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 * 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> 117 118 static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; 119 static DEFINE_SPINLOCK(unix_table_lock); 120 static 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 127 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 128 { 129 memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); 130 } 131 132 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) 133 { 134 scm->secid = *UNIXSID(skb); 135 } 136 #else 137 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) 138 { } 139 140 static 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 */ 149 150 static 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) 159 160 static inline int unix_our_peer(struct sock *sk, struct sock *osk) 161 { 162 return unix_peer(osk) == sk; 163 } 164 165 static inline int unix_may_send(struct sock *sk, struct sock *osk) 166 { 167 return (unix_peer(osk) == NULL || unix_our_peer(sk, osk)); 168 } 169 170 static 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 } 174 175 static 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 } 186 187 static 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 */ 199 200 static 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 } 222 223 static void __unix_remove_socket(struct sock *sk) 224 { 225 sk_del_node_init(sk); 226 } 227 228 static 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 } 233 234 static 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 } 240 241 static 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 } 247 248 static 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; 266 found: 267 return s; 268 } 269 270 static 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 } 284 285 static 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; 305 found: 306 spin_unlock(&unix_table_lock); 307 return s; 308 } 309 310 static inline int unix_writable(struct sock *sk) 311 { 312 return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; 313 } 314 315 static 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. */ 330 static 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 } 346 347 static 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 } 369 370 static 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 } 448 449 static 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; 473 474 out_unlock: 475 unix_state_unlock(sk); 476 out: 477 return err; 478 } 479 480 static int unix_release(struct socket *); 481 static int unix_bind(struct socket *, struct sockaddr *, int); 482 static int unix_stream_connect(struct socket *, struct sockaddr *, 483 int addr_len, int flags); 484 static int unix_socketpair(struct socket *, struct socket *); 485 static int unix_accept(struct socket *, struct socket *, int); 486 static int unix_getname(struct socket *, struct sockaddr *, int *, int); 487 static unsigned int unix_poll(struct file *, struct socket *, poll_table *); 488 static unsigned int unix_dgram_poll(struct file *, struct socket *, 489 poll_table *); 490 static int unix_ioctl(struct socket *, unsigned int, unsigned long); 491 static int unix_shutdown(struct socket *, int); 492 static int unix_stream_sendmsg(struct kiocb *, struct socket *, 493 struct msghdr *, size_t); 494 static int unix_stream_recvmsg(struct kiocb *, struct socket *, 495 struct msghdr *, size_t, int); 496 static int unix_dgram_sendmsg(struct kiocb *, struct socket *, 497 struct msghdr *, size_t); 498 static int unix_dgram_recvmsg(struct kiocb *, struct socket *, 499 struct msghdr *, size_t, int); 500 static int unix_dgram_connect(struct socket *, struct sockaddr *, 501 int, int); 502 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, 503 struct msghdr *, size_t); 504 505 static 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 }; 525 526 static 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 }; 546 547 static 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 }; 567 568 static 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 */ 580 static struct lock_class_key af_unix_sk_receive_queue_lock_key; 581 582 static 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); 611 out: 612 if (sk == NULL) 613 atomic_dec(&unix_nr_socks); 614 return sk; 615 } 616 617 static 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 } 646 647 static 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 } 658 659 static 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); 681 682 retry: 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; 704 705 out: mutex_unlock(&u->readlock); 706 return err; 707 } 708 709 static 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 nameidata nd; 715 int err = 0; 716 717 if (sunname->sun_path[0]) { 718 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd); 719 if (err) 720 goto fail; 721 err = vfs_permission(&nd, MAY_WRITE); 722 if (err) 723 goto put_fail; 724 725 err = -ECONNREFUSED; 726 if (!S_ISSOCK(nd.path.dentry->d_inode->i_mode)) 727 goto put_fail; 728 u = unix_find_socket_byinode(net, nd.path.dentry->d_inode); 729 if (!u) 730 goto put_fail; 731 732 if (u->sk_type == type) 733 touch_atime(nd.path.mnt, nd.path.dentry); 734 735 path_put(&nd.path); 736 737 err=-EPROTOTYPE; 738 if (u->sk_type != type) { 