 unix_inflight(scm->fp->fp[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 skb->destructor = unix_destruct_fds;
Miklos Szeredi62093442008-11-09 15:23:57 +01001334 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335}
1336
1337/*
1338 * Send AF_UNIX data.
1339 */
1340
1341static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1342 struct msghdr *msg, size_t len)
1343{
1344 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1345 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001346 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001348 struct sockaddr_un *sunaddr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 struct sock *other = NULL;
1350 int namelen = 0; /* fake GCC */
1351 int err;
1352 unsigned hash;
1353 struct sk_buff *skb;
1354 long timeo;
1355 struct scm_cookie tmp_scm;
1356
1357 if (NULL == siocb->scm)
1358 siocb->scm = &tmp_scm;
dann frazier5f23b732008-11-26 15:32:27 -08001359 wait_for_unix_gc();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 err = scm_send(sock, msg, siocb->scm);
1361 if (err < 0)
1362 return err;
1363
1364 err = -EOPNOTSUPP;
1365 if (msg->msg_flags&MSG_OOB)
1366 goto out;
1367
1368 if (msg->msg_namelen) {
1369 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1370 if (err < 0)
1371 goto out;
1372 namelen = err;
1373 } else {
1374 sunaddr = NULL;
1375 err = -ENOTCONN;
1376 other = unix_peer_get(sk);
1377 if (!other)
1378 goto out;
1379 }
1380
Joe Perchesf64f9e72009-11-29 16:55:45 -08001381 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1382 && (err = unix_autobind(sock)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 goto out;
1384
1385 err = -EMSGSIZE;
1386 if (len > sk->sk_sndbuf - 32)
1387 goto out;
1388
1389 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001390 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 goto out;
1392
1393 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
Miklos Szeredi62093442008-11-09 15:23:57 +01001394 if (siocb->scm->fp) {
1395 err = unix_attach_fds(siocb->scm, skb);
1396 if (err)
1397 goto out_free;
1398 }
Catherine Zhangdc49c1f2006-08-02 14:12:06 -07001399 unix_get_secdata(siocb->scm, skb);
Catherine Zhang877ce7c2006-06-29 12:27:47 -07001400
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -03001401 skb_reset_transport_header(skb);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001402 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 if (err)
1404 goto out_free;
1405
1406 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1407
1408restart:
1409 if (!other) {
1410 err = -ECONNRESET;
1411 if (sunaddr == NULL)
1412 goto out_free;
1413
Denis V. Lunev097e66c2007-11-19 22:29:30 -08001414 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 hash, &err);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001416 if (other == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 goto out_free;
1418 }
1419
David S. Miller1c92b4e2007-05-31 13:24:26 -07001420 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 err = -EPERM;
1422 if (!unix_may_send(sk, other))
1423 goto out_unlock;
1424
1425 if (sock_flag(other, SOCK_DEAD)) {
1426 /*
1427 * Check with 1003.1g - what should
1428 * datagram error
1429 */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001430 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 sock_put(other);
1432
1433 err = 0;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001434 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 if (unix_peer(sk) == other) {
Jianjun Konge27dfce2008-11-01 21:38:31 -07001436 unix_peer(sk) = NULL;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001437 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438
1439 unix_dgram_disconnected(sk, other);
1440 sock_put(other);
1441 err = -ECONNREFUSED;
1442 } else {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001443 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 }
1445
1446 other = NULL;
1447 if (err)
1448 goto out_free;
1449 goto restart;
1450 }
1451
1452 err = -EPIPE;
1453 if (other->sk_shutdown & RCV_SHUTDOWN)
1454 goto out_unlock;
1455
1456 if (sk->sk_type != SOCK_SEQPACKET) {
1457 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1458 if (err)
1459 goto out_unlock;
1460 }
1461
Rainer Weikusat3c734192008-06-17 22:28:05 -07001462 if (unix_peer(other) != sk && unix_recvq_full(other)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 if (!timeo) {
1464 err = -EAGAIN;
1465 goto out_unlock;
1466 }
1467
1468 timeo = unix_wait_for_peer(other, timeo);
1469
