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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 | ||
5cc208be | 83 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
84 | ||
1da177e4 | 85 | #include <linux/module.h> |
1da177e4 | 86 | #include <linux/kernel.h> |
1da177e4 LT |
87 | #include <linux/signal.h> |
88 | #include <linux/sched.h> | |
89 | #include <linux/errno.h> | |
90 | #include <linux/string.h> | |
91 | #include <linux/stat.h> | |
92 | #include <linux/dcache.h> | |
93 | #include <linux/namei.h> | |
94 | #include <linux/socket.h> | |
95 | #include <linux/un.h> | |
96 | #include <linux/fcntl.h> | |
97 | #include <linux/termios.h> | |
98 | #include <linux/sockios.h> | |
99 | #include <linux/net.h> | |
100 | #include <linux/in.h> | |
101 | #include <linux/fs.h> | |
102 | #include <linux/slab.h> | |
103 | #include <asm/uaccess.h> | |
104 | #include <linux/skbuff.h> | |
105 | #include <linux/netdevice.h> | |
457c4cbc | 106 | #include <net/net_namespace.h> |
1da177e4 | 107 | #include <net/sock.h> |
c752f073 | 108 | #include <net/tcp_states.h> |
1da177e4 LT |
109 | #include <net/af_unix.h> |
110 | #include <linux/proc_fs.h> | |
111 | #include <linux/seq_file.h> | |
112 | #include <net/scm.h> | |
113 | #include <linux/init.h> | |
114 | #include <linux/poll.h> | |
1da177e4 LT |
115 | #include <linux/rtnetlink.h> |
116 | #include <linux/mount.h> | |
117 | #include <net/checksum.h> | |
118 | #include <linux/security.h> | |
2b15af6f | 119 | #include <linux/freezer.h> |
1da177e4 | 120 | |
7123aaa3 | 121 | struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; |
fa7ff56f PE |
122 | EXPORT_SYMBOL_GPL(unix_socket_table); |
123 | DEFINE_SPINLOCK(unix_table_lock); | |
124 | EXPORT_SYMBOL_GPL(unix_table_lock); | |
518de9b3 | 125 | static atomic_long_t unix_nr_socks; |
1da177e4 | 126 | |
1da177e4 | 127 | |
7123aaa3 ED |
128 | static struct hlist_head *unix_sockets_unbound(void *addr) |
129 | { | |
130 | unsigned long hash = (unsigned long)addr; | |
131 | ||
132 | hash ^= hash >> 16; | |
133 | hash ^= hash >> 8; | |
134 | hash %= UNIX_HASH_SIZE; | |
135 | return &unix_socket_table[UNIX_HASH_SIZE + hash]; | |
136 | } | |
137 | ||
138 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE) | |
1da177e4 | 139 | |
877ce7c1 | 140 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 141 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 142 | { |
dc49c1f9 | 143 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
877ce7c1 CZ |
144 | } |
145 | ||
146 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
147 | { | |
dc49c1f9 | 148 | scm->secid = *UNIXSID(skb); |
877ce7c1 CZ |
149 | } |
150 | #else | |
dc49c1f9 | 151 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
152 | { } |
153 | ||
154 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
155 | { } | |
156 | #endif /* CONFIG_SECURITY_NETWORK */ | |
157 | ||
1da177e4 LT |
158 | /* |
159 | * SMP locking strategy: | |
fbe9cc4a | 160 | * hash table is protected with spinlock unix_table_lock |
663717f6 | 161 | * each socket state is protected by separate spin lock. |
1da177e4 LT |
162 | */ |
163 | ||
95c96174 | 164 | static inline unsigned int unix_hash_fold(__wsum n) |
1da177e4 | 165 | { |
95c96174 ED |
166 | unsigned int hash = (__force unsigned int)n; |
167 | ||
1da177e4 LT |
168 | hash ^= hash>>16; |
169 | hash ^= hash>>8; | |
170 | return hash&(UNIX_HASH_SIZE-1); | |
171 | } | |
172 | ||
173 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
174 | ||
175 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
176 | { | |
177 | return unix_peer(osk) == sk; | |
178 | } | |
179 | ||
180 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
181 | { | |
6eba6a37 | 182 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
183 | } |
184 | ||
3c73419c RW |
185 | static inline int unix_recvq_full(struct sock const *sk) |
186 | { | |
187 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
188 | } | |
189 | ||
fa7ff56f | 190 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
191 | { |
192 | struct sock *peer; | |
193 | ||
1c92b4e5 | 194 | unix_state_lock(s); |
1da177e4 LT |
195 | peer = unix_peer(s); |
196 | if (peer) | |
197 | sock_hold(peer); | |
1c92b4e5 | 198 | unix_state_unlock(s); |
1da177e4 LT |
199 | return peer; |
200 | } | |
fa7ff56f | 201 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 LT |
202 | |
203 | static inline void unix_release_addr(struct unix_address *addr) | |
204 | { | |
205 | if (atomic_dec_and_test(&addr->refcnt)) | |
206 | kfree(addr); | |
207 | } | |
208 | ||
209 | /* | |
210 | * Check unix socket name: | |
211 | * - should be not zero length. | |
212 | * - if started by not zero, should be NULL terminated (FS object) | |
213 | * - if started by zero, it is abstract name. | |
214 | */ | |
ac7bfa62 | 215 | |
95c96174 | 216 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
1da177e4 LT |
217 | { |
218 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
219 | return -EINVAL; | |
220 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
221 | return -EINVAL; | |
222 | if (sunaddr->sun_path[0]) { | |
223 | /* | |
224 | * This may look like an off by one error but it is a bit more | |
225 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
25985edc | 226 | * sun_path[108] doesn't as such exist. However in kernel space |
1da177e4 LT |
227 | * we are guaranteed that it is a valid memory location in our |
228 | * kernel address buffer. | |
229 | */ | |
e27dfcea | 230 | ((char *)sunaddr)[len] = 0; |
1da177e4 LT |
231 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
232 | return len; | |
233 | } | |
234 | ||
07f0757a | 235 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
1da177e4 LT |
236 | return len; |
237 | } | |
238 | ||
239 | static void __unix_remove_socket(struct sock *sk) | |
240 | { | |
241 | sk_del_node_init(sk); | |
242 | } | |
243 | ||
244 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
245 | { | |
547b792c | 246 | WARN_ON(!sk_unhashed(sk)); |
1da177e4 LT |
247 | sk_add_node(sk, list); |
248 | } | |
249 | ||
250 | static inline void unix_remove_socket(struct sock *sk) | |
251 | { | |
fbe9cc4a | 252 | spin_lock(&unix_table_lock); |
1da177e4 | 253 | __unix_remove_socket(sk); |
fbe9cc4a | 254 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
255 | } |
256 | ||
257 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
258 | { | |
fbe9cc4a | 259 | spin_lock(&unix_table_lock); |
1da177e4 | 260 | __unix_insert_socket(list, sk); |
fbe9cc4a | 261 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
262 | } |
263 | ||
097e66c5 DL |
264 | static struct sock *__unix_find_socket_byname(struct net *net, |
265 | struct sockaddr_un *sunname, | |
95c96174 | 266 | int len, int type, unsigned int hash) |
1da177e4 LT |
267 | { |
268 | struct sock *s; | |
1da177e4 | 269 | |
b67bfe0d | 270 | sk_for_each(s, &unix_socket_table[hash ^ type]) { |
1da177e4 LT |
271 | struct unix_sock *u = unix_sk(s); |
272 | ||
878628fb | 273 | if (!net_eq(sock_net(s), net)) |
097e66c5 DL |
274 | continue; |
275 | ||
1da177e4 LT |
276 | if (u->addr->len == len && |
277 | !memcmp(u->addr->name, sunname, len)) | |
278 | goto found; | |
279 | } | |
280 | s = NULL; | |
281 | found: | |
282 | return s; | |
283 | } | |
284 | ||
097e66c5 DL |
285 | static inline struct sock *unix_find_socket_byname(struct net *net, |
286 | struct sockaddr_un *sunname, | |
1da177e4 | 287 | int len, int type, |
95c96174 | 288 | unsigned int hash) |
1da177e4 LT |
289 | { |
290 | struct sock *s; | |
291 | ||
fbe9cc4a | 292 | spin_lock(&unix_table_lock); |
097e66c5 | 293 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
294 | if (s) |
295 | sock_hold(s); | |
fbe9cc4a | 296 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
297 | return s; |
298 | } | |
299 | ||
6616f788 | 300 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 LT |
301 | { |
302 | struct sock *s; | |
1da177e4 | 303 | |
fbe9cc4a | 304 | spin_lock(&unix_table_lock); |
b67bfe0d | 305 | sk_for_each(s, |
1da177e4 | 306 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
40ffe67d | 307 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 308 | |
6eba6a37 | 309 | if (dentry && dentry->d_inode == i) { |
1da177e4 LT |
310 | sock_hold(s); |
311 | goto found; | |
312 | } | |
313 | } | |
314 | s = NULL; | |
315 | found: | |
fbe9cc4a | 316 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
317 | return s; |
318 | } | |
319 | ||
320 | static inline int unix_writable(struct sock *sk) | |
321 | { | |
322 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
323 | } | |
324 | ||
325 | static void unix_write_space(struct sock *sk) | |
326 | { | |
43815482 ED |
327 | struct socket_wq *wq; |
328 | ||
329 | rcu_read_lock(); | |
1da177e4 | 330 | if (unix_writable(sk)) { |
43815482 ED |
331 | wq = rcu_dereference(sk->sk_wq); |
332 | if (wq_has_sleeper(wq)) | |
67426b75 ED |
333 | wake_up_interruptible_sync_poll(&wq->wait, |
334 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
8d8ad9d7 | 335 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 336 | } |
43815482 | 337 | rcu_read_unlock(); |
1da177e4 LT |
338 | } |
339 | ||
340 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
341 | * queue of packets arrived from previous peer. First, it allows to do | |
342 | * flow control based only on wmem_alloc; second, sk connected to peer | |
343 | * may receive messages only from that peer. */ | |
344 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
345 | { | |
b03efcfb | 346 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
347 | skb_queue_purge(&sk->sk_receive_queue); |
348 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
349 | ||
350 | /* If one link of bidirectional dgram pipe is disconnected, | |
351 | * we signal error. Messages are lost. Do not make this, | |
352 | * when peer was not connected to us. | |
353 | */ | |
354 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
355 | other->sk_err = ECONNRESET; | |
356 | other->sk_error_report(other); | |
357 | } | |
358 | } | |
359 | } | |
360 | ||
361 | static void unix_sock_destructor(struct sock *sk) | |
362 | { | |
363 | struct unix_sock *u = unix_sk(sk); | |
364 | ||
365 | skb_queue_purge(&sk->sk_receive_queue); | |
366 | ||
547b792c IJ |
367 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
368 | WARN_ON(!sk_unhashed(sk)); | |
369 | WARN_ON(sk->sk_socket); | |
