af_unix.c revision 6eba6a372b501aa3cdfb7df21a8364099125b9c4
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 rwlock. 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((char *)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->sk_sleep && waitqueue_active(sk->sk_sleep)) 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_DEBUG "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#ifdef UNIX_REFCNT_DEBUG 365 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, 366 atomic_read(&unix_nr_socks)); 367#endif 368} 369 370static int unix_release_sock(struct sock *sk, int embrion) 371{ 372 struct unix_sock *u = unix_sk(sk); 373 struct dentry *dentry; 374 struct vfsmount *mnt; 375 struct sock *skpair; 376 struct sk_buff *skb; 377 int state; 378 379 unix_remove_socket(sk); 380 381 /* Clear state */ 382 unix_state_lock(sk); 383 sock_orphan(sk); 384 sk->sk_shutdown = SHUTDOWN_MASK; 385 dentry = u->dentry; 386 u->dentry = NULL; 387 mnt = u->mnt; 388 u->mnt = NULL; 389 state = sk->sk_state; 390 sk->sk_state = TCP_CLOSE; 391 unix_state_unlock(sk); 392 393 wake_up_interruptible_all(&u->peer_wait); 394 395 skpair = unix_peer(sk); 396 397 if (skpair != NULL) { 398 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { 399 unix_state_lock(skpair); 400 /* No more writes */ 401 skpair->sk_shutdown = SHUTDOWN_MASK; 402 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) 403 skpair->sk_err = ECONNRESET; 404 unix_state_unlock(skpair); 405 skpair->sk_state_change(skpair); 406 read_lock(&skpair->sk_callback_lock); 407 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); 408 read_unlock(&skpair->sk_callback_lock); 409 } 410 sock_put(skpair); /* It may now die */ 411 unix_peer(sk) = NULL; 412 } 413 414 /* Try to flush out this socket. Throw out buffers at least */ 415 416 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { 417 if (state == TCP_LISTEN) 418 unix_release_sock(skb->sk, 1); 419 /* passed fds are erased in the kfree_skb hook */ 420 kfree_skb(skb); 421 } 422 423 if (dentry) { 424 dput(dentry); 425 mntput(mnt); 426 } 427 428 sock_put(sk); 429 430 /* ---- Socket is dead now and most probably destroyed ---- */ 431 432 /* 433 * Fixme: BSD difference: In BSD all sockets connected to use get 434 * ECONNRESET and we die on the spot. In Linux we behave 435 * like files and pipes do and wait for the last 436 * dereference. 437 * 438 * Can't we simply set sock->err? 439 * 440 * What the above comment does talk about? --ANK(980817) 441 */ 442 443 if (unix_tot_inflight) 444 unix_gc(); /* Garbage collect fds */ 445 446 return 0; 447} 448 449static int unix_listen(struct socket *sock, int backlog) 450{ 451 int err; 452 struct sock *sk = sock->sk; 453 struct unix_sock *u = unix_sk(sk); 454 455 err = -EOPNOTSUPP; 456 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) 457 goto out; /* Only stream/seqpacket sockets accept */ 458 err = -EINVAL; 459 if (!u->addr) 460 goto out; /* No listens on an unbound socket */ 461 unix_state_lock(sk); 462 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) 463 goto out_unlock; 464 if (backlog > sk->sk_max_ack_backlog) 465 wake_up_interruptible_all(&u->peer_wait); 466 sk->sk_max_ack_backlog = backlog; 467 sk->sk_state = TCP_LISTEN; 468 /* set credentials so connect can copy them */ 469 sk->sk_peercred.pid = task_tgid_vnr(current); 470 sk->sk_peercred.uid = current->euid; 471 sk->sk_peercred.gid = current->egid; 472 err = 0; 473 474out_unlock: 475 unix_state_unlock(sk); 476out: 477 return err; 478} 479 480static int unix_release(struct socket *); 481static int unix_bind(struct socket *, struct sockaddr *, int); 482static int unix_stream_connect(struct socket *, struct sockaddr *, 483 int addr_len, int flags); 484static int unix_socketpair(struct socket *, struct socket *); 485static int unix_accept(struct socket *, struct socket *, int); 486static int unix_getname(struct socket *, struct sockaddr *, int *, int); 487static unsigned int unix_poll(struct file *, struct socket *, poll_table *); 488static unsigned int unix_dgram_poll(struct file *, struct socket *, 489 poll_table *); 490static int unix_ioctl(struct socket *, unsigned int, unsigned long); 491static int unix_shutdown(struct socket *, int); 492static int unix_stream_sendmsg(struct kiocb *, struct socket *, 493 struct msghdr *, size_t); 494static int unix_stream_recvmsg(struct kiocb *, struct socket *, 495 struct msghdr *, size_t, int); 496static int unix_dgram_sendmsg(struct kiocb *, struct socket *, 497 struct msghdr *, size_t); 498static int unix_dgram_recvmsg(struct kiocb *, struct socket *, 499 struct msghdr *, size_t, int); 500static int unix_dgram_connect(struct socket *, struct sockaddr *, 501 int, int); 502static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, 503 struct msghdr *, size_t); 504 505static const struct proto_ops unix_stream_ops = { 506 .family = PF_UNIX, 507 .owner = THIS_MODULE, 508 .release = unix_release, 509 .bind = unix_bind, 510 .connect = unix_stream_connect, 511 .socketpair = unix_socketpair, 512 .accept = unix_accept, 513 .getname = unix_getname, 514 .poll = unix_poll, 515 .ioctl = unix_ioctl, 516 .listen = unix_listen, 517 .shutdown = unix_shutdown, 518 .setsockopt = sock_no_setsockopt, 519 .getsockopt = sock_no_getsockopt, 520 .sendmsg = unix_stream_sendmsg, 521 .recvmsg = unix_stream_recvmsg, 522 .mmap = sock_no_mmap, 523 .sendpage = sock_no_sendpage, 524}; 525 526static const struct proto_ops unix_dgram_ops = { 527 .family = PF_UNIX, 528 .owner = THIS_MODULE, 529 .release = unix_release, 530 .bind = unix_bind, 531 .connect = unix_dgram_connect, 532 .socketpair = unix_socketpair, 533 .accept = sock_no_accept, 534 .getname = unix_getname, 535 .poll = unix_dgram_poll, 536 .ioctl = unix_ioctl, 537 .listen = sock_no_listen, 538 .shutdown = unix_shutdown, 539 .setsockopt = sock_no_setsockopt, 540 .getsockopt = sock_no_getsockopt, 541 .sendmsg = unix_dgram_sendmsg, 542 .recvmsg = unix_dgram_recvmsg, 543 .mmap = sock_no_mmap, 544 .sendpage = sock_no_sendpage, 545}; 546 547static const struct proto_ops