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 array holds the first and last local port number.
  34  */
  35 int sysctl_local_port_range[2] = { 32768, 61000 };
  36 DEFINE_SEQLOCK(sysctl_port_range_lock);
  37
  38 void inet_get_local_port_range(int *low, int *high)
  39 {
  40         unsigned seq;
  41         do {
  42                 seq = read_seqbegin(&sysctl_port_range_lock);
  43
  44                 *low = sysctl_local_port_range[0];
  45                 *high = sysctl_local_port_range[1];
  46         } while (read_seqretry(&sysctl_port_range_lock, seq));
  47 }
  48 EXPORT_SYMBOL(inet_get_local_port_range);
  49
  50 int inet_csk_bind_conflict(const struct sock *sk,
  51                            const struct inet_bind_bucket *tb)
  52 {
  53         const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
  54         struct sock *sk2;
  55         struct hlist_node *node;
  56         int reuse = sk->sk_reuse;
  57
  58         sk_for_each_bound(sk2, node, &tb->owners) {
  59                 if (sk != sk2 &&
  60                     !inet_v6_ipv6only(sk2) &&
  61                     (!sk->sk_bound_dev_if ||
  62                      !sk2->sk_bound_dev_if ||
  63                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  64                         if (!reuse || !sk2->sk_reuse ||
  65                             sk2->sk_state == TCP_LISTEN) {
  66                                 const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
  67                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
  68                                     sk2_rcv_saddr == sk_rcv_saddr)
  69                                         break;
  70                         }
  71                 }
  72         }
  73         return node != NULL;
  74 }
  75
  76 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
  77
  78 /* Obtain a reference to a local port for the given sock,
  79  * if snum is zero it means select any available local port.
  80  */
  81 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
  82                       struct sock *sk, unsigned short snum,
  83                       int (*bind_conflict)(const struct sock *sk,
  84                                            const struct inet_bind_bucket *tb))
  85 {
  86         struct inet_bind_hashbucket *head;
  87         struct hlist_node *node;
  88         struct inet_bind_bucket *tb;
  89         int ret;
  90
  91         local_bh_disable();
  92         if (!snum) {
  93                 int remaining, rover, low, high;
  94
  95                 inet_get_local_port_range(&low, &high);
  96                 remaining = high - low;
  97                 rover = net_random() % remaining + low;
  98
  99                 do {
 100                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
 101                         spin_lock(&head->lock);
 102                         inet_bind_bucket_for_each(tb, node, &head->chain)
 103                                 if (tb->port == rover)
 104                                         goto next;
 105                         break;
 106                 next:
 107                         spin_unlock(&head->lock);
 108                         if (++rover > high)
 109                                 rover = low;
 110                 } while (--remaining > 0);
 111
 112                 /* Exhausted local port range during search?  It is not
 113                  * possible for us to be holding one of the bind hash
 114                  * locks if this test triggers, because if 'remaining'
 115                  * drops to zero, we broke out of the do/while loop at
 116                  * the top level, not from the 'break;' statement.
 117                  */
 118                 ret = 1;
 119                 if (remaining <= 0)
 120                         goto fail;
 121
 122                 /* OK, here is the one we will use.  HEAD is
 123                  * non-NULL and we hold it's mutex.
 124                  */
 125                 snum = rover;
 126         } else {
 127                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
 128                 spin_lock(&head->lock);
 129                 inet_bind_bucket_for_each(tb, node, &head->chain)
 130                         if (tb->port == snum)
 131                                 goto tb_found;
 132         }
 133         tb = NULL;
 134         goto tb_not_found;
 135 tb_found:
 136         if (!hlist_empty(&tb->owners)) {
 137                 if (sk->sk_reuse > 1)
 138                         goto success;
 139                 if (tb->fastreuse > 0 &&
 140                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
 141                         goto success;
 142                 } else {
 143                         ret = 1;
 144                         if (bind_conflict(sk, tb))
 145                                 goto fail_unlock;
 146                 }
 147         }
 148 tb_not_found:
 149         ret = 1;
 150         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
 151                 goto fail_unlock;
 152         if (hlist_empty(&tb->owners)) {
 153                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
 154                         tb->fastreuse = 1;
 155                 else
 156                         tb->fastreuse = 0;
 157         } else if (tb->fastreuse &&
 158                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
 159                 tb->fastreuse = 0;
 160 success:
 161         if (!inet_csk(sk)->icsk_bind_hash)
 162                 inet_bind_hash(sk, tb, snum);
 163         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
 164         ret = 0;
 165
 166 fail_unlock:
 167         spin_unlock(&head->lock);
 168 fail:
 169         local_bh_enable();
 170         return ret;
 171 }
 172
 173 EXPORT_SYMBOL_GPL(inet_csk_get_port);
 174
 175 /*
 176  * Wait for an incoming connection, avoid race conditions. This must be called
 177  * with the socket locked.
