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 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(&sk->sk_v6_daddr, &usin->sin6_addr)) {
195 tp->rx_opt.ts_recent = 0;
196 tp->rx_opt.ts_recent_stamp = 0;
200 sk->sk_v6_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,
239 &sk->sk_v6_rcv_saddr);
245 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
246 saddr = &sk->sk_v6_rcv_saddr;
248 fl6.flowi6_proto = IPPROTO_TCP;
249 fl6.daddr = sk->sk_v6_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;
256 final_p = fl6_update_dst(&fl6, np->opt, &final);
258 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
260 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
268 sk->sk_v6_rcv_saddr = *saddr;
271 /* set the source address */
273 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
275 sk->sk_gso_type = SKB_GSO_TCPV6;
276 __ip6_dst_store(sk, dst, NULL, NULL);
278 rt = (struct rt6_info *) dst;
279 if (tcp_death_row.sysctl_tw_recycle &&
280 !tp->rx_opt.ts_recent_stamp &&
281 ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
282 tcp_fetch_timewait_stamp(sk, dst);
284 icsk->icsk_ext_hdr_len = 0;
286 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
289 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
291 inet->inet_dport = usin->sin6_port;
293 tcp_set_state(sk, TCP_SYN_SENT);
294 err = inet6_hash_connect(&tcp_death_row, sk);
298 if (!tp->write_seq && likely(!tp->repair))
299 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
300 sk->sk_v6_daddr.s6_addr32,
304 err = tcp_connect(sk);
311 tcp_set_state(sk, TCP_CLOSE);
314 inet->inet_dport = 0;
315 sk->sk_route_caps = 0;
319 static void tcp_v6_mtu_reduced(struct sock *sk)
321 struct dst_entry *dst;
323 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
326 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
330 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
331 tcp_sync_mss(sk, dst_mtu(dst));
332 tcp_simple_retransmit(sk);
336 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
337 u8 type, u8 code, int offset, __be32 info)
339 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
340 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
341 struct ipv6_pinfo *np;
346 struct net *net = dev_net(skb->dev);
348 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
349 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
352 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
357 if (sk->sk_state == TCP_TIME_WAIT) {
358 inet_twsk_put(inet_twsk(sk));
363 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
364 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
366 if (sk->sk_state == TCP_CLOSE)
369 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
370 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
375 seq = ntohl(th->seq);
376 if (sk->sk_state != TCP_LISTEN &&
377 !between(seq, tp->snd_una, tp->snd_nxt)) {
378 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
384 if (type == NDISC_REDIRECT) {
385 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
388 dst->ops->redirect(dst, sk, skb);
392 if (type == ICMPV6_PKT_TOOBIG) {
393 /* We are not interested in TCP_LISTEN and open_requests
394 * (SYN-ACKs send out by Linux are always <576bytes so
395 * they should go through unfragmented).
397 if (sk->sk_state == TCP_LISTEN)
400 tp->mtu_info = ntohl(info);
401 if (!sock_owned_by_user(sk))
402 tcp_v6_mtu_reduced(sk);
403 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
409 icmpv6_err_convert(type, code, &err);
411 /* Might be for an request_sock */
412 switch (sk->sk_state) {
413 struct request_sock *req, **prev;
415 if (sock_owned_by_user(sk))
418 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
419 &hdr->saddr, inet6_iif(skb));
423 /* ICMPs are not backlogged, hence we cannot get
424 * an established socket here.
426 WARN_ON(req->sk != NULL);
428 if (seq != tcp_rsk(req)->snt_isn) {
429 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
433 inet_csk_reqsk_queue_drop(sk, req, prev);
434 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
438 case TCP_SYN_RECV: /* Cannot happen.
