Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * NET4: Implementation of BSD Unix domain sockets. | |
4 | * | |
113aa838 | 5 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 6 | * |
1da177e4 LT |
7 | * Fixes: |
8 | * Linus Torvalds : Assorted bug cures. | |
9 | * Niibe Yutaka : async I/O support. | |
10 | * Carsten Paeth : PF_UNIX check, address fixes. | |
11 | * Alan Cox : Limit size of allocated blocks. | |
12 | * Alan Cox : Fixed the stupid socketpair bug. | |
13 | * Alan Cox : BSD compatibility fine tuning. | |
14 | * Alan Cox : Fixed a bug in connect when interrupted. | |
15 | * Alan Cox : Sorted out a proper draft version of | |
16 | * file descriptor passing hacked up from | |
17 | * Mike Shaver's work. | |
18 | * Marty Leisner : Fixes to fd passing | |
19 | * Nick Nevin : recvmsg bugfix. | |
20 | * Alan Cox : Started proper garbage collector | |
21 | * Heiko EiBfeldt : Missing verify_area check | |
22 | * Alan Cox : Started POSIXisms | |
23 | * Andreas Schwab : Replace inode by dentry for proper | |
24 | * reference counting | |
25 | * Kirk Petersen : Made this a module | |
26 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. | |
27 | * Lots of bug fixes. | |
28 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces | |
29 | * by above two patches. | |
30 | * Andrea Arcangeli : If possible we block in connect(2) | |
31 | * if the max backlog of the listen socket | |
32 | * is been reached. This won't break | |
33 | * old apps and it will avoid huge amount | |
34 | * of socks hashed (this for unix_gc() | |
35 | * performances reasons). | |
36 | * Security fix that limits the max | |
37 | * number of socks to 2*max_files and | |
38 | * the number of skb queueable in the | |
39 | * dgram receiver. | |
40 | * Artur Skawina : Hash function optimizations | |
41 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) | |
42 | * Malcolm Beattie : Set peercred for socketpair | |
43 | * Michal Ostrowski : Module initialization cleanup. | |
44 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, | |
45 | * the core infrastructure is doing that | |
46 | * for all net proto families now (2.5.69+) | |
47 | * | |
1da177e4 LT |
48 | * Known differences from reference BSD that was tested: |
49 | * | |
50 | * [TO FIX] | |
51 | * ECONNREFUSED is not returned from one end of a connected() socket to the | |
52 | * other the moment one end closes. | |
53 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark | |
54 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). | |
55 | * [NOT TO FIX] | |
56 | * accept() returns a path name even if the connecting socket has closed | |
57 | * in the meantime (BSD loses the path and gives up). | |
58 | * accept() returns 0 length path for an unbound connector. BSD returns 16 | |
59 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) | |
60 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. | |
61 | * BSD af_unix apparently has connect forgetting to block properly. | |
62 | * (need to check this with the POSIX spec in detail) | |
63 | * | |
64 | * Differences from 2.0.0-11-... (ANK) | |
65 | * Bug fixes and improvements. | |
66 | * - client shutdown killed server socket. | |
67 | * - removed all useless cli/sti pairs. | |
68 | * | |
69 | * Semantic changes/extensions. | |
70 | * - generic control message passing. | |
71 | * - SCM_CREDENTIALS control message. | |
72 | * - "Abstract" (not FS based) socket bindings. | |
73 | * Abstract names are sequences of bytes (not zero terminated) | |
74 | * started by 0, so that this name space does not intersect | |
75 | * with BSD names. | |
76 | */ | |
77 | ||
5cc208be | 78 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
79 | ||
1da177e4 | 80 | #include <linux/module.h> |
1da177e4 | 81 | #include <linux/kernel.h> |
1da177e4 | 82 | #include <linux/signal.h> |
3f07c014 | 83 | #include <linux/sched/signal.h> |
1da177e4 LT |
84 | #include <linux/errno.h> |
85 | #include <linux/string.h> | |
86 | #include <linux/stat.h> | |
87 | #include <linux/dcache.h> | |
88 | #include <linux/namei.h> | |
89 | #include <linux/socket.h> | |
90 | #include <linux/un.h> | |
91 | #include <linux/fcntl.h> | |
b6459415 | 92 | #include <linux/filter.h> |
1da177e4 LT |
93 | #include <linux/termios.h> |
94 | #include <linux/sockios.h> | |
95 | #include <linux/net.h> | |
96 | #include <linux/in.h> | |
97 | #include <linux/fs.h> | |
98 | #include <linux/slab.h> | |
7c0f6ba6 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | #include <linux/skbuff.h> |
101 | #include <linux/netdevice.h> | |
457c4cbc | 102 | #include <net/net_namespace.h> |
1da177e4 | 103 | #include <net/sock.h> |
c752f073 | 104 | #include <net/tcp_states.h> |
1da177e4 LT |
105 | #include <net/af_unix.h> |
106 | #include <linux/proc_fs.h> | |
107 | #include <linux/seq_file.h> | |
108 | #include <net/scm.h> | |
109 | #include <linux/init.h> | |
110 | #include <linux/poll.h> | |
1da177e4 LT |
111 | #include <linux/rtnetlink.h> |
112 | #include <linux/mount.h> | |
113 | #include <net/checksum.h> | |
114 | #include <linux/security.h> | |
509f15b9 | 115 | #include <linux/splice.h> |
2b15af6f | 116 | #include <linux/freezer.h> |
ba94f308 | 117 | #include <linux/file.h> |
2c860a43 | 118 | #include <linux/btf_ids.h> |
859051dd | 119 | #include <linux/bpf-cgroup.h> |
1da177e4 | 120 | |
f4e65870 JA |
121 | #include "scm.h" |
122 | ||
518de9b3 | 123 | static atomic_long_t unix_nr_socks; |
51bae889 KI |
124 | static struct hlist_head bsd_socket_buckets[UNIX_HASH_SIZE / 2]; |
125 | static spinlock_t bsd_socket_locks[UNIX_HASH_SIZE / 2]; | |
1da177e4 | 126 | |
f452be49 | 127 | /* SMP locking strategy: |
2f7ca90a KI |
128 | * hash table is protected with spinlock. |
129 | * each socket state is protected by separate spinlock. | |
f452be49 | 130 | */ |
1da177e4 | 131 | |
f452be49 | 132 | static unsigned int unix_unbound_hash(struct sock *sk) |
7123aaa3 | 133 | { |
f452be49 | 134 | unsigned long hash = (unsigned long)sk; |
7123aaa3 ED |
135 | |
136 | hash ^= hash >> 16; | |
137 | hash ^= hash >> 8; | |
f452be49 KI |
138 | hash ^= sk->sk_type; |
139 | ||
cf21b355 | 140 | return hash & UNIX_HASH_MOD; |
f452be49 KI |
141 | } |
142 | ||
143 | static unsigned int unix_bsd_hash(struct inode *i) | |
144 | { | |
f302d180 | 145 | return i->i_ino & UNIX_HASH_MOD; |
f452be49 KI |
146 | } |
147 | ||
148 | static unsigned int unix_abstract_hash(struct sockaddr_un *sunaddr, | |
149 | int addr_len, int type) | |
150 | { | |
151 | __wsum csum = csum_partial(sunaddr, addr_len, 0); | |
152 | unsigned int hash; | |
153 | ||
154 | hash = (__force unsigned int)csum_fold(csum); | |
155 | hash ^= hash >> 8; | |
156 | hash ^= type; | |
157 | ||
cf21b355 | 158 | return UNIX_HASH_MOD + 1 + (hash & UNIX_HASH_MOD); |
7123aaa3 ED |
159 | } |
160 | ||
79b05bea KI |
161 | static void unix_table_double_lock(struct net *net, |
162 | unsigned int hash1, unsigned int hash2) | |
afd20b92 | 163 | { |
cf21b355 KI |
164 | if (hash1 == hash2) { |
165 | spin_lock(&net->unx.table.locks[hash1]); | |
166 | return; | |
167 | } | |
168 | ||
afd20b92 KI |
169 | if (hash1 > hash2) |
170 | swap(hash1, hash2); | |
171 | ||
79b05bea KI |
172 | spin_lock(&net->unx.table.locks[hash1]); |
173 | spin_lock_nested(&net->unx.table.locks[hash2], SINGLE_DEPTH_NESTING); | |
afd20b92 KI |
174 | } |
175 | ||
79b05bea KI |
176 | static void unix_table_double_unlock(struct net *net, |
177 | unsigned int hash1, unsigned int hash2) | |
afd20b92 | 178 | { |
cf21b355 KI |
179 | if (hash1 == hash2) { |
180 | spin_unlock(&net->unx.table.locks[hash1]); | |
181 | return; | |
182 | } | |
183 | ||
79b05bea KI |
184 | spin_unlock(&net->unx.table.locks[hash1]); |
185 | spin_unlock(&net->unx.table.locks[hash2]); | |
afd20b92 KI |
186 | } |
187 | ||
877ce7c1 | 188 | #ifdef CONFIG_SECURITY_NETWORK |
dc49c1f9 | 189 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 | 190 | { |
37a9a8df | 191 | UNIXCB(skb).secid = scm->secid; |
877ce7c1 CZ |
192 | } |
193 | ||
194 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
195 | { | |
37a9a8df SS |
196 | scm->secid = UNIXCB(skb).secid; |
197 | } | |
198 | ||
199 | static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) | |
200 | { | |
201 | return (scm->secid == UNIXCB(skb).secid); | |
877ce7c1 CZ |
202 | } |
203 | #else | |
dc49c1f9 | 204 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
877ce7c1 CZ |
205 | { } |
206 | ||
207 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) | |
208 | { } | |
37a9a8df SS |
209 | |
210 | static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) | |
211 | { | |
212 | return true; | |
213 | } | |
877ce7c1 CZ |
214 | #endif /* CONFIG_SECURITY_NETWORK */ |
215 | ||
1da177e4 LT |
216 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) |
217 | { | |
218 | return unix_peer(osk) == sk; | |
219 | } | |
220 | ||
221 | static inline int unix_may_send(struct sock *sk, struct sock *osk) | |
222 | { | |
6eba6a37 | 223 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
1da177e4 LT |
224 | } |
225 | ||
86b18aaa | 226 | static inline int unix_recvq_full(const struct sock *sk) |
3c73419c RW |
227 | { |
228 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; | |
229 | } | |
230 | ||
86b18aaa QC |
231 | static inline int unix_recvq_full_lockless(const struct sock *sk) |
232 | { | |
233 | return skb_queue_len_lockless(&sk->sk_receive_queue) > | |
234 | READ_ONCE(sk->sk_max_ack_backlog); | |
235 | } | |
236 | ||
fa7ff56f | 237 | struct sock *unix_peer_get(struct sock *s) |
1da177e4 LT |
238 | { |
239 | struct sock *peer; | |
240 | ||
1c92b4e5 | 241 | unix_state_lock(s); |
1da177e4 LT |
242 | peer = unix_peer(s); |
243 | if (peer) | |
244 | sock_hold(peer); | |
1c92b4e5 | 245 | unix_state_unlock(s); |
1da177e4 LT |
246 | return peer; |
247 | } | |
fa7ff56f | 248 | EXPORT_SYMBOL_GPL(unix_peer_get); |
1da177e4 | 249 | |
12f21c49 KI |
250 | static struct unix_address *unix_create_addr(struct sockaddr_un *sunaddr, |
251 | int addr_len) | |
252 | { | |
253 | struct unix_address *addr; | |
254 | ||
255 | addr = kmalloc(sizeof(*addr) + addr_len, GFP_KERNEL); | |
256 | if (!addr) | |
257 | return NULL; | |
258 | ||
259 | refcount_set(&addr->refcnt, 1); | |
260 | addr->len = addr_len; | |
261 | memcpy(addr->name, sunaddr, addr_len); | |
262 | ||
263 | return addr; | |
264 | } | |
265 | ||
1da177e4 LT |
266 | static inline void unix_release_addr(struct unix_address *addr) |
267 | { | |
8c9814b9 | 268 | if (refcount_dec_and_test(&addr->refcnt)) |
1da177e4 LT |
269 | kfree(addr); |
270 | } | |
271 | ||
272 | /* | |
273 | * Check unix socket name: | |
274 | * - should be not zero length. | |
275 | * - if started by not zero, should be NULL terminated (FS object) | |
276 | * - if started by zero, it is abstract name. | |
277 | */ | |
ac7bfa62 | 278 | |
b8a58aa6 KI |
279 | static int unix_validate_addr(struct sockaddr_un *sunaddr, int addr_len) |
280 | { | |
281 | if (addr_len <= offsetof(struct sockaddr_un, sun_path) || | |
282 | addr_len > sizeof(*sunaddr)) | |
283 | return -EINVAL; | |
284 | ||
285 | if (sunaddr->sun_family != AF_UNIX) | |
286 | return -EINVAL; | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
ecb4534b | 291 | static int unix_mkname_bsd(struct sockaddr_un *sunaddr, int addr_len) |
d2d8c9fd | 292 | { |
ecb4534b KI |
293 | struct sockaddr_storage *addr = (struct sockaddr_storage *)sunaddr; |
294 | short offset = offsetof(struct sockaddr_storage, __data); | |
295 | ||
296 | BUILD_BUG_ON(offset != offsetof(struct sockaddr_un, sun_path)); | |
297 | ||
d2d8c9fd KI |
298 | /* This may look like an off by one error but it is a bit more |
299 | * subtle. 108 is the longest valid AF_UNIX path for a binding. | |
300 | * sun_path[108] doesn't as such exist. However in kernel space | |
301 | * we are guaranteed that it is a valid memory location in our | |
302 | * kernel address buffer because syscall functions always pass | |
303 | * a pointer of struct sockaddr_storage which has a bigger buffer | |
ecb4534b KI |
304 | * than 108. Also, we must terminate sun_path for strlen() in |
305 | * getname_kernel(). | |
306 | */ | |
307 | addr->__data[addr_len - offset] = 0; | |
308 | ||
309 | /* Don't pass sunaddr->sun_path to strlen(). Otherwise, 108 will | |
310 | * cause panic if CONFIG_FORTIFY_SOURCE=y. Let __fortify_strlen() | |
311 | * know the actual buffer. | |
d2d8c9fd | 312 | */ |
ecb4534b | 313 | return strlen(addr->__data) + offset + 1; |
d2d8c9fd KI |
314 | } |
315 | ||
1da177e4 LT |
316 | static void __unix_remove_socket(struct sock *sk) |
317 | { | |
318 | sk_del_node_init(sk); | |
319 | } | |
320 | ||
cf2f225e | 321 | static void __unix_insert_socket(struct net *net, struct sock *sk) |
1da177e4 | 322 | { |
dd29c67d | 323 | DEBUG_NET_WARN_ON_ONCE(!sk_unhashed(sk)); |
cf2f225e | 324 | sk_add_node(sk, &net->unx.table.buckets[sk->sk_hash]); |
1da177e4 LT |
325 | } |
326 | ||
cf2f225e KI |
327 | static void __unix_set_addr_hash(struct net *net, struct sock *sk, |
328 | struct unix_address *addr, unsigned int hash) | |
185ab886 AV |
329 | { |
330 | __unix_remove_socket(sk); | |
331 | smp_store_release(&unix_sk(sk)->addr, addr); | |
e6b4b873 KI |
332 | |
333 | sk->sk_hash = hash; | |
cf2f225e | 334 | __unix_insert_socket(net, sk); |
185ab886 AV |
335 | } |
336 | ||
79b05bea | 337 | static void unix_remove_socket(struct net *net, struct sock *sk) |
1da177e4 | 338 | { |
79b05bea | 339 | spin_lock(&net->unx.table.locks[sk->sk_hash]); |
1da177e4 | 340 | __unix_remove_socket(sk); |
79b05bea | 341 | spin_unlock(&net->unx.table.locks[sk->sk_hash]); |
1da177e4 LT |
342 | } |
343 | ||
79b05bea | 344 | static void unix_insert_unbound_socket(struct net *net, struct sock *sk) |
1da177e4 | 345 | { |
79b05bea | 346 | spin_lock(&net->unx.table.locks[sk->sk_hash]); |
cf2f225e | 347 | __unix_insert_socket(net, sk); |
79b05bea | 348 | spin_unlock(&net->unx.table.locks[sk->sk_hash]); |
1da177e4 LT |
349 | } |
350 | ||
51bae889 KI |
351 | static void unix_insert_bsd_socket(struct sock *sk) |
352 | { | |
353 | spin_lock(&bsd_socket_locks[sk->sk_hash]); | |
354 | sk_add_bind_node(sk, &bsd_socket_buckets[sk->sk_hash]); | |
355 | spin_unlock(&bsd_socket_locks[sk->sk_hash]); | |
356 | } | |
357 | ||
358 | static void unix_remove_bsd_socket(struct sock *sk) | |
359 | { | |
360 | if (!hlist_unhashed(&sk->sk_bind_node)) { | |
361 | spin_lock(&bsd_socket_locks[sk->sk_hash]); | |
362 | __sk_del_bind_node(sk); | |
363 | spin_unlock(&bsd_socket_locks[sk->sk_hash]); | |
364 | ||
365 | sk_node_init(&sk->sk_bind_node); | |
366 | } | |
367 | } | |
368 | ||
097e66c5 DL |
369 | static struct sock *__unix_find_socket_byname(struct net *net, |
370 | struct sockaddr_un *sunname, | |
be752283 | 371 | int len, unsigned int hash) |
1da177e4 LT |
372 | { |
373 | struct sock *s; | |
1da177e4 | 374 | |
cf2f225e | 375 | sk_for_each(s, &net->unx.table.buckets[hash]) { |
1da177e4 LT |
376 | struct unix_sock *u = unix_sk(s); |
377 | ||
378 | if (u->addr->len == len && | |
379 | !memcmp(u->addr->name, sunname, len)) | |
262ce0af | 380 | return s; |
1da177e4 | 381 | } |
262ce0af | 382 | return NULL; |
1da177e4 LT |
383 | } |
384 | ||
097e66c5 DL |
385 | static inline struct sock *unix_find_socket_byname(struct net *net, |
386 | struct sockaddr_un *sunname, | |
be752283 | 387 | int len, unsigned int hash) |
1da177e4 LT |
388 | { |
389 | struct sock *s; | |
390 | ||
79b05bea | 391 | spin_lock(&net->unx.table.locks[hash]); |
be752283 | 392 | s = __unix_find_socket_byname(net, sunname, len, hash); |
1da177e4 LT |
393 | if (s) |
394 | sock_hold(s); | |
79b05bea | 395 | spin_unlock(&net->unx.table.locks[hash]); |
1da177e4 LT |
396 | return s; |
397 | } | |
398 | ||
51bae889 | 399 | static struct sock *unix_find_socket_byinode(struct inode *i) |
1da177e4 | 400 | { |
f452be49 | 401 | unsigned int hash = unix_bsd_hash(i); |
1da177e4 | 402 | struct sock *s; |
1da177e4 | 403 | |
51bae889 KI |
404 | spin_lock(&bsd_socket_locks[hash]); |
405 | sk_for_each_bound(s, &bsd_socket_buckets[hash]) { | |
40ffe67d | 406 | struct dentry *dentry = unix_sk(s)->path.dentry; |
1da177e4 | 407 | |
beef5121 | 408 | if (dentry && d_backing_inode(dentry) == i) { |
1da177e4 | 409 | sock_hold(s); |
51bae889 | 410 | spin_unlock(&bsd_socket_locks[hash]); |
afd20b92 | 411 | return s; |
1da177e4 LT |
412 | } |
413 | } | |
51bae889 | 414 | spin_unlock(&bsd_socket_locks[hash]); |
afd20b92 | 415 | return NULL; |
1da177e4 LT |
416 | } |
417 | ||
7d267278 RW |
418 | /* Support code for asymmetrically connected dgram sockets |
419 | * | |
420 | * If a datagram socket is connected to a socket not itself connected | |
421 | * to the first socket (eg, /dev/log), clients may only enqueue more | |
422 | * messages if the present receive queue of the server socket is not | |
423 | * "too large". This means there's a second writeability condition | |
424 | * poll and sendmsg need to test. The dgram recv code will do a wake | |
425 | * up on the peer_wait wait queue of a socket upon reception of a | |
