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.
6 * Support for INET connection oriented protocols.
8 * Authors: See the TCP sources
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.
16 #include <linux/module.h>
17 #include <linux/jhash.h>
19 #include <net/inet_connection_sock.h>
20 #include <net/inet_hashtables.h>
21 #include <net/inet_timewait_sock.h>
23 #include <net/route.h>
24 #include <net/tcp_states.h>
29 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
30 EXPORT_SYMBOL(inet_csk_timer_bug_msg);
33 void inet_get_local_port_range(struct net *net, int *low, int *high)
38 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
40 *low = net->ipv4.ip_local_ports.range[0];
41 *high = net->ipv4.ip_local_ports.range[1];
42 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
44 EXPORT_SYMBOL(inet_get_local_port_range);
46 int inet_csk_bind_conflict(const struct sock *sk,
47 const struct inet_bind_bucket *tb, bool relax)
50 int reuse = sk->sk_reuse;
51 int reuseport = sk->sk_reuseport;
52 kuid_t uid = sock_i_uid((struct sock *)sk);
55 * Unlike other sk lookup places we do not check
56 * for sk_net here, since _all_ the socks listed
57 * in tb->owners list belong to the same net - the
58 * one this bucket belongs to.
61 sk_for_each_bound(sk2, &tb->owners) {
63 !inet_v6_ipv6only(sk2) &&
64 (!sk->sk_bound_dev_if ||
65 !sk2->sk_bound_dev_if ||
66 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
67 if ((!reuse || !sk2->sk_reuse ||
68 sk2->sk_state == TCP_LISTEN) &&
69 (!reuseport || !sk2->sk_reuseport ||
70 (sk2->sk_state != TCP_TIME_WAIT &&
71 !uid_eq(uid, sock_i_uid(sk2))))) {
73 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
74 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
77 if (!relax && reuse && sk2->sk_reuse &&
78 sk2->sk_state != TCP_LISTEN) {
80 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
81 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
88 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
90 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
93 kuid_t uid = sock_i_uid(sk);
95 if (hlist_empty(&tb->owners)) {
96 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
100 if (sk->sk_reuseport) {
101 tb->fastreuseport = 1;
104 tb->fastreuseport = 0;
107 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
109 if (tb->fastreuseport &&
110 (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
111 tb->fastreuseport = 0;
115 /* Obtain a reference to a local port for the given sock,
116 * if snum is zero it means select any available local port.
118 int inet_csk_get_port(struct sock *sk, unsigned short snum)
120 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
121 struct inet_bind_hashbucket *head;
122 struct inet_bind_bucket *tb;
123 int ret, attempts = 5;
124 struct net *net = sock_net(sk);
125 int smallest_size = -1, smallest_rover;
126 kuid_t uid = sock_i_uid(sk);
127 int attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
131 int remaining, rover, low, high;
134 inet_get_local_port_range(net, &low, &high);
136 int half = low + ((high - low) >> 1);
138 if (attempt_half == 1)
143 remaining = (high - low) + 1;
144 smallest_rover = rover = prandom_u32() % remaining + low;
148 if (inet_is_local_reserved_port(net, rover))
150 head = &hashinfo->bhash[inet_bhashfn(net, rover,
151 hashinfo->bhash_size)];
152 spin_lock(&head->lock);
153 inet_bind_bucket_for_each(tb, &head->chain)
154 if (net_eq(ib_net(tb), net) && tb->port == rover) {
155 if (((tb->fastreuse > 0 &&
157 sk->sk_state != TCP_LISTEN) ||
158 (tb->fastreuseport > 0 &&
160 uid_eq(tb->fastuid, uid))) &&
161 (tb->num_owners < smallest_size || smallest_size == -1)) {
162 smallest_size = tb->num_owners;
163 smallest_rover = rover;
165 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
173 spin_unlock(&head->lock);
177 } while (--remaining > 0);
179 /* Exhausted local port range during search? It is not
180 * possible for us to be holding one of the bind hash
181 * locks if this test triggers, because if 'remaining'
182 * drops to zero, we broke out of the do/while loop at
183 * the top level, not from the 'break;' statement.
186 if (remaining <= 0) {
187 if (smallest_size != -1) {
188 snum = smallest_rover;
191 if (attempt_half == 1) {
192 /* OK we now try the upper half of the range */
198 /* OK, here is the one we will use. HEAD is
199 * non-NULL and we hold it's mutex.
