af_unix.c revision 5f23b734963ec7eaa3ebcd9050da0c9b7d143dd3
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 { 300 sock_hold(s); 301 goto found; 302 } 303 } 304 s = NULL; 305found: 306 spin_unlock(&unix_table_lock); 307 return s; 308} 309 310static inline int unix_writable(struct sock *sk) 311{ 312 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; 313} 314 315static void unix_write_space(struct sock *sk) 316{ 317 read_lock(&sk->sk_callback_lock); 318 if (unix_writable(sk)) { 319 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) 320 wake_up_interruptible_sync(sk->sk_sleep); 321 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 322 } 323 read_unlock(&sk->sk_callback_lock); 324} 325 326/* When dgram socket disconnects (or changes its peer), we clear its receive 327 * queue of packets arrived from previous peer. First, it allows to do 328 * flow control based only on wmem_alloc; second, sk connected to peer 329 * may receive messages only from that peer. */ 330static void unix_dgram_disconnected(struct sock *sk, struct sock *other) 331{ 332 if (!skb_queue_empty(&sk->sk_receive_queue)) { 333 skb_queue_purge(&sk->sk_receive_queue); 334 wake_up_interruptible_all(&unix_sk(sk)->peer_wait); 335 336 /* If one link of bidirectional dgram pipe is disconnected, 337 * we signal error. Messages are lost. Do not make this, 338 * when peer was not connected to us. 339 */ 340 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { 341 other->sk_err = ECONNRESET; 342 other->sk_error_report(other); 343 } 344 } 345} 346 347static void unix_sock_destructor(struct sock *sk) 348{ 349 struct unix_sock *u = unix_sk(sk); 350 351 skb_queue_purge(&sk->sk_receive_queue); 352 353 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 354 WARN_ON(!sk_unhashed(sk)); 355 WARN_ON(sk->sk_socket); 356 if (!sock_flag(sk, SOCK_DEAD)) { 357 printk("Attempt to release alive unix socket: %p\n", sk); 358 return; 359 } 360 361 if (u->addr) 362 unix_release_addr(u->addr); 363 364 atomic_dec(&unix_nr_socks); 365#ifdef UNIX_REFCNT_DEBUG 366 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, 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 wait_for_unix_gc(); 1347 err = scm_send(sock, msg, siocb->scm); 1348 if (err < 0) 1349 return err; 1350 1351 err = -EOPNOTSUPP; 1352 if (msg->msg_flags&MSG_OOB) 1353 goto out; 1354 1355 if (msg->msg_namelen) { 1356 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1357 if (err < 0) 1358 goto out; 1359 namelen = err; 1360 } else { 1361 sunaddr = NULL; 1362 err = -ENOTCONN; 1363 other = unix_peer_get(sk); 1364 if (!other) 1365 goto out; 1366 } 1367 1368 if (test_bit(SOCK_PASSCRED, &sock->flags) 1369 && !u->addr && (err = unix_autobind(sock)) != 0) 1370 goto out; 1371 1372 err = -EMSGSIZE; 1373 if (len > sk->sk_sndbuf - 32) 1374 goto out; 1375 1376 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1377 if (skb==NULL) 1378 goto out; 1379 1380 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1381 if (siocb->scm->fp) { 1382 err = unix_attach_fds(siocb->scm, skb); 1383 if (err) 1384 goto out_free; 1385 } 1386 unix_get_secdata(siocb->scm, skb); 1387 1388 skb_reset_transport_header(skb); 1389 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); 1390 if (err) 1391 goto out_free; 1392 1393 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1394 1395restart: 1396 if (!other) { 1397 err = -ECONNRESET; 1398 if (sunaddr == NULL) 1399 goto out_free; 1400 1401 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1402 hash, &err); 1403 if (other==NULL) 