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         const u32 sk_rcv_saddr = inet_rcv_saddr(sk);
  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                                 const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
  56                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
  57                                     sk2_rcv_saddr == sk_rcv_saddr)
  58                                         break;
  59                         }
  60                 }
  61         }
  62         return node != NULL;
  63 }
  64
  65 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  66
  67 /* Obtain a reference to a local port for the given sock,
  68  * if snum is zero it means select any available local port.
  69  */
  70 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
  71                       struct sock *sk, unsigned short snum,
  72                       int (*bind_conflict)(const struct sock *sk,
  73                                            const struct inet_bind_bucket *tb))
  74 {
  75         struct inet_bind_hashbucket *head;
  76         struct hlist_node *node;
  77         struct inet_bind_bucket *tb;
  78         int ret;
  79
  80         local_bh_disable();
  81         if (!snum) {
  82                 int low = sysctl_local_port_range[0];
  83                 int high = sysctl_local_port_range[1];
  84                 int remaining = (high - low) + 1;
  85                 int rover = net_random() % (high - low) + low;
  86
  87                 do {
  88                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
  89                         spin_lock(&head->lock);
  90                         inet_bind_bucket_for_each(tb, node, &head->chain)
  91                                 if (tb->port == rover)
  92                                         goto next;
  93                         break;
  94                 next:
  95                         spin_unlock(&head->lock);
  96                         if (++rover > high)
  97                                 rover = low;
  98                 } while (--remaining > 0);
  99
 100                 /* Exhausted local port range during search?  It is not
 101                  * possible for us to be holding one of the bind hash
 102                  * locks if this test triggers, because if 'remaining'
 103                  * drops to zero, we broke out of the do/while loop at
 104                  * the top level, not from the 'break;' statement.
 105                  */
 106                 ret = 1;
 107                 if (remaining <= 0)
 108                         goto fail;
 109
 110                 /* OK, here is the one we will use.  HEAD is
 111                  * non-NULL and we hold it's mutex.
 112                  */
 113                 snum = rover;
 114         } else {
 115                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 116                 spin_lock(&head->lock);
 117                 inet_bind_bucket_for_each(tb, node, &head->chain)
 118                         if (tb->port == snum)
 119                                 goto tb_found;
 120         }
 121         tb = NULL;
 122         goto tb_not_found;
 123 tb_found:
 124         if (!hlist_empty(&tb->owners)) {
 125                 if (sk->sk_reuse > 1)
 126                         goto success;
 127                 if (tb->fastreuse > 0 &&
 128                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 129                         goto success;
 130                 } else {
 131                         ret = 1;
 132                         if (bind_conflict(sk, tb))
 133                                 goto fail_unlock;
 134                 }
 135         }
 136 tb_not_found:
 137         ret = 1;
 138         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
 139                 goto fail_unlock;
 140         if (hlist_empty(&tb->owners)) {
 141                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 142                         tb->fastreuse = 1;
 143                 else
 144                         tb->fastreuse = 0;
 145         } else if (tb->fastreuse &&
 146                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 147                 tb->fastreuse = 0;
 148 success:
 149         if (!inet_csk(sk)->icsk_bind_hash)
 150                 inet_bind_hash(sk, tb, snum);
 151         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 152         ret = 0;
 153
 154 fail_unlock:
 155         spin_unlock(&head->lock);
 156 fail:
 157         local_bh_enable();
 158         return ret;
 159 }
 160
 161 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 162
 163 /*
 164  * Wait for an incoming connection, avoid race conditions. This must be called
 165  * with the socket locked.
 166  */
 167 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 168 {
 169         struct inet_connection_sock *icsk = inet_csk(sk);
 170         DEFINE_WAIT(wait);
 171         int err;
 172
 173         /*
 174          * True wake-one mechanism for incoming connections: only
 175          * one process gets woken up, not the 'whole herd'.
 176          * Since we do not 'race & poll' for established sockets
 177          * anymore, the common case will execute the loop only once.
