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>
30 #if IS_ENABLED(CONFIG_IPV6)
31 /* match_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
32 * only, and any IPv4 addresses if not IPv6 only
33 * match_wildcard == false: addresses must be exactly the same, i.e.
34 * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
35 * and 0.0.0.0 equals to 0.0.0.0 only
37 static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
38 const struct in6_addr *sk2_rcv_saddr6,
39 __be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
40 bool sk1_ipv6only, bool sk2_ipv6only,
43 int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
44 int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
46 /* if both are mapped, treat as IPv4 */
47 if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
49 if (sk1_rcv_saddr == sk2_rcv_saddr)
51 if (!sk1_rcv_saddr || !sk2_rcv_saddr)
52 return match_wildcard;
57 if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
60 if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
61 !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
64 if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
65 !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
69 ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
76 /* match_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
77 * match_wildcard == false: addresses must be exactly the same, i.e.
78 * 0.0.0.0 only equals to 0.0.0.0
80 static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
81 bool sk2_ipv6only, bool match_wildcard)
84 if (sk1_rcv_saddr == sk2_rcv_saddr)
86 if (!sk1_rcv_saddr || !sk2_rcv_saddr)
87 return match_wildcard;
92 bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
95 #if IS_ENABLED(CONFIG_IPV6)
96 if (sk->sk_family == AF_INET6)
97 return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
105 return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
106 ipv6_only_sock(sk2), match_wildcard);
108 EXPORT_SYMBOL(inet_rcv_saddr_equal);
110 bool inet_rcv_saddr_any(const struct sock *sk)
112 #if IS_ENABLED(CONFIG_IPV6)
113 if (sk->sk_family == AF_INET6)
114 return ipv6_addr_any(&sk->sk_v6_rcv_saddr);
116 return !sk->sk_rcv_saddr;
119 void inet_get_local_port_range(struct net *net, int *low, int *high)
124 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
126 *low = net->ipv4.ip_local_ports.range[0];
127 *high = net->ipv4.ip_local_ports.range[1];
128 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
130 EXPORT_SYMBOL(inet_get_local_port_range);
132 static int inet_csk_bind_conflict(const struct sock *sk,
133 const struct inet_bind_bucket *tb,
134 bool relax, bool reuseport_ok)
137 bool reuse = sk->sk_reuse;
138 bool reuseport = !!sk->sk_reuseport && reuseport_ok;
139 kuid_t uid = sock_i_uid((struct sock *)sk);
142 * Unlike other sk lookup places we do not check
143 * for sk_net here, since _all_ the socks listed
144 * in tb->owners list belong to the same net - the
145 * one this bucket belongs to.
148 sk_for_each_bound(sk2, &tb->owners) {
150 (!sk->sk_bound_dev_if ||
151 !sk2->sk_bound_dev_if ||
152 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
153 if ((!reuse || !sk2->sk_reuse ||
154 sk2->sk_state == TCP_LISTEN) &&
155 (!reuseport || !sk2->sk_reuseport ||
156 rcu_access_pointer(sk->sk_reuseport_cb) ||
157 (sk2->sk_state != TCP_TIME_WAIT &&
158 !uid_eq(uid, sock_i_uid(sk2))))) {
159 if (inet_rcv_saddr_equal(sk, sk2, true))
162 if (!relax && reuse && sk2->sk_reuse &&
163 sk2->sk_state != TCP_LISTEN) {
164 if (inet_rcv_saddr_equal(sk, sk2, true))
173 * Find an open port number for the socket. Returns with the
174 * inet_bind_hashbucket lock held.
176 static struct inet_bind_hashbucket *
177 inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret)
179 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
181 struct inet_bind_hashbucket *head;
182 struct net *net = sock_net(sk);
183 int i, low, high, attempt_half;
184 struct inet_bind_bucket *tb;
185 u32 remaining, offset;
187 attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
189 inet_get_local_port_range(net, &low, &high);
190 high++; /* [32768, 60999] -> [32768, 61000[ */
194 int half = low + (((high - low) >> 2) << 1);
196 if (attempt_half == 1)
201 remaining = high - low;
202 if (likely(remaining > 1))
205 offset = prandom_u32() % remaining;
206 /* __inet_hash_connect() favors ports having @low parity
207 * We do the opposite to not pollute connect() users.
