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.
54 #include <linux/bottom_half.h>
55 #include <linux/types.h>
56 #include <linux/fcntl.h>
57 #include <linux/module.h>
58 #include <linux/random.h>
59 #include <linux/cache.h>
60 #include <linux/jhash.h>
61 #include <linux/init.h>
62 #include <linux/times.h>
63 #include <linux/slab.h>
65 #include <net/net_namespace.h>
67 #include <net/inet_hashtables.h>
69 #include <net/transp_v6.h>
71 #include <net/inet_common.h>
72 #include <net/timewait_sock.h>
74 #include <net/netdma.h>
76 #include <linux/inet.h>
77 #include <linux/ipv6.h>
78 #include <linux/stddef.h>
79 #include <linux/proc_fs.h>
80 #include <linux/seq_file.h>
82 #include <linux/crypto.h>
83 #include <linux/scatterlist.h>
85 int sysctl_tcp_tw_reuse __read_mostly
;
86 int sysctl_tcp_low_latency __read_mostly
;
87 EXPORT_SYMBOL(sysctl_tcp_low_latency
);
90 #ifdef CONFIG_TCP_MD5SIG
91 static struct tcp_md5sig_key
*tcp_v4_md5_do_lookup(struct sock
*sk
,
93 static int tcp_v4_md5_hash_hdr(char *md5_hash
, struct tcp_md5sig_key
*key
,
94 __be32 daddr
, __be32 saddr
, struct tcphdr
*th
);
97 struct tcp_md5sig_key
*tcp_v4_md5_do_lookup(struct sock
*sk
, __be32 addr
)
103 struct inet_hashinfo tcp_hashinfo
;
104 EXPORT_SYMBOL(tcp_hashinfo
);
106 static inline __u32
tcp_v4_init_sequence(struct sk_buff
*skb
)
108 return secure_tcp_sequence_number(ip_hdr(skb
)->daddr
,
111 tcp_hdr(skb
)->source
);
114 int tcp_twsk_unique(struct sock
*sk
, struct sock
*sktw
, void *twp
)
116 const struct tcp_timewait_sock
*tcptw
= tcp_twsk(sktw
);
117 struct tcp_sock
*tp
= tcp_sk(sk
);
119 /* With PAWS, it is safe from the viewpoint
120 of data integrity. Even without PAWS it is safe provided sequence
121 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
123 Actually, the idea is close to VJ's one, only timestamp cache is
124 held not per host, but per port pair and TW bucket is used as state
127 If TW bucket has been already destroyed we fall back to VJ's scheme
128 and use initial timestamp retrieved from peer table.
130 if (tcptw
->tw_ts_recent_stamp
&&
131 (twp
== NULL
|| (sysctl_tcp_tw_reuse
&&
132 get_seconds() - tcptw
->tw_ts_recent_stamp
> 1))) {
133 tp
->write_seq
= tcptw
->tw_snd_nxt
+ 65535 + 2;
134 if (tp
->write_seq
== 0)
136 tp
->rx_opt
.ts_recent
= tcptw
->tw_ts_recent
;
137 tp
->rx_opt
.ts_recent_stamp
= tcptw
->tw_ts_recent_stamp
;
144 EXPORT_SYMBOL_GPL(tcp_twsk_unique
);
146 /* This will initiate an outgoing connection. */
147 int tcp_v4_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
)
149 struct sockaddr_in
*usin
= (struct sockaddr_in
*)uaddr
;
150 struct inet_sock
*inet
= inet_sk(sk
);
151 struct tcp_sock
*tp
= tcp_sk(sk
);
152 __be16 orig_sport
, orig_dport
;
153 __be32 daddr
, nexthop
;
157 struct ip_options_rcu
*inet_opt
;
159 if (addr_len
< sizeof(struct sockaddr_in
))
162 if (usin
->sin_family
!= AF_INET
)
163 return -EAFNOSUPPORT
;
165 nexthop
= daddr
= usin
->sin_addr
.s_addr
;
166 inet_opt
= rcu_dereference_protected(inet
->inet_opt
,
167 sock_owned_by_user(sk
));
168 if (inet_opt
&& inet_opt
->opt
.srr
) {
171 nexthop
= inet_opt
->opt
.faddr
;
174 orig_sport
= inet
->inet_sport
;
175 orig_dport
= usin
->sin_port
;
176 rt
= ip_route_connect(&fl4
, nexthop
, inet
->inet_saddr
,
177 RT_CONN_FLAGS(sk
), sk
->sk_bound_dev_if
,
179 orig_sport
, orig_dport
, sk
, true);
182 if (err
== -ENETUNREACH
)
183 IP_INC_STATS_BH(sock_net(sk
), IPSTATS_MIB_OUTNOROUTES
);
187 if (rt
->rt_flags
& (RTCF_MULTICAST
| RTCF_BROADCAST
)) {
192 if (!inet_opt
|| !inet_opt
->opt
.srr
)
195 if (!inet
->inet_saddr
)
196 inet
->inet_saddr
= rt
->rt_src
;
197 inet
->inet_rcv_saddr
= inet
->inet_saddr
;
199 if (tp
->rx_opt
.ts_recent_stamp
&& inet
->inet_daddr
!= daddr
) {
200 /* Reset inherited state */
201 tp
->rx_opt
.ts_recent
= 0;
202 tp
->rx_opt
.ts_recent_stamp
= 0;
206 if (tcp_death_row
.sysctl_tw_recycle
&&
207 !tp
->rx_opt
.ts_recent_stamp
&& rt
->rt_dst
== daddr
) {
208 struct inet_peer
*peer
= rt_get_peer(rt
);
210 * VJ's idea. We save last timestamp seen from
211 * the destination in peer table, when entering state
212 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
213 * when trying new connection.
216 inet_peer_refcheck(peer
);
217 if ((u32
)get_seconds() - peer
->tcp_ts_stamp
<= TCP_PAWS_MSL
) {
218 tp
->rx_opt
.ts_recent_stamp
= peer
->tcp_ts_stamp
;
219 tp
->rx_opt
.ts_recent
= peer
->tcp_ts
;
224 inet
->inet_dport
= usin
->sin_port
;
225 inet
->inet_daddr
= daddr
;
227 inet_csk(sk
)->icsk_ext_hdr_len
= 0;
229 inet_csk(sk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
231 tp
->rx_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
233 /* Socket identity is still unknown (sport may be zero).
234 * However we set state to SYN-SENT and not releasing socket
235 * lock select source port, enter ourselves into the hash tables and
236 * complete initialization after this.
238 tcp_set_state(sk
, TCP_SYN_SENT
);
239 err
= inet_hash_connect(&tcp_death_row
, sk
);
243 rt
= ip_route_newports(&fl4
, rt
, orig_sport
, orig_dport
,
244 inet
->inet_sport
, inet
->inet_dport
, sk
);
250 /* OK, now commit destination to socket. */
251 sk
->sk_gso_type
= SKB_GSO_TCPV4
;
252 sk_setup_caps(sk
, &rt
->dst
);
255 tp
->write_seq
= secure_tcp_sequence_number(inet
->inet_saddr
,
260 inet
->inet_id
= tp
->write_seq
^ jiffies
;
262 err
= tcp_connect(sk
);
271 * This unhashes the socket and releases the local port,
274 tcp_set_state(sk
, TCP_CLOSE
);
276 sk
->sk_route_caps
= 0;
277 inet
->inet_dport
= 0;
280 EXPORT_SYMBOL(tcp_v4_connect
);
283 * This routine does path mtu discovery as defined in RFC1191.
285 static void do_pmtu_discovery(struct sock
*sk
, const struct iphdr
*iph
, u32 mtu
)
287 struct dst_entry
*dst
;
288 struct inet_sock
*inet
= inet_sk(sk
);
290 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
291 * send out by Linux are always <576bytes so they should go through
294 if (sk
->sk_state
== TCP_LISTEN
)
297 /* We don't check in the destentry if pmtu discovery is forbidden
298 * on this route. We just assume that no packet_to_big packets
299 * are send back when pmtu discovery is not active.
300 * There is a small race when the user changes this flag in the
301 * route, but I think that's acceptable.
303 if ((dst
= __sk_dst_check(sk
, 0)) == NULL
)
306 dst
->ops
->update_pmtu(dst
, mtu
);
308 /* Something is about to be wrong... Remember soft error
309 * for the case, if this connection will not able to recover.
311 if (mtu
< dst_mtu(dst
) && ip_dont_fragment(sk
, dst
))
312 sk
->sk_err_soft
= EMSGSIZE
;
316 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
&&
317 inet_csk(sk
)->icsk_pmtu_cookie
> mtu
) {
318 tcp_sync_mss(sk
, mtu
);
320 /* Resend the TCP packet because it's
321 * clear that the old packet has been
322 * dropped. This is the new "fast" path mtu
325 tcp_simple_retransmit(sk
);
326 } /* else let the usual retransmit timer handle it */
330 * This routine is called by the ICMP module when it gets some
331 * sort of error condition. If err < 0 then the socket should
332 * be closed and the error returned to the user. If err > 0
333 * it's just the icmp type << 8 | icmp code. After adjustment
334 * header points to the first 8 bytes of the tcp header. We need
335 * to find the appropriate port.
337 * The locking strategy used here is very "optimistic". When
338 * someone else accesses the socket the ICMP is just dropped
339 * and for some paths there is no check at all.
340 * A more general error queue to queue errors for later handling
341 * is probably better.
