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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> | |
1da177e4 | 86 | #include <linux/kernel.h> |
1da177e4 LT |
87 | #include <linux/signal.h> |
88 | #include <linux/sched.h> | |
89 | #include <linux/errno.h> | |
90 | #include <linux/string.h> | |
91 | #include <linux/stat.h> | |
92 | #include <linux/dcache.h> | |
93 | #include <linux/namei.h> | |
94 | #include <linux/socket.h> | |
95 | #include <linux/un.h> | |
96 | #include <linux/fcntl.h> | |
97 | #include <linux/termios.h> | |
98 | #include <linux/sockios.h> | |
99 | #include <linux/net.h> | |
100 | #include <linux/in.h> | |
101 | #include <linux/fs.h> | |
102 | #include <linux/slab.h> | |
103 | #include <asm/uaccess.h> | |
104 | #include <linux/skbuff.h> | |
105 | #include <linux/netdevice.h> | |
106 | #include <net/sock.h> | |
c752f073 | 107 | #include <net/tcp_states.h> |
1da177e4 LT |
108 | #include <net/af_unix.h> |
109 | #include <linux/proc_fs.h> | |
110 | #include <linux/seq_file.h> | |
111 | #include <net/scm.h> | |
112 | #include <linux/init.h> | |
113 | #include <linux/poll.h> | |
1da177e4 LT |
114 | #include <linux/rtnetlink.h> |
115 | #include <linux/mount.h> | |
116 | #include <net/checksum.h> | |
117 | #include <linux/security.h> | |
118 | ||
18adaf06 | 119 | int sysctl_unix_max_dgram_qlen __read_mostly = 10; |
1da177e4 LT |
120 | |
121 | struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; | |
fbe9cc4a | 122 | DEFINE_SPINLOCK(unix_table_lock); |
1da177e4 LT |
123 | static atomic_t unix_nr_socks = ATOMIC_INIT(0); |
124 | ||
125 | #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) | |
126 | ||
127 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE) | |
128 | ||
877ce7c1 | 129 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 130 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 131 | { |
dc49c1f9 | 132 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
877ce7c1 CZ |
133 | } |
134 | ||
135 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
136 | { | |
dc49c1f9 | 137 | scm->secid = *UNIXSID(skb); |
877ce7c1 CZ |
138 | } |
139 | #else | |
dc49c1f9 | 140 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
141 | { } |
142 | ||
143 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
144 | { } | |
145 | #endif /* CONFIG_SECURITY_NETWORK */ | |
146 | ||
1da177e4 LT |
147 | /* |
148 | * SMP locking strategy: | |
fbe9cc4a | 149 | * hash table is protected with spinlock unix_table_lock |
1da177e4 LT |
150 | * each socket state is protected by separate rwlock. |
151 | */ | |
152 | ||
44bb9363 | 153 | static inline unsigned unix_hash_fold(__wsum n) |
1da177e4 | 154 | { |
44bb9363 | 155 | unsigned hash = (__force unsigned)n; |
1da177e4 LT |
156 | hash ^= hash>>16; |
157 | hash ^= hash>>8; | |
158 | return hash&(UNIX_HASH_SIZE-1); | |
159 | } | |
160 | ||
161 | #define unix_peer(sk) (unix_sk(sk)->peer) | |
162 | ||
163 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) | |
164 | { | |
165 | return unix_peer(osk) == sk; | |
166 | } | |
167 | ||
168 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
169 | { | |
170 | return (unix_peer(osk) == NULL || unix_our_peer(sk, osk)); | |
171 | } | |
172 | ||
173 | static struct sock *unix_peer_get(struct sock *s) | |
174 | { | |
175 | struct sock *peer; | |
176 | ||
1c92b4e5 | 177 | unix_state_lock(s); |
1da177e4 LT |
178 | peer = unix_peer(s); |
179 | if (peer) | |
180 | sock_hold(peer); | |
1c92b4e5 | 181 | unix_state_unlock(s); |
1da177e4 LT |
182 | return peer; |
183 | } | |
184 | ||
185 | static inline void unix_release_addr(struct unix_address *addr) | |
186 | { | |
187 | if (atomic_dec_and_test(&addr->refcnt)) | |
188 | kfree(addr); | |
189 | } | |
190 | ||
191 | /* | |
192 | * Check unix socket name: | |
193 | * - should be not zero length. | |
194 | * - if started by not zero, should be NULL terminated (FS object) | |
195 | * - if started by zero, it is abstract name. | |
196 | */ | |
ac7bfa62 | 197 | |
1da177e4 LT |
198 | static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp) |
199 | { | |
200 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) | |
201 | return -EINVAL; | |
202 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) | |
203 | return -EINVAL; | |
204 | if (sunaddr->sun_path[0]) { | |
205 | /* | |
206 | * This may look like an off by one error but it is a bit more | |
207 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
208 | * sun_path[108] doesnt as such exist. However in kernel space | |
209 | * we are guaranteed that it is a valid memory location in our | |
210 | * kernel address buffer. | |
211 | */ | |
212 | ((char *)sunaddr)[len]=0; | |
213 | len = strlen(sunaddr->sun_path)+1+sizeof(short); | |
214 | return len; | |
215 | } | |
216 | ||
217 | *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0)); | |
218 | return len; | |
219 | } | |
220 | ||
221 | static void __unix_remove_socket(struct sock *sk) | |
222 | { | |
223 | sk_del_node_init(sk); | |
224 | } | |
225 | ||
226 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
227 | { | |
228 | BUG_TRAP(sk_unhashed(sk)); | |
229 | sk_add_node(sk, list); | |
230 | } | |
231 | ||
232 | static inline void unix_remove_socket(struct sock *sk) | |
233 | { | |
fbe9cc4a | 234 | spin_lock(&unix_table_lock); |
1da177e4 | 235 | __unix_remove_socket(sk); |
fbe9cc4a | 236 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
237 | } |
238 | ||
239 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) | |
240 | { | |
fbe9cc4a | 241 | spin_lock(&unix_table_lock); |
1da177e4 | 242 | __unix_insert_socket(list, sk); |
fbe9cc4a | 243 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
244 | } |
245 | ||
246 | static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname, | |
247 | int len, int type, unsigned hash) | |
248 | { | |
249 | struct sock *s; | |
250 | struct hlist_node *node; | |
251 | ||
252 | sk_for_each(s, node, &unix_socket_table[hash ^ type]) { | |
253 | struct unix_sock *u = unix_sk(s); | |
254 | ||
255 | if (u->addr->len == len && | |
256 | !memcmp(u->addr->name, sunname, len)) | |
257 | goto found; | |
258 | } | |
259 | s = NULL; | |
260 | found: | |
261 | return s; | |
262 | } | |
263 | ||
264 | static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname, | |
265 | int len, int type, | |
266 | unsigned hash) | |
267 | { | |
268 | struct sock *s; | |
269 | ||
fbe9cc4a | 270 | spin_lock(&unix_table_lock); |
1da177e4 LT |
271 | s = __unix_find_socket_byname(sunname, len, type, hash); |
272 | if (s) | |
273 | sock_hold(s); | |
fbe9cc4a | 274 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
275 | return s; |
276 | } | |
277 | ||
278 | static struct sock *unix_find_socket_byinode(struct inode *i) | |
279 | { | |
280 | struct sock *s; | |
281 | struct hlist_node *node; | |
282 | ||
fbe9cc4a | 283 | spin_lock(&unix_table_lock); |
1da177e4 LT |
284 | sk_for_each(s, node, |
285 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { | |
286 | struct dentry *dentry = unix_sk(s)->dentry; | |
287 | ||
288 | if(dentry && dentry->d_inode == i) | |
289 | { | |
290 | sock_hold(s); | |
291 | goto found; | |
292 | } | |
293 | } | |
294 | s = NULL; | |
295 | found: | |
fbe9cc4a | 296 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
297 | return s; |
298 | } | |
299 | ||
300 | static inline int unix_writable(struct sock *sk) | |
301 | { | |
302 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; | |
303 | } | |
304 | ||
305 | static void unix_write_space(struct sock *sk) | |
306 | { | |
307 | read_lock(&sk->sk_callback_lock); | |
308 | if (unix_writable(sk)) { | |
309 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
310 | wake_up_interruptible(sk->sk_sleep); | |
311 | sk_wake_async(sk, 2, POLL_OUT); | |
312 | } | |
313 | read_unlock(&sk->sk_callback_lock); | |
314 | } | |
315 | ||
316 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
317 | * queue of packets arrived from previous peer. First, it allows to do | |
318 | * flow control based only on wmem_alloc; second, sk connected to peer | |
319 | * may receive messages only from that peer. */ | |
320 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
321 | { | |