1da177e4 | 370 | if (!sock_flag(sk, SOCK_DEAD)) { |
5cc208be | 371 | pr_info("Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
372 | return; |
373 | } | |
374 | ||
375 | if (u->addr) | |
376 | unix_release_addr(u->addr); | |
377 | ||
518de9b3 | 378 | atomic_long_dec(&unix_nr_socks); |
6f756a8c | 379 | local_bh_disable(); |
a8076d8d | 380 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
6f756a8c | 381 | local_bh_enable(); |
1da177e4 | 382 | #ifdef UNIX_REFCNT_DEBUG |
5cc208be | 383 | pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk, |
518de9b3 | 384 | atomic_long_read(&unix_nr_socks)); |
1da177e4 LT |
385 | #endif |
386 | } | |
387 | ||
ded34e0f | 388 | static void unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
389 | { |
390 | struct unix_sock *u = unix_sk(sk); | |
40ffe67d | 391 | struct path path; |
1da177e4 LT |
392 | struct sock *skpair; |
393 | struct sk_buff *skb; | |
394 | int state; | |
395 | ||
396 | unix_remove_socket(sk); | |
397 | ||
398 | /* Clear state */ | |
1c92b4e5 | 399 | unix_state_lock(sk); |
1da177e4 LT |
400 | sock_orphan(sk); |
401 | sk->sk_shutdown = SHUTDOWN_MASK; | |
40ffe67d AV |
402 | path = u->path; |
403 | u->path.dentry = NULL; | |
404 | u->path.mnt = NULL; | |
1da177e4 LT |
405 | state = sk->sk_state; |
406 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 407 | unix_state_unlock(sk); |
1da177e4 LT |
408 | |
409 | wake_up_interruptible_all(&u->peer_wait); | |
410 | ||
e27dfcea | 411 | skpair = unix_peer(sk); |
1da177e4 | 412 | |
e27dfcea | 413 | if (skpair != NULL) { |
1da177e4 | 414 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 415 | unix_state_lock(skpair); |
1da177e4 LT |
416 | /* No more writes */ |
417 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
418 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
419 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 420 | unix_state_unlock(skpair); |
1da177e4 | 421 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 422 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 LT |
423 | } |
424 | sock_put(skpair); /* It may now die */ | |
425 | unix_peer(sk) = NULL; | |
426 | } | |
427 | ||
428 | /* Try to flush out this socket. Throw out buffers at least */ | |
429 | ||
430 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 431 | if (state == TCP_LISTEN) |
1da177e4 LT |
432 | unix_release_sock(skb->sk, 1); |
433 | /* passed fds are erased in the kfree_skb hook */ | |
434 | kfree_skb(skb); | |
435 | } | |
436 | ||
40ffe67d AV |
437 | if (path.dentry) |
438 | path_put(&path); | |
1da177e4 LT |
439 | |
440 | sock_put(sk); | |
441 | ||
442 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
443 | ||
444 | /* | |
e04dae84 | 445 | * Fixme: BSD difference: In BSD all sockets connected to us get |
1da177e4 LT |
446 | * ECONNRESET and we die on the spot. In Linux we behave |
447 | * like files and pipes do and wait for the last | |
448 | * dereference. | |
449 | * | |
450 | * Can't we simply set sock->err? | |
451 | * | |
452 | * What the above comment does talk about? --ANK(980817) | |
453 | */ | |
454 | ||
9305cfa4 | 455 | if (unix_tot_inflight) |
ac7bfa62 | 456 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
457 | } |
458 | ||
109f6e39 EB |
459 | static void init_peercred(struct sock *sk) |
460 | { | |
461 | put_pid(sk->sk_peer_pid); | |
462 | if (sk->sk_peer_cred) | |
463 | put_cred(sk->sk_peer_cred); | |
464 | sk->sk_peer_pid = get_pid(task_tgid(current)); | |
465 | sk->sk_peer_cred = get_current_cred(); | |
466 | } | |
467 | ||
468 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
469 | { | |
470 | put_pid(sk->sk_peer_pid); | |
471 | if (sk->sk_peer_cred) | |
472 | put_cred(sk->sk_peer_cred); | |
473 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); | |
474 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
475 | } | |
476 | ||
1da177e4 LT |
477 | static int unix_listen(struct socket *sock, int backlog) |
478 | { | |
479 | int err; | |
480 | struct sock *sk = sock->sk; | |
481 | struct unix_sock *u = unix_sk(sk); | |
109f6e39 | 482 | struct pid *old_pid = NULL; |
1da177e4 LT |
483 | |
484 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
485 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
486 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
487 | err = -EINVAL; |
488 | if (!u->addr) | |
6eba6a37 | 489 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 490 | unix_state_lock(sk); |
1da177e4 LT |
491 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
492 | goto out_unlock; | |
493 | if (backlog > sk->sk_max_ack_backlog) | |
494 | wake_up_interruptible_all(&u->peer_wait); | |
495 | sk->sk_max_ack_backlog = backlog; | |
496 | sk->sk_state = TCP_LISTEN; | |
497 | /* set credentials so connect can copy them */ | |
109f6e39 | 498 | init_peercred(sk); |
1da177e4 LT |
499 | err = 0; |
500 | ||
501 | out_unlock: | |
1c92b4e5 | 502 | unix_state_unlock(sk); |
109f6e39 | 503 | put_pid(old_pid); |
1da177e4 LT |
504 | out: |
505 | return err; | |
506 | } | |
507 | ||
508 | static int unix_release(struct socket *); | |
509 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
510 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
511 | int addr_len, int flags); | |
512 | static int unix_socketpair(struct socket *, struct socket *); | |
513 | static int unix_accept(struct socket *, struct socket *, int); | |
514 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
515 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
ec0d215f RW |
516 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
517 | poll_table *); | |
1da177e4 LT |
518 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
519 | static int unix_shutdown(struct socket *, int); | |
520 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
521 | struct msghdr *, size_t); | |
522 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
523 | struct msghdr *, size_t, int); | |
524 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
525 | struct msghdr *, size_t); | |
526 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
527 | struct msghdr *, size_t, int); | |
528 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
529 | int, int); | |
530 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
531 | struct msghdr *, size_t); | |
a05d2ad1 EB |
532 | static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
533 | struct msghdr *, size_t, int); | |
1da177e4 | 534 | |
12663bfc | 535 | static int unix_set_peek_off(struct sock *sk, int val) |
f55bb7f9 PE |
536 | { |
537 | struct unix_sock *u = unix_sk(sk); | |
538 | ||
12663bfc SL |
539 | if (mutex_lock_interruptible(&u->readlock)) |
540 | return -EINTR; | |
541 | ||
f55bb7f9 PE |
542 | sk->sk_peek_off = val; |
543 | mutex_unlock(&u->readlock); | |
12663bfc SL |
544 | |
545 | return 0; | |
f55bb7f9 PE |
546 | } |
547 | ||
548 | ||
90ddc4f0 | 549 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
550 | .family = PF_UNIX, |
551 | .owner = THIS_MODULE, | |
552 | .release = unix_release, | |
553 | .bind = unix_bind, | |
554 | .connect = unix_stream_connect, | |
555 | .socketpair = unix_socketpair, | |
556 | .accept = unix_accept, | |
557 | .getname = unix_getname, | |
558 | .poll = unix_poll, | |
559 | .ioctl = unix_ioctl, | |
560 | .listen = unix_listen, | |
561 | .shutdown = unix_shutdown, | |
562 | .setsockopt = sock_no_setsockopt, | |
563 | .getsockopt = sock_no_getsockopt, | |
564 | .sendmsg = unix_stream_sendmsg, | |
565 | .recvmsg = unix_stream_recvmsg, | |
566 | .mmap = sock_no_mmap, | |
567 | .sendpage = sock_no_sendpage, | |
fc0d7536 | 568 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
569 | }; |
570 | ||
90ddc4f0 | 571 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
572 | .family = PF_UNIX, |
573 | .owner = THIS_MODULE, | |
574 | .release = unix_release, | |
575 | .bind = unix_bind, | |
576 | .connect = unix_dgram_connect, | |
577 | .socketpair = unix_socketpair, | |
578 | .accept = sock_no_accept, | |
579 | .getname = unix_getname, | |
ec0d215f | 580 | .poll = unix_dgram_poll, |
1da177e4 LT |
581 | .ioctl = unix_ioctl, |
582 | .listen = sock_no_listen, | |
583 | .shutdown = unix_shutdown, | |
584 | .setsockopt = sock_no_setsockopt, | |
585 | .getsockopt = sock_no_getsockopt, | |
586 | .sendmsg = unix_dgram_sendmsg, | |
587 | .recvmsg = unix_dgram_recvmsg, | |
588 | .mmap = sock_no_mmap, | |
589 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 590 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
591 | }; |
592 | ||
90ddc4f0 | 593 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
594 | .family = PF_UNIX, |
595 | .owner = THIS_MODULE, | |
596 | .release = unix_release, | |
597 | .bind = unix_bind, | |
598 | .connect = unix_stream_connect, | |
599 | .socketpair = unix_socketpair, | |
600 | .accept = unix_accept, | |
601 | .getname = unix_getname, | |
ec0d215f | 602 | .poll = unix_dgram_poll, |
1da177e4 LT |
603 | .ioctl = unix_ioctl, |
604 | .listen = unix_listen, | |
605 | .shutdown = unix_shutdown, | |
606 | .setsockopt = sock_no_setsockopt, | |
607 | .getsockopt = sock_no_getsockopt, | |
608 | .sendmsg = unix_seqpacket_sendmsg, | |
a05d2ad1 | 609 | .recvmsg = unix_seqpacket_recvmsg, |
1da177e4 LT |
610 | .mmap = sock_no_mmap, |
611 | .sendpage = sock_no_sendpage, | |
f55bb7f9 | 612 | .set_peek_off = unix_set_peek_off, |
1da177e4 LT |
613 | }; |
614 | ||
615 | static struct proto unix_proto = { | |
248969ae ED |
616 | .name = "UNIX", |
617 | .owner = THIS_MODULE, | |
248969ae | 618 | .obj_size = sizeof(struct unix_sock), |
1da177e4 LT |
619 | }; |
620 | ||
a09785a2 IM |
621 | /* |
622 | * AF_UNIX sockets do not interact with hardware, hence they | |
623 | * dont trigger interrupts - so it's safe for them to have | |
624 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
625 | * this special lock-class by reinitializing the spinlock key: | |
626 | */ | |
627 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
628 | ||
6eba6a37 | 629 | static struct sock *unix_create1(struct net *net, struct socket *sock) |
1da177e4 LT |
630 | { |
631 | struct sock *sk = NULL; | |
632 | struct unix_sock *u; | |
633 | ||
518de9b3 ED |
634 | atomic_long_inc(&unix_nr_socks); |
635 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) | |
1da177e4 LT |
636 | goto out; |
637 | ||
6257ff21 | 638 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
1da177e4 LT |
