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>
27 #include <net/sock_reuseport.h>
30 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
31 EXPORT_SYMBOL(inet_csk_timer_bug_msg);
34 void inet_get_local_port_range(struct net *net, int *low, int *high)
39 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
41 *low = net->ipv4.ip_local_ports.range[0];
42 *high = net->ipv4.ip_local_ports.range[1];
43 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
45 EXPORT_SYMBOL(inet_get_local_port_range);
47 int inet_csk_bind_conflict(const struct sock *sk,
48 const struct inet_bind_bucket *tb, bool relax)
51 int reuse = sk->sk_reuse;
52 int reuseport = sk->sk_reuseport;
53 kuid_t uid = sock_i_uid((struct sock *)sk);
56 * Unlike other sk lookup places we do not check
57 * for sk_net here, since _all_ the socks listed
58 * in tb->owners list belong to the same net - the
59 * one this bucket belongs to.
62 sk_for_each_bound(sk2, &tb->owners) {
64 !inet_v6_ipv6only(sk2) &&
65 (!sk->sk_bound_dev_if ||
66 !sk2->sk_bound_dev_if ||
67 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
68 if ((!reuse || !sk2->sk_reuse ||
69 sk2->sk_state == TCP_LISTEN) &&
70 (!reuseport || !sk2->sk_reuseport ||
71 rcu_access_pointer(sk->sk_reuseport_cb) ||
72 (sk2->sk_state != TCP_TIME_WAIT &&
73 !uid_eq(uid, sock_i_uid(sk2))))) {
75 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
76 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
79 if (!relax && reuse && sk2->sk_reuse &&
80 sk2->sk_state != TCP_LISTEN) {
82 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
83 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
90 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
92 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
95 kuid_t uid = sock_i_uid(sk);
96 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
98 if (!hlist_empty(&tb->owners)) {
101 if (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))
102 tb->fastreuseport = 0;
104 tb->fastreuse = reuse;
105 if (sk->sk_reuseport) {
106 tb->fastreuseport = 1;
109 tb->fastreuseport = 0;
114 /* Obtain a reference to a local port for the given sock,
115 * if snum is zero it means select any available local port.
116 * We try to allocate an odd port (and leave even ports for connect())
118 int inet_csk_get_port(struct sock *sk, unsigned short snum)
120 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
121 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
122 int ret = 1, attempts = 5, port = snum;
123 int smallest_size = -1, smallest_port;
124 struct inet_bind_hashbucket *head;
125 struct net *net = sock_net(sk);
126 int i, low, high, attempt_half;
127 struct inet_bind_bucket *tb;
128 kuid_t uid = sock_i_uid(sk);
129 u32 remaining, offset;
133 head = &hinfo->bhash[inet_bhashfn(net, port,
135 spin_lock_bh(&head->lock);
136 inet_bind_bucket_for_each(tb, &head->chain)
137 if (net_eq(ib_net(tb), net) && tb->port == port)
143 attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
145 inet_get_local_port_range(net, &low, &high);
146 high++; /* [32768, 60999] -> [32768, 61000[ */
150 int half = low + (((high - low) >> 2) << 1);
152 if (attempt_half == 1)
157 remaining = high - low;
158 if (likely(remaining > 1))
161 offset = prandom_u32() % remaining;
162 /* __inet_hash_connect() favors ports having @low parity
163 * We do the opposite to not pollute connect() users.
