af_unix.c revision 3c73419c09a5ef73d56472dbfdade9e311496e9b
1/* 2 * NET4: Implementation of BSD Unix domain sockets. 3 * 4 * Authors: Alan Cox, <alan.cox@linux.org> 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 * Version: $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $ 12 * 13 * Fixes: 14 * Linus Torvalds : Assorted bug cures. 15 * Niibe Yutaka : async I/O support. 16 * Carsten Paeth : PF_UNIX check, address fixes. 17 * Alan Cox : Limit size of allocated blocks. 18 * Alan Cox : Fixed the stupid socketpair bug. 19 * Alan Cox : BSD compatibility fine tuning. 20 * Alan Cox : Fixed a bug in connect when interrupted. 21 * Alan Cox : Sorted out a proper draft version of 22 * file descriptor passing hacked up from 23 * Mike Shaver's work. 24 * Marty Leisner : Fixes to fd passing 25 * Nick Nevin : recvmsg bugfix. 26 * Alan Cox : Started proper garbage collector 27 * Heiko EiBfeldt : Missing verify_area check 28 * Alan Cox : Started POSIXisms 29 * Andreas Schwab : Replace inode by dentry for proper 30 * reference counting 31 * Kirk Petersen : Made this a module 32 * Christoph Rohland : Elegant non-blocking accept/connect algorithm. 33 * Lots of bug fixes. 34 * Alexey Kuznetosv : Repaired (I hope) bugs introduces 35 * by above two patches. 36 * Andrea Arcangeli : If possible we block in connect(2) 37 * if the max backlog of the listen socket 38 * is been reached. This won't break 39 * old apps and it will avoid huge amount 40 * of socks hashed (this for unix_gc() 41 * performances reasons). 42 * Security fix that limits the max 43 * number of socks to 2*max_files and 44 * the number of skb queueable in the 45 * dgram receiver. 46 * Artur Skawina : Hash function optimizations 47 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) 48 * Malcolm Beattie : Set peercred for socketpair 49 * Michal Ostrowski : Module initialization cleanup. 50 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, 51 * the core infrastructure is doing that 52 * for all net proto families now (2.5.69+) 53 * 54 * 55 * Known differences from reference BSD that was tested: 56 * 57 * [TO FIX] 58 * ECONNREFUSED is not returned from one end of a connected() socket to the 59 * other the moment one end closes. 60 * fstat() doesn't return st_dev=0, and give the blksize as high water mark 61 * and a fake inode identifier (nor the BSD first socket fstat twice bug). 62 * [NOT TO FIX] 63 * accept() returns a path name even if the connecting socket has closed 64 * in the meantime (BSD loses the path and gives up). 65 * accept() returns 0 length path for an unbound connector. BSD returns 16 66 * and a null first byte in the path (but not for gethost/peername - BSD bug ??) 67 * socketpair(...SOCK_RAW..) doesn't panic the kernel. 68 * BSD af_unix apparently has connect forgetting to block properly. 69 * (need to check this with the POSIX spec in detail) 70 * 71 * Differences from 2.0.0-11-... (ANK) 72 * Bug fixes and improvements. 73 * - client shutdown killed server socket. 74 * - removed all useless cli/sti pairs. 75 * 76 * Semantic changes/extensions. 77 * - generic control message passing. 78 * - SCM_CREDENTIALS control message. 79 * - "Abstract" (not FS based) socket bindings. 80 * Abstract names are sequences of bytes (not zero terminated) 81 * started by 0, so that this name space does not intersect 82 * with BSD names. 83 */ 84 85#include <linux/module.h> 86#include <linux/kernel.h> 87#include <linux/signal.h> 88#include <linux/sched.h> 89#include <linux/errno.h> 90#include <linux/string.h> 91#include <linux/stat.h> 92#include <linux/dcache.h> 93#include <linux/namei.h> 94#include <linux/socket.h> 95#include <linux/un.h> 96#include <linux/fcntl.h> 97#include <linux/termios.h> 98#include <linux/sockios.h> 99#include <linux/net.h> 100#include <linux/in.h> 101#include <linux/fs.h> 102#include <linux/slab.h> 103#include <asm/uaccess.h> 104#include <linux/skbuff.h> 105#include <linux/netdevice.h> 106#include <net/net_namespace.h> 107#include <net/sock.h> 108#include <net/tcp_states.h> 109#include <net/af_unix.h> 110#include <linux/proc_fs.h> 111#include <linux/seq_file.h> 112#include <net/scm.h> 113#include <linux/init.h> 114#include <linux/poll.h> 115#include <linux/rtnetlink.h> 116#include <linux/mount.h> 117#include <net/checksum.h> 118#include <linux/security.h> 119 120static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; 121static DEFINE_SPINLOCK(unix_table_lock); 122static atomic_t unix_nr_socks = ATOMIC_INIT(0); 123 124#define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) 125 126#define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE) 127 128#ifdef CONFIG_SECURITY_NETWORK 129static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 130{ 131 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); 132} 133 134static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) 135{ 136 scm->secid = *UNIXSID(skb); 137} 138#else 139static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 140{ } 141 142static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) 143{ } 144#endif /* CONFIG_SECURITY_NETWORK */ 145 146/* 147 * SMP locking strategy: 148 * hash table is protected with spinlock unix_table_lock 149 * each socket state is protected by separate rwlock. 