639 | if (!sk) |
640 | goto out; | |
641 | ||
6eba6a37 | 642 | sock_init_data(sock, sk); |
a09785a2 IM |
643 | lockdep_set_class(&sk->sk_receive_queue.lock, |
644 | &af_unix_sk_receive_queue_lock_key); | |
1da177e4 LT |
645 | |
646 | sk->sk_write_space = unix_write_space; | |
a0a53c8b | 647 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
1da177e4 LT |
648 | sk->sk_destruct = unix_sock_destructor; |
649 | u = unix_sk(sk); | |
40ffe67d AV |
650 | u->path.dentry = NULL; |
651 | u->path.mnt = NULL; | |
fd19f329 | 652 | spin_lock_init(&u->lock); |
516e0cc5 | 653 | atomic_long_set(&u->inflight, 0); |
1fd05ba5 | 654 | INIT_LIST_HEAD(&u->link); |
57b47a53 | 655 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 | 656 | init_waitqueue_head(&u->peer_wait); |
7123aaa3 | 657 | unix_insert_socket(unix_sockets_unbound(sk), sk); |
1da177e4 | 658 | out: |
284b327b | 659 | if (sk == NULL) |
518de9b3 | 660 | atomic_long_dec(&unix_nr_socks); |
920de804 ED |
661 | else { |
662 | local_bh_disable(); | |
a8076d8d | 663 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
920de804 ED |
664 | local_bh_enable(); |
665 | } | |
1da177e4 LT |
666 | return sk; |
667 | } | |
668 | ||
3f378b68 EP |
669 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
670 | int kern) | |
1da177e4 LT |
671 | { |
672 | if (protocol && protocol != PF_UNIX) | |
673 | return -EPROTONOSUPPORT; | |
674 | ||
675 | sock->state = SS_UNCONNECTED; | |
676 | ||
677 | switch (sock->type) { | |
678 | case SOCK_STREAM: | |
679 | sock->ops = &unix_stream_ops; | |
680 | break; | |
681 | /* | |
682 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
683 | * nothing uses it. | |
684 | */ | |
685 | case SOCK_RAW: | |
e27dfcea | 686 | sock->type = SOCK_DGRAM; |
1da177e4 LT |
687 | case SOCK_DGRAM: |
688 | sock->ops = &unix_dgram_ops; | |
689 | break; | |
690 | case SOCK_SEQPACKET: | |
691 | sock->ops = &unix_seqpacket_ops; | |
692 | break; | |
693 | default: | |
694 | return -ESOCKTNOSUPPORT; | |
695 | } | |
696 | ||
1b8d7ae4 | 697 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
1da177e4 LT |
698 | } |
699 | ||
700 | static int unix_release(struct socket *sock) | |
701 | { | |
702 | struct sock *sk = sock->sk; | |
703 | ||
704 | if (!sk) | |
705 | return 0; | |
706 | ||
ded34e0f | 707 | unix_release_sock(sk, 0); |
1da177e4 LT |
708 | sock->sk = NULL; |
709 | ||
ded34e0f | 710 | return 0; |
1da177e4 LT |
711 | } |
712 | ||
713 | static int unix_autobind(struct socket *sock) | |
714 | { | |
715 | struct sock *sk = sock->sk; | |
3b1e0a65 | 716 | struct net *net = sock_net(sk); |
1da177e4 LT |
717 | struct unix_sock *u = unix_sk(sk); |
718 | static u32 ordernum = 1; | |
6eba6a37 | 719 | struct unix_address *addr; |
1da177e4 | 720 | int err; |
8df73ff9 | 721 | unsigned int retries = 0; |
1da177e4 | 722 | |
37ab4fa7 SL |
723 | err = mutex_lock_interruptible(&u->readlock); |
724 | if (err) | |
725 | return err; | |
1da177e4 LT |
726 | |
727 | err = 0; | |
728 | if (u->addr) | |
729 | goto out; | |
730 | ||
731 | err = -ENOMEM; | |
0da974f4 | 732 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
733 | if (!addr) |
734 | goto out; | |
735 | ||
1da177e4 LT |
736 | addr->name->sun_family = AF_UNIX; |
737 | atomic_set(&addr->refcnt, 1); | |
738 | ||
739 | retry: | |
740 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
07f0757a | 741 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
1da177e4 | 742 | |
fbe9cc4a | 743 | spin_lock(&unix_table_lock); |
1da177e4 LT |
744 | ordernum = (ordernum+1)&0xFFFFF; |
745 | ||
097e66c5 | 746 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
1da177e4 | 747 | addr->hash)) { |
fbe9cc4a | 748 | spin_unlock(&unix_table_lock); |
8df73ff9 TH |
749 | /* |
750 | * __unix_find_socket_byname() may take long time if many names | |
751 | * are already in use. | |
752 | */ | |
753 | cond_resched(); | |
754 | /* Give up if all names seems to be in use. */ | |
755 | if (retries++ == 0xFFFFF) { | |
756 | err = -ENOSPC; | |
757 | kfree(addr); | |
758 | goto out; | |
759 | } | |
1da177e4 LT |
760 | goto retry; |
761 | } | |
762 | addr->hash ^= sk->sk_type; | |
763 | ||
764 | __unix_remove_socket(sk); | |
765 | u->addr = addr; | |
766 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 767 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
768 | err = 0; |
769 | ||
57b47a53 | 770 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
771 | return err; |
772 | } | |
773 | ||
097e66c5 DL |
774 | static struct sock *unix_find_other(struct net *net, |
775 | struct sockaddr_un *sunname, int len, | |
95c96174 | 776 | int type, unsigned int hash, int *error) |
1da177e4 LT |
777 | { |
778 | struct sock *u; | |
421748ec | 779 | struct path path; |
1da177e4 | 780 | int err = 0; |
ac7bfa62 | 781 | |
1da177e4 | 782 | if (sunname->sun_path[0]) { |
421748ec AV |
783 | struct inode *inode; |
784 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
1da177e4 LT |
785 | if (err) |
786 | goto fail; | |
421748ec AV |
787 | inode = path.dentry->d_inode; |
788 | err = inode_permission(inode, MAY_WRITE); | |
1da177e4 LT |
789 | if (err) |
790 | goto put_fail; | |
791 | ||
792 | err = -ECONNREFUSED; | |
421748ec | 793 | if (!S_ISSOCK(inode->i_mode)) |
1da177e4 | 794 | goto put_fail; |
6616f788 | 795 | u = unix_find_socket_byinode(inode); |
1da177e4 LT |
796 | if (!u) |
797 | goto put_fail; | |
798 | ||
799 | if (u->sk_type == type) | |
68ac1234 | 800 | touch_atime(&path); |
1da177e4 | 801 | |
421748ec | 802 | path_put(&path); |
1da177e4 | 803 | |
e27dfcea | 804 | err = -EPROTOTYPE; |
1da177e4 LT |
805 | if (u->sk_type != type) { |
806 | sock_put(u); | |
807 | goto fail; | |
808 | } | |
809 | } else { | |
810 | err = -ECONNREFUSED; | |
e27dfcea | 811 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
812 | if (u) { |
813 | struct dentry *dentry; | |
40ffe67d | 814 | dentry = unix_sk(u)->path.dentry; |
1da177e4 | 815 | if (dentry) |
68ac1234 | 816 | touch_atime(&unix_sk(u)->path); |
1da177e4 LT |
817 | } else |
818 | goto fail; | |
819 | } | |
820 | return u; | |
821 | ||
822 | put_fail: | |
421748ec | 823 | path_put(&path); |
1da177e4 | 824 | fail: |
e27dfcea | 825 | *error = err; |
1da177e4 LT |
826 | return NULL; |
827 | } | |
828 | ||
faf02010 AV |
829 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) |
830 | { | |
831 | struct dentry *dentry; | |
832 | struct path path; | |
833 | int err = 0; | |
834 | /* | |
835 | * Get the parent directory, calculate the hash for last | |
836 | * component. | |
837 | */ | |
838 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); | |
839 | err = PTR_ERR(dentry); | |
840 | if (IS_ERR(dentry)) | |
841 | return err; | |
842 | ||
843 | /* | |
844 | * All right, let's create it. | |
845 | */ | |
846 | err = security_path_mknod(&path, dentry, mode, 0); | |
847 | if (!err) { | |
848 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); | |
849 | if (!err) { | |
850 | res->mnt = mntget(path.mnt); | |
851 | res->dentry = dget(dentry); | |
852 | } | |
853 | } | |
854 | done_path_create(&path, dentry); | |
855 | return err; | |
856 | } | |
1da177e4 LT |
857 | |
858 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
859 | { | |
860 | struct sock *sk = sock->sk; | |
3b1e0a65 | 861 | struct net *net = sock_net(sk); |
1da177e4 | 862 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 863 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
dae6ad8f | 864 | char *sun_path = sunaddr->sun_path; |
1da177e4 | 865 | int err; |
95c96174 | 866 | unsigned int hash; |
1da177e4 LT |
867 | struct unix_address *addr; |
868 | struct hlist_head *list; | |
869 | ||
870 | err = -EINVAL; | |
871 | if (sunaddr->sun_family != AF_UNIX) | |
872 | goto out; | |
873 | ||
e27dfcea | 874 | if (addr_len == sizeof(short)) { |
1da177e4 LT |
875 | err = unix_autobind(sock); |
876 | goto out; | |
877 | } | |
878 | ||
879 | err = unix_mkname(sunaddr, addr_len, &hash); | |
880 | if (err < 0) | |
881 | goto out; | |
882 | addr_len = err; | |
883 | ||
37ab4fa7 SL |
884 | err = mutex_lock_interruptible(&u->readlock); |
885 | if (err) | |
886 | goto out; | |
1da177e4 LT |
887 | |
888 | err = -EINVAL; | |
889 | if (u->addr) | |
890 | goto out_up; | |
891 | ||
892 | err = -ENOMEM; | |
893 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
894 | if (!addr) | |
895 | goto out_up; | |
896 | ||
897 | memcpy(addr->name, sunaddr, addr_len); | |
898 | addr->len = addr_len; | |
899 | addr->hash = hash ^ sk->sk_type; | |
900 | atomic_set(&addr->refcnt, 1); | |
901 | ||
dae6ad8f | 902 | if (sun_path[0]) { |
faf02010 AV |
903 | struct path path; |
904 | umode_t mode = S_IFSOCK | | |
ce3b0f8d | 905 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
faf02010 AV |
906 | err = unix_mknod(sun_path, mode, &path); |
907 | if (err) { | |
908 | if (err == -EEXIST) | |
909 | err = -EADDRINUSE; | |
910 | unix_release_addr(addr); | |
911 | goto out_up; | |
912 | } | |
1da177e4 | 913 | addr->hash = UNIX_HASH_SIZE; |
faf02010 AV |
914 | hash = path.dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1); |
915 | spin_lock(&unix_table_lock); | |
916 | u->path = path; | |
917 | list = &unix_socket_table[hash]; | |
918 | } else { | |
919 | spin_lock(&unix_table_lock); | |
1da177e4 | 920 | err = -EADDRINUSE; |
097e66c5 | 921 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
1da177e4 LT |
922 | sk->sk_type, hash)) { |
923 | unix_release_addr(addr); | |
924 | goto out_unlock; | |
925 | } | |
926 | ||
927 | list = &unix_socket_table[addr->hash]; | |
1da177e4 LT |
928 | } |
929 | ||
930 | err = 0; | |
931 | __unix_remove_socket(sk); | |
932 | u->addr = addr; | |
933 | __unix_insert_socket(list, sk); | |
934 | ||
935 | out_unlock: | |
fbe9cc4a | 936 | spin_unlock(&unix_table_lock); |
1da177e4 | 937 | out_up: |
57b47a53 | 938 | mutex_unlock(&u->readlock); |
1da177e4 LT |
939 | out: |
940 | return err; | |
1da177e4 LT |
941 | } |
942 | ||
278a3de5 DM |
943 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
944 | { | |
945 | if (unlikely(sk1 == sk2) || !sk2) { | |
946 | unix_state_lock(sk1); | |
947 | return; | |
948 | } | |
949 | if (sk1 < sk2) { | |
950 | unix_state_lock(sk1); | |
951 | unix_state_lock_nested(sk2); | |
952 | } else { | |
953 | unix_state_lock(sk2); | |
954 | unix_state_lock_nested(sk1); | |
955 | } | |
956 | } | |
957 | ||
958 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
