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