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>
66 #include <net/busy_poll.h>
68 #include <asm/uaccess.h>
70 #include <linux/proc_fs.h>
71 #include <linux/seq_file.h>
73 #include <linux/crypto.h>
74 #include <linux/scatterlist.h>
76 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
77 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
78 struct request_sock *req);
80 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
82 static const struct inet_connection_sock_af_ops ipv6_mapped;
83 static const struct inet_connection_sock_af_ops ipv6_specific;
84 #ifdef CONFIG_TCP_MD5SIG
85 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
86 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
88 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
89 const struct in6_addr *addr)
95 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
97 struct dst_entry *dst = skb_dst(skb);
98 const struct rt6_info *rt = (const struct rt6_info *)dst;
102 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
104 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
107 static void tcp_v6_hash(struct sock *sk)
109 if (sk->sk_state != TCP_CLOSE) {
110 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
115 __inet6_hash(sk, NULL);
120 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
122 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
123 ipv6_hdr(skb)->saddr.s6_addr32,
125 tcp_hdr(skb)->source);
128 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
131 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
132 struct inet_sock *inet = inet_sk(sk);
133 struct inet_connection_sock *icsk = inet_csk(sk);
134 struct ipv6_pinfo *np = inet6_sk(sk);
135 struct tcp_sock *tp = tcp_sk(sk);
136 struct in6_addr *saddr = NULL, *final_p, final;
139 struct dst_entry *dst;
143 if (addr_len < SIN6_LEN_RFC2133)
146 if (usin->sin6_family != AF_INET6)
147 return -EAFNOSUPPORT;
149 memset(&fl6, 0, sizeof(fl6));
152 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
153 IP6_ECN_flow_init(fl6.flowlabel);
154 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
155 struct ip6_flowlabel *flowlabel;
156 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
157 if (flowlabel == NULL)
159 usin->sin6_addr = flowlabel->dst;
160 fl6_sock_release(flowlabel);
165 * connect() to INADDR_ANY means loopback (BSD'ism).
168 if(ipv6_addr_any(&usin->sin6_addr))
169 usin->sin6_addr.s6_addr[15] = 0x1;
171 addr_type = ipv6_addr_type(&usin->sin6_addr);
173 if(addr_type & IPV6_ADDR_MULTICAST)
176 if (addr_type&IPV6_ADDR_LINKLOCAL) {
177 if (addr_len >= sizeof(struct sockaddr_in6) &&
178 usin->sin6_scope_id) {
179 /* If interface is set while binding, indices
182 if (sk->sk_bound_dev_if &&
183 sk->sk_bound_dev_if != usin->sin6_scope_id)
186 sk->sk_bound_dev_if = usin->sin6_scope_id;
189 /* Connect to link-local address requires an interface */
190 if (!sk->sk_bound_dev_if)
194 if (tp->rx_opt.ts_recent_stamp &&
195 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
196 tp->rx_opt.ts_recent = 0;
197 tp->rx_opt.ts_recent_stamp = 0;
201 np->daddr = usin->sin6_addr;
202 np->flow_label = fl6.flowlabel;
208 if (addr_type == IPV6_ADDR_MAPPED) {
209 u32 exthdrlen = icsk->icsk_ext_hdr_len;
210 struct sockaddr_in sin;
212 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
214 if (__ipv6_only_sock(sk))
217 sin.sin_family = AF_INET;
218 sin.sin_port = usin->sin6_port;
219 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
221 icsk->icsk_af_ops = &ipv6_mapped;
222 sk->sk_backlog_rcv = tcp_v4_do_rcv;
223 #ifdef CONFIG_TCP_MD5SIG
224 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
227 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
230 icsk->icsk_ext_hdr_len = exthdrlen;
231 icsk->icsk_af_ops = &ipv6_specific;
232 sk->sk_backlog_rcv = tcp_v6_do_rcv;
233 #ifdef CONFIG_TCP_MD5SIG
234 tp->af_specific = &tcp_sock_ipv6_specific;
238 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
239 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
246 if (!ipv6_addr_any(&np->rcv_saddr))
247 saddr = &np->rcv_saddr;
249 fl6.flowi6_proto = IPPROTO_TCP;
250 fl6.daddr = np->daddr;
251 fl6.saddr = saddr ? *saddr : np->saddr;
252 fl6.flowi6_oif = sk->sk_bound_dev_if;
253 fl6.flowi6_mark = sk->sk_mark;
254 fl6.fl6_dport = usin->sin6_port;
255 fl6.fl6_sport = inet->inet_sport;
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.fl6_dport = t1->dest;
796 fl6.fl6_sport = t1->source;
797 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
799 /* Pass a socket to ip6_dst_lookup either it is for RST