439 It can, it SYNs are crossed. --ANK */
440 if (!sock_owned_by_user(sk)) {
442 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
446 sk->sk_err_soft = err;
450 if (!sock_owned_by_user(sk) && np->recverr) {
452 sk->sk_error_report(sk);
454 sk->sk_err_soft = err;
462 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
464 struct request_sock *req,
467 struct inet_request_sock *ireq = inet_rsk(req);
468 struct ipv6_pinfo *np = inet6_sk(sk);
469 struct sk_buff * skb;
472 /* First, grab a route. */
473 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
476 skb = tcp_make_synack(sk, dst, req, NULL);
479 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
480 &ireq->ir_v6_rmt_addr);
482 fl6->daddr = ireq->ir_v6_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(inet_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, &addr_sk->sk_v6_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, &inet_rsk(req)->ir_v6_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 = &sk->sk_v6_daddr;
626 saddr = &inet_rsk(req)->ir_v6_loc_addr;
627 daddr = &inet_rsk(req)->ir_v6_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 inet_request_sock *ireq;
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 ireq = inet_rsk(req);
998 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
999 ireq->ir_v6_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 ireq->ir_iif = sk->sk_bound_dev_if;
1005 /* So that link locals have meaning */
1006 if (!sk->sk_bound_dev_if &&
1007 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
1008 ireq->ir_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 ireq->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 &ireq->ir_v6_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 inet_request_sock *ireq;
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, &newsk->sk_v6_daddr);
1121 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1123 newsk->sk_v6_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 ireq = inet_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 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1189 newnp->saddr = ireq->ir_v6_loc_addr;
1190 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1191 newsk->sk_bound_dev_if = ireq->ir_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 (ireq->pktopts != NULL) {
1207 newnp->pktoptions = skb_clone(ireq->pktopts,
1208 sk_gfp_atomic(sk, GFP_ATOMIC));
1209 consume_skb(ireq->pktopts);
1210 ireq->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, &newsk->sk_v6_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 *)&newsk->sk_v6_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 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1365 goto ipv6_pktoptions;
1369 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1372 if (sk->sk_state == TCP_LISTEN) {
1373 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1378 * Queue it on the new socket if the new socket is active,
1379 * otherwise we just shortcircuit this and continue with
1383 sock_rps_save_rxhash(nsk, skb);
1384 if (tcp_child_process(sk, nsk, skb))
1387 __kfree_skb(opt_skb);
1391 sock_rps_save_rxhash(sk, skb);
1393 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1396 goto ipv6_pktoptions;
1400 tcp_v6_send_reset(sk, skb);
1403 __kfree_skb(opt_skb);
1407 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1408 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1413 /* Do you ask, what is it?
1415 1. skb was enqueued by tcp.
1416 2. skb is added to tail of read queue, rather than out of order.
1417 3. socket is not in passive state.
1418 4. Finally, it really contains options, which user wants to receive.
1421 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1422 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1423 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1424 np->mcast_oif = inet6_iif(opt_skb);
1425 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1426 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1427 if (np->rxopt.bits.rxtclass)
1428 np->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(opt_skb));
1429 if (ipv6_opt_accepted(sk, opt_skb)) {
1430 skb_set_owner_r(opt_skb, sk);
1431 opt_skb = xchg(&np->pktoptions, opt_skb);
1433 __kfree_skb(opt_skb);
1434 opt_skb = xchg(&np->pktoptions, NULL);
1442 static int tcp_v6_rcv(struct sk_buff *skb)
1444 const struct tcphdr *th;
1445 const struct ipv6hdr *hdr;
1448 struct net *net = dev_net(skb->dev);
1450 if (skb->pkt_type != PACKET_HOST)
1454 * Count it even if it's bad.
1456 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1458 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1463 if (th->doff < sizeof(struct tcphdr)/4)
1465 if (!pskb_may_pull(skb, th->doff*4))
1468 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1472 hdr = ipv6_hdr(skb);
1473 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1474 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1475 skb->len - th->doff*4);
1476 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1477 TCP_SKB_CB(skb)->when = 0;