1470 err = sock_intr_errno(timeo);
1471 if (signal_pending(current))
1472 goto out_free;
1473
1474 goto restart;
1475 }
1476
1477 skb_queue_tail(&other->sk_receive_queue, skb);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001478 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 other->sk_data_ready(other, len);
1480 sock_put(other);
1481 scm_destroy(siocb->scm);
1482 return len;
1483
1484out_unlock:
David S. Miller1c92b4e2007-05-31 13:24:26 -07001485 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486out_free:
1487 kfree_skb(skb);
1488out:
1489 if (other)
1490 sock_put(other);
1491 scm_destroy(siocb->scm);
1492 return err;
1493}
1494
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001495
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1497 struct msghdr *msg, size_t len)
1498{
1499 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1500 struct sock *sk = sock->sk;
1501 struct sock *other = NULL;
Jianjun Konge27dfce2008-11-01 21:38:31 -07001502 struct sockaddr_un *sunaddr = msg->msg_name;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001503 int err, size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 struct sk_buff *skb;
Jianjun Konge27dfce2008-11-01 21:38:31 -07001505 int sent = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 struct scm_cookie tmp_scm;
Miklos Szeredi8ba69ba2009-09-11 11:31:45 -07001507 bool fds_sent = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508
1509 if (NULL == siocb->scm)
1510 siocb->scm = &tmp_scm;
dann frazier5f23b732008-11-26 15:32:27 -08001511 wait_for_unix_gc();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 err = scm_send(sock, msg, siocb->scm);
1513 if (err < 0)
1514 return err;
1515
1516 err = -EOPNOTSUPP;
1517 if (msg->msg_flags&MSG_OOB)
1518 goto out_err;
1519
1520 if (msg->msg_namelen) {
1521 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1522 goto out_err;
1523 } else {
1524 sunaddr = NULL;
1525 err = -ENOTCONN;
Benjamin LaHaise830a1e52005-12-13 23:22:32 -08001526 other = unix_peer(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 if (!other)
1528 goto out_err;
1529 }
1530
1531 if (sk->sk_shutdown & SEND_SHUTDOWN)
1532 goto pipe_err;
1533
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001534 while (sent < len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535 /*
Benjamin LaHaisee9df7d72006-03-20 21:29:05 -08001536 * Optimisation for the fact that under 0.01% of X
1537 * messages typically need breaking up.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538 */
1539
Benjamin LaHaisee9df7d72006-03-20 21:29:05 -08001540 size = len-sent;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001541
1542 /* Keep two messages in the pipe so it schedules better */
Benjamin LaHaisee9df7d72006-03-20 21:29:05 -08001543 if (size > ((sk->sk_sndbuf >> 1) - 64))
1544 size = (sk->sk_sndbuf >> 1) - 64;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545
1546 if (size > SKB_MAX_ALLOC)
1547 size = SKB_MAX_ALLOC;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001548
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 /*
1550 * Grab a buffer
1551 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001552
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001553 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT,
1554 &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555
Jianjun Konge27dfce2008-11-01 21:38:31 -07001556 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557 goto out_err;
1558
1559 /*
1560 * If you pass two values to the sock_alloc_send_skb
1561 * it tries to grab the large buffer with GFP_NOFS
1562 * (which can fail easily), and if it fails grab the
1563 * fallback size buffer which is under a page and will
1564 * succeed. [Alan]
1565 */
1566 size = min_t(int, size, skb_tailroom(skb));
1567
1568 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
Miklos Szeredi8ba69ba2009-09-11 11:31:45 -07001569 /* Only send the fds in the first buffer */
1570 if (siocb->scm->fp && !fds_sent) {
Miklos Szeredi62093442008-11-09 15:23:57 +01001571 err = unix_attach_fds(siocb->scm, skb);
1572 if (err) {
1573 kfree_skb(skb);
1574 goto out_err;
1575 }
Miklos Szeredi8ba69ba2009-09-11 11:31:45 -07001576 fds_sent = true;
Miklos Szeredi62093442008-11-09 15:23:57 +01001577 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001579 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
1580 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 kfree_skb(skb);
1582 goto out_err;
1583 }
1584
