3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
26 #include <linux/bottom_half.h>
27 #include <linux/module.h>
28 #include <linux/errno.h>
29 #include <linux/types.h>
30 #include <linux/socket.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/jiffies.h>
35 #include <linux/in6.h>
36 #include <linux/netdevice.h>
37 #include <linux/init.h>
38 #include <linux/jhash.h>
39 #include <linux/ipsec.h>
40 #include <linux/times.h>
41 #include <linux/slab.h>
42 #include <linux/uaccess.h>
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
48 #include <net/ndisc.h>
49 #include <net/inet6_hashtables.h>
50 #include <net/inet6_connection_sock.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/ip6_checksum.h>
56 #include <net/inet_ecn.h>
57 #include <net/protocol.h>
60 #include <net/dsfield.h>
61 #include <net/timewait_sock.h>
62 #include <net/inet_common.h>
63 #include <net/secure_seq.h>
64 #include <net/tcp_memcontrol.h>
65 #include <net/busy_poll.h>
67 #include <linux/proc_fs.h>
68 #include <linux/seq_file.h>
70 #include <linux/crypto.h>
71 #include <linux/scatterlist.h>
73 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
74 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
75 struct request_sock *req);
77 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79 static const struct inet_connection_sock_af_ops ipv6_mapped;
80 static const struct inet_connection_sock_af_ops ipv6_specific;
81 #ifdef CONFIG_TCP_MD5SIG
82 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
83 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
85 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
86 const struct in6_addr *addr)
92 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
94 struct dst_entry *dst = skb_dst(skb);
96 if (dst && dst_hold_safe(dst)) {
97 const struct rt6_info *rt = (const struct rt6_info *)dst;
100 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
101 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
105 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
107 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
108 ipv6_hdr(skb)->saddr.s6_addr32,
110 tcp_hdr(skb)->source);
113 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
116 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
117 struct inet_sock *inet = inet_sk(sk);
118 struct inet_connection_sock *icsk = inet_csk(sk);
119 struct ipv6_pinfo *np = inet6_sk(sk);
120 struct tcp_sock *tp = tcp_sk(sk);
121 struct in6_addr *saddr = NULL, *final_p, final;
122 struct ipv6_txoptions *opt;
124 struct dst_entry *dst;
128 if (addr_len < SIN6_LEN_RFC2133)
131 if (usin->sin6_family != AF_INET6)
132 return -EAFNOSUPPORT;
134 memset(&fl6, 0, sizeof(fl6));
137 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
138 IP6_ECN_flow_init(fl6.flowlabel);
139 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
140 struct ip6_flowlabel *flowlabel;
141 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
144 fl6_sock_release(flowlabel);
149 * connect() to INADDR_ANY means loopback (BSD'ism).
152 if (ipv6_addr_any(&usin->sin6_addr))
153 usin->sin6_addr.s6_addr[15] = 0x1;
155 addr_type = ipv6_addr_type(&usin->sin6_addr);
157 if (addr_type & IPV6_ADDR_MULTICAST)
160 if (addr_type&IPV6_ADDR_LINKLOCAL) {
161 if (addr_len >= sizeof(struct sockaddr_in6) &&
162 usin->sin6_scope_id) {
163 /* If interface is set while binding, indices
166 if (sk->sk_bound_dev_if &&
167 sk->sk_bound_dev_if != usin->sin6_scope_id)
170 sk->sk_bound_dev_if = usin->sin6_scope_id;
173 /* Connect to link-local address requires an interface */
174 if (!sk->sk_bound_dev_if)
178 if (tp->rx_opt.ts_recent_stamp &&
179 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
180 tp->rx_opt.ts_recent = 0;
181 tp->rx_opt.ts_recent_stamp = 0;
185 sk->sk_v6_daddr = usin->sin6_addr;
186 np->flow_label = fl6.flowlabel;
192 if (addr_type == IPV6_ADDR_MAPPED) {
193 u32 exthdrlen = icsk->icsk_ext_hdr_len;
194 struct sockaddr_in sin;
196 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
198 if (__ipv6_only_sock(sk))
201 sin.sin_family = AF_INET;
202 sin.sin_port = usin->sin6_port;
203 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
205 icsk->icsk_af_ops = &ipv6_mapped;
206 sk->sk_backlog_rcv = tcp_v4_do_rcv;
207 #ifdef CONFIG_TCP_MD5SIG
208 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
211 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
214 icsk->icsk_ext_hdr_len = exthdrlen;
215 icsk->icsk_af_ops = &ipv6_specific;
216 sk->sk_backlog_rcv = tcp_v6_do_rcv;
217 #ifdef CONFIG_TCP_MD5SIG
218 tp->af_specific = &tcp_sock_ipv6_specific;
222 np->saddr = sk->sk_v6_rcv_saddr;
227 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
228 saddr = &sk->sk_v6_rcv_saddr;
230 fl6.flowi6_proto = IPPROTO_TCP;
231 fl6.daddr = sk->sk_v6_daddr;
232 fl6.saddr = saddr ? *saddr : np->saddr;
233 fl6.flowi6_oif = sk->sk_bound_dev_if;
234 fl6.flowi6_mark = sk->sk_mark;
235 fl6.fl6_dport = usin->sin6_port;
236 fl6.fl6_sport = inet->inet_sport;
238 opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
239 final_p = fl6_update_dst(&fl6, opt, &final);
241 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
243 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
251 sk->sk_v6_rcv_saddr = *saddr;
254 /* set the source address */
256 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
258 sk->sk_gso_type = SKB_GSO_TCPV6;
259 ip6_dst_store(sk, dst, NULL, NULL);
261 if (tcp_death_row.sysctl_tw_recycle &&
262 !tp->rx_opt.ts_recent_stamp &&
263 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
264 tcp_fetch_timewait_stamp(sk, dst);
266 icsk->icsk_ext_hdr_len = 0;
268 icsk->icsk_ext_hdr_len = opt->opt_flen +
271 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
273 inet->inet_dport = usin->sin6_port;
275 tcp_set_state(sk, TCP_SYN_SENT);
276 err = inet6_hash_connect(&tcp_death_row, sk);
282 if (!tp->write_seq && likely(!tp->repair))
283 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
284 sk->sk_v6_daddr.s6_addr32,
288 err = tcp_connect(sk);
295 tcp_set_state(sk, TCP_CLOSE);
298 inet->inet_dport = 0;
299 sk->sk_route_caps = 0;
303 static void tcp_v6_mtu_reduced(struct sock *sk)