1478 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1479 TCP_SKB_CB(skb)->sacked = 0;
1481 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1486 if (sk->sk_state == TCP_TIME_WAIT)
1489 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1490 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1491 goto discard_and_relse;
1494 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1495 goto discard_and_relse;
1497 if (sk_filter(sk, skb))
1498 goto discard_and_relse;
1500 sk_mark_napi_id(sk, skb);
1503 bh_lock_sock_nested(sk);
1505 if (!sock_owned_by_user(sk)) {
1506 #ifdef CONFIG_NET_DMA
1507 struct tcp_sock *tp = tcp_sk(sk);
1508 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1509 tp->ucopy.dma_chan = net_dma_find_channel();
1510 if (tp->ucopy.dma_chan)
1511 ret = tcp_v6_do_rcv(sk, skb);
1515 if (!tcp_prequeue(sk, skb))
1516 ret = tcp_v6_do_rcv(sk, skb);
1518 } else if (unlikely(sk_add_backlog(sk, skb,
1519 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1521 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1522 goto discard_and_relse;
1527 return ret ? -1 : 0;
1530 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1533 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1535 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1537 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1539 tcp_v6_send_reset(NULL, skb);
1551 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1552 inet_twsk_put(inet_twsk(sk));
1556 if (skb->len < (th->doff<<2)) {
1557 inet_twsk_put(inet_twsk(sk));
1560 if (tcp_checksum_complete(skb)) {
1561 inet_twsk_put(inet_twsk(sk));
1565 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1570 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1571 &ipv6_hdr(skb)->saddr, th->source,
1572 &ipv6_hdr(skb)->daddr,
1573 ntohs(th->dest), inet6_iif(skb));
1575 struct inet_timewait_sock *tw = inet_twsk(sk);
1576 inet_twsk_deschedule(tw, &tcp_death_row);
1581 /* Fall through to ACK */
1584 tcp_v6_timewait_ack(sk, skb);
1588 case TCP_TW_SUCCESS:;
1593 static void tcp_v6_early_demux(struct sk_buff *skb)
1595 const struct ipv6hdr *hdr;
1596 const struct tcphdr *th;
1599 if (skb->pkt_type != PACKET_HOST)
1602 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1605 hdr = ipv6_hdr(skb);
1608 if (th->doff < sizeof(struct tcphdr) / 4)
1611 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1612 &hdr->saddr, th->source,
1613 &hdr->daddr, ntohs(th->dest),
1617 skb->destructor = sock_edemux;
1618 if (sk->sk_state != TCP_TIME_WAIT) {
1619 struct dst_entry *dst = sk->sk_rx_dst;
1622 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1624 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1625 skb_dst_set_noref(skb, dst);
1630 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1631 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1632 .twsk_unique = tcp_twsk_unique,
1633 .twsk_destructor= tcp_twsk_destructor,
1636 static const struct inet_connection_sock_af_ops ipv6_specific = {
1637 .queue_xmit = inet6_csk_xmit,
1638 .send_check = tcp_v6_send_check,
1639 .rebuild_header = inet6_sk_rebuild_header,
1640 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1641 .conn_request = tcp_v6_conn_request,
1642 .syn_recv_sock = tcp_v6_syn_recv_sock,
1643 .net_header_len = sizeof(struct ipv6hdr),
1644 .net_frag_header_len = sizeof(struct frag_hdr),
1645 .setsockopt = ipv6_setsockopt,
1646 .getsockopt = ipv6_getsockopt,
1647 .addr2sockaddr = inet6_csk_addr2sockaddr,
1648 .sockaddr_len = sizeof(struct sockaddr_in6),
1649 .bind_conflict = inet6_csk_bind_conflict,
1650 #ifdef CONFIG_COMPAT
1651 .compat_setsockopt = compat_ipv6_setsockopt,
1652 .compat_getsockopt = compat_ipv6_getsockopt,
1656 #ifdef CONFIG_TCP_MD5SIG
1657 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1658 .md5_lookup = tcp_v6_md5_lookup,
1659 .calc_md5_hash = tcp_v6_md5_hash_skb,
1660 .md5_parse = tcp_v6_parse_md5_keys,
1665 * TCP over IPv4 via INET6 API
1668 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1669 .queue_xmit = ip_queue_xmit,
1670 .send_check = tcp_v4_send_check,
1671 .rebuild_header = inet_sk_rebuild_header,
1672 .sk_rx_dst_set = inet_sk_rx_dst_set,
1673 .conn_request = tcp_v6_conn_request,
1674 .syn_recv_sock = tcp_v6_syn_recv_sock,
1675 .net_header_len = sizeof(struct iphdr),
1676 .setsockopt = ipv6_setsockopt,
1677 .getsockopt = ipv6_getsockopt,
1678 .addr2sockaddr = inet6_csk_addr2sockaddr,
1679 .sockaddr_len = sizeof(struct sockaddr_in6),
1680 .bind_conflict = inet6_csk_bind_conflict,
1681 #ifdef CONFIG_COMPAT
1682 .compat_setsockopt = compat_ipv6_setsockopt,
1683 .compat_getsockopt = compat_ipv6_getsockopt,
1687 #ifdef CONFIG_TCP_MD5SIG
1688 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1689 .md5_lookup = tcp_v4_md5_lookup,
1690 .calc_md5_hash = tcp_v4_md5_hash_skb,
1691 .md5_parse = tcp_v6_parse_md5_keys,
1695 /* NOTE: A lot of things set to zero explicitly by call to
1696 * sk_alloc() so need not be done here.