 178          *
 179          * Subtle issue: "add_wait_queue_exclusive()" will be added
 180          * after any current non-exclusive waiters, and we know that
 181          * it will always _stay_ after any new non-exclusive waiters
 182          * because all non-exclusive waiters are added at the
 183          * beginning of the wait-queue. As such, it's ok to "drop"
 184          * our exclusiveness temporarily when we get woken up without
 185          * having to remove and re-insert us on the wait queue.
 186          */
 187         for (;;) {
 188                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 189                                           TASK_INTERRUPTIBLE);
 190                 release_sock(sk);
 191                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 192                         timeo = schedule_timeout(timeo);
 193                 lock_sock(sk);
 194                 err = 0;
 195                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 196                         break;
 197                 err = -EINVAL;
 198                 if (sk->sk_state != TCP_LISTEN)
 199                         break;
 200                 err = sock_intr_errno(timeo);
 201                 if (signal_pending(current))
 202                         break;
 203                 err = -EAGAIN;
 204                 if (!timeo)
 205                         break;
 206         }
 207         finish_wait(sk->sk_sleep, &wait);
 208         return err;
 209 }
 210
 211 /*
 212  * This will accept the next outstanding connection.
 213  */
 214 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 215 {
 216         struct inet_connection_sock *icsk = inet_csk(sk);
 217         struct sock *newsk;
 218         int error;
 219
 220         lock_sock(sk);
 221
 222         /* We need to make sure that this socket is listening,
 223          * and that it has something pending.
 224          */
 225         error = -EINVAL;
 226         if (sk->sk_state != TCP_LISTEN)
 227                 goto out_err;
 228
 229         /* Find already established connection */
 230         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 231                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 232
 233                 /* If this is a non blocking socket don't sleep */
 234                 error = -EAGAIN;
 235                 if (!timeo)
 236                         goto out_err;
 237
 238                 error = inet_csk_wait_for_connect(sk, timeo);
 239                 if (error)
 240                         goto out_err;
 241         }
 242
 243         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 244         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 245 out:
 246         release_sock(sk);
 247         return newsk;
 248 out_err:
 249         newsk = NULL;
 250         *err = error;
 251         goto out;
 252 }
 253
 254 EXPORT_SYMBOL(inet_csk_accept);
 255
 256 /*
 257  * Using different timers for retransmit, delayed acks and probes
 258  * We may wish use just one timer maintaining a list of expire jiffies
 259  * to optimize.
 260  */
 261 void inet_csk_init_xmit_timers(struct sock *sk,
 262                                void (*retransmit_handler)(unsigned long),
 263                                void (*delack_handler)(unsigned long),
 264                                void (*keepalive_handler)(unsigned long))
 265 {
 266         struct inet_connection_sock *icsk = inet_csk(sk);
 267
 268         init_timer(&icsk->icsk_retransmit_timer);
 269         init_timer(&icsk->icsk_delack_timer);
 270         init_timer(&sk->sk_timer);
 271
 272         icsk->icsk_retransmit_timer.function = retransmit_handler;
 273         icsk->icsk_delack_timer.function     = delack_handler;
 274         sk->sk_timer.function                = keepalive_handler;
 275
 276         icsk->icsk_retransmit_timer.data =
 277                 icsk->icsk_delack_timer.data =
 278                         sk->sk_timer.data  = (unsigned long)sk;
 279
 280         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 281 }
 282
 283 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 284
 285 void inet_csk_clear_xmit_timers(struct sock *sk)
 286 {
 287         struct inet_connection_sock *icsk = inet_csk(sk);
 288
 289         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 290
 291         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 292         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 293         sk_stop_timer(sk, &sk->sk_timer);
 294 }
 295
 296 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 297
 298 void inet_csk_delete_keepalive_timer(struct sock *sk)
 299 {
 300         sk_stop_timer(sk, &sk->sk_timer);
 301 }
 302
 303 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 304
 305 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 306 {
 307         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 308 }
 309
 310 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 311
 312 struct dst_entry* inet_csk_route_req(struct sock *sk,
 313                                      const struct request_sock *req)
 314 {
 315         struct rtable *rt;
 316         const struct inet_request_sock *ireq = inet_rsk(req);
 317         struct ip_options *opt = inet_rsk(req)->opt;
 318         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 319                             .nl_u = { .ip4_u =
 320                                       { .daddr = ((opt && opt->srr) ?
