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>
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/netdma.h>
63 #include <net/inet_common.h>
64 #include <net/secure_seq.h>
65 #include <net/tcp_memcontrol.h>
67 #include <asm/uaccess.h>
69 #include <linux/proc_fs.h>
70 #include <linux/seq_file.h>
72 #include <linux/crypto.h>
73 #include <linux/scatterlist.h>
75 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
76 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
77 struct request_sock *req);
79 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
81 static const struct inet_connection_sock_af_ops ipv6_mapped;
82 static const struct inet_connection_sock_af_ops ipv6_specific;
83 #ifdef CONFIG_TCP_MD5SIG
84 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
85 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
87 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
88 const struct in6_addr *addr)
94 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
96 struct dst_entry *dst = skb_dst(skb);
97 const struct rt6_info *rt = (const struct rt6_info *)dst;
101 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
103 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
106 static void tcp_v6_hash(struct sock *sk)
108 if (sk->sk_state != TCP_CLOSE) {
109 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
114 __inet6_hash(sk, NULL);
119 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
121 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
122 ipv6_hdr(skb)->saddr.s6_addr32,
124 tcp_hdr(skb)->source);
127 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
130 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
131 struct inet_sock *inet = inet_sk(sk);
132 struct inet_connection_sock *icsk = inet_csk(sk);
133 struct ipv6_pinfo *np = inet6_sk(sk);
134 struct tcp_sock *tp = tcp_sk(sk);
135 struct in6_addr *saddr = NULL, *final_p, final;
138 struct dst_entry *dst;
142 if (addr_len < SIN6_LEN_RFC2133)
145 if (usin->sin6_family != AF_INET6)
146 return -EAFNOSUPPORT;
148 memset(&fl6, 0, sizeof(fl6));
151 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
152 IP6_ECN_flow_init(fl6.flowlabel);
153 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
154 struct ip6_flowlabel *flowlabel;
155 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
156 if (flowlabel == NULL)
158 usin->sin6_addr = flowlabel->dst;
159 fl6_sock_release(flowlabel);
164 * connect() to INADDR_ANY means loopback (BSD'ism).
167 if(ipv6_addr_any(&usin->sin6_addr))
168 usin->sin6_addr.s6_addr[15] = 0x1;
170 addr_type = ipv6_addr_type(&usin->sin6_addr);
172 if(addr_type & IPV6_ADDR_MULTICAST)
175 if (addr_type&IPV6_ADDR_LINKLOCAL) {
176 if (addr_len >= sizeof(struct sockaddr_in6) &&
177 usin->sin6_scope_id) {
178 /* If interface is set while binding, indices
181 if (sk->sk_bound_dev_if &&
182 sk->sk_bound_dev_if != usin->sin6_scope_id)
185 sk->sk_bound_dev_if = usin->sin6_scope_id;
188 /* Connect to link-local address requires an interface */
189 if (!sk->sk_bound_dev_if)
193 if (tp->rx_opt.ts_recent_stamp &&
194 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
195 tp->rx_opt.ts_recent = 0;
196 tp->rx_opt.ts_recent_stamp = 0;
200 np->daddr = usin->sin6_addr;
201 np->flow_label = fl6.flowlabel;
207 if (addr_type == IPV6_ADDR_MAPPED) {
208 u32 exthdrlen = icsk->icsk_ext_hdr_len;
209 struct sockaddr_in sin;
211 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
213 if (__ipv6_only_sock(sk))
216 sin.sin_family = AF_INET;
217 sin.sin_port = usin->sin6_port;
218 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
220 icsk->icsk_af_ops = &ipv6_mapped;
221 sk->sk_backlog_rcv = tcp_v4_do_rcv;
222 #ifdef CONFIG_TCP_MD5SIG
223 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
226 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
229 icsk->icsk_ext_hdr_len = exthdrlen;
230 icsk->icsk_af_ops = &ipv6_specific;
231 sk->sk_backlog_rcv = tcp_v6_do_rcv;
232 #ifdef CONFIG_TCP_MD5SIG
233 tp->af_specific = &tcp_sock_ipv6_specific;
237 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
238 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
245 if (!ipv6_addr_any(&np->rcv_saddr))
246 saddr = &np->rcv_saddr;
248 fl6.flowi6_proto = IPPROTO_TCP;
249 fl6.daddr = np->daddr;
250 fl6.saddr = saddr ? *saddr : np->saddr;
251 fl6.flowi6_oif = sk->sk_bound_dev_if;
252 fl6.flowi6_mark = sk->sk_mark;
253 fl6.fl6_dport = usin->sin6_port;
254 fl6.fl6_sport = inet->inet_sport;
255 fl6.flowi6_uid = sock_i_uid(sk);
257 final_p = fl6_update_dst(&fl6, np->opt, &final);
259 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
261 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
269 np->rcv_saddr = *saddr;
272 /* set the source address */
274 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
276 sk->sk_gso_type = SKB_GSO_TCPV6;
277 __ip6_dst_store(sk, dst, NULL, NULL);
279 rt = (struct rt6_info *) dst;
280 if (tcp_death_row.sysctl_tw_recycle &&
281 !tp->rx_opt.ts_recent_stamp &&
282 ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr))
283 tcp_fetch_timewait_stamp(sk, dst);
285 icsk->icsk_ext_hdr_len = 0;
287 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
290 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
292 inet->inet_dport = usin->sin6_port;
294 tcp_set_state(sk, TCP_SYN_SENT);
295 err = inet6_hash_connect(&tcp_death_row, sk);
299 if (!tp->write_seq && likely(!tp->repair))
300 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
305 err = tcp_connect(sk);
312 tcp_set_state(sk, TCP_CLOSE);
315 inet->inet_dport = 0;
316 sk->sk_route_caps = 0;
320 static void tcp_v6_mtu_reduced(struct sock *sk)
322 struct dst_entry *dst;
324 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
327 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
331 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
332 tcp_sync_mss(sk, dst_mtu(dst));
333 tcp_simple_retransmit(sk);
337 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
338 u8 type, u8 code, int offset, __be32 info)
340 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
341 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
342 struct ipv6_pinfo *np;
347 struct net *net = dev_net(skb->dev);
349 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
350 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
353 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
358 if (sk->sk_state == TCP_TIME_WAIT) {
359 inet_twsk_put(inet_twsk(sk));
364 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
365 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
367 if (sk->sk_state == TCP_CLOSE)
370 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
371 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
376 seq = ntohl(th->seq);
377 if (sk->sk_state != TCP_LISTEN &&
378 !between(seq, tp->snd_una, tp->snd_nxt)) {
379 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
385 if (type == NDISC_REDIRECT) {
386 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
389 dst->ops->redirect(dst, sk, skb);
393 if (type == ICMPV6_PKT_TOOBIG) {
394 /* We are not interested in TCP_LISTEN and open_requests
395 * (SYN-ACKs send out by Linux are always <576bytes so
396 * they should go through unfragmented).