345 void tcp_v4_err(struct sk_buff
*icmp_skb
, u32 info
)
347 const struct iphdr
*iph
= (const struct iphdr
*)icmp_skb
->data
;
348 struct tcphdr
*th
= (struct tcphdr
*)(icmp_skb
->data
+ (iph
->ihl
<< 2));
349 struct inet_connection_sock
*icsk
;
351 struct inet_sock
*inet
;
352 const int type
= icmp_hdr(icmp_skb
)->type
;
353 const int code
= icmp_hdr(icmp_skb
)->code
;
359 struct net
*net
= dev_net(icmp_skb
->dev
);
361 if (icmp_skb
->len
< (iph
->ihl
<< 2) + 8) {
362 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
366 sk
= inet_lookup(net
, &tcp_hashinfo
, iph
->daddr
, th
->dest
,
367 iph
->saddr
, th
->source
, inet_iif(icmp_skb
));
369 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
372 if (sk
->sk_state
== TCP_TIME_WAIT
) {
373 inet_twsk_put(inet_twsk(sk
));
378 /* If too many ICMPs get dropped on busy
379 * servers this needs to be solved differently.
381 if (sock_owned_by_user(sk
))
382 NET_INC_STATS_BH(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
384 if (sk
->sk_state
== TCP_CLOSE
)
387 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
388 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
394 seq
= ntohl(th
->seq
);
395 if (sk
->sk_state
!= TCP_LISTEN
&&
396 !between(seq
, tp
->snd_una
, tp
->snd_nxt
)) {
397 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
402 case ICMP_SOURCE_QUENCH
:
403 /* Just silently ignore these. */
405 case ICMP_PARAMETERPROB
:
408 case ICMP_DEST_UNREACH
:
409 if (code
> NR_ICMP_UNREACH
)
412 if (code
== ICMP_FRAG_NEEDED
) { /* PMTU discovery (RFC1191) */
413 if (!sock_owned_by_user(sk
))
414 do_pmtu_discovery(sk
, iph
, info
);
418 err
= icmp_err_convert
[code
].errno
;
419 /* check if icmp_skb allows revert of backoff
420 * (see draft-zimmermann-tcp-lcd) */
421 if (code
!= ICMP_NET_UNREACH
&& code
!= ICMP_HOST_UNREACH
)
423 if (seq
!= tp
->snd_una
|| !icsk
->icsk_retransmits
||
427 if (sock_owned_by_user(sk
))
430 icsk
->icsk_backoff
--;
431 inet_csk(sk
)->icsk_rto
= __tcp_set_rto(tp
) <<
435 skb
= tcp_write_queue_head(sk
);
438 remaining
= icsk
->icsk_rto
- min(icsk
->icsk_rto
,
439 tcp_time_stamp
- TCP_SKB_CB(skb
)->when
);
442 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
443 remaining
, TCP_RTO_MAX
);
445 /* RTO revert clocked out retransmission.
446 * Will retransmit now */
447 tcp_retransmit_timer(sk
);
451 case ICMP_TIME_EXCEEDED
:
458 switch (sk
->sk_state
) {
459 struct request_sock
*req
, **prev
;
461 if (sock_owned_by_user(sk
))
464 req
= inet_csk_search_req(sk
, &prev
, th
->dest
,
465 iph
->daddr
, iph
->saddr
);
469 /* ICMPs are not backlogged, hence we cannot get
470 an established socket here.
474 if (seq
!= tcp_rsk(req
)->snt_isn
) {
475 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
480 * Still in SYN_RECV, just remove it silently.
481 * There is no good way to pass the error to the newly
482 * created socket, and POSIX does not want network
483 * errors returned from accept().
485 inet_csk_reqsk_queue_drop(sk
, req
, prev
);
489 case TCP_SYN_RECV
: /* Cannot happen.
490 It can f.e. if SYNs crossed.
492 if (!sock_owned_by_user(sk
)) {
495 sk
->sk_error_report(sk
);
499 sk
->sk_err_soft
= err
;
504 /* If we've already connected we will keep trying
505 * until we time out, or the user gives up.
507 * rfc1122 4.2.3.9 allows to consider as hard errors
508 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
509 * but it is obsoleted by pmtu discovery).
511 * Note, that in modern internet, where routing is unreliable
512 * and in each dark corner broken firewalls sit, sending random
513 * errors ordered by their masters even this two messages finally lose
514 * their original sense (even Linux sends invalid PORT_UNREACHs)
516 * Now we are in compliance with RFCs.
521 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
523 sk
->sk_error_report(sk
);
524 } else { /* Only an error on timeout */
525 sk
->sk_err_soft
= err
;
533 static void __tcp_v4_send_check(struct sk_buff
*skb
,
534 __be32 saddr
, __be32 daddr
)
536 struct tcphdr
*th
= tcp_hdr(skb
);
538 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
539 th
->check
= ~tcp_v4_check(skb
->len
, saddr
, daddr
, 0);
540 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
541 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
543 th
->check
= tcp_v4_check(skb
->len
, saddr
, daddr
,
550 /* This routine computes an IPv4 TCP checksum. */
551 void tcp_v4_send_check(struct sock
*sk
, struct sk_buff
*skb
)
553 struct inet_sock
*inet
= inet_sk(sk
);
555 __tcp_v4_send_check(skb
, inet
->inet_saddr
, inet
->inet_daddr
);
557 EXPORT_SYMBOL(tcp_v4_send_check
);
559 int tcp_v4_gso_send_check(struct sk_buff
*skb
)
561 const struct iphdr
*iph
;
564 if (!pskb_may_pull(skb
, sizeof(*th
)))
571 skb
->ip_summed
= CHECKSUM_PARTIAL
;
572 __tcp_v4_send_check(skb
, iph
->saddr
, iph
->daddr
);
577 * This routine will send an RST to the other tcp.
579 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
581 * Answer: if a packet caused RST, it is not for a socket
582 * existing in our system, if it is matched to a socket,
583 * it is just duplicate segment or bug in other side's TCP.
584 * So that we build reply only basing on parameters
585 * arrived with segment.
586 * Exception: precedence violation. We do not implement it in any case.
589 static void tcp_v4_send_reset(struct sock
*sk
, struct sk_buff
*skb
)
591 struct tcphdr
*th
= tcp_hdr(skb
);
594 #ifdef CONFIG_TCP_MD5SIG
595 __be32 opt
[(TCPOLEN_MD5SIG_ALIGNED
>> 2)];
598 struct ip_reply_arg arg
;
599 #ifdef CONFIG_TCP_MD5SIG
600 struct tcp_md5sig_key
*key
;
604 /* Never send a reset in response to a reset. */
608 if (skb_rtable(skb
)->rt_type
!= RTN_LOCAL
)
611 /* Swap the send and the receive. */
612 memset(&rep
, 0, sizeof(rep
));
613 rep
.th
.dest
= th
->source
;
614 rep
.th
.source
= th
->dest
;
615 rep
.th
.doff
= sizeof(struct tcphdr
) / 4;
619 rep
.th
.seq
= th
->ack_seq
;
622 rep
.th
.ack_seq
= htonl(ntohl(th
->seq
) + th
->syn
+ th
->fin
+
623 skb
->len
- (th
->doff
<< 2));
626 memset(&arg
, 0, sizeof(arg
));
627 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
628 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
630 #ifdef CONFIG_TCP_MD5SIG
631 key
= sk
? tcp_v4_md5_do_lookup(sk
, ip_hdr(skb
)->daddr
) : NULL
;
633 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) |
635 (TCPOPT_MD5SIG
<< 8) |
637 /* Update length and the length the header thinks exists */
638 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
639 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
641 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[1],
642 key
, ip_hdr(skb
)->saddr
,
643 ip_hdr(skb
)->daddr
, &rep
.th
);
646 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
647 ip_hdr(skb
)->saddr
, /* XXX */
648 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
649 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
650 arg
.flags
= (sk
&& inet_sk(sk
)->transparent
) ? IP_REPLY_ARG_NOSRCCHECK
: 0;
652 net
= dev_net(skb_dst(skb
)->dev
);
653 ip_send_reply(net
->ipv4
.tcp_sock
, skb
,
654 &arg
, arg
.iov
[0].iov_len
);
656 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
657 TCP_INC_STATS_BH(net
, TCP_MIB_OUTRSTS
);
660 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
661 outside socket context is ugly, certainly. What can I do?
664 static void tcp_v4_send_ack(struct sk_buff
*skb
, u32 seq
, u32 ack
,
665 u32 win
, u32 ts
, int oif
,
666 struct tcp_md5sig_key
*key
,
669 struct tcphdr
*th
= tcp_hdr(skb
);
672 __be32 opt
[(TCPOLEN_TSTAMP_ALIGNED
>> 2)
673 #ifdef CONFIG_TCP_MD5SIG
674 + (TCPOLEN_MD5SIG_ALIGNED
>> 2)
678 struct ip_reply_arg arg
;
679 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
681 memset(&rep
.th
, 0, sizeof(struct tcphdr
));
682 memset(&arg
, 0, sizeof(arg
));
684 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
685 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
687 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) | (TCPOPT_NOP
<< 16) |
688 (TCPOPT_TIMESTAMP
<< 8) |
690 rep
.opt
[1] = htonl(tcp_time_stamp
);
691 rep
.opt
[2] = htonl(ts
);
692 arg
.iov
[0].iov_len
+= TCPOLEN_TSTAMP_ALIGNED
;
695 /* Swap the send and the receive. */
696 rep
.th
.dest
= th
->source
;
697 rep
.th
.source
= th
->dest
;
698 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
699 rep
.th
.seq
= htonl(seq
);
700 rep
.th
.ack_seq
= htonl(ack
);
702 rep
.th
.window
= htons(win
);
704 #ifdef CONFIG_TCP_MD5SIG
706 int offset
= (ts
) ? 3 : 0;
708 rep
.opt
[offset
++] = htonl((TCPOPT_NOP
<< 24) |
710 (TCPOPT_MD5SIG
<< 8) |
712 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
713 rep
.th
.doff
= arg
.iov
[0].iov_len
/4;
715 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[offset
],
716 key
, ip_hdr(skb
)->saddr
,
717 ip_hdr(skb
)->daddr
, &rep
.th
);
720 arg
.flags
= reply_flags
;
721 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
722 ip_hdr(skb
)->saddr
, /* XXX */
723 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
724 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
726 arg
.bound_dev_if
= oif
;
728 ip_send_reply(net
->ipv4
.tcp_sock
, skb
,
729 &arg
, arg
.iov
[0].iov_len
);
731 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
734 static void tcp_v4_timewait_ack(struct sock
*sk
, struct sk_buff
*skb
)
736 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
737 struct tcp_timewait_sock
*tcptw
= tcp_twsk(sk
);
739 tcp_v4_send_ack(skb
, tcptw
->tw_snd_nxt
, tcptw
->tw_rcv_nxt
,
740 tcptw
->tw_rcv_wnd
>> tw
->tw_rcv_wscale
,
743 tcp_twsk_md5_key(tcptw
),
744 tw
->tw_transparent
? IP_REPLY_ARG_NOSRCCHECK
: 0
750 static void tcp_v4_reqsk_send_ack(struct sock
*sk
, struct sk_buff
*skb
,
751 struct request_sock
*req
)
753 tcp_v4_send_ack(skb
, tcp_rsk(req
)->snt_isn
+ 1,
754 tcp_rsk(req
)->rcv_isn
+ 1, req
->rcv_wnd
,
757 tcp_v4_md5_do_lookup(sk
, ip_hdr(skb
)->daddr
),
758 inet_rsk(req
)->no_srccheck
? IP_REPLY_ARG_NOSRCCHECK
: 0);
762 * Send a SYN-ACK after having received a SYN.
