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> | |
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); |
1fd05ba5 MS |
595 | atomic_set(&u->inflight, 0); |
596 | INIT_LIST_HEAD(&u->link); | |
57b47a53 | 597 | mutex_init(&u->readlock); /* single task reading lock */ |
1da177e4 LT |
598 | init_waitqueue_head(&u->peer_wait); |
599 | unix_insert_socket(unix_sockets_unbound, sk); | |
600 | out: | |
601 | return sk; | |
602 | } | |
603 | ||
604 | static int unix_create(struct socket *sock, int protocol) | |
605 | { | |
606 | if (protocol && protocol != PF_UNIX) | |
607 | return -EPROTONOSUPPORT; | |
608 | ||
609 | sock->state = SS_UNCONNECTED; | |
610 | ||
611 | switch (sock->type) { | |
612 | case SOCK_STREAM: | |
613 | sock->ops = &unix_stream_ops; | |
614 | break; | |
615 | /* | |
616 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
617 | * nothing uses it. | |
618 | */ | |
619 | case SOCK_RAW: | |
620 | sock->type=SOCK_DGRAM; | |
621 | case SOCK_DGRAM: | |
622 | sock->ops = &unix_dgram_ops; | |
623 | break; | |
624 | case SOCK_SEQPACKET: | |
625 | sock->ops = &unix_seqpacket_ops; | |
626 | break; | |
627 | default: | |
628 | return -ESOCKTNOSUPPORT; | |
629 | } | |
630 | ||
631 | return unix_create1(sock) ? 0 : -ENOMEM; | |
632 | } | |
633 | ||
634 | static int unix_release(struct socket *sock) | |
635 | { | |
636 | struct sock *sk = sock->sk; | |
637 | ||
638 | if (!sk) | |
639 | return 0; | |
640 | ||
641 | sock->sk = NULL; | |
642 | ||
643 | return unix_release_sock (sk, 0); | |
644 | } | |
645 | ||
646 | static int unix_autobind(struct socket *sock) | |
647 | { | |
648 | struct sock *sk = sock->sk; | |
649 | struct unix_sock *u = unix_sk(sk); | |
650 | static u32 ordernum = 1; | |
651 | struct unix_address * addr; | |
652 | int err; | |
653 | ||
57b47a53 | 654 | mutex_lock(&u->readlock); |
1da177e4 LT |
655 | |
656 | err = 0; | |
657 | if (u->addr) | |
658 | goto out; | |
659 | ||
660 | err = -ENOMEM; | |
0da974f4 | 661 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
1da177e4 LT |
662 | if (!addr) |
663 | goto out; | |
664 | ||
1da177e4 LT |
665 | addr->name->sun_family = AF_UNIX; |
666 | atomic_set(&addr->refcnt, 1); | |
667 | ||
668 | retry: | |
669 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); | |
670 | addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0)); | |
671 | ||
fbe9cc4a | 672 | spin_lock(&unix_table_lock); |
1da177e4 LT |
673 | ordernum = (ordernum+1)&0xFFFFF; |
674 | ||
675 | if (__unix_find_socket_byname(addr->name, addr->len, sock->type, | |
676 | addr->hash)) { | |
fbe9cc4a | 677 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
678 | /* Sanity yield. It is unusual case, but yet... */ |
679 | if (!(ordernum&0xFF)) | |
680 | yield(); | |
681 | goto retry; | |
682 | } | |
683 | addr->hash ^= sk->sk_type; | |
684 | ||
685 | __unix_remove_socket(sk); | |
686 | u->addr = addr; | |
687 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); | |
fbe9cc4a | 688 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
689 | err = 0; |
690 | ||
57b47a53 | 691 | out: mutex_unlock(&u->readlock); |
1da177e4 LT |
692 | return err; |
693 | } | |
694 | ||
695 | static struct sock *unix_find_other(struct sockaddr_un *sunname, int len, | |
696 | int type, unsigned hash, int *error) | |
697 | { | |
698 | struct sock *u; | |
699 | struct nameidata nd; | |
700 | int err = 0; | |
ac7bfa62 | 701 | |
1da177e4 LT |
702 | if (sunname->sun_path[0]) { |
703 | err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd); | |
704 | if (err) | |
705 | goto fail; | |
e4543edd | 706 | err = vfs_permission(&nd, MAY_WRITE); |
1da177e4 LT |
707 | if (err) |
708 | goto put_fail; | |
709 | ||
710 | err = -ECONNREFUSED; | |
711 | if (!S_ISSOCK(nd.dentry->d_inode->i_mode)) | |
712 | goto put_fail; | |
713 | u=unix_find_socket_byinode(nd.dentry->d_inode); | |
714 | if (!u) | |
715 | goto put_fail; | |
716 | ||
717 | if (u->sk_type == type) | |
718 | touch_atime(nd.mnt, nd.dentry); | |
719 | ||
720 | path_release(&nd); | |
721 | ||
722 | err=-EPROTOTYPE; | |
723 | if (u->sk_type != type) { | |
724 | sock_put(u); | |
725 | goto fail; | |
726 | } | |
727 | } else { | |
728 | err = -ECONNREFUSED; | |
729 | u=unix_find_socket_byname(sunname, len, type, hash); | |
730 | if (u) { | |
731 | struct dentry *dentry; | |
732 | dentry = unix_sk(u)->dentry; | |
733 | if (dentry) | |
734 | touch_atime(unix_sk(u)->mnt, dentry); | |
735 | } else | |
736 | goto fail; | |
737 | } | |
738 | return u; | |
739 | ||
740 | put_fail: | |
741 | path_release(&nd); | |
742 | fail: | |
743 | *error=err; | |
744 | return NULL; | |
745 | } | |
746 | ||
747 | ||
748 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) | |
749 | { | |
750 | struct sock *sk = sock->sk; | |
751 | struct unix_sock *u = unix_sk(sk); | |
752 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
753 | struct dentry * dentry = NULL; | |
754 | struct nameidata nd; | |
755 | int err; | |
756 | unsigned hash; | |
757 | struct unix_address *addr; | |
758 | struct hlist_head *list; | |
759 | ||
760 | err = -EINVAL; | |
761 | if (sunaddr->sun_family != AF_UNIX) | |
762 | goto out; | |
763 | ||
764 | if (addr_len==sizeof(short)) { | |
765 | err = unix_autobind(sock); | |
766 | goto out; | |
767 | } | |
768 | ||
769 | err = unix_mkname(sunaddr, addr_len, &hash); | |
770 | if (err < 0) | |
771 | goto out; | |
772 | addr_len = err; | |
773 | ||
57b47a53 | 774 | mutex_lock(&u->readlock); |
1da177e4 LT |
775 | |
776 | err = -EINVAL; | |
777 | if (u->addr) | |
778 | goto out_up; | |
779 | ||
780 | err = -ENOMEM; | |
781 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); | |
782 | if (!addr) | |
783 | goto out_up; | |
784 | ||
785 | memcpy(addr->name, sunaddr, addr_len); | |
786 | addr->len = addr_len; | |
787 | addr->hash = hash ^ sk->sk_type; | |
788 | atomic_set(&addr->refcnt, 1); | |
789 | ||
790 | if (sunaddr->sun_path[0]) { | |
791 | unsigned int mode; | |
792 | err = 0; | |
793 | /* | |
794 | * Get the parent directory, calculate the hash for last | |
795 | * component. | |
796 | */ | |
797 | err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); | |
798 | if (err) | |
799 | goto out_mknod_parent; | |
f81a0bff CH |
800 | |
801 | dentry = lookup_create(&nd, 0); | |
1da177e4 LT |
802 | err = PTR_ERR(dentry); |
803 | if (IS_ERR(dentry)) | |
804 | goto out_mknod_unlock; | |
f81a0bff | 805 | |
1da177e4 LT |
806 | /* |
807 | * All right, let's create it. | |
808 | */ | |
809 | mode = S_IFSOCK | | |
810 | (SOCK_INODE(sock)->i_mode & ~current->fs->umask); | |
811 | err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0); | |
812 | if (err) | |
813 | goto out_mknod_dput; | |
1b1dcc1b | 814 | mutex_unlock(&nd.dentry->d_inode->i_mutex); |
1da177e4 LT |
815 | dput(nd.dentry); |
816 | nd.dentry = dentry; | |
817 | ||
818 | addr->hash = UNIX_HASH_SIZE; | |
819 | } | |
820 | ||
fbe9cc4a | 821 | spin_lock(&unix_table_lock); |
1da177e4 LT |
822 | |
823 | if (!sunaddr->sun_path[0]) { | |
824 | err = -EADDRINUSE; | |
825 | if (__unix_find_socket_byname(sunaddr, addr_len, | |
826 | sk->sk_type, hash)) { | |
827 | unix_release_addr(addr); | |
828 | goto out_unlock; | |
829 | } | |
830 | ||
831 | list = &unix_socket_table[addr->hash]; | |
832 | } else { | |
833 | list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; | |
834 | u->dentry = nd.dentry; | |
835 | u->mnt = nd.mnt; | |
836 | } | |
837 | ||
838 | err = 0; | |
839 | __unix_remove_socket(sk); | |
840 | u->addr = addr; | |
841 | __unix_insert_socket(list, sk); | |
842 | ||
843 | out_unlock: | |
fbe9cc4a | 844 | spin_unlock(&unix_table_lock); |
1da177e4 | 845 | out_up: |
57b47a53 | 846 | mutex_unlock(&u->readlock); |
1da177e4 LT |
847 | out: |
848 | return err; | |
849 | ||
850 | out_mknod_dput: | |
851 | dput(dentry); | |
852 | out_mknod_unlock: | |
1b1dcc1b | 853 | mutex_unlock(&nd.dentry->d_inode->i_mutex); |
1da177e4 LT |
854 | path_release(&nd); |
855 | out_mknod_parent: | |
856 | if (err==-EEXIST) | |
857 | err=-EADDRINUSE; | |
858 | unix_release_addr(addr); | |
859 | goto out_up; | |
860 | } | |
861 | ||
278a3de5 DM |
862 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
863 | { | |
864 | if (unlikely(sk1 == sk2) || !sk2) { | |
865 | unix_state_lock(sk1); | |
866 | return; | |
867 | } | |
868 | if (sk1 < sk2) { | |
869 | unix_state_lock(sk1); | |
870 | unix_state_lock_nested(sk2); | |
871 | } else { | |
872 | unix_state_lock(sk2); | |
873 | unix_state_lock_nested(sk1); | |
874 | } | |
875 | } | |
876 | ||
877 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
878 | { | |
879 | if (unlikely(sk1 == sk2) || !sk2) { | |
880 | unix_state_unlock(sk1); | |
881 | return; | |
882 | } | |
883 | unix_state_unlock(sk1); | |
884 | unix_state_unlock(sk2); | |
885 | } | |
886 | ||
1da177e4 LT |
887 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
888 | int alen, int flags) | |
889 | { | |
890 | struct sock *sk = sock->sk; | |
891 | struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr; | |
892 | struct sock *other; | |
893 | unsigned hash; | |
894 | int err; | |
895 | ||
896 | if (addr->sa_family != AF_UNSPEC) { | |
897 | err = unix_mkname(sunaddr, alen, &hash); | |
898 | if (err < 0) | |
899 | goto out; | |
900 | alen = err; | |
901 | ||
902 | if (test_bit(SOCK_PASSCRED, &sock->flags) && | |
903 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) | |
904 | goto out; | |
905 | ||
278a3de5 | 906 | restart: |
1da177e4 LT |
907 | other=unix_find_other(sunaddr, alen, sock->type, hash, &err); |
908 | if (!other) | |
909 | goto out; | |
910 | ||
278a3de5 DM |
911 | unix_state_double_lock(sk, other); |
912 | ||
913 | /* Apparently VFS overslept socket death. Retry. */ | |
914 | if (sock_flag(other, SOCK_DEAD)) { | |
915 | unix_state_double_unlock(sk, other); | |
916 | sock_put(other); | |
917 | goto restart; | |
918 | } | |
1da177e4 LT |
919 | |
920 | err = -EPERM; | |
921 | if (!unix_may_send(sk, other)) | |
922 | goto out_unlock; | |
923 | ||
924 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
925 | if (err) | |
926 | goto out_unlock; | |
927 | ||
928 | } else { | |
929 | /* | |
930 | * 1003.1g breaking connected state with AF_UNSPEC | |
931 | */ | |
932 | other = NULL; | |
278a3de5 | 933 | unix_state_double_lock(sk, other); |
1da177e4 LT |
934 | } |
935 | ||
936 | /* | |
937 | * If it was connected, reconnect. | |
938 | */ | |
939 | if (unix_peer(sk)) { | |
940 | struct sock *old_peer = unix_peer(sk); | |
941 | unix_peer(sk)=other; | |
278a3de5 | 942 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
943 | |
944 | if (other != old_peer) | |
945 | unix_dgram_disconnected(sk, old_peer); | |
946 | sock_put(old_peer); | |
947 | } else { | |
948 | unix_peer(sk)=other; | |
278a3de5 | 949 | unix_state_double_unlock(sk, other); |
1da177e4 | 950 | } |
ac7bfa62 | 951 | return 0; |
1da177e4 LT |
952 | |
953 | out_unlock: | |
278a3de5 | 954 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
955 | sock_put(other); |
956 | out: | |
957 | return err; | |
958 | } | |
959 | ||
960 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
961 | { | |
962 | struct unix_sock *u = unix_sk(other); | |
963 | int sched; | |
964 | DEFINE_WAIT(wait); | |
965 | ||
966 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
967 | ||
968 | sched = !sock_flag(other, SOCK_DEAD) && | |
969 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
64a14651 | 970 | (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
971 | other->sk_max_ack_backlog); |
972 | ||
1c92b4e5 | 973 | unix_state_unlock(other); |
1da177e4 LT |
974 | |
975 | if (sched) | |
976 | timeo = schedule_timeout(timeo); | |
977 | ||
978 | finish_wait(&u->peer_wait, &wait); | |
979 | return timeo; | |
980 | } | |
981 | ||
982 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
983 | int addr_len, int flags) | |
984 | { | |
985 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
986 | struct sock *sk = sock->sk; | |
987 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; | |
988 | struct sock *newsk = NULL; | |
989 | struct sock *other = NULL; | |
990 | struct sk_buff *skb = NULL; | |
991 | unsigned hash; | |
992 | int st; | |
993 | int err; | |
994 | long timeo; | |
995 | ||
996 | err = unix_mkname(sunaddr, addr_len, &hash); | |
997 | if (err < 0) | |
998 | goto out; | |
999 | addr_len = err; | |
1000 | ||
1001 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
1002 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
1003 | goto out; | |
1004 | ||
1005 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1006 | ||
1007 | /* First of all allocate resources. | |
1008 | If we will make it after state is locked, | |
1009 | we will have to recheck all again in any case. | |
1010 | */ | |
1011 | ||
1012 | err = -ENOMEM; | |
1013 | ||
1014 | /* create new sock for complete connection */ | |
1015 | newsk = unix_create1(NULL); | |
1016 | if (newsk == NULL) | |
1017 | goto out; | |
1018 | ||
1019 | /* Allocate skb for sending to listening sock */ | |
1020 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1021 | if (skb == NULL) | |
1022 | goto out; | |
1023 | ||
1024 | restart: | |
1025 | /* Find listening sock. */ | |
1026 | other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err); | |
1027 | if (!other) | |
1028 | goto out; | |
1029 | ||
1030 | /* Latch state of peer */ | |
1c92b4e5 | 1031 | unix_state_lock(other); |
1da177e4 LT |
1032 | |
1033 | /* Apparently VFS overslept socket death. Retry. */ | |
1034 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1035 | unix_state_unlock(other); |
1da177e4 LT |
1036 | sock_put(other); |
1037 | goto restart; | |
1038 | } | |
1039 | ||
1040 | err = -ECONNREFUSED; | |
1041 | if (other->sk_state != TCP_LISTEN) | |
1042 | goto out_unlock; | |
1043 | ||
64a14651 | 1044 | if (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
1045 | other->sk_max_ack_backlog) { |
1046 | err = -EAGAIN; | |
1047 | if (!timeo) | |
1048 | goto out_unlock; | |
1049 | ||
1050 | timeo = unix_wait_for_peer(other, timeo); | |
1051 | ||
1052 | err = sock_intr_errno(timeo); | |
1053 | if (signal_pending(current)) | |
1054 | goto out; | |
1055 | sock_put(other); | |
1056 | goto restart; | |
ac7bfa62 | 1057 | } |
1da177e4 LT |
1058 | |
1059 | /* Latch our state. | |
1060 | ||
1061 | It is tricky place. We need to grab write lock and cannot | |
1062 | drop lock on peer. It is dangerous because deadlock is | |
1063 | possible. Connect to self case and simultaneous | |
1064 | attempt to connect are eliminated by checking socket | |
1065 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1066 | check this before attempt to grab lock. | |
1067 | ||
1068 | Well, and we have to recheck the state after socket locked. | |
1069 | */ | |
1070 | st = sk->sk_state; | |
1071 | ||
1072 | switch (st) { | |
1073 | case TCP_CLOSE: | |
1074 | /* This is ok... continue with connect */ | |
1075 | break; | |
1076 | case TCP_ESTABLISHED: | |
1077 | /* Socket is already connected */ | |
1078 | err = -EISCONN; | |
1079 | goto out_unlock; | |
1080 | default: | |
1081 | err = -EINVAL; | |
1082 | goto out_unlock; | |
1083 | } | |
1084 | ||
1c92b4e5 | 1085 | unix_state_lock_nested(sk); |
1da177e4 LT |
1086 | |
1087 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1088 | unix_state_unlock(sk); |
1089 | unix_state_unlock(other); | |
1da177e4 LT |
1090 | sock_put(other); |
1091 | goto restart; | |
1092 | } | |
1093 | ||
1094 | err = security_unix_stream_connect(sock, other->sk_socket, newsk); | |
1095 | if (err) { | |
1c92b4e5 | 1096 | unix_state_unlock(sk); |
1da177e4 LT |
1097 | goto out_unlock; |
1098 | } | |
1099 | ||
1100 | /* The way is open! Fastly set all the necessary fields... */ | |
1101 | ||
1102 | sock_hold(sk); | |
1103 | unix_peer(newsk) = sk; | |
1104 | newsk->sk_state = TCP_ESTABLISHED; | |
1105 | newsk->sk_type = sk->sk_type; | |
1106 | newsk->sk_peercred.pid = current->tgid; | |
1107 | newsk->sk_peercred.uid = current->euid; | |
1108 | newsk->sk_peercred.gid = current->egid; | |
1109 | newu = unix_sk(newsk); | |
1110 | newsk->sk_sleep = &newu->peer_wait; | |
1111 | otheru = unix_sk(other); | |
1112 | ||
1113 | /* copy address information from listening to new sock*/ | |
1114 | if (otheru->addr) { | |
1115 | atomic_inc(&otheru->addr->refcnt); | |
1116 | newu->addr = otheru->addr; | |
1117 | } | |
1118 | if (otheru->dentry) { | |
1119 | newu->dentry = dget(otheru->dentry); | |
1120 | newu->mnt = mntget(otheru->mnt); | |
1121 | } | |
1122 | ||
1123 | /* Set credentials */ | |
1124 | sk->sk_peercred = other->sk_peercred; | |
1125 | ||
1da177e4 LT |
1126 | sock->state = SS_CONNECTED; |
1127 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1128 | sock_hold(newsk); |
1129 | ||
1130 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ | |
1131 | unix_peer(sk) = newsk; | |
1da177e4 | 1132 | |
1c92b4e5 | 1133 | unix_state_unlock(sk); |
1da177e4 LT |
1134 | |
1135 | /* take ten and and send info to listening sock */ | |
1136 | spin_lock(&other->sk_receive_queue.lock); | |
1137 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1138 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1139 | unix_state_unlock(other); |
1da177e4 LT |
1140 | other->sk_data_ready(other, 0); |
1141 | sock_put(other); | |
1142 | return 0; | |
1143 | ||
1144 | out_unlock: | |
1145 | if (other) | |
1c92b4e5 | 1146 | unix_state_unlock(other); |
1da177e4 LT |
1147 | |
1148 | out: | |
1149 | if (skb) | |
1150 | kfree_skb(skb); | |
1151 | if (newsk) | |
1152 | unix_release_sock(newsk, 0); | |
1153 | if (other) | |
1154 | sock_put(other); | |
1155 | return err; | |
1156 | } | |
1157 | ||
1158 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1159 | { | |
1160 | struct sock *ska=socka->sk, *skb = sockb->sk; | |
1161 | ||
1162 | /* Join our sockets back to back */ | |
1163 | sock_hold(ska); | |
1164 | sock_hold(skb); | |
1165 | unix_peer(ska)=skb; | |
1166 | unix_peer(skb)=ska; | |
1167 | ska->sk_peercred.pid = skb->sk_peercred.pid = current->tgid; | |
1168 | ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid; | |
1169 | ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid; | |
1170 | ||
1171 | if (ska->sk_type != SOCK_DGRAM) { | |
1172 | ska->sk_state = TCP_ESTABLISHED; | |
1173 | skb->sk_state = TCP_ESTABLISHED; | |
1174 | socka->state = SS_CONNECTED; | |
1175 | sockb->state = SS_CONNECTED; | |
1176 | } | |
1177 | return 0; | |
1178 | } | |
1179 | ||
1180 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) | |
1181 | { | |
1182 | struct sock *sk = sock->sk; | |
1183 | struct sock *tsk; | |
1184 | struct sk_buff *skb; | |
1185 | int err; | |
1186 | ||
1187 | err = -EOPNOTSUPP; | |
1188 | if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) | |
1189 | goto out; | |
1190 | ||
1191 | err = -EINVAL; | |
1192 | if (sk->sk_state != TCP_LISTEN) | |
1193 | goto out; | |
1194 | ||
1195 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1196 | * so that no locks are necessary. | |
1197 | */ | |
1198 | ||
1199 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); | |
1200 | if (!skb) { | |
1201 | /* This means receive shutdown. */ | |
1202 | if (err == 0) | |
1203 | err = -EINVAL; | |
1204 | goto out; | |
1205 | } | |
1206 | ||
1207 | tsk = skb->sk; | |
1208 | skb_free_datagram(sk, skb); | |
1209 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1210 | ||
1211 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1212 | unix_state_lock(tsk); |
1da177e4 LT |
1213 | newsock->state = SS_CONNECTED; |
1214 | sock_graft(tsk, newsock); | |
1c92b4e5 | 1215 | unix_state_unlock(tsk); |
1da177e4 LT |
1216 | return 0; |
1217 | ||
1218 | out: | |
1219 | return err; | |
1220 | } | |
1221 | ||
1222 | ||
1223 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) | |
1224 | { | |
1225 | struct sock *sk = sock->sk; | |
1226 | struct unix_sock *u; | |
1227 | struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; | |
1228 | int err = 0; | |
1229 | ||
1230 | if (peer) { | |
1231 | sk = unix_peer_get(sk); | |
1232 | ||
1233 | err = -ENOTCONN; | |
1234 | if (!sk) | |
1235 | goto out; | |
1236 | err = 0; | |
1237 | } else { | |
1238 | sock_hold(sk); | |
1239 | } | |
1240 | ||
1241 | u = unix_sk(sk); | |
1c92b4e5 | 1242 | unix_state_lock(sk); |
1da177e4 LT |
1243 | if (!u->addr) { |
1244 | sunaddr->sun_family = AF_UNIX; | |
1245 | sunaddr->sun_path[0] = 0; | |
1246 | *uaddr_len = sizeof(short); | |
1247 | } else { | |
1248 | struct unix_address *addr = u->addr; | |
1249 | ||
1250 | *uaddr_len = addr->len; | |
1251 | memcpy(sunaddr, addr->name, *uaddr_len); | |
1252 | } | |
1c92b4e5 | 1253 | unix_state_unlock(sk); |
1da177e4 LT |
1254 | sock_put(sk); |
1255 | out: | |
1256 | return err; | |
1257 | } | |
1258 | ||
1259 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1260 | { | |
1261 | int i; | |
1262 | ||
1263 | scm->fp = UNIXCB(skb).fp; | |
1264 | skb->destructor = sock_wfree; | |
1265 | UNIXCB(skb).fp = NULL; | |
1266 | ||
1267 | for (i=scm->fp->count-1; i>=0; i--) | |
1268 | unix_notinflight(scm->fp->fp[i]); | |
1269 | } | |
1270 | ||
1271 | static void unix_destruct_fds(struct sk_buff *skb) | |
1272 | { | |
1273 | struct scm_cookie scm; | |
1274 | memset(&scm, 0, sizeof(scm)); | |
1275 | unix_detach_fds(&scm, skb); | |
1276 | ||
1277 | /* Alas, it calls VFS */ | |
1278 | /* So fscking what? fput() had been SMP-safe since the last Summer */ | |
1279 | scm_destroy(&scm); | |
1280 | sock_wfree(skb); | |
1281 | } | |
1282 | ||
1283 | static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) | |
1284 | { | |
1285 | int i; | |
1286 | for (i=scm->fp->count-1; i>=0; i--) | |
1287 | unix_inflight(scm->fp->fp[i]); | |
1288 | UNIXCB(skb).fp = scm->fp; | |
1289 | skb->destructor = unix_destruct_fds; | |
1290 | scm->fp = NULL; | |
1291 | } | |
1292 | ||
1293 | /* | |
1294 | * Send AF_UNIX data. | |
1295 | */ | |
1296 | ||
1297 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1298 | struct msghdr *msg, size_t len) | |
1299 | { | |
1300 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1301 | struct sock *sk = sock->sk; | |
1302 | struct unix_sock *u = unix_sk(sk); | |
1303 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1304 | struct sock *other = NULL; | |
1305 | int namelen = 0; /* fake GCC */ | |
1306 | int err; | |
1307 | unsigned hash; | |
1308 | struct sk_buff *skb; | |
1309 | long timeo; | |
1310 | struct scm_cookie tmp_scm; | |
1311 | ||
1312 | if (NULL == siocb->scm) | |
1313 | siocb->scm = &tmp_scm; | |
1314 | err = scm_send(sock, msg, siocb->scm); | |
1315 | if (err < 0) | |
1316 | return err; | |
1317 | ||
1318 | err = -EOPNOTSUPP; | |
1319 | if (msg->msg_flags&MSG_OOB) | |
1320 | goto out; | |
1321 | ||
1322 | if (msg->msg_namelen) { | |
1323 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); | |
1324 | if (err < 0) | |
1325 | goto out; | |
1326 | namelen = err; | |
1327 | } else { | |
1328 | sunaddr = NULL; | |
1329 | err = -ENOTCONN; | |
1330 | other = unix_peer_get(sk); | |
1331 | if (!other) | |
1332 | goto out; | |
1333 | } | |
1334 | ||
1335 | if (test_bit(SOCK_PASSCRED, &sock->flags) | |
1336 | && !u->addr && (err = unix_autobind(sock)) != 0) | |
1337 | goto out; | |
1338 | ||
1339 | err = -EMSGSIZE; | |
1340 | if (len > sk->sk_sndbuf - 32) | |
1341 | goto out; | |
1342 | ||
1343 | skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); | |
1344 | if (skb==NULL) | |
1345 | goto out; | |
1346 | ||
1347 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1348 | if (siocb->scm->fp) | |
1349 | unix_attach_fds(siocb->scm, skb); | |
dc49c1f9 | 1350 | unix_get_secdata(siocb->scm, skb); |
877ce7c1 | 1351 | |
badff6d0 | 1352 | skb_reset_transport_header(skb); |
1da177e4 LT |
1353 | err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); |
1354 | if (err) | |
1355 | goto out_free; | |
1356 | ||
1357 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1358 | ||
1359 | restart: | |
1360 | if (!other) { | |
1361 | err = -ECONNRESET; | |
1362 | if (sunaddr == NULL) | |
1363 | goto out_free; | |
1364 | ||
1365 | other = unix_find_other(sunaddr, namelen, sk->sk_type, | |
1366 | hash, &err); | |
1367 | if (other==NULL) | |
1368 | goto out_free; | |
1369 | } | |
1370 | ||
1c92b4e5 | 1371 | unix_state_lock(other); |
1da177e4 LT |
1372 | err = -EPERM; |
1373 | if (!unix_may_send(sk, other)) | |
1374 | goto out_unlock; | |
1375 | ||
1376 | if (sock_flag(other, SOCK_DEAD)) { | |
1377 | /* | |
1378 | * Check with 1003.1g - what should | |
1379 | * datagram error | |
1380 | */ | |
1c92b4e5 | 1381 | unix_state_unlock(other); |
1da177e4 LT |
1382 | sock_put(other); |
1383 | ||
1384 | err = 0; | |
1c92b4e5 | 1385 | unix_state_lock(sk); |
1da177e4 LT |
1386 | if (unix_peer(sk) == other) { |
1387 | unix_peer(sk)=NULL; | |
1c92b4e5 | 1388 | unix_state_unlock(sk); |
1da177e4 LT |
1389 | |
1390 | unix_dgram_disconnected(sk, other); | |
1391 | sock_put(other); | |
1392 | err = -ECONNREFUSED; | |
1393 | } else { | |
1c92b4e5 | 1394 | unix_state_unlock(sk); |
1da177e4 LT |
1395 | } |
1396 | ||
1397 | other = NULL; | |
1398 | if (err) | |
1399 | goto out_free; | |
1400 | goto restart; | |
1401 | } | |
1402 | ||
1403 | err = -EPIPE; | |
1404 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
1405 | goto out_unlock; | |
1406 | ||
1407 | if (sk->sk_type != SOCK_SEQPACKET) { | |
1408 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1409 | if (err) | |
1410 | goto out_unlock; | |
1411 | } | |
1412 | ||
1413 | if (unix_peer(other) != sk && | |
64a14651 | 1414 | (skb_queue_len(&other->sk_receive_queue) > |
1da177e4 LT |
1415 | other->sk_max_ack_backlog)) { |
1416 | if (!timeo) { | |
1417 | err = -EAGAIN; | |
1418 | goto out_unlock; | |
1419 | } | |
1420 | ||
1421 | timeo = unix_wait_for_peer(other, timeo); | |
1422 | ||
1423 | err = sock_intr_errno(timeo); | |
1424 | if (signal_pending(current)) | |
1425 | goto out_free; | |
1426 | ||
1427 | goto restart; | |
1428 | } | |
1429 | ||
1430 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1c92b4e5 | 1431 | unix_state_unlock(other); |
1da177e4 LT |
1432 | other->sk_data_ready(other, len); |
1433 | sock_put(other); | |
1434 | scm_destroy(siocb->scm); | |
1435 | return len; | |
1436 | ||
1437 | out_unlock: | |
1c92b4e5 | 1438 | unix_state_unlock(other); |
1da177e4 LT |
1439 | out_free: |
1440 | kfree_skb(skb); | |
1441 | out: | |
1442 | if (other) | |
1443 | sock_put(other); | |
1444 | scm_destroy(siocb->scm); | |
1445 | return err; | |
1446 | } | |
1447 | ||
ac7bfa62 | 1448 | |
1da177e4 LT |
1449 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1450 | struct msghdr *msg, size_t len) | |
1451 | { | |
1452 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1453 | struct sock *sk = sock->sk; | |
1454 | struct sock *other = NULL; | |
1455 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1456 | int err,size; | |
1457 | struct sk_buff *skb; | |
1458 | int sent=0; | |
1459 | struct scm_cookie tmp_scm; | |
1460 | ||
1461 | if (NULL == siocb->scm) | |
1462 | siocb->scm = &tmp_scm; | |
1463 | err = scm_send(sock, msg, siocb->scm); | |
1464 | if (err < 0) | |
1465 | return err; | |
1466 | ||
1467 | err = -EOPNOTSUPP; | |
1468 | if (msg->msg_flags&MSG_OOB) | |
1469 | goto out_err; | |
1470 | ||
1471 | if (msg->msg_namelen) { | |
1472 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
1473 | goto out_err; | |
1474 | } else { | |
1475 | sunaddr = NULL; | |
1476 | err = -ENOTCONN; | |
830a1e5c | 1477 | other = unix_peer(sk); |
1da177e4 LT |
1478 | if (!other) |
1479 | goto out_err; | |
1480 | } | |
1481 | ||
1482 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
1483 | goto pipe_err; | |
1484 | ||
1485 | while(sent < len) | |
1486 | { | |
1487 | /* | |
e9df7d7f BL |
1488 | * Optimisation for the fact that under 0.01% of X |
1489 | * messages typically need breaking up. | |
1da177e4 LT |
1490 | */ |
1491 | ||
e9df7d7f | 1492 | size = len-sent; |
1da177e4 LT |
1493 | |
1494 | /* Keep two messages in the pipe so it schedules better */ | |
e9df7d7f BL |
1495 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
1496 | size = (sk->sk_sndbuf >> 1) - 64; | |
1da177e4 LT |
1497 | |
1498 | if (size > SKB_MAX_ALLOC) | |
1499 | size = SKB_MAX_ALLOC; | |
ac7bfa62 | 1500 | |
1da177e4 LT |
1501 | /* |
1502 | * Grab a buffer | |
1503 | */ | |
ac7bfa62 | 1504 | |
1da177e4 LT |
1505 | skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); |
1506 | ||
1507 | if (skb==NULL) | |
1508 | goto out_err; | |
1509 | ||
1510 | /* | |
1511 | * If you pass two values to the sock_alloc_send_skb | |
1512 | * it tries to grab the large buffer with GFP_NOFS | |
1513 | * (which can fail easily), and if it fails grab the | |
1514 | * fallback size buffer which is under a page and will | |
1515 | * succeed. [Alan] | |
1516 | */ | |
1517 | size = min_t(int, size, skb_tailroom(skb)); | |
1518 | ||
1519 | memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
1520 | if (siocb->scm->fp) | |
1521 | unix_attach_fds(siocb->scm, skb); | |
1522 | ||
1523 | if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { | |
1524 | kfree_skb(skb); | |
1525 | goto out_err; | |
1526 | } | |
1527 | ||
1c92b4e5 | 1528 | unix_state_lock(other); |
1da177e4 LT |
1529 | |
1530 | if (sock_flag(other, SOCK_DEAD) || | |
1531 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
1532 | goto pipe_err_free; | |
1533 | ||
1534 | skb_queue_tail(&other->sk_receive_queue, skb); | |
1c92b4e5 | 1535 | unix_state_unlock(other); |
1da177e4 LT |
1536 | other->sk_data_ready(other, size); |
1537 | sent+=size; | |
1538 | } | |
1da177e4 LT |
1539 | |
1540 | scm_destroy(siocb->scm); | |
1541 | siocb->scm = NULL; | |
1542 | ||
1543 | return sent; | |
1544 | ||
1545 | pipe_err_free: | |
1c92b4e5 | 1546 | unix_state_unlock(other); |
1da177e4 LT |
1547 | kfree_skb(skb); |
1548 | pipe_err: | |
1549 | if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) | |
1550 | send_sig(SIGPIPE,current,0); | |
1551 | err = -EPIPE; | |
1552 | out_err: | |
1da177e4 LT |
1553 | scm_destroy(siocb->scm); |
1554 | siocb->scm = NULL; | |
1555 | return sent ? : err; | |
1556 | } | |
1557 | ||
1558 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1559 | struct msghdr *msg, size_t len) | |
1560 | { | |
1561 | int err; | |
1562 | struct sock *sk = sock->sk; | |
ac7bfa62 | 1563 | |
1da177e4 LT |
1564 | err = sock_error(sk); |
1565 | if (err) | |
1566 | return err; | |
1567 | ||
1568 | if (sk->sk_state != TCP_ESTABLISHED) | |
1569 | return -ENOTCONN; | |
1570 | ||
1571 | if (msg->msg_namelen) | |
1572 | msg->msg_namelen = 0; | |
1573 | ||
1574 | return unix_dgram_sendmsg(kiocb, sock, msg, len); | |
1575 | } | |
ac7bfa62 | 1576 | |
1da177e4 LT |
1577 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
1578 | { | |
1579 | struct unix_sock *u = unix_sk(sk); | |
1580 | ||
1581 | msg->msg_namelen = 0; | |
1582 | if (u->addr) { | |
1583 | msg->msg_namelen = u->addr->len; | |
1584 | memcpy(msg->msg_name, u->addr->name, u->addr->len); | |
1585 | } | |
1586 | } | |
1587 | ||
1588 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1589 | struct msghdr *msg, size_t size, | |
1590 | int flags) | |
1591 | { | |
1592 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1593 | struct scm_cookie tmp_scm; | |
1594 | struct sock *sk = sock->sk; | |
1595 | struct unix_sock *u = unix_sk(sk); | |
1596 | int noblock = flags & MSG_DONTWAIT; | |
1597 | struct sk_buff *skb; | |
1598 | int err; | |
1599 | ||
1600 | err = -EOPNOTSUPP; | |
1601 | if (flags&MSG_OOB) | |
1602 | goto out; | |
1603 | ||
1604 | msg->msg_namelen = 0; | |
1605 | ||
57b47a53 | 1606 | mutex_lock(&u->readlock); |
1da177e4 LT |
1607 | |
1608 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
1609 | if (!skb) | |
1610 | goto out_unlock; | |
1611 | ||
1612 | wake_up_interruptible(&u->peer_wait); | |
1613 | ||
1614 | if (msg->msg_name) | |
1615 | unix_copy_addr(msg, skb->sk); | |
1616 | ||
1617 | if (size > skb->len) | |
1618 | size = skb->len; | |
1619 | else if (size < skb->len) | |
1620 | msg->msg_flags |= MSG_TRUNC; | |
1621 | ||
1622 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); | |
1623 | if (err) | |
1624 | goto out_free; | |
1625 | ||
1626 | if (!siocb->scm) { | |
1627 | siocb->scm = &tmp_scm; | |
1628 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1629 | } | |
1630 | siocb->scm->creds = *UNIXCREDS(skb); | |
877ce7c1 | 1631 | unix_set_secdata(siocb->scm, skb); |
1da177e4 LT |
1632 | |
1633 | if (!(flags & MSG_PEEK)) | |
1634 | { | |
1635 | if (UNIXCB(skb).fp) | |
1636 | unix_detach_fds(siocb->scm, skb); | |
1637 | } | |
ac7bfa62 | 1638 | else |
1da177e4 LT |
1639 | { |
1640 | /* It is questionable: on PEEK we could: | |
1641 | - do not return fds - good, but too simple 8) | |
1642 | - return fds, and do not return them on read (old strategy, | |
1643 | apparently wrong) | |
1644 | - clone fds (I chose it for now, it is the most universal | |
1645 | solution) | |
ac7bfa62 YH |
1646 | |
1647 | POSIX 1003.1g does not actually define this clearly | |
1648 | at all. POSIX 1003.1g doesn't define a lot of things | |
1649 | clearly however! | |
1650 | ||
1da177e4 LT |
1651 | */ |
1652 | if (UNIXCB(skb).fp) | |
1653 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1654 | } | |
1655 | err = size; | |
1656 | ||
1657 | scm_recv(sock, msg, siocb->scm, flags); | |
1658 | ||
1659 | out_free: | |
1660 | skb_free_datagram(sk,skb); | |
1661 | out_unlock: | |
57b47a53 | 1662 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1663 | out: |
1664 | return err; | |
1665 | } | |
1666 | ||
1667 | /* | |
1668 | * Sleep until data has arrive. But check for races.. | |
1669 | */ | |
ac7bfa62 | 1670 | |
1da177e4 LT |
1671 | static long unix_stream_data_wait(struct sock * sk, long timeo) |
1672 | { | |
1673 | DEFINE_WAIT(wait); | |
1674 | ||
1c92b4e5 | 1675 | unix_state_lock(sk); |
1da177e4 LT |
1676 | |
1677 | for (;;) { | |
1678 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
1679 | ||
b03efcfb | 1680 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
1da177e4 LT |
1681 | sk->sk_err || |
1682 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1683 | signal_pending(current) || | |
1684 | !timeo) | |
1685 | break; | |
1686 | ||
1687 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); | |
1c92b4e5 | 1688 | unix_state_unlock(sk); |
1da177e4 | 1689 | timeo = schedule_timeout(timeo); |
1c92b4e5 | 1690 | unix_state_lock(sk); |
1da177e4 LT |
1691 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
1692 | } | |
1693 | ||
1694 | finish_wait(sk->sk_sleep, &wait); | |
1c92b4e5 | 1695 | unix_state_unlock(sk); |
1da177e4 LT |
1696 | return timeo; |
1697 | } | |
1698 | ||
1699 | ||
1700 | ||
1701 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, | |
1702 | struct msghdr *msg, size_t size, | |
1703 | int flags) | |
1704 | { | |
1705 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); | |
1706 | struct scm_cookie tmp_scm; | |
1707 | struct sock *sk = sock->sk; | |
1708 | struct unix_sock *u = unix_sk(sk); | |
1709 | struct sockaddr_un *sunaddr=msg->msg_name; | |
1710 | int copied = 0; | |
1711 | int check_creds = 0; | |
1712 | int target; | |
1713 | int err = 0; | |
1714 | long timeo; | |
1715 | ||
1716 | err = -EINVAL; | |
1717 | if (sk->sk_state != TCP_ESTABLISHED) | |
1718 | goto out; | |
1719 | ||
1720 | err = -EOPNOTSUPP; | |
1721 | if (flags&MSG_OOB) | |
1722 | goto out; | |
1723 | ||
1724 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); | |
1725 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); | |
1726 | ||
1727 | msg->msg_namelen = 0; | |
1728 | ||
1729 | /* Lock the socket to prevent queue disordering | |
1730 | * while sleeps in memcpy_tomsg | |
1731 | */ | |
1732 | ||
1733 | if (!siocb->scm) { | |
1734 | siocb->scm = &tmp_scm; | |
1735 | memset(&tmp_scm, 0, sizeof(tmp_scm)); | |
1736 | } | |
1737 | ||
57b47a53 | 1738 | mutex_lock(&u->readlock); |