b03efcfb | 322 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
323 | skb_queue_purge(&sk->sk_receive_queue); |
324 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
325 | ||
326 | /* If one link of bidirectional dgram pipe is disconnected, | |
327 | * we signal error. Messages are lost. Do not make this, | |
328 | * when peer was not connected to us. | |
329 | */ | |
330 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
331 | other->sk_err = ECONNRESET; | |
332 | other->sk_error_report(other); | |
333 | } | |
334 | } | |
335 | } | |
336 | ||
337 | static void unix_sock_destructor(struct sock *sk) | |
338 | { | |
339 | struct unix_sock *u = unix_sk(sk); | |
340 | ||
341 | skb_queue_purge(&sk->sk_receive_queue); | |
342 | ||
343 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
344 | BUG_TRAP(sk_unhashed(sk)); | |
345 | BUG_TRAP(!sk->sk_socket); | |
346 | if (!sock_flag(sk, SOCK_DEAD)) { | |
347 | printk("Attempt to release alive unix socket: %p\n", sk); | |
348 | return; | |
349 | } | |
350 | ||
351 | if (u->addr) | |
352 | unix_release_addr(u->addr); | |
353 | ||
354 | atomic_dec(&unix_nr_socks); | |
355 | #ifdef UNIX_REFCNT_DEBUG | |
356 | printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks)); | |
357 | #endif | |
358 | } | |
359 | ||
360 | static int unix_release_sock (struct sock *sk, int embrion) | |
361 | { | |
362 | struct unix_sock *u = unix_sk(sk); | |
363 | struct dentry *dentry; | |
364 | struct vfsmount *mnt; | |
365 | struct sock *skpair; | |
366 | struct sk_buff *skb; | |
367 | int state; | |
368 | ||
369 | unix_remove_socket(sk); | |
370 | ||
371 | /* Clear state */ | |
1c92b4e5 | 372 | unix_state_lock(sk); |
1da177e4 LT |
373 | sock_orphan(sk); |
374 | sk->sk_shutdown = SHUTDOWN_MASK; | |
375 | dentry = u->dentry; | |
376 | u->dentry = NULL; | |
377 | mnt = u->mnt; | |
378 | u->mnt = NULL; | |
379 | state = sk->sk_state; | |
380 | sk->sk_state = TCP_CLOSE; | |
1c92b4e5 | 381 | unix_state_unlock(sk); |
1da177e4 LT |
382 | |
383 | wake_up_interruptible_all(&u->peer_wait); | |
384 | ||
385 | skpair=unix_peer(sk); | |
386 | ||
387 | if (skpair!=NULL) { | |
388 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { | |
1c92b4e5 | 389 | unix_state_lock(skpair); |
1da177e4 LT |
390 | /* No more writes */ |
391 | skpair->sk_shutdown = SHUTDOWN_MASK; | |
392 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) | |
393 | skpair->sk_err = ECONNRESET; | |
1c92b4e5 | 394 | unix_state_unlock(skpair); |
1da177e4 LT |
395 | skpair->sk_state_change(skpair); |
396 | read_lock(&skpair->sk_callback_lock); | |
397 | sk_wake_async(skpair,1,POLL_HUP); | |
398 | read_unlock(&skpair->sk_callback_lock); | |
399 | } | |
400 | sock_put(skpair); /* It may now die */ | |
401 | unix_peer(sk) = NULL; | |
402 | } | |
403 | ||
404 | /* Try to flush out this socket. Throw out buffers at least */ | |
405 | ||
406 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
407 | if (state==TCP_LISTEN) | |
408 | unix_release_sock(skb->sk, 1); | |
409 | /* passed fds are erased in the kfree_skb hook */ | |
410 | kfree_skb(skb); | |
411 | } | |
412 | ||
413 | if (dentry) { | |
414 | dput(dentry); | |
415 | mntput(mnt); | |
416 | } | |
417 | ||
418 | sock_put(sk); | |
419 | ||
420 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
421 | ||
422 | /* | |
423 | * Fixme: BSD difference: In BSD all sockets connected to use get | |
424 | * ECONNRESET and we die on the spot. In Linux we behave | |
425 | * like files and pipes do and wait for the last | |
426 | * dereference. | |
427 | * | |
428 | * Can't we simply set sock->err? | |
429 | * | |
430 | * What the above comment does talk about? --ANK(980817) | |
431 | */ | |
432 | ||
433 | if (atomic_read(&unix_tot_inflight)) | |
ac7bfa62 | 434 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
435 | |
436 | return 0; | |
437 | } | |
438 | ||
439 | static int unix_listen(struct socket *sock, int backlog) | |
440 | { | |
441 | int err; | |
442 | struct sock *sk = sock->sk; | |
443 | struct unix_sock *u = unix_sk(sk); | |
444 | ||
445 | err = -EOPNOTSUPP; | |
446 | if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) | |
447 | goto out; /* Only stream/seqpacket sockets accept */ | |
448 | err = -EINVAL; | |
449 | if (!u->addr) | |
450 | goto out; /* No listens on an unbound socket */ | |
1c92b4e5 | 451 | unix_state_lock(sk); |
1da177e4 LT |
452 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
453 | goto out_unlock; | |
454 | if (backlog > sk->sk_max_ack_backlog) | |
455 | wake_up_interruptible_all(&u->peer_wait); | |
456 | sk->sk_max_ack_backlog = backlog; | |
457 | sk->sk_state = TCP_LISTEN; | |
458 | /* set credentials so connect can copy them */ | |
459 | sk->sk_peercred.pid = current->tgid; | |
460 | sk->sk_peercred.uid = current->euid; | |
461 | sk->sk_peercred.gid = current->egid; | |
462 | err = 0; | |
463 | ||
464 | out_unlock: | |
1c92b4e5 | 465 | unix_state_unlock(sk); |
1da177e4 LT |
466 | out: |
467 | return err; | |
468 | } | |
469 | ||
470 | static int unix_release(struct socket *); | |
471 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
472 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
473 | int addr_len, int flags); | |
474 | static int unix_socketpair(struct socket *, struct socket *); | |
475 | static int unix_accept(struct socket *, struct socket *, int); | |
476 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); | |
477 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); | |
478 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); | |
479 | static int unix_shutdown(struct socket *, int); | |
480 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, | |
481 | struct msghdr *, size_t); | |
482 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, | |
483 | struct msghdr *, size_t, int); | |
484 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, | |
485 | struct msghdr *, size_t); | |
486 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, | |
487 | struct msghdr *, size_t, int); | |
488 | static int unix_dgram_connect(struct socket *, struct sockaddr *, | |
489 | int, int); | |
490 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, | |
491 | struct msghdr *, size_t); | |
492 | ||
90ddc4f0 | 493 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
494 | .family = PF_UNIX, |
495 | .owner = THIS_MODULE, | |
496 | .release = unix_release, | |
497 | .bind = unix_bind, | |
498 | .connect = unix_stream_connect, | |
499 | .socketpair = unix_socketpair, | |
500 | .accept = unix_accept, | |
501 | .getname = unix_getname, | |
502 | .poll = unix_poll, | |
503 | .ioctl = unix_ioctl, | |
504 | .listen = unix_listen, | |
505 | .shutdown = unix_shutdown, | |
506 | .setsockopt = sock_no_setsockopt, | |
507 | .getsockopt = sock_no_getsockopt, | |
508 | .sendmsg = unix_stream_sendmsg, | |
509 | .recvmsg = unix_stream_recvmsg, | |
510 | .mmap = sock_no_mmap, | |
511 | .sendpage = sock_no_sendpage, | |
512 | }; | |
513 | ||
90ddc4f0 | 514 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
515 | .family = PF_UNIX, |
516 | .owner = THIS_MODULE, | |
517 | .release = unix_release, | |
518 | .bind = unix_bind, | |
519 | .connect = unix_dgram_connect, | |
520 | .socketpair = unix_socketpair, | |
521 | .accept = sock_no_accept, | |
522 | .getname = unix_getname, | |
523 | .poll = datagram_poll, | |
524 | .ioctl = unix_ioctl, | |
525 | .listen = sock_no_listen, | |
526 | .shutdown = unix_shutdown, | |
527 | .setsockopt = sock_no_setsockopt, | |
528 | .getsockopt = sock_no_getsockopt, | |
529 | .sendmsg = unix_dgram_sendmsg, | |
530 | .recvmsg = unix_dgram_recvmsg, | |
531 | .mmap = sock_no_mmap, | |
532 | .sendpage = sock_no_sendpage, | |
533 | }; | |
534 | ||
90ddc4f0 | 535 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
536 | .family = PF_UNIX, |
537 | .owner = THIS_MODULE, | |
538 | .release = unix_release, | |
539 | .bind = unix_bind, | |
540 | .connect = unix_stream_connect, | |
541 | .socketpair = unix_socketpair, | |
542 | .accept = unix_accept, | |
543 | .getname = unix_getname, | |
544 | .poll = datagram_poll, | |
545 | .ioctl = unix_ioctl, | |
546 | .listen = unix_listen, | |
547 | .shutdown = unix_shutdown, | |
548 | .setsockopt = sock_no_setsockopt, | |