763 * This still operates on a request_sock only, not on a big
766 static int tcp_v4_send_synack(struct sock
*sk
, struct dst_entry
*dst
,
767 struct request_sock
*req
,
768 struct request_values
*rvp
)
770 const struct inet_request_sock
*ireq
= inet_rsk(req
);
772 struct sk_buff
* skb
;
774 /* First, grab a route. */
775 if (!dst
&& (dst
= inet_csk_route_req(sk
, req
)) == NULL
)
778 skb
= tcp_make_synack(sk
, dst
, req
, rvp
);
781 __tcp_v4_send_check(skb
, ireq
->loc_addr
, ireq
->rmt_addr
);
783 err
= ip_build_and_send_pkt(skb
, sk
, ireq
->loc_addr
,
786 err
= net_xmit_eval(err
);
793 static int tcp_v4_rtx_synack(struct sock
*sk
, struct request_sock
*req
,
794 struct request_values
*rvp
)
796 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_RETRANSSEGS
);
797 return tcp_v4_send_synack(sk
, NULL
, req
, rvp
);
801 * IPv4 request_sock destructor.
803 static void tcp_v4_reqsk_destructor(struct request_sock
*req
)
805 kfree(inet_rsk(req
)->opt
);
808 static void syn_flood_warning(const struct sk_buff
*skb
)
812 #ifdef CONFIG_SYN_COOKIES
813 if (sysctl_tcp_syncookies
)
814 msg
= "Sending cookies";
817 msg
= "Dropping request";
819 pr_info("TCP: Possible SYN flooding on port %d. %s.\n",
820 ntohs(tcp_hdr(skb
)->dest
), msg
);
824 * Save and compile IPv4 options into the request_sock if needed.
826 static struct ip_options_rcu
*tcp_v4_save_options(struct sock
*sk
,
829 const struct ip_options
*opt
= &(IPCB(skb
)->opt
);
830 struct ip_options_rcu
*dopt
= NULL
;
832 if (opt
&& opt
->optlen
) {
833 int opt_size
= sizeof(*dopt
) + opt
->optlen
;
835 dopt
= kmalloc(opt_size
, GFP_ATOMIC
);
837 if (ip_options_echo(&dopt
->opt
, skb
)) {
846 #ifdef CONFIG_TCP_MD5SIG
848 * RFC2385 MD5 checksumming requires a mapping of
849 * IP address->MD5 Key.
850 * We need to maintain these in the sk structure.
853 /* Find the Key structure for an address. */
854 static struct tcp_md5sig_key
*
855 tcp_v4_md5_do_lookup(struct sock
*sk
, __be32 addr
)
857 struct tcp_sock
*tp
= tcp_sk(sk
);
860 if (!tp
->md5sig_info
|| !tp
->md5sig_info
->entries4
)
862 for (i
= 0; i
< tp
->md5sig_info
->entries4
; i
++) {
863 if (tp
->md5sig_info
->keys4
[i
].addr
== addr
)
864 return &tp
->md5sig_info
->keys4
[i
].base
;
869 struct tcp_md5sig_key
*tcp_v4_md5_lookup(struct sock
*sk
,
870 struct sock
*addr_sk
)
872 return tcp_v4_md5_do_lookup(sk
, inet_sk(addr_sk
)->inet_daddr
);
874 EXPORT_SYMBOL(tcp_v4_md5_lookup
);
876 static struct tcp_md5sig_key
*tcp_v4_reqsk_md5_lookup(struct sock
*sk
,
877 struct request_sock
*req
)
879 return tcp_v4_md5_do_lookup(sk
, inet_rsk(req
)->rmt_addr
);
882 /* This can be called on a newly created socket, from other files */
883 int tcp_v4_md5_do_add(struct sock
*sk
, __be32 addr
,
884 u8
*newkey
, u8 newkeylen
)
886 /* Add Key to the list */
887 struct tcp_md5sig_key
*key
;
888 struct tcp_sock
*tp
= tcp_sk(sk
);
889 struct tcp4_md5sig_key
*keys
;
891 key
= tcp_v4_md5_do_lookup(sk
, addr
);
893 /* Pre-existing entry - just update that one. */
896 key
->keylen
= newkeylen
;
898 struct tcp_md5sig_info
*md5sig
;
900 if (!tp
->md5sig_info
) {
901 tp
->md5sig_info
= kzalloc(sizeof(*tp
->md5sig_info
),
903 if (!tp
->md5sig_info
) {
907 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
909 if (tcp_alloc_md5sig_pool(sk
) == NULL
) {
913 md5sig
= tp
->md5sig_info
;
915 if (md5sig
->alloced4
== md5sig
->entries4
) {
916 keys
= kmalloc((sizeof(*keys
) *
917 (md5sig
->entries4
+ 1)), GFP_ATOMIC
);
920 tcp_free_md5sig_pool();
924 if (md5sig
->entries4
)
925 memcpy(keys
, md5sig
->keys4
,
926 sizeof(*keys
) * md5sig
->entries4
);
928 /* Free old key list, and reference new one */
929 kfree(md5sig
->keys4
);
930 md5sig
->keys4
= keys
;
934 md5sig
->keys4
[md5sig
->entries4
- 1].addr
= addr
;
935 md5sig
->keys4
[md5sig
->entries4
- 1].base
.key
= newkey
;
936 md5sig
->keys4
[md5sig
->entries4
- 1].base
.keylen
= newkeylen
;
940 EXPORT_SYMBOL(tcp_v4_md5_do_add
);
942 static int tcp_v4_md5_add_func(struct sock
*sk
, struct sock
*addr_sk
,
943 u8
*newkey
, u8 newkeylen
)
945 return tcp_v4_md5_do_add(sk
, inet_sk(addr_sk
)->inet_daddr
,
949 int tcp_v4_md5_do_del(struct sock
*sk
, __be32 addr
)
951 struct tcp_sock
*tp
= tcp_sk(sk
);
954 for (i
= 0; i
< tp
->md5sig_info
->entries4
; i
++) {
955 if (tp
->md5sig_info
->keys4
[i
].addr
== addr
) {
957 kfree(tp
->md5sig_info
->keys4
[i
].base
.key
);
958 tp
->md5sig_info
->entries4
--;
960 if (tp
->md5sig_info
->entries4
== 0) {
961 kfree(tp
->md5sig_info
->keys4
);
962 tp
->md5sig_info
->keys4
= NULL
;
963 tp
->md5sig_info
->alloced4
= 0;
964 } else if (tp
->md5sig_info
->entries4
!= i
) {
965 /* Need to do some manipulation */
966 memmove(&tp
->md5sig_info
->keys4
[i
],
967 &tp
->md5sig_info
->keys4
[i
+1],
968 (tp
->md5sig_info
->entries4
- i
) *
969 sizeof(struct tcp4_md5sig_key
));
971 tcp_free_md5sig_pool();
977 EXPORT_SYMBOL(tcp_v4_md5_do_del
);
979 static void tcp_v4_clear_md5_list(struct sock
*sk
)
981 struct tcp_sock
*tp
= tcp_sk(sk
);
983 /* Free each key, then the set of key keys,
984 * the crypto element, and then decrement our
985 * hold on the last resort crypto.