800 * Underlying function will use this to retrieve the network
803 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
805 skb_dst_set(buff, dst);
806 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
807 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
809 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
816 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
818 const struct tcphdr *th = tcp_hdr(skb);
819 u32 seq = 0, ack_seq = 0;
820 struct tcp_md5sig_key *key = NULL;
821 #ifdef CONFIG_TCP_MD5SIG
822 const __u8 *hash_location = NULL;
823 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
824 unsigned char newhash[16];
826 struct sock *sk1 = NULL;
832 if (!ipv6_unicast_destination(skb))
835 #ifdef CONFIG_TCP_MD5SIG
836 hash_location = tcp_parse_md5sig_option(th);
837 if (!sk && hash_location) {
839 * active side is lost. Try to find listening socket through
840 * source port, and then find md5 key through listening socket.
841 * we are not loose security here:
842 * Incoming packet is checked with md5 hash with finding key,
843 * no RST generated if md5 hash doesn't match.
845 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
846 &tcp_hashinfo, &ipv6h->saddr,
847 th->source, &ipv6h->daddr,
848 ntohs(th->source), inet6_iif(skb));
853 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
857 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
858 if (genhash || memcmp(hash_location, newhash, 16) != 0)
861 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
866 seq = ntohl(th->ack_seq);
868 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
871 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, key, 1, 0);
873 #ifdef CONFIG_TCP_MD5SIG
882 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
883 u32 win, u32 tsval, u32 tsecr,
884 struct tcp_md5sig_key *key, u8 tclass)
886 tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, key, 0, tclass);
889 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
891 struct inet_timewait_sock *tw = inet_twsk(sk);
892 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
894 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
895 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
896 tcp_time_stamp + tcptw->tw_ts_offset,
897 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
903 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
904 struct request_sock *req)
906 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
907 req->rcv_wnd, tcp_time_stamp, req->ts_recent,
908 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
912 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
914 struct request_sock *req, **prev;
915 const struct tcphdr *th = tcp_hdr(skb);
918 /* Find possible connection requests. */
919 req = inet6_csk_search_req(sk, &prev, th->source,
920 &ipv6_hdr(skb)->saddr,
921 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
923 return tcp_check_req(sk, skb, req, prev, false);
925 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
926 &ipv6_hdr(skb)->saddr, th->source,
927 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
930 if (nsk->sk_state != TCP_TIME_WAIT) {
934 inet_twsk_put(inet_twsk(nsk));
938 #ifdef CONFIG_SYN_COOKIES
940 sk = cookie_v6_check(sk, skb);
945 /* FIXME: this is substantially similar to the ipv4 code.
946 * Can some kind of merge be done? -- erics
948 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
950 struct tcp_options_received tmp_opt;
951 struct request_sock *req;
952 struct inet6_request_sock *treq;
953 struct ipv6_pinfo *np = inet6_sk(sk);
954 struct tcp_sock *tp = tcp_sk(sk);
955 __u32 isn = TCP_SKB_CB(skb)->when;
956 struct dst_entry *dst = NULL;
958 bool want_cookie = false;
960 if (skb->protocol == htons(ETH_P_IP))
961 return tcp_v4_conn_request(sk, skb);
963 if (!ipv6_unicast_destination(skb))
966 if ((sysctl_tcp_syncookies == 2 ||
967 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;
1005 /* So that link locals have meaning */
1006 if (!sk->sk_bound_dev_if &&
1007 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1008 treq->iif = inet6_iif(skb);
1011 if (ipv6_opt_accepted(sk, skb) ||
1012 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1013 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1014 atomic_inc(&skb->users);
1015 treq->pktopts = skb;
1019 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1020 req->cookie_ts = tmp_opt.tstamp_ok;
1024 /* VJ's idea. We save last timestamp seen
1025 * from the destination in peer table, when entering
1026 * state TIME-WAIT, and check against it before
1027 * accepting new connection request.
