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         struct sock *sk2;
  44         struct hlist_node *node;
  45         int reuse = sk->sk_reuse;
  46
  47         sk_for_each_bound(sk2, node, &tb->owners) {
  48                 if (sk != sk2 &&
  49                     !inet_v6_ipv6only(sk2) &&
  50                     (!sk->sk_bound_dev_if ||
  51                      !sk2->sk_bound_dev_if ||
  52                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  53                         if (!reuse || !sk2->sk_reuse ||
  54                             sk2->sk_state == TCP_LISTEN) {
  55                                 if (nx_addr_conflict(sk->sk_nx_info,
  56                                         inet_rcv_saddr(sk), sk2))
  57                                         break;
  58                         }
  59                 }
  60         }
  61         return node != NULL;
  62 }
  63
  64 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  65
  66 /* Obtain a reference to a local port for the given sock,
  67  * if snum is zero it means select any available local port.
  68  */
  69 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
  70                       struct sock *sk, unsigned short snum,
  71                       int (*bind_conflict)(const struct sock *sk,
  72                                            const struct inet_bind_bucket *tb))
  73 {
  74         struct inet_bind_hashbucket *head;
  75         struct hlist_node *node;
  76         struct inet_bind_bucket *tb;
  77         int ret;
  78
  79         local_bh_disable();
  80         if (!snum) {
  81                 int low = sysctl_local_port_range[0];
  82                 int high = sysctl_local_port_range[1];
  83                 int remaining = (high - low) + 1;
  84                 int rover = net_random() % (high - low) + low;
  85
  86                 do {
  87                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
  88                         spin_lock(&head->lock);
  89                         inet_bind_bucket_for_each(tb, node, &head->chain)
  90                                 if (tb->port == rover)
  91                                         goto next;
  92                         break;
  93                 next:
  94                         spin_unlock(&head->lock);
  95                         if (++rover > high)
  96                                 rover = low;
  97                 } while (--remaining > 0);
  98
  99                 /* Exhausted local port range during search?  It is not
 100                  * possible for us to be holding one of the bind hash
 101                  * locks if this test triggers, because if 'remaining'
 102                  * drops to zero, we broke out of the do/while loop at
 103                  * the top level, not from the 'break;' statement.
 104                  */
 105                 ret = 1;
 106                 if (remaining <= 0)
 107                         goto fail;
 108
 109                 /* OK, here is the one we will use.  HEAD is
 110                  * non-NULL and we hold it's mutex.
 111                  */
 112                 snum = rover;
 113         } else {
 114                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 115                 spin_lock(&head->lock);
 116                 inet_bind_bucket_for_each(tb, node, &head->chain)
 117                         if (tb->port == snum)
 118                                 goto tb_found;
 119         }
 120         tb = NULL;
 121         goto tb_not_found;
 122 tb_found:
 123         if (!hlist_empty(&tb->owners)) {
 124                 if (sk->sk_reuse > 1)
 125                         goto success;
 126                 if (tb->fastreuse > 0 &&
 127                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 128                         goto success;
 129                 } else {
 130                         ret = 1;
 131                         if (bind_conflict(sk, tb))
 132                                 goto fail_unlock;
 133                 }
 134         }
 135 tb_not_found:
 136         ret = 1;
 137         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
 138                 goto fail_unlock;
 139         if (hlist_empty(&tb->owners)) {
 140                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 141                         tb->fastreuse = 1;
 142                 else
 143                         tb->fastreuse = 0;
 144         } else if (tb->fastreuse &&
 145                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 146                 tb->fastreuse = 0;
 147 success:
 148         if (!inet_csk(sk)->icsk_bind_hash)
 149                 inet_bind_hash(sk, tb, snum);
 150         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 151         ret = 0;
 152
 153 fail_unlock:
 154         spin_unlock(&head->lock);
 155 fail:
 156         local_bh_enable();
 157         return ret;
 158 }
 159
 160 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 161
 162 /*
 163  * Wait for an incoming connection, avoid race conditions. This must be called
 164  * with the socket locked.