1404 goto out_free; 1405 } 1406 1407 unix_state_lock(other); 1408 err = -EPERM; 1409 if (!unix_may_send(sk, other)) 1410 goto out_unlock; 1411 1412 if (sock_flag(other, SOCK_DEAD)) { 1413 /* 1414 * Check with 1003.1g - what should 1415 * datagram error 1416 */ 1417 unix_state_unlock(other); 1418 sock_put(other); 1419 1420 err = 0; 1421 unix_state_lock(sk); 1422 if (unix_peer(sk) == other) { 1423 unix_peer(sk)=NULL; 1424 unix_state_unlock(sk); 1425 1426 unix_dgram_disconnected(sk, other); 1427 sock_put(other); 1428 err = -ECONNREFUSED; 1429 } else { 1430 unix_state_unlock(sk); 1431 } 1432 1433 other = NULL; 1434 if (err) 1435 goto out_free; 1436 goto restart; 1437 } 1438 1439 err = -EPIPE; 1440 if (other->sk_shutdown & RCV_SHUTDOWN) 1441 goto out_unlock; 1442 1443 if (sk->sk_type != SOCK_SEQPACKET) { 1444 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1445 if (err) 1446 goto out_unlock; 1447 } 1448 1449 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1450 if (!timeo) { 1451 err = -EAGAIN; 1452 goto out_unlock; 1453 } 1454 1455 timeo = unix_wait_for_peer(other, timeo); 1456 1457 err = sock_intr_errno(timeo); 1458 if (signal_pending(current)) 1459 goto out_free; 1460 1461 goto restart; 1462 } 1463 1464 skb_queue_tail(&other->sk_receive_queue, skb); 1465 unix_state_unlock(other); 1466 other->sk_data_ready(other, len); 1467 sock_put(other); 1468 scm_destroy(siocb->scm); 1469 return len; 1470 1471out_unlock: 1472 unix_state_unlock(other); 1473out_free: 1474 kfree_skb(skb); 1475out: 1476 if (other) 1477 sock_put(other); 1478 scm_destroy(siocb->scm); 1479 return err; 1480} 1481 1482 1483static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1484 struct msghdr *msg, size_t len) 1485{ 1486 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1487 struct sock *sk = sock->sk; 1488 struct sock *other = NULL; 1489 struct sockaddr_un *sunaddr=msg->msg_name; 1490 int err,size; 1491 struct sk_buff *skb; 1492 int sent=0; 1493 struct scm_cookie tmp_scm; 1494 1495 if (NULL == siocb->scm) 1496 siocb->scm = &tmp_scm; 1497 wait_for_unix_gc(); 1498 err = scm_send(sock, msg, siocb->scm); 1499 if (err < 0) 1500 return err; 1501 1502 err = -EOPNOTSUPP; 1503 if (msg->msg_flags&MSG_OOB) 1504 goto out_err; 1505 1506 if (msg->msg_namelen) { 1507 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1508 goto out_err; 1509 } else { 1510 sunaddr = NULL; 1511 err = -ENOTCONN; 1512 other = unix_peer(sk); 1513 if (!other) 1514 goto out_err; 1515 } 1516 1517 if (sk->sk_shutdown & SEND_SHUTDOWN) 1518 goto pipe_err; 1519 1520 while(sent < len) 1521 { 1522 /* 1523 * Optimisation for the fact that under 0.01% of X 1524 * messages typically need breaking up. 1525 */ 1526 1527 size = len-sent; 1528 1529 /* Keep two messages in the pipe so it schedules better */ 1530 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1531 size = (sk->sk_sndbuf >> 1) - 64; 1532 1533 if (size > SKB_MAX_ALLOC) 1534 size = SKB_MAX_ALLOC; 1535 1536 /* 1537 * Grab a buffer 1538 */ 1539 1540 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); 1541 1542 if (skb==NULL) 1543 goto out_err; 1544 1545 /* 1546 * If you pass two values to the sock_alloc_send_skb 1547 * it tries to grab the large buffer with GFP_NOFS 1548 * (which can fail easily), and if it fails grab the 1549 * fallback size buffer which is under a page and will 1550 * succeed. [Alan] 1551 */ 1552 size = min_t(int, size, skb_tailroom(skb)); 1553 1554 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1555 if (siocb->scm->fp) { 1556 err = unix_attach_fds(siocb->scm, skb); 1557 if (err) { 1558 kfree_skb(skb); 1559 goto out_err; 1560 } 1561 } 1562 1563 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { 1564 kfree_skb(skb); 1565 goto out_err; 1566 } 1567 1568 unix_state_lock(other); 1569 1570 if (sock_flag(other, SOCK_DEAD) || 1571 (other->sk_shutdown & RCV_SHUTDOWN)) 1572 goto pipe_err_free; 1573 1574 skb_queue_tail(&other->sk_receive_queue, skb); 1575 unix_state_unlock(other); 1576 other->sk_data_ready(other, size); 1577 sent+=size; 1578 } 1579 1580 scm_destroy(siocb->scm); 1581 siocb->scm = NULL; 1582 1583 return sent; 1584 1585pipe_err_free: 1586 unix_state_unlock(other); 1587 kfree_skb(skb); 1588pipe_err: 1589 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1590 send_sig(SIGPIPE,current,0); 1591 err = -EPIPE; 1592out_err: 1593 scm_destroy(siocb->scm); 1594 siocb->scm = NULL; 1595 return sent ? : err; 1596} 1597 1598static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1599 struct msghdr *msg, size_t len) 1600{ 1601 int err; 1602 struct sock *sk = sock->sk; 1603 1604 err = sock_error(sk); 1605 if (err) 1606 return err; 1607 1608 if (sk->sk_state != TCP_ESTABLISHED) 1609 return -ENOTCONN; 1610 1611 if (msg->msg_namelen) 1612 msg->msg_namelen = 0; 1613 1614 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1615} 1616 1617static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1618{ 1619 struct unix_sock *u = unix_sk(sk); 1620 1621 msg->msg_namelen = 0; 1622 if (u->addr) { 1623 msg->msg_namelen = u->addr->len; 1624 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1625 } 1626} 1627 1628static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1629 struct msghdr *msg, size_t size, 1630 int flags) 1631{ 1632 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1633 struct scm_cookie tmp_scm; 1634 struct sock *sk = sock->sk; 1635 struct unix_sock *u = unix_sk(sk); 1636 int noblock = flags & MSG_DONTWAIT; 1637 struct sk_buff *skb; 1638 int err; 1639 1640 err = -EOPNOTSUPP; 1641 if (flags&MSG_OOB) 1642 goto out; 1643 1644 msg->msg_namelen = 0; 1645 1646 mutex_lock(&u->readlock); 1647 1648 skb = skb_recv_datagram(sk, flags, noblock, &err); 1649 if (!skb) { 1650 unix_state_lock(sk); 1651 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1652 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1653 (sk->sk_shutdown & RCV_SHUTDOWN)) 1654 err = 0; 1655 unix_state_unlock(sk); 1656 goto out_unlock; 1657 } 1658 1659 wake_up_interruptible_sync(&u->peer_wait); 1660 1661 if (msg->msg_name) 1662 unix_copy_addr(msg, skb->sk); 1663 1664 if (size > skb->len) 1665 size = skb->len; 1666 else if (size < skb->len) 1667 msg->msg_flags |= MSG_TRUNC; 1668 1669 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1670 if (err) 1671 goto out_free; 1672 1673 if (!siocb->scm) { 1674 siocb->scm = &tmp_scm; 1675 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1676 } 1677 siocb->scm->creds = *UNIXCREDS(skb); 1678 unix_set_secdata(siocb->scm, skb); 1679 1680 if (!(flags & MSG_PEEK)) 1681 { 1682 if (UNIXCB(skb).fp) 1683 unix_detach_fds(siocb->scm, skb); 1684 } 1685 else 1686 { 1687 /* It is questionable: on PEEK we could: 1688 - do not return fds - good, but too simple 8) 1689 - return fds, and do not return them on read (old strategy, 1690 apparently wrong) 1691 - clone fds (I chose it for now, it is the most universal 1692 solution) 1693 1694 POSIX 1003.1g does not actually define this clearly 1695 at all. POSIX 1003.1g doesn't define a lot of things 1696 clearly however! 