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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NET4: Implementation of BSD Unix domain sockets. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
1da177e4 LT |
11 | * Fixes: |
12 | * Linus Torvalds : Assorted bug cures. | |
13 | * Niibe Yutaka : async I/O support. | |
14 | * Carsten Paeth : PF_UNIX check, address fixes. | |
15 | * Alan Cox : Limit size of allocated blocks. | |
16 | * Alan Cox : Fixed the stupid socketpair bug. | |
17 | * Alan Cox : BSD compatibility fine tuning. | |
18 | * Alan Cox : Fixed a bug in connect when interrupted. | |
19 | * Alan Cox : Sorted out a proper draft version of | |
20 | * file descriptor passing hacked up from | |
21 | * Mike Shaver's work. | |
22 | * Marty Leisner : Fixes to fd passing | |
23 | * Nick Nevin : recvmsg bugfix. | |
24 | * Alan Cox : Started proper garbage collector | |
25 | * Heiko EiBfeldt : Missing verify_area check | |
26 | * Alan Cox : Started POSIXisms | |
27 | * Andreas Schwab : Replace inode by dentry for proper | |
28 | * reference counting | |
29 | * Kirk Petersen : Made this a module | |
30 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. | |
31 | * Lots of bug fixes. | |
32 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces | |
33 | * by above two patches. | |
34 | * Andrea Arcangeli : If possible we block in connect(2) | |
35 | * if the max backlog of the listen socket | |
36 | * is been reached. This won't break | |
37 | * old apps and it will avoid huge amount | |
38 | * of socks hashed (this for unix_gc() | |
39 | * performances reasons). | |
40 | * Security fix that limits the max | |
41 | * number of socks to 2*max_files and | |
42 | * the number of skb queueable in the | |
43 | * dgram receiver. | |
44 | * Artur Skawina : Hash function optimizations | |
45 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) | |
46 | * Malcolm Beattie : Set peercred for socketpair | |
47 | * Michal Ostrowski : Module initialization cleanup. | |
48 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, | |
49 | * the core infrastructure is doing that | |
50 | * for all net proto families now (2.5.69+) | |
51 | * | |
52 | * | |
53 | * Known differences from reference BSD that was tested: | |
54 | * | |
55 | * [TO FIX] | |
56 | * ECONNREFUSED is not returned from one end of a connected() socket to the | |
57 | * other the moment one end closes. | |
58 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark | |
59 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). | |
60 | * [NOT TO FIX] | |
61 | * accept() returns a path name even if the connecting socket has closed | |
62 | * in the meantime (BSD loses the path and gives up). | |
63 | * accept() returns 0 length path for an unbound connector. BSD returns 16 | |
64 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) | |
65 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. | |
66 | * BSD af_unix apparently has connect forgetting to block properly. | |
67 | * (need to check this with the POSIX spec in detail) | |
68 | * | |
69 | * Differences from 2.0.0-11-... (ANK) | |
70 | * Bug fixes and improvements. | |
71 | * - client shutdown killed server socket. | |
72 | * - removed all useless cli/sti pairs. | |
73 | * | |
74 | * Semantic changes/extensions. | |
75 | * - generic control message passing. | |
76 | * - SCM_CREDENTIALS control message. | |
77 | * - "Abstract" (not FS based) socket bindings. | |
78 | * Abstract names are sequences of bytes (not zero terminated) | |
79 | * started by 0, so that this name space does not intersect | |
80 | * with BSD names. | |
81 | */ | |
82 | ||
83 | #include <linux/module.h> | |
1da177e4 | 84 | #include <linux/kernel.h> |
1da177e4 LT |
85 | #include <linux/signal.h> |
86 | #include <linux/sched.h> | |
87 | #include <linux/errno.h> | |
88 | #include <linux/string.h> | |
89 | #include <linux/stat.h> | |
90 | #include <linux/dcache.h> | |
91 | #include <linux/namei.h> | |
92 | #include <linux/socket.h> | |
93 | #include <linux/un.h> | |
94 | #include <linux/fcntl.h> | |
95 | #include <linux/termios.h> | |
96 | #include <linux/sockios.h> | |
97 | #include <linux/net.h> | |
98 | #include <linux/in.h> | |
99 | #include <linux/fs.h> | |
100 | #include <linux/slab.h> | |
101 | #include <asm/uaccess.h> | |
102 | #include <linux/skbuff.h> | |
103 | #include <linux/netdevice.h> | |
457c4cbc | 104 | #include <net/net_namespace.h> |
1da177e4 | 105 | #include <net/sock.h> |
c752f073 | 106 | #include <net/tcp_states.h> |
1da177e4 LT |
107 | #include <net/af_unix.h> |
108 | #include <linux/proc_fs.h> | |
109 | #include <linux/seq_file.h> | |
110 | #include <net/scm.h> | |
111 | #include <linux/init.h> | |
112 | #include <linux/poll.h> | |
1da177e4 LT |
113 | #include <linux/rtnetlink.h> |
114 | #include <linux/mount.h> | |
115 | #include <net/checksum.h> | |
116 | #include <linux/security.h> | |
117 | ||
7123aaa3 | 118 | struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; |
fa7ff56f PE |
119 | EXPORT_SYMBOL_GPL(unix_socket_table); |
120 | DEFINE_SPINLOCK(unix_table_lock); | |
121 | EXPORT_SYMBOL_GPL(unix_table_lock); | |
518de9b3 | 122 | static atomic_long_t unix_nr_socks; |
1da177e4 | 123 | |
1da177e4 | 124 | |
7123aaa3 ED |
125 | static struct hlist_head *unix_sockets_unbound(void *addr) |
126 | { | |
127 | unsigned long hash = (unsigned long)addr; | |
128 | ||
129 | hash ^= hash >> 16; | |
130 | hash ^= hash >> 8; | |
131 | hash %= UNIX_HASH_SIZE; | |
132 | return &unix_socket_table[UNIX_HASH_SIZE + hash]; | |
133 | } | |
134 | ||
135 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE) | |
1da177e4 | 136 | |
877ce7c1 | 137 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 138 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 139 | { |
dc49c1f9 | 140 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
877ce7c1 CZ |
141 | } |
142 | ||
143 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
144 | { | |
dc49c1f9 | 145 | scm->secid = *UNIXSID(skb); |
877ce7c1 CZ |
146 | } |
147 | #else | |
dc49c1f9 | 148 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
149 | { } |
150 | ||
151 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
152 | { } | |
153 | #endif /* CONFIG_SECURITY_NETWORK */ | |
154 | ||
1da177e4 LT |
155 | /* |
156 | * SMP locking strategy: | |
fbe9cc4a | 157 | * hash table is protected with spinlock unix_table_lock |
663717f6 | 158 | * each socket state is protected by separate spin lock. |
1da177e4 LT |
159 | */ |
160 | ||
95c96174 | 161 | static inline unsigned int unix_hash_fold(__wsum n) |
1da177e4 | 162 | { |
95c96174 ED |
163 | unsigned int hash = (__force unsigned int)n; |
164 | ||
1da177e4 LT |
165 | hash ^= hash>>16; |
166 | hash ^= hash>>8; | |
167 | return hash&(UNIX_HASH_SIZE-1); | |
168 | } | |
169 | ||
170 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
171 | ||
172 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
173 | { | |
174 | return unix_peer(osk) == sk; | |
175 | } | |
176 | ||
177 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
178 | { | |
6eba6a37 | 179 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
180 | } |
181 | ||
3c73419c RW |
182 | static inline int unix_recvq_full(struct sock const *sk) |
183 | { | |
184 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
185 | } | |
186 | ||
fa7ff56f | 187 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
188 | { |
189 | struct sock *peer; | |
190 | ||
1c92b4e5 | 191 | unix_state_lock(s); |
1da177e4 LT |
192 | peer = unix_peer(s); |
193 | if (peer) | |
194 | sock_hold(peer); | |
1c92b4e5 | 195 | unix_state_unlock(s); |
1da177e4 LT |
196 | return peer; |
197 | } | |
fa7ff56f | 198 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 LT |
199 | |
200 | static inline void unix_release_addr(struct unix_address *addr) | |
201 | { | |
202 | if (atomic_dec_and_test(&addr->refcnt)) | |
203 | kfree(addr); | |
204 | } | |
205 | ||
206 | /* | |
207 | * Check unix socket name: | |
208 | * - should be not zero length. | |
209 | * - if started by not zero, should be NULL terminated (FS object) | |
210 | * - if started by zero, it is abstract name. | |
211 | */ | |
ac7bfa62 | 212 | |
95c96174 | 213 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
1da177e4 LT |
214 | { |
215 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
216 | return -EINVAL; | |
217 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
218 | return -EINVAL; | |
219 | if (sunaddr->sun_path[0]) { | |
220 | /* | |
221 | * This may look like an off by one error but it is a bit more | |
222 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
25985edc | 223 | * sun_path[108] doesn't as such exist. However in kernel space |
1da177e4 LT |
224 | * we are guaranteed that it is a valid memory location in our |
225 | * kernel address buffer. | |
226 | */ | |
e27dfcea | 227 | ((char *)sunaddr)[len] = 0; |
1da177e4 LT |
228 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
229 | return len; | |
230 | } | |
231 | ||
07f0757a | 232 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
1da177e4 LT |
233 | return len; |
234 | } | |
235 | ||
236 | static void __unix_remove_socket(struct sock *sk) | |
237 | { | |
238 | sk_del_node_init(sk); | |
239 | } | |
240 | ||
241 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
242 | { | |
547b792c | 243 | WARN_ON(!sk_unhashed(sk)); |
1da177e4 LT |
244 | sk_add_node(sk, list); |
245 | } | |
246 | ||
247 | static inline void unix_remove_socket(struct sock *sk) | |
248 | { | |
fbe9cc4a | 249 | spin_lock(&unix_table_lock); |
1da177e4 | 250 | __unix_remove_socket(sk); |
fbe9cc4a | 251 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
252 | } |
253 | ||
254 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
255 | { | |
fbe9cc4a | 256 | spin_lock(&unix_table_lock); |
1da177e4 | 257 | __unix_insert_socket(list, sk); |
fbe9cc4a | 258 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
259 | } |
260 | ||
097e66c5 DL |
261 | static struct sock *__unix_find_socket_byname(struct net *net, |
262 | struct sockaddr_un *sunname, | |
95c96174 | 263 | int len, int type, unsigned int hash) |
1da177e4 LT |
264 | { |
265 | struct sock *s; | |
1da177e4 | 266 | |
b67bfe0d | 267 | sk_for_each(s, &unix_socket_table[hash ^ type]) { |
1da177e4 LT |
268 | struct unix_sock *u = unix_sk(s); |
269 | ||
878628fb | 270 | if (!net_eq(sock_net(s), net)) |
097e66c5 DL |
271 | continue; |
272 | ||
1da177e4 LT |
273 | if (u->addr->len == len && |
274 | !memcmp(u->addr->name, sunname, len)) | |
275 | goto found; | |
276 | } | |
277 | s = NULL; | |
278 | found: | |
279 | return s; | |
280 | } | |
281 | ||
097e66c5 DL |