398 if (sk->sk_state == TCP_LISTEN)
401 tp->mtu_info = ntohl(info);
402 if (!sock_owned_by_user(sk))
403 tcp_v6_mtu_reduced(sk);
404 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
410 icmpv6_err_convert(type, code, &err);
412 /* Might be for an request_sock */
413 switch (sk->sk_state) {
414 struct request_sock *req, **prev;
416 if (sock_owned_by_user(sk))
419 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
420 &hdr->saddr, inet6_iif(skb));
424 /* ICMPs are not backlogged, hence we cannot get
425 * an established socket here.
427 WARN_ON(req->sk != NULL);
429 if (seq != tcp_rsk(req)->snt_isn) {
430 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
434 inet_csk_reqsk_queue_drop(sk, req, prev);
435 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
439 case TCP_SYN_RECV: /* Cannot happen.
440 It can, it SYNs are crossed. --ANK */
441 if (!sock_owned_by_user(sk)) {
443 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
447 sk->sk_err_soft = err;
451 if (!sock_owned_by_user(sk) && np->recverr) {
453 sk->sk_error_report(sk);
455 sk->sk_err_soft = err;
463 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
465 struct request_sock *req,
468 struct inet6_request_sock *treq = inet6_rsk(req);
469 struct ipv6_pinfo *np = inet6_sk(sk);
470 struct sk_buff * skb;
473 /* First, grab a route. */
474 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
477 skb = tcp_make_synack(sk, dst, req, NULL);
480 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
482 fl6->daddr = treq->rmt_addr;
483 skb_set_queue_mapping(skb, queue_mapping);
484 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
485 err = net_xmit_eval(err);
492 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
497 res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
499 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
503 static void tcp_v6_reqsk_destructor(struct request_sock *req)
505 kfree_skb(inet6_rsk(req)->pktopts);
508 #ifdef CONFIG_TCP_MD5SIG
509 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
510 const struct in6_addr *addr)
512 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
515 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
516 struct sock *addr_sk)
518 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
521 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
522 struct request_sock *req)
524 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
527 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
530 struct tcp_md5sig cmd;
531 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
533 if (optlen < sizeof(cmd))
536 if (copy_from_user(&cmd, optval, sizeof(cmd)))
539 if (sin6->sin6_family != AF_INET6)
542 if (!cmd.tcpm_keylen) {
543 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
544 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
546 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
550 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
553 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
554 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
555 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
557 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
558 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
561 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
562 const struct in6_addr *daddr,
563 const struct in6_addr *saddr, int nbytes)
565 struct tcp6_pseudohdr *bp;
566 struct scatterlist sg;
568 bp = &hp->md5_blk.ip6;
569 /* 1. TCP pseudo-header (RFC2460) */
572 bp->protocol = cpu_to_be32(IPPROTO_TCP);
573 bp->len = cpu_to_be32(nbytes);
575 sg_init_one(&sg, bp, sizeof(*bp));
576 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
579 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
580 const struct in6_addr *daddr, struct in6_addr *saddr,
581 const struct tcphdr *th)
583 struct tcp_md5sig_pool *hp;
584 struct hash_desc *desc;
586 hp = tcp_get_md5sig_pool();
588 goto clear_hash_noput;
589 desc = &hp->md5_desc;
591 if (crypto_hash_init(desc))
593 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
595 if (tcp_md5_hash_header(hp, th))
597 if (tcp_md5_hash_key(hp, key))
599 if (crypto_hash_final(desc, md5_hash))
602 tcp_put_md5sig_pool();
606 tcp_put_md5sig_pool();
608 memset(md5_hash, 0, 16);
612 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
613 const struct sock *sk,
614 const struct request_sock *req,
615 const struct sk_buff *skb)
617 const struct in6_addr *saddr, *daddr;
618 struct tcp_md5sig_pool *hp;
619 struct hash_desc *desc;
620 const struct tcphdr *th = tcp_hdr(skb);
623 saddr = &inet6_sk(sk)->saddr;
624 daddr = &inet6_sk(sk)->daddr;
626 saddr = &inet6_rsk(req)->loc_addr;
627 daddr = &inet6_rsk(req)->rmt_addr;
629 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
630 saddr = &ip6h->saddr;
631 daddr = &ip6h->daddr;
634 hp = tcp_get_md5sig_pool();
636 goto clear_hash_noput;
637 desc = &hp->md5_desc;
