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 struct holds the first and last local port number.
  34  */
  35 struct local_ports sysctl_local_ports __read_mostly = {
  36         .lock = SEQLOCK_UNLOCKED,
  37         .range = { 32768, 61000 },
  38 };
  39
  40 void inet_get_local_port_range(int *low, int *high)
  41 {
  42         unsigned seq;
  43         do {
  44                 seq = read_seqbegin(&sysctl_local_ports.lock);
  45
  46                 *low = sysctl_local_ports.range[0];
  47                 *high = sysctl_local_ports.range[1];
  48         } while (read_seqretry(&sysctl_local_ports.lock, seq));
  49 }
  50 EXPORT_SYMBOL(inet_get_local_port_range);
  51
  52 int inet_csk_bind_conflict(const struct sock *sk,
  53                            const struct inet_bind_bucket *tb)
  54 {
  55         const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
  56         struct sock *sk2;
  57         struct hlist_node *node;
  58         int reuse = sk->sk_reuse;
  59
  60         /*
  61          * Unlike other sk lookup places we do not check
  62          * for sk_net here, since _all_ the socks listed
  63          * in tb->owners list belong to the same net - the
  64          * one this bucket belongs to.
  65          */
  66
  67         sk_for_each_bound(sk2, node, &tb->owners) {
  68                 if (sk != sk2 &&
  69                     !inet_v6_ipv6only(sk2) &&
  70                     (!sk->sk_bound_dev_if ||
  71                      !sk2->sk_bound_dev_if ||
  72                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  73                         if (!reuse || !sk2->sk_reuse ||
  74                             sk2->sk_state == TCP_LISTEN) {
  75                                 const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
  76                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
  77                                     sk2_rcv_saddr == sk_rcv_saddr)
  78                                         break;
  79                         }
  80                 }
  81         }
  82         return node != NULL;
  83 }
  84
  85 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  86
  87 /* Obtain a reference to a local port for the given sock,
  88  * if snum is zero it means select any available local port.
  89  */
  90 int inet_csk_get_port(struct sock *sk, unsigned short snum)
  91 {
  92         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
  93         struct inet_bind_hashbucket *head;
  94         struct hlist_node *node;
  95         struct inet_bind_bucket *tb;
  96         int ret;
  97         struct net *net = sock_net(sk);
  98
  99         local_bh_disable();
 100         if (!snum) {
 101                 int remaining, rover, low, high;
 102
 103                 inet_get_local_port_range(&low, &high);
 104                 remaining = (high - low) + 1;
 105                 rover = net_random() % remaining + low;
 106
 107                 do {
 108                         head = &hashinfo->bhash[inet_bhashfn(net, rover,
 109                                         hashinfo->bhash_size)];
 110                         spin_lock(&head->lock);
 111                         inet_bind_bucket_for_each(tb, node, &head->chain)
 112                                 if (ib_net(tb) == net && tb->port == rover)
 113                                         goto next;
 114                         break;
 115                 next:
 116                         spin_unlock(&head->lock);
 117                         if (++rover > high)
 118                                 rover = low;
 119                 } while (--remaining > 0);
 120
 121                 /* Exhausted local port range during search?  It is not
 122                  * possible for us to be holding one of the bind hash
 123                  * locks if this test triggers, because if 'remaining'
 124                  * drops to zero, we broke out of the do/while loop at
 125                  * the top level, not from the 'break;' statement.
 126                  */
 127                 ret = 1;
 128                 if (remaining <= 0)
 129                         goto fail;
 130
 131                 /* OK, here is the one we will use.  HEAD is
 132                  * non-NULL and we hold it's mutex.
