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 void inet_get_local_port_range(struct net *net, int *low, int *high)
115 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
117 *low = net->ipv4.ip_local_ports.range[0];
118 *high = net->ipv4.ip_local_ports.range[1];
119 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
121 EXPORT_SYMBOL(inet_get_local_port_range);
123 static int inet_csk_bind_conflict(const struct sock *sk,
124 const struct inet_bind_bucket *tb,
125 bool relax, bool reuseport_ok)
128 bool reuse = sk->sk_reuse;
129 bool reuseport = !!sk->sk_reuseport && reuseport_ok;
130 kuid_t uid = sock_i_uid((struct sock *)sk);
133 * Unlike other sk lookup places we do not check
134 * for sk_net here, since _all_ the socks listed
135 * in tb->owners list belong to the same net - the
136 * one this bucket belongs to.
139 sk_for_each_bound(sk2, &tb->owners) {
141 (!sk->sk_bound_dev_if ||
142 !sk2->sk_bound_dev_if ||
143 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
144 if ((!reuse || !sk2->sk_reuse ||
145 sk2->sk_state == TCP_LISTEN) &&
146 (!reuseport || !sk2->sk_reuseport ||
147 rcu_access_pointer(sk->sk_reuseport_cb) ||
148 (sk2->sk_state != TCP_TIME_WAIT &&
149 !uid_eq(uid, sock_i_uid(sk2))))) {
150 if (inet_rcv_saddr_equal(sk, sk2, true))
153 if (!relax && reuse && sk2->sk_reuse &&
154 sk2->sk_state != TCP_LISTEN) {
155 if (inet_rcv_saddr_equal(sk, sk2, true))
164 * Find an open port number for the socket. Returns with the
165 * inet_bind_hashbucket lock held.
167 static struct inet_bind_hashbucket *
168 inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret)
170 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
172 struct inet_bind_hashbucket *head;
173 struct net *net = sock_net(sk);
174 int i, low, high, attempt_half;
175 struct inet_bind_bucket *tb;
176 u32 remaining, offset;
178 attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
180 inet_get_local_port_range(net, &low, &high);
181 high++; /* [32768, 60999] -> [32768, 61000[ */
185 int half = low + (((high - low) >> 2) << 1);
187 if (attempt_half == 1)
192 remaining = high - low;
193 if (likely(remaining > 1))
196 offset = prandom_u32() % remaining;
197 /* __inet_hash_connect() favors ports having @low parity
198 * We do the opposite to not pollute connect() users.
204 for (i = 0; i < remaining; i += 2, port += 2) {
205 if (unlikely(port >= high))
207 if (inet_is_local_reserved_port(net, port))
209 head = &hinfo->bhash[inet_bhashfn(net, port,
211 spin_lock_bh(&head->lock);
212 inet_bind_bucket_for_each(tb, &head->chain)
213 if (net_eq(ib_net(tb), net) && tb->port == port) {
214 if (!inet_csk_bind_conflict(sk, tb, false, false))
221 spin_unlock_bh(&head->lock);
227 goto other_parity_scan;
229 if (attempt_half == 1) {
230 /* OK we now try the upper half of the range */
232 goto other_half_scan;
241 static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
244 kuid_t uid = sock_i_uid(sk);
246 if (tb->fastreuseport <= 0)
248 if (!sk->sk_reuseport)
250 if (rcu_access_pointer(sk->sk_reuseport_cb))
252 if (!uid_eq(tb->fastuid, uid))
254 /* We only need to check the rcv_saddr if this tb was once marked
255 * without fastreuseport and then was reset, as we can only know that
256 * the fast_*rcv_saddr doesn't have any conflicts with the socks on the
259 if (tb->fastreuseport == FASTREUSEPORT_ANY)
261 #if IS_ENABLED(CONFIG_IPV6)
262 if (tb->fast_sk_family == AF_INET6)
263 return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
268 ipv6_only_sock(sk), true);
270 return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
271 ipv6_only_sock(sk), true);
274 /* Obtain a reference to a local port for the given sock,
275 * if snum is zero it means select any available local port.