426 | * datagram which needs to be propagated to sleeping would-be writers | |
427 | * since these might not have sent anything so far. This can't be | |
428 | * accomplished via poll_wait because the lifetime of the server | |
429 | * socket might be less than that of its clients if these break their | |
430 | * association with it or if the server socket is closed while clients | |
431 | * are still connected to it and there's no way to inform "a polling | |
432 | * implementation" that it should let go of a certain wait queue | |
433 | * | |
ac6424b9 | 434 | * In order to propagate a wake up, a wait_queue_entry_t of the client |
7d267278 RW |
435 | * socket is enqueued on the peer_wait queue of the server socket |
436 | * whose wake function does a wake_up on the ordinary client socket | |
437 | * wait queue. This connection is established whenever a write (or | |
438 | * poll for write) hit the flow control condition and broken when the | |
439 | * association to the server socket is dissolved or after a wake up | |
440 | * was relayed. | |
441 | */ | |
442 | ||
ac6424b9 | 443 | static int unix_dgram_peer_wake_relay(wait_queue_entry_t *q, unsigned mode, int flags, |
7d267278 RW |
444 | void *key) |
445 | { | |
446 | struct unix_sock *u; | |
447 | wait_queue_head_t *u_sleep; | |
448 | ||
449 | u = container_of(q, struct unix_sock, peer_wake); | |
450 | ||
451 | __remove_wait_queue(&unix_sk(u->peer_wake.private)->peer_wait, | |
452 | q); | |
453 | u->peer_wake.private = NULL; | |
454 | ||
455 | /* relaying can only happen while the wq still exists */ | |
456 | u_sleep = sk_sleep(&u->sk); | |
457 | if (u_sleep) | |
3ad6f93e | 458 | wake_up_interruptible_poll(u_sleep, key_to_poll(key)); |
7d267278 RW |
459 | |
460 | return 0; | |
461 | } | |
462 | ||
463 | static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other) | |
464 | { | |
465 | struct unix_sock *u, *u_other; | |
466 | int rc; | |
467 | ||
468 | u = unix_sk(sk); | |
469 | u_other = unix_sk(other); | |
470 | rc = 0; | |
471 | spin_lock(&u_other->peer_wait.lock); | |
472 | ||
473 | if (!u->peer_wake.private) { | |
474 | u->peer_wake.private = other; | |
475 | __add_wait_queue(&u_other->peer_wait, &u->peer_wake); | |
476 | ||
477 | rc = 1; | |
478 | } | |
479 | ||
480 | spin_unlock(&u_other->peer_wait.lock); | |
481 | return rc; | |
482 | } | |
483 | ||
484 | static void unix_dgram_peer_wake_disconnect(struct sock *sk, | |
485 | struct sock *other) | |
486 | { | |
487 | struct unix_sock *u, *u_other; | |
488 | ||
489 | u = unix_sk(sk); | |
490 | u_other = unix_sk(other); | |
491 | spin_lock(&u_other->peer_wait.lock); | |
492 | ||
493 | if (u->peer_wake.private == other) { | |
494 | __remove_wait_queue(&u_other->peer_wait, &u->peer_wake); | |
495 | u->peer_wake.private = NULL; | |
496 | } | |
497 | ||
498 | spin_unlock(&u_other->peer_wait.lock); | |
499 | } | |
500 | ||
501 | static void unix_dgram_peer_wake_disconnect_wakeup(struct sock *sk, | |
502 | struct sock *other) | |
503 | { | |
504 | unix_dgram_peer_wake_disconnect(sk, other); | |
505 | wake_up_interruptible_poll(sk_sleep(sk), | |
a9a08845 LT |
506 | EPOLLOUT | |
507 | EPOLLWRNORM | | |
508 | EPOLLWRBAND); | |
7d267278 RW |
509 | } |
510 | ||
511 | /* preconditions: | |
512 | * - unix_peer(sk) == other | |
513 | * - association is stable | |
514 | */ | |
515 | static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other) | |
516 | { | |
517 | int connected; | |
518 | ||
519 | connected = unix_dgram_peer_wake_connect(sk, other); | |
520 | ||
51f7e951 JB |
521 | /* If other is SOCK_DEAD, we want to make sure we signal |
522 | * POLLOUT, such that a subsequent write() can get a | |
523 | * -ECONNREFUSED. Otherwise, if we haven't queued any skbs | |
524 | * to other and its full, we will hang waiting for POLLOUT. | |
525 | */ | |
662a8094 | 526 | if (unix_recvq_full_lockless(other) && !sock_flag(other, SOCK_DEAD)) |
7d267278 RW |
527 | return 1; |
528 | ||
529 | if (connected) | |
530 | unix_dgram_peer_wake_disconnect(sk, other); | |
531 | ||
532 | return 0; | |
533 | } | |
534 | ||
1586a587 | 535 | static int unix_writable(const struct sock *sk) |
1da177e4 | 536 | { |
1586a587 | 537 | return sk->sk_state != TCP_LISTEN && |
14afee4b | 538 | (refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; |
1da177e4 LT |
539 | } |
540 | ||
541 | static void unix_write_space(struct sock *sk) | |
542 | { | |
43815482 ED |
543 | struct socket_wq *wq; |
544 | ||
545 | rcu_read_lock(); | |
1da177e4 | 546 | if (unix_writable(sk)) { |
43815482 | 547 | wq = rcu_dereference(sk->sk_wq); |
1ce0bf50 | 548 | if (skwq_has_sleeper(wq)) |
67426b75 | 549 | wake_up_interruptible_sync_poll(&wq->wait, |
a9a08845 | 550 | EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND); |
8d8ad9d7 | 551 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
1da177e4 | 552 | } |
43815482 | 553 | rcu_read_unlock(); |
1da177e4 LT |
554 | } |
555 | ||
556 | /* When dgram socket disconnects (or changes its peer), we clear its receive | |
557 | * queue of packets arrived from previous peer. First, it allows to do | |
558 | * flow control based only on wmem_alloc; second, sk connected to peer | |
559 | * may receive messages only from that peer. */ | |
560 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) | |
561 | { | |
b03efcfb | 562 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
1da177e4 LT |
563 | skb_queue_purge(&sk->sk_receive_queue); |
564 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); | |
565 | ||
566 | /* If one link of bidirectional dgram pipe is disconnected, | |
567 | * we signal error. Messages are lost. Do not make this, | |
568 | * when peer was not connected to us. | |
569 | */ | |
570 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { | |
cc04410a | 571 | WRITE_ONCE(other->sk_err, ECONNRESET); |
e3ae2365 | 572 | sk_error_report(other); |
1da177e4 LT |
573 | } |
574 | } | |
dc56ad70 | 575 | other->sk_state = TCP_CLOSE; |
1da177e4 LT |
576 | } |
577 | ||
578 | static void unix_sock_destructor(struct sock *sk) | |
579 | { | |
580 | struct unix_sock *u = unix_sk(sk); | |
581 | ||
582 | skb_queue_purge(&sk->sk_receive_queue); | |
583 | ||
dd29c67d ED |
584 | DEBUG_NET_WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc)); |
585 | DEBUG_NET_WARN_ON_ONCE(!sk_unhashed(sk)); | |
586 | DEBUG_NET_WARN_ON_ONCE(sk->sk_socket); | |
1da177e4 | 587 | if (!sock_flag(sk, SOCK_DEAD)) { |
5cc208be | 588 | pr_info("Attempt to release alive unix socket: %p\n", sk); |
1da177e4 LT |
589 | return; |
590 | } | |
591 | ||
592 | if (u->addr) | |
593 | unix_release_addr(u->addr); | |
594 | ||
518de9b3 | 595 | atomic_long_dec(&unix_nr_socks); |
a8076d8d | 596 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
1da177e4 | 597 | #ifdef UNIX_REFCNT_DEBUG |
5cc208be | 598 | pr_debug("UNIX %p is destroyed, %ld are still alive.\n", sk, |
518de9b3 | 599 | atomic_long_read(&unix_nr_socks)); |
1da177e4 LT |
600 | #endif |
601 | } | |
602 | ||
ded34e0f | 603 | static void unix_release_sock(struct sock *sk, int embrion) |
1da177e4 LT |
604 | { |
605 | struct unix_sock *u = unix_sk(sk); | |
1da177e4 LT |
606 | struct sock *skpair; |
607 | struct sk_buff *skb; | |
79b05bea | 608 | struct path path; |
1da177e4 LT |
609 | int state; |
610 | ||
79b05bea | 611 | unix_remove_socket(sock_net(sk), sk); |
51bae889 | 612 | unix_remove_bsd_socket(sk); |
1da177e4 LT |
613 | |
614 | /* Clear state */ | |
1c92b4e5 | 615 | unix_state_lock(sk); |
1da177e4 | 616 | sock_orphan(sk); |
e1d09c2c | 617 | WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK); |
40ffe67d AV |
618 | path = u->path; |
619 | u->path.dentry = NULL; | |
620 | u->path.mnt = NULL; | |
1da177e4 LT |
621 | state = sk->sk_state; |
622 | sk->sk_state = TCP_CLOSE; | |
a494bd64 ED |
623 | |
624 | skpair = unix_peer(sk); | |
625 | unix_peer(sk) = NULL; | |
626 | ||
1c92b4e5 | 627 | unix_state_unlock(sk); |
1da177e4 | 628 | |
7a62ed61 KI |
629 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
630 | if (u->oob_skb) { | |
631 | kfree_skb(u->oob_skb); | |
632 | u->oob_skb = NULL; | |
633 | } | |
634 | #endif | |
635 | ||
1da177e4 LT |
636 | wake_up_interruptible_all(&u->peer_wait); |
637 | ||
e27dfcea | 638 | if (skpair != NULL) { |
1da177e4 | 639 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
1c92b4e5 | 640 | unix_state_lock(skpair); |
1da177e4 | 641 | /* No more writes */ |
e1d09c2c | 642 | WRITE_ONCE(skpair->sk_shutdown, SHUTDOWN_MASK); |
1da177e4 | 643 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) |
cc04410a | 644 | WRITE_ONCE(skpair->sk_err, ECONNRESET); |
1c92b4e5 | 645 | unix_state_unlock(skpair); |
1da177e4 | 646 | skpair->sk_state_change(skpair); |
8d8ad9d7 | 647 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
1da177e4 | 648 | } |
7d267278 RW |
649 | |
650 | unix_dgram_peer_wake_disconnect(sk, skpair); | |
1da177e4 | 651 | sock_put(skpair); /* It may now die */ |
1da177e4 LT |
652 | } |
653 | ||
654 | /* Try to flush out this socket. Throw out buffers at least */ | |
655 | ||
656 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e27dfcea | 657 | if (state == TCP_LISTEN) |
1da177e4 LT |
658 | unix_release_sock(skb->sk, 1); |
659 | /* passed fds are erased in the kfree_skb hook */ | |
73ed5d25 | 660 | UNIXCB(skb).consumed = skb->len; |
1da177e4 LT |
661 | kfree_skb(skb); |
662 | } | |
663 | ||
40ffe67d AV |
664 | if (path.dentry) |
665 | path_put(&path); | |
1da177e4 LT |
666 | |
667 | sock_put(sk); | |
668 | ||
669 | /* ---- Socket is dead now and most probably destroyed ---- */ | |
670 | ||
671 | /* | |
e04dae84 | 672 | * Fixme: BSD difference: In BSD all sockets connected to us get |
1da177e4 LT |
673 | * ECONNRESET and we die on the spot. In Linux we behave |
674 | * like files and pipes do and wait for the last | |
675 | * dereference. | |
676 | * | |
677 | * Can't we simply set sock->err? | |
678 | * | |
679 | * What the above comment does talk about? --ANK(980817) | |
680 | */ | |
681 | ||
ade32bd8 | 682 | if (READ_ONCE(unix_tot_inflight)) |
ac7bfa62 | 683 | unix_gc(); /* Garbage collect fds */ |
1da177e4 LT |
684 | } |
685 | ||
109f6e39 EB |
686 | static void init_peercred(struct sock *sk) |
687 | { | |
35306eb2 ED |
688 | const struct cred *old_cred; |
689 | struct pid *old_pid; | |
690 | ||
691 | spin_lock(&sk->sk_peer_lock); | |
692 | old_pid = sk->sk_peer_pid; | |
693 | old_cred = sk->sk_peer_cred; | |
109f6e39 EB |
694 | sk->sk_peer_pid = get_pid(task_tgid(current)); |
695 | sk->sk_peer_cred = get_current_cred(); | |
35306eb2 ED |
696 | spin_unlock(&sk->sk_peer_lock); |
697 | ||
698 | put_pid(old_pid); | |
699 | put_cred(old_cred); | |
109f6e39 EB |
700 | } |
701 | ||
702 | static void copy_peercred(struct sock *sk, struct sock *peersk) | |
703 | { | |
35306eb2 ED |
704 | const struct cred *old_cred; |
705 | struct pid *old_pid; | |
706 | ||
707 | if (sk < peersk) { | |
708 | spin_lock(&sk->sk_peer_lock); | |
709 | spin_lock_nested(&peersk->sk_peer_lock, SINGLE_DEPTH_NESTING); | |
710 | } else { | |
711 | spin_lock(&peersk->sk_peer_lock); | |
712 | spin_lock_nested(&sk->sk_peer_lock, SINGLE_DEPTH_NESTING); | |
713 | } | |
714 | old_pid = sk->sk_peer_pid; | |
715 | old_cred = sk->sk_peer_cred; | |
109f6e39 EB |
716 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); |
717 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); | |
35306eb2 ED |
718 | |
719 | spin_unlock(&sk->sk_peer_lock); | |
720 | spin_unlock(&peersk->sk_peer_lock); | |
721 | ||
722 | put_pid(old_pid); | |
723 | put_cred(old_cred); | |
109f6e39 EB |
724 | } |
725 | ||
1da177e4 LT |
726 | static int unix_listen(struct socket *sock, int backlog) |
727 | { | |
728 | int err; | |
729 | struct sock *sk = sock->sk; | |
730 | struct unix_sock *u = unix_sk(sk); | |
731 | ||
732 | err = -EOPNOTSUPP; | |
6eba6a37 ED |
733 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
734 | goto out; /* Only stream/seqpacket sockets accept */ | |
1da177e4 LT |
735 | err = -EINVAL; |
736 | if (!u->addr) | |
6eba6a37 | 737 | goto out; /* No listens on an unbound socket */ |
1c92b4e5 | 738 | unix_state_lock(sk); |
1da177e4 LT |
739 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
740 | goto out_unlock; | |
741 | if (backlog > sk->sk_max_ack_backlog) | |
742 | wake_up_interruptible_all(&u->peer_wait); | |
743 | sk->sk_max_ack_backlog = backlog; | |
744 | sk->sk_state = TCP_LISTEN; | |
745 | /* set credentials so connect can copy them */ | |
109f6e39 | 746 | init_peercred(sk); |
1da177e4 LT |
747 | err = 0; |
748 | ||
749 | out_unlock: | |
1c92b4e5 | 750 | unix_state_unlock(sk); |
1da177e4 LT |
751 | out: |
752 | return err; | |
753 | } | |
754 | ||
755 | static int unix_release(struct socket *); | |
756 | static int unix_bind(struct socket *, struct sockaddr *, int); | |
757 | static int unix_stream_connect(struct socket *, struct sockaddr *, | |
758 | int addr_len, int flags); | |
759 | static int unix_socketpair(struct socket *, struct socket *); | |
cdfbabfb | 760 | static int unix_accept(struct socket *, struct socket *, int, bool); |
9b2c45d4 | 761 | static int unix_getname(struct socket *, struct sockaddr *, int); |
a11e1d43 LT |
762 | static __poll_t unix_poll(struct file *, struct socket *, poll_table *); |
763 | static __poll_t unix_dgram_poll(struct file *, struct socket *, | |
764 | poll_table *); | |
1da177e4 | 765 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
5f6beb9e AB |
766 | #ifdef CONFIG_COMPAT |
767 | static int unix_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg); | |
768 | #endif | |
1da177e4 | 769 | static int unix_shutdown(struct socket *, int); |
1b784140 YX |
770 | static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t); |
771 | static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
2b514574 HFS |
772 | static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos, |
773 | struct pipe_inode_info *, size_t size, | |
774 | unsigned int flags); | |
1b784140 YX |
775 | static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t); |
776 | static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int); | |
965b57b4 CW |
777 | static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor); |
778 | static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor); | |
1da177e4 LT |
779 | static int unix_dgram_connect(struct socket *, struct sockaddr *, |
780 | int, int); | |
1b784140 YX |
781 | static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t); |
782 | static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t, | |
783 | int); | |
1da177e4 | 784 | |
5c05a164 | 785 | #ifdef CONFIG_PROC_FS |
de437089 KT |
786 | static int unix_count_nr_fds(struct sock *sk) |
787 | { | |
788 | struct sk_buff *skb; | |
789 | struct unix_sock *u; | |
790 | int nr_fds = 0; | |
791 | ||
792 | spin_lock(&sk->sk_receive_queue.lock); | |
793 | skb = skb_peek(&sk->sk_receive_queue); | |
794 | while (skb) { | |
795 | u = unix_sk(skb->sk); | |
796 | nr_fds += atomic_read(&u->scm_stat.nr_fds); | |
797 | skb = skb_peek_next(skb, &sk->sk_receive_queue); | |
798 | } | |
799 | spin_unlock(&sk->sk_receive_queue.lock); | |
800 | ||
801 | return nr_fds; | |
802 | } | |
803 | ||
3c32da19 KT |
804 | static void unix_show_fdinfo(struct seq_file *m, struct socket *sock) |
805 | { | |
806 | struct sock *sk = sock->sk; | |
b27401a3 | 807 | unsigned char s_state; |
3c32da19 | 808 | struct unix_sock *u; |
b27401a3 | 809 | int nr_fds = 0; |
3c32da19 KT |
810 | |
811 | if (sk) { | |
b27401a3 | 812 | s_state = READ_ONCE(sk->sk_state); |
de437089 | 813 | u = unix_sk(sk); |
de437089 | 814 | |
b27401a3 KT |
815 | /* SOCK_STREAM and SOCK_SEQPACKET sockets never change their |
816 | * sk_state after switching to TCP_ESTABLISHED or TCP_LISTEN. | |
817 | * SOCK_DGRAM is ordinary. So, no lock is needed. | |
818 | */ | |
819 | if (sock->type == SOCK_DGRAM || s_state == TCP_ESTABLISHED) | |
de437089 | 820 | nr_fds = atomic_read(&u->scm_stat.nr_fds); |
b27401a3 | 821 | else if (s_state == TCP_LISTEN) |
de437089 | 822 | nr_fds = unix_count_nr_fds(sk); |
b27401a3 | 823 | |
de437089 | 824 | seq_printf(m, "scm_fds: %u\n", nr_fds); |
3c32da19 KT |
825 | } |
826 | } | |
3a12500e TK |
827 | #else |
828 | #define unix_show_fdinfo NULL | |
829 | #endif | |
f55bb7f9 | 830 | |
90ddc4f0 | 831 | static const struct proto_ops unix_stream_ops = { |
1da177e4 LT |
832 | .family = PF_UNIX, |
833 | .owner = THIS_MODULE, | |
834 | .release = unix_release, | |
835 | .bind = unix_bind, | |
836 | .connect = unix_stream_connect, | |
837 | .socketpair = unix_socketpair, | |
838 | .accept = unix_accept, | |
839 | .getname = unix_getname, | |
a11e1d43 | 840 | .poll = unix_poll, |
1da177e4 | 841 | .ioctl = unix_ioctl, |
5f6beb9e AB |
842 | #ifdef CONFIG_COMPAT |
843 | .compat_ioctl = unix_compat_ioctl, | |
844 | #endif | |
1da177e4 LT |
845 | .listen = unix_listen, |
846 | .shutdown = unix_shutdown, | |
1da177e4 LT |
847 | .sendmsg = unix_stream_sendmsg, |
848 | .recvmsg = unix_stream_recvmsg, | |
965b57b4 | 849 | .read_skb = unix_stream_read_skb, |
1da177e4 | 850 | .mmap = sock_no_mmap, |
