inet_connection_sock.c revision 7433819a1eefd4e74711fffd6d54e30a644ef240
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 28const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n"; 29EXPORT_SYMBOL(inet_csk_timer_bug_msg); 30#endif 31 32/* 33 * This struct holds the first and last local port number. 34 */ 35struct local_ports sysctl_local_ports __read_mostly = { 36 .lock = __SEQLOCK_UNLOCKED(sysctl_local_ports.lock), 37 .range = { 32768, 61000 }, 38}; 39 40unsigned long *sysctl_local_reserved_ports; 41EXPORT_SYMBOL(sysctl_local_reserved_ports); 42 43void inet_get_local_port_range(int *low, int *high) 44{ 45 unsigned int seq; 46 47 do { 48 seq = read_seqbegin(&sysctl_local_ports.lock); 49 50 *low = sysctl_local_ports.range[0]; 51 *high = sysctl_local_ports.range[1]; 52 } while (read_seqretry(&sysctl_local_ports.lock, seq)); 53} 54EXPORT_SYMBOL(inet_get_local_port_range); 55 56int inet_csk_bind_conflict(const struct sock *sk, 57 const struct inet_bind_bucket *tb, bool relax) 58{ 59 struct sock *sk2; 60 struct hlist_node *node; 61 int reuse = sk->sk_reuse; 62 63 /* 64 * Unlike other sk lookup places we do not check 65 * for sk_net here, since _all_ the socks listed 66 * in tb->owners list belong to the same net - the 67 * one this bucket belongs to. 68 */ 69 70 sk_for_each_bound(sk2, node, &tb->owners) { 71 if (sk != sk2 && 72 !inet_v6_ipv6only(sk2) && 73 (!sk->sk_bound_dev_if || 74 !sk2->sk_bound_dev_if || 75 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { 76 if (!reuse || !sk2->sk_reuse || 77 sk2->sk_state == TCP_LISTEN) { 78 const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); 79 if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || 80 sk2_rcv_saddr == sk_rcv_saddr(sk)) 81 break; 82 } 83 if (!relax && reuse && sk2->sk_reuse && 84 sk2->sk_state != TCP_LISTEN) { 85 const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); 86 87 if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || 88 sk2_rcv_saddr == sk_rcv_saddr(sk)) 89 break; 90 } 91 } 92 } 93 return node != NULL; 94} 95EXPORT_SYMBOL_GPL(inet_csk_bind_conflict); 96 97/* Obtain a reference to a local port for the given sock, 98 * if snum is zero it means select any available local port. 99 */ 100int inet_csk_get_port(struct sock *sk, unsigned short snum) 101{ 102 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 103 struct inet_bind_hashbucket *head; 104 struct hlist_node *node; 105 struct inet_bind_bucket *tb; 106 int ret, attempts = 5; 107 struct net *net = sock_net(sk); 108 int smallest_size = -1, smallest_rover; 109 110 local_bh_disable(); 111 if (!snum) { 112 int remaining, rover, low, high; 113 114again: 115 inet_get_local_port_range(&low, &high); 116 remaining = (high - low) + 1; 117 smallest_rover = rover = net_random() % remaining + low; 118 119 smallest_size = -1; 120 do { 121 if (inet_is_reserved_local_port(rover)) 122 goto next_nolock; 123 head = &hashinfo->bhash[inet_bhashfn(net, rover, 124 hashinfo->bhash_size)]; 125 spin_lock(&head->lock); 126 inet_bind_bucket_for_each(tb, node, &head->chain) 127 if (net_eq(ib_net(tb), net) && tb->port == rover) { 128 if (tb->fastreuse > 0 && 129 sk->sk_reuse && 130 sk->sk_state != TCP_LISTEN && 131 (tb->num_owners < smallest_size || smallest_size == -1)) { 132 smallest_size = tb->num_owners; 133 smallest_rover = rover; 134 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 && 135 !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { 136 snum = smallest_rover; 137 goto tb_found; 138 } 139 } 140 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { 141 snum = rover; 142 goto tb_found; 143 } 144 goto next; 145 } 146 break; 147 next: 148 spin_unlock(&head->lock); 149 next_nolock: 150 if (++rover > high) 151 rover = low; 152 } while (--remaining > 0); 153 154 /* Exhausted local port range during search? It is not 155 * possible for us to be holding one of the bind hash 156 * locks if this test triggers, because if 'remaining' 157 * drops to zero, we broke out of the do/while loop at 158 * the top level, not from the 'break;' statement. 