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 <linux/crypto.h>
85 #include <linux/scatterlist.h>
87 int sysctl_tcp_tw_reuse __read_mostly
;
88 int sysctl_tcp_low_latency __read_mostly
;
89 EXPORT_SYMBOL(sysctl_tcp_low_latency
);
91 #ifdef CONFIG_TCP_MD5SIG
92 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
93 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
);
96 struct inet_hashinfo tcp_hashinfo
;
97 EXPORT_SYMBOL(tcp_hashinfo
);
99 static __u32
tcp_v4_init_sequence(const struct sk_buff
*skb
)
101 return secure_tcp_sequence_number(ip_hdr(skb
)->daddr
,
104 tcp_hdr(skb
)->source
);
107 int tcp_twsk_unique(struct sock
*sk
, struct sock
*sktw
, void *twp
)
109 const struct tcp_timewait_sock
*tcptw
= tcp_twsk(sktw
);
110 struct tcp_sock
*tp
= tcp_sk(sk
);
112 /* With PAWS, it is safe from the viewpoint
113 of data integrity. Even without PAWS it is safe provided sequence
114 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
116 Actually, the idea is close to VJ's one, only timestamp cache is
117 held not per host, but per port pair and TW bucket is used as state
120 If TW bucket has been already destroyed we fall back to VJ's scheme
121 and use initial timestamp retrieved from peer table.
123 if (tcptw
->tw_ts_recent_stamp
&&
124 (!twp
|| (sysctl_tcp_tw_reuse
&&
125 get_seconds() - tcptw
->tw_ts_recent_stamp
> 1))) {
126 tp
->write_seq
= tcptw
->tw_snd_nxt
+ 65535 + 2;
127 if (tp
->write_seq
== 0)
129 tp
->rx_opt
.ts_recent
= tcptw
->tw_ts_recent
;
130 tp
->rx_opt
.ts_recent_stamp
= tcptw
->tw_ts_recent_stamp
;
137 EXPORT_SYMBOL_GPL(tcp_twsk_unique
);
139 /* This will initiate an outgoing connection. */
140 int tcp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
)
142 struct sockaddr_in
*usin
= (struct sockaddr_in
*)uaddr
;
143 struct inet_sock
*inet
= inet_sk(sk
);
144 struct tcp_sock
*tp
= tcp_sk(sk
);
145 __be16 orig_sport
, orig_dport
;
146 __be32 daddr
, nexthop
;
150 struct ip_options_rcu
*inet_opt
;
152 if (addr_len
< sizeof(struct sockaddr_in
))
155 if (usin
->sin_family
!= AF_INET
)
156 return -EAFNOSUPPORT
;
158 nexthop
= daddr
= usin
->sin_addr
.s_addr
;
159 inet_opt
= rcu_dereference_protected(inet
->inet_opt
,
160 sock_owned_by_user(sk
));
161 if (inet_opt
&& inet_opt
->opt
.srr
) {
164 nexthop
= inet_opt
->opt
.faddr
;
167 orig_sport
= inet
->inet_sport
;
168 orig_dport
= usin
->sin_port
;
169 fl4
= &inet
->cork
.fl
.u
.ip4
;
170 rt
= ip_route_connect(fl4
, nexthop
, inet
->inet_saddr
,
171 RT_CONN_FLAGS(sk
), sk
->sk_bound_dev_if
,
173 orig_sport
, orig_dport
, sk
);
176 if (err
== -ENETUNREACH
)
177 IP_INC_STATS(sock_net(sk
), IPSTATS_MIB_OUTNOROUTES
);
181 if (rt
->rt_flags
& (RTCF_MULTICAST
| RTCF_BROADCAST
)) {
186 if (!inet_opt
|| !inet_opt
->opt
.srr
)
189 if (!inet
->inet_saddr
)
190 inet
->inet_saddr
= fl4
->saddr
;
191 sk_rcv_saddr_set(sk
, inet
->inet_saddr
);
193 if (tp
->rx_opt
.ts_recent_stamp
&& inet
->inet_daddr
!= daddr
) {
194 /* Reset inherited state */
195 tp
->rx_opt
.ts_recent
= 0;
196 tp
->rx_opt
.ts_recent_stamp
= 0;
197 if (likely(!tp
->repair
))
201 if (tcp_death_row
.sysctl_tw_recycle
&&
202 !tp
->rx_opt
.ts_recent_stamp
&& fl4
->daddr
== daddr
)
203 tcp_fetch_timewait_stamp(sk
, &rt
->dst
);
205 inet
->inet_dport
= usin
->sin_port
;
206 sk_daddr_set(sk
, daddr
);
208 inet_csk(sk
)->icsk_ext_hdr_len
= 0;
210 inet_csk(sk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
212 tp
->rx_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
214 /* Socket identity is still unknown (sport may be zero).
215 * However we set state to SYN-SENT and not releasing socket
216 * lock select source port, enter ourselves into the hash tables and
217 * complete initialization after this.
219 tcp_set_state(sk
, TCP_SYN_SENT
);
220 err
= inet_hash_connect(&tcp_death_row
, sk
);
226 rt
= ip_route_newports(fl4
, rt
, orig_sport
, orig_dport
,
227 inet
->inet_sport
, inet
->inet_dport
, sk
);
233 /* OK, now commit destination to socket. */
234 sk
->sk_gso_type
= SKB_GSO_TCPV4
;
235 sk_setup_caps(sk
, &rt
->dst
);
237 if (!tp
->write_seq
&& likely(!tp
->repair
))
238 tp
->write_seq
= secure_tcp_sequence_number(inet
->inet_saddr
,
243 inet
->inet_id
= tp
->write_seq
^ jiffies
;
245 err
= tcp_connect(sk
);
255 * This unhashes the socket and releases the local port,
258 tcp_set_state(sk
, TCP_CLOSE
);
260 sk
->sk_route_caps
= 0;
261 inet
->inet_dport
= 0;
264 EXPORT_SYMBOL(tcp_v4_connect
);
267 * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191.
268 * It can be called through tcp_release_cb() if socket was owned by user
269 * at the time tcp_v4_err() was called to handle ICMP message.
271 void tcp_v4_mtu_reduced(struct sock
*sk
)
273 struct dst_entry
*dst
;
274 struct inet_sock
*inet
= inet_sk(sk
);
275 u32 mtu
= tcp_sk(sk
)->mtu_info
;
277 dst
= inet_csk_update_pmtu(sk
, mtu
);
281 /* Something is about to be wrong... Remember soft error
282 * for the case, if this connection will not able to recover.
284 if (mtu
< dst_mtu(dst
) && ip_dont_fragment(sk
, dst
))
285 sk
->sk_err_soft
= EMSGSIZE
;
289 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
&&
290 ip_sk_accept_pmtu(sk
) &&
291 inet_csk(sk
)->icsk_pmtu_cookie
> mtu
) {
292 tcp_sync_mss(sk
, mtu
);
294 /* Resend the TCP packet because it's
295 * clear that the old packet has been
296 * dropped. This is the new "fast" path mtu
299 tcp_simple_retransmit(sk
);
300 } /* else let the usual retransmit timer handle it */
302 EXPORT_SYMBOL(tcp_v4_mtu_reduced
);
304 static void do_redirect(struct sk_buff
*skb
, struct sock
*sk
)
306 struct dst_entry
*dst
= __sk_dst_check(sk
, 0);
309 dst
->ops
->redirect(dst
, sk
, skb
);
313 /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */
314 void tcp_req_err(struct sock
*sk
, u32 seq
)
316 struct request_sock
*req
= inet_reqsk(sk
);
317 struct net
*net
= sock_net(sk
);
319 /* ICMPs are not backlogged, hence we cannot get
320 * an established socket here.
324 if (seq
!= tcp_rsk(req
)->snt_isn
) {
325 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
328 * Still in SYN_RECV, just remove it silently.
329 * There is no good way to pass the error to the newly
330 * created socket, and POSIX does not want network
331 * errors returned from accept().
333 inet_csk_reqsk_queue_drop(req
->rsk_listener
, req
);
334 NET_INC_STATS_BH(net
, LINUX_MIB_LISTENDROPS
);
338 EXPORT_SYMBOL(tcp_req_err
);
341 * This routine is called by the ICMP module when it gets some
342 * sort of error condition. If err < 0 then the socket should
343 * be closed and the error returned to the user. If err > 0
344 * it's just the icmp type << 8 | icmp code. After adjustment
345 * header points to the first 8 bytes of the tcp header. We need
346 * to find the appropriate port.
348 * The locking strategy used here is very "optimistic". When
349 * someone else accesses the socket the ICMP is just dropped
350 * and for some paths there is no check at all.
351 * A more general error queue to queue errors for later handling
352 * is probably better.
