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>
28 #include <net/addrconf.h>
31 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
32 EXPORT_SYMBOL(inet_csk_timer_bug_msg);
35 #if IS_ENABLED(CONFIG_IPV6)
36 /* match_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
37 * only, and any IPv4 addresses if not IPv6 only
38 * match_wildcard == false: addresses must be exactly the same, i.e.
39 * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
40 * and 0.0.0.0 equals to 0.0.0.0 only
42 static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
43 const struct in6_addr *sk2_rcv_saddr6,
44 __be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
45 bool sk1_ipv6only, bool sk2_ipv6only,
48 int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
49 int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
51 /* if both are mapped, treat as IPv4 */
52 if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
54 if (sk1_rcv_saddr == sk2_rcv_saddr)
56 if (!sk1_rcv_saddr || !sk2_rcv_saddr)
57 return match_wildcard;
62 if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
65 if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
66 !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
69 if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
70 !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
74 ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
81 /* match_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
82 * match_wildcard == false: addresses must be exactly the same, i.e.
83 * 0.0.0.0 only equals to 0.0.0.0
85 static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
86 bool sk2_ipv6only, bool match_wildcard)
89 if (sk1_rcv_saddr == sk2_rcv_saddr)
91 if (!sk1_rcv_saddr || !sk2_rcv_saddr)
92 return match_wildcard;
97 bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
100 #if IS_ENABLED(CONFIG_IPV6)
101 if (sk->sk_family == AF_INET6)
102 return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
103 inet6_rcv_saddr(sk2),
110 return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
111 ipv6_only_sock(sk2), match_wildcard);
113 EXPORT_SYMBOL(inet_rcv_saddr_equal);
115 void inet_get_local_port_range(struct net *net, int *low, int *high)
120 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
122 *low = net->ipv4.ip_local_ports.range[0];
123 *high = net->ipv4.ip_local_ports.range[1];
124 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
126 EXPORT_SYMBOL(inet_get_local_port_range);
128 static int inet_csk_bind_conflict(const struct sock *sk,
129 const struct inet_bind_bucket *tb,
130 bool relax, bool reuseport_ok)
133 bool reuse = sk->sk_reuse;
134 bool reuseport = !!sk->sk_reuseport && reuseport_ok;
135 kuid_t uid = sock_i_uid((struct sock *)sk);
138 * Unlike other sk lookup places we do not check
139 * for sk_net here, since _all_ the socks listed
140 * in tb->owners list belong to the same net - the
141 * one this bucket belongs to.
144 sk_for_each_bound(sk2, &tb->owners) {
146 (!sk->sk_bound_dev_if ||
147 !sk2->sk_bound_dev_if ||
148 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
149 if ((!reuse || !sk2->sk_reuse ||
150 sk2->sk_state == TCP_LISTEN) &&
151 (!reuseport || !sk2->sk_reuseport ||
152 rcu_access_pointer(sk->sk_reuseport_cb) ||
153 (sk2->sk_state != TCP_TIME_WAIT &&
154 !uid_eq(uid, sock_i_uid(sk2))))) {
155 if (inet_rcv_saddr_equal(sk, sk2, true))
158 if (!relax && reuse && sk2->sk_reuse &&
159 sk2->sk_state != TCP_LISTEN) {
160 if (inet_rcv_saddr_equal(sk, sk2, true))
169 * Find an open port number for the socket. Returns with the
170 * inet_bind_hashbucket lock held.
172 static struct inet_bind_hashbucket *
173 inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret)
175 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
177 struct inet_bind_hashbucket *head;
178 struct net *net = sock_net(sk);
179 int i, low, high, attempt_half;
180 struct inet_bind_bucket *tb;
181 u32 remaining, offset;
183 attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
185 inet_get_local_port_range(net, &low, &high);
186 high++; /* [32768, 60999] -> [32768, 61000[ */
190 int half = low + (((high - low) >> 2) << 1);
192 if (attempt_half == 1)
197 remaining = high - low;
198 if (likely(remaining > 1))
201 offset = prandom_u32() % remaining;
202 /* __inet_hash_connect() favors ports having @low parity
203 * We do the opposite to not pollute connect() users.
