af_unix.c revision 663717f65c075eb4c6da7a123041295bd5295cc0
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 118static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; 119static DEFINE_SPINLOCK(unix_table_lock); 120static atomic_t unix_nr_socks = ATOMIC_INIT(0); 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 127static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 128{ 129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); 130} 131 132static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) 133{ 134 scm->secid = *UNIXSID(skb); 135} 136#else 137static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 138{ } 139 140static 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 150static 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 160static inline int unix_our_peer(struct sock *sk, struct sock *osk) 161{ 162 return unix_peer(osk) == sk; 163} 164 165static 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 170static 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 175static 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 187static 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 200static 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 223static void __unix_remove_socket(struct sock *sk) 224{ 225 sk_del_node_init(sk); 226} 227 228static 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 234static 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 241static 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 248static 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; 266found: 267 return s; 268} 269 270static 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 285static struct sock *unix_find_socket_byinode(struct net *net, 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 (!net_eq(sock_net(s), net)) 296 continue; 297 298 if (dentry && dentry->d_inode == i) { 299 sock_hold(s); 300 goto found; 301 } 302 } 303 s = NULL; 304found: 305 spin_unlock(&unix_table_lock); 306 return s; 307} 308 309static inline int unix_writable(struct sock *sk) 310{ 311 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; 312} 313 314static void unix_write_space(struct sock *sk) 315{ 316 read_lock(&sk->sk_callback_lock); 317 if (unix_writable(sk)) { 318 if (sk_has_sleeper(sk)) 319 wake_up_interruptible_sync(sk->sk_sleep); 320 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 321 } 322 read_unlock(&sk->sk_callback_lock); 323} 324 325/* When dgram socket disconnects (or changes its peer), we clear its receive 326 * queue of packets arrived from previous peer. First, it allows to do 327 * flow control based only on wmem_alloc; second, sk connected to peer 328 * may receive messages only from that peer. */ 329static void unix_dgram_disconnected(struct sock *sk, struct sock *other) 330{ 331 if (!skb_queue_empty(&sk->sk_receive_queue)) { 332 skb_queue_purge(&sk->sk_receive_queue); 333 wake_up_interruptible_all(&unix_sk(sk)->peer_wait); 334 335 /* If one link of bidirectional dgram pipe is disconnected, 336 * we signal error. Messages are lost. Do not make this, 337 * when peer was not connected to us. 338 */ 339 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { 340 other->sk_err = ECONNRESET; 341 other->sk_error_report(other); 342 } 343 } 344} 345 346static void unix_sock_destructor(struct sock *sk) 347{ 348 struct unix_sock *u = unix_sk(sk); 349 350 skb_queue_purge(&sk->sk_receive_queue); 351 352 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 353 WARN_ON(!sk_unhashed(sk)); 354 WARN_ON(sk->sk_socket); 355 if (!sock_flag(sk, SOCK_DEAD)) { 356 printk(KERN_INFO "Attempt to release alive unix socket: %p\n", sk); 357 return; 358 } 359 360 if (u->addr) 361 unix_release_addr(u->addr); 362 363 atomic_dec(&unix_nr_socks); 364 local_bh_disable(); 365 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 366 local_bh_enable(); 367#ifdef UNIX_REFCNT_DEBUG 368 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, 369 atomic_read(&unix_nr_socks)); 370#endif 371} 372 373static int unix_release_sock(struct sock *sk, int embrion) 374{ 375 struct unix_sock *u = unix_sk(sk); 376 struct dentry *dentry; 377 struct vfsmount *mnt; 378 struct sock *skpair; 379 struct sk_buff *skb; 380 int state; 381 382 unix_remove_socket(sk); 383 384 /* Clear state */ 385 unix_state_lock(sk); 386 sock_orphan(sk); 387 sk->sk_shutdown = SHUTDOWN_MASK; 388 dentry = u->dentry; 389 u->dentry = NULL; 390 mnt = u->mnt; 391 u->mnt = NULL; 392 state = sk->sk_state; 393 sk->sk_state = TCP_CLOSE; 394 unix_state_unlock(sk); 395 396 wake_up_interruptible_all(&u->peer_wait); 397 398 skpair = unix_peer(sk); 399 400 if (skpair != NULL) { 401 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { 402 unix_state_lock(skpair); 403 /* No more writes */ 404 skpair->sk_shutdown = SHUTDOWN_MASK; 405 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) 406 skpair->sk_err = ECONNRESET; 407 unix_state_unlock(skpair); 408 skpair->sk_state_change(skpair); 409 read_lock(&skpair->sk_callback_lock); 410 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); 411 read_unlock(&skpair->sk_callback_lock); 412 } 413 sock_put(skpair); /* It may now die */ 414 unix_peer(sk) = NULL; 415 } 416 417 /* Try to flush out this socket. Throw out buffers at least */ 418 419 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { 420 if (state == TCP_LISTEN) 421 unix_release_sock(skb->sk, 1); 422 /* passed fds are erased in the kfree_skb hook */ 423 kfree_skb(skb); 424 } 425 426 if (dentry) { 427 dput(dentry); 428 mntput(mnt); 429 } 430 431 sock_put(sk); 432 433 /* ---- Socket is dead now and most probably destroyed ---- */ 434 435 /* 436 * Fixme: BSD difference: In BSD all sockets connected to use get 437 * ECONNRESET and we die on the spot. In Linux we behave 438 * like files and pipes do and wait for the last 439 * dereference. 