Root/
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 | { |
626 | if (protocol && protocol != PF_UNIX) |
627 | return -EPROTONOSUPPORT; |
628 | |
629 | sock->state = SS_UNCONNECTED; |
630 | |
631 | switch (sock->type) { |
632 | case SOCK_STREAM: |
633 | sock->ops = &unix_stream_ops; |
634 | break; |
635 | /* |
636 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though |
637 | * nothing uses it. |
638 | */ |
639 | case SOCK_RAW: |
640 | sock->type = SOCK_DGRAM; |
641 | case SOCK_DGRAM: |
642 | sock->ops = &unix_dgram_ops; |
643 | break; |
644 | case SOCK_SEQPACKET: |
645 | sock->ops = &unix_seqpacket_ops; |
646 | break; |
647 | default: |
648 | return -ESOCKTNOSUPPORT; |
649 | } |
650 | |
651 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
652 | } |
653 | |
654 | static int unix_release(struct socket *sock) |
655 | { |
656 | struct sock *sk = sock->sk; |
657 | |
658 | if (!sk) |
659 | return 0; |
660 | |
661 | sock->sk = NULL; |
662 | |
663 | return unix_release_sock(sk, 0); |
664 | } |
665 | |
666 | static int unix_autobind(struct socket *sock) |
667 | { |
668 | struct sock *sk = sock->sk; |
669 | struct net *net = sock_net(sk); |
670 | struct unix_sock *u = unix_sk(sk); |
671 | static u32 ordernum = 1; |
672 | struct unix_address *addr; |
673 | int err; |
674 | |
675 | mutex_lock(&u->readlock); |
676 | |
677 | err = 0; |
678 | if (u->addr) |
679 | goto out; |
680 | |
681 | err = -ENOMEM; |
682 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
683 | if (!addr) |
684 | goto out; |
685 | |
686 | addr->name->sun_family = AF_UNIX; |
687 | atomic_set(&addr->refcnt, 1); |
688 | |
689 | retry: |
690 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); |
691 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
692 | |
693 | spin_lock(&unix_table_lock); |
694 | ordernum = (ordernum+1)&0xFFFFF; |
695 | |
696 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
697 | addr->hash)) { |
698 | spin_unlock(&unix_table_lock); |
699 | /* Sanity yield. It is unusual case, but yet... */ |
700 | if (!(ordernum&0xFF)) |
701 | yield(); |
702 | goto retry; |
703 | } |
704 | addr->hash ^= sk->sk_type; |
705 | |
706 | __unix_remove_socket(sk); |
707 | u->addr = addr; |
708 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); |
709 | spin_unlock(&unix_table_lock); |
710 | err = 0; |
711 | |
712 | out: mutex_unlock(&u->readlock); |
713 | return err; |
714 | } |
715 | |
716 | static struct sock *unix_find_other(struct net *net, |
717 | struct sockaddr_un *sunname, int len, |
718 | int type, unsigned hash, int *error) |
719 | { |
720 | struct sock *u; |
721 | struct path path; |
722 | int err = 0; |
723 | |
724 | if (sunname->sun_path[0]) { |
725 | struct inode *inode; |
726 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); |
727 | if (err) |
728 | goto fail; |
729 | inode = path.dentry->d_inode; |
730 | err = inode_permission(inode, MAY_WRITE); |
731 | if (err) |
732 | goto put_fail; |
733 | |
734 | err = -ECONNREFUSED; |
735 | if (!S_ISSOCK(inode->i_mode)) |
736 | goto put_fail; |
737 | u = unix_find_socket_byinode(net, inode); |
738 | if (!u) |
739 | goto put_fail; |
740 | |
741 | if (u->sk_type == type) |
742 | touch_atime(path.mnt, path.dentry); |
743 | |
744 | path_put(&path); |
745 | |
746 | err = -EPROTOTYPE; |
747 | if (u->sk_type != type) { |
748 | sock_put(u); |
749 | goto fail; |
750 | } |
751 | } else { |
752 | err = -ECONNREFUSED; |
753 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
754 | if (u) { |
755 | struct dentry *dentry; |
756 | dentry = unix_sk(u)->dentry; |
757 | if (dentry) |
758 | touch_atime(unix_sk(u)->mnt, dentry); |
759 | } else |
760 | goto fail; |
761 | } |
762 | return u; |
763 | |
764 | put_fail: |
765 | path_put(&path); |
766 | fail: |
767 | *error = err; |
768 | return NULL; |
769 | } |
770 | |
771 | |
772 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
773 | { |
774 | struct sock *sk = sock->sk; |
775 | struct net *net = sock_net(sk); |
776 | struct unix_sock *u = unix_sk(sk); |
777 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
778 | struct dentry *dentry = NULL; |
779 | struct nameidata nd; |
780 | int err; |
781 | unsigned hash; |
782 | struct unix_address *addr; |
783 | struct hlist_head *list; |
784 | |
785 | err = -EINVAL; |
786 | if (sunaddr->sun_family != AF_UNIX) |
787 | goto out; |
788 | |
789 | if (addr_len == sizeof(short)) { |
790 | err = unix_autobind(sock); |
791 | goto out; |
792 | } |
793 | |
794 | err = unix_mkname(sunaddr, addr_len, &hash); |
795 | if (err < 0) |
796 | goto out; |
797 | addr_len = err; |
798 | |
799 | mutex_lock(&u->readlock); |
800 | |
801 | err = -EINVAL; |
802 | if (u->addr) |
803 | goto out_up; |
804 | |
805 | err = -ENOMEM; |
806 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); |
807 | if (!addr) |
808 | goto out_up; |
809 | |
810 | memcpy(addr->name, sunaddr, addr_len); |
811 | addr->len = addr_len; |
812 | addr->hash = hash ^ sk->sk_type; |
813 | atomic_set(&addr->refcnt, 1); |
814 | |
815 | if (sunaddr->sun_path[0]) { |
816 | unsigned int mode; |
817 | err = 0; |
818 | /* |
819 | * Get the parent directory, calculate the hash for last |
820 | * component. |
821 | */ |
822 | err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); |
823 | if (err) |
824 | goto out_mknod_parent; |
825 | |
826 | dentry = lookup_create(&nd, 0); |
827 | err = PTR_ERR(dentry); |
828 | if (IS_ERR(dentry)) |
829 | goto out_mknod_unlock; |
830 | |
831 | /* |
832 | * All right, let's create it. |
833 | */ |
834 | mode = S_IFSOCK | |
835 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
836 | err = mnt_want_write(nd.path.mnt); |
837 | if (err) |
838 | goto out_mknod_dput; |
839 | err = security_path_mknod(&nd.path, dentry, mode, 0); |
840 | if (err) |
841 | goto out_mknod_drop_write; |
842 | err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); |
843 | out_mknod_drop_write: |
844 | mnt_drop_write(nd.path.mnt); |