959 | { | |
960 | if (unlikely(sk1 == sk2) || !sk2) { | |
961 | unix_state_unlock(sk1); | |
962 | return; | |
963 | } | |
964 | unix_state_unlock(sk1); | |
965 | unix_state_unlock(sk2); | |
966 | } | |
967 | ||
1da177e4 LT |
968 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
969 | int alen, int flags) | |
970 | { | |
971 | struct sock *sk = sock->sk; | |
3b1e0a65 | 972 | struct net *net = sock_net(sk); |
e27dfcea | 973 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
1da177e4 | 974 | struct sock *other; |
95c96174 | 975 | unsigned int hash; |
1da177e4 LT |
976 | int err; |
977 | ||
978 | if (addr->sa_family != AF_UNSPEC) { | |
979 | err = unix_mkname(sunaddr, alen, &hash); | |
980 | if (err < 0) | |
981 | goto out; | |
982 | alen = err; | |
983 | ||
984 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
985 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
986 | goto out; | |
987 | ||
278a3de5 | 988 | restart: |
e27dfcea | 989 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
1da177e4 LT |
990 | if (!other) |
991 | goto out; | |
992 | ||
278a3de5 DM |
993 | unix_state_double_lock(sk, other); |
994 | ||
995 | /* Apparently VFS overslept socket death. Retry. */ | |
996 | if (sock_flag(other, SOCK_DEAD)) { | |
997 | unix_state_double_unlock(sk, other); | |
998 | sock_put(other); | |
999 | goto restart; | |
1000 | } | |
1da177e4 LT |
1001 | |
1002 | err = -EPERM; | |
1003 | if (!unix_may_send(sk, other)) | |
1004 | goto out_unlock; | |
1005 | ||
1006 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1007 | if (err) | |
1008 | goto out_unlock; | |
1009 | ||
1010 | } else { | |
1011 | /* | |
1012 | * 1003.1g breaking connected state with AF_UNSPEC | |
1013 | */ | |
1014 | other = NULL; | |
278a3de5 | 1015 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1016 | } |
1017 | ||
1018 | /* | |
1019 | * If it was connected, reconnect. | |
1020 | */ | |
1021 | if (unix_peer(sk)) { | |
1022 | struct sock *old_peer = unix_peer(sk); | |
e27dfcea | 1023 | unix_peer(sk) = other; |
278a3de5 | 1024 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1025 | |
1026 | if (other != old_peer) | |
1027 | unix_dgram_disconnected(sk, old_peer); | |
1028 | sock_put(old_peer); | |
1029 | } else { | |
e27dfcea | 1030 | unix_peer(sk) = other; |
278a3de5 | 1031 | unix_state_double_unlock(sk, other); |
1da177e4 | 1032 | } |
ac7bfa62 | 1033 | return 0; |
1da177e4 LT |
1034 | |
1035 | out_unlock: | |
278a3de5 | 1036 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1037 | sock_put(other); |
1038 | out: | |
1039 | return err; | |
1040 | } | |
1041 | ||
1042 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1043 | { | |
1044 | struct unix_sock *u = unix_sk(other); | |
1045 | int sched; | |
1046 | DEFINE_WAIT(wait); | |
1047 | ||
1048 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1049 | ||
1050 | sched = !sock_flag(other, SOCK_DEAD) && | |
1051 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
3c73419c | 1052 | unix_recvq_full(other); |
1da177e4 | 1053 | |
1c92b4e5 | 1054 | unix_state_unlock(other); |
1da177e4 LT |
1055 | |
1056 | if (sched) | |
1057 | timeo = schedule_timeout(timeo); | |
1058 | ||
1059 | finish_wait(&u->peer_wait, &wait); | |
1060 | return timeo; | |
1061 | } | |
1062 | ||
1063 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1064 | int addr_len, int flags) | |
1065 | { | |
e27dfcea | 1066 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1da177e4 | 1067 | struct sock *sk = sock->sk; |
3b1e0a65 | 1068 | struct net *net = sock_net(sk); |
1da177e4 LT |
1069 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1070 | struct sock *newsk = NULL; | |
1071 | struct sock *other = NULL; | |
1072 | struct sk_buff *skb = NULL; | |
95c96174 | 1073 | unsigned int hash; |
1da177e4 LT |
1074 | int st; |
1075 | int err; | |
1076 | long timeo; | |
1077 | ||
1078 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1079 | if (err < 0) | |
1080 | goto out; | |
1081 | addr_len = err; | |
1082 | ||
f64f9e71 JP |
1083 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
1084 | (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1085 | goto out; |
1086 | ||
1087 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1088 | ||
1089 | /* First of all allocate resources. | |
1090 | If we will make it after state is locked, | |
1091 | we will have to recheck all again in any case. | |
1092 | */ | |
1093 | ||
1094 | err = -ENOMEM; | |
1095 | ||
1096 | /* create new sock for complete connection */ | |
3b1e0a65 | 1097 | newsk = unix_create1(sock_net(sk), NULL); |
1da177e4 LT |
1098 | if (newsk == NULL) |
1099 | goto out; | |
1100 | ||
1101 | /* Allocate skb for sending to listening sock */ | |
1102 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1103 | if (skb == NULL) | |
1104 | goto out; | |
1105 | ||
1106 | restart: | |
1107 | /* Find listening sock. */ | |
097e66c5 | 1108 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1da177e4 LT |
1109 | if (!other) |
1110 | goto out; | |
1111 | ||
1112 | /* Latch state of peer */ | |
1c92b4e5 | 1113 | unix_state_lock(other); |
1da177e4 LT |
1114 | |
1115 | /* Apparently VFS overslept socket death. Retry. */ | |
1116 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1117 | unix_state_unlock(other); |
1da177e4 LT |
1118 | sock_put(other); |
1119 | goto restart; | |
1120 | } | |
1121 | ||
1122 | err = -ECONNREFUSED; | |
1123 | if (other->sk_state != TCP_LISTEN) | |
1124 | goto out_unlock; | |
77238f2b TS |
1125 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1126 | goto out_unlock; | |
1da177e4 | 1127 | |
3c73419c | 1128 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1129 | err = -EAGAIN; |
1130 | if (!timeo) | |
1131 | goto out_unlock; | |
1132 | ||
1133 | timeo = unix_wait_for_peer(other, timeo); | |
1134 | ||
1135 | err = sock_intr_errno(timeo); | |
1136 | if (signal_pending(current)) | |
1137 | goto out; | |
1138 | sock_put(other); | |
1139 | goto restart; | |
ac7bfa62 | 1140 | } |
1da177e4 LT |
1141 | |
1142 | /* Latch our state. | |
1143 | ||
e5537bfc | 1144 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1145 | drop lock on peer. It is dangerous because deadlock is |
1146 | possible. Connect to self case and simultaneous | |
1147 | attempt to connect are eliminated by checking socket | |
1148 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1149 | check this before attempt to grab lock. | |
1150 | ||
1151 | Well, and we have to recheck the state after socket locked. | |
1152 | */ | |
1153 | st = sk->sk_state; | |
1154 | ||
1155 | switch (st) { | |
1156 | case TCP_CLOSE: | |
1157 | /* This is ok... continue with connect */ | |
1158 | break; | |
1159 | case TCP_ESTABLISHED: | |
1160 | /* Socket is already connected */ | |
1161 | err = -EISCONN; | |
1162 | goto out_unlock; | |
1163 | default: | |
1164 | err = -EINVAL; | |
1165 | goto out_unlock; | |
1166 | } | |
1167 | ||
1c92b4e5 | 1168 | unix_state_lock_nested(sk); |
1da177e4 LT |
1169 | |
1170 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1171 | unix_state_unlock(sk); |
1172 | unix_state_unlock(other); | |
1da177e4 LT |
1173 | sock_put(other); |
1174 | goto restart; | |
1175 | } | |
1176 | ||
3610cda5 | 1177 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1178 | if (err) { |
1c92b4e5 | 1179 | unix_state_unlock(sk); |
1da177e4 LT |
1180 | goto out_unlock; |
1181 | } | |
1182 | ||
1183 | /* The way is open! Fastly set all the necessary fields... */ | |
1184 | ||
1185 | sock_hold(sk); | |
1186 | unix_peer(newsk) = sk; | |
1187 | newsk->sk_state = TCP_ESTABLISHED; | |
1188 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1189 | init_peercred(newsk); |
1da177e4 | 1190 | newu = unix_sk(newsk); |
eaefd110 | 1191 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1192 | otheru = unix_sk(other); |
1193 | ||
1194 | /* copy address information from listening to new sock*/ | |
1195 | if (otheru->addr) { | |
1196 | atomic_inc(&otheru->addr->refcnt); | |
1197 | newu->addr = otheru->addr; | |
1198 | } | |
40ffe67d AV |
1199 | if (otheru->path.dentry) { |
1200 | path_get(&otheru->path); | |
1201 | newu->path = otheru->path; | |
1da177e4 LT |
1202 | } |
1203 | ||
1204 | /* Set credentials */ | |
109f6e39 | 1205 | copy_peercred(sk, other); |
1da177e4 | 1206 | |
1da177e4 LT |
1207 | sock->state = SS_CONNECTED; |
1208 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1209 | sock_hold(newsk); |
1210 | ||
1211 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1212 | unix_peer(sk) = newsk; | |
1da177e4 | 1213 | |
1c92b4e5 | 1214 | unix_state_unlock(sk); |
1da177e4 LT |
1215 | |
1216 | /* take ten and and send info to listening sock */ | |
1217 | spin_lock(&other->sk_receive_queue.lock); | |
1218 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1219 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1220 | unix_state_unlock(other); |
1da177e4 LT |
1221 | other->sk_data_ready(other, 0); |
1222 | sock_put(other); | |
1223 | return 0; | |
1224 | ||
1225 | out_unlock: | |
1226 | if (other) | |
1c92b4e5 | 1227 | unix_state_unlock(other); |
1da177e4 LT |
1228 | |
1229 | out: | |
40d44446 | 1230 | kfree_skb(skb); |
1da177e4 LT |
1231 | if (newsk) |
1232 | unix_release_sock(newsk, 0); | |
1233 | if (other) | |
1234 | sock_put(other); | |
1235 | return err; | |
1236 | } | |
1237 | ||
1238 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1239 | { | |
e27dfcea | 1240 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1241 | |
1242 | /* Join our sockets back to back */ | |
1243 | sock_hold(ska); | |
1244 | sock_hold(skb); | |
e27dfcea JK |
1245 | unix_peer(ska) = skb; |
1246 | unix_peer(skb) = ska; | |
109f6e39 EB |
1247 | init_peercred(ska); |
1248 | init_peercred(skb); | |
1da177e4 LT |
1249 | |
1250 | if (ska->sk_type != SOCK_DGRAM) { | |
1251 | ska->sk_state = TCP_ESTABLISHED; | |
1252 | skb->sk_state = TCP_ESTABLISHED; | |
1253 | socka->state = SS_CONNECTED; | |
1254 | sockb->state = SS_CONNECTED; | |
1255 | } | |
1256 | return 0; | |
1257 | } | |
1258 | ||
90c6bd34 DB |
1259 | static void unix_sock_inherit_flags(const struct socket *old, |
1260 | struct socket *new) | |
1261 | { | |
1262 | if (test_bit(SOCK_PASSCRED, &old->flags)) | |
1263 | set_bit(SOCK_PASSCRED, &new->flags); | |
1264 | if (test_bit(SOCK_PASSSEC, &old->flags)) | |
1265 | set_bit(SOCK_PASSSEC, &new->flags); | |
1266 | } | |
1267 | ||