440 * 441 * Can't we simply set sock->err? 442 * 443 * What the above comment does talk about? --ANK(980817) 444 */ 445 446 if (unix_tot_inflight) 447 unix_gc(); /* Garbage collect fds */ 448 449 return 0; 450} 451 452static int unix_listen(struct socket *sock, int backlog) 453{ 454 int err; 455 struct sock *sk = sock->sk; 456 struct unix_sock *u = unix_sk(sk); 457 458 err = -EOPNOTSUPP; 459 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) 460 goto out; /* Only stream/seqpacket sockets accept */ 461 err = -EINVAL; 462 if (!u->addr) 463 goto out; /* No listens on an unbound socket */ 464 unix_state_lock(sk); 465 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) 466 goto out_unlock; 467 if (backlog > sk->sk_max_ack_backlog) 468 wake_up_interruptible_all(&u->peer_wait); 469 sk->sk_max_ack_backlog = backlog; 470 sk->sk_state = TCP_LISTEN; 471 /* set credentials so connect can copy them */ 472 sk->sk_peercred.pid = task_tgid_vnr(current); 473 current_euid_egid(&sk->sk_peercred.uid, &sk->sk_peercred.gid); 474 err = 0; 475 476out_unlock: 477 unix_state_unlock(sk); 478out: 479 return err; 480} 481 482static int unix_release(struct socket *); 483static int unix_bind(struct socket *, struct sockaddr *, int); 484static int unix_stream_connect(struct socket *, struct sockaddr *, 485 int addr_len, int flags); 486static int unix_socketpair(struct socket *, struct socket *); 487static int unix_accept(struct socket *, struct socket *, int); 488static int unix_getname(struct socket *, struct sockaddr *, int *, int); 489static unsigned int unix_poll(struct file *, struct socket *, poll_table *); 490static unsigned int unix_dgram_poll(struct file *, struct socket *, 491 poll_table *); 492static int unix_ioctl(struct socket *, unsigned int, unsigned long); 493static int unix_shutdown(struct socket *, int); 494static int unix_stream_sendmsg(struct kiocb *, struct socket *, 495 struct msghdr *, size_t); 496static int unix_stream_recvmsg(struct kiocb *, struct socket *, 497 struct msghdr *, size_t, int); 498static int unix_dgram_sendmsg(struct kiocb *, struct socket *, 499 struct msghdr *, size_t); 500static int unix_dgram_recvmsg(struct kiocb *, struct socket *, 501 struct msghdr *, size_t, int); 502static int unix_dgram_connect(struct socket *, struct sockaddr *, 503 int, int); 504static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, 505 struct msghdr *, size_t); 506 507static const struct proto_ops unix_stream_ops = { 508 .family = PF_UNIX, 509 .owner = THIS_MODULE, 510 .release = unix_release, 511 .bind = unix_bind, 512 .connect = unix_stream_connect, 513 .socketpair = unix_socketpair, 514 .accept = unix_accept, 515 .getname = unix_getname, 516 .poll = unix_poll, 517 .ioctl = unix_ioctl, 518 .listen = unix_listen, 519 .shutdown = unix_shutdown, 520 .setsockopt = sock_no_setsockopt, 521 .getsockopt = sock_no_getsockopt, 522 .sendmsg = unix_stream_sendmsg, 523 .recvmsg = unix_stream_recvmsg, 524 .mmap = sock_no_mmap, 525 .sendpage = sock_no_sendpage, 526}; 527 528static const struct proto_ops unix_dgram_ops = { 529 .family = PF_UNIX, 530 .owner = THIS_MODULE, 531 .release = unix_release, 532 .bind = unix_bind, 533 .connect = unix_dgram_connect, 534 .socketpair = unix_socketpair, 535 .accept = sock_no_accept, 536 .getname = unix_getname, 537 .poll = unix_dgram_poll, 538 .ioctl = unix_ioctl, 539 .listen = sock_no_listen, 540 .shutdown = unix_shutdown, 541 .setsockopt = sock_no_setsockopt, 542 .getsockopt = sock_no_getsockopt, 543 .sendmsg = unix_dgram_sendmsg, 544 .recvmsg = unix_dgram_recvmsg, 545 .mmap = sock_no_mmap, 546 .sendpage = sock_no_sendpage, 547}; 548 549static const struct proto_ops unix_seqpacket_ops = { 550 .family = PF_UNIX, 551 .owner = THIS_MODULE, 552 .release = unix_release, 553 .bind = unix_bind, 554 .connect = unix_stream_connect, 555 .socketpair = unix_socketpair, 556 .accept = unix_accept, 557 .getname = unix_getname, 558 .poll = unix_dgram_poll, 559 .ioctl = unix_ioctl, 560 .listen = unix_listen, 561 .shutdown = unix_shutdown, 562 .setsockopt = sock_no_setsockopt, 563 .getsockopt = sock_no_getsockopt, 564 .sendmsg = unix_seqpacket_sendmsg, 565 .recvmsg = unix_dgram_recvmsg, 566 .mmap = sock_no_mmap, 567 .sendpage = sock_no_sendpage, 568}; 569 570static struct proto unix_proto = { 571 .name = "UNIX", 572 .owner = THIS_MODULE, 573 .obj_size = sizeof(struct unix_sock), 574}; 575 576/* 577 * AF_UNIX sockets do not interact with hardware, hence they 578 * dont trigger interrupts - so it's safe for them to have 579 * bh-unsafe locking for their sk_receive_queue.lock. Split off 580 * this special lock-class by reinitializing the spinlock key: 581 */ 582static struct lock_class_key af_unix_sk_receive_queue_lock_key; 583 584static struct sock *unix_create1(struct net *net, struct socket *sock) 585{ 586 struct sock *sk = NULL; 587 struct unix_sock *u; 588 589 atomic_inc(&unix_nr_socks); 590 if (atomic_read(&unix_nr_socks) > 2 * get_max_files()) 591 goto out; 592 593 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); 594 if (!sk) 595 goto out; 596 597 sock_init_data(sock, sk); 598 lockdep_set_class(&sk->sk_receive_queue.lock, 599 &af_unix_sk_receive_queue_lock_key); 600 601 sk->sk_write_space = unix_write_space; 602 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; 603 sk->sk_destruct = unix_sock_destructor; 604 u = unix_sk(sk); 605 u->dentry = NULL; 606 u->mnt = NULL; 607 spin_lock_init(&u->lock); 608 atomic_long_set(&u->inflight, 0); 609 INIT_LIST_HEAD(&u->link); 610 mutex_init(&u->readlock); /* single task reading lock */ 611 init_waitqueue_head(&u->peer_wait); 612 unix_insert_socket(unix_sockets_unbound, sk); 613out: 614 if (sk == NULL) 615 atomic_dec(&unix_nr_socks); 616 else { 617 local_bh_disable(); 618 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 619 local_bh_enable(); 620 } 621 return sk; 622} 623 624static int unix_create(struct net *net, struct socket *sock, int protocol, 625 int kern) 626{ 627 if (protocol && protocol != PF_UNIX) 628 return -EPROTONOSUPPORT; 629 630 sock->state = SS_UNCONNECTED; 631 632 switch (sock->type) { 633 case SOCK_STREAM: 634 sock->ops = &unix_stream_ops; 635 break; 636 /* 637 * Believe it or not BSD has AF_UNIX, SOCK_RAW though 638 * nothing uses it. 639 */ 640 case SOCK_RAW: 641 sock->type = SOCK_DGRAM; 642 case SOCK_DGRAM: 643 sock->ops = &unix_dgram_ops; 644 break; 645 case SOCK_SEQPACKET: 646 sock->ops = &unix_seqpacket_ops; 647 break; 648 default: 649 return -ESOCKTNOSUPPORT; 650 } 651 652 return unix_create1(net, sock) ? 0 : -ENOMEM; 653} 654 655static int unix_release(struct socket *sock) 656{ 657 struct sock *sk = sock->sk; 658 659 if (!sk) 660 return 0; 661 662 sock->sk = NULL; 663 664 return unix_release_sock(sk, 0); 665} 666 667static int unix_autobind(struct socket *sock) 668{ 669 struct sock *sk = sock->sk; 670 struct net *net = sock_net(sk); 671 struct unix_sock *u = unix_sk(sk); 672 static u32 ordernum = 1; 673 struct unix_address *addr; 674 int err; 675 676 mutex_lock(&u->readlock); 677 678 err = 0; 679 if (u->addr) 680 goto out; 681 682 err = -ENOMEM; 683 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); 684 if (!addr) 685 goto out; 686 687 addr->name->sun_family = AF_UNIX; 688 atomic_set(&addr->refcnt, 1); 689 690retry: 691 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); 692 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); 693 694 spin_lock(&unix_table_lock); 695 ordernum = (ordernum+1)&0xFFFFF; 696 697 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, 698 addr->hash)) { 699 spin_unlock(&unix_table_lock); 700 /* Sanity yield. It is unusual case, but yet... */ 701 if (!