549 | .getsockopt = sock_no_getsockopt, | |
550 | .sendmsg = unix_seqpacket_sendmsg, | |
551 | .recvmsg = unix_dgram_recvmsg, | |
552 | .mmap = sock_no_mmap, | |
553 | .sendpage = sock_no_sendpage, | |
554 | }; | |
555 | ||
556 | static struct proto unix_proto = { | |
557 | .name = "UNIX", | |
558 | .owner = THIS_MODULE, | |
559 | .obj_size = sizeof(struct unix_sock), | |
560 | }; | |
561 | ||
a09785a2 IM |
562 | /* |
563 | * AF_UNIX sockets do not interact with hardware, hence they | |
564 | * dont trigger interrupts - so it's safe for them to have | |
565 | * bh-unsafe locking for their sk_receive_queue.lock. Split off | |
566 | * this special lock-class by reinitializing the spinlock key: | |
567 | */ | |
568 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; | |
569 | ||
1da177e4 LT |
570 | static struct sock * unix_create1(struct socket *sock) |
571 | { | |
572 | struct sock *sk = NULL; | |
573 | struct unix_sock *u; | |
574 | ||
529bf6be | 575 | if (atomic_read(&unix_nr_socks) >= 2*get_max_files()) |
1da177e4 LT |
576 | goto out; |
577 | ||
578 | sk = sk_alloc(PF_UNIX, GFP_KERNEL, &unix_proto, 1); | |
579 | if (!sk) | |
580 | goto out; | |
581 | ||
582 | atomic_inc(&unix_nr_socks); | |
583 | ||
584 | sock_init_data(sock,sk); | |
a09785a2 IM |
585 | lockdep_set_class(&sk->sk_receive_queue.lock, |
586 | &af_unix_sk_receive_queue_lock_key); | |
1da177e4 LT |
587 | |
588 | sk->sk_write_space = unix_write_space; | |
589 | sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen; | |
590 | sk->sk_destruct = unix_sock_destructor; | |
591 | u = unix_sk(sk); | |
592 | u->dentry = NULL; | |
593 | u->mnt = NULL; | |
fd19f329 | 594 | spin_lock_init(&u->lock); |
1da177e4 | 595 | atomic_set(&u->inflight, sock ? 0 : -1); |
57b47a53 | 596 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 LT |
597 | init_waitqueue_head(&u->peer_wait); |
598 | unix_insert_socket(unix_sockets_unbound, sk); | |
599 | out: | |
600 | return sk; | |
601 | } | |
602 | ||
603 | static int unix_create(struct socket *sock, int protocol) | |
604 | { | |
605 | if (protocol && protocol != PF_UNIX) | |
606 | return -EPROTONOSUPPORT; | |
607 | ||
608 | sock->state = SS_UNCONNECTED; | |
609 | ||
610 | switch (sock->type) { | |
611 | case SOCK_STREAM: | |
612 | sock->ops = &unix_stream_ops; | |
613 | break; | |
614 | /* | |
615 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
616 | * nothing uses it. | |
617 | */ | |
618 | case SOCK_RAW: | |
619 | sock->type=SOCK_DGRAM; | |
620 | case SOCK_DGRAM: | |
621 | sock->ops = &unix_dgram_ops; | |
622 | break; | |
623 | case SOCK_SEQPACKET: | |
624 | sock->ops = &unix_seqpacket_ops; | |
625 | break; | |
626 | default: | |
627 | return -ESOCKTNOSUPPORT; | |
628 | } | |
629 | ||
630 | return unix_create1(sock) ? 0 : -ENOMEM; | |
631 | } | |
632 | ||
633 | static int unix_release(struct socket *sock) | |
634 | { | |
635 | struct sock *sk = sock->sk; | |
636 | ||
637 | if (!sk) | |
638 | return 0; | |
639 | ||
640 | sock->sk = NULL; | |
641 | ||
642 | return unix_release_sock (sk, 0); | |
643 | } | |
644 | ||
645 | static int unix_autobind(struct socket *sock) | |
646 | { | |
647 | struct sock *sk = sock->sk; | |
648 | struct unix_sock *u = unix_sk(sk); | |
649 | static u32 ordernum = 1; | |
650 | struct unix_address * addr; | |
651 | int err; | |
652 | ||
57b47a53 | 653 | mutex_lock(&u->readlock); |
1da177e4 LT |
654 | |
655 | err = 0; | |
656 | if (u->addr) | |
657 | goto out; | |
658 | ||
659 | err = -ENOMEM; | |
0da974f4 | 660 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
661 | if (!addr) |
662 | goto out; | |
663 | ||
1da177e4 LT |
664 | addr->name->sun_family = AF_UNIX; |
665 | atomic_set(&addr->refcnt, 1); | |
666 | ||
667 | retry: | |
668 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
669 | addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0)); | |
670 | ||
fbe9cc4a | 671 | spin_lock(&unix_table_lock); |
1da177e4 LT |
672 | ordernum = (ordernum+1)&0xFFFFF; |
673 | ||
674 | if (__unix_find_socket_byname(addr->name, addr->len, sock->type, | |
675 | addr->hash)) { | |
fbe9cc4a | 676 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
677 | /* Sanity yield. It is unusual case, but yet... */ |
678 | if (!(ordernum&0xFF)) | |
679 | yield(); | |
680 | goto retry; | |
681 | } | |
682 | addr->hash ^= sk->sk_type; | |
683 | ||
684 | __unix_remove_socket(sk); | |
685 | u->addr = addr; | |
686 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 687 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
688 | err = 0; |
689 | ||
57b47a53 | 690 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
691 | return err; |
692 | } | |
693 | ||
694 | static struct sock *unix_find_other(struct sockaddr_un *sunname, int len, | |
695 | int type, unsigned hash, int *error) | |
696 | { | |
697 | struct sock *u; | |
698 | struct nameidata nd; | |
699 | int err = 0; | |
ac7bfa62 | 700 | |
1da177e4 LT |
701 | if (sunname->sun_path[0]) { |
702 | err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd); | |
703 | if (err) | |
704 | goto fail; | |
e4543edd | 705 | err = vfs_permission(&nd, MAY_WRITE); |
1da177e4 LT |
706 | if (err) |
707 | goto put_fail; | |
708 | ||
709 | err = -ECONNREFUSED; | |
710 | if (!S_ISSOCK(nd.dentry->d_inode->i_mode)) | |
711 | goto put_fail; | |
712 | u=unix_find_socket_byinode(nd.dentry->d_inode); | |
713 | if (!u) | |
714 | goto put_fail; | |
715 | ||
716 | if (u->sk_type == type) | |
717 | touch_atime(nd.mnt, nd.dentry); | |
718 | ||
719 | path_release(&nd); | |
720 | ||
721 | err=-EPROTOTYPE; | |
722 | if (u->sk_type != type) { | |
723 | sock_put(u); | |
724 | goto fail; | |
725 | } | |
726 | } else { | |
727 | err = -ECONNREFUSED; | |
728 | u=unix_find_socket_byname(sunname, len, type, hash); | |
729 | if (u) { | |
730 | struct dentry *dentry; | |
731 | dentry = unix_sk(u)->dentry; | |
732 | if (dentry) | |
733 | touch_atime(unix_sk(u)->mnt, dentry); | |
734 | } else | |
735 | goto fail; | |
736 | } | |
737 | return u; | |
738 | ||
739 | put_fail: | |
740 | path_release(&nd); | |
741 | fail: | |
742 | *error=err; | |
743 | return NULL; | |
744 | } | |
745 | ||
746 | ||
747 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
748 | { | |
749 | struct sock *sk = sock->sk; | |
750 | struct unix_sock *u = unix_sk(sk); | |
751 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
752 | struct dentry * dentry = NULL; | |
753 | struct nameidata nd; | |
754 | int err; | |
755 | unsigned hash; | |
756 | struct unix_address *addr; | |
757 | struct hlist_head *list; | |
758 | ||
759 | err = -EINVAL; | |
760 | if (sunaddr->sun_family != AF_UNIX) | |
761 | goto out; | |
762 | ||
763 | if (addr_len==sizeof(short)) { | |
764 | err = unix_autobind(sock); | |
765 | goto out; | |
766 | } | |
767 | ||
768 | err = unix_mkname(sunaddr, addr_len, &hash); | |
769 | if (err < 0) | |
770 | goto out; | |
771 | addr_len = err; | |
772 | ||
57b47a53 | 773 | mutex_lock(&u->readlock); |
1da177e4 LT |
774 | |
775 | err = -EINVAL; | |
776 | if (u->addr) | |
777 | goto out_up; | |
778 | ||
779 | err = -ENOMEM; | |
780 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
781 | if (!addr) | |
782 | goto out_up; | |
783 | ||
784 | memcpy(addr->name, sunaddr, addr_len); | |
785 | addr->len = addr_len; | |
786 | addr->hash = hash ^ sk->sk_type; | |
787 | atomic_set(&addr->refcnt, 1); | |
788 | ||
789 | if (sunaddr->sun_path[0]) { | |
790 | unsigned int mode; | |
791 | err = 0; | |
792 | /* | |
793 | * Get the parent directory, calculate the hash for last | |
794 | * component. | |
795 | */ | |
796 | err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); | |
797 | if (err) | |
798 | goto out_mknod_parent; | |
f81a0bff CH |
799 | |
800 | dentry = lookup_create(&nd, 0); | |
1da177e4 LT |
801 | err = PTR_ERR(dentry); |
802 | if (IS_ERR(dentry)) | |
803 | goto out_mknod_unlock; | |
f81a0bff | 804 | |
1da177e4 LT |
805 | /* |
806 | * All right, let's create it. | |
807 | */ | |
808 | mode = S_IFSOCK | | |
809 | (SOCK_INODE(sock)->i_mode & ~current->fs->umask); | |
810 | err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0); | |
811 | if (err) | |
812 | goto out_mknod_dput; | |
