| 1 | /* |
| 2 | * NET4: Implementation of BSD Unix domain sockets. |
| 3 | * |
| 4 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * Fixes: |
| 12 | * Linus Torvalds : Assorted bug cures. |
| 13 | * Niibe Yutaka : async I/O support. |
| 14 | * Carsten Paeth : PF_UNIX check, address fixes. |
| 15 | * Alan Cox : Limit size of allocated blocks. |
| 16 | * Alan Cox : Fixed the stupid socketpair bug. |
| 17 | * Alan Cox : BSD compatibility fine tuning. |
| 18 | * Alan Cox : Fixed a bug in connect when interrupted. |
| 19 | * Alan Cox : Sorted out a proper draft version of |
| 20 | * file descriptor passing hacked up from |
| 21 | * Mike Shaver's work. |
| 22 | * Marty Leisner : Fixes to fd passing |
| 23 | * Nick Nevin : recvmsg bugfix. |
| 24 | * Alan Cox : Started proper garbage collector |
| 25 | * Heiko EiBfeldt : Missing verify_area check |
| 26 | * Alan Cox : Started POSIXisms |
| 27 | * Andreas Schwab : Replace inode by dentry for proper |
| 28 | * reference counting |
| 29 | * Kirk Petersen : Made this a module |
| 30 | * Christoph Rohland : Elegant non-blocking accept/connect algorithm. |
| 31 | * Lots of bug fixes. |
| 32 | * Alexey Kuznetosv : Repaired (I hope) bugs introduces |
| 33 | * by above two patches. |
| 34 | * Andrea Arcangeli : If possible we block in connect(2) |
| 35 | * if the max backlog of the listen socket |
| 36 | * is been reached. This won't break |
| 37 | * old apps and it will avoid huge amount |
| 38 | * of socks hashed (this for unix_gc() |
| 39 | * performances reasons). |
| 40 | * Security fix that limits the max |
| 41 | * number of socks to 2*max_files and |
| 42 | * the number of skb queueable in the |
| 43 | * dgram receiver. |
| 44 | * Artur Skawina : Hash function optimizations |
| 45 | * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) |
| 46 | * Malcolm Beattie : Set peercred for socketpair |
| 47 | * Michal Ostrowski : Module initialization cleanup. |
| 48 | * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, |
| 49 | * the core infrastructure is doing that |
| 50 | * for all net proto families now (2.5.69+) |
| 51 | * |
| 52 | * |
| 53 | * Known differences from reference BSD that was tested: |
| 54 | * |
| 55 | * [TO FIX] |
| 56 | * ECONNREFUSED is not returned from one end of a connected() socket to the |
| 57 | * other the moment one end closes. |
| 58 | * fstat() doesn't return st_dev=0, and give the blksize as high water mark |
| 59 | * and a fake inode identifier (nor the BSD first socket fstat twice bug). |
| 60 | * [NOT TO FIX] |
| 61 | * accept() returns a path name even if the connecting socket has closed |
| 62 | * in the meantime (BSD loses the path and gives up). |
| 63 | * accept() returns 0 length path for an unbound connector. BSD returns 16 |
| 64 | * and a null first byte in the path (but not for gethost/peername - BSD bug ??) |
| 65 | * socketpair(...SOCK_RAW..) doesn't panic the kernel. |
| 66 | * BSD af_unix apparently has connect forgetting to block properly. |
| 67 | * (need to check this with the POSIX spec in detail) |
| 68 | * |
| 69 | * Differences from 2.0.0-11-... (ANK) |
| 70 | * Bug fixes and improvements. |
| 71 | * - client shutdown killed server socket. |
| 72 | * - removed all useless cli/sti pairs. |
| 73 | * |
| 74 | * Semantic changes/extensions. |
| 75 | * - generic control message passing. |
| 76 | * - SCM_CREDENTIALS control message. |
| 77 | * - "Abstract" (not FS based) socket bindings. |
| 78 | * Abstract names are sequences of bytes (not zero terminated) |
| 79 | * started by 0, so that this name space does not intersect |
| 80 | * with BSD names. |
| 81 | */ |
| 82 | |
| 83 | #include <linux/module.h> |
| 84 | #include <linux/kernel.h> |
| 85 | #include <linux/signal.h> |
| 86 | #include <linux/sched.h> |
| 87 | #include <linux/errno.h> |
| 88 | #include <linux/string.h> |
| 89 | #include <linux/stat.h> |
| 90 | #include <linux/dcache.h> |
| 91 | #include <linux/namei.h> |
| 92 | #include <linux/socket.h> |
| 93 | #include <linux/un.h> |
| 94 | #include <linux/fcntl.h> |
| 95 | #include <linux/termios.h> |
| 96 | #include <linux/sockios.h> |
| 97 | #include <linux/net.h> |
| 98 | #include <linux/in.h> |
| 99 | #include <linux/fs.h> |
| 100 | #include <linux/slab.h> |
| 101 | #include <asm/uaccess.h> |
| 102 | #include <linux/skbuff.h> |
| 103 | #include <linux/netdevice.h> |
| 104 | #include <net/net_namespace.h> |
| 105 | #include <net/sock.h> |
| 106 | #include <net/tcp_states.h> |
| 107 | #include <net/af_unix.h> |
| 108 | #include <linux/proc_fs.h> |
| 109 | #include <linux/seq_file.h> |
| 110 | #include <net/scm.h> |
| 111 | #include <linux/init.h> |
| 112 | #include <linux/poll.h> |
| 113 | #include <linux/rtnetlink.h> |
| 114 | #include <linux/mount.h> |
| 115 | #include <net/checksum.h> |
| 116 | #include <linux/security.h> |
| 117 | |
| 118 | struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; |
| 119 | EXPORT_SYMBOL_GPL(unix_socket_table); |
| 120 | DEFINE_SPINLOCK(unix_table_lock); |
| 121 | EXPORT_SYMBOL_GPL(unix_table_lock); |
| 122 | static atomic_long_t unix_nr_socks; |
| 123 | |
| 124 | |
| 125 | static struct hlist_head *unix_sockets_unbound(void *addr) |
| 126 | { |
| 127 | unsigned long hash = (unsigned long)addr; |
| 128 | |
| 129 | hash ^= hash >> 16; |
| 130 | hash ^= hash >> 8; |
| 131 | hash %= UNIX_HASH_SIZE; |
| 132 | return &unix_socket_table[UNIX_HASH_SIZE + hash]; |
| 133 | } |
| 134 | |
| 135 | #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash < UNIX_HASH_SIZE) |
| 136 | |
| 137 | #ifdef CONFIG_SECURITY_NETWORK |
| 138 | static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| 139 | { |
| 140 | memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
| 141 | } |
| 142 | |
| 143 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| 144 | { |
| 145 | scm->secid = *UNIXSID(skb); |
| 146 | } |
| 147 | #else |
| 148 | static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| 149 | { } |
| 150 | |
| 151 | static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| 152 | { } |
| 153 | #endif /* CONFIG_SECURITY_NETWORK */ |
| 154 | |
| 155 | /* |
| 156 | * SMP locking strategy: |
| 157 | * hash table is protected with spinlock unix_table_lock |
| 158 | * each socket state is protected by separate spin lock. |
| 159 | */ |
| 160 | |
| 161 | static inline unsigned int unix_hash_fold(__wsum n) |
| 162 | { |
| 163 | unsigned int hash = (__force unsigned int)n; |
| 164 | |
| 165 | hash ^= hash>>16; |
| 166 | hash ^= hash>>8; |
| 167 | return hash&(UNIX_HASH_SIZE-1); |
| 168 | } |
| 169 | |
| 170 | #define unix_peer(sk) (unix_sk(sk)->peer) |
| 171 | |
| 172 | static inline int unix_our_peer(struct sock *sk, struct sock *osk) |
| 173 | { |
| 174 | return unix_peer(osk) == sk; |
| 175 | } |
| 176 | |
| 177 | static inline int unix_may_send(struct sock *sk, struct sock *osk) |
| 178 | { |
| 179 | return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
| 180 | } |
| 181 | |
| 182 | static inline int unix_recvq_full(struct sock const *sk) |
| 183 | { |
| 184 | return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; |
| 185 | } |
| 186 | |
| 187 | struct sock *unix_peer_get(struct sock *s) |
| 188 | { |
| 189 | struct sock *peer; |
| 190 | |
| 191 | unix_state_lock(s); |
| 192 | peer = unix_peer(s); |
| 193 | if (peer) |
| 194 | sock_hold(peer); |
| 195 | unix_state_unlock(s); |
| 196 | return peer; |
| 197 | } |
| 198 | EXPORT_SYMBOL_GPL(unix_peer_get); |
| 199 | |
| 200 | static inline void unix_release_addr(struct unix_address *addr) |
| 201 | { |
| 202 | if (atomic_dec_and_test(&addr->refcnt)) |
| 203 | kfree(addr); |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * Check unix socket name: |
| 208 | * - should be not zero length. |
| 209 | * - if started by not zero, should be NULL terminated (FS object) |
| 210 | * - if started by zero, it is abstract name. |
| 211 | */ |
| 212 | |
| 213 | static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) |
| 214 | { |
| 215 | if (len <= sizeof(short) || len > sizeof(*sunaddr)) |
| 216 | return -EINVAL; |
| 217 | if (!sunaddr || sunaddr->sun_family != AF_UNIX) |
| 218 | return -EINVAL; |
| 219 | if (sunaddr->sun_path[0]) { |
| 220 | /* |
| 221 | * This may look like an off by one error but it is a bit more |
| 222 | * subtle. 108 is the longest valid AF_UNIX path for a binding. |
| 223 | * sun_path[108] doesn't as such exist. However in kernel space |
| 224 | * we are guaranteed that it is a valid memory location in our |
| 225 | * kernel address buffer. |
| 226 | */ |
| 227 | ((char *)sunaddr)[len] = 0; |
| 228 | len = strlen(sunaddr->sun_path)+1+sizeof(short); |
| 229 | return len; |
| 230 | } |
| 231 | |
| 232 | *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
| 233 | return len; |
| 234 | } |
| 235 | |
| 236 | static void __unix_remove_socket(struct sock *sk) |
| 237 | { |
| 238 | sk_del_node_init(sk); |
| 239 | } |
| 240 | |
| 241 | static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) |
| 242 | { |
| 243 | WARN_ON(!sk_unhashed(sk)); |
| 244 | sk_add_node(sk, list); |
| 245 | } |
| 246 | |
| 247 | static inline void unix_remove_socket(struct sock *sk) |
| 248 | { |
| 249 | spin_lock(&unix_table_lock); |
| 250 | __unix_remove_socket(sk); |
| 251 | spin_unlock(&unix_table_lock); |
| 252 | } |
| 253 | |
| 254 | static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) |
| 255 | { |
| 256 | spin_lock(&unix_table_lock); |
| 257 | __unix_insert_socket(list, sk); |
| 258 | spin_unlock(&unix_table_lock); |
| 259 | } |
| 260 | |
| 261 | static struct sock *__unix_find_socket_byname(struct net *net, |
| 262 | struct sockaddr_un *sunname, |
| 263 | int len, int type, unsigned int hash) |
| 264 | { |
| 265 | struct sock *s; |
| 266 | |
| 267 | sk_for_each(s, &unix_socket_table[hash ^ type]) { |
| 268 | struct unix_sock *u = unix_sk(s); |