(ordernum&0xFF)) 702 yield(); 703 goto retry; 704 } 705 addr->hash ^= sk->sk_type; 706 707 __unix_remove_socket(sk); 708 u->addr = addr; 709 __unix_insert_socket(&unix_socket_table[addr->hash], sk); 710 spin_unlock(&unix_table_lock); 711 err = 0; 712 713out: mutex_unlock(&u->readlock); 714 return err; 715} 716 717static struct sock *unix_find_other(struct net *net, 718 struct sockaddr_un *sunname, int len, 719 int type, unsigned hash, int *error) 720{ 721 struct sock *u; 722 struct path path; 723 int err = 0; 724 725 if (sunname->sun_path[0]) { 726 struct inode *inode; 727 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); 728 if (err) 729 goto fail; 730 inode = path.dentry->d_inode; 731 err = inode_permission(inode, MAY_WRITE); 732 if (err) 733 goto put_fail; 734 735 err = -ECONNREFUSED; 736 if (!S_ISSOCK(inode->i_mode)) 737 goto put_fail; 738 u = unix_find_socket_byinode(net, inode); 739 if (!u) 740 goto put_fail; 741 742 if (u->sk_type == type) 743 touch_atime(path.mnt, path.dentry); 744 745 path_put(&path); 746 747 err = -EPROTOTYPE; 748 if (u->sk_type != type) { 749 sock_put(u); 750 goto fail; 751 } 752 } else { 753 err = -ECONNREFUSED; 754 u = unix_find_socket_byname(net, sunname, len, type, hash); 755 if (u) { 756 struct dentry *dentry; 757 dentry = unix_sk(u)->dentry; 758 if (dentry) 759 touch_atime(unix_sk(u)->mnt, dentry); 760 } else 761 goto fail; 762 } 763 return u; 764 765put_fail: 766 path_put(&path); 767fail: 768 *error = err; 769 return NULL; 770} 771 772 773static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 774{ 775 struct sock *sk = sock->sk; 776 struct net *net = sock_net(sk); 777 struct unix_sock *u = unix_sk(sk); 778 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 779 struct dentry *dentry = NULL; 780 struct nameidata nd; 781 int err; 782 unsigned hash; 783 struct unix_address *addr; 784 struct hlist_head *list; 785 786 err = -EINVAL; 787 if (sunaddr->sun_family != AF_UNIX) 788 goto out; 789 790 if (addr_len == sizeof(short)) { 791 err = unix_autobind(sock); 792 goto out; 793 } 794 795 err = unix_mkname(sunaddr, addr_len, &hash); 796 if (err < 0) 797 goto out; 798 addr_len = err; 799 800 mutex_lock(&u->readlock); 801 802 err = -EINVAL; 803 if (u->addr) 804 goto out_up; 805 806 err = -ENOMEM; 807 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); 808 if (!addr) 809 goto out_up; 810 811 memcpy(addr->name, sunaddr, addr_len); 812 addr->len = addr_len; 813 addr->hash = hash ^ sk->sk_type; 814 atomic_set(&addr->refcnt, 1); 815 816 if (sunaddr->sun_path[0]) { 817 unsigned int mode; 818 err = 0; 819 /* 820 * Get the parent directory, calculate the hash for last 821 * component. 822 */ 823 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); 824 if (err) 825 goto out_mknod_parent; 826 827 dentry = lookup_create(&nd, 0); 828 err = PTR_ERR(dentry); 829 if (IS_ERR(dentry)) 830 goto out_mknod_unlock; 831 832 /* 833 * All right, let's create it. 834 */ 835 mode = S_IFSOCK | 836 (SOCK_INODE(sock)->i_mode & ~current_umask()); 837 err = mnt_want_write(nd.path.mnt); 838 if (err) 839 goto out_mknod_dput; 840 err = security_path_mknod(&nd.path, dentry, mode, 0); 841 if (err) 842 goto out_mknod_drop_write; 843 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); 844out_mknod_drop_write: 845 mnt_drop_write(nd.path.mnt); 846 if (err) 847 goto out_mknod_dput; 848 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 849 dput(nd.path.dentry); 850 nd.path.dentry = dentry; 851 852 addr->hash = UNIX_HASH_SIZE; 853 } 854 855 spin_lock(&unix_table_lock); 856 857 if (!sunaddr->sun_path[0]) { 858 err = -EADDRINUSE; 859 if (__unix_find_socket_byname(net, sunaddr, addr_len, 860 sk->sk_type, hash)) { 861 unix_release_addr(addr); 862 goto out_unlock; 863 } 864 865 list = &unix_socket_table[addr->hash]; 866 } else { 867 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; 868 u->dentry = nd.path.dentry; 869 u->mnt = nd.path.mnt; 870 } 871 872 err = 0; 873 __unix_remove_socket(sk); 874 u->addr = addr; 875 __unix_insert_socket(list, sk); 876 877out_unlock: 878 spin_unlock(&unix_table_lock); 879out_up: 880 mutex_unlock(&u->readlock); 881out: 882 return err; 883 884out_mknod_dput: 885 dput(dentry); 886out_mknod_unlock: 887 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 888 path_put(&nd.path); 889out_mknod_parent: 890 if (err == -EEXIST) 891 err = -EADDRINUSE; 892 unix_release_addr(addr); 893 goto out_up; 894} 895 896static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) 897{ 898 if (unlikely(sk1 == sk2) || !sk2) { 899 unix_state_lock(sk1); 900 return; 901 } 902 if (sk1 < sk2) { 903 unix_state_lock(sk1); 904 unix_state_lock_nested(sk2); 905 } else { 906 unix_state_lock(sk2); 907 unix_state_lock_nested(sk1); 908 } 909} 910 911static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) 912{ 913 if (unlikely(sk1 == sk2) || !sk2) { 914 unix_state_unlock(sk1); 915 return; 916 } 917 unix_state_unlock(sk1); 918 unix_state_unlock(sk2); 919} 920 921static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 922 int alen, int flags) 923{ 924 struct sock *sk = sock->sk; 925 struct net *net = sock_net(sk); 926 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; 927 struct sock *other; 928 unsigned hash; 929 int err; 930 931 if (addr->sa_family != AF_UNSPEC) { 932 err = unix_mkname(sunaddr, alen, &hash); 933 if (err < 0) 934 goto out; 935 alen = err; 936 937 if (test_bit(SOCK_PASSCRED, &sock->flags) && 938 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) 939 goto out; 940 941restart: 942 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); 943 if (!other) 944 goto out; 945 946 unix_state_double_lock(sk, other); 947 948 /* Apparently VFS overslept socket death. Retry. */ 949 if (sock_flag(other, SOCK_DEAD)) { 950 unix_state_double_unlock(sk, other); 951 sock_put(other); 952 goto restart; 953 } 954 955 err = -EPERM; 956 if (!unix_may_send(sk, other)) 957 goto out_unlock; 958 959 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 960 if (err) 961 goto out_unlock; 962 963 } else { 964 /* 965 * 1003.1g breaking connected state with AF_UNSPEC 966 */ 967 other = NULL; 968 unix_state_double_lock(sk, other); 969 } 970 971 /* 972 * If it was connected, reconnect. 