2b514574 | 851 | .splice_read = unix_stream_splice_read, |
56667da7 | 852 | .set_peek_off = sk_set_peek_off, |
3c32da19 | 853 | .show_fdinfo = unix_show_fdinfo, |
1da177e4 LT |
854 | }; |
855 | ||
90ddc4f0 | 856 | static const struct proto_ops unix_dgram_ops = { |
1da177e4 LT |
857 | .family = PF_UNIX, |
858 | .owner = THIS_MODULE, | |
859 | .release = unix_release, | |
860 | .bind = unix_bind, | |
861 | .connect = unix_dgram_connect, | |
862 | .socketpair = unix_socketpair, | |
863 | .accept = sock_no_accept, | |
864 | .getname = unix_getname, | |
a11e1d43 | 865 | .poll = unix_dgram_poll, |
1da177e4 | 866 | .ioctl = unix_ioctl, |
5f6beb9e AB |
867 | #ifdef CONFIG_COMPAT |
868 | .compat_ioctl = unix_compat_ioctl, | |
869 | #endif | |
1da177e4 LT |
870 | .listen = sock_no_listen, |
871 | .shutdown = unix_shutdown, | |
1da177e4 | 872 | .sendmsg = unix_dgram_sendmsg, |
965b57b4 | 873 | .read_skb = unix_read_skb, |
1da177e4 LT |
874 | .recvmsg = unix_dgram_recvmsg, |
875 | .mmap = sock_no_mmap, | |
56667da7 | 876 | .set_peek_off = sk_set_peek_off, |
3c32da19 | 877 | .show_fdinfo = unix_show_fdinfo, |
1da177e4 LT |
878 | }; |
879 | ||
90ddc4f0 | 880 | static const struct proto_ops unix_seqpacket_ops = { |
1da177e4 LT |
881 | .family = PF_UNIX, |
882 | .owner = THIS_MODULE, | |
883 | .release = unix_release, | |
884 | .bind = unix_bind, | |
885 | .connect = unix_stream_connect, | |
886 | .socketpair = unix_socketpair, | |
887 | .accept = unix_accept, | |
888 | .getname = unix_getname, | |
a11e1d43 | 889 | .poll = unix_dgram_poll, |
1da177e4 | 890 | .ioctl = unix_ioctl, |
5f6beb9e AB |
891 | #ifdef CONFIG_COMPAT |
892 | .compat_ioctl = unix_compat_ioctl, | |
893 | #endif | |
1da177e4 LT |
894 | .listen = unix_listen, |
895 | .shutdown = unix_shutdown, | |
1da177e4 | 896 | .sendmsg = unix_seqpacket_sendmsg, |
a05d2ad1 | 897 | .recvmsg = unix_seqpacket_recvmsg, |
1da177e4 | 898 | .mmap = sock_no_mmap, |
56667da7 | 899 | .set_peek_off = sk_set_peek_off, |
3c32da19 | 900 | .show_fdinfo = unix_show_fdinfo, |
1da177e4 LT |
901 | }; |
902 | ||
c7272e15 CW |
903 | static void unix_close(struct sock *sk, long timeout) |
904 | { | |
905 | /* Nothing to do here, unix socket does not need a ->close(). | |
906 | * This is merely for sockmap. | |
907 | */ | |
908 | } | |
909 | ||
94531cfc JW |
910 | static void unix_unhash(struct sock *sk) |
911 | { | |
912 | /* Nothing to do here, unix socket does not need a ->unhash(). | |
913 | * This is merely for sockmap. | |
914 | */ | |
915 | } | |
916 | ||
7b26952a AM |
917 | static bool unix_bpf_bypass_getsockopt(int level, int optname) |
918 | { | |
919 | if (level == SOL_SOCKET) { | |
920 | switch (optname) { | |
921 | case SO_PEERPIDFD: | |
922 | return true; | |
923 | default: | |
924 | return false; | |
925 | } | |
926 | } | |
927 | ||
928 | return false; | |
929 | } | |
930 | ||
94531cfc | 931 | struct proto unix_dgram_proto = { |
0edf0824 | 932 | .name = "UNIX", |
248969ae | 933 | .owner = THIS_MODULE, |
248969ae | 934 | .obj_size = sizeof(struct unix_sock), |
c7272e15 | 935 | .close = unix_close, |
7b26952a | 936 | .bpf_bypass_getsockopt = unix_bpf_bypass_getsockopt, |
c6382918 | 937 | #ifdef CONFIG_BPF_SYSCALL |
94531cfc | 938 | .psock_update_sk_prot = unix_dgram_bpf_update_proto, |
c6382918 | 939 | #endif |
1da177e4 LT |
940 | }; |
941 | ||
94531cfc JW |
942 | struct proto unix_stream_proto = { |
943 | .name = "UNIX-STREAM", | |
248969ae | 944 | .owner = THIS_MODULE, |
248969ae | 945 | .obj_size = sizeof(struct unix_sock), |
c7272e15 | 946 | .close = unix_close, |
94531cfc | 947 | .unhash = unix_unhash, |
7b26952a | 948 | .bpf_bypass_getsockopt = unix_bpf_bypass_getsockopt, |
c6382918 | 949 | #ifdef CONFIG_BPF_SYSCALL |
94531cfc | 950 | .psock_update_sk_prot = unix_stream_bpf_update_proto, |
c6382918 | 951 | #endif |
1da177e4 LT |
952 | }; |
953 | ||
94531cfc | 954 | static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, int type) |
1da177e4 | 955 | { |
1da177e4 | 956 | struct unix_sock *u; |
f4bd73b5 KI |
957 | struct sock *sk; |
958 | int err; | |
1da177e4 | 959 | |
518de9b3 | 960 | atomic_long_inc(&unix_nr_socks); |
f4bd73b5 KI |
961 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) { |
962 | err = -ENFILE; | |
963 | goto err; | |
964 | } | |
1da177e4 | 965 | |
94531cfc JW |
966 | if (type == SOCK_STREAM) |
967 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_stream_proto, kern); | |
968 | else /*dgram and seqpacket */ | |
969 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_dgram_proto, kern); | |
970 | ||
f4bd73b5 KI |
971 | if (!sk) { |
972 | err = -ENOMEM; | |
973 | goto err; | |
974 | } | |
1da177e4 | 975 | |
6eba6a37 | 976 | sock_init_data(sock, sk); |
1da177e4 | 977 | |
e6b4b873 | 978 | sk->sk_hash = unix_unbound_hash(sk); |
3aa9799e | 979 | sk->sk_allocation = GFP_KERNEL_ACCOUNT; |
1da177e4 | 980 | sk->sk_write_space = unix_write_space; |
a0a53c8b | 981 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
1da177e4 LT |
982 | sk->sk_destruct = unix_sock_destructor; |
983 | u = unix_sk(sk); | |
40ffe67d AV |
984 | u->path.dentry = NULL; |
985 | u->path.mnt = NULL; | |
fd19f329 | 986 | spin_lock_init(&u->lock); |
516e0cc5 | 987 | atomic_long_set(&u->inflight, 0); |
1fd05ba5 | 988 | INIT_LIST_HEAD(&u->link); |
6e1ce3c3 LT |
989 | mutex_init(&u->iolock); /* single task reading lock */ |
990 | mutex_init(&u->bindlock); /* single task binding lock */ | |
1da177e4 | 991 | init_waitqueue_head(&u->peer_wait); |
7d267278 | 992 | init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay); |
3c32da19 | 993 | memset(&u->scm_stat, 0, sizeof(struct scm_stat)); |
79b05bea | 994 | unix_insert_unbound_socket(net, sk); |
f4bd73b5 | 995 | |
340c3d33 | 996 | sock_prot_inuse_add(net, sk->sk_prot, 1); |
f4bd73b5 | 997 | |
1da177e4 | 998 | return sk; |
f4bd73b5 KI |
999 | |
1000 | err: | |
1001 | atomic_long_dec(&unix_nr_socks); | |
1002 | return ERR_PTR(err); | |
1da177e4 LT |
1003 | } |
1004 | ||
3f378b68 EP |
1005 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
1006 | int kern) | |
1da177e4 | 1007 | { |
f4bd73b5 KI |
1008 | struct sock *sk; |
1009 | ||
1da177e4 LT |
1010 | if (protocol && protocol != PF_UNIX) |
1011 | return -EPROTONOSUPPORT; | |
1012 | ||
1013 | sock->state = SS_UNCONNECTED; | |
1014 | ||
1015 | switch (sock->type) { | |
1016 | case SOCK_STREAM: | |
1017 | sock->ops = &unix_stream_ops; | |
1018 | break; | |
1019 | /* | |
1020 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though | |
1021 | * nothing uses it. | |
1022 | */ | |
1023 | case SOCK_RAW: | |
e27dfcea | 1024 | sock->type = SOCK_DGRAM; |
df561f66 | 1025 | fallthrough; |
1da177e4 LT |
1026 | case SOCK_DGRAM: |
1027 | sock->ops = &unix_dgram_ops; | |
1028 | break; | |
1029 | case SOCK_SEQPACKET: | |
1030 | sock->ops = &unix_seqpacket_ops; | |
1031 | break; | |
1032 | default: | |
1033 | return -ESOCKTNOSUPPORT; | |
1034 | } | |
1035 | ||
f4bd73b5 KI |
1036 | sk = unix_create1(net, sock, kern, sock->type); |
1037 | if (IS_ERR(sk)) | |
1038 | return PTR_ERR(sk); | |
1039 | ||
1040 | return 0; | |
1da177e4 LT |
1041 | } |
1042 | ||
1043 | static int unix_release(struct socket *sock) | |
1044 | { | |
1045 | struct sock *sk = sock->sk; | |
1046 | ||
1047 | if (!sk) | |
1048 | return 0; | |
1049 | ||
c7272e15 | 1050 | sk->sk_prot->close(sk, 0); |
ded34e0f | 1051 | unix_release_sock(sk, 0); |
1da177e4 LT |
1052 | sock->sk = NULL; |
1053 | ||
ded34e0f | 1054 | return 0; |
1da177e4 LT |
1055 | } |
1056 | ||
51bae889 KI |
1057 | static struct sock *unix_find_bsd(struct sockaddr_un *sunaddr, int addr_len, |
1058 | int type) | |
fa39ef0e KI |
1059 | { |
1060 | struct inode *inode; | |
1061 | struct path path; | |
1062 | struct sock *sk; | |
1063 | int err; | |
1064 | ||
d2d8c9fd | 1065 | unix_mkname_bsd(sunaddr, addr_len); |
fa39ef0e KI |
1066 | err = kern_path(sunaddr->sun_path, LOOKUP_FOLLOW, &path); |
1067 | if (err) | |
1068 | goto fail; | |
1069 | ||
1070 | err = path_permission(&path, MAY_WRITE); | |
1071 | if (err) | |
1072 | goto path_put; | |
1073 | ||
1074 | err = -ECONNREFUSED; | |
1075 | inode = d_backing_inode(path.dentry); | |
1076 | if (!S_ISSOCK(inode->i_mode)) | |
1077 | goto path_put; | |
1078 | ||
51bae889 | 1079 | sk = unix_find_socket_byinode(inode); |
fa39ef0e KI |
1080 | if (!sk) |
1081 | goto path_put; | |
1082 | ||
1083 | err = -EPROTOTYPE; | |
1084 | if (sk->sk_type == type) | |
1085 | touch_atime(&path); | |
1086 | else | |
1087 | goto sock_put; | |
1088 | ||
1089 | path_put(&path); | |
1090 | ||
1091 | return sk; | |
1092 | ||
1093 | sock_put: | |
1094 | sock_put(sk); | |
1095 | path_put: | |
1096 | path_put(&path); | |
1097 | fail: | |
aed26f55 | 1098 | return ERR_PTR(err); |
fa39ef0e KI |
1099 | } |
1100 | ||
1101 | static struct sock *unix_find_abstract(struct net *net, | |
1102 | struct sockaddr_un *sunaddr, | |
d2d8c9fd | 1103 | int addr_len, int type) |
fa39ef0e | 1104 | { |
f452be49 | 1105 | unsigned int hash = unix_abstract_hash(sunaddr, addr_len, type); |
fa39ef0e KI |
1106 | struct dentry *dentry; |
1107 | struct sock *sk; | |
1108 | ||
f452be49 | 1109 | sk = unix_find_socket_byname(net, sunaddr, addr_len, hash); |
aed26f55 KI |
1110 | if (!sk) |
1111 | return ERR_PTR(-ECONNREFUSED); | |
fa39ef0e KI |
1112 | |
1113 | dentry = unix_sk(sk)->path.dentry; | |
1114 | if (dentry) | |
1115 | touch_atime(&unix_sk(sk)->path); | |
1116 | ||
1117 | return sk; | |
1118 | } | |
1119 | ||
1120 | static struct sock *unix_find_other(struct net *net, | |
1121 | struct sockaddr_un *sunaddr, | |
d2d8c9fd | 1122 | int addr_len, int type) |
fa39ef0e KI |
1123 | { |
1124 | struct sock *sk; | |
1125 | ||
1126 | if (sunaddr->sun_path[0]) | |
51bae889 | 1127 | sk = unix_find_bsd(sunaddr, addr_len, type); |
fa39ef0e | 1128 | else |
d2d8c9fd | 1129 | sk = unix_find_abstract(net, sunaddr, addr_len, type); |
fa39ef0e KI |
1130 | |
1131 | return sk; | |
1132 | } | |
1133 | ||
f7ed31f4 | 1134 | static int unix_autobind(struct sock *sk) |
1da177e4 | 1135 | { |
afd20b92 | 1136 | unsigned int new_hash, old_hash = sk->sk_hash; |
1da177e4 | 1137 | struct unix_sock *u = unix_sk(sk); |
79b05bea | 1138 | struct net *net = sock_net(sk); |
6eba6a37 | 1139 | struct unix_address *addr; |
9acbc584 | 1140 | u32 lastnum, ordernum; |
f7ed31f4 | 1141 | int err; |
1da177e4 | 1142 | |
6e1ce3c3 | 1143 | err = mutex_lock_interruptible(&u->bindlock); |
37ab4fa7 SL |
1144 | if (err) |
1145 | return err; | |
1da177e4 | 1146 | |
1da177e4 LT |
1147 | if (u->addr) |
1148 | goto out; | |
1149 | ||
1150 | err = -ENOMEM; | |
755662ce KI |
1151 | addr = kzalloc(sizeof(*addr) + |
1152 | offsetof(struct sockaddr_un, sun_path) + 16, GFP_KERNEL); | |
1da177e4 LT |
1153 | if (!addr) |
1154 | goto out; | |
1155 | ||
9acbc584 | 1156 | addr->len = offsetof(struct sockaddr_un, sun_path) + 6; |
1da177e4 | 1157 | addr->name->sun_family = AF_UNIX; |
8c9814b9 | 1158 | refcount_set(&addr->refcnt, 1); |
1da177e4 | 1159 | |
a251c17a | 1160 | ordernum = get_random_u32(); |
9acbc584 | 1161 | lastnum = ordernum & 0xFFFFF; |
1da177e4 | 1162 | retry: |
9acbc584 KI |
1163 | ordernum = (ordernum + 1) & 0xFFFFF; |
1164 | sprintf(addr->name->sun_path + 1, "%05x", ordernum); | |
1da177e4 | 1165 | |
e6b4b873 | 1166 | new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); |
79b05bea | 1167 | unix_table_double_lock(net, old_hash, new_hash); |
1da177e4 | 1168 | |
79b05bea KI |
1169 | if (__unix_find_socket_byname(net, addr->name, addr->len, new_hash)) { |
1170 | unix_table_double_unlock(net, old_hash, new_hash); | |
afd20b92 | 1171 | |
9acbc584 | 1172 | /* __unix_find_socket_byname() may take long time if many names |
8df73ff9 TH |
1173 | * are already in use. |
1174 | */ | |
1175 | cond_resched(); | |
9acbc584 KI |
1176 | |
1177 | if (ordernum == lastnum) { | |
1178 | /* Give up if all names seems to be in use. */ | |
8df73ff9 | 1179 | err = -ENOSPC; |
9acbc584 | 1180 | unix_release_addr(addr); |
8df73ff9 TH |
1181 | goto out; |
1182 | } | |
9acbc584 | 1183 | |
1da177e4 LT |
1184 | goto retry; |
1185 | } | |
1da177e4 | 1186 | |
cf2f225e | 1187 | __unix_set_addr_hash(net, sk, addr, new_hash); |
79b05bea | 1188 | unix_table_double_unlock(net, old_hash, new_hash); |
1da177e4 LT |
1189 | err = 0; |
1190 | ||
6e1ce3c3 | 1191 | out: mutex_unlock(&u->bindlock); |
1da177e4 LT |
1192 | return err; |
1193 | } | |
1194 | ||
12f21c49 KI |
1195 | static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr, |
1196 | int addr_len) | |
faf02010 | 1197 | { |
71e6be6f AV |
1198 | umode_t mode = S_IFSOCK | |
1199 | (SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask()); | |
afd20b92 | 1200 | unsigned int new_hash, old_hash = sk->sk_hash; |
12f21c49 | 1201 | struct unix_sock *u = unix_sk(sk); |
79b05bea | 1202 | struct net *net = sock_net(sk); |
abf08576 | 1203 | struct mnt_idmap *idmap; |
12f21c49 | 1204 | struct unix_address *addr; |
38f7bd94 | 1205 | struct dentry *dentry; |
12f21c49 | 1206 | struct path parent; |
71e6be6f AV |
1207 | int err; |
1208 | ||
ecb4534b | 1209 | addr_len = unix_mkname_bsd(sunaddr, addr_len); |
12f21c49 KI |
1210 | addr = unix_create_addr(sunaddr, addr_len); |
1211 | if (!addr) | |
1212 | return -ENOMEM; | |
1213 | ||
38f7bd94 LT |
1214 | /* |
1215 | * Get the parent directory, calculate the hash for last | |
1216 | * component. | |
1217 | */ | |
71e6be6f | 1218 | dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0); |
12f21c49 KI |
1219 | if (IS_ERR(dentry)) { |
1220 | err = PTR_ERR(dentry); | |
1221 | goto out; | |
1222 | } | |
faf02010 | 1223 | |
38f7bd94 LT |
1224 | /* |
1225 | * All right, let's create it. | |
1226 | */ | |
abf08576 | 1227 | idmap = mnt_idmap(parent.mnt); |
71e6be6f | 1228 | err = security_path_mknod(&parent, dentry, mode, 0); |
56c1731b | 1229 | if (!err) |
abf08576 | 1230 | err = vfs_mknod(idmap, d_inode(parent.dentry), dentry, mode, 0); |
c0c3b8d3 | 1231 | if (err) |
12f21c49 | 1232 | goto out_path; |
fa42d910 | 1233 | err = mutex_lock_interruptible(&u->bindlock); |
c0c3b8d3 AV |
1234 | if (err) |
1235 | goto out_unlink; | |
1236 | if (u->addr) | |
1237 | goto out_unlock; | |
fa42d910 | 1238 | |
e6b4b873 | 1239 | new_hash = unix_bsd_hash(d_backing_inode(dentry)); |
79b05bea | 1240 | unix_table_double_lock(net, old_hash, new_hash); |
56c1731b AV |
1241 | u->path.mnt = mntget(parent.mnt); |
1242 | u->path.dentry = dget(dentry); | |
cf2f225e | 1243 | __unix_set_addr_hash(net, sk, addr, new_hash); |
79b05bea | 1244 | unix_table_double_unlock(net, old_hash, new_hash); |
51bae889 | 1245 | unix_insert_bsd_socket(sk); |
fa42d910 | 1246 | mutex_unlock(&u->bindlock); |
56c1731b | 1247 | done_path_create(&parent, dentry); |
fa42d910 | 1248 | return 0; |
c0c3b8d3 AV |
1249 | |
1250 | out_unlock: | |
1251 | mutex_unlock(&u->bindlock); | |
1252 | err = -EINVAL; | |
1253 | out_unlink: | |
1254 | /* failed after successful mknod? unlink what we'd created... */ | |
abf08576 | 1255 | vfs_unlink(idmap, d_inode(parent.dentry), dentry, NULL); |
12f21c49 | 1256 | out_path: |
c0c3b8d3 | 1257 | done_path_create(&parent, dentry); |
12f21c49 KI |
1258 | out: |
1259 | unix_release_addr(addr); | |
1260 | return err == -EEXIST ? -EADDRINUSE : err; | |
fa42d910 AV |
1261 | } |
1262 | ||
12f21c49 KI |
1263 | static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr, |
1264 | int addr_len) | |
fa42d910 | 1265 | { |
afd20b92 | 1266 | unsigned int new_hash, old_hash = sk->sk_hash; |
fa42d910 | 1267 | struct unix_sock *u = unix_sk(sk); |
79b05bea | 1268 | struct net *net = sock_net(sk); |
12f21c49 | 1269 | struct unix_address *addr; |
fa42d910 AV |
1270 | int err; |
1271 | ||
12f21c49 KI |
1272 | addr = unix_create_addr(sunaddr, addr_len); |
1273 | if (!addr) | |
1274 | return -ENOMEM; | |
1275 | ||
fa42d910 AV |
1276 | err = mutex_lock_interruptible(&u->bindlock); |
1277 | if (err) | |
12f21c49 | 1278 | goto out; |
fa42d910 AV |
1279 | |
1280 | if (u->addr) { | |
12f21c49 KI |
1281 | err = -EINVAL; |
1282 | goto out_mutex; | |
fa42d910 AV |
1283 | } |
1284 | ||
e6b4b873 | 1285 | new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); |
79b05bea | 1286 | unix_table_double_lock(net, old_hash, new_hash); |
12f21c49 | 1287 | |
79b05bea | 1288 | if (__unix_find_socket_byname(net, addr->name, addr->len, new_hash)) |
12f21c49 KI |
1289 | goto out_spin; |
1290 | ||
cf2f225e | 1291 | __unix_set_addr_hash(net, sk, addr, new_hash); |
79b05bea | 1292 | unix_table_double_unlock(net, old_hash, new_hash); |
fa42d910 AV |
1293 | mutex_unlock(&u->bindlock); |
1294 | return 0; | |
12f21c49 KI |
1295 | |
1296 | out_spin: | |
79b05bea | 1297 | unix_table_double_unlock(net, old_hash, new_hash); |
12f21c49 KI |
1298 | err = -EADDRINUSE; |
1299 | out_mutex: | |
1300 | mutex_unlock(&u->bindlock); | |
1301 | out: | |
1302 | unix_release_addr(addr); | |
1303 | return err; | |
fa42d910 AV |
1304 | } |
1305 | ||
1da177e4 LT |
1306 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
1307 | { | |
e27dfcea | 1308 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
5c32a3ed | 1309 | struct sock *sk = sock->sk; |