213 for (i = 0; i < remaining; i += 2, port += 2) {
214 if (unlikely(port >= high))
216 if (inet_is_local_reserved_port(net, port))
218 head = &hinfo->bhash[inet_bhashfn(net, port,
220 spin_lock_bh(&head->lock);
221 inet_bind_bucket_for_each(tb, &head->chain)
222 if (net_eq(ib_net(tb), net) && tb->port == port) {
223 if (!inet_csk_bind_conflict(sk, tb, false, false))
230 spin_unlock_bh(&head->lock);
236 goto other_parity_scan;
238 if (attempt_half == 1) {
239 /* OK we now try the upper half of the range */
241 goto other_half_scan;
250 static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
253 kuid_t uid = sock_i_uid(sk);
255 if (tb->fastreuseport <= 0)
257 if (!sk->sk_reuseport)
259 if (rcu_access_pointer(sk->sk_reuseport_cb))
261 if (!uid_eq(tb->fastuid, uid))
263 /* We only need to check the rcv_saddr if this tb was once marked
264 * without fastreuseport and then was reset, as we can only know that
265 * the fast_*rcv_saddr doesn't have any conflicts with the socks on the
268 if (tb->fastreuseport == FASTREUSEPORT_ANY)
270 #if IS_ENABLED(CONFIG_IPV6)
271 if (tb->fast_sk_family == AF_INET6)
272 return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
277 ipv6_only_sock(sk), true);
279 return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
280 ipv6_only_sock(sk), true);
283 /* Obtain a reference to a local port for the given sock,
284 * if snum is zero it means select any available local port.
285 * We try to allocate an odd port (and leave even ports for connect())
287 int inet_csk_get_port(struct sock *sk, unsigned short snum)
289 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
290 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
291 int ret = 1, port = snum;
292 struct inet_bind_hashbucket *head;
293 struct net *net = sock_net(sk);
294 struct inet_bind_bucket *tb = NULL;
295 kuid_t uid = sock_i_uid(sk);
298 head = inet_csk_find_open_port(sk, &tb, &port);
305 head = &hinfo->bhash[inet_bhashfn(net, port,
307 spin_lock_bh(&head->lock);
308 inet_bind_bucket_for_each(tb, &head->chain)
309 if (net_eq(ib_net(tb), net) && tb->port == port)
312 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
317 if (!hlist_empty(&tb->owners)) {
318 if (sk->sk_reuse == SK_FORCE_REUSE)
321 if ((tb->fastreuse > 0 && reuse) ||
322 sk_reuseport_match(tb, sk))
324 if (inet_csk_bind_conflict(sk, tb, true, true))
328 if (hlist_empty(&tb->owners)) {
329 tb->fastreuse = reuse;
330 if (sk->sk_reuseport) {
331 tb->fastreuseport = FASTREUSEPORT_ANY;
333 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
334 tb->fast_ipv6_only = ipv6_only_sock(sk);
335 tb->fast_sk_family = sk->sk_family;
336 #if IS_ENABLED(CONFIG_IPV6)
337 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
340 tb->fastreuseport = 0;
345 if (sk->sk_reuseport) {
346 /* We didn't match or we don't have fastreuseport set on
347 * the tb, but we have sk_reuseport set on this socket
348 * and we know that there are no bind conflicts with
349 * this socket in this tb, so reset our tb's reuseport
350 * settings so that any subsequent sockets that match
351 * our current socket will be put on the fast path.
353 * If we reset we need to set FASTREUSEPORT_STRICT so we
354 * do extra checking for all subsequent sk_reuseport
357 if (!sk_reuseport_match(tb, sk)) {
358 tb->fastreuseport = FASTREUSEPORT_STRICT;
360 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
361 tb->fast_ipv6_only = ipv6_only_sock(sk);
362 tb->fast_sk_family = sk->sk_family;
363 #if IS_ENABLED(CONFIG_IPV6)
364 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
368 tb->fastreuseport = 0;
371 if (!inet_csk(sk)->icsk_bind_hash)
372 inet_bind_hash(sk, tb, port);
373 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
377 spin_unlock_bh(&head->lock);
380 EXPORT_SYMBOL_GPL(inet_csk_get_port);
383 * Wait for an incoming connection, avoid race conditions. This must be called
384 * with the socket locked.