845 | if (err) |
846 | goto out_mknod_dput; |
847 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
848 | dput(nd.path.dentry); |
849 | nd.path.dentry = dentry; |
850 | |
851 | addr->hash = UNIX_HASH_SIZE; |
852 | } |
853 | |
854 | spin_lock(&unix_table_lock); |
855 | |
856 | if (!sunaddr->sun_path[0]) { |
857 | err = -EADDRINUSE; |
858 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
859 | sk->sk_type, hash)) { |
860 | unix_release_addr(addr); |
861 | goto out_unlock; |
862 | } |
863 | |
864 | list = &unix_socket_table[addr->hash]; |
865 | } else { |
866 | list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; |
867 | u->dentry = nd.path.dentry; |
868 | u->mnt = nd.path.mnt; |
869 | } |
870 | |
871 | err = 0; |
872 | __unix_remove_socket(sk); |
873 | u->addr = addr; |
874 | __unix_insert_socket(list, sk); |
875 | |
876 | out_unlock: |
877 | spin_unlock(&unix_table_lock); |
878 | out_up: |
879 | mutex_unlock(&u->readlock); |
880 | out: |
881 | return err; |
882 | |
883 | out_mknod_dput: |
884 | dput(dentry); |
885 | out_mknod_unlock: |
886 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
887 | path_put(&nd.path); |
888 | out_mknod_parent: |
889 | if (err == -EEXIST) |
890 | err = -EADDRINUSE; |
891 | unix_release_addr(addr); |
892 | goto out_up; |
893 | } |
894 | |
895 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
896 | { |
897 | if (unlikely(sk1 == sk2) || !sk2) { |
898 | unix_state_lock(sk1); |
899 | return; |
900 | } |
901 | if (sk1 < sk2) { |
902 | unix_state_lock(sk1); |
903 | unix_state_lock_nested(sk2); |
904 | } else { |
905 | unix_state_lock(sk2); |
906 | unix_state_lock_nested(sk1); |
907 | } |
908 | } |
909 | |
910 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) |
911 | { |
912 | if (unlikely(sk1 == sk2) || !sk2) { |
913 | unix_state_unlock(sk1); |
914 | return; |
915 | } |
916 | unix_state_unlock(sk1); |
917 | unix_state_unlock(sk2); |
918 | } |
919 | |
920 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
921 | int alen, int flags) |
922 | { |
923 | struct sock *sk = sock->sk; |
924 | struct net *net = sock_net(sk); |
925 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
926 | struct sock *other; |
927 | unsigned hash; |
928 | int err; |
929 | |
930 | if (addr->sa_family != AF_UNSPEC) { |
931 | err = unix_mkname(sunaddr, alen, &hash); |
932 | if (err < 0) |
933 | goto out; |
934 | alen = err; |
935 | |
936 | if (test_bit(SOCK_PASSCRED, &sock->flags) && |
937 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) |
938 | goto out; |
939 | |
940 | restart: |
941 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
942 | if (!other) |
943 | goto out; |
944 | |
945 | unix_state_double_lock(sk, other); |
946 | |
947 | /* Apparently VFS overslept socket death. Retry. */ |
948 | if (sock_flag(other, SOCK_DEAD)) { |
949 | unix_state_double_unlock(sk, other); |
950 | sock_put(other); |
951 | goto restart; |
952 | } |
953 | |
954 | err = -EPERM; |
955 | if (!unix_may_send(sk, other)) |
956 | goto out_unlock; |
957 | |
958 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
959 | if (err) |
960 | goto out_unlock; |
961 | |
962 | } else { |
963 | /* |
964 | * 1003.1g breaking connected state with AF_UNSPEC |
965 | */ |
966 | other = NULL; |
967 | unix_state_double_lock(sk, other); |
968 | } |
969 | |
970 | /* |
971 | * If it was connected, reconnect. |
972 | */ |
973 | if (unix_peer(sk)) { |
974 | struct sock *old_peer = unix_peer(sk); |
975 | unix_peer(sk) = other; |
976 | unix_state_double_unlock(sk, other); |
977 | |
978 | if (other != old_peer) |
979 | unix_dgram_disconnected(sk, old_peer); |
980 | sock_put(old_peer); |
981 | } else { |
982 | unix_peer(sk) = other; |
983 | unix_state_double_unlock(sk, other); |
984 | } |
985 | return 0; |
986 | |
987 | out_unlock: |
988 | unix_state_double_unlock(sk, other); |
989 | sock_put(other); |
990 | out: |
991 | return err; |
992 | } |
993 | |
994 | static long unix_wait_for_peer(struct sock *other, long timeo) |
995 | { |
996 | struct unix_sock *u = unix_sk(other); |
997 | int sched; |
998 | DEFINE_WAIT(wait); |
999 | |
1000 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); |
1001 | |
1002 | sched = !sock_flag(other, SOCK_DEAD) && |
1003 | !(other->sk_shutdown & RCV_SHUTDOWN) && |
1004 | unix_recvq_full(other); |
1005 | |
1006 | unix_state_unlock(other); |
1007 | |
1008 | if (sched) |
1009 | timeo = schedule_timeout(timeo); |
1010 | |
1011 | finish_wait(&u->peer_wait, &wait); |
1012 | return timeo; |
1013 | } |
1014 | |
1015 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, |
1016 | int addr_len, int flags) |
1017 | { |
1018 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1019 | struct sock *sk = sock->sk; |
1020 | struct net *net = sock_net(sk); |
1021 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
1022 | struct sock *newsk = NULL; |
1023 | struct sock *other = NULL; |
1024 | struct sk_buff *skb = NULL; |
1025 | unsigned hash; |
1026 | int st; |
1027 | int err; |
1028 | long timeo; |
1029 | |
1030 | err = unix_mkname(sunaddr, addr_len, &hash); |
1031 | if (err < 0) |
1032 | goto out; |
1033 | addr_len = err; |
1034 | |
1035 | if (test_bit(SOCK_PASSCRED, &sock->flags) |
1036 | && !u->addr && (err = unix_autobind(sock)) != 0) |
1037 | goto out; |
1038 | |
1039 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); |
1040 | |
1041 | /* First of all allocate resources. |
1042 | If we will make it after state is locked, |
1043 | we will have to recheck all again in any case. |
1044 | */ |
1045 | |
1046 | err = -ENOMEM; |
1047 | |
1048 | /* create new sock for complete connection */ |
1049 | newsk = unix_create1(sock_net(sk), NULL); |
1050 | if (newsk == NULL) |
1051 | goto out; |
1052 | |
1053 | /* Allocate skb for sending to listening sock */ |
1054 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); |
1055 | if (skb == NULL) |
1056 | goto out; |
1057 | |
1058 | restart: |