| 269 | |
| 270 | if (!net_eq(sock_net(s), net)) |
| 271 | continue; |
| 272 | |
| 273 | if (u->addr->len == len && |
| 274 | !memcmp(u->addr->name, sunname, len)) |
| 275 | goto found; |
| 276 | } |
| 277 | s = NULL; |
| 278 | found: |
| 279 | return s; |
| 280 | } |
| 281 | |
| 282 | static inline struct sock *unix_find_socket_byname(struct net *net, |
| 283 | struct sockaddr_un *sunname, |
| 284 | int len, int type, |
| 285 | unsigned int hash) |
| 286 | { |
| 287 | struct sock *s; |
| 288 | |
| 289 | spin_lock(&unix_table_lock); |
| 290 | s = __unix_find_socket_byname(net, sunname, len, type, hash); |
| 291 | if (s) |
| 292 | sock_hold(s); |
| 293 | spin_unlock(&unix_table_lock); |
| 294 | return s; |
| 295 | } |
| 296 | |
| 297 | static struct sock *unix_find_socket_byinode(struct inode *i) |
| 298 | { |
| 299 | struct sock *s; |
| 300 | |
| 301 | spin_lock(&unix_table_lock); |
| 302 | sk_for_each(s, |
| 303 | &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
| 304 | struct dentry *dentry = unix_sk(s)->path.dentry; |
| 305 | |
| 306 | if (dentry && dentry->d_inode == i) { |
| 307 | sock_hold(s); |
| 308 | goto found; |
| 309 | } |
| 310 | } |
| 311 | s = NULL; |
| 312 | found: |
| 313 | spin_unlock(&unix_table_lock); |
| 314 | return s; |
| 315 | } |
| 316 | |
| 317 | static inline int unix_writable(struct sock *sk) |
| 318 | { |
| 319 | return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; |
| 320 | } |
| 321 | |
| 322 | static void unix_write_space(struct sock *sk) |
| 323 | { |
| 324 | struct socket_wq *wq; |
| 325 | |
| 326 | rcu_read_lock(); |
| 327 | if (unix_writable(sk)) { |
| 328 | wq = rcu_dereference(sk->sk_wq); |
| 329 | if (wq_has_sleeper(wq)) |
| 330 | wake_up_interruptible_sync_poll(&wq->wait, |
| 331 | POLLOUT | POLLWRNORM | POLLWRBAND); |
| 332 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
| 333 | } |
| 334 | rcu_read_unlock(); |
| 335 | } |
| 336 | |
| 337 | /* When dgram socket disconnects (or changes its peer), we clear its receive |
| 338 | * queue of packets arrived from previous peer. First, it allows to do |
| 339 | * flow control based only on wmem_alloc; second, sk connected to peer |
| 340 | * may receive messages only from that peer. */ |
| 341 | static void unix_dgram_disconnected(struct sock *sk, struct sock *other) |
| 342 | { |
| 343 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
| 344 | skb_queue_purge(&sk->sk_receive_queue); |
| 345 | wake_up_interruptible_all(&unix_sk(sk)->peer_wait); |
| 346 | |
| 347 | /* If one link of bidirectional dgram pipe is disconnected, |
| 348 | * we signal error. Messages are lost. Do not make this, |
| 349 | * when peer was not connected to us. |
| 350 | */ |
| 351 | if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { |
| 352 | other->sk_err = ECONNRESET; |
| 353 | other->sk_error_report(other); |
| 354 | } |
| 355 | } |
| 356 | } |
| 357 | |
| 358 | static void unix_sock_destructor(struct sock *sk) |
| 359 | { |
| 360 | struct unix_sock *u = unix_sk(sk); |
| 361 | |
| 362 | skb_queue_purge(&sk->sk_receive_queue); |
| 363 | |
| 364 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
| 365 | WARN_ON(!sk_unhashed(sk)); |
| 366 | WARN_ON(sk->sk_socket); |
| 367 | if (!sock_flag(sk, SOCK_DEAD)) { |
| 368 | printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk); |
| 369 | return; |
| 370 | } |
| 371 | |
| 372 | if (u->addr) |
| 373 | unix_release_addr(u->addr); |
| 374 | |
| 375 | atomic_long_dec(&unix_nr_socks); |
| 376 | local_bh_disable(); |
| 377 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
| 378 | local_bh_enable(); |
| 379 | #ifdef UNIX_REFCNT_DEBUG |
| 380 | printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk, |
| 381 | atomic_long_read(&unix_nr_socks)); |
| 382 | #endif |
| 383 | } |
| 384 | |
| 385 | static void unix_release_sock(struct sock *sk, int embrion) |
| 386 | { |
| 387 | struct unix_sock *u = unix_sk(sk); |
| 388 | struct path path; |
| 389 | struct sock *skpair; |
| 390 | struct sk_buff *skb; |
| 391 | int state; |
| 392 | |
| 393 | unix_remove_socket(sk); |
| 394 | |
| 395 | /* Clear state */ |
| 396 | unix_state_lock(sk); |
| 397 | sock_orphan(sk); |
| 398 | sk->sk_shutdown = SHUTDOWN_MASK; |
| 399 | path = u->path; |
| 400 | u->path.dentry = NULL; |
| 401 | u->path.mnt = NULL; |
| 402 | state = sk->sk_state; |
| 403 | sk->sk_state = TCP_CLOSE; |
| 404 | unix_state_unlock(sk); |
| 405 | |
| 406 | wake_up_interruptible_all(&u->peer_wait); |
| 407 | |
| 408 | skpair = unix_peer(sk); |
| 409 | |
| 410 | if (skpair != NULL) { |
| 411 | if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
| 412 | unix_state_lock(skpair); |
| 413 | /* No more writes */ |
| 414 | skpair->sk_shutdown = SHUTDOWN_MASK; |
| 415 | if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) |
| 416 | skpair->sk_err = ECONNRESET; |
| 417 | unix_state_unlock(skpair); |
| 418 | skpair->sk_state_change(skpair); |
| 419 | sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
| 420 | } |
| 421 | sock_put(skpair); /* It may now die */ |
| 422 | unix_peer(sk) = NULL; |
| 423 | } |
| 424 | |
| 425 | /* Try to flush out this socket. Throw out buffers at least */ |
| 426 | |
| 427 | while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { |
| 428 | if (state == TCP_LISTEN) |
| 429 | unix_release_sock(skb->sk, 1); |
| 430 | /* passed fds are erased in the kfree_skb hook */ |
| 431 | kfree_skb(skb); |
| 432 | } |
| 433 | |
| 434 | if (path.dentry) |
| 435 | path_put(&path); |
| 436 | |
| 437 | sock_put(sk); |
| 438 | |
| 439 | /* ---- Socket is dead now and most probably destroyed ---- */ |
| 440 | |
| 441 | /* |
| 442 | * Fixme: BSD difference: In BSD all sockets connected to us get |
| 443 | * ECONNRESET and we die on the spot. In Linux we behave |
| 444 | * like files and pipes do and wait for the last |
| 445 | * dereference. |
| 446 | * |
| 447 | * Can't we simply set sock->err? |
| 448 | * |
| 449 | * What the above comment does talk about? --ANK(980817) |
| 450 | */ |
| 451 | |
| 452 | if (unix_tot_inflight) |
| 453 | unix_gc(); /* Garbage collect fds */ |
| 454 | } |
| 455 | |
| 456 | static void init_peercred(struct sock *sk) |
| 457 | { |
| 458 | put_pid(sk->sk_peer_pid); |
| 459 | if (sk->sk_peer_cred) |
| 460 | put_cred(sk->sk_peer_cred); |
| 461 | sk->sk_peer_pid = get_pid(task_tgid(current)); |
| 462 | sk->sk_peer_cred = get_current_cred(); |
| 463 | } |
| 464 | |
| 465 | static void copy_peercred(struct sock *sk, struct sock *peersk) |
| 466 | { |
| 467 | put_pid(sk->sk_peer_pid); |
| 468 | if (sk->sk_peer_cred) |
| 469 | put_cred(sk->sk_peer_cred); |
| 470 | sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); |
| 471 | sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); |
| 472 | } |
| 473 | |
| 474 | static int unix_listen(struct socket *sock, int backlog) |
| 475 | { |
| 476 | int err; |
| 477 | struct sock *sk = sock->sk; |
| 478 | struct unix_sock *u = unix_sk(sk); |
| 479 | struct pid *old_pid = NULL; |
| 480 | |
| 481 | err = -EOPNOTSUPP; |
| 482 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
| 483 | goto out; /* Only stream/seqpacket sockets accept */ |
| 484 | err = -EINVAL; |
| 485 | if (!u->addr) |
| 486 | goto out; /* No listens on an unbound socket */ |
| 487 | unix_state_lock(sk); |
| 488 | if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
| 489 | goto out_unlock; |
| 490 | if (backlog > sk->sk_max_ack_backlog) |
| 491 | wake_up_interruptible_all(&u->peer_wait); |
| 492 | sk->sk_max_ack_backlog = backlog; |
| 493 | sk->sk_state = TCP_LISTEN; |
| 494 | /* set credentials so connect can copy them */ |
| 495 | init_peercred(sk); |
| 496 | err = 0; |
| 497 | |
| 498 | out_unlock: |
| 499 | unix_state_unlock(sk); |
| 500 | put_pid(old_pid); |
| 501 | out: |
| 502 | return err; |
| 503 | } |
| 504 | |
| 505 | static int unix_release(struct socket *); |
| 506 | static int unix_bind(struct socket *, struct sockaddr *, int); |
| 507 | static int unix_stream_connect(struct socket *, struct sockaddr *, |
| 508 | int addr_len, int flags); |
| 509 | static int unix_socketpair(struct socket *, struct socket *); |
| 510 | static int unix_accept(struct socket *, struct socket *, int); |
| 511 | static int unix_getname(struct socket *, struct sockaddr *, int *, int); |
| 512 | static unsigned int unix_poll(struct file *, struct socket *, poll_table *); |
| 513 | static unsigned int unix_dgram_poll(struct file *, struct socket *, |
| 514 | poll_table *); |
| 515 | static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
| 516 | static int unix_shutdown(struct socket *, int); |
| 517 | static int unix_stream_sendmsg(struct kiocb *, struct socket *, |
| 518 | struct msghdr *, size_t); |
| 519 | static int unix_stream_recvmsg(struct kiocb *, struct socket *, |
| 520 | struct msghdr *, size_t, int); |
| 521 | static int unix_dgram_sendmsg(struct kiocb *, struct socket *, |
| 522 | struct msghdr *, size_t); |
| 523 | static int unix_dgram_recvmsg(struct kiocb *, struct socket *, |
| 524 | struct msghdr *, size_t, int); |
| 525 | static int unix_dgram_connect(struct socket *, struct sockaddr *, |
| 526 | int, int); |
| 527 | static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, |
| 528 | struct msghdr *, size_t); |
| 529 | static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
| 530 | struct msghdr *, size_t, int); |
| 531 | |
| 532 | static void unix_set_peek_off(struct sock *sk, int val) |
| 533 | { |
| 534 | struct unix_sock *u = unix_sk(sk); |
| 535 | |
| 536 | mutex_lock(&u->readlock); |
| 537 | sk->sk_peek_off = val; |
| 538 | mutex_unlock(&u->readlock); |
| 539 | } |
| 540 | |
| 541 | |
| 542 | static const struct proto_ops unix_stream_ops = { |
| 543 | .family = PF_UNIX, |
| 544 | .owner = THIS_MODULE, |
| 545 | .release = unix_release, |
| 546 | .bind = unix_bind, |
| 547 | .connect = unix_stream_connect, |
