Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NET4: Implementation of BSD Unix domain sockets. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
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 | * | |
1da177e4 LT |
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> | |
1da177e4 | 84 | #include <linux/kernel.h> |
1da177e4 LT |
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> | |
457c4cbc | 104 | #include <net/net_namespace.h> |
1da177e4 | 105 | #include <net/sock.h> |
c752f073 | 106 | #include <net/tcp_states.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
113 | #include <linux/rtnetlink.h> |
114 | #include <linux/mount.h> | |
115 | #include <net/checksum.h> | |
116 | #include <linux/security.h> | |
117 | ||
fa7ff56f PE |
118 | struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; |
119 | EXPORT_SYMBOL_GPL(unix_socket_table); | |
120 | DEFINE_SPINLOCK(unix_table_lock); | |
121 | EXPORT_SYMBOL_GPL(unix_table_lock); | |
518de9b3 | 122 | static atomic_long_t unix_nr_socks; |
1da177e4 LT |
123 | |
124 | #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) | |
125 | ||
126 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE) | |
127 | ||
877ce7c1 | 128 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 129 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 130 | { |
dc49c1f9 | 131 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
877ce7c1 CZ |
132 | } |
133 | ||
134 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
135 | { | |
dc49c1f9 | 136 | scm->secid = *UNIXSID(skb); |
877ce7c1 CZ |
137 | } |
138 | #else | |
dc49c1f9 | 139 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
140 | { } |
141 | ||
142 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
143 | { } | |
144 | #endif /* CONFIG_SECURITY_NETWORK */ | |
145 | ||
1da177e4 LT |
146 | /* |
147 | * SMP locking strategy: | |
fbe9cc4a | 148 | * hash table is protected with spinlock unix_table_lock |
663717f6 | 149 | * each socket state is protected by separate spin lock. |
1da177e4 LT |
150 | */ |
151 | ||
95c96174 | 152 | static inline unsigned int unix_hash_fold(__wsum n) |
1da177e4 | 153 | { |
95c96174 ED |
154 | unsigned int hash = (__force unsigned int)n; |
155 | ||
1da177e4 LT |
156 | hash ^= hash>>16; |
157 | hash ^= hash>>8; | |
158 | return hash&(UNIX_HASH_SIZE-1); | |
159 | } | |
160 | ||
161 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
162 | ||
163 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
164 | { | |
165 | return unix_peer(osk) == sk; | |
166 | } | |
167 | ||
168 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
169 | { | |
6eba6a37 | 170 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
171 | } |
172 | ||
3c73419c RW |
173 | static inline int unix_recvq_full(struct sock const *sk) |
174 | { | |
175 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
176 | } | |
177 | ||
fa7ff56f | 178 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
179 | { |
180 | struct sock *peer; | |
181 | ||
1c92b4e5 | 182 | unix_state_lock(s); |
1da177e4 LT |
183 | peer = unix_peer(s); |
184 | if (peer) | |
185 | sock_hold(peer); | |
1c92b4e5 | 186 | unix_state_unlock(s); |
1da177e4 LT |
187 | return peer; |
188 | } | |
fa7ff56f | 189 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 LT |
190 | |
191 | static inline void unix_release_addr(struct unix_address *addr) | |
192 | { | |
193 | if (atomic_dec_and_test(&addr->refcnt)) | |
194 | kfree(addr); | |
195 | } | |
196 | ||
197 | /* | |
198 | * Check unix socket name: | |
199 | * - should be not zero length. | |
200 | * - if started by not zero, should be NULL terminated (FS object) | |
201 | * - if started by zero, it is abstract name. | |
202 | */ | |
ac7bfa62 | 203 | |
95c96174 | 204 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
1da177e4 LT |
205 | { |
206 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
207 | return -EINVAL; | |
208 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
209 | return -EINVAL; | |
210 | if (sunaddr->sun_path[0]) { | |
211 | /* | |
212 | * This may look like an off by one error but it is a bit more | |
213 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
25985edc | 214 | * sun_path[108] doesn't as such exist. However in kernel space |
1da177e4 LT |
215 | * we are guaranteed that it is a valid memory location in our |
216 | * kernel address buffer. | |
217 | */ | |
e27dfcea | 218 | ((char *)sunaddr)[len] = 0; |
1da177e4 LT |
219 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
220 | return len; | |
221 | } | |
222 | ||
07f0757a | 223 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
1da177e4 LT |
224 | return len; |
225 | } | |
226 | ||
227 | static void __unix_remove_socket(struct sock *sk) | |
228 | { | |
229 | sk_del_node_init(sk); | |
230 | } | |
231 | ||
232 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
233 | { | |
547b792c | 234 | WARN_ON(!sk_unhashed(sk)); |
1da177e4 LT |
235 | sk_add_node(sk, list); |
236 | } | |
237 | ||
238 | static inline void unix_remove_socket(struct sock *sk) | |
239 | { | |
fbe9cc4a | 240 | spin_lock(&unix_table_lock); |
1da177e4 | 241 | __unix_remove_socket(sk); |
fbe9cc4a | 242 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
243 | } |
244 | ||
245 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
246 | { | |
fbe9cc4a | 247 | spin_lock(&unix_table_lock); |
1da177e4 | 248 | __unix_insert_socket(list, sk); |
fbe9cc4a | 249 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
250 | } |
251 | ||
097e66c5 DL |
252 | static struct sock *__unix_find_socket_byname(struct net *net, |
253 | struct sockaddr_un *sunname, | |
95c96174 | 254 | int len, int type, unsigned int hash) |
1da177e4 LT |
255 | { |
256 | struct sock *s; | |
257 | struct hlist_node *node; | |
258 | ||
259 | sk_for_each(s, node, &unix_socket_table[hash ^ type]) { | |
260 | struct unix_sock *u = unix_sk(s); | |
261 | ||
878628fb | 262 | if (!net_eq(sock_net(s), net)) |
097e66c5 DL |
263 | continue; |
264 | ||
1da177e4 LT |
265 | if (u->addr->len == len && |
266 | !memcmp(u->addr->name, sunname, len)) | |
267 | goto found; | |
268 | } | |
269 | s = NULL; | |
270 | found: | |
271 | return s; | |
272 | } | |
273 | ||
097e66c5 DL |
274 | static inline struct sock *unix_find_socket_byname(struct net *net, |
275 | struct sockaddr_un *sunname, | |
1da177e4 | 276 | int len, int type, |
95c96174 | 277 | unsigned int hash) |
1da177e4 LT |
278 | { |
279 | struct sock *s; | |
280 | ||
fbe9cc4a | 281 | spin_lock(&unix_table_lock); |
097e66c5 | 282 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
283 | if (s) |
284 | sock_hold(s); | |
fbe9cc4a | 285 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
286 | return s; |
287 | } | |
288 | ||
6616f788 | 289 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 LT |
290 | { |
291 | struct sock *s; | |
292 | struct hlist_node *node; | |
293 | ||
fbe9cc4a | 294 | spin_lock(&unix_table_lock); |
1da177e4 LT |
295 | sk_for_each(s, node, |
296 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { | |
40ffe67d | 297 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 298 | |
6eba6a37 | 299 | if (dentry && dentry->d_inode == i) { |
1da177e4 LT |
300 | sock_hold(s); |
301 | goto found; | |
302 | } | |
303 | } | |
304 | s = NULL; | |
305 | found: | |
fbe9cc4a | 306 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
307 | return s; |
308 | } | |
309 | ||
310 | static inline int unix_writable(struct sock *sk) | |
311 | { | |
312 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
313 | } | |
314 | ||
315 | static void unix_write_space(struct sock *sk) | |
316 | { | |
43815482 ED |
317 | struct socket_wq *wq; |
318 | ||
319 | rcu_read_lock(); | |
1da177e4 | 320 | if (unix_writable(sk)) { |
43815482 ED |
321 | wq = rcu_dereference(sk->sk_wq); |
322 | if (wq_has_sleeper(wq)) | |
67426b75 ED |
323 | wake_up_interruptible_sync_poll(&wq->wait, |
324 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
8d8ad9d7 | 325 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 326 | } |
43815482 | 327 | rcu_read_unlock(); |
1da177e4 LT |
328 | } |
329 | ||
330 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
331 | * queue of packets arrived from previous peer. First, it allows to do | |
332 | * flow control based only on wmem_alloc; second, sk connected to peer | |
333 | * may receive messages only from that peer. */ | |
334 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
335 | { | |
b03efcfb | 336 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
337 | skb_queue_purge(&sk->sk_receive_queue); |
338 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
339 | ||
340 | /* If one link of bidirectional dgram pipe is disconnected, | |
341 | * we signal error. Messages are lost. Do not make this, | |
342 | * when peer was not connected to us. | |
343 | */ | |
344 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
345 | other->sk_err = ECONNRESET; | |
346 | other->sk_error_report(other); | |
347 | } | |
348 | } | |
349 | } | |
350 | ||
351 | static void unix_sock_destructor(struct sock *sk) | |
352 | { | |
353 | struct unix_sock *u = unix_sk(sk); | |
354 | ||
355 | skb_queue_purge(&sk->sk_receive_queue); | |
356 | ||
547b792c IJ |
357 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
358 | WARN_ON(!sk_unhashed(sk)); | |
359 | WARN_ON(sk->sk_socket); | |
1da177e4 | 360 | if (!sock_flag(sk, SOCK_DEAD)) { |
6b41e7dd | 361 | printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
362 | return; |
363 | } | |
364 | ||
365 | if (u->addr) | |
366 | unix_release_addr(u->addr); | |
367 | ||
518de9b3 | 368 | atomic_long_dec(&unix_nr_socks); |
6f756a8c | 369 | local_bh_disable(); |
a8076d8d | 370 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
6f756a8c | 371 | local_bh_enable(); |
1da177e4 | 372 | #ifdef UNIX_REFCNT_DEBUG |
518de9b3 ED |
373 | printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk, |
374 | atomic_long_read(&unix_nr_socks)); | |
1da177e4 LT |
375 | #endif |
376 | } | |
377 | ||
6eba6a37 | 378 | static int unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
379 | { |
380 | struct unix_sock *u = unix_sk(sk); | |
40ffe67d | 381 | struct path path; |
1da177e4 LT |
382 | struct sock *skpair; |
383 | struct sk_buff *skb; | |
384 | int state; | |
385 | ||
386 | unix_remove_socket(sk); | |
387 | ||
388 | /* Clear state */ | |
1c92b4e5 | 389 | unix_state_lock(sk); |
1da177e4 LT |
390 | sock_orphan(sk); |
391 | sk->sk_shutdown = SHUTDOWN_MASK; | |
40ffe67d AV |
392 | path = u->path; |
393 | u->path.dentry = NULL; | |
394 | u->path.mnt = NULL; | |
1da177e4 LT |
395 | state = sk->sk_state; |
396 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 397 | unix_state_unlock(sk); |
1da177e4 LT |
398 | |
399 | wake_up_interruptible_all(&u->peer_wait); | |
400 | ||
e27dfcea | 401 | skpair = unix_peer(sk); |
1da177e4 | 402 | |
e27dfcea | 403 | if (skpair != NULL) { |
1da177e4 | 404 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 405 | unix_state_lock(skpair); |
1da177e4 LT |
406 | /* No more writes */ |
407 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
408 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
409 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 410 | unix_state_unlock(skpair); |
1da177e4 | 411 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 412 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 LT |
413 | } |
414 | sock_put(skpair); /* It may now die */ | |
415 | unix_peer(sk) = NULL; | |
416 | } | |
417 | ||
418 | /* Try to flush out this socket. Throw out buffers at least */ | |
419 | ||
420 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 421 | if (state == TCP_LISTEN) |
1da177e4 LT |
422 | unix_release_sock(skb->sk, 1); |
423 | /* passed fds are erased in the kfree_skb hook */ | |
424 | kfree_skb(skb); | |
425 | } | |
426 | ||
40ffe67d AV |
427 | if (path.dentry) |
428 | path_put(&path); | |
1da177e4 LT |
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 | ||
9305cfa4 | 445 | if (unix_tot_inflight) |
ac7bfa62 | 446 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
447 | |
448 | return 0; | |
449 | } | |
450 | ||
109f6e39 EB |
451 | static 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 | ||
460 | static 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 | ||
1da177e4 LT |
469 | static 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); | |
109f6e39 EB |
474 | struct pid *old_pid = NULL; |
475 | const struct cred *old_cred = NULL; | |
1da177e4 LT |
476 | |
477 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
478 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
479 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
480 | err = -EINVAL; |
481 | if (!u->addr) | |
6eba6a37 | 482 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 483 | unix_state_lock(sk); |
1da177e4 LT |
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 */ | |
109f6e39 | 491 | init_peercred(sk); |
1da177e4 LT |
492 | err = 0; |
493 | ||
494 | out_unlock: | |
1c92b4e5 | 495 | unix_state_unlock(sk); |
109f6e39 EB |
496 | put_pid(old_pid); |
497 | if (old_cred) | |
498 | put_cred(old_cred); | |
1da177e4 LT |
499 | out: |
500 | return err; | |
501 | } | |
502 | ||
503 | static int unix_release(struct socket *); | |
504 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
505 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
506 | int addr_len, int flags); | |
507 | static int unix_socketpair(struct socket *, struct socket *); | |
508 | static int unix_accept(struct socket *, struct socket *, int); | |
509 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
510 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
ec0d215f RW |
511 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
512 | poll_table *); | |
1da177e4 LT |
513 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
514 | static int unix_shutdown(struct socket *, int); | |
515 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
516 | struct msghdr *, size_t); | |
517 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
518 | struct msghdr *, size_t, int); | |
519 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
520 | struct msghdr *, size_t); | |
521 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
522 | struct msghdr *, size_t, int); | |
523 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
524 | int, int); | |
525 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
526 | struct msghdr *, size_t); | |
a05d2ad1 EB |
527 | static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
528 | struct msghdr *, size_t, int); | |
1da177e4 | 529 | |
f55bb7f9 PE |
530 | static void unix_set_peek_off(struct sock *sk, int val) |
531 | { | |
532 | struct unix_sock *u = unix_sk(sk); | |
533 | ||
534 | mutex_lock(&u->readlock); | |
535 | sk->sk_peek_off = val; | |
536 | mutex_unlock(&u->readlock); | |
537 | } | |
538 | ||
539 | ||
90ddc4f0 | 540 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
541 | .family = PF_UNIX, |
542 | .owner = THIS_MODULE, | |
543 | .release = unix_release, | |
544 | .bind = unix_bind, | |
545 | .connect = unix_stream_connect, | |
546 | .socketpair = unix_socketpair, | |
547 | .accept = unix_accept, | |
548 | .getname = unix_getname, | |
549 | .poll = unix_poll, | |
550 | .ioctl = unix_ioctl, | |
551 | .listen = unix_listen, | |
552 | .shutdown = unix_shutdown, | |
553 | .setsockopt = sock_no_setsockopt, | |
554 | .getsockopt = sock_no_getsockopt, | |
555 | .sendmsg = unix_stream_sendmsg, | |
556 | .recvmsg = unix_stream_recvmsg, | |
557 | .mmap = sock_no_mmap, | |
558 | .sendpage = sock_no_sendpage, | |
fc0d7536 | 559 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
560 | }; |
561 | ||
90ddc4f0 | 562 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
563 | .family = PF_UNIX, |
564 | .owner = THIS_MODULE, | |
565 | .release = unix_release, | |
566 | .bind = unix_bind, | |
567 | .connect = unix_dgram_connect, | |
568 | .socketpair = unix_socketpair, | |
569 | .accept = sock_no_accept, | |
570 | .getname = unix_getname, | |
ec0d215f | 571 | .poll = unix_dgram_poll, |
1da177e4 LT |
572 | .ioctl = unix_ioctl, |
573 | .listen = sock_no_listen, | |
574 | .shutdown = unix_shutdown, | |
575 | .setsockopt = sock_no_setsockopt, | |
576 | .getsockopt = sock_no_getsockopt, | |
577 | .sendmsg = unix_dgram_sendmsg, | |
578 | .recvmsg = unix_dgram_recvmsg, | |
579 | .mmap = sock_no_mmap, | |
580 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 581 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
582 | }; |
583 | ||
90ddc4f0 | 584 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
585 | .family = PF_UNIX, |
586 | .owner = THIS_MODULE, | |
587 | .release = unix_release, | |
588 | .bind = unix_bind, | |
589 | .connect = unix_stream_connect, | |
590 | .socketpair = unix_socketpair, | |
591 | .accept = unix_accept, | |
592 | .getname = unix_getname, | |
ec0d215f | 593 | .poll = unix_dgram_poll, |
1da177e4 LT |
594 | .ioctl = unix_ioctl, |
595 | .listen = unix_listen, | |
596 | .shutdown = unix_shutdown, | |
597 | .setsockopt = sock_no_setsockopt, | |
598 | .getsockopt = sock_no_getsockopt, | |
599 | .sendmsg = unix_seqpacket_sendmsg, | |
a05d2ad1 | 600 | .recvmsg = unix_seqpacket_recvmsg, |
1da177e4 LT |
601 | .mmap = sock_no_mmap, |
602 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 603 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
604 | }; |
605 | ||
606 | static struct proto unix_proto = { | |
248969ae ED |
607 | .name = "UNIX", |
608 | .owner = THIS_MODULE, | |
248969ae | 609 | .obj_size = sizeof(struct unix_sock), |
1da177e4 LT |
610 | }; |
611 | ||
a09785a2 IM |
612 | /* |
613 | * AF_UNIX sockets do not interact with hardware, hence they | |
614 | * dont trigger interrupts - so it's safe for them to have | |
615 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
616 | * this special lock-class by reinitializing the spinlock key: | |
617 | */ | |
618 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
619 | ||
6eba6a37 | 620 | static struct sock *unix_create1(struct net *net, struct socket *sock) |
1da177e4 LT |
621 | { |
622 | struct sock *sk = NULL; | |
623 | struct unix_sock *u; | |
624 | ||
518de9b3 ED |
625 | atomic_long_inc(&unix_nr_socks); |
626 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) | |
1da177e4 LT |
627 | goto out; |
628 | ||
6257ff21 | 629 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
1da177e4 LT |
630 | if (!sk) |
631 | goto out; | |
632 | ||
6eba6a37 | 633 | sock_init_data(sock, sk); |
a09785a2 IM |
634 | lockdep_set_class(&sk->sk_receive_queue.lock, |
635 | &af_unix_sk_receive_queue_lock_key); | |
1da177e4 LT |
636 | |
637 | sk->sk_write_space = unix_write_space; | |
a0a53c8b | 638 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
1da177e4 LT |
639 | sk->sk_destruct = unix_sock_destructor; |
640 | u = unix_sk(sk); | |
40ffe67d AV |
641 | u->path.dentry = NULL; |
642 | u->path.mnt = NULL; | |
fd19f329 | 643 | spin_lock_init(&u->lock); |
516e0cc5 | 644 | atomic_long_set(&u->inflight, 0); |
1fd05ba5 | 645 | INIT_LIST_HEAD(&u->link); |
57b47a53 | 646 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 LT |
647 | init_waitqueue_head(&u->peer_wait); |
648 | unix_insert_socket(unix_sockets_unbound, sk); | |
649 | out: | |
284b327b | 650 | if (sk == NULL) |
518de9b3 | 651 | atomic_long_dec(&unix_nr_socks); |
920de804 ED |
652 | else { |
653 | local_bh_disable(); | |
a8076d8d | 654 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
920de804 ED |
655 | local_bh_enable(); |
656 | } | |
1da177e4 LT |
657 | return sk; |
658 | } | |
659 | ||
3f378b68 EP |
660 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
661 | int kern) | |
1da177e4 LT |
662 | { |
663 | if (protocol && protocol != PF_UNIX) | |
664 | return -EPROTONOSUPPORT; | |
665 | ||
666 | sock->state = SS_UNCONNECTED; | |
667 | ||
668 | switch (sock->type) { | |
