1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
7 * Support for INET connection oriented protocols.
9 * Authors: See the TCP sources
12 #include <linux/module.h>
13 #include <linux/jhash.h>
15 #include <net/inet_connection_sock.h>
16 #include <net/inet_hashtables.h>
17 #include <net/inet_timewait_sock.h>
19 #include <net/route.h>
20 #include <net/tcp_states.h>
23 #include <net/sock_reuseport.h>
24 #include <net/addrconf.h>
26 #if IS_ENABLED(CONFIG_IPV6)
27 /* match_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
28 * only, and any IPv4 addresses if not IPv6 only
29 * match_wildcard == false: addresses must be exactly the same, i.e.
30 * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
31 * and 0.0.0.0 equals to 0.0.0.0 only
33 static bool ipv6_rcv_saddr_equal(const struct in6_addr
*sk1_rcv_saddr6
,
34 const struct in6_addr
*sk2_rcv_saddr6
,
35 __be32 sk1_rcv_saddr
, __be32 sk2_rcv_saddr
,
36 bool sk1_ipv6only
, bool sk2_ipv6only
,
39 int addr_type
= ipv6_addr_type(sk1_rcv_saddr6
);
40 int addr_type2
= sk2_rcv_saddr6
? ipv6_addr_type(sk2_rcv_saddr6
) : IPV6_ADDR_MAPPED
;
42 /* if both are mapped, treat as IPv4 */
43 if (addr_type
== IPV6_ADDR_MAPPED
&& addr_type2
== IPV6_ADDR_MAPPED
) {
45 if (sk1_rcv_saddr
== sk2_rcv_saddr
)
47 if (!sk1_rcv_saddr
|| !sk2_rcv_saddr
)
48 return match_wildcard
;
53 if (addr_type
== IPV6_ADDR_ANY
&& addr_type2
== IPV6_ADDR_ANY
)
56 if (addr_type2
== IPV6_ADDR_ANY
&& match_wildcard
&&
57 !(sk2_ipv6only
&& addr_type
== IPV6_ADDR_MAPPED
))
60 if (addr_type
== IPV6_ADDR_ANY
&& match_wildcard
&&
61 !(sk1_ipv6only
&& addr_type2
== IPV6_ADDR_MAPPED
))
65 ipv6_addr_equal(sk1_rcv_saddr6
, sk2_rcv_saddr6
))
72 /* match_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
73 * match_wildcard == false: addresses must be exactly the same, i.e.
74 * 0.0.0.0 only equals to 0.0.0.0
76 static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr
, __be32 sk2_rcv_saddr
,
77 bool sk2_ipv6only
, bool match_wildcard
)
80 if (sk1_rcv_saddr
== sk2_rcv_saddr
)
82 if (!sk1_rcv_saddr
|| !sk2_rcv_saddr
)
83 return match_wildcard
;
88 bool inet_rcv_saddr_equal(const struct sock
*sk
, const struct sock
*sk2
,
91 #if IS_ENABLED(CONFIG_IPV6)
92 if (sk
->sk_family
== AF_INET6
)
93 return ipv6_rcv_saddr_equal(&sk
->sk_v6_rcv_saddr
,
101 return ipv4_rcv_saddr_equal(sk
->sk_rcv_saddr
, sk2
->sk_rcv_saddr
,
102 ipv6_only_sock(sk2
), match_wildcard
);
104 EXPORT_SYMBOL(inet_rcv_saddr_equal
);
106 bool inet_rcv_saddr_any(const struct sock
*sk
)
108 #if IS_ENABLED(CONFIG_IPV6)
109 if (sk
->sk_family
== AF_INET6
)
110 return ipv6_addr_any(&sk
->sk_v6_rcv_saddr
);
112 return !sk
->sk_rcv_saddr
;
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
;
184 l3mdev
= inet_sk_bound_l3mdev(sk
);
185 attempt_half
= (sk
->sk_reuse
== SK_CAN_REUSE
) ? 1 : 0;
187 inet_get_local_port_range(net
, &low
, &high
);
188 high
++; /* [32768, 60999] -> [32768, 61000[ */
192 int half
= low
+ (((high
- low
) >> 2) << 1);
194 if (attempt_half
== 1)
199 remaining
= high
- low
;
200 if (likely(remaining
> 1))
203 offset
= prandom_u32() % remaining
;
204 /* __inet_hash_connect() favors ports having @low parity
205 * We do the opposite to not pollute connect() users.