| 548 | .socketpair = unix_socketpair, |
| 549 | .accept = unix_accept, |
| 550 | .getname = unix_getname, |
| 551 | .poll = unix_poll, |
| 552 | .ioctl = unix_ioctl, |
| 553 | .listen = unix_listen, |
| 554 | .shutdown = unix_shutdown, |
| 555 | .setsockopt = sock_no_setsockopt, |
| 556 | .getsockopt = sock_no_getsockopt, |
| 557 | .sendmsg = unix_stream_sendmsg, |
| 558 | .recvmsg = unix_stream_recvmsg, |
| 559 | .mmap = sock_no_mmap, |
| 560 | .sendpage = sock_no_sendpage, |
| 561 | .set_peek_off = unix_set_peek_off, |
| 562 | }; |
| 563 | |
| 564 | static const struct proto_ops unix_dgram_ops = { |
| 565 | .family = PF_UNIX, |
| 566 | .owner = THIS_MODULE, |
| 567 | .release = unix_release, |
| 568 | .bind = unix_bind, |
| 569 | .connect = unix_dgram_connect, |
| 570 | .socketpair = unix_socketpair, |
| 571 | .accept = sock_no_accept, |
| 572 | .getname = unix_getname, |
| 573 | .poll = unix_dgram_poll, |
| 574 | .ioctl = unix_ioctl, |
| 575 | .listen = sock_no_listen, |
| 576 | .shutdown = unix_shutdown, |
| 577 | .setsockopt = sock_no_setsockopt, |
| 578 | .getsockopt = sock_no_getsockopt, |
| 579 | .sendmsg = unix_dgram_sendmsg, |
| 580 | .recvmsg = unix_dgram_recvmsg, |
| 581 | .mmap = sock_no_mmap, |
| 582 | .sendpage = sock_no_sendpage, |
| 583 | .set_peek_off = unix_set_peek_off, |
| 584 | }; |
| 585 | |
| 586 | static const struct proto_ops unix_seqpacket_ops = { |
| 587 | .family = PF_UNIX, |
| 588 | .owner = THIS_MODULE, |
| 589 | .release = unix_release, |
| 590 | .bind = unix_bind, |
| 591 | .connect = unix_stream_connect, |
| 592 | .socketpair = unix_socketpair, |
| 593 | .accept = unix_accept, |
| 594 | .getname = unix_getname, |
| 595 | .poll = unix_dgram_poll, |
| 596 | .ioctl = unix_ioctl, |
| 597 | .listen = unix_listen, |
| 598 | .shutdown = unix_shutdown, |
| 599 | .setsockopt = sock_no_setsockopt, |
| 600 | .getsockopt = sock_no_getsockopt, |
| 601 | .sendmsg = unix_seqpacket_sendmsg, |
| 602 | .recvmsg = unix_seqpacket_recvmsg, |
| 603 | .mmap = sock_no_mmap, |
| 604 | .sendpage = sock_no_sendpage, |
| 605 | .set_peek_off = unix_set_peek_off, |
| 606 | }; |
| 607 | |
| 608 | static struct proto unix_proto = { |
| 609 | .name = "UNIX", |
| 610 | .owner = THIS_MODULE, |
| 611 | .obj_size = sizeof(struct unix_sock), |
| 612 | }; |
| 613 | |
| 614 | /* |
| 615 | * AF_UNIX sockets do not interact with hardware, hence they |
| 616 | * dont trigger interrupts - so it's safe for them to have |
| 617 | * bh-unsafe locking for their sk_receive_queue.lock. Split off |
| 618 | * this special lock-class by reinitializing the spinlock key: |
| 619 | */ |
| 620 | static struct lock_class_key af_unix_sk_receive_queue_lock_key; |
| 621 | |
| 622 | static struct sock *unix_create1(struct net *net, struct socket *sock) |
| 623 | { |
| 624 | struct sock *sk = NULL; |
| 625 | struct unix_sock *u; |
| 626 | |
| 627 | atomic_long_inc(&unix_nr_socks); |
| 628 | if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) |
| 629 | goto out; |
| 630 | |
| 631 | sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
| 632 | if (!sk) |
| 633 | goto out; |
| 634 | |
| 635 | sock_init_data(sock, sk); |
| 636 | lockdep_set_class(&sk->sk_receive_queue.lock, |
| 637 | &af_unix_sk_receive_queue_lock_key); |
| 638 | |
| 639 | sk->sk_write_space = unix_write_space; |
| 640 | sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
| 641 | sk->sk_destruct = unix_sock_destructor; |
| 642 | u = unix_sk(sk); |
| 643 | u->path.dentry = NULL; |
| 644 | u->path.mnt = NULL; |
| 645 | spin_lock_init(&u->lock); |
| 646 | atomic_long_set(&u->inflight, 0); |
| 647 | INIT_LIST_HEAD(&u->link); |
| 648 | mutex_init(&u->readlock); /* single task reading lock */ |
| 649 | init_waitqueue_head(&u->peer_wait); |
| 650 | unix_insert_socket(unix_sockets_unbound(sk), sk); |
| 651 | out: |
| 652 | if (sk == NULL) |
| 653 | atomic_long_dec(&unix_nr_socks); |
| 654 | else { |
| 655 | local_bh_disable(); |
| 656 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
| 657 | local_bh_enable(); |
| 658 | } |
| 659 | return sk; |
| 660 | } |
| 661 | |
| 662 | static int unix_create(struct net *net, struct socket *sock, int protocol, |
| 663 | int kern) |
| 664 | { |
| 665 | if (protocol && protocol != PF_UNIX) |
| 666 | return -EPROTONOSUPPORT; |
| 667 | |
| 668 | sock->state = SS_UNCONNECTED; |
| 669 | |
| 670 | switch (sock->type) { |
| 671 | case SOCK_STREAM: |
| 672 | sock->ops = &unix_stream_ops; |
| 673 | break; |
| 674 | /* |
| 675 | * Believe it or not BSD has AF_UNIX, SOCK_RAW though |
| 676 | * nothing uses it. |
| 677 | */ |
| 678 | case SOCK_RAW: |
| 679 | sock->type = SOCK_DGRAM; |
| 680 | case SOCK_DGRAM: |
| 681 | sock->ops = &unix_dgram_ops; |
| 682 | break; |
| 683 | case SOCK_SEQPACKET: |
| 684 | sock->ops = &unix_seqpacket_ops; |
| 685 | break; |
| 686 | default: |
| 687 | return -ESOCKTNOSUPPORT; |
| 688 | } |
| 689 | |
| 690 | return unix_create1(net, sock) ? 0 : -ENOMEM; |
| 691 | } |
| 692 | |
| 693 | static int unix_release(struct socket *sock) |
| 694 | { |
| 695 | struct sock *sk = sock->sk; |
| 696 | |
| 697 | if (!sk) |
| 698 | return 0; |
| 699 | |
| 700 | unix_release_sock(sk, 0); |
| 701 | sock->sk = NULL; |
| 702 | |
| 703 | return 0; |
| 704 | } |
| 705 | |
| 706 | static int unix_autobind(struct socket *sock) |
| 707 | { |
| 708 | struct sock *sk = sock->sk; |
| 709 | struct net *net = sock_net(sk); |
| 710 | struct unix_sock *u = unix_sk(sk); |
| 711 | static u32 ordernum = 1; |
| 712 | struct unix_address *addr; |
| 713 | int err; |
| 714 | unsigned int retries = 0; |
| 715 | |
| 716 | mutex_lock(&u->readlock); |
| 717 | |
| 718 | err = 0; |
| 719 | if (u->addr) |
| 720 | goto out; |
| 721 | |
| 722 | err = -ENOMEM; |
| 723 | addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
| 724 | if (!addr) |
| 725 | goto out; |
| 726 | |
| 727 | addr->name->sun_family = AF_UNIX; |
| 728 | atomic_set(&addr->refcnt, 1); |
| 729 | |
| 730 | retry: |
| 731 | addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); |
| 732 | addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
| 733 | |
| 734 | spin_lock(&unix_table_lock); |
| 735 | ordernum = (ordernum+1)&0xFFFFF; |
| 736 | |
| 737 | if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
| 738 | addr->hash)) { |
| 739 | spin_unlock(&unix_table_lock); |
| 740 | /* |
| 741 | * __unix_find_socket_byname() may take long time if many names |
| 742 | * are already in use. |
| 743 | */ |
| 744 | cond_resched(); |
| 745 | /* Give up if all names seems to be in use. */ |
| 746 | if (retries++ == 0xFFFFF) { |
| 747 | err = -ENOSPC; |
| 748 | kfree(addr); |
| 749 | goto out; |
| 750 | } |
| 751 | goto retry; |
| 752 | } |
| 753 | addr->hash ^= sk->sk_type; |
| 754 | |
| 755 | __unix_remove_socket(sk); |
| 756 | u->addr = addr; |
| 757 | __unix_insert_socket(&unix_socket_table[addr->hash], sk); |
| 758 | spin_unlock(&unix_table_lock); |
| 759 | err = 0; |
| 760 | |
| 761 | out: mutex_unlock(&u->readlock); |
| 762 | return err; |
| 763 | } |
| 764 | |
| 765 | static struct sock *unix_find_other(struct net *net, |
| 766 | struct sockaddr_un *sunname, int len, |
| 767 | int type, unsigned int hash, int *error) |
| 768 | { |
| 769 | struct sock *u; |
| 770 | struct path path; |
| 771 | int err = 0; |
| 772 | |
| 773 | if (sunname->sun_path[0]) { |
| 774 | struct inode *inode; |
| 775 | err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); |
| 776 | if (err) |
| 777 | goto fail; |
| 778 | inode = path.dentry->d_inode; |
| 779 | err = inode_permission(inode, MAY_WRITE); |
| 780 | if (err) |
| 781 | goto put_fail; |
| 782 | |
| 783 | err = -ECONNREFUSED; |
| 784 | if (!S_ISSOCK(inode->i_mode)) |
| 785 | goto put_fail; |
| 786 | u = unix_find_socket_byinode(inode); |
| 787 | if (!u) |
| 788 | goto put_fail; |
| 789 | |
| 790 | if (u->sk_type == type) |
| 791 | touch_atime(&path); |
| 792 | |
| 793 | path_put(&path); |
| 794 | |
| 795 | err = -EPROTOTYPE; |
| 796 | if (u->sk_type != type) { |
| 797 | sock_put(u); |
| 798 | goto fail; |
| 799 | } |
| 800 | } else { |
| 801 | err = -ECONNREFUSED; |
| 802 | u = unix_find_socket_byname(net, sunname, len, type, hash); |
| 803 | if (u) { |
| 804 | struct dentry *dentry; |
| 805 | dentry = unix_sk(u)->path.dentry; |
| 806 | if (dentry) |
| 807 | touch_atime(&unix_sk(u)->path); |
| 808 | } else |
| 809 | goto fail; |
| 810 | } |
| 811 | return u; |
| 812 | |
| 813 | put_fail: |
| 814 | path_put(&path); |
| 815 | fail: |
| 816 | *error = err; |
| 817 | return NULL; |
| 818 | } |
| 819 | |
| 820 | static int unix_mknod(const char *sun_path, umode_t mode, struct path *res) |
| 821 | { |
| 822 | struct dentry *dentry; |
| 823 | struct path path; |
| 824 | int err = 0; |
| 825 | /* |
| 826 | * Get the parent directory, calculate the hash for last |
| 827 | * component. |
| 828 | */ |
| 829 | dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); |
| 830 | err = PTR_ERR(dentry); |
| 831 | if (IS_ERR(dentry)) |
| 832 | return err; |
| 833 | |
| 834 | /* |
| 835 | * All right, let's create it. |
| 836 | */ |
| 837 | err = security_path_mknod(&path, dentry, mode, 0); |
| 838 | if (!err) { |
| 839 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); |
| 840 | if (!err) { |
| 841 | res->mnt = mntget(path.mnt); |
| 842 | res->dentry = dget(dentry); |
| 843 | } |
| 844 | } |
| 845 | done_path_create(&path, dentry); |
| 846 | return err; |
| 847 | } |
| 848 | |
| 849 | static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
| 850 | { |
| 851 | struct sock *sk = sock->sk; |
| 852 | struct net *net = sock_net(sk); |
| 853 | struct unix_sock *u = unix_sk(sk); |
| 854 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
| 855 | char *sun_path = sunaddr->sun_path; |
| 856 | int err; |
| 857 | unsigned int hash; |
| 858 | struct unix_address *addr; |
| 859 | struct hlist_head *list; |
