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1 | /* | |
2 | * NET4: Implementation of BSD Unix domain sockets. | |
3 | * | |
4 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * Fixes: | |
12 | * Linus Torvalds : Assorted bug cures. | |
13 | * Niibe Yutaka : async I/O support. | |
14 | * Carsten Paeth : PF_UNIX check, address fixes. | |
15 | * Alan Cox : Limit size of allocated blocks. | |
16 | * Alan Cox : Fixed the stupid socketpair bug. | |
17 | * Alan Cox : BSD compatibility fine tuning. | |
18 | * Alan Cox : Fixed a bug in connect when interrupted. | |
19 | * Alan Cox : Sorted out a proper draft version of | |
20 | * file descriptor passing hacked up from | |
21 | * Mike Shaver's work. | |
22 | * Marty Leisner : Fixes to fd passing | |
23 | * Nick Nevin : recvmsg bugfix. | |
24 | * Alan Cox : Started proper garbage collector | |
25 | * Heiko EiBfeldt : Missing verify_area check | |
26 | * Alan Cox : Started POSIXisms | |
27 | * Andreas Schwab : Replace inode by dentry for proper | |
28 | * reference counting | |
29 | * Kirk Petersen : Made this a module | |
30 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. | |
31 | * Lots of bug fixes. | |
32 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces | |
33 | * by above two patches. | |
34 | * Andrea Arcangeli : If possible we block in connect(2) | |
35 | * if the max backlog of the listen socket | |
36 | * is been reached. This won't break | |
37 | * old apps and it will avoid huge amount | |
38 | * of socks hashed (this for unix_gc() | |
39 | * performances reasons). | |
40 | * Security fix that limits the max | |
41 | * number of socks to 2*max_files and | |
42 | * the number of skb queueable in the | |
43 | * dgram receiver. | |
44 | * Artur Skawina : Hash function optimizations | |
45 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) | |
46 | * Malcolm Beattie : Set peercred for socketpair | |
47 | * Michal Ostrowski : Module initialization cleanup. | |
48 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, | |
49 | * the core infrastructure is doing that | |
50 | * for all net proto families now (2.5.69+) | |
51 | * | |
52 | * | |
53 | * Known differences from reference BSD that was tested: | |
54 | * | |
55 | * [TO FIX] | |
56 | * ECONNREFUSED is not returned from one end of a connected() socket to the | |
57 | * other the moment one end closes. | |
58 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark | |
59 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). | |
60 | * [NOT TO FIX] | |
61 | * accept() returns a path name even if the connecting socket has closed | |
62 | * in the meantime (BSD loses the path and gives up). | |
63 | * accept() returns 0 length path for an unbound connector. BSD returns 16 | |
64 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) | |
65 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. | |
66 | * BSD af_unix apparently has connect forgetting to block properly. | |
67 | * (need to check this with the POSIX spec in detail) | |
68 | * | |
69 | * Differences from 2.0.0-11-... (ANK) | |
70 | * Bug fixes and improvements. | |
71 | * - client shutdown killed server socket. | |
72 | * - removed all useless cli/sti pairs. | |
73 | * | |
74 | * Semantic changes/extensions. | |
75 | * - generic control message passing. | |
76 | * - SCM_CREDENTIALS control message. | |
77 | * - "Abstract" (not FS based) socket bindings. | |
78 | * Abstract names are sequences of bytes (not zero terminated) | |
79 | * started by 0, so that this name space does not intersect | |
80 | * with BSD names. | |
81 | */ | |
82 | ||
83 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
84 | ||
85 | #include <linux/module.h> | |
86 | #include <linux/kernel.h> | |
87 | #include <linux/signal.h> | |
88 | #include <linux/sched/signal.h> | |
89 | #include <linux/errno.h> | |
90 | #include <linux/string.h> | |
91 | #include <linux/stat.h> | |
92 | #include <linux/dcache.h> | |
93 | #include <linux/namei.h> | |
94 | #include <linux/socket.h> | |
95 | #include <linux/un.h> | |
96 | #include <linux/fcntl.h> | |
97 | #include <linux/termios.h> | |
98 | #include <linux/sockios.h> | |
99 | #include <linux/net.h> | |
100 | #include <linux/in.h> | |
101 | #include <linux/fs.h> | |
102 | #include <linux/slab.h> | |
103 | #include <linux/uaccess.h> | |
104 | #include <linux/skbuff.h> | |
105 | #include <linux/netdevice.h> | |
106 | #include <net/net_namespace.h> | |
107 | #include <net/sock.h> | |
108 | #include <net/tcp_states.h> | |
109 | #include <net/af_unix.h> | |
110 | #include <linux/proc_fs.h> | |
111 | #include <linux/seq_file.h> | |
112 | #include <net/scm.h> | |
113 | #include <linux/init.h> | |
114 | #include <linux/poll.h> | |
115 | #include <linux/rtnetlink.h> | |
116 | #include <linux/mount.h> | |
117 | #include <net/checksum.h> | |
118 | #include <linux/security.h> | |
119 | #include <linux/freezer.h> | |
120 | #include <linux/file.h> | |
121 | ||
122 | struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; | |
123 | EXPORT_SYMBOL_GPL(unix_socket_table); | |
124 | DEFINE_SPINLOCK(unix_table_lock); | |
125 | EXPORT_SYMBOL_GPL(unix_table_lock); | |
126 | static atomic_long_t unix_nr_socks; | |
127 | ||
128 | ||
129 | static struct hlist_head *unix_sockets_unbound(void *addr) | |
130 | { | |
131 | unsigned long hash = (unsigned long)addr; | |
132 | ||
133 | hash ^= hash >> 16; | |
134 | hash ^= hash >> 8; | |
135 | hash %= UNIX_HASH_SIZE; | |
136 | return &unix_socket_table[UNIX_HASH_SIZE + hash]; | |
137 | } | |
138 | ||
139 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE) | |
140 | ||
141 | #ifdef CONFIG_SECURITY_NETWORK | |
142 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
143 | { | |
144 | UNIXCB(skb).secid = scm->secid; | |
145 | } | |
146 | ||
147 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
148 | { | |
149 | scm->secid = UNIXCB(skb).secid; | |
150 | } | |
151 | ||
152 | static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) | |
153 | { | |
154 | return (scm->secid == UNIXCB(skb).secid); | |
155 | } | |
156 | #else | |
157 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
158 | { } | |
159 | ||
160 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
161 | { } | |
162 | ||
163 | static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) | |
164 | { | |
165 | return true; | |
166 | } | |
167 | #endif /* CONFIG_SECURITY_NETWORK */ | |
168 | ||
169 | /* | |
170 | * SMP locking strategy: | |
171 | * hash table is protected with spinlock unix_table_lock | |
172 | * each socket state is protected by separate spin lock. | |
173 | */ | |
174 | ||
175 | static inline unsigned int unix_hash_fold(__wsum n) | |
176 | { | |
177 | unsigned int hash = (__force unsigned int)csum_fold(n); | |
178 | ||
179 | hash ^= hash>>8; | |
180 | return hash&(UNIX_HASH_SIZE-1); | |
181 | } | |
182 | ||
183 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
184 | ||
185 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
186 | { | |
187 | return unix_peer(osk) == sk; | |
188 | } | |
189 | ||
190 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
191 | { | |
192 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); | |
193 | } | |
194 | ||
195 | static inline int unix_recvq_full(struct sock const *sk) | |
196 | { | |
197 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
198 | } | |
199 | ||
200 | struct sock *unix_peer_get(struct sock *s) | |
201 | { | |
202 | struct sock *peer; | |
203 | ||
204 | unix_state_lock(s); | |
205 | peer = unix_peer(s); | |
206 | if (peer) | |
207 | sock_hold(peer); | |
208 | unix_state_unlock(s); | |
209 | return peer; | |
210 | } | |
211 | EXPORT_SYMBOL_GPL(unix_peer_get); | |
212 | ||
213 | static inline void unix_release_addr(struct unix_address *addr) | |
214 | { | |
215 | if (atomic_dec_and_test(&addr->refcnt)) | |
216 | kfree(addr); | |
217 | } | |
218 | ||
219 | /* | |
220 | * Check unix socket name: | |
221 | * - should be not zero length. | |
222 | * - if started by not zero, should be NULL terminated (FS object) | |
223 | * - if started by zero, it is abstract name. | |
224 | */ | |
225 | ||
226 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) | |
227 | { | |
228 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
229 | return -EINVAL; | |
230 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
231 | return -EINVAL; | |
232 | if (sunaddr->sun_path[0]) { | |
233 | /* | |
234 | * This may look like an off by one error but it is a bit more | |
235 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
236 | * sun_path[108] doesn't as such exist. However in kernel space | |
237 | * we are guaranteed that it is a valid memory location in our | |
238 | * kernel address buffer. | |
239 | */ | |
240 | ((char *)sunaddr)[len] = 0; | |
241 | len = strlen(sunaddr->sun_path)+1+sizeof(short); | |
242 | return len; | |
243 | } | |
244 | ||
245 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); | |
246 | return len; | |
247 | } | |
248 | ||
249 | static void __unix_remove_socket(struct sock *sk) | |
250 | { | |
251 | sk_del_node_init(sk); | |
252 | } | |
253 | ||
254 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
255 | { | |
256 | WARN_ON(!sk_unhashed(sk)); | |
257 | sk_add_node(sk, list); | |
258 | } | |
259 | ||
260 | static inline void unix_remove_socket(struct sock *sk) | |
261 | { | |
262 | spin_lock(&unix_table_lock); | |
263 | __unix_remove_socket(sk); | |
264 | spin_unlock(&unix_table_lock); | |
265 | } | |
266 | ||
267 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
268 | { | |
269 | spin_lock(&unix_table_lock); | |
270 | __unix_insert_socket(list, sk); | |
271 | spin_unlock(&unix_table_lock); | |
272 | } | |
273 | ||
274 | static struct sock *__unix_find_socket_byname(struct net *net, | |
275 | struct sockaddr_un *sunname, | |
276 | int len, int type, unsigned int hash) | |
277 | { | |
278 | struct sock *s; | |
279 | ||
280 | sk_for_each(s, &unix_socket_table[hash ^ type]) { | |
281 | struct unix_sock *u = unix_sk(s); | |
282 | ||
283 | if (!net_eq(sock_net(s), net)) | |
284 | continue; | |
285 | ||
286 | if (u->addr->len == len && | |
287 | !memcmp(u->addr->name, sunname, len)) | |
288 | goto found; | |
289 | } | |
290 | s = NULL; | |
291 | found: | |
292 | return s; | |
293 | } | |
294 | ||
295 | static inline struct sock *unix_find_socket_byname(struct net *net, | |
296 | struct sockaddr_un *sunname, | |
297 | int len, int type, | |
298 | unsigned int hash) | |
299 | { | |
300 | struct sock *s; | |
301 | ||
302 | spin_lock(&unix_table_lock); | |
303 | s = __unix_find_socket_byname(net, sunname, len, type, hash); | |
304 | if (s) | |
305 | sock_hold(s); | |
306 | spin_unlock(&unix_table_lock); | |
307 | return s; | |
308 | } | |
309 | ||
310 | static struct sock *unix_find_socket_byinode(struct inode *i) | |
311 | { | |
312 | struct sock *s; | |
313 | ||
314 | spin_lock(&unix_table_lock); | |
315 | sk_for_each(s, | |
316 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { | |
317 | struct dentry *dentry = unix_sk(s)->path.dentry; | |
318 | ||
319 | if (dentry && d_backing_inode(dentry) == i) { | |
320 | sock_hold(s); | |
321 | goto found; | |
322 | } | |
323 | } | |
324 | s = NULL; | |
325 | found: | |
326 | spin_unlock(&unix_table_lock); | |
327 | return s; | |
328 | } | |
329 | ||
330 | /* Support code for asymmetrically connected dgram sockets | |
331 | * | |
332 | * If a datagram socket is connected to a socket not itself connected | |
333 | * to the first socket (eg, /dev/log), clients may only enqueue more | |
334 | * messages if the present receive queue of the server socket is not | |
335 | * "too large". This means there's a second writeability condition | |
336 | * poll and sendmsg need to test. The dgram recv code will do a wake | |
337 | * up on the peer_wait wait queue of a socket upon reception of a | |