211 for (i
= 0; i
< remaining
; i
+= 2, port
+= 2) {
212 if (unlikely(port
>= high
))
214 if (inet_is_local_reserved_port(net
, port
))
216 head
= &hinfo
->bhash
[inet_bhashfn(net
, port
,
218 spin_lock_bh(&head
->lock
);
219 inet_bind_bucket_for_each(tb
, &head
->chain
)
220 if (net_eq(ib_net(tb
), net
) && tb
->l3mdev
== l3mdev
&&
222 if (!inet_csk_bind_conflict(sk
, tb
, false, false))
229 spin_unlock_bh(&head
->lock
);
235 goto other_parity_scan
;
237 if (attempt_half
== 1) {
238 /* OK we now try the upper half of the range */
240 goto other_half_scan
;
249 static inline int sk_reuseport_match(struct inet_bind_bucket
*tb
,
252 kuid_t uid
= sock_i_uid(sk
);
254 if (tb
->fastreuseport
<= 0)
256 if (!sk
->sk_reuseport
)
258 if (rcu_access_pointer(sk
->sk_reuseport_cb
))
260 if (!uid_eq(tb
->fastuid
, uid
))
262 /* We only need to check the rcv_saddr if this tb was once marked
263 * without fastreuseport and then was reset, as we can only know that
264 * the fast_*rcv_saddr doesn't have any conflicts with the socks on the
267 if (tb
->fastreuseport
== FASTREUSEPORT_ANY
)
269 #if IS_ENABLED(CONFIG_IPV6)
270 if (tb
->fast_sk_family
== AF_INET6
)
271 return ipv6_rcv_saddr_equal(&tb
->fast_v6_rcv_saddr
,
276 ipv6_only_sock(sk
), true);
278 return ipv4_rcv_saddr_equal(tb
->fast_rcv_saddr
, sk
->sk_rcv_saddr
,
279 ipv6_only_sock(sk
), true);
282 /* Obtain a reference to a local port for the given sock,
283 * if snum is zero it means select any available local port.
284 * We try to allocate an odd port (and leave even ports for connect())
286 int inet_csk_get_port(struct sock
*sk
, unsigned short snum
)
288 bool reuse
= sk
->sk_reuse
&& sk
->sk_state
!= TCP_LISTEN
;
289 struct inet_hashinfo
*hinfo
= sk
->sk_prot
->h
.hashinfo
;
290 int ret
= 1, port
= snum
;
291 struct inet_bind_hashbucket
*head
;
292 struct net
*net
= sock_net(sk
);
293 struct inet_bind_bucket
*tb
= NULL
;
294 kuid_t uid
= sock_i_uid(sk
);
297 l3mdev
= inet_sk_bound_l3mdev(sk
);
300 head
= inet_csk_find_open_port(sk
, &tb
, &port
);
307 head
= &hinfo
->bhash
[inet_bhashfn(net
, port
,
309 spin_lock_bh(&head
->lock
);
310 inet_bind_bucket_for_each(tb
, &head
->chain
)
311 if (net_eq(ib_net(tb
), net
) && tb
->l3mdev
== l3mdev
&&
315 tb
= inet_bind_bucket_create(hinfo
->bind_bucket_cachep
,
316 net
, head
, port
, l3mdev
);
320 if (!hlist_empty(&tb
->owners
)) {
321 if (sk
->sk_reuse
== SK_FORCE_REUSE
)
324 if ((tb
->fastreuse
> 0 && reuse
) ||
325 sk_reuseport_match(tb
, sk
))
327 if (inet_csk_bind_conflict(sk
, tb
, true, true))
331 if (hlist_empty(&tb
->owners
)) {
332 tb
->fastreuse
= reuse
;
333 if (sk
->sk_reuseport
) {
334 tb
->fastreuseport
= FASTREUSEPORT_ANY
;
336 tb
->fast_rcv_saddr
= sk
->sk_rcv_saddr
;
337 tb
->fast_ipv6_only
= ipv6_only_sock(sk
);
338 tb
->fast_sk_family
= sk
->sk_family
;
339 #if IS_ENABLED(CONFIG_IPV6)
340 tb
->fast_v6_rcv_saddr
= sk
->sk_v6_rcv_saddr
;
343 tb
->fastreuseport
= 0;
348 if (sk
->sk_reuseport
) {
349 /* We didn't match or we don't have fastreuseport set on
350 * the tb, but we have sk_reuseport set on this socket
351 * and we know that there are no bind conflicts with
352 * this socket in this tb, so reset our tb's reuseport
353 * settings so that any subsequent sockets that match
354 * our current socket will be put on the fast path.