1029 * If "isn" is not zero, this request hit alive
1030 * timewait bucket, so that all the necessary checks
1031 * are made in the function processing timewait state.
1033 if (tmp_opt.saw_tstamp &&
1034 tcp_death_row.sysctl_tw_recycle &&
1035 (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1036 if (!tcp_peer_is_proven(req, dst, true)) {
1037 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1038 goto drop_and_release;
1041 /* Kill the following clause, if you dislike this way. */
1042 else if (!sysctl_tcp_syncookies &&
1043 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1044 (sysctl_max_syn_backlog >> 2)) &&
1045 !tcp_peer_is_proven(req, dst, false)) {
1046 /* Without syncookies last quarter of
1047 * backlog is filled with destinations,
1048 * proven to be alive.
1049 * It means that we continue to communicate
1050 * to destinations, already remembered
1051 * to the moment of synflood.
1053 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1054 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1055 goto drop_and_release;
1058 isn = tcp_v6_init_sequence(skb);
1061 tcp_rsk(req)->snt_isn = isn;
1063 if (security_inet_conn_request(sk, skb, req))
1064 goto drop_and_release;
1066 if (tcp_v6_send_synack(sk, dst, &fl6, req,
1067 skb_get_queue_mapping(skb)) ||
1071 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1072 tcp_rsk(req)->listener = NULL;
1073 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1081 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1082 return 0; /* don't send reset */
1085 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1086 struct request_sock *req,
1087 struct dst_entry *dst)
1089 struct inet6_request_sock *treq;
1090 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1091 struct tcp6_sock *newtcp6sk;
1092 struct inet_sock *newinet;
1093 struct tcp_sock *newtp;
1095 #ifdef CONFIG_TCP_MD5SIG
1096 struct tcp_md5sig_key *key;
1100 if (skb->protocol == htons(ETH_P_IP)) {
1105 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1110 newtcp6sk = (struct tcp6_sock *)newsk;
1111 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1113 newinet = inet_sk(newsk);
1114 newnp = inet6_sk(newsk);
1115 newtp = tcp_sk(newsk);
1117 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1119 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1121 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1123 newnp->rcv_saddr = newnp->saddr;
1125 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1126 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1127 #ifdef CONFIG_TCP_MD5SIG
1128 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1131 newnp->ipv6_ac_list = NULL;
1132 newnp->ipv6_fl_list = NULL;
1133 newnp->pktoptions = NULL;
1135 newnp->mcast_oif = inet6_iif(skb);
1136 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1137 newnp->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
1140 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1141 * here, tcp_create_openreq_child now does this for us, see the comment in
1142 * that function for the gory details. -acme
1145 /* It is tricky place. Until this moment IPv4 tcp
1146 worked with IPv6 icsk.icsk_af_ops.
1149 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1154 treq = inet6_rsk(req);
1156 if (sk_acceptq_is_full(sk))
1160 dst = inet6_csk_route_req(sk, &fl6, req);
1165 newsk = tcp_create_openreq_child(sk, req, skb);
1170 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1171 * count here, tcp_create_openreq_child now does this for us, see the
1172 * comment in that function for the gory details. -acme
1175 newsk->sk_gso_type = SKB_GSO_TCPV6;
1176 __ip6_dst_store(newsk, dst, NULL, NULL);
1177 inet6_sk_rx_dst_set(newsk, skb);
1179 newtcp6sk = (struct tcp6_sock *)newsk;
1180 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1182 newtp = tcp_sk(newsk);
1183 newinet = inet_sk(newsk);
1184 newnp = inet6_sk(newsk);
1186 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1188 newnp->daddr = treq->rmt_addr;
1189 newnp->saddr = treq->loc_addr;
1190 newnp->rcv_saddr = treq->loc_addr;
1191 newsk->sk_bound_dev_if = treq->iif;
1193 /* Now IPv6 options...