973 */ 974 if (unix_peer(sk)) { 975 struct sock *old_peer = unix_peer(sk); 976 unix_peer(sk) = other; 977 unix_state_double_unlock(sk, other); 978 979 if (other != old_peer) 980 unix_dgram_disconnected(sk, old_peer); 981 sock_put(old_peer); 982 } else { 983 unix_peer(sk) = other; 984 unix_state_double_unlock(sk, other); 985 } 986 return 0; 987 988out_unlock: 989 unix_state_double_unlock(sk, other); 990 sock_put(other); 991out: 992 return err; 993} 994 995static long unix_wait_for_peer(struct sock *other, long timeo) 996{ 997 struct unix_sock *u = unix_sk(other); 998 int sched; 999 DEFINE_WAIT(wait); 1000 1001 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); 1002 1003 sched = !sock_flag(other, SOCK_DEAD) && 1004 !(other->sk_shutdown & RCV_SHUTDOWN) && 1005 unix_recvq_full(other); 1006 1007 unix_state_unlock(other); 1008 1009 if (sched) 1010 timeo = schedule_timeout(timeo); 1011 1012 finish_wait(&u->peer_wait, &wait); 1013 return timeo; 1014} 1015 1016static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, 1017 int addr_len, int flags) 1018{ 1019 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 1020 struct sock *sk = sock->sk; 1021 struct net *net = sock_net(sk); 1022 struct unix_sock *u = unix_sk(sk), *newu, *otheru; 1023 struct sock *newsk = NULL; 1024 struct sock *other = NULL; 1025 struct sk_buff *skb = NULL; 1026 unsigned hash; 1027 int st; 1028 int err; 1029 long timeo; 1030 1031 err = unix_mkname(sunaddr, addr_len, &hash); 1032 if (err < 0) 1033 goto out; 1034 addr_len = err; 1035 1036 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && 1037 (err = unix_autobind(sock)) != 0) 1038 goto out; 1039 1040 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 1041 1042 /* First of all allocate resources. 1043 If we will make it after state is locked, 1044 we will have to recheck all again in any case. 1045 */ 1046 1047 err = -ENOMEM; 1048 1049 /* create new sock for complete connection */ 1050 newsk = unix_create1(sock_net(sk), NULL); 1051 if (newsk == NULL) 1052 goto out; 1053 1054 /* Allocate skb for sending to listening sock */ 1055 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); 1056 if (skb == NULL) 1057 goto out; 1058 1059restart: 1060 /* Find listening sock. */ 1061 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); 1062 if (!other) 1063 goto out; 1064 1065 /* Latch state of peer */ 1066 unix_state_lock(other); 1067 1068 /* Apparently VFS overslept socket death. Retry. */ 1069 if (sock_flag(other, SOCK_DEAD)) { 1070 unix_state_unlock(other); 1071 sock_put(other); 1072 goto restart; 1073 } 1074 1075 err = -ECONNREFUSED; 1076 if (other->sk_state != TCP_LISTEN) 1077 goto out_unlock; 1078 if (other->sk_shutdown & RCV_SHUTDOWN) 1079 goto out_unlock; 1080 1081 if (unix_recvq_full(other)) { 1082 err = -EAGAIN; 1083 if (!timeo) 1084 goto out_unlock; 1085 1086 timeo = unix_wait_for_peer(other, timeo); 1087 1088 err = sock_intr_errno(timeo); 1089 if (signal_pending(current)) 1090 goto out; 1091 sock_put(other); 1092 goto restart; 1093 } 1094 1095 /* Latch our state. 1096 1097 It is tricky place. We need to grab write lock and cannot 1098 drop lock on peer. It is dangerous because deadlock is 1099 possible. Connect to self case and simultaneous 1100 attempt to connect are eliminated by checking socket 1101 state. other is TCP_LISTEN, if sk is TCP_LISTEN we 1102 check this before attempt to grab lock. 1103 1104 Well, and we have to recheck the state after socket locked. 1105 */ 1106 st = sk->sk_state; 1107 1108 switch (st) { 1109 case TCP_CLOSE: 1110 /* This is ok... continue with connect */ 1111 break; 1112 case TCP_ESTABLISHED: 1113 /* Socket is already connected */ 1114 err = -EISCONN; 1115 goto out_unlock; 1116 default: 1117 err = -EINVAL; 1118 goto out_unlock; 1119 } 1120 1121 unix_state_lock_nested(sk); 1122 1123 if (sk->sk_state != st) { 1124 unix_state_unlock(sk); 1125 unix_state_unlock(other); 1126 sock_put(other); 1127 goto restart; 1128 } 1129 1130 err = security_unix_stream_connect(sock, other->sk_socket, newsk); 1131 if (err) { 1132 unix_state_unlock(sk); 1133 goto out_unlock; 1134 } 1135 1136 /* The way is open! Fastly set all the necessary fields... */ 1137 1138 sock_hold(sk); 1139 unix_peer(newsk) = sk; 1140 newsk->sk_state = TCP_ESTABLISHED; 1141 newsk->sk_type = sk->sk_type; 1142 newsk->sk_peercred.pid = task_tgid_vnr(current); 1143 current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid); 1144 newu = unix_sk(newsk); 1145 newsk->sk_sleep = &newu->peer_wait; 1146 otheru = unix_sk(other); 1147 1148 /* copy address information from listening to new sock*/ 1149 if (otheru->addr) { 1150 atomic_inc(&otheru->addr->refcnt); 1151 newu->addr = otheru->addr; 1152 } 1153 if (otheru->dentry) { 1154 newu->dentry = dget(otheru->dentry); 1155 newu->mnt = mntget(otheru->mnt); 1156 } 1157 1158 /* Set credentials */ 1159 sk->sk_peercred = other->sk_peercred; 1160 1161 sock->state = SS_CONNECTED; 1162 sk->sk_state = TCP_ESTABLISHED; 1163 sock_hold(newsk); 1164 1165 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ 1166 unix_peer(sk) = newsk; 1167 1168 unix_state_unlock(sk); 1169 1170 /* take ten and and send info to listening sock */ 1171 spin_lock(&other->sk_receive_queue.lock); 1172 __skb_queue_tail(&other->sk_receive_queue, skb); 1173 spin_unlock(&other->sk_receive_queue.lock); 1174 unix_state_unlock(other); 1175 other->sk_data_ready(other, 0); 1176 sock_put(other); 1177 return 0; 1178 1179out_unlock: 1180 if (other) 1181 unix_state_unlock(other); 1182 1183out: 1184 kfree_skb(skb); 1185 if (newsk) 1186 unix_release_sock(newsk, 0); 1187 if (other) 1188 sock_put(other); 1189 return err; 1190} 1191 1192static int unix_socketpair(struct socket *socka, struct socket *sockb) 1193{ 1194 struct sock *ska = socka->sk, *skb = sockb->sk; 1195 1196 /* Join our sockets back to back */ 1197 sock_hold(ska); 1198 sock_hold(skb); 1199 unix_peer(ska) = skb; 1200 unix_peer(skb) = ska; 1201 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current); 1202 current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid); 1203 ska->sk_peercred.uid = skb->sk_peercred.uid; 1204 ska->sk_peercred.gid = skb->sk_peercred.gid; 1205 1206 if (ska->sk_type != SOCK_DGRAM) { 1207 ska->sk_state = TCP_ESTABLISHED; 1208 skb->sk_state = TCP_ESTABLISHED; 1209 socka->state = SS_CONNECTED; 1210 sockb->state = SS_CONNECTED; 1211 } 1212 return 0; 1213} 1214 1215static int unix_accept(struct socket *sock, struct socket *newsock, int flags) 1216{ 1217 struct sock *sk = sock->sk; 1218 struct sock *tsk; 1219 struct sk_buff *skb; 1220 int err; 1221 1222 err = -EOPNOTSUPP; 1223 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) 1224 goto out; 1225 1226 err = -EINVAL; 1227 if (sk->sk_state != TCP_LISTEN) 1228 goto out; 1229 1230 /* If socket state is TCP_LISTEN it cannot change (for now...), 1231 * so that no locks are necessary. 