669 | case SOCK_STREAM: | |
670 | sock->ops = &unix_stream_ops; | |
671 | break; | |
672 | /* | |
673 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
674 | * nothing uses it. | |
675 | */ | |
676 | case SOCK_RAW: | |
e27dfcea | 677 | sock->type = SOCK_DGRAM; |
1da177e4 LT |
678 | case SOCK_DGRAM: |
679 | sock->ops = &unix_dgram_ops; | |
680 | break; | |
681 | case SOCK_SEQPACKET: | |
682 | sock->ops = &unix_seqpacket_ops; | |
683 | break; | |
684 | default: | |
685 | return -ESOCKTNOSUPPORT; | |
686 | } | |
687 | ||
1b8d7ae4 | 688 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
1da177e4 LT |
689 | } |
690 | ||
691 | static int unix_release(struct socket *sock) | |
692 | { | |
693 | struct sock *sk = sock->sk; | |
694 | ||
695 | if (!sk) | |
696 | return 0; | |
697 | ||
698 | sock->sk = NULL; | |
699 | ||
6eba6a37 | 700 | return unix_release_sock(sk, 0); |
1da177e4 LT |
701 | } |
702 | ||
703 | static int unix_autobind(struct socket *sock) | |
704 | { | |
705 | struct sock *sk = sock->sk; | |
3b1e0a65 | 706 | struct net *net = sock_net(sk); |
1da177e4 LT |
707 | struct unix_sock *u = unix_sk(sk); |
708 | static u32 ordernum = 1; | |
6eba6a37 | 709 | struct unix_address *addr; |
1da177e4 | 710 | int err; |
8df73ff9 | 711 | unsigned int retries = 0; |
1da177e4 | 712 | |
57b47a53 | 713 | mutex_lock(&u->readlock); |
1da177e4 LT |
714 | |
715 | err = 0; | |
716 | if (u->addr) | |
717 | goto out; | |
718 | ||
719 | err = -ENOMEM; | |
0da974f4 | 720 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
721 | if (!addr) |
722 | goto out; | |
723 | ||
1da177e4 LT |
724 | addr->name->sun_family = AF_UNIX; |
725 | atomic_set(&addr->refcnt, 1); | |
726 | ||
727 | retry: | |
728 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
07f0757a | 729 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
1da177e4 | 730 | |
fbe9cc4a | 731 | spin_lock(&unix_table_lock); |
1da177e4 LT |
732 | ordernum = (ordernum+1)&0xFFFFF; |
733 | ||
097e66c5 | 734 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
1da177e4 | 735 | addr->hash)) { |
fbe9cc4a | 736 | spin_unlock(&unix_table_lock); |
8df73ff9 TH |
737 | /* |
738 | * __unix_find_socket_byname() may take long time if many names | |
739 | * are already in use. | |
740 | */ | |
741 | cond_resched(); | |
742 | /* Give up if all names seems to be in use. */ | |
743 | if (retries++ == 0xFFFFF) { | |
744 | err = -ENOSPC; | |
745 | kfree(addr); | |
746 | goto out; | |
747 | } | |
1da177e4 LT |
748 | goto retry; |
749 | } | |
750 | addr->hash ^= sk->sk_type; | |
751 | ||
752 | __unix_remove_socket(sk); | |
753 | u->addr = addr; | |
754 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 755 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
756 | err = 0; |
757 | ||
57b47a53 | 758 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
759 | return err; |
760 | } | |
761 | ||
097e66c5 DL |
762 | static struct sock *unix_find_other(struct net *net, |
763 | struct sockaddr_un *sunname, int len, | |
95c96174 | 764 | int type, unsigned int hash, int *error) |
1da177e4 LT |
765 | { |
766 | struct sock *u; | |
421748ec | 767 | struct path path; |
1da177e4 | 768 | int err = 0; |
ac7bfa62 | 769 | |
1da177e4 | 770 | if (sunname->sun_path[0]) { |
421748ec AV |
771 | struct inode *inode; |
772 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
1da177e4 LT |
773 | if (err) |
774 | goto fail; | |
421748ec AV |
775 | inode = path.dentry->d_inode; |
776 | err = inode_permission(inode, MAY_WRITE); | |
1da177e4 LT |
777 | if (err) |
778 | goto put_fail; | |
779 | ||
780 | err = -ECONNREFUSED; | |
421748ec | 781 | if (!S_ISSOCK(inode->i_mode)) |
1da177e4 | 782 | goto put_fail; |
6616f788 | 783 | u = unix_find_socket_byinode(inode); |
1da177e4 LT |
784 | if (!u) |
785 | goto put_fail; | |
786 | ||
787 | if (u->sk_type == type) | |
68ac1234 | 788 | touch_atime(&path); |
1da177e4 | 789 | |
421748ec | 790 | path_put(&path); |
1da177e4 | 791 | |
e27dfcea | 792 | err = -EPROTOTYPE; |
1da177e4 LT |
793 | if (u->sk_type != type) { |
794 | sock_put(u); | |
795 | goto fail; | |
796 | } | |
797 | } else { | |
798 | err = -ECONNREFUSED; | |
e27dfcea | 799 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
800 | if (u) { |
801 | struct dentry *dentry; | |
40ffe67d | 802 | dentry = unix_sk(u)->path.dentry; |
1da177e4 | 803 | if (dentry) |
68ac1234 | 804 | touch_atime(&unix_sk(u)->path); |
1da177e4 LT |
805 | } else |
806 | goto fail; | |
807 | } | |
808 | return u; | |
809 | ||
810 | put_fail: | |
421748ec | 811 | path_put(&path); |
1da177e4 | 812 | fail: |
e27dfcea | 813 | *error = err; |
1da177e4 LT |
814 | return NULL; |
815 | } | |
816 | ||
817 | ||
818 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
819 | { | |
820 | struct sock *sk = sock->sk; | |
3b1e0a65 | 821 | struct net *net = sock_net(sk); |
1da177e4 | 822 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 823 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
dae6ad8f | 824 | char *sun_path = sunaddr->sun_path; |
6eba6a37 | 825 | struct dentry *dentry = NULL; |
dae6ad8f | 826 | struct path path; |
1da177e4 | 827 | int err; |
95c96174 | 828 | unsigned int hash; |
1da177e4 LT |
829 | struct unix_address *addr; |
830 | struct hlist_head *list; | |
831 | ||
832 | err = -EINVAL; | |
833 | if (sunaddr->sun_family != AF_UNIX) | |
834 | goto out; | |
835 | ||
e27dfcea | 836 | if (addr_len == sizeof(short)) { |
1da177e4 LT |
837 | err = unix_autobind(sock); |
838 | goto out; | |
839 | } | |
840 | ||
841 | err = unix_mkname(sunaddr, addr_len, &hash); | |
842 | if (err < 0) | |
843 | goto out; | |
844 | addr_len = err; | |
845 | ||
57b47a53 | 846 | mutex_lock(&u->readlock); |
1da177e4 LT |
847 | |
848 | err = -EINVAL; | |
849 | if (u->addr) | |
850 | goto out_up; | |
851 | ||
852 | err = -ENOMEM; | |
853 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
854 | if (!addr) | |
855 | goto out_up; | |
856 | ||
857 | memcpy(addr->name, sunaddr, addr_len); | |
858 | addr->len = addr_len; | |
859 | addr->hash = hash ^ sk->sk_type; | |
860 | atomic_set(&addr->refcnt, 1); | |
861 | ||
dae6ad8f | 862 | if (sun_path[0]) { |
04fc66e7 | 863 | umode_t mode; |
1da177e4 LT |
864 | err = 0; |
865 | /* | |
866 | * Get the parent directory, calculate the hash for last | |
867 | * component. | |
868 | */ | |
dae6ad8f | 869 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); |
1da177e4 LT |
870 | err = PTR_ERR(dentry); |
871 | if (IS_ERR(dentry)) | |
dae6ad8f | 872 | goto out_mknod_parent; |
f81a0bff | 873 | |
1da177e4 LT |
874 | /* |
875 | * All right, let's create it. | |
876 | */ | |
877 | mode = S_IFSOCK | | |
ce3b0f8d | 878 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
dae6ad8f | 879 | err = mnt_want_write(path.mnt); |
463c3197 DH |
880 | if (err) |
881 | goto out_mknod_dput; | |
dae6ad8f | 882 | err = security_path_mknod(&path, dentry, mode, 0); |
be6d3e56 KT |
883 | if (err) |
884 | goto out_mknod_drop_write; | |
dae6ad8f | 885 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); |
be6d3e56 | 886 | out_mknod_drop_write: |
dae6ad8f | 887 | mnt_drop_write(path.mnt); |
1da177e4 LT |
888 | if (err) |
889 | goto out_mknod_dput; | |
dae6ad8f AV |
890 | mutex_unlock(&path.dentry->d_inode->i_mutex); |
891 | dput(path.dentry); | |
892 | path.dentry = dentry; | |
1da177e4 LT |
893 | |
894 | addr->hash = UNIX_HASH_SIZE; | |
895 | } | |
896 | ||
fbe9cc4a | 897 | spin_lock(&unix_table_lock); |
1da177e4 | 898 | |
dae6ad8f | 899 | if (!sun_path[0]) { |
1da177e4 | 900 | err = -EADDRINUSE; |
097e66c5 | 901 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
1da177e4 LT |
902 | sk->sk_type, hash)) { |
903 | unix_release_addr(addr); | |
904 | goto out_unlock; | |
905 | } | |
906 | ||
907 | list = &unix_socket_table[addr->hash]; | |
908 | } else { | |
909 | list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; | |
40ffe67d | 910 | u->path = path; |
1da177e4 LT |
911 | } |
912 | ||
913 | err = 0; | |
914 | __unix_remove_socket(sk); | |
915 | u->addr = addr; | |
916 | __unix_insert_socket(list, sk); | |
917 | ||
918 | out_unlock: | |
fbe9cc4a | 919 | spin_unlock(&unix_table_lock); |
1da177e4 | 920 | out_up: |
57b47a53 | 921 | mutex_unlock(&u->readlock); |
1da177e4 LT |
922 | out: |
923 | return err; | |
924 | ||
925 | out_mknod_dput: | |
926 | dput(dentry); | |
dae6ad8f AV |
927 | mutex_unlock(&path.dentry->d_inode->i_mutex); |
928 | path_put(&path); | |
1da177e4 | 929 | out_mknod_parent: |
e27dfcea JK |
930 | if (err == -EEXIST) |
931 | err = -EADDRINUSE; | |
1da177e4 LT |
932 | unix_release_addr(addr); |
933 | goto out_up; | |
934 | } | |
935 | ||
278a3de5 DM |
936 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
937 | { | |
938 | if (unlikely(sk1 == sk2) || !sk2) { | |
939 | unix_state_lock(sk1); | |
940 | return; | |
941 | } | |
942 | if (sk1 < sk2) { | |
943 | unix_state_lock(sk1); | |
944 | unix_state_lock_nested(sk2); | |
945 | } else { | |
946 | unix_state_lock(sk2); | |
947 | unix_state_lock_nested(sk1); | |
948 | } | |
949 | } | |
950 | ||
951 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
952 | { | |
953 | if (unlikely(sk1 == sk2) || !sk2) { | |
954 | unix_state_unlock(sk1); | |
955 | return; | |
956 | } | |
957 | unix_state_unlock(sk1); | |
958 | unix_state_unlock(sk2); | |
959 | } | |
960 | ||
1da177e4 LT |
961 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
962 | int alen, int flags) | |
963 | { | |
964 | struct sock *sk = sock->sk; | |
3b1e0a65 | 965 | struct net *net = sock_net(sk); |
e27dfcea | 966 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
1da177e4 | 967 | struct sock *other; |
95c96174 | 968 | unsigned int hash; |
1da177e4 LT |
969 | int err; |
970 | ||
971 | if (addr->sa_family != AF_UNSPEC) { | |
972 | err = unix_mkname(sunaddr, alen, &hash); | |
973 | if (err < 0) | |
974 | goto out; | |
975 | alen = err; | |
976 | ||
977 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
978 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
