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(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
);
236 printk(KERN_INFO
"[socket_conn]IPV4 socket[%lu] sport:%u \n", SOCK_INODE(sk
->sk_socket
)->i_ino
, ntohs(inet
->inet_sport
));
237 if (!tp
->write_seq
&& likely(!tp
->repair
))
238 tp
->write_seq
= secure_tcp_sequence_number(inet
->inet_saddr
,
243 inet
->inet_id
= tp
->write_seq
^ jiffies
;
245 err
= tcp_connect(sk
);
255 * This unhashes the socket and releases the local port,
258 tcp_set_state(sk
, TCP_CLOSE
);
260 sk
->sk_route_caps
= 0;
261 inet
->inet_dport
= 0;
264 EXPORT_SYMBOL(tcp_v4_connect
);
267 * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191.
268 * It can be called through tcp_release_cb() if socket was owned by user
269 * at the time tcp_v4_err() was called to handle ICMP message.
271 void tcp_v4_mtu_reduced(struct sock
*sk
)
273 struct dst_entry
*dst
;
274 struct inet_sock
*inet
= inet_sk(sk
);
275 u32 mtu
= tcp_sk(sk
)->mtu_info
;
277 dst
= inet_csk_update_pmtu(sk
, mtu
);
281 /* Something is about to be wrong... Remember soft error
282 * for the case, if this connection will not able to recover.
284 if (mtu
< dst_mtu(dst
) && ip_dont_fragment(sk
, dst
))
285 sk
->sk_err_soft
= EMSGSIZE
;
289 if (inet
->pmtudisc
!= IP_PMTUDISC_DONT
&&
290 inet_csk(sk
)->icsk_pmtu_cookie
> mtu
) {
291 tcp_sync_mss(sk
, mtu
);
293 /* Resend the TCP packet because it's
294 * clear that the old packet has been
295 * dropped. This is the new "fast" path mtu
298 tcp_simple_retransmit(sk
);
299 } /* else let the usual retransmit timer handle it */
301 EXPORT_SYMBOL(tcp_v4_mtu_reduced
);
303 static void do_redirect(struct sk_buff
*skb
, struct sock
*sk
)
305 struct dst_entry
*dst
= __sk_dst_check(sk
, 0);
308 dst
->ops
->redirect(dst
, sk
, skb
);
312 * This routine is called by the ICMP module when it gets some
313 * sort of error condition. If err < 0 then the socket should
314 * be closed and the error returned to the user. If err > 0
315 * it's just the icmp type << 8 | icmp code. After adjustment
316 * header points to the first 8 bytes of the tcp header. We need
317 * to find the appropriate port.
319 * The locking strategy used here is very "optimistic". When
320 * someone else accesses the socket the ICMP is just dropped
321 * and for some paths there is no check at all.
322 * A more general error queue to queue errors for later handling
323 * is probably better.
327 void tcp_v4_err(struct sk_buff
*icmp_skb
, u32 info
)
329 const struct iphdr
*iph
= (const struct iphdr
*)icmp_skb
->data
;
330 struct tcphdr
*th
= (struct tcphdr
*)(icmp_skb
->data
+ (iph
->ihl
<< 2));
331 struct inet_connection_sock
*icsk
;
333 struct inet_sock
*inet
;
334 const int type
= icmp_hdr(icmp_skb
)->type
;
335 const int code
= icmp_hdr(icmp_skb
)->code
;
338 struct request_sock
*req
;
342 struct net
*net
= dev_net(icmp_skb
->dev
);
344 if (icmp_skb
->len
< (iph
->ihl
<< 2) + 8) {
345 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
349 sk
= inet_lookup(net
, &tcp_hashinfo
, iph
->daddr
, th
->dest
,
350 iph
->saddr
, th
->source
, inet_iif(icmp_skb
));
352 ICMP_INC_STATS_BH(net
, ICMP_MIB_INERRORS
);
355 if (sk
->sk_state
== TCP_TIME_WAIT
) {
356 inet_twsk_put(inet_twsk(sk
));
361 /* If too many ICMPs get dropped on busy
362 * servers this needs to be solved differently.
363 * We do take care of PMTU discovery (RFC1191) special case :
364 * we can receive locally generated ICMP messages while socket is held.
366 if (sock_owned_by_user(sk
)) {
367 if (!(type
== ICMP_DEST_UNREACH
&& code
== ICMP_FRAG_NEEDED
))
368 NET_INC_STATS_BH(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
370 if (sk
->sk_state
== TCP_CLOSE
)
373 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
374 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
380 req
= tp
->fastopen_rsk
;
381 seq
= ntohl(th
->seq
);
382 if (sk
->sk_state
!= TCP_LISTEN
&&
383 !between(seq
, tp
->snd_una
, tp
->snd_nxt
) &&
384 (req
== NULL
|| seq
!= tcp_rsk(req
)->snt_isn
)) {
385 /* For a Fast Open socket, allow seq to be snt_isn. */
386 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
392 if (!sock_owned_by_user(sk
))
393 do_redirect(icmp_skb
, sk
);
395 case ICMP_SOURCE_QUENCH
:
396 /* Just silently ignore these. */
398 case ICMP_PARAMETERPROB
:
401 case ICMP_DEST_UNREACH
:
402 if (code
> NR_ICMP_UNREACH
)
405 if (code
== ICMP_FRAG_NEEDED
) { /* PMTU discovery (RFC1191) */
406 /* We are not interested in TCP_LISTEN and open_requests
407 * (SYN-ACKs send out by Linux are always <576bytes so
408 * they should go through unfragmented).
410 if (sk
->sk_state
== TCP_LISTEN
)
414 if (!sock_owned_by_user(sk
)) {
415 tcp_v4_mtu_reduced(sk
);
417 if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED
, &tp
->tsq_flags
))
423 err
= icmp_err_convert
[code
].errno
;
424 /* check if icmp_skb allows revert of backoff
425 * (see draft-zimmermann-tcp-lcd) */
426 if (code
!= ICMP_NET_UNREACH
&& code
!= ICMP_HOST_UNREACH
)
428 if (seq
!= tp
->snd_una
|| !icsk
->icsk_retransmits
||
432 /* XXX (TFO) - revisit the following logic for TFO */
434 if (sock_owned_by_user(sk
))
437 icsk
->icsk_backoff
--;
438 inet_csk(sk
)->icsk_rto
= (tp
->srtt
? __tcp_set_rto(tp
) :
439 TCP_TIMEOUT_INIT
) << icsk
->icsk_backoff
;
442 skb
= tcp_write_queue_head(sk
);
445 remaining
= icsk
->icsk_rto
- min(icsk
->icsk_rto
,
446 tcp_time_stamp
- TCP_SKB_CB(skb
)->when
);
449 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
450 remaining
, sysctl_tcp_rto_max
);
452 /* RTO revert clocked out retransmission.
453 * Will retransmit now */
454 tcp_retransmit_timer(sk
);
458 case ICMP_TIME_EXCEEDED
:
465 /* XXX (TFO) - if it's a TFO socket and has been accepted, rather
466 * than following the TCP_SYN_RECV case and closing the socket,
467 * we ignore the ICMP error and keep trying like a fully established
468 * socket. Is this the right thing to do?
470 if (req
&& req
->sk
== NULL
)
473 switch (sk
->sk_state
) {
474 struct request_sock
*req
, **prev
;
476 if (sock_owned_by_user(sk
))
479 req
= inet_csk_search_req(sk
, &prev
, th
->dest
,
480 iph
->daddr
, iph
->saddr
);
484 /* ICMPs are not backlogged, hence we cannot get
485 an established socket here.
489 if (seq
!= tcp_rsk(req
)->snt_isn
) {
490 NET_INC_STATS_BH(net
, LINUX_MIB_OUTOFWINDOWICMPS
);
495 * Still in SYN_RECV, just remove it silently.
496 * There is no good way to pass the error to the newly
497 * created socket, and POSIX does not want network
498 * errors returned from accept().
500 inet_csk_reqsk_queue_drop(sk
, req
, prev
);
501 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
505 case TCP_SYN_RECV
: /* Cannot happen.
506 It can f.e. if SYNs crossed,
509 if (!sock_owned_by_user(sk
)) {
512 sk
->sk_error_report(sk
);
516 sk
->sk_err_soft
= err
;
521 /* If we've already connected we will keep trying
522 * until we time out, or the user gives up.
524 * rfc1122 4.2.3.9 allows to consider as hard errors
525 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
526 * but it is obsoleted by pmtu discovery).
528 * Note, that in modern internet, where routing is unreliable
529 * and in each dark corner broken firewalls sit, sending random
530 * errors ordered by their masters even this two messages finally lose
531 * their original sense (even Linux sends invalid PORT_UNREACHs)
533 * Now we are in compliance with RFCs.
538 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
540 sk
->sk_error_report(sk
);
541 } else { /* Only an error on timeout */
542 sk
->sk_err_soft
= err
;
550 static void __tcp_v4_send_check(struct sk_buff
*skb
,
551 __be32 saddr
, __be32 daddr
)
553 struct tcphdr
*th
= tcp_hdr(skb
);
555 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
556 th
->check
= ~tcp_v4_check(skb
->len
, saddr
, daddr
, 0);
557 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
558 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
560 th
->check
= tcp_v4_check(skb
->len
, saddr
, daddr
,
567 /* This routine computes an IPv4 TCP checksum. */
568 void tcp_v4_send_check(struct sock
*sk
, struct sk_buff
*skb
)
570 const struct inet_sock
*inet
= inet_sk(sk
);
572 __tcp_v4_send_check(skb
, inet
->inet_saddr
, inet
->inet_daddr
);
574 EXPORT_SYMBOL(tcp_v4_send_check
);
576 int tcp_v4_gso_send_check(struct sk_buff
*skb
)
578 const struct iphdr
*iph
;
581 if (!pskb_may_pull(skb
, sizeof(*th
)))
588 skb
->ip_summed
= CHECKSUM_PARTIAL
;
589 __tcp_v4_send_check(skb
, iph
->saddr
, iph
->daddr
);
594 * This routine will send an RST to the other tcp.
596 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
598 * Answer: if a packet caused RST, it is not for a socket
599 * existing in our system, if it is matched to a socket,
600 * it is just duplicate segment or bug in other side's TCP.
601 * So that we build reply only basing on parameters
602 * arrived with segment.
603 * Exception: precedence violation. We do not implement it in any case.
606 static void tcp_v4_send_reset(struct sock
*sk
, struct sk_buff
*skb
)
608 const struct tcphdr
*th
= tcp_hdr(skb
);
611 #ifdef CONFIG_TCP_MD5SIG
612 __be32 opt
[(TCPOLEN_MD5SIG_ALIGNED
>> 2)];
615 struct ip_reply_arg arg
;
616 #ifdef CONFIG_TCP_MD5SIG
617 struct tcp_md5sig_key
*key
;
618 const __u8
*hash_location
= NULL
;
619 unsigned char newhash
[16];
621 struct sock
*sk1
= NULL
;
625 /* Never send a reset in response to a reset. */
629 if (skb_rtable(skb
)->rt_type
!= RTN_LOCAL
)
632 /* Swap the send and the receive. */
633 memset(&rep
, 0, sizeof(rep
));
634 rep
.th
.dest
= th
->source
;
635 rep
.th
.source
= th
->dest
;
636 rep
.th
.doff
= sizeof(struct tcphdr
) / 4;
640 rep
.th
.seq
= th
->ack_seq
;
643 rep
.th
.ack_seq
= htonl(ntohl(th
->seq
) + th
->syn
+ th
->fin
+
644 skb
->len
- (th
->doff
<< 2));
647 memset(&arg
, 0, sizeof(arg
));
648 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
649 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
651 #ifdef CONFIG_TCP_MD5SIG
652 hash_location
= tcp_parse_md5sig_option(th
);
653 if (!sk
&& hash_location
) {
655 * active side is lost. Try to find listening socket through
656 * source port, and then find md5 key through listening socket.