386 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
388 struct inet_connection_sock *icsk = inet_csk(sk);
393 * True wake-one mechanism for incoming connections: only
394 * one process gets woken up, not the 'whole herd'.
395 * Since we do not 'race & poll' for established sockets
396 * anymore, the common case will execute the loop only once.
398 * Subtle issue: "add_wait_queue_exclusive()" will be added
399 * after any current non-exclusive waiters, and we know that
400 * it will always _stay_ after any new non-exclusive waiters
401 * because all non-exclusive waiters are added at the
402 * beginning of the wait-queue. As such, it's ok to "drop"
403 * our exclusiveness temporarily when we get woken up without
404 * having to remove and re-insert us on the wait queue.
407 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
410 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
411 timeo = schedule_timeout(timeo);
412 sched_annotate_sleep();
415 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
418 if (sk->sk_state != TCP_LISTEN)
420 err = sock_intr_errno(timeo);
421 if (signal_pending(current))
427 finish_wait(sk_sleep(sk), &wait);
432 * This will accept the next outstanding connection.
434 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
436 struct inet_connection_sock *icsk = inet_csk(sk);
437 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
438 struct request_sock *req;
444 /* We need to make sure that this socket is listening,
445 * and that it has something pending.
448 if (sk->sk_state != TCP_LISTEN)
451 /* Find already established connection */
452 if (reqsk_queue_empty(queue)) {
453 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
455 /* If this is a non blocking socket don't sleep */
460 error = inet_csk_wait_for_connect(sk, timeo);
464 req = reqsk_queue_remove(queue, sk);
467 if (sk->sk_protocol == IPPROTO_TCP &&
468 tcp_rsk(req)->tfo_listener) {
469 spin_lock_bh(&queue->fastopenq.lock);
470 if (tcp_rsk(req)->tfo_listener) {
471 /* We are still waiting for the final ACK from 3WHS
472 * so can't free req now. Instead, we set req->sk to
473 * NULL to signify that the child socket is taken
474 * so reqsk_fastopen_remove() will free the req
475 * when 3WHS finishes (or is aborted).
480 spin_unlock_bh(&queue->fastopenq.lock);
493 EXPORT_SYMBOL(inet_csk_accept);
496 * Using different timers for retransmit, delayed acks and probes
497 * We may wish use just one timer maintaining a list of expire jiffies
500 void inet_csk_init_xmit_timers(struct sock *sk,
501 void (*retransmit_handler)(struct timer_list *t),
502 void (*delack_handler)(struct timer_list *t),
503 void (*keepalive_handler)(struct timer_list *t))
505 struct inet_connection_sock *icsk = inet_csk(sk);
507 timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);
508 timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);
509 timer_setup(&sk->sk_timer, keepalive_handler, 0);
510 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
512 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
514 void inet_csk_clear_xmit_timers(struct sock *sk)
516 struct inet_connection_sock *icsk = inet_csk(sk);
518 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
520 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
521 sk_stop_timer(sk, &icsk->icsk_delack_timer);
522 sk_stop_timer(sk, &sk->sk_timer);
524 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
526 void inet_csk_delete_keepalive_timer(struct sock *sk)
528 sk_stop_timer(sk, &sk->sk_timer);
530 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
532 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
534 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
536 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
538 struct dst_entry *inet_csk_route_req(const struct sock *sk,
540 const struct request_sock *req)
542 const struct inet_request_sock *ireq = inet_rsk(req);
543 struct net *net = read_pnet(&ireq->ireq_net);
544 struct ip_options_rcu *opt;
548 opt = rcu_dereference(ireq->ireq_opt);
550 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
551 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
552 sk->sk_protocol, inet_sk_flowi_flags(sk),
553 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
554 ireq->ir_loc_addr, ireq->ir_rmt_port,
555 htons(ireq->ir_num), sk->sk_uid);
556 security_req_classify_flow(req, flowi4_to_flowi(fl4));
557 rt = ip_route_output_flow(net, fl4, sk);
560 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
569 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
572 EXPORT_SYMBOL_GPL(inet_csk_route_req);
574 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
576 const struct request_sock *req)
578 const struct inet_request_sock *ireq = inet_rsk(req);
579 struct net *net = read_pnet(&ireq->ireq_net);
580 struct inet_sock *newinet = inet_sk(newsk);