 133                  */
 134                 snum = rover;
 135         } else {
 136                 head = &hashinfo->bhash[inet_bhashfn(net, snum,
 137                                 hashinfo->bhash_size)];
 138                 spin_lock(&head->lock);
 139                 inet_bind_bucket_for_each(tb, node, &head->chain)
 140                         if (ib_net(tb) == net && tb->port == snum)
 141                                 goto tb_found;
 142         }
 143         tb = NULL;
 144         goto tb_not_found;
 145 tb_found:
 146         if (!hlist_empty(&tb->owners)) {
 147                 if (tb->fastreuse > 0 &&
 148                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 149                         goto success;
 150                 } else {
 151                         ret = 1;
 152                         if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb))
 153                                 goto fail_unlock;
 154                 }
 155         }
 156 tb_not_found:
 157         ret = 1;
 158         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
 159                                         net, head, snum)) == NULL)
 160                 goto fail_unlock;
 161         if (hlist_empty(&tb->owners)) {
 162                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 163                         tb->fastreuse = 1;
 164                 else
 165                         tb->fastreuse = 0;
 166         } else if (tb->fastreuse &&
 167                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 168                 tb->fastreuse = 0;
 169 success:
 170         if (!inet_csk(sk)->icsk_bind_hash)
 171                 inet_bind_hash(sk, tb, snum);
 172         WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
 173         ret = 0;
 174
 175 fail_unlock:
 176         spin_unlock(&head->lock);
 177 fail:
 178         local_bh_enable();
 179         return ret;
 180 }
 181
 182 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 183
 184 /*
 185  * Wait for an incoming connection, avoid race conditions. This must be called
 186  * with the socket locked.
 187  */
 188 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 189 {
 190         struct inet_connection_sock *icsk = inet_csk(sk);
 191         DEFINE_WAIT(wait);
 192         int err;
 193
 194         /*
 195          * True wake-one mechanism for incoming connections: only
 196          * one process gets woken up, not the 'whole herd'.
 197          * Since we do not 'race & poll' for established sockets
 198          * anymore, the common case will execute the loop only once.
 199          *
 200          * Subtle issue: "add_wait_queue_exclusive()" will be added
 201          * after any current non-exclusive waiters, and we know that
 202          * it will always _stay_ after any new non-exclusive waiters
 203          * because all non-exclusive waiters are added at the
 204          * beginning of the wait-queue. As such, it's ok to "drop"
 205          * our exclusiveness temporarily when we get woken up without
 206          * having to remove and re-insert us on the wait queue.
 207          */
 208         for (;;) {
 209                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 210                                           TASK_INTERRUPTIBLE);
 211                 release_sock(sk);
 212                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 213                         timeo = schedule_timeout(timeo);
 214                 lock_sock(sk);
 215                 err = 0;
 216                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 217                         break;
 218                 err = -EINVAL;
 219                 if (sk->sk_state != TCP_LISTEN)
 220                         break;
 221                 err = sock_intr_errno(timeo);
 222                 if (signal_pending(current))
 223                         break;
 224                 err = -EAGAIN;
 225                 if (!timeo)
 226                         break;
 227         }
 228         finish_wait(sk->sk_sleep, &wait);
 229         return err;
 230 }
 231
 232 /*
 233  * This will accept the next outstanding connection.
 234  */
 235 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 236 {
 237         struct inet_connection_sock *icsk = inet_csk(sk);
 238         struct sock *newsk;
 239         int error;
 240
 241         lock_sock(sk);
 242
 243         /* We need to make sure that this socket is listening,
 244          * and that it has something pending.
 245          */
 246         error = -EINVAL;
 247         if (sk->sk_state != TCP_LISTEN)
 248                 goto out_err;
 249
 250         /* Find already established connection */
 251         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 252                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 253
 254                 /* If this is a non blocking socket don't sleep */
 255                 error = -EAGAIN;
 256                 if (!timeo)
 257                         goto out_err;
 258
 259                 error = inet_csk_wait_for_connect(sk, timeo);
 260                 if (error)
 261                         goto out_err;
 262         }
 263
 264         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 265         WARN_ON(newsk->sk_state == TCP_SYN_RECV);
 266 out:
 267         release_sock(sk);
 268         return newsk;
 269 out_err:
 270         newsk = NULL;
 271         *err = error;
 272         goto out;
 273 }
 274
 275 EXPORT_SYMBOL(inet_csk_accept);
 276
 277 /*
 278  * Using different timers for retransmit, delayed acks and probes
 279  * We may wish use just one timer maintaining a list of expire jiffies
 280  * to optimize.