338 | * datagram which needs to be propagated to sleeping would-be writers | |
339 | * since these might not have sent anything so far. This can't be | |
340 | * accomplished via poll_wait because the lifetime of the server | |
341 | * socket might be less than that of its clients if these break their | |
342 | * association with it or if the server socket is closed while clients | |
343 | * are still connected to it and there's no way to inform "a polling | |
344 | * implementation" that it should let go of a certain wait queue | |
345 | * | |
346 | * In order to propagate a wake up, a wait_queue_t of the client | |
347 | * socket is enqueued on the peer_wait queue of the server socket | |
348 | * whose wake function does a wake_up on the ordinary client socket | |
349 | * wait queue. This connection is established whenever a write (or | |
350 | * poll for write) hit the flow control condition and broken when the | |
351 | * association to the server socket is dissolved or after a wake up | |
352 | * was relayed. | |
353 | */ | |
354 | ||
355 | static int unix_dgram_peer_wake_relay(wait_queue_t *q, unsigned mode, int flags, | |
356 | void *key) | |
357 | { | |
358 | struct unix_sock *u; | |
359 | wait_queue_head_t *u_sleep; | |
360 | ||
361 | u = container_of(q, struct unix_sock, peer_wake); | |
362 | ||
363 | __remove_wait_queue(&unix_sk(u->peer_wake.private)->peer_wait, | |
364 | q); | |
365 | u->peer_wake.private = NULL; | |
366 | ||
367 | /* relaying can only happen while the wq still exists */ | |
368 | u_sleep = sk_sleep(&u->sk); | |
369 | if (u_sleep) | |
370 | wake_up_interruptible_poll(u_sleep, key); | |
371 | ||
372 | return 0; | |
373 | } | |
374 | ||
375 | static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other) | |
376 | { | |
377 | struct unix_sock *u, *u_other; | |
378 | int rc; | |
379 | ||
380 | u = unix_sk(sk); | |
381 | u_other = unix_sk(other); | |
382 | rc = 0; | |
383 | spin_lock(&u_other->peer_wait.lock); | |
384 | ||
385 | if (!u->peer_wake.private) { | |
386 | u->peer_wake.private = other; | |
387 | __add_wait_queue(&u_other->peer_wait, &u->peer_wake); | |
388 | ||
389 | rc = 1; | |
390 | } | |
391 | ||
392 | spin_unlock(&u_other->peer_wait.lock); | |
393 | return rc; | |
394 | } | |
395 | ||
396 | static void unix_dgram_peer_wake_disconnect(struct sock *sk, | |
397 | struct sock *other) | |
398 | { | |
399 | struct unix_sock *u, *u_other; | |
400 | ||
401 | u = unix_sk(sk); | |
402 | u_other = unix_sk(other); | |
403 | spin_lock(&u_other->peer_wait.lock); | |
404 | ||
405 | if (u->peer_wake.private == other) { | |
406 | __remove_wait_queue(&u_other->peer_wait, &u->peer_wake); | |
407 | u->peer_wake.private = NULL; | |
408 | } | |
409 | ||
410 | spin_unlock(&u_other->peer_wait.lock); | |
411 | } | |
412 | ||
413 | static void unix_dgram_peer_wake_disconnect_wakeup(struct sock *sk, | |
414 | struct sock *other) | |
415 | { | |
416 | unix_dgram_peer_wake_disconnect(sk, other); | |
417 | wake_up_interruptible_poll(sk_sleep(sk), | |
418 | POLLOUT | | |
419 | POLLWRNORM | | |
420 | POLLWRBAND); | |
421 | } | |
422 | ||
423 | /* preconditions: | |
424 | * - unix_peer(sk) == other | |
425 | * - association is stable | |
426 | */ | |
427 | static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other) | |
428 | { | |
429 | int connected; | |
430 | ||
431 | connected = unix_dgram_peer_wake_connect(sk, other); | |
432 | ||
433 | if (unix_recvq_full(other)) | |
434 | return 1; | |
435 | ||
436 | if (connected) | |
437 | unix_dgram_peer_wake_disconnect(sk, other); | |
438 | ||
439 | return 0; | |
440 | } | |
441 | ||
442 | static int unix_writable(const struct sock *sk) | |
443 | { | |
444 | return sk->sk_state != TCP_LISTEN && | |
445 | (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
446 | } | |
447 | ||
448 | static void unix_write_space(struct sock *sk) | |
449 | { | |
450 | struct socket_wq *wq; | |
451 | ||
452 | rcu_read_lock(); | |
453 | if (unix_writable(sk)) { | |
454 | wq = rcu_dereference(sk->sk_wq); | |
455 | if (skwq_has_sleeper(wq)) | |
456 | wake_up_interruptible_sync_poll(&wq->wait, | |
457 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
458 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); | |
459 | } | |
460 | rcu_read_unlock(); | |
461 | } | |
462 | ||
463 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
464 | * queue of packets arrived from previous peer. First, it allows to do | |
465 | * flow control based only on wmem_alloc; second, sk connected to peer | |
466 | * may receive messages only from that peer. */ | |
467 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
468 | { | |
469 | if (!skb_queue_empty(&sk->sk_receive_queue)) { | |
470 | skb_queue_purge(&sk->sk_receive_queue); | |
471 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
472 | ||
473 | /* If one link of bidirectional dgram pipe is disconnected, | |
474 | * we signal error. Messages are lost. Do not make this, | |
475 | * when peer was not connected to us. | |
476 | */ | |
477 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
478 | other->sk_err = ECONNRESET; | |
479 | other->sk_error_report(other); | |
480 | } | |
481 | } | |
482 | } | |
483 | ||
484 | static void unix_sock_destructor(struct sock *sk) | |
485 | { | |
486 | struct unix_sock *u = unix_sk(sk); | |
487 | ||
488 | skb_queue_purge(&sk->sk_receive_queue); | |
489 | ||
490 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
491 | WARN_ON(!sk_unhashed(sk)); | |
492 | WARN_ON(sk->sk_socket); | |
493 | if (!sock_flag(sk, SOCK_DEAD)) { | |
494 | pr_info("Attempt to release alive unix socket: %p\n", sk); | |
495 | return; | |
496 | } | |
497 | ||
498 | if (u->addr) | |
499 | unix_release_addr(u->addr); | |
500 | ||
501 | atomic_long_dec(&unix_nr_socks); | |
502 | local_bh_disable(); | |
503 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); | |
504 | local_bh_enable(); | |
505 | #ifdef UNIX_REFCNT_DEBUG | |
506 | pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk, | |
507 | atomic_long_read(&unix_nr_socks)); | |
508 | #endif | |
509 | } | |
510 | ||
511 | static void unix_release_sock(struct sock *sk, int embrion) | |
512 | { | |
513 | struct unix_sock *u = unix_sk(sk); | |
514 | struct path path; | |
515 | struct sock *skpair; | |
516 | struct sk_buff *skb; | |
517 | int state; | |
518 | ||
519 | unix_remove_socket(sk); | |
520 | ||
521 | /* Clear state */ | |
522 | unix_state_lock(sk); | |
523 | sock_orphan(sk); | |
524 | sk->sk_shutdown = SHUTDOWN_MASK; | |
525 | path = u->path; | |
526 | u->path.dentry = NULL; | |
527 | u->path.mnt = NULL; | |
528 | state = sk->sk_state; | |
529 | sk->sk_state = TCP_CLOSE; | |
530 | unix_state_unlock(sk); | |
531 | ||
532 | wake_up_interruptible_all(&u->peer_wait); | |
533 | ||
534 | skpair = unix_peer(sk); | |
535 | ||
536 | if (skpair != NULL) { | |
537 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { | |
538 | unix_state_lock(skpair); | |
539 | /* No more writes */ | |
540 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
541 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
542 | skpair->sk_err = ECONNRESET; | |
543 | unix_state_unlock(skpair); | |
544 | skpair->sk_state_change(skpair); | |
545 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); | |
546 | } | |
547 | ||
548 | unix_dgram_peer_wake_disconnect(sk, skpair); | |
549 | sock_put(skpair); /* It may now die */ | |
550 | unix_peer(sk) = NULL; | |
551 | } | |
552 | ||
553 | /* Try to flush out this socket. Throw out buffers at least */ | |
554 | ||
555 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
556 | if (state == TCP_LISTEN) | |
557 | unix_release_sock(skb->sk, 1); | |
558 | /* passed fds are erased in the kfree_skb hook */ | |
559 | UNIXCB(skb).consumed = skb->len; | |
560 | kfree_skb(skb); | |
561 | } | |
562 | ||
563 | if (path.dentry) | |
564 | path_put(&path); | |
565 | ||
566 | sock_put(sk); | |
567 | ||
568 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
569 | ||
570 | /* | |
571 | * Fixme: BSD difference: In BSD all sockets connected to us get | |
572 | * ECONNRESET and we die on the spot. In Linux we behave | |
573 | * like files and pipes do and wait for the last | |
574 | * dereference. | |
575 | * | |
576 | * Can't we simply set sock->err? | |
577 | * | |
578 | * What the above comment does talk about? --ANK(980817) | |
579 | */ | |
580 | ||
581 | if (unix_tot_inflight) | |
582 | unix_gc(); /* Garbage collect fds */ | |
583 | } | |
584 | ||
585 | static void init_peercred(struct sock *sk) | |
586 | { | |
587 | put_pid(sk->sk_peer_pid); | |
588 | if (sk->sk_peer_cred) | |
589 | put_cred(sk->sk_peer_cred); | |
590 | sk->sk_peer_pid = get_pid(task_tgid(current)); | |
591 | sk->sk_peer_cred = get_current_cred(); | |
592 | } | |
593 | ||
594 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
595 | { | |
596 | put_pid(sk->sk_peer_pid); | |
597 | if (sk->sk_peer_cred) | |
598 | put_cred(sk->sk_peer_cred); | |
599 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); | |
600 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
601 | } | |
602 | ||
603 | static int unix_listen(struct socket *sock, int backlog) | |
604 | { | |
605 | int err; | |
606 | struct sock *sk = sock->sk; | |
607 | struct unix_sock *u = unix_sk(sk); | |
608 | struct pid *old_pid = NULL; | |
609 | ||
610 | err = -EOPNOTSUPP; | |
611 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) | |
612 | goto out; /* Only stream/seqpacket sockets accept */ | |
613 | err = -EINVAL; | |
614 | if (!u->addr) | |
615 | goto out; /* No listens on an unbound socket */ | |
616 | unix_state_lock(sk); | |
617 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) | |
618 | goto out_unlock; | |
619 | if (backlog > sk->sk_max_ack_backlog) | |
620 | wake_up_interruptible_all(&u->peer_wait); | |
621 | sk->sk_max_ack_backlog = backlog; | |
622 | sk->sk_state = TCP_LISTEN; | |
623 | /* set credentials so connect can copy them */ | |
624 | init_peercred(sk); | |
625 | err = 0; | |
626 | ||
627 | out_unlock: | |
628 | unix_state_unlock(sk); | |
629 | put_pid(old_pid); | |
630 | out: | |
631 | return err; | |
632 | } | |
633 | ||
634 | static int unix_release(struct socket *); | |
635 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
636 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
637 | int addr_len, int flags); | |
638 | static int unix_socketpair(struct socket *, struct socket *); | |
639 | static int unix_accept(struct socket *, struct socket *, int, bool); | |
640 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
641 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
642 | static unsigned int unix_dgram_poll(struct file *, struct socket *, | |
643 | poll_table *); | |
644 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); | |
645 | static int unix_shutdown(struct socket *, int); | |
646 | static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t); | |
647 | static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
648 | static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset, | |
649 | size_t size, int flags); | |
650 | static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos, | |
651 | struct pipe_inode_info *, size_t size, | |
652 | unsigned int flags); | |
653 | static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t); | |
654 | static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
655 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
656 | int, int); | |
657 | static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t); | |
658 | static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t, | |
659 | int); | |
660 | ||
661 | static int unix_set_peek_off(struct sock *sk, int val) | |
662 | { | |
663 | struct unix_sock *u = unix_sk(sk); | |
664 | ||
665 | if (mutex_lock_interruptible(&u->iolock)) | |
666 | return -EINTR; | |
667 | ||