5c32a3ed | 1310 | int err; |
1da177e4 | 1311 | |
b8a58aa6 KI |
1312 | if (addr_len == offsetof(struct sockaddr_un, sun_path) && |
1313 | sunaddr->sun_family == AF_UNIX) | |
f7ed31f4 | 1314 | return unix_autobind(sk); |
1da177e4 | 1315 | |
b8a58aa6 KI |
1316 | err = unix_validate_addr(sunaddr, addr_len); |
1317 | if (err) | |
1318 | return err; | |
1319 | ||
12f21c49 KI |
1320 | if (sunaddr->sun_path[0]) |
1321 | err = unix_bind_bsd(sk, sunaddr, addr_len); | |
fa42d910 | 1322 | else |
12f21c49 KI |
1323 | err = unix_bind_abstract(sk, sunaddr, addr_len); |
1324 | ||
1325 | return err; | |
1da177e4 LT |
1326 | } |
1327 | ||
278a3de5 DM |
1328 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
1329 | { | |
1330 | if (unlikely(sk1 == sk2) || !sk2) { | |
1331 | unix_state_lock(sk1); | |
1332 | return; | |
1333 | } | |
4d322dce ED |
1334 | if (sk1 > sk2) |
1335 | swap(sk1, sk2); | |
1336 | ||
1337 | unix_state_lock(sk1); | |
1338 | unix_state_lock_nested(sk2, U_LOCK_SECOND); | |
278a3de5 DM |
1339 | } |
1340 | ||
1341 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) | |
1342 | { | |
1343 | if (unlikely(sk1 == sk2) || !sk2) { | |
1344 | unix_state_unlock(sk1); | |
1345 | return; | |
1346 | } | |
1347 | unix_state_unlock(sk1); | |
1348 | unix_state_unlock(sk2); | |
1349 | } | |
1350 | ||
1da177e4 LT |
1351 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
1352 | int alen, int flags) | |
1353 | { | |
e27dfcea | 1354 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
340c3d33 | 1355 | struct sock *sk = sock->sk; |
1da177e4 | 1356 | struct sock *other; |
1da177e4 LT |
1357 | int err; |
1358 | ||
defbcf2d MJ |
1359 | err = -EINVAL; |
1360 | if (alen < offsetofend(struct sockaddr, sa_family)) | |
1361 | goto out; | |
1362 | ||
1da177e4 | 1363 | if (addr->sa_family != AF_UNSPEC) { |
b8a58aa6 KI |
1364 | err = unix_validate_addr(sunaddr, alen); |
1365 | if (err) | |
1366 | goto out; | |
1367 | ||
859051dd DDM |
1368 | err = BPF_CGROUP_RUN_PROG_UNIX_CONNECT_LOCK(sk, addr, &alen); |
1369 | if (err) | |
1370 | goto out; | |
1371 | ||
5e2ff670 AM |
1372 | if ((test_bit(SOCK_PASSCRED, &sock->flags) || |
1373 | test_bit(SOCK_PASSPIDFD, &sock->flags)) && | |
f7ed31f4 KI |
1374 | !unix_sk(sk)->addr) { |
1375 | err = unix_autobind(sk); | |
1376 | if (err) | |
1377 | goto out; | |
1378 | } | |
1da177e4 | 1379 | |
278a3de5 | 1380 | restart: |
340c3d33 | 1381 | other = unix_find_other(sock_net(sk), sunaddr, alen, sock->type); |
aed26f55 KI |
1382 | if (IS_ERR(other)) { |
1383 | err = PTR_ERR(other); | |
1da177e4 | 1384 | goto out; |
aed26f55 | 1385 | } |
1da177e4 | 1386 | |
278a3de5 DM |
1387 | unix_state_double_lock(sk, other); |
1388 | ||
1389 | /* Apparently VFS overslept socket death. Retry. */ | |
1390 | if (sock_flag(other, SOCK_DEAD)) { | |
1391 | unix_state_double_unlock(sk, other); | |
1392 | sock_put(other); | |
1393 | goto restart; | |
1394 | } | |
1da177e4 LT |
1395 | |
1396 | err = -EPERM; | |
1397 | if (!unix_may_send(sk, other)) | |
1398 | goto out_unlock; | |
1399 | ||
1400 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
1401 | if (err) | |
1402 | goto out_unlock; | |
1403 | ||
dc56ad70 | 1404 | sk->sk_state = other->sk_state = TCP_ESTABLISHED; |
1da177e4 LT |
1405 | } else { |
1406 | /* | |
1407 | * 1003.1g breaking connected state with AF_UNSPEC | |
1408 | */ | |
1409 | other = NULL; | |
278a3de5 | 1410 | unix_state_double_lock(sk, other); |
1da177e4 LT |
1411 | } |
1412 | ||
1413 | /* | |
1414 | * If it was connected, reconnect. | |
1415 | */ | |
1416 | if (unix_peer(sk)) { | |
1417 | struct sock *old_peer = unix_peer(sk); | |
dc56ad70 | 1418 | |
e27dfcea | 1419 | unix_peer(sk) = other; |
dc56ad70 ED |
1420 | if (!other) |
1421 | sk->sk_state = TCP_CLOSE; | |
7d267278 RW |
1422 | unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer); |
1423 | ||
278a3de5 | 1424 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1425 | |
1426 | if (other != old_peer) | |
1427 | unix_dgram_disconnected(sk, old_peer); | |
1428 | sock_put(old_peer); | |
1429 | } else { | |
e27dfcea | 1430 | unix_peer(sk) = other; |
278a3de5 | 1431 | unix_state_double_unlock(sk, other); |
1da177e4 | 1432 | } |
83301b53 | 1433 | |
ac7bfa62 | 1434 | return 0; |
1da177e4 LT |
1435 | |
1436 | out_unlock: | |
278a3de5 | 1437 | unix_state_double_unlock(sk, other); |
1da177e4 LT |
1438 | sock_put(other); |
1439 | out: | |
1440 | return err; | |
1441 | } | |
1442 | ||
1443 | static long unix_wait_for_peer(struct sock *other, long timeo) | |
48851e9e | 1444 | __releases(&unix_sk(other)->lock) |
1da177e4 LT |
1445 | { |
1446 | struct unix_sock *u = unix_sk(other); | |
1447 | int sched; | |
1448 | DEFINE_WAIT(wait); | |
1449 | ||
1450 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); | |
1451 | ||
1452 | sched = !sock_flag(other, SOCK_DEAD) && | |
1453 | !(other->sk_shutdown & RCV_SHUTDOWN) && | |
679ed006 | 1454 | unix_recvq_full_lockless(other); |
1da177e4 | 1455 | |
1c92b4e5 | 1456 | unix_state_unlock(other); |
1da177e4 LT |
1457 | |
1458 | if (sched) | |
1459 | timeo = schedule_timeout(timeo); | |
1460 | ||
1461 | finish_wait(&u->peer_wait, &wait); | |
1462 | return timeo; | |
1463 | } | |
1464 | ||
1465 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1466 | int addr_len, int flags) | |
1467 | { | |
e27dfcea | 1468 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
340c3d33 | 1469 | struct sock *sk = sock->sk, *newsk = NULL, *other = NULL; |
1da177e4 | 1470 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
340c3d33 | 1471 | struct net *net = sock_net(sk); |
1da177e4 | 1472 | struct sk_buff *skb = NULL; |
1da177e4 | 1473 | long timeo; |
340c3d33 KI |
1474 | int err; |
1475 | int st; | |
1da177e4 | 1476 | |
b8a58aa6 KI |
1477 | err = unix_validate_addr(sunaddr, addr_len); |
1478 | if (err) | |
1479 | goto out; | |
1480 | ||
859051dd DDM |
1481 | err = BPF_CGROUP_RUN_PROG_UNIX_CONNECT_LOCK(sk, uaddr, &addr_len); |
1482 | if (err) | |
1483 | goto out; | |
1484 | ||
5e2ff670 AM |
1485 | if ((test_bit(SOCK_PASSCRED, &sock->flags) || |
1486 | test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { | |
f7ed31f4 KI |
1487 | err = unix_autobind(sk); |
1488 | if (err) | |
1489 | goto out; | |
1490 | } | |
1da177e4 LT |
1491 | |
1492 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); | |
1493 | ||
1494 | /* First of all allocate resources. | |
1495 | If we will make it after state is locked, | |
1496 | we will have to recheck all again in any case. | |
1497 | */ | |
1498 | ||
1da177e4 | 1499 | /* create new sock for complete connection */ |
340c3d33 | 1500 | newsk = unix_create1(net, NULL, 0, sock->type); |
f4bd73b5 KI |
1501 | if (IS_ERR(newsk)) { |
1502 | err = PTR_ERR(newsk); | |
1503 | newsk = NULL; | |
1da177e4 | 1504 | goto out; |
f4bd73b5 KI |
1505 | } |
1506 | ||
1507 | err = -ENOMEM; | |
1da177e4 LT |
1508 | |
1509 | /* Allocate skb for sending to listening sock */ | |
1510 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); | |
1511 | if (skb == NULL) | |
1512 | goto out; | |
1513 | ||
1514 | restart: | |
1515 | /* Find listening sock. */ | |
d2d8c9fd | 1516 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type); |
aed26f55 KI |
1517 | if (IS_ERR(other)) { |
1518 | err = PTR_ERR(other); | |
1519 | other = NULL; | |
1da177e4 | 1520 | goto out; |
aed26f55 | 1521 | } |
1da177e4 LT |
1522 | |
1523 | /* Latch state of peer */ | |
1c92b4e5 | 1524 | unix_state_lock(other); |
1da177e4 LT |
1525 | |
1526 | /* Apparently VFS overslept socket death. Retry. */ | |
1527 | if (sock_flag(other, SOCK_DEAD)) { | |
1c92b4e5 | 1528 | unix_state_unlock(other); |
1da177e4 LT |
1529 | sock_put(other); |
1530 | goto restart; | |
1531 | } | |
1532 | ||
1533 | err = -ECONNREFUSED; | |
1534 | if (other->sk_state != TCP_LISTEN) | |
1535 | goto out_unlock; | |
77238f2b TS |
1536 | if (other->sk_shutdown & RCV_SHUTDOWN) |
1537 | goto out_unlock; | |
1da177e4 | 1538 | |
3c73419c | 1539 | if (unix_recvq_full(other)) { |
1da177e4 LT |
1540 | err = -EAGAIN; |
1541 | if (!timeo) | |
1542 | goto out_unlock; | |
1543 | ||
1544 | timeo = unix_wait_for_peer(other, timeo); | |
1545 | ||
1546 | err = sock_intr_errno(timeo); | |
1547 | if (signal_pending(current)) | |
1548 | goto out; | |
1549 | sock_put(other); | |
1550 | goto restart; | |
ac7bfa62 | 1551 | } |
1da177e4 LT |
1552 | |
1553 | /* Latch our state. | |
1554 | ||
e5537bfc | 1555 | It is tricky place. We need to grab our state lock and cannot |
1da177e4 LT |
1556 | drop lock on peer. It is dangerous because deadlock is |
1557 | possible. Connect to self case and simultaneous | |
1558 | attempt to connect are eliminated by checking socket | |
1559 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we | |
1560 | check this before attempt to grab lock. | |
1561 | ||
1562 | Well, and we have to recheck the state after socket locked. | |
1563 | */ | |
1564 | st = sk->sk_state; | |
1565 | ||
1566 | switch (st) { | |
1567 | case TCP_CLOSE: | |
1568 | /* This is ok... continue with connect */ | |
1569 | break; | |
1570 | case TCP_ESTABLISHED: | |
1571 | /* Socket is already connected */ | |
1572 | err = -EISCONN; | |
1573 | goto out_unlock; | |
1574 | default: | |
1575 | err = -EINVAL; | |
1576 | goto out_unlock; | |
1577 | } | |
1578 | ||
4d322dce | 1579 | unix_state_lock_nested(sk, U_LOCK_SECOND); |
1da177e4 LT |
1580 | |
1581 | if (sk->sk_state != st) { | |
1c92b4e5 DM |
1582 | unix_state_unlock(sk); |
1583 | unix_state_unlock(other); | |
1da177e4 LT |
1584 | sock_put(other); |
1585 | goto restart; | |
1586 | } | |
1587 | ||
3610cda5 | 1588 | err = security_unix_stream_connect(sk, other, newsk); |
1da177e4 | 1589 | if (err) { |
1c92b4e5 | 1590 | unix_state_unlock(sk); |
1da177e4 LT |
1591 | goto out_unlock; |
1592 | } | |
1593 | ||
1594 | /* The way is open! Fastly set all the necessary fields... */ | |
1595 | ||
1596 | sock_hold(sk); | |
1597 | unix_peer(newsk) = sk; | |
1598 | newsk->sk_state = TCP_ESTABLISHED; | |
1599 | newsk->sk_type = sk->sk_type; | |
109f6e39 | 1600 | init_peercred(newsk); |
1da177e4 | 1601 | newu = unix_sk(newsk); |
eaefd110 | 1602 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
1da177e4 LT |
1603 | otheru = unix_sk(other); |
1604 | ||
ae3b5641 AV |
1605 | /* copy address information from listening to new sock |
1606 | * | |
1607 | * The contents of *(otheru->addr) and otheru->path | |
1608 | * are seen fully set up here, since we have found | |
2f7ca90a KI |
1609 | * otheru in hash under its lock. Insertion into the |
1610 | * hash chain we'd found it in had been done in an | |
1611 | * earlier critical area protected by the chain's lock, | |
ae3b5641 AV |
1612 | * the same one where we'd set *(otheru->addr) contents, |
1613 | * as well as otheru->path and otheru->addr itself. | |
1614 | * | |
1615 | * Using smp_store_release() here to set newu->addr | |
1616 | * is enough to make those stores, as well as stores | |
1617 | * to newu->path visible to anyone who gets newu->addr | |
1618 | * by smp_load_acquire(). IOW, the same warranties | |
1619 | * as for unix_sock instances bound in unix_bind() or | |
1620 | * in unix_autobind(). | |
1621 | */ | |
40ffe67d AV |
1622 | if (otheru->path.dentry) { |
1623 | path_get(&otheru->path); | |
1624 | newu->path = otheru->path; | |
1da177e4 | 1625 | } |
ae3b5641 AV |
1626 | refcount_inc(&otheru->addr->refcnt); |
1627 | smp_store_release(&newu->addr, otheru->addr); | |
1da177e4 LT |
1628 | |
1629 | /* Set credentials */ | |
109f6e39 | 1630 | copy_peercred(sk, other); |
1da177e4 | 1631 | |
1da177e4 LT |
1632 | sock->state = SS_CONNECTED; |
1633 | sk->sk_state = TCP_ESTABLISHED; | |
830a1e5c BL |
1634 | sock_hold(newsk); |
1635 | ||
4e857c58 | 1636 | smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */ |
830a1e5c | 1637 | unix_peer(sk) = newsk; |
1da177e4 | 1638 | |
1c92b4e5 | 1639 | unix_state_unlock(sk); |
1da177e4 | 1640 | |
4e03d073 | 1641 | /* take ten and send info to listening sock */ |
1da177e4 LT |
1642 | spin_lock(&other->sk_receive_queue.lock); |
1643 | __skb_queue_tail(&other->sk_receive_queue, skb); | |
1da177e4 | 1644 | spin_unlock(&other->sk_receive_queue.lock); |
1c92b4e5 | 1645 | unix_state_unlock(other); |
676d2369 | 1646 | other->sk_data_ready(other); |
1da177e4 LT |
1647 | sock_put(other); |
1648 | return 0; | |
1649 | ||
1650 | out_unlock: | |
1651 | if (other) | |
1c92b4e5 | 1652 | unix_state_unlock(other); |
1da177e4 LT |
1653 | |
1654 | out: | |
40d44446 | 1655 | kfree_skb(skb); |
1da177e4 LT |
1656 | if (newsk) |
1657 | unix_release_sock(newsk, 0); | |
1658 | if (other) | |
1659 | sock_put(other); | |
1660 | return err; | |
1661 | } | |
1662 | ||
1663 | static int unix_socketpair(struct socket *socka, struct socket *sockb) | |
1664 | { | |
e27dfcea | 1665 | struct sock *ska = socka->sk, *skb = sockb->sk; |
1da177e4 LT |
1666 | |
1667 | /* Join our sockets back to back */ | |
1668 | sock_hold(ska); | |
1669 | sock_hold(skb); | |
e27dfcea JK |
1670 | unix_peer(ska) = skb; |
1671 | unix_peer(skb) = ska; | |
109f6e39 EB |
1672 | init_peercred(ska); |
1673 | init_peercred(skb); | |
1da177e4 | 1674 | |
83301b53 CW |
1675 | ska->sk_state = TCP_ESTABLISHED; |
1676 | skb->sk_state = TCP_ESTABLISHED; | |
1677 | socka->state = SS_CONNECTED; | |
1678 | sockb->state = SS_CONNECTED; | |
1da177e4 LT |
1679 | return 0; |
1680 | } | |
1681 | ||
90c6bd34 DB |
1682 | static void unix_sock_inherit_flags(const struct socket *old, |
1683 | struct socket *new) | |
1684 | { | |
1685 | if (test_bit(SOCK_PASSCRED, &old->flags)) | |
1686 | set_bit(SOCK_PASSCRED, &new->flags); | |
5e2ff670 AM |
1687 | if (test_bit(SOCK_PASSPIDFD, &old->flags)) |
1688 | set_bit(SOCK_PASSPIDFD, &new->flags); | |
90c6bd34 DB |
1689 | if (test_bit(SOCK_PASSSEC, &old->flags)) |
1690 | set_bit(SOCK_PASSSEC, &new->flags); | |
1691 | } | |
1692 | ||
cdfbabfb DH |
1693 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags, |
1694 | bool kern) | |
1da177e4 LT |
1695 | { |
1696 | struct sock *sk = sock->sk; | |
1697 | struct sock *tsk; | |
1698 | struct sk_buff *skb; | |
1699 | int err; | |
1700 | ||
1701 | err = -EOPNOTSUPP; | |
6eba6a37 | 1702 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
1da177e4 LT |
1703 | goto out; |
1704 | ||
1705 | err = -EINVAL; | |
1706 | if (sk->sk_state != TCP_LISTEN) | |
1707 | goto out; | |
1708 | ||
1709 | /* If socket state is TCP_LISTEN it cannot change (for now...), | |
1710 | * so that no locks are necessary. | |
1711 | */ | |
1712 | ||
f4b41f06 OH |
1713 | skb = skb_recv_datagram(sk, (flags & O_NONBLOCK) ? MSG_DONTWAIT : 0, |
1714 | &err); | |
1da177e4 LT |
1715 | if (!skb) { |
1716 | /* This means receive shutdown. */ | |
1717 | if (err == 0) | |
1718 | err = -EINVAL; | |
1719 | goto out; | |
1720 | } | |
1721 | ||
1722 | tsk = skb->sk; | |
1723 | skb_free_datagram(sk, skb); | |
1724 | wake_up_interruptible(&unix_sk(sk)->peer_wait); | |
1725 | ||
1726 | /* attach accepted sock to socket */ | |
1c92b4e5 | 1727 | unix_state_lock(tsk); |
1da177e4 | 1728 | newsock->state = SS_CONNECTED; |
90c6bd34 | 1729 | unix_sock_inherit_flags(sock, newsock); |
1da177e4 | 1730 | sock_graft(tsk, newsock); |
1c92b4e5 | 1731 | unix_state_unlock(tsk); |
1da177e4 LT |
1732 | return 0; |
1733 | ||
1734 | out: | |
1735 | return err; | |
1736 | } | |
1737 | ||
1738 | ||
9b2c45d4 | 1739 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer) |
1da177e4 LT |
1740 | { |
1741 | struct sock *sk = sock->sk; | |
ae3b5641 | 1742 | struct unix_address *addr; |
13cfa97b | 1743 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
1da177e4 LT |
1744 | int err = 0; |
1745 | ||
1746 | if (peer) { | |
1747 | sk = unix_peer_get(sk); | |
1748 | ||
1749 | err = -ENOTCONN; | |
1750 | if (!sk) | |
1751 | goto out; | |
1752 | err = 0; | |
1753 | } else { | |
1754 | sock_hold(sk); | |
1755 | } | |
1756 | ||
ae3b5641 AV |
1757 | addr = smp_load_acquire(&unix_sk(sk)->addr); |
1758 | if (!addr) { | |
1da177e4 LT |
1759 | sunaddr->sun_family = AF_UNIX; |
1760 | sunaddr->sun_path[0] = 0; | |
755662ce | 1761 | err = offsetof(struct sockaddr_un, sun_path); |
1da177e4 | 1762 | } else { |
9b2c45d4 DV |
1763 | err = addr->len; |
1764 | memcpy(sunaddr, addr->name, addr->len); | |
859051dd DDM |
1765 | |
1766 | if (peer) | |
1767 | BPF_CGROUP_RUN_SA_PROG(sk, uaddr, &err, | |
1768 | CGROUP_UNIX_GETPEERNAME); | |
1769 | else | |
1770 | BPF_CGROUP_RUN_SA_PROG(sk, uaddr, &err, | |
1771 | CGROUP_UNIX_GETSOCKNAME); | |
1da177e4 | 1772 | } |
1da177e4 LT |
1773 | sock_put(sk); |
1774 | out: | |
1775 | return err; | |
1776 | } | |
1777 | ||
cbcf0112 MS |
1778 | static void unix_peek_fds(struct scm_cookie *scm, struct sk_buff *skb) |
1779 | { | |
1780 | scm->fp = scm_fp_dup(UNIXCB(skb).fp); | |
1781 | ||
1782 | /* | |
1783 | * Garbage collection of unix sockets starts by selecting a set of | |
1784 | * candidate sockets which have reference only from being in flight | |
1785 | * (total_refs == inflight_refs). This condition is checked once during | |