657 * we are not loose security here:
658 * Incoming packet is checked with md5 hash with finding key,
659 * no RST generated if md5 hash doesn't match.
661 sk1
= __inet_lookup_listener(dev_net(skb_dst(skb
)->dev
),
662 &tcp_hashinfo
, ip_hdr(skb
)->saddr
,
663 th
->source
, ip_hdr(skb
)->daddr
,
664 ntohs(th
->source
), inet_iif(skb
));
665 /* don't send rst if it can't find key */
669 key
= tcp_md5_do_lookup(sk1
, (union tcp_md5_addr
*)
670 &ip_hdr(skb
)->saddr
, AF_INET
);
674 genhash
= tcp_v4_md5_hash_skb(newhash
, key
, NULL
, NULL
, skb
);
675 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0)
678 key
= sk
? tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)
684 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) |
686 (TCPOPT_MD5SIG
<< 8) |
688 /* Update length and the length the header thinks exists */
689 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
690 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
692 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[1],
693 key
, ip_hdr(skb
)->saddr
,
694 ip_hdr(skb
)->daddr
, &rep
.th
);
697 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
698 ip_hdr(skb
)->saddr
, /* XXX */
699 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
700 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
701 arg
.flags
= (sk
&& inet_sk(sk
)->transparent
) ? IP_REPLY_ARG_NOSRCCHECK
: 0;
702 /* When socket is gone, all binding information is lost.
703 * routing might fail in this case. No choice here, if we choose to force
704 * input interface, we will misroute in case of asymmetric route.
707 arg
.bound_dev_if
= sk
->sk_bound_dev_if
;
709 net
= dev_net(skb_dst(skb
)->dev
);
710 arg
.tos
= ip_hdr(skb
)->tos
;
711 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
712 skb
, ip_hdr(skb
)->saddr
,
713 ip_hdr(skb
)->daddr
, &arg
, arg
.iov
[0].iov_len
);
715 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
716 TCP_INC_STATS_BH(net
, TCP_MIB_OUTRSTS
);
718 #ifdef CONFIG_TCP_MD5SIG
727 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
728 outside socket context is ugly, certainly. What can I do?
731 static void tcp_v4_send_ack(struct sk_buff
*skb
, u32 seq
, u32 ack
,
732 u32 win
, u32 tsval
, u32 tsecr
, int oif
,
733 struct tcp_md5sig_key
*key
,
734 int reply_flags
, u8 tos
)
736 const struct tcphdr
*th
= tcp_hdr(skb
);
739 __be32 opt
[(TCPOLEN_TSTAMP_ALIGNED
>> 2)
740 #ifdef CONFIG_TCP_MD5SIG
741 + (TCPOLEN_MD5SIG_ALIGNED
>> 2)
745 struct ip_reply_arg arg
;
746 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
748 memset(&rep
.th
, 0, sizeof(struct tcphdr
));
749 memset(&arg
, 0, sizeof(arg
));
751 arg
.iov
[0].iov_base
= (unsigned char *)&rep
;
752 arg
.iov
[0].iov_len
= sizeof(rep
.th
);
754 rep
.opt
[0] = htonl((TCPOPT_NOP
<< 24) | (TCPOPT_NOP
<< 16) |
755 (TCPOPT_TIMESTAMP
<< 8) |
757 rep
.opt
[1] = htonl(tsval
);
758 rep
.opt
[2] = htonl(tsecr
);
759 arg
.iov
[0].iov_len
+= TCPOLEN_TSTAMP_ALIGNED
;
762 /* Swap the send and the receive. */
763 rep
.th
.dest
= th
->source
;
764 rep
.th
.source
= th
->dest
;
765 rep
.th
.doff
= arg
.iov
[0].iov_len
/ 4;
766 rep
.th
.seq
= htonl(seq
);
767 rep
.th
.ack_seq
= htonl(ack
);
769 rep
.th
.window
= htons(win
);
771 #ifdef CONFIG_TCP_MD5SIG
773 int offset
= (tsecr
) ? 3 : 0;
775 rep
.opt
[offset
++] = htonl((TCPOPT_NOP
<< 24) |
777 (TCPOPT_MD5SIG
<< 8) |
779 arg
.iov
[0].iov_len
+= TCPOLEN_MD5SIG_ALIGNED
;
780 rep
.th
.doff
= arg
.iov
[0].iov_len
/4;
782 tcp_v4_md5_hash_hdr((__u8
*) &rep
.opt
[offset
],
783 key
, ip_hdr(skb
)->saddr
,
784 ip_hdr(skb
)->daddr
, &rep
.th
);
787 arg
.flags
= reply_flags
;
788 arg
.csum
= csum_tcpudp_nofold(ip_hdr(skb
)->daddr
,
789 ip_hdr(skb
)->saddr
, /* XXX */
790 arg
.iov
[0].iov_len
, IPPROTO_TCP
, 0);
791 arg
.csumoffset
= offsetof(struct tcphdr
, check
) / 2;
793 arg
.bound_dev_if
= oif
;
795 ip_send_unicast_reply(*this_cpu_ptr(net
->ipv4
.tcp_sk
),
796 skb
, ip_hdr(skb
)->saddr
,
797 ip_hdr(skb
)->daddr
, &arg
, arg
.iov
[0].iov_len
);
799 TCP_INC_STATS_BH(net
, TCP_MIB_OUTSEGS
);
802 static void tcp_v4_timewait_ack(struct sock
*sk
, struct sk_buff
*skb
)
804 struct inet_timewait_sock
*tw
= inet_twsk(sk
);
805 struct tcp_timewait_sock
*tcptw
= tcp_twsk(sk
);
807 tcp_v4_send_ack(skb
, tcptw
->tw_snd_nxt
, tcptw
->tw_rcv_nxt
,
808 tcptw
->tw_rcv_wnd
>> tw
->tw_rcv_wscale
,
809 tcp_time_stamp
+ tcptw
->tw_ts_offset
,
812 tcp_twsk_md5_key(tcptw
),
813 tw
->tw_transparent
? IP_REPLY_ARG_NOSRCCHECK
: 0,
820 static void tcp_v4_reqsk_send_ack(struct sock
*sk
, struct sk_buff
*skb
,
821 struct request_sock
*req
)
823 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
824 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
826 tcp_v4_send_ack(skb
, (sk
->sk_state
== TCP_LISTEN
) ?
827 tcp_rsk(req
)->snt_isn
+ 1 : tcp_sk(sk
)->snd_nxt
,
828 tcp_rsk(req
)->rcv_nxt
,
829 req
->rcv_wnd
>> inet_rsk(req
)->rcv_wscale
,
833 tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&ip_hdr(skb
)->daddr
,
835 inet_rsk(req
)->no_srccheck
? IP_REPLY_ARG_NOSRCCHECK
: 0,
840 * Send a SYN-ACK after having received a SYN.
841 * This still operates on a request_sock only, not on a big
844 static int tcp_v4_send_synack(struct sock
*sk
, struct dst_entry
*dst
,
845 struct request_sock
*req
,
849 const struct inet_request_sock
*ireq
= inet_rsk(req
);
852 struct sk_buff
* skb
;
854 /* First, grab a route. */
855 if (!dst
&& (dst
= inet_csk_route_req(sk
, &fl4
, req
)) == NULL
)
858 skb
= tcp_make_synack(sk
, dst
, req
, NULL
);
861 __tcp_v4_send_check(skb
, ireq
->loc_addr
, ireq
->rmt_addr
);
863 skb_set_queue_mapping(skb
, queue_mapping
);
864 err
= ip_build_and_send_pkt(skb
, sk
, ireq
->loc_addr
,
867 err
= net_xmit_eval(err
);
868 if (!tcp_rsk(req
)->snt_synack
&& !err
)
869 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
875 static int tcp_v4_rtx_synack(struct sock
*sk
, struct request_sock
*req
)
877 int res
= tcp_v4_send_synack(sk
, NULL
, req
, 0, false);
880 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_RETRANSSEGS
);
885 * IPv4 request_sock destructor.
887 static void tcp_v4_reqsk_destructor(struct request_sock
*req
)
889 kfree(inet_rsk(req
)->opt
);
893 * Return true if a syncookie should be sent
895 bool tcp_syn_flood_action(struct sock
*sk
,
896 const struct sk_buff
*skb
,
899 const char *msg
= "Dropping request";
900 bool want_cookie
= false;
901 struct listen_sock
*lopt
;
905 #ifdef CONFIG_SYN_COOKIES
906 if (sysctl_tcp_syncookies
) {
907 msg
= "Sending cookies";
909 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPREQQFULLDOCOOKIES
);
912 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPREQQFULLDROP
);
914 lopt
= inet_csk(sk
)->icsk_accept_queue
.listen_opt
;
915 if (!lopt
->synflood_warned
) {
916 lopt
->synflood_warned
= 1;
917 pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
918 proto
, ntohs(tcp_hdr(skb
)->dest
), msg
);
922 EXPORT_SYMBOL(tcp_syn_flood_action
);
925 * Save and compile IPv4 options into the request_sock if needed.
927 static struct ip_options_rcu
*tcp_v4_save_options(struct sk_buff
*skb
)
929 const struct ip_options
*opt
= &(IPCB(skb
)->opt
);
930 struct ip_options_rcu
*dopt
= NULL
;
932 if (opt
&& opt
->optlen
) {
933 int opt_size
= sizeof(*dopt
) + opt
->optlen
;
935 dopt
= kmalloc(opt_size
, GFP_ATOMIC
);
937 if (ip_options_echo(&dopt
->opt
, skb
)) {
946 #ifdef CONFIG_TCP_MD5SIG
948 * RFC2385 MD5 checksumming requires a mapping of
949 * IP address->MD5 Key.
950 * We need to maintain these in the sk structure.