| 860 | |
| 861 | err = -EINVAL; |
| 862 | if (sunaddr->sun_family != AF_UNIX) |
| 863 | goto out; |
| 864 | |
| 865 | if (addr_len == sizeof(short)) { |
| 866 | err = unix_autobind(sock); |
| 867 | goto out; |
| 868 | } |
| 869 | |
| 870 | err = unix_mkname(sunaddr, addr_len, &hash); |
| 871 | if (err < 0) |
| 872 | goto out; |
| 873 | addr_len = err; |
| 874 | |
| 875 | mutex_lock(&u->readlock); |
| 876 | |
| 877 | err = -EINVAL; |
| 878 | if (u->addr) |
| 879 | goto out_up; |
| 880 | |
| 881 | err = -ENOMEM; |
| 882 | addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); |
| 883 | if (!addr) |
| 884 | goto out_up; |
| 885 | |
| 886 | memcpy(addr->name, sunaddr, addr_len); |
| 887 | addr->len = addr_len; |
| 888 | addr->hash = hash ^ sk->sk_type; |
| 889 | atomic_set(&addr->refcnt, 1); |
| 890 | |
| 891 | if (sun_path[0]) { |
| 892 | struct path path; |
| 893 | umode_t mode = S_IFSOCK | |
| 894 | (SOCK_INODE(sock)->i_mode & ~current_umask()); |
| 895 | err = unix_mknod(sun_path, mode, &path); |
| 896 | if (err) { |
| 897 | if (err == -EEXIST) |
| 898 | err = -EADDRINUSE; |
| 899 | unix_release_addr(addr); |
| 900 | goto out_up; |
| 901 | } |
| 902 | addr->hash = UNIX_HASH_SIZE; |
| 903 | hash = path.dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1); |
| 904 | spin_lock(&unix_table_lock); |
| 905 | u->path = path; |
| 906 | list = &unix_socket_table[hash]; |
| 907 | } else { |
| 908 | spin_lock(&unix_table_lock); |
| 909 | err = -EADDRINUSE; |
| 910 | if (__unix_find_socket_byname(net, sunaddr, addr_len, |
| 911 | sk->sk_type, hash)) { |
| 912 | unix_release_addr(addr); |
| 913 | goto out_unlock; |
| 914 | } |
| 915 | |
| 916 | list = &unix_socket_table[addr->hash]; |
| 917 | } |
| 918 | |
| 919 | err = 0; |
| 920 | __unix_remove_socket(sk); |
| 921 | u->addr = addr; |
| 922 | __unix_insert_socket(list, sk); |
| 923 | |
| 924 | out_unlock: |
| 925 | spin_unlock(&unix_table_lock); |
| 926 | out_up: |
| 927 | mutex_unlock(&u->readlock); |
| 928 | out: |
| 929 | return err; |
| 930 | } |
| 931 | |
| 932 | static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
| 933 | { |
| 934 | if (unlikely(sk1 == sk2) || !sk2) { |
| 935 | unix_state_lock(sk1); |
| 936 | return; |
| 937 | } |
| 938 | if (sk1 < sk2) { |
| 939 | unix_state_lock(sk1); |
| 940 | unix_state_lock_nested(sk2); |
| 941 | } else { |
| 942 | unix_state_lock(sk2); |
| 943 | unix_state_lock_nested(sk1); |
| 944 | } |
| 945 | } |
| 946 | |
| 947 | static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) |
| 948 | { |
| 949 | if (unlikely(sk1 == sk2) || !sk2) { |
| 950 | unix_state_unlock(sk1); |
| 951 | return; |
| 952 | } |
| 953 | unix_state_unlock(sk1); |
| 954 | unix_state_unlock(sk2); |
| 955 | } |
| 956 | |
| 957 | static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
| 958 | int alen, int flags) |
| 959 | { |
| 960 | struct sock *sk = sock->sk; |
| 961 | struct net *net = sock_net(sk); |
| 962 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
| 963 | struct sock *other; |
| 964 | unsigned int hash; |
| 965 | int err; |
| 966 | |
| 967 | if (addr->sa_family != AF_UNSPEC) { |
| 968 | err = unix_mkname(sunaddr, alen, &hash); |
| 969 | if (err < 0) |
| 970 | goto out; |
| 971 | alen = err; |
| 972 | |
| 973 | if (test_bit(SOCK_PASSCRED, &sock->flags) && |
| 974 | !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) |
| 975 | goto out; |
| 976 | |
| 977 | restart: |
| 978 | other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
| 979 | if (!other) |
| 980 | goto out; |
| 981 | |
| 982 | unix_state_double_lock(sk, other); |
| 983 | |
| 984 | /* Apparently VFS overslept socket death. Retry. */ |
| 985 | if (sock_flag(other, SOCK_DEAD)) { |
| 986 | unix_state_double_unlock(sk, other); |
| 987 | sock_put(other); |
| 988 | goto restart; |
| 989 | } |
| 990 | |
| 991 | err = -EPERM; |
| 992 | if (!unix_may_send(sk, other)) |
| 993 | goto out_unlock; |
| 994 | |
| 995 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
| 996 | if (err) |
| 997 | goto out_unlock; |
| 998 | |
| 999 | } else { |
| 1000 | /* |
| 1001 | * 1003.1g breaking connected state with AF_UNSPEC |
| 1002 | */ |
| 1003 | other = NULL; |
| 1004 | unix_state_double_lock(sk, other); |
| 1005 | } |
| 1006 | |
| 1007 | /* |
| 1008 | * If it was connected, reconnect. |
| 1009 | */ |
| 1010 | if (unix_peer(sk)) { |
| 1011 | struct sock *old_peer = unix_peer(sk); |
| 1012 | unix_peer(sk) = other; |
| 1013 | unix_state_double_unlock(sk, other); |
| 1014 | |
| 1015 | if (other != old_peer) |
| 1016 | unix_dgram_disconnected(sk, old_peer); |
| 1017 | sock_put(old_peer); |
| 1018 | } else { |
| 1019 | unix_peer(sk) = other; |
| 1020 | unix_state_double_unlock(sk, other); |
| 1021 | } |
| 1022 | return 0; |
| 1023 | |
| 1024 | out_unlock: |
| 1025 | unix_state_double_unlock(sk, other); |
| 1026 | sock_put(other); |
| 1027 | out: |
| 1028 | return err; |
| 1029 | } |
| 1030 | |
| 1031 | static long unix_wait_for_peer(struct sock *other, long timeo) |
| 1032 | { |
| 1033 | struct unix_sock *u = unix_sk(other); |
| 1034 | int sched; |
| 1035 | DEFINE_WAIT(wait); |
| 1036 | |
| 1037 | prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); |
| 1038 | |
| 1039 | sched = !sock_flag(other, SOCK_DEAD) && |
| 1040 | !(other->sk_shutdown & RCV_SHUTDOWN) && |
| 1041 | unix_recvq_full(other); |
| 1042 | |
| 1043 | unix_state_unlock(other); |
| 1044 | |
| 1045 | if (sched) |
| 1046 | timeo = schedule_timeout(timeo); |
| 1047 | |
| 1048 | finish_wait(&u->peer_wait, &wait); |
| 1049 | return timeo; |
| 1050 | } |
| 1051 | |
| 1052 | static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, |
| 1053 | int addr_len, int flags) |
| 1054 | { |
| 1055 | struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
| 1056 | struct sock *sk = sock->sk; |
| 1057 | struct net *net = sock_net(sk); |
| 1058 | struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
| 1059 | struct sock *newsk = NULL; |
| 1060 | struct sock *other = NULL; |
| 1061 | struct sk_buff *skb = NULL; |
| 1062 | unsigned int hash; |
| 1063 | int st; |
| 1064 | int err; |
| 1065 | long timeo; |
| 1066 | |
| 1067 | err = unix_mkname(sunaddr, addr_len, &hash); |
| 1068 | if (err < 0) |
| 1069 | goto out; |
| 1070 | addr_len = err; |
| 1071 | |
| 1072 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
| 1073 | (err = unix_autobind(sock)) != 0) |
| 1074 | goto out; |
| 1075 | |
| 1076 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); |
| 1077 | |
| 1078 | /* First of all allocate resources. |
| 1079 | If we will make it after state is locked, |
| 1080 | we will have to recheck all again in any case. |
| 1081 | */ |
| 1082 | |
| 1083 | err = -ENOMEM; |
| 1084 | |
| 1085 | /* create new sock for complete connection */ |
| 1086 | newsk = unix_create1(sock_net(sk), NULL); |
| 1087 | if (newsk == NULL) |
| 1088 | goto out; |
| 1089 | |
| 1090 | /* Allocate skb for sending to listening sock */ |
| 1091 | skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); |
| 1092 | if (skb == NULL) |
| 1093 | goto out; |
| 1094 | |
| 1095 | restart: |
| 1096 | /* Find listening sock. */ |
| 1097 | other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
| 1098 | if (!other) |
| 1099 | goto out; |
| 1100 | |
| 1101 | /* Latch state of peer */ |
| 1102 | unix_state_lock(other); |
| 1103 | |
| 1104 | /* Apparently VFS overslept socket death. Retry. */ |
| 1105 | if (sock_flag(other, SOCK_DEAD)) { |
| 1106 | unix_state_unlock(other); |
| 1107 | sock_put(other); |
| 1108 | goto restart; |
| 1109 | } |
| 1110 | |
| 1111 | err = -ECONNREFUSED; |
| 1112 | if (other->sk_state != TCP_LISTEN) |
| 1113 | goto out_unlock; |
| 1114 | if (other->sk_shutdown & RCV_SHUTDOWN) |
| 1115 | goto out_unlock; |
| 1116 | |
| 1117 | if (unix_recvq_full(other)) { |
| 1118 | err = -EAGAIN; |
| 1119 | if (!timeo) |
| 1120 | goto out_unlock; |
| 1121 | |
| 1122 | timeo = unix_wait_for_peer(other, timeo); |
| 1123 | |
| 1124 | err = sock_intr_errno(timeo); |
| 1125 | if (signal_pending(current)) |
| 1126 | goto out; |
| 1127 | sock_put(other); |
| 1128 | goto restart; |
| 1129 | } |
| 1130 | |
| 1131 | /* Latch our state. |
| 1132 | |
| 1133 | It is tricky place. We need to grab our state lock and cannot |
| 1134 | drop lock on peer. It is dangerous because deadlock is |
| 1135 | possible. Connect to self case and simultaneous |
| 1136 | attempt to connect are eliminated by checking socket |
| 1137 | state. other is TCP_LISTEN, if sk is TCP_LISTEN we |
| 1138 | check this before attempt to grab lock. |
| 1139 | |
| 1140 | Well, and we have to recheck the state after socket locked. |
| 1141 | */ |
| 1142 | st = sk->sk_state; |
| 1143 | |
| 1144 | switch (st) { |
| 1145 | case TCP_CLOSE: |
| 1146 | /* This is ok... continue with connect */ |
| 1147 | break; |
| 1148 | case TCP_ESTABLISHED: |
| 1149 | /* Socket is already connected */ |
| 1150 | err = -EISCONN; |
| 1151 | goto out_unlock; |
| 1152 | default: |
| 1153 | err = -EINVAL; |
| 1154 | goto out_unlock; |
| 1155 | } |
| 1156 | |
| 1157 | unix_state_lock_nested(sk); |
| 1158 | |
| 1159 | if (sk->sk_state != st) { |
| 1160 | unix_state_unlock(sk); |
| 1161 | unix_state_unlock(other); |
| 1162 | sock_put(other); |
| 1163 | goto restart; |
| 1164 | } |
| 1165 | |
| 1166 | err = security_unix_stream_connect(sk, other, newsk); |
| 1167 | if (err) { |
| 1168 | unix_state_unlock(sk); |
| 1169 | goto out_unlock; |
| 1170 | } |
| 1171 | |
| 1172 | /* The way is open! Fastly set all the necessary fields... */ |
| 1173 | |
| 1174 | sock_hold(sk); |
| 1175 | unix_peer(newsk) = sk; |
| 1176 | newsk->sk_state = TCP_ESTABLISHED; |
| 1177 | newsk->sk_type = sk->sk_type; |
| 1178 | init_peercred(newsk); |
| 1179 | newu = unix_sk(newsk); |
| 1180 | RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
| 1181 | otheru = unix_sk(other); |
| 1182 | |
