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/module.h>
  17 #include <linux/jhash.h>
  18
  19 #include <net/inet_connection_sock.h>
  20 #include <net/inet_hashtables.h>
  21 #include <net/inet_timewait_sock.h>
  22 #include <net/ip.h>
  23 #include <net/route.h>
  24 #include <net/tcp_states.h>
  25 #include <net/xfrm.h>
  26
  27 #ifdef INET_CSK_DEBUG
  28 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
  29 EXPORT_SYMBOL(inet_csk_timer_bug_msg);
  30 #endif
  31
  32 /*
  33  * This array holds the first and last local port number.
  34  */
  35 int sysctl_local_port_range[2] = { 32768, 61000 };
  36 DEFINE_SEQLOCK(sysctl_port_range_lock);
  37
  38 void inet_get_local_port_range(int *low, int *high)
  39 {
  40         unsigned seq;
  41         do {
  42                 seq = read_seqbegin(&sysctl_port_range_lock);
  43
  44                 *low = sysctl_local_port_range[0];
  45                 *high = sysctl_local_port_range[1];
  46         } while (read_seqretry(&sysctl_port_range_lock, seq));
  47 }
  48 EXPORT_SYMBOL(inet_get_local_port_range);
  49
  50 int inet_csk_bind_conflict(const struct sock *sk,
  51                            const struct inet_bind_bucket *tb)
  52 {
  53         const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
  54         struct sock *sk2;
  55         struct hlist_node *node;
  56         int reuse = sk->sk_reuse;
  57
  58         /*
  59          * Unlike other sk lookup places we do not check
  60          * for sk_net here, since _all_ the socks listed
  61          * in tb->owners list belong to the same net - the
  62          * one this bucket belongs to.
  63          */
  64
  65         sk_for_each_bound(sk2, node, &tb->owners) {
  66                 if (sk != sk2 &&
  67                     !inet_v6_ipv6only(sk2) &&
  68                     (!sk->sk_bound_dev_if ||
  69                      !sk2->sk_bound_dev_if ||
  70                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  71                         if (!reuse || !sk2->sk_reuse ||
  72                             sk2->sk_state == TCP_LISTEN) {
  73                                 const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
  74                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
  75                                     sk2_rcv_saddr == sk_rcv_saddr)
  76                                         break;
  77                         }
  78                 }
  79         }
  80         return node != NULL;
  81 }
  82
  83 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  84
  85 /* Obtain a reference to a local port for the given sock,
  86  * if snum is zero it means select any available local port.
  87  */
  88 int inet_csk_get_port(struct sock *sk, unsigned short snum)
  89 {
  90         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
  91         struct inet_bind_hashbucket *head;
  92         struct hlist_node *node;
  93         struct inet_bind_bucket *tb;
  94         int ret;
  95         struct net *net = sock_net(sk);
  96
  97         local_bh_disable();
  98         if (!snum) {
  99                 int remaining, rover, low, high;
 100
 101                 inet_get_local_port_range(&low, &high);
 102                 remaining = (high - low) + 1;
 103                 rover = net_random() % remaining + low;
 104
 105                 do {
 106                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
 107                         spin_lock(&head->lock);
 108                         inet_bind_bucket_for_each(tb, node, &head->chain)
 109                                 if (tb->ib_net == net && tb->port == rover)
 110                                         goto next;
 111                         break;
 112                 next:
 113                         spin_unlock(&head->lock);
 114                         if (++rover > high)
 115                                 rover = low;
 116                 } while (--remaining > 0);
 117
 118                 /* Exhausted local port range during search?  It is not
 119                  * possible for us to be holding one of the bind hash
 120                  * locks if this test triggers, because if 'remaining'
 121                  * drops to zero, we broke out of the do/while loop at
 122                  * the top level, not from the 'break;' statement.
 123                  */
 124                 ret = 1;
 125                 if (remaining <= 0)
 126                         goto fail;
 127
 128                 /* OK, here is the one we will use.  HEAD is
 129                  * non-NULL and we hold it's mutex.