unix_seqpacket_ops = { 548 .family = PF_UNIX, 549 .owner = THIS_MODULE, 550 .release = unix_release, 551 .bind = unix_bind, 552 .connect = unix_stream_connect, 553 .socketpair = unix_socketpair, 554 .accept = unix_accept, 555 .getname = unix_getname, 556 .poll = unix_dgram_poll, 557 .ioctl = unix_ioctl, 558 .listen = unix_listen, 559 .shutdown = unix_shutdown, 560 .setsockopt = sock_no_setsockopt, 561 .getsockopt = sock_no_getsockopt, 562 .sendmsg = unix_seqpacket_sendmsg, 563 .recvmsg = unix_dgram_recvmsg, 564 .mmap = sock_no_mmap, 565 .sendpage = sock_no_sendpage, 566}; 567 568static struct proto unix_proto = { 569 .name = "UNIX", 570 .owner = THIS_MODULE, 571 .obj_size = sizeof(struct unix_sock), 572}; 573 574/* 575 * AF_UNIX sockets do not interact with hardware, hence they 576 * dont trigger interrupts - so it's safe for them to have 577 * bh-unsafe locking for their sk_receive_queue.lock. Split off 578 * this special lock-class by reinitializing the spinlock key: 579 */ 580static struct lock_class_key af_unix_sk_receive_queue_lock_key; 581 582static struct sock *unix_create1(struct net *net, struct socket *sock) 583{ 584 struct sock *sk = NULL; 585 struct unix_sock *u; 586 587 atomic_inc(&unix_nr_socks); 588 if (atomic_read(&unix_nr_socks) > 2 * get_max_files()) 589 goto out; 590 591 sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); 592 if (!sk) 593 goto out; 594 595 sock_init_data(sock, sk); 596 lockdep_set_class(&sk->sk_receive_queue.lock, 597 &af_unix_sk_receive_queue_lock_key); 598 599 sk->sk_write_space = unix_write_space; 600 sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; 601 sk->sk_destruct = unix_sock_destructor; 602 u = unix_sk(sk); 603 u->dentry = NULL; 604 u->mnt = NULL; 605 spin_lock_init(&u->lock); 606 atomic_long_set(&u->inflight, 0); 607 INIT_LIST_HEAD(&u->link); 608 mutex_init(&u->readlock); /* single task reading lock */ 609 init_waitqueue_head(&u->peer_wait); 610 unix_insert_socket(unix_sockets_unbound, sk); 611out: 612 if (sk == NULL) 613 atomic_dec(&unix_nr_socks); 614 return sk; 615} 616 617static int unix_create(struct net *net, struct socket *sock, int protocol) 618{ 619 if (protocol && protocol != PF_UNIX) 620 return -EPROTONOSUPPORT; 621 622 sock->state = SS_UNCONNECTED; 623 624 switch (sock->type) { 625 case SOCK_STREAM: 626 sock->ops = &unix_stream_ops; 627 break; 628 /* 629 * Believe it or not BSD has AF_UNIX, SOCK_RAW though 630 * nothing uses it. 631 */ 632 case SOCK_RAW: 633 sock->type = SOCK_DGRAM; 634 case SOCK_DGRAM: 635 sock->ops = &unix_dgram_ops; 636 break; 637 case SOCK_SEQPACKET: 638 sock->ops = &unix_seqpacket_ops; 639 break; 640 default: 641 return -ESOCKTNOSUPPORT; 642 } 643 644 return unix_create1(net, sock) ? 0 : -ENOMEM; 645} 646 647static int unix_release(struct socket *sock) 648{ 649 struct sock *sk = sock->sk; 650 651 if (!sk) 652 return 0; 653 654 sock->sk = NULL; 655 656 return unix_release_sock(sk, 0); 657} 658 659static int unix_autobind(struct socket *sock) 660{ 661 struct sock *sk = sock->sk; 662 struct net *net = sock_net(sk); 663 struct unix_sock *u = unix_sk(sk); 664 static u32 ordernum = 1; 665 struct unix_address *addr; 666 int err; 667 668 mutex_lock(&u->readlock); 669 670 err = 0; 671 if (u->addr) 672 goto out; 673 674 err = -ENOMEM; 675 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); 676 if (!addr) 677 goto out; 678 679 addr->name->sun_family = AF_UNIX; 680 atomic_set(&addr->refcnt, 1); 681 682retry: 683 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); 684 addr->hash = unix_hash_fold(csum_partial((void *)addr->name, addr->len, 0)); 685 686 spin_lock(&unix_table_lock); 687 ordernum = (ordernum+1)&0xFFFFF; 688 689 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, 690 addr->hash)) { 691 spin_unlock(&unix_table_lock); 692 /* Sanity yield. It is unusual case, but yet... */ 693 if (!(ordernum&0xFF)) 694 yield(); 695 goto retry; 696 } 697 addr->hash ^= sk->sk_type; 698 699 __unix_remove_socket(sk); 700 u->addr = addr; 701 __unix_insert_socket(&unix_socket_table[addr->hash], sk); 702 spin_unlock(&unix_table_lock); 703 err = 0; 704 705out: mutex_unlock(&u->readlock); 706 return err; 707} 708 709static struct sock *unix_find_other(struct net *net, 710 struct sockaddr_un *sunname, int len, 711 int type, unsigned hash, int *error) 712{ 713 struct sock *u; 714 struct path path; 715 int err = 0; 716 717 if (sunname->sun_path[0]) { 718 struct inode *inode; 719 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); 720 if (err) 721 goto fail; 722 inode = path.dentry->d_inode; 723 err = inode_permission(inode, MAY_WRITE); 724 if (err) 725 goto put_fail; 726 727 err = -ECONNREFUSED; 728 if (!S_ISSOCK(inode->i_mode)) 729 goto put_fail; 730 u = unix_find_socket_byinode(net, inode); 731 if (!u) 732 goto put_fail; 733 734 if (u->sk_type == type) 735 touch_atime(path.mnt, path.dentry); 736 737 path_put(&path); 738 739 err = -EPROTOTYPE; 740 if (u->sk_type != type) { 741 sock_put(u); 742 goto fail; 743 } 744 } else { 745 err = -ECONNREFUSED; 746 u = unix_find_socket_byname(net, sunname, len, type, hash); 747 if (u) { 748 struct dentry *dentry; 749 dentry = unix_sk(u)->dentry; 750 if (dentry) 751 touch_atime(unix_sk(u)->mnt, dentry); 752 } else 753 goto fail; 754 } 755 return u; 756 757put_fail: 758 path_put(&path); 759fail: 760 *error = err; 761 return NULL; 762} 763 764 765static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 766{ 767 struct sock *sk = sock->sk; 768 struct net *net = sock_net(sk); 769 struct unix_sock *u = unix_sk(sk); 770 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 771 struct dentry *dentry = NULL; 772 struct nameidata nd; 773 int err; 774 unsigned hash; 775 struct unix_address *addr; 776 struct hlist_head *list; 777 778 err = -EINVAL; 779 if (sunaddr->sun_family != AF_UNIX) 780 goto out; 781 782 if (addr_len == sizeof(short)) { 783 err = unix_autobind(sock); 784 goto out; 785 } 786 787 err = unix_mkname(sunaddr, addr_len, &hash); 788 if (err < 0) 789 goto out; 790 addr_len = err; 791 792 mutex_lock(&u->readlock); 793 794 err = -EINVAL; 795 if (u->addr) 796 goto out_up; 797 798 err = -ENOMEM; 799 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); 800 if (!addr) 801 goto out_up; 802 803 memcpy(addr->name, sunaddr, addr_len); 804 addr->len = addr_len; 805 addr->hash = hash ^ sk->sk_type; 806 atomic_set(&addr->refcnt, 1); 807 808 if (sunaddr->sun_path[0]) { 809 unsigned int mode; 810 err = 0; 811 /* 812 * Get the parent directory, calculate the hash for last 813 * component. 