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 /* Obtain a reference to a local port for the given sock,
91 * if snum is zero it means select any available local port.
93 int inet_csk_get_port(struct sock *sk, unsigned short snum)
95 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
96 struct inet_bind_hashbucket *head;
97 struct inet_bind_bucket *tb;
98 int ret, attempts = 5;
99 struct net *net = sock_net(sk);
100 int smallest_size = -1, smallest_rover;
101 kuid_t uid = sock_i_uid(sk);
102 int attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
106 int remaining, rover, low, high;
109 inet_get_local_port_range(net, &low, &high);
111 int half = low + ((high - low) >> 1);
113 if (attempt_half == 1)
118 remaining = (high - low) + 1;
119 smallest_rover = rover = prandom_u32() % remaining + low;
123 if (inet_is_local_reserved_port(net, rover))
125 head = &hashinfo->bhash[inet_bhashfn(net, rover,
126 hashinfo->bhash_size)];
127 spin_lock(&head->lock);
128 inet_bind_bucket_for_each(tb, &head->chain)
129 if (net_eq(ib_net(tb), net) && tb->port == rover) {
130 if (((tb->fastreuse > 0 &&
132 sk->sk_state != TCP_LISTEN) ||
133 (tb->fastreuseport > 0 &&
135 uid_eq(tb->fastuid, uid))) &&
136 (tb->num_owners < smallest_size || smallest_size == -1)) {
137 smallest_size = tb->num_owners;
138 smallest_rover = rover;
140 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
148 spin_unlock(&head->lock);
152 } while (--remaining > 0);
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.
161 if (remaining <= 0) {
162 if (smallest_size != -1) {
163 snum = smallest_rover;
166 if (attempt_half == 1) {
167 /* OK we now try the upper half of the range */
173 /* OK, here is the one we will use. HEAD is
174 * non-NULL and we hold it's mutex.
179 head = &hashinfo->bhash[inet_bhashfn(net, snum,
180 hashinfo->bhash_size)];
181 spin_lock(&head->lock);
182 inet_bind_bucket_for_each(tb, &head->chain)
183 if (net_eq(ib_net(tb), net) && tb->port == snum)
189 if (!hlist_empty(&tb->owners)) {
190 if (sk->sk_reuse == SK_FORCE_REUSE)
193 if (((tb->fastreuse > 0 &&
194 sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
195 (tb->fastreuseport > 0 &&
196 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
197 smallest_size == -1) {
201 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
202 if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
203 (tb->fastreuseport > 0 &&
204 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
205 smallest_size != -1 && --attempts >= 0) {
206 spin_unlock(&head->lock);
216 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
217 net, head, snum)) == NULL)
219 if (hlist_empty(&tb->owners)) {
220 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
224 if (sk->sk_reuseport) {
225 tb->fastreuseport = 1;
228 tb->fastreuseport = 0;
231 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
233 if (tb->fastreuseport &&
234 (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
235 tb->fastreuseport = 0;
238 if (!inet_csk(sk)->icsk_bind_hash)
239 inet_bind_hash(sk, tb, snum);
240 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
244 spin_unlock(&head->lock);
249 EXPORT_SYMBOL_GPL(inet_csk_get_port);
252 * Wait for an incoming connection, avoid race conditions. This must be called
253 * with the socket locked.
255 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
257 struct inet_connection_sock *icsk = inet_csk(sk);
262 * True wake-one mechanism for incoming connections: only
263 * one process gets woken up, not the 'whole herd'.
264 * Since we do not 'race & poll' for established sockets
265 * anymore, the common case will execute the loop only once.
267 * Subtle issue: "add_wait_queue_exclusive()" will be added
268 * after any current non-exclusive waiters, and we know that
269 * it will always _stay_ after any new non-exclusive waiters
270 * because all non-exclusive waiters are added at the
271 * beginning of the wait-queue. As such, it's ok to "drop"
272 * our exclusiveness temporarily when we get woken up without
273 * having to remove and re-insert us on the wait queue.