167 smallest_port = low; /* avoid compiler warning */
171 for (i = 0; i < remaining; i += 2, port += 2) {
172 if (unlikely(port >= high))
174 if (inet_is_local_reserved_port(net, port))
176 head = &hinfo->bhash[inet_bhashfn(net, port,
178 spin_lock_bh(&head->lock);
179 inet_bind_bucket_for_each(tb, &head->chain)
180 if (net_eq(ib_net(tb), net) && tb->port == port) {
181 if (((tb->fastreuse > 0 && reuse) ||
182 (tb->fastreuseport > 0 &&
184 !rcu_access_pointer(sk->sk_reuseport_cb) &&
185 uid_eq(tb->fastuid, uid))) &&
186 (tb->num_owners < smallest_size || smallest_size == -1)) {
187 smallest_size = tb->num_owners;
188 smallest_port = port;
190 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false))
196 spin_unlock_bh(&head->lock);
200 if (smallest_size != -1) {
201 port = smallest_port;
206 goto other_parity_scan;
208 if (attempt_half == 1) {
209 /* OK we now try the upper half of the range */
211 goto other_half_scan;
216 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
221 if (!hlist_empty(&tb->owners)) {
222 if (sk->sk_reuse == SK_FORCE_REUSE)
225 if (((tb->fastreuse > 0 && reuse) ||
226 (tb->fastreuseport > 0 &&
227 !rcu_access_pointer(sk->sk_reuseport_cb) &&
228 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
231 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
233 (tb->fastreuseport > 0 &&
235 !rcu_access_pointer(sk->sk_reuseport_cb) &&
236 uid_eq(tb->fastuid, uid))) &&
237 smallest_size != -1 && --attempts >= 0) {
238 spin_unlock_bh(&head->lock);
245 inet_csk_update_fastreuse(tb, sk);
248 if (!inet_csk(sk)->icsk_bind_hash)
249 inet_bind_hash(sk, tb, port);
250 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
254 spin_unlock_bh(&head->lock);
257 EXPORT_SYMBOL_GPL(inet_csk_get_port);
260 * Wait for an incoming connection, avoid race conditions. This must be called
261 * with the socket locked.
263 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
265 struct inet_connection_sock *icsk = inet_csk(sk);
270 * True wake-one mechanism for incoming connections: only
271 * one process gets woken up, not the 'whole herd'.
272 * Since we do not 'race & poll' for established sockets
273 * anymore, the common case will execute the loop only once.
275 * Subtle issue: "add_wait_queue_exclusive()" will be added
276 * after any current non-exclusive waiters, and we know that
277 * it will always _stay_ after any new non-exclusive waiters
278 * because all non-exclusive waiters are added at the
279 * beginning of the wait-queue. As such, it's ok to "drop"
280 * our exclusiveness temporarily when we get woken up without
281 * having to remove and re-insert us on the wait queue.
284 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
287 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
288 timeo = schedule_timeout(timeo);
289 sched_annotate_sleep();
292 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
295 if (sk->sk_state != TCP_LISTEN)
297 err = sock_intr_errno(timeo);
298 if (signal_pending(current))
304 finish_wait(sk_sleep(sk), &wait);
309 * This will accept the next outstanding connection.
311 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
313 struct inet_connection_sock *icsk = inet_csk(sk);
314 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
315 struct request_sock *req;
321 /* We need to make sure that this socket is listening,
322 * and that it has something pending.
325 if (sk->sk_state != TCP_LISTEN)
328 /* Find already established connection */
329 if (reqsk_queue_empty(queue)) {
330 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
332 /* If this is a non blocking socket don't sleep */
337 error = inet_csk_wait_for_connect(sk, timeo);
341 req = reqsk_queue_remove(queue, sk);
344 if (sk->sk_protocol == IPPROTO_TCP &&
345 tcp_rsk(req)->tfo_listener) {
346 spin_lock_bh(&queue->fastopenq.lock);
347 if (tcp_rsk(req)->tfo_listener) {
348 /* We are still waiting for the final ACK from 3WHS
349 * so can't free req now. Instead, we set req->sk to
350 * NULL to signify that the child socket is taken
351 * so reqsk_fastopen_remove() will free the req
352 * when 3WHS finishes (or is aborted).