1da177e4 LT |
1268 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
1269 | { | |
1270 | struct sock *sk = sock->sk; | |
1271 | struct sock *tsk; | |
1272 | struct sk_buff *skb; | |
1273 | int err; | |
1274 | ||
1275 | err = -EOPNOTSUPP; | |
6eba6a37 | 1276 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1277 | goto out; |
1278 | ||
1279 | err = -EINVAL; | |
1280 | if (sk->sk_state != TCP_LISTEN) | |
1281 | goto out; | |
1282 | ||
1283 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1284 | * so that no locks are necessary. | |
1285 | */ | |
1286 | ||
1287 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1288 | if (!skb) { | |
1289 | /* This means receive shutdown. */ | |
1290 | if (err == 0) | |
1291 | err = -EINVAL; | |
1292 | goto out; | |
1293 | } | |
1294 | ||
1295 | tsk = skb->sk; | |
1296 | skb_free_datagram(sk, skb); | |
1297 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1298 | ||
1299 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1300 | unix_state_lock(tsk); |
1da177e4 | 1301 | newsock->state = SS_CONNECTED; |
90c6bd34 | 1302 | unix_sock_inherit_flags(sock, newsock); |
1da177e4 | 1303 | sock_graft(tsk, newsock); |
1c92b4e5 | 1304 | unix_state_unlock(tsk); |
1da177e4 LT |
1305 | return 0; |
1306 | ||
1307 | out: | |
1308 | return err; | |
1309 | } | |
1310 | ||
1311 | ||
1312 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1313 | { | |
1314 | struct sock *sk = sock->sk; | |
1315 | struct unix_sock *u; | |
13cfa97b | 1316 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1317 | int err = 0; |
1318 | ||
1319 | if (peer) { | |
1320 | sk = unix_peer_get(sk); | |
1321 | ||
1322 | err = -ENOTCONN; | |
1323 | if (!sk) | |
1324 | goto out; | |
1325 | err = 0; | |
1326 | } else { | |
1327 | sock_hold(sk); | |
1328 | } | |
1329 | ||
1330 | u = unix_sk(sk); | |
1c92b4e5 | 1331 | unix_state_lock(sk); |
1da177e4 LT |
1332 | if (!u->addr) { |
1333 | sunaddr->sun_family = AF_UNIX; | |
1334 | sunaddr->sun_path[0] = 0; | |
1335 | *uaddr_len = sizeof(short); | |
1336 | } else { | |
1337 | struct unix_address *addr = u->addr; | |
1338 | ||
1339 | *uaddr_len = addr->len; | |
1340 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1341 | } | |
1c92b4e5 | 1342 | unix_state_unlock(sk); |
1da177e4 LT |
1343 | sock_put(sk); |
1344 | out: | |
1345 | return err; | |
1346 | } | |
1347 | ||
1348 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1349 | { | |
1350 | int i; | |
1351 | ||
1352 | scm->fp = UNIXCB(skb).fp; | |
1da177e4 LT |
1353 | UNIXCB(skb).fp = NULL; |
1354 | ||
6eba6a37 | 1355 | for (i = scm->fp->count-1; i >= 0; i--) |
1da177e4 LT |
1356 | unix_notinflight(scm->fp->fp[i]); |
1357 | } | |
1358 | ||
7361c36c | 1359 | static void unix_destruct_scm(struct sk_buff *skb) |
1da177e4 LT |
1360 | { |
1361 | struct scm_cookie scm; | |
1362 | memset(&scm, 0, sizeof(scm)); | |
7361c36c | 1363 | scm.pid = UNIXCB(skb).pid; |
7361c36c EB |
1364 | if (UNIXCB(skb).fp) |
1365 | unix_detach_fds(&scm, skb); | |
1da177e4 LT |
1366 | |
1367 | /* Alas, it calls VFS */ | |
1368 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1369 | scm_destroy(&scm); | |
1370 | sock_wfree(skb); | |
1371 | } | |
1372 | ||
25888e30 ED |
1373 | #define MAX_RECURSION_LEVEL 4 |
1374 | ||
6209344f | 1375 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1da177e4 LT |
1376 | { |
1377 | int i; | |
25888e30 ED |
1378 | unsigned char max_level = 0; |
1379 | int unix_sock_count = 0; | |
1380 | ||
1381 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1382 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1383 | ||
1384 | if (sk) { | |
1385 | unix_sock_count++; | |
1386 | max_level = max(max_level, | |
1387 | unix_sk(sk)->recursion_level); | |
1388 | } | |
1389 | } | |
1390 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1391 | return -ETOOMANYREFS; | |
6209344f MS |
1392 | |
1393 | /* | |
1394 | * Need to duplicate file references for the sake of garbage | |
1395 | * collection. Otherwise a socket in the fps might become a | |
1396 | * candidate for GC while the skb is not yet queued. | |
1397 | */ | |
1398 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1399 | if (!UNIXCB(skb).fp) | |
1400 | return -ENOMEM; | |
1401 | ||
25888e30 ED |
1402 | if (unix_sock_count) { |
1403 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1404 | unix_inflight(scm->fp->fp[i]); | |
1405 | } | |
1406 | return max_level; | |
1da177e4 LT |
1407 | } |
1408 | ||
f78a5fda | 1409 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1410 | { |
1411 | int err = 0; | |
16e57262 | 1412 | |
f78a5fda | 1413 | UNIXCB(skb).pid = get_pid(scm->pid); |
6b0ee8c0 EB |
1414 | UNIXCB(skb).uid = scm->creds.uid; |
1415 | UNIXCB(skb).gid = scm->creds.gid; | |
7361c36c EB |
1416 | UNIXCB(skb).fp = NULL; |
1417 | if (scm->fp && send_fds) | |
1418 | err = unix_attach_fds(scm, skb); | |
1419 | ||
1420 | skb->destructor = unix_destruct_scm; | |
1421 | return err; | |
1422 | } | |
1423 | ||
16e57262 ED |
1424 | /* |
1425 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1426 | * We include credentials if source or destination socket | |
1427 | * asserted SOCK_PASSCRED. | |
1428 | */ | |
1429 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1430 | const struct sock *other) | |
1431 | { | |
6b0ee8c0 | 1432 | if (UNIXCB(skb).pid) |
16e57262 ED |
1433 | return; |
1434 | if (test_bit(SOCK_PASSCRED, &sock->flags) || | |
25da0e3e EB |
1435 | !other->sk_socket || |
1436 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { | |
16e57262 | 1437 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
6e0895c2 | 1438 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); |
16e57262 ED |
1439 | } |
1440 | } | |
1441 | ||
1da177e4 LT |
1442 | /* |
1443 | * Send AF_UNIX data. | |
1444 | */ | |
1445 | ||
1446 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1447 | struct msghdr *msg, size_t len) | |
1448 | { | |
1449 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1450 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1451 | struct net *net = sock_net(sk); |
1da177e4 | 1452 | struct unix_sock *u = unix_sk(sk); |
342dfc30 | 1453 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); |
1da177e4 LT |
1454 | struct sock *other = NULL; |
1455 | int namelen = 0; /* fake GCC */ | |
1456 | int err; | |
95c96174 | 1457 | unsigned int hash; |
f78a5fda | 1458 | struct sk_buff *skb; |
1da177e4 LT |
1459 | long timeo; |
1460 | struct scm_cookie tmp_scm; | |
25888e30 | 1461 | int max_level; |
eb6a2481 | 1462 | int data_len = 0; |
1da177e4 LT |
1463 | |
1464 | if (NULL == siocb->scm) | |
1465 | siocb->scm = &tmp_scm; | |
5f23b734 | 1466 | wait_for_unix_gc(); |
e0e3cea4 | 1467 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1468 | if (err < 0) |
1469 | return err; | |
1470 | ||
1471 | err = -EOPNOTSUPP; | |
1472 | if (msg->msg_flags&MSG_OOB) | |
1473 | goto out; | |
1474 | ||
1475 | if (msg->msg_namelen) { | |
1476 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1477 | if (err < 0) | |
1478 | goto out; | |
1479 | namelen = err; | |
1480 | } else { | |
1481 | sunaddr = NULL; | |
1482 | err = -ENOTCONN; | |
1483 | other = unix_peer_get(sk); | |
1484 | if (!other) | |
1485 | goto out; | |
1486 | } | |
1487 | ||
f64f9e71 JP |
1488 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
1489 | && (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1490 | goto out; |
1491 | ||
1492 | err = -EMSGSIZE; | |
1493 | if (len > sk->sk_sndbuf - 32) | |
1494 | goto out; | |
1495 | ||
eb6a2481 ED |
1496 | if (len > SKB_MAX_ALLOC) |
1497 | data_len = min_t(size_t, | |
1498 | len - SKB_MAX_ALLOC, | |
1499 | MAX_SKB_FRAGS * PAGE_SIZE); | |
1500 | ||
1501 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
28d64271 ED |
1502 | msg->msg_flags & MSG_DONTWAIT, &err, |
1503 | PAGE_ALLOC_COSTLY_ORDER); | |
e27dfcea | 1504 | if (skb == NULL) |
1da177e4 LT |
1505 | goto out; |
1506 | ||
f78a5fda | 1507 | err = unix_scm_to_skb(siocb->scm, skb, true); |
25888e30 | 1508 | if (err < 0) |
7361c36c | 1509 | goto out_free; |
25888e30 | 1510 | max_level = err + 1; |
dc49c1f9 | 1511 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1512 | |
eb6a2481 ED |
1513 | skb_put(skb, len - data_len); |
1514 | skb->data_len = data_len; | |
1515 | skb->len = len; | |
1516 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); | |
1da177e4 LT |
1517 | if (err) |
1518 | goto out_free; | |
1519 | ||
1520 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1521 | ||
1522 | restart: | |
1523 | if (!other) { | |
1524 | err = -ECONNRESET; | |
1525 | if (sunaddr == NULL) | |
1526 | goto out_free; | |
1527 | ||
097e66c5 | 1528 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1da177e4 | 1529 | hash, &err); |
e27dfcea | 1530 | if (other == NULL) |
1da177e4 LT |
1531 | goto out_free; |
1532 | } | |
1533 | ||
d6ae3bae AC |
1534 | if (sk_filter(other, skb) < 0) { |
1535 | /* Toss the packet but do not return any error to the sender */ | |
1536 | err = len; | |
1537 | goto out_free; | |
1538 | } | |
1539 | ||
1c92b4e5 | 1540 | unix_state_lock(other); |
1da177e4 LT |
1541 | err = -EPERM; |
1542 | if (!unix_may_send(sk, other)) | |
1543 | goto out_unlock; | |
1544 | ||
1545 | if (sock_flag(other, SOCK_DEAD)) { | |
1546 | /* | |
1547 | * Check with 1003.1g - what should | |
1548 | * datagram error | |
1549 | */ | |
1c92b4e5 | 1550 | unix_state_unlock(other); |
1da177e4 LT |
1551 | sock_put(other); |
1552 | ||
1553 | err = 0; | |
1c92b4e5 | 1554 | unix_state_lock(sk); |
1da177e4 | 1555 | if (unix_peer(sk) == other) { |
e27dfcea | 1556 | unix_peer(sk) = NULL; |
1c92b4e5 | 1557 | unix_state_unlock(sk); |
1da177e4 LT |
1558 | |
1559 | unix_dgram_disconnected(sk, other); | |
1560 | sock_put(other); | |
1561 | err = -ECONNREFUSED; | |
1562 | } else { | |
1c92b4e5 | 1563 | unix_state_unlock(sk); |
1da177e4 LT |
1564 | } |
1565 | ||
1566 | other = NULL; | |
1567 | if (err) | |
1568 | goto out_free; | |
1569 | goto restart; | |
1570 | } | |
1571 | ||
1572 | err = -EPIPE; | |
1573 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1574 | goto out_unlock; | |
1575 | ||
1576 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1577 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1578 | if (err) | |
1579 | goto out_unlock; | |
1580 | } | |
1581 | ||
3c73419c | 1582 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1da177e4 LT |