1786 | * the candidate collection phase, and candidates are marked as such, so | |
1787 | * that non-candidates can later be ignored. While inflight_refs is | |
1788 | * protected by unix_gc_lock, total_refs (file count) is not, hence this | |
1789 | * is an instantaneous decision. | |
1790 | * | |
1791 | * Once a candidate, however, the socket must not be reinstalled into a | |
1792 | * file descriptor while the garbage collection is in progress. | |
1793 | * | |
1794 | * If the above conditions are met, then the directed graph of | |
1795 | * candidates (*) does not change while unix_gc_lock is held. | |
1796 | * | |
1797 | * Any operations that changes the file count through file descriptors | |
1798 | * (dup, close, sendmsg) does not change the graph since candidates are | |
1799 | * not installed in fds. | |
1800 | * | |
1801 | * Dequeing a candidate via recvmsg would install it into an fd, but | |
1802 | * that takes unix_gc_lock to decrement the inflight count, so it's | |
1803 | * serialized with garbage collection. | |
1804 | * | |
1805 | * MSG_PEEK is special in that it does not change the inflight count, | |
1806 | * yet does install the socket into an fd. The following lock/unlock | |
1807 | * pair is to ensure serialization with garbage collection. It must be | |
1808 | * done between incrementing the file count and installing the file into | |
1809 | * an fd. | |
1810 | * | |
1811 | * If garbage collection starts after the barrier provided by the | |
1812 | * lock/unlock, then it will see the elevated refcount and not mark this | |
1813 | * as a candidate. If a garbage collection is already in progress | |
1814 | * before the file count was incremented, then the lock/unlock pair will | |
1815 | * ensure that garbage collection is finished before progressing to | |
1816 | * installing the fd. | |
1817 | * | |
1818 | * (*) A -> B where B is on the queue of A or B is on the queue of C | |
1819 | * which is on the queue of listening socket A. | |
1820 | */ | |
1821 | spin_lock(&unix_gc_lock); | |
1822 | spin_unlock(&unix_gc_lock); | |
1823 | } | |
1824 | ||
f78a5fda | 1825 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
7361c36c EB |
1826 | { |
1827 | int err = 0; | |
16e57262 | 1828 | |
f78a5fda | 1829 | UNIXCB(skb).pid = get_pid(scm->pid); |
6b0ee8c0 EB |
1830 | UNIXCB(skb).uid = scm->creds.uid; |
1831 | UNIXCB(skb).gid = scm->creds.gid; | |
7361c36c | 1832 | UNIXCB(skb).fp = NULL; |
37a9a8df | 1833 | unix_get_secdata(scm, skb); |
7361c36c EB |
1834 | if (scm->fp && send_fds) |
1835 | err = unix_attach_fds(scm, skb); | |
1836 | ||
1837 | skb->destructor = unix_destruct_scm; | |
1838 | return err; | |
1839 | } | |
1840 | ||
9490f886 HFS |
1841 | static bool unix_passcred_enabled(const struct socket *sock, |
1842 | const struct sock *other) | |
1843 | { | |
1844 | return test_bit(SOCK_PASSCRED, &sock->flags) || | |
5e2ff670 | 1845 | test_bit(SOCK_PASSPIDFD, &sock->flags) || |
9490f886 | 1846 | !other->sk_socket || |
5e2ff670 AM |
1847 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags) || |
1848 | test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags); | |
9490f886 HFS |
1849 | } |
1850 | ||
16e57262 ED |
1851 | /* |
1852 | * Some apps rely on write() giving SCM_CREDENTIALS | |
1853 | * We include credentials if source or destination socket | |
1854 | * asserted SOCK_PASSCRED. | |
1855 | */ | |
1856 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, | |
1857 | const struct sock *other) | |
1858 | { | |
6b0ee8c0 | 1859 | if (UNIXCB(skb).pid) |
16e57262 | 1860 | return; |
9490f886 | 1861 | if (unix_passcred_enabled(sock, other)) { |
16e57262 | 1862 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
6e0895c2 | 1863 | current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid); |
16e57262 ED |
1864 | } |
1865 | } | |
1866 | ||
9490f886 HFS |
1867 | static bool unix_skb_scm_eq(struct sk_buff *skb, |
1868 | struct scm_cookie *scm) | |
1869 | { | |
b146cbf2 KC |
1870 | return UNIXCB(skb).pid == scm->pid && |
1871 | uid_eq(UNIXCB(skb).uid, scm->creds.uid) && | |
1872 | gid_eq(UNIXCB(skb).gid, scm->creds.gid) && | |
9490f886 HFS |
1873 | unix_secdata_eq(scm, skb); |
1874 | } | |
1875 | ||
3c32da19 KT |
1876 | static void scm_stat_add(struct sock *sk, struct sk_buff *skb) |
1877 | { | |
1878 | struct scm_fp_list *fp = UNIXCB(skb).fp; | |
1879 | struct unix_sock *u = unix_sk(sk); | |
1880 | ||
3c32da19 | 1881 | if (unlikely(fp && fp->count)) |
7782040b | 1882 | atomic_add(fp->count, &u->scm_stat.nr_fds); |
3c32da19 KT |
1883 | } |
1884 | ||
1885 | static void scm_stat_del(struct sock *sk, struct sk_buff *skb) | |
1886 | { | |
1887 | struct scm_fp_list *fp = UNIXCB(skb).fp; | |
1888 | struct unix_sock *u = unix_sk(sk); | |
1889 | ||
3c32da19 | 1890 | if (unlikely(fp && fp->count)) |
7782040b | 1891 | atomic_sub(fp->count, &u->scm_stat.nr_fds); |
3c32da19 KT |
1892 | } |
1893 | ||
1da177e4 LT |
1894 | /* |
1895 | * Send AF_UNIX data. | |
1896 | */ | |
1897 | ||
1b784140 YX |
1898 | static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, |
1899 | size_t len) | |
1da177e4 | 1900 | { |
342dfc30 | 1901 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); |
340c3d33 KI |
1902 | struct sock *sk = sock->sk, *other = NULL; |
1903 | struct unix_sock *u = unix_sk(sk); | |
7cc05662 | 1904 | struct scm_cookie scm; |
340c3d33 | 1905 | struct sk_buff *skb; |
eb6a2481 | 1906 | int data_len = 0; |
7d267278 | 1907 | int sk_locked; |
340c3d33 KI |
1908 | long timeo; |
1909 | int err; | |
1da177e4 | 1910 | |
5f23b734 | 1911 | wait_for_unix_gc(); |
7cc05662 | 1912 | err = scm_send(sock, msg, &scm, false); |
1da177e4 LT |
1913 | if (err < 0) |
1914 | return err; | |
1915 | ||
1916 | err = -EOPNOTSUPP; | |
1917 | if (msg->msg_flags&MSG_OOB) | |
1918 | goto out; | |
1919 | ||
1920 | if (msg->msg_namelen) { | |
b8a58aa6 KI |
1921 | err = unix_validate_addr(sunaddr, msg->msg_namelen); |
1922 | if (err) | |
1923 | goto out; | |
859051dd DDM |
1924 | |
1925 | err = BPF_CGROUP_RUN_PROG_UNIX_SENDMSG_LOCK(sk, | |
1926 | msg->msg_name, | |
1927 | &msg->msg_namelen, | |
1928 | NULL); | |
1929 | if (err) | |
1930 | goto out; | |
1da177e4 LT |
1931 | } else { |
1932 | sunaddr = NULL; | |
1933 | err = -ENOTCONN; | |
1934 | other = unix_peer_get(sk); | |
1935 | if (!other) | |
1936 | goto out; | |
1937 | } | |
1938 | ||
5e2ff670 AM |
1939 | if ((test_bit(SOCK_PASSCRED, &sock->flags) || |
1940 | test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { | |
f7ed31f4 KI |
1941 | err = unix_autobind(sk); |
1942 | if (err) | |
1943 | goto out; | |
1944 | } | |
1da177e4 LT |
1945 | |
1946 | err = -EMSGSIZE; | |
1947 | if (len > sk->sk_sndbuf - 32) | |
1948 | goto out; | |
1949 | ||
31ff6aa5 | 1950 | if (len > SKB_MAX_ALLOC) { |
eb6a2481 ED |
1951 | data_len = min_t(size_t, |
1952 | len - SKB_MAX_ALLOC, | |
1953 | MAX_SKB_FRAGS * PAGE_SIZE); | |
31ff6aa5 KT |
1954 | data_len = PAGE_ALIGN(data_len); |
1955 | ||
1956 | BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE); | |
1957 | } | |
eb6a2481 ED |
1958 | |
1959 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, | |
28d64271 ED |
1960 | msg->msg_flags & MSG_DONTWAIT, &err, |
1961 | PAGE_ALLOC_COSTLY_ORDER); | |
e27dfcea | 1962 | if (skb == NULL) |
1da177e4 LT |
1963 | goto out; |
1964 | ||
7cc05662 | 1965 | err = unix_scm_to_skb(&scm, skb, true); |
25888e30 | 1966 | if (err < 0) |
7361c36c | 1967 | goto out_free; |
877ce7c1 | 1968 | |
eb6a2481 ED |
1969 | skb_put(skb, len - data_len); |
1970 | skb->data_len = data_len; | |
1971 | skb->len = len; | |
c0371da6 | 1972 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len); |
1da177e4 LT |
1973 | if (err) |
1974 | goto out_free; | |
1975 | ||
1976 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
1977 | ||
1978 | restart: | |
1979 | if (!other) { | |
1980 | err = -ECONNRESET; | |
1981 | if (sunaddr == NULL) | |
1982 | goto out_free; | |
1983 | ||
340c3d33 | 1984 | other = unix_find_other(sock_net(sk), sunaddr, msg->msg_namelen, |
d2d8c9fd | 1985 | sk->sk_type); |
aed26f55 KI |
1986 | if (IS_ERR(other)) { |
1987 | err = PTR_ERR(other); | |
1988 | other = NULL; | |
1da177e4 | 1989 | goto out_free; |
aed26f55 | 1990 | } |
1da177e4 LT |
1991 | } |
1992 | ||
d6ae3bae AC |
1993 | if (sk_filter(other, skb) < 0) { |
1994 | /* Toss the packet but do not return any error to the sender */ | |
1995 | err = len; | |
1996 | goto out_free; | |
1997 | } | |
1998 | ||
7d267278 | 1999 | sk_locked = 0; |
1c92b4e5 | 2000 | unix_state_lock(other); |
7d267278 | 2001 | restart_locked: |
1da177e4 LT |
2002 | err = -EPERM; |
2003 | if (!unix_may_send(sk, other)) | |
2004 | goto out_unlock; | |
2005 | ||
7d267278 | 2006 | if (unlikely(sock_flag(other, SOCK_DEAD))) { |
1da177e4 LT |
2007 | /* |
2008 | * Check with 1003.1g - what should | |
2009 | * datagram error | |
2010 | */ | |
1c92b4e5 | 2011 | unix_state_unlock(other); |
1da177e4 LT |
2012 | sock_put(other); |
2013 | ||
7d267278 RW |
2014 | if (!sk_locked) |
2015 | unix_state_lock(sk); | |
2016 | ||
1da177e4 | 2017 | err = 0; |
3ff8bff7 KT |
2018 | if (sk->sk_type == SOCK_SEQPACKET) { |
2019 | /* We are here only when racing with unix_release_sock() | |
2020 | * is clearing @other. Never change state to TCP_CLOSE | |
2021 | * unlike SOCK_DGRAM wants. | |
2022 | */ | |
2023 | unix_state_unlock(sk); | |
2024 | err = -EPIPE; | |
2025 | } else if (unix_peer(sk) == other) { | |
e27dfcea | 2026 | unix_peer(sk) = NULL; |
7d267278 RW |
2027 | unix_dgram_peer_wake_disconnect_wakeup(sk, other); |
2028 | ||
3ff8bff7 | 2029 | sk->sk_state = TCP_CLOSE; |
1c92b4e5 | 2030 | unix_state_unlock(sk); |
1da177e4 LT |
2031 | |
2032 | unix_dgram_disconnected(sk, other); | |
2033 | sock_put(other); | |
2034 | err = -ECONNREFUSED; | |
2035 | } else { | |
1c92b4e5 | 2036 | unix_state_unlock(sk); |
1da177e4 LT |
2037 | } |
2038 | ||
2039 | other = NULL; | |
2040 | if (err) | |
2041 | goto out_free; | |
2042 | goto restart; | |
2043 | } | |
2044 | ||
2045 | err = -EPIPE; | |
2046 | if (other->sk_shutdown & RCV_SHUTDOWN) | |
2047 | goto out_unlock; | |
2048 | ||
2049 | if (sk->sk_type != SOCK_SEQPACKET) { | |
2050 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); | |
2051 | if (err) | |
2052 | goto out_unlock; | |
2053 | } | |
2054 | ||
a5527dda RW |
2055 | /* other == sk && unix_peer(other) != sk if |
2056 | * - unix_peer(sk) == NULL, destination address bound to sk | |
2057 | * - unix_peer(sk) == sk by time of get but disconnected before lock | |
2058 | */ | |
2059 | if (other != sk && | |
86b18aaa QC |
2060 | unlikely(unix_peer(other) != sk && |
2061 | unix_recvq_full_lockless(other))) { | |
7d267278 RW |
2062 | if (timeo) { |
2063 | timeo = unix_wait_for_peer(other, timeo); | |
2064 | ||
2065 | err = sock_intr_errno(timeo); | |
2066 | if (signal_pending(current)) | |
2067 | goto out_free; | |
2068 | ||
2069 | goto restart; | |
1da177e4 LT |
2070 | } |
2071 | ||
7d267278 RW |
2072 | if (!sk_locked) { |
2073 | unix_state_unlock(other); | |
2074 | unix_state_double_lock(sk, other); | |
2075 | } | |
1da177e4 | 2076 | |
7d267278 RW |
2077 | if (unix_peer(sk) != other || |
2078 | unix_dgram_peer_wake_me(sk, other)) { | |
2079 | err = -EAGAIN; | |
2080 | sk_locked = 1; | |
2081 | goto out_unlock; | |
2082 | } | |
1da177e4 | 2083 | |
7d267278 RW |
2084 | if (!sk_locked) { |
2085 | sk_locked = 1; | |
2086 | goto restart_locked; | |
2087 | } | |
1da177e4 LT |
2088 | } |
2089 | ||
7d267278 RW |
2090 | if (unlikely(sk_locked)) |
2091 | unix_state_unlock(sk); | |
2092 | ||
3f66116e AC |
2093 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
2094 | __net_timestamp(skb); | |
16e57262 | 2095 | maybe_add_creds(skb, sock, other); |
3c32da19 | 2096 | scm_stat_add(other, skb); |
7782040b | 2097 | skb_queue_tail(&other->sk_receive_queue, skb); |
1c92b4e5 | 2098 | unix_state_unlock(other); |
676d2369 | 2099 | other->sk_data_ready(other); |
1da177e4 | 2100 | sock_put(other); |
7cc05662 | 2101 | scm_destroy(&scm); |
1da177e4 LT |
2102 | return len; |
2103 | ||
2104 | out_unlock: | |
7d267278 RW |
2105 | if (sk_locked) |
2106 | unix_state_unlock(sk); | |
1c92b4e5 | 2107 | unix_state_unlock(other); |
1da177e4 LT |
2108 | out_free: |
2109 | kfree_skb(skb); | |
2110 | out: | |
2111 | if (other) | |
2112 | sock_put(other); | |
7cc05662 | 2113 | scm_destroy(&scm); |
1da177e4 LT |
2114 | return err; |
2115 | } | |
2116 | ||
e370a723 | 2117 | /* We use paged skbs for stream sockets, and limit occupancy to 32768 |
d4e9a408 | 2118 | * bytes, and a minimum of a full page. |
e370a723 ED |
2119 | */ |
2120 | #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) | |
ac7bfa62 | 2121 | |
4edf21aa | 2122 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
2aab4b96 ED |
2123 | static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other, |
2124 | struct scm_cookie *scm, bool fds_sent) | |
314001f0 RS |
2125 | { |
2126 | struct unix_sock *ousk = unix_sk(other); | |
2127 | struct sk_buff *skb; | |
2128 | int err = 0; | |
2129 | ||
2130 | skb = sock_alloc_send_skb(sock->sk, 1, msg->msg_flags & MSG_DONTWAIT, &err); | |
2131 | ||
2132 | if (!skb) | |
2133 | return err; | |
2134 | ||
2aab4b96 ED |
2135 | err = unix_scm_to_skb(scm, skb, !fds_sent); |
2136 | if (err < 0) { | |
2137 | kfree_skb(skb); | |
2138 | return err; | |
2139 | } | |
314001f0 | 2140 | skb_put(skb, 1); |
314001f0 RS |
2141 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, 1); |
2142 | ||
2143 | if (err) { | |
2144 | kfree_skb(skb); | |
2145 | return err; | |
2146 | } | |
2147 | ||
2148 | unix_state_lock(other); | |
19eed721 RS |
2149 | |
2150 | if (sock_flag(other, SOCK_DEAD) || | |
2151 | (other->sk_shutdown & RCV_SHUTDOWN)) { | |
2152 | unix_state_unlock(other); | |
2153 | kfree_skb(skb); | |
2154 | return -EPIPE; | |
2155 | } | |
2156 | ||
314001f0 RS |
2157 | maybe_add_creds(skb, sock, other); |
2158 | skb_get(skb); | |
2159 | ||
2160 | if (ousk->oob_skb) | |
19eed721 | 2161 | consume_skb(ousk->oob_skb); |
314001f0 | 2162 | |
e82025c6 | 2163 | WRITE_ONCE(ousk->oob_skb, skb); |
314001f0 RS |
2164 | |
2165 | scm_stat_add(other, skb); | |
2166 | skb_queue_tail(&other->sk_receive_queue, skb); | |
2167 | sk_send_sigurg(other); | |
2168 | unix_state_unlock(other); | |
2169 | other->sk_data_ready(other); | |
2170 | ||
2171 | return err; | |
2172 | } | |
2173 | #endif | |
2174 | ||
1b784140 YX |
2175 | static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, |
2176 | size_t len) | |
1da177e4 | 2177 | { |
1da177e4 LT |
2178 | struct sock *sk = sock->sk; |
2179 | struct sock *other = NULL; | |
6eba6a37 | 2180 | int err, size; |
f78a5fda | 2181 | struct sk_buff *skb; |
e27dfcea | 2182 | int sent = 0; |
7cc05662 | 2183 | struct scm_cookie scm; |
8ba69ba6 | 2184 | bool fds_sent = false; |
e370a723 | 2185 | int data_len; |
1da177e4 | 2186 | |
5f23b734 | 2187 | wait_for_unix_gc(); |
7cc05662 | 2188 | err = scm_send(sock, msg, &scm, false); |
1da177e4 LT |
2189 | if (err < 0) |
2190 | return err; | |
2191 | ||
2192 | err = -EOPNOTSUPP; | |
314001f0 | 2193 | if (msg->msg_flags & MSG_OOB) { |
4edf21aa | 2194 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
314001f0 RS |
2195 | if (len) |
2196 | len--; | |
2197 | else | |
2198 | #endif | |
2199 | goto out_err; | |
2200 | } | |
1da177e4 LT |
2201 | |
2202 | if (msg->msg_namelen) { | |
2203 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; | |
2204 | goto out_err; | |
2205 | } else { | |
1da177e4 | 2206 | err = -ENOTCONN; |
830a1e5c | 2207 | other = unix_peer(sk); |
1da177e4 LT |
2208 | if (!other) |
2209 | goto out_err; | |
2210 | } | |
2211 | ||
2212 | if (sk->sk_shutdown & SEND_SHUTDOWN) | |
2213 | goto pipe_err; | |
2214 | ||
6eba6a37 | 2215 | while (sent < len) { |
e370a723 | 2216 | size = len - sent; |
1da177e4 | 2217 | |
a0dbf5f8 DH |
2218 | if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { |
2219 | skb = sock_alloc_send_pskb(sk, 0, 0, | |
2220 | msg->msg_flags & MSG_DONTWAIT, | |
2221 | &err, 0); | |
2222 | } else { | |
2223 | /* Keep two messages in the pipe so it schedules better */ | |
2224 | size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); | |
1da177e4 | 2225 | |
a0dbf5f8 DH |
2226 | /* allow fallback to order-0 allocations */ |
2227 | size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); | |
ac7bfa62 | 2228 | |
a0dbf5f8 | 2229 | data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); |
1da177e4 | 2230 | |
a0dbf5f8 | 2231 | data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); |
31ff6aa5 | 2232 | |
a0dbf5f8 DH |
2233 | skb = sock_alloc_send_pskb(sk, size - data_len, data_len, |
2234 | msg->msg_flags & MSG_DONTWAIT, &err, | |
2235 | get_order(UNIX_SKB_FRAGS_SZ)); | |
2236 | } | |
e370a723 | 2237 | if (!skb) |
1da177e4 LT |
2238 | goto out_err; |
2239 | ||
f78a5fda | 2240 | /* Only send the fds in the first buffer */ |
7cc05662 | 2241 | err = unix_scm_to_skb(&scm, skb, !fds_sent); |
25888e30 | 2242 | if (err < 0) { |
7361c36c | 2243 | kfree_skb(skb); |
f78a5fda | 2244 | goto out_err; |
6209344f | 2245 | } |
7361c36c | 2246 | fds_sent = true; |