1232 */ 1233 1234 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); 1235 if (!skb) { 1236 /* This means receive shutdown. */ 1237 if (err == 0) 1238 err = -EINVAL; 1239 goto out; 1240 } 1241 1242 tsk = skb->sk; 1243 skb_free_datagram(sk, skb); 1244 wake_up_interruptible(&unix_sk(sk)->peer_wait); 1245 1246 /* attach accepted sock to socket */ 1247 unix_state_lock(tsk); 1248 newsock->state = SS_CONNECTED; 1249 sock_graft(tsk, newsock); 1250 unix_state_unlock(tsk); 1251 return 0; 1252 1253out: 1254 return err; 1255} 1256 1257 1258static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) 1259{ 1260 struct sock *sk = sock->sk; 1261 struct unix_sock *u; 1262 DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); 1263 int err = 0; 1264 1265 if (peer) { 1266 sk = unix_peer_get(sk); 1267 1268 err = -ENOTCONN; 1269 if (!sk) 1270 goto out; 1271 err = 0; 1272 } else { 1273 sock_hold(sk); 1274 } 1275 1276 u = unix_sk(sk); 1277 unix_state_lock(sk); 1278 if (!u->addr) { 1279 sunaddr->sun_family = AF_UNIX; 1280 sunaddr->sun_path[0] = 0; 1281 *uaddr_len = sizeof(short); 1282 } else { 1283 struct unix_address *addr = u->addr; 1284 1285 *uaddr_len = addr->len; 1286 memcpy(sunaddr, addr->name, *uaddr_len); 1287 } 1288 unix_state_unlock(sk); 1289 sock_put(sk); 1290out: 1291 return err; 1292} 1293 1294static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1295{ 1296 int i; 1297 1298 scm->fp = UNIXCB(skb).fp; 1299 skb->destructor = sock_wfree; 1300 UNIXCB(skb).fp = NULL; 1301 1302 for (i = scm->fp->count-1; i >= 0; i--) 1303 unix_notinflight(scm->fp->fp[i]); 1304} 1305 1306static void unix_destruct_fds(struct sk_buff *skb) 1307{ 1308 struct scm_cookie scm; 1309 memset(&scm, 0, sizeof(scm)); 1310 unix_detach_fds(&scm, skb); 1311 1312 /* Alas, it calls VFS */ 1313 /* So fscking what? fput() had been SMP-safe since the last Summer */ 1314 scm_destroy(&scm); 1315 sock_wfree(skb); 1316} 1317 1318static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1319{ 1320 int i; 1321 1322 /* 1323 * Need to duplicate file references for the sake of garbage 1324 * collection. Otherwise a socket in the fps might become a 1325 * candidate for GC while the skb is not yet queued. 1326 */ 1327 UNIXCB(skb).fp = scm_fp_dup(scm->fp); 1328 if (!UNIXCB(skb).fp) 1329 return -ENOMEM; 1330 1331 for (i = scm->fp->count-1; i >= 0; i--) 1332 unix_inflight(scm->fp->fp[i]); 1333 skb->destructor = unix_destruct_fds; 1334 return 0; 1335} 1336 1337/* 1338 * Send AF_UNIX data. 1339 */ 1340 1341static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 1342 struct msghdr *msg, size_t len) 1343{ 1344 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1345 struct sock *sk = sock->sk; 1346 struct net *net = sock_net(sk); 1347 struct unix_sock *u = unix_sk(sk); 1348 struct sockaddr_un *sunaddr = msg->msg_name; 1349 struct sock *other = NULL; 1350 int namelen = 0; /* fake GCC */ 1351 int err; 1352 unsigned hash; 1353 struct sk_buff *skb; 1354 long timeo; 1355 struct scm_cookie tmp_scm; 1356 1357 if (NULL == siocb->scm) 1358 siocb->scm = &tmp_scm; 1359 wait_for_unix_gc(); 1360 err = scm_send(sock, msg, siocb->scm); 1361 if (err < 0) 1362 return err; 1363 1364 err = -EOPNOTSUPP; 1365 if (msg->msg_flags&MSG_OOB) 1366 goto out; 1367 1368 if (msg->msg_namelen) { 1369 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1370 if (err < 0) 1371 goto out; 1372 namelen = err; 1373 } else { 1374 sunaddr = NULL; 1375 err = -ENOTCONN; 1376 other = unix_peer_get(sk); 1377 if (!other) 1378 goto out; 1379 } 1380 1381 if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr 1382 && (err = unix_autobind(sock)) != 0) 1383 goto out; 1384 1385 err = -EMSGSIZE; 1386 if (len > sk->sk_sndbuf - 32) 1387 goto out; 1388 1389 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1390 if (skb == NULL) 1391 goto out; 1392 1393 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1394 if (siocb->scm->fp) { 1395 err = unix_attach_fds(siocb->scm, skb); 1396 if (err) 1397 goto out_free; 1398 } 1399 unix_get_secdata(siocb->scm, skb); 1400 1401 skb_reset_transport_header(skb); 1402 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1403 if (err) 1404 goto out_free; 1405 1406 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1407 1408restart: 1409 if (!other) { 1410 err = -ECONNRESET; 1411 if (sunaddr == NULL) 1412 goto out_free; 1413 1414 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1415 hash, &err); 1416 if (other == NULL) 1417 goto out_free; 1418 } 1419 1420 unix_state_lock(other); 1421 err = -EPERM; 1422 if (!unix_may_send(sk, other)) 1423 goto out_unlock; 1424 1425 if (sock_flag(other, SOCK_DEAD)) { 1426 /* 1427 * Check with 1003.1g - what should 1428 * datagram error 1429 */ 1430 unix_state_unlock(other); 1431 sock_put(other); 1432 1433 err = 0; 1434 unix_state_lock(sk); 1435 if (unix_peer(sk) == other) { 1436 unix_peer(sk) = NULL; 1437 unix_state_unlock(sk); 1438 1439 unix_dgram_disconnected(sk, other); 1440 sock_put(other); 1441 err = -ECONNREFUSED; 1442 } else { 1443 unix_state_unlock(sk); 1444 } 1445 1446 other = NULL; 1447 if (err) 1448 goto out_free; 1449 goto restart; 1450 } 1451 1452 err = -EPIPE; 1453 if (other->sk_shutdown & RCV_SHUTDOWN) 1454 goto out_unlock; 1455 1456 if (sk->sk_type != SOCK_SEQPACKET) { 1457 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1458 if (err) 1459 goto out_unlock; 1460 } 1461 1462 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1463 if (!timeo) { 1464 err = -EAGAIN; 1465 goto out_unlock; 1466 } 1467 1468 timeo = unix_wait_for_peer(other, timeo); 1469 1470 err = sock_intr_errno(timeo); 1471 if (signal_pending(current)) 1472 goto out_free; 1473 1474 goto restart; 1475 } 1476 1477 skb_queue_tail(&other->sk_receive_queue, skb); 1478 unix_state_unlock(other); 1479 other->sk_data_ready(other, len); 1480 sock_put(other); 1481 scm_destroy(siocb->scm); 1482 return len; 1483 1484out_unlock: 1485 unix_state_unlock(other); 1486out_free: 1487 kfree_skb(skb); 1488out: 1489 if (other) 1490 sock_put(other); 1491 scm_destroy(siocb->scm); 1492 return err; 1493} 1494 1495 1496static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1497 struct msghdr *msg, size_t len) 1498{ 1499 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1500 struct sock *sk = sock->sk; 1501 struct sock *other = NULL; 1502 struct sockaddr_un *sunaddr = msg->msg_name; 1503 int err, size; 1504 struct sk_buff *skb; 1505 int sent = 0; 1506 struct scm_cookie tmp_scm; 1507 bool fds_sent = false; 1508 1509 if (NULL == siocb->scm) 1510 siocb->scm = &tmp_scm; 1511 wait_for_unix_gc(); 1512 err = scm_send(sock, msg, siocb->scm); 1513 if (err < 0) 1514 return err; 1515 1516 err = -EOPNOTSUPP; 1517 if (msg->msg_flags&MSG_OOB) 1518 goto out_err; 1519 1520 if (msg->msg_namelen) { 1521 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1522 goto out_err; 1523 } else { 1524 sunaddr = NULL; 1525 err = -ENOTCONN; 1526 other = unix_peer(sk); 1527 if (!other) 1528 goto out_err; 1529 } 1530 1531 if (sk->sk_shutdown & SEND_SHUTDOWN) 1532 goto pipe_err; 1533 1534 while (sent < len) { 1535 /* 1536 * Optimisation for the fact that under 0.01% of X 1537 * messages typically need breaking up. 1538 */ 1539 1540 size = len-sent; 1541 1542 /* Keep two messages in the pipe so it schedules better */ 1543 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1544 size = (sk->sk_sndbuf >> 1) - 64; 1545 1546 if (size > SKB_MAX_ALLOC) 1547 size = SKB_MAX_ALLOC; 1548 1549 /* 1550 * Grab a buffer 1551 */ 1552 1553 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, 1554 &err); 1555 1556 if (skb == NULL) 1557 goto out_err; 1558 1559 /* 1560 * If you pass two values to the sock_alloc_send_skb 1561 * it tries to grab the large buffer with GFP_NOFS 1562 * (which can fail easily), and if it fails grab the 1563 * fallback size buffer which is under a page and will 1564 * succeed. [Alan] 1565 */ 1566 size = min_t(int, size, skb_tailroom(skb)); 1567 1568 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1569 /* Only send the fds in the first buffer */ 1570 if (siocb->scm->fp && !fds_sent) { 1571 err = unix_attach_fds(siocb->scm, skb); 1572 if (err) { 1573 kfree_skb(skb); 1574 goto out_err; 1575 } 1576 fds_sent = true; 1577 } 1578 1579 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 1580 if (err) { 1581 kfree_skb(skb); 1582 goto out_err; 1583 } 1584 1585 unix_state_lock(other); 1586 1587 if (sock_flag(other, SOCK_DEAD) || 1588 (other->sk_shutdown & RCV_SHUTDOWN)) 1589 goto pipe_err_free; 1590 1591 skb_queue_tail(&other->sk_receive_queue, skb); 1592 unix_state_unlock(other); 1593 other->sk_data_ready(other, size); 1594 sent += size; 1595 } 1596 1597 scm_destroy(siocb->scm); 1598 siocb->scm = NULL; 1599 1600 return sent; 1601 1602pipe_err_free: 1603 unix_state_unlock(other); 1604 kfree_skb(skb); 1605pipe_err: 1606 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1607 send_sig(SIGPIPE, current, 0); 1608 err = -EPIPE; 1609out_err: 1610 scm_destroy(siocb->scm); 1611 siocb->scm = NULL; 1612 return sent ? : err; 1613} 1614 1615static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1616 struct msghdr *msg, size_t len) 1617{ 1618 int err; 1619 struct sock *sk = sock->sk; 1620 1621 err = sock_error(sk); 1622 if (err) 1623 return err; 1624 1625 if (sk->sk_state != TCP_ESTABLISHED) 1626 return -ENOTCONN; 1627 1628 if (msg->msg_namelen) 1629 msg->msg_namelen = 0; 1630 1631 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1632} 1633 1634static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1635{ 1636 struct unix_sock *u = unix_sk(sk); 1637 1638 msg->msg_namelen = 0; 1639 if (u->addr) { 1640 msg->msg_namelen = u->addr->len; 1641 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1642 } 1643} 1644 1645static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1646 struct msghdr *msg, size_t size, 1647 int flags) 1648{ 1649 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1650 struct scm_cookie tmp_scm; 1651 struct sock *sk = sock->sk; 1652 struct unix_sock *u = unix_sk(sk); 1653 int noblock = flags & MSG_DONTWAIT; 1654 struct sk_buff *skb; 1655 int err; 1656 1657 err = -EOPNOTSUPP; 1658 if (flags&MSG_OOB) 1659 goto out; 1660 1661 msg->msg_namelen = 0; 1662 1663 mutex_lock(&u->readlock); 1664 1665 skb = skb_recv_datagram(sk, flags, noblock, &err); 1666 if (!skb) { 1667 unix_state_lock(sk); 1668 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1669 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1670 (sk->sk_shutdown & RCV_SHUTDOWN)) 1671 err = 0; 1672 unix_state_unlock(sk); 1673 goto out_unlock; 1674 } 1675 1676 wake_up_interruptible_sync(&u->peer_wait); 1677 1678 if (msg->msg_name) 1679 unix_copy_addr(msg, skb->sk); 1680 1681 if (size > skb->len) 1682 size = skb->len; 1683 else if (size < skb->len) 1684 msg->msg_flags |= MSG_TRUNC; 1685 1686 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1687 if (err) 1688 goto out_free; 1689 1690 if (!siocb->scm) { 1691 siocb->scm = &tmp_scm; 1692 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1693 } 1694 siocb->scm->creds = *UNIXCREDS(skb); 1695 unix_set_secdata(siocb->scm, skb); 1696 1697 if (!(flags & MSG_PEEK)) { 1698 if (UNIXCB(skb).fp) 1699 unix_detach_fds(siocb->scm, skb); 1700 } else { 1701 /* It is questionable: on PEEK we could: 1702 - do not return fds - good, but too simple 8) 1703 - return fds, and do not return them on read (old strategy, 1704 apparently wrong) 1705 - clone fds (I chose it for now, it is the most universal 1706 solution) 1707 1708 POSIX 1003.1g does not actually define this clearly 1709 at all. POSIX 1003.1g doesn't define a lot of things 1710 clearly however! 1711 1712 */ 1713 if (UNIXCB(skb).fp) 1714 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1715 } 1716 err = size; 1717 1718 scm_recv(sock, msg, siocb->scm, flags); 1719 1720out_free: 1721 skb_free_datagram(sk, skb); 1722out_unlock: 1723 mutex_unlock(&u->readlock); 1724out: 1725 return err; 1726} 1727 1728/* 1729 * Sleep until data has arrive. But check for races.. 