356 * If we reset we need to set FASTREUSEPORT_STRICT so we
357 * do extra checking for all subsequent sk_reuseport
360 if (!sk_reuseport_match(tb
, sk
)) {
361 tb
->fastreuseport
= FASTREUSEPORT_STRICT
;
363 tb
->fast_rcv_saddr
= sk
->sk_rcv_saddr
;
364 tb
->fast_ipv6_only
= ipv6_only_sock(sk
);
365 tb
->fast_sk_family
= sk
->sk_family
;
366 #if IS_ENABLED(CONFIG_IPV6)
367 tb
->fast_v6_rcv_saddr
= sk
->sk_v6_rcv_saddr
;
371 tb
->fastreuseport
= 0;
374 if (!inet_csk(sk
)->icsk_bind_hash
)
375 inet_bind_hash(sk
, tb
, port
);
376 WARN_ON(inet_csk(sk
)->icsk_bind_hash
!= tb
);
380 spin_unlock_bh(&head
->lock
);
383 EXPORT_SYMBOL_GPL(inet_csk_get_port
);
386 * Wait for an incoming connection, avoid race conditions. This must be called
387 * with the socket locked.
389 static int inet_csk_wait_for_connect(struct sock
*sk
, long timeo
)
391 struct inet_connection_sock
*icsk
= inet_csk(sk
);
396 * True wake-one mechanism for incoming connections: only
397 * one process gets woken up, not the 'whole herd'.
398 * Since we do not 'race & poll' for established sockets
399 * anymore, the common case will execute the loop only once.
401 * Subtle issue: "add_wait_queue_exclusive()" will be added
402 * after any current non-exclusive waiters, and we know that
403 * it will always _stay_ after any new non-exclusive waiters
404 * because all non-exclusive waiters are added at the
405 * beginning of the wait-queue. As such, it's ok to "drop"
406 * our exclusiveness temporarily when we get woken up without
407 * having to remove and re-insert us on the wait queue.
410 prepare_to_wait_exclusive(sk_sleep(sk
), &wait
,
413 if (reqsk_queue_empty(&icsk
->icsk_accept_queue
))
414 timeo
= schedule_timeout(timeo
);
415 sched_annotate_sleep();
418 if (!reqsk_queue_empty(&icsk
->icsk_accept_queue
))
421 if (sk
->sk_state
!= TCP_LISTEN
)
423 err
= sock_intr_errno(timeo
);
424 if (signal_pending(current
))
430 finish_wait(sk_sleep(sk
), &wait
);
435 * This will accept the next outstanding connection.
437 struct sock
*inet_csk_accept(struct sock
*sk
, int flags
, int *err
, bool kern
)
439 struct inet_connection_sock
*icsk
= inet_csk(sk
);
440 struct request_sock_queue
*queue
= &icsk
->icsk_accept_queue
;
441 struct request_sock
*req
;
447 /* We need to make sure that this socket is listening,
448 * and that it has something pending.
451 if (sk
->sk_state
!= TCP_LISTEN
)
454 /* Find already established connection */
455 if (reqsk_queue_empty(queue
)) {
456 long timeo
= sock_rcvtimeo(sk
, flags
& O_NONBLOCK
);
458 /* If this is a non blocking socket don't sleep */
463 error
= inet_csk_wait_for_connect(sk
, timeo
);
467 req
= reqsk_queue_remove(queue
, sk
);
470 if (sk
->sk_protocol
== IPPROTO_TCP
&&
471 tcp_rsk(req
)->tfo_listener
) {
472 spin_lock_bh(&queue
->fastopenq
.lock
);
473 if (tcp_rsk(req
)->tfo_listener
) {
474 /* We are still waiting for the final ACK from 3WHS
475 * so can't free req now. Instead, we set req->sk to
476 * NULL to signify that the child socket is taken
477 * so reqsk_fastopen_remove() will free the req
478 * when 3WHS finishes (or is aborted).