1698 static int tcp_v6_init_sock(struct sock *sk)
1700 struct inet_connection_sock *icsk = inet_csk(sk);
1704 icsk->icsk_af_ops = &ipv6_specific;
1706 #ifdef CONFIG_TCP_MD5SIG
1707 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1713 static void tcp_v6_destroy_sock(struct sock *sk)
1715 tcp_v4_destroy_sock(sk);
1716 inet6_destroy_sock(sk);
1719 #ifdef CONFIG_PROC_FS
1720 /* Proc filesystem TCPv6 sock list dumping. */
1721 static void get_openreq6(struct seq_file *seq,
1722 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1724 int ttd = req->expires - jiffies;
1725 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1726 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1732 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1733 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1735 src->s6_addr32[0], src->s6_addr32[1],
1736 src->s6_addr32[2], src->s6_addr32[3],
1737 inet_rsk(req)->ir_num,
1738 dest->s6_addr32[0], dest->s6_addr32[1],
1739 dest->s6_addr32[2], dest->s6_addr32[3],
1740 ntohs(inet_rsk(req)->ir_rmt_port),
1742 0,0, /* could print option size, but that is af dependent. */
1743 1, /* timers active (only the expire timer) */
1744 jiffies_to_clock_t(ttd),
1746 from_kuid_munged(seq_user_ns(seq), uid),
1747 0, /* non standard timer */
1748 0, /* open_requests have no inode */
1752 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1754 const struct in6_addr *dest, *src;
1757 unsigned long timer_expires;
1758 const struct inet_sock *inet = inet_sk(sp);
1759 const struct tcp_sock *tp = tcp_sk(sp);
1760 const struct inet_connection_sock *icsk = inet_csk(sp);
1762 dest = &sp->sk_v6_daddr;
1763 src = &sp->sk_v6_rcv_saddr;
1764 destp = ntohs(inet->inet_dport);
1765 srcp = ntohs(inet->inet_sport);
1767 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1769 timer_expires = icsk->icsk_timeout;
1770 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1772 timer_expires = icsk->icsk_timeout;
1773 } else if (timer_pending(&sp->sk_timer)) {
1775 timer_expires = sp->sk_timer.expires;
1778 timer_expires = jiffies;
1782 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1783 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1785 src->s6_addr32[0], src->s6_addr32[1],
1786 src->s6_addr32[2], src->s6_addr32[3], srcp,
1787 dest->s6_addr32[0], dest->s6_addr32[1],
1788 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1790 tp->write_seq-tp->snd_una,
1791 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1793 jiffies_delta_to_clock_t(timer_expires - jiffies),
1794 icsk->icsk_retransmits,
1795 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1796 icsk->icsk_probes_out,
1798 atomic_read(&sp->sk_refcnt), sp,
1799 jiffies_to_clock_t(icsk->icsk_rto),
1800 jiffies_to_clock_t(icsk->icsk_ack.ato),
1801 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1803 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1807 static void get_timewait6_sock(struct seq_file *seq,
1808 struct inet_timewait_sock *tw, int i)
1810 const struct in6_addr *dest, *src;
1812 s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1814 dest = &tw->tw_v6_daddr;
1815 src = &tw->tw_v6_rcv_saddr;
1816 destp = ntohs(tw->tw_dport);
1817 srcp = ntohs(tw->tw_sport);
1820 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1821 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1823 src->s6_addr32[0], src->s6_addr32[1],
1824 src->s6_addr32[2], src->s6_addr32[3], srcp,
1825 dest->s6_addr32[0], dest->s6_addr32[1],
1826 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1827 tw->tw_substate, 0, 0,
1828 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1829 atomic_read(&tw->tw_refcnt), tw);
1832 static int tcp6_seq_show(struct seq_file *seq, void *v)
1834 struct tcp_iter_state *st;
1835 struct sock *sk = v;
1837 if (v == SEQ_START_TOKEN) {
1842 "st tx_queue rx_queue tr tm->when retrnsmt"
1843 " uid timeout inode\n");
1848 switch (st->state) {
1849 case TCP_SEQ_STATE_LISTENING:
1850 case TCP_SEQ_STATE_ESTABLISHED:
1851 if (sk->sk_state == TCP_TIME_WAIT)
1852 get_timewait6_sock(seq, v, st->num);
1854 get_tcp6_sock(seq, v, st->num);
1856 case TCP_SEQ_STATE_OPENREQ:
1857 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1864 static const struct file_operations tcp6_afinfo_seq_fops = {
1865 .owner = THIS_MODULE,
1866 .open = tcp_seq_open,
1868 .llseek = seq_lseek,
1869 .release = seq_release_net
1872 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1875 .seq_fops = &tcp6_afinfo_seq_fