Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NET4: Implementation of BSD Unix domain sockets. | |
3 | * | |
4 | * Authors: Alan Cox, <alan.cox@linux.org> | |
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 | * Version: $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $ | |
12 | * | |
13 | * Fixes: | |
14 | * Linus Torvalds : Assorted bug cures. | |
15 | * Niibe Yutaka : async I/O support. | |
16 | * Carsten Paeth : PF_UNIX check, address fixes. | |
17 | * Alan Cox : Limit size of allocated blocks. | |
18 | * Alan Cox : Fixed the stupid socketpair bug. | |
19 | * Alan Cox : BSD compatibility fine tuning. | |
20 | * Alan Cox : Fixed a bug in connect when interrupted. | |
21 | * Alan Cox : Sorted out a proper draft version of | |
22 | * file descriptor passing hacked up from | |
23 | * Mike Shaver's work. | |
24 | * Marty Leisner : Fixes to fd passing | |
25 | * Nick Nevin : recvmsg bugfix. | |
26 | * Alan Cox : Started proper garbage collector | |
27 | * Heiko EiBfeldt : Missing verify_area check | |
28 | * Alan Cox : Started POSIXisms | |
29 | * Andreas Schwab : Replace inode by dentry for proper | |
30 | * reference counting | |
31 | * Kirk Petersen : Made this a module | |
32 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. | |
33 | * Lots of bug fixes. | |
34 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces | |
35 | * by above two patches. | |
36 | * Andrea Arcangeli : If possible we block in connect(2) | |
37 | * if the max backlog of the listen socket | |
38 | * is been reached. This won't break | |
39 | * old apps and it will avoid huge amount | |
40 | * of socks hashed (this for unix_gc() | |
41 | * performances reasons). | |
42 | * Security fix that limits the max | |
43 | * number of socks to 2*max_files and | |
44 | * the number of skb queueable in the | |
45 | * dgram receiver. | |
46 | * Artur Skawina : Hash function optimizations | |
47 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) | |
48 | * Malcolm Beattie : Set peercred for socketpair | |
49 | * Michal Ostrowski : Module initialization cleanup. | |
50 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, | |
51 | * the core infrastructure is doing that | |
52 | * for all net proto families now (2.5.69+) | |
53 | * | |
54 | * | |
55 | * Known differences from reference BSD that was tested: | |
56 | * | |
57 | * [TO FIX] | |
58 | * ECONNREFUSED is not returned from one end of a connected() socket to the | |
59 | * other the moment one end closes. | |
60 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark | |
61 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). | |
62 | * [NOT TO FIX] | |
63 | * accept() returns a path name even if the connecting socket has closed | |
64 | * in the meantime (BSD loses the path and gives up). | |
65 | * accept() returns 0 length path for an unbound connector. BSD returns 16 | |
66 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) | |
67 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. | |
68 | * BSD af_unix apparently has connect forgetting to block properly. | |
69 | * (need to check this with the POSIX spec in detail) | |
70 | * | |
71 | * Differences from 2.0.0-11-... (ANK) | |
72 | * Bug fixes and improvements. | |
73 | * - client shutdown killed server socket. | |
74 | * - removed all useless cli/sti pairs. | |
75 | * | |
76 | * Semantic changes/extensions. | |
77 | * - generic control message passing. | |
78 | * - SCM_CREDENTIALS control message. | |
79 | * - "Abstract" (not FS based) socket bindings. | |
80 | * Abstract names are sequences of bytes (not zero terminated) | |
81 | * started by 0, so that this name space does not intersect | |
82 | * with BSD names. | |
83 | */ | |
84 | ||
85 | #include <linux/module.h> | |
86 | #include <linux/config.h> | |
87 | #include <linux/kernel.h> | |
88 | #include <linux/major.h> | |
89 | #include <linux/signal.h> | |
90 | #include <linux/sched.h> | |
91 | #include <linux/errno.h> | |
92 | #include <linux/string.h> | |
93 | #include <linux/stat.h> | |
94 | #include <linux/dcache.h> | |
95 | #include <linux/namei.h> | |
96 | #include <linux/socket.h> | |
97 | #include <linux/un.h> | |
98 | #include <linux/fcntl.h> | |
99 | #include <linux/termios.h> | |
100 | #include <linux/sockios.h> | |
101 | #include <linux/net.h> | |
102 | #include <linux/in.h> | |
103 | #include <linux/fs.h> | |
104 | #include <linux/slab.h> | |
105 | #include <asm/uaccess.h> | |
106 | #include <linux/skbuff.h> | |
107 | #include <linux/netdevice.h> | |
108 | #include <net/sock.h> | |
109 | #include <linux/tcp.h> | |
110 | #include <net/af_unix.h> | |
111 | #include <linux/proc_fs.h> | |
112 | #include <linux/seq_file.h> | |
113 | #include <net/scm.h> | |
114 | #include <linux/init.h> | |
115 | #include <linux/poll.h> | |
116 | #include <linux/smp_lock.h> | |
117 | #include <linux/rtnetlink.h> | |
118 | #include <linux/mount.h> | |
119 | #include <net/checksum.h> | |
120 | #include <linux/security.h> | |
121 | ||
122 | int sysctl_unix_max_dgram_qlen = 10; | |
123 | ||
124 | struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; | |
125 | DEFINE_RWLOCK(unix_table_lock); | |
126 | static atomic_t unix_nr_socks = ATOMIC_INIT(0); | |
127 | ||
128 | #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) | |
129 | ||
130 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE) | |
131 | ||
132 | /* | |
133 | * SMP locking strategy: | |
134 | * hash table is protected with rwlock unix_table_lock | |
135 | * each socket state is protected by separate rwlock. | |
136 | */ | |
137 | ||
138 | static inline unsigned unix_hash_fold(unsigned hash) | |
139 | { | |
140 | hash ^= hash>>16; | |
141 | hash ^= hash>>8; | |
142 | return hash&(UNIX_HASH_SIZE-1); | |
143 | } | |
144 | ||
145 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
146 | ||
147 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
148 | { | |
149 | return unix_peer(osk) == sk; | |
150 | } | |
151 | ||
152 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
153 | { | |
154 | return (unix_peer(osk) == NULL || unix_our_peer(sk, osk)); | |
155 | } | |
156 | ||
157 | static struct sock *unix_peer_get(struct sock *s) | |
158 | { | |
159 | struct sock *peer; | |
160 | ||
161 | unix_state_rlock(s); | |
162 | peer = unix_peer(s); | |
163 | if (peer) | |
164 | sock_hold(peer); | |
165 | unix_state_runlock(s); | |
166 | return peer; | |
167 | } | |
168 | ||
169 | static inline void unix_release_addr(struct unix_address *addr) | |
170 | { | |
171 | if (atomic_dec_and_test(&addr->refcnt)) | |
172 | kfree(addr); | |
173 | } | |
174 | ||
175 | /* | |
176 | * Check unix socket name: | |
177 | * - should be not zero length. | |
178 | * - if started by not zero, should be NULL terminated (FS object) | |
179 | * - if started by zero, it is abstract name. | |
180 | */ | |
181 | ||
182 | static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp) | |
183 | { | |
184 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
185 | return -EINVAL; | |
186 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
187 | return -EINVAL; | |
188 | if (sunaddr->sun_path[0]) { | |
189 | /* | |
190 | * This may look like an off by one error but it is a bit more | |
191 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
192 | * sun_path[108] doesnt as such exist. However in kernel space | |
193 | * we are guaranteed that it is a valid memory location in our | |
194 | * kernel address buffer. | |
195 | */ | |
196 | ((char *)sunaddr)[len]=0; | |
197 | len = strlen(sunaddr->sun_path)+1+sizeof(short); | |
198 | return len; | |
199 | } | |
200 | ||
201 | *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0)); | |
202 | return len; | |
203 | } | |
204 | ||
205 | static void __unix_remove_socket(struct sock *sk) | |
206 | { | |
207 | sk_del_node_init(sk); | |
208 | } | |
209 | ||
210 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
211 | { | |
212 | BUG_TRAP(sk_unhashed(sk)); | |
213 | sk_add_node(sk, list); | |
214 | } | |
215 | ||
216 | static inline void unix_remove_socket(struct sock *sk) | |
217 | { | |
218 | write_lock(&unix_table_lock); | |