David S. Miller1c92b4e2007-05-31 13:24:26 -07001585 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586
1587 if (sock_flag(other, SOCK_DEAD) ||
1588 (other->sk_shutdown & RCV_SHUTDOWN))
1589 goto pipe_err_free;
1590
1591 skb_queue_tail(&other->sk_receive_queue, skb);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001592 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001593 other->sk_data_ready(other, size);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001594 sent += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596
1597 scm_destroy(siocb->scm);
1598 siocb->scm = NULL;
1599
1600 return sent;
1601
1602pipe_err_free:
David S. Miller1c92b4e2007-05-31 13:24:26 -07001603 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 kfree_skb(skb);
1605pipe_err:
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001606 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1607 send_sig(SIGPIPE, current, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 err = -EPIPE;
1609out_err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 scm_destroy(siocb->scm);
1611 siocb->scm = NULL;
1612 return sent ? : err;
1613}
1614
1615static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1616 struct msghdr *msg, size_t len)
1617{
1618 int err;
1619 struct sock *sk = sock->sk;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001620
Linus Torvalds1da177e2005-04-16 15:20:36 -07001621 err = sock_error(sk);
1622 if (err)
1623 return err;
1624
1625 if (sk->sk_state != TCP_ESTABLISHED)
1626 return -ENOTCONN;
1627
1628 if (msg->msg_namelen)
1629 msg->msg_namelen = 0;
1630
1631 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1632}
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001633
Linus Torvalds1da177e2005-04-16 15:20:36 -07001634static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1635{
1636 struct unix_sock *u = unix_sk(sk);
1637
1638 msg->msg_namelen = 0;
1639 if (u->addr) {
1640 msg->msg_namelen = u->addr->len;
1641 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1642 }
1643}
1644
1645static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1646 struct msghdr *msg, size_t size,
1647 int flags)
1648{
1649 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1650 struct scm_cookie tmp_scm;
1651 struct sock *sk = sock->sk;
1652 struct unix_sock *u = unix_sk(sk);
1653 int noblock = flags & MSG_DONTWAIT;
1654 struct sk_buff *skb;
1655 int err;
1656
1657 err = -EOPNOTSUPP;
1658 if (flags&MSG_OOB)
1659 goto out;
1660
1661 msg->msg_namelen = 0;
1662
Ingo Molnar57b47a52006-03-20 22:35:41 -08001663 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664
1665 skb = skb_recv_datagram(sk, flags, noblock, &err);
Florian Zumbiehl0a112252007-11-29 23:19:23 +11001666 if (!skb) {
1667 unix_state_lock(sk);
1668 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1669 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1670 (sk->sk_shutdown & RCV_SHUTDOWN))
1671 err = 0;
1672 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 goto out_unlock;
Florian Zumbiehl0a112252007-11-29 23:19:23 +11001674 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675
Ingo Molnar71e20f12007-10-15 17:00:19 +02001676 wake_up_interruptible_sync(&u->peer_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677
1678 if (msg->msg_name)
1679 unix_copy_addr(msg, skb->sk);
1680
1681 if (size > skb->len)
1682 size = skb->len;
1683 else if (size < skb->len)
1684 msg->msg_flags |= MSG_TRUNC;
1685
1686 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1687 if (err)
1688 goto out_free;
1689
1690 if (!siocb->scm) {
1691 siocb->scm = &tmp_scm;
1692 memset(&tmp_scm, 0, sizeof(tmp_scm));
1693 }
1694 siocb->scm->creds = *UNIXCREDS(skb);
Catherine Zhang877ce7c2006-06-29 12:27:47 -07001695 unix_set_secdata(siocb->scm, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001697 if (!(flags & MSG_PEEK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 if (UNIXCB(skb).fp)
1699 unix_detach_fds(siocb->scm, skb);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001700 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 /* It is questionable: on PEEK we could:
1702 - do not return fds - good, but too simple 8)
1703 - return fds, and do not return them on read (old strategy,
1704 apparently wrong)
1705 - clone fds (I chose it for now, it is the most universal
1706 solution)
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001707
1708 POSIX 1003.1g does not actually define this clearly
1709 at all. POSIX 1003.1g doesn't define a lot of things
1710 clearly however!