356 void tcp_v4_err(struct sk_buff
*icmp_skb
, u32 info
)
358 const struct iphdr
*iph
= (const struct iphdr
*)icmp_skb
->data
;
359 struct tcphdr
*th
= (struct tcphdr
*)(icmp_skb
->data
+ (iph
->ihl
<< 2));
360 struct inet_connection_sock
*icsk
;
362 struct inet_sock
*inet
;
363 const int type
= icmp_hdr(icmp_skb
)->type
;
364 const int code
= icmp_hdr(icmp_skb
)->code
;
367 struct request_sock
*fastopen
;
371 struct net
*net
= dev_net(icmp_skb
->dev
);
373 sk
= __inet_lookup_established(net
, &tcp_hashinfo
, iph
->daddr
,
374 th
->dest
, iph
->saddr
, ntohs(th
->source
),
377 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
380 if (sk
->sk_state
== TCP_TIME_WAIT
) {
381 inet_twsk_put(inet_twsk(sk
));
384 seq
= ntohl(th
->seq
);
385 if (sk
->sk_state
== TCP_NEW_SYN_RECV
)
386 return tcp_req_err(sk
, seq
);
389 /* If too many ICMPs get dropped on busy
390 * servers this needs to be solved differently.
391 * We do take care of PMTU discovery (RFC1191) special case :
392 * we can receive locally generated ICMP messages while socket is held.
394 if (sock_owned_by_user(sk
)) {
395 if (!(type
== ICMP_DEST_UNREACH
&& code
== ICMP_FRAG_NEEDED
))
396 NET_INC_STATS_BH(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
398 if (sk
->sk_state
== TCP_CLOSE
)
401 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
402 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
408 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
409 fastopen
= tp
->fastopen_rsk
;
410 snd_una
= fastopen
? tcp_rsk(fastopen
)->snt_isn
: tp
->snd_una
;
411 if (sk
->sk_state
!= TCP_LISTEN
&&
412 !between(seq
, snd_una
, tp
->snd_nxt
)) {
413 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
419 do_redirect(icmp_skb
, sk
);
421 case ICMP_SOURCE_QUENCH
:
422 /* Just silently ignore these. */
424 case ICMP_PARAMETERPROB
:
427 case ICMP_DEST_UNREACH
:
428 if (code
> NR_ICMP_UNREACH
)
431 if (code
== ICMP_FRAG_NEEDED
) { /* PMTU discovery (RFC1191) */
432 /* We are not interested in TCP_LISTEN and open_requests
433 * (SYN-ACKs send out by Linux are always <576bytes so
434 * they should go through unfragmented).
436 if (sk
->sk_state
== TCP_LISTEN
)
440 if (!sock_owned_by_user(sk
)) {
441 tcp_v4_mtu_reduced(sk
);
443 if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED
, &tp
->tsq_flags
))
449 err
= icmp_err_convert
[code
].errno
;
450 /* check if icmp_skb allows revert of backoff
451 * (see draft-zimmermann-tcp-lcd) */
452 if (code
!= ICMP_NET_UNREACH
&& code
!= ICMP_HOST_UNREACH
)
454 if (seq
!= tp
->snd_una
|| !icsk
->icsk_retransmits
||
455 !icsk
->icsk_backoff
|| fastopen
)
458 if (sock_owned_by_user(sk
))
461 icsk
->icsk_backoff
--;
462 icsk
->icsk_rto
= tp
->srtt_us
? __tcp_set_rto(tp
) :
464 icsk
->icsk_rto
= inet_csk_rto_backoff(icsk
, TCP_RTO_MAX
);
466 skb
= tcp_write_queue_head(sk
);
469 remaining
= icsk
->icsk_rto
-
471 tcp_time_stamp
- tcp_skb_timestamp(skb
));
474 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
475 remaining
, TCP_RTO_MAX
);
477 /* RTO revert clocked out retransmission.
478 * Will retransmit now */
479 tcp_retransmit_timer(sk
);
483 case ICMP_TIME_EXCEEDED
:
490 switch (sk
->sk_state
) {
493 /* Only in fast or simultaneous open. If a fast open socket is
494 * is already accepted it is treated as a connected one below.
496 if (fastopen
&& !fastopen
->sk
)
499 if (!sock_owned_by_user(sk
)) {
502 sk
->sk_error_report(sk
);
506 sk
->sk_err_soft
= err
;
511 /* If we've already connected we will keep trying
512 * until we time out, or the user gives up.
514 * rfc1122 4.2.3.9 allows to consider as hard errors
515 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
516 * but it is obsoleted by pmtu discovery).
518 * Note, that in modern internet, where routing is unreliable
519 * and in each dark corner broken firewalls sit, sending random
520 * errors ordered by their masters even this two messages finally lose
521 * their original sense (even Linux sends invalid PORT_UNREACHs)
523 * Now we are in compliance with RFCs.
528 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
530 sk
->sk_error_report(sk
);
531 } else { /* Only an error on timeout */
532 sk
->sk_err_soft
= err
;
540 void __tcp_v4_send_check(struct sk_buff
*skb
, __be32 saddr
, __be32 daddr
)
542 struct tcphdr
*th
= tcp_hdr(skb
);
544 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
545 th
->check
= ~tcp_v4_check(skb
->len
, saddr
, daddr
, 0);
546 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
547 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
549 th
->check
= tcp_v4_check(skb
->len
, saddr
, daddr
,
556 /* This routine computes an IPv4 TCP checksum. */
557 void tcp_v4_send_check(struct sock
*sk
, struct sk_buff
*skb
)
559 const struct inet_sock
*inet
= inet_sk(sk
);
561 __tcp_v4_send_check(skb
, inet
->inet_saddr
, inet
->inet_daddr
);
563 EXPORT_SYMBOL(tcp_v4_send_check
);
566 * This routine will send an RST to the other tcp.
568 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
570 * Answer: if a packet caused RST, it is not for a socket
571 * existing in our system, if it is matched to a socket,
572 * it is just duplicate segment or bug in other side's TCP.
573 * So that we build reply only basing on parameters
574 * arrived with segment.
575 * Exception: precedence violation. We do not implement it in any case.
578 static void tcp_v4_send_reset(const struct sock
*sk
, struct sk_buff
*skb
)
580 const struct tcphdr
*th
= tcp_hdr(skb
);
583 #ifdef CONFIG_TCP_MD5SIG
584 __be32 opt
[(TCPOLEN_MD5SIG_ALIGNED
>> 2)];
587 struct ip_reply_arg arg
;
588 #ifdef CONFIG_TCP_MD5SIG
589 struct tcp_md5sig_key
*key
= NULL
;
590 const __u8
*hash_location
= NULL
;
591 unsigned char newhash
[16];
593 struct sock
*sk1
= NULL
;
597 /* Never send a reset in response to a reset. */
601 /* If sk not NULL, it means we did a successful lookup and incoming
602 * route had to be correct. prequeue might have dropped our dst.
604 if (!sk
&& skb_rtable(skb
)->rt_type
!= RTN_LOCAL
)
607 /* Swap the send and the receive. */
608 memset(&rep
, 0, sizeof(rep
));
609 rep
.th
.dest
= th
->source
;
610 rep
.th
.source
= th
->dest
;
611 rep
.th
.doff
= sizeof(struct tcphdr
) / 4;
615 rep
.th
.seq
= th
->ack_seq
;
618 rep
.th
.ack_seq
= htonl(ntohl(th
->seq
) + th
->syn
+ th
->fin
+
619 skb
->len
- (th
->doff
<< 2));
622 memset(&arg
, 0, sizeof(arg
));
623 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
624 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
626 net
= sk
? sock_net(sk
) : dev_net(skb_dst(skb
)->dev
);
627 #ifdef CONFIG_TCP_MD5SIG
628 hash_location
= tcp_parse_md5sig_option(th
);
629 if (sk
&& sk_fullsock(sk
)) {
630 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)
631 &ip_hdr(skb
)->saddr
, AF_INET
);
632 } else if (hash_location
) {
634 * active side is lost. Try to find listening socket through
635 * source port, and then find md5 key through listening socket.
636 * we are not loose security here:
637 * Incoming packet is checked with md5 hash with finding key,
638 * no RST generated if md5 hash doesn't match.
640 sk1
= __inet_lookup_listener(net
,
641 &tcp_hashinfo
, ip_hdr(skb
)->saddr
,
642 th
->source
, ip_hdr(skb
)->daddr
,
643 ntohs(th
->source
), inet_iif(skb
));
644 /* don't send rst if it can't find key */
648 key
= tcp_md5_do_lookup(sk1
, (union tcp_md5_addr
*)
649 &ip_hdr(skb
)->saddr
, AF_INET
);
653 genhash
= tcp_v4_md5_hash_skb(newhash
, key
, NULL
, skb
);
654 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0)
659 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) |
661 (TCPOPT_MD5SIG
<< 8) |
663 /* Update length and the length the header thinks exists */
664 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
665 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
667 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[1],
668 key
, ip_hdr(skb
)->saddr
,
669 ip_hdr(skb
)->daddr
, &rep
.th
);
672 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
673 ip_hdr(skb
)->saddr
, /* XXX */
674 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
675 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
676 arg
.flags
= (sk
&& inet_sk_transparent(sk
)) ? IP_REPLY_ARG_NOSRCCHECK
: 0;
678 /* When socket is gone, all binding information is lost.