639 if (crypto_hash_init(desc))
642 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
644 if (tcp_md5_hash_header(hp, th))
646 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
648 if (tcp_md5_hash_key(hp, key))
650 if (crypto_hash_final(desc, md5_hash))
653 tcp_put_md5sig_pool();
657 tcp_put_md5sig_pool();
659 memset(md5_hash, 0, 16);
663 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
665 const __u8 *hash_location = NULL;
666 struct tcp_md5sig_key *hash_expected;
667 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
668 const struct tcphdr *th = tcp_hdr(skb);
672 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
673 hash_location = tcp_parse_md5sig_option(th);
675 /* We've parsed the options - do we have a hash? */
676 if (!hash_expected && !hash_location)
679 if (hash_expected && !hash_location) {
680 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
684 if (!hash_expected && hash_location) {
685 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
689 /* check the signature */
690 genhash = tcp_v6_md5_hash_skb(newhash,
694 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
695 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
696 genhash ? "failed" : "mismatch",
697 &ip6h->saddr, ntohs(th->source),
698 &ip6h->daddr, ntohs(th->dest));
705 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
707 .obj_size = sizeof(struct tcp6_request_sock),
708 .rtx_syn_ack = tcp_v6_rtx_synack,
709 .send_ack = tcp_v6_reqsk_send_ack,
710 .destructor = tcp_v6_reqsk_destructor,
711 .send_reset = tcp_v6_send_reset,
712 .syn_ack_timeout = tcp_syn_ack_timeout,
715 #ifdef CONFIG_TCP_MD5SIG
716 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
717 .md5_lookup = tcp_v6_reqsk_md5_lookup,
718 .calc_md5_hash = tcp_v6_md5_hash_skb,
722 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
723 u32 tsval, u32 tsecr,
724 struct tcp_md5sig_key *key, int rst, u8 tclass)
726 const struct tcphdr *th = tcp_hdr(skb);
728 struct sk_buff *buff;
730 struct net *net = dev_net(skb_dst(skb)->dev);
731 struct sock *ctl_sk = net->ipv6.tcp_sk;
732 unsigned int tot_len = sizeof(struct tcphdr);
733 struct dst_entry *dst;
737 tot_len += TCPOLEN_TSTAMP_ALIGNED;
738 #ifdef CONFIG_TCP_MD5SIG
740 tot_len += TCPOLEN_MD5SIG_ALIGNED;
743 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
748 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
750 t1 = (struct tcphdr *) skb_push(buff, tot_len);
751 skb_reset_transport_header(buff);
753 /* Swap the send and the receive. */
754 memset(t1, 0, sizeof(*t1));
755 t1->dest = th->source;
756 t1->source = th->dest;
757 t1->doff = tot_len / 4;
758 t1->seq = htonl(seq);
759 t1->ack_seq = htonl(ack);
760 t1->ack = !rst || !th->ack;
762 t1->window = htons(win);
764 topt = (__be32 *)(t1 + 1);
767 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
768 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
769 *topt++ = htonl(tsval);
770 *topt++ = htonl(tsecr);
773 #ifdef CONFIG_TCP_MD5SIG
775 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
776 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
777 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
778 &ipv6_hdr(skb)->saddr,
779 &ipv6_hdr(skb)->daddr, t1);
783 memset(&fl6, 0, sizeof(fl6));
784 fl6.daddr = ipv6_hdr(skb)->saddr;
785 fl6.saddr = ipv6_hdr(skb)->daddr;
787 buff->ip_summed = CHECKSUM_PARTIAL;
790 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
792 fl6.flowi6_proto = IPPROTO_TCP;
793 if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
794 fl6.flowi6_oif = inet6_iif(skb);
795 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
796 fl6.fl6_dport = t1->dest;
797 fl6.fl6_sport = t1->source;
798 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
800 /* Pass a socket to ip6_dst_lookup either it is for RST
801 * Underlying function will use this to retrieve the network
804 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
806 skb_dst_set(buff, dst);
807 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
808 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
810 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
817 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
819 const struct tcphdr *th = tcp_hdr(skb);
820 u32 seq = 0, ack_seq = 0;
821 struct tcp_md5sig_key *key = NULL;
822 #ifdef CONFIG_TCP_MD5SIG
823 const __u8 *hash_location = NULL;
824 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
825 unsigned char newhash[16];
827 struct sock *sk1 = NULL;
833 if (!ipv6_unicast_destination(skb))
836 #ifdef CONFIG_TCP_MD5SIG
837 hash_location = tcp_parse_md5sig_option(th);
838 if (!sk && hash_location) {
840 * active side is lost. Try to find listening socket through
841 * source port, and then find md5 key through listening socket.
842 * we are not loose security here:
843 * Incoming packet is checked with md5 hash with finding key,
844 * no RST generated if md5 hash doesn't match.