953 /* Find the Key structure for an address. */
954 struct tcp_md5sig_key
*tcp_md5_do_lookup(struct sock
*sk
,
955 const union tcp_md5_addr
*addr
,
958 struct tcp_sock
*tp
= tcp_sk(sk
);
959 struct tcp_md5sig_key
*key
;
960 unsigned int size
= sizeof(struct in_addr
);
961 struct tcp_md5sig_info
*md5sig
;
963 /* caller either holds rcu_read_lock() or socket lock */
964 md5sig
= rcu_dereference_check(tp
->md5sig_info
,
965 sock_owned_by_user(sk
) ||
966 lockdep_is_held(&sk
->sk_lock
.slock
));
969 #if IS_ENABLED(CONFIG_IPV6)
970 if (family
== AF_INET6
)
971 size
= sizeof(struct in6_addr
);
973 hlist_for_each_entry_rcu(key
, &md5sig
->head
, node
) {
974 if (key
->family
!= family
)
976 if (!memcmp(&key
->addr
, addr
, size
))
981 EXPORT_SYMBOL(tcp_md5_do_lookup
);
983 struct tcp_md5sig_key
*tcp_v4_md5_lookup(struct sock
*sk
,
984 struct sock
*addr_sk
)
986 union tcp_md5_addr
*addr
;
988 addr
= (union tcp_md5_addr
*)&inet_sk(addr_sk
)->inet_daddr
;
989 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
991 EXPORT_SYMBOL(tcp_v4_md5_lookup
);
993 static struct tcp_md5sig_key
*tcp_v4_reqsk_md5_lookup(struct sock
*sk
,
994 struct request_sock
*req
)
996 union tcp_md5_addr
*addr
;
998 addr
= (union tcp_md5_addr
*)&inet_rsk(req
)->rmt_addr
;
999 return tcp_md5_do_lookup(sk
, addr
, AF_INET
);
1002 /* This can be called on a newly created socket, from other files */
1003 int tcp_md5_do_add(struct sock
*sk
, const union tcp_md5_addr
*addr
,
1004 int family
, const u8
*newkey
, u8 newkeylen
, gfp_t gfp
)
1006 /* Add Key to the list */
1007 struct tcp_md5sig_key
*key
;
1008 struct tcp_sock
*tp
= tcp_sk(sk
);
1009 struct tcp_md5sig_info
*md5sig
;
1011 key
= tcp_md5_do_lookup(sk
, addr
, family
);
1013 /* Pre-existing entry - just update that one. */
1014 memcpy(key
->key
, newkey
, newkeylen
);
1015 key
->keylen
= newkeylen
;
1019 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
1020 sock_owned_by_user(sk
) ||
1021 lockdep_is_held(&sk
->sk_lock
.slock
));
1023 md5sig
= kmalloc(sizeof(*md5sig
), gfp
);
1027 sk_nocaps_add(sk
, NETIF_F_GSO_MASK
);
1028 INIT_HLIST_HEAD(&md5sig
->head
);
1029 rcu_assign_pointer(tp
->md5sig_info
, md5sig
);
1032 key
= sock_kmalloc(sk
, sizeof(*key
), gfp
);
1035 if (hlist_empty(&md5sig
->head
) && !tcp_alloc_md5sig_pool(sk
)) {
1036 sock_kfree_s(sk
, key
, sizeof(*key
));
1040 memcpy(key
->key
, newkey
, newkeylen
);
1041 key
->keylen
= newkeylen
;
1042 key
->family
= family
;
1043 memcpy(&key
->addr
, addr
,
1044 (family
== AF_INET6
) ? sizeof(struct in6_addr
) :
1045 sizeof(struct in_addr
));
1046 hlist_add_head_rcu(&key
->node
, &md5sig
->head
);
1049 EXPORT_SYMBOL(tcp_md5_do_add
);
1051 int tcp_md5_do_del(struct sock
*sk
, const union tcp_md5_addr
*addr
, int family
)
1053 struct tcp_sock
*tp
= tcp_sk(sk
);
1054 struct tcp_md5sig_key
*key
;
1055 struct tcp_md5sig_info
*md5sig
;
1057 key
= tcp_md5_do_lookup(sk
, addr
, family
);
1060 hlist_del_rcu(&key
->node
);
1061 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
1062 kfree_rcu(key
, rcu
);
1063 md5sig
= rcu_dereference_protected(tp
->md5sig_info
,
1064 sock_owned_by_user(sk
));
1065 if (hlist_empty(&md5sig
->head
))
1066 tcp_free_md5sig_pool();
1069 EXPORT_SYMBOL(tcp_md5_do_del
);
1071 static void tcp_clear_md5_list(struct sock
*sk
)
1073 struct tcp_sock
*tp
= tcp_sk(sk
);
1074 struct tcp_md5sig_key
*key
;
1075 struct hlist_node
*n
;
1076 struct tcp_md5sig_info
*md5sig
;
1078 md5sig
= rcu_dereference_protected(tp
->md5sig_info
, 1);
1080 if (!hlist_empty(&md5sig
->head
))
1081 tcp_free_md5sig_pool();
1082 hlist_for_each_entry_safe(key
, n
, &md5sig
->head
, node
) {
1083 hlist_del_rcu(&key
->node
);
1084 atomic_sub(sizeof(*key
), &sk
->sk_omem_alloc
);
1085 kfree_rcu(key
, rcu
);
1089 static int tcp_v4_parse_md5_keys(struct sock
*sk
, char __user
*optval
,
1092 struct tcp_md5sig cmd
;
1093 struct sockaddr_in
*sin
= (struct sockaddr_in
*)&cmd
.tcpm_addr
;
1095 if (optlen
< sizeof(cmd
))
1098 if (copy_from_user(&cmd
, optval
, sizeof(cmd
)))
1101 if (sin
->sin_family
!= AF_INET
)
1104 if (!cmd
.tcpm_key
|| !cmd
.tcpm_keylen
)
1105 return tcp_md5_do_del(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1108 if (cmd
.tcpm_keylen
> TCP_MD5SIG_MAXKEYLEN
)
1111 return tcp_md5_do_add(sk
, (union tcp_md5_addr
*)&sin
->sin_addr
.s_addr
,
1112 AF_INET
, cmd
.tcpm_key
, cmd
.tcpm_keylen
,
1116 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool
*hp
,
1117 __be32 daddr
, __be32 saddr
, int nbytes
)
1119 struct tcp4_pseudohdr
*bp
;
1120 struct scatterlist sg
;
1122 bp
= &hp
->md5_blk
.ip4
;
1125 * 1. the TCP pseudo-header (in the order: source IP address,
1126 * destination IP address, zero-padded protocol number, and
1132 bp
->protocol
= IPPROTO_TCP
;
1133 bp
->len
= cpu_to_be16(nbytes
);
1135 sg_init_one(&sg
, bp
, sizeof(*bp
));
1136 return crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(*bp
));
1139 static int tcp_v4_md5_hash_hdr(char *md5_hash
, const struct tcp_md5sig_key
*key
,
1140 __be32 daddr
, __be32 saddr
, const struct tcphdr
*th
)
1142 struct tcp_md5sig_pool
*hp
;
1143 struct hash_desc
*desc
;
1145 hp
= tcp_get_md5sig_pool();
1147 goto clear_hash_noput
;
1148 desc
= &hp
->md5_desc
;
1150 if (crypto_hash_init(desc
))
1152 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, th
->doff
<< 2))
1154 if (tcp_md5_hash_header(hp
, th
))
1156 if (tcp_md5_hash_key(hp
, key
))
1158 if (crypto_hash_final(desc
, md5_hash
))
1161 tcp_put_md5sig_pool();
1165 tcp_put_md5sig_pool();
1167 memset(md5_hash
, 0, 16);
1171 int tcp_v4_md5_hash_skb(char *md5_hash
, struct tcp_md5sig_key
*key
,
1172 const struct sock
*sk
, const struct request_sock
*req
,
1173 const struct sk_buff
*skb
)
1175 struct tcp_md5sig_pool
*hp
;
1176 struct hash_desc
*desc
;
1177 const struct tcphdr
*th
= tcp_hdr(skb
);
1178 __be32 saddr
, daddr
;
1181 saddr
= inet_sk(sk
)->inet_saddr
;
1182 daddr
= inet_sk(sk
)->inet_daddr
;
1184 saddr
= inet_rsk(req
)->loc_addr
;
1185 daddr
= inet_rsk(req
)->rmt_addr
;
1187 const struct iphdr
*iph
= ip_hdr(skb
);
1192 hp
= tcp_get_md5sig_pool();
1194 goto clear_hash_noput
;
1195 desc
= &hp
->md5_desc
;
1197 if (crypto_hash_init(desc
))
1200 if (tcp_v4_md5_hash_pseudoheader(hp
, daddr
, saddr
, skb
->len
))
1202 if (tcp_md5_hash_header(hp
, th
))
1204 if (tcp_md5_hash_skb_data(hp
, skb
, th
->doff
<< 2))
1206 if (tcp_md5_hash_key(hp
, key
))
1208 if (crypto_hash_final(desc
, md5_hash
))
1211 tcp_put_md5sig_pool();
1215 tcp_put_md5sig_pool();
1217 memset(md5_hash
, 0, 16);
1220 EXPORT_SYMBOL(tcp_v4_md5_hash_skb
);
1222 static bool tcp_v4_inbound_md5_hash(struct sock
*sk
, const struct sk_buff
*skb
)
1225 * This gets called for each TCP segment that arrives
1226 * so we want to be efficient.
1227 * We have 3 drop cases:
1228 * o No MD5 hash and one expected.
1229 * o MD5 hash and we're not expecting one.
1230 * o MD5 hash and its wrong.
1232 const __u8
*hash_location
= NULL
;
1233 struct tcp_md5sig_key
*hash_expected
;
1234 const struct iphdr
*iph
= ip_hdr(skb
);
1235 const struct tcphdr
*th
= tcp_hdr(skb
);
1237 unsigned char newhash
[16];
1239 hash_expected
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&iph
->saddr
,
1241 hash_location
= tcp_parse_md5sig_option(th
);
1243 /* We've parsed the options - do we have a hash? */
1244 if (!hash_expected
&& !hash_location
)
1247 if (hash_expected
&& !hash_location
) {
1248 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5NOTFOUND
);
1252 if (!hash_expected
&& hash_location
) {
1253 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPMD5UNEXPECTED
);
1257 /* Okay, so this is hash_expected and hash_location -
1258 * so we need to calculate the checksum.
1260 genhash
= tcp_v4_md5_hash_skb(newhash
,
1264 if (genhash
|| memcmp(hash_location
, newhash
, 16) != 0) {
1265 net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1266 &iph
->saddr
, ntohs(th
->source
),
1267 &iph
->daddr
, ntohs(th
->dest
),
1268 genhash
? " tcp_v4_calc_md5_hash failed"
1277 struct request_sock_ops tcp_request_sock_ops __read_mostly
= {
1279 .obj_size
= sizeof(struct tcp_request_sock
),
1280 .rtx_syn_ack
= tcp_v4_rtx_synack
,
1281 .send_ack
= tcp_v4_reqsk_send_ack
,
1282 .destructor
= tcp_v4_reqsk_destructor
,
1283 .send_reset
= tcp_v4_send_reset
,
1284 .syn_ack_timeout
= tcp_syn_ack_timeout
,
1287 #ifdef CONFIG_TCP_MD5SIG
1288 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops
= {
1289 .md5_lookup
= tcp_v4_reqsk_md5_lookup
,
1290 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
1294 static bool tcp_fastopen_check(struct sock
*sk
, struct sk_buff
*skb
,
1295 struct request_sock
*req
,
1296 struct tcp_fastopen_cookie
*foc
,
1297 struct tcp_fastopen_cookie
*valid_foc
)
1299 bool skip_cookie
= false;
1300 struct fastopen_queue
*fastopenq
;
1302 if (likely(!fastopen_cookie_present(foc
))) {
1303 /* See include/net/tcp.h for the meaning of these knobs */
1304 if ((sysctl_tcp_fastopen
& TFO_SERVER_ALWAYS
) ||
1305 ((sysctl_tcp_fastopen
& TFO_SERVER_COOKIE_NOT_REQD
) &&
1306 (TCP_SKB_CB(skb
)->end_seq
!= TCP_SKB_CB(skb
)->seq
+ 1)))
1307 skip_cookie
= true; /* no cookie to validate */
1311 fastopenq
= inet_csk(sk
)->icsk_accept_queue
.fastopenq
;
1312 /* A FO option is present; bump the counter. */
1313 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_TCPFASTOPENPASSIVE
);
1315 /* Make sure the listener has enabled fastopen, and we don't
1316 * exceed the max # of pending TFO requests allowed before trying
1317 * to validating the cookie in order to avoid burning CPU cycles
1320 * XXX (TFO) - The implication of checking the max_qlen before
1321 * processing a cookie request is that clients can't differentiate
1322 * between qlen overflow causing Fast Open to be disabled
1323 * temporarily vs a server not supporting Fast Open at all.