305 struct dst_entry *dst;
307 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
310 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
314 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
315 tcp_sync_mss(sk, dst_mtu(dst));
316 tcp_simple_retransmit(sk);
320 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
321 u8 type, u8 code, int offset, __be32 info)
323 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
324 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
325 struct net *net = dev_net(skb->dev);
326 struct request_sock *fastopen;
327 struct ipv6_pinfo *np;
334 sk = __inet6_lookup_established(net, &tcp_hashinfo,
335 &hdr->daddr, th->dest,
336 &hdr->saddr, ntohs(th->source),
340 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
345 if (sk->sk_state == TCP_TIME_WAIT) {
346 inet_twsk_put(inet_twsk(sk));
349 seq = ntohl(th->seq);
350 fatal = icmpv6_err_convert(type, code, &err);
351 if (sk->sk_state == TCP_NEW_SYN_RECV)
352 return tcp_req_err(sk, seq, fatal);
355 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
356 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
358 if (sk->sk_state == TCP_CLOSE)
361 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
362 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
367 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
368 fastopen = tp->fastopen_rsk;
369 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
370 if (sk->sk_state != TCP_LISTEN &&
371 !between(seq, snd_una, tp->snd_nxt)) {
372 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
378 if (type == NDISC_REDIRECT) {
379 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
382 dst->ops->redirect(dst, sk, skb);
386 if (type == ICMPV6_PKT_TOOBIG) {
387 /* We are not interested in TCP_LISTEN and open_requests
388 * (SYN-ACKs send out by Linux are always <576bytes so
389 * they should go through unfragmented).
391 if (sk->sk_state == TCP_LISTEN)
394 if (!ip6_sk_accept_pmtu(sk))
397 tp->mtu_info = ntohl(info);
398 if (!sock_owned_by_user(sk))
399 tcp_v6_mtu_reduced(sk);
400 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
407 /* Might be for an request_sock */
408 switch (sk->sk_state) {
411 /* Only in fast or simultaneous open. If a fast open socket is
412 * is already accepted it is treated as a connected one below.
414 if (fastopen && !fastopen->sk)
417 if (!sock_owned_by_user(sk)) {
419 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
423 sk->sk_err_soft = err;
427 if (!sock_owned_by_user(sk) && np->recverr) {
429 sk->sk_error_report(sk);
431 sk->sk_err_soft = err;
439 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
441 struct request_sock *req,
442 struct tcp_fastopen_cookie *foc,
445 struct inet_request_sock *ireq = inet_rsk(req);
446 struct ipv6_pinfo *np = inet6_sk(sk);
447 struct flowi6 *fl6 = &fl->u.ip6;
451 /* First, grab a route. */
452 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
453 IPPROTO_TCP)) == NULL)
456 skb = tcp_make_synack(sk, dst, req, foc, attach_req);
459 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
460 &ireq->ir_v6_rmt_addr);
462 fl6->daddr = ireq->ir_v6_rmt_addr;
463 if (np->repflow && ireq->pktopts)
464 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
467 err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt),
470 err = net_xmit_eval(err);
478 static void tcp_v6_reqsk_destructor(struct request_sock *req)
480 kfree_skb(inet_rsk(req)->pktopts);
483 #ifdef CONFIG_TCP_MD5SIG
484 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
485 const struct in6_addr *addr)
487 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
490 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
491 const struct sock *addr_sk)
493 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
496 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
499 struct tcp_md5sig cmd;
500 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
502 if (optlen < sizeof(cmd))
505 if (copy_from_user(&cmd, optval, sizeof(cmd)))
508 if (sin6->sin6_family != AF_INET6)
511 if (!cmd.tcpm_keylen) {
512 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
513 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
515 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
519 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
522 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
523 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
524 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
526 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
527 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
530 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
531 const struct in6_addr *daddr,
532 const struct in6_addr *saddr, int nbytes)
534 struct tcp6_pseudohdr *bp;
535 struct scatterlist sg;
537 bp = &hp->md5_blk.ip6;
538 /* 1. TCP pseudo-header (RFC2460) */
541 bp->protocol = cpu_to_be32(IPPROTO_TCP);
542 bp->len = cpu_to_be32(nbytes);
544 sg_init_one(&sg, bp, sizeof(*bp));
545 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
548 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
549 const struct in6_addr *daddr, struct in6_addr *saddr,
550 const struct tcphdr *th)
552 struct tcp_md5sig_pool *hp;
553 struct hash_desc *desc;
555 hp = tcp_get_md5sig_pool();
557 goto clear_hash_noput;
558 desc = &hp->md5_desc;
560 if (crypto_hash_init(desc))
562 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
564 if (tcp_md5_hash_header(hp, th))
566 if (tcp_md5_hash_key(hp, key))
568 if (crypto_hash_final(desc, md5_hash))
571 tcp_put_md5sig_pool();
575 tcp_put_md5sig_pool();
577 memset(md5_hash, 0, 16);
581 static int tcp_v6_md5_hash_skb(char *md5_hash,
582 const struct tcp_md5sig_key *key,
583 const struct sock *sk,
584 const struct sk_buff *skb)
586 const struct in6_addr *saddr, *daddr;
587 struct tcp_md5sig_pool *hp;
588 struct hash_desc *desc;
589 const struct tcphdr *th = tcp_hdr(skb);
591 if (sk) { /* valid for establish/request sockets */
592 saddr = &sk->sk_v6_rcv_saddr;
593 daddr = &sk->sk_v6_daddr;
595 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
596 saddr = &ip6h->saddr;