276 * We try to allocate an odd port (and leave even ports for connect())
278 int inet_csk_get_port(struct sock *sk, unsigned short snum)
280 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
281 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
282 int ret = 1, port = snum;
283 struct inet_bind_hashbucket *head;
284 struct net *net = sock_net(sk);
285 struct inet_bind_bucket *tb = NULL;
286 kuid_t uid = sock_i_uid(sk);
289 head = inet_csk_find_open_port(sk, &tb, &port);
296 head = &hinfo->bhash[inet_bhashfn(net, port,
298 spin_lock_bh(&head->lock);
299 inet_bind_bucket_for_each(tb, &head->chain)
300 if (net_eq(ib_net(tb), net) && tb->port == port)
303 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
308 if (!hlist_empty(&tb->owners)) {
309 if (sk->sk_reuse == SK_FORCE_REUSE)
312 if ((tb->fastreuse > 0 && reuse) ||
313 sk_reuseport_match(tb, sk))
315 if (inet_csk_bind_conflict(sk, tb, true, true))
319 if (hlist_empty(&tb->owners)) {
320 tb->fastreuse = reuse;
321 if (sk->sk_reuseport) {
322 tb->fastreuseport = FASTREUSEPORT_ANY;
324 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
325 tb->fast_ipv6_only = ipv6_only_sock(sk);
326 tb->fast_sk_family = sk->sk_family;
327 #if IS_ENABLED(CONFIG_IPV6)
328 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
331 tb->fastreuseport = 0;
336 if (sk->sk_reuseport) {
337 /* We didn't match or we don't have fastreuseport set on
338 * the tb, but we have sk_reuseport set on this socket
339 * and we know that there are no bind conflicts with
340 * this socket in this tb, so reset our tb's reuseport
341 * settings so that any subsequent sockets that match
342 * our current socket will be put on the fast path.
344 * If we reset we need to set FASTREUSEPORT_STRICT so we
345 * do extra checking for all subsequent sk_reuseport
348 if (!sk_reuseport_match(tb, sk)) {
349 tb->fastreuseport = FASTREUSEPORT_STRICT;
351 tb->fast_rcv_saddr = sk->sk_rcv_saddr;
352 tb->fast_ipv6_only = ipv6_only_sock(sk);
353 tb->fast_sk_family = sk->sk_family;
354 #if IS_ENABLED(CONFIG_IPV6)
355 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
359 tb->fastreuseport = 0;
362 if (!inet_csk(sk)->icsk_bind_hash)
363 inet_bind_hash(sk, tb, port);
364 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
368 spin_unlock_bh(&head->lock);
371 EXPORT_SYMBOL_GPL(inet_csk_get_port);
374 * Wait for an incoming connection, avoid race conditions. This must be called
375 * with the socket locked.
377 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
379 struct inet_connection_sock *icsk = inet_csk(sk);
384 * True wake-one mechanism for incoming connections: only
385 * one process gets woken up, not the 'whole herd'.
386 * Since we do not 'race & poll' for established sockets
387 * anymore, the common case will execute the loop only once.
389 * Subtle issue: "add_wait_queue_exclusive()" will be added
390 * after any current non-exclusive waiters, and we know that
391 * it will always _stay_ after any new non-exclusive waiters
392 * because all non-exclusive waiters are added at the
393 * beginning of the wait-queue. As such, it's ok to "drop"
394 * our exclusiveness temporarily when we get woken up without
395 * having to remove and re-insert us on the wait queue.
398 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
401 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
402 timeo = schedule_timeout(timeo);
403 sched_annotate_sleep();
406 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
409 if (sk->sk_state != TCP_LISTEN)
411 err = sock_intr_errno(timeo);
412 if (signal_pending(current))
418 finish_wait(sk_sleep(sk), &wait);
423 * This will accept the next outstanding connection.