| 1183 | /* copy address information from listening to new sock*/ |
| 1184 | if (otheru->addr) { |
| 1185 | atomic_inc(&otheru->addr->refcnt); |
| 1186 | newu->addr = otheru->addr; |
| 1187 | } |
| 1188 | if (otheru->path.dentry) { |
| 1189 | path_get(&otheru->path); |
| 1190 | newu->path = otheru->path; |
| 1191 | } |
| 1192 | |
| 1193 | /* Set credentials */ |
| 1194 | copy_peercred(sk, other); |
| 1195 | |
| 1196 | sock->state = SS_CONNECTED; |
| 1197 | sk->sk_state = TCP_ESTABLISHED; |
| 1198 | sock_hold(newsk); |
| 1199 | |
| 1200 | smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ |
| 1201 | unix_peer(sk) = newsk; |
| 1202 | |
| 1203 | unix_state_unlock(sk); |
| 1204 | |
| 1205 | /* take ten and and send info to listening sock */ |
| 1206 | spin_lock(&other->sk_receive_queue.lock); |
| 1207 | __skb_queue_tail(&other->sk_receive_queue, skb); |
| 1208 | spin_unlock(&other->sk_receive_queue.lock); |
| 1209 | unix_state_unlock(other); |
| 1210 | other->sk_data_ready(other, 0); |
| 1211 | sock_put(other); |
| 1212 | return 0; |
| 1213 | |
| 1214 | out_unlock: |
| 1215 | if (other) |
| 1216 | unix_state_unlock(other); |
| 1217 | |
| 1218 | out: |
| 1219 | kfree_skb(skb); |
| 1220 | if (newsk) |
| 1221 | unix_release_sock(newsk, 0); |
| 1222 | if (other) |
| 1223 | sock_put(other); |
| 1224 | return err; |
| 1225 | } |
| 1226 | |
| 1227 | static int unix_socketpair(struct socket *socka, struct socket *sockb) |
| 1228 | { |
| 1229 | struct sock *ska = socka->sk, *skb = sockb->sk; |
| 1230 | |
| 1231 | /* Join our sockets back to back */ |
| 1232 | sock_hold(ska); |
| 1233 | sock_hold(skb); |
| 1234 | unix_peer(ska) = skb; |
| 1235 | unix_peer(skb) = ska; |
| 1236 | init_peercred(ska); |
| 1237 | init_peercred(skb); |
| 1238 | |
| 1239 | if (ska->sk_type != SOCK_DGRAM) { |
| 1240 | ska->sk_state = TCP_ESTABLISHED; |
| 1241 | skb->sk_state = TCP_ESTABLISHED; |
| 1242 | socka->state = SS_CONNECTED; |
| 1243 | sockb->state = SS_CONNECTED; |
| 1244 | } |
| 1245 | return 0; |
| 1246 | } |
| 1247 | |
| 1248 | static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
| 1249 | { |
| 1250 | struct sock *sk = sock->sk; |
| 1251 | struct sock *tsk; |
| 1252 | struct sk_buff *skb; |
| 1253 | int err; |
| 1254 | |
| 1255 | err = -EOPNOTSUPP; |
| 1256 | if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
| 1257 | goto out; |
| 1258 | |
| 1259 | err = -EINVAL; |
| 1260 | if (sk->sk_state != TCP_LISTEN) |
| 1261 | goto out; |
| 1262 | |
| 1263 | /* If socket state is TCP_LISTEN it cannot change (for now...), |
| 1264 | * so that no locks are necessary. |
| 1265 | */ |
| 1266 | |
| 1267 | skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); |
| 1268 | if (!skb) { |
| 1269 | /* This means receive shutdown. */ |
| 1270 | if (err == 0) |
| 1271 | err = -EINVAL; |
| 1272 | goto out; |
| 1273 | } |
| 1274 | |
| 1275 | tsk = skb->sk; |
| 1276 | skb_free_datagram(sk, skb); |
| 1277 | wake_up_interruptible(&unix_sk(sk)->peer_wait); |
| 1278 | |
| 1279 | /* attach accepted sock to socket */ |
| 1280 | unix_state_lock(tsk); |
| 1281 | newsock->state = SS_CONNECTED; |
| 1282 | sock_graft(tsk, newsock); |
| 1283 | unix_state_unlock(tsk); |
| 1284 | return 0; |
| 1285 | |
| 1286 | out: |
| 1287 | return err; |
| 1288 | } |
| 1289 | |
| 1290 | |
| 1291 | static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) |
| 1292 | { |
| 1293 | struct sock *sk = sock->sk; |
| 1294 | struct unix_sock *u; |
| 1295 | DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
| 1296 | int err = 0; |
| 1297 | |
| 1298 | if (peer) { |
| 1299 | sk = unix_peer_get(sk); |
| 1300 | |
| 1301 | err = -ENOTCONN; |
| 1302 | if (!sk) |
| 1303 | goto out; |
| 1304 | err = 0; |
| 1305 | } else { |
| 1306 | sock_hold(sk); |
| 1307 | } |
| 1308 | |
| 1309 | u = unix_sk(sk); |
| 1310 | unix_state_lock(sk); |
| 1311 | if (!u->addr) { |
| 1312 | sunaddr->sun_family = AF_UNIX; |
| 1313 | sunaddr->sun_path[0] = 0; |
| 1314 | *uaddr_len = sizeof(short); |
| 1315 | } else { |
| 1316 | struct unix_address *addr = u->addr; |
| 1317 | |
| 1318 | *uaddr_len = addr->len; |
| 1319 | memcpy(sunaddr, addr->name, *uaddr_len); |
| 1320 | } |
| 1321 | unix_state_unlock(sk); |
| 1322 | sock_put(sk); |
| 1323 | out: |
| 1324 | return err; |
| 1325 | } |
| 1326 | |
| 1327 | static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
| 1328 | { |
| 1329 | int i; |
| 1330 | |
| 1331 | scm->fp = UNIXCB(skb).fp; |
| 1332 | UNIXCB(skb).fp = NULL; |
| 1333 | |
| 1334 | for (i = scm->fp->count-1; i >= 0; i--) |
| 1335 | unix_notinflight(scm->fp->fp[i]); |
| 1336 | } |
| 1337 | |
| 1338 | static void unix_destruct_scm(struct sk_buff *skb) |
| 1339 | { |
| 1340 | struct scm_cookie scm; |
| 1341 | memset(&scm, 0, sizeof(scm)); |
| 1342 | scm.pid = UNIXCB(skb).pid; |
| 1343 | scm.cred = UNIXCB(skb).cred; |
| 1344 | if (UNIXCB(skb).fp) |
| 1345 | unix_detach_fds(&scm, skb); |
| 1346 | |
| 1347 | /* Alas, it calls VFS */ |
| 1348 | /* So fscking what? fput() had been SMP-safe since the last Summer */ |
| 1349 | scm_destroy(&scm); |
| 1350 | sock_wfree(skb); |
| 1351 | } |
| 1352 | |
| 1353 | #define MAX_RECURSION_LEVEL 4 |
| 1354 | |
| 1355 | static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
| 1356 | { |
| 1357 | int i; |
| 1358 | unsigned char max_level = 0; |
| 1359 | int unix_sock_count = 0; |
| 1360 | |
| 1361 | for (i = scm->fp->count - 1; i >= 0; i--) { |
| 1362 | struct sock *sk = unix_get_socket(scm->fp->fp[i]); |
| 1363 | |
| 1364 | if (sk) { |
| 1365 | unix_sock_count++; |
| 1366 | max_level = max(max_level, |
| 1367 | unix_sk(sk)->recursion_level); |
| 1368 | } |
| 1369 | } |
| 1370 | if (unlikely(max_level > MAX_RECURSION_LEVEL)) |
| 1371 | return -ETOOMANYREFS; |
| 1372 | |
| 1373 | /* |
| 1374 | * Need to duplicate file references for the sake of garbage |
| 1375 | * collection. Otherwise a socket in the fps might become a |
| 1376 | * candidate for GC while the skb is not yet queued. |
| 1377 | */ |
| 1378 | UNIXCB(skb).fp = scm_fp_dup(scm->fp); |
| 1379 | if (!UNIXCB(skb).fp) |
| 1380 | return -ENOMEM; |
| 1381 | |
| 1382 | if (unix_sock_count) { |
| 1383 | for (i = scm->fp->count - 1; i >= 0; i--) |
| 1384 | unix_inflight(scm->fp->fp[i]); |
| 1385 | } |
| 1386 | return max_level; |
| 1387 | } |
| 1388 | |
| 1389 | static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
| 1390 | { |
| 1391 | int err = 0; |
| 1392 | |
| 1393 | UNIXCB(skb).pid = get_pid(scm->pid); |
| 1394 | if (scm->cred) |
| 1395 | UNIXCB(skb).cred = get_cred(scm->cred); |
| 1396 | UNIXCB(skb).fp = NULL; |
| 1397 | if (scm->fp && send_fds) |
| 1398 | err = unix_attach_fds(scm, skb); |
| 1399 | |
| 1400 | skb->destructor = unix_destruct_scm; |
| 1401 | return err; |
| 1402 | } |
| 1403 | |
| 1404 | /* |
| 1405 | * Some apps rely on write() giving SCM_CREDENTIALS |
| 1406 | * We include credentials if source or destination socket |
| 1407 | * asserted SOCK_PASSCRED. |
| 1408 | */ |
| 1409 | static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, |
| 1410 | const struct sock *other) |
| 1411 | { |
| 1412 | if (UNIXCB(skb).cred) |
| 1413 | return; |
| 1414 | if (test_bit(SOCK_PASSCRED, &sock->flags) || |
| 1415 | (other->sk_socket && |
| 1416 | test_bit(SOCK_PASSCRED, &other->sk_socket->flags))) { |
| 1417 | UNIXCB(skb).pid = get_pid(task_tgid(current)); |
| 1418 | UNIXCB(skb).cred = get_current_cred(); |
| 1419 | } |
| 1420 | } |
| 1421 | |
| 1422 | /* |
| 1423 | * Send AF_UNIX data. |
| 1424 | */ |
| 1425 | |
| 1426 | static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| 1427 | struct msghdr *msg, size_t len) |
| 1428 | { |
| 1429 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
| 1430 | struct sock *sk = sock->sk; |
| 1431 | struct net *net = sock_net(sk); |
| 1432 | struct unix_sock *u = unix_sk(sk); |
| 1433 | struct sockaddr_un *sunaddr = msg->msg_name; |
| 1434 | struct sock *other = NULL; |
| 1435 | int namelen = 0; /* fake GCC */ |
| 1436 | int err; |
| 1437 | unsigned int hash; |
| 1438 | struct sk_buff *skb; |
| 1439 | long timeo; |
| 1440 | struct scm_cookie tmp_scm; |
| 1441 | int max_level; |
| 1442 | int data_len = 0; |
| 1443 | |
| 1444 | if (NULL == siocb->scm) |
| 1445 | siocb->scm = &tmp_scm; |
| 1446 | wait_for_unix_gc(); |
| 1447 | err = scm_send(sock, msg, siocb->scm, false); |
| 1448 | if (err < 0) |
| 1449 | return err; |
| 1450 | |
| 1451 | err = -EOPNOTSUPP; |
| 1452 | if (msg->msg_flags&MSG_OOB) |
| 1453 | goto out; |
| 1454 | |
| 1455 | if (msg->msg_namelen) { |
| 1456 | err = unix_mkname(sunaddr, msg->msg_namelen, &hash); |
| 1457 | if (err < 0) |
| 1458 | goto out; |
| 1459 | namelen = err; |
| 1460 | } else { |
| 1461 | sunaddr = NULL; |
| 1462 | err = -ENOTCONN; |
| 1463 | other = unix_peer_get(sk); |
| 1464 | if (!other) |
| 1465 | goto out; |
| 1466 | } |
| 1467 | |
| 1468 | if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
| 1469 | && (err = unix_autobind(sock)) != 0) |
| 1470 | goto out; |
| 1471 | |
| 1472 | err = -EMSGSIZE; |
| 1473 | if (len > sk->sk_sndbuf - 32) |
| 1474 | goto out; |
| 1475 | |
| 1476 | if (len > SKB_MAX_ALLOC) |
| 1477 | data_len = min_t(size_t, |
| 1478 | len - SKB_MAX_ALLOC, |
| 1479 | MAX_SKB_FRAGS * PAGE_SIZE); |
| 1480 | |
| 1481 | skb = sock_alloc_send_pskb(sk, len - data_len, data_len, |
| 1482 | msg->msg_flags & MSG_DONTWAIT, &err); |
| 1483 | if (skb == NULL) |
| 1484 | goto out; |
| 1485 | |
| 1486 | err = unix_scm_to_skb(siocb->scm, skb, true); |
| 1487 | if (err < 0) |
| 1488 | goto out_free; |
| 1489 | max_level = err + 1; |
| 1490 | unix_get_secdata(siocb->scm, skb); |
| 1491 | |
| 1492 | skb_put(skb, len - data_len); |
| 1493 | skb->data_len = data_len; |
| 1494 | skb->len = len; |
| 1495 | err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len); |
| 1496 | if (err) |
| 1497 | goto out_free; |
| 1498 | |