1697 1698 */ 1699 if (UNIXCB(skb).fp) 1700 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1701 } 1702 err = size; 1703 1704 scm_recv(sock, msg, siocb->scm, flags); 1705 1706out_free: 1707 skb_free_datagram(sk,skb); 1708out_unlock: 1709 mutex_unlock(&u->readlock); 1710out: 1711 return err; 1712} 1713 1714/* 1715 * Sleep until data has arrive. But check for races.. 1716 */ 1717 1718static long unix_stream_data_wait(struct sock * sk, long timeo) 1719{ 1720 DEFINE_WAIT(wait); 1721 1722 unix_state_lock(sk); 1723 1724 for (;;) { 1725 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1726 1727 if (!skb_queue_empty(&sk->sk_receive_queue) || 1728 sk->sk_err || 1729 (sk->sk_shutdown & RCV_SHUTDOWN) || 1730 signal_pending(current) || 1731 !timeo) 1732 break; 1733 1734 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1735 unix_state_unlock(sk); 1736 timeo = schedule_timeout(timeo); 1737 unix_state_lock(sk); 1738 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1739 } 1740 1741 finish_wait(sk->sk_sleep, &wait); 1742 unix_state_unlock(sk); 1743 return timeo; 1744} 1745 1746 1747 1748static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1749 struct msghdr *msg, size_t size, 1750 int flags) 1751{ 1752 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1753 struct scm_cookie tmp_scm; 1754 struct sock *sk = sock->sk; 1755 struct unix_sock *u = unix_sk(sk); 1756 struct sockaddr_un *sunaddr=msg->msg_name; 1757 int copied = 0; 1758 int check_creds = 0; 1759 int target; 1760 int err = 0; 1761 long timeo; 1762 1763 err = -EINVAL; 1764 if (sk->sk_state != TCP_ESTABLISHED) 1765 goto out; 1766 1767 err = -EOPNOTSUPP; 1768 if (flags&MSG_OOB) 1769 goto out; 1770 1771 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1772 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1773 1774 msg->msg_namelen = 0; 1775 1776 /* Lock the socket to prevent queue disordering 1777 * while sleeps in memcpy_tomsg 1778 */ 1779 1780 if (!siocb->scm) { 1781 siocb->scm = &tmp_scm; 1782 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1783 } 1784 1785 mutex_lock(&u->readlock); 1786 1787 do 1788 { 1789 int chunk; 1790 struct sk_buff *skb; 1791 1792 unix_state_lock(sk); 1793 skb = skb_dequeue(&sk->sk_receive_queue); 1794 if (skb==NULL) 1795 { 1796 if (copied >= target) 1797 goto unlock; 1798 1799 /* 1800 * POSIX 1003.1g mandates this order. 1801 */ 1802 1803 if ((err = sock_error(sk)) != 0) 1804 goto unlock; 1805 if (sk->sk_shutdown & RCV_SHUTDOWN) 1806 goto unlock; 1807 1808 unix_state_unlock(sk); 1809 err = -EAGAIN; 1810 if (!timeo) 1811 break; 1812 mutex_unlock(&u->readlock); 1813 1814 timeo = unix_stream_data_wait(sk, timeo); 1815 1816 if (signal_pending(current)) { 1817 err = sock_intr_errno(timeo); 1818 goto out; 1819 } 1820 mutex_lock(&u->readlock); 1821 continue; 1822 unlock: 1823 unix_state_unlock(sk); 1824 break; 1825 } 1826 unix_state_unlock(sk); 1827 1828 if (check_creds) { 1829 /* Never glue messages from different writers */ 1830 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { 1831 skb_queue_head(&sk->sk_receive_queue, skb); 1832 break; 1833 } 1834 } else { 1835 /* Copy credentials */ 1836 siocb->scm->creds = *UNIXCREDS(skb); 1837 check_creds = 1; 1838 } 1839 1840 /* Copy address just once */ 1841 if (sunaddr) 1842 { 1843 unix_copy_addr(msg, skb->sk); 1844 sunaddr = NULL; 1845 } 1846 1847 chunk = min_t(unsigned int, skb->len, size); 1848 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1849 skb_queue_head(&sk->sk_receive_queue, skb); 1850 if (copied == 0) 1851 copied = -EFAULT; 1852 break; 1853 } 1854 copied += chunk; 1855 size -= chunk; 1856 1857 /* Mark read part of skb as used */ 1858 if (!