150 */ 151 152static inline unsigned unix_hash_fold(__wsum n) 153{ 154 unsigned hash = (__force unsigned)n; 155 hash ^= hash>>16; 156 hash ^= hash>>8; 157 return hash&(UNIX_HASH_SIZE-1); 158} 159 160#define unix_peer(sk) (unix_sk(sk)->peer) 161 162static inline int unix_our_peer(struct sock *sk, struct sock *osk) 163{ 164 return unix_peer(osk) == sk; 165} 166 167static inline int unix_may_send(struct sock *sk, struct sock *osk) 168{ 169 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk)); 170} 171 172static inline int unix_recvq_full(struct sock const *sk) 173{ 174 return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; 175} 176 177static struct sock *unix_peer_get(struct sock *s) 178{ 179 struct sock *peer; 180 181 unix_state_lock(s); 182 peer = unix_peer(s); 183 if (peer) 184 sock_hold(peer); 185 unix_state_unlock(s); 186 return peer; 187} 188 189static inline void unix_release_addr(struct unix_address *addr) 190{ 191 if (atomic_dec_and_test(&addr->refcnt)) 192 kfree(addr); 193} 194 195/* 196 * Check unix socket name: 197 * - should be not zero length. 198 * - if started by not zero, should be NULL terminated (FS object) 199 * - if started by zero, it is abstract name. 200 */ 201 202static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp) 203{ 204 if (len <= sizeof(short) || len > sizeof(*sunaddr)) 205 return -EINVAL; 206 if (!sunaddr || sunaddr->sun_family != AF_UNIX) 207 return -EINVAL; 208 if (sunaddr->sun_path[0]) { 209 /* 210 * This may look like an off by one error but it is a bit more 211 * subtle. 108 is the longest valid AF_UNIX path for a binding. 212 * sun_path[108] doesnt as such exist. However in kernel space 213 * we are guaranteed that it is a valid memory location in our 214 * kernel address buffer. 215 */ 216 ((char *)sunaddr)[len]=0; 217 len = strlen(sunaddr->sun_path)+1+sizeof(short); 218 return len; 219 } 220 221 *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0)); 222 return len; 223} 224 225static void __unix_remove_socket(struct sock *sk) 226{ 227 sk_del_node_init(sk); 228} 229 230static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) 231{ 232 BUG_TRAP(sk_unhashed(sk)); 233 sk_add_node(sk, list); 234} 235 236static inline void unix_remove_socket(struct sock *sk) 237{ 238 spin_lock(&unix_table_lock); 239 __unix_remove_socket(sk); 240 spin_unlock(&unix_table_lock); 241} 242 243static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) 244{ 245 spin_lock(&unix_table_lock); 246 __unix_insert_socket(list, sk); 247 spin_unlock(&unix_table_lock); 248} 249 250static struct sock *__unix_find_socket_byname(struct net *net, 251 struct sockaddr_un *sunname, 252 int len, int type, unsigned hash) 253{ 254 struct sock *s; 255 struct hlist_node *node; 256 257 sk_for_each(s, node, &unix_socket_table[hash ^ type]) { 258 struct unix_sock *u = unix_sk(s); 259 260 if (!net_eq(sock_net(s), net)) 261 continue; 262 263 if (u->addr->len == len && 264 !memcmp(u->addr->name, sunname, len)) 265 goto found; 266 } 267 s = NULL; 268found: 269 return s; 270} 271 272static inline struct sock *unix_find_socket_byname(struct net *net, 273 struct sockaddr_un *sunname, 274 int len, int type, 275 unsigned hash) 276{ 277 struct sock *s; 278 279 spin_lock(&unix_table_lock); 280 s = __unix_find_socket_byname(net, sunname, len, type, hash); 281 if (s) 282 sock_hold(s); 283 spin_unlock(&unix_table_lock); 284 return s; 285} 286 287static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i) 288{ 289 struct sock *s; 290 struct hlist_node *node; 291 292 spin_lock(&unix_table_lock); 293 sk_for_each(s, node, 294 &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { 295 struct dentry *dentry = unix_sk(s)->dentry; 296 297 if (!net_eq(sock_net(s), net)) 298 continue; 299 300 if(dentry && dentry->d_inode == i) 301 { 302 sock_hold(s); 303 goto found; 304 } 305 } 306 s = NULL; 307found: 308 spin_unlock(&unix_table_lock); 309 return s; 310} 311 312static inline int unix_writable(struct sock *sk) 313{ 314 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; 315} 316 317static void unix_write_space(struct sock *sk) 318{ 319 read_lock(&sk->sk_callback_lock); 320 if (unix_writable(sk)) { 321 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) 322 wake_up_interruptible_sync(sk->sk_sleep); 323 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 324 } 325 read_unlock(&sk->sk_callback_lock); 326} 327 328/* When dgram socket disconnects (or changes its peer), we clear its receive 329 * queue of packets arrived from previous peer. First, it allows to do 330 * flow control based only on wmem_alloc; second, sk connected to peer 331 * may receive messages only from that peer. */ 332static void unix_dgram_disconnected(struct sock *sk, struct sock *other) 333{ 334 if (!skb_queue_empty(&sk->sk_receive_queue)) { 335 skb_queue_purge(&sk->sk_receive_queue); 336 wake_up_interruptible_all(&unix_sk(sk)->peer_wait); 