 130                  */
 131                 snum = rover;
 132         } else {
 133                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 134                 spin_lock(&head->lock);
 135                 inet_bind_bucket_for_each(tb, node, &head->chain)
 136                         if (tb->ib_net == net && tb->port == snum)
 137                                 goto tb_found;
 138         }
 139         tb = NULL;
 140         goto tb_not_found;
 141 tb_found:
 142         if (!hlist_empty(&tb->owners)) {
 143                 if (tb->fastreuse > 0 &&
 144                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 145                         goto success;
 146                 } else {
 147                         ret = 1;
 148                         if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb))
 149                                 goto fail_unlock;
 150                 }
 151         }
 152 tb_not_found:
 153         ret = 1;
 154         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
 155                                         net, head, snum)) == NULL)
 156                 goto fail_unlock;
 157         if (hlist_empty(&tb->owners)) {
 158                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 159                         tb->fastreuse = 1;
 160                 else
 161                         tb->fastreuse = 0;
 162         } else if (tb->fastreuse &&
 163                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 164                 tb->fastreuse = 0;
 165 success:
 166         if (!inet_csk(sk)->icsk_bind_hash)
 167                 inet_bind_hash(sk, tb, snum);
 168         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 169         ret = 0;
 170
 171 fail_unlock:
 172         spin_unlock(&head->lock);
 173 fail:
 174         local_bh_enable();
 175         return ret;
 176 }
 177
 178 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 179
 180 /*
 181  * Wait for an incoming connection, avoid race conditions. This must be called
 182  * with the socket locked.
 183  */
 184 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 185 {
 186         struct inet_connection_sock *icsk = inet_csk(sk);
 187         DEFINE_WAIT(wait);
 188         int err;
 189
 190         /*
 191          * True wake-one mechanism for incoming connections: only
 192          * one process gets woken up, not the 'whole herd'.
 193          * Since we do not 'race & poll' for established sockets
 194          * anymore, the common case will execute the loop only once.
 195          *
 196          * Subtle issue: "add_wait_queue_exclusive()" will be added
 197          * after any current non-exclusive waiters, and we know that
 198          * it will always _stay_ after any new non-exclusive waiters
 199          * because all non-exclusive waiters are added at the
 200          * beginning of the wait-queue. As such, it's ok to "drop"
 201          * our exclusiveness temporarily when we get woken up without
 202          * having to remove and re-insert us on the wait queue.
 203          */
 204         for (;;) {
 205                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 206                                           TASK_INTERRUPTIBLE);
 207                 release_sock(sk);
 208                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 209                         timeo = schedule_timeout(timeo);
 210                 lock_sock(sk);
 211                 err = 0;
 212                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 213                         break;
 214                 err = -EINVAL;
 215                 if (sk->sk_state != TCP_LISTEN)
 216                         break;
 217                 err = sock_intr_errno(timeo);
 218                 if (signal_pending(current))
 219                         break;
 220                 err = -EAGAIN;
 221                 if (!timeo)
 222                         break;
 223         }
 224         finish_wait(sk->sk_sleep, &wait);
 225         return err;
 226 }
 227
 228 /*
 229  * This will accept the next outstanding connection.
 230  */
 231 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 232 {
 233         struct inet_connection_sock *icsk = inet_csk(sk);
 234         struct sock *newsk;
 235         int error;
 236
 237         lock_sock(sk);
 238
 239         /* We need to make sure that this socket is listening,
 240          * and that it has something pending.
 241          */
 242         error = -EINVAL;
 243         if (sk->sk_state != TCP_LISTEN)
 244                 goto out_err;
 245
 246         /* Find already established connection */
 247         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 248                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 249
 250                 /* If this is a non blocking socket don't sleep */
 251                 error = -EAGAIN;
 252                 if (!timeo)
 253                         goto out_err;
 254
 255                 error = inet_csk_wait_for_connect(sk, timeo);
 256                 if (error)
 257                         goto out_err;
 258         }
 259
 260         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 261         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 262 out:
 263         release_sock(sk);
 264         return newsk;
 265 out_err:
 266         newsk = NULL;
 267         *err = error;
 268         goto out;
 269 }
 270
 271 EXPORT_SYMBOL(inet_csk_accept);
 272
 273 /*
 274  * Using different timers for retransmit, delayed acks and probes
 275  * We may wish use just one timer maintaining a list of expire jiffies
 276  * to optimize.
