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 * Implementation of the Transmission Control Protocol(TCP).
8 * IPv4 specific functions
13 * linux/ipv4/tcp_input.c
14 * linux/ipv4/tcp_output.c
16 * See tcp.c for author information
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
26 * David S. Miller : New socket lookup architecture.
27 * This code is dedicated to John Dyson.
28 * David S. Miller : Change semantics of established hash,
29 * half is devoted to TIME_WAIT sockets
30 * and the rest go in the other half.
31 * Andi Kleen : Add support for syncookies and fixed
32 * some bugs: ip options weren't passed to
33 * the TCP layer, missed a check for an
35 * Andi Kleen : Implemented fast path mtu discovery.
36 * Fixed many serious bugs in the
37 * request_sock handling and moved
38 * most of it into the af independent code.
39 * Added tail drop and some other bugfixes.
40 * Added new listen semantics.
41 * Mike McLagan : Routing by source
42 * Juan Jose Ciarlante: ip_dynaddr bits
43 * Andi Kleen: various fixes.
44 * Vitaly E. Lavrov : Transparent proxy revived after year
46 * Andi Kleen : Fix new listen.
47 * Andi Kleen : Fix accept error reporting.
48 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
49 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
50 * a single port at the same time.
53 #define pr_fmt(fmt) "TCP: " fmt
55 #include <linux/bottom_half.h>
56 #include <linux/types.h>
57 #include <linux/fcntl.h>
58 #include <linux/module.h>
59 #include <linux/random.h>
60 #include <linux/cache.h>
61 #include <linux/jhash.h>
62 #include <linux/init.h>
63 #include <linux/times.h>
64 #include <linux/slab.h>
66 #include <net/net_namespace.h>
68 #include <net/inet_hashtables.h>
70 #include <net/transp_v6.h>
72 #include <net/inet_common.h>
73 #include <net/timewait_sock.h>
75 #include <net/secure_seq.h>
76 #include <net/busy_poll.h>
78 #include <linux/inet.h>
79 #include <linux/ipv6.h>
80 #include <linux/stddef.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
84 #include <crypto/hash.h>
85 #include <linux/scatterlist.h>
87 int sysctl_tcp_low_latency __read_mostly
;
89 #ifdef CONFIG_TCP_MD5SIG
90 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
91 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
);
94 struct inet_hashinfo tcp_hashinfo
;
95 EXPORT_SYMBOL(tcp_hashinfo
);
97 static u32
tcp_v4_init_seq(const struct sk_buff
*skb
)
99 return secure_tcp_seq(ip_hdr(skb
)->daddr
,
102 tcp_hdr(skb
)->source
);
105 static u32
tcp_v4_init_ts_off(const struct sk_buff
*skb
)
107 return secure_tcp_ts_off(ip_hdr(skb
)->daddr
,
111 int tcp_twsk_unique(struct sock
*sk
, struct sock
*sktw
, void *twp
)
113 const struct tcp_timewait_sock
*tcptw
= tcp_twsk(sktw
);
114 struct tcp_sock
*tp
= tcp_sk(sk
);
116 /* With PAWS, it is safe from the viewpoint
117 of data integrity. Even without PAWS it is safe provided sequence
118 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
120 Actually, the idea is close to VJ's one, only timestamp cache is
121 held not per host, but per port pair and TW bucket is used as state
124 If TW bucket has been already destroyed we fall back to VJ's scheme
125 and use initial timestamp retrieved from peer table.
127 if (tcptw
->tw_ts_recent_stamp
&&
128 (!twp
|| (sock_net(sk
)->ipv4
.sysctl_tcp_tw_reuse
&&
129 get_seconds() - tcptw
->tw_ts_recent_stamp
> 1))) {
130 tp
->write_seq
= tcptw
->tw_snd_nxt
+ 65535 + 2;
131 if (tp
->write_seq
== 0)
133 tp
->rx_opt
.ts_recent
= tcptw
->tw_ts_recent
;
134 tp
->rx_opt
.ts_recent_stamp
= tcptw
->tw_ts_recent_stamp
;
141 EXPORT_SYMBOL_GPL(tcp_twsk_unique
);
143 /* This will initiate an outgoing connection. */
144 int tcp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
)
146 struct sockaddr_in
*usin
= (struct sockaddr_in
*)uaddr
;
147 struct inet_sock
*inet
= inet_sk(sk
);
148 struct tcp_sock
*tp
= tcp_sk(sk
);
149 __be16 orig_sport
, orig_dport
;
150 __be32 daddr
, nexthop
;
154 struct ip_options_rcu
*inet_opt
;
155 struct inet_timewait_death_row
*tcp_death_row
= &sock_net(sk
)->ipv4
.tcp_death_row
;
157 if (addr_len
< sizeof(struct sockaddr_in
))
160 if (usin
->sin_family
!= AF_INET
)
161 return -EAFNOSUPPORT
;
163 nexthop
= daddr
= usin
->sin_addr
.s_addr
;
164 inet_opt
= rcu_dereference_protected(inet
->inet_opt
,
165 lockdep_sock_is_held(sk
));
166 if (inet_opt
&& inet_opt
->opt
.srr
) {
169 nexthop
= inet_opt
->opt
.faddr
;
172 orig_sport
= inet
->inet_sport
;
173 orig_dport
= usin
->sin_port
;
174 fl4
= &inet
->cork
.fl
.u
.ip4
;
175 rt
= ip_route_connect(fl4
, nexthop
, inet
->inet_saddr
,
176 RT_CONN_FLAGS(sk
), sk
->sk_bound_dev_if
,
178 orig_sport
, orig_dport
, sk
);
181 if (err
== -ENETUNREACH
)
182 IP_INC_STATS(sock_net(sk
), IPSTATS_MIB_OUTNOROUTES
);
186 if (rt
->rt_flags
& (RTCF_MULTICAST
| RTCF_BROADCAST
)) {
191 if (!inet_opt
|| !inet_opt
->opt
.srr
)
194 if (!inet
->inet_saddr
)
195 inet
->inet_saddr
= fl4
->saddr
;
196 sk_rcv_saddr_set(sk
, inet
->inet_saddr
);
198 if (tp
->rx_opt
.ts_recent_stamp
&& inet
->inet_daddr
!= daddr
) {
199 /* Reset inherited state */
200 tp
->rx_opt
.ts_recent
= 0;
201 tp
->rx_opt
.ts_recent_stamp
= 0;
202 if (likely(!tp
->repair
))
206 inet
->inet_dport
= usin
->sin_port
;
207 sk_daddr_set(sk
, daddr
);
209 inet_csk(sk
)->icsk_ext_hdr_len
= 0;
211 inet_csk(sk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
213 tp
->rx_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
215 /* Socket identity is still unknown (sport may be zero).
216 * However we set state to SYN-SENT and not releasing socket
217 * lock select source port, enter ourselves into the hash tables and
218 * complete initialization after this.
220 tcp_set_state(sk
, TCP_SYN_SENT
);
221 err
= inet_hash_connect(tcp_death_row
, sk
);
227 rt
= ip_route_newports(fl4
, rt
, orig_sport
, orig_dport
,
228 inet
->inet_sport
, inet
->inet_dport
, sk
);
234 /* OK, now commit destination to socket. */
235 sk
->sk_gso_type
= SKB_GSO_TCPV4
;
236 sk_setup_caps(sk
, &rt
->dst
);
239 if (likely(!tp
->repair
)) {
241 tp
->write_seq
= secure_tcp_seq(inet
->inet_saddr
,
245 tp
->tsoffset
= secure_tcp_ts_off(inet
->inet_saddr
,
249 inet
->inet_id
= tp
->write_seq
^ jiffies
;
251 if (tcp_fastopen_defer_connect(sk
, &err
))
256 err
= tcp_connect(sk
);
265 * This unhashes the socket and releases the local port,
268 tcp_set_state(sk
, TCP_CLOSE
);
270 sk
->sk_route_caps
= 0;
271 inet
->inet_dport
= 0;
274 EXPORT_SYMBOL(tcp_v4_connect
);
277 * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191.
278 * It can be called through tcp_release_cb() if socket was owned by user
279 * at the time tcp_v4_err() was called to handle ICMP message.
281 void tcp_v4_mtu_reduced(struct sock
*sk
)
283 struct inet_sock
*inet
= inet_sk(sk
);
284 struct dst_entry
*dst
;
287 if ((1 << sk
->sk_state
) & (TCPF_LISTEN
| TCPF_CLOSE
))
289 mtu
= tcp_sk(sk
)->mtu_info
;
290 dst
= inet_csk_update_pmtu(sk
, mtu
);
294 /* Something is about to be wrong... Remember soft error
295 * for the case, if this connection will not able to recover.
297 if (mtu
< dst_mtu(dst
) && ip_dont_fragment(sk
, dst
))
298 sk
->sk_err_soft
= EMSGSIZE
;
302 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
&&
303 ip_sk_accept_pmtu(sk
) &&
304 inet_csk(sk
)->icsk_pmtu_cookie
> mtu
) {
305 tcp_sync_mss(sk
, mtu
);
307 /* Resend the TCP packet because it's
308 * clear that the old packet has been
309 * dropped. This is the new "fast" path mtu
312 tcp_simple_retransmit(sk
);
313 } /* else let the usual retransmit timer handle it */
315 EXPORT_SYMBOL(tcp_v4_mtu_reduced
);
317 static void do_redirect(struct sk_buff
*skb
, struct sock
*sk
)
319 struct dst_entry
*dst
= __sk_dst_check(sk
, 0);
322 dst
->ops
->redirect(dst
, sk
, skb
);
326 /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */
327 void tcp_req_err(struct sock
*sk
, u32 seq
, bool abort
)
329 struct request_sock
*req
= inet_reqsk(sk
);
330 struct net
*net
= sock_net(sk
);
332 /* ICMPs are not backlogged, hence we cannot get
333 * an established socket here.