668 | sk->sk_peek_off = val; | |
669 | mutex_unlock(&u->iolock); | |
670 | ||
671 | return 0; | |
672 | } | |
673 | ||
674 | ||
675 | static const struct proto_ops unix_stream_ops = { | |
676 | .family = PF_UNIX, | |
677 | .owner = THIS_MODULE, | |
678 | .release = unix_release, | |
679 | .bind = unix_bind, | |
680 | .connect = unix_stream_connect, | |
681 | .socketpair = unix_socketpair, | |
682 | .accept = unix_accept, | |
683 | .getname = unix_getname, | |
684 | .poll = unix_poll, | |
685 | .ioctl = unix_ioctl, | |
686 | .listen = unix_listen, | |
687 | .shutdown = unix_shutdown, | |
688 | .setsockopt = sock_no_setsockopt, | |
689 | .getsockopt = sock_no_getsockopt, | |
690 | .sendmsg = unix_stream_sendmsg, | |
691 | .recvmsg = unix_stream_recvmsg, | |
692 | .mmap = sock_no_mmap, | |
693 | .sendpage = unix_stream_sendpage, | |
694 | .splice_read = unix_stream_splice_read, | |
695 | .set_peek_off = unix_set_peek_off, | |
696 | }; | |
697 | ||
698 | static const struct proto_ops unix_dgram_ops = { | |
699 | .family = PF_UNIX, | |
700 | .owner = THIS_MODULE, | |
701 | .release = unix_release, | |
702 | .bind = unix_bind, | |
703 | .connect = unix_dgram_connect, | |
704 | .socketpair = unix_socketpair, | |
705 | .accept = sock_no_accept, | |
706 | .getname = unix_getname, | |
707 | .poll = unix_dgram_poll, | |
708 | .ioctl = unix_ioctl, | |
709 | .listen = sock_no_listen, | |
710 | .shutdown = unix_shutdown, | |
711 | .setsockopt = sock_no_setsockopt, | |
712 | .getsockopt = sock_no_getsockopt, | |
713 | .sendmsg = unix_dgram_sendmsg, | |
714 | .recvmsg = unix_dgram_recvmsg, | |
715 | .mmap = sock_no_mmap, | |
716 | .sendpage = sock_no_sendpage, | |
717 | .set_peek_off = unix_set_peek_off, | |
718 | }; | |
719 | ||
720 | static const struct proto_ops unix_seqpacket_ops = { | |
721 | .family = PF_UNIX, | |
722 | .owner = THIS_MODULE, | |
723 | .release = unix_release, | |
724 | .bind = unix_bind, | |
725 | .connect = unix_stream_connect, | |
726 | .socketpair = unix_socketpair, | |
727 | .accept = unix_accept, | |
728 | .getname = unix_getname, | |
729 | .poll = unix_dgram_poll, | |
730 | .ioctl = unix_ioctl, | |
731 | .listen = unix_listen, | |
732 | .shutdown = unix_shutdown, | |
733 | .setsockopt = sock_no_setsockopt, | |
734 | .getsockopt = sock_no_getsockopt, | |
735 | .sendmsg = unix_seqpacket_sendmsg, | |
736 | .recvmsg = unix_seqpacket_recvmsg, | |
737 | .mmap = sock_no_mmap, | |
738 | .sendpage = sock_no_sendpage, | |
739 | .set_peek_off = unix_set_peek_off, | |
740 | }; | |
741 | ||
742 | static struct proto unix_proto = { | |
743 | .name = "UNIX", | |
744 | .owner = THIS_MODULE, | |
745 | .obj_size = sizeof(struct unix_sock), | |
746 | }; | |
747 | ||
748 | /* | |
749 | * AF_UNIX sockets do not interact with hardware, hence they | |
750 | * dont trigger interrupts - so it's safe for them to have | |
751 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
752 | * this special lock-class by reinitializing the spinlock key: | |
753 | */ | |
754 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
755 | ||
756 | static struct sock *unix_create1(struct net *net, struct socket *sock, int kern) | |
757 | { | |
758 | struct sock *sk = NULL; | |
759 | struct unix_sock *u; | |
760 | ||
761 | atomic_long_inc(&unix_nr_socks); | |
762 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) | |
763 | goto out; | |
764 | ||
765 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto, kern); | |
766 | if (!sk) | |
767 | goto out; | |
768 | ||
769 | sock_init_data(sock, sk); | |
770 | lockdep_set_class(&sk->sk_receive_queue.lock, | |
771 | &af_unix_sk_receive_queue_lock_key); | |
772 | ||
773 | sk->sk_allocation = GFP_KERNEL_ACCOUNT; | |
774 | sk->sk_write_space = unix_write_space; | |
775 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; | |
776 | sk->sk_destruct = unix_sock_destructor; | |
777 | u = unix_sk(sk); | |
778 | u->path.dentry = NULL; | |
779 | u->path.mnt = NULL; | |
780 | spin_lock_init(&u->lock); | |
781 | atomic_long_set(&u->inflight, 0); | |
782 | INIT_LIST_HEAD(&u->link); | |
783 | mutex_init(&u->iolock); /* single task reading lock */ | |
784 | mutex_init(&u->bindlock); /* single task binding lock */ | |
785 | init_waitqueue_head(&u->peer_wait); | |
786 | init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay); | |
787 | unix_insert_socket(unix_sockets_unbound(sk), sk); | |
788 | out: | |
789 | if (sk == NULL) | |
790 | atomic_long_dec(&unix_nr_socks); | |
791 | else { | |
792 | local_bh_disable(); | |
793 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); | |
794 | local_bh_enable(); | |
795 | } | |
796 | return sk; | |
797 | } | |
798 | ||
799 | static int unix_create(struct net *net, struct socket *sock, int protocol, | |
800 | int kern) | |
801 | { | |
802 | if (protocol && protocol != PF_UNIX) | |
803 | return -EPROTONOSUPPORT; | |
804 | ||
805 | sock->state = SS_UNCONNECTED; | |
806 | ||
807 | switch (sock->type) { | |
808 | case SOCK_STREAM: | |
809 | sock->ops = &unix_stream_ops; | |
810 | break; | |
811 | /* | |
812 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
813 | * nothing uses it. | |
814 | */ | |
815 | case SOCK_RAW: | |
816 | sock->type = SOCK_DGRAM; | |
817 | case SOCK_DGRAM: | |
818 | sock->ops = &unix_dgram_ops; | |
819 | break; | |
820 | case SOCK_SEQPACKET: | |
821 | sock->ops = &unix_seqpacket_ops; | |
822 | break; | |
823 | default: | |
824 | return -ESOCKTNOSUPPORT; | |
825 | } | |
826 | ||
827 | return unix_create1(net, sock, kern) ? 0 : -ENOMEM; | |
828 | } | |
829 | ||
830 | static int unix_release(struct socket *sock) | |
831 | { | |
832 | struct sock *sk = sock->sk; | |
833 | ||
834 | if (!sk) | |
835 | return 0; | |
836 | ||
837 | unix_release_sock(sk, 0); | |
838 | sock->sk = NULL; | |
839 | ||
840 | return 0; | |
841 | } | |
842 | ||
843 | static int unix_autobind(struct socket *sock) | |
844 | { | |
845 | struct sock *sk = sock->sk; | |
846 | struct net *net = sock_net(sk); | |
847 | struct unix_sock *u = unix_sk(sk); | |
848 | static u32 ordernum = 1; | |
849 | struct unix_address *addr; | |
850 | int err; | |
851 | unsigned int retries = 0; | |
852 | ||
853 | err = mutex_lock_interruptible(&u->bindlock); | |
854 | if (err) | |
855 | return err; | |
856 | ||
857 | err = 0; | |
858 | if (u->addr) | |
859 | goto out; | |
860 | ||
861 | err = -ENOMEM; | |
862 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); | |
863 | if (!addr) | |
864 | goto out; | |
865 | ||
866 | addr->name->sun_family = AF_UNIX; | |
867 | atomic_set(&addr->refcnt, 1); | |
868 | ||
869 | retry: | |
870 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
871 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); | |
872 | ||
873 | spin_lock(&unix_table_lock); | |
874 | ordernum = (ordernum+1)&0xFFFFF; | |
875 | ||
876 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, | |
877 | addr->hash)) { | |
878 | spin_unlock(&unix_table_lock); | |
879 | /* | |
880 | * __unix_find_socket_byname() may take long time if many names | |
881 | * are already in use. | |
882 | */ | |
883 | cond_resched(); | |
884 | /* Give up if all names seems to be in use. */ | |
885 | if (retries++ == 0xFFFFF) { | |
886 | err = -ENOSPC; | |
887 | kfree(addr); | |
888 | goto out; | |
889 | } | |
890 | goto retry; | |
891 | } | |
892 | addr->hash ^= sk->sk_type; | |
893 | ||
894 | __unix_remove_socket(sk); | |
895 | u->addr = addr; | |
896 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
897 | spin_unlock(&unix_table_lock); | |
898 | err = 0; | |
899 | ||
900 | out: mutex_unlock(&u->bindlock); | |
901 | return err; | |
902 | } | |
903 | ||
904 | static struct sock *unix_find_other(struct net *net, | |
905 | struct sockaddr_un *sunname, int len, | |
906 | int type, unsigned int hash, int *error) | |
907 | { | |
908 | struct sock *u; | |
909 | struct path path; | |
910 | int err = 0; | |
911 | ||
912 | if (sunname->sun_path[0]) { | |
913 | struct inode *inode; | |
914 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
915 | if (err) | |
916 | goto fail; | |
917 | inode = d_backing_inode(path.dentry); | |
918 | err = inode_permission(inode, MAY_WRITE); | |
919 | if (err) | |
920 | goto put_fail; | |
921 | ||
922 | err = -ECONNREFUSED; | |
923 | if (!S_ISSOCK(inode->i_mode)) | |
924 | goto put_fail; | |
925 | u = unix_find_socket_byinode(inode); | |
926 | if (!u) | |
927 | goto put_fail; | |
928 | ||
929 | if (u->sk_type == type) | |
930 | touch_atime(&path); | |
931 | ||
932 | path_put(&path); | |
933 | ||
934 | err = -EPROTOTYPE; | |
935 | if (u->sk_type != type) { | |
936 | sock_put(u); | |
937 | goto fail; | |
938 | } | |
939 | } else { | |
940 | err = -ECONNREFUSED; | |
941 | u = unix_find_socket_byname(net, sunname, len, type, hash); | |
942 | if (u) { | |
943 | struct dentry *dentry; | |
944 | dentry = unix_sk(u)->path.dentry; | |
945 | if (dentry) | |
946 | touch_atime(&unix_sk(u)->path); | |
947 | } else | |
948 | goto fail; | |
949 | } | |
950 | return u; | |
951 | ||
952 | put_fail: | |
953 | path_put(&path); | |
954 | fail: | |
955 | *error = err; | |
956 | return NULL; | |
957 | } | |
958 | ||
959 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) | |
960 | { | |
961 | struct dentry *dentry; | |
962 | struct path path; | |
963 | int err = 0; | |
964 | /* | |
965 | * Get the parent directory, calculate the hash for last | |
966 | * component. | |
967 | */ | |
968 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); | |
969 | err = PTR_ERR(dentry); | |
970 | if (IS_ERR(dentry)) | |
971 | return err; | |
972 | ||
973 | /* | |
974 | * All right, let's create it. | |
975 | */ | |
976 | err = security_path_mknod(&path, dentry, mode, 0); | |
977 | if (!err) { | |
978 | err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0); | |
979 | if (!err) { | |
980 | res->mnt = mntget(path.mnt); | |
981 | res->dentry = dget(dentry); | |
982 | } | |
983 | } | |
984 | done_path_create(&path, dentry); | |
985 | return err; | |
986 | } | |
987 | ||
988 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
989 | { | |
990 | struct sock *sk = sock->sk; | |
991 | struct net *net = sock_net(sk); | |
992 | struct unix_sock *u = unix_sk(sk); | |
993 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; | |
994 | char *sun_path = sunaddr->sun_path; | |
995 | int err; | |
996 | unsigned int hash; | |
997 | struct unix_address *addr; | |
998 | struct hlist_head *list; | |
999 | struct path path = { }; | |
1000 | ||
1001 | err = -EINVAL; | |
1002 | if (addr_len < offsetofend(struct sockaddr_un, sun_family) || | |
1003 | sunaddr->sun_family != AF_UNIX) | |
1004 | goto out; | |
1005 | ||
1006 | if (addr_len == sizeof(short)) { | |
1007 | err = unix_autobind(sock); | |
1008 | goto out; | |
1009 | } | |
1010 | ||
1011 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1012 | if (err < 0) | |
1013 | goto out; | |
1014 | addr_len = err; | |
1015 | ||
1016 | if (sun_path[0]) { | |
1017 | umode_t mode = S_IFSOCK | | |
1018 | (SOCK_INODE(sock)->i_mode & ~current_umask()); | |
1019 | err = unix_mknod(sun_path, mode, &path); | |
1020 | if (err) { | |
1021 | if (err == -EEXIST) | |
1022 | err = -EADDRINUSE; | |
1023 | goto out; | |
1024 | } | |
1025 | } | |
1026 | ||
1027 | err = mutex_lock_interruptible(&u->bindlock); | |
1028 | if (err) | |
1029 | goto out_put; | |
1030 | ||
1031 | err = -EINVAL; | |
1032 | if (u->addr) | |
1033 | goto out_up; | |
1034 | ||
1035 | err = -ENOMEM; | |
1036 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
1037 | if (!addr) | |
1038 | goto out_up; | |
1039 | ||
1040 | memcpy(addr->name, sunaddr, addr_len); | |
1041 | addr->len = addr_len; | |
1042 | addr->hash = hash ^ sk->sk_type; | |
1043 | atomic_set(&addr->refcnt, 1); | |
1044 | ||
1045 | if (sun_path[0]) { | |
1046 | addr->hash = UNIX_HASH_SIZE; | |
1047 | hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1); | |