1325 if ((sysctl_tcp_fastopen
& TFO_SERVER_ENABLE
) == 0 ||
1326 fastopenq
== NULL
|| fastopenq
->max_qlen
== 0)
1329 if (fastopenq
->qlen
>= fastopenq
->max_qlen
) {
1330 struct request_sock
*req1
;
1331 spin_lock(&fastopenq
->lock
);
1332 req1
= fastopenq
->rskq_rst_head
;
1333 if ((req1
== NULL
) || time_after(req1
->expires
, jiffies
)) {
1334 spin_unlock(&fastopenq
->lock
);
1335 NET_INC_STATS_BH(sock_net(sk
),
1336 LINUX_MIB_TCPFASTOPENLISTENOVERFLOW
);
1337 /* Avoid bumping LINUX_MIB_TCPFASTOPENPASSIVEFAIL*/
1341 fastopenq
->rskq_rst_head
= req1
->dl_next
;
1343 spin_unlock(&fastopenq
->lock
);
1347 tcp_rsk(req
)->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1350 if (foc
->len
== TCP_FASTOPEN_COOKIE_SIZE
) {
1351 if ((sysctl_tcp_fastopen
& TFO_SERVER_COOKIE_NOT_CHKED
) == 0) {
1352 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1353 if ((valid_foc
->len
!= TCP_FASTOPEN_COOKIE_SIZE
) ||
1354 memcmp(&foc
->val
[0], &valid_foc
->val
[0],
1355 TCP_FASTOPEN_COOKIE_SIZE
) != 0)
1357 valid_foc
->len
= -1;
1359 /* Acknowledge the data received from the peer. */
1360 tcp_rsk(req
)->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1362 } else if (foc
->len
== 0) { /* Client requesting a cookie */
1363 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1364 NET_INC_STATS_BH(sock_net(sk
),
1365 LINUX_MIB_TCPFASTOPENCOOKIEREQD
);
1367 /* Client sent a cookie with wrong size. Treat it
1368 * the same as invalid and return a valid one.
1370 tcp_fastopen_cookie_gen(ip_hdr(skb
)->saddr
, valid_foc
);
1375 static int tcp_v4_conn_req_fastopen(struct sock
*sk
,
1376 struct sk_buff
*skb
,
1377 struct sk_buff
*skb_synack
,
1378 struct request_sock
*req
)
1380 struct tcp_sock
*tp
= tcp_sk(sk
);
1381 struct request_sock_queue
*queue
= &inet_csk(sk
)->icsk_accept_queue
;
1382 const struct inet_request_sock
*ireq
= inet_rsk(req
);
1386 req
->num_retrans
= 0;
1387 req
->num_timeout
= 0;
1390 child
= inet_csk(sk
)->icsk_af_ops
->syn_recv_sock(sk
, skb
, req
, NULL
);
1391 if (child
== NULL
) {
1392 NET_INC_STATS_BH(sock_net(sk
),
1393 LINUX_MIB_TCPFASTOPENPASSIVEFAIL
);
1394 kfree_skb(skb_synack
);
1397 err
= ip_build_and_send_pkt(skb_synack
, sk
, ireq
->loc_addr
,
1398 ireq
->rmt_addr
, ireq
->opt
);
1399 err
= net_xmit_eval(err
);
1401 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
1402 /* XXX (TFO) - is it ok to ignore error and continue? */
1404 spin_lock(&queue
->fastopenq
->lock
);
1405 queue
->fastopenq
->qlen
++;
1406 spin_unlock(&queue
->fastopenq
->lock
);
1408 /* Initialize the child socket. Have to fix some values to take
1409 * into account the child is a Fast Open socket and is created
1410 * only out of the bits carried in the SYN packet.
1414 tp
->fastopen_rsk
= req
;
1415 /* Do a hold on the listner sk so that if the listener is being
1416 * closed, the child that has been accepted can live on and still
1417 * access listen_lock.
1420 tcp_rsk(req
)->listener
= sk
;
1422 /* RFC1323: The window in SYN & SYN/ACK segments is never
1423 * scaled. So correct it appropriately.
1425 tp
->snd_wnd
= ntohs(tcp_hdr(skb
)->window
);
1426 tp
->max_window
= tp
->snd_wnd
;
1428 /* Activate the retrans timer so that SYNACK can be retransmitted.
1429 * The request socket is not added to the SYN table of the parent
1430 * because it's been added to the accept queue directly.
1432 inet_csk_reset_xmit_timer(child
, ICSK_TIME_RETRANS
,
1433 TCP_TIMEOUT_INIT
, sysctl_tcp_rto_max
);
1435 /* Add the child socket directly into the accept queue */
1436 inet_csk_reqsk_queue_add(sk
, req
, child
);
1438 /* Now finish processing the fastopen child socket. */
1439 inet_csk(child
)->icsk_af_ops
->rebuild_header(child
);
1440 tcp_init_congestion_control(child
);
1441 tcp_mtup_init(child
);
1442 tcp_init_buffer_space(child
);
1443 tcp_init_metrics(child
);
1445 /* Queue the data carried in the SYN packet. We need to first
1446 * bump skb's refcnt because the caller will attempt to free it.
1448 * XXX (TFO) - we honor a zero-payload TFO request for now.
1449 * (Any reason not to?)
1451 if (TCP_SKB_CB(skb
)->end_seq
== TCP_SKB_CB(skb
)->seq
+ 1) {
1452 /* Don't queue the skb if there is no payload in SYN.
1453 * XXX (TFO) - How about SYN+FIN?
1455 tp
->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1459 __skb_pull(skb
, tcp_hdr(skb
)->doff
* 4);
1460 skb_set_owner_r(skb
, child
);
1461 __skb_queue_tail(&child
->sk_receive_queue
, skb
);
1462 tp
->rcv_nxt
= TCP_SKB_CB(skb
)->end_seq
;
1463 tp
->syn_data_acked
= 1;
1465 sk
->sk_data_ready(sk
, 0);
1466 bh_unlock_sock(child
);
1468 WARN_ON(req
->sk
== NULL
);
1472 int tcp_v4_conn_request(struct sock
*sk
, struct sk_buff
*skb
)
1474 struct tcp_options_received tmp_opt
;
1475 struct request_sock
*req
;
1476 struct inet_request_sock
*ireq
;
1477 struct tcp_sock
*tp
= tcp_sk(sk
);
1478 struct dst_entry
*dst
= NULL
;
1479 __be32 saddr
= ip_hdr(skb
)->saddr
;
1480 __be32 daddr
= ip_hdr(skb
)->daddr
;
1481 __u32 isn
= TCP_SKB_CB(skb
)->when
;
1482 bool want_cookie
= false;
1484 struct tcp_fastopen_cookie foc
= { .len
= -1 };
1485 struct tcp_fastopen_cookie valid_foc
= { .len
= -1 };
1486 struct sk_buff
*skb_synack
;
1489 /* Never answer to SYNs send to broadcast or multicast */
1490 if (skb_rtable(skb
)->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
))
1493 /* TW buckets are converted to open requests without
1494 * limitations, they conserve resources and peer is
1495 * evidently real one.
1497 if (inet_csk_reqsk_queue_is_full(sk
) && !isn
) {
1498 want_cookie
= tcp_syn_flood_action(sk
, skb
, "TCP");
1503 /* Accept backlog is full. If we have already queued enough
1504 * of warm entries in syn queue, drop request. It is better than
1505 * clogging syn queue with openreqs with exponentially increasing
1508 if (sk_acceptq_is_full(sk
) && inet_csk_reqsk_queue_young(sk
) > 1) {
1509 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1513 req
= inet_reqsk_alloc(&tcp_request_sock_ops
);
1517 #ifdef CONFIG_TCP_MD5SIG
1518 tcp_rsk(req
)->af_specific
= &tcp_request_sock_ipv4_ops
;
1521 tcp_clear_options(&tmp_opt
);
1522 tmp_opt
.mss_clamp
= TCP_MSS_DEFAULT
;
1523 tmp_opt
.user_mss
= tp
->rx_opt
.user_mss
;
1524 tcp_parse_options(skb
, &tmp_opt
, 0, want_cookie
? NULL
: &foc
);
1526 if (want_cookie
&& !tmp_opt
.saw_tstamp
)
1527 tcp_clear_options(&tmp_opt
);
1529 tmp_opt
.tstamp_ok
= tmp_opt
.saw_tstamp
;
1530 tcp_openreq_init(req
, &tmp_opt
, skb
);
1532 ireq
= inet_rsk(req
);
1533 ireq
->loc_addr
= daddr
;
1534 ireq
->rmt_addr
= saddr
;
1535 ireq
->no_srccheck
= inet_sk(sk
)->transparent
;
1536 ireq
->opt
= tcp_v4_save_options(skb
);
1537 ireq
->ir_mark
= inet_request_mark(sk
, skb
);
1539 if (security_inet_conn_request(sk
, skb
, req
))
1542 if (!want_cookie
|| tmp_opt
.tstamp_ok
)
1543 TCP_ECN_create_request(req
, skb
, sock_net(sk
));
1546 isn
= cookie_v4_init_sequence(sk
, skb
, &req
->mss
);
1547 req
->cookie_ts
= tmp_opt
.tstamp_ok
;
1549 /* VJ's idea. We save last timestamp seen
1550 * from the destination in peer table, when entering
1551 * state TIME-WAIT, and check against it before
1552 * accepting new connection request.
1554 * If "isn" is not zero, this request hit alive
1555 * timewait bucket, so that all the necessary checks
1556 * are made in the function processing timewait state.
1558 if (tmp_opt
.saw_tstamp
&&
1559 tcp_death_row
.sysctl_tw_recycle
&&
1560 (dst
= inet_csk_route_req(sk
, &fl4
, req
)) != NULL
&&
1561 fl4
.daddr
== saddr
) {
1562 if (!tcp_peer_is_proven(req
, dst
, true)) {
1563 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_PAWSPASSIVEREJECTED
);
1564 goto drop_and_release
;
1567 /* Kill the following clause, if you dislike this way. */
1568 else if (!sysctl_tcp_syncookies
&&
1569 (sysctl_max_syn_backlog
- inet_csk_reqsk_queue_len(sk
) <
1570 (sysctl_max_syn_backlog
>> 2)) &&
1571 !tcp_peer_is_proven(req
, dst
, false)) {
1572 /* Without syncookies last quarter of
1573 * backlog is filled with destinations,
1574 * proven to be alive.
1575 * It means that we continue to communicate
1576 * to destinations, already remembered
1577 * to the moment of synflood.
1579 LIMIT_NETDEBUG(KERN_DEBUG
pr_fmt("drop open request from %pI4/%u\n"),
1580 &saddr
, ntohs(tcp_hdr(skb
)->source
));
1581 goto drop_and_release
;
1584 isn
= tcp_v4_init_sequence(skb
);
1586 tcp_rsk(req
)->snt_isn
= isn
;
1589 dst
= inet_csk_route_req(sk
, &fl4
, req
);
1593 do_fastopen
= tcp_fastopen_check(sk
, skb
, req
, &foc
, &valid_foc
);
1595 /* We don't call tcp_v4_send_synack() directly because we need
1596 * to make sure a child socket can be created successfully before
1597 * sending back synack!
1599 * XXX (TFO) - Ideally one would simply call tcp_v4_send_synack()
1600 * (or better yet, call tcp_send_synack() in the child context
1601 * directly, but will have to fix bunch of other code first)
1602 * after syn_recv_sock() except one will need to first fix the
1603 * latter to remove its dependency on the current implementation
1604 * of tcp_v4_send_synack()->tcp_select_initial_window().
