Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NET4: Implementation of BSD Unix domain sockets. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
1da177e4 LT |
11 | * Fixes: |
12 | * Linus Torvalds : Assorted bug cures. | |
13 | * Niibe Yutaka : async I/O support. | |
14 | * Carsten Paeth : PF_UNIX check, address fixes. | |
15 | * Alan Cox : Limit size of allocated blocks. | |
16 | * Alan Cox : Fixed the stupid socketpair bug. | |
17 | * Alan Cox : BSD compatibility fine tuning. | |
18 | * Alan Cox : Fixed a bug in connect when interrupted. | |
19 | * Alan Cox : Sorted out a proper draft version of | |
20 | * file descriptor passing hacked up from | |
21 | * Mike Shaver's work. | |
22 | * Marty Leisner : Fixes to fd passing | |
23 | * Nick Nevin : recvmsg bugfix. | |
24 | * Alan Cox : Started proper garbage collector | |
25 | * Heiko EiBfeldt : Missing verify_area check | |
26 | * Alan Cox : Started POSIXisms | |
27 | * Andreas Schwab : Replace inode by dentry for proper | |
28 | * reference counting | |
29 | * Kirk Petersen : Made this a module | |
30 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. | |
31 | * Lots of bug fixes. | |
32 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces | |
33 | * by above two patches. | |
34 | * Andrea Arcangeli : If possible we block in connect(2) | |
35 | * if the max backlog of the listen socket | |
36 | * is been reached. This won't break | |
37 | * old apps and it will avoid huge amount | |
38 | * of socks hashed (this for unix_gc() | |
39 | * performances reasons). | |
40 | * Security fix that limits the max | |
41 | * number of socks to 2*max_files and | |
42 | * the number of skb queueable in the | |
43 | * dgram receiver. | |
44 | * Artur Skawina : Hash function optimizations | |
45 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) | |
46 | * Malcolm Beattie : Set peercred for socketpair | |
47 | * Michal Ostrowski : Module initialization cleanup. | |
48 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, | |
49 | * the core infrastructure is doing that | |
50 | * for all net proto families now (2.5.69+) | |
51 | * | |
52 | * | |
53 | * Known differences from reference BSD that was tested: | |
54 | * | |
55 | * [TO FIX] | |
56 | * ECONNREFUSED is not returned from one end of a connected() socket to the | |
57 | * other the moment one end closes. | |
58 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark | |
59 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). | |
60 | * [NOT TO FIX] | |
61 | * accept() returns a path name even if the connecting socket has closed | |
62 | * in the meantime (BSD loses the path and gives up). | |
63 | * accept() returns 0 length path for an unbound connector. BSD returns 16 | |
64 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) | |
65 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. | |
66 | * BSD af_unix apparently has connect forgetting to block properly. | |
67 | * (need to check this with the POSIX spec in detail) | |
68 | * | |
69 | * Differences from 2.0.0-11-... (ANK) | |
70 | * Bug fixes and improvements. | |
71 | * - client shutdown killed server socket. | |
72 | * - removed all useless cli/sti pairs. | |
73 | * | |
74 | * Semantic changes/extensions. | |
75 | * - generic control message passing. | |
76 | * - SCM_CREDENTIALS control message. | |
77 | * - "Abstract" (not FS based) socket bindings. | |
78 | * Abstract names are sequences of bytes (not zero terminated) | |
79 | * started by 0, so that this name space does not intersect | |
80 | * with BSD names. | |
81 | */ | |
82 | ||
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 | { |
0a13404d | 166 | unsigned int hash = (__force unsigned int)csum_fold(n); |
95c96174 | 167 | |
1da177e4 LT |
168 | hash ^= hash>>8; |
169 | return hash&(UNIX_HASH_SIZE-1); | |
170 | } | |
171 | ||
172 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
173 | ||
174 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
175 | { | |
176 | return unix_peer(osk) == sk; | |
177 | } | |
178 | ||
179 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
180 | { | |
6eba6a37 | 181 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
182 | } |
183 | ||
3c73419c RW |
184 | static inline int unix_recvq_full(struct sock const *sk) |
185 | { | |
186 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
187 | } | |
188 | ||
fa7ff56f | 189 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
190 | { |
191 | struct sock *peer; | |
192 | ||
1c92b4e5 | 193 | unix_state_lock(s); |
1da177e4 LT |
194 | peer = unix_peer(s); |
195 | if (peer) | |
196 | sock_hold(peer); | |
1c92b4e5 | 197 | unix_state_unlock(s); |
1da177e4 LT |
198 | return peer; |
199 | } | |
fa7ff56f | 200 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 LT |
201 | |
202 | static inline void unix_release_addr(struct unix_address *addr) | |
203 | { | |
204 | if (atomic_dec_and_test(&addr->refcnt)) | |
205 | kfree(addr); | |
206 | } | |
207 | ||
208 | /* | |
209 | * Check unix socket name: | |
210 | * - should be not zero length. | |
211 | * - if started by not zero, should be NULL terminated (FS object) | |
212 | * - if started by zero, it is abstract name. | |
213 | */ | |
ac7bfa62 | 214 | |
95c96174 | 215 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
1da177e4 LT |
216 | { |
217 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
218 | return -EINVAL; | |
219 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
220 | return -EINVAL; | |
221 | if (sunaddr->sun_path[0]) { | |
222 | /* | |
223 | * This may look like an off by one error but it is a bit more | |
224 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
25985edc | 225 | * sun_path[108] doesn't as such exist. However in kernel space |
1da177e4 LT |
226 | * we are guaranteed that it is a valid memory location in our |
227 | * kernel address buffer. | |
228 | */ | |
e27dfcea | 229 | ((char *)sunaddr)[len] = 0; |
1da177e4 LT |
230 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
231 | return len; | |
232 | } | |
233 | ||
07f0757a | 234 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
1da177e4 LT |
235 | return len; |
236 | } | |
237 | ||
238 | static void __unix_remove_socket(struct sock *sk) | |
239 | { | |
240 | sk_del_node_init(sk); | |
241 | } | |
242 | ||
243 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
244 | { | |
547b792c | 245 | WARN_ON(!sk_unhashed(sk)); |
1da177e4 LT |
246 | sk_add_node(sk, list); |
247 | } | |
248 | ||
249 | static inline void unix_remove_socket(struct sock *sk) | |
250 | { | |
fbe9cc4a | 251 | spin_lock(&unix_table_lock); |
1da177e4 | 252 | __unix_remove_socket(sk); |
fbe9cc4a | 253 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
254 | } |
255 | ||
256 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
257 | { | |
fbe9cc4a | 258 | spin_lock(&unix_table_lock); |
1da177e4 | 259 | __unix_insert_socket(list, sk); |
fbe9cc4a | 260 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
261 | } |
262 | ||
097e66c5 DL |
263 | static struct sock *__unix_find_socket_byname(struct net *net, |
264 | struct sockaddr_un *sunname, | |
95c96174 | 265 | int len, int type, unsigned int hash) |
1da177e4 LT |
266 | { |
267 | struct sock *s; | |
1da177e4 | 268 | |
b67bfe0d | 269 | sk_for_each(s, &unix_socket_table[hash ^ type]) { |
1da177e4 LT |
270 | struct unix_sock *u = unix_sk(s); |
271 | ||
878628fb | 272 | if (!net_eq(sock_net(s), net)) |
097e66c5 DL |
273 | continue; |
274 | ||
1da177e4 LT |
275 | if (u->addr->len == len && |
276 | !memcmp(u->addr->name, sunname, len)) | |
277 | goto found; | |
278 | } | |
279 | s = NULL; | |
280 | found: | |
281 | return s; | |
282 | } | |
283 | ||
097e66c5 DL |
284 | static inline struct sock *unix_find_socket_byname(struct net *net, |
285 | struct sockaddr_un *sunname, | |
1da177e4 | 286 | int len, int type, |
95c96174 | 287 | unsigned int hash) |
1da177e4 LT |
288 | { |
289 | struct sock *s; | |
290 | ||
fbe9cc4a | 291 | spin_lock(&unix_table_lock); |
097e66c5 | 292 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
293 | if (s) |
294 | sock_hold(s); | |
fbe9cc4a | 295 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
296 | return s; |
297 | } | |
298 | ||
6616f788 | 299 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 LT |
300 | { |
301 | struct sock *s; | |
1da177e4 | 302 | |
fbe9cc4a | 303 | spin_lock(&unix_table_lock); |
b67bfe0d | 304 | sk_for_each(s, |
1da177e4 | 305 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
40ffe67d | 306 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 307 | |
a25b376b | 308 | if (dentry && d_backing_inode(dentry) == i) { |
1da177e4 LT |
309 | sock_hold(s); |
310 | goto found; | |
311 | } | |
312 | } | |
313 | s = NULL; | |
314 | found: | |
fbe9cc4a | 315 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
316 | return s; |
317 | } | |
318 | ||
319 | static inline int unix_writable(struct sock *sk) | |
320 | { | |
321 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
322 | } | |
323 | ||
324 | static void unix_write_space(struct sock *sk) | |
325 | { | |
43815482 ED |
326 | struct socket_wq *wq; |
327 | ||
328 | rcu_read_lock(); | |
1da177e4 | 329 | if (unix_writable(sk)) { |
43815482 ED |
330 | wq = rcu_dereference(sk->sk_wq); |
331 | if (wq_has_sleeper(wq)) | |
67426b75 ED |
332 | wake_up_interruptible_sync_poll(&wq->wait, |
333 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
8d8ad9d7 | 334 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 335 | } |
43815482 | 336 | rcu_read_unlock(); |
1da177e4 LT |
337 | } |
338 | ||
339 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
