1 /* 2 * NET4: Implementation of BSD Unix domain sockets. 3 * 4 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * Fixes: 12 * Linus Torvalds : Assorted bug cures. 13 * Niibe Yutaka : async I/O support. 14 * Carsten Paeth : PF_UNIX check, address fixes. 15 * Alan Cox : Limit size of allocated blocks. 16 * Alan Cox : Fixed the stupid socketpair bug. 17 * Alan Cox : BSD compatibility fine tuning. 18 * Alan Cox : Fixed a bug in connect when interrupted. 19 * Alan Cox : Sorted out a proper draft version of 20 * file descriptor passing hacked up from 21 * Mike Shaver's work. 22 * Marty Leisner : Fixes to fd passing 23 * Nick Nevin : recvmsg bugfix. 24 * Alan Cox : Started proper garbage collector 25 * Heiko EiBfeldt : Missing verify_area check 26 * Alan Cox : Started POSIXisms 27 * Andreas Schwab : Replace inode by dentry for proper 28 * reference counting 29 * Kirk Petersen : Made this a module 30 * Christoph Rohland : Elegant non-blocking accept/connect algorithm. 31 * Lots of bug fixes. 32 * Alexey Kuznetosv : Repaired (I hope) bugs introduces 33 * by above two patches. 34 * Andrea Arcangeli : If possible we block in connect(2) 35 * if the max backlog of the listen socket 36 * is been reached. This won't break 37 * old apps and it will avoid huge amount 38 * of socks hashed (this for unix_gc() 39 * performances reasons). 40 * Security fix that limits the max 41 * number of socks to 2*max_files and 42 * the number of skb queueable in the 43 * dgram receiver. 44 * Artur Skawina : Hash function optimizations 45 * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) 46 * Malcolm Beattie : Set peercred for socketpair 47 * Michal Ostrowski : Module initialization cleanup. 48 * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, 49 * the core infrastructure is doing that 50 * for all net proto families now (2.5.69+) 51 * 52 * 53 * Known differences from reference BSD that was tested: 54 * 55 * [TO FIX] 56 * ECONNREFUSED is not returned from one end of a connected() socket to the 57 * other the moment one end closes. 58 * fstat() doesn't return st_dev=0, and give the blksize as high water mark 59 * and a fake inode identifier (nor the BSD first socket fstat twice bug). 60 * [NOT TO FIX] 61 * accept() returns a path name even if the connecting socket has closed 62 * in the meantime (BSD loses the path and gives up). 63 * accept() returns 0 length path for an unbound connector. BSD returns 16 64 * and a null first byte in the path (but not for gethost/peername - BSD bug ??) 65 * socketpair(...SOCK_RAW..) doesn't panic the kernel. 66 * BSD af_unix apparently has connect forgetting to block properly. 67 * (need to check this with the POSIX spec in detail) 68 * 69 * Differences from 2.0.0-11-... (ANK) 70 * Bug fixes and improvements. 71 * - client shutdown killed server socket. 72 * - removed all useless cli/sti pairs. 73 * 74 * Semantic changes/extensions. 75 * - generic control message passing. 76 * - SCM_CREDENTIALS control message. 77 * - "Abstract" (not FS based) socket bindings. 78 * Abstract names are sequences of bytes (not zero terminated) 79 * started by 0, so that this name space does not intersect 80 * with BSD names. 81 */ 82 83 #include <linux/module.h> 84 #include <linux/kernel.h> 85 #include <linux/signal.h> 86 #include <linux/sched.h> 87 #include <linux/errno.h> 88 #include <linux/string.h> 89 #include <linux/stat.h> 90 #include <linux/dcache.h> 91 #include <linux/namei.h> 92 #include <linux/socket.h> 93 #include <linux/un.h> 94 #include <linux/fcntl.h> 95 #include <linux/termios.h> 96 #include <linux/sockios.h> 97 #include <linux/net.h> 98 #include <linux/in.h> 99 #include <linux/fs.h> 100 #include <linux/slab.h> 101 #include <asm/uaccess.h> 102 #include <linux/skbuff.h> 103 #include <linux/netdevice.h> 104 #include <net/net_namespace.h> 105 #include <net/sock.h> 106 #include <net/tcp_states.h> 107 #include <net/af_unix.h> 108 #include <linux/proc_fs.h> 109 #include <linux/seq_file.h> 110 #include <net/scm.h> 111 #include <linux/init.h> 112 #include <linux/poll.h> 113 #include <linux/rtnetlink.h> 114 #include <linux/mount.h> 115 #include <net/checksum.h> 116 #include <linux/security.h> 117 118 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 path path; 715 int err = 0; 716 717 if (sunname->sun_path[0]) { 718 struct inode *inode; 719 err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); 720 if (err) 721 goto fail; 722 inode = path.dentry->d_inode; 723 err = inode_permission(inode, MAY_WRITE); 724 if (err) 725 goto put_fail; 726 727 err = -ECONNREFUSED; 728 if (!S_ISSOCK(inode->i_mode)) 729 goto put_fail; 730 u = unix_find_socket_byinode(net, inode); 731 if (!u) 732 goto put_fail; 733 734 if (u->sk_type == type) 735 touch_atime(path.mnt, path.dentry); 736 737 path_put(&path); 738 739 err=-EPROTOTYPE; 740 if (u->sk_type != type) { 741 sock_put(u); 742 goto fail; 743 } 744 } else { 745 err = -ECONNREFUSED; 746 u=unix_find_socket_byname(net, sunname, len, type, hash); 747 if (u) { 748 struct dentry *dentry; 749 dentry = unix_sk(u)->dentry; 750 if (dentry) 751 touch_atime(unix_sk(u)->mnt, dentry); 752 } else 753 goto fail; 754 } 755 return u; 756 757 put_fail: 758 path_put(&path); 759 fail: 760 *error=err; 761 return NULL; 762 } 763 764 765 static 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); 864 865 out_unlock: 866 spin_unlock(&unix_table_lock); 867 out_up: 868 mutex_unlock(&u->readlock); 869 out: 870 return err; 871 872 out_mknod_dput: 873 dput(dentry); 874 out_mknod_unlock: 875 mutex_unlock(&nd.path.dentry->d_inode->i_mutex); 876 path_put(&nd.path); 877 out_mknod_parent: 878 if (err==-EEXIST) 879 err=-EADDRINUSE; 880 unix_release_addr(addr); 881 goto out_up; 882 } 883 884 static 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 } 898 899 static 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 } 908 909 static 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; 928 929 restart: 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; 975 976 out_unlock: 977 unix_state_double_unlock(sk, other); 978 sock_put(other); 979 out: 980 return err; 981 } 982 983 static 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 1004 static 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 1047 restart: 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 1166 out_unlock: 1167 if (other) 1168 unix_state_unlock(other); 1169 1170 out: 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 1180 static 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 1202 static 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 1240 out: 1241 return err; 1242 } 1243 1244 1245 static 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); 1277 out: 1278 return err; 1279 } 1280 1281 static 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 1293 static 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 1305 static 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 1319 static 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 1382 restart: 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 1458 out_unlock: 1459 unix_state_unlock(other); 1460 out_free: 1461 kfree_skb(skb); 1462 out: 1463 if (other) 1464 sock_put(other); 1465 scm_destroy(siocb->scm); 1466 return err; 1467 } 1468 1469 1470 static 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 1566 pipe_err_free: 1567 unix_state_unlock(other); 1568 kfree_skb(skb); 1569 pipe_err: 1570 if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL)) 1571 send_sig(SIGPIPE,current,0); 1572 err = -EPIPE; 1573 out_err: 1574 scm_destroy(siocb->scm); 1575 siocb->scm = NULL; 1576 return sent ? : err; 1577 } 1578 1579 static 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 1598 static 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 1609 static 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 1687 out_free: 1688 skb_free_datagram(sk,skb); 1689 out_unlock: 1690 mutex_unlock(&u->readlock); 1691 out: 1692 return err; 1693 } 1694 1695 /* 1696 * Sleep until data has arrive. But check for races.. 