1195 First: no IPv4 options.
1197 newinet->inet_opt = NULL;
1198 newnp->ipv6_ac_list = NULL;
1199 newnp->ipv6_fl_list = NULL;
1202 newnp->rxopt.all = np->rxopt.all;
1204 /* Clone pktoptions received with SYN */
1205 newnp->pktoptions = NULL;
1206 if (treq->pktopts != NULL) {
1207 newnp->pktoptions = skb_clone(treq->pktopts,
1208 sk_gfp_atomic(sk, GFP_ATOMIC));
1209 consume_skb(treq->pktopts);
1210 treq->pktopts = NULL;
1211 if (newnp->pktoptions)
1212 skb_set_owner_r(newnp->pktoptions, newsk);
1215 newnp->mcast_oif = inet6_iif(skb);
1216 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1217 newnp->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
1219 /* Clone native IPv6 options from listening socket (if any)
1221 Yes, keeping reference count would be much more clever,
1222 but we make one more one thing there: reattach optmem
1226 newnp->opt = ipv6_dup_options(newsk, np->opt);
1228 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1230 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1231 newnp->opt->opt_flen);
1233 tcp_mtup_init(newsk);
1234 tcp_sync_mss(newsk, dst_mtu(dst));
1235 newtp->advmss = dst_metric_advmss(dst);
1236 if (tcp_sk(sk)->rx_opt.user_mss &&
1237 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1238 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1240 tcp_initialize_rcv_mss(newsk);
1242 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1243 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1245 #ifdef CONFIG_TCP_MD5SIG
1246 /* Copy over the MD5 key from the original socket */
1247 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1248 /* We're using one, so create a matching key
1249 * on the newsk structure. If we fail to get
1250 * memory, then we end up not copying the key
1253 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1254 AF_INET6, key->key, key->keylen,
1255 sk_gfp_atomic(sk, GFP_ATOMIC));
1259 if (__inet_inherit_port(sk, newsk) < 0) {
1260 inet_csk_prepare_forced_close(newsk);
1264 __inet6_hash(newsk, NULL);
1269 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1273 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1277 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1279 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1280 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1281 &ipv6_hdr(skb)->daddr, skb->csum)) {
1282 skb->ip_summed = CHECKSUM_UNNECESSARY;
1287 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1288 &ipv6_hdr(skb)->saddr,
1289 &ipv6_hdr(skb)->daddr, 0));
1291 if (skb->len <= 76) {
1292 return __skb_checksum_complete(skb);
1297 /* The socket must have it's spinlock held when we get
1300 * We have a potential double-lock case here, so even when
1301 * doing backlog processing we use the BH locking scheme.
1302 * This is because we cannot sleep with the original spinlock
1305 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1307 struct ipv6_pinfo *np = inet6_sk(sk);
1308 struct tcp_sock *tp;
1309 struct sk_buff *opt_skb = NULL;
1311 /* Imagine: socket is IPv6. IPv4 packet arrives,
1312 goes to IPv4 receive handler and backlogged.
1313 From backlog it always goes here. Kerboom...
1314 Fortunately, tcp_rcv_established and rcv_established
1315 handle them correctly, but it is not case with
1316 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1319 if (skb->protocol == htons(ETH_P_IP))
1320 return tcp_v4_do_rcv(sk, skb);
1322 #ifdef CONFIG_TCP_MD5SIG
1323 if (tcp_v6_inbound_md5_hash (sk, skb))
1327 if (sk_filter(sk, skb))
1331 * socket locking is here for SMP purposes as backlog rcv
1332 * is currently called with bh processing disabled.
1335 /* Do Stevens' IPV6_PKTOPTIONS.
1337 Yes, guys, it is the only place in our code, where we
1338 may make it not affecting IPv4.
1339 The rest of code is protocol independent,
1340 and I do not like idea to uglify IPv4.
1342 Actually, all the idea behind IPV6_PKTOPTIONS
1343 looks not very well thought. For now we latch
1344 options, received in the last packet, enqueued
1345 by tcp. Feel free to propose better solution.