1606 skb_synack
= tcp_make_synack(sk
, dst
, req
,
1607 fastopen_cookie_present(&valid_foc
) ? &valid_foc
: NULL
);
1610 __tcp_v4_send_check(skb_synack
, ireq
->loc_addr
, ireq
->rmt_addr
);
1611 skb_set_queue_mapping(skb_synack
, skb_get_queue_mapping(skb
));
1615 if (likely(!do_fastopen
)) {
1617 err
= ip_build_and_send_pkt(skb_synack
, sk
, ireq
->loc_addr
,
1618 ireq
->rmt_addr
, ireq
->opt
);
1619 err
= net_xmit_eval(err
);
1620 if (err
|| want_cookie
)
1623 tcp_rsk(req
)->snt_synack
= tcp_time_stamp
;
1624 tcp_rsk(req
)->listener
= NULL
;
1625 /* Add the request_sock to the SYN table */
1626 inet_csk_reqsk_queue_hash_add(sk
, req
, TCP_TIMEOUT_INIT
);
1627 if (fastopen_cookie_present(&foc
) && foc
.len
!= 0)
1628 NET_INC_STATS_BH(sock_net(sk
),
1629 LINUX_MIB_TCPFASTOPENPASSIVEFAIL
);
1630 } else if (tcp_v4_conn_req_fastopen(sk
, skb
, skb_synack
, req
))
1640 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1643 EXPORT_SYMBOL(tcp_v4_conn_request
);
1647 * The three way handshake has completed - we got a valid synack -
1648 * now create the new socket.
1650 struct sock
*tcp_v4_syn_recv_sock(struct sock
*sk
, struct sk_buff
*skb
,
1651 struct request_sock
*req
,
1652 struct dst_entry
*dst
)
1654 struct inet_request_sock
*ireq
;
1655 struct inet_sock
*newinet
;
1656 struct tcp_sock
*newtp
;
1658 #ifdef CONFIG_TCP_MD5SIG
1659 struct tcp_md5sig_key
*key
;
1661 struct ip_options_rcu
*inet_opt
;
1663 if (sk_acceptq_is_full(sk
))
1666 newsk
= tcp_create_openreq_child(sk
, req
, skb
);
1670 newsk
->sk_gso_type
= SKB_GSO_TCPV4
;
1671 inet_sk_rx_dst_set(newsk
, skb
);
1673 newtp
= tcp_sk(newsk
);
1674 newinet
= inet_sk(newsk
);
1675 ireq
= inet_rsk(req
);
1676 newinet
->inet_daddr
= ireq
->rmt_addr
;
1677 newinet
->inet_rcv_saddr
= ireq
->loc_addr
;
1678 newinet
->inet_saddr
= ireq
->loc_addr
;
1679 inet_opt
= ireq
->opt
;
1680 rcu_assign_pointer(newinet
->inet_opt
, inet_opt
);
1682 newinet
->mc_index
= inet_iif(skb
);
1683 newinet
->mc_ttl
= ip_hdr(skb
)->ttl
;
1684 newinet
->rcv_tos
= ip_hdr(skb
)->tos
;
1685 inet_csk(newsk
)->icsk_ext_hdr_len
= 0;
1687 inet_csk(newsk
)->icsk_ext_hdr_len
= inet_opt
->opt
.optlen
;
1688 newinet
->inet_id
= newtp
->write_seq
^ jiffies
;
1691 dst
= inet_csk_route_child_sock(sk
, newsk
, req
);
1695 /* syncookie case : see end of cookie_v4_check() */
1697 sk_setup_caps(newsk
, dst
);
1699 tcp_mtup_init(newsk
);
1700 tcp_sync_mss(newsk
, dst_mtu(dst
));
1701 newtp
->advmss
= dst_metric_advmss(dst
);
1702 if (tcp_sk(sk
)->rx_opt
.user_mss
&&
1703 tcp_sk(sk
)->rx_opt
.user_mss
< newtp
->advmss
)
1704 newtp
->advmss
= tcp_sk(sk
)->rx_opt
.user_mss
;
1706 tcp_initialize_rcv_mss(newsk
);
1707 tcp_synack_rtt_meas(newsk
, req
);
1708 newtp
->total_retrans
= req
->num_retrans
;
1710 #ifdef CONFIG_TCP_MD5SIG
1711 /* Copy over the MD5 key from the original socket */
1712 key
= tcp_md5_do_lookup(sk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1716 * We're using one, so create a matching key
1717 * on the newsk structure. If we fail to get
1718 * memory, then we end up not copying the key
1721 tcp_md5_do_add(newsk
, (union tcp_md5_addr
*)&newinet
->inet_daddr
,
1722 AF_INET
, key
->key
, key
->keylen
, GFP_ATOMIC
);
1723 sk_nocaps_add(newsk
, NETIF_F_GSO_MASK
);
1727 if (__inet_inherit_port(sk
, newsk
) < 0)
1729 __inet_hash_nolisten(newsk
, NULL
);
1734 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENOVERFLOWS
);
1738 NET_INC_STATS_BH(sock_net(sk
), LINUX_MIB_LISTENDROPS
);
1741 inet_csk_prepare_forced_close(newsk
);
1745 EXPORT_SYMBOL(tcp_v4_syn_recv_sock
);
1747 static struct sock
*tcp_v4_hnd_req(struct sock
*sk
, struct sk_buff
*skb
)
1749 struct tcphdr
*th
= tcp_hdr(skb
);
1750 const struct iphdr
*iph
= ip_hdr(skb
);
1752 struct request_sock
**prev
;
1753 /* Find possible connection requests. */
1754 struct request_sock
*req
= inet_csk_search_req(sk
, &prev
, th
->source
,
1755 iph
->saddr
, iph
->daddr
);
1757 return tcp_check_req(sk
, skb
, req
, prev
, false);
1759 nsk
= inet_lookup_established(sock_net(sk
), &tcp_hashinfo
, iph
->saddr
,
1760 th
->source
, iph
->daddr
, th
->dest
, inet_iif(skb
));
1763 if (nsk
->sk_state
!= TCP_TIME_WAIT
) {
1767 inet_twsk_put(inet_twsk(nsk
));
1771 #ifdef CONFIG_SYN_COOKIES
1773 sk
= cookie_v4_check(sk
, skb
, &(IPCB(skb
)->opt
));
1778 static __sum16
tcp_v4_checksum_init(struct sk_buff
*skb
)
1780 const struct iphdr
*iph
= ip_hdr(skb
);
1782 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
1783 if (!tcp_v4_check(skb
->len
, iph
->saddr
,
1784 iph
->daddr
, skb
->csum
)) {
1785 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1790 skb
->csum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
1791 skb
->len
, IPPROTO_TCP
, 0);
1793 if (skb
->len
<= 76) {
1794 return __skb_checksum_complete(skb
);
1800 /* The socket must have it's spinlock held when we get
1803 * We have a potential double-lock case here, so even when
1804 * doing backlog processing we use the BH locking scheme.
1805 * This is because we cannot sleep with the original spinlock
1808 int tcp_v4_do_rcv(struct sock
*sk
, struct sk_buff
*skb
)
1811 #ifdef CONFIG_TCP_MD5SIG
1813 * We really want to reject the packet as early as possible
1815 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1816 * o There is an MD5 option and we're not expecting one
1818 if (tcp_v4_inbound_md5_hash(sk
, skb
))
1822 if (sk
->sk_state
== TCP_ESTABLISHED
) { /* Fast path */
1823 struct dst_entry
*dst
= sk
->sk_rx_dst
;
1825 sock_rps_save_rxhash(sk
, skb
);
1827 if (inet_sk(sk
)->rx_dst_ifindex
!= skb
->skb_iif
||
1828 dst
->ops
->check(dst
, 0) == NULL
) {
1830 sk
->sk_rx_dst
= NULL
;
1833 if (tcp_rcv_established(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1840 if (skb
->len
< tcp_hdrlen(skb
) || tcp_checksum_complete(skb
))
1843 if (sk
->sk_state
== TCP_LISTEN
) {
1844 struct sock
*nsk
= tcp_v4_hnd_req(sk
, skb
);
1849 sock_rps_save_rxhash(nsk
, skb
);
1850 if (tcp_child_process(sk
, nsk
, skb
)) {
1857 sock_rps_save_rxhash(sk
, skb
);
1859 if (tcp_rcv_state_process(sk
, skb
, tcp_hdr(skb
), skb
->len
)) {
1866 tcp_v4_send_reset(rsk
, skb
);
1869 /* Be careful here. If this function gets more complicated and
1870 * gcc suffers from register pressure on the x86, sk (in %ebx)
1871 * might be destroyed here. This current version compiles correctly,
1872 * but you have been warned.
1877 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_CSUMERRORS
);
1878 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_INERRS
);
1881 EXPORT_SYMBOL(tcp_v4_do_rcv
);
1883 void tcp_v4_early_demux(struct sk_buff
*skb
)
1885 const struct iphdr
*iph
;
1886 const struct tcphdr
*th
;
1889 if (skb
->pkt_type
!= PACKET_HOST
)
1892 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + sizeof(struct tcphdr
)))
1898 if (th
->doff
< sizeof(struct tcphdr
) / 4)
1901 sk
= __inet_lookup_established(dev_net(skb
->dev
), &tcp_hashinfo
,
1902 iph
->saddr
, th
->source
,
1903 iph
->daddr
, ntohs(th
->dest
),
1907 skb
->destructor
= sock_edemux
;
1908 if (sk
->sk_state
!= TCP_TIME_WAIT
) {
1909 struct dst_entry
*dst
= ACCESS_ONCE(sk
->sk_rx_dst
);
1912 dst
= dst_check(dst
, 0);
1914 inet_sk(sk
)->rx_dst_ifindex
== skb
->skb_iif
)
1915 skb_dst_set_noref(skb
, dst
);
1920 /* Packet is added to VJ-style prequeue for processing in process
1921 * context, if a reader task is waiting. Apparently, this exciting
1922 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
1923 * failed somewhere. Latency? Burstiness? Well, at least now we will
1924 * see, why it failed. 8)8) --ANK
1927 bool tcp_prequeue(struct sock
*sk
, struct sk_buff
*skb
)
1929 struct tcp_sock
*tp
= tcp_sk(sk
);
1931 if (sysctl_tcp_low_latency
|| !tp
->ucopy
.task
)
1934 if (skb
->len
<= tcp_hdrlen(skb
) &&
1935 skb_queue_len(&tp
->ucopy
.prequeue
) == 0)
1939 __skb_queue_tail(&tp
->ucopy
.prequeue
, skb
);
1940 tp
->ucopy
.memory
+= skb
->truesize
;
1941 if (tp
->ucopy
.memory
> sk
->sk_rcvbuf
) {
1942 struct sk_buff
*skb1
;
1944 BUG_ON(sock_owned_by_user(sk
));
1946 while ((skb1
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
) {
1947 sk_backlog_rcv(sk
, skb1
);
1948 NET_INC_STATS_BH(sock_net(sk
),
1949 LINUX_MIB_TCPPREQUEUEDROPPED
);
1952 tp
->ucopy
.memory
= 0;
1953 } else if (skb_queue_len(&tp
->ucopy
.prequeue
) == 1) {
1954 wake_up_interruptible_sync_poll(sk_sleep(sk
),
1955 POLLIN
| POLLRDNORM
| POLLRDBAND
);
1956 if (!inet_csk_ack_scheduled(sk
))
1957 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_DACK
,
1958 (3 * tcp_rto_min(sk
)) / 4,
1959 sysctl_tcp_rto_max
);
1963 EXPORT_SYMBOL(tcp_prequeue
);
1965 int tcp_filter(struct sock
*sk
, struct sk_buff
*skb
)
1967 struct tcphdr
*th
= (struct tcphdr
*)skb
->data
;
1968 unsigned int eaten
= skb
->len
;
1971 err
= sk_filter_trim_cap(sk
, skb
, th
->doff
* 4);
1974 TCP_SKB_CB(skb
)->end_seq
-= eaten
;
1978 EXPORT_SYMBOL(tcp_filter
);
1984 int tcp_v4_rcv(struct sk_buff
*skb
)
1986 const struct iphdr
*iph
;
1987 const struct tcphdr
*th
;
1990 struct net
*net
= dev_net(skb
->dev
);
1992 if (skb
->pkt_type
!= PACKET_HOST
)
1995 /* Count it even if it's bad */
1996 TCP_INC_STATS_BH(net
, TCP_MIB_INSEGS
);
1998 if (!pskb_may_pull(skb
, sizeof(struct tcphdr
)))
2003 if (th
->doff
< sizeof(struct tcphdr
) / 4)
2005 if (!pskb_may_pull(skb
, th
->doff
* 4))
2008 /* An explanation is required here, I think.