1711
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 */
1713 if (UNIXCB(skb).fp)
1714 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1715 }
1716 err = size;
1717
1718 scm_recv(sock, msg, siocb->scm, flags);
1719
1720out_free:
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001721 skb_free_datagram(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001722out_unlock:
Ingo Molnar57b47a52006-03-20 22:35:41 -08001723 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724out:
1725 return err;
1726}
1727
1728/*
1729 * Sleep until data has arrive. But check for races..
1730 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001731
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001732static long unix_stream_data_wait(struct sock *sk, long timeo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733{
1734 DEFINE_WAIT(wait);
1735
David S. Miller1c92b4e2007-05-31 13:24:26 -07001736 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737
1738 for (;;) {
Eric Dumazetaa395142010-04-20 13:03:51 +00001739 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740
David S. Millerb03efcf2005-07-08 14:57:23 -07001741 if (!skb_queue_empty(&sk->sk_receive_queue) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 sk->sk_err ||
1743 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1744 signal_pending(current) ||
1745 !timeo)
1746 break;
1747
1748 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001749 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 timeo = schedule_timeout(timeo);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001751 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1753 }
1754
Eric Dumazetaa395142010-04-20 13:03:51 +00001755 finish_wait(sk_sleep(sk), &wait);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001756 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 return timeo;
1758}
1759
1760
1761
1762static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1763 struct msghdr *msg, size_t size,
1764 int flags)
1765{
1766 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1767 struct scm_cookie tmp_scm;
1768 struct sock *sk = sock->sk;
1769 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001770 struct sockaddr_un *sunaddr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771 int copied = 0;
1772 int check_creds = 0;
1773 int target;
1774 int err = 0;
1775 long timeo;
1776
1777 err = -EINVAL;
1778 if (sk->sk_state != TCP_ESTABLISHED)
1779 goto out;
1780
1781 err = -EOPNOTSUPP;
1782 if (flags&MSG_OOB)
1783 goto out;
1784
1785 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1786 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1787
1788 msg->msg_namelen = 0;
1789
1790 /* Lock the socket to prevent queue disordering
1791 * while sleeps in memcpy_tomsg
1792 */
1793
1794 if (!siocb->scm) {
1795 siocb->scm = &tmp_scm;
1796 memset(&tmp_scm, 0, sizeof(tmp_scm));
1797 }
1798
Ingo Molnar57b47a52006-03-20 22:35:41 -08001799 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001801 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 int chunk;
1803 struct sk_buff *skb;
1804
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001805 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806 skb = skb_dequeue(&sk->sk_receive_queue);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001807 if (skb == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001808 if (copied >= target)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001809 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810
1811 /*
1812 * POSIX 1003.1g mandates this order.