335 if (seq
!= tcp_rsk(req
)->snt_isn
) {
336 __NET_INC_STATS(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
339 * Still in SYN_RECV, just remove it silently.
340 * There is no good way to pass the error to the newly
341 * created socket, and POSIX does not want network
342 * errors returned from accept().
344 inet_csk_reqsk_queue_drop(req
->rsk_listener
, req
);
345 tcp_listendrop(req
->rsk_listener
);
349 EXPORT_SYMBOL(tcp_req_err
);
352 * This routine is called by the ICMP module when it gets some
353 * sort of error condition. If err < 0 then the socket should
354 * be closed and the error returned to the user. If err > 0
355 * it's just the icmp type << 8 | icmp code. After adjustment
356 * header points to the first 8 bytes of the tcp header. We need
357 * to find the appropriate port.
359 * The locking strategy used here is very "optimistic". When
360 * someone else accesses the socket the ICMP is just dropped
361 * and for some paths there is no check at all.
362 * A more general error queue to queue errors for later handling
363 * is probably better.
367 void tcp_v4_err(struct sk_buff
*icmp_skb
, u32 info
)
369 const struct iphdr
*iph
= (const struct iphdr
*)icmp_skb
->data
;
370 struct tcphdr
*th
= (struct tcphdr
*)(icmp_skb
->data
+ (iph
->ihl
<< 2));
371 struct inet_connection_sock
*icsk
;
373 struct inet_sock
*inet
;
374 const int type
= icmp_hdr(icmp_skb
)->type
;
375 const int code
= icmp_hdr(icmp_skb
)->code
;
378 struct request_sock
*fastopen
;
382 struct net
*net
= dev_net(icmp_skb
->dev
);
384 sk
= __inet_lookup_established(net
, &tcp_hashinfo
, iph
->daddr
,
385 th
->dest
, iph
->saddr
, ntohs(th
->source
),
388 __ICMP_INC_STATS(net
, ICMP_MIB_INERRORS
);
391 if (sk
->sk_state
== TCP_TIME_WAIT
) {
392 inet_twsk_put(inet_twsk(sk
));
395 seq
= ntohl(th
->seq
);
396 if (sk
->sk_state
== TCP_NEW_SYN_RECV
)
397 return tcp_req_err(sk
, seq
,
398 type
== ICMP_PARAMETERPROB
||
399 type
== ICMP_TIME_EXCEEDED
||
400 (type
== ICMP_DEST_UNREACH
&&
401 (code
== ICMP_NET_UNREACH
||
402 code
== ICMP_HOST_UNREACH
)));
405 /* If too many ICMPs get dropped on busy
406 * servers this needs to be solved differently.
407 * We do take care of PMTU discovery (RFC1191) special case :
408 * we can receive locally generated ICMP messages while socket is held.
410 if (sock_owned_by_user(sk
)) {
411 if (!(type
== ICMP_DEST_UNREACH
&& code
== ICMP_FRAG_NEEDED
))
412 __NET_INC_STATS(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
414 if (sk
->sk_state
== TCP_CLOSE
)
417 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
418 __NET_INC_STATS(net
, LINUX_MIB_TCPMINTTLDROP
);
424 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
425 fastopen
= tp
->fastopen_rsk
;
426 snd_una
= fastopen
? tcp_rsk(fastopen
)->snt_isn
: tp
->snd_una
;
427 if (sk
->sk_state
!= TCP_LISTEN
&&
428 !between(seq
, snd_una
, tp
->snd_nxt
)) {
429 __NET_INC_STATS(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
435 if (!sock_owned_by_user(sk
))
436 do_redirect(icmp_skb
, sk
);
438 case ICMP_SOURCE_QUENCH
:
439 /* Just silently ignore these. */
441 case ICMP_PARAMETERPROB
:
444 case ICMP_DEST_UNREACH
:
445 if (code
> NR_ICMP_UNREACH
)
448 if (code
== ICMP_FRAG_NEEDED
) { /* PMTU discovery (RFC1191) */
449 /* We are not interested in TCP_LISTEN and open_requests
450 * (SYN-ACKs send out by Linux are always <576bytes so
451 * they should go through unfragmented).
453 if (sk
->sk_state
== TCP_LISTEN
)
457 if (!sock_owned_by_user(sk
)) {
458 tcp_v4_mtu_reduced(sk
);
460 if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED
, &sk
->sk_tsq_flags
))
466 err
= icmp_err_convert
[code
].errno
;
467 /* check if icmp_skb allows revert of backoff
468 * (see draft-zimmermann-tcp-lcd) */
469 if (code
!= ICMP_NET_UNREACH
&& code
!= ICMP_HOST_UNREACH
)
471 if (seq
!= tp
->snd_una
|| !icsk
->icsk_retransmits
||
472 !icsk
->icsk_backoff
|| fastopen
)
475 if (sock_owned_by_user(sk
))
478 icsk
->icsk_backoff
--;
479 icsk
->icsk_rto
= tp
->srtt_us
? __tcp_set_rto(tp
) :
481 icsk
->icsk_rto
= inet_csk_rto_backoff(icsk
, TCP_RTO_MAX
);
483 skb
= tcp_write_queue_head(sk
);
486 remaining
= icsk
->icsk_rto
-
488 tcp_time_stamp
- tcp_skb_timestamp(skb
));
491 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
492 remaining
, TCP_RTO_MAX
);
494 /* RTO revert clocked out retransmission.
495 * Will retransmit now */
496 tcp_retransmit_timer(sk
);
500 case ICMP_TIME_EXCEEDED
:
507 switch (sk
->sk_state
) {
510 /* Only in fast or simultaneous open. If a fast open socket is
511 * is already accepted it is treated as a connected one below.
513 if (fastopen
&& !fastopen
->sk
)
516 if (!sock_owned_by_user(sk
)) {
519 sk
->sk_error_report(sk
);
523 sk
->sk_err_soft
= err
;
528 /* If we've already connected we will keep trying
529 * until we time out, or the user gives up.
531 * rfc1122 4.2.3.9 allows to consider as hard errors
532 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
533 * but it is obsoleted by pmtu discovery).
535 * Note, that in modern internet, where routing is unreliable
536 * and in each dark corner broken firewalls sit, sending random
537 * errors ordered by their masters even this two messages finally lose
538 * their original sense (even Linux sends invalid PORT_UNREACHs)
540 * Now we are in compliance with RFCs.
545 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
547 sk
->sk_error_report(sk
);
548 } else { /* Only an error on timeout */
549 sk
->sk_err_soft
= err
;
557 void __tcp_v4_send_check(struct sk_buff
*skb
, __be32 saddr
, __be32 daddr
)
559 struct tcphdr
*th
= tcp_hdr(skb
);
561 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
562 th
->check
= ~tcp_v4_check(skb
->len
, saddr
, daddr
, 0);
563 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
564 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
566 th
->check
= tcp_v4_check(skb
->len
, saddr
, daddr
,
573 /* This routine computes an IPv4 TCP checksum. */
574 void tcp_v4_send_check(struct sock
*sk
, struct sk_buff
*skb
)
576 const struct inet_sock
*inet
= inet_sk(sk
);
578 __tcp_v4_send_check(skb
, inet
->inet_saddr
, inet
->inet_daddr
);
580 EXPORT_SYMBOL(tcp_v4_send_check
);
583 * This routine will send an RST to the other tcp.
585 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
587 * Answer: if a packet caused RST, it is not for a socket
588 * existing in our system, if it is matched to a socket,
589 * it is just duplicate segment or bug in other side's TCP.
590 * So that we build reply only basing on parameters
591 * arrived with segment.
592 * Exception: precedence violation. We do not implement it in any case.
595 static void tcp_v4_send_reset(const struct sock
*sk
, struct sk_buff
*skb
)
597 const struct tcphdr
*th
= tcp_hdr(skb
);
600 #ifdef CONFIG_TCP_MD5SIG
601 __be32 opt
[(TCPOLEN_MD5SIG_ALIGNED
>> 2)];
604 struct ip_reply_arg arg
;
605 #ifdef CONFIG_TCP_MD5SIG
606 struct tcp_md5sig_key
*key
= NULL
;
607 const __u8
*hash_location
= NULL
;
608 unsigned char newhash
[16];
610 struct sock
*sk1
= NULL
;
614 /* Never send a reset in response to a reset. */
618 /* If sk not NULL, it means we did a successful lookup and incoming
619 * route had to be correct. prequeue might have dropped our dst.
621 if (!sk
&& skb_rtable(skb
)->rt_type
!= RTN_LOCAL
)
624 /* Swap the send and the receive. */
625 memset(&rep
, 0, sizeof(rep
));
626 rep
.th
.dest
= th
->source
;
627 rep
.th
.source
= th
->dest
;
628 rep
.th
.doff
= sizeof(struct tcphdr
) / 4;
632 rep
.th
.seq
= th
->ack_seq
;
635 rep
.th
.ack_seq
= htonl(ntohl(th
->seq
) + th
->syn
+ th
->fin
+
636 skb
->len
- (th
->doff
<< 2));
639 memset(&arg
, 0, sizeof(arg
));
640 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
641 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
643 net
= sk
? sock_net(sk
) : dev_net(skb_dst(skb
)->dev
);
644 #ifdef CONFIG_TCP_MD5SIG
646 hash_location
= tcp_parse_md5sig_option(th
);
647 if (sk
&& sk_fullsock(sk
)) {
648 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)
649 &ip_hdr(skb
)->saddr
, AF_INET
);
650 } else if (hash_location
) {
652 * active side is lost. Try to find listening socket through
653 * source port, and then find md5 key through listening socket.