987 if (tp
->md5sig_info
->entries4
) {
989 for (i
= 0; i
< tp
->md5sig_info
->entries4
; i
++)
990 kfree(tp
->md5sig_info
->keys4
[i
].base
.key
);
991 tp
->md5sig_info
->entries4
= 0;
992 tcp_free_md5sig_pool();
994 if (tp
->md5sig_info
->keys4
) {
995 kfree(tp
->md5sig_info
->keys4
);
996 tp
->md5sig_info
->keys4
= NULL
;
997 tp
->md5sig_info
->alloced4
= 0;
1001 static int tcp_v4_parse_md5_keys(struct sock
*sk
, char __user
*optval
,
1004 struct tcp_md5sig cmd
;
1005 struct sockaddr_in
*sin
= (struct sockaddr_in
*)&cmd
.tcpm_addr
;
1008 if (optlen
< sizeof(cmd
))
1011 if (copy_from_user(&cmd
, optval
, sizeof(cmd
)))
1014 if (sin
->sin_family
!= AF_INET
)
1017 if (!cmd
.tcpm_key
|| !cmd
.tcpm_keylen
) {
1018 if (!tcp_sk(sk
)->md5sig_info
)
1020 return tcp_v4_md5_do_del(sk
, sin
->sin_addr
.s_addr
);
1023 if (cmd
.tcpm_keylen
> TCP_MD5SIG_MAXKEYLEN
)
1026 if (!tcp_sk(sk
)->md5sig_info
) {
1027 struct tcp_sock
*tp
= tcp_sk(sk
);
1028 struct tcp_md5sig_info
*p
;
1030 p
= kzalloc(sizeof(*p
), sk
->sk_allocation
);
1034 tp
->md5sig_info
= p
;
1035 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
1038 newkey
= kmemdup(cmd
.tcpm_key
, cmd
.tcpm_keylen
, sk
->sk_allocation
);
1041 return tcp_v4_md5_do_add(sk
, sin
->sin_addr
.s_addr
,
1042 newkey
, cmd
.tcpm_keylen
);
1045 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool
*hp
,
1046 __be32 daddr
, __be32 saddr
, int nbytes
)
1048 struct tcp4_pseudohdr
*bp
;
1049 struct scatterlist sg
;
1051 bp
= &hp
->md5_blk
.ip4
;
1054 * 1. the TCP pseudo-header (in the order: source IP address,
1055 * destination IP address, zero-padded protocol number, and
1061 bp
->protocol
= IPPROTO_TCP
;
1062 bp
->len
= cpu_to_be16(nbytes
);
1064 sg_init_one(&sg
, bp
, sizeof(*bp
));
1065 return crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(*bp
));
1068 static int tcp_v4_md5_hash_hdr(char *md5_hash
, struct tcp_md5sig_key
*key
,
1069 __be32 daddr
, __be32 saddr
, struct tcphdr
*th
)
1071 struct tcp_md5sig_pool
*hp
;
1072 struct hash_desc
*desc
;
1074 hp
= tcp_get_md5sig_pool();
1076 goto clear_hash_noput
;
1077 desc
= &hp
->md5_desc
;
1079 if (crypto_hash_init(desc
))
1081 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, th
->doff
<< 2))
1083 if (tcp_md5_hash_header(hp
, th
))
1085 if (tcp_md5_hash_key(hp
, key
))
1087 if (crypto_hash_final(desc
, md5_hash
))
1090 tcp_put_md5sig_pool();
1094 tcp_put_md5sig_pool();
1096 memset(md5_hash
, 0, 16);
1100 int tcp_v4_md5_hash_skb(char *md5_hash
, struct tcp_md5sig_key
*key
,
1101 struct sock
*sk
, struct request_sock
*req
,
1102 struct sk_buff
*skb
)
1104 struct tcp_md5sig_pool
*hp
;
1105 struct hash_desc
*desc
;
1106 struct tcphdr
*th
= tcp_hdr(skb
);
1107 __be32 saddr
, daddr
;
1110 saddr
= inet_sk(sk
)->inet_saddr
;
1111 daddr
= inet_sk(sk
)->inet_daddr
;
1113 saddr
= inet_rsk(req
)->loc_addr
;
1114 daddr
= inet_rsk(req
)->rmt_addr
;
1116 const struct iphdr
*iph
= ip_hdr(skb
);
1121 hp
= tcp_get_md5sig_pool();
1123 goto clear_hash_noput
;
1124 desc
= &hp
->md5_desc
;
1126 if (crypto_hash_init(desc
))
1129 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, skb
->len
))
1131 if (tcp_md5_hash_header(hp
, th
))
1133 if (tcp_md5_hash_skb_data(hp
, skb
, th
->doff
<< 2))
1135 if (tcp_md5_hash_key(hp
, key
))
1137 if (crypto_hash_final(desc
, md5_hash
))
1140 tcp_put_md5sig_pool();
1144 tcp_put_md5sig_pool();
1146 memset(md5_hash
, 0, 16);
1149 EXPORT_SYMBOL(tcp_v4_md5_hash_skb
);
1151 static int tcp_v4_inbound_md5_hash(struct sock
*sk
, struct sk_buff
*skb
)
1154 * This gets called for each TCP segment that arrives
1155 * so we want to be efficient.
1156 * We have 3 drop cases:
1157 * o No MD5 hash and one expected.
1158 * o MD5 hash and we're not expecting one.
1159 * o MD5 hash and its wrong.
1161 __u8
*hash_location
= NULL
;
1162 struct tcp_md5sig_key
*hash_expected
;
1163 const struct iphdr
*iph
= ip_hdr(skb
);
1164 struct tcphdr
*th
= tcp_hdr(skb
);
1166 unsigned char newhash
[16];
1168 hash_expected
= tcp_v4_md5_do_lookup(sk
, iph
->saddr
);
1169 hash_location
= tcp_parse_md5sig_option(th
);
1171 /* We've parsed the options - do we have a hash? */
1172 if (!hash_expected
&& !hash_location
)
1175 if (hash_expected
&& !hash_location
) {
1176 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5NOTFOUND
);
1180 if (!hash_expected
&& hash_location
) {
1181 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5UNEXPECTED
);
1185 /* Okay, so this is hash_expected and hash_location -
1186 * so we need to calculate the checksum.
1188 genhash
= tcp_v4_md5_hash_skb(newhash
,
1192 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0) {
1193 if (net_ratelimit()) {
1194 printk(KERN_INFO
"MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1195 &iph
->saddr
, ntohs(th
->source
),
1196 &iph
->daddr
, ntohs(th
->dest
),
1197 genhash
? " tcp_v4_calc_md5_hash failed" : "");
1206 struct request_sock_ops tcp_request_sock_ops __read_mostly
= {
1208 .obj_size
= sizeof(struct tcp_request_sock
),
1209 .rtx_syn_ack
= tcp_v4_rtx_synack
,
1210 .send_ack
= tcp_v4_reqsk_send_ack
,
1211 .destructor
= tcp_v4_reqsk_destructor
,
1212 .send_reset
= tcp_v4_send_reset
,
1213 .syn_ack_timeout
= tcp_syn_ack_timeout
,
1216 #ifdef CONFIG_TCP_MD5SIG
1217 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops
= {
1218 .md5_lookup
= tcp_v4_reqsk_md5_lookup
,
1219 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1223 int tcp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
)
1225 struct tcp_extend_values tmp_ext
;
1226 struct tcp_options_received tmp_opt
;
1228 struct request_sock
*req
;
1229 struct inet_request_sock
*ireq
;
1230 struct tcp_sock
*tp
= tcp_sk(sk
);
1231 struct dst_entry
*dst
= NULL
;
1232 __be32 saddr
= ip_hdr(skb
)->saddr
;
1233 __be32 daddr
= ip_hdr(skb
)->daddr
;
1234 __u32 isn
= TCP_SKB_CB(skb
)->when
;
1235 #ifdef CONFIG_SYN_COOKIES
1236 int want_cookie
= 0;
1238 #define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
1241 /* Never answer to SYNs send to broadcast or multicast */
1242 if (skb_rtable(skb
)->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
))
1245 /* TW buckets are converted to open requests without
1246 * limitations, they conserve resources and peer is
1247 * evidently real one.
1249 if (inet_csk_reqsk_queue_is_full(sk
) && !isn
) {
1250 if (net_ratelimit())
1251 syn_flood_warning(skb
);
1252 #ifdef CONFIG_SYN_COOKIES
1253 if (sysctl_tcp_syncookies
) {
1260 /* Accept backlog is full. If we have already queued enough
1261 * of warm entries in syn queue, drop request. It is better than
1262 * clogging syn queue with openreqs with exponentially increasing
1265 if (sk_acceptq_is_full(sk
) && inet_csk_reqsk_queue_young(sk
) > 1)
1268 req
= inet_reqsk_alloc(&tcp_request_sock_ops
);
1272 #ifdef CONFIG_TCP_MD5SIG
1273 tcp_rsk(req
)->af_specific
= &tcp_request_sock_ipv4_ops
;
1276 tcp_clear_options(&tmp_opt
);
1277 tmp_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
1278 tmp_opt
.user_mss
= tp
->rx_opt
.user_mss
;
1279 tcp_parse_options(skb
, &tmp_opt
, &hash_location
, 0);
1281 if (tmp_opt
.cookie_plus
> 0 &&
1282 tmp_opt
.saw_tstamp
&&
1283 !tp
->rx_opt
.cookie_out_never
&&
1284 (sysctl_tcp_cookie_size
> 0 ||
1285 (tp
->cookie_values
!= NULL
&&
1286 tp
->cookie_values
->cookie_desired
> 0))) {
1288 u32
*mess
= &tmp_ext
.cookie_bakery
[COOKIE_DIGEST_WORDS
];
1289 int l
= tmp_opt
.cookie_plus
- TCPOLEN_COOKIE_BASE
;
1291 if (tcp_cookie_generator(&tmp_ext
.cookie_bakery
[0]) != 0)
1292 goto drop_and_release
;
1294 /* Secret recipe starts with IP addresses */
1295 *mess
++ ^= (__force u32
)daddr
;
1296 *mess
++ ^= (__force u32
)saddr
;
1298 /* plus variable length Initiator Cookie */
1301 *c
++ ^= *hash_location
++;
1303 #ifdef CONFIG_SYN_COOKIES
1304 want_cookie
= 0; /* not our kind of cookie */
1306 tmp_ext
.cookie_out_never
= 0; /* false */
1307 tmp_ext
.cookie_plus
= tmp_opt
.cookie_plus
;
1308 } else if (!tp
->rx_opt
.cookie_in_always
) {
1309 /* redundant indications, but ensure initialization. */
1310 tmp_ext
.cookie_out_never
= 1; /* true */
1311 tmp_ext
.cookie_plus
= 0;
1313 goto drop_and_release
;
1315 tmp_ext
.cookie_in_always
= tp
->rx_opt
.cookie_in_always
;
1317 if (want_cookie
&& !tmp_opt
.saw_tstamp
)
1318 tcp_clear_options(&tmp_opt
);
1320 tmp_opt
.tstamp_ok
= tmp_opt
.saw_tstamp
;
1321 tcp_openreq_init(req
, &tmp_opt
, skb
);
1323 ireq
= inet_rsk(req
);
1324 ireq
->loc_addr
= daddr
;
1325 ireq
->rmt_addr
= saddr
;
1326 ireq
->no_srccheck
= inet_sk(sk
)->transparent
;
1327 ireq
->opt
= tcp_v4_save_options(sk
, skb
);
1329 if (security_inet_conn_request(sk
, skb
, req
))
1332 if (!want_cookie
|| tmp_opt
.tstamp_ok
)
1333 TCP_ECN_create_request(req
, tcp_hdr(skb
));
1336 isn
= cookie_v4_init_sequence(sk
, skb
, &req
->mss
);
1337 req
->cookie_ts
= tmp_opt
.tstamp_ok
;
1339 struct inet_peer
*peer
= NULL
;
1341 /* VJ's idea. We save last timestamp seen
1342 * from the destination in peer table, when entering
1343 * state TIME-WAIT, and check against it before
1344 * accepting new connection request.