1349 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1351 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1352 struct dst_entry *dst = sk->sk_rx_dst;
1354 sock_rps_save_rxhash(sk, skb);
1356 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1357 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1359 sk->sk_rx_dst = NULL;
1363 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1366 goto ipv6_pktoptions;
1370 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1373 if (sk->sk_state == TCP_LISTEN) {
1374 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1379 * Queue it on the new socket if the new socket is active,
1380 * otherwise we just shortcircuit this and continue with
1384 sock_rps_save_rxhash(nsk, skb);
1385 if (tcp_child_process(sk, nsk, skb))
1388 __kfree_skb(opt_skb);
1392 sock_rps_save_rxhash(sk, skb);
1394 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1397 goto ipv6_pktoptions;
1401 tcp_v6_send_reset(sk, skb);
1404 __kfree_skb(opt_skb);
1408 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1409 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1414 /* Do you ask, what is it?
1416 1. skb was enqueued by tcp.
1417 2. skb is added to tail of read queue, rather than out of order.
1418 3. socket is not in passive state.
1419 4. Finally, it really contains options, which user wants to receive.
1422 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1423 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1424 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1425 np->mcast_oif = inet6_iif(opt_skb);
1426 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1427 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1428 if (np->rxopt.bits.rxtclass)
1429 np->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
1430 if (ipv6_opt_accepted(sk, opt_skb)) {
1431 skb_set_owner_r(opt_skb, sk);
1432 opt_skb = xchg(&np->pktoptions, opt_skb);
1434 __kfree_skb(opt_skb);
1435 opt_skb = xchg(&np->pktoptions, NULL);
1443 static int tcp_v6_rcv(struct sk_buff *skb)
1445 const struct tcphdr *th;
1446 const struct ipv6hdr *hdr;
1449 struct net *net = dev_net(skb->dev);
1451 if (skb->pkt_type != PACKET_HOST)
1455 * Count it even if it's bad.
1457 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1459 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1464 if (th->doff < sizeof(struct tcphdr)/4)
1466 if (!pskb_may_pull(skb, th->doff*4))
1469 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1473 hdr = ipv6_hdr(skb);
1474 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1475 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1476 skb->len - th->doff*4);
1477 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1478 TCP_SKB_CB(skb)->when = 0;
1479 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1480 TCP_SKB_CB(skb)->sacked = 0;
1482 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1487 if (sk->sk_state == TCP_TIME_WAIT)
1490 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1491 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1492 goto discard_and_relse;
1495 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1496 goto discard_and_relse;
1498 if (sk_filter(sk, skb))
1499 goto discard_and_relse;
1501 sk_mark_napi_id(sk, skb);
1504 bh_lock_sock_nested(sk);
1506 if (!sock_owned_by_user(sk)) {
1507 #ifdef CONFIG_NET_DMA
1508 struct tcp_sock *tp = tcp_sk(sk);
1509 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1510 tp->ucopy.dma_chan = net_dma_find_channel();
1511 if (tp->ucopy.dma_chan)
1512 ret = tcp_v6_do_rcv(sk, skb);
1516 if (!tcp_prequeue(sk, skb))
1517 ret = tcp_v6_do_rcv(sk, skb);
1519 } else if (unlikely(sk_add_backlog(sk, skb,
1520 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1522 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1523 goto discard_and_relse;
1528 return ret ? -1 : 0;