1059 | /* Find listening sock. */ |
1060 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
1061 | if (!other) |
1062 | goto out; |
1063 | |
1064 | /* Latch state of peer */ |
1065 | unix_state_lock(other); |
1066 | |
1067 | /* Apparently VFS overslept socket death. Retry. */ |
1068 | if (sock_flag(other, SOCK_DEAD)) { |
1069 | unix_state_unlock(other); |
1070 | sock_put(other); |
1071 | goto restart; |
1072 | } |
1073 | |
1074 | err = -ECONNREFUSED; |
1075 | if (other->sk_state != TCP_LISTEN) |
1076 | goto out_unlock; |
1077 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1078 | goto out_unlock; |
1079 | |
1080 | if (unix_recvq_full(other)) { |
1081 | err = -EAGAIN; |
1082 | if (!timeo) |
1083 | goto out_unlock; |
1084 | |
1085 | timeo = unix_wait_for_peer(other, timeo); |
1086 | |
1087 | err = sock_intr_errno(timeo); |
1088 | if (signal_pending(current)) |
1089 | goto out; |
1090 | sock_put(other); |
1091 | goto restart; |
1092 | } |
1093 | |
1094 | /* Latch our state. |
1095 | |
1096 | It is tricky place. We need to grab write lock and cannot |
1097 | drop lock on peer. It is dangerous because deadlock is |
1098 | possible. Connect to self case and simultaneous |
1099 | attempt to connect are eliminated by checking socket |
1100 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we |
1101 | check this before attempt to grab lock. |
1102 | |
1103 | Well, and we have to recheck the state after socket locked. |
1104 | */ |
1105 | st = sk->sk_state; |
1106 | |
1107 | switch (st) { |
1108 | case TCP_CLOSE: |
1109 | /* This is ok... continue with connect */ |
1110 | break; |
1111 | case TCP_ESTABLISHED: |
1112 | /* Socket is already connected */ |
1113 | err = -EISCONN; |
1114 | goto out_unlock; |
1115 | default: |
1116 | err = -EINVAL; |
1117 | goto out_unlock; |
1118 | } |
1119 | |
1120 | unix_state_lock_nested(sk); |
1121 | |
1122 | if (sk->sk_state != st) { |
1123 | unix_state_unlock(sk); |
1124 | unix_state_unlock(other); |
1125 | sock_put(other); |
1126 | goto restart; |
1127 | } |
1128 | |
1129 | err = security_unix_stream_connect(sock, other->sk_socket, newsk); |
1130 | if (err) { |
1131 | unix_state_unlock(sk); |
1132 | goto out_unlock; |
1133 | } |
1134 | |
1135 | /* The way is open! Fastly set all the necessary fields... */ |
1136 | |
1137 | sock_hold(sk); |
1138 | unix_peer(newsk) = sk; |
1139 | newsk->sk_state = TCP_ESTABLISHED; |
1140 | newsk->sk_type = sk->sk_type; |
1141 | newsk->sk_peercred.pid = task_tgid_vnr(current); |
1142 | current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid); |
1143 | newu = unix_sk(newsk); |
1144 | newsk->sk_sleep = &newu->peer_wait; |
1145 | otheru = unix_sk(other); |
1146 | |
1147 | /* copy address information from listening to new sock*/ |
1148 | if (otheru->addr) { |
1149 | atomic_inc(&otheru->addr->refcnt); |
1150 | newu->addr = otheru->addr; |
1151 | } |
1152 | if (otheru->dentry) { |
1153 | newu->dentry = dget(otheru->dentry); |
1154 | newu->mnt = mntget(otheru->mnt); |
1155 | } |
1156 | |
1157 | /* Set credentials */ |
1158 | sk->sk_peercred = other->sk_peercred; |
1159 | |
1160 | sock->state = SS_CONNECTED; |
1161 | sk->sk_state = TCP_ESTABLISHED; |
1162 | sock_hold(newsk); |
1163 | |
1164 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ |
1165 | unix_peer(sk) = newsk; |
1166 | |
1167 | unix_state_unlock(sk); |
1168 | |
1169 | /* take ten and and send info to listening sock */ |
1170 | spin_lock(&other->sk_receive_queue.lock); |
1171 | __skb_queue_tail(&other->sk_receive_queue, skb); |
1172 | spin_unlock(&other->sk_receive_queue.lock); |
1173 | unix_state_unlock(other); |
1174 | other->sk_data_ready(other, 0); |
1175 | sock_put(other); |
1176 | return 0; |
1177 | |
1178 | out_unlock: |
1179 | if (other) |
1180 | unix_state_unlock(other); |
1181 | |
1182 | out: |
1183 | kfree_skb(skb); |
1184 | if (newsk) |
1185 | unix_release_sock(newsk, 0); |
1186 | if (other) |
1187 | sock_put(other); |
1188 | return err; |
1189 | } |
1190 | |
1191 | static int unix_socketpair(struct socket *socka, struct socket *sockb) |
1192 | { |
1193 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1194 | |
1195 | /* Join our sockets back to back */ |
1196 | sock_hold(ska); |
1197 | sock_hold(skb); |
1198 | unix_peer(ska) = skb; |
1199 | unix_peer(skb) = ska; |
1200 | ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current); |
1201 | current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid); |
1202 | ska->sk_peercred.uid = skb->sk_peercred.uid; |
1203 | ska->sk_peercred.gid = skb->sk_peercred.gid; |
1204 | |
1205 | if (ska->sk_type != SOCK_DGRAM) { |
1206 | ska->sk_state = TCP_ESTABLISHED; |
1207 | skb->sk_state = TCP_ESTABLISHED; |
1208 | socka->state = SS_CONNECTED; |
1209 | sockb->state = SS_CONNECTED; |
1210 | } |
1211 | return 0; |
1212 | } |
1213 | |
1214 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
1215 | { |
1216 | struct sock *sk = sock->sk; |
1217 | struct sock *tsk; |
1218 | struct sk_buff *skb; |
1219 | int err; |
1220 | |
1221 | err = -EOPNOTSUPP; |
1222 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1223 | goto out; |
1224 | |
1225 | err = -EINVAL; |
1226 | if (sk->sk_state != TCP_LISTEN) |
1227 | goto out; |
1228 | |
1229 | /* If socket state is TCP_LISTEN it cannot change (for now...), |
1230 | * so that no locks are necessary. |
1231 | */ |
1232 | |
1233 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); |
1234 | if (!skb) { |
1235 | /* This means receive shutdown. */ |
1236 | if (err == 0) |
1237 | err = -EINVAL; |
1238 | goto out; |
1239 | } |
1240 | |
1241 | tsk = skb->sk; |
1242 | skb_free_datagram(sk, skb); |
1243 | wake_up_interruptible(&unix_sk(sk)->peer_wait); |
1244 | |
1245 | /* attach accepted sock to socket */ |
1246 | unix_state_lock(tsk); |
1247 | newsock->state = SS_CONNECTED; |
1248 | sock_graft(tsk, newsock); |
1249 | unix_state_unlock(tsk); |
1250 | return 0; |
1251 | |
1252 | out: |
1253 | return err; |
