af_unix.c revision 40d44446cf10d9d118e8f0132c94e1f25ea3be97
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(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_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{ 626 if (protocol && protocol != PF_UNIX) 627 return -EPROTONOSUPPORT; 628 629 sock->state = SS_UNCONNECTED; 630 631 switch (sock->type) { 632 case SOCK_STREAM: 633 sock->ops = &unix_stream_ops; 634 break; 635 /* 636 * Believe it or not BSD has AF_UNIX, SOCK_RAW though 637 * nothing uses it. 638 */ 639 case SOCK_RAW: 640 sock->type = SOCK_DGRAM; 641 case SOCK_DGRAM: 642 sock->ops = &unix_dgram_ops; 643 break; 644 case SOCK_SEQPACKET: 645 sock->ops = &unix_seqpacket_ops; 646 break; 647 default: 648 return -ESOCKTNOSUPPORT; 649 } 650 651 return unix_create1(net, sock) ? 0 : -ENOMEM; 652} 653 654static int unix_release(struct socket *sock) 655{ 656 struct sock *sk = sock->sk; 657 658 if (!sk) 659 return 0; 660 661 sock->sk = NULL; 662 663 return unix_release_sock(sk, 0); 664} 665 666static int unix_autobind(struct socket *sock) 667{ 668 struct sock *sk = sock->sk; 669 struct net *net = sock_net(sk); 670 struct unix_sock *u = unix_sk(sk); 671 static u32 ordernum = 1; 672 struct unix_address *addr; 673 int err; 674 675 mutex_lock(&u->readlock); 676 677 err = 0; 678 if (u->addr) 679 goto out; 680 681 err = -ENOMEM; 682 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); 683 if (!addr) 684 goto out; 685 686 addr->name->sun_family = AF_UNIX; 687 atomic_set(&addr->refcnt, 1); 688 689retry: 690 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); 691 addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); 692 693 spin_lock(&unix_table_lock); 694 ordernum = (ordernum+1)&0xFFFFF; 695 696 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, 697 addr->hash)) { 698 spin_unlock(&unix_table_lock); 699 /* Sanity yield. It is unusual case, but yet... */ 700 if (!(ordernum&0xFF)) 701 yield(); 702 goto retry; 703 } 704 addr->hash ^= sk->sk_type; 705 706 __unix_remove_socket(sk); 707 u->addr = addr; 708 __unix_insert_socket(&unix_socket_table[addr->hash], sk); 709 spin_unlock(&unix_table_lock); 710 err = 0; 711 712out: mutex_unlock(&u->readlock); 713 return err; 714} 715 716static struct sock *unix_find_other(struct net *net, 717 struct sockaddr_un *sunname, int len, 718 int type, unsigned hash, int *error) 719{ 720 struct sock *u; 721 struct path path; 722 int err = 0; 723 724 if (sunname->sun_path[0]) { 725 struct inode *inode; 726 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); 727 if (err) 728 goto fail; 729 inode = path.dentry->d_inode; 730 err = inode_permission(inode, MAY_WRITE); 731 if (err) 732 goto put_fail; 733 734 err = -ECONNREFUSED; 735 if (!S_ISSOCK(inode->i_mode)) 736 goto put_fail; 737 u = unix_find_socket_byinode(net, inode); 738 if (!u) 739 goto put_fail; 740 741 if (u->sk_type == type) 742 touch_atime(path.mnt, path.dentry); 743 744 path_put(&path); 745 746 err = -EPROTOTYPE; 747 if (u->sk_type != type) { 748 sock_put(u); 749 goto fail; 750 } 751 } else { 752 err = -ECONNREFUSED; 753 u = unix_find_socket_byname(net, sunname, len, type, hash); 754 if (u) { 755 struct dentry *dentry; 756 dentry = unix_sk(u)->dentry; 757 if (dentry) 758 touch_atime(unix_sk(u)->mnt, dentry); 759 } else 760 goto fail; 761 } 762 return u; 763 764put_fail: 765 path_put(&path); 766fail: 767 *error = err; 768 return NULL; 769} 770 771 772static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 773{ 774 struct sock *sk = sock->sk; 775 struct net *net = sock_net(sk); 776 struct unix_sock *u = unix_sk(sk); 777 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 778 struct dentry *dentry = NULL; 779 struct nameidata nd; 780 int err; 781 unsigned hash; 782 struct unix_address *addr; 783 struct hlist_head *list; 784 785 err = -EINVAL; 786 if (sunaddr->sun_family != AF_UNIX) 787 goto out; 788 789 if (addr_len == sizeof(short)) { 790 err = unix_autobind(sock); 791 goto out; 792 } 793 794 err = unix_mkname(sunaddr, addr_len, &hash); 795 if (err < 0) 796 goto out; 797 addr_len = err; 798 799 mutex_lock(&u->readlock); 800 801 err = -EINVAL; 802 if (u->addr) 803 goto out_up; 804 805 err = -ENOMEM; 806 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); 807 if (!addr) 808 goto out_up; 809 810 memcpy(addr->name, sunaddr, addr_len); 811 addr->len = addr_len; 812 addr->hash = hash ^ sk->sk_type; 813 atomic_set(&addr->refcnt, 1); 814 815 if (sunaddr->sun_path[0]) { 816 unsigned int mode; 817 err = 0; 818 /* 819 * Get the parent directory, calculate the hash for last 820 * component. 