739 sock_put(u); 740 goto fail; 741 } 742 } else { 743 err = -ECONNREFUSED; 744 u=unix_find_socket_byname(net, sunname, len, type, hash); 745 if (u) { 746 struct dentry *dentry; 747 dentry = unix_sk(u)->dentry; 748 if (dentry) 749 touch_atime(unix_sk(u)->mnt, dentry); 750 } else 751 goto fail; 752 } 753 return u; 754 755 put_fail: 756 path_put(&nd.path); 757 fail: 758 *error=err; 759 return NULL; 760 } 761 762 763 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 764 { 765 struct sock *sk = sock->sk; 766 struct net *net = sock_net(sk); 767 struct unix_sock *u = unix_sk(sk); 768 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; 769 struct dentry * dentry = NULL; 770 struct nameidata nd; 771 int err; 772 unsigned hash; 773 struct unix_address *addr; 774 struct hlist_head *list; 775 776 err = -EINVAL; 777 if (sunaddr->sun_family != AF_UNIX) 778 goto out; 779 780 if (addr_len==sizeof(short)) { 781 err = unix_autobind(sock); 782 goto out; 783 } 784 785 err = unix_mkname(sunaddr, addr_len, &hash); 786 if (err < 0) 787 goto out; 788 addr_len = err; 789 790 mutex_lock(&u->readlock); 791 792 err = -EINVAL; 793 if (u->addr) 794 goto out_up; 795 796 err = -ENOMEM; 797 addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); 798 if (!addr) 799 goto out_up; 800 801 memcpy(addr->name, sunaddr, addr_len); 802 addr->len = addr_len; 803 addr->hash = hash ^ sk->sk_type; 804 atomic_set(&addr->refcnt, 1); 805 806 if (sunaddr->sun_path[0]) { 807 unsigned int mode; 808 err = 0; 809 /* 810 * Get the parent directory, calculate the hash for last 811 * component. 812 */ 813 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); 814 if (err) 815 goto out_mknod_parent; 816 817 dentry = lookup_create(&nd, 0); 818 err = PTR_ERR(dentry); 819 if (IS_ERR(dentry)) 820 goto out_mknod_unlock; 821 822 /* 823 * All right, let's create it. 824 */ 825 mode = S_IFSOCK | 826 (SOCK_INODE(sock)->i_mode & ~current->fs->umask); 827 err = mnt_want_write(nd.path.mnt); 828 if (err) 829 goto out_mknod_dput; 830 err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); 831 mnt_drop_write(nd.path.mnt); 832 if (err) 833 goto out_mknod_dput; 834 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 835 dput(nd.path.dentry); 836 nd.path.dentry = dentry; 837 838 addr->hash = UNIX_HASH_SIZE; 839 } 840 841 spin_lock(&unix_table_lock); 842 843 if (!sunaddr->sun_path[0]) { 844 err = -EADDRINUSE; 845 if (__unix_find_socket_byname(net, sunaddr, addr_len, 846 sk->sk_type, hash)) { 847 unix_release_addr(addr); 848 goto out_unlock; 849 } 850 851 list = &unix_socket_table[addr->hash]; 852 } else { 853 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; 854 u->dentry = nd.path.dentry; 855 u->mnt = nd.path.mnt; 856 } 857 858 err = 0; 859 __unix_remove_socket(sk); 860 u->addr = addr; 861 __unix_insert_socket(list, sk); 862 863 out_unlock: 864 spin_unlock(&unix_table_lock); 865 out_up: 866 mutex_unlock(&u->readlock); 867 out: 868 return err; 869 870 out_mknod_dput: 871 dput(dentry); 872 out_mknod_unlock: 873 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 874 path_put(&nd.path); 875 out_mknod_parent: 876 if (err==-EEXIST) 877 err=-EADDRINUSE; 878 unix_release_addr(addr); 879 goto out_up; 880 } 881 882 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) 883 { 884 if (unlikely(sk1 == sk2) || !sk2) { 885 unix_state_lock(sk1); 886 return; 887 } 888 if (sk1 < sk2) { 889 unix_state_lock(sk1); 890 unix_state_lock_nested(sk2); 891 } else { 892 unix_state_lock(sk2); 893 unix_state_lock_nested(sk1); 894 } 895 } 896 897 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) 898 { 899 if (unlikely(sk1 == sk2) || !sk2) { 900 unix_state_unlock(sk1); 901 return; 902 } 903 unix_state_unlock(sk1); 904 unix_state_unlock(sk2); 905 } 906 907 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 908 int alen, int flags) 909 { 910 struct sock *sk = sock->sk; 911 struct net *net = sock_net(sk); 912 struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr; 913 struct sock *other; 914 unsigned hash; 915 int err; 916 917 if (addr->sa_family != AF_UNSPEC) { 918 err = unix_mkname(sunaddr, alen, &hash); 919 if (err < 0) 920 goto out; 921 alen = err; 922 923 if (test_bit(SOCK_PASSCRED, &sock->flags) && 924 !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) 925 goto out; 926 927 restart: 928 other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err); 929 if (!other) 930 goto out; 931 932 unix_state_double_lock(sk, other); 933 934 /* Apparently VFS overslept socket death. Retry. */ 935 if (sock_flag(other, SOCK_DEAD)) { 936 unix_state_double_unlock(sk, other); 937 sock_put(other); 938 goto restart; 939 } 940 941 err = -EPERM; 942 if (!unix_may_send(sk, other)) 943 goto out_unlock; 944 945 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 946 if (err) 947 goto out_unlock; 948 949 } else { 950 /* 951 * 1003.1g breaking connected state with AF_UNSPEC 952 */ 953 other = NULL; 954 unix_state_double_lock(sk, other); 955 } 956 957 /* 958 * If it was connected, reconnect. 