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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * NET4: Implementation of BSD Unix domain sockets.
3 *
Alan Cox113aa832008-10-13 19:01:08 -07004 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * Fixes:
12 * Linus Torvalds : Assorted bug cures.
13 * Niibe Yutaka : async I/O support.
14 * Carsten Paeth : PF_UNIX check, address fixes.
15 * Alan Cox : Limit size of allocated blocks.
16 * Alan Cox : Fixed the stupid socketpair bug.
17 * Alan Cox : BSD compatibility fine tuning.
18 * Alan Cox : Fixed a bug in connect when interrupted.
19 * Alan Cox : Sorted out a proper draft version of
20 * file descriptor passing hacked up from
21 * Mike Shaver's work.
22 * Marty Leisner : Fixes to fd passing
23 * Nick Nevin : recvmsg bugfix.
24 * Alan Cox : Started proper garbage collector
25 * Heiko EiBfeldt : Missing verify_area check
26 * Alan Cox : Started POSIXisms
27 * Andreas Schwab : Replace inode by dentry for proper
28 * reference counting
29 * Kirk Petersen : Made this a module
30 * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
31 * Lots of bug fixes.
32 * Alexey Kuznetosv : Repaired (I hope) bugs introduces
33 * by above two patches.
34 * Andrea Arcangeli : If possible we block in connect(2)
35 * if the max backlog of the listen socket
36 * is been reached. This won't break
37 * old apps and it will avoid huge amount
38 * of socks hashed (this for unix_gc()
39 * performances reasons).
40 * Security fix that limits the max
41 * number of socks to 2*max_files and
42 * the number of skb queueable in the
43 * dgram receiver.
44 * Artur Skawina : Hash function optimizations
45 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
46 * Malcolm Beattie : Set peercred for socketpair
47 * Michal Ostrowski : Module initialization cleanup.
48 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
49 * the core infrastructure is doing that
50 * for all net proto families now (2.5.69+)
51 *
52 *
53 * Known differences from reference BSD that was tested:
54 *
55 * [TO FIX]
56 * ECONNREFUSED is not returned from one end of a connected() socket to the
57 * other the moment one end closes.
58 * fstat() doesn't return st_dev=0, and give the blksize as high water mark
59 * and a fake inode identifier (nor the BSD first socket fstat twice bug).
60 * [NOT TO FIX]
61 * accept() returns a path name even if the connecting socket has closed
62 * in the meantime (BSD loses the path and gives up).
63 * accept() returns 0 length path for an unbound connector. BSD returns 16
64 * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
65 * socketpair(...SOCK_RAW..) doesn't panic the kernel.
66 * BSD af_unix apparently has connect forgetting to block properly.
67 * (need to check this with the POSIX spec in detail)
68 *
69 * Differences from 2.0.0-11-... (ANK)
70 * Bug fixes and improvements.
71 * - client shutdown killed server socket.
72 * - removed all useless cli/sti pairs.
73 *
74 * Semantic changes/extensions.
75 * - generic control message passing.
76 * - SCM_CREDENTIALS control message.
77 * - "Abstract" (not FS based) socket bindings.
78 * Abstract names are sequences of bytes (not zero terminated)
79 * started by 0, so that this name space does not intersect
80 * with BSD names.
81 */
82
83#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#include <linux/signal.h>
86#include <linux/sched.h>
87#include <linux/errno.h>
88#include <linux/string.h>
89#include <linux/stat.h>
90#include <linux/dcache.h>
91#include <linux/namei.h>
92#include <linux/socket.h>
93#include <linux/un.h>
94#include <linux/fcntl.h>
95#include <linux/termios.h>
96#include <linux/sockios.h>
97#include <linux/net.h>
98#include <linux/in.h>
99#include <linux/fs.h>
100#include <linux/slab.h>
101#include <asm/uaccess.h>
102#include <linux/skbuff.h>
103#include <linux/netdevice.h>
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200104#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105#include <net/sock.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -0700106#include <net/tcp_states.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107#include <net/af_unix.h>
108#include <linux/proc_fs.h>
109#include <linux/seq_file.h>
110#include <net/scm.h>
111#include <linux/init.h>
112#include <linux/poll.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113#include <linux/rtnetlink.h>
114#include <linux/mount.h>
115#include <net/checksum.h>
116#include <linux/security.h>
117
Eric Dumazet7123aaa2012-06-08 05:03:21 +0000118struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
Pavel Emelyanovfa7ff562011-12-15 02:44:03 +0000119EXPORT_SYMBOL_GPL(unix_socket_table);
120DEFINE_SPINLOCK(unix_table_lock);
121EXPORT_SYMBOL_GPL(unix_table_lock);
Eric Dumazet518de9b2010-10-26 14:22:44 -0700122static atomic_long_t unix_nr_socks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Eric Dumazet7123aaa2012-06-08 05:03:21 +0000125static struct hlist_head *unix_sockets_unbound(void *addr)
126{
127 unsigned long hash = (unsigned long)addr;
128
129 hash ^= hash >> 16;
130 hash ^= hash >> 8;
131 hash %= UNIX_HASH_SIZE;
132 return &unix_socket_table[UNIX_HASH_SIZE + hash];
133}
134
135#define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700137#ifdef CONFIG_SECURITY_NETWORK
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700138static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700139{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700140 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700141}
142
143static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
144{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700145 scm->secid = *UNIXSID(skb);
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700146}
147#else
Catherine Zhangdc49c1f2006-08-02 14:12:06 -0700148static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700149{ }
150
151static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
152{ }
153#endif /* CONFIG_SECURITY_NETWORK */
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155/*
156 * SMP locking strategy:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800157 * hash table is protected with spinlock unix_table_lock
Stephen Hemminger663717f2010-02-18 14:12:06 -0800158 * each socket state is protected by separate spin lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 */
160
Eric Dumazet95c96172012-04-15 05:58:06 +0000161static inline unsigned int unix_hash_fold(__wsum n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
Eric Dumazet95c96172012-04-15 05:58:06 +0000163 unsigned int hash = (__force unsigned int)n;
164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 hash ^= hash>>16;
166 hash ^= hash>>8;
167 return hash&(UNIX_HASH_SIZE-1);
168}
169
170#define unix_peer(sk) (unix_sk(sk)->peer)
171
172static inline int unix_our_peer(struct sock *sk, struct sock *osk)
173{
174 return unix_peer(osk) == sk;
175}
176
177static inline int unix_may_send(struct sock *sk, struct sock *osk)
178{
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800179 return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180}
181
Rainer Weikusat3c734192008-06-17 22:28:05 -0700182static inline int unix_recvq_full(struct sock const *sk)
183{
184 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
185}
186
Pavel Emelyanovfa7ff562011-12-15 02:44:03 +0000187struct sock *unix_peer_get(struct sock *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188{
189 struct sock *peer;
190
David S. Miller1c92b4e2007-05-31 13:24:26 -0700191 unix_state_lock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 peer = unix_peer(s);
193 if (peer)
194 sock_hold(peer);
David S. Miller1c92b4e2007-05-31 13:24:26 -0700195 unix_state_unlock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 return peer;
197}
Pavel Emelyanovfa7ff562011-12-15 02:44:03 +0000198EXPORT_SYMBOL_GPL(unix_peer_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200static inline void unix_release_addr(struct unix_address *addr)
201{
202 if (atomic_dec_and_test(&addr->refcnt))
203 kfree(addr);
204}
205
206/*
207 * Check unix socket name:
208 * - should be not zero length.
209 * - if started by not zero, should be NULL terminated (FS object)
210 * - if started by zero, it is abstract name.
211 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900212
Eric Dumazet95c96172012-04-15 05:58:06 +0000213static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
215 if (len <= sizeof(short) || len > sizeof(*sunaddr))
216 return -EINVAL;
217 if (!sunaddr || sunaddr->sun_family != AF_UNIX)
218 return -EINVAL;
219 if (sunaddr->sun_path[0]) {
220 /*
221 * This may look like an off by one error but it is a bit more
222 * subtle. 108 is the longest valid AF_UNIX path for a binding.
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300223 * sun_path[108] doesn't as such exist. However in kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 * we are guaranteed that it is a valid memory location in our
225 * kernel address buffer.
226 */
Jianjun Konge27dfce2008-11-01 21:38:31 -0700227 ((char *)sunaddr)[len] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 len = strlen(sunaddr->sun_path)+1+sizeof(short);
229 return len;
230 }
231
Joe Perches07f07572008-11-19 15:44:53 -0800232 *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 return len;
234}
235
236static void __unix_remove_socket(struct sock *sk)
237{
238 sk_del_node_init(sk);
239}
240
241static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
242{
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700243 WARN_ON(!sk_unhashed(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 sk_add_node(sk, list);
245}
246
247static inline void unix_remove_socket(struct sock *sk)
248{
David S. Millerfbe9cc42005-12-13 23:26:29 -0800249 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 __unix_remove_socket(sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800251 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
253
254static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
255{
David S. Millerfbe9cc42005-12-13 23:26:29 -0800256 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 __unix_insert_socket(list, sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800258 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800261static struct sock *__unix_find_socket_byname(struct net *net,
262 struct sockaddr_un *sunname,
Eric Dumazet95c96172012-04-15 05:58:06 +0000263 int len, int type, unsigned int hash)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
265 struct sock *s;
266 struct hlist_node *node;
267
268 sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
269 struct unix_sock *u = unix_sk(s);
270
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900271 if (!net_eq(sock_net(s), net))
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800272 continue;
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 if (u->addr->len == len &&
275 !memcmp(u->addr->name, sunname, len))
276 goto found;
277 }
278 s = NULL;
279found:
280 return s;
281}
282
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800283static inline struct sock *unix_find_socket_byname(struct net *net,
284 struct sockaddr_un *sunname,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 int len, int type,
Eric Dumazet95c96172012-04-15 05:58:06 +0000286 unsigned int hash)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
288 struct sock *s;
289
David S. Millerfbe9cc42005-12-13 23:26:29 -0800290 spin_lock(&unix_table_lock);
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800291 s = __unix_find_socket_byname(net, sunname, len, type, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 if (s)
293 sock_hold(s);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800294 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 return s;
296}
297
Eric W. Biederman6616f782010-06-13 03:35:48 +0000298static struct sock *unix_find_socket_byinode(struct inode *i)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299{
300 struct sock *s;
301 struct hlist_node *node;
302
David S. Millerfbe9cc42005-12-13 23:26:29 -0800303 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 sk_for_each(s, node,
305 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
Al Viro40ffe672012-03-14 21:54:32 -0400306 struct dentry *dentry = unix_sk(s)->path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800308 if (dentry && dentry->d_inode == i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 sock_hold(s);
310 goto found;
311 }
312 }
313 s = NULL;
314found:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800315 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 return s;
317}
318
319static inline int unix_writable(struct sock *sk)
320{
321 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
322}
323
324static void unix_write_space(struct sock *sk)
325{
Eric Dumazet43815482010-04-29 11:01:49 +0000326 struct socket_wq *wq;
327
328 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 if (unix_writable(sk)) {
Eric Dumazet43815482010-04-29 11:01:49 +0000330 wq = rcu_dereference(sk->sk_wq);
331 if (wq_has_sleeper(wq))
Eric Dumazet67426b72010-10-29 20:44:44 +0000332 wake_up_interruptible_sync_poll(&wq->wait,
333 POLLOUT | POLLWRNORM | POLLWRBAND);
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +0800334 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 }
Eric Dumazet43815482010-04-29 11:01:49 +0000336 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337}
338
339/* When dgram socket disconnects (or changes its peer), we clear its receive
340 * queue of packets arrived from previous peer. First, it allows to do
341 * flow control based only on wmem_alloc; second, sk connected to peer
342 * may receive messages only from that peer. */
343static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
344{
David S. Millerb03efcf2005-07-08 14:57:23 -0700345 if (!skb_queue_empty(&sk->sk_receive_queue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 skb_queue_purge(&sk->sk_receive_queue);
347 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
348
349 /* If one link of bidirectional dgram pipe is disconnected,
350 * we signal error. Messages are lost. Do not make this,
351 * when peer was not connected to us.