821 */ 822 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); 823 if (err) 824 goto out_mknod_parent; 825 826 dentry = lookup_create(&nd, 0); 827 err = PTR_ERR(dentry); 828 if (IS_ERR(dentry)) 829 goto out_mknod_unlock; 830 831 /* 832 * All right, let's create it. 833 */ 834 mode = S_IFSOCK | 835 (SOCK_INODE(sock)->i_mode & ~current->fs->umask); 836 err = mnt_want_write(nd.path.mnt); 837 if (err) 838 goto out_mknod_dput; 839 err = security_path_mknod(&nd.path, dentry, mode, 0); 840 if (err) 841 goto out_mknod_drop_write; 842 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); 843out_mknod_drop_write: 844 mnt_drop_write(nd.path.mnt); 845 if (err) 846 goto out_mknod_dput; 847 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 848 dput(nd.path.dentry); 849 nd.path.dentry = dentry; 850 851 addr->hash = UNIX_HASH_SIZE; 852 } 853 854 spin_lock(&unix_table_lock); 855 856 if (!sunaddr->sun_path[0]) { 857 err = -EADDRINUSE; 858 if (__unix_find_socket_byname(net, sunaddr, addr_len, 859 sk->sk_type, hash)) { 860 unix_release_addr(addr); 861 goto out_unlock; 862 } 863 864 list = &unix_socket_table[addr->hash]; 865 } else { 866 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; 867 u->dentry = nd.path.dentry; 868 u->mnt = nd.path.mnt; 869 } 870 871 err = 0; 872 __unix_remove_socket(sk); 873 u->addr = addr; 874 __unix_insert_socket(list, sk); 875 876out_unlock: 877 spin_unlock(&unix_table_lock); 878out_up: 879 mutex_unlock(&u->readlock); 880out: 881 return err; 882 883out_mknod_dput: 884 dput(dentry); 885out_mknod_unlock: 886 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 887 path_put(&nd.path); 888out_mknod_parent: 889 if (err == -EEXIST) 890 err = -EADDRINUSE; 891 unix_release_addr(addr); 892 goto out_up; 893} 894 895static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) 896{ 897 if (unlikely(sk1 == sk2) || !sk2) { 898 unix_state_lock(sk1); 899 return; 900 } 901 if (sk1 < sk2) { 902 unix_state_lock(sk1); 903 unix_state_lock_nested(sk2); 904 } else { 905 unix_state_lock(sk2); 906 unix_state_lock_nested(sk1); 907 } 908} 909 910static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) 911{ 912 if (unlikely(sk1 == sk2) || !sk2) { 913 unix_state_unlock(sk1); 914 return; 915 } 916 unix_state_unlock(sk1); 917 unix_state_unlock(sk2); 918} 919 920static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 921 int alen, int flags) 922{ 923 struct sock *sk = sock->sk; 924 struct net *net = sock_net(sk); 925 struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; 926 struct sock *other; 927 unsigned hash; 928 int err; 929 930 if (addr->sa_family != AF_UNSPEC) { 931 err = unix_mkname(sunaddr, alen, &hash); 932 if (err < 0) 933 goto out; 934 alen = err; 935 936 if (test_bit(SOCK_PASSCRED, &sock->flags) && 937 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) 938 goto out; 939 940restart: 941 other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); 942 if (!other) 943 goto out; 944 945 unix_state_double_lock(sk, other); 946 947 /* Apparently VFS overslept socket death. Retry. */ 948 if (sock_flag(other, SOCK_DEAD)) { 949 unix_state_double_unlock(sk, other); 950 sock_put(other); 951 goto restart; 952 } 953 954 err = -EPERM; 955 if (!unix_may_send(sk, other)) 956 goto out_unlock; 957 958 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 959 if (err) 960 goto out_unlock; 961 962 } else { 963 /* 964 * 1003.1g breaking connected state with AF_UNSPEC 965 */ 966 other = NULL; 967 unix_state_double_lock(sk, other); 968 } 969 970 /* 971 * If it was connected, reconnect. 972 */ 973 if (unix_peer(sk)) { 974 struct sock *old_peer = unix_peer(sk); 975 unix_peer(sk) = other; 976 unix_state_double_unlock(sk, other); 977 978 if (other != old_peer) 979 unix_dgram_disconnected(sk, old_peer); 980 sock_put(old_peer); 981 } else { 982 unix_peer(sk) = other; 983 unix_state_double_unlock(sk, other); 984 } 985 return 0; 986 987out_unlock: 988 unix_state_double_unlock(sk, other); 989 sock_put(other); 990out: 991 return err; 992} 993 994static long unix_wait_for_peer(struct sock *other, long timeo) 995{ 996 struct unix_sock *u = unix_sk(other); 997 int sched; 998 DEFINE_WAIT(wait); 999 1000 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); 1001 1002 sched = !sock_flag(other, SOCK_DEAD) && 1003 !(other->sk_shutdown & RCV_SHUTDOWN) && 1004 unix_recvq_full(other); 1005 1006 unix_state_unlock(other); 1007 1008 if (sched) 1009 timeo = schedule_timeout(timeo); 1010 1011 finish_wait(&u->peer_wait, &wait); 1012 return timeo; 1013} 1014 1015static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, 1016 int addr_len, int flags) 1017{ 1018 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 1019 struct sock *sk = sock->sk; 1020 struct net *net = sock_net(sk); 1021 struct unix_sock *u = unix_sk(sk), *newu, *otheru; 1022 struct sock *newsk = NULL; 1023 struct sock *other = NULL; 1024 struct sk_buff *skb = NULL; 1025 unsigned hash; 1026 int st; 1027 int err; 1028 long timeo; 1029 1030 err = unix_mkname(sunaddr, addr_len, &hash); 1031 if (err < 0) 1032 goto out; 1033 addr_len = err; 1034 1035 if (test_bit(SOCK_PASSCRED, &sock->flags) 1036 && !u->addr && (err = unix_autobind(sock)) != 0) 1037 goto out; 1038 1039 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 1040 1041 /* First of all allocate resources. 1042 If we will make it after state is locked, 1043 we will have to recheck all again in any case. 1044 */ 1045 1046 err = -ENOMEM; 1047 1048 /* create new sock for complete connection */ 1049 newsk = unix_create1(sock_net(sk), NULL); 1050 if (newsk == NULL) 1051 goto out; 1052 1053 /* Allocate skb for sending to listening sock */ 1054 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); 1055 if (skb == NULL) 1056 goto out; 1057 1058restart: 1059 /* Find listening sock. */ 1060 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); 1061 if (!other) 1062 goto out; 1063 1064 /* Latch state of peer */ 1065 unix_state_lock(other); 1066 1067 /* Apparently VFS overslept socket death. Retry. */ 1068 if (sock_flag(other, SOCK_DEAD)) { 1069 unix_state_unlock(other); 1070 sock_put(other); 1071 goto restart; 1072 } 1073 1074 err = -ECONNREFUSED; 1075 if (other->sk_state != TCP_LISTEN) 1076 goto out_unlock; 1077 1078 if (unix_recvq_full(other)) { 1079 err = -EAGAIN; 1080 if (!timeo) 1081 goto out_unlock; 1082 1083 timeo = unix_wait_for_peer(other, timeo); 1084 1085 err = sock_intr_errno(timeo); 1086 if (signal_pending(current)) 1087 goto out; 1088 sock_put(other); 1089 goto restart; 1090 } 1091 1092 /* Latch our state. 1093 1094 It is tricky place. We need to grab write lock and cannot 1095 drop lock on peer. It is dangerous because deadlock is 1096 possible. Connect to self case and simultaneous 1097 attempt to connect are eliminated by checking socket 1098 state. other is TCP_LISTEN, if sk is TCP_LISTEN we 1099 check this before attempt to grab lock. 1100 1101 Well, and we have to recheck the state after socket locked. 1102 */ 1103 st = sk->sk_state; 1104 1105 switch (st) { 1106 case TCP_CLOSE: 1107 /* This is ok... continue with connect */ 1108 break; 1109 case TCP_ESTABLISHED: 1110 /* Socket is already connected */ 1111 err = -EISCONN; 1112 goto out_unlock; 1113 default: 1114 err = -EINVAL; 1115 goto out_unlock; 1116 } 1117 1118 unix_state_lock_nested(sk); 1119 1120 if (sk->sk_state != st) { 1121 unix_state_unlock(sk); 1122 unix_state_unlock(other); 1123 sock_put(other); 1124 goto restart; 1125 } 1126 1127 err = security_unix_stream_connect(sock, other->sk_socket, newsk); 1128 if (err) { 1129 unix_state_unlock(sk); 1130 goto out_unlock; 1131 } 1132 1133 /* The way is open! Fastly set all the necessary fields... */ 1134 1135 sock_hold(sk); 1136 unix_peer(newsk) = sk; 1137 newsk->sk_state = TCP_ESTABLISHED; 1138 newsk->sk_type = sk->sk_type; 1139 newsk->sk_peercred.pid = task_tgid_vnr(current); 1140 current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid); 1141 newu = unix_sk(newsk); 1142 newsk->sk_sleep = &newu->peer_wait; 1143 otheru = unix_sk(other); 1144 1145 /* copy address information from listening to new sock*/ 1146 if (otheru->addr) { 1147 atomic_inc(&otheru->addr->refcnt); 1148 newu->addr = otheru->addr; 1149 } 1150 if (otheru->dentry) { 1151 newu->dentry = dget(otheru->dentry); 1152 newu->mnt = mntget(otheru->mnt); 1153 } 1154 1155 /* Set credentials */ 1156 sk->sk_peercred = other->sk_peercred; 1157 1158 sock->state = SS_CONNECTED; 1159 sk->sk_state = TCP_ESTABLISHED; 1160 sock_hold(newsk); 1161 1162 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ 1163 unix_peer(sk) = newsk; 1164 1165 unix_state_unlock(sk); 1166 1167 /* take ten and and send info to listening sock */ 1168 spin_lock(&other->sk_receive_queue.lock); 1169 __skb_queue_tail(&other->sk_receive_queue, skb); 1170 spin_unlock(&other->sk_receive_queue.lock); 1171 unix_state_unlock(other); 1172 other->sk_data_ready(other, 0); 1173 sock_put(other); 1174 return 0; 1175 1176out_unlock: 1177 if (other) 1178 unix_state_unlock(other); 1179 1180out: 1181 kfree_skb(skb); 1182 if (newsk) 1183 unix_release_sock(newsk, 0); 1184 if (other) 1185 sock_put(other); 1186 return err; 1187} 1188 1189static int unix_socketpair(struct socket *socka, struct socket *sockb) 1190{ 1191 struct sock *ska = socka->sk, *skb = sockb->sk; 1192 1193 /* Join our sockets back to back */ 1194 sock_hold(ska); 1195 sock_hold(skb); 1196 unix_peer(ska) = skb; 1197 unix_peer(skb) = ska; 1198 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current); 1199 current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid); 1200 ska->sk_peercred.uid = skb->sk_peercred.uid; 1201 ska->sk_peercred.gid = skb->sk_peercred.gid; 1202 1203 if (ska->sk_type != SOCK_DGRAM) { 1204 ska->sk_state = TCP_ESTABLISHED; 1205 skb->sk_state = TCP_ESTABLISHED; 1206 socka->state = SS_CONNECTED; 1207 sockb->state = SS_CONNECTED; 1208 } 1209 return 0; 1210} 1211 1212static int unix_accept(struct socket *sock, struct socket *newsock, int flags) 1213{ 1214 struct sock *sk = sock->sk; 1215 struct sock *tsk; 1216 struct sk_buff *skb; 1217 int err; 1218 1219 err = -EOPNOTSUPP; 1220 if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) 1221 goto out; 1222 1223 err = -EINVAL; 1224 if (sk->sk_state != TCP_LISTEN) 1225 goto out; 1226 1227 /* If socket state is TCP_LISTEN it cannot change (for now...), 1228 * so that no locks are necessary. 