340 | * queue of packets arrived from previous peer. First, it allows to do | |
341 | * flow control based only on wmem_alloc; second, sk connected to peer | |
342 | * may receive messages only from that peer. */ | |
343 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
344 | { | |
b03efcfb | 345 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
346 | skb_queue_purge(&sk->sk_receive_queue); |
347 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
348 | ||
349 | /* If one link of bidirectional dgram pipe is disconnected, | |
350 | * we signal error. Messages are lost. Do not make this, | |
351 | * when peer was not connected to us. | |
352 | */ | |
353 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
354 | other->sk_err = ECONNRESET; | |
355 | other->sk_error_report(other); | |
356 | } | |
357 | } | |
358 | } | |
359 | ||
360 | static void unix_sock_destructor(struct sock *sk) | |
361 | { | |
362 | struct unix_sock *u = unix_sk(sk); | |
363 | ||
364 | skb_queue_purge(&sk->sk_receive_queue); | |
365 | ||
547b792c IJ |
366 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
367 | WARN_ON(!sk_unhashed(sk)); | |
368 | WARN_ON(sk->sk_socket); | |
1da177e4 | 369 | if (!sock_flag(sk, SOCK_DEAD)) { |
5cc208be | 370 | pr_info("Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
371 | return; |
372 | } | |
373 | ||
374 | if (u->addr) | |
375 | unix_release_addr(u->addr); | |
376 | ||
518de9b3 | 377 | atomic_long_dec(&unix_nr_socks); |
6f756a8c | 378 | local_bh_disable(); |
a8076d8d | 379 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
6f756a8c | 380 | local_bh_enable(); |
1da177e4 | 381 | #ifdef UNIX_REFCNT_DEBUG |
5cc208be | 382 | pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk, |
518de9b3 | 383 | atomic_long_read(&unix_nr_socks)); |
1da177e4 LT |
384 | #endif |
385 | } | |
386 | ||
ded34e0f | 387 | static void unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
388 | { |
389 | struct unix_sock *u = unix_sk(sk); | |
40ffe67d | 390 | struct path path; |
1da177e4 LT |
391 | struct sock *skpair; |
392 | struct sk_buff *skb; | |
393 | int state; | |
394 | ||
395 | unix_remove_socket(sk); | |
396 | ||
397 | /* Clear state */ | |
1c92b4e5 | 398 | unix_state_lock(sk); |
1da177e4 LT |
399 | sock_orphan(sk); |
400 | sk->sk_shutdown = SHUTDOWN_MASK; | |
40ffe67d AV |
401 | path = u->path; |
402 | u->path.dentry = NULL; | |
403 | u->path.mnt = NULL; | |
1da177e4 LT |
404 | state = sk->sk_state; |
405 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 406 | unix_state_unlock(sk); |
1da177e4 LT |
407 | |
408 | wake_up_interruptible_all(&u->peer_wait); | |
409 | ||
e27dfcea | 410 | skpair = unix_peer(sk); |
1da177e4 | 411 | |
e27dfcea | 412 | if (skpair != NULL) { |
1da177e4 | 413 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 414 | unix_state_lock(skpair); |
1da177e4 LT |
415 | /* No more writes */ |
416 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
417 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
418 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 419 | unix_state_unlock(skpair); |
1da177e4 | 420 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 421 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 LT |
422 | } |
423 | sock_put(skpair); /* It may now die */ | |
424 | unix_peer(sk) = NULL; | |
425 | } | |
426 | ||
427 | /* Try to flush out this socket. Throw out buffers at least */ | |
428 | ||
429 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 430 | if (state == TCP_LISTEN) |
1da177e4 LT |
431 | unix_release_sock(skb->sk, 1); |
432 | /* passed fds are erased in the kfree_skb hook */ | |
433 | kfree_skb(skb); | |
434 | } | |
435 | ||
40ffe67d AV |
436 | if (path.dentry) |
437 | path_put(&path); | |
1da177e4 LT |
438 | |
439 | sock_put(sk); | |
440 | ||
441 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
442 | ||
443 | /* | |
e04dae84 | 444 | * Fixme: BSD difference: In BSD all sockets connected to us get |
1da177e4 LT |
445 | * ECONNRESET and we die on the spot. In Linux we behave |
446 | * like files and pipes do and wait for the last | |
447 | * dereference. | |
448 | * | |
449 | * Can't we simply set sock->err? | |
450 | * | |
451 | * What the above comment does talk about? --ANK(980817) | |
452 | */ | |
453 | ||
9305cfa4 | 454 | if (unix_tot_inflight) |
ac7bfa62 | 455 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
456 | } |
457 | ||
109f6e39 EB |
458 | static void init_peercred(struct sock *sk) |
459 | { | |
460 | put_pid(sk->sk_peer_pid); | |
461 | if (sk->sk_peer_cred) | |
462 | put_cred(sk->sk_peer_cred); | |
463 | sk->sk_peer_pid = get_pid(task_tgid(current)); | |
464 | sk->sk_peer_cred = get_current_cred(); | |
465 | } | |
466 | ||
467 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
468 | { | |
469 | put_pid(sk->sk_peer_pid); | |
470 | if (sk->sk_peer_cred) | |
471 | put_cred(sk->sk_peer_cred); | |
472 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); | |
473 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
474 | } | |
475 | ||
1da177e4 LT |
476 | static int unix_listen(struct socket *sock, int backlog) |
477 | { | |
478 | int err; | |
479 | struct sock *sk = sock->sk; | |
480 | struct unix_sock *u = unix_sk(sk); | |
109f6e39 | 481 | struct pid *old_pid = NULL; |
1da177e4 LT |
482 | |
483 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
484 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
485 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
486 | err = -EINVAL; |
487 | if (!u->addr) | |
6eba6a37 | 488 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 489 | unix_state_lock(sk); |
1da177e4 LT |
490 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
491 | goto out_unlock; | |
492 | if (backlog > sk->sk_max_ack_backlog) | |
493 | wake_up_interruptible_all(&u->peer_wait); | |
494 | sk->sk_max_ack_backlog = backlog; | |
495 | sk->sk_state = TCP_LISTEN; | |
496 | /* set credentials so connect can copy them */ | |
109f6e39 | 497 | init_peercred(sk); |
1da177e4 LT |
498 | err = 0; |
499 | ||
500 | out_unlock: | |
1c92b4e5 | 501 | unix_state_unlock(sk); |
109f6e39 | 502 | put_pid(old_pid); |
1da177e4 LT |
503 | out: |
504 | return err; | |
505 | } | |
506 | ||
507 | static int unix_release(struct socket *); | |
508 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
509 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
510 | int addr_len, int flags); | |
511 | static int unix_socketpair(struct socket *, struct socket *); | |
512 | static int unix_accept(struct socket *, struct socket *, int); | |
513 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
514 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
ec0d215f RW |
515 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
516 | poll_table *); | |
1da177e4 LT |
517 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
518 | static int unix_shutdown(struct socket *, int); | |
1b784140 YX |
519 | static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t); |
520 | static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
521 | static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t); | |
522 | static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
1da177e4 LT |
523 | static int unix_dgram_connect(struct socket *, struct sockaddr *, |
524 | int, int); | |
1b784140 YX |
525 | static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t); |
526 | static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t, | |
527 | int); | |
1da177e4 | 528 | |
12663bfc | 529 | static int unix_set_peek_off(struct sock *sk, int val) |
f55bb7f9 PE |
530 | { |
531 | struct unix_sock *u = unix_sk(sk); | |
532 | ||
12663bfc SL |
533 | if (mutex_lock_interruptible(&u->readlock)) |
534 | return -EINTR; | |
535 | ||
f55bb7f9 PE |
536 | sk->sk_peek_off = val; |
537 | mutex_unlock(&u->readlock); | |
12663bfc SL |
538 | |
539 | return 0; | |
f55bb7f9 PE |
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 | |
37ab4fa7 SL |
717 | err = mutex_lock_interruptible(&u->readlock); |
718 | if (err) | |
719 | return err; | |
1da177e4 LT |
720 | |
721 | err = 0; | |
722 | if (u->addr) | |
723 | goto out; | |
724 | ||
725 | err = -ENOMEM; | |
0da974f4 | 726 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
727 | if (!addr) |
728 | goto out; | |
729 | ||
1da177e4 LT |
730 | addr->name->sun_family = AF_UNIX; |
731 | atomic_set(&addr->refcnt, 1); | |
732 | ||
733 | retry: | |
734 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
07f0757a | 735 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
1da177e4 | 736 | |
fbe9cc4a | 737 | spin_lock(&unix_table_lock); |
1da177e4 LT |
738 | ordernum = (ordernum+1)&0xFFFFF; |
739 | ||
097e66c5 | 740 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
1da177e4 | 741 | addr->hash)) { |
fbe9cc4a | 742 | spin_unlock(&unix_table_lock); |
8df73ff9 TH |
743 | /* |
744 | * __unix_find_socket_byname() may take long time if many names | |
745 | * are already in use. | |
746 | */ | |
747 | cond_resched(); | |
748 | /* Give up if all names seems to be in use. */ | |
749 | if (retries++ == 0xFFFFF) { | |
750 | err = -ENOSPC; | |
751 | kfree(addr); | |
752 | goto out; | |
753 | } | |
1da177e4 LT |
754 | goto retry; |
755 | } | |
756 | addr->hash ^= sk->sk_type; | |
757 | ||
758 | __unix_remove_socket(sk); | |
759 | u->addr = addr; | |
760 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 761 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
762 | err = 0; |
763 | ||
57b47a53 | 764 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
765 | return err; |
766 | } | |
767 | ||
097e66c5 DL |
