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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 net *net,
 274                                               struct sockaddr_un *sunname,
 275                                               int len, int type, unsigned hash)
 276 {
 277         struct sock *s;
 278         struct hlist_node *node;
 279
 280         sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
 281                 struct unix_sock *u = unix_sk(s);
 282
 283                 if (s->sk_net != net)
 284                         continue;
 285
 286                 if (u->addr->len == len &&
 287                     !memcmp(u->addr->name, sunname, len))
 288                         goto found;
 289         }
 290         s = NULL;
 291 found:
 292         return s;
 293 }
 294
 295 static inline struct sock *unix_find_socket_byname(struct net *net,
 296                                                    struct sockaddr_un *sunname,
 297                                                    int len, int type,
 298                                                    unsigned hash)
 299 {
 300         struct sock *s;
 301
 302         spin_lock(&unix_table_lock);
 303         s = __unix_find_socket_byname(net, sunname, len, type, hash);
 304         if (s)
 305                 sock_hold(s);
 306         spin_unlock(&unix_table_lock);
 307         return s;
 308 }
 309
 310 static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
 311 {
 312         struct sock *s;
 313         struct hlist_node *node;
 314
 315         spin_lock(&unix_table_lock);
 316         sk_for_each(s, node,
 317                     &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
 318                 struct dentry *dentry = unix_sk(s)->dentry;
 319
 320                 if (s->sk_net != net)
 321                         continue;
 322
 323                 if(dentry && dentry->d_inode == i)
 324                 {
 325                         sock_hold(s);
 326                         goto found;
 327                 }
 328         }
 329         s = NULL;
 330 found:
 331         spin_unlock(&unix_table_lock);
 332         return s;
 333 }
 334
 335 static inline int unix_writable(struct sock *sk)
 336 {
 337         return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
 338 }
 339
 340 static void unix_write_space(struct sock *sk)
 341 {
 342         read_lock(&sk->sk_callback_lock);
 343         if (unix_writable(sk)) {
 344                 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 345                         wake_up_interruptible_sync(sk->sk_sleep);
 346                 sk_wake_async(sk, 2, POLL_OUT);
 347         }
 348         read_unlock(&sk->sk_callback_lock);
 349 }
 350
 351 /* When dgram socket disconnects (or changes its peer), we clear its receive
 352  * queue of packets arrived from previous peer. First, it allows to do
 353  * flow control based only on wmem_alloc; second, sk connected to peer
 354  * may receive messages only from that peer. */
 355 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)
 356 {
 357         if (!skb_queue_empty(&sk->sk_receive_queue)) {
 358                 skb_queue_purge(&sk->sk_receive_queue);
 359                 wake_up_interruptible_all(&unix_sk(sk)->peer_wait);
 360
 361                 /* If one link of bidirectional dgram pipe is disconnected,
 362                  * we signal error. Messages are lost. Do not make this,
 363                  * when peer was not connected to us.
 364                  */
 365                 if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {
 366                         other->sk_err = ECONNRESET;
 367                         other->sk_error_report(other);
 368                 }
 369         }
 370 }
 371
 372 static void unix_sock_destructor(struct sock *sk)
 373 {
 374         struct unix_sock *u = unix_sk(sk);
 375
 376         skb_queue_purge(&sk->sk_receive_queue);
 377
 378         BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
 379         BUG_TRAP(sk_unhashed(sk));
 380         BUG_TRAP(!sk->sk_socket);
 381         if (!sock_flag(sk, SOCK_DEAD)) {
 382                 printk("Attempt to release alive unix socket: %p\n", sk);
 383                 return;
 384         }
 385
 386         if (u->addr)
 387                 unix_release_addr(u->addr);
 388
 389         atomic_dec(&unix_nr_socks);
 390 #ifdef UNIX_REFCNT_DEBUG
 391         printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
 392 #endif
 393 }
 394
 395 static int unix_release_sock (struct sock *sk, int embrion)
 396 {
 397         struct unix_sock *u = unix_sk(sk);
 398         struct dentry *dentry;
 399         struct vfsmount *mnt;
 400         struct sock *skpair;
 401         struct sk_buff *skb;
 402         int state;
 403
 404         unix_remove_socket(sk);
 405
 406         /* Clear state */
 407         unix_state_lock(sk);
 408         sock_orphan(sk);
 409         sk->sk_shutdown = SHUTDOWN_MASK;
 410         dentry       = u->dentry;
 411         u->dentry    = NULL;
 412         mnt          = u->mnt;
 413         u->mnt       = NULL;
 414         state = sk->sk_state;
 415         sk->sk_state = TCP_CLOSE;
 416         unix_state_unlock(sk);
 417
 418         wake_up_interruptible_all(&u->peer_wait);
 419
 420         skpair=unix_peer(sk);
 421
 422         if (skpair!=NULL) {
 423                 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
 424                         unix_state_lock(skpair);
 425                         /* No more writes */
 426                         skpair->sk_shutdown = SHUTDOWN_MASK;
 427                         if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
 428                                 skpair->sk_err = ECONNRESET;
 429                         unix_state_unlock(skpair);
 430                         skpair->sk_state_change(skpair);
 431                         read_lock(&skpair->sk_callback_lock);
 432                         sk_wake_async(skpair,1,POLL_HUP);
 433                         read_unlock(&skpair->sk_callback_lock);
 434                 }
 435                 sock_put(skpair); /* It may now die */
 436                 unix_peer(sk) = NULL;
 437         }
 438
 439         /* Try to flush out this socket. Throw out buffers at least */
 440
 441         while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 442                 if (state==TCP_LISTEN)
 443                         unix_release_sock(skb->sk, 1);
 444                 /* passed fds are erased in the kfree_skb hook        */
 445                 kfree_skb(skb);
 446         }
 447
 448         if (dentry) {
 449                 dput(dentry);
 450                 mntput(mnt);
 451         }
 452
 453         sock_put(sk);
 454
 455         /* ---- Socket is dead now and most probably destroyed ---- */
 456
 457         /*
 458          * Fixme: BSD difference: In BSD all sockets connected to use get
 459          *        ECONNRESET and we die on the spot. In Linux we behave
 460          *        like files and pipes do and wait for the last
 461          *        dereference.
 462          *
 463          * Can't we simply set sock->err?