1346 * If "isn" is not zero, this request hit alive
1347 * timewait bucket, so that all the necessary checks
1348 * are made in the function processing timewait state.
1350 if (tmp_opt
.saw_tstamp
&&
1351 tcp_death_row
.sysctl_tw_recycle
&&
1352 (dst
= inet_csk_route_req(sk
, req
)) != NULL
&&
1353 (peer
= rt_get_peer((struct rtable
*)dst
)) != NULL
&&
1354 peer
->daddr
.addr
.a4
== saddr
) {
1355 inet_peer_refcheck(peer
);
1356 if ((u32
)get_seconds() - peer
->tcp_ts_stamp
< TCP_PAWS_MSL
&&
1357 (s32
)(peer
->tcp_ts
- req
->ts_recent
) >
1359 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_PAWSPASSIVEREJECTED
);
1360 goto drop_and_release
;
1363 /* Kill the following clause, if you dislike this way. */
1364 else if (!sysctl_tcp_syncookies
&&
1365 (sysctl_max_syn_backlog
- inet_csk_reqsk_queue_len(sk
) <
1366 (sysctl_max_syn_backlog
>> 2)) &&
1367 (!peer
|| !peer
->tcp_ts_stamp
) &&
1368 (!dst
|| !dst_metric(dst
, RTAX_RTT
))) {
1369 /* Without syncookies last quarter of
1370 * backlog is filled with destinations,
1371 * proven to be alive.
1372 * It means that we continue to communicate
1373 * to destinations, already remembered
1374 * to the moment of synflood.
1376 LIMIT_NETDEBUG(KERN_DEBUG
"TCP: drop open request from %pI4/%u\n",
1377 &saddr
, ntohs(tcp_hdr(skb
)->source
));
1378 goto drop_and_release
;
1381 isn
= tcp_v4_init_sequence(skb
);
1383 tcp_rsk(req
)->snt_isn
= isn
;
1385 if (tcp_v4_send_synack(sk
, dst
, req
,
1386 (struct request_values
*)&tmp_ext
) ||
1390 inet_csk_reqsk_queue_hash_add(sk
, req
, TCP_TIMEOUT_INIT
);
1400 EXPORT_SYMBOL(tcp_v4_conn_request
);
1404 * The three way handshake has completed - we got a valid synack -
1405 * now create the new socket.
1407 struct sock
*tcp_v4_syn_recv_sock(struct sock
*sk
, struct sk_buff
*skb
,
1408 struct request_sock
*req
,
1409 struct dst_entry
*dst
)
1411 struct inet_request_sock
*ireq
;
1412 struct inet_sock
*newinet
;
1413 struct tcp_sock
*newtp
;
1415 #ifdef CONFIG_TCP_MD5SIG
1416 struct tcp_md5sig_key
*key
;
1418 struct ip_options_rcu
*inet_opt
;
1420 if (sk_acceptq_is_full(sk
))
1423 if (!dst
&& (dst
= inet_csk_route_req(sk
, req
)) == NULL
)
1426 newsk
= tcp_create_openreq_child(sk
, req
, skb
);
1430 newsk
->sk_gso_type
= SKB_GSO_TCPV4
;
1431 sk_setup_caps(newsk
, dst
);
1433 newtp
= tcp_sk(newsk
);
1434 newinet
= inet_sk(newsk
);
1435 ireq
= inet_rsk(req
);
1436 newinet
->inet_daddr
= ireq
->rmt_addr
;
1437 newinet
->inet_rcv_saddr
= ireq
->loc_addr
;
1438 newinet
->inet_saddr
= ireq
->loc_addr
;
1439 inet_opt
= ireq
->opt
;
1440 rcu_assign_pointer(newinet
->inet_opt
, inet_opt
);
1442 newinet
->mc_index
= inet_iif(skb
);
1443 newinet
->mc_ttl
= ip_hdr(skb
)->ttl
;
1444 inet_csk(newsk
)->icsk_ext_hdr_len
= 0;
1446 inet_csk(newsk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
1447 newinet
->inet_id
= newtp
->write_seq
^ jiffies
;
1449 tcp_mtup_init(newsk
);
1450 tcp_sync_mss(newsk
, dst_mtu(dst
));
1451 newtp
->advmss
= dst_metric_advmss(dst
);
1452 if (tcp_sk(sk
)->rx_opt
.user_mss
&&
1453 tcp_sk(sk
)->rx_opt
.user_mss
< newtp
->advmss
)
1454 newtp
->advmss
= tcp_sk(sk
)->rx_opt
.user_mss
;
1456 tcp_initialize_rcv_mss(newsk
);
1458 #ifdef CONFIG_TCP_MD5SIG
1459 /* Copy over the MD5 key from the original socket */
1460 key
= tcp_v4_md5_do_lookup(sk
, newinet
->inet_daddr
);
1463 * We're using one, so create a matching key
1464 * on the newsk structure. If we fail to get
1465 * memory, then we end up not copying the key
1468 char *newkey
= kmemdup(key
->key
, key
->keylen
, GFP_ATOMIC
);
1470 tcp_v4_md5_do_add(newsk
, newinet
->inet_daddr
,
1471 newkey
, key
->keylen
);
1472 sk_nocaps_add(newsk
, NETIF_F_GSO_MASK
);
1476 if (__inet_inherit_port(sk
, newsk
) < 0) {
1480 __inet_hash_nolisten(newsk
, NULL
);
1485 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1489 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1492 EXPORT_SYMBOL(tcp_v4_syn_recv_sock
);
1494 static struct sock
*tcp_v4_hnd_req(struct sock
*sk
, struct sk_buff
*skb
)
1496 struct tcphdr
*th
= tcp_hdr(skb
);
1497 const struct iphdr
*iph
= ip_hdr(skb
);
1499 struct request_sock
**prev
;
1500 /* Find possible connection requests. */
1501 struct request_sock
*req
= inet_csk_search_req(sk
, &prev
, th
->source
,
1502 iph
->saddr
, iph
->daddr
);
1504 return tcp_check_req(sk
, skb
, req
, prev
);
1506 nsk
= inet_lookup_established(sock_net(sk
), &tcp_hashinfo
, iph
->saddr
,
1507 th
->source
, iph
->daddr
, th
->dest
, inet_iif(skb
));
1510 if (nsk
->sk_state
!= TCP_TIME_WAIT
) {
1514 inet_twsk_put(inet_twsk(nsk
));
1518 #ifdef CONFIG_SYN_COOKIES
1520 sk
= cookie_v4_check(sk
, skb
, &(IPCB(skb
)->opt
));
1525 static __sum16
tcp_v4_checksum_init(struct sk_buff
*skb
)
1527 const struct iphdr
*iph
= ip_hdr(skb
);
1529 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
1530 if (!tcp_v4_check(skb
->len
, iph
->saddr
,
1531 iph
->daddr
, skb
->csum
)) {
1532 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1537 skb
->csum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
1538 skb
->len
, IPPROTO_TCP
, 0);
1540 if (skb
->len
<= 76) {
1541 return __skb_checksum_complete(skb
);
1547 /* The socket must have it's spinlock held when we get
1550 * We have a potential double-lock case here, so even when
1551 * doing backlog processing we use the BH locking scheme.
1552 * This is because we cannot sleep with the original spinlock
1555 int tcp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
)
1558 #ifdef CONFIG_TCP_MD5SIG
1560 * We really want to reject the packet as early as possible
1562 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1563 * o There is an MD5 option and we're not expecting one
1565 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1569 if (sk
->sk_state
== TCP_ESTABLISHED
) { /* Fast path */
1570 sock_rps_save_rxhash(sk
, skb
->rxhash
);
1571 if (tcp_rcv_established(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1578 if (skb
->len
< tcp_hdrlen(skb
) || tcp_checksum_complete(skb
))
1581 if (sk
->sk_state
== TCP_LISTEN
) {
1582 struct sock
*nsk
= tcp_v4_hnd_req(sk
, skb
);
1587 if (tcp_child_process(sk
, nsk
, skb
)) {
1594 sock_rps_save_rxhash(sk
, skb
->rxhash
);
1596 if (tcp_rcv_state_process(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1603 tcp_v4_send_reset(rsk
, skb
);
1606 /* Be careful here. If this function gets more complicated and
1607 * gcc suffers from register pressure on the x86, sk (in %ebx)
1608 * might be destroyed here. This current version compiles correctly,
1609 * but you have been warned.
1614 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_INERRS
);
1617 EXPORT_SYMBOL(tcp_v4_do_rcv
);
1623 int tcp_v4_rcv(struct sk_buff
*skb
)
1625 const struct iphdr
*iph
;
1629 struct net
*net
= dev_net(skb
->dev
);
1631 if (skb
->pkt_type
!= PACKET_HOST
)
1634 /* Count it even if it's bad */
1635 TCP_INC_STATS_BH(net
, TCP_MIB_INSEGS
);
1637 if (!pskb_may_pull(skb
, sizeof(struct tcphdr
)))
1642 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1644 if (!pskb_may_pull(skb
, th
->doff
* 4))
1647 /* An explanation is required here, I think.
1648 * Packet length and doff are validated by header prediction,
1649 * provided case of th->doff==0 is eliminated.
1650 * So, we defer the checks. */
1651 if (!skb_csum_unnecessary(skb
) && tcp_v4_checksum_init(skb
))
1656 TCP_SKB_CB(skb
)->seq
= ntohl(th
->seq
);
1657 TCP_SKB_CB(skb
)->end_seq
= (TCP_SKB_CB(skb
)->seq
+ th
->syn
+ th
->fin
+
1658 skb
->len
- th
->doff
* 4);
1659 TCP_SKB_CB(skb
)->ack_seq
= ntohl(th
->ack_seq
);
1660 TCP_SKB_CB(skb
)->when
= 0;
1661 TCP_SKB_CB(skb
)->flags
= iph
->tos
;
1662 TCP_SKB_CB(skb
)->sacked
= 0;
1664 sk
= __inet_lookup_skb(&tcp_hashinfo
, skb
, th
->source
, th
->dest
);
1669 if (sk
->sk_state
== TCP_TIME_WAIT
)
1672 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
1673 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
1674 goto discard_and_relse
;
1677 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
1678 goto discard_and_relse
;
1681 if (sk_filter(sk
, skb
))
1682 goto discard_and_relse
;
1686 bh_lock_sock_nested(sk
);
1688 if (!sock_owned_by_user(sk
)) {
1689 #ifdef CONFIG_NET_DMA
1690 struct tcp_sock
*tp
= tcp_sk(sk
);
1691 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1692 tp
->ucopy
.dma_chan
= dma_find_channel(DMA_MEMCPY
);
1693 if (tp
->ucopy
.dma_chan
)
1694 ret
= tcp_v4_do_rcv(sk
, skb
);
1698 if (!tcp_prequeue(sk
, skb
))
1699 ret
= tcp_v4_do_rcv(sk
, skb
);
1701 } else if (unlikely(sk_add_backlog(sk
, skb
))) {
1703 NET_INC_STATS_BH(net
, LINUX_MIB_TCPBACKLOGDROP
);
1704 goto discard_and_relse
;
1713 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
1716 if (skb
->len
< (th
->doff
<< 2) || tcp_checksum_complete(skb
)) {
1718 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
1720 tcp_v4_send_reset(NULL
, skb
);
1724 /* Discard frame. */
1733 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
)) {
1734 inet_twsk_put(inet_twsk(sk
));
1738 if (skb
->len
< (th
->doff
<< 2) || tcp_checksum_complete(skb
)) {
1739 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
1740 inet_twsk_put(inet_twsk(sk
));
1743 switch (tcp_timewait_state_process(inet_twsk(sk
), skb
, th
)) {
1745 struct sock
*sk2
= inet_lookup_listener(dev_net(skb
->dev
),
1747 iph
->daddr
, th
->dest
,
1750 inet_twsk_deschedule(inet_twsk(sk
), &tcp_death_row
);
1751 inet_twsk_put(inet_twsk(sk
));
1755 /* Fall through to ACK */
1758 tcp_v4_timewait_ack(sk
, skb
);
1762 case TCP_TW_SUCCESS
:;
1767 struct inet_peer
*tcp_v4_get_peer(struct sock
*sk
, bool *release_it
)
1769 struct rtable
*rt
= (struct rtable
*) __sk_dst_get(sk
);
1770 struct inet_sock
*inet
= inet_sk(sk
);
1771 struct inet_peer
*peer
;
1773 if (!rt
|| rt
->rt_dst
!= inet
->inet_daddr
) {
1774 peer
= inet_getpeer_v4(inet
->inet_daddr
, 1);
1778 rt_bind_peer(rt
, 1);
1780 *release_it
= false;
1785 EXPORT_SYMBOL(tcp_v4_get_peer
);
1787 void *tcp_v4_tw_get_peer(struct sock
*sk
)
1789 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
1791 return inet_getpeer_v4(tw
->tw_daddr
, 1);
1793 EXPORT_SYMBOL(tcp_v4_tw_get_peer
);
1795 static struct timewait_sock_ops tcp_timewait_sock_ops
= {
1796 .twsk_obj_size
= sizeof(struct tcp_timewait_sock
),
1797 .twsk_unique
= tcp_twsk_unique
,
1798 .twsk_destructor
= tcp_twsk_destructor
,
1799 .twsk_getpeer
= tcp_v4_tw_get_peer
,
1802 const struct inet_connection_sock_af_ops ipv4_specific
= {
1803 .queue_xmit
= ip_queue_xmit
,
1804 .send_check
= tcp_v4_send_check
,
1805 .rebuild_header
= inet_sk_rebuild_header
,
1806 .conn_request
= tcp_v4_conn_request
,
1807 .syn_recv_sock
= tcp_v4_syn_recv_sock
,
1808 .get_peer
= tcp_v4_get_peer
,
1809 .net_header_len
= sizeof(struct iphdr
),
1810 .setsockopt
= ip_setsockopt
,
1811 .getsockopt
= ip_getsockopt
,
1812 .addr2sockaddr
= inet_csk_addr2sockaddr
,
1813 .sockaddr_len
= sizeof(struct sockaddr_in
),
1814 .bind_conflict
= inet_csk_bind_conflict
,
1815 #ifdef CONFIG_COMPAT
1816 .compat_setsockopt
= compat_ip_setsockopt
,
1817 .compat_getsockopt
= compat_ip_getsockopt
,
1820 EXPORT_SYMBOL(ipv4_specific
);
1822 #ifdef CONFIG_TCP_MD5SIG
1823 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific
= {
1824 .md5_lookup
= tcp_v4_md5_lookup
,
1825 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1826 .md5_add
= tcp_v4_md5_add_func
,
1827 .md5_parse
= tcp_v4_parse_md5_keys
,
1831 /* NOTE: A lot of things set to zero explicitly by call to
1832 * sk_alloc() so need not be done here.
1834 static int tcp_v4_init_sock(struct sock
*sk
)
1836 struct inet_connection_sock
*icsk
= inet_csk(sk
);
1837 struct tcp_sock
*tp
= tcp_sk(sk
);
1839 skb_queue_head_init(&tp
->out_of_order_queue
);
1840 tcp_init_xmit_timers(sk
);
1841 tcp_prequeue_init(tp
);
1843 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
1844 tp
->mdev
= TCP_TIMEOUT_INIT
;
1846 /* So many TCP implementations out there (incorrectly) count the
1847 * initial SYN frame in their delayed-ACK and congestion control
1848 * algorithms that we must have the following bandaid to talk
1849 * efficiently to them. -DaveM
1853 /* See draft-stevens-tcpca-spec-01 for discussion of the
1854 * initialization of these values.
1856 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
1857 tp
->snd_cwnd_clamp
= ~0;
1858 tp
->mss_cache
= TCP_MSS_DEFAULT
;
1860 tp
->reordering
= sysctl_tcp_reordering
;
1861 icsk
->icsk_ca_ops
= &tcp_init_congestion_ops
;
1863 sk
->sk_state
= TCP_CLOSE
;
1865 sk
->sk_write_space
= sk_stream_write_space
;
1866 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
1868 icsk
->icsk_af_ops
= &ipv4_specific
;
1869 icsk
->icsk_sync_mss
= tcp_sync_mss
;
1870 #ifdef CONFIG_TCP_MD5SIG
1871 tp
->af_specific
= &tcp_sock_ipv4_specific
;
1874 /* TCP Cookie Transactions */
1875 if (sysctl_tcp_cookie_size
> 0) {
1876 /* Default, cookies without s_data_payload. */
1878 kzalloc(sizeof(*tp
->cookie_values
),
1880 if (tp
->cookie_values
!= NULL
)
1881 kref_init(&tp
->cookie_values
->kref
);
1883 /* Presumed zeroed, in order of appearance:
1884 * cookie_in_always, cookie_out_never,
1885 * s_data_constant, s_data_in, s_data_out
1887 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
1888 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
1891 percpu_counter_inc(&tcp_sockets_allocated
);
1897 void tcp_v4_destroy_sock(struct sock
*sk
)
1899 struct tcp_sock
*tp
= tcp_sk(sk
);
1901 tcp_clear_xmit_timers(sk
);
1903 tcp_cleanup_congestion_control(sk
);
1905 /* Cleanup up the write buffer. */
1906 tcp_write_queue_purge(sk
);
1908 /* Cleans up our, hopefully empty, out_of_order_queue. */
1909 __skb_queue_purge(&tp
->out_of_order_queue
);
1911 #ifdef CONFIG_TCP_MD5SIG
1912 /* Clean up the MD5 key list, if any */
1913 if (tp
->md5sig_info
) {
1914 tcp_v4_clear_md5_list(sk
);
1915 kfree(tp
->md5sig_info
);
1916 tp
->md5sig_info
= NULL
;
1920 #ifdef CONFIG_NET_DMA
1921 /* Cleans up our sk_async_wait_queue */
1922 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1925 /* Clean prequeue, it must be empty really */
1926 __skb_queue_purge(&tp
->ucopy
.prequeue
);
1928 /* Clean up a referenced TCP bind bucket. */
1929 if (inet_csk(sk
)->icsk_bind_hash
)
1933 * If sendmsg cached page exists, toss it.
1935 if (sk
->sk_sndmsg_page
) {
1936 __free_page(sk
->sk_sndmsg_page
);
1937 sk
->sk_sndmsg_page
= NULL
;
1940 /* TCP Cookie Transactions */
1941 if (tp
->cookie_values
!= NULL
) {
1942 kref_put(&tp
->cookie_values
->kref
,
1943 tcp_cookie_values_release
);
1944 tp
->cookie_values
= NULL
;
1947 percpu_counter_dec(&tcp_sockets_allocated
);
1949 EXPORT_SYMBOL(tcp_v4_destroy_sock
);
1951 #ifdef CONFIG_PROC_FS
1952 /* Proc filesystem TCP sock list dumping. */
1954 static inline struct inet_timewait_sock
*tw_head(struct hlist_nulls_head
*head
)
1956 return hlist_nulls_empty(head
) ? NULL
:
1957 list_entry(head
->first
, struct inet_timewait_sock
, tw_node
);
1960 static inline struct inet_timewait_sock
*tw_next(struct inet_timewait_sock
*tw
)
1962 return !is_a_nulls(tw
->tw_node
.next
) ?
