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  * For high-usage systems, use sysctl to change this to
  35  * 32768-61000
  36  */
  37 int sysctl_local_port_range[2] = { 1024, 4999 };
  38
  39 int inet_csk_bind_conflict(const struct sock *sk,
  40                            const struct inet_bind_bucket *tb)
  41 {
  42         struct sock *sk2;
  43         struct hlist_node *node;
  44         int reuse = sk->sk_reuse;
  45
  46         sk_for_each_bound(sk2, node, &tb->owners) {
  47                 if (sk != sk2 &&
  48                     !inet_v6_ipv6only(sk2) &&
  49                     (!sk->sk_bound_dev_if ||
  50                      !sk2->sk_bound_dev_if ||
  51                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  52                         if (!reuse || !sk2->sk_reuse ||
  53                             sk2->sk_state == TCP_LISTEN) {
  54                                 if (nx_addr_conflict(sk->sk_nx_info,
  55                                         inet_rcv_saddr(sk), sk2))
  56                                         break;
  57                         }
  58                 }
  59         }
  60         return node != NULL;
  61 }
  62
  63 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  64
  65 /* Obtain a reference to a local port for the given sock,
  66  * if snum is zero it means select any available local port.
  67  */
  68 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
  69                       struct sock *sk, unsigned short snum,
  70                       int (*bind_conflict)(const struct sock *sk,
  71                                            const struct inet_bind_bucket *tb))
  72 {
  73         struct inet_bind_hashbucket *head;
  74         struct hlist_node *node;
  75         struct inet_bind_bucket *tb;
  76         int ret;
  77
  78         local_bh_disable();
  79         if (!snum) {
  80                 int low = sysctl_local_port_range[0];
  81                 int high = sysctl_local_port_range[1];
  82                 int remaining = (high - low) + 1;
  83                 int rover = net_random() % (high - low) + low;
  84
  85                 do {
  86                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
  87                         spin_lock(&head->lock);
  88                         inet_bind_bucket_for_each(tb, node, &head->chain)
  89                                 if (tb->port == rover)
  90                                         goto next;
  91                         break;
  92                 next:
  93                         spin_unlock(&head->lock);
  94                         if (++rover > high)
  95                                 rover = low;
  96                 } while (--remaining > 0);
  97
  98                 /* Exhausted local port range during search?  It is not
  99                  * possible for us to be holding one of the bind hash
 100                  * locks if this test triggers, because if 'remaining'
 101                  * drops to zero, we broke out of the do/while loop at
 102                  * the top level, not from the 'break;' statement.
 103                  */
 104                 ret = 1;
 105                 if (remaining <= 0)
 106                         goto fail;
 107
 108                 /* OK, here is the one we will use.  HEAD is
 109                  * non-NULL and we hold it's mutex.
 110                  */
 111                 snum = rover;
 112         } else {
 113                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 114                 spin_lock(&head->lock);
 115                 inet_bind_bucket_for_each(tb, node, &head->chain)
 116                         if (tb->port == snum)
 117                                 goto tb_found;
 118         }
 119         tb = NULL;
 120         goto tb_not_found;
 121 tb_found:
 122         if (!hlist_empty(&tb->owners)) {
 123                 if (sk->sk_reuse > 1)
 124                         goto success;
 125                 if (tb->fastreuse > 0 &&
 126                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 127                         goto success;
 128                 } else {
 129                         ret = 1;
 130                         if (bind_conflict(sk, tb))
 131                                 goto fail_unlock;
 132                 }
 133         }
 134 tb_not_found:
 135         ret = 1;
 136         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
 137                 goto fail_unlock;
 138         if (hlist_empty(&tb->owners)) {
 139                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 140                         tb->fastreuse = 1;
 141                 else
 142                         tb->fastreuse = 0;
 143         } else if (tb->fastreuse &&
 144                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 145                 tb->fastreuse = 0;
 146 success:
 147         if (!inet_csk(sk)->icsk_bind_hash)
 148                 inet_bind_hash(sk, tb, snum);
 149         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 150         ret = 0;
 151
 152 fail_unlock:
 153         spin_unlock(&head->lock);
 154 fail:
 155         local_bh_enable();
 156         return ret;
 157 }
 158
 159 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 160
 161 /*
 162  * Wait for an incoming connection, avoid race conditions. This must be called
 163  * with the socket locked.