209 for (i = 0; i < remaining; i += 2, port += 2) {
210 if (unlikely(port >= high))
212 if (inet_is_local_reserved_port(net, port))
214 head = &hinfo->bhash[inet_bhashfn(net, port,
216 spin_lock_bh(&head->lock);
217 inet_bind_bucket_for_each(tb, &head->chain)
218 if (net_eq(ib_net(tb), net) && tb->port == port) {
219 if (!inet_csk_bind_conflict(sk, tb, false, false))
226 spin_unlock_bh(&head->lock);
232 goto other_parity_scan;
234 if (attempt_half == 1) {
235 /* OK we now try the upper half of the range */
237 goto other_half_scan;
246 static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
249 kuid_t uid = sock_i_uid(sk);
251 if (tb->fastreuseport <= 0)
253 if (!sk->sk_reuseport)
255 if (rcu_access_pointer(sk->sk_reuseport_cb))
257 if (!uid_eq(tb->fastuid, uid))
259 /* We only need to check the rcv_saddr if this tb was once marked
260 * without fastreuseport and then was reset, as we can only know that
261 * the fast_*rcv_saddr doesn't have any conflicts with the socks on the
264 if (tb->fastreuseport == FASTREUSEPORT_ANY)
266 #if IS_ENABLED(CONFIG_IPV6)
267 if (tb->fast_sk_family == AF_INET6)
268 return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
273 ipv6_only_sock(sk), true);
275 return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
276 ipv6_only_sock(sk), true);
279 /* Obtain a reference to a local port for the given sock,
280 * if snum is zero it means select any available local port.
281 * We try to allocate an odd port (and leave even ports for connect())
283 int inet_csk_get_port(struct sock *sk, unsigned short snum)
285 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
286 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
287 int ret = 1, port = snum;
288 struct inet_bind_hashbucket *head;
289 struct net *net = sock_net(sk);
290 struct inet_bind_bucket *tb = NULL;
291 kuid_t uid = sock_i_uid(sk);
294 head = inet_csk_find_open_port(sk, &tb, &port);
301 head = &hinfo->bhash[inet_bhashfn(net, port,
303 spin_lock_bh(&head->lock);
304 inet_bind_bucket_for_each(tb, &head->chain)
305 if (net_eq(ib_net(tb), net) && tb->port == port)
308 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
313 if (!hlist_empty(&tb->owners)) {
314 if (sk->sk_reuse == SK_FORCE_REUSE)
317 if ((tb->fastreuse > 0 && reuse) ||
318 sk_reuseport_match(tb, sk))
320 if (inet_csk_bind_conflict(sk, tb, true, true))
324 if (hlist_empty(&tb->owners)) {
325 tb->fastreuse = reuse;
326 if (sk->sk_reuseport) {
327 tb->fastreuseport = FASTREUSEPORT_ANY;
329 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
330 tb->fast_ipv6_only = ipv6_only_sock(sk);
331 tb->fast_sk_family = sk->sk_family;
332 #if IS_ENABLED(CONFIG_IPV6)
333 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
336 tb->fastreuseport = 0;
341 if (sk->sk_reuseport) {
342 /* We didn't match or we don't have fastreuseport set on
343 * the tb, but we have sk_reuseport set on this socket
344 * and we know that there are no bind conflicts with
345 * this socket in this tb, so reset our tb's reuseport
346 * settings so that any subsequent sockets that match
347 * our current socket will be put on the fast path.
349 * If we reset we need to set FASTREUSEPORT_STRICT so we
350 * do extra checking for all subsequent sk_reuseport
353 if (!sk_reuseport_match(tb, sk)) {
354 tb->fastreuseport = FASTREUSEPORT_STRICT;
356 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
357 tb->fast_ipv6_only = ipv6_only_sock(sk);
358 tb->fast_sk_family = sk->sk_family;
359 #if IS_ENABLED(CONFIG_IPV6)
360 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
364 tb->fastreuseport = 0;
367 if (!inet_csk(sk)->icsk_bind_hash)
368 inet_bind_hash(sk, tb, port);
369 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
373 spin_unlock_bh(&head->lock);
376 EXPORT_SYMBOL_GPL(inet_csk_get_port);
379 * Wait for an incoming connection, avoid race conditions. This must be called
380 * with the socket locked.