| 1499 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| 1500 | |
| 1501 | restart: |
| 1502 | if (!other) { |
| 1503 | err = -ECONNRESET; |
| 1504 | if (sunaddr == NULL) |
| 1505 | goto out_free; |
| 1506 | |
| 1507 | other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
| 1508 | hash, &err); |
| 1509 | if (other == NULL) |
| 1510 | goto out_free; |
| 1511 | } |
| 1512 | |
| 1513 | if (sk_filter(other, skb) < 0) { |
| 1514 | /* Toss the packet but do not return any error to the sender */ |
| 1515 | err = len; |
| 1516 | goto out_free; |
| 1517 | } |
| 1518 | |
| 1519 | unix_state_lock(other); |
| 1520 | err = -EPERM; |
| 1521 | if (!unix_may_send(sk, other)) |
| 1522 | goto out_unlock; |
| 1523 | |
| 1524 | if (sock_flag(other, SOCK_DEAD)) { |
| 1525 | /* |
| 1526 | * Check with 1003.1g - what should |
| 1527 | * datagram error |
| 1528 | */ |
| 1529 | unix_state_unlock(other); |
| 1530 | sock_put(other); |
| 1531 | |
| 1532 | err = 0; |
| 1533 | unix_state_lock(sk); |
| 1534 | if (unix_peer(sk) == other) { |
| 1535 | unix_peer(sk) = NULL; |
| 1536 | unix_state_unlock(sk); |
| 1537 | |
| 1538 | unix_dgram_disconnected(sk, other); |
| 1539 | sock_put(other); |
| 1540 | err = -ECONNREFUSED; |
| 1541 | } else { |
| 1542 | unix_state_unlock(sk); |
| 1543 | } |
| 1544 | |
| 1545 | other = NULL; |
| 1546 | if (err) |
| 1547 | goto out_free; |
| 1548 | goto restart; |
| 1549 | } |
| 1550 | |
| 1551 | err = -EPIPE; |
| 1552 | if (other->sk_shutdown & RCV_SHUTDOWN) |
| 1553 | goto out_unlock; |
| 1554 | |
| 1555 | if (sk->sk_type != SOCK_SEQPACKET) { |
| 1556 | err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
| 1557 | if (err) |
| 1558 | goto out_unlock; |
| 1559 | } |
| 1560 | |
| 1561 | if (unix_peer(other) != sk && unix_recvq_full(other)) { |
| 1562 | if (!timeo) { |
| 1563 | err = -EAGAIN; |
| 1564 | goto out_unlock; |
| 1565 | } |
| 1566 | |
| 1567 | timeo = unix_wait_for_peer(other, timeo); |
| 1568 | |
| 1569 | err = sock_intr_errno(timeo); |
| 1570 | if (signal_pending(current)) |
| 1571 | goto out_free; |
| 1572 | |
| 1573 | goto restart; |
| 1574 | } |
| 1575 | |
| 1576 | if (sock_flag(other, SOCK_RCVTSTAMP)) |
| 1577 | __net_timestamp(skb); |
| 1578 | maybe_add_creds(skb, sock, other); |
| 1579 | skb_queue_tail(&other->sk_receive_queue, skb); |
| 1580 | if (max_level > unix_sk(other)->recursion_level) |
| 1581 | unix_sk(other)->recursion_level = max_level; |
| 1582 | unix_state_unlock(other); |
| 1583 | other->sk_data_ready(other, len); |
| 1584 | sock_put(other); |
| 1585 | scm_destroy(siocb->scm); |
| 1586 | return len; |
| 1587 | |
| 1588 | out_unlock: |
| 1589 | unix_state_unlock(other); |
| 1590 | out_free: |
| 1591 | kfree_skb(skb); |
| 1592 | out: |
| 1593 | if (other) |
| 1594 | sock_put(other); |
| 1595 | scm_destroy(siocb->scm); |
| 1596 | return err; |
| 1597 | } |
| 1598 | |
| 1599 | |
| 1600 | static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| 1601 | struct msghdr *msg, size_t len) |
| 1602 | { |
| 1603 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
| 1604 | struct sock *sk = sock->sk; |
| 1605 | struct sock *other = NULL; |
| 1606 | int err, size; |
| 1607 | struct sk_buff *skb; |
| 1608 | int sent = 0; |
| 1609 | struct scm_cookie tmp_scm; |
| 1610 | bool fds_sent = false; |
| 1611 | int max_level; |
| 1612 | |
| 1613 | if (NULL == siocb->scm) |
| 1614 | siocb->scm = &tmp_scm; |
| 1615 | wait_for_unix_gc(); |
| 1616 | err = scm_send(sock, msg, siocb->scm, false); |
| 1617 | if (err < 0) |
| 1618 | return err; |
| 1619 | |
| 1620 | err = -EOPNOTSUPP; |
| 1621 | if (msg->msg_flags&MSG_OOB) |
| 1622 | goto out_err; |
| 1623 | |
| 1624 | if (msg->msg_namelen) { |
| 1625 | err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; |
| 1626 | goto out_err; |
| 1627 | } else { |
| 1628 | err = -ENOTCONN; |
| 1629 | other = unix_peer(sk); |
| 1630 | if (!other) |
| 1631 | goto out_err; |
| 1632 | } |
| 1633 | |
| 1634 | if (sk->sk_shutdown & SEND_SHUTDOWN) |
| 1635 | goto pipe_err; |
| 1636 | |
| 1637 | while (sent < len) { |
| 1638 | /* |
| 1639 | * Optimisation for the fact that under 0.01% of X |
| 1640 | * messages typically need breaking up. |
| 1641 | */ |
| 1642 | |
| 1643 | size = len-sent; |
| 1644 | |
| 1645 | /* Keep two messages in the pipe so it schedules better */ |
| 1646 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
| 1647 | size = (sk->sk_sndbuf >> 1) - 64; |
| 1648 | |
| 1649 | if (size > SKB_MAX_ALLOC) |
| 1650 | size = SKB_MAX_ALLOC; |
| 1651 | |
| 1652 | /* |
| 1653 | * Grab a buffer |
| 1654 | */ |
| 1655 | |
| 1656 | skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, |
| 1657 | &err); |
| 1658 | |
| 1659 | if (skb == NULL) |
| 1660 | goto out_err; |
| 1661 | |
| 1662 | /* |
| 1663 | * If you pass two values to the sock_alloc_send_skb |
| 1664 | * it tries to grab the large buffer with GFP_NOFS |
| 1665 | * (which can fail easily), and if it fails grab the |
| 1666 | * fallback size buffer which is under a page and will |
| 1667 | * succeed. [Alan] |
| 1668 | */ |
| 1669 | size = min_t(int, size, skb_tailroom(skb)); |
| 1670 | |
| 1671 | |
| 1672 | /* Only send the fds in the first buffer */ |
| 1673 | err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); |
| 1674 | if (err < 0) { |
| 1675 | kfree_skb(skb); |
| 1676 | goto out_err; |
| 1677 | } |
| 1678 | max_level = err + 1; |
| 1679 | fds_sent = true; |
| 1680 | |
| 1681 | err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
| 1682 | if (err) { |
| 1683 | kfree_skb(skb); |
| 1684 | goto out_err; |
| 1685 | } |
| 1686 | |
| 1687 | unix_state_lock(other); |
| 1688 | |
| 1689 | if (sock_flag(other, SOCK_DEAD) || |
| 1690 | (other->sk_shutdown & RCV_SHUTDOWN)) |
| 1691 | goto pipe_err_free; |
| 1692 | |
| 1693 | maybe_add_creds(skb, sock, other); |
| 1694 | skb_queue_tail(&other->sk_receive_queue, skb); |
| 1695 | if (max_level > unix_sk(other)->recursion_level) |
| 1696 | unix_sk(other)->recursion_level = max_level; |
| 1697 | unix_state_unlock(other); |
| 1698 | other->sk_data_ready(other, size); |
| 1699 | sent += size; |
| 1700 | } |
| 1701 | |
| 1702 | scm_destroy(siocb->scm); |
| 1703 | siocb->scm = NULL; |
| 1704 | |
| 1705 | return sent; |
| 1706 | |
| 1707 | pipe_err_free: |
| 1708 | unix_state_unlock(other); |
| 1709 | kfree_skb(skb); |
| 1710 | pipe_err: |
| 1711 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
| 1712 | send_sig(SIGPIPE, current, 0); |
| 1713 | err = -EPIPE; |
| 1714 | out_err: |
| 1715 | scm_destroy(siocb->scm); |
| 1716 | siocb->scm = NULL; |
| 1717 | return sent ? : err; |
| 1718 | } |
| 1719 | |
| 1720 | static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| 1721 | struct msghdr *msg, size_t len) |
| 1722 | { |
| 1723 | int err; |
| 1724 | struct sock *sk = sock->sk; |
| 1725 | |
| 1726 | err = sock_error(sk); |
| 1727 | if (err) |
| 1728 | return err; |
| 1729 | |
| 1730 | if (sk->sk_state != TCP_ESTABLISHED) |
| 1731 | return -ENOTCONN; |
| 1732 | |
| 1733 | if (msg->msg_namelen) |
| 1734 | msg->msg_namelen = 0; |
| 1735 | |
| 1736 | return unix_dgram_sendmsg(kiocb, sock, msg, len); |
| 1737 | } |
| 1738 | |
| 1739 | static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
| 1740 | struct msghdr *msg, size_t size, |
| 1741 | int flags) |
| 1742 | { |
| 1743 | struct sock *sk = sock->sk; |
| 1744 | |
| 1745 | if (sk->sk_state != TCP_ESTABLISHED) |
| 1746 | return -ENOTCONN; |
| 1747 | |
| 1748 | return unix_dgram_recvmsg(iocb, sock, msg, size, flags); |
| 1749 | } |
| 1750 | |
| 1751 | static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
| 1752 | { |
| 1753 | struct unix_sock *u = unix_sk(sk); |
| 1754 | |
| 1755 | msg->msg_namelen = 0; |
| 1756 | if (u->addr) { |
| 1757 | msg->msg_namelen = u->addr->len; |
| 1758 | memcpy(msg->msg_name, u->addr->name, u->addr->len); |
| 1759 | } |
| 1760 | } |
| 1761 | |
| 1762 | static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, |
| 1763 | struct msghdr *msg, size_t size, |
| 1764 | int flags) |
| 1765 | { |
| 1766 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
| 1767 | struct scm_cookie tmp_scm; |
| 1768 | struct sock *sk = sock->sk; |
| 1769 | struct unix_sock *u = unix_sk(sk); |
| 1770 | int noblock = flags & MSG_DONTWAIT; |
| 1771 | struct sk_buff *skb; |
| 1772 | int err; |
| 1773 | int peeked, skip; |
| 1774 | |
| 1775 | err = -EOPNOTSUPP; |
| 1776 | if (flags&MSG_OOB) |
| 1777 | goto out; |
| 1778 | |
| 1779 | msg->msg_namelen = 0; |
| 1780 | |
| 1781 | err = mutex_lock_interruptible(&u->readlock); |
| 1782 | if (err) { |
| 1783 | err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); |
| 1784 | goto out; |
| 1785 | } |
| 1786 | |
| 1787 | skip = sk_peek_offset(sk, flags); |
| 1788 | |
| 1789 | skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); |
| 1790 | if (!skb) { |
| 1791 | unix_state_lock(sk); |
| 1792 | /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ |
| 1793 | if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && |
| 1794 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
| 1795 | err = 0; |
| 1796 | unix_state_unlock(sk); |
| 1797 | goto out_unlock; |
| 1798 | } |
| 1799 | |
| 1800 | wake_up_interruptible_sync_poll(&u->peer_wait, |
| 1801 | POLLOUT | POLLWRNORM | POLLWRBAND); |
| 1802 | |
| 1803 | if (msg->msg_name) |
| 1804 | unix_copy_addr(msg, skb->sk); |
| 1805 | |
| 1806 | if (size > skb->len - skip) |
| 1807 | size = skb->len - skip; |
| 1808 | else if (size < skb->len - skip) |
| 1809 | msg->msg_flags |= MSG_TRUNC; |
| 1810 | |
| 1811 | err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size); |
| 1812 | if (err) |
| 1813 | goto out_free; |
| 1814 | |
| 1815 | if (sock_flag(sk, SOCK_RCVTSTAMP)) |
| 1816 | __sock_recv_timestamp(msg, sk, skb); |
| 1817 | |
| 1818 | if (!siocb->scm) { |
| 1819 | siocb->scm = &tmp_scm; |
| 1820 | memset(&tmp_scm, 0, sizeof(tmp_scm)); |
| 1821 | } |
| 1822 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
| 1823 | unix_set_secdata(siocb->scm, skb); |
| 1824 | |
| 1825 | if (!(flags & MSG_PEEK)) { |
| 1826 | if (UNIXCB(skb).fp) |
| 1827 | unix_detach_fds(siocb->scm, skb); |
| 1828 | |
| 1829 | sk_peek_offset_bwd(sk, skb->len); |
| 1830 | } else { |
| 1831 | /* It is questionable: on PEEK we could: |
| 1832 | - do not return fds - good, but too simple 8) |
| 1833 | - return fds, and do not return them on read (old strategy, |
| 1834 | apparently wrong) |
| 1835 | - clone fds (I chose it for now, it is the most universal |
| 1836 | solution) |
| 1837 | |
| 1838 | POSIX 1003.1g does not actually define this clearly |
| 1839 | at all. POSIX 1003.1g doesn't define a lot of things |
| 1840 | clearly however! |
| 1841 | |
| 1842 | */ |
| 1843 | |
| 1844 | sk_peek_offset_fwd(sk, size); |
| 1845 | |
| 1846 | if (UNIXCB(skb).fp) |
| 1847 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
| 1848 | } |
| 1849 | err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
| 1850 | |
| 1851 | scm_recv(sock, msg, siocb->scm, flags); |
| 1852 | |
| 1853 | out_free: |
| 1854 | skb_free_datagram(sk, skb); |
| 1855 | out_unlock: |
| 1856 | mutex_unlock(&u->readlock); |
| 1857 | out: |
| 1858 | return err; |
| 1859 | } |
| 1860 | |
| 1861 | /* |
| 1862 | * Sleep until data has arrive. But check for races.. |
| 1863 | */ |
| 1864 | |
| 1865 | static long unix_stream_data_wait(struct sock *sk, long timeo) |
| 1866 | { |
| 1867 | DEFINE_WAIT(wait); |
| 1868 | |
| 1869 | unix_state_lock(sk); |
| 1870 | |
| 1871 | for (;;) { |
| 1872 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
| 1873 | |
| 1874 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
| 1875 | sk->sk_err || |
| 1876 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
| 1877 | signal_pending(current) || |
| 1878 | !timeo) |
| 1879 | break; |
| 1880 | |
| 1881 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
| 1882 | unix_state_unlock(sk); |
| 1883 | timeo = schedule_timeout(timeo); |
| 1884 | unix_state_lock(sk); |
| 1885 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
| 1886 | } |
| 1887 | |
| 1888 | finish_wait(sk_sleep(sk), &wait); |
| 1889 | unix_state_unlock(sk); |
| 1890 | return timeo; |
| 1891 | } |
| 1892 | |
| 1893 | |
| 1894 | |
| 1895 | static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
| 1896 | struct msghdr *msg, size_t size, |
| 1897 | int flags) |
| 1898 | { |
| 1899 | struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
| 1900 | struct scm_cookie tmp_scm; |
| 1901 | struct sock *sk = sock->sk; |
| 1902 | struct unix_sock *u = unix_sk(sk); |
| 1903 | struct sockaddr_un *sunaddr = msg->msg_name; |
| 1904 | int copied = 0; |
| 1905 | int check_creds = 0; |
| 1906 | int target; |
| 1907 | int err = 0; |
| 1908 | long timeo; |
| 1909 | int skip; |
| 1910 | |
| 1911 | err = -EINVAL; |
| 1912 | if (sk->sk_state != TCP_ESTABLISHED) |
| 1913 | goto out; |
| 1914 | |
| 1915 | err = -EOPNOTSUPP; |
| 1916 | if (flags&MSG_OOB) |
| 1917 | goto out; |
| 1918 | |
| 1919 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); |
| 1920 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); |
| 1921 | |
| 1922 | msg->msg_namelen = 0; |
| 1923 | |
| 1924 | /* Lock the socket to prevent queue disordering |
| 1925 | * while sleeps in memcpy_tomsg |
| 1926 | */ |
| 1927 | |
| 1928 | if (!siocb->scm) { |
| 1929 | siocb->scm = &tmp_scm; |
| 1930 | memset(&tmp_scm, 0, sizeof(tmp_scm)); |
| 1931 | } |
| 1932 | |
| 1933 | err = mutex_lock_interruptible(&u->readlock); |
| 1934 | if (err) { |
| 1935 | err = sock_intr_errno(timeo); |
| 1936 | goto out; |
| 1937 | } |
| 1938 | |
| 1939 | skip = sk_peek_offset(sk, flags); |
| 1940 | |
| 1941 | do { |
| 1942 | int chunk; |
| 1943 | struct sk_buff *skb; |
| 1944 | |
| 1945 | unix_state_lock(sk); |
| 1946 | skb = skb_peek(&sk->sk_receive_queue); |
| 1947 | again: |
| 1948 | if (skb == NULL) { |
| 1949 | unix_sk(sk)->recursion_level = 0; |
| 1950 | if (copied >= target) |
| 1951 | goto unlock; |
| 1952 | |
| 1953 | /* |
| 1954 | * POSIX 1003.1g mandates this order. |
| 1955 | */ |
| 1956 | |
| 1957 | err = sock_error(sk); |
| 1958 | if (err) |
| 1959 | goto unlock; |
| 1960 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
| 1961 | goto unlock; |
| 1962 | |
| 1963 | unix_state_unlock(sk); |
| 1964 | err = -EAGAIN; |
| 1965 | if (!timeo) |
| 1966 | break; |
| 1967 | mutex_unlock(&u->readlock); |
| 1968 | |
| 1969 | timeo = unix_stream_data_wait(sk, timeo); |
| 1970 | |
| 1971 | if (signal_pending(current) |
| 1972 | || mutex_lock_interruptible(&u->readlock)) { |
| 1973 | err = sock_intr_errno(timeo); |
| 1974 | goto out; |
| 1975 | } |
| 1976 | |
| 1977 | continue; |
| 1978 | unlock: |
| 1979 | unix_state_unlock(sk); |
| 1980 | break; |
| 1981 | } |
| 1982 | |
| 1983 | if (skip >= skb->len) { |
| 1984 | skip -= skb->len; |
| 1985 | skb = skb_peek_next(skb, &sk->sk_receive_queue); |
| 1986 | goto again; |
| 1987 | } |
| 1988 | |
| 1989 | unix_state_unlock(sk); |
| 1990 | |
| 1991 | if (check_creds) { |
| 1992 | /* Never glue messages from different writers */ |
| 1993 | if ((UNIXCB(skb).pid != siocb->scm->pid) || |
| 1994 | (UNIXCB(skb).cred != siocb->scm->cred)) |
| 1995 | break; |
| 1996 | } else { |
| 1997 | /* Copy credentials */ |
| 1998 | scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
| 1999 | check_creds = 1; |
| 2000 | } |
| 2001 | |
| 2002 | /* Copy address just once */ |
| 2003 | if (sunaddr) { |
| 2004 | unix_copy_addr(msg, skb->sk); |
| 2005 | sunaddr = NULL; |
| 2006 | } |
| 2007 | |
| 2008 | chunk = min_t(unsigned int, skb->len - skip, size); |
| 2009 | if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) { |
| 2010 | if (copied == 0) |
| 2011 | copied = -EFAULT; |
| 2012 | break; |
| 2013 | } |
| 2014 | copied += chunk; |
| 2015 | size -= chunk; |
| 2016 | |
| 2017 | /* Mark read part of skb as used */ |
| 2018 | if (!(flags & MSG_PEEK)) { |
| 2019 | skb_pull(skb, chunk); |
| 2020 | |
| 2021 | sk_peek_offset_bwd(sk, chunk); |
| 2022 | |
| 2023 | if (UNIXCB(skb).fp) |
| 2024 | unix_detach_fds(siocb->scm, skb); |
| 2025 | |
| 2026 | if (skb->len) |
| 2027 | break; |
| 2028 | |
| 2029 | skb_unlink(skb, &sk->sk_receive_queue); |
| 2030 | consume_skb(skb); |
| 2031 | |
| 2032 | if (siocb->scm->fp) |
| 2033 | break; |
| 2034 | } else { |
| 2035 | /* It is questionable, see note in unix_dgram_recvmsg. |
| 2036 | */ |
| 2037 | if (UNIXCB(skb).fp) |
| 2038 | siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
| 2039 | |
| 2040 | sk_peek_offset_fwd(sk, chunk); |
| 2041 | |
| 2042 | break; |
| 2043 | } |
| 2044 | } while (size); |
| 2045 | |
| 2046 | mutex_unlock(&u->readlock); |
| 2047 | scm_recv(sock, msg, siocb->scm, flags); |
| 2048 | out: |
| 2049 | return copied ? : err; |
| 2050 | } |
| 2051 | |
| 2052 | static int unix_shutdown(struct socket *sock, int mode) |
| 2053 | { |
| 2054 | struct sock *sk = sock->sk; |
| 2055 | struct sock *other; |
| 2056 | |
| 2057 | if (mode < SHUT_RD || mode > SHUT_RDWR) |
| 2058 | return -EINVAL; |
| 2059 | /* This maps: |
| 2060 | * SHUT_RD (0) -> RCV_SHUTDOWN (1) |
| 2061 | * SHUT_WR (1) -> SEND_SHUTDOWN (2) |
| 2062 | * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) |
| 2063 | */ |
| 2064 | ++mode; |
| 2065 | |
| 2066 | unix_state_lock(sk); |
| 2067 | sk->sk_shutdown |= mode; |
| 2068 | other = unix_peer(sk); |
| 2069 | if (other) |
| 2070 | sock_hold(other); |
| 2071 | unix_state_unlock(sk); |
| 2072 | sk->sk_state_change(sk); |
| 2073 | |
| 2074 | if (other && |
| 2075 | (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { |
| 2076 | |
| 2077 | int peer_mode = 0; |
| 2078 | |
| 2079 | if (mode&RCV_SHUTDOWN) |
| 2080 | peer_mode |= SEND_SHUTDOWN; |
| 2081 | if (mode&SEND_SHUTDOWN) |
| 2082 | peer_mode |= RCV_SHUTDOWN; |
| 2083 | unix_state_lock(other); |
| 2084 | other->sk_shutdown |= peer_mode; |
| 2085 | unix_state_unlock(other); |
| 2086 | other->sk_state_change(other); |
| 2087 | if (peer_mode == SHUTDOWN_MASK) |
| 2088 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); |
| 2089 | else if (peer_mode & RCV_SHUTDOWN) |
| 2090 | sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); |
| 2091 | } |
| 2092 | if (other) |
| 2093 | sock_put(other); |
| 2094 | |
| 2095 | return 0; |
| 2096 | } |
| 2097 | |
| 2098 | long unix_inq_len(struct sock *sk) |
| 2099 | { |
| 2100 | struct sk_buff *skb; |
| 2101 | long amount = 0; |
| 2102 | |
| 2103 | if (sk->sk_state == TCP_LISTEN) |
| 2104 | return -EINVAL; |
| 2105 | |
| 2106 | spin_lock(&sk->sk_receive_queue.lock); |
| 2107 | if (sk->sk_type == SOCK_STREAM || |
| 2108 | sk->sk_type == SOCK_SEQPACKET) { |
| 2109 | skb_queue_walk(&sk->sk_receive_queue, skb) |
| 2110 | amount += skb->len; |
| 2111 | } else { |
| 2112 | skb = skb_peek(&sk->sk_receive_queue); |
| 2113 | if (skb) |
| 2114 | amount = skb->len; |
| 2115 | } |
| 2116 | spin_unlock(&sk->sk_receive_queue.lock); |
| 2117 | |
| 2118 | return amount; |
| 2119 | } |
| 2120 | EXPORT_SYMBOL_GPL(unix_inq_len); |
| 2121 | |
| 2122 | long unix_outq_len(struct sock *sk) |
| 2123 | { |
| 2124 | return sk_wmem_alloc_get(sk); |
| 2125 | } |
| 2126 | EXPORT_SYMBOL_GPL(unix_outq_len); |
| 2127 | |
| 2128 | static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
| 2129 | { |
| 2130 | struct sock *sk = sock->sk; |
| 2131 | long amount = 0; |
| 2132 | int err; |
| 2133 | |
| 2134 | switch (cmd) { |
| 2135 | case SIOCOUTQ: |
| 2136 | amount = unix_outq_len(sk); |
| 2137 | err = put_user(amount, (int __user *)arg); |
| 2138 | break; |
| 2139 | case SIOCINQ: |
| 2140 | amount = unix_inq_len(sk); |
| 2141 | if (amount < 0) |
| 2142 | err = amount; |
| 2143 | else |
| 2144 | err = put_user(amount, (int __user *)arg); |
| 2145 | break; |
| 2146 | default: |
| 2147 | err = -ENOIOCTLCMD; |
| 2148 | break; |
| 2149 | } |
| 2150 | return err; |