 164  */
 165 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 166 {
 167         struct inet_connection_sock *icsk = inet_csk(sk);
 168         DEFINE_WAIT(wait);
 169         int err;
 170
 171         /*
 172          * True wake-one mechanism for incoming connections: only
 173          * one process gets woken up, not the 'whole herd'.
 174          * Since we do not 'race & poll' for established sockets
 175          * anymore, the common case will execute the loop only once.
 176          *
 177          * Subtle issue: "add_wait_queue_exclusive()" will be added
 178          * after any current non-exclusive waiters, and we know that
 179          * it will always _stay_ after any new non-exclusive waiters
 180          * because all non-exclusive waiters are added at the
 181          * beginning of the wait-queue. As such, it's ok to "drop"
 182          * our exclusiveness temporarily when we get woken up without
 183          * having to remove and re-insert us on the wait queue.
 184          */
 185         for (;;) {
 186                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 187                                           TASK_INTERRUPTIBLE);
 188                 release_sock(sk);
 189                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 190                         timeo = schedule_timeout(timeo);
 191                 lock_sock(sk);
 192                 err = 0;
 193                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 194                         break;
 195                 err = -EINVAL;
 196                 if (sk->sk_state != TCP_LISTEN)
 197                         break;
 198                 err = sock_intr_errno(timeo);
 199                 if (signal_pending(current))
 200                         break;
 201                 err = -EAGAIN;
 202                 if (!timeo)
 203                         break;
 204         }
 205         finish_wait(sk->sk_sleep, &wait);
 206         return err;
 207 }
 208
 209 /*
 210  * This will accept the next outstanding connection.
 211  */
 212 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 213 {
 214         struct inet_connection_sock *icsk = inet_csk(sk);
 215         struct sock *newsk;
 216         int error;
 217
 218         lock_sock(sk);
 219
 220         /* We need to make sure that this socket is listening,
 221          * and that it has something pending.
 222          */
 223         error = -EINVAL;
 224         if (sk->sk_state != TCP_LISTEN)
 225                 goto out_err;
 226
 227         /* Find already established connection */
 228         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 229                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 230
 231                 /* If this is a non blocking socket don't sleep */
 232                 error = -EAGAIN;
 233                 if (!timeo)
 234                         goto out_err;
 235
 236                 error = inet_csk_wait_for_connect(sk, timeo);
 237                 if (error)
 238                         goto out_err;
 239         }
 240
 241         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 242         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 243 out:
 244         release_sock(sk);
 245         return newsk;
 246 out_err:
 247         newsk = NULL;
 248         *err = error;
 249         goto out;
 250 }
 251
 252 EXPORT_SYMBOL(inet_csk_accept);
 253
 254 /*
 255  * Using different timers for retransmit, delayed acks and probes
 256  * We may wish use just one timer maintaining a list of expire jiffies
 257  * to optimize.
 258  */
 259 void inet_csk_init_xmit_timers(struct sock *sk,
 260                                void (*retransmit_handler)(unsigned long),
 261                                void (*delack_handler)(unsigned long),
 262                                void (*keepalive_handler)(unsigned long))
 263 {
 264         struct inet_connection_sock *icsk = inet_csk(sk);
 265
 266         init_timer(&icsk->icsk_retransmit_timer);
 267         init_timer(&icsk->icsk_delack_timer);
 268         init_timer(&sk->sk_timer);
 269
 270         icsk->icsk_retransmit_timer.function = retransmit_handler;
 271         icsk->icsk_delack_timer.function     = delack_handler;
 272         sk->sk_timer.function                = keepalive_handler;
 273
 274         icsk->icsk_retransmit_timer.data =
 275                 icsk->icsk_delack_timer.data =
 276                         sk->sk_timer.data  = (unsigned long)sk;
 277
 278         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 279 }
 280
 281 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 282
 283 void inet_csk_clear_xmit_timers(struct sock *sk)
 284 {
 285         struct inet_connection_sock *icsk = inet_csk(sk);
 286
 287         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 288
 289         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 290         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 291         sk_stop_timer(sk, &sk->sk_timer);
 292 }
 293
 294 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 295
 296 void inet_csk_delete_keepalive_timer(struct sock *sk)
 297 {
 298         sk_stop_timer(sk, &sk->sk_timer);
 299 }
 300
 301 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 302
 303 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 304 {
 305         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 306 }
 307
 308 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 309
 310 struct dst_entry* inet_csk_route_req(struct sock *sk,
 311                                      const struct request_sock *req)
 312 {
 313         struct rtable *rt;
 314         const struct inet_request_sock *ireq = inet_rsk(req);
 315         struct ip_options *opt = inet_rsk(req)->opt;
 316         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 317                             .nl_u = { .ip4_u =
 318                                       { .daddr = ((opt && opt->srr) ?
