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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> | |
2b15af6f | 117 | #include <linux/freezer.h> |
1da177e4 | 118 | |
7123aaa3 | 119 | struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; |
fa7ff56f PE |
120 | EXPORT_SYMBOL_GPL(unix_socket_table); |
121 | DEFINE_SPINLOCK(unix_table_lock); | |
122 | EXPORT_SYMBOL_GPL(unix_table_lock); | |
518de9b3 | 123 | static atomic_long_t unix_nr_socks; |
1da177e4 | 124 | |
1da177e4 | 125 | |
7123aaa3 ED |
126 | static struct hlist_head *unix_sockets_unbound(void *addr) |
127 | { | |
128 | unsigned long hash = (unsigned long)addr; | |
129 | ||
130 | hash ^= hash >> 16; | |
131 | hash ^= hash >> 8; | |
132 | hash %= UNIX_HASH_SIZE; | |
133 | return &unix_socket_table[UNIX_HASH_SIZE + hash]; | |
134 | } | |
135 | ||
136 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE) | |
1da177e4 | 137 | |
877ce7c1 | 138 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 139 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 140 | { |
dc49c1f9 | 141 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
877ce7c1 CZ |
142 | } |
143 | ||
144 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
145 | { | |
dc49c1f9 | 146 | scm->secid = *UNIXSID(skb); |
877ce7c1 CZ |
147 | } |
148 | #else | |
dc49c1f9 | 149 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
150 | { } |
151 | ||
152 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
153 | { } | |
154 | #endif /* CONFIG_SECURITY_NETWORK */ | |
155 | ||
1da177e4 LT |
156 | /* |
157 | * SMP locking strategy: | |
fbe9cc4a | 158 | * hash table is protected with spinlock unix_table_lock |
663717f6 | 159 | * each socket state is protected by separate spin lock. |
1da177e4 LT |
160 | */ |
161 | ||
95c96174 | 162 | static inline unsigned int unix_hash_fold(__wsum n) |
1da177e4 | 163 | { |
95c96174 ED |
164 | unsigned int hash = (__force unsigned int)n; |
165 | ||
1da177e4 LT |
166 | hash ^= hash>>16; |
167 | hash ^= hash>>8; | |
168 | return hash&(UNIX_HASH_SIZE-1); | |
169 | } | |
170 | ||
171 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
172 | ||
173 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
174 | { | |
175 | return unix_peer(osk) == sk; | |
176 | } | |
177 | ||
178 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
179 | { | |
6eba6a37 | 180 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
181 | } |
182 | ||
3c73419c RW |
183 | static inline int unix_recvq_full(struct sock const *sk) |
184 | { | |
185 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
186 | } | |
187 | ||
fa7ff56f | 188 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
189 | { |
190 | struct sock *peer; | |
191 | ||
1c92b4e5 | 192 | unix_state_lock(s); |
1da177e4 LT |
193 | peer = unix_peer(s); |
194 | if (peer) | |
195 | sock_hold(peer); | |
1c92b4e5 | 196 | unix_state_unlock(s); |
1da177e4 LT |
197 | return peer; |
198 | } | |
fa7ff56f | 199 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 LT |
200 | |
201 | static inline void unix_release_addr(struct unix_address *addr) | |
202 | { | |
203 | if (atomic_dec_and_test(&addr->refcnt)) | |
204 | kfree(addr); | |
205 | } | |
206 | ||
207 | /* | |
208 | * Check unix socket name: | |
209 | * - should be not zero length. | |
210 | * - if started by not zero, should be NULL terminated (FS object) | |
211 | * - if started by zero, it is abstract name. | |
212 | */ | |
ac7bfa62 | 213 | |
95c96174 | 214 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
1da177e4 LT |
215 | { |
216 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
217 | return -EINVAL; | |
218 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
219 | return -EINVAL; | |
220 | if (sunaddr->sun_path[0]) { | |
221 | /* | |
222 | * This may look like an off by one error but it is a bit more | |
223 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
25985edc | 224 | * sun_path[108] doesn't as such exist. However in kernel space |
1da177e4 LT |
225 | * we are guaranteed that it is a valid memory location in our |
226 | * kernel address buffer. | |
227 | */ | |
e27dfcea | 228 | ((char *)sunaddr)[len] = 0; |
1da177e4 LT |
229 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
230 | return len; | |
231 | } | |
232 | ||
07f0757a | 233 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
1da177e4 LT |
234 | return len; |
235 | } | |
236 | ||
237 | static void __unix_remove_socket(struct sock *sk) | |
238 | { | |
239 | sk_del_node_init(sk); | |
240 | } | |
241 | ||
242 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
243 | { | |
547b792c | 244 | WARN_ON(!sk_unhashed(sk)); |
1da177e4 LT |
245 | sk_add_node(sk, list); |
246 | } | |
247 | ||
248 | static inline void unix_remove_socket(struct sock *sk) | |
249 | { | |
fbe9cc4a | 250 | spin_lock(&unix_table_lock); |
1da177e4 | 251 | __unix_remove_socket(sk); |
fbe9cc4a | 252 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
253 | } |
254 | ||
255 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
256 | { | |
fbe9cc4a | 257 | spin_lock(&unix_table_lock); |
1da177e4 | 258 | __unix_insert_socket(list, sk); |
fbe9cc4a | 259 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
260 | } |
261 | ||
097e66c5 DL |
262 | static struct sock *__unix_find_socket_byname(struct net *net, |
263 | struct sockaddr_un *sunname, | |
95c96174 | 264 | int len, int type, unsigned int hash) |
1da177e4 LT |
265 | { |
266 | struct sock *s; | |
1da177e4 | 267 | |
b67bfe0d | 268 | sk_for_each(s, &unix_socket_table[hash ^ type]) { |
1da177e4 LT |
269 | struct unix_sock *u = unix_sk(s); |
270 | ||
878628fb | 271 | if (!net_eq(sock_net(s), net)) |
097e66c5 DL |
272 | continue; |
273 | ||
1da177e4 LT |
274 | if (u->addr->len == len && |
275 | !memcmp(u->addr->name, sunname, len)) | |
276 | goto found; | |
277 | } | |
278 | s = NULL; | |
279 | found: | |
280 | return s; | |
281 | } | |
282 | ||
097e66c5 DL |
283 | static inline struct sock *unix_find_socket_byname(struct net *net, |
284 | struct sockaddr_un *sunname, | |
1da177e4 | 285 | int len, int type, |
95c96174 | 286 | unsigned int hash) |
1da177e4 LT |
287 | { |
288 | struct sock *s; | |
289 | ||
fbe9cc4a | 290 | spin_lock(&unix_table_lock); |
097e66c5 | 291 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
292 | if (s) |
293 | sock_hold(s); | |
fbe9cc4a | 294 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
295 | return s; |
296 | } | |
297 | ||
6616f788 | 298 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 LT |
299 | { |
300 | struct sock *s; | |
1da177e4 | 301 | |
fbe9cc4a | 302 | spin_lock(&unix_table_lock); |
b67bfe0d | 303 | sk_for_each(s, |
1da177e4 | 304 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
40ffe67d | 305 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 306 | |
6eba6a37 | 307 | if (dentry && dentry->d_inode == i) { |
1da177e4 LT |
308 | sock_hold(s); |
309 | goto found; | |
310 | } | |
311 | } | |
312 | s = NULL; | |
313 | found: | |
fbe9cc4a | 314 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
315 | return s; |
316 | } | |
317 | ||
318 | static inline int unix_writable(struct sock *sk) | |
319 | { | |
320 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
321 | } | |
322 | ||
323 | static void unix_write_space(struct sock *sk) | |
324 | { | |
43815482 ED |
325 | struct socket_wq *wq; |
326 | ||
327 | rcu_read_lock(); | |
1da177e4 | 328 | if (unix_writable(sk)) { |
43815482 ED |
329 | wq = rcu_dereference(sk->sk_wq); |
330 | if (wq_has_sleeper(wq)) | |
67426b75 ED |
331 | wake_up_interruptible_sync_poll(&wq->wait, |
332 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
8d8ad9d7 | 333 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 334 | } |
43815482 | 335 | rcu_read_unlock(); |
1da177e4 LT |
336 | } |
337 | ||
338 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
339 | * queue of packets arrived from previous peer. First, it allows to do | |
340 | * flow control based only on wmem_alloc; second, sk connected to peer | |
341 | * may receive messages only from that peer. */ | |
342 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
343 | { | |
b03efcfb | 344 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
345 | skb_queue_purge(&sk->sk_receive_queue); |
346 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
347 | ||
348 | /* If one link of bidirectional dgram pipe is disconnected, | |
349 | * we signal error. Messages are lost. Do not make this, | |
350 | * when peer was not connected to us. | |
351 | */ | |
352 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
353 | other->sk_err = ECONNRESET; | |
354 | other->sk_error_report(other); | |
355 | } | |
356 | } | |
357 | } | |
358 | ||
359 | static void unix_sock_destructor(struct sock *sk) | |
360 | { | |
361 | struct unix_sock *u = unix_sk(sk); | |
362 | ||
363 | skb_queue_purge(&sk->sk_receive_queue); | |
364 | ||
547b792c IJ |
365 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
366 | WARN_ON(!sk_unhashed(sk)); | |
367 | WARN_ON(sk->sk_socket); | |
1da177e4 | 368 | if (!sock_flag(sk, SOCK_DEAD)) { |
6b41e7dd | 369 | printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
370 | return; |
371 | } | |
372 | ||
373 | if (u->addr) | |
374 | unix_release_addr(u->addr); | |
375 | ||
518de9b3 | 376 | atomic_long_dec(&unix_nr_socks); |
6f756a8c | 377 | local_bh_disable(); |
a8076d8d | 378 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
6f756a8c | 379 | local_bh_enable(); |
1da177e4 | 380 | #ifdef UNIX_REFCNT_DEBUG |
518de9b3 ED |
381 | printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk, |
382 | atomic_long_read(&unix_nr_socks)); | |
1da177e4 LT |
383 | #endif |
