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/netdma.h>
76 #include <net/secure_seq.h>
77 #include <net/tcp_memcontrol.h>
79 #include <linux/inet.h>
80 #include <linux/ipv6.h>
81 #include <linux/stddef.h>
82 #include <linux/proc_fs.h>
83 #include <linux/seq_file.h>
85 #include <linux/crypto.h>
86 #include <linux/scatterlist.h>
88 int sysctl_tcp_tw_reuse __read_mostly
;
89 int sysctl_tcp_low_latency __read_mostly
;
90 EXPORT_SYMBOL(sysctl_tcp_low_latency
);
93 #ifdef CONFIG_TCP_MD5SIG
94 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
95 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
);
98 struct inet_hashinfo tcp_hashinfo
;
99 EXPORT_SYMBOL(tcp_hashinfo
);
101 static inline __u32
tcp_v4_init_sequence(const struct sk_buff
*skb
)
103 return secure_tcp_sequence_number(ip_hdr(skb
)->daddr
,
106 tcp_hdr(skb
)->source
);
109 int tcp_twsk_unique(struct sock
*sk
, struct sock
*sktw
, void *twp
)
111 const struct tcp_timewait_sock
*tcptw
= tcp_twsk(sktw
);
112 struct tcp_sock
*tp
= tcp_sk(sk
);
114 /* With PAWS, it is safe from the viewpoint
115 of data integrity. Even without PAWS it is safe provided sequence
116 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
118 Actually, the idea is close to VJ's one, only timestamp cache is
119 held not per host, but per port pair and TW bucket is used as state
122 If TW bucket has been already destroyed we fall back to VJ's scheme
123 and use initial timestamp retrieved from peer table.
125 if (tcptw
->tw_ts_recent_stamp
&&
126 (twp
== NULL
|| (sysctl_tcp_tw_reuse
&&
127 get_seconds() - tcptw
->tw_ts_recent_stamp
> 1))) {
128 tp
->write_seq
= tcptw
->tw_snd_nxt
+ 65535 + 2;
129 if (tp
->write_seq
== 0)
131 tp
->rx_opt
.ts_recent
= tcptw
->tw_ts_recent
;
132 tp
->rx_opt
.ts_recent_stamp
= tcptw
->tw_ts_recent_stamp
;
139 EXPORT_SYMBOL_GPL(tcp_twsk_unique
);
141 /* This will initiate an outgoing connection. */
142 int tcp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
)
144 struct sockaddr_in
*usin
= (struct sockaddr_in
*)uaddr
;
145 struct inet_sock
*inet
= inet_sk(sk
);
146 struct tcp_sock
*tp
= tcp_sk(sk
);
147 __be16 orig_sport
, orig_dport
;
148 __be32 daddr
, nexthop
;
152 struct ip_options_rcu
*inet_opt
;
154 if (addr_len
< sizeof(struct sockaddr_in
))
157 if (usin
->sin_family
!= AF_INET
)
158 return -EAFNOSUPPORT
;
160 nexthop
= daddr
= usin
->sin_addr
.s_addr
;
161 inet_opt
= rcu_dereference_protected(inet
->inet_opt
,
162 sock_owned_by_user(sk
));
163 if (inet_opt
&& inet_opt
->opt
.srr
) {
166 nexthop
= inet_opt
->opt
.faddr
;
169 orig_sport
= inet
->inet_sport
;
170 orig_dport
= usin
->sin_port
;
171 fl4
= &inet
->cork
.fl
.u
.ip4
;
172 rt
= ip_route_connect(fl4
, nexthop
, inet
->inet_saddr
,
173 RT_CONN_FLAGS(sk
), sk
->sk_bound_dev_if
,
175 orig_sport
, orig_dport
, sk
, true);
178 if (err
== -ENETUNREACH
)
179 IP_INC_STATS_BH(sock_net(sk
), IPSTATS_MIB_OUTNOROUTES
);
183 if (rt
->rt_flags
& (RTCF_MULTICAST
| RTCF_BROADCAST
)) {
188 if (!inet_opt
|| !inet_opt
->opt
.srr
)
191 if (!inet
->inet_saddr
)
192 inet
->inet_saddr
= fl4
->saddr
;
193 inet
->inet_rcv_saddr
= inet
->inet_saddr
;
195 if (tp
->rx_opt
.ts_recent_stamp
&& inet
->inet_daddr
!= daddr
) {
196 /* Reset inherited state */
197 tp
->rx_opt
.ts_recent
= 0;
198 tp
->rx_opt
.ts_recent_stamp
= 0;
199 if (likely(!tp
->repair
))
203 if (tcp_death_row
.sysctl_tw_recycle
&&
204 !tp
->rx_opt
.ts_recent_stamp
&& fl4
->daddr
== daddr
)
205 tcp_fetch_timewait_stamp(sk
, &rt
->dst
);
207 inet
->inet_dport
= usin
->sin_port
;
208 inet
->inet_daddr
= daddr
;
210 inet_csk(sk
)->icsk_ext_hdr_len
= 0;
212 inet_csk(sk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
214 tp
->rx_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
216 /* Socket identity is still unknown (sport may be zero).
217 * However we set state to SYN-SENT and not releasing socket
218 * lock select source port, enter ourselves into the hash tables and
219 * complete initialization after this.
221 tcp_set_state(sk
, TCP_SYN_SENT
);
222 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 static 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 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
278 * send out by Linux are always <576bytes so they should go through
281 if (sk
->sk_state
== TCP_LISTEN
)
284 dst
= inet_csk_update_pmtu(sk
, mtu
);
288 /* Something is about to be wrong... Remember soft error
289 * for the case, if this connection will not able to recover.
291 if (mtu
< dst_mtu(dst
) && ip_dont_fragment(sk
, dst
))
292 sk
->sk_err_soft
= EMSGSIZE
;
296 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
&&
297 inet_csk(sk
)->icsk_pmtu_cookie
> mtu
) {
298 tcp_sync_mss(sk
, mtu
);
300 /* Resend the TCP packet because it's
301 * clear that the old packet has been
302 * dropped. This is the new "fast" path mtu
305 tcp_simple_retransmit(sk
);
306 } /* else let the usual retransmit timer handle it */
309 static void do_redirect(struct sk_buff
*skb
, struct sock
*sk
)
311 struct dst_entry
*dst
= __sk_dst_check(sk
, 0);
314 dst
->ops
->redirect(dst
, sk
, skb
);
318 * This routine is called by the ICMP module when it gets some
319 * sort of error condition. If err < 0 then the socket should
320 * be closed and the error returned to the user. If err > 0
321 * it's just the icmp type << 8 | icmp code. After adjustment
322 * header points to the first 8 bytes of the tcp header. We need
323 * to find the appropriate port.
325 * The locking strategy used here is very "optimistic". When
326 * someone else accesses the socket the ICMP is just dropped
327 * and for some paths there is no check at all.
328 * A more general error queue to queue errors for later handling
329 * is probably better.
333 void tcp_v4_err(struct sk_buff
*icmp_skb
, u32 info
)
335 const struct iphdr
*iph
= (const struct iphdr
*)icmp_skb
->data
;
336 struct tcphdr
*th
= (struct tcphdr
*)(icmp_skb
->data
+ (iph
->ihl
<< 2));
337 struct inet_connection_sock
*icsk
;
339 struct inet_sock
*inet
;
340 const int type
= icmp_hdr(icmp_skb
)->type
;
341 const int code
= icmp_hdr(icmp_skb
)->code
;
344 struct request_sock
*req
;
348 struct net
*net
= dev_net(icmp_skb
->dev
);
350 if (icmp_skb
->len
< (iph
->ihl
<< 2) + 8) {
351 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
355 sk
= inet_lookup(net
, &tcp_hashinfo
, iph
->daddr
, th
->dest
,
356 iph
->saddr
, th
->source
, inet_iif(icmp_skb
));
358 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
361 if (sk
->sk_state
== TCP_TIME_WAIT
) {
362 inet_twsk_put(inet_twsk(sk
));
367 /* If too many ICMPs get dropped on busy
368 * servers this needs to be solved differently.
369 * We do take care of PMTU discovery (RFC1191) special case :
370 * we can receive locally generated ICMP messages while socket is held.
372 if (sock_owned_by_user(sk
)) {
373 if (!(type
== ICMP_DEST_UNREACH
&& code
== ICMP_FRAG_NEEDED
))
374 NET_INC_STATS_BH(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
376 if (sk
->sk_state
== TCP_CLOSE
)
379 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
380 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
386 req
= tp
->fastopen_rsk
;
387 seq
= ntohl(th
->seq
);
388 if (sk
->sk_state
!= TCP_LISTEN
&&
389 !between(seq
, tp
->snd_una
, tp
->snd_nxt
) &&
390 (req
== NULL
|| seq
!= tcp_rsk(req
)->snt_isn
)) {
391 /* For a Fast Open socket, allow seq to be snt_isn. */
392 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
398 do_redirect(icmp_skb
, sk
);
400 case ICMP_SOURCE_QUENCH
:
401 /* Just silently ignore these. */
403 case ICMP_PARAMETERPROB
:
406 case ICMP_DEST_UNREACH
:
407 if (code
> NR_ICMP_UNREACH
)
410 if (code
== ICMP_FRAG_NEEDED
) { /* PMTU discovery (RFC1191) */
412 if (!sock_owned_by_user(sk
)) {
413 tcp_v4_mtu_reduced(sk
);
415 if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED
, &tp
->tsq_flags
))
421 err
= icmp_err_convert
[code
].errno
;
422 /* check if icmp_skb allows revert of backoff
423 * (see draft-zimmermann-tcp-lcd) */
424 if (code
!= ICMP_NET_UNREACH
&& code
!= ICMP_HOST_UNREACH
)
426 if (seq
!= tp
->snd_una
|| !icsk
->icsk_retransmits
||
430 /* XXX (TFO) - revisit the following logic for TFO */
432 if (sock_owned_by_user(sk
))
435 icsk
->icsk_backoff
--;
436 inet_csk(sk
)->icsk_rto
= (tp
->srtt
? __tcp_set_rto(tp
) :
437 TCP_TIMEOUT_INIT
) << icsk
->icsk_backoff
;
440 skb
= tcp_write_queue_head(sk
);
443 remaining
= icsk
->icsk_rto
- min(icsk
->icsk_rto
,
444 tcp_time_stamp
- TCP_SKB_CB(skb
)->when
);
447 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
448 remaining
, TCP_RTO_MAX
);
450 /* RTO revert clocked out retransmission.
451 * Will retransmit now */
452 tcp_retransmit_timer(sk
);
456 case ICMP_TIME_EXCEEDED
:
463 /* XXX (TFO) - if it's a TFO socket and has been accepted, rather
464 * than following the TCP_SYN_RECV case and closing the socket,
465 * we ignore the ICMP error and keep trying like a fully established
466 * socket. Is this the right thing to do?
