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/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, attempts = 5;
  97         struct net *net = sock_net(sk);
  98         int smallest_size = -1, smallest_rover;
  99
 100         local_bh_disable();
 101         if (!snum) {
 102                 int remaining, rover, low, high;
 103
 104 again:
 105                 inet_get_local_port_range(&low, &high);
 106                 remaining = (high - low) + 1;
 107                 smallest_rover = rover = net_random() % remaining + low;
 108
 109                 smallest_size = -1;
 110                 do {
 111                         head = &hashinfo->bhash[inet_bhashfn(net, rover,
 112                                         hashinfo->bhash_size)];
 113                         spin_lock(&head->lock);
 114                         inet_bind_bucket_for_each(tb, node, &head->chain)
 115                                 if (ib_net(tb) == net && tb->port == rover) {
 116                                         if (tb->fastreuse > 0 &&
 117                                             sk->sk_reuse &&
 118                                             sk->sk_state != TCP_LISTEN &&
 119                                             (tb->num_owners < smallest_size || smallest_size == -1)) {
 120                                                 smallest_size = tb->num_owners;
 121                                                 smallest_rover = rover;
 122                                                 if (hashinfo->bsockets > (high - low) + 1) {
 123                                                         spin_unlock(&head->lock);
 124                                                         snum = smallest_rover;
 125                                                         goto have_snum;
 126                                                 }
 127                                         }
 128                                         goto next;
 129                                 }
 130                         break;
 131                 next:
 132                         spin_unlock(&head->lock);
 133                         if (++rover > high)
 134                                 rover = low;
 135                 } while (--remaining > 0);
 136
 137                 /* Exhausted local port range during search?  It is not
 138                  * possible for us to be holding one of the bind hash
 139                  * locks if this test triggers, because if 'remaining'
 140                  * drops to zero, we broke out of the do/while loop at
 141                  * the top level, not from the 'break;' statement.
 142                  */
 143                 ret = 1;
 144                 if (remaining <= 0) {
 145                         if (smallest_size != -1) {
 146                                 snum = smallest_rover;
 147                                 goto have_snum;
 148                         }
 149                         goto fail;
 150                 }
 151                 /* OK, here is the one we will use.  HEAD is
 152                  * non-NULL and we hold it's mutex.
 153                  */
 154                 snum = rover;
 155         } else {
 156 have_snum:
 157                 head = &hashinfo->bhash[inet_bhashfn(net, snum,
 158                                 hashinfo->bhash_size)];
 159                 spin_lock(&head->lock);
 160                 inet_bind_bucket_for_each(tb, node, &head->chain)
 161                         if (ib_net(tb) == net && tb->port == snum)
 162                                 goto tb_found;
 163         }
 164         tb = NULL;
 165         goto tb_not_found;
 166 tb_found:
 167         if (!hlist_empty(&tb->owners)) {
 168                 if (tb->fastreuse > 0 &&
 169                     sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
 170                     smallest_size == -1) {
 171                         goto success;
 172                 } else {
 173                         ret = 1;
 174                         if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
 175                                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && --attempts >= 0) {
 176                                         spin_unlock(&head->lock);
 177                                         goto again;
 178                                 }
 179                                 goto fail_unlock;
 180                         }
 181                 }
 182         }
 183 tb_not_found:
 184         ret = 1;
 185         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
 186                                         net, head, snum)) == NULL)
 187                 goto fail_unlock;
 188         if (hlist_empty(&tb->owners)) {
 189                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 190                         tb->fastreuse = 1;
 191                 else
 192                         tb->fastreuse = 0;
 193         } else if (tb->fastreuse &&
 194                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 195                 tb->fastreuse = 0;
 196 success:
 197         if (!inet_csk(sk)->icsk_bind_hash)
 198                 inet_bind_hash(sk, tb, snum);
 199         WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
 200         ret = 0;
 201
 202 fail_unlock:
 203         spin_unlock(&head->lock);
 204 fail:
 205         local_bh_enable();
 206         return ret;
 207 }
 208
 209 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 210
 211 /*
 212  * Wait for an incoming connection, avoid race conditions. This must be called
 213  * with the socket locked.
