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   1 /*
   2  * NET4:        Implementation of BSD Unix domain sockets.
   3  *
   4  * Authors:     Alan Cox, <alan.cox@linux.org>
   5  *
   6  *              This program is free software; you can redistribute it and/or
   7  *              modify it under the terms of the GNU General Public License
   8  *              as published by the Free Software Foundation; either version
   9  *              2 of the License, or (at your option) any later version.
  10  *
  11  * Version:     $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $
  12  *
  13  * Fixes:
  14  *              Linus Torvalds  :       Assorted bug cures.
  15  *              Niibe Yutaka    :       async I/O support.
  16  *              Carsten Paeth   :       PF_UNIX check, address fixes.
  17  *              Alan Cox        :       Limit size of allocated blocks.
  18  *              Alan Cox        :       Fixed the stupid socketpair bug.
  19  *              Alan Cox        :       BSD compatibility fine tuning.
  20  *              Alan Cox        :       Fixed a bug in connect when interrupted.
  21  *              Alan Cox        :       Sorted out a proper draft version of
  22  *                                      file descriptor passing hacked up from
  23  *                                      Mike Shaver's work.
  24  *              Marty Leisner   :       Fixes to fd passing
  25  *              Nick Nevin      :       recvmsg bugfix.
  26  *              Alan Cox        :       Started proper garbage collector
  27  *              Heiko EiBfeldt  :       Missing verify_area check
  28  *              Alan Cox        :       Started POSIXisms
  29  *              Andreas Schwab  :       Replace inode by dentry for proper
  30  *                                      reference counting
  31  *              Kirk Petersen   :       Made this a module
  32  *          Christoph Rohland   :       Elegant non-blocking accept/connect algorithm.
  33  *                                      Lots of bug fixes.
  34  *           Alexey Kuznetosv   :       Repaired (I hope) bugs introduces
  35  *                                      by above two patches.
  36  *           Andrea Arcangeli   :       If possible we block in connect(2)
  37  *                                      if the max backlog of the listen socket
  38  *                                      is been reached. This won't break
  39  *                                      old apps and it will avoid huge amount
  40  *                                      of socks hashed (this for unix_gc()
  41  *                                      performances reasons).
  42  *                                      Security fix that limits the max
  43  *                                      number of socks to 2*max_files and
  44  *                                      the number of skb queueable in the
  45  *                                      dgram receiver.
  46  *              Artur Skawina   :       Hash function optimizations
  47  *           Alexey Kuznetsov   :       Full scale SMP. Lot of bugs are introduced 8)
  48  *            Malcolm Beattie   :       Set peercred for socketpair
  49  *           Michal Ostrowski   :       Module initialization cleanup.
  50  *           Arnaldo C. Melo    :       Remove MOD_{INC,DEC}_USE_COUNT,
  51  *                                      the core infrastructure is doing that
  52  *                                      for all net proto families now (2.5.69+)
  53  *
  54  *
  55  * Known differences from reference BSD that was tested:
  56  *
  57  *      [TO FIX]
  58  *      ECONNREFUSED is not returned from one end of a connected() socket to the
  59  *              other the moment one end closes.
  60  *      fstat() doesn't return st_dev=0, and give the blksize as high water mark
  61  *              and a fake inode identifier (nor the BSD first socket fstat twice bug).
  62  *      [NOT TO FIX]
  63  *      accept() returns a path name even if the connecting socket has closed
  64  *              in the meantime (BSD loses the path and gives up).
  65  *      accept() returns 0 length path for an unbound connector. BSD returns 16
  66  *              and a null first byte in the path (but not for gethost/peername - BSD bug ??)
  67  *      socketpair(...SOCK_RAW..) doesn't panic the kernel.
  68  *      BSD af_unix apparently has connect forgetting to block properly.
  69  *              (need to check this with the POSIX spec in detail)
  70  *
  71  * Differences from 2.0.0-11-... (ANK)
  72  *      Bug fixes and improvements.
  73  *              - client shutdown killed server socket.
  74  *              - removed all useless cli/sti pairs.
  75  *
  76  *      Semantic changes/extensions.
  77  *              - generic control message passing.
  78  *              - SCM_CREDENTIALS control message.
  79  *              - "Abstract" (not FS based) socket bindings.
  80  *                Abstract names are sequences of bytes (not zero terminated)
  81  *                started by 0, so that this name space does not intersect
  82  *                with BSD names.
  83  */
  84
  85 #include <linux/module.h>
  86 #include <linux/kernel.h>
  87 #include <linux/signal.h>
  88 #include <linux/sched.h>
  89 #include <linux/errno.h>
  90 #include <linux/string.h>
  91 #include <linux/stat.h>
  92 #include <linux/dcache.h>
  93 #include <linux/namei.h>
  94 #include <linux/socket.h>
  95 #include <linux/un.h>
  96 #include <linux/fcntl.h>
  97 #include <linux/termios.h>
  98 #include <linux/sockios.h>
  99 #include <linux/net.h>
 100 #include <linux/in.h>
 101 #include <linux/fs.h>
 102 #include <linux/slab.h>
 103 #include <asm/uaccess.h>
 104 #include <linux/skbuff.h>
 105 #include <linux/netdevice.h>
 106 #include <net/net_namespace.h>
 107 #include <net/sock.h>
 108 #include <net/tcp_states.h>
 109 #include <net/af_unix.h>
 110 #include <linux/proc_fs.h>
 111 #include <linux/seq_file.h>
 112 #include <net/scm.h>
 113 #include <linux/init.h>
 114 #include <linux/poll.h>
 115 #include <linux/rtnetlink.h>
 116 #include <linux/mount.h>
 117 #include <net/checksum.h>
 118 #include <linux/security.h>
 119
 120 int sysctl_unix_max_dgram_qlen __read_mostly = 10;
 121
 122 static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
 123 static DEFINE_SPINLOCK(unix_table_lock);
 124 static atomic_t unix_nr_socks = ATOMIC_INIT(0);
 125
 126 #define unix_sockets_unbound    (&unix_socket_table[UNIX_HASH_SIZE])
 127
 128 #define UNIX_ABSTRACT(sk)       (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
 129
 130 static struct sock *first_unix_socket(int *i)
 131 {
 132         for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
 133                 if (!hlist_empty(&unix_socket_table[*i]))
 134                         return __sk_head(&unix_socket_table[*i]);
 135         }
 136         return NULL;
 137 }
 138
 139 static struct sock *next_unix_socket(int *i, struct sock *s)
 140 {
 141         struct sock *next = sk_next(s);
 142         /* More in this chain? */
 143         if (next)
 144                 return next;
 145         /* Look for next non-empty chain. */
 146         for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
 147                 if (!hlist_empty(&unix_socket_table[*i]))
 148                         return __sk_head(&unix_socket_table[*i]);
 149         }
 150         return NULL;
 151 }
 152
 153 #define forall_unix_sockets(i, s) \
 154         for (s = first_unix_socket(&(i)); s; s = next_unix_socket(&(i),(s)))
 155
 156 #ifdef CONFIG_SECURITY_NETWORK
 157 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 158 {
 159         memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
 160 }
 161
 162 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 163 {
 164         scm->secid = *UNIXSID(skb);
 165 }
 166 #else
 167 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 168 { }
 169
 170 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 171 { }
 172 #endif /* CONFIG_SECURITY_NETWORK */
 173
 174 /*
 175  *  SMP locking strategy:
 176  *    hash table is protected with spinlock unix_table_lock
 177  *    each socket state is protected by separate rwlock.
 178  */
 179
 180 static inline unsigned unix_hash_fold(__wsum n)
 181 {
 182         unsigned hash = (__force unsigned)n;
 183         hash ^= hash>>16;
 184         hash ^= hash>>8;
 185         return hash&(UNIX_HASH_SIZE-1);
 186 }
 187
 188 #define unix_peer(sk) (unix_sk(sk)->peer)
 189
 190 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
 191 {
 192         return unix_peer(osk) == sk;
 193 }
 194
 195 static inline int unix_may_send(struct sock *sk, struct sock *osk)
 196 {
 197         return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
 198 }
 199
 200 static struct sock *unix_peer_get(struct sock *s)
 201 {
 202         struct sock *peer;
 203
 204         unix_state_lock(s);
 205         peer = unix_peer(s);
 206         if (peer)
 207                 sock_hold(peer);
 208         unix_state_unlock(s);
 209         return peer;
 210 }
 211
 212 static inline void unix_release_addr(struct unix_address *addr)
 213 {
 214         if (atomic_dec_and_test(&addr->refcnt))
 215                 kfree(addr);
 216 }
 217
 218 /*
 219  *      Check unix socket name:
 220  *              - should be not zero length.
 221  *              - if started by not zero, should be NULL terminated (FS object)
 222  *              - if started by zero, it is abstract name.
 223  */
 224
 225 static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
 226 {
 227         if (len <= sizeof(short) || len > sizeof(*sunaddr))
 228                 return -EINVAL;
 229         if (!sunaddr || sunaddr->sun_family != AF_UNIX)
 230                 return -EINVAL;
 231         if (sunaddr->sun_path[0]) {
 232                 /*
 233                  * This may look like an off by one error but it is a bit more
 234                  * subtle. 108 is the longest valid AF_UNIX path for a binding.
 235                  * sun_path[108] doesnt as such exist.  However in kernel space
 236                  * we are guaranteed that it is a valid memory location in our
 237                  * kernel address buffer.
 238                  */
 239                 ((char *)sunaddr)[len]=0;
 240                 len = strlen(sunaddr->sun_path)+1+sizeof(short);
 241                 return len;
 242         }
 243
 244         *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
 245         return len;
 246 }
 247
 248 static void __unix_remove_socket(struct sock *sk)
 249 {
 250         sk_del_node_init(sk);
 251 }
 252
 253 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
 254 {
 255         BUG_TRAP(sk_unhashed(sk));
 256         sk_add_node(sk, list);
 257 }
 258
 259 static inline void unix_remove_socket(struct sock *sk)
 260 {
 261         spin_lock(&unix_table_lock);
 262         __unix_remove_socket(sk);
 263         spin_unlock(&unix_table_lock);
 264 }
 265
 266 static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
 267 {
 268         spin_lock(&unix_table_lock);
 269         __unix_insert_socket(list, sk);
 270         spin_unlock(&unix_table_lock);
 271 }
 272
 273 static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname,
 274                                               int len, int type, unsigned hash)
 275 {
 276         struct sock *s;
 277         struct hlist_node *node;
 278
 279         sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
 280                 struct unix_sock *u = unix_sk(s);
 281
 282                 if (u->addr->len == len &&
 283                     !memcmp(u->addr->name, sunname, len))
 284                         goto found;
 285         }
 286         s = NULL;
 287 found:
 288         return s;
 289 }
 290
 291 static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname,
 292                                                    int len, int type,
 293                                                    unsigned hash)
 294 {
 295         struct sock *s;
 296
 297         spin_lock(&unix_table_lock);
 298         s = __unix_find_socket_byname(sunname, len, type, hash);
 299         if (s)
 300                 sock_hold(s);
 301         spin_unlock(&unix_table_lock);
 302         return s;
 303 }
 304
 305 static struct sock *unix_find_socket_byinode(struct inode *i)
 306 {
 307         struct sock *s;
 308         struct hlist_node *node;
 309
 310         spin_lock(&unix_table_lock);
 311         sk_for_each(s, node,
 312                     &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
 313                 struct dentry *dentry = unix_sk(s)->dentry;
 314
 315                 if(dentry && dentry->d_inode == i)
 316                 {
 317                         sock_hold(s);
 318                         goto found;
 319                 }
 320         }
 321         s = NULL;
 322 found:
 323         spin_unlock(&unix_table_lock);
 324         return s;
 325 }
 326
 327 static inline int unix_writable(struct sock *sk)
 328 {
 329         return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
 330 }
 331
 332 static void unix_write_space(struct sock *sk)
 333 {
 334         read_lock(&sk->sk_callback_lock);
 335         if (unix_writable(sk)) {
 336                 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 337                         wake_up_interruptible_sync(sk->sk_sleep);
 338                 sk_wake_async(sk, 2, POLL_OUT);
 339         }
 340         read_unlock(&sk->sk_callback_lock);
 341 }
 342
 343 /* When dgram socket disconnects (or changes its peer), we clear its receive
 344  * queue of packets arrived from previous peer. First, it allows to do
 345  * flow control based only on wmem_alloc; second, sk connected to peer
 346  * may receive messages only from that peer. */
 347 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
 348 {
 349         if (!skb_queue_empty(&sk->sk_receive_queue)) {
 350                 skb_queue_purge(&sk->sk_receive_queue);
 351                 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
 352
 353                 /* If one link of bidirectional dgram pipe is disconnected,
 354                  * we signal error. Messages are lost. Do not make this,
 355                  * when peer was not connected to us.
 356                  */
 357                 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
 358                         other->sk_err = ECONNRESET;
 359                         other->sk_error_report(other);
 360                 }
 361         }
 362 }
 363
 364 static void unix_sock_destructor(struct sock *sk)
 365 {
 366         struct unix_sock *u = unix_sk(sk);
 367
 368         skb_queue_purge(&sk->sk_receive_queue);
 369
 370         BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
 371         BUG_TRAP(sk_unhashed(sk));
 372         BUG_TRAP(!sk->sk_socket);
 373         if (!sock_flag(sk, SOCK_DEAD)) {
 374                 printk("Attempt to release alive unix socket: %p\n", sk);
 375                 return;
 376         }
 377
 378         if (u->addr)
 379                 unix_release_addr(u->addr);
 380
 381         atomic_dec(&unix_nr_socks);
 382 #ifdef UNIX_REFCNT_DEBUG
 383         printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
 384 #endif
 385 }
 386
 387 static int unix_release_sock (struct sock *sk, int embrion)
 388 {
 389         struct unix_sock *u = unix_sk(sk);
 390         struct dentry *dentry;
 391         struct vfsmount *mnt;
 392         struct sock *skpair;
 393         struct sk_buff *skb;
 394         int state;
 395
 396         unix_remove_socket(sk);
 397
 398         /* Clear state */
 399         unix_state_lock(sk);
 400         sock_orphan(sk);
 401         sk->sk_shutdown = SHUTDOWN_MASK;
 402         dentry       = u->dentry;
 403         u->dentry    = NULL;
 404         mnt          = u->mnt;
 405         u->mnt       = NULL;
 406         state = sk->sk_state;
 407         sk->sk_state = TCP_CLOSE;
 408         unix_state_unlock(sk);
 409
 410         wake_up_interruptible_all(&u->peer_wait);
 411
 412         skpair=unix_peer(sk);
 413
 414         if (skpair!=NULL) {
 415                 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
 416                         unix_state_lock(skpair);
 417                         /* No more writes */
 418                         skpair->sk_shutdown = SHUTDOWN_MASK;
 419                         if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
 420                                 skpair->sk_err = ECONNRESET;
 421                         unix_state_unlock(skpair);
 422                         skpair->sk_state_change(skpair);
 423                         read_lock(&skpair->sk_callback_lock);
 424                         sk_wake_async(skpair,1,POLL_HUP);
 425                         read_unlock(&skpair->sk_callback_lock);
 426                 }
 427                 sock_put(skpair); /* It may now die */
 428                 unix_peer(sk) = NULL;
 429         }
 430
 431         /* Try to flush out this socket. Throw out buffers at least */
 432
 433         while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 434                 if (state==TCP_LISTEN)
 435                         unix_release_sock(skb->sk, 1);
 436                 /* passed fds are erased in the kfree_skb hook        */
 437                 kfree_skb(skb);
 438         }
 439
 440         if (dentry) {
 441                 dput(dentry);
 442                 mntput(mnt);
 443         }
 444
 445         sock_put(sk);
 446
 447         /* ---- Socket is dead now and most probably destroyed ---- */
 448
 449         /*
 450          * Fixme: BSD difference: In BSD all sockets connected to use get
 451          *        ECONNRESET and we die on the spot. In Linux we behave
 452          *        like files and pipes do and wait for the last
 453          *        dereference.
 454          *
 455          * Can't we simply set sock->err?
 456          *
 457          *        What the above comment does talk about? --ANK(980817)
 458          */
 459
 460         if (unix_tot_inflight)
 461                 unix_gc();              /* Garbage collect fds */
 462
 463         return 0;
 464 }
 465
 466 static int unix_listen(struct socket *sock, int backlog)
 467 {
 468         int err;
 469         struct sock *sk = sock->sk;
 470         struct unix_sock *u = unix_sk(sk);
 471
 472         err = -EOPNOTSUPP;
 473         if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
 474                 goto out;                       /* Only stream/seqpacket sockets accept */
 475         err = -EINVAL;
 476         if (!u->addr)
 477                 goto out;                       /* No listens on an unbound socket */
 478         unix_state_lock(sk);
 479         if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
 480                 goto out_unlock;
 481         if (backlog > sk->sk_max_ack_backlog)
 482                 wake_up_interruptible_all(&u->peer_wait);
 483         sk->sk_max_ack_backlog  = backlog;
 484         sk->sk_state            = TCP_LISTEN;
 485         /* set credentials so connect can copy them */
 486         sk->sk_peercred.pid     = task_tgid_vnr(current);
 487         sk->sk_peercred.uid     = current->euid;
 488         sk->sk_peercred.gid     = current->egid;
 489         err = 0;
 490
 491 out_unlock:
 492         unix_state_unlock(sk);
 493 out:
 494         return err;
 495 }
 496
 497 static int unix_release(struct socket *);
 498 static int unix_bind(struct socket *, struct sockaddr *, int);
 499 static int unix_stream_connect(struct socket *, struct sockaddr *,
 500                                int addr_len, int flags);
 501 static int unix_socketpair(struct socket *, struct socket *);
 502 static int unix_accept(struct socket *, struct socket *, int);
 503 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
 504 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
 505 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
 506 static int unix_shutdown(struct socket *, int);
 507 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
 508                                struct msghdr *, size_t);
 509 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
 510                                struct msghdr *, size_t, int);
 511 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
 512                               struct msghdr *, size_t);
 513 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
 514                               struct msghdr *, size_t, int);
 515 static int unix_dgram_connect(struct socket *, struct sockaddr *,
 516                               int, int);
 517 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
 518                                   struct msghdr *, size_t);
 519
 520 static const struct proto_ops unix_stream_ops = {
 521         .family =       PF_UNIX,
 522         .owner =        THIS_MODULE,
 523         .release =      unix_release,
 524         .bind =         unix_bind,
 525         .connect =      unix_stream_connect,
 526         .socketpair =   unix_socketpair,
 527         .accept =       unix_accept,
 528         .getname =      unix_getname,
 529         .poll =         unix_poll,
 530         .ioctl =        unix_ioctl,
 531         .listen =       unix_listen,
 532         .shutdown =     unix_shutdown,
 533         .setsockopt =   sock_no_setsockopt,
 534         .getsockopt =   sock_no_getsockopt,
 535         .sendmsg =      unix_stream_sendmsg,
 536         .recvmsg =      unix_stream_recvmsg,
 537         .mmap =         sock_no_mmap,
 538         .sendpage =     sock_no_sendpage,
 539 };
 540
 541 static const struct proto_ops unix_dgram_ops = {
 542         .family =       PF_UNIX,
 543         .owner =        THIS_MODULE,
 544         .release =      unix_release,
 545         .bind =         unix_bind,
 546         .connect =      unix_dgram_connect,
 547         .socketpair =   unix_socketpair,
 548         .accept =       sock_no_accept,
 549         .getname =      unix_getname,
 550         .poll =         datagram_poll,
 551         .ioctl =        unix_ioctl,
 552         .listen =       sock_no_listen,
 553         .shutdown =     unix_shutdown,
 554         .setsockopt =   sock_no_setsockopt,
 555         .getsockopt =   sock_no_getsockopt,
 556         .sendmsg =      unix_dgram_sendmsg,
 557         .recvmsg =      unix_dgram_recvmsg,
 558         .mmap =         sock_no_mmap,
 559         .sendpage =     sock_no_sendpage,
 560 };
 561
 562 static const struct proto_ops unix_seqpacket_ops = {
 563         .family =       PF_UNIX,
 564         .owner =        THIS_MODULE,
 565         .release =      unix_release,
 566         .bind =         unix_bind,
 567         .connect =      unix_stream_connect,
 568         .socketpair =   unix_socketpair,
 569         .accept =       unix_accept,
 570         .getname =      unix_getname,
 571         .poll =         datagram_poll,
 572         .ioctl =        unix_ioctl,
 573         .listen =       unix_listen,
 574         .shutdown =     unix_shutdown,
 575         .setsockopt =   sock_no_setsockopt,
 576         .getsockopt =   sock_no_getsockopt,
 577         .sendmsg =      unix_seqpacket_sendmsg,
 578         .recvmsg =      unix_dgram_recvmsg,
 579         .mmap =         sock_no_mmap,
 580         .sendpage =     sock_no_sendpage,
 581 };
 582
 583 static struct proto unix_proto = {
 584         .name     = "UNIX",
 585         .owner    = THIS_MODULE,
 586         .obj_size = sizeof(struct unix_sock),
 587 };
 588
 589 /*
 590  * AF_UNIX sockets do not interact with hardware, hence they
 591  * dont trigger interrupts - so it's safe for them to have
 592  * bh-unsafe locking for their sk_receive_queue.lock. Split off
 593  * this special lock-class by reinitializing the spinlock key:
 594  */
 595 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
 596
 597 static struct sock * unix_create1(struct net *net, struct socket *sock)
 598 {
 599         struct sock *sk = NULL;
 600         struct unix_sock *u;
 601
 602         atomic_inc(&unix_nr_socks);
 603         if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
 604                 goto out;
 605
 606         sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
 607         if (!sk)
 608                 goto out;
 609
 610         sock_init_data(sock,sk);
 611         lockdep_set_class(&sk->sk_receive_queue.lock,
 612                                 &af_unix_sk_receive_queue_lock_key);
 613
 614         sk->sk_write_space      = unix_write_space;
 615         sk->sk_max_ack_backlog  = sysctl_unix_max_dgram_qlen;
 616         sk->sk_destruct         = unix_sock_destructor;
 617         u         = unix_sk(sk);
 618         u->dentry = NULL;
 619         u->mnt    = NULL;
 620         spin_lock_init(&u->lock);
 621         atomic_set(&u->inflight, 0);
 622         INIT_LIST_HEAD(&u->link);
 623         mutex_init(&u->readlock); /* single task reading lock */
 624         init_waitqueue_head(&u->peer_wait);
 625         unix_insert_socket(unix_sockets_unbound, sk);
 626 out:
 627         if (sk == NULL)
 628                 atomic_dec(&unix_nr_socks);
 629         return sk;
 630 }
 631
 632 static int unix_create(struct net *net, struct socket *sock, int protocol)
 633 {
 634         if (net != &init_net)
 635                 return -EAFNOSUPPORT;
 636
 637         if (protocol && protocol != PF_UNIX)
 638                 return -EPROTONOSUPPORT;
 639
 640         sock->state = SS_UNCONNECTED;
 641
 642         switch (sock->type) {
 643         case SOCK_STREAM:
 644                 sock->ops = &unix_stream_ops;
 645                 break;
 646                 /*
 647                  *      Believe it or not BSD has AF_UNIX, SOCK_RAW though
 648                  *      nothing uses it.