846 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
847 &tcp_hashinfo, &ipv6h->saddr,
848 th->source, &ipv6h->daddr,
849 ntohs(th->source), inet6_iif(skb));
854 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
858 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
859 if (genhash || memcmp(hash_location, newhash, 16) != 0)
862 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
867 seq = ntohl(th->ack_seq);
869 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
872 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, key, 1, 0);
874 #ifdef CONFIG_TCP_MD5SIG
883 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
884 u32 win, u32 tsval, u32 tsecr,
885 struct tcp_md5sig_key *key, u8 tclass)
887 tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, key, 0, tclass);
890 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
892 struct inet_timewait_sock *tw = inet_twsk(sk);
893 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
895 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
896 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
897 tcp_time_stamp + tcptw->tw_ts_offset,
898 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
904 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
905 struct request_sock *req)
907 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
908 req->rcv_wnd, tcp_time_stamp, req->ts_recent,
909 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
913 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
915 struct request_sock *req, **prev;
916 const struct tcphdr *th = tcp_hdr(skb);
919 /* Find possible connection requests. */
920 req = inet6_csk_search_req(sk, &prev, th->source,
921 &ipv6_hdr(skb)->saddr,
922 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
924 return tcp_check_req(sk, skb, req, prev, false);
926 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
927 &ipv6_hdr(skb)->saddr, th->source,
928 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
931 if (nsk->sk_state != TCP_TIME_WAIT) {
935 inet_twsk_put(inet_twsk(nsk));
939 #ifdef CONFIG_SYN_COOKIES
941 sk = cookie_v6_check(sk, skb);
946 /* FIXME: this is substantially similar to the ipv4 code.
947 * Can some kind of merge be done? -- erics
949 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
951 struct tcp_options_received tmp_opt;
952 struct request_sock *req;
953 struct inet6_request_sock *treq;
954 struct ipv6_pinfo *np = inet6_sk(sk);
955 struct tcp_sock *tp = tcp_sk(sk);
956 __u32 isn = TCP_SKB_CB(skb)->when;
957 struct dst_entry *dst = NULL;
959 bool want_cookie = false;
961 if (skb->protocol == htons(ETH_P_IP))
962 return tcp_v4_conn_request(sk, skb);
964 if (!ipv6_unicast_destination(skb))
967 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
968 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
973 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
974 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
978 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
982 #ifdef CONFIG_TCP_MD5SIG
983 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
986 tcp_clear_options(&tmp_opt);
987 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
988 tmp_opt.user_mss = tp->rx_opt.user_mss;
989 tcp_parse_options(skb, &tmp_opt, 0, NULL);
991 if (want_cookie && !tmp_opt.saw_tstamp)
992 tcp_clear_options(&tmp_opt);
994 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
995 tcp_openreq_init(req, &tmp_opt, skb);
997 treq = inet6_rsk(req);
998 treq->rmt_addr = ipv6_hdr(skb)->saddr;
999 treq->loc_addr = ipv6_hdr(skb)->daddr;
1000 if (!want_cookie || tmp_opt.tstamp_ok)
1001 TCP_ECN_create_request(req, skb, sock_net(sk));
1003 treq->iif = sk->sk_bound_dev_if;
1004 inet_rsk(req)->ir_mark = inet_request_mark(sk, skb);
1006 /* So that link locals have meaning */
1007 if (!sk->sk_bound_dev_if &&
1008 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1009 treq->iif = inet6_iif(skb);
1012 if (ipv6_opt_accepted(sk, skb) ||
1013 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1014 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1015 atomic_inc(&skb->users);
1016 treq->pktopts = skb;
1020 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1021 req->cookie_ts = tmp_opt.tstamp_ok;
1025 /* VJ's idea. We save last timestamp seen
1026 * from the destination in peer table, when entering
1027 * state TIME-WAIT, and check against it before
1028 * accepting new connection request.
1030 * If "isn" is not zero, this request hit alive
1031 * timewait bucket, so that all the necessary checks
1032 * are made in the function processing timewait state.
1034 if (tmp_opt.saw_tstamp &&
1035 tcp_death_row.sysctl_tw_recycle &&
1036 (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1037 if (!tcp_peer_is_proven(req, dst, true)) {
1038 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1039 goto drop_and_release;
1042 /* Kill the following clause, if you dislike this way. */
1043 else if (!sysctl_tcp_syncookies &&
1044 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1045 (sysctl_max_syn_backlog >> 2)) &&
1046 !tcp_peer_is_proven(req, dst, false)) {
1047 /* Without syncookies last quarter of
1048 * backlog is filled with destinations,
1049 * proven to be alive.
1050 * It means that we continue to communicate
1051 * to destinations, already remembered
1052 * to the moment of synflood.
1054 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1055 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1056 goto drop_and_release;
1059 isn = tcp_v6_init_sequence(skb);
1062 tcp_rsk(req)->snt_isn = isn;
1064 if (security_inet_conn_request(sk, skb, req))
1065 goto drop_and_release;
1067 if (tcp_v6_send_synack(sk, dst, &fl6, req,
1068 skb_get_queue_mapping(skb)) ||
1072 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1073 tcp_rsk(req)->listener = NULL;
1074 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1082 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1083 return 0; /* don't send reset */
1086 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1087 struct request_sock *req,
1088 struct dst_entry *dst)
1090 struct inet6_request_sock *treq;
1091 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1092 struct tcp6_sock *newtcp6sk;
1093 struct inet_sock *newinet;
1094 struct tcp_sock *newtp;
1096 #ifdef CONFIG_TCP_MD5SIG
1097 struct tcp_md5sig_key *key;
1101 if (skb->protocol == htons(ETH_P_IP)) {
1106 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1111 newtcp6sk = (struct tcp6_sock *)newsk;
1112 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1114 newinet = inet_sk(newsk);
1115 newnp = inet6_sk(newsk);
1116 newtp = tcp_sk(newsk);
1118 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1120 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1122 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1124 newnp->rcv_saddr = newnp->saddr;
1126 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1127 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1128 #ifdef CONFIG_TCP_MD5SIG
1129 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1132 newnp->ipv6_ac_list = NULL;
1133 newnp->ipv6_fl_list = NULL;
1134 newnp->pktoptions = NULL;
1136 newnp->mcast_oif = inet6_iif(skb);
1137 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1138 newnp->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
1141 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1142 * here, tcp_create_openreq_child now does this for us, see the comment in
1143 * that function for the gory details. -acme
1146 /* It is tricky place. Until this moment IPv4 tcp
1147 worked with IPv6 icsk.icsk_af_ops.