483 spin_unlock_bh(&queue
->fastopenq
.lock
);
496 EXPORT_SYMBOL(inet_csk_accept
);
499 * Using different timers for retransmit, delayed acks and probes
500 * We may wish use just one timer maintaining a list of expire jiffies
503 void inet_csk_init_xmit_timers(struct sock
*sk
,
504 void (*retransmit_handler
)(struct timer_list
*t
),
505 void (*delack_handler
)(struct timer_list
*t
),
506 void (*keepalive_handler
)(struct timer_list
*t
))
508 struct inet_connection_sock
*icsk
= inet_csk(sk
);
510 timer_setup(&icsk
->icsk_retransmit_timer
, retransmit_handler
, 0);
511 timer_setup(&icsk
->icsk_delack_timer
, delack_handler
, 0);
512 timer_setup(&sk
->sk_timer
, keepalive_handler
, 0);
513 icsk
->icsk_pending
= icsk
->icsk_ack
.pending
= 0;
515 EXPORT_SYMBOL(inet_csk_init_xmit_timers
);
517 void inet_csk_clear_xmit_timers(struct sock
*sk
)
519 struct inet_connection_sock
*icsk
= inet_csk(sk
);
521 icsk
->icsk_pending
= icsk
->icsk_ack
.pending
= icsk
->icsk_ack
.blocked
= 0;
523 sk_stop_timer(sk
, &icsk
->icsk_retransmit_timer
);
524 sk_stop_timer(sk
, &icsk
->icsk_delack_timer
);
525 sk_stop_timer(sk
, &sk
->sk_timer
);
527 EXPORT_SYMBOL(inet_csk_clear_xmit_timers
);
529 void inet_csk_delete_keepalive_timer(struct sock
*sk
)
531 sk_stop_timer(sk
, &sk
->sk_timer
);
533 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer
);
535 void inet_csk_reset_keepalive_timer(struct sock
*sk
, unsigned long len
)
537 sk_reset_timer(sk
, &sk
->sk_timer
, jiffies
+ len
);
539 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer
);
541 struct dst_entry
*inet_csk_route_req(const struct sock
*sk
,
543 const struct request_sock
*req
)
545 const struct inet_request_sock
*ireq
= inet_rsk(req
);
546 struct net
*net
= read_pnet(&ireq
->ireq_net
);
547 struct ip_options_rcu
*opt
;
551 opt
= rcu_dereference(ireq
->ireq_opt
);
553 flowi4_init_output(fl4
, ireq
->ir_iif
, ireq
->ir_mark
,
554 RT_CONN_FLAGS(sk
), RT_SCOPE_UNIVERSE
,
555 sk
->sk_protocol
, inet_sk_flowi_flags(sk
),
556 (opt
&& opt
->opt
.srr
) ? opt
->opt
.faddr
: ireq
->ir_rmt_addr
,
557 ireq
->ir_loc_addr
, ireq
->ir_rmt_port
,
558 htons(ireq
->ir_num
), sk
->sk_uid
);
559 security_req_classify_flow(req
, flowi4_to_flowi(fl4
));
560 rt
= ip_route_output_flow(net
, fl4
, sk
);
563 if (opt
&& opt
->opt
.is_strictroute
&& rt
->rt_uses_gateway
)
572 __IP_INC_STATS(net
, IPSTATS_MIB_OUTNOROUTES
);
575 EXPORT_SYMBOL_GPL(inet_csk_route_req
);
577 struct dst_entry
*inet_csk_route_child_sock(const struct sock
*sk
,
579 const struct request_sock
*req
)
581 const struct inet_request_sock
*ireq
= inet_rsk(req
);
582 struct net
*net
= read_pnet(&ireq
->ireq_net
);
583 struct inet_sock
*newinet
= inet_sk(newsk
);
584 struct ip_options_rcu
*opt
;
588 opt
= rcu_dereference(ireq
->ireq_opt
);
589 fl4
= &newinet
->cork
.fl
.u
.ip4
;
591 flowi4_init_output(fl4
, ireq
->ir_iif
, ireq
->ir_mark
,
592 RT_CONN_FLAGS(sk
), RT_SCOPE_UNIVERSE
,
593 sk
->sk_protocol
, inet_sk_flowi_flags(sk
),
594 (opt
&& opt
->opt
.srr
) ? opt
->opt
.faddr
: ireq
->ir_rmt_addr
,
595 ireq
->ir_loc_addr
, ireq
->ir_rmt_port
,
596 htons(ireq
->ir_num
), sk
->sk_uid
);
597 security_req_classify_flow(req
, flowi4_to_flowi(fl4
));
598 rt
= ip_route_output_flow(net
, fl4
, sk
);
601 if (opt
&& opt
->opt
.is_strictroute
&& rt
->rt_uses_gateway
)
608 __IP_INC_STATS(net
, IPSTATS_MIB_OUTNOROUTES
);
611 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock
);
613 #if IS_ENABLED(CONFIG_IPV6)
614 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
616 #define AF_INET_FAMILY(fam) true
619 /* Decide when to expire the request and when to resend SYN-ACK */
620 static inline void syn_ack_recalc(struct request_sock
*req
, const int thresh
,
621 const int max_retries
,
622 const u8 rskq_defer_accept
,
623 int *expire
, int *resend
)
625 if (!rskq_defer_accept
) {
626 *expire
= req
->num_timeout
>= thresh
;
630 *expire
= req
->num_timeout
>= thresh
&&
631 (!inet_rsk(req
)->acked
|| req
->num_timeout
>= max_retries
);
633 * Do not resend while waiting for data after ACK,
634 * start to resend on end of deferring period to give
635 * last chance for data or ACK to create established socket.
637 *resend
= !inet_rsk(req
)->acked
||
638 req
->num_timeout
>= rskq_defer_accept
- 1;
641 int inet_rtx_syn_ack(const struct sock
*parent
, struct request_sock
*req
)
643 int err
= req
->rsk_ops
->rtx_syn_ack(parent
, req
);
649 EXPORT_SYMBOL(inet_rtx_syn_ack
);
651 /* return true if req was found in the ehash table */
652 static bool reqsk_queue_unlink(struct request_sock
*req
)
654 struct inet_hashinfo
*hashinfo
= req_to_sk(req
)->sk_prot
->h
.hashinfo
;
657 if (sk_hashed(req_to_sk(req
))) {
658 spinlock_t
*lock
= inet_ehash_lockp(hashinfo
, req
->rsk_hash
);
661 found
= __sk_nulls_del_node_init_rcu(req_to_sk(req
));
664 if (timer_pending(&req
->rsk_timer
) && del_timer_sync(&req
->rsk_timer
))
669 void inet_csk_reqsk_queue_drop(struct sock
*sk
, struct request_sock
*req
)
671 if (reqsk_queue_unlink(req
)) {
672 reqsk_queue_removed(&inet_csk(sk
)->icsk_accept_queue
, req
);
676 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop
);
678 void inet_csk_reqsk_queue_drop_and_put(struct sock
*sk
, struct request_sock
*req
)
680 inet_csk_reqsk_queue_drop(sk
, req
);
683 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put
);
685 static void reqsk_timer_handler(struct timer_list
*t
)
687 struct request_sock
*req
= from_timer(req
, t
, rsk_timer
);
688 struct sock
*sk_listener
= req
->rsk_listener
;
689 struct net
*net
= sock_net(sk_listener
);
690 struct inet_connection_sock
*icsk
= inet_csk(sk_listener
);
691 struct request_sock_queue
*queue
= &icsk
->icsk_accept_queue
;
692 int qlen
, expire
= 0, resend
= 0;
693 int max_retries
, thresh
;
696 if (inet_sk_state_load(sk_listener
) != TCP_LISTEN
)
699 max_retries
= icsk
->icsk_syn_retries
? : net
->ipv4
.sysctl_tcp_synack_retries
;
700 thresh
= max_retries
;
701 /* Normally all the openreqs are young and become mature
702 * (i.e. converted to established socket) for first timeout.
703 * If synack was not acknowledged for 1 second, it means
704 * one of the following things: synack was lost, ack was lost,
705 * rtt is high or nobody planned to ack (i.e. synflood).
706 * When server is a bit loaded, queue is populated with old
707 * open requests, reducing effective size of queue.
708 * When server is well loaded, queue size reduces to zero
709 * after several minutes of work. It is not synflood,
710 * it is normal operation. The solution is pruning
711 * too old entries overriding normal timeout, when
712 * situation becomes dangerous.
714 * Essentially, we reserve half of room for young
715 * embrions; and abort old ones without pity, if old
716 * ones are about to clog our table.