 649                  */
 650         case SOCK_RAW:
 651                 sock->type=SOCK_DGRAM;
 652         case SOCK_DGRAM:
 653                 sock->ops = &unix_dgram_ops;
 654                 break;
 655         case SOCK_SEQPACKET:
 656                 sock->ops = &unix_seqpacket_ops;
 657                 break;
 658         default:
 659                 return -ESOCKTNOSUPPORT;
 660         }
 661
 662         return unix_create1(net, sock) ? 0 : -ENOMEM;
 663 }
 664
 665 static int unix_release(struct socket *sock)
 666 {
 667         struct sock *sk = sock->sk;
 668
 669         if (!sk)
 670                 return 0;
 671
 672         sock->sk = NULL;
 673
 674         return unix_release_sock (sk, 0);
 675 }
 676
 677 static int unix_autobind(struct socket *sock)
 678 {
 679         struct sock *sk = sock->sk;
 680         struct unix_sock *u = unix_sk(sk);
 681         static u32 ordernum = 1;
 682         struct unix_address * addr;
 683         int err;
 684
 685         mutex_lock(&u->readlock);
 686
 687         err = 0;
 688         if (u->addr)
 689                 goto out;
 690
 691         err = -ENOMEM;
 692         addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
 693         if (!addr)
 694                 goto out;
 695
 696         addr->name->sun_family = AF_UNIX;
 697         atomic_set(&addr->refcnt, 1);
 698
 699 retry:
 700         addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
 701         addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
 702
 703         spin_lock(&unix_table_lock);
 704         ordernum = (ordernum+1)&0xFFFFF;
 705
 706         if (__unix_find_socket_byname(addr->name, addr->len, sock->type,
 707                                       addr->hash)) {
 708                 spin_unlock(&unix_table_lock);
 709                 /* Sanity yield. It is unusual case, but yet... */
 710                 if (!(ordernum&0xFF))
 711                         yield();
 712                 goto retry;
 713         }
 714         addr->hash ^= sk->sk_type;
 715
 716         __unix_remove_socket(sk);
 717         u->addr = addr;
 718         __unix_insert_socket(&unix_socket_table[addr->hash], sk);
 719         spin_unlock(&unix_table_lock);
 720         err = 0;
 721
 722 out:    mutex_unlock(&u->readlock);
 723         return err;
 724 }
 725
 726 static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
 727                                     int type, unsigned hash, int *error)
 728 {
 729         struct sock *u;
 730         struct nameidata nd;
 731         int err = 0;
 732
 733         if (sunname->sun_path[0]) {
 734                 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
 735                 if (err)
 736                         goto fail;
 737                 err = vfs_permission(&nd, MAY_WRITE);
 738                 if (err)
 739                         goto put_fail;
 740
 741                 err = -ECONNREFUSED;
 742                 if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
 743                         goto put_fail;
 744                 u=unix_find_socket_byinode(nd.dentry->d_inode);
 745                 if (!u)
 746                         goto put_fail;
 747
 748                 if (u->sk_type == type)
 749                         touch_atime(nd.mnt, nd.dentry);
 750
 751                 path_release(&nd);
 752
 753                 err=-EPROTOTYPE;
 754                 if (u->sk_type != type) {
 755                         sock_put(u);
 756                         goto fail;
 757                 }
 758         } else {
 759                 err = -ECONNREFUSED;
 760                 u=unix_find_socket_byname(sunname, len, type, hash);
 761                 if (u) {
 762                         struct dentry *dentry;
 763                         dentry = unix_sk(u)->dentry;
 764                         if (dentry)
 765                                 touch_atime(unix_sk(u)->mnt, dentry);
 766                 } else
 767                         goto fail;
 768         }
 769         return u;
 770
 771 put_fail:
 772         path_release(&nd);
 773 fail:
 774         *error=err;
 775         return NULL;
 776 }
 777
 778
 779 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 780 {
 781         struct sock *sk = sock->sk;
 782         struct unix_sock *u = unix_sk(sk);
 783         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
 784         struct dentry * dentry = NULL;
 785         struct nameidata nd;
 786         int err;
 787         unsigned hash;
 788         struct unix_address *addr;
 789         struct hlist_head *list;
 790
 791         err = -EINVAL;
 792         if (sunaddr->sun_family != AF_UNIX)
 793                 goto out;
 794
 795         if (addr_len==sizeof(short)) {
 796                 err = unix_autobind(sock);
 797                 goto out;
 798         }
 799
 800         err = unix_mkname(sunaddr, addr_len, &hash);
 801         if (err < 0)
 802                 goto out;
 803         addr_len = err;
 804
 805         mutex_lock(&u->readlock);
 806
 807         err = -EINVAL;
 808         if (u->addr)
 809                 goto out_up;
 810
 811         err = -ENOMEM;
 812         addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
 813         if (!addr)
 814                 goto out_up;
 815
 816         memcpy(addr->name, sunaddr, addr_len);
 817         addr->len = addr_len;
 818         addr->hash = hash ^ sk->sk_type;
 819         atomic_set(&addr->refcnt, 1);
 820
 821         if (sunaddr->sun_path[0]) {
 822                 unsigned int mode;
 823                 err = 0;
 824                 /*
 825                  * Get the parent directory, calculate the hash for last
 826                  * component.
 827                  */
 828                 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
 829                 if (err)
 830                         goto out_mknod_parent;
 831
 832                 dentry = lookup_create(&nd, 0);
 833                 err = PTR_ERR(dentry);
 834                 if (IS_ERR(dentry))
 835                         goto out_mknod_unlock;
 836
 837                 /*
 838                  * All right, let's create it.
 839                  */
 840                 mode = S_IFSOCK |
 841                        (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
 842                 err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
 843                 if (err)
 844                         goto out_mknod_dput;
 845                 mutex_unlock(&nd.dentry->d_inode->i_mutex);
 846                 dput(nd.dentry);
 847                 nd.dentry = dentry;
 848
 849                 addr->hash = UNIX_HASH_SIZE;
 850         }
 851
 852         spin_lock(&unix_table_lock);
 853
 854         if (!sunaddr->sun_path[0]) {
 855                 err = -EADDRINUSE;
 856                 if (__unix_find_socket_byname(sunaddr, addr_len,
 857                                               sk->sk_type, hash)) {
 858                         unix_release_addr(addr);
 859                         goto out_unlock;
 860                 }
 861
 862                 list = &unix_socket_table[addr->hash];
 863         } else {
 864                 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
 865                 u->dentry = nd.dentry;
 866                 u->mnt    = nd.mnt;
 867         }
 868
 869         err = 0;
 870         __unix_remove_socket(sk);
 871         u->addr = addr;
 872         __unix_insert_socket(list, sk);
 873
 874 out_unlock:
 875         spin_unlock(&unix_table_lock);
 876 out_up:
 877         mutex_unlock(&u->readlock);
 878 out:
 879         return err;
 880
 881 out_mknod_dput:
 882         dput(dentry);
 883 out_mknod_unlock:
 884         mutex_unlock(&nd.dentry->d_inode->i_mutex);
 885         path_release(&nd);
 886 out_mknod_parent:
 887         if (err==-EEXIST)
 888                 err=-EADDRINUSE;
 889         unix_release_addr(addr);
 890         goto out_up;
 891 }
 892
 893 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
 894 {
 895         if (unlikely(sk1 == sk2) || !sk2) {
 896                 unix_state_lock(sk1);
 897                 return;
 898         }
 899         if (sk1 < sk2) {
 900                 unix_state_lock(sk1);
 901                 unix_state_lock_nested(sk2);
 902         } else {
 903                 unix_state_lock(sk2);
 904                 unix_state_lock_nested(sk1);
 905         }
 906 }
 907
 908 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
 909 {
 910         if (unlikely(sk1 == sk2) || !sk2) {
 911                 unix_state_unlock(sk1);
 912                 return;
 913         }
 914         unix_state_unlock(sk1);
 915         unix_state_unlock(sk2);
 916 }
 917
 918 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 919                               int alen, int flags)
 920 {
 921         struct sock *sk = sock->sk;
 922         struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
 923         struct sock *other;
 924         unsigned hash;
 925         int err;
 926
 927         if (addr->sa_family != AF_UNSPEC) {
 928                 err = unix_mkname(sunaddr, alen, &hash);
 929                 if (err < 0)
 930                         goto out;
 931                 alen = err;
 932
 933                 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
 934                     !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
 935                         goto out;
 936
 937 restart:
 938                 other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
 939                 if (!other)
 940                         goto out;
 941
 942                 unix_state_double_lock(sk, other);
 943
 944                 /* Apparently VFS overslept socket death. Retry. */
 945                 if (sock_flag(other, SOCK_DEAD)) {
 946                         unix_state_double_unlock(sk, other);
 947                         sock_put(other);
 948                         goto restart;
 949                 }
 950
 951                 err = -EPERM;
 952                 if (!unix_may_send(sk, other))
 953                         goto out_unlock;
 954
 955                 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
 956                 if (err)
 957                         goto out_unlock;
 958
 959         } else {
 960                 /*
 961                  *      1003.1g breaking connected state with AF_UNSPEC
 962                  */
 963                 other = NULL;
 964                 unix_state_double_lock(sk, other);
 965         }
 966
 967         /*
 968          * If it was connected, reconnect.
 969          */
 970         if (unix_peer(sk)) {
 971                 struct sock *old_peer = unix_peer(sk);
 972                 unix_peer(sk)=other;
 973                 unix_state_double_unlock(sk, other);
 974
 975                 if (other != old_peer)
 976                         unix_dgram_disconnected(sk, old_peer);
 977                 sock_put(old_peer);
 978         } else {
 979                 unix_peer(sk)=other;
 980                 unix_state_double_unlock(sk, other);
 981         }
 982         return 0;
 983
 984 out_unlock:
 985         unix_state_double_unlock(sk, other);
 986         sock_put(other);
 987 out:
 988         return err;
 989 }
 990
 991 static long unix_wait_for_peer(struct sock *other, long timeo)
 992 {
 993         struct unix_sock *u = unix_sk(other);
 994         int sched;
 995         DEFINE_WAIT(wait);
 996
 997         prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
 998
 999         sched = !sock_flag(other, SOCK_DEAD) &&
1000                 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1001                 (skb_queue_len(&other->sk_receive_queue) >
1002                  other->sk_max_ack_backlog);
1003
1004         unix_state_unlock(other);
1005
1006         if (sched)
1007                 timeo = schedule_timeout(timeo);
1008
1009         finish_wait(&u->peer_wait, &wait);
1010         return timeo;
1011 }
1012
1013 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1014                                int addr_len, int flags)
1015 {
1016         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1017         struct sock *sk = sock->sk;
1018         struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1019         struct sock *newsk = NULL;
1020         struct sock *other = NULL;
1021         struct sk_buff *skb = NULL;
1022         unsigned hash;
1023         int st;
1024         int err;
1025         long timeo;
1026
1027         err = unix_mkname(sunaddr, addr_len, &hash);
1028         if (err < 0)
1029                 goto out;
1030         addr_len = err;
1031
1032         if (test_bit(SOCK_PASSCRED, &sock->flags)
1033                 && !u->addr && (err = unix_autobind(sock)) != 0)
1034                 goto out;
1035
1036         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1037
1038         /* First of all allocate resources.