679 * routing might fail in this case. No choice here, if we choose to force
680 * input interface, we will misroute in case of asymmetric route.
683 arg
.bound_dev_if
= sk
->sk_bound_dev_if
;
685 BUILD_BUG_ON(offsetof(struct sock
, sk_bound_dev_if
) !=
686 offsetof(struct inet_timewait_sock
, tw_bound_dev_if
));
688 arg
.tos
= ip_hdr(skb
)->tos
;
689 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
690 skb
, &TCP_SKB_CB(skb
)->header
.h4
.opt
,
691 ip_hdr(skb
)->saddr
, ip_hdr(skb
)->daddr
,
692 &arg
, arg
.iov
[0].iov_len
);
694 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
695 TCP_INC_STATS_BH(net
, TCP_MIB_OUTRSTS
);
697 #ifdef CONFIG_TCP_MD5SIG
706 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
707 outside socket context is ugly, certainly. What can I do?
710 static void tcp_v4_send_ack(struct net
*net
,
711 struct sk_buff
*skb
, u32 seq
, u32 ack
,
712 u32 win
, u32 tsval
, u32 tsecr
, int oif
,
713 struct tcp_md5sig_key
*key
,
714 int reply_flags
, u8 tos
)
716 const struct tcphdr
*th
= tcp_hdr(skb
);
719 __be32 opt
[(TCPOLEN_TSTAMP_ALIGNED
>> 2)
720 #ifdef CONFIG_TCP_MD5SIG
721 + (TCPOLEN_MD5SIG_ALIGNED
>> 2)
725 struct ip_reply_arg arg
;
727 memset(&rep
.th
, 0, sizeof(struct tcphdr
));
728 memset(&arg
, 0, sizeof(arg
));
730 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
731 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
733 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) | (TCPOPT_NOP
<< 16) |
734 (TCPOPT_TIMESTAMP
<< 8) |
736 rep
.opt
[1] = htonl(tsval
);
737 rep
.opt
[2] = htonl(tsecr
);
738 arg
.iov
[0].iov_len
+= TCPOLEN_TSTAMP_ALIGNED
;
741 /* Swap the send and the receive. */
742 rep
.th
.dest
= th
->source
;
743 rep
.th
.source
= th
->dest
;
744 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
745 rep
.th
.seq
= htonl(seq
);
746 rep
.th
.ack_seq
= htonl(ack
);
748 rep
.th
.window
= htons(win
);
750 #ifdef CONFIG_TCP_MD5SIG
752 int offset
= (tsecr
) ? 3 : 0;
754 rep
.opt
[offset
++] = htonl((TCPOPT_NOP
<< 24) |
756 (TCPOPT_MD5SIG
<< 8) |
758 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
759 rep
.th
.doff
= arg
.iov
[0].iov_len
/4;
761 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[offset
],
762 key
, ip_hdr(skb
)->saddr
,
763 ip_hdr(skb
)->daddr
, &rep
.th
);
766 arg
.flags
= reply_flags
;
767 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
768 ip_hdr(skb
)->saddr
, /* XXX */
769 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
770 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
772 arg
.bound_dev_if
= oif
;
774 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
775 skb
, &TCP_SKB_CB(skb
)->header
.h4
.opt
,
776 ip_hdr(skb
)->saddr
, ip_hdr(skb
)->daddr
,
777 &arg
, arg
.iov
[0].iov_len
);
779 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
782 static void tcp_v4_timewait_ack(struct sock
*sk
, struct sk_buff
*skb
)
784 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
785 struct tcp_timewait_sock
*tcptw
= tcp_twsk(sk
);
787 tcp_v4_send_ack(sock_net(sk
), skb
,
788 tcptw
->tw_snd_nxt
, tcptw
->tw_rcv_nxt
,
789 tcptw
->tw_rcv_wnd
>> tw
->tw_rcv_wscale
,
790 tcp_time_stamp
+ tcptw
->tw_ts_offset
,
793 tcp_twsk_md5_key(tcptw
),
794 tw
->tw_transparent
? IP_REPLY_ARG_NOSRCCHECK
: 0,
801 static void tcp_v4_reqsk_send_ack(const struct sock
*sk
, struct sk_buff
*skb
,
802 struct request_sock
*req
)
804 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
805 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
807 u32 seq
= (sk
->sk_state
== TCP_LISTEN
) ? tcp_rsk(req
)->snt_isn
+ 1 :
810 tcp_v4_send_ack(sock_net(sk
), skb
, seq
,
811 tcp_rsk(req
)->rcv_nxt
, req
->rsk_rcv_wnd
,
815 tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&ip_hdr(skb
)->daddr
,
817 inet_rsk(req
)->no_srccheck
? IP_REPLY_ARG_NOSRCCHECK
: 0,
822 * Send a SYN-ACK after having received a SYN.
823 * This still operates on a request_sock only, not on a big
826 static int tcp_v4_send_synack(const struct sock
*sk
, struct dst_entry
*dst
,
828 struct request_sock
*req
,
829 struct tcp_fastopen_cookie
*foc
,
832 const struct inet_request_sock
*ireq
= inet_rsk(req
);
837 /* First, grab a route. */
838 if (!dst
&& (dst
= inet_csk_route_req(sk
, &fl4
, req
)) == NULL
)
841 skb
= tcp_make_synack(sk
, dst
, req
, foc
, attach_req
);
844 __tcp_v4_send_check(skb
, ireq
->ir_loc_addr
, ireq
->ir_rmt_addr
);
846 err
= ip_build_and_send_pkt(skb
, sk
, ireq
->ir_loc_addr
,
849 err
= net_xmit_eval(err
);
856 * IPv4 request_sock destructor.
858 static void tcp_v4_reqsk_destructor(struct request_sock
*req
)
860 kfree(inet_rsk(req
)->opt
);
863 #ifdef CONFIG_TCP_MD5SIG
865 * RFC2385 MD5 checksumming requires a mapping of
866 * IP address->MD5 Key.
867 * We need to maintain these in the sk structure.
870 /* Find the Key structure for an address. */
871 struct tcp_md5sig_key
*tcp_md5_do_lookup(const struct sock
*sk
,
872 const union tcp_md5_addr
*addr
,
875 const struct tcp_sock
*tp
= tcp_sk(sk
);
876 struct tcp_md5sig_key
*key
;
877 unsigned int size
= sizeof(struct in_addr
);
878 const struct tcp_md5sig_info
*md5sig
;
880 /* caller either holds rcu_read_lock() or socket lock */
881 md5sig
= rcu_dereference_check(tp
->md5sig_info
,
882 sock_owned_by_user(sk
) ||
883 lockdep_is_held((spinlock_t
*)&sk
->sk_lock
.slock
));
886 #if IS_ENABLED(CONFIG_IPV6)
887 if (family
== AF_INET6
)
888 size
= sizeof(struct in6_addr
);
890 hlist_for_each_entry_rcu(key
, &md5sig
->head
, node
) {
891 if (key
->family
!= family
)
893 if (!memcmp(&key
->addr
, addr
, size
))
898 EXPORT_SYMBOL(tcp_md5_do_lookup
);
900 struct tcp_md5sig_key
*tcp_v4_md5_lookup(const struct sock
*sk
,
901 const struct sock
*addr_sk
)
903 const union tcp_md5_addr
*addr
;
905 addr
= (const union tcp_md5_addr
*)&addr_sk
->sk_daddr
;
906 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
908 EXPORT_SYMBOL(tcp_v4_md5_lookup
);
910 /* This can be called on a newly created socket, from other files */
911 int tcp_md5_do_add(struct sock
*sk
, const union tcp_md5_addr
*addr
,
912 int family
, const u8
*newkey
, u8 newkeylen
, gfp_t gfp
)
914 /* Add Key to the list */
915 struct tcp_md5sig_key
*key
;
916 struct tcp_sock
*tp
= tcp_sk(sk
);
917 struct tcp_md5sig_info
*md5sig
;
919 key
= tcp_md5_do_lookup(sk
, addr
, family
);
921 /* Pre-existing entry - just update that one. */
922 memcpy(key
->key
, newkey
, newkeylen
);
923 key
->keylen
= newkeylen
;
927 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
928 sock_owned_by_user(sk
) ||
929 lockdep_is_held(&sk
->sk_lock
.slock
));
931 md5sig
= kmalloc(sizeof(*md5sig
), gfp
);
935 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
936 INIT_HLIST_HEAD(&md5sig
->head
);
937 rcu_assign_pointer(tp
->md5sig_info
, md5sig
);
940 key
= sock_kmalloc(sk
, sizeof(*key
), gfp
);
943 if (!tcp_alloc_md5sig_pool()) {
944 sock_kfree_s(sk
, key
, sizeof(*key
));
948 memcpy(key
->key
, newkey
, newkeylen
);
949 key
->keylen
= newkeylen
;
950 key
->family
= family
;
951 memcpy(&key
->addr
, addr
,
952 (family
== AF_INET6