(flags & MSG_PEEK)) 1859 { 1860 skb_pull(skb, chunk); 1861 1862 if (UNIXCB(skb).fp) 1863 unix_detach_fds(siocb->scm, skb); 1864 1865 /* put the skb back if we didn't use it up.. */ 1866 if (skb->len) 1867 { 1868 skb_queue_head(&sk->sk_receive_queue, skb); 1869 break; 1870 } 1871 1872 kfree_skb(skb); 1873 1874 if (siocb->scm->fp) 1875 break; 1876 } 1877 else 1878 { 1879 /* It is questionable, see note in unix_dgram_recvmsg. 1880 */ 1881 if (UNIXCB(skb).fp) 1882 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1883 1884 /* put message back and return */ 1885 skb_queue_head(&sk->sk_receive_queue, skb); 1886 break; 1887 } 1888 } while (size); 1889 1890 mutex_unlock(&u->readlock); 1891 scm_recv(sock, msg, siocb->scm, flags); 1892out: 1893 return copied ? : err; 1894} 1895 1896static int unix_shutdown(struct socket *sock, int mode) 1897{ 1898 struct sock *sk = sock->sk; 1899 struct sock *other; 1900 1901 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1902 1903 if (mode) { 1904 unix_state_lock(sk); 1905 sk->sk_shutdown |= mode; 1906 other=unix_peer(sk); 1907 if (other) 1908 sock_hold(other); 1909 unix_state_unlock(sk); 1910 sk->sk_state_change(sk); 1911 1912 if (other && 1913 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1914 1915 int peer_mode = 0; 1916 1917 if (mode&RCV_SHUTDOWN) 1918 peer_mode |= SEND_SHUTDOWN; 1919 if (mode&SEND_SHUTDOWN) 1920 peer_mode |= RCV_SHUTDOWN; 1921 unix_state_lock(other); 1922 other->sk_shutdown |= peer_mode; 1923 unix_state_unlock(other); 1924 other->sk_state_change(other); 1925 read_lock(&other->sk_callback_lock); 1926 if (peer_mode == SHUTDOWN_MASK) 1927 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1928 else if (peer_mode & RCV_SHUTDOWN) 1929 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1930 read_unlock(&other->sk_callback_lock); 1931 } 1932 if (other) 1933 sock_put(other); 1934 } 1935 return 0; 1936} 1937 1938static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1939{ 1940 struct sock *sk = sock->sk; 1941 long amount=0; 1942 int err; 1943 1944 switch(cmd) 1945 { 1946 case SIOCOUTQ: 1947 amount = atomic_read(&sk->sk_wmem_alloc); 1948 err = put_user(amount, (int __user *)arg); 1949 break; 1950 case SIOCINQ: 1951 { 1952 struct sk_buff *skb; 1953 1954 if (sk->sk_state == TCP_LISTEN) { 1955 err = -EINVAL; 1956 break; 1957 } 1958 1959 spin_lock(&sk->sk_receive_queue.lock); 1960 if (sk->sk_type == SOCK_STREAM || 1961 sk->sk_type == SOCK_SEQPACKET) { 1962 skb_queue_walk(&sk->sk_receive_queue, skb) 1963 amount += skb->len; 1964 } else { 1965 skb = skb_peek(&sk->sk_receive_queue); 1966 if (skb) 1967 amount=skb->len; 1968 } 1969 spin_unlock(&sk->sk_receive_queue.lock); 1970 err = put_user(amount, (int __user *)arg); 1971 break; 1972 } 1973 1974 default: 1975 err = -ENOIOCTLCMD; 1976 break; 1977 } 1978 return err; 1979} 1980 1981static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) 1982{ 1983 struct sock *sk = sock->sk; 1984 unsigned int mask; 1985 1986 poll_wait(file, sk->sk_sleep, wait); 1987 mask = 0; 1988 1989 /* exceptional events? */ 1990 if (sk->sk_err) 1991 mask |= POLLERR; 1992 if (sk->sk_shutdown == SHUTDOWN_MASK) 1993 mask |= POLLHUP; 1994 if (sk->sk_shutdown & RCV_SHUTDOWN) 1995 mask |= POLLRDHUP; 1996 1997 /* readable? */ 1998 if (!skb_queue_empty(&sk->sk_receive_queue) || 1999 (sk->sk_shutdown & RCV_SHUTDOWN)) 2000 mask |= POLLIN | POLLRDNORM; 2001 2002 /* Connection-based need to check for termination and startup */ 2003 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) 2004 mask |= POLLHUP; 2005 2006 /* 2007 * we set writable also when the other side has shut down the 2008 * connection. This prevents stuck sockets. 