425 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
427 struct inet_connection_sock *icsk = inet_csk(sk);
428 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
429 struct request_sock *req;
435 /* We need to make sure that this socket is listening,
436 * and that it has something pending.
439 if (sk->sk_state != TCP_LISTEN)
442 /* Find already established connection */
443 if (reqsk_queue_empty(queue)) {
444 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
446 /* If this is a non blocking socket don't sleep */
451 error = inet_csk_wait_for_connect(sk, timeo);
455 req = reqsk_queue_remove(queue, sk);
458 if (sk->sk_protocol == IPPROTO_TCP &&
459 tcp_rsk(req)->tfo_listener) {
460 spin_lock_bh(&queue->fastopenq.lock);
461 if (tcp_rsk(req)->tfo_listener) {
462 /* We are still waiting for the final ACK from 3WHS
463 * so can't free req now. Instead, we set req->sk to
464 * NULL to signify that the child socket is taken
465 * so reqsk_fastopen_remove() will free the req
466 * when 3WHS finishes (or is aborted).
471 spin_unlock_bh(&queue->fastopenq.lock);
484 EXPORT_SYMBOL(inet_csk_accept);
487 * Using different timers for retransmit, delayed acks and probes
488 * We may wish use just one timer maintaining a list of expire jiffies
491 void inet_csk_init_xmit_timers(struct sock *sk,
492 void (*retransmit_handler)(struct timer_list *t),
493 void (*delack_handler)(struct timer_list *t),
494 void (*keepalive_handler)(struct timer_list *t))
496 struct inet_connection_sock *icsk = inet_csk(sk);
498 timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);
499 timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);
500 timer_setup(&sk->sk_timer, keepalive_handler, 0);
501 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
503 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
505 void inet_csk_clear_xmit_timers(struct sock *sk)
507 struct inet_connection_sock *icsk = inet_csk(sk);
509 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
511 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
512 sk_stop_timer(sk, &icsk->icsk_delack_timer);
513 sk_stop_timer(sk, &sk->sk_timer);
515 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
517 void inet_csk_delete_keepalive_timer(struct sock *sk)
519 sk_stop_timer(sk, &sk->sk_timer);
521 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
523 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
525 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
527 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
529 struct dst_entry *inet_csk_route_req(const struct sock *sk,
531 const struct request_sock *req)
533 const struct inet_request_sock *ireq = inet_rsk(req);
534 struct net *net = read_pnet(&ireq->ireq_net);
535 struct ip_options_rcu *opt;
538 opt = ireq_opt_deref(ireq);
540 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
541 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
542 sk->sk_protocol, inet_sk_flowi_flags(sk),
543 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
544 ireq->ir_loc_addr, ireq->ir_rmt_port,
545 htons(ireq->ir_num), sk->sk_uid);
546 security_req_classify_flow(req, flowi4_to_flowi(fl4));
547 rt = ip_route_output_flow(net, fl4, sk);
550 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
557 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
560 EXPORT_SYMBOL_GPL(inet_csk_route_req);
562 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
564 const struct request_sock *req)
566 const struct inet_request_sock *ireq = inet_rsk(req);
567 struct net *net = read_pnet(&ireq->ireq_net);
568 struct inet_sock *newinet = inet_sk(newsk);
569 struct ip_options_rcu *opt;
573 opt = rcu_dereference(ireq->ireq_opt);
574 fl4 = &newinet->cork.fl.u.ip4;
576 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
577 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
578 sk->sk_protocol, inet_sk_flowi_flags(sk),
579 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
580 ireq->ir_loc_addr, ireq->ir_rmt_port,
581 htons(ireq->ir_num), sk->sk_uid);
582 security_req_classify_flow(req, flowi4_to_flowi(fl4));
583 rt = ip_route_output_flow(net, fl4, sk);
586 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
593 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
596 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
598 #if IS_ENABLED(CONFIG_IPV6)
599 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
601 #define AF_INET_FAMILY(fam) true
604 /* Decide when to expire the request and when to resend SYN-ACK */
605 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
606 const int max_retries,
607 const u8 rskq_defer_accept,
608 int *expire, int *resend)
610 if (!rskq_defer_accept) {
611 *expire = req->num_timeout >= thresh;
615 *expire = req->num_timeout >= thresh &&
616 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
618 * Do not resend while waiting for data after ACK,
619 * start to resend on end of deferring period to give
620 * last chance for data or ACK to create established socket.