1229 */ 1230 1231 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); 1232 if (!skb) { 1233 /* This means receive shutdown. */ 1234 if (err == 0) 1235 err = -EINVAL; 1236 goto out; 1237 } 1238 1239 tsk = skb->sk; 1240 skb_free_datagram(sk, skb); 1241 wake_up_interruptible(&unix_sk(sk)->peer_wait); 1242 1243 /* attach accepted sock to socket */ 1244 unix_state_lock(tsk); 1245 newsock->state = SS_CONNECTED; 1246 sock_graft(tsk, newsock); 1247 unix_state_unlock(tsk); 1248 return 0; 1249 1250out: 1251 return err; 1252} 1253 1254 1255static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) 1256{ 1257 struct sock *sk = sock->sk; 1258 struct unix_sock *u; 1259 struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; 1260 int err = 0; 1261 1262 if (peer) { 1263 sk = unix_peer_get(sk); 1264 1265 err = -ENOTCONN; 1266 if (!sk) 1267 goto out; 1268 err = 0; 1269 } else { 1270 sock_hold(sk); 1271 } 1272 1273 u = unix_sk(sk); 1274 unix_state_lock(sk); 1275 if (!u->addr) { 1276 sunaddr->sun_family = AF_UNIX; 1277 sunaddr->sun_path[0] = 0; 1278 *uaddr_len = sizeof(short); 1279 } else { 1280 struct unix_address *addr = u->addr; 1281 1282 *uaddr_len = addr->len; 1283 memcpy(sunaddr, addr->name, *uaddr_len); 1284 } 1285 unix_state_unlock(sk); 1286 sock_put(sk); 1287out: 1288 return err; 1289} 1290 1291static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1292{ 1293 int i; 1294 1295 scm->fp = UNIXCB(skb).fp; 1296 skb->destructor = sock_wfree; 1297 UNIXCB(skb).fp = NULL; 1298 1299 for (i = scm->fp->count-1; i >= 0; i--) 1300 unix_notinflight(scm->fp->fp[i]); 1301} 1302 1303static void unix_destruct_fds(struct sk_buff *skb) 1304{ 1305 struct scm_cookie scm; 1306 memset(&scm, 0, sizeof(scm)); 1307 unix_detach_fds(&scm, skb); 1308 1309 /* Alas, it calls VFS */ 1310 /* So fscking what? fput() had been SMP-safe since the last Summer */ 1311 scm_destroy(&scm); 1312 sock_wfree(skb); 1313} 1314 1315static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1316{ 1317 int i; 1318 1319 /* 1320 * Need to duplicate file references for the sake of garbage 1321 * collection. Otherwise a socket in the fps might become a 1322 * candidate for GC while the skb is not yet queued. 1323 */ 1324 UNIXCB(skb).fp = scm_fp_dup(scm->fp); 1325 if (!UNIXCB(skb).fp) 1326 return -ENOMEM; 1327 1328 for (i = scm->fp->count-1; i >= 0; i--) 1329 unix_inflight(scm->fp->fp[i]); 1330 skb->destructor = unix_destruct_fds; 1331 return 0; 1332} 1333 1334/* 1335 * Send AF_UNIX data. 1336 */ 1337 1338static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 1339 struct msghdr *msg, size_t len) 1340{ 1341 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1342 struct sock *sk = sock->sk; 1343 struct net *net = sock_net(sk); 1344 struct unix_sock *u = unix_sk(sk); 1345 struct sockaddr_un *sunaddr = msg->msg_name; 1346 struct sock *other = NULL; 1347 int namelen = 0; /* fake GCC */ 1348 int err; 1349 unsigned hash; 1350 struct sk_buff *skb; 1351 long timeo; 1352 struct scm_cookie tmp_scm; 1353 1354 if (NULL == siocb->scm) 1355 siocb->scm = &tmp_scm; 1356 wait_for_unix_gc(); 1357 err = scm_send(sock, msg, siocb->scm); 1358 if (err < 0) 1359 return err; 1360 1361 err = -EOPNOTSUPP; 1362 if (msg->msg_flags&MSG_OOB) 1363 goto out; 1364 1365 if (msg->msg_namelen) { 1366 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1367 if (err < 0) 1368 goto out; 1369 namelen = err; 1370 } else { 1371 sunaddr = NULL; 1372 err = -ENOTCONN; 1373 other = unix_peer_get(sk); 1374 if (!other) 1375 goto out; 1376 } 1377 1378 if (test_bit(SOCK_PASSCRED, &sock->flags) 1379 && !u->addr && (err = unix_autobind(sock)) != 0) 1380 goto out; 1381 1382 err = -EMSGSIZE; 1383 if (len > sk->sk_sndbuf - 32) 1384 goto out; 1385 1386 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1387 if (skb == NULL) 1388 goto out; 1389 1390 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1391 if (siocb->scm->fp) { 1392 err = unix_attach_fds(siocb->scm, skb); 1393 if (err) 1394 goto out_free; 1395 } 1396 unix_get_secdata(siocb->scm, skb); 1397 1398 skb_reset_transport_header(skb); 1399 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1400 if (err) 1401 goto out_free; 1402 1403 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1404 1405restart: 1406 if (!other) { 1407 err = -ECONNRESET; 1408 if (sunaddr == NULL) 1409 goto out_free; 1410 1411 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1412 hash, &err); 1413 if (other == NULL) 1414 goto out_free; 1415 } 1416 1417 unix_state_lock(other); 1418 err = -EPERM; 1419 if (!unix_may_send(sk, other)) 1420 goto out_unlock; 1421 1422 if (sock_flag(other, SOCK_DEAD)) { 1423 /* 1424 * Check with 1003.1g - what should 1425 * datagram error 1426 */ 1427 unix_state_unlock(other); 1428 sock_put(other); 1429 1430 err = 0; 1431 unix_state_lock(sk); 1432 if (unix_peer(sk) == other) { 1433 unix_peer(sk) = NULL; 1434 unix_state_unlock(sk); 1435 1436 unix_dgram_disconnected(sk, other); 1437 sock_put(other); 1438 err = -ECONNREFUSED; 1439 } else { 1440 unix_state_unlock(sk); 1441 } 1442 1443 other = NULL; 1444 if (err) 1445 goto out_free; 1446 goto restart; 1447 } 1448 1449 err = -EPIPE; 1450 if (other->sk_shutdown & RCV_SHUTDOWN) 1451 goto out_unlock; 1452 1453 if (sk->sk_type != SOCK_SEQPACKET) { 1454 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1455 if (err) 1456 goto out_unlock; 1457 } 1458 1459 