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