1039            If we will make it after state is locked,
1040            we will have to recheck all again in any case.
1041          */
1042
1043         err = -ENOMEM;
1044
1045         /* create new sock for complete connection */
1046         newsk = unix_create1(sk->sk_net, NULL);
1047         if (newsk == NULL)
1048                 goto out;
1049
1050         /* Allocate skb for sending to listening sock */
1051         skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1052         if (skb == NULL)
1053                 goto out;
1054
1055 restart:
1056         /*  Find listening sock. */
1057         other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err);
1058         if (!other)
1059                 goto out;
1060
1061         /* Latch state of peer */
1062         unix_state_lock(other);
1063
1064         /* Apparently VFS overslept socket death. Retry. */
1065         if (sock_flag(other, SOCK_DEAD)) {
1066                 unix_state_unlock(other);
1067                 sock_put(other);
1068                 goto restart;
1069         }
1070
1071         err = -ECONNREFUSED;
1072         if (other->sk_state != TCP_LISTEN)
1073                 goto out_unlock;
1074
1075         if (skb_queue_len(&other->sk_receive_queue) >
1076             other->sk_max_ack_backlog) {
1077                 err = -EAGAIN;
1078                 if (!timeo)
1079                         goto out_unlock;
1080
1081                 timeo = unix_wait_for_peer(other, timeo);
1082
1083                 err = sock_intr_errno(timeo);
1084                 if (signal_pending(current))
1085                         goto out;
1086                 sock_put(other);
1087                 goto restart;
1088         }
1089
1090         /* Latch our state.
1091
1092            It is tricky place. We need to grab write lock and cannot
1093            drop lock on peer. It is dangerous because deadlock is
1094            possible. Connect to self case and simultaneous
1095            attempt to connect are eliminated by checking socket
1096            state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1097            check this before attempt to grab lock.
1098
1099            Well, and we have to recheck the state after socket locked.
1100          */
1101         st = sk->sk_state;
1102
1103         switch (st) {
1104         case TCP_CLOSE:
1105                 /* This is ok... continue with connect */
1106                 break;
1107         case TCP_ESTABLISHED:
1108                 /* Socket is already connected */
1109                 err = -EISCONN;
1110                 goto out_unlock;
1111         default:
1112                 err = -EINVAL;
1113                 goto out_unlock;
1114         }
1115
1116         unix_state_lock_nested(sk);
1117
1118         if (sk->sk_state != st) {
1119                 unix_state_unlock(sk);
1120                 unix_state_unlock(other);
1121                 sock_put(other);
1122                 goto restart;
1123         }
1124
1125         err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1126         if (err) {
1127                 unix_state_unlock(sk);
1128                 goto out_unlock;
1129         }
1130
1131         /* The way is open! Fastly set all the necessary fields... */
1132
1133         sock_hold(sk);
1134         unix_peer(newsk)        = sk;
1135         newsk->sk_state         = TCP_ESTABLISHED;
1136         newsk->sk_type          = sk->sk_type;
1137         newsk->sk_peercred.pid  = task_tgid_vnr(current);
1138         newsk->sk_peercred.uid  = current->euid;
1139         newsk->sk_peercred.gid  = current->egid;
1140         newu = unix_sk(newsk);
1141         newsk->sk_sleep         = &newu->peer_wait;
1142         otheru = unix_sk(other);
1143
1144         /* copy address information from listening to new sock*/
1145         if (otheru->addr) {
1146                 atomic_inc(&otheru->addr->refcnt);
1147                 newu->addr = otheru->addr;
1148         }
1149         if (otheru->dentry) {
1150                 newu->dentry    = dget(otheru->dentry);
1151                 newu->mnt       = mntget(otheru->mnt);
1152         }
1153
1154         /* Set credentials */
1155         sk->sk_peercred = other->sk_peercred;
1156
1157         sock->state     = SS_CONNECTED;
1158         sk->sk_state    = TCP_ESTABLISHED;
1159         sock_hold(newsk);
1160
1161         smp_mb__after_atomic_inc();     /* sock_hold() does an atomic_inc() */
1162         unix_peer(sk)   = newsk;
1163
1164         unix_state_unlock(sk);
1165
1166         /* take ten and and send info to listening sock */
1167         spin_lock(&other->sk_receive_queue.lock);
1168         __skb_queue_tail(&other->sk_receive_queue, skb);
1169         spin_unlock(&other->sk_receive_queue.lock);
1170         unix_state_unlock(other);
1171         other->sk_data_ready(other, 0);
1172         sock_put(other);
1173         return 0;
1174
1175 out_unlock:
1176         if (other)
1177                 unix_state_unlock(other);
1178
1179 out:
1180         if (skb)
1181                 kfree_skb(skb);
1182         if (newsk)
1183                 unix_release_sock(newsk, 0);
1184         if (other)
1185                 sock_put(other);
1186         return err;
1187 }
1188
1189 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1190 {
1191         struct sock *ska=socka->sk, *skb = sockb->sk;
1192
1193         /* Join our sockets back to back */
1194         sock_hold(ska);
1195         sock_hold(skb);
1196         unix_peer(ska)=skb;
1197         unix_peer(skb)=ska;
1198         ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
1199         ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid;
1200         ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid;
1201
1202         if (ska->sk_type != SOCK_DGRAM) {
1203                 ska->sk_state = TCP_ESTABLISHED;
1204                 skb->sk_state = TCP_ESTABLISHED;
1205                 socka->state  = SS_CONNECTED;
1206                 sockb->state  = SS_CONNECTED;
1207         }
1208         return 0;
1209 }
1210
1211 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1212 {
1213         struct sock *sk = sock->sk;
1214         struct sock *tsk;
1215         struct sk_buff *skb;
1216         int err;
1217
1218         err = -EOPNOTSUPP;
1219         if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1220                 goto out;
1221
1222         err = -EINVAL;
1223         if (sk->sk_state != TCP_LISTEN)
1224                 goto out;
1225
1226         /* If socket state is TCP_LISTEN it cannot change (for now...),
1227          * so that no locks are necessary.
1228          */
1229
1230         skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1231         if (!skb) {
1232                 /* This means receive shutdown. */
1233                 if (err == 0)
1234                         err = -EINVAL;
1235                 goto out;
1236         }
1237
1238         tsk = skb->sk;
1239         skb_free_datagram(sk, skb);
1240         wake_up_interruptible(&unix_sk(sk)->peer_wait);
1241
1242         /* attach accepted sock to socket */
1243         unix_state_lock(tsk);
1244         newsock->state = SS_CONNECTED;
1245         sock_graft(tsk, newsock);
1246         unix_state_unlock(tsk);
1247         return 0;
1248
1249 out:
1250         return err;
1251 }
1252
1253
1254 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1255 {
1256         struct sock *sk = sock->sk;
1257         struct unix_sock *u;
1258         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1259         int err = 0;
1260
1261         if (peer) {
1262                 sk = unix_peer_get(sk);
1263
1264                 err = -ENOTCONN;
1265                 if (!sk)
1266                         goto out;
1267                 err = 0;
1268         } else {
1269                 sock_hold(sk);
1270         }
1271
1272         u = unix_sk(sk);
1273         unix_state_lock(sk);
1274         if (!u->addr) {
1275                 sunaddr->sun_family = AF_UNIX;
1276                 sunaddr->sun_path[0] = 0;
1277                 *uaddr_len = sizeof(short);
1278         } else {
1279                 struct unix_address *addr = u->addr;
1280
1281                 *uaddr_len = addr->len;
1282                 memcpy(sunaddr, addr->name, *uaddr_len);
1283         }
1284         unix_state_unlock(sk);
1285         sock_put(sk);
1286 out:
1287         return err;
1288 }
1289
1290 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1291 {
1292         int i;
1293
1294         scm->fp = UNIXCB(skb).fp;
1295         skb->destructor = sock_wfree;
1296         UNIXCB(skb).fp = NULL;
1297
1298         for (i=scm->fp->count-1; i>=0; i--)
1299                 unix_notinflight(scm->fp->fp[i]);
1300 }
1301
1302 static void unix_destruct_fds(struct sk_buff *skb)
1303 {
1304         struct scm_cookie scm;
1305         memset(&scm, 0, sizeof(scm));
1306         unix_detach_fds(&scm, skb);
1307
1308         /* Alas, it calls VFS */
1309         /* So fscking what? fput() had been SMP-safe since the last Summer */
1310         scm_destroy(&scm);
1311         sock_wfree(skb);
1312 }
1313
1314 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1315 {
1316         int i;
1317         for (i=scm->fp->count-1; i>=0; i--)
1318                 unix_inflight(scm->fp->fp[i]);
1319         UNIXCB(skb).fp = scm->fp;
1320         skb->destructor = unix_destruct_fds;
1321         scm->fp = NULL;
1322 }
1323
1324 /*
1325  *      Send AF_UNIX data.