1da177e4 LT |
1739 | |
1740 | do | |
1741 | { | |
1742 | int chunk; | |
1743 | struct sk_buff *skb; | |
1744 | ||
3c0d2f37 | 1745 | unix_state_lock(sk); |
1da177e4 LT |
1746 | skb = skb_dequeue(&sk->sk_receive_queue); |
1747 | if (skb==NULL) | |
1748 | { | |
1749 | if (copied >= target) | |
3c0d2f37 | 1750 | goto unlock; |
1da177e4 LT |
1751 | |
1752 | /* | |
1753 | * POSIX 1003.1g mandates this order. | |
1754 | */ | |
ac7bfa62 | 1755 | |
1da177e4 | 1756 | if ((err = sock_error(sk)) != 0) |
3c0d2f37 | 1757 | goto unlock; |
1da177e4 | 1758 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
1759 | goto unlock; |
1760 | ||
1761 | unix_state_unlock(sk); | |
1da177e4 LT |
1762 | err = -EAGAIN; |
1763 | if (!timeo) | |
1764 | break; | |
57b47a53 | 1765 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1766 | |
1767 | timeo = unix_stream_data_wait(sk, timeo); | |
1768 | ||
1769 | if (signal_pending(current)) { | |
1770 | err = sock_intr_errno(timeo); | |
1771 | goto out; | |
1772 | } | |
57b47a53 | 1773 | mutex_lock(&u->readlock); |
1da177e4 | 1774 | continue; |
3c0d2f37 MS |
1775 | unlock: |
1776 | unix_state_unlock(sk); | |
1777 | break; | |
1da177e4 | 1778 | } |
3c0d2f37 | 1779 | unix_state_unlock(sk); |
1da177e4 LT |
1780 | |
1781 | if (check_creds) { | |
1782 | /* Never glue messages from different writers */ | |
1783 | if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { | |
1784 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1785 | break; | |
1786 | } | |
1787 | } else { | |
1788 | /* Copy credentials */ | |
1789 | siocb->scm->creds = *UNIXCREDS(skb); | |
1790 | check_creds = 1; | |
1791 | } | |
1792 | ||
1793 | /* Copy address just once */ | |
1794 | if (sunaddr) | |
1795 | { | |
1796 | unix_copy_addr(msg, skb->sk); | |
1797 | sunaddr = NULL; | |
1798 | } | |
1799 | ||
1800 | chunk = min_t(unsigned int, skb->len, size); | |
1801 | if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { | |
1802 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1803 | if (copied == 0) | |
1804 | copied = -EFAULT; | |
1805 | break; | |
1806 | } | |
1807 | copied += chunk; | |
1808 | size -= chunk; | |
1809 | ||
1810 | /* Mark read part of skb as used */ | |
1811 | if (!(flags & MSG_PEEK)) | |
1812 | { | |
1813 | skb_pull(skb, chunk); | |
1814 | ||
1815 | if (UNIXCB(skb).fp) | |
1816 | unix_detach_fds(siocb->scm, skb); | |
1817 | ||
1818 | /* put the skb back if we didn't use it up.. */ | |
1819 | if (skb->len) | |
1820 | { | |
1821 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1822 | break; | |
1823 | } | |
1824 | ||
1825 | kfree_skb(skb); | |
1826 | ||
1827 | if (siocb->scm->fp) | |
1828 | break; | |
1829 | } | |
1830 | else | |
1831 | { | |
1832 | /* It is questionable, see note in unix_dgram_recvmsg. | |
1833 | */ | |
1834 | if (UNIXCB(skb).fp) | |
1835 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1836 | ||
1837 | /* put message back and return */ | |
1838 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1839 | break; | |
1840 | } | |
1841 | } while (size); | |
1842 | ||
57b47a53 | 1843 | mutex_unlock(&u->readlock); |
1da177e4 LT |
1844 | scm_recv(sock, msg, siocb->scm, flags); |
1845 | out: | |
1846 | return copied ? : err; | |
1847 | } | |
1848 | ||
1849 | static int unix_shutdown(struct socket *sock, int mode) | |
1850 | { | |
1851 | struct sock *sk = sock->sk; | |
1852 | struct sock *other; | |
1853 | ||
1854 | mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); | |
1855 | ||
1856 | if (mode) { | |
1c92b4e5 | 1857 | unix_state_lock(sk); |
1da177e4 LT |
1858 | sk->sk_shutdown |= mode; |
1859 | other=unix_peer(sk); | |
1860 | if (other) | |
1861 | sock_hold(other); | |
1c92b4e5 | 1862 | unix_state_unlock(sk); |
1da177e4 LT |
1863 | sk->sk_state_change(sk); |
1864 | ||
1865 | if (other && | |
1866 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
1867 | ||
1868 | int peer_mode = 0; | |
1869 | ||
1870 | if (mode&RCV_SHUTDOWN) | |
1871 | peer_mode |= SEND_SHUTDOWN; | |
1872 | if (mode&SEND_SHUTDOWN) | |
1873 | peer_mode |= RCV_SHUTDOWN; | |
1c92b4e5 | 1874 | unix_state_lock(other); |
1da177e4 | 1875 | other->sk_shutdown |= peer_mode; |
1c92b4e5 | 1876 | unix_state_unlock(other); |
1da177e4 LT |
1877 | other->sk_state_change(other); |
1878 | read_lock(&other->sk_callback_lock); | |
1879 | if (peer_mode == SHUTDOWN_MASK) | |
1880 | sk_wake_async(other,1,POLL_HUP); | |
1881 | else if (peer_mode & RCV_SHUTDOWN) | |
1882 | sk_wake_async(other,1,POLL_IN); | |
1883 | read_unlock(&other->sk_callback_lock); | |
1884 | } | |
1885 | if (other) | |
1886 | sock_put(other); | |
1887 | } | |
1888 | return 0; | |
1889 | } | |
1890 | ||
1891 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1892 | { | |
1893 | struct sock *sk = sock->sk; | |
1894 | long amount=0; | |
1895 | int err; | |
1896 | ||
1897 | switch(cmd) | |
1898 | { | |
1899 | case SIOCOUTQ: | |
1900 | amount = atomic_read(&sk->sk_wmem_alloc); | |
1901 | err = put_user(amount, (int __user *)arg); | |
1902 | break; | |
1903 | case SIOCINQ: | |
1904 | { | |
1905 | struct sk_buff *skb; | |
1906 | ||
1907 | if (sk->sk_state == TCP_LISTEN) { | |
1908 | err = -EINVAL; | |
1909 | break; | |
1910 | } | |
1911 | ||
1912 | spin_lock(&sk->sk_receive_queue.lock); | |
1913 | if (sk->sk_type == SOCK_STREAM || | |
1914 | sk->sk_type == SOCK_SEQPACKET) { | |
1915 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
1916 | amount += skb->len; | |
1917 | } else { | |
1918 | skb = skb_peek(&sk->sk_receive_queue); | |
1919 | if (skb) | |
1920 | amount=skb->len; | |
1921 | } | |
1922 | spin_unlock(&sk->sk_receive_queue.lock); | |
1923 | err = put_user(amount, (int __user *)arg); | |
1924 | break; | |
1925 | } | |
1926 | ||
1927 | default: | |
b5e5fa5e | 1928 | err = -ENOIOCTLCMD; |
1da177e4 LT |
1929 | break; |
1930 | } | |
1931 | return err; | |
1932 | } | |
1933 | ||
1934 | static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) | |
1935 | { | |
1936 | struct sock *sk = sock->sk; | |