581 struct ip_options_rcu *opt;
585 opt = rcu_dereference(ireq->ireq_opt);
586 fl4 = &newinet->cork.fl.u.ip4;
588 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
589 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
590 sk->sk_protocol, inet_sk_flowi_flags(sk),
591 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
592 ireq->ir_loc_addr, ireq->ir_rmt_port,
593 htons(ireq->ir_num), sk->sk_uid);
594 security_req_classify_flow(req, flowi4_to_flowi(fl4));
595 rt = ip_route_output_flow(net, fl4, sk);
598 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
605 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
608 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
610 #if IS_ENABLED(CONFIG_IPV6)
611 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
613 #define AF_INET_FAMILY(fam) true
616 /* Decide when to expire the request and when to resend SYN-ACK */
617 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
618 const int max_retries,
619 const u8 rskq_defer_accept,
620 int *expire, int *resend)
622 if (!rskq_defer_accept) {
623 *expire = req->num_timeout >= thresh;
627 *expire = req->num_timeout >= thresh &&
628 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
630 * Do not resend while waiting for data after ACK,
631 * start to resend on end of deferring period to give
632 * last chance for data or ACK to create established socket.
634 *resend = !inet_rsk(req)->acked ||
635 req->num_timeout >= rskq_defer_accept - 1;
638 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
640 int err = req->rsk_ops->rtx_syn_ack(parent, req);
646 EXPORT_SYMBOL(inet_rtx_syn_ack);
648 /* return true if req was found in the ehash table */
649 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
650 struct request_sock *req)
652 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
655 if (sk_hashed(req_to_sk(req))) {
656 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
659 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
662 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
667 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
669 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
670 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
674 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
676 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
678 inet_csk_reqsk_queue_drop(sk, req);
681 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
683 static void reqsk_timer_handler(struct timer_list *t)
685 struct request_sock *req = from_timer(req, t, rsk_timer);
686 struct sock *sk_listener = req->rsk_listener;
687 struct net *net = sock_net(sk_listener);
688 struct inet_connection_sock *icsk = inet_csk(sk_listener);
689 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
690 int qlen, expire = 0, resend = 0;
691 int max_retries, thresh;
694 if (inet_sk_state_load(sk_listener) != TCP_LISTEN)
697 max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
698 thresh = max_retries;
699 /* Normally all the openreqs are young and become mature
700 * (i.e. converted to established socket) for first timeout.
701 * If synack was not acknowledged for 1 second, it means
702 * one of the following things: synack was lost, ack was lost,
703 * rtt is high or nobody planned to ack (i.e. synflood).
704 * When server is a bit loaded, queue is populated with old
705 * open requests, reducing effective size of queue.
706 * When server is well loaded, queue size reduces to zero
707 * after several minutes of work. It is not synflood,
708 * it is normal operation. The solution is pruning
709 * too old entries overriding normal timeout, when
710 * situation becomes dangerous.
712 * Essentially, we reserve half of room for young
713 * embrions; and abort old ones without pity, if old
714 * ones are about to clog our table.
716 qlen = reqsk_queue_len(queue);
717 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
718 int young = reqsk_queue_len_young(queue) << 1;
727 defer_accept = READ_ONCE(queue->rskq_defer_accept);
729 max_retries = defer_accept;
730 syn_ack_recalc(req, thresh, max_retries, defer_accept,
732 req->rsk_ops->syn_ack_timeout(req);
735 !inet_rtx_syn_ack(sk_listener, req) ||
736 inet_rsk(req)->acked)) {
739 if (req->num_timeout++ == 0)
740 atomic_dec(&queue->young);
741 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
742 mod_timer(&req->rsk_timer, jiffies + timeo);
746 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
749 static void reqsk_queue_hash_req(struct request_sock *req,
750 unsigned long timeout)
752 req->num_retrans = 0;
753 req->num_timeout = 0;
756 timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
757 mod_timer(&req->rsk_timer, jiffies + timeout);
759 inet_ehash_insert(req_to_sk(req), NULL);
760 /* before letting lookups find us, make sure all req fields
761 * are committed to memory and refcnt initialized.
764 refcount_set(&req->rsk_refcnt, 2 + 1);
767 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
768 unsigned long timeout)
770 reqsk_queue_hash_req(req, timeout);
771 inet_csk_reqsk_queue_added(sk);
773 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
776 * inet_csk_clone_lock - clone an inet socket, and lock its clone
777 * @sk: the socket to clone
779 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
781 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
783 struct sock *inet_csk_clone_lock(const struct sock *sk,
784 const struct request_sock *req,
785 const gfp_t priority)
787 struct sock *newsk = sk_clone_lock(sk, priority);
790 struct inet_connection_sock *newicsk = inet_csk(newsk);
792 inet_sk_set_state(newsk, TCP_SYN_RECV);
793 newicsk->icsk_bind_hash = NULL;
795 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
796 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
797 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
799 /* listeners have SOCK_RCU_FREE, not the children */
800 sock_reset_flag(newsk, SOCK_RCU_FREE);
802 inet_sk(newsk)->mc_list = NULL;
804 newsk->sk_mark = inet_rsk(req)->ir_mark;
805 atomic64_set(&newsk->sk_cookie,
806 atomic64_read(&inet_rsk(req)->ir_cookie));
808 newicsk->icsk_retransmits = 0;
809 newicsk->icsk_backoff = 0;
810 newicsk->icsk_probes_out = 0;
812 /* Deinitialize accept_queue to trap illegal accesses. */
813 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
815 security_inet_csk_clone(newsk, req);
819 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
822 * At this point, there should be no process reference to this
823 * socket, and thus no user references at all. Therefore we
824 * can assume the socket waitqueue is inactive and nobody will
825 * try to jump onto it.
827 void inet_csk_destroy_sock(struct sock *sk)
829 WARN_ON(sk->sk_state != TCP_CLOSE);
830 WARN_ON(!sock_flag(sk, SOCK_DEAD));
832 /* It cannot be in hash table! */
833 WARN_ON(!sk_unhashed(sk));
835 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
836 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
838 sk->sk_prot->destroy(sk);
840 sk_stream_kill_queues(sk);
842 xfrm_sk_free_policy(sk);
844 sk_refcnt_debug_release(sk);
846 percpu_counter_dec(sk->sk_prot->orphan_count);
850 EXPORT_SYMBOL(inet_csk_destroy_sock);
852 /* This function allows to force a closure of a socket after the call to
853 * tcp/dccp_create_openreq_child().
855 void inet_csk_prepare_forced_close(struct sock *sk)
856 __releases(&sk->sk_lock.slock)
858 /* sk_clone_lock locked the socket and set refcnt to 2 */
862 /* The below has to be done to allow calling inet_csk_destroy_sock */
863 sock_set_flag(sk, SOCK_DEAD);
864 percpu_counter_inc(sk->sk_prot->orphan_count);
865 inet_sk(sk)->inet_num = 0;
867 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
869 int inet_csk_listen_start(struct sock *sk, int backlog)
871 struct inet_connection_sock *icsk = inet_csk(sk);
872 struct inet_sock *inet = inet_sk(sk);
873 int err = -EADDRINUSE;
875 reqsk_queue_alloc(&icsk->icsk_accept_queue);
877 sk->sk_max_ack_backlog = backlog;
878 sk->sk_ack_backlog = 0;
879 inet_csk_delack_init(sk);
881 /* There is race window here: we announce ourselves listening,
882 * but this transition is still not validated by get_port().
883 * It is OK, because this socket enters to hash table only
884 * after validation is complete.
886 inet_sk_state_store(sk, TCP_LISTEN);
887 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
888 inet->inet_sport = htons(inet->inet_num);
891 err = sk->sk_prot->hash(sk);
897 inet_sk_set_state(sk, TCP_CLOSE);
900 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
902 static void inet_child_forget(struct sock *sk, struct request_sock *req,
905 sk->sk_prot->disconnect(child, O_NONBLOCK);
909 percpu_counter_inc(sk->sk_prot->orphan_count);
911 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
912 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
913 BUG_ON(sk != req->rsk_listener);
915 /* Paranoid, to prevent race condition if
916 * an inbound pkt destined for child is
917 * blocked by sock lock in tcp_v4_rcv().