1730 */ 1731 1732static long unix_stream_data_wait(struct sock *sk, long timeo) 1733{ 1734 DEFINE_WAIT(wait); 1735 1736 unix_state_lock(sk); 1737 1738 for (;;) { 1739 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1740 1741 if (!skb_queue_empty(&sk->sk_receive_queue) || 1742 sk->sk_err || 1743 (sk->sk_shutdown & RCV_SHUTDOWN) || 1744 signal_pending(current) || 1745 !timeo) 1746 break; 1747 1748 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1749 unix_state_unlock(sk); 1750 timeo = schedule_timeout(timeo); 1751 unix_state_lock(sk); 1752 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1753 } 1754 1755 finish_wait(sk->sk_sleep, &wait); 1756 unix_state_unlock(sk); 1757 return timeo; 1758} 1759 1760 1761 1762static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1763 struct msghdr *msg, size_t size, 1764 int flags) 1765{ 1766 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1767 struct scm_cookie tmp_scm; 1768 struct sock *sk = sock->sk; 1769 struct unix_sock *u = unix_sk(sk); 1770 struct sockaddr_un *sunaddr = msg->msg_name; 1771 int copied = 0; 1772 int check_creds = 0; 1773 int target; 1774 int err = 0; 1775 long timeo; 1776 1777 err = -EINVAL; 1778 if (sk->sk_state != TCP_ESTABLISHED) 1779 goto out; 1780 1781 err = -EOPNOTSUPP; 1782 if (flags&MSG_OOB) 1783 goto out; 1784 1785 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1786 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1787 1788 msg->msg_namelen = 0; 1789 1790 /* Lock the socket to prevent queue disordering 1791 * while sleeps in memcpy_tomsg 1792 */ 1793 1794 if (!siocb->scm) { 1795 siocb->scm = &tmp_scm; 1796 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1797 } 1798 1799 mutex_lock(&u->readlock); 1800 1801 do { 1802 int chunk; 1803 struct sk_buff *skb; 1804 1805 unix_state_lock(sk); 1806 skb = skb_dequeue(&sk->sk_receive_queue); 1807 if (skb == NULL) { 1808 if (copied >= target) 1809 goto unlock; 1810 1811 /* 1812 * POSIX 1003.1g mandates this order. 1813 */ 1814 1815 err = sock_error(sk); 1816 if (err) 1817 goto unlock; 1818 if (sk->sk_shutdown & RCV_SHUTDOWN) 1819 goto unlock; 1820 1821 unix_state_unlock(sk); 1822 err = -EAGAIN; 1823 if (!timeo) 1824 break; 1825 mutex_unlock(&u->readlock); 1826 1827 timeo = unix_stream_data_wait(sk, timeo); 1828 1829 if (signal_pending(current)) { 1830 err = sock_intr_errno(timeo); 1831 goto out; 1832 } 1833 mutex_lock(&u->readlock); 1834 continue; 1835 unlock: 1836 unix_state_unlock(sk); 1837 break; 1838 } 1839 unix_state_unlock(sk); 1840 1841 if (check_creds) { 1842 /* Never glue messages from different writers */ 1843 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, 1844 sizeof(siocb->scm->creds)) != 0) { 1845 skb_queue_head(&sk->sk_receive_queue, skb); 1846 break; 1847 } 1848 } else { 1849 /* Copy credentials */ 1850 siocb->scm->creds = *UNIXCREDS(skb); 1851 check_creds = 1; 1852 } 1853 1854 /* Copy address just once */ 1855 if (sunaddr) { 1856 unix_copy_addr(msg, skb->sk); 1857 sunaddr = NULL; 1858 } 1859 1860 chunk = min_t(unsigned int, skb->len, size); 1861 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1862 skb_queue_head(&sk->sk_receive_queue, skb); 1863 if (copied == 0) 1864 copied = -EFAULT; 1865 break; 1866 } 1867 copied += chunk; 1868 size -= chunk; 1869 1870 /* Mark read part of skb as used */ 1871 if (!(flags & MSG_PEEK)) { 1872 skb_pull(skb, chunk); 1873 1874 if (UNIXCB(skb).fp) 1875 unix_detach_fds(siocb->scm, skb); 1876 1877 /* put the skb back if we didn't use it up.. */ 1878 if (skb->len) { 1879 skb_queue_head(&sk->sk_receive_queue, skb); 1880 break; 1881 } 1882 1883 kfree_skb(skb); 1884 1885 if (siocb->scm->fp) 1886 break; 1887 } else { 1888 /* It is questionable, see note in unix_dgram_recvmsg. 1889 */ 1890 if (UNIXCB(skb).fp) 1891 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1892 1893 /* put message back and return */ 1894 skb_queue_head(&sk->sk_receive_queue, skb); 1895 break; 1896 } 1897 } while (size); 1898 1899 mutex_unlock(&u->readlock); 1900 scm_recv(sock, msg, siocb->scm, flags); 1901out: 1902 return copied ? : err; 1903} 1904 1905static int unix_shutdown(struct socket *sock, int mode) 1906{ 1907 struct sock *sk = sock->sk; 1908 struct sock *other; 1909 1910 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1911 1912 if (mode) { 1913 unix_state_lock(sk); 1914 sk->sk_shutdown |= mode; 1915 other = unix_peer(sk); 1916 if (other) 1917 sock_hold(other); 1918 unix_state_unlock(sk); 1919 sk->sk_state_change(sk); 1920 1921 if (other && 1922 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1923 1924 int peer_mode = 0; 1925 1926 if (mode&RCV_SHUTDOWN) 1927 peer_mode |= SEND_SHUTDOWN; 1928 if (mode&SEND_SHUTDOWN) 1929 peer_mode |= RCV_SHUTDOWN; 1930 unix_state_lock(other); 1931 other->sk_shutdown |= peer_mode; 1932 unix_state_unlock(other); 1933 other->sk_state_change(other); 1934 read_lock(&other->sk_callback_lock); 1935 if (peer_mode == SHUTDOWN_MASK) 1936 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1937 else if (peer_mode & RCV_SHUTDOWN) 1938 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1939 read_unlock(&other->sk_callback_lock); 1940 } 1941 if (other) 1942 sock_put(other); 1943 } 1944 return 0; 1945} 1946 1947static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1948{ 1949 struct sock *sk = sock->sk; 1950 long amount = 0; 1951 int err; 1952 1953 switch (cmd) { 1954 case SIOCOUTQ: 1955 amount = sk_wmem_alloc_get(sk); 1956 err = put_user(amount, (int __user *)arg); 1957 break; 1958 case SIOCINQ: 1959 { 1960 struct sk_buff *skb; 1961 1962 if (sk->sk_state == TCP_LISTEN) { 1963 err = -EINVAL; 1964 break; 1965 } 1966 1967 spin_lock(&sk->sk_receive_queue.lock); 1968 if (sk->sk_type == SOCK_STREAM || 1969 sk->sk_type == SOCK_SEQPACKET) { 1970 skb_queue_walk(&sk->sk_receive_queue, skb) 1971 amount += skb->len; 1972 } else { 1973 skb = skb_peek(&sk->sk_receive_queue); 1974 if (skb) 1975 amount = skb->len; 1976 } 1977 spin_unlock(&sk->sk_receive_queue.lock); 1978 err = put_user(amount, (int __user *)arg); 1979 break; 1980 } 1981 1982 default: 1983 err = -ENOIOCTLCMD; 1984 break; 1985 } 1986 return err; 1987} 1988 1989static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) 1990{ 1991 struct sock *sk = sock->sk; 1992 unsigned int mask; 1993 1994 sock_poll_wait(file, sk->sk_sleep, wait); 1995 mask = 0; 1996 1997 /* exceptional events? */ 1998 if (sk->sk_err) 1999 mask |= POLLERR; 2000 if (sk->sk_shutdown == SHUTDOWN_MASK) 2001 mask |= POLLHUP; 2002 if (sk->sk_shutdown & RCV_SHUTDOWN) 2003 mask |= POLLRDHUP; 2004 2005 /* readable? */ 2006 if (!skb_queue_empty(&sk->sk_receive_queue) || 2007 (sk->sk_shutdown & RCV_SHUTDOWN)) 2008 mask |= POLLIN | POLLRDNORM; 2009 2010 /* Connection-based need to check for termination and startup */ 2011 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && 2012 sk->sk_state == TCP_CLOSE) 2013 mask |= POLLHUP; 2014 2015 /* 2016 * we set writable also when the other side has shut down the 2017 * connection. This prevents stuck sockets. 