1326  */
1327
1328 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1329                               struct msghdr *msg, size_t len)
1330 {
1331         struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1332         struct sock *sk = sock->sk;
1333         struct unix_sock *u = unix_sk(sk);
1334         struct sockaddr_un *sunaddr=msg->msg_name;
1335         struct sock *other = NULL;
1336         int namelen = 0; /* fake GCC */
1337         int err;
1338         unsigned hash;
1339         struct sk_buff *skb;
1340         long timeo;
1341         struct scm_cookie tmp_scm;
1342
1343         if (NULL == siocb->scm)
1344                 siocb->scm = &tmp_scm;
1345         err = scm_send(sock, msg, siocb->scm);
1346         if (err < 0)
1347                 return err;
1348
1349         err = -EOPNOTSUPP;
1350         if (msg->msg_flags&MSG_OOB)
1351                 goto out;
1352
1353         if (msg->msg_namelen) {
1354                 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1355                 if (err < 0)
1356                         goto out;
1357                 namelen = err;
1358         } else {
1359                 sunaddr = NULL;
1360                 err = -ENOTCONN;
1361                 other = unix_peer_get(sk);
1362                 if (!other)
1363                         goto out;
1364         }
1365
1366         if (test_bit(SOCK_PASSCRED, &sock->flags)
1367                 && !u->addr && (err = unix_autobind(sock)) != 0)
1368                 goto out;
1369
1370         err = -EMSGSIZE;
1371         if (len > sk->sk_sndbuf - 32)
1372                 goto out;
1373
1374         skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1375         if (skb==NULL)
1376                 goto out;
1377
1378         memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1379         if (siocb->scm->fp)
1380                 unix_attach_fds(siocb->scm, skb);
1381         unix_get_secdata(siocb->scm, skb);
1382
1383         skb_reset_transport_header(skb);
1384         err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1385         if (err)
1386                 goto out_free;
1387
1388         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1389
1390 restart:
1391         if (!other) {
1392                 err = -ECONNRESET;
1393                 if (sunaddr == NULL)
1394                         goto out_free;
1395
1396                 other = unix_find_other(sunaddr, namelen, sk->sk_type,
1397                                         hash, &err);
1398                 if (other==NULL)
1399                         goto out_free;
1400         }
1401
1402         unix_state_lock(other);
1403         err = -EPERM;
1404         if (!unix_may_send(sk, other))
1405                 goto out_unlock;
1406
1407         if (sock_flag(other, SOCK_DEAD)) {
1408                 /*
1409                  *      Check with 1003.1g - what should
1410                  *      datagram error
1411                  */
1412                 unix_state_unlock(other);
1413                 sock_put(other);
1414
1415                 err = 0;
1416                 unix_state_lock(sk);
1417                 if (unix_peer(sk) == other) {
1418                         unix_peer(sk)=NULL;
1419                         unix_state_unlock(sk);
1420
1421                         unix_dgram_disconnected(sk, other);
1422                         sock_put(other);
1423                         err = -ECONNREFUSED;
1424                 } else {
1425                         unix_state_unlock(sk);
1426                 }
1427
1428                 other = NULL;
1429                 if (err)
1430                         goto out_free;
1431                 goto restart;
1432         }
1433
1434         err = -EPIPE;
1435         if (other->sk_shutdown & RCV_SHUTDOWN)
1436                 goto out_unlock;
1437
1438         if (sk->sk_type != SOCK_SEQPACKET) {
1439                 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1440                 if (err)
1441                         goto out_unlock;
1442         }
1443
1444         if (unix_peer(other) != sk &&
1445             (skb_queue_len(&other->sk_receive_queue) >
1446              other->sk_max_ack_backlog)) {
1447                 if (!timeo) {
1448                         err = -EAGAIN;
1449                         goto out_unlock;
1450                 }
1451
1452                 timeo = unix_wait_for_peer(other, timeo);
1453
1454                 err = sock_intr_errno(timeo);
1455                 if (signal_pending(current))
1456                         goto out_free;
1457
1458                 goto restart;
1459         }
1460
1461         skb_queue_tail(&other->sk_receive_queue, skb);
1462         unix_state_unlock(other);
1463         other->sk_data_ready(other, len);
1464         sock_put(other);
1465         scm_destroy(siocb->scm);
1466         return len;
1467
1468 out_unlock:
1469         unix_state_unlock(other);
1470 out_free:
1471         kfree_skb(skb);
1472 out:
1473         if (other)
1474                 sock_put(other);
1475         scm_destroy(siocb->scm);
1476         return err;
1477 }
1478
1479
1480 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1481                                struct msghdr *msg, size_t len)
1482 {
1483         struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1484         struct sock *sk = sock->sk;
1485         struct sock *other = NULL;
1486         struct sockaddr_un *sunaddr=msg->msg_name;
1487         int err,size;
1488         struct sk_buff *skb;
1489         int sent=0;
1490         struct scm_cookie tmp_scm;
1491
1492         if (NULL == siocb->scm)
1493                 siocb->scm = &tmp_scm;
1494         err = scm_send(sock, msg, siocb->scm);
1495         if (err < 0)
1496                 return err;
1497
1498         err = -EOPNOTSUPP;
1499         if (msg->msg_flags&MSG_OOB)
1500                 goto out_err;
1501
1502         if (msg->msg_namelen) {
1503                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1504                 goto out_err;
1505         } else {
1506                 sunaddr = NULL;
1507                 err = -ENOTCONN;
1508                 other = unix_peer(sk);
1509                 if (!other)
1510                         goto out_err;
1511         }
1512
1513         if (sk->sk_shutdown & SEND_SHUTDOWN)
1514                 goto pipe_err;
1515
1516         while(sent < len)
1517         {
1518                 /*
1519                  *      Optimisation for the fact that under 0.01% of X
1520                  *      messages typically need breaking up.