 178  */
 179 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
 180 {
 181         struct inet_connection_sock *icsk = inet_csk(sk);
 182         DEFINE_WAIT(wait);
 183         int err;
 184
 185         /*
 186          * True wake-one mechanism for incoming connections: only
 187          * one process gets woken up, not the 'whole herd'.
 188          * Since we do not 'race & poll' for established sockets
 189          * anymore, the common case will execute the loop only once.
 190          *
 191          * Subtle issue: "add_wait_queue_exclusive()" will be added
 192          * after any current non-exclusive waiters, and we know that
 193          * it will always _stay_ after any new non-exclusive waiters
 194          * because all non-exclusive waiters are added at the
 195          * beginning of the wait-queue. As such, it's ok to "drop"
 196          * our exclusiveness temporarily when we get woken up without
 197          * having to remove and re-insert us on the wait queue.
 198          */
 199         for (;;) {
 200                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
 201                                           TASK_INTERRUPTIBLE);
 202                 release_sock(sk);
 203                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
 204                         timeo = schedule_timeout(timeo);
 205                 lock_sock(sk);
 206                 err = 0;
 207                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
 208                         break;
 209                 err = -EINVAL;
 210                 if (sk->sk_state != TCP_LISTEN)
 211                         break;
 212                 err = sock_intr_errno(timeo);
 213                 if (signal_pending(current))
 214                         break;
 215                 err = -EAGAIN;
 216                 if (!timeo)
 217                         break;
 218         }
 219         finish_wait(sk->sk_sleep, &wait);
 220         return err;
 221 }
 222
 223 /*
 224  * This will accept the next outstanding connection.
 225  */
 226 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 227 {
 228         struct inet_connection_sock *icsk = inet_csk(sk);
 229         struct sock *newsk;
 230         int error;
 231
 232         lock_sock(sk);
 233
 234         /* We need to make sure that this socket is listening,
 235          * and that it has something pending.
 236          */
 237         error = -EINVAL;
 238         if (sk->sk_state != TCP_LISTEN)
 239                 goto out_err;
 240
 241         /* Find already established connection */
 242         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
 243                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 244
 245                 /* If this is a non blocking socket don't sleep */
 246                 error = -EAGAIN;
 247                 if (!timeo)
 248                         goto out_err;
 249
 250                 error = inet_csk_wait_for_connect(sk, timeo);
 251                 if (error)
 252                         goto out_err;
 253         }
 254
 255         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 256         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
 257 out:
 258         release_sock(sk);
 259         return newsk;
 260 out_err:
 261         newsk = NULL;
 262         *err = error;
 263         goto out;
 264 }
 265
 266 EXPORT_SYMBOL(inet_csk_accept);
 267
 268 /*
 269  * Using different timers for retransmit, delayed acks and probes
 270  * We may wish use just one timer maintaining a list of expire jiffies
 271  * to optimize.
 272  */
 273 void inet_csk_init_xmit_timers(struct sock *sk,
 274                                void (*retransmit_handler)(unsigned long),
 275                                void (*delack_handler)(unsigned long),
 276                                void (*keepalive_handler)(unsigned long))
 277 {
 278         struct inet_connection_sock *icsk = inet_csk(sk);
 279
 280         init_timer(&icsk->icsk_retransmit_timer);
 281         init_timer(&icsk->icsk_delack_timer);
 282         init_timer(&sk->sk_timer);
 283
 284         icsk->icsk_retransmit_timer.function = retransmit_handler;
 285         icsk->icsk_delack_timer.function     = delack_handler;
 286         sk->sk_timer.function                = keepalive_handler;
 287
 288         icsk->icsk_retransmit_timer.data =
 289                 icsk->icsk_delack_timer.data =
 290                         sk->sk_timer.data  = (unsigned long)sk;
 291
 292         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
 293 }
 294
 295 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
 296
 297 void inet_csk_clear_xmit_timers(struct sock *sk)
 298 {
 299         struct inet_connection_sock *icsk = inet_csk(sk);
 300
 301         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 302
 303         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 304         sk_stop_timer(sk, &icsk->icsk_delack_timer);
 305         sk_stop_timer(sk, &sk->sk_timer);
 306 }
 307
 308 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
 309
 310 void inet_csk_delete_keepalive_timer(struct sock *sk)
 311 {
 312         sk_stop_timer(sk, &sk->sk_timer);
 313 }
 314
 315 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
 316
 317 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
 318 {
 319         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 320 }
 321
 322 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 323
 324 struct dst_entry* inet_csk_route_req(struct sock *sk,
 325                                      const struct request_sock *req)
 326 {
 327         struct rtable *rt;
 328         const struct inet_request_sock *ireq = inet_rsk(req);
 329         struct ip_options *opt = inet_rsk(req)->opt;
 330         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 331                             .nl_u = { .ip4_u =
 332                                       { .daddr = ((opt && opt->srr) ?