337 338 /* If one link of bidirectional dgram pipe is disconnected, 339 * we signal error. Messages are lost. Do not make this, 340 * when peer was not connected to us. 341 */ 342 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { 343 other->sk_err = ECONNRESET; 344 other->sk_error_report(other); 345 } 346 } 347} 348 349static void unix_sock_destructor(struct sock *sk) 350{ 351 struct unix_sock *u = unix_sk(sk); 352 353 skb_queue_purge(&sk->sk_receive_queue); 354 355 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); 356 BUG_TRAP(sk_unhashed(sk)); 357 BUG_TRAP(!sk->sk_socket); 358 if (!sock_flag(sk, SOCK_DEAD)) { 359 printk("Attempt to release alive unix socket: %p\n", sk); 360 return; 361 } 362 363 if (u->addr) 364 unix_release_addr(u->addr); 365 366 atomic_dec(&unix_nr_socks); 367#ifdef UNIX_REFCNT_DEBUG 368 printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks)); 369#endif 370} 371 372static int unix_release_sock (struct sock *sk, int embrion) 373{ 374 struct unix_sock *u = unix_sk(sk); 375 struct dentry *dentry; 376 struct vfsmount *mnt; 377 struct sock *skpair; 378 struct sk_buff *skb; 379 int state; 380 381 unix_remove_socket(sk); 382 383 /* Clear state */ 384 unix_state_lock(sk); 385 sock_orphan(sk); 386 sk->sk_shutdown = SHUTDOWN_MASK; 387 dentry = u->dentry; 388 u->dentry = NULL; 389 mnt = u->mnt; 390 u->mnt = NULL; 391 state = sk->sk_state; 392 sk->sk_state = TCP_CLOSE; 393 unix_state_unlock(sk); 394 395 wake_up_interruptible_all(&u->peer_wait); 396 397 skpair=unix_peer(sk); 398 399 if (skpair!=NULL) { 400 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { 401 unix_state_lock(skpair); 402 /* No more writes */ 403 skpair->sk_shutdown = SHUTDOWN_MASK; 404 if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) 405 skpair->sk_err = ECONNRESET; 406 unix_state_unlock(skpair); 407 skpair->sk_state_change(skpair); 408 read_lock(&skpair->sk_callback_lock); 409 sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); 410 read_unlock(&skpair->sk_callback_lock); 411 } 412 sock_put(skpair); /* It may now die */ 413 unix_peer(sk) = NULL; 414 } 415 416 /* Try to flush out this socket. Throw out buffers at least */ 417 418 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { 419 if (state==TCP_LISTEN) 420 unix_release_sock(skb->sk, 1); 421 /* passed fds are erased in the kfree_skb hook */ 422 kfree_skb(skb); 423 } 424 425 if (dentry) { 426 dput(dentry); 427 mntput(mnt); 428 } 429 430 sock_put(sk); 431 432 /* ---- Socket is dead now and most probably destroyed ---- */ 433 434 /* 435 * Fixme: BSD difference: In BSD all sockets connected to use get 436 * ECONNRESET and we die on the spot. In Linux we behave 437 * like files and pipes do and wait for the last 438 * dereference. 439 * 440 * Can't we simply set sock->err? 441 * 442 * What the above comment does talk about? --ANK(980817) 443 */ 444 445 if (unix_tot_inflight) 446 unix_gc(); /* Garbage collect fds */ 447 448 return 0; 449} 450 451static int unix_listen(struct socket *sock, int backlog) 452{ 453 int err; 454 struct sock *sk = sock->sk; 455 struct unix_sock *u = unix_sk(sk); 456 457 err = -EOPNOTSUPP; 458 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) 459 goto out; /* Only stream/seqpacket sockets accept */ 460 err = -EINVAL; 461 if (!u->addr) 462 goto out; /* No listens on an unbound socket */ 463 unix_state_lock(sk); 464 if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) 465 goto out_unlock; 466 if (backlog > sk->sk_max_ack_backlog) 467 wake_up_interruptible_all(&u->peer_wait); 468 sk->sk_max_ack_backlog = backlog; 469 sk->sk_state = TCP_LISTEN; 470 /* set credentials so connect can copy them */ 471 sk->sk_peercred.pid = task_tgid_vnr(current); 472 sk->sk_peercred.uid = current->euid; 473 sk->sk_peercred.gid = current->egid; 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_datagram_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_datagram_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_datagram_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_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 return sk; 617} 618 619static int unix_create(struct net *net, struct socket *sock, int protocol) 620{ 621 if (protocol && protocol != PF_UNIX) 622 return -EPROTONOSUPPORT; 623 624 sock->state = SS_UNCONNECTED; 625 626 switch (sock->type) { 627 case SOCK_STREAM: 628 sock->ops = &unix_stream_ops; 629 break; 630 /* 631 * Believe it or not BSD has AF_UNIX, SOCK_RAW though 632 * nothing uses it. 633 */ 634 case SOCK_RAW: 635 sock->type=SOCK_DGRAM; 636 case SOCK_DGRAM: 637 sock->ops = &unix_dgram_ops; 638 break; 639 case SOCK_SEQPACKET: 640 sock->ops = &unix_seqpacket_ops; 641 break; 642 default: 643 return -ESOCKTNOSUPPORT; 644 } 645 646 return unix_create1(net, sock) ? 