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1460 if (!timeo) { 1461 err = -EAGAIN; 1462 goto out_unlock; 1463 } 1464 1465 timeo = unix_wait_for_peer(other, timeo); 1466 1467 err = sock_intr_errno(timeo); 1468 if (signal_pending(current)) 1469 goto out_free; 1470 1471 goto restart; 1472 } 1473 1474 skb_queue_tail(&other->sk_receive_queue, skb); 1475 unix_state_unlock(other); 1476 other->sk_data_ready(other, len); 1477 sock_put(other); 1478 scm_destroy(siocb->scm); 1479 return len; 1480 1481out_unlock: 1482 unix_state_unlock(other); 1483out_free: 1484 kfree_skb(skb); 1485out: 1486 if (other) 1487 sock_put(other); 1488 scm_destroy(siocb->scm); 1489 return err; 1490} 1491 1492 1493static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1494 struct msghdr *msg, size_t len) 1495{ 1496 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1497 struct sock *sk = sock->sk; 1498 struct sock *other = NULL; 1499 struct sockaddr_un *sunaddr = msg->msg_name; 1500 int err, size; 1501 struct sk_buff *skb; 1502 int sent = 0; 1503 struct scm_cookie tmp_scm; 1504 1505 if (NULL == siocb->scm) 1506 siocb->scm = &tmp_scm; 1507 wait_for_unix_gc(); 1508 err = scm_send(sock, msg, siocb->scm); 1509 if (err < 0) 1510 return err; 1511 1512 err = -EOPNOTSUPP; 1513 if (msg->msg_flags&MSG_OOB) 1514 goto out_err; 1515 1516 if (msg->msg_namelen) { 1517 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1518 goto out_err; 1519 } else { 1520 sunaddr = NULL; 1521 err = -ENOTCONN; 1522 other = unix_peer(sk); 1523 if (!other) 1524 goto out_err; 1525 } 1526 1527 if (sk->sk_shutdown & SEND_SHUTDOWN) 1528 goto pipe_err; 1529 1530 while (sent < len) { 1531 /* 1532 * Optimisation for the fact that under 0.01% of X 1533 * messages typically need breaking up. 1534 */ 1535 1536 size = len-sent; 1537 1538 /* Keep two messages in the pipe so it schedules better */ 1539 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1540 size = (sk->sk_sndbuf >> 1) - 64; 1541 1542 if (size > SKB_MAX_ALLOC) 1543 size = SKB_MAX_ALLOC; 1544 1545 /* 1546 * Grab a buffer 1547 */ 1548 1549 skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, 1550 &err); 1551 1552 if (skb == NULL) 1553 goto out_err; 1554 1555 /* 1556 * If you pass two values to the sock_alloc_send_skb 1557 * it tries to grab the large buffer with GFP_NOFS 1558 * (which can fail easily), and if it fails grab the 1559 * fallback size buffer which is under a page and will 1560 * succeed. [Alan] 1561 */ 1562 size = min_t(int, size, skb_tailroom(skb)); 1563 1564 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1565 if (siocb->scm->fp) { 1566 err = unix_attach_fds(siocb->scm, skb); 1567 if (err) { 1568 kfree_skb(skb); 1569 goto out_err; 1570 } 1571 } 1572 1573 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 1574 if (err) { 1575 kfree_skb(skb); 1576 goto out_err; 1577 } 1578 1579 unix_state_lock(other); 1580 1581 if (sock_flag(other, SOCK_DEAD) || 1582 (other->sk_shutdown & RCV_SHUTDOWN)) 1583 goto pipe_err_free; 1584 1585 skb_queue_tail(&other->sk_receive_queue, skb); 1586 unix_state_unlock(other); 1587 other->sk_data_ready(other, size); 1588 sent += size; 1589 } 1590 1591 scm_destroy(siocb->scm); 1592 siocb->scm = NULL; 1593 1594 return sent; 1595 1596pipe_err_free: 1597 unix_state_unlock(other); 1598 kfree_skb(skb); 1599pipe_err: 1600 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1601 send_sig(SIGPIPE, current, 0); 1602 err = -EPIPE; 1603out_err: 1604 scm_destroy(siocb->scm); 1605 siocb->scm = NULL; 1606 return sent ? : err; 1607} 1608 1609static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1610 struct msghdr *msg, size_t len) 1611{ 1612 int err; 1613 struct sock *sk = sock->sk; 1614 1615 err = sock_error(sk); 1616 if (err) 1617 return err; 1618 1619 if (sk->sk_state != TCP_ESTABLISHED) 1620 return -ENOTCONN; 1621 1622 if (msg->msg_namelen) 1623 msg->msg_namelen = 0; 1624 1625 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1626} 1627 1628static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1629{ 1630 struct unix_sock *u = unix_sk(sk); 1631 1632 msg->msg_namelen = 0; 1633 if (u->addr) { 1634 msg->msg_namelen = u->addr->len; 1635 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1636 } 1637} 1638 1639static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1640 struct msghdr *msg, size_t size, 1641 int flags) 1642{ 1643 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1644 struct scm_cookie tmp_scm; 1645 struct sock *sk = sock->sk; 1646 struct unix_sock *u = unix_sk(sk); 1647 int noblock = flags & MSG_DONTWAIT; 1648 struct sk_buff *skb; 1649 int err; 1650 1651 err = -EOPNOTSUPP; 1652 if (flags&MSG_OOB) 1653 goto out; 1654 1655 msg->msg_namelen = 0; 1656 1657 mutex_lock(&u->readlock); 1658 1659 skb = skb_recv_datagram(sk, flags, noblock, &err); 1660 if (!skb) { 1661 unix_state_lock(sk); 1662 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1663 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1664 (sk->sk_shutdown & RCV_SHUTDOWN)) 1665 err = 0; 1666 unix_state_unlock(sk); 1667 goto out_unlock; 1668 } 1669 1670 wake_up_interruptible_sync(&u->peer_wait); 1671 1672 if (msg->msg_name) 1673 unix_copy_addr(msg, skb->sk); 1674 1675 if (size > skb->len) 1676 size = skb->len; 1677 else if (size < skb->len) 1678 msg->msg_flags |= MSG_TRUNC; 1679 1680 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1681 if (err) 1682 goto out_free; 1683 1684 if (!siocb->scm) { 1685 siocb->scm = &tmp_scm; 1686 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1687 } 1688 siocb->scm->creds = *UNIXCREDS(skb); 1689 unix_set_secdata(siocb->scm, skb); 1690 1691 if (!