959 */ 960 if (unix_peer(sk)) { 961 struct sock *old_peer = unix_peer(sk); 962 unix_peer(sk)=other; 963 unix_state_double_unlock(sk, other); 964 965 if (other != old_peer) 966 unix_dgram_disconnected(sk, old_peer); 967 sock_put(old_peer); 968 } else { 969 unix_peer(sk)=other; 970 unix_state_double_unlock(sk, other); 971 } 972 return 0; 973 974 out_unlock: 975 unix_state_double_unlock(sk, other); 976 sock_put(other); 977 out: 978 return err; 979 } 980 981 static long unix_wait_for_peer(struct sock *other, long timeo) 982 { 983 struct unix_sock *u = unix_sk(other); 984 int sched; 985 DEFINE_WAIT(wait); 986 987 prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); 988 989 sched = !sock_flag(other, SOCK_DEAD) && 990 !(other->sk_shutdown & RCV_SHUTDOWN) && 991 unix_recvq_full(other); 992 993 unix_state_unlock(other); 994 995 if (sched) 996 timeo = schedule_timeout(timeo); 997 998 finish_wait(&u->peer_wait, &wait); 999 return timeo; 1000 } 1001 1002 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, 1003 int addr_len, int flags) 1004 { 1005 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; 1006 struct sock *sk = sock->sk; 1007 struct net *net = sock_net(sk); 1008 struct unix_sock *u = unix_sk(sk), *newu, *otheru; 1009 struct sock *newsk = NULL; 1010 struct sock *other = NULL; 1011 struct sk_buff *skb = NULL; 1012 unsigned hash; 1013 int st; 1014 int err; 1015 long timeo; 1016 1017 err = unix_mkname(sunaddr, addr_len, &hash); 1018 if (err < 0) 1019 goto out; 1020 addr_len = err; 1021 1022 if (test_bit(SOCK_PASSCRED, &sock->flags) 1023 && !u->addr && (err = unix_autobind(sock)) != 0) 1024 goto out; 1025 1026 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 1027 1028 /* First of all allocate resources. 1029 If we will make it after state is locked, 1030 we will have to recheck all again in any case. 1031 */ 1032 1033 err = -ENOMEM; 1034 1035 /* create new sock for complete connection */ 1036 newsk = unix_create1(sock_net(sk), NULL); 1037 if (newsk == NULL) 1038 goto out; 1039 1040 /* Allocate skb for sending to listening sock */ 1041 skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); 1042 if (skb == NULL) 1043 goto out; 1044 1045 restart: 1046 /* Find listening sock. */ 1047 other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); 1048 if (!other) 1049 goto out; 1050 1051 /* Latch state of peer */ 1052 unix_state_lock(other); 1053 1054 /* Apparently VFS overslept socket death. Retry. */ 1055 if (sock_flag(other, SOCK_DEAD)) { 1056 unix_state_unlock(other); 1057 sock_put(other); 1058 goto restart; 1059 } 1060 1061 err = -ECONNREFUSED; 1062 if (other->sk_state != TCP_LISTEN) 1063 goto out_unlock; 1064 1065 if (unix_recvq_full(other)) { 1066 err = -EAGAIN; 1067 if (!timeo) 1068 goto out_unlock; 1069 1070 timeo = unix_wait_for_peer(other, timeo); 1071 1072 err = sock_intr_errno(timeo); 1073 if (signal_pending(current)) 1074 goto out; 1075 sock_put(other); 1076 goto restart; 1077 } 1078 1079 /* Latch our state. 1080 1081 It is tricky place. We need to grab write lock and cannot 1082 drop lock on peer. It is dangerous because deadlock is 1083 possible. Connect to self case and simultaneous 1084 attempt to connect are eliminated by checking socket 1085 state. other is TCP_LISTEN, if sk is TCP_LISTEN we 1086 check this before attempt to grab lock. 1087 1088 Well, and we have to recheck the state after socket locked. 1089 */ 1090 st = sk->sk_state; 1091 1092 switch (st) { 1093 case TCP_CLOSE: 1094 /* This is ok... continue with connect */ 1095 break; 1096 case TCP_ESTABLISHED: 1097 /* Socket is already connected */ 1098 err = -EISCONN; 1099 goto out_unlock; 1100 default: 1101 err = -EINVAL; 1102 goto out_unlock; 1103 } 1104 1105 unix_state_lock_nested(sk); 1106 1107 if (sk->sk_state != st) { 1108 unix_state_unlock(sk); 1109 unix_state_unlock(other); 1110 sock_put(other); 1111 goto restart; 1112 } 1113 1114 err = security_unix_stream_connect(sock, other->sk_socket, newsk); 1115 if (err) { 1116 unix_state_unlock(sk); 1117 goto out_unlock; 1118 } 1119 1120 /* The way is open! Fastly set all the necessary fields... */ 1121 1122 sock_hold(sk); 1123 unix_peer(newsk) = sk; 1124 newsk->sk_state = TCP_ESTABLISHED; 1125 newsk->sk_type = sk->sk_type; 1126 newsk->sk_peercred.pid = task_tgid_vnr(current); 1127 newsk->sk_peercred.uid = current->euid; 1128 newsk->sk_peercred.gid = current->egid; 1129 newu = unix_sk(newsk); 1130 newsk->sk_sleep = &newu->peer_wait; 1131 otheru = unix_sk(other); 1132 1133 /* copy address information from listening to new sock*/ 1134 if (otheru->addr) { 1135 atomic_inc(&otheru->addr->refcnt); 1136 newu->addr = otheru->addr; 1137 } 1138 if (otheru->dentry) { 1139 newu->dentry = dget(otheru->dentry); 1140 newu->mnt = mntget(otheru->mnt); 1141 } 1142 1143 /* Set credentials */ 1144 sk->sk_peercred = other->sk_peercred; 1145 1146 sock->state = SS_CONNECTED; 1147 sk->sk_state = TCP_ESTABLISHED; 1148 sock_hold(newsk); 1149 1150 smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ 1151 unix_peer(sk) = newsk; 1152 1153 unix_state_unlock(sk); 1154 1155 /* take ten and and send info to listening sock */ 1156 spin_lock(&other->sk_receive_queue.lock); 1157 __skb_queue_tail(&other->sk_receive_queue, skb); 1158 spin_unlock(&other->sk_receive_queue.lock); 1159 unix_state_unlock(other); 1160 other->sk_data_ready(other, 0); 1161 sock_put(other); 1162 return 0; 1163 1164 out_unlock: 1165 if (other) 1166 unix_state_unlock(other); 1167 1168 out: 1169 if (skb) 1170 kfree_skb(skb); 1171 if (newsk) 1172 unix_release_sock(newsk, 0); 1173 if (other) 1174 sock_put(other); 