0 : -ENOMEM; 647} 648 649static int unix_release(struct socket *sock) 650{ 651 struct sock *sk = sock->sk; 652 653 if (!sk) 654 return 0; 655 656 sock->sk = NULL; 657 658 return unix_release_sock (sk, 0); 659} 660 661static int unix_autobind(struct socket *sock) 662{ 663 struct sock *sk = sock->sk; 664 struct net *net = sock_net(sk); 665 struct unix_sock *u = unix_sk(sk); 666 static u32 ordernum = 1; 667 struct unix_address * addr; 668 int err; 669 670 mutex_lock(&u->readlock); 671 672 err = 0; 673 if (u->addr) 674 goto out; 675 676 err = -ENOMEM; 677 addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); 678 if (!addr) 679 goto out; 680 681 addr->name->sun_family = AF_UNIX; 682 atomic_set(&addr->refcnt, 1); 683 684retry: 685 addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); 686 addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0)); 687 688 spin_lock(&unix_table_lock); 689 ordernum = (ordernum+1)&0xFFFFF; 690 691 if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, 692 addr->hash)) { 693 spin_unlock(&unix_table_lock); 694 /* Sanity yield. It is unusual case, but yet... */ 695 if (!(ordernum&0xFF)) 696 yield(); 697 goto retry; 698 } 699 addr->hash ^= sk->sk_type; 700 701 __unix_remove_socket(sk); 702 u->addr = addr; 703 __unix_insert_socket(&unix_socket_table[addr->hash], sk); 704 spin_unlock(&unix_table_lock); 705 err = 0; 706 707out: mutex_unlock(&u->readlock); 708 return err; 709} 710 711static struct sock *unix_find_other(struct net *net, 712 struct sockaddr_un *sunname, int len, 713 int type, unsigned hash, int *error) 714{ 715 struct sock *u; 716 struct nameidata nd; 717 int err = 0; 718 719 if (sunname->sun_path[0]) { 720 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd); 721 if (err) 722 goto fail; 723 err = vfs_permission(&nd, MAY_WRITE); 724 if (err) 725 goto put_fail; 726 727 err = -ECONNREFUSED; 728 if (!S_ISSOCK(nd.path.dentry->d_inode->i_mode)) 729 goto put_fail; 730 u = unix_find_socket_byinode(net, nd.path.dentry->d_inode); 731 if (!u) 732 goto put_fail; 733 734 if (u->sk_type == type) 735 touch_atime(nd.path.mnt, nd.path.dentry); 736 737 path_put(&nd.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(&nd.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 void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1306{ 1307 int i; 1308 for (i=scm->fp->count-1; i>=0; i--) 1309 unix_inflight(scm->fp->fp[i]); 1310 UNIXCB(skb).fp = scm->fp; 1311 skb->destructor = unix_destruct_fds; 1312 scm->fp = NULL; 1313} 1314 1315/* 1316 * Send AF_UNIX data. 1317 */ 1318 1319static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 1320 struct msghdr *msg, size_t len) 1321{ 1322 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1323 struct sock *sk = sock->sk; 1324 struct net *net = sock_net(sk); 1325 struct unix_sock *u = unix_sk(sk); 1326 struct sockaddr_un *sunaddr=msg->msg_name; 1327 struct sock *other = NULL; 1328 int namelen = 0; /* fake GCC */ 1329 int err; 1330 unsigned hash; 1331 struct sk_buff *skb; 1332 long timeo; 1333 struct scm_cookie tmp_scm; 1334 1335 if (NULL == siocb->scm) 1336 siocb->scm = &tmp_scm; 1337 err = scm_send(sock, msg, siocb->scm); 1338 if (err < 0) 1339 return err; 1340 1341 err = -EOPNOTSUPP; 1342 if (msg->msg_flags&MSG_OOB) 1343 goto out; 1344 1345 if (msg->msg_namelen) { 1346 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1347 if (err < 0) 1348 goto out; 1349 namelen = err; 1350 } else { 1351 sunaddr = NULL; 1352 err = -ENOTCONN; 1353 other = unix_peer_get(sk); 1354 if (!other) 1355 goto out; 1356 } 1357 1358 if (test_bit(SOCK_PASSCRED, &sock->flags) 1359 && !u->addr && (err = unix_autobind(sock)) != 0) 1360 goto out; 1361 1362 err = -EMSGSIZE; 1363 if (len > sk->sk_sndbuf - 32) 1364 goto out; 1365 1366 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1367 if (skb==NULL) 1368 goto out; 1369 1370 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1371 if (siocb->scm->fp) 1372 unix_attach_fds(siocb->scm, skb); 1373 unix_get_secdata(siocb->scm, skb); 1374 1375 skb_reset_transport_header(skb); 1376 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); 1377 if (err) 1378 goto out_free; 1379 1380 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1381 1382restart: 1383 if (!other) { 1384 err = -ECONNRESET; 1385 if (sunaddr == NULL) 1386 goto out_free; 1387 1388 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1389 hash, &err); 1390 if (other==NULL) 1391 goto out_free; 1392 } 1393 1394 unix_state_lock(other); 1395 err = -EPERM; 1396 if (!unix_may_send(sk, other)) 1397 goto out_unlock; 1398 1399 if (sock_flag(other, SOCK_DEAD)) { 1400 /* 1401 * Check with 1003.1g - what should 1402 * datagram error 1403 */ 1404 unix_state_unlock(other); 1405 sock_put(other); 1406 1407 err = 0; 1408 unix_state_lock(sk); 1409 if (unix_peer(sk) == other) { 1410 unix_peer(sk)=NULL; 1411 unix_state_unlock(sk); 1412 1413 unix_dgram_disconnected(sk, other); 1414 sock_put(other); 1415 err = -ECONNREFUSED; 1416 } else { 1417 unix_state_unlock(sk); 1418 } 1419 1420 other = NULL; 1421 if (err) 1422 goto out_free; 1423 goto restart; 1424 } 1425 1426 err = -EPIPE; 1427 if (other->sk_shutdown & RCV_SHUTDOWN) 1428 goto out_unlock; 1429 1430 if (sk->sk_type != SOCK_SEQPACKET) { 1431 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1432 if (err) 1433 goto out_unlock; 1434 } 1435 1436 