1b1dcc1b | 813 | mutex_unlock(&nd.dentry->d_inode->i_mutex); |
1da177e4 LT |
814 | dput(nd.dentry); |
815 | nd.dentry = dentry; | |
816 | ||
817 | addr->hash = UNIX_HASH_SIZE; | |
818 | } | |
819 | ||
fbe9cc4a | 820 | spin_lock(&unix_table_lock); |
1da177e4 LT |
821 | |
822 | if (!sunaddr->sun_path[0]) { | |
823 | err = -EADDRINUSE; | |
824 | if (__unix_find_socket_byname(sunaddr, addr_len, | |
825 | sk->sk_type, hash)) { | |
826 | unix_release_addr(addr); | |
827 | goto out_unlock; | |
828 | } | |
829 | ||
830 | list = &unix_socket_table[addr->hash]; | |
831 | } else { | |
832 | list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; | |
833 | u->dentry = nd.dentry; | |
834 | u->mnt = nd.mnt; | |
835 | } | |
836 | ||
837 | err = 0; | |
838 | __unix_remove_socket(sk); | |
839 | u->addr = addr; | |
840 | __unix_insert_socket(list, sk); | |
841 | ||
842 | out_unlock: | |
fbe9cc4a | 843 | spin_unlock(&unix_table_lock); |
1da177e4 | 844 | out_up: |
57b47a53 | 845 | mutex_unlock(&u->readlock); |
1da177e4 LT |
846 | out: |
847 | return err; | |
848 | ||
849 | out_mknod_dput: | |
850 | dput(dentry); | |
851 | out_mknod_unlock: | |
1b1dcc1b | 852 | mutex_unlock(&nd.dentry->d_inode->i_mutex); |
1da177e4 LT |
853 | path_release(&nd); |
854 | out_mknod_parent: | |
855 | if (err==-EEXIST) | |
856 | err=-EADDRINUSE; | |
857 | unix_release_addr(addr); | |
858 | goto out_up; | |
859 | } | |
860 | ||
278a3de5 DM |
861 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
862 | { | |
863 | if (unlikely(sk1 == sk2) || !sk2) { | |
864 | unix_state_lock(sk1); | |
865 | return; | |
866 | } | |
867 | if (sk1 < sk2) { | |
868 | unix_state_lock(sk1); | |
869 | unix_state_lock_nested(sk2); | |
870 | } else { | |
871 | unix_state_lock(sk2); | |
872 | unix_state_lock_nested(sk1); | |
873 | } | |
874 | } | |
875 | ||
876 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
877 | { | |
878 | if (unlikely(sk1 == sk2) || !sk2) { | |
879 | unix_state_unlock(sk1); | |
880 | return; | |
881 | } | |
882 | unix_state_unlock(sk1); | |
883 | unix_state_unlock(sk2); | |
884 | } | |
885 | ||
1da177e4 LT |
886 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
887 | int alen, int flags) | |
888 | { | |
889 | struct sock *sk = sock->sk; | |
890 | struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr; | |
891 | struct sock *other; | |
892 | unsigned hash; | |
893 | int err; | |
894 | ||
895 | if (addr->sa_family != AF_UNSPEC) { | |
896 | err = unix_mkname(sunaddr, alen, &hash); | |
897 | if (err < 0) | |
898 | goto out; | |
899 | alen = err; | |
900 | ||
901 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
902 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
903 | goto out; | |
904 | ||
278a3de5 | 905 | restart: |
1da177e4 LT |
906 | other=unix_find_other(sunaddr, alen, sock->type, hash, &err); |
907 | if (!other) | |
908 | goto out; | |
909 | ||
278a3de5 DM |
910 | unix_state_double_lock(sk, other); |
911 | ||
912 | /* Apparently VFS overslept socket death. Retry. */ | |
913 | if (sock_flag(other, SOCK_DEAD)) { | |
914 | unix_state_double_unlock(sk, other); | |
915 | sock_put(other); | |
916 | goto restart; | |
917 | } | |
1da177e4 LT |
918 | |
919 | err = -EPERM; | |
920 | if (!unix_may_send(sk, other)) | |
921 | goto out_unlock; | |
922 | ||
923 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
924 | if (err) | |
925 | goto out_unlock; | |
926 | ||
927 | } else { | |
928 | /* | |
929 | * 1003.1g breaking connected state with AF_UNSPEC | |
930 | */ | |
931 | other = NULL; | |
278a3de5 | 932 | unix_state_double_lock(sk, other); |
1da177e4 LT |
933 | } |
934 | ||
935 | /* | |
936 | * If it was connected, reconnect. | |
937 | */ | |
938 | if (unix_peer(sk)) { | |
939 | struct sock *old_peer = unix_peer(sk); | |
940 | unix_peer(sk)=other; | |
278a3de5 | 941 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
942 | |
943 | if (other != old_peer) | |
944 | unix_dgram_disconnected(sk, old_peer); | |
945 | sock_put(old_peer); | |
946 | } else { | |
947 | unix_peer(sk)=other; | |
278a3de5 | 948 | unix_state_double_unlock(sk, other); |
1da177e4 | 949 | } |
ac7bfa62 | 950 | return 0; |
1da177e4 LT |
951 | |
952 | out_unlock: | |
278a3de5 | 953 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
954 | sock_put(other); |
955 | out: | |
956 | return err; | |
957 | } | |
958 | ||
959 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
960 | { | |
961 | struct unix_sock *u = unix_sk(other); | |
962 | int sched; | |
963 | DEFINE_WAIT(wait); | |
964 | ||
965 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
966 | ||
967 | sched = !sock_flag(other, SOCK_DEAD) && | |
968 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
64a14651 | 969 | (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
970 | other->sk_max_ack_backlog); |
971 | ||
1c92b4e5 | 972 | unix_state_unlock(other); |
1da177e4 LT |
973 | |
974 | if (sched) | |
975 | timeo = schedule_timeout(timeo); | |
976 | ||
977 | finish_wait(&u->peer_wait, &wait); | |
978 | return timeo; | |
979 | } | |
980 | ||
981 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
982 | int addr_len, int flags) | |
983 | { | |
984 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
985 | struct sock *sk = sock->sk; | |
986 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; | |
987 | struct sock *newsk = NULL; | |
988 | struct sock *other = NULL; | |
989 | struct sk_buff *skb = NULL; | |
990 | unsigned hash; | |
991 | int st; | |
992 | int err; | |
993 | long timeo; | |
994 | ||
995 | err = unix_mkname(sunaddr, addr_len, &hash); | |
996 | if (err < 0) | |
997 | goto out; | |
998 | addr_len = err; | |
999 | ||
1000 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
1001 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
1002 | goto out; | |
1003 | ||
1004 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1005 | ||
1006 | /* First of all allocate resources. | |
1007 | If we will make it after state is locked, | |
1008 | we will have to recheck all again in any case. | |
1009 | */ | |
1010 | ||
1011 | err = -ENOMEM; | |
1012 | ||
1013 | /* create new sock for complete connection */ | |
1014 | newsk = unix_create1(NULL); | |
1015 | if (newsk == NULL) | |
1016 | goto out; | |
1017 | ||
1018 | /* Allocate skb for sending to listening sock */ | |
1019 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1020 | if (skb == NULL) | |
1021 | goto out; | |
1022 | ||
1023 | restart: | |
1024 | /* Find listening sock. */ | |
1025 | other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err); | |
1026 | if (!other) | |
1027 | goto out; | |
1028 | ||
1029 | /* Latch state of peer */ | |
1c92b4e5 | 1030 | unix_state_lock(other); |
1da177e4 LT |
1031 | |
1032 | /* Apparently VFS overslept socket death. Retry. */ | |
1033 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1034 | unix_state_unlock(other); |
1da177e4 LT |
1035 | sock_put(other); |
1036 | goto restart; | |
1037 | } | |
1038 | ||
1039 | err = -ECONNREFUSED; | |
1040 | if (other->sk_state != TCP_LISTEN) | |
1041 | goto out_unlock; | |
1042 | ||
64a14651 | 1043 | if (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
1044 | other->sk_max_ack_backlog) { |
1045 | err = -EAGAIN; | |
1046 | if (!timeo) | |
1047 | goto out_unlock; | |
1048 | ||
1049 | timeo = unix_wait_for_peer(other, timeo); | |
1050 | ||
1051 | err = sock_intr_errno(timeo); | |
1052 | if (signal_pending(current)) | |
1053 | goto out; | |
1054 | sock_put(other); | |
1055 | goto restart; | |
ac7bfa62 | 1056 | } |
1da177e4 LT |
1057 | |
1058 | /* Latch our state. | |
1059 | ||
1060 | It is tricky place. We need to grab write lock and cannot | |
1061 | drop lock on peer. It is dangerous because deadlock is | |
1062 | possible. Connect to self case and simultaneous | |
1063 | attempt to connect are eliminated by checking socket | |
1064 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1065 | check this before attempt to grab lock. | |
1066 | ||
1067 | Well, and we have to recheck the state after socket locked. | |
1068 | */ | |
1069 | st = sk->sk_state; | |
1070 | ||
1071 | switch (st) { | |
1072 | case TCP_CLOSE: | |
1073 | /* This is ok... continue with connect */ | |
1074 | break; | |
1075 | case TCP_ESTABLISHED: | |