1048 | spin_lock(&unix_table_lock); | |
1049 | u->path = path; | |
1050 | list = &unix_socket_table[hash]; | |
1051 | } else { | |
1052 | spin_lock(&unix_table_lock); | |
1053 | err = -EADDRINUSE; | |
1054 | if (__unix_find_socket_byname(net, sunaddr, addr_len, | |
1055 | sk->sk_type, hash)) { | |
1056 | unix_release_addr(addr); | |
1057 | goto out_unlock; | |
1058 | } | |
1059 | ||
1060 | list = &unix_socket_table[addr->hash]; | |
1061 | } | |
1062 | ||
1063 | err = 0; | |
1064 | __unix_remove_socket(sk); | |
1065 | u->addr = addr; | |
1066 | __unix_insert_socket(list, sk); | |
1067 | ||
1068 | out_unlock: | |
1069 | spin_unlock(&unix_table_lock); | |
1070 | out_up: | |
1071 | mutex_unlock(&u->bindlock); | |
1072 | out_put: | |
1073 | if (err) | |
1074 | path_put(&path); | |
1075 | out: | |
1076 | return err; | |
1077 | } | |
1078 | ||
1079 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) | |
1080 | { | |
1081 | if (unlikely(sk1 == sk2) || !sk2) { | |
1082 | unix_state_lock(sk1); | |
1083 | return; | |
1084 | } | |
1085 | if (sk1 < sk2) { | |
1086 | unix_state_lock(sk1); | |
1087 | unix_state_lock_nested(sk2); | |
1088 | } else { | |
1089 | unix_state_lock(sk2); | |
1090 | unix_state_lock_nested(sk1); | |
1091 | } | |
1092 | } | |
1093 | ||
1094 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
1095 | { | |
1096 | if (unlikely(sk1 == sk2) || !sk2) { | |
1097 | unix_state_unlock(sk1); | |
1098 | return; | |
1099 | } | |
1100 | unix_state_unlock(sk1); | |
1101 | unix_state_unlock(sk2); | |
1102 | } | |
1103 | ||
1104 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, | |
1105 | int alen, int flags) | |
1106 | { | |
1107 | struct sock *sk = sock->sk; | |
1108 | struct net *net = sock_net(sk); | |
1109 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; | |
1110 | struct sock *other; | |
1111 | unsigned int hash; | |
1112 | int err; | |
1113 | ||
1114 | err = -EINVAL; | |
1115 | if (alen < offsetofend(struct sockaddr, sa_family)) | |
1116 | goto out; | |
1117 | ||
1118 | if (addr->sa_family != AF_UNSPEC) { | |
1119 | err = unix_mkname(sunaddr, alen, &hash); | |
1120 | if (err < 0) | |
1121 | goto out; | |
1122 | alen = err; | |
1123 | ||
1124 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
1125 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
1126 | goto out; | |
1127 | ||
1128 | restart: | |
1129 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); | |
1130 | if (!other) | |
1131 | goto out; | |
1132 | ||
1133 | unix_state_double_lock(sk, other); | |
1134 | ||
1135 | /* Apparently VFS overslept socket death. Retry. */ | |
1136 | if (sock_flag(other, SOCK_DEAD)) { | |
1137 | unix_state_double_unlock(sk, other); | |
1138 | sock_put(other); | |
1139 | goto restart; | |
1140 | } | |
1141 | ||
1142 | err = -EPERM; | |
1143 | if (!unix_may_send(sk, other)) | |
1144 | goto out_unlock; | |
1145 | ||
1146 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1147 | if (err) | |
1148 | goto out_unlock; | |
1149 | ||
1150 | } else { | |
1151 | /* | |
1152 | * 1003.1g breaking connected state with AF_UNSPEC | |
1153 | */ | |
1154 | other = NULL; | |
1155 | unix_state_double_lock(sk, other); | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * If it was connected, reconnect. | |
1160 | */ | |
1161 | if (unix_peer(sk)) { | |
1162 | struct sock *old_peer = unix_peer(sk); | |
1163 | unix_peer(sk) = other; | |
1164 | unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer); | |
1165 | ||
1166 | unix_state_double_unlock(sk, other); | |
1167 | ||
1168 | if (other != old_peer) | |
1169 | unix_dgram_disconnected(sk, old_peer); | |
1170 | sock_put(old_peer); | |
1171 | } else { | |
1172 | unix_peer(sk) = other; | |
1173 | unix_state_double_unlock(sk, other); | |
1174 | } | |
1175 | return 0; | |
1176 | ||
1177 | out_unlock: | |
1178 | unix_state_double_unlock(sk, other); | |
1179 | sock_put(other); | |
1180 | out: | |
1181 | return err; | |
1182 | } | |
1183 | ||
1184 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1185 | { | |
1186 | struct unix_sock *u = unix_sk(other); | |
1187 | int sched; | |
1188 | DEFINE_WAIT(wait); | |
1189 | ||
1190 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1191 | ||
1192 | sched = !sock_flag(other, SOCK_DEAD) && | |
1193 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
1194 | unix_recvq_full(other); | |
1195 | ||
1196 | unix_state_unlock(other); | |
1197 | ||
1198 | if (sched) | |
1199 | timeo = schedule_timeout(timeo); | |
1200 | ||
1201 | finish_wait(&u->peer_wait, &wait); | |
1202 | return timeo; | |
1203 | } | |
1204 | ||
1205 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1206 | int addr_len, int flags) | |
1207 | { | |
1208 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; | |
1209 | struct sock *sk = sock->sk; | |
1210 | struct net *net = sock_net(sk); | |
1211 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; | |
1212 | struct sock *newsk = NULL; | |
1213 | struct sock *other = NULL; | |
1214 | struct sk_buff *skb = NULL; | |
1215 | unsigned int hash; | |
1216 | int st; | |
1217 | int err; | |
1218 | long timeo; | |
1219 | ||
1220 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1221 | if (err < 0) | |
1222 | goto out; | |
1223 | addr_len = err; | |
1224 | ||
1225 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && | |
1226 | (err = unix_autobind(sock)) != 0) | |
1227 | goto out; | |
1228 | ||
1229 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1230 | ||
1231 | /* First of all allocate resources. | |
1232 | If we will make it after state is locked, | |
1233 | we will have to recheck all again in any case. | |
1234 | */ | |
1235 | ||
1236 | err = -ENOMEM; | |
1237 | ||
1238 | /* create new sock for complete connection */ | |
1239 | newsk = unix_create1(sock_net(sk), NULL, 0); | |
1240 | if (newsk == NULL) | |
1241 | goto out; | |
1242 | ||
1243 | /* Allocate skb for sending to listening sock */ | |
1244 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1245 | if (skb == NULL) | |
1246 | goto out; | |
1247 | ||
1248 | restart: | |
1249 | /* Find listening sock. */ | |
1250 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); | |
1251 | if (!other) | |
1252 | goto out; | |
1253 | ||
1254 | /* Latch state of peer */ | |
1255 | unix_state_lock(other); | |
1256 | ||
1257 | /* Apparently VFS overslept socket death. Retry. */ | |
1258 | if (sock_flag(other, SOCK_DEAD)) { | |
1259 | unix_state_unlock(other); | |
1260 | sock_put(other); | |
1261 | goto restart; | |
1262 | } | |
1263 | ||
1264 | err = -ECONNREFUSED; | |
1265 | if (other->sk_state != TCP_LISTEN) | |
1266 | goto out_unlock; | |
1267 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1268 | goto out_unlock; | |
1269 | ||
1270 | if (unix_recvq_full(other)) { | |
1271 | err = -EAGAIN; | |
1272 | if (!timeo) | |
1273 | goto out_unlock; | |
1274 | ||
1275 | timeo = unix_wait_for_peer(other, timeo); | |
1276 | ||
1277 | err = sock_intr_errno(timeo); | |
1278 | if (signal_pending(current)) | |
1279 | goto out; | |
1280 | sock_put(other); | |
1281 | goto restart; | |
1282 | } | |
1283 | ||
1284 | /* Latch our state. | |
1285 | ||
1286 | It is tricky place. We need to grab our state lock and cannot | |
1287 | drop lock on peer. It is dangerous because deadlock is | |
1288 | possible. Connect to self case and simultaneous | |
1289 | attempt to connect are eliminated by checking socket | |
1290 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1291 | check this before attempt to grab lock. | |
1292 | ||
1293 | Well, and we have to recheck the state after socket locked. | |
1294 | */ | |
1295 | st = sk->sk_state; | |
1296 | ||
1297 | switch (st) { | |
1298 | case TCP_CLOSE: | |
1299 | /* This is ok... continue with connect */ | |
1300 | break; | |
1301 | case TCP_ESTABLISHED: | |
1302 | /* Socket is already connected */ | |
1303 | err = -EISCONN; | |
1304 | goto out_unlock; | |
1305 | default: | |
1306 | err = -EINVAL; | |
1307 | goto out_unlock; | |
1308 | } | |
1309 | ||
1310 | unix_state_lock_nested(sk); | |
1311 | ||
1312 | if (sk->sk_state != st) { | |
1313 | unix_state_unlock(sk); | |
1314 | unix_state_unlock(other); | |
1315 | sock_put(other); | |
1316 | goto restart; | |
1317 | } | |
1318 | ||
1319 | err = security_unix_stream_connect(sk, other, newsk); | |
1320 | if (err) { | |
1321 | unix_state_unlock(sk); | |
1322 | goto out_unlock; | |
1323 | } | |
1324 | ||
1325 | /* The way is open! Fastly set all the necessary fields... */ | |
1326 | ||
1327 | sock_hold(sk); | |
1328 | unix_peer(newsk) = sk; | |
1329 | newsk->sk_state = TCP_ESTABLISHED; | |
1330 | newsk->sk_type = sk->sk_type; | |
1331 | init_peercred(newsk); | |
1332 | newu = unix_sk(newsk); | |
1333 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); | |
1334 | otheru = unix_sk(other); | |
1335 | ||
1336 | /* copy address information from listening to new sock*/ | |
1337 | if (otheru->addr) { | |
1338 | atomic_inc(&otheru->addr->refcnt); | |
1339 | newu->addr = otheru->addr; | |
1340 | } | |
1341 | if (otheru->path.dentry) { | |
1342 | path_get(&otheru->path); | |
1343 | newu->path = otheru->path; | |
1344 | } | |
1345 | ||
1346 | /* Set credentials */ | |
1347 | copy_peercred(sk, other); | |
1348 | ||
1349 | sock->state = SS_CONNECTED; | |
1350 | sk->sk_state = TCP_ESTABLISHED; | |
1351 | sock_hold(newsk); | |
1352 | ||
1353 | smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */ | |
1354 | unix_peer(sk) = newsk; | |
1355 | ||
1356 | unix_state_unlock(sk); | |
1357 | ||
1358 | /* take ten and and send info to listening sock */ | |
1359 | spin_lock(&other->sk_receive_queue.lock); | |
1360 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1361 | spin_unlock(&other->sk_receive_queue.lock); | |
1362 | unix_state_unlock(other); | |
1363 | other->sk_data_ready(other); | |
1364 | sock_put(other); | |
1365 | return 0; | |
1366 | ||
1367 | out_unlock: | |
1368 | if (other) | |
1369 | unix_state_unlock(other); | |
1370 | ||
1371 | out: | |
1372 | kfree_skb(skb); | |
1373 | if (newsk) | |
1374 | unix_release_sock(newsk, 0); | |
1375 | if (other) | |
1376 | sock_put(other); | |
1377 | return err; | |
1378 | } | |
1379 | ||
1380 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1381 | { | |
1382 | struct sock *ska = socka->sk, *skb = sockb->sk; | |
1383 | ||
1384 | /* Join our sockets back to back */ | |
1385 | sock_hold(ska); | |
1386 | sock_hold(skb); | |
1387 | unix_peer(ska) = skb; | |
1388 | unix_peer(skb) = ska; | |
1389 | init_peercred(ska); | |
1390 | init_peercred(skb); | |
1391 | ||
1392 | if (ska->sk_type != SOCK_DGRAM) { | |
1393 | ska->sk_state = TCP_ESTABLISHED; | |
1394 | skb->sk_state = TCP_ESTABLISHED; | |
1395 | socka->state = SS_CONNECTED; | |
1396 | sockb->state = SS_CONNECTED; | |
1397 | } | |
1398 | return 0; | |
1399 | } | |
1400 | ||
1401 | static void unix_sock_inherit_flags(const struct socket *old, | |
1402 | struct socket *new) | |
1403 | { | |
1404 | if (test_bit(SOCK_PASSCRED, &old->flags)) | |
1405 | set_bit(SOCK_PASSCRED, &new->flags); | |
1406 | if (test_bit(SOCK_PASSSEC, &old->flags)) | |
1407 | set_bit(SOCK_PASSSEC, &new->flags); | |
1408 | } | |
1409 | ||
1410 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags, | |
1411 | bool kern) | |
1412 | { | |
1413 | struct sock *sk = sock->sk; | |
1414 | struct sock *tsk; | |
1415 | struct sk_buff *skb; | |
1416 | int err; | |
1417 | ||
1418 | err = -EOPNOTSUPP; | |
1419 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) | |
1420 | goto out; | |
1421 | ||
1422 | err = -EINVAL; | |
1423 | if (sk->sk_state != TCP_LISTEN) | |
1424 | goto out; | |
1425 | ||
1426 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1427 | * so that no locks are necessary. | |
1428 | */ | |
1429 | ||
1430 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1431 | if (!skb) { | |
1432 | /* This means receive shutdown. */ | |