814 */ 815 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); 816 if (err) 817 goto out_mknod_parent; 818 819 dentry = lookup_create(&nd, 0); 820 err = PTR_ERR(dentry); 821 if (IS_ERR(dentry)) 822 goto out_mknod_unlock; 823 824 /* 825 * All right, let's create it. 826 */ 827 mode = S_IFSOCK | 828 (SOCK_INODE(sock)->i_mode & ~current->fs->umask); 829 err = mnt_want_write(nd.path.mnt); 830 if (err) 831 goto out_mknod_dput; 832 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); 833 mnt_drop_write(nd.path.mnt); 834 if (err) 835 goto out_mknod_dput; 836 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 837 dput(nd.path.dentry); 838 nd.path.dentry = dentry; 839 840 addr->hash = UNIX_HASH_SIZE; 841 } 842 843 spin_lock(&unix_table_lock); 844 845 if (!sunaddr->sun_path[0]) { 846 err = -EADDRINUSE; 847 if (__unix_find_socket_byname(net, sunaddr, addr_len, 848 sk->sk_type, hash)) { 849 unix_release_addr(addr); 850 goto out_unlock; 851 } 852 853 list = &unix_socket_table[addr->hash]; 854 } else { 855 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; 856 u->dentry = nd.path.dentry; 857 u->mnt = nd.path.mnt; 858 } 859 860 err = 0; 861 __unix_remove_socket(sk); 862 u->addr = addr; 863 __unix_insert_socket(list, sk); 864 865out_unlock: 866 spin_unlock(&unix_table_lock); 867out_up: 868 mutex_unlock(&u->readlock); 869out: 870 return err; 871 872out_mknod_dput: 873 dput(dentry); 874out_mknod_unlock: 875 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 876 path_put(&nd.path); 877out_mknod_parent: 878 if (err == -EEXIST) 879 err = -EADDRINUSE; 880 unix_release_addr(addr); 881 goto out_up; 882} 883 884static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) 885{ 886 if (unlikely(sk1 == sk2) || !sk2) { 887 unix_state_lock(sk1); 888 return; 889 } 890 if (sk1 < sk2) { 891 unix_state_lock(sk1); 892 unix_state_lock_nested(sk2); 893 } else { 894 unix_state_lock(sk2); 895 unix_state_lock_nested(sk1); 896 } 897} 898 899static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) 900{ 901 if (unlikely(sk1 == sk2) || !sk2) { 902 unix_state_unlock(sk1); 903 return; 904 } 905 unix_state_unlock(sk1); 906 unix_state_unlock(sk2); 907} 908 909static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 910 int alen, int flags) 911{ 912 struct sock *sk = sock->sk; 913 struct net *net = sock_net(sk); 914 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; 915 struct sock *other; 916 unsigned hash; 917 int err; 918 919 if (addr->sa_family != AF_UNSPEC) { 920 err = unix_mkname(sunaddr, alen, &hash); 921 if (err < 0) 922 goto out; 923 alen = err; 924 925 if (test_bit(SOCK_PASSCRED, &sock->flags) && 926 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) 927 goto out; 928 929restart: 930 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); 931 if (!other) 932 goto out; 933 934 unix_state_double_lock(sk, other); 935 936 /* Apparently VFS overslept socket death. Retry. */ 937 if (sock_flag(other, SOCK_DEAD)) { 938 unix_state_double_unlock(sk, other); 939 sock_put(other); 940 goto restart; 941 } 942 943 err = -EPERM; 944 if (!unix_may_send(sk, other)) 945 goto out_unlock; 946 947 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 948 if (err) 949 goto out_unlock; 950 951 } else { 952 /* 953 * 1003.1g breaking connected state with AF_UNSPEC 954 */ 955 other = NULL; 956 unix_state_double_lock(sk, other); 957 } 958 959 /* 960 * If it was connected, reconnect. 961 */ 962 if (unix_peer(sk)) { 963 struct sock *old_peer = unix_peer(sk); 964 unix_peer(sk) = other; 965 unix_state_double_unlock(sk, other); 966 967 if (other != old_peer) 968 unix_dgram_disconnected(sk, old_peer); 969 sock_put(old_peer); 970 } else { 971 unix_peer(sk) = other; 972 unix_state_double_unlock(sk, other); 973 } 974 return 0; 975 976out_unlock: 977 unix_state_double_unlock(sk, other); 978 sock_put(other); 979out: 980 return err; 981} 982 983static long unix_wait_for_peer(struct sock *other, long timeo) 984{ 985 struct unix_sock *u = unix_sk(other); 986 int sched; 987 DEFINE_WAIT(wait); 988 989 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); 990 991 sched = !sock_flag(other, SOCK_DEAD) && 992 !(other->sk_shutdown & RCV_SHUTDOWN) && 993 unix_recvq_full(other); 994 995 unix_state_unlock(other); 996 997 if (sched) 998 timeo = schedule_timeout(timeo); 999 1000 finish_wait(&u->peer_wait, &wait); 1001 return timeo; 1002} 1003 1004static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, 1005 int addr_len, int flags) 1006{ 1007 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 1008 struct sock *sk = sock->sk; 1009 struct net *net = sock_net(sk); 1010 struct unix_sock *u = unix_sk(sk), *newu, *otheru; 1011 struct sock *newsk = NULL; 1012 struct sock *other = NULL; 1013 struct sk_buff *skb = NULL; 1014 unsigned hash; 1015 int st; 1016 int err; 1017 long timeo; 1018 1019 err = unix_mkname(sunaddr, addr_len, &hash); 1020 if (err < 0) 1021 goto out; 1022 addr_len = err; 1023 1024 if (test_bit(SOCK_PASSCRED, &sock->flags) 1025 && !u->addr && (err = unix_autobind(sock)) != 0) 1026 goto out; 1027 1028 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 1029 1030 /* First of all allocate resources. 