768 | static struct sock *unix_find_other(struct net *net, |
769 | struct sockaddr_un *sunname, int len, | |
95c96174 | 770 | int type, unsigned int hash, int *error) |
1da177e4 LT |
771 | { |
772 | struct sock *u; | |
421748ec | 773 | struct path path; |
1da177e4 | 774 | int err = 0; |
ac7bfa62 | 775 | |
1da177e4 | 776 | if (sunname->sun_path[0]) { |
421748ec AV |
777 | struct inode *inode; |
778 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); | |
1da177e4 LT |
779 | if (err) |
780 | goto fail; | |
a25b376b | 781 | inode = d_backing_inode(path.dentry); |
421748ec | 782 | err = inode_permission(inode, MAY_WRITE); |
1da177e4 LT |
783 | if (err) |
784 | goto put_fail; | |
785 | ||
786 | err = -ECONNREFUSED; | |
421748ec | 787 | if (!S_ISSOCK(inode->i_mode)) |
1da177e4 | 788 | goto put_fail; |
6616f788 | 789 | u = unix_find_socket_byinode(inode); |
1da177e4 LT |
790 | if (!u) |
791 | goto put_fail; | |
792 | ||
793 | if (u->sk_type == type) | |
68ac1234 | 794 | touch_atime(&path); |
1da177e4 | 795 | |
421748ec | 796 | path_put(&path); |
1da177e4 | 797 | |
e27dfcea | 798 | err = -EPROTOTYPE; |
1da177e4 LT |
799 | if (u->sk_type != type) { |
800 | sock_put(u); | |
801 | goto fail; | |
802 | } | |
803 | } else { | |
804 | err = -ECONNREFUSED; | |
e27dfcea | 805 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
1da177e4 LT |
806 | if (u) { |
807 | struct dentry *dentry; | |
40ffe67d | 808 | dentry = unix_sk(u)->path.dentry; |
1da177e4 | 809 | if (dentry) |
68ac1234 | 810 | touch_atime(&unix_sk(u)->path); |
1da177e4 LT |
811 | } else |
812 | goto fail; | |
813 | } | |
814 | return u; | |
815 | ||
816 | put_fail: | |
421748ec | 817 | path_put(&path); |
1da177e4 | 818 | fail: |
e27dfcea | 819 | *error = err; |
1da177e4 LT |
820 | return NULL; |
821 | } | |
822 | ||
faf02010 AV |
823 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) |
824 | { | |
825 | struct dentry *dentry; | |
826 | struct path path; | |
827 | int err = 0; | |
828 | /* | |
829 | * Get the parent directory, calculate the hash for last | |
830 | * component. | |
831 | */ | |
832 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); | |
833 | err = PTR_ERR(dentry); | |
834 | if (IS_ERR(dentry)) | |
835 | return err; | |
836 | ||
837 | /* | |
838 | * All right, let's create it. | |
839 | */ | |
840 | err = security_path_mknod(&path, dentry, mode, 0); | |
841 | if (!err) { | |
ee8ac4d6 | 842 | err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0); |
faf02010 AV |
843 | if (!err) { |
844 | res->mnt = mntget(path.mnt); | |
845 | res->dentry = dget(dentry); | |
846 | } | |
847 | } | |
848 | done_path_create(&path, dentry); | |
849 | return err; | |
850 | } | |
1da177e4 LT |
851 | |
852 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
853 | { | |
854 | struct sock *sk = sock->sk; | |
3b1e0a65 | 855 | struct net *net = sock_net(sk); |
1da177e4 | 856 | struct unix_sock *u = unix_sk(sk); |
e27dfcea | 857 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
dae6ad8f | 858 | char *sun_path = sunaddr->sun_path; |
1da177e4 | 859 | int err; |
95c96174 | 860 | unsigned int hash; |
1da177e4 LT |
861 | struct unix_address *addr; |
862 | struct hlist_head *list; | |
863 | ||
864 | err = -EINVAL; | |
865 | if (sunaddr->sun_family != AF_UNIX) | |
866 | goto out; | |
867 | ||
e27dfcea | 868 | if (addr_len == sizeof(short)) { |
1da177e4 LT |
869 | err = unix_autobind(sock); |
870 | goto out; | |
871 | } | |
872 | ||
873 | err = unix_mkname(sunaddr, addr_len, &hash); | |
874 | if (err < 0) | |
875 | goto out; | |
876 | addr_len = err; | |
877 | ||
37ab4fa7 SL |
878 | err = mutex_lock_interruptible(&u->readlock); |
879 | if (err) | |
880 | goto out; | |
1da177e4 LT |
881 | |
882 | err = -EINVAL; | |
883 | if (u->addr) | |
884 | goto out_up; | |
885 | ||
886 | err = -ENOMEM; | |
887 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
888 | if (!addr) | |
889 | goto out_up; | |
890 | ||
891 | memcpy(addr->name, sunaddr, addr_len); | |
892 | addr->len = addr_len; | |
893 | addr->hash = hash ^ sk->sk_type; | |
894 | atomic_set(&addr->refcnt, 1); | |
895 | ||
dae6ad8f | 896 | if (sun_path[0]) { |
faf02010 AV |
897 | struct path path; |
898 | umode_t mode = S_IFSOCK | | |
ce3b0f8d | 899 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
faf02010 AV |
900 | err = unix_mknod(sun_path, mode, &path); |
901 | if (err) { | |
902 | if (err == -EEXIST) | |
903 | err = -EADDRINUSE; | |
904 | unix_release_addr(addr); | |
905 | goto out_up; | |
906 | } | |
1da177e4 | 907 | addr->hash = UNIX_HASH_SIZE; |
a25b376b | 908 | hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE-1); |
faf02010 AV |
909 | spin_lock(&unix_table_lock); |
910 | u->path = path; | |
911 | list = &unix_socket_table[hash]; | |
912 | } else { | |
913 | spin_lock(&unix_table_lock); | |
1da177e4 | 914 | err = -EADDRINUSE; |
097e66c5 | 915 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
1da177e4 LT |
916 | sk->sk_type, hash)) { |
917 | unix_release_addr(addr); | |
918 | goto out_unlock; | |
919 | } | |
920 | ||
921 | list = &unix_socket_table[addr->hash]; | |
1da177e4 LT |
922 | } |
923 | ||
924 | err = 0; | |
925 | __unix_remove_socket(sk); | |
926 | u->addr = addr; | |
927 | __unix_insert_socket(list, sk); | |
928 | ||
929 | out_unlock: | |
fbe9cc4a | 930 | spin_unlock(&unix_table_lock); |
1da177e4 | 931 | out_up: |
57b47a53 | 932 | mutex_unlock(&u->readlock); |
1da177e4 LT |
933 | out: |
934 | return err; | |
1da177e4 LT |
935 | } |
936 | ||
278a3de5 DM |
937 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
938 | { | |
939 | if (unlikely(sk1 == sk2) || !sk2) { | |
940 | unix_state_lock(sk1); | |
941 | return; | |
942 | } | |
943 | if (sk1 < sk2) { | |
944 | unix_state_lock(sk1); | |
945 | unix_state_lock_nested(sk2); | |
946 | } else { | |
947 | unix_state_lock(sk2); | |
948 | unix_state_lock_nested(sk1); | |
949 | } | |
950 | } | |
951 | ||
952 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
953 | { | |
954 | if (unlikely(sk1 == sk2) || !sk2) { | |
955 | unix_state_unlock(sk1); | |
956 | return; | |
957 | } | |
958 | unix_state_unlock(sk1); | |
959 | unix_state_unlock(sk2); | |
960 | } | |
961 | ||
1da177e4 LT |
962 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
963 | int alen, int flags) | |
964 | { | |
965 | struct sock *sk = sock->sk; | |
3b1e0a65 | 966 | struct net *net = sock_net(sk); |
e27dfcea | 967 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
1da177e4 | 968 | struct sock *other; |
95c96174 | 969 | unsigned int hash; |
1da177e4 LT |
970 | int err; |
971 | ||
972 | if (addr->sa_family != AF_UNSPEC) { | |
973 | err = unix_mkname(sunaddr, alen, &hash); | |
974 | if (err < 0) | |
975 | goto out; | |
976 | alen = err; | |
977 | ||
978 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
979 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
980 | goto out; | |
981 | ||
278a3de5 | 982 | restart: |
e27dfcea | 983 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
1da177e4 LT |
984 | if (!other) |
985 | goto out; | |
986 | ||
278a3de5 DM |
987 | unix_state_double_lock(sk, other); |
988 | ||
989 | /* Apparently VFS overslept socket death. Retry. */ | |
990 | if (sock_flag(other, SOCK_DEAD)) { | |
991 | unix_state_double_unlock(sk, other); | |
992 | sock_put(other); | |
993 | goto restart; | |
994 | } | |
1da177e4 LT |
995 | |
996 | err = -EPERM; | |
997 | if (!unix_may_send(sk, other)) | |
998 | goto out_unlock; | |
999 | ||
1000 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1001 | if (err) | |
1002 | goto out_unlock; | |
1003 | ||
1004 | } else { | |
1005 | /* | |
1006 | * 1003.1g breaking connected state with AF_UNSPEC | |
1007 | */ | |
1008 | other = NULL; | |
278a3de5 | 1009 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1010 | } |
1011 | ||
1012 | /* | |
1013 | * If it was connected, reconnect. | |
1014 | */ | |
1015 | if (unix_peer(sk)) { | |
1016 | struct sock *old_peer = unix_peer(sk); | |
e27dfcea | 1017 | unix_peer(sk) = other; |
278a3de5 | 1018 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1019 | |
1020 | if (other != old_peer) | |
1021 | unix_dgram_disconnected(sk, old_peer); | |
1022 | sock_put(old_peer); | |
1023 | } else { | |
e27dfcea | 1024 | unix_peer(sk) = other; |
278a3de5 | 1025 | unix_state_double_unlock(sk, other); |
1da177e4 | 1026 | } |
ac7bfa62 | 1027 | return 0; |
1da177e4 LT |
1028 | |
1029 | out_unlock: | |
278a3de5 | 1030 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1031 | sock_put(other); |
1032 | out: | |
1033 | return err; | |
1034 | } | |
1035 | ||
1036 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
1037 | { | |
1038 | struct unix_sock *u = unix_sk(other); | |
1039 | int sched; | |
1040 | DEFINE_WAIT(wait); | |
1041 | ||
1042 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1043 | ||
1044 | sched = !sock_flag(other, SOCK_DEAD) && | |
1045 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
3c73419c | 1046 | unix_recvq_full(other); |
1da177e4 | 1047 | |
1c92b4e5 | 1048 | unix_state_unlock(other); |
1da177e4 LT |
1049 | |
1050 | if (sched) | |
1051 | timeo = schedule_timeout(timeo); | |
1052 | ||
1053 | finish_wait(&u->peer_wait, &wait); | |
1054 | return timeo; | |
1055 | } | |
1056 | ||
1057 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1058 | int addr_len, int flags) | |
1059 | { | |
e27dfcea | 1060 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1da177e4 | 1061 | struct sock *sk = sock->sk; |
3b1e0a65 | 1062 | struct net *net = sock_net(sk); |
1da177e4 LT |
1063 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1064 | struct sock *newsk = NULL; | |