382 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
384 struct inet_connection_sock *icsk = inet_csk(sk);
389 * True wake-one mechanism for incoming connections: only
390 * one process gets woken up, not the 'whole herd'.
391 * Since we do not 'race & poll' for established sockets
392 * anymore, the common case will execute the loop only once.
394 * Subtle issue: "add_wait_queue_exclusive()" will be added
395 * after any current non-exclusive waiters, and we know that
396 * it will always _stay_ after any new non-exclusive waiters
397 * because all non-exclusive waiters are added at the
398 * beginning of the wait-queue. As such, it's ok to "drop"
399 * our exclusiveness temporarily when we get woken up without
400 * having to remove and re-insert us on the wait queue.
403 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
406 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
407 timeo = schedule_timeout(timeo);
408 sched_annotate_sleep();
411 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
414 if (sk->sk_state != TCP_LISTEN)
416 err = sock_intr_errno(timeo);
417 if (signal_pending(current))
423 finish_wait(sk_sleep(sk), &wait);
428 * This will accept the next outstanding connection.
430 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
432 struct inet_connection_sock *icsk = inet_csk(sk);
433 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
434 struct request_sock *req;
440 /* We need to make sure that this socket is listening,
441 * and that it has something pending.
444 if (sk->sk_state != TCP_LISTEN)
447 /* Find already established connection */
448 if (reqsk_queue_empty(queue)) {
449 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
451 /* If this is a non blocking socket don't sleep */
456 error = inet_csk_wait_for_connect(sk, timeo);
460 req = reqsk_queue_remove(queue, sk);
463 if (sk->sk_protocol == IPPROTO_TCP &&
464 tcp_rsk(req)->tfo_listener) {
465 spin_lock_bh(&queue->fastopenq.lock);
466 if (tcp_rsk(req)->tfo_listener) {
467 /* We are still waiting for the final ACK from 3WHS
468 * so can't free req now. Instead, we set req->sk to
469 * NULL to signify that the child socket is taken
470 * so reqsk_fastopen_remove() will free the req
471 * when 3WHS finishes (or is aborted).
476 spin_unlock_bh(&queue->fastopenq.lock);
489 EXPORT_SYMBOL(inet_csk_accept);
492 * Using different timers for retransmit, delayed acks and probes
493 * We may wish use just one timer maintaining a list of expire jiffies
496 void inet_csk_init_xmit_timers(struct sock *sk,
497 void (*retransmit_handler)(struct timer_list *t),
498 void (*delack_handler)(struct timer_list *t),
499 void (*keepalive_handler)(struct timer_list *t))
501 struct inet_connection_sock *icsk = inet_csk(sk);
503 timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);
504 timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);
505 timer_setup(&sk->sk_timer, keepalive_handler, 0);
506 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
508 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
510 void inet_csk_clear_xmit_timers(struct sock *sk)
512 struct inet_connection_sock *icsk = inet_csk(sk);
514 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
516 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
517 sk_stop_timer(sk, &icsk->icsk_delack_timer);
518 sk_stop_timer(sk, &sk->sk_timer);
520 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
522 void inet_csk_delete_keepalive_timer(struct sock *sk)
524 sk_stop_timer(sk, &sk->sk_timer);
526 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
528 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
530 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
532 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
534 struct dst_entry *inet_csk_route_req(const struct sock *sk,
536 const struct request_sock *req)
538 const struct inet_request_sock *ireq = inet_rsk(req);
539 struct net *net = read_pnet(&ireq->ireq_net);
540 struct ip_options_rcu *opt;
543 opt = ireq_opt_deref(ireq);
545 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
546 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
547 sk->sk_protocol, inet_sk_flowi_flags(sk),
548 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
549 ireq->ir_loc_addr, ireq->ir_rmt_port,
550 htons(ireq->ir_num), sk->sk_uid);
551 security_req_classify_flow(req, flowi4_to_flowi(fl4));
552 rt = ip_route_output_flow(net, fl4, sk);
555 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
562 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
565 EXPORT_SYMBOL_GPL(inet_csk_route_req);
567 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
569 const struct request_sock *req)
571 const struct inet_request_sock *ireq = inet_rsk(req);
572 struct net *net = read_pnet(&ireq->ireq_net);
573 struct inet_sock *newinet = inet_sk(newsk);
574 struct ip_options_rcu *opt;
578 opt = rcu_dereference(ireq->ireq_opt);
579 fl4 = &newinet->cork.fl.u.ip4;
581 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
582 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
583 sk->sk_protocol, inet_sk_flowi_flags(sk),
584 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
585 ireq->ir_loc_addr, ireq->ir_rmt_port,
586 htons(ireq->ir_num), sk->sk_uid);
587 security_req_classify_flow(req, flowi4_to_flowi(fl4));
588 rt = ip_route_output_flow(net, fl4, sk);
591 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
598 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
601 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
603 #if IS_ENABLED(CONFIG_IPV6)
604 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
606 #define AF_INET_FAMILY(fam) true
609 /* Decide when to expire the request and when to resend SYN-ACK */
610 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
611 const int max_retries,
612 const u8 rskq_defer_accept,
613 int *expire, int *resend)
615 if (!rskq_defer_accept) {
616 *expire = req->num_timeout >= thresh;
620 *expire = req->num_timeout >= thresh &&
621 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
623 * Do not resend while waiting for data after ACK,
624 * start to resend on end of deferring period to give
625 * last chance for data or ACK to create established socket.
627 *resend = !inet_rsk(req)->acked ||
628 req->num_timeout >= rskq_defer_accept - 1;
631 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
633 int err = req->rsk_ops->rtx_syn_ack(parent, req);
639 EXPORT_SYMBOL(inet_rtx_syn_ack);
641 /* return true if req was found in the ehash table */
642 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
643 struct request_sock *req)
645 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
648 if (sk_hashed(req_to_sk(req))) {
649 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
652 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
655 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
660 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
662 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
663 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
667 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
669 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
671 inet_csk_reqsk_queue_drop(sk, req);
674 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
676 static void reqsk_timer_handler(struct timer_list *t)
678 struct request_sock *req = from_timer(req, t, rsk_timer);
679 struct sock *sk_listener = req->rsk_listener;
680 struct net *net = sock_net(sk_listener);
681 struct inet_connection_sock *icsk = inet_csk(sk_listener);
682 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
683 int qlen, expire = 0, resend = 0;
684 int max_retries, thresh;
687 if (inet_sk_state_load(sk_listener) != TCP_LISTEN)
690 max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
691 thresh = max_retries;
692 /* Normally all the openreqs are young and become mature
693 * (i.e. converted to established socket) for first timeout.
694 * If synack was not acknowledged for 1 second, it means
695 * one of the following things: synack was lost, ack was lost,
696 * rtt is high or nobody planned to ack (i.e. synflood).
697 * When server is a bit loaded, queue is populated with old
698 * open requests, reducing effective size of queue.
699 * When server is well loaded, queue size reduces to zero
700 * after several minutes of work. It is not synflood,
701 * it is normal operation. The solution is pruning
702 * too old entries overriding normal timeout, when
703 * situation becomes dangerous.
705 * Essentially, we reserve half of room for young
706 * embrions; and abort old ones without pity, if old
707 * ones are about to clog our table.
709 qlen = reqsk_queue_len(queue);
710 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
711 int young = reqsk_queue_len_young(queue) << 1;
720 defer_accept = READ_ONCE(queue->rskq_defer_accept);
722 max_retries = defer_accept;
723 syn_ack_recalc(req, thresh, max_retries, defer_accept,
725 req->rsk_ops->syn_ack_timeout(req);
728 !inet_rtx_syn_ack(sk_listener, req) ||
729 inet_rsk(req)->acked)) {
732 if (req->num_timeout++ == 0)
733 atomic_dec(&queue->young);
734 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
735 mod_timer(&req->rsk_timer, jiffies + timeo);
739 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
742 static void reqsk_queue_hash_req(struct request_sock *req,
743 unsigned long timeout)
745 req->num_retrans = 0;
746 req->num_timeout = 0;
749 timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
750 mod_timer(&req->rsk_timer, jiffies + timeout);
752 inet_ehash_insert(req_to_sk(req), NULL);
753 /* before letting lookups find us, make sure all req fields
754 * are committed to memory and refcnt initialized.