357 spin_unlock_bh(&queue->fastopenq.lock);
370 EXPORT_SYMBOL(inet_csk_accept);
373 * Using different timers for retransmit, delayed acks and probes
374 * We may wish use just one timer maintaining a list of expire jiffies
377 void inet_csk_init_xmit_timers(struct sock *sk,
378 void (*retransmit_handler)(unsigned long),
379 void (*delack_handler)(unsigned long),
380 void (*keepalive_handler)(unsigned long))
382 struct inet_connection_sock *icsk = inet_csk(sk);
384 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
386 setup_timer(&icsk->icsk_delack_timer, delack_handler,
388 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
389 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
391 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
393 void inet_csk_clear_xmit_timers(struct sock *sk)
395 struct inet_connection_sock *icsk = inet_csk(sk);
397 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
399 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
400 sk_stop_timer(sk, &icsk->icsk_delack_timer);
401 sk_stop_timer(sk, &sk->sk_timer);
403 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
405 void inet_csk_delete_keepalive_timer(struct sock *sk)
407 sk_stop_timer(sk, &sk->sk_timer);
409 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
411 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
413 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
415 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
417 struct dst_entry *inet_csk_route_req(const struct sock *sk,
419 const struct request_sock *req)
421 const struct inet_request_sock *ireq = inet_rsk(req);
422 struct net *net = read_pnet(&ireq->ireq_net);
423 struct ip_options_rcu *opt;
427 opt = rcu_dereference(ireq->ireq_opt);
429 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
430 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
431 sk->sk_protocol, inet_sk_flowi_flags(sk),
432 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
433 ireq->ir_loc_addr, ireq->ir_rmt_port,
434 htons(ireq->ir_num));
435 security_req_classify_flow(req, flowi4_to_flowi(fl4));
436 rt = ip_route_output_flow(net, fl4, sk);
439 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
448 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
451 EXPORT_SYMBOL_GPL(inet_csk_route_req);
453 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
455 const struct request_sock *req)
457 const struct inet_request_sock *ireq = inet_rsk(req);
458 struct net *net = read_pnet(&ireq->ireq_net);
459 struct inet_sock *newinet = inet_sk(newsk);
460 struct ip_options_rcu *opt;
464 opt = rcu_dereference(ireq->ireq_opt);
465 fl4 = &newinet->cork.fl.u.ip4;
467 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
468 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
469 sk->sk_protocol, inet_sk_flowi_flags(sk),
470 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
471 ireq->ir_loc_addr, ireq->ir_rmt_port,
472 htons(ireq->ir_num));
473 security_req_classify_flow(req, flowi4_to_flowi(fl4));
474 rt = ip_route_output_flow(net, fl4, sk);
477 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
484 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
487 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
489 #if IS_ENABLED(CONFIG_IPV6)
490 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
492 #define AF_INET_FAMILY(fam) true
495 /* Decide when to expire the request and when to resend SYN-ACK */
496 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
497 const int max_retries,
498 const u8 rskq_defer_accept,
499 int *expire, int *resend)
501 if (!rskq_defer_accept) {
502 *expire = req->num_timeout >= thresh;
506 *expire = req->num_timeout >= thresh &&
507 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
509 * Do not resend while waiting for data after ACK,
510 * start to resend on end of deferring period to give
511 * last chance for data or ACK to create established socket.
513 *resend = !inet_rsk(req)->acked ||
514 req->num_timeout >= rskq_defer_accept - 1;
517 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
519 int err = req->rsk_ops->rtx_syn_ack(parent, req);
525 EXPORT_SYMBOL(inet_rtx_syn_ack);
527 /* return true if req was found in the ehash table */
528 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
529 struct request_sock *req)
531 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
534 if (sk_hashed(req_to_sk(req))) {
535 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
538 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
541 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
546 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
548 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
549 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
553 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
555 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
557 inet_csk_reqsk_queue_drop(sk, req);
560 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
562 static void reqsk_timer_handler(unsigned long data)
564 struct request_sock *req = (struct request_sock *)data;
565 struct sock *sk_listener = req->rsk_listener;
566 struct net *net = sock_net(sk_listener);
567 struct inet_connection_sock *icsk = inet_csk(sk_listener);
568 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
569 int qlen, expire = 0, resend = 0;
570 int max_retries, thresh;
573 if (sk_state_load(sk_listener) != TCP_LISTEN)
576 max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
577 thresh = max_retries;
578 /* Normally all the openreqs are young and become mature
579 * (i.e. converted to established socket) for first timeout.
580 * If synack was not acknowledged for 1 second, it means
581 * one of the following things: synack was lost, ack was lost,
582 * rtt is high or nobody planned to ack (i.e. synflood).
583 * When server is a bit loaded, queue is populated with old
584 * open requests, reducing effective size of queue.
585 * When server is well loaded, queue size reduces to zero
586 * after several minutes of work. It is not synflood,
587 * it is normal operation. The solution is pruning
588 * too old entries overriding normal timeout, when
589 * situation becomes dangerous.
591 * Essentially, we reserve half of room for young
592 * embrions; and abort old ones without pity, if old
593 * ones are about to clog our table.