1175 return err; 1176 } 1177 1178 static int unix_socketpair(struct socket *socka, struct socket *sockb) 1179 { 1180 struct sock *ska=socka->sk, *skb = sockb->sk; 1181 1182 /* Join our sockets back to back */ 1183 sock_hold(ska); 1184 sock_hold(skb); 1185 unix_peer(ska)=skb; 1186 unix_peer(skb)=ska; 1187 ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current); 1188 ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid; 1189 ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid; 1190 1191 if (ska->sk_type != SOCK_DGRAM) { 1192 ska->sk_state = TCP_ESTABLISHED; 1193 skb->sk_state = TCP_ESTABLISHED; 1194 socka->state = SS_CONNECTED; 1195 sockb->state = SS_CONNECTED; 1196 } 1197 return 0; 1198 } 1199 1200 static int unix_accept(struct socket *sock, struct socket *newsock, int flags) 1201 { 1202 struct sock *sk = sock->sk; 1203 struct sock *tsk; 1204 struct sk_buff *skb; 1205 int err; 1206 1207 err = -EOPNOTSUPP; 1208 if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET) 1209 goto out; 1210 1211 err = -EINVAL; 1212 if (sk->sk_state != TCP_LISTEN) 1213 goto out; 1214 1215 /* If socket state is TCP_LISTEN it cannot change (for now...), 1216 * so that no locks are necessary. 1217 */ 1218 1219 skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); 1220 if (!skb) { 1221 /* This means receive shutdown. */ 1222 if (err == 0) 1223 err = -EINVAL; 1224 goto out; 1225 } 1226 1227 tsk = skb->sk; 1228 skb_free_datagram(sk, skb); 1229 wake_up_interruptible(&unix_sk(sk)->peer_wait); 1230 1231 /* attach accepted sock to socket */ 1232 unix_state_lock(tsk); 1233 newsock->state = SS_CONNECTED; 1234 sock_graft(tsk, newsock); 1235 unix_state_unlock(tsk); 1236 return 0; 1237 1238 out: 1239 return err; 1240 } 1241 1242 1243 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) 1244 { 1245 struct sock *sk = sock->sk; 1246 struct unix_sock *u; 1247 struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr; 1248 int err = 0; 1249 1250 if (peer) { 1251 sk = unix_peer_get(sk); 1252 1253 err = -ENOTCONN; 1254 if (!sk) 1255 goto out; 1256 err = 0; 1257 } else { 1258 sock_hold(sk); 1259 } 1260 1261 u = unix_sk(sk); 1262 unix_state_lock(sk); 1263 if (!u->addr) { 1264 sunaddr->sun_family = AF_UNIX; 1265 sunaddr->sun_path[0] = 0; 1266 *uaddr_len = sizeof(short); 1267 } else { 1268 struct unix_address *addr = u->addr; 1269 1270 *uaddr_len = addr->len; 1271 memcpy(sunaddr, addr->name, *uaddr_len); 1272 } 1273 unix_state_unlock(sk); 1274 sock_put(sk); 1275 out: 1276 return err; 1277 } 1278 1279 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1280 { 1281 int i; 1282 1283 scm->fp = UNIXCB(skb).fp; 1284 skb->destructor = sock_wfree; 1285 UNIXCB(skb).fp = NULL; 1286 1287 for (i=scm->fp->count-1; i>=0; i--) 1288 unix_notinflight(scm->fp->fp[i]); 1289 } 1290 1291 static void unix_destruct_fds(struct sk_buff *skb) 1292 { 1293 struct scm_cookie scm; 1294 memset(&scm, 0, sizeof(scm)); 1295 unix_detach_fds(&scm, skb); 1296 1297 /* Alas, it calls VFS */ 1298 /* So fscking what? fput() had been SMP-safe since the last Summer */ 1299 scm_destroy(&scm); 1300 sock_wfree(skb); 1301 } 1302 1303 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) 1304 { 1305 int i; 1306 for (i=scm->fp->count-1; i>=0; i--) 1307 unix_inflight(scm->fp->fp[i]); 1308 UNIXCB(skb).fp = scm->fp; 1309 skb->destructor = unix_destruct_fds; 1310 scm->fp = NULL; 1311 } 1312 1313 /* 1314 * Send AF_UNIX data. 1315 */ 1316 1317 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 1318 struct msghdr *msg, size_t len) 1319 { 1320 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1321 struct sock *sk = sock->sk; 1322 struct net *net = sock_net(sk); 1323 struct unix_sock *u = unix_sk(sk); 1324 struct sockaddr_un *sunaddr=msg->msg_name; 1325 struct sock *other = NULL; 1326 int namelen = 0; /* fake GCC */ 1327 int err; 1328 unsigned hash; 1329 struct sk_buff *skb; 1330 long timeo; 1331 struct scm_cookie tmp_scm; 1332 1333 if (NULL == siocb->scm) 1334 siocb->scm = &tmp_scm; 1335 err = scm_send(sock, msg, siocb->scm); 1336 if (err < 0) 1337 return err; 1338 1339 err = -EOPNOTSUPP; 1340 if (msg->msg_flags&MSG_OOB) 1341 goto out; 1342 1343 if (msg->msg_namelen) { 1344 err = unix_mkname(sunaddr, msg->msg_namelen, &hash); 1345 if (err < 0) 1346 goto out; 1347 namelen = err; 1348 } else { 1349 sunaddr = NULL; 1350 err = -ENOTCONN; 1351 other = unix_peer_get(sk); 1352 if (!other) 1353 goto out; 1354 } 1355 1356 if (test_bit(SOCK_PASSCRED, &sock->flags) 1357 && !u->addr && (err = unix_autobind(sock)) != 0) 1358 goto out; 1359 1360 err = -EMSGSIZE; 1361 if (len > sk->sk_sndbuf - 32) 1362 goto out; 1363 1364 skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); 1365 if (skb==NULL) 1366 goto out; 1367 1368 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1369 if (siocb->scm->fp) 1370 unix_attach_fds(siocb->scm, skb); 1371 unix_get_secdata(siocb->scm, skb); 1372 1373 skb_reset_transport_header(skb); 1374 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); 1375 if (err) 1376 goto out_free; 1377 1378 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1379 1380 restart: 1381 if (!other) { 1382 err = -ECONNRESET; 1383 if (sunaddr == NULL) 1384 goto out_free; 1385 1386 other = unix_find_other(net, sunaddr, namelen, sk->sk_type, 1387 hash, &err); 1388 if (other==NULL) 1389 goto out_free; 1390 } 1391 1392 unix_state_lock(other); 1393 err = -EPERM; 1394 if (!unix_may_send(sk, other)) 1395 goto out_unlock; 1396 1397 if (sock_flag(other, SOCK_DEAD)) { 1398 /* 1399 * Check with 1003.1g - what should 1400 * datagram error 1401 */ 1402 unix_state_unlock(other); 1403 sock_put(other); 1404 1405 err = 0; 1406 unix_state_lock(sk); 1407 if (unix_peer(sk) == other) { 1408 unix_peer(sk)=NULL; 1409 unix_state_unlock(sk); 1410 1411 unix_dgram_disconnected(sk, other); 1412 sock_put(other); 1413 err = -ECONNREFUSED; 1414 } else { 1415 unix_state_unlock(sk); 1416 } 1417 1418 other = NULL; 1419 if (err) 1420 goto out_free; 1421 goto restart; 1422 } 1423 1424 err = -EPIPE; 1425 if (other->sk_shutdown & RCV_SHUTDOWN) 1426 goto out_unlock; 1427 1428 if (sk->sk_type != SOCK_SEQPACKET) { 1429 err = security_unix_may_send(sk->sk_socket, other->sk_socket); 1430 if (err) 1431 goto out_unlock; 1432 } 1433 1434 if (unix_peer(other) != sk && unix_recvq_full(other)) { 1435 if (!timeo) { 1436 err = -EAGAIN; 1437 goto out_unlock; 1438 } 1439 1440 timeo = unix_wait_for_peer(other, timeo); 1441 1442 err = sock_intr_errno(timeo); 1443 if (signal_pending(current)) 1444 goto out_free; 1445 1446 goto restart; 1447 } 1448 1449 skb_queue_tail(&other->sk_receive_queue, skb); 1450 unix_state_unlock(other); 1451 other->sk_data_ready(other, len); 1452 sock_put(other); 1453 scm_destroy(siocb->scm); 1454 return len; 1455 1456 out_unlock: 1457 unix_state_unlock(other); 1458 out_free: 1459 kfree_skb(skb); 1460 out: 1461 if (other) 1462 sock_put(other); 1463 scm_destroy(siocb->scm); 1464 return err; 1465 } 1466 1467 1468 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 1469 struct msghdr *msg, size_t len) 1470 { 1471 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1472 struct sock *sk = sock->sk; 1473 struct sock *other = NULL; 1474 struct sockaddr_un *sunaddr=msg->msg_name; 1475 int err,size; 1476 struct sk_buff *skb; 1477 int sent=0; 1478 struct scm_cookie tmp_scm; 1479 1480 if (NULL == siocb->scm) 1481 siocb->scm = &tmp_scm; 1482 err = scm_send(sock, msg, siocb->scm); 1483 if (err < 0) 1484 return err; 1485 1486 err = -EOPNOTSUPP; 1487 if (msg->msg_flags&MSG_OOB) 1488 goto out_err; 1489 1490 if (msg->msg_namelen) { 1491 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; 1492 goto out_err; 1493 } else { 1494 sunaddr = NULL; 1495 err = -ENOTCONN; 1496 other = unix_peer(sk); 1497 if (!other) 1498 goto out_err; 1499 } 1500 1501 if (sk->sk_shutdown & SEND_SHUTDOWN) 1502 goto pipe_err; 1503 1504 while(sent < len) 1505 { 1506 /* 1507 * Optimisation for the fact that under 0.01% of X 1508 * messages typically need breaking up. 1509 */ 1510 1511 size = len-sent; 1512 1513 /* Keep two messages in the pipe so it schedules better */ 1514 if (size > ((sk->sk_sndbuf >> 1) - 64)) 1515 size = (sk->sk_sndbuf >> 1) - 64; 1516 1517 if (size > SKB_MAX_ALLOC) 1518 size = SKB_MAX_ALLOC; 1519 1520 /* 1521 * Grab a buffer 1522 */ 1523 1524 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err); 1525 1526 if (skb==NULL) 1527 goto out_err; 1528 1529 /* 1530 * If you pass two values to the sock_alloc_send_skb 1531 * it tries to grab the large buffer with GFP_NOFS 1532 * (which can fail easily), and if it fails grab the 1533 * fallback size buffer which is under a page and will 1534 * succeed. [Alan] 1535 */ 1536 size = min_t(int, size, skb_tailroom(skb)); 1537 1538 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1539 if (siocb->scm->fp) 1540 unix_attach_fds(siocb->scm, skb); 1541 1542 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) { 1543 kfree_skb(skb); 1544 goto out_err; 1545 } 1546 1547 unix_state_lock(other); 1548 1549 if (sock_flag(other, SOCK_DEAD) || 1550 (other->sk_shutdown & RCV_SHUTDOWN)) 1551 goto pipe_err_free; 1552 1553 skb_queue_tail(&other->sk_receive_queue, skb); 1554 unix_state_unlock(other); 1555 other->sk_data_ready(other, size); 1556 sent+=size; 1557 } 1558 1559 scm_destroy(siocb->scm); 1560 siocb->scm = NULL; 1561 1562 return sent; 1563 1564 pipe_err_free: 1565 unix_state_unlock(other); 1566 kfree_skb(skb); 1567 pipe_err: 1568 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1569 send_sig(SIGPIPE,current,0); 1570 err = -EPIPE; 1571 out_err: 1572 scm_destroy(siocb->scm); 1573 siocb->scm = NULL; 1574 return sent ? : err; 1575 } 1576 1577 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, 1578 struct msghdr *msg, size_t len) 1579 { 1580 int err; 1581 struct sock *sk = sock->sk; 1582 1583 err = sock_error(sk); 1584 if (err) 1585 return err; 1586 1587 if (sk->sk_state != TCP_ESTABLISHED) 1588 return -ENOTCONN; 1589 1590 if (msg->msg_namelen) 1591 msg->msg_namelen = 0; 1592 1593 return unix_dgram_sendmsg(kiocb, sock, msg, len); 1594 } 1595 1596 static void unix_copy_addr(struct msghdr *msg, struct sock *sk) 1597 { 1598 struct unix_sock *u = unix_sk(sk); 1599 1600 msg->msg_namelen = 0; 1601 if (u->addr) { 1602 msg->msg_namelen = u->addr->len; 1603 memcpy(msg->msg_name, u->addr->name, u->addr->len); 1604 } 1605 } 1606 1607 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 1608 struct msghdr *msg, size_t size, 1609 int flags) 1610 { 1611 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1612 struct scm_cookie tmp_scm; 1613 struct sock *sk = sock->sk; 1614 struct