git.oblomov.eu Git - linux-2.6/blob - net/ipv4/inet_connection_sock.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Support for INET connection oriented protocols.
   7  *
   8  * Authors:     See the TCP sources
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or(at your option) any later version.
  14  */
  15
  16 #include <linux/config.h>
  17 #include <linux/module.h>
  18 #include <linux/jhash.h>
  19
  20 #include <net/inet_connection_sock.h>
  21 #include <net/inet_hashtables.h>
  22 #include <net/inet_timewait_sock.h>
  23 #include <net/ip.h>
  24 #include <net/route.h>
  25 #include <net/tcp_states.h>
  26 #include <net/xfrm.h>
  27
  28 #ifdef INET_CSK_DEBUG
  29 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
  30 EXPORT_SYMBOL(inet_csk_timer_bug_msg);
  31 #endif
  32
  33 /*
  34  * This array holds the first and last local port number.
  35  * For high-usage systems, use sysctl to change this to
  36  * 32768-61000
  37  */
  38 int sysctl_local_port_range[2] = { 1024, 4999 };
  39
  40 int inet_csk_bind_conflict(const struct sock *sk,
  41                            const struct inet_bind_bucket *tb)
  42 {
  43         const u32 sk_rcv_saddr = inet_rcv_saddr(sk);
  44         struct sock *sk2;
  45         struct hlist_node *node;
  46         int reuse = sk->sk_reuse;
  47
  48         sk_for_each_bound(sk2, node, &tb->owners) {
  49                 if (sk != sk2 &&
  50                     !inet_v6_ipv6only(sk2) &&
  51                     (!sk->sk_bound_dev_if ||
  52                      !sk2->sk_bound_dev_if ||
  53                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  54                         if (!reuse || !sk2->sk_reuse ||
  55                             sk2->sk_state == TCP_LISTEN) {
  56                                 const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
  57                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
  58                                     sk2_rcv_saddr == sk_rcv_saddr)
  59                                         break;
  60                         }
  61                 }
  62         }
  63         return node != NULL;
  64 }
  65
  66 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  67
  68 /* Obtain a reference to a local port for the given sock,
  69  * if snum is zero it means select any available local port.
  70  */
  71 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
  72                       struct sock *sk, unsigned short snum,
  73                       int (*bind_conflict)(const struct sock *sk,
  74                                            const struct inet_bind_bucket *tb))
  75 {
  76         struct inet_bind_hashbucket *head;
  77         struct hlist_node *node;
  78         struct inet_bind_bucket *tb;
  79         int ret;
  80
  81         local_bh_disable();
  82         if (!snum) {
  83                 int low = sysctl_local_port_range[0];
  84                 int high = sysctl_local_port_range[1];
  85                 int remaining = (high - low) + 1;
  86                 int rover = net_random() % (high - low) + low;
  87
  88                 do {
  89                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
  90                         spin_lock(&head->lock);
  91                         inet_bind_bucket_for_each(tb, node, &head->chain)
  92                                 if (tb->port == rover)
  93                                         goto next;
  94                         break;
  95                 next:
  96                         spin_unlock(&head->lock);
  97                         if (++rover > high)
  98                                 rover = low;
  99                 } while (--remaining > 0);
 100
 101                 /* Exhausted local port range during search?  It is not
 102                  * possible for us to be holding one of the bind hash
 103                  * locks if this test triggers, because if 'remaining'
 104                  * drops to zero, we broke out of the do/while loop at
 105                  * the top level, not from the 'break;' statement.
 106                  */
 107                 ret = 1;
 108                 if (remaining <= 0)
 109                         goto fail;
 110
 111                 /* OK, here is the one we will use.  HEAD is
 112                  * non-NULL and we hold it's mutex.