468 if (req
&& req
->sk
== NULL
)
471 switch (sk
->sk_state
) {
472 struct request_sock
*req
, **prev
;
474 if (sock_owned_by_user(sk
))
477 req
= inet_csk_search_req(sk
, &prev
, th
->dest
,
478 iph
->daddr
, iph
->saddr
);
482 /* ICMPs are not backlogged, hence we cannot get
483 an established socket here.
487 if (seq
!= tcp_rsk(req
)->snt_isn
) {
488 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
493 * Still in SYN_RECV, just remove it silently.
494 * There is no good way to pass the error to the newly
495 * created socket, and POSIX does not want network
496 * errors returned from accept().
498 inet_csk_reqsk_queue_drop(sk
, req
, prev
);
499 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
503 case TCP_SYN_RECV
: /* Cannot happen.
504 It can f.e. if SYNs crossed,
507 if (!sock_owned_by_user(sk
)) {
510 sk
->sk_error_report(sk
);
514 sk
->sk_err_soft
= err
;
519 /* If we've already connected we will keep trying
520 * until we time out, or the user gives up.
522 * rfc1122 4.2.3.9 allows to consider as hard errors
523 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
524 * but it is obsoleted by pmtu discovery).
526 * Note, that in modern internet, where routing is unreliable
527 * and in each dark corner broken firewalls sit, sending random
528 * errors ordered by their masters even this two messages finally lose
529 * their original sense (even Linux sends invalid PORT_UNREACHs)
531 * Now we are in compliance with RFCs.
536 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
538 sk
->sk_error_report(sk
);
539 } else { /* Only an error on timeout */
540 sk
->sk_err_soft
= err
;
548 static void __tcp_v4_send_check(struct sk_buff
*skb
,
549 __be32 saddr
, __be32 daddr
)
551 struct tcphdr
*th
= tcp_hdr(skb
);
553 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
554 th
->check
= ~tcp_v4_check(skb
->len
, saddr
, daddr
, 0);
555 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
556 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
558 th
->check
= tcp_v4_check(skb
->len
, saddr
, daddr
,
565 /* This routine computes an IPv4 TCP checksum. */
566 void tcp_v4_send_check(struct sock
*sk
, struct sk_buff
*skb
)
568 const struct inet_sock
*inet
= inet_sk(sk
);
570 __tcp_v4_send_check(skb
, inet
->inet_saddr
, inet
->inet_daddr
);
572 EXPORT_SYMBOL(tcp_v4_send_check
);
574 int tcp_v4_gso_send_check(struct sk_buff
*skb
)
576 const struct iphdr
*iph
;
579 if (!pskb_may_pull(skb
, sizeof(*th
)))
586 skb
->ip_summed
= CHECKSUM_PARTIAL
;
587 __tcp_v4_send_check(skb
, iph
->saddr
, iph
->daddr
);
592 * This routine will send an RST to the other tcp.
594 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
596 * Answer: if a packet caused RST, it is not for a socket
597 * existing in our system, if it is matched to a socket,
598 * it is just duplicate segment or bug in other side's TCP.
599 * So that we build reply only basing on parameters
600 * arrived with segment.
601 * Exception: precedence violation. We do not implement it in any case.
604 static void tcp_v4_send_reset(struct sock
*sk
, struct sk_buff
*skb
)
606 const struct tcphdr
*th
= tcp_hdr(skb
);
609 #ifdef CONFIG_TCP_MD5SIG
610 __be32 opt
[(TCPOLEN_MD5SIG_ALIGNED
>> 2)];
613 struct ip_reply_arg arg
;
614 #ifdef CONFIG_TCP_MD5SIG
615 struct tcp_md5sig_key
*key
;
616 const __u8
*hash_location
= NULL
;
617 unsigned char newhash
[16];
619 struct sock
*sk1
= NULL
;
623 /* Never send a reset in response to a reset. */
627 if (skb_rtable(skb
)->rt_type
!= RTN_LOCAL
)
630 /* Swap the send and the receive. */
631 memset(&rep
, 0, sizeof(rep
));
632 rep
.th
.dest
= th
->source
;
633 rep
.th
.source
= th
->dest
;
634 rep
.th
.doff
= sizeof(struct tcphdr
) / 4;
638 rep
.th
.seq
= th
->ack_seq
;
641 rep
.th
.ack_seq
= htonl(ntohl(th
->seq
) + th
->syn
+ th
->fin
+
642 skb
->len
- (th
->doff
<< 2));
645 memset(&arg
, 0, sizeof(arg
));
646 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
647 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
649 #ifdef CONFIG_TCP_MD5SIG
650 hash_location
= tcp_parse_md5sig_option(th
);
651 if (!sk
&& hash_location
) {
653 * active side is lost. Try to find listening socket through
654 * source port, and then find md5 key through listening socket.
655 * we are not loose security here:
656 * Incoming packet is checked with md5 hash with finding key,
657 * no RST generated if md5 hash doesn't match.
659 sk1
= __inet_lookup_listener(dev_net(skb_dst(skb
)->dev
),
660 &tcp_hashinfo
, ip_hdr(skb
)->saddr
,
661 th
->source
, ip_hdr(skb
)->daddr
,
662 ntohs(th
->source
), inet_iif(skb
));
663 /* don't send rst if it can't find key */
667 key
= tcp_md5_do_lookup(sk1
, (union tcp_md5_addr
*)
668 &ip_hdr(skb
)->saddr
, AF_INET
);
672 genhash
= tcp_v4_md5_hash_skb(newhash
, key
, NULL
, NULL
, skb
);
673 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0)
676 key
= sk
? tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)
682 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) |
684 (TCPOPT_MD5SIG
<< 8) |
686 /* Update length and the length the header thinks exists */
687 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
688 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
690 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[1],
691 key
, ip_hdr(skb
)->saddr
,
692 ip_hdr(skb
)->daddr
, &rep
.th
);
695 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
696 ip_hdr(skb
)->saddr
, /* XXX */
697 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
698 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
699 arg
.flags
= (sk
&& inet_sk(sk
)->transparent
) ? IP_REPLY_ARG_NOSRCCHECK
: 0;
700 /* When socket is gone, all binding information is lost.
701 * routing might fail in this case. No choice here, if we choose to force
702 * input interface, we will misroute in case of asymmetric route.
705 arg
.bound_dev_if
= sk
->sk_bound_dev_if
;
707 net
= dev_net(skb_dst(skb
)->dev
);
708 arg
.tos
= ip_hdr(skb
)->tos
;
709 ip_send_unicast_reply(net
, skb
, ip_hdr(skb
)->saddr
,
710 ip_hdr(skb
)->daddr
, &arg
, arg
.iov
[0].iov_len
);
712 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
713 TCP_INC_STATS_BH(net
, TCP_MIB_OUTRSTS
);
715 #ifdef CONFIG_TCP_MD5SIG
724 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
725 outside socket context is ugly, certainly. What can I do?
728 static void tcp_v4_send_ack(struct sk_buff
*skb
, u32 seq
, u32 ack
,
729 u32 win
, u32 tsval
, u32 tsecr
, int oif
,
730 struct tcp_md5sig_key
*key
,
731 int reply_flags
, u8 tos
)
733 const struct tcphdr
*th
= tcp_hdr(skb
);
736 __be32 opt
[(TCPOLEN_TSTAMP_ALIGNED
>> 2)
737 #ifdef CONFIG_TCP_MD5SIG
738 + (TCPOLEN_MD5SIG_ALIGNED
>> 2)
742 struct ip_reply_arg arg
;
743 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
745 memset(&rep
.th
, 0, sizeof(struct tcphdr
));
746 memset(&arg
, 0, sizeof(arg
));
748 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
749 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
751 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) | (TCPOPT_NOP
<< 16) |
752 (TCPOPT_TIMESTAMP
<< 8) |
754 rep
.opt
[1] = htonl(tsval
);
755 rep
.opt
[2] = htonl(tsecr
);
756 arg
.iov
[0].iov_len
+= TCPOLEN_TSTAMP_ALIGNED
;
759 /* Swap the send and the receive. */
760 rep
.th
.dest
= th
->source
;
761 rep
.th
.source
= th
->dest
;
762 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
763 rep
.th
.seq
= htonl(seq
);
764 rep
.th
.ack_seq
= htonl(ack
);
766 rep
.th
.window
= htons(win
);
768 #ifdef CONFIG_TCP_MD5SIG
770 int offset
= (tsecr
) ? 3 : 0;
772 rep
.opt
[offset
++] = htonl((TCPOPT_NOP
<< 24) |
774 (TCPOPT_MD5SIG
<< 8) |
776 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
777 rep
.th
.doff
= arg
.iov
[0].iov_len
/4;
779 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[offset
],
780 key
, ip_hdr(skb
)->saddr
,
781 ip_hdr(skb
)->daddr
, &rep
.th
);
784 arg
.flags
= reply_flags
;
785 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
786 ip_hdr(skb
)->saddr
, /* XXX */
787 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
788 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
790 arg
.bound_dev_if
= oif
;
792 ip_send_unicast_reply(net
, skb
, ip_hdr(skb
)->saddr
,
793 ip_hdr(skb
)->daddr
, &arg
, arg
.iov
[0].iov_len
);
795 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
798 static void tcp_v4_timewait_ack(struct sock
*sk
, struct sk_buff
*skb
)
800 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
801 struct tcp_timewait_sock
*tcptw
= tcp_twsk(sk
);
803 tcp_v4_send_ack(skb
, tcptw
->tw_snd_nxt
, tcptw
->tw_rcv_nxt
,
804 tcptw
->tw_rcv_wnd
>> tw
->tw_rcv_wscale
,
805 tcp_time_stamp
+ tcptw
->tw_ts_offset
,
808 tcp_twsk_md5_key(tcptw
),
809 tw
->tw_transparent
? IP_REPLY_ARG_NOSRCCHECK
: 0,
816 static void tcp_v4_reqsk_send_ack(struct sock
*sk
, struct sk_buff
*skb
,
817 struct request_sock
*req
)
819 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
820 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
822 tcp_v4_send_ack(skb
, (sk
->sk_state
== TCP_LISTEN
) ?
823 tcp_rsk(req
)->snt_isn
+ 1 : tcp_sk(sk
)->snd_nxt
,
824 tcp_rsk(req
)->rcv_nxt
, req
->rcv_wnd
,
828 tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&ip_hdr(skb
)->daddr
,
830 inet_rsk(req
)->no_srccheck
? IP_REPLY_ARG_NOSRCCHECK
: 0,
835 * Send a SYN-ACK after having received a SYN.
836 * This still operates on a request_sock only, not on a big
839 static int tcp_v4_send_synack(struct sock
*sk
, struct dst_entry
*dst
,
840 struct request_sock
*req
,
841 struct request_values
*rvp
,
845 const struct inet_request_sock
*ireq
= inet_rsk(req
);
848 struct sk_buff
* skb
;
850 /* First, grab a route. */
851 if (!dst
&& (dst
= inet_csk_route_req(sk
, &fl4
, req
)) == NULL
)
854 skb
= tcp_make_synack(sk
, dst
, req
, rvp
, NULL
);
857 __tcp_v4_send_check(skb
, ireq
->loc_addr
, ireq
->rmt_addr
);
859 skb_set_queue_mapping(skb
, queue_mapping
);
860 err
= ip_build_and_send_pkt(skb
, sk
, ireq
->loc_addr
,
863 err
= net_xmit_eval(err
);
864 if (!tcp_rsk(req
)->snt_synack
&& !err
)
865 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
871 static int tcp_v4_rtx_synack(struct sock
*sk
, struct request_sock
*req
,
872 struct request_values
*rvp
)
874 int res
= tcp_v4_send_synack(sk
, NULL
, req
, rvp
, 0, false);
877 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_RETRANSSEGS
);
882 * IPv4 request_sock destructor.
884 static void tcp_v4_reqsk_destructor(struct request_sock
*req
)
886 kfree(inet_rsk(req
)->opt
);
890 * Return true if a syncookie should be sent
892 bool tcp_syn_flood_action(struct sock
*sk
,
893 const struct sk_buff
*skb
,
896 const char *msg
= "Dropping request";
897 bool want_cookie
= false;
898 struct listen_sock
*lopt
;
902 #ifdef CONFIG_SYN_COOKIES
903 if (sysctl_tcp_syncookies
) {
904 msg
= "Sending cookies";
906 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPREQQFULLDOCOOKIES
);
909 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPREQQFULLDROP
);
911 lopt
= inet_csk(sk
)->icsk_accept_queue
.listen_opt
;
912 if (!lopt
->synflood_warned
) {
913 lopt
->synflood_warned
= 1;
914 pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
915 proto
, ntohs(tcp_hdr(skb
)->dest
), msg
);
919 EXPORT_SYMBOL(tcp_syn_flood_action
);
922 * Save and compile IPv4 options into the request_sock if needed.
924 static struct ip_options_rcu
*tcp_v4_save_options(struct sk_buff
*skb
)
926 const struct ip_options
*opt
= &(IPCB(skb
)->opt
);
927 struct ip_options_rcu
*dopt
= NULL
;
929 if (opt
&& opt
->optlen
) {
930 int opt_size
= sizeof(*dopt
) + opt
->optlen
;
932 dopt
= kmalloc(opt_size
, GFP_ATOMIC
);
934 if (ip_options_echo(&dopt
->opt
, skb
)) {
943 #ifdef CONFIG_TCP_MD5SIG
945 * RFC2385 MD5 checksumming requires a mapping of
946 * IP address->MD5 Key.
947 * We need to maintain these in the sk structure.
950 /* Find the Key structure for an address. */
951 struct tcp_md5sig_key
*tcp_md5_do_lookup(struct sock
*sk
,
952 const union tcp_md5_addr
*addr
,
955 struct tcp_sock
*tp
= tcp_sk(sk
);
956 struct tcp_md5sig_key
*key
;
957 struct hlist_node
*pos
;
958 unsigned int size
= sizeof(struct in_addr
);
959 struct tcp_md5sig_info
*md5sig
;
961 /* caller either holds rcu_read_lock() or socket lock */
962 md5sig
= rcu_dereference_check(tp
->md5sig_info
,
963 sock_owned_by_user(sk
) ||
964 lockdep_is_held(&sk
->sk_lock
.slock
));
967 #if IS_ENABLED(CONFIG_IPV6)
968 if (family
== AF_INET6
)
969 size
= sizeof(struct in6_addr
);
971 hlist_for_each_entry_rcu(key
, pos
, &md5sig
->head
, node
) {
972 if (key
->family
!= family
)
974 if (!memcmp(&key
->addr
, addr
, size
))
979 EXPORT_SYMBOL(tcp_md5_do_lookup
);
981 struct tcp_md5sig_key
*tcp_v4_md5_lookup(struct sock
*sk
,
982 struct sock
*addr_sk
)
984 union tcp_md5_addr
*addr
;
986 addr
= (union tcp_md5_addr
*)&inet_sk(addr_sk
)->inet_daddr
;
987 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
989 EXPORT_SYMBOL(tcp_v4_md5_lookup
);
991 static struct tcp_md5sig_key
*tcp_v4_reqsk_md5_lookup(struct sock
*sk
,
992 struct request_sock
*req
)
994 union tcp_md5_addr
*addr
;
996 addr
= (union tcp_md5_addr
*)&inet_rsk(req
)->rmt_addr
;
997 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
1000 /* This can be called on a newly created socket, from other files */
1001 int tcp_md5_do_add(struct sock
*sk
, const union tcp_md5_addr
*addr
,
1002 int family
, const u8
*newkey
, u8 newkeylen
, gfp_t gfp
)
1004 /* Add Key to the list */
1005 struct tcp_md5sig_key
*key
;
1006 struct tcp_sock
*tp
= tcp_sk(sk
);
1007 struct tcp_md5sig_info
*md5sig
;
1009 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&addr
, AF_INET
);
1011 /* Pre-existing entry - just update that one. */
1012 memcpy(key
->key
, newkey
, newkeylen
);
1013 key
->keylen
= newkeylen
;
1017 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
1018 sock_owned_by_user(sk
));
1020 md5sig
= kmalloc(sizeof(*md5sig
), gfp
);
1024 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
1025 INIT_HLIST_HEAD(&md5sig
->head
);
1026 rcu_assign_pointer(tp
->md5sig_info
, md5sig
);
1029 key
= sock_kmalloc(sk
, sizeof(*key
), gfp
);
1032 if (hlist_empty(&md5sig
->head
) && !tcp_alloc_md5sig_pool(sk
)) {
1033 sock_kfree_s(sk
, key
, sizeof(*key
));
1037 memcpy(key
->key
, newkey
, newkeylen
);
1038 key
->keylen
= newkeylen
;
1039 key
->family
= family
;
1040 memcpy(&key
->addr
, addr
,
1041 (family
== AF_INET6
) ? sizeof(struct in6_addr
) :
1042 sizeof(struct in_addr
));
1043 hlist_add_head_rcu(&key
->node
, &md5sig
->head
);
1046 EXPORT_SYMBOL(tcp_md5_do_add
);
1048 int tcp_md5_do_del(struct sock
*sk
, const union tcp_md5_addr
*addr
, int family
)
1050 struct tcp_sock
*tp
= tcp_sk(sk
);
1051 struct tcp_md5sig_key
*key
;
1052 struct tcp_md5sig_info
*md5sig
;
1054 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&addr
, AF_INET
);
1057 hlist_del_rcu(&key
->node
);
1058 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
1059 kfree_rcu(key
, rcu
);
1060 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
1061 sock_owned_by_user(sk
));
1062 if (hlist_empty(&md5sig
->head
))
1063 tcp_free_md5sig_pool();
1066 EXPORT_SYMBOL(tcp_md5_do_del
);
1068 static void tcp_clear_md5_list(struct sock
*sk
)
1070 struct tcp_sock
*tp
= tcp_sk(sk
);
1071 struct tcp_md5sig_key
*key
;
1072 struct hlist_node
*pos
, *n
;
1073 struct tcp_md5sig_info
*md5sig
;
1075 md5sig
= rcu_dereference_protected(tp
->md5sig_info
, 1);
1077 if (!hlist_empty(&md5sig
->head
))
1078 tcp_free_md5sig_pool();
1079 hlist_for_each_entry_safe(key
, pos
, n
, &md5sig
->head
, node
) {
1080 hlist_del_rcu(&key
->node
);
1081 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
1082 kfree_rcu(key
, rcu
);
1086 static int tcp_v4_parse_md5_keys(struct sock
*sk
, char __user
*optval
,
1089 struct tcp_md5sig cmd
;
1090 struct sockaddr_in
*sin
= (struct sockaddr_in
*)&cmd
.tcpm_addr
;
1092 if (optlen
< sizeof(cmd
))
1095 if (copy_from_user(&cmd
, optval
, sizeof(cmd
)))
1098 if (sin
->sin_family
!= AF_INET
)
1101 if (!cmd
.tcpm_key
|| !cmd
.tcpm_keylen
)
1102 return tcp_md5_do_del(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1105 if (cmd
.tcpm_keylen
> TCP_MD5SIG_MAXKEYLEN
)
1108 return tcp_md5_do_add(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1109 AF_INET
, cmd
.tcpm_key
, cmd
.tcpm_keylen
,
1113 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool
*hp
,
1114 __be32 daddr
, __be32 saddr
, int nbytes
)
1116 struct tcp4_pseudohdr
*bp
;
1117 struct scatterlist sg
;
1119 bp
= &hp
->md5_blk
.ip4
;
1122 * 1. the TCP pseudo-header (in the order: source IP address,
1123 * destination IP address, zero-padded protocol number, and
1129 bp
->protocol
= IPPROTO_TCP
;
1130 bp
->len
= cpu_to_be16(nbytes
);
1132 sg_init_one(&sg
, bp
, sizeof(*bp
));
1133 return crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(*bp
));
1136 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1137 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
)
1139 struct tcp_md5sig_pool
*hp
;
1140 struct hash_desc
*desc
;
1142 hp
= tcp_get_md5sig_pool();
1144 goto clear_hash_noput
;
1145 desc
= &hp
->md5_desc
;
1147 if (crypto_hash_init(desc
))
1149 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, th
->doff
<< 2))
1151 if (tcp_md5_hash_header(hp
, th
))
1153 if (tcp_md5_hash_key(hp
, key
))
1155 if (crypto_hash_final(desc
, md5_hash
))
1158 tcp_put_md5sig_pool();
1162 tcp_put_md5sig_pool();
1164 memset(md5_hash
, 0, 16);
1168 int tcp_v4_md5_hash_skb(char *md5_hash
, struct tcp_md5sig_key
*key
,
1169 const struct sock
*sk
, const struct request_sock
*req
,
1170 const struct sk_buff
*skb
)
1172 struct tcp_md5sig_pool
*hp
;
1173 struct hash_desc
*desc
;
1174 const struct tcphdr
*th
= tcp_hdr(skb
);
1175 __be32 saddr
, daddr
;
1178 saddr
= inet_sk(sk
)->inet_saddr
;
1179 daddr
= inet_sk(sk
)->inet_daddr
;
1181 saddr
= inet_rsk(req
)->loc_addr
;
1182 daddr
= inet_rsk(req
)->rmt_addr
;
1184 const struct iphdr
*iph
= ip_hdr(skb
);
1189 hp
= tcp_get_md5sig_pool();
1191 goto clear_hash_noput
;
1192 desc
= &hp
->md5_desc
;
1194 if (crypto_hash_init(desc
))
1197 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, skb
->len
))
1199 if (tcp_md5_hash_header(hp
, th
))
1201 if (tcp_md5_hash_skb_data(hp
, skb
, th
->doff
<< 2))
1203 if (tcp_md5_hash_key(hp
, key
))
1205 if (crypto_hash_final(desc
, md5_hash
))
1208 tcp_put_md5sig_pool();
1212 tcp_put_md5sig_pool();
1214 memset(md5_hash
, 0, 16);
1217 EXPORT_SYMBOL(tcp_v4_md5_hash_skb
);
1219 static bool tcp_v4_inbound_md5_hash(struct sock
*sk
, const struct sk_buff
*skb
)
1222 * This gets called for each TCP segment that arrives
1223 * so we want to be efficient.