1433 | if (err == 0) | |
1434 | err = -EINVAL; | |
1435 | goto out; | |
1436 | } | |
1437 | ||
1438 | tsk = skb->sk; | |
1439 | skb_free_datagram(sk, skb); | |
1440 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1441 | ||
1442 | /* attach accepted sock to socket */ | |
1443 | unix_state_lock(tsk); | |
1444 | newsock->state = SS_CONNECTED; | |
1445 | unix_sock_inherit_flags(sock, newsock); | |
1446 | sock_graft(tsk, newsock); | |
1447 | unix_state_unlock(tsk); | |
1448 | return 0; | |
1449 | ||
1450 | out: | |
1451 | return err; | |
1452 | } | |
1453 | ||
1454 | ||
1455 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1456 | { | |
1457 | struct sock *sk = sock->sk; | |
1458 | struct unix_sock *u; | |
1459 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); | |
1460 | int err = 0; | |
1461 | ||
1462 | if (peer) { | |
1463 | sk = unix_peer_get(sk); | |
1464 | ||
1465 | err = -ENOTCONN; | |
1466 | if (!sk) | |
1467 | goto out; | |
1468 | err = 0; | |
1469 | } else { | |
1470 | sock_hold(sk); | |
1471 | } | |
1472 | ||
1473 | u = unix_sk(sk); | |
1474 | unix_state_lock(sk); | |
1475 | if (!u->addr) { | |
1476 | sunaddr->sun_family = AF_UNIX; | |
1477 | sunaddr->sun_path[0] = 0; | |
1478 | *uaddr_len = sizeof(short); | |
1479 | } else { | |
1480 | struct unix_address *addr = u->addr; | |
1481 | ||
1482 | *uaddr_len = addr->len; | |
1483 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1484 | } | |
1485 | unix_state_unlock(sk); | |
1486 | sock_put(sk); | |
1487 | out: | |
1488 | return err; | |
1489 | } | |
1490 | ||
1491 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1492 | { | |
1493 | int i; | |
1494 | ||
1495 | scm->fp = UNIXCB(skb).fp; | |
1496 | UNIXCB(skb).fp = NULL; | |
1497 | ||
1498 | for (i = scm->fp->count-1; i >= 0; i--) | |
1499 | unix_notinflight(scm->fp->user, scm->fp->fp[i]); | |
1500 | } | |
1501 | ||
1502 | static void unix_destruct_scm(struct sk_buff *skb) | |
1503 | { | |
1504 | struct scm_cookie scm; | |
1505 | memset(&scm, 0, sizeof(scm)); | |
1506 | scm.pid = UNIXCB(skb).pid; | |
1507 | if (UNIXCB(skb).fp) | |
1508 | unix_detach_fds(&scm, skb); | |
1509 | ||
1510 | /* Alas, it calls VFS */ | |
1511 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1512 | scm_destroy(&scm); | |
1513 | sock_wfree(skb); | |
1514 | } | |
1515 | ||
1516 | /* | |
1517 | * The "user->unix_inflight" variable is protected by the garbage | |
1518 | * collection lock, and we just read it locklessly here. If you go | |
1519 | * over the limit, there might be a tiny race in actually noticing | |
1520 | * it across threads. Tough. | |
1521 | */ | |
1522 | static inline bool too_many_unix_fds(struct task_struct *p) | |
1523 | { | |
1524 | struct user_struct *user = current_user(); | |
1525 | ||
1526 | if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE))) | |
1527 | return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN); | |
1528 | return false; | |
1529 | } | |
1530 | ||
1531 | #define MAX_RECURSION_LEVEL 4 | |
1532 | ||
1533 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1534 | { | |
1535 | int i; | |
1536 | unsigned char max_level = 0; | |
1537 | ||
1538 | if (too_many_unix_fds(current)) | |
1539 | return -ETOOMANYREFS; | |
1540 | ||
1541 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1542 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1543 | ||
1544 | if (sk) | |
1545 | max_level = max(max_level, | |
1546 | unix_sk(sk)->recursion_level); | |
1547 | } | |
1548 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1549 | return -ETOOMANYREFS; | |
1550 | ||
1551 | /* | |
1552 | * Need to duplicate file references for the sake of garbage | |
1553 | * collection. Otherwise a socket in the fps might become a | |
1554 | * candidate for GC while the skb is not yet queued. | |
1555 | */ | |
1556 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1557 | if (!UNIXCB(skb).fp) | |
1558 | return -ENOMEM; | |
1559 | ||
1560 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1561 | unix_inflight(scm->fp->user, scm->fp->fp[i]); | |
1562 | return max_level; | |
1563 | } | |
1564 | ||
1565 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) | |
1566 | { | |
1567 | int err = 0; | |
1568 | ||
1569 | UNIXCB(skb).pid = get_pid(scm->pid); | |
1570 | UNIXCB(skb).uid = scm->creds.uid; | |
1571 | UNIXCB(skb).gid = scm->creds.gid; | |
1572 | UNIXCB(skb).fp = NULL; | |
1573 | unix_get_secdata(scm, skb); | |
1574 | if (scm->fp && send_fds) | |
1575 | err = unix_attach_fds(scm, skb); | |
1576 | ||
1577 | skb->destructor = unix_destruct_scm; | |
1578 | return err; | |
1579 | } | |
1580 | ||
1581 | static bool unix_passcred_enabled(const struct socket *sock, | |
1582 | const struct sock *other) | |
1583 | { | |
1584 | return test_bit(SOCK_PASSCRED, &sock->flags) || | |
1585 | !other->sk_socket || | |
1586 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags); | |
1587 | } | |
1588 | ||
1589 | /* | |
1590 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1591 | * We include credentials if source or destination socket | |
1592 | * asserted SOCK_PASSCRED. | |
1593 | */ | |
1594 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1595 | const struct sock *other) | |
1596 | { | |
1597 | if (UNIXCB(skb).pid) | |
1598 | return; | |
1599 | if (unix_passcred_enabled(sock, other)) { | |
1600 | UNIXCB(skb).pid = get_pid(task_tgid(current)); | |
1601 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); | |
1602 | } | |
1603 | } | |
1604 | ||
1605 | static int maybe_init_creds(struct scm_cookie *scm, | |
1606 | struct socket *socket, | |
1607 | const struct sock *other) | |
1608 | { | |
1609 | int err; | |
1610 | struct msghdr msg = { .msg_controllen = 0 }; | |
1611 | ||
1612 | err = scm_send(socket, &msg, scm, false); | |
1613 | if (err) | |
1614 | return err; | |
1615 | ||
1616 | if (unix_passcred_enabled(socket, other)) { | |
1617 | scm->pid = get_pid(task_tgid(current)); | |
1618 | current_uid_gid(&scm->creds.uid, &scm->creds.gid); | |
1619 | } | |
1620 | return err; | |
1621 | } | |
1622 | ||
1623 | static bool unix_skb_scm_eq(struct sk_buff *skb, | |
1624 | struct scm_cookie *scm) | |
1625 | { | |
1626 | const struct unix_skb_parms *u = &UNIXCB(skb); | |
1627 | ||
1628 | return u->pid == scm->pid && | |
1629 | uid_eq(u->uid, scm->creds.uid) && | |
1630 | gid_eq(u->gid, scm->creds.gid) && | |
1631 | unix_secdata_eq(scm, skb); | |
1632 | } | |
1633 | ||
1634 | /* | |
1635 | * Send AF_UNIX data. | |
1636 | */ | |
1637 | ||
1638 | static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, | |
1639 | size_t len) | |
1640 | { | |
1641 | struct sock *sk = sock->sk; | |
1642 | struct net *net = sock_net(sk); | |
1643 | struct unix_sock *u = unix_sk(sk); | |
1644 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); | |
1645 | struct sock *other = NULL; | |
1646 | int namelen = 0; /* fake GCC */ | |
1647 | int err; | |
1648 | unsigned int hash; | |
1649 | struct sk_buff *skb; | |
1650 | long timeo; | |
1651 | struct scm_cookie scm; | |
1652 | int max_level; | |
1653 | int data_len = 0; | |
1654 | int sk_locked; | |
1655 | ||
1656 | wait_for_unix_gc(); | |
1657 | err = scm_send(sock, msg, &scm, false); | |
1658 | if (err < 0) | |
1659 | return err; | |
1660 | ||
1661 | err = -EOPNOTSUPP; | |
1662 | if (msg->msg_flags&MSG_OOB) | |
1663 | goto out; | |
1664 | ||
1665 | if (msg->msg_namelen) { | |
1666 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1667 | if (err < 0) | |
1668 | goto out; | |
1669 | namelen = err; | |
1670 | } else { | |
1671 | sunaddr = NULL; | |
1672 | err = -ENOTCONN; | |
1673 | other = unix_peer_get(sk); | |
1674 | if (!other) | |
1675 | goto out; | |
1676 | } | |
1677 | ||
1678 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr | |
1679 | && (err = unix_autobind(sock)) != 0) | |
1680 | goto out; | |
1681 | ||
1682 | err = -EMSGSIZE; | |
1683 | if (len > sk->sk_sndbuf - 32) | |
1684 | goto out; | |
1685 | ||
1686 | if (len > SKB_MAX_ALLOC) { | |
1687 | data_len = min_t(size_t, | |
1688 | len - SKB_MAX_ALLOC, | |
1689 | MAX_SKB_FRAGS * PAGE_SIZE); | |
1690 | data_len = PAGE_ALIGN(data_len); | |
1691 | ||
1692 | BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE); | |
1693 | } | |
1694 | ||
1695 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
1696 | msg->msg_flags & MSG_DONTWAIT, &err, | |
1697 | PAGE_ALLOC_COSTLY_ORDER); | |
1698 | if (skb == NULL) | |
1699 | goto out; | |
1700 | ||
1701 | err = unix_scm_to_skb(&scm, skb, true); | |
1702 | if (err < 0) | |
1703 | goto out_free; | |
1704 | max_level = err + 1; | |
1705 | ||
1706 | skb_put(skb, len - data_len); | |
1707 | skb->data_len = data_len; | |
1708 | skb->len = len; | |
1709 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len); | |
1710 | if (err) | |
1711 | goto out_free; | |
1712 | ||
1713 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1714 | ||
1715 | restart: | |
1716 | if (!other) { | |
1717 | err = -ECONNRESET; | |
1718 | if (sunaddr == NULL) | |
1719 | goto out_free; | |
1720 | ||
1721 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, | |
1722 | hash, &err); | |
1723 | if (other == NULL) | |
1724 | goto out_free; | |
1725 | } | |
1726 | ||
1727 | if (sk_filter(other, skb) < 0) { | |
1728 | /* Toss the packet but do not return any error to the sender */ | |
1729 | err = len; | |
1730 | goto out_free; | |
1731 | } | |
1732 | ||
1733 | sk_locked = 0; | |
1734 | unix_state_lock(other); | |
1735 | restart_locked: | |
1736 | err = -EPERM; | |
1737 | if (!unix_may_send(sk, other)) | |
1738 | goto out_unlock; | |
1739 | ||
1740 | if (unlikely(sock_flag(other, SOCK_DEAD))) { | |
1741 | /* | |
1742 | * Check with 1003.1g - what should | |
1743 | * datagram error | |
1744 | */ | |
1745 | unix_state_unlock(other); | |
1746 | sock_put(other); | |
1747 | ||
1748 | if (!sk_locked) | |
1749 | unix_state_lock(sk); | |
1750 | ||
1751 | err = 0; | |
1752 | if (unix_peer(sk) == other) { | |
1753 | unix_peer(sk) = NULL; | |
1754 | unix_dgram_peer_wake_disconnect_wakeup(sk, other); | |
1755 | ||
1756 | unix_state_unlock(sk); | |
1757 | ||
1758 | unix_dgram_disconnected(sk, other); | |
1759 | sock_put(other); | |
1760 | err = -ECONNREFUSED; | |
1761 | } else { | |
1762 | unix_state_unlock(sk); | |
1763 | } | |
1764 | ||
1765 | other = NULL; | |
1766 | if (err) | |
1767 | goto out_free; | |
1768 | goto restart; | |
1769 | } | |
1770 | ||
1771 | err = -EPIPE; | |
1772 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1773 | goto out_unlock; | |
1774 | ||
1775 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1776 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1777 | if (err) | |
1778 | goto out_unlock; | |
1779 | } | |
1780 | ||
1781 | /* other == sk && unix_peer(other) != sk if | |
1782 | * - unix_peer(sk) == NULL, destination address bound to sk | |
1783 | * - unix_peer(sk) == sk by time of get but disconnected before lock | |
1784 | */ | |
1785 | if (other != sk && | |
1786 | unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { | |
1787 | if (timeo) { | |
1788 | timeo = unix_wait_for_peer(other, timeo); | |
1789 | ||
1790 | err = sock_intr_errno(timeo); | |
1791 | if (signal_pending(current)) | |
1792 | goto out_free; | |
1793 | ||
1794 | goto restart; | |
1795 | } | |
1796 | ||
1797 | if (!sk_locked) { | |
1798 | unix_state_unlock(other); | |
1799 | unix_state_double_lock(sk, other); | |
1800 | } | |
1801 | ||
1802 | if (unix_peer(sk) != other || | |
1803 | unix_dgram_peer_wake_me(sk, other)) { | |
1804 | err = -EAGAIN; | |
1805 | sk_locked = 1; | |
1806 | goto out_unlock; | |
1807 | } | |
1808 | ||
1809 | if (!sk_locked) { | |
1810 | sk_locked = 1; | |
1811 | goto restart_locked; | |
1812 | } | |
1813 | } | |
1814 | ||
1815 | if (unlikely(sk_locked)) | |
1816 | unix_state_unlock(sk); | |
1817 | ||
1818 | if (sock_flag(other, SOCK_RCVTSTAMP)) | |
1819 | __net_timestamp(skb); | |