654 * we are not loose security here:
655 * Incoming packet is checked with md5 hash with finding key,
656 * no RST generated if md5 hash doesn't match.
658 sk1
= __inet_lookup_listener(net
, &tcp_hashinfo
, NULL
, 0,
660 th
->source
, ip_hdr(skb
)->daddr
,
661 ntohs(th
->source
), inet_iif(skb
));
662 /* don't send rst if it can't find key */
666 key
= tcp_md5_do_lookup(sk1
, (union tcp_md5_addr
*)
667 &ip_hdr(skb
)->saddr
, AF_INET
);
672 genhash
= tcp_v4_md5_hash_skb(newhash
, key
, NULL
, skb
);
673 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0)
679 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) |
681 (TCPOPT_MD5SIG
<< 8) |
683 /* Update length and the length the header thinks exists */
684 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
685 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
687 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[1],
688 key
, ip_hdr(skb
)->saddr
,
689 ip_hdr(skb
)->daddr
, &rep
.th
);
692 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
693 ip_hdr(skb
)->saddr
, /* XXX */
694 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
695 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
696 arg
.flags
= (sk
&& inet_sk_transparent(sk
)) ? IP_REPLY_ARG_NOSRCCHECK
: 0;
698 /* When socket is gone, all binding information is lost.
699 * routing might fail in this case. No choice here, if we choose to force
700 * input interface, we will misroute in case of asymmetric route.
703 arg
.bound_dev_if
= sk
->sk_bound_dev_if
;
705 BUILD_BUG_ON(offsetof(struct sock
, sk_bound_dev_if
) !=
706 offsetof(struct inet_timewait_sock
, tw_bound_dev_if
));
708 arg
.tos
= ip_hdr(skb
)->tos
;
709 arg
.uid
= sock_net_uid(net
, sk
&& sk_fullsock(sk
) ? sk
: NULL
);
711 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
712 skb
, &TCP_SKB_CB(skb
)->header
.h4
.opt
,
713 ip_hdr(skb
)->saddr
, ip_hdr(skb
)->daddr
,
714 &arg
, arg
.iov
[0].iov_len
);
716 __TCP_INC_STATS(net
, TCP_MIB_OUTSEGS
);
717 __TCP_INC_STATS(net
, TCP_MIB_OUTRSTS
);
720 #ifdef CONFIG_TCP_MD5SIG
726 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
727 outside socket context is ugly, certainly. What can I do?
730 static void tcp_v4_send_ack(const struct sock
*sk
,
731 struct sk_buff
*skb
, u32 seq
, u32 ack
,
732 u32 win
, u32 tsval
, u32 tsecr
, int oif
,
733 struct tcp_md5sig_key
*key
,
734 int reply_flags
, u8 tos
)
736 const struct tcphdr
*th
= tcp_hdr(skb
);
739 __be32 opt
[(TCPOLEN_TSTAMP_ALIGNED
>> 2)
740 #ifdef CONFIG_TCP_MD5SIG
741 + (TCPOLEN_MD5SIG_ALIGNED
>> 2)
745 struct net
*net
= sock_net(sk
);
746 struct ip_reply_arg arg
;
748 memset(&rep
.th
, 0, sizeof(struct tcphdr
));
749 memset(&arg
, 0, sizeof(arg
));
751 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
752 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
754 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) | (TCPOPT_NOP
<< 16) |
755 (TCPOPT_TIMESTAMP
<< 8) |
757 rep
.opt
[1] = htonl(tsval
);
758 rep
.opt
[2] = htonl(tsecr
);
759 arg
.iov
[0].iov_len
+= TCPOLEN_TSTAMP_ALIGNED
;
762 /* Swap the send and the receive. */
763 rep
.th
.dest
= th
->source
;
764 rep
.th
.source
= th
->dest
;
765 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
766 rep
.th
.seq
= htonl(seq
);
767 rep
.th
.ack_seq
= htonl(ack
);
769 rep
.th
.window
= htons(win
);
771 #ifdef CONFIG_TCP_MD5SIG
773 int offset
= (tsecr
) ? 3 : 0;
775 rep
.opt
[offset
++] = htonl((TCPOPT_NOP
<< 24) |
777 (TCPOPT_MD5SIG
<< 8) |
779 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
780 rep
.th
.doff
= arg
.iov
[0].iov_len
/4;
782 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[offset
],
783 key
, ip_hdr(skb
)->saddr
,
784 ip_hdr(skb
)->daddr
, &rep
.th
);
787 arg
.flags
= reply_flags
;
788 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
789 ip_hdr(skb
)->saddr
, /* XXX */
790 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
791 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
793 arg
.bound_dev_if
= oif
;
795 arg
.uid
= sock_net_uid(net
, sk_fullsock(sk
) ? sk
: NULL
);
797 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
798 skb
, &TCP_SKB_CB(skb
)->header
.h4
.opt
,
799 ip_hdr(skb
)->saddr
, ip_hdr(skb
)->daddr
,
800 &arg
, arg
.iov
[0].iov_len
);
802 __TCP_INC_STATS(net
, TCP_MIB_OUTSEGS
);
806 static void tcp_v4_timewait_ack(struct sock
*sk
, struct sk_buff
*skb
)
808 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
809 struct tcp_timewait_sock
*tcptw
= tcp_twsk(sk
);
811 tcp_v4_send_ack(sk
, skb
,
812 tcptw
->tw_snd_nxt
, tcptw
->tw_rcv_nxt
,
813 tcptw
->tw_rcv_wnd
>> tw
->tw_rcv_wscale
,
814 tcp_time_stamp
+ tcptw
->tw_ts_offset
,
817 tcp_twsk_md5_key(tcptw
),
818 tw
->tw_transparent
? IP_REPLY_ARG_NOSRCCHECK
: 0,
825 static void tcp_v4_reqsk_send_ack(const struct sock
*sk
, struct sk_buff
*skb
,
826 struct request_sock
*req
)
828 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
829 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
831 u32 seq
= (sk
->sk_state
== TCP_LISTEN
) ? tcp_rsk(req
)->snt_isn
+ 1 :
835 * The window field (SEG.WND) of every outgoing segment, with the
836 * exception of <SYN> segments, MUST be right-shifted by
837 * Rcv.Wind.Shift bits:
839 tcp_v4_send_ack(sk
, skb
, seq
,
840 tcp_rsk(req
)->rcv_nxt
,
841 req
->rsk_rcv_wnd
>> inet_rsk(req
)->rcv_wscale
,
842 tcp_time_stamp
+ tcp_rsk(req
)->ts_off
,
845 tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&ip_hdr(skb
)->daddr
,
847 inet_rsk(req
)->no_srccheck
? IP_REPLY_ARG_NOSRCCHECK
: 0,
852 * Send a SYN-ACK after having received a SYN.
853 * This still operates on a request_sock only, not on a big
856 static int tcp_v4_send_synack(const struct sock
*sk
, struct dst_entry
*dst
,
858 struct request_sock
*req
,
859 struct tcp_fastopen_cookie
*foc
,
860 enum tcp_synack_type synack_type
)
862 const struct inet_request_sock
*ireq
= inet_rsk(req
);
867 /* First, grab a route. */
868 if (!dst
&& (dst
= inet_csk_route_req(sk
, &fl4
, req
)) == NULL
)
871 skb
= tcp_make_synack(sk
, dst
, req
, foc
, synack_type
);
874 __tcp_v4_send_check(skb
, ireq
->ir_loc_addr
, ireq
->ir_rmt_addr
);
876 err
= ip_build_and_send_pkt(skb
, sk
, ireq
->ir_loc_addr
,
879 err
= net_xmit_eval(err
);
886 * IPv4 request_sock destructor.
888 static void tcp_v4_reqsk_destructor(struct request_sock
*req
)
890 kfree(inet_rsk(req
)->opt
);
893 #ifdef CONFIG_TCP_MD5SIG
895 * RFC2385 MD5 checksumming requires a mapping of
896 * IP address->MD5 Key.
897 * We need to maintain these in the sk structure.
900 /* Find the Key structure for an address. */
901 struct tcp_md5sig_key
*tcp_md5_do_lookup(const struct sock
*sk
,
902 const union tcp_md5_addr
*addr
,
905 const struct tcp_sock
*tp
= tcp_sk(sk
);
906 struct tcp_md5sig_key
*key
;
907 unsigned int size
= sizeof(struct in_addr
);
908 const struct tcp_md5sig_info
*md5sig
;
910 /* caller either holds rcu_read_lock() or socket lock */
911 md5sig
= rcu_dereference_check(tp
->md5sig_info
,
912 lockdep_sock_is_held(sk
));
915 #if IS_ENABLED(CONFIG_IPV6)
916 if (family
== AF_INET6
)
917 size
= sizeof(struct in6_addr
);
919 hlist_for_each_entry_rcu(key
, &md5sig
->head
, node
) {
920 if (key
->family
!= family
)
922 if (!memcmp(&key
->addr
, addr
, size
))
927 EXPORT_SYMBOL(tcp_md5_do_lookup
);
929 struct tcp_md5sig_key
*tcp_v4_md5_lookup(const struct sock
*sk
,
930 const struct sock
*addr_sk
)
932 const union tcp_md5_addr
*addr
;
934 addr
= (const union tcp_md5_addr
*)&addr_sk
->sk_daddr
;
935 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
937 EXPORT_SYMBOL(tcp_v4_md5_lookup
);
939 /* This can be called on a newly created socket, from other files */
940 int tcp_md5_do_add(struct sock
*sk
, const union tcp_md5_addr
*addr
,
941 int family
, const u8
*newkey
, u8 newkeylen
, gfp_t gfp
)
943 /* Add Key to the list */
944 struct tcp_md5sig_key
*key
;
945 struct tcp_sock
*tp
= tcp_sk(sk
);
946 struct tcp_md5sig_info
*md5sig
;
948 key
= tcp_md5_do_lookup(sk
, addr
, family
);
950 /* Pre-existing entry - just update that one. */
951 memcpy(key
->key
, newkey
, newkeylen
);
952 key
->keylen
= newkeylen
;
956 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
957 lockdep_sock_is_held(sk
));
959 md5sig
= kmalloc(sizeof(*md5sig
), gfp
);
963 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
964 INIT_HLIST_HEAD(&md5sig
->head
);
965 rcu_assign_pointer(tp
->md5sig_info
, md5sig
);
968 key
= sock_kmalloc(sk
, sizeof(*key
), gfp
);
971 if (!tcp_alloc_md5sig_pool()) {
972 sock_kfree_s(sk
, key
, sizeof(*key
));
976 memcpy(key
->key
, newkey
, newkeylen
);
977 key
->keylen
= newkeylen
;
978 key
->family
= family
;
979 memcpy(&key
->addr
, addr
,
980 (family
== AF_INET6
) ? sizeof(struct in6_addr
) :
981 sizeof(struct in_addr
));
982 hlist_add_head_rcu(&key
->node
, &md5sig
->head
);
985 EXPORT_SYMBOL(tcp_md5_do_add
);
987 int tcp_md5_do_del(struct sock
*sk
, const union tcp_md5_addr
*addr
, int family
)
989 struct tcp_md5sig_key
*key
;
991 key
= tcp_md5_do_lookup(sk
, addr
, family
);
994 hlist_del_rcu(&key
->node
);
995 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
999 EXPORT_SYMBOL(tcp_md5_do_del
);
1001 static void tcp_clear_md5_list(struct sock
*sk
)
1003 struct tcp_sock
*tp
= tcp_sk(sk
);
1004 struct tcp_md5sig_key
*key
;
1005 struct hlist_node
*n
;
1006 struct tcp_md5sig_info
*md5sig
;
1008 md5sig
= rcu_dereference_protected(tp
->md5sig_info
, 1);
1010 hlist_for_each_entry_safe(key
, n
, &md5sig
->head
, node
) {
1011 hlist_del_rcu(&key
->node
);
1012 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
1013 kfree_rcu(key
, rcu
);
1017 static int tcp_v4_parse_md5_keys(struct sock
*sk
, char __user
*optval
,
1020 struct tcp_md5sig cmd
;
1021 struct sockaddr_in
*sin
= (struct sockaddr_in
*)&cmd
.tcpm_addr
;
1023 if (optlen
< sizeof(cmd
))
1026 if (copy_from_user(&cmd
, optval
, sizeof(cmd
)))
1029 if (sin
->sin_family
!= AF_INET
)
1032 if (!cmd
.tcpm_keylen
)
1033 return tcp_md5_do_del(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1036 if (cmd
.tcpm_keylen
> TCP_MD5SIG_MAXKEYLEN
)
1039 return tcp_md5_do_add(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1040 AF_INET
, cmd
.tcpm_key
, cmd
.tcpm_keylen
,
1044 static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool
*hp
,
1045 __be32 daddr
, __be32 saddr
,
1046 const struct tcphdr
*th
, int nbytes
)
1048 struct tcp4_pseudohdr
*bp
;
1049 struct scatterlist sg
;
1056 bp
->protocol
= IPPROTO_TCP
;
1057 bp
->len
= cpu_to_be16(nbytes
);
1059 _th
= (struct tcphdr
*)(bp
+ 1);
1060 memcpy(_th
, th
, sizeof(*th
));
1063 sg_init_one(&sg
, bp
, sizeof(*bp
) + sizeof(*th
));
1064 ahash_request_set_crypt(hp
->md5_req
, &sg
, NULL
,
1065 sizeof(*bp
) + sizeof(*th
));
1066 return crypto_ahash_update(hp
->md5_req
);
1069 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1070 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
)
1072 struct tcp_md5sig_pool
*hp
;
1073 struct ahash_request
*req
;
1075 hp
= tcp_get_md5sig_pool();
1077 goto clear_hash_noput
;
1080 if (crypto_ahash_init(req
))
1082 if (tcp_v4_md5_hash_headers(hp
, daddr
, saddr
, th
, th
->doff
<< 2))
1084 if (tcp_md5_hash_key(hp
, key
))
1086 ahash_request_set_crypt(req
, NULL
, md5_hash
, 0);
1087 if (crypto_ahash_final(req
))
1090 tcp_put_md5sig_pool();
1094 tcp_put_md5sig_pool();
1096 memset(md5_hash
, 0, 16);
1100 int tcp_v4_md5_hash_skb(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1101 const struct sock
*sk
,
1102 const struct sk_buff
*skb
)
1104 struct tcp_md5sig_pool
*hp
;
1105 struct ahash_request
*req
;
1106 const struct tcphdr
*th
= tcp_hdr(skb
);
1107 __be32 saddr
, daddr
;
1109 if (sk
) { /* valid for establish/request sockets */
1110 saddr
= sk
->sk_rcv_saddr
;
1111 daddr
= sk
->sk_daddr
;
1113 const struct iphdr
*iph
= ip_hdr(skb
);
1118 hp
= tcp_get_md5sig_pool();
1120 goto clear_hash_noput
;
1123 if (crypto_ahash_init(req
))
1126 if (tcp_v4_md5_hash_headers(hp
, daddr
, saddr
, th
, skb
->len
))
1128 if (tcp_md5_hash_skb_data(hp
, skb
, th
->doff
<< 2))
1130 if (tcp_md5_hash_key(hp
, key
))
1132 ahash_request_set_crypt(req
, NULL
, md5_hash
, 0);
1133 if (crypto_ahash_final(req
))
1136 tcp_put_md5sig_pool();
1140 tcp_put_md5sig_pool();
1142 memset(md5_hash
, 0, 16);
1145 EXPORT_SYMBOL(tcp_v4_md5_hash_skb
);
1149 /* Called with rcu_read_lock() */
1150 static bool tcp_v4_inbound_md5_hash(const struct sock
*sk
,
1151 const struct sk_buff
*skb
)
1153 #ifdef CONFIG_TCP_MD5SIG
1155 * This gets called for each TCP segment that arrives
1156 * so we want to be efficient.
1157 * We have 3 drop cases:
1158 * o No MD5 hash and one expected.
1159 * o MD5 hash and we're not expecting one.
1160 * o MD5 hash and its wrong.
1162 const __u8
*hash_location
= NULL
;
1163 struct tcp_md5sig_key
*hash_expected
;
1164 const struct iphdr
*iph
= ip_hdr(skb
);
1165 const struct tcphdr
*th
= tcp_hdr(skb
);
1167 unsigned char newhash
[16];
1169 hash_expected
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&iph
->saddr
,
1171 hash_location
= tcp_parse_md5sig_option(th
);
1173 /* We've parsed the options - do we have a hash? */
1174 if (!hash_expected
&& !hash_location
)
1177 if (hash_expected
&& !hash_location
) {
1178 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMD5NOTFOUND
);
1182 if (!hash_expected
&& hash_location
) {
1183 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMD5UNEXPECTED
);
1187 /* Okay, so this is hash_expected and hash_location -
1188 * so we need to calculate the checksum.
1190 genhash
= tcp_v4_md5_hash_skb(newhash
,
1194 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0) {
1195 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMD5FAILURE
);
1196 net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1197 &iph
->saddr
, ntohs(th
->source
),
1198 &iph
->daddr
, ntohs(th
->dest
),
1199 genhash
? " tcp_v4_calc_md5_hash failed"
1208 static void tcp_v4_init_req(struct request_sock
*req
,
1209 const struct sock
*sk_listener
,
1210 struct sk_buff
*skb
)
1212 struct inet_request_sock
*ireq
= inet_rsk(req
);
1214 sk_rcv_saddr_set(req_to_sk(req
), ip_hdr(skb
)->daddr
);
1215 sk_daddr_set(req_to_sk(req
), ip_hdr(skb
)->saddr
);
1216 ireq
->opt
= tcp_v4_save_options(skb
);
1219 static struct dst_entry
*tcp_v4_route_req(const struct sock
*sk
,
1221 const struct request_sock
*req
)
1223 return inet_csk_route_req(sk
, &fl
->u
.ip4
, req
);
1226 struct request_sock_ops tcp_request_sock_ops __read_mostly
= {
1228 .obj_size
= sizeof(struct tcp_request_sock
),
1229 .rtx_syn_ack
= tcp_rtx_synack
,
1230 .send_ack
= tcp_v4_reqsk_send_ack
,
1231 .destructor
= tcp_v4_reqsk_destructor
,
1232 .send_reset
= tcp_v4_send_reset
,
1233 .syn_ack_timeout
= tcp_syn_ack_timeout
,
1236 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops
= {
1237 .mss_clamp
= TCP_MSS_DEFAULT
,
1238 #ifdef CONFIG_TCP_MD5SIG
1239 .req_md5_lookup
= tcp_v4_md5_lookup
,
1240 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1242 .init_req
= tcp_v4_init_req
,
1243 #ifdef CONFIG_SYN_COOKIES
1244 .cookie_init_seq
= cookie_v4_init_sequence
,
1246 .route_req
= tcp_v4_route_req
,
1247 .init_seq
= tcp_v4_init_seq
,
1248 .init_ts_off
= tcp_v4_init_ts_off
,
1249 .send_synack
= tcp_v4_send_synack
,
1252 int tcp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
)
1254 /* Never answer to SYNs send to broadcast or multicast */
1255 if (skb_rtable(skb
)->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
))
1258 return tcp_conn_request(&tcp_request_sock_ops
,
1259 &tcp_request_sock_ipv4_ops
, sk
, skb
);
1265 EXPORT_SYMBOL(tcp_v4_conn_request
);
1269 * The three way handshake has completed - we got a valid synack -
1270 * now create the new socket.