1224 * We have 3 drop cases:
1225 * o No MD5 hash and one expected.
1226 * o MD5 hash and we're not expecting one.
1227 * o MD5 hash and its wrong.
1229 const __u8
*hash_location
= NULL
;
1230 struct tcp_md5sig_key
*hash_expected
;
1231 const struct iphdr
*iph
= ip_hdr(skb
);
1232 const struct tcphdr
*th
= tcp_hdr(skb
);
1234 unsigned char newhash
[16];
1236 hash_expected
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&iph
->saddr
,
1238 hash_location
= tcp_parse_md5sig_option(th
);
1240 /* We've parsed the options - do we have a hash? */
1241 if (!hash_expected
&& !hash_location
)
1244 if (hash_expected
&& !hash_location
) {
1245 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5NOTFOUND
);
1249 if (!hash_expected
&& hash_location
) {
1250 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5UNEXPECTED
);
1254 /* Okay, so this is hash_expected and hash_location -
1255 * so we need to calculate the checksum.
1257 genhash
= tcp_v4_md5_hash_skb(newhash
,
1261 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0) {
1262 net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1263 &iph
->saddr
, ntohs(th
->source
),
1264 &iph
->daddr
, ntohs(th
->dest
),
1265 genhash
? " tcp_v4_calc_md5_hash failed"
1274 struct request_sock_ops tcp_request_sock_ops __read_mostly
= {
1276 .obj_size
= sizeof(struct tcp_request_sock
),
1277 .rtx_syn_ack
= tcp_v4_rtx_synack
,
1278 .send_ack
= tcp_v4_reqsk_send_ack
,
1279 .destructor
= tcp_v4_reqsk_destructor
,
1280 .send_reset
= tcp_v4_send_reset
,
1281 .syn_ack_timeout
= tcp_syn_ack_timeout
,
1284 #ifdef CONFIG_TCP_MD5SIG
1285 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops
= {
1286 .md5_lookup
= tcp_v4_reqsk_md5_lookup
,
1287 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1291 static bool tcp_fastopen_check(struct sock
*sk
, struct sk_buff
*skb
,
1292 struct request_sock
*req
,
1293 struct tcp_fastopen_cookie
*foc
,
1294 struct tcp_fastopen_cookie
*valid_foc
)
1296 bool skip_cookie
= false;
1297 struct fastopen_queue
*fastopenq
;
1299 if (likely(!fastopen_cookie_present(foc
))) {
1300 /* See include/net/tcp.h for the meaning of these knobs */
1301 if ((sysctl_tcp_fastopen
& TFO_SERVER_ALWAYS
) ||
1302 ((sysctl_tcp_fastopen
& TFO_SERVER_COOKIE_NOT_REQD
) &&
1303 (TCP_SKB_CB(skb
)->end_seq
!= TCP_SKB_CB(skb
)->seq
+ 1)))
1304 skip_cookie
= true; /* no cookie to validate */
1308 fastopenq
= inet_csk(sk
)->icsk_accept_queue
.fastopenq
;
1309 /* A FO option is present; bump the counter. */
1310 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPFASTOPENPASSIVE
);
1312 /* Make sure the listener has enabled fastopen, and we don't
1313 * exceed the max # of pending TFO requests allowed before trying
1314 * to validating the cookie in order to avoid burning CPU cycles
1317 * XXX (TFO) - The implication of checking the max_qlen before
1318 * processing a cookie request is that clients can't differentiate
1319 * between qlen overflow causing Fast Open to be disabled
1320 * temporarily vs a server not supporting Fast Open at all.
1322 if ((sysctl_tcp_fastopen
& TFO_SERVER_ENABLE
) == 0 ||
1323 fastopenq
== NULL
|| fastopenq
->max_qlen
== 0)
1326 if (fastopenq
->qlen
>= fastopenq
->max_qlen
) {
1327 struct request_sock
*req1
;
1328 spin_lock(&fastopenq
->lock
);
1329 req1
= fastopenq
->rskq_rst_head
;
1330 if ((req1
== NULL
) || time_after(req1
->expires
, jiffies
)) {
1331 spin_unlock(&fastopenq
->lock
);
1332 NET_INC_STATS_BH(sock_net(sk
),
1333 LINUX_MIB_TCPFASTOPENLISTENOVERFLOW
);
1334 /* Avoid bumping LINUX_MIB_TCPFASTOPENPASSIVEFAIL*/
1338 fastopenq
->rskq_rst_head
= req1
->dl_next
;
1340 spin_unlock(&fastopenq
->lock
);
1344 tcp_rsk(req
)->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1347 if (foc
->len
== TCP_FASTOPEN_COOKIE_SIZE
) {
1348 if ((sysctl_tcp_fastopen
& TFO_SERVER_COOKIE_NOT_CHKED
) == 0) {
1349 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1350 if ((valid_foc
->len
!= TCP_FASTOPEN_COOKIE_SIZE
) ||
1351 memcmp(&foc
->val
[0], &valid_foc
->val
[0],
1352 TCP_FASTOPEN_COOKIE_SIZE
) != 0)
1354 valid_foc
->len
= -1;
1356 /* Acknowledge the data received from the peer. */
1357 tcp_rsk(req
)->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1359 } else if (foc
->len
== 0) { /* Client requesting a cookie */
1360 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1361 NET_INC_STATS_BH(sock_net(sk
),
1362 LINUX_MIB_TCPFASTOPENCOOKIEREQD
);
1364 /* Client sent a cookie with wrong size. Treat it
1365 * the same as invalid and return a valid one.
1367 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1372 static int tcp_v4_conn_req_fastopen(struct sock
*sk
,
1373 struct sk_buff
*skb
,
1374 struct sk_buff
*skb_synack
,
1375 struct request_sock
*req
,
1376 struct request_values
*rvp
)
1378 struct tcp_sock
*tp
= tcp_sk(sk
);
1379 struct request_sock_queue
*queue
= &inet_csk(sk
)->icsk_accept_queue
;
1380 const struct inet_request_sock
*ireq
= inet_rsk(req
);
1384 req
->num_retrans
= 0;
1385 req
->num_timeout
= 0;
1388 child
= inet_csk(sk
)->icsk_af_ops
->syn_recv_sock(sk
, skb
, req
, NULL
);
1389 if (child
== NULL
) {
1390 NET_INC_STATS_BH(sock_net(sk
),
1391 LINUX_MIB_TCPFASTOPENPASSIVEFAIL
);
1392 kfree_skb(skb_synack
);
1395 err
= ip_build_and_send_pkt(skb_synack
, sk
, ireq
->loc_addr
,
1396 ireq
->rmt_addr
, ireq
->opt
);
1397 err
= net_xmit_eval(err
);
1399 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
1400 /* XXX (TFO) - is it ok to ignore error and continue? */
1402 spin_lock(&queue
->fastopenq
->lock
);
1403 queue
->fastopenq
->qlen
++;
1404 spin_unlock(&queue
->fastopenq
->lock
);
1406 /* Initialize the child socket. Have to fix some values to take
1407 * into account the child is a Fast Open socket and is created
1408 * only out of the bits carried in the SYN packet.
1412 tp
->fastopen_rsk
= req
;
1413 /* Do a hold on the listner sk so that if the listener is being
1414 * closed, the child that has been accepted can live on and still
1415 * access listen_lock.
1418 tcp_rsk(req
)->listener
= sk
;
1420 /* RFC1323: The window in SYN & SYN/ACK segments is never
1421 * scaled. So correct it appropriately.
1423 tp
->snd_wnd
= ntohs(tcp_hdr(skb
)->window
);
1425 /* Activate the retrans timer so that SYNACK can be retransmitted.
1426 * The request socket is not added to the SYN table of the parent
1427 * because it's been added to the accept queue directly.
1429 inet_csk_reset_xmit_timer(child
, ICSK_TIME_RETRANS
,
1430 TCP_TIMEOUT_INIT
, TCP_RTO_MAX
);
1432 /* Add the child socket directly into the accept queue */
1433 inet_csk_reqsk_queue_add(sk
, req
, child
);
1435 /* Now finish processing the fastopen child socket. */
1436 inet_csk(child
)->icsk_af_ops
->rebuild_header(child
);
1437 tcp_init_congestion_control(child
);
1438 tcp_mtup_init(child
);
1439 tcp_init_buffer_space(child
);
1440 tcp_init_metrics(child
);
1442 /* Queue the data carried in the SYN packet. We need to first
1443 * bump skb's refcnt because the caller will attempt to free it.
1445 * XXX (TFO) - we honor a zero-payload TFO request for now.
1446 * (Any reason not to?)
1448 if (TCP_SKB_CB(skb
)->end_seq
== TCP_SKB_CB(skb
)->seq
+ 1) {
1449 /* Don't queue the skb if there is no payload in SYN.
1450 * XXX (TFO) - How about SYN+FIN?
1452 tp
->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1456 __skb_pull(skb
, tcp_hdr(skb
)->doff
* 4);
1457 skb_set_owner_r(skb
, child
);
1458 __skb_queue_tail(&child
->sk_receive_queue
, skb
);
1459 tp
->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1460 tp
->syn_data_acked
= 1;
1462 sk
->sk_data_ready(sk
, 0);
1463 bh_unlock_sock(child
);
1465 WARN_ON(req
->sk
== NULL
);
1469 int tcp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
)
1471 struct tcp_extend_values tmp_ext
;
1472 struct tcp_options_received tmp_opt
;
1473 const u8
*hash_location
;
1474 struct request_sock
*req
;
1475 struct inet_request_sock
*ireq
;
1476 struct tcp_sock
*tp
= tcp_sk(sk
);
1477 struct dst_entry
*dst
= NULL
;
1478 __be32 saddr
= ip_hdr(skb
)->saddr
;
1479 __be32 daddr
= ip_hdr(skb
)->daddr
;
1480 __u32 isn
= TCP_SKB_CB(skb
)->when
;
1481 bool want_cookie
= false;
1483 struct tcp_fastopen_cookie foc
= { .len
= -1 };
1484 struct tcp_fastopen_cookie valid_foc
= { .len
= -1 };
1485 struct sk_buff
*skb_synack
;
1488 /* Never answer to SYNs send to broadcast or multicast */
1489 if (skb_rtable(skb
)->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
))
1492 /* TW buckets are converted to open requests without
1493 * limitations, they conserve resources and peer is
1494 * evidently real one.