595 qlen = reqsk_queue_len(queue);
596 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
597 int young = reqsk_queue_len_young(queue) << 1;
606 defer_accept = READ_ONCE(queue->rskq_defer_accept);
608 max_retries = defer_accept;
609 syn_ack_recalc(req, thresh, max_retries, defer_accept,
611 req->rsk_ops->syn_ack_timeout(req);
614 !inet_rtx_syn_ack(sk_listener, req) ||
615 inet_rsk(req)->acked)) {
618 if (req->num_timeout++ == 0)
619 atomic_dec(&queue->young);
620 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
621 mod_timer(&req->rsk_timer, jiffies + timeo);
625 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
628 static void reqsk_queue_hash_req(struct request_sock *req,
629 unsigned long timeout)
631 req->num_retrans = 0;
632 req->num_timeout = 0;
635 setup_pinned_timer(&req->rsk_timer, reqsk_timer_handler,
637 mod_timer(&req->rsk_timer, jiffies + timeout);
639 inet_ehash_insert(req_to_sk(req), NULL);
640 /* before letting lookups find us, make sure all req fields
641 * are committed to memory and refcnt initialized.
644 atomic_set(&req->rsk_refcnt, 2 + 1);
647 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
648 unsigned long timeout)
650 reqsk_queue_hash_req(req, timeout);
651 inet_csk_reqsk_queue_added(sk);
653 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
656 * inet_csk_clone_lock - clone an inet socket, and lock its clone
657 * @sk: the socket to clone
659 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
661 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
663 struct sock *inet_csk_clone_lock(const struct sock *sk,
664 const struct request_sock *req,
665 const gfp_t priority)
667 struct sock *newsk = sk_clone_lock(sk, priority);
670 struct inet_connection_sock *newicsk = inet_csk(newsk);
672 newsk->sk_state = TCP_SYN_RECV;
673 newicsk->icsk_bind_hash = NULL;
675 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
676 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
677 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
678 newsk->sk_write_space = sk_stream_write_space;
680 /* listeners have SOCK_RCU_FREE, not the children */
681 sock_reset_flag(newsk, SOCK_RCU_FREE);
683 inet_sk(newsk)->mc_list = NULL;
685 newsk->sk_mark = inet_rsk(req)->ir_mark;
686 atomic64_set(&newsk->sk_cookie,
687 atomic64_read(&inet_rsk(req)->ir_cookie));
689 newicsk->icsk_retransmits = 0;
690 newicsk->icsk_backoff = 0;
691 newicsk->icsk_probes_out = 0;
693 /* Deinitialize accept_queue to trap illegal accesses. */
694 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
696 security_inet_csk_clone(newsk, req);
700 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
703 * At this point, there should be no process reference to this
704 * socket, and thus no user references at all. Therefore we
705 * can assume the socket waitqueue is inactive and nobody will
706 * try to jump onto it.
708 void inet_csk_destroy_sock(struct sock *sk)
710 WARN_ON(sk->sk_state != TCP_CLOSE);
711 WARN_ON(!sock_flag(sk, SOCK_DEAD));
713 /* It cannot be in hash table! */
714 WARN_ON(!sk_unhashed(sk));
716 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
717 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
719 sk->sk_prot->destroy(sk);
721 sk_stream_kill_queues(sk);
723 xfrm_sk_free_policy(sk);
725 sk_refcnt_debug_release(sk);
728 percpu_counter_dec(sk->sk_prot->orphan_count);
732 EXPORT_SYMBOL(inet_csk_destroy_sock);
734 /* This function allows to force a closure of a socket after the call to
735 * tcp/dccp_create_openreq_child().
737 void inet_csk_prepare_forced_close(struct sock *sk)
738 __releases(&sk->sk_lock.slock)
740 /* sk_clone_lock locked the socket and set refcnt to 2 */
744 /* The below has to be done to allow calling inet_csk_destroy_sock */
745 sock_set_flag(sk, SOCK_DEAD);
746 percpu_counter_inc(sk->sk_prot->orphan_count);
747 inet_sk(sk)->inet_num = 0;
749 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
751 int inet_csk_listen_start(struct sock *sk, int backlog)
753 struct inet_connection_sock *icsk = inet_csk(sk);
754 struct inet_sock *inet = inet_sk(sk);
755 int err = -EADDRINUSE;
757 reqsk_queue_alloc(&icsk->icsk_accept_queue);
759 sk->sk_max_ack_backlog = backlog;
760 sk->sk_ack_backlog = 0;
761 inet_csk_delack_init(sk);
763 /* There is race window here: we announce ourselves listening,
764 * but this transition is still not validated by get_port().
765 * It is OK, because this socket enters to hash table only
766 * after validation is complete.