1031 If we will make it after state is locked, 1032 we will have to recheck all again in any case. 1033 */ 1034 1035 err = -ENOMEM; 1036 1037 /* create new sock for complete connection */ 1038 newsk = unix_create1(sock_net(sk), NULL); 1039 if (newsk == NULL) 1040 goto out; 1041 1042 /* Allocate skb for sending to listening sock */ 1043 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); 1044 if (skb == NULL) 1045 goto out; 1046 1047restart: 1048 /* Find listening sock. */ 1049 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); 1050 if (!other) 1051 goto out; 1052 1053 /* Latch state of peer */ 1054 unix_state_lock(other); 1055 1056 /* Apparently VFS overslept socket death. Retry. */ 1057 if (sock_flag(other, SOCK_DEAD)) { 1058 unix_state_unlock(other); 1059 sock_put(other); 1060 goto restart; 1061 } 1062 1063 err = -ECONNREFUSED; 1064 if (other->sk_state != TCP_LISTEN) 1065 goto out_unlock; 1066 1067 if (unix_recvq_full(other)) { 1068 err = -EAGAIN; 1069 if (!timeo) 1070 goto out_unlock; 1071 1072 timeo = unix_wait_for_peer(other, timeo); 1073 1074 err = sock_intr_errno(timeo); 1075 if (signal_pending(current)) 1076 goto out; 1077 sock_put(other); 1078 goto restart; 1079 } 1080 1081 /* Latch our state. 1082 1083 It is tricky place. We need to grab write lock and cannot 1084 drop lock on peer. It is dangerous because deadlock is 1085 possible. Connect to self case and simultaneous 1086 attempt to connect are eliminated by checking socket 1087 state. other is TCP_LISTEN, if sk is TCP_LISTEN we 1088 check this before attempt to grab lock. 1089 1090 Well, and we have to recheck the state after socket locked. 1091 */ 1092 st = sk->sk_state; 1093 1094 switch (st) { 1095 case TCP_CLOSE: 1096 /* This is ok... continue with connect */ 1097 break; 1098 case TCP_ESTABLISHED: 1099 /* Socket is already connected */ 1100 err = -EISCONN; 1101 goto out_unlock; 1102 default: 1103 err = -EINVAL; 1104 goto out_unlock; 1105 } 1106 1107 unix_state_lock_nested(sk); 1108 1109 if (sk->sk_state != st) { 1110 unix_state_unlock(sk); 1111 unix_state_unlock(other); 1112 sock_put(other); 1113 goto restart; 1114 } 1115 1116 err = security_unix_stream_connect(sock, other->sk_socket, newsk); 1117 if (err) { 1118 unix_state_unlock(sk); 1119 goto out_unlock; 1120 } 1121 1122 /* The way is open! Fastly set all the necessary fields... */ 1123 1124 sock_hold(sk); 1125 unix_peer(newsk) = sk; 1126 newsk->sk_state = TCP_ESTABLISHED; 1127 newsk->sk_type = sk->sk_type; 1128 newsk->sk_peercred.pid = task_tgid_vnr(current); 1129 newsk->sk_peercred.uid = current->euid; 1130 newsk->sk_peercred.gid = current->egid; 1131 newu = unix_sk(newsk); 1132 newsk->sk_sleep = &newu->peer_wait; 1133 otheru = unix_sk(other); 1134 1135 /* copy address information from listening to new sock*/ 1136 if (otheru->addr) { 1137 atomic_inc(&otheru->addr->refcnt); 1138 newu->addr = otheru->addr; 1139 } 1140 if (otheru->dentry) { 1141 newu->dentry = dget(otheru->dentry); 1142 newu->mnt = mntget(otheru->mnt); 1143 } 1144 1145 /* Set credentials */ 1146 sk->sk_peercred = other->sk_peercred; 1147 1148 sock->state = SS_CONNECTED; 1149 sk->sk_state = TCP_ESTABLISHED; 1150 sock_hold(newsk); 1151 1152 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ 1153 unix_peer(sk) = newsk; 1154 1155 unix_state_unlock(sk); 1156 1157 /* take ten and and send info to listening sock */ 1158 spin_lock(&other->sk_receive_queue.lock); 1159 __skb_queue_tail(&other->sk_receive_queue, skb); 1160 spin_unlock(&other->sk_receive_queue.lock); 1161 unix_state_unlock(other); 1162 other->sk_data_ready(other, 0); 1163 sock_put(other); 1164 return 0; 1165 1166out_unlock: 1167 if (other) 1168 unix_state_unlock(other); 1169 1170out: 1171 if (skb) 1172 kfree_skb(skb); 1173 if (newsk) 1174 unix_release_sock(newsk, 0); 1175 if (other) 1176 sock_put(other); 1177 return err; 1178} 1179 1180static int unix_socketpair(struct socket *socka, struct socket *sockb) 1181{ 1182 struct sock *ska = socka->sk, *skb = sockb->sk; 1183 1184 /* Join our sockets back to back */ 1185 sock_hold(ska); 1186 sock_hold(skb); 1187 unix_peer(ska) = skb; 1188 unix_peer(skb) = ska; 1189 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current); 1190 ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid; 1191 ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid; 1192 1193 if (ska->sk_type != SOCK_DGRAM) { 1194 ska->sk_state = TCP_ESTABLISHED; 1195 skb->sk_state = TCP_ESTABLISHED; 1196 socka->state = SS_CONNECTED; 1197 sockb->state = SS_CONNECTED; 1198 } 1199 return 0; 1200} 1201 1202static int unix_accept(struct socket *sock, struct socket *newsock, int flags) 1203{ 1204 struct sock *sk = sock->sk; 1205 struct sock *tsk; 1206 struct sk_buff *skb; 1207 int err; 1208 1209 err = -EOPNOTSUPP; 1210 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) 1211 goto out; 1212 1213 err = -EINVAL; 1214 if (sk->sk_state != TCP_LISTEN) 1215 goto out; 1216 1217 /* If socket state is TCP_LISTEN it cannot change (for now...), 1218 * so that no locks are necessary. 1219 */ 1220 1221 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); 1222 if (!skb) { 1223 /* This means receive shutdown. */ 1224 if (err == 0) 1225 err = -EINVAL; 1226 goto out; 1227 } 1228 1229 tsk = skb->sk; 1230 skb_free_datagram(sk, skb); 1231 wake_up_interruptible(&unix_sk(sk)->peer_wait); 1232 1233 /* attach accepted sock to socket */ 1234 unix_state_lock(tsk); 1235 newsock->state = SS_CONNECTED; 1236 sock_graft(tsk, newsock); 1237 unix_state_unlock(tsk); 1238 return 0; 1239 1240out: 1241 return err; 1242} 1243 1244 1245static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) 1246{ 1247 struct sock *sk = sock->sk; 1248 struct unix_sock *u; 1249 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 1250 int err = 0; 1251 1252 if (peer) { 1253 sk = unix_peer_get(sk); 1254 1255 err = -ENOTCONN; 1256 if (!sk) 1257 goto out; 1258 err = 0; 1259 } else { 1260 sock_hold(sk); 1261 } 1262 1263 u = unix_sk(sk); 1264 unix_state_lock(sk); 1265 if (!u->addr) { 1266 sunaddr->sun_family = AF_UNIX; 1267 sunaddr->sun_path[0] = 0; 1268 *uaddr_len = sizeof(short); 1269 } else { 1270 struct unix_address *addr = u->addr; 1271 1272 *uaddr_len = addr->len; 1273 memcpy(sunaddr, addr->name, *uaddr_len); 1274 } 1275 unix_state_unlock(sk); 1276 sock_put(sk); 1277out: 1278 return err; 1279} 1280 1281static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1282{ 1283 int i; 1284 1285 scm->fp = UNIXCB(skb).fp; 1286 skb->destructor = sock_wfree; 1287 UNIXCB(skb).fp = NULL; 1288 1289 for (i = scm->fp->count-1; i >= 0; i--) 1290 unix_notinflight(scm->fp->fp[i]); 1291} 1292 1293static void unix_destruct_fds(struct sk_buff *skb) 1294{ 1295 struct scm_cookie scm; 1296 memset(&scm, 0, sizeof(scm)); 1297 unix_detach_fds(&scm, skb); 1298 1299 /* Alas, it calls VFS */ 1300 /* So fscking what? fput() had been SMP-safe since the last Summer */ 1301 scm_destroy(&scm); 1302 sock_wfree(skb); 1303} 1304 1305static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1306{ 1307 int i; 1308 1309 /* 1310 * Need to duplicate file references for the sake of garbage 1311 * collection. Otherwise a socket in the fps might become a 1312 * candidate for GC while the skb is not yet queued. 