 319                                                   opt->faddr :
 320                                                   ireq->rmt_addr),
 321                                         .saddr = ireq->loc_addr,
 322                                         .tos = RT_CONN_FLAGS(sk) } },
 323                             .proto = sk->sk_protocol,
 324                             .uli_u = { .ports =
 325                                        { .sport = inet_sk(sk)->sport,
 326                                          .dport = ireq->rmt_port } } };
 327
 328         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 329                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 330                 return NULL;
 331         }
 332         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 333                 ip_rt_put(rt);
 334                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 335                 return NULL;
 336         }
 337         return &rt->u.dst;
 338 }
 339
 340 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 341
 342 static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
 343                                  const u32 rnd, const u16 synq_hsize)
 344 {
 345         return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
 346 }
 347
 348 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 349 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 350 #else
 351 #define AF_INET_FAMILY(fam) 1
 352 #endif
 353
 354 struct request_sock *inet_csk_search_req(const struct sock *sk,
 355                                          struct request_sock ***prevp,
 356                                          const __u16 rport, const __u32 raddr,
 357                                          const __u32 laddr)
 358 {
 359         const struct inet_connection_sock *icsk = inet_csk(sk);
 360         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 361         struct request_sock *req, **prev;
 362
 363         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 364                                                     lopt->nr_table_entries)];
 365              (req = *prev) != NULL;
 366              prev = &req->dl_next) {
 367                 const struct inet_request_sock *ireq = inet_rsk(req);
 368
 369                 if (ireq->rmt_port == rport &&
 370                     ireq->rmt_addr == raddr &&
 371                     ireq->loc_addr == laddr &&
 372                     AF_INET_FAMILY(req->rsk_ops->family)) {
 373                         BUG_TRAP(!req->sk);
 374                         *prevp = prev;
 375                         break;
 376                 }
 377         }
 378
 379         return req;
 380 }
 381
 382 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 383
 384 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 385                                    unsigned long timeout)
 386 {
 387         struct inet_connection_sock *icsk = inet_csk(sk);
 388         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 389         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 390                                      lopt->hash_rnd, lopt->nr_table_entries);
 391
 392         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 393         inet_csk_reqsk_queue_added(sk, timeout);
 394 }
 395
 396 /* Only thing we need from tcp.h */
 397 extern int sysctl_tcp_synack_retries;
 398
 399 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 400
 401 void inet_csk_reqsk_queue_prune(struct sock *parent,
 402                                 const unsigned long interval,
 403                                 const unsigned long timeout,
 404                                 const unsigned long max_rto)
 405 {
 406         struct inet_connection_sock *icsk = inet_csk(parent);
 407         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 408         struct listen_sock *lopt = queue->listen_opt;
 409         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 410         int thresh = max_retries;
 411         unsigned long now = jiffies;
 412         struct request_sock **reqp, *req;
 413         int i, budget;
 414
 415         if (lopt == NULL || lopt->qlen == 0)
 416                 return;
 417
 418         /* Normally all the openreqs are young and become mature
 419          * (i.e. converted to established socket) for first timeout.
 420          * If synack was not acknowledged for 3 seconds, it means
 421          * one of the following things: synack was lost, ack was lost,
 422          * rtt is high or nobody planned to ack (i.e. synflood).