1496 if (inet_csk_reqsk_queue_is_full(sk
) && !isn
) {
1497 want_cookie
= tcp_syn_flood_action(sk
, skb
, "TCP");
1502 /* Accept backlog is full. If we have already queued enough
1503 * of warm entries in syn queue, drop request. It is better than
1504 * clogging syn queue with openreqs with exponentially increasing
1507 if (sk_acceptq_is_full(sk
) && inet_csk_reqsk_queue_young(sk
) > 1) {
1508 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1512 req
= inet_reqsk_alloc(&tcp_request_sock_ops
);
1516 #ifdef CONFIG_TCP_MD5SIG
1517 tcp_rsk(req
)->af_specific
= &tcp_request_sock_ipv4_ops
;
1520 tcp_clear_options(&tmp_opt
);
1521 tmp_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
1522 tmp_opt
.user_mss
= tp
->rx_opt
.user_mss
;
1523 tcp_parse_options(skb
, &tmp_opt
, &hash_location
, 0,
1524 want_cookie
? NULL
: &foc
);
1526 if (tmp_opt
.cookie_plus
> 0 &&
1527 tmp_opt
.saw_tstamp
&&
1528 !tp
->rx_opt
.cookie_out_never
&&
1529 (sysctl_tcp_cookie_size
> 0 ||
1530 (tp
->cookie_values
!= NULL
&&
1531 tp
->cookie_values
->cookie_desired
> 0))) {
1533 u32
*mess
= &tmp_ext
.cookie_bakery
[COOKIE_DIGEST_WORDS
];
1534 int l
= tmp_opt
.cookie_plus
- TCPOLEN_COOKIE_BASE
;
1536 if (tcp_cookie_generator(&tmp_ext
.cookie_bakery
[0]) != 0)
1537 goto drop_and_release
;
1539 /* Secret recipe starts with IP addresses */
1540 *mess
++ ^= (__force u32
)daddr
;
1541 *mess
++ ^= (__force u32
)saddr
;
1543 /* plus variable length Initiator Cookie */
1546 *c
++ ^= *hash_location
++;
1548 want_cookie
= false; /* not our kind of cookie */
1549 tmp_ext
.cookie_out_never
= 0; /* false */
1550 tmp_ext
.cookie_plus
= tmp_opt
.cookie_plus
;
1551 } else if (!tp
->rx_opt
.cookie_in_always
) {
1552 /* redundant indications, but ensure initialization. */
1553 tmp_ext
.cookie_out_never
= 1; /* true */
1554 tmp_ext
.cookie_plus
= 0;
1556 goto drop_and_release
;
1558 tmp_ext
.cookie_in_always
= tp
->rx_opt
.cookie_in_always
;
1560 if (want_cookie
&& !tmp_opt
.saw_tstamp
)
1561 tcp_clear_options(&tmp_opt
);
1563 tmp_opt
.tstamp_ok
= tmp_opt
.saw_tstamp
;
1564 tcp_openreq_init(req
, &tmp_opt
, skb
);
1566 ireq
= inet_rsk(req
);
1567 ireq
->loc_addr
= daddr
;
1568 ireq
->rmt_addr
= saddr
;
1569 ireq
->no_srccheck
= inet_sk(sk
)->transparent
;
1570 ireq
->opt
= tcp_v4_save_options(skb
);
1572 if (security_inet_conn_request(sk
, skb
, req
))
1575 if (!want_cookie
|| tmp_opt
.tstamp_ok
)
1576 TCP_ECN_create_request(req
, skb
, sock_net(sk
));
1579 isn
= cookie_v4_init_sequence(sk
, skb
, &req
->mss
);
1580 req
->cookie_ts
= tmp_opt
.tstamp_ok
;
1582 /* VJ's idea. We save last timestamp seen
1583 * from the destination in peer table, when entering
1584 * state TIME-WAIT, and check against it before
1585 * accepting new connection request.
1587 * If "isn" is not zero, this request hit alive
1588 * timewait bucket, so that all the necessary checks
1589 * are made in the function processing timewait state.
1591 if (tmp_opt
.saw_tstamp
&&
1592 tcp_death_row
.sysctl_tw_recycle
&&
1593 (dst
= inet_csk_route_req(sk
, &fl4
, req
)) != NULL
&&
1594 fl4
.daddr
== saddr
) {
1595 if (!tcp_peer_is_proven(req
, dst
, true)) {
1596 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_PAWSPASSIVEREJECTED
);
1597 goto drop_and_release
;
1600 /* Kill the following clause, if you dislike this way. */
1601 else if (!sysctl_tcp_syncookies
&&
1602 (sysctl_max_syn_backlog
- inet_csk_reqsk_queue_len(sk
) <
1603 (sysctl_max_syn_backlog
>> 2)) &&
1604 !tcp_peer_is_proven(req
, dst
, false)) {
1605 /* Without syncookies last quarter of
1606 * backlog is filled with destinations,
1607 * proven to be alive.
1608 * It means that we continue to communicate
1609 * to destinations, already remembered
1610 * to the moment of synflood.
1612 LIMIT_NETDEBUG(KERN_DEBUG
pr_fmt("drop open request from %pI4/%u\n"),
1613 &saddr
, ntohs(tcp_hdr(skb
)->source
));
1614 goto drop_and_release
;
1617 isn
= tcp_v4_init_sequence(skb
);
1619 tcp_rsk(req
)->snt_isn
= isn
;
1622 dst
= inet_csk_route_req(sk
, &fl4
, req
);
1626 do_fastopen
= tcp_fastopen_check(sk
, skb
, req
, &foc
, &valid_foc
);
1628 /* We don't call tcp_v4_send_synack() directly because we need
1629 * to make sure a child socket can be created successfully before
1630 * sending back synack!
1632 * XXX (TFO) - Ideally one would simply call tcp_v4_send_synack()
1633 * (or better yet, call tcp_send_synack() in the child context
1634 * directly, but will have to fix bunch of other code first)
1635 * after syn_recv_sock() except one will need to first fix the
1636 * latter to remove its dependency on the current implementation
1637 * of tcp_v4_send_synack()->tcp_select_initial_window().
1639 skb_synack
= tcp_make_synack(sk
, dst
, req
,
1640 (struct request_values
*)&tmp_ext
,
1641 fastopen_cookie_present(&valid_foc
) ? &valid_foc
: NULL
);
1644 __tcp_v4_send_check(skb_synack
, ireq
->loc_addr
, ireq
->rmt_addr
);
1645 skb_set_queue_mapping(skb_synack
, skb_get_queue_mapping(skb
));
1649 if (likely(!do_fastopen
)) {
1651 err
= ip_build_and_send_pkt(skb_synack
, sk
, ireq
->loc_addr
,
1652 ireq
->rmt_addr
, ireq
->opt
);
1653 err
= net_xmit_eval(err
);
1654 if (err
|| want_cookie
)
1657 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
1658 tcp_rsk(req
)->listener
= NULL
;
1659 /* Add the request_sock to the SYN table */
1660 inet_csk_reqsk_queue_hash_add(sk
, req
, TCP_TIMEOUT_INIT
);
1661 if (fastopen_cookie_present(&foc
) && foc
.len
!= 0)
1662 NET_INC_STATS_BH(sock_net(sk
),
1663 LINUX_MIB_TCPFASTOPENPASSIVEFAIL
);
1664 } else if (tcp_v4_conn_req_fastopen(sk
, skb
, skb_synack
, req
,
1665 (struct request_values
*)&tmp_ext
))
1675 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1678 EXPORT_SYMBOL(tcp_v4_conn_request
);
1682 * The three way handshake has completed - we got a valid synack -
1683 * now create the new socket.
1685 struct sock
*tcp_v4_syn_recv_sock(struct sock
*sk
, struct sk_buff
*skb
,
1686 struct request_sock
*req
,
1687 struct dst_entry
*dst
)
1689 struct inet_request_sock
*ireq
;
1690 struct inet_sock
*newinet
;
1691 struct tcp_sock
*newtp
;
1693 #ifdef CONFIG_TCP_MD5SIG
1694 struct tcp_md5sig_key
*key
;
1696 struct ip_options_rcu
*inet_opt
;
1698 if (sk_acceptq_is_full(sk
))
1701 newsk
= tcp_create_openreq_child(sk
, req
, skb
);
1705 newsk
->sk_gso_type
= SKB_GSO_TCPV4
;
1706 inet_sk_rx_dst_set(newsk
, skb
);
1708 newtp
= tcp_sk(newsk
);
1709 newinet
= inet_sk(newsk
);
1710 ireq
= inet_rsk(req
);
1711 newinet
->inet_daddr
= ireq
->rmt_addr
;
1712 newinet
->inet_rcv_saddr
= ireq
->loc_addr
;
1713 newinet
->inet_saddr
= ireq
->loc_addr
;
1714 inet_opt
= ireq
->opt
;
1715 rcu_assign_pointer(newinet
->inet_opt
, inet_opt
);
1717 newinet
->mc_index
= inet_iif(skb
);
1718 newinet
->mc_ttl
= ip_hdr(skb
)->ttl
;
1719 newinet
->rcv_tos
= ip_hdr(skb
)->tos
;
1720 inet_csk(newsk
)->icsk_ext_hdr_len
= 0;
1722 inet_csk(newsk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
1723 newinet
->inet_id
= newtp
->write_seq
^ jiffies
;
1726 dst
= inet_csk_route_child_sock(sk
, newsk
, req
);
1730 /* syncookie case : see end of cookie_v4_check() */
1732 sk_setup_caps(newsk
, dst
);
1734 tcp_mtup_init(newsk
);
1735 tcp_sync_mss(newsk
, dst_mtu(dst
));
1736 newtp
->advmss
= dst_metric_advmss(dst
);
1737 if (tcp_sk(sk
)->rx_opt
.user_mss
&&
1738 tcp_sk(sk
)->rx_opt
.user_mss
< newtp
->advmss
)
1739 newtp
->advmss
= tcp_sk(sk
)->rx_opt
.user_mss
;
1741 tcp_initialize_rcv_mss(newsk
);
1742 tcp_synack_rtt_meas(newsk
, req
);
1743 newtp
->total_retrans
= req
->num_retrans
;
1745 #ifdef CONFIG_TCP_MD5SIG
1746 /* Copy over the MD5 key from the original socket */
1747 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1751 * We're using one, so create a matching key
1752 * on the newsk structure. If we fail to get
1753 * memory, then we end up not copying the key
1756 tcp_md5_do_add(newsk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1757 AF_INET
, key
->key
, key
->keylen
, GFP_ATOMIC
);
1758 sk_nocaps_add(newsk
, NETIF_F_GSO_MASK
);
1762 if (__inet_inherit_port(sk
, newsk
) < 0)
1764 __inet_hash_nolisten(newsk
, NULL
);
1769 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1773 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1776 inet_csk_prepare_forced_close(newsk
);
1780 EXPORT_SYMBOL(tcp_v4_syn_recv_sock
);
1782 static struct sock
*tcp_v4_hnd_req(struct sock
*sk
, struct sk_buff
*skb
)
1784 struct tcphdr
*th
= tcp_hdr(skb
);
1785 const struct iphdr
*iph
= ip_hdr(skb
);
1787 struct request_sock
**prev
;
1788 /* Find possible connection requests. */
1789 struct request_sock
*req
= inet_csk_search_req(sk
, &prev
, th
->source
,
1790 iph
->saddr
, iph
->daddr
);
1792 return tcp_check_req(sk
, skb
, req
, prev
, false);
1794 nsk
= inet_lookup_established(sock_net(sk
), &tcp_hashinfo
, iph
->saddr
,
1795 th
->source
, iph
->daddr
, th
->dest
, inet_iif(skb
));
1798 if (nsk
->sk_state
!= TCP_TIME_WAIT
) {
1802 inet_twsk_put(inet_twsk(nsk
));
1806 #ifdef CONFIG_SYN_COOKIES
1808 sk
= cookie_v4_check(sk
, skb
, &(IPCB(skb
)->opt
));
1813 static __sum16
tcp_v4_checksum_init(struct sk_buff
*skb
)
1815 const struct iphdr
*iph
= ip_hdr(skb
);
1817 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
1818 if (!tcp_v4_check(skb
->len
, iph
->saddr
,
1819 iph
->daddr
, skb
->csum
)) {
1820 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1825 skb
->csum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
1826 skb
->len
, IPPROTO_TCP
, 0);
1828 if (skb
->len
<= 76) {
1829 return __skb_checksum_complete(skb
);
1835 /* The socket must have it's spinlock held when we get
1838 * We have a potential double-lock case here, so even when
1839 * doing backlog processing we use the BH locking scheme.