1065 | struct sock *other = NULL; | |
1066 | struct sk_buff *skb = NULL; | |
95c96174 | 1067 | unsigned int hash; |
1da177e4 LT |
1068 | int st; |
1069 | int err; | |
1070 | long timeo; | |
1071 | ||
1072 | err = unix_mkname(sunaddr, addr_len, &hash); | |
1073 | if (err < 0) | |
1074 | goto out; | |
1075 | addr_len = err; | |
1076 | ||
f64f9e71 JP |
1077 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
1078 | (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1079 | goto out; |
1080 | ||
1081 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1082 | ||
1083 | /* First of all allocate resources. | |
1084 | If we will make it after state is locked, | |
1085 | we will have to recheck all again in any case. | |
1086 | */ | |
1087 | ||
1088 | err = -ENOMEM; | |
1089 | ||
1090 | /* create new sock for complete connection */ | |
3b1e0a65 | 1091 | newsk = unix_create1(sock_net(sk), NULL); |
1da177e4 LT |
1092 | if (newsk == NULL) |
1093 | goto out; | |
1094 | ||
1095 | /* Allocate skb for sending to listening sock */ | |
1096 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1097 | if (skb == NULL) | |
1098 | goto out; | |
1099 | ||
1100 | restart: | |
1101 | /* Find listening sock. */ | |
097e66c5 | 1102 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1da177e4 LT |
1103 | if (!other) |
1104 | goto out; | |
1105 | ||
1106 | /* Latch state of peer */ | |
1c92b4e5 | 1107 | unix_state_lock(other); |
1da177e4 LT |
1108 | |
1109 | /* Apparently VFS overslept socket death. Retry. */ | |
1110 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1111 | unix_state_unlock(other); |
1da177e4 LT |
1112 | sock_put(other); |
1113 | goto restart; | |
1114 | } | |
1115 | ||
1116 | err = -ECONNREFUSED; | |
1117 | if (other->sk_state != TCP_LISTEN) | |
1118 | goto out_unlock; | |
77238f2b TS |
1119 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1120 | goto out_unlock; | |
1da177e4 | 1121 | |
3c73419c | 1122 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1123 | err = -EAGAIN; |
1124 | if (!timeo) | |
1125 | goto out_unlock; | |
1126 | ||
1127 | timeo = unix_wait_for_peer(other, timeo); | |
1128 | ||
1129 | err = sock_intr_errno(timeo); | |
1130 | if (signal_pending(current)) | |
1131 | goto out; | |
1132 | sock_put(other); | |
1133 | goto restart; | |
ac7bfa62 | 1134 | } |
1da177e4 LT |
1135 | |
1136 | /* Latch our state. | |
1137 | ||
e5537bfc | 1138 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1139 | drop lock on peer. It is dangerous because deadlock is |
1140 | possible. Connect to self case and simultaneous | |
1141 | attempt to connect are eliminated by checking socket | |
1142 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1143 | check this before attempt to grab lock. | |
1144 | ||
1145 | Well, and we have to recheck the state after socket locked. | |
1146 | */ | |
1147 | st = sk->sk_state; | |
1148 | ||
1149 | switch (st) { | |
1150 | case TCP_CLOSE: | |
1151 | /* This is ok... continue with connect */ | |
1152 | break; | |
1153 | case TCP_ESTABLISHED: | |
1154 | /* Socket is already connected */ | |
1155 | err = -EISCONN; | |
1156 | goto out_unlock; | |
1157 | default: | |
1158 | err = -EINVAL; | |
1159 | goto out_unlock; | |
1160 | } | |
1161 | ||
1c92b4e5 | 1162 | unix_state_lock_nested(sk); |
1da177e4 LT |
1163 | |
1164 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1165 | unix_state_unlock(sk); |
1166 | unix_state_unlock(other); | |
1da177e4 LT |
1167 | sock_put(other); |
1168 | goto restart; | |
1169 | } | |
1170 | ||
3610cda5 | 1171 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1172 | if (err) { |
1c92b4e5 | 1173 | unix_state_unlock(sk); |
1da177e4 LT |
1174 | goto out_unlock; |
1175 | } | |
1176 | ||
1177 | /* The way is open! Fastly set all the necessary fields... */ | |
1178 | ||
1179 | sock_hold(sk); | |
1180 | unix_peer(newsk) = sk; | |
1181 | newsk->sk_state = TCP_ESTABLISHED; | |
1182 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1183 | init_peercred(newsk); |
1da177e4 | 1184 | newu = unix_sk(newsk); |
eaefd110 | 1185 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1186 | otheru = unix_sk(other); |
1187 | ||
1188 | /* copy address information from listening to new sock*/ | |
1189 | if (otheru->addr) { | |
1190 | atomic_inc(&otheru->addr->refcnt); | |
1191 | newu->addr = otheru->addr; | |
1192 | } | |
40ffe67d AV |
1193 | if (otheru->path.dentry) { |
1194 | path_get(&otheru->path); | |
1195 | newu->path = otheru->path; | |
1da177e4 LT |
1196 | } |
1197 | ||
1198 | /* Set credentials */ | |
109f6e39 | 1199 | copy_peercred(sk, other); |
1da177e4 | 1200 | |
1da177e4 LT |
1201 | sock->state = SS_CONNECTED; |
1202 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1203 | sock_hold(newsk); |
1204 | ||
4e857c58 | 1205 | smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */ |
830a1e5c | 1206 | unix_peer(sk) = newsk; |
1da177e4 | 1207 | |
1c92b4e5 | 1208 | unix_state_unlock(sk); |
1da177e4 LT |
1209 | |
1210 | /* take ten and and send info to listening sock */ | |
1211 | spin_lock(&other->sk_receive_queue.lock); | |
1212 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1213 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1214 | unix_state_unlock(other); |
676d2369 | 1215 | other->sk_data_ready(other); |
1da177e4 LT |
1216 | sock_put(other); |
1217 | return 0; | |
1218 | ||
1219 | out_unlock: | |
1220 | if (other) | |
1c92b4e5 | 1221 | unix_state_unlock(other); |
1da177e4 LT |
1222 | |
1223 | out: | |
40d44446 | 1224 | kfree_skb(skb); |
1da177e4 LT |
1225 | if (newsk) |
1226 | unix_release_sock(newsk, 0); | |
1227 | if (other) | |
1228 | sock_put(other); | |
1229 | return err; | |
1230 | } | |
1231 | ||
1232 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1233 | { | |
e27dfcea | 1234 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1235 | |
1236 | /* Join our sockets back to back */ | |
1237 | sock_hold(ska); | |
1238 | sock_hold(skb); | |
e27dfcea JK |
1239 | unix_peer(ska) = skb; |
1240 | unix_peer(skb) = ska; | |
109f6e39 EB |
1241 | init_peercred(ska); |
1242 | init_peercred(skb); | |
1da177e4 LT |
1243 | |
1244 | if (ska->sk_type != SOCK_DGRAM) { | |
1245 | ska->sk_state = TCP_ESTABLISHED; | |
1246 | skb->sk_state = TCP_ESTABLISHED; | |
1247 | socka->state = SS_CONNECTED; | |
1248 | sockb->state = SS_CONNECTED; | |
1249 | } | |
1250 | return 0; | |
1251 | } | |
1252 | ||
90c6bd34 DB |
1253 | static void unix_sock_inherit_flags(const struct socket *old, |
1254 | struct socket *new) | |
1255 | { | |
1256 | if (test_bit(SOCK_PASSCRED, &old->flags)) | |
1257 | set_bit(SOCK_PASSCRED, &new->flags); | |
1258 | if (test_bit(SOCK_PASSSEC, &old->flags)) | |
1259 | set_bit(SOCK_PASSSEC, &new->flags); | |
1260 | } | |
1261 | ||
1da177e4 LT |
1262 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
1263 | { | |
1264 | struct sock *sk = sock->sk; | |
1265 | struct sock *tsk; | |
1266 | struct sk_buff *skb; | |
1267 | int err; | |
1268 | ||
1269 | err = -EOPNOTSUPP; | |
6eba6a37 | 1270 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1271 | goto out; |
1272 | ||
1273 | err = -EINVAL; | |
1274 | if (sk->sk_state != TCP_LISTEN) | |
1275 | goto out; | |
1276 | ||
1277 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1278 | * so that no locks are necessary. | |
1279 | */ | |
1280 | ||
1281 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1282 | if (!skb) { | |
1283 | /* This means receive shutdown. */ | |
1284 | if (err == 0) | |
1285 | err = -EINVAL; | |
1286 | goto out; | |
1287 | } | |
1288 | ||
1289 | tsk = skb->sk; | |
1290 | skb_free_datagram(sk, skb); | |
1291 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1292 | ||
1293 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1294 | unix_state_lock(tsk); |
1da177e4 | 1295 | newsock->state = SS_CONNECTED; |
90c6bd34 | 1296 | unix_sock_inherit_flags(sock, newsock); |
1da177e4 | 1297 | sock_graft(tsk, newsock); |
1c92b4e5 | 1298 | unix_state_unlock(tsk); |
1da177e4 LT |
1299 | return 0; |
1300 | ||
1301 | out: | |
1302 | return err; | |
1303 | } | |
1304 | ||
1305 | ||
1306 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1307 | { | |
1308 | struct sock *sk = sock->sk; | |
1309 | struct unix_sock *u; | |
13cfa97b | 1310 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1311 | int err = 0; |
1312 | ||
1313 | if (peer) { | |
1314 | sk = unix_peer_get(sk); | |
1315 | ||
1316 | err = -ENOTCONN; | |
1317 | if (!sk) | |
1318 | goto out; | |
1319 | err = 0; | |
1320 | } else { | |
1321 | sock_hold(sk); | |
1322 | } | |
1323 | ||
1324 | u = unix_sk(sk); | |
1c92b4e5 | 1325 | unix_state_lock(sk); |
1da177e4 LT |
1326 | if (!u->addr) { |
1327 | sunaddr->sun_family = AF_UNIX; | |
1328 | sunaddr->sun_path[0] = 0; | |
1329 | *uaddr_len = sizeof(short); | |
1330 | } else { | |
1331 | struct unix_address *addr = u->addr; | |
1332 | ||
1333 | *uaddr_len = addr->len; | |
1334 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1335 | } | |
1c92b4e5 | 1336 | unix_state_unlock(sk); |
1da177e4 LT |
1337 | sock_put(sk); |
1338 | out: | |
1339 | return err; | |
1340 | } | |
1341 | ||
1342 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1343 | { | |
1344 | int i; | |
1345 | ||
1346 | scm->fp = UNIXCB(skb).fp; | |
1da177e4 LT |
1347 | UNIXCB(skb).fp = NULL; |
1348 | ||
6eba6a37 | 1349 | for (i = scm->fp->count-1; i >= 0; i--) |
1da177e4 LT |
1350 | unix_notinflight(scm->fp->fp[i]); |
1351 | } | |
1352 | ||
7361c36c | 1353 | static void unix_destruct_scm(struct sk_buff *skb) |
1da177e4 LT |
1354 | { |
1355 | struct scm_cookie scm; | |
1356 | memset(&scm, 0, sizeof(scm)); | |