1813 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001814
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001815 err = sock_error(sk);
1816 if (err)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001817 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 if (sk->sk_shutdown & RCV_SHUTDOWN)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001819 goto unlock;
1820
1821 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 err = -EAGAIN;
1823 if (!timeo)
1824 break;
Ingo Molnar57b47a52006-03-20 22:35:41 -08001825 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001826
1827 timeo = unix_stream_data_wait(sk, timeo);
1828
1829 if (signal_pending(current)) {
1830 err = sock_intr_errno(timeo);
1831 goto out;
1832 }
Ingo Molnar57b47a52006-03-20 22:35:41 -08001833 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 continue;
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001835 unlock:
1836 unix_state_unlock(sk);
1837 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 }
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001839 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840
1841 if (check_creds) {
1842 /* Never glue messages from different writers */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001843 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds,
1844 sizeof(siocb->scm->creds)) != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845 skb_queue_head(&sk->sk_receive_queue, skb);
1846 break;
1847 }
1848 } else {
1849 /* Copy credentials */
1850 siocb->scm->creds = *UNIXCREDS(skb);
1851 check_creds = 1;
1852 }
1853
1854 /* Copy address just once */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001855 if (sunaddr) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001856 unix_copy_addr(msg, skb->sk);
1857 sunaddr = NULL;
1858 }
1859
1860 chunk = min_t(unsigned int, skb->len, size);
1861 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1862 skb_queue_head(&sk->sk_receive_queue, skb);
1863 if (copied == 0)
1864 copied = -EFAULT;
1865 break;
1866 }
1867 copied += chunk;
1868 size -= chunk;
1869
1870 /* Mark read part of skb as used */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001871 if (!(flags & MSG_PEEK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872 skb_pull(skb, chunk);
1873
1874 if (UNIXCB(skb).fp)
1875 unix_detach_fds(siocb->scm, skb);
1876
1877 /* put the skb back if we didn't use it up.. */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001878 if (skb->len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 skb_queue_head(&sk->sk_receive_queue, skb);
1880 break;
1881 }
1882
1883 kfree_skb(skb);
1884
1885 if (siocb->scm->fp)
1886 break;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001887 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 /* It is questionable, see note in unix_dgram_recvmsg.
1889 */
1890 if (UNIXCB(skb).fp)
1891 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1892
1893 /* put message back and return */
1894 skb_queue_head(&sk->sk_receive_queue, skb);
1895 break;
1896 }
1897 } while (size);
1898
Ingo Molnar57b47a52006-03-20 22:35:41 -08001899 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 scm_recv(sock, msg, siocb->scm, flags);
1901out:
1902 return copied ? : err;
1903}
1904
1905static int unix_shutdown(struct socket *sock, int mode)
1906{
1907 struct sock *sk = sock->sk;
1908 struct sock *other;
1909
1910 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1911
1912 if (mode) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001913 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 sk->sk_shutdown |= mode;
Jianjun Konge27dfce2008-11-01 21:38:31 -07001915 other = unix_peer(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001916 if (other)
1917 sock_hold(other);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001918 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001919 sk->sk_state_change(sk);
1920
1921 if (other &&
1922 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1923
1924 int peer_mode = 0;
1925
1926 if (mode&RCV_SHUTDOWN)
1927 peer_mode |= SEND_SHUTDOWN;
1928 if (mode&SEND_SHUTDOWN)
1929 peer_mode |= RCV_SHUTDOWN;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001930 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001931 other->sk_shutdown |= peer_mode;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001932 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001933 other->sk_state_change(other);
1934 read_lock(&other->sk_callback_lock);
1935 if (peer_mode == SHUTDOWN_MASK)