276 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
279 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
280 timeo = schedule_timeout(timeo);
281 sched_annotate_sleep();
284 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
287 if (sk->sk_state != TCP_LISTEN)
289 err = sock_intr_errno(timeo);
290 if (signal_pending(current))
296 finish_wait(sk_sleep(sk), &wait);
301 * This will accept the next outstanding connection.
303 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
305 struct inet_connection_sock *icsk = inet_csk(sk);
306 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
307 struct request_sock *req;
313 /* We need to make sure that this socket is listening,
314 * and that it has something pending.
317 if (sk->sk_state != TCP_LISTEN)
320 /* Find already established connection */
321 if (reqsk_queue_empty(queue)) {
322 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
324 /* If this is a non blocking socket don't sleep */
329 error = inet_csk_wait_for_connect(sk, timeo);
333 req = reqsk_queue_remove(queue, sk);
336 if (sk->sk_protocol == IPPROTO_TCP &&
337 tcp_rsk(req)->tfo_listener) {
338 spin_lock_bh(&queue->fastopenq.lock);
339 if (tcp_rsk(req)->tfo_listener) {
340 /* We are still waiting for the final ACK from 3WHS
341 * so can't free req now. Instead, we set req->sk to
342 * NULL to signify that the child socket is taken
343 * so reqsk_fastopen_remove() will free the req
344 * when 3WHS finishes (or is aborted).
349 spin_unlock_bh(&queue->fastopenq.lock);
362 EXPORT_SYMBOL(inet_csk_accept);
365 * Using different timers for retransmit, delayed acks and probes
366 * We may wish use just one timer maintaining a list of expire jiffies
369 void inet_csk_init_xmit_timers(struct sock *sk,
370 void (*retransmit_handler)(unsigned long),
371 void (*delack_handler)(unsigned long),
372 void (*keepalive_handler)(unsigned long))
374 struct inet_connection_sock *icsk = inet_csk(sk);
376 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
378 setup_timer(&icsk->icsk_delack_timer, delack_handler,
380 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
381 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
383 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
385 void inet_csk_clear_xmit_timers(struct sock *sk)
387 struct inet_connection_sock *icsk = inet_csk(sk);
389 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
391 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
392 sk_stop_timer(sk, &icsk->icsk_delack_timer);
393 sk_stop_timer(sk, &sk->sk_timer);
395 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
397 void inet_csk_delete_keepalive_timer(struct sock *sk)
399 sk_stop_timer(sk, &sk->sk_timer);
401 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
403 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
405 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
407 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
409 struct dst_entry *inet_csk_route_req(const struct sock *sk,
411 const struct request_sock *req)
413 const struct inet_request_sock *ireq = inet_rsk(req);
414 struct net *net = read_pnet(&ireq->ireq_net);
415 struct ip_options_rcu *opt = ireq->opt;
418 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
419 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
420 sk->sk_protocol, inet_sk_flowi_flags(sk),
421 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
422 ireq->ir_loc_addr, ireq->ir_rmt_port,
423 htons(ireq->ir_num));
424 security_req_classify_flow(req, flowi4_to_flowi(fl4));
425 rt = ip_route_output_flow(net, fl4, sk);
428 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
435 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
438 EXPORT_SYMBOL_GPL(inet_csk_route_req);
440 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
442 const struct request_sock *req)
444 const struct inet_request_sock *ireq = inet_rsk(req);
445 struct net *net = read_pnet(&ireq->ireq_net);
446 struct inet_sock *newinet = inet_sk(newsk);
447 struct ip_options_rcu *opt;
451 fl4 = &newinet->cork.fl.u.ip4;
454 opt = rcu_dereference(newinet->inet_opt);
455 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
456 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
457 sk->sk_protocol, inet_sk_flowi_flags(sk),
458 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
459 ireq->ir_loc_addr, ireq->ir_rmt_port,
460 htons(ireq->ir_num));
461 security_req_classify_flow(req, flowi4_to_flowi(fl4));
462 rt = ip_route_output_flow(net, fl4, sk);
465 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
474 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
477 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
479 #if IS_ENABLED(CONFIG_IPV6)
480 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
482 #define AF_INET_FAMILY(fam) true
485 /* Only thing we need from tcp.h */
486 extern int sysctl_tcp_synack_retries;
489 /* Decide when to expire the request and when to resend SYN-ACK */
490 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
491 const int max_retries,
492 const u8 rskq_defer_accept,
493 int *expire, int *resend)
495 if (!rskq_defer_accept) {
496 *expire = req->num_timeout >= thresh;
500 *expire = req->num_timeout >= thresh &&
501 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
503 * Do not resend while waiting for data after ACK,
504 * start to resend on end of deferring period to give
505 * last chance for data or ACK to create established socket.