384 | } | |
385 | ||
ded34e0f | 386 | static void unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
387 | { |
388 | struct unix_sock *u = unix_sk(sk); | |
40ffe67d | 389 | struct path path; |
1da177e4 LT |
390 | struct sock *skpair; |
391 | struct sk_buff *skb; | |
392 | int state; | |
393 | ||
394 | unix_remove_socket(sk); | |
395 | ||
396 | /* Clear state */ | |
1c92b4e5 | 397 | unix_state_lock(sk); |
1da177e4 LT |
398 | sock_orphan(sk); |
399 | sk->sk_shutdown = SHUTDOWN_MASK; | |
40ffe67d AV |
400 | path = u->path; |
401 | u->path.dentry = NULL; | |
402 | u->path.mnt = NULL; | |
1da177e4 LT |
403 | state = sk->sk_state; |
404 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 405 | unix_state_unlock(sk); |
1da177e4 LT |
406 | |
407 | wake_up_interruptible_all(&u->peer_wait); | |
408 | ||
e27dfcea | 409 | skpair = unix_peer(sk); |
1da177e4 | 410 | |
e27dfcea | 411 | if (skpair != NULL) { |
1da177e4 | 412 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 413 | unix_state_lock(skpair); |
1da177e4 LT |
414 | /* No more writes */ |
415 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
416 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
417 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 418 | unix_state_unlock(skpair); |
1da177e4 | 419 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 420 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 LT |
421 | } |
422 | sock_put(skpair); /* It may now die */ | |
423 | unix_peer(sk) = NULL; | |
424 | } | |
425 | ||
426 | /* Try to flush out this socket. Throw out buffers at least */ | |
427 | ||
428 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 429 | if (state == TCP_LISTEN) |
1da177e4 LT |
430 | unix_release_sock(skb->sk, 1); |
431 | /* passed fds are erased in the kfree_skb hook */ | |
432 | kfree_skb(skb); | |
433 | } | |
434 | ||
40ffe67d AV |
435 | if (path.dentry) |
436 | path_put(&path); | |
1da177e4 LT |
437 | |
438 | sock_put(sk); | |
439 | ||
440 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
441 | ||
442 | /* | |
e04dae84 | 443 | * Fixme: BSD difference: In BSD all sockets connected to us get |
1da177e4 LT |
444 | * ECONNRESET and we die on the spot. In Linux we behave |
445 | * like files and pipes do and wait for the last | |
446 | * dereference. | |
447 | * | |
448 | * Can't we simply set sock->err? | |
449 | * | |
450 | * What the above comment does talk about? --ANK(980817) | |
451 | */ | |
452 | ||
9305cfa4 | 453 | if (unix_tot_inflight) |
ac7bfa62 | 454 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
455 | } |
456 | ||
109f6e39 EB |
457 | static void init_peercred(struct sock *sk) |
458 | { | |
459 | put_pid(sk->sk_peer_pid); | |
460 | if (sk->sk_peer_cred) | |
461 | put_cred(sk->sk_peer_cred); | |
462 | sk->sk_peer_pid = get_pid(task_tgid(current)); | |
463 | sk->sk_peer_cred = get_current_cred(); | |
464 | } | |
465 | ||
466 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
467 | { | |
468 | put_pid(sk->sk_peer_pid); | |
469 | if (sk->sk_peer_cred) | |
470 | put_cred(sk->sk_peer_cred); | |
471 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); | |
472 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
473 | } | |
474 | ||
1da177e4 LT |
475 | static int unix_listen(struct socket *sock, int backlog) |
476 | { | |
477 | int err; | |
478 | struct sock *sk = sock->sk; | |
479 | struct unix_sock *u = unix_sk(sk); | |
109f6e39 | 480 | struct pid *old_pid = NULL; |
1da177e4 LT |
481 | |
482 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
483 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
484 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
485 | err = -EINVAL; |
486 | if (!u->addr) | |
6eba6a37 | 487 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 488 | unix_state_lock(sk); |
1da177e4 LT |
489 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
490 | goto out_unlock; | |
491 | if (backlog > sk->sk_max_ack_backlog) | |
492 | wake_up_interruptible_all(&u->peer_wait); | |
493 | sk->sk_max_ack_backlog = backlog; | |
494 | sk->sk_state = TCP_LISTEN; | |
495 | /* set credentials so connect can copy them */ | |
109f6e39 | 496 | init_peercred(sk); |
1da177e4 LT |
497 | err = 0; |
498 | ||
499 | out_unlock: | |
1c92b4e5 | 500 | unix_state_unlock(sk); |
109f6e39 | 501 | put_pid(old_pid); |
1da177e4 LT |
502 | out: |
503 | return err; | |
504 | } | |
505 | ||
506 | static int unix_release(struct socket *); | |
507 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
508 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
509 | int addr_len, int flags); | |
510 | static int unix_socketpair(struct socket *, struct socket *); | |
511 | static int unix_accept(struct socket *, struct socket *, int); | |
512 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
513 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
ec0d215f RW |
514 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
515 | poll_table *); | |
1da177e4 LT |
516 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
517 | static int unix_shutdown(struct socket *, int); | |
518 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
519 | struct msghdr *, size_t); | |
520 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
521 | struct msghdr *, size_t, int); | |
522 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
523 | struct msghdr *, size_t); | |
524 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
525 | struct msghdr *, size_t, int); | |
526 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
527 | int, int); | |
528 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
529 | struct msghdr *, size_t); | |
a05d2ad1 EB |
530 | static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
531 | struct msghdr *, size_t, int); | |
1da177e4 | 532 | |
f55bb7f9 PE |
533 | static void unix_set_peek_off(struct sock *sk, int val) |
534 | { | |
535 | struct unix_sock *u = unix_sk(sk); | |
536 | ||
537 | mutex_lock(&u->readlock); | |
538 | sk->sk_peek_off = val; | |
539 | mutex_unlock(&u->readlock); | |
540 | } | |
541 | ||
542 | ||
90ddc4f0 | 543 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
544 | .family = PF_UNIX, |
545 | .owner = THIS_MODULE, | |
546 | .release = unix_release, | |
547 | .bind = unix_bind, | |
548 | .connect = unix_stream_connect, | |
549 | .socketpair = unix_socketpair, | |
550 | .accept = unix_accept, | |
551 | .getname = unix_getname, | |
552 | .poll = unix_poll, | |
553 | .ioctl = unix_ioctl, | |
554 | .listen = unix_listen, | |
555 | .shutdown = unix_shutdown, | |
556 | .setsockopt = sock_no_setsockopt, | |
557 | .getsockopt = sock_no_getsockopt, | |
558 | .sendmsg = unix_stream_sendmsg, | |
559 | .recvmsg = unix_stream_recvmsg, | |
560 | .mmap = sock_no_mmap, | |
561 | .sendpage = sock_no_sendpage, | |
fc0d7536 | 562 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
563 | }; |
564 | ||
90ddc4f0 | 565 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
566 | .family = PF_UNIX, |
567 | .owner = THIS_MODULE, | |
568 | .release = unix_release, | |
569 | .bind = unix_bind, | |
570 | .connect = unix_dgram_connect, | |
571 | .socketpair = unix_socketpair, | |
572 | .accept = sock_no_accept, | |
573 | .getname = unix_getname, | |
ec0d215f | 574 | .poll = unix_dgram_poll, |
1da177e4 LT |
575 | .ioctl = unix_ioctl, |
576 | .listen = sock_no_listen, | |
577 | .shutdown = unix_shutdown, | |
578 | .setsockopt = sock_no_setsockopt, | |
579 | .getsockopt = sock_no_getsockopt, | |
580 | .sendmsg = unix_dgram_sendmsg, | |
581 | .recvmsg = unix_dgram_recvmsg, | |
582 | .mmap = sock_no_mmap, | |
583 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 584 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
585 | }; |
586 | ||
90ddc4f0 | 587 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
588 | .family = PF_UNIX, |
589 | .owner = THIS_MODULE, | |
590 | .release = unix_release, | |
591 | .bind = unix_bind, | |
592 | .connect = unix_stream_connect, | |
593 | .socketpair = unix_socketpair, | |
594 | .accept = unix_accept, | |
595 | .getname = unix_getname, | |
ec0d215f | 596 | .poll = unix_dgram_poll, |
1da177e4 LT |
597 | .ioctl = unix_ioctl, |
598 | .listen = unix_listen, | |
599 | .shutdown = unix_shutdown, | |
600 | .setsockopt = sock_no_setsockopt, | |
601 | .getsockopt = sock_no_getsockopt, | |
602 | .sendmsg = unix_seqpacket_sendmsg, | |
a05d2ad1 | 603 | .recvmsg = unix_seqpacket_recvmsg, |
1da177e4 LT |
604 | .mmap = sock_no_mmap, |
605 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 606 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
607 | }; |
608 | ||
609 | static struct proto unix_proto = { | |
248969ae ED |
610 | .name = "UNIX", |
611 | .owner = THIS_MODULE, | |
248969ae | 612 | .obj_size = sizeof(struct unix_sock), |
1da177e4 LT |
613 | }; |
614 | ||
a09785a2 IM |
615 | /* |
616 | * AF_UNIX sockets do not interact with hardware, hence they | |
617 | * dont trigger interrupts - so it's safe for them to have | |
618 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
619 | * this special lock-class by reinitializing the spinlock key: | |
620 | */ | |
621 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
622 | ||
6eba6a37 | 623 | static struct sock *unix_create1(struct net *net, struct socket *sock) |
1da177e4 LT |
624 | { |
625 | struct sock *sk = NULL; | |
626 | struct unix_sock *u; | |
627 | ||
518de9b3 ED |
628 | atomic_long_inc(&unix_nr_socks); |
629 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) | |
1da177e4 LT |
630 | goto out; |
631 | ||
6257ff21 | 632 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
1da177e4 LT |
633 | if (!sk) |
634 | goto out; | |
635 | ||