219 | __unix_remove_socket(sk); | |
220 | write_unlock(&unix_table_lock); | |
221 | } | |
222 | ||
223 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
224 | { | |
225 | write_lock(&unix_table_lock); | |
226 | __unix_insert_socket(list, sk); | |
227 | write_unlock(&unix_table_lock); | |
228 | } | |
229 | ||
230 | static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname, | |
231 | int len, int type, unsigned hash) | |
232 | { | |
233 | struct sock *s; | |
234 | struct hlist_node *node; | |
235 | ||
236 | sk_for_each(s, node, &unix_socket_table[hash ^ type]) { | |
237 | struct unix_sock *u = unix_sk(s); | |
238 | ||
239 | if (u->addr->len == len && | |
240 | !memcmp(u->addr->name, sunname, len)) | |
241 | goto found; | |
242 | } | |
243 | s = NULL; | |
244 | found: | |
245 | return s; | |
246 | } | |
247 | ||
248 | static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname, | |
249 | int len, int type, | |
250 | unsigned hash) | |
251 | { | |
252 | struct sock *s; | |
253 | ||
254 | read_lock(&unix_table_lock); | |
255 | s = __unix_find_socket_byname(sunname, len, type, hash); | |
256 | if (s) | |
257 | sock_hold(s); | |
258 | read_unlock(&unix_table_lock); | |
259 | return s; | |
260 | } | |
261 | ||
262 | static struct sock *unix_find_socket_byinode(struct inode *i) | |
263 | { | |
264 | struct sock *s; | |
265 | struct hlist_node *node; | |
266 | ||
267 | read_lock(&unix_table_lock); | |
268 | sk_for_each(s, node, | |
269 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { | |
270 | struct dentry *dentry = unix_sk(s)->dentry; | |
271 | ||
272 | if(dentry && dentry->d_inode == i) | |
273 | { | |
274 | sock_hold(s); | |
275 | goto found; | |
276 | } | |
277 | } | |
278 | s = NULL; | |
279 | found: | |
280 | read_unlock(&unix_table_lock); | |
281 | return s; | |
282 | } | |
283 | ||
284 | static inline int unix_writable(struct sock *sk) | |
285 | { | |
286 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
287 | } | |
288 | ||
289 | static void unix_write_space(struct sock *sk) | |
290 | { | |
291 | read_lock(&sk->sk_callback_lock); | |
292 | if (unix_writable(sk)) { | |
293 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
294 | wake_up_interruptible(sk->sk_sleep); | |
295 | sk_wake_async(sk, 2, POLL_OUT); | |
296 | } | |
297 | read_unlock(&sk->sk_callback_lock); | |
298 | } | |
299 | ||
300 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
301 | * queue of packets arrived from previous peer. First, it allows to do | |
302 | * flow control based only on wmem_alloc; second, sk connected to peer | |
303 | * may receive messages only from that peer. */ | |
304 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
305 | { | |
306 | if (skb_queue_len(&sk->sk_receive_queue)) { | |
307 | skb_queue_purge(&sk->sk_receive_queue); | |
308 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
309 | ||
310 | /* If one link of bidirectional dgram pipe is disconnected, | |
311 | * we signal error. Messages are lost. Do not make this, | |
312 | * when peer was not connected to us. | |
313 | */ | |
314 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
315 | other->sk_err = ECONNRESET; | |
316 | other->sk_error_report(other); | |
317 | } | |
318 | } | |
319 | } | |
320 | ||
321 | static void unix_sock_destructor(struct sock *sk) | |
322 | { | |
323 | struct unix_sock *u = unix_sk(sk); | |
324 | ||
325 | skb_queue_purge(&sk->sk_receive_queue); | |
326 | ||
327 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
328 | BUG_TRAP(sk_unhashed(sk)); | |
329 | BUG_TRAP(!sk->sk_socket); | |
330 | if (!sock_flag(sk, SOCK_DEAD)) { | |
331 | printk("Attempt to release alive unix socket: %p\n", sk); | |
332 | return; | |
333 | } | |
334 | ||
335 | if (u->addr) | |
336 | unix_release_addr(u->addr); | |
337 | ||
338 | atomic_dec(&unix_nr_socks); | |
339 | #ifdef UNIX_REFCNT_DEBUG | |
340 | printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks)); | |
341 | #endif | |
342 | } | |
343 | ||
344 | static int unix_release_sock (struct sock *sk, int embrion) | |
345 | { | |
346 | struct unix_sock *u = unix_sk(sk); | |
347 | struct dentry *dentry; | |
348 | struct vfsmount *mnt; | |
349 | struct sock *skpair; | |
350 | struct sk_buff *skb; | |
351 | int state; | |
352 | ||
353 | unix_remove_socket(sk); | |
354 | ||
355 | /* Clear state */ | |
356 | unix_state_wlock(sk); | |
357 | sock_orphan(sk); | |
358 | sk->sk_shutdown = SHUTDOWN_MASK; | |
359 | dentry = u->dentry; | |
360 | u->dentry = NULL; | |
361 | mnt = u->mnt; | |
362 | u->mnt = NULL; | |
363 | state = sk->sk_state; | |
364 | sk->sk_state = TCP_CLOSE; | |
365 | unix_state_wunlock(sk); | |
366 | ||
367 | wake_up_interruptible_all(&u->peer_wait); | |
368 | ||
369 | skpair=unix_peer(sk); | |
370 | ||
371 | if (skpair!=NULL) { | |
372 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { | |
373 | unix_state_wlock(skpair); | |
374 | /* No more writes */ | |
375 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
376 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
377 | skpair->sk_err = ECONNRESET; | |
378 | unix_state_wunlock(skpair); | |
379 | skpair->sk_state_change(skpair); | |
380 | read_lock(&skpair->sk_callback_lock); | |
381 | sk_wake_async(skpair,1,POLL_HUP); | |
382 | read_unlock(&skpair->sk_callback_lock); | |
383 | } | |
384 | sock_put(skpair); /* It may now die */ | |
385 | unix_peer(sk) = NULL; | |
386 | } | |
387 | ||
388 | /* Try to flush out this socket. Throw out buffers at least */ | |
389 | ||
390 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
391 | if (state==TCP_LISTEN) | |
392 | unix_release_sock(skb->sk, 1); | |
393 | /* passed fds are erased in the kfree_skb hook */ | |
394 | kfree_skb(skb); | |
395 | } | |
396 | ||
397 | if (dentry) { | |
398 | dput(dentry); | |
399 | mntput(mnt); | |
400 | } | |
401 | ||
402 | sock_put(sk); | |
403 | ||
404 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
405 | ||
406 | /* | |
407 | * Fixme: BSD difference: In BSD all sockets connected to use get | |
408 | * ECONNRESET and we die on the spot. In Linux we behave | |
409 | * like files and pipes do and wait for the last | |
410 | * dereference. | |
411 | * | |
412 | * Can't we simply set sock->err? | |
413 | * | |
414 | * What the above comment does talk about? --ANK(980817) | |
415 | */ | |
416 | ||
417 | if (atomic_read(&unix_tot_inflight)) | |
418 | unix_gc(); /* Garbage collect fds */ | |
419 | ||
420 | return 0; | |
421 | } | |
422 | ||
423 | static int unix_listen(struct socket *sock, int backlog) | |
424 | { | |
425 | int err; | |
426 | struct sock *sk = sock->sk; | |
427 | struct unix_sock *u = unix_sk(sk); | |
428 | ||
429 | err = -EOPNOTSUPP; | |
430 | if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) | |
431 | goto out; /* Only stream/seqpacket sockets accept */ | |
432 | err = -EINVAL; | |
433 | if (!u->addr) | |
434 | goto out; /* No listens on an unbound socket */ | |
435 | unix_state_wlock(sk); | |
436 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) | |
437 | goto out_unlock; | |
438 | if (backlog > sk->sk_max_ack_backlog) | |
439 | wake_up_interruptible_all(&u->peer_wait); | |
440 | sk->sk_max_ack_backlog = backlog; | |
441 | sk->sk_state = TCP_LISTEN; | |
442 | /* set credentials so connect can copy them */ | |
443 | sk->sk_peercred.pid = current->tgid; | |
444 | sk->sk_peercred.uid = current->euid; | |
445 | sk->sk_peercred.gid = current->egid; | |
446 | err = 0; | |
447 | ||
448 | out_unlock: | |
449 | unix_state_wunlock(sk); | |
450 | out: | |
451 | return err; | |
452 | } | |
453 | ||
454 | static int unix_release(struct socket *); | |
455 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
456 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
457 | int addr_len, int flags); | |
458 | static int unix_socketpair(struct socket *, struct socket *); | |
459 | static int unix_accept(struct socket *, struct socket *, int); | |
460 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
461 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
462 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); | |
463 | static int unix_shutdown(struct socket *, int); | |