 321                                                   opt->faddr :
 322                                                   ireq->rmt_addr),
 323                                         .saddr = ireq->loc_addr,
 324                                         .tos = RT_CONN_FLAGS(sk) } },
 325                             .proto = sk->sk_protocol,
 326                             .uli_u = { .ports =
 327                                        { .sport = inet_sk(sk)->sport,
 328                                          .dport = ireq->rmt_port } } };
 329
 330         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 331                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 332                 return NULL;
 333         }
 334         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 335                 ip_rt_put(rt);
 336                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 337                 return NULL;
 338         }
 339         return &rt->u.dst;
 340 }
 341
 342 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 343
 344 static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
 345                                  const u32 rnd, const u16 synq_hsize)
 346 {
 347         return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
 348 }
 349
 350 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 351 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 352 #else
 353 #define AF_INET_FAMILY(fam) 1
 354 #endif
 355
 356 struct request_sock *inet_csk_search_req(const struct sock *sk,
 357                                          struct request_sock ***prevp,
 358                                          const __u16 rport, const __u32 raddr,
 359                                          const __u32 laddr)
 360 {
 361         const struct inet_connection_sock *icsk = inet_csk(sk);
 362         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 363         struct request_sock *req, **prev;
 364
 365         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 366                                                     lopt->nr_table_entries)];
 367              (req = *prev) != NULL;
 368              prev = &req->dl_next) {
 369                 const struct inet_request_sock *ireq = inet_rsk(req);
 370
 371                 if (ireq->rmt_port == rport &&
 372                     ireq->rmt_addr == raddr &&
 373                     ireq->loc_addr == laddr &&
 374                     AF_INET_FAMILY(req->rsk_ops->family)) {
 375                         BUG_TRAP(!req->sk);
 376                         *prevp = prev;
 377                         break;
 378                 }
 379         }
 380
 381         return req;
 382 }
 383
 384 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 385
 386 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 387                                    unsigned long timeout)
 388 {
 389         struct inet_connection_sock *icsk = inet_csk(sk);
 390         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 391         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 392                                      lopt->hash_rnd, lopt->nr_table_entries);
 393
 394         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 395         inet_csk_reqsk_queue_added(sk, timeout);
 396 }
 397
 398 /* Only thing we need from tcp.h */
 399 extern int sysctl_tcp_synack_retries;
 400
 401 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 402
 403 void inet_csk_reqsk_queue_prune(struct sock *parent,
 404                                 const unsigned long interval,
 405                                 const unsigned long timeout,
 406                                 const unsigned long max_rto)
 407 {
 408         struct inet_connection_sock *icsk = inet_csk(parent);
 409         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 410         struct listen_sock *lopt = queue->listen_opt;
 411         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 412         int thresh = max_retries;
 413         unsigned long now = jiffies;
 414         struct request_sock **reqp, *req;
 415         int i, budget;
 416
 417         if (lopt == NULL || lopt->qlen == 0)
 418                 return;
 419
 420         /* Normally all the openreqs are young and become mature
 421          * (i.e. converted to established socket) for first timeout.
 422          * If synack was not acknowledged for 3 seconds, it means
 423          * one of the following things: synack was lost, ack was lost,
 424          * rtt is high or nobody planned to ack (i.e. synflood).
 425          * When server is a bit loaded, queue is populated with old
 426          * open requests, reducing effective size of queue.
 427          * When server is well loaded, queue size reduces to zero
 428          * after several minutes of work. It is not synflood,
 429          * it is normal operation. The solution is pruning
 430          * too old entries overriding normal timeout, when
 431          * situation becomes dangerous.