1272 struct sock
*tcp_v4_syn_recv_sock(const struct sock
*sk
, struct sk_buff
*skb
,
1273 struct request_sock
*req
,
1274 struct dst_entry
*dst
,
1275 struct request_sock
*req_unhash
,
1278 struct inet_request_sock
*ireq
;
1279 struct inet_sock
*newinet
;
1280 struct tcp_sock
*newtp
;
1282 #ifdef CONFIG_TCP_MD5SIG
1283 struct tcp_md5sig_key
*key
;
1285 struct ip_options_rcu
*inet_opt
;
1287 if (sk_acceptq_is_full(sk
))
1290 newsk
= tcp_create_openreq_child(sk
, req
, skb
);
1294 newsk
->sk_gso_type
= SKB_GSO_TCPV4
;
1295 inet_sk_rx_dst_set(newsk
, skb
);
1297 newtp
= tcp_sk(newsk
);
1298 newinet
= inet_sk(newsk
);
1299 ireq
= inet_rsk(req
);
1300 sk_daddr_set(newsk
, ireq
->ir_rmt_addr
);
1301 sk_rcv_saddr_set(newsk
, ireq
->ir_loc_addr
);
1302 newsk
->sk_bound_dev_if
= ireq
->ir_iif
;
1303 newinet
->inet_saddr
= ireq
->ir_loc_addr
;
1304 inet_opt
= ireq
->opt
;
1305 rcu_assign_pointer(newinet
->inet_opt
, inet_opt
);
1307 newinet
->mc_index
= inet_iif(skb
);
1308 newinet
->mc_ttl
= ip_hdr(skb
)->ttl
;
1309 newinet
->rcv_tos
= ip_hdr(skb
)->tos
;
1310 inet_csk(newsk
)->icsk_ext_hdr_len
= 0;
1312 inet_csk(newsk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
1313 newinet
->inet_id
= newtp
->write_seq
^ jiffies
;
1316 dst
= inet_csk_route_child_sock(sk
, newsk
, req
);
1320 /* syncookie case : see end of cookie_v4_check() */
1322 sk_setup_caps(newsk
, dst
);
1324 tcp_ca_openreq_child(newsk
, dst
);
1326 tcp_sync_mss(newsk
, dst_mtu(dst
));
1327 newtp
->advmss
= tcp_mss_clamp(tcp_sk(sk
), dst_metric_advmss(dst
));
1329 tcp_initialize_rcv_mss(newsk
);
1331 #ifdef CONFIG_TCP_MD5SIG
1332 /* Copy over the MD5 key from the original socket */
1333 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1337 * We're using one, so create a matching key
1338 * on the newsk structure. If we fail to get
1339 * memory, then we end up not copying the key
1342 tcp_md5_do_add(newsk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1343 AF_INET
, key
->key
, key
->keylen
, GFP_ATOMIC
);
1344 sk_nocaps_add(newsk
, NETIF_F_GSO_MASK
);
1348 if (__inet_inherit_port(sk
, newsk
) < 0)
1350 *own_req
= inet_ehash_nolisten(newsk
, req_to_sk(req_unhash
));
1352 tcp_move_syn(newtp
, req
);
1357 NET_INC_STATS(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1364 inet_csk_prepare_forced_close(newsk
);
1368 EXPORT_SYMBOL(tcp_v4_syn_recv_sock
);
1370 static struct sock
*tcp_v4_cookie_check(struct sock
*sk
, struct sk_buff
*skb
)
1372 #ifdef CONFIG_SYN_COOKIES
1373 const struct tcphdr
*th
= tcp_hdr(skb
);
1376 sk
= cookie_v4_check(sk
, skb
);
1381 /* The socket must have it's spinlock held when we get
1382 * here, unless it is a TCP_LISTEN socket.
1384 * We have a potential double-lock case here, so even when
1385 * doing backlog processing we use the BH locking scheme.
1386 * This is because we cannot sleep with the original spinlock
1389 int tcp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
)
1393 if (sk
->sk_state
== TCP_ESTABLISHED
) { /* Fast path */
1394 struct dst_entry
*dst
= sk
->sk_rx_dst
;
1396 sock_rps_save_rxhash(sk
, skb
);
1397 sk_mark_napi_id(sk
, skb
);
1399 if (inet_sk(sk
)->rx_dst_ifindex
!= skb
->skb_iif
||
1400 !dst
->ops
->check(dst
, 0)) {
1402 sk
->sk_rx_dst
= NULL
;
1405 tcp_rcv_established(sk
, skb
, tcp_hdr(skb
), skb
->len
);
1409 if (tcp_checksum_complete(skb
))
1412 if (sk
->sk_state
== TCP_LISTEN
) {
1413 struct sock
*nsk
= tcp_v4_cookie_check(sk
, skb
);
1418 if (tcp_child_process(sk
, nsk
, skb
)) {
1425 sock_rps_save_rxhash(sk
, skb
);
1427 if (tcp_rcv_state_process(sk
, skb
)) {
1434 tcp_v4_send_reset(rsk
, skb
);
1437 /* Be careful here. If this function gets more complicated and
1438 * gcc suffers from register pressure on the x86, sk (in %ebx)
1439 * might be destroyed here. This current version compiles correctly,
1440 * but you have been warned.
1445 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CSUMERRORS
);
1446 TCP_INC_STATS(sock_net(sk
), TCP_MIB_INERRS
);
1449 EXPORT_SYMBOL(tcp_v4_do_rcv
);
1451 void tcp_v4_early_demux(struct sk_buff
*skb
)
1453 const struct iphdr
*iph
;
1454 const struct tcphdr
*th
;
1457 if (skb
->pkt_type
!= PACKET_HOST
)
1460 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + sizeof(struct tcphdr
)))
1466 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1469 sk
= __inet_lookup_established(dev_net(skb
->dev
), &tcp_hashinfo
,
1470 iph
->saddr
, th
->source
,
1471 iph
->daddr
, ntohs(th
->dest
),
1475 skb
->destructor
= sock_edemux
;
1476 if (sk_fullsock(sk
)) {
1477 struct dst_entry
*dst
= READ_ONCE(sk
->sk_rx_dst
);
1480 dst
= dst_check(dst
, 0);
1482 inet_sk(sk
)->rx_dst_ifindex
== skb
->skb_iif
)
1483 skb_dst_set_noref(skb
, dst
);
1488 /* Packet is added to VJ-style prequeue for processing in process
1489 * context, if a reader task is waiting. Apparently, this exciting
1490 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
1491 * failed somewhere. Latency? Burstiness? Well, at least now we will
1492 * see, why it failed. 8)8) --ANK
1495 bool tcp_prequeue(struct sock
*sk
, struct sk_buff
*skb
)
1497 struct tcp_sock
*tp
= tcp_sk(sk
);
1499 if (sysctl_tcp_low_latency
|| !tp
->ucopy
.task
)
1502 if (skb
->len
<= tcp_hdrlen(skb
) &&
1503 skb_queue_len(&tp
->ucopy
.prequeue
) == 0)
1506 /* Before escaping RCU protected region, we need to take care of skb
1507 * dst. Prequeue is only enabled for established sockets.
1508 * For such sockets, we might need the skb dst only to set sk->sk_rx_dst
1509 * Instead of doing full sk_rx_dst validity here, let's perform
1510 * an optimistic check.
1512 if (likely(sk
->sk_rx_dst
))
1515 skb_dst_force_safe(skb
);
1517 __skb_queue_tail(&tp
->ucopy
.prequeue
, skb
);
1518 tp
->ucopy
.memory
+= skb
->truesize
;
1519 if (skb_queue_len(&tp
->ucopy
.prequeue
) >= 32 ||
1520 tp
->ucopy
.memory
+ atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
) {
1521 struct sk_buff
*skb1
;
1523 BUG_ON(sock_owned_by_user(sk
));
1524 __NET_ADD_STATS(sock_net(sk
), LINUX_MIB_TCPPREQUEUEDROPPED
,
1525 skb_queue_len(&tp
->ucopy
.prequeue
));
1527 while ((skb1
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1528 sk_backlog_rcv(sk
, skb1
);
1530 tp
->ucopy
.memory
= 0;
1531 } else if (skb_queue_len(&tp
->ucopy
.prequeue
) == 1) {
1532 wake_up_interruptible_sync_poll(sk_sleep(sk
),
1533 POLLIN
| POLLRDNORM
| POLLRDBAND
);
1534 if (!inet_csk_ack_scheduled(sk
))
1535 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_DACK
,
1536 (3 * tcp_rto_min(sk
)) / 4,
1541 EXPORT_SYMBOL(tcp_prequeue
);
1543 bool tcp_add_backlog(struct sock
*sk
, struct sk_buff
*skb
)
1545 u32 limit
= sk
->sk_rcvbuf
+ sk
->sk_sndbuf
;
1547 /* Only socket owner can try to collapse/prune rx queues
1548 * to reduce memory overhead, so add a little headroom here.
1549 * Few sockets backlog are possibly concurrently non empty.
1553 /* In case all data was pulled from skb frags (in __pskb_pull_tail()),
1554 * we can fix skb->truesize to its real value to avoid future drops.
1555 * This is valid because skb is not yet charged to the socket.
1556 * It has been noticed pure SACK packets were sometimes dropped
1557 * (if cooked by drivers without copybreak feature).
1561 if (unlikely(sk_add_backlog(sk
, skb
, limit
))) {
1563 __NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPBACKLOGDROP
);
1568 EXPORT_SYMBOL(tcp_add_backlog
);
1570 int tcp_filter(struct sock
*sk
, struct sk_buff
*skb
)
1572 struct tcphdr
*th
= (struct tcphdr
*)skb
->data
;
1573 unsigned int eaten
= skb
->len
;
1576 err
= sk_filter_trim_cap(sk
, skb
, th
->doff
* 4);
1579 TCP_SKB_CB(skb
)->end_seq
-= eaten
;
1583 EXPORT_SYMBOL(tcp_filter
);
1589 int tcp_v4_rcv(struct sk_buff
*skb
)
1591 struct net
*net
= dev_net(skb
->dev
);
1592 const struct iphdr
*iph
;
1593 const struct tcphdr
*th
;
1598 if (skb
->pkt_type
!= PACKET_HOST
)
1601 /* Count it even if it's bad */
1602 __TCP_INC_STATS(net
, TCP_MIB_INSEGS
);
1604 if (!pskb_may_pull(skb
, sizeof(struct tcphdr
)))
1607 th
= (const struct tcphdr
*)skb
->data
;
1609 if (unlikely(th
->doff
< sizeof(struct tcphdr
) / 4))
1611 if (!pskb_may_pull(skb
, th
->doff
* 4))
1614 /* An explanation is required here, I think.
1615 * Packet length and doff are validated by header prediction,
1616 * provided case of th->doff==0 is eliminated.
1617 * So, we defer the checks. */
1619 if (skb_checksum_init(skb
, IPPROTO_TCP
, inet_compute_pseudo
))
1622 th
= (const struct tcphdr
*)skb
->data
;
1624 /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
1625 * barrier() makes sure compiler wont play fool^Waliasing games.
1627 memmove(&TCP_SKB_CB(skb
)->header
.h4
, IPCB(skb
),
1628 sizeof(struct inet_skb_parm
));
1631 TCP_SKB_CB(skb
)->seq
= ntohl(th
->seq
);
1632 TCP_SKB_CB(skb
)->end_seq
= (TCP_SKB_CB(skb
)->seq
+ th
->syn
+ th
->fin
+
1633 skb
->len
- th
->doff
* 4);
1634 TCP_SKB_CB(skb
)->ack_seq
= ntohl(th
->ack_seq
);
1635 TCP_SKB_CB(skb
)->tcp_flags
= tcp_flag_byte(th
);
1636 TCP_SKB_CB(skb
)->tcp_tw_isn
= 0;
1637 TCP_SKB_CB(skb
)->ip_dsfield
= ipv4_get_dsfield(iph
);
1638 TCP_SKB_CB(skb
)->sacked
= 0;
1641 sk
= __inet_lookup_skb(&tcp_hashinfo
, skb
, __tcp_hdrlen(th
), th
->source
,
1642 th
->dest
, &refcounted
);
1647 if (sk
->sk_state
== TCP_TIME_WAIT
)
1650 if (sk
->sk_state
== TCP_NEW_SYN_RECV
) {
1651 struct request_sock
*req
= inet_reqsk(sk
);
1654 sk
= req
->rsk_listener
;
1655 if (unlikely(tcp_v4_inbound_md5_hash(sk
, skb
))) {
1656 sk_drops_add(sk
, skb
);
1660 if (unlikely(sk
->sk_state
!= TCP_LISTEN
)) {
1661 inet_csk_reqsk_queue_drop_and_put(sk
, req
);
1664 /* We own a reference on the listener, increase it again
1665 * as we might lose it too soon.
1669 nsk
= tcp_check_req(sk
, skb
, req
, false);
1672 goto discard_and_relse
;
1676 } else if (tcp_child_process(sk
, nsk
, skb
)) {
1677 tcp_v4_send_reset(nsk
, skb
);
1678 goto discard_and_relse
;
1684 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
1685 __NET_INC_STATS(net
, LINUX_MIB_TCPMINTTLDROP
);
1686 goto discard_and_relse
;
1689 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
1690 goto discard_and_relse
;
1692 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1693 goto discard_and_relse
;
1697 if (tcp_filter(sk
, skb
))
1698 goto discard_and_relse
;
1699 th
= (const struct tcphdr
*)skb
->data
;
1704 if (sk
->sk_state
== TCP_LISTEN
) {
1705 ret
= tcp_v4_do_rcv(sk
, skb
);
1706 goto put_and_return
;
1709 sk_incoming_cpu_update(sk
);
1711 bh_lock_sock_nested(sk
);
1712 tcp_segs_in(tcp_sk(sk
), skb
);
1714 if (!sock_owned_by_user(sk
)) {
1715 if (!tcp_prequeue(sk
, skb
))
1716 ret
= tcp_v4_do_rcv(sk
, skb
);
1717 } else if (tcp_add_backlog(sk
, skb
)) {
1718 goto discard_and_relse
;
1729 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
1732 if (tcp_checksum_complete(skb
)) {
1734 __TCP_INC_STATS(net
, TCP_MIB_CSUMERRORS
);
1736 __TCP_INC_STATS(net
, TCP_MIB_INERRS
);
1738 tcp_v4_send_reset(NULL
, skb
);
1742 /* Discard frame. */
1747 sk_drops_add(sk
, skb
);
1753 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
)) {
1754 inet_twsk_put(inet_twsk(sk
));
1758 if (tcp_checksum_complete(skb
)) {
1759 inet_twsk_put(inet_twsk(sk
));
1762 switch (tcp_timewait_state_process(inet_twsk(sk
), skb
, th
)) {
1764 struct sock
*sk2
= inet_lookup_listener(dev_net(skb
->dev
),
1767 iph
->saddr
, th
->source
,
1768 iph
->daddr
, th
->dest
,
1771 inet_twsk_deschedule_put(inet_twsk(sk
));
1776 /* Fall through to ACK */
1779 tcp_v4_timewait_ack(sk
, skb
);
1782 tcp_v4_send_reset(sk
, skb
);
1783 inet_twsk_deschedule_put(inet_twsk(sk
));
1785 case TCP_TW_SUCCESS
:;
1790 static struct timewait_sock_ops tcp_timewait_sock_ops
= {
1791 .twsk_obj_size
= sizeof(struct tcp_timewait_sock
),
1792 .twsk_unique
= tcp_twsk_unique
,
1793 .twsk_destructor
= tcp_twsk_destructor
,
1796 void inet_sk_rx_dst_set(struct sock
*sk
, const struct sk_buff
*skb
)
1798 struct dst_entry
*dst
= skb_dst(skb
);
1800 if (dst
&& dst_hold_safe(dst
)) {
1801 sk
->sk_rx_dst
= dst
;
1802 inet_sk(sk
)->rx_dst_ifindex
= skb
->skb_iif
;
1805 EXPORT_SYMBOL(inet_sk_rx_dst_set
);
1807 const struct inet_connection_sock_af_ops ipv4_specific
= {
1808 .queue_xmit
= ip_queue_xmit
,
1809 .send_check
= tcp_v4_send_check
,
1810 .rebuild_header
= inet_sk_rebuild_header
,
1811 .sk_rx_dst_set
= inet_sk_rx_dst_set
,
1812 .conn_request
= tcp_v4_conn_request
,
1813 .syn_recv_sock
= tcp_v4_syn_recv_sock
,
1814 .net_header_len
= sizeof(struct iphdr
),
1815 .setsockopt
= ip_setsockopt
,
1816 .getsockopt
= ip_getsockopt
,
1817 .addr2sockaddr
= inet_csk_addr2sockaddr
,
1818 .sockaddr_len
= sizeof(struct sockaddr_in
),
1819 #ifdef CONFIG_COMPAT
1820 .compat_setsockopt
= compat_ip_setsockopt
,
1821 .compat_getsockopt
= compat_ip_getsockopt
,
1823 .mtu_reduced
= tcp_v4_mtu_reduced
,
1825 EXPORT_SYMBOL(ipv4_specific
);
1827 #ifdef CONFIG_TCP_MD5SIG
1828 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific
= {
1829 .md5_lookup
= tcp_v4_md5_lookup
,
1830 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1831 .md5_parse
= tcp_v4_parse_md5_keys
,
1835 /* NOTE: A lot of things set to zero explicitly by call to
1836 * sk_alloc() so need not be done here.
1838 static int tcp_v4_init_sock(struct sock
*sk
)
1840 struct inet_connection_sock
*icsk
= inet_csk(sk
);
1844 icsk
->icsk_af_ops
= &ipv4_specific
;
1846 #ifdef CONFIG_TCP_MD5SIG
1847 tcp_sk(sk
)->af_specific
= &tcp_sock_ipv4_specific
;
1853 void tcp_v4_destroy_sock(struct sock
*sk
)
1855 struct tcp_sock
*tp
= tcp_sk(sk
);
1857 tcp_clear_xmit_timers(sk
);
1859 tcp_cleanup_congestion_control(sk
);
1861 /* Cleanup up the write buffer. */
1862 tcp_write_queue_purge(sk
);
1864 /* Check if we want to disable active TFO */
1865 tcp_fastopen_active_disable_ofo_check(sk
);
1867 /* Cleans up our, hopefully empty, out_of_order_queue. */
1868 skb_rbtree_purge(&tp
->out_of_order_queue
);
1870 #ifdef CONFIG_TCP_MD5SIG
1871 /* Clean up the MD5 key list, if any */
1872 if (tp
->md5sig_info
) {
1873 tcp_clear_md5_list(sk
);
1874 kfree_rcu(tp
->md5sig_info
, rcu
);
1875 tp
->md5sig_info
= NULL
;
1879 /* Clean prequeue, it must be empty really */
1880 __skb_queue_purge(&tp
->ucopy
.prequeue
);
1882 /* Clean up a referenced TCP bind bucket. */
1883 if (inet_csk(sk
)->icsk_bind_hash
)
1886 BUG_ON(tp
->fastopen_rsk
);
1888 /* If socket is aborted during connect operation */
1889 tcp_free_fastopen_req(tp
);
1890 tcp_saved_syn_free(tp
);
1892 sk_sockets_allocated_dec(sk
);
1894 EXPORT_SYMBOL(tcp_v4_destroy_sock
);
1896 #ifdef CONFIG_PROC_FS
1897 /* Proc filesystem TCP sock list dumping. */
1900 * Get next listener socket follow cur. If cur is NULL, get first socket
1901 * starting from bucket given in st->bucket; when st->bucket is zero the
1902 * very first socket in the hash table is returned.