1521                  */
1522
1523                 size = len-sent;
1524
1525                 /* Keep two messages in the pipe so it schedules better */
1526                 if (size > ((sk->sk_sndbuf >> 1) - 64))
1527                         size = (sk->sk_sndbuf >> 1) - 64;
1528
1529                 if (size > SKB_MAX_ALLOC)
1530                         size = SKB_MAX_ALLOC;
1531
1532                 /*
1533                  *      Grab a buffer
1534                  */
1535
1536                 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1537
1538                 if (skb==NULL)
1539                         goto out_err;
1540
1541                 /*
1542                  *      If you pass two values to the sock_alloc_send_skb
1543                  *      it tries to grab the large buffer with GFP_NOFS
1544                  *      (which can fail easily), and if it fails grab the
1545                  *      fallback size buffer which is under a page and will
1546                  *      succeed. [Alan]
1547                  */
1548                 size = min_t(int, size, skb_tailroom(skb));
1549
1550                 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1551                 if (siocb->scm->fp)
1552                         unix_attach_fds(siocb->scm, skb);
1553
1554                 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1555                         kfree_skb(skb);
1556                         goto out_err;
1557                 }
1558
1559                 unix_state_lock(other);
1560
1561                 if (sock_flag(other, SOCK_DEAD) ||
1562                     (other->sk_shutdown & RCV_SHUTDOWN))
1563                         goto pipe_err_free;
1564
1565                 skb_queue_tail(&other->sk_receive_queue, skb);
1566                 unix_state_unlock(other);
1567                 other->sk_data_ready(other, size);
1568                 sent+=size;
1569         }
1570
1571         scm_destroy(siocb->scm);
1572         siocb->scm = NULL;
1573
1574         return sent;
1575
1576 pipe_err_free:
1577         unix_state_unlock(other);
1578         kfree_skb(skb);
1579 pipe_err:
1580         if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1581                 send_sig(SIGPIPE,current,0);
1582         err = -EPIPE;
1583 out_err:
1584         scm_destroy(siocb->scm);
1585         siocb->scm = NULL;
1586         return sent ? : err;
1587 }
1588
1589 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1590                                   struct msghdr *msg, size_t len)
1591 {
1592         int err;
1593         struct sock *sk = sock->sk;
1594
1595         err = sock_error(sk);
1596         if (err)
1597                 return err;
1598
1599         if (sk->sk_state != TCP_ESTABLISHED)
1600                 return -ENOTCONN;
1601
1602         if (msg->msg_namelen)
1603                 msg->msg_namelen = 0;
1604
1605         return unix_dgram_sendmsg(kiocb, sock, msg, len);
1606 }
1607
1608 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1609 {
1610         struct unix_sock *u = unix_sk(sk);
1611
1612         msg->msg_namelen = 0;
1613         if (u->addr) {
1614                 msg->msg_namelen = u->addr->len;
1615                 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1616         }
1617 }
1618
1619 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1620                               struct msghdr *msg, size_t size,
1621                               int flags)
1622 {
1623         struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1624         struct scm_cookie tmp_scm;
1625         struct sock *sk = sock->sk;
1626         struct unix_sock *u = unix_sk(sk);
1627         int noblock = flags & MSG_DONTWAIT;
1628         struct sk_buff *skb;
1629         int err;
1630
1631         err = -EOPNOTSUPP;
1632         if (flags&MSG_OOB)
1633                 goto out;
1634
1635         msg->msg_namelen = 0;
1636
1637         mutex_lock(&u->readlock);
1638
1639         skb = skb_recv_datagram(sk, flags, noblock, &err);
1640         if (!skb) {
1641                 unix_state_lock(sk);
1642                 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1643                 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1644                     (sk->sk_shutdown & RCV_SHUTDOWN))
1645                         err = 0;
1646                 unix_state_unlock(sk);
1647                 goto out_unlock;
1648         }
1649
1650         wake_up_interruptible_sync(&u->peer_wait);
1651
1652         if (msg->msg_name)
1653                 unix_copy_addr(msg, skb->sk);
1654
1655         if (size > skb->len)
1656                 size = skb->len;
1657         else if (size < skb->len)
1658                 msg->msg_flags |= MSG_TRUNC;
1659
1660         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1661         if (err)
1662                 goto out_free;
1663
1664         if (!siocb->scm) {
1665                 siocb->scm = &tmp_scm;
1666                 memset(&tmp_scm, 0, sizeof(tmp_scm));
1667         }
1668         siocb->scm->creds = *UNIXCREDS(skb);
1669         unix_set_secdata(siocb->scm, skb);
1670
1671         if (!(flags & MSG_PEEK))
1672         {
1673                 if (UNIXCB(skb).fp)
1674                         unix_detach_fds(siocb->scm, skb);
1675         }
1676         else
1677         {
1678                 /* It is questionable: on PEEK we could:
1679                    - do not return fds - good, but too simple 8)
1680                    - return fds, and do not return them on read (old strategy,
1681                      apparently wrong)
1682                    - clone fds (I chose it for now, it is the most universal
1683                      solution)
1684
1685                    POSIX 1003.1g does not actually define this clearly
1686                    at all. POSIX 1003.1g doesn't define a lot of things
1687                    clearly however!
1688
1689                 */
1690                 if (UNIXCB(skb).fp)
1691                         siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1692         }
1693         err = size;
1694
1695         scm_recv(sock, msg, siocb->scm, flags);
1696
1697 out_free:
1698         skb_free_datagram(sk,skb);
1699 out_unlock:
1700         mutex_unlock(&u->readlock);
1701 out:
1702         return err;
1703 }
1704
1705 /*
1706  *      Sleep until data has arrive. But check for races..
1707  */
1708
1709 static long unix_stream_data_wait(struct sock * sk, long timeo)
1710 {
1711         DEFINE_WAIT(wait);
1712
1713         unix_state_lock(sk);
1714
1715         for (;;) {
1716                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1717
1718                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1719                     sk->sk_err ||
1720                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1721                     signal_pending(current) ||
1722                     !timeo)
1723                         break;
1724
1725                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1726                 unix_state_unlock(sk);
1727                 timeo = schedule_timeout(timeo);
1728                 unix_state_lock(sk);
1729                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1730         }
1731
1732         finish_wait(sk->sk_sleep, &wait);
1733         unix_state_unlock(sk);
1734         return timeo;
1735 }
1736
1737
1738
1739 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1740                                struct msghdr *msg, size_t size,
1741                                int flags)
1742 {
1743         struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1744         struct scm_cookie tmp_scm;
1745         struct sock *sk = sock->sk;
1746         struct unix_sock *u = unix_sk(sk);
1747         struct sockaddr_un *sunaddr=msg->msg_name;
1748         int copied = 0;
1749         int check_creds = 0;
1750         int target;
1751         int err = 0;
1752         long timeo;
1753
1754         err = -EINVAL;
1755         if (sk->sk_state != TCP_ESTABLISHED)
1756                 goto out;
1757
1758         err = -EOPNOTSUPP;
1759         if (flags&MSG_OOB)
1760                 goto out;
1761
1762         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1763         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1764
1765         msg->msg_namelen = 0;
1766
1767         /* Lock the socket to prevent queue disordering
1768          * while sleeps in memcpy_tomsg
1769          */
1770
1771         if (!siocb->scm) {
1772                 siocb->scm = &tmp_scm;
1773                 memset(&tmp_scm, 0, sizeof(tmp_scm));
1774         }
1775
1776         mutex_lock(&u->readlock);
1777
1778         do
1779         {
1780                 int chunk;
1781                 struct sk_buff *skb;
1782
1783                 unix_state_lock(sk);
1784                 skb = skb_dequeue(&sk->sk_receive_queue);
1785                 if (skb==NULL)
1786                 {
1787                         if (copied >= target)
1788                                 goto unlock;
1789
1790                         /*
1791                          *      POSIX 1003.1g mandates this order.
1792                          */
1793
1794                         if ((err = sock_error(sk)) != 0)
1795                                 goto unlock;
1796                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1797                                 goto unlock;
1798
1799                         unix_state_unlock(sk);
1800                         err = -EAGAIN;
1801                         if (!timeo)
1802                                 break;
1803                         mutex_unlock(&u->readlock);
1804
1805                         timeo = unix_stream_data_wait(sk, timeo);
1806
1807                         if (signal_pending(current)) {
1808                                 err = sock_intr_errno(timeo);
1809                                 goto out;
1810                         }
1811                         mutex_lock(&u->readlock);
1812                         continue;
1813  unlock:
1814                         unix_state_unlock(sk);
1815                         break;
1816                 }
1817                 unix_state_unlock(sk);
1818
1819                 if (check_creds) {
1820                         /* Never glue messages from different writers */
1821                         if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1822                                 skb_queue_head(&sk->sk_receive_queue, skb);
1823                                 break;
1824                         }
1825                 } else {
1826                         /* Copy credentials */
1827                         siocb->scm->creds = *UNIXCREDS(skb);
1828                         check_creds = 1;
1829                 }
1830
1831                 /* Copy address just once */
1832                 if (sunaddr)
1833                 {
1834                         unix_copy_addr(msg, skb->sk);
1835                         sunaddr = NULL;
1836                 }
1837
1838                 chunk = min_t(unsigned int, skb->len, size);
1839                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1840                         skb_queue_head(&sk->sk_receive_queue, skb);
1841                         if (copied == 0)
1842                                 copied = -EFAULT;
1843                         break;
1844                 }
1845                 copied += chunk;
1846                 size -= chunk;
1847
1848                 /* Mark read part of skb as used */
1849                 if (!(flags & MSG_PEEK))
1850                 {
1851                         skb_pull(skb, chunk);
1852
1853                         if (UNIXCB(skb).fp)
1854                                 unix_detach_fds(siocb->scm, skb);
1855
1856                         /* put the skb back if we didn't use it up.. */
1857                         if (skb->len)
1858                         {
1859                                 skb_queue_head(&sk->sk_receive_queue, skb);
1860                                 break;
1861                         }
1862
1863                         kfree_skb(skb);
1864
1865                         if (siocb->scm->fp)
1866                                 break;
1867                 }
1868                 else
1869                 {
1870                         /* It is questionable, see note in unix_dgram_recvmsg.