 277  */
 278 void inet_csk_init_xmit_timers(struct sock *sk,
 279                                void (*retransmit_handler)(unsigned long),
 280                                void (*delack_handler)(unsigned long),
 281                                void (*keepalive_handler)(unsigned long))
 282 {
 283         struct inet_connection_sock *icsk = inet_csk(sk);
 284
 285         setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
 286                         (unsigned long)sk);
 287         setup_timer(&icsk->icsk_delack_timer, delack_handler,
 288                         (unsigned long)sk);
 289         setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
 290         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 291 }
 292
 293 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 294
 295 void inet_csk_clear_xmit_timers(struct sock *sk)
 296 {
 297         struct inet_connection_sock *icsk = inet_csk(sk);
 298
 299         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 300
 301         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 302         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 303         sk_stop_timer(sk, &sk->sk_timer);
 304 }
 305
 306 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 307
 308 void inet_csk_delete_keepalive_timer(struct sock *sk)
 309 {
 310         sk_stop_timer(sk, &sk->sk_timer);
 311 }
 312
 313 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 314
 315 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 316 {
 317         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 318 }
 319
 320 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 321
 322 struct dst_entry* inet_csk_route_req(struct sock *sk,
 323                                      const struct request_sock *req)
 324 {
 325         struct rtable *rt;
 326         const struct inet_request_sock *ireq = inet_rsk(req);
 327         struct ip_options *opt = inet_rsk(req)->opt;
 328         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 329                             .nl_u = { .ip4_u =
 330                                       { .daddr = ((opt && opt->srr) ?
 331                                                   opt->faddr :
 332                                                   ireq->rmt_addr),
 333                                         .saddr = ireq->loc_addr,
 334                                         .tos = RT_CONN_FLAGS(sk) } },
 335                             .proto = sk->sk_protocol,
 336                             .uli_u = { .ports =
 337                                        { .sport = inet_sk(sk)->sport,
 338                                          .dport = ireq->rmt_port } } };
 339
 340         security_req_classify_flow(req, &fl);
 341         if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) {
 342                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 343                 return NULL;
 344         }
 345         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 346                 ip_rt_put(rt);
 347                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 348                 return NULL;
 349         }
 350         return &rt->u.dst;
 351 }
 352
 353 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 354
 355 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
 356                                  const u32 rnd, const u32 synq_hsize)
 357 {
 358         return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
 359 }
 360
 361 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 362 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 363 #else
 364 #define AF_INET_FAMILY(fam) 1
 365 #endif
 366
 367 struct request_sock *inet_csk_search_req(const struct sock *sk,
 368                                          struct request_sock ***prevp,
 369                                          const __be16 rport, const __be32 raddr,
 370                                          const __be32 laddr)
 371 {
 372         const struct inet_connection_sock *icsk = inet_csk(sk);
 373         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 374         struct request_sock *req, **prev;
 375
 376         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 377                                                     lopt->nr_table_entries)];
 378              (req = *prev) != NULL;
 379              prev = &req->dl_next) {
 380                 const struct inet_request_sock *ireq = inet_rsk(req);
 381
 382                 if (ireq->rmt_port == rport &&
 383                     ireq->rmt_addr == raddr &&
 384                     ireq->loc_addr == laddr &&
 385                     AF_INET_FAMILY(req->rsk_ops->family)) {
 386                         BUG_TRAP(!req->sk);
 387                         *prevp = prev;
 388                         break;
 389                 }
 390         }
 391
 392         return req;
 393 }
 394
 395 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 396
 397 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 398                                    unsigned long timeout)
 399 {
 400         struct inet_connection_sock *icsk = inet_csk(sk);
 401         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 402         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 403                                      lopt->hash_rnd, lopt->nr_table_entries);
 404
 405         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 406         inet_csk_reqsk_queue_added(sk, timeout);
 407 }
 408
 409 /* Only thing we need from tcp.h */
 410 extern int sysctl_tcp_synack_retries;
 411
 412 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 413
 414 void inet_csk_reqsk_queue_prune(struct sock *parent,
 415                                 const unsigned long interval,
 416                                 const unsigned long timeout,
 417                                 const unsigned long max_rto)
 418 {
 419         struct inet_connection_sock *icsk = inet_csk(parent);
 420         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 421         struct listen_sock *lopt = queue->listen_opt;
 422         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 423         int thresh = max_retries;
 424         unsigned long now = jiffies;
 425         struct request_sock **reqp, *req;
 426         int i, budget;
 427
 428         if (lopt == NULL || lopt->qlen == 0)
 429                 return;
 430
 431         /* Normally all the openreqs are young and become mature
 432          * (i.e. converted to established socket) for first timeout.