1076 | /* Socket is already connected */ | |
1077 | err = -EISCONN; | |
1078 | goto out_unlock; | |
1079 | default: | |
1080 | err = -EINVAL; | |
1081 | goto out_unlock; | |
1082 | } | |
1083 | ||
1c92b4e5 | 1084 | unix_state_lock_nested(sk); |
1da177e4 LT |
1085 | |
1086 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1087 | unix_state_unlock(sk); |
1088 | unix_state_unlock(other); | |
1da177e4 LT |
1089 | sock_put(other); |
1090 | goto restart; | |
1091 | } | |
1092 | ||
1093 | err = security_unix_stream_connect(sock, other->sk_socket, newsk); | |
1094 | if (err) { | |
1c92b4e5 | 1095 | unix_state_unlock(sk); |
1da177e4 LT |
1096 | goto out_unlock; |
1097 | } | |
1098 | ||
1099 | /* The way is open! Fastly set all the necessary fields... */ | |
1100 | ||
1101 | sock_hold(sk); | |
1102 | unix_peer(newsk) = sk; | |
1103 | newsk->sk_state = TCP_ESTABLISHED; | |
1104 | newsk->sk_type = sk->sk_type; | |
1105 | newsk->sk_peercred.pid = current->tgid; | |
1106 | newsk->sk_peercred.uid = current->euid; | |
1107 | newsk->sk_peercred.gid = current->egid; | |
1108 | newu = unix_sk(newsk); | |
1109 | newsk->sk_sleep = &newu->peer_wait; | |
1110 | otheru = unix_sk(other); | |
1111 | ||
1112 | /* copy address information from listening to new sock*/ | |
1113 | if (otheru->addr) { | |
1114 | atomic_inc(&otheru->addr->refcnt); | |
1115 | newu->addr = otheru->addr; | |
1116 | } | |
1117 | if (otheru->dentry) { | |
1118 | newu->dentry = dget(otheru->dentry); | |
1119 | newu->mnt = mntget(otheru->mnt); | |
1120 | } | |
1121 | ||
1122 | /* Set credentials */ | |
1123 | sk->sk_peercred = other->sk_peercred; | |
1124 | ||
1da177e4 LT |
1125 | sock->state = SS_CONNECTED; |
1126 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1127 | sock_hold(newsk); |
1128 | ||
1129 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1130 | unix_peer(sk) = newsk; | |
1da177e4 | 1131 | |
1c92b4e5 | 1132 | unix_state_unlock(sk); |
1da177e4 LT |
1133 | |
1134 | /* take ten and and send info to listening sock */ | |
1135 | spin_lock(&other->sk_receive_queue.lock); | |
1136 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1137 | /* Undo artificially decreased inflight after embrion | |
1138 | * is installed to listening socket. */ | |
1139 | atomic_inc(&newu->inflight); | |
1140 | spin_unlock(&other->sk_receive_queue.lock); | |
1c92b4e5 | 1141 | unix_state_unlock(other); |
1da177e4 LT |
1142 | other->sk_data_ready(other, 0); |
1143 | sock_put(other); | |
1144 | return 0; | |
1145 | ||
1146 | out_unlock: | |
1147 | if (other) | |
1c92b4e5 | 1148 | unix_state_unlock(other); |
1da177e4 LT |
1149 | |
1150 | out: | |
1151 | if (skb) | |
1152 | kfree_skb(skb); | |
1153 | if (newsk) | |
1154 | unix_release_sock(newsk, 0); | |
1155 | if (other) | |
1156 | sock_put(other); | |
1157 | return err; | |
1158 | } | |
1159 | ||
1160 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1161 | { | |
1162 | struct sock *ska=socka->sk, *skb = sockb->sk; | |
1163 | ||
1164 | /* Join our sockets back to back */ | |
1165 | sock_hold(ska); | |
1166 | sock_hold(skb); | |
1167 | unix_peer(ska)=skb; | |
1168 | unix_peer(skb)=ska; | |
1169 | ska->sk_peercred.pid = skb->sk_peercred.pid = current->tgid; | |
1170 | ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid; | |
1171 | ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid; | |
1172 | ||
1173 | if (ska->sk_type != SOCK_DGRAM) { | |
1174 | ska->sk_state = TCP_ESTABLISHED; | |
1175 | skb->sk_state = TCP_ESTABLISHED; | |
1176 | socka->state = SS_CONNECTED; | |
1177 | sockb->state = SS_CONNECTED; | |
1178 | } | |
1179 | return 0; | |
1180 | } | |
1181 | ||
1182 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) | |
1183 | { | |
1184 | struct sock *sk = sock->sk; | |
1185 | struct sock *tsk; | |
1186 | struct sk_buff *skb; | |
1187 | int err; | |
1188 | ||
1189 | err = -EOPNOTSUPP; | |
1190 | if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) | |
1191 | goto out; | |
1192 | ||
1193 | err = -EINVAL; | |
1194 | if (sk->sk_state != TCP_LISTEN) | |
1195 | goto out; | |
1196 | ||
1197 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1198 | * so that no locks are necessary. | |
1199 | */ | |
1200 | ||
1201 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1202 | if (!skb) { | |
1203 | /* This means receive shutdown. */ | |
1204 | if (err == 0) | |
1205 | err = -EINVAL; | |
1206 | goto out; | |
1207 | } | |
1208 | ||
1209 | tsk = skb->sk; | |
1210 | skb_free_datagram(sk, skb); | |
1211 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1212 | ||
1213 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1214 | unix_state_lock(tsk); |
1da177e4 LT |
1215 | newsock->state = SS_CONNECTED; |
1216 | sock_graft(tsk, newsock); | |
1c92b4e5 | 1217 | unix_state_unlock(tsk); |
1da177e4 LT |
1218 | return 0; |
1219 | ||
1220 | out: | |
1221 | return err; | |
1222 | } | |
1223 | ||
1224 | ||
1225 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1226 | { | |
1227 | struct sock *sk = sock->sk; | |
1228 | struct unix_sock *u; | |
1229 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
1230 | int err = 0; | |
1231 | ||
1232 | if (peer) { | |
1233 | sk = unix_peer_get(sk); | |
1234 | ||
1235 | err = -ENOTCONN; | |
1236 | if (!sk) | |
1237 | goto out; | |
1238 | err = 0; | |
1239 | } else { | |
1240 | sock_hold(sk); | |
1241 | } | |
1242 | ||
1243 | u = unix_sk(sk); | |
1c92b4e5 | 1244 | unix_state_lock(sk); |
1da177e4 LT |
1245 | if (!u->addr) { |
1246 | sunaddr->sun_family = AF_UNIX; | |
1247 | sunaddr->sun_path[0] = 0; | |
1248 | *uaddr_len = sizeof(short); | |
1249 | } else { | |
1250 | struct unix_address *addr = u->addr; | |
1251 | ||
1252 | *uaddr_len = addr->len; | |
1253 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1254 | } | |
1c92b4e5 | 1255 | unix_state_unlock(sk); |
1da177e4 LT |
1256 | sock_put(sk); |
1257 | out: | |
1258 | return err; | |
1259 | } | |
1260 | ||
1261 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1262 | { | |
1263 | int i; | |
1264 | ||
1265 | scm->fp = UNIXCB(skb).fp; | |
1266 | skb->destructor = sock_wfree; | |
1267 | UNIXCB(skb).fp = NULL; | |
1268 | ||
1269 | for (i=scm->fp->count-1; i>=0; i--) | |
1270 | unix_notinflight(scm->fp->fp[i]); | |
1271 | } | |
1272 | ||
1273 | static void unix_destruct_fds(struct sk_buff *skb) | |
1274 | { | |
1275 | struct scm_cookie scm; | |
1276 | memset(&scm, 0, sizeof(scm)); | |
1277 | unix_detach_fds(&scm, skb); | |
1278 | ||
1279 | /* Alas, it calls VFS */ | |
1280 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1281 | scm_destroy(&scm); | |
1282 | sock_wfree(skb); | |
1283 | } | |
1284 | ||
1285 | static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1286 | { | |
1287 | int i; | |
1288 | for (i=scm->fp->count-1; i>=0; i--) | |
1289 | unix_inflight(scm->fp->fp[i]); | |
1290 | UNIXCB(skb).fp = scm->fp; | |
1291 | skb->destructor = unix_destruct_fds; | |
1292 | scm->fp = NULL; | |
1293 | } | |
1294 | ||
1295 | /* | |
1296 | * Send AF_UNIX data. | |
1297 | */ | |
1298 | ||
1299 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1300 | struct msghdr *msg, size_t len) | |
1301 | { | |
1302 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1303 | struct sock *sk = sock->sk; | |
1304 | struct unix_sock *u = unix_sk(sk); | |
1305 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1306 | struct sock *other = NULL; | |
1307 | int namelen = 0; /* fake GCC */ | |
1308 | int err; | |
1309 | unsigned hash; | |
1310 | struct sk_buff *skb; | |
1311 | long timeo; | |
1312 | struct scm_cookie tmp_scm; | |
1313 | ||
1314 | if (NULL == siocb->scm) | |
1315 | siocb->scm = &tmp_scm; | |
1316 | err = scm_send(sock, msg, siocb->scm); | |
1317 | if (err < 0) | |
1318 | return err; | |
1319 | ||
1320 | err = -EOPNOTSUPP; | |
1321 | if (msg->msg_flags&MSG_OOB) | |
1322 | goto out; | |
1323 | ||
1324 | if (msg->msg_namelen) { | |
1325 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1326 | if (err < 0) | |
1327 | goto out; | |
1328 | namelen = err; | |
1329 | } else { | |
1330 | sunaddr = NULL; | |
1331 | err = -ENOTCONN; | |
1332 | other = unix_peer_get(sk); | |
1333 | if (!other) | |
1334 | goto out; | |
1335 | } | |
1336 | ||
1337 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
1338 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
1339 | goto out; | |
1340 | ||
1341 | err = -EMSGSIZE; | |
1342 | if (len > sk->sk_sndbuf - 32) | |
1343 | goto out; | |
1344 | ||
1345 | skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); | |
1346 | if (skb==NULL) | |
1347 | goto out; | |
1348 | ||
1349 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1350 | if (siocb->scm->fp) | |
1351 | unix_attach_fds(siocb->scm, skb); | |
dc49c1f9 | 1352 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1353 | |
badff6d0 | 1354 | skb_reset_transport_header(skb); |
1da177e4 LT |
1355 | err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); |
1356 | if (err) | |
1357 | goto out_free; | |
1358 | ||
1359 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1360 | ||
1361 | restart: | |
1362 | if (!other) { | |
1363 | err = -ECONNRESET; | |
1364 | if (sunaddr == NULL) | |
1365 | goto out_free; | |
1366 | ||
1367 | other = unix_find_other(sunaddr, namelen, sk->sk_type, | |
1368 | hash, &err); | |
1369 | if (other==NULL) | |
1370 | goto out_free; | |
1371 | } | |
1372 | ||
1c92b4e5 | 1373 | unix_state_lock(other); |
1da177e4 LT |
1374 | err = -EPERM; |
1375 | if (!unix_may_send(sk, other)) | |
1376 | goto out_unlock; | |
1377 | ||
1378 | if (sock_flag(other, SOCK_DEAD)) { | |
1379 | /* | |
1380 | * Check with 1003.1g - what should | |
1381 | * datagram error | |
1382 | */ | |
1c92b4e5 | 1383 | unix_state_unlock(other); |
1da177e4 LT |
1384 | sock_put(other); |
1385 | ||
1386 | err = 0; | |
1c92b4e5 | 1387 | unix_state_lock(sk); |
1da177e4 LT |
1388 | if (unix_peer(sk) == other) { |
1389 | unix_peer(sk)=NULL; | |
1c92b4e5 | 1390 | unix_state_unlock(sk); |
1da177e4 LT |
1391 | |
1392 | unix_dgram_disconnected(sk, other); | |
1393 | sock_put(other); | |
1394 | err = -ECONNREFUSED; | |
1395 | } else { | |
1c92b4e5 | 1396 | unix_state_unlock(sk); |
1da177e4 LT |
1397 | } |
1398 | ||
1399 | other = NULL; | |
1400 | if (err) | |
1401 | goto out_free; | |
1402 | goto restart; | |
1403 | } | |
1404 | ||
1405 | err = -EPIPE; | |
1406 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1407 | goto out_unlock; | |
1408 | ||
1409 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1410 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1411 | if (err) | |
1412 | goto out_unlock; | |
1413 | } | |
1414 | ||
1415 | if (unix_peer(other) != sk && | |
64a14651 | 1416 | (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
1417 | other->sk_max_ack_backlog)) { |
1418 | if (!timeo) { | |
1419 | err = -EAGAIN; | |
1420 | goto out_unlock; | |
1421 | } | |
1422 | ||
1423 | timeo = unix_wait_for_peer(other, timeo); | |
1424 | ||
1425 | err = sock_intr_errno(timeo); | |
1426 | if (signal_pending(current)) | |
1427 | goto out_free; | |
1428 | ||
1429 | goto restart; | |
1430 | } | |
1431 | ||
1432 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1c92b4e5 | 1433 | unix_state_unlock(other); |
1da177e4 LT |
1434 | other->sk_data_ready(other, len); |
1435 | sock_put(other); | |
1436 | scm_destroy(siocb->scm); | |
1437 | return len; | |
1438 | ||
1439 | out_unlock: | |
1c92b4e5 | 1440 | unix_state_unlock(other); |
1da177e4 LT |
1441 | out_free: |
1442 | kfree_skb(skb); | |
1443 | out: | |
1444 | if (other) | |
1445 | sock_put(other); | |
1446 | scm_destroy(siocb->scm); | |
1447 | return err; | |
1448 | } | |
1449 | ||
ac7bfa62 | 1450 | |
1da177e4 LT |
1451 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1452 | struct msghdr *msg, size_t len) | |
1453 | { | |
1454 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1455 | struct sock *sk = sock->sk; | |
1456 | struct sock *other = NULL; | |
1457 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1458 | int err,size; | |
1459 | struct sk_buff *skb; | |
1460 | int sent=0; | |
1461 | struct scm_cookie tmp_scm; | |
1462 | ||
1463 | if (NULL == siocb->scm) | |
1464 | siocb->scm = &tmp_scm; | |
1465 | err = scm_send(sock, msg, siocb->scm); | |
1466 | if (err < 0) | |
1467 | return err; | |
1468 | ||
1469 | err = -EOPNOTSUPP; | |
1470 | if (msg->msg_flags&MSG_OOB) | |
1471 | goto out_err; | |
1472 | ||
1473 | if (msg->msg_namelen) { | |
1474 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1475 | goto out_err; | |
1476 | } else { | |
1477 | sunaddr = NULL; | |
1478 | err = -ENOTCONN; | |
830a1e5c | 1479 | other = unix_peer(sk); |
1da177e4 LT |
1480 | if (!other) |
1481 | goto out_err; | |
1482 | } | |
1483 | ||
1484 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1485 | goto pipe_err; | |
1486 | ||
1487 | while(sent < len) | |
1488 | { | |
1489 | /* | |
e9df7d7f BL |
1490 | * Optimisation for the fact that under 0.01% of X |
1491 | * messages typically need breaking up. | |
1da177e4 LT |
1492 | */ |
1493 | ||
e9df7d7f | 1494 | size = len-sent; |
1da177e4 LT |
1495 | |
1496 | /* Keep two messages in the pipe so it schedules better */ | |
e9df7d7f BL |
1497 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
1498 | size = (sk->sk_sndbuf >> 1) - 64; | |
1da177e4 LT |
1499 | |
1500 | if (size > SKB_MAX_ALLOC) | |
1501 | size = SKB_MAX_ALLOC; | |
ac7bfa62 | 1502 | |
1da177e4 LT |
1503 | /* |
1504 | * Grab a buffer | |
1505 | */ | |
ac7bfa62 | 1506 | |
1da177e4 LT |
1507 | skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); |
1508 | ||
1509 | if (skb==NULL) | |
1510 | goto out_err; | |
1511 | ||
1512 | /* | |
1513 | * If you pass two values to the sock_alloc_send_skb | |
1514 | * it tries to grab the large buffer with GFP_NOFS | |
1515 | * (which can fail easily), and if it fails grab the | |
1516 | * fallback size buffer which is under a page and will | |
1517 | * succeed. [Alan] | |
1518 | */ | |
1519 | size = min_t(int, size, skb_tailroom(skb)); | |
1520 | ||
1521 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1522 | if (siocb->scm->fp) | |
1523 | unix_attach_fds(siocb->scm, skb); | |
1524 | ||
1525 | if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { | |
1526 | kfree_skb(skb); | |
1527 | goto out_err; | |
1528 | } | |
1529 | ||
1c92b4e5 | 1530 | unix_state_lock(other); |
1da177e4 LT |
1531 | |
1532 | if (sock_flag(other, SOCK_DEAD) || | |
1533 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1534 | goto pipe_err_free; | |
1535 | ||
1536 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1c92b4e5 | 1537 | unix_state_unlock(other); |
1da177e4 LT |
1538 | other->sk_data_ready(other, size); |
1539 | sent+=size; | |
1540 | } | |
1da177e4 LT |
1541 | |
1542 | scm_destroy(siocb->scm); | |
1543 | siocb->scm = NULL; | |
1544 | ||
1545 | return sent; | |
1546 | ||
1547 | pipe_err_free: | |
1c92b4e5 | 1548 | unix_state_unlock(other); |
1da177e4 LT |
1549 | kfree_skb(skb); |
1550 | pipe_err: | |
1551 | if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) | |
1552 | send_sig(SIGPIPE,current,0); | |
1553 | err = -EPIPE; | |
1554 | out_err: | |
1da177e4 LT |
1555 | scm_destroy(siocb->scm); |
1556 | siocb->scm = NULL; | |
1557 | return sent ? : err; | |
1558 | } | |
1559 | ||
1560 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1561 | struct msghdr *msg, size_t len) | |
1562 | { | |
1563 | int err; | |
1564 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1565 | |
1da177e4 LT |
1566 | err = sock_error(sk); |
1567 | if (err) | |
1568 | return err; | |
1569 | ||
1570 | if (sk->sk_state != TCP_ESTABLISHED) | |
1571 | return -ENOTCONN; | |
1572 | ||
1573 | if (msg->msg_namelen) | |
1574 | msg->msg_namelen = 0; | |
1575 | ||
1576 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1577 | } | |
ac7bfa62 | 1578 | |
1da177e4 LT |
1579 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1580 | { | |
1581 | struct unix_sock *u = unix_sk(sk); | |
1582 | ||
1583 | msg->msg_namelen = 0; | |
1584 | if (u->addr) { | |
1585 | msg->msg_namelen = u->addr->len; | |
1586 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1591 | struct msghdr *msg, size_t size, | |
1592 | int flags) | |
1593 | { | |
1594 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1595 | struct scm_cookie tmp_scm; | |
1596 | struct sock *sk = sock->sk; | |
1597 | struct unix_sock *u = unix_sk(sk); | |
1598 | int noblock = flags & MSG_DONTWAIT; | |