204 head = &hashinfo->bhash[inet_bhashfn(net, snum,
205 hashinfo->bhash_size)];
206 spin_lock(&head->lock);
207 inet_bind_bucket_for_each(tb, &head->chain)
208 if (net_eq(ib_net(tb), net) && tb->port == snum)
214 if (!hlist_empty(&tb->owners)) {
215 if (sk->sk_reuse == SK_FORCE_REUSE)
218 if (((tb->fastreuse > 0 &&
219 sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
220 (tb->fastreuseport > 0 &&
221 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
222 smallest_size == -1) {
226 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
227 if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
228 (tb->fastreuseport > 0 &&
229 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
230 smallest_size != -1 && --attempts >= 0) {
231 spin_unlock(&head->lock);
241 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
242 net, head, snum)) == NULL)
245 inet_csk_update_fastreuse(tb, sk);
248 if (!inet_csk(sk)->icsk_bind_hash)
249 inet_bind_hash(sk, tb, snum);
250 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
254 spin_unlock(&head->lock);
259 EXPORT_SYMBOL_GPL(inet_csk_get_port);
262 * Wait for an incoming connection, avoid race conditions. This must be called
263 * with the socket locked.
265 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
267 struct inet_connection_sock *icsk = inet_csk(sk);
272 * True wake-one mechanism for incoming connections: only
273 * one process gets woken up, not the 'whole herd'.
274 * Since we do not 'race & poll' for established sockets
275 * anymore, the common case will execute the loop only once.
277 * Subtle issue: "add_wait_queue_exclusive()" will be added
278 * after any current non-exclusive waiters, and we know that
279 * it will always _stay_ after any new non-exclusive waiters
280 * because all non-exclusive waiters are added at the
281 * beginning of the wait-queue. As such, it's ok to "drop"
282 * our exclusiveness temporarily when we get woken up without
283 * having to remove and re-insert us on the wait queue.
286 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
289 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
290 timeo = schedule_timeout(timeo);
291 sched_annotate_sleep();
294 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
297 if (sk->sk_state != TCP_LISTEN)
299 err = sock_intr_errno(timeo);
300 if (signal_pending(current))
306 finish_wait(sk_sleep(sk), &wait);
311 * This will accept the next outstanding connection.
313 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
315 struct inet_connection_sock *icsk = inet_csk(sk);
316 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
317 struct request_sock *req;
323 /* We need to make sure that this socket is listening,
324 * and that it has something pending.
327 if (sk->sk_state != TCP_LISTEN)
330 /* Find already established connection */
331 if (reqsk_queue_empty(queue)) {
332 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
334 /* If this is a non blocking socket don't sleep */
339 error = inet_csk_wait_for_connect(sk, timeo);
343 req = reqsk_queue_remove(queue, sk);
346 if (sk->sk_protocol == IPPROTO_TCP &&
347 tcp_rsk(req)->tfo_listener) {
348 spin_lock_bh(&queue->fastopenq.lock);
349 if (tcp_rsk(req)->tfo_listener) {
350 /* We are still waiting for the final ACK from 3WHS
351 * so can't free req now. Instead, we set req->sk to
352 * NULL to signify that the child socket is taken
353 * so reqsk_fastopen_remove() will free the req
354 * when 3WHS finishes (or is aborted).