768 sk_state_store(sk, TCP_LISTEN);
769 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
770 inet->inet_sport = htons(inet->inet_num);
773 err = sk->sk_prot->hash(sk);
779 sk->sk_state = TCP_CLOSE;
782 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
784 static void inet_child_forget(struct sock *sk, struct request_sock *req,
787 sk->sk_prot->disconnect(child, O_NONBLOCK);
791 percpu_counter_inc(sk->sk_prot->orphan_count);
793 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
794 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
795 BUG_ON(sk != req->rsk_listener);
797 /* Paranoid, to prevent race condition if
798 * an inbound pkt destined for child is
799 * blocked by sock lock in tcp_v4_rcv().
800 * Also to satisfy an assertion in
801 * tcp_v4_destroy_sock().
803 tcp_sk(child)->fastopen_rsk = NULL;
805 inet_csk_destroy_sock(child);
808 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
809 struct request_sock *req,
812 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
814 spin_lock(&queue->rskq_lock);
815 if (unlikely(sk->sk_state != TCP_LISTEN)) {
816 inet_child_forget(sk, req, child);
821 if (queue->rskq_accept_head == NULL)
822 queue->rskq_accept_head = req;
824 queue->rskq_accept_tail->dl_next = req;
825 queue->rskq_accept_tail = req;
826 sk_acceptq_added(sk);
828 spin_unlock(&queue->rskq_lock);
831 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
833 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
834 struct request_sock *req, bool own_req)
837 inet_csk_reqsk_queue_drop(sk, req);
838 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
839 if (inet_csk_reqsk_queue_add(sk, req, child))
842 /* Too bad, another child took ownership of the request, undo. */
843 bh_unlock_sock(child);
847 EXPORT_SYMBOL(inet_csk_complete_hashdance);
850 * This routine closes sockets which have been at least partially
851 * opened, but not yet accepted.
853 void inet_csk_listen_stop(struct sock *sk)
855 struct inet_connection_sock *icsk = inet_csk(sk);
856 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
857 struct request_sock *next, *req;
859 /* Following specs, it would be better either to send FIN
860 * (and enter FIN-WAIT-1, it is normal close)
861 * or to send active reset (abort).
862 * Certainly, it is pretty dangerous while synflood, but it is
863 * bad justification for our negligence 8)
864 * To be honest, we are not able to make either
865 * of the variants now. --ANK
867 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
868 struct sock *child = req->sk;
872 WARN_ON(sock_owned_by_user(child));
875 inet_child_forget(sk, req, child);
877 bh_unlock_sock(child);
883 if (queue->fastopenq.rskq_rst_head) {
884 /* Free all the reqs queued in rskq_rst_head. */
885 spin_lock_bh(&queue->fastopenq.lock);
886 req = queue->fastopenq.rskq_rst_head;
887 queue->fastopenq.rskq_rst_head = NULL;
888 spin_unlock_bh(&queue->fastopenq.lock);
889 while (req != NULL) {
895 WARN_ON_ONCE(sk->sk_ack_backlog);
897 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
899 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
901 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
902 const struct inet_sock *inet = inet_sk(sk);
904 sin->sin_family = AF_INET;
905 sin->sin_addr.s_addr = inet->inet_daddr;
906 sin->sin_port = inet->inet_dport;
908 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
911 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
912 char __user *optval, int __user *optlen)
914 const struct inet_connection_sock *icsk = inet_csk(sk);
916 if (icsk->icsk_af_ops->compat_getsockopt)
917 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
919 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
922 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
924 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
925 char __user *optval, unsigned int optlen)
927 const struct inet_connection_sock *icsk = inet_csk(sk);
929 if (icsk->icsk_af_ops->compat_setsockopt)
930 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
932 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
935 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
938 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
940 const struct inet_sock *inet = inet_sk(sk);
941 const struct ip_options_rcu *inet_opt;
942 __be32 daddr = inet->inet_daddr;
947 inet_opt = rcu_dereference(inet->inet_opt);
948 if (inet_opt && inet_opt->opt.srr)
949 daddr = inet_opt->opt.faddr;
951 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
952 inet->inet_saddr, inet->inet_dport,
953 inet->inet_sport, sk->sk_protocol,
954 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
958 sk_setup_caps(sk, &rt->dst);
964 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
966 struct dst_entry *dst = __sk_dst_check(sk, 0);
967 struct inet_sock *inet = inet_sk(sk);
970 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
974 dst->ops->update_pmtu(dst, sk, NULL, mtu);
976 dst = __sk_dst_check(sk, 0);
978 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
982 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);