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