464 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
465 | struct msghdr *, size_t); | |
466 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
467 | struct msghdr *, size_t, int); | |
468 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
469 | struct msghdr *, size_t); | |
470 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
471 | struct msghdr *, size_t, int); | |
472 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
473 | int, int); | |
474 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
475 | struct msghdr *, size_t); | |
476 | ||
477 | static struct proto_ops unix_stream_ops = { | |
478 | .family = PF_UNIX, | |
479 | .owner = THIS_MODULE, | |
480 | .release = unix_release, | |
481 | .bind = unix_bind, | |
482 | .connect = unix_stream_connect, | |
483 | .socketpair = unix_socketpair, | |
484 | .accept = unix_accept, | |
485 | .getname = unix_getname, | |
486 | .poll = unix_poll, | |
487 | .ioctl = unix_ioctl, | |
488 | .listen = unix_listen, | |
489 | .shutdown = unix_shutdown, | |
490 | .setsockopt = sock_no_setsockopt, | |
491 | .getsockopt = sock_no_getsockopt, | |
492 | .sendmsg = unix_stream_sendmsg, | |
493 | .recvmsg = unix_stream_recvmsg, | |
494 | .mmap = sock_no_mmap, | |
495 | .sendpage = sock_no_sendpage, | |
496 | }; | |
497 | ||
498 | static struct proto_ops unix_dgram_ops = { | |
499 | .family = PF_UNIX, | |
500 | .owner = THIS_MODULE, | |
501 | .release = unix_release, | |
502 | .bind = unix_bind, | |
503 | .connect = unix_dgram_connect, | |
504 | .socketpair = unix_socketpair, | |
505 | .accept = sock_no_accept, | |
506 | .getname = unix_getname, | |
507 | .poll = datagram_poll, | |
508 | .ioctl = unix_ioctl, | |
509 | .listen = sock_no_listen, | |
510 | .shutdown = unix_shutdown, | |
511 | .setsockopt = sock_no_setsockopt, | |
512 | .getsockopt = sock_no_getsockopt, | |
513 | .sendmsg = unix_dgram_sendmsg, | |
514 | .recvmsg = unix_dgram_recvmsg, | |
515 | .mmap = sock_no_mmap, | |
516 | .sendpage = sock_no_sendpage, | |
517 | }; | |
518 | ||
519 | static struct proto_ops unix_seqpacket_ops = { | |
520 | .family = PF_UNIX, | |
521 | .owner = THIS_MODULE, | |
522 | .release = unix_release, | |
523 | .bind = unix_bind, | |
524 | .connect = unix_stream_connect, | |
525 | .socketpair = unix_socketpair, | |
526 | .accept = unix_accept, | |
527 | .getname = unix_getname, | |
528 | .poll = datagram_poll, | |
529 | .ioctl = unix_ioctl, | |
530 | .listen = unix_listen, | |
531 | .shutdown = unix_shutdown, | |
532 | .setsockopt = sock_no_setsockopt, | |
533 | .getsockopt = sock_no_getsockopt, | |
534 | .sendmsg = unix_seqpacket_sendmsg, | |
535 | .recvmsg = unix_dgram_recvmsg, | |
536 | .mmap = sock_no_mmap, | |
537 | .sendpage = sock_no_sendpage, | |
538 | }; | |
539 | ||
540 | static struct proto unix_proto = { | |
541 | .name = "UNIX", | |
542 | .owner = THIS_MODULE, | |
543 | .obj_size = sizeof(struct unix_sock), | |
544 | }; | |
545 | ||
546 | static struct sock * unix_create1(struct socket *sock) | |
547 | { | |
548 | struct sock *sk = NULL; | |
549 | struct unix_sock *u; | |
550 | ||
551 | if (atomic_read(&unix_nr_socks) >= 2*files_stat.max_files) | |
552 | goto out; | |
553 | ||
554 | sk = sk_alloc(PF_UNIX, GFP_KERNEL, &unix_proto, 1); | |
555 | if (!sk) | |
556 | goto out; | |
557 | ||
558 | atomic_inc(&unix_nr_socks); | |
559 | ||
560 | sock_init_data(sock,sk); | |
561 | ||
562 | sk->sk_write_space = unix_write_space; | |
563 | sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen; | |
564 | sk->sk_destruct = unix_sock_destructor; | |
565 | u = unix_sk(sk); | |
566 | u->dentry = NULL; | |
567 | u->mnt = NULL; | |
568 | rwlock_init(&u->lock); | |
569 | atomic_set(&u->inflight, sock ? 0 : -1); | |
570 | init_MUTEX(&u->readsem); /* single task reading lock */ | |
571 | init_waitqueue_head(&u->peer_wait); | |
572 | unix_insert_socket(unix_sockets_unbound, sk); | |
573 | out: | |
574 | return sk; | |
575 | } | |
576 | ||
577 | static int unix_create(struct socket *sock, int protocol) | |
578 | { | |
579 | if (protocol && protocol != PF_UNIX) | |
580 | return -EPROTONOSUPPORT; | |
581 | ||
582 | sock->state = SS_UNCONNECTED; | |
583 | ||
584 | switch (sock->type) { | |
585 | case SOCK_STREAM: | |
586 | sock->ops = &unix_stream_ops; | |
587 | break; | |
588 | /* | |
589 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
590 | * nothing uses it. | |
591 | */ | |
592 | case SOCK_RAW: | |
593 | sock->type=SOCK_DGRAM; | |
594 | case SOCK_DGRAM: | |
595 | sock->ops = &unix_dgram_ops; | |
596 | break; | |
597 | case SOCK_SEQPACKET: | |
598 | sock->ops = &unix_seqpacket_ops; | |
599 | break; | |
600 | default: | |
601 | return -ESOCKTNOSUPPORT; | |
602 | } | |
603 | ||
604 | return unix_create1(sock) ? 0 : -ENOMEM; | |
605 | } | |
606 | ||
607 | static int unix_release(struct socket *sock) | |
608 | { | |
609 | struct sock *sk = sock->sk; | |
610 | ||
611 | if (!sk) | |
612 | return 0; | |
613 | ||
614 | sock->sk = NULL; | |
615 | ||
616 | return unix_release_sock (sk, 0); | |
617 | } | |
618 | ||
619 | static int unix_autobind(struct socket *sock) | |
620 | { | |
621 | struct sock *sk = sock->sk; | |
622 | struct unix_sock *u = unix_sk(sk); | |
623 | static u32 ordernum = 1; | |
624 | struct unix_address * addr; | |
625 | int err; | |
626 | ||
627 | down(&u->readsem); | |
628 | ||
629 | err = 0; | |
630 | if (u->addr) | |
631 | goto out; | |
632 | ||
633 | err = -ENOMEM; | |
634 | addr = kmalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); | |
635 | if (!addr) | |
636 | goto out; | |
637 | ||
638 | memset(addr, 0, sizeof(*addr) + sizeof(short) + 16); | |
639 | addr->name->sun_family = AF_UNIX; | |
640 | atomic_set(&addr->refcnt, 1); | |
641 | ||
642 | retry: | |
643 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
644 | addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0)); | |
645 | ||
646 | write_lock(&unix_table_lock); | |
647 | ordernum = (ordernum+1)&0xFFFFF; | |
648 | ||
649 | if (__unix_find_socket_byname(addr->name, addr->len, sock->type, | |
650 | addr->hash)) { | |
651 | write_unlock(&unix_table_lock); | |
652 | /* Sanity yield. It is unusual case, but yet... */ | |
653 | if (!(ordernum&0xFF)) | |
654 | yield(); | |
655 | goto retry; | |
656 | } | |
657 | addr->hash ^= sk->sk_type; | |
658 | ||
659 | __unix_remove_socket(sk); | |
660 | u->addr = addr; | |
661 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
662 | write_unlock(&unix_table_lock); | |
663 | err = 0; | |
664 | ||
665 | out: up(&u->readsem); | |
666 | return err; | |
667 | } | |
668 | ||
669 | static struct sock *unix_find_other(struct sockaddr_un *sunname, int len, | |
670 | int type, unsigned hash, int *error) | |
671 | { | |
672 | struct sock *u; | |
673 | struct nameidata nd; | |
674 | int err = 0; | |
675 | ||
676 | if (sunname->sun_path[0]) { | |
677 | err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd); | |
678 | if (err) | |
679 | goto fail; | |
680 | err = permission(nd.dentry->d_inode,MAY_WRITE, &nd); | |
681 | if (err) | |
682 | goto put_fail; | |
683 | ||
684 | err = -ECONNREFUSED; | |
685 | if (!S_ISSOCK(nd.dentry->d_inode->i_mode)) | |
686 | goto put_fail; | |
687 | u=unix_find_socket_byinode(nd.dentry->d_inode); | |
688 | if (!u) | |
689 | goto put_fail; | |
690 | ||
691 | if (u->sk_type == type) | |
692 | touch_atime(nd.mnt, nd.dentry); | |
693 | ||
694 | path_release(&nd); | |
695 | ||
696 | err=-EPROTOTYPE; | |
697 | if (u->sk_type != type) { | |
698 | sock_put(u); | |
699 | goto fail; | |
700 | } | |
701 | } else { | |
702 | err = -ECONNREFUSED; | |
703 | u=unix_find_socket_byname(sunname, len, type, hash); | |
704 | if (u) { | |
705 | struct dentry *dentry; | |
706 | dentry = unix_sk(u)->dentry; | |
707 | if (dentry) | |
708 | touch_atime(unix_sk(u)->mnt, dentry); | |
709 | } else | |
710 | goto fail; | |
711 | } | |
712 | return u; | |
713 | ||
714 | put_fail: | |
715 | path_release(&nd); | |
716 | fail: | |
717 | *error=err; | |
718 | return NULL; | |
719 | } | |
720 | ||
721 | ||
722 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
723 | { | |
724 | struct sock *sk = sock->sk; | |