1820 | maybe_add_creds(skb, sock, other); | |
1821 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1822 | if (max_level > unix_sk(other)->recursion_level) | |
1823 | unix_sk(other)->recursion_level = max_level; | |
1824 | unix_state_unlock(other); | |
1825 | other->sk_data_ready(other); | |
1826 | sock_put(other); | |
1827 | scm_destroy(&scm); | |
1828 | return len; | |
1829 | ||
1830 | out_unlock: | |
1831 | if (sk_locked) | |
1832 | unix_state_unlock(sk); | |
1833 | unix_state_unlock(other); | |
1834 | out_free: | |
1835 | kfree_skb(skb); | |
1836 | out: | |
1837 | if (other) | |
1838 | sock_put(other); | |
1839 | scm_destroy(&scm); | |
1840 | return err; | |
1841 | } | |
1842 | ||
1843 | /* We use paged skbs for stream sockets, and limit occupancy to 32768 | |
1844 | * bytes, and a minimun of a full page. | |
1845 | */ | |
1846 | #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) | |
1847 | ||
1848 | static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, | |
1849 | size_t len) | |
1850 | { | |
1851 | struct sock *sk = sock->sk; | |
1852 | struct sock *other = NULL; | |
1853 | int err, size; | |
1854 | struct sk_buff *skb; | |
1855 | int sent = 0; | |
1856 | struct scm_cookie scm; | |
1857 | bool fds_sent = false; | |
1858 | int max_level; | |
1859 | int data_len; | |
1860 | ||
1861 | wait_for_unix_gc(); | |
1862 | err = scm_send(sock, msg, &scm, false); | |
1863 | if (err < 0) | |
1864 | return err; | |
1865 | ||
1866 | err = -EOPNOTSUPP; | |
1867 | if (msg->msg_flags&MSG_OOB) | |
1868 | goto out_err; | |
1869 | ||
1870 | if (msg->msg_namelen) { | |
1871 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1872 | goto out_err; | |
1873 | } else { | |
1874 | err = -ENOTCONN; | |
1875 | other = unix_peer(sk); | |
1876 | if (!other) | |
1877 | goto out_err; | |
1878 | } | |
1879 | ||
1880 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1881 | goto pipe_err; | |
1882 | ||
1883 | while (sent < len) { | |
1884 | size = len - sent; | |
1885 | ||
1886 | /* Keep two messages in the pipe so it schedules better */ | |
1887 | size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); | |
1888 | ||
1889 | /* allow fallback to order-0 allocations */ | |
1890 | size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); | |
1891 | ||
1892 | data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); | |
1893 | ||
1894 | data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); | |
1895 | ||
1896 | skb = sock_alloc_send_pskb(sk, size - data_len, data_len, | |
1897 | msg->msg_flags & MSG_DONTWAIT, &err, | |
1898 | get_order(UNIX_SKB_FRAGS_SZ)); | |
1899 | if (!skb) | |
1900 | goto out_err; | |
1901 | ||
1902 | /* Only send the fds in the first buffer */ | |
1903 | err = unix_scm_to_skb(&scm, skb, !fds_sent); | |
1904 | if (err < 0) { | |
1905 | kfree_skb(skb); | |
1906 | goto out_err; | |
1907 | } | |
1908 | max_level = err + 1; | |
1909 | fds_sent = true; | |
1910 | ||
1911 | skb_put(skb, size - data_len); | |
1912 | skb->data_len = data_len; | |
1913 | skb->len = size; | |
1914 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); | |
1915 | if (err) { | |
1916 | kfree_skb(skb); | |
1917 | goto out_err; | |
1918 | } | |
1919 | ||
1920 | unix_state_lock(other); | |
1921 | ||
1922 | if (sock_flag(other, SOCK_DEAD) || | |
1923 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1924 | goto pipe_err_free; | |
1925 | ||
1926 | maybe_add_creds(skb, sock, other); | |
1927 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1928 | if (max_level > unix_sk(other)->recursion_level) | |
1929 | unix_sk(other)->recursion_level = max_level; | |
1930 | unix_state_unlock(other); | |
1931 | other->sk_data_ready(other); | |
1932 | sent += size; | |
1933 | } | |
1934 | ||
1935 | scm_destroy(&scm); | |
1936 | ||
1937 | return sent; | |
1938 | ||
1939 | pipe_err_free: | |
1940 | unix_state_unlock(other); | |
1941 | kfree_skb(skb); | |
1942 | pipe_err: | |
1943 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) | |
1944 | send_sig(SIGPIPE, current, 0); | |
1945 | err = -EPIPE; | |
1946 | out_err: | |
1947 | scm_destroy(&scm); | |
1948 | return sent ? : err; | |
1949 | } | |
1950 | ||
1951 | static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page, | |
1952 | int offset, size_t size, int flags) | |
1953 | { | |
1954 | int err; | |
1955 | bool send_sigpipe = false; | |
1956 | bool init_scm = true; | |
1957 | struct scm_cookie scm; | |
1958 | struct sock *other, *sk = socket->sk; | |
1959 | struct sk_buff *skb, *newskb = NULL, *tail = NULL; | |
1960 | ||
1961 | if (flags & MSG_OOB) | |
1962 | return -EOPNOTSUPP; | |
1963 | ||
1964 | other = unix_peer(sk); | |
1965 | if (!other || sk->sk_state != TCP_ESTABLISHED) | |
1966 | return -ENOTCONN; | |
1967 | ||
1968 | if (false) { | |
1969 | alloc_skb: | |
1970 | unix_state_unlock(other); | |
1971 | mutex_unlock(&unix_sk(other)->iolock); | |
1972 | newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT, | |
1973 | &err, 0); | |
1974 | if (!newskb) | |
1975 | goto err; | |
1976 | } | |
1977 | ||
1978 | /* we must acquire iolock as we modify already present | |
1979 | * skbs in the sk_receive_queue and mess with skb->len | |
1980 | */ | |
1981 | err = mutex_lock_interruptible(&unix_sk(other)->iolock); | |
1982 | if (err) { | |
1983 | err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS; | |
1984 | goto err; | |
1985 | } | |
1986 | ||
1987 | if (sk->sk_shutdown & SEND_SHUTDOWN) { | |
1988 | err = -EPIPE; | |
1989 | send_sigpipe = true; | |
1990 | goto err_unlock; | |
1991 | } | |
1992 | ||
1993 | unix_state_lock(other); | |
1994 | ||
1995 | if (sock_flag(other, SOCK_DEAD) || | |
1996 | other->sk_shutdown & RCV_SHUTDOWN) { | |
1997 | err = -EPIPE; | |
1998 | send_sigpipe = true; | |
1999 | goto err_state_unlock; | |
2000 | } | |
2001 | ||
2002 | if (init_scm) { | |
2003 | err = maybe_init_creds(&scm, socket, other); | |
2004 | if (err) | |
2005 | goto err_state_unlock; | |
2006 | init_scm = false; | |
2007 | } | |
2008 | ||
2009 | skb = skb_peek_tail(&other->sk_receive_queue); | |
2010 | if (tail && tail == skb) { | |
2011 | skb = newskb; | |
2012 | } else if (!skb || !unix_skb_scm_eq(skb, &scm)) { | |
2013 | if (newskb) { | |
2014 | skb = newskb; | |
2015 | } else { | |
2016 | tail = skb; | |
2017 | goto alloc_skb; | |
2018 | } | |
2019 | } else if (newskb) { | |
2020 | /* this is fast path, we don't necessarily need to | |
2021 | * call to kfree_skb even though with newskb == NULL | |
2022 | * this - does no harm | |
2023 | */ | |
2024 | consume_skb(newskb); | |
2025 | newskb = NULL; | |
2026 | } | |
2027 | ||
2028 | if (skb_append_pagefrags(skb, page, offset, size)) { | |
2029 | tail = skb; | |
2030 | goto alloc_skb; | |
2031 | } | |
2032 | ||
2033 | skb->len += size; | |
2034 | skb->data_len += size; | |
2035 | skb->truesize += size; | |
2036 | atomic_add(size, &sk->sk_wmem_alloc); | |
2037 | ||
2038 | if (newskb) { | |
2039 | err = unix_scm_to_skb(&scm, skb, false); | |
2040 | if (err) | |
2041 | goto err_state_unlock; | |
2042 | spin_lock(&other->sk_receive_queue.lock); | |
2043 | __skb_queue_tail(&other->sk_receive_queue, newskb); | |
2044 | spin_unlock(&other->sk_receive_queue.lock); | |
2045 | } | |
2046 | ||
2047 | unix_state_unlock(other); | |
2048 | mutex_unlock(&unix_sk(other)->iolock); | |
2049 | ||
2050 | other->sk_data_ready(other); | |
2051 | scm_destroy(&scm); | |
2052 | return size; | |
2053 | ||
2054 | err_state_unlock: | |
2055 | unix_state_unlock(other); | |
2056 | err_unlock: | |
2057 | mutex_unlock(&unix_sk(other)->iolock); | |
2058 | err: | |
2059 | kfree_skb(newskb); | |
2060 | if (send_sigpipe && !(flags & MSG_NOSIGNAL)) | |
2061 | send_sig(SIGPIPE, current, 0); | |
2062 | if (!init_scm) | |
2063 | scm_destroy(&scm); | |
2064 | return err; | |
2065 | } | |
2066 | ||
2067 | static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg, | |
2068 | size_t len) | |
2069 | { | |
2070 | int err; | |
2071 | struct sock *sk = sock->sk; | |
2072 | ||
2073 | err = sock_error(sk); | |
2074 | if (err) | |
2075 | return err; | |
2076 | ||
2077 | if (sk->sk_state != TCP_ESTABLISHED) | |
2078 | return -ENOTCONN; | |
2079 | ||
2080 | if (msg->msg_namelen) | |
2081 | msg->msg_namelen = 0; | |
2082 | ||
2083 | return unix_dgram_sendmsg(sock, msg, len); | |
2084 | } | |
2085 | ||
2086 | static int unix_seqpacket_recvmsg(struct socket *sock, struct msghdr *msg, | |
2087 | size_t size, int flags) | |
2088 | { | |
2089 | struct sock *sk = sock->sk; | |
2090 | ||
2091 | if (sk->sk_state != TCP_ESTABLISHED) | |
2092 | return -ENOTCONN; | |
2093 | ||
2094 | return unix_dgram_recvmsg(sock, msg, size, flags); | |
2095 | } | |
2096 | ||
2097 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) | |
2098 | { | |
2099 | struct unix_sock *u = unix_sk(sk); | |
2100 | ||
2101 | if (u->addr) { | |
2102 | msg->msg_namelen = u->addr->len; | |
2103 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
2104 | } | |
2105 | } | |
2106 | ||
2107 | static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, | |
2108 | size_t size, int flags) | |
2109 | { | |
2110 | struct scm_cookie scm; | |
2111 | struct sock *sk = sock->sk; | |
2112 | struct unix_sock *u = unix_sk(sk); | |
2113 | struct sk_buff *skb, *last; | |
2114 | long timeo; | |
2115 | int err; | |
2116 | int peeked, skip; | |
2117 | ||
2118 | err = -EOPNOTSUPP; | |
2119 | if (flags&MSG_OOB) | |
2120 | goto out; | |
2121 | ||
2122 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); | |
2123 | ||
2124 | do { | |
2125 | mutex_lock(&u->iolock); | |
2126 | ||
2127 | skip = sk_peek_offset(sk, flags); | |
2128 | skb = __skb_try_recv_datagram(sk, flags, NULL, &peeked, &skip, | |
2129 | &err, &last); | |
2130 | if (skb) | |
2131 | break; | |
2132 | ||
2133 | mutex_unlock(&u->iolock); | |
2134 | ||
2135 | if (err != -EAGAIN) | |
2136 | break; | |
2137 | } while (timeo && | |
2138 | !__skb_wait_for_more_packets(sk, &err, &timeo, last)); | |
2139 | ||
2140 | if (!skb) { /* implies iolock unlocked */ | |
2141 | unix_state_lock(sk); | |
2142 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
2143 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
2144 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
2145 | err = 0; | |
2146 | unix_state_unlock(sk); | |
2147 | goto out; | |
2148 | } | |
2149 | ||
2150 | if (wq_has_sleeper(&u->peer_wait)) | |
2151 | wake_up_interruptible_sync_poll(&u->peer_wait, | |
2152 | POLLOUT | POLLWRNORM | | |
2153 | POLLWRBAND); | |
2154 | ||
2155 | if (msg->msg_name) | |
2156 | unix_copy_addr(msg, skb->sk); | |
2157 | ||
2158 | if (size > skb->len - skip) | |
2159 | size = skb->len - skip; | |
2160 | else if (size < skb->len - skip) | |
2161 | msg->msg_flags |= MSG_TRUNC; | |
2162 | ||
2163 | err = skb_copy_datagram_msg(skb, skip, msg, size); | |
2164 | if (err) | |
2165 | goto out_free; | |
2166 | ||
2167 | if (sock_flag(sk, SOCK_RCVTSTAMP)) | |
2168 | __sock_recv_timestamp(msg, sk, skb); | |
2169 | ||
2170 | memset(&scm, 0, sizeof(scm)); | |
2171 | ||
2172 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); | |
2173 | unix_set_secdata(&scm, skb); | |
2174 | ||
2175 | if (!(flags & MSG_PEEK)) { | |
2176 | if (UNIXCB(skb).fp) | |
2177 | unix_detach_fds(&scm, skb); | |
2178 | ||
2179 | sk_peek_offset_bwd(sk, skb->len); | |
2180 | } else { | |
2181 | /* It is questionable: on PEEK we could: | |
2182 | - do not return fds - good, but too simple 8) | |
2183 | - return fds, and do not return them on read (old strategy, | |
2184 | apparently wrong) | |
2185 | - clone fds (I chose it for now, it is the most universal | |
2186 | solution) | |
2187 | ||
2188 | POSIX 1003.1g does not actually define this clearly | |
2189 | at all. POSIX 1003.1g doesn't define a lot of things | |
2190 | clearly however! | |
2191 | ||
2192 | */ | |
2193 | ||
2194 | sk_peek_offset_fwd(sk, size); | |
2195 | ||