) ? sizeof(struct in6_addr
) :
953 sizeof(struct in_addr
));
954 hlist_add_head_rcu(&key
->node
, &md5sig
->head
);
957 EXPORT_SYMBOL(tcp_md5_do_add
);
959 int tcp_md5_do_del(struct sock
*sk
, const union tcp_md5_addr
*addr
, int family
)
961 struct tcp_md5sig_key
*key
;
963 key
= tcp_md5_do_lookup(sk
, addr
, family
);
966 hlist_del_rcu(&key
->node
);
967 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
971 EXPORT_SYMBOL(tcp_md5_do_del
);
973 static void tcp_clear_md5_list(struct sock
*sk
)
975 struct tcp_sock
*tp
= tcp_sk(sk
);
976 struct tcp_md5sig_key
*key
;
977 struct hlist_node
*n
;
978 struct tcp_md5sig_info
*md5sig
;
980 md5sig
= rcu_dereference_protected(tp
->md5sig_info
, 1);
982 hlist_for_each_entry_safe(key
, n
, &md5sig
->head
, node
) {
983 hlist_del_rcu(&key
->node
);
984 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
989 static int tcp_v4_parse_md5_keys(struct sock
*sk
, char __user
*optval
,
992 struct tcp_md5sig cmd
;
993 struct sockaddr_in
*sin
= (struct sockaddr_in
*)&cmd
.tcpm_addr
;
995 if (optlen
< sizeof(cmd
))
998 if (copy_from_user(&cmd
, optval
, sizeof(cmd
)))
1001 if (sin
->sin_family
!= AF_INET
)
1004 if (!cmd
.tcpm_keylen
)
1005 return tcp_md5_do_del(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1008 if (cmd
.tcpm_keylen
> TCP_MD5SIG_MAXKEYLEN
)
1011 return tcp_md5_do_add(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1012 AF_INET
, cmd
.tcpm_key
, cmd
.tcpm_keylen
,
1016 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool
*hp
,
1017 __be32 daddr
, __be32 saddr
, int nbytes
)
1019 struct tcp4_pseudohdr
*bp
;
1020 struct scatterlist sg
;
1022 bp
= &hp
->md5_blk
.ip4
;
1025 * 1. the TCP pseudo-header (in the order: source IP address,
1026 * destination IP address, zero-padded protocol number, and
1032 bp
->protocol
= IPPROTO_TCP
;
1033 bp
->len
= cpu_to_be16(nbytes
);
1035 sg_init_one(&sg
, bp
, sizeof(*bp
));
1036 return crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(*bp
));
1039 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1040 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
)
1042 struct tcp_md5sig_pool
*hp
;
1043 struct hash_desc
*desc
;
1045 hp
= tcp_get_md5sig_pool();
1047 goto clear_hash_noput
;
1048 desc
= &hp
->md5_desc
;
1050 if (crypto_hash_init(desc
))
1052 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, th
->doff
<< 2))
1054 if (tcp_md5_hash_header(hp
, th
))
1056 if (tcp_md5_hash_key(hp
, key
))
1058 if (crypto_hash_final(desc
, md5_hash
))
1061 tcp_put_md5sig_pool();
1065 tcp_put_md5sig_pool();
1067 memset(md5_hash
, 0, 16);
1071 int tcp_v4_md5_hash_skb(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1072 const struct sock
*sk
,
1073 const struct sk_buff
*skb
)
1075 struct tcp_md5sig_pool
*hp
;
1076 struct hash_desc
*desc
;
1077 const struct tcphdr
*th
= tcp_hdr(skb
);
1078 __be32 saddr
, daddr
;
1080 if (sk
) { /* valid for establish/request sockets */
1081 saddr
= sk
->sk_rcv_saddr
;
1082 daddr
= sk
->sk_daddr
;
1084 const struct iphdr
*iph
= ip_hdr(skb
);
1089 hp
= tcp_get_md5sig_pool();
1091 goto clear_hash_noput
;
1092 desc
= &hp
->md5_desc
;
1094 if (crypto_hash_init(desc
))
1097 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, skb
->len
))
1099 if (tcp_md5_hash_header(hp
, th
))
1101 if (tcp_md5_hash_skb_data(hp
, skb
, th
->doff
<< 2))
1103 if (tcp_md5_hash_key(hp
, key
))
1105 if (crypto_hash_final(desc
, md5_hash
))
1108 tcp_put_md5sig_pool();
1112 tcp_put_md5sig_pool();
1114 memset(md5_hash
, 0, 16);
1117 EXPORT_SYMBOL(tcp_v4_md5_hash_skb
);
1121 /* Called with rcu_read_lock() */
1122 static bool tcp_v4_inbound_md5_hash(const struct sock
*sk
,
1123 const struct sk_buff
*skb
)
1125 #ifdef CONFIG_TCP_MD5SIG
1127 * This gets called for each TCP segment that arrives
1128 * so we want to be efficient.
1129 * We have 3 drop cases:
1130 * o No MD5 hash and one expected.
1131 * o MD5 hash and we're not expecting one.
1132 * o MD5 hash and its wrong.
1134 const __u8
*hash_location
= NULL
;
1135 struct tcp_md5sig_key
*hash_expected
;
1136 const struct iphdr
*iph
= ip_hdr(skb
);
1137 const struct tcphdr
*th
= tcp_hdr(skb
);
1139 unsigned char newhash
[16];
1141 hash_expected
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&iph
->saddr
,
1143 hash_location
= tcp_parse_md5sig_option(th
);
1145 /* We've parsed the options - do we have a hash? */
1146 if (!hash_expected
&& !hash_location
)
1149 if (hash_expected
&& !hash_location
) {
1150 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5NOTFOUND
);
1154 if (!hash_expected
&& hash_location
) {
1155 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5UNEXPECTED
);
1159 /* Okay, so this is hash_expected and hash_location -
1160 * so we need to calculate the checksum.
1162 genhash
= tcp_v4_md5_hash_skb(newhash
,
1166 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0) {
1167 net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1168 &iph
->saddr
, ntohs(th
->source
),
1169 &iph
->daddr
, ntohs(th
->dest
),
1170 genhash
? " tcp_v4_calc_md5_hash failed"
1179 static void tcp_v4_init_req(struct request_sock
*req
,
1180 const struct sock
*sk_listener
,
1181 struct sk_buff
*skb
)
1183 struct inet_request_sock
*ireq
= inet_rsk(req
);
1185 sk_rcv_saddr_set(req_to_sk(req
), ip_hdr(skb
)->daddr
);
1186 sk_daddr_set(req_to_sk(req
), ip_hdr(skb
)->saddr
);
1187 ireq
->no_srccheck
= inet_sk(sk_listener
)->transparent
;
1188 ireq
->opt
= tcp_v4_save_options(skb
);
1191 static struct dst_entry
*tcp_v4_route_req(const struct sock
*sk
,
1193 const struct request_sock
*req
,
1196 struct dst_entry
*dst
= inet_csk_route_req(sk
, &fl
->u
.ip4
, req
);
1199 if (fl
->u
.ip4
.daddr
== inet_rsk(req
)->ir_rmt_addr
)
1208 struct request_sock_ops tcp_request_sock_ops __read_mostly
= {
1210 .obj_size
= sizeof(struct tcp_request_sock
),
1211 .rtx_syn_ack
= tcp_rtx_synack
,
1212 .send_ack
= tcp_v4_reqsk_send_ack
,
1213 .destructor
= tcp_v4_reqsk_destructor
,
1214 .send_reset
= tcp_v4_send_reset
,
1215 .syn_ack_timeout
= tcp_syn_ack_timeout
,
1218 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops
= {
1219 .mss_clamp
= TCP_MSS_DEFAULT
,
1220 #ifdef CONFIG_TCP_MD5SIG
1221 .req_md5_lookup
= tcp_v4_md5_lookup
,
1222 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1224 .init_req
= tcp_v4_init_req
,
1225 #ifdef CONFIG_SYN_COOKIES
1226 .cookie_init_seq
= cookie_v4_init_sequence
,
1228 .route_req
= tcp_v4_route_req
,
1229 .init_seq
= tcp_v4_init_sequence
,
1230 .send_synack
= tcp_v4_send_synack
,
1233 int tcp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
)
1235 /* Never answer to SYNs send to broadcast or multicast */
1236 if (skb_rtable(skb
)->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
))
1239 return tcp_conn_request(&tcp_request_sock_ops
,
1240 &tcp_request_sock_ipv4_ops
, sk
, skb
);
1243 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1246 EXPORT_SYMBOL(tcp_v4_conn_request
);
1250 * The three way handshake has completed - we got a valid synack -
1251 * now create the new socket.