725 | struct unix_sock *u = unix_sk(sk); | |
726 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
727 | struct dentry * dentry = NULL; | |
728 | struct nameidata nd; | |
729 | int err; | |
730 | unsigned hash; | |
731 | struct unix_address *addr; | |
732 | struct hlist_head *list; | |
733 | ||
734 | err = -EINVAL; | |
735 | if (sunaddr->sun_family != AF_UNIX) | |
736 | goto out; | |
737 | ||
738 | if (addr_len==sizeof(short)) { | |
739 | err = unix_autobind(sock); | |
740 | goto out; | |
741 | } | |
742 | ||
743 | err = unix_mkname(sunaddr, addr_len, &hash); | |
744 | if (err < 0) | |
745 | goto out; | |
746 | addr_len = err; | |
747 | ||
748 | down(&u->readsem); | |
749 | ||
750 | err = -EINVAL; | |
751 | if (u->addr) | |
752 | goto out_up; | |
753 | ||
754 | err = -ENOMEM; | |
755 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
756 | if (!addr) | |
757 | goto out_up; | |
758 | ||
759 | memcpy(addr->name, sunaddr, addr_len); | |
760 | addr->len = addr_len; | |
761 | addr->hash = hash ^ sk->sk_type; | |
762 | atomic_set(&addr->refcnt, 1); | |
763 | ||
764 | if (sunaddr->sun_path[0]) { | |
765 | unsigned int mode; | |
766 | err = 0; | |
767 | /* | |
768 | * Get the parent directory, calculate the hash for last | |
769 | * component. | |
770 | */ | |
771 | err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); | |
772 | if (err) | |
773 | goto out_mknod_parent; | |
774 | /* | |
775 | * Yucky last component or no last component at all? | |
776 | * (foo/., foo/.., /////) | |
777 | */ | |
778 | err = -EEXIST; | |
779 | if (nd.last_type != LAST_NORM) | |
780 | goto out_mknod; | |
781 | /* | |
782 | * Lock the directory. | |
783 | */ | |
784 | down(&nd.dentry->d_inode->i_sem); | |
785 | /* | |
786 | * Do the final lookup. | |
787 | */ | |
788 | dentry = lookup_hash(&nd.last, nd.dentry); | |
789 | err = PTR_ERR(dentry); | |
790 | if (IS_ERR(dentry)) | |
791 | goto out_mknod_unlock; | |
792 | err = -ENOENT; | |
793 | /* | |
794 | * Special case - lookup gave negative, but... we had foo/bar/ | |
795 | * From the vfs_mknod() POV we just have a negative dentry - | |
796 | * all is fine. Let's be bastards - you had / on the end, you've | |
797 | * been asking for (non-existent) directory. -ENOENT for you. | |
798 | */ | |
799 | if (nd.last.name[nd.last.len] && !dentry->d_inode) | |
800 | goto out_mknod_dput; | |
801 | /* | |
802 | * All right, let's create it. | |
803 | */ | |
804 | mode = S_IFSOCK | | |
805 | (SOCK_INODE(sock)->i_mode & ~current->fs->umask); | |
806 | err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0); | |
807 | if (err) | |
808 | goto out_mknod_dput; | |
809 | up(&nd.dentry->d_inode->i_sem); | |
810 | dput(nd.dentry); | |
811 | nd.dentry = dentry; | |
812 | ||
813 | addr->hash = UNIX_HASH_SIZE; | |
814 | } | |
815 | ||
816 | write_lock(&unix_table_lock); | |
817 | ||
818 | if (!sunaddr->sun_path[0]) { | |
819 | err = -EADDRINUSE; | |
820 | if (__unix_find_socket_byname(sunaddr, addr_len, | |
821 | sk->sk_type, hash)) { | |
822 | unix_release_addr(addr); | |
823 | goto out_unlock; | |
824 | } | |
825 | ||
826 | list = &unix_socket_table[addr->hash]; | |
827 | } else { | |
828 | list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; | |
829 | u->dentry = nd.dentry; | |
830 | u->mnt = nd.mnt; | |
831 | } | |
832 | ||
833 | err = 0; | |
834 | __unix_remove_socket(sk); | |
835 | u->addr = addr; | |
836 | __unix_insert_socket(list, sk); | |
837 | ||
838 | out_unlock: | |
839 | write_unlock(&unix_table_lock); | |
840 | out_up: | |
841 | up(&u->readsem); | |
842 | out: | |
843 | return err; | |
844 | ||
845 | out_mknod_dput: | |
846 | dput(dentry); | |
847 | out_mknod_unlock: | |
848 | up(&nd.dentry->d_inode->i_sem); | |
849 | out_mknod: | |
850 | path_release(&nd); | |
851 | out_mknod_parent: | |
852 | if (err==-EEXIST) | |
853 | err=-EADDRINUSE; | |
854 | unix_release_addr(addr); | |
855 | goto out_up; | |
856 | } | |
857 | ||
858 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, | |
859 | int alen, int flags) | |
860 | { | |
861 | struct sock *sk = sock->sk; | |
862 | struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr; | |
863 | struct sock *other; | |
864 | unsigned hash; | |
865 | int err; | |
866 | ||
867 | if (addr->sa_family != AF_UNSPEC) { | |
868 | err = unix_mkname(sunaddr, alen, &hash); | |
869 | if (err < 0) | |
870 | goto out; | |
871 | alen = err; | |
872 | ||
873 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
874 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
875 | goto out; | |
876 | ||
877 | other=unix_find_other(sunaddr, alen, sock->type, hash, &err); | |
878 | if (!other) | |
879 | goto out; | |
880 | ||
881 | unix_state_wlock(sk); | |
882 | ||
883 | err = -EPERM; | |
884 | if (!unix_may_send(sk, other)) | |
885 | goto out_unlock; | |
886 | ||
887 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
888 | if (err) | |
889 | goto out_unlock; | |
890 | ||
891 | } else { | |
892 | /* | |
893 | * 1003.1g breaking connected state with AF_UNSPEC | |
894 | */ | |
895 | other = NULL; | |
896 | unix_state_wlock(sk); | |
897 | } | |
898 | ||
899 | /* | |
900 | * If it was connected, reconnect. | |
901 | */ | |
902 | if (unix_peer(sk)) { | |
903 | struct sock *old_peer = unix_peer(sk); | |
904 | unix_peer(sk)=other; | |
905 | unix_state_wunlock(sk); | |
906 | ||
907 | if (other != old_peer) | |
908 | unix_dgram_disconnected(sk, old_peer); | |
909 | sock_put(old_peer); | |
910 | } else { | |
911 | unix_peer(sk)=other; | |
912 | unix_state_wunlock(sk); | |
913 | } | |
914 | return 0; | |
915 | ||
916 | out_unlock: | |
917 | unix_state_wunlock(sk); | |
918 | sock_put(other); | |
919 | out: | |
920 | return err; | |
921 | } | |
922 | ||
923 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
924 | { | |
925 | struct unix_sock *u = unix_sk(other); | |
926 | int sched; | |
927 | DEFINE_WAIT(wait); | |
928 | ||
929 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
930 | ||
931 | sched = !sock_flag(other, SOCK_DEAD) && | |
932 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
933 | (skb_queue_len(&other->sk_receive_queue) > | |
934 | other->sk_max_ack_backlog); | |
935 | ||
936 | unix_state_runlock(other); | |
937 | ||
938 | if (sched) | |
939 | timeo = schedule_timeout(timeo); | |
940 | ||
941 | finish_wait(&u->peer_wait, &wait); | |
942 | return timeo; | |
943 | } | |
944 | ||
945 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
946 | int addr_len, int flags) | |
947 | { | |
948 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
949 | struct sock *sk = sock->sk; | |
950 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; | |
951 | struct sock *newsk = NULL; | |
952 | struct sock *other = NULL; | |
953 | struct sk_buff *skb = NULL; | |
954 | unsigned hash; | |
955 | int st; | |
956 | int err; | |
957 | long timeo; | |
958 | ||
959 | err = unix_mkname(sunaddr, addr_len, &hash); | |
960 | if (err < 0) | |
961 | goto out; | |
962 | addr_len = err; | |
963 | ||
964 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
965 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
966 | goto out; | |
967 | ||
968 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
969 | ||
970 | /* First of all allocate resources. | |
971 | If we will make it after state is locked, | |
972 | we will have to recheck all again in any case. | |
973 | */ | |
974 | ||
975 | err = -ENOMEM; | |
976 | ||
977 | /* create new sock for complete connection */ | |
978 | newsk = unix_create1(NULL); | |
979 | if (newsk == NULL) | |
980 | goto out; | |
981 | ||
982 | /* Allocate skb for sending to listening sock */ | |
983 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
984 | if (skb == NULL) | |
985 | goto out; | |
986 | ||
987 | restart: | |
988 | /* Find listening sock. */ | |
989 | other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err); | |
990 | if (!other) | |
991 | goto out; | |
992 | ||
993 | /* Latch state of peer */ | |
994 | unix_state_rlock(other); | |
995 | ||
996 | /* Apparently VFS overslept socket death. Retry. */ | |
997 | if (sock_flag(other, SOCK_DEAD)) { | |
998 | unix_state_runlock(other); | |
999 | sock_put(other); | |