1254 | } |
1255 | |
1256 | |
1257 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) |
1258 | { |
1259 | struct sock *sk = sock->sk; |
1260 | struct unix_sock *u; |
1261 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
1262 | int err = 0; |
1263 | |
1264 | if (peer) { |
1265 | sk = unix_peer_get(sk); |
1266 | |
1267 | err = -ENOTCONN; |
1268 | if (!sk) |
1269 | goto out; |
1270 | err = 0; |
1271 | } else { |
1272 | sock_hold(sk); |
1273 | } |
1274 | |
1275 | u = unix_sk(sk); |
1276 | unix_state_lock(sk); |
1277 | if (!u->addr) { |
1278 | sunaddr->sun_family = AF_UNIX; |
1279 | sunaddr->sun_path[0] = 0; |
1280 | *uaddr_len = sizeof(short); |
1281 | } else { |
1282 | struct unix_address *addr = u->addr; |
1283 | |
1284 | *uaddr_len = addr->len; |
1285 | memcpy(sunaddr, addr->name, *uaddr_len); |
1286 | } |
1287 | unix_state_unlock(sk); |
1288 | sock_put(sk); |
1289 | out: |
1290 | return err; |
1291 | } |
1292 | |
1293 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1294 | { |
1295 | int i; |
1296 | |
1297 | scm->fp = UNIXCB(skb).fp; |
1298 | skb->destructor = sock_wfree; |
1299 | UNIXCB(skb).fp = NULL; |
1300 | |
1301 | for (i = scm->fp->count-1; i >= 0; i--) |
1302 | unix_notinflight(scm->fp->fp[i]); |
1303 | } |
1304 | |
1305 | static void unix_destruct_fds(struct sk_buff *skb) |
1306 | { |
1307 | struct scm_cookie scm; |
1308 | memset(&scm, 0, sizeof(scm)); |
1309 | unix_detach_fds(&scm, skb); |
1310 | |
1311 | /* Alas, it calls VFS */ |
1312 | /* So fscking what? fput() had been SMP-safe since the last Summer */ |
1313 | scm_destroy(&scm); |
1314 | sock_wfree(skb); |
1315 | } |
1316 | |
1317 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1318 | { |
1319 | int i; |
1320 | |
1321 | /* |
1322 | * Need to duplicate file references for the sake of garbage |
1323 | * collection. Otherwise a socket in the fps might become a |
1324 | * candidate for GC while the skb is not yet queued. |
1325 | */ |
1326 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); |
1327 | if (!UNIXCB(skb).fp) |
1328 | return -ENOMEM; |
1329 | |
1330 | for (i = scm->fp->count-1; i >= 0; i--) |
1331 | unix_inflight(scm->fp->fp[i]); |
1332 | skb->destructor = unix_destruct_fds; |
1333 | return 0; |
1334 | } |
1335 | |
1336 | /* |
1337 | * Send AF_UNIX data. |
1338 | */ |
1339 | |
1340 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1341 | struct msghdr *msg, size_t len) |
1342 | { |
1343 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
1344 | struct sock *sk = sock->sk; |
1345 | struct net *net = sock_net(sk); |
1346 | struct unix_sock *u = unix_sk(sk); |
1347 | struct sockaddr_un *sunaddr = msg->msg_name; |
1348 | struct sock *other = NULL; |
1349 | int namelen = 0; /* fake GCC */ |
1350 | int err; |
1351 | unsigned hash; |
1352 | struct sk_buff *skb; |
1353 | long timeo; |
1354 | struct scm_cookie tmp_scm; |
1355 | |
1356 | if (NULL == siocb->scm) |
1357 | siocb->scm = &tmp_scm; |
1358 | wait_for_unix_gc(); |
1359 | err = scm_send(sock, msg, siocb->scm); |
1360 | if (err < 0) |
1361 | return err; |
1362 | |
1363 | err = -EOPNOTSUPP; |
1364 | if (msg->msg_flags&MSG_OOB) |
1365 | goto out; |
1366 | |
1367 | if (msg->msg_namelen) { |
1368 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); |
1369 | if (err < 0) |
1370 | goto out; |
1371 | namelen = err; |
1372 | } else { |
1373 | sunaddr = NULL; |
1374 | err = -ENOTCONN; |
1375 | other = unix_peer_get(sk); |
1376 | if (!other) |
1377 | goto out; |
1378 | } |
1379 | |
1380 | if (test_bit(SOCK_PASSCRED, &sock->flags) |
1381 | && !u->addr && (err = unix_autobind(sock)) != 0) |
1382 | goto out; |
1383 | |
1384 | err = -EMSGSIZE; |
1385 | if (len > sk->sk_sndbuf - 32) |
1386 | goto out; |
1387 | |
1388 | skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); |
1389 | if (skb == NULL) |
1390 | goto out; |
1391 | |
1392 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1393 | if (siocb->scm->fp) { |
1394 | err = unix_attach_fds(siocb->scm, skb); |
1395 | if (err) |
1396 | goto out_free; |
1397 | } |
1398 | unix_get_secdata(siocb->scm, skb); |
1399 | |
1400 | skb_reset_transport_header(skb); |
1401 | err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); |
1402 | if (err) |
1403 | goto out_free; |
1404 | |
1405 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
1406 | |
1407 | restart: |
1408 | if (!other) { |
1409 | err = -ECONNRESET; |
1410 | if (sunaddr == NULL) |
1411 | goto out_free; |
1412 | |
1413 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
1414 | hash, &err); |
1415 | if (other == NULL) |
1416 | goto out_free; |
1417 | } |
1418 | |
1419 | unix_state_lock(other); |
1420 | err = -EPERM; |
1421 | if (!unix_may_send(sk, other)) |
1422 | goto out_unlock; |
1423 | |
1424 | if (sock_flag(other, SOCK_DEAD)) { |
1425 | /* |
1426 | * Check with 1003.1g - what should |
1427 | * datagram error |
1428 | */ |
1429 | unix_state_unlock(other); |
1430 | sock_put(other); |
1431 | |
1432 | err = 0; |
1433 | unix_state_lock(sk); |
1434 | if (unix_peer(sk) == other) { |
1435 | unix_peer(sk) = NULL; |
1436 | unix_state_unlock(sk); |
1437 | |
1438 | unix_dgram_disconnected(sk, other); |
1439 | sock_put(other); |
1440 | err = -ECONNREFUSED; |
1441 | } else { |
1442 | unix_state_unlock(sk); |
1443 | } |
1444 | |
1445 | other = NULL; |
1446 | if (err) |
1447 | goto out_free; |
1448 | goto restart; |
1449 | } |
1450 | |
1451 | err = -EPIPE; |
1452 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1453 | goto out_unlock; |
1454 | |
1455 | if (sk->sk_type != SOCK_SEQPACKET) { |
1456 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
1457 | if (err) |
1458 | goto out_unlock; |
1459 | } |
1460 | |
1461 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
1462 | if (!timeo) { |
1463 | err = -EAGAIN; |
1464 | goto out_unlock; |
1465 | } |
1466 | |
1467 | timeo = unix_wait_for_peer(other, timeo); |
1468 | |
1469 | err = sock_intr_errno(timeo); |
1470 | if (signal_pending(current)) |
1471 | goto out_free; |
1472 | |
1473 | goto restart; |
1474 | } |
1475 | |
1476 | skb_queue_tail(&other->sk_receive_queue, skb); |
1477 | unix_state_unlock(other); |
1478 | other->sk_data_ready(other, len); |
1479 | sock_put(other); |
1480 | scm_destroy(siocb->scm); |
1481 | return len; |
1482 | |
1483 | out_unlock: |
1484 | unix_state_unlock(other); |
1485 | out_free: |
1486 | kfree_skb(skb); |
1487 | out: |
1488 | if (other) |
1489 | sock_put(other); |
1490 | scm_destroy(siocb->scm); |
1491 | return err; |
1492 | } |
1493 | |
1494 | |
1495 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1496 | struct msghdr *msg, size_t len) |
1497 | { |
1498 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
1499 | struct sock *sk = sock->sk; |
1500 | struct sock *other = NULL; |
1501 | struct sockaddr_un *sunaddr = msg->msg_name; |
1502 | int err, size; |
1503 | struct sk_buff *skb; |
1504 | int sent = 0; |
1505 | struct scm_cookie tmp_scm; |
1506 | bool fds_sent = false; |
1507 | |
1508 | if (NULL == siocb->scm) |
1509 | siocb->scm = &tmp_scm; |
1510 | wait_for_unix_gc(); |
1511 | err = scm_send(sock, msg, siocb->scm); |
1512 | if (err < 0) |
1513 | return err; |
1514 | |
1515 | err = -EOPNOTSUPP; |
1516 | if (msg->msg_flags&MSG_OOB) |
1517 | goto out_err; |
1518 | |
1519 | if (msg->msg_namelen) { |
1520 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; |
1521 | goto out_err; |
1522 | } else { |
1523 | sunaddr = NULL; |
1524 | err = -ENOTCONN; |
1525 | other = unix_peer(sk); |
1526 | if (!other) |
1527 | goto out_err; |
1528 | } |
1529 | |
1530 | if (sk->sk_shutdown & SEND_SHUTDOWN) |
1531 | goto pipe_err; |
1532 | |
1533 | while (sent < len) { |
1534 | /* |
1535 | * Optimisation for the fact that under 0.01% of X |
1536 | * messages typically need breaking up. |
1537 | */ |
1538 | |
1539 | size = len-sent; |
1540 | |
1541 | /* Keep two messages in the pipe so it schedules better */ |
1542 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
1543 | size = (sk->sk_sndbuf >> 1) - 64; |
1544 | |
1545 | if (size > SKB_MAX_ALLOC) |
1546 | size = SKB_MAX_ALLOC; |
1547 | |
1548 | /* |
1549 | * Grab a buffer |
1550 | */ |
1551 | |
1552 | skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, |
1553 | &err); |
1554 | |
1555 | if (skb == NULL) |
1556 | goto out_err; |
1557 | |
1558 | /* |
1559 | * If you pass two values to the sock_alloc_send_skb |
1560 | * it tries to grab the large buffer with GFP_NOFS |
1561 | * (which can fail easily), and if it fails grab the |
1562 | * fallback size buffer which is under a page and will |
1563 | * succeed. [Alan] |
1564 | */ |
1565 | size = min_t(int, size, skb_tailroom(skb)); |
1566 | |
1567 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1568 | /* Only send the fds in the first buffer */ |
1569 | if (siocb->scm->fp && !fds_sent) { |
1570 | err = unix_attach_fds(siocb->scm, skb); |
1571 | if (err) { |
1572 | kfree_skb(skb); |
1573 | goto out_err; |
1574 | } |
1575 | fds_sent = true; |
1576 | } |
1577 | |
1578 | err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
1579 | if (err) { |
1580 | kfree_skb(skb); |
1581 | goto out_err; |
1582 | } |
1583 | |
1584 | unix_state_lock(other); |
1585 | |
1586 | if (sock_flag(other, SOCK_DEAD) || |
1587 | (other->sk_shutdown & RCV_SHUTDOWN)) |
1588 | goto pipe_err_free; |
1589 | |
1590 | skb_queue_tail(&other->sk_receive_queue, skb); |
1591 | unix_state_unlock(other); |
1592 | other->sk_data_ready(other, size); |
1593 | sent += size; |
1594 | } |
1595 | |
1596 | scm_destroy(siocb->scm); |
1597 | siocb->scm = NULL; |
1598 | |
1599 | return sent; |
1600 | |
1601 | pipe_err_free: |
1602 | unix_state_unlock(other); |
1603 | kfree_skb(skb); |
1604 | pipe_err: |
1605 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
1606 | send_sig(SIGPIPE, current, 0); |
1607 | err = -EPIPE; |
1608 | out_err: |
1609 | scm_destroy(siocb->scm); |
1610 | siocb->scm = NULL; |
1611 | return sent ? : err; |
1612 | } |
1613 | |
1614 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1615 | struct msghdr *msg, size_t len) |
1616 | { |
1617 | int err; |
1618 | struct sock *sk = sock->sk; |
1619 | |
1620 | err = sock_error(sk); |
1621 | if (err) |
1622 | return err; |
1623 | |
1624 | if (sk->sk_state != TCP_ESTABLISHED) |
1625 | return -ENOTCONN; |
1626 | |
1627 | if (msg->msg_namelen) |
1628 | msg->msg_namelen = 0; |
1629 | |
1630 | return unix_dgram_sendmsg(kiocb, sock, msg, len); |
1631 | } |
1632 | |
1633 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1634 | { |
1635 | struct unix_sock *u = unix_sk(sk); |
1636 | |
1637 | msg->msg_namelen = 0; |
1638 | if (u->addr) { |
1639 | msg->msg_namelen = u->addr->len; |
1640 | memcpy(msg->msg_name, u->addr->name, u->addr->len); |
1641 | } |
1642 | } |
1643 | |
1644 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, |
1645 | struct msghdr *msg, size_t size, |
1646 | int flags) |
1647 | { |
1648 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
1649 | struct scm_cookie tmp_scm; |
1650 | struct sock *sk = sock->sk; |
1651 | struct unix_sock *u = unix_sk(sk); |
1652 | int noblock = flags & MSG_DONTWAIT; |
1653 | struct sk_buff *skb; |
1654 | int err; |
1655 | |
1656 | err = -EOPNOTSUPP; |
1657 | if (flags&MSG_OOB) |
1658 | goto out; |
1659 | |
1660 | msg->msg_namelen = 0; |
1661 | |
1662 | mutex_lock(&u->readlock); |
1663 | |
1664 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1665 | if (!skb) { |
1666 | unix_state_lock(sk); |
1667 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ |
1668 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && |
1669 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
1670 | err = 0; |
1671 | unix_state_unlock(sk); |
1672 | goto out_unlock; |
1673 | } |
1674 | |
1675 | wake_up_interruptible_sync(&u->peer_wait); |
1676 | |
1677 | if (msg->msg_name) |
1678 | unix_copy_addr(msg, skb->sk); |
1679 | |
1680 | if (size > skb->len) |