 113                  */
 114                 snum = rover;
 115         } else {
 116                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 117                 spin_lock(&head->lock);
 118                 inet_bind_bucket_for_each(tb, node, &head->chain)
 119                         if (tb->port == snum)
 120                                 goto tb_found;
 121         }
 122         tb = NULL;
 123         goto tb_not_found;
 124 tb_found:
 125         if (!hlist_empty(&tb->owners)) {
 126                 if (sk->sk_reuse > 1)
 127                         goto success;
 128                 if (tb->fastreuse > 0 &&
 129                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 130                         goto success;
 131                 } else {
 132                         ret = 1;
 133                         if (bind_conflict(sk, tb))
 134                                 goto fail_unlock;
 135                 }
 136         }
 137 tb_not_found:
 138         ret = 1;
 139         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
 140                 goto fail_unlock;
 141         if (hlist_empty(&tb->owners)) {
 142                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 143                         tb->fastreuse = 1;
 144                 else
 145                         tb->fastreuse = 0;
 146         } else if (tb->fastreuse &&
 147                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 148                 tb->fastreuse = 0;
 149 success:
 150         if (!inet_csk(sk)->icsk_bind_hash)
 151                 inet_bind_hash(sk, tb, snum);
 152         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 153         ret = 0;
 154
 155 fail_unlock:
 156         spin_unlock(&head->lock);
 157 fail:
 158         local_bh_enable();
 159         return ret;
 160 }
 161
 162 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 163
 164 /*
 165  * Wait for an incoming connection, avoid race conditions. This must be called
 166  * with the socket locked.
 167  */
 168 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 169 {
 170         struct inet_connection_sock *icsk = inet_csk(sk);
 171         DEFINE_WAIT(wait);
 172         int err;
 173
 174         /*
 175          * True wake-one mechanism for incoming connections: only
 176          * one process gets woken up, not the 'whole herd'.
 177          * Since we do not 'race & poll' for established sockets
 178          * anymore, the common case will execute the loop only once.
 179          *
 180          * Subtle issue: "add_wait_queue_exclusive()" will be added
 181          * after any current non-exclusive waiters, and we know that
 182          * it will always _stay_ after any new non-exclusive waiters
 183          * because all non-exclusive waiters are added at the
 184          * beginning of the wait-queue. As such, it's ok to "drop"
 185          * our exclusiveness temporarily when we get woken up without
 186          * having to remove and re-insert us on the wait queue.
 187          */
 188         for (;;) {
 189                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 190                                           TASK_INTERRUPTIBLE);
 191                 release_sock(sk);
 192                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 193                         timeo = schedule_timeout(timeo);
 194                 lock_sock(sk);
 195                 err = 0;
 196                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 197                         break;
 198                 err = -EINVAL;
 199                 if (sk->sk_state != TCP_LISTEN)
 200                         break;
 201                 err = sock_intr_errno(timeo);
 202                 if (signal_pending(current))
 203                         break;
 204                 err = -EAGAIN;
 205                 if (!timeo)
 206                         break;
 207         }
 208         finish_wait(sk->sk_sleep, &wait);
 209         return err;
 210 }
 211
 212 /*
 213  * This will accept the next outstanding connection.
 214  */
 215 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 216 {
 217         struct inet_connection_sock *icsk = inet_csk(sk);
 218         struct sock *newsk;
 219         int error;
 220
 221         lock_sock(sk);
 222
 223         /* We need to make sure that this socket is listening,
 224          * and that it has something pending.
 225          */
 226         error = -EINVAL;
 227         if (sk->sk_state != TCP_LISTEN)
 228                 goto out_err;
 229
 230         /* Find already established connection */
 231         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 232                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 233
 234                 /* If this is a non blocking socket don't sleep */
 235                 error = -EAGAIN;
 236                 if (!timeo)
 237                         goto out_err;
 238
 239                 error = inet_csk_wait_for_connect(sk, timeo);
 240                 if (error)
 241                         goto out_err;
 242         }
 243
 244         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 245         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 246 out:
 247         release_sock(sk);
 248         return newsk;
 249 out_err:
 250         newsk = NULL;
 251         *err = error;
 252         goto out;
 253 }
 254
 255 EXPORT_SYMBOL(inet_csk_accept);
 256
 257 /*
 258  * Using different timers for retransmit, delayed acks and probes
 259  * We may wish use just one timer maintaining a list of expire jiffies
 260  * to optimize.