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1437 if (!timeo) { 1438 err = -EAGAIN; 1439 goto out_unlock; 1440 } 1441 1442 timeo = unix_wait_for_peer(other, timeo); 1443 1444 err = sock_intr_errno(timeo); 1445 if (signal_pending(current)) 1446 goto out_free; 1447 1448 goto restart; 1449 } 1450 1451 skb_queue_tail(&other->sk_receive_queue, skb); 1452 unix_state_unlock(other); 1453 other->sk_data_ready(other, len); 1454 sock_put(other); 1455 scm_destroy(siocb->scm); 1456 return len; 1457 1458out_unlock: 1459 unix_state_unlock(other); 1460out_free: 1461 kfree_skb(skb); 1462out: 1463 if (other) 1464 sock_put(other); 1465 scm_destroy(siocb->scm); 1466 return err; 1467} 1468 1469 1470static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1471 struct msghdr *msg, size_t len) 1472{ 1473 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1474 struct sock *sk = sock->sk; 1475 struct sock *other = NULL; 1476 struct sockaddr_un *sunaddr=msg->msg_name; 1477 int err,size; 1478 struct sk_buff *skb; 1479 int sent=0; 1480 struct scm_cookie tmp_scm; 1481 1482 if (NULL == siocb->scm) 1483 siocb->scm = &tmp_scm; 1484 err = scm_send(sock, msg, siocb->scm); 1485 if (err < 0) 1486 return err; 1487 1488 err = -EOPNOTSUPP; 1489 if (msg->msg_flags&MSG_OOB) 1490 goto out_err; 1491 1492 if (msg->msg_namelen) { 1493 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1494 goto out_err; 1495 } else { 1496 sunaddr = NULL; 1497 err = -ENOTCONN; 1498 other = unix_peer(sk); 1499 if (!other) 1500 goto out_err; 1501 } 1502 1503 if (sk->sk_shutdown & SEND_SHUTDOWN) 1504 goto pipe_err; 1505 1506 while(sent < len) 1507 { 1508 /* 1509 * Optimisation for the fact that under 0.01% of X 1510 * messages typically need breaking up. 1511 */ 1512 1513 size = len-sent; 1514 1515 /* Keep two messages in the pipe so it schedules better */ 1516 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1517 size = (sk->sk_sndbuf >> 1) - 64; 1518 1519 if (size > SKB_MAX_ALLOC) 1520 size = SKB_MAX_ALLOC; 1521 1522 /* 1523 * Grab a buffer 1524 */ 1525 1526 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); 1527 1528 if (skb==NULL) 1529 goto out_err; 1530 1531 /* 1532 * If you pass two values to the sock_alloc_send_skb 1533 * it tries to grab the large buffer with GFP_NOFS 1534 * (which can fail easily), and if it fails grab the 1535 * fallback size buffer which is under a page and will 1536 * succeed. [Alan] 1537 */ 1538 size = min_t(int, size, skb_tailroom(skb)); 1539 1540 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1541 if (siocb->scm->fp) 1542 unix_attach_fds(siocb->scm, skb); 1543 1544 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { 1545 kfree_skb(skb); 1546 goto out_err; 1547 } 1548 1549 unix_state_lock(other); 1550 1551 if (sock_flag(other, SOCK_DEAD) || 1552 (other->sk_shutdown & RCV_SHUTDOWN)) 1553 goto pipe_err_free; 1554 1555 skb_queue_tail(&other->sk_receive_queue, skb); 1556 unix_state_unlock(other); 1557 other->sk_data_ready(other, size); 1558 sent+=size; 1559 } 1560 1561 scm_destroy(siocb->scm); 1562 siocb->scm = NULL; 1563 1564 return sent; 1565 1566pipe_err_free: 1567 unix_state_unlock(other); 1568 kfree_skb(skb); 1569pipe_err: 1570 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1571 send_sig(SIGPIPE,current,0); 1572 err = -EPIPE; 1573out_err: 1574 scm_destroy(siocb->scm); 1575 siocb->scm = NULL; 1576 return sent ? : err; 1577} 1578 1579static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1580 struct msghdr *msg, size_t len) 1581{ 1582 int err; 1583 struct sock *sk = sock->sk; 1584 1585 err = sock_error(sk); 1586 if (err) 1587 return err; 1588 1589 if (sk->sk_state != TCP_ESTABLISHED) 1590 return -ENOTCONN; 1591 1592 if (msg->msg_namelen) 1593 msg->msg_namelen = 0; 1594 1595 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1596} 1597 1598static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1599{ 1600 struct unix_sock *u = unix_sk(sk); 1601 1602 msg->msg_namelen = 0; 1603 if (u->addr) { 1604 msg->msg_namelen = u->addr->len; 1605 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1606 } 1607} 1608 1609static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1610 struct msghdr *msg, size_t size, 1611 int flags) 1612{ 1613 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1614 struct scm_cookie tmp_scm; 1615 struct sock *sk = sock->sk; 1616 struct unix_sock *u = unix_sk(sk); 1617 int noblock = flags & MSG_DONTWAIT; 1618 struct sk_buff *skb; 1619 int err; 1620 1621 err = -EOPNOTSUPP; 1622 if (flags&MSG_OOB) 1623 goto out; 1624 1625 msg->msg_namelen = 0; 1626 1627 mutex_lock(&u->readlock); 1628 1629 skb = skb_recv_datagram(sk, flags, noblock, &err); 1630 if (!skb) { 1631 unix_state_lock(sk); 1632 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1633 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1634 (sk->sk_shutdown & RCV_SHUTDOWN)) 1635 err = 0; 1636 unix_state_unlock(sk); 1637 goto out_unlock; 1638 } 1639 1640 wake_up_interruptible_sync(&u->peer_wait); 1641 1642 if (msg->msg_name) 1643 unix_copy_addr(msg, skb->sk); 1644 1645 if (size > skb->len) 1646 size = skb->len; 1647 else if (size < skb->len) 1648 msg->msg_flags |= MSG_TRUNC; 1649 1650 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1651 if (err) 1652 goto out_free; 1653 1654 if (!siocb->scm) { 1655 siocb->scm = &tmp_scm; 1656 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1657 } 1658 siocb->scm->creds = *UNIXCREDS(skb); 1659 unix_set_secdata(siocb->scm, skb); 1660 1661 if (!