7361c36c | 1357 | scm.pid = UNIXCB(skb).pid; |
7361c36c EB |
1358 | if (UNIXCB(skb).fp) |
1359 | unix_detach_fds(&scm, skb); | |
1da177e4 LT |
1360 | |
1361 | /* Alas, it calls VFS */ | |
1362 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1363 | scm_destroy(&scm); | |
1364 | sock_wfree(skb); | |
1365 | } | |
1366 | ||
25888e30 ED |
1367 | #define MAX_RECURSION_LEVEL 4 |
1368 | ||
6209344f | 1369 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1da177e4 LT |
1370 | { |
1371 | int i; | |
25888e30 ED |
1372 | unsigned char max_level = 0; |
1373 | int unix_sock_count = 0; | |
1374 | ||
1375 | for (i = scm->fp->count - 1; i >= 0; i--) { | |
1376 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); | |
1377 | ||
1378 | if (sk) { | |
1379 | unix_sock_count++; | |
1380 | max_level = max(max_level, | |
1381 | unix_sk(sk)->recursion_level); | |
1382 | } | |
1383 | } | |
1384 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) | |
1385 | return -ETOOMANYREFS; | |
6209344f MS |
1386 | |
1387 | /* | |
1388 | * Need to duplicate file references for the sake of garbage | |
1389 | * collection. Otherwise a socket in the fps might become a | |
1390 | * candidate for GC while the skb is not yet queued. | |
1391 | */ | |
1392 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); | |
1393 | if (!UNIXCB(skb).fp) | |
1394 | return -ENOMEM; | |
1395 | ||
25888e30 ED |
1396 | if (unix_sock_count) { |
1397 | for (i = scm->fp->count - 1; i >= 0; i--) | |
1398 | unix_inflight(scm->fp->fp[i]); | |
1399 | } | |
1400 | return max_level; | |
1da177e4 LT |
1401 | } |
1402 | ||
f78a5fda | 1403 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1404 | { |
1405 | int err = 0; | |
16e57262 | 1406 | |
f78a5fda | 1407 | UNIXCB(skb).pid = get_pid(scm->pid); |
6b0ee8c0 EB |
1408 | UNIXCB(skb).uid = scm->creds.uid; |
1409 | UNIXCB(skb).gid = scm->creds.gid; | |
7361c36c EB |
1410 | UNIXCB(skb).fp = NULL; |
1411 | if (scm->fp && send_fds) | |
1412 | err = unix_attach_fds(scm, skb); | |
1413 | ||
1414 | skb->destructor = unix_destruct_scm; | |
1415 | return err; | |
1416 | } | |
1417 | ||
16e57262 ED |
1418 | /* |
1419 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1420 | * We include credentials if source or destination socket | |
1421 | * asserted SOCK_PASSCRED. | |
1422 | */ | |
1423 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1424 | const struct sock *other) | |
1425 | { | |
6b0ee8c0 | 1426 | if (UNIXCB(skb).pid) |
16e57262 ED |
1427 | return; |
1428 | if (test_bit(SOCK_PASSCRED, &sock->flags) || | |
25da0e3e EB |
1429 | !other->sk_socket || |
1430 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { | |
16e57262 | 1431 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
6e0895c2 | 1432 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); |
16e57262 ED |
1433 | } |
1434 | } | |
1435 | ||
1da177e4 LT |
1436 | /* |
1437 | * Send AF_UNIX data. | |
1438 | */ | |
1439 | ||
1b784140 YX |
1440 | static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, |
1441 | size_t len) | |
1da177e4 | 1442 | { |
1da177e4 | 1443 | struct sock *sk = sock->sk; |
3b1e0a65 | 1444 | struct net *net = sock_net(sk); |
1da177e4 | 1445 | struct unix_sock *u = unix_sk(sk); |
342dfc30 | 1446 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); |
1da177e4 LT |
1447 | struct sock *other = NULL; |
1448 | int namelen = 0; /* fake GCC */ | |
1449 | int err; | |
95c96174 | 1450 | unsigned int hash; |
f78a5fda | 1451 | struct sk_buff *skb; |
1da177e4 | 1452 | long timeo; |
7cc05662 | 1453 | struct scm_cookie scm; |
25888e30 | 1454 | int max_level; |
eb6a2481 | 1455 | int data_len = 0; |
1da177e4 | 1456 | |
5f23b734 | 1457 | wait_for_unix_gc(); |
7cc05662 | 1458 | err = scm_send(sock, msg, &scm, false); |
1da177e4 LT |
1459 | if (err < 0) |
1460 | return err; | |
1461 | ||
1462 | err = -EOPNOTSUPP; | |
1463 | if (msg->msg_flags&MSG_OOB) | |
1464 | goto out; | |
1465 | ||
1466 | if (msg->msg_namelen) { | |
1467 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1468 | if (err < 0) | |
1469 | goto out; | |
1470 | namelen = err; | |
1471 | } else { | |
1472 | sunaddr = NULL; | |
1473 | err = -ENOTCONN; | |
1474 | other = unix_peer_get(sk); | |
1475 | if (!other) | |
1476 | goto out; | |
1477 | } | |
1478 | ||
f64f9e71 JP |
1479 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
1480 | && (err = unix_autobind(sock)) != 0) | |
1da177e4 LT |
1481 | goto out; |
1482 | ||
1483 | err = -EMSGSIZE; | |
1484 | if (len > sk->sk_sndbuf - 32) | |
1485 | goto out; | |
1486 | ||
31ff6aa5 | 1487 | if (len > SKB_MAX_ALLOC) { |
eb6a2481 ED |
1488 | data_len = min_t(size_t, |
1489 | len - SKB_MAX_ALLOC, | |
1490 | MAX_SKB_FRAGS * PAGE_SIZE); | |
31ff6aa5 KT |
1491 | data_len = PAGE_ALIGN(data_len); |
1492 | ||
1493 | BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE); | |
1494 | } | |
eb6a2481 ED |
1495 | |
1496 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
28d64271 ED |
1497 | msg->msg_flags & MSG_DONTWAIT, &err, |
1498 | PAGE_ALLOC_COSTLY_ORDER); | |
e27dfcea | 1499 | if (skb == NULL) |
1da177e4 LT |
1500 | goto out; |
1501 | ||
7cc05662 | 1502 | err = unix_scm_to_skb(&scm, skb, true); |
25888e30 | 1503 | if (err < 0) |
7361c36c | 1504 | goto out_free; |
25888e30 | 1505 | max_level = err + 1; |
7cc05662 | 1506 | unix_get_secdata(&scm, skb); |
877ce7c1 | 1507 | |
eb6a2481 ED |
1508 | skb_put(skb, len - data_len); |
1509 | skb->data_len = data_len; | |
1510 | skb->len = len; | |
c0371da6 | 1511 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len); |
1da177e4 LT |
1512 | if (err) |
1513 | goto out_free; | |
1514 | ||
1515 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1516 | ||
1517 | restart: | |
1518 | if (!other) { | |
1519 | err = -ECONNRESET; | |
1520 | if (sunaddr == NULL) | |
1521 | goto out_free; | |
1522 | ||
097e66c5 | 1523 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1da177e4 | 1524 | hash, &err); |
e27dfcea | 1525 | if (other == NULL) |
1da177e4 LT |
1526 | goto out_free; |
1527 | } | |
1528 | ||
d6ae3bae AC |
1529 | if (sk_filter(other, skb) < 0) { |
1530 | /* Toss the packet but do not return any error to the sender */ | |
1531 | err = len; | |
1532 | goto out_free; | |
1533 | } | |
1534 | ||
1c92b4e5 | 1535 | unix_state_lock(other); |
1da177e4 LT |
1536 | err = -EPERM; |
1537 | if (!unix_may_send(sk, other)) | |
1538 | goto out_unlock; | |
1539 | ||
1540 | if (sock_flag(other, SOCK_DEAD)) { | |
1541 | /* | |
1542 | * Check with 1003.1g - what should | |
1543 | * datagram error | |
1544 | */ | |
1c92b4e5 | 1545 | unix_state_unlock(other); |
1da177e4 LT |
1546 | sock_put(other); |
1547 | ||
1548 | err = 0; | |
1c92b4e5 | 1549 | unix_state_lock(sk); |
1da177e4 | 1550 | if (unix_peer(sk) == other) { |
e27dfcea | 1551 | unix_peer(sk) = NULL; |
1c92b4e5 | 1552 | unix_state_unlock(sk); |
1da177e4 LT |
1553 | |
1554 | unix_dgram_disconnected(sk, other); | |
1555 | sock_put(other); | |
1556 | err = -ECONNREFUSED; | |
1557 | } else { | |
1c92b4e5 | 1558 | unix_state_unlock(sk); |
1da177e4 LT |
1559 | } |
1560 | ||
1561 | other = NULL; | |
1562 | if (err) | |
1563 | goto out_free; | |
1564 | goto restart; | |
1565 | } | |
1566 | ||
1567 | err = -EPIPE; | |
1568 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1569 | goto out_unlock; | |
1570 | ||
1571 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1572 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1573 | if (err) | |
1574 | goto out_unlock; | |
1575 | } | |
1576 | ||
3c73419c | 1577 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1da177e4 LT |
1578 | if (!timeo) { |
1579 | err = -EAGAIN; | |
1580 | goto out_unlock; | |
1581 | } | |
1582 | ||
1583 | timeo = unix_wait_for_peer(other, timeo); | |
1584 | ||
1585 | err = sock_intr_errno(timeo); | |
1586 | if (signal_pending(current)) | |
1587 | goto out_free; | |
1588 | ||
1589 | goto restart; | |
1590 | } | |
1591 | ||
3f66116e AC |
1592 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
1593 | __net_timestamp(skb); | |
16e57262 | 1594 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1595 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1596 | if (max_level > unix_sk(other)->recursion_level) |
1597 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1598 | unix_state_unlock(other); |
676d2369 | 1599 | other->sk_data_ready(other); |
1da177e4 | 1600 | sock_put(other); |
7cc05662 | 1601 | scm_destroy(&scm); |
1da177e4 LT |
1602 | return len; |
1603 | ||
1604 | out_unlock: | |
1c92b4e5 | 1605 | unix_state_unlock(other); |
1da177e4 LT |
1606 | out_free: |
1607 | kfree_skb(skb); | |
1608 | out: | |
1609 | if (other) | |
1610 | sock_put(other); | |
7cc05662 | 1611 | scm_destroy(&scm); |
1da177e4 LT |
1612 | return err; |
1613 | } | |
1614 | ||
e370a723 ED |
1615 | /* We use paged skbs for stream sockets, and limit occupancy to 32768 |
1616 | * bytes, and a minimun of a full page. | |
1617 | */ | |
1618 | #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) | |
ac7bfa62 | 1619 | |
1b784140 YX |
1620 | static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, |
1621 | size_t len) | |
1da177e4 | 1622 | { |
1da177e4 LT |
1623 | struct sock *sk = sock->sk; |
1624 | struct sock *other = NULL; | |
6eba6a37 | 1625 | int err, size; |
f78a5fda | 1626 | struct sk_buff *skb; |
e27dfcea | 1627 | int sent = 0; |
7cc05662 | 1628 | struct scm_cookie scm; |
8ba69ba6 | 1629 | bool fds_sent = false; |
25888e30 | 1630 | int max_level; |
e370a723 | 1631 | int data_len; |
1da177e4 | 1632 | |
5f23b734 | 1633 | wait_for_unix_gc(); |
7cc05662 | 1634 | err = scm_send(sock, msg, &scm, false); |
1da177e4 LT |
1635 | if (err < 0) |