979 | goto out; | |
980 | ||
278a3de5 | 981 | restart: |
e27dfcea | 982 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
1da177e4 LT |
983 | if (!other) |
984 | goto out; | |
985 | ||
278a3de5 DM |
986 | unix_state_double_lock(sk, other); |
987 | ||
988 | /* Apparently VFS overslept socket death. Retry. */ | |
989 | if (sock_flag(other, SOCK_DEAD)) { | |
990 | unix_state_double_unlock(sk, other); | |
991 | sock_put(other); | |
992 | goto restart; | |
993 | } | |
1da177e4 LT |
994 | |
995 | err = -EPERM; | |
996 | if (!unix_may_send(sk, other)) | |
997 | goto out_unlock; | |
998 | ||
999 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1000 | if (err) | |
1001 | goto out_unlock; | |
1002 | ||
1003 | } else { | |
1004 | /* | |
1005 | * 1003.1g breaking connected state with AF_UNSPEC | |
1006 | */ | |
1007 | other = NULL; | |
278a3de5 | 1008 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1009 | } |
1010 | ||
1011 | /* | |
1012 | * If it was connected, reconnect. | |
1013 | */ | |
1014 | if (unix_peer(sk)) { | |
1015 | struct sock *old_peer = unix_peer(sk); | |
e27dfcea | 1016 | unix_peer(sk) = other; |
278a3de5 | 1017 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1018 | |
1019 | if (other != old_peer) | |
1020 | unix_dgram_disconnected(sk, old_peer); | |
1021 | sock_put(old_peer); | |
1022 | } else { | |
e27dfcea | 1023 | unix_peer(sk) = other; |
278a3de5 | 1024 | unix_state_double_unlock(sk, other); |
1da177e4 | 1025 | } |
ac7bfa62 | 1026 | return 0; |
1da177e4 LT |
1027 | |
1028 | out_unlock: | |
278a3de5 | 1029 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1030 | sock_put(other); |
1031 | out: | |
1032 | return err; | |
1033 | } | |
1034 | ||
1035 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1036 | { | |
1037 | struct unix_sock *u = unix_sk(other); | |
1038 | int sched; | |
1039 | DEFINE_WAIT(wait); | |
1040 | ||
1041 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1042 | ||
1043 | sched = !sock_flag(other, SOCK_DEAD) && | |
1044 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
3c73419c | 1045 | unix_recvq_full(other); |
1da177e4 | 1046 | |
1c92b4e5 | 1047 | unix_state_unlock(other); |
1da177e4 LT |
1048 | |
1049 | if (sched) | |
1050 | timeo = schedule_timeout(timeo); | |
1051 | ||
1052 | finish_wait(&u->peer_wait, &wait); | |
1053 | return timeo; | |
1054 | } | |
1055 | ||
1056 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1057 | int addr_len, int flags) | |
1058 | { | |
e27dfcea | 1059 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1da177e4 | 1060 | struct sock *sk = sock->sk; |
3b1e0a65 | 1061 | struct net *net = sock_net(sk); |
1da177e4 LT |
1062 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1063 | struct sock *newsk = NULL; | |
1064 | struct sock *other = NULL; | |
1065 | struct sk_buff *skb = NULL; | |
95c96174 | 1066 | unsigned int hash; |
1da177e4 LT |
1067 | int st; |
1068 | int err; | |
1069 | long timeo; | |
1070 | ||
1071 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1072 | if (err < 0) | |
1073 | goto out; | |
1074 | addr_len = err; | |
1075 | ||
f64f9e71 JP |
1076 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
1077 | (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1078 | goto out; |
1079 | ||
1080 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1081 | ||
1082 | /* First of all allocate resources. | |
1083 | If we will make it after state is locked, | |
1084 | we will have to recheck all again in any case. | |
1085 | */ | |
1086 | ||
1087 | err = -ENOMEM; | |
1088 | ||
1089 | /* create new sock for complete connection */ | |
3b1e0a65 | 1090 | newsk = unix_create1(sock_net(sk), NULL); |
1da177e4 LT |
1091 | if (newsk == NULL) |
1092 | goto out; | |
1093 | ||
1094 | /* Allocate skb for sending to listening sock */ | |
1095 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1096 | if (skb == NULL) | |
1097 | goto out; | |
1098 | ||
1099 | restart: | |
1100 | /* Find listening sock. */ | |
097e66c5 | 1101 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1da177e4 LT |
1102 | if (!other) |
1103 | goto out; | |
1104 | ||
1105 | /* Latch state of peer */ | |
1c92b4e5 | 1106 | unix_state_lock(other); |
1da177e4 LT |
1107 | |
1108 | /* Apparently VFS overslept socket death. Retry. */ | |
1109 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1110 | unix_state_unlock(other); |
1da177e4 LT |
1111 | sock_put(other); |
1112 | goto restart; | |
1113 | } | |
1114 | ||
1115 | err = -ECONNREFUSED; | |
1116 | if (other->sk_state != TCP_LISTEN) | |
1117 | goto out_unlock; | |
77238f2b TS |
1118 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1119 | goto out_unlock; | |
1da177e4 | 1120 | |
3c73419c | 1121 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1122 | err = -EAGAIN; |
1123 | if (!timeo) | |
1124 | goto out_unlock; | |
1125 | ||
1126 | timeo = unix_wait_for_peer(other, timeo); | |
1127 | ||
1128 | err = sock_intr_errno(timeo); | |
1129 | if (signal_pending(current)) | |
1130 | goto out; | |
1131 | sock_put(other); | |
1132 | goto restart; | |
ac7bfa62 | 1133 | } |
1da177e4 LT |
1134 | |
1135 | /* Latch our state. | |
1136 | ||
e5537bfc | 1137 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1138 | drop lock on peer. It is dangerous because deadlock is |
1139 | possible. Connect to self case and simultaneous | |
1140 | attempt to connect are eliminated by checking socket | |
1141 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1142 | check this before attempt to grab lock. | |
1143 | ||
1144 | Well, and we have to recheck the state after socket locked. | |
1145 | */ | |
1146 | st = sk->sk_state; | |
1147 | ||
1148 | switch (st) { | |
1149 | case TCP_CLOSE: | |
1150 | /* This is ok... continue with connect */ | |
1151 | break; | |
1152 | case TCP_ESTABLISHED: | |
1153 | /* Socket is already connected */ | |
1154 | err = -EISCONN; | |
1155 | goto out_unlock; | |
1156 | default: | |
1157 | err = -EINVAL; | |
1158 | goto out_unlock; | |
1159 | } | |
1160 | ||
1c92b4e5 | 1161 | unix_state_lock_nested(sk); |
1da177e4 LT |
1162 | |
1163 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1164 | unix_state_unlock(sk); |
1165 | unix_state_unlock(other); | |
1da177e4 LT |
1166 | sock_put(other); |
1167 | goto restart; | |
1168 | } | |
1169 | ||
3610cda5 | 1170 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1171 | if (err) { |
1c92b4e5 | 1172 | unix_state_unlock(sk); |
1da177e4 LT |
1173 | goto out_unlock; |
1174 | } | |
1175 | ||
1176 | /* The way is open! Fastly set all the necessary fields... */ | |
1177 | ||
1178 | sock_hold(sk); | |
1179 | unix_peer(newsk) = sk; | |
1180 | newsk->sk_state = TCP_ESTABLISHED; | |
1181 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1182 | init_peercred(newsk); |
1da177e4 | 1183 | newu = unix_sk(newsk); |
eaefd110 | 1184 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1185 | otheru = unix_sk(other); |
1186 | ||
1187 | /* copy address information from listening to new sock*/ | |
1188 | if (otheru->addr) { | |
1189 | atomic_inc(&otheru->addr->refcnt); | |
1190 | newu->addr = otheru->addr; | |
1191 | } | |
40ffe67d AV |
1192 | if (otheru->path.dentry) { |
1193 | path_get(&otheru->path); | |
1194 | newu->path = otheru->path; | |
1da177e4 LT |
1195 | } |
1196 | ||
1197 | /* Set credentials */ | |
109f6e39 | 1198 | copy_peercred(sk, other); |
1da177e4 | 1199 | |
1da177e4 LT |
1200 | sock->state = SS_CONNECTED; |
1201 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1202 | sock_hold(newsk); |
1203 | ||
1204 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1205 | unix_peer(sk) = newsk; | |
1da177e4 | 1206 | |
1c92b4e5 | 1207 | unix_state_unlock(sk); |
1da177e4 LT |
1208 | |
1209 | /* take ten and and send info to listening sock */ | |
1210 | spin_lock(&other->sk_receive_queue.lock); | |
1211 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1212 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1213 | unix_state_unlock(other); |
1da177e4 LT |
1214 | other->sk_data_ready(other, 0); |
1215 | sock_put(other); | |
1216 | return 0; | |
1217 | ||
1218 | out_unlock: | |
1219 | if (other) | |
1c92b4e5 | 1220 | unix_state_unlock(other); |
1da177e4 LT |
1221 | |
1222 | out: | |
40d44446 | 1223 | kfree_skb(skb); |
1da177e4 LT |
1224 | if (newsk) |
1225 | unix_release_sock(newsk, 0); | |
1226 | if (other) | |
1227 | sock_put(other); | |
1228 | return err; | |
1229 | } | |
1230 | ||
1231 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1232 | { | |
e27dfcea | 1233 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1234 | |
1235 | /* Join our sockets back to back */ | |
1236 | sock_hold(ska); | |
1237 | sock_hold(skb); | |
e27dfcea JK |
1238 | unix_peer(ska) = skb; |
1239 | unix_peer(skb) = ska; | |
109f6e39 EB |
1240 | init_peercred(ska); |
1241 | init_peercred(skb); | |
1da177e4 LT |
1242 | |
1243 | if (ska->sk_type != SOCK_DGRAM) { | |
1244 | ska->sk_state = TCP_ESTABLISHED; | |
1245 | skb->sk_state = TCP_ESTABLISHED; | |
1246 | socka->state = SS_CONNECTED; | |
1247 | sockb->state = SS_CONNECTED; | |
1248 | } | |
1249 | return 0; | |
1250 | } | |
1251 | ||
1252 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) | |
1253 | { | |
1254 | struct sock *sk = sock->sk; | |
1255 | struct sock *tsk; | |
1256 | struct sk_buff *skb; | |
1257 | int err; | |
1258 | ||
1259 | err = -EOPNOTSUPP; | |
6eba6a37 | 1260 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1261 | goto out; |
1262 | ||
1263 | err = -EINVAL; | |
1264 | if (sk->sk_state != TCP_LISTEN) | |
1265 | goto out; | |
1266 | ||
1267 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1268 | * so that no locks are necessary. | |
1269 | */ | |
1270 | ||
1271 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1272 | if (!skb) { | |
1273 | /* This means receive shutdown. */ | |
1274 | if (err == 0) | |
1275 | err = -EINVAL; | |
1276 | goto out; | |
1277 | } | |
1278 | ||
1279 | tsk = skb->sk; | |
1280 | skb_free_datagram(sk, skb); | |
1281 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1282 | ||
1283 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1284 | unix_state_lock(tsk); |
1da177e4 LT |
1285 | newsock->state = SS_CONNECTED; |
1286 | sock_graft(tsk, newsock); | |
1c92b4e5 | 1287 | unix_state_unlock(tsk); |
1da177e4 LT |
1288 | return 0; |
1289 | ||
1290 | out: | |
1291 | return err; | |
1292 | } | |
1293 | ||
1294 | ||
1295 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1296 | { | |
1297 | struct sock *sk = sock->sk; | |
1298 | struct unix_sock *u; | |
13cfa97b | 1299 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1300 | int err = 0; |
1301 | ||
1302 | if (peer) { | |
1303 | sk = unix_peer_get(sk); | |
1304 | ||
1305 | err = -ENOTCONN; | |
1306 | if (!sk) | |
1307 | goto out; | |
1308 | err = 0; | |
1309 | } else { | |
1310 | sock_hold(sk); | |
1311 | } | |
1312 | ||
1313 | u = unix_sk(sk); | |
1c92b4e5 | 1314 | unix_state_lock(sk); |
1da177e4 LT |
1315 | if (!u->addr) { |
1316 | sunaddr->sun_family = AF_UNIX; | |
1317 | sunaddr->sun_path[0] = 0; | |
1318 | *uaddr_len = sizeof(short); | |
1319 | } else { | |
1320 | struct unix_address *addr = u->addr; | |
1321 | ||
1322 | *uaddr_len = addr->len; | |
1323 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1324 | } | |
1c92b4e5 | 1325 | unix_state_unlock(sk); |
1da177e4 LT |
1326 | sock_put(sk); |
1327 | out: | |
1328 | return err; | |
1329 | } | |
1330 | ||
1331 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1332 | { | |
1333 | int i; | |
1334 | ||
1335 | scm->fp = UNIXCB(skb).fp; | |
1da177e4 LT |
1336 | UNIXCB(skb).fp = NULL; |
1337 | ||
6eba6a37 | 1338 | for (i = scm->fp->count-1; i >= 0; i--) |
1da177e4 LT |
1339 | unix_notinflight(scm->fp->fp[i]); |
1340 | } | |
1341 | ||
7361c36c | 1342 | static void unix_destruct_scm(struct sk_buff *skb) |
1da177e4 LT |
1343 | { |
1344 | struct scm_cookie scm; | |
1345 | memset(&scm, 0, sizeof(scm)); | |
7361c36c EB |
1346 | scm.pid = UNIXCB(skb).pid; |
1347 | scm.cred = UNIXCB(skb).cred; | |
1348 | if (UNIXCB(skb).fp) | |
1349 | unix_detach_fds(&scm, skb); | |
1da177e4 LT |
1350 | |
1351 | /* Alas, it calls VFS */ | |
1352 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1353 | scm_destroy(&scm); | |
1354 | sock_wfree(skb); | |
1355 | } | |
1356 | ||
25888e30 ED |
1357 | #define MAX_RECURSION_LEVEL 4 |
1358 | ||
6209344f | 1359 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1da177e4 LT |
1360 | { |
1361 | int i; | |
25888e30 ED |
1362 | unsigned char max_level = 0; |
1363 | int unix_sock_count = 0; | |
1364 | ||
1365 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1366 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1367 | ||
1368 | if (sk) { | |
1369 | unix_sock_count++; | |
1370 | max_level = max(max_level, | |
1371 | unix_sk(sk)->recursion_level); | |
1372 | } | |
1373 | } | |
1374 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1375 | return -ETOOMANYREFS; | |
6209344f MS |
1376 | |
1377 | /* | |
1378 | * Need to duplicate file references for the sake of garbage | |
1379 | * collection. Otherwise a socket in the fps might become a | |
1380 | * candidate for GC while the skb is not yet queued. | |
1381 | */ | |
1382 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1383 | if (!UNIXCB(skb).fp) | |
1384 | return -ENOMEM; | |
1385 | ||
25888e30 ED |
1386 | if (unix_sock_count) { |
1387 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1388 | unix_inflight(scm->fp->fp[i]); | |
1389 | } | |
1390 | return max_level; | |
1da177e4 LT |
1391 | } |
1392 | ||
f78a5fda | 1393 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1394 | { |
1395 | int err = 0; | |
16e57262 | 1396 | |
f78a5fda | 1397 | UNIXCB(skb).pid = get_pid(scm->pid); |
16e57262 ED |
1398 | if (scm->cred) |
1399 | UNIXCB(skb).cred = get_cred(scm->cred); | |
7361c36c EB |
1400 | UNIXCB(skb).fp = NULL; |
1401 | if (scm->fp && send_fds) | |
1402 | err = unix_attach_fds(scm, skb); | |
1403 | ||
1404 | skb->destructor = unix_destruct_scm; | |
1405 | return err; | |
1406 | } | |
1407 | ||
16e57262 ED |
1408 | /* |
1409 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1410 | * We include credentials if source or destination socket | |
1411 | * asserted SOCK_PASSCRED. | |
1412 | */ | |
1413 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1414 | const struct sock *other) | |
1415 | { | |
1416 | if (UNIXCB(skb).cred) | |
1417 | return; | |
1418 | if (test_bit(SOCK_PASSCRED, &sock->flags) || | |
1419 | !other->sk_socket || | |
1420 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { | |
1421 | UNIXCB(skb).pid = get_pid(task_tgid(current)); | |
1422 | UNIXCB(skb).cred = get_current_cred(); | |
1423 | } | |
1424 | } | |
1425 | ||
1da177e4 LT |
1426 | /* |
1427 | * Send AF_UNIX data. | |
1428 | */ | |
1429 | ||
1430 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1431 | struct msghdr *msg, size_t len) | |
1432 | { | |
1433 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1434 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1435 | struct net *net = sock_net(sk); |
1da177e4 | 1436 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 1437 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1438 | struct sock *other = NULL; |
1439 | int namelen = 0; /* fake GCC */ | |
1440 | int err; | |
95c96174 | 1441 | unsigned int hash; |
f78a5fda | 1442 | struct sk_buff *skb; |
1da177e4 LT |
1443 | long timeo; |
1444 | struct scm_cookie tmp_scm; | |
25888e30 | 1445 | int max_level; |
eb6a2481 | 1446 | int data_len = 0; |
1da177e4 LT |
1447 | |
1448 | if (NULL == siocb->scm) | |
1449 | siocb->scm = &tmp_scm; | |
5f23b734 | 1450 | wait_for_unix_gc(); |
1da177e4 LT |
1451 | err = scm_send(sock, msg, siocb->scm); |
1452 | if (err < 0) | |
1453 | return err; | |
1454 | ||
1455 | err = -EOPNOTSUPP; | |
1456 | if (msg->msg_flags&MSG_OOB) | |
1457 | goto out; | |
1458 | ||
1459 | if (msg->msg_namelen) { | |
1460 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1461 | if (err < 0) | |
1462 | goto out; | |
1463 | namelen = err; | |
1464 | } else { | |
1465 | sunaddr = NULL; | |
1466 | err = -ENOTCONN; | |
1467 | other = unix_peer_get(sk); | |
1468 | if (!other) | |
1469 | goto out; | |
1470 | } | |
1471 | ||
f64f9e71 JP |
1472 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
1473 | && (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1474 | goto out; |
1475 | ||
1476 | err = -EMSGSIZE; | |
1477 | if (len > sk->sk_sndbuf - 32) | |
1478 | goto out; | |
1479 | ||
eb6a2481 ED |
1480 | if (len > SKB_MAX_ALLOC) |
1481 | data_len = min_t(size_t, | |
1482 | len - SKB_MAX_ALLOC, | |
1483 | MAX_SKB_FRAGS * PAGE_SIZE); | |
1484 | ||
1485 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
1486 | msg->msg_flags & MSG_DONTWAIT, &err); | |
e27dfcea | 1487 | if (skb == NULL) |
1da177e4 LT |
1488 | goto out; |
1489 | ||
f78a5fda | 1490 | err = unix_scm_to_skb(siocb->scm, skb, true); |
25888e30 | 1491 | if (err < 0) |
7361c36c | 1492 | goto out_free; |
25888e30 | 1493 | max_level = err + 1; |
dc49c1f9 | 1494 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1495 | |
eb6a2481 ED |
1496 | skb_put(skb, len - data_len); |
1497 | skb->data_len = data_len; | |
1498 | skb->len = len; | |
1499 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); | |
1da177e4 LT |
1500 | if (err) |
1501 | goto out_free; | |
1502 | ||
1503 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1504 | ||
1505 | restart: | |
1506 | if (!other) { | |
1507 | err = -ECONNRESET; | |
1508 | if (sunaddr == NULL) | |
1509 | goto out_free; | |
1510 | ||
097e66c5 | 1511 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1da177e4 | 1512 | hash, &err); |
e27dfcea | 1513 | if (other == NULL) |
1da177e4 LT |
1514 | goto out_free; |
1515 | } | |
1516 | ||
d6ae3bae AC |
1517 | if (sk_filter(other, skb) < 0) { |
1518 | /* Toss the packet but do not return any error to the sender */ | |
1519 | err = len; | |
1520 | goto out_free; | |
1521 | } | |
1522 | ||
1c92b4e5 | 1523 | unix_state_lock(other); |
1da177e4 LT |
1524 | err = -EPERM; |
1525 | if (!unix_may_send(sk, other)) | |
1526 | goto out_unlock; | |
1527 | ||
1528 | if (sock_flag(other, SOCK_DEAD)) { | |
1529 | /* | |
1530 | * Check with 1003.1g - what should | |
1531 | * datagram error | |
1532 | */ | |
1c92b4e5 | 1533 | unix_state_unlock(other); |
1da177e4 LT |
1534 | sock_put(other); |
1535 | ||
1536 | err = 0; | |
1c92b4e5 | 1537 | unix_state_lock(sk); |
1da177e4 | 1538 | if (unix_peer(sk) == other) { |
e27dfcea | 1539 | unix_peer(sk) = NULL; |
1c92b4e5 | 1540 | unix_state_unlock(sk); |
1da177e4 LT |
1541 | |
1542 | unix_dgram_disconnected(sk, other); | |
1543 | sock_put(other); | |
1544 | err = -ECONNREFUSED; | |
1545 | } else { | |
1c92b4e5 | 1546 | unix_state_unlock(sk); |
1da177e4 LT |
1547 | } |
1548 | ||
1549 | other = NULL; | |
1550 | if (err) | |
1551 | goto out_free; | |
1552 | goto restart; | |
1553 | } | |
1554 | ||
1555 | err = -EPIPE; | |
1556 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1557 | goto out_unlock; | |
1558 | ||
1559 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1560 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1561 | if (err) | |
1562 | goto out_unlock; | |
1563 | } | |
1564 | ||
3c73419c | 1565 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1da177e4 LT |
1566 | if (!timeo) { |
1567 | err = -EAGAIN; | |
1568 | goto out_unlock; | |
1569 | } | |
1570 | ||
1571 | timeo = unix_wait_for_peer(other, timeo); | |
1572 | ||
1573 | err = sock_intr_errno(timeo); | |
1574 | if (signal_pending(current)) | |
1575 | goto out_free; | |
1576 | ||
1577 | goto restart; | |
1578 | } | |
1579 | ||
3f66116e AC |
1580 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
1581 | __net_timestamp(skb); | |
16e57262 | 1582 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1583 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1584 | if (max_level > unix_sk(other)->recursion_level) |