6eba6a37 | 636 | sock_init_data(sock, sk); |
a09785a2 IM |
637 | lockdep_set_class(&sk->sk_receive_queue.lock, |
638 | &af_unix_sk_receive_queue_lock_key); | |
1da177e4 LT |
639 | |
640 | sk->sk_write_space = unix_write_space; | |
a0a53c8b | 641 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
1da177e4 LT |
642 | sk->sk_destruct = unix_sock_destructor; |
643 | u = unix_sk(sk); | |
40ffe67d AV |
644 | u->path.dentry = NULL; |
645 | u->path.mnt = NULL; | |
fd19f329 | 646 | spin_lock_init(&u->lock); |
516e0cc5 | 647 | atomic_long_set(&u->inflight, 0); |
1fd05ba5 | 648 | INIT_LIST_HEAD(&u->link); |
57b47a53 | 649 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 | 650 | init_waitqueue_head(&u->peer_wait); |
7123aaa3 | 651 | unix_insert_socket(unix_sockets_unbound(sk), sk); |
1da177e4 | 652 | out: |
284b327b | 653 | if (sk == NULL) |
518de9b3 | 654 | atomic_long_dec(&unix_nr_socks); |
920de804 ED |
655 | else { |
656 | local_bh_disable(); | |
a8076d8d | 657 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
920de804 ED |
658 | local_bh_enable(); |
659 | } | |
1da177e4 LT |
660 | return sk; |
661 | } | |
662 | ||
3f378b68 EP |
663 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
664 | int kern) | |
1da177e4 LT |
665 | { |
666 | if (protocol && protocol != PF_UNIX) | |
667 | return -EPROTONOSUPPORT; | |
668 | ||
669 | sock->state = SS_UNCONNECTED; | |
670 | ||
671 | switch (sock->type) { | |
672 | case SOCK_STREAM: | |
673 | sock->ops = &unix_stream_ops; | |
674 | break; | |
675 | /* | |
676 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
677 | * nothing uses it. | |
678 | */ | |
679 | case SOCK_RAW: | |
e27dfcea | 680 | sock->type = SOCK_DGRAM; |
1da177e4 LT |
681 | case SOCK_DGRAM: |
682 | sock->ops = &unix_dgram_ops; | |
683 | break; | |
684 | case SOCK_SEQPACKET: | |
685 | sock->ops = &unix_seqpacket_ops; | |
686 | break; | |
687 | default: | |
688 | return -ESOCKTNOSUPPORT; | |
689 | } | |
690 | ||
1b8d7ae4 | 691 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
1da177e4 LT |
692 | } |
693 | ||
694 | static int unix_release(struct socket *sock) | |
695 | { | |
696 | struct sock *sk = sock->sk; | |
697 | ||
698 | if (!sk) | |
699 | return 0; | |
700 | ||
ded34e0f | 701 | unix_release_sock(sk, 0); |
1da177e4 LT |
702 | sock->sk = NULL; |
703 | ||
ded34e0f | 704 | return 0; |
1da177e4 LT |
705 | } |
706 | ||
707 | static int unix_autobind(struct socket *sock) | |
708 | { | |
709 | struct sock *sk = sock->sk; | |
3b1e0a65 | 710 | struct net *net = sock_net(sk); |
1da177e4 LT |
711 | struct unix_sock *u = unix_sk(sk); |
712 | static u32 ordernum = 1; | |
6eba6a37 | 713 | struct unix_address *addr; |
1da177e4 | 714 | int err; |
8df73ff9 | 715 | unsigned int retries = 0; |
1da177e4 | 716 | |
57b47a53 | 717 | mutex_lock(&u->readlock); |
1da177e4 LT |
718 | |
719 | err = 0; | |
720 | if (u->addr) | |
721 | goto out; | |
722 | ||
723 | err = -ENOMEM; | |
0da974f4 | 724 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
725 | if (!addr) |
726 | goto out; | |
727 | ||
1da177e4 LT |
728 | addr->name->sun_family = AF_UNIX; |
729 | atomic_set(&addr->refcnt, 1); | |
730 | ||
731 | retry: | |
732 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
07f0757a | 733 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
1da177e4 | 734 | |
fbe9cc4a | 735 | spin_lock(&unix_table_lock); |
1da177e4 LT |
736 | ordernum = (ordernum+1)&0xFFFFF; |
737 | ||
097e66c5 | 738 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
1da177e4 | 739 | addr->hash)) { |
fbe9cc4a | 740 | spin_unlock(&unix_table_lock); |
8df73ff9 TH |
741 | /* |
742 | * __unix_find_socket_byname() may take long time if many names | |
743 | * are already in use. | |
744 | */ | |
745 | cond_resched(); | |
746 | /* Give up if all names seems to be in use. */ | |
747 | if (retries++ == 0xFFFFF) { | |
748 | err = -ENOSPC; | |
749 | kfree(addr); | |
750 | goto out; | |
751 | } | |
1da177e4 LT |
752 | goto retry; |
753 | } | |
754 | addr->hash ^= sk->sk_type; | |
755 | ||
756 | __unix_remove_socket(sk); | |
757 | u->addr = addr; | |
758 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 759 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
760 | err = 0; |
761 | ||
57b47a53 | 762 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
763 | return err; |
764 | } | |
765 | ||
097e66c5 DL |
766 | static struct sock *unix_find_other(struct net *net, |
767 | struct sockaddr_un *sunname, int len, | |
95c96174 | 768 | int type, unsigned int hash, int *error) |
1da177e4 LT |
769 | { |
770 | struct sock *u; | |
421748ec | 771 | struct path path; |
1da177e4 | 772 | int err = 0; |
ac7bfa62 | 773 | |
1da177e4 | 774 | if (sunname->sun_path[0]) { |
421748ec AV |
775 | struct inode *inode; |
776 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
1da177e4 LT |
777 | if (err) |
778 | goto fail; | |
421748ec AV |
779 | inode = path.dentry->d_inode; |
780 | err = inode_permission(inode, MAY_WRITE); | |
1da177e4 LT |
781 | if (err) |
782 | goto put_fail; | |
783 | ||
784 | err = -ECONNREFUSED; | |
421748ec | 785 | if (!S_ISSOCK(inode->i_mode)) |
1da177e4 | 786 | goto put_fail; |
6616f788 | 787 | u = unix_find_socket_byinode(inode); |
1da177e4 LT |
788 | if (!u) |
789 | goto put_fail; | |
790 | ||
791 | if (u->sk_type == type) | |
68ac1234 | 792 | touch_atime(&path); |
1da177e4 | 793 | |
421748ec | 794 | path_put(&path); |
1da177e4 | 795 | |
e27dfcea | 796 | err = -EPROTOTYPE; |
1da177e4 LT |
797 | if (u->sk_type != type) { |
798 | sock_put(u); | |
799 | goto fail; | |
800 | } | |
801 | } else { | |
802 | err = -ECONNREFUSED; | |
e27dfcea | 803 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
804 | if (u) { |
805 | struct dentry *dentry; | |
40ffe67d | 806 | dentry = unix_sk(u)->path.dentry; |
1da177e4 | 807 | if (dentry) |
68ac1234 | 808 | touch_atime(&unix_sk(u)->path); |
1da177e4 LT |
809 | } else |
810 | goto fail; | |
811 | } | |
812 | return u; | |
813 | ||
814 | put_fail: | |
421748ec | 815 | path_put(&path); |
1da177e4 | 816 | fail: |
e27dfcea | 817 | *error = err; |
1da177e4 LT |
818 | return NULL; |
819 | } | |
820 | ||
faf02010 AV |
821 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) |
822 | { | |
823 | struct dentry *dentry; | |
824 | struct path path; | |
825 | int err = 0; | |
826 | /* | |
827 | * Get the parent directory, calculate the hash for last | |
828 | * component. | |
829 | */ | |
830 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); | |
831 | err = PTR_ERR(dentry); | |
832 | if (IS_ERR(dentry)) | |
833 | return err; | |
834 | ||
835 | /* | |
836 | * All right, let's create it. | |
837 | */ | |
838 | err = security_path_mknod(&path, dentry, mode, 0); | |
839 | if (!err) { | |
840 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); | |
841 | if (!err) { | |
842 | res->mnt = mntget(path.mnt); | |
843 | res->dentry = dget(dentry); | |
844 | } | |
845 | } | |
846 | done_path_create(&path, dentry); | |
847 | return err; | |
848 | } | |
1da177e4 LT |
849 | |
850 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
851 | { | |
852 | struct sock *sk = sock->sk; | |
3b1e0a65 | 853 | struct net *net = sock_net(sk); |
1da177e4 | 854 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 855 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
dae6ad8f | 856 | char *sun_path = sunaddr->sun_path; |
1da177e4 | 857 | int err; |
95c96174 | 858 | unsigned int hash; |
1da177e4 LT |
859 | struct unix_address *addr; |
860 | struct hlist_head *list; | |
861 | ||
862 | err = -EINVAL; | |
863 | if (sunaddr->sun_family != AF_UNIX) | |
864 | goto out; | |
865 | ||
e27dfcea | 866 | if (addr_len == sizeof(short)) { |
1da177e4 LT |
867 | err = unix_autobind(sock); |
868 | goto out; | |
869 | } | |
870 | ||
871 | err = unix_mkname(sunaddr, addr_len, &hash); | |
872 | if (err < 0) | |
873 | goto out; | |
874 | addr_len = err; | |
875 | ||
57b47a53 | 876 | mutex_lock(&u->readlock); |
1da177e4 LT |
877 | |
878 | err = -EINVAL; | |
879 | if (u->addr) | |
880 | goto out_up; | |
881 | ||
882 | err = -ENOMEM; | |
883 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
884 | if (!addr) | |
885 | goto out_up; | |
886 | ||
887 | memcpy(addr->name, sunaddr, addr_len); | |
888 | addr->len = addr_len; | |
889 | addr->hash = hash ^ sk->sk_type; | |
890 | atomic_set(&addr->refcnt, 1); | |
891 | ||
dae6ad8f | 892 | if (sun_path[0]) { |
faf02010 AV |
893 | struct path path; |
894 | umode_t mode = S_IFSOCK | | |
ce3b0f8d | 895 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
faf02010 AV |
896 | err = unix_mknod(sun_path, mode, &path); |
897 | if (err) { | |
898 | if (err == -EEXIST) | |
899 | err = -EADDRINUSE; | |
900 | unix_release_addr(addr); | |
901 | goto out_up; | |
902 | } | |
1da177e4 | 903 | addr->hash = UNIX_HASH_SIZE; |
faf02010 AV |
904 | hash = path.dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1); |
905 | spin_lock(&unix_table_lock); | |
906 | u->path = path; | |
907 | list = &unix_socket_table[hash]; | |
908 | } else { | |
909 | spin_lock(&unix_table_lock); | |
1da177e4 | 910 | err = -EADDRINUSE; |
097e66c5 | 911 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
1da177e4 LT |
912 | sk->sk_type, hash)) { |
913 | unix_release_addr(addr); | |
914 | goto out_unlock; | |
915 | } | |
916 | ||
917 | list = &unix_socket_table[addr->hash]; | |
1da177e4 LT |
918 | } |
919 | ||
920 | err = 0; | |
921 | __unix_remove_socket(sk); | |
922 | u->addr = addr; | |
923 | __unix_insert_socket(list, sk); | |
924 | ||
925 | out_unlock: | |
fbe9cc4a | 926 | spin_unlock(&unix_table_lock); |
1da177e4 | 927 | out_up: |
57b47a53 | 928 | mutex_unlock(&u->readlock); |
1da177e4 LT |