 464          *
 465          *        What the above comment does talk about? --ANK(980817)
 466          */
 467
 468         if (unix_tot_inflight)
 469                 unix_gc();              /* Garbage collect fds */
 470
 471         return 0;
 472 }
 473
 474 static int unix_listen(struct socket *sock, int backlog)
 475 {
 476         int err;
 477         struct sock *sk = sock->sk;
 478         struct unix_sock *u = unix_sk(sk);
 479
 480         err = -EOPNOTSUPP;
 481         if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
 482                 goto out;                       /* Only stream/seqpacket sockets accept */
 483         err = -EINVAL;
 484         if (!u->addr)
 485                 goto out;                       /* No listens on an unbound socket */
 486         unix_state_lock(sk);
 487         if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
 488                 goto out_unlock;
 489         if (backlog > sk->sk_max_ack_backlog)
 490                 wake_up_interruptible_all(&u->peer_wait);
 491         sk->sk_max_ack_backlog  = backlog;
 492         sk->sk_state            = TCP_LISTEN;
 493         /* set credentials so connect can copy them */
 494         sk->sk_peercred.pid     = task_tgid_vnr(current);
 495         sk->sk_peercred.uid     = current->euid;
 496         sk->sk_peercred.gid     = current->egid;
 497         err = 0;
 498
 499 out_unlock:
 500         unix_state_unlock(sk);
 501 out:
 502         return err;
 503 }
 504
 505 static int unix_release(struct socket *);
 506 static int unix_bind(struct socket *, struct sockaddr *, int);
 507 static int unix_stream_connect(struct socket *, struct sockaddr *,
 508                                int addr_len, int flags);
 509 static int unix_socketpair(struct socket *, struct socket *);
 510 static int unix_accept(struct socket *, struct socket *, int);
 511 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
 512 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
 513 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
 514 static int unix_shutdown(struct socket *, int);
 515 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
 516                                struct msghdr *, size_t);
 517 static int unix_stream_recvmsg(struct kiocb *, struct socket *,
 518                                struct msghdr *, size_t, int);
 519 static int unix_dgram_sendmsg(struct kiocb *, struct socket *,
 520                               struct msghdr *, size_t);
 521 static int unix_dgram_recvmsg(struct kiocb *, struct socket *,
 522                               struct msghdr *, size_t, int);
 523 static int unix_dgram_connect(struct socket *, struct sockaddr *,
 524                               int, int);
 525 static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
 526                                   struct msghdr *, size_t);
 527
 528 static const struct proto_ops unix_stream_ops = {
 529         .family =       PF_UNIX,
 530         .owner =        THIS_MODULE,
 531         .release =      unix_release,
 532         .bind =         unix_bind,
 533         .connect =      unix_stream_connect,
 534         .socketpair =   unix_socketpair,
 535         .accept =       unix_accept,
 536         .getname =      unix_getname,
 537         .poll =         unix_poll,
 538         .ioctl =        unix_ioctl,
 539         .listen =       unix_listen,
 540         .shutdown =     unix_shutdown,
 541         .setsockopt =   sock_no_setsockopt,
 542         .getsockopt =   sock_no_getsockopt,
 543         .sendmsg =      unix_stream_sendmsg,
 544         .recvmsg =      unix_stream_recvmsg,
 545         .mmap =         sock_no_mmap,
 546         .sendpage =     sock_no_sendpage,
 547 };
 548
 549 static const struct proto_ops unix_dgram_ops = {
 550         .family =       PF_UNIX,
 551         .owner =        THIS_MODULE,
 552         .release =      unix_release,
 553         .bind =         unix_bind,
 554         .connect =      unix_dgram_connect,
 555         .socketpair =   unix_socketpair,
 556         .accept =       sock_no_accept,
 557         .getname =      unix_getname,
 558         .poll =         datagram_poll,
 559         .ioctl =        unix_ioctl,
 560         .listen =       sock_no_listen,
 561         .shutdown =     unix_shutdown,
 562         .setsockopt =   sock_no_setsockopt,
 563         .getsockopt =   sock_no_getsockopt,
 564         .sendmsg =      unix_dgram_sendmsg,
 565         .recvmsg =      unix_dgram_recvmsg,
 566         .mmap =         sock_no_mmap,
 567         .sendpage =     sock_no_sendpage,
 568 };
 569
 570 static const struct proto_ops unix_seqpacket_ops = {
 571         .family =       PF_UNIX,
 572         .owner =        THIS_MODULE,
 573         .release =      unix_release,
 574         .bind =         unix_bind,
 575         .connect =      unix_stream_connect,
 576         .socketpair =   unix_socketpair,
 577         .accept =       unix_accept,
 578         .getname =      unix_getname,
 579         .poll =         datagram_poll,
 580         .ioctl =        unix_ioctl,
 581         .listen =       unix_listen,
 582         .shutdown =     unix_shutdown,
 583         .setsockopt =   sock_no_setsockopt,
 584         .getsockopt =   sock_no_getsockopt,
 585         .sendmsg =      unix_seqpacket_sendmsg,
 586         .recvmsg =      unix_dgram_recvmsg,
 587         .mmap =         sock_no_mmap,
 588         .sendpage =     sock_no_sendpage,
 589 };
 590
 591 static struct proto unix_proto = {
 592         .name     = "UNIX",
 593         .owner    = THIS_MODULE,
 594         .obj_size = sizeof(struct unix_sock),
 595 };
 596
 597 /*
 598  * AF_UNIX sockets do not interact with hardware, hence they
 599  * dont trigger interrupts - so it's safe for them to have
 600  * bh-unsafe locking for their sk_receive_queue.lock. Split off
 601  * this special lock-class by reinitializing the spinlock key:
 602  */
 603 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
 604
 605 static struct sock * unix_create1(struct net *net, struct socket *sock)
 606 {
 607         struct sock *sk = NULL;
 608         struct unix_sock *u;
 609
 610         atomic_inc(&unix_nr_socks);
 611         if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
 612                 goto out;
 613
 614         sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
 615         if (!sk)
 616                 goto out;
 617
 618         sock_init_data(sock,sk);
 619         lockdep_set_class(&sk->sk_receive_queue.lock,
 620                                 &af_unix_sk_receive_queue_lock_key);
 621
 622         sk->sk_write_space      = unix_write_space;
 623         sk->sk_max_ack_backlog  = sysctl_unix_max_dgram_qlen;
 624         sk->sk_destruct         = unix_sock_destructor;
 625         u         = unix_sk(sk);
 626         u->dentry = NULL;
 627         u->mnt    = NULL;
 628         spin_lock_init(&u->lock);
 629         atomic_set(&u->inflight, 0);
 630         INIT_LIST_HEAD(&u->link);
 631         mutex_init(&u->readlock); /* single task reading lock */
 632         init_waitqueue_head(&u->peer_wait);
 633         unix_insert_socket(unix_sockets_unbound, sk);
 634 out:
 635         if (sk == NULL)
 636                 atomic_dec(&unix_nr_socks);
 637         return sk;
 638 }
 639
 640 static int unix_create(struct net *net, struct socket *sock, int protocol)
 641 {
 642         if (protocol && protocol != PF_UNIX)
 643                 return -EPROTONOSUPPORT;
 644
 645         sock->state = SS_UNCONNECTED;
 646
 647         switch (sock->type) {
 648         case SOCK_STREAM:
 649                 sock->ops = &unix_stream_ops;
 650                 break;
 651                 /*
 652                  *      Believe it or not BSD has AF_UNIX, SOCK_RAW though
 653                  *      nothing uses it.