2009 * Packet length and doff are validated by header prediction,
2010 * provided case of th->doff==0 is eliminated.
2011 * So, we defer the checks. */
2012 if (!skb_csum_unnecessary(skb
) && tcp_v4_checksum_init(skb
))
2017 TCP_SKB_CB(skb
)->seq
= ntohl(th
->seq
);
2018 TCP_SKB_CB(skb
)->end_seq
= (TCP_SKB_CB(skb
)->seq
+ th
->syn
+ th
->fin
+
2019 skb
->len
- th
->doff
* 4);
2020 TCP_SKB_CB(skb
)->ack_seq
= ntohl(th
->ack_seq
);
2021 TCP_SKB_CB(skb
)->when
= 0;
2022 TCP_SKB_CB(skb
)->ip_dsfield
= ipv4_get_dsfield(iph
);
2023 TCP_SKB_CB(skb
)->sacked
= 0;
2025 sk
= __inet_lookup_skb(&tcp_hashinfo
, skb
, th
->source
, th
->dest
);
2030 if (sk
->sk_state
== TCP_TIME_WAIT
)
2033 if (unlikely(iph
->ttl
< inet_sk(sk
)->min_ttl
)) {
2034 NET_INC_STATS_BH(net
, LINUX_MIB_TCPMINTTLDROP
);
2035 goto discard_and_relse
;
2038 if (!xfrm4_policy_check(sk
, XFRM_POLICY_IN
, skb
))
2039 goto discard_and_relse
;
2042 if (tcp_filter(sk
, skb
))
2043 goto discard_and_relse
;
2044 th
= (const struct tcphdr
*)skb
->data
;
2049 bh_lock_sock_nested(sk
);
2051 if (!sock_owned_by_user(sk
)) {
2052 #ifdef CONFIG_NET_DMA
2053 struct tcp_sock
*tp
= tcp_sk(sk
);
2054 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
2055 tp
->ucopy
.dma_chan
= net_dma_find_channel();
2056 if (tp
->ucopy
.dma_chan
)
2057 ret
= tcp_v4_do_rcv(sk
, skb
);
2061 if (!tcp_prequeue(sk
, skb
))
2062 ret
= tcp_v4_do_rcv(sk
, skb
);
2064 } else if (unlikely(sk_add_backlog(sk
, skb
,
2065 sk
->sk_rcvbuf
+ sk
->sk_sndbuf
))) {
2067 NET_INC_STATS_BH(net
, LINUX_MIB_TCPBACKLOGDROP
);
2068 goto discard_and_relse
;
2077 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
2080 if (skb
->len
< (th
->doff
<< 2) || tcp_checksum_complete(skb
)) {
2082 TCP_INC_STATS_BH(net
, TCP_MIB_CSUMERRORS
);
2084 TCP_INC_STATS_BH(net
, TCP_MIB_INERRS
);
2086 tcp_v4_send_reset(NULL
, skb
);
2090 /* Discard frame. */
2099 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
)) {
2100 inet_twsk_put(inet_twsk(sk
));
2104 if (skb
->len
< (th
->doff
<< 2)) {
2105 inet_twsk_put(inet_twsk(sk
));
2108 if (tcp_checksum_complete(skb
)) {
2109 inet_twsk_put(inet_twsk(sk
));
2112 switch (tcp_timewait_state_process(inet_twsk(sk
), skb
, th
)) {
2114 struct sock
*sk2
= inet_lookup_listener(dev_net(skb
->dev
),
2116 iph
->saddr
, th
->source
,
2117 iph
->daddr
, th
->dest
,
2120 inet_twsk_deschedule(inet_twsk(sk
), &tcp_death_row
);
2121 inet_twsk_put(inet_twsk(sk
));
2125 /* Fall through to ACK */
2128 tcp_v4_timewait_ack(sk
, skb
);
2132 case TCP_TW_SUCCESS
:;
2137 static struct timewait_sock_ops tcp_timewait_sock_ops
= {
2138 .twsk_obj_size
= sizeof(struct tcp_timewait_sock
),
2139 .twsk_unique
= tcp_twsk_unique
,
2140 .twsk_destructor
= tcp_twsk_destructor
,
2143 void inet_sk_rx_dst_set(struct sock
*sk
, const struct sk_buff
*skb
)
2145 struct dst_entry
*dst
= skb_dst(skb
);
2148 sk
->sk_rx_dst
= dst
;
2149 inet_sk(sk
)->rx_dst_ifindex
= skb
->skb_iif
;
2151 EXPORT_SYMBOL(inet_sk_rx_dst_set
);
2153 const struct inet_connection_sock_af_ops ipv4_specific
= {
2154 .queue_xmit
= ip_queue_xmit
,
2155 .send_check
= tcp_v4_send_check
,
2156 .rebuild_header
= inet_sk_rebuild_header
,
2157 .sk_rx_dst_set
= inet_sk_rx_dst_set
,
2158 .conn_request
= tcp_v4_conn_request
,
2159 .syn_recv_sock
= tcp_v4_syn_recv_sock
,
2160 .net_header_len
= sizeof(struct iphdr
),
2161 .setsockopt
= ip_setsockopt
,
2162 .getsockopt
= ip_getsockopt
,
2163 .addr2sockaddr
= inet_csk_addr2sockaddr
,
2164 .sockaddr_len
= sizeof(struct sockaddr_in
),
2165 .bind_conflict
= inet_csk_bind_conflict
,
2166 #ifdef CONFIG_COMPAT
2167 .compat_setsockopt
= compat_ip_setsockopt
,
2168 .compat_getsockopt
= compat_ip_getsockopt
,
2170 .mtu_reduced
= tcp_v4_mtu_reduced
,
2172 EXPORT_SYMBOL(ipv4_specific
);
2174 #ifdef CONFIG_TCP_MD5SIG
2175 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific
= {
2176 .md5_lookup
= tcp_v4_md5_lookup
,
2177 .calc_md5_hash
= tcp_v4_md5_hash_skb
,
2178 .md5_parse
= tcp_v4_parse_md5_keys
,
2182 /* NOTE: A lot of things set to zero explicitly by call to
2183 * sk_alloc() so need not be done here.
2185 static int tcp_v4_init_sock(struct sock
*sk
)
2187 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2190 icsk
->icsk_MMSRB
= 0;
2192 icsk
->icsk_af_ops
= &ipv4_specific
;
2194 #ifdef CONFIG_TCP_MD5SIG
2195 tcp_sk(sk
)->af_specific
= &tcp_sock_ipv4_specific
;
2201 void tcp_v4_destroy_sock(struct sock
*sk
)
2203 struct tcp_sock
*tp
= tcp_sk(sk
);
2205 tcp_clear_xmit_timers(sk
);
2207 tcp_cleanup_congestion_control(sk
);
2209 /* Cleanup up the write buffer. */
2210 tcp_write_queue_purge(sk
);
2212 /* Cleans up our, hopefully empty, out_of_order_queue. */
2213 __skb_queue_purge(&tp
->out_of_order_queue
);
2215 #ifdef CONFIG_TCP_MD5SIG
2216 /* Clean up the MD5 key list, if any */
2217 if (tp
->md5sig_info
) {
2218 tcp_clear_md5_list(sk
);
2219 kfree_rcu(tp
->md5sig_info
, rcu
);
2220 tp
->md5sig_info
= NULL
;
2224 #ifdef CONFIG_NET_DMA
2225 /* Cleans up our sk_async_wait_queue */
2226 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2229 /* Clean prequeue, it must be empty really */
2230 __skb_queue_purge(&tp
->ucopy
.prequeue
);
2232 /* Clean up a referenced TCP bind bucket. */
2233 if (inet_csk(sk
)->icsk_bind_hash
)
2236 BUG_ON(tp
->fastopen_rsk
!= NULL
);
2238 /* If socket is aborted during connect operation */
2239 tcp_free_fastopen_req(tp
);
2241 sk_sockets_allocated_dec(sk
);
2242 sock_release_memcg(sk
);
2244 EXPORT_SYMBOL(tcp_v4_destroy_sock
);
2246 void tcp_v4_handle_retrans_time_by_uid(struct uid_err uid_e
)
2248 unsigned int bucket
;
2249 uid_t skuid
= (uid_t
)(uid_e
.appuid
);
2250 struct inet_connection_sock
*icsk
= NULL
;//inet_csk(sk);
2253 for (bucket
= 0; bucket
< tcp_hashinfo
.ehash_mask
; bucket
++) {
2254 struct hlist_nulls_node
*node
;
2256 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, bucket
);
2259 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[bucket
].chain
) {
2261 if (sysctl_ip_dynaddr
&& sk
->sk_state
== TCP_SYN_SENT
)
2263 if (sock_flag(sk
, SOCK_DEAD
))
2267 if(SOCK_INODE(sk
->sk_socket
)->i_uid
!= skuid
)
2270 printk("[mmspb] tcp_v4_handle_retrans_time_by_uid socket uid(%d) match!",
2271 SOCK_INODE(sk
->sk_socket
)->i_uid
);
2277 spin_unlock_bh(lock
);
2282 // update sk time out value
2283 icsk
= inet_csk(sk
);
2284 printk("[mmspb] tcp_v4_handle_retrans_time_by_uid update timer\n");
2286 sk_reset_timer(sk
, &icsk
->icsk_retransmit_timer
, jiffies
+ 2);
2287 icsk
->icsk_rto
= sysctl_tcp_rto_min
* 30;
2288 icsk
->icsk_MMSRB
= 1;
2296 spin_unlock_bh(lock
);
2303 * tcp_v4_nuke_addr_by_uid - destroy all sockets of spcial uid
2305 void tcp_v4_reset_connections_by_uid(struct uid_err uid_e
)
2307 unsigned int bucket
;
2308 uid_t skuid
= (uid_t
)(uid_e
.appuid
);
2310 for (bucket
= 0; bucket
< tcp_hashinfo
.ehash_mask
; bucket
++) {
2311 struct hlist_nulls_node
*node
;
2313 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, bucket
);
2317 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[bucket
].chain
) {
2319 if (sysctl_ip_dynaddr
&& sk
->sk_state
== TCP_SYN_SENT
)
2321 if (sock_flag(sk
, SOCK_DEAD
))
2325 if(SOCK_INODE(sk
->sk_socket
)->i_uid
!= skuid
)
2328 printk(KERN_INFO
"SIOCKILLSOCK socket uid(%d) match!",
2329 SOCK_INODE(sk
->sk_socket
)->i_uid
);
2335 spin_unlock_bh(lock
);
2339 sk
->sk_err
= uid_e
.errNum
;
2340 printk(KERN_INFO
"SIOCKILLSOCK set sk err == %d!! \n", sk
->sk_err
);
2341 sk
->sk_error_report(sk
);
2350 spin_unlock_bh(lock
);
2355 #ifdef CONFIG_PROC_FS
2356 /* Proc filesystem TCP sock list dumping. */
2358 static inline struct inet_timewait_sock
*tw_head(struct hlist_nulls_head
*head
)
2360 return hlist_nulls_empty(head
) ? NULL
:
2361 list_entry(head
->first
, struct inet_timewait_sock
, tw_node
);
2364 static inline struct inet_timewait_sock
*tw_next(struct inet_timewait_sock
*tw
)
2366 return !is_a_nulls(tw
->tw_node
.next
) ?