929 | out: |
930 | return err; | |
1da177e4 LT |
931 | } |
932 | ||
278a3de5 DM |
933 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
934 | { | |
935 | if (unlikely(sk1 == sk2) || !sk2) { | |
936 | unix_state_lock(sk1); | |
937 | return; | |
938 | } | |
939 | if (sk1 < sk2) { | |
940 | unix_state_lock(sk1); | |
941 | unix_state_lock_nested(sk2); | |
942 | } else { | |
943 | unix_state_lock(sk2); | |
944 | unix_state_lock_nested(sk1); | |
945 | } | |
946 | } | |
947 | ||
948 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
949 | { | |
950 | if (unlikely(sk1 == sk2) || !sk2) { | |
951 | unix_state_unlock(sk1); | |
952 | return; | |
953 | } | |
954 | unix_state_unlock(sk1); | |
955 | unix_state_unlock(sk2); | |
956 | } | |
957 | ||
1da177e4 LT |
958 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
959 | int alen, int flags) | |
960 | { | |
961 | struct sock *sk = sock->sk; | |
3b1e0a65 | 962 | struct net *net = sock_net(sk); |
e27dfcea | 963 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
1da177e4 | 964 | struct sock *other; |
95c96174 | 965 | unsigned int hash; |
1da177e4 LT |
966 | int err; |
967 | ||
968 | if (addr->sa_family != AF_UNSPEC) { | |
969 | err = unix_mkname(sunaddr, alen, &hash); | |
970 | if (err < 0) | |
971 | goto out; | |
972 | alen = err; | |
973 | ||
974 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
975 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
976 | goto out; | |
977 | ||
278a3de5 | 978 | restart: |
e27dfcea | 979 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
1da177e4 LT |
980 | if (!other) |
981 | goto out; | |
982 | ||
278a3de5 DM |
983 | unix_state_double_lock(sk, other); |
984 | ||
985 | /* Apparently VFS overslept socket death. Retry. */ | |
986 | if (sock_flag(other, SOCK_DEAD)) { | |
987 | unix_state_double_unlock(sk, other); | |
988 | sock_put(other); | |
989 | goto restart; | |
990 | } | |
1da177e4 LT |
991 | |
992 | err = -EPERM; | |
993 | if (!unix_may_send(sk, other)) | |
994 | goto out_unlock; | |
995 | ||
996 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
997 | if (err) | |
998 | goto out_unlock; | |
999 | ||
1000 | } else { | |
1001 | /* | |
1002 | * 1003.1g breaking connected state with AF_UNSPEC | |
1003 | */ | |
1004 | other = NULL; | |
278a3de5 | 1005 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1006 | } |
1007 | ||
1008 | /* | |
1009 | * If it was connected, reconnect. | |
1010 | */ | |
1011 | if (unix_peer(sk)) { | |
1012 | struct sock *old_peer = unix_peer(sk); | |
e27dfcea | 1013 | unix_peer(sk) = other; |
278a3de5 | 1014 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1015 | |
1016 | if (other != old_peer) | |
1017 | unix_dgram_disconnected(sk, old_peer); | |
1018 | sock_put(old_peer); | |
1019 | } else { | |
e27dfcea | 1020 | unix_peer(sk) = other; |
278a3de5 | 1021 | unix_state_double_unlock(sk, other); |
1da177e4 | 1022 | } |
ac7bfa62 | 1023 | return 0; |
1da177e4 LT |
1024 | |
1025 | out_unlock: | |
278a3de5 | 1026 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1027 | sock_put(other); |
1028 | out: | |
1029 | return err; | |
1030 | } | |
1031 | ||
1032 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1033 | { | |
1034 | struct unix_sock *u = unix_sk(other); | |
1035 | int sched; | |
1036 | DEFINE_WAIT(wait); | |
1037 | ||
1038 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1039 | ||
1040 | sched = !sock_flag(other, SOCK_DEAD) && | |
1041 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
3c73419c | 1042 | unix_recvq_full(other); |
1da177e4 | 1043 | |
1c92b4e5 | 1044 | unix_state_unlock(other); |
1da177e4 LT |
1045 | |
1046 | if (sched) | |
1047 | timeo = schedule_timeout(timeo); | |
1048 | ||
1049 | finish_wait(&u->peer_wait, &wait); | |
1050 | return timeo; | |
1051 | } | |
1052 | ||
1053 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1054 | int addr_len, int flags) | |
1055 | { | |
e27dfcea | 1056 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1da177e4 | 1057 | struct sock *sk = sock->sk; |
3b1e0a65 | 1058 | struct net *net = sock_net(sk); |
1da177e4 LT |
1059 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1060 | struct sock *newsk = NULL; | |
1061 | struct sock *other = NULL; | |
1062 | struct sk_buff *skb = NULL; | |
95c96174 | 1063 | unsigned int hash; |
1da177e4 LT |
1064 | int st; |
1065 | int err; | |
1066 | long timeo; | |
1067 | ||
1068 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1069 | if (err < 0) | |
1070 | goto out; | |
1071 | addr_len = err; | |
1072 | ||
f64f9e71 JP |
1073 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
1074 | (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1075 | goto out; |
1076 | ||
1077 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1078 | ||
1079 | /* First of all allocate resources. | |
1080 | If we will make it after state is locked, | |
1081 | we will have to recheck all again in any case. | |
1082 | */ | |
1083 | ||
1084 | err = -ENOMEM; | |
1085 | ||
1086 | /* create new sock for complete connection */ | |
3b1e0a65 | 1087 | newsk = unix_create1(sock_net(sk), NULL); |
1da177e4 LT |
1088 | if (newsk == NULL) |
1089 | goto out; | |
1090 | ||
1091 | /* Allocate skb for sending to listening sock */ | |
1092 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1093 | if (skb == NULL) | |
1094 | goto out; | |
1095 | ||
1096 | restart: | |
1097 | /* Find listening sock. */ | |
097e66c5 | 1098 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1da177e4 LT |
1099 | if (!other) |
1100 | goto out; | |
1101 | ||
1102 | /* Latch state of peer */ | |
1c92b4e5 | 1103 | unix_state_lock(other); |
1da177e4 LT |
1104 | |
1105 | /* Apparently VFS overslept socket death. Retry. */ | |
1106 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1107 | unix_state_unlock(other); |
1da177e4 LT |
1108 | sock_put(other); |
1109 | goto restart; | |
1110 | } | |
1111 | ||
1112 | err = -ECONNREFUSED; | |
1113 | if (other->sk_state != TCP_LISTEN) | |
1114 | goto out_unlock; | |
77238f2b TS |
1115 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1116 | goto out_unlock; | |
1da177e4 | 1117 | |
3c73419c | 1118 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1119 | err = -EAGAIN; |
1120 | if (!timeo) | |
1121 | goto out_unlock; | |
1122 | ||
1123 | timeo = unix_wait_for_peer(other, timeo); | |
1124 | ||
1125 | err = sock_intr_errno(timeo); | |
1126 | if (signal_pending(current)) | |
1127 | goto out; | |
1128 | sock_put(other); | |
1129 | goto restart; | |
ac7bfa62 | 1130 | } |
1da177e4 LT |
1131 | |
1132 | /* Latch our state. | |
1133 | ||
e5537bfc | 1134 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1135 | drop lock on peer. It is dangerous because deadlock is |
1136 | possible. Connect to self case and simultaneous | |
1137 | attempt to connect are eliminated by checking socket | |
1138 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1139 | check this before attempt to grab lock. | |
1140 | ||
1141 | Well, and we have to recheck the state after socket locked. | |
1142 | */ | |
1143 | st = sk->sk_state; | |
1144 | ||
1145 | switch (st) { | |
1146 | case TCP_CLOSE: | |
1147 | /* This is ok... continue with connect */ | |
1148 | break; | |
1149 | case TCP_ESTABLISHED: | |
1150 | /* Socket is already connected */ | |
1151 | err = -EISCONN; | |
1152 | goto out_unlock; | |
1153 | default: | |
1154 | err = -EINVAL; | |
1155 | goto out_unlock; | |
1156 | } | |
1157 | ||
1c92b4e5 | 1158 | unix_state_lock_nested(sk); |
1da177e4 LT |
1159 | |
1160 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1161 | unix_state_unlock(sk); |
1162 | unix_state_unlock(other); | |
1da177e4 LT |
1163 | sock_put(other); |
1164 | goto restart; | |
1165 | } | |
1166 | ||
3610cda5 | 1167 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1168 | if (err) { |
1c92b4e5 | 1169 | unix_state_unlock(sk); |
1da177e4 LT |
1170 | goto out_unlock; |
1171 | } | |
1172 | ||
1173 | /* The way is open! Fastly set all the necessary fields... */ | |
1174 | ||
1175 | sock_hold(sk); | |
1176 | unix_peer(newsk) = sk; | |
1177 | newsk->sk_state = TCP_ESTABLISHED; | |
1178 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1179 | init_peercred(newsk); |
1da177e4 | 1180 | newu = unix_sk(newsk); |
eaefd110 | 1181 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1182 | otheru = unix_sk(other); |
1183 | ||
1184 | /* copy address information from listening to new sock*/ | |
1185 | if (otheru->addr) { | |
1186 | atomic_inc(&otheru->addr->refcnt); | |
1187 | newu->addr = otheru->addr; | |
1188 | } | |
40ffe67d AV |
1189 | if (otheru->path.dentry) { |
1190 | path_get(&otheru->path); | |
1191 | newu->path = otheru->path; | |
1da177e4 LT |
1192 | } |
1193 | ||
1194 | /* Set credentials */ | |
109f6e39 | 1195 | copy_peercred(sk, other); |
1da177e4 | 1196 | |
1da177e4 LT |
1197 | sock->state = SS_CONNECTED; |
1198 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1199 | sock_hold(newsk); |
1200 | ||
1201 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1202 | unix_peer(sk) = newsk; | |
1da177e4 | 1203 | |
1c92b4e5 | 1204 | unix_state_unlock(sk); |
1da177e4 LT |
1205 | |
1206 | /* take ten and and send info to listening sock */ | |
1207 | spin_lock(&other->sk_receive_queue.lock); | |
1208 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1209 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1210 | unix_state_unlock(other); |
1da177e4 LT |
1211 | other->sk_data_ready(other, 0); |
1212 | sock_put(other); | |
1213 | return 0; | |
1214 | ||
1215 | out_unlock: | |
1216 | if (other) | |
1c92b4e5 | 1217 | unix_state_unlock(other); |
1da177e4 LT |
1218 | |
1219 | out: | |