1963 hlist_nulls_entry(tw
->tw_node
.next
, typeof(*tw
), tw_node
) : NULL
;
1967 * Get next listener socket follow cur. If cur is NULL, get first socket
1968 * starting from bucket given in st->bucket; when st->bucket is zero the
1969 * very first socket in the hash table is returned.
1971 static void *listening_get_next(struct seq_file
*seq
, void *cur
)
1973 struct inet_connection_sock
*icsk
;
1974 struct hlist_nulls_node
*node
;
1975 struct sock
*sk
= cur
;
1976 struct inet_listen_hashbucket
*ilb
;
1977 struct tcp_iter_state
*st
= seq
->private;
1978 struct net
*net
= seq_file_net(seq
);
1981 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1982 spin_lock_bh(&ilb
->lock
);
1983 sk
= sk_nulls_head(&ilb
->head
);
1987 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
1991 if (st
->state
== TCP_SEQ_STATE_OPENREQ
) {
1992 struct request_sock
*req
= cur
;
1994 icsk
= inet_csk(st
->syn_wait_sk
);
1998 if (req
->rsk_ops
->family
== st
->family
) {
2004 if (++st
->sbucket
>= icsk
->icsk_accept_queue
.listen_opt
->nr_table_entries
)
2007 req
= icsk
->icsk_accept_queue
.listen_opt
->syn_table
[st
->sbucket
];
2009 sk
= sk_nulls_next(st
->syn_wait_sk
);
2010 st
->state
= TCP_SEQ_STATE_LISTENING
;
2011 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2013 icsk
= inet_csk(sk
);
2014 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2015 if (reqsk_queue_len(&icsk
->icsk_accept_queue
))
2017 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2018 sk
= sk_nulls_next(sk
);
2021 sk_nulls_for_each_from(sk
, node
) {
2022 if (!net_eq(sock_net(sk
), net
))
2024 if (sk
->sk_family
== st
->family
) {
2028 icsk
= inet_csk(sk
);
2029 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2030 if (reqsk_queue_len(&icsk
->icsk_accept_queue
)) {
2032 st
->uid
= sock_i_uid(sk
);
2033 st
->syn_wait_sk
= sk
;
2034 st
->state
= TCP_SEQ_STATE_OPENREQ
;
2038 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2040 spin_unlock_bh(&ilb
->lock
);
2042 if (++st
->bucket
< INET_LHTABLE_SIZE
) {
2043 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2044 spin_lock_bh(&ilb
->lock
);
2045 sk
= sk_nulls_head(&ilb
->head
);
2053 static void *listening_get_idx(struct seq_file
*seq
, loff_t
*pos
)
2055 struct tcp_iter_state
*st
= seq
->private;
2060 rc
= listening_get_next(seq
, NULL
);
2062 while (rc
&& *pos
) {
2063 rc
= listening_get_next(seq
, rc
);
2069 static inline int empty_bucket(struct tcp_iter_state
*st
)
2071 return hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].chain
) &&
2072 hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2076 * Get first established socket starting from bucket given in st->bucket.
2077 * If st->bucket is zero, the very first socket in the hash is returned.
2079 static void *established_get_first(struct seq_file
*seq
)
2081 struct tcp_iter_state
*st
= seq
->private;
2082 struct net
*net
= seq_file_net(seq
);
2086 for (; st
->bucket
<= tcp_hashinfo
.ehash_mask
; ++st
->bucket
) {
2088 struct hlist_nulls_node
*node
;
2089 struct inet_timewait_sock
*tw
;
2090 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
);
2092 /* Lockless fast path for the common case of empty buckets */
2093 if (empty_bucket(st
))
2097 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[st
->bucket
].chain
) {
2098 if (sk
->sk_family
!= st
->family
||
2099 !net_eq(sock_net(sk
), net
)) {
2105 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2106 inet_twsk_for_each(tw
, node
,
2107 &tcp_hashinfo
.ehash
[st
->bucket
].twchain
) {
2108 if (tw
->tw_family
!= st
->family
||
2109 !net_eq(twsk_net(tw
), net
)) {
2115 spin_unlock_bh(lock
);
2116 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2122 static void *established_get_next(struct seq_file
*seq
, void *cur
)
2124 struct sock
*sk
= cur
;
2125 struct inet_timewait_sock
*tw
;
2126 struct hlist_nulls_node
*node
;
2127 struct tcp_iter_state
*st
= seq
->private;
2128 struct net
*net
= seq_file_net(seq
);
2133 if (st
->state
== TCP_SEQ_STATE_TIME_WAIT
) {
2137 while (tw
&& (tw
->tw_family
!= st
->family
|| !net_eq(twsk_net(tw
), net
))) {
2144 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2145 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2147 /* Look for next non empty bucket */
2149 while (++st
->bucket
<= tcp_hashinfo
.ehash_mask
&&
2152 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2155 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2156 sk
= sk_nulls_head(&tcp_hashinfo
.ehash
[st
->bucket
].chain
);
2158 sk
= sk_nulls_next(sk
);
2160 sk_nulls_for_each_from(sk
, node
) {
2161 if (sk
->sk_family
== st
->family
&& net_eq(sock_net(sk
), net
))
2165 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2166 tw
= tw_head(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2174 static void *established_get_idx(struct seq_file
*seq
, loff_t pos
)
2176 struct tcp_iter_state
*st
= seq
->private;
2180 rc
= established_get_first(seq
);
2183 rc
= established_get_next(seq
, rc
);
2189 static void *tcp_get_idx(struct seq_file
*seq
, loff_t pos
)
2192 struct tcp_iter_state
*st
= seq
->private;
2194 st
->state
= TCP_SEQ_STATE_LISTENING
;
2195 rc
= listening_get_idx(seq
, &pos
);
2198 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2199 rc
= established_get_idx(seq
, pos
);
2205 static void *tcp_seek_last_pos(struct seq_file
*seq
)
2207 struct tcp_iter_state
*st
= seq
->private;
2208 int offset
= st
->offset
;
2209 int orig_num
= st
->num
;
2212 switch (st
->state
) {
2213 case TCP_SEQ_STATE_OPENREQ
:
2214 case TCP_SEQ_STATE_LISTENING
:
2215 if (st
->bucket
>= INET_LHTABLE_SIZE
)
2217 st
->state
= TCP_SEQ_STATE_LISTENING
;
2218 rc
= listening_get_next(seq
, NULL
);
2219 while (offset
-- && rc
)
2220 rc
= listening_get_next(seq
, rc
);
2225 case TCP_SEQ_STATE_ESTABLISHED
:
2226 case TCP_SEQ_STATE_TIME_WAIT
:
2227 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2228 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2230 rc
= established_get_first(seq
);
2231 while (offset
-- && rc
)
2232 rc
= established_get_next(seq
, rc
);
2240 static void *tcp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2242 struct tcp_iter_state
*st
= seq
->private;
2245 if (*pos
&& *pos
== st
->last_pos
) {
2246 rc
= tcp_seek_last_pos(seq
);
2251 st
->state
= TCP_SEQ_STATE_LISTENING
;
2255 rc
= *pos
? tcp_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2258 st
->last_pos
= *pos
;
2262 static void *tcp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2264 struct tcp_iter_state
*st
= seq
->private;
2267 if (v
== SEQ_START_TOKEN
) {
2268 rc
= tcp_get_idx(seq
, 0);
2272 switch (st
->state
) {
2273 case TCP_SEQ_STATE_OPENREQ
:
2274 case TCP_SEQ_STATE_LISTENING
:
2275 rc
= listening_get_next(seq
, v
);
2277 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2280 rc
= established_get_first(seq
);
2283 case TCP_SEQ_STATE_ESTABLISHED
:
2284 case TCP_SEQ_STATE_TIME_WAIT
:
2285 rc
= established_get_next(seq
, v
);
2290 st
->last_pos
= *pos
;
2294 static void tcp_seq_stop(struct seq_file
*seq
, void *v
)
2296 struct tcp_iter_state
*st
= seq
->private;
2298 switch (st
->state
) {
2299 case TCP_SEQ_STATE_OPENREQ
:
2301 struct inet_connection_sock
*icsk
= inet_csk(st
->syn_wait_sk
);
2302 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2304 case TCP_SEQ_STATE_LISTENING
:
2305 if (v
!= SEQ_START_TOKEN
)
2306 spin_unlock_bh(&tcp_hashinfo
.listening_hash
[st
->bucket
].lock
);
2308 case TCP_SEQ_STATE_TIME_WAIT
:
2309 case TCP_SEQ_STATE_ESTABLISHED
:
2311 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2316 static int tcp_seq_open(struct inode
*inode
, struct file
*file
)
2318 struct tcp_seq_afinfo
*afinfo
= PDE(inode
)->data
;
2319 struct tcp_iter_state
*s
;
2322 err
= seq_open_net(inode
, file
, &afinfo
->seq_ops
,
2323 sizeof(struct tcp_iter_state
));
2327 s
= ((struct seq_file
