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);
105 int remaining, rover, low, high;
108 inet_get_local_port_range(net, &low, &high);
109 remaining = (high - low) + 1;
110 smallest_rover = rover = prandom_u32() % remaining + low;
114 if (inet_is_local_reserved_port(net, rover))
116 head = &hashinfo->bhash[inet_bhashfn(net, rover,
117 hashinfo->bhash_size)];
118 spin_lock(&head->lock);
119 inet_bind_bucket_for_each(tb, &head->chain)
120 if (net_eq(ib_net(tb), net) && tb->port == rover) {
121 if (((tb->fastreuse > 0 &&
123 sk->sk_state != TCP_LISTEN) ||
124 (tb->fastreuseport > 0 &&
126 uid_eq(tb->fastuid, uid))) &&
127 (tb->num_owners < smallest_size || smallest_size == -1)) {
128 smallest_size = tb->num_owners;
129 smallest_rover = rover;
130 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 &&
131 !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
132 snum = smallest_rover;
136 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
144 spin_unlock(&head->lock);
148 } while (--remaining > 0);
150 /* Exhausted local port range during search? It is not
151 * possible for us to be holding one of the bind hash
152 * locks if this test triggers, because if 'remaining'
153 * drops to zero, we broke out of the do/while loop at
154 * the top level, not from the 'break;' statement.
157 if (remaining <= 0) {
158 if (smallest_size != -1) {
159 snum = smallest_rover;
164 /* OK, here is the one we will use. HEAD is
165 * non-NULL and we hold it's mutex.
170 head = &hashinfo->bhash[inet_bhashfn(net, snum,
171 hashinfo->bhash_size)];
172 spin_lock(&head->lock);
173 inet_bind_bucket_for_each(tb, &head->chain)
174 if (net_eq(ib_net(tb), net) && tb->port == snum)
180 if (!hlist_empty(&tb->owners)) {
181 if (sk->sk_reuse == SK_FORCE_REUSE)
184 if (((tb->fastreuse > 0 &&
185 sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
186 (tb->fastreuseport > 0 &&
187 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
188 smallest_size == -1) {
192 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
193 if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
194 (tb->fastreuseport > 0 &&
195 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
196 smallest_size != -1 && --attempts >= 0) {
197 spin_unlock(&head->lock);
207 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
208 net, head, snum)) == NULL)
210 if (hlist_empty(&tb->owners)) {
211 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
215 if (sk->sk_reuseport) {
216 tb->fastreuseport = 1;
219 tb->fastreuseport = 0;
222 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
224 if (tb->fastreuseport &&
225 (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
226 tb->fastreuseport = 0;
229 if (!inet_csk(sk)->icsk_bind_hash)
230 inet_bind_hash(sk, tb, snum);
231 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
235 spin_unlock(&head->lock);
240 EXPORT_SYMBOL_GPL(inet_csk_get_port);
243 * Wait for an incoming connection, avoid race conditions. This must be called
244 * with the socket locked.
246 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
248 struct inet_connection_sock *icsk = inet_csk(sk);
253 * True wake-one mechanism for incoming connections: only
254 * one process gets woken up, not the 'whole herd'.
255 * Since we do not 'race & poll' for established sockets
256 * anymore, the common case will execute the loop only once.
258 * Subtle issue: "add_wait_queue_exclusive()" will be added
259 * after any current non-exclusive waiters, and we know that
260 * it will always _stay_ after any new non-exclusive waiters
261 * because all non-exclusive waiters are added at the
262 * beginning of the wait-queue. As such, it's ok to "drop"
263 * our exclusiveness temporarily when we get woken up without
264 * having to remove and re-insert us on the wait queue.
267 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
270 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
271 timeo = schedule_timeout(timeo);
272 sched_annotate_sleep();
275 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
278 if (sk->sk_state != TCP_LISTEN)
280 err = sock_intr_errno(timeo);
281 if (signal_pending(current))
287 finish_wait(sk_sleep(sk), &wait);
292 * This will accept the next outstanding connection.