(flags & MSG_PEEK)) 1662 { 1663 if (UNIXCB(skb).fp) 1664 unix_detach_fds(siocb->scm, skb); 1665 } 1666 else 1667 { 1668 /* It is questionable: on PEEK we could: 1669 - do not return fds - good, but too simple 8) 1670 - return fds, and do not return them on read (old strategy, 1671 apparently wrong) 1672 - clone fds (I chose it for now, it is the most universal 1673 solution) 1674 1675 POSIX 1003.1g does not actually define this clearly 1676 at all. POSIX 1003.1g doesn't define a lot of things 1677 clearly however! 1678 1679 */ 1680 if (UNIXCB(skb).fp) 1681 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1682 } 1683 err = size; 1684 1685 scm_recv(sock, msg, siocb->scm, flags); 1686 1687out_free: 1688 skb_free_datagram(sk,skb); 1689out_unlock: 1690 mutex_unlock(&u->readlock); 1691out: 1692 return err; 1693} 1694 1695/* 1696 * Sleep until data has arrive. But check for races.. 1697 */ 1698 1699static long unix_stream_data_wait(struct sock * sk, long timeo) 1700{ 1701 DEFINE_WAIT(wait); 1702 1703 unix_state_lock(sk); 1704 1705 for (;;) { 1706 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1707 1708 if (!skb_queue_empty(&sk->sk_receive_queue) || 1709 sk->sk_err || 1710 (sk->sk_shutdown & RCV_SHUTDOWN) || 1711 signal_pending(current) || 1712 !timeo) 1713 break; 1714 1715 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1716 unix_state_unlock(sk); 1717 timeo = schedule_timeout(timeo); 1718 unix_state_lock(sk); 1719 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1720 } 1721 1722 finish_wait(sk->sk_sleep, &wait); 1723 unix_state_unlock(sk); 1724 return timeo; 1725} 1726 1727 1728 1729static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1730 struct msghdr *msg, size_t size, 1731 int flags) 1732{ 1733 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1734 struct scm_cookie tmp_scm; 1735 struct sock *sk = sock->sk; 1736 struct unix_sock *u = unix_sk(sk); 1737 struct sockaddr_un *sunaddr=msg->msg_name; 1738 int copied = 0; 1739 int check_creds = 0; 1740 int target; 1741 int err = 0; 1742 long timeo; 1743 1744 err = -EINVAL; 1745 if (sk->sk_state != TCP_ESTABLISHED) 1746 goto out; 1747 1748 err = -EOPNOTSUPP; 1749 if (flags&MSG_OOB) 1750 goto out; 1751 1752 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1753 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1754 1755 msg->msg_namelen = 0; 1756 1757 /* Lock the socket to prevent queue disordering 1758 * while sleeps in memcpy_tomsg 1759 */ 1760 1761 if (!siocb->scm) { 1762 siocb->scm = &tmp_scm; 1763 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1764 } 1765 1766 mutex_lock(&u->readlock); 1767 1768 do 1769 { 1770 int chunk; 1771 struct sk_buff *skb; 1772 1773 unix_state_lock(sk); 1774 skb = skb_dequeue(&sk->sk_receive_queue); 1775 if (skb==NULL) 1776 { 1777 if (copied >= target) 1778 goto unlock; 1779 1780 /* 1781 * POSIX 1003.1g mandates this order. 1782 */ 1783 1784 if ((err = sock_error(sk)) != 0) 1785 goto unlock; 1786 if (sk->sk_shutdown & RCV_SHUTDOWN) 1787 goto unlock; 1788 1789 unix_state_unlock(sk); 1790 err = -EAGAIN; 1791 if (!timeo) 1792 break; 1793 mutex_unlock(&u->readlock); 1794 1795 timeo = unix_stream_data_wait(sk, timeo); 1796 1797 if (signal_pending(current)) { 1798 err = sock_intr_errno(timeo); 1799 goto out; 1800 } 1801 mutex_lock(&u->readlock); 1802 continue; 1803 unlock: 1804 unix_state_unlock(sk); 1805 break; 1806 } 1807 unix_state_unlock(sk); 1808 1809 if (check_creds) { 1810 /* Never glue messages from different writers */ 1811 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { 1812 skb_queue_head(&sk->sk_receive_queue, skb); 1813 break; 1814 } 1815 } else { 1816 /* Copy credentials */ 1817 siocb->scm->creds = *UNIXCREDS(skb); 1818 check_creds = 1; 1819 } 1820 1821 /* Copy address just once */ 1822 if (sunaddr) 1823 { 1824 unix_copy_addr(msg, skb->sk); 1825 sunaddr = NULL; 1826 } 1827 1828 chunk = min_t(unsigned int, skb->len, size); 1829 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1830 skb_queue_head(&sk->sk_receive_queue, skb); 1831 if (copied == 0) 1832 copied = -EFAULT; 1833 break; 1834 } 1835 copied += chunk; 1836 size -= chunk; 1837 1838 /* Mark read part of skb as used */ 1839 if (!(flags & MSG_PEEK)) 1840 { 1841 skb_pull(skb, chunk); 1842 1843 if (UNIXCB(skb).fp) 1844 unix_detach_fds(siocb->scm, skb); 1845 1846 /* put the skb back if we didn't use it up.. */ 1847 if (skb->len) 1848 { 1849 skb_queue_head(&sk->sk_receive_queue, skb); 1850 break; 1851 } 1852 1853 kfree_skb(skb); 1854 1855 if (siocb->scm->fp) 1856 break; 1857 } 1858 else 1859 { 1860 /* It is questionable, see note in unix_dgram_recvmsg. 