352 */
353 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
354 other->sk_err = ECONNRESET;
355 other->sk_error_report(other);
356 }
357 }
358}
359
360static void unix_sock_destructor(struct sock *sk)
361{
362 struct unix_sock *u = unix_sk(sk);
363
364 skb_queue_purge(&sk->sk_receive_queue);
365
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700366 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
367 WARN_ON(!sk_unhashed(sk));
368 WARN_ON(sk->sk_socket);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 if (!sock_flag(sk, SOCK_DEAD)) {
Eric Dumazet6b41e7d2008-11-19 15:48:09 -0800370 printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 return;
372 }
373
374 if (u->addr)
375 unix_release_addr(u->addr);
376
Eric Dumazet518de9b2010-10-26 14:22:44 -0700377 atomic_long_dec(&unix_nr_socks);
David S. Miller6f756a82008-11-23 17:34:03 -0800378 local_bh_disable();
Eric Dumazeta8076d82008-11-17 02:38:49 -0800379 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
David S. Miller6f756a82008-11-23 17:34:03 -0800380 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381#ifdef UNIX_REFCNT_DEBUG
Eric Dumazet518de9b2010-10-26 14:22:44 -0700382 printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk,
383 atomic_long_read(&unix_nr_socks));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384#endif
385}
386
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800387static int unix_release_sock(struct sock *sk, int embrion)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388{
389 struct unix_sock *u = unix_sk(sk);
Al Viro40ffe672012-03-14 21:54:32 -0400390 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 struct sock *skpair;
392 struct sk_buff *skb;
393 int state;
394
395 unix_remove_socket(sk);
396
397 /* Clear state */
David S. Miller1c92b4e2007-05-31 13:24:26 -0700398 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 sock_orphan(sk);
400 sk->sk_shutdown = SHUTDOWN_MASK;
Al Viro40ffe672012-03-14 21:54:32 -0400401 path = u->path;
402 u->path.dentry = NULL;
403 u->path.mnt = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 state = sk->sk_state;
405 sk->sk_state = TCP_CLOSE;
David S. Miller1c92b4e2007-05-31 13:24:26 -0700406 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408 wake_up_interruptible_all(&u->peer_wait);
409
Jianjun Konge27dfce2008-11-01 21:38:31 -0700410 skpair = unix_peer(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
Jianjun Konge27dfce2008-11-01 21:38:31 -0700412 if (skpair != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
David S. Miller1c92b4e2007-05-31 13:24:26 -0700414 unix_state_lock(skpair);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 /* No more writes */
416 skpair->sk_shutdown = SHUTDOWN_MASK;
417 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
418 skpair->sk_err = ECONNRESET;
David S. Miller1c92b4e2007-05-31 13:24:26 -0700419 unix_state_unlock(skpair);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 skpair->sk_state_change(skpair);
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +0800421 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 }
423 sock_put(skpair); /* It may now die */
424 unix_peer(sk) = NULL;
425 }
426
427 /* Try to flush out this socket. Throw out buffers at least */
428
429 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
Jianjun Konge27dfce2008-11-01 21:38:31 -0700430 if (state == TCP_LISTEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 unix_release_sock(skb->sk, 1);
432 /* passed fds are erased in the kfree_skb hook */
433 kfree_skb(skb);
434 }
435
Al Viro40ffe672012-03-14 21:54:32 -0400436 if (path.dentry)
437 path_put(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 sock_put(sk);
440
441 /* ---- Socket is dead now and most probably destroyed ---- */
442
443 /*
Alan Coxe04dae82012-09-17 00:52:41 +0000444 * Fixme: BSD difference: In BSD all sockets connected to us get
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * ECONNRESET and we die on the spot. In Linux we behave
446 * like files and pipes do and wait for the last
447 * dereference.
448 *
449 * Can't we simply set sock->err?
450 *
451 * What the above comment does talk about? --ANK(980817)
452 */
453
Pavel Emelyanov9305cfa2007-11-10 22:06:01 -0800454 if (unix_tot_inflight)
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900455 unix_gc(); /* Garbage collect fds */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 return 0;
458}
459
Eric W. Biederman109f6e32010-06-13 03:30:14 +0000460static void init_peercred(struct sock *sk)
461{
462 put_pid(sk->sk_peer_pid);
463 if (sk->sk_peer_cred)
464 put_cred(sk->sk_peer_cred);
465 sk->sk_peer_pid = get_pid(task_tgid(current));
466 sk->sk_peer_cred = get_current_cred();
467}
468
469static void copy_peercred(struct sock *sk, struct sock *peersk)
470{
471 put_pid(sk->sk_peer_pid);
472 if (sk->sk_peer_cred)
473 put_cred(sk->sk_peer_cred);
474 sk->sk_peer_pid = get_pid(peersk->sk_peer_pid);
475 sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
476}
477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478static int unix_listen(struct socket *sock, int backlog)
479{
480 int err;
481 struct sock *sk = sock->sk;
482 struct unix_sock *u = unix_sk(sk);
Eric W. Biederman109f6e32010-06-13 03:30:14 +0000483 struct pid *old_pid = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485 err = -EOPNOTSUPP;
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800486 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
487 goto out; /* Only stream/seqpacket sockets accept */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 err = -EINVAL;
489 if (!u->addr)
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800490 goto out; /* No listens on an unbound socket */
David S. Miller1c92b4e2007-05-31 13:24:26 -0700491 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
493 goto out_unlock;
494 if (backlog > sk->sk_max_ack_backlog)
495 wake_up_interruptible_all(&u->peer_wait);
496 sk->sk_max_ack_backlog = backlog;
497 sk->sk_state = TCP_LISTEN;
498 /* set credentials so connect can copy them */
Eric W. Biederman109f6e32010-06-13 03:30:14 +0000499 init_peercred(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 err = 0;
501
502out_unlock:
David S. Miller1c92b4e2007-05-31 13:24:26 -0700503 unix_state_unlock(sk);
Eric W. Biederman109f6e32010-06-13 03:30:14 +0000504 put_pid(old_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505out:
506 return err;
507}
508
509static int unix_release(struct socket *);
510static int unix_bind(struct socket *, struct sockaddr *, int);
511static int unix_stream_connect(struct socket *, struct sockaddr *,
512 int addr_len, int flags);
513static int unix_socketpair(struct socket *, struct socket *);
514static int unix_accept(struct socket *, struct socket *, int);
515static int unix_getname(struct socket *, struct sockaddr *, int *, int);
516static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700517static unsigned int unix_dgram_poll(struct file *, struct socket *,
518 poll_table *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519static int unix_ioctl(struct socket *, unsigned int, unsigned long);
520static int unix_shutdown(struct socket *, int);
521static int unix_stream_sendmsg(struct kiocb *, struct socket *,
522 struct msghdr *, size_t);
523static int unix_stream_recvmsg(struct kiocb *, struct socket *,
524 struct msghdr *, size_t, int);
525static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
526 struct msghdr *, size_t);
527static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
528 struct msghdr *, size_t, int);
529static int unix_dgram_connect(struct socket *, struct sockaddr *,
530 int, int);
531static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
532 struct msghdr *, size_t);
Eric W. Biedermana05d2ad2011-04-24 01:54:57 +0000533static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *,
534 struct msghdr *, size_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +0000536static void unix_set_peek_off(struct sock *sk, int val)
537{
538 struct unix_sock *u = unix_sk(sk);
539
540 mutex_lock(&u->readlock);
541 sk->sk_peek_off = val;
542 mutex_unlock(&u->readlock);
543}
544
545
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800546static const struct proto_ops unix_stream_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 .family = PF_UNIX,
548 .owner = THIS_MODULE,
549 .release = unix_release,
550 .bind = unix_bind,
551 .connect = unix_stream_connect,
552 .socketpair = unix_socketpair,
553 .accept = unix_accept,
554 .getname = unix_getname,
555 .poll = unix_poll,
556 .ioctl = unix_ioctl,
557 .listen = unix_listen,
558 .shutdown = unix_shutdown,
559 .setsockopt = sock_no_setsockopt,
560 .getsockopt = sock_no_getsockopt,
561 .sendmsg = unix_stream_sendmsg,
562 .recvmsg = unix_stream_recvmsg,
563 .mmap = sock_no_mmap,
564 .sendpage = sock_no_sendpage,
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +0000565 .set_peek_off = unix_set_peek_off,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566};
567
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800568static const struct proto_ops unix_dgram_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 .family = PF_UNIX,
570 .owner = THIS_MODULE,
571 .release = unix_release,
572 .bind = unix_bind,
573 .connect = unix_dgram_connect,
574 .socketpair = unix_socketpair,
575 .accept = sock_no_accept,
576 .getname = unix_getname,
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700577 .poll = unix_dgram_poll,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 .ioctl = unix_ioctl,
579 .listen = sock_no_listen,
580 .shutdown = unix_shutdown,
581 .setsockopt = sock_no_setsockopt,
582 .getsockopt = sock_no_getsockopt,
583 .sendmsg = unix_dgram_sendmsg,
584 .recvmsg = unix_dgram_recvmsg,
585 .mmap = sock_no_mmap,
586 .sendpage = sock_no_sendpage,
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +0000587 .set_peek_off = unix_set_peek_off,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588};
589
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800590static const struct proto_ops unix_seqpacket_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 .family = PF_UNIX,