294 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
296 struct inet_connection_sock *icsk = inet_csk(sk);
297 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
298 struct request_sock *req;
304 /* We need to make sure that this socket is listening,
305 * and that it has something pending.
308 if (sk->sk_state != TCP_LISTEN)
311 /* Find already established connection */
312 if (reqsk_queue_empty(queue)) {
313 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
315 /* If this is a non blocking socket don't sleep */
320 error = inet_csk_wait_for_connect(sk, timeo);
324 req = reqsk_queue_remove(queue);
327 sk_acceptq_removed(sk);
328 if (sk->sk_protocol == IPPROTO_TCP &&
329 tcp_rsk(req)->tfo_listener &&
331 spin_lock_bh(&queue->fastopenq->lock);
332 if (tcp_rsk(req)->tfo_listener) {
333 /* We are still waiting for the final ACK from 3WHS
334 * so can't free req now. Instead, we set req->sk to
335 * NULL to signify that the child socket is taken
336 * so reqsk_fastopen_remove() will free the req
337 * when 3WHS finishes (or is aborted).
342 spin_unlock_bh(&queue->fastopenq->lock);
355 EXPORT_SYMBOL(inet_csk_accept);
358 * Using different timers for retransmit, delayed acks and probes
359 * We may wish use just one timer maintaining a list of expire jiffies
362 void inet_csk_init_xmit_timers(struct sock *sk,
363 void (*retransmit_handler)(unsigned long),
364 void (*delack_handler)(unsigned long),
365 void (*keepalive_handler)(unsigned long))
367 struct inet_connection_sock *icsk = inet_csk(sk);
369 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
371 setup_timer(&icsk->icsk_delack_timer, delack_handler,
373 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
374 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
376 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
378 void inet_csk_clear_xmit_timers(struct sock *sk)
380 struct inet_connection_sock *icsk = inet_csk(sk);
382 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
384 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
385 sk_stop_timer(sk, &icsk->icsk_delack_timer);
386 sk_stop_timer(sk, &sk->sk_timer);
388 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
390 void inet_csk_delete_keepalive_timer(struct sock *sk)
392 sk_stop_timer(sk, &sk->sk_timer);
394 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
396 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
398 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
400 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
402 struct dst_entry *inet_csk_route_req(struct sock *sk,
404 const struct request_sock *req)
406 const struct inet_request_sock *ireq = inet_rsk(req);
407 struct net *net = read_pnet(&ireq->ireq_net);
408 struct ip_options_rcu *opt = ireq->opt;
411 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
412 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
413 sk->sk_protocol, inet_sk_flowi_flags(sk),
414 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
415 ireq->ir_loc_addr, ireq->ir_rmt_port,
416 htons(ireq->ir_num));
417 security_req_classify_flow(req, flowi4_to_flowi(fl4));
418 rt = ip_route_output_flow(net, fl4, sk);
421 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
428 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
431 EXPORT_SYMBOL_GPL(inet_csk_route_req);
433 struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
435 const struct request_sock *req)
437 const struct inet_request_sock *ireq = inet_rsk(req);
438 struct net *net = read_pnet(&ireq->ireq_net);
439 struct inet_sock *newinet = inet_sk(newsk);
440 struct ip_options_rcu *opt;
444 fl4 = &newinet->cork.fl.u.ip4;
447 opt = rcu_dereference(newinet->inet_opt);
448 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
449 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
450 sk->sk_protocol, inet_sk_flowi_flags(sk),
451 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
452 ireq->ir_loc_addr, ireq->ir_rmt_port,
453 htons(ireq->ir_num));
454 security_req_classify_flow(req, flowi4_to_flowi(fl4));
455 rt = ip_route_output_flow(net, fl4, sk);
458 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
467 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
470 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
472 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
473 const u32 rnd, const u32 synq_hsize)
475 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
478 #if IS_ENABLED(CONFIG_IPV6)