 654                  */
 655         case SOCK_RAW:
 656                 sock->type=SOCK_DGRAM;
 657         case SOCK_DGRAM:
 658                 sock->ops = &unix_dgram_ops;
 659                 break;
 660         case SOCK_SEQPACKET:
 661                 sock->ops = &unix_seqpacket_ops;
 662                 break;
 663         default:
 664                 return -ESOCKTNOSUPPORT;
 665         }
 666
 667         return unix_create1(net, sock) ? 0 : -ENOMEM;
 668 }
 669
 670 static int unix_release(struct socket *sock)
 671 {
 672         struct sock *sk = sock->sk;
 673
 674         if (!sk)
 675                 return 0;
 676
 677         sock->sk = NULL;
 678
 679         return unix_release_sock (sk, 0);
 680 }
 681
 682 static int unix_autobind(struct socket *sock)
 683 {
 684         struct sock *sk = sock->sk;
 685         struct net *net = sk->sk_net;
 686         struct unix_sock *u = unix_sk(sk);
 687         static u32 ordernum = 1;
 688         struct unix_address * addr;
 689         int err;
 690
 691         mutex_lock(&u->readlock);
 692
 693         err = 0;
 694         if (u->addr)
 695                 goto out;
 696
 697         err = -ENOMEM;
 698         addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
 699         if (!addr)
 700                 goto out;
 701
 702         addr->name->sun_family = AF_UNIX;
 703         atomic_set(&addr->refcnt, 1);
 704
 705 retry:
 706         addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
 707         addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
 708
 709         spin_lock(&unix_table_lock);
 710         ordernum = (ordernum+1)&0xFFFFF;
 711
 712         if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
 713                                       addr->hash)) {
 714                 spin_unlock(&unix_table_lock);
 715                 /* Sanity yield. It is unusual case, but yet... */
 716                 if (!(ordernum&0xFF))
 717                         yield();
 718                 goto retry;
 719         }
 720         addr->hash ^= sk->sk_type;
 721
 722         __unix_remove_socket(sk);
 723         u->addr = addr;
 724         __unix_insert_socket(&unix_socket_table[addr->hash], sk);
 725         spin_unlock(&unix_table_lock);
 726         err = 0;
 727
 728 out:    mutex_unlock(&u->readlock);
 729         return err;
 730 }
 731
 732 static struct sock *unix_find_other(struct net *net,
 733                                     struct sockaddr_un *sunname, int len,
 734                                     int type, unsigned hash, int *error)
 735 {
 736         struct sock *u;
 737         struct nameidata nd;
 738         int err = 0;
 739
 740         if (sunname->sun_path[0]) {
 741                 err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
 742                 if (err)
 743                         goto fail;
 744                 err = vfs_permission(&nd, MAY_WRITE);
 745                 if (err)
 746                         goto put_fail;
 747
 748                 err = -ECONNREFUSED;
 749                 if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
 750                         goto put_fail;
 751                 u=unix_find_socket_byinode(net, nd.dentry->d_inode);
 752                 if (!u)
 753                         goto put_fail;
 754
 755                 if (u->sk_type == type)
 756                         touch_atime(nd.mnt, nd.dentry);
 757
 758                 path_release(&nd);
 759
 760                 err=-EPROTOTYPE;
 761                 if (u->sk_type != type) {
 762                         sock_put(u);
 763                         goto fail;
 764                 }
 765         } else {
 766                 err = -ECONNREFUSED;
 767                 u=unix_find_socket_byname(net, sunname, len, type, hash);
 768                 if (u) {
 769                         struct dentry *dentry;
 770                         dentry = unix_sk(u)->dentry;
 771                         if (dentry)
 772                                 touch_atime(unix_sk(u)->mnt, dentry);
 773                 } else
 774                         goto fail;
 775         }
 776         return u;
 777
 778 put_fail:
 779         path_release(&nd);
 780 fail:
 781         *error=err;
 782         return NULL;
 783 }
 784
 785
 786 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 787 {
 788         struct sock *sk = sock->sk;
 789         struct net *net = sk->sk_net;
 790         struct unix_sock *u = unix_sk(sk);
 791         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
 792         struct dentry * dentry = NULL;
 793         struct nameidata nd;
 794         int err;
 795         unsigned hash;
 796         struct unix_address *addr;
 797         struct hlist_head *list;
 798
 799         err = -EINVAL;
 800         if (sunaddr->sun_family != AF_UNIX)
 801                 goto out;
 802
 803         if (addr_len==sizeof(short)) {
 804                 err = unix_autobind(sock);
 805                 goto out;
 806         }
 807
 808         err = unix_mkname(sunaddr, addr_len, &hash);
 809         if (err < 0)
 810                 goto out;
 811         addr_len = err;
 812
 813         mutex_lock(&u->readlock);
 814
 815         err = -EINVAL;
 816         if (u->addr)
 817                 goto out_up;
 818
 819         err = -ENOMEM;
 820         addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
 821         if (!addr)
 822                 goto out_up;
 823
 824         memcpy(addr->name, sunaddr, addr_len);
 825         addr->len = addr_len;
 826         addr->hash = hash ^ sk->sk_type;
 827         atomic_set(&addr->refcnt, 1);
 828
 829         if (sunaddr->sun_path[0]) {
 830                 unsigned int mode;
 831                 err = 0;
 832                 /*
 833                  * Get the parent directory, calculate the hash for last
 834                  * component.
 835                  */
 836                 err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd);
 837                 if (err)
 838                         goto out_mknod_parent;
 839
 840                 dentry = lookup_create(&nd, 0);
 841                 err = PTR_ERR(dentry);
 842                 if (IS_ERR(dentry))
 843                         goto out_mknod_unlock;
 844
 845                 /*
 846                  * All right, let's create it.
 847                  */
 848                 mode = S_IFSOCK |
 849                        (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
 850                 err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
 851                 if (err)
 852                         goto out_mknod_dput;
 853                 mutex_unlock(&nd.dentry->d_inode->i_mutex);
 854                 dput(nd.dentry);
 855                 nd.dentry = dentry;
 856
 857                 addr->hash = UNIX_HASH_SIZE;
 858         }
 859
 860         spin_lock(&unix_table_lock);
 861
 862         if (!sunaddr->sun_path[0]) {
 863                 err = -EADDRINUSE;
 864                 if (__unix_find_socket_byname(net, sunaddr, addr_len,
 865                                               sk->sk_type, hash)) {
 866                         unix_release_addr(addr);
 867                         goto out_unlock;
 868                 }
 869
 870                 list = &unix_socket_table[addr->hash];
 871         } else {
 872                 list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
 873                 u->dentry = nd.dentry;
 874                 u->mnt    = nd.mnt;
 875         }
 876
 877         err = 0;
 878         __unix_remove_socket(sk);
 879         u->addr = addr;
 880         __unix_insert_socket(list, sk);
 881
 882 out_unlock:
 883         spin_unlock(&unix_table_lock);
 884 out_up:
 885         mutex_unlock(&u->readlock);
 886 out:
 887         return err;
 888
 889 out_mknod_dput:
 890         dput(dentry);
 891 out_mknod_unlock:
 892         mutex_unlock(&nd.dentry->d_inode->i_mutex);
 893         path_release(&nd);
 894 out_mknod_parent:
 895         if (err==-EEXIST)
 896                 err=-EADDRINUSE;
 897         unix_release_addr(addr);
 898         goto out_up;
 899 }
 900
 901 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
 902 {
 903         if (unlikely(sk1 == sk2) || !sk2) {
 904                 unix_state_lock(sk1);
 905                 return;
 906         }
 907         if (sk1 < sk2) {
 908                 unix_state_lock(sk1);
 909                 unix_state_lock_nested(sk2);
 910         } else {
 911                 unix_state_lock(sk2);
 912                 unix_state_lock_nested(sk1);
 913         }
 914 }
 915
 916 static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
 917 {
 918         if (unlikely(sk1 == sk2) || !sk2) {
 919                 unix_state_unlock(sk1);
 920                 return;
 921         }
 922         unix_state_unlock(sk1);
 923         unix_state_unlock(sk2);
 924 }
 925
 926 static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 927                               int alen, int flags)
 928 {
 929         struct sock *sk = sock->sk;
 930         struct net *net = sk->sk_net;
 931         struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
 932         struct sock *other;
 933         unsigned hash;
 934         int err;
 935
 936         if (addr->sa_family != AF_UNSPEC) {
 937                 err = unix_mkname(sunaddr, alen, &hash);
 938                 if (err < 0)
 939                         goto out;
 940                 alen = err;
 941
 942                 if (test_bit(SOCK_PASSCRED, &sock->flags) &&
 943                     !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
 944                         goto out;
 945
 946 restart:
 947                 other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
 948                 if (!other)
 949                         goto out;
 950
 951                 unix_state_double_lock(sk, other);
 952
 953                 /* Apparently VFS overslept socket death. Retry. */
 954                 if (sock_flag(other, SOCK_DEAD)) {
 955                         unix_state_double_unlock(sk, other);
 956                         sock_put(other);
 957                         goto restart;
 958                 }
 959
 960                 err = -EPERM;
 961                 if (!unix_may_send(sk, other))
 962                         goto out_unlock;
 963
 964                 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
 965                 if (err)
 966                         goto out_unlock;
 967
 968         } else {
 969                 /*
 970                  *      1003.1g breaking connected state with AF_UNSPEC
 971                  */
 972                 other = NULL;
 973                 unix_state_double_lock(sk, other);
 974         }
 975
 976         /*
 977          * If it was connected, reconnect.