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +08001936 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001937 else if (peer_mode & RCV_SHUTDOWN)
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +08001938 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 read_unlock(&other->sk_callback_lock);
1940 }
1941 if (other)
1942 sock_put(other);
1943 }
1944 return 0;
1945}
1946
1947static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1948{
1949 struct sock *sk = sock->sk;
Jianjun Konge27dfce2008-11-01 21:38:31 -07001950 long amount = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951 int err;
1952
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001953 switch (cmd) {
1954 case SIOCOUTQ:
Eric Dumazet31e6d362009-06-17 19:05:41 -07001955 amount = sk_wmem_alloc_get(sk);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001956 err = put_user(amount, (int __user *)arg);
1957 break;
1958 case SIOCINQ:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 {
1960 struct sk_buff *skb;
1961
1962 if (sk->sk_state == TCP_LISTEN) {
1963 err = -EINVAL;
1964 break;
1965 }
1966
1967 spin_lock(&sk->sk_receive_queue.lock);
1968 if (sk->sk_type == SOCK_STREAM ||
1969 sk->sk_type == SOCK_SEQPACKET) {
1970 skb_queue_walk(&sk->sk_receive_queue, skb)
1971 amount += skb->len;
1972 } else {
1973 skb = skb_peek(&sk->sk_receive_queue);
1974 if (skb)
Jianjun Konge27dfce2008-11-01 21:38:31 -07001975 amount = skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 }
1977 spin_unlock(&sk->sk_receive_queue.lock);
1978 err = put_user(amount, (int __user *)arg);
1979 break;
1980 }
1981
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001982 default:
1983 err = -ENOIOCTLCMD;
1984 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 }
1986 return err;
1987}
1988
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001989static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001990{
1991 struct sock *sk = sock->sk;
1992 unsigned int mask;
1993
Eric Dumazetaa395142010-04-20 13:03:51 +00001994 sock_poll_wait(file, sk_sleep(sk), wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995 mask = 0;
1996
1997 /* exceptional events? */
1998 if (sk->sk_err)
1999 mask |= POLLERR;
2000 if (sk->sk_shutdown == SHUTDOWN_MASK)
2001 mask |= POLLHUP;
Davide Libenzif348d702006-03-25 03:07:39 -08002002 if (sk->sk_shutdown & RCV_SHUTDOWN)
2003 mask |= POLLRDHUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004
2005 /* readable? */
2006 if (!skb_queue_empty(&sk->sk_receive_queue) ||
2007 (sk->sk_shutdown & RCV_SHUTDOWN))
2008 mask |= POLLIN | POLLRDNORM;
2009
2010 /* Connection-based need to check for termination and startup */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002011 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2012 sk->sk_state == TCP_CLOSE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002013 mask |= POLLHUP;
2014
2015 /*
2016 * we set writable also when the other side has shut down the
2017 * connection. This prevents stuck sockets.
2018 */
2019 if (unix_writable(sk))
2020 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2021
2022 return mask;
2023}
2024
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002025static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2026 poll_table *wait)
Rainer Weikusat3c734192008-06-17 22:28:05 -07002027{
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002028 struct sock *sk = sock->sk, *other;
2029 unsigned int mask, writable;
Rainer Weikusat3c734192008-06-17 22:28:05 -07002030
Eric Dumazetaa395142010-04-20 13:03:51 +00002031 sock_poll_wait(file, sk_sleep(sk), wait);
Rainer Weikusat3c734192008-06-17 22:28:05 -07002032 mask = 0;
2033
2034 /* exceptional events? */
2035 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2036 mask |= POLLERR;
2037 if (sk->sk_shutdown & RCV_SHUTDOWN)
2038 mask |= POLLRDHUP;
2039 if (sk->sk_shutdown == SHUTDOWN_MASK)
2040 mask |= POLLHUP;
2041
2042 /* readable? */
2043 if (!skb_queue_empty(&sk->sk_receive_queue) ||
2044 (sk->sk_shutdown & RCV_SHUTDOWN))
2045 mask |= POLLIN | POLLRDNORM;
2046
2047 /* Connection-based need to check for termination and startup */
2048 if (sk->sk_type == SOCK_SEQPACKET) {
2049 if (sk->sk_state == TCP_CLOSE)
2050 mask |= POLLHUP;
2051 /* connection hasn't started yet? */
2052 if (sk->sk_state == TCP_SYN_SENT)
2053 return mask;
2054 }
2055
2056 /* writable? */
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002057 writable = unix_writable(sk);
2058 if (writable) {
2059 other = unix_peer_get(sk);