40d44446 | 1220 | kfree_skb(skb); |
1da177e4 LT |
1221 | if (newsk) |
1222 | unix_release_sock(newsk, 0); | |
1223 | if (other) | |
1224 | sock_put(other); | |
1225 | return err; | |
1226 | } | |
1227 | ||
1228 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1229 | { | |
e27dfcea | 1230 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1231 | |
1232 | /* Join our sockets back to back */ | |
1233 | sock_hold(ska); | |
1234 | sock_hold(skb); | |
e27dfcea JK |
1235 | unix_peer(ska) = skb; |
1236 | unix_peer(skb) = ska; | |
109f6e39 EB |
1237 | init_peercred(ska); |
1238 | init_peercred(skb); | |
1da177e4 LT |
1239 | |
1240 | if (ska->sk_type != SOCK_DGRAM) { | |
1241 | ska->sk_state = TCP_ESTABLISHED; | |
1242 | skb->sk_state = TCP_ESTABLISHED; | |
1243 | socka->state = SS_CONNECTED; | |
1244 | sockb->state = SS_CONNECTED; | |
1245 | } | |
1246 | return 0; | |
1247 | } | |
1248 | ||
90c6bd34 DB |
1249 | static void unix_sock_inherit_flags(const struct socket *old, |
1250 | struct socket *new) | |
1251 | { | |
1252 | if (test_bit(SOCK_PASSCRED, &old->flags)) | |
1253 | set_bit(SOCK_PASSCRED, &new->flags); | |
1254 | if (test_bit(SOCK_PASSSEC, &old->flags)) | |
1255 | set_bit(SOCK_PASSSEC, &new->flags); | |
1256 | } | |
1257 | ||
1da177e4 LT |
1258 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
1259 | { | |
1260 | struct sock *sk = sock->sk; | |
1261 | struct sock *tsk; | |
1262 | struct sk_buff *skb; | |
1263 | int err; | |
1264 | ||
1265 | err = -EOPNOTSUPP; | |
6eba6a37 | 1266 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1267 | goto out; |
1268 | ||
1269 | err = -EINVAL; | |
1270 | if (sk->sk_state != TCP_LISTEN) | |
1271 | goto out; | |
1272 | ||
1273 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1274 | * so that no locks are necessary. | |
1275 | */ | |
1276 | ||
1277 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1278 | if (!skb) { | |
1279 | /* This means receive shutdown. */ | |
1280 | if (err == 0) | |
1281 | err = -EINVAL; | |
1282 | goto out; | |
1283 | } | |
1284 | ||
1285 | tsk = skb->sk; | |
1286 | skb_free_datagram(sk, skb); | |
1287 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1288 | ||
1289 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1290 | unix_state_lock(tsk); |
1da177e4 | 1291 | newsock->state = SS_CONNECTED; |
90c6bd34 | 1292 | unix_sock_inherit_flags(sock, newsock); |
1da177e4 | 1293 | sock_graft(tsk, newsock); |
1c92b4e5 | 1294 | unix_state_unlock(tsk); |
1da177e4 LT |
1295 | return 0; |
1296 | ||
1297 | out: | |
1298 | return err; | |
1299 | } | |
1300 | ||
1301 | ||
1302 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1303 | { | |
1304 | struct sock *sk = sock->sk; | |
1305 | struct unix_sock *u; | |
13cfa97b | 1306 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1307 | int err = 0; |
1308 | ||
1309 | if (peer) { | |
1310 | sk = unix_peer_get(sk); | |
1311 | ||
1312 | err = -ENOTCONN; | |
1313 | if (!sk) | |
1314 | goto out; | |
1315 | err = 0; | |
1316 | } else { | |
1317 | sock_hold(sk); | |
1318 | } | |
1319 | ||
1320 | u = unix_sk(sk); | |
1c92b4e5 | 1321 | unix_state_lock(sk); |
1da177e4 LT |
1322 | if (!u->addr) { |
1323 | sunaddr->sun_family = AF_UNIX; | |
1324 | sunaddr->sun_path[0] = 0; | |
1325 | *uaddr_len = sizeof(short); | |
1326 | } else { | |
1327 | struct unix_address *addr = u->addr; | |
1328 | ||
1329 | *uaddr_len = addr->len; | |
1330 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1331 | } | |
1c92b4e5 | 1332 | unix_state_unlock(sk); |
1da177e4 LT |
1333 | sock_put(sk); |
1334 | out: | |
1335 | return err; | |
1336 | } | |
1337 | ||
1338 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1339 | { | |
1340 | int i; | |
1341 | ||
1342 | scm->fp = UNIXCB(skb).fp; | |
1da177e4 LT |
1343 | UNIXCB(skb).fp = NULL; |
1344 | ||
6eba6a37 | 1345 | for (i = scm->fp->count-1; i >= 0; i--) |
1da177e4 LT |
1346 | unix_notinflight(scm->fp->fp[i]); |
1347 | } | |
1348 | ||
7361c36c | 1349 | static void unix_destruct_scm(struct sk_buff *skb) |
1da177e4 LT |
1350 | { |
1351 | struct scm_cookie scm; | |
1352 | memset(&scm, 0, sizeof(scm)); | |
7361c36c | 1353 | scm.pid = UNIXCB(skb).pid; |
7361c36c EB |
1354 | if (UNIXCB(skb).fp) |
1355 | unix_detach_fds(&scm, skb); | |
1da177e4 LT |
1356 | |
1357 | /* Alas, it calls VFS */ | |
1358 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1359 | scm_destroy(&scm); | |
1360 | sock_wfree(skb); | |
1361 | } | |
1362 | ||
25888e30 ED |
1363 | #define MAX_RECURSION_LEVEL 4 |
1364 | ||
6209344f | 1365 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1da177e4 LT |
1366 | { |
1367 | int i; | |
25888e30 ED |
1368 | unsigned char max_level = 0; |
1369 | int unix_sock_count = 0; | |
1370 | ||
1371 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1372 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1373 | ||
1374 | if (sk) { | |
1375 | unix_sock_count++; | |
1376 | max_level = max(max_level, | |
1377 | unix_sk(sk)->recursion_level); | |
1378 | } | |
1379 | } | |
1380 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1381 | return -ETOOMANYREFS; | |
6209344f MS |
1382 | |
1383 | /* | |
1384 | * Need to duplicate file references for the sake of garbage | |
1385 | * collection. Otherwise a socket in the fps might become a | |
1386 | * candidate for GC while the skb is not yet queued. | |
1387 | */ | |
1388 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1389 | if (!UNIXCB(skb).fp) | |
1390 | return -ENOMEM; | |
1391 | ||
25888e30 ED |
1392 | if (unix_sock_count) { |
1393 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1394 | unix_inflight(scm->fp->fp[i]); | |
1395 | } | |
1396 | return max_level; | |
1da177e4 LT |
1397 | } |
1398 | ||
f78a5fda | 1399 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1400 | { |
1401 | int err = 0; | |
16e57262 | 1402 | |
f78a5fda | 1403 | UNIXCB(skb).pid = get_pid(scm->pid); |
6b0ee8c0 EB |
1404 | UNIXCB(skb).uid = scm->creds.uid; |
1405 | UNIXCB(skb).gid = scm->creds.gid; | |
7361c36c EB |
1406 | UNIXCB(skb).fp = NULL; |
1407 | if (scm->fp && send_fds) | |
1408 | err = unix_attach_fds(scm, skb); | |
1409 | ||
1410 | skb->destructor = unix_destruct_scm; | |
1411 | return err; | |
1412 | } | |
1413 | ||
16e57262 ED |
1414 | /* |
1415 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1416 | * We include credentials if source or destination socket | |
1417 | * asserted SOCK_PASSCRED. | |
1418 | */ | |
1419 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1420 | const struct sock *other) | |
1421 | { | |
6b0ee8c0 | 1422 | if (UNIXCB(skb).pid) |
16e57262 ED |
1423 | return; |
1424 | if (test_bit(SOCK_PASSCRED, &sock->flags) || | |
25da0e3e EB |
1425 | !other->sk_socket || |
1426 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { | |
16e57262 | 1427 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
6e0895c2 | 1428 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); |
16e57262 ED |
1429 | } |
1430 | } | |
1431 | ||
1da177e4 LT |
1432 | /* |
1433 | * Send AF_UNIX data. | |
1434 | */ | |
1435 | ||
1436 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1437 | struct msghdr *msg, size_t len) | |
1438 | { | |
1439 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1440 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1441 | struct net *net = sock_net(sk); |
1da177e4 | 1442 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 1443 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1444 | struct sock *other = NULL; |
1445 | int namelen = 0; /* fake GCC */ | |
1446 | int err; | |
95c96174 | 1447 | unsigned int hash; |
f78a5fda | 1448 | struct sk_buff *skb; |
1da177e4 LT |
1449 | long timeo; |
1450 | struct scm_cookie tmp_scm; | |
25888e30 | 1451 | int max_level; |
eb6a2481 | 1452 | int data_len = 0; |
1da177e4 LT |
1453 | |
1454 | if (NULL == siocb->scm) | |
1455 | siocb->scm = &tmp_scm; | |
5f23b734 | 1456 | wait_for_unix_gc(); |
e0e3cea4 | 1457 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1458 | if (err < 0) |
1459 | return err; | |
1460 | ||
1461 | err = -EOPNOTSUPP; | |
1462 | if (msg->msg_flags&MSG_OOB) | |
1463 | goto out; | |
1464 | ||
1465 | if (msg->msg_namelen) { | |
1466 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1467 | if (err < 0) | |
1468 | goto out; | |
1469 | namelen = err; | |
1470 | } else { | |
1471 | sunaddr = NULL; | |
1472 | err = -ENOTCONN; | |
1473 | other = unix_peer_get(sk); | |
1474 | if (!other) | |
1475 | goto out; | |
1476 | } | |
1477 | ||
f64f9e71 JP |
1478 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
1479 | && (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1480 | goto out; |
1481 | ||
1482 | err = -EMSGSIZE; | |
1483 | if (len > sk->sk_sndbuf - 32) | |
1484 | goto out; | |
1485 | ||
eb6a2481 ED |
1486 | if (len > SKB_MAX_ALLOC) |
1487 | data_len = min_t(size_t, | |
1488 | len - SKB_MAX_ALLOC, | |
1489 | MAX_SKB_FRAGS * PAGE_SIZE); | |
1490 | ||
1491 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
28d64271 ED |
1492 | msg->msg_flags & MSG_DONTWAIT, &err, |
1493 | PAGE_ALLOC_COSTLY_ORDER); | |
e27dfcea | 1494 | if (skb == NULL) |
1da177e4 LT |
1495 | goto out; |
1496 | ||
f78a5fda | 1497 | err = unix_scm_to_skb(siocb->scm, skb, true); |
25888e30 | 1498 | if (err < 0) |
7361c36c | 1499 | goto out_free; |
25888e30 | 1500 | max_level = err + 1; |
dc49c1f9 | 1501 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1502 | |
eb6a2481 ED |
1503 | skb_put(skb, len - data_len); |
1504 | skb->data_len = data_len; | |
1505 | skb->len = len; | |
1506 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); | |
1da177e4 LT |
1507 | if (err) |
1508 | goto out_free; | |
1509 | ||