 165  */
 166 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 167 {
 168         struct inet_connection_sock *icsk = inet_csk(sk);
 169         DEFINE_WAIT(wait);
 170         int err;
 171
 172         /*
 173          * True wake-one mechanism for incoming connections: only
 174          * one process gets woken up, not the 'whole herd'.
 175          * Since we do not 'race & poll' for established sockets
 176          * anymore, the common case will execute the loop only once.
 177          *
 178          * Subtle issue: "add_wait_queue_exclusive()" will be added
 179          * after any current non-exclusive waiters, and we know that
 180          * it will always _stay_ after any new non-exclusive waiters
 181          * because all non-exclusive waiters are added at the
 182          * beginning of the wait-queue. As such, it's ok to "drop"
 183          * our exclusiveness temporarily when we get woken up without
 184          * having to remove and re-insert us on the wait queue.
 185          */
 186         for (;;) {
 187                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 188                                           TASK_INTERRUPTIBLE);
 189                 release_sock(sk);
 190                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 191                         timeo = schedule_timeout(timeo);
 192                 lock_sock(sk);
 193                 err = 0;
 194                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 195                         break;
 196                 err = -EINVAL;
 197                 if (sk->sk_state != TCP_LISTEN)
 198                         break;
 199                 err = sock_intr_errno(timeo);
 200                 if (signal_pending(current))
 201                         break;
 202                 err = -EAGAIN;
 203                 if (!timeo)
 204                         break;
 205         }
 206         finish_wait(sk->sk_sleep, &wait);
 207         return err;
 208 }
 209
 210 /*
 211  * This will accept the next outstanding connection.
 212  */
 213 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 214 {
 215         struct inet_connection_sock *icsk = inet_csk(sk);
 216         struct sock *newsk;
 217         int error;
 218
 219         lock_sock(sk);
 220
 221         /* We need to make sure that this socket is listening,
 222          * and that it has something pending.
 223          */
 224         error = -EINVAL;
 225         if (sk->sk_state != TCP_LISTEN)
 226                 goto out_err;
 227
 228         /* Find already established connection */
 229         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 230                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 231
 232                 /* If this is a non blocking socket don't sleep */
 233                 error = -EAGAIN;
 234                 if (!timeo)
 235                         goto out_err;
 236
 237                 error = inet_csk_wait_for_connect(sk, timeo);
 238                 if (error)
 239                         goto out_err;
 240         }
 241
 242         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 243         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 244 out:
 245         release_sock(sk);
 246         return newsk;
 247 out_err:
 248         newsk = NULL;
 249         *err = error;
 250         goto out;
 251 }
 252
 253 EXPORT_SYMBOL(inet_csk_accept);
 254
 255 /*
 256  * Using different timers for retransmit, delayed acks and probes
 257  * We may wish use just one timer maintaining a list of expire jiffies
 258  * to optimize.
 259  */
 260 void inet_csk_init_xmit_timers(struct sock *sk,
 261                                void (*retransmit_handler)(unsigned long),
 262                                void (*delack_handler)(unsigned long),
 263                                void (*keepalive_handler)(unsigned long))
 264 {
 265         struct inet_connection_sock *icsk = inet_csk(sk);
 266
 267         init_timer(&icsk->icsk_retransmit_timer);
 268         init_timer(&icsk->icsk_delack_timer);
 269         init_timer(&sk->sk_timer);
 270
 271         icsk->icsk_retransmit_timer.function = retransmit_handler;
 272         icsk->icsk_delack_timer.function     = delack_handler;
 273         sk->sk_timer.function                = keepalive_handler;
 274
 275         icsk->icsk_retransmit_timer.data =
 276                 icsk->icsk_delack_timer.data =
 277                         sk->sk_timer.data  = (unsigned long)sk;
 278
 279         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 280 }
 281
 282 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 283
 284 void inet_csk_clear_xmit_timers(struct sock *sk)
 285 {
 286         struct inet_connection_sock *icsk = inet_csk(sk);
 287
 288         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 289
 290         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 291         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 292         sk_stop_timer(sk, &sk->sk_timer);
 293 }
 294
 295 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 296
 297 void inet_csk_delete_keepalive_timer(struct sock *sk)
 298 {
 299         sk_stop_timer(sk, &sk->sk_timer);
 300 }
 301
 302 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 303
 304 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 305 {
 306         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 307 }
 308
 309 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 310
 311 struct dst_entry* inet_csk_route_req(struct sock *sk,
 312                                      const struct request_sock *req)
 313 {
 314         struct rtable *rt;
 315         const struct inet_request_sock *ireq = inet_rsk(req);
 316         struct ip_options *opt = inet_rsk(req)->opt;
 317         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 318                             .nl_u = { .ip4_u =
 319                                       { .daddr = ((opt && opt->srr) ?
 320                                                   opt->faddr :
 321                                                   ireq->rmt_addr),
 322                                         .saddr = ireq->loc_addr,
 323                                         .tos = RT_CONN_FLAGS(sk) } },
 324                             .proto = sk->sk_protocol,
 325                             .uli_u = { .ports =
 326                                        { .sport = inet_sk(sk)->sport,
 327                                          .dport = ireq->rmt_port } } };
 328
 329         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 330                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 331                 return NULL;
 332         }
 333         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 334                 ip_rt_put(rt);
 335                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 336                 return NULL;
 337         }
 338         return &rt->u.dst;
 339 }
 340
 341 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 342
 343 static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
 344                                  const u32 rnd, const u16 synq_hsize)
 345 {
 346         return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
 347 }
 348
 349 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 350 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 351 #else
 352 #define AF_INET_FAMILY(fam) 1
 353 #endif
 354
 355 struct request_sock *inet_csk_search_req(const struct sock *sk,
 356                                          struct request_sock ***prevp,
 357                                          const __u16 rport, const __u32 raddr,
 358                                          const __u32 laddr)
 359 {
 360         const struct inet_connection_sock *icsk = inet_csk(sk);
 361         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 362         struct request_sock *req, **prev;
 363
 364         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 365                                                     lopt->nr_table_entries)];
 366              (req = *prev) != NULL;
 367              prev = &req->dl_next) {
 368                 const struct inet_request_sock *ireq = inet_rsk(req);
 369
 370                 if (ireq->rmt_port == rport &&
 371                     ireq->rmt_addr == raddr &&
 372                     ireq->loc_addr == laddr &&
 373                     AF_INET_FAMILY(req->rsk_ops->family)) {
 374                         BUG_TRAP(!req->sk);
 375                         *prevp = prev;
 376                         break;
 377                 }
 378         }
 379
 380         return req;
 381 }
 382
 383 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 384
 385 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 386                                    unsigned long timeout)
 387 {
 388         struct inet_connection_sock *icsk = inet_csk(sk);
 389         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 390         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 391                                      lopt->hash_rnd, lopt->nr_table_entries);
 392
 393         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 394         inet_csk_reqsk_queue_added(sk, timeout);
 395 }
 396
 397 /* Only thing we need from tcp.h */
 398 extern int sysctl_tcp_synack_retries;
 399
 400 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 401
 402 void inet_csk_reqsk_queue_prune(struct sock *parent,
 403                                 const unsigned long interval,
 404                                 const unsigned long timeout,
 405                                 const unsigned long max_rto)
 406 {
 407         struct inet_connection_sock *icsk = inet_csk(parent);
 408         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 409         struct listen_sock *lopt = queue->listen_opt;
 410         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 411         int thresh = max_retries;
 412         unsigned long now = jiffies;
 413         struct request_sock **reqp, *req;
 414         int i, budget;
 415
 416         if (lopt == NULL || lopt->qlen == 0)
 417                 return;
 418
 419         /* Normally all the openreqs are young and become mature
 420          * (i.e. converted to established socket) for first timeout.
 421          * If synack was not acknowledged for 3 seconds, it means
 422          * one of the following things: synack was lost, ack was lost,
 423          * rtt is high or nobody planned to ack (i.e. synflood).
 424          * When server is a bit loaded, queue is populated with old
 425          * open requests, reducing effective size of queue.
 426          * When server is well loaded, queue size reduces to zero
 427          * after several minutes of work. It is not synflood,
 428          * it is normal operation. The solution is pruning
 429          * too old entries overriding normal timeout, when
 430          * situation becomes dangerous.
 431          *
 432          * Essentially, we reserve half of room for young
 433          * embrions; and abort old ones without pity, if old
 434          * ones are about to clog our table.
 435          */
 436         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 437                 int young = (lopt->qlen_young<<1);
 438
 439                 while (thresh > 2) {
 440                         if (lopt->qlen < young)
 441                                 break;
 442                         thresh--;
 443                         young <<= 1;
 444                 }
 445         }
 446
 447         if (queue->rskq_defer_accept)
 448                 max_retries = queue->rskq_defer_accept;
 449
 450         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 451         i = lopt->clock_hand;
 452
 453         do {
 454                 reqp=&lopt->syn_table[i];
 455                 while ((req = *reqp) != NULL) {
 456                         if (time_after_eq(now, req->expires)) {
 457                                 if ((req->retrans < thresh ||
 458                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 459                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 460                                         unsigned long timeo;
 461
 462                                         if (req->retrans++ == 0)
 463                                                 lopt->qlen_young--;
 464                                         timeo = min((timeout << req->retrans), max_rto);
 465                                         req->expires = now + timeo;
 466                                         reqp = &req->dl_next;
 467                                         continue;
 468                                 }
 469
 470                                 /* Drop this request */
 471                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 472                                 reqsk_queue_removed(queue, req);
 473                                 reqsk_free(req);
 474                                 continue;
 475                         }
 476                         reqp = &req->dl_next;
 477                 }
 478
 479                 i = (i + 1) & (lopt->nr_table_entries - 1);
 480
 481         } while (--budget > 0);
 482
 483         lopt->clock_hand = i;
 484
 485         if (lopt->qlen)
 486                 inet_csk_reset_keepalive_timer(parent, interval);
 487 }
 488
 489 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 490
 491 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 492                             const gfp_t priority)
 493 {
 494         struct sock *newsk = sk_clone(sk, priority);
 495
 496         if (newsk != NULL) {
 497                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 498
 499                 newsk->sk_state = TCP_SYN_RECV;
 500                 newicsk->icsk_bind_hash = NULL;
 501
 502                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 503                 newsk->sk_write_space = sk_stream_write_space;
 504
 505                 newicsk->icsk_retransmits = 0;
 506                 newicsk->icsk_backoff     = 0;
 507                 newicsk->icsk_probes_out  = 0;
 508
 509                 /* Deinitialize accept_queue to trap illegal accesses. */
 510                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 511         }
 512         return newsk;
 513 }
 514
 515 EXPORT_SYMBOL_GPL(inet_csk_clone);
 516
 517 /*
 518  * At this point, there should be no process reference to this
 519  * socket, and thus no user references at all.  Therefore we
 520  * can assume the socket waitqueue is inactive and nobody will
 521  * try to jump onto it.
 522  */
 523 void inet_csk_destroy_sock(struct sock *sk)
 524 {
 525         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 526         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 527
 528         /* It cannot be in hash table! */
 529         BUG_TRAP(sk_unhashed(sk));
 530
 531         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 532         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 533
 534         sk->sk_prot->destroy(sk);
 535
 536         sk_stream_kill_queues(sk);
 537
 538         xfrm_sk_free_policy(sk);
 539
 540         sk_refcnt_debug_release(sk);
 541
 542         atomic_dec(sk->sk_prot->orphan_count);
 543         sock_put(sk);
 544 }
 545
 546 EXPORT_SYMBOL(inet_csk_destroy_sock);
 547
 548 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 549 {
 550         struct inet_sock *inet = inet_sk(sk);
 551         struct inet_connection_sock *icsk = inet_csk(sk);
 552         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 553
 554         if (rc != 0)
 555                 return rc;
 556
 557         sk->sk_max_ack_backlog = 0;
 558         sk->sk_ack_backlog = 0;
 559         inet_csk_delack_init(sk);
 560
 561         /* There is race window here: we announce ourselves listening,
 562          * but this transition is still not validated by get_port().