1583 | if (!timeo) { |
1584 | err = -EAGAIN; | |
1585 | goto out_unlock; | |
1586 | } | |
1587 | ||
1588 | timeo = unix_wait_for_peer(other, timeo); | |
1589 | ||
1590 | err = sock_intr_errno(timeo); | |
1591 | if (signal_pending(current)) | |
1592 | goto out_free; | |
1593 | ||
1594 | goto restart; | |
1595 | } | |
1596 | ||
3f66116e AC |
1597 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
1598 | __net_timestamp(skb); | |
16e57262 | 1599 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1600 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1601 | if (max_level > unix_sk(other)->recursion_level) |
1602 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1603 | unix_state_unlock(other); |
1da177e4 LT |
1604 | other->sk_data_ready(other, len); |
1605 | sock_put(other); | |
f78a5fda | 1606 | scm_destroy(siocb->scm); |
1da177e4 LT |
1607 | return len; |
1608 | ||
1609 | out_unlock: | |
1c92b4e5 | 1610 | unix_state_unlock(other); |
1da177e4 LT |
1611 | out_free: |
1612 | kfree_skb(skb); | |
1613 | out: | |
1614 | if (other) | |
1615 | sock_put(other); | |
f78a5fda | 1616 | scm_destroy(siocb->scm); |
1da177e4 LT |
1617 | return err; |
1618 | } | |
1619 | ||
e370a723 ED |
1620 | /* We use paged skbs for stream sockets, and limit occupancy to 32768 |
1621 | * bytes, and a minimun of a full page. | |
1622 | */ | |
1623 | #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) | |
ac7bfa62 | 1624 | |
1da177e4 LT |
1625 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1626 | struct msghdr *msg, size_t len) | |
1627 | { | |
1628 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1629 | struct sock *sk = sock->sk; | |
1630 | struct sock *other = NULL; | |
6eba6a37 | 1631 | int err, size; |
f78a5fda | 1632 | struct sk_buff *skb; |
e27dfcea | 1633 | int sent = 0; |
1da177e4 | 1634 | struct scm_cookie tmp_scm; |
8ba69ba6 | 1635 | bool fds_sent = false; |
25888e30 | 1636 | int max_level; |
e370a723 | 1637 | int data_len; |
1da177e4 LT |
1638 | |
1639 | if (NULL == siocb->scm) | |
1640 | siocb->scm = &tmp_scm; | |
5f23b734 | 1641 | wait_for_unix_gc(); |
e0e3cea4 | 1642 | err = scm_send(sock, msg, siocb->scm, false); |
1da177e4 LT |
1643 | if (err < 0) |
1644 | return err; | |
1645 | ||
1646 | err = -EOPNOTSUPP; | |
1647 | if (msg->msg_flags&MSG_OOB) | |
1648 | goto out_err; | |
1649 | ||
1650 | if (msg->msg_namelen) { | |
1651 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1652 | goto out_err; | |
1653 | } else { | |
1da177e4 | 1654 | err = -ENOTCONN; |
830a1e5c | 1655 | other = unix_peer(sk); |
1da177e4 LT |
1656 | if (!other) |
1657 | goto out_err; | |
1658 | } | |
1659 | ||
1660 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1661 | goto pipe_err; | |
1662 | ||
6eba6a37 | 1663 | while (sent < len) { |
e370a723 | 1664 | size = len - sent; |
1da177e4 LT |
1665 | |
1666 | /* Keep two messages in the pipe so it schedules better */ | |
e370a723 | 1667 | size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); |
1da177e4 | 1668 | |
e370a723 ED |
1669 | /* allow fallback to order-0 allocations */ |
1670 | size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); | |
ac7bfa62 | 1671 | |
e370a723 | 1672 | data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); |
1da177e4 | 1673 | |
e370a723 | 1674 | skb = sock_alloc_send_pskb(sk, size - data_len, data_len, |
28d64271 ED |
1675 | msg->msg_flags & MSG_DONTWAIT, &err, |
1676 | get_order(UNIX_SKB_FRAGS_SZ)); | |
e370a723 | 1677 | if (!skb) |
1da177e4 LT |
1678 | goto out_err; |
1679 | ||
f78a5fda DM |
1680 | /* Only send the fds in the first buffer */ |
1681 | err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); | |
25888e30 | 1682 | if (err < 0) { |
7361c36c | 1683 | kfree_skb(skb); |
f78a5fda | 1684 | goto out_err; |
6209344f | 1685 | } |
25888e30 | 1686 | max_level = err + 1; |
7361c36c | 1687 | fds_sent = true; |
1da177e4 | 1688 | |
e370a723 ED |
1689 | skb_put(skb, size - data_len); |
1690 | skb->data_len = data_len; | |
1691 | skb->len = size; | |
f3dfd208 ED |
1692 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, |
1693 | sent, size); | |
6eba6a37 | 1694 | if (err) { |
1da177e4 | 1695 | kfree_skb(skb); |
f78a5fda | 1696 | goto out_err; |
1da177e4 LT |
1697 | } |
1698 | ||
1c92b4e5 | 1699 | unix_state_lock(other); |
1da177e4 LT |
1700 | |
1701 | if (sock_flag(other, SOCK_DEAD) || | |
1702 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1703 | goto pipe_err_free; | |
1704 | ||
16e57262 | 1705 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1706 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1707 | if (max_level > unix_sk(other)->recursion_level) |
1708 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1709 | unix_state_unlock(other); |
1da177e4 | 1710 | other->sk_data_ready(other, size); |
e27dfcea | 1711 | sent += size; |
1da177e4 | 1712 | } |
1da177e4 | 1713 | |
f78a5fda | 1714 | scm_destroy(siocb->scm); |
1da177e4 LT |
1715 | siocb->scm = NULL; |
1716 | ||
1717 | return sent; | |
1718 | ||
1719 | pipe_err_free: | |
1c92b4e5 | 1720 | unix_state_unlock(other); |
1da177e4 LT |
1721 | kfree_skb(skb); |
1722 | pipe_err: | |
6eba6a37 ED |
1723 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1724 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
1725 | err = -EPIPE; |
1726 | out_err: | |
f78a5fda | 1727 | scm_destroy(siocb->scm); |
1da177e4 LT |
1728 | siocb->scm = NULL; |
1729 | return sent ? : err; | |
1730 | } | |
1731 | ||
1732 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1733 | struct msghdr *msg, size_t len) | |
1734 | { | |
1735 | int err; | |
1736 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1737 | |
1da177e4 LT |
1738 | err = sock_error(sk); |
1739 | if (err) | |
1740 | return err; | |
1741 | ||
1742 | if (sk->sk_state != TCP_ESTABLISHED) | |
1743 | return -ENOTCONN; | |
1744 | ||
1745 | if (msg->msg_namelen) | |
1746 | msg->msg_namelen = 0; | |
1747 | ||
1748 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1749 | } | |
ac7bfa62 | 1750 | |
a05d2ad1 EB |
1751 | static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
1752 | struct msghdr *msg, size_t size, | |
1753 | int flags) | |
1754 | { | |
1755 | struct sock *sk = sock->sk; | |
1756 | ||
1757 | if (sk->sk_state != TCP_ESTABLISHED) | |
1758 | return -ENOTCONN; | |
1759 | ||
1760 | return unix_dgram_recvmsg(iocb, sock, msg, size, flags); | |
1761 | } | |
1762 | ||
1da177e4 LT |
1763 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1764 | { | |
1765 | struct unix_sock *u = unix_sk(sk); | |
1766 | ||
1da177e4 LT |
1767 | if (u->addr) { |
1768 | msg->msg_namelen = u->addr->len; | |
1769 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1770 | } | |
1771 | } | |
1772 | ||
1773 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1774 | struct msghdr *msg, size_t size, | |
1775 | int flags) | |
1776 | { | |
1777 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1778 | struct scm_cookie tmp_scm; | |
1779 | struct sock *sk = sock->sk; | |
1780 | struct unix_sock *u = unix_sk(sk); | |
1781 | int noblock = flags & MSG_DONTWAIT; | |
1782 | struct sk_buff *skb; | |
1783 | int err; | |
f55bb7f9 | 1784 | int peeked, skip; |
1da177e4 LT |
1785 | |
1786 | err = -EOPNOTSUPP; | |
1787 | if (flags&MSG_OOB) | |
1788 | goto out; | |
1789 | ||
b3ca9b02 RW |
1790 | err = mutex_lock_interruptible(&u->readlock); |
1791 | if (err) { | |
1792 | err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); | |
1793 | goto out; | |
1794 | } | |
1da177e4 | 1795 | |
f55bb7f9 PE |
1796 | skip = sk_peek_offset(sk, flags); |
1797 | ||
1798 | skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); | |
0a112258 FZ |
1799 | if (!skb) { |
1800 | unix_state_lock(sk); | |
1801 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
1802 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
1803 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1804 | err = 0; | |
1805 | unix_state_unlock(sk); | |
1da177e4 | 1806 | goto out_unlock; |
0a112258 | 1807 | } |
1da177e4 | 1808 | |
67426b75 ED |
1809 | wake_up_interruptible_sync_poll(&u->peer_wait, |
1810 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
1da177e4 LT |
1811 | |
1812 | if (msg->msg_name) | |
1813 | unix_copy_addr(msg, skb->sk); | |
1814 | ||
f55bb7f9 PE |
1815 | if (size > skb->len - skip) |
1816 | size = skb->len - skip; | |
1817 | else if (size < skb->len - skip) | |
1da177e4 LT |
1818 | msg->msg_flags |= MSG_TRUNC; |
1819 | ||
f55bb7f9 | 1820 | err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size); |
1da177e4 LT |
1821 | if (err) |
1822 | goto out_free; | |
1823 | ||
3f66116e AC |
1824 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
1825 | __sock_recv_timestamp(msg, sk, skb); | |
1826 | ||
1da177e4 LT |
1827 | if (!siocb->scm) { |
1828 | siocb->scm = &tmp_scm; | |
1829 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1830 | } | |
6b0ee8c0 | 1831 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
877ce7c1 | 1832 | unix_set_secdata(siocb->scm, skb); |
1da177e4 | 1833 | |
6eba6a37 | 1834 | if (!(flags & MSG_PEEK)) { |
1da177e4 LT |
1835 | if (UNIXCB(skb).fp) |
1836 | unix_detach_fds(siocb->scm, skb); | |
f55bb7f9 PE |
1837 | |
1838 | sk_peek_offset_bwd(sk, skb->len); | |
6eba6a37 | 1839 | } else { |
1da177e4 LT |
1840 | /* It is questionable: on PEEK we could: |
1841 | - do not return fds - good, but too simple 8) | |
1842 | - return fds, and do not return them on read (old strategy, | |
1843 | apparently wrong) | |
1844 | - clone fds (I chose it for now, it is the most universal | |
1845 | solution) | |
ac7bfa62 YH |
1846 | |
1847 | POSIX 1003.1g does not actually define this clearly | |
1848 | at all. POSIX 1003.1g doesn't define a lot of things | |
1849 | clearly however! | |
1850 | ||
1da177e4 | 1851 | */ |
f55bb7f9 PE |
1852 | |
1853 | sk_peek_offset_fwd(sk, size); | |
1854 | ||
1da177e4 LT |
1855 | if (UNIXCB(skb).fp) |
1856 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1857 | } | |
9f6f9af7 | 1858 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
1da177e4 LT |
1859 | |
1860 | scm_recv(sock, msg, siocb->scm, flags); | |
1861 | ||
1862 | out_free: | |
6eba6a37 | 1863 | skb_free_datagram(sk, skb); |
1da177e4 | 1864 | out_unlock: |
57b47a53 | 1865 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1866 | out: |
1867 | return err; | |
1868 | } | |
1869 | ||
1870 | /* | |