 433          * If synack was not acknowledged for 3 seconds, it means
 434          * one of the following things: synack was lost, ack was lost,
 435          * rtt is high or nobody planned to ack (i.e. synflood).
 436          * When server is a bit loaded, queue is populated with old
 437          * open requests, reducing effective size of queue.
 438          * When server is well loaded, queue size reduces to zero
 439          * after several minutes of work. It is not synflood,
 440          * it is normal operation. The solution is pruning
 441          * too old entries overriding normal timeout, when
 442          * situation becomes dangerous.
 443          *
 444          * Essentially, we reserve half of room for young
 445          * embrions; and abort old ones without pity, if old
 446          * ones are about to clog our table.
 447          */
 448         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 449                 int young = (lopt->qlen_young<<1);
 450
 451                 while (thresh > 2) {
 452                         if (lopt->qlen < young)
 453                                 break;
 454                         thresh--;
 455                         young <<= 1;
 456                 }
 457         }
 458
 459         if (queue->rskq_defer_accept)
 460                 max_retries = queue->rskq_defer_accept;
 461
 462         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 463         i = lopt->clock_hand;
 464
 465         do {
 466                 reqp=&lopt->syn_table[i];
 467                 while ((req = *reqp) != NULL) {
 468                         if (time_after_eq(now, req->expires)) {
 469                                 if ((req->retrans < thresh ||
 470                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 471                                     && !req->rsk_ops->rtx_syn_ack(parent, req)) {
 472                                         unsigned long timeo;
 473
 474                                         if (req->retrans++ == 0)
 475                                                 lopt->qlen_young--;
 476                                         timeo = min((timeout << req->retrans), max_rto);
 477                                         req->expires = now + timeo;
 478                                         reqp = &req->dl_next;
 479                                         continue;
 480                                 }
 481
 482                                 /* Drop this request */
 483                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 484                                 reqsk_queue_removed(queue, req);
 485                                 reqsk_free(req);
 486                                 continue;
 487                         }
 488                         reqp = &req->dl_next;
 489                 }
 490
 491                 i = (i + 1) & (lopt->nr_table_entries - 1);
 492
 493         } while (--budget > 0);
 494
 495         lopt->clock_hand = i;
 496
 497         if (lopt->qlen)
 498                 inet_csk_reset_keepalive_timer(parent, interval);
 499 }
 500
 501 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 502
 503 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 504                             const gfp_t priority)
 505 {
 506         struct sock *newsk = sk_clone(sk, priority);
 507
 508         if (newsk != NULL) {
 509                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 510
 511                 newsk->sk_state = TCP_SYN_RECV;
 512                 newicsk->icsk_bind_hash = NULL;
 513
 514                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 515                 newsk->sk_write_space = sk_stream_write_space;
 516
 517                 newicsk->icsk_retransmits = 0;
 518                 newicsk->icsk_backoff     = 0;
 519                 newicsk->icsk_probes_out  = 0;
 520
 521                 /* Deinitialize accept_queue to trap illegal accesses. */
 522                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 523
 524                 security_inet_csk_clone(newsk, req);
 525         }
 526         return newsk;
 527 }
 528
 529 EXPORT_SYMBOL_GPL(inet_csk_clone);
 530
 531 /*
 532  * At this point, there should be no process reference to this
 533  * socket, and thus no user references at all.  Therefore we
 534  * can assume the socket waitqueue is inactive and nobody will
 535  * try to jump onto it.