1510 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1511 | ||
1512 | restart: | |
1513 | if (!other) { | |
1514 | err = -ECONNRESET; | |
1515 | if (sunaddr == NULL) | |
1516 | goto out_free; | |
1517 | ||
097e66c5 | 1518 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1da177e4 | 1519 | hash, &err); |
e27dfcea | 1520 | if (other == NULL) |
1da177e4 LT |
1521 | goto out_free; |
1522 | } | |
1523 | ||
d6ae3bae AC |
1524 | if (sk_filter(other, skb) < 0) { |
1525 | /* Toss the packet but do not return any error to the sender */ | |
1526 | err = len; | |
1527 | goto out_free; | |
1528 | } | |
1529 | ||
1c92b4e5 | 1530 | unix_state_lock(other); |
1da177e4 LT |
1531 | err = -EPERM; |
1532 | if (!unix_may_send(sk, other)) | |
1533 | goto out_unlock; | |
1534 | ||
1535 | if (sock_flag(other, SOCK_DEAD)) { | |
1536 | /* | |
1537 | * Check with 1003.1g - what should | |
1538 | * datagram error | |
1539 | */ | |
1c92b4e5 | 1540 | unix_state_unlock(other); |
1da177e4 LT |
1541 | sock_put(other); |
1542 | ||
1543 | err = 0; | |
1c92b4e5 | 1544 | unix_state_lock(sk); |
1da177e4 | 1545 | if (unix_peer(sk) == other) { |
e27dfcea | 1546 | unix_peer(sk) = NULL; |
1c92b4e5 | 1547 | unix_state_unlock(sk); |
1da177e4 LT |
1548 | |
1549 | unix_dgram_disconnected(sk, other); | |
1550 | sock_put(other); | |
1551 | err = -ECONNREFUSED; | |
1552 | } else { | |
1c92b4e5 | 1553 | unix_state_unlock(sk); |
1da177e4 LT |
1554 | } |
1555 | ||
1556 | other = NULL; | |
1557 | if (err) | |
1558 | goto out_free; | |
1559 | goto restart; | |
1560 | } | |
1561 | ||
1562 | err = -EPIPE; | |
1563 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1564 | goto out_unlock; | |
1565 | ||
1566 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1567 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1568 | if (err) | |
1569 | goto out_unlock; | |
1570 | } | |
1571 | ||
3c73419c | 1572 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1da177e4 LT |
1573 | if (!timeo) { |
1574 | err = -EAGAIN; | |
1575 | goto out_unlock; | |
1576 | } | |
1577 | ||
1578 | timeo = unix_wait_for_peer(other, timeo); | |
1579 | ||
1580 | err = sock_intr_errno(timeo); | |
1581 | if (signal_pending(current)) | |
1582 | goto out_free; | |
1583 | ||
1584 | goto restart; | |
1585 | } | |
1586 | ||
3f66116e AC |
1587 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
1588 | __net_timestamp(skb); | |
16e57262 | 1589 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1590 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1591 | if (max_level > unix_sk(other)->recursion_level) |
1592 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1593 | unix_state_unlock(other); |
1da177e4 LT |
1594 | other->sk_data_ready(other, len); |
1595 | sock_put(other); | |
f78a5fda | 1596 | scm_destroy(siocb->scm); |
1da177e4 LT |
1597 | return len; |
1598 | ||
1599 | out_unlock: | |
1c92b4e5 | 1600 | unix_state_unlock(other); |
1da177e4 LT |
1601 | out_free: |
1602 | kfree_skb(skb); | |
1603 | out: | |
1604 | if (other) | |
1605 | sock_put(other); | |
f78a5fda | 1606 | scm_destroy(siocb->scm); |
1da177e4 LT |
1607 | return err; |
1608 | } | |
1609 | ||
e370a723 ED |
1610 | /* We use paged skbs for stream sockets, and limit occupancy to 32768 |
1611 | * bytes, and a minimun of a full page. | |
1612 | */ | |
1613 | #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) | |
ac7bfa62 | 1614 | |
1da177e4 LT |
1615 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1616 | struct msghdr *msg, size_t len) | |
1617 | { | |
1618 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1619 | struct sock *sk = sock->sk; | |
1620 | struct sock *other = NULL; | |
6eba6a37 | 1621 | int err, size; |
f78a5fda | 1622 | struct sk_buff *skb; |
e27dfcea | 1623 | int sent = 0; |
1da177e4 | 1624 | struct scm_cookie tmp_scm; |
8ba69ba6 | 1625 | bool fds_sent = false; |
25888e30 | 1626 | int max_level; |
e370a723 | 1627 | int data_len; |
1da177e4 LT |
1628 | |
1629 | if (NULL == siocb->scm) | |
1630 | siocb->scm = &tmp_scm; | |
5f23b734 | 1631 | wait_for_unix_gc(); |
e0e3cea4 | 1632 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1633 | if (err < 0) |
1634 | return err; | |
1635 | ||
1636 | err = -EOPNOTSUPP; | |
1637 | if (msg->msg_flags&MSG_OOB) | |
1638 | goto out_err; | |
1639 | ||
1640 | if (msg->msg_namelen) { | |
1641 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1642 | goto out_err; | |
1643 | } else { | |
1da177e4 | 1644 | err = -ENOTCONN; |
830a1e5c | 1645 | other = unix_peer(sk); |
1da177e4 LT |
1646 | if (!other) |
1647 | goto out_err; | |
1648 | } | |
1649 | ||
1650 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1651 | goto pipe_err; | |
1652 | ||
6eba6a37 | 1653 | while (sent < len) { |
e370a723 | 1654 | size = len - sent; |
1da177e4 LT |
1655 | |
1656 | /* Keep two messages in the pipe so it schedules better */ | |
e370a723 | 1657 | size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); |
1da177e4 | 1658 | |
e370a723 ED |
1659 | /* allow fallback to order-0 allocations */ |
1660 | size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); | |
ac7bfa62 | 1661 | |
e370a723 | 1662 | data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); |
1da177e4 | 1663 | |
e370a723 | 1664 | skb = sock_alloc_send_pskb(sk, size - data_len, data_len, |
28d64271 ED |
1665 | msg->msg_flags & MSG_DONTWAIT, &err, |
1666 | get_order(UNIX_SKB_FRAGS_SZ)); | |
e370a723 | 1667 | if (!skb) |
1da177e4 LT |
1668 | goto out_err; |
1669 | ||
f78a5fda DM |
1670 | /* Only send the fds in the first buffer */ |
1671 | err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); | |
25888e30 | 1672 | if (err < 0) { |
7361c36c | 1673 | kfree_skb(skb); |
f78a5fda | 1674 | goto out_err; |
6209344f | 1675 | } |
25888e30 | 1676 | max_level = err + 1; |
7361c36c | 1677 | fds_sent = true; |
1da177e4 | 1678 | |
e370a723 ED |
1679 | skb_put(skb, size - data_len); |
1680 | skb->data_len = data_len; | |
1681 | skb->len = size; | |
f3dfd208 ED |
1682 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, |
1683 | sent, size); | |
6eba6a37 | 1684 | if (err) { |
1da177e4 | 1685 | kfree_skb(skb); |
f78a5fda | 1686 | goto out_err; |
1da177e4 LT |
1687 | } |
1688 | ||
1c92b4e5 | 1689 | unix_state_lock(other); |
1da177e4 LT |
1690 | |
1691 | if (sock_flag(other, SOCK_DEAD) || | |
1692 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1693 | goto pipe_err_free; | |
1694 | ||
16e57262 | 1695 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1696 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1697 | if (max_level > unix_sk(other)->recursion_level) |
1698 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1699 | unix_state_unlock(other); |
1da177e4 | 1700 | other->sk_data_ready(other, size); |
e27dfcea | 1701 | sent += size; |
1da177e4 | 1702 | } |
1da177e4 | 1703 | |
f78a5fda | 1704 | scm_destroy(siocb->scm); |
1da177e4 LT |
1705 | siocb->scm = NULL; |
1706 | ||
1707 | return sent; | |
1708 | ||
1709 | pipe_err_free: | |
1c92b4e5 | 1710 | unix_state_unlock(other); |
1da177e4 LT |
1711 | kfree_skb(skb); |
1712 | pipe_err: | |
6eba6a37 ED |
1713 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1714 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
1715 | err = -EPIPE; |
1716 | out_err: | |
f78a5fda | 1717 | scm_destroy(siocb->scm); |
1da177e4 LT |
1718 | siocb->scm = NULL; |
1719 | return sent ? : err; | |
1720 | } | |
1721 | ||
1722 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1723 | struct msghdr *msg, size_t len) | |
1724 | { | |
1725 | int err; | |
1726 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1727 | |
1da177e4 LT |
1728 | err = sock_error(sk); |
1729 | if (err) | |
1730 | return err; | |
1731 | ||
1732 | if (sk->sk_state != TCP_ESTABLISHED) | |
1733 | return -ENOTCONN; | |
1734 | ||
1735 | if (msg->msg_namelen) | |
1736 | msg->msg_namelen = 0; | |
1737 | ||
1738 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1739 | } | |
ac7bfa62 | 1740 | |
a05d2ad1 EB |
1741 | static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
1742 | struct msghdr *msg, size_t size, | |
1743 | int flags) | |
1744 | { | |
1745 | struct sock *sk = sock->sk; | |
1746 | ||
1747 | if (sk->sk_state != TCP_ESTABLISHED) | |
1748 | return -ENOTCONN; | |
1749 | ||
1750 | return unix_dgram_recvmsg(iocb, sock, msg, size, flags); | |
1751 | } | |
1752 | ||
1da177e4 LT |
1753 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1754 | { | |
1755 | struct unix_sock *u = unix_sk(sk); | |
1756 | ||
1da177e4 LT |
1757 | if (u->addr) { |
1758 | msg->msg_namelen = u->addr->len; | |
1759 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1760 | } | |
1761 | } | |
1762 | ||
1763 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1764 | struct msghdr *msg, size_t size, | |
1765 | int flags) | |
1766 | { | |
1767 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1768 | struct scm_cookie tmp_scm; | |
1769 | struct sock *sk = sock->sk; | |
1770 | struct unix_sock *u = unix_sk(sk); | |
1771 | int noblock = flags & MSG_DONTWAIT; | |
1772 | struct sk_buff *skb; | |
1773 | int err; | |
f55bb7f9 | 1774 | int peeked, skip; |
1da177e4 LT |
1775 | |
1776 | err = -EOPNOTSUPP; | |
1777 | if (flags&MSG_OOB) | |
1778 | goto out; | |
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); |
2b15af6f | 1882 | timeo = freezable_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 | ||
e370a723 ED |
1892 | static unsigned int unix_skb_len(const struct sk_buff *skb) |
1893 | { | |
1894 | return skb->len - UNIXCB(skb).consumed; | |
1895 | } | |
1896 | ||
1da177e4 LT |
1897 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
1898 | struct msghdr *msg, size_t size, | |