 214  */
 215 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 216 {
 217         struct inet_connection_sock *icsk = inet_csk(sk);
 218         DEFINE_WAIT(wait);
 219         int err;
 220
 221         /*
 222          * True wake-one mechanism for incoming connections: only
 223          * one process gets woken up, not the 'whole herd'.
 224          * Since we do not 'race & poll' for established sockets
 225          * anymore, the common case will execute the loop only once.
 226          *
 227          * Subtle issue: "add_wait_queue_exclusive()" will be added
 228          * after any current non-exclusive waiters, and we know that
 229          * it will always _stay_ after any new non-exclusive waiters
 230          * because all non-exclusive waiters are added at the
 231          * beginning of the wait-queue. As such, it's ok to "drop"
 232          * our exclusiveness temporarily when we get woken up without
 233          * having to remove and re-insert us on the wait queue.
 234          */
 235         for (;;) {
 236                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 237                                           TASK_INTERRUPTIBLE);
 238                 release_sock(sk);
 239                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 240                         timeo = schedule_timeout(timeo);
 241                 lock_sock(sk);
 242                 err = 0;
 243                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 244                         break;
 245                 err = -EINVAL;
 246                 if (sk->sk_state != TCP_LISTEN)
 247                         break;
 248                 err = sock_intr_errno(timeo);
 249                 if (signal_pending(current))
 250                         break;
 251                 err = -EAGAIN;
 252                 if (!timeo)
 253                         break;
 254         }
 255         finish_wait(sk->sk_sleep, &wait);
 256         return err;
 257 }
 258
 259 /*
 260  * This will accept the next outstanding connection.
 261  */
 262 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 263 {
 264         struct inet_connection_sock *icsk = inet_csk(sk);
 265         struct sock *newsk;
 266         int error;
 267
 268         lock_sock(sk);
 269
 270         /* We need to make sure that this socket is listening,
 271          * and that it has something pending.
 272          */
 273         error = -EINVAL;
 274         if (sk->sk_state != TCP_LISTEN)
 275                 goto out_err;
 276
 277         /* Find already established connection */
 278         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 279                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 280
 281                 /* If this is a non blocking socket don't sleep */
 282                 error = -EAGAIN;
 283                 if (!timeo)
 284                         goto out_err;
 285
 286                 error = inet_csk_wait_for_connect(sk, timeo);
 287                 if (error)
 288                         goto out_err;
 289         }
 290
 291         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 292         WARN_ON(newsk->sk_state == TCP_SYN_RECV);
 293 out:
 294         release_sock(sk);
 295         return newsk;
 296 out_err:
 297         newsk = NULL;
 298         *err = error;
 299         goto out;
 300 }
 301
 302 EXPORT_SYMBOL(inet_csk_accept);
 303
 304 /*
 305  * Using different timers for retransmit, delayed acks and probes
 306  * We may wish use just one timer maintaining a list of expire jiffies
 307  * to optimize.
 308  */
 309 void inet_csk_init_xmit_timers(struct sock *sk,
 310                                void (*retransmit_handler)(unsigned long),
 311                                void (*delack_handler)(unsigned long),
 312                                void (*keepalive_handler)(unsigned long))
 313 {
 314         struct inet_connection_sock *icsk = inet_csk(sk);
 315
 316         setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
 317                         (unsigned long)sk);
 318         setup_timer(&icsk->icsk_delack_timer, delack_handler,
 319                         (unsigned long)sk);
 320         setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
 321         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 322 }
 323
 324 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 325
 326 void inet_csk_clear_xmit_timers(struct sock *sk)
 327 {
 328         struct inet_connection_sock *icsk = inet_csk(sk);
 329
 330         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 331
 332         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 333         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 334         sk_stop_timer(sk, &sk->sk_timer);
 335 }
 336
 337 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 338
 339 void inet_csk_delete_keepalive_timer(struct sock *sk)
 340 {
 341         sk_stop_timer(sk, &sk->sk_timer);
 342 }
 343
 344 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 345
 346 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 347 {
 348         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 349 }
 350
 351 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 352
 353 struct dst_entry *inet_csk_route_req(struct sock *sk,
 354                                      const struct request_sock *req)
 355 {
 356         struct rtable *rt;
 357         const struct inet_request_sock *ireq = inet_rsk(req);
 358         struct ip_options *opt = inet_rsk(req)->opt;
 359         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 360                             .nl_u = { .ip4_u =
 361                                       { .daddr = ((opt && opt->srr) ?