 978          */
 979         if (unix_peer(sk)) {
 980                 struct sock *old_peer = unix_peer(sk);
 981                 unix_peer(sk)=other;
 982                 unix_state_double_unlock(sk, other);
 983
 984                 if (other != old_peer)
 985                         unix_dgram_disconnected(sk, old_peer);
 986                 sock_put(old_peer);
 987         } else {
 988                 unix_peer(sk)=other;
 989                 unix_state_double_unlock(sk, other);
 990         }
 991         return 0;
 992
 993 out_unlock:
 994         unix_state_double_unlock(sk, other);
 995         sock_put(other);
 996 out:
 997         return err;
 998 }
 999
1000 static long unix_wait_for_peer(struct sock *other, long timeo)
1001 {
1002         struct unix_sock *u = unix_sk(other);
1003         int sched;
1004         DEFINE_WAIT(wait);
1005
1006         prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE);
1007
1008         sched = !sock_flag(other, SOCK_DEAD) &&
1009                 !(other->sk_shutdown & RCV_SHUTDOWN) &&
1010                 (skb_queue_len(&other->sk_receive_queue) >
1011                  other->sk_max_ack_backlog);
1012
1013         unix_state_unlock(other);
1014
1015         if (sched)
1016                 timeo = schedule_timeout(timeo);
1017
1018         finish_wait(&u->peer_wait, &wait);
1019         return timeo;
1020 }
1021
1022 static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
1023                                int addr_len, int flags)
1024 {
1025         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1026         struct sock *sk = sock->sk;
1027         struct net *net = sk->sk_net;
1028         struct unix_sock *u = unix_sk(sk), *newu, *otheru;
1029         struct sock *newsk = NULL;
1030         struct sock *other = NULL;
1031         struct sk_buff *skb = NULL;
1032         unsigned hash;
1033         int st;
1034         int err;
1035         long timeo;
1036
1037         err = unix_mkname(sunaddr, addr_len, &hash);
1038         if (err < 0)
1039                 goto out;
1040         addr_len = err;
1041
1042         if (test_bit(SOCK_PASSCRED, &sock->flags)
1043                 && !u->addr && (err = unix_autobind(sock)) != 0)
1044                 goto out;
1045
1046         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
1047
1048         /* First of all allocate resources.
1049            If we will make it after state is locked,
1050            we will have to recheck all again in any case.
1051          */
1052
1053         err = -ENOMEM;
1054
1055         /* create new sock for complete connection */
1056         newsk = unix_create1(sk->sk_net, NULL);
1057         if (newsk == NULL)
1058                 goto out;
1059
1060         /* Allocate skb for sending to listening sock */
1061         skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
1062         if (skb == NULL)
1063                 goto out;
1064
1065 restart:
1066         /*  Find listening sock. */
1067         other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
1068         if (!other)
1069                 goto out;
1070
1071         /* Latch state of peer */
1072         unix_state_lock(other);
1073
1074         /* Apparently VFS overslept socket death. Retry. */
1075         if (sock_flag(other, SOCK_DEAD)) {
1076                 unix_state_unlock(other);
1077                 sock_put(other);
1078                 goto restart;
1079         }
1080
1081         err = -ECONNREFUSED;
1082         if (other->sk_state != TCP_LISTEN)
1083                 goto out_unlock;
1084
1085         if (skb_queue_len(&other->sk_receive_queue) >
1086             other->sk_max_ack_backlog) {
1087                 err = -EAGAIN;
1088                 if (!timeo)
1089                         goto out_unlock;
1090
1091                 timeo = unix_wait_for_peer(other, timeo);
1092
1093                 err = sock_intr_errno(timeo);
1094                 if (signal_pending(current))
1095                         goto out;
1096                 sock_put(other);
1097                 goto restart;
1098         }
1099
1100         /* Latch our state.
1101
1102            It is tricky place. We need to grab write lock and cannot
1103            drop lock on peer. It is dangerous because deadlock is
1104            possible. Connect to self case and simultaneous
1105            attempt to connect are eliminated by checking socket
1106            state. other is TCP_LISTEN, if sk is TCP_LISTEN we
1107            check this before attempt to grab lock.
1108
1109            Well, and we have to recheck the state after socket locked.
1110          */
1111         st = sk->sk_state;
1112
1113         switch (st) {
1114         case TCP_CLOSE:
1115                 /* This is ok... continue with connect */
1116                 break;
1117         case TCP_ESTABLISHED:
1118                 /* Socket is already connected */
1119                 err = -EISCONN;
1120                 goto out_unlock;
1121         default:
1122                 err = -EINVAL;
1123                 goto out_unlock;
1124         }
1125
1126         unix_state_lock_nested(sk);
1127
1128         if (sk->sk_state != st) {
1129                 unix_state_unlock(sk);
1130                 unix_state_unlock(other);
1131                 sock_put(other);
1132                 goto restart;
1133         }
1134
1135         err = security_unix_stream_connect(sock, other->sk_socket, newsk);
1136         if (err) {
1137                 unix_state_unlock(sk);
1138                 goto out_unlock;
1139         }
1140
1141         /* The way is open! Fastly set all the necessary fields... */
1142
1143         sock_hold(sk);
1144         unix_peer(newsk)        = sk;
1145         newsk->sk_state         = TCP_ESTABLISHED;
1146         newsk->sk_type          = sk->sk_type;
1147         newsk->sk_peercred.pid  = task_tgid_vnr(current);
1148         newsk->sk_peercred.uid  = current->euid;
1149         newsk->sk_peercred.gid  = current->egid;
1150         newu = unix_sk(newsk);
1151         newsk->sk_sleep         = &newu->peer_wait;
1152         otheru = unix_sk(other);
1153
1154         /* copy address information from listening to new sock*/
1155         if (otheru->addr) {
1156                 atomic_inc(&otheru->addr->refcnt);
1157                 newu->addr = otheru->addr;
1158         }
1159         if (otheru->dentry) {
1160                 newu->dentry    = dget(otheru->dentry);
1161                 newu->mnt       = mntget(otheru->mnt);
1162         }
1163
1164         /* Set credentials */
1165         sk->sk_peercred = other->sk_peercred;
1166
1167         sock->state     = SS_CONNECTED;
1168         sk->sk_state    = TCP_ESTABLISHED;
1169         sock_hold(newsk);
1170
1171         smp_mb__after_atomic_inc();     /* sock_hold() does an atomic_inc() */
1172         unix_peer(sk)   = newsk;
1173
1174         unix_state_unlock(sk);
1175
1176         /* take ten and and send info to listening sock */
1177         spin_lock(&other->sk_receive_queue.lock);
1178         __skb_queue_tail(&other->sk_receive_queue, skb);
1179         spin_unlock(&other->sk_receive_queue.lock);
1180         unix_state_unlock(other);
1181         other->sk_data_ready(other, 0);
1182         sock_put(other);
1183         return 0;
1184
1185 out_unlock:
1186         if (other)
1187                 unix_state_unlock(other);
1188
1189 out:
1190         if (skb)
1191                 kfree_skb(skb);
1192         if (newsk)
1193                 unix_release_sock(newsk, 0);
1194         if (other)
1195                 sock_put(other);
1196         return err;
1197 }
1198
1199 static int unix_socketpair(struct socket *socka, struct socket *sockb)
1200 {
1201         struct sock *ska=socka->sk, *skb = sockb->sk;
1202
1203         /* Join our sockets back to back */
1204         sock_hold(ska);
1205         sock_hold(skb);
1206         unix_peer(ska)=skb;
1207         unix_peer(skb)=ska;
1208         ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
1209         ska->sk_peercred.uid = skb->sk_peercred.uid = current->euid;
1210         ska->sk_peercred.gid = skb->sk_peercred.gid = current->egid;
1211
1212         if (ska->sk_type != SOCK_DGRAM) {
1213                 ska->sk_state = TCP_ESTABLISHED;
1214                 skb->sk_state = TCP_ESTABLISHED;
1215                 socka->state  = SS_CONNECTED;
1216                 sockb->state  = SS_CONNECTED;
1217         }
1218         return 0;
1219 }
1220
1221 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
1222 {
1223         struct sock *sk = sock->sk;
1224         struct sock *tsk;
1225         struct sk_buff *skb;
1226         int err;
1227
1228         err = -EOPNOTSUPP;
1229         if (sock->type!=SOCK_STREAM && sock->type!=SOCK_SEQPACKET)
1230                 goto out;
1231
1232         err = -EINVAL;
1233         if (sk->sk_state != TCP_LISTEN)
1234                 goto out;
1235
1236         /* If socket state is TCP_LISTEN it cannot change (for now...),
1237          * so that no locks are necessary.