1da177e4 | 2247 | |
a0dbf5f8 DH |
2248 | if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { |
2249 | err = skb_splice_from_iter(skb, &msg->msg_iter, size, | |
2250 | sk->sk_allocation); | |
2251 | if (err < 0) { | |
2252 | kfree_skb(skb); | |
2253 | goto out_err; | |
2254 | } | |
2255 | size = err; | |
2256 | refcount_add(size, &sk->sk_wmem_alloc); | |
2257 | } else { | |
2258 | skb_put(skb, size - data_len); | |
2259 | skb->data_len = data_len; | |
2260 | skb->len = size; | |
2261 | err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); | |
2262 | if (err) { | |
2263 | kfree_skb(skb); | |
2264 | goto out_err; | |
2265 | } | |
1da177e4 LT |
2266 | } |
2267 | ||
1c92b4e5 | 2268 | unix_state_lock(other); |
1da177e4 LT |
2269 | |
2270 | if (sock_flag(other, SOCK_DEAD) || | |
2271 | (other->sk_shutdown & RCV_SHUTDOWN)) | |
2272 | goto pipe_err_free; | |
2273 | ||
16e57262 | 2274 | maybe_add_creds(skb, sock, other); |
3c32da19 | 2275 | scm_stat_add(other, skb); |
7782040b | 2276 | skb_queue_tail(&other->sk_receive_queue, skb); |
1c92b4e5 | 2277 | unix_state_unlock(other); |
676d2369 | 2278 | other->sk_data_ready(other); |
e27dfcea | 2279 | sent += size; |
1da177e4 | 2280 | } |
1da177e4 | 2281 | |
4edf21aa | 2282 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
314001f0 | 2283 | if (msg->msg_flags & MSG_OOB) { |
2aab4b96 | 2284 | err = queue_oob(sock, msg, other, &scm, fds_sent); |
314001f0 RS |
2285 | if (err) |
2286 | goto out_err; | |
2287 | sent++; | |
2288 | } | |
2289 | #endif | |
2290 | ||
7cc05662 | 2291 | scm_destroy(&scm); |
1da177e4 LT |
2292 | |
2293 | return sent; | |
2294 | ||
2295 | pipe_err_free: | |
1c92b4e5 | 2296 | unix_state_unlock(other); |
1da177e4 LT |
2297 | kfree_skb(skb); |
2298 | pipe_err: | |
6eba6a37 ED |
2299 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
2300 | send_sig(SIGPIPE, current, 0); | |
1da177e4 LT |
2301 | err = -EPIPE; |
2302 | out_err: | |
7cc05662 | 2303 | scm_destroy(&scm); |
1da177e4 LT |
2304 | return sent ? : err; |
2305 | } | |
2306 | ||
1b784140 YX |
2307 | static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg, |
2308 | size_t len) | |
1da177e4 LT |
2309 | { |
2310 | int err; | |
2311 | struct sock *sk = sock->sk; | |
ac7bfa62 | 2312 | |
1da177e4 LT |
2313 | err = sock_error(sk); |
2314 | if (err) | |
2315 | return err; | |
2316 | ||
2317 | if (sk->sk_state != TCP_ESTABLISHED) | |
2318 | return -ENOTCONN; | |
2319 | ||
2320 | if (msg->msg_namelen) | |
2321 | msg->msg_namelen = 0; | |
2322 | ||
1b784140 | 2323 | return unix_dgram_sendmsg(sock, msg, len); |
1da177e4 | 2324 | } |
ac7bfa62 | 2325 | |
1b784140 YX |
2326 | static int unix_seqpacket_recvmsg(struct socket *sock, struct msghdr *msg, |
2327 | size_t size, int flags) | |
a05d2ad1 EB |
2328 | { |
2329 | struct sock *sk = sock->sk; | |
2330 | ||
2331 | if (sk->sk_state != TCP_ESTABLISHED) | |
2332 | return -ENOTCONN; | |
2333 | ||
1b784140 | 2334 | return unix_dgram_recvmsg(sock, msg, size, flags); |
a05d2ad1 EB |
2335 | } |
2336 | ||
1da177e4 LT |
2337 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
2338 | { | |
ae3b5641 | 2339 | struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr); |
1da177e4 | 2340 | |
ae3b5641 AV |
2341 | if (addr) { |
2342 | msg->msg_namelen = addr->len; | |
2343 | memcpy(msg->msg_name, addr->name, addr->len); | |
1da177e4 LT |
2344 | } |
2345 | } | |
2346 | ||
9825d866 CW |
2347 | int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size, |
2348 | int flags) | |
1da177e4 | 2349 | { |
7cc05662 | 2350 | struct scm_cookie scm; |
9825d866 | 2351 | struct socket *sock = sk->sk_socket; |
1da177e4 | 2352 | struct unix_sock *u = unix_sk(sk); |
64874280 RW |
2353 | struct sk_buff *skb, *last; |
2354 | long timeo; | |
fd69c399 | 2355 | int skip; |
1da177e4 LT |
2356 | int err; |
2357 | ||
2358 | err = -EOPNOTSUPP; | |
2359 | if (flags&MSG_OOB) | |
2360 | goto out; | |
2361 | ||
64874280 | 2362 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
1da177e4 | 2363 | |
64874280 | 2364 | do { |
6e1ce3c3 | 2365 | mutex_lock(&u->iolock); |
f55bb7f9 | 2366 | |
64874280 | 2367 | skip = sk_peek_offset(sk, flags); |
b50b0580 | 2368 | skb = __skb_try_recv_datagram(sk, &sk->sk_receive_queue, flags, |
e427cad6 PA |
2369 | &skip, &err, &last); |
2370 | if (skb) { | |
2371 | if (!(flags & MSG_PEEK)) | |
2372 | scm_stat_del(sk, skb); | |
64874280 | 2373 | break; |
e427cad6 | 2374 | } |
64874280 | 2375 | |
6e1ce3c3 | 2376 | mutex_unlock(&u->iolock); |
64874280 RW |
2377 | |
2378 | if (err != -EAGAIN) | |
2379 | break; | |
2380 | } while (timeo && | |
b50b0580 SD |
2381 | !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue, |
2382 | &err, &timeo, last)); | |
64874280 | 2383 | |
6e1ce3c3 | 2384 | if (!skb) { /* implies iolock unlocked */ |
0a112258 FZ |
2385 | unix_state_lock(sk); |
2386 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ | |
2387 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && | |
2388 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
2389 | err = 0; | |
2390 | unix_state_unlock(sk); | |
64874280 | 2391 | goto out; |
0a112258 | 2392 | } |
1da177e4 | 2393 | |
77b75f4d RW |
2394 | if (wq_has_sleeper(&u->peer_wait)) |
2395 | wake_up_interruptible_sync_poll(&u->peer_wait, | |
a9a08845 LT |
2396 | EPOLLOUT | EPOLLWRNORM | |
2397 | EPOLLWRBAND); | |
1da177e4 | 2398 | |
859051dd | 2399 | if (msg->msg_name) { |
1da177e4 LT |
2400 | unix_copy_addr(msg, skb->sk); |
2401 | ||
859051dd DDM |
2402 | BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, |
2403 | msg->msg_name, | |
2404 | &msg->msg_namelen); | |
2405 | } | |
2406 | ||
f55bb7f9 PE |
2407 | if (size > skb->len - skip) |
2408 | size = skb->len - skip; | |
2409 | else if (size < skb->len - skip) | |
1da177e4 LT |
2410 | msg->msg_flags |= MSG_TRUNC; |
2411 | ||
51f3d02b | 2412 | err = skb_copy_datagram_msg(skb, skip, msg, size); |
1da177e4 LT |
2413 | if (err) |
2414 | goto out_free; | |
2415 | ||
3f66116e AC |
2416 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
2417 | __sock_recv_timestamp(msg, sk, skb); | |
2418 | ||
7cc05662 CH |
2419 | memset(&scm, 0, sizeof(scm)); |
2420 | ||
2421 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); | |
2422 | unix_set_secdata(&scm, skb); | |
1da177e4 | 2423 | |
6eba6a37 | 2424 | if (!(flags & MSG_PEEK)) { |
1da177e4 | 2425 | if (UNIXCB(skb).fp) |
7cc05662 | 2426 | unix_detach_fds(&scm, skb); |
f55bb7f9 PE |
2427 | |
2428 | sk_peek_offset_bwd(sk, skb->len); | |
6eba6a37 | 2429 | } else { |
1da177e4 LT |
2430 | /* It is questionable: on PEEK we could: |
2431 | - do not return fds - good, but too simple 8) | |
2432 | - return fds, and do not return them on read (old strategy, | |
2433 | apparently wrong) | |
2434 | - clone fds (I chose it for now, it is the most universal | |
2435 | solution) | |
ac7bfa62 YH |
2436 | |
2437 | POSIX 1003.1g does not actually define this clearly | |
2438 | at all. POSIX 1003.1g doesn't define a lot of things | |
2439 | clearly however! | |
2440 | ||
1da177e4 | 2441 | */ |
f55bb7f9 PE |
2442 | |
2443 | sk_peek_offset_fwd(sk, size); | |
2444 | ||
1da177e4 | 2445 | if (UNIXCB(skb).fp) |
cbcf0112 | 2446 | unix_peek_fds(&scm, skb); |
1da177e4 | 2447 | } |
9f6f9af7 | 2448 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
1da177e4 | 2449 | |
a9c49cc2 | 2450 | scm_recv_unix(sock, msg, &scm, flags); |
1da177e4 LT |
2451 | |
2452 | out_free: | |
6eba6a37 | 2453 | skb_free_datagram(sk, skb); |
6e1ce3c3 | 2454 | mutex_unlock(&u->iolock); |
1da177e4 LT |
2455 | out: |
2456 | return err; | |
2457 | } | |
29df44fa | 2458 | |
9825d866 CW |
2459 | static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, |
2460 | int flags) | |
2461 | { | |
2462 | struct sock *sk = sock->sk; | |
2463 | ||
2464 | #ifdef CONFIG_BPF_SYSCALL | |
94531cfc JW |
2465 | const struct proto *prot = READ_ONCE(sk->sk_prot); |
2466 | ||
2467 | if (prot != &unix_dgram_proto) | |
ec095263 | 2468 | return prot->recvmsg(sk, msg, size, flags, NULL); |
9825d866 CW |
2469 | #endif |
2470 | return __unix_dgram_recvmsg(sk, msg, size, flags); | |
2471 | } | |
2472 | ||
965b57b4 | 2473 | static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor) |
29df44fa | 2474 | { |
d6e3b27c PY |
2475 | struct unix_sock *u = unix_sk(sk); |
2476 | struct sk_buff *skb; | |
78fa0d61 | 2477 | int err; |
29df44fa | 2478 | |
d6e3b27c PY |
2479 | mutex_lock(&u->iolock); |
2480 | skb = skb_recv_datagram(sk, MSG_DONTWAIT, &err); | |
2481 | mutex_unlock(&u->iolock); | |
2482 | if (!skb) | |
2483 | return err; | |
29df44fa | 2484 | |
78fa0d61 | 2485 | return recv_actor(sk, skb); |
29df44fa | 2486 | } |
1da177e4 LT |
2487 | |
2488 | /* | |
79f632c7 | 2489 | * Sleep until more data has arrived. But check for races.. |
1da177e4 | 2490 | */ |
79f632c7 | 2491 | static long unix_stream_data_wait(struct sock *sk, long timeo, |
06a77b07 WC |
2492 | struct sk_buff *last, unsigned int last_len, |
2493 | bool freezable) | |
1da177e4 | 2494 | { |
f5d39b02 | 2495 | unsigned int state = TASK_INTERRUPTIBLE | freezable * TASK_FREEZABLE; |
2b514574 | 2496 | struct sk_buff *tail; |
1da177e4 LT |
2497 | DEFINE_WAIT(wait); |
2498 | ||
1c92b4e5 | 2499 | unix_state_lock(sk); |
1da177e4 LT |
2500 | |
2501 | for (;;) { | |
f5d39b02 | 2502 | prepare_to_wait(sk_sleep(sk), &wait, state); |
1da177e4 | 2503 | |
2b514574 HFS |
2504 | tail = skb_peek_tail(&sk->sk_receive_queue); |
2505 | if (tail != last || | |
2506 | (tail && tail->len != last_len) || | |
1da177e4 LT |
2507 | sk->sk_err || |
2508 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
2509 | signal_pending(current) || | |
2510 | !timeo) | |
2511 | break; | |
2512 | ||
9cd3e072 | 2513 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
1c92b4e5 | 2514 | unix_state_unlock(sk); |
f5d39b02 | 2515 | timeo = schedule_timeout(timeo); |
1c92b4e5 | 2516 | unix_state_lock(sk); |
b48732e4 MS |
2517 | |
2518 | if (sock_flag(sk, SOCK_DEAD)) | |
2519 | break; | |
2520 | ||
9cd3e072 | 2521 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
1da177e4 LT |
2522 | } |
2523 | ||
aa395145 | 2524 | finish_wait(sk_sleep(sk), &wait); |
1c92b4e5 | 2525 | unix_state_unlock(sk); |
1da177e4 LT |
2526 | return timeo; |
2527 | } | |
2528 | ||
e370a723 ED |
2529 | static unsigned int unix_skb_len(const struct sk_buff *skb) |
2530 | { | |
2531 | return skb->len - UNIXCB(skb).consumed; | |
2532 | } | |
2533 | ||
2b514574 HFS |
2534 | struct unix_stream_read_state { |
2535 | int (*recv_actor)(struct sk_buff *, int, int, | |
2536 | struct unix_stream_read_state *); | |
2537 | struct socket *socket; | |
2538 | struct msghdr *msg; | |
2539 | struct pipe_inode_info *pipe; | |
2540 | size_t size; | |
2541 | int flags; | |
2542 | unsigned int splice_flags; | |
2543 | }; | |
2544 | ||
314001f0 RS |
2545 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
2546 | static int unix_stream_recv_urg(struct unix_stream_read_state *state) | |
2547 | { | |
2548 | struct socket *sock = state->socket; | |
2549 | struct sock *sk = sock->sk; | |
2550 | struct unix_sock *u = unix_sk(sk); | |
2551 | int chunk = 1; | |
876c14ad | 2552 | struct sk_buff *oob_skb; |
314001f0 | 2553 | |
876c14ad RS |
2554 | mutex_lock(&u->iolock); |
2555 | unix_state_lock(sk); | |
2556 | ||
2557 | if (sock_flag(sk, SOCK_URGINLINE) || !u->oob_skb) { | |
2558 | unix_state_unlock(sk); | |
2559 | mutex_unlock(&u->iolock); | |
314001f0 | 2560 | return -EINVAL; |
876c14ad | 2561 | } |
314001f0 | 2562 | |
876c14ad | 2563 | oob_skb = u->oob_skb; |
314001f0 | 2564 | |
e82025c6 KI |
2565 | if (!(state->flags & MSG_PEEK)) |
2566 | WRITE_ONCE(u->oob_skb, NULL); | |
4b7b4926 ED |
2567 | else |
2568 | skb_get(oob_skb); | |
876c14ad RS |
2569 | unix_state_unlock(sk); |
2570 | ||
2571 | chunk = state->recv_actor(oob_skb, 0, chunk, state); | |
2572 | ||
4b7b4926 | 2573 | if (!(state->flags & MSG_PEEK)) |
876c14ad | 2574 | UNIXCB(oob_skb).consumed += 1; |
4b7b4926 ED |
2575 | |
2576 | consume_skb(oob_skb); | |
876c14ad RS |
2577 | |
2578 | mutex_unlock(&u->iolock); | |
2579 | ||
2580 | if (chunk < 0) | |
2581 | return -EFAULT; | |
2582 | ||
314001f0 RS |
2583 | state->msg->msg_flags |= MSG_OOB; |
2584 | return 1; | |
2585 | } | |
2586 | ||
2587 | static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, | |
2588 | int flags, int copied) | |
2589 | { | |
2590 | struct unix_sock *u = unix_sk(sk); | |
2591 | ||
2592 | if (!unix_skb_len(skb) && !(flags & MSG_PEEK)) { | |
2593 | skb_unlink(skb, &sk->sk_receive_queue); | |
2594 | consume_skb(skb); | |
2595 | skb = NULL; | |
2596 | } else { | |
2597 | if (skb == u->oob_skb) { | |
2598 | if (copied) { | |
2599 | skb = NULL; | |
2600 | } else if (sock_flag(sk, SOCK_URGINLINE)) { | |
2601 | if (!(flags & MSG_PEEK)) { | |
e82025c6 | 2602 | WRITE_ONCE(u->oob_skb, NULL); |
314001f0 RS |
2603 | consume_skb(skb); |
2604 | } | |
2605 | } else if (!(flags & MSG_PEEK)) { | |
2606 | skb_unlink(skb, &sk->sk_receive_queue); | |
2607 | consume_skb(skb); | |
2608 | skb = skb_peek(&sk->sk_receive_queue); | |
2609 | } | |
2610 | } | |
2611 | } | |
2612 | return skb; | |
2613 | } | |
2614 | #endif | |
2615 | ||
965b57b4 | 2616 | static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor) |
77462de1 JW |
2617 | { |
2618 | if (unlikely(sk->sk_state != TCP_ESTABLISHED)) | |
2619 | return -ENOTCONN; | |
2620 | ||
965b57b4 | 2621 | return unix_read_skb(sk, recv_actor); |
77462de1 JW |
2622 | } |
2623 | ||
06a77b07 WC |
2624 | static int unix_stream_read_generic(struct unix_stream_read_state *state, |
2625 | bool freezable) | |
1da177e4 | 2626 | { |
7cc05662 | 2627 | struct scm_cookie scm; |
2b514574 | 2628 | struct socket *sock = state->socket; |
1da177e4 LT |
2629 | struct sock *sk = sock->sk; |
2630 | struct unix_sock *u = unix_sk(sk); | |
1da177e4 | 2631 | int copied = 0; |
2b514574 | 2632 | int flags = state->flags; |
de144391 | 2633 | int noblock = flags & MSG_DONTWAIT; |
2b514574 | 2634 | bool check_creds = false; |
1da177e4 LT |
2635 | int target; |
2636 | int err = 0; | |
2637 | long timeo; | |
fc0d7536 | 2638 | int skip; |
2b514574 HFS |
2639 | size_t size = state->size; |
2640 | unsigned int last_len; | |
1da177e4 | 2641 | |
1b92ee3d RW |
2642 | if (unlikely(sk->sk_state != TCP_ESTABLISHED)) { |
2643 | err = -EINVAL; | |
1da177e4 | 2644 | goto out; |
1b92ee3d | 2645 | } |
1da177e4 | 2646 | |
1b92ee3d RW |
2647 | if (unlikely(flags & MSG_OOB)) { |
2648 | err = -EOPNOTSUPP; | |
314001f0 | 2649 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
314001f0 | 2650 | err = unix_stream_recv_urg(state); |
314001f0 | 2651 | #endif |
1da177e4 | 2652 | goto out; |
1b92ee3d | 2653 | } |
1da177e4 | 2654 | |
2b514574 | 2655 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, size); |
de144391 | 2656 | timeo = sock_rcvtimeo(sk, noblock); |
1da177e4 | 2657 | |
2b514574 HFS |
2658 | memset(&scm, 0, sizeof(scm)); |
2659 | ||
1da177e4 LT |
2660 | /* Lock the socket to prevent queue disordering |
2661 | * while sleeps in memcpy_tomsg | |
2662 | */ | |
6e1ce3c3 | 2663 | mutex_lock(&u->iolock); |
1da177e4 | 2664 | |
a0917e0b | 2665 | skip = max(sk_peek_offset(sk, flags), 0); |
e9193d60 | 2666 | |
6eba6a37 | 2667 | do { |
1da177e4 | 2668 | int chunk; |
73ed5d25 | 2669 | bool drop_skb; |
79f632c7 | 2670 | struct sk_buff *skb, *last; |
1da177e4 | 2671 | |
18eceb81 | 2672 | redo: |
3c0d2f37 | 2673 | unix_state_lock(sk); |
b48732e4 MS |
2674 | if (sock_flag(sk, SOCK_DEAD)) { |
2675 | err = -ECONNRESET; | |
2676 | goto unlock; | |
2677 | } | |
79f632c7 | 2678 | last = skb = skb_peek(&sk->sk_receive_queue); |
2b514574 | 2679 | last_len = last ? last->len : 0; |
314001f0 RS |
2680 | |
2681 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) | |
2682 | if (skb) { | |
2683 | skb = manage_oob(skb, sk, flags, copied); | |
2684 | if (!skb) { | |
2685 | unix_state_unlock(sk); | |
2686 | if (copied) | |
2687 | break; | |
2688 | goto redo; | |
2689 | } | |
2690 | } | |
2691 | #endif | |
fc0d7536 | 2692 | again: |
6eba6a37 | 2693 | if (skb == NULL) { |
1da177e4 | 2694 | if (copied >= target) |
3c0d2f37 | 2695 | goto unlock; |
1da177e4 LT |
2696 | |
2697 | /* | |
2698 | * POSIX 1003.1g mandates this order. | |
2699 | */ | |
ac7bfa62 | 2700 | |
6eba6a37 ED |
2701 | err = sock_error(sk); |
2702 | if (err) | |
3c0d2f37 | 2703 | goto unlock; |
1da177e4 | 2704 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
3c0d2f37 MS |
2705 | goto unlock; |
2706 | ||
2707 | unix_state_unlock(sk); | |
1b92ee3d RW |
2708 | if (!timeo) { |
2709 | err = -EAGAIN; | |
1da177e4 | 2710 | break; |
1b92ee3d RW |
2711 | } |
2712 | ||
6e1ce3c3 | 2713 | mutex_unlock(&u->iolock); |
1da177e4 | 2714 | |
2b514574 | 2715 | timeo = unix_stream_data_wait(sk, timeo, last, |
06a77b07 | 2716 | last_len, freezable); |
1da177e4 | 2717 | |
3822b5c2 | 2718 | if (signal_pending(current)) { |
1da177e4 | 2719 | err = sock_intr_errno(timeo); |
fa0dc04d | 2720 | scm_destroy(&scm); |
1da177e4 LT |
2721 | goto out; |
2722 | } | |
b3ca9b02 | 2723 | |
6e1ce3c3 | 2724 | mutex_lock(&u->iolock); |
18eceb81 | 2725 | goto redo; |