359 spin_unlock_bh(&queue->fastopenq.lock);
372 EXPORT_SYMBOL(inet_csk_accept);
375 * Using different timers for retransmit, delayed acks and probes
376 * We may wish use just one timer maintaining a list of expire jiffies
379 void inet_csk_init_xmit_timers(struct sock *sk,
380 void (*retransmit_handler)(unsigned long),
381 void (*delack_handler)(unsigned long),
382 void (*keepalive_handler)(unsigned long))
384 struct inet_connection_sock *icsk = inet_csk(sk);
386 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
388 setup_timer(&icsk->icsk_delack_timer, delack_handler,
390 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
391 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
393 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
395 void inet_csk_clear_xmit_timers(struct sock *sk)
397 struct inet_connection_sock *icsk = inet_csk(sk);
399 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
401 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
402 sk_stop_timer(sk, &icsk->icsk_delack_timer);
403 sk_stop_timer(sk, &sk->sk_timer);
405 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
407 void inet_csk_delete_keepalive_timer(struct sock *sk)
409 sk_stop_timer(sk, &sk->sk_timer);
411 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
413 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
415 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
417 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
419 struct dst_entry *inet_csk_route_req(const struct sock *sk,
421 const struct request_sock *req)
423 const struct inet_request_sock *ireq = inet_rsk(req);
424 struct net *net = read_pnet(&ireq->ireq_net);
425 struct ip_options_rcu *opt;
428 opt = ireq_opt_deref(ireq);
430 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
431 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
432 sk->sk_protocol, inet_sk_flowi_flags(sk),
433 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
434 ireq->ir_loc_addr, ireq->ir_rmt_port,
435 htons(ireq->ir_num));
436 security_req_classify_flow(req, flowi4_to_flowi(fl4));
437 rt = ip_route_output_flow(net, fl4, sk);
440 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
447 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
450 EXPORT_SYMBOL_GPL(inet_csk_route_req);
452 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
454 const struct request_sock *req)
456 const struct inet_request_sock *ireq = inet_rsk(req);
457 struct net *net = read_pnet(&ireq->ireq_net);
458 struct inet_sock *newinet = inet_sk(newsk);
459 struct ip_options_rcu *opt;
463 opt = rcu_dereference(ireq->ireq_opt);
464 fl4 = &newinet->cork.fl.u.ip4;
466 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
467 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
468 sk->sk_protocol, inet_sk_flowi_flags(sk),
469 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
470 ireq->ir_loc_addr, ireq->ir_rmt_port,
471 htons(ireq->ir_num));
472 security_req_classify_flow(req, flowi4_to_flowi(fl4));
473 rt = ip_route_output_flow(net, fl4, sk);
476 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
483 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
486 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
488 #if IS_ENABLED(CONFIG_IPV6)
489 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
491 #define AF_INET_FAMILY(fam) true
494 /* Only thing we need from tcp.h */
495 extern int sysctl_tcp_synack_retries;
498 /* Decide when to expire the request and when to resend SYN-ACK */
499 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
500 const int max_retries,
501 const u8 rskq_defer_accept,
502 int *expire, int *resend)
504 if (!rskq_defer_accept) {
505 *expire = req->num_timeout >= thresh;
509 *expire = req->num_timeout >= thresh &&
510 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
512 * Do not resend while waiting for data after ACK,
513 * start to resend on end of deferring period to give
514 * last chance for data or ACK to create established socket.
516 *resend = !inet_rsk(req)->acked ||
517 req->num_timeout >= rskq_defer_accept - 1;
520 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
522 int err = req->rsk_ops->rtx_syn_ack(parent, req);
528 EXPORT_SYMBOL(inet_rtx_syn_ack);
530 /* return true if req was found in the ehash table */
531 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
532 struct request_sock *req)
534 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
537 if (sk_hashed(req_to_sk(req))) {
538 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
541 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
544 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
549 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
551 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
552 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
556 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
558 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
560 inet_csk_reqsk_queue_drop(sk, req);
563 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
565 static void reqsk_timer_handler(unsigned long data)
567 struct request_sock *req = (struct request_sock *)data;
568 struct sock *sk_listener = req->rsk_listener;
569 struct inet_connection_sock *icsk = inet_csk(sk_listener);
570 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
571 int qlen, expire = 0, resend = 0;
572 int max_retries, thresh;
575 if (sk_state_load(sk_listener) != TCP_LISTEN)
578 max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
579 thresh = max_retries;
580 /* Normally all the openreqs are young and become mature
581 * (i.e. converted to established socket) for first timeout.
582 * If synack was not acknowledged for 1 second, it means
583 * one of the following things: synack was lost, ack was lost,
584 * rtt is high or nobody planned to ack (i.e. synflood).
585 * When server is a bit loaded, queue is populated with old
586 * open requests, reducing effective size of queue.
587 * When server is well loaded, queue size reduces to zero
588 * after several minutes of work. It is not synflood,
589 * it is normal operation. The solution is pruning
590 * too old entries overriding normal timeout, when
591 * situation becomes dangerous.
593 * Essentially, we reserve half of room for young
594 * embrions; and abort old ones without pity, if old
595 * ones are about to clog our table.