1238          */
1239
1240         skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
1241         if (!skb) {
1242                 /* This means receive shutdown. */
1243                 if (err == 0)
1244                         err = -EINVAL;
1245                 goto out;
1246         }
1247
1248         tsk = skb->sk;
1249         skb_free_datagram(sk, skb);
1250         wake_up_interruptible(&unix_sk(sk)->peer_wait);
1251
1252         /* attach accepted sock to socket */
1253         unix_state_lock(tsk);
1254         newsock->state = SS_CONNECTED;
1255         sock_graft(tsk, newsock);
1256         unix_state_unlock(tsk);
1257         return 0;
1258
1259 out:
1260         return err;
1261 }
1262
1263
1264 static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
1265 {
1266         struct sock *sk = sock->sk;
1267         struct unix_sock *u;
1268         struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
1269         int err = 0;
1270
1271         if (peer) {
1272                 sk = unix_peer_get(sk);
1273
1274                 err = -ENOTCONN;
1275                 if (!sk)
1276                         goto out;
1277                 err = 0;
1278         } else {
1279                 sock_hold(sk);
1280         }
1281
1282         u = unix_sk(sk);
1283         unix_state_lock(sk);
1284         if (!u->addr) {
1285                 sunaddr->sun_family = AF_UNIX;
1286                 sunaddr->sun_path[0] = 0;
1287                 *uaddr_len = sizeof(short);
1288         } else {
1289                 struct unix_address *addr = u->addr;
1290
1291                 *uaddr_len = addr->len;
1292                 memcpy(sunaddr, addr->name, *uaddr_len);
1293         }
1294         unix_state_unlock(sk);
1295         sock_put(sk);
1296 out:
1297         return err;
1298 }
1299
1300 static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1301 {
1302         int i;
1303
1304         scm->fp = UNIXCB(skb).fp;
1305         skb->destructor = sock_wfree;
1306         UNIXCB(skb).fp = NULL;
1307
1308         for (i=scm->fp->count-1; i>=0; i--)
1309                 unix_notinflight(scm->fp->fp[i]);
1310 }
1311
1312 static void unix_destruct_fds(struct sk_buff *skb)
1313 {
1314         struct scm_cookie scm;
1315         memset(&scm, 0, sizeof(scm));
1316         unix_detach_fds(&scm, skb);
1317
1318         /* Alas, it calls VFS */
1319         /* So fscking what? fput() had been SMP-safe since the last Summer */
1320         scm_destroy(&scm);
1321         sock_wfree(skb);
1322 }
1323
1324 static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
1325 {
1326         int i;
1327         for (i=scm->fp->count-1; i>=0; i--)
1328                 unix_inflight(scm->fp->fp[i]);
1329         UNIXCB(skb).fp = scm->fp;
1330         skb->destructor = unix_destruct_fds;
1331         scm->fp = NULL;
1332 }
1333
1334 /*
1335  *      Send AF_UNIX data.
1336  */
1337
1338 static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
1339                               struct msghdr *msg, size_t len)
1340 {
1341         struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1342         struct sock *sk = sock->sk;
1343         struct net *net = sk->sk_net;
1344         struct unix_sock *u = unix_sk(sk);
1345         struct sockaddr_un *sunaddr=msg->msg_name;
1346         struct sock *other = NULL;
1347         int namelen = 0; /* fake GCC */
1348         int err;
1349         unsigned hash;
1350         struct sk_buff *skb;
1351         long timeo;
1352         struct scm_cookie tmp_scm;
1353
1354         if (NULL == siocb->scm)
1355                 siocb->scm = &tmp_scm;
1356         err = scm_send(sock, msg, siocb->scm);
1357         if (err < 0)
1358                 return err;
1359
1360         err = -EOPNOTSUPP;
1361         if (msg->msg_flags&MSG_OOB)
1362                 goto out;
1363
1364         if (msg->msg_namelen) {
1365                 err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
1366                 if (err < 0)
1367                         goto out;
1368                 namelen = err;
1369         } else {
1370                 sunaddr = NULL;
1371                 err = -ENOTCONN;
1372                 other = unix_peer_get(sk);
1373                 if (!other)
1374                         goto out;
1375         }
1376
1377         if (test_bit(SOCK_PASSCRED, &sock->flags)
1378                 && !u->addr && (err = unix_autobind(sock)) != 0)
1379                 goto out;
1380
1381         err = -EMSGSIZE;
1382         if (len > sk->sk_sndbuf - 32)
1383                 goto out;
1384
1385         skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err);
1386         if (skb==NULL)
1387                 goto out;
1388
1389         memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1390         if (siocb->scm->fp)
1391                 unix_attach_fds(siocb->scm, skb);
1392         unix_get_secdata(siocb->scm, skb);
1393
1394         skb_reset_transport_header(skb);
1395         err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
1396         if (err)
1397                 goto out_free;
1398
1399         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1400
1401 restart:
1402         if (!other) {
1403                 err = -ECONNRESET;
1404                 if (sunaddr == NULL)
1405                         goto out_free;
1406
1407                 other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
1408                                         hash, &err);
1409                 if (other==NULL)
1410                         goto out_free;
1411         }
1412
1413         unix_state_lock(other);
1414         err = -EPERM;
1415         if (!unix_may_send(sk, other))
1416                 goto out_unlock;
1417
1418         if (sock_flag(other, SOCK_DEAD)) {
1419                 /*
1420                  *      Check with 1003.1g - what should
1421                  *      datagram error
1422                  */
1423                 unix_state_unlock(other);
1424                 sock_put(other);
1425
1426                 err = 0;
1427                 unix_state_lock(sk);
1428                 if (unix_peer(sk) == other) {
1429                         unix_peer(sk)=NULL;
1430                         unix_state_unlock(sk);
1431
1432                         unix_dgram_disconnected(sk, other);
1433                         sock_put(other);
1434                         err = -ECONNREFUSED;
1435                 } else {
1436                         unix_state_unlock(sk);
1437                 }
1438
1439                 other = NULL;
1440                 if (err)
1441                         goto out_free;
1442                 goto restart;
1443         }
1444
1445         err = -EPIPE;
1446         if (other->sk_shutdown & RCV_SHUTDOWN)
1447                 goto out_unlock;
1448
1449         if (sk->sk_type != SOCK_SEQPACKET) {
1450                 err = security_unix_may_send(sk->sk_socket, other->sk_socket);
1451                 if (err)
1452                         goto out_unlock;
1453         }
1454
1455         if (unix_peer(other) != sk &&
1456             (skb_queue_len(&other->sk_receive_queue) >
1457              other->sk_max_ack_backlog)) {
1458                 if (!timeo) {
1459                         err = -EAGAIN;
1460                         goto out_unlock;
1461                 }
1462
1463                 timeo = unix_wait_for_peer(other, timeo);
1464
1465                 err = sock_intr_errno(timeo);
1466                 if (signal_pending(current))
1467                         goto out_free;
1468
1469                 goto restart;
1470         }
1471
1472         skb_queue_tail(&other->sk_receive_queue, skb);
1473         unix_state_unlock(other);
1474         other->sk_data_ready(other, len);