1599 | struct sk_buff *skb; | |
1600 | int err; | |
1601 | ||
1602 | err = -EOPNOTSUPP; | |
1603 | if (flags&MSG_OOB) | |
1604 | goto out; | |
1605 | ||
1606 | msg->msg_namelen = 0; | |
1607 | ||
57b47a53 | 1608 | mutex_lock(&u->readlock); |
1da177e4 LT |
1609 | |
1610 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
1611 | if (!skb) | |
1612 | goto out_unlock; | |
1613 | ||
1614 | wake_up_interruptible(&u->peer_wait); | |
1615 | ||
1616 | if (msg->msg_name) | |
1617 | unix_copy_addr(msg, skb->sk); | |
1618 | ||
1619 | if (size > skb->len) | |
1620 | size = skb->len; | |
1621 | else if (size < skb->len) | |
1622 | msg->msg_flags |= MSG_TRUNC; | |
1623 | ||
1624 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); | |
1625 | if (err) | |
1626 | goto out_free; | |
1627 | ||
1628 | if (!siocb->scm) { | |
1629 | siocb->scm = &tmp_scm; | |
1630 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1631 | } | |
1632 | siocb->scm->creds = *UNIXCREDS(skb); | |
877ce7c1 | 1633 | unix_set_secdata(siocb->scm, skb); |
1da177e4 LT |
1634 | |
1635 | if (!(flags & MSG_PEEK)) | |
1636 | { | |
1637 | if (UNIXCB(skb).fp) | |
1638 | unix_detach_fds(siocb->scm, skb); | |
1639 | } | |
ac7bfa62 | 1640 | else |
1da177e4 LT |
1641 | { |
1642 | /* It is questionable: on PEEK we could: | |
1643 | - do not return fds - good, but too simple 8) | |
1644 | - return fds, and do not return them on read (old strategy, | |
1645 | apparently wrong) | |
1646 | - clone fds (I chose it for now, it is the most universal | |
1647 | solution) | |
ac7bfa62 YH |
1648 | |
1649 | POSIX 1003.1g does not actually define this clearly | |
1650 | at all. POSIX 1003.1g doesn't define a lot of things | |
1651 | clearly however! | |
1652 | ||
1da177e4 LT |
1653 | */ |
1654 | if (UNIXCB(skb).fp) | |
1655 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1656 | } | |
1657 | err = size; | |
1658 | ||
1659 | scm_recv(sock, msg, siocb->scm, flags); | |
1660 | ||
1661 | out_free: | |
1662 | skb_free_datagram(sk,skb); | |
1663 | out_unlock: | |
57b47a53 | 1664 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1665 | out: |
1666 | return err; | |
1667 | } | |
1668 | ||
1669 | /* | |
1670 | * Sleep until data has arrive. But check for races.. | |
1671 | */ | |
ac7bfa62 | 1672 | |
1da177e4 LT |
1673 | static long unix_stream_data_wait(struct sock * sk, long timeo) |
1674 | { | |
1675 | DEFINE_WAIT(wait); | |
1676 | ||
1c92b4e5 | 1677 | unix_state_lock(sk); |
1da177e4 LT |
1678 | |
1679 | for (;;) { | |
1680 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
1681 | ||
b03efcfb | 1682 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
1da177e4 LT |
1683 | sk->sk_err || |
1684 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1685 | signal_pending(current) || | |
1686 | !timeo) | |
1687 | break; | |
1688 | ||
1689 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1690 | unix_state_unlock(sk); |
1da177e4 | 1691 | timeo = schedule_timeout(timeo); |
1c92b4e5 | 1692 | unix_state_lock(sk); |
1da177e4 LT |
1693 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1694 | } | |
1695 | ||
1696 | finish_wait(sk->sk_sleep, &wait); | |
1c92b4e5 | 1697 | unix_state_unlock(sk); |
1da177e4 LT |
1698 | return timeo; |
1699 | } | |
1700 | ||
1701 | ||
1702 | ||
1703 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1704 | struct msghdr *msg, size_t size, | |
1705 | int flags) | |
1706 | { | |
1707 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1708 | struct scm_cookie tmp_scm; | |
1709 | struct sock *sk = sock->sk; | |
1710 | struct unix_sock *u = unix_sk(sk); | |
1711 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1712 | int copied = 0; | |
1713 | int check_creds = 0; | |
1714 | int target; | |
1715 | int err = 0; | |
1716 | long timeo; | |
1717 | ||
1718 | err = -EINVAL; | |
1719 | if (sk->sk_state != TCP_ESTABLISHED) | |
1720 | goto out; | |
1721 | ||
1722 | err = -EOPNOTSUPP; | |
1723 | if (flags&MSG_OOB) | |
1724 | goto out; | |
1725 | ||
1726 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1727 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1728 | ||
1729 | msg->msg_namelen = 0; | |
1730 | ||
1731 | /* Lock the socket to prevent queue disordering | |
1732 | * while sleeps in memcpy_tomsg | |
1733 | */ | |
1734 | ||
1735 | if (!siocb->scm) { | |
1736 | siocb->scm = &tmp_scm; | |
1737 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1738 | } | |
1739 | ||
57b47a53 | 1740 | mutex_lock(&u->readlock); |
1da177e4 LT |
1741 | |
1742 | do | |
1743 | { | |
1744 | int chunk; | |
1745 | struct sk_buff *skb; | |
1746 | ||
3c0d2f37 | 1747 | unix_state_lock(sk); |
1da177e4 LT |
1748 | skb = skb_dequeue(&sk->sk_receive_queue); |
1749 | if (skb==NULL) | |
1750 | { | |
1751 | if (copied >= target) | |
3c0d2f37 | 1752 | goto unlock; |
1da177e4 LT |
1753 | |
1754 | /* | |
1755 | * POSIX 1003.1g mandates this order. | |
1756 | */ | |
ac7bfa62 | 1757 | |
1da177e4 | 1758 | if ((err = sock_error(sk)) != 0) |
3c0d2f37 | 1759 | goto unlock; |
1da177e4 | 1760 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1761 | goto unlock; |
1762 | ||
1763 | unix_state_unlock(sk); | |
1da177e4 LT |
1764 | err = -EAGAIN; |
1765 | if (!timeo) | |
1766 | break; | |
57b47a53 | 1767 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1768 | |
1769 | timeo = unix_stream_data_wait(sk, timeo); | |
1770 | ||
1771 | if (signal_pending(current)) { | |
1772 | err = sock_intr_errno(timeo); | |
1773 | goto out; | |
1774 | } | |
57b47a53 | 1775 | mutex_lock(&u->readlock); |
1da177e4 | 1776 | continue; |
3c0d2f37 MS |
1777 | unlock: |
1778 | unix_state_unlock(sk); | |
1779 | break; | |
1da177e4 | 1780 | } |
3c0d2f37 | 1781 | unix_state_unlock(sk); |
1da177e4 LT |
1782 | |
1783 | if (check_creds) { | |
1784 | /* Never glue messages from different writers */ | |
1785 | if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { | |
1786 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1787 | break; | |
1788 | } | |
1789 | } else { | |
1790 | /* Copy credentials */ | |
1791 | siocb->scm->creds = *UNIXCREDS(skb); | |
1792 | check_creds = 1; | |
1793 | } | |
1794 | ||
1795 | /* Copy address just once */ | |
1796 | if (sunaddr) | |
1797 | { | |
1798 | unix_copy_addr(msg, skb->sk); | |
1799 | sunaddr = NULL; | |
1800 | } | |
1801 | ||
1802 | chunk = min_t(unsigned int, skb->len, size); | |
1803 | if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { | |
1804 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1805 | if (copied == 0) | |
1806 | copied = -EFAULT; | |
1807 | break; | |
1808 | } | |
1809 | copied += chunk; | |
1810 | size -= chunk; | |
1811 | ||
1812 | /* Mark read part of skb as used */ | |
1813 | if (!(flags & MSG_PEEK)) | |
1814 | { | |
1815 | skb_pull(skb, chunk); | |
1816 | ||
1817 | if (UNIXCB(skb).fp) | |
1818 | unix_detach_fds(siocb->scm, skb); | |
1819 | ||
1820 | /* put the skb back if we didn't use it up.. */ | |
1821 | if (skb->len) | |
1822 | { | |
1823 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1824 | break; | |
1825 | } | |
1826 | ||
1827 | kfree_skb(skb); | |
1828 | ||
1829 | if (siocb->scm->fp) | |
1830 | break; | |
1831 | } | |
1832 | else | |
1833 | { | |
1834 | /* It is questionable, see note in unix_dgram_recvmsg. | |
1835 | */ | |
1836 | if (UNIXCB(skb).fp) | |
1837 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1838 | ||
1839 | /* put message back and return */ | |
1840 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1841 | break; | |
1842 | } | |
1843 | } while (size); | |
1844 | ||
57b47a53 | 1845 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1846 | scm_recv(sock, msg, siocb->scm, flags); |
1847 | out: | |
1848 | return copied ? : err; | |
1849 | } | |
1850 | ||
1851 | static int unix_shutdown(struct socket *sock, int mode) | |
1852 | { | |
1853 | struct sock *sk = sock->sk; | |
1854 | struct sock *other; | |
1855 | ||
1856 | mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); | |
1857 | ||
1858 | if (mode) { | |
1c92b4e5 | 1859 | unix_state_lock(sk); |
1da177e4 LT |
1860 | sk->sk_shutdown |= mode; |
1861 | other=unix_peer(sk); | |
1862 | if (other) | |
1863 | sock_hold(other); | |
1c92b4e5 | 1864 | unix_state_unlock(sk); |