79f632c7 | 1871 | * Sleep until more data has arrived. But check for races.. |
1da177e4 | 1872 | */ |
79f632c7 BP |
1873 | static long unix_stream_data_wait(struct sock *sk, long timeo, |
1874 | struct sk_buff *last) | |
1da177e4 LT |
1875 | { |
1876 | DEFINE_WAIT(wait); | |
1877 | ||
1c92b4e5 | 1878 | unix_state_lock(sk); |
1da177e4 LT |
1879 | |
1880 | for (;;) { | |
aa395145 | 1881 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
1da177e4 | 1882 | |
79f632c7 | 1883 | if (skb_peek_tail(&sk->sk_receive_queue) != last || |
1da177e4 LT |
1884 | sk->sk_err || |
1885 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1886 | signal_pending(current) || | |
1887 | !timeo) | |
1888 | break; | |
1889 | ||
1890 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1891 | unix_state_unlock(sk); |
2b15af6f | 1892 | timeo = freezable_schedule_timeout(timeo); |
1c92b4e5 | 1893 | unix_state_lock(sk); |
1da177e4 LT |
1894 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1895 | } | |
1896 | ||
aa395145 | 1897 | finish_wait(sk_sleep(sk), &wait); |
1c92b4e5 | 1898 | unix_state_unlock(sk); |
1da177e4 LT |
1899 | return timeo; |
1900 | } | |
1901 | ||
e370a723 ED |
1902 | static unsigned int unix_skb_len(const struct sk_buff *skb) |
1903 | { | |
1904 | return skb->len - UNIXCB(skb).consumed; | |
1905 | } | |
1906 | ||
1da177e4 LT |
1907 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
1908 | struct msghdr *msg, size_t size, | |
1909 | int flags) | |
1910 | { | |
1911 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1912 | struct scm_cookie tmp_scm; | |
1913 | struct sock *sk = sock->sk; | |
1914 | struct unix_sock *u = unix_sk(sk); | |
342dfc30 | 1915 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); |
1da177e4 LT |
1916 | int copied = 0; |
1917 | int check_creds = 0; | |
1918 | int target; | |
1919 | int err = 0; | |
1920 | long timeo; | |
fc0d7536 | 1921 | int skip; |
1da177e4 LT |
1922 | |
1923 | err = -EINVAL; | |
1924 | if (sk->sk_state != TCP_ESTABLISHED) | |
1925 | goto out; | |
1926 | ||
1927 | err = -EOPNOTSUPP; | |
1928 | if (flags&MSG_OOB) | |
1929 | goto out; | |
1930 | ||
1931 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1932 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1933 | ||
1da177e4 LT |
1934 | /* Lock the socket to prevent queue disordering |
1935 | * while sleeps in memcpy_tomsg | |
1936 | */ | |
1937 | ||
1938 | if (!siocb->scm) { | |
1939 | siocb->scm = &tmp_scm; | |
1940 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1941 | } | |
1942 | ||
b3ca9b02 RW |
1943 | err = mutex_lock_interruptible(&u->readlock); |
1944 | if (err) { | |
1945 | err = sock_intr_errno(timeo); | |
1946 | goto out; | |
1947 | } | |
1da177e4 | 1948 | |
6eba6a37 | 1949 | do { |
1da177e4 | 1950 | int chunk; |
79f632c7 | 1951 | struct sk_buff *skb, *last; |
1da177e4 | 1952 | |
3c0d2f37 | 1953 | unix_state_lock(sk); |
79f632c7 | 1954 | last = skb = skb_peek(&sk->sk_receive_queue); |
fc0d7536 | 1955 | again: |
6eba6a37 | 1956 | if (skb == NULL) { |
25888e30 | 1957 | unix_sk(sk)->recursion_level = 0; |
1da177e4 | 1958 | if (copied >= target) |
3c0d2f37 | 1959 | goto unlock; |
1da177e4 LT |
1960 | |
1961 | /* | |
1962 | * POSIX 1003.1g mandates this order. | |
1963 | */ | |
ac7bfa62 | 1964 | |
6eba6a37 ED |
1965 | err = sock_error(sk); |
1966 | if (err) | |
3c0d2f37 | 1967 | goto unlock; |
1da177e4 | 1968 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1969 | goto unlock; |
1970 | ||
1971 | unix_state_unlock(sk); | |
1da177e4 LT |
1972 | err = -EAGAIN; |
1973 | if (!timeo) | |
1974 | break; | |
57b47a53 | 1975 | mutex_unlock(&u->readlock); |
1da177e4 | 1976 | |
79f632c7 | 1977 | timeo = unix_stream_data_wait(sk, timeo, last); |
1da177e4 | 1978 | |
b3ca9b02 RW |
1979 | if (signal_pending(current) |
1980 | || mutex_lock_interruptible(&u->readlock)) { | |
1da177e4 LT |
1981 | err = sock_intr_errno(timeo); |
1982 | goto out; | |
1983 | } | |
b3ca9b02 | 1984 | |
1da177e4 | 1985 | continue; |
3c0d2f37 MS |
1986 | unlock: |
1987 | unix_state_unlock(sk); | |
1988 | break; | |
1da177e4 | 1989 | } |
fc0d7536 | 1990 | |
79f632c7 | 1991 | skip = sk_peek_offset(sk, flags); |
e370a723 ED |
1992 | while (skip >= unix_skb_len(skb)) { |
1993 | skip -= unix_skb_len(skb); | |
79f632c7 | 1994 | last = skb; |
fc0d7536 | 1995 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
79f632c7 BP |
1996 | if (!skb) |
1997 | goto again; | |
fc0d7536 PE |
1998 | } |
1999 | ||
3c0d2f37 | 2000 | unix_state_unlock(sk); |
1da177e4 LT |
2001 | |
2002 | if (check_creds) { | |
2003 | /* Never glue messages from different writers */ | |
7361c36c | 2004 | if ((UNIXCB(skb).pid != siocb->scm->pid) || |
6b0ee8c0 EB |
2005 | !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) || |
2006 | !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid)) | |
1da177e4 | 2007 | break; |
0e82e7f6 | 2008 | } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { |
1da177e4 | 2009 | /* Copy credentials */ |
6b0ee8c0 | 2010 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
1da177e4 LT |
2011 | check_creds = 1; |
2012 | } | |
2013 | ||
2014 | /* Copy address just once */ | |
6eba6a37 | 2015 | if (sunaddr) { |
1da177e4 LT |
2016 | unix_copy_addr(msg, skb->sk); |
2017 | sunaddr = NULL; | |
2018 | } | |
2019 | ||
e370a723 ED |
2020 | chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size); |
2021 | if (skb_copy_datagram_iovec(skb, UNIXCB(skb).consumed + skip, | |
2022 | msg->msg_iov, chunk)) { | |
1da177e4 LT |
2023 | if (copied == 0) |
2024 | copied = -EFAULT; | |
2025 | break; | |
2026 | } | |
2027 | copied += chunk; | |
2028 | size -= chunk; | |
2029 | ||
2030 | /* Mark read part of skb as used */ | |
6eba6a37 | 2031 | if (!(flags & MSG_PEEK)) { |
e370a723 | 2032 | UNIXCB(skb).consumed += chunk; |
1da177e4 | 2033 | |
fc0d7536 PE |
2034 | sk_peek_offset_bwd(sk, chunk); |
2035 | ||
1da177e4 LT |
2036 | if (UNIXCB(skb).fp) |
2037 | unix_detach_fds(siocb->scm, skb); | |
2038 | ||
e370a723 | 2039 | if (unix_skb_len(skb)) |
1da177e4 | 2040 | break; |
1da177e4 | 2041 | |
6f01fd6e | 2042 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2043 | consume_skb(skb); |
1da177e4 LT |
2044 | |
2045 | if (siocb->scm->fp) | |
2046 | break; | |
6eba6a37 | 2047 | } else { |
1da177e4 LT |
2048 | /* It is questionable, see note in unix_dgram_recvmsg. |
2049 | */ | |
2050 | if (UNIXCB(skb).fp) | |
2051 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
2052 | ||
fc0d7536 PE |
2053 | sk_peek_offset_fwd(sk, chunk); |
2054 | ||
1da177e4 LT |
2055 | break; |
2056 | } | |
2057 | } while (size); | |
2058 | ||
57b47a53 | 2059 | mutex_unlock(&u->readlock); |
1da177e4 LT |
2060 | scm_recv(sock, msg, siocb->scm, flags); |
2061 | out: | |
2062 | return copied ? : err; | |
2063 | } | |
2064 | ||
2065 | static int unix_shutdown(struct socket *sock, int mode) | |
2066 | { | |
2067 | struct sock *sk = sock->sk; | |
2068 | struct sock *other; | |
2069 | ||
fc61b928 XW |
2070 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
2071 | return -EINVAL; | |
2072 | /* This maps: | |
2073 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2074 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2075 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2076 | */ | |
2077 | ++mode; | |
7180a031 AC |
2078 | |
2079 | unix_state_lock(sk); | |
2080 | sk->sk_shutdown |= mode; | |
2081 | other = unix_peer(sk); | |
2082 | if (other) | |
2083 | sock_hold(other); | |
2084 | unix_state_unlock(sk); | |
2085 | sk->sk_state_change(sk); | |
2086 | ||
2087 | if (other && | |
2088 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2089 | ||
2090 | int peer_mode = 0; | |
2091 | ||
2092 | if (mode&RCV_SHUTDOWN) | |
2093 | peer_mode |= SEND_SHUTDOWN; | |
2094 | if (mode&SEND_SHUTDOWN) | |
2095 | peer_mode |= RCV_SHUTDOWN; | |
2096 | unix_state_lock(other); | |
2097 | other->sk_shutdown |= peer_mode; | |
2098 | unix_state_unlock(other); | |
2099 | other->sk_state_change(other); | |
2100 | if (peer_mode == SHUTDOWN_MASK) | |
2101 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2102 | else if (peer_mode & RCV_SHUTDOWN) | |
2103 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
1da177e4 | 2104 | } |
7180a031 AC |
2105 | if (other) |
2106 | sock_put(other); | |
2107 | ||
1da177e4 LT |
2108 | return 0; |
2109 | } | |
2110 | ||
885ee74d PE |
2111 | long unix_inq_len(struct sock *sk) |
2112 | { | |
2113 | struct sk_buff *skb; | |
2114 | long amount = 0; | |
2115 | ||
2116 | if (sk->sk_state == TCP_LISTEN) | |
2117 | return -EINVAL; | |
2118 | ||
2119 | spin_lock(&sk->sk_receive_queue.lock); | |
2120 | if (sk->sk_type == SOCK_STREAM || | |
2121 | sk->sk_type == SOCK_SEQPACKET) { | |
2122 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
e370a723 | 2123 | amount += unix_skb_len(skb); |
885ee74d PE |
2124 | } else { |
2125 | skb = skb_peek(&sk->sk_receive_queue); | |
2126 | if (skb) | |
2127 | amount = skb->len; | |
2128 | } | |
2129 | spin_unlock(&sk->sk_receive_queue.lock); | |
2130 | ||
2131 | return amount; | |
2132 | } | |
2133 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2134 | ||
2135 | long unix_outq_len(struct sock *sk) | |
2136 | { | |
2137 | return sk_wmem_alloc_get(sk); | |
2138 | } | |
2139 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2140 | ||
1da177e4 LT |
2141 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
2142 | { | |
2143 | struct sock *sk = sock->sk; | |
e27dfcea | 2144 | long amount = 0; |
1da177e4 LT |
2145 | int err; |
2146 | ||
6eba6a37 ED |
2147 | switch (cmd) { |
2148 | case SIOCOUTQ: | |
885ee74d | 2149 | amount = unix_outq_len(sk); |
6eba6a37 ED |
2150 | err = put_user(amount, (int __user *)arg); |
2151 | break; | |
2152 | case SIOCINQ: | |
885ee74d PE |
2153 | amount = unix_inq_len(sk); |
2154 | if (amount < 0) | |
2155 | err = amount; | |
2156 | else | |
1da177e4 | 2157 | err = put_user(amount, (int __user *)arg); |
885ee74d | 2158 | break; |
6eba6a37 ED |
2159 | default: |
2160 | err = -ENOIOCTLCMD; | |
2161 | break; | |
1da177e4 LT |
2162 | } |
2163 | return err; | |
2164 | } | |
2165 | ||
6eba6a37 | 2166 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
2167 | { |
2168 | struct sock *sk = sock->sk; | |
2169 | unsigned int mask; | |
2170 | ||
aa395145 | 2171 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
2172 | mask = 0; |
2173 | ||
2174 | /* exceptional events? */ | |