2196 | if (UNIXCB(skb).fp) | |
2197 | scm.fp = scm_fp_dup(UNIXCB(skb).fp); | |
2198 | } | |
2199 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; | |
2200 | ||
2201 | scm_recv(sock, msg, &scm, flags); | |
2202 | ||
2203 | out_free: | |
2204 | skb_free_datagram(sk, skb); | |
2205 | mutex_unlock(&u->iolock); | |
2206 | out: | |
2207 | return err; | |
2208 | } | |
2209 | ||
2210 | /* | |
2211 | * Sleep until more data has arrived. But check for races.. | |
2212 | */ | |
2213 | static long unix_stream_data_wait(struct sock *sk, long timeo, | |
2214 | struct sk_buff *last, unsigned int last_len, | |
2215 | bool freezable) | |
2216 | { | |
2217 | struct sk_buff *tail; | |
2218 | DEFINE_WAIT(wait); | |
2219 | ||
2220 | unix_state_lock(sk); | |
2221 | ||
2222 | for (;;) { | |
2223 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); | |
2224 | ||
2225 | tail = skb_peek_tail(&sk->sk_receive_queue); | |
2226 | if (tail != last || | |
2227 | (tail && tail->len != last_len) || | |
2228 | sk->sk_err || | |
2229 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
2230 | signal_pending(current) || | |
2231 | !timeo) | |
2232 | break; | |
2233 | ||
2234 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); | |
2235 | unix_state_unlock(sk); | |
2236 | if (freezable) | |
2237 | timeo = freezable_schedule_timeout(timeo); | |
2238 | else | |
2239 | timeo = schedule_timeout(timeo); | |
2240 | unix_state_lock(sk); | |
2241 | ||
2242 | if (sock_flag(sk, SOCK_DEAD)) | |
2243 | break; | |
2244 | ||
2245 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); | |
2246 | } | |
2247 | ||
2248 | finish_wait(sk_sleep(sk), &wait); | |
2249 | unix_state_unlock(sk); | |
2250 | return timeo; | |
2251 | } | |
2252 | ||
2253 | static unsigned int unix_skb_len(const struct sk_buff *skb) | |
2254 | { | |
2255 | return skb->len - UNIXCB(skb).consumed; | |
2256 | } | |
2257 | ||
2258 | struct unix_stream_read_state { | |
2259 | int (*recv_actor)(struct sk_buff *, int, int, | |
2260 | struct unix_stream_read_state *); | |
2261 | struct socket *socket; | |
2262 | struct msghdr *msg; | |
2263 | struct pipe_inode_info *pipe; | |
2264 | size_t size; | |
2265 | int flags; | |
2266 | unsigned int splice_flags; | |
2267 | }; | |
2268 | ||
2269 | static int unix_stream_read_generic(struct unix_stream_read_state *state, | |
2270 | bool freezable) | |
2271 | { | |
2272 | struct scm_cookie scm; | |
2273 | struct socket *sock = state->socket; | |
2274 | struct sock *sk = sock->sk; | |
2275 | struct unix_sock *u = unix_sk(sk); | |
2276 | int copied = 0; | |
2277 | int flags = state->flags; | |
2278 | int noblock = flags & MSG_DONTWAIT; | |
2279 | bool check_creds = false; | |
2280 | int target; | |
2281 | int err = 0; | |
2282 | long timeo; | |
2283 | int skip; | |
2284 | size_t size = state->size; | |
2285 | unsigned int last_len; | |
2286 | ||
2287 | if (unlikely(sk->sk_state != TCP_ESTABLISHED)) { | |
2288 | err = -EINVAL; | |
2289 | goto out; | |
2290 | } | |
2291 | ||
2292 | if (unlikely(flags & MSG_OOB)) { | |
2293 | err = -EOPNOTSUPP; | |
2294 | goto out; | |
2295 | } | |
2296 | ||
2297 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, size); | |
2298 | timeo = sock_rcvtimeo(sk, noblock); | |
2299 | ||
2300 | memset(&scm, 0, sizeof(scm)); | |
2301 | ||
2302 | /* Lock the socket to prevent queue disordering | |
2303 | * while sleeps in memcpy_tomsg | |
2304 | */ | |
2305 | mutex_lock(&u->iolock); | |
2306 | ||
2307 | if (flags & MSG_PEEK) | |
2308 | skip = sk_peek_offset(sk, flags); | |
2309 | else | |
2310 | skip = 0; | |
2311 | ||
2312 | do { | |
2313 | int chunk; | |
2314 | bool drop_skb; | |
2315 | struct sk_buff *skb, *last; | |
2316 | ||
2317 | redo: | |
2318 | unix_state_lock(sk); | |
2319 | if (sock_flag(sk, SOCK_DEAD)) { | |
2320 | err = -ECONNRESET; | |
2321 | goto unlock; | |
2322 | } | |
2323 | last = skb = skb_peek(&sk->sk_receive_queue); | |
2324 | last_len = last ? last->len : 0; | |
2325 | again: | |
2326 | if (skb == NULL) { | |
2327 | unix_sk(sk)->recursion_level = 0; | |
2328 | if (copied >= target) | |
2329 | goto unlock; | |
2330 | ||
2331 | /* | |
2332 | * POSIX 1003.1g mandates this order. | |
2333 | */ | |
2334 | ||
2335 | err = sock_error(sk); | |
2336 | if (err) | |
2337 | goto unlock; | |
2338 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
2339 | goto unlock; | |
2340 | ||
2341 | unix_state_unlock(sk); | |
2342 | if (!timeo) { | |
2343 | err = -EAGAIN; | |
2344 | break; | |
2345 | } | |
2346 | ||
2347 | mutex_unlock(&u->iolock); | |
2348 | ||
2349 | timeo = unix_stream_data_wait(sk, timeo, last, | |
2350 | last_len, freezable); | |
2351 | ||
2352 | if (signal_pending(current)) { | |
2353 | err = sock_intr_errno(timeo); | |
2354 | scm_destroy(&scm); | |
2355 | goto out; | |
2356 | } | |
2357 | ||
2358 | mutex_lock(&u->iolock); | |
2359 | goto redo; | |
2360 | unlock: | |
2361 | unix_state_unlock(sk); | |
2362 | break; | |
2363 | } | |
2364 | ||
2365 | while (skip >= unix_skb_len(skb)) { | |
2366 | skip -= unix_skb_len(skb); | |
2367 | last = skb; | |
2368 | last_len = skb->len; | |
2369 | skb = skb_peek_next(skb, &sk->sk_receive_queue); | |
2370 | if (!skb) | |
2371 | goto again; | |
2372 | } | |
2373 | ||
2374 | unix_state_unlock(sk); | |
2375 | ||
2376 | if (check_creds) { | |
2377 | /* Never glue messages from different writers */ | |
2378 | if (!unix_skb_scm_eq(skb, &scm)) | |
2379 | break; | |
2380 | } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { | |
2381 | /* Copy credentials */ | |
2382 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); | |
2383 | unix_set_secdata(&scm, skb); | |
2384 | check_creds = true; | |
2385 | } | |
2386 | ||
2387 | /* Copy address just once */ | |
2388 | if (state->msg && state->msg->msg_name) { | |
2389 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, | |
2390 | state->msg->msg_name); | |
2391 | unix_copy_addr(state->msg, skb->sk); | |
2392 | sunaddr = NULL; | |
2393 | } | |
2394 | ||
2395 | chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size); | |
2396 | skb_get(skb); | |
2397 | chunk = state->recv_actor(skb, skip, chunk, state); | |
2398 | drop_skb = !unix_skb_len(skb); | |
2399 | /* skb is only safe to use if !drop_skb */ | |
2400 | consume_skb(skb); | |
2401 | if (chunk < 0) { | |
2402 | if (copied == 0) | |
2403 | copied = -EFAULT; | |
2404 | break; | |
2405 | } | |
2406 | copied += chunk; | |
2407 | size -= chunk; | |
2408 | ||
2409 | if (drop_skb) { | |
2410 | /* the skb was touched by a concurrent reader; | |
2411 | * we should not expect anything from this skb | |
2412 | * anymore and assume it invalid - we can be | |
2413 | * sure it was dropped from the socket queue | |
2414 | * | |
2415 | * let's report a short read | |
2416 | */ | |
2417 | err = 0; | |
2418 | break; | |
2419 | } | |
2420 | ||
2421 | /* Mark read part of skb as used */ | |
2422 | if (!(flags & MSG_PEEK)) { | |
2423 | UNIXCB(skb).consumed += chunk; | |
2424 | ||
2425 | sk_peek_offset_bwd(sk, chunk); | |
2426 | ||
2427 | if (UNIXCB(skb).fp) | |
2428 | unix_detach_fds(&scm, skb); | |
2429 | ||
2430 | if (unix_skb_len(skb)) | |
2431 | break; | |
2432 | ||
2433 | skb_unlink(skb, &sk->sk_receive_queue); | |
2434 | consume_skb(skb); | |
2435 | ||
2436 | if (scm.fp) | |
2437 | break; | |
2438 | } else { | |
2439 | /* It is questionable, see note in unix_dgram_recvmsg. | |
2440 | */ | |
2441 | if (UNIXCB(skb).fp) | |
2442 | scm.fp = scm_fp_dup(UNIXCB(skb).fp); | |
2443 | ||
2444 | sk_peek_offset_fwd(sk, chunk); | |
2445 | ||
2446 | if (UNIXCB(skb).fp) | |
2447 | break; | |
2448 | ||
2449 | skip = 0; | |
2450 | last = skb; | |
2451 | last_len = skb->len; | |
2452 | unix_state_lock(sk); | |
2453 | skb = skb_peek_next(skb, &sk->sk_receive_queue); | |
2454 | if (skb) | |
2455 | goto again; | |
2456 | unix_state_unlock(sk); | |
2457 | break; | |
2458 | } | |
2459 | } while (size); | |
2460 | ||
2461 | mutex_unlock(&u->iolock); | |
2462 | if (state->msg) | |
2463 | scm_recv(sock, state->msg, &scm, flags); | |
2464 | else | |
2465 | scm_destroy(&scm); | |
2466 | out: | |
2467 | return copied ? : err; | |
2468 | } | |
2469 | ||
2470 | static int unix_stream_read_actor(struct sk_buff *skb, | |
2471 | int skip, int chunk, | |
2472 | struct unix_stream_read_state *state) | |
2473 | { | |
2474 | int ret; | |
2475 | ||
2476 | ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip, | |
2477 | state->msg, chunk); | |
2478 | return ret ?: chunk; | |
2479 | } | |
2480 | ||
2481 | static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, | |
2482 | size_t size, int flags) | |
2483 | { | |
2484 | struct unix_stream_read_state state = { | |
2485 | .recv_actor = unix_stream_read_actor, | |
2486 | .socket = sock, | |
2487 | .msg = msg, | |
2488 | .size = size, | |
2489 | .flags = flags | |
2490 | }; | |
2491 | ||
2492 | return unix_stream_read_generic(&state, true); | |
2493 | } | |
2494 | ||
2495 | static int unix_stream_splice_actor(struct sk_buff *skb, | |
2496 | int skip, int chunk, | |
2497 | struct unix_stream_read_state *state) | |
2498 | { | |
2499 | return skb_splice_bits(skb, state->socket->sk, | |
2500 | UNIXCB(skb).consumed + skip, | |
2501 | state->pipe, chunk, state->splice_flags); | |
2502 | } | |
2503 | ||
2504 | static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos, | |
2505 | struct pipe_inode_info *pipe, | |
2506 | size_t size, unsigned int flags) | |
2507 | { | |
2508 | struct unix_stream_read_state state = { | |
2509 | .recv_actor = unix_stream_splice_actor, | |
2510 | .socket = sock, | |
2511 | .pipe = pipe, | |
2512 | .size = size, | |
2513 | .splice_flags = flags, | |
2514 | }; | |
2515 | ||
2516 | if (unlikely(*ppos)) | |
2517 | return -ESPIPE; | |
2518 | ||
2519 | if (sock->file->f_flags & O_NONBLOCK || | |
2520 | flags & SPLICE_F_NONBLOCK) | |
2521 | state.flags = MSG_DONTWAIT; | |
2522 | ||
2523 | return unix_stream_read_generic(&state, false); | |
2524 | } | |
2525 | ||
2526 | static int unix_shutdown(struct socket *sock, int mode) | |
2527 | { | |
2528 | struct sock *sk = sock->sk; | |
2529 | struct sock *other; | |
2530 | ||
2531 | if (mode < SHUT_RD || mode > SHUT_RDWR) | |
2532 | return -EINVAL; | |
2533 | /* This maps: | |
2534 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2535 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2536 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2537 | */ | |
2538 | ++mode; | |
2539 | ||
2540 | unix_state_lock(sk); | |
2541 | sk->sk_shutdown |= mode; | |
2542 | other = unix_peer(sk); | |
2543 | if (other) | |
2544 | sock_hold(other); | |
2545 | unix_state_unlock(sk); | |
2546 | sk->sk_state_change(sk); | |
2547 | ||
2548 | if (other && | |
2549 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2550 | ||
2551 | int peer_mode = 0; | |
2552 | ||
2553 | if (mode&RCV_SHUTDOWN) | |
2554 | peer_mode |= SEND_SHUTDOWN; | |
2555 | if (mode&SEND_SHUTDOWN) | |
2556 | peer_mode |= RCV_SHUTDOWN; | |
2557 | unix_state_lock(other); | |
2558 | other->sk_shutdown |= peer_mode; | |
2559 | unix_state_unlock(other); | |
2560 | other->sk_state_change(other); | |
2561 | if (peer_mode == SHUTDOWN_MASK) | |
2562 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2563 | else if (peer_mode & RCV_SHUTDOWN) | |
2564 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
2565 | } | |
2566 | if (other) | |
2567 | sock_put(other); | |
2568 | ||
2569 | return 0; | |
2570 | } | |
2571 | ||
2572 | long unix_inq_len(struct sock *sk) | |
2573 | { | |
2574 | struct sk_buff *skb; | |
2575 | long amount = 0; | |
2576 | ||
2577 | if (sk->sk_state == TCP_LISTEN) | |
2578 | return -EINVAL; | |
2579 | ||
2580 | spin_lock(&sk->sk_receive_queue.lock); | |
2581 | if (sk->sk_type == SOCK_STREAM || | |
2582 | sk->sk_type == SOCK_SEQPACKET) { | |
2583 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
2584 | amount += unix_skb_len(skb); | |