592 .owner = THIS_MODULE,
593 .release = unix_release,
594 .bind = unix_bind,
595 .connect = unix_stream_connect,
596 .socketpair = unix_socketpair,
597 .accept = unix_accept,
598 .getname = unix_getname,
Rainer Weikusatec0d2152008-06-27 19:34:18 -0700599 .poll = unix_dgram_poll,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 .ioctl = unix_ioctl,
601 .listen = unix_listen,
602 .shutdown = unix_shutdown,
603 .setsockopt = sock_no_setsockopt,
604 .getsockopt = sock_no_getsockopt,
605 .sendmsg = unix_seqpacket_sendmsg,
Eric W. Biedermana05d2ad2011-04-24 01:54:57 +0000606 .recvmsg = unix_seqpacket_recvmsg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 .mmap = sock_no_mmap,
608 .sendpage = sock_no_sendpage,
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +0000609 .set_peek_off = unix_set_peek_off,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610};
611
612static struct proto unix_proto = {
Eric Dumazet248969a2008-11-17 00:00:30 -0800613 .name = "UNIX",
614 .owner = THIS_MODULE,
Eric Dumazet248969a2008-11-17 00:00:30 -0800615 .obj_size = sizeof(struct unix_sock),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616};
617
Ingo Molnara09785a2006-07-03 00:25:12 -0700618/*
619 * AF_UNIX sockets do not interact with hardware, hence they
620 * dont trigger interrupts - so it's safe for them to have
621 * bh-unsafe locking for their sk_receive_queue.lock. Split off
622 * this special lock-class by reinitializing the spinlock key:
623 */
624static struct lock_class_key af_unix_sk_receive_queue_lock_key;
625
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800626static struct sock *unix_create1(struct net *net, struct socket *sock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627{
628 struct sock *sk = NULL;
629 struct unix_sock *u;
630
Eric Dumazet518de9b2010-10-26 14:22:44 -0700631 atomic_long_inc(&unix_nr_socks);
632 if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 goto out;
634
Pavel Emelyanov6257ff22007-11-01 00:39:31 -0700635 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if (!sk)
637 goto out;
638
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800639 sock_init_data(sock, sk);
Ingo Molnara09785a2006-07-03 00:25:12 -0700640 lockdep_set_class(&sk->sk_receive_queue.lock,
641 &af_unix_sk_receive_queue_lock_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 sk->sk_write_space = unix_write_space;
Denis V. Luneva0a53c82007-12-11 04:19:17 -0800644 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 sk->sk_destruct = unix_sock_destructor;
646 u = unix_sk(sk);
Al Viro40ffe672012-03-14 21:54:32 -0400647 u->path.dentry = NULL;
648 u->path.mnt = NULL;
Benjamin LaHaisefd19f322006-01-03 14:10:46 -0800649 spin_lock_init(&u->lock);
Al Viro516e0cc2008-07-26 00:39:17 -0400650 atomic_long_set(&u->inflight, 0);
Miklos Szeredi1fd05ba2007-07-11 14:22:39 -0700651 INIT_LIST_HEAD(&u->link);
Ingo Molnar57b47a52006-03-20 22:35:41 -0800652 mutex_init(&u->readlock); /* single task reading lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 init_waitqueue_head(&u->peer_wait);
Eric Dumazet7123aaa2012-06-08 05:03:21 +0000654 unix_insert_socket(unix_sockets_unbound(sk), sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655out:
Pavel Emelyanov284b3272007-11-10 22:08:30 -0800656 if (sk == NULL)
Eric Dumazet518de9b2010-10-26 14:22:44 -0700657 atomic_long_dec(&unix_nr_socks);
Eric Dumazet920de802008-11-24 00:09:29 -0800658 else {
659 local_bh_disable();
Eric Dumazeta8076d82008-11-17 02:38:49 -0800660 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
Eric Dumazet920de802008-11-24 00:09:29 -0800661 local_bh_enable();
662 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 return sk;
664}
665
Eric Paris3f378b62009-11-05 22:18:14 -0800666static int unix_create(struct net *net, struct socket *sock, int protocol,
667 int kern)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668{
669 if (protocol && protocol != PF_UNIX)
670 return -EPROTONOSUPPORT;
671
672 sock->state = SS_UNCONNECTED;
673
674 switch (sock->type) {
675 case SOCK_STREAM:
676 sock->ops = &unix_stream_ops;
677 break;
678 /*
679 * Believe it or not BSD has AF_UNIX, SOCK_RAW though
680 * nothing uses it.
681 */
682 case SOCK_RAW:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700683 sock->type = SOCK_DGRAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 case SOCK_DGRAM:
685 sock->ops = &unix_dgram_ops;
686 break;
687 case SOCK_SEQPACKET:
688 sock->ops = &unix_seqpacket_ops;
689 break;
690 default:
691 return -ESOCKTNOSUPPORT;
692 }
693
Eric W. Biederman1b8d7ae2007-10-08 23:24:22 -0700694 return unix_create1(net, sock) ? 0 : -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695}
696
697static int unix_release(struct socket *sock)
698{
699 struct sock *sk = sock->sk;
700
701 if (!sk)
702 return 0;
703
704 sock->sk = NULL;
705
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800706 return unix_release_sock(sk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707}
708
709static int unix_autobind(struct socket *sock)
710{
711 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900712 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 struct unix_sock *u = unix_sk(sk);
714 static u32 ordernum = 1;
Eric Dumazet6eba6a32008-11-16 22:58:44 -0800715 struct unix_address *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 int err;
Tetsuo Handa8df73ff2010-09-04 01:34:28 +0000717 unsigned int retries = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718
Ingo Molnar57b47a52006-03-20 22:35:41 -0800719 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
721 err = 0;
722 if (u->addr)
723 goto out;
724
725 err = -ENOMEM;
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700726 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 if (!addr)
728 goto out;
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 addr->name->sun_family = AF_UNIX;
731 atomic_set(&addr->refcnt, 1);
732
733retry:
734 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
Joe Perches07f07572008-11-19 15:44:53 -0800735 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
David S. Millerfbe9cc42005-12-13 23:26:29 -0800737 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 ordernum = (ordernum+1)&0xFFFFF;
739
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800740 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 addr->hash)) {
David S. Millerfbe9cc42005-12-13 23:26:29 -0800742 spin_unlock(&unix_table_lock);
Tetsuo Handa8df73ff2010-09-04 01:34:28 +0000743 /*
744 * __unix_find_socket_byname() may take long time if many names
745 * are already in use.
746 */
747 cond_resched();
748 /* Give up if all names seems to be in use. */
749 if (retries++ == 0xFFFFF) {
750 err = -ENOSPC;
751 kfree(addr);
752 goto out;
753 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 goto retry;
755 }
756 addr->hash ^= sk->sk_type;
757
758 __unix_remove_socket(sk);
759 u->addr = addr;
760 __unix_insert_socket(&unix_socket_table[addr->hash], sk);
David S. Millerfbe9cc42005-12-13 23:26:29 -0800761 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 err = 0;
763
Ingo Molnar57b47a52006-03-20 22:35:41 -0800764out: mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 return err;
766}
767
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800768static struct sock *unix_find_other(struct net *net,
769 struct sockaddr_un *sunname, int len,
Eric Dumazet95c96172012-04-15 05:58:06 +0000770 int type, unsigned int hash, int *error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771{
772 struct sock *u;
Al Viro421748e2008-08-02 01:04:36 -0400773 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 int err = 0;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +0900775
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 if (sunname->sun_path[0]) {
Al Viro421748e2008-08-02 01:04:36 -0400777 struct inode *inode;
778 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 if (err)
780 goto fail;
Al Viro421748e2008-08-02 01:04:36 -0400781 inode = path.dentry->d_inode;
782 err = inode_permission(inode, MAY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 if (err)
784 goto put_fail;
785
786 err = -ECONNREFUSED;
Al Viro421748e2008-08-02 01:04:36 -0400787 if (!S_ISSOCK(inode->i_mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 goto put_fail;
Eric W. Biederman6616f782010-06-13 03:35:48 +0000789 u = unix_find_socket_byinode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 if (!u)
791 goto put_fail;
792
793 if (u->sk_type == type)
Al Viro68ac1232012-03-15 08:21:57 -0400794 touch_atime(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795
Al Viro421748e2008-08-02 01:04:36 -0400796 path_put(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
Jianjun Konge27dfce2008-11-01 21:38:31 -0700798 err = -EPROTOTYPE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 if (u->sk_type != type) {
800 sock_put(u);
801 goto fail;
802 }
803 } else {
804 err = -ECONNREFUSED;
Jianjun Konge27dfce2008-11-01 21:38:31 -0700805 u = unix_find_socket_byname(net, sunname, len, type, hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 if (u) {
807 struct dentry *dentry;
Al Viro40ffe672012-03-14 21:54:32 -0400808 dentry = unix_sk(u)->path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 if (dentry)
Al Viro68ac1232012-03-15 08:21:57 -0400810 touch_atime(&unix_sk(u)->path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 } else
812 goto fail;
813 }
814 return u;
815
816put_fail:
Al Viro421748e2008-08-02 01:04:36 -0400817 path_put(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818fail:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700819 *error = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 return NULL;
821}
822
Al Virofaf02012012-07-20 02:37:29 +0400823static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
824{
825 struct dentry *dentry;
826 struct path path;
827 int err = 0;
828 /*
829 * Get the parent directory, calculate the hash for last
830 * component.
831 */
832 dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
833 err = PTR_ERR(dentry);
834 if (IS_ERR(dentry))
835 return err;
836
837 /*
838 * All right, let's create it.
