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);
336 sk_acceptq_removed(sk);
337 if (sk->sk_protocol == IPPROTO_TCP &&
338 tcp_rsk(req)->tfo_listener) {
339 spin_lock_bh(&queue->fastopenq.lock);
340 if (tcp_rsk(req)->tfo_listener) {
341 /* We are still waiting for the final ACK from 3WHS
342 * so can't free req now. Instead, we set req->sk to
343 * NULL to signify that the child socket is taken
344 * so reqsk_fastopen_remove() will free the req
345 * when 3WHS finishes (or is aborted).
350 spin_unlock_bh(&queue->fastopenq.lock);
363 EXPORT_SYMBOL(inet_csk_accept);
366 * Using different timers for retransmit, delayed acks and probes
367 * We may wish use just one timer maintaining a list of expire jiffies
370 void inet_csk_init_xmit_timers(struct sock *sk,
371 void (*retransmit_handler)(unsigned long),
372 void (*delack_handler)(unsigned long),
373 void (*keepalive_handler)(unsigned long))
375 struct inet_connection_sock *icsk = inet_csk(sk);
377 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
379 setup_timer(&icsk->icsk_delack_timer, delack_handler,
381 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
382 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
384 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
386 void inet_csk_clear_xmit_timers(struct sock *sk)
388 struct inet_connection_sock *icsk = inet_csk(sk);
390 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
392 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
393 sk_stop_timer(sk, &icsk->icsk_delack_timer);
394 sk_stop_timer(sk, &sk->sk_timer);
396 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
398 void inet_csk_delete_keepalive_timer(struct sock *sk)
400 sk_stop_timer(sk, &sk->sk_timer);
402 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
404 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
406 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
408 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
410 struct dst_entry *inet_csk_route_req(const struct sock *sk,
412 const struct request_sock *req)
414 const struct inet_request_sock *ireq = inet_rsk(req);
415 struct net *net = read_pnet(&ireq->ireq_net);
416 struct ip_options_rcu *opt = ireq->opt;
419 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
420 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
421 sk->sk_protocol, inet_sk_flowi_flags(sk),
422 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
423 ireq->ir_loc_addr, ireq->ir_rmt_port,
424 htons(ireq->ir_num));
425 security_req_classify_flow(req, flowi4_to_flowi(fl4));
426 rt = ip_route_output_flow(net, fl4, sk);
429 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
436 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
439 EXPORT_SYMBOL_GPL(inet_csk_route_req);
441 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
443 const struct request_sock *req)
445 const struct inet_request_sock *ireq = inet_rsk(req);
446 struct net *net = read_pnet(&ireq->ireq_net);
447 struct inet_sock *newinet = inet_sk(newsk);
448 struct ip_options_rcu *opt;
452 fl4 = &newinet->cork.fl.u.ip4;
455 opt = rcu_dereference(newinet->inet_opt);
456 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
457 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
458 sk->sk_protocol, inet_sk_flowi_flags(sk),
459 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
460 ireq->ir_loc_addr, ireq->ir_rmt_port,
461 htons(ireq->ir_num));
462 security_req_classify_flow(req, flowi4_to_flowi(fl4));
463 rt = ip_route_output_flow(net, fl4, sk);
466 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
475 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
478 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
480 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
481 const u32 rnd, const u32 synq_hsize)
483 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
486 #if IS_ENABLED(CONFIG_IPV6)
487 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
489 #define AF_INET_FAMILY(fam) true
492 /* Note: this is temporary :
493 * req sock will no longer be in listener hash table
495 struct request_sock *inet_csk_search_req(struct sock *sk,
500 struct inet_connection_sock *icsk = inet_csk(sk);