159 */ 160 ret = 1; 161 if (remaining <= 0) { 162 if (smallest_size != -1) { 163 snum = smallest_rover; 164 goto have_snum; 165 } 166 goto fail; 167 } 168 /* OK, here is the one we will use. HEAD is 169 * non-NULL and we hold it's mutex. 170 */ 171 snum = rover; 172 } else { 173have_snum: 174 head = &hashinfo->bhash[inet_bhashfn(net, snum, 175 hashinfo->bhash_size)]; 176 spin_lock(&head->lock); 177 inet_bind_bucket_for_each(tb, node, &head->chain) 178 if (net_eq(ib_net(tb), net) && tb->port == snum) 179 goto tb_found; 180 } 181 tb = NULL; 182 goto tb_not_found; 183tb_found: 184 if (!hlist_empty(&tb->owners)) { 185 if (sk->sk_reuse == SK_FORCE_REUSE) 186 goto success; 187 188 if (tb->fastreuse > 0 && 189 sk->sk_reuse && sk->sk_state != TCP_LISTEN && 190 smallest_size == -1) { 191 goto success; 192 } else { 193 ret = 1; 194 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) { 195 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && 196 smallest_size != -1 && --attempts >= 0) { 197 spin_unlock(&head->lock); 198 goto again; 199 } 200 201 goto fail_unlock; 202 } 203 } 204 } 205tb_not_found: 206 ret = 1; 207 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, 208 net, head, snum)) == NULL) 209 goto fail_unlock; 210 if (hlist_empty(&tb->owners)) { 211 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN) 212 tb->fastreuse = 1; 213 else 214 tb->fastreuse = 0; 215 } else if (tb->fastreuse && 216 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) 217 tb->fastreuse = 0; 218success: 219 if (!inet_csk(sk)->icsk_bind_hash) 220 inet_bind_hash(sk, tb, snum); 221 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); 222 ret = 0; 223 224fail_unlock: 225 spin_unlock(&head->lock); 226fail: 227 local_bh_enable(); 228 return ret; 229} 230EXPORT_SYMBOL_GPL(inet_csk_get_port); 231 232/* 233 * Wait for an incoming connection, avoid race conditions. This must be called 234 * with the socket locked. 235 */ 236static int inet_csk_wait_for_connect(struct sock *sk, long timeo) 237{ 238 struct inet_connection_sock *icsk = inet_csk(sk); 239 DEFINE_WAIT(wait); 240 int err; 241 242 /* 243 * True wake-one mechanism for incoming connections: only 244 * one process gets woken up, not the 'whole herd'. 245 * Since we do not 'race & poll' for established sockets 246 * anymore, the common case will execute the loop only once. 247 * 248 * Subtle issue: "add_wait_queue_exclusive()" will be added 249 * after any current non-exclusive waiters, and we know that 250 * it will always _stay_ after any new non-exclusive waiters 251 * because all non-exclusive waiters are added at the 252 * beginning of the wait-queue. As such, it's ok to "drop" 253 * our exclusiveness temporarily when we get woken up without 254 * having to remove and re-insert us on the wait queue. 255 */ 256 for (;;) { 257 prepare_to_wait_exclusive(sk_sleep(sk), &wait, 258 TASK_INTERRUPTIBLE); 259 release_sock(sk); 260 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) 261 timeo = schedule_timeout(timeo); 262 lock_sock(sk); 263 err = 0; 264 if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) 265 break; 266 err = -EINVAL; 267 if (sk->sk_state != TCP_LISTEN) 268 break; 269 err = sock_intr_errno(timeo); 270 if (signal_pending(current)) 271 break; 272 err = -EAGAIN; 273 if (!timeo) 274 break; 275 } 276 finish_wait(sk_sleep(sk), &wait); 277 return err; 278} 279 280/* 281 * This will accept the next outstanding connection. 282 */ 283struct sock *inet_csk_accept(struct sock *sk, int flags, int *err) 284{ 285 struct inet_connection_sock *icsk = inet_csk(sk); 286 struct sock *newsk; 287 int error; 288 289 lock_sock(sk); 290 291 /* We need to make sure that this socket is listening, 292 * and that it has something pending. 