1150 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1155 treq = inet6_rsk(req);
1157 if (sk_acceptq_is_full(sk))
1161 dst = inet6_csk_route_req(sk, &fl6, req);
1166 newsk = tcp_create_openreq_child(sk, req, skb);
1171 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1172 * count here, tcp_create_openreq_child now does this for us, see the
1173 * comment in that function for the gory details. -acme
1176 newsk->sk_gso_type = SKB_GSO_TCPV6;
1177 __ip6_dst_store(newsk, dst, NULL, NULL);
1178 inet6_sk_rx_dst_set(newsk, skb);
1180 newtcp6sk = (struct tcp6_sock *)newsk;
1181 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1183 newtp = tcp_sk(newsk);
1184 newinet = inet_sk(newsk);
1185 newnp = inet6_sk(newsk);
1187 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1189 newnp->daddr = treq->rmt_addr;
1190 newnp->saddr = treq->loc_addr;
1191 newnp->rcv_saddr = treq->loc_addr;
1192 newsk->sk_bound_dev_if = treq->iif;
1194 /* Now IPv6 options...
1196 First: no IPv4 options.
1198 newinet->inet_opt = NULL;
1199 newnp->ipv6_ac_list = NULL;
1200 newnp->ipv6_fl_list = NULL;
1203 newnp->rxopt.all = np->rxopt.all;
1205 /* Clone pktoptions received with SYN */
1206 newnp->pktoptions = NULL;
1207 if (treq->pktopts != NULL) {
1208 newnp->pktoptions = skb_clone(treq->pktopts,
1209 sk_gfp_atomic(sk, GFP_ATOMIC));
1210 consume_skb(treq->pktopts);
1211 treq->pktopts = NULL;
1212 if (newnp->pktoptions)
1213 skb_set_owner_r(newnp->pktoptions, newsk);
1216 newnp->mcast_oif = inet6_iif(skb);
1217 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1218 newnp->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
1220 /* Clone native IPv6 options from listening socket (if any)
1222 Yes, keeping reference count would be much more clever,
1223 but we make one more one thing there: reattach optmem
1227 newnp->opt = ipv6_dup_options(newsk, np->opt);
1229 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1231 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1232 newnp->opt->opt_flen);
1234 tcp_mtup_init(newsk);
1235 tcp_sync_mss(newsk, dst_mtu(dst));
1236 newtp->advmss = dst_metric_advmss(dst);
1237 if (tcp_sk(sk)->rx_opt.user_mss &&
1238 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1239 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1241 tcp_initialize_rcv_mss(newsk);
1242 tcp_synack_rtt_meas(newsk, req);
1243 newtp->total_retrans = req->num_retrans;
1245 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1246 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1248 #ifdef CONFIG_TCP_MD5SIG
1249 /* Copy over the MD5 key from the original socket */
1250 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1251 /* We're using one, so create a matching key
1252 * on the newsk structure. If we fail to get
1253 * memory, then we end up not copying the key
1256 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1257 AF_INET6, key->key, key->keylen,
1258 sk_gfp_atomic(sk, GFP_ATOMIC));
1262 if (__inet_inherit_port(sk, newsk) < 0) {
1263 inet_csk_prepare_forced_close(newsk);
1267 __inet6_hash(newsk, NULL);
1272 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1276 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1280 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1282 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1283 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1284 &ipv6_hdr(skb)->daddr, skb->csum)) {
1285 skb->ip_summed = CHECKSUM_UNNECESSARY;
1290 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1291 &ipv6_hdr(skb)->saddr,
1292 &ipv6_hdr(skb)->daddr, 0));
1294 if (skb->len <= 76) {
1295 return __skb_checksum_complete(skb);
1300 /* The socket must have it's spinlock held when we get
1303 * We have a potential double-lock case here, so even when
1304 * doing backlog processing we use the BH locking scheme.
1305 * This is because we cannot sleep with the original spinlock
1308 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1310 struct ipv6_pinfo *np = inet6_sk(sk);
1311 struct tcp_sock *tp;
1312 struct sk_buff *opt_skb = NULL;
1314 /* Imagine: socket is IPv6. IPv4 packet arrives,
1315 goes to IPv4 receive handler and backlogged.
1316 From backlog it always goes here. Kerboom...
1317 Fortunately, tcp_rcv_established and rcv_established
1318 handle them correctly, but it is not case with
1319 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1322 if (skb->protocol == htons(ETH_P_IP))
1323 return tcp_v4_do_rcv(sk, skb);
1325 #ifdef CONFIG_TCP_MD5SIG
1326 if (tcp_v6_inbound_md5_hash (sk, skb))
1330 if (sk_filter(sk, skb))
1334 * socket locking is here for SMP purposes as backlog rcv
1335 * is currently called with bh processing disabled.
1338 /* Do Stevens' IPV6_PKTOPTIONS.
1340 Yes, guys, it is the only place in our code, where we
1341 may make it not affecting IPv4.
1342 The rest of code is protocol independent,
1343 and I do not like idea to uglify IPv4.
1345 Actually, all the idea behind IPV6_PKTOPTIONS
1346 looks not very well thought. For now we latch
1347 options, received in the last packet, enqueued
1348 by tcp. Feel free to propose better solution.