597 daddr = &ip6h->daddr;
600 hp = tcp_get_md5sig_pool();
602 goto clear_hash_noput;
603 desc = &hp->md5_desc;
605 if (crypto_hash_init(desc))
608 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
610 if (tcp_md5_hash_header(hp, th))
612 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
614 if (tcp_md5_hash_key(hp, key))
616 if (crypto_hash_final(desc, md5_hash))
619 tcp_put_md5sig_pool();
623 tcp_put_md5sig_pool();
625 memset(md5_hash, 0, 16);
631 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
632 const struct sk_buff *skb)
634 #ifdef CONFIG_TCP_MD5SIG
635 const __u8 *hash_location = NULL;
636 struct tcp_md5sig_key *hash_expected;
637 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
638 const struct tcphdr *th = tcp_hdr(skb);
642 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
643 hash_location = tcp_parse_md5sig_option(th);
645 /* We've parsed the options - do we have a hash? */
646 if (!hash_expected && !hash_location)
649 if (hash_expected && !hash_location) {
650 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
654 if (!hash_expected && hash_location) {
655 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
659 /* check the signature */
660 genhash = tcp_v6_md5_hash_skb(newhash,
664 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
665 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
666 genhash ? "failed" : "mismatch",
667 &ip6h->saddr, ntohs(th->source),
668 &ip6h->daddr, ntohs(th->dest));
675 static void tcp_v6_init_req(struct request_sock *req,
676 const struct sock *sk_listener,
679 struct inet_request_sock *ireq = inet_rsk(req);
680 const struct ipv6_pinfo *np = inet6_sk(sk_listener);
682 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
683 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
685 /* So that link locals have meaning */
686 if (!sk_listener->sk_bound_dev_if &&
687 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
688 ireq->ir_iif = tcp_v6_iif(skb);
690 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
691 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
692 np->rxopt.bits.rxinfo ||
693 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
694 np->rxopt.bits.rxohlim || np->repflow)) {
695 atomic_inc(&skb->users);
700 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
702 const struct request_sock *req,
707 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
710 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
712 .obj_size = sizeof(struct tcp6_request_sock),
713 .rtx_syn_ack = tcp_rtx_synack,
714 .send_ack = tcp_v6_reqsk_send_ack,
715 .destructor = tcp_v6_reqsk_destructor,
716 .send_reset = tcp_v6_send_reset,
717 .syn_ack_timeout = tcp_syn_ack_timeout,
720 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
721 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
722 sizeof(struct ipv6hdr),
723 #ifdef CONFIG_TCP_MD5SIG
724 .req_md5_lookup = tcp_v6_md5_lookup,
725 .calc_md5_hash = tcp_v6_md5_hash_skb,
727 .init_req = tcp_v6_init_req,
728 #ifdef CONFIG_SYN_COOKIES
729 .cookie_init_seq = cookie_v6_init_sequence,
731 .route_req = tcp_v6_route_req,
732 .init_seq = tcp_v6_init_sequence,
733 .send_synack = tcp_v6_send_synack,
736 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
737 u32 ack, u32 win, u32 tsval, u32 tsecr,
738 int oif, struct tcp_md5sig_key *key, int rst,
739 u8 tclass, u32 label)
741 const struct tcphdr *th = tcp_hdr(skb);
743 struct sk_buff *buff;
745 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
746 struct sock *ctl_sk = net->ipv6.tcp_sk;
747 unsigned int tot_len = sizeof(struct tcphdr);
748 struct dst_entry *dst;
752 tot_len += TCPOLEN_TSTAMP_ALIGNED;
753 #ifdef CONFIG_TCP_MD5SIG
755 tot_len += TCPOLEN_MD5SIG_ALIGNED;
758 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
763 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
765 t1 = (struct tcphdr *) skb_push(buff, tot_len);
766 skb_reset_transport_header(buff);
768 /* Swap the send and the receive. */
769 memset(t1, 0, sizeof(*t1));
770 t1->dest = th->source;
771 t1->source = th->dest;
772 t1->doff = tot_len / 4;
773 t1->seq = htonl(seq);
774 t1->ack_seq = htonl(ack);
775 t1->ack = !rst || !th->ack;
777 t1->window = htons(win);
779 topt = (__be32 *)(t1 + 1);
782 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
783 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
784 *topt++ = htonl(tsval);
785 *topt++ = htonl(tsecr);
788 #ifdef CONFIG_TCP_MD5SIG
790 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
791 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
792 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
793 &ipv6_hdr(skb)->saddr,
794 &ipv6_hdr(skb)->daddr, t1);
798 memset(&fl6, 0, sizeof(fl6));
799 fl6.daddr = ipv6_hdr(skb)->saddr;
800 fl6.saddr = ipv6_hdr(skb)->daddr;
801 fl6.flowlabel = label;
803 buff->ip_summed = CHECKSUM_PARTIAL;
806 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
808 fl6.flowi6_proto = IPPROTO_TCP;
809 if (rt6_need_strict(&fl6.daddr) && !oif)
810 fl6.flowi6_oif = tcp_v6_iif(skb);
812 fl6.flowi6_oif = oif;
813 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
814 fl6.fl6_dport = t1->dest;
815 fl6.fl6_sport = t1->source;
816 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
818 /* Pass a socket to ip6_dst_lookup either it is for RST
819 * Underlying function will use this to retrieve the network
822 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
824 skb_dst_set(buff, dst);
825 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
826 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
828 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
835 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
837 const struct tcphdr *th = tcp_hdr(skb);
838 u32 seq = 0, ack_seq = 0;
839 struct tcp_md5sig_key *key = NULL;
840 #ifdef CONFIG_TCP_MD5SIG
841 const __u8 *hash_location = NULL;
842 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
843 unsigned char newhash[16];
845 struct sock *sk1 = NULL;
852 /* If sk not NULL, it means we did a successful lookup and incoming
853 * route had to be correct. prequeue might have dropped our dst.