282 | static inline struct sock *unix_find_socket_byname(struct net *net, |
283 | struct sockaddr_un *sunname, | |
1da177e4 | 284 | int len, int type, |
95c96174 | 285 | unsigned int hash) |
1da177e4 LT |
286 | { |
287 | struct sock *s; | |
288 | ||
fbe9cc4a | 289 | spin_lock(&unix_table_lock); |
097e66c5 | 290 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
291 | if (s) |
292 | sock_hold(s); | |
fbe9cc4a | 293 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
294 | return s; |
295 | } | |
296 | ||
6616f788 | 297 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 LT |
298 | { |
299 | struct sock *s; | |
1da177e4 | 300 | |
fbe9cc4a | 301 | spin_lock(&unix_table_lock); |
b67bfe0d | 302 | sk_for_each(s, |
1da177e4 | 303 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
40ffe67d | 304 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 305 | |
6eba6a37 | 306 | if (dentry && dentry->d_inode == i) { |
1da177e4 LT |
307 | sock_hold(s); |
308 | goto found; | |
309 | } | |
310 | } | |
311 | s = NULL; | |
312 | found: | |
fbe9cc4a | 313 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
314 | return s; |
315 | } | |
316 | ||
317 | static inline int unix_writable(struct sock *sk) | |
318 | { | |
319 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
320 | } | |
321 | ||
322 | static void unix_write_space(struct sock *sk) | |
323 | { | |
43815482 ED |
324 | struct socket_wq *wq; |
325 | ||
326 | rcu_read_lock(); | |
1da177e4 | 327 | if (unix_writable(sk)) { |
43815482 ED |
328 | wq = rcu_dereference(sk->sk_wq); |
329 | if (wq_has_sleeper(wq)) | |
67426b75 ED |
330 | wake_up_interruptible_sync_poll(&wq->wait, |
331 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
8d8ad9d7 | 332 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 333 | } |
43815482 | 334 | rcu_read_unlock(); |
1da177e4 LT |
335 | } |
336 | ||
337 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
338 | * queue of packets arrived from previous peer. First, it allows to do | |
339 | * flow control based only on wmem_alloc; second, sk connected to peer | |
340 | * may receive messages only from that peer. */ | |
341 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
342 | { | |
b03efcfb | 343 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
344 | skb_queue_purge(&sk->sk_receive_queue); |
345 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
346 | ||
347 | /* If one link of bidirectional dgram pipe is disconnected, | |
348 | * we signal error. Messages are lost. Do not make this, | |
349 | * when peer was not connected to us. | |
350 | */ | |
351 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
352 | other->sk_err = ECONNRESET; | |
353 | other->sk_error_report(other); | |
354 | } | |
355 | } | |
356 | } | |
357 | ||
358 | static void unix_sock_destructor(struct sock *sk) | |
359 | { | |
360 | struct unix_sock *u = unix_sk(sk); | |
361 | ||
362 | skb_queue_purge(&sk->sk_receive_queue); | |
363 | ||
547b792c IJ |
364 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
365 | WARN_ON(!sk_unhashed(sk)); | |
366 | WARN_ON(sk->sk_socket); | |
1da177e4 | 367 | if (!sock_flag(sk, SOCK_DEAD)) { |
6b41e7dd | 368 | printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
369 | return; |
370 | } | |
371 | ||
372 | if (u->addr) | |
373 | unix_release_addr(u->addr); | |
374 | ||
518de9b3 | 375 | atomic_long_dec(&unix_nr_socks); |
6f756a8c | 376 | local_bh_disable(); |
a8076d8d | 377 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
6f756a8c | 378 | local_bh_enable(); |
1da177e4 | 379 | #ifdef UNIX_REFCNT_DEBUG |
518de9b3 ED |
380 | printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk, |
381 | atomic_long_read(&unix_nr_socks)); | |
1da177e4 LT |
382 | #endif |
383 | } | |
384 | ||
ded34e0f | 385 | static void unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
386 | { |
387 | struct unix_sock *u = unix_sk(sk); | |
40ffe67d | 388 | struct path path; |
1da177e4 LT |
389 | struct sock *skpair; |
390 | struct sk_buff *skb; | |
391 | int state; | |
392 | ||
393 | unix_remove_socket(sk); | |
394 | ||
395 | /* Clear state */ | |
1c92b4e5 | 396 | unix_state_lock(sk); |
1da177e4 LT |
397 | sock_orphan(sk); |
398 | sk->sk_shutdown = SHUTDOWN_MASK; | |
40ffe67d AV |
399 | path = u->path; |
400 | u->path.dentry = NULL; | |
401 | u->path.mnt = NULL; | |
1da177e4 LT |
402 | state = sk->sk_state; |
403 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 404 | unix_state_unlock(sk); |
1da177e4 LT |
405 | |
406 | wake_up_interruptible_all(&u->peer_wait); | |
407 | ||
e27dfcea | 408 | skpair = unix_peer(sk); |
1da177e4 | 409 | |
e27dfcea | 410 | if (skpair != NULL) { |
1da177e4 | 411 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 412 | unix_state_lock(skpair); |
1da177e4 LT |
413 | /* No more writes */ |
414 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
415 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
416 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 417 | unix_state_unlock(skpair); |
1da177e4 | 418 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 419 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 LT |
420 | } |
421 | sock_put(skpair); /* It may now die */ | |
422 | unix_peer(sk) = NULL; | |
423 | } | |
424 | ||
425 | /* Try to flush out this socket. Throw out buffers at least */ | |
426 | ||
427 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 428 | if (state == TCP_LISTEN) |
1da177e4 LT |
429 | unix_release_sock(skb->sk, 1); |
430 | /* passed fds are erased in the kfree_skb hook */ | |
431 | kfree_skb(skb); | |
432 | } | |
433 | ||
40ffe67d AV |
434 | if (path.dentry) |
435 | path_put(&path); | |
1da177e4 LT |
436 | |
437 | sock_put(sk); | |
438 | ||
439 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
440 | ||
441 | /* | |
e04dae84 | 442 | * Fixme: BSD difference: In BSD all sockets connected to us get |
1da177e4 LT |
443 | * ECONNRESET and we die on the spot. In Linux we behave |
444 | * like files and pipes do and wait for the last | |
445 | * dereference. | |
446 | * | |
447 | * Can't we simply set sock->err? | |
448 | * | |
449 | * What the above comment does talk about? --ANK(980817) | |
450 | */ | |
451 | ||
9305cfa4 | 452 | if (unix_tot_inflight) |
ac7bfa62 | 453 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
454 | } |
455 | ||
109f6e39 EB |
456 | static void init_peercred(struct sock *sk) |
457 | { | |
458 | put_pid(sk->sk_peer_pid); | |
459 | if (sk->sk_peer_cred) | |
460 | put_cred(sk->sk_peer_cred); | |
461 | sk->sk_peer_pid = get_pid(task_tgid(current)); | |
462 | sk->sk_peer_cred = get_current_cred(); | |
463 | } | |
464 | ||
465 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
466 | { | |
467 | put_pid(sk->sk_peer_pid); | |
468 | if (sk->sk_peer_cred) | |
469 | put_cred(sk->sk_peer_cred); | |
470 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); | |
471 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
472 | } | |
473 | ||
1da177e4 LT |
474 | static int unix_listen(struct socket *sock, int backlog) |
475 | { | |
476 | int err; | |
477 | struct sock *sk = sock->sk; | |
478 | struct unix_sock *u = unix_sk(sk); | |
109f6e39 | 479 | struct pid *old_pid = NULL; |
1da177e4 LT |
480 | |
481 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
482 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
483 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
484 | err = -EINVAL; |
485 | if (!u->addr) | |
6eba6a37 | 486 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 487 | unix_state_lock(sk); |
1da177e4 LT |
488 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
489 | goto out_unlock; | |
490 | if (backlog > sk->sk_max_ack_backlog) | |
491 | wake_up_interruptible_all(&u->peer_wait); | |
492 | sk->sk_max_ack_backlog = backlog; | |
493 | sk->sk_state = TCP_LISTEN; | |
494 | /* set credentials so connect can copy them */ | |
109f6e39 | 495 | init_peercred(sk); |
1da177e4 LT |
496 | err = 0; |
497 | ||
498 | out_unlock: | |
1c92b4e5 | 499 | unix_state_unlock(sk); |
109f6e39 | 500 | put_pid(old_pid); |
1da177e4 LT |
501 | out: |
502 | return err; | |
503 | } | |
504 | ||
505 | static int unix_release(struct socket *); | |
506 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
507 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
508 | int addr_len, int flags); | |
509 | static int unix_socketpair(struct socket *, struct socket *); | |
510 | static int unix_accept(struct socket *, struct socket *, int); | |
511 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
512 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
ec0d215f RW |
513 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
514 | poll_table *); | |
1da177e4 LT |
515 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
516 | static int unix_shutdown(struct socket *, int); | |
517 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
518 | struct msghdr *, size_t); | |
519 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
520 | struct msghdr *, size_t, int); | |
521 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
522 | struct msghdr *, size_t); | |
523 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
524 | struct msghdr *, size_t, int); | |
525 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
526 | int, int); | |
527 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
528 | struct msghdr *, size_t); | |
a05d2ad1 EB |
529 | static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
530 | struct msghdr *, size_t, int); | |
1da177e4 | 531 | |
f55bb7f9 PE |
532 | static void unix_set_peek_off(struct sock *sk, int val) |
533 | { | |
534 | struct unix_sock *u = unix_sk(sk); | |
535 | ||
536 | mutex_lock(&u->readlock); | |
537 | sk->sk_peek_off = val; | |
538 | mutex_unlock(&u->readlock); | |
539 | } | |
540 | ||
541 | ||
90ddc4f0 | 542 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
543 | .family = PF_UNIX, |
544 | .owner = THIS_MODULE, | |
545 | .release = unix_release, | |
546 | .bind = unix_bind, | |
547 | .connect = unix_stream_connect, | |
548 | .socketpair = unix_socketpair, | |
549 | .accept = unix_accept, | |
550 | .getname = unix_getname, | |
551 | .poll = unix_poll, | |
552 | .ioctl = unix_ioctl, | |
553 | .listen = unix_listen, | |
554 | .shutdown = unix_shutdown, | |
555 | .setsockopt = sock_no_setsockopt, | |
556 | .getsockopt = sock_no_getsockopt, | |
557 | .sendmsg = unix_stream_sendmsg, | |
558 | .recvmsg = unix_stream_recvmsg, | |
559 | .mmap = sock_no_mmap, | |
560 | .sendpage = sock_no_sendpage, | |
fc0d7536 | 561 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
562 | }; |
563 | ||
90ddc4f0 | 564 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