501 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
502 struct request_sock *req;
503 u32 hash = inet_synq_hash(raddr, rport, lopt->hash_rnd,
504 lopt->nr_table_entries);
506 spin_lock(&icsk->icsk_accept_queue.syn_wait_lock);
507 for (req = lopt->syn_table[hash]; req != NULL; req = req->dl_next) {
508 const struct inet_request_sock *ireq = inet_rsk(req);
510 if (ireq->ir_rmt_port == rport &&
511 ireq->ir_rmt_addr == raddr &&
512 ireq->ir_loc_addr == laddr &&
513 AF_INET_FAMILY(req->rsk_ops->family)) {
514 atomic_inc(&req->rsk_refcnt);
519 spin_unlock(&icsk->icsk_accept_queue.syn_wait_lock);
523 EXPORT_SYMBOL_GPL(inet_csk_search_req);
525 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
526 unsigned long timeout)
528 struct inet_connection_sock *icsk = inet_csk(sk);
529 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
530 const u32 h = inet_synq_hash(inet_rsk(req)->ir_rmt_addr,
531 inet_rsk(req)->ir_rmt_port,
532 lopt->hash_rnd, lopt->nr_table_entries);
534 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
535 inet_csk_reqsk_queue_added(sk, timeout);
537 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
539 /* Only thing we need from tcp.h */
540 extern int sysctl_tcp_synack_retries;
543 /* Decide when to expire the request and when to resend SYN-ACK */
544 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
545 const int max_retries,
546 const u8 rskq_defer_accept,
547 int *expire, int *resend)
549 if (!rskq_defer_accept) {
550 *expire = req->num_timeout >= thresh;
554 *expire = req->num_timeout >= thresh &&
555 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
557 * Do not resend while waiting for data after ACK,
558 * start to resend on end of deferring period to give
559 * last chance for data or ACK to create established socket.
561 *resend = !inet_rsk(req)->acked ||
562 req->num_timeout >= rskq_defer_accept - 1;
565 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
567 int err = req->rsk_ops->rtx_syn_ack(parent, req);
573 EXPORT_SYMBOL(inet_rtx_syn_ack);
575 /* return true if req was found in the syn_table[] */
576 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
577 struct request_sock *req)
579 struct listen_sock *lopt = queue->listen_opt;
580 struct request_sock **prev;
583 spin_lock(&queue->syn_wait_lock);
585 for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
586 prev = &(*prev)->dl_next) {
588 *prev = req->dl_next;
594 spin_unlock(&queue->syn_wait_lock);
595 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
600 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
602 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
603 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
607 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
609 static void reqsk_timer_handler(unsigned long data)
611 struct request_sock *req = (struct request_sock *)data;
612 struct sock *sk_listener = req->rsk_listener;
613 struct inet_connection_sock *icsk = inet_csk(sk_listener);
614 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
615 struct listen_sock *lopt = queue->listen_opt;
616 int qlen, expire = 0, resend = 0;
617 int max_retries, thresh;
620 if (sk_listener->sk_state != TCP_LISTEN || !lopt) {
625 max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
626 thresh = max_retries;
627 /* Normally all the openreqs are young and become mature
628 * (i.e. converted to established socket) for first timeout.
629 * If synack was not acknowledged for 1 second, it means
630 * one of the following things: synack was lost, ack was lost,
631 * rtt is high or nobody planned to ack (i.e. synflood).
632 * When server is a bit loaded, queue is populated with old
633 * open requests, reducing effective size of queue.
634 * When server is well loaded, queue size reduces to zero
635 * after several minutes of work. It is not synflood,
636 * it is normal operation. The solution is pruning
637 * too old entries overriding normal timeout, when
638 * situation becomes dangerous.
640 * Essentially, we reserve half of room for young
641 * embrions; and abort old ones without pity, if old
642 * ones are about to clog our table.