855 if (!sk && !ipv6_unicast_destination(skb))
858 #ifdef CONFIG_TCP_MD5SIG
859 hash_location = tcp_parse_md5sig_option(th);
860 if (!sk && hash_location) {
862 * active side is lost. Try to find listening socket through
863 * source port, and then find md5 key through listening socket.
864 * we are not loose security here:
865 * Incoming packet is checked with md5 hash with finding key,
866 * no RST generated if md5 hash doesn't match.
868 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
869 &tcp_hashinfo, &ipv6h->saddr,
870 th->source, &ipv6h->daddr,
871 ntohs(th->source), tcp_v6_iif(skb));
876 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
880 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
881 if (genhash || memcmp(hash_location, newhash, 16) != 0)
884 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
889 seq = ntohl(th->ack_seq);
891 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
894 oif = sk ? sk->sk_bound_dev_if : 0;
895 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
897 #ifdef CONFIG_TCP_MD5SIG
906 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
907 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
908 struct tcp_md5sig_key *key, u8 tclass,
911 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
915 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
917 struct inet_timewait_sock *tw = inet_twsk(sk);
918 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
920 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
921 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
922 tcp_time_stamp + tcptw->tw_ts_offset,
923 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
924 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
929 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
930 struct request_sock *req)
932 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
933 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
936 * The window field (SEG.WND) of every outgoing segment, with the
937 * exception of <SYN> segments, MUST be right-shifted by
938 * Rcv.Wind.Shift bits:
940 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
941 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
942 tcp_rsk(req)->rcv_nxt,
943 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
944 tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
945 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
950 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
952 #ifdef CONFIG_SYN_COOKIES
953 const struct tcphdr *th = tcp_hdr(skb);
956 sk = cookie_v6_check(sk, skb);
961 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
963 if (skb->protocol == htons(ETH_P_IP))
964 return tcp_v4_conn_request(sk, skb);
966 if (!ipv6_unicast_destination(skb))
969 return tcp_conn_request(&tcp6_request_sock_ops,
970 &tcp_request_sock_ipv6_ops, sk, skb);
973 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
974 return 0; /* don't send reset */
977 static void tcp_v6_restore_cb(struct sk_buff *skb)
979 /* We need to move header back to the beginning if xfrm6_policy_check()
980 * and tcp_v6_fill_cb() are going to be called again.
981 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
983 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
984 sizeof(struct inet6_skb_parm));
987 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
988 struct request_sock *req,
989 struct dst_entry *dst,
990 struct request_sock *req_unhash,
993 struct inet_request_sock *ireq;
994 struct ipv6_pinfo *newnp;
995 const struct ipv6_pinfo *np = inet6_sk(sk);
996 struct ipv6_txoptions *opt;
997 struct tcp6_sock *newtcp6sk;
998 struct inet_sock *newinet;
999 struct tcp_sock *newtp;
1001 #ifdef CONFIG_TCP_MD5SIG
1002 struct tcp_md5sig_key *key;
1006 if (skb->protocol == htons(ETH_P_IP)) {
1011 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1012 req_unhash, own_req);
1017 newtcp6sk = (struct tcp6_sock *)newsk;
1018 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1020 newinet = inet_sk(newsk);
1021 newnp = inet6_sk(newsk);
1022 newtp = tcp_sk(newsk);
1024 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1026 newnp->saddr = newsk->sk_v6_rcv_saddr;
1028 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1029 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1030 #ifdef CONFIG_TCP_MD5SIG
1031 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1034 newnp->ipv6_ac_list = NULL;
1035 newnp->ipv6_fl_list = NULL;
1036 newnp->pktoptions = NULL;
1038 newnp->mcast_oif = tcp_v6_iif(skb);
1039 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1040 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1042 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1045 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1046 * here, tcp_create_openreq_child now does this for us, see the comment in
1047 * that function for the gory details. -acme
1050 /* It is tricky place. Until this moment IPv4 tcp
1051 worked with IPv6 icsk.icsk_af_ops.
1054 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1059 ireq = inet_rsk(req);
1061 if (sk_acceptq_is_full(sk))
1065 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1070 newsk = tcp_create_openreq_child(sk, req, skb);
1075 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1076 * count here, tcp_create_openreq_child now does this for us, see the
1077 * comment in that function for the gory details. -acme
1080 newsk->sk_gso_type = SKB_GSO_TCPV6;
1081 ip6_dst_store(newsk, dst, NULL, NULL);
1082 inet6_sk_rx_dst_set(newsk, skb);
1084 newtcp6sk = (struct tcp6_sock *)newsk;
1085 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1087 newtp = tcp_sk(newsk);
1088 newinet = inet_sk(newsk);
1089 newnp = inet6_sk(newsk);
1091 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1093 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1094 newnp->saddr = ireq->ir_v6_loc_addr;
1095 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1096 newsk->sk_bound_dev_if = ireq->ir_iif;
1098 /* Now IPv6 options...