1000 | goto restart; | |
1001 | } | |
1002 | ||
1003 | err = -ECONNREFUSED; | |
1004 | if (other->sk_state != TCP_LISTEN) | |
1005 | goto out_unlock; | |
1006 | ||
1007 | if (skb_queue_len(&other->sk_receive_queue) > | |
1008 | other->sk_max_ack_backlog) { | |
1009 | err = -EAGAIN; | |
1010 | if (!timeo) | |
1011 | goto out_unlock; | |
1012 | ||
1013 | timeo = unix_wait_for_peer(other, timeo); | |
1014 | ||
1015 | err = sock_intr_errno(timeo); | |
1016 | if (signal_pending(current)) | |
1017 | goto out; | |
1018 | sock_put(other); | |
1019 | goto restart; | |
1020 | } | |
1021 | ||
1022 | /* Latch our state. | |
1023 | ||
1024 | It is tricky place. We need to grab write lock and cannot | |
1025 | drop lock on peer. It is dangerous because deadlock is | |
1026 | possible. Connect to self case and simultaneous | |
1027 | attempt to connect are eliminated by checking socket | |
1028 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1029 | check this before attempt to grab lock. | |
1030 | ||
1031 | Well, and we have to recheck the state after socket locked. | |
1032 | */ | |
1033 | st = sk->sk_state; | |
1034 | ||
1035 | switch (st) { | |
1036 | case TCP_CLOSE: | |
1037 | /* This is ok... continue with connect */ | |
1038 | break; | |
1039 | case TCP_ESTABLISHED: | |
1040 | /* Socket is already connected */ | |
1041 | err = -EISCONN; | |
1042 | goto out_unlock; | |
1043 | default: | |
1044 | err = -EINVAL; | |
1045 | goto out_unlock; | |
1046 | } | |
1047 | ||
1048 | unix_state_wlock(sk); | |
1049 | ||
1050 | if (sk->sk_state != st) { | |
1051 | unix_state_wunlock(sk); | |
1052 | unix_state_runlock(other); | |
1053 | sock_put(other); | |
1054 | goto restart; | |
1055 | } | |
1056 | ||
1057 | err = security_unix_stream_connect(sock, other->sk_socket, newsk); | |
1058 | if (err) { | |
1059 | unix_state_wunlock(sk); | |
1060 | goto out_unlock; | |
1061 | } | |
1062 | ||
1063 | /* The way is open! Fastly set all the necessary fields... */ | |
1064 | ||
1065 | sock_hold(sk); | |
1066 | unix_peer(newsk) = sk; | |
1067 | newsk->sk_state = TCP_ESTABLISHED; | |
1068 | newsk->sk_type = sk->sk_type; | |
1069 | newsk->sk_peercred.pid = current->tgid; | |
1070 | newsk->sk_peercred.uid = current->euid; | |
1071 | newsk->sk_peercred.gid = current->egid; | |
1072 | newu = unix_sk(newsk); | |
1073 | newsk->sk_sleep = &newu->peer_wait; | |
1074 | otheru = unix_sk(other); | |
1075 | ||
1076 | /* copy address information from listening to new sock*/ | |
1077 | if (otheru->addr) { | |
1078 | atomic_inc(&otheru->addr->refcnt); | |
1079 | newu->addr = otheru->addr; | |
1080 | } | |
1081 | if (otheru->dentry) { | |
1082 | newu->dentry = dget(otheru->dentry); | |
1083 | newu->mnt = mntget(otheru->mnt); | |
1084 | } | |
1085 | ||
1086 | /* Set credentials */ | |
1087 | sk->sk_peercred = other->sk_peercred; | |
1088 | ||
1089 | sock_hold(newsk); | |
1090 | unix_peer(sk) = newsk; | |
1091 | sock->state = SS_CONNECTED; | |
1092 | sk->sk_state = TCP_ESTABLISHED; | |
1093 | ||
1094 | unix_state_wunlock(sk); | |
1095 | ||
1096 | /* take ten and and send info to listening sock */ | |
1097 | spin_lock(&other->sk_receive_queue.lock); | |
1098 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1099 | /* Undo artificially decreased inflight after embrion | |
1100 | * is installed to listening socket. */ | |
1101 | atomic_inc(&newu->inflight); | |
1102 | spin_unlock(&other->sk_receive_queue.lock); | |
1103 | unix_state_runlock(other); | |
1104 | other->sk_data_ready(other, 0); | |
1105 | sock_put(other); | |
1106 | return 0; | |
1107 | ||
1108 | out_unlock: | |
1109 | if (other) | |
1110 | unix_state_runlock(other); | |
1111 | ||
1112 | out: | |
1113 | if (skb) | |
1114 | kfree_skb(skb); | |
1115 | if (newsk) | |
1116 | unix_release_sock(newsk, 0); | |
1117 | if (other) | |
1118 | sock_put(other); | |
1119 | return err; | |
1120 | } | |
1121 | ||
1122 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1123 | { | |
1124 | struct sock *ska=socka->sk, *skb = sockb->sk; | |
1125 | ||
1126 | /* Join our sockets back to back */ | |
1127 | sock_hold(ska); | |
1128 | sock_hold(skb); | |
1129 | unix_peer(ska)=skb; | |
1130 | unix_peer(skb)=ska; | |
1131 | ska->sk_peercred.pid = skb->sk_peercred.pid = current->tgid; | |
1132 | ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid; | |
1133 | ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid; | |
1134 | ||
1135 | if (ska->sk_type != SOCK_DGRAM) { | |
1136 | ska->sk_state = TCP_ESTABLISHED; | |
1137 | skb->sk_state = TCP_ESTABLISHED; | |
1138 | socka->state = SS_CONNECTED; | |
1139 | sockb->state = SS_CONNECTED; | |
1140 | } | |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) | |
1145 | { | |
1146 | struct sock *sk = sock->sk; | |
1147 | struct sock *tsk; | |
1148 | struct sk_buff *skb; | |
1149 | int err; | |
1150 | ||
1151 | err = -EOPNOTSUPP; | |
1152 | if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) | |
1153 | goto out; | |
1154 | ||
1155 | err = -EINVAL; | |
1156 | if (sk->sk_state != TCP_LISTEN) | |
1157 | goto out; | |
1158 | ||
1159 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1160 | * so that no locks are necessary. | |
1161 | */ | |
1162 | ||
1163 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1164 | if (!skb) { | |
1165 | /* This means receive shutdown. */ | |
1166 | if (err == 0) | |
1167 | err = -EINVAL; | |
1168 | goto out; | |
1169 | } | |
1170 | ||
1171 | tsk = skb->sk; | |
1172 | skb_free_datagram(sk, skb); | |
1173 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1174 | ||
1175 | /* attach accepted sock to socket */ | |
1176 | unix_state_wlock(tsk); | |
1177 | newsock->state = SS_CONNECTED; | |
1178 | sock_graft(tsk, newsock); | |
1179 | unix_state_wunlock(tsk); | |
1180 | return 0; | |
1181 | ||
1182 | out: | |
1183 | return err; | |
1184 | } | |
1185 | ||
1186 | ||
1187 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1188 | { | |
1189 | struct sock *sk = sock->sk; | |
1190 | struct unix_sock *u; | |
1191 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
1192 | int err = 0; | |
1193 | ||
1194 | if (peer) { | |
1195 | sk = unix_peer_get(sk); | |
1196 | ||
1197 | err = -ENOTCONN; | |
1198 | if (!sk) | |
1199 | goto out; | |
1200 | err = 0; | |
1201 | } else { | |
1202 | sock_hold(sk); | |
1203 | } | |
1204 | ||
1205 | u = unix_sk(sk); | |
1206 | unix_state_rlock(sk); | |
1207 | if (!u->addr) { | |
1208 | sunaddr->sun_family = AF_UNIX; | |
1209 | sunaddr->sun_path[0] = 0; | |
1210 | *uaddr_len = sizeof(short); | |
1211 | } else { | |
1212 | struct unix_address *addr = u->addr; | |
1213 | ||
1214 | *uaddr_len = addr->len; | |
1215 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1216 | } | |
1217 | unix_state_runlock(sk); | |
1218 | sock_put(sk); | |
1219 | out: | |
1220 | return err; | |
1221 | } | |
1222 | ||
1223 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1224 | { | |
1225 | int i; | |
1226 | ||
1227 | scm->fp = UNIXCB(skb).fp; | |
1228 | skb->destructor = sock_wfree; | |
1229 | UNIXCB(skb).fp = NULL; | |
1230 | ||
1231 | for (i=scm->fp->count-1; i>=0; i--) | |
1232 | unix_notinflight(scm->fp->fp[i]); | |
1233 | } | |
1234 | ||
1235 | static void unix_destruct_fds(struct sk_buff *skb) | |
1236 | { | |
1237 | struct scm_cookie scm; | |
1238 | memset(&scm, 0, sizeof(scm)); | |
1239 | unix_detach_fds(&scm, skb); | |
1240 | ||
1241 | /* Alas, it calls VFS */ | |
1242 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1243 | scm_destroy(&scm); | |
1244 | sock_wfree(skb); | |
1245 | } | |
1246 | ||
1247 | static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1248 | { | |
1249 | int i; | |
1250 | for (i=scm->fp->count-1; i>=0; i--) | |
1251 | unix_inflight(scm->fp->fp[i]); | |
1252 | UNIXCB(skb).fp = scm->fp; | |
1253 | skb->destructor = unix_destruct_fds; | |
1254 | scm->fp = NULL; | |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * Send AF_UNIX data. | |
1259 | */ | |
1260 | ||
1261 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1262 | struct msghdr *msg, size_t len) | |
1263 | { | |
1264 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1265 | struct sock *sk = sock->sk; | |