(flags & MSG_PEEK)) { 1692 if (UNIXCB(skb).fp) 1693 unix_detach_fds(siocb->scm, skb); 1694 } else { 1695 /* It is questionable: on PEEK we could: 1696 - do not return fds - good, but too simple 8) 1697 - return fds, and do not return them on read (old strategy, 1698 apparently wrong) 1699 - clone fds (I chose it for now, it is the most universal 1700 solution) 1701 1702 POSIX 1003.1g does not actually define this clearly 1703 at all. POSIX 1003.1g doesn't define a lot of things 1704 clearly however! 1705 1706 */ 1707 if (UNIXCB(skb).fp) 1708 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1709 } 1710 err = size; 1711 1712 scm_recv(sock, msg, siocb->scm, flags); 1713 1714out_free: 1715 skb_free_datagram(sk, skb); 1716out_unlock: 1717 mutex_unlock(&u->readlock); 1718out: 1719 return err; 1720} 1721 1722/* 1723 * Sleep until data has arrive. But check for races.. 1724 */ 1725 1726static long unix_stream_data_wait(struct sock *sk, long timeo) 1727{ 1728 DEFINE_WAIT(wait); 1729 1730 unix_state_lock(sk); 1731 1732 for (;;) { 1733 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1734 1735 if (!skb_queue_empty(&sk->sk_receive_queue) || 1736 sk->sk_err || 1737 (sk->sk_shutdown & RCV_SHUTDOWN) || 1738 signal_pending(current) || 1739 !timeo) 1740 break; 1741 1742 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1743 unix_state_unlock(sk); 1744 timeo = schedule_timeout(timeo); 1745 unix_state_lock(sk); 1746 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1747 } 1748 1749 finish_wait(sk->sk_sleep, &wait); 1750 unix_state_unlock(sk); 1751 return timeo; 1752} 1753 1754 1755 1756static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1757 struct msghdr *msg, size_t size, 1758 int flags) 1759{ 1760 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1761 struct scm_cookie tmp_scm; 1762 struct sock *sk = sock->sk; 1763 struct unix_sock *u = unix_sk(sk); 1764 struct sockaddr_un *sunaddr = msg->msg_name; 1765 int copied = 0; 1766 int check_creds = 0; 1767 int target; 1768 int err = 0; 1769 long timeo; 1770 1771 err = -EINVAL; 1772 if (sk->sk_state != TCP_ESTABLISHED) 1773 goto out; 1774 1775 err = -EOPNOTSUPP; 1776 if (flags&MSG_OOB) 1777 goto out; 1778 1779 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1780 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1781 1782 msg->msg_namelen = 0; 1783 1784 /* Lock the socket to prevent queue disordering 1785 * while sleeps in memcpy_tomsg 1786 */ 1787 1788 if (!siocb->scm) { 1789 siocb->scm = &tmp_scm; 1790 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1791 } 1792 1793 mutex_lock(&u->readlock); 1794 1795 do { 1796 int chunk; 1797 struct sk_buff *skb; 1798 1799 unix_state_lock(sk); 1800 skb = skb_dequeue(&sk->sk_receive_queue); 1801 if (skb == NULL) { 1802 if (copied >= target) 1803 goto unlock; 1804 1805 /* 1806 * POSIX 1003.1g mandates this order. 1807 */ 1808 1809 err = sock_error(sk); 1810 if (err) 1811 goto unlock; 1812 if (sk->sk_shutdown & RCV_SHUTDOWN) 1813 goto unlock; 1814 1815 unix_state_unlock(sk); 1816 err = -EAGAIN; 1817 if (!timeo) 1818 break; 1819 mutex_unlock(&u->readlock); 1820 1821 timeo = unix_stream_data_wait(sk, timeo); 1822 1823 if (signal_pending(current)) { 1824 err = sock_intr_errno(timeo); 1825 goto out; 1826 } 1827 mutex_lock(&u->readlock); 1828 continue; 1829 unlock: 1830 unix_state_unlock(sk); 1831 break; 1832 } 1833 unix_state_unlock(sk); 1834 1835 if (check_creds) { 1836 /* Never glue messages from different writers */ 1837 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, 1838 sizeof(siocb->scm->creds)) != 0) { 1839 skb_queue_head(&sk->sk_receive_queue, skb); 1840 break; 1841 } 1842 } else { 1843 /* Copy credentials */ 1844 siocb->scm->creds = *UNIXCREDS(skb); 1845 check_creds = 1; 1846 } 1847 1848 /* Copy address just once */ 1849 if (sunaddr) { 1850 unix_copy_addr(msg, skb->sk); 1851 sunaddr = NULL; 1852 } 1853 1854 chunk = min_t(unsigned int, skb->len, size); 1855 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1856 skb_queue_head(&sk->sk_receive_queue, skb); 1857 if (copied == 0) 1858 copied = -EFAULT; 1859 break; 1860 } 1861 copied += chunk; 1862 size -= chunk; 1863 1864 /* Mark read part of skb as used */ 1865 if (!(flags & MSG_PEEK)) { 1866 skb_pull(skb, chunk); 1867 1868 if (UNIXCB(skb).fp) 1869 unix_detach_fds(siocb->scm, skb); 1870 1871 /* put the skb back if we didn't use it up.. */ 1872 if (skb->len) { 1873 skb_queue_head(&sk->sk_receive_queue, skb); 1874 break; 1875 } 1876 1877 kfree_skb(skb); 1878 1879 if (siocb->scm->fp) 1880 break; 1881 } else { 1882 /* It is questionable, see note in unix_dgram_recvmsg. 