839 */
840 err = security_path_mknod(&path, dentry, mode, 0);
841 if (!err) {
842 err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0);
843 if (!err) {
844 res->mnt = mntget(path.mnt);
845 res->dentry = dget(dentry);
846 }
847 }
848 done_path_create(&path, dentry);
849 return err;
850}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
852static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
853{
854 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900855 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -0700857 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
Al Virodae6ad82011-06-26 11:50:15 -0400858 char *sun_path = sunaddr->sun_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 int err;
Eric Dumazet95c96172012-04-15 05:58:06 +0000860 unsigned int hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 struct unix_address *addr;
862 struct hlist_head *list;
863
864 err = -EINVAL;
865 if (sunaddr->sun_family != AF_UNIX)
866 goto out;
867
Jianjun Konge27dfce2008-11-01 21:38:31 -0700868 if (addr_len == sizeof(short)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 err = unix_autobind(sock);
870 goto out;
871 }
872
873 err = unix_mkname(sunaddr, addr_len, &hash);
874 if (err < 0)
875 goto out;
876 addr_len = err;
877
Ingo Molnar57b47a52006-03-20 22:35:41 -0800878 mutex_lock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 err = -EINVAL;
881 if (u->addr)
882 goto out_up;
883
884 err = -ENOMEM;
885 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
886 if (!addr)
887 goto out_up;
888
889 memcpy(addr->name, sunaddr, addr_len);
890 addr->len = addr_len;
891 addr->hash = hash ^ sk->sk_type;
892 atomic_set(&addr->refcnt, 1);
893
Al Virodae6ad82011-06-26 11:50:15 -0400894 if (sun_path[0]) {
Al Virofaf02012012-07-20 02:37:29 +0400895 struct path path;
896 umode_t mode = S_IFSOCK |
Al Viroce3b0f82009-03-29 19:08:22 -0400897 (SOCK_INODE(sock)->i_mode & ~current_umask());
Al Virofaf02012012-07-20 02:37:29 +0400898 err = unix_mknod(sun_path, mode, &path);
899 if (err) {
900 if (err == -EEXIST)
901 err = -EADDRINUSE;
902 unix_release_addr(addr);
903 goto out_up;
904 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 addr->hash = UNIX_HASH_SIZE;
Al Virofaf02012012-07-20 02:37:29 +0400906 hash = path.dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1);
907 spin_lock(&unix_table_lock);
908 u->path = path;
909 list = &unix_socket_table[hash];
910 } else {
911 spin_lock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 err = -EADDRINUSE;
Denis V. Lunev097e66c2007-11-19 22:29:30 -0800913 if (__unix_find_socket_byname(net, sunaddr, addr_len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 sk->sk_type, hash)) {
915 unix_release_addr(addr);
916 goto out_unlock;
917 }
918
919 list = &unix_socket_table[addr->hash];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 }
921
922 err = 0;
923 __unix_remove_socket(sk);
924 u->addr = addr;
925 __unix_insert_socket(list, sk);
926
927out_unlock:
David S. Millerfbe9cc42005-12-13 23:26:29 -0800928 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929out_up:
Ingo Molnar57b47a52006-03-20 22:35:41 -0800930 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931out:
932 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933}
934
David S. Miller278a3de2007-05-31 15:19:20 -0700935static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
936{
937 if (unlikely(sk1 == sk2) || !sk2) {
938 unix_state_lock(sk1);
939 return;
940 }
941 if (sk1 < sk2) {
942 unix_state_lock(sk1);
943 unix_state_lock_nested(sk2);
944 } else {
945 unix_state_lock(sk2);
946 unix_state_lock_nested(sk1);
947 }
948}
949
950static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
951{
952 if (unlikely(sk1 == sk2) || !sk2) {
953 unix_state_unlock(sk1);
954 return;
955 }
956 unix_state_unlock(sk1);
957 unix_state_unlock(sk2);
958}
959
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
961 int alen, int flags)
962{
963 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900964 struct net *net = sock_net(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -0700965 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 struct sock *other;
Eric Dumazet95c96172012-04-15 05:58:06 +0000967 unsigned int hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 int err;
969
970 if (addr->sa_family != AF_UNSPEC) {
971 err = unix_mkname(sunaddr, alen, &hash);
972 if (err < 0)
973 goto out;
974 alen = err;
975
976 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
977 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
978 goto out;
979
David S. Miller278a3de2007-05-31 15:19:20 -0700980restart:
Jianjun Konge27dfce2008-11-01 21:38:31 -0700981 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 if (!other)
983 goto out;
984
David S. Miller278a3de2007-05-31 15:19:20 -0700985 unix_state_double_lock(sk, other);
986
987 /* Apparently VFS overslept socket death. Retry. */
988 if (sock_flag(other, SOCK_DEAD)) {
989 unix_state_double_unlock(sk, other);
990 sock_put(other);
991 goto restart;
992 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993
994 err = -EPERM;
995 if (!unix_may_send(sk, other))
996 goto out_unlock;
997
998 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
999 if (err)
1000 goto out_unlock;
1001
1002 } else {
1003 /*
1004 * 1003.1g breaking connected state with AF_UNSPEC
1005 */
1006 other = NULL;
David S. Miller278a3de2007-05-31 15:19:20 -07001007 unix_state_double_lock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 }
1009
1010 /*
1011 * If it was connected, reconnect.
1012 */
1013 if (unix_peer(sk)) {
1014 struct sock *old_peer = unix_peer(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001015 unix_peer(sk) = other;
David S. Miller278a3de2007-05-31 15:19:20 -07001016 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
1018 if (other != old_peer)
1019 unix_dgram_disconnected(sk, old_peer);
1020 sock_put(old_peer);
1021 } else {
Jianjun Konge27dfce2008-11-01 21:38:31 -07001022 unix_peer(sk) = other;
David S. Miller278a3de2007-05-31 15:19:20 -07001023 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 }
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001025 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
1027out_unlock:
David S. Miller278a3de2007-05-31 15:19:20 -07001028 unix_state_double_unlock(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 sock_put(other);
1030out:
1031 return err;
1032}
1033
1034static long unix_wait_for_peer(struct sock *other, long timeo)
1035{
1036 struct unix_sock *u = unix_sk(other);
1037 int sched;
1038 DEFINE_WAIT(wait);
1039
1040 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1041
1042 sched = !sock_flag(other, SOCK_DEAD) &&
1043 !(other->sk_shutdown & RCV_SHUTDOWN) &&
Rainer Weikusat3c734192008-06-17 22:28:05 -07001044 unix_recvq_full(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
David S. Miller1c92b4e2007-05-31 13:24:26 -07001046 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047
1048 if (sched)
1049 timeo = schedule_timeout(timeo);
1050
1051 finish_wait(&u->peer_wait, &wait);
1052 return timeo;
1053}
1054
1055static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1056 int addr_len, int flags)
1057{
Jianjun Konge27dfce2008-11-01 21:38:31 -07001058 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001060 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1062 struct sock *newsk = NULL;
1063 struct sock *other = NULL;
1064 struct sk_buff *skb = NULL;
Eric Dumazet95c96172012-04-15 05:58:06 +00001065 unsigned int hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 int st;
1067 int err;
1068 long timeo;
1069
1070 err = unix_mkname(sunaddr, addr_len, &hash);
1071 if (err < 0)
1072 goto out;
1073 addr_len = err;
1074
Joe Perchesf64f9e72009-11-29 16:55:45 -08001075 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
1076 (err = unix_autobind(sock)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 goto out;
1078
1079 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1080
1081 /* First of all allocate resources.
1082 If we will make it after state is locked,
1083 we will have to recheck all again in any case.
1084 */
1085
1086 err = -ENOMEM;
1087
1088 /* create new sock for complete connection */
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001089 newsk = unix_create1(sock_net(sk), NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 if (newsk == NULL)
1091 goto out;
1092
1093 /* Allocate skb for sending to listening sock */
1094 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1095 if (skb == NULL)
1096 goto out;
1097
1098restart:
1099 /* Find listening sock. */
Denis V. Lunev097e66c2007-11-19 22:29:30 -08001100 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 if (!other)
1102 goto out;
1103
1104 /* Latch state of peer */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001105 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106
1107 /* Apparently VFS overslept socket death. Retry. */
1108 if (sock_flag(other, SOCK_DEAD)) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001109 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 sock_put(other);
1111 goto restart;
1112 }
1113
1114 err = -ECONNREFUSED;
1115 if (other->sk_state != TCP_LISTEN)
1116 goto out_unlock;
Tomoki Sekiyama77238f22009-10-18 23:17:37 -07001117 if (other->sk_shutdown & RCV_SHUTDOWN)
1118 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119
Rainer Weikusat3c734192008-06-17 22:28:05 -07001120 if (unix_recvq_full(other)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 err = -EAGAIN;
1122 if (!timeo)
1123 goto out_unlock;
1124
1125 timeo = unix_wait_for_peer(other, timeo);
1126
1127 err = sock_intr_errno(timeo);
1128 if (signal_pending(current))
1129 goto out;
1130 sock_put(other);
1131 goto restart;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133
1134 /* Latch our state.
1135
Daniel Balutae5537bf2011-03-14 15:25:33 -07001136 It is tricky place. We need to grab our state lock and cannot
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 drop lock on peer. It is dangerous because deadlock is
1138 possible. Connect to self case and simultaneous
1139 attempt to connect are eliminated by checking socket
1140 state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1141 check this before attempt to grab lock.
1142
1143 Well, and we have to recheck the state after socket locked.
1144 */
1145 st = sk->sk_state;
1146
1147 switch (st) {
1148 case TCP_CLOSE:
1149 /* This is ok... continue with connect */
1150 break;
1151 case TCP_ESTABLISHED:
1152 /* Socket is already connected */
1153 err = -EISCONN;
1154 goto out_unlock;
1155 default:
1156 err = -EINVAL;
1157 goto out_unlock;
1158 }
1159
David S. Miller1c92b4e2007-05-31 13:24:26 -07001160 unix_state_lock_nested(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161
1162 if (sk->sk_state != st) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001163 unix_state_unlock(sk);
1164 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 sock_put(other);
1166 goto restart;
1167 }
1168
David S. Miller3610cda2011-01-05 15:38:53 -08001169 err = security_unix_stream_connect(sk, other, newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 if (err) {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001171 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 goto out_unlock;
1173 }
1174
1175 /* The way is open! Fastly set all the necessary fields... */
1176
1177 sock_hold(sk);
1178 unix_peer(newsk) = sk;
1179 newsk->sk_state = TCP_ESTABLISHED;
1180 newsk->sk_type = sk->sk_type;
Eric W. Biederman109f6e32010-06-13 03:30:14 +00001181 init_peercred(newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 newu = unix_sk(newsk);
Eric Dumazeteaefd112011-02-18 03:26:36 +00001183 RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 otheru = unix_sk(other);
1185
1186 /* copy address information from listening to new sock*/
1187 if (otheru->addr) {
1188 atomic_inc(&otheru->addr->refcnt);
1189 newu->addr = otheru->addr;
1190 }
Al Viro40ffe672012-03-14 21:54:32 -04001191 if (otheru->path.dentry) {
1192 path_get(&otheru->path);
1193 newu->path = otheru->path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 }
1195
1196 /* Set credentials */
Eric W. Biederman109f6e32010-06-13 03:30:14 +00001197 copy_peercred(sk, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 sock->state = SS_CONNECTED;
1200 sk->sk_state = TCP_ESTABLISHED;
Benjamin LaHaise830a1e52005-12-13 23:22:32 -08001201 sock_hold(newsk);
1202
1203 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
1204 unix_peer(sk) = newsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205
David S. Miller1c92b4e2007-05-31 13:24:26 -07001206 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207
1208 /* take ten and and send info to listening sock */
1209 spin_lock(&other->sk_receive_queue.lock);
1210 __skb_queue_tail(&other->sk_receive_queue, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 spin_unlock(&other->sk_receive_queue.lock);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001212 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 other->sk_data_ready(other, 0);
1214 sock_put(other);
1215 return 0;
1216
1217out_unlock:
1218 if (other)
David S. Miller1c92b4e2007-05-31 13:24:26 -07001219 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220
1221out:
Wei Yongjun40d44442009-02-25 00:32:45 +00001222 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 if (newsk)
1224 unix_release_sock(newsk, 0);
1225 if (other)
1226 sock_put(other);
1227 return err;
1228}
1229
1230static int unix_socketpair(struct socket *socka, struct socket *sockb)
1231{
Jianjun Konge27dfce2008-11-01 21:38:31 -07001232 struct sock *ska = socka->sk, *skb = sockb->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233
1234 /* Join our sockets back to back */
1235 sock_hold(ska);
1236 sock_hold(skb);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001237 unix_peer(ska) = skb;
1238 unix_peer(skb) = ska;
Eric W. Biederman109f6e32010-06-13 03:30:14 +00001239 init_peercred(ska);
1240 init_peercred(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241
1242 if (ska->sk_type != SOCK_DGRAM) {
1243 ska->sk_state = TCP_ESTABLISHED;
1244 skb->sk_state = TCP_ESTABLISHED;
1245 socka->state = SS_CONNECTED;
1246 sockb->state = SS_CONNECTED;
1247 }
1248 return 0;
1249}
1250
1251static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1252{
1253 struct sock *sk = sock->sk;
1254 struct sock *tsk;
1255 struct sk_buff *skb;
1256 int err;
1257
1258 err = -EOPNOTSUPP;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001259 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 goto out;
1261
1262 err = -EINVAL;
1263 if (sk->sk_state != TCP_LISTEN)
1264 goto out;
1265
1266 /* If socket state is TCP_LISTEN it cannot change (for now...),
1267 * so that no locks are necessary.