1313 */ 1314 UNIXCB(skb).fp = scm_fp_dup(scm->fp); 1315 if (!UNIXCB(skb).fp) 1316 return -ENOMEM; 1317 1318 for (i = scm->fp->count-1; i >= 0; i--) 1319 unix_inflight(scm->fp->fp[i]); 1320 skb->destructor = unix_destruct_fds; 1321 return 0; 1322} 1323 1324/* 1325 * Send AF_UNIX data. 1326 */ 1327 1328static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 1329 struct msghdr *msg, size_t len) 1330{ 1331 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1332 struct sock *sk = sock->sk; 1333 struct net *net = sock_net(sk); 1334 struct unix_sock *u = unix_sk(sk); 1335 struct sockaddr_un *sunaddr = msg->msg_name; 1336 struct sock *other = NULL; 1337 int namelen = 0; /* fake GCC */ 1338 int err; 1339 unsigned hash; 1340 struct sk_buff *skb; 1341 long timeo; 1342 struct scm_cookie tmp_scm; 1343 1344 if (NULL == siocb->scm) 1345 siocb->scm = &tmp_scm; 1346 err = scm_send(sock, msg, siocb->scm); 1347 if (err < 0) 1348 return err; 1349 1350 err = -EOPNOTSUPP; 1351 if (msg->msg_flags&MSG_OOB) 1352 goto out; 1353 1354 if (msg->msg_namelen) { 1355 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1356 if (err < 0) 1357 goto out; 1358 namelen = err; 1359 } else { 1360 sunaddr = NULL; 1361 err = -ENOTCONN; 1362 other = unix_peer_get(sk); 1363 if (!other) 1364 goto out; 1365 } 1366 1367 if (test_bit(SOCK_PASSCRED, &sock->flags) 1368 && !u->addr && (err = unix_autobind(sock)) != 0) 1369 goto out; 1370 1371 err = -EMSGSIZE; 1372 if (len > sk->sk_sndbuf - 32) 1373 goto out; 1374 1375 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1376 if (skb == NULL) 1377 goto out; 1378 1379 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1380 if (siocb->scm->fp) { 1381 err = unix_attach_fds(siocb->scm, skb); 1382 if (err) 1383 goto out_free; 1384 } 1385 unix_get_secdata(siocb->scm, skb); 1386 1387 skb_reset_transport_header(skb); 1388 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1389 if (err) 1390 goto out_free; 1391 1392 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1393 1394restart: 1395 if (!other) { 1396 err = -ECONNRESET; 1397 if (sunaddr == NULL) 1398 goto out_free; 1399 1400 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1401 hash, &err); 1402 if (other == NULL) 1403 goto out_free; 1404 } 1405 1406 unix_state_lock(other); 1407 err = -EPERM; 1408 if (!unix_may_send(sk, other)) 1409 goto out_unlock; 1410 1411 if (sock_flag(other, SOCK_DEAD)) { 1412 /* 1413 * Check with 1003.1g - what should 1414 * datagram error 1415 */ 1416 unix_state_unlock(other); 1417 sock_put(other); 1418 1419 err = 0; 1420 unix_state_lock(sk); 1421 if (unix_peer(sk) == other) { 1422 unix_peer(sk) = NULL; 1423 unix_state_unlock(sk); 1424 1425 unix_dgram_disconnected(sk, other); 1426 sock_put(other); 1427 err = -ECONNREFUSED; 1428 } else { 1429 unix_state_unlock(sk); 1430 } 1431 1432 other = NULL; 1433 if (err) 1434 goto out_free; 1435 goto restart; 1436 } 1437 1438 err = -EPIPE; 1439 if (other->sk_shutdown & RCV_SHUTDOWN) 1440 goto out_unlock; 1441 1442 if (sk->sk_type != SOCK_SEQPACKET) { 1443 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1444 if (err) 1445 goto out_unlock; 1446 } 1447 1448 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1449 if (!timeo) { 1450 err = -EAGAIN; 1451 goto out_unlock; 1452 } 1453 1454 timeo = unix_wait_for_peer(other, timeo); 1455 1456 err = sock_intr_errno(timeo); 1457 if (signal_pending(current)) 1458 goto out_free; 1459 1460 goto restart; 1461 } 1462 1463 skb_queue_tail(&other->sk_receive_queue, skb); 1464 unix_state_unlock(other); 1465 other->sk_data_ready(other, len); 1466 sock_put(other); 1467 scm_destroy(siocb->scm); 1468 return len; 1469 1470out_unlock: 1471 unix_state_unlock(other); 1472out_free: 1473 kfree_skb(skb); 1474out: 1475 if (other) 1476 sock_put(other); 1477 scm_destroy(siocb->scm); 1478 return err; 1479} 1480 1481 1482static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1483 struct msghdr *msg, size_t len) 1484{ 1485 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1486 struct sock *sk = sock->sk; 1487 struct sock *other = NULL; 1488 struct sockaddr_un *sunaddr = msg->msg_name; 1489 int err, size; 1490 struct sk_buff *skb; 1491 int sent = 0; 1492 struct scm_cookie tmp_scm; 1493 1494 if (NULL == siocb->scm) 1495 siocb->scm = &tmp_scm; 1496 err = scm_send(sock, msg, siocb->scm); 1497 if (err < 0) 1498 return err; 1499 1500 err = -EOPNOTSUPP; 1501 if (msg->msg_flags&MSG_OOB) 1502 goto out_err; 1503 1504 if (msg->msg_namelen) { 1505 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1506 goto out_err; 1507 } else { 1508 sunaddr = NULL; 1509 err = -ENOTCONN; 1510 other = unix_peer(sk); 1511 if (!other) 1512 goto out_err; 1513 } 1514 1515 if (sk->sk_shutdown & SEND_SHUTDOWN) 1516 goto pipe_err; 1517 1518 while (sent < len) { 1519 /* 1520 * Optimisation for the fact that under 0.01% of X 1521 * messages typically need breaking up. 1522 */ 1523 1524 size = len-sent; 1525 1526 /* Keep two messages in the pipe so it schedules better */ 1527 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1528 size = (sk->sk_sndbuf >> 1) - 64; 1529 1530 if (size > SKB_MAX_ALLOC) 1531 size = SKB_MAX_ALLOC; 1532 1533 /* 1534 * Grab a buffer 1535 */ 1536 1537 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, 1538 &err); 1539 1540 if (skb == NULL) 1541 goto