2b514574 | 2726 | unlock: |
3c0d2f37 MS |
2727 | unix_state_unlock(sk); |
2728 | break; | |
1da177e4 | 2729 | } |
fc0d7536 | 2730 | |
e370a723 ED |
2731 | while (skip >= unix_skb_len(skb)) { |
2732 | skip -= unix_skb_len(skb); | |
79f632c7 | 2733 | last = skb; |
2b514574 | 2734 | last_len = skb->len; |
fc0d7536 | 2735 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
79f632c7 BP |
2736 | if (!skb) |
2737 | goto again; | |
fc0d7536 PE |
2738 | } |
2739 | ||
3c0d2f37 | 2740 | unix_state_unlock(sk); |
1da177e4 LT |
2741 | |
2742 | if (check_creds) { | |
2743 | /* Never glue messages from different writers */ | |
9490f886 | 2744 | if (!unix_skb_scm_eq(skb, &scm)) |
1da177e4 | 2745 | break; |
5e2ff670 AM |
2746 | } else if (test_bit(SOCK_PASSCRED, &sock->flags) || |
2747 | test_bit(SOCK_PASSPIDFD, &sock->flags)) { | |
1da177e4 | 2748 | /* Copy credentials */ |
7cc05662 | 2749 | scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); |
37a9a8df | 2750 | unix_set_secdata(&scm, skb); |
2b514574 | 2751 | check_creds = true; |
1da177e4 LT |
2752 | } |
2753 | ||
2754 | /* Copy address just once */ | |
2b514574 HFS |
2755 | if (state->msg && state->msg->msg_name) { |
2756 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, | |
2757 | state->msg->msg_name); | |
2758 | unix_copy_addr(state->msg, skb->sk); | |
859051dd DDM |
2759 | |
2760 | BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, | |
2761 | state->msg->msg_name, | |
2762 | &state->msg->msg_namelen); | |
2763 | ||
1da177e4 LT |
2764 | sunaddr = NULL; |
2765 | } | |
2766 | ||
e370a723 | 2767 | chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size); |
73ed5d25 | 2768 | skb_get(skb); |
2b514574 | 2769 | chunk = state->recv_actor(skb, skip, chunk, state); |
73ed5d25 HFS |
2770 | drop_skb = !unix_skb_len(skb); |
2771 | /* skb is only safe to use if !drop_skb */ | |
2772 | consume_skb(skb); | |
2b514574 | 2773 | if (chunk < 0) { |
1da177e4 LT |
2774 | if (copied == 0) |
2775 | copied = -EFAULT; | |
2776 | break; | |
2777 | } | |
2778 | copied += chunk; | |
2779 | size -= chunk; | |
2780 | ||
73ed5d25 HFS |
2781 | if (drop_skb) { |
2782 | /* the skb was touched by a concurrent reader; | |
2783 | * we should not expect anything from this skb | |
2784 | * anymore and assume it invalid - we can be | |
2785 | * sure it was dropped from the socket queue | |
2786 | * | |
2787 | * let's report a short read | |
2788 | */ | |
2789 | err = 0; | |
2790 | break; | |
2791 | } | |
2792 | ||
1da177e4 | 2793 | /* Mark read part of skb as used */ |
6eba6a37 | 2794 | if (!(flags & MSG_PEEK)) { |
e370a723 | 2795 | UNIXCB(skb).consumed += chunk; |
1da177e4 | 2796 | |
fc0d7536 PE |
2797 | sk_peek_offset_bwd(sk, chunk); |
2798 | ||
3c32da19 | 2799 | if (UNIXCB(skb).fp) { |
3c32da19 | 2800 | scm_stat_del(sk, skb); |
7cc05662 | 2801 | unix_detach_fds(&scm, skb); |
3c32da19 | 2802 | } |
1da177e4 | 2803 | |
e370a723 | 2804 | if (unix_skb_len(skb)) |
1da177e4 | 2805 | break; |
1da177e4 | 2806 | |
6f01fd6e | 2807 | skb_unlink(skb, &sk->sk_receive_queue); |
70d4bf6d | 2808 | consume_skb(skb); |
1da177e4 | 2809 | |
7cc05662 | 2810 | if (scm.fp) |
1da177e4 | 2811 | break; |
6eba6a37 | 2812 | } else { |
1da177e4 LT |
2813 | /* It is questionable, see note in unix_dgram_recvmsg. |
2814 | */ | |
2815 | if (UNIXCB(skb).fp) | |
cbcf0112 | 2816 | unix_peek_fds(&scm, skb); |
1da177e4 | 2817 | |
e9193d60 | 2818 | sk_peek_offset_fwd(sk, chunk); |
fc0d7536 | 2819 | |
9f389e35 AC |
2820 | if (UNIXCB(skb).fp) |
2821 | break; | |
2822 | ||
e9193d60 | 2823 | skip = 0; |
9f389e35 AC |
2824 | last = skb; |
2825 | last_len = skb->len; | |
2826 | unix_state_lock(sk); | |
2827 | skb = skb_peek_next(skb, &sk->sk_receive_queue); | |
2828 | if (skb) | |
2829 | goto again; | |
2830 | unix_state_unlock(sk); | |
1da177e4 LT |
2831 | break; |
2832 | } | |
2833 | } while (size); | |
2834 | ||
6e1ce3c3 | 2835 | mutex_unlock(&u->iolock); |
9d797ee2 | 2836 | if (state->msg) |
a9c49cc2 | 2837 | scm_recv_unix(sock, state->msg, &scm, flags); |
2b514574 HFS |
2838 | else |
2839 | scm_destroy(&scm); | |
1da177e4 LT |
2840 | out: |
2841 | return copied ? : err; | |
2842 | } | |
2843 | ||
2b514574 HFS |
2844 | static int unix_stream_read_actor(struct sk_buff *skb, |
2845 | int skip, int chunk, | |
2846 | struct unix_stream_read_state *state) | |
2847 | { | |
2848 | int ret; | |
2849 | ||
2850 | ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip, | |
2851 | state->msg, chunk); | |
2852 | return ret ?: chunk; | |
2853 | } | |
2854 | ||
94531cfc JW |
2855 | int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, |
2856 | size_t size, int flags) | |
2857 | { | |
2858 | struct unix_stream_read_state state = { | |
2859 | .recv_actor = unix_stream_read_actor, | |
2860 | .socket = sk->sk_socket, | |
2861 | .msg = msg, | |
2862 | .size = size, | |
2863 | .flags = flags | |
2864 | }; | |
2865 | ||
2866 | return unix_stream_read_generic(&state, true); | |
2867 | } | |
2868 | ||
2b514574 HFS |
2869 | static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, |
2870 | size_t size, int flags) | |
2871 | { | |
2872 | struct unix_stream_read_state state = { | |
2873 | .recv_actor = unix_stream_read_actor, | |
2874 | .socket = sock, | |
2875 | .msg = msg, | |
2876 | .size = size, | |
2877 | .flags = flags | |
2878 | }; | |
2879 | ||
94531cfc JW |
2880 | #ifdef CONFIG_BPF_SYSCALL |
2881 | struct sock *sk = sock->sk; | |
2882 | const struct proto *prot = READ_ONCE(sk->sk_prot); | |
2883 | ||
2884 | if (prot != &unix_stream_proto) | |
ec095263 | 2885 | return prot->recvmsg(sk, msg, size, flags, NULL); |
94531cfc | 2886 | #endif |
06a77b07 | 2887 | return unix_stream_read_generic(&state, true); |
2b514574 HFS |
2888 | } |
2889 | ||
2b514574 HFS |
2890 | static int unix_stream_splice_actor(struct sk_buff *skb, |
2891 | int skip, int chunk, | |
2892 | struct unix_stream_read_state *state) | |
2893 | { | |
2894 | return skb_splice_bits(skb, state->socket->sk, | |
2895 | UNIXCB(skb).consumed + skip, | |
25869262 | 2896 | state->pipe, chunk, state->splice_flags); |
2b514574 HFS |
2897 | } |
2898 | ||
2899 | static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos, | |
2900 | struct pipe_inode_info *pipe, | |
2901 | size_t size, unsigned int flags) | |
2902 | { | |
2903 | struct unix_stream_read_state state = { | |
2904 | .recv_actor = unix_stream_splice_actor, | |
2905 | .socket = sock, | |
2906 | .pipe = pipe, | |
2907 | .size = size, | |
2908 | .splice_flags = flags, | |
2909 | }; | |
2910 | ||
2911 | if (unlikely(*ppos)) | |
2912 | return -ESPIPE; | |
2913 | ||
2914 | if (sock->file->f_flags & O_NONBLOCK || | |
2915 | flags & SPLICE_F_NONBLOCK) | |
2916 | state.flags = MSG_DONTWAIT; | |
2917 | ||
06a77b07 | 2918 | return unix_stream_read_generic(&state, false); |
2b514574 HFS |
2919 | } |
2920 | ||
1da177e4 LT |
2921 | static int unix_shutdown(struct socket *sock, int mode) |
2922 | { | |
2923 | struct sock *sk = sock->sk; | |
2924 | struct sock *other; | |
2925 | ||
fc61b928 XW |
2926 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
2927 | return -EINVAL; | |
2928 | /* This maps: | |
2929 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) | |
2930 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) | |
2931 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) | |
2932 | */ | |
2933 | ++mode; | |
7180a031 AC |
2934 | |
2935 | unix_state_lock(sk); | |
e1d09c2c | 2936 | WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | mode); |
7180a031 AC |
2937 | other = unix_peer(sk); |
2938 | if (other) | |
2939 | sock_hold(other); | |
2940 | unix_state_unlock(sk); | |
2941 | sk->sk_state_change(sk); | |
2942 | ||
2943 | if (other && | |
2944 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { | |
2945 | ||
2946 | int peer_mode = 0; | |
94531cfc | 2947 | const struct proto *prot = READ_ONCE(other->sk_prot); |
7180a031 | 2948 | |
d359902d JW |
2949 | if (prot->unhash) |
2950 | prot->unhash(other); | |
7180a031 AC |
2951 | if (mode&RCV_SHUTDOWN) |
2952 | peer_mode |= SEND_SHUTDOWN; | |
2953 | if (mode&SEND_SHUTDOWN) | |
2954 | peer_mode |= RCV_SHUTDOWN; | |
2955 | unix_state_lock(other); | |
e1d09c2c | 2956 | WRITE_ONCE(other->sk_shutdown, other->sk_shutdown | peer_mode); |
7180a031 AC |
2957 | unix_state_unlock(other); |
2958 | other->sk_state_change(other); | |
d0c6416b | 2959 | if (peer_mode == SHUTDOWN_MASK) |
7180a031 | 2960 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); |
d0c6416b | 2961 | else if (peer_mode & RCV_SHUTDOWN) |
7180a031 | 2962 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); |
1da177e4 | 2963 | } |
7180a031 AC |
2964 | if (other) |
2965 | sock_put(other); | |
2966 | ||
1da177e4 LT |
2967 | return 0; |
2968 | } | |
2969 | ||
885ee74d PE |
2970 | long unix_inq_len(struct sock *sk) |
2971 | { | |
2972 | struct sk_buff *skb; | |
2973 | long amount = 0; | |
2974 | ||
2975 | if (sk->sk_state == TCP_LISTEN) | |
2976 | return -EINVAL; | |
2977 | ||
2978 | spin_lock(&sk->sk_receive_queue.lock); | |
2979 | if (sk->sk_type == SOCK_STREAM || | |
2980 | sk->sk_type == SOCK_SEQPACKET) { | |
2981 | skb_queue_walk(&sk->sk_receive_queue, skb) | |
e370a723 | 2982 | amount += unix_skb_len(skb); |
885ee74d PE |
2983 | } else { |
2984 | skb = skb_peek(&sk->sk_receive_queue); | |
2985 | if (skb) | |
2986 | amount = skb->len; | |
2987 | } | |
2988 | spin_unlock(&sk->sk_receive_queue.lock); | |
2989 | ||
2990 | return amount; | |
2991 | } | |
2992 | EXPORT_SYMBOL_GPL(unix_inq_len); | |
2993 | ||
2994 | long unix_outq_len(struct sock *sk) | |
2995 | { | |
2996 | return sk_wmem_alloc_get(sk); | |
2997 | } | |
2998 | EXPORT_SYMBOL_GPL(unix_outq_len); | |
2999 | ||
ba94f308 AV |
3000 | static int unix_open_file(struct sock *sk) |
3001 | { | |
3002 | struct path path; | |
3003 | struct file *f; | |
3004 | int fd; | |
3005 | ||
3006 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) | |
3007 | return -EPERM; | |
3008 | ||
ae3b5641 AV |
3009 | if (!smp_load_acquire(&unix_sk(sk)->addr)) |
3010 | return -ENOENT; | |
3011 | ||
ba94f308 | 3012 | path = unix_sk(sk)->path; |
ae3b5641 | 3013 | if (!path.dentry) |
ba94f308 | 3014 | return -ENOENT; |
ba94f308 AV |
3015 | |
3016 | path_get(&path); | |
ba94f308 AV |
3017 | |
3018 | fd = get_unused_fd_flags(O_CLOEXEC); | |
3019 | if (fd < 0) | |
3020 | goto out; | |
3021 | ||
3022 | f = dentry_open(&path, O_PATH, current_cred()); | |
3023 | if (IS_ERR(f)) { | |
3024 | put_unused_fd(fd); | |
3025 | fd = PTR_ERR(f); | |
3026 | goto out; | |
3027 | } | |
3028 | ||
3029 | fd_install(fd, f); | |
3030 | out: | |
3031 | path_put(&path); | |
3032 | ||
3033 | return fd; | |
3034 | } | |
3035 | ||
1da177e4 LT |
3036 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
3037 | { | |
3038 | struct sock *sk = sock->sk; | |
e27dfcea | 3039 | long amount = 0; |
1da177e4 LT |
3040 | int err; |
3041 | ||
6eba6a37 ED |
3042 | switch (cmd) { |
3043 | case SIOCOUTQ: | |
885ee74d | 3044 | amount = unix_outq_len(sk); |
6eba6a37 ED |
3045 | err = put_user(amount, (int __user *)arg); |
3046 | break; | |
3047 | case SIOCINQ: | |
885ee74d PE |
3048 | amount = unix_inq_len(sk); |
3049 | if (amount < 0) | |
3050 | err = amount; | |
3051 | else | |
1da177e4 | 3052 | err = put_user(amount, (int __user *)arg); |
885ee74d | 3053 | break; |
ba94f308 AV |
3054 | case SIOCUNIXFILE: |
3055 | err = unix_open_file(sk); | |
3056 | break; | |
314001f0 RS |
3057 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
3058 | case SIOCATMARK: | |
3059 | { | |
3060 | struct sk_buff *skb; | |
314001f0 RS |
3061 | int answ = 0; |
3062 | ||
3063 | skb = skb_peek(&sk->sk_receive_queue); | |
e82025c6 | 3064 | if (skb && skb == READ_ONCE(unix_sk(sk)->oob_skb)) |
314001f0 RS |
3065 | answ = 1; |
3066 | err = put_user(answ, (int __user *)arg); | |
3067 | } | |
3068 | break; | |
3069 | #endif | |
6eba6a37 ED |
3070 | default: |
3071 | err = -ENOIOCTLCMD; | |
3072 | break; | |
1da177e4 LT |
3073 | } |
3074 | return err; | |
3075 | } | |
3076 | ||
5f6beb9e AB |
3077 | #ifdef CONFIG_COMPAT |
3078 | static int unix_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
3079 | { | |
3080 | return unix_ioctl(sock, cmd, (unsigned long)compat_ptr(arg)); | |
3081 | } | |
3082 | #endif | |
3083 | ||
a11e1d43 | 3084 | static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
1da177e4 LT |
3085 | { |
3086 | struct sock *sk = sock->sk; | |
a11e1d43 | 3087 | __poll_t mask; |
e1d09c2c | 3088 | u8 shutdown; |
a11e1d43 | 3089 | |
89ab066d | 3090 | sock_poll_wait(file, sock, wait); |
a11e1d43 | 3091 | mask = 0; |
e1d09c2c | 3092 | shutdown = READ_ONCE(sk->sk_shutdown); |
1da177e4 LT |
3093 | |
3094 | /* exceptional events? */ | |
cc04410a | 3095 | if (READ_ONCE(sk->sk_err)) |
a9a08845 | 3096 | mask |= EPOLLERR; |
e1d09c2c | 3097 | if (shutdown == SHUTDOWN_MASK) |
a9a08845 | 3098 | mask |= EPOLLHUP; |
e1d09c2c | 3099 | if (shutdown & RCV_SHUTDOWN) |
a9a08845 | 3100 | mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM; |
1da177e4 LT |
3101 | |
3102 | /* readable? */ | |
3ef7cf57 | 3103 | if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) |
a9a08845 | 3104 | mask |= EPOLLIN | EPOLLRDNORM; |
af493388 CW |
3105 | if (sk_is_readable(sk)) |
3106 | mask |= EPOLLIN | EPOLLRDNORM; | |
d9a232d4 KI |
3107 | #if IS_ENABLED(CONFIG_AF_UNIX_OOB) |
3108 | if (READ_ONCE(unix_sk(sk)->oob_skb)) | |
3109 | mask |= EPOLLPRI; | |
3110 | #endif | |
1da177e4 LT |
3111 | |
3112 | /* Connection-based need to check for termination and startup */ | |
6eba6a37 ED |
3113 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
3114 | sk->sk_state == TCP_CLOSE) | |
a9a08845 | 3115 | mask |= EPOLLHUP; |
1da177e4 LT |
3116 | |
3117 | /* | |
3118 | * we set writable also when the other side has shut down the | |
3119 | * connection. This prevents stuck sockets. | |
3120 | */ | |
3121 | if (unix_writable(sk)) | |
a9a08845 | 3122 | mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; |
1da177e4 LT |
3123 | |
3124 | return mask; | |
3125 | } | |
3126 | ||
a11e1d43 LT |
3127 | static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, |
3128 | poll_table *wait) | |
3c73419c | 3129 | { |
ec0d215f | 3130 | struct sock *sk = sock->sk, *other; |
a11e1d43 LT |
3131 | unsigned int writable; |
3132 | __poll_t mask; | |
e1d09c2c | 3133 | u8 shutdown; |
a11e1d43 | 3134 | |
89ab066d | 3135 | sock_poll_wait(file, sock, wait); |
a11e1d43 | 3136 | mask = 0; |
e1d09c2c | 3137 | shutdown = READ_ONCE(sk->sk_shutdown); |
3c73419c RW |
3138 | |
3139 | /* exceptional events? */ | |
cc04410a ED |
3140 | if (READ_ONCE(sk->sk_err) || |
3141 | !skb_queue_empty_lockless(&sk->sk_error_queue)) | |
a9a08845 LT |
3142 | mask |= EPOLLERR | |
3143 | (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0); | |
7d4c04fc | 3144 | |
e1d09c2c | 3145 | if (shutdown & RCV_SHUTDOWN) |
a9a08845 | 3146 | mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM; |
e1d09c2c | 3147 | if (shutdown == SHUTDOWN_MASK) |
a9a08845 | 3148 | mask |= EPOLLHUP; |
3c73419c RW |
3149 | |
3150 | /* readable? */ | |
3ef7cf57 | 3151 | if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) |
a9a08845 | 3152 | mask |= EPOLLIN | EPOLLRDNORM; |
af493388 CW |
3153 | if (sk_is_readable(sk)) |
3154 | mask |= EPOLLIN | EPOLLRDNORM; | |
3c73419c RW |
3155 | |
3156 | /* Connection-based need to check for termination and startup */ | |
3157 | if (sk->sk_type == SOCK_SEQPACKET) { | |
3158 | if (sk->sk_state == TCP_CLOSE) | |
a9a08845 | 3159 | mask |= EPOLLHUP; |
3c73419c RW |
3160 | /* connection hasn't started yet? */ |
3161 | if (sk->sk_state == TCP_SYN_SENT) | |
3162 | return mask; | |
3163 | } | |
3164 | ||
973a34aa | 3165 | /* No write status requested, avoid expensive OUT tests. */ |
a11e1d43 | 3166 | if (!(poll_requested_events(wait) & (EPOLLWRBAND|EPOLLWRNORM|EPOLLOUT))) |
973a34aa ED |
3167 | return mask; |
3168 | ||
ec0d215f | 3169 | writable = unix_writable(sk); |
7d267278 RW |
3170 | if (writable) { |
3171 | unix_state_lock(sk); | |
3172 | ||
3173 | other = unix_peer(sk); | |
3174 | if (other && unix_peer(other) != sk && | |
04f08eb4 | 3175 | unix_recvq_full_lockless(other) && |
7d267278 RW |
3176 | unix_dgram_peer_wake_me(sk, other)) |
3177 | writable = 0; | |
3178 | ||
3179 | unix_state_unlock(sk); | |
ec0d215f RW |
3180 | } |
3181 | ||
3182 | if (writable) | |
a9a08845 | 3183 | mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; |
3c73419c | 3184 | else |
9cd3e072 | 3185 | sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
3c73419c | 3186 | |
3c73419c RW |
3187 | return mask; |
3188 | } | |
1da177e4 LT |
3189 | |
3190 | #ifdef CONFIG_PROC_FS | |
a53eb3fe | 3191 | |
7123aaa3 ED |
3192 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
3193 | ||
3194 | #define get_bucket(x) ((x) >> BUCKET_SPACE) | |
afd20b92 | 3195 | #define get_offset(x) ((x) & ((1UL << BUCKET_SPACE) - 1)) |
7123aaa3 | 3196 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) |
a53eb3fe | 3197 | |
7123aaa3 | 3198 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
1da177e4 | 3199 | { |