1531 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1534 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1536 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1538 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1540 tcp_v6_send_reset(NULL, skb);
1552 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1553 inet_twsk_put(inet_twsk(sk));
1557 if (skb->len < (th->doff<<2)) {
1558 inet_twsk_put(inet_twsk(sk));
1561 if (tcp_checksum_complete(skb)) {
1562 inet_twsk_put(inet_twsk(sk));
1566 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1571 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1572 &ipv6_hdr(skb)->saddr, th->source,
1573 &ipv6_hdr(skb)->daddr,
1574 ntohs(th->dest), inet6_iif(skb));
1576 struct inet_timewait_sock *tw = inet_twsk(sk);
1577 inet_twsk_deschedule(tw, &tcp_death_row);
1582 /* Fall through to ACK */
1585 tcp_v6_timewait_ack(sk, skb);
1589 case TCP_TW_SUCCESS:;
1594 static void tcp_v6_early_demux(struct sk_buff *skb)
1596 const struct ipv6hdr *hdr;
1597 const struct tcphdr *th;
1600 if (skb->pkt_type != PACKET_HOST)
1603 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1606 hdr = ipv6_hdr(skb);
1609 if (th->doff < sizeof(struct tcphdr) / 4)
1612 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1613 &hdr->saddr, th->source,
1614 &hdr->daddr, ntohs(th->dest),
1618 skb->destructor = sock_edemux;
1619 if (sk->sk_state != TCP_TIME_WAIT) {
1620 struct dst_entry *dst = sk->sk_rx_dst;
1623 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1625 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1626 skb_dst_set_noref(skb, dst);
1631 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1632 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1633 .twsk_unique = tcp_twsk_unique,
1634 .twsk_destructor= tcp_twsk_destructor,
1637 static const struct inet_connection_sock_af_ops ipv6_specific = {
1638 .queue_xmit = inet6_csk_xmit,
1639 .send_check = tcp_v6_send_check,
1640 .rebuild_header = inet6_sk_rebuild_header,
1641 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1642 .conn_request = tcp_v6_conn_request,
1643 .syn_recv_sock = tcp_v6_syn_recv_sock,
1644 .net_header_len = sizeof(struct ipv6hdr),
1645 .net_frag_header_len = sizeof(struct frag_hdr),
1646 .setsockopt = ipv6_setsockopt,
1647 .getsockopt = ipv6_getsockopt,
1648 .addr2sockaddr = inet6_csk_addr2sockaddr,
1649 .sockaddr_len = sizeof(struct sockaddr_in6),
1650 .bind_conflict = inet6_csk_bind_conflict,
1651 #ifdef CONFIG_COMPAT
1652 .compat_setsockopt = compat_ipv6_setsockopt,
1653 .compat_getsockopt = compat_ipv6_getsockopt,
1657 #ifdef CONFIG_TCP_MD5SIG
1658 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1659 .md5_lookup = tcp_v6_md5_lookup,
1660 .calc_md5_hash = tcp_v6_md5_hash_skb,
1661 .md5_parse = tcp_v6_parse_md5_keys,
1666 * TCP over IPv4 via INET6 API
1669 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1670 .queue_xmit = ip_queue_xmit,
1671 .send_check = tcp_v4_send_check,
1672 .rebuild_header = inet_sk_rebuild_header,
1673 .sk_rx_dst_set = inet_sk_rx_dst_set,
1674 .conn_request = tcp_v6_conn_request,
1675 .syn_recv_sock = tcp_v6_syn_recv_sock,
1676 .net_header_len = sizeof(struct iphdr),
1677 .setsockopt = ipv6_setsockopt,
1678 .getsockopt = ipv6_getsockopt,
1679 .addr2sockaddr = inet6_csk_addr2sockaddr,
1680 .sockaddr_len = sizeof(struct sockaddr_in6),
1681 .bind_conflict = inet6_csk_bind_conflict,
1682 #ifdef CONFIG_COMPAT
1683 .compat_setsockopt = compat_ipv6_setsockopt,
1684 .compat_getsockopt = compat_ipv6_getsockopt,
1688 #ifdef CONFIG_TCP_MD5SIG
1689 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1690 .md5_lookup = tcp_v4_md5_lookup,
1691 .calc_md5_hash = tcp_v4_md5_hash_skb,
1692 .md5_parse = tcp_v6_parse_md5_keys,
1696 /* NOTE: A lot of things set to zero explicitly by call to
1697 * sk_alloc() so need not be done here.