1840 * This is because we cannot sleep with the original spinlock
1843 int tcp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
)
1846 #ifdef CONFIG_TCP_MD5SIG
1848 * We really want to reject the packet as early as possible
1850 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1851 * o There is an MD5 option and we're not expecting one
1853 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1857 if (sk
->sk_state
== TCP_ESTABLISHED
) { /* Fast path */
1858 struct dst_entry
*dst
= sk
->sk_rx_dst
;
1860 sock_rps_save_rxhash(sk
, skb
);
1862 if (inet_sk(sk
)->rx_dst_ifindex
!= skb
->skb_iif
||
1863 dst
->ops
->check(dst
, 0) == NULL
) {
1865 sk
->sk_rx_dst
= NULL
;
1868 if (tcp_rcv_established(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1875 if (skb
->len
< tcp_hdrlen(skb
) || tcp_checksum_complete(skb
))
1878 if (sk
->sk_state
== TCP_LISTEN
) {
1879 struct sock
*nsk
= tcp_v4_hnd_req(sk
, skb
);
1884 sock_rps_save_rxhash(nsk
, skb
);
1885 if (tcp_child_process(sk
, nsk
, skb
)) {
1892 sock_rps_save_rxhash(sk
, skb
);
1894 if (tcp_rcv_state_process(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1901 tcp_v4_send_reset(rsk
, skb
);
1904 /* Be careful here. If this function gets more complicated and
1905 * gcc suffers from register pressure on the x86, sk (in %ebx)
1906 * might be destroyed here. This current version compiles correctly,
1907 * but you have been warned.
1912 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_INERRS
);
1915 EXPORT_SYMBOL(tcp_v4_do_rcv
);
1917 void tcp_v4_early_demux(struct sk_buff
*skb
)
1919 const struct iphdr
*iph
;
1920 const struct tcphdr
*th
;
1923 if (skb
->pkt_type
!= PACKET_HOST
)
1926 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + sizeof(struct tcphdr
)))
1932 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1935 sk
= __inet_lookup_established(dev_net(skb
->dev
), &tcp_hashinfo
,
1936 iph
->saddr
, th
->source
,
1937 iph
->daddr
, ntohs(th
->dest
),
1941 skb
->destructor
= sock_edemux
;
1942 if (sk
->sk_state
!= TCP_TIME_WAIT
) {
1943 struct dst_entry
*dst
= sk
->sk_rx_dst
;
1946 dst
= dst_check(dst
, 0);
1948 inet_sk(sk
)->rx_dst_ifindex
== skb
->skb_iif
)
1949 skb_dst_set_noref(skb
, dst
);
1958 int tcp_v4_rcv(struct sk_buff
*skb
)
1960 const struct iphdr
*iph
;
1961 const struct tcphdr
*th
;
1964 struct net
*net
= dev_net(skb
->dev
);
1966 if (skb
->pkt_type
!= PACKET_HOST
)
1969 /* Count it even if it's bad */
1970 TCP_INC_STATS_BH(net
, TCP_MIB_INSEGS
);
1972 if (!pskb_may_pull(skb
, sizeof(struct tcphdr
)))
1977 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1979 if (!pskb_may_pull(skb
, th
->doff
* 4))
1982 /* An explanation is required here, I think.
1983 * Packet length and doff are validated by header prediction,
1984 * provided case of th->doff==0 is eliminated.
1985 * So, we defer the checks. */
1986 if (!skb_csum_unnecessary(skb
) && tcp_v4_checksum_init(skb
))
1991 TCP_SKB_CB(skb
)->seq
= ntohl(th
->seq
);
1992 TCP_SKB_CB(skb
)->end_seq
= (TCP_SKB_CB(skb
)->seq
+ th
->syn
+ th
->fin
+
1993 skb
->len
- th
->doff
* 4);
1994 TCP_SKB_CB(skb
)->ack_seq
= ntohl(th
->ack_seq
);
1995 TCP_SKB_CB(skb
)->when
= 0;
1996 TCP_SKB_CB(skb
)->ip_dsfield
= ipv4_get_dsfield(iph
);
1997 TCP_SKB_CB(skb
)->sacked
= 0;
1999 sk
= __inet_lookup_skb(&tcp_hashinfo
, skb
, th
->source
, th
->dest
);
2004 if (sk
->sk_state
== TCP_TIME_WAIT
)
2007 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
2008 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
2009 goto discard_and_relse
;
2012 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
2013 goto discard_and_relse
;
2016 if (sk_filter(sk
, skb
))
2017 goto discard_and_relse
;
2021 bh_lock_sock_nested(sk
);
2023 if (!sock_owned_by_user(sk
)) {
2024 #ifdef CONFIG_NET_DMA
2025 struct tcp_sock
*tp
= tcp_sk(sk
);
2026 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
2027 tp
->ucopy
.dma_chan
= net_dma_find_channel();
2028 if (tp
->ucopy
.dma_chan
)
2029 ret
= tcp_v4_do_rcv(sk
, skb
);
2033 if (!tcp_prequeue(sk
, skb
))
2034 ret
= tcp_v4_do_rcv(sk
, skb
);
2036 } else if (unlikely(sk_add_backlog(sk
, skb
,
2037 sk
->sk_rcvbuf
+ sk
->sk_sndbuf
))) {
2039 NET_INC_STATS_BH(net
, LINUX_MIB_TCPBACKLOGDROP
);
2040 goto discard_and_relse
;
2049 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
2052 if (skb
->len
< (th
->doff
<< 2) || tcp_checksum_complete(skb
)) {
2054 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
2056 tcp_v4_send_reset(NULL
, skb
);
2060 /* Discard frame. */
2069 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
)) {
2070 inet_twsk_put(inet_twsk(sk
));
2074 if (skb
->len
< (th
->doff
<< 2) || tcp_checksum_complete(skb
)) {
2075 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
2076 inet_twsk_put(inet_twsk(sk
));
2079 switch (tcp_timewait_state_process(inet_twsk(sk
), skb
, th
)) {
2081 struct sock
*sk2
= inet_lookup_listener(dev_net(skb
->dev
),
2083 iph
->saddr
, th
->source
,
2084 iph
->daddr
, th
->dest
,
2087 inet_twsk_deschedule(inet_twsk(sk
), &tcp_death_row
);
2088 inet_twsk_put(inet_twsk(sk
));
2092 /* Fall through to ACK */
2095 tcp_v4_timewait_ack(sk
, skb
);
2099 case TCP_TW_SUCCESS
:;
2104 static struct timewait_sock_ops tcp_timewait_sock_ops
= {
2105 .twsk_obj_size
= sizeof(struct tcp_timewait_sock
),
2106 .twsk_unique
= tcp_twsk_unique
,
2107 .twsk_destructor
= tcp_twsk_destructor
,
2110 void inet_sk_rx_dst_set(struct sock
*sk
, const struct sk_buff
*skb
)
2112 struct dst_entry
*dst
= skb_dst(skb
);
2115 sk
->sk_rx_dst
= dst
;
2116 inet_sk(sk
)->rx_dst_ifindex
= skb
->skb_iif
;
2118 EXPORT_SYMBOL(inet_sk_rx_dst_set
);
2120 const struct inet_connection_sock_af_ops ipv4_specific
= {
2121 .queue_xmit
= ip_queue_xmit
,
2122 .send_check
= tcp_v4_send_check
,
2123 .rebuild_header
= inet_sk_rebuild_header
,
2124 .sk_rx_dst_set
= inet_sk_rx_dst_set
,
2125 .conn_request
= tcp_v4_conn_request
,
2126 .syn_recv_sock
= tcp_v4_syn_recv_sock
,
2127 .net_header_len
= sizeof(struct iphdr
),
2128 .setsockopt
= ip_setsockopt
,
2129 .getsockopt
= ip_getsockopt
,
2130 .addr2sockaddr
= inet_csk_addr2sockaddr
,
2131 .sockaddr_len
= sizeof(struct sockaddr_in
),
2132 .bind_conflict
= inet_csk_bind_conflict
,
2133 #ifdef CONFIG_COMPAT
2134 .compat_setsockopt
= compat_ip_setsockopt
,
2135 .compat_getsockopt
= compat_ip_getsockopt
,
2138 EXPORT_SYMBOL(ipv4_specific
);
2140 #ifdef CONFIG_TCP_MD5SIG
2141 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific
= {
2142 .md5_lookup
= tcp_v4_md5_lookup
,
2143 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
2144 .md5_parse
= tcp_v4_parse_md5_keys
,
2148 /* NOTE: A lot of things set to zero explicitly by call to
2149 * sk_alloc() so need not be done here.