597 qlen = reqsk_queue_len(queue);
598 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
599 int young = reqsk_queue_len_young(queue) << 1;
608 defer_accept = READ_ONCE(queue->rskq_defer_accept);
610 max_retries = defer_accept;
611 syn_ack_recalc(req, thresh, max_retries, defer_accept,
613 req->rsk_ops->syn_ack_timeout(req);
616 !inet_rtx_syn_ack(sk_listener, req) ||
617 inet_rsk(req)->acked)) {
620 if (req->num_timeout++ == 0)
621 atomic_dec(&queue->young);
622 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
623 mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
627 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
630 static void reqsk_queue_hash_req(struct request_sock *req,
631 unsigned long timeout)
633 req->num_retrans = 0;
634 req->num_timeout = 0;
637 setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
638 mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
640 inet_ehash_insert(req_to_sk(req), NULL);
641 /* before letting lookups find us, make sure all req fields
642 * are committed to memory and refcnt initialized.
645 atomic_set(&req->rsk_refcnt, 2 + 1);
648 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
649 unsigned long timeout)
651 reqsk_queue_hash_req(req, timeout);
652 inet_csk_reqsk_queue_added(sk);
654 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
657 * inet_csk_clone_lock - clone an inet socket, and lock its clone
658 * @sk: the socket to clone
660 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
662 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
664 struct sock *inet_csk_clone_lock(const struct sock *sk,
665 const struct request_sock *req,
666 const gfp_t priority)
668 struct sock *newsk = sk_clone_lock(sk, priority);
671 struct inet_connection_sock *newicsk = inet_csk(newsk);
673 newsk->sk_state = TCP_SYN_RECV;
674 newicsk->icsk_bind_hash = NULL;
676 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
677 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
678 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
679 newsk->sk_write_space = sk_stream_write_space;
681 inet_sk(newsk)->mc_list = NULL;
683 newsk->sk_mark = inet_rsk(req)->ir_mark;
684 atomic64_set(&newsk->sk_cookie,
685 atomic64_read(&inet_rsk(req)->ir_cookie));
687 newicsk->icsk_retransmits = 0;
688 newicsk->icsk_backoff = 0;
689 newicsk->icsk_probes_out = 0;
691 /* Deinitialize accept_queue to trap illegal accesses. */
692 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
694 security_inet_csk_clone(newsk, req);
698 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
701 * At this point, there should be no process reference to this
702 * socket, and thus no user references at all. Therefore we
703 * can assume the socket waitqueue is inactive and nobody will
704 * try to jump onto it.
706 void inet_csk_destroy_sock(struct sock *sk)
708 WARN_ON(sk->sk_state != TCP_CLOSE);
709 WARN_ON(!sock_flag(sk, SOCK_DEAD));
711 /* It cannot be in hash table! */
712 WARN_ON(!sk_unhashed(sk));
714 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
715 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
717 sk->sk_prot->destroy(sk);
719 sk_stream_kill_queues(sk);
721 xfrm_sk_free_policy(sk);
723 sk_refcnt_debug_release(sk);
725 percpu_counter_dec(sk->sk_prot->orphan_count);
728 EXPORT_SYMBOL(inet_csk_destroy_sock);
730 /* This function allows to force a closure of a socket after the call to
731 * tcp/dccp_create_openreq_child().
733 void inet_csk_prepare_forced_close(struct sock *sk)
734 __releases(&sk->sk_lock.slock)
736 /* sk_clone_lock locked the socket and set refcnt to 2 */
740 /* The below has to be done to allow calling inet_csk_destroy_sock */
741 sock_set_flag(sk, SOCK_DEAD);
742 percpu_counter_inc(sk->sk_prot->orphan_count);
743 inet_sk(sk)->inet_num = 0;
745 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
747 int inet_csk_listen_start(struct sock *sk, int backlog)
749 struct inet_connection_sock *icsk = inet_csk(sk);
750 struct inet_sock *inet = inet_sk(sk);
752 reqsk_queue_alloc(&icsk->icsk_accept_queue);
754 sk->sk_max_ack_backlog = backlog;
755 sk->sk_ack_backlog = 0;
756 inet_csk_delack_init(sk);
758 /* There is race window here: we announce ourselves listening,
759 * but this transition is still not validated by get_port().
760 * It is OK, because this socket enters to hash table only
761 * after validation is complete.