 432          *
 433          * Essentially, we reserve half of room for young
 434          * embrions; and abort old ones without pity, if old
 435          * ones are about to clog our table.
 436          */
 437         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 438                 int young = (lopt->qlen_young<<1);
 439
 440                 while (thresh > 2) {
 441                         if (lopt->qlen < young)
 442                                 break;
 443                         thresh--;
 444                         young <<= 1;
 445                 }
 446         }
 447
 448         if (queue->rskq_defer_accept)
 449                 max_retries = queue->rskq_defer_accept;
 450
 451         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 452         i = lopt->clock_hand;
 453
 454         do {
 455                 reqp=&lopt->syn_table[i];
 456                 while ((req = *reqp) != NULL) {
 457                         if (time_after_eq(now, req->expires)) {
 458                                 if ((req->retrans < thresh ||
 459                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 460                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 461                                         unsigned long timeo;
 462
 463                                         if (req->retrans++ == 0)
 464                                                 lopt->qlen_young--;
 465                                         timeo = min((timeout << req->retrans), max_rto);
 466                                         req->expires = now + timeo;
 467                                         reqp = &req->dl_next;
 468                                         continue;
 469                                 }
 470
 471                                 /* Drop this request */
 472                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 473                                 reqsk_queue_removed(queue, req);
 474                                 reqsk_free(req);
 475                                 continue;
 476                         }
 477                         reqp = &req->dl_next;
 478                 }
 479
 480                 i = (i + 1) & (lopt->nr_table_entries - 1);
 481
 482         } while (--budget > 0);
 483
 484         lopt->clock_hand = i;
 485
 486         if (lopt->qlen)
 487                 inet_csk_reset_keepalive_timer(parent, interval);
 488 }
 489
 490 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 491
 492 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 493                             const gfp_t priority)
 494 {
 495         struct sock *newsk = sk_clone(sk, priority);
 496
 497         if (newsk != NULL) {
 498                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 499
 500                 newsk->sk_state = TCP_SYN_RECV;
 501                 newicsk->icsk_bind_hash = NULL;
 502
 503                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 504                 newsk->sk_write_space = sk_stream_write_space;
 505
 506                 newicsk->icsk_retransmits = 0;
 507                 newicsk->icsk_backoff     = 0;
 508                 newicsk->icsk_probes_out  = 0;
 509
 510                 /* Deinitialize accept_queue to trap illegal accesses. */
 511                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 512         }
 513         return newsk;
 514 }
 515
 516 EXPORT_SYMBOL_GPL(inet_csk_clone);
 517
 518 /*
 519  * At this point, there should be no process reference to this
 520  * socket, and thus no user references at all.  Therefore we
 521  * can assume the socket waitqueue is inactive and nobody will
 522  * try to jump onto it.
 523  */
 524 void inet_csk_destroy_sock(struct sock *sk)
 525 {
 526         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 527         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 528
 529         /* It cannot be in hash table! */
 530         BUG_TRAP(sk_unhashed(sk));
 531
 532         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 533         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 534
 535         sk->sk_prot->destroy(sk);
 536
 537         sk_stream_kill_queues(sk);
 538
 539         xfrm_sk_free_policy(sk);
 540
 541         sk_refcnt_debug_release(sk);
 542
 543         atomic_dec(sk->sk_prot->orphan_count);
 544         sock_put(sk);
 545 }
 546
 547 EXPORT_SYMBOL(inet_csk_destroy_sock);
 548
 549 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 550 {
 551         struct inet_sock *inet = inet_sk(sk);
 552         struct inet_connection_sock *icsk = inet_csk(sk);
 553         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 554
 555         if (rc != 0)
 556                 return rc;
 557
 558         sk->sk_max_ack_backlog = 0;
 559         sk->sk_ack_backlog = 0;
 560         inet_csk_delack_init(sk);
 561
 562         /* There is race window here: we announce ourselves listening,
 563          * but this transition is still not validated by get_port().