 423          * When server is a bit loaded, queue is populated with old
 424          * open requests, reducing effective size of queue.
 425          * When server is well loaded, queue size reduces to zero
 426          * after several minutes of work. It is not synflood,
 427          * it is normal operation. The solution is pruning
 428          * too old entries overriding normal timeout, when
 429          * situation becomes dangerous.
 430          *
 431          * Essentially, we reserve half of room for young
 432          * embrions; and abort old ones without pity, if old
 433          * ones are about to clog our table.
 434          */
 435         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 436                 int young = (lopt->qlen_young<<1);
 437
 438                 while (thresh > 2) {
 439                         if (lopt->qlen < young)
 440                                 break;
 441                         thresh--;
 442                         young <<= 1;
 443                 }
 444         }
 445
 446         if (queue->rskq_defer_accept)
 447                 max_retries = queue->rskq_defer_accept;
 448
 449         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 450         i = lopt->clock_hand;
 451
 452         do {
 453                 reqp=&lopt->syn_table[i];
 454                 while ((req = *reqp) != NULL) {
 455                         if (time_after_eq(now, req->expires)) {
 456                                 if ((req->retrans < thresh ||
 457                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 458                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 459                                         unsigned long timeo;
 460
 461                                         if (req->retrans++ == 0)
 462                                                 lopt->qlen_young--;
 463                                         timeo = min((timeout << req->retrans), max_rto);
 464                                         req->expires = now + timeo;
 465                                         reqp = &req->dl_next;
 466                                         continue;
 467                                 }
 468
 469                                 /* Drop this request */
 470                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 471                                 reqsk_queue_removed(queue, req);
 472                                 reqsk_free(req);
 473                                 continue;
 474                         }
 475                         reqp = &req->dl_next;
 476                 }
 477
 478                 i = (i + 1) & (lopt->nr_table_entries - 1);
 479
 480         } while (--budget > 0);
 481
 482         lopt->clock_hand = i;
 483
 484         if (lopt->qlen)
 485                 inet_csk_reset_keepalive_timer(parent, interval);
 486 }
 487
 488 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 489
 490 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 491                             const gfp_t priority)
 492 {
 493         struct sock *newsk = sk_clone(sk, priority);
 494
 495         if (newsk != NULL) {
 496                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 497
 498                 newsk->sk_state = TCP_SYN_RECV;
 499                 newicsk->icsk_bind_hash = NULL;
 500
 501                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 502                 newsk->sk_write_space = sk_stream_write_space;
 503
 504                 newicsk->icsk_retransmits = 0;
 505                 newicsk->icsk_backoff     = 0;
 506                 newicsk->icsk_probes_out  = 0;
 507
 508                 /* Deinitialize accept_queue to trap illegal accesses. */
 509                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 510         }
 511         return newsk;
 512 }
 513
 514 EXPORT_SYMBOL_GPL(inet_csk_clone);
 515
 516 /*
 517  * At this point, there should be no process reference to this
 518  * socket, and thus no user references at all.  Therefore we
 519  * can assume the socket waitqueue is inactive and nobody will
 520  * try to jump onto it.
 521  */
 522 void inet_csk_destroy_sock(struct sock *sk)
 523 {
 524         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 525         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 526
 527         /* It cannot be in hash table! */
 528         BUG_TRAP(sk_unhashed(sk));
 529
 530         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 531         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 532
 533         sk->sk_prot->destroy(sk);
 534
 535         sk_stream_kill_queues(sk);
 536
 537         xfrm_sk_free_policy(sk);
 538
 539         sk_refcnt_debug_release(sk);
 540
 541         atomic_dec(sk->sk_prot->orphan_count);
 542         sock_put(sk);
 543 }
 544
 545 EXPORT_SYMBOL(inet_csk_destroy_sock);
 546
 547 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 548 {
 549         struct inet_sock *inet = inet_sk(sk);
 550         struct inet_connection_sock *icsk = inet_csk(sk);
 551         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 552
 553         if (rc != 0)
 554                 return rc;
 555
 556         sk->sk_max_ack_backlog = 0;
 557         sk->sk_ack_backlog = 0;
 558         inet_csk_delack_init(sk);
 559
 560         /* There is race window here: we announce ourselves listening,
 561          * but this transition is still not validated by get_port().