 281  */
 282 void inet_csk_init_xmit_timers(struct sock *sk,
 283                                void (*retransmit_handler)(unsigned long),
 284                                void (*delack_handler)(unsigned long),
 285                                void (*keepalive_handler)(unsigned long))
 286 {
 287         struct inet_connection_sock *icsk = inet_csk(sk);
 288
 289         setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
 290                         (unsigned long)sk);
 291         setup_timer(&icsk->icsk_delack_timer, delack_handler,
 292                         (unsigned long)sk);
 293         setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
 294         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 295 }
 296
 297 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 298
 299 void inet_csk_clear_xmit_timers(struct sock *sk)
 300 {
 301         struct inet_connection_sock *icsk = inet_csk(sk);
 302
 303         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 304
 305         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 306         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 307         sk_stop_timer(sk, &sk->sk_timer);
 308 }
 309
 310 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 311
 312 void inet_csk_delete_keepalive_timer(struct sock *sk)
 313 {
 314         sk_stop_timer(sk, &sk->sk_timer);
 315 }
 316
 317 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 318
 319 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 320 {
 321         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 322 }
 323
 324 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 325
 326 struct dst_entry *inet_csk_route_req(struct sock *sk,
 327                                      const struct request_sock *req)
 328 {
 329         struct rtable *rt;
 330         const struct inet_request_sock *ireq = inet_rsk(req);
 331         struct ip_options *opt = inet_rsk(req)->opt;
 332         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 333                             .nl_u = { .ip4_u =
 334                                       { .daddr = ((opt && opt->srr) ?
 335                                                   opt->faddr :
 336                                                   ireq->rmt_addr),
 337                                         .saddr = ireq->loc_addr,
 338                                         .tos = RT_CONN_FLAGS(sk) } },
 339                             .proto = sk->sk_protocol,
 340                             .flags = inet_sk_flowi_flags(sk),
 341                             .uli_u = { .ports =
 342                                        { .sport = inet_sk(sk)->sport,
 343                                          .dport = ireq->rmt_port } } };
 344         struct net *net = sock_net(sk);
 345
 346         security_req_classify_flow(req, &fl);
 347         if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
 348                 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
 349                 return NULL;
 350         }
 351         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 352                 ip_rt_put(rt);
 353                 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
 354                 return NULL;
 355         }
 356         return &rt->u.dst;
 357 }
 358
 359 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 360
 361 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
 362                                  const u32 rnd, const u32 synq_hsize)
 363 {
 364         return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
 365 }
 366
 367 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 368 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 369 #else
 370 #define AF_INET_FAMILY(fam) 1
 371 #endif
 372
 373 struct request_sock *inet_csk_search_req(const struct sock *sk,
 374                                          struct request_sock ***prevp,
 375                                          const __be16 rport, const __be32 raddr,
 376                                          const __be32 laddr)
 377 {
 378         const struct inet_connection_sock *icsk = inet_csk(sk);
 379         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 380         struct request_sock *req, **prev;
 381
 382         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 383                                                     lopt->nr_table_entries)];
 384              (req = *prev) != NULL;
 385              prev = &req->dl_next) {
 386                 const struct inet_request_sock *ireq = inet_rsk(req);
 387
 388                 if (ireq->rmt_port == rport &&
 389                     ireq->rmt_addr == raddr &&
 390                     ireq->loc_addr == laddr &&
 391                     AF_INET_FAMILY(req->rsk_ops->family)) {
 392                         WARN_ON(req->sk);
 393                         *prevp = prev;
 394                         break;
 395                 }
 396         }
 397
 398         return req;
 399 }
 400
 401 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 402
 403 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 404                                    unsigned long timeout)
 405 {
 406         struct inet_connection_sock *icsk = inet_csk(sk);
 407         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 408         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 409                                      lopt->hash_rnd, lopt->nr_table_entries);
 410
 411         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 412         inet_csk_reqsk_queue_added(sk, timeout);
 413 }
 414
 415 /* Only thing we need from tcp.h */
 416 extern int sysctl_tcp_synack_retries;
 417
 418 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 419
 420 void inet_csk_reqsk_queue_prune(struct sock *parent,
 421                                 const unsigned long interval,
 422                                 const unsigned long timeout,
 423                                 const unsigned long max_rto)
 424 {
 425         struct inet_connection_sock *icsk = inet_csk(parent);
 426         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 427         struct listen_sock *lopt = queue->listen_opt;
 428         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 429         int thresh = max_retries;
 430         unsigned long now = jiffies;
 431         struct request_sock **reqp, *req;
 432         int i, budget;
 433
 434         if (lopt == NULL || lopt->qlen == 0)
 435                 return;
 436
 437         /* Normally all the openreqs are young and become mature
 438          * (i.e. converted to established socket) for first timeout.