757 refcount_set(&req->rsk_refcnt, 2 + 1);
760 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
761 unsigned long timeout)
763 reqsk_queue_hash_req(req, timeout);
764 inet_csk_reqsk_queue_added(sk);
766 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
769 * inet_csk_clone_lock - clone an inet socket, and lock its clone
770 * @sk: the socket to clone
772 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
774 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
776 struct sock *inet_csk_clone_lock(const struct sock *sk,
777 const struct request_sock *req,
778 const gfp_t priority)
780 struct sock *newsk = sk_clone_lock(sk, priority);
783 struct inet_connection_sock *newicsk = inet_csk(newsk);
785 inet_sk_set_state(newsk, TCP_SYN_RECV);
786 newicsk->icsk_bind_hash = NULL;
788 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
789 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
790 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
792 /* listeners have SOCK_RCU_FREE, not the children */
793 sock_reset_flag(newsk, SOCK_RCU_FREE);
795 inet_sk(newsk)->mc_list = NULL;
797 newsk->sk_mark = inet_rsk(req)->ir_mark;
798 atomic64_set(&newsk->sk_cookie,
799 atomic64_read(&inet_rsk(req)->ir_cookie));
801 newicsk->icsk_retransmits = 0;
802 newicsk->icsk_backoff = 0;
803 newicsk->icsk_probes_out = 0;
805 /* Deinitialize accept_queue to trap illegal accesses. */
806 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
808 security_inet_csk_clone(newsk, req);
812 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
815 * At this point, there should be no process reference to this
816 * socket, and thus no user references at all. Therefore we
817 * can assume the socket waitqueue is inactive and nobody will
818 * try to jump onto it.
820 void inet_csk_destroy_sock(struct sock *sk)
822 WARN_ON(sk->sk_state != TCP_CLOSE);
823 WARN_ON(!sock_flag(sk, SOCK_DEAD));
825 /* It cannot be in hash table! */
826 WARN_ON(!sk_unhashed(sk));
828 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
829 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
831 sk->sk_prot->destroy(sk);
833 sk_stream_kill_queues(sk);
835 xfrm_sk_free_policy(sk);
837 sk_refcnt_debug_release(sk);
839 percpu_counter_dec(sk->sk_prot->orphan_count);
843 EXPORT_SYMBOL(inet_csk_destroy_sock);
845 /* This function allows to force a closure of a socket after the call to
846 * tcp/dccp_create_openreq_child().
848 void inet_csk_prepare_forced_close(struct sock *sk)
849 __releases(&sk->sk_lock.slock)
851 /* sk_clone_lock locked the socket and set refcnt to 2 */
855 /* The below has to be done to allow calling inet_csk_destroy_sock */
856 sock_set_flag(sk, SOCK_DEAD);
857 percpu_counter_inc(sk->sk_prot->orphan_count);
858 inet_sk(sk)->inet_num = 0;
860 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
862 int inet_csk_listen_start(struct sock *sk, int backlog)
864 struct inet_connection_sock *icsk = inet_csk(sk);
865 struct inet_sock *inet = inet_sk(sk);
866 int err = -EADDRINUSE;
868 reqsk_queue_alloc(&icsk->icsk_accept_queue);
870 sk->sk_max_ack_backlog = backlog;
871 sk->sk_ack_backlog = 0;
872 inet_csk_delack_init(sk);
874 /* There is race window here: we announce ourselves listening,
875 * but this transition is still not validated by get_port().
876 * It is OK, because this socket enters to hash table only
877 * after validation is complete.
879 inet_sk_state_store(sk, TCP_LISTEN);
880 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
881 inet->inet_sport = htons(inet->inet_num);
884 err = sk->sk_prot->hash(sk);
890 inet_sk_set_state(sk, TCP_CLOSE);
893 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
895 static void inet_child_forget(struct sock *sk, struct request_sock *req,
898 sk->sk_prot->disconnect(child, O_NONBLOCK);
902 percpu_counter_inc(sk->sk_prot->orphan_count);
904 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
905 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
906 BUG_ON(sk != req->rsk_listener);
908 /* Paranoid, to prevent race condition if
909 * an inbound pkt destined for child is
910 * blocked by sock lock in tcp_v4_rcv().