1585 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1586 | unix_state_unlock(other); |
1da177e4 LT |
1587 | other->sk_data_ready(other, len); |
1588 | sock_put(other); | |
f78a5fda | 1589 | scm_destroy(siocb->scm); |
1da177e4 LT |
1590 | return len; |
1591 | ||
1592 | out_unlock: | |
1c92b4e5 | 1593 | unix_state_unlock(other); |
1da177e4 LT |
1594 | out_free: |
1595 | kfree_skb(skb); | |
1596 | out: | |
1597 | if (other) | |
1598 | sock_put(other); | |
f78a5fda | 1599 | scm_destroy(siocb->scm); |
1da177e4 LT |
1600 | return err; |
1601 | } | |
1602 | ||
ac7bfa62 | 1603 | |
1da177e4 LT |
1604 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1605 | struct msghdr *msg, size_t len) | |
1606 | { | |
1607 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1608 | struct sock *sk = sock->sk; | |
1609 | struct sock *other = NULL; | |
6eba6a37 | 1610 | int err, size; |
f78a5fda | 1611 | struct sk_buff *skb; |
e27dfcea | 1612 | int sent = 0; |
1da177e4 | 1613 | struct scm_cookie tmp_scm; |
8ba69ba6 | 1614 | bool fds_sent = false; |
25888e30 | 1615 | int max_level; |
1da177e4 LT |
1616 | |
1617 | if (NULL == siocb->scm) | |
1618 | siocb->scm = &tmp_scm; | |
5f23b734 | 1619 | wait_for_unix_gc(); |
1da177e4 LT |
1620 | err = scm_send(sock, msg, siocb->scm); |
1621 | if (err < 0) | |
1622 | return err; | |
1623 | ||
1624 | err = -EOPNOTSUPP; | |
1625 | if (msg->msg_flags&MSG_OOB) | |
1626 | goto out_err; | |
1627 | ||
1628 | if (msg->msg_namelen) { | |
1629 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1630 | goto out_err; | |
1631 | } else { | |
1da177e4 | 1632 | err = -ENOTCONN; |
830a1e5c | 1633 | other = unix_peer(sk); |
1da177e4 LT |
1634 | if (!other) |
1635 | goto out_err; | |
1636 | } | |
1637 | ||
1638 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1639 | goto pipe_err; | |
1640 | ||
6eba6a37 | 1641 | while (sent < len) { |
1da177e4 | 1642 | /* |
e9df7d7f BL |
1643 | * Optimisation for the fact that under 0.01% of X |
1644 | * messages typically need breaking up. | |
1da177e4 LT |
1645 | */ |
1646 | ||
e9df7d7f | 1647 | size = len-sent; |
1da177e4 LT |
1648 | |
1649 | /* Keep two messages in the pipe so it schedules better */ | |
e9df7d7f BL |
1650 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
1651 | size = (sk->sk_sndbuf >> 1) - 64; | |
1da177e4 LT |
1652 | |
1653 | if (size > SKB_MAX_ALLOC) | |
1654 | size = SKB_MAX_ALLOC; | |
ac7bfa62 | 1655 | |
1da177e4 LT |
1656 | /* |
1657 | * Grab a buffer | |
1658 | */ | |
ac7bfa62 | 1659 | |
6eba6a37 ED |
1660 | skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, |
1661 | &err); | |
1da177e4 | 1662 | |
e27dfcea | 1663 | if (skb == NULL) |
1da177e4 LT |
1664 | goto out_err; |
1665 | ||
1666 | /* | |
1667 | * If you pass two values to the sock_alloc_send_skb | |
1668 | * it tries to grab the large buffer with GFP_NOFS | |
1669 | * (which can fail easily), and if it fails grab the | |
1670 | * fallback size buffer which is under a page and will | |
1671 | * succeed. [Alan] | |
1672 | */ | |
1673 | size = min_t(int, size, skb_tailroom(skb)); | |
1674 | ||
7361c36c | 1675 | |
f78a5fda DM |
1676 | /* Only send the fds in the first buffer */ |
1677 | err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); | |
25888e30 | 1678 | if (err < 0) { |
7361c36c | 1679 | kfree_skb(skb); |
f78a5fda | 1680 | goto out_err; |
6209344f | 1681 | } |
25888e30 | 1682 | max_level = err + 1; |
7361c36c | 1683 | fds_sent = true; |
1da177e4 | 1684 | |
6eba6a37 ED |
1685 | err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
1686 | if (err) { | |
1da177e4 | 1687 | kfree_skb(skb); |
f78a5fda | 1688 | goto out_err; |
1da177e4 LT |
1689 | } |
1690 | ||
1c92b4e5 | 1691 | unix_state_lock(other); |
1da177e4 LT |
1692 | |
1693 | if (sock_flag(other, SOCK_DEAD) || | |
1694 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1695 | goto pipe_err_free; | |
1696 | ||
16e57262 | 1697 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1698 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1699 | if (max_level > unix_sk(other)->recursion_level) |
1700 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1701 | unix_state_unlock(other); |
1da177e4 | 1702 | other->sk_data_ready(other, size); |
e27dfcea | 1703 | sent += size; |
1da177e4 | 1704 | } |
1da177e4 | 1705 | |
f78a5fda | 1706 | scm_destroy(siocb->scm); |
1da177e4 LT |
1707 | siocb->scm = NULL; |
1708 | ||
1709 | return sent; | |
1710 | ||
1711 | pipe_err_free: | |
1c92b4e5 | 1712 | unix_state_unlock(other); |
1da177e4 LT |
1713 | kfree_skb(skb); |
1714 | pipe_err: | |
6eba6a37 ED |
1715 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1716 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
1717 | err = -EPIPE; |
1718 | out_err: | |
f78a5fda | 1719 | scm_destroy(siocb->scm); |
1da177e4 LT |
1720 | siocb->scm = NULL; |
1721 | return sent ? : err; | |
1722 | } | |
1723 | ||
1724 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1725 | struct msghdr *msg, size_t len) | |
1726 | { | |
1727 | int err; | |
1728 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1729 | |
1da177e4 LT |
1730 | err = sock_error(sk); |
1731 | if (err) | |
1732 | return err; | |
1733 | ||
1734 | if (sk->sk_state != TCP_ESTABLISHED) | |
1735 | return -ENOTCONN; | |
1736 | ||
1737 | if (msg->msg_namelen) | |
1738 | msg->msg_namelen = 0; | |
1739 | ||
1740 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1741 | } | |
ac7bfa62 | 1742 | |
a05d2ad1 EB |
1743 | static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
1744 | struct msghdr *msg, size_t size, | |
1745 | int flags) | |
1746 | { | |
1747 | struct sock *sk = sock->sk; | |
1748 | ||
1749 | if (sk->sk_state != TCP_ESTABLISHED) | |
1750 | return -ENOTCONN; | |
1751 | ||
1752 | return unix_dgram_recvmsg(iocb, sock, msg, size, flags); | |
1753 | } | |
1754 | ||
1da177e4 LT |
1755 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1756 | { | |
1757 | struct unix_sock *u = unix_sk(sk); | |
1758 | ||
1759 | msg->msg_namelen = 0; | |
1760 | if (u->addr) { | |
1761 | msg->msg_namelen = u->addr->len; | |
1762 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1763 | } | |
1764 | } | |
1765 | ||
1766 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1767 | struct msghdr *msg, size_t size, | |
1768 | int flags) | |
1769 | { | |
1770 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1771 | struct scm_cookie tmp_scm; | |
1772 | struct sock *sk = sock->sk; | |
1773 | struct unix_sock *u = unix_sk(sk); | |
1774 | int noblock = flags & MSG_DONTWAIT; | |
1775 | struct sk_buff *skb; | |
1776 | int err; | |
f55bb7f9 | 1777 | int peeked, skip; |
1da177e4 LT |
1778 | |
1779 | err = -EOPNOTSUPP; | |
1780 | if (flags&MSG_OOB) | |
1781 | goto out; | |
1782 | ||
1783 | msg->msg_namelen = 0; | |
1784 | ||
b3ca9b02 RW |
1785 | err = mutex_lock_interruptible(&u->readlock); |
1786 | if (err) { | |
1787 | err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); | |
1788 | goto out; | |
1789 | } | |
1da177e4 | 1790 | |
f55bb7f9 PE |
1791 | skip = sk_peek_offset(sk, flags); |
1792 | ||
1793 | skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); | |
0a112258 FZ |
1794 | if (!skb) { |
1795 | unix_state_lock(sk); | |
1796 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
1797 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
1798 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1799 | err = 0; | |
1800 | unix_state_unlock(sk); | |
1da177e4 | 1801 | goto out_unlock; |
0a112258 | 1802 | } |
1da177e4 | 1803 | |
67426b75 ED |
1804 | wake_up_interruptible_sync_poll(&u->peer_wait, |
1805 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
1da177e4 LT |
1806 | |
1807 | if (msg->msg_name) | |
1808 | unix_copy_addr(msg, skb->sk); | |
1809 | ||
f55bb7f9 PE |
1810 | if (size > skb->len - skip) |
1811 | size = skb->len - skip; | |
1812 | else if (size < skb->len - skip) | |
1da177e4 LT |
1813 | msg->msg_flags |= MSG_TRUNC; |
1814 | ||
f55bb7f9 | 1815 | err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size); |
1da177e4 LT |
1816 | if (err) |
1817 | goto out_free; | |
1818 | ||
3f66116e AC |
1819 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
1820 | __sock_recv_timestamp(msg, sk, skb); | |
1821 | ||
1da177e4 LT |
1822 | if (!siocb->scm) { |
1823 | siocb->scm = &tmp_scm; | |
1824 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1825 | } | |
f78a5fda | 1826 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
877ce7c1 | 1827 | unix_set_secdata(siocb->scm, skb); |
1da177e4 | 1828 | |
6eba6a37 | 1829 | if (!(flags & MSG_PEEK)) { |
1da177e4 LT |
1830 | if (UNIXCB(skb).fp) |
1831 | unix_detach_fds(siocb->scm, skb); | |
f55bb7f9 PE |
1832 | |
1833 | sk_peek_offset_bwd(sk, skb->len); | |
6eba6a37 | 1834 | } else { |
1da177e4 LT |
1835 | /* It is questionable: on PEEK we could: |
1836 | - do not return fds - good, but too simple 8) | |
1837 | - return fds, and do not return them on read (old strategy, | |
1838 | apparently wrong) | |
1839 | - clone fds (I chose it for now, it is the most universal | |
1840 | solution) | |
ac7bfa62 YH |
1841 | |
1842 | POSIX 1003.1g does not actually define this clearly | |
1843 | at all. POSIX 1003.1g doesn't define a lot of things | |
1844 | clearly however! | |
1845 | ||
1da177e4 | 1846 | */ |
f55bb7f9 PE |
1847 | |
1848 | sk_peek_offset_fwd(sk, size); | |
1849 | ||
1da177e4 LT |
1850 | if (UNIXCB(skb).fp) |
1851 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1852 | } | |
9f6f9af7 | 1853 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
1da177e4 LT |
1854 | |
1855 | scm_recv(sock, msg, siocb->scm, flags); | |
1856 | ||
1857 | out_free: | |
6eba6a37 | 1858 | skb_free_datagram(sk, skb); |
1da177e4 | 1859 | out_unlock: |
57b47a53 | 1860 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1861 | out: |
1862 | return err; | |
1863 | } | |
1864 | ||
1865 | /* | |
1866 | * Sleep until data has arrive. But check for races.. | |