1697 */ 1698 1699 static 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 1729 static 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); 1873 out: 1874 return copied ? : err; 1875 } 1876 1877 static 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 1919 static 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 1962 static 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 1997 static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, 1998 poll_table *wait) 1999 { 2000 struct sock *sk = sock->sk, *other; 2001 unsigned int mask, writable; 2002 2003 poll_wait(file, sk->sk_sleep, wait); 2004 mask = 0; 2005 2006 /* exceptional events? */ 2007 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 2008 mask |= POLLERR; 2009 if (sk->sk_shutdown & RCV_SHUTDOWN) 2010 mask |= POLLRDHUP; 2011 if (sk->sk_shutdown == SHUTDOWN_MASK) 2012 mask |= POLLHUP; 2013 2014 /* readable? */ 2015 if (!skb_queue_empty(&sk->sk_receive_queue) || 2016 (sk->sk_shutdown & RCV_SHUTDOWN)) 2017 mask |= POLLIN | POLLRDNORM; 2018 2019 /* Connection-based need to check for termination and startup */ 2020 if (sk->sk_type == SOCK_SEQPACKET) { 2021 if (sk->sk_state == TCP_CLOSE) 2022 mask |= POLLHUP; 2023 /* connection hasn't started yet? */ 2024 if (sk->sk_state == TCP_SYN_SENT) 2025 return mask; 2026 } 2027 2028 /* writable? */ 2029 writable = unix_writable(sk); 2030 if (writable) { 2031 other = unix_peer_get(sk); 2032 if (other) { 2033 if (unix_peer(other) != sk) { 2034 poll_wait(file, &unix_sk(other)->peer_wait, 2035 wait); 2036 if (unix_recvq_full(other)) 2037 writable = 0; 2038 } 2039 2040 sock_put(other); 2041 } 2042 } 2043 2044 if (writable) 2045 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 2046 else 2047 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 2048 2049 return mask; 2050 } 2051 2052 #ifdef CONFIG_PROC_FS 2053 static struct sock *first_unix_socket(int *i) 2054 { 2055 for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { 2056 if (!hlist_empty(&unix_socket_table[*i])) 2057 return __sk_head(&unix_socket_table[*i]); 2058 } 2059 return NULL; 2060 } 2061 2062 static struct sock *next_unix_socket(int *i, struct sock *s) 2063 { 2064 struct sock *next = sk_next(s); 2065 /* More in this chain? */ 2066 if (next) 2067 return next; 2068 /* Look for next non-empty chain. */ 2069 for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { 2070 if (!hlist_empty(&unix_socket_table[*i])) 2071 return __sk_head(&unix_socket_table[*i]); 2072 } 2073 return NULL; 2074 } 2075 2076 struct unix_iter_state { 2077 struct seq_net_private p; 2078 int i; 2079 }; 2080 static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) 2081 { 2082 struct unix_iter_state *iter = seq->private; 2083 loff_t off = 0; 2084 struct sock *s; 2085 2086 for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { 2087 if (sock_net(s) != seq_file_net(seq)) 2088 continue; 2089 if (off == pos) 2090 return s; 2091 ++off; 2092 } 2093 return NULL; 2094 } 2095 2096 2097 static void *unix_seq_start(struct seq_file *seq, loff_t *pos) 2098 __acquires(unix_table_lock) 2099 { 2100 spin_lock(&unix_table_lock); 2101 return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; 2102 } 2103 2104 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2105 { 2106 struct unix_iter_state *iter = seq->private; 2107 struct sock *sk = v; 2108 ++*pos; 2109 2110 if (v == SEQ_START_TOKEN) 2111 sk = first_unix_socket(&iter->i); 2112 else 2113 sk = next_unix_socket(&iter->i, sk); 2114 while (sk && (sock_net(sk) != seq_file_net(seq))) 2115 sk = next_unix_socket(&iter->i, sk); 2116 return sk; 2117 } 2118 2119 static void unix_seq_stop(struct seq_file *seq, void *v) 2120 __releases(unix_table_lock) 2121 { 2122 spin_unlock(&unix_table_lock); 2123 } 2124 2125 static int unix_seq_show(struct seq_file *seq, void *v) 2126 { 2127 2128 if (v == SEQ_START_TOKEN) 2129 seq_puts(seq, "Num RefCount Protocol Flags Type St " 2130 "Inode Path\n"); 2131 else { 2132 struct sock *s = v; 2133 struct unix_sock *u = unix_sk(s); 2134 unix_state_lock(s); 2135 2136 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu", 2137 s, 2138 atomic_read(&s->sk_refcnt), 2139 0, 2140 s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, 2141 s->sk_type, 2142 s->sk_socket ? 2143 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : 2144 (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), 2145 sock_i_ino(s)); 2146 2147 if (u->addr) { 2148 int i, len; 2149 seq_putc(seq, ' '); 2150 2151 i = 0; 2152 len = u->addr->len - sizeof(short); 2153 if (!UNIX_ABSTRACT(s)) 2154 len--; 2155 else { 2156 seq_putc(seq, '@'); 2157 i++; 2158 } 2159 for ( ; i < len; i++) 2160 seq_putc(seq, u->addr->name->sun_path[i]); 2161 } 2162 unix_state_unlock(s); 2163 seq_putc(seq, '\n'); 2164 } 2165 2166 return 0; 2167 } 2168 2169 static const struct seq_operations unix_seq_ops = { 2170 .start = unix_seq_start, 2171 .next = unix_seq_next, 2172 .stop = unix_seq_stop, 2173 .show = unix_seq_show, 2174 }; 2175 2176 2177 static int unix_seq_open(struct inode *inode, struct file *file) 2178 { 2179 return seq_open_net(inode, file, &unix_seq_ops, 2180 sizeof(struct unix_iter_state)); 2181 } 2182 2183 static const struct file_operations unix_seq_fops = { 2184 .owner = THIS_MODULE, 2185 .open = unix_seq_open, 2186 .read = seq_read, 2187 .llseek = seq_lseek, 2188 .release = seq_release_net, 2189 }; 2190 2191 #endif 2192 2193 static struct net_proto_family unix_family_ops = { 2194 .family = PF_UNIX, 2195 .create = unix_create, 2196 .owner = THIS_MODULE, 2197 }; 2198 2199 2200 static int unix_net_init(struct net *net) 2201 { 2202 int error = -ENOMEM; 2203 2204 net->unx.sysctl_max_dgram_qlen = 10; 2205 if (unix_sysctl_register(net)) 2206 goto out; 2207 2208 #ifdef CONFIG_PROC_FS 2209 if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { 2210 unix_sysctl_unregister(net); 2211 goto out; 2212 } 2213 #endif 2214 error = 0; 2215 out: 2216 return error; 2217 } 2218 2219 static void unix_net_exit(struct net *net) 2220 { 2221 unix_sysctl_unregister(net); 2222 proc_net_remove(net, "unix"); 2223 } 2224 2225 static struct pernet_operations unix_net_ops = { 2226 .init = unix_net_init, 2227 .exit = unix_net_exit, 2228 }; 2229 2230 static int __init af_unix_init(void) 2231 { 2232 int rc = -1; 2233 struct sk_buff *dummy_skb; 2234 2235 BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); 2236 2237 rc = proto_register(&unix_proto, 1); 2238 if (rc != 0) { 2239 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", 2240 __func__); 2241 goto out; 2242 } 2243 2244 sock_register(&unix_family_ops); 2245 register_pernet_subsys(&unix_net_ops); 2246 out: 2247 return rc; 2248 } 2249 2250 static void __exit af_unix_exit(void) 2251 { 2252 sock_unregister(PF_UNIX); 2253 proto_unregister(&unix_proto); 2254 unregister_pernet_subsys(&unix_net_ops); 2255 } 2256 2257 /* Earlier than device_initcall() so that other drivers invoking 2258 request_module() don't end up in a loop when modprobe tries 2259 to use a UNIX socket. But later than subsys_initcall() because 2260 we depend on stuff initialised there */ 2261 fs_initcall(af_unix_init); 2262 module_exit(af_unix_exit); 2263 2264 MODULE_LICENSE("GPL"); 2265 MODULE_ALIAS_NETPROTO(PF_UNIX); 2266