1636 | return err; | |
1637 | ||
1638 | err = -EOPNOTSUPP; | |
1639 | if (msg->msg_flags&MSG_OOB) | |
1640 | goto out_err; | |
1641 | ||
1642 | if (msg->msg_namelen) { | |
1643 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1644 | goto out_err; | |
1645 | } else { | |
1da177e4 | 1646 | err = -ENOTCONN; |
830a1e5c | 1647 | other = unix_peer(sk); |
1da177e4 LT |
1648 | if (!other) |
1649 | goto out_err; | |
1650 | } | |
1651 | ||
1652 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1653 | goto pipe_err; | |
1654 | ||
6eba6a37 | 1655 | while (sent < len) { |
e370a723 | 1656 | size = len - sent; |
1da177e4 LT |
1657 | |
1658 | /* Keep two messages in the pipe so it schedules better */ | |
e370a723 | 1659 | size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); |
1da177e4 | 1660 | |
e370a723 ED |
1661 | /* allow fallback to order-0 allocations */ |
1662 | size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); | |
ac7bfa62 | 1663 | |
e370a723 | 1664 | data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); |
1da177e4 | 1665 | |
31ff6aa5 KT |
1666 | data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); |
1667 | ||
e370a723 | 1668 | skb = sock_alloc_send_pskb(sk, size - data_len, data_len, |
28d64271 ED |
1669 | msg->msg_flags & MSG_DONTWAIT, &err, |
1670 | get_order(UNIX_SKB_FRAGS_SZ)); | |
e370a723 | 1671 | if (!skb) |
1da177e4 LT |
1672 | goto out_err; |
1673 | ||
f78a5fda | 1674 | /* Only send the fds in the first buffer */ |
7cc05662 | 1675 | err = unix_scm_to_skb(&scm, skb, !fds_sent); |
25888e30 | 1676 | if (err < 0) { |
7361c36c | 1677 | kfree_skb(skb); |
f78a5fda | 1678 | goto out_err; |
6209344f | 1679 | } |
25888e30 | 1680 | max_level = err + 1; |
7361c36c | 1681 | fds_sent = true; |
1da177e4 | 1682 | |
e370a723 ED |
1683 | skb_put(skb, size - data_len); |
1684 | skb->data_len = data_len; | |
1685 | skb->len = size; | |
c0371da6 | 1686 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); |
6eba6a37 | 1687 | if (err) { |
1da177e4 | 1688 | kfree_skb(skb); |
f78a5fda | 1689 | goto out_err; |
1da177e4 LT |
1690 | } |
1691 | ||
1c92b4e5 | 1692 | unix_state_lock(other); |
1da177e4 LT |
1693 | |
1694 | if (sock_flag(other, SOCK_DEAD) || | |
1695 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1696 | goto pipe_err_free; | |
1697 | ||
16e57262 | 1698 | maybe_add_creds(skb, sock, other); |
1da177e4 | 1699 | skb_queue_tail(&other->sk_receive_queue, skb); |
25888e30 ED |
1700 | if (max_level > unix_sk(other)->recursion_level) |
1701 | unix_sk(other)->recursion_level = max_level; | |
1c92b4e5 | 1702 | unix_state_unlock(other); |
676d2369 | 1703 | other->sk_data_ready(other); |
e27dfcea | 1704 | sent += size; |
1da177e4 | 1705 | } |
1da177e4 | 1706 | |
7cc05662 | 1707 | scm_destroy(&scm); |
1da177e4 LT |
1708 | |
1709 | return sent; | |
1710 | ||
1711 | pipe_err_free: | |
1c92b4e5 | 1712 | unix_state_unlock(other); |
1da177e4 LT |
1713 | kfree_skb(skb); |
1714 | pipe_err: | |
6eba6a37 ED |
1715 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1716 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
1717 | err = -EPIPE; |
1718 | out_err: | |
7cc05662 | 1719 | scm_destroy(&scm); |
1da177e4 LT |
1720 | return sent ? : err; |
1721 | } | |
1722 | ||
1b784140 YX |
1723 | static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg, |
1724 | size_t len) | |
1da177e4 LT |
1725 | { |
1726 | int err; | |
1727 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1728 | |
1da177e4 LT |
1729 | err = sock_error(sk); |
1730 | if (err) | |
1731 | return err; | |
1732 | ||
1733 | if (sk->sk_state != TCP_ESTABLISHED) | |
1734 | return -ENOTCONN; | |
1735 | ||
1736 | if (msg->msg_namelen) | |
1737 | msg->msg_namelen = 0; | |
1738 | ||
1b784140 | 1739 | return unix_dgram_sendmsg(sock, msg, len); |
1da177e4 | 1740 | } |
ac7bfa62 | 1741 | |
1b784140 YX |
1742 | static int unix_seqpacket_recvmsg(struct socket *sock, struct msghdr *msg, |
1743 | size_t size, int flags) | |
a05d2ad1 EB |
1744 | { |
1745 | struct sock *sk = sock->sk; | |
1746 | ||
1747 | if (sk->sk_state != TCP_ESTABLISHED) | |
1748 | return -ENOTCONN; | |
1749 | ||
1b784140 | 1750 | return unix_dgram_recvmsg(sock, msg, size, flags); |
a05d2ad1 EB |
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 | ||
1b784140 YX |
1763 | static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, |
1764 | size_t size, int flags) | |
1da177e4 | 1765 | { |
7cc05662 | 1766 | struct scm_cookie scm; |
1da177e4 LT |
1767 | struct sock *sk = sock->sk; |
1768 | struct unix_sock *u = unix_sk(sk); | |
1769 | int noblock = flags & MSG_DONTWAIT; | |
1770 | struct sk_buff *skb; | |
1771 | int err; | |
f55bb7f9 | 1772 | int peeked, skip; |
1da177e4 LT |
1773 | |
1774 | err = -EOPNOTSUPP; | |
1775 | if (flags&MSG_OOB) | |
1776 | goto out; | |
1777 | ||
b3ca9b02 | 1778 | err = mutex_lock_interruptible(&u->readlock); |
de144391 ED |
1779 | if (unlikely(err)) { |
1780 | /* recvmsg() in non blocking mode is supposed to return -EAGAIN | |
1781 | * sk_rcvtimeo is not honored by mutex_lock_interruptible() | |
1782 | */ | |
1783 | err = noblock ? -EAGAIN : -ERESTARTSYS; | |
b3ca9b02 RW |
1784 | goto out; |
1785 | } | |
1da177e4 | 1786 | |
f55bb7f9 PE |
1787 | skip = sk_peek_offset(sk, flags); |
1788 | ||
1789 | skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); | |
0a112258 FZ |
1790 | if (!skb) { |
1791 | unix_state_lock(sk); | |
1792 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
1793 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
1794 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1795 | err = 0; | |
1796 | unix_state_unlock(sk); | |
1da177e4 | 1797 | goto out_unlock; |
0a112258 | 1798 | } |
1da177e4 | 1799 | |
67426b75 ED |
1800 | wake_up_interruptible_sync_poll(&u->peer_wait, |
1801 | POLLOUT | POLLWRNORM | POLLWRBAND); | |
1da177e4 LT |
1802 | |
1803 | if (msg->msg_name) | |
1804 | unix_copy_addr(msg, skb->sk); | |
1805 | ||
f55bb7f9 PE |
1806 | if (size > skb->len - skip) |
1807 | size = skb->len - skip; | |
1808 | else if (size < skb->len - skip) | |
1da177e4 LT |
1809 | msg->msg_flags |= MSG_TRUNC; |
1810 | ||
51f3d02b | 1811 | err = skb_copy_datagram_msg(skb, skip, msg, size); |
1da177e4 LT |
1812 | if (err) |
1813 | goto out_free; | |
1814 | ||
3f66116e AC |
1815 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
1816 | __sock_recv_timestamp(msg, sk, skb); | |
1817 | ||
7cc05662 CH |
1818 | memset(&scm, 0, sizeof(scm)); |
1819 | ||
1820 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); | |
1821 | unix_set_secdata(&scm, skb); | |
1da177e4 | 1822 | |
6eba6a37 | 1823 | if (!(flags & MSG_PEEK)) { |
1da177e4 | 1824 | if (UNIXCB(skb).fp) |
7cc05662 | 1825 | unix_detach_fds(&scm, skb); |
f55bb7f9 PE |
1826 | |
1827 | sk_peek_offset_bwd(sk, skb->len); | |
6eba6a37 | 1828 | } else { |
1da177e4 LT |
1829 | /* It is questionable: on PEEK we could: |
1830 | - do not return fds - good, but too simple 8) | |
1831 | - return fds, and do not return them on read (old strategy, | |
1832 | apparently wrong) | |
1833 | - clone fds (I chose it for now, it is the most universal | |
1834 | solution) | |
ac7bfa62 YH |
1835 | |
1836 | POSIX 1003.1g does not actually define this clearly | |
1837 | at all. POSIX 1003.1g doesn't define a lot of things | |
1838 | clearly however! | |
1839 | ||
1da177e4 | 1840 | */ |
f55bb7f9 PE |
1841 | |
1842 | sk_peek_offset_fwd(sk, size); | |
1843 | ||
1da177e4 | 1844 | if (UNIXCB(skb).fp) |
7cc05662 | 1845 | scm.fp = scm_fp_dup(UNIXCB(skb).fp); |
1da177e4 | 1846 | } |
9f6f9af7 | 1847 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
1da177e4 | 1848 | |
7cc05662 | 1849 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
1850 | |
1851 | out_free: | |
6eba6a37 | 1852 | skb_free_datagram(sk, skb); |
1da177e4 | 1853 | out_unlock: |
57b47a53 | 1854 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1855 | out: |
1856 | return err; | |
1857 | } | |
1858 | ||
1859 | /* | |
79f632c7 | 1860 | * Sleep until more data has arrived. But check for races.. |
1da177e4 | 1861 | */ |
79f632c7 BP |
1862 | static long unix_stream_data_wait(struct sock *sk, long timeo, |
1863 | struct sk_buff *last) | |
1da177e4 LT |
1864 | { |
1865 | DEFINE_WAIT(wait); | |
1866 | ||
1c92b4e5 | 1867 | unix_state_lock(sk); |
1da177e4 LT |
1868 | |
1869 | for (;;) { | |
aa395145 | 1870 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
1da177e4 | 1871 | |
79f632c7 | 1872 | if (skb_peek_tail(&sk->sk_receive_queue) != last || |
1da177e4 LT |
1873 | sk->sk_err || |
1874 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1875 | signal_pending(current) || | |
1876 | !timeo) | |
1877 | break; | |
1878 | ||
1879 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1880 | unix_state_unlock(sk); |
2b15af6f | 1881 | timeo = freezable_schedule_timeout(timeo); |
1c92b4e5 | 1882 | unix_state_lock(sk); |
1da177e4 LT |
1883 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1884 | } | |
1885 | ||
aa395145 | 1886 | finish_wait(sk_sleep(sk), &wait); |
1c92b4e5 | 1887 | unix_state_unlock(sk); |
1da177e4 LT |
1888 | return timeo; |
1889 | } | |
1890 | ||
e370a723 ED |
1891 | static unsigned int unix_skb_len(const struct sk_buff *skb) |
1892 | { | |
1893 | return skb->len - UNIXCB(skb).consumed; | |
1894 | } | |
1895 | ||
1b784140 YX |
1896 | static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, |
1897 | size_t size, int flags) | |
1da177e4 | 1898 | { |
7cc05662 | 1899 | struct scm_cookie scm; |
1da177e4 LT |
1900 | struct sock *sk = sock->sk; |
1901 | struct unix_sock *u = unix_sk(sk); | |
342dfc30 | 1902 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); |