 439          * If synack was not acknowledged for 3 seconds, it means
 440          * one of the following things: synack was lost, ack was lost,
 441          * rtt is high or nobody planned to ack (i.e. synflood).
 442          * When server is a bit loaded, queue is populated with old
 443          * open requests, reducing effective size of queue.
 444          * When server is well loaded, queue size reduces to zero
 445          * after several minutes of work. It is not synflood,
 446          * it is normal operation. The solution is pruning
 447          * too old entries overriding normal timeout, when
 448          * situation becomes dangerous.
 449          *
 450          * Essentially, we reserve half of room for young
 451          * embrions; and abort old ones without pity, if old
 452          * ones are about to clog our table.
 453          */
 454         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 455                 int young = (lopt->qlen_young<<1);
 456
 457                 while (thresh > 2) {
 458                         if (lopt->qlen < young)
 459                                 break;
 460                         thresh--;
 461                         young <<= 1;
 462                 }
 463         }
 464
 465         if (queue->rskq_defer_accept)
 466                 max_retries = queue->rskq_defer_accept;
 467
 468         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 469         i = lopt->clock_hand;
 470
 471         do {
 472                 reqp=&lopt->syn_table[i];
 473                 while ((req = *reqp) != NULL) {
 474                         if (time_after_eq(now, req->expires)) {
 475                                 if ((req->retrans < thresh ||
 476                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 477                                     && !req->rsk_ops->rtx_syn_ack(parent, req)) {
 478                                         unsigned long timeo;
 479
 480                                         if (req->retrans++ == 0)
 481                                                 lopt->qlen_young--;
 482                                         timeo = min((timeout << req->retrans), max_rto);
 483                                         req->expires = now + timeo;
 484                                         reqp = &req->dl_next;
 485                                         continue;
 486                                 }
 487
 488                                 /* Drop this request */
 489                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 490                                 reqsk_queue_removed(queue, req);
 491                                 reqsk_free(req);
 492                                 continue;
 493                         }
 494                         reqp = &req->dl_next;
 495                 }
 496
 497                 i = (i + 1) & (lopt->nr_table_entries - 1);
 498
 499         } while (--budget > 0);
 500
 501         lopt->clock_hand = i;
 502
 503         if (lopt->qlen)
 504                 inet_csk_reset_keepalive_timer(parent, interval);
 505 }
 506
 507 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 508
 509 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 510                             const gfp_t priority)
 511 {
 512         struct sock *newsk = sk_clone(sk, priority);
 513
 514         if (newsk != NULL) {
 515                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 516
 517                 newsk->sk_state = TCP_SYN_RECV;
 518                 newicsk->icsk_bind_hash = NULL;
 519
 520                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 521                 inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
 522                 inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
 523                 newsk->sk_write_space = sk_stream_write_space;
 524
 525                 newicsk->icsk_retransmits = 0;
 526                 newicsk->icsk_backoff     = 0;
 527                 newicsk->icsk_probes_out  = 0;
 528
 529                 /* Deinitialize accept_queue to trap illegal accesses. */
 530                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 531
 532                 security_inet_csk_clone(newsk, req);
 533         }
 534         return newsk;
 535 }
 536
 537 EXPORT_SYMBOL_GPL(inet_csk_clone);
 538
 539 /*
 540  * At this point, there should be no process reference to this
 541  * socket, and thus no user references at all.  Therefore we
 542  * can assume the socket waitqueue is inactive and nobody will
 543  * try to jump onto it.