1253 struct sock
*tcp_v4_syn_recv_sock(const struct sock
*sk
, struct sk_buff
*skb
,
1254 struct request_sock
*req
,
1255 struct dst_entry
*dst
,
1256 struct request_sock
*req_unhash
,
1259 struct inet_request_sock
*ireq
;
1260 struct inet_sock
*newinet
;
1261 struct tcp_sock
*newtp
;
1263 #ifdef CONFIG_TCP_MD5SIG
1264 struct tcp_md5sig_key
*key
;
1266 struct ip_options_rcu
*inet_opt
;
1268 if (sk_acceptq_is_full(sk
))
1271 newsk
= tcp_create_openreq_child(sk
, req
, skb
);
1275 newsk
->sk_gso_type
= SKB_GSO_TCPV4
;
1276 inet_sk_rx_dst_set(newsk
, skb
);
1278 newtp
= tcp_sk(newsk
);
1279 newinet
= inet_sk(newsk
);
1280 ireq
= inet_rsk(req
);
1281 sk_daddr_set(newsk
, ireq
->ir_rmt_addr
);
1282 sk_rcv_saddr_set(newsk
, ireq
->ir_loc_addr
);
1283 newsk
->sk_bound_dev_if
= ireq
->ir_iif
;
1284 newinet
->inet_saddr
= ireq
->ir_loc_addr
;
1285 inet_opt
= ireq
->opt
;
1286 rcu_assign_pointer(newinet
->inet_opt
, inet_opt
);
1288 newinet
->mc_index
= inet_iif(skb
);
1289 newinet
->mc_ttl
= ip_hdr(skb
)->ttl
;
1290 newinet
->rcv_tos
= ip_hdr(skb
)->tos
;
1291 inet_csk(newsk
)->icsk_ext_hdr_len
= 0;
1293 inet_csk(newsk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
1294 newinet
->inet_id
= newtp
->write_seq
^ jiffies
;
1297 dst
= inet_csk_route_child_sock(sk
, newsk
, req
);
1301 /* syncookie case : see end of cookie_v4_check() */
1303 sk_setup_caps(newsk
, dst
);
1305 tcp_ca_openreq_child(newsk
, dst
);
1307 tcp_sync_mss(newsk
, dst_mtu(dst
));
1308 newtp
->advmss
= dst_metric_advmss(dst
);
1309 if (tcp_sk(sk
)->rx_opt
.user_mss
&&
1310 tcp_sk(sk
)->rx_opt
.user_mss
< newtp
->advmss
)
1311 newtp
->advmss
= tcp_sk(sk
)->rx_opt
.user_mss
;
1313 tcp_initialize_rcv_mss(newsk
);
1315 #ifdef CONFIG_TCP_MD5SIG
1316 /* Copy over the MD5 key from the original socket */
1317 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1321 * We're using one, so create a matching key
1322 * on the newsk structure. If we fail to get
1323 * memory, then we end up not copying the key
1326 tcp_md5_do_add(newsk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1327 AF_INET
, key
->key
, key
->keylen
, GFP_ATOMIC
);
1328 sk_nocaps_add(newsk
, NETIF_F_GSO_MASK
);
1332 if (__inet_inherit_port(sk
, newsk
) < 0)
1334 *own_req
= inet_ehash_nolisten(newsk
, req_to_sk(req_unhash
));
1336 tcp_move_syn(newtp
, req
);
1341 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1345 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1348 inet_csk_prepare_forced_close(newsk
);
1352 EXPORT_SYMBOL(tcp_v4_syn_recv_sock
);
1354 static struct sock
*tcp_v4_cookie_check(struct sock
*sk
, struct sk_buff
*skb
)
1356 #ifdef CONFIG_SYN_COOKIES
1357 const struct tcphdr
*th
= tcp_hdr(skb
);
1360 sk
= cookie_v4_check(sk
, skb
);
1365 /* The socket must have it's spinlock held when we get
1366 * here, unless it is a TCP_LISTEN socket.
1368 * We have a potential double-lock case here, so even when
1369 * doing backlog processing we use the BH locking scheme.
1370 * This is because we cannot sleep with the original spinlock
1373 int tcp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
)
1377 if (sk
->sk_state
== TCP_ESTABLISHED
) { /* Fast path */
1378 struct dst_entry
*dst
= sk
->sk_rx_dst
;
1380 sock_rps_save_rxhash(sk
, skb
);
1381 sk_mark_napi_id(sk
, skb
);
1383 if (inet_sk(sk
)->rx_dst_ifindex
!= skb
->skb_iif
||
1384 !dst
->ops
->check(dst
, 0)) {
1386 sk
->sk_rx_dst
= NULL
;
1389 tcp_rcv_established(sk
, skb
, tcp_hdr(skb
), skb
->len
);
1393 if (tcp_checksum_complete(skb
))
1396 if (sk
->sk_state
== TCP_LISTEN
) {
1397 struct sock
*nsk
= tcp_v4_cookie_check(sk
, skb
);
1402 sock_rps_save_rxhash(nsk
, skb
);
1403 sk_mark_napi_id(nsk
, skb
);
1404 if (tcp_child_process(sk
, nsk
, skb
)) {
1411 sock_rps_save_rxhash(sk
, skb
);
1413 if (tcp_rcv_state_process(sk
, skb
)) {
1420 tcp_v4_send_reset(rsk
, skb
);
1423 /* Be careful here. If this function gets more complicated and
1424 * gcc suffers from register pressure on the x86, sk (in %ebx)
1425 * might be destroyed here. This current version compiles correctly,
1426 * but you have been warned.
1431 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_CSUMERRORS
);
1432 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_INERRS
);
1435 EXPORT_SYMBOL(tcp_v4_do_rcv
);
1437 void tcp_v4_early_demux(struct sk_buff
*skb
)
1439 const struct iphdr
*iph
;
1440 const struct tcphdr
*th
;
1443 if (skb
->pkt_type
!= PACKET_HOST
)
1446 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + sizeof(struct tcphdr
)))
1452 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1455 sk
= __inet_lookup_established(dev_net(skb
->dev
), &tcp_hashinfo
,
1456 iph
->saddr
, th
->source
,
1457 iph
->daddr
, ntohs(th
->dest
),
1461 skb
->destructor
= sock_edemux
;
1462 if (sk_fullsock(sk
)) {
1463 struct dst_entry
*dst
= READ_ONCE(sk
->sk_rx_dst
);
1466 dst
= dst_check(dst
, 0);
1468 inet_sk(sk
)->rx_dst_ifindex
== skb
->skb_iif
)
1469 skb_dst_set_noref(skb
, dst
);
1474 /* Packet is added to VJ-style prequeue for processing in process
1475 * context, if a reader task is waiting. Apparently, this exciting
1476 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
1477 * failed somewhere. Latency? Burstiness? Well, at least now we will
1478 * see, why it failed. 8)8) --ANK
1481 bool tcp_prequeue(struct sock
*sk
, struct sk_buff
*skb
)
1483 struct tcp_sock
*tp
= tcp_sk(sk
);
1485 if (sysctl_tcp_low_latency
|| !tp
->ucopy
.task
)
1488 if (skb
->len
<= tcp_hdrlen(skb
) &&
1489 skb_queue_len(&tp
->ucopy
.prequeue
) == 0)
1492 /* Before escaping RCU protected region, we need to take care of skb
1493 * dst. Prequeue is only enabled for established sockets.
1494 * For such sockets, we might need the skb dst only to set sk->sk_rx_dst
1495 * Instead of doing full sk_rx_dst validity here, let's perform
1496 * an optimistic check.
1498 if (likely(sk
->sk_rx_dst
))
1501 skb_dst_force_safe(skb
);
1503 __skb_queue_tail(&tp
->ucopy
.prequeue
, skb
);
1504 tp
->ucopy
.memory
+= skb
->truesize
;
1505 if (tp
->ucopy
.memory
> sk
->sk_rcvbuf
) {
1506 struct sk_buff
*skb1
;
1508 BUG_ON(sock_owned_by_user(sk
));
1510 while ((skb1
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
) {
1511 sk_backlog_rcv(sk
, skb1
);
1512 NET_INC_STATS_BH(sock_net(sk
),
1513 LINUX_MIB_TCPPREQUEUEDROPPED
);
1516 tp
->ucopy
.memory
= 0;
1517 } else if (skb_queue_len(&tp
->ucopy
.prequeue
) == 1) {
1518 wake_up_interruptible_sync_poll(sk_sleep(sk
),
1519 POLLIN
| POLLRDNORM
| POLLRDBAND
);
1520 if (!inet_csk_ack_scheduled(sk
))
1521 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_DACK
,
1522 (3 * tcp_rto_min(sk
)) / 4,
1527 EXPORT_SYMBOL(tcp_prequeue
);
1533 int tcp_v4_rcv(struct sk_buff
*skb
)
1535 const struct iphdr
*iph
;
1536 const struct tcphdr
*th
;
1539 struct net
*net
= dev_net(skb
->dev
);
1541 if (skb
->pkt_type
!= PACKET_HOST
)
1544 /* Count it even if it's bad */
1545 TCP_INC_STATS_BH(net
, TCP_MIB_INSEGS
);
1547 if (!pskb_may_pull(skb
, sizeof(struct tcphdr
)))
1552 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1554 if (!pskb_may_pull(skb
, th
->doff
* 4))
1557 /* An explanation is required here, I think.
1558 * Packet length and doff are validated by header prediction,
1559 * provided case of th->doff==0 is eliminated.
1560 * So, we defer the checks. */
1562 if (skb_checksum_init(skb
, IPPROTO_TCP
, inet_compute_pseudo
))
1567 /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
1568 * barrier() makes sure compiler wont play fool^Waliasing games.
1570 memmove(&TCP_SKB_CB(skb
)->header
.h4
, IPCB(skb
),
1571 sizeof(struct inet_skb_parm
));
1574 TCP_SKB_CB(skb
)->seq
= ntohl(th
->seq
);
1575 TCP_SKB_CB(skb
)->end_seq
= (TCP_SKB_CB(skb
)->seq
+ th
->syn
+ th
->fin
+
1576 skb
->len
- th
->doff
* 4);
1577 TCP_SKB_CB(skb
)->ack_seq
= ntohl(th
->ack_seq
);
1578 TCP_SKB_CB(skb
)->tcp_flags
= tcp_flag_byte(th
);
1579 TCP_SKB_CB(skb
)->tcp_tw_isn
= 0;
1580 TCP_SKB_CB(skb
)->ip_dsfield
= ipv4_get_dsfield(iph
);
1581 TCP_SKB_CB(skb
)->sacked
= 0;
1584 sk
= __inet_lookup_skb(&tcp_hashinfo
, skb
, th
->source
, th
->dest
);
1589 if (sk
->sk_state
== TCP_TIME_WAIT
)
1592 if (sk
->sk_state
== TCP_NEW_SYN_RECV
) {
1593 struct request_sock
*req
= inet_reqsk(sk
);
1594 struct sock
*nsk
= NULL
;
1596 sk
= req
->rsk_listener
;
1597 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1598 goto discard_and_relse
;
1599 if (likely(sk
->sk_state
== TCP_LISTEN
)) {
1600 nsk
= tcp_check_req(sk
, skb
, req
, false);
1602 inet_csk_reqsk_queue_drop_and_put(sk
, req
);
1612 } else if (tcp_child_process(sk
, nsk
, skb
)) {
1613 tcp_v4_send_reset(nsk
, skb
);
1619 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
1620 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
1621 goto discard_and_relse
;
1624 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
1625 goto discard_and_relse
;
1627 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1628 goto discard_and_relse
;
1632 if (sk_filter(sk
, skb
))
1633 goto discard_and_relse
;
1637 if (sk
->sk_state
== TCP_LISTEN
) {
1638 ret
= tcp_v4_do_rcv(sk
, skb
);
1639 goto put_and_return
;
1642 sk_incoming_cpu_update(sk
);
1644 bh_lock_sock_nested(sk
);
1645 tcp_sk(sk
)->segs_in
+= max_t(u16
, 1, skb_shinfo(skb
)->gso_segs
);
1647 if (!sock_owned_by_user(sk
)) {
1648 if (!tcp_prequeue(sk
, skb
))
1649 ret
= tcp_v4_do_rcv(sk
, skb
);
1650 } else if (unlikely(sk_add_backlog(sk
, skb
,
1651 sk
->sk_rcvbuf
+ sk
->sk_sndbuf
))) {
1653 NET_INC_STATS_BH(net
, LINUX_MIB_TCPBACKLOGDROP
);
1654 goto discard_and_relse
;
1664 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
1667 if (tcp_checksum_complete(skb
)) {
1669 TCP_INC_STATS_BH(net
, TCP_MIB_CSUMERRORS
);
1671 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
1673 tcp_v4_send_reset(NULL
, skb
);
1677 /* Discard frame. */
1686 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
)) {
1687 inet_twsk_put(inet_twsk(sk
));
1691 if (tcp_checksum_complete(skb
)) {
1692 inet_twsk_put(inet_twsk(sk
));
1695 switch (tcp_timewait_state_process(inet_twsk(sk
), skb
, th
)) {
1697 struct sock
*sk2
= inet_lookup_listener(dev_net(skb
->dev
),
1699 iph
->saddr
, th
->source
,
1700 iph
->daddr
, th
->dest
,
1703 inet_twsk_deschedule_put(inet_twsk(sk
));
1707 /* Fall through to ACK */
1710 tcp_v4_timewait_ack(sk
, skb
);
1713 tcp_v4_send_reset(sk
, skb
);
1714 inet_twsk_deschedule_put(inet_twsk(sk
));
1716 case TCP_TW_SUCCESS
:;
1721 static struct timewait_sock_ops tcp_timewait_sock_ops
= {
1722 .twsk_obj_size
= sizeof(struct tcp_timewait_sock
),
1723 .twsk_unique
= tcp_twsk_unique
,
1724 .twsk_destructor
= tcp_twsk_destructor
,
1727 void inet_sk_rx_dst_set(struct sock
*sk
, const struct sk_buff
*skb
)
1729 struct dst_entry
*dst
= skb_dst(skb
);
1731 if (dst
&& dst_hold_safe(dst
)) {
1732 sk
->sk_rx_dst
= dst
;
1733 inet_sk(sk
)->rx_dst_ifindex
= skb
->skb_iif
;
1736 EXPORT_SYMBOL(inet_sk_rx_dst_set
);
1738 const struct inet_connection_sock_af_ops ipv4_specific
= {
1739 .queue_xmit
= ip_queue_xmit
,
1740 .send_check
= tcp_v4_send_check
,
1741 .rebuild_header
= inet_sk_rebuild_header
,
1742 .sk_rx_dst_set
= inet_sk_rx_dst_set
,
1743 .conn_request
= tcp_v4_conn_request
,
1744 .syn_recv_sock
= tcp_v4_syn_recv_sock
,
1745 .net_header_len
= sizeof(struct iphdr
),
1746 .setsockopt
= ip_setsockopt
,
1747 .getsockopt
= ip_getsockopt
,
1748 .addr2sockaddr
= inet_csk_addr2sockaddr
,
1749 .sockaddr_len
= sizeof(struct sockaddr_in
),
1750 .bind_conflict
= inet_csk_bind_conflict
,
1751 #ifdef CONFIG_COMPAT
1752 .compat_setsockopt
= compat_ip_setsockopt
,
1753 .compat_getsockopt
= compat_ip_getsockopt
,
1755 .mtu_reduced
= tcp_v4_mtu_reduced
,
1757 EXPORT_SYMBOL(ipv4_specific
);
1759 #ifdef CONFIG_TCP_MD5SIG
1760 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific
= {
1761 .md5_lookup
= tcp_v4_md5_lookup
,
1762 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1763 .md5_parse
= tcp_v4_parse_md5_keys
,
1767 /* NOTE: A lot of things set to zero explicitly by call to
1768 * sk_alloc() so need not be done here.
1770 static int tcp_v4_init_sock(struct sock
*sk
)
1772 struct inet_connection_sock
*icsk
= inet_csk(sk
);
1776 icsk
->icsk_af_ops
= &ipv4_specific
;
1778 #ifdef CONFIG_TCP_MD5SIG
1779 tcp_sk(sk
)->af_specific
= &tcp_sock_ipv4_specific
;
1785 void tcp_v4_destroy_sock(struct sock
*sk
)
1787 struct tcp_sock
*tp
= tcp_sk(sk
);
1789 tcp_clear_xmit_timers(sk
);
1791 tcp_cleanup_congestion_control(sk
);
1793 /* Cleanup up the write buffer. */
1794 tcp_write_queue_purge(sk
);
1796 /* Cleans up our, hopefully empty, out_of_order_queue. */
1797 __skb_queue_purge(&tp
->out_of_order_queue
);
1799 #ifdef CONFIG_TCP_MD5SIG
1800 /* Clean up the MD5 key list, if any */
1801 if (tp
->md5sig_info
) {
1802 tcp_clear_md5_list(sk
);
1803 kfree_rcu(tp
->md5sig_info
, rcu
);
1804 tp
->md5sig_info
= NULL
;
1808 /* Clean prequeue, it must be empty really */
1809 __skb_queue_purge(&tp
->ucopy
.prequeue
);
1811 /* Clean up a referenced TCP bind bucket. */
1812 if (inet_csk(sk
)->icsk_bind_hash
)
1815 BUG_ON(tp
->fastopen_rsk
);
1817 /* If socket is aborted during connect operation */
1818 tcp_free_fastopen_req(tp
);
1819 tcp_saved_syn_free(tp
);
1821 sk_sockets_allocated_dec(sk
);
1823 if (mem_cgroup_sockets_enabled
&& sk
->sk_memcg
)
1824 sock_release_memcg(sk
);
1826 EXPORT_SYMBOL(tcp_v4_destroy_sock
);
1828 #ifdef CONFIG_PROC_FS
1829 /* Proc filesystem TCP sock list dumping. */
1832 * Get next listener socket follow cur. If cur is NULL, get first socket
1833 * starting from bucket given in st->bucket; when st->bucket is zero the
1834 * very first socket in the hash table is returned.