1699 static int tcp_v6_init_sock(struct sock *sk)
1701 struct inet_connection_sock *icsk = inet_csk(sk);
1705 icsk->icsk_af_ops = &ipv6_specific;
1707 #ifdef CONFIG_TCP_MD5SIG
1708 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1714 static void tcp_v6_destroy_sock(struct sock *sk)
1716 tcp_v4_destroy_sock(sk);
1717 inet6_destroy_sock(sk);
1720 #ifdef CONFIG_PROC_FS
1721 /* Proc filesystem TCPv6 sock list dumping. */
1722 static void get_openreq6(struct seq_file *seq,
1723 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1725 int ttd = req->expires - jiffies;
1726 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1727 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1733 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1734 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1736 src->s6_addr32[0], src->s6_addr32[1],
1737 src->s6_addr32[2], src->s6_addr32[3],
1738 ntohs(inet_rsk(req)->loc_port),
1739 dest->s6_addr32[0], dest->s6_addr32[1],
1740 dest->s6_addr32[2], dest->s6_addr32[3],
1741 ntohs(inet_rsk(req)->rmt_port),
1743 0,0, /* could print option size, but that is af dependent. */
1744 1, /* timers active (only the expire timer) */
1745 jiffies_to_clock_t(ttd),
1747 from_kuid_munged(seq_user_ns(seq), uid),
1748 0, /* non standard timer */
1749 0, /* open_requests have no inode */
1753 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1755 const struct in6_addr *dest, *src;
1758 unsigned long timer_expires;
1759 const struct inet_sock *inet = inet_sk(sp);
1760 const struct tcp_sock *tp = tcp_sk(sp);
1761 const struct inet_connection_sock *icsk = inet_csk(sp);
1762 const struct ipv6_pinfo *np = inet6_sk(sp);
1765 src = &np->rcv_saddr;
1766 destp = ntohs(inet->inet_dport);
1767 srcp = ntohs(inet->inet_sport);
1769 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1771 timer_expires = icsk->icsk_timeout;
1772 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1774 timer_expires = icsk->icsk_timeout;
1775 } else if (timer_pending(&sp->sk_timer)) {
1777 timer_expires = sp->sk_timer.expires;
1780 timer_expires = jiffies;
1784 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1785 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1787 src->s6_addr32[0], src->s6_addr32[1],
1788 src->s6_addr32[2], src->s6_addr32[3], srcp,
1789 dest->s6_addr32[0], dest->s6_addr32[1],
1790 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1792 tp->write_seq-tp->snd_una,
1793 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1795 jiffies_delta_to_clock_t(timer_expires - jiffies),
1796 icsk->icsk_retransmits,
1797 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1798 icsk->icsk_probes_out,
1800 atomic_read(&sp->sk_refcnt), sp,
1801 jiffies_to_clock_t(icsk->icsk_rto),
1802 jiffies_to_clock_t(icsk->icsk_ack.ato),
1803 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1805 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1809 static void get_timewait6_sock(struct seq_file *seq,
1810 struct inet_timewait_sock *tw, int i)
1812 const struct in6_addr *dest, *src;
1814 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1815 long delta = tw->tw_ttd - jiffies;
1817 dest = &tw6->tw_v6_daddr;
1818 src = &tw6->tw_v6_rcv_saddr;
1819 destp = ntohs(tw->tw_dport);
1820 srcp = ntohs(tw->tw_sport);
1823 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1824 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1826 src->s6_addr32[0], src->s6_addr32[1],
1827 src->s6_addr32[2], src->s6_addr32[3], srcp,
1828 dest->s6_addr32[0], dest->s6_addr32[1],
1829 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1830 tw->tw_substate, 0, 0,
1831 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1832 atomic_read(&tw->tw_refcnt), tw);
1835 static int tcp6_seq_show(struct seq_file *seq, void *v)
1837 struct tcp_iter_state *st;
1839 if (v == SEQ_START_TOKEN) {
1844 "st tx_queue rx_queue tr tm->when retrnsmt"
1845 " uid timeout inode\n");
1850 switch (st->state) {
1851 case TCP_SEQ_STATE_LISTENING:
1852 case TCP_SEQ_STATE_ESTABLISHED:
1853 get_tcp6_sock(seq, v, st->num);