1266 | struct unix_sock *u = unix_sk(sk); | |
1267 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1268 | struct sock *other = NULL; | |
1269 | int namelen = 0; /* fake GCC */ | |
1270 | int err; | |
1271 | unsigned hash; | |
1272 | struct sk_buff *skb; | |
1273 | long timeo; | |
1274 | struct scm_cookie tmp_scm; | |
1275 | ||
1276 | if (NULL == siocb->scm) | |
1277 | siocb->scm = &tmp_scm; | |
1278 | err = scm_send(sock, msg, siocb->scm); | |
1279 | if (err < 0) | |
1280 | return err; | |
1281 | ||
1282 | err = -EOPNOTSUPP; | |
1283 | if (msg->msg_flags&MSG_OOB) | |
1284 | goto out; | |
1285 | ||
1286 | if (msg->msg_namelen) { | |
1287 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1288 | if (err < 0) | |
1289 | goto out; | |
1290 | namelen = err; | |
1291 | } else { | |
1292 | sunaddr = NULL; | |
1293 | err = -ENOTCONN; | |
1294 | other = unix_peer_get(sk); | |
1295 | if (!other) | |
1296 | goto out; | |
1297 | } | |
1298 | ||
1299 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
1300 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
1301 | goto out; | |
1302 | ||
1303 | err = -EMSGSIZE; | |
1304 | if (len > sk->sk_sndbuf - 32) | |
1305 | goto out; | |
1306 | ||
1307 | skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); | |
1308 | if (skb==NULL) | |
1309 | goto out; | |
1310 | ||
1311 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1312 | if (siocb->scm->fp) | |
1313 | unix_attach_fds(siocb->scm, skb); | |
1314 | ||
1315 | skb->h.raw = skb->data; | |
1316 | err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); | |
1317 | if (err) | |
1318 | goto out_free; | |
1319 | ||
1320 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1321 | ||
1322 | restart: | |
1323 | if (!other) { | |
1324 | err = -ECONNRESET; | |
1325 | if (sunaddr == NULL) | |
1326 | goto out_free; | |
1327 | ||
1328 | other = unix_find_other(sunaddr, namelen, sk->sk_type, | |
1329 | hash, &err); | |
1330 | if (other==NULL) | |
1331 | goto out_free; | |
1332 | } | |
1333 | ||
1334 | unix_state_rlock(other); | |
1335 | err = -EPERM; | |
1336 | if (!unix_may_send(sk, other)) | |
1337 | goto out_unlock; | |
1338 | ||
1339 | if (sock_flag(other, SOCK_DEAD)) { | |
1340 | /* | |
1341 | * Check with 1003.1g - what should | |
1342 | * datagram error | |
1343 | */ | |
1344 | unix_state_runlock(other); | |
1345 | sock_put(other); | |
1346 | ||
1347 | err = 0; | |
1348 | unix_state_wlock(sk); | |
1349 | if (unix_peer(sk) == other) { | |
1350 | unix_peer(sk)=NULL; | |
1351 | unix_state_wunlock(sk); | |
1352 | ||
1353 | unix_dgram_disconnected(sk, other); | |
1354 | sock_put(other); | |
1355 | err = -ECONNREFUSED; | |
1356 | } else { | |
1357 | unix_state_wunlock(sk); | |
1358 | } | |
1359 | ||
1360 | other = NULL; | |
1361 | if (err) | |
1362 | goto out_free; | |
1363 | goto restart; | |
1364 | } | |
1365 | ||
1366 | err = -EPIPE; | |
1367 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1368 | goto out_unlock; | |
1369 | ||
1370 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1371 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1372 | if (err) | |
1373 | goto out_unlock; | |
1374 | } | |
1375 | ||
1376 | if (unix_peer(other) != sk && | |
1377 | (skb_queue_len(&other->sk_receive_queue) > | |
1378 | other->sk_max_ack_backlog)) { | |
1379 | if (!timeo) { | |
1380 | err = -EAGAIN; | |
1381 | goto out_unlock; | |
1382 | } | |
1383 | ||
1384 | timeo = unix_wait_for_peer(other, timeo); | |
1385 | ||
1386 | err = sock_intr_errno(timeo); | |
1387 | if (signal_pending(current)) | |
1388 | goto out_free; | |
1389 | ||
1390 | goto restart; | |
1391 | } | |
1392 | ||
1393 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1394 | unix_state_runlock(other); | |
1395 | other->sk_data_ready(other, len); | |
1396 | sock_put(other); | |
1397 | scm_destroy(siocb->scm); | |
1398 | return len; | |
1399 | ||
1400 | out_unlock: | |
1401 | unix_state_runlock(other); | |
1402 | out_free: | |
1403 | kfree_skb(skb); | |
1404 | out: | |
1405 | if (other) | |
1406 | sock_put(other); | |
1407 | scm_destroy(siocb->scm); | |
1408 | return err; | |
1409 | } | |
1410 | ||
1411 | ||
1412 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1413 | struct msghdr *msg, size_t len) | |
1414 | { | |
1415 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1416 | struct sock *sk = sock->sk; | |
1417 | struct sock *other = NULL; | |
1418 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1419 | int err,size; | |
1420 | struct sk_buff *skb; | |
1421 | int sent=0; | |
1422 | struct scm_cookie tmp_scm; | |
1423 | ||
1424 | if (NULL == siocb->scm) | |
1425 | siocb->scm = &tmp_scm; | |
1426 | err = scm_send(sock, msg, siocb->scm); | |
1427 | if (err < 0) | |
1428 | return err; | |
1429 | ||
1430 | err = -EOPNOTSUPP; | |
1431 | if (msg->msg_flags&MSG_OOB) | |
1432 | goto out_err; | |
1433 | ||
1434 | if (msg->msg_namelen) { | |
1435 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1436 | goto out_err; | |
1437 | } else { | |
1438 | sunaddr = NULL; | |
1439 | err = -ENOTCONN; | |
1440 | other = unix_peer_get(sk); | |
1441 | if (!other) | |
1442 | goto out_err; | |
1443 | } | |
1444 | ||
1445 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1446 | goto pipe_err; | |
1447 | ||
1448 | while(sent < len) | |
1449 | { | |
1450 | /* | |
1451 | * Optimisation for the fact that under 0.01% of X messages typically | |
1452 | * need breaking up. | |
1453 | */ | |
1454 | ||
1455 | size=len-sent; | |
1456 | ||
1457 | /* Keep two messages in the pipe so it schedules better */ | |
1458 | if (size > sk->sk_sndbuf / 2 - 64) | |
1459 | size = sk->sk_sndbuf / 2 - 64; | |
1460 | ||
1461 | if (size > SKB_MAX_ALLOC) | |
1462 | size = SKB_MAX_ALLOC; | |
1463 | ||
1464 | /* | |
1465 | * Grab a buffer | |
1466 | */ | |
1467 | ||
1468 | skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); | |
1469 | ||
1470 | if (skb==NULL) | |
1471 | goto out_err; | |
1472 | ||
1473 | /* | |
1474 | * If you pass two values to the sock_alloc_send_skb | |
1475 | * it tries to grab the large buffer with GFP_NOFS | |
1476 | * (which can fail easily), and if it fails grab the | |
1477 | * fallback size buffer which is under a page and will | |
1478 | * succeed. [Alan] | |
1479 | */ | |
1480 | size = min_t(int, size, skb_tailroom(skb)); | |
1481 | ||
1482 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1483 | if (siocb->scm->fp) | |
1484 | unix_attach_fds(siocb->scm, skb); | |
1485 | ||
1486 | if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { | |
1487 | kfree_skb(skb); | |
1488 | goto out_err; | |
1489 | } | |
1490 | ||
1491 | unix_state_rlock(other); | |
1492 | ||
1493 | if (sock_flag(other, SOCK_DEAD) || | |
1494 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1495 | goto pipe_err_free; | |
1496 | ||
1497 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1498 | unix_state_runlock(other); | |
1499 | other->sk_data_ready(other, size); | |
1500 | sent+=size; | |
1501 | } | |
1502 | sock_put(other); | |
1503 | ||
1504 | scm_destroy(siocb->scm); | |
1505 | siocb->scm = NULL; | |
1506 | ||
1507 | return sent; | |
1508 | ||
1509 | pipe_err_free: | |
1510 | unix_state_runlock(other); | |
1511 | kfree_skb(skb); | |
1512 | pipe_err: | |
1513 | if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) | |
1514 | send_sig(SIGPIPE,current,0); | |
1515 | err = -EPIPE; | |
1516 | out_err: | |
1517 | if (other) | |
1518 | sock_put(other); | |
1519 | scm_destroy(siocb->scm); | |
1520 | siocb->scm = NULL; | |
1521 | return sent ? : err; | |
1522 | } | |
1523 | ||
1524 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1525 | struct msghdr *msg, size_t len) | |
1526 | { | |
1527 | int err; | |
1528 | struct sock *sk = sock->sk; | |
1529 | ||
1530 | err = sock_error(sk); | |
1531 | if (err) | |
1532 | return err; | |
1533 | ||
1534 | if (sk->sk_state != TCP_ESTABLISHED) | |
1535 | return -ENOTCONN; | |
1536 | ||
1537 | if (msg->msg_namelen) | |
1538 | msg->msg_namelen = 0; | |
1539 | ||
1540 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1541 | } | |
1542 | ||
1543 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) | |