 362                                                   opt->faddr :
 363                                                   ireq->rmt_addr),
 364                                         .saddr = ireq->loc_addr,
 365                                         .tos = RT_CONN_FLAGS(sk) } },
 366                             .proto = sk->sk_protocol,
 367                             .flags = inet_sk_flowi_flags(sk),
 368                             .uli_u = { .ports =
 369                                        { .sport = inet_sk(sk)->sport,
 370                                          .dport = ireq->rmt_port } } };
 371         struct net *net = sock_net(sk);
 372
 373         security_req_classify_flow(req, &fl);
 374         if (ip_route_output_flow(net, &rt, &fl, sk, 0))
 375                 goto no_route;
 376         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
 377                 goto route_err;
 378         return &rt->u.dst;
 379
 380 route_err:
 381         ip_rt_put(rt);
 382 no_route:
 383         IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
 384         return NULL;
 385 }
 386
 387 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 388
 389 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
 390                                  const u32 rnd, const u32 synq_hsize)
 391 {
 392         return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
 393 }
 394
 395 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 396 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 397 #else
 398 #define AF_INET_FAMILY(fam) 1
 399 #endif
 400
 401 struct request_sock *inet_csk_search_req(const struct sock *sk,
 402                                          struct request_sock ***prevp,
 403                                          const __be16 rport, const __be32 raddr,
 404                                          const __be32 laddr)
 405 {
 406         const struct inet_connection_sock *icsk = inet_csk(sk);
 407         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 408         struct request_sock *req, **prev;
 409
 410         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 411                                                     lopt->nr_table_entries)];
 412              (req = *prev) != NULL;
 413              prev = &req->dl_next) {
 414                 const struct inet_request_sock *ireq = inet_rsk(req);
 415
 416                 if (ireq->rmt_port == rport &&
 417                     ireq->rmt_addr == raddr &&
 418                     ireq->loc_addr == laddr &&
 419                     AF_INET_FAMILY(req->rsk_ops->family)) {
 420                         WARN_ON(req->sk);
 421                         *prevp = prev;
 422                         break;
 423                 }
 424         }
 425
 426         return req;
 427 }
 428
 429 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 430
 431 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 432                                    unsigned long timeout)
 433 {
 434         struct inet_connection_sock *icsk = inet_csk(sk);
 435         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 436         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 437                                      lopt->hash_rnd, lopt->nr_table_entries);
 438
 439         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 440         inet_csk_reqsk_queue_added(sk, timeout);
 441 }
 442
 443 /* Only thing we need from tcp.h */
 444 extern int sysctl_tcp_synack_retries;
 445
 446 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 447
 448 void inet_csk_reqsk_queue_prune(struct sock *parent,
 449                                 const unsigned long interval,
 450                                 const unsigned long timeout,
 451                                 const unsigned long max_rto)
 452 {
 453         struct inet_connection_sock *icsk = inet_csk(parent);
 454         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 455         struct listen_sock *lopt = queue->listen_opt;
 456         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 457         int thresh = max_retries;
 458         unsigned long now = jiffies;
 459         struct request_sock **reqp, *req;
 460         int i, budget;
 461
 462         if (lopt == NULL || lopt->qlen == 0)
 463                 return;
 464
 465         /* Normally all the openreqs are young and become mature
 466          * (i.e. converted to established socket) for first timeout.