1899 | int flags) | |
1900 | { | |
1901 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1902 | struct scm_cookie tmp_scm; | |
1903 | struct sock *sk = sock->sk; | |
1904 | struct unix_sock *u = unix_sk(sk); | |
e27dfcea | 1905 | struct sockaddr_un *sunaddr = msg->msg_name; |
1da177e4 LT |
1906 | int copied = 0; |
1907 | int check_creds = 0; | |
1908 | int target; | |
1909 | int err = 0; | |
1910 | long timeo; | |
fc0d7536 | 1911 | int skip; |
1da177e4 LT |
1912 | |
1913 | err = -EINVAL; | |
1914 | if (sk->sk_state != TCP_ESTABLISHED) | |
1915 | goto out; | |
1916 | ||
1917 | err = -EOPNOTSUPP; | |
1918 | if (flags&MSG_OOB) | |
1919 | goto out; | |
1920 | ||
1921 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1922 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1923 | ||
1da177e4 LT |
1924 | /* Lock the socket to prevent queue disordering |
1925 | * while sleeps in memcpy_tomsg | |
1926 | */ | |
1927 | ||
1928 | if (!siocb->scm) { | |
1929 | siocb->scm = &tmp_scm; | |
1930 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1931 | } | |
1932 | ||
b3ca9b02 RW |
1933 | err = mutex_lock_interruptible(&u->readlock); |
1934 | if (err) { | |
1935 | err = sock_intr_errno(timeo); | |
1936 | goto out; | |
1937 | } | |
1da177e4 | 1938 | |
6eba6a37 | 1939 | do { |
1da177e4 | 1940 | int chunk; |
79f632c7 | 1941 | struct sk_buff *skb, *last; |
1da177e4 | 1942 | |
3c0d2f37 | 1943 | unix_state_lock(sk); |
79f632c7 | 1944 | last = skb = skb_peek(&sk->sk_receive_queue); |
fc0d7536 | 1945 | again: |
6eba6a37 | 1946 | if (skb == NULL) { |
25888e30 | 1947 | unix_sk(sk)->recursion_level = 0; |
1da177e4 | 1948 | if (copied >= target) |
3c0d2f37 | 1949 | goto unlock; |
1da177e4 LT |
1950 | |
1951 | /* | |
1952 | * POSIX 1003.1g mandates this order. | |
1953 | */ | |
ac7bfa62 | 1954 | |
6eba6a37 ED |
1955 | err = sock_error(sk); |
1956 | if (err) | |
3c0d2f37 | 1957 | goto unlock; |
1da177e4 | 1958 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1959 | goto unlock; |
1960 | ||
1961 | unix_state_unlock(sk); | |
1da177e4 LT |
1962 | err = -EAGAIN; |
1963 | if (!timeo) | |
1964 | break; | |
57b47a53 | 1965 | mutex_unlock(&u->readlock); |
1da177e4 | 1966 | |
79f632c7 | 1967 | timeo = unix_stream_data_wait(sk, timeo, last); |
1da177e4 | 1968 | |
b3ca9b02 RW |
1969 | if (signal_pending(current) |
1970 | || mutex_lock_interruptible(&u->readlock)) { | |
1da177e4 LT |
1971 | err = sock_intr_errno(timeo); |
1972 | goto out; | |
1973 | } | |
b3ca9b02 | 1974 | |
1da177e4 | 1975 | continue; |
3c0d2f37 MS |
1976 | unlock: |
1977 | unix_state_unlock(sk); | |
1978 | break; | |
1da177e4 | 1979 | } |
fc0d7536 | 1980 | |
79f632c7 | 1981 | skip = sk_peek_offset(sk, flags); |
e370a723 ED |
1982 | while (skip >= unix_skb_len(skb)) { |
1983 | skip -= unix_skb_len(skb); | |
79f632c7 | 1984 | last = skb; |
fc0d7536 | 1985 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
79f632c7 BP |
1986 | if (!skb) |
1987 | goto again; | |
fc0d7536 PE |
1988 | } |
1989 | ||
3c0d2f37 | 1990 | unix_state_unlock(sk); |
1da177e4 LT |
1991 | |
1992 | if (check_creds) { | |
1993 | /* Never glue messages from different writers */ | |
7361c36c | 1994 | if ((UNIXCB(skb).pid != siocb->scm->pid) || |
6b0ee8c0 EB |
1995 | !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) || |
1996 | !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid)) | |
1da177e4 | 1997 | break; |
0e82e7f6 | 1998 | } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { |
1da177e4 | 1999 | /* Copy credentials */ |
6b0ee8c0 | 2000 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
1da177e4 LT |
2001 | check_creds = 1; |
2002 | } | |
2003 | ||
2004 | /* Copy address just once */ | |
6eba6a37 | 2005 | if (sunaddr) { |
1da177e4 LT |
2006 | unix_copy_addr(msg, skb->sk); |
2007 | sunaddr = NULL; | |
2008 | } | |
2009 | ||
e370a723 ED |
2010 | chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size); |
2011 | if (skb_copy_datagram_iovec(skb, UNIXCB(skb).consumed + skip, | |
2012 | msg->msg_iov, chunk)) { | |
1da177e4 LT |
2013 | if (copied == 0) |
2014 | copied = -EFAULT; | |
2015 | break; | |
2016 | } | |
2017 | copied += chunk; | |
2018 | size -= chunk; | |
2019 | ||
2020 | /* Mark read part of skb as used */ | |
6eba6a37 | 2021 | if (!(flags & MSG_PEEK)) { |
e370a723 | 2022 | UNIXCB(skb).consumed += chunk; |
1da177e4 | 2023 | |
fc0d7536 PE |
2024 | sk_peek_offset_bwd(sk, chunk); |
2025 | ||
1da177e4 LT |
2026 | if (UNIXCB(skb).fp) |
2027 | unix_detach_fds(siocb->scm, skb); | |
2028 | ||
e370a723 | 2029 | if (unix_skb_len(skb)) |
1da177e4 | 2030 | break; |
1da177e4 | 2031 | |
6f01fd6e | 2032 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2033 | consume_skb(skb); |
1da177e4 LT |
2034 | |
2035 | if (siocb->scm->fp) | |
2036 | break; | |
6eba6a37 | 2037 | } else { |
1da177e4 LT |
2038 | /* It is questionable, see note in unix_dgram_recvmsg. |
2039 | */ | |
2040 | if (UNIXCB(skb).fp) | |
2041 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
2042 | ||
fc0d7536 PE |
2043 | sk_peek_offset_fwd(sk, chunk); |
2044 | ||
1da177e4 LT |
2045 | break; |
2046 | } | |
2047 | } while (size); | |
2048 | ||
57b47a53 | 2049 | mutex_unlock(&u->readlock); |
1da177e4 LT |
2050 | scm_recv(sock, msg, siocb->scm, flags); |
2051 | out: | |
2052 | return copied ? : err; | |
2053 | } | |
2054 | ||
2055 | static int unix_shutdown(struct socket *sock, int mode) | |
2056 | { | |
2057 | struct sock *sk = sock->sk; | |
2058 | struct sock *other; | |
2059 | ||
fc61b928 XW |
2060 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
2061 | return -EINVAL; | |
2062 | /* This maps: | |
2063 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2064 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2065 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2066 | */ | |
2067 | ++mode; | |
7180a031 AC |
2068 | |
2069 | unix_state_lock(sk); | |
2070 | sk->sk_shutdown |= mode; | |
2071 | other = unix_peer(sk); | |
2072 | if (other) | |
2073 | sock_hold(other); | |
2074 | unix_state_unlock(sk); | |
2075 | sk->sk_state_change(sk); | |
2076 | ||
2077 | if (other && | |
2078 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2079 | ||
2080 | int peer_mode = 0; | |
2081 | ||
2082 | if (mode&RCV_SHUTDOWN) | |
2083 | peer_mode |= SEND_SHUTDOWN; | |
2084 | if (mode&SEND_SHUTDOWN) | |
2085 | peer_mode |= RCV_SHUTDOWN; | |
2086 | unix_state_lock(other); | |
2087 | other->sk_shutdown |= peer_mode; | |
2088 | unix_state_unlock(other); | |
2089 | other->sk_state_change(other); | |
2090 | if (peer_mode == SHUTDOWN_MASK) | |
2091 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2092 | else if (peer_mode & RCV_SHUTDOWN) | |
2093 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
1da177e4 | 2094 | } |
7180a031 AC |
2095 | if (other) |
2096 | sock_put(other); | |
2097 | ||
1da177e4 LT |
2098 | return 0; |
2099 | } | |
2100 | ||
885ee74d PE |
2101 | long unix_inq_len(struct sock *sk) |
2102 | { | |
2103 | struct sk_buff *skb; | |
2104 | long amount = 0; | |
2105 | ||
2106 | if (sk->sk_state == TCP_LISTEN) | |
2107 | return -EINVAL; | |
2108 | ||
2109 | spin_lock(&sk->sk_receive_queue.lock); | |
2110 | if (sk->sk_type == SOCK_STREAM || | |
2111 | sk->sk_type == SOCK_SEQPACKET) { | |
2112 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
e370a723 | 2113 | amount += unix_skb_len(skb); |
885ee74d PE |
2114 | } else { |
2115 | skb = skb_peek(&sk->sk_receive_queue); | |
2116 | if (skb) | |
2117 | amount = skb->len; | |
2118 | } | |
2119 | spin_unlock(&sk->sk_receive_queue.lock); | |
2120 | ||
2121 | return amount; | |
2122 | } | |
2123 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2124 | ||
2125 | long unix_outq_len(struct sock *sk) | |
2126 | { | |
2127 | return sk_wmem_alloc_get(sk); | |
2128 | } | |
2129 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2130 | ||
1da177e4 LT |
2131 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
2132 | { | |
2133 | struct sock *sk = sock->sk; | |
e27dfcea | 2134 | long amount = 0; |
1da177e4 LT |
2135 | int err; |
2136 | ||
6eba6a37 ED |
2137 | switch (cmd) { |
2138 | case SIOCOUTQ: | |
885ee74d | 2139 | amount = unix_outq_len(sk); |
6eba6a37 ED |
2140 | err = put_user(amount, (int __user *)arg); |
2141 | break; | |
2142 | case SIOCINQ: | |
885ee74d PE |
2143 | amount = unix_inq_len(sk); |
2144 | if (amount < 0) | |
2145 | err = amount; | |
2146 | else | |
1da177e4 | 2147 | err = put_user(amount, (int __user *)arg); |
885ee74d | 2148 | break; |
6eba6a37 ED |
2149 | default: |
2150 | err = -ENOIOCTLCMD; | |
2151 | break; | |
1da177e4 LT |
2152 | } |
2153 | return err; | |
2154 | } | |
2155 | ||
6eba6a37 | 2156 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
2157 | { |
2158 | struct sock *sk = sock->sk; | |
2159 | unsigned int mask; | |
2160 | ||
aa395145 | 2161 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
2162 | mask = 0; |
2163 | ||
2164 | /* exceptional events? */ | |
2165 | if (sk->sk_err) | |
2166 | mask |= POLLERR; | |
2167 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2168 | mask |= POLLHUP; | |
f348d70a | 2169 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 2170 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
2171 | |
2172 | /* readable? */ | |
db40980f | 2173 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
2174 | mask |= POLLIN | POLLRDNORM; |
2175 | ||
2176 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
2177 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2178 | sk->sk_state == TCP_CLOSE) | |
1da177e4 LT |
2179 | mask |= POLLHUP; |
2180 | ||
2181 | /* | |
2182 | * we set writable also when the other side has shut down the | |