911 * Also to satisfy an assertion in
912 * tcp_v4_destroy_sock().
914 tcp_sk(child)->fastopen_rsk = NULL;
916 inet_csk_destroy_sock(child);
919 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
920 struct request_sock *req,
923 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
925 spin_lock(&queue->rskq_lock);
926 if (unlikely(sk->sk_state != TCP_LISTEN)) {
927 inet_child_forget(sk, req, child);
932 if (queue->rskq_accept_head == NULL)
933 queue->rskq_accept_head = req;
935 queue->rskq_accept_tail->dl_next = req;
936 queue->rskq_accept_tail = req;
937 sk_acceptq_added(sk);
939 spin_unlock(&queue->rskq_lock);
942 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
944 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
945 struct request_sock *req, bool own_req)
948 inet_csk_reqsk_queue_drop(sk, req);
949 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
950 if (inet_csk_reqsk_queue_add(sk, req, child))
953 /* Too bad, another child took ownership of the request, undo. */
954 bh_unlock_sock(child);
958 EXPORT_SYMBOL(inet_csk_complete_hashdance);
961 * This routine closes sockets which have been at least partially
962 * opened, but not yet accepted.
964 void inet_csk_listen_stop(struct sock *sk)
966 struct inet_connection_sock *icsk = inet_csk(sk);
967 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
968 struct request_sock *next, *req;
970 /* Following specs, it would be better either to send FIN
971 * (and enter FIN-WAIT-1, it is normal close)
972 * or to send active reset (abort).
973 * Certainly, it is pretty dangerous while synflood, but it is
974 * bad justification for our negligence 8)
975 * To be honest, we are not able to make either
976 * of the variants now. --ANK
978 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
979 struct sock *child = req->sk;
983 WARN_ON(sock_owned_by_user(child));
986 inet_child_forget(sk, req, child);
988 bh_unlock_sock(child);
994 if (queue->fastopenq.rskq_rst_head) {
995 /* Free all the reqs queued in rskq_rst_head. */
996 spin_lock_bh(&queue->fastopenq.lock);
997 req = queue->fastopenq.rskq_rst_head;
998 queue->fastopenq.rskq_rst_head = NULL;
999 spin_unlock_bh(&queue->fastopenq.lock);
1000 while (req != NULL) {
1001 next = req->dl_next;
1006 WARN_ON_ONCE(sk->sk_ack_backlog);
1008 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
1010 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
1012 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
1013 const struct inet_sock *inet = inet_sk(sk);
1015 sin->sin_family = AF_INET;
1016 sin->sin_addr.s_addr = inet->inet_daddr;
1017 sin->sin_port = inet->inet_dport;
1019 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
1021 #ifdef CONFIG_COMPAT
1022 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
1023 char __user *optval, int __user *optlen)
1025 const struct inet_connection_sock *icsk = inet_csk(sk);
1027 if (icsk->icsk_af_ops->compat_getsockopt)
1028 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
1030 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
1033 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
1035 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
1036 char __user *optval, unsigned int optlen)
1038 const struct inet_connection_sock *icsk = inet_csk(sk);
1040 if (icsk->icsk_af_ops->compat_setsockopt)
1041 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
1043 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
1046 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
1049 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
1051 const struct inet_sock *inet = inet_sk(sk);
1052 const struct ip_options_rcu *inet_opt;
1053 __be32 daddr = inet->inet_daddr;
1058 inet_opt = rcu_dereference(inet->inet_opt);
1059 if (inet_opt && inet_opt->opt.srr)
1060 daddr = inet_opt->opt.faddr;
1062 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
1063 inet->inet_saddr, inet->inet_dport,
1064 inet->inet_sport, sk->sk_protocol,
1065 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
1069 sk_setup_caps(sk, &rt->dst);
1075 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
1077 struct dst_entry *dst = __sk_dst_check(sk, 0);
1078 struct inet_sock *inet = inet_sk(sk);
1081 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1085 dst->ops->update_pmtu(dst, sk, NULL, mtu);
1087 dst = __sk_dst_check(sk, 0);
1089 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1093 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);