565 | .family = PF_UNIX, |
566 | .owner = THIS_MODULE, | |
567 | .release = unix_release, | |
568 | .bind = unix_bind, | |
569 | .connect = unix_dgram_connect, | |
570 | .socketpair = unix_socketpair, | |
571 | .accept = sock_no_accept, | |
572 | .getname = unix_getname, | |
ec0d215f | 573 | .poll = unix_dgram_poll, |
1da177e4 LT |
574 | .ioctl = unix_ioctl, |
575 | .listen = sock_no_listen, | |
576 | .shutdown = unix_shutdown, | |
577 | .setsockopt = sock_no_setsockopt, | |
578 | .getsockopt = sock_no_getsockopt, | |
579 | .sendmsg = unix_dgram_sendmsg, | |
580 | .recvmsg = unix_dgram_recvmsg, | |
581 | .mmap = sock_no_mmap, | |
582 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 583 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
584 | }; |
585 | ||
90ddc4f0 | 586 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
587 | .family = PF_UNIX, |
588 | .owner = THIS_MODULE, | |
589 | .release = unix_release, | |
590 | .bind = unix_bind, | |
591 | .connect = unix_stream_connect, | |
592 | .socketpair = unix_socketpair, | |
593 | .accept = unix_accept, | |
594 | .getname = unix_getname, | |
ec0d215f | 595 | .poll = unix_dgram_poll, |
1da177e4 LT |
596 | .ioctl = unix_ioctl, |
597 | .listen = unix_listen, | |
598 | .shutdown = unix_shutdown, | |
599 | .setsockopt = sock_no_setsockopt, | |
600 | .getsockopt = sock_no_getsockopt, | |
601 | .sendmsg = unix_seqpacket_sendmsg, | |
a05d2ad1 | 602 | .recvmsg = unix_seqpacket_recvmsg, |
1da177e4 LT |
603 | .mmap = sock_no_mmap, |
604 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 605 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
606 | }; |
607 | ||
608 | static struct proto unix_proto = { | |
248969ae ED |
609 | .name = "UNIX", |
610 | .owner = THIS_MODULE, | |
248969ae | 611 | .obj_size = sizeof(struct unix_sock), |
1da177e4 LT |
612 | }; |
613 | ||
a09785a2 IM |
614 | /* |
615 | * AF_UNIX sockets do not interact with hardware, hence they | |
616 | * dont trigger interrupts - so it's safe for them to have | |
617 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
618 | * this special lock-class by reinitializing the spinlock key: | |
619 | */ | |
620 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
621 | ||
6eba6a37 | 622 | static struct sock *unix_create1(struct net *net, struct socket *sock) |
1da177e4 LT |
623 | { |
624 | struct sock *sk = NULL; | |
625 | struct unix_sock *u; | |
626 | ||
518de9b3 ED |
627 | atomic_long_inc(&unix_nr_socks); |
628 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) | |
1da177e4 LT |
629 | goto out; |
630 | ||
6257ff21 | 631 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
1da177e4 LT |
632 | if (!sk) |
633 | goto out; | |
634 | ||
6eba6a37 | 635 | sock_init_data(sock, sk); |
a09785a2 IM |
636 | lockdep_set_class(&sk->sk_receive_queue.lock, |
637 | &af_unix_sk_receive_queue_lock_key); | |
1da177e4 LT |
638 | |
639 | sk->sk_write_space = unix_write_space; | |
a0a53c8b | 640 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
1da177e4 LT |
641 | sk->sk_destruct = unix_sock_destructor; |
642 | u = unix_sk(sk); | |
40ffe67d AV |
643 | u->path.dentry = NULL; |
644 | u->path.mnt = NULL; | |
fd19f329 | 645 | spin_lock_init(&u->lock); |
516e0cc5 | 646 | atomic_long_set(&u->inflight, 0); |
1fd05ba5 | 647 | INIT_LIST_HEAD(&u->link); |
57b47a53 | 648 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 | 649 | init_waitqueue_head(&u->peer_wait); |
7123aaa3 | 650 | unix_insert_socket(unix_sockets_unbound(sk), sk); |
1da177e4 | 651 | out: |
284b327b | 652 | if (sk == NULL) |
518de9b3 | 653 | atomic_long_dec(&unix_nr_socks); |
920de804 ED |
654 | else { |
655 | local_bh_disable(); | |
a8076d8d | 656 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
920de804 ED |
657 | local_bh_enable(); |
658 | } | |
1da177e4 LT |
659 | return sk; |
660 | } | |
661 | ||
3f378b68 EP |
662 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
663 | int kern) | |
1da177e4 LT |
664 | { |
665 | if (protocol && protocol != PF_UNIX) | |
666 | return -EPROTONOSUPPORT; | |
667 | ||
668 | sock->state = SS_UNCONNECTED; | |
669 | ||
670 | switch (sock->type) { | |
671 | case SOCK_STREAM: | |
672 | sock->ops = &unix_stream_ops; | |
673 | break; | |
674 | /* | |
675 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
676 | * nothing uses it. | |
677 | */ | |
678 | case SOCK_RAW: | |
e27dfcea | 679 | sock->type = SOCK_DGRAM; |
1da177e4 LT |
680 | case SOCK_DGRAM: |
681 | sock->ops = &unix_dgram_ops; | |
682 | break; | |
683 | case SOCK_SEQPACKET: | |
684 | sock->ops = &unix_seqpacket_ops; | |
685 | break; | |
686 | default: | |
687 | return -ESOCKTNOSUPPORT; | |
688 | } | |
689 | ||
1b8d7ae4 | 690 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
1da177e4 LT |
691 | } |
692 | ||
693 | static int unix_release(struct socket *sock) | |
694 | { | |
695 | struct sock *sk = sock->sk; | |
696 | ||
697 | if (!sk) | |
698 | return 0; | |
699 | ||
ded34e0f | 700 | unix_release_sock(sk, 0); |
1da177e4 LT |
701 | sock->sk = NULL; |
702 | ||
ded34e0f | 703 | return 0; |
1da177e4 LT |
704 | } |
705 | ||
706 | static int unix_autobind(struct socket *sock) | |
707 | { | |
708 | struct sock *sk = sock->sk; | |
3b1e0a65 | 709 | struct net *net = sock_net(sk); |
1da177e4 LT |
710 | struct unix_sock *u = unix_sk(sk); |
711 | static u32 ordernum = 1; | |
6eba6a37 | 712 | struct unix_address *addr; |
1da177e4 | 713 | int err; |
8df73ff9 | 714 | unsigned int retries = 0; |
1da177e4 | 715 | |
57b47a53 | 716 | mutex_lock(&u->readlock); |
1da177e4 LT |
717 | |
718 | err = 0; | |
719 | if (u->addr) | |
720 | goto out; | |
721 | ||
722 | err = -ENOMEM; | |
0da974f4 | 723 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
724 | if (!addr) |
725 | goto out; | |
726 | ||
1da177e4 LT |
727 | addr->name->sun_family = AF_UNIX; |
728 | atomic_set(&addr->refcnt, 1); | |
729 | ||
730 | retry: | |
731 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
07f0757a | 732 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
1da177e4 | 733 | |
fbe9cc4a | 734 | spin_lock(&unix_table_lock); |
1da177e4 LT |
735 | ordernum = (ordernum+1)&0xFFFFF; |
736 | ||
097e66c5 | 737 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
1da177e4 | 738 | addr->hash)) { |
fbe9cc4a | 739 | spin_unlock(&unix_table_lock); |
8df73ff9 TH |
740 | /* |
741 | * __unix_find_socket_byname() may take long time if many names | |
742 | * are already in use. | |
743 | */ | |
744 | cond_resched(); | |
745 | /* Give up if all names seems to be in use. */ | |
746 | if (retries++ == 0xFFFFF) { | |
747 | err = -ENOSPC; | |
748 | kfree(addr); | |
749 | goto out; | |
750 | } | |
1da177e4 LT |
751 | goto retry; |
752 | } | |
753 | addr->hash ^= sk->sk_type; | |
754 | ||
755 | __unix_remove_socket(sk); | |
756 | u->addr = addr; | |
757 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 758 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
759 | err = 0; |
760 | ||
57b47a53 | 761 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
762 | return err; |
763 | } | |
764 | ||
097e66c5 DL |
765 | static struct sock *unix_find_other(struct net *net, |
766 | struct sockaddr_un *sunname, int len, | |
95c96174 | 767 | int type, unsigned int hash, int *error) |
1da177e4 LT |
768 | { |
769 | struct sock *u; | |
421748ec | 770 | struct path path; |
1da177e4 | 771 | int err = 0; |
ac7bfa62 | 772 | |
1da177e4 | 773 | if (sunname->sun_path[0]) { |
421748ec AV |
774 | struct inode *inode; |
775 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
1da177e4 LT |
776 | if (err) |
777 | goto fail; | |
421748ec AV |
778 | inode = path.dentry->d_inode; |
779 | err = inode_permission(inode, MAY_WRITE); | |
1da177e4 LT |
780 | if (err) |
781 | goto put_fail; | |
782 | ||
783 | err = -ECONNREFUSED; | |
421748ec | 784 | if (!S_ISSOCK(inode->i_mode)) |
1da177e4 | 785 | goto put_fail; |
6616f788 | 786 | u = unix_find_socket_byinode(inode); |
1da177e4 LT |
787 | if (!u) |
788 | goto put_fail; | |
789 | ||
790 | if (u->sk_type == type) | |
68ac1234 | 791 | touch_atime(&path); |
1da177e4 | 792 | |
421748ec | 793 | path_put(&path); |
1da177e4 | 794 | |
e27dfcea | 795 | err = -EPROTOTYPE; |
1da177e4 LT |
796 | if (u->sk_type != type) { |
797 | sock_put(u); | |
798 | goto fail; | |
799 | } | |
800 | } else { | |
801 | err = -ECONNREFUSED; | |
e27dfcea | 802 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
803 | if (u) { |
804 | struct dentry *dentry; | |
40ffe67d | 805 | dentry = unix_sk(u)->path.dentry; |
1da177e4 | 806 | if (dentry) |
68ac1234 | 807 | touch_atime(&unix_sk(u)->path); |
1da177e4 LT |
808 | } else |
809 | goto fail; | |
810 | } | |
811 | return u; | |
812 | ||
813 | put_fail: | |
421748ec | 814 | path_put(&path); |
1da177e4 | 815 | fail: |
e27dfcea | 816 | *error = err; |
1da177e4 LT |
817 | return NULL; |
818 | } | |
819 | ||
faf02010 AV |
820 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) |
821 | { | |
822 | struct dentry *dentry; | |
823 | struct path path; | |
824 | int err = 0; | |
825 | /* | |
826 | * Get the parent directory, calculate the hash for last | |
827 | * component. | |
828 | */ | |
829 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); | |
830 | err = PTR_ERR(dentry); | |
831 | if (IS_ERR(dentry)) | |
832 | return err; | |
833 | ||
834 | /* | |
835 | * All right, let's create it. | |
836 | */ | |
837 | err = security_path_mknod(&path, dentry, mode, 0); | |
838 | if (!err) { | |
839 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); | |
840 | if (!err) { | |
841 | res->mnt = mntget(path.mnt); | |
842 | res->dentry = dget(dentry); | |
843 | } | |
844 | } | |
845 | done_path_create(&path, dentry); | |
846 | return err; | |
847 | } | |
1da177e4 LT |
848 | |
849 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
850 | { | |
851 | struct sock *sk = sock->sk; | |
3b1e0a65 | 852 | struct net *net = sock_net(sk); |
1da177e4 | 853 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 854 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
dae6ad8f | 855 | char *sun_path = sunaddr->sun_path; |
1da177e4 | 856 | int err; |
95c96174 | 857 | unsigned int hash; |
1da177e4 LT |
858 | struct unix_address *addr; |
859 | struct hlist_head *list; | |
860 | ||
861 | err = -EINVAL; | |
862 | if (sunaddr->sun_family != AF_UNIX) | |
863 | goto out; | |
864 | ||
e27dfcea | 865 | if (addr_len == sizeof(short)) { |
1da177e4 LT |
866 | err = unix_autobind(sock); |
867 | goto out; | |
868 | } | |
869 | ||
870 | err = unix_mkname(sunaddr, addr_len, &hash); | |
871 | if (err < 0) | |
872 | goto out; | |
873 | addr_len = err; | |
874 | ||
57b47a53 | 875 | mutex_lock(&u->readlock); |
1da177e4 LT |
876 | |