1da177e4 LT |
1865 | sk->sk_state_change(sk); |
1866 | ||
1867 | if (other && | |
1868 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
1869 | ||
1870 | int peer_mode = 0; | |
1871 | ||
1872 | if (mode&RCV_SHUTDOWN) | |
1873 | peer_mode |= SEND_SHUTDOWN; | |
1874 | if (mode&SEND_SHUTDOWN) | |
1875 | peer_mode |= RCV_SHUTDOWN; | |
1c92b4e5 | 1876 | unix_state_lock(other); |
1da177e4 | 1877 | other->sk_shutdown |= peer_mode; |
1c92b4e5 | 1878 | unix_state_unlock(other); |
1da177e4 LT |
1879 | other->sk_state_change(other); |
1880 | read_lock(&other->sk_callback_lock); | |
1881 | if (peer_mode == SHUTDOWN_MASK) | |
1882 | sk_wake_async(other,1,POLL_HUP); | |
1883 | else if (peer_mode & RCV_SHUTDOWN) | |
1884 | sk_wake_async(other,1,POLL_IN); | |
1885 | read_unlock(&other->sk_callback_lock); | |
1886 | } | |
1887 | if (other) | |
1888 | sock_put(other); | |
1889 | } | |
1890 | return 0; | |
1891 | } | |
1892 | ||
1893 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1894 | { | |
1895 | struct sock *sk = sock->sk; | |
1896 | long amount=0; | |
1897 | int err; | |
1898 | ||
1899 | switch(cmd) | |
1900 | { | |
1901 | case SIOCOUTQ: | |
1902 | amount = atomic_read(&sk->sk_wmem_alloc); | |
1903 | err = put_user(amount, (int __user *)arg); | |
1904 | break; | |
1905 | case SIOCINQ: | |
1906 | { | |
1907 | struct sk_buff *skb; | |
1908 | ||
1909 | if (sk->sk_state == TCP_LISTEN) { | |
1910 | err = -EINVAL; | |
1911 | break; | |
1912 | } | |
1913 | ||
1914 | spin_lock(&sk->sk_receive_queue.lock); | |
1915 | if (sk->sk_type == SOCK_STREAM || | |
1916 | sk->sk_type == SOCK_SEQPACKET) { | |
1917 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
1918 | amount += skb->len; | |
1919 | } else { | |
1920 | skb = skb_peek(&sk->sk_receive_queue); | |
1921 | if (skb) | |
1922 | amount=skb->len; | |
1923 | } | |
1924 | spin_unlock(&sk->sk_receive_queue.lock); | |
1925 | err = put_user(amount, (int __user *)arg); | |
1926 | break; | |
1927 | } | |
1928 | ||
1929 | default: | |
b5e5fa5e | 1930 | err = -ENOIOCTLCMD; |
1da177e4 LT |
1931 | break; |
1932 | } | |
1933 | return err; | |
1934 | } | |
1935 | ||
1936 | static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) | |
1937 | { | |
1938 | struct sock *sk = sock->sk; | |
1939 | unsigned int mask; | |
1940 | ||
1941 | poll_wait(file, sk->sk_sleep, wait); | |
1942 | mask = 0; | |
1943 | ||
1944 | /* exceptional events? */ | |
1945 | if (sk->sk_err) | |
1946 | mask |= POLLERR; | |
1947 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
1948 | mask |= POLLHUP; | |
f348d70a DL |
1949 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
1950 | mask |= POLLRDHUP; | |
1da177e4 LT |
1951 | |
1952 | /* readable? */ | |
1953 | if (!skb_queue_empty(&sk->sk_receive_queue) || | |
1954 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1955 | mask |= POLLIN | POLLRDNORM; | |
1956 | ||
1957 | /* Connection-based need to check for termination and startup */ | |
1958 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) | |
1959 | mask |= POLLHUP; | |
1960 | ||
1961 | /* | |
1962 | * we set writable also when the other side has shut down the | |
1963 | * connection. This prevents stuck sockets. | |
1964 | */ | |
1965 | if (unix_writable(sk)) | |
1966 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
1967 | ||
1968 | return mask; | |
1969 | } | |
1970 | ||
1971 | ||
1972 | #ifdef CONFIG_PROC_FS | |
1973 | static struct sock *unix_seq_idx(int *iter, loff_t pos) | |
1974 | { | |
1975 | loff_t off = 0; | |
1976 | struct sock *s; | |
1977 | ||
1978 | for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) { | |
ac7bfa62 | 1979 | if (off == pos) |
1da177e4 LT |
1980 | return s; |
1981 | ++off; | |
1982 | } | |
1983 | return NULL; | |
1984 | } | |
1985 | ||
1986 | ||
1987 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) | |
1988 | { | |
fbe9cc4a | 1989 | spin_lock(&unix_table_lock); |
1da177e4 LT |
1990 | return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1); |
1991 | } | |
1992 | ||
1993 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1994 | { | |
1995 | ++*pos; | |
1996 | ||
ac7bfa62 | 1997 | if (v == (void *)1) |
1da177e4 LT |
1998 | return first_unix_socket(seq->private); |
1999 | return next_unix_socket(seq->private, v); | |
2000 | } | |
2001 | ||
2002 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
2003 | { | |
fbe9cc4a | 2004 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2005 | } |
2006 | ||
2007 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2008 | { | |
ac7bfa62 | 2009 | |
1da177e4 LT |
2010 | if (v == (void *)1) |
2011 | seq_puts(seq, "Num RefCount Protocol Flags Type St " | |
2012 | "Inode Path\n"); | |
2013 | else { | |
2014 | struct sock *s = v; | |
2015 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2016 | unix_state_lock(s); |
1da177e4 LT |
2017 | |
2018 | seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", | |
2019 | s, | |
2020 | atomic_read(&s->sk_refcnt), | |
2021 | 0, | |
2022 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2023 | s->sk_type, | |
2024 | s->sk_socket ? | |
2025 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2026 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2027 | sock_i_ino(s)); | |
2028 | ||
2029 | if (u->addr) { | |
2030 | int i, len; | |
2031 | seq_putc(seq, ' '); | |
2032 | ||
2033 | i = 0; | |
2034 | len = u->addr->len - sizeof(short); | |
2035 | if (!UNIX_ABSTRACT(s)) | |
2036 | len--; | |
2037 | else { | |
2038 | seq_putc(seq, '@'); | |
2039 | i++; | |
2040 | } | |
2041 | for ( ; i < len; i++) | |
2042 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2043 | } | |
1c92b4e5 | 2044 | unix_state_unlock(s); |
1da177e4 LT |
2045 | seq_putc(seq, '\n'); |
2046 | } | |
2047 | ||
2048 | return 0; | |
2049 | } | |
2050 | ||
56b3d975 | 2051 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2052 | .start = unix_seq_start, |
2053 | .next = unix_seq_next, | |
2054 | .stop = unix_seq_stop, | |
2055 | .show = unix_seq_show, | |
2056 | }; | |
2057 | ||
2058 | ||
2059 | static int unix_seq_open(struct inode *inode, struct file *file) | |
2060 | { | |
2061 | struct seq_file *seq; | |
2062 | int rc = -ENOMEM; | |
2063 | int *iter = kmalloc(sizeof(int), GFP_KERNEL); | |
2064 | ||
2065 | if (!iter) | |
2066 | goto out; | |
2067 | ||
2068 | rc = seq_open(file, &unix_seq_ops); | |
2069 | if (rc) | |
2070 | goto out_kfree; | |
2071 | ||
2072 | seq = file->private_data; | |
2073 | seq->private = iter; | |
2074 | *iter = 0; | |
2075 | out: | |
2076 | return rc; | |
2077 | out_kfree: | |
2078 | kfree(iter); | |
2079 | goto out; | |
2080 | } | |
2081 | ||
da7071d7 | 2082 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2083 | .owner = THIS_MODULE, |
2084 | .open = unix_seq_open, | |
2085 | .read = seq_read, | |
2086 | .llseek = seq_lseek, | |
2087 | .release = seq_release_private, | |
2088 | }; | |
2089 | ||
2090 | #endif | |
2091 | ||
2092 | static struct net_proto_family unix_family_ops = { | |
2093 | .family = PF_UNIX, | |
2094 | .create = unix_create, | |
2095 | .owner = THIS_MODULE, | |
2096 | }; | |
2097 | ||
1da177e4 LT |
2098 | static int __init af_unix_init(void) |
2099 | { | |
2100 | int rc = -1; | |
2101 | struct sk_buff *dummy_skb; | |
2102 | ||
ef047f5e | 2103 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 LT |
2104 | |
2105 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 YH |
2106 | if (rc != 0) { |
2107 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
1da177e4 LT |
2108 | __FUNCTION__); |
2109 | goto out; | |
2110 | } | |
2111 | ||
2112 | sock_register(&unix_family_ops); | |
2113 | #ifdef CONFIG_PROC_FS | |
2114 | proc_net_fops_create("unix", 0, &unix_seq_fops); | |
2115 | #endif | |
2116 | unix_sysctl_register(); | |
2117 | out: | |
2118 | return rc; | |
2119 | } | |
2120 | ||
2121 | static void __exit af_unix_exit(void) | |
2122 | { | |
2123 | sock_unregister(PF_UNIX); | |
2124 | unix_sysctl_unregister(); | |
2125 | proc_net_remove("unix"); | |
2126 | proto_unregister(&unix_proto); | |
2127 | } | |
2128 | ||
2129 | module_init(af_unix_init); | |
2130 | module_exit(af_unix_exit); | |
2131 | ||
2132 | MODULE_LICENSE("GPL"); | |
2133 | MODULE_ALIAS_NETPROTO(PF_UNIX); |