644 qlen = listen_sock_qlen(lopt);
645 if (qlen >> (lopt->max_qlen_log - 1)) {
646 int young = listen_sock_young(lopt) << 1;
655 defer_accept = READ_ONCE(queue->rskq_defer_accept);
657 max_retries = defer_accept;
658 syn_ack_recalc(req, thresh, max_retries, defer_accept,
660 req->rsk_ops->syn_ack_timeout(req);
663 !inet_rtx_syn_ack(sk_listener, req) ||
664 inet_rsk(req)->acked)) {
667 if (req->num_timeout++ == 0)
668 atomic_inc(&lopt->young_dec);
669 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
670 mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
673 inet_csk_reqsk_queue_drop(sk_listener, req);
677 void reqsk_queue_hash_req(struct request_sock_queue *queue,
678 u32 hash, struct request_sock *req,
679 unsigned long timeout)
681 struct listen_sock *lopt = queue->listen_opt;
683 req->num_retrans = 0;
684 req->num_timeout = 0;
687 setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
688 mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
689 req->rsk_hash = hash;
691 /* before letting lookups find us, make sure all req fields
692 * are committed to memory and refcnt initialized.
695 atomic_set(&req->rsk_refcnt, 2);
697 spin_lock(&queue->syn_wait_lock);
698 req->dl_next = lopt->syn_table[hash];
699 lopt->syn_table[hash] = req;
700 spin_unlock(&queue->syn_wait_lock);
702 EXPORT_SYMBOL(reqsk_queue_hash_req);
705 * inet_csk_clone_lock - clone an inet socket, and lock its clone
706 * @sk: the socket to clone
708 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
710 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
712 struct sock *inet_csk_clone_lock(const struct sock *sk,
713 const struct request_sock *req,
714 const gfp_t priority)
716 struct sock *newsk = sk_clone_lock(sk, priority);
719 struct inet_connection_sock *newicsk = inet_csk(newsk);
721 newsk->sk_state = TCP_SYN_RECV;
722 newicsk->icsk_bind_hash = NULL;
724 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
725 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
726 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
727 newsk->sk_write_space = sk_stream_write_space;
729 newsk->sk_mark = inet_rsk(req)->ir_mark;
730 atomic64_set(&newsk->sk_cookie,
731 atomic64_read(&inet_rsk(req)->ir_cookie));
733 newicsk->icsk_retransmits = 0;
734 newicsk->icsk_backoff = 0;
735 newicsk->icsk_probes_out = 0;
737 /* Deinitialize accept_queue to trap illegal accesses. */
738 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
740 security_inet_csk_clone(newsk, req);
744 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
747 * At this point, there should be no process reference to this
748 * socket, and thus no user references at all. Therefore we
749 * can assume the socket waitqueue is inactive and nobody will
750 * try to jump onto it.
752 void inet_csk_destroy_sock(struct sock *sk)
754 WARN_ON(sk->sk_state != TCP_CLOSE);
755 WARN_ON(!sock_flag(sk, SOCK_DEAD));
757 /* It cannot be in hash table! */
758 WARN_ON(!sk_unhashed(sk));
760 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
761 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
763 sk->sk_prot->destroy(sk);
765 sk_stream_kill_queues(sk);
767 xfrm_sk_free_policy(sk);
769 sk_refcnt_debug_release(sk);
771 percpu_counter_dec(sk->sk_prot->orphan_count);
774 EXPORT_SYMBOL(inet_csk_destroy_sock);
776 /* This function allows to force a closure of a socket after the call to
777 * tcp/dccp_create_openreq_child().
779 void inet_csk_prepare_forced_close(struct sock *sk)
780 __releases(&sk->sk_lock.slock)
782 /* sk_clone_lock locked the socket and set refcnt to 2 */
786 /* The below has to be done to allow calling inet_csk_destroy_sock */
787 sock_set_flag(sk, SOCK_DEAD);
788 percpu_counter_inc(sk->sk_prot->orphan_count);
789 inet_sk(sk)->inet_num = 0;
791 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
793 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
795 struct inet_sock *inet = inet_sk(sk);
796 struct inet_connection_sock *icsk = inet_csk(sk);
797 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
802 sk->sk_max_ack_backlog = 0;
803 sk->sk_ack_backlog = 0;
804 inet_csk_delack_init(sk);
806 /* There is race window here: we announce ourselves listening,
807 * but this transition is still not validated by get_port().