877 | err = -EINVAL; | |
878 | if (u->addr) | |
879 | goto out_up; | |
880 | ||
881 | err = -ENOMEM; | |
882 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
883 | if (!addr) | |
884 | goto out_up; | |
885 | ||
886 | memcpy(addr->name, sunaddr, addr_len); | |
887 | addr->len = addr_len; | |
888 | addr->hash = hash ^ sk->sk_type; | |
889 | atomic_set(&addr->refcnt, 1); | |
890 | ||
dae6ad8f | 891 | if (sun_path[0]) { |
faf02010 AV |
892 | struct path path; |
893 | umode_t mode = S_IFSOCK | | |
ce3b0f8d | 894 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
faf02010 AV |
895 | err = unix_mknod(sun_path, mode, &path); |
896 | if (err) { | |
897 | if (err == -EEXIST) | |
898 | err = -EADDRINUSE; | |
899 | unix_release_addr(addr); | |
900 | goto out_up; | |
901 | } | |
1da177e4 | 902 | addr->hash = UNIX_HASH_SIZE; |
faf02010 AV |
903 | hash = path.dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1); |
904 | spin_lock(&unix_table_lock); | |
905 | u->path = path; | |
906 | list = &unix_socket_table[hash]; | |
907 | } else { | |
908 | spin_lock(&unix_table_lock); | |
1da177e4 | 909 | err = -EADDRINUSE; |
097e66c5 | 910 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
1da177e4 LT |
911 | sk->sk_type, hash)) { |
912 | unix_release_addr(addr); | |
913 | goto out_unlock; | |
914 | } | |
915 | ||
916 | list = &unix_socket_table[addr->hash]; | |
1da177e4 LT |
917 | } |
918 | ||
919 | err = 0; | |
920 | __unix_remove_socket(sk); | |
921 | u->addr = addr; | |
922 | __unix_insert_socket(list, sk); | |
923 | ||
924 | out_unlock: | |
fbe9cc4a | 925 | spin_unlock(&unix_table_lock); |
1da177e4 | 926 | out_up: |
57b47a53 | 927 | mutex_unlock(&u->readlock); |
1da177e4 LT |
928 | out: |
929 | return err; | |
1da177e4 LT |
930 | } |
931 | ||
278a3de5 DM |
932 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
933 | { | |
934 | if (unlikely(sk1 == sk2) || !sk2) { | |
935 | unix_state_lock(sk1); | |
936 | return; | |
937 | } | |
938 | if (sk1 < sk2) { | |
939 | unix_state_lock(sk1); | |
940 | unix_state_lock_nested(sk2); | |
941 | } else { | |
942 | unix_state_lock(sk2); | |
943 | unix_state_lock_nested(sk1); | |
944 | } | |
945 | } | |
946 | ||
947 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
948 | { | |
949 | if (unlikely(sk1 == sk2) || !sk2) { | |
950 | unix_state_unlock(sk1); | |
951 | return; | |
952 | } | |
953 | unix_state_unlock(sk1); | |
954 | unix_state_unlock(sk2); | |
955 | } | |
956 | ||
1da177e4 LT |
957 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
958 | int alen, int flags) | |
959 | { | |
960 | struct sock *sk = sock->sk; | |
3b1e0a65 | 961 | struct net *net = sock_net(sk); |
e27dfcea | 962 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
1da177e4 | 963 | struct sock *other; |
95c96174 | 964 | unsigned int hash; |
1da177e4 LT |
965 | int err; |
966 | ||
967 | if (addr->sa_family != AF_UNSPEC) { | |
968 | err = unix_mkname(sunaddr, alen, &hash); | |
969 | if (err < 0) | |
970 | goto out; | |
971 | alen = err; | |
972 | ||
973 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
974 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
975 | goto out; | |
976 | ||
278a3de5 | 977 | restart: |
e27dfcea | 978 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
1da177e4 LT |
979 | if (!other) |
980 | goto out; | |
981 | ||
278a3de5 DM |
982 | unix_state_double_lock(sk, other); |
983 | ||
984 | /* Apparently VFS overslept socket death. Retry. */ | |
985 | if (sock_flag(other, SOCK_DEAD)) { | |
986 | unix_state_double_unlock(sk, other); | |
987 | sock_put(other); | |
988 | goto restart; | |
989 | } | |
1da177e4 LT |
990 | |
991 | err = -EPERM; | |
992 | if (!unix_may_send(sk, other)) | |
993 | goto out_unlock; | |
994 | ||
995 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
996 | if (err) | |
997 | goto out_unlock; | |
998 | ||
999 | } else { | |
1000 | /* | |
1001 | * 1003.1g breaking connected state with AF_UNSPEC | |
1002 | */ | |
1003 | other = NULL; | |
278a3de5 | 1004 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1005 | } |
1006 | ||
1007 | /* | |
1008 | * If it was connected, reconnect. | |
1009 | */ | |
1010 | if (unix_peer(sk)) { | |
1011 | struct sock *old_peer = unix_peer(sk); | |
e27dfcea | 1012 | unix_peer(sk) = other; |
278a3de5 | 1013 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1014 | |
1015 | if (other != old_peer) | |
1016 | unix_dgram_disconnected(sk, old_peer); | |
1017 | sock_put(old_peer); | |
1018 | } else { | |
e27dfcea | 1019 | unix_peer(sk) = other; |
278a3de5 | 1020 | unix_state_double_unlock(sk, other); |
1da177e4 | 1021 | } |
ac7bfa62 | 1022 | return 0; |
1da177e4 LT |
1023 | |
1024 | out_unlock: | |
278a3de5 | 1025 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1026 | sock_put(other); |
1027 | out: | |
1028 | return err; | |
1029 | } | |
1030 | ||
1031 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1032 | { | |
1033 | struct unix_sock *u = unix_sk(other); | |
1034 | int sched; | |
1035 | DEFINE_WAIT(wait); | |
1036 | ||
1037 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1038 | ||
1039 | sched = !sock_flag(other, SOCK_DEAD) && | |
1040 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
3c73419c | 1041 | unix_recvq_full(other); |
1da177e4 | 1042 | |
1c92b4e5 | 1043 | unix_state_unlock(other); |
1da177e4 LT |
1044 | |
1045 | if (sched) | |
1046 | timeo = schedule_timeout(timeo); | |
1047 | ||
1048 | finish_wait(&u->peer_wait, &wait); | |
1049 | return timeo; | |
1050 | } | |
1051 | ||
1052 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1053 | int addr_len, int flags) | |
1054 | { | |
e27dfcea | 1055 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1da177e4 | 1056 | struct sock *sk = sock->sk; |
3b1e0a65 | 1057 | struct net *net = sock_net(sk); |
1da177e4 LT |
1058 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1059 | struct sock *newsk = NULL; | |
1060 | struct sock *other = NULL; | |
1061 | struct sk_buff *skb = NULL; | |
95c96174 | 1062 | unsigned int hash; |
1da177e4 LT |
1063 | int st; |
1064 | int err; | |
1065 | long timeo; | |
1066 | ||
1067 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1068 | if (err < 0) | |
1069 | goto out; | |
1070 | addr_len = err; | |
1071 | ||
f64f9e71 JP |
1072 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
1073 | (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1074 | goto out; |
1075 | ||
1076 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1077 | ||
1078 | /* First of all allocate resources. | |
1079 | If we will make it after state is locked, | |
1080 | we will have to recheck all again in any case. | |
1081 | */ | |
1082 | ||
1083 | err = -ENOMEM; | |
1084 | ||
1085 | /* create new sock for complete connection */ | |
3b1e0a65 | 1086 | newsk = unix_create1(sock_net(sk), NULL); |
1da177e4 LT |
1087 | if (newsk == NULL) |
1088 | goto out; | |
1089 | ||
1090 | /* Allocate skb for sending to listening sock */ | |
1091 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1092 | if (skb == NULL) | |
1093 | goto out; | |
1094 | ||
1095 | restart: | |
1096 | /* Find listening sock. */ | |
097e66c5 | 1097 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1da177e4 LT |
1098 | if (!other) |
1099 | goto out; | |
1100 | ||
1101 | /* Latch state of peer */ | |
1c92b4e5 | 1102 | unix_state_lock(other); |
1da177e4 LT |
1103 | |
1104 | /* Apparently VFS overslept socket death. Retry. */ | |
1105 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1106 | unix_state_unlock(other); |
1da177e4 LT |
1107 | sock_put(other); |
1108 | goto restart; | |
1109 | } | |
1110 | ||
1111 | err = -ECONNREFUSED; | |
1112 | if (other->sk_state != TCP_LISTEN) | |
1113 | goto out_unlock; | |
77238f2b TS |
1114 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1115 | goto out_unlock; | |
1da177e4 | 1116 | |
3c73419c | 1117 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1118 | err = -EAGAIN; |
1119 | if (!timeo) | |
1120 | goto out_unlock; | |
1121 | ||
1122 | timeo = unix_wait_for_peer(other, timeo); | |
1123 | ||
1124 | err = sock_intr_errno(timeo); | |
1125 | if (signal_pending(current)) | |
1126 | goto out; | |
1127 | sock_put(other); | |
1128 | goto restart; | |
ac7bfa62 | 1129 | } |
1da177e4 LT |
1130 | |
1131 | /* Latch our state. | |
1132 | ||
e5537bfc | 1133 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1134 | drop lock on peer. It is dangerous because deadlock is |
1135 | possible. Connect to self case and simultaneous | |
1136 | attempt to connect are eliminated by checking socket | |
1137 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1138 | check this before attempt to grab lock. | |
1139 | ||
1140 | Well, and we have to recheck the state after socket locked. | |
1141 | */ | |
1142 | st = sk->sk_state; | |
1143 | ||
1144 | switch (st) { | |
1145 | case TCP_CLOSE: | |
1146 | /* This is ok... continue with connect */ | |
1147 | break; | |
1148 | case TCP_ESTABLISHED: | |
1149 | /* Socket is already connected */ | |
1150 | err = -EISCONN; | |
1151 | goto out_unlock; | |
1152 | default: | |
1153 | err = -EINVAL; | |
1154 | goto out_unlock; | |
1155 | } | |
1156 | ||
1c92b4e5 | 1157 | unix_state_lock_nested(sk); |
1da177e4 LT |
1158 | |
1159 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1160 | unix_state_unlock(sk); |
1161 | unix_state_unlock(other); | |
1da177e4 LT |
1162 | sock_put(other); |
1163 | goto restart; | |
1164 | } | |
1165 | ||
3610cda5 | 1166 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1167 | if (err) { |
1c92b4e5 | 1168 | unix_state_unlock(sk); |
1da177e4 LT |
1169 | goto out_unlock; |
1170 | } | |
1171 | ||
1172 | /* The way is open! Fastly set all the necessary fields... */ | |
1173 | ||
1174 | sock_hold(sk); | |
1175 | unix_peer(newsk) = sk; | |
1176 | newsk->sk_state = TCP_ESTABLISHED; | |
1177 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1178 | init_peercred(newsk); |
1da177e4 | 1179 | newu = unix_sk(newsk); |
eaefd110 | 1180 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1181 | otheru = unix_sk(other); |
1182 | ||
1183 | /* copy address information from listening to new sock*/ | |
1184 | if (otheru->addr) { | |
1185 | atomic_inc(&otheru->addr->refcnt); | |
1186 | newu->addr = otheru->addr; | |
1187 | } | |
40ffe67d AV |
1188 | if (otheru->path.dentry) { |
1189 | path_get(&otheru->path); | |
1190 | newu->path = otheru->path; | |
1da177e4 LT |
1191 | } |
1192 | ||
1193 | /* Set credentials */ | |
109f6e39 | 1194 | copy_peercred(sk, other); |
1da177e4 | 1195 | |
1da177e4 LT |
1196 | sock->state = SS_CONNECTED; |
1197 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1198 | sock_hold(newsk); |
1199 | ||