 261  */
 262 void inet_csk_init_xmit_timers(struct sock *sk,
 263                                void (*retransmit_handler)(unsigned long),
 264                                void (*delack_handler)(unsigned long),
 265                                void (*keepalive_handler)(unsigned long))
 266 {
 267         struct inet_connection_sock *icsk = inet_csk(sk);
 268
 269         init_timer(&icsk->icsk_retransmit_timer);
 270         init_timer(&icsk->icsk_delack_timer);
 271         init_timer(&sk->sk_timer);
 272
 273         icsk->icsk_retransmit_timer.function = retransmit_handler;
 274         icsk->icsk_delack_timer.function     = delack_handler;
 275         sk->sk_timer.function                = keepalive_handler;
 276
 277         icsk->icsk_retransmit_timer.data =
 278                 icsk->icsk_delack_timer.data =
 279                         sk->sk_timer.data  = (unsigned long)sk;
 280
 281         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 282 }
 283
 284 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 285
 286 void inet_csk_clear_xmit_timers(struct sock *sk)
 287 {
 288         struct inet_connection_sock *icsk = inet_csk(sk);
 289
 290         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 291
 292         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 293         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 294         sk_stop_timer(sk, &sk->sk_timer);
 295 }
 296
 297 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 298
 299 void inet_csk_delete_keepalive_timer(struct sock *sk)
 300 {
 301         sk_stop_timer(sk, &sk->sk_timer);
 302 }
 303
 304 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 305
 306 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 307 {
 308         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 309 }
 310
 311 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 312
 313 struct dst_entry* inet_csk_route_req(struct sock *sk,
 314                                      const struct request_sock *req)
 315 {
 316         struct rtable *rt;
 317         const struct inet_request_sock *ireq = inet_rsk(req);
 318         struct ip_options *opt = inet_rsk(req)->opt;
 319         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 320                             .nl_u = { .ip4_u =
 321                                       { .daddr = ((opt && opt->srr) ?
 322                                                   opt->faddr :
 323                                                   ireq->rmt_addr),
 324                                         .saddr = ireq->loc_addr,
 325                                         .tos = RT_CONN_FLAGS(sk) } },
 326                             .proto = sk->sk_protocol,
 327                             .uli_u = { .ports =
 328                                        { .sport = inet_sk(sk)->sport,
 329                                          .dport = ireq->rmt_port } } };
 330
 331         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 332                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 333                 return NULL;
 334         }
 335         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 336                 ip_rt_put(rt);
 337                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 338                 return NULL;
 339         }
 340         return &rt->u.dst;
 341 }
 342
 343 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 344
 345 static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
 346                                  const u32 rnd, const u16 synq_hsize)
 347 {
 348         return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
 349 }
 350
 351 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 352 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 353 #else
 354 #define AF_INET_FAMILY(fam) 1
 355 #endif
 356
 357 struct request_sock *inet_csk_search_req(const struct sock *sk,
 358                                          struct request_sock ***prevp,
 359                                          const __u16 rport, const __u32 raddr,
 360                                          const __u32 laddr)
 361 {
 362         const struct inet_connection_sock *icsk = inet_csk(sk);
 363         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 364         struct request_sock *req, **prev;
 365
 366         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 367                                                     lopt->nr_table_entries)];
 368              (req = *prev) != NULL;
 369              prev = &req->dl_next) {
 370                 const struct inet_request_sock *ireq = inet_rsk(req);
 371
 372                 if (ireq->rmt_port == rport &&
 373                     ireq->rmt_addr == raddr &&
 374                     ireq->loc_addr == laddr &&
 375                     AF_INET_FAMILY(req->rsk_ops->family)) {
 376                         BUG_TRAP(!req->sk);
 377                         *prevp = prev;
 378                         break;
 379                 }
 380         }
 381
 382         return req;
 383 }
 384
 385 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 386
 387 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 388                                    const unsigned timeout)
 389 {
 390         struct inet_connection_sock *icsk = inet_csk(sk);
 391         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 392         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 393                                      lopt->hash_rnd, lopt->nr_table_entries);