2009 */ 2010 if (unix_writable(sk)) 2011 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2012 2013 return mask; 2014} 2015 2016static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 2017 poll_table *wait) 2018{ 2019 struct sock *sk = sock->sk, *other; 2020 unsigned int mask, writable; 2021 2022 poll_wait(file, sk->sk_sleep, wait); 2023 mask = 0; 2024 2025 /* exceptional events? */ 2026 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2027 mask |= POLLERR; 2028 if (sk->sk_shutdown & RCV_SHUTDOWN) 2029 mask |= POLLRDHUP; 2030 if (sk->sk_shutdown == SHUTDOWN_MASK) 2031 mask |= POLLHUP; 2032 2033 /* readable? */ 2034 if (!skb_queue_empty(&sk->sk_receive_queue) || 2035 (sk->sk_shutdown & RCV_SHUTDOWN)) 2036 mask |= POLLIN | POLLRDNORM; 2037 2038 /* Connection-based need to check for termination and startup */ 2039 if (sk->sk_type == SOCK_SEQPACKET) { 2040 if (sk->sk_state == TCP_CLOSE) 2041 mask |= POLLHUP; 2042 /* connection hasn't started yet? */ 2043 if (sk->sk_state == TCP_SYN_SENT) 2044 return mask; 2045 } 2046 2047 /* writable? */ 2048 writable = unix_writable(sk); 2049 if (writable) { 2050 other = unix_peer_get(sk); 2051 if (other) { 2052 if (unix_peer(other) != sk) { 2053 poll_wait(file, &unix_sk(other)->peer_wait, 2054 wait); 2055 if (unix_recvq_full(other)) 2056 writable = 0; 2057 } 2058 2059 sock_put(other); 2060 } 2061 } 2062 2063 if (writable) 2064 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2065 else 2066 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2067 2068 return mask; 2069} 2070 2071#ifdef CONFIG_PROC_FS 2072static struct sock *first_unix_socket(int *i) 2073{ 2074 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2075 if (!hlist_empty(&unix_socket_table[*i])) 2076 return __sk_head(&unix_socket_table[*i]); 2077 } 2078 return NULL; 2079} 2080 2081static struct sock *next_unix_socket(int *i, struct sock *s) 2082{ 2083 struct sock *next = sk_next(s); 2084 /* More in this chain? */ 2085 if (next) 2086 return next; 2087 /* Look for next non-empty chain. */ 2088 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2089 if (!hlist_empty(&unix_socket_table[*i])) 2090 return __sk_head(&unix_socket_table[*i]); 2091 } 2092 return NULL; 2093} 2094 2095struct unix_iter_state { 2096 struct seq_net_private p; 2097 int i; 2098}; 2099static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2100{ 2101 struct unix_iter_state *iter = seq->private; 2102 loff_t off = 0; 2103 struct sock *s; 2104 2105 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2106 if (sock_net(s) != seq_file_net(seq)) 2107 continue; 2108 if (off == pos) 2109 return s; 2110 ++off; 2111 } 2112 return NULL; 2113} 2114 2115 2116static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2117 __acquires(unix_table_lock) 2118{ 2119 spin_lock(&unix_table_lock); 2120 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2121} 2122 2123static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2124{ 2125 struct unix_iter_state *iter = seq->private; 2126 struct sock *sk = v; 2127 ++*pos; 2128 2129 if (v == SEQ_START_TOKEN) 2130 sk = first_unix_socket(&iter->i); 2131 else 2132 sk = next_unix_socket(&iter->i, sk); 2133 while (sk && (sock_net(sk) != seq_file_net(seq))) 2134 sk = next_unix_socket(&iter->i, sk); 2135 return sk; 2136} 2137 2138static void