2367 hlist_nulls_entry(tw
->tw_node
.next
, typeof(*tw
), tw_node
) : NULL
;
2371 * Get next listener socket follow cur. If cur is NULL, get first socket
2372 * starting from bucket given in st->bucket; when st->bucket is zero the
2373 * very first socket in the hash table is returned.
2375 static void *listening_get_next(struct seq_file
*seq
, void *cur
)
2377 struct inet_connection_sock
*icsk
;
2378 struct hlist_nulls_node
*node
;
2379 struct sock
*sk
= cur
;
2380 struct inet_listen_hashbucket
*ilb
;
2381 struct tcp_iter_state
*st
= seq
->private;
2382 struct net
*net
= seq_file_net(seq
);
2385 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2386 spin_lock_bh(&ilb
->lock
);
2387 sk
= sk_nulls_head(&ilb
->head
);
2391 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2395 if (st
->state
== TCP_SEQ_STATE_OPENREQ
) {
2396 struct request_sock
*req
= cur
;
2398 icsk
= inet_csk(st
->syn_wait_sk
);
2402 if (req
->rsk_ops
->family
== st
->family
) {
2408 if (++st
->sbucket
>= icsk
->icsk_accept_queue
.listen_opt
->nr_table_entries
)
2411 req
= icsk
->icsk_accept_queue
.listen_opt
->syn_table
[st
->sbucket
];
2413 sk
= sk_nulls_next(st
->syn_wait_sk
);
2414 st
->state
= TCP_SEQ_STATE_LISTENING
;
2415 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2417 icsk
= inet_csk(sk
);
2418 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2419 if (reqsk_queue_len(&icsk
->icsk_accept_queue
))
2421 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2422 sk
= sk_nulls_next(sk
);
2425 sk_nulls_for_each_from(sk
, node
) {
2426 if (!net_eq(sock_net(sk
), net
))
2428 if (sk
->sk_family
== st
->family
) {
2432 icsk
= inet_csk(sk
);
2433 read_lock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2434 if (reqsk_queue_len(&icsk
->icsk_accept_queue
)) {
2436 st
->uid
= sock_i_uid(sk
);
2437 st
->syn_wait_sk
= sk
;
2438 st
->state
= TCP_SEQ_STATE_OPENREQ
;
2442 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2444 spin_unlock_bh(&ilb
->lock
);
2446 if (++st
->bucket
< INET_LHTABLE_SIZE
) {
2447 ilb
= &tcp_hashinfo
.listening_hash
[st
->bucket
];
2448 spin_lock_bh(&ilb
->lock
);
2449 sk
= sk_nulls_head(&ilb
->head
);
2457 static void *listening_get_idx(struct seq_file
*seq
, loff_t
*pos
)
2459 struct tcp_iter_state
*st
= seq
->private;
2464 rc
= listening_get_next(seq
, NULL
);
2466 while (rc
&& *pos
) {
2467 rc
= listening_get_next(seq
, rc
);
2473 static inline bool empty_bucket(struct tcp_iter_state
*st
)
2475 return hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].chain
) &&
2476 hlist_nulls_empty(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2480 * Get first established socket starting from bucket given in st->bucket.
2481 * If st->bucket is zero, the very first socket in the hash is returned.
2483 static void *established_get_first(struct seq_file
*seq
)
2485 struct tcp_iter_state
*st
= seq
->private;
2486 struct net
*net
= seq_file_net(seq
);
2490 for (; st
->bucket
<= tcp_hashinfo
.ehash_mask
; ++st
->bucket
) {
2492 struct hlist_nulls_node
*node
;
2493 struct inet_timewait_sock
*tw
;
2494 spinlock_t
*lock
= inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
);
2496 /* Lockless fast path for the common case of empty buckets */
2497 if (empty_bucket(st
))
2501 sk_nulls_for_each(sk
, node
, &tcp_hashinfo
.ehash
[st
->bucket
].chain
) {
2502 if (sk
->sk_family
!= st
->family
||
2503 !net_eq(sock_net(sk
), net
)) {
2509 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2510 inet_twsk_for_each(tw
, node
,
2511 &tcp_hashinfo
.ehash
[st
->bucket
].twchain
) {
2512 if (tw
->tw_family
!= st
->family
||
2513 !net_eq(twsk_net(tw
), net
)) {
2519 spin_unlock_bh(lock
);
2520 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2526 static void *established_get_next(struct seq_file
*seq
, void *cur
)
2528 struct sock
*sk
= cur
;
2529 struct inet_timewait_sock
*tw
;
2530 struct hlist_nulls_node
*node
;
2531 struct tcp_iter_state
*st
= seq
->private;
2532 struct net
*net
= seq_file_net(seq
);
2537 if (st
->state
== TCP_SEQ_STATE_TIME_WAIT
) {
2541 while (tw
&& (tw
->tw_family
!= st
->family
|| !net_eq(twsk_net(tw
), net
))) {
2548 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2549 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2551 /* Look for next non empty bucket */
2553 while (++st
->bucket
<= tcp_hashinfo
.ehash_mask
&&
2556 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2559 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2560 sk
= sk_nulls_head(&tcp_hashinfo
.ehash
[st
->bucket
].chain
);
2562 sk
= sk_nulls_next(sk
);
2564 sk_nulls_for_each_from(sk
, node
) {
2565 if (sk
->sk_family
== st
->family
&& net_eq(sock_net(sk
), net
))
2569 st
->state
= TCP_SEQ_STATE_TIME_WAIT
;
2570 tw
= tw_head(&tcp_hashinfo
.ehash
[st
->bucket
].twchain
);
2578 static void *established_get_idx(struct seq_file
*seq
, loff_t pos
)
2580 struct tcp_iter_state
*st
= seq
->private;
2584 rc
= established_get_first(seq
);
2587 rc
= established_get_next(seq
, rc
);
2593 static void *tcp_get_idx(struct seq_file
*seq
, loff_t pos
)
2596 struct tcp_iter_state
*st
= seq
->private;
2598 st
->state
= TCP_SEQ_STATE_LISTENING
;
2599 rc
= listening_get_idx(seq
, &pos
);
2602 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2603 rc
= established_get_idx(seq
, pos
);
2609 static void *tcp_seek_last_pos(struct seq_file
*seq
)
2611 struct tcp_iter_state
*st
= seq
->private;
2612 int offset
= st
->offset
;
2613 int orig_num
= st
->num
;
2616 switch (st
->state
) {
2617 case TCP_SEQ_STATE_OPENREQ
:
2618 case TCP_SEQ_STATE_LISTENING
:
2619 if (st
->bucket
>= INET_LHTABLE_SIZE
)
2621 st
->state
= TCP_SEQ_STATE_LISTENING
;
2622 rc
= listening_get_next(seq
, NULL
);
2623 while (offset
-- && rc
)
2624 rc
= listening_get_next(seq
, rc
);
2629 case TCP_SEQ_STATE_ESTABLISHED
:
2630 case TCP_SEQ_STATE_TIME_WAIT
:
2631 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2632 if (st
->bucket
> tcp_hashinfo
.ehash_mask
)
2634 rc
= established_get_first(seq
);
2635 while (offset
-- && rc
)
2636 rc
= established_get_next(seq
, rc
);
2644 static void *tcp_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2646 struct tcp_iter_state
*st
= seq
->private;
2649 if (*pos
&& *pos
== st
->last_pos
) {
2650 rc
= tcp_seek_last_pos(seq
);
2655 st
->state
= TCP_SEQ_STATE_LISTENING
;
2659 rc
= *pos
? tcp_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2662 st
->last_pos
= *pos
;
2666 static void *tcp_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2668 struct tcp_iter_state
*st
= seq
->private;
2671 if (v
== SEQ_START_TOKEN
) {
2672 rc
= tcp_get_idx(seq
, 0);
2676 switch (st
->state
) {
2677 case TCP_SEQ_STATE_OPENREQ
:
2678 case TCP_SEQ_STATE_LISTENING
:
2679 rc
= listening_get_next(seq
, v
);
2681 st
->state
= TCP_SEQ_STATE_ESTABLISHED
;
2684 rc
= established_get_first(seq
);
2687 case TCP_SEQ_STATE_ESTABLISHED
:
2688 case TCP_SEQ_STATE_TIME_WAIT
:
2689 rc
= established_get_next(seq
, v
);
2694 st
->last_pos
= *pos
;
2698 static void tcp_seq_stop(struct seq_file
*seq
, void *v
)
2700 struct tcp_iter_state
*st
= seq
->private;
2702 switch (st
->state
) {
2703 case TCP_SEQ_STATE_OPENREQ
:
2705 struct inet_connection_sock
*icsk
= inet_csk(st
->syn_wait_sk
);
2706 read_unlock_bh(&icsk
->icsk_accept_queue
.syn_wait_lock
);
2708 case TCP_SEQ_STATE_LISTENING
:
2709 if (v
!= SEQ_START_TOKEN
)
2710 spin_unlock_bh(&tcp_hashinfo
.listening_hash
[st
->bucket
].lock
);
2712 case TCP_SEQ_STATE_TIME_WAIT
:
2713 case TCP_SEQ_STATE_ESTABLISHED
:
2715 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo
, st
->bucket
));
2720 int tcp_seq_open(struct inode
*inode
, struct file
*file
)
2722 struct tcp_seq_afinfo
*afinfo
= PDE_DATA(inode
);
2723 struct tcp_iter_state
*s
;
2726 err
= seq_open_net(inode
, file
, &afinfo
->seq_ops
,
2727 sizeof(struct tcp_iter_state
));
2731 s
= ((struct seq_file
*)file
->private_data
)->private;
2732 s
->family
= afinfo
->family
;
2736 EXPORT_SYMBOL(tcp_seq_open
);
2738 int tcp_proc_register(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2741 struct proc_dir_entry
*p
;
2743 afinfo
->seq_ops
.start
= tcp_seq_start
;
2744 afinfo
->seq_ops
.next
= tcp_seq_next
;
2745 afinfo
->seq_ops
.stop
= tcp_seq_stop
;
2747 p
= proc_create_data(afinfo
->name
, S_IRUGO
, net
->proc_net
,
2748 afinfo
->seq_fops
, afinfo
);
2753 EXPORT_SYMBOL(tcp_proc_register
);
2755 void tcp_proc_unregister(struct net
*net
, struct tcp_seq_afinfo
*afinfo
)
2757 remove_proc_entry(afinfo
->name
, net
->proc_net
);
2759 EXPORT_SYMBOL(tcp_proc_unregister
);
2761 static void get_openreq4(const struct sock
*sk
, const struct request_sock
*req
,
2762 struct seq_file
*f
, int i
, kuid_t uid
, int *len
)
2764 const struct inet_request_sock
*ireq
= inet_rsk(req
);
2765 long delta
= req
->expires
- jiffies
;
2767 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2768 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
2771 ntohs(inet_sk(sk
)->inet_sport
),
2773 ntohs(ireq
->rmt_port
),
2775 0, 0, /* could print option size, but that is af dependent. */
2776 1, /* timers active (only the expire timer) */
2777 jiffies_delta_to_clock_t(delta
),
2779 from_kuid_munged(seq_user_ns(f
), uid
),
2780 0, /* non standard timer */
2781 0, /* open_requests have no inode */
2782 atomic_read(&sk
->sk_refcnt
),
2787 static void get_tcp4_sock(struct sock
*sk
, struct seq_file
*f
, int i
, int *len
)
2790 unsigned long timer_expires
;
2791 const struct tcp_sock
*tp
= tcp_sk(sk
);
2792 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2793 const struct inet_sock
*inet
= inet_sk(sk
);
2794 struct fastopen_queue
*fastopenq
= icsk
->icsk_accept_queue
.fastopenq
;
2795 __be32 dest
= inet
->inet_daddr
;
2796 __be32 src
= inet
->inet_rcv_saddr
;
2797 __u16 destp
= ntohs(inet
->inet_dport
);
2798 __u16 srcp
= ntohs(inet
->inet_sport
);
2801 if (icsk
->icsk_pending
== ICSK_TIME_RETRANS
||
2802 icsk
->icsk_pending
== ICSK_TIME_EARLY_RETRANS
||
2803 icsk
->icsk_pending
== ICSK_TIME_LOSS_PROBE
) {
2805 timer_expires
= icsk
->icsk_timeout
;
2806 } else if (icsk
->icsk_pending
== ICSK_TIME_PROBE0
) {
2808 timer_expires
= icsk
->icsk_timeout
;
2809 } else if (timer_pending(&sk
->sk_timer
)) {
2811 timer_expires
= sk
->sk_timer
.expires
;
2814 timer_expires
= jiffies
;
2817 if (sk
->sk_state
== TCP_LISTEN
)
2818 rx_queue
= sk
->sk_ack_backlog
;
2821 * because we dont lock socket, we might find a transient negative value
2823 rx_queue
= max_t(int, tp
->rcv_nxt
- tp
->copied_seq
, 0);
2825 seq_printf(f
, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2826 "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n",
2827 i
, src
, srcp
, dest
, destp
, sk
->sk_state
,
2828 tp
->write_seq
- tp
->snd_una
,
2831 jiffies_delta_to_clock_t(timer_expires
- jiffies
),
2832 icsk
->icsk_retransmits
,
2833 from_kuid_munged(seq_user_ns(f
), sock_i_uid(sk
)),
2834 icsk
->icsk_probes_out
,
2836 atomic_read(&sk
->sk_refcnt
), sk
,
2837 jiffies_to_clock_t(icsk
->icsk_rto
),
2838 jiffies_to_clock_t(icsk
->icsk_ack
.ato
),
2839 (icsk
->icsk_ack
.quick
<< 1) | icsk
->icsk_ack
.pingpong
,
2841 sk
->sk_state
== TCP_LISTEN
?