808 * It is OK, because this socket enters to hash table only
809 * after validation is complete.
811 sk->sk_state = TCP_LISTEN;
812 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
813 inet->inet_sport = htons(inet->inet_num);
816 sk->sk_prot->hash(sk);
821 sk->sk_state = TCP_CLOSE;
822 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
825 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
828 * This routine closes sockets which have been at least partially
829 * opened, but not yet accepted.
831 void inet_csk_listen_stop(struct sock *sk)
833 struct inet_connection_sock *icsk = inet_csk(sk);
834 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
835 struct request_sock *acc_req;
836 struct request_sock *req;
838 /* make all the listen_opt local to us */
839 acc_req = reqsk_queue_yank_acceptq(queue);
841 /* Following specs, it would be better either to send FIN
842 * (and enter FIN-WAIT-1, it is normal close)
843 * or to send active reset (abort).
844 * Certainly, it is pretty dangerous while synflood, but it is
845 * bad justification for our negligence 8)
846 * To be honest, we are not able to make either
847 * of the variants now. --ANK
849 reqsk_queue_destroy(queue);
851 while ((req = acc_req) != NULL) {
852 struct sock *child = req->sk;
854 acc_req = req->dl_next;
858 WARN_ON(sock_owned_by_user(child));
861 sk->sk_prot->disconnect(child, O_NONBLOCK);
865 percpu_counter_inc(sk->sk_prot->orphan_count);
867 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
868 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
869 BUG_ON(sk != req->rsk_listener);
871 /* Paranoid, to prevent race condition if
872 * an inbound pkt destined for child is
873 * blocked by sock lock in tcp_v4_rcv().
874 * Also to satisfy an assertion in
875 * tcp_v4_destroy_sock().
877 tcp_sk(child)->fastopen_rsk = NULL;
879 inet_csk_destroy_sock(child);
881 bh_unlock_sock(child);
885 sk_acceptq_removed(sk);
888 if (queue->fastopenq.rskq_rst_head) {
889 /* Free all the reqs queued in rskq_rst_head. */
890 spin_lock_bh(&queue->fastopenq.lock);
891 acc_req = queue->fastopenq.rskq_rst_head;
892 queue->fastopenq.rskq_rst_head = NULL;
893 spin_unlock_bh(&queue->fastopenq.lock);
894 while ((req = acc_req) != NULL) {
895 acc_req = req->dl_next;
899 WARN_ON(sk->sk_ack_backlog);
901 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
903 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
905 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
906 const struct inet_sock *inet = inet_sk(sk);
908 sin->sin_family = AF_INET;
909 sin->sin_addr.s_addr = inet->inet_daddr;
910 sin->sin_port = inet->inet_dport;
912 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
915 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
916 char __user *optval, int __user *optlen)
918 const struct inet_connection_sock *icsk = inet_csk(sk);
920 if (icsk->icsk_af_ops->compat_getsockopt)
921 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
923 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
926 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
928 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
929 char __user *optval, unsigned int optlen)
931 const struct inet_connection_sock *icsk = inet_csk(sk);
933 if (icsk->icsk_af_ops->compat_setsockopt)
934 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
936 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
939 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
942 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
944 const struct inet_sock *inet = inet_sk(sk);
945 const struct ip_options_rcu *inet_opt;
946 __be32 daddr = inet->inet_daddr;
951 inet_opt = rcu_dereference(inet->inet_opt);
952 if (inet_opt && inet_opt->opt.srr)
953 daddr = inet_opt->opt.faddr;
955 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
956 inet->inet_saddr, inet->inet_dport,
957 inet->inet_sport, sk->sk_protocol,
958 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
962 sk_setup_caps(sk, &rt->dst);
968 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
970 struct dst_entry *dst = __sk_dst_check(sk, 0);
971 struct inet_sock *inet = inet_sk(sk);
974 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
978 dst->ops->update_pmtu(dst, sk, NULL, mtu);
980 dst = __sk_dst_check(sk, 0);
982 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
986 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);