 333                                                   opt->faddr :
 334                                                   ireq->rmt_addr),
 335                                         .saddr = ireq->loc_addr,
 336                                         .tos = RT_CONN_FLAGS(sk) } },
 337                             .proto = sk->sk_protocol,
 338                             .uli_u = { .ports =
 339                                        { .sport = inet_sk(sk)->sport,
 340                                          .dport = ireq->rmt_port } } };
 341
 342         security_req_classify_flow(req, &fl);
 343         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 344                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 345                 return NULL;
 346         }
 347         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
 348                 ip_rt_put(rt);
 349                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 350                 return NULL;
 351         }
 352         return &rt->u.dst;
 353 }
 354
 355 EXPORT_SYMBOL_GPL(inet_csk_route_req);
 356
 357 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
 358                                  const u32 rnd, const u32 synq_hsize)
 359 {
 360         return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
 361 }
 362
 363 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 364 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
 365 #else
 366 #define AF_INET_FAMILY(fam) 1
 367 #endif
 368
 369 struct request_sock *inet_csk_search_req(const struct sock *sk,
 370                                          struct request_sock ***prevp,
 371                                          const __be16 rport, const __be32 raddr,
 372                                          const __be32 laddr)
 373 {
 374         const struct inet_connection_sock *icsk = inet_csk(sk);
 375         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 376         struct request_sock *req, **prev;
 377
 378         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
 379                                                     lopt->nr_table_entries)];
 380              (req = *prev) != NULL;
 381              prev = &req->dl_next) {
 382                 const struct inet_request_sock *ireq = inet_rsk(req);
 383
 384                 if (ireq->rmt_port == rport &&
 385                     ireq->rmt_addr == raddr &&
 386                     ireq->loc_addr == laddr &&
 387                     AF_INET_FAMILY(req->rsk_ops->family)) {
 388                         BUG_TRAP(!req->sk);
 389                         *prevp = prev;
 390                         break;
 391                 }
 392         }
 393
 394         return req;
 395 }
 396
 397 EXPORT_SYMBOL_GPL(inet_csk_search_req);
 398
 399 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 400                                    unsigned long timeout)
 401 {
 402         struct inet_connection_sock *icsk = inet_csk(sk);
 403         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 404         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
 405                                      lopt->hash_rnd, lopt->nr_table_entries);
 406
 407         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 408         inet_csk_reqsk_queue_added(sk, timeout);
 409 }
 410
 411 /* Only thing we need from tcp.h */
 412 extern int sysctl_tcp_synack_retries;
 413
 414 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 415
 416 void inet_csk_reqsk_queue_prune(struct sock *parent,
 417                                 const unsigned long interval,
 418                                 const unsigned long timeout,
 419                                 const unsigned long max_rto)
 420 {
 421         struct inet_connection_sock *icsk = inet_csk(parent);
 422         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 423         struct listen_sock *lopt = queue->listen_opt;
 424         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
 425         int thresh = max_retries;
 426         unsigned long now = jiffies;
 427         struct request_sock **reqp, *req;
 428         int i, budget;
 429
 430         if (lopt == NULL || lopt->qlen == 0)
 431                 return;
 432
 433         /* Normally all the openreqs are young and become mature
 434          * (i.e. converted to established socket) for first timeout.
 435          * If synack was not acknowledged for 3 seconds, it means
 436          * one of the following things: synack was lost, ack was lost,
 437          * rtt is high or nobody planned to ack (i.e. synflood).