1861 */ 1862 if (UNIXCB(skb).fp) 1863 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1864 1865 /* put message back and return */ 1866 skb_queue_head(&sk->sk_receive_queue, skb); 1867 break; 1868 } 1869 } while (size); 1870 1871 mutex_unlock(&u->readlock); 1872 scm_recv(sock, msg, siocb->scm, flags); 1873out: 1874 return copied ? : err; 1875} 1876 1877static int unix_shutdown(struct socket *sock, int mode) 1878{ 1879 struct sock *sk = sock->sk; 1880 struct sock *other; 1881 1882 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1883 1884 if (mode) { 1885 unix_state_lock(sk); 1886 sk->sk_shutdown |= mode; 1887 other=unix_peer(sk); 1888 if (other) 1889 sock_hold(other); 1890 unix_state_unlock(sk); 1891 sk->sk_state_change(sk); 1892 1893 if (other && 1894 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1895 1896 int peer_mode = 0; 1897 1898 if (mode&RCV_SHUTDOWN) 1899 peer_mode |= SEND_SHUTDOWN; 1900 if (mode&SEND_SHUTDOWN) 1901 peer_mode |= RCV_SHUTDOWN; 1902 unix_state_lock(other); 1903 other->sk_shutdown |= peer_mode; 1904 unix_state_unlock(other); 1905 other->sk_state_change(other); 1906 read_lock(&other->sk_callback_lock); 1907 if (peer_mode == SHUTDOWN_MASK) 1908 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1909 else if (peer_mode & RCV_SHUTDOWN) 1910 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1911 read_unlock(&other->sk_callback_lock); 1912 } 1913 if (other) 1914 sock_put(other); 1915 } 1916 return 0; 1917} 1918 1919static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1920{ 1921 struct sock *sk = sock->sk; 1922 long amount=0; 1923 int err; 1924 1925 switch(cmd) 1926 { 1927 case SIOCOUTQ: 1928 amount = atomic_read(&sk->sk_wmem_alloc); 1929 err = put_user(amount, (int __user *)arg); 1930 break; 1931 case SIOCINQ: 1932 { 1933 struct sk_buff *skb; 1934 1935 if (sk->sk_state == TCP_LISTEN) { 1936 err = -EINVAL; 1937 break; 1938 } 1939 1940 spin_lock(&sk->sk_receive_queue.lock); 1941 if (sk->sk_type == SOCK_STREAM || 1942 sk->sk_type == SOCK_SEQPACKET) { 1943 skb_queue_walk(&sk->sk_receive_queue, skb) 1944 amount += skb->len; 1945 } else { 1946 skb = skb_peek(&sk->sk_receive_queue); 1947 if (skb) 1948 amount=skb->len; 1949 } 1950 spin_unlock(&sk->sk_receive_queue.lock); 1951 err = put_user(amount, (int __user *)arg); 1952 break; 1953 } 1954 1955 default: 1956 err = -ENOIOCTLCMD; 1957 break; 1958 } 1959 return err; 1960} 1961 1962static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) 1963{ 1964 struct sock *sk = sock->sk; 1965 unsigned int mask; 1966 1967 poll_wait(file, sk->sk_sleep, wait); 1968 mask = 0; 1969 1970 /* exceptional events? */ 1971 if (sk->sk_err) 1972 mask |= POLLERR; 1973 if (sk->sk_shutdown == SHUTDOWN_MASK) 1974 mask |= POLLHUP; 1975 if (sk->sk_shutdown & RCV_SHUTDOWN) 1976 mask |= POLLRDHUP; 1977 1978 /* readable? */ 1979 if (!skb_queue_empty(&sk->sk_receive_queue) || 1980 (sk->sk_shutdown & RCV_SHUTDOWN)) 1981 mask |= POLLIN | POLLRDNORM; 1982 1983 /* Connection-based need to check for termination and startup */ 1984 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) 1985 mask |= POLLHUP; 1986 1987 /* 1988 * we set writable also when the other side has shut down the 1989 * connection. This prevents stuck sockets. 1990 */ 1991 if (unix_writable(sk)) 1992 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 1993 1994 return mask; 1995} 1996 1997static unsigned int unix_datagram_poll(struct file *file, struct socket *sock, 1998 poll_table *wait) 1999{ 2000 struct sock *sk = sock->sk, *peer; 2001 unsigned int mask; 2002 2003 poll_wait(file, sk->sk_sleep, wait); 2004 2005 peer = unix_peer_get(sk); 2006 if (peer) { 2007 if (peer != sk) { 2008 /* 2009 * Writability of a connected socket additionally 2010 * depends on the state of the receive queue of the 2011 * peer. 2012 */ 2013 poll_wait(file, &unix_sk(peer)->peer_wait, wait); 2014 } else { 2015 sock_put(peer); 2016 peer = NULL; 2017 } 2018 } 2019 2020 mask = 0; 2021 2022 /* exceptional events? */ 2023 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2024 mask |= POLLERR; 2025 if (sk->sk_shutdown & RCV_SHUTDOWN) 2026 mask |= POLLRDHUP; 2027 if (sk->sk_shutdown == SHUTDOWN_MASK) 2028 mask |= POLLHUP; 2029 2030 /* readable? */ 2031 if (!skb_queue_empty(&sk->sk_receive_queue) || 2032 (sk->sk_shutdown & RCV_SHUTDOWN)) 2033 mask |= POLLIN | POLLRDNORM; 2034 2035 /* Connection-based need to check for termination and startup */ 2036 if (sk->sk_type == SOCK_SEQPACKET) { 2037 if (sk->sk_state == TCP_CLOSE) 2038 mask |= POLLHUP; 2039 /* connection hasn't started yet? */ 2040 if (sk->sk_state == TCP_SYN_SENT) 2041 return mask; 2042 } 2043 2044 /* writable? */ 2045 if (unix_writable(sk) && !