 394
 395         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 396         inet_csk_reqsk_queue_added(sk, timeout);
 397 }
 398
 399 /* Only thing we need from tcp.h */
 400 extern int sysctl_tcp_synack_retries;
 401
 402 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 403
 404 void inet_csk_reqsk_queue_prune(struct sock *parent,
 405                                 const unsigned long interval,
 406                                 const unsigned long timeout,
 407                                 const unsigned long max_rto)
 408 {
 409         struct inet_connection_sock *icsk = inet_csk(parent);
 410         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 411         struct listen_sock *lopt = queue->listen_opt;
 412         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 413         int thresh = max_retries;
 414         unsigned long now = jiffies;
 415         struct request_sock **reqp, *req;
 416         int i, budget;
 417
 418         if (lopt == NULL || lopt->qlen == 0)
 419                 return;
 420
 421         /* Normally all the openreqs are young and become mature
 422          * (i.e. converted to established socket) for first timeout.
 423          * If synack was not acknowledged for 3 seconds, it means
 424          * one of the following things: synack was lost, ack was lost,
 425          * rtt is high or nobody planned to ack (i.e. synflood).
 426          * When server is a bit loaded, queue is populated with old
 427          * open requests, reducing effective size of queue.
 428          * When server is well loaded, queue size reduces to zero
 429          * after several minutes of work. It is not synflood,
 430          * it is normal operation. The solution is pruning
 431          * too old entries overriding normal timeout, when
 432          * situation becomes dangerous.
 433          *
 434          * Essentially, we reserve half of room for young
 435          * embrions; and abort old ones without pity, if old
 436          * ones are about to clog our table.
 437          */
 438         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 439                 int young = (lopt->qlen_young<<1);
 440
 441                 while (thresh > 2) {
 442                         if (lopt->qlen < young)
 443                                 break;
 444                         thresh--;
 445                         young <<= 1;
 446                 }
 447         }
 448
 449         if (queue->rskq_defer_accept)
 450                 max_retries = queue->rskq_defer_accept;
 451
 452         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 453         i = lopt->clock_hand;
 454
 455         do {
 456                 reqp=&lopt->syn_table[i];
 457                 while ((req = *reqp) != NULL) {
 458                         if (time_after_eq(now, req->expires)) {
 459                                 if ((req->retrans < thresh ||
 460                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 461                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 462                                         unsigned long timeo;
 463
 464                                         if (req->retrans++ == 0)
 465                                                 lopt->qlen_young--;
 466                                         timeo = min((timeout << req->retrans), max_rto);
 467                                         req->expires = now + timeo;
 468                                         reqp = &req->dl_next;
 469                                         continue;
 470                                 }
 471
 472                                 /* Drop this request */
 473                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 474                                 reqsk_queue_removed(queue, req);
 475                                 reqsk_free(req);
 476                                 continue;
 477                         }
 478                         reqp = &req->dl_next;
 479                 }
 480
 481                 i = (i + 1) & (lopt->nr_table_entries - 1);
 482
 483         } while (--budget > 0);
 484
 485         lopt->clock_hand = i;
 486
 487         if (lopt->qlen)
 488                 inet_csk_reset_keepalive_timer(parent, interval);
 489 }
 490
 491 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 492
 493 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 494                             const gfp_t priority)
 495 {
 496         struct sock *newsk = sk_clone(sk, priority);
 497
 498         if (newsk != NULL) {
 499                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 500
 501                 newsk->sk_state = TCP_SYN_RECV;
 502                 newicsk->icsk_bind_hash = NULL;
 503
 504                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 505                 newsk->sk_write_space = sk_stream_write_space;
 506
 507                 newicsk->icsk_retransmits = 0;
 508                 newicsk->icsk_backoff     = 0;
 509                 newicsk->icsk_probes_out  = 0;
 510
 511                 /* Deinitialize accept_queue to trap illegal accesses. */
 512                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 513         }
 514         return newsk;
 515 }
 516
 517 EXPORT_SYMBOL_GPL(inet_csk_clone);
 518
 519 /*
 520  * At this point, there should be no process reference to this
 521  * socket, and thus no user references at all.  Therefore we
 522  * can assume the socket waitqueue is inactive and nobody will
 523  * try to jump onto it.
 524  */
 525 void inet_csk_destroy_sock(struct sock *sk)
 526 {
 527         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 528         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 529
 530         /* It cannot be in hash table! */
 531         BUG_TRAP(sk_unhashed(sk));
 532
 533         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 534         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 535
 536         sk->sk_prot->destroy(sk);
 537
 538         sk_stream_kill_queues(sk);
 539
 540         xfrm_sk_free_policy(sk);
 541
 542         sk_refcnt_debug_release(sk);
 543
 544         atomic_dec(sk->sk_prot->orphan_count);
 545         sock_put(sk);
 546 }
 547
 548 EXPORT_SYMBOL(inet_csk_destroy_sock);
 549
 550 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 551 {
 552         struct inet_sock *inet = inet_sk(sk);
 553         struct inet_connection_sock *icsk = inet_csk(sk);
 554         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 555
 556         if (rc != 0)
 557                 return rc;
 558
 559         sk->sk_max_ack_backlog = 0;
 560         sk->sk_ack_backlog = 0;
 561         inet_csk_delack_init(sk);
 562
 563         /* There is race window here: we announce ourselves listening,
 564          * but this transition is still not validated by get_port().
 565          * It is OK, because this socket enters to hash table only
 566          * after validation is complete.
 567          */
 568         sk->sk_state = TCP_LISTEN;
 569         if (!sk->sk_prot->get_port(sk, inet->num)) {
 570                 inet->sport = htons(inet->num);
 571
 572                 sk_dst_reset(sk);
 573                 sk->sk_prot->hash(sk);
 574
 575                 return 0;
 576         }
 577
 578         sk->sk_state = TCP_CLOSE;
 579         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 580         return -EADDRINUSE;
 581 }
 582
 583 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 584
 585 /*
 586  *      This routine closes sockets which have been at least partially
 587  *      opened, but not yet accepted.
 588  */
 589 void inet_csk_listen_stop(struct sock *sk)
 590 {
 591         struct inet_connection_sock *icsk = inet_csk(sk);
 592         struct request_sock *acc_req;
 593         struct request_sock *req;
 594
 595         inet_csk_delete_keepalive_timer(sk);
 596
 597         /* make all the listen_opt local to us */
 598         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 599
 600         /* Following specs, it would be better either to send FIN
 601          * (and enter FIN-WAIT-1, it is normal close)
 602          * or to send active reset (abort).
 603          * Certainly, it is pretty dangerous while synflood, but it is
 604          * bad justification for our negligence 8)
 605          * To be honest, we are not able to make either
 606          * of the variants now.                 --ANK
 607          */
 608         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 609
 610         while ((req = acc_req) != NULL) {
 611                 struct sock *child = req->sk;
 612
 613                 acc_req = req->dl_next;
 614
 615                 local_bh_disable();
 616                 bh_lock_sock(child);
 617                 BUG_TRAP(!sock_owned_by_user(child));
 618                 sock_hold(child);
 619
 620                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 621
 622                 sock_orphan(child);
 623
 624                 atomic_inc(sk->sk_prot->orphan_count);
 625
 626                 inet_csk_destroy_sock(child);
 627
 628                 bh_unlock_sock(child);
 629                 local_bh_enable();
 630                 sock_put(child);
 631
 632                 sk_acceptq_removed(sk);
 633                 __reqsk_free(req);
 634         }
 635         BUG_TRAP(!sk->sk_ack_backlog);
 636 }
 637
 638 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);