622 *resend = !inet_rsk(req)->acked ||
623 req->num_timeout >= rskq_defer_accept - 1;
626 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
628 int err = req->rsk_ops->rtx_syn_ack(parent, req);
634 EXPORT_SYMBOL(inet_rtx_syn_ack);
636 /* return true if req was found in the ehash table */
637 static bool reqsk_queue_unlink(struct request_sock_queue *queue,
638 struct request_sock *req)
640 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
643 if (sk_hashed(req_to_sk(req))) {
644 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
647 found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
650 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
655 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
657 if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
658 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
662 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
664 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
666 inet_csk_reqsk_queue_drop(sk, req);
669 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
671 static void reqsk_timer_handler(struct timer_list *t)
673 struct request_sock *req = from_timer(req, t, rsk_timer);
674 struct sock *sk_listener = req->rsk_listener;
675 struct net *net = sock_net(sk_listener);
676 struct inet_connection_sock *icsk = inet_csk(sk_listener);
677 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
678 int qlen, expire = 0, resend = 0;
679 int max_retries, thresh;
682 if (inet_sk_state_load(sk_listener) != TCP_LISTEN)
685 max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
686 thresh = max_retries;
687 /* Normally all the openreqs are young and become mature
688 * (i.e. converted to established socket) for first timeout.
689 * If synack was not acknowledged for 1 second, it means
690 * one of the following things: synack was lost, ack was lost,
691 * rtt is high or nobody planned to ack (i.e. synflood).
692 * When server is a bit loaded, queue is populated with old
693 * open requests, reducing effective size of queue.
694 * When server is well loaded, queue size reduces to zero
695 * after several minutes of work. It is not synflood,
696 * it is normal operation. The solution is pruning
697 * too old entries overriding normal timeout, when
698 * situation becomes dangerous.
700 * Essentially, we reserve half of room for young
701 * embrions; and abort old ones without pity, if old
702 * ones are about to clog our table.
704 qlen = reqsk_queue_len(queue);
705 if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
706 int young = reqsk_queue_len_young(queue) << 1;
715 defer_accept = READ_ONCE(queue->rskq_defer_accept);
717 max_retries = defer_accept;
718 syn_ack_recalc(req, thresh, max_retries, defer_accept,
720 req->rsk_ops->syn_ack_timeout(req);
723 !inet_rtx_syn_ack(sk_listener, req) ||
724 inet_rsk(req)->acked)) {
727 if (req->num_timeout++ == 0)
728 atomic_dec(&queue->young);
729 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
730 mod_timer(&req->rsk_timer, jiffies + timeo);
734 inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
737 static void reqsk_queue_hash_req(struct request_sock *req,
738 unsigned long timeout)
740 req->num_retrans = 0;
741 req->num_timeout = 0;
744 timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
745 mod_timer(&req->rsk_timer, jiffies + timeout);
747 inet_ehash_insert(req_to_sk(req), NULL);
748 /* before letting lookups find us, make sure all req fields
749 * are committed to memory and refcnt initialized.