 536  */
 537 void inet_csk_destroy_sock(struct sock *sk)
 538 {
 539         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 540         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 541
 542         /* It cannot be in hash table! */
 543         BUG_TRAP(sk_unhashed(sk));
 544
 545         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 546         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 547
 548         sk->sk_prot->destroy(sk);
 549
 550         sk_stream_kill_queues(sk);
 551
 552         xfrm_sk_free_policy(sk);
 553
 554         sk_refcnt_debug_release(sk);
 555
 556         atomic_dec(sk->sk_prot->orphan_count);
 557         sock_put(sk);
 558 }
 559
 560 EXPORT_SYMBOL(inet_csk_destroy_sock);
 561
 562 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 563 {
 564         struct inet_sock *inet = inet_sk(sk);
 565         struct inet_connection_sock *icsk = inet_csk(sk);
 566         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 567
 568         if (rc != 0)
 569                 return rc;
 570
 571         sk->sk_max_ack_backlog = 0;
 572         sk->sk_ack_backlog = 0;
 573         inet_csk_delack_init(sk);
 574
 575         /* There is race window here: we announce ourselves listening,
 576          * but this transition is still not validated by get_port().
 577          * It is OK, because this socket enters to hash table only
 578          * after validation is complete.
 579          */
 580         sk->sk_state = TCP_LISTEN;
 581         if (!sk->sk_prot->get_port(sk, inet->num)) {
 582                 inet->sport = htons(inet->num);
 583
 584                 sk_dst_reset(sk);
 585                 sk->sk_prot->hash(sk);
 586
 587                 return 0;
 588         }
 589
 590         sk->sk_state = TCP_CLOSE;
 591         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 592         return -EADDRINUSE;
 593 }
 594
 595 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 596
 597 /*
 598  *      This routine closes sockets which have been at least partially
 599  *      opened, but not yet accepted.
 600  */
 601 void inet_csk_listen_stop(struct sock *sk)
 602 {
 603         struct inet_connection_sock *icsk = inet_csk(sk);
 604         struct request_sock *acc_req;
 605         struct request_sock *req;
 606
 607         inet_csk_delete_keepalive_timer(sk);
 608
 609         /* make all the listen_opt local to us */
 610         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 611
 612         /* Following specs, it would be better either to send FIN
 613          * (and enter FIN-WAIT-1, it is normal close)
 614          * or to send active reset (abort).
 615          * Certainly, it is pretty dangerous while synflood, but it is
 616          * bad justification for our negligence 8)
 617          * To be honest, we are not able to make either
 618          * of the variants now.                 --ANK
 619          */
 620         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 621
 622         while ((req = acc_req) != NULL) {
 623                 struct sock *child = req->sk;
 624
 625                 acc_req = req->dl_next;
 626
 627                 local_bh_disable();
 628                 bh_lock_sock(child);
 629                 BUG_TRAP(!sock_owned_by_user(child));
 630                 sock_hold(child);
 631
 632                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 633
 634                 sock_orphan(child);
 635
 636                 atomic_inc(sk->sk_prot->orphan_count);
 637
 638                 inet_csk_destroy_sock(child);
 639
 640                 bh_unlock_sock(child);
 641                 local_bh_enable();
 642                 sock_put(child);
 643
 644                 sk_acceptq_removed(sk);
 645                 __reqsk_free(req);
 646         }
 647         BUG_TRAP(!sk->sk_ack_backlog);
 648 }
 649
 650 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 651
 652 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 653 {
 654         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 655         const struct inet_sock *inet = inet_sk(sk);
 656
 657         sin->sin_family         = AF_INET;
 658         sin->sin_addr.s_addr    = inet->daddr;
 659         sin->sin_port           = inet->dport;
 660 }
 661
 662 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 663
 664 #ifdef CONFIG_COMPAT
 665 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 666                                char __user *optval, int __user *optlen)
 667 {
 668         const struct inet_connection_sock *icsk = inet_csk(sk);
 669
 670         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 671                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 672                                                             optval, optlen);
 673         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 674                                              optval, optlen);
 675 }
 676
 677 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 678
 679 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 680                                char __user *optval, int optlen)
 681 {
 682         const struct inet_connection_sock *icsk = inet_csk(sk);
 683
 684         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 685                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 686                                                             optval, optlen);
 687         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 688                                              optval, optlen);
 689 }
 690
 691 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 692 #endif