2060 if (other) {
2061 if (unix_peer(other) != sk) {
Jiri Olsaa57de0b2009-07-08 12:09:13 +00002062 sock_poll_wait(file, &unix_sk(other)->peer_wait,
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002063 wait);
2064 if (unix_recvq_full(other))
2065 writable = 0;
2066 }
2067
2068 sock_put(other);
2069 }
2070 }
2071
2072 if (writable)
Rainer Weikusat3c734192008-06-17 22:28:05 -07002073 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2074 else
2075 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2076
Rainer Weikusat3c734192008-06-17 22:28:05 -07002077 return mask;
2078}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079
2080#ifdef CONFIG_PROC_FS
Pavel Emelyanova53eb3f2007-11-23 20:30:01 +08002081static struct sock *first_unix_socket(int *i)
2082{
2083 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
2084 if (!hlist_empty(&unix_socket_table[*i]))
2085 return __sk_head(&unix_socket_table[*i]);
2086 }
2087 return NULL;
2088}
2089
2090static struct sock *next_unix_socket(int *i, struct sock *s)
2091{
2092 struct sock *next = sk_next(s);
2093 /* More in this chain? */
2094 if (next)
2095 return next;
2096 /* Look for next non-empty chain. */
2097 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
2098 if (!hlist_empty(&unix_socket_table[*i]))
2099 return __sk_head(&unix_socket_table[*i]);
2100 }
2101 return NULL;
2102}
2103
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002104struct unix_iter_state {
Denis V. Luneve372c412007-11-19 22:31:54 -08002105 struct seq_net_private p;
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002106 int i;
2107};
Jianjun Konge27dfce2008-11-01 21:38:31 -07002108
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09002109static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002110{
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09002111 struct unix_iter_state *iter = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112 loff_t off = 0;
2113 struct sock *s;
2114
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002115 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09002116 if (sock_net(s) != seq_file_net(seq))
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002117 continue;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09002118 if (off == pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002119 return s;
2120 ++off;
2121 }
2122 return NULL;
2123}
2124
Linus Torvalds1da177e2005-04-16 15:20:36 -07002125static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08002126 __acquires(unix_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127{
David S. Millerfbe9cc42005-12-13 23:26:29 -08002128 spin_lock(&unix_table_lock);
Joe Perchesb9f31242008-04-12 19:04:38 -07002129 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002130}
2131
2132static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2133{
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002134 struct unix_iter_state *iter = seq->private;
2135 struct sock *sk = v;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136 ++*pos;
2137
Joe Perchesb9f31242008-04-12 19:04:38 -07002138 if (v == SEQ_START_TOKEN)
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002139 sk = first_unix_socket(&iter->i);
2140 else
2141 sk = next_unix_socket(&iter->i, sk);
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09002142 while (sk && (sock_net(sk) != seq_file_net(seq)))
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002143 sk = next_unix_socket(&iter->i, sk);
2144 return sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002145}
2146
2147static void unix_seq_stop(struct seq_file *seq, void *v)
Eric Dumazet9a429c42008-01-01 21:58:02 -08002148 __releases(unix_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002149{
David S. Millerfbe9cc42005-12-13 23:26:29 -08002150 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151}
2152
2153static int unix_seq_show(struct seq_file *seq, void *v)
2154{
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09002155
Joe Perchesb9f31242008-04-12 19:04:38 -07002156 if (v == SEQ_START_TOKEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2158 "Inode Path\n");
2159 else {
2160 struct sock *s = v;
2161 struct unix_sock *u = unix_sk(s);
David S. Miller1c92b4e2007-05-31 13:24:26 -07002162 unix_state_lock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163
2164 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2165 s,
2166 atomic_read(&s->sk_refcnt),
2167 0,
2168 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2169 s->sk_type,
2170 s->sk_socket ?