2151 static int tcp_v4_init_sock(struct sock
*sk
)
2153 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2157 icsk
->icsk_af_ops
= &ipv4_specific
;
2159 #ifdef CONFIG_TCP_MD5SIG
2160 tcp_sk(sk
)->af_specific
= &tcp_sock_ipv4_specific
;
2166 void tcp_v4_destroy_sock(struct sock
*sk
)
2168 struct tcp_sock
*tp
= tcp_sk(sk
);
2170 tcp_clear_xmit_timers(sk
);
2172 tcp_cleanup_congestion_control(sk
);
2174 /* Cleanup up the write buffer. */
2175 tcp_write_queue_purge(sk
);
2177 /* Cleans up our, hopefully empty, out_of_order_queue. */
2178 __skb_queue_purge(&tp
->out_of_order_queue
);
2180 #ifdef CONFIG_TCP_MD5SIG
2181 /* Clean up the MD5 key list, if any */
2182 if (tp
->md5sig_info
) {
2183 tcp_clear_md5_list(sk
);
2184 kfree_rcu(tp
->md5sig_info
, rcu
);
2185 tp
->md5sig_info
= NULL
;
2189 #ifdef CONFIG_NET_DMA
2190 /* Cleans up our sk_async_wait_queue */
2191 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2194 /* Clean prequeue, it must be empty really */
2195 __skb_queue_purge(&tp
->ucopy
.prequeue
);
2197 /* Clean up a referenced TCP bind bucket. */
2198 if (inet_csk(sk
)->icsk_bind_hash
)
2201 /* TCP Cookie Transactions */
2202 if (tp
->cookie_values
!= NULL
) {
2203 kref_put(&tp
->cookie_values
->kref
,
2204 tcp_cookie_values_release
);
2205 tp
->cookie_values
= NULL
;
2207 BUG_ON(tp
->fastopen_rsk
!= NULL
);
2209 /* If socket is aborted during connect operation */
2210 tcp_free_fastopen_req(tp
);
2212 sk_sockets_allocated_dec(sk
);
2213 sock_release_memcg(sk
);
2215 EXPORT_SYMBOL(tcp_v4_destroy_sock
);
2217 #ifdef CONFIG_PROC_FS
2218 /* Proc filesystem TCP sock list dumping. */
2220 static inline struct inet_timewait_sock
*tw_head(struct hlist_nulls_head
*head
)
2222 return hlist_nulls_empty(head
) ? NULL
:
2223 list_entry(head
->first
, struct inet_timewait_sock
, tw_node
);
2226 static inline struct inet_timewait_sock
*tw_next(struct inet_timewait_sock
*tw
)
2228 return !is_a_nulls(tw
->tw_node
.next
) ?
2229 hlist_nulls_entry(tw
->tw_node
.next
, typeof(*tw
), tw_node
) : NULL
;
2233 * Get next listener socket follow cur. If cur is NULL, get first socket
2234 * starting from bucket given in st->bucket; when st->bucket is zero the
2235 * very first socket in the hash table is returned.
2237 static void *listening_get_next(struct seq_file
*seq
, void *cur
)
2239 struct inet_connection_sock
*icsk
;
2240 struct hlist_nulls_node
*node
;
2241 struct sock
*sk
= cur
;
2242 struct inet_listen_hashbucket
*ilb
;
2243 struct tcp_iter_state
*st
= seq
->private;
2244 struct net
*net
= seq_file_net(seq
);
2247 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2248 spin_lock_bh(&ilb
->lock
);
2249 sk
= sk_nulls_head(&ilb
->head
);
2253 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2257 if (st
->state
== TCP_SEQ_STATE_OPENREQ
) {
2258 struct request_sock
*req
= cur
;
2260 icsk
= inet_csk(st
->syn_wait_sk
);
2264 if (req
->rsk_ops
->family
== st
->family
) {
2270 if (++st
->sbucket
>= icsk
->icsk_accept_queue
.listen_opt
->nr_table_entries
)
2273 req
= icsk
->icsk_accept_queue
.listen_opt
->syn_table
[st
->sbucket
];
2275 sk
= sk_nulls_next(st
->syn_wait_sk
);
2276 st
->state
= TCP_SEQ_STATE_LISTENING
;
2277 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2279 icsk
= inet_csk(sk
);
2280 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2281 if (reqsk_queue_len(&icsk
->icsk_accept_queue
))
2283 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2284 sk
= sk_nulls_next(sk
);
2287 sk_nulls_for_each_from(sk
, node
) {
2288 if (!net_eq(sock_net(sk
), net
))
2290 if (sk
->sk_family
== st
->family
) {
2294 icsk
= inet_csk(sk
);
2295 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2296 if (reqsk_queue_len(&icsk
->icsk_accept_queue
)) {
2298 st
->uid
= sock_i_uid(sk
);
2299 st
->syn_wait_sk
= sk
;
2300 st
->state
= TCP_SEQ_STATE_OPENREQ
;
2304 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2306 spin_unlock_bh(&ilb
->lock
);
2308 if (++st
->bucket
< INET_LHTABLE_SIZE
) {
2309 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2310 spin_lock_bh(&ilb
->lock
);
2311 sk
= sk_nulls_head(&ilb
->head
);
2319 static void *listening_get_idx(struct seq_file
*seq
, loff_t
*pos
)
2321 struct tcp_iter_state
*st
= seq
->private;
2326 rc
= listening_get_next(seq
, NULL
);
2328 while (rc
&& *pos
) {
2329 rc
= listening_get_next(seq
, rc
);
2335 static inline bool empty_bucket(struct tcp_iter_state
*st
)
2337 return hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].chain
) &&
2338 hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2342 * Get first established socket starting from bucket given in st->bucket.
2343 * If st->bucket is zero, the very first socket in the hash is returned.
2345 static void *established_get_first(struct seq_file
*seq
)
2347 struct tcp_iter_state
*st
= seq
->private;
2348 struct net
*net
= seq_file_net(seq
);
2352 for (; st
->bucket
<= tcp_hashinfo
.ehash_mask
; ++st
->bucket
) {
2354 struct hlist_nulls_node
*node
;
2355 struct inet_timewait_sock
*tw
;
2356 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
);
2358 /* Lockless fast path for the common case of empty buckets */
2359 if (empty_bucket(st
))
2363 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[st
->bucket
].chain
) {
2364 if (sk
->sk_family
!= st
->family
||
2365 !net_eq(sock_net(sk
), net
)) {
2371 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2372 inet_twsk_for_each(tw
, node
,
2373 &tcp_hashinfo
.ehash
[st
->bucket
].twchain
) {
2374 if (tw
->tw_family
!= st
->family
||
2375 !net_eq(twsk_net(tw
), net
)) {
2381 spin_unlock_bh(lock
);
2382 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2388 static void *established_get_next(struct seq_file
*seq
, void *cur
)
2390 struct sock
*sk
= cur
;
2391 struct inet_timewait_sock
*tw
;
2392 struct hlist_nulls_node
*node
;
2393 struct tcp_iter_state
*st
= seq
->private;
2394 struct net
*net
= seq_file_net(seq
);
2399 if (st
->state
== TCP_SEQ_STATE_TIME_WAIT
) {
2403 while (tw
&& (tw
->tw_family
!= st
->family
|| !net_eq(twsk_net(tw
), net
))) {
2410 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2411 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2413 /* Look for next non empty bucket */
2415 while (++st
->bucket
<= tcp_hashinfo
.ehash_mask
&&
2418 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2421 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2422 sk
= sk_nulls_head(&tcp_hashinfo
.ehash
[st
->bucket
].chain
);
2424 sk
= sk_nulls_next(sk
);
2426 sk_nulls_for_each_from(sk
, node
) {
2427 if (sk
->sk_family
== st
->family
&& net_eq(sock_net(sk
), net
))
2431 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2432 tw
= tw_head(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2440 static void *established_get_idx(struct seq_file
*seq
, loff_t pos
)
2442 struct tcp_iter_state
*st
= seq
->private;
2446 rc
= established_get_first(seq
);
2449 rc
= established_get_next(seq
, rc
);
2455 static void *tcp_get_idx(struct seq_file
*seq
, loff_t pos
)
2458 struct tcp_iter_state
*st
= seq
->private;
2460 st
->state
= TCP_SEQ_STATE_LISTENING
;
2461 rc
= listening_get_idx(seq
, &pos
);
2464 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2465 rc
= established_get_idx(seq
, pos
);
2471 static void *tcp_seek_last_pos(struct seq_file
*seq
)
2473 struct tcp_iter_state
*st
= seq
->private;
2474 int offset
= st
->offset
;
2475 int orig_num
= st
->num
;
2478 switch (st
->state
) {
2479 case TCP_SEQ_STATE_OPENREQ
:
2480 case TCP_SEQ_STATE_LISTENING
:
2481 if (st
->bucket
>= INET_LHTABLE_SIZE
)
2483 st
->state
= TCP_SEQ_STATE_LISTENING
;
2484 rc
= listening_get_next(seq
, NULL
);
2485 while (offset
-- && rc
)
2486 rc
= listening_get_next(seq
, rc
);
2491 case TCP_SEQ_STATE_ESTABLISHED
:
2492 case TCP_SEQ_STATE_TIME_WAIT
:
2493 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2494 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2496 rc
= established_get_first(seq
);
2497 while (offset
-- && rc
)
2498 rc
= established_get_next(seq
, rc
);
2506 static void *tcp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2508 struct tcp_iter_state
*st
= seq
->private;
2511 if (*pos
&& *pos
== st
->last_pos
) {
2512 rc
= tcp_seek_last_pos(seq
);
2517 st
->state
= TCP_SEQ_STATE_LISTENING
;
2521 rc
= *pos
? tcp_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2524 st
->last_pos
= *pos
;
2528 static void *tcp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2530 struct tcp_iter_state
*st
= seq
->private;
2533 if (v
== SEQ_START_TOKEN
) {
2534 rc
= tcp_get_idx(seq
, 0);
2538 switch (st
->state
) {
2539 case TCP_SEQ_STATE_OPENREQ
:
2540 case TCP_SEQ_STATE_LISTENING
:
2541 rc
= listening_get_next(seq
, v
);
2543 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2546 rc
= established_get_first(seq
);
2549 case TCP_SEQ_STATE_ESTABLISHED
:
2550 case TCP_SEQ_STATE_TIME_WAIT
:
2551 rc
= established_get_next(seq
, v
);
2556 st
->last_pos
= *pos
;
2560 static void tcp_seq_stop(struct seq_file
*seq
, void *v
)
2562 struct tcp_iter_state
*st
= seq
->private;
2564 switch (st
->state
) {
2565 case TCP_SEQ_STATE_OPENREQ
:
2567 struct inet_connection_sock
*icsk