1836 static void *listening_get_next(struct seq_file
*seq
, void *cur
)
1838 struct inet_connection_sock
*icsk
;
1839 struct hlist_nulls_node
*node
;
1840 struct sock
*sk
= cur
;
1841 struct inet_listen_hashbucket
*ilb
;
1842 struct tcp_iter_state
*st
= seq
->private;
1843 struct net
*net
= seq_file_net(seq
);
1846 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1847 spin_lock_bh(&ilb
->lock
);
1848 sk
= sk_nulls_head(&ilb
->head
);
1852 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1856 sk
= sk_nulls_next(sk
);
1858 sk_nulls_for_each_from(sk
, node
) {
1859 if (!net_eq(sock_net(sk
), net
))
1861 if (sk
->sk_family
== st
->family
) {
1865 icsk
= inet_csk(sk
);
1867 spin_unlock_bh(&ilb
->lock
);
1869 if (++st
->bucket
< INET_LHTABLE_SIZE
) {
1870 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1871 spin_lock_bh(&ilb
->lock
);
1872 sk
= sk_nulls_head(&ilb
->head
);
1880 static void *listening_get_idx(struct seq_file
*seq
, loff_t
*pos
)
1882 struct tcp_iter_state
*st
= seq
->private;
1887 rc
= listening_get_next(seq
, NULL
);
1889 while (rc
&& *pos
) {
1890 rc
= listening_get_next(seq
, rc
);
1896 static inline bool empty_bucket(const struct tcp_iter_state
*st
)
1898 return hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].chain
);
1902 * Get first established socket starting from bucket given in st->bucket.
1903 * If st->bucket is zero, the very first socket in the hash is returned.
1905 static void *established_get_first(struct seq_file
*seq
)
1907 struct tcp_iter_state
*st
= seq
->private;
1908 struct net
*net
= seq_file_net(seq
);
1912 for (; st
->bucket
<= tcp_hashinfo
.ehash_mask
; ++st
->bucket
) {
1914 struct hlist_nulls_node
*node
;
1915 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
);
1917 /* Lockless fast path for the common case of empty buckets */
1918 if (empty_bucket(st
))
1922 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[st
->bucket
].chain
) {
1923 if (sk
->sk_family
!= st
->family
||
1924 !net_eq(sock_net(sk
), net
)) {
1930 spin_unlock_bh(lock
);
1936 static void *established_get_next(struct seq_file
*seq
, void *cur
)
1938 struct sock
*sk
= cur
;
1939 struct hlist_nulls_node
*node
;
1940 struct tcp_iter_state
*st
= seq
->private;
1941 struct net
*net
= seq_file_net(seq
);
1946 sk
= sk_nulls_next(sk
);
1948 sk_nulls_for_each_from(sk
, node
) {
1949 if (sk
->sk_family
== st
->family
&& net_eq(sock_net(sk
), net
))
1953 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
1955 return established_get_first(seq
);
1958 static void *established_get_idx(struct seq_file
*seq
, loff_t pos
)
1960 struct tcp_iter_state
*st
= seq
->private;
1964 rc
= established_get_first(seq
);
1967 rc
= established_get_next(seq
, rc
);
1973 static void *tcp_get_idx(struct seq_file
*seq
, loff_t pos
)
1976 struct tcp_iter_state
*st
= seq
->private;
1978 st
->state
= TCP_SEQ_STATE_LISTENING
;
1979 rc
= listening_get_idx(seq
, &pos
);
1982 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
1983 rc
= established_get_idx(seq
, pos
);
1989 static void *tcp_seek_last_pos(struct seq_file
*seq
)
1991 struct tcp_iter_state
*st
= seq
->private;
1992 int offset
= st
->offset
;
1993 int orig_num
= st
->num
;
1996 switch (st
->state
) {
1997 case TCP_SEQ_STATE_LISTENING
:
1998 if (st
->bucket
>= INET_LHTABLE_SIZE
)
2000 st
->state
= TCP_SEQ_STATE_LISTENING
;
2001 rc
= listening_get_next(seq
, NULL
);
2002 while (offset
-- && rc
)
2003 rc
= listening_get_next(seq
, rc
);
2007 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2009 case TCP_SEQ_STATE_ESTABLISHED
:
2010 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2012 rc
= established_get_first(seq
);
2013 while (offset
-- && rc
)
2014 rc
= established_get_next(seq
, rc
);
2022 static void *tcp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2024 struct tcp_iter_state
*st
= seq
->private;
2027 if (*pos
&& *pos
== st
->last_pos
) {
2028 rc
= tcp_seek_last_pos(seq
);
2033 st
->state
= TCP_SEQ_STATE_LISTENING
;
2037 rc
= *pos
? tcp_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2040 st
->last_pos
= *pos
;
2044 static void *tcp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2046 struct tcp_iter_state
*st
= seq
->private;
2049 if (v
== SEQ_START_TOKEN
) {
2050 rc
= tcp_get_idx(seq
, 0);
2054 switch (st
->state
) {
2055 case TCP_SEQ_STATE_LISTENING
:
2056 rc
= listening_get_next(seq
, v
);
2058 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2061 rc
= established_get_first(seq
);
2064 case TCP_SEQ_STATE_ESTABLISHED
:
2065 rc
= established_get_next(seq
, v
);
2070 st
->last_pos
= *pos
;
2074 static void tcp_seq_stop(struct seq_file
*seq
, void *v
)
2076 struct tcp_iter_state
*st
= seq
->private;
2078 switch (st
->state
) {
2079 case TCP_SEQ_STATE_LISTENING
:
2080 if (v
!= SEQ_START_TOKEN
)
2081 spin_unlock_bh(&tcp_hashinfo
.listening_hash
[st
->bucket
].lock
);
2083 case TCP_SEQ_STATE_ESTABLISHED
:
2085 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2090 int tcp_seq_open(struct inode
*inode
, struct file
*file
)
2092 struct tcp_seq_afinfo
*afinfo
= PDE_DATA(inode
);
2093 struct tcp_iter_state
*s
;
2096 err
= seq_open_net(inode
, file
, &afinfo
->seq_ops
,
2097 sizeof(struct tcp_iter_state
));
2101 s
= ((struct seq_file
*)file
->private_data
)->private;
2102 s
->family
= afinfo
->family
;
2106 EXPORT_SYMBOL(tcp_seq_open
);
2108 int tcp_proc_register(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2111 struct proc_dir_entry
*p
;
2113 afinfo
->seq_ops
.start
= tcp_seq_start
;
2114 afinfo
->seq_ops
.next
= tcp_seq_next
;
2115 afinfo
->seq_ops
.stop
= tcp_seq_stop
;
2117 p
= proc_create_data(afinfo
->name
, S_IRUGO
, net
->proc_net
,
2118 afinfo
->seq_fops
, afinfo
);
2123 EXPORT_SYMBOL(tcp_proc_register
);
2125 void tcp_proc_unregister(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2127 remove_proc_entry(afinfo
->name
, net
->proc_net
);
2129 EXPORT_SYMBOL(tcp_proc_unregister
);
2131 static void get_openreq4(const struct request_sock
*req
,
2132 struct seq_file
*f
, int i
)
2134 const struct inet_request_sock
*ireq
= inet_rsk(req
);
2135 long delta
= req
->rsk_timer
.expires
- jiffies
;
2137 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2138 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK",
2143 ntohs(ireq
->ir_rmt_port
),
2145 0, 0, /* could print option size, but that is af dependent. */
2146 1, /* timers active (only the expire timer) */
2147 jiffies_delta_to_clock_t(delta
),
2149 from_kuid_munged(seq_user_ns(f
),
2150 sock_i_uid(req
->rsk_listener
)),
2151 0, /* non standard timer */
2152 0, /* open_requests have no inode */
2157 static void get_tcp4_sock(struct sock
*sk
, struct seq_file
*f
, int i
)
2160 unsigned long timer_expires
;
2161 const struct tcp_sock
*tp
= tcp_sk(sk
);
2162 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2163 const struct inet_sock
*inet
= inet_sk(sk
);
2164 const struct fastopen_queue
*fastopenq
= &icsk
->icsk_accept_queue
.fastopenq
;
2165 __be32 dest
= inet
->inet_daddr
;
2166 __be32 src
= inet
->inet_rcv_saddr
;
2167 __u16 destp
= ntohs(inet
->inet_dport
);
2168 __u16 srcp
= ntohs(inet
->inet_sport
);
2172 if (icsk
->icsk_pending
== ICSK_TIME_RETRANS
||
2173 icsk
->icsk_pending
== ICSK_TIME_EARLY_RETRANS
||
2174 icsk
->icsk_pending
== ICSK_TIME_LOSS_PROBE
) {
2176 timer_expires
= icsk
->icsk_timeout
;
2177 } else if (icsk
->icsk_pending
== ICSK_TIME_PROBE0
) {
2179 timer_expires
= icsk
->icsk_timeout
;
2180 } else if (timer_pending(&sk
->sk_timer
)) {
2182 timer_expires
= sk
->sk_timer
.expires
;
2185 timer_expires
= jiffies
;
2188 state
= sk_state_load(sk
);
2189 if (state
== TCP_LISTEN
)
2190 rx_queue
= sk
->sk_ack_backlog
;
2192 /* Because we don't lock the socket,
2193 * we might find a transient negative value.