 562          * It is OK, because this socket enters to hash table only
 563          * after validation is complete.
 564          */
 565         sk->sk_state = TCP_LISTEN;
 566         if (!sk->sk_prot->get_port(sk, inet->num)) {
 567                 inet->sport = htons(inet->num);
 568
 569                 sk_dst_reset(sk);
 570                 sk->sk_prot->hash(sk);
 571
 572                 return 0;
 573         }
 574
 575         sk->sk_state = TCP_CLOSE;
 576         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 577         return -EADDRINUSE;
 578 }
 579
 580 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 581
 582 /*
 583  *      This routine closes sockets which have been at least partially
 584  *      opened, but not yet accepted.
 585  */
 586 void inet_csk_listen_stop(struct sock *sk)
 587 {
 588         struct inet_connection_sock *icsk = inet_csk(sk);
 589         struct request_sock *acc_req;
 590         struct request_sock *req;
 591
 592         inet_csk_delete_keepalive_timer(sk);
 593
 594         /* make all the listen_opt local to us */
 595         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 596
 597         /* Following specs, it would be better either to send FIN
 598          * (and enter FIN-WAIT-1, it is normal close)
 599          * or to send active reset (abort).
 600          * Certainly, it is pretty dangerous while synflood, but it is
 601          * bad justification for our negligence 8)
 602          * To be honest, we are not able to make either
 603          * of the variants now.                 --ANK
 604          */
 605         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 606
 607         while ((req = acc_req) != NULL) {
 608                 struct sock *child = req->sk;
 609
 610                 acc_req = req->dl_next;
 611
 612                 local_bh_disable();
 613                 bh_lock_sock(child);
 614                 BUG_TRAP(!sock_owned_by_user(child));
 615                 sock_hold(child);
 616
 617                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 618
 619                 sock_orphan(child);
 620
 621                 atomic_inc(sk->sk_prot->orphan_count);
 622
 623                 inet_csk_destroy_sock(child);
 624
 625                 bh_unlock_sock(child);
 626                 local_bh_enable();
 627                 sock_put(child);
 628
 629                 sk_acceptq_removed(sk);
 630                 __reqsk_free(req);
 631         }
 632         BUG_TRAP(!sk->sk_ack_backlog);
 633 }
 634
 635 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 636
 637 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 638 {
 639         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 640         const struct inet_sock *inet = inet_sk(sk);
 641
 642         sin->sin_family         = AF_INET;
 643         sin->sin_addr.s_addr    = inet->daddr;
 644         sin->sin_port           = inet->dport;
 645 }
 646
 647 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 648
 649 int inet_csk_ctl_sock_create(struct socket **sock, unsigned short family,
 650                              unsigned short type, unsigned char protocol)
 651 {
 652         int rc = sock_create_kern(family, type, protocol, sock);
 653
 654         if (rc == 0) {
 655                 (*sock)->sk->sk_allocation = GFP_ATOMIC;
 656                 inet_sk((*sock)->sk)->uc_ttl = -1;
 657                 /*
 658                  * Unhash it so that IP input processing does not even see it,
 659                  * we do not wish this socket to see incoming packets.
 660                  */
 661                 (*sock)->sk->sk_prot->unhash((*sock)->sk);
 662         }
 663         return rc;
 664 }
 665
 666 EXPORT_SYMBOL_GPL(inet_csk_ctl_sock_create);
 667
 668 #ifdef CONFIG_COMPAT
 669 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 670                                char __user *optval, int __user *optlen)
 671 {
 672         const struct inet_connection_sock *icsk = inet_csk(sk);
 673
 674         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 675                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 676                                                             optval, optlen);
 677         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 678                                              optval, optlen);
 679 }
 680
 681 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 682
 683 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 684                                char __user *optval, int optlen)
 685 {
 686         const struct inet_connection_sock *icsk = inet_csk(sk);
 687
 688         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 689                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 690                                                             optval, optlen);
 691         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 692                                              optval, optlen);
 693 }
 694
 695 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 696 #endif