1100 First: no IPv4 options.
1102 newinet->inet_opt = NULL;
1103 newnp->ipv6_ac_list = NULL;
1104 newnp->ipv6_fl_list = NULL;
1107 newnp->rxopt.all = np->rxopt.all;
1109 newnp->pktoptions = NULL;
1111 newnp->mcast_oif = tcp_v6_iif(skb);
1112 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1113 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1115 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1117 /* Clone native IPv6 options from listening socket (if any)
1119 Yes, keeping reference count would be much more clever,
1120 but we make one more one thing there: reattach optmem
1123 opt = rcu_dereference(np->opt);
1125 opt = ipv6_dup_options(newsk, opt);
1126 RCU_INIT_POINTER(newnp->opt, opt);
1128 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1130 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1133 tcp_ca_openreq_child(newsk, dst);
1135 tcp_sync_mss(newsk, dst_mtu(dst));
1136 newtp->advmss = dst_metric_advmss(dst);
1137 if (tcp_sk(sk)->rx_opt.user_mss &&
1138 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1139 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1141 tcp_initialize_rcv_mss(newsk);
1143 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1144 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1146 #ifdef CONFIG_TCP_MD5SIG
1147 /* Copy over the MD5 key from the original socket */
1148 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1150 /* We're using one, so create a matching key
1151 * on the newsk structure. If we fail to get
1152 * memory, then we end up not copying the key
1155 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1156 AF_INET6, key->key, key->keylen,
1157 sk_gfp_atomic(sk, GFP_ATOMIC));
1161 if (__inet_inherit_port(sk, newsk) < 0) {
1162 inet_csk_prepare_forced_close(newsk);
1166 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1168 tcp_move_syn(newtp, req);
1170 /* Clone pktoptions received with SYN, if we own the req */
1171 if (ireq->pktopts) {
1172 newnp->pktoptions = skb_clone(ireq->pktopts,
1173 sk_gfp_atomic(sk, GFP_ATOMIC));
1174 consume_skb(ireq->pktopts);
1175 ireq->pktopts = NULL;
1176 if (newnp->pktoptions) {
1177 tcp_v6_restore_cb(newnp->pktoptions);
1178 skb_set_owner_r(newnp->pktoptions, newsk);
1186 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1190 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1194 /* The socket must have it's spinlock held when we get
1195 * here, unless it is a TCP_LISTEN socket.
1197 * We have a potential double-lock case here, so even when
1198 * doing backlog processing we use the BH locking scheme.
1199 * This is because we cannot sleep with the original spinlock
1202 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1204 struct ipv6_pinfo *np = inet6_sk(sk);
1205 struct tcp_sock *tp;
1206 struct sk_buff *opt_skb = NULL;
1208 /* Imagine: socket is IPv6. IPv4 packet arrives,
1209 goes to IPv4 receive handler and backlogged.
1210 From backlog it always goes here. Kerboom...
1211 Fortunately, tcp_rcv_established and rcv_established
1212 handle them correctly, but it is not case with
1213 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1216 if (skb->protocol == htons(ETH_P_IP))
1217 return tcp_v4_do_rcv(sk, skb);
1219 if (tcp_filter(sk, skb))
1223 * socket locking is here for SMP purposes as backlog rcv
1224 * is currently called with bh processing disabled.
1227 /* Do Stevens' IPV6_PKTOPTIONS.
1229 Yes, guys, it is the only place in our code, where we
1230 may make it not affecting IPv4.
1231 The rest of code is protocol independent,
1232 and I do not like idea to uglify IPv4.
1234 Actually, all the idea behind IPV6_PKTOPTIONS
1235 looks not very well thought. For now we latch
1236 options, received in the last packet, enqueued
1237 by tcp. Feel free to propose better solution.
1241 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1243 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1244 struct dst_entry *dst = sk->sk_rx_dst;
1246 sock_rps_save_rxhash(sk, skb);
1247 sk_mark_napi_id(sk, skb);
1249 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1250 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1252 sk->sk_rx_dst = NULL;
1256 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1258 goto ipv6_pktoptions;
1262 if (tcp_checksum_complete(skb))
1265 if (sk->sk_state == TCP_LISTEN) {
1266 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1272 sock_rps_save_rxhash(nsk, skb);
1273 sk_mark_napi_id(nsk, skb);
1274 if (tcp_child_process(sk, nsk, skb))
1277 __kfree_skb(opt_skb);
1281 sock_rps_save_rxhash(sk, skb);
1283 if (tcp_rcv_state_process(sk, skb))
1286 goto ipv6_pktoptions;
1290 tcp_v6_send_reset(sk, skb);
1293 __kfree_skb(opt_skb);
1297 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1298 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1303 /* Do you ask, what is it?
1305 1. skb was enqueued by tcp.
1306 2. skb is added to tail of read queue, rather than out of order.
1307 3. socket is not in passive state.
1308 4. Finally, it really contains options, which user wants to receive.
1311 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1312 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1313 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1314 np->mcast_oif = tcp_v6_iif(opt_skb);
1315 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1316 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1317 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1318 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1320 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1321 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1322 skb_set_owner_r(opt_skb, sk);
1323 tcp_v6_restore_cb(opt_skb);
1324 opt_skb = xchg(&np->pktoptions, opt_skb);
1326 __kfree_skb(opt_skb);
1327 opt_skb = xchg(&np->pktoptions, NULL);
1335 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1336 const struct tcphdr *th)
1338 /* This is tricky: we move IP6CB at its correct location into
1339 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1340 * _decode_session6() uses IP6CB().
1341 * barrier() makes sure compiler won't play aliasing games.
1343 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1344 sizeof(struct inet6_skb_parm));
1347 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1348 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1349 skb->len - th->doff*4);
1350 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1351 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1352 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1353 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1354 TCP_SKB_CB(skb)->sacked = 0;
1357 static int tcp_v6_rcv(struct sk_buff *skb)
1359 const struct tcphdr *th;
1360 const struct ipv6hdr *hdr;
1363 struct net *net = dev_net(skb->dev);
1365 if (skb->pkt_type != PACKET_HOST)
1369 * Count it even if it's bad.
1371 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1373 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1378 if (th->doff < sizeof(struct tcphdr)/4)
1380 if (!pskb_may_pull(skb, th->doff*4))
1383 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1387 hdr = ipv6_hdr(skb);
1390 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1396 if (sk->sk_state == TCP_TIME_WAIT)
1399 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1400 struct request_sock *req = inet_reqsk(sk);
1403 sk = req->rsk_listener;
1404 tcp_v6_fill_cb(skb, hdr, th);
1405 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1409 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1410 inet_csk_reqsk_queue_drop_and_put(sk, req);
1414 nsk = tcp_check_req(sk, skb, req, false);
1417 goto discard_and_relse;
1421 tcp_v6_restore_cb(skb);
1422 } else if (tcp_child_process(sk, nsk, skb)) {
1423 tcp_v6_send_reset(nsk, skb);
1424 goto discard_and_relse;
1430 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1431 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1432 goto discard_and_relse;
1435 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1436 goto discard_and_relse;
1438 tcp_v6_fill_cb(skb, hdr, th);
1440 if (tcp_v6_inbound_md5_hash(sk, skb))
1441 goto discard_and_relse;
1443 if (tcp_filter(sk, skb))
1444 goto discard_and_relse;
1445 th = (const struct tcphdr *)skb->data;
1446 hdr = ipv6_hdr(skb);
1450 if (sk->sk_state == TCP_LISTEN) {
1451 ret = tcp_v6_do_rcv(sk, skb);
1452 goto put_and_return;
1455 sk_incoming_cpu_update(sk);
1457 bh_lock_sock_nested(sk);
1458 tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1460 if (!sock_owned_by_user(sk)) {
1461 if (!tcp_prequeue(sk, skb))
1462 ret = tcp_v6_do_rcv(sk, skb);
1463 } else if (unlikely(sk_add_backlog(sk, skb,
1464 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1466 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1467 goto discard_and_relse;
1473 return ret ? -1 : 0;
1476 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1479 tcp_v6_fill_cb(skb, hdr, th);
1481 if (tcp_checksum_complete(skb)) {
1483 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1485 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1487 tcp_v6_send_reset(NULL, skb);
1499 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1500 inet_twsk_put(inet_twsk(sk));
1504 tcp_v6_fill_cb(skb, hdr, th);
1506 if (tcp_checksum_complete(skb)) {
1507 inet_twsk_put(inet_twsk(sk));
1511 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1516 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1517 &ipv6_hdr(skb)->saddr, th->source,
1518 &ipv6_hdr(skb)->daddr,
1519 ntohs(th->dest), tcp_v6_iif(skb));
1521 struct inet_timewait_sock *tw = inet_twsk(sk);
1522 inet_twsk_deschedule_put(tw);
1524 tcp_v6_restore_cb(skb);
1527 /* Fall through to ACK */
1530 tcp_v6_timewait_ack(sk, skb);
1533 tcp_v6_restore_cb(skb);
1535 case TCP_TW_SUCCESS:
1541 static void tcp_v6_early_demux(struct sk_buff *skb)
1543 const struct ipv6hdr *hdr;
1544 const struct tcphdr *th;
1547 if (skb->pkt_type != PACKET_HOST)
1550 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1553 hdr = ipv6_hdr(skb);
1556 if (th->doff < sizeof(struct tcphdr) / 4)
1559 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1560 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1561 &hdr->saddr, th->source,
1562 &hdr->daddr, ntohs(th->dest),
1566 skb->destructor = sock_edemux;
1567 if (sk_fullsock(sk)) {
1568 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1571 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1573 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1574 skb_dst_set_noref(skb, dst);
1579 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1580 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1581 .twsk_unique = tcp_twsk_unique,
1582 .twsk_destructor = tcp_twsk_destructor,
1585 static const struct inet_connection_sock_af_ops ipv6_specific = {
1586 .queue_xmit = inet6_csk_xmit,
1587 .send_check = tcp_v6_send_check,
1588 .rebuild_header = inet6_sk_rebuild_header,
1589 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1590 .conn_request = tcp_v6_conn_request,
1591 .syn_recv_sock = tcp_v6_syn_recv_sock,
1592 .net_header_len = sizeof(struct ipv6hdr),