1268 */
1269
1270 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1271 if (!skb) {
1272 /* This means receive shutdown. */
1273 if (err == 0)
1274 err = -EINVAL;
1275 goto out;
1276 }
1277
1278 tsk = skb->sk;
1279 skb_free_datagram(sk, skb);
1280 wake_up_interruptible(&unix_sk(sk)->peer_wait);
1281
1282 /* attach accepted sock to socket */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001283 unix_state_lock(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284 newsock->state = SS_CONNECTED;
1285 sock_graft(tsk, newsock);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001286 unix_state_unlock(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 return 0;
1288
1289out:
1290 return err;
1291}
1292
1293
1294static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1295{
1296 struct sock *sk = sock->sk;
1297 struct unix_sock *u;
Cyrill Gorcunov13cfa972009-11-08 05:51:19 +00001298 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 int err = 0;
1300
1301 if (peer) {
1302 sk = unix_peer_get(sk);
1303
1304 err = -ENOTCONN;
1305 if (!sk)
1306 goto out;
1307 err = 0;
1308 } else {
1309 sock_hold(sk);
1310 }
1311
1312 u = unix_sk(sk);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001313 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 if (!u->addr) {
1315 sunaddr->sun_family = AF_UNIX;
1316 sunaddr->sun_path[0] = 0;
1317 *uaddr_len = sizeof(short);
1318 } else {
1319 struct unix_address *addr = u->addr;
1320
1321 *uaddr_len = addr->len;
1322 memcpy(sunaddr, addr->name, *uaddr_len);
1323 }
David S. Miller1c92b4e2007-05-31 13:24:26 -07001324 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 sock_put(sk);
1326out:
1327 return err;
1328}
1329
1330static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1331{
1332 int i;
1333
1334 scm->fp = UNIXCB(skb).fp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 UNIXCB(skb).fp = NULL;
1336
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001337 for (i = scm->fp->count-1; i >= 0; i--)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 unix_notinflight(scm->fp->fp[i]);
1339}
1340
Eric W. Biederman7361c362010-06-13 03:34:33 +00001341static void unix_destruct_scm(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342{
1343 struct scm_cookie scm;
1344 memset(&scm, 0, sizeof(scm));
Eric W. Biederman7361c362010-06-13 03:34:33 +00001345 scm.pid = UNIXCB(skb).pid;
1346 scm.cred = UNIXCB(skb).cred;
1347 if (UNIXCB(skb).fp)
1348 unix_detach_fds(&scm, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349
1350 /* Alas, it calls VFS */
1351 /* So fscking what? fput() had been SMP-safe since the last Summer */
1352 scm_destroy(&scm);
1353 sock_wfree(skb);
1354}
1355
Eric Dumazet25888e32010-11-25 04:11:39 +00001356#define MAX_RECURSION_LEVEL 4
1357
Miklos Szeredi62093442008-11-09 15:23:57 +01001358static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359{
1360 int i;
Eric Dumazet25888e32010-11-25 04:11:39 +00001361 unsigned char max_level = 0;
1362 int unix_sock_count = 0;
1363
1364 for (i = scm->fp->count - 1; i >= 0; i--) {
1365 struct sock *sk = unix_get_socket(scm->fp->fp[i]);
1366
1367 if (sk) {
1368 unix_sock_count++;
1369 max_level = max(max_level,
1370 unix_sk(sk)->recursion_level);
1371 }
1372 }
1373 if (unlikely(max_level > MAX_RECURSION_LEVEL))
1374 return -ETOOMANYREFS;
Miklos Szeredi62093442008-11-09 15:23:57 +01001375
1376 /*
1377 * Need to duplicate file references for the sake of garbage
1378 * collection. Otherwise a socket in the fps might become a
1379 * candidate for GC while the skb is not yet queued.
1380 */
1381 UNIXCB(skb).fp = scm_fp_dup(scm->fp);
1382 if (!UNIXCB(skb).fp)
1383 return -ENOMEM;
1384
Eric Dumazet25888e32010-11-25 04:11:39 +00001385 if (unix_sock_count) {
1386 for (i = scm->fp->count - 1; i >= 0; i--)
1387 unix_inflight(scm->fp->fp[i]);
1388 }
1389 return max_level;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001390}
1391
David S. Millerf78a5fd2011-09-16 19:34:00 -04001392static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
Eric W. Biederman7361c362010-06-13 03:34:33 +00001393{
1394 int err = 0;
Eric Dumazet16e57262011-09-19 05:52:27 +00001395
David S. Millerf78a5fd2011-09-16 19:34:00 -04001396 UNIXCB(skb).pid = get_pid(scm->pid);
Eric Dumazet16e57262011-09-19 05:52:27 +00001397 if (scm->cred)
1398 UNIXCB(skb).cred = get_cred(scm->cred);
Eric W. Biederman7361c362010-06-13 03:34:33 +00001399 UNIXCB(skb).fp = NULL;
1400 if (scm->fp && send_fds)
1401 err = unix_attach_fds(scm, skb);
1402
1403 skb->destructor = unix_destruct_scm;
1404 return err;
1405}
1406
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407/*
Eric Dumazet16e57262011-09-19 05:52:27 +00001408 * Some apps rely on write() giving SCM_CREDENTIALS
1409 * We include credentials if source or destination socket
1410 * asserted SOCK_PASSCRED.
1411 */
1412static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
1413 const struct sock *other)
1414{
1415 if (UNIXCB(skb).cred)
1416 return;
1417 if (test_bit(SOCK_PASSCRED, &sock->flags) ||
1418 !other->sk_socket ||
1419 test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
1420 UNIXCB(skb).pid = get_pid(task_tgid(current));
1421 UNIXCB(skb).cred = get_current_cred();
1422 }
1423}
1424
1425/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426 * Send AF_UNIX data.
1427 */
1428
1429static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1430 struct msghdr *msg, size_t len)
1431{
1432 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1433 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001434 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001436 struct sockaddr_un *sunaddr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437 struct sock *other = NULL;
1438 int namelen = 0; /* fake GCC */
1439 int err;
Eric Dumazet95c96172012-04-15 05:58:06 +00001440 unsigned int hash;
David S. Millerf78a5fd2011-09-16 19:34:00 -04001441 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 long timeo;
1443 struct scm_cookie tmp_scm;
Eric Dumazet25888e32010-11-25 04:11:39 +00001444 int max_level;
Eric Dumazeteb6a2482012-04-03 05:28:28 +00001445 int data_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446
1447 if (NULL == siocb->scm)
1448 siocb->scm = &tmp_scm;
dann frazier5f23b732008-11-26 15:32:27 -08001449 wait_for_unix_gc();
Eric Dumazete0e3cea2012-08-21 06:21:17 +00001450 err = scm_send(sock, msg, siocb->scm, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 if (err < 0)
1452 return err;
1453
1454 err = -EOPNOTSUPP;
1455 if (msg->msg_flags&MSG_OOB)
1456 goto out;
1457
1458 if (msg->msg_namelen) {
1459 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1460 if (err < 0)
1461 goto out;
1462 namelen = err;
1463 } else {
1464 sunaddr = NULL;
1465 err = -ENOTCONN;
1466 other = unix_peer_get(sk);
1467 if (!other)
1468 goto out;
1469 }
1470
Joe Perchesf64f9e72009-11-29 16:55:45 -08001471 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
1472 && (err = unix_autobind(sock)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473 goto out;
1474
1475 err = -EMSGSIZE;
1476 if (len > sk->sk_sndbuf - 32)
1477 goto out;
1478
Eric Dumazeteb6a2482012-04-03 05:28:28 +00001479 if (len > SKB_MAX_ALLOC)
1480 data_len = min_t(size_t,
1481 len - SKB_MAX_ALLOC,
1482 MAX_SKB_FRAGS * PAGE_SIZE);
1483
1484 skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
1485 msg->msg_flags & MSG_DONTWAIT, &err);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001486 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 goto out;
1488
David S. Millerf78a5fd2011-09-16 19:34:00 -04001489 err = unix_scm_to_skb(siocb->scm, skb, true);
Eric Dumazet25888e32010-11-25 04:11:39 +00001490 if (err < 0)
Eric W. Biederman7361c362010-06-13 03:34:33 +00001491 goto out_free;
Eric Dumazet25888e32010-11-25 04:11:39 +00001492 max_level = err + 1;
Catherine Zhangdc49c1f2006-08-02 14:12:06 -07001493 unix_get_secdata(siocb->scm, skb);
Catherine Zhang877ce7c2006-06-29 12:27:47 -07001494
Eric Dumazeteb6a2482012-04-03 05:28:28 +00001495 skb_put(skb, len - data_len);
1496 skb->data_len = data_len;
1497 skb->len = len;
1498 err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 if (err)
1500 goto out_free;
1501
1502 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1503
1504restart:
1505 if (!other) {
1506 err = -ECONNRESET;
1507 if (sunaddr == NULL)
1508 goto out_free;
1509
Denis V. Lunev097e66c2007-11-19 22:29:30 -08001510 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 hash, &err);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001512 if (other == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513 goto out_free;
1514 }
1515
Alban Crequyd6ae3ba2011-01-18 06:39:15 +00001516 if (sk_filter(other, skb) < 0) {
1517 /* Toss the packet but do not return any error to the sender */
1518 err = len;
1519 goto out_free;
1520 }
1521
David S. Miller1c92b4e2007-05-31 13:24:26 -07001522 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 err = -EPERM;
1524 if (!unix_may_send(sk, other))
1525 goto out_unlock;
1526
1527 if (sock_flag(other, SOCK_DEAD)) {
1528 /*
1529 * Check with 1003.1g - what should
1530 * datagram error
1531 */
David S. Miller1c92b4e2007-05-31 13:24:26 -07001532 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 sock_put(other);
1534
1535 err = 0;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001536 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 if (unix_peer(sk) == other) {
Jianjun Konge27dfce2008-11-01 21:38:31 -07001538 unix_peer(sk) = NULL;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001539 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540
1541 unix_dgram_disconnected(sk, other);
1542 sock_put(other);
1543 err = -ECONNREFUSED;
1544 } else {
David S. Miller1c92b4e2007-05-31 13:24:26 -07001545 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 }
1547
1548 other = NULL;
1549 if (err)
1550 goto out_free;
1551 goto restart;
1552 }
1553
1554 err = -EPIPE;
1555 if (other->sk_shutdown & RCV_SHUTDOWN)
1556 goto out_unlock;
1557
1558 if (sk->sk_type != SOCK_SEQPACKET) {
1559 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1560 if (err)
1561 goto out_unlock;
1562 }
1563
Rainer Weikusat3c734192008-06-17 22:28:05 -07001564 if (unix_peer(other) != sk && unix_recvq_full(other)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 if (!timeo) {
1566 err = -EAGAIN;
1567 goto out_unlock;
1568 }
1569
1570 timeo = unix_wait_for_peer(other, timeo);
1571
1572 err = sock_intr_errno(timeo);
1573 if (signal_pending(current))
1574 goto out_free;
1575
1576 goto restart;
1577 }
1578
Alban Crequy3f661162010-10-04 08:48:28 +00001579 if (sock_flag(other, SOCK_RCVTSTAMP))
1580 __net_timestamp(skb);
Eric Dumazet16e57262011-09-19 05:52:27 +00001581 maybe_add_creds(skb, sock, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 skb_queue_tail(&other->sk_receive_queue, skb);
Eric Dumazet25888e32010-11-25 04:11:39 +00001583 if (max_level > unix_sk(other)->recursion_level)
1584 unix_sk(other)->recursion_level = max_level;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001585 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 other->sk_data_ready(other, len);
1587 sock_put(other);
David S. Millerf78a5fd2011-09-16 19:34:00 -04001588 scm_destroy(siocb->scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589 return len;
1590
1591out_unlock:
David S. Miller1c92b4e2007-05-31 13:24:26 -07001592 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001593out_free:
1594 kfree_skb(skb);
1595out:
1596 if (other)
1597 sock_put(other);
David S. Millerf78a5fd2011-09-16 19:34:00 -04001598 scm_destroy(siocb->scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 return err;
1600}
1601
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001602
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1604 struct msghdr *msg, size_t len)
1605{
1606 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1607 struct sock *sk = sock->sk;
1608 struct sock *other = NULL;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001609 int err, size;
David S. Millerf78a5fd2011-09-16 19:34:00 -04001610 struct sk_buff *skb;
Jianjun Konge27dfce2008-11-01 21:38:31 -07001611 int sent = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 struct scm_cookie tmp_scm;
Miklos Szeredi8ba69ba2009-09-11 11:31:45 -07001613 bool fds_sent = false;
Eric Dumazet25888e32010-11-25 04:11:39 +00001614 int max_level;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615
1616 if (NULL == siocb->scm)
1617 siocb->scm = &tmp_scm;
dann frazier5f23b732008-11-26 15:32:27 -08001618 wait_for_unix_gc();
Eric Dumazete0e3cea2012-08-21 06:21:17 +00001619 err = scm_send(sock, msg, siocb->scm, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 if (err < 0)
1621 return err;
1622
1623 err = -EOPNOTSUPP;
1624 if (msg->msg_flags&MSG_OOB)
1625 goto out_err;
1626
1627 if (msg->msg_namelen) {
1628 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1629 goto out_err;
1630 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 err = -ENOTCONN;
Benjamin LaHaise830a1e52005-12-13 23:22:32 -08001632 other = unix_peer(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 if (!other)
1634 goto out_err;
1635 }
1636
1637 if (sk->sk_shutdown & SEND_SHUTDOWN)
1638 goto pipe_err;
1639
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001640 while (sent < len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641 /*
Benjamin LaHaisee9df7d7f2006-03-20 21:29:05 -08001642 * Optimisation for the fact that under 0.01% of X
1643 * messages typically need breaking up.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001644 */
1645
Benjamin LaHaisee9df7d7f2006-03-20 21:29:05 -08001646 size = len-sent;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647
1648 /* Keep two messages in the pipe so it schedules better */
Benjamin LaHaisee9df7d7f2006-03-20 21:29:05 -08001649 if (size > ((sk->sk_sndbuf >> 1) - 64))
1650 size = (sk->sk_sndbuf >> 1) - 64;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651
1652 if (size > SKB_MAX_ALLOC)
1653 size = SKB_MAX_ALLOC;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001654
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655 /*
1656 * Grab a buffer
1657 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001658
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001659 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT,
1660 &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661
Jianjun Konge27dfce2008-11-01 21:38:31 -07001662 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 goto out_err;
1664
1665 /*
1666 * If you pass two values to the sock_alloc_send_skb
1667 * it tries to grab the large buffer with GFP_NOFS
1668 * (which can fail easily), and if it fails grab the
1669 * fallback size buffer which is under a page and will
1670 * succeed. [Alan]
1671 */
1672 size = min_t(int, size, skb_tailroom(skb));
1673
Eric W. Biederman7361c362010-06-13 03:34:33 +00001674
David S. Millerf78a5fd2011-09-16 19:34:00 -04001675 /* Only send the fds in the first buffer */
1676 err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
Eric Dumazet25888e32010-11-25 04:11:39 +00001677 if (err < 0) {
Eric W. Biederman7361c362010-06-13 03:34:33 +00001678 kfree_skb(skb);
David S. Millerf78a5fd2011-09-16 19:34:00 -04001679 goto out_err;
Miklos Szeredi62093442008-11-09 15:23:57 +01001680 }
Eric Dumazet25888e32010-11-25 04:11:39 +00001681 max_level = err + 1;
Eric W. Biederman7361c362010-06-13 03:34:33 +00001682 fds_sent = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001684 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
1685 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 kfree_skb(skb);
David S. Millerf78a5fd2011-09-16 19:34:00 -04001687 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001688 }
1689
David S. Miller1c92b4e2007-05-31 13:24:26 -07001690 unix_state_lock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691
1692 if (sock_flag(other, SOCK_DEAD) ||
1693 (other->sk_shutdown & RCV_SHUTDOWN))
1694 goto pipe_err_free;
1695
Eric Dumazet16e57262011-09-19 05:52:27 +00001696 maybe_add_creds(skb, sock, other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 skb_queue_tail(&other->sk_receive_queue, skb);
Eric Dumazet25888e32010-11-25 04:11:39 +00001698 if (max_level > unix_sk(other)->recursion_level)
1699 unix_sk(other)->recursion_level = max_level;
David S. Miller1c92b4e2007-05-31 13:24:26 -07001700 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 other->sk_data_ready(other, size);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001702 sent += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704
David S. Millerf78a5fd2011-09-16 19:34:00 -04001705 scm_destroy(siocb->scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 siocb->scm = NULL;
1707
1708 return sent;
1709
1710pipe_err_free:
David S. Miller1c92b4e2007-05-31 13:24:26 -07001711 unix_state_unlock(other);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 kfree_skb(skb);
1713pipe_err:
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001714 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
1715 send_sig(SIGPIPE, current, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 err = -EPIPE;
1717out_err:
David S. Millerf78a5fd2011-09-16 19:34:00 -04001718 scm_destroy(siocb->scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 siocb->scm = NULL;
1720 return sent ? : err;
1721}
1722
1723static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1724 struct msghdr *msg, size_t len)
1725{
1726 int err;
1727 struct sock *sk = sock->sk;
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001728
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 err = sock_error(sk);
1730 if (err)
1731 return err;
1732
1733 if (sk->sk_state != TCP_ESTABLISHED)
1734 return -ENOTCONN;
1735
1736 if (msg->msg_namelen)
1737 msg->msg_namelen = 0;
1738
1739 return unix_dgram_sendmsg(kiocb, sock, msg, len);
1740}
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001741
Eric W. Biedermana05d2ad2011-04-24 01:54:57 +00001742static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock,
1743 struct msghdr *msg, size_t size,
1744 int flags)
1745{
1746 struct sock *sk = sock->sk;
1747
1748 if (sk->sk_state != TCP_ESTABLISHED)
1749 return -ENOTCONN;
1750
1751 return unix_dgram_recvmsg(iocb, sock, msg, size, flags);
1752}
1753
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1755{
1756 struct unix_sock *u = unix_sk(sk);
1757
1758 msg->msg_namelen = 0;
1759 if (u->addr) {
1760 msg->msg_namelen = u->addr->len;
1761 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1762 }
1763}
1764
1765static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1766 struct msghdr *msg, size_t size,
1767 int flags)
1768{
1769 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1770 struct scm_cookie tmp_scm;
1771 struct sock *sk = sock->sk;
1772 struct unix_sock *u = unix_sk(sk);
1773 int noblock = flags & MSG_DONTWAIT;
1774 struct sk_buff *skb;
1775 int err;
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001776 int peeked, skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777
1778 err = -EOPNOTSUPP;
1779 if (flags&MSG_OOB)
1780 goto out;
1781
1782 msg->msg_namelen = 0;
1783
Rainer Weikusatb3ca9b02011-02-28 04:50:55 +00001784 err = mutex_lock_interruptible(&u->readlock);
1785 if (err) {
1786 err = sock_intr_errno(sock_rcvtimeo(sk, noblock));
1787 goto out;
1788 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001790 skip = sk_peek_offset(sk, flags);
1791
1792 skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err);
Florian Zumbiehl0a112252007-11-29 23:19:23 +11001793 if (!skb) {
1794 unix_state_lock(sk);
1795 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1796 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1797 (sk->sk_shutdown & RCV_SHUTDOWN))
1798 err = 0;
1799 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 goto out_unlock;
Florian Zumbiehl0a112252007-11-29 23:19:23 +11001801 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802
Eric Dumazet67426b72010-10-29 20:44:44 +00001803 wake_up_interruptible_sync_poll(&u->peer_wait,
1804 POLLOUT | POLLWRNORM | POLLWRBAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805
1806 if (msg->msg_name)
1807 unix_copy_addr(msg, skb->sk);
1808
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001809 if (size > skb->len - skip)
1810 size = skb->len - skip;
1811 else if (size < skb->len - skip)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 msg->msg_flags |= MSG_TRUNC;
1813
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001814 err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001815 if (err)
1816 goto out_free;
1817
Alban Crequy3f661162010-10-04 08:48:28 +00001818 if (sock_flag(sk, SOCK_RCVTSTAMP))
1819 __sock_recv_timestamp(msg, sk, skb);
1820
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821 if (!siocb->scm) {
1822 siocb->scm = &tmp_scm;
1823 memset(&tmp_scm, 0, sizeof(tmp_scm));
1824 }
David S. Millerf78a5fd2011-09-16 19:34:00 -04001825 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
Catherine Zhang877ce7c2006-06-29 12:27:47 -07001826 unix_set_secdata(siocb->scm, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001828 if (!(flags & MSG_PEEK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001829 if (UNIXCB(skb).fp)
1830 unix_detach_fds(siocb->scm, skb);
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001831
1832 sk_peek_offset_bwd(sk, skb->len);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001833 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 /* It is questionable: on PEEK we could:
1835 - do not return fds - good, but too simple 8)
1836 - return fds, and do not return them on read (old strategy,
1837 apparently wrong)
1838 - clone fds (I chose it for now, it is the most universal
1839 solution)
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001840
1841 POSIX 1003.1g does not actually define this clearly
1842 at all. POSIX 1003.1g doesn't define a lot of things
1843 clearly however!
1844
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845 */
Pavel Emelyanovf55bb7f2012-02-21 07:31:51 +00001846
1847 sk_peek_offset_fwd(sk, size);
1848
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 if (UNIXCB(skb).fp)
1850 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1851 }
Eric Dumazet9f6f9af2012-02-21 23:24:55 +00001852 err = (flags & MSG_TRUNC) ? skb->len - skip : size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853
1854 scm_recv(sock, msg, siocb->scm, flags);
1855
1856out_free:
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001857 skb_free_datagram(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858out_unlock:
Ingo Molnar57b47a52006-03-20 22:35:41 -08001859 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860out:
1861 return err;
1862}
1863
1864/*
1865 * Sleep until data has arrive. But check for races..