752 refcount_set(&req->rsk_refcnt, 2 + 1);
755 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
756 unsigned long timeout)
758 reqsk_queue_hash_req(req, timeout);
759 inet_csk_reqsk_queue_added(sk);
761 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
764 * inet_csk_clone_lock - clone an inet socket, and lock its clone
765 * @sk: the socket to clone
767 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
769 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
771 struct sock *inet_csk_clone_lock(const struct sock *sk,
772 const struct request_sock *req,
773 const gfp_t priority)
775 struct sock *newsk = sk_clone_lock(sk, priority);
778 struct inet_connection_sock *newicsk = inet_csk(newsk);
780 inet_sk_set_state(newsk, TCP_SYN_RECV);
781 newicsk->icsk_bind_hash = NULL;
783 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
784 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
785 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
787 /* listeners have SOCK_RCU_FREE, not the children */
788 sock_reset_flag(newsk, SOCK_RCU_FREE);
790 inet_sk(newsk)->mc_list = NULL;
792 newsk->sk_mark = inet_rsk(req)->ir_mark;
793 atomic64_set(&newsk->sk_cookie,
794 atomic64_read(&inet_rsk(req)->ir_cookie));
796 newicsk->icsk_retransmits = 0;
797 newicsk->icsk_backoff = 0;
798 newicsk->icsk_probes_out = 0;
800 /* Deinitialize accept_queue to trap illegal accesses. */
801 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
803 security_inet_csk_clone(newsk, req);
807 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
810 * At this point, there should be no process reference to this
811 * socket, and thus no user references at all. Therefore we
812 * can assume the socket waitqueue is inactive and nobody will
813 * try to jump onto it.
815 void inet_csk_destroy_sock(struct sock *sk)
817 WARN_ON(sk->sk_state != TCP_CLOSE);
818 WARN_ON(!sock_flag(sk, SOCK_DEAD));
820 /* It cannot be in hash table! */
821 WARN_ON(!sk_unhashed(sk));
823 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
824 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
826 sk->sk_prot->destroy(sk);
828 sk_stream_kill_queues(sk);
830 xfrm_sk_free_policy(sk);
832 sk_refcnt_debug_release(sk);
834 percpu_counter_dec(sk->sk_prot->orphan_count);
838 EXPORT_SYMBOL(inet_csk_destroy_sock);
840 /* This function allows to force a closure of a socket after the call to
841 * tcp/dccp_create_openreq_child().
843 void inet_csk_prepare_forced_close(struct sock *sk)
844 __releases(&sk->sk_lock.slock)
846 /* sk_clone_lock locked the socket and set refcnt to 2 */
850 /* The below has to be done to allow calling inet_csk_destroy_sock */
851 sock_set_flag(sk, SOCK_DEAD);
852 percpu_counter_inc(sk->sk_prot->orphan_count);
853 inet_sk(sk)->inet_num = 0;
855 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
857 int inet_csk_listen_start(struct sock *sk, int backlog)
859 struct inet_connection_sock *icsk = inet_csk(sk);
860 struct inet_sock *inet = inet_sk(sk);
861 int err = -EADDRINUSE;
863 reqsk_queue_alloc(&icsk->icsk_accept_queue);
865 sk->sk_max_ack_backlog = backlog;
866 sk->sk_ack_backlog = 0;
867 inet_csk_delack_init(sk);
869 /* There is race window here: we announce ourselves listening,
870 * but this transition is still not validated by get_port().
871 * It is OK, because this socket enters to hash table only
872 * after validation is complete.
874 inet_sk_state_store(sk, TCP_LISTEN);
875 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
876 inet->inet_sport = htons(inet->inet_num);
879 err = sk->sk_prot->hash(sk);
885 inet_sk_set_state(sk, TCP_CLOSE);
888 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
890 static void inet_child_forget(struct sock *sk, struct request_sock *req,
893 sk->sk_prot->disconnect(child, O_NONBLOCK);
897 percpu_counter_inc(sk->sk_prot->orphan_count);
899 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
900 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
901 BUG_ON(sk != req->rsk_listener);
903 /* Paranoid, to prevent race condition if
904 * an inbound pkt destined for child is
905 * blocked by sock lock in tcp_v4_rcv().
906 * Also to satisfy an assertion in
907 * tcp_v4_destroy_sock().