1593 .net_frag_header_len = sizeof(struct frag_hdr),
1594 .setsockopt = ipv6_setsockopt,
1595 .getsockopt = ipv6_getsockopt,
1596 .addr2sockaddr = inet6_csk_addr2sockaddr,
1597 .sockaddr_len = sizeof(struct sockaddr_in6),
1598 .bind_conflict = inet6_csk_bind_conflict,
1599 #ifdef CONFIG_COMPAT
1600 .compat_setsockopt = compat_ipv6_setsockopt,
1601 .compat_getsockopt = compat_ipv6_getsockopt,
1603 .mtu_reduced = tcp_v6_mtu_reduced,
1606 #ifdef CONFIG_TCP_MD5SIG
1607 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1608 .md5_lookup = tcp_v6_md5_lookup,
1609 .calc_md5_hash = tcp_v6_md5_hash_skb,
1610 .md5_parse = tcp_v6_parse_md5_keys,
1615 * TCP over IPv4 via INET6 API
1617 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1618 .queue_xmit = ip_queue_xmit,
1619 .send_check = tcp_v4_send_check,
1620 .rebuild_header = inet_sk_rebuild_header,
1621 .sk_rx_dst_set = inet_sk_rx_dst_set,
1622 .conn_request = tcp_v6_conn_request,
1623 .syn_recv_sock = tcp_v6_syn_recv_sock,
1624 .net_header_len = sizeof(struct iphdr),
1625 .setsockopt = ipv6_setsockopt,
1626 .getsockopt = ipv6_getsockopt,
1627 .addr2sockaddr = inet6_csk_addr2sockaddr,
1628 .sockaddr_len = sizeof(struct sockaddr_in6),
1629 .bind_conflict = inet6_csk_bind_conflict,
1630 #ifdef CONFIG_COMPAT
1631 .compat_setsockopt = compat_ipv6_setsockopt,
1632 .compat_getsockopt = compat_ipv6_getsockopt,
1634 .mtu_reduced = tcp_v4_mtu_reduced,
1637 #ifdef CONFIG_TCP_MD5SIG
1638 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1639 .md5_lookup = tcp_v4_md5_lookup,
1640 .calc_md5_hash = tcp_v4_md5_hash_skb,
1641 .md5_parse = tcp_v6_parse_md5_keys,
1645 /* NOTE: A lot of things set to zero explicitly by call to
1646 * sk_alloc() so need not be done here.
1648 static int tcp_v6_init_sock(struct sock *sk)
1650 struct inet_connection_sock *icsk = inet_csk(sk);
1654 icsk->icsk_af_ops = &ipv6_specific;
1656 #ifdef CONFIG_TCP_MD5SIG
1657 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1663 static void tcp_v6_destroy_sock(struct sock *sk)
1665 tcp_v4_destroy_sock(sk);
1666 inet6_destroy_sock(sk);
1669 #ifdef CONFIG_PROC_FS
1670 /* Proc filesystem TCPv6 sock list dumping. */
1671 static void get_openreq6(struct seq_file *seq,
1672 const struct request_sock *req, int i)
1674 long ttd = req->rsk_timer.expires - jiffies;
1675 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1676 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1682 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1683 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1685 src->s6_addr32[0], src->s6_addr32[1],
1686 src->s6_addr32[2], src->s6_addr32[3],
1687 inet_rsk(req)->ir_num,
1688 dest->s6_addr32[0], dest->s6_addr32[1],
1689 dest->s6_addr32[2], dest->s6_addr32[3],
1690 ntohs(inet_rsk(req)->ir_rmt_port),
1692 0, 0, /* could print option size, but that is af dependent. */
1693 1, /* timers active (only the expire timer) */
1694 jiffies_to_clock_t(ttd),
1696 from_kuid_munged(seq_user_ns(seq),
1697 sock_i_uid(req->rsk_listener)),
1698 0, /* non standard timer */
1699 0, /* open_requests have no inode */
1703 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1705 const struct in6_addr *dest, *src;
1708 unsigned long timer_expires;
1709 const struct inet_sock *inet = inet_sk(sp);
1710 const struct tcp_sock *tp = tcp_sk(sp);
1711 const struct inet_connection_sock *icsk = inet_csk(sp);
1712 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1716 dest = &sp->sk_v6_daddr;
1717 src = &sp->sk_v6_rcv_saddr;
1718 destp = ntohs(inet->inet_dport);
1719 srcp = ntohs(inet->inet_sport);
1721 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1722 icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
1723 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1725 timer_expires = icsk->icsk_timeout;
1726 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1728 timer_expires = icsk->icsk_timeout;
1729 } else if (timer_pending(&sp->sk_timer)) {
1731 timer_expires = sp->sk_timer.expires;
1734 timer_expires = jiffies;
1737 state = sk_state_load(sp);
1738 if (state == TCP_LISTEN)
1739 rx_queue = sp->sk_ack_backlog;
1741 /* Because we don't lock the socket,
1742 * we might find a transient negative value.
1744 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1747 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1748 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1750 src->s6_addr32[0], src->s6_addr32[1],
1751 src->s6_addr32[2], src->s6_addr32[3], srcp,
1752 dest->s6_addr32[0], dest->s6_addr32[1],
1753 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1755 tp->write_seq - tp->snd_una,
1758 jiffies_delta_to_clock_t(timer_expires - jiffies),
1759 icsk->icsk_retransmits,
1760 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1761 icsk->icsk_probes_out,
1763 atomic_read(&sp->sk_refcnt), sp,
1764 jiffies_to_clock_t(icsk->icsk_rto),
1765 jiffies_to_clock_t(icsk->icsk_ack.ato),
1766 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1768 state == TCP_LISTEN ?