1866 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001867
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001868static long unix_stream_data_wait(struct sock *sk, long timeo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869{
1870 DEFINE_WAIT(wait);
1871
David S. Miller1c92b4e2007-05-31 13:24:26 -07001872 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873
1874 for (;;) {
Eric Dumazetaa395142010-04-20 13:03:51 +00001875 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876
David S. Millerb03efcf2005-07-08 14:57:23 -07001877 if (!skb_queue_empty(&sk->sk_receive_queue) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878 sk->sk_err ||
1879 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1880 signal_pending(current) ||
1881 !timeo)
1882 break;
1883
1884 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001885 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886 timeo = schedule_timeout(timeo);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001887 unix_state_lock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1889 }
1890
Eric Dumazetaa395142010-04-20 13:03:51 +00001891 finish_wait(sk_sleep(sk), &wait);
David S. Miller1c92b4e2007-05-31 13:24:26 -07001892 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893 return timeo;
1894}
1895
1896
1897
1898static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1899 struct msghdr *msg, size_t size,
1900 int flags)
1901{
1902 struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1903 struct scm_cookie tmp_scm;
1904 struct sock *sk = sock->sk;
1905 struct unix_sock *u = unix_sk(sk);
Jianjun Konge27dfce2008-11-01 21:38:31 -07001906 struct sockaddr_un *sunaddr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 int copied = 0;
1908 int check_creds = 0;
1909 int target;
1910 int err = 0;
1911 long timeo;
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00001912 int skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913
1914 err = -EINVAL;
1915 if (sk->sk_state != TCP_ESTABLISHED)
1916 goto out;
1917
1918 err = -EOPNOTSUPP;
1919 if (flags&MSG_OOB)
1920 goto out;
1921
1922 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1923 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1924
1925 msg->msg_namelen = 0;
1926
1927 /* Lock the socket to prevent queue disordering
1928 * while sleeps in memcpy_tomsg
1929 */
1930
1931 if (!siocb->scm) {
1932 siocb->scm = &tmp_scm;
1933 memset(&tmp_scm, 0, sizeof(tmp_scm));
1934 }
1935
Rainer Weikusatb3ca9b02011-02-28 04:50:55 +00001936 err = mutex_lock_interruptible(&u->readlock);
1937 if (err) {
1938 err = sock_intr_errno(timeo);
1939 goto out;
1940 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001941
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00001942 skip = sk_peek_offset(sk, flags);
1943
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001944 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945 int chunk;
1946 struct sk_buff *skb;
1947
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001948 unix_state_lock(sk);
Eric Dumazet6f01fd62012-01-28 16:11:03 +00001949 skb = skb_peek(&sk->sk_receive_queue);
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00001950again:
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001951 if (skb == NULL) {
Eric Dumazet25888e32010-11-25 04:11:39 +00001952 unix_sk(sk)->recursion_level = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953 if (copied >= target)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001954 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001955
1956 /*
1957 * POSIX 1003.1g mandates this order.
1958 */
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09001959
Eric Dumazet6eba6a32008-11-16 22:58:44 -08001960 err = sock_error(sk);
1961 if (err)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001962 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001963 if (sk->sk_shutdown & RCV_SHUTDOWN)
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001964 goto unlock;
1965
1966 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967 err = -EAGAIN;
1968 if (!timeo)
1969 break;
Ingo Molnar57b47a52006-03-20 22:35:41 -08001970 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001971
1972 timeo = unix_stream_data_wait(sk, timeo);
1973
Rainer Weikusatb3ca9b02011-02-28 04:50:55 +00001974 if (signal_pending(current)
1975 || mutex_lock_interruptible(&u->readlock)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 err = sock_intr_errno(timeo);
1977 goto out;
1978 }
Rainer Weikusatb3ca9b02011-02-28 04:50:55 +00001979
Linus Torvalds1da177e2005-04-16 15:20:36 -07001980 continue;
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001981 unlock:
1982 unix_state_unlock(sk);
1983 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 }
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00001985
1986 if (skip >= skb->len) {
1987 skip -= skb->len;
1988 skb = skb_peek_next(skb, &sk->sk_receive_queue);
1989 goto again;
1990 }
1991
Miklos Szeredi3c0d2f32007-06-05 13:10:29 -07001992 unix_state_unlock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001993
1994 if (check_creds) {
1995 /* Never glue messages from different writers */
Eric W. Biederman7361c362010-06-13 03:34:33 +00001996 if ((UNIXCB(skb).pid != siocb->scm->pid) ||
Eric Dumazet6f01fd62012-01-28 16:11:03 +00001997 (UNIXCB(skb).cred != siocb->scm->cred))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 } else {
2000 /* Copy credentials */
David S. Millerf78a5fd2011-09-16 19:34:00 -04002001 scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002 check_creds = 1;
2003 }
2004
2005 /* Copy address just once */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002006 if (sunaddr) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002007 unix_copy_addr(msg, skb->sk);
2008 sunaddr = NULL;
2009 }
2010
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00002011 chunk = min_t(unsigned int, skb->len - skip, size);
2012 if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002013 if (copied == 0)
2014 copied = -EFAULT;
2015 break;
2016 }
2017 copied += chunk;
2018 size -= chunk;
2019
2020 /* Mark read part of skb as used */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002021 if (!(flags & MSG_PEEK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002022 skb_pull(skb, chunk);
2023
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00002024 sk_peek_offset_bwd(sk, chunk);
2025
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026 if (UNIXCB(skb).fp)
2027 unix_detach_fds(siocb->scm, skb);
2028
Eric Dumazet6f01fd62012-01-28 16:11:03 +00002029 if (skb->len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031
Eric Dumazet6f01fd62012-01-28 16:11:03 +00002032 skb_unlink(skb, &sk->sk_receive_queue);
Neil Horman70d4bf62010-07-20 06:45:56 +00002033 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002034
2035 if (siocb->scm->fp)
2036 break;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002037 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038 /* It is questionable, see note in unix_dgram_recvmsg.
2039 */
2040 if (UNIXCB(skb).fp)
2041 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
2042
Pavel Emelyanovfc0d7532012-02-21 07:32:06 +00002043 sk_peek_offset_fwd(sk, chunk);
2044
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045 break;
2046 }
2047 } while (size);
2048
Ingo Molnar57b47a52006-03-20 22:35:41 -08002049 mutex_unlock(&u->readlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 scm_recv(sock, msg, siocb->scm, flags);
2051out:
2052 return copied ? : err;
2053}
2054
2055static int unix_shutdown(struct socket *sock, int mode)
2056{
2057 struct sock *sk = sock->sk;
2058 struct sock *other;
2059
Xi Wangfc61b922012-08-26 16:47:13 +00002060 if (mode < SHUT_RD || mode > SHUT_RDWR)
2061 return -EINVAL;
2062 /* This maps:
2063 * SHUT_RD (0) -> RCV_SHUTDOWN (1)
2064 * SHUT_WR (1) -> SEND_SHUTDOWN (2)
2065 * SHUT_RDWR (2) -> SHUTDOWN_MASK (3)
2066 */
2067 ++mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068
Alban Crequy7180a032011-01-19 04:56:36 +00002069 unix_state_lock(sk);
2070 sk->sk_shutdown |= mode;
2071 other = unix_peer(sk);
2072 if (other)
2073 sock_hold(other);
2074 unix_state_unlock(sk);
2075 sk->sk_state_change(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076
Alban Crequy7180a032011-01-19 04:56:36 +00002077 if (other &&
2078 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079
Alban Crequy7180a032011-01-19 04:56:36 +00002080 int peer_mode = 0;
2081
2082 if (mode&RCV_SHUTDOWN)
2083 peer_mode |= SEND_SHUTDOWN;
2084 if (mode&SEND_SHUTDOWN)
2085 peer_mode |= RCV_SHUTDOWN;
2086 unix_state_lock(other);
2087 other->sk_shutdown |= peer_mode;
2088 unix_state_unlock(other);
2089 other->sk_state_change(other);
2090 if (peer_mode == SHUTDOWN_MASK)
2091 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
2092 else if (peer_mode & RCV_SHUTDOWN)
2093 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094 }
Alban Crequy7180a032011-01-19 04:56:36 +00002095 if (other)
2096 sock_put(other);
2097
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098 return 0;
2099}
2100
Pavel Emelyanov885ee742011-12-30 00:54:11 +00002101long unix_inq_len(struct sock *sk)
2102{
2103 struct sk_buff *skb;
2104 long amount = 0;
2105
2106 if (sk->sk_state == TCP_LISTEN)
2107 return -EINVAL;
2108
2109 spin_lock(&sk->sk_receive_queue.lock);
2110 if (sk->sk_type == SOCK_STREAM ||
2111 sk->sk_type == SOCK_SEQPACKET) {
2112 skb_queue_walk(&sk->sk_receive_queue, skb)
2113 amount += skb->len;
2114 } else {
2115 skb = skb_peek(&sk->sk_receive_queue);
2116 if (skb)
2117 amount = skb->len;
2118 }
2119 spin_unlock(&sk->sk_receive_queue.lock);
2120
2121 return amount;
2122}
2123EXPORT_SYMBOL_GPL(unix_inq_len);
2124
2125long unix_outq_len(struct sock *sk)
2126{
2127 return sk_wmem_alloc_get(sk);
2128}
2129EXPORT_SYMBOL_GPL(unix_outq_len);
2130
Linus Torvalds1da177e2005-04-16 15:20:36 -07002131static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2132{
2133 struct sock *sk = sock->sk;
Jianjun Konge27dfce2008-11-01 21:38:31 -07002134 long amount = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 int err;
2136
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002137 switch (cmd) {
2138 case SIOCOUTQ:
Pavel Emelyanov885ee742011-12-30 00:54:11 +00002139 amount = unix_outq_len(sk);
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002140 err = put_user(amount, (int __user *)arg);
2141 break;
2142 case SIOCINQ:
Pavel Emelyanov885ee742011-12-30 00:54:11 +00002143 amount = unix_inq_len(sk);
2144 if (amount < 0)
2145 err = amount;
2146 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002147 err = put_user(amount, (int __user *)arg);
Pavel Emelyanov885ee742011-12-30 00:54:11 +00002148 break;
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002149 default:
2150 err = -ENOIOCTLCMD;
2151 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 }
2153 return err;
2154}
2155
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002156static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157{
2158 struct sock *sk = sock->sk;
2159 unsigned int mask;
2160
Eric Dumazetaa395142010-04-20 13:03:51 +00002161 sock_poll_wait(file, sk_sleep(sk), wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 mask = 0;
2163
2164 /* exceptional events? */
2165 if (sk->sk_err)
2166 mask |= POLLERR;
2167 if (sk->sk_shutdown == SHUTDOWN_MASK)
2168 mask |= POLLHUP;
Davide Libenzif348d702006-03-25 03:07:39 -08002169 if (sk->sk_shutdown & RCV_SHUTDOWN)
Eric Dumazetdb409802010-09-06 11:13:50 +00002170 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171
2172 /* readable? */
Eric Dumazetdb409802010-09-06 11:13:50 +00002173 if (!skb_queue_empty(&sk->sk_receive_queue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174 mask |= POLLIN | POLLRDNORM;
2175
2176 /* Connection-based need to check for termination and startup */
Eric Dumazet6eba6a32008-11-16 22:58:44 -08002177 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
2178 sk->sk_state == TCP_CLOSE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179 mask |= POLLHUP;
2180
2181 /*
2182 * we set writable also when the other side has shut down the
2183 * connection. This prevents stuck sockets.
2184 */
2185 if (unix_writable(sk))
2186 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2187
2188 return mask;
2189}
2190
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002191static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
2192 poll_table *wait)
Rainer Weikusat3c734192008-06-17 22:28:05 -07002193{
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002194 struct sock *sk = sock->sk, *other;
2195 unsigned int mask, writable;
Rainer Weikusat3c734192008-06-17 22:28:05 -07002196
Eric Dumazetaa395142010-04-20 13:03:51 +00002197 sock_poll_wait(file, sk_sleep(sk), wait);
Rainer Weikusat3c734192008-06-17 22:28:05 -07002198 mask = 0;
2199
2200 /* exceptional events? */
2201 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
2202 mask |= POLLERR;
2203 if (sk->sk_shutdown & RCV_SHUTDOWN)
Eric Dumazet5456f092010-10-31 05:36:23 +00002204 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
Rainer Weikusat3c734192008-06-17 22:28:05 -07002205 if (sk->sk_shutdown == SHUTDOWN_MASK)
2206 mask |= POLLHUP;
2207
2208 /* readable? */
Eric Dumazet5456f092010-10-31 05:36:23 +00002209 if (!skb_queue_empty(&sk->sk_receive_queue))
Rainer Weikusat3c734192008-06-17 22:28:05 -07002210 mask |= POLLIN | POLLRDNORM;
2211
2212 /* Connection-based need to check for termination and startup */
2213 if (sk->sk_type == SOCK_SEQPACKET) {
2214 if (sk->sk_state == TCP_CLOSE)
2215 mask |= POLLHUP;
2216 /* connection hasn't started yet? */
2217 if (sk->sk_state == TCP_SYN_SENT)
2218 return mask;
2219 }
2220
Eric Dumazet973a34a2010-10-31 05:38:25 +00002221 /* No write status requested, avoid expensive OUT tests. */
Hans Verkuil626cf232012-03-23 15:02:27 -07002222 if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT)))
Eric Dumazet973a34a2010-10-31 05:38:25 +00002223 return mask;
2224
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002225 writable = unix_writable(sk);
Eric Dumazet5456f092010-10-31 05:36:23 +00002226 other = unix_peer_get(sk);
2227 if (other) {
2228 if (unix_peer(other) != sk) {
2229 sock_poll_wait(file, &unix_sk(other)->peer_wait, wait);
2230 if (unix_recvq_full(other))
2231 writable = 0;
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002232 }
Eric Dumazet5456f092010-10-31 05:36:23 +00002233 sock_put(other);
Rainer Weikusatec0d2152008-06-27 19:34:18 -07002234 }
2235
2236 if (writable)
Rainer Weikusat3c734192008-06-17 22:28:05 -07002237 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2238 else
2239 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
2240
Rainer Weikusat3c734192008-06-17 22:28:05 -07002241 return mask;
2242}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002243
2244#ifdef CONFIG_PROC_FS
Pavel Emelyanova53eb3f2007-11-23 20:30:01 +08002245
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002246#define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
2247
2248#define get_bucket(x) ((x) >> BUCKET_SPACE)
2249#define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1))
2250#define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
Pavel Emelyanova53eb3f2007-11-23 20:30:01 +08002251
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002252static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253{
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002254 unsigned long offset = get_offset(*pos);
2255 unsigned long bucket = get_bucket(*pos);
2256 struct sock *sk;
2257 unsigned long count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002259 for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) {
2260 if (sock_net(sk) != seq_file_net(seq))
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002261 continue;
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002262 if (++count == offset)
2263 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264 }
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002265
2266 return sk;
2267}
2268
2269static struct sock *unix_next_socket(struct seq_file *seq,
2270 struct sock *sk,
2271 loff_t *pos)
2272{
2273 unsigned long bucket;
2274
2275 while (sk > (struct sock *)SEQ_START_TOKEN) {
2276 sk = sk_next(sk);
2277 if (!sk)
2278 goto next_bucket;
2279 if (sock_net(sk) == seq_file_net(seq))
2280 return sk;
2281 }
2282
2283 do {
2284 sk = unix_from_bucket(seq, pos);
2285 if (sk)
2286 return sk;
2287
2288next_bucket:
2289 bucket = get_bucket(*pos) + 1;
2290 *pos = set_bucket_offset(bucket, 1);
2291 } while (bucket < ARRAY_SIZE(unix_socket_table));
2292
Linus Torvalds1da177e2005-04-16 15:20:36 -07002293 return NULL;
2294}
2295
Linus Torvalds1da177e2005-04-16 15:20:36 -07002296static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08002297 __acquires(unix_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002298{
David S. Millerfbe9cc42005-12-13 23:26:29 -08002299 spin_lock(&unix_table_lock);
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002300
2301 if (!*pos)
2302 return SEQ_START_TOKEN;
2303
2304 if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table))
2305 return NULL;
2306
2307 return unix_next_socket(seq, NULL, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308}
2309
2310static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2311{
2312 ++*pos;
Eric Dumazet7123aaa2012-06-08 05:03:21 +00002313 return unix_next_socket(seq, v, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002314}
2315
2316static void unix_seq_stop(struct seq_file *seq, void *v)
Eric Dumazet9a429c42008-01-01 21:58:02 -08002317 __releases(unix_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318{
David S. Millerfbe9cc42005-12-13 23:26:29 -08002319 spin_unlock(&unix_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002320}
2321
2322static int unix_seq_show(struct seq_file *seq, void *v)
2323{
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09002324
Joe Perchesb9f31242008-04-12 19:04:38 -07002325 if (v == SEQ_START_TOKEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002326 seq_puts(seq, "Num RefCount Protocol Flags Type St "
2327 "Inode Path\n");
2328 else {
2329 struct sock *s = v;
2330 struct unix_sock *u = unix_sk(s);
David S. Miller1c92b4e2007-05-31 13:24:26 -07002331 unix_state_lock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332
Dan Rosenberg71338aa2011-05-23 12:17:35 +00002333 seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002334 s,
2335 atomic_read(&s->sk_refcnt),
2336 0,
2337 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2338 s->sk_type,
2339 s->sk_socket ?
2340 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2341 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2342 sock_i_ino(s));
2343
2344 if (u->addr) {
2345 int i, len;
2346 seq_putc(seq, ' ');
2347
2348 i = 0;
2349 len = u->addr->len - sizeof(short);
2350 if (!UNIX_ABSTRACT(s))
2351 len--;
2352 else {
2353 seq_putc(seq, '@');
2354 i++;
2355 }
2356 for ( ; i < len; i++)
2357 seq_putc(seq, u->addr->name->sun_path[i]);
2358 }
David S. Miller1c92b4e2007-05-31 13:24:26 -07002359 unix_state_unlock(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002360 seq_putc(seq, '\n');
2361 }
2362
2363 return 0;
2364}
2365
Philippe De Muyter56b3d972007-07-10 23:07:31 -07002366static const struct seq_operations unix_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367 .start = unix_seq_start,
2368 .next = unix_seq_next,
2369 .stop = unix_seq_stop,
2370 .show = unix_seq_show,
2371};
2372
Linus Torvalds1da177e2005-04-16 15:20:36 -07002373static int unix_seq_open(struct inode *inode, struct file *file)
2374{
Denis V. Luneve372c412007-11-19 22:31:54 -08002375 return seq_open_net(inode, file, &unix_seq_ops,
Eric Dumazet8b51b062012-06-08 22:10:20 +00002376 sizeof(struct seq_net_private));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002377}
2378
Arjan van de Venda7071d2007-02-12 00:55:36 -08002379static const struct file_operations unix_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002380 .owner = THIS_MODULE,
2381 .open = unix_seq_open,
2382 .read = seq_read,
2383 .llseek = seq_lseek,
Denis V. Luneve372c412007-11-19 22:31:54 -08002384 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002385};
2386
2387#endif
2388
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +00002389static const struct net_proto_family unix_family_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002390 .family = PF_UNIX,
2391 .create = unix_create,
2392 .owner = THIS_MODULE,
2393};
2394
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002395
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00002396static int __net_init unix_net_init(struct net *net)
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002397{
2398 int error = -ENOMEM;
2399
Denis V. Luneva0a53c82007-12-11 04:19:17 -08002400 net->unx.sysctl_max_dgram_qlen = 10;
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002401 if (unix_sysctl_register(net))
2402 goto out;
Pavel Emelyanovd392e492007-12-01 23:44:15 +11002403
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002404#ifdef CONFIG_PROC_FS
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002405 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) {
2406 unix_sysctl_unregister(net);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002407 goto out;
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002408 }
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002409#endif
2410 error = 0;
2411out:
Jianjun Kong48dcc33e2008-11-01 21:37:27 -07002412 return error;
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002413}
2414
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00002415static void __net_exit unix_net_exit(struct net *net)
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002416{
Pavel Emelyanov1597fbc2007-12-01 23:51:01 +11002417 unix_sysctl_unregister(net);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002418 proc_net_remove(net, "unix");
2419}
2420
2421static struct pernet_operations unix_net_ops = {
2422 .init = unix_net_init,
2423 .exit = unix_net_exit,
2424};
2425
Linus Torvalds1da177e2005-04-16 15:20:36 -07002426static int __init af_unix_init(void)
2427{
2428 int rc = -1;
2429 struct sk_buff *dummy_skb;
2430
YOSHIFUJI Hideakief047f52006-09-01 00:29:06 -07002431 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002432
2433 rc = proto_register(&unix_proto, 1);
YOSHIFUJI Hideakiac7bfa62007-02-09 23:25:23 +09002434 if (rc != 0) {
2435 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08002436 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437 goto out;
2438 }
2439
2440 sock_register(&unix_family_ops);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002441 register_pernet_subsys(&unix_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442out:
2443 return rc;
2444}
2445
2446static void __exit af_unix_exit(void)
2447{
2448 sock_unregister(PF_UNIX);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449 proto_unregister(&unix_proto);
Denis V. Lunev097e66c2007-11-19 22:29:30 -08002450 unregister_pernet_subsys(&unix_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002451}
2452
David Woodhouse3d366962008-04-24 00:59:25 -07002453/* Earlier than device_initcall() so that other drivers invoking
2454 request_module() don't end up in a loop when modprobe tries
2455 to use a UNIX socket. But later than subsys_initcall() because
2456 we depend on stuff initialised there */
2457fs_initcall(af_unix_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002458module_exit(af_unix_exit);
2459
2460MODULE_LICENSE("GPL");
2461MODULE_ALIAS_NETPROTO(PF_UNIX);