507 *resend = !inet_rsk(req)->acked ||
508 req->num_timeout >= rskq_defer_accept - 1;
511 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
513 int err = req->rsk_ops->rtx_syn_ack(parent, req);
519 EXPORT_SYMBOL(inet_rtx_syn_ack);
521 /* return true if req was found in the ehash table */
522 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
523 struct request_sock *req)
525 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
528 if (sk_hashed(req_to_sk(req))) {
529 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
532 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
535 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
540 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
542 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
543 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
547 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
549 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
551 inet_csk_reqsk_queue_drop(sk, req);
554 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
556 static void reqsk_timer_handler(unsigned long data)
558 struct request_sock *req = (struct request_sock *)data;
559 struct sock *sk_listener = req->rsk_listener;
560 struct inet_connection_sock *icsk = inet_csk(sk_listener);
561 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
562 int qlen, expire = 0, resend = 0;
563 int max_retries, thresh;
566 if (sk_state_load(sk_listener) != TCP_LISTEN)
569 max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
570 thresh = max_retries;
571 /* Normally all the openreqs are young and become mature
572 * (i.e. converted to established socket) for first timeout.
573 * If synack was not acknowledged for 1 second, it means
574 * one of the following things: synack was lost, ack was lost,
575 * rtt is high or nobody planned to ack (i.e. synflood).
576 * When server is a bit loaded, queue is populated with old
577 * open requests, reducing effective size of queue.
578 * When server is well loaded, queue size reduces to zero
579 * after several minutes of work. It is not synflood,
580 * it is normal operation. The solution is pruning
581 * too old entries overriding normal timeout, when
582 * situation becomes dangerous.
584 * Essentially, we reserve half of room for young
585 * embrions; and abort old ones without pity, if old
586 * ones are about to clog our table.
588 qlen = reqsk_queue_len(queue);
589 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
590 int young = reqsk_queue_len_young(queue) << 1;
599 defer_accept = READ_ONCE(queue->rskq_defer_accept);
601 max_retries = defer_accept;
602 syn_ack_recalc(req, thresh, max_retries, defer_accept,
604 req->rsk_ops->syn_ack_timeout(req);
607 !inet_rtx_syn_ack(sk_listener, req) ||
608 inet_rsk(req)->acked)) {
611 if (req->num_timeout++ == 0)
612 atomic_dec(&queue->young);
613 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
614 mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
618 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
621 static void reqsk_queue_hash_req(struct request_sock *req,
622 unsigned long timeout)
624 req->num_retrans = 0;
625 req->num_timeout = 0;
628 setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
629 mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
631 inet_ehash_insert(req_to_sk(req), NULL);
632 /* before letting lookups find us, make sure all req fields
633 * are committed to memory and refcnt initialized.