1352 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1354 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1355 struct dst_entry *dst = sk->sk_rx_dst;
1357 sock_rps_save_rxhash(sk, skb);
1359 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1360 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1362 sk->sk_rx_dst = NULL;
1366 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1369 goto ipv6_pktoptions;
1373 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1376 if (sk->sk_state == TCP_LISTEN) {
1377 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1382 * Queue it on the new socket if the new socket is active,
1383 * otherwise we just shortcircuit this and continue with
1387 sock_rps_save_rxhash(nsk, skb);
1388 if (tcp_child_process(sk, nsk, skb))
1391 __kfree_skb(opt_skb);
1395 sock_rps_save_rxhash(sk, skb);
1397 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1400 goto ipv6_pktoptions;
1404 tcp_v6_send_reset(sk, skb);
1407 __kfree_skb(opt_skb);
1411 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1412 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1417 /* Do you ask, what is it?
1419 1. skb was enqueued by tcp.
1420 2. skb is added to tail of read queue, rather than out of order.
1421 3. socket is not in passive state.
1422 4. Finally, it really contains options, which user wants to receive.
1425 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1426 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1427 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1428 np->mcast_oif = inet6_iif(opt_skb);
1429 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1430 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1431 if (np->rxopt.bits.rxtclass)
1432 np->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(opt_skb));
1433 if (ipv6_opt_accepted(sk, opt_skb)) {
1434 skb_set_owner_r(opt_skb, sk);
1435 opt_skb = xchg(&np->pktoptions, opt_skb);
1437 __kfree_skb(opt_skb);
1438 opt_skb = xchg(&np->pktoptions, NULL);
1446 static int tcp_v6_rcv(struct sk_buff *skb)
1448 const struct tcphdr *th;
1449 const struct ipv6hdr *hdr;
1452 struct net *net = dev_net(skb->dev);
1454 if (skb->pkt_type != PACKET_HOST)
1458 * Count it even if it's bad.
1460 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1462 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1467 if (th->doff < sizeof(struct tcphdr)/4)
1469 if (!pskb_may_pull(skb, th->doff*4))
1472 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1476 hdr = ipv6_hdr(skb);
1477 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1478 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1479 skb->len - th->doff*4);
1480 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1481 TCP_SKB_CB(skb)->when = 0;
1482 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1483 TCP_SKB_CB(skb)->sacked = 0;
1485 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1490 if (sk->sk_state == TCP_TIME_WAIT)
1493 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1494 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1495 goto discard_and_relse;
1498 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1499 goto discard_and_relse;
1501 if (sk_filter(sk, skb))
1502 goto discard_and_relse;
1506 bh_lock_sock_nested(sk);
1508 if (!sock_owned_by_user(sk)) {
1509 #ifdef CONFIG_NET_DMA
1510 struct tcp_sock *tp = tcp_sk(sk);
1511 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1512 tp->ucopy.dma_chan = net_dma_find_channel();
1513 if (tp->ucopy.dma_chan)
1514 ret = tcp_v6_do_rcv(sk, skb);
1518 if (!tcp_prequeue(sk, skb))
1519 ret = tcp_v6_do_rcv(sk, skb);
1521 } else if (unlikely(sk_add_backlog(sk, skb,
1522 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1524 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1525 goto discard_and_relse;
1530 return ret ? -1 : 0;
1533 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1536 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1538 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1540 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1542 tcp_v6_send_reset(NULL, skb);
1554 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1555 inet_twsk_put(inet_twsk(sk));
1559 if (skb->len < (th->doff<<2)) {
1560 inet_twsk_put(inet_twsk(sk));
1563 if (tcp_checksum_complete(skb)) {
1564 inet_twsk_put(inet_twsk(sk));
1568 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1573 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1574 &ipv6_hdr(skb)->saddr, th->source,
1575 &ipv6_hdr(skb)->daddr,
1576 ntohs(th->dest), inet6_iif(skb));
1578 struct inet_timewait_sock *tw = inet_twsk(sk);
1579 inet_twsk_deschedule(tw, &tcp_death_row);
1584 /* Fall through to ACK */
1587 tcp_v6_timewait_ack(sk, skb);
1591 case TCP_TW_SUCCESS:;
1596 static void tcp_v6_early_demux(struct sk_buff *skb)
1598 const struct ipv6hdr *hdr;
1599 const struct tcphdr *th;
1602 if (skb->pkt_type != PACKET_HOST)
1605 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1608 hdr = ipv6_hdr(skb);
1611 if (th->doff < sizeof(struct tcphdr) / 4)
1614 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1615 &hdr->saddr, th->source,
1616 &hdr->daddr, ntohs(th->dest),
1620 skb->destructor = sock_edemux;
1621 if (sk->sk_state != TCP_TIME_WAIT) {