918 * Also to satisfy an assertion in
919 * tcp_v4_destroy_sock().
921 tcp_sk(child)->fastopen_rsk = NULL;
923 inet_csk_destroy_sock(child);
926 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
927 struct request_sock *req,
930 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
932 spin_lock(&queue->rskq_lock);
933 if (unlikely(sk->sk_state != TCP_LISTEN)) {
934 inet_child_forget(sk, req, child);
939 if (queue->rskq_accept_head == NULL)
940 queue->rskq_accept_head = req;
942 queue->rskq_accept_tail->dl_next = req;
943 queue->rskq_accept_tail = req;
944 sk_acceptq_added(sk);
946 spin_unlock(&queue->rskq_lock);
949 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
951 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
952 struct request_sock *req, bool own_req)
955 inet_csk_reqsk_queue_drop(sk, req);
956 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
957 if (inet_csk_reqsk_queue_add(sk, req, child))
960 /* Too bad, another child took ownership of the request, undo. */
961 bh_unlock_sock(child);
965 EXPORT_SYMBOL(inet_csk_complete_hashdance);
968 * This routine closes sockets which have been at least partially
969 * opened, but not yet accepted.
971 void inet_csk_listen_stop(struct sock *sk)
973 struct inet_connection_sock *icsk = inet_csk(sk);
974 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
975 struct request_sock *next, *req;
977 /* Following specs, it would be better either to send FIN
978 * (and enter FIN-WAIT-1, it is normal close)
979 * or to send active reset (abort).
980 * Certainly, it is pretty dangerous while synflood, but it is
981 * bad justification for our negligence 8)
982 * To be honest, we are not able to make either
983 * of the variants now. --ANK
985 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
986 struct sock *child = req->sk;
990 WARN_ON(sock_owned_by_user(child));
993 inet_child_forget(sk, req, child);
995 bh_unlock_sock(child);
1001 if (queue->fastopenq.rskq_rst_head) {
1002 /* Free all the reqs queued in rskq_rst_head. */
1003 spin_lock_bh(&queue->fastopenq.lock);
1004 req = queue->fastopenq.rskq_rst_head;
1005 queue->fastopenq.rskq_rst_head = NULL;
1006 spin_unlock_bh(&queue->fastopenq.lock);
1007 while (req != NULL) {
1008 next = req->dl_next;
1013 WARN_ON_ONCE(sk->sk_ack_backlog);
1015 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
1017 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
1019 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
1020 const struct inet_sock *inet = inet_sk(sk);
1022 sin->sin_family = AF_INET;
1023 sin->sin_addr.s_addr = inet->inet_daddr;
1024 sin->sin_port = inet->inet_dport;
1026 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
1028 #ifdef CONFIG_COMPAT
1029 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
1030 char __user *optval, int __user *optlen)
1032 const struct inet_connection_sock *icsk = inet_csk(sk);
1034 if (icsk->icsk_af_ops->compat_getsockopt)
1035 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
1037 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
1040 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
1042 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
1043 char __user *optval, unsigned int optlen)
1045 const struct inet_connection_sock *icsk = inet_csk(sk);
1047 if (icsk->icsk_af_ops->compat_setsockopt)
1048 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
1050 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
1053 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
1056 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
1058 const struct inet_sock *inet = inet_sk(sk);
1059 const struct ip_options_rcu *inet_opt;
1060 __be32 daddr = inet->inet_daddr;
1065 inet_opt = rcu_dereference(inet->inet_opt);
1066 if (inet_opt && inet_opt->opt.srr)
1067 daddr = inet_opt->opt.faddr;
1069 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
1070 inet->inet_saddr, inet->inet_dport,
1071 inet->inet_sport, sk->sk_protocol,
1072 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
1076 sk_setup_caps(sk, &rt->dst);
1082 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
1084 struct dst_entry *dst = __sk_dst_check(sk, 0);
1085 struct inet_sock *inet = inet_sk(sk);
1088 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1092 dst->ops->update_pmtu(dst, sk, NULL, mtu);
1094 dst = __sk_dst_check(sk, 0);
1096 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1100 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);