479 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
481 #define AF_INET_FAMILY(fam) true
484 /* Note: this is temporary :
485 * req sock will no longer be in listener hash table
487 struct request_sock *inet_csk_search_req(struct sock *sk,
492 struct inet_connection_sock *icsk = inet_csk(sk);
493 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
494 struct request_sock *req;
495 u32 hash = inet_synq_hash(raddr, rport, lopt->hash_rnd,
496 lopt->nr_table_entries);
498 spin_lock(&icsk->icsk_accept_queue.syn_wait_lock);
499 for (req = lopt->syn_table[hash]; req != NULL; req = req->dl_next) {
500 const struct inet_request_sock *ireq = inet_rsk(req);
502 if (ireq->ir_rmt_port == rport &&
503 ireq->ir_rmt_addr == raddr &&
504 ireq->ir_loc_addr == laddr &&
505 AF_INET_FAMILY(req->rsk_ops->family)) {
506 atomic_inc(&req->rsk_refcnt);
511 spin_unlock(&icsk->icsk_accept_queue.syn_wait_lock);
515 EXPORT_SYMBOL_GPL(inet_csk_search_req);
517 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
518 unsigned long timeout)
520 struct inet_connection_sock *icsk = inet_csk(sk);
521 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
522 const u32 h = inet_synq_hash(inet_rsk(req)->ir_rmt_addr,
523 inet_rsk(req)->ir_rmt_port,
524 lopt->hash_rnd, lopt->nr_table_entries);
526 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
527 inet_csk_reqsk_queue_added(sk, timeout);
529 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
531 /* Only thing we need from tcp.h */
532 extern int sysctl_tcp_synack_retries;
535 /* Decide when to expire the request and when to resend SYN-ACK */
536 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
537 const int max_retries,
538 const u8 rskq_defer_accept,
539 int *expire, int *resend)
541 if (!rskq_defer_accept) {
542 *expire = req->num_timeout >= thresh;
546 *expire = req->num_timeout >= thresh &&
547 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
549 * Do not resend while waiting for data after ACK,
550 * start to resend on end of deferring period to give
551 * last chance for data or ACK to create established socket.
553 *resend = !inet_rsk(req)->acked ||
554 req->num_timeout >= rskq_defer_accept - 1;
557 int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req)
559 int err = req->rsk_ops->rtx_syn_ack(parent, req);
565 EXPORT_SYMBOL(inet_rtx_syn_ack);
567 /* return true if req was found in the syn_table[] */
568 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
569 struct request_sock *req)
571 struct listen_sock *lopt = queue->listen_opt;
572 struct request_sock **prev;
575 spin_lock(&queue->syn_wait_lock);
577 for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
578 prev = &(*prev)->dl_next) {
580 *prev = req->dl_next;
586 spin_unlock(&queue->syn_wait_lock);
587 if (del_timer(&req->rsk_timer))
592 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
594 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
595 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
599 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
601 static void reqsk_timer_handler(unsigned long data)
603 struct request_sock *req = (struct request_sock *)data;
604 struct sock *sk_listener = req->rsk_listener;
605 struct inet_connection_sock *icsk = inet_csk(sk_listener);
606 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
607 struct listen_sock *lopt = queue->listen_opt;
608 int qlen, expire = 0, resend = 0;
609 int max_retries, thresh;
612 if (sk_listener->sk_state != TCP_LISTEN || !lopt) {
617 max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
618 thresh = max_retries;
619 /* Normally all the openreqs are young and become mature
620 * (i.e. converted to established socket) for first timeout.
621 * If synack was not acknowledged for 1 second, it means
622 * one of the following things: synack was lost, ack was lost,
623 * rtt is high or nobody planned to ack (i.e. synflood).
624 * When server is a bit loaded, queue is populated with old
625 * open requests, reducing effective size of queue.
626 * When server is well loaded, queue size reduces to zero
627 * after several minutes of work. It is not synflood,
628 * it is normal operation. The solution is pruning
629 * too old entries overriding normal timeout, when
630 * situation becomes dangerous.
632 * Essentially, we reserve half of room for young
633 * embrions; and abort old ones without pity, if old
634 * ones are about to clog our table.
636 qlen = listen_sock_qlen(lopt);
637 if (qlen >> (lopt->max_qlen_log - 1)) {
638 int young = listen_sock_young(lopt) << 1;
647 defer_accept = READ_ONCE(queue->rskq_defer_accept);
649 max_retries = defer_accept;
650 syn_ack_recalc(req, thresh, max_retries, defer_accept,
652 req->rsk_ops->syn_ack_timeout(req);
655 !inet_rtx_syn_ack(sk_listener, req) ||
656 inet_rsk(req)->acked)) {
659 if (req->num_timeout++ == 0)
660 atomic_inc(&lopt->young_dec);
661 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
662 mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
665 inet_csk_reqsk_queue_drop(sk_listener, req);
669 void reqsk_queue_hash_req(struct request_sock_queue *queue,
670 u32 hash, struct request_sock *req,
671 unsigned long timeout)
673 struct listen_sock *lopt = queue->listen_opt;
675 req->num_retrans = 0;
676 req->num_timeout = 0;
679 /* before letting lookups find us, make sure all req fields
680 * are committed to memory and refcnt initialized.
683 atomic_set(&req->rsk_refcnt, 2);
684 setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
685 req->rsk_hash = hash;
687 spin_lock(&queue->syn_wait_lock);
688 req->dl_next = lopt->syn_table[hash];
689 lopt->syn_table[hash] = req;
690 spin_unlock(&queue->syn_wait_lock);
692 mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
694 EXPORT_SYMBOL(reqsk_queue_hash_req);
697 * inet_csk_clone_lock - clone an inet socket, and lock its clone
698 * @sk: the socket to clone
700 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
702 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
704 struct sock *inet_csk_clone_lock(const struct sock *sk,
705 const struct request_sock *req,
706 const gfp_t priority)
708 struct sock *newsk = sk_clone_lock(sk, priority);
711 struct inet_connection_sock *newicsk = inet_csk(newsk);
713 newsk->sk_state = TCP_SYN_RECV;
714 newicsk->icsk_bind_hash = NULL;
716 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
717 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
718 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
719 newsk->sk_write_space = sk_stream_write_space;
721 newsk->sk_mark = inet_rsk(req)->ir_mark;
722 atomic64_set(&newsk->sk_cookie,
723 atomic64_read(&inet_rsk(req)->ir_cookie));
725 newicsk->icsk_retransmits = 0;
726 newicsk->icsk_backoff = 0;
727 newicsk->icsk_probes_out = 0;
729 /* Deinitialize accept_queue to trap illegal accesses. */
730 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
732 security_inet_csk_clone(newsk, req);
736 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
739 * At this point, there should be no process reference to this
740 * socket, and thus no user references at all. Therefore we
741 * can assume the socket waitqueue is inactive and nobody will
742 * try to jump onto it.
744 void inet_csk_destroy_sock(struct sock *sk)
746 WARN_ON(sk->sk_state != TCP_CLOSE);
747 WARN_ON(!sock_flag(sk, SOCK_DEAD));
749 /* It cannot be in hash table! */
750 WARN_ON(!sk_unhashed(sk));
752 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
753 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
755 sk->sk_prot->destroy(sk);
757 sk_stream_kill_queues(sk);
759 xfrm_sk_free_policy(sk);
761 sk_refcnt_debug_release(sk);
763 percpu_counter_dec(sk->sk_prot->orphan_count);
766 EXPORT_SYMBOL(inet_csk_destroy_sock);
768 /* This function allows to force a closure of a socket after the call to
769 * tcp/dccp_create_openreq_child().
771 void inet_csk_prepare_forced_close(struct sock *sk)
772 __releases(&sk->sk_lock.slock)
774 /* sk_clone_lock locked the socket and set refcnt to 2 */
778 /* The below has to be done to allow calling inet_csk_destroy_sock */
779 sock_set_flag(sk, SOCK_DEAD);
780 percpu_counter_inc(sk->sk_prot->orphan_count);
781 inet_sk(sk)->inet_num = 0;
783 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
785 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
787 struct inet_sock *inet = inet_sk(sk);
788 struct inet_connection_sock *icsk = inet_csk(sk);
789 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
794 sk->sk_max_ack_backlog = 0;
795 sk->sk_ack_backlog = 0;
796 inet_csk_delack_init(sk);
798 /* There is race window here: we announce ourselves listening,
799 * but this transition is still not validated by get_port().
800 * It is OK, because this socket enters to hash table only
801 * after validation is complete.
803 sk->sk_state = TCP_LISTEN;
804 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
805 inet->inet_sport = htons(inet->inet_num);
808 sk->sk_prot->hash(sk);
813 sk->sk_state = TCP_CLOSE;
814 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
817 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
820 * This routine closes sockets which have been at least partially
821 * opened, but not yet accepted.
823 void inet_csk_listen_stop(struct sock *sk)
825 struct inet_connection_sock *icsk = inet_csk(sk);
826 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
827 struct request_sock *acc_req;
828 struct request_sock *req;
830 /* make all the listen_opt local to us */
831 acc_req = reqsk_queue_yank_acceptq(queue);
833 /* Following specs, it would be better either to send FIN
834 * (and enter FIN-WAIT-1, it is normal close)
835 * or to send active reset (abort).
836 * Certainly, it is pretty dangerous while synflood, but it is
837 * bad justification for our negligence 8)
838 * To be honest, we are not able to make either
839 * of the variants now. --ANK
841 reqsk_queue_destroy(queue);
843 while ((req = acc_req) != NULL) {
844 struct sock *child = req->sk;
846 acc_req = req->dl_next;
850 WARN_ON(sock_owned_by_user(child));
853 sk->sk_prot->disconnect(child, O_NONBLOCK);
857 percpu_counter_inc(sk->sk_prot->orphan_count);
859 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
860 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
861 BUG_ON(sk != req->rsk_listener);
863 /* Paranoid, to prevent race condition if
864 * an inbound pkt destined for child is
865 * blocked by sock lock in tcp_v4_rcv().
866 * Also to satisfy an assertion in
867 * tcp_v4_destroy_sock().
869 tcp_sk(child)->fastopen_rsk = NULL;
871 inet_csk_destroy_sock(child);
873 bh_unlock_sock(child);
877 sk_acceptq_removed(sk);
880 if (queue->fastopenq) {
881 /* Free all the reqs queued in rskq_rst_head. */
882 spin_lock_bh(&queue->fastopenq->lock);
883 acc_req = queue->fastopenq->rskq_rst_head;
884 queue->fastopenq->rskq_rst_head = NULL;
885 spin_unlock_bh(&queue->fastopenq->lock);
886 while ((req = acc_req) != NULL) {
887 acc_req = req->dl_next;
891 WARN_ON(sk->sk_ack_backlog);
893 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
895 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
897 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
898 const struct inet_sock *inet = inet_sk(sk);
900 sin->sin_family = AF_INET;
901 sin->sin_addr.s_addr = inet->inet_daddr;
902 sin->sin_port = inet->inet_dport;
904 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
907 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
908 char __user *optval, int __user *optlen)
910 const struct inet_connection_sock *icsk = inet_csk(sk);
912 if (icsk->icsk_af_ops->compat_getsockopt)
913 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
915 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
918 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
920 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
921 char __user *optval, unsigned int optlen)
923 const struct inet_connection_sock *icsk = inet_csk(sk);
925 if (icsk->icsk_af_ops->compat_setsockopt)
926 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
928 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
931 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
934 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
936 const struct inet_sock *inet = inet_sk(sk);
937 const struct ip_options_rcu *inet_opt;
938 __be32 daddr = inet->inet_daddr;
943 inet_opt = rcu_dereference(inet->inet_opt);
944 if (inet_opt && inet_opt->opt.srr)
945 daddr = inet_opt->opt.faddr;
947 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
948 inet->inet_saddr, inet->inet_dport,
949 inet->inet_sport, sk->sk_protocol,
950 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
954 sk_setup_caps(sk, &rt->dst);
960 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
962 struct dst_entry *dst = __sk_dst_check(sk, 0);
963 struct inet_sock *inet = inet_sk(sk);
966 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
970 dst->ops->update_pmtu(dst, sk, NULL, mtu);
972 dst = __sk_dst_check(sk, 0);
974 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
978 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);