unix_sock *u = unix_sk(sk); 1615 int noblock = flags & MSG_DONTWAIT; 1616 struct sk_buff *skb; 1617 int err; 1618 1619 err = -EOPNOTSUPP; 1620 if (flags&MSG_OOB) 1621 goto out; 1622 1623 msg->msg_namelen = 0; 1624 1625 mutex_lock(&u->readlock); 1626 1627 skb = skb_recv_datagram(sk, flags, noblock, &err); 1628 if (!skb) { 1629 unix_state_lock(sk); 1630 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ 1631 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && 1632 (sk->sk_shutdown & RCV_SHUTDOWN)) 1633 err = 0; 1634 unix_state_unlock(sk); 1635 goto out_unlock; 1636 } 1637 1638 wake_up_interruptible_sync(&u->peer_wait); 1639 1640 if (msg->msg_name) 1641 unix_copy_addr(msg, skb->sk); 1642 1643 if (size > skb->len) 1644 size = skb->len; 1645 else if (size < skb->len) 1646 msg->msg_flags |= MSG_TRUNC; 1647 1648 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size); 1649 if (err) 1650 goto out_free; 1651 1652 if (!siocb->scm) { 1653 siocb->scm = &tmp_scm; 1654 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1655 } 1656 siocb->scm->creds = *UNIXCREDS(skb); 1657 unix_set_secdata(siocb->scm, skb); 1658 1659 if (!(flags & MSG_PEEK)) 1660 { 1661 if (UNIXCB(skb).fp) 1662 unix_detach_fds(siocb->scm, skb); 1663 } 1664 else 1665 { 1666 /* It is questionable: on PEEK we could: 1667 - do not return fds - good, but too simple 8) 1668 - return fds, and do not return them on read (old strategy, 1669 apparently wrong) 1670 - clone fds (I chose it for now, it is the most universal 1671 solution) 1672 1673 POSIX 1003.1g does not actually define this clearly 1674 at all. POSIX 1003.1g doesn't define a lot of things 1675 clearly however! 1676 1677 */ 1678 if (UNIXCB(skb).fp) 1679 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1680 } 1681 err = size; 1682 1683 scm_recv(sock, msg, siocb->scm, flags); 1684 1685 out_free: 1686 skb_free_datagram(sk,skb); 1687 out_unlock: 1688 mutex_unlock(&u->readlock); 1689 out: 1690 return err; 1691 } 1692 1693 /* 1694 * Sleep until data has arrive. But check for races.. 1695 */ 1696 1697 static long unix_stream_data_wait(struct sock * sk, long timeo) 1698 { 1699 DEFINE_WAIT(wait); 1700 1701 unix_state_lock(sk); 1702 1703 for (;;) { 1704 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); 1705 1706 if (!skb_queue_empty(&sk->sk_receive_queue) || 1707 sk->sk_err || 1708 (sk->sk_shutdown & RCV_SHUTDOWN) || 1709 signal_pending(current) || 1710 !timeo) 1711 break; 1712 1713 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1714 unix_state_unlock(sk); 1715 timeo = schedule_timeout(timeo); 1716 unix_state_lock(sk); 1717 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 1718 } 1719 1720 finish_wait(sk->sk_sleep, &wait); 1721 unix_state_unlock(sk); 1722 return timeo; 1723 } 1724 1725 1726 1727 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 1728 struct msghdr *msg, size_t size, 1729 int flags) 1730 { 1731 struct sock_iocb *siocb = kiocb_to_siocb(iocb); 1732 struct scm_cookie tmp_scm; 1733 struct sock *sk = sock->sk; 1734 struct unix_sock *u = unix_sk(sk); 1735 struct sockaddr_un *sunaddr=msg->msg_name; 1736 int copied = 0; 1737 int check_creds = 0; 1738 int target; 1739 int err = 0; 1740 long timeo; 1741 1742 err = -EINVAL; 1743 if (sk->sk_state != TCP_ESTABLISHED) 1744 goto out; 1745 1746 err = -EOPNOTSUPP; 1747 if (flags&MSG_OOB) 1748 goto out; 1749 1750 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 1751 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 1752 1753 msg->msg_namelen = 0; 1754 1755 /* Lock the socket to prevent queue disordering 1756 * while sleeps in memcpy_tomsg 1757 */ 1758 1759 if (!siocb->scm) { 1760 siocb->scm = &tmp_scm; 1761 memset(&tmp_scm, 0, sizeof(tmp_scm)); 1762 } 1763 1764 mutex_lock(&u->readlock); 1765 1766 do 1767 { 1768 int chunk; 1769 struct sk_buff *skb; 1770 1771 unix_state_lock(sk); 1772 skb = skb_dequeue(&sk->sk_receive_queue); 1773 if (skb==NULL) 1774 { 1775 if (copied >= target) 1776 goto unlock; 1777 1778 /* 1779 * POSIX 1003.1g mandates this order. 1780 */ 1781 1782 if ((err = sock_error(sk)) != 0) 1783 goto unlock; 1784 if (sk->sk_shutdown & RCV_SHUTDOWN) 1785 goto unlock; 1786 1787 unix_state_unlock(sk); 1788 err = -EAGAIN; 1789 if (!timeo) 1790 break; 1791 mutex_unlock(&u->readlock); 1792 1793 timeo = unix_stream_data_wait(sk, timeo); 1794 1795 if (signal_pending(current)) { 1796 err = sock_intr_errno(timeo); 1797 goto out; 1798 } 1799 mutex_lock(&u->readlock); 1800 continue; 1801 unlock: 1802 unix_state_unlock(sk); 1803 break; 1804 } 1805 unix_state_unlock(sk); 1806 1807 if (check_creds) { 1808 /* Never glue messages from different writers */ 1809 if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) { 1810 skb_queue_head(&sk->sk_receive_queue, skb); 1811 break; 1812 } 1813 } else { 1814 /* Copy credentials */ 1815 siocb->scm->creds = *UNIXCREDS(skb); 1816 check_creds = 1; 1817 } 1818 1819 /* Copy address just once */ 1820 if (sunaddr) 1821 { 1822 unix_copy_addr(msg, skb->sk); 1823 sunaddr = NULL; 1824 } 1825 1826 chunk = min_t(unsigned int, skb->len, size); 1827 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 1828 skb_queue_head(&sk->sk_receive_queue, skb); 1829 if (copied == 0) 1830 copied = -EFAULT; 1831 break; 1832 } 1833 copied += chunk; 1834 size -= chunk; 1835 1836 /* Mark read part of skb as used */ 1837 if (!