1475         sock_put(other);
1476         scm_destroy(siocb->scm);
1477         return len;
1478
1479 out_unlock:
1480         unix_state_unlock(other);
1481 out_free:
1482         kfree_skb(skb);
1483 out:
1484         if (other)
1485                 sock_put(other);
1486         scm_destroy(siocb->scm);
1487         return err;
1488 }
1489
1490
1491 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1492                                struct msghdr *msg, size_t len)
1493 {
1494         struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1495         struct sock *sk = sock->sk;
1496         struct sock *other = NULL;
1497         struct sockaddr_un *sunaddr=msg->msg_name;
1498         int err,size;
1499         struct sk_buff *skb;
1500         int sent=0;
1501         struct scm_cookie tmp_scm;
1502
1503         if (NULL == siocb->scm)
1504                 siocb->scm = &tmp_scm;
1505         err = scm_send(sock, msg, siocb->scm);
1506         if (err < 0)
1507                 return err;
1508
1509         err = -EOPNOTSUPP;
1510         if (msg->msg_flags&MSG_OOB)
1511                 goto out_err;
1512
1513         if (msg->msg_namelen) {
1514                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1515                 goto out_err;
1516         } else {
1517                 sunaddr = NULL;
1518                 err = -ENOTCONN;
1519                 other = unix_peer(sk);
1520                 if (!other)
1521                         goto out_err;
1522         }
1523
1524         if (sk->sk_shutdown & SEND_SHUTDOWN)
1525                 goto pipe_err;
1526
1527         while(sent < len)
1528         {
1529                 /*
1530                  *      Optimisation for the fact that under 0.01% of X
1531                  *      messages typically need breaking up.
1532                  */
1533
1534                 size = len-sent;
1535
1536                 /* Keep two messages in the pipe so it schedules better */
1537                 if (size > ((sk->sk_sndbuf >> 1) - 64))
1538                         size = (sk->sk_sndbuf >> 1) - 64;
1539
1540                 if (size > SKB_MAX_ALLOC)
1541                         size = SKB_MAX_ALLOC;
1542
1543                 /*
1544                  *      Grab a buffer
1545                  */
1546
1547                 skb=sock_alloc_send_skb(sk,size,msg->msg_flags&MSG_DONTWAIT, &err);
1548
1549                 if (skb==NULL)
1550                         goto out_err;
1551
1552                 /*
1553                  *      If you pass two values to the sock_alloc_send_skb
1554                  *      it tries to grab the large buffer with GFP_NOFS
1555                  *      (which can fail easily), and if it fails grab the
1556                  *      fallback size buffer which is under a page and will
1557                  *      succeed. [Alan]
1558                  */
1559                 size = min_t(int, size, skb_tailroom(skb));
1560
1561                 memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1562                 if (siocb->scm->fp)
1563                         unix_attach_fds(siocb->scm, skb);
1564
1565                 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
1566                         kfree_skb(skb);
1567                         goto out_err;
1568                 }
1569
1570                 unix_state_lock(other);
1571
1572                 if (sock_flag(other, SOCK_DEAD) ||
1573                     (other->sk_shutdown & RCV_SHUTDOWN))
1574                         goto pipe_err_free;
1575
1576                 skb_queue_tail(&other->sk_receive_queue, skb);
1577                 unix_state_unlock(other);
1578                 other->sk_data_ready(other, size);
1579                 sent+=size;
1580         }
1581
1582         scm_destroy(siocb->scm);
1583         siocb->scm = NULL;
1584
1585         return sent;
1586
1587 pipe_err_free:
1588         unix_state_unlock(other);
1589         kfree_skb(skb);
1590 pipe_err:
1591         if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
1592                 send_sig(SIGPIPE,current,0);
1593         err = -EPIPE;
1594 out_err:
1595         scm_destroy(siocb->scm);
1596         siocb->scm = NULL;
1597         return sent ? : err;
1598 }
1599
1600 static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
1601                                   struct msghdr *msg, size_t len)
1602 {
1603         int err;
1604         struct sock *sk = sock->sk;
1605
1606         err = sock_error(sk);
1607         if (err)
1608                 return err;
1609
1610         if (sk->sk_state != TCP_ESTABLISHED)
1611                 return -ENOTCONN;
1612
1613         if (msg->msg_namelen)
1614                 msg->msg_namelen = 0;
1615
1616         return unix_dgram_sendmsg(kiocb, sock, msg, len);
1617 }
1618
1619 static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
1620 {
1621         struct unix_sock *u = unix_sk(sk);
1622
1623         msg->msg_namelen = 0;
1624         if (u->addr) {
1625                 msg->msg_namelen = u->addr->len;
1626                 memcpy(msg->msg_name, u->addr->name, u->addr->len);
1627         }
1628 }
1629
1630 static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
1631                               struct msghdr *msg, size_t size,
1632                               int flags)
1633 {
1634         struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1635         struct scm_cookie tmp_scm;
1636         struct sock *sk = sock->sk;
1637         struct unix_sock *u = unix_sk(sk);
1638         int noblock = flags & MSG_DONTWAIT;
1639         struct sk_buff *skb;
1640         int err;
1641
1642         err = -EOPNOTSUPP;
1643         if (flags&MSG_OOB)
1644                 goto out;
1645
1646         msg->msg_namelen = 0;
1647
1648         mutex_lock(&u->readlock);
1649
1650         skb = skb_recv_datagram(sk, flags, noblock, &err);
1651         if (!skb) {
1652                 unix_state_lock(sk);
1653                 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
1654                 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
1655                     (sk->sk_shutdown & RCV_SHUTDOWN))
1656                         err = 0;
1657                 unix_state_unlock(sk);
1658                 goto out_unlock;
1659         }
1660
1661         wake_up_interruptible_sync(&u->peer_wait);
1662
1663         if (msg->msg_name)
1664                 unix_copy_addr(msg, skb->sk);
1665
1666         if (size > skb->len)
1667                 size = skb->len;
1668         else if (size < skb->len)
1669                 msg->msg_flags |= MSG_TRUNC;
1670
1671         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
1672         if (err)
1673                 goto out_free;
1674
1675         if (!siocb->scm) {
1676                 siocb->scm = &tmp_scm;
1677                 memset(&tmp_scm, 0, sizeof(tmp_scm));
1678         }
1679         siocb->scm->creds = *UNIXCREDS(skb);
1680         unix_set_secdata(siocb->scm, skb);
1681
1682         if (!(flags & MSG_PEEK))
1683         {
1684                 if (UNIXCB(skb).fp)
1685                         unix_detach_fds(siocb->scm, skb);
1686         }
1687         else
1688         {
1689                 /* It is questionable: on PEEK we could:
1690                    - do not return fds - good, but too simple 8)
1691                    - return fds, and do not return them on read (old strategy,
1692                      apparently wrong)
1693                    - clone fds (I chose it for now, it is the most universal
1694                      solution)
1695
1696                    POSIX 1003.1g does not actually define this clearly
1697                    at all. POSIX 1003.1g doesn't define a lot of things
1698                    clearly however!