1904 static void *listening_get_next(struct seq_file
*seq
, void *cur
)
1906 struct tcp_iter_state
*st
= seq
->private;
1907 struct net
*net
= seq_file_net(seq
);
1908 struct inet_listen_hashbucket
*ilb
;
1909 struct sock
*sk
= cur
;
1913 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1914 spin_lock(&ilb
->lock
);
1915 sk
= sk_head(&ilb
->head
);
1919 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1925 sk_for_each_from(sk
) {
1926 if (!net_eq(sock_net(sk
), net
))
1928 if (sk
->sk_family
== st
->family
)
1931 spin_unlock(&ilb
->lock
);
1933 if (++st
->bucket
< INET_LHTABLE_SIZE
)
1938 static void *listening_get_idx(struct seq_file
*seq
, loff_t
*pos
)
1940 struct tcp_iter_state
*st
= seq
->private;
1945 rc
= listening_get_next(seq
, NULL
);
1947 while (rc
&& *pos
) {
1948 rc
= listening_get_next(seq
, rc
);
1954 static inline bool empty_bucket(const struct tcp_iter_state
*st
)
1956 return hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].chain
);
1960 * Get first established socket starting from bucket given in st->bucket.
1961 * If st->bucket is zero, the very first socket in the hash is returned.
1963 static void *established_get_first(struct seq_file
*seq
)
1965 struct tcp_iter_state
*st
= seq
->private;
1966 struct net
*net
= seq_file_net(seq
);
1970 for (; st
->bucket
<= tcp_hashinfo
.ehash_mask
; ++st
->bucket
) {
1972 struct hlist_nulls_node
*node
;
1973 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
);
1975 /* Lockless fast path for the common case of empty buckets */
1976 if (empty_bucket(st
))
1980 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[st
->bucket
].chain
) {
1981 if (sk
->sk_family
!= st
->family
||
1982 !net_eq(sock_net(sk
), net
)) {
1988 spin_unlock_bh(lock
);
1994 static void *established_get_next(struct seq_file
*seq
, void *cur
)
1996 struct sock
*sk
= cur
;
1997 struct hlist_nulls_node
*node
;
1998 struct tcp_iter_state
*st
= seq
->private;
1999 struct net
*net
= seq_file_net(seq
);
2004 sk
= sk_nulls_next(sk
);
2006 sk_nulls_for_each_from(sk
, node
) {
2007 if (sk
->sk_family
== st
->family
&& net_eq(sock_net(sk
), net
))
2011 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2013 return established_get_first(seq
);
2016 static void *established_get_idx(struct seq_file
*seq
, loff_t pos
)
2018 struct tcp_iter_state
*st
= seq
->private;
2022 rc
= established_get_first(seq
);
2025 rc
= established_get_next(seq
, rc
);
2031 static void *tcp_get_idx(struct seq_file
*seq
, loff_t pos
)
2034 struct tcp_iter_state
*st
= seq
->private;
2036 st
->state
= TCP_SEQ_STATE_LISTENING
;
2037 rc
= listening_get_idx(seq
, &pos
);
2040 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2041 rc
= established_get_idx(seq
, pos
);
2047 static void *tcp_seek_last_pos(struct seq_file
*seq
)
2049 struct tcp_iter_state
*st
= seq
->private;
2050 int offset
= st
->offset
;
2051 int orig_num
= st
->num
;
2054 switch (st
->state
) {
2055 case TCP_SEQ_STATE_LISTENING
:
2056 if (st
->bucket
>= INET_LHTABLE_SIZE
)
2058 st
->state
= TCP_SEQ_STATE_LISTENING
;
2059 rc
= listening_get_next(seq
, NULL
);
2060 while (offset
-- && rc
)
2061 rc
= listening_get_next(seq
, rc
);
2065 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2067 case TCP_SEQ_STATE_ESTABLISHED
:
2068 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2070 rc
= established_get_first(seq
);
2071 while (offset
-- && rc
)
2072 rc
= established_get_next(seq
, rc
);
2080 static void *tcp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2082 struct tcp_iter_state
*st
= seq
->private;
2085 if (*pos
&& *pos
== st
->last_pos
) {
2086 rc
= tcp_seek_last_pos(seq
);
2091 st
->state
= TCP_SEQ_STATE_LISTENING
;
2095 rc
= *pos
? tcp_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2098 st
->last_pos
= *pos
;
2102 static void *tcp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2104 struct tcp_iter_state
*st
= seq
->private;
2107 if (v
== SEQ_START_TOKEN
) {
2108 rc
= tcp_get_idx(seq
, 0);
2112 switch (st
->state
) {
2113 case TCP_SEQ_STATE_LISTENING
:
2114 rc
= listening_get_next(seq
, v
);
2116 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2119 rc
= established_get_first(seq
);
2122 case TCP_SEQ_STATE_ESTABLISHED
:
2123 rc
= established_get_next(seq
, v
);
2128 st
->last_pos
= *pos
;
2132 static void tcp_seq_stop(struct seq_file
*seq
, void *v
)
2134 struct tcp_iter_state
*st
= seq
->private;
2136 switch (st
->state
) {
2137 case TCP_SEQ_STATE_LISTENING
:
2138 if (v
!= SEQ_START_TOKEN
)
2139 spin_unlock(&tcp_hashinfo
.listening_hash
[st
->bucket
].lock
);
2141 case TCP_SEQ_STATE_ESTABLISHED
:
2143 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2148 int tcp_seq_open(struct inode
*inode
, struct file
*file
)
2150 struct tcp_seq_afinfo
*afinfo
= PDE_DATA(inode
);
2151 struct tcp_iter_state
*s
;
2154 err
= seq_open_net(inode
, file
, &afinfo
->seq_ops
,
2155 sizeof(struct tcp_iter_state
));
2159 s
= ((struct seq_file
*)file
->private_data
)->private;
2160 s
->family
= afinfo
->family
;
2164 EXPORT_SYMBOL(tcp_seq_open
);
2166 int tcp_proc_register(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2169 struct proc_dir_entry
*p
;
2171 afinfo
->seq_ops
.start
= tcp_seq_start
;
2172 afinfo
->seq_ops
.next
= tcp_seq_next
;
2173 afinfo
->seq_ops
.stop
= tcp_seq_stop
;
2175 p
= proc_create_data(afinfo
->name
, S_IRUGO
, net
->proc_net
,
2176 afinfo
->seq_fops
, afinfo
);
2181 EXPORT_SYMBOL(tcp_proc_register
);
2183 void tcp_proc_unregister(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2185 remove_proc_entry(afinfo
->name
, net
->proc_net
);
2187 EXPORT_SYMBOL(tcp_proc_unregister
);
2189 static void get_openreq4(const struct request_sock
*req
,
2190 struct seq_file
*f
, int i
)
2192 const struct inet_request_sock
*ireq
= inet_rsk(req
);
2193 long delta
= req
->rsk_timer
.expires
- jiffies
;
2195 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2196 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK",
2201 ntohs(ireq
->ir_rmt_port
),
2203 0, 0, /* could print option size, but that is af dependent. */
2204 1, /* timers active (only the expire timer) */
2205 jiffies_delta_to_clock_t(delta
),
2207 from_kuid_munged(seq_user_ns(f
),
2208 sock_i_uid(req
->rsk_listener
)),
2209 0, /* non standard timer */
2210 0, /* open_requests have no inode */
2215 static void get_tcp4_sock(struct sock
*sk
, struct seq_file
*f
, int i
)
2218 unsigned long timer_expires
;
2219 const struct tcp_sock
*tp
= tcp_sk(sk
);
2220 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2221 const struct inet_sock
*inet
= inet_sk(sk
);
2222 const struct fastopen_queue
*fastopenq
= &icsk
->icsk_accept_queue
.fastopenq
;
2223 __be32 dest
= inet
->inet_daddr
;
2224 __be32 src
= inet
->inet_rcv_saddr
;
2225 __u16 destp
= ntohs(inet
->inet_dport
);
2226 __u16 srcp
= ntohs(inet
->inet_sport
);
2230 if (icsk
->icsk_pending
== ICSK_TIME_RETRANS
||
2231 icsk
->icsk_pending
== ICSK_TIME_REO_TIMEOUT
||
2232 icsk
->icsk_pending
== ICSK_TIME_LOSS_PROBE
) {
2234 timer_expires
= icsk
->icsk_timeout
;
2235 } else if (icsk
->icsk_pending
== ICSK_TIME_PROBE0
) {
2237 timer_expires
= icsk
->icsk_timeout
;
2238 } else if (timer_pending(&sk
->sk_timer
)) {
2240 timer_expires
= sk
->sk_timer
.expires
;
2243 timer_expires
= jiffies
;
2246 state
= sk_state_load(sk
);
2247 if (state
== TCP_LISTEN
)
2248 rx_queue
= sk
->sk_ack_backlog
;
2250 /* Because we don't lock the socket,
2251 * we might find a transient negative value.