636 atomic_set(&req->rsk_refcnt, 2 + 1);
639 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
640 unsigned long timeout)
642 reqsk_queue_hash_req(req, timeout);
643 inet_csk_reqsk_queue_added(sk);
645 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
648 * inet_csk_clone_lock - clone an inet socket, and lock its clone
649 * @sk: the socket to clone
651 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
653 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
655 struct sock *inet_csk_clone_lock(const struct sock *sk,
656 const struct request_sock *req,
657 const gfp_t priority)
659 struct sock *newsk = sk_clone_lock(sk, priority);
662 struct inet_connection_sock *newicsk = inet_csk(newsk);
664 newsk->sk_state = TCP_SYN_RECV;
665 newicsk->icsk_bind_hash = NULL;
667 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
668 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
669 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
670 newsk->sk_write_space = sk_stream_write_space;
672 newsk->sk_mark = inet_rsk(req)->ir_mark;
673 atomic64_set(&newsk->sk_cookie,
674 atomic64_read(&inet_rsk(req)->ir_cookie));
676 newicsk->icsk_retransmits = 0;
677 newicsk->icsk_backoff = 0;
678 newicsk->icsk_probes_out = 0;
680 /* Deinitialize accept_queue to trap illegal accesses. */
681 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
683 security_inet_csk_clone(newsk, req);
687 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
690 * At this point, there should be no process reference to this
691 * socket, and thus no user references at all. Therefore we
692 * can assume the socket waitqueue is inactive and nobody will
693 * try to jump onto it.
695 void inet_csk_destroy_sock(struct sock *sk)
697 WARN_ON(sk->sk_state != TCP_CLOSE);
698 WARN_ON(!sock_flag(sk, SOCK_DEAD));
700 /* It cannot be in hash table! */
701 WARN_ON(!sk_unhashed(sk));
703 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
704 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
706 sk->sk_prot->destroy(sk);
708 sk_stream_kill_queues(sk);
710 xfrm_sk_free_policy(sk);
712 sk_refcnt_debug_release(sk);
714 percpu_counter_dec(sk->sk_prot->orphan_count);
717 EXPORT_SYMBOL(inet_csk_destroy_sock);
719 /* This function allows to force a closure of a socket after the call to
720 * tcp/dccp_create_openreq_child().
722 void inet_csk_prepare_forced_close(struct sock *sk)
723 __releases(&sk->sk_lock.slock)
725 /* sk_clone_lock locked the socket and set refcnt to 2 */
729 /* The below has to be done to allow calling inet_csk_destroy_sock */
730 sock_set_flag(sk, SOCK_DEAD);
731 percpu_counter_inc(sk->sk_prot->orphan_count);
732 inet_sk(sk)->inet_num = 0;
734 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
736 int inet_csk_listen_start(struct sock *sk, int backlog)
738 struct inet_connection_sock *icsk = inet_csk(sk);
739 struct inet_sock *inet = inet_sk(sk);
741 reqsk_queue_alloc(&icsk->icsk_accept_queue);
743 sk->sk_max_ack_backlog = backlog;
744 sk->sk_ack_backlog = 0;
745 inet_csk_delack_init(sk);
747 /* There is race window here: we announce ourselves listening,
748 * but this transition is still not validated by get_port().
749 * It is OK, because this socket enters to hash table only
750 * after validation is complete.
752 sk_state_store(sk, TCP_LISTEN);
753 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
754 inet->inet_sport = htons(inet->inet_num);
757 sk->sk_prot->hash(sk);
762 sk->sk_state = TCP_CLOSE;
765 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
767 static void inet_child_forget(struct sock *sk, struct request_sock *req,
770 sk->sk_prot->disconnect(child, O_NONBLOCK);
774 percpu_counter_inc(sk->sk_prot->orphan_count);
776 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
777 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
778 BUG_ON(sk != req->rsk_listener);
780 /* Paranoid, to prevent race condition if
781 * an inbound pkt destined for child is
782 * blocked by sock lock in tcp_v4_rcv().
783 * Also to satisfy an assertion in
784 * tcp_v4_destroy_sock().