1544 | { | |
1545 | struct unix_sock *u = unix_sk(sk); | |
1546 | ||
1547 | msg->msg_namelen = 0; | |
1548 | if (u->addr) { | |
1549 | msg->msg_namelen = u->addr->len; | |
1550 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1551 | } | |
1552 | } | |
1553 | ||
1554 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1555 | struct msghdr *msg, size_t size, | |
1556 | int flags) | |
1557 | { | |
1558 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1559 | struct scm_cookie tmp_scm; | |
1560 | struct sock *sk = sock->sk; | |
1561 | struct unix_sock *u = unix_sk(sk); | |
1562 | int noblock = flags & MSG_DONTWAIT; | |
1563 | struct sk_buff *skb; | |
1564 | int err; | |
1565 | ||
1566 | err = -EOPNOTSUPP; | |
1567 | if (flags&MSG_OOB) | |
1568 | goto out; | |
1569 | ||
1570 | msg->msg_namelen = 0; | |
1571 | ||
1572 | down(&u->readsem); | |
1573 | ||
1574 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
1575 | if (!skb) | |
1576 | goto out_unlock; | |
1577 | ||
1578 | wake_up_interruptible(&u->peer_wait); | |
1579 | ||
1580 | if (msg->msg_name) | |
1581 | unix_copy_addr(msg, skb->sk); | |
1582 | ||
1583 | if (size > skb->len) | |
1584 | size = skb->len; | |
1585 | else if (size < skb->len) | |
1586 | msg->msg_flags |= MSG_TRUNC; | |
1587 | ||
1588 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); | |
1589 | if (err) | |
1590 | goto out_free; | |
1591 | ||
1592 | if (!siocb->scm) { | |
1593 | siocb->scm = &tmp_scm; | |
1594 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1595 | } | |
1596 | siocb->scm->creds = *UNIXCREDS(skb); | |
1597 | ||
1598 | if (!(flags & MSG_PEEK)) | |
1599 | { | |
1600 | if (UNIXCB(skb).fp) | |
1601 | unix_detach_fds(siocb->scm, skb); | |
1602 | } | |
1603 | else | |
1604 | { | |
1605 | /* It is questionable: on PEEK we could: | |
1606 | - do not return fds - good, but too simple 8) | |
1607 | - return fds, and do not return them on read (old strategy, | |
1608 | apparently wrong) | |
1609 | - clone fds (I chose it for now, it is the most universal | |
1610 | solution) | |
1611 | ||
1612 | POSIX 1003.1g does not actually define this clearly | |
1613 | at all. POSIX 1003.1g doesn't define a lot of things | |
1614 | clearly however! | |
1615 | ||
1616 | */ | |
1617 | if (UNIXCB(skb).fp) | |
1618 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1619 | } | |
1620 | err = size; | |
1621 | ||
1622 | scm_recv(sock, msg, siocb->scm, flags); | |
1623 | ||
1624 | out_free: | |
1625 | skb_free_datagram(sk,skb); | |
1626 | out_unlock: | |
1627 | up(&u->readsem); | |
1628 | out: | |
1629 | return err; | |
1630 | } | |
1631 | ||
1632 | /* | |
1633 | * Sleep until data has arrive. But check for races.. | |
1634 | */ | |
1635 | ||
1636 | static long unix_stream_data_wait(struct sock * sk, long timeo) | |
1637 | { | |
1638 | DEFINE_WAIT(wait); | |
1639 | ||
1640 | unix_state_rlock(sk); | |
1641 | ||
1642 | for (;;) { | |
1643 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
1644 | ||
1645 | if (skb_queue_len(&sk->sk_receive_queue) || | |
1646 | sk->sk_err || | |
1647 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1648 | signal_pending(current) || | |
1649 | !timeo) | |
1650 | break; | |
1651 | ||
1652 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1653 | unix_state_runlock(sk); | |
1654 | timeo = schedule_timeout(timeo); | |
1655 | unix_state_rlock(sk); | |
1656 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1657 | } | |
1658 | ||
1659 | finish_wait(sk->sk_sleep, &wait); | |
1660 | unix_state_runlock(sk); | |
1661 | return timeo; | |
1662 | } | |
1663 | ||
1664 | ||
1665 | ||
1666 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1667 | struct msghdr *msg, size_t size, | |
1668 | int flags) | |
1669 | { | |
1670 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1671 | struct scm_cookie tmp_scm; | |
1672 | struct sock *sk = sock->sk; | |
1673 | struct unix_sock *u = unix_sk(sk); | |
1674 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1675 | int copied = 0; | |
1676 | int check_creds = 0; | |
1677 | int target; | |
1678 | int err = 0; | |
1679 | long timeo; | |
1680 | ||
1681 | err = -EINVAL; | |
1682 | if (sk->sk_state != TCP_ESTABLISHED) | |
1683 | goto out; | |
1684 | ||
1685 | err = -EOPNOTSUPP; | |
1686 | if (flags&MSG_OOB) | |
1687 | goto out; | |
1688 | ||
1689 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1690 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1691 | ||
1692 | msg->msg_namelen = 0; | |
1693 | ||
1694 | /* Lock the socket to prevent queue disordering | |
1695 | * while sleeps in memcpy_tomsg | |
1696 | */ | |
1697 | ||
1698 | if (!siocb->scm) { | |
1699 | siocb->scm = &tmp_scm; | |
1700 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1701 | } | |
1702 | ||
1703 | down(&u->readsem); | |
1704 | ||
1705 | do | |
1706 | { | |
1707 | int chunk; | |
1708 | struct sk_buff *skb; | |
1709 | ||
1710 | skb = skb_dequeue(&sk->sk_receive_queue); | |
1711 | if (skb==NULL) | |
1712 | { | |
1713 | if (copied >= target) | |
1714 | break; | |
1715 | ||
1716 | /* | |
1717 | * POSIX 1003.1g mandates this order. | |
1718 | */ | |
1719 | ||
1720 | if ((err = sock_error(sk)) != 0) | |
1721 | break; | |
1722 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1723 | break; | |
1724 | err = -EAGAIN; | |
1725 | if (!timeo) | |
1726 | break; | |
1727 | up(&u->readsem); | |
1728 | ||
1729 | timeo = unix_stream_data_wait(sk, timeo); | |
1730 | ||
1731 | if (signal_pending(current)) { | |
1732 | err = sock_intr_errno(timeo); | |
1733 | goto out; | |
1734 | } | |
1735 | down(&u->readsem); | |
1736 | continue; | |
1737 | } | |
1738 | ||
1739 | if (check_creds) { | |
1740 | /* Never glue messages from different writers */ | |
1741 | if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { | |
1742 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1743 | break; | |
1744 | } | |
1745 | } else { | |
1746 | /* Copy credentials */ | |
1747 | siocb->scm->creds = *UNIXCREDS(skb); | |
1748 | check_creds = 1; | |
1749 | } | |
1750 | ||
1751 | /* Copy address just once */ | |
1752 | if (sunaddr) | |
1753 | { | |
1754 | unix_copy_addr(msg, skb->sk); | |
1755 | sunaddr = NULL; | |
1756 | } | |
1757 | ||
1758 | chunk = min_t(unsigned int, skb->len, size); | |
1759 | if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { | |
1760 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1761 | if (copied == 0) | |
1762 | copied = -EFAULT; | |
1763 | break; | |
1764 | } | |
1765 | copied += chunk; | |
1766 | size -= chunk; | |
1767 | ||
1768 | /* Mark read part of skb as used */ | |
1769 | if (!(flags & MSG_PEEK)) | |
1770 | { | |
1771 | skb_pull(skb, chunk); | |
1772 | ||
1773 | if (UNIXCB(skb).fp) | |
1774 | unix_detach_fds(siocb->scm, skb); | |
1775 | ||
1776 | /* put the skb back if we didn't use it up.. */ | |
1777 | if (skb->len) | |
1778 | { | |
1779 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1780 | break; | |
1781 | } | |
1782 | ||
1783 | kfree_skb(skb); | |
1784 | ||
1785 | if (siocb->scm->fp) | |
1786 | break; | |
1787 | } | |
1788 | else | |
1789 | { | |
1790 | /* It is questionable, see note in unix_dgram_recvmsg. | |
1791 | */ | |
1792 | if (UNIXCB(skb).fp) | |
1793 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1794 | ||
1795 | /* put message back and return */ | |
1796 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1797 | break; | |
1798 | } | |
1799 | } while (size); | |
1800 | ||
1801 | up(&u->readsem); | |
1802 | scm_recv(sock, msg, siocb->scm, flags); | |
1803 | out: | |
1804 | return copied ? : err; | |
1805 | } | |
1806 | ||
1807 | static int unix_shutdown(struct socket *sock, int mode) | |
1808 | { | |
1809 | struct sock *sk = sock->sk; | |
1810 | struct sock *other; | |
1811 | ||
1812 | mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); | |
1813 | ||
1814 | if (mode) { | |
1815 | unix_state_wlock(sk); | |
1816 | sk->sk_shutdown |= mode; | |
1817 | other=unix_peer(sk); | |
1818 | if (other) | |
1819 | sock_hold(other); | |
1820 | unix_state_wunlock(sk); | |
1821 | sk->sk_state_change(sk); | |
1822 | ||
1823 | if (other && | |