1699
1700                 */
1701                 if (UNIXCB(skb).fp)
1702                         siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1703         }
1704         err = size;
1705
1706         scm_recv(sock, msg, siocb->scm, flags);
1707
1708 out_free:
1709         skb_free_datagram(sk,skb);
1710 out_unlock:
1711         mutex_unlock(&u->readlock);
1712 out:
1713         return err;
1714 }
1715
1716 /*
1717  *      Sleep until data has arrive. But check for races..
1718  */
1719
1720 static long unix_stream_data_wait(struct sock * sk, long timeo)
1721 {
1722         DEFINE_WAIT(wait);
1723
1724         unix_state_lock(sk);
1725
1726         for (;;) {
1727                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1728
1729                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1730                     sk->sk_err ||
1731                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1732                     signal_pending(current) ||
1733                     !timeo)
1734                         break;
1735
1736                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1737                 unix_state_unlock(sk);
1738                 timeo = schedule_timeout(timeo);
1739                 unix_state_lock(sk);
1740                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1741         }
1742
1743         finish_wait(sk->sk_sleep, &wait);
1744         unix_state_unlock(sk);
1745         return timeo;
1746 }
1747
1748
1749
1750 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
1751                                struct msghdr *msg, size_t size,
1752                                int flags)
1753 {
1754         struct sock_iocb *siocb = kiocb_to_siocb(iocb);
1755         struct scm_cookie tmp_scm;
1756         struct sock *sk = sock->sk;
1757         struct unix_sock *u = unix_sk(sk);
1758         struct sockaddr_un *sunaddr=msg->msg_name;
1759         int copied = 0;
1760         int check_creds = 0;
1761         int target;
1762         int err = 0;
1763         long timeo;
1764
1765         err = -EINVAL;
1766         if (sk->sk_state != TCP_ESTABLISHED)
1767                 goto out;
1768
1769         err = -EOPNOTSUPP;
1770         if (flags&MSG_OOB)
1771                 goto out;
1772
1773         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
1774         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
1775
1776         msg->msg_namelen = 0;
1777
1778         /* Lock the socket to prevent queue disordering
1779          * while sleeps in memcpy_tomsg
1780          */
1781
1782         if (!siocb->scm) {
1783                 siocb->scm = &tmp_scm;
1784                 memset(&tmp_scm, 0, sizeof(tmp_scm));
1785         }
1786
1787         mutex_lock(&u->readlock);
1788
1789         do
1790         {
1791                 int chunk;
1792                 struct sk_buff *skb;
1793
1794                 unix_state_lock(sk);
1795                 skb = skb_dequeue(&sk->sk_receive_queue);
1796                 if (skb==NULL)
1797                 {
1798                         if (copied >= target)
1799                                 goto unlock;
1800
1801                         /*
1802                          *      POSIX 1003.1g mandates this order.
1803                          */
1804
1805                         if ((err = sock_error(sk)) != 0)
1806                                 goto unlock;
1807                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1808                                 goto unlock;
1809
1810                         unix_state_unlock(sk);
1811                         err = -EAGAIN;
1812                         if (!timeo)
1813                                 break;
1814                         mutex_unlock(&u->readlock);
1815
1816                         timeo = unix_stream_data_wait(sk, timeo);
1817
1818                         if (signal_pending(current)) {
1819                                 err = sock_intr_errno(timeo);
1820                                 goto out;
1821                         }
1822                         mutex_lock(&u->readlock);
1823                         continue;
1824  unlock:
1825                         unix_state_unlock(sk);
1826                         break;
1827                 }
1828                 unix_state_unlock(sk);
1829
1830                 if (check_creds) {
1831                         /* Never glue messages from different writers */
1832                         if (memcmp(UNIXCREDS(skb), &siocb->scm->creds, sizeof(siocb->scm->creds)) != 0) {
1833                                 skb_queue_head(&sk->sk_receive_queue, skb);
1834                                 break;
1835                         }
1836                 } else {
1837                         /* Copy credentials */
1838                         siocb->scm->creds = *UNIXCREDS(skb);
1839                         check_creds = 1;
1840                 }
1841
1842                 /* Copy address just once */
1843                 if (sunaddr)
1844                 {
1845                         unix_copy_addr(msg, skb->sk);
1846                         sunaddr = NULL;
1847                 }
1848
1849                 chunk = min_t(unsigned int, skb->len, size);
1850                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
1851                         skb_queue_head(&sk->sk_receive_queue, skb);
1852                         if (copied == 0)
1853                                 copied = -EFAULT;
1854                         break;
1855                 }
1856                 copied += chunk;
1857                 size -= chunk;
1858
1859                 /* Mark read part of skb as used */
1860                 if (!(flags & MSG_PEEK))
1861                 {
1862                         skb_pull(skb, chunk);
1863
1864                         if (UNIXCB(skb).fp)
1865                                 unix_detach_fds(siocb->scm, skb);
1866
1867                         /* put the skb back if we didn't use it up.. */
1868                         if (skb->len)
1869                         {
1870                                 skb_queue_head(&sk->sk_receive_queue, skb);
1871                                 break;
1872                         }
1873
1874                         kfree_skb(skb);
1875
1876                         if (siocb->scm->fp)
1877                                 break;
1878                 }
1879                 else
1880                 {
1881                         /* It is questionable, see note in unix_dgram_recvmsg.