1867 | */ | |
ac7bfa62 | 1868 | |
6eba6a37 | 1869 | static long unix_stream_data_wait(struct sock *sk, long timeo) |
1da177e4 LT |
1870 | { |
1871 | DEFINE_WAIT(wait); | |
1872 | ||
1c92b4e5 | 1873 | unix_state_lock(sk); |
1da177e4 LT |
1874 | |
1875 | for (;;) { | |
aa395145 | 1876 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
1da177e4 | 1877 | |
b03efcfb | 1878 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
1da177e4 LT |
1879 | sk->sk_err || |
1880 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1881 | signal_pending(current) || | |
1882 | !timeo) | |
1883 | break; | |
1884 | ||
1885 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1886 | unix_state_unlock(sk); |
1da177e4 | 1887 | timeo = schedule_timeout(timeo); |
1c92b4e5 | 1888 | unix_state_lock(sk); |
1da177e4 LT |
1889 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1890 | } | |
1891 | ||
aa395145 | 1892 | finish_wait(sk_sleep(sk), &wait); |
1c92b4e5 | 1893 | unix_state_unlock(sk); |
1da177e4 LT |
1894 | return timeo; |
1895 | } | |
1896 | ||
1897 | ||
1898 | ||
1899 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1900 | struct msghdr *msg, size_t size, | |
1901 | int flags) | |
1902 | { | |
1903 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1904 | struct scm_cookie tmp_scm; | |
1905 | struct sock *sk = sock->sk; | |
1906 | struct unix_sock *u = unix_sk(sk); | |
e27dfcea | 1907 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1908 | int copied = 0; |
1909 | int check_creds = 0; | |
1910 | int target; | |
1911 | int err = 0; | |
1912 | long timeo; | |
fc0d7536 | 1913 | int skip; |
1da177e4 LT |
1914 | |
1915 | err = -EINVAL; | |
1916 | if (sk->sk_state != TCP_ESTABLISHED) | |
1917 | goto out; | |
1918 | ||
1919 | err = -EOPNOTSUPP; | |
1920 | if (flags&MSG_OOB) | |
1921 | goto out; | |
1922 | ||
1923 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1924 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1925 | ||
1926 | msg->msg_namelen = 0; | |
1927 | ||
1928 | /* Lock the socket to prevent queue disordering | |
1929 | * while sleeps in memcpy_tomsg | |
1930 | */ | |
1931 | ||
1932 | if (!siocb->scm) { | |
1933 | siocb->scm = &tmp_scm; | |
1934 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1935 | } | |
1936 | ||
b3ca9b02 RW |
1937 | err = mutex_lock_interruptible(&u->readlock); |
1938 | if (err) { | |
1939 | err = sock_intr_errno(timeo); | |
1940 | goto out; | |
1941 | } | |
1da177e4 | 1942 | |
fc0d7536 PE |
1943 | skip = sk_peek_offset(sk, flags); |
1944 | ||
6eba6a37 | 1945 | do { |
1da177e4 LT |
1946 | int chunk; |
1947 | struct sk_buff *skb; | |
1948 | ||
3c0d2f37 | 1949 | unix_state_lock(sk); |
6f01fd6e | 1950 | skb = skb_peek(&sk->sk_receive_queue); |
fc0d7536 | 1951 | again: |
6eba6a37 | 1952 | if (skb == NULL) { |
25888e30 | 1953 | unix_sk(sk)->recursion_level = 0; |
1da177e4 | 1954 | if (copied >= target) |
3c0d2f37 | 1955 | goto unlock; |
1da177e4 LT |
1956 | |
1957 | /* | |
1958 | * POSIX 1003.1g mandates this order. | |
1959 | */ | |
ac7bfa62 | 1960 | |
6eba6a37 ED |
1961 | err = sock_error(sk); |
1962 | if (err) | |
3c0d2f37 | 1963 | goto unlock; |
1da177e4 | 1964 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1965 | goto unlock; |
1966 | ||
1967 | unix_state_unlock(sk); | |
1da177e4 LT |
1968 | err = -EAGAIN; |
1969 | if (!timeo) | |
1970 | break; | |
57b47a53 | 1971 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1972 | |
1973 | timeo = unix_stream_data_wait(sk, timeo); | |
1974 | ||
b3ca9b02 RW |
1975 | if (signal_pending(current) |
1976 | || mutex_lock_interruptible(&u->readlock)) { | |
1da177e4 LT |
1977 | err = sock_intr_errno(timeo); |
1978 | goto out; | |
1979 | } | |
b3ca9b02 | 1980 | |
1da177e4 | 1981 | continue; |
3c0d2f37 MS |
1982 | unlock: |
1983 | unix_state_unlock(sk); | |
1984 | break; | |
1da177e4 | 1985 | } |
fc0d7536 PE |
1986 | |
1987 | if (skip >= skb->len) { | |
1988 | skip -= skb->len; | |
1989 | skb = skb_peek_next(skb, &sk->sk_receive_queue); | |
1990 | goto again; | |
1991 | } | |
1992 | ||
3c0d2f37 | 1993 | unix_state_unlock(sk); |
1da177e4 LT |
1994 | |
1995 | if (check_creds) { | |
1996 | /* Never glue messages from different writers */ | |
7361c36c | 1997 | if ((UNIXCB(skb).pid != siocb->scm->pid) || |
6f01fd6e | 1998 | (UNIXCB(skb).cred != siocb->scm->cred)) |
1da177e4 | 1999 | break; |
1da177e4 LT |
2000 | } else { |
2001 | /* Copy credentials */ | |
f78a5fda | 2002 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
1da177e4 LT |
2003 | check_creds = 1; |
2004 | } | |
2005 | ||
2006 | /* Copy address just once */ | |
6eba6a37 | 2007 | if (sunaddr) { |
1da177e4 LT |
2008 | unix_copy_addr(msg, skb->sk); |
2009 | sunaddr = NULL; | |
2010 | } | |
2011 | ||
fc0d7536 PE |
2012 | chunk = min_t(unsigned int, skb->len - skip, size); |
2013 | if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) { | |
1da177e4 LT |
2014 | if (copied == 0) |
2015 | copied = -EFAULT; | |
2016 | break; | |
2017 | } | |
2018 | copied += chunk; | |
2019 | size -= chunk; | |
2020 | ||
2021 | /* Mark read part of skb as used */ | |
6eba6a37 | 2022 | if (!(flags & MSG_PEEK)) { |
1da177e4 LT |
2023 | skb_pull(skb, chunk); |
2024 | ||
fc0d7536 PE |
2025 | sk_peek_offset_bwd(sk, chunk); |
2026 | ||
1da177e4 LT |
2027 | if (UNIXCB(skb).fp) |
2028 | unix_detach_fds(siocb->scm, skb); | |
2029 | ||
6f01fd6e | 2030 | if (skb->len) |
1da177e4 | 2031 | break; |
1da177e4 | 2032 | |
6f01fd6e | 2033 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2034 | consume_skb(skb); |
1da177e4 LT |
2035 | |
2036 | if (siocb->scm->fp) | |
2037 | break; | |
6eba6a37 | 2038 | } else { |
1da177e4 LT |
2039 | /* It is questionable, see note in unix_dgram_recvmsg. |
2040 | */ | |
2041 | if (UNIXCB(skb).fp) | |
2042 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
2043 | ||
fc0d7536 PE |
2044 | sk_peek_offset_fwd(sk, chunk); |
2045 | ||
1da177e4 LT |
2046 | break; |
2047 | } | |
2048 | } while (size); | |
2049 | ||
57b47a53 | 2050 | mutex_unlock(&u->readlock); |
1da177e4 LT |
2051 | scm_recv(sock, msg, siocb->scm, flags); |
2052 | out: | |
2053 | return copied ? : err; | |
2054 | } | |
2055 | ||
2056 | static int unix_shutdown(struct socket *sock, int mode) | |
2057 | { | |
2058 | struct sock *sk = sock->sk; | |
2059 | struct sock *other; | |
2060 | ||
2061 | mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); | |
2062 | ||
7180a031 AC |
2063 | if (!mode) |
2064 | return 0; | |
2065 | ||
2066 | unix_state_lock(sk); | |
2067 | sk->sk_shutdown |= mode; | |
2068 | other = unix_peer(sk); | |
2069 | if (other) | |
2070 | sock_hold(other); | |
2071 | unix_state_unlock(sk); | |
2072 | sk->sk_state_change(sk); | |
2073 | ||
2074 | if (other && | |
2075 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2076 | ||
2077 | int peer_mode = 0; | |
2078 | ||
2079 | if (mode&RCV_SHUTDOWN) | |
2080 | peer_mode |= SEND_SHUTDOWN; | |
2081 | if (mode&SEND_SHUTDOWN) | |
2082 | peer_mode |= RCV_SHUTDOWN; | |
2083 | unix_state_lock(other); | |
2084 | other->sk_shutdown |= peer_mode; | |
2085 | unix_state_unlock(other); | |
2086 | other->sk_state_change(other); | |
2087 | if (peer_mode == SHUTDOWN_MASK) | |
2088 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2089 | else if (peer_mode & RCV_SHUTDOWN) | |
2090 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
1da177e4 | 2091 | } |
7180a031 AC |
2092 | if (other) |
2093 | sock_put(other); | |
2094 | ||
1da177e4 LT |
2095 | return 0; |
2096 | } | |
2097 | ||
885ee74d PE |
2098 | long unix_inq_len(struct sock *sk) |
2099 | { | |
2100 | struct sk_buff *skb; | |
2101 | long amount = 0; | |
2102 | ||
2103 | if (sk->sk_state == TCP_LISTEN) | |
2104 | return -EINVAL; | |
2105 | ||
2106 | spin_lock(&sk->sk_receive_queue.lock); | |
2107 | if (sk->sk_type == SOCK_STREAM || | |
2108 | sk->sk_type == SOCK_SEQPACKET) { | |
2109 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
2110 | amount += skb->len; | |
2111 | } else { | |
2112 | skb = skb_peek(&sk->sk_receive_queue); | |
2113 | if (skb) | |
2114 | amount = skb->len; | |
2115 | } | |
2116 | spin_unlock(&sk->sk_receive_queue.lock); | |
2117 | ||
2118 | return amount; | |
2119 | } | |
2120 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2121 | ||
2122 | long unix_outq_len(struct sock *sk) | |
2123 | { | |
2124 | return sk_wmem_alloc_get(sk); | |
2125 | } | |
2126 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2127 | ||
1da177e4 LT |
2128 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
2129 | { | |
2130 | struct sock *sk = sock->sk; | |
e27dfcea | 2131 | long amount = 0; |
1da177e4 LT |
2132 | int err; |
2133 | ||
6eba6a37 ED |
2134 | switch (cmd) { |
2135 | case SIOCOUTQ: | |
885ee74d | 2136 | amount = unix_outq_len(sk); |
6eba6a37 ED |
2137 | err = put_user(amount, (int __user *)arg); |
2138 | break; | |
2139 | case SIOCINQ: | |
885ee74d PE |
2140 | amount = unix_inq_len(sk); |
2141 | if (amount < 0) | |
2142 | err = amount; | |
2143 | else | |
1da177e4 | 2144 | err = put_user(amount, (int __user *)arg); |
885ee74d | 2145 | break; |
6eba6a37 ED |
2146 | default: |
2147 | err = -ENOIOCTLCMD; | |
2148 | break; | |
1da177e4 LT |
2149 | } |
2150 | return err; | |
2151 | } | |
2152 | ||
6eba6a37 | 2153 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
2154 | { |
2155 | struct sock *sk = sock->sk; | |
2156 | unsigned int mask; | |
2157 | ||
aa395145 | 2158 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
2159 | mask = 0; |
2160 | ||
2161 | /* exceptional events? */ | |
2162 | if (sk->sk_err) | |
2163 | mask |= POLLERR; | |
2164 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2165 | mask |= POLLHUP; | |
f348d70a | 2166 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 2167 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
2168 | |
2169 | /* readable? */ | |
db40980f | 2170 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
2171 | mask |= POLLIN | POLLRDNORM; |