1622 struct dst_entry *dst = sk->sk_rx_dst;
1625 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1627 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1628 skb_dst_set_noref(skb, dst);
1633 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1634 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1635 .twsk_unique = tcp_twsk_unique,
1636 .twsk_destructor= tcp_twsk_destructor,
1639 static const struct inet_connection_sock_af_ops ipv6_specific = {
1640 .queue_xmit = inet6_csk_xmit,
1641 .send_check = tcp_v6_send_check,
1642 .rebuild_header = inet6_sk_rebuild_header,
1643 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1644 .conn_request = tcp_v6_conn_request,
1645 .syn_recv_sock = tcp_v6_syn_recv_sock,
1646 .net_header_len = sizeof(struct ipv6hdr),
1647 .net_frag_header_len = sizeof(struct frag_hdr),
1648 .setsockopt = ipv6_setsockopt,
1649 .getsockopt = ipv6_getsockopt,
1650 .addr2sockaddr = inet6_csk_addr2sockaddr,
1651 .sockaddr_len = sizeof(struct sockaddr_in6),
1652 .bind_conflict = inet6_csk_bind_conflict,
1653 #ifdef CONFIG_COMPAT
1654 .compat_setsockopt = compat_ipv6_setsockopt,
1655 .compat_getsockopt = compat_ipv6_getsockopt,
1657 .mtu_reduced = tcp_v6_mtu_reduced,
1660 #ifdef CONFIG_TCP_MD5SIG
1661 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1662 .md5_lookup = tcp_v6_md5_lookup,
1663 .calc_md5_hash = tcp_v6_md5_hash_skb,
1664 .md5_parse = tcp_v6_parse_md5_keys,
1669 * TCP over IPv4 via INET6 API
1672 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1673 .queue_xmit = ip_queue_xmit,
1674 .send_check = tcp_v4_send_check,
1675 .rebuild_header = inet_sk_rebuild_header,
1676 .sk_rx_dst_set = inet_sk_rx_dst_set,
1677 .conn_request = tcp_v6_conn_request,
1678 .syn_recv_sock = tcp_v6_syn_recv_sock,
1679 .net_header_len = sizeof(struct iphdr),
1680 .setsockopt = ipv6_setsockopt,
1681 .getsockopt = ipv6_getsockopt,
1682 .addr2sockaddr = inet6_csk_addr2sockaddr,
1683 .sockaddr_len = sizeof(struct sockaddr_in6),
1684 .bind_conflict = inet6_csk_bind_conflict,
1685 #ifdef CONFIG_COMPAT
1686 .compat_setsockopt = compat_ipv6_setsockopt,
1687 .compat_getsockopt = compat_ipv6_getsockopt,
1689 .mtu_reduced = tcp_v4_mtu_reduced,
1692 #ifdef CONFIG_TCP_MD5SIG
1693 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1694 .md5_lookup = tcp_v4_md5_lookup,
1695 .calc_md5_hash = tcp_v4_md5_hash_skb,
1696 .md5_parse = tcp_v6_parse_md5_keys,
1700 /* NOTE: A lot of things set to zero explicitly by call to
1701 * sk_alloc() so need not be done here.
1703 static int tcp_v6_init_sock(struct sock *sk)
1705 struct inet_connection_sock *icsk = inet_csk(sk);
1709 icsk->icsk_af_ops = &ipv6_specific;
1711 #ifdef CONFIG_TCP_MD5SIG
1712 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1718 static void tcp_v6_destroy_sock(struct sock *sk)
1720 tcp_v4_destroy_sock(sk);
1721 inet6_destroy_sock(sk);
1724 #ifdef CONFIG_PROC_FS
1725 /* Proc filesystem TCPv6 sock list dumping. */
1726 static void get_openreq6(struct seq_file *seq,
1727 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1729 int ttd = req->expires - jiffies;
1730 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1731 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1737 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1738 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1740 src->s6_addr32[0], src->s6_addr32[1],
1741 src->s6_addr32[2], src->s6_addr32[3],
1742 ntohs(inet_rsk(req)->loc_port),
1743 dest->s6_addr32[0], dest->s6_addr32[1],
1744 dest->s6_addr32[2], dest->s6_addr32[3],
1745 ntohs(inet_rsk(req)->rmt_port),
1747 0,0, /* could print option size, but that is af dependent. */
1748 1, /* timers active (only the expire timer) */
1749 jiffies_to_clock_t(ttd),
1751 from_kuid_munged(seq_user_ns(seq), uid),
1752 0, /* non standard timer */
1753 0, /* open_requests have no inode */
1757 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1759 const struct in6_addr *dest, *src;
1762 unsigned long timer_expires;
1763 const struct inet_sock *inet = inet_sk(sp);
1764 const struct tcp_sock *tp = tcp_sk(sp);
1765 const struct inet_connection_sock *icsk = inet_csk(sp);
1766 const struct ipv6_pinfo *np = inet6_sk(sp);
1769 src = &np->rcv_saddr;
1770 destp = ntohs(inet->inet_dport);
1771 srcp = ntohs(inet->inet_sport);
1773 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1775 timer_expires = icsk->icsk_timeout;
1776 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1778 timer_expires = icsk->icsk_timeout;
1779 } else if (timer_pending(&sp->sk_timer)) {
1781 timer_expires = sp->sk_timer.expires;
1784 timer_expires = jiffies;
1788 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1789 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1791 src->s6_addr32[0], src->s6_addr32[1],
1792 src->s6_addr32[2], src->s6_addr32[3], srcp,
1793 dest->s6_addr32[0], dest->s6_addr32[1],
1794 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1796 tp->write_seq-tp->snd_una,
1797 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1799 jiffies_delta_to_clock_t(timer_expires - jiffies),
1800 icsk->icsk_retransmits,
1801 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1802 icsk->icsk_probes_out,
1804 atomic_read(&sp->sk_refcnt), sp,
1805 jiffies_to_clock_t(icsk->icsk_rto),