1da177e4 | 1903 | int copied = 0; |
de144391 | 1904 | int noblock = flags & MSG_DONTWAIT; |
1da177e4 LT |
1905 | int check_creds = 0; |
1906 | int target; | |
1907 | int err = 0; | |
1908 | long timeo; | |
fc0d7536 | 1909 | int skip; |
1da177e4 LT |
1910 | |
1911 | err = -EINVAL; | |
1912 | if (sk->sk_state != TCP_ESTABLISHED) | |
1913 | goto out; | |
1914 | ||
1915 | err = -EOPNOTSUPP; | |
1916 | if (flags&MSG_OOB) | |
1917 | goto out; | |
1918 | ||
1919 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
de144391 | 1920 | timeo = sock_rcvtimeo(sk, noblock); |
1da177e4 | 1921 | |
1da177e4 LT |
1922 | /* Lock the socket to prevent queue disordering |
1923 | * while sleeps in memcpy_tomsg | |
1924 | */ | |
1925 | ||
7cc05662 | 1926 | memset(&scm, 0, sizeof(scm)); |
1da177e4 | 1927 | |
b3ca9b02 | 1928 | err = mutex_lock_interruptible(&u->readlock); |
de144391 ED |
1929 | if (unlikely(err)) { |
1930 | /* recvmsg() in non blocking mode is supposed to return -EAGAIN | |
1931 | * sk_rcvtimeo is not honored by mutex_lock_interruptible() | |
1932 | */ | |
1933 | err = noblock ? -EAGAIN : -ERESTARTSYS; | |
b3ca9b02 RW |
1934 | goto out; |
1935 | } | |
1da177e4 | 1936 | |
6eba6a37 | 1937 | do { |
1da177e4 | 1938 | int chunk; |
79f632c7 | 1939 | struct sk_buff *skb, *last; |
1da177e4 | 1940 | |
3c0d2f37 | 1941 | unix_state_lock(sk); |
79f632c7 | 1942 | last = skb = skb_peek(&sk->sk_receive_queue); |
fc0d7536 | 1943 | again: |
6eba6a37 | 1944 | if (skb == NULL) { |
25888e30 | 1945 | unix_sk(sk)->recursion_level = 0; |
1da177e4 | 1946 | if (copied >= target) |
3c0d2f37 | 1947 | goto unlock; |
1da177e4 LT |
1948 | |
1949 | /* | |
1950 | * POSIX 1003.1g mandates this order. | |
1951 | */ | |
ac7bfa62 | 1952 | |
6eba6a37 ED |
1953 | err = sock_error(sk); |
1954 | if (err) | |
3c0d2f37 | 1955 | goto unlock; |
1da177e4 | 1956 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1957 | goto unlock; |
1958 | ||
1959 | unix_state_unlock(sk); | |
1da177e4 LT |
1960 | err = -EAGAIN; |
1961 | if (!timeo) | |
1962 | break; | |
57b47a53 | 1963 | mutex_unlock(&u->readlock); |
1da177e4 | 1964 | |
79f632c7 | 1965 | timeo = unix_stream_data_wait(sk, timeo, last); |
1da177e4 | 1966 | |
b3ca9b02 RW |
1967 | if (signal_pending(current) |
1968 | || mutex_lock_interruptible(&u->readlock)) { | |
1da177e4 LT |
1969 | err = sock_intr_errno(timeo); |
1970 | goto out; | |
1971 | } | |
b3ca9b02 | 1972 | |
1da177e4 | 1973 | continue; |
3c0d2f37 MS |
1974 | unlock: |
1975 | unix_state_unlock(sk); | |
1976 | break; | |
1da177e4 | 1977 | } |
fc0d7536 | 1978 | |
79f632c7 | 1979 | skip = sk_peek_offset(sk, flags); |
e370a723 ED |
1980 | while (skip >= unix_skb_len(skb)) { |
1981 | skip -= unix_skb_len(skb); | |
79f632c7 | 1982 | last = skb; |
fc0d7536 | 1983 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
79f632c7 BP |
1984 | if (!skb) |
1985 | goto again; | |
fc0d7536 PE |
1986 | } |
1987 | ||
3c0d2f37 | 1988 | unix_state_unlock(sk); |
1da177e4 LT |
1989 | |
1990 | if (check_creds) { | |
1991 | /* Never glue messages from different writers */ | |
7cc05662 CH |
1992 | if ((UNIXCB(skb).pid != scm.pid) || |
1993 | !uid_eq(UNIXCB(skb).uid, scm.creds.uid) || | |
1994 | !gid_eq(UNIXCB(skb).gid, scm.creds.gid)) | |
1da177e4 | 1995 | break; |
0e82e7f6 | 1996 | } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { |
1da177e4 | 1997 | /* Copy credentials */ |
7cc05662 | 1998 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
1da177e4 LT |
1999 | check_creds = 1; |
2000 | } | |
2001 | ||
2002 | /* Copy address just once */ | |
6eba6a37 | 2003 | if (sunaddr) { |
1da177e4 LT |
2004 | unix_copy_addr(msg, skb->sk); |
2005 | sunaddr = NULL; | |
2006 | } | |
2007 | ||
e370a723 | 2008 | chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size); |
51f3d02b DM |
2009 | if (skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip, |
2010 | msg, chunk)) { | |
1da177e4 LT |
2011 | if (copied == 0) |
2012 | copied = -EFAULT; | |
2013 | break; | |
2014 | } | |
2015 | copied += chunk; | |
2016 | size -= chunk; | |
2017 | ||
2018 | /* Mark read part of skb as used */ | |
6eba6a37 | 2019 | if (!(flags & MSG_PEEK)) { |
e370a723 | 2020 | UNIXCB(skb).consumed += chunk; |
1da177e4 | 2021 | |
fc0d7536 PE |
2022 | sk_peek_offset_bwd(sk, chunk); |
2023 | ||
1da177e4 | 2024 | if (UNIXCB(skb).fp) |
7cc05662 | 2025 | unix_detach_fds(&scm, skb); |
1da177e4 | 2026 | |
e370a723 | 2027 | if (unix_skb_len(skb)) |
1da177e4 | 2028 | break; |
1da177e4 | 2029 | |
6f01fd6e | 2030 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2031 | consume_skb(skb); |
1da177e4 | 2032 | |
7cc05662 | 2033 | if (scm.fp) |
1da177e4 | 2034 | break; |
6eba6a37 | 2035 | } else { |
1da177e4 LT |
2036 | /* It is questionable, see note in unix_dgram_recvmsg. |
2037 | */ | |
2038 | if (UNIXCB(skb).fp) | |
7cc05662 | 2039 | scm.fp = scm_fp_dup(UNIXCB(skb).fp); |
1da177e4 | 2040 | |
fc0d7536 PE |
2041 | sk_peek_offset_fwd(sk, chunk); |
2042 | ||
1da177e4 LT |
2043 | break; |
2044 | } | |
2045 | } while (size); | |
2046 | ||
57b47a53 | 2047 | mutex_unlock(&u->readlock); |
7cc05662 | 2048 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
2049 | out: |
2050 | return copied ? : err; | |
2051 | } | |
2052 | ||
2053 | static int unix_shutdown(struct socket *sock, int mode) | |
2054 | { | |
2055 | struct sock *sk = sock->sk; | |
2056 | struct sock *other; | |
2057 | ||
fc61b928 XW |
2058 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
2059 | return -EINVAL; | |
2060 | /* This maps: | |
2061 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2062 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2063 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2064 | */ | |
2065 | ++mode; | |
7180a031 AC |
2066 | |
2067 | unix_state_lock(sk); | |
2068 | sk->sk_shutdown |= mode; | |
2069 | other = unix_peer(sk); | |
2070 | if (other) | |
2071 | sock_hold(other); | |
2072 | unix_state_unlock(sk); | |
2073 | sk->sk_state_change(sk); | |
2074 | ||
2075 | if (other && | |
2076 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2077 | ||
2078 | int peer_mode = 0; | |
2079 | ||
2080 | if (mode&RCV_SHUTDOWN) | |
2081 | peer_mode |= SEND_SHUTDOWN; | |
2082 | if (mode&SEND_SHUTDOWN) | |
2083 | peer_mode |= RCV_SHUTDOWN; | |
2084 | unix_state_lock(other); | |
2085 | other->sk_shutdown |= peer_mode; | |
2086 | unix_state_unlock(other); | |
2087 | other->sk_state_change(other); | |
2088 | if (peer_mode == SHUTDOWN_MASK) | |
2089 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); | |
2090 | else if (peer_mode & RCV_SHUTDOWN) | |
2091 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); | |
1da177e4 | 2092 | } |
7180a031 AC |
2093 | if (other) |
2094 | sock_put(other); | |
2095 | ||
1da177e4 LT |
2096 | return 0; |
2097 | } | |
2098 | ||
885ee74d PE |
2099 | long unix_inq_len(struct sock *sk) |
2100 | { | |
2101 | struct sk_buff *skb; | |
2102 | long amount = 0; | |
2103 | ||
2104 | if (sk->sk_state == TCP_LISTEN) | |
2105 | return -EINVAL; | |
2106 | ||
2107 | spin_lock(&sk->sk_receive_queue.lock); | |
2108 | if (sk->sk_type == SOCK_STREAM || | |
2109 | sk->sk_type == SOCK_SEQPACKET) { | |
2110 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
e370a723 | 2111 | amount += unix_skb_len(skb); |
885ee74d PE |
2112 | } else { |
2113 | skb = skb_peek(&sk->sk_receive_queue); | |
2114 | if (skb) | |
2115 | amount = skb->len; | |
2116 | } | |
2117 | spin_unlock(&sk->sk_receive_queue.lock); | |
2118 | ||
2119 | return amount; | |
2120 | } | |
2121 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2122 | ||
2123 | long unix_outq_len(struct sock *sk) | |
2124 | { | |
2125 | return sk_wmem_alloc_get(sk); | |
2126 | } | |
2127 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2128 | ||
1da177e4 LT |
2129 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
2130 | { | |
2131 | struct sock *sk = sock->sk; | |
e27dfcea | 2132 | long amount = 0; |
1da177e4 LT |
2133 | int err; |
2134 | ||
6eba6a37 ED |
2135 | switch (cmd) { |
2136 | case SIOCOUTQ: | |
885ee74d | 2137 | amount = unix_outq_len(sk); |
6eba6a37 ED |
2138 | err = put_user(amount, (int __user *)arg); |
2139 | break; | |
2140 | case SIOCINQ: | |
885ee74d PE |
2141 | amount = unix_inq_len(sk); |
2142 | if (amount < 0) | |
2143 | err = amount; | |
2144 | else | |
1da177e4 | 2145 | err = put_user(amount, (int __user *)arg); |
885ee74d | 2146 | break; |
6eba6a37 ED |
2147 | default: |
2148 | err = -ENOIOCTLCMD; | |
2149 | break; | |
1da177e4 LT |
2150 | } |
2151 | return err; | |
2152 | } | |
2153 | ||
6eba6a37 | 2154 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
2155 | { |
2156 | struct sock *sk = sock->sk; | |
2157 | unsigned int mask; | |
2158 | ||
aa395145 | 2159 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
2160 | mask = 0; |
2161 | ||
2162 | /* exceptional events? */ | |
2163 | if (sk->sk_err) | |
2164 | mask |= POLLERR; | |
2165 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
2166 | mask |= POLLHUP; | |
f348d70a | 2167 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 2168 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
2169 | |
2170 | /* readable? */ | |
db40980f | 2171 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
2172 | mask |= POLLIN | POLLRDNORM; |
2173 | ||
2174 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
2175 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2176 | sk->sk_state == TCP_CLOSE) | |
1da177e4 LT |
2177 | mask |= POLLHUP; |
2178 | ||
2179 | /* | |
2180 | * we set writable also when the other side has shut down the | |
2181 | * connection. This prevents stuck sockets. | |