1200 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1201 | unix_peer(sk) = newsk; | |
1da177e4 | 1202 | |
1c92b4e5 | 1203 | unix_state_unlock(sk); |
1da177e4 LT |
1204 | |
1205 | /* take ten and and send info to listening sock */ | |
1206 | spin_lock(&other->sk_receive_queue.lock); | |
1207 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1208 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1209 | unix_state_unlock(other); |
1da177e4 LT |
1210 | other->sk_data_ready(other, 0); |
1211 | sock_put(other); | |
1212 | return 0; | |
1213 | ||
1214 | out_unlock: | |
1215 | if (other) | |
1c92b4e5 | 1216 | unix_state_unlock(other); |
1da177e4 LT |
1217 | |
1218 | out: | |
40d44446 | 1219 | kfree_skb(skb); |
1da177e4 LT |
1220 | if (newsk) |
1221 | unix_release_sock(newsk, 0); | |
1222 | if (other) | |
1223 | sock_put(other); | |
1224 | return err; | |
1225 | } | |
1226 | ||
1227 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1228 | { | |
e27dfcea | 1229 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1230 | |
1231 | /* Join our sockets back to back */ | |
1232 | sock_hold(ska); | |
1233 | sock_hold(skb); | |
e27dfcea JK |
1234 | unix_peer(ska) = skb; |
1235 | unix_peer(skb) = ska; | |
109f6e39 EB |
1236 | init_peercred(ska); |
1237 | init_peercred(skb); | |
1da177e4 LT |
1238 | |
1239 | if (ska->sk_type != SOCK_DGRAM) { | |
1240 | ska->sk_state = TCP_ESTABLISHED; | |
1241 | skb->sk_state = TCP_ESTABLISHED; | |
1242 | socka->state = SS_CONNECTED; | |
1243 | sockb->state = SS_CONNECTED; | |
1244 | } | |
1245 | return 0; | |
1246 | } | |
1247 | ||
1248 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) | |
1249 | { | |
1250 | struct sock *sk = sock->sk; | |
1251 | struct sock *tsk; | |
1252 | struct sk_buff *skb; | |
1253 | int err; | |
1254 | ||
1255 | err = -EOPNOTSUPP; | |
6eba6a37 | 1256 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1257 | goto out; |
1258 | ||
1259 | err = -EINVAL; | |
1260 | if (sk->sk_state != TCP_LISTEN) | |
1261 | goto out; | |
1262 | ||
1263 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1264 | * so that no locks are necessary. | |
1265 | */ | |
1266 | ||
1267 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1268 | if (!skb) { | |
1269 | /* This means receive shutdown. */ | |
1270 | if (err == 0) | |
1271 | err = -EINVAL; | |
1272 | goto out; | |
1273 | } | |
1274 | ||
1275 | tsk = skb->sk; | |
1276 | skb_free_datagram(sk, skb); | |
1277 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1278 | ||
1279 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1280 | unix_state_lock(tsk); |
1da177e4 LT |
1281 | newsock->state = SS_CONNECTED; |
1282 | sock_graft(tsk, newsock); | |
1c92b4e5 | 1283 | unix_state_unlock(tsk); |
1da177e4 LT |
1284 | return 0; |
1285 | ||
1286 | out: | |
1287 | return err; | |
1288 | } | |
1289 | ||
1290 | ||
1291 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1292 | { | |
1293 | struct sock *sk = sock->sk; | |
1294 | struct unix_sock *u; | |
13cfa97b | 1295 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1296 | int err = 0; |
1297 | ||
1298 | if (peer) { | |
1299 | sk = unix_peer_get(sk); | |
1300 | ||
1301 | err = -ENOTCONN; | |
1302 | if (!sk) | |
1303 | goto out; | |
1304 | err = 0; | |
1305 | } else { | |
1306 | sock_hold(sk); | |
1307 | } | |
1308 | ||
1309 | u = unix_sk(sk); | |
1c92b4e5 | 1310 | unix_state_lock(sk); |
1da177e4 LT |
1311 | if (!u->addr) { |
1312 | sunaddr->sun_family = AF_UNIX; | |
1313 | sunaddr->sun_path[0] = 0; | |
1314 | *uaddr_len = sizeof(short); | |
1315 | } else { | |
1316 | struct unix_address *addr = u->addr; | |
1317 | ||
1318 | *uaddr_len = addr->len; | |
1319 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1320 | } | |
1c92b4e5 | 1321 | unix_state_unlock(sk); |
1da177e4 LT |
1322 | sock_put(sk); |
1323 | out: | |
1324 | return err; | |
1325 | } | |
1326 | ||
1327 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1328 | { | |
1329 | int i; | |
1330 | ||
1331 | scm->fp = UNIXCB(skb).fp; | |
1da177e4 LT |
1332 | UNIXCB(skb).fp = NULL; |
1333 | ||
6eba6a37 | 1334 | for (i = scm->fp->count-1; i >= 0; i--) |
1da177e4 LT |
1335 | unix_notinflight(scm->fp->fp[i]); |
1336 | } | |
1337 | ||
7361c36c | 1338 | static void unix_destruct_scm(struct sk_buff *skb) |
1da177e4 LT |
1339 | { |
1340 | struct scm_cookie scm; | |
1341 | memset(&scm, 0, sizeof(scm)); | |
7361c36c | 1342 | scm.pid = UNIXCB(skb).pid; |
7361c36c EB |
1343 | if (UNIXCB(skb).fp) |
1344 | unix_detach_fds(&scm, skb); | |
1da177e4 LT |
1345 | |
1346 | /* Alas, it calls VFS */ | |
1347 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1348 | scm_destroy(&scm); | |
1349 | sock_wfree(skb); | |
1350 | } | |
1351 | ||
25888e30 ED |
1352 | #define MAX_RECURSION_LEVEL 4 |
1353 | ||
6209344f | 1354 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1da177e4 LT |
1355 | { |
1356 | int i; | |
25888e30 ED |
1357 | unsigned char max_level = 0; |
1358 | int unix_sock_count = 0; | |
1359 | ||
1360 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1361 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1362 | ||
1363 | if (sk) { | |
1364 | unix_sock_count++; | |
1365 | max_level = max(max_level, | |
1366 | unix_sk(sk)->recursion_level); | |
1367 | } | |
1368 | } | |
1369 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1370 | return -ETOOMANYREFS; | |
6209344f MS |
1371 | |
1372 | /* | |
1373 | * Need to duplicate file references for the sake of garbage | |
1374 | * collection. Otherwise a socket in the fps might become a | |
1375 | * candidate for GC while the skb is not yet queued. | |
1376 | */ | |
1377 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1378 | if (!UNIXCB(skb).fp) | |
1379 | return -ENOMEM; | |
1380 | ||
25888e30 ED |
1381 | if (unix_sock_count) { |
1382 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1383 | unix_inflight(scm->fp->fp[i]); | |
1384 | } | |
1385 | return max_level; | |
1da177e4 LT |
1386 | } |
1387 | ||
f78a5fda | 1388 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1389 | { |
1390 | int err = 0; | |
16e57262 | 1391 | |
f78a5fda | 1392 | UNIXCB(skb).pid = get_pid(scm->pid); |
6b0ee8c0 EB |
1393 | UNIXCB(skb).uid = scm->creds.uid; |
1394 | UNIXCB(skb).gid = scm->creds.gid; | |
7361c36c EB |
1395 | UNIXCB(skb).fp = NULL; |
1396 | if (scm->fp && send_fds) | |
1397 | err = unix_attach_fds(scm, skb); | |
1398 | ||
1399 | skb->destructor = unix_destruct_scm; | |
1400 | return err; | |
1401 | } | |
1402 | ||
16e57262 ED |
1403 | /* |
1404 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1405 | * We include credentials if source or destination socket | |
1406 | * asserted SOCK_PASSCRED. | |
1407 | */ | |
1408 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1409 | const struct sock *other) | |
1410 | { | |
6b0ee8c0 | 1411 | if (UNIXCB(skb).pid) |
16e57262 ED |
1412 | return; |
1413 | if (test_bit(SOCK_PASSCRED, &sock->flags) || | |
25da0e3e EB |
1414 | !other->sk_socket || |
1415 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { | |
16e57262 | 1416 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
6e0895c2 | 1417 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); |
16e57262 ED |
1418 | } |
1419 | } | |
1420 | ||
1da177e4 LT |
1421 | /* |
1422 | * Send AF_UNIX data. | |
1423 | */ | |
1424 | ||
1425 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1426 | struct msghdr *msg, size_t len) | |
1427 | { | |
1428 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1429 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1430 | struct net *net = sock_net(sk); |
1da177e4 | 1431 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 1432 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1433 | struct sock *other = NULL; |
1434 | int namelen = 0; /* fake GCC */ | |
1435 | int err; | |
95c96174 | 1436 | unsigned int hash; |
f78a5fda | 1437 | struct sk_buff *skb; |
1da177e4 LT |
1438 | long timeo; |
1439 | struct scm_cookie tmp_scm; | |
25888e30 | 1440 | int max_level; |
eb6a2481 | 1441 | int data_len = 0; |
1da177e4 LT |
1442 | |
1443 | if (NULL == siocb->scm) | |
1444 | siocb->scm = &tmp_scm; | |
5f23b734 | 1445 | wait_for_unix_gc(); |
e0e3cea4 | 1446 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1447 | if (err < 0) |
1448 | return err; | |
1449 | ||
1450 | err = -EOPNOTSUPP; | |
1451 | if (msg->msg_flags&MSG_OOB) | |
1452 | goto out; | |
1453 | ||
1454 | if (msg->msg_namelen) { | |
1455 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1456 | if (err < 0) | |
1457 | goto out; | |
1458 | namelen = err; | |
1459 | } else { | |
1460 | sunaddr = NULL; | |
1461 | err = -ENOTCONN; | |
1462 | other = unix_peer_get(sk); | |
1463 | if (!other) | |
1464 | goto out; | |
1465 | } | |
1466 | ||
f64f9e71 JP |
1467 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
1468 | && (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1469 | goto out; |
1470 | ||
1471 | err = -EMSGSIZE; | |
1472 | if (len > sk->sk_sndbuf - 32) | |
1473 | goto out; | |
1474 | ||
eb6a2481 ED |
1475 | if (len > SKB_MAX_ALLOC) |
1476 | data_len = min_t(size_t, | |
1477 | len - SKB_MAX_ALLOC, | |
1478 | MAX_SKB_FRAGS * PAGE_SIZE); | |
1479 | ||
1480 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
1481 | msg->msg_flags & MSG_DONTWAIT, &err); | |
e27dfcea | 1482 | if (skb == NULL) |
1da177e4 LT |
1483 | goto out; |
1484 | ||
f78a5fda | 1485 | err = unix_scm_to_skb(siocb->scm, skb, true); |
25888e30 | 1486 | if (err < 0) |
7361c36c | 1487 | goto out_free; |
25888e30 | 1488 | max_level = err + 1; |
dc49c1f9 | 1489 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1490 | |
eb6a2481 ED |
1491 | skb_put(skb, len - data_len); |
1492 | skb->data_len = data_len; | |
1493 | skb->len = len; | |
1494 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); | |
1da177e4 LT |
1495 | if (err) |
1496 | goto out_free; | |
1497 | ||
1498 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1499 | ||
1500 | restart: | |
1501 | if (!other) { | |
1502 | err = -ECONNRESET; | |
1503 | if (sunaddr == NULL) | |
1504 | goto out_free; | |
1505 | ||
097e66c5 | 1506 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1da177e4 | 1507 | hash, &err); |
e27dfcea | 1508 | if (other == NULL) |
1da177e4 LT |
1509 | goto out_free; |
1510 | } | |
1511 | ||
d6ae3bae AC |
1512 | if (sk_filter(other, skb) < 0) { |
1513 | /* Toss the packet but do not return any error to the sender */ | |
1514 | err = len; | |
1515 | goto out_free; | |
1516 | } | |
1517 | ||
1c92b4e5 | 1518 | unix_state_lock(other); |
1da177e4 LT |
1519 | err = -EPERM; |
1520 | if (!unix_may_send(sk, other)) | |
1521 | goto out_unlock; | |
1522 | ||
1523 | if (sock_flag(other, SOCK_DEAD)) { | |