= inet_csk(st
->syn_wait_sk
);
2568 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2570 case TCP_SEQ_STATE_LISTENING
:
2571 if (v
!= SEQ_START_TOKEN
)
2572 spin_unlock_bh(&tcp_hashinfo
.listening_hash
[st
->bucket
].lock
);
2574 case TCP_SEQ_STATE_TIME_WAIT
:
2575 case TCP_SEQ_STATE_ESTABLISHED
:
2577 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2582 int tcp_seq_open(struct inode
*inode
, struct file
*file
)
2584 struct tcp_seq_afinfo
*afinfo
= PDE(inode
)->data
;
2585 struct tcp_iter_state
*s
;
2588 err
= seq_open_net(inode
, file
, &afinfo
->seq_ops
,
2589 sizeof(struct tcp_iter_state
));
2593 s
= ((struct seq_file
*)file
->private_data
)->private;
2594 s
->family
= afinfo
->family
;
2598 EXPORT_SYMBOL(tcp_seq_open
);
2600 int tcp_proc_register(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2603 struct proc_dir_entry
*p
;
2605 afinfo
->seq_ops
.start
= tcp_seq_start
;
2606 afinfo
->seq_ops
.next
= tcp_seq_next
;
2607 afinfo
->seq_ops
.stop
= tcp_seq_stop
;
2609 p
= proc_create_data(afinfo
->name
, S_IRUGO
, net
->proc_net
,
2610 afinfo
->seq_fops
, afinfo
);
2615 EXPORT_SYMBOL(tcp_proc_register
);
2617 void tcp_proc_unregister(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2619 proc_net_remove(net
, afinfo
->name
);
2621 EXPORT_SYMBOL(tcp_proc_unregister
);
2623 static void get_openreq4(const struct sock
*sk
, const struct request_sock
*req
,
2624 struct seq_file
*f
, int i
, kuid_t uid
, int *len
)
2626 const struct inet_request_sock
*ireq
= inet_rsk(req
);
2627 long delta
= req
->expires
- jiffies
;
2629 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2630 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
2633 ntohs(inet_sk(sk
)->inet_sport
),
2635 ntohs(ireq
->rmt_port
),
2637 0, 0, /* could print option size, but that is af dependent. */
2638 1, /* timers active (only the expire timer) */
2639 jiffies_delta_to_clock_t(delta
),
2641 from_kuid_munged(seq_user_ns(f
), uid
),
2642 0, /* non standard timer */
2643 0, /* open_requests have no inode */
2644 atomic_read(&sk
->sk_refcnt
),
2649 static void get_tcp4_sock(struct sock
*sk
, struct seq_file
*f
, int i
, int *len
)
2652 unsigned long timer_expires
;
2653 const struct tcp_sock
*tp
= tcp_sk(sk
);
2654 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2655 const struct inet_sock
*inet
= inet_sk(sk
);
2656 struct fastopen_queue
*fastopenq
= icsk
->icsk_accept_queue
.fastopenq
;
2657 __be32 dest
= inet
->inet_daddr
;
2658 __be32 src
= inet
->inet_rcv_saddr
;
2659 __u16 destp
= ntohs(inet
->inet_dport
);
2660 __u16 srcp
= ntohs(inet
->inet_sport
);
2663 if (icsk
->icsk_pending
== ICSK_TIME_RETRANS
) {
2665 timer_expires
= icsk
->icsk_timeout
;
2666 } else if (icsk
->icsk_pending
== ICSK_TIME_PROBE0
) {
2668 timer_expires
= icsk
->icsk_timeout
;
2669 } else if (timer_pending(&sk
->sk_timer
)) {
2671 timer_expires
= sk
->sk_timer
.expires
;
2674 timer_expires
= jiffies
;
2677 if (sk
->sk_state
== TCP_LISTEN
)
2678 rx_queue
= sk
->sk_ack_backlog
;
2681 * because we dont lock socket, we might find a transient negative value
2683 rx_queue
= max_t(int, tp
->rcv_nxt
- tp
->copied_seq
, 0);
2685 seq_printf(f
, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2686 "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n",
2687 i
, src
, srcp
, dest
, destp
, sk
->sk_state
,
2688 tp
->write_seq
- tp
->snd_una
,
2691 jiffies_delta_to_clock_t(timer_expires
- jiffies
),
2692 icsk
->icsk_retransmits
,
2693 from_kuid_munged(seq_user_ns(f
), sock_i_uid(sk
)),
2694 icsk
->icsk_probes_out
,
2696 atomic_read(&sk
->sk_refcnt
), sk
,
2697 jiffies_to_clock_t(icsk
->icsk_rto
),
2698 jiffies_to_clock_t(icsk
->icsk_ack
.ato
),
2699 (icsk
->icsk_ack
.quick
<< 1) | icsk
->icsk_ack
.pingpong
,
2701 sk
->sk_state
== TCP_LISTEN
?
2702 (fastopenq
? fastopenq
->max_qlen
: 0) :
2703 (tcp_in_initial_slowstart(tp
) ? -1 : tp
->snd_ssthresh
),
2707 static void get_timewait4_sock(const struct inet_timewait_sock
*tw
,
2708 struct seq_file
*f
, int i
, int *len
)
2712 long delta
= tw
->tw_ttd
- jiffies
;
2714 dest
= tw
->tw_daddr
;
2715 src
= tw
->tw_rcv_saddr
;
2716 destp
= ntohs(tw
->tw_dport
);
2717 srcp
= ntohs(tw
->tw_sport
);
2719 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2720 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
2721 i
, src
, srcp
, dest
, destp
, tw
->tw_substate
, 0, 0,
2722 3, jiffies_delta_to_clock_t(delta
), 0, 0, 0, 0,
2723 atomic_read(&tw
->tw_refcnt
), tw
, len
);
2728 static int tcp4_seq_show(struct seq_file
*seq
, void *v
)
2730 struct tcp_iter_state
*st
;
2733 if (v
== SEQ_START_TOKEN
) {
2734 seq_printf(seq
, "%-*s\n", TMPSZ
- 1,
2735 " sl local_address rem_address st tx_queue "
2736 "rx_queue tr tm->when retrnsmt uid timeout "
2742 switch (st
->state
) {
2743 case TCP_SEQ_STATE_LISTENING
:
2744 case TCP_SEQ_STATE_ESTABLISHED
:
2745 get_tcp4_sock(v
, seq
, st
->num
, &len
);
2747 case TCP_SEQ_STATE_OPENREQ
:
2748 get_openreq4(st
->syn_wait_sk
, v
, seq
, st
->num
, st
->uid
, &len
);
2750 case TCP_SEQ_STATE_TIME_WAIT
:
2751 get_timewait4_sock(v
, seq
, st
->num
, &len
);
2754 seq_printf(seq
, "%*s\n", TMPSZ
- 1 - len
, "");
2759 static const struct file_operations tcp_afinfo_seq_fops
= {
2760 .owner
= THIS_MODULE
,
2761 .open
= tcp_seq_open
,
2763 .llseek
= seq_lseek
,
2764 .release
= seq_release_net
2767 static struct tcp_seq_afinfo tcp4_seq_afinfo
= {
2770 .seq_fops
= &tcp_afinfo_seq_fops
,
2772 .show
= tcp4_seq_show
,
2776 static int __net_init
tcp4_proc_init_net(struct net
*net
)
2778 return tcp_proc_register(net
, &tcp4_seq_afinfo
);
2781 static void __net_exit
tcp4_proc_exit_net(struct net
*net
)
2783 tcp_proc_unregister(net
, &tcp4_seq_afinfo
);
2786 static struct pernet_operations tcp4_net_ops
= {
2787 .init
= tcp4_proc_init_net
,
2788 .exit
= tcp4_proc_exit_net
,
2791 int __init
tcp4_proc_init(void)
2793 return register_pernet_subsys(&tcp4_net_ops
);
2796 void tcp4_proc_exit(void)
2798 unregister_pernet_subsys(&tcp4_net_ops
);
2800 #endif /* CONFIG_PROC_FS */
2802 struct sk_buff
**tcp4_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
2804 const struct iphdr
*iph
= skb_gro_network_header(skb
);
2808 switch (skb
->ip_summed
) {
2809 case CHECKSUM_COMPLETE
:
2810 if (!tcp_v4_check(skb_gro_len(skb
), iph
->saddr
, iph
->daddr
,
2812 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2816 NAPI_GRO_CB(skb
)->flush
= 1;
2820 wsum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
2821 skb_gro_len(skb
), IPPROTO_TCP
, 0);
2822 sum
= csum_fold(skb_checksum(skb
,
2823 skb_gro_offset(skb
),
2829 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2833 return tcp_gro_receive(head
, skb
);
2836 int tcp4_gro_complete(struct sk_buff
*skb
)
2838 const struct iphdr
*iph
= ip_hdr(skb
);
2839 struct tcphdr
*th
= tcp_hdr(skb
);
2841 th
->check
= ~tcp_v4_check(skb
->len
- skb_transport_offset(skb
),
2842 iph
->saddr
, iph
->daddr
, 0);
2843 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
2845 return tcp_gro_complete(skb
);
2848 struct proto tcp_prot
= {
2850 .owner
= THIS_MODULE
,
2852 .connect
= tcp_v4_connect
,
2853 .disconnect
= tcp_disconnect
,
2854 .accept
= inet_csk_accept
,
2856 .init
= tcp_v4_init_sock
,
2857 .destroy
= tcp_v4_destroy_sock
,
2858 .shutdown
= tcp_shutdown
,
2859 .setsockopt
= tcp_setsockopt
,
2860 .getsockopt
= tcp_getsockopt
,
2861 .recvmsg
= tcp_recvmsg
,
2862 .sendmsg
= tcp_sendmsg
,
2863 .sendpage
= tcp_sendpage
,
2864 .backlog_rcv
= tcp_v4_do_rcv
,
2865 .release_cb
= tcp_release_cb
,
2866 .mtu_reduced
= tcp_v4_mtu_reduced
,
2868 .unhash
= inet_unhash
,
2869 .get_port
= inet_csk_get_port
,
2870 .enter_memory_pressure
= tcp_enter_memory_pressure
,
2871 .sockets_allocated
= &tcp_sockets_allocated
,
2872 .orphan_count
= &tcp_orphan_count
,
2873 .memory_allocated
= &tcp_memory_allocated
,
2874 .memory_pressure
= &tcp_memory_pressure
,
2875 .sysctl_wmem
= sysctl_tcp_wmem
,
2876 .sysctl_rmem
= sysctl_tcp_rmem
,
2877 .max_header
= MAX_TCP_HEADER
,
2878 .obj_size
= sizeof(struct tcp_sock
),
2879 .slab_flags
= SLAB_DESTROY_BY_RCU
,
2880 .twsk_prot
= &tcp_timewait_sock_ops
,
2881 .rsk_prot
= &tcp_request_sock_ops
,
2882 .h
.hashinfo
= &tcp_hashinfo
,
2883 .no_autobind
= true,
2884 #ifdef CONFIG_COMPAT
2885 .compat_setsockopt
= compat_tcp_setsockopt
,
2886 .compat_getsockopt
= compat_tcp_getsockopt
,
2888 #ifdef CONFIG_MEMCG_KMEM
2889 .init_cgroup
= tcp_init_cgroup
,
2890 .destroy_cgroup
= tcp_destroy_cgroup
,
2891 .proto_cgroup
= tcp_proto_cgroup
,
2894 EXPORT_SYMBOL(tcp_prot
);
2896 static int __net_init
tcp_sk_init(struct net
*net
)
2898 net
->ipv4
.sysctl_tcp_ecn
= 2;
2902 static void __net_exit
tcp_sk_exit(struct net
*net
)
2906 static void __net_exit
tcp_sk_exit_batch(struct list_head
*net_exit_list
)
2908 inet_twsk_purge(&tcp_hashinfo
, &tcp_death_row
, AF_INET
);
2911 static struct pernet_operations __net_initdata tcp_sk_ops
= {
2912 .init
= tcp_sk_init
,
2913 .exit
= tcp_sk_exit
,
2914 .exit_batch
= tcp_sk_exit_batch
,
2917 void __init
tcp_v4_init(void)
2919 inet_hashinfo_init(&tcp_hashinfo
);
2920 if (register_pernet_subsys(&tcp_sk_ops
))
2921 panic("Failed to create the TCP control socket.\n");