1824 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
1825 | ||
1826 | int peer_mode = 0; | |
1827 | ||
1828 | if (mode&RCV_SHUTDOWN) | |
1829 | peer_mode |= SEND_SHUTDOWN; | |
1830 | if (mode&SEND_SHUTDOWN) | |
1831 | peer_mode |= RCV_SHUTDOWN; | |
1832 | unix_state_wlock(other); | |
1833 | other->sk_shutdown |= peer_mode; | |
1834 | unix_state_wunlock(other); | |
1835 | other->sk_state_change(other); | |
1836 | read_lock(&other->sk_callback_lock); | |
1837 | if (peer_mode == SHUTDOWN_MASK) | |
1838 | sk_wake_async(other,1,POLL_HUP); | |
1839 | else if (peer_mode & RCV_SHUTDOWN) | |
1840 | sk_wake_async(other,1,POLL_IN); | |
1841 | read_unlock(&other->sk_callback_lock); | |
1842 | } | |
1843 | if (other) | |
1844 | sock_put(other); | |
1845 | } | |
1846 | return 0; | |
1847 | } | |
1848 | ||
1849 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1850 | { | |
1851 | struct sock *sk = sock->sk; | |
1852 | long amount=0; | |
1853 | int err; | |
1854 | ||
1855 | switch(cmd) | |
1856 | { | |
1857 | case SIOCOUTQ: | |
1858 | amount = atomic_read(&sk->sk_wmem_alloc); | |
1859 | err = put_user(amount, (int __user *)arg); | |
1860 | break; | |
1861 | case SIOCINQ: | |
1862 | { | |
1863 | struct sk_buff *skb; | |
1864 | ||
1865 | if (sk->sk_state == TCP_LISTEN) { | |
1866 | err = -EINVAL; | |
1867 | break; | |
1868 | } | |
1869 | ||
1870 | spin_lock(&sk->sk_receive_queue.lock); | |
1871 | if (sk->sk_type == SOCK_STREAM || | |
1872 | sk->sk_type == SOCK_SEQPACKET) { | |
1873 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
1874 | amount += skb->len; | |
1875 | } else { | |
1876 | skb = skb_peek(&sk->sk_receive_queue); | |
1877 | if (skb) | |
1878 | amount=skb->len; | |
1879 | } | |
1880 | spin_unlock(&sk->sk_receive_queue.lock); | |
1881 | err = put_user(amount, (int __user *)arg); | |
1882 | break; | |
1883 | } | |
1884 | ||
1885 | default: | |
1886 | err = dev_ioctl(cmd, (void __user *)arg); | |
1887 | break; | |
1888 | } | |
1889 | return err; | |
1890 | } | |
1891 | ||
1892 | static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) | |
1893 | { | |
1894 | struct sock *sk = sock->sk; | |
1895 | unsigned int mask; | |
1896 | ||
1897 | poll_wait(file, sk->sk_sleep, wait); | |
1898 | mask = 0; | |
1899 | ||
1900 | /* exceptional events? */ | |
1901 | if (sk->sk_err) | |
1902 | mask |= POLLERR; | |
1903 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
1904 | mask |= POLLHUP; | |
1905 | ||
1906 | /* readable? */ | |
1907 | if (!skb_queue_empty(&sk->sk_receive_queue) || | |
1908 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1909 | mask |= POLLIN | POLLRDNORM; | |
1910 | ||
1911 | /* Connection-based need to check for termination and startup */ | |
1912 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) | |
1913 | mask |= POLLHUP; | |
1914 | ||
1915 | /* | |
1916 | * we set writable also when the other side has shut down the | |
1917 | * connection. This prevents stuck sockets. | |
1918 | */ | |
1919 | if (unix_writable(sk)) | |
1920 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
1921 | ||
1922 | return mask; | |
1923 | } | |
1924 | ||
1925 | ||
1926 | #ifdef CONFIG_PROC_FS | |
1927 | static struct sock *unix_seq_idx(int *iter, loff_t pos) | |
1928 | { | |
1929 | loff_t off = 0; | |
1930 | struct sock *s; | |
1931 | ||
1932 | for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) { | |
1933 | if (off == pos) | |
1934 | return s; | |
1935 | ++off; | |
1936 | } | |
1937 | return NULL; | |
1938 | } | |
1939 | ||
1940 | ||
1941 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) | |
1942 | { | |
1943 | read_lock(&unix_table_lock); | |
1944 | return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1); | |
1945 | } | |
1946 | ||
1947 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1948 | { | |
1949 | ++*pos; | |
1950 | ||
1951 | if (v == (void *)1) | |
1952 | return first_unix_socket(seq->private); | |
1953 | return next_unix_socket(seq->private, v); | |
1954 | } | |
1955 | ||
1956 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
1957 | { | |
1958 | read_unlock(&unix_table_lock); | |
1959 | } | |
1960 | ||
1961 | static int unix_seq_show(struct seq_file *seq, void *v) | |
1962 | { | |
1963 | ||
1964 | if (v == (void *)1) | |
1965 | seq_puts(seq, "Num RefCount Protocol Flags Type St " | |
1966 | "Inode Path\n"); | |
1967 | else { | |
1968 | struct sock *s = v; | |
1969 | struct unix_sock *u = unix_sk(s); | |
1970 | unix_state_rlock(s); | |
1971 | ||
1972 | seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", | |
1973 | s, | |
1974 | atomic_read(&s->sk_refcnt), | |
1975 | 0, | |
1976 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
1977 | s->sk_type, | |
1978 | s->sk_socket ? | |
1979 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
1980 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
1981 | sock_i_ino(s)); | |
1982 | ||
1983 | if (u->addr) { | |
1984 | int i, len; | |
1985 | seq_putc(seq, ' '); | |
1986 | ||
1987 | i = 0; | |
1988 | len = u->addr->len - sizeof(short); | |
1989 | if (!UNIX_ABSTRACT(s)) | |
1990 | len--; | |
1991 | else { | |
1992 | seq_putc(seq, '@'); | |
1993 | i++; | |
1994 | } | |
1995 | for ( ; i < len; i++) | |
1996 | seq_putc(seq, u->addr->name->sun_path[i]); | |
1997 | } | |
1998 | unix_state_runlock(s); | |
1999 | seq_putc(seq, '\n'); | |
2000 | } | |
2001 | ||
2002 | return 0; | |
2003 | } | |
2004 | ||
2005 | static struct seq_operations unix_seq_ops = { | |
2006 | .start = unix_seq_start, | |
2007 | .next = unix_seq_next, | |
2008 | .stop = unix_seq_stop, | |
2009 | .show = unix_seq_show, | |
2010 | }; | |
2011 | ||
2012 | ||
2013 | static int unix_seq_open(struct inode *inode, struct file *file) | |
2014 | { | |
2015 | struct seq_file *seq; | |
2016 | int rc = -ENOMEM; | |
2017 | int *iter = kmalloc(sizeof(int), GFP_KERNEL); | |
2018 | ||
2019 | if (!iter) | |
2020 | goto out; | |
2021 | ||
2022 | rc = seq_open(file, &unix_seq_ops); | |
2023 | if (rc) | |
2024 | goto out_kfree; | |
2025 | ||
2026 | seq = file->private_data; | |
2027 | seq->private = iter; | |
2028 | *iter = 0; | |
2029 | out: | |
2030 | return rc; | |
2031 | out_kfree: | |
2032 | kfree(iter); | |
2033 | goto out; | |
2034 | } | |
2035 | ||
2036 | static struct file_operations unix_seq_fops = { | |
2037 | .owner = THIS_MODULE, | |
2038 | .open = unix_seq_open, | |
2039 | .read = seq_read, | |
2040 | .llseek = seq_lseek, | |
2041 | .release = seq_release_private, | |
2042 | }; | |
2043 | ||
2044 | #endif | |
2045 | ||
2046 | static struct net_proto_family unix_family_ops = { | |
2047 | .family = PF_UNIX, | |
2048 | .create = unix_create, | |
2049 | .owner = THIS_MODULE, | |
2050 | }; | |
2051 | ||
2052 | #ifdef CONFIG_SYSCTL | |
2053 | extern void unix_sysctl_register(void); | |
2054 | extern void unix_sysctl_unregister(void); | |
2055 | #else | |
2056 | static inline void unix_sysctl_register(void) {} | |
2057 | static inline void unix_sysctl_unregister(void) {} | |
2058 | #endif | |
2059 | ||
2060 | static int __init af_unix_init(void) | |
2061 | { | |
2062 | int rc = -1; | |
2063 | struct sk_buff *dummy_skb; | |
2064 | ||
2065 | if (sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)) { | |
2066 | printk(KERN_CRIT "%s: panic\n", __FUNCTION__); | |
2067 | goto out; | |
2068 | } | |
2069 | ||
2070 | rc = proto_register(&unix_proto, 1); | |
2071 | if (rc != 0) { | |
2072 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
2073 | __FUNCTION__); | |
2074 | goto out; | |
2075 | } | |
2076 | ||
2077 | sock_register(&unix_family_ops); | |
2078 | #ifdef CONFIG_PROC_FS | |
2079 | proc_net_fops_create("unix", 0, &unix_seq_fops); | |
2080 | #endif | |
2081 | unix_sysctl_register(); | |
2082 | out: | |
2083 | return rc; | |
2084 | } | |
2085 | ||
2086 | static void __exit af_unix_exit(void) | |
2087 | { | |
2088 | sock_unregister(PF_UNIX); | |
2089 | unix_sysctl_unregister(); | |
2090 | proc_net_remove("unix"); | |
2091 | proto_unregister(&unix_proto); | |
2092 | } | |
2093 | ||
2094 | module_init(af_unix_init); | |
2095 | module_exit(af_unix_exit); | |
2096 | ||
2097 | MODULE_LICENSE("GPL"); | |
2098 | MODULE_ALIAS_NETPROTO(PF_UNIX); |