1524 | /* | |
1525 | * Check with 1003.1g - what should | |
1526 | * datagram error | |
1527 | */ | |
1c92b4e5 | 1528 | unix_state_unlock(other); |
1da177e4 LT |
1529 | sock_put(other); |
1530 | ||
1531 | err = 0; | |
1c92b4e5 | 1532 | unix_state_lock(sk); |
1da177e4 | 1533 | if (unix_peer(sk) == other) { |
e27dfcea | 1534 | unix_peer(sk) = NULL; |
1c92b4e5 | 1535 | unix_state_unlock(sk); |
1da177e4 LT |
1536 | |
1537 | unix_dgram_disconnected(sk, other); | |
1538 | sock_put(other); | |
1539 | err = -ECONNREFUSED; | |
1540 | } else { | |
1c92b4e5 | 1541 | unix_state_unlock(sk); |
1da177e4 LT |
1542 | } |
1543 | ||
1544 | other = NULL; | |
1545 | if (err) | |
1546 | goto out_free; | |
1547 | goto restart; | |
1548 | } | |
1549 | ||
1550 | err = -EPIPE; | |
1551 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1552 | goto out_unlock; | |
1553 | ||
1554 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1555 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1556 | if (err) | |
1557 | goto out_unlock; | |
1558 | } | |
1559 | ||
3c73419c | 1560 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1da177e4 LT |
1561 | if (!timeo) { |
1562 | err = -EAGAIN; | |
1563 | goto out_unlock; | |
1564 | } | |
1565 | ||
1566 | timeo = unix_wait_for_peer(other, timeo); | |
1567 | ||
1568 | err = sock_intr_errno(timeo); | |
1569 | if (signal_pending(current)) | |
1570 | goto out_free; | |
1571 | ||
1572 | goto restart; | |
1573 | } | |
1574 | ||
3f66116e AC |
1575 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
1576 | __net_timestamp(skb); | |
16e57262 | 1577 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1578 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1579 | if (max_level > unix_sk(other)->recursion_level) |
1580 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1581 | unix_state_unlock(other); |
1da177e4 LT |
1582 | other->sk_data_ready(other, len); |
1583 | sock_put(other); | |
f78a5fda | 1584 | scm_destroy(siocb->scm); |
1da177e4 LT |
1585 | return len; |
1586 | ||
1587 | out_unlock: | |
1c92b4e5 | 1588 | unix_state_unlock(other); |
1da177e4 LT |
1589 | out_free: |
1590 | kfree_skb(skb); | |
1591 | out: | |
1592 | if (other) | |
1593 | sock_put(other); | |
f78a5fda | 1594 | scm_destroy(siocb->scm); |
1da177e4 LT |
1595 | return err; |
1596 | } | |
1597 | ||
ac7bfa62 | 1598 | |
1da177e4 LT |
1599 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1600 | struct msghdr *msg, size_t len) | |
1601 | { | |
1602 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1603 | struct sock *sk = sock->sk; | |
1604 | struct sock *other = NULL; | |
6eba6a37 | 1605 | int err, size; |
f78a5fda | 1606 | struct sk_buff *skb; |
e27dfcea | 1607 | int sent = 0; |
1da177e4 | 1608 | struct scm_cookie tmp_scm; |
8ba69ba6 | 1609 | bool fds_sent = false; |
25888e30 | 1610 | int max_level; |
1da177e4 LT |
1611 | |
1612 | if (NULL == siocb->scm) | |
1613 | siocb->scm = &tmp_scm; | |
5f23b734 | 1614 | wait_for_unix_gc(); |
e0e3cea4 | 1615 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1616 | if (err < 0) |
1617 | return err; | |
1618 | ||
1619 | err = -EOPNOTSUPP; | |
1620 | if (msg->msg_flags&MSG_OOB) | |
1621 | goto out_err; | |
1622 | ||
1623 | if (msg->msg_namelen) { | |
1624 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1625 | goto out_err; | |
1626 | } else { | |
1da177e4 | 1627 | err = -ENOTCONN; |
830a1e5c | 1628 | other = unix_peer(sk); |
1da177e4 LT |
1629 | if (!other) |
1630 | goto out_err; | |
1631 | } | |
1632 | ||
1633 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1634 | goto pipe_err; | |
1635 | ||
6eba6a37 | 1636 | while (sent < len) { |
1da177e4 | 1637 | /* |
e9df7d7f BL |
1638 | * Optimisation for the fact that under 0.01% of X |
1639 | * messages typically need breaking up. | |
1da177e4 LT |
1640 | */ |
1641 | ||
e9df7d7f | 1642 | size = len-sent; |
1da177e4 LT |
1643 | |
1644 | /* Keep two messages in the pipe so it schedules better */ | |
e9df7d7f BL |
1645 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
1646 | size = (sk->sk_sndbuf >> 1) - 64; | |
1da177e4 LT |
1647 | |
1648 | if (size > SKB_MAX_ALLOC) | |
1649 | size = SKB_MAX_ALLOC; | |
ac7bfa62 | 1650 | |
1da177e4 LT |
1651 | /* |
1652 | * Grab a buffer | |
1653 | */ | |
ac7bfa62 | 1654 | |
6eba6a37 ED |
1655 | skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, |
1656 | &err); | |
1da177e4 | 1657 | |
e27dfcea | 1658 | if (skb == NULL) |
1da177e4 LT |
1659 | goto out_err; |
1660 | ||
1661 | /* | |
1662 | * If you pass two values to the sock_alloc_send_skb | |
1663 | * it tries to grab the large buffer with GFP_NOFS | |
1664 | * (which can fail easily), and if it fails grab the | |
1665 | * fallback size buffer which is under a page and will | |
1666 | * succeed. [Alan] | |
1667 | */ | |
1668 | size = min_t(int, size, skb_tailroom(skb)); | |
1669 | ||
7361c36c | 1670 | |
f78a5fda DM |
1671 | /* Only send the fds in the first buffer */ |
1672 | err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); | |
25888e30 | 1673 | if (err < 0) { |
7361c36c | 1674 | kfree_skb(skb); |
f78a5fda | 1675 | goto out_err; |
6209344f | 1676 | } |
25888e30 | 1677 | max_level = err + 1; |
7361c36c | 1678 | fds_sent = true; |
1da177e4 | 1679 | |
6eba6a37 ED |
1680 | err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
1681 | if (err) { | |
1da177e4 | 1682 | kfree_skb(skb); |
f78a5fda | 1683 | goto out_err; |
1da177e4 LT |
1684 | } |
1685 | ||
1c92b4e5 | 1686 | unix_state_lock(other); |
1da177e4 LT |
1687 | |
1688 | if (sock_flag(other, SOCK_DEAD) || | |
1689 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1690 | goto pipe_err_free; | |
1691 | ||
16e57262 | 1692 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1693 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1694 | if (max_level > unix_sk(other)->recursion_level) |
1695 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1696 | unix_state_unlock(other); |
1da177e4 | 1697 | other->sk_data_ready(other, size); |
e27dfcea | 1698 | sent += size; |
1da177e4 | 1699 | } |
1da177e4 | 1700 | |
f78a5fda | 1701 | scm_destroy(siocb->scm); |
1da177e4 LT |
1702 | siocb->scm = NULL; |
1703 | ||
1704 | return sent; | |
1705 | ||
1706 | pipe_err_free: | |
1c92b4e5 | 1707 | unix_state_unlock(other); |
1da177e4 LT |
1708 | kfree_skb(skb); |
1709 | pipe_err: | |
6eba6a37 ED |
1710 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1711 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
1712 | err = -EPIPE; |
1713 | out_err: | |
f78a5fda | 1714 | scm_destroy(siocb->scm); |
1da177e4 LT |
1715 | siocb->scm = NULL; |
1716 | return sent ? : err; | |
1717 | } | |
1718 | ||
1719 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1720 | struct msghdr *msg, size_t len) | |
1721 | { | |
1722 | int err; | |
1723 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1724 | |
1da177e4 LT |
1725 | err = sock_error(sk); |
1726 | if (err) | |
1727 | return err; | |
1728 | ||
1729 | if (sk->sk_state != TCP_ESTABLISHED) | |
1730 | return -ENOTCONN; | |
1731 | ||
1732 | if (msg->msg_namelen) | |
1733 | msg->msg_namelen = 0; | |
1734 | ||
1735 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1736 | } | |
ac7bfa62 | 1737 | |
a05d2ad1 EB |
1738 | static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
1739 | struct msghdr *msg, size_t size, | |
1740 | int flags) | |
1741 | { | |
1742 | struct sock *sk = sock->sk; | |
1743 | ||
1744 | if (sk->sk_state != TCP_ESTABLISHED) | |
1745 | return -ENOTCONN; | |
1746 | ||
1747 | return unix_dgram_recvmsg(iocb, sock, msg, size, flags); | |
1748 | } | |
1749 | ||
1da177e4 LT |
1750 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1751 | { | |
1752 | struct unix_sock *u = unix_sk(sk); | |
1753 | ||
1754 | msg->msg_namelen = 0; | |
1755 | if (u->addr) { | |
1756 | msg->msg_namelen = u->addr->len; | |
1757 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1762 | struct msghdr *msg, size_t size, | |
1763 | int flags) | |
1764 | { | |
1765 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1766 | struct scm_cookie tmp_scm; | |
1767 | struct sock *sk = sock->sk; | |
1768 | struct unix_sock *u = unix_sk(sk); | |
1769 | int noblock = flags & MSG_DONTWAIT; | |
1770 | struct sk_buff *skb; | |
1771 | int err; | |
f55bb7f9 | 1772 | int peeked, skip; |
1da177e4 LT |
1773 | |
1774 | err = -EOPNOTSUPP; | |
1775 | if (flags&MSG_OOB) | |
1776 | goto out; | |
1777 | ||
1778 | msg->msg_namelen = 0; | |
1779 | ||
b3ca9b02 RW |
1780 | err = mutex_lock_interruptible(&u->readlock); |
1781 | if (err) { | |
1782 | err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); | |
1783 | goto out; | |
1784 | } | |
1da177e4 | 1785 | |
f55bb7f9 PE |
1786 | skip = sk_peek_offset(sk, flags); |
1787 | ||
1788 | skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); | |
0a112258 FZ |
1789 | if (!skb) { |
1790 | unix_state_lock(sk); | |
1791 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
1792 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
1793 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1794 | err = 0; | |
1795 | unix_state_unlock(sk); | |
1da177e4 | 1796 | goto out_unlock; |
0a112258 | 1797 | } |
1da177e4 | 1798 | |
67426b75 ED |
1799 | wake_up_interruptible_sync_poll(&u->peer_wait, |
1800 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
1da177e4 LT |
1801 | |
1802 | if (msg->msg_name) | |
1803 | unix_copy_addr(msg, skb->sk); | |
1804 | ||
f55bb7f9 PE |
1805 | if (size > skb->len - skip) |
1806 | size = skb->len - skip; | |
1807 | else if (size < skb->len - skip) | |
1da177e4 LT |
1808 | msg->msg_flags |= MSG_TRUNC; |
1809 | ||
f55bb7f9 | 1810 | err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size); |
1da177e4 LT |
1811 | if (err) |
1812 | goto out_free; | |
1813 | ||
3f66116e AC |
1814 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
1815 | __sock_recv_timestamp(msg, sk, skb); | |
1816 | ||
1da177e4 LT |
1817 | if (!siocb->scm) { |
1818 | siocb->scm = &tmp_scm; | |
1819 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1820 | } | |
6b0ee8c0 | 1821 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
877ce7c1 | 1822 | unix_set_secdata(siocb->scm, skb); |
1da177e4 | 1823 | |
6eba6a37 | 1824 | if (!(flags & MSG_PEEK)) { |
1da177e4 LT |
1825 | if (UNIXCB(skb).fp) |
1826 | unix_detach_fds(siocb->scm, skb); | |
f55bb7f9 PE |
1827 | |
1828 | sk_peek_offset_bwd(sk, skb->len); | |
6eba6a37 | 1829 | } else { |
1da177e4 LT |
1830 | /* It is questionable: on PEEK we could: |
1831 | - do not return fds - good, but too simple 8) | |
1832 | - return fds, and do not return them on read (old strategy, | |
1833 | apparently wrong) | |
1834 | - clone fds (I chose it for now, it is the most universal | |