1806 jiffies_to_clock_t(icsk->icsk_ack.ato),
1807 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1809 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1813 static void get_timewait6_sock(struct seq_file *seq,
1814 struct inet_timewait_sock *tw, int i)
1816 const struct in6_addr *dest, *src;
1818 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1819 long delta = tw->tw_ttd - jiffies;
1821 dest = &tw6->tw_v6_daddr;
1822 src = &tw6->tw_v6_rcv_saddr;
1823 destp = ntohs(tw->tw_dport);
1824 srcp = ntohs(tw->tw_sport);
1827 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1828 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1830 src->s6_addr32[0], src->s6_addr32[1],
1831 src->s6_addr32[2], src->s6_addr32[3], srcp,
1832 dest->s6_addr32[0], dest->s6_addr32[1],
1833 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1834 tw->tw_substate, 0, 0,
1835 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1836 atomic_read(&tw->tw_refcnt), tw);
1839 static int tcp6_seq_show(struct seq_file *seq, void *v)
1841 struct tcp_iter_state *st;
1843 if (v == SEQ_START_TOKEN) {
1848 "st tx_queue rx_queue tr tm->when retrnsmt"
1849 " uid timeout inode\n");
1854 switch (st->state) {
1855 case TCP_SEQ_STATE_LISTENING:
1856 case TCP_SEQ_STATE_ESTABLISHED:
1857 get_tcp6_sock(seq, v, st->num);
1859 case TCP_SEQ_STATE_OPENREQ:
1860 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1862 case TCP_SEQ_STATE_TIME_WAIT:
1863 get_timewait6_sock(seq, v, st->num);
1870 static const struct file_operations tcp6_afinfo_seq_fops = {
1871 .owner = THIS_MODULE,
1872 .open = tcp_seq_open,
1874 .llseek = seq_lseek,
1875 .release = seq_release_net
1878 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1881 .seq_fops = &tcp6_afinfo_seq_fops,
1883 .show = tcp6_seq_show,
1887 int __net_init tcp6_proc_init(struct net *net)
1889 return tcp_proc_register(net, &tcp6_seq_afinfo);
1892 void tcp6_proc_exit(struct net *net)
1894 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1898 static void tcp_v6_clear_sk(struct sock *sk, int size)
1900 struct inet_sock *inet = inet_sk(sk);
1902 /* we do not want to clear pinet6 field, because of RCU lookups */
1903 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1905 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1906 memset(&inet->pinet6 + 1, 0, size);
1909 struct proto tcpv6_prot = {
1911 .owner = THIS_MODULE,
1913 .connect = tcp_v6_connect,
1914 .disconnect = tcp_disconnect,
1915 .accept = inet_csk_accept,
1917 .init = tcp_v6_init_sock,
1918 .destroy = tcp_v6_destroy_sock,
1919 .shutdown = tcp_shutdown,
1920 .setsockopt = tcp_setsockopt,
1921 .getsockopt = tcp_getsockopt,
1922 .recvmsg = tcp_recvmsg,
1923 .sendmsg = tcp_sendmsg,
1924 .sendpage = tcp_sendpage,
1925 .backlog_rcv = tcp_v6_do_rcv,
1926 .release_cb = tcp_release_cb,
1927 .hash = tcp_v6_hash,
1928 .unhash = inet_unhash,
1929 .get_port = inet_csk_get_port,
1930 .enter_memory_pressure = tcp_enter_memory_pressure,
1931 .sockets_allocated = &tcp_sockets_allocated,
1932 .memory_allocated = &tcp_memory_allocated,
1933 .memory_pressure = &tcp_memory_pressure,
1934 .orphan_count = &tcp_orphan_count,
1935 .sysctl_wmem = sysctl_tcp_wmem,
1936 .sysctl_rmem = sysctl_tcp_rmem,
1937 .max_header = MAX_TCP_HEADER,
1938 .obj_size = sizeof(struct tcp6_sock),
1939 .slab_flags = SLAB_DESTROY_BY_RCU,
1940 .twsk_prot = &tcp6_timewait_sock_ops,
1941 .rsk_prot = &tcp6_request_sock_ops,
1942 .h.hashinfo = &tcp_hashinfo,
1943 .no_autobind = true,
1944 #ifdef CONFIG_COMPAT
1945 .compat_setsockopt = compat_tcp_setsockopt,
1946 .compat_getsockopt = compat_tcp_getsockopt,
1948 #ifdef CONFIG_MEMCG_KMEM
1949 .proto_cgroup = tcp_proto_cgroup,
1951 .clear_sk = tcp_v6_clear_sk,
1954 static const struct inet6_protocol tcpv6_protocol = {
1955 .early_demux = tcp_v6_early_demux,
1956 .handler = tcp_v6_rcv,
1957 .err_handler = tcp_v6_err,
1958 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1961 static struct inet_protosw tcpv6_protosw = {
1962 .type = SOCK_STREAM,
1963 .protocol = IPPROTO_TCP,
1964 .prot = &tcpv6_prot,
1965 .ops = &inet6_stream_ops,
1967 .flags = INET_PROTOSW_PERMANENT |
1971 static int __net_init tcpv6_net_init(struct net *net)
1973 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1974 SOCK_RAW, IPPROTO_TCP, net);
1977 static void __net_exit tcpv6_net_exit(struct net *net)
1979 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1982 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1984 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1987 static struct pernet_operations tcpv6_net_ops = {
1988 .init = tcpv6_net_init,
1989 .exit = tcpv6_net_exit,
1990 .exit_batch = tcpv6_net_exit_batch,
1993 int __init tcpv6_init(void)
1997 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2001 /* register inet6 protocol */
2002 ret = inet6_register_protosw(&tcpv6_protosw);
2004 goto out_tcpv6_protocol;
2006 ret = register_pernet_subsys(&tcpv6_net_ops);
2008 goto out_tcpv6_protosw;
2013 inet6_unregister_protosw(&tcpv6_protosw);
2015 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2019 void tcpv6_exit(void)
2021 unregister_pernet_subsys(&tcpv6_net_ops);
2022 inet6_unregister_protosw(&tcpv6_protosw);
2023 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);