2183 | * connection. This prevents stuck sockets. | |
2184 | */ | |
2185 | if (unix_writable(sk)) | |
2186 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2187 | ||
2188 | return mask; | |
2189 | } | |
2190 | ||
ec0d215f RW |
2191 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2192 | poll_table *wait) | |
3c73419c | 2193 | { |
ec0d215f RW |
2194 | struct sock *sk = sock->sk, *other; |
2195 | unsigned int mask, writable; | |
3c73419c | 2196 | |
aa395145 | 2197 | sock_poll_wait(file, sk_sleep(sk), wait); |
3c73419c RW |
2198 | mask = 0; |
2199 | ||
2200 | /* exceptional events? */ | |
2201 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
7d4c04fc | 2202 | mask |= POLLERR | |
8facd5fb | 2203 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0); |
7d4c04fc | 2204 | |
3c73419c | 2205 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
5456f09a | 2206 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
3c73419c RW |
2207 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2208 | mask |= POLLHUP; | |
2209 | ||
2210 | /* readable? */ | |
5456f09a | 2211 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
3c73419c RW |
2212 | mask |= POLLIN | POLLRDNORM; |
2213 | ||
2214 | /* Connection-based need to check for termination and startup */ | |
2215 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2216 | if (sk->sk_state == TCP_CLOSE) | |
2217 | mask |= POLLHUP; | |
2218 | /* connection hasn't started yet? */ | |
2219 | if (sk->sk_state == TCP_SYN_SENT) | |
2220 | return mask; | |
2221 | } | |
2222 | ||
973a34aa | 2223 | /* No write status requested, avoid expensive OUT tests. */ |
626cf236 | 2224 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
973a34aa ED |
2225 | return mask; |
2226 | ||
ec0d215f | 2227 | writable = unix_writable(sk); |
5456f09a ED |
2228 | other = unix_peer_get(sk); |
2229 | if (other) { | |
2230 | if (unix_peer(other) != sk) { | |
2231 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); | |
2232 | if (unix_recvq_full(other)) | |
2233 | writable = 0; | |
ec0d215f | 2234 | } |
5456f09a | 2235 | sock_put(other); |
ec0d215f RW |
2236 | } |
2237 | ||
2238 | if (writable) | |
3c73419c RW |
2239 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2240 | else | |
2241 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
2242 | ||
3c73419c RW |
2243 | return mask; |
2244 | } | |
1da177e4 LT |
2245 | |
2246 | #ifdef CONFIG_PROC_FS | |
a53eb3fe | 2247 | |
7123aaa3 ED |
2248 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
2249 | ||
2250 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
2251 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) | |
2252 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) | |
a53eb3fe | 2253 | |
7123aaa3 | 2254 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
1da177e4 | 2255 | { |
7123aaa3 ED |
2256 | unsigned long offset = get_offset(*pos); |
2257 | unsigned long bucket = get_bucket(*pos); | |
2258 | struct sock *sk; | |
2259 | unsigned long count = 0; | |
1da177e4 | 2260 | |
7123aaa3 ED |
2261 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { |
2262 | if (sock_net(sk) != seq_file_net(seq)) | |
097e66c5 | 2263 | continue; |
7123aaa3 ED |
2264 | if (++count == offset) |
2265 | break; | |
2266 | } | |
2267 | ||
2268 | return sk; | |
2269 | } | |
2270 | ||
2271 | static struct sock *unix_next_socket(struct seq_file *seq, | |
2272 | struct sock *sk, | |
2273 | loff_t *pos) | |
2274 | { | |
2275 | unsigned long bucket; | |
2276 | ||
2277 | while (sk > (struct sock *)SEQ_START_TOKEN) { | |
2278 | sk = sk_next(sk); | |
2279 | if (!sk) | |
2280 | goto next_bucket; | |
2281 | if (sock_net(sk) == seq_file_net(seq)) | |
2282 | return sk; | |
1da177e4 | 2283 | } |
7123aaa3 ED |
2284 | |
2285 | do { | |
2286 | sk = unix_from_bucket(seq, pos); | |
2287 | if (sk) | |
2288 | return sk; | |
2289 | ||
2290 | next_bucket: | |
2291 | bucket = get_bucket(*pos) + 1; | |
2292 | *pos = set_bucket_offset(bucket, 1); | |
2293 | } while (bucket < ARRAY_SIZE(unix_socket_table)); | |
2294 | ||
1da177e4 LT |
2295 | return NULL; |
2296 | } | |
2297 | ||
1da177e4 | 2298 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
9a429c49 | 2299 | __acquires(unix_table_lock) |
1da177e4 | 2300 | { |
fbe9cc4a | 2301 | spin_lock(&unix_table_lock); |
7123aaa3 ED |
2302 | |
2303 | if (!*pos) | |
2304 | return SEQ_START_TOKEN; | |
2305 | ||
2306 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) | |
2307 | return NULL; | |
2308 | ||
2309 | return unix_next_socket(seq, NULL, pos); | |
1da177e4 LT |
2310 | } |
2311 | ||
2312 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2313 | { | |
2314 | ++*pos; | |
7123aaa3 | 2315 | return unix_next_socket(seq, v, pos); |
1da177e4 LT |
2316 | } |
2317 | ||
2318 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2319 | __releases(unix_table_lock) |
1da177e4 | 2320 | { |
fbe9cc4a | 2321 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2322 | } |
2323 | ||
2324 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2325 | { | |
ac7bfa62 | 2326 | |
b9f3124f | 2327 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
2328 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2329 | "Inode Path\n"); | |
2330 | else { | |
2331 | struct sock *s = v; | |
2332 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2333 | unix_state_lock(s); |
1da177e4 | 2334 | |
71338aa7 | 2335 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 LT |
2336 | s, |
2337 | atomic_read(&s->sk_refcnt), | |
2338 | 0, | |
2339 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2340 | s->sk_type, | |
2341 | s->sk_socket ? | |
2342 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2343 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2344 | sock_i_ino(s)); | |
2345 | ||
2346 | if (u->addr) { | |
2347 | int i, len; | |
2348 | seq_putc(seq, ' '); | |
2349 | ||
2350 | i = 0; | |
2351 | len = u->addr->len - sizeof(short); | |
2352 | if (!UNIX_ABSTRACT(s)) | |
2353 | len--; | |
2354 | else { | |
2355 | seq_putc(seq, '@'); | |
2356 | i++; | |
2357 | } | |
2358 | for ( ; i < len; i++) | |
2359 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2360 | } | |
1c92b4e5 | 2361 | unix_state_unlock(s); |
1da177e4 LT |
2362 | seq_putc(seq, '\n'); |
2363 | } | |
2364 | ||
2365 | return 0; | |
2366 | } | |
2367 | ||
56b3d975 | 2368 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2369 | .start = unix_seq_start, |
2370 | .next = unix_seq_next, | |
2371 | .stop = unix_seq_stop, | |
2372 | .show = unix_seq_show, | |
2373 | }; | |
2374 | ||
1da177e4 LT |
2375 | static int unix_seq_open(struct inode *inode, struct file *file) |
2376 | { | |
e372c414 | 2377 | return seq_open_net(inode, file, &unix_seq_ops, |
8b51b064 | 2378 | sizeof(struct seq_net_private)); |
1da177e4 LT |
2379 | } |
2380 | ||
da7071d7 | 2381 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2382 | .owner = THIS_MODULE, |
2383 | .open = unix_seq_open, | |
2384 | .read = seq_read, | |
2385 | .llseek = seq_lseek, | |
e372c414 | 2386 | .release = seq_release_net, |
1da177e4 LT |
2387 | }; |
2388 | ||
2389 | #endif | |
2390 | ||
ec1b4cf7 | 2391 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
2392 | .family = PF_UNIX, |
2393 | .create = unix_create, | |
2394 | .owner = THIS_MODULE, | |
2395 | }; | |
2396 | ||
097e66c5 | 2397 | |
2c8c1e72 | 2398 | static int __net_init unix_net_init(struct net *net) |
097e66c5 DL |
2399 | { |
2400 | int error = -ENOMEM; | |
2401 | ||
a0a53c8b | 2402 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
2403 | if (unix_sysctl_register(net)) |
2404 | goto out; | |
d392e497 | 2405 | |
097e66c5 | 2406 | #ifdef CONFIG_PROC_FS |
d4beaa66 | 2407 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { |
1597fbc0 | 2408 | unix_sysctl_unregister(net); |
097e66c5 | 2409 | goto out; |
1597fbc0 | 2410 | } |
097e66c5 DL |
2411 | #endif |
2412 | error = 0; | |
2413 | out: | |
48dcc33e | 2414 | return error; |
097e66c5 DL |
2415 | } |
2416 | ||
2c8c1e72 | 2417 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 2418 | { |
1597fbc0 | 2419 | unix_sysctl_unregister(net); |
ece31ffd | 2420 | remove_proc_entry("unix", net->proc_net); |
097e66c5 DL |
2421 | } |
2422 | ||
2423 | static struct pernet_operations unix_net_ops = { | |
2424 | .init = unix_net_init, | |
2425 | .exit = unix_net_exit, | |
2426 | }; | |
2427 | ||
1da177e4 LT |
2428 | static int __init af_unix_init(void) |
2429 | { | |
2430 | int rc = -1; | |
1da177e4 | 2431 | |
b4fff5f8 | 2432 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 LT |
2433 | |
2434 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 YH |
2435 | if (rc != 0) { |
2436 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
0dc47877 | 2437 | __func__); |
1da177e4 LT |
2438 | goto out; |
2439 | } | |
2440 | ||
2441 | sock_register(&unix_family_ops); | |
097e66c5 | 2442 | register_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2443 | out: |
2444 | return rc; | |
2445 | } | |
2446 | ||
2447 | static void __exit af_unix_exit(void) | |
2448 | { | |
2449 | sock_unregister(PF_UNIX); | |
1da177e4 | 2450 | proto_unregister(&unix_proto); |
097e66c5 | 2451 | unregister_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2452 | } |
2453 | ||
3d366960 DW |
2454 | /* Earlier than device_initcall() so that other drivers invoking |
2455 | request_module() don't end up in a loop when modprobe tries | |
2456 | to use a UNIX socket. But later than subsys_initcall() because | |
2457 | we depend on stuff initialised there */ | |
2458 | fs_initcall(af_unix_init); | |
1da177e4 LT |
2459 | module_exit(af_unix_exit); |
2460 | ||
2461 | MODULE_LICENSE("GPL"); | |
2462 | MODULE_ALIAS_NETPROTO(PF_UNIX); |