1835 | solution) | |
ac7bfa62 YH |
1836 | |
1837 | POSIX 1003.1g does not actually define this clearly | |
1838 | at all. POSIX 1003.1g doesn't define a lot of things | |
1839 | clearly however! | |
1840 | ||
1da177e4 | 1841 | */ |
f55bb7f9 PE |
1842 | |
1843 | sk_peek_offset_fwd(sk, size); | |
1844 | ||
1da177e4 LT |
1845 | if (UNIXCB(skb).fp) |
1846 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1847 | } | |
9f6f9af7 | 1848 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
1da177e4 LT |
1849 | |
1850 | scm_recv(sock, msg, siocb->scm, flags); | |
1851 | ||
1852 | out_free: | |
6eba6a37 | 1853 | skb_free_datagram(sk, skb); |
1da177e4 | 1854 | out_unlock: |
57b47a53 | 1855 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1856 | out: |
1857 | return err; | |
1858 | } | |
1859 | ||
1860 | /* | |
79f632c7 | 1861 | * Sleep until more data has arrived. But check for races.. |
1da177e4 | 1862 | */ |
79f632c7 BP |
1863 | static long unix_stream_data_wait(struct sock *sk, long timeo, |
1864 | struct sk_buff *last) | |
1da177e4 LT |
1865 | { |
1866 | DEFINE_WAIT(wait); | |
1867 | ||
1c92b4e5 | 1868 | unix_state_lock(sk); |
1da177e4 LT |
1869 | |
1870 | for (;;) { | |
aa395145 | 1871 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
1da177e4 | 1872 | |
79f632c7 | 1873 | if (skb_peek_tail(&sk->sk_receive_queue) != last || |
1da177e4 LT |
1874 | sk->sk_err || |
1875 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1876 | signal_pending(current) || | |
1877 | !timeo) | |
1878 | break; | |
1879 | ||
1880 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1881 | unix_state_unlock(sk); |
1da177e4 | 1882 | timeo = schedule_timeout(timeo); |
1c92b4e5 | 1883 | unix_state_lock(sk); |
1da177e4 LT |
1884 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1885 | } | |
1886 | ||
aa395145 | 1887 | finish_wait(sk_sleep(sk), &wait); |
1c92b4e5 | 1888 | unix_state_unlock(sk); |
1da177e4 LT |
1889 | return timeo; |
1890 | } | |
1891 | ||
1da177e4 LT |
1892 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
1893 | struct msghdr *msg, size_t size, | |
1894 | int flags) | |
1895 | { | |
1896 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1897 | struct scm_cookie tmp_scm; | |
1898 | struct sock *sk = sock->sk; | |
1899 | struct unix_sock *u = unix_sk(sk); | |
e27dfcea | 1900 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1901 | int copied = 0; |
1902 | int check_creds = 0; | |
1903 | int target; | |
1904 | int err = 0; | |
1905 | long timeo; | |
fc0d7536 | 1906 | int skip; |
1da177e4 LT |
1907 | |
1908 | err = -EINVAL; | |
1909 | if (sk->sk_state != TCP_ESTABLISHED) | |
1910 | goto out; | |
1911 | ||
1912 | err = -EOPNOTSUPP; | |
1913 | if (flags&MSG_OOB) | |
1914 | goto out; | |
1915 | ||
1916 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1917 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1918 | ||
1919 | msg->msg_namelen = 0; | |
1920 | ||
1921 | /* Lock the socket to prevent queue disordering | |
1922 | * while sleeps in memcpy_tomsg | |
1923 | */ | |
1924 | ||
1925 | if (!siocb->scm) { | |
1926 | siocb->scm = &tmp_scm; | |
1927 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1928 | } | |
1929 | ||
b3ca9b02 RW |
1930 | err = mutex_lock_interruptible(&u->readlock); |
1931 | if (err) { | |
1932 | err = sock_intr_errno(timeo); | |
1933 | goto out; | |
1934 | } | |
1da177e4 | 1935 | |
6eba6a37 | 1936 | do { |
1da177e4 | 1937 | int chunk; |
79f632c7 | 1938 | struct sk_buff *skb, *last; |
1da177e4 | 1939 | |
3c0d2f37 | 1940 | unix_state_lock(sk); |
79f632c7 | 1941 | last = skb = skb_peek(&sk->sk_receive_queue); |
fc0d7536 | 1942 | again: |
6eba6a37 | 1943 | if (skb == NULL) { |
25888e30 | 1944 | unix_sk(sk)->recursion_level = 0; |
1da177e4 | 1945 | if (copied >= target) |
3c0d2f37 | 1946 | goto unlock; |
1da177e4 LT |
1947 | |
1948 | /* | |
1949 | * POSIX 1003.1g mandates this order. | |
1950 | */ | |
ac7bfa62 | 1951 | |
6eba6a37 ED |
1952 | err = sock_error(sk); |
1953 | if (err) | |
3c0d2f37 | 1954 | goto unlock; |
1da177e4 | 1955 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1956 | goto unlock; |
1957 | ||
1958 | unix_state_unlock(sk); | |
1da177e4 LT |
1959 | err = -EAGAIN; |
1960 | if (!timeo) | |
1961 | break; | |
57b47a53 | 1962 | mutex_unlock(&u->readlock); |
1da177e4 | 1963 | |
79f632c7 | 1964 | timeo = unix_stream_data_wait(sk, timeo, last); |
1da177e4 | 1965 | |
b3ca9b02 RW |
1966 | if (signal_pending(current) |
1967 | || mutex_lock_interruptible(&u->readlock)) { | |
1da177e4 LT |
1968 | err = sock_intr_errno(timeo); |
1969 | goto out; | |
1970 | } | |
b3ca9b02 | 1971 | |
1da177e4 | 1972 | continue; |
3c0d2f37 MS |
1973 | unlock: |
1974 | unix_state_unlock(sk); | |
1975 | break; | |
1da177e4 | 1976 | } |
fc0d7536 | 1977 | |
79f632c7 BP |
1978 | skip = sk_peek_offset(sk, flags); |
1979 | while (skip >= skb->len) { | |
fc0d7536 | 1980 | skip -= skb->len; |
79f632c7 | 1981 | last = skb; |
fc0d7536 | 1982 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
79f632c7 BP |
1983 | if (!skb) |
1984 | goto again; | |
fc0d7536 PE |
1985 | } |
1986 | ||
3c0d2f37 | 1987 | unix_state_unlock(sk); |
1da177e4 LT |
1988 | |
1989 | if (check_creds) { | |
1990 | /* Never glue messages from different writers */ | |
7361c36c | 1991 | if ((UNIXCB(skb).pid != siocb->scm->pid) || |
6b0ee8c0 EB |
1992 | !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) || |
1993 | !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid)) | |
1da177e4 | 1994 | break; |
0e82e7f6 | 1995 | } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { |
1da177e4 | 1996 | /* Copy credentials */ |
6b0ee8c0 | 1997 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
1da177e4 LT |
1998 | check_creds = 1; |
1999 | } | |
2000 | ||
2001 | /* Copy address just once */ | |
6eba6a37 | 2002 | if (sunaddr) { |
1da177e4 LT |
2003 | unix_copy_addr(msg, skb->sk); |
2004 | sunaddr = NULL; | |
2005 | } | |
2006 | ||
fc0d7536 PE |
2007 | chunk = min_t(unsigned int, skb->len - skip, size); |
2008 | if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) { | |
1da177e4 LT |
2009 | if (copied == 0) |
2010 | copied = -EFAULT; | |
2011 | break; | |
2012 | } | |
2013 | copied += chunk; | |
2014 | size -= chunk; | |
2015 | ||
2016 | /* Mark read part of skb as used */ | |
6eba6a37 | 2017 | if (!(flags & MSG_PEEK)) { |
1da177e4 LT |
2018 | skb_pull(skb, chunk); |
2019 | ||
fc0d7536 PE |
2020 | sk_peek_offset_bwd(sk, chunk); |
2021 | ||
1da177e4 LT |
2022 | if (UNIXCB(skb).fp) |
2023 | unix_detach_fds(siocb->scm, skb); | |
2024 | ||
6f01fd6e | 2025 | if (skb->len) |
1da177e4 | 2026 | break; |
1da177e4 | 2027 | |
6f01fd6e | 2028 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2029 | consume_skb(skb); |
1da177e4 LT |
2030 | |
2031 | if (siocb->scm->fp) | |
2032 | break; | |
6eba6a37 | 2033 | } else { |
1da177e4 LT |
2034 | /* It is questionable, see note in unix_dgram_recvmsg. |
2035 | */ | |
2036 | if (UNIXCB(skb).fp) | |
2037 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
2038 | ||
fc0d7536 PE |
2039 | sk_peek_offset_fwd(sk, chunk); |
2040 | ||
1da177e4 LT |
2041 | break; |
2042 | } | |
2043 | } while (size); | |
2044 | ||
57b47a53 | 2045 | mutex_unlock(&u->readlock); |
1da177e4 LT |
2046 | scm_recv(sock, msg, siocb->scm, flags); |
2047 | out: | |
2048 | return copied ? : err; | |
2049 | } | |
2050 | ||
2051 | static int unix_shutdown(struct socket *sock, int mode) | |
2052 | { | |
2053 | struct sock *sk = sock->sk; | |
2054 | struct sock *other; | |
2055 | ||
fc61b928 XW |
2056 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
2057 | return -EINVAL; | |
2058 | /* This maps: | |
2059 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2060 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2061 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2062 | */ | |
2063 | ++mode; | |
7180a031 AC |
2064 | |
2065 | unix_state_lock(sk); | |
2066 | sk->sk_shutdown |= mode; | |
2067 | other = unix_peer(sk); | |
2068 | if (other) | |
2069 | sock_hold(other); | |
2070 | unix_state_unlock(sk); | |
2071 | sk->sk_state_change(sk); | |
2072 | ||
2073 | if (other && | |
2074 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2075 | ||
2076 | int peer_mode = 0; | |
2077 | ||
2078 | if (mode&RCV_SHUTDOWN) | |
2079 | peer_mode |= SEND_SHUTDOWN; | |
2080 | if (mode&SEND_SHUTDOWN) | |
2081 | peer_mode |= RCV_SHUTDOWN; | |
2082 | unix_state_lock(other); | |
2083 | other->sk_shutdown |= peer_mode; | |
2084 | unix_state_unlock(other); | |
2085 | other->sk_state_change(other); | |
2086 | if (peer_mode == SHUTDOWN_MASK) | |
2087 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2088 | else if (peer_mode & RCV_SHUTDOWN) | |
2089 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
1da177e4 | 2090 | } |
7180a031 AC |
2091 | if (other) |
2092 | sock_put(other); | |
2093 | ||
1da177e4 LT |
2094 | return 0; |
2095 | } | |
2096 | ||
885ee74d PE |
2097 | long unix_inq_len(struct sock *sk) |
2098 | { | |
2099 | struct sk_buff *skb; | |
2100 | long amount = 0; | |
2101 | ||
2102 | if (sk->sk_state == TCP_LISTEN) | |
2103 | return -EINVAL; | |
2104 | ||
2105 | spin_lock(&sk->sk_receive_queue.lock); | |
2106 | if (sk->sk_type == SOCK_STREAM || | |
2107 | sk->sk_type == SOCK_SEQPACKET) { | |
2108 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
2109 | amount += skb->len; | |
2110 | } else { | |
2111 | skb = skb_peek(&sk->sk_receive_queue); | |
2112 | if (skb) | |
2113 | amount = skb->len; | |
2114 | } | |
2115 | spin_unlock(&sk->sk_receive_queue.lock); | |
2116 | ||
2117 | return amount; | |
2118 | } | |
2119 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2120 | ||
2121 | long unix_outq_len(struct sock *sk) | |
2122 | { | |
2123 | return sk_wmem_alloc_get(sk); | |
2124 | } | |
2125 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2126 | ||
1da177e4 LT |
2127 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
2128 | { | |
2129 | struct sock *sk = sock->sk; | |
e27dfcea | 2130 | long amount = 0; |
1da177e4 LT |
2131 | int err; |
2132 | ||
6eba6a37 ED |
2133 | switch (cmd) { |
2134 | case SIOCOUTQ: | |
885ee74d | 2135 | amount = unix_outq_len(sk); |
6eba6a37 ED |
2136 | err = put_user(amount, (int __user *)arg); |
2137 | break; | |
2138 | case SIOCINQ: | |
885ee74d PE |
2139 | amount = unix_inq_len(sk); |
2140 | if (amount < 0) | |
2141 | err = amount; | |
2142 | else | |
1da177e4 | 2143 | err = put_user(amount, (int __user *)arg); |
885ee74d | 2144 | break; |
6eba6a37 ED |
2145 | default: |
2146 | err = -ENOIOCTLCMD; | |
2147 | break; | |
1da177e4 LT |
2148 | } |
2149 | return err; | |
2150 | } | |
2151 | ||