1882                          */
1883                         if (UNIXCB(skb).fp)
1884                                 siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
1885
1886                         /* put message back and return */
1887                         skb_queue_head(&sk->sk_receive_queue, skb);
1888                         break;
1889                 }
1890         } while (size);
1891
1892         mutex_unlock(&u->readlock);
1893         scm_recv(sock, msg, siocb->scm, flags);
1894 out:
1895         return copied ? : err;
1896 }
1897
1898 static int unix_shutdown(struct socket *sock, int mode)
1899 {
1900         struct sock *sk = sock->sk;
1901         struct sock *other;
1902
1903         mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
1904
1905         if (mode) {
1906                 unix_state_lock(sk);
1907                 sk->sk_shutdown |= mode;
1908                 other=unix_peer(sk);
1909                 if (other)
1910                         sock_hold(other);
1911                 unix_state_unlock(sk);
1912                 sk->sk_state_change(sk);
1913
1914                 if (other &&
1915                         (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
1916
1917                         int peer_mode = 0;
1918
1919                         if (mode&RCV_SHUTDOWN)
1920                                 peer_mode |= SEND_SHUTDOWN;
1921                         if (mode&SEND_SHUTDOWN)
1922                                 peer_mode |= RCV_SHUTDOWN;
1923                         unix_state_lock(other);
1924                         other->sk_shutdown |= peer_mode;
1925                         unix_state_unlock(other);
1926                         other->sk_state_change(other);
1927                         read_lock(&other->sk_callback_lock);
1928                         if (peer_mode == SHUTDOWN_MASK)
1929                                 sk_wake_async(other,1,POLL_HUP);
1930                         else if (peer_mode & RCV_SHUTDOWN)
1931                                 sk_wake_async(other,1,POLL_IN);
1932                         read_unlock(&other->sk_callback_lock);
1933                 }
1934                 if (other)
1935                         sock_put(other);
1936         }
1937         return 0;
1938 }
1939
1940 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1941 {
1942         struct sock *sk = sock->sk;
1943         long amount=0;
1944         int err;
1945
1946         switch(cmd)
1947         {
1948                 case SIOCOUTQ:
1949                         amount = atomic_read(&sk->sk_wmem_alloc);
1950                         err = put_user(amount, (int __user *)arg);
1951                         break;
1952                 case SIOCINQ:
1953                 {
1954                         struct sk_buff *skb;
1955
1956                         if (sk->sk_state == TCP_LISTEN) {
1957                                 err = -EINVAL;
1958                                 break;
1959                         }
1960
1961                         spin_lock(&sk->sk_receive_queue.lock);
1962                         if (sk->sk_type == SOCK_STREAM ||
1963                             sk->sk_type == SOCK_SEQPACKET) {
1964                                 skb_queue_walk(&sk->sk_receive_queue, skb)
1965                                         amount += skb->len;
1966                         } else {
1967                                 skb = skb_peek(&sk->sk_receive_queue);
1968                                 if (skb)
1969                                         amount=skb->len;
1970                         }
1971                         spin_unlock(&sk->sk_receive_queue.lock);
1972                         err = put_user(amount, (int __user *)arg);
1973                         break;
1974                 }
1975
1976                 default:
1977                         err = -ENOIOCTLCMD;
1978                         break;
1979         }
1980         return err;
1981 }
1982
1983 static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
1984 {
1985         struct sock *sk = sock->sk;
1986         unsigned int mask;
1987
1988         poll_wait(file, sk->sk_sleep, wait);
1989         mask = 0;
1990
1991         /* exceptional events? */
1992         if (sk->sk_err)
1993                 mask |= POLLERR;
1994         if (sk->sk_shutdown == SHUTDOWN_MASK)
1995                 mask |= POLLHUP;
1996         if (sk->sk_shutdown & RCV_SHUTDOWN)
1997                 mask |= POLLRDHUP;
1998
1999         /* readable? */
2000         if (!skb_queue_empty(&sk->sk_receive_queue) ||
2001             (sk->sk_shutdown & RCV_SHUTDOWN))
2002                 mask |= POLLIN | POLLRDNORM;
2003
2004         /* Connection-based need to check for termination and startup */
2005         if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && sk->sk_state == TCP_CLOSE)
2006                 mask |= POLLHUP;
2007
2008         /*
2009          * we set writable also when the other side has shut down the
2010          * connection. This prevents stuck sockets.
2011          */
2012         if (unix_writable(sk))
2013                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
2014
2015         return mask;
2016 }
2017
2018
2019 #ifdef CONFIG_PROC_FS
2020 struct unix_iter_state {
2021         struct seq_net_private p;
2022         int i;
2023 };
2024 static struct sock *unix_seq_idx(struct unix_iter_state *iter, loff_t pos)
2025 {
2026         loff_t off = 0;
2027         struct sock *s;
2028
2029         for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
2030                 if (s->sk_net != iter->p.net)
2031                         continue;
2032                 if (off == pos)
2033                         return s;
2034                 ++off;
2035         }
2036         return NULL;
2037 }
2038
2039
2040 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
2041 {
2042         struct unix_iter_state *iter = seq->private;
2043         spin_lock(&unix_table_lock);
2044         return *pos ? unix_seq_idx(iter, *pos - 1) : ((void *) 1);
2045 }
2046
2047 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2048 {
2049         struct unix_iter_state *iter = seq->private;
2050         struct sock *sk = v;
2051         ++*pos;
2052
2053         if (v == (void *)1)
2054                 sk = first_unix_socket(&iter->i);
2055         else
2056                 sk = next_unix_socket(&iter->i, sk);
2057         while (sk && (sk->sk_net != iter->p.net))
2058                 sk = next_unix_socket(&iter->i, sk);
2059         return sk;
2060 }
2061
2062 static void unix_seq_stop(struct seq_file *seq, void *v)
2063 {
2064         spin_unlock(&unix_table_lock);
2065 }
2066
2067 static int unix_seq_show(struct seq_file *seq, void *v)
2068 {
2069
2070         if (v == (void *)1)
2071                 seq_puts(seq, "Num       RefCount Protocol Flags    Type St "
2072                          "Inode Path\n");
2073         else {
2074                 struct sock *s = v;
2075                 struct unix_sock *u = unix_sk(s);
2076                 unix_state_lock(s);
2077
2078                 seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
2079                         s,
2080                         atomic_read(&s->sk_refcnt),
2081                         0,
2082                         s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
2083                         s->sk_type,
2084                         s->sk_socket ?
2085                         (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
2086                         (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
2087                         sock_i_ino(s));
2088
2089                 if (u->addr) {
2090                         int i, len;
2091                         seq_putc(seq, ' ');
2092
2093                         i = 0;
2094                         len = u->addr->len - sizeof(short);
2095                         if (!UNIX_ABSTRACT(s))
2096                                 len--;
2097                         else {
2098                                 seq_putc(seq, '@');
2099                                 i++;
2100                         }
2101                         for ( ; i < len; i++)
2102                                 seq_putc(seq, u->addr->name->sun_path[i]);
2103                 }
2104                 unix_state_unlock(s);
2105                 seq_putc(seq, '\n');
2106         }
2107
2108         return 0;
2109 }
2110
2111 static const struct seq_operations unix_seq_ops = {
2112         .start  = unix_seq_start,
2113         .next   = unix_seq_next,
2114         .stop   = unix_seq_stop,
2115         .show   = unix_seq_show,
2116 };
2117
2118
2119 static int unix_seq_open(struct inode *inode, struct file *file)
2120 {
2121         return seq_open_net(inode, file, &unix_seq_ops,
2122                             sizeof(struct unix_iter_state));
2123 }
2124
2125 static const struct file_operations unix_seq_fops = {
2126         .owner          = THIS_MODULE,
2127         .open           = unix_seq_open,
2128         .read           = seq_read,
2129         .llseek         = seq_lseek,
2130         .release        = seq_release_net,
2131 };
2132
2133 #endif
2134
2135 static struct net_proto_family unix_family_ops = {
2136         .family = PF_UNIX,
2137         .create = unix_create,
2138         .owner  = THIS_MODULE,
2139 };
2140
2141
2142 static int unix_net_init(struct net *net)
2143 {
2144         int error = -ENOMEM;
2145
2146 #ifdef CONFIG_PROC_FS
2147         if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops))
2148                 goto out;
2149 #endif
2150         error = 0;
2151 out:
2152         return 0;
2153 }
2154
2155 static void unix_net_exit(struct net *net)
2156 {
2157         proc_net_remove(net, "unix");
2158 }
2159
2160 static struct pernet_operations unix_net_ops = {
2161         .init = unix_net_init,
2162         .exit = unix_net_exit,
2163 };
2164
2165 static int __init af_unix_init(void)
2166 {
2167         int rc = -1;
2168         struct sk_buff *dummy_skb;
2169
2170         BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb));
2171
2172         rc = proto_register(&unix_proto, 1);
2173         if (rc != 0) {
2174                 printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n",
2175                        __FUNCTION__);
2176                 goto out;
2177         }
2178
2179         sock_register(&unix_family_ops);
2180         register_pernet_subsys(&unix_net_ops);
2181         unix_sysctl_register();
2182 out:
2183         return rc;
2184 }
2185
2186 static void __exit af_unix_exit(void)
2187 {
2188         sock_unregister(PF_UNIX);
2189         unix_sysctl_unregister();
2190         proto_unregister(&unix_proto);
2191         unregister_pernet_subsys(&unix_net_ops);
2192 }
2193
2194 module_init(af_unix_init);
2195 module_exit(af_unix_exit);
2196
2197 MODULE_LICENSE("GPL");
2198 MODULE_ALIAS_NETPROTO(PF_UNIX);