2182 | */ | |
2183 | if (unix_writable(sk)) | |
2184 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
2185 | ||
2186 | return mask; | |
2187 | } | |
2188 | ||
ec0d215f RW |
2189 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2190 | poll_table *wait) | |
3c73419c | 2191 | { |
ec0d215f RW |
2192 | struct sock *sk = sock->sk, *other; |
2193 | unsigned int mask, writable; | |
3c73419c | 2194 | |
aa395145 | 2195 | sock_poll_wait(file, sk_sleep(sk), wait); |
3c73419c RW |
2196 | mask = 0; |
2197 | ||
2198 | /* exceptional events? */ | |
2199 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
7d4c04fc | 2200 | mask |= POLLERR | |
8facd5fb | 2201 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0); |
7d4c04fc | 2202 | |
3c73419c | 2203 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
5456f09a | 2204 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
3c73419c RW |
2205 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2206 | mask |= POLLHUP; | |
2207 | ||
2208 | /* readable? */ | |
5456f09a | 2209 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
3c73419c RW |
2210 | mask |= POLLIN | POLLRDNORM; |
2211 | ||
2212 | /* Connection-based need to check for termination and startup */ | |
2213 | if (sk->sk_type == SOCK_SEQPACKET) { | |
2214 | if (sk->sk_state == TCP_CLOSE) | |
2215 | mask |= POLLHUP; | |
2216 | /* connection hasn't started yet? */ | |
2217 | if (sk->sk_state == TCP_SYN_SENT) | |
2218 | return mask; | |
2219 | } | |
2220 | ||
973a34aa | 2221 | /* No write status requested, avoid expensive OUT tests. */ |
626cf236 | 2222 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
973a34aa ED |
2223 | return mask; |
2224 | ||
ec0d215f | 2225 | writable = unix_writable(sk); |
5456f09a ED |
2226 | other = unix_peer_get(sk); |
2227 | if (other) { | |
2228 | if (unix_peer(other) != sk) { | |
2229 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); | |
2230 | if (unix_recvq_full(other)) | |
2231 | writable = 0; | |
ec0d215f | 2232 | } |
5456f09a | 2233 | sock_put(other); |
ec0d215f RW |
2234 | } |
2235 | ||
2236 | if (writable) | |
3c73419c RW |
2237 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2238 | else | |
2239 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
2240 | ||
3c73419c RW |
2241 | return mask; |
2242 | } | |
1da177e4 LT |
2243 | |
2244 | #ifdef CONFIG_PROC_FS | |
a53eb3fe | 2245 | |
7123aaa3 ED |
2246 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
2247 | ||
2248 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
2249 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) | |
2250 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) | |
a53eb3fe | 2251 | |
7123aaa3 | 2252 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
1da177e4 | 2253 | { |
7123aaa3 ED |
2254 | unsigned long offset = get_offset(*pos); |
2255 | unsigned long bucket = get_bucket(*pos); | |
2256 | struct sock *sk; | |
2257 | unsigned long count = 0; | |
1da177e4 | 2258 | |
7123aaa3 ED |
2259 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { |
2260 | if (sock_net(sk) != seq_file_net(seq)) | |
097e66c5 | 2261 | continue; |
7123aaa3 ED |
2262 | if (++count == offset) |
2263 | break; | |
2264 | } | |
2265 | ||
2266 | return sk; | |
2267 | } | |
2268 | ||
2269 | static struct sock *unix_next_socket(struct seq_file *seq, | |
2270 | struct sock *sk, | |
2271 | loff_t *pos) | |
2272 | { | |
2273 | unsigned long bucket; | |
2274 | ||
2275 | while (sk > (struct sock *)SEQ_START_TOKEN) { | |
2276 | sk = sk_next(sk); | |
2277 | if (!sk) | |
2278 | goto next_bucket; | |
2279 | if (sock_net(sk) == seq_file_net(seq)) | |
2280 | return sk; | |
1da177e4 | 2281 | } |
7123aaa3 ED |
2282 | |
2283 | do { | |
2284 | sk = unix_from_bucket(seq, pos); | |
2285 | if (sk) | |
2286 | return sk; | |
2287 | ||
2288 | next_bucket: | |
2289 | bucket = get_bucket(*pos) + 1; | |
2290 | *pos = set_bucket_offset(bucket, 1); | |
2291 | } while (bucket < ARRAY_SIZE(unix_socket_table)); | |
2292 | ||
1da177e4 LT |
2293 | return NULL; |
2294 | } | |
2295 | ||
1da177e4 | 2296 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
9a429c49 | 2297 | __acquires(unix_table_lock) |
1da177e4 | 2298 | { |
fbe9cc4a | 2299 | spin_lock(&unix_table_lock); |
7123aaa3 ED |
2300 | |
2301 | if (!*pos) | |
2302 | return SEQ_START_TOKEN; | |
2303 | ||
2304 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) | |
2305 | return NULL; | |
2306 | ||
2307 | return unix_next_socket(seq, NULL, pos); | |
1da177e4 LT |
2308 | } |
2309 | ||
2310 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2311 | { | |
2312 | ++*pos; | |
7123aaa3 | 2313 | return unix_next_socket(seq, v, pos); |
1da177e4 LT |
2314 | } |
2315 | ||
2316 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2317 | __releases(unix_table_lock) |
1da177e4 | 2318 | { |
fbe9cc4a | 2319 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2320 | } |
2321 | ||
2322 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2323 | { | |
ac7bfa62 | 2324 | |
b9f3124f | 2325 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
2326 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2327 | "Inode Path\n"); | |
2328 | else { | |
2329 | struct sock *s = v; | |
2330 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2331 | unix_state_lock(s); |
1da177e4 | 2332 | |
71338aa7 | 2333 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 LT |
2334 | s, |
2335 | atomic_read(&s->sk_refcnt), | |
2336 | 0, | |
2337 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2338 | s->sk_type, | |
2339 | s->sk_socket ? | |
2340 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2341 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2342 | sock_i_ino(s)); | |
2343 | ||
2344 | if (u->addr) { | |
2345 | int i, len; | |
2346 | seq_putc(seq, ' '); | |
2347 | ||
2348 | i = 0; | |
2349 | len = u->addr->len - sizeof(short); | |
2350 | if (!UNIX_ABSTRACT(s)) | |
2351 | len--; | |
2352 | else { | |
2353 | seq_putc(seq, '@'); | |
2354 | i++; | |
2355 | } | |
2356 | for ( ; i < len; i++) | |
2357 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2358 | } | |
1c92b4e5 | 2359 | unix_state_unlock(s); |
1da177e4 LT |
2360 | seq_putc(seq, '\n'); |
2361 | } | |
2362 | ||
2363 | return 0; | |
2364 | } | |
2365 | ||
56b3d975 | 2366 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2367 | .start = unix_seq_start, |
2368 | .next = unix_seq_next, | |
2369 | .stop = unix_seq_stop, | |
2370 | .show = unix_seq_show, | |
2371 | }; | |
2372 | ||
1da177e4 LT |
2373 | static int unix_seq_open(struct inode *inode, struct file *file) |
2374 | { | |
e372c414 | 2375 | return seq_open_net(inode, file, &unix_seq_ops, |
8b51b064 | 2376 | sizeof(struct seq_net_private)); |
1da177e4 LT |
2377 | } |
2378 | ||
da7071d7 | 2379 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2380 | .owner = THIS_MODULE, |
2381 | .open = unix_seq_open, | |
2382 | .read = seq_read, | |
2383 | .llseek = seq_lseek, | |
e372c414 | 2384 | .release = seq_release_net, |
1da177e4 LT |
2385 | }; |
2386 | ||
2387 | #endif | |
2388 | ||
ec1b4cf7 | 2389 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
2390 | .family = PF_UNIX, |
2391 | .create = unix_create, | |
2392 | .owner = THIS_MODULE, | |
2393 | }; | |
2394 | ||
097e66c5 | 2395 | |
2c8c1e72 | 2396 | static int __net_init unix_net_init(struct net *net) |
097e66c5 DL |
2397 | { |
2398 | int error = -ENOMEM; | |
2399 | ||
a0a53c8b | 2400 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
2401 | if (unix_sysctl_register(net)) |
2402 | goto out; | |
d392e497 | 2403 | |
097e66c5 | 2404 | #ifdef CONFIG_PROC_FS |
d4beaa66 | 2405 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { |
1597fbc0 | 2406 | unix_sysctl_unregister(net); |
097e66c5 | 2407 | goto out; |
1597fbc0 | 2408 | } |
097e66c5 DL |
2409 | #endif |
2410 | error = 0; | |
2411 | out: | |
48dcc33e | 2412 | return error; |
097e66c5 DL |
2413 | } |
2414 | ||
2c8c1e72 | 2415 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 2416 | { |
1597fbc0 | 2417 | unix_sysctl_unregister(net); |
ece31ffd | 2418 | remove_proc_entry("unix", net->proc_net); |
097e66c5 DL |
2419 | } |
2420 | ||
2421 | static struct pernet_operations unix_net_ops = { | |
2422 | .init = unix_net_init, | |
2423 | .exit = unix_net_exit, | |
2424 | }; | |
2425 | ||
1da177e4 LT |
2426 | static int __init af_unix_init(void) |
2427 | { | |
2428 | int rc = -1; | |
1da177e4 | 2429 | |
b4fff5f8 | 2430 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 LT |
2431 | |
2432 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 | 2433 | if (rc != 0) { |
5cc208be | 2434 | pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); |
1da177e4 LT |
2435 | goto out; |
2436 | } | |
2437 | ||
2438 | sock_register(&unix_family_ops); | |
097e66c5 | 2439 | register_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2440 | out: |
2441 | return rc; | |
2442 | } | |
2443 | ||
2444 | static void __exit af_unix_exit(void) | |
2445 | { | |
2446 | sock_unregister(PF_UNIX); | |
1da177e4 | 2447 | proto_unregister(&unix_proto); |
097e66c5 | 2448 | unregister_pernet_subsys(&unix_net_ops); |
1da177e4 LT |
2449 | } |
2450 | ||
3d366960 DW |
2451 | /* Earlier than device_initcall() so that other drivers invoking |
2452 | request_module() don't end up in a loop when modprobe tries | |
2453 | to use a UNIX socket. But later than subsys_initcall() because | |
2454 | we depend on stuff initialised there */ | |
2455 | fs_initcall(af_unix_init); | |
1da177e4 LT |
2456 | module_exit(af_unix_exit); |
2457 | ||
2458 | MODULE_LICENSE("GPL"); | |
2459 | MODULE_ALIAS_NETPROTO(PF_UNIX); |