 563          * It is OK, because this socket enters to hash table only
 564          * after validation is complete.
 565          */
 566         sk->sk_state = TCP_LISTEN;
 567         if (!sk->sk_prot->get_port(sk, inet->num)) {
 568                 inet->sport = htons(inet->num);
 569
 570                 sk_dst_reset(sk);
 571                 sk->sk_prot->hash(sk);
 572
 573                 return 0;
 574         }
 575
 576         sk->sk_state = TCP_CLOSE;
 577         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 578         return -EADDRINUSE;
 579 }
 580
 581 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 582
 583 /*
 584  *      This routine closes sockets which have been at least partially
 585  *      opened, but not yet accepted.
 586  */
 587 void inet_csk_listen_stop(struct sock *sk)
 588 {
 589         struct inet_connection_sock *icsk = inet_csk(sk);
 590         struct request_sock *acc_req;
 591         struct request_sock *req;
 592
 593         inet_csk_delete_keepalive_timer(sk);
 594
 595         /* make all the listen_opt local to us */
 596         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 597
 598         /* Following specs, it would be better either to send FIN
 599          * (and enter FIN-WAIT-1, it is normal close)
 600          * or to send active reset (abort).
 601          * Certainly, it is pretty dangerous while synflood, but it is
 602          * bad justification for our negligence 8)
 603          * To be honest, we are not able to make either
 604          * of the variants now.                 --ANK
 605          */
 606         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 607
 608         while ((req = acc_req) != NULL) {
 609                 struct sock *child = req->sk;
 610
 611                 acc_req = req->dl_next;
 612
 613                 local_bh_disable();
 614                 bh_lock_sock(child);
 615                 BUG_TRAP(!sock_owned_by_user(child));
 616                 sock_hold(child);
 617
 618                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 619
 620                 sock_orphan(child);
 621
 622                 atomic_inc(sk->sk_prot->orphan_count);
 623
 624                 inet_csk_destroy_sock(child);
 625
 626                 bh_unlock_sock(child);
 627                 local_bh_enable();
 628                 sock_put(child);
 629
 630                 sk_acceptq_removed(sk);
 631                 __reqsk_free(req);
 632         }
 633         BUG_TRAP(!sk->sk_ack_backlog);
 634 }
 635
 636 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 637
 638 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 639 {
 640         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 641         const struct inet_sock *inet = inet_sk(sk);
 642
 643         sin->sin_family         = AF_INET;
 644         sin->sin_addr.s_addr    = inet->daddr;
 645         sin->sin_port           = inet->dport;
 646 }
 647
 648 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 649
 650 int inet_csk_ctl_sock_create(struct socket **sock, unsigned short family,
 651                              unsigned short type, unsigned char protocol)
 652 {
 653         int rc = sock_create_kern(family, type, protocol, sock);
 654
 655         if (rc == 0) {
 656                 (*sock)->sk->sk_allocation = GFP_ATOMIC;
 657                 inet_sk((*sock)->sk)->uc_ttl = -1;
 658                 /*
 659                  * Unhash it so that IP input processing does not even see it,
 660                  * we do not wish this socket to see incoming packets.
 661                  */
 662                 (*sock)->sk->sk_prot->unhash((*sock)->sk);
 663         }
 664         return rc;
 665 }
 666
 667 EXPORT_SYMBOL_GPL(inet_csk_ctl_sock_create);
 668
 669 #ifdef CONFIG_COMPAT
 670 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 671                                char __user *optval, int __user *optlen)
 672 {
 673         const struct inet_connection_sock *icsk = inet_csk(sk);
 674
 675         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 676                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 677                                                             optval, optlen);
 678         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 679                                              optval, optlen);
 680 }
 681
 682 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 683
 684 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 685                                char __user *optval, int optlen)
 686 {
 687         const struct inet_connection_sock *icsk = inet_csk(sk);
 688
 689         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 690                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 691                                                             optval, optlen);
 692         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 693                                              optval, optlen);
 694 }
 695
 696 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 697 #endif