2171 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2172 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2173 sock_i_ino(s));
2174
2175 if (u->addr) {
2176 int i, len;
2177 seq_putc(seq, ' ');
2178
2179 i = 0;
2180 len = u->addr->len - sizeof(short);
2181 if (!UNIX_ABSTRACT(s))
2182 len--;
2183 else {
2184 seq_putc(seq, '@');
2185 i++;
2186 }
2187 for ( ; i < len; i++)
2188 seq_putc(seq, u->addr->name->sun_path[i]);
2189 }
David S. Miller1c92b4e2007-05-31 13:24:26 -07002190 unix_state_unlock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191 seq_putc(seq, '\n');
2192 }
2193
2194 return 0;
2195}
2196
Philippe De Muyter56b3d972007-07-10 23:07:31 -07002197static const struct seq_operations unix_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002198 .start = unix_seq_start,
2199 .next = unix_seq_next,
2200 .stop = unix_seq_stop,
2201 .show = unix_seq_show,
2202};
2203
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204static int unix_seq_open(struct inode *inode, struct file *file)
2205{
Denis V. Luneve372c412007-11-19 22:31:54 -08002206 return seq_open_net(inode, file, &unix_seq_ops,
2207 sizeof(struct unix_iter_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002208}
2209
Arjan van de Venda7071d2007-02-12 00:55:36 -08002210static const struct file_operations unix_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002211 .owner = THIS_MODULE,
2212 .open = unix_seq_open,
2213 .read = seq_read,
2214 .llseek = seq_lseek,
Denis V. Luneve372c412007-11-19 22:31:54 -08002215 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002216};
2217
2218#endif
2219
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +00002220static const struct net_proto_family unix_family_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002221 .family = PF_UNIX,
2222 .create = unix_create,
2223 .owner = THIS_MODULE,
2224};
2225
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002226
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00002227static int __net_init unix_net_init(struct net *net)
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002228{
2229 int error = -ENOMEM;
2230
Denis V. Luneva0a53c82007-12-11 04:19:17 -08002231 net->unx.sysctl_max_dgram_qlen = 10;
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002232 if (unix_sysctl_register(net))
2233 goto out;
Pavel Emelyanovd392e492007-12-01 23:44:15 +11002234
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002235#ifdef CONFIG_PROC_FS
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002236 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2237 unix_sysctl_unregister(net);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002238 goto out;
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002239 }
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002240#endif
2241 error = 0;
2242out:
Jianjun Kong48dcc332008-11-01 21:37:27 -07002243 return error;
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002244}
2245
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00002246static void __net_exit unix_net_exit(struct net *net)
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002247{
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002248 unix_sysctl_unregister(net);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002249 proc_net_remove(net, "unix");
2250}
2251
2252static struct pernet_operations unix_net_ops = {
2253 .init = unix_net_init,
2254 .exit = unix_net_exit,
2255};
2256
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257static int __init af_unix_init(void)
2258{
2259 int rc = -1;
2260 struct sk_buff *dummy_skb;
2261
YOSHIFUJI Hideakief047f52006-09-01 00:29:06 -07002262 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002263
2264 rc = proto_register(&unix_proto, 1);
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09002265 if (rc != 0) {
2266 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08002267 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002268 goto out;
2269 }
2270
2271 sock_register(&unix_family_ops);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002272 register_pernet_subsys(&unix_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273out:
2274 return rc;
2275}
2276
2277static void __exit af_unix_exit(void)
2278{
2279 sock_unregister(PF_UNIX);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280 proto_unregister(&unix_proto);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002281 unregister_pernet_subsys(&unix_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282}
2283
David Woodhouse3d366962008-04-24 00:59:25 -07002284/* Earlier than device_initcall() so that other drivers invoking
2285 request_module() don't end up in a loop when modprobe tries
2286 to use a UNIX socket. But later than subsys_initcall() because
2287 we depend on stuff initialised there */
2288fs_initcall(af_unix_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002289module_exit(af_unix_exit);
2290
2291MODULE_LICENSE("GPL");
2292MODULE_ALIAS_NETPROTO(PF_UNIX);