 544  */
 545 void inet_csk_destroy_sock(struct sock *sk)
 546 {
 547         WARN_ON(sk->sk_state != TCP_CLOSE);
 548         WARN_ON(!sock_flag(sk, SOCK_DEAD));
 549
 550         /* It cannot be in hash table! */
 551         WARN_ON(!sk_unhashed(sk));
 552
 553         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 554         WARN_ON(inet_sk(sk)->num && !inet_csk(sk)->icsk_bind_hash);
 555
 556         sk->sk_prot->destroy(sk);
 557
 558         sk_stream_kill_queues(sk);
 559
 560         xfrm_sk_free_policy(sk);
 561
 562         sk_refcnt_debug_release(sk);
 563
 564         percpu_counter_dec(sk->sk_prot->orphan_count);
 565         sock_put(sk);
 566 }
 567
 568 EXPORT_SYMBOL(inet_csk_destroy_sock);
 569
 570 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 571 {
 572         struct inet_sock *inet = inet_sk(sk);
 573         struct inet_connection_sock *icsk = inet_csk(sk);
 574         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 575
 576         if (rc != 0)
 577                 return rc;
 578
 579         sk->sk_max_ack_backlog = 0;
 580         sk->sk_ack_backlog = 0;
 581         inet_csk_delack_init(sk);
 582
 583         /* There is race window here: we announce ourselves listening,
 584          * but this transition is still not validated by get_port().
 585          * It is OK, because this socket enters to hash table only
 586          * after validation is complete.
 587          */
 588         sk->sk_state = TCP_LISTEN;
 589         if (!sk->sk_prot->get_port(sk, inet->num)) {
 590                 inet->sport = htons(inet->num);
 591
 592                 sk_dst_reset(sk);
 593                 sk->sk_prot->hash(sk);
 594
 595                 return 0;
 596         }
 597
 598         sk->sk_state = TCP_CLOSE;
 599         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 600         return -EADDRINUSE;
 601 }
 602
 603 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 604
 605 /*
 606  *      This routine closes sockets which have been at least partially
 607  *      opened, but not yet accepted.
 608  */
 609 void inet_csk_listen_stop(struct sock *sk)
 610 {
 611         struct inet_connection_sock *icsk = inet_csk(sk);
 612         struct request_sock *acc_req;
 613         struct request_sock *req;
 614
 615         inet_csk_delete_keepalive_timer(sk);
 616
 617         /* make all the listen_opt local to us */
 618         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 619
 620         /* Following specs, it would be better either to send FIN
 621          * (and enter FIN-WAIT-1, it is normal close)
 622          * or to send active reset (abort).
 623          * Certainly, it is pretty dangerous while synflood, but it is
 624          * bad justification for our negligence 8)
 625          * To be honest, we are not able to make either
 626          * of the variants now.                 --ANK
 627          */
 628         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 629
 630         while ((req = acc_req) != NULL) {
 631                 struct sock *child = req->sk;
 632
 633                 acc_req = req->dl_next;
 634
 635                 local_bh_disable();
 636                 bh_lock_sock(child);
 637                 WARN_ON(sock_owned_by_user(child));
 638                 sock_hold(child);
 639
 640                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 641
 642                 sock_orphan(child);
 643
 644                 percpu_counter_inc(sk->sk_prot->orphan_count);
 645
 646                 inet_csk_destroy_sock(child);
 647
 648                 bh_unlock_sock(child);
 649                 local_bh_enable();
 650                 sock_put(child);
 651
 652                 sk_acceptq_removed(sk);
 653                 __reqsk_free(req);
 654         }
 655         WARN_ON(sk->sk_ack_backlog);
 656 }
 657
 658 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 659
 660 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 661 {
 662         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 663         const struct inet_sock *inet = inet_sk(sk);
 664
 665         sin->sin_family         = AF_INET;
 666         sin->sin_addr.s_addr    = inet->daddr;
 667         sin->sin_port           = inet->dport;
 668 }
 669
 670 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 671
 672 #ifdef CONFIG_COMPAT
 673 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 674                                char __user *optval, int __user *optlen)
 675 {
 676         const struct inet_connection_sock *icsk = inet_csk(sk);
 677
 678         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 679                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 680                                                             optval, optlen);
 681         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 682                                              optval, optlen);
 683 }
 684
 685 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 686
 687 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 688                                char __user *optval, int optlen)
 689 {
 690         const struct inet_connection_sock *icsk = inet_csk(sk);
 691
 692         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 693                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 694                                                             optval, optlen);
 695         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 696                                              optval, optlen);
 697 }
 698
 699 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 700 #endif