 564          * It is OK, because this socket enters to hash table only
 565          * after validation is complete.
 566          */
 567         sk->sk_state = TCP_LISTEN;
 568         if (!sk->sk_prot->get_port(sk, inet->num)) {
 569                 inet->sport = htons(inet->num);
 570
 571                 sk_dst_reset(sk);
 572                 sk->sk_prot->hash(sk);
 573
 574                 return 0;
 575         }
 576
 577         sk->sk_state = TCP_CLOSE;
 578         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 579         return -EADDRINUSE;
 580 }
 581
 582 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 583
 584 /*
 585  *      This routine closes sockets which have been at least partially
 586  *      opened, but not yet accepted.
 587  */
 588 void inet_csk_listen_stop(struct sock *sk)
 589 {
 590         struct inet_connection_sock *icsk = inet_csk(sk);
 591         struct request_sock *acc_req;
 592         struct request_sock *req;
 593
 594         inet_csk_delete_keepalive_timer(sk);
 595
 596         /* make all the listen_opt local to us */
 597         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 598
 599         /* Following specs, it would be better either to send FIN
 600          * (and enter FIN-WAIT-1, it is normal close)
 601          * or to send active reset (abort).
 602          * Certainly, it is pretty dangerous while synflood, but it is
 603          * bad justification for our negligence 8)
 604          * To be honest, we are not able to make either
 605          * of the variants now.                 --ANK
 606          */
 607         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 608
 609         while ((req = acc_req) != NULL) {
 610                 struct sock *child = req->sk;
 611
 612                 acc_req = req->dl_next;
 613
 614                 local_bh_disable();
 615                 bh_lock_sock(child);
 616                 BUG_TRAP(!sock_owned_by_user(child));
 617                 sock_hold(child);
 618
 619                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 620
 621                 sock_orphan(child);
 622
 623                 atomic_inc(sk->sk_prot->orphan_count);
 624
 625                 inet_csk_destroy_sock(child);
 626
 627                 bh_unlock_sock(child);
 628                 local_bh_enable();
 629                 sock_put(child);
 630
 631                 sk_acceptq_removed(sk);
 632                 __reqsk_free(req);
 633         }
 634         BUG_TRAP(!sk->sk_ack_backlog);
 635 }
 636
 637 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 638
 639 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 640 {
 641         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 642         const struct inet_sock *inet = inet_sk(sk);
 643
 644         sin->sin_family         = AF_INET;
 645         sin->sin_addr.s_addr    = inet->daddr;
 646         sin->sin_port           = inet->dport;
 647 }
 648
 649 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 650
 651 int inet_csk_ctl_sock_create(struct socket **sock, unsigned short family,
 652                              unsigned short type, unsigned char protocol)
 653 {
 654         int rc = sock_create_kern(family, type, protocol, sock);
 655
 656         if (rc == 0) {
 657                 (*sock)->sk->sk_allocation = GFP_ATOMIC;
 658                 inet_sk((*sock)->sk)->uc_ttl = -1;
 659                 /*
 660                  * Unhash it so that IP input processing does not even see it,
 661                  * we do not wish this socket to see incoming packets.
 662                  */
 663                 (*sock)->sk->sk_prot->unhash((*sock)->sk);
 664         }
 665         return rc;
 666 }
 667
 668 EXPORT_SYMBOL_GPL(inet_csk_ctl_sock_create);
 669
 670 #ifdef CONFIG_COMPAT
 671 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 672                                char __user *optval, int __user *optlen)
 673 {
 674         const struct inet_connection_sock *icsk = inet_csk(sk);
 675
 676         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 677                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 678                                                             optval, optlen);
 679         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 680                                              optval, optlen);
 681 }
 682
 683 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 684
 685 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 686                                char __user *optval, int optlen)
 687 {
 688         const struct inet_connection_sock *icsk = inet_csk(sk);
 689
 690         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 691                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 692                                                             optval, optlen);
 693         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 694                                              optval, optlen);
 695 }
 696
 697 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 698 #endif