(flags & MSG_PEEK)) 1838 { 1839 skb_pull(skb, chunk); 1840 1841 if (UNIXCB(skb).fp) 1842 unix_detach_fds(siocb->scm, skb); 1843 1844 /* put the skb back if we didn't use it up.. */ 1845 if (skb->len) 1846 { 1847 skb_queue_head(&sk->sk_receive_queue, skb); 1848 break; 1849 } 1850 1851 kfree_skb(skb); 1852 1853 if (siocb->scm->fp) 1854 break; 1855 } 1856 else 1857 { 1858 /* It is questionable, see note in unix_dgram_recvmsg. 1859 */ 1860 if (UNIXCB(skb).fp) 1861 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); 1862 1863 /* put message back and return */ 1864 skb_queue_head(&sk->sk_receive_queue, skb); 1865 break; 1866 } 1867 } while (size); 1868 1869 mutex_unlock(&u->readlock); 1870 scm_recv(sock, msg, siocb->scm, flags); 1871 out: 1872 return copied ? : err; 1873 } 1874 1875 static int unix_shutdown(struct socket *sock, int mode) 1876 { 1877 struct sock *sk = sock->sk; 1878 struct sock *other; 1879 1880 mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); 1881 1882 if (mode) { 1883 unix_state_lock(sk); 1884 sk->sk_shutdown |= mode; 1885 other=unix_peer(sk); 1886 if (other) 1887 sock_hold(other); 1888 unix_state_unlock(sk); 1889 sk->sk_state_change(sk); 1890 1891 if (other && 1892 (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { 1893 1894 int peer_mode = 0; 1895 1896 if (mode&RCV_SHUTDOWN) 1897 peer_mode |= SEND_SHUTDOWN; 1898 if (mode&SEND_SHUTDOWN) 1899 peer_mode |= RCV_SHUTDOWN; 1900 unix_state_lock(other); 1901 other->sk_shutdown |= peer_mode; 1902 unix_state_unlock(other); 1903 other->sk_state_change(other); 1904 read_lock(&other->sk_callback_lock); 1905 if (peer_mode == SHUTDOWN_MASK) 1906 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); 1907 else if (peer_mode & RCV_SHUTDOWN) 1908 sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); 1909 read_unlock(&other->sk_callback_lock); 1910 } 1911 if (other) 1912 sock_put(other); 1913 } 1914 return 0; 1915 } 1916 1917 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 1918 { 1919 struct sock *sk = sock->sk; 1920 long amount=0; 1921 int err; 1922 1923 switch(cmd) 1924 { 1925 case SIOCOUTQ: 1926 amount = atomic_read(&sk->sk_wmem_alloc); 1927 err = put_user(amount, (int __user *)arg); 1928 break; 1929 case SIOCINQ: 1930 { 1931 struct sk_buff *skb; 1932 1933 if (sk->sk_state == TCP_LISTEN) { 1934 err = -EINVAL; 1935 break; 1936 } 1937 1938 spin_lock(&sk->sk_receive_queue.lock); 1939 if (sk->sk_type == SOCK_STREAM || 1940 sk->sk_type == SOCK_SEQPACKET) { 1941 skb_queue_walk(&sk->sk_receive_queue, skb) 1942 amount += skb->len; 1943 } else { 1944 skb = skb_peek(&sk->sk_receive_queue); 1945 if (skb) 1946 amount=skb->len; 1947 } 1948 spin_unlock(&sk->sk_receive_queue.lock); 1949 err = put_user(amount, (int __user *)arg); 1950 break; 1951 } 1952 1953 default: 1954 err = -ENOIOCTLCMD; 1955 break; 1956 } 1957 return err; 1958 } 1959 1960 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) 1961 { 1962 struct sock *sk = sock->sk; 1963 unsigned int mask; 1964 1965 poll_wait(file, sk->sk_sleep, wait); 1966 mask = 0; 1967 1968 /* exceptional events? */ 1969 if (sk->sk_err) 1970 mask |= POLLERR; 1971 if (sk->sk_shutdown == SHUTDOWN_MASK) 1972 mask |= POLLHUP; 1973 if (sk->sk_shutdown & RCV_SHUTDOWN) 1974 mask |= POLLRDHUP; 1975 1976 /* readable? */ 1977 if (!skb_queue_empty(&sk->sk_receive_queue) || 1978 (sk->sk_shutdown & RCV_SHUTDOWN)) 1979 mask |= POLLIN | POLLRDNORM; 1980 1981 /* Connection-based need to check for termination and startup */ 1982 if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE) 1983 mask |= POLLHUP; 1984 1985 /* 1986 * we set writable also when the other side has shut down the 1987 * connection. This prevents stuck sockets. 1988 */ 1989 if (unix_writable(sk)) 1990 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 1991 1992 return mask; 1993 } 1994 1995 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 1996 poll_table *wait) 1997 { 1998 struct sock *sk = sock->sk, *other; 1999 unsigned int mask, writable; 2000 2001 poll_wait(file, sk->sk_sleep, wait); 2002 mask = 0; 2003 2004 /* exceptional events? */ 2005 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2006 mask |= POLLERR; 2007 if (sk->sk_shutdown & RCV_SHUTDOWN) 2008 mask |= POLLRDHUP; 2009 if (sk->sk_shutdown == SHUTDOWN_MASK) 2010 mask |= POLLHUP; 2011 2012 /* readable? */ 2013 if (!skb_queue_empty(&sk->sk_receive_queue) || 2014 (sk->sk_shutdown & RCV_SHUTDOWN)) 2015 mask |= POLLIN | POLLRDNORM; 2016 2017 /* Connection-based need to check for termination and startup */ 2018 if (sk->sk_type == SOCK_SEQPACKET) { 2019 if (sk->sk_state == TCP_CLOSE) 2020 mask |= POLLHUP; 2021 /* connection hasn't started yet? */ 2022 if (sk->sk_state == TCP_SYN_SENT) 2023 return mask; 2024 } 2025 2026 /* writable? */ 2027 writable = unix_writable(sk); 2028 if (writable) { 2029 other = unix_peer_get(sk); 2030 if (other) { 2031 if (unix_peer(other) != sk) { 2032 poll_wait(file, &unix_sk(other)->peer_wait, 2033 wait); 2034 if (unix_recvq_full(other)) 2035 writable = 0; 2036 } 2037 2038 sock_put(other); 2039 } 2040 } 2041 2042 if (writable) 2043 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2044 else 2045 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2046 2047 return mask; 2048 } 2049 2050 #ifdef CONFIG_PROC_FS 2051 static