763 sk_state_store(sk, TCP_LISTEN);
764 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
765 inet->inet_sport = htons(inet->inet_num);
768 sk->sk_prot->hash(sk);
773 sk->sk_state = TCP_CLOSE;
776 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
778 static void inet_child_forget(struct sock *sk, struct request_sock *req,
781 sk->sk_prot->disconnect(child, O_NONBLOCK);
785 percpu_counter_inc(sk->sk_prot->orphan_count);
787 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
788 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
789 BUG_ON(sk != req->rsk_listener);
791 /* Paranoid, to prevent race condition if
792 * an inbound pkt destined for child is
793 * blocked by sock lock in tcp_v4_rcv().
794 * Also to satisfy an assertion in
795 * tcp_v4_destroy_sock().
797 tcp_sk(child)->fastopen_rsk = NULL;
799 inet_csk_destroy_sock(child);
802 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
803 struct request_sock *req,
806 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
808 spin_lock(&queue->rskq_lock);
809 if (unlikely(sk->sk_state != TCP_LISTEN)) {
810 inet_child_forget(sk, req, child);
815 if (queue->rskq_accept_head == NULL)
816 queue->rskq_accept_head = req;
818 queue->rskq_accept_tail->dl_next = req;
819 queue->rskq_accept_tail = req;
820 sk_acceptq_added(sk);
822 spin_unlock(&queue->rskq_lock);
825 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
827 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
828 struct request_sock *req, bool own_req)
831 inet_csk_reqsk_queue_drop(sk, req);
832 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
833 if (inet_csk_reqsk_queue_add(sk, req, child))
836 /* Too bad, another child took ownership of the request, undo. */
837 bh_unlock_sock(child);
841 EXPORT_SYMBOL(inet_csk_complete_hashdance);
844 * This routine closes sockets which have been at least partially
845 * opened, but not yet accepted.
847 void inet_csk_listen_stop(struct sock *sk)
849 struct inet_connection_sock *icsk = inet_csk(sk);
850 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
851 struct request_sock *next, *req;
853 /* Following specs, it would be better either to send FIN
854 * (and enter FIN-WAIT-1, it is normal close)
855 * or to send active reset (abort).
856 * Certainly, it is pretty dangerous while synflood, but it is
857 * bad justification for our negligence 8)
858 * To be honest, we are not able to make either
859 * of the variants now. --ANK
861 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
862 struct sock *child = req->sk;
866 WARN_ON(sock_owned_by_user(child));
869 inet_child_forget(sk, req, child);
871 bh_unlock_sock(child);
877 if (queue->fastopenq.rskq_rst_head) {
878 /* Free all the reqs queued in rskq_rst_head. */
879 spin_lock_bh(&queue->fastopenq.lock);
880 req = queue->fastopenq.rskq_rst_head;
881 queue->fastopenq.rskq_rst_head = NULL;
882 spin_unlock_bh(&queue->fastopenq.lock);
883 while (req != NULL) {
889 WARN_ON_ONCE(sk->sk_ack_backlog);
891 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
893 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
895 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
896 const struct inet_sock *inet = inet_sk(sk);
898 sin->sin_family = AF_INET;
899 sin->sin_addr.s_addr = inet->inet_daddr;
900 sin->sin_port = inet->inet_dport;
902 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
905 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
906 char __user *optval, int __user *optlen)
908 const struct inet_connection_sock *icsk = inet_csk(sk);
910 if (icsk->icsk_af_ops->compat_getsockopt)
911 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
913 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
916 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
918 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
919 char __user *optval, unsigned int optlen)
921 const struct inet_connection_sock *icsk = inet_csk(sk);
923 if (icsk->icsk_af_ops->compat_setsockopt)
924 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
926 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
929 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
932 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
934 const struct inet_sock *inet = inet_sk(sk);
935 const struct ip_options_rcu *inet_opt;
936 __be32 daddr = inet->inet_daddr;
941 inet_opt = rcu_dereference(inet->inet_opt);
942 if (inet_opt && inet_opt->opt.srr)
943 daddr = inet_opt->opt.faddr;
945 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
946 inet->inet_saddr, inet->inet_dport,
947 inet->inet_sport, sk->sk_protocol,
948 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
952 sk_setup_caps(sk, &rt->dst);
958 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
960 struct dst_entry *dst = __sk_dst_check(sk, 0);
961 struct inet_sock *inet = inet_sk(sk);
964 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
968 dst->ops->update_pmtu(dst, sk, NULL, mtu);
970 dst = __sk_dst_check(sk, 0);
972 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
976 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);