2172 | ||
2173 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
2174 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2175 | sk->sk_state == TCP_CLOSE) | |
1da177e4 LT |
2176 | mask |= POLLHUP; |
2177 | ||
2178 | /* | |
2179 | * we set writable also when the other side has shut down the | |
2180 | * connection. This prevents stuck sockets. | |
2181 | */ | |
2182 | if (unix_writable(sk)) | |
2183 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2184 | ||
2185 | return mask; | |
2186 | } | |
2187 | ||
ec0d215f RW |
2188 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2189 | poll_table *wait) | |
3c73419c | 2190 | { |
ec0d215f RW |
2191 | struct sock *sk = sock->sk, *other; |
2192 | unsigned int mask, writable; | |
3c73419c | 2193 | |
aa395145 | 2194 | sock_poll_wait(file, sk_sleep(sk), wait); |
3c73419c RW |
2195 | mask = 0; |
2196 | ||
2197 | /* exceptional events? */ | |
2198 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
2199 | mask |= POLLERR; | |
2200 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
5456f09a | 2201 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
3c73419c RW |
2202 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2203 | mask |= POLLHUP; | |
2204 | ||
2205 | /* readable? */ | |
5456f09a | 2206 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
3c73419c RW |
2207 | mask |= POLLIN | POLLRDNORM; |
2208 | ||
2209 | /* Connection-based need to check for termination and startup */ | |
2210 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2211 | if (sk->sk_state == TCP_CLOSE) | |
2212 | mask |= POLLHUP; | |
2213 | /* connection hasn't started yet? */ | |
2214 | if (sk->sk_state == TCP_SYN_SENT) | |
2215 | return mask; | |
2216 | } | |
2217 | ||
973a34aa | 2218 | /* No write status requested, avoid expensive OUT tests. */ |
626cf236 | 2219 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
973a34aa ED |
2220 | return mask; |
2221 | ||
ec0d215f | 2222 | writable = unix_writable(sk); |
5456f09a ED |
2223 | other = unix_peer_get(sk); |
2224 | if (other) { | |
2225 | if (unix_peer(other) != sk) { | |
2226 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); | |
2227 | if (unix_recvq_full(other)) | |
2228 | writable = 0; | |
ec0d215f | 2229 | } |
5456f09a | 2230 | sock_put(other); |
ec0d215f RW |
2231 | } |
2232 | ||
2233 | if (writable) | |
3c73419c RW |
2234 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2235 | else | |
2236 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
2237 | ||
3c73419c RW |
2238 | return mask; |
2239 | } | |
1da177e4 LT |
2240 | |
2241 | #ifdef CONFIG_PROC_FS | |
a53eb3fe PE |
2242 | static struct sock *first_unix_socket(int *i) |
2243 | { | |
2244 | for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { | |
2245 | if (!hlist_empty(&unix_socket_table[*i])) | |
2246 | return __sk_head(&unix_socket_table[*i]); | |
2247 | } | |
2248 | return NULL; | |
2249 | } | |
2250 | ||
2251 | static struct sock *next_unix_socket(int *i, struct sock *s) | |
2252 | { | |
2253 | struct sock *next = sk_next(s); | |
2254 | /* More in this chain? */ | |
2255 | if (next) | |
2256 | return next; | |
2257 | /* Look for next non-empty chain. */ | |
2258 | for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { | |
2259 | if (!hlist_empty(&unix_socket_table[*i])) | |
2260 | return __sk_head(&unix_socket_table[*i]); | |
2261 | } | |
2262 | return NULL; | |
2263 | } | |
2264 | ||
097e66c5 | 2265 | struct unix_iter_state { |
e372c414 | 2266 | struct seq_net_private p; |
097e66c5 DL |
2267 | int i; |
2268 | }; | |
e27dfcea | 2269 | |
1218854a | 2270 | static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) |
1da177e4 | 2271 | { |
1218854a | 2272 | struct unix_iter_state *iter = seq->private; |
1da177e4 LT |
2273 | loff_t off = 0; |
2274 | struct sock *s; | |
2275 | ||
097e66c5 | 2276 | for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { |
1218854a | 2277 | if (sock_net(s) != seq_file_net(seq)) |
097e66c5 | 2278 | continue; |
ac7bfa62 | 2279 | if (off == pos) |
1da177e4 LT |
2280 | return s; |
2281 | ++off; | |
2282 | } | |
2283 | return NULL; | |
2284 | } | |
2285 | ||
1da177e4 | 2286 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
9a429c49 | 2287 | __acquires(unix_table_lock) |
1da177e4 | 2288 | { |
fbe9cc4a | 2289 | spin_lock(&unix_table_lock); |
b9f3124f | 2290 | return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; |
1da177e4 LT |
2291 | } |
2292 | ||
2293 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2294 | { | |
097e66c5 DL |
2295 | struct unix_iter_state *iter = seq->private; |
2296 | struct sock *sk = v; | |
1da177e4 LT |
2297 | ++*pos; |
2298 | ||
b9f3124f | 2299 | if (v == SEQ_START_TOKEN) |
097e66c5 DL |
2300 | sk = first_unix_socket(&iter->i); |
2301 | else | |
2302 | sk = next_unix_socket(&iter->i, sk); | |
1218854a | 2303 | while (sk && (sock_net(sk) != seq_file_net(seq))) |
097e66c5 DL |
2304 | sk = next_unix_socket(&iter->i, sk); |
2305 | return sk; | |
1da177e4 LT |
2306 | } |
2307 | ||
2308 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2309 | __releases(unix_table_lock) |
1da177e4 | 2310 | { |
fbe9cc4a | 2311 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2312 | } |
2313 | ||
2314 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2315 | { | |
ac7bfa62 | 2316 | |
b9f3124f | 2317 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
2318 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2319 | "Inode Path\n"); | |
2320 | else { | |
2321 | struct sock *s = v; | |
2322 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2323 | unix_state_lock(s); |
1da177e4 | 2324 | |
71338aa7 | 2325 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 LT |
2326 | s, |
2327 | atomic_read(&s->sk_refcnt), | |
2328 | 0, | |
2329 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2330 | s->sk_type, | |
2331 | s->sk_socket ? | |
2332 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2333 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2334 | sock_i_ino(s)); | |
2335 | ||
2336 | if (u->addr) { | |
2337 | int i, len; | |
2338 | seq_putc(seq, ' '); | |
2339 | ||
2340 | i = 0; | |
2341 | len = u->addr->len - sizeof(short); | |
2342 | if (!UNIX_ABSTRACT(s)) | |
2343 | len--; | |
2344 | else { | |
2345 | seq_putc(seq, '@'); | |
2346 | i++; | |
2347 | } | |
2348 | for ( ; i < len; i++) | |
2349 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2350 | } | |
1c92b4e5 | 2351 | unix_state_unlock(s); |
1da177e4 LT |
2352 | seq_putc(seq, '\n'); |
2353 | } | |
2354 | ||
2355 | return 0; | |
2356 | } | |
2357 | ||
56b3d975 | 2358 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2359 | .start = unix_seq_start, |
2360 | .next = unix_seq_next, | |
2361 | .stop = unix_seq_stop, | |
2362 | .show = unix_seq_show, | |
2363 | }; | |
2364 | ||
1da177e4 LT |
2365 | static int unix_seq_open(struct inode *inode, struct file *file) |
2366 | { | |
e372c414 DL |
2367 | return seq_open_net(inode, file, &unix_seq_ops, |
2368 | sizeof(struct unix_iter_state)); | |
1da177e4 LT |
2369 | } |
2370 | ||
da7071d7 | 2371 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2372 | .owner = THIS_MODULE, |
2373 | .open = unix_seq_open, | |
2374 | .read = seq_read, | |
2375 | .llseek = seq_lseek, | |
e372c414 | 2376 | .release = seq_release_net, |
1da177e4 LT |
2377 | }; |
2378 | ||
2379 | #endif | |
2380 | ||
ec1b4cf7 | 2381 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
2382 | .family = PF_UNIX, |
2383 | .create = unix_create, | |
2384 | .owner = THIS_MODULE, | |
2385 | }; | |
2386 | ||
097e66c5 | 2387 | |
2c8c1e72 | 2388 | static int __net_init unix_net_init(struct net *net) |
097e66c5 DL |
2389 | { |
2390 | int error = -ENOMEM; | |
2391 | ||
a0a53c8b | 2392 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
2393 | if (unix_sysctl_register(net)) |
2394 | goto out; | |
d392e497 | 2395 | |
097e66c5 | 2396 | #ifdef CONFIG_PROC_FS |
1597fbc0 PE |
2397 | if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { |
2398 | unix_sysctl_unregister(net); | |
097e66c5 | 2399 | goto out; |
1597fbc0 | 2400 | } |
097e66c5 DL |
2401 | #endif |
2402 | error = 0; | |
2403 | out: | |
48dcc33e | 2404 | return error; |
097e66c5 DL |
2405 | } |
2406 | ||
2c8c1e72 | 2407 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 2408 | { |
1597fbc0 | 2409 | unix_sysctl_unregister(net); |
097e66c5 DL |
2410 | proc_net_remove(net, "unix"); |
2411 | } | |
2412 | ||
2413 | static struct pernet_operations unix_net_ops = { | |
2414 | .init = unix_net_init, | |
2415 | .exit = unix_net_exit, | |
2416 | }; | |
2417 | ||
1da177e4 LT |
2418 | static int __init af_unix_init(void) |
2419 | { | |
2420 | int rc = -1; | |
2421 | struct sk_buff *dummy_skb; | |
2422 | ||
ef047f5e | 2423 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 LT |
2424 | |
2425 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 YH |
2426 | if (rc != 0) { |
2427 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
0dc47877 | 2428 | __func__); |
1da177e4 LT |
2429 | goto out; |
2430 | } | |
2431 | ||
2432 | sock_register(&unix_family_ops); | |
097e66c5 | 2433 | register_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2434 | out: |
2435 | return rc; | |
2436 | } | |
2437 | ||
2438 | static void __exit af_unix_exit(void) | |
2439 | { | |
2440 | sock_unregister(PF_UNIX); | |
1da177e4 | 2441 | proto_unregister(&unix_proto); |
097e66c5 | 2442 | unregister_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2443 | } |
2444 | ||
3d366960 DW |
2445 | /* Earlier than device_initcall() so that other drivers invoking |
2446 | request_module() don't end up in a loop when modprobe tries | |
2447 | to use a UNIX socket. But later than subsys_initcall() because | |
2448 | we depend on stuff initialised there */ | |
2449 | fs_initcall(af_unix_init); | |
1da177e4 LT |
2450 | module_exit(af_unix_exit); |
2451 | ||
2452 | MODULE_LICENSE("GPL"); | |
2453 | MODULE_ALIAS_NETPROTO(PF_UNIX); |