 438          * When server is a bit loaded, queue is populated with old
 439          * open requests, reducing effective size of queue.
 440          * When server is well loaded, queue size reduces to zero
 441          * after several minutes of work. It is not synflood,
 442          * it is normal operation. The solution is pruning
 443          * too old entries overriding normal timeout, when
 444          * situation becomes dangerous.
 445          *
 446          * Essentially, we reserve half of room for young
 447          * embrions; and abort old ones without pity, if old
 448          * ones are about to clog our table.
 449          */
 450         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
 451                 int young = (lopt->qlen_young<<1);
 452
 453                 while (thresh > 2) {
 454                         if (lopt->qlen < young)
 455                                 break;
 456                         thresh--;
 457                         young <<= 1;
 458                 }
 459         }
 460
 461         if (queue->rskq_defer_accept)
 462                 max_retries = queue->rskq_defer_accept;
 463
 464         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
 465         i = lopt->clock_hand;
 466
 467         do {
 468                 reqp=&lopt->syn_table[i];
 469                 while ((req = *reqp) != NULL) {
 470                         if (time_after_eq(now, req->expires)) {
 471                                 if ((req->retrans < thresh ||
 472                                      (inet_rsk(req)->acked && req->retrans < max_retries))
 473                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 474                                         unsigned long timeo;
 475
 476                                         if (req->retrans++ == 0)
 477                                                 lopt->qlen_young--;
 478                                         timeo = min((timeout << req->retrans), max_rto);
 479                                         req->expires = now + timeo;
 480                                         reqp = &req->dl_next;
 481                                         continue;
 482                                 }
 483
 484                                 /* Drop this request */
 485                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
 486                                 reqsk_queue_removed(queue, req);
 487                                 reqsk_free(req);
 488                                 continue;
 489                         }
 490                         reqp = &req->dl_next;
 491                 }
 492
 493                 i = (i + 1) & (lopt->nr_table_entries - 1);
 494
 495         } while (--budget > 0);
 496
 497         lopt->clock_hand = i;
 498
 499         if (lopt->qlen)
 500                 inet_csk_reset_keepalive_timer(parent, interval);
 501 }
 502
 503 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
 504
 505 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 506                             const gfp_t priority)
 507 {
 508         struct sock *newsk = sk_clone(sk, priority);
 509
 510         if (newsk != NULL) {
 511                 struct inet_connection_sock *newicsk = inet_csk(newsk);
 512
 513                 newsk->sk_state = TCP_SYN_RECV;
 514                 newicsk->icsk_bind_hash = NULL;
 515
 516                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
 517                 newsk->sk_write_space = sk_stream_write_space;
 518
 519                 newicsk->icsk_retransmits = 0;
 520                 newicsk->icsk_backoff     = 0;
 521                 newicsk->icsk_probes_out  = 0;
 522
 523                 /* Deinitialize accept_queue to trap illegal accesses. */
 524                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 525
 526                 security_inet_csk_clone(newsk, req);
 527         }
 528         return newsk;
 529 }
 530
 531 EXPORT_SYMBOL_GPL(inet_csk_clone);
 532
 533 /*
 534  * At this point, there should be no process reference to this
 535  * socket, and thus no user references at all.  Therefore we
 536  * can assume the socket waitqueue is inactive and nobody will
 537  * try to jump onto it.
 538  */
 539 void inet_csk_destroy_sock(struct sock *sk)
 540 {
 541         BUG_TRAP(sk->sk_state == TCP_CLOSE);
 542         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
 543
 544         /* It cannot be in hash table! */
 545         BUG_TRAP(sk_unhashed(sk));
 546
 547         /* If it has not 0 inet_sk(sk)->num, it must be bound */
 548         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
 549
 550         sk->sk_prot->destroy(sk);
 551
 552         sk_stream_kill_queues(sk);
 553
 554         xfrm_sk_free_policy(sk);
 555
 556         sk_refcnt_debug_release(sk);
 557
 558         atomic_dec(sk->sk_prot->orphan_count);
 559         sock_put(sk);
 560 }
 561
 562 EXPORT_SYMBOL(inet_csk_destroy_sock);
 563
 564 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 565 {
 566         struct inet_sock *inet = inet_sk(sk);
 567         struct inet_connection_sock *icsk = inet_csk(sk);
 568         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 569
 570         if (rc != 0)
 571                 return rc;
 572
 573         sk->sk_max_ack_backlog = 0;
 574         sk->sk_ack_backlog = 0;
 575         inet_csk_delack_init(sk);
 576
 577         /* There is race window here: we announce ourselves listening,
 578          * but this transition is still not validated by get_port().