718 qlen
= reqsk_queue_len(queue
);
719 if ((qlen
<< 1) > max(8U, sk_listener
->sk_max_ack_backlog
)) {
720 int young
= reqsk_queue_len_young(queue
) << 1;
729 defer_accept
= READ_ONCE(queue
->rskq_defer_accept
);
731 max_retries
= defer_accept
;
732 syn_ack_recalc(req
, thresh
, max_retries
, defer_accept
,
734 req
->rsk_ops
->syn_ack_timeout(req
);
737 !inet_rtx_syn_ack(sk_listener
, req
) ||
738 inet_rsk(req
)->acked
)) {
741 if (req
->num_timeout
++ == 0)
742 atomic_dec(&queue
->young
);
743 timeo
= min(TCP_TIMEOUT_INIT
<< req
->num_timeout
, TCP_RTO_MAX
);
744 mod_timer(&req
->rsk_timer
, jiffies
+ timeo
);
748 inet_csk_reqsk_queue_drop_and_put(sk_listener
, req
);
751 static void reqsk_queue_hash_req(struct request_sock
*req
,
752 unsigned long timeout
)
754 timer_setup(&req
->rsk_timer
, reqsk_timer_handler
, TIMER_PINNED
);
755 mod_timer(&req
->rsk_timer
, jiffies
+ timeout
);
757 inet_ehash_insert(req_to_sk(req
), NULL
);
758 /* before letting lookups find us, make sure all req fields
759 * are committed to memory and refcnt initialized.
762 refcount_set(&req
->rsk_refcnt
, 2 + 1);
765 void inet_csk_reqsk_queue_hash_add(struct sock
*sk
, struct request_sock
*req
,
766 unsigned long timeout
)
768 reqsk_queue_hash_req(req
, timeout
);
769 inet_csk_reqsk_queue_added(sk
);
771 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add
);
774 * inet_csk_clone_lock - clone an inet socket, and lock its clone
775 * @sk: the socket to clone
777 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
779 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
781 struct sock
*inet_csk_clone_lock(const struct sock
*sk
,
782 const struct request_sock
*req
,
783 const gfp_t priority
)
785 struct sock
*newsk
= sk_clone_lock(sk
, priority
);
788 struct inet_connection_sock
*newicsk
= inet_csk(newsk
);
790 inet_sk_set_state(newsk
, TCP_SYN_RECV
);
791 newicsk
->icsk_bind_hash
= NULL
;
793 inet_sk(newsk
)->inet_dport
= inet_rsk(req
)->ir_rmt_port
;
794 inet_sk(newsk
)->inet_num
= inet_rsk(req
)->ir_num
;
795 inet_sk(newsk
)->inet_sport
= htons(inet_rsk(req
)->ir_num
);
797 /* listeners have SOCK_RCU_FREE, not the children */
798 sock_reset_flag(newsk
, SOCK_RCU_FREE
);
800 inet_sk(newsk
)->mc_list
= NULL
;
802 newsk
->sk_mark
= inet_rsk(req
)->ir_mark
;
803 atomic64_set(&newsk
->sk_cookie
,
804 atomic64_read(&inet_rsk(req
)->ir_cookie
));
806 newicsk
->icsk_retransmits
= 0;
807 newicsk
->icsk_backoff
= 0;
808 newicsk
->icsk_probes_out
= 0;
810 /* Deinitialize accept_queue to trap illegal accesses. */
811 memset(&newicsk
->icsk_accept_queue
, 0, sizeof(newicsk
->icsk_accept_queue
));
813 security_inet_csk_clone(newsk
, req
);
817 EXPORT_SYMBOL_GPL(inet_csk_clone_lock
);
820 * At this point, there should be no process reference to this
821 * socket, and thus no user references at all. Therefore we
822 * can assume the socket waitqueue is inactive and nobody will
823 * try to jump onto it.
825 void inet_csk_destroy_sock(struct sock
*sk
)
827 WARN_ON(sk
->sk_state
!= TCP_CLOSE
);
828 WARN_ON(!sock_flag(sk
, SOCK_DEAD
));
830 /* It cannot be in hash table! */
831 WARN_ON(!sk_unhashed(sk
));
833 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
834 WARN_ON(inet_sk(sk
)->inet_num
&& !inet_csk(sk
)->icsk_bind_hash
);
836 sk
->sk_prot
->destroy(sk
);
838 sk_stream_kill_queues(sk
);
840 xfrm_sk_free_policy(sk
);
842 sk_refcnt_debug_release(sk
);
844 percpu_counter_dec(sk
->sk_prot
->orphan_count
);
848 EXPORT_SYMBOL(inet_csk_destroy_sock
);
850 /* This function allows to force a closure of a socket after the call to
851 * tcp/dccp_create_openreq_child().
853 void inet_csk_prepare_forced_close(struct sock
*sk
)
854 __releases(&sk
->sk_lock
.slock
)
856 /* sk_clone_lock locked the socket and set refcnt to 2 */
860 /* The below has to be done to allow calling inet_csk_destroy_sock */
861 sock_set_flag(sk
, SOCK_DEAD
);
862 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
863 inet_sk(sk
)->inet_num
= 0;
865 EXPORT_SYMBOL(inet_csk_prepare_forced_close
);
867 int inet_csk_listen_start(struct sock
*sk
, int backlog
)
869 struct inet_connection_sock
*icsk
= inet_csk(sk
);
870 struct inet_sock
*inet
= inet_sk(sk
);
871 int err
= -EADDRINUSE
;
873 reqsk_queue_alloc(&icsk
->icsk_accept_queue
);
875 sk
->sk_ack_backlog
= 0;
876 inet_csk_delack_init(sk
);
878 /* There is race window here: we announce ourselves listening,
879 * but this transition is still not validated by get_port().
880 * It is OK, because this socket enters to hash table only
881 * after validation is complete.
883 inet_sk_state_store(sk
, TCP_LISTEN
);
884 if (!sk
->sk_prot
->get_port(sk
, inet
->inet_num
)) {
885 inet
->inet_sport
= htons(inet
->inet_num
);
888 err
= sk
->sk_prot
->hash(sk
);
894 inet_sk_set_state(sk
, TCP_CLOSE
);
897 EXPORT_SYMBOL_GPL(inet_csk_listen_start
);
899 static void inet_child_forget(struct sock
*sk
, struct request_sock
*req
,
902 sk
->sk_prot
->disconnect(child
, O_NONBLOCK
);
906 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
908 if (sk
->sk_protocol
== IPPROTO_TCP
&& tcp_rsk(req
)->tfo_listener
) {
909 BUG_ON(rcu_access_pointer(tcp_sk(child
)->fastopen_rsk
) != req
);
910 BUG_ON(sk
!= req
->rsk_listener
);
912 /* Paranoid, to prevent race condition if
913 * an inbound pkt destined for child is
914 * blocked by sock lock in tcp_v4_rcv().
915 * Also to satisfy an assertion in
916 * tcp_v4_destroy_sock().
918 RCU_INIT_POINTER(tcp_sk(child
)->fastopen_rsk
, NULL
);
920 inet_csk_destroy_sock(child
);
923 struct sock
*inet_csk_reqsk_queue_add(struct sock
*sk
,
924 struct request_sock
*req
,
927 struct request_sock_queue
*queue
= &inet_csk(sk
)->icsk_accept_queue
;
929 spin_lock(&queue
->rskq_lock
);
930 if (unlikely(sk
->sk_state
!= TCP_LISTEN
)) {
931 inet_child_forget(sk
, req
, child
);
936 if (queue
->rskq_accept_head
== NULL
)
937 WRITE_ONCE(queue
->rskq_accept_head
, req
);
939 queue
->rskq_accept_tail
->dl_next
= req
;
940 queue
->rskq_accept_tail
= req
;
941 sk_acceptq_added(sk
);
943 spin_unlock(&queue
->rskq_lock
);
946 EXPORT_SYMBOL(inet_csk_reqsk_queue_add
);
948 struct sock
*inet_csk_complete_hashdance(struct sock
*sk
, struct sock
*child
,
949 struct request_sock
*req
, bool own_req
)
952 inet_csk_reqsk_queue_drop(sk
, req
);
953 reqsk_queue_removed(&inet_csk(sk
)->icsk_accept_queue
, req
);
954 if (inet_csk_reqsk_queue_add(sk
, req
, child
))
957 /* Too bad, another child took ownership of the request, undo. */
958 bh_unlock_sock(child
);
962 EXPORT_SYMBOL(inet_csk_complete_hashdance
);
965 * This routine closes sockets which have been at least partially
966 * opened, but not yet accepted.