| 2151 | } |
| 2152 | |
| 2153 | static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
| 2154 | { |
| 2155 | struct sock *sk = sock->sk; |
| 2156 | unsigned int mask; |
| 2157 | |
| 2158 | sock_poll_wait(file, sk_sleep(sk), wait); |
| 2159 | mask = 0; |
| 2160 | |
| 2161 | /* exceptional events? */ |
| 2162 | if (sk->sk_err) |
| 2163 | mask |= POLLERR; |
| 2164 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
| 2165 | mask |= POLLHUP; |
| 2166 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
| 2167 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
| 2168 | |
| 2169 | /* readable? */ |
| 2170 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
| 2171 | mask |= POLLIN | POLLRDNORM; |
| 2172 | |
| 2173 | /* Connection-based need to check for termination and startup */ |
| 2174 | if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
| 2175 | sk->sk_state == TCP_CLOSE) |
| 2176 | mask |= POLLHUP; |
| 2177 | |
| 2178 | /* |
| 2179 | * we set writable also when the other side has shut down the |
| 2180 | * connection. This prevents stuck sockets. |
| 2181 | */ |
| 2182 | if (unix_writable(sk)) |
| 2183 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
| 2184 | |
| 2185 | return mask; |
| 2186 | } |
| 2187 | |
| 2188 | static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
| 2189 | poll_table *wait) |
| 2190 | { |
| 2191 | struct sock *sk = sock->sk, *other; |
| 2192 | unsigned int mask, writable; |
| 2193 | |
| 2194 | sock_poll_wait(file, sk_sleep(sk), wait); |
| 2195 | mask = 0; |
| 2196 | |
| 2197 | /* exceptional events? */ |
| 2198 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
| 2199 | mask |= POLLERR; |
| 2200 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
| 2201 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
| 2202 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
| 2203 | mask |= POLLHUP; |
| 2204 | |
| 2205 | /* readable? */ |
| 2206 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
| 2207 | mask |= POLLIN | POLLRDNORM; |
| 2208 | |
| 2209 | /* Connection-based need to check for termination and startup */ |
| 2210 | if (sk->sk_type == SOCK_SEQPACKET) { |
| 2211 | if (sk->sk_state == TCP_CLOSE) |
| 2212 | mask |= POLLHUP; |
| 2213 | /* connection hasn't started yet? */ |
| 2214 | if (sk->sk_state == TCP_SYN_SENT) |
| 2215 | return mask; |
| 2216 | } |
| 2217 | |
| 2218 | /* No write status requested, avoid expensive OUT tests. */ |
| 2219 | if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
| 2220 | return mask; |
| 2221 | |
| 2222 | writable = unix_writable(sk); |
| 2223 | other = unix_peer_get(sk); |
| 2224 | if (other) { |
| 2225 | if (unix_peer(other) != sk) { |
| 2226 | sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); |
| 2227 | if (unix_recvq_full(other)) |
| 2228 | writable = 0; |
| 2229 | } |
| 2230 | sock_put(other); |
| 2231 | } |
| 2232 | |
| 2233 | if (writable) |
| 2234 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
| 2235 | else |
| 2236 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); |
| 2237 | |
| 2238 | return mask; |
| 2239 | } |
| 2240 | |
| 2241 | #ifdef CONFIG_PROC_FS |
| 2242 | |
| 2243 | #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1) |
| 2244 | |
| 2245 | #define get_bucket(x) ((x) >> BUCKET_SPACE) |
| 2246 | #define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1)) |
| 2247 | #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o)) |
| 2248 | |
| 2249 | static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos) |
| 2250 | { |
| 2251 | unsigned long offset = get_offset(*pos); |
| 2252 | unsigned long bucket = get_bucket(*pos); |
| 2253 | struct sock *sk; |
| 2254 | unsigned long count = 0; |
| 2255 | |
| 2256 | for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) { |
| 2257 | if (sock_net(sk) != seq_file_net(seq)) |
| 2258 | continue; |
| 2259 | if (++count == offset) |
| 2260 | break; |
| 2261 | } |
| 2262 | |
| 2263 | return sk; |
| 2264 | } |
| 2265 | |
| 2266 | static struct sock *unix_next_socket(struct seq_file *seq, |
| 2267 | struct sock *sk, |
| 2268 | loff_t *pos) |
| 2269 | { |
| 2270 | unsigned long bucket; |
| 2271 | |
| 2272 | while (sk > (struct sock *)SEQ_START_TOKEN) { |
| 2273 | sk = sk_next(sk); |
| 2274 | if (!sk) |
| 2275 | goto next_bucket; |
| 2276 | if (sock_net(sk) == seq_file_net(seq)) |
| 2277 | return sk; |
| 2278 | } |
| 2279 | |
| 2280 | do { |
| 2281 | sk = unix_from_bucket(seq, pos); |
| 2282 | if (sk) |
| 2283 | return sk; |
| 2284 | |
| 2285 | next_bucket: |
| 2286 | bucket = get_bucket(*pos) + 1; |
| 2287 | *pos = set_bucket_offset(bucket, 1); |
| 2288 | } while (bucket < ARRAY_SIZE(unix_socket_table)); |
| 2289 | |
| 2290 | return NULL; |
| 2291 | } |
| 2292 | |
| 2293 | static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
| 2294 | __acquires(unix_table_lock) |
| 2295 | { |
| 2296 | spin_lock(&unix_table_lock); |
| 2297 | |
| 2298 | if (!*pos) |
| 2299 | return SEQ_START_TOKEN; |
| 2300 | |
| 2301 | if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table)) |
| 2302 | return NULL; |
| 2303 | |
| 2304 | return unix_next_socket(seq, NULL, pos); |
| 2305 | } |
| 2306 | |
| 2307 | static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| 2308 | { |
| 2309 | ++*pos; |
| 2310 | return unix_next_socket(seq, v, pos); |
| 2311 | } |
| 2312 | |
| 2313 | static void unix_seq_stop(struct seq_file *seq, void *v) |
| 2314 | __releases(unix_table_lock) |
| 2315 | { |
| 2316 | spin_unlock(&unix_table_lock); |
| 2317 | } |
| 2318 | |
| 2319 | static int unix_seq_show(struct seq_file *seq, void *v) |
| 2320 | { |
| 2321 | |
| 2322 | if (v == SEQ_START_TOKEN) |
| 2323 | seq_puts(seq, "Num RefCount Protocol Flags Type St " |
| 2324 | "Inode Path\n"); |
| 2325 | else { |
| 2326 | struct sock *s = v; |
| 2327 | struct unix_sock *u = unix_sk(s); |
| 2328 | unix_state_lock(s); |
| 2329 | |
| 2330 | seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
| 2331 | s, |
| 2332 | atomic_read(&s->sk_refcnt), |
| 2333 | 0, |
| 2334 | s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, |
| 2335 | s->sk_type, |
| 2336 | s->sk_socket ? |
| 2337 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : |
| 2338 | (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), |
| 2339 | sock_i_ino(s)); |
| 2340 | |
| 2341 | if (u->addr) { |
| 2342 | int i, len; |
| 2343 | seq_putc(seq, ' '); |
| 2344 | |
| 2345 | i = 0; |
| 2346 | len = u->addr->len - sizeof(short); |
| 2347 | if (!UNIX_ABSTRACT(s)) |
| 2348 | len--; |
| 2349 | else { |
| 2350 | seq_putc(seq, '@'); |
| 2351 | i++; |
| 2352 | } |
| 2353 | for ( ; i < len; i++) |
| 2354 | seq_putc(seq, u->addr->name->sun_path[i]); |
| 2355 | } |
| 2356 | unix_state_unlock(s); |
| 2357 | seq_putc(seq, '\n'); |
| 2358 | } |
| 2359 | |
| 2360 | return 0; |
| 2361 | } |
| 2362 | |
| 2363 | static const struct seq_operations unix_seq_ops = { |
| 2364 | .start = unix_seq_start, |
| 2365 | .next = unix_seq_next, |
| 2366 | .stop = unix_seq_stop, |
| 2367 | .show = unix_seq_show, |
| 2368 | }; |
| 2369 | |
| 2370 | static int unix_seq_open(struct inode *inode, struct file *file) |
| 2371 | { |
| 2372 | return seq_open_net(inode, file, &unix_seq_ops, |
| 2373 | sizeof(struct seq_net_private)); |
| 2374 | } |
| 2375 | |
| 2376 | static const struct file_operations unix_seq_fops = { |
| 2377 | .owner = THIS_MODULE, |
| 2378 | .open = unix_seq_open, |
| 2379 | .read = seq_read, |
| 2380 | .llseek = seq_lseek, |
| 2381 | .release = seq_release_net, |
| 2382 | }; |
| 2383 | |
| 2384 | #endif |
| 2385 | |
| 2386 | static const struct net_proto_family unix_family_ops = { |
| 2387 | .family = PF_UNIX, |
| 2388 | .create = unix_create, |
| 2389 | .owner = THIS_MODULE, |
| 2390 | }; |
| 2391 | |
| 2392 | |
| 2393 | static int __net_init unix_net_init(struct net *net) |
| 2394 | { |
| 2395 | int error = -ENOMEM; |
| 2396 | |
| 2397 | net->unx.sysctl_max_dgram_qlen = 10; |
| 2398 | if (unix_sysctl_register(net)) |
| 2399 | goto out; |
| 2400 | |
| 2401 | #ifdef CONFIG_PROC_FS |
| 2402 | if (!proc_create("unix", 0, net->proc_net, &unix_seq_fops)) { |
| 2403 | unix_sysctl_unregister(net); |
| 2404 | goto out; |
| 2405 | } |
| 2406 | #endif |
| 2407 | error = 0; |
| 2408 | out: |
| 2409 | return error; |
| 2410 | } |
| 2411 | |
| 2412 | static void __net_exit unix_net_exit(struct net *net) |
| 2413 | { |
| 2414 | unix_sysctl_unregister(net); |
| 2415 | remove_proc_entry("unix", net->proc_net); |
| 2416 | } |
| 2417 | |
| 2418 | static struct pernet_operations unix_net_ops = { |
| 2419 | .init = unix_net_init, |
| 2420 | .exit = unix_net_exit, |
| 2421 | }; |
| 2422 | |
| 2423 | static int __init af_unix_init(void) |
| 2424 | { |
| 2425 | int rc = -1; |
| 2426 | |
| 2427 | BUILD_BUG_ON(sizeof(struct unix_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
| 2428 | |
| 2429 | rc = proto_register(&unix_proto, 1); |
| 2430 | if (rc != 0) { |
| 2431 | printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", |
| 2432 | __func__); |
| 2433 | goto out; |
| 2434 | } |
| 2435 | |
| 2436 | sock_register(&unix_family_ops); |
| 2437 | register_pernet_subsys(&unix_net_ops); |
| 2438 | out: |
| 2439 | return rc; |
| 2440 | } |
| 2441 | |
| 2442 | static void __exit af_unix_exit(void) |
| 2443 | { |
| 2444 | sock_unregister(PF_UNIX); |
| 2445 | proto_unregister(&unix_proto); |
| 2446 | unregister_pernet_subsys(&unix_net_ops); |
| 2447 | } |
| 2448 | |
| 2449 | /* Earlier than device_initcall() so that other drivers invoking |
| 2450 | request_module() don't end up in a loop when modprobe tries |
| 2451 | to use a UNIX socket. But later than subsys_initcall() because |
| 2452 | we depend on stuff initialised there */ |
| 2453 | fs_initcall(af_unix_init); |
| 2454 | module_exit(af_unix_exit); |
| 2455 | |
| 2456 | MODULE_LICENSE("GPL"); |
| 2457 | MODULE_ALIAS_NETPROTO(PF_UNIX); |