1883 */ 1884 if (UNIXCB(skb).fp) 1885 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1886 1887 /* put message back and return */ 1888 skb_queue_head(&sk->sk_receive_queue, skb); 1889 break; 1890 } 1891 } while (size); 1892 1893 mutex_unlock(&u->readlock); 1894 scm_recv(sock, msg, siocb->scm, flags); 1895out: 1896 return copied ? : err; 1897} 1898 1899static int unix_shutdown(struct socket *sock, int mode) 1900{ 1901 struct sock *sk = sock->sk; 1902 struct sock *other; 1903 1904 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1905 1906 if (mode) { 1907 unix_state_lock(sk); 1908 sk->sk_shutdown |= mode; 1909 other = unix_peer(sk); 1910 if (other) 1911 sock_hold(other); 1912 unix_state_unlock(sk); 1913 sk->sk_state_change(sk); 1914 1915 if (other && 1916 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1917 1918 int peer_mode = 0; 1919 1920 if (mode&RCV_SHUTDOWN) 1921 peer_mode |= SEND_SHUTDOWN; 1922 if (mode&SEND_SHUTDOWN) 1923 peer_mode |= RCV_SHUTDOWN; 1924 unix_state_lock(other); 1925 other->sk_shutdown |= peer_mode; 1926 unix_state_unlock(other); 1927 other->sk_state_change(other); 1928 read_lock(&other->sk_callback_lock); 1929 if (peer_mode == SHUTDOWN_MASK) 1930 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1931 else if (peer_mode & RCV_SHUTDOWN) 1932 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1933 read_unlock(&other->sk_callback_lock); 1934 } 1935 if (other) 1936 sock_put(other); 1937 } 1938 return 0; 1939} 1940 1941static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1942{ 1943 struct sock *sk = sock->sk; 1944 long amount = 0; 1945 int err; 1946 1947 switch (cmd) { 1948 case SIOCOUTQ: 1949 amount = atomic_read(&sk->sk_wmem_alloc); 1950 err = put_user(amount, (int __user *)arg); 1951 break; 1952 case SIOCINQ: 1953 { 1954 struct sk_buff *skb; 1955 1956 if (sk->sk_state == TCP_LISTEN) { 1957 err = -EINVAL; 1958 break; 1959 } 1960 1961 spin_lock(&sk->sk_receive_queue.lock); 1962 if (sk->sk_type == SOCK_STREAM || 1963 sk->sk_type == SOCK_SEQPACKET) { 1964 skb_queue_walk(&sk->sk_receive_queue, skb) 1965 amount += skb->len; 1966 } else { 1967 skb = skb_peek(&sk->sk_receive_queue); 1968 if (skb) 1969 amount = skb->len; 1970 } 1971 spin_unlock(&sk->sk_receive_queue.lock); 1972 err = put_user(amount, (int __user *)arg); 1973 break; 1974 } 1975 1976 default: 1977 err = -ENOIOCTLCMD; 1978 break; 1979 } 1980 return err; 1981} 1982 1983static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) 1984{ 1985 struct sock *sk = sock->sk; 1986 unsigned int mask; 1987 1988 poll_wait(file, sk->sk_sleep, wait); 1989 mask = 0; 1990 1991 /* exceptional events? */ 1992 if (sk->sk_err) 1993 mask |= POLLERR; 1994 if (sk->sk_shutdown == SHUTDOWN_MASK) 1995 mask |= POLLHUP; 1996 if (sk->sk_shutdown & RCV_SHUTDOWN) 1997 mask |= POLLRDHUP; 1998 1999 /* readable? */ 2000 if (!skb_queue_empty(&sk->sk_receive_queue) || 2001 (sk->sk_shutdown & RCV_SHUTDOWN)) 2002 mask |= POLLIN | POLLRDNORM; 2003 2004 /* Connection-based need to check for termination and startup */ 2005 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && 2006 sk->sk_state == TCP_CLOSE) 2007 mask |= POLLHUP; 2008 2009 /* 2010 * we set writable also when the other side has shut down the 2011 * connection. This prevents stuck sockets. 2012 */ 2013 if (unix_writable(sk)) 2014 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2015 2016 return mask; 2017} 2018 2019static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 2020 poll_table *wait) 2021{ 2022 struct sock *sk = sock->sk, *other; 2023 unsigned int mask, writable; 2024 2025 poll_wait(file, sk->sk_sleep, wait); 2026 mask = 0; 2027 2028 /* exceptional events? */ 2029 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2030 mask |= POLLERR; 2031 if (sk->sk_shutdown & RCV_SHUTDOWN) 2032 mask |= POLLRDHUP; 2033 if (sk->sk_shutdown == SHUTDOWN_MASK) 2034 mask |= POLLHUP; 2035 2036 /* readable? */ 2037 if (!skb_queue_empty(&sk->sk_receive_queue) || 2038 (sk->sk_shutdown & RCV_SHUTDOWN)) 2039 mask |= POLLIN | POLLRDNORM; 2040 2041 /* Connection-based need to check for termination and startup */ 2042 if (sk->sk_type == SOCK_SEQPACKET) { 2043 if (sk->sk_state == TCP_CLOSE) 2044 mask |= POLLHUP; 2045 /* connection hasn't started yet? */ 2046 if (sk->sk_state == TCP_SYN_SENT) 2047 return mask; 2048 } 2049 2050 /* writable? */ 2051 writable = unix_writable(sk); 2052 if (writable) { 2053 other = unix_peer_get(sk); 2054 if (other) { 2055 if (unix_peer(other) != sk) { 2056 poll_wait(file, &unix_sk(other)->peer_wait, 2057 wait); 2058 if (unix_recvq_full(other)) 2059 writable = 0; 2060 } 2061 2062 sock_put(other); 2063 } 2064 } 2065 2066 if (writable) 2067 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2068 else 2069 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2070 2071 return mask; 2072} 2073 2074#ifdef CONFIG_PROC_FS 2075static struct sock *first_unix_socket(int *i) 2076{ 2077 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2078 if (!hlist_empty(&unix_socket_table[*i])) 2079 return __sk_head(&unix_socket_table[*i]); 2080 } 2081 return NULL; 2082} 2083 2084static struct sock *next_unix_socket(int *i, struct sock *s) 2085{ 2086 struct sock *next = sk_next(s); 2087 /* More in this chain? */ 2088 if (next) 2089 return next; 2090 /* Look for next non-empty chain. */ 2091 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2092 if (!hlist_empty(&unix_socket_table[*i])) 2093 return __sk_head(&unix_socket_table[*i]); 2094 } 2095 return NULL; 2096} 2097 2098struct unix_iter_state { 2099 struct seq_net_private p; 2100 int i; 2101}; 2102 2103static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2104{ 2105 struct unix_iter_state *iter = seq->private; 2106 loff_t off = 0; 2107 struct sock *s; 2108 2109 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2110 if (sock_net(s) != seq_file_net(seq)) 2111 continue; 2112 if (off == pos) 2113 return s; 2114 ++off; 2115 } 2116 return NULL; 2117} 2118 2119static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2120 __acquires(unix_table_lock) 2121{ 2122 spin_lock(&unix_table_lock); 2123 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2124} 2125 2126static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2127{ 2128 struct unix_iter_state *iter = seq->private; 2129 struct sock *sk = v; 2130 ++*pos; 2131 2132 if (v == SEQ_START_TOKEN) 2133 sk = first_unix_socket(&iter->i); 2134 else 2135 sk = next_unix_socket(&iter->i, sk); 2136 while (sk && (sock_net(sk) != seq_file_net(seq))) 2137 sk = next_unix_socket(&iter->i, sk); 2138 return sk; 2139} 2140 2141static void unix_seq_stop(struct seq_file *seq, void *v) 2142 __releases(unix_table_lock) 2143{ 2144 spin_unlock(&unix_table_lock); 2145} 2146 2147static int unix_seq_show(struct seq_file *seq, void *v) 2148{ 2149 2150 if (v == SEQ_START_TOKEN) 2151 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2152 "Inode Path\n"); 2153 else { 2154 struct sock *s = v; 2155 struct unix_sock *u = unix_sk(s); 2156 unix_state_lock(s); 2157 2158 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2159 s, 2160 atomic_read(&s->sk_refcnt), 2161 0, 2162 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2163 s->sk_type, 2164 s->sk_socket ? 2165 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2166 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2167 sock_i_ino(s)); 2168 2169 if (u->addr) { 2170 int i, len; 2171 seq_putc(seq, ' '); 2172 2173 i = 0; 2174 len = u->addr->len - sizeof(short); 2175 if (!UNIX_ABSTRACT(s)) 2176 len--; 2177 else { 2178 seq_putc(seq, '@'); 2179 i++; 2180 } 2181 for ( ; i < len; i++) 2182 seq_putc(seq, u->addr->name->sun_path[i]); 2183 } 2184 unix_state_unlock(s); 2185 seq_putc(seq, '\n'); 2186 } 2187 2188 return 0; 2189} 2190 2191static const struct seq_operations unix_seq_ops = { 2192 .start = unix_seq_start, 2193 .next = unix_seq_next, 2194 .stop = unix_seq_stop, 2195 .show = unix_seq_show, 2196}; 2197 2198static int unix_seq_open(struct inode *inode, struct file *file) 2199{ 2200 return seq_open_net(inode, file, &unix_seq_ops, 2201 sizeof(struct unix_iter_state)); 2202} 2203 2204static const struct file_operations unix_seq_fops = { 2205 .owner = THIS_MODULE, 2206 .open = unix_seq_open, 2207 .read = seq_read, 2208 .llseek = seq_lseek, 2209 .release = seq_release_net, 2210}; 2211 2212#endif 2213 2214static struct net_proto_family unix_family_ops = { 2215 .family = PF_UNIX, 2216 .create = unix_create, 2217 .owner = THIS_MODULE, 2218}; 2219 2220 2221static int unix_net_init(struct net *net) 2222{ 2223 int error = -ENOMEM; 2224 2225 net->unx.sysctl_max_dgram_qlen = 10; 2226 if (unix_sysctl_register(net)) 2227 goto out; 2228 2229#ifdef CONFIG_PROC_FS 2230 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2231 unix_sysctl_unregister(net); 2232 goto out; 2233 } 2234#endif 2235 error = 0; 2236out: 2237 return error; 2238} 2239 2240static void unix_net_exit(struct net *net) 2241{ 2242 unix_sysctl_unregister(net); 2243 proc_net_remove(net, "unix"); 2244} 2245 2246static struct pernet_operations unix_net_ops = { 2247 .init = unix_net_init, 2248 .exit = unix_net_exit, 2249}; 2250 2251static int __init af_unix_init(void) 2252{ 2253 int rc = -1; 2254 struct sk_buff *dummy_skb; 2255 2256 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2257 2258 rc = proto_register(&unix_proto, 1); 2259 if (rc != 0) { 2260 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2261 __func__); 2262 goto out; 2263 } 2264 2265 sock_register(&unix_family_ops); 2266 register_pernet_subsys(&unix_net_ops); 2267out: 2268 return rc; 2269} 2270 2271static void __exit af_unix_exit(void) 2272{ 2273 sock_unregister(PF_UNIX); 2274 proto_unregister(&unix_proto); 2275 unregister_pernet_subsys(&unix_net_ops); 2276} 2277 2278/* Earlier than device_initcall() so that other drivers invoking 2279 request_module() don't end up in a loop when modprobe tries 2280 to use a UNIX socket. But later than subsys_initcall() because 2281 we depend on stuff initialised there */ 2282fs_initcall(af_unix_init); 2283module_exit(af_unix_exit); 2284 2285MODULE_LICENSE("GPL"); 2286MODULE_ALIAS_NETPROTO(PF_UNIX); 2287