968 void inet_csk_listen_stop(struct sock
*sk
)
970 struct inet_connection_sock
*icsk
= inet_csk(sk
);
971 struct request_sock_queue
*queue
= &icsk
->icsk_accept_queue
;
972 struct request_sock
*next
, *req
;
974 /* Following specs, it would be better either to send FIN
975 * (and enter FIN-WAIT-1, it is normal close)
976 * or to send active reset (abort).
977 * Certainly, it is pretty dangerous while synflood, but it is
978 * bad justification for our negligence 8)
979 * To be honest, we are not able to make either
980 * of the variants now. --ANK
982 while ((req
= reqsk_queue_remove(queue
, sk
)) != NULL
) {
983 struct sock
*child
= req
->sk
;
987 WARN_ON(sock_owned_by_user(child
));
990 inet_child_forget(sk
, req
, child
);
992 bh_unlock_sock(child
);
998 if (queue
->fastopenq
.rskq_rst_head
) {
999 /* Free all the reqs queued in rskq_rst_head. */
1000 spin_lock_bh(&queue
->fastopenq
.lock
);
1001 req
= queue
->fastopenq
.rskq_rst_head
;
1002 queue
->fastopenq
.rskq_rst_head
= NULL
;
1003 spin_unlock_bh(&queue
->fastopenq
.lock
);
1004 while (req
!= NULL
) {
1005 next
= req
->dl_next
;
1010 WARN_ON_ONCE(sk
->sk_ack_backlog
);
1012 EXPORT_SYMBOL_GPL(inet_csk_listen_stop
);
1014 void inet_csk_addr2sockaddr(struct sock
*sk
, struct sockaddr
*uaddr
)
1016 struct sockaddr_in
*sin
= (struct sockaddr_in
*)uaddr
;
1017 const struct inet_sock
*inet
= inet_sk(sk
);
1019 sin
->sin_family
= AF_INET
;
1020 sin
->sin_addr
.s_addr
= inet
->inet_daddr
;
1021 sin
->sin_port
= inet
->inet_dport
;
1023 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr
);
1025 #ifdef CONFIG_COMPAT
1026 int inet_csk_compat_getsockopt(struct sock
*sk
, int level
, int optname
,
1027 char __user
*optval
, int __user
*optlen
)
1029 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1031 if (icsk
->icsk_af_ops
->compat_getsockopt
)
1032 return icsk
->icsk_af_ops
->compat_getsockopt(sk
, level
, optname
,
1034 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
1037 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt
);
1039 int inet_csk_compat_setsockopt(struct sock
*sk
, int level
, int optname
,
1040 char __user
*optval
, unsigned int optlen
)
1042 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1044 if (icsk
->icsk_af_ops
->compat_setsockopt
)
1045 return icsk
->icsk_af_ops
->compat_setsockopt(sk
, level
, optname
,
1047 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
1050 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt
);
1053 static struct dst_entry
*inet_csk_rebuild_route(struct sock
*sk
, struct flowi
*fl
)
1055 const struct inet_sock
*inet
= inet_sk(sk
);
1056 const struct ip_options_rcu
*inet_opt
;
1057 __be32 daddr
= inet
->inet_daddr
;
1062 inet_opt
= rcu_dereference(inet
->inet_opt
);
1063 if (inet_opt
&& inet_opt
->opt
.srr
)
1064 daddr
= inet_opt
->opt
.faddr
;
1066 rt
= ip_route_output_ports(sock_net(sk
), fl4
, sk
, daddr
,
1067 inet
->inet_saddr
, inet
->inet_dport
,
1068 inet
->inet_sport
, sk
->sk_protocol
,
1069 RT_CONN_FLAGS(sk
), sk
->sk_bound_dev_if
);
1073 sk_setup_caps(sk
, &rt
->dst
);
1079 struct dst_entry
*inet_csk_update_pmtu(struct sock
*sk
, u32 mtu
)
1081 struct dst_entry
*dst
= __sk_dst_check(sk
, 0);
1082 struct inet_sock
*inet
= inet_sk(sk
);
1085 dst
= inet_csk_rebuild_route(sk
, &inet
->cork
.fl
);
1089 dst
->ops
->update_pmtu(dst
, sk
, NULL
, mtu
);
1091 dst
= __sk_dst_check(sk
, 0);
1093 dst
= inet_csk_rebuild_route(sk
, &inet
->cork
.fl
);
1097 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu
);