out_err; 1542 1543 /* 1544 * If you pass two values to the sock_alloc_send_skb 1545 * it tries to grab the large buffer with GFP_NOFS 1546 * (which can fail easily), and if it fails grab the 1547 * fallback size buffer which is under a page and will 1548 * succeed. [Alan] 1549 */ 1550 size = min_t(int, size, skb_tailroom(skb)); 1551 1552 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1553 if (siocb->scm->fp) { 1554 err = unix_attach_fds(siocb->scm, skb); 1555 if (err) { 1556 kfree_skb(skb); 1557 goto out_err; 1558 } 1559 } 1560 1561 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 1562 if (err) { 1563 kfree_skb(skb); 1564 goto out_err; 1565 } 1566 1567 unix_state_lock(other); 1568 1569 if (sock_flag(other, SOCK_DEAD) || 1570 (other->sk_shutdown & RCV_SHUTDOWN)) 1571 goto pipe_err_free; 1572 1573 skb_queue_tail(&other->sk_receive_queue, skb); 1574 unix_state_unlock(other); 1575 other->sk_data_ready(other, size); 1576 sent += size; 1577 } 1578 1579 scm_destroy(siocb->scm); 1580 siocb->scm = NULL; 1581 1582 return sent; 1583 1584pipe_err_free: 1585 unix_state_unlock(other); 1586 kfree_skb(skb); 1587pipe_err: 1588 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1589 send_sig(SIGPIPE, current, 0); 1590 err = -EPIPE; 1591out_err: 1592 scm_destroy(siocb->scm); 1593 siocb->scm = NULL; 1594 return sent ? : err; 1595} 1596 1597static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1598 struct msghdr *msg, size_t len) 1599{ 1600 int err; 1601 struct sock *sk = sock->sk; 1602 1603 err = sock_error(sk); 1604 if (err) 1605 return err; 1606 1607 if (sk->sk_state != TCP_ESTABLISHED) 1608 return -ENOTCONN; 1609 1610 if (msg->msg_namelen) 1611 msg->msg_namelen = 0; 1612 1613 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1614} 1615 1616static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1617{ 1618 struct unix_sock *u = unix_sk(sk); 1619 1620 msg->msg_namelen = 0; 1621 if (u->addr) { 1622 msg->msg_namelen = u->addr->len; 1623 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1624 } 1625} 1626 1627static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1628 struct msghdr *msg, size_t size, 1629 int flags) 1630{ 1631 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1632 struct scm_cookie tmp_scm; 1633 struct sock *sk = sock->sk; 1634 struct unix_sock *u = unix_sk(sk); 1635 int noblock = flags & MSG_DONTWAIT; 1636 struct sk_buff *skb; 1637 int err; 1638 1639 err = -EOPNOTSUPP; 1640 if (flags&MSG_OOB) 1641 goto out; 1642 1643 msg->msg_namelen = 0; 1644 1645 mutex_lock(&u->readlock); 1646 1647 skb = skb_recv_datagram(sk, flags, noblock, &err); 1648 if (!skb) { 1649 unix_state_lock(sk); 1650 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1651 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1652 (sk->sk_shutdown & RCV_SHUTDOWN)) 1653 err = 0; 1654 unix_state_unlock(sk); 1655 goto out_unlock; 1656 } 1657 1658 wake_up_interruptible_sync(&u->peer_wait); 1659 1660 if (msg->msg_name) 1661 unix_copy_addr(msg, skb->sk); 1662 1663 if (size > skb->len) 1664 size = skb->len; 1665 else if (size < skb->len) 1666 msg->msg_flags |= MSG_TRUNC; 1667 1668 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1669 if (err) 1670 goto out_free; 1671 1672 if (!siocb->scm) { 1673 siocb->scm = &tmp_scm; 1674 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1675 } 1676 siocb->scm->creds = *UNIXCREDS(skb); 1677 unix_set_secdata(siocb->scm, skb); 1678 1679 if (!(flags & MSG_PEEK)) { 1680 if (UNIXCB(skb).fp) 1681 unix_detach_fds(siocb->scm, skb); 1682 } else { 1683 /* It is questionable: on PEEK we could: 1684 - do not return fds - good, but too simple 8) 1685 - return fds, and do not return them on read (old strategy, 1686 apparently wrong) 1687 - clone fds (I chose it for now, it is the most universal 1688 solution) 1689 1690 POSIX 1003.1g does not actually define this clearly 1691 at all. POSIX 1003.1g doesn't define a lot of things 1692 clearly however! 1693 1694 */ 1695 if (UNIXCB(skb).fp) 1696 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1697 } 1698 err = size; 1699 1700 scm_recv(sock, msg, siocb->scm, flags); 1701 1702out_free: 1703 skb_free_datagram(sk, skb); 1704out_unlock: 1705 mutex_unlock(&u->readlock); 1706out: 1707 return err; 1708} 1709 1710/* 1711 * Sleep until data has arrive. But check for races.. 1712 */ 1713 1714static long unix_stream_data_wait(struct sock *sk, long timeo) 1715{ 1716 DEFINE_WAIT(wait); 1717 1718 unix_state_lock(sk); 1719 1720 for (;;) { 1721 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1722 1723 if (!skb_queue_empty(&sk->sk_receive_queue) || 1724 sk->sk_err || 1725 (sk->sk_shutdown & RCV_SHUTDOWN) || 1726 signal_pending(current) || 1727 !timeo) 1728 break; 1729 1730 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1731 unix_state_unlock(sk); 1732 timeo = schedule_timeout(timeo); 1733 unix_state_lock(sk); 1734 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1735 } 1736 1737 finish_wait(sk->sk_sleep, &wait); 1738 unix_state_unlock(sk); 1739 return timeo; 1740} 1741 1742 1743 1744static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1745 struct msghdr *msg, size_t size, 1746 int flags) 1747{ 1748 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1749 struct scm_cookie tmp_scm; 1750 struct sock *sk = sock->sk; 1751 struct unix_sock *u = unix_sk(sk); 1752 struct sockaddr_un *sunaddr = msg->msg_name; 1753 int copied = 0; 1754 int check_creds = 0; 1755 int target; 1756 int err = 0; 1757 long timeo; 1758 1759 err = -EINVAL; 1760 if (sk->sk_state != TCP_ESTABLISHED) 1761 goto out; 1762 1763 err = -EOPNOTSUPP; 1764 if (flags&MSG_OOB) 1765 goto out; 1766 1767 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1768 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1769 1770 msg->msg_namelen = 0; 1771 1772 /* Lock the socket to prevent queue disordering 1773 * while sleeps in memcpy_tomsg 1774 */ 1775 1776 if (!siocb->scm) { 1777 siocb->scm = &tmp_scm; 1778 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1779 } 1780 1781 mutex_lock(&u->readlock); 1782 1783 do { 1784 int chunk; 1785 struct sk_buff *skb; 1786 1787 unix_state_lock(sk); 1788 skb = skb_dequeue(&sk->sk_receive_queue); 1789 if (skb == NULL) { 1790 if (copied >= target) 1791 goto unlock; 1792 1793 /* 1794 * POSIX 1003.1g mandates this order. 