 467          * If synack was not acknowledged for 3 seconds, it means
 468          * one of the following things: synack was lost, ack was lost,
 469          * rtt is high or nobody planned to ack (i.e. synflood).
 470          * When server is a bit loaded, queue is populated with old
 471          * open requests, reducing effective size of queue.
 472          * When server is well loaded, queue size reduces to zero
 473          * after several minutes of work. It is not synflood,
 474          * it is normal operation. The solution is pruning
 475          * too old entries overriding normal timeout, when
 476          * situation becomes dangerous.
 477          *
 478          * Essentially, we reserve half of room for young
 479          * embrions; and abort old ones without pity, if old
 480          * ones are about to clog our table.
 481          */
 482         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 483                 int young = (lopt->qlen_young<<1);
 484
 485                 while (thresh > 2) {
 486                         if (lopt->qlen < young)
 487                                 break;
 488                         thresh--;
 489                         young <<= 1;
 490                 }
 491         }
 492
 493         if (queue->rskq_defer_accept)
 494                 max_retries = queue->rskq_defer_accept;
 495
 496         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 497         i = lopt->clock_hand;
 498
 499         do {
 500                 reqp=&lopt->syn_table[i];
 501                 while ((req = *reqp) != NULL) {
 502                         if (time_after_eq(now, req->expires)) {
 503                                 if ((req->retrans < thresh ||
 504                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 505                                     && !req->rsk_ops->rtx_syn_ack(parent, req)) {
 506                                         unsigned long timeo;
 507
 508                                         if (req->retrans++ == 0)
 509                                                 lopt->qlen_young--;
 510                                         timeo = min((timeout << req->retrans), max_rto);
 511                                         req->expires = now + timeo;
 512                                         reqp = &req->dl_next;
 513                                         continue;
 514                                 }
 515
 516                                 /* Drop this request */
 517                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 518                                 reqsk_queue_removed(queue, req);
 519                                 reqsk_free(req);
 520                                 continue;
 521                         }
 522                         reqp = &req->dl_next;
 523                 }
 524
 525                 i = (i + 1) & (lopt->nr_table_entries - 1);
 526
 527         } while (--budget > 0);
 528
 529         lopt->clock_hand = i;
 530
 531         if (lopt->qlen)
 532                 inet_csk_reset_keepalive_timer(parent, interval);
 533 }
 534
 535 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 536
 537 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 538                             const gfp_t priority)
 539 {
 540         struct sock *newsk = sk_clone(sk, priority);
 541
 542         if (newsk != NULL) {
 543                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 544
 545                 newsk->sk_state = TCP_SYN_RECV;
 546                 newicsk->icsk_bind_hash = NULL;
 547
 548                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 549                 inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
 550                 inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
 551                 newsk->sk_write_space = sk_stream_write_space;
 552
 553                 newicsk->icsk_retransmits = 0;
 554                 newicsk->icsk_backoff     = 0;
 555                 newicsk->icsk_probes_out  = 0;
 556
 557                 /* Deinitialize accept_queue to trap illegal accesses. */
 558                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 559
 560                 security_inet_csk_clone(newsk, req);
 561         }
 562         return newsk;
 563 }
 564
 565 EXPORT_SYMBOL_GPL(inet_csk_clone);
 566
 567 /*
 568  * At this point, there should be no process reference to this
 569  * socket, and thus no user references at all.  Therefore we
 570  * can assume the socket waitqueue is inactive and nobody will
 571  * try to jump onto it.