293 */ 294 error = -EINVAL; 295 if (sk->sk_state != TCP_LISTEN) 296 goto out_err; 297 298 /* Find already established connection */ 299 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) { 300 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); 301 302 /* If this is a non blocking socket don't sleep */ 303 error = -EAGAIN; 304 if (!timeo) 305 goto out_err; 306 307 error = inet_csk_wait_for_connect(sk, timeo); 308 if (error) 309 goto out_err; 310 } 311 312 newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk); 313 WARN_ON(newsk->sk_state == TCP_SYN_RECV); 314out: 315 release_sock(sk); 316 return newsk; 317out_err: 318 newsk = NULL; 319 *err = error; 320 goto out; 321} 322EXPORT_SYMBOL(inet_csk_accept); 323 324/* 325 * Using different timers for retransmit, delayed acks and probes 326 * We may wish use just one timer maintaining a list of expire jiffies 327 * to optimize. 328 */ 329void inet_csk_init_xmit_timers(struct sock *sk, 330 void (*retransmit_handler)(unsigned long), 331 void (*delack_handler)(unsigned long), 332 void (*keepalive_handler)(unsigned long)) 333{ 334 struct inet_connection_sock *icsk = inet_csk(sk); 335 336 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler, 337 (unsigned long)sk); 338 setup_timer(&icsk->icsk_delack_timer, delack_handler, 339 (unsigned long)sk); 340 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk); 341 icsk->icsk_pending = icsk->icsk_ack.pending = 0; 342} 343EXPORT_SYMBOL(inet_csk_init_xmit_timers); 344 345void inet_csk_clear_xmit_timers(struct sock *sk) 346{ 347 struct inet_connection_sock *icsk = inet_csk(sk); 348 349 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0; 350 351 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 352 sk_stop_timer(sk, &icsk->icsk_delack_timer); 353 sk_stop_timer(sk, &sk->sk_timer); 354} 355EXPORT_SYMBOL(inet_csk_clear_xmit_timers); 356 357void inet_csk_delete_keepalive_timer(struct sock *sk) 358{ 359 sk_stop_timer(sk, &sk->sk_timer); 360} 361EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); 362 363void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) 364{ 365 sk_reset_timer(sk, &sk->sk_timer, jiffies + len); 366} 367EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); 368 369struct dst_entry *inet_csk_route_req(struct sock *sk, 370 struct flowi4 *fl4, 371 const struct request_sock *req) 372{ 373 struct rtable *rt; 374 const struct inet_request_sock *ireq = inet_rsk(req); 375 struct ip_options_rcu *opt = inet_rsk(req)->opt; 376 struct net *net = sock_net(sk); 377 378 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 379 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 380 sk->sk_protocol, 381 inet_sk_flowi_flags(sk) & ~FLOWI_FLAG_PRECOW_METRICS, 382 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, 383 ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); 384 security_req_classify_flow(req, flowi4_to_flowi(fl4)); 385 rt = ip_route_output_flow(net, fl4, sk); 386 if (IS_ERR(rt)) 387 goto no_route; 388 if (opt && opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway) 389 goto route_err; 390 return &rt->dst; 391 392route_err: 393 ip_rt_put(rt); 394no_route: 395 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 396 return NULL; 397} 398EXPORT_SYMBOL_GPL(inet_csk_route_req); 399 400struct dst_entry *inet_csk_route_child_sock(struct sock *sk, 401 struct sock *newsk, 402 const struct request_sock *req) 403{ 404 const struct inet_request_sock *ireq = inet_rsk(req); 405 struct inet_sock *newinet = inet_sk(newsk); 406 struct ip_options_rcu *opt = ireq->opt; 407 struct net *net = sock_net(sk); 408 struct flowi4 *fl4; 409 struct rtable *rt; 410 411 fl4 = &newinet->cork.fl.u.ip4; 412 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 413 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 414 sk->sk_protocol, inet_sk_flowi_flags(sk), 415 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, 