1681 | size = skb->len; |
1682 | else if (size < skb->len) |
1683 | msg->msg_flags |= MSG_TRUNC; |
1684 | |
1685 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); |
1686 | if (err) |
1687 | goto out_free; |
1688 | |
1689 | if (!siocb->scm) { |
1690 | siocb->scm = &tmp_scm; |
1691 | memset(&tmp_scm, 0, sizeof(tmp_scm)); |
1692 | } |
1693 | siocb->scm->creds = *UNIXCREDS(skb); |
1694 | unix_set_secdata(siocb->scm, skb); |
1695 | |
1696 | if (!(flags & MSG_PEEK)) { |
1697 | if (UNIXCB(skb).fp) |
1698 | unix_detach_fds(siocb->scm, skb); |
1699 | } else { |
1700 | /* It is questionable: on PEEK we could: |
1701 | - do not return fds - good, but too simple 8) |
1702 | - return fds, and do not return them on read (old strategy, |
1703 | apparently wrong) |
1704 | - clone fds (I chose it for now, it is the most universal |
1705 | solution) |
1706 | |
1707 | POSIX 1003.1g does not actually define this clearly |
1708 | at all. POSIX 1003.1g doesn't define a lot of things |
1709 | clearly however! |
1710 | |
1711 | */ |
1712 | if (UNIXCB(skb).fp) |
1713 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
1714 | } |
1715 | err = size; |
1716 | |
1717 | scm_recv(sock, msg, siocb->scm, flags); |
1718 | |
1719 | out_free: |
1720 | skb_free_datagram(sk, skb); |
1721 | out_unlock: |
1722 | mutex_unlock(&u->readlock); |
1723 | out: |
1724 | return err; |
1725 | } |
1726 | |
1727 | /* |
1728 | * Sleep until data has arrive. But check for races.. |
1729 | */ |
1730 | |
1731 | static long unix_stream_data_wait(struct sock *sk, long timeo) |
1732 | { |
1733 | DEFINE_WAIT(wait); |
1734 | |
1735 | unix_state_lock(sk); |
1736 | |
1737 | for (;;) { |
1738 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); |
1739 | |
1740 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
1741 | sk->sk_err || |
1742 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
1743 | signal_pending(current) || |
1744 | !timeo) |
1745 | break; |
1746 | |
1747 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1748 | unix_state_unlock(sk); |
1749 | timeo = schedule_timeout(timeo); |
1750 | unix_state_lock(sk); |
1751 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1752 | } |
1753 | |
1754 | finish_wait(sk->sk_sleep, &wait); |
1755 | unix_state_unlock(sk); |
1756 | return timeo; |
1757 | } |
1758 | |
1759 | |
1760 | |
1761 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
1762 | struct msghdr *msg, size_t size, |
1763 | int flags) |
1764 | { |
1765 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
1766 | struct scm_cookie tmp_scm; |
1767 | struct sock *sk = sock->sk; |
1768 | struct unix_sock *u = unix_sk(sk); |
1769 | struct sockaddr_un *sunaddr = msg->msg_name; |
1770 | int copied = 0; |
1771 | int check_creds = 0; |
1772 | int target; |
1773 | int err = 0; |
1774 | long timeo; |
1775 | |
1776 | err = -EINVAL; |
1777 | if (sk->sk_state != TCP_ESTABLISHED) |
1778 | goto out; |
1779 | |
1780 | err = -EOPNOTSUPP; |
1781 | if (flags&MSG_OOB) |
1782 | goto out; |
1783 | |
1784 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); |
1785 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); |
1786 | |
1787 | msg->msg_namelen = 0; |
1788 | |
1789 | /* Lock the socket to prevent queue disordering |
1790 | * while sleeps in memcpy_tomsg |
1791 | */ |
1792 | |
1793 | if (!siocb->scm) { |
1794 | siocb->scm = &tmp_scm; |
1795 | memset(&tmp_scm, 0, sizeof(tmp_scm)); |
1796 | } |
1797 | |
1798 | mutex_lock(&u->readlock); |
1799 | |
1800 | do { |
1801 | int chunk; |
1802 | struct sk_buff *skb; |
1803 | |
1804 | unix_state_lock(sk); |
1805 | skb = skb_dequeue(&sk->sk_receive_queue); |
1806 | if (skb == NULL) { |
1807 | if (copied >= target) |
1808 | goto unlock; |
1809 | |
1810 | /* |
1811 | * POSIX 1003.1g mandates this order. |
1812 | */ |
1813 | |
1814 | err = sock_error(sk); |
1815 | if (err) |
1816 | goto unlock; |
1817 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
1818 | goto unlock; |
1819 | |
1820 | unix_state_unlock(sk); |
1821 | err = -EAGAIN; |
1822 | if (!timeo) |
1823 | break; |
1824 | mutex_unlock(&u->readlock); |
1825 | |
1826 | timeo = unix_stream_data_wait(sk, timeo); |
1827 | |
1828 | if (signal_pending(current)) { |
1829 | err = sock_intr_errno(timeo); |
1830 | goto out; |
1831 | } |
1832 | mutex_lock(&u->readlock); |
1833 | continue; |
1834 | unlock: |
1835 | unix_state_unlock(sk); |
1836 | break; |
1837 | } |
1838 | unix_state_unlock(sk); |
1839 | |
1840 | if (check_creds) { |
1841 | /* Never glue messages from different writers */ |
1842 | if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, |
1843 | sizeof(siocb->scm->creds)) != 0) { |
1844 | skb_queue_head(&sk->sk_receive_queue, skb); |
1845 | break; |
1846 | } |
1847 | } else { |
1848 | /* Copy credentials */ |
1849 | siocb->scm->creds = *UNIXCREDS(skb); |
1850 | check_creds = 1; |
1851 | } |
1852 | |
1853 | /* Copy address just once */ |
1854 | if (sunaddr) { |
1855 | unix_copy_addr(msg, skb->sk); |
1856 | sunaddr = NULL; |
1857 | } |
1858 | |
1859 | chunk = min_t(unsigned int, skb->len, size); |
1860 | if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { |
1861 | skb_queue_head(&sk->sk_receive_queue, skb); |
1862 | if (copied == 0) |
1863 | copied = -EFAULT; |
1864 | break; |
1865 | } |
1866 | copied += chunk; |
1867 | size -= chunk; |
1868 | |
1869 | /* Mark read part of skb as used */ |
1870 | if (!(flags & MSG_PEEK)) { |
1871 | skb_pull(skb, chunk); |
1872 | |
1873 | if (UNIXCB(skb).fp) |
1874 | unix_detach_fds(siocb->scm, skb); |
1875 | |
1876 | /* put the skb back if we didn't use it up.. */ |
1877 | if (skb->len) { |
1878 | skb_queue_head(&sk->sk_receive_queue, skb); |
1879 | break; |
1880 | } |
1881 | |
1882 | kfree_skb(skb); |
1883 | |
1884 | if (siocb->scm->fp) |
1885 | break; |
1886 | } else { |
1887 | /* It is questionable, see note in unix_dgram_recvmsg. |
1888 | */ |
1889 | if (UNIXCB(skb).fp) |
1890 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