2195 rx_queue
= max_t(int, tp
->rcv_nxt
- tp
->copied_seq
, 0);
2197 seq_printf(f
, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2198 "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d",
2199 i
, src
, srcp
, dest
, destp
, state
,
2200 tp
->write_seq
- tp
->snd_una
,
2203 jiffies_delta_to_clock_t(timer_expires
- jiffies
),
2204 icsk
->icsk_retransmits
,
2205 from_kuid_munged(seq_user_ns(f
), sock_i_uid(sk
)),
2206 icsk
->icsk_probes_out
,
2208 atomic_read(&sk
->sk_refcnt
), sk
,
2209 jiffies_to_clock_t(icsk
->icsk_rto
),
2210 jiffies_to_clock_t(icsk
->icsk_ack
.ato
),
2211 (icsk
->icsk_ack
.quick
<< 1) | icsk
->icsk_ack
.pingpong
,
2213 state
== TCP_LISTEN
?
2214 fastopenq
->max_qlen
:
2215 (tcp_in_initial_slowstart(tp
) ? -1 : tp
->snd_ssthresh
));
2218 static void get_timewait4_sock(const struct inet_timewait_sock
*tw
,
2219 struct seq_file
*f
, int i
)
2221 long delta
= tw
->tw_timer
.expires
- jiffies
;
2225 dest
= tw
->tw_daddr
;
2226 src
= tw
->tw_rcv_saddr
;
2227 destp
= ntohs(tw
->tw_dport
);
2228 srcp
= ntohs(tw
->tw_sport
);
2230 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2231 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK",
2232 i
, src
, srcp
, dest
, destp
, tw
->tw_substate
, 0, 0,
2233 3, jiffies_delta_to_clock_t(delta
), 0, 0, 0, 0,
2234 atomic_read(&tw
->tw_refcnt
), tw
);
2239 static int tcp4_seq_show(struct seq_file
*seq
, void *v
)
2241 struct tcp_iter_state
*st
;
2242 struct sock
*sk
= v
;
2244 seq_setwidth(seq
, TMPSZ
- 1);
2245 if (v
== SEQ_START_TOKEN
) {
2246 seq_puts(seq
, " sl local_address rem_address st tx_queue "
2247 "rx_queue tr tm->when retrnsmt uid timeout "
2253 if (sk
->sk_state
== TCP_TIME_WAIT
)
2254 get_timewait4_sock(v
, seq
, st
->num
);
2255 else if (sk
->sk_state
== TCP_NEW_SYN_RECV
)
2256 get_openreq4(v
, seq
, st
->num
);
2258 get_tcp4_sock(v
, seq
, st
->num
);
2264 static const struct file_operations tcp_afinfo_seq_fops
= {
2265 .owner
= THIS_MODULE
,
2266 .open
= tcp_seq_open
,
2268 .llseek
= seq_lseek
,
2269 .release
= seq_release_net
2272 static struct tcp_seq_afinfo tcp4_seq_afinfo
= {
2275 .seq_fops
= &tcp_afinfo_seq_fops
,
2277 .show
= tcp4_seq_show
,
2281 static int __net_init
tcp4_proc_init_net(struct net
*net
)
2283 return tcp_proc_register(net
, &tcp4_seq_afinfo
);
2286 static void __net_exit
tcp4_proc_exit_net(struct net
*net
)
2288 tcp_proc_unregister(net
, &tcp4_seq_afinfo
);
2291 static struct pernet_operations tcp4_net_ops
= {
2292 .init
= tcp4_proc_init_net
,
2293 .exit
= tcp4_proc_exit_net
,
2296 int __init
tcp4_proc_init(void)
2298 return register_pernet_subsys(&tcp4_net_ops
);
2301 void tcp4_proc_exit(void)
2303 unregister_pernet_subsys(&tcp4_net_ops
);
2305 #endif /* CONFIG_PROC_FS */
2307 struct proto tcp_prot
= {
2309 .owner
= THIS_MODULE
,
2311 .connect
= tcp_v4_connect
,
2312 .disconnect
= tcp_disconnect
,
2313 .accept
= inet_csk_accept
,
2315 .init
= tcp_v4_init_sock
,
2316 .destroy
= tcp_v4_destroy_sock
,
2317 .shutdown
= tcp_shutdown
,
2318 .setsockopt
= tcp_setsockopt
,
2319 .getsockopt
= tcp_getsockopt
,
2320 .recvmsg
= tcp_recvmsg
,
2321 .sendmsg
= tcp_sendmsg
,
2322 .sendpage
= tcp_sendpage
,
2323 .backlog_rcv
= tcp_v4_do_rcv
,
2324 .release_cb
= tcp_release_cb
,
2326 .unhash
= inet_unhash
,
2327 .get_port
= inet_csk_get_port
,
2328 .enter_memory_pressure
= tcp_enter_memory_pressure
,
2329 .stream_memory_free
= tcp_stream_memory_free
,
2330 .sockets_allocated
= &tcp_sockets_allocated
,
2331 .orphan_count
= &tcp_orphan_count
,
2332 .memory_allocated
= &tcp_memory_allocated
,
2333 .memory_pressure
= &tcp_memory_pressure
,
2334 .sysctl_mem
= sysctl_tcp_mem
,
2335 .sysctl_wmem
= sysctl_tcp_wmem
,
2336 .sysctl_rmem
= sysctl_tcp_rmem
,
2337 .max_header
= MAX_TCP_HEADER
,
2338 .obj_size
= sizeof(struct tcp_sock
),
2339 .slab_flags
= SLAB_DESTROY_BY_RCU
,
2340 .twsk_prot
= &tcp_timewait_sock_ops
,
2341 .rsk_prot
= &tcp_request_sock_ops
,
2342 .h
.hashinfo
= &tcp_hashinfo
,
2343 .no_autobind
= true,
2344 #ifdef CONFIG_COMPAT
2345 .compat_setsockopt
= compat_tcp_setsockopt
,
2346 .compat_getsockopt
= compat_tcp_getsockopt
,
2348 .diag_destroy
= tcp_abort
,
2350 EXPORT_SYMBOL(tcp_prot
);
2352 static void __net_exit
tcp_sk_exit(struct net
*net
)
2356 for_each_possible_cpu(cpu
)
2357 inet_ctl_sock_destroy(*per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
));
2358 free_percpu(net
->ipv4
.tcp_sk
);
2361 static int __net_init
tcp_sk_init(struct net
*net
)
2365 net
->ipv4
.tcp_sk
= alloc_percpu(struct sock
*);
2366 if (!net
->ipv4
.tcp_sk
)
2369 for_each_possible_cpu(cpu
) {
2372 res
= inet_ctl_sock_create(&sk
, PF_INET
, SOCK_RAW
,
2376 *per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
) = sk
;
2379 net
->ipv4
.sysctl_tcp_ecn
= 2;
2380 net
->ipv4
.sysctl_tcp_ecn_fallback
= 1;
2382 net
->ipv4
.sysctl_tcp_base_mss
= TCP_BASE_MSS
;
2383 net
->ipv4
.sysctl_tcp_probe_threshold
= TCP_PROBE_THRESHOLD
;
2384 net
->ipv4
.sysctl_tcp_probe_interval
= TCP_PROBE_INTERVAL
;
2386 net
->ipv4
.sysctl_tcp_keepalive_time
= TCP_KEEPALIVE_TIME
;
2387 net
->ipv4
.sysctl_tcp_keepalive_probes
= TCP_KEEPALIVE_PROBES
;
2388 net
->ipv4
.sysctl_tcp_keepalive_intvl
= TCP_KEEPALIVE_INTVL
;
2390 net
->ipv4
.sysctl_tcp_syn_retries
= TCP_SYN_RETRIES
;
2391 net
->ipv4
.sysctl_tcp_synack_retries
= TCP_SYNACK_RETRIES
;
2392 net
->ipv4
.sysctl_tcp_syncookies
= 1;
2393 net
->ipv4
.sysctl_tcp_reordering
= TCP_FASTRETRANS_THRESH
;
2394 net
->ipv4
.sysctl_tcp_retries1
= TCP_RETR1
;
2395 net
->ipv4
.sysctl_tcp_retries2
= TCP_RETR2
;
2396 net
->ipv4
.sysctl_tcp_orphan_retries
= 0;
2397 net
->ipv4
.sysctl_tcp_fin_timeout
= TCP_FIN_TIMEOUT
;
2398 net
->ipv4
.sysctl_tcp_notsent_lowat
= UINT_MAX
;
2407 static void __net_exit
tcp_sk_exit_batch(struct list_head
*net_exit_list
)
2409 inet_twsk_purge(&tcp_hashinfo
, &tcp_death_row
, AF_INET
);
2412 static struct pernet_operations __net_initdata tcp_sk_ops
= {
2413 .init
= tcp_sk_init
,
2414 .exit
= tcp_sk_exit
,
2415 .exit_batch
= tcp_sk_exit_batch
,
2418 void __init
tcp_v4_init(void)
2420 inet_hashinfo_init(&tcp_hashinfo
);
2421 if (register_pernet_subsys(&tcp_sk_ops
))
2422 panic("Failed to create the TCP control socket.\n");