416 ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); 417 security_req_classify_flow(req, flowi4_to_flowi(fl4)); 418 rt = ip_route_output_flow(net, fl4, sk); 419 if (IS_ERR(rt)) 420 goto no_route; 421 if (opt && opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway) 422 goto route_err; 423 return &rt->dst; 424 425route_err: 426 ip_rt_put(rt); 427no_route: 428 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 429 return NULL; 430} 431EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); 432 433static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport, 434 const u32 rnd, const u32 synq_hsize) 435{ 436 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1); 437} 438 439#if IS_ENABLED(CONFIG_IPV6) 440#define AF_INET_FAMILY(fam) ((fam) == AF_INET) 441#else 442#define AF_INET_FAMILY(fam) 1 443#endif 444 445struct request_sock *inet_csk_search_req(const struct sock *sk, 446 struct request_sock ***prevp, 447 const __be16 rport, const __be32 raddr, 448 const __be32 laddr) 449{ 450 const struct inet_connection_sock *icsk = inet_csk(sk); 451 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 452 struct request_sock *req, **prev; 453 454 for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd, 455 lopt->nr_table_entries)]; 456 (req = *prev) != NULL; 457 prev = &req->dl_next) { 458 const struct inet_request_sock *ireq = inet_rsk(req); 459 460 if (ireq->rmt_port == rport && 461 ireq->rmt_addr == raddr && 462 ireq->loc_addr == laddr && 463 AF_INET_FAMILY(req->rsk_ops->family)) { 464 WARN_ON(req->sk); 465 *prevp = prev; 466 break; 467 } 468 } 469 470 return req; 471} 472EXPORT_SYMBOL_GPL(inet_csk_search_req); 473 474void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 475 unsigned long timeout) 476{ 477 struct inet_connection_sock *icsk = inet_csk(sk); 478 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 479 const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, 480 lopt->hash_rnd, lopt->nr_table_entries); 481 482 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); 483 inet_csk_reqsk_queue_added(sk, timeout); 484} 485EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); 486 487/* Only thing we need from tcp.h */ 488extern int sysctl_tcp_synack_retries; 489 490 491/* Decide when to expire the request and when to resend SYN-ACK */ 492static inline void syn_ack_recalc(struct request_sock *req, const int thresh, 493 const int max_retries, 494 const u8 rskq_defer_accept, 495 int *expire, int *resend) 496{ 497 if (!rskq_defer_accept) { 498 *expire = req->retrans >= thresh; 499 *resend = 1; 500 return; 501 } 502 *expire = req->retrans >= thresh && 503 (!inet_rsk(req)->acked || req->retrans >= max_retries); 504 /* 505 * Do not resend while waiting for data after ACK, 506 * start to resend on end of deferring period to give 507 * last chance for data or ACK to create established socket. 508 */ 509 *resend = !inet_rsk(req)->acked || 510 req->retrans >= rskq_defer_accept - 1; 511} 512 513void inet_csk_reqsk_queue_prune(struct sock *parent, 514 const unsigned long interval, 515 const unsigned long timeout, 516 const unsigned long max_rto) 517{ 518 struct inet_connection_sock *icsk = inet_csk(parent); 519 struct request_sock_queue *queue = &icsk->icsk_accept_queue; 520 struct listen_sock *lopt = queue->listen_opt; 521 int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; 522 int thresh = max_retries; 523 unsigned long now = jiffies; 524 struct request_sock **reqp, *req; 525 int i, budget; 526 527 if (lopt == NULL || lopt->qlen == 0) 528 return; 529 530 /* Normally all the openreqs are young and become mature 531 * (i.e. converted to established socket) for first timeout. 532 * If synack was not acknowledged for 1 second, it means 533 * one of the following things: synack was lost, ack was lost, 534 * rtt is high or nobody planned to ack (i.e. synflood). 535 * When server is a bit loaded, queue is populated with old 536 * open requests, reducing effective size of queue. 537 * When server is well loaded, queue size reduces to zero 538 * after several minutes of work. It is not synflood, 539 * it is normal operation. The solution is pruning 540 * too old entries overriding normal timeout, when 541 * situation becomes dangerous. 542 * 543 * Essentially, we reserve half of room for young 544 * embrions; and abort old ones without pity, if old 545 * ones are about to clog our table. 546 */ 547 if (lopt->qlen>>(lopt->max_qlen_log-1)) { 548 int young = (lopt->qlen_young<<1); 549 550 while (thresh > 2) { 551 if (lopt->qlen < young) 552 break; 553 thresh--; 554 young <<= 1; 555 } 556 } 557 558 if (queue->rskq_defer_accept) 559 max_retries = queue->rskq_defer_accept; 560 561 budget = 2 * (lopt->nr_table_entries / (timeout / interval)); 562 i = lopt->clock_hand; 563 564 do { 565 reqp=&lopt->syn_table[i]; 566 while ((req = *reqp) != NULL) { 567 if (time_after_eq(now, req->expires)) { 568 int expire = 0, resend = 0; 569 570 syn_ack_recalc(req, thresh, max_retries, 571 queue->rskq_defer_accept, 572 &expire, &resend); 573 req->rsk_ops->syn_ack_timeout(parent, req); 574 if (!expire && 575 (!resend || 576 !req->rsk_ops->rtx_syn_ack(parent, req, NULL) || 577 inet_rsk(req)->acked)) { 578 unsigned long timeo; 579 580 if (req->retrans++ == 0) 581 lopt->qlen_young--; 582 timeo = min((timeout << req->retrans), max_rto); 583 req->expires = now + timeo; 584 reqp = &req->dl_next; 585 continue; 586 } 587 588 /* Drop this request */ 589 inet_csk_reqsk_queue_unlink(parent, req, reqp); 590 reqsk_queue_removed(queue, req); 591 reqsk_free(req); 592 continue; 593 } 594 reqp = &req->dl_next; 595 } 596 597 i = (i + 1) & (lopt->nr_table_entries - 1); 598 599 } while (--budget > 0); 600 601 lopt->clock_hand = i; 602 603 if (lopt->qlen) 604 inet_csk_reset_keepalive_timer(parent, interval); 605} 606EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune); 607 608/** 609 * inet_csk_clone_lock - clone an inet socket, and lock its clone 610 * @sk: the socket to clone 611 * @req: request_sock 612 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) 613 * 614 * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) 615 */ 616struct sock *inet_csk_clone_lock(const struct sock *sk, 617 const struct request_sock *req, 618 const gfp_t priority) 619{ 620 struct sock *newsk = sk_clone_lock(sk, priority); 621 622 if (newsk != NULL) { 623 struct inet_connection_sock *newicsk = inet_csk(newsk); 624 625 newsk->sk_state = TCP_SYN_RECV; 626 newicsk->icsk_bind_hash = NULL; 627 628 inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port; 629 inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port); 630 inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port; 631 newsk->sk_write_space = sk_stream_write_space; 632 633 newicsk->icsk_retransmits = 0; 634 newicsk->icsk_backoff = 0; 635 newicsk->icsk_probes_out = 0; 636 637 /* Deinitialize accept_queue to trap illegal accesses. */ 638 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); 639 640 security_inet_csk_clone(newsk, req); 641 } 642 return newsk; 643} 644EXPORT_SYMBOL_GPL(inet_csk_clone_lock); 645 646/* 647 * At this point, there should be no process reference to this 648 * socket, and thus no user references at all. Therefore we 649 * can assume the socket waitqueue is inactive and nobody will 650 * try to jump onto it. 651 */ 652void inet_csk_destroy_sock(struct sock *sk) 653{ 654 WARN_ON(sk->sk_state != TCP_CLOSE); 655 WARN_ON(!sock_flag(sk, SOCK_DEAD)); 656 657 /* It cannot be in hash table! */ 658 WARN_ON(!sk_unhashed(sk)); 659 660 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ 661 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); 662 663 sk->sk_prot->destroy(sk); 664 665 sk_stream_kill_queues(sk); 666 667 xfrm_sk_free_policy(sk); 668 669 sk_refcnt_debug_release(sk); 