2018 */ 2019 if (unix_writable(sk)) 2020 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2021 2022 return mask; 2023} 2024 2025static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 2026 poll_table *wait) 2027{ 2028 struct sock *sk = sock->sk, *other; 2029 unsigned int mask, writable; 2030 2031 sock_poll_wait(file, sk->sk_sleep, wait); 2032 mask = 0; 2033 2034 /* exceptional events? */ 2035 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2036 mask |= POLLERR; 2037 if (sk->sk_shutdown & RCV_SHUTDOWN) 2038 mask |= POLLRDHUP; 2039 if (sk->sk_shutdown == SHUTDOWN_MASK) 2040 mask |= POLLHUP; 2041 2042 /* readable? */ 2043 if (!skb_queue_empty(&sk->sk_receive_queue) || 2044 (sk->sk_shutdown & RCV_SHUTDOWN)) 2045 mask |= POLLIN | POLLRDNORM; 2046 2047 /* Connection-based need to check for termination and startup */ 2048 if (sk->sk_type == SOCK_SEQPACKET) { 2049 if (sk->sk_state == TCP_CLOSE) 2050 mask |= POLLHUP; 2051 /* connection hasn't started yet? */ 2052 if (sk->sk_state == TCP_SYN_SENT) 2053 return mask; 2054 } 2055 2056 /* writable? */ 2057 writable = unix_writable(sk); 2058 if (writable) { 2059 other = unix_peer_get(sk); 2060 if (other) { 2061 if (unix_peer(other) != sk) { 2062 sock_poll_wait(file, &unix_sk(other)->peer_wait, 2063 wait); 2064 if (unix_recvq_full(other)) 2065 writable = 0; 2066 } 2067 2068 sock_put(other); 2069 } 2070 } 2071 2072 if (writable) 2073 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2074 else 2075 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2076 2077 return mask; 2078} 2079 2080#ifdef CONFIG_PROC_FS 2081static struct sock *first_unix_socket(int *i) 2082{ 2083 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2084 if (!hlist_empty(&unix_socket_table[*i])) 2085 return __sk_head(&unix_socket_table[*i]); 2086 } 2087 return NULL; 2088} 2089 2090static struct sock *next_unix_socket(int *i, struct sock *s) 2091{ 2092 struct sock *next = sk_next(s); 2093 /* More in this chain? */ 2094 if (next) 2095 return next; 2096 /* Look for next non-empty chain. */ 2097 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2098 if (!hlist_empty(&unix_socket_table[*i])) 2099 return __sk_head(&unix_socket_table[*i]); 2100 } 2101 return NULL; 2102} 2103 2104struct unix_iter_state { 2105 struct seq_net_private p; 2106 int i; 2107}; 2108 2109static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2110{ 2111 struct unix_iter_state *iter = seq->private; 2112 loff_t off = 0; 2113 struct sock *s; 2114 2115 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2116 if (sock_net(s) != seq_file_net(seq)) 2117 continue; 2118 if (off == pos) 2119 return s; 2120 ++off; 2121 } 2122 return NULL; 2123} 2124 2125static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2126 __acquires(unix_table_lock) 2127{ 2128 spin_lock(&unix_table_lock); 2129 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2130} 2131 2132static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2133{ 2134 struct unix_iter_state *iter = seq->private; 2135 struct sock *sk = v; 2136 ++*pos; 2137 2138 if (v == SEQ_START_TOKEN) 2139 sk = first_unix_socket(&iter->i); 2140 else 2141 sk = next_unix_socket(&iter->i, sk); 2142 while (sk && (sock_net(sk) != seq_file_net(seq))) 2143 sk = next_unix_socket(&iter->i, sk); 2144 return sk; 2145} 2146 2147static void unix_seq_stop(struct seq_file *seq, void *v) 2148 __releases(unix_table_lock) 2149{ 2150 spin_unlock(&unix_table_lock); 2151} 2152 2153static int unix_seq_show(struct seq_file *seq, void *v) 2154{ 2155 2156 if (v == SEQ_START_TOKEN) 2157 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2158 "Inode Path\n"); 2159 else { 2160 struct sock *s = v; 2161 struct unix_sock *u = unix_sk(s); 2162 unix_state_lock(s); 2163 2164 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2165 s, 2166 atomic_read(&s->sk_refcnt), 2167 0, 2168 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2169 s->sk_type, 2170 s->sk_socket ? 2171 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2172 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2173 sock_i_ino(s)); 2174 2175 if (u->addr) { 2176 int i, len; 2177 seq_putc(seq, ' '); 2178 2179 i = 0; 2180 len = u->addr->len - sizeof(short); 2181 if (!UNIX_ABSTRACT(s)) 2182 len--; 2183 else { 2184 seq_putc(seq, '@'); 2185 i++; 2186 } 2187 for ( ; i < len; i++) 2188 seq_putc(seq, u->addr->name->sun_path[i]); 2189 } 2190 unix_state_unlock(s); 2191 seq_putc(seq, '\n'); 2192 } 2193 2194 return 0; 2195} 2196 2197static const struct seq_operations unix_seq_ops = { 2198 .start = unix_seq_start, 2199 .next = unix_seq_next, 2200 .stop = unix_seq_stop, 2201 .show = unix_seq_show, 2202}; 2203 2204static int unix_seq_open(struct inode *inode, struct file *file) 2205{ 2206 return seq_open_net(inode, file, &unix_seq_ops, 2207 sizeof(struct unix_iter_state)); 2208} 2209 2210static const struct file_operations unix_seq_fops = { 2211 .owner = THIS_MODULE, 2212 .open = unix_seq_open, 2213 .read = seq_read, 2214 .llseek = seq_lseek, 2215 .release = seq_release_net, 2216}; 2217 2218#endif 2219 2220static const struct net_proto_family unix_family_ops = { 2221 .family = PF_UNIX, 2222 .create = unix_create, 2223 .owner = THIS_MODULE, 2224}; 2225 2226 2227static int __net_init unix_net_init(struct net *net) 2228{ 2229 int error = -ENOMEM; 2230 2231 net->unx.sysctl_max_dgram_qlen = 10; 2232 if (unix_sysctl_register(net)) 2233 goto out; 2234 2235#ifdef CONFIG_PROC_FS 2236 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2237 unix_sysctl_unregister(net); 2238 goto out; 2239 } 2240#endif 2241 error = 0; 2242out: 2243 return error; 2244} 2245 2246static void __net_exit unix_net_exit(struct net *net) 2247{ 2248 unix_sysctl_unregister(net); 2249 proc_net_remove(net, "unix"); 2250} 2251 2252static struct pernet_operations unix_net_ops = { 2253 .init = unix_net_init, 2254 .exit = unix_net_exit, 2255}; 2256 2257static int __init af_unix_init(void) 2258{ 2259 int rc = -1; 2260 struct sk_buff *dummy_skb; 2261 2262 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2263 2264 rc = proto_register(&unix_proto, 1); 2265 if (rc != 0) { 2266 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2267 __func__); 2268 goto out; 2269 } 2270 2271 sock_register(&unix_family_ops); 2272 register_pernet_subsys(&unix_net_ops); 2273out: 2274 return rc; 2275} 2276 2277static void __exit af_unix_exit(void) 2278{ 2279 sock_unregister(PF_UNIX); 2280 proto_unregister(&unix_proto); 2281 unregister_pernet_subsys(&unix_net_ops); 2282} 2283 2284/* Earlier than device_initcall() so that other drivers invoking 2285 request_module() don't end up in a loop when modprobe tries 2286 to use a UNIX socket. But later than subsys_initcall() because 2287 we depend on stuff initialised there */ 2288fs_initcall(af_unix_init); 2289module_exit(af_unix_exit); 2290 2291MODULE_LICENSE("GPL"); 2292MODULE_ALIAS_NETPROTO(PF_UNIX); 2293