1891 | |
1892 | /* put message back and return */ |
1893 | skb_queue_head(&sk->sk_receive_queue, skb); |
1894 | break; |
1895 | } |
1896 | } while (size); |
1897 | |
1898 | mutex_unlock(&u->readlock); |
1899 | scm_recv(sock, msg, siocb->scm, flags); |
1900 | out: |
1901 | return copied ? : err; |
1902 | } |
1903 | |
1904 | static int unix_shutdown(struct socket *sock, int mode) |
1905 | { |
1906 | struct sock *sk = sock->sk; |
1907 | struct sock *other; |
1908 | |
1909 | mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); |
1910 | |
1911 | if (mode) { |
1912 | unix_state_lock(sk); |
1913 | sk->sk_shutdown |= mode; |
1914 | other = unix_peer(sk); |
1915 | if (other) |
1916 | sock_hold(other); |
1917 | unix_state_unlock(sk); |
1918 | sk->sk_state_change(sk); |
1919 | |
1920 | if (other && |
1921 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { |
1922 | |
1923 | int peer_mode = 0; |
1924 | |
1925 | if (mode&RCV_SHUTDOWN) |
1926 | peer_mode |= SEND_SHUTDOWN; |
1927 | if (mode&SEND_SHUTDOWN) |
1928 | peer_mode |= RCV_SHUTDOWN; |
1929 | unix_state_lock(other); |
1930 | other->sk_shutdown |= peer_mode; |
1931 | unix_state_unlock(other); |
1932 | other->sk_state_change(other); |
1933 | read_lock(&other->sk_callback_lock); |
1934 | if (peer_mode == SHUTDOWN_MASK) |
1935 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); |
1936 | else if (peer_mode & RCV_SHUTDOWN) |
1937 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); |
1938 | read_unlock(&other->sk_callback_lock); |
1939 | } |
1940 | if (other) |
1941 | sock_put(other); |
1942 | } |
1943 | return 0; |
1944 | } |
1945 | |
1946 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
1947 | { |
1948 | struct sock *sk = sock->sk; |
1949 | long amount = 0; |
1950 | int err; |
1951 | |
1952 | switch (cmd) { |
1953 | case SIOCOUTQ: |
1954 | amount = sk_wmem_alloc_get(sk); |
1955 | err = put_user(amount, (int __user *)arg); |
1956 | break; |
1957 | case SIOCINQ: |
1958 | { |
1959 | struct sk_buff *skb; |
1960 | |
1961 | if (sk->sk_state == TCP_LISTEN) { |
1962 | err = -EINVAL; |
1963 | break; |
1964 | } |
1965 | |
1966 | spin_lock(&sk->sk_receive_queue.lock); |
1967 | if (sk->sk_type == SOCK_STREAM || |
1968 | sk->sk_type == SOCK_SEQPACKET) { |
1969 | skb_queue_walk(&sk->sk_receive_queue, skb) |
1970 | amount += skb->len; |
1971 | } else { |
1972 | skb = skb_peek(&sk->sk_receive_queue); |
1973 | if (skb) |
1974 | amount = skb->len; |
1975 | } |
1976 | spin_unlock(&sk->sk_receive_queue.lock); |
1977 | err = put_user(amount, (int __user *)arg); |
1978 | break; |
1979 | } |
1980 | |
1981 | default: |
1982 | err = -ENOIOCTLCMD; |
1983 | break; |
1984 | } |
1985 | return err; |
1986 | } |
1987 | |
1988 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1989 | { |
1990 | struct sock *sk = sock->sk; |
1991 | unsigned int mask; |
1992 | |
1993 | sock_poll_wait(file, sk->sk_sleep, wait); |
1994 | mask = 0; |
1995 | |
1996 | /* exceptional events? */ |
1997 | if (sk->sk_err) |
1998 | mask |= POLLERR; |
1999 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2000 | mask |= POLLHUP; |
2001 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
2002 | mask |= POLLRDHUP; |
2003 | |
2004 | /* readable? */ |
2005 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
2006 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
2007 | mask |= POLLIN | POLLRDNORM; |
2008 | |
2009 | /* Connection-based need to check for termination and startup */ |
2010 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
2011 | sk->sk_state == TCP_CLOSE) |
2012 | mask |= POLLHUP; |
2013 | |
2014 | /* |
2015 | * we set writable also when the other side has shut down the |
2016 | * connection. This prevents stuck sockets. |
2017 | */ |
2018 | if (unix_writable(sk)) |
2019 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2020 | |
2021 | return mask; |
2022 | } |
2023 | |
2024 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
2025 | poll_table *wait) |
2026 | { |
2027 | struct sock *sk = sock->sk, *other; |
2028 | unsigned int mask, writable; |
2029 | |
2030 | sock_poll_wait(file, sk->sk_sleep, wait); |
2031 | mask = 0; |
2032 | |
2033 | /* exceptional events? */ |
2034 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
2035 | mask |= POLLERR; |
2036 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
2037 | mask |= POLLRDHUP; |
2038 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
2039 | mask |= POLLHUP; |
2040 | |
2041 | /* readable? */ |
2042 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
2043 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
2044 | mask |= POLLIN | POLLRDNORM; |
2045 | |
2046 | /* Connection-based need to check for termination and startup */ |
2047 | if (sk->sk_type == SOCK_SEQPACKET) { |
2048 | if (sk->sk_state == TCP_CLOSE) |
2049 | mask |= POLLHUP; |
2050 | /* connection hasn't started yet? */ |
2051 | if (sk->sk_state == TCP_SYN_SENT) |
2052 | return mask; |
2053 | } |
2054 | |
2055 | /* writable? */ |
2056 | writable = unix_writable(sk); |
2057 | if (writable) { |
2058 | other = unix_peer_get(sk); |
2059 | if (other) { |
2060 | if (unix_peer(other) != sk) { |
2061 | sock_poll_wait(file, &unix_sk(other)->peer_wait, |
2062 | wait); |
2063 | if (unix_recvq_full(other)) |
2064 | writable = 0; |
2065 | } |
2066 | |
2067 | sock_put(other); |
2068 | } |
2069 | } |
2070 | |
2071 | if (writable) |
2072 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
2073 | else |
2074 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); |
2075 | |
2076 | return mask; |
2077 | } |
2078 | |
2079 | #ifdef CONFIG_PROC_FS |
2080 | static struct sock *first_unix_socket(int *i) |
2081 | { |
2082 | for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { |
2083 | if (!hlist_empty(&unix_socket_table[*i])) |
2084 | return __sk_head(&unix_socket_table[*i]); |
2085 | } |
2086 | return NULL; |
2087 | } |
2088 | |