 579          * It is OK, because this socket enters to hash table only
 580          * after validation is complete.
 581          */
 582         sk->sk_state = TCP_LISTEN;
 583         if (!sk->sk_prot->get_port(sk, inet->num)) {
 584                 inet->sport = htons(inet->num);
 585
 586                 sk_dst_reset(sk);
 587                 sk->sk_prot->hash(sk);
 588
 589                 return 0;
 590         }
 591
 592         sk->sk_state = TCP_CLOSE;
 593         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
 594         return -EADDRINUSE;
 595 }
 596
 597 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 598
 599 /*
 600  *      This routine closes sockets which have been at least partially
 601  *      opened, but not yet accepted.
 602  */
 603 void inet_csk_listen_stop(struct sock *sk)
 604 {
 605         struct inet_connection_sock *icsk = inet_csk(sk);
 606         struct request_sock *acc_req;
 607         struct request_sock *req;
 608
 609         inet_csk_delete_keepalive_timer(sk);
 610
 611         /* make all the listen_opt local to us */
 612         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
 613
 614         /* Following specs, it would be better either to send FIN
 615          * (and enter FIN-WAIT-1, it is normal close)
 616          * or to send active reset (abort).
 617          * Certainly, it is pretty dangerous while synflood, but it is
 618          * bad justification for our negligence 8)
 619          * To be honest, we are not able to make either
 620          * of the variants now.                 --ANK
 621          */
 622         reqsk_queue_destroy(&icsk->icsk_accept_queue);
 623
 624         while ((req = acc_req) != NULL) {
 625                 struct sock *child = req->sk;
 626
 627                 acc_req = req->dl_next;
 628
 629                 local_bh_disable();
 630                 bh_lock_sock(child);
 631                 BUG_TRAP(!sock_owned_by_user(child));
 632                 sock_hold(child);
 633
 634                 sk->sk_prot->disconnect(child, O_NONBLOCK);
 635
 636                 sock_orphan(child);
 637
 638                 atomic_inc(sk->sk_prot->orphan_count);
 639
 640                 inet_csk_destroy_sock(child);
 641
 642                 bh_unlock_sock(child);
 643                 local_bh_enable();
 644                 sock_put(child);
 645
 646                 sk_acceptq_removed(sk);
 647                 __reqsk_free(req);
 648         }
 649         BUG_TRAP(!sk->sk_ack_backlog);
 650 }
 651
 652 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
 653
 654 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
 655 {
 656         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 657         const struct inet_sock *inet = inet_sk(sk);
 658
 659         sin->sin_family         = AF_INET;
 660         sin->sin_addr.s_addr    = inet->daddr;
 661         sin->sin_port           = inet->dport;
 662 }
 663
 664 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
 665
 666 int inet_csk_ctl_sock_create(struct socket **sock, unsigned short family,
 667                              unsigned short type, unsigned char protocol)
 668 {
 669         int rc = sock_create_kern(family, type, protocol, sock);
 670
 671         if (rc == 0) {
 672                 (*sock)->sk->sk_allocation = GFP_ATOMIC;
 673                 inet_sk((*sock)->sk)->uc_ttl = -1;
 674                 /*
 675                  * Unhash it so that IP input processing does not even see it,
 676                  * we do not wish this socket to see incoming packets.
 677                  */
 678                 (*sock)->sk->sk_prot->unhash((*sock)->sk);
 679         }
 680         return rc;
 681 }
 682
 683 EXPORT_SYMBOL_GPL(inet_csk_ctl_sock_create);
 684
 685 #ifdef CONFIG_COMPAT
 686 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 687                                char __user *optval, int __user *optlen)
 688 {
 689         const struct inet_connection_sock *icsk = inet_csk(sk);
 690
 691         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
 692                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 693                                                             optval, optlen);
 694         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
 695                                              optval, optlen);
 696 }
 697
 698 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
 699
 700 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 701                                char __user *optval, int optlen)
 702 {
 703         const struct inet_connection_sock *icsk = inet_csk(sk);
 704
 705         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
 706                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 707                                                             optval, optlen);
 708         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
 709                                              optval, optlen);
 710 }
 711
 712 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
 713 #endif