(peer && unix_recvq_full(peer))) 2046 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2047 else 2048 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2049 2050 if (peer) 2051 sock_put(peer); 2052 2053 return mask; 2054} 2055 2056#ifdef CONFIG_PROC_FS 2057static struct sock *first_unix_socket(int *i) 2058{ 2059 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2060 if (!hlist_empty(&unix_socket_table[*i])) 2061 return __sk_head(&unix_socket_table[*i]); 2062 } 2063 return NULL; 2064} 2065 2066static struct sock *next_unix_socket(int *i, struct sock *s) 2067{ 2068 struct sock *next = sk_next(s); 2069 /* More in this chain? */ 2070 if (next) 2071 return next; 2072 /* Look for next non-empty chain. */ 2073 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2074 if (!hlist_empty(&unix_socket_table[*i])) 2075 return __sk_head(&unix_socket_table[*i]); 2076 } 2077 return NULL; 2078} 2079 2080struct unix_iter_state { 2081 struct seq_net_private p; 2082 int i; 2083}; 2084static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2085{ 2086 struct unix_iter_state *iter = seq->private; 2087 loff_t off = 0; 2088 struct sock *s; 2089 2090 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2091 if (sock_net(s) != seq_file_net(seq)) 2092 continue; 2093 if (off == pos) 2094 return s; 2095 ++off; 2096 } 2097 return NULL; 2098} 2099 2100 2101static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2102 __acquires(unix_table_lock) 2103{ 2104 spin_lock(&unix_table_lock); 2105 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2106} 2107 2108static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2109{ 2110 struct unix_iter_state *iter = seq->private; 2111 struct sock *sk = v; 2112 ++*pos; 2113 2114 if (v == SEQ_START_TOKEN) 2115 sk = first_unix_socket(&iter->i); 2116 else 2117 sk = next_unix_socket(&iter->i, sk); 2118 while (sk && (sock_net(sk) != seq_file_net(seq))) 2119 sk = next_unix_socket(&iter->i, sk); 2120 return sk; 2121} 2122 2123static void unix_seq_stop(struct seq_file *seq, void *v) 2124 __releases(unix_table_lock) 2125{ 2126 spin_unlock(&unix_table_lock); 2127} 2128 2129static int unix_seq_show(struct seq_file *seq, void *v) 2130{ 2131 2132 if (v == SEQ_START_TOKEN) 2133 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2134 "Inode Path\n"); 2135 else { 2136 struct sock *s = v; 2137 struct unix_sock *u = unix_sk(s); 2138 unix_state_lock(s); 2139 2140 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2141 s, 2142 atomic_read(&s->sk_refcnt), 2143 0, 2144 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2145 s->sk_type, 2146 s->sk_socket ? 2147 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2148 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2149 sock_i_ino(s)); 2150 2151 if (u->addr) { 2152 int i, len; 2153 seq_putc(seq, ' '); 2154 2155 i = 0; 2156 len = u->addr->len - sizeof(short); 2157 if (!UNIX_ABSTRACT(s)) 2158 len--; 2159 else { 2160 seq_putc(seq, '@'); 2161 i++; 2162 } 2163 for ( ; i < len; i++) 2164 seq_putc(seq, u->addr->name->sun_path[i]); 2165 } 2166 unix_state_unlock(s); 2167 seq_putc(seq, '\n'); 2168 } 2169 2170 return 0; 2171} 2172 2173static const struct seq_operations unix_seq_ops = { 2174 .start = unix_seq_start, 2175 .next = unix_seq_next, 2176 .stop = unix_seq_stop, 2177 .show = unix_seq_show, 2178}; 2179 2180 2181static int unix_seq_open(struct inode *inode, struct file *file) 2182{ 2183 return seq_open_net(inode, file, &unix_seq_ops, 2184 sizeof(struct unix_iter_state)); 2185} 2186 2187static const struct file_operations unix_seq_fops = { 2188 .owner = THIS_MODULE, 2189 .open = unix_seq_open, 2190 .read = seq_read, 2191 .llseek = seq_lseek, 2192 .release = seq_release_net, 2193}; 2194 2195#endif 2196 2197static struct net_proto_family unix_family_ops = { 2198 .family = PF_UNIX, 2199 .create = unix_create, 2200 .owner = THIS_MODULE, 2201}; 2202 2203 2204static int unix_net_init(struct net *net) 2205{ 2206 int error = -ENOMEM; 2207 2208 net->unx.sysctl_max_dgram_qlen = 10; 2209 if (unix_sysctl_register(net)) 2210 goto out; 2211 2212#ifdef CONFIG_PROC_FS 2213 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2214 unix_sysctl_unregister(net); 2215 goto out; 2216 } 2217#endif 2218 error = 0; 2219out: 2220 return 0; 2221} 2222 2223static void unix_net_exit(struct net *net) 2224{ 2225 unix_sysctl_unregister(net); 2226 proc_net_remove(net, "unix"); 2227} 2228 2229static struct pernet_operations unix_net_ops = { 2230 .init = unix_net_init, 2231 .exit = unix_net_exit, 2232}; 2233 2234static int __init af_unix_init(void) 2235{ 2236 int rc = -1; 2237 struct sk_buff *dummy_skb; 2238 2239 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2240 2241 rc = proto_register(&unix_proto, 1); 2242 if (rc != 0) { 2243 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2244 __func__); 2245 goto out; 2246 } 2247 2248 sock_register(&unix_family_ops); 2249 register_pernet_subsys(&unix_net_ops); 2250out: 2251 return rc; 2252} 2253 2254static void __exit af_unix_exit(void) 2255{ 2256 sock_unregister(PF_UNIX); 2257 proto_unregister(&unix_proto); 2258 unregister_pernet_subsys(&unix_net_ops); 2259} 2260 2261/* Earlier than device_initcall() so that other drivers invoking 2262 request_module() don't end up in a loop when modprobe tries 2263 to use a UNIX socket. But later than subsys_initcall() because 2264 we depend on stuff initialised there */ 2265fs_initcall(af_unix_init); 2266module_exit(af_unix_exit); 2267 2268MODULE_LICENSE("GPL"); 2269MODULE_ALIAS_NETPROTO(PF_UNIX); 2270