unix_seq_stop(struct seq_file *seq, void *v) 2139 __releases(unix_table_lock) 2140{ 2141 spin_unlock(&unix_table_lock); 2142} 2143 2144static int unix_seq_show(struct seq_file *seq, void *v) 2145{ 2146 2147 if (v == SEQ_START_TOKEN) 2148 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2149 "Inode Path\n"); 2150 else { 2151 struct sock *s = v; 2152 struct unix_sock *u = unix_sk(s); 2153 unix_state_lock(s); 2154 2155 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2156 s, 2157 atomic_read(&s->sk_refcnt), 2158 0, 2159 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2160 s->sk_type, 2161 s->sk_socket ? 2162 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2163 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2164 sock_i_ino(s)); 2165 2166 if (u->addr) { 2167 int i, len; 2168 seq_putc(seq, ' '); 2169 2170 i = 0; 2171 len = u->addr->len - sizeof(short); 2172 if (!UNIX_ABSTRACT(s)) 2173 len--; 2174 else { 2175 seq_putc(seq, '@'); 2176 i++; 2177 } 2178 for ( ; i < len; i++) 2179 seq_putc(seq, u->addr->name->sun_path[i]); 2180 } 2181 unix_state_unlock(s); 2182 seq_putc(seq, '\n'); 2183 } 2184 2185 return 0; 2186} 2187 2188static const struct seq_operations unix_seq_ops = { 2189 .start = unix_seq_start, 2190 .next = unix_seq_next, 2191 .stop = unix_seq_stop, 2192 .show = unix_seq_show, 2193}; 2194 2195 2196static int unix_seq_open(struct inode *inode, struct file *file) 2197{ 2198 return seq_open_net(inode, file, &unix_seq_ops, 2199 sizeof(struct unix_iter_state)); 2200} 2201 2202static const struct file_operations unix_seq_fops = { 2203 .owner = THIS_MODULE, 2204 .open = unix_seq_open, 2205 .read = seq_read, 2206 .llseek = seq_lseek, 2207 .release = seq_release_net, 2208}; 2209 2210#endif 2211 2212static struct net_proto_family unix_family_ops = { 2213 .family = PF_UNIX, 2214 .create = unix_create, 2215 .owner = THIS_MODULE, 2216}; 2217 2218 2219static int unix_net_init(struct net *net) 2220{ 2221 int error = -ENOMEM; 2222 2223 net->unx.sysctl_max_dgram_qlen = 10; 2224 if (unix_sysctl_register(net)) 2225 goto out; 2226 2227#ifdef CONFIG_PROC_FS 2228 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2229 unix_sysctl_unregister(net); 2230 goto out; 2231 } 2232#endif 2233 error = 0; 2234out: 2235 return error; 2236} 2237 2238static void unix_net_exit(struct net *net) 2239{ 2240 unix_sysctl_unregister(net); 2241 proc_net_remove(net, "unix"); 2242} 2243 2244static struct pernet_operations unix_net_ops = { 2245 .init = unix_net_init, 2246 .exit = unix_net_exit, 2247}; 2248 2249static int __init af_unix_init(void) 2250{ 2251 int rc = -1; 2252 struct sk_buff *dummy_skb; 2253 2254 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2255 2256 rc = proto_register(&unix_proto, 1); 2257 if (rc != 0) { 2258 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2259 __func__); 2260 goto out; 2261 } 2262 2263 sock_register(&unix_family_ops); 2264 register_pernet_subsys(&unix_net_ops); 2265out: 2266 return rc; 2267} 2268 2269static void __exit af_unix_exit(void) 2270{ 2271 sock_unregister(PF_UNIX); 2272 proto_unregister(&unix_proto); 2273 unregister_pernet_subsys(&unix_net_ops); 2274} 2275 2276/* Earlier than device_initcall() so that other drivers invoking 2277 request_module() don't end up in a loop when modprobe tries 2278 to use a UNIX socket. But later than subsys_initcall() because 2279 we depend on stuff initialised there */ 2280fs_initcall(af_unix_init); 2281module_exit(af_unix_exit); 2282 2283MODULE_LICENSE("GPL"); 2284MODULE_ALIAS_NETPROTO(PF_UNIX); 2285