1769 fastopenq->max_qlen :
1770 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1774 static void get_timewait6_sock(struct seq_file *seq,
1775 struct inet_timewait_sock *tw, int i)
1777 long delta = tw->tw_timer.expires - jiffies;
1778 const struct in6_addr *dest, *src;
1781 dest = &tw->tw_v6_daddr;
1782 src = &tw->tw_v6_rcv_saddr;
1783 destp = ntohs(tw->tw_dport);
1784 srcp = ntohs(tw->tw_sport);
1787 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1788 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1790 src->s6_addr32[0], src->s6_addr32[1],
1791 src->s6_addr32[2], src->s6_addr32[3], srcp,
1792 dest->s6_addr32[0], dest->s6_addr32[1],
1793 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1794 tw->tw_substate, 0, 0,
1795 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1796 atomic_read(&tw->tw_refcnt), tw);
1799 static int tcp6_seq_show(struct seq_file *seq, void *v)
1801 struct tcp_iter_state *st;
1802 struct sock *sk = v;
1804 if (v == SEQ_START_TOKEN) {
1809 "st tx_queue rx_queue tr tm->when retrnsmt"
1810 " uid timeout inode\n");
1815 if (sk->sk_state == TCP_TIME_WAIT)
1816 get_timewait6_sock(seq, v, st->num);
1817 else if (sk->sk_state == TCP_NEW_SYN_RECV)
1818 get_openreq6(seq, v, st->num);
1820 get_tcp6_sock(seq, v, st->num);
1825 static const struct file_operations tcp6_afinfo_seq_fops = {
1826 .owner = THIS_MODULE,
1827 .open = tcp_seq_open,
1829 .llseek = seq_lseek,
1830 .release = seq_release_net
1833 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1836 .seq_fops = &tcp6_afinfo_seq_fops,
1838 .show = tcp6_seq_show,
1842 int __net_init tcp6_proc_init(struct net *net)
1844 return tcp_proc_register(net, &tcp6_seq_afinfo);
1847 void tcp6_proc_exit(struct net *net)
1849 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1853 static void tcp_v6_clear_sk(struct sock *sk, int size)
1855 struct inet_sock *inet = inet_sk(sk);
1857 /* we do not want to clear pinet6 field, because of RCU lookups */
1858 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1860 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1861 memset(&inet->pinet6 + 1, 0, size);
1864 struct proto tcpv6_prot = {
1866 .owner = THIS_MODULE,
1868 .connect = tcp_v6_connect,
1869 .disconnect = tcp_disconnect,
1870 .accept = inet_csk_accept,
1872 .init = tcp_v6_init_sock,
1873 .destroy = tcp_v6_destroy_sock,
1874 .shutdown = tcp_shutdown,
1875 .setsockopt = tcp_setsockopt,
1876 .getsockopt = tcp_getsockopt,
1877 .recvmsg = tcp_recvmsg,
1878 .sendmsg = tcp_sendmsg,
1879 .sendpage = tcp_sendpage,
1880 .backlog_rcv = tcp_v6_do_rcv,
1881 .release_cb = tcp_release_cb,
1883 .unhash = inet_unhash,
1884 .get_port = inet_csk_get_port,
1885 .enter_memory_pressure = tcp_enter_memory_pressure,
1886 .stream_memory_free = tcp_stream_memory_free,
1887 .sockets_allocated = &tcp_sockets_allocated,
1888 .memory_allocated = &tcp_memory_allocated,
1889 .memory_pressure = &tcp_memory_pressure,
1890 .orphan_count = &tcp_orphan_count,
1891 .sysctl_mem = sysctl_tcp_mem,
1892 .sysctl_wmem = sysctl_tcp_wmem,
1893 .sysctl_rmem = sysctl_tcp_rmem,
1894 .max_header = MAX_TCP_HEADER,
1895 .obj_size = sizeof(struct tcp6_sock),
1896 .slab_flags = SLAB_DESTROY_BY_RCU,
1897 .twsk_prot = &tcp6_timewait_sock_ops,
1898 .rsk_prot = &tcp6_request_sock_ops,
1899 .h.hashinfo = &tcp_hashinfo,
1900 .no_autobind = true,
1901 #ifdef CONFIG_COMPAT
1902 .compat_setsockopt = compat_tcp_setsockopt,
1903 .compat_getsockopt = compat_tcp_getsockopt,
1905 #ifdef CONFIG_MEMCG_KMEM
1906 .proto_cgroup = tcp_proto_cgroup,
1908 .clear_sk = tcp_v6_clear_sk,
1911 static const struct inet6_protocol tcpv6_protocol = {
1912 .early_demux = tcp_v6_early_demux,
1913 .handler = tcp_v6_rcv,
1914 .err_handler = tcp_v6_err,
1915 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1918 static struct inet_protosw tcpv6_protosw = {
1919 .type = SOCK_STREAM,
1920 .protocol = IPPROTO_TCP,
1921 .prot = &tcpv6_prot,
1922 .ops = &inet6_stream_ops,
1923 .flags = INET_PROTOSW_PERMANENT |
1927 static int __net_init tcpv6_net_init(struct net *net)
1929 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1930 SOCK_RAW, IPPROTO_TCP, net);
1933 static void __net_exit tcpv6_net_exit(struct net *net)
1935 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1938 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1940 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1943 static struct pernet_operations tcpv6_net_ops = {
1944 .init = tcpv6_net_init,
1945 .exit = tcpv6_net_exit,
1946 .exit_batch = tcpv6_net_exit_batch,
1949 int __init tcpv6_init(void)
1953 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1957 /* register inet6 protocol */
1958 ret = inet6_register_protosw(&tcpv6_protosw);
1960 goto out_tcpv6_protocol;
1962 ret = register_pernet_subsys(&tcpv6_net_ops);
1964 goto out_tcpv6_protosw;
1969 inet6_unregister_protosw(&tcpv6_protosw);
1971 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1975 void tcpv6_exit(void)
1977 unregister_pernet_subsys(&tcpv6_net_ops);
1978 inet6_unregister_protosw(&tcpv6_protosw);
1979 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);