*)file
->private_data
)->private;
2328 s
->family
= afinfo
->family
;
2333 int tcp_proc_register(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2336 struct proc_dir_entry
*p
;
2338 afinfo
->seq_fops
.open
= tcp_seq_open
;
2339 afinfo
->seq_fops
.read
= seq_read
;
2340 afinfo
->seq_fops
.llseek
= seq_lseek
;
2341 afinfo
->seq_fops
.release
= seq_release_net
;
2343 afinfo
->seq_ops
.start
= tcp_seq_start
;
2344 afinfo
->seq_ops
.next
= tcp_seq_next
;
2345 afinfo
->seq_ops
.stop
= tcp_seq_stop
;
2347 p
= proc_create_data(afinfo
->name
, S_IRUGO
, net
->proc_net
,
2348 &afinfo
->seq_fops
, afinfo
);
2353 EXPORT_SYMBOL(tcp_proc_register
);
2355 void tcp_proc_unregister(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2357 proc_net_remove(net
, afinfo
->name
);
2359 EXPORT_SYMBOL(tcp_proc_unregister
);
2361 static void get_openreq4(struct sock
*sk
, struct request_sock
*req
,
2362 struct seq_file
*f
, int i
, int uid
, int *len
)
2364 const struct inet_request_sock
*ireq
= inet_rsk(req
);
2365 int ttd
= req
->expires
- jiffies
;
2367 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2368 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
2371 ntohs(inet_sk(sk
)->inet_sport
),
2373 ntohs(ireq
->rmt_port
),
2375 0, 0, /* could print option size, but that is af dependent. */
2376 1, /* timers active (only the expire timer) */
2377 jiffies_to_clock_t(ttd
),
2380 0, /* non standard timer */
2381 0, /* open_requests have no inode */
2382 atomic_read(&sk
->sk_refcnt
),
2387 static void get_tcp4_sock(struct sock
*sk
, struct seq_file
*f
, int i
, int *len
)
2390 unsigned long timer_expires
;
2391 struct tcp_sock
*tp
= tcp_sk(sk
);
2392 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2393 struct inet_sock
*inet
= inet_sk(sk
);
2394 __be32 dest
= inet
->inet_daddr
;
2395 __be32 src
= inet
->inet_rcv_saddr
;
2396 __u16 destp
= ntohs(inet
->inet_dport
);
2397 __u16 srcp
= ntohs(inet
->inet_sport
);
2400 if (icsk
->icsk_pending
== ICSK_TIME_RETRANS
) {
2402 timer_expires
= icsk
->icsk_timeout
;
2403 } else if (icsk
->icsk_pending
== ICSK_TIME_PROBE0
) {
2405 timer_expires
= icsk
->icsk_timeout
;
2406 } else if (timer_pending(&sk
->sk_timer
)) {
2408 timer_expires
= sk
->sk_timer
.expires
;
2411 timer_expires
= jiffies
;
2414 if (sk
->sk_state
== TCP_LISTEN
)
2415 rx_queue
= sk
->sk_ack_backlog
;
2418 * because we dont lock socket, we might find a transient negative value
2420 rx_queue
= max_t(int, tp
->rcv_nxt
- tp
->copied_seq
, 0);
2422 seq_printf(f
, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2423 "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
2424 i
, src
, srcp
, dest
, destp
, sk
->sk_state
,
2425 tp
->write_seq
- tp
->snd_una
,
2428 jiffies_to_clock_t(timer_expires
- jiffies
),
2429 icsk
->icsk_retransmits
,
2431 icsk
->icsk_probes_out
,
2433 atomic_read(&sk
->sk_refcnt
), sk
,
2434 jiffies_to_clock_t(icsk
->icsk_rto
),
2435 jiffies_to_clock_t(icsk
->icsk_ack
.ato
),
2436 (icsk
->icsk_ack
.quick
<< 1) | icsk
->icsk_ack
.pingpong
,
2438 tcp_in_initial_slowstart(tp
) ? -1 : tp
->snd_ssthresh
,
2442 static void get_timewait4_sock(struct inet_timewait_sock
*tw
,
2443 struct seq_file
*f
, int i
, int *len
)
2447 int ttd
= tw
->tw_ttd
- jiffies
;
2452 dest
= tw
->tw_daddr
;
2453 src
= tw
->tw_rcv_saddr
;
2454 destp
= ntohs(tw
->tw_dport
);
2455 srcp
= ntohs(tw
->tw_sport
);
2457 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2458 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
2459 i
, src
, srcp
, dest
, destp
, tw
->tw_substate
, 0, 0,
2460 3, jiffies_to_clock_t(ttd
), 0, 0, 0, 0,
2461 atomic_read(&tw
->tw_refcnt
), tw
, len
);
2466 static int tcp4_seq_show(struct seq_file
*seq
, void *v
)
2468 struct tcp_iter_state
*st
;
2471 if (v
== SEQ_START_TOKEN
) {
2472 seq_printf(seq
, "%-*s\n", TMPSZ
- 1,
2473 " sl local_address rem_address st tx_queue "
2474 "rx_queue tr tm->when retrnsmt uid timeout "
2480 switch (st
->state
) {
2481 case TCP_SEQ_STATE_LISTENING
:
2482 case TCP_SEQ_STATE_ESTABLISHED
:
2483 get_tcp4_sock(v
, seq
, st
->num
, &len
);
2485 case TCP_SEQ_STATE_OPENREQ
:
2486 get_openreq4(st
->syn_wait_sk
, v
, seq
, st
->num
, st
->uid
, &len
);
2488 case TCP_SEQ_STATE_TIME_WAIT
:
2489 get_timewait4_sock(v
, seq
, st
->num
, &len
);
2492 seq_printf(seq
, "%*s\n", TMPSZ
- 1 - len
, "");
2497 static struct tcp_seq_afinfo tcp4_seq_afinfo
= {
2501 .owner
= THIS_MODULE
,
2504 .show
= tcp4_seq_show
,
2508 static int __net_init
tcp4_proc_init_net(struct net
*net
)
2510 return tcp_proc_register(net
, &tcp4_seq_afinfo
);
2513 static void __net_exit
tcp4_proc_exit_net(struct net
*net
)
2515 tcp_proc_unregister(net
, &tcp4_seq_afinfo
);
2518 static struct pernet_operations tcp4_net_ops
= {
2519 .init
= tcp4_proc_init_net
,
2520 .exit
= tcp4_proc_exit_net
,
2523 int __init
tcp4_proc_init(void)
2525 return register_pernet_subsys(&tcp4_net_ops
);
2528 void tcp4_proc_exit(void)
2530 unregister_pernet_subsys(&tcp4_net_ops
);
2532 #endif /* CONFIG_PROC_FS */
2534 struct sk_buff
**tcp4_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
2536 const struct iphdr
*iph
= skb_gro_network_header(skb
);
2538 switch (skb
->ip_summed
) {
2539 case CHECKSUM_COMPLETE
:
2540 if (!tcp_v4_check(skb_gro_len(skb
), iph
->saddr
, iph
->daddr
,
2542 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2548 NAPI_GRO_CB(skb
)->flush
= 1;
2552 return tcp_gro_receive(head
, skb
);
2555 int tcp4_gro_complete(struct sk_buff
*skb
)
2557 const struct iphdr
*iph
= ip_hdr(skb
);
2558 struct tcphdr
*th
= tcp_hdr(skb
);
2560 th
->check
= ~tcp_v4_check(skb
->len
- skb_transport_offset(skb
),
2561 iph
->saddr
, iph
->daddr
, 0);
2562 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
2564 return tcp_gro_complete(skb
);
2567 struct proto tcp_prot
= {
2569 .owner
= THIS_MODULE
,
2571 .connect
= tcp_v4_connect
,
2572 .disconnect
= tcp_disconnect
,
2573 .accept
= inet_csk_accept
,
2575 .init
= tcp_v4_init_sock
,
2576 .destroy
= tcp_v4_destroy_sock
,
2577 .shutdown
= tcp_shutdown
,
2578 .setsockopt
= tcp_setsockopt
,
2579 .getsockopt
= tcp_getsockopt
,
2580 .recvmsg
= tcp_recvmsg
,
2581 .sendmsg
= tcp_sendmsg
,
2582 .sendpage
= tcp_sendpage
,
2583 .backlog_rcv
= tcp_v4_do_rcv
,
2585 .unhash
= inet_unhash
,
2586 .get_port
= inet_csk_get_port
,
2587 .enter_memory_pressure
= tcp_enter_memory_pressure
,
2588 .sockets_allocated
= &tcp_sockets_allocated
,
2589 .orphan_count
= &tcp_orphan_count
,
2590 .memory_allocated
= &tcp_memory_allocated
,
2591 .memory_pressure
= &tcp_memory_pressure
,
2592 .sysctl_mem
= sysctl_tcp_mem
,
2593 .sysctl_wmem
= sysctl_tcp_wmem
,
2594 .sysctl_rmem
= sysctl_tcp_rmem
,
2595 .max_header
= MAX_TCP_HEADER
,
2596 .obj_size
= sizeof(struct tcp_sock
),
2597 .slab_flags
= SLAB_DESTROY_BY_RCU
,
2598 .twsk_prot
= &tcp_timewait_sock_ops
,
2599 .rsk_prot
= &tcp_request_sock_ops
,
2600 .h
.hashinfo
= &tcp_hashinfo
,
2601 .no_autobind
= true,
2602 #ifdef CONFIG_COMPAT
2603 .compat_setsockopt
= compat_tcp_setsockopt
,
2604 .compat_getsockopt
= compat_tcp_getsockopt
,
2607 EXPORT_SYMBOL(tcp_prot
);
2610 static int __net_init
tcp_sk_init(struct net
*net
)
2612 return inet_ctl_sock_create(&net
->ipv4
.tcp_sock
,
2613 PF_INET
, SOCK_RAW
, IPPROTO_TCP
, net
);
2616 static void __net_exit
tcp_sk_exit(struct net
*net
)
2618 inet_ctl_sock_destroy(net
->ipv4
.tcp_sock
);
2621 static void __net_exit
tcp_sk_exit_batch(struct list_head
*net_exit_list
)
2623 inet_twsk_purge(&tcp_hashinfo
, &tcp_death_row
, AF_INET
);
2626 static struct pernet_operations __net_initdata tcp_sk_ops
= {
2627 .init
= tcp_sk_init
,
2628 .exit
= tcp_sk_exit
,
2629 .exit_batch
= tcp_sk_exit_batch
,
2632 void __init
tcp_v4_init(void)
2634 inet_hashinfo_init(&tcp_hashinfo
);
2635 if (register_pernet_subsys(&tcp_sk_ops
))
2636 panic("Failed to create the TCP control socket.\n");