1871                          */
1872                         if (UNIXCB(skb).fp)
1873                                 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1874
1875                         /* put message back and return */
1876                         skb_queue_head(&sk->sk_receive_queue, skb);
1877                         break;
1878                 }
1879         } while (size);
1880
1881         mutex_unlock(&u->readlock);
1882         scm_recv(sock, msg, siocb->scm, flags);
1883 out:
1884         return copied ? : err;
1885 }
1886
1887 static int unix_shutdown(struct socket *sock, int mode)
1888 {
1889         struct sock *sk = sock->sk;
1890         struct sock *other;
1891
1892         mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1893
1894         if (mode) {
1895                 unix_state_lock(sk);
1896                 sk->sk_shutdown |= mode;
1897                 other=unix_peer(sk);
1898                 if (other)
1899                         sock_hold(other);
1900                 unix_state_unlock(sk);
1901                 sk->sk_state_change(sk);
1902
1903                 if (other &&
1904                         (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1905
1906                         int peer_mode = 0;
1907
1908                         if (mode&RCV_SHUTDOWN)
1909                                 peer_mode |= SEND_SHUTDOWN;
1910                         if (mode&SEND_SHUTDOWN)
1911                                 peer_mode |= RCV_SHUTDOWN;
1912                         unix_state_lock(other);
1913                         other->sk_shutdown |= peer_mode;
1914                         unix_state_unlock(other);
1915                         other->sk_state_change(other);
1916                         read_lock(&other->sk_callback_lock);
1917                         if (peer_mode == SHUTDOWN_MASK)
1918                                 sk_wake_async(other,1,POLL_HUP);
1919                         else if (peer_mode & RCV_SHUTDOWN)
1920                                 sk_wake_async(other,1,POLL_IN);
1921                         read_unlock(&other->sk_callback_lock);
1922                 }
1923                 if (other)
1924                         sock_put(other);
1925         }
1926         return 0;
1927 }
1928
1929 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1930 {
1931         struct sock *sk = sock->sk;
1932         long amount=0;
1933         int err;
1934
1935         switch(cmd)
1936         {
1937                 case SIOCOUTQ:
1938                         amount = atomic_read(&sk->sk_wmem_alloc);
1939                         err = put_user(amount, (int __user *)arg);
1940                         break;
1941                 case SIOCINQ:
1942                 {
1943                         struct sk_buff *skb;
1944
1945                         if (sk->sk_state == TCP_LISTEN) {
1946                                 err = -EINVAL;
1947                                 break;
1948                         }
1949
1950                         spin_lock(&sk->sk_receive_queue.lock);
1951                         if (sk->sk_type == SOCK_STREAM ||
1952                             sk->sk_type == SOCK_SEQPACKET) {
1953                                 skb_queue_walk(&sk->sk_receive_queue, skb)
1954                                         amount += skb->len;
1955                         } else {
1956                                 skb = skb_peek(&sk->sk_receive_queue);
1957                                 if (skb)
1958                                         amount=skb->len;
1959                         }
1960                         spin_unlock(&sk->sk_receive_queue.lock);
1961                         err = put_user(amount, (int __user *)arg);
1962                         break;
1963                 }
1964
1965                 default:
1966                         err = -ENOIOCTLCMD;
1967                         break;
1968         }
1969         return err;
1970 }
1971
1972 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1973 {
1974         struct sock *sk = sock->sk;
1975         unsigned int mask;
1976
1977         poll_wait(file, sk->sk_sleep, wait);
1978         mask = 0;
1979
1980         /* exceptional events? */
1981         if (sk->sk_err)
1982                 mask |= POLLERR;
1983         if (sk->sk_shutdown == SHUTDOWN_MASK)
1984                 mask |= POLLHUP;
1985         if (sk->sk_shutdown & RCV_SHUTDOWN)
1986                 mask |= POLLRDHUP;
1987
1988         /* readable? */
1989         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1990             (sk->sk_shutdown & RCV_SHUTDOWN))
1991                 mask |= POLLIN | POLLRDNORM;
1992
1993         /* Connection-based need to check for termination and startup */
1994         if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
1995                 mask |= POLLHUP;
1996
1997         /*
1998          * we set writable also when the other side has shut down the
1999          * connection. This prevents stuck sockets.
2000          */
2001         if (unix_writable(sk))
2002                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2003
2004         return mask;
2005 }
2006
2007
2008 #ifdef CONFIG_PROC_FS
2009 static struct sock *unix_seq_idx(int *iter, loff_t pos)
2010 {
2011         loff_t off = 0;
2012         struct sock *s;
2013
2014         for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) {
2015                 if (off == pos)
2016                         return s;
2017                 ++off;
2018         }
2019         return NULL;
2020 }
2021
2022
2023 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2024 {
2025         spin_lock(&unix_table_lock);
2026         return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1);
2027 }
2028
2029 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2030 {
2031         ++*pos;
2032
2033         if (v == (void *)1)
2034                 return first_unix_socket(seq->private);
2035         return next_unix_socket(seq->private, v);
2036 }
2037
2038 static void unix_seq_stop(struct seq_file *seq, void *v)
2039 {
2040         spin_unlock(&unix_table_lock);
2041 }
2042
2043 static int unix_seq_show(struct seq_file *seq, void *v)
2044 {
2045
2046         if (v == (void *)1)
2047                 seq_puts(seq, "Num       RefCount Protocol Flags    Type St "
2048                          "Inode Path\n");
2049         else {
2050                 struct sock *s = v;
2051                 struct unix_sock *u = unix_sk(s);
2052                 unix_state_lock(s);
2053
2054                 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2055                         s,
2056                         atomic_read(&s->sk_refcnt),
2057                         0,
2058                         s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2059                         s->sk_type,
2060                         s->sk_socket ?
2061                         (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2062                         (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2063                         sock_i_ino(s));
2064
2065                 if (u->addr) {
2066                         int i, len;
2067                         seq_putc(seq, ' ');
2068
2069                         i = 0;
2070                         len = u->addr->len - sizeof(short);
2071                         if (!UNIX_ABSTRACT(s))
2072                                 len--;
2073                         else {
2074                                 seq_putc(seq, '@');
2075                                 i++;
2076                         }
2077                         for ( ; i < len; i++)
2078                                 seq_putc(seq, u->addr->name->sun_path[i]);
2079                 }
2080                 unix_state_unlock(s);
2081                 seq_putc(seq, '\n');
2082         }
2083
2084         return 0;
2085 }
2086
2087 static const struct seq_operations unix_seq_ops = {
2088         .start  = unix_seq_start,
2089         .next   = unix_seq_next,
2090         .stop   = unix_seq_stop,
2091         .show   = unix_seq_show,
2092 };
2093
2094
2095 static int unix_seq_open(struct inode *inode, struct file *file)
2096 {
2097         return seq_open_private(file, &unix_seq_ops, sizeof(int));
2098 }
2099
2100 static const struct file_operations unix_seq_fops = {
2101         .owner          = THIS_MODULE,
2102         .open           = unix_seq_open,
2103         .read           = seq_read,
2104         .llseek         = seq_lseek,
2105         .release        = seq_release_private,
2106 };
2107
2108 #endif
2109
2110 static struct net_proto_family unix_family_ops = {
2111         .family = PF_UNIX,
2112         .create = unix_create,
2113         .owner  = THIS_MODULE,
2114 };
2115
2116 static int __init af_unix_init(void)
2117 {
2118         int rc = -1;
2119         struct sk_buff *dummy_skb;
2120
2121         BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2122
2123         rc = proto_register(&unix_proto, 1);
2124         if (rc != 0) {
2125                 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2126                        __FUNCTION__);
2127                 goto out;
2128         }
2129
2130         sock_register(&unix_family_ops);
2131 #ifdef CONFIG_PROC_FS
2132         proc_net_fops_create(&init_net, "unix", 0, &unix_seq_fops);
2133 #endif
2134         unix_sysctl_register();
2135 out:
2136         return rc;
2137 }
2138
2139 static void __exit af_unix_exit(void)
2140 {
2141         sock_unregister(PF_UNIX);
2142         unix_sysctl_unregister();
2143         proc_net_remove(&init_net, "unix");
2144         proto_unregister(&unix_proto);
2145 }
2146
2147 module_init(af_unix_init);
2148 module_exit(af_unix_exit);
2149
2150 MODULE_LICENSE("GPL");
2151 MODULE_ALIAS_NETPROTO(PF_UNIX);