6eba6a37 | 2152 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
2153 | { |
2154 | struct sock *sk = sock->sk; | |
2155 | unsigned int mask; | |
2156 | ||
aa395145 | 2157 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
2158 | mask = 0; |
2159 | ||
2160 | /* exceptional events? */ | |
2161 | if (sk->sk_err) | |
2162 | mask |= POLLERR; | |
2163 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2164 | mask |= POLLHUP; | |
f348d70a | 2165 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 2166 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
2167 | |
2168 | /* readable? */ | |
db40980f | 2169 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
2170 | mask |= POLLIN | POLLRDNORM; |
2171 | ||
2172 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
2173 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2174 | sk->sk_state == TCP_CLOSE) | |
1da177e4 LT |
2175 | mask |= POLLHUP; |
2176 | ||
2177 | /* | |
2178 | * we set writable also when the other side has shut down the | |
2179 | * connection. This prevents stuck sockets. | |
2180 | */ | |
2181 | if (unix_writable(sk)) | |
2182 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2183 | ||
2184 | return mask; | |
2185 | } | |
2186 | ||
ec0d215f RW |
2187 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2188 | poll_table *wait) | |
3c73419c | 2189 | { |
ec0d215f RW |
2190 | struct sock *sk = sock->sk, *other; |
2191 | unsigned int mask, writable; | |
3c73419c | 2192 | |
aa395145 | 2193 | sock_poll_wait(file, sk_sleep(sk), wait); |
3c73419c RW |
2194 | mask = 0; |
2195 | ||
2196 | /* exceptional events? */ | |
2197 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
7d4c04fc | 2198 | mask |= POLLERR | |
8facd5fb | 2199 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0); |
7d4c04fc | 2200 | |
3c73419c | 2201 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
5456f09a | 2202 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
3c73419c RW |
2203 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2204 | mask |= POLLHUP; | |
2205 | ||
2206 | /* readable? */ | |
5456f09a | 2207 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
3c73419c RW |
2208 | mask |= POLLIN | POLLRDNORM; |
2209 | ||
2210 | /* Connection-based need to check for termination and startup */ | |
2211 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2212 | if (sk->sk_state == TCP_CLOSE) | |
2213 | mask |= POLLHUP; | |
2214 | /* connection hasn't started yet? */ | |
2215 | if (sk->sk_state == TCP_SYN_SENT) | |
2216 | return mask; | |
2217 | } | |
2218 | ||
973a34aa | 2219 | /* No write status requested, avoid expensive OUT tests. */ |
626cf236 | 2220 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
973a34aa ED |
2221 | return mask; |
2222 | ||
ec0d215f | 2223 | writable = unix_writable(sk); |
5456f09a ED |
2224 | other = unix_peer_get(sk); |
2225 | if (other) { | |
2226 | if (unix_peer(other) != sk) { | |
2227 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); | |
2228 | if (unix_recvq_full(other)) | |
2229 | writable = 0; | |
ec0d215f | 2230 | } |
5456f09a | 2231 | sock_put(other); |
ec0d215f RW |
2232 | } |
2233 | ||
2234 | if (writable) | |
3c73419c RW |
2235 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2236 | else | |
2237 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
2238 | ||
3c73419c RW |
2239 | return mask; |
2240 | } | |
1da177e4 LT |
2241 | |
2242 | #ifdef CONFIG_PROC_FS | |
a53eb3fe | 2243 | |
7123aaa3 ED |
2244 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
2245 | ||
2246 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
2247 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) | |
2248 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) | |
a53eb3fe | 2249 | |
7123aaa3 | 2250 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
1da177e4 | 2251 | { |
7123aaa3 ED |
2252 | unsigned long offset = get_offset(*pos); |
2253 | unsigned long bucket = get_bucket(*pos); | |
2254 | struct sock *sk; | |
2255 | unsigned long count = 0; | |
1da177e4 | 2256 | |
7123aaa3 ED |
2257 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { |
2258 | if (sock_net(sk) != seq_file_net(seq)) | |
097e66c5 | 2259 | continue; |
7123aaa3 ED |
2260 | if (++count == offset) |
2261 | break; | |
2262 | } | |
2263 | ||
2264 | return sk; | |
2265 | } | |
2266 | ||
2267 | static struct sock *unix_next_socket(struct seq_file *seq, | |
2268 | struct sock *sk, | |
2269 | loff_t *pos) | |
2270 | { | |
2271 | unsigned long bucket; | |
2272 | ||
2273 | while (sk > (struct sock *)SEQ_START_TOKEN) { | |
2274 | sk = sk_next(sk); | |
2275 | if (!sk) | |
2276 | goto next_bucket; | |
2277 | if (sock_net(sk) == seq_file_net(seq)) | |
2278 | return sk; | |
1da177e4 | 2279 | } |
7123aaa3 ED |
2280 | |
2281 | do { | |
2282 | sk = unix_from_bucket(seq, pos); | |
2283 | if (sk) | |
2284 | return sk; | |
2285 | ||
2286 | next_bucket: | |
2287 | bucket = get_bucket(*pos) + 1; | |
2288 | *pos = set_bucket_offset(bucket, 1); | |
2289 | } while (bucket < ARRAY_SIZE(unix_socket_table)); | |
2290 | ||
1da177e4 LT |
2291 | return NULL; |
2292 | } | |
2293 | ||
1da177e4 | 2294 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
9a429c49 | 2295 | __acquires(unix_table_lock) |
1da177e4 | 2296 | { |
fbe9cc4a | 2297 | spin_lock(&unix_table_lock); |
7123aaa3 ED |
2298 | |
2299 | if (!*pos) | |
2300 | return SEQ_START_TOKEN; | |
2301 | ||
2302 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) | |
2303 | return NULL; | |
2304 | ||
2305 | return unix_next_socket(seq, NULL, pos); | |
1da177e4 LT |
2306 | } |
2307 | ||
2308 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2309 | { | |
2310 | ++*pos; | |
7123aaa3 | 2311 | return unix_next_socket(seq, v, pos); |
1da177e4 LT |
2312 | } |
2313 | ||
2314 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2315 | __releases(unix_table_lock) |
1da177e4 | 2316 | { |
fbe9cc4a | 2317 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2318 | } |
2319 | ||
2320 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2321 | { | |
ac7bfa62 | 2322 | |
b9f3124f | 2323 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
2324 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2325 | "Inode Path\n"); | |
2326 | else { | |
2327 | struct sock *s = v; | |
2328 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2329 | unix_state_lock(s); |
1da177e4 | 2330 | |
71338aa7 | 2331 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 LT |
2332 | s, |
2333 | atomic_read(&s->sk_refcnt), | |
2334 | 0, | |
2335 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2336 | s->sk_type, | |
2337 | s->sk_socket ? | |
2338 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2339 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2340 | sock_i_ino(s)); | |
2341 | ||
2342 | if (u->addr) { | |
2343 | int i, len; | |
2344 | seq_putc(seq, ' '); | |
2345 | ||
2346 | i = 0; | |
2347 | len = u->addr->len - sizeof(short); | |
2348 | if (!UNIX_ABSTRACT(s)) | |
2349 | len--; | |
2350 | else { | |
2351 | seq_putc(seq, '@'); | |
2352 | i++; | |
2353 | } | |
2354 | for ( ; i < len; i++) | |
2355 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2356 | } | |
1c92b4e5 | 2357 | unix_state_unlock(s); |
1da177e4 LT |
2358 | seq_putc(seq, '\n'); |
2359 | } | |
2360 | ||
2361 | return 0; | |
2362 | } | |
2363 | ||
56b3d975 | 2364 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2365 | .start = unix_seq_start, |
2366 | .next = unix_seq_next, | |
2367 | .stop = unix_seq_stop, | |
2368 | .show = unix_seq_show, | |
2369 | }; | |
2370 | ||
1da177e4 LT |
2371 | static int unix_seq_open(struct inode *inode, struct file *file) |
2372 | { | |
e372c414 | 2373 | return seq_open_net(inode, file, &unix_seq_ops, |
8b51b064 | 2374 | sizeof(struct seq_net_private)); |
1da177e4 LT |
2375 | } |
2376 | ||
da7071d7 | 2377 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2378 | .owner = THIS_MODULE, |
2379 | .open = unix_seq_open, | |
2380 | .read = seq_read, | |
2381 | .llseek = seq_lseek, | |
e372c414 | 2382 | .release = seq_release_net, |
1da177e4 LT |
2383 | }; |
2384 | ||
2385 | #endif | |
2386 | ||
ec1b4cf7 | 2387 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
2388 | .family = PF_UNIX, |
2389 | .create = unix_create, | |
2390 | .owner = THIS_MODULE, | |
2391 | }; | |
2392 | ||
097e66c5 | 2393 | |
2c8c1e72 | 2394 | static int __net_init unix_net_init(struct net *net) |
097e66c5 DL |
2395 | { |
2396 | int error = -ENOMEM; | |
2397 | ||
a0a53c8b | 2398 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
2399 | if (unix_sysctl_register(net)) |
2400 | goto out; | |
d392e497 | 2401 | |
097e66c5 | 2402 | #ifdef CONFIG_PROC_FS |
d4beaa66 | 2403 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { |
1597fbc0 | 2404 | unix_sysctl_unregister(net); |
097e66c5 | 2405 | goto out; |
1597fbc0 | 2406 | } |
097e66c5 DL |
2407 | #endif |
2408 | error = 0; | |
2409 | out: | |
48dcc33e | 2410 | return error; |
097e66c5 DL |
2411 | } |
2412 | ||
2c8c1e72 | 2413 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 2414 | { |
1597fbc0 | 2415 | unix_sysctl_unregister(net); |
ece31ffd | 2416 | remove_proc_entry("unix", net->proc_net); |
097e66c5 DL |
2417 | } |
2418 | ||
2419 | static struct pernet_operations unix_net_ops = { | |
2420 | .init = unix_net_init, | |
2421 | .exit = unix_net_exit, | |
2422 | }; | |
2423 | ||
1da177e4 LT |
2424 | static int __init af_unix_init(void) |
2425 | { | |
2426 | int rc = -1; | |
1da177e4 | 2427 | |
b4fff5f8 | 2428 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 LT |
2429 | |
2430 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 YH |
2431 | if (rc != 0) { |
2432 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
0dc47877 | 2433 | __func__); |
1da177e4 LT |
2434 | goto out; |
2435 | } | |
2436 | ||
2437 | sock_register(&unix_family_ops); | |
097e66c5 | 2438 | register_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2439 | out: |
2440 | return rc; | |
2441 | } | |
2442 | ||
2443 | static void __exit af_unix_exit(void) | |
2444 | { | |
2445 | sock_unregister(PF_UNIX); | |
1da177e4 | 2446 | proto_unregister(&unix_proto); |
097e66c5 | 2447 | unregister_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2448 | } |
2449 | ||
3d366960 DW |
2450 | /* Earlier than device_initcall() so that other drivers invoking |
2451 | request_module() don't end up in a loop when modprobe tries | |
2452 | to use a UNIX socket. But later than subsys_initcall() because | |
2453 | we depend on stuff initialised there */ | |
2454 | fs_initcall(af_unix_init); | |
1da177e4 LT |
2455 | module_exit(af_unix_exit); |
2456 | ||
2457 | MODULE_LICENSE("GPL"); | |
2458 | MODULE_ALIAS_NETPROTO(PF_UNIX); |