7123aaa3 ED |
3200 | unsigned long offset = get_offset(*pos); |
3201 | unsigned long bucket = get_bucket(*pos); | |
7123aaa3 | 3202 | unsigned long count = 0; |
cf2f225e | 3203 | struct sock *sk; |
1da177e4 | 3204 | |
cf2f225e KI |
3205 | for (sk = sk_head(&seq_file_net(seq)->unx.table.buckets[bucket]); |
3206 | sk; sk = sk_next(sk)) { | |
7123aaa3 ED |
3207 | if (++count == offset) |
3208 | break; | |
3209 | } | |
3210 | ||
3211 | return sk; | |
3212 | } | |
3213 | ||
4408d55a | 3214 | static struct sock *unix_get_first(struct seq_file *seq, loff_t *pos) |
7123aaa3 | 3215 | { |
afd20b92 | 3216 | unsigned long bucket = get_bucket(*pos); |
79b05bea | 3217 | struct net *net = seq_file_net(seq); |
4408d55a | 3218 | struct sock *sk; |
7123aaa3 | 3219 | |
f302d180 | 3220 | while (bucket < UNIX_HASH_SIZE) { |
79b05bea | 3221 | spin_lock(&net->unx.table.locks[bucket]); |
4408d55a | 3222 | |
7123aaa3 ED |
3223 | sk = unix_from_bucket(seq, pos); |
3224 | if (sk) | |
3225 | return sk; | |
3226 | ||
79b05bea | 3227 | spin_unlock(&net->unx.table.locks[bucket]); |
4408d55a KI |
3228 | |
3229 | *pos = set_bucket_offset(++bucket, 1); | |
3230 | } | |
7123aaa3 | 3231 | |
1da177e4 LT |
3232 | return NULL; |
3233 | } | |
3234 | ||
4408d55a KI |
3235 | static struct sock *unix_get_next(struct seq_file *seq, struct sock *sk, |
3236 | loff_t *pos) | |
3237 | { | |
3238 | unsigned long bucket = get_bucket(*pos); | |
3239 | ||
cf2f225e KI |
3240 | sk = sk_next(sk); |
3241 | if (sk) | |
3242 | return sk; | |
3243 | ||
4408d55a | 3244 | |
cf2f225e | 3245 | spin_unlock(&seq_file_net(seq)->unx.table.locks[bucket]); |
4408d55a KI |
3246 | |
3247 | *pos = set_bucket_offset(++bucket, 1); | |
3248 | ||
3249 | return unix_get_first(seq, pos); | |
3250 | } | |
3251 | ||
1da177e4 LT |
3252 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
3253 | { | |
7123aaa3 ED |
3254 | if (!*pos) |
3255 | return SEQ_START_TOKEN; | |
3256 | ||
4408d55a | 3257 | return unix_get_first(seq, pos); |
1da177e4 LT |
3258 | } |
3259 | ||
3260 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
3261 | { | |
3262 | ++*pos; | |
4408d55a KI |
3263 | |
3264 | if (v == SEQ_START_TOKEN) | |
3265 | return unix_get_first(seq, pos); | |
3266 | ||
3267 | return unix_get_next(seq, v, pos); | |
1da177e4 LT |
3268 | } |
3269 | ||
3270 | static void unix_seq_stop(struct seq_file *seq, void *v) | |
3271 | { | |
afd20b92 KI |
3272 | struct sock *sk = v; |
3273 | ||
2f7ca90a | 3274 | if (sk) |
79b05bea | 3275 | spin_unlock(&seq_file_net(seq)->unx.table.locks[sk->sk_hash]); |
1da177e4 LT |
3276 | } |
3277 | ||
3278 | static int unix_seq_show(struct seq_file *seq, void *v) | |
3279 | { | |
ac7bfa62 | 3280 | |
b9f3124f | 3281 | if (v == SEQ_START_TOKEN) |
1da177e4 LT |
3282 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
3283 | "Inode Path\n"); | |
3284 | else { | |
3285 | struct sock *s = v; | |
3286 | struct unix_sock *u = unix_sk(s); | |
1c92b4e5 | 3287 | unix_state_lock(s); |
1da177e4 | 3288 | |
71338aa7 | 3289 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
1da177e4 | 3290 | s, |
41c6d650 | 3291 | refcount_read(&s->sk_refcnt), |
1da177e4 LT |
3292 | 0, |
3293 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, | |
3294 | s->sk_type, | |
3295 | s->sk_socket ? | |
3296 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : | |
3297 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), | |
3298 | sock_i_ino(s)); | |
3299 | ||
2f7ca90a | 3300 | if (u->addr) { // under a hash table lock here |
1da177e4 LT |
3301 | int i, len; |
3302 | seq_putc(seq, ' '); | |
3303 | ||
3304 | i = 0; | |
755662ce KI |
3305 | len = u->addr->len - |
3306 | offsetof(struct sockaddr_un, sun_path); | |
5ce7ab49 | 3307 | if (u->addr->name->sun_path[0]) { |
1da177e4 | 3308 | len--; |
5ce7ab49 | 3309 | } else { |
1da177e4 LT |
3310 | seq_putc(seq, '@'); |
3311 | i++; | |
3312 | } | |
3313 | for ( ; i < len; i++) | |
e7947ea7 IB |
3314 | seq_putc(seq, u->addr->name->sun_path[i] ?: |
3315 | '@'); | |
1da177e4 | 3316 | } |
1c92b4e5 | 3317 | unix_state_unlock(s); |
1da177e4 LT |
3318 | seq_putc(seq, '\n'); |
3319 | } | |
3320 | ||
3321 | return 0; | |
3322 | } | |
3323 | ||
56b3d975 | 3324 | static const struct seq_operations unix_seq_ops = { |
1da177e4 LT |
3325 | .start = unix_seq_start, |
3326 | .next = unix_seq_next, | |
3327 | .stop = unix_seq_stop, | |
3328 | .show = unix_seq_show, | |
3329 | }; | |
2c860a43 | 3330 | |
3a04927f | 3331 | #ifdef CONFIG_BPF_SYSCALL |
855d8e77 KI |
3332 | struct bpf_unix_iter_state { |
3333 | struct seq_net_private p; | |
3334 | unsigned int cur_sk; | |
3335 | unsigned int end_sk; | |
3336 | unsigned int max_sk; | |
3337 | struct sock **batch; | |
3338 | bool st_bucket_done; | |
3339 | }; | |
3340 | ||
2c860a43 KI |
3341 | struct bpf_iter__unix { |
3342 | __bpf_md_ptr(struct bpf_iter_meta *, meta); | |
3343 | __bpf_md_ptr(struct unix_sock *, unix_sk); | |
3344 | uid_t uid __aligned(8); | |
3345 | }; | |
3346 | ||
3347 | static int unix_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, | |
3348 | struct unix_sock *unix_sk, uid_t uid) | |
3349 | { | |
3350 | struct bpf_iter__unix ctx; | |
3351 | ||
3352 | meta->seq_num--; /* skip SEQ_START_TOKEN */ | |
3353 | ctx.meta = meta; | |
3354 | ctx.unix_sk = unix_sk; | |
3355 | ctx.uid = uid; | |
3356 | return bpf_iter_run_prog(prog, &ctx); | |
3357 | } | |
3358 | ||
855d8e77 KI |
3359 | static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk) |
3360 | ||
3361 | { | |
3362 | struct bpf_unix_iter_state *iter = seq->private; | |
3363 | unsigned int expected = 1; | |
3364 | struct sock *sk; | |
3365 | ||
3366 | sock_hold(start_sk); | |
3367 | iter->batch[iter->end_sk++] = start_sk; | |
3368 | ||
3369 | for (sk = sk_next(start_sk); sk; sk = sk_next(sk)) { | |
855d8e77 KI |
3370 | if (iter->end_sk < iter->max_sk) { |
3371 | sock_hold(sk); | |
3372 | iter->batch[iter->end_sk++] = sk; | |
3373 | } | |
3374 | ||
3375 | expected++; | |
3376 | } | |
3377 | ||
cf2f225e | 3378 | spin_unlock(&seq_file_net(seq)->unx.table.locks[start_sk->sk_hash]); |
855d8e77 KI |
3379 | |
3380 | return expected; | |
3381 | } | |
3382 | ||
3383 | static void bpf_iter_unix_put_batch(struct bpf_unix_iter_state *iter) | |
3384 | { | |
3385 | while (iter->cur_sk < iter->end_sk) | |
3386 | sock_put(iter->batch[iter->cur_sk++]); | |
3387 | } | |
3388 | ||
3389 | static int bpf_iter_unix_realloc_batch(struct bpf_unix_iter_state *iter, | |
3390 | unsigned int new_batch_sz) | |
3391 | { | |
3392 | struct sock **new_batch; | |
3393 | ||
3394 | new_batch = kvmalloc(sizeof(*new_batch) * new_batch_sz, | |
3395 | GFP_USER | __GFP_NOWARN); | |
3396 | if (!new_batch) | |
3397 | return -ENOMEM; | |
3398 | ||
3399 | bpf_iter_unix_put_batch(iter); | |
3400 | kvfree(iter->batch); | |
3401 | iter->batch = new_batch; | |
3402 | iter->max_sk = new_batch_sz; | |
3403 | ||
3404 | return 0; | |
3405 | } | |
3406 | ||
3407 | static struct sock *bpf_iter_unix_batch(struct seq_file *seq, | |
3408 | loff_t *pos) | |
3409 | { | |
3410 | struct bpf_unix_iter_state *iter = seq->private; | |
3411 | unsigned int expected; | |
3412 | bool resized = false; | |
3413 | struct sock *sk; | |
3414 | ||
3415 | if (iter->st_bucket_done) | |
3416 | *pos = set_bucket_offset(get_bucket(*pos) + 1, 1); | |
3417 | ||
3418 | again: | |
3419 | /* Get a new batch */ | |
3420 | iter->cur_sk = 0; | |
3421 | iter->end_sk = 0; | |
3422 | ||
3423 | sk = unix_get_first(seq, pos); | |
3424 | if (!sk) | |
3425 | return NULL; /* Done */ | |
3426 | ||
3427 | expected = bpf_iter_unix_hold_batch(seq, sk); | |
3428 | ||
3429 | if (iter->end_sk == expected) { | |
3430 | iter->st_bucket_done = true; | |
3431 | return sk; | |
3432 | } | |
3433 | ||
3434 | if (!resized && !bpf_iter_unix_realloc_batch(iter, expected * 3 / 2)) { | |
3435 | resized = true; | |
3436 | goto again; | |
3437 | } | |
3438 | ||
3439 | return sk; | |
3440 | } | |
3441 | ||
3442 | static void *bpf_iter_unix_seq_start(struct seq_file *seq, loff_t *pos) | |
3443 | { | |
3444 | if (!*pos) | |
3445 | return SEQ_START_TOKEN; | |
3446 | ||
3447 | /* bpf iter does not support lseek, so it always | |
3448 | * continue from where it was stop()-ped. | |
3449 | */ | |
3450 | return bpf_iter_unix_batch(seq, pos); | |
3451 | } | |
3452 | ||
3453 | static void *bpf_iter_unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
3454 | { | |
3455 | struct bpf_unix_iter_state *iter = seq->private; | |
3456 | struct sock *sk; | |
3457 | ||
3458 | /* Whenever seq_next() is called, the iter->cur_sk is | |
3459 | * done with seq_show(), so advance to the next sk in | |
3460 | * the batch. | |
3461 | */ | |
3462 | if (iter->cur_sk < iter->end_sk) | |
3463 | sock_put(iter->batch[iter->cur_sk++]); | |
3464 | ||
3465 | ++*pos; | |
3466 | ||
3467 | if (iter->cur_sk < iter->end_sk) | |
3468 | sk = iter->batch[iter->cur_sk]; | |
3469 | else | |
3470 | sk = bpf_iter_unix_batch(seq, pos); | |
3471 | ||
3472 | return sk; | |
3473 | } | |
3474 | ||
2c860a43 KI |
3475 | static int bpf_iter_unix_seq_show(struct seq_file *seq, void *v) |
3476 | { | |
3477 | struct bpf_iter_meta meta; | |
3478 | struct bpf_prog *prog; | |
3479 | struct sock *sk = v; | |
3480 | uid_t uid; | |
855d8e77 KI |
3481 | bool slow; |
3482 | int ret; | |
2c860a43 KI |
3483 | |
3484 | if (v == SEQ_START_TOKEN) | |
3485 | return 0; | |
3486 | ||
855d8e77 KI |
3487 | slow = lock_sock_fast(sk); |
3488 | ||
3489 | if (unlikely(sk_unhashed(sk))) { | |
3490 | ret = SEQ_SKIP; | |
3491 | goto unlock; | |
3492 | } | |
3493 | ||
2c860a43 KI |
3494 | uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); |
3495 | meta.seq = seq; | |
3496 | prog = bpf_iter_get_info(&meta, false); | |
855d8e77 KI |
3497 | ret = unix_prog_seq_show(prog, &meta, v, uid); |
3498 | unlock: | |
3499 | unlock_sock_fast(sk, slow); | |
3500 | return ret; | |
2c860a43 KI |
3501 | } |
3502 | ||
3503 | static void bpf_iter_unix_seq_stop(struct seq_file *seq, void *v) | |
3504 | { | |
855d8e77 | 3505 | struct bpf_unix_iter_state *iter = seq->private; |
2c860a43 KI |
3506 | struct bpf_iter_meta meta; |
3507 | struct bpf_prog *prog; | |
3508 | ||
3509 | if (!v) { | |
3510 | meta.seq = seq; | |
3511 | prog = bpf_iter_get_info(&meta, true); | |
3512 | if (prog) | |
3513 | (void)unix_prog_seq_show(prog, &meta, v, 0); | |
3514 | } | |
3515 | ||
855d8e77 KI |
3516 | if (iter->cur_sk < iter->end_sk) |
3517 | bpf_iter_unix_put_batch(iter); | |
2c860a43 KI |
3518 | } |
3519 | ||
3520 | static const struct seq_operations bpf_iter_unix_seq_ops = { | |
855d8e77 KI |
3521 | .start = bpf_iter_unix_seq_start, |
3522 | .next = bpf_iter_unix_seq_next, | |
2c860a43 KI |
3523 | .stop = bpf_iter_unix_seq_stop, |
3524 | .show = bpf_iter_unix_seq_show, | |
3525 | }; | |
3526 | #endif | |
1da177e4 LT |
3527 | #endif |
3528 | ||
ec1b4cf7 | 3529 | static const struct net_proto_family unix_family_ops = { |
1da177e4 LT |
3530 | .family = PF_UNIX, |
3531 | .create = unix_create, | |
3532 | .owner = THIS_MODULE, | |
3533 | }; | |
3534 | ||
097e66c5 | 3535 | |
2c8c1e72 | 3536 | static int __net_init unix_net_init(struct net *net) |
097e66c5 | 3537 | { |
b6e81138 | 3538 | int i; |
097e66c5 | 3539 | |
a0a53c8b | 3540 | net->unx.sysctl_max_dgram_qlen = 10; |
1597fbc0 PE |
3541 | if (unix_sysctl_register(net)) |
3542 | goto out; | |
d392e497 | 3543 | |
097e66c5 | 3544 | #ifdef CONFIG_PROC_FS |
c3506372 | 3545 | if (!proc_create_net("unix", 0, net->proc_net, &unix_seq_ops, |
b6e81138 KI |
3546 | sizeof(struct seq_net_private))) |
3547 | goto err_sysctl; | |
3548 | #endif | |
3549 | ||
3550 | net->unx.table.locks = kvmalloc_array(UNIX_HASH_SIZE, | |
3551 | sizeof(spinlock_t), GFP_KERNEL); | |
3552 | if (!net->unx.table.locks) | |
3553 | goto err_proc; | |
3554 | ||
3555 | net->unx.table.buckets = kvmalloc_array(UNIX_HASH_SIZE, | |
3556 | sizeof(struct hlist_head), | |
3557 | GFP_KERNEL); | |
3558 | if (!net->unx.table.buckets) | |
3559 | goto free_locks; | |
3560 | ||
3561 | for (i = 0; i < UNIX_HASH_SIZE; i++) { | |
3562 | spin_lock_init(&net->unx.table.locks[i]); | |
3563 | INIT_HLIST_HEAD(&net->unx.table.buckets[i]); | |
1597fbc0 | 3564 | } |
b6e81138 KI |
3565 | |
3566 | return 0; | |
3567 | ||
3568 | free_locks: | |
3569 | kvfree(net->unx.table.locks); | |
3570 | err_proc: | |
3571 | #ifdef CONFIG_PROC_FS | |
3572 | remove_proc_entry("unix", net->proc_net); | |
3573 | err_sysctl: | |
097e66c5 | 3574 | #endif |
b6e81138 | 3575 | unix_sysctl_unregister(net); |
097e66c5 | 3576 | out: |
b6e81138 | 3577 | return -ENOMEM; |
097e66c5 DL |
3578 | } |
3579 | ||
2c8c1e72 | 3580 | static void __net_exit unix_net_exit(struct net *net) |
097e66c5 | 3581 | { |
b6e81138 KI |
3582 | kvfree(net->unx.table.buckets); |
3583 | kvfree(net->unx.table.locks); | |
1597fbc0 | 3584 | unix_sysctl_unregister(net); |
ece31ffd | 3585 | remove_proc_entry("unix", net->proc_net); |
097e66c5 DL |
3586 | } |
3587 | ||
3588 | static struct pernet_operations unix_net_ops = { | |
3589 | .init = unix_net_init, | |
3590 | .exit = unix_net_exit, | |
3591 | }; | |
3592 | ||
3a04927f | 3593 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2c860a43 KI |
3594 | DEFINE_BPF_ITER_FUNC(unix, struct bpf_iter_meta *meta, |
3595 | struct unix_sock *unix_sk, uid_t uid) | |
3596 | ||
855d8e77 KI |
3597 | #define INIT_BATCH_SZ 16 |
3598 | ||
3599 | static int bpf_iter_init_unix(void *priv_data, struct bpf_iter_aux_info *aux) | |
3600 | { | |
3601 | struct bpf_unix_iter_state *iter = priv_data; | |
3602 | int err; | |
3603 | ||
3604 | err = bpf_iter_init_seq_net(priv_data, aux); | |
3605 | if (err) | |
3606 | return err; | |
3607 | ||
3608 | err = bpf_iter_unix_realloc_batch(iter, INIT_BATCH_SZ); | |
3609 | if (err) { | |
3610 | bpf_iter_fini_seq_net(priv_data); | |
3611 | return err; | |
3612 | } | |
3613 | ||
3614 | return 0; | |
3615 | } | |
3616 | ||
3617 | static void bpf_iter_fini_unix(void *priv_data) | |
3618 | { | |
3619 | struct bpf_unix_iter_state *iter = priv_data; | |
3620 | ||
3621 | bpf_iter_fini_seq_net(priv_data); | |
3622 | kvfree(iter->batch); | |
3623 | } | |
3624 | ||
2c860a43 KI |
3625 | static const struct bpf_iter_seq_info unix_seq_info = { |
3626 | .seq_ops = &bpf_iter_unix_seq_ops, | |
855d8e77 KI |
3627 | .init_seq_private = bpf_iter_init_unix, |
3628 | .fini_seq_private = bpf_iter_fini_unix, | |
3629 | .seq_priv_size = sizeof(struct bpf_unix_iter_state), | |
2c860a43 KI |
3630 | }; |
3631 | ||
eb7d8f1d KI |
3632 | static const struct bpf_func_proto * |
3633 | bpf_iter_unix_get_func_proto(enum bpf_func_id func_id, | |
3634 | const struct bpf_prog *prog) | |
3635 | { | |
3636 | switch (func_id) { | |
3637 | case BPF_FUNC_setsockopt: | |
3638 | return &bpf_sk_setsockopt_proto; | |
3639 | case BPF_FUNC_getsockopt: | |
3640 | return &bpf_sk_getsockopt_proto; | |
3641 | default: | |
3642 | return NULL; | |
3643 | } | |
3644 | } | |
3645 | ||
2c860a43 KI |
3646 | static struct bpf_iter_reg unix_reg_info = { |
3647 | .target = "unix", | |
3648 | .ctx_arg_info_size = 1, | |
3649 | .ctx_arg_info = { | |
3650 | { offsetof(struct bpf_iter__unix, unix_sk), | |
3651 | PTR_TO_BTF_ID_OR_NULL }, | |
3652 | }, | |
eb7d8f1d | 3653 | .get_func_proto = bpf_iter_unix_get_func_proto, |
2c860a43 KI |
3654 | .seq_info = &unix_seq_info, |
3655 | }; | |
3656 | ||
3657 | static void __init bpf_iter_register(void) | |
3658 | { | |
3659 | unix_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UNIX]; | |
3660 | if (bpf_iter_reg_target(&unix_reg_info)) | |
3661 | pr_warn("Warning: could not register bpf iterator unix\n"); | |
3662 | } | |
3663 | #endif | |
3664 | ||
1da177e4 LT |
3665 | static int __init af_unix_init(void) |
3666 | { | |
51bae889 | 3667 | int i, rc = -1; |
1da177e4 | 3668 | |
c593642c | 3669 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb)); |
1da177e4 | 3670 | |
51bae889 KI |
3671 | for (i = 0; i < UNIX_HASH_SIZE / 2; i++) { |
3672 | spin_lock_init(&bsd_socket_locks[i]); | |
3673 | INIT_HLIST_HEAD(&bsd_socket_buckets[i]); | |
3674 | } | |
3675 | ||
94531cfc JW |
3676 | rc = proto_register(&unix_dgram_proto, 1); |
3677 | if (rc != 0) { | |
3678 | pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); | |
3679 | goto out; | |
3680 | } | |
3681 | ||
3682 | rc = proto_register(&unix_stream_proto, 1); | |
ac7bfa62 | 3683 | if (rc != 0) { |
5cc208be | 3684 | pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); |
73e341e0 | 3685 | proto_unregister(&unix_dgram_proto); |
1da177e4 LT |
3686 | goto out; |
3687 | } | |
3688 | ||
3689 | sock_register(&unix_family_ops); | |
097e66c5 | 3690 | register_pernet_subsys(&unix_net_ops); |
c6382918 | 3691 | unix_bpf_build_proto(); |
2c860a43 | 3692 | |
3a04927f | 3693 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2c860a43 KI |
3694 | bpf_iter_register(); |
3695 | #endif | |
3696 | ||
1da177e4 LT |
3697 | out: |
3698 | return rc; | |
3699 | } | |
3700 | ||
3a04927f | 3701 | /* Later than subsys_initcall() because we depend on stuff initialised there */ |
3d366960 | 3702 | fs_initcall(af_unix_init); |