2585 | } else { | |
2586 | skb = skb_peek(&sk->sk_receive_queue); | |
2587 | if (skb) | |
2588 | amount = skb->len; | |
2589 | } | |
2590 | spin_unlock(&sk->sk_receive_queue.lock); | |
2591 | ||
2592 | return amount; | |
2593 | } | |
2594 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2595 | ||
2596 | long unix_outq_len(struct sock *sk) | |
2597 | { | |
2598 | return sk_wmem_alloc_get(sk); | |
2599 | } | |
2600 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2601 | ||
2602 | static int unix_open_file(struct sock *sk) | |
2603 | { | |
2604 | struct path path; | |
2605 | struct file *f; | |
2606 | int fd; | |
2607 | ||
2608 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) | |
2609 | return -EPERM; | |
2610 | ||
2611 | unix_state_lock(sk); | |
2612 | path = unix_sk(sk)->path; | |
2613 | if (!path.dentry) { | |
2614 | unix_state_unlock(sk); | |
2615 | return -ENOENT; | |
2616 | } | |
2617 | ||
2618 | path_get(&path); | |
2619 | unix_state_unlock(sk); | |
2620 | ||
2621 | fd = get_unused_fd_flags(O_CLOEXEC); | |
2622 | if (fd < 0) | |
2623 | goto out; | |
2624 | ||
2625 | f = dentry_open(&path, O_PATH, current_cred()); | |
2626 | if (IS_ERR(f)) { | |
2627 | put_unused_fd(fd); | |
2628 | fd = PTR_ERR(f); | |
2629 | goto out; | |
2630 | } | |
2631 | ||
2632 | fd_install(fd, f); | |
2633 | out: | |
2634 | path_put(&path); | |
2635 | ||
2636 | return fd; | |
2637 | } | |
2638 | ||
2639 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
2640 | { | |
2641 | struct sock *sk = sock->sk; | |
2642 | long amount = 0; | |
2643 | int err; | |
2644 | ||
2645 | switch (cmd) { | |
2646 | case SIOCOUTQ: | |
2647 | amount = unix_outq_len(sk); | |
2648 | err = put_user(amount, (int __user *)arg); | |
2649 | break; | |
2650 | case SIOCINQ: | |
2651 | amount = unix_inq_len(sk); | |
2652 | if (amount < 0) | |
2653 | err = amount; | |
2654 | else | |
2655 | err = put_user(amount, (int __user *)arg); | |
2656 | break; | |
2657 | case SIOCUNIXFILE: | |
2658 | err = unix_open_file(sk); | |
2659 | break; | |
2660 | default: | |
2661 | err = -ENOIOCTLCMD; | |
2662 | break; | |
2663 | } | |
2664 | return err; | |
2665 | } | |
2666 | ||
2667 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) | |
2668 | { | |
2669 | struct sock *sk = sock->sk; | |
2670 | unsigned int mask; | |
2671 | ||
2672 | sock_poll_wait(file, sk_sleep(sk), wait); | |
2673 | mask = 0; | |
2674 | ||
2675 | /* exceptional events? */ | |
2676 | if (sk->sk_err) | |
2677 | mask |= POLLERR; | |
2678 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2679 | mask |= POLLHUP; | |
2680 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
2681 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; | |
2682 | ||
2683 | /* readable? */ | |
2684 | if (!skb_queue_empty(&sk->sk_receive_queue)) | |
2685 | mask |= POLLIN | POLLRDNORM; | |
2686 | ||
2687 | /* Connection-based need to check for termination and startup */ | |
2688 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && | |
2689 | sk->sk_state == TCP_CLOSE) | |
2690 | mask |= POLLHUP; | |
2691 | ||
2692 | /* | |
2693 | * we set writable also when the other side has shut down the | |
2694 | * connection. This prevents stuck sockets. | |
2695 | */ | |
2696 | if (unix_writable(sk)) | |
2697 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2698 | ||
2699 | return mask; | |
2700 | } | |
2701 | ||
2702 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, | |
2703 | poll_table *wait) | |
2704 | { | |
2705 | struct sock *sk = sock->sk, *other; | |
2706 | unsigned int mask, writable; | |
2707 | ||
2708 | sock_poll_wait(file, sk_sleep(sk), wait); | |
2709 | mask = 0; | |
2710 | ||
2711 | /* exceptional events? */ | |
2712 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
2713 | mask |= POLLERR | | |
2714 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0); | |
2715 | ||
2716 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
2717 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; | |
2718 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2719 | mask |= POLLHUP; | |
2720 | ||
2721 | /* readable? */ | |
2722 | if (!skb_queue_empty(&sk->sk_receive_queue)) | |
2723 | mask |= POLLIN | POLLRDNORM; | |
2724 | ||
2725 | /* Connection-based need to check for termination and startup */ | |
2726 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2727 | if (sk->sk_state == TCP_CLOSE) | |
2728 | mask |= POLLHUP; | |
2729 | /* connection hasn't started yet? */ | |
2730 | if (sk->sk_state == TCP_SYN_SENT) | |
2731 | return mask; | |
2732 | } | |
2733 | ||
2734 | /* No write status requested, avoid expensive OUT tests. */ | |
2735 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) | |
2736 | return mask; | |
2737 | ||
2738 | writable = unix_writable(sk); | |
2739 | if (writable) { | |
2740 | unix_state_lock(sk); | |
2741 | ||
2742 | other = unix_peer(sk); | |
2743 | if (other && unix_peer(other) != sk && | |
2744 | unix_recvq_full(other) && | |
2745 | unix_dgram_peer_wake_me(sk, other)) | |
2746 | writable = 0; | |
2747 | ||
2748 | unix_state_unlock(sk); | |
2749 | } | |
2750 | ||
2751 | if (writable) | |
2752 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2753 | else | |
2754 | sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
2755 | ||
2756 | return mask; | |
2757 | } | |
2758 | ||
2759 | #ifdef CONFIG_PROC_FS | |
2760 | ||
2761 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) | |
2762 | ||
2763 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
2764 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) | |
2765 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) | |
2766 | ||
2767 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) | |
2768 | { | |
2769 | unsigned long offset = get_offset(*pos); | |
2770 | unsigned long bucket = get_bucket(*pos); | |
2771 | struct sock *sk; | |
2772 | unsigned long count = 0; | |
2773 | ||
2774 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { | |
2775 | if (sock_net(sk) != seq_file_net(seq)) | |
2776 | continue; | |
2777 | if (++count == offset) | |
2778 | break; | |
2779 | } | |
2780 | ||
2781 | return sk; | |
2782 | } | |
2783 | ||
2784 | static struct sock *unix_next_socket(struct seq_file *seq, | |
2785 | struct sock *sk, | |
2786 | loff_t *pos) | |
2787 | { | |
2788 | unsigned long bucket; | |
2789 | ||
2790 | while (sk > (struct sock *)SEQ_START_TOKEN) { | |
2791 | sk = sk_next(sk); | |
2792 | if (!sk) | |
2793 | goto next_bucket; | |
2794 | if (sock_net(sk) == seq_file_net(seq)) | |
2795 | return sk; | |
2796 | } | |
2797 | ||
2798 | do { | |
2799 | sk = unix_from_bucket(seq, pos); | |
2800 | if (sk) | |
2801 | return sk; | |
2802 | ||
2803 | next_bucket: | |
2804 | bucket = get_bucket(*pos) + 1; | |
2805 | *pos = set_bucket_offset(bucket, 1); | |
2806 | } while (bucket < ARRAY_SIZE(unix_socket_table)); | |
2807 | ||
2808 | return NULL; | |
2809 | } | |
2810 | ||
2811 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) | |
2812 | __acquires(unix_table_lock) | |
2813 | { | |
2814 | spin_lock(&unix_table_lock); | |
2815 | ||
2816 | if (!*pos) | |
2817 | return SEQ_START_TOKEN; | |
2818 | ||
2819 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) | |
2820 | return NULL; | |
2821 | ||
2822 | return unix_next_socket(seq, NULL, pos); | |
2823 | } | |
2824 | ||
2825 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2826 | { | |
2827 | ++*pos; | |
2828 | return unix_next_socket(seq, v, pos); | |
2829 | } | |
2830 | ||
2831 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
2832 | __releases(unix_table_lock) | |
2833 | { | |
2834 | spin_unlock(&unix_table_lock); | |
2835 | } | |
2836 | ||
2837 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2838 | { | |
2839 | ||
2840 | if (v == SEQ_START_TOKEN) | |
2841 | seq_puts(seq, "Num RefCount Protocol Flags Type St " | |
2842 | "Inode Path\n"); | |
2843 | else { | |
2844 | struct sock *s = v; | |
2845 | struct unix_sock *u = unix_sk(s); | |
2846 | unix_state_lock(s); | |
2847 | ||
2848 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", | |
2849 | s, | |
2850 | atomic_read(&s->sk_refcnt), | |
2851 | 0, | |
2852 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2853 | s->sk_type, | |
2854 | s->sk_socket ? | |
2855 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2856 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2857 | sock_i_ino(s)); | |
2858 | ||
2859 | if (u->addr) { | |
2860 | int i, len; | |
2861 | seq_putc(seq, ' '); | |
2862 | ||
2863 | i = 0; | |
2864 | len = u->addr->len - sizeof(short); | |
2865 | if (!UNIX_ABSTRACT(s)) | |
2866 | len--; | |
2867 | else { | |
2868 | seq_putc(seq, '@'); | |
2869 | i++; | |
2870 | } | |
2871 | for ( ; i < len; i++) | |
2872 | seq_putc(seq, u->addr->name->sun_path[i] ?: | |
2873 | '@'); | |
2874 | } | |
2875 | unix_state_unlock(s); | |
2876 | seq_putc(seq, '\n'); | |
2877 | } | |
2878 | ||
2879 | return 0; | |
2880 | } | |
2881 | ||
2882 | static const struct seq_operations unix_seq_ops = { | |
2883 | .start = unix_seq_start, | |
2884 | .next = unix_seq_next, | |
2885 | .stop = unix_seq_stop, | |
2886 | .show = unix_seq_show, | |
2887 | }; | |
2888 | ||
2889 | static int unix_seq_open(struct inode *inode, struct file *file) | |
2890 | { | |
2891 | return seq_open_net(inode, file, &unix_seq_ops, | |
2892 | sizeof(struct seq_net_private)); | |
2893 | } | |
2894 | ||
2895 | static const struct file_operations unix_seq_fops = { | |
2896 | .owner = THIS_MODULE, | |
2897 | .open = unix_seq_open, | |
2898 | .read = seq_read, | |
2899 | .llseek = seq_lseek, | |
2900 | .release = seq_release_net, | |
2901 | }; | |
2902 | ||
2903 | #endif | |
2904 | ||
2905 | static const struct net_proto_family unix_family_ops = { | |
2906 | .family = PF_UNIX, | |
2907 | .create = unix_create, | |
2908 | .owner = THIS_MODULE, | |
2909 | }; | |
2910 | ||
2911 | ||
2912 | static int __net_init unix_net_init(struct net *net) | |
2913 | { | |
2914 | int error = -ENOMEM; | |
2915 | ||
2916 | net->unx.sysctl_max_dgram_qlen = 10; | |
2917 | if (unix_sysctl_register(net)) | |
2918 | goto out; | |
2919 | ||
2920 | #ifdef CONFIG_PROC_FS | |
2921 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { | |
2922 | unix_sysctl_unregister(net); | |
2923 | goto out; | |
2924 | } | |
2925 | #endif | |
2926 | error = 0; | |
2927 | out: | |
2928 | return error; | |
2929 | } | |
2930 | ||
2931 | static void __net_exit unix_net_exit(struct net *net) | |
2932 | { | |
2933 | unix_sysctl_unregister(net); | |
2934 | remove_proc_entry("unix", net->proc_net); | |
2935 | } | |
2936 | ||
2937 | static struct pernet_operations unix_net_ops = { | |
2938 | .init = unix_net_init, | |
2939 | .exit = unix_net_exit, | |
2940 | }; | |
2941 | ||
2942 | static int __init af_unix_init(void) | |
2943 | { | |
2944 | int rc = -1; | |
2945 | ||
2946 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); | |
2947 | ||
2948 | rc = proto_register(&unix_proto, 1); | |
2949 | if (rc != 0) { | |
2950 | pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); | |
2951 | goto out; | |
2952 | } | |
2953 | ||
2954 | sock_register(&unix_family_ops); | |
2955 | register_pernet_subsys(&unix_net_ops); | |
2956 | out: | |
2957 | return rc; | |
2958 | } | |
2959 | ||
2960 | static void __exit af_unix_exit(void) | |
2961 | { | |
2962 | sock_unregister(PF_UNIX); | |
2963 | proto_unregister(&unix_proto); | |
2964 | unregister_pernet_subsys(&unix_net_ops); | |
2965 | } | |
2966 | ||
2967 | /* Earlier than device_initcall() so that other drivers invoking | |
2968 | request_module() don't end up in a loop when modprobe tries | |
2969 | to use a UNIX socket. But later than subsys_initcall() because | |
2970 | we depend on stuff initialised there */ | |
2971 | fs_initcall(af_unix_init); | |
2972 | module_exit(af_unix_exit); | |
2973 | ||
2974 | MODULE_LICENSE("GPL"); | |
2975 | MODULE_ALIAS_NETPROTO(PF_UNIX); |