2089 | static struct sock *next_unix_socket(int *i, struct sock *s) |
2090 | { |
2091 | struct sock *next = sk_next(s); |
2092 | /* More in this chain? */ |
2093 | if (next) |
2094 | return next; |
2095 | /* Look for next non-empty chain. */ |
2096 | for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { |
2097 | if (!hlist_empty(&unix_socket_table[*i])) |
2098 | return __sk_head(&unix_socket_table[*i]); |
2099 | } |
2100 | return NULL; |
2101 | } |
2102 | |
2103 | struct unix_iter_state { |
2104 | struct seq_net_private p; |
2105 | int i; |
2106 | }; |
2107 | |
2108 | static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) |
2109 | { |
2110 | struct unix_iter_state *iter = seq->private; |
2111 | loff_t off = 0; |
2112 | struct sock *s; |
2113 | |
2114 | for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { |
2115 | if (sock_net(s) != seq_file_net(seq)) |
2116 | continue; |
2117 | if (off == pos) |
2118 | return s; |
2119 | ++off; |
2120 | } |
2121 | return NULL; |
2122 | } |
2123 | |
2124 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
2125 | __acquires(unix_table_lock) |
2126 | { |
2127 | spin_lock(&unix_table_lock); |
2128 | return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; |
2129 | } |
2130 | |
2131 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
2132 | { |
2133 | struct unix_iter_state *iter = seq->private; |
2134 | struct sock *sk = v; |
2135 | ++*pos; |
2136 | |
2137 | if (v == SEQ_START_TOKEN) |
2138 | sk = first_unix_socket(&iter->i); |
2139 | else |
2140 | sk = next_unix_socket(&iter->i, sk); |
2141 | while (sk && (sock_net(sk) != seq_file_net(seq))) |
2142 | sk = next_unix_socket(&iter->i, sk); |
2143 | return sk; |
2144 | } |
2145 | |
2146 | static void unix_seq_stop(struct seq_file *seq, void *v) |
2147 | __releases(unix_table_lock) |
2148 | { |
2149 | spin_unlock(&unix_table_lock); |
2150 | } |
2151 | |
2152 | static int unix_seq_show(struct seq_file *seq, void *v) |
2153 | { |
2154 | |
2155 | if (v == SEQ_START_TOKEN) |
2156 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
2157 | "Inode Path\n"); |
2158 | else { |
2159 | struct sock *s = v; |
2160 | struct unix_sock *u = unix_sk(s); |
2161 | unix_state_lock(s); |
2162 | |
2163 | seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", |
2164 | s, |
2165 | atomic_read(&s->sk_refcnt), |
2166 | 0, |
2167 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, |
2168 | s->sk_type, |
2169 | s->sk_socket ? |
2170 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : |
2171 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), |
2172 | sock_i_ino(s)); |
2173 | |
2174 | if (u->addr) { |
2175 | int i, len; |
2176 | seq_putc(seq, ' '); |
2177 | |
2178 | i = 0; |
2179 | len = u->addr->len - sizeof(short); |
2180 | if (!UNIX_ABSTRACT(s)) |
2181 | len--; |
2182 | else { |
2183 | seq_putc(seq, '@'); |
2184 | i++; |
2185 | } |
2186 | for ( ; i < len; i++) |
2187 | seq_putc(seq, u->addr->name->sun_path[i]); |
2188 | } |
2189 | unix_state_unlock(s); |
2190 | seq_putc(seq, '\n'); |
2191 | } |
2192 | |
2193 | return 0; |
2194 | } |
2195 | |
2196 | static const struct seq_operations unix_seq_ops = { |
2197 | .start = unix_seq_start, |
2198 | .next = unix_seq_next, |
2199 | .stop = unix_seq_stop, |
2200 | .show = unix_seq_show, |
2201 | }; |
2202 | |
2203 | static int unix_seq_open(struct inode *inode, struct file *file) |
2204 | { |
2205 | return seq_open_net(inode, file, &unix_seq_ops, |
2206 | sizeof(struct unix_iter_state)); |
2207 | } |
2208 | |
2209 | static const struct file_operations unix_seq_fops = { |
2210 | .owner = THIS_MODULE, |
2211 | .open = unix_seq_open, |
2212 | .read = seq_read, |
2213 | .llseek = seq_lseek, |
2214 | .release = seq_release_net, |
2215 | }; |
2216 | |
2217 | #endif |
2218 | |
2219 | static struct net_proto_family unix_family_ops = { |
2220 | .family = PF_UNIX, |
2221 | .create = unix_create, |
2222 | .owner = THIS_MODULE, |
2223 | }; |
2224 | |
2225 | |
2226 | static int unix_net_init(struct net *net) |
2227 | { |
2228 | int error = -ENOMEM; |
2229 | |
2230 | net->unx.sysctl_max_dgram_qlen = 10; |
2231 | if (unix_sysctl_register(net)) |
2232 | goto out; |
2233 | |
2234 | #ifdef CONFIG_PROC_FS |
2235 | if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { |
2236 | unix_sysctl_unregister(net); |
2237 | goto out; |
2238 | } |
2239 | #endif |
2240 | error = 0; |
2241 | out: |
2242 | return error; |
2243 | } |
2244 | |
2245 | static void unix_net_exit(struct net *net) |
2246 | { |
2247 | unix_sysctl_unregister(net); |
2248 | proc_net_remove(net, "unix"); |
2249 | } |
2250 | |
2251 | static struct pernet_operations unix_net_ops = { |
2252 | .init = unix_net_init, |
2253 | .exit = unix_net_exit, |
2254 | }; |
2255 | |
2256 | static int __init af_unix_init(void) |
2257 | { |
2258 | int rc = -1; |
2259 | struct sk_buff *dummy_skb; |
2260 | |
2261 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); |
2262 | |
2263 | rc = proto_register(&unix_proto, 1); |
2264 | if (rc != 0) { |
2265 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", |
2266 | __func__); |
2267 | goto out; |
2268 | } |
2269 | |
2270 | sock_register(&unix_family_ops); |
2271 | register_pernet_subsys(&unix_net_ops); |
2272 | out: |
2273 | return rc; |
2274 | } |
2275 | |
2276 | static void __exit af_unix_exit(void) |
2277 | { |
2278 | sock_unregister(PF_UNIX); |
2279 | proto_unregister(&unix_proto); |
2280 | unregister_pernet_subsys(&unix_net_ops); |
2281 | } |
2282 | |
2283 | /* Earlier than device_initcall() so that other drivers invoking |
2284 | request_module() don't end up in a loop when modprobe tries |
2285 | to use a UNIX socket. But later than subsys_initcall() because |
2286 | we depend on stuff initialised there */ |
2287 | fs_initcall(af_unix_init); |
2288 | module_exit(af_unix_exit); |
2289 | |
2290 | MODULE_LICENSE("GPL"); |
2291 | MODULE_ALIAS_NETPROTO(PF_UNIX); |
2292 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9