909 tcp_sk(child)->fastopen_rsk = NULL;
911 inet_csk_destroy_sock(child);
914 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
915 struct request_sock *req,
918 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
920 spin_lock(&queue->rskq_lock);
921 if (unlikely(sk->sk_state != TCP_LISTEN)) {
922 inet_child_forget(sk, req, child);
927 if (queue->rskq_accept_head == NULL)
928 queue->rskq_accept_head = req;
930 queue->rskq_accept_tail->dl_next = req;
931 queue->rskq_accept_tail = req;
932 sk_acceptq_added(sk);
934 spin_unlock(&queue->rskq_lock);
937 EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
939 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
940 struct request_sock *req, bool own_req)
943 inet_csk_reqsk_queue_drop(sk, req);
944 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
945 if (inet_csk_reqsk_queue_add(sk, req, child))
948 /* Too bad, another child took ownership of the request, undo. */
949 bh_unlock_sock(child);
953 EXPORT_SYMBOL(inet_csk_complete_hashdance);
956 * This routine closes sockets which have been at least partially
957 * opened, but not yet accepted.
959 void inet_csk_listen_stop(struct sock *sk)
961 struct inet_connection_sock *icsk = inet_csk(sk);
962 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
963 struct request_sock *next, *req;
965 /* Following specs, it would be better either to send FIN
966 * (and enter FIN-WAIT-1, it is normal close)
967 * or to send active reset (abort).
968 * Certainly, it is pretty dangerous while synflood, but it is
969 * bad justification for our negligence 8)
970 * To be honest, we are not able to make either
971 * of the variants now. --ANK
973 while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
974 struct sock *child = req->sk;
978 WARN_ON(sock_owned_by_user(child));
981 inet_child_forget(sk, req, child);
983 bh_unlock_sock(child);
989 if (queue->fastopenq.rskq_rst_head) {
990 /* Free all the reqs queued in rskq_rst_head. */
991 spin_lock_bh(&queue->fastopenq.lock);
992 req = queue->fastopenq.rskq_rst_head;
993 queue->fastopenq.rskq_rst_head = NULL;
994 spin_unlock_bh(&queue->fastopenq.lock);
995 while (req != NULL) {
1001 WARN_ON_ONCE(sk->sk_ack_backlog);
1003 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
1005 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
1007 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
1008 const struct inet_sock *inet = inet_sk(sk);
1010 sin->sin_family = AF_INET;
1011 sin->sin_addr.s_addr = inet->inet_daddr;
1012 sin->sin_port = inet->inet_dport;
1014 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
1016 #ifdef CONFIG_COMPAT
1017 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
1018 char __user *optval, int __user *optlen)
1020 const struct inet_connection_sock *icsk = inet_csk(sk);
1022 if (icsk->icsk_af_ops->compat_getsockopt)
1023 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
1025 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
1028 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
1030 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
1031 char __user *optval, unsigned int optlen)
1033 const struct inet_connection_sock *icsk = inet_csk(sk);
1035 if (icsk->icsk_af_ops->compat_setsockopt)
1036 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
1038 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
1041 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
1044 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
1046 const struct inet_sock *inet = inet_sk(sk);
1047 const struct ip_options_rcu *inet_opt;
1048 __be32 daddr = inet->inet_daddr;
1053 inet_opt = rcu_dereference(inet->inet_opt);
1054 if (inet_opt && inet_opt->opt.srr)
1055 daddr = inet_opt->opt.faddr;
1057 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
1058 inet->inet_saddr, inet->inet_dport,
1059 inet->inet_sport, sk->sk_protocol,
1060 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
1064 sk_setup_caps(sk, &rt->dst);
1070 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
1072 struct dst_entry *dst = __sk_dst_check(sk, 0);
1073 struct inet_sock *inet = inet_sk(sk);
1076 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1080 dst->ops->update_pmtu(dst, sk, NULL, mtu);
1082 dst = __sk_dst_check(sk, 0);
1084 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
1088 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);