1795 */ 1796 1797 err = sock_error(sk); 1798 if (err) 1799 goto unlock; 1800 if (sk->sk_shutdown & RCV_SHUTDOWN) 1801 goto unlock; 1802 1803 unix_state_unlock(sk); 1804 err = -EAGAIN; 1805 if (!timeo) 1806 break; 1807 mutex_unlock(&u->readlock); 1808 1809 timeo = unix_stream_data_wait(sk, timeo); 1810 1811 if (signal_pending(current)) { 1812 err = sock_intr_errno(timeo); 1813 goto out; 1814 } 1815 mutex_lock(&u->readlock); 1816 continue; 1817 unlock: 1818 unix_state_unlock(sk); 1819 break; 1820 } 1821 unix_state_unlock(sk); 1822 1823 if (check_creds) { 1824 /* Never glue messages from different writers */ 1825 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, 1826 sizeof(siocb->scm->creds)) != 0) { 1827 skb_queue_head(&sk->sk_receive_queue, skb); 1828 break; 1829 } 1830 } else { 1831 /* Copy credentials */ 1832 siocb->scm->creds = *UNIXCREDS(skb); 1833 check_creds = 1; 1834 } 1835 1836 /* Copy address just once */ 1837 if (sunaddr) { 1838 unix_copy_addr(msg, skb->sk); 1839 sunaddr = NULL; 1840 } 1841 1842 chunk = min_t(unsigned int, skb->len, size); 1843 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1844 skb_queue_head(&sk->sk_receive_queue, skb); 1845 if (copied == 0) 1846 copied = -EFAULT; 1847 break; 1848 } 1849 copied += chunk; 1850 size -= chunk; 1851 1852 /* Mark read part of skb as used */ 1853 if (!(flags & MSG_PEEK)) { 1854 skb_pull(skb, chunk); 1855 1856 if (UNIXCB(skb).fp) 1857 unix_detach_fds(siocb->scm, skb); 1858 1859 /* put the skb back if we didn't use it up.. */ 1860 if (skb->len) { 1861 skb_queue_head(&sk->sk_receive_queue, skb); 1862 break; 1863 } 1864 1865 kfree_skb(skb); 1866 1867 if (siocb->scm->fp) 1868 break; 1869 } else { 1870 /* It is questionable, see note in unix_dgram_recvmsg. 1871 */ 1872 if (UNIXCB(skb).fp) 1873 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1874 1875 /* put message back and return */ 1876 skb_queue_head(&sk->sk_receive_queue, skb); 1877 break; 1878 } 1879 } while (size); 1880 1881 mutex_unlock(&u->readlock); 1882 scm_recv(sock, msg, siocb->scm, flags); 1883out: 1884 return copied ? : err; 1885} 1886 1887static int unix_shutdown(struct socket *sock, int mode) 1888{ 1889 struct sock *sk = sock->sk; 1890 struct sock *other; 1891 1892 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1893 1894 if (mode) { 1895 unix_state_lock(sk); 1896 sk->sk_shutdown |= mode; 1897 other = unix_peer(sk); 1898 if (other) 1899 sock_hold(other); 1900 unix_state_unlock(sk); 1901 sk->sk_state_change(sk); 1902 1903 if (other && 1904 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1905 1906 int peer_mode = 0; 1907 1908 if (mode&RCV_SHUTDOWN) 1909 peer_mode |= SEND_SHUTDOWN; 1910 if (mode&SEND_SHUTDOWN) 1911 peer_mode |= RCV_SHUTDOWN; 1912 unix_state_lock(other); 1913 other->sk_shutdown |= peer_mode; 1914 unix_state_unlock(other); 1915 other->sk_state_change(other); 1916 read_lock(&other->sk_callback_lock); 1917 if (peer_mode == SHUTDOWN_MASK) 1918 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1919 else if (peer_mode & RCV_SHUTDOWN) 1920 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1921 read_unlock(&other->sk_callback_lock); 1922 } 1923 if (other) 1924 sock_put(other); 1925 } 1926 return 0; 1927} 1928 1929static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1930{ 1931 struct sock *sk = sock->sk; 1932 long amount = 0; 1933 int err; 1934 1935 switch (cmd) { 1936 case SIOCOUTQ: 1937 amount = atomic_read(&sk->sk_wmem_alloc); 1938 err = put_user(amount, (int __user *)arg); 1939 break; 1940 case SIOCINQ: 1941 { 1942 struct sk_buff *skb; 1943 1944 if (sk->sk_state == TCP_LISTEN) { 1945 err = -EINVAL; 1946 break; 1947 } 1948 1949 spin_lock(&sk->sk_receive_queue.lock); 1950 if (sk->sk_type == SOCK_STREAM || 1951 sk->sk_type == SOCK_SEQPACKET) { 1952 skb_queue_walk(&sk->sk_receive_queue, skb) 1953 amount += skb->len; 1954 } else { 1955 skb = skb_peek(&sk->sk_receive_queue); 1956 if (skb) 1957 amount = skb->len; 1958 } 1959 spin_unlock(&sk->sk_receive_queue.lock); 1960 err = put_user(amount, (int __user *)arg); 1961 break; 1962 } 1963 1964 default: 1965 err = -ENOIOCTLCMD; 1966 break; 1967 } 1968 return err; 1969} 1970 1971static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) 1972{ 1973 struct sock *sk = sock->sk; 1974 unsigned int mask; 1975 1976 poll_wait(file, sk->sk_sleep, wait); 1977 mask = 0; 1978 1979 /* exceptional events? */ 1980 if (sk->sk_err) 1981 mask |= POLLERR; 1982 if (sk->sk_shutdown == SHUTDOWN_MASK) 1983 mask |= POLLHUP; 1984 if (sk->sk_shutdown & RCV_SHUTDOWN) 1985 mask |= POLLRDHUP; 1986 1987 /* readable? */ 1988 if (!skb_queue_empty(&sk->sk_receive_queue) || 1989 (sk->sk_shutdown & RCV_SHUTDOWN)) 1990 mask |= POLLIN | POLLRDNORM; 1991 1992 /* Connection-based need to check for termination and startup */ 1993 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && 1994 sk->sk_state == TCP_CLOSE) 1995 mask |= POLLHUP; 1996 1997 /* 1998 * we set writable also when the other side has shut down the 1999 * connection. This prevents stuck sockets. 