1855 case TCP_SEQ_STATE_OPENREQ:
1856 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1858 case TCP_SEQ_STATE_TIME_WAIT:
1859 get_timewait6_sock(seq, v, st->num);
1866 static const struct file_operations tcp6_afinfo_seq_fops = {
1867 .owner = THIS_MODULE,
1868 .open = tcp_seq_open,
1870 .llseek = seq_lseek,
1871 .release = seq_release_net
1874 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1877 .seq_fops = &tcp6_afinfo_seq_fops,
1879 .show = tcp6_seq_show,
1883 int __net_init tcp6_proc_init(struct net *net)
1885 return tcp_proc_register(net, &tcp6_seq_afinfo);
1888 void tcp6_proc_exit(struct net *net)
1890 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1894 static void tcp_v6_clear_sk(struct sock *sk, int size)
1896 struct inet_sock *inet = inet_sk(sk);
1898 /* we do not want to clear pinet6 field, because of RCU lookups */
1899 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1901 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1902 memset(&inet->pinet6 + 1, 0, size);
1905 struct proto tcpv6_prot = {
1907 .owner = THIS_MODULE,
1909 .connect = tcp_v6_connect,
1910 .disconnect = tcp_disconnect,
1911 .accept = inet_csk_accept,
1913 .init = tcp_v6_init_sock,
1914 .destroy = tcp_v6_destroy_sock,
1915 .shutdown = tcp_shutdown,
1916 .setsockopt = tcp_setsockopt,
1917 .getsockopt = tcp_getsockopt,
1918 .recvmsg = tcp_recvmsg,
1919 .sendmsg = tcp_sendmsg,
1920 .sendpage = tcp_sendpage,
1921 .backlog_rcv = tcp_v6_do_rcv,
1922 .release_cb = tcp_release_cb,
1923 .mtu_reduced = tcp_v6_mtu_reduced,
1924 .hash = tcp_v6_hash,
1925 .unhash = inet_unhash,
1926 .get_port = inet_csk_get_port,
1927 .enter_memory_pressure = tcp_enter_memory_pressure,
1928 .stream_memory_free = tcp_stream_memory_free,
1929 .sockets_allocated = &tcp_sockets_allocated,
1930 .memory_allocated = &tcp_memory_allocated,
1931 .memory_pressure = &tcp_memory_pressure,
1932 .orphan_count = &tcp_orphan_count,
1933 .sysctl_wmem = sysctl_tcp_wmem,
1934 .sysctl_rmem = sysctl_tcp_rmem,
1935 .max_header = MAX_TCP_HEADER,
1936 .obj_size = sizeof(struct tcp6_sock),
1937 .slab_flags = SLAB_DESTROY_BY_RCU,
1938 .twsk_prot = &tcp6_timewait_sock_ops,
1939 .rsk_prot = &tcp6_request_sock_ops,
1940 .h.hashinfo = &tcp_hashinfo,
1941 .no_autobind = true,
1942 #ifdef CONFIG_COMPAT
1943 .compat_setsockopt = compat_tcp_setsockopt,
1944 .compat_getsockopt = compat_tcp_getsockopt,
1946 #ifdef CONFIG_MEMCG_KMEM
1947 .proto_cgroup = tcp_proto_cgroup,
1949 .clear_sk = tcp_v6_clear_sk,
1952 static const struct inet6_protocol tcpv6_protocol = {
1953 .early_demux = tcp_v6_early_demux,
1954 .handler = tcp_v6_rcv,
1955 .err_handler = tcp_v6_err,
1956 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1959 static struct inet_protosw tcpv6_protosw = {
1960 .type = SOCK_STREAM,
1961 .protocol = IPPROTO_TCP,
1962 .prot = &tcpv6_prot,
1963 .ops = &inet6_stream_ops,
1965 .flags = INET_PROTOSW_PERMANENT |
1969 static int __net_init tcpv6_net_init(struct net *net)
1971 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1972 SOCK_RAW, IPPROTO_TCP, net);
1975 static void __net_exit tcpv6_net_exit(struct net *net)
1977 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1980 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1982 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1985 static struct pernet_operations tcpv6_net_ops = {
1986 .init = tcpv6_net_init,
1987 .exit = tcpv6_net_exit,
1988 .exit_batch = tcpv6_net_exit_batch,
1991 int __init tcpv6_init(void)
1995 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1999 /* register inet6 protocol */
2000 ret = inet6_register_protosw(&tcpv6_protosw);
2002 goto out_tcpv6_protocol;
2004 ret = register_pernet_subsys(&tcpv6_net_ops);
2006 goto out_tcpv6_protosw;
2011 inet6_unregister_protosw(&tcpv6_protosw);
2013 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2017 void tcpv6_exit(void)
2019 unregister_pernet_subsys(&tcpv6_net_ops);
2020 inet6_unregister_protosw(&tcpv6_protosw);
2021 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);