2175 | if (sk->sk_err) | |
2176 | mask |= POLLERR; | |
2177 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2178 | mask |= POLLHUP; | |
f348d70a | 2179 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 2180 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
2181 | |
2182 | /* readable? */ | |
db40980f | 2183 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
2184 | mask |= POLLIN | POLLRDNORM; |
2185 | ||
2186 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
2187 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2188 | sk->sk_state == TCP_CLOSE) | |
1da177e4 LT |
2189 | mask |= POLLHUP; |
2190 | ||
2191 | /* | |
2192 | * we set writable also when the other side has shut down the | |
2193 | * connection. This prevents stuck sockets. | |
2194 | */ | |
2195 | if (unix_writable(sk)) | |
2196 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2197 | ||
2198 | return mask; | |
2199 | } | |
2200 | ||
ec0d215f RW |
2201 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2202 | poll_table *wait) | |
3c73419c | 2203 | { |
ec0d215f RW |
2204 | struct sock *sk = sock->sk, *other; |
2205 | unsigned int mask, writable; | |
3c73419c | 2206 | |
aa395145 | 2207 | sock_poll_wait(file, sk_sleep(sk), wait); |
3c73419c RW |
2208 | mask = 0; |
2209 | ||
2210 | /* exceptional events? */ | |
2211 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
7d4c04fc | 2212 | mask |= POLLERR | |
8facd5fb | 2213 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0); |
7d4c04fc | 2214 | |
3c73419c | 2215 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
5456f09a | 2216 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
3c73419c RW |
2217 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2218 | mask |= POLLHUP; | |
2219 | ||
2220 | /* readable? */ | |
5456f09a | 2221 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
3c73419c RW |
2222 | mask |= POLLIN | POLLRDNORM; |
2223 | ||
2224 | /* Connection-based need to check for termination and startup */ | |
2225 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2226 | if (sk->sk_state == TCP_CLOSE) | |
2227 | mask |= POLLHUP; | |
2228 | /* connection hasn't started yet? */ | |
2229 | if (sk->sk_state == TCP_SYN_SENT) | |
2230 | return mask; | |
2231 | } | |
2232 | ||
973a34aa | 2233 | /* No write status requested, avoid expensive OUT tests. */ |
626cf236 | 2234 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
973a34aa ED |
2235 | return mask; |
2236 | ||
ec0d215f | 2237 | writable = unix_writable(sk); |
5456f09a ED |
2238 | other = unix_peer_get(sk); |
2239 | if (other) { | |
2240 | if (unix_peer(other) != sk) { | |
2241 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); | |
2242 | if (unix_recvq_full(other)) | |
2243 | writable = 0; | |
ec0d215f | 2244 | } |
5456f09a | 2245 | sock_put(other); |
ec0d215f RW |
2246 | } |
2247 | ||
2248 | if (writable) | |
3c73419c RW |
2249 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2250 | else | |
2251 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
2252 | ||
3c73419c RW |
2253 | return mask; |
2254 | } | |
1da177e4 LT |
2255 | |
2256 | #ifdef CONFIG_PROC_FS | |
a53eb3fe | 2257 | |
7123aaa3 ED |
2258 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
2259 | ||
2260 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
2261 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) | |
2262 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) | |
a53eb3fe | 2263 | |
7123aaa3 | 2264 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
1da177e4 | 2265 | { |
7123aaa3 ED |
2266 | unsigned long offset = get_offset(*pos); |
2267 | unsigned long bucket = get_bucket(*pos); | |
2268 | struct sock *sk; | |
2269 | unsigned long count = 0; | |
1da177e4 | 2270 | |
7123aaa3 ED |
2271 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { |
2272 | if (sock_net(sk) != seq_file_net(seq)) | |
097e66c5 | 2273 | continue; |
7123aaa3 ED |
2274 | if (++count == offset) |
2275 | break; | |
2276 | } | |
2277 | ||
2278 | return sk; | |
2279 | } | |
2280 | ||
2281 | static struct sock *unix_next_socket(struct seq_file *seq, | |
2282 | struct sock *sk, | |
2283 | loff_t *pos) | |
2284 | { | |
2285 | unsigned long bucket; | |
2286 | ||
2287 | while (sk > (struct sock *)SEQ_START_TOKEN) { | |
2288 | sk = sk_next(sk); | |
2289 | if (!sk) | |
2290 | goto next_bucket; | |
2291 | if (sock_net(sk) == seq_file_net(seq)) | |
2292 | return sk; | |
1da177e4 | 2293 | } |
7123aaa3 ED |
2294 | |
2295 | do { | |
2296 | sk = unix_from_bucket(seq, pos); | |
2297 | if (sk) | |
2298 | return sk; | |
2299 | ||
2300 | next_bucket: | |
2301 | bucket = get_bucket(*pos) + 1; | |
2302 | *pos = set_bucket_offset(bucket, 1); | |
2303 | } while (bucket < ARRAY_SIZE(unix_socket_table)); | |
2304 | ||
1da177e4 LT |
2305 | return NULL; |
2306 | } | |
2307 | ||
1da177e4 | 2308 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
9a429c49 | 2309 | __acquires(unix_table_lock) |
1da177e4 | 2310 | { |
fbe9cc4a | 2311 | spin_lock(&unix_table_lock); |
7123aaa3 ED |
2312 | |
2313 | if (!*pos) | |
2314 | return SEQ_START_TOKEN; | |
2315 | ||
2316 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) | |
2317 | return NULL; | |
2318 | ||
2319 | return unix_next_socket(seq, NULL, pos); | |
1da177e4 LT |
2320 | } |
2321 | ||
2322 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2323 | { | |
2324 | ++*pos; | |
7123aaa3 | 2325 | return unix_next_socket(seq, v, pos); |
1da177e4 LT |
2326 | } |
2327 | ||
2328 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2329 | __releases(unix_table_lock) |
1da177e4 | 2330 | { |
fbe9cc4a | 2331 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2332 | } |
2333 | ||
2334 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2335 | { | |
ac7bfa62 | 2336 | |
b9f3124f | 2337 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
2338 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2339 | "Inode Path\n"); | |
2340 | else { | |
2341 | struct sock *s = v; | |
2342 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2343 | unix_state_lock(s); |
1da177e4 | 2344 | |
71338aa7 | 2345 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 LT |
2346 | s, |
2347 | atomic_read(&s->sk_refcnt), | |
2348 | 0, | |
2349 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2350 | s->sk_type, | |
2351 | s->sk_socket ? | |
2352 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2353 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2354 | sock_i_ino(s)); | |
2355 | ||
2356 | if (u->addr) { | |
2357 | int i, len; | |
2358 | seq_putc(seq, ' '); | |
2359 | ||
2360 | i = 0; | |
2361 | len = u->addr->len - sizeof(short); | |
2362 | if (!UNIX_ABSTRACT(s)) | |
2363 | len--; | |
2364 | else { | |
2365 | seq_putc(seq, '@'); | |
2366 | i++; | |
2367 | } | |
2368 | for ( ; i < len; i++) | |
2369 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2370 | } | |
1c92b4e5 | 2371 | unix_state_unlock(s); |
1da177e4 LT |
2372 | seq_putc(seq, '\n'); |
2373 | } | |
2374 | ||
2375 | return 0; | |
2376 | } | |
2377 | ||
56b3d975 | 2378 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2379 | .start = unix_seq_start, |
2380 | .next = unix_seq_next, | |
2381 | .stop = unix_seq_stop, | |
2382 | .show = unix_seq_show, | |
2383 | }; | |
2384 | ||
1da177e4 LT |
2385 | static int unix_seq_open(struct inode *inode, struct file *file) |
2386 | { | |
e372c414 | 2387 | return seq_open_net(inode, file, &unix_seq_ops, |
8b51b064 | 2388 | sizeof(struct seq_net_private)); |
1da177e4 LT |
2389 | } |
2390 | ||
da7071d7 | 2391 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2392 | .owner = THIS_MODULE, |
2393 | .open = unix_seq_open, | |
2394 | .read = seq_read, | |
2395 | .llseek = seq_lseek, | |
e372c414 | 2396 | .release = seq_release_net, |
1da177e4 LT |
2397 | }; |
2398 | ||
2399 | #endif | |
2400 | ||
ec1b4cf7 | 2401 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
2402 | .family = PF_UNIX, |
2403 | .create = unix_create, | |
2404 | .owner = THIS_MODULE, | |
2405 | }; | |
2406 | ||
097e66c5 | 2407 | |
2c8c1e72 | 2408 | static int __net_init unix_net_init(struct net *net) |
097e66c5 DL |
2409 | { |
2410 | int error = -ENOMEM; | |
2411 | ||
a0a53c8b | 2412 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
2413 | if (unix_sysctl_register(net)) |
2414 | goto out; | |
d392e497 | 2415 | |
097e66c5 | 2416 | #ifdef CONFIG_PROC_FS |
d4beaa66 | 2417 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { |
1597fbc0 | 2418 | unix_sysctl_unregister(net); |
097e66c5 | 2419 | goto out; |
1597fbc0 | 2420 | } |
097e66c5 DL |
2421 | #endif |
2422 | error = 0; | |
2423 | out: | |
48dcc33e | 2424 | return error; |
097e66c5 DL |
2425 | } |
2426 | ||
2c8c1e72 | 2427 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 2428 | { |
1597fbc0 | 2429 | unix_sysctl_unregister(net); |
ece31ffd | 2430 | remove_proc_entry("unix", net->proc_net); |
097e66c5 DL |
2431 | } |
2432 | ||
2433 | static struct pernet_operations unix_net_ops = { | |
2434 | .init = unix_net_init, | |
2435 | .exit = unix_net_exit, | |
2436 | }; | |
2437 | ||
1da177e4 LT |
2438 | static int __init af_unix_init(void) |
2439 | { | |
2440 | int rc = -1; | |
1da177e4 | 2441 | |
b4fff5f8 | 2442 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 LT |
2443 | |
2444 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 | 2445 | if (rc != 0) { |
5cc208be | 2446 | pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); |
1da177e4 LT |
2447 | goto out; |
2448 | } | |
2449 | ||
2450 | sock_register(&unix_family_ops); | |
097e66c5 | 2451 | register_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2452 | out: |
2453 | return rc; | |
2454 | } | |
2455 | ||
2456 | static void __exit af_unix_exit(void) | |
2457 | { | |
2458 | sock_unregister(PF_UNIX); | |
1da177e4 | 2459 | proto_unregister(&unix_proto); |
097e66c5 | 2460 | unregister_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2461 | } |
2462 | ||
3d366960 DW |
2463 | /* Earlier than device_initcall() so that other drivers invoking |
2464 | request_module() don't end up in a loop when modprobe tries | |
2465 | to use a UNIX socket. But later than subsys_initcall() because | |
2466 | we depend on stuff initialised there */ | |
2467 | fs_initcall(af_unix_init); | |
1da177e4 LT |
2468 | module_exit(af_unix_exit); |
2469 | ||
2470 | MODULE_LICENSE("GPL"); | |
2471 | MODULE_ALIAS_NETPROTO(PF_UNIX); |