786 tcp_sk(child)->fastopen_rsk = NULL;
788 inet_csk_destroy_sock(child);
792 void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,
795 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
797 spin_lock(&queue->rskq_lock);
798 if (unlikely(sk->sk_state != TCP_LISTEN)) {
799 inet_child_forget(sk, req, child);
803 if (queue->rskq_accept_head == NULL)
804 queue->rskq_accept_head = req;
806 queue->rskq_accept_tail->dl_next = req;
807 queue->rskq_accept_tail = req;
808 sk_acceptq_added(sk);
810 spin_unlock(&queue->rskq_lock);
812 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
814 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
815 struct request_sock *req, bool own_req)
818 inet_csk_reqsk_queue_drop(sk, req);
819 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
820 inet_csk_reqsk_queue_add(sk, req, child);
821 /* Warning: caller must not call reqsk_put(req);
822 * child stole last reference on it.
826 /* Too bad, another child took ownership of the request, undo. */
827 bh_unlock_sock(child);
831 EXPORT_SYMBOL(inet_csk_complete_hashdance);
834 * This routine closes sockets which have been at least partially
835 * opened, but not yet accepted.
837 void inet_csk_listen_stop(struct sock *sk)
839 struct inet_connection_sock *icsk = inet_csk(sk);
840 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
841 struct request_sock *next, *req;
843 /* Following specs, it would be better either to send FIN
844 * (and enter FIN-WAIT-1, it is normal close)
845 * or to send active reset (abort).
846 * Certainly, it is pretty dangerous while synflood, but it is
847 * bad justification for our negligence 8)
848 * To be honest, we are not able to make either
849 * of the variants now. --ANK
851 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
852 struct sock *child = req->sk;
856 WARN_ON(sock_owned_by_user(child));
859 inet_child_forget(sk, req, child);
860 bh_unlock_sock(child);
866 if (queue->fastopenq.rskq_rst_head) {
867 /* Free all the reqs queued in rskq_rst_head. */
868 spin_lock_bh(&queue->fastopenq.lock);
869 req = queue->fastopenq.rskq_rst_head;
870 queue->fastopenq.rskq_rst_head = NULL;
871 spin_unlock_bh(&queue->fastopenq.lock);
872 while (req != NULL) {
878 WARN_ON_ONCE(sk->sk_ack_backlog);
880 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
882 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
884 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
885 const struct inet_sock *inet = inet_sk(sk);
887 sin->sin_family = AF_INET;
888 sin->sin_addr.s_addr = inet->inet_daddr;
889 sin->sin_port = inet->inet_dport;
891 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
894 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
895 char __user *optval, int __user *optlen)
897 const struct inet_connection_sock *icsk = inet_csk(sk);
899 if (icsk->icsk_af_ops->compat_getsockopt)
900 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
902 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
905 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
907 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
908 char __user *optval, unsigned int optlen)
910 const struct inet_connection_sock *icsk = inet_csk(sk);
912 if (icsk->icsk_af_ops->compat_setsockopt)
913 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
915 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
918 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
921 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
923 const struct inet_sock *inet = inet_sk(sk);
924 const struct ip_options_rcu *inet_opt;
925 __be32 daddr = inet->inet_daddr;
930 inet_opt = rcu_dereference(inet->inet_opt);
931 if (inet_opt && inet_opt->opt.srr)
932 daddr = inet_opt->opt.faddr;
934 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
935 inet->inet_saddr, inet->inet_dport,
936 inet->inet_sport, sk->sk_protocol,
937 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
941 sk_setup_caps(sk, &rt->dst);
947 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
949 struct dst_entry *dst = __sk_dst_check(sk, 0);
950 struct inet_sock *inet = inet_sk(sk);
953 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
957 dst->ops->update_pmtu(dst, sk, NULL, mtu);
959 dst = __sk_dst_check(sk, 0);
961 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
965 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);