 572  */
 573 void inet_csk_destroy_sock(struct sock *sk)
 574 {
 575         WARN_ON(sk->sk_state != TCP_CLOSE);
 576         WARN_ON(!sock_flag(sk, SOCK_DEAD));
 577
 578         /* It cannot be in hash table! */
 579         WARN_ON(!sk_unhashed(sk));
 580
 581         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 582         WARN_ON(inet_sk(sk)->num && !inet_csk(sk)->icsk_bind_hash);
 583
 584         sk->sk_prot->destroy(sk);
 585
 586         sk_stream_kill_queues(sk);
 587
 588         xfrm_sk_free_policy(sk);
 589
 590         sk_refcnt_debug_release(sk);
 591
 592         percpu_counter_dec(sk->sk_prot->orphan_count);
 593         sock_put(sk);
 594 }
 595
 596 EXPORT_SYMBOL(inet_csk_destroy_sock);
 597
 598 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 599 {
 600         struct inet_sock *inet = inet_sk(sk);
 601         struct inet_connection_sock *icsk = inet_csk(sk);
 602         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 603
 604         if (rc != 0)
 605                 return rc;
 606
 607         sk->sk_max_ack_backlog = 0;
 608         sk->sk_ack_backlog = 0;
 609         inet_csk_delack_init(sk);
 610
 611         /* There is race window here: we announce ourselves listening,
 612          * but this transition is still not validated by get_port().
 613          * It is OK, because this socket enters to hash table only
 614          * after validation is complete.
 615          */
 616         sk->sk_state = TCP_LISTEN;
 617         if (!sk->sk_prot->get_port(sk, inet->num)) {
 618                 inet->sport = htons(inet->num);
 619
 620                 sk_dst_reset(sk);
 621                 sk->sk_prot->hash(sk);
 622
 623                 return 0;
 624         }
 625
 626         sk->sk_state = TCP_CLOSE;
 627         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 628         return -EADDRINUSE;
 629 }
 630
 631 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 632
 633 /*
 634  *      This routine closes sockets which have been at least partially
 635  *      opened, but not yet accepted.
 636  */
 637 void inet_csk_listen_stop(struct sock *sk)
 638 {
 639         struct inet_connection_sock *icsk = inet_csk(sk);
 640         struct request_sock *acc_req;
 641         struct request_sock *req;
 642
 643         inet_csk_delete_keepalive_timer(sk);
 644
 645         /* make all the listen_opt local to us */
 646         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 647
 648         /* Following specs, it would be better either to send FIN
 649          * (and enter FIN-WAIT-1, it is normal close)
 650          * or to send active reset (abort).
 651          * Certainly, it is pretty dangerous while synflood, but it is
 652          * bad justification for our negligence 8)
 653          * To be honest, we are not able to make either
 654          * of the variants now.                 --ANK
 655          */
 656         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 657
 658         while ((req = acc_req) != NULL) {
 659                 struct sock *child = req->sk;
 660
 661                 acc_req = req->dl_next;
 662
 663                 local_bh_disable();
 664                 bh_lock_sock(child);
 665                 WARN_ON(sock_owned_by_user(child));
 666                 sock_hold(child);
 667
 668                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 669
 670                 sock_orphan(child);
 671
 672                 percpu_counter_inc(sk->sk_prot->orphan_count);
 673
 674                 inet_csk_destroy_sock(child);
 675
 676                 bh_unlock_sock(child);
 677                 local_bh_enable();
 678                 sock_put(child);
 679
 680                 sk_acceptq_removed(sk);
 681                 __reqsk_free(req);
 682         }
 683         WARN_ON(sk->sk_ack_backlog);
 684 }
 685
 686 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 687
 688 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 689 {
 690         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 691         const struct inet_sock *inet = inet_sk(sk);
 692
 693         sin->sin_family         = AF_INET;
 694         sin->sin_addr.s_addr    = inet->daddr;
 695         sin->sin_port           = inet->dport;
 696 }
 697
 698 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 699
 700 #ifdef CONFIG_COMPAT
 701 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 702                                char __user *optval, int __user *optlen)
 703 {
 704         const struct inet_connection_sock *icsk = inet_csk(sk);
 705
 706         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 707                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 708                                                             optval, optlen);
 709         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 710                                              optval, optlen);
 711 }
 712
 713 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 714
 715 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 716                                char __user *optval, int optlen)
 717 {
 718         const struct inet_connection_sock *icsk = inet_csk(sk);
 719
 720         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 721                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 722                                                             optval, optlen);
 723         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 724                                              optval, optlen);
 725 }
 726
 727 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 728 #endif