670 671 percpu_counter_dec(sk->sk_prot->orphan_count); 672 sock_put(sk); 673} 674EXPORT_SYMBOL(inet_csk_destroy_sock); 675 676int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) 677{ 678 struct inet_sock *inet = inet_sk(sk); 679 struct inet_connection_sock *icsk = inet_csk(sk); 680 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); 681 682 if (rc != 0) 683 return rc; 684 685 sk->sk_max_ack_backlog = 0; 686 sk->sk_ack_backlog = 0; 687 inet_csk_delack_init(sk); 688 689 /* There is race window here: we announce ourselves listening, 690 * but this transition is still not validated by get_port(). 691 * It is OK, because this socket enters to hash table only 692 * after validation is complete. 693 */ 694 sk->sk_state = TCP_LISTEN; 695 if (!sk->sk_prot->get_port(sk, inet->inet_num)) { 696 inet->inet_sport = htons(inet->inet_num); 697 698 sk_dst_reset(sk); 699 sk->sk_prot->hash(sk); 700 701 return 0; 702 } 703 704 sk->sk_state = TCP_CLOSE; 705 __reqsk_queue_destroy(&icsk->icsk_accept_queue); 706 return -EADDRINUSE; 707} 708EXPORT_SYMBOL_GPL(inet_csk_listen_start); 709 710/* 711 * This routine closes sockets which have been at least partially 712 * opened, but not yet accepted. 713 */ 714void inet_csk_listen_stop(struct sock *sk) 715{ 716 struct inet_connection_sock *icsk = inet_csk(sk); 717 struct request_sock *acc_req; 718 struct request_sock *req; 719 720 inet_csk_delete_keepalive_timer(sk); 721 722 /* make all the listen_opt local to us */ 723 acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue); 724 725 /* Following specs, it would be better either to send FIN 726 * (and enter FIN-WAIT-1, it is normal close) 727 * or to send active reset (abort). 728 * Certainly, it is pretty dangerous while synflood, but it is 729 * bad justification for our negligence 8) 730 * To be honest, we are not able to make either 731 * of the variants now. --ANK 732 */ 733 reqsk_queue_destroy(&icsk->icsk_accept_queue); 734 735 while ((req = acc_req) != NULL) { 736 struct sock *child = req->sk; 737 738 acc_req = req->dl_next; 739 740 local_bh_disable(); 741 bh_lock_sock(child); 742 WARN_ON(sock_owned_by_user(child)); 743 sock_hold(child); 744 745 sk->sk_prot->disconnect(child, O_NONBLOCK); 746 747 sock_orphan(child); 748 749 percpu_counter_inc(sk->sk_prot->orphan_count); 750 751 inet_csk_destroy_sock(child); 752 753 bh_unlock_sock(child); 754 local_bh_enable(); 755 sock_put(child); 756 757 sk_acceptq_removed(sk); 758 __reqsk_free(req); 759 } 760 WARN_ON(sk->sk_ack_backlog); 761} 762EXPORT_SYMBOL_GPL(inet_csk_listen_stop); 763 764void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) 765{ 766 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; 767 const struct inet_sock *inet = inet_sk(sk); 768 769 sin->sin_family = AF_INET; 770 sin->sin_addr.s_addr = inet->inet_daddr; 771 sin->sin_port = inet->inet_dport; 772} 773EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); 774 775#ifdef CONFIG_COMPAT 776int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 777 char __user *optval, int __user *optlen) 778{ 779 const struct inet_connection_sock *icsk = inet_csk(sk); 780 781 if (icsk->icsk_af_ops->compat_getsockopt != NULL) 782 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname, 783 optval, optlen); 784 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 785 optval, optlen); 786} 787EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt); 788 789int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 790 char __user *optval, unsigned int optlen) 791{ 792 const struct inet_connection_sock *icsk = inet_csk(sk); 793 794 if (icsk->icsk_af_ops->compat_setsockopt != NULL) 795 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname, 796 optval, optlen); 797 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 798 optval, optlen); 799} 800EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt); 801#endif 802