1937 | unsigned int mask; | |
1938 | ||
1939 | poll_wait(file, sk->sk_sleep, wait); | |
1940 | mask = 0; | |
1941 | ||
1942 | /* exceptional events? */ | |
1943 | if (sk->sk_err) | |
1944 | mask |= POLLERR; | |
1945 | if (sk->sk_shutdown == SHUTDOWN_MASK) | |
1946 | mask |= POLLHUP; | |
f348d70a DL |
1947 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
1948 | mask |= POLLRDHUP; | |
1da177e4 LT |
1949 | |
1950 | /* readable? */ | |
1951 | if (!skb_queue_empty(&sk->sk_receive_queue) || | |
1952 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1953 | mask |= POLLIN | POLLRDNORM; | |
1954 | ||
1955 | /* Connection-based need to check for termination and startup */ | |
1956 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) | |
1957 | mask |= POLLHUP; | |
1958 | ||
1959 | /* | |
1960 | * we set writable also when the other side has shut down the | |
1961 | * connection. This prevents stuck sockets. | |
1962 | */ | |
1963 | if (unix_writable(sk)) | |
1964 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
1965 | ||
1966 | return mask; | |
1967 | } | |
1968 | ||
1969 | ||
1970 | #ifdef CONFIG_PROC_FS | |
1971 | static struct sock *unix_seq_idx(int *iter, loff_t pos) | |
1972 | { | |
1973 | loff_t off = 0; | |
1974 | struct sock *s; | |
1975 | ||
1976 | for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) { | |
ac7bfa62 | 1977 | if (off == pos) |
1da177e4 LT |
1978 | return s; |
1979 | ++off; | |
1980 | } | |
1981 | return NULL; | |
1982 | } | |
1983 | ||
1984 | ||
1985 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) | |
1986 | { | |
fbe9cc4a | 1987 | spin_lock(&unix_table_lock); |
1da177e4 LT |
1988 | return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1); |
1989 | } | |
1990 | ||
1991 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1992 | { | |
1993 | ++*pos; | |
1994 | ||
ac7bfa62 | 1995 | if (v == (void *)1) |
1da177e4 LT |
1996 | return first_unix_socket(seq->private); |
1997 | return next_unix_socket(seq->private, v); | |
1998 | } | |
1999 | ||
2000 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
2001 | { | |
fbe9cc4a | 2002 | spin_unlock(&unix_table_lock); |
1da177e4 LT |
2003 | } |
2004 | ||
2005 | static int unix_seq_show(struct seq_file *seq, void *v) | |
2006 | { | |
ac7bfa62 | 2007 | |
1da177e4 LT |
2008 | if (v == (void *)1) |
2009 | seq_puts(seq, "Num RefCount Protocol Flags Type St " | |
2010 | "Inode Path\n"); | |
2011 | else { | |
2012 | struct sock *s = v; | |
2013 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 2014 | unix_state_lock(s); |
1da177e4 LT |
2015 | |
2016 | seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", | |
2017 | s, | |
2018 | atomic_read(&s->sk_refcnt), | |
2019 | 0, | |
2020 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
2021 | s->sk_type, | |
2022 | s->sk_socket ? | |
2023 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
2024 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
2025 | sock_i_ino(s)); | |
2026 | ||
2027 | if (u->addr) { | |
2028 | int i, len; | |
2029 | seq_putc(seq, ' '); | |
2030 | ||
2031 | i = 0; | |
2032 | len = u->addr->len - sizeof(short); | |
2033 | if (!UNIX_ABSTRACT(s)) | |
2034 | len--; | |
2035 | else { | |
2036 | seq_putc(seq, '@'); | |
2037 | i++; | |
2038 | } | |
2039 | for ( ; i < len; i++) | |
2040 | seq_putc(seq, u->addr->name->sun_path[i]); | |
2041 | } | |
1c92b4e5 | 2042 | unix_state_unlock(s); |
1da177e4 LT |
2043 | seq_putc(seq, '\n'); |
2044 | } | |
2045 | ||
2046 | return 0; | |
2047 | } | |
2048 | ||
56b3d975 | 2049 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
2050 | .start = unix_seq_start, |
2051 | .next = unix_seq_next, | |
2052 | .stop = unix_seq_stop, | |
2053 | .show = unix_seq_show, | |
2054 | }; | |
2055 | ||
2056 | ||
2057 | static int unix_seq_open(struct inode *inode, struct file *file) | |
2058 | { | |
2059 | struct seq_file *seq; | |
2060 | int rc = -ENOMEM; | |
2061 | int *iter = kmalloc(sizeof(int), GFP_KERNEL); | |
2062 | ||
2063 | if (!iter) | |
2064 | goto out; | |
2065 | ||
2066 | rc = seq_open(file, &unix_seq_ops); | |
2067 | if (rc) | |
2068 | goto out_kfree; | |
2069 | ||
2070 | seq = file->private_data; | |
2071 | seq->private = iter; | |
2072 | *iter = 0; | |
2073 | out: | |
2074 | return rc; | |
2075 | out_kfree: | |
2076 | kfree(iter); | |
2077 | goto out; | |
2078 | } | |
2079 | ||
da7071d7 | 2080 | static const struct file_operations unix_seq_fops = { |
1da177e4 LT |
2081 | .owner = THIS_MODULE, |
2082 | .open = unix_seq_open, | |
2083 | .read = seq_read, | |
2084 | .llseek = seq_lseek, | |
2085 | .release = seq_release_private, | |
2086 | }; | |
2087 | ||
2088 | #endif | |
2089 | ||
2090 | static struct net_proto_family unix_family_ops = { | |
2091 | .family = PF_UNIX, | |
2092 | .create = unix_create, | |
2093 | .owner = THIS_MODULE, | |
2094 | }; | |
2095 | ||
1da177e4 LT |
2096 | static int __init af_unix_init(void) |
2097 | { | |
2098 | int rc = -1; | |
2099 | struct sk_buff *dummy_skb; | |
2100 | ||
ef047f5e | 2101 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 LT |
2102 | |
2103 | rc = proto_register(&unix_proto, 1); | |
ac7bfa62 YH |
2104 | if (rc != 0) { |
2105 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", | |
1da177e4 LT |
2106 | __FUNCTION__); |
2107 | goto out; | |
2108 | } | |
2109 | ||
2110 | sock_register(&unix_family_ops); | |
2111 | #ifdef CONFIG_PROC_FS | |
2112 | proc_net_fops_create("unix", 0, &unix_seq_fops); | |
2113 | #endif | |
2114 | unix_sysctl_register(); | |
2115 | out: | |
2116 | return rc; | |
2117 | } | |
2118 | ||
2119 | static void __exit af_unix_exit(void) | |
2120 | { | |
2121 | sock_unregister(PF_UNIX); | |
2122 | unix_sysctl_unregister(); | |
2123 | proc_net_remove("unix"); | |
2124 | proto_unregister(&unix_proto); | |
2125 | } | |
2126 | ||
2127 | module_init(af_unix_init); | |
2128 | module_exit(af_unix_exit); | |
2129 | ||
2130 | MODULE_LICENSE("GPL"); | |
2131 | MODULE_ALIAS_NETPROTO(PF_UNIX); |