2253 rx_queue
= max_t(int, tp
->rcv_nxt
- tp
->copied_seq
, 0);
2255 seq_printf(f
, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2256 "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d",
2257 i
, src
, srcp
, dest
, destp
, state
,
2258 tp
->write_seq
- tp
->snd_una
,
2261 jiffies_delta_to_clock_t(timer_expires
- jiffies
),
2262 icsk
->icsk_retransmits
,
2263 from_kuid_munged(seq_user_ns(f
), sock_i_uid(sk
)),
2264 icsk
->icsk_probes_out
,
2266 atomic_read(&sk
->sk_refcnt
), sk
,
2267 jiffies_to_clock_t(icsk
->icsk_rto
),
2268 jiffies_to_clock_t(icsk
->icsk_ack
.ato
),
2269 (icsk
->icsk_ack
.quick
<< 1) | icsk
->icsk_ack
.pingpong
,
2271 state
== TCP_LISTEN
?
2272 fastopenq
->max_qlen
:
2273 (tcp_in_initial_slowstart(tp
) ? -1 : tp
->snd_ssthresh
));
2276 static void get_timewait4_sock(const struct inet_timewait_sock
*tw
,
2277 struct seq_file
*f
, int i
)
2279 long delta
= tw
->tw_timer
.expires
- jiffies
;
2283 dest
= tw
->tw_daddr
;
2284 src
= tw
->tw_rcv_saddr
;
2285 destp
= ntohs(tw
->tw_dport
);
2286 srcp
= ntohs(tw
->tw_sport
);
2288 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2289 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK",
2290 i
, src
, srcp
, dest
, destp
, tw
->tw_substate
, 0, 0,
2291 3, jiffies_delta_to_clock_t(delta
), 0, 0, 0, 0,
2292 atomic_read(&tw
->tw_refcnt
), tw
);
2297 static int tcp4_seq_show(struct seq_file
*seq
, void *v
)
2299 struct tcp_iter_state
*st
;
2300 struct sock
*sk
= v
;
2302 seq_setwidth(seq
, TMPSZ
- 1);
2303 if (v
== SEQ_START_TOKEN
) {
2304 seq_puts(seq
, " sl local_address rem_address st tx_queue "
2305 "rx_queue tr tm->when retrnsmt uid timeout "
2311 if (sk
->sk_state
== TCP_TIME_WAIT
)
2312 get_timewait4_sock(v
, seq
, st
->num
);
2313 else if (sk
->sk_state
== TCP_NEW_SYN_RECV
)
2314 get_openreq4(v
, seq
, st
->num
);
2316 get_tcp4_sock(v
, seq
, st
->num
);
2322 static const struct file_operations tcp_afinfo_seq_fops
= {
2323 .owner
= THIS_MODULE
,
2324 .open
= tcp_seq_open
,
2326 .llseek
= seq_lseek
,
2327 .release
= seq_release_net
2330 static struct tcp_seq_afinfo tcp4_seq_afinfo
= {
2333 .seq_fops
= &tcp_afinfo_seq_fops
,
2335 .show
= tcp4_seq_show
,
2339 static int __net_init
tcp4_proc_init_net(struct net
*net
)
2341 return tcp_proc_register(net
, &tcp4_seq_afinfo
);
2344 static void __net_exit
tcp4_proc_exit_net(struct net
*net
)
2346 tcp_proc_unregister(net
, &tcp4_seq_afinfo
);
2349 static struct pernet_operations tcp4_net_ops
= {
2350 .init
= tcp4_proc_init_net
,
2351 .exit
= tcp4_proc_exit_net
,
2354 int __init
tcp4_proc_init(void)
2356 return register_pernet_subsys(&tcp4_net_ops
);
2359 void tcp4_proc_exit(void)
2361 unregister_pernet_subsys(&tcp4_net_ops
);
2363 #endif /* CONFIG_PROC_FS */
2365 struct proto tcp_prot
= {
2367 .owner
= THIS_MODULE
,
2369 .connect
= tcp_v4_connect
,
2370 .disconnect
= tcp_disconnect
,
2371 .accept
= inet_csk_accept
,
2373 .init
= tcp_v4_init_sock
,
2374 .destroy
= tcp_v4_destroy_sock
,
2375 .shutdown
= tcp_shutdown
,
2376 .setsockopt
= tcp_setsockopt
,
2377 .getsockopt
= tcp_getsockopt
,
2378 .keepalive
= tcp_set_keepalive
,
2379 .recvmsg
= tcp_recvmsg
,
2380 .sendmsg
= tcp_sendmsg
,
2381 .sendpage
= tcp_sendpage
,
2382 .backlog_rcv
= tcp_v4_do_rcv
,
2383 .release_cb
= tcp_release_cb
,
2385 .unhash
= inet_unhash
,
2386 .get_port
= inet_csk_get_port
,
2387 .enter_memory_pressure
= tcp_enter_memory_pressure
,
2388 .stream_memory_free
= tcp_stream_memory_free
,
2389 .sockets_allocated
= &tcp_sockets_allocated
,
2390 .orphan_count
= &tcp_orphan_count
,
2391 .memory_allocated
= &tcp_memory_allocated
,
2392 .memory_pressure
= &tcp_memory_pressure
,
2393 .sysctl_mem
= sysctl_tcp_mem
,
2394 .sysctl_wmem
= sysctl_tcp_wmem
,
2395 .sysctl_rmem
= sysctl_tcp_rmem
,
2396 .max_header
= MAX_TCP_HEADER
,
2397 .obj_size
= sizeof(struct tcp_sock
),
2398 .slab_flags
= SLAB_TYPESAFE_BY_RCU
,
2399 .twsk_prot
= &tcp_timewait_sock_ops
,
2400 .rsk_prot
= &tcp_request_sock_ops
,
2401 .h
.hashinfo
= &tcp_hashinfo
,
2402 .no_autobind
= true,
2403 #ifdef CONFIG_COMPAT
2404 .compat_setsockopt
= compat_tcp_setsockopt
,
2405 .compat_getsockopt
= compat_tcp_getsockopt
,
2407 .diag_destroy
= tcp_abort
,
2409 EXPORT_SYMBOL(tcp_prot
);
2411 static void __net_exit
tcp_sk_exit(struct net
*net
)
2415 for_each_possible_cpu(cpu
)
2416 inet_ctl_sock_destroy(*per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
));
2417 free_percpu(net
->ipv4
.tcp_sk
);
2420 static int __net_init
tcp_sk_init(struct net
*net
)
2424 net
->ipv4
.tcp_sk
= alloc_percpu(struct sock
*);
2425 if (!net
->ipv4
.tcp_sk
)
2428 for_each_possible_cpu(cpu
) {
2431 res
= inet_ctl_sock_create(&sk
, PF_INET
, SOCK_RAW
,
2435 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
2436 *per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
) = sk
;
2439 net
->ipv4
.sysctl_tcp_ecn
= 2;
2440 net
->ipv4
.sysctl_tcp_ecn_fallback
= 1;
2442 net
->ipv4
.sysctl_tcp_base_mss
= TCP_BASE_MSS
;
2443 net
->ipv4
.sysctl_tcp_probe_threshold
= TCP_PROBE_THRESHOLD
;
2444 net
->ipv4
.sysctl_tcp_probe_interval
= TCP_PROBE_INTERVAL
;
2446 net
->ipv4
.sysctl_tcp_keepalive_time
= TCP_KEEPALIVE_TIME
;
2447 net
->ipv4
.sysctl_tcp_keepalive_probes
= TCP_KEEPALIVE_PROBES
;
2448 net
->ipv4
.sysctl_tcp_keepalive_intvl
= TCP_KEEPALIVE_INTVL
;
2450 net
->ipv4
.sysctl_tcp_syn_retries
= TCP_SYN_RETRIES
;
2451 net
->ipv4
.sysctl_tcp_synack_retries
= TCP_SYNACK_RETRIES
;
2452 net
->ipv4
.sysctl_tcp_syncookies
= 1;
2453 net
->ipv4
.sysctl_tcp_reordering
= TCP_FASTRETRANS_THRESH
;
2454 net
->ipv4
.sysctl_tcp_retries1
= TCP_RETR1
;
2455 net
->ipv4
.sysctl_tcp_retries2
= TCP_RETR2
;
2456 net
->ipv4
.sysctl_tcp_orphan_retries
= 0;
2457 net
->ipv4
.sysctl_tcp_fin_timeout
= TCP_FIN_TIMEOUT
;
2458 net
->ipv4
.sysctl_tcp_notsent_lowat
= UINT_MAX
;
2459 net
->ipv4
.sysctl_tcp_tw_reuse
= 0;
2461 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
2462 net
->ipv4
.tcp_death_row
.sysctl_max_tw_buckets
= (cnt
+ 1) / 2;
2463 net
->ipv4
.tcp_death_row
.hashinfo
= &tcp_hashinfo
;
2465 net
->ipv4
.sysctl_max_syn_backlog
= max(128, cnt
/ 256);
2474 static void __net_exit
tcp_sk_exit_batch(struct list_head
*net_exit_list
)
2476 inet_twsk_purge(&tcp_hashinfo
, AF_INET
);
2479 static struct pernet_operations __net_initdata tcp_sk_ops
= {
2480 .init
= tcp_sk_init
,
2481 .exit
= tcp_sk_exit
,
2482 .exit_batch
= tcp_sk_exit_batch
,
2485 void __init
tcp_v4_init(void)
2487 if (register_pernet_subsys(&tcp_sk_ops
))
2488 panic("Failed to create the TCP control socket.\n");