2842 (fastopenq
? fastopenq
->max_qlen
: 0) :
2843 (tcp_in_initial_slowstart(tp
) ? -1 : tp
->snd_ssthresh
),
2847 static void get_timewait4_sock(const struct inet_timewait_sock
*tw
,
2848 struct seq_file
*f
, int i
, int *len
)
2852 long delta
= tw
->tw_ttd
- jiffies
;
2854 dest
= tw
->tw_daddr
;
2855 src
= tw
->tw_rcv_saddr
;
2856 destp
= ntohs(tw
->tw_dport
);
2857 srcp
= ntohs(tw
->tw_sport
);
2859 seq_printf(f
, "%4d: %08X:%04X %08X:%04X"
2860 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
2861 i
, src
, srcp
, dest
, destp
, tw
->tw_substate
, 0, 0,
2862 3, jiffies_delta_to_clock_t(delta
), 0, 0, 0, 0,
2863 atomic_read(&tw
->tw_refcnt
), tw
, len
);
2868 static int tcp4_seq_show(struct seq_file
*seq
, void *v
)
2870 struct tcp_iter_state
*st
;
2873 if (v
== SEQ_START_TOKEN
) {
2874 seq_printf(seq
, "%-*s\n", TMPSZ
- 1,
2875 " sl local_address rem_address st tx_queue "
2876 "rx_queue tr tm->when retrnsmt uid timeout "
2882 switch (st
->state
) {
2883 case TCP_SEQ_STATE_LISTENING
:
2884 case TCP_SEQ_STATE_ESTABLISHED
:
2885 get_tcp4_sock(v
, seq
, st
->num
, &len
);
2887 case TCP_SEQ_STATE_OPENREQ
:
2888 get_openreq4(st
->syn_wait_sk
, v
, seq
, st
->num
, st
->uid
, &len
);
2890 case TCP_SEQ_STATE_TIME_WAIT
:
2891 get_timewait4_sock(v
, seq
, st
->num
, &len
);
2894 seq_printf(seq
, "%*s\n", TMPSZ
- 1 - len
, "");
2899 static const struct file_operations tcp_afinfo_seq_fops
= {
2900 .owner
= THIS_MODULE
,
2901 .open
= tcp_seq_open
,
2903 .llseek
= seq_lseek
,
2904 .release
= seq_release_net
2907 static struct tcp_seq_afinfo tcp4_seq_afinfo
= {
2910 .seq_fops
= &tcp_afinfo_seq_fops
,
2912 .show
= tcp4_seq_show
,
2916 static int __net_init
tcp4_proc_init_net(struct net
*net
)
2918 return tcp_proc_register(net
, &tcp4_seq_afinfo
);
2921 static void __net_exit
tcp4_proc_exit_net(struct net
*net
)
2923 tcp_proc_unregister(net
, &tcp4_seq_afinfo
);
2926 static struct pernet_operations tcp4_net_ops
= {
2927 .init
= tcp4_proc_init_net
,
2928 .exit
= tcp4_proc_exit_net
,
2931 int __init
tcp4_proc_init(void)
2933 return register_pernet_subsys(&tcp4_net_ops
);
2936 void tcp4_proc_exit(void)
2938 unregister_pernet_subsys(&tcp4_net_ops
);
2940 #endif /* CONFIG_PROC_FS */
2942 struct sk_buff
**tcp4_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
2944 const struct iphdr
*iph
= skb_gro_network_header(skb
);
2948 switch (skb
->ip_summed
) {
2949 case CHECKSUM_COMPLETE
:
2950 if (!tcp_v4_check(skb_gro_len(skb
), iph
->saddr
, iph
->daddr
,
2952 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2956 NAPI_GRO_CB(skb
)->flush
= 1;
2960 wsum
= csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
2961 skb_gro_len(skb
), IPPROTO_TCP
, 0);
2962 sum
= csum_fold(skb_checksum(skb
,
2963 skb_gro_offset(skb
),
2969 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2973 return tcp_gro_receive(head
, skb
);
2976 int tcp4_gro_complete(struct sk_buff
*skb
)
2978 const struct iphdr
*iph
= ip_hdr(skb
);
2979 struct tcphdr
*th
= tcp_hdr(skb
);
2981 th
->check
= ~tcp_v4_check(skb
->len
- skb_transport_offset(skb
),
2982 iph
->saddr
, iph
->daddr
, 0);
2983 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
2985 return tcp_gro_complete(skb
);
2988 struct proto tcp_prot
= {
2990 .owner
= THIS_MODULE
,
2992 .connect
= tcp_v4_connect
,
2993 .disconnect
= tcp_disconnect
,
2994 .accept
= inet_csk_accept
,
2996 .init
= tcp_v4_init_sock
,
2997 .destroy
= tcp_v4_destroy_sock
,
2998 .shutdown
= tcp_shutdown
,
2999 .setsockopt
= tcp_setsockopt
,
3000 .getsockopt
= tcp_getsockopt
,
3001 .recvmsg
= tcp_recvmsg
,
3002 .sendmsg
= tcp_sendmsg
,
3003 .sendpage
= tcp_sendpage
,
3004 .backlog_rcv
= tcp_v4_do_rcv
,
3005 .release_cb
= tcp_release_cb
,
3007 .unhash
= inet_unhash
,
3008 .get_port
= inet_csk_get_port
,
3009 .enter_memory_pressure
= tcp_enter_memory_pressure
,
3010 .sockets_allocated
= &tcp_sockets_allocated
,
3011 .orphan_count
= &tcp_orphan_count
,
3012 .memory_allocated
= &tcp_memory_allocated
,
3013 .memory_pressure
= &tcp_memory_pressure
,
3014 .sysctl_wmem
= sysctl_tcp_wmem
,
3015 .sysctl_rmem
= sysctl_tcp_rmem
,
3016 .max_header
= MAX_TCP_HEADER
,
3017 .obj_size
= sizeof(struct tcp_sock
),
3018 .slab_flags
= SLAB_DESTROY_BY_RCU
,
3019 .twsk_prot
= &tcp_timewait_sock_ops
,
3020 .rsk_prot
= &tcp_request_sock_ops
,
3021 .h
.hashinfo
= &tcp_hashinfo
,
3022 .no_autobind
= true,
3023 #ifdef CONFIG_COMPAT
3024 .compat_setsockopt
= compat_tcp_setsockopt
,
3025 .compat_getsockopt
= compat_tcp_getsockopt
,
3027 #ifdef CONFIG_MEMCG_KMEM
3028 .init_cgroup
= tcp_init_cgroup
,
3029 .destroy_cgroup
= tcp_destroy_cgroup
,
3030 .proto_cgroup
= tcp_proto_cgroup
,
3033 EXPORT_SYMBOL(tcp_prot
);
3035 static void __net_exit
tcp_sk_exit(struct net
*net
)
3039 for_each_possible_cpu(cpu
)
3040 inet_ctl_sock_destroy(*per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
));
3041 free_percpu(net
->ipv4
.tcp_sk
);
3044 static int __net_init
tcp_sk_init(struct net
*net
)
3048 net
->ipv4
.tcp_sk
= alloc_percpu(struct sock
*);
3049 if (!net
->ipv4
.tcp_sk
)
3052 for_each_possible_cpu(cpu
) {
3055 res
= inet_ctl_sock_create(&sk
, PF_INET
, SOCK_RAW
,
3059 *per_cpu_ptr(net
->ipv4
.tcp_sk
, cpu
) = sk
;
3061 net
->ipv4
.sysctl_tcp_ecn
= 2;
3070 static void __net_exit
tcp_sk_exit_batch(struct list_head
*net_exit_list
)
3072 inet_twsk_purge(&tcp_hashinfo
, &tcp_death_row
, AF_INET
);
3075 static struct pernet_operations __net_initdata tcp_sk_ops
= {
3076 .init
= tcp_sk_init
,
3077 .exit
= tcp_sk_exit
,
3078 .exit_batch
= tcp_sk_exit_batch
,
3081 void __init
tcp_v4_init(void)
3083 inet_hashinfo_init(&tcp_hashinfo
);
3084 if (register_pernet_subsys(&tcp_sk_ops
))
3085 panic("Failed to create the TCP control socket.\n");