2000 */ 2001 if (unix_writable(sk)) 2002 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2003 2004 return mask; 2005} 2006 2007static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 2008 poll_table *wait) 2009{ 2010 struct sock *sk = sock->sk, *other; 2011 unsigned int mask, writable; 2012 2013 poll_wait(file, sk->sk_sleep, wait); 2014 mask = 0; 2015 2016 /* exceptional events? */ 2017 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2018 mask |= POLLERR; 2019 if (sk->sk_shutdown & RCV_SHUTDOWN) 2020 mask |= POLLRDHUP; 2021 if (sk->sk_shutdown == SHUTDOWN_MASK) 2022 mask |= POLLHUP; 2023 2024 /* readable? */ 2025 if (!skb_queue_empty(&sk->sk_receive_queue) || 2026 (sk->sk_shutdown & RCV_SHUTDOWN)) 2027 mask |= POLLIN | POLLRDNORM; 2028 2029 /* Connection-based need to check for termination and startup */ 2030 if (sk->sk_type == SOCK_SEQPACKET) { 2031 if (sk->sk_state == TCP_CLOSE) 2032 mask |= POLLHUP; 2033 /* connection hasn't started yet? */ 2034 if (sk->sk_state == TCP_SYN_SENT) 2035 return mask; 2036 } 2037 2038 /* writable? */ 2039 writable = unix_writable(sk); 2040 if (writable) { 2041 other = unix_peer_get(sk); 2042 if (other) { 2043 if (unix_peer(other) != sk) { 2044 poll_wait(file, &unix_sk(other)->peer_wait, 2045 wait); 2046 if (unix_recvq_full(other)) 2047 writable = 0; 2048 } 2049 2050 sock_put(other); 2051 } 2052 } 2053 2054 if (writable) 2055 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2056 else 2057 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2058 2059 return mask; 2060} 2061 2062#ifdef CONFIG_PROC_FS 2063static struct sock *first_unix_socket(int *i) 2064{ 2065 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2066 if (!hlist_empty(&unix_socket_table[*i])) 2067 return __sk_head(&unix_socket_table[*i]); 2068 } 2069 return NULL; 2070} 2071 2072static struct sock *next_unix_socket(int *i, struct sock *s) 2073{ 2074 struct sock *next = sk_next(s); 2075 /* More in this chain? */ 2076 if (next) 2077 return next; 2078 /* Look for next non-empty chain. */ 2079 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2080 if (!hlist_empty(&unix_socket_table[*i])) 2081 return __sk_head(&unix_socket_table[*i]); 2082 } 2083 return NULL; 2084} 2085 2086struct unix_iter_state { 2087 struct seq_net_private p; 2088 int i; 2089}; 2090 2091static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2092{ 2093 struct unix_iter_state *iter = seq->private; 2094 loff_t off = 0; 2095 struct sock *s; 2096 2097 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2098 if (sock_net(s) != seq_file_net(seq)) 2099 continue; 2100 if (off == pos) 2101 return s; 2102 ++off; 2103 } 2104 return NULL; 2105} 2106 2107static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2108 __acquires(unix_table_lock) 2109{ 2110 spin_lock(&unix_table_lock); 2111 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2112} 2113 2114static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2115{ 2116 struct unix_iter_state *iter = seq->private; 2117 struct sock *sk = v; 2118 ++*pos; 2119 2120 if (v == SEQ_START_TOKEN) 2121 sk = first_unix_socket(&iter->i); 2122 else 2123 sk = next_unix_socket(&iter->i, sk); 2124 while (sk && (sock_net(sk) != seq_file_net(seq))) 2125 sk = next_unix_socket(&iter->i, sk); 2126 return sk; 2127} 2128 2129static void unix_seq_stop(struct seq_file *seq, void *v) 2130 __releases(unix_table_lock) 2131{ 2132 spin_unlock(&unix_table_lock); 2133} 2134 2135static int unix_seq_show(struct seq_file *seq, void *v) 2136{ 2137 2138 if (v == SEQ_START_TOKEN) 2139 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2140 "Inode Path\n"); 2141 else { 2142 struct sock *s = v; 2143 struct unix_sock *u = unix_sk(s); 2144 unix_state_lock(s); 2145 2146 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2147 s, 2148 atomic_read(&s->sk_refcnt), 2149 0, 2150 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2151 s->sk_type, 2152 s->sk_socket ? 2153 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2154 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2155 sock_i_ino(s)); 2156 2157 if (u->addr) { 2158 int i, len; 2159 seq_putc(seq, ' '); 2160 2161 i = 0; 2162 len = u->addr->len - sizeof(short); 2163 if (!UNIX_ABSTRACT(s)) 2164 len--; 2165 else { 2166 seq_putc(seq, '@'); 2167 i++; 2168 } 2169 for ( ; i < len; i++) 2170 seq_putc(seq, u->addr->name->sun_path[i]); 2171 } 2172 unix_state_unlock(s); 2173 seq_putc(seq, '\n'); 2174 } 2175 2176 return 0; 2177} 2178 2179static const struct seq_operations unix_seq_ops = { 2180 .start = unix_seq_start, 2181 .next = unix_seq_next, 2182 .stop = unix_seq_stop, 2183 .show = unix_seq_show, 2184}; 2185 2186static int unix_seq_open(struct inode *inode, struct file *file) 2187{ 2188 return seq_open_net(inode, file, &unix_seq_ops, 2189 sizeof(struct unix_iter_state)); 2190} 2191 2192static const struct file_operations unix_seq_fops = { 2193 .owner = THIS_MODULE, 2194 .open = unix_seq_open, 2195 .read = seq_read, 2196 .llseek = seq_lseek, 2197 .release = seq_release_net, 2198}; 2199 2200#endif 2201 2202static struct net_proto_family unix_family_ops = { 2203 .family = PF_UNIX, 2204 .create = unix_create, 2205 .owner = THIS_MODULE, 2206}; 2207 2208 2209static int unix_net_init(struct net *net) 2210{ 2211 int error = -ENOMEM; 2212 2213 net->unx.sysctl_max_dgram_qlen = 10; 2214 if (unix_sysctl_register(net)) 2215 goto out; 2216 2217#ifdef CONFIG_PROC_FS 2218 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2219 unix_sysctl_unregister(net); 2220 goto out; 2221 } 2222#endif 2223 error = 0; 2224out: 2225 return error; 2226} 2227 2228static void unix_net_exit(struct net *net) 2229{ 2230 unix_sysctl_unregister(net); 2231 proc_net_remove(net, "unix"); 2232} 2233 2234static struct pernet_operations unix_net_ops = { 2235 .init = unix_net_init, 2236 .exit = unix_net_exit, 2237}; 2238 2239static int __init af_unix_init(void) 2240{ 2241 int rc = -1; 2242 struct sk_buff *dummy_skb; 2243 2244 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2245 2246 rc = proto_register(&unix_proto, 1); 2247 if (rc != 0) { 2248 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2249 __func__); 2250 goto out; 2251 } 2252 2253 sock_register(&unix_family_ops); 2254 register_pernet_subsys(&unix_net_ops); 2255out: 2256 return rc; 2257} 2258 2259static void __exit af_unix_exit(void) 2260{ 2261 sock_unregister(PF_UNIX); 2262 proto_unregister(&unix_proto); 2263 unregister_pernet_subsys(&unix_net_ops); 2264} 2265 2266/* Earlier than device_initcall() so that other drivers invoking 2267 request_module() don't end up in a loop when modprobe tries 2268 to use a UNIX socket. But later than subsys_initcall() because 2269 we depend on stuff initialised there */ 2270fs_initcall(af_unix_init); 2271module_exit(af_unix_exit); 2272 2273MODULE_LICENSE("GPL"); 2274MODULE_ALIAS_NETPROTO(PF_UNIX); 2275