struct sock *first_unix_socket(int *i) 2052 { 2053 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2054 if (!hlist_empty(&unix_socket_table[*i])) 2055 return __sk_head(&unix_socket_table[*i]); 2056 } 2057 return NULL; 2058 } 2059 2060 static struct sock *next_unix_socket(int *i, struct sock *s) 2061 { 2062 struct sock *next = sk_next(s); 2063 /* More in this chain? */ 2064 if (next) 2065 return next; 2066 /* Look for next non-empty chain. */ 2067 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2068 if (!hlist_empty(&unix_socket_table[*i])) 2069 return __sk_head(&unix_socket_table[*i]); 2070 } 2071 return NULL; 2072 } 2073 2074 struct unix_iter_state { 2075 struct seq_net_private p; 2076 int i; 2077 }; 2078 static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2079 { 2080 struct unix_iter_state *iter = seq->private; 2081 loff_t off = 0; 2082 struct sock *s; 2083 2084 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2085 if (sock_net(s) != seq_file_net(seq)) 2086 continue; 2087 if (off == pos) 2088 return s; 2089 ++off; 2090 } 2091 return NULL; 2092 } 2093 2094 2095 static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2096 __acquires(unix_table_lock) 2097 { 2098 spin_lock(&unix_table_lock); 2099 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2100 } 2101 2102 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2103 { 2104 struct unix_iter_state *iter = seq->private; 2105 struct sock *sk = v; 2106 ++*pos; 2107 2108 if (v == SEQ_START_TOKEN) 2109 sk = first_unix_socket(&iter->i); 2110 else 2111 sk = next_unix_socket(&iter->i, sk); 2112 while (sk && (sock_net(sk) != seq_file_net(seq))) 2113 sk = next_unix_socket(&iter->i, sk); 2114 return sk; 2115 } 2116 2117 static void unix_seq_stop(struct seq_file *seq, void *v) 2118 __releases(unix_table_lock) 2119 { 2120 spin_unlock(&unix_table_lock); 2121 } 2122 2123 static int unix_seq_show(struct seq_file *seq, void *v) 2124 { 2125 2126 if (v == SEQ_START_TOKEN) 2127 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2128 "Inode Path\n"); 2129 else { 2130 struct sock *s = v; 2131 struct unix_sock *u = unix_sk(s); 2132 unix_state_lock(s); 2133 2134 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2135 s, 2136 atomic_read(&s->sk_refcnt), 2137 0, 2138 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2139 s->sk_type, 2140 s->sk_socket ? 2141 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2142 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2143 sock_i_ino(s)); 2144 2145 if (u->addr) { 2146 int i, len; 2147 seq_putc(seq, ' '); 2148 2149 i = 0; 2150 len = u->addr->len - sizeof(short); 2151 if (!UNIX_ABSTRACT(s)) 2152 len--; 2153 else { 2154 seq_putc(seq, '@'); 2155 i++; 2156 } 2157 for ( ; i < len; i++) 2158 seq_putc(seq, u->addr->name->sun_path[i]); 2159 } 2160 unix_state_unlock(s); 2161 seq_putc(seq, '\n'); 2162 } 2163 2164 return 0; 2165 } 2166 2167 static const struct seq_operations unix_seq_ops = { 2168 .start = unix_seq_start, 2169 .next = unix_seq_next, 2170 .stop = unix_seq_stop, 2171 .show = unix_seq_show, 2172 }; 2173 2174 2175 static int unix_seq_open(struct inode *inode, struct file *file) 2176 { 2177 return seq_open_net(inode, file, &unix_seq_ops, 2178 sizeof(struct unix_iter_state)); 2179 } 2180 2181 static const struct file_operations unix_seq_fops = { 2182 .owner = THIS_MODULE, 2183 .open = unix_seq_open, 2184 .read = seq_read, 2185 .llseek = seq_lseek, 2186 .release = seq_release_net, 2187 }; 2188 2189 #endif 2190 2191 static struct net_proto_family unix_family_ops = { 2192 .family = PF_UNIX, 2193 .create = unix_create, 2194 .owner = THIS_MODULE, 2195 }; 2196 2197 2198 static int unix_net_init(struct net *net) 2199 { 2200 int error = -ENOMEM; 2201 2202 net->unx.sysctl_max_dgram_qlen = 10; 2203 if (unix_sysctl_register(net)) 2204 goto out; 2205 2206 #ifdef CONFIG_PROC_FS 2207 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2208 unix_sysctl_unregister(net); 2209 goto out; 2210 } 2211 #endif 2212 error = 0; 2213 out: 2214 return 0; 2215 } 2216 2217 static void unix_net_exit(struct net *net) 2218 { 2219 unix_sysctl_unregister(net); 2220 proc_net_remove(net, "unix"); 2221 } 2222 2223 static struct pernet_operations unix_net_ops = { 2224 .init = unix_net_init, 2225 .exit = unix_net_exit, 2226 }; 2227 2228 static int __init af_unix_init(void) 2229 { 2230 int rc = -1; 2231 struct sk_buff *dummy_skb; 2232 2233 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2234 2235 rc = proto_register(&unix_proto, 1); 2236 if (rc != 0) { 2237 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2238 __func__); 2239 goto out; 2240 } 2241 2242 sock_register(&unix_family_ops); 2243 register_pernet_subsys(&unix_net_ops); 2244 out: 2245 return rc; 2246 } 2247 2248 static void __exit af_unix_exit(void) 2249 { 2250 sock_unregister(PF_UNIX); 2251 proto_unregister(&unix_proto); 2252 unregister_pernet_subsys(&unix_net_ops); 2253 } 2254 2255 /* Earlier than device_initcall() so that other drivers invoking 2256 request_module() don't end up in a loop when modprobe tries 2257 to use a UNIX socket. But later than subsys_initcall() because 2258 we depend on stuff initialised there */ 2259 fs_initcall(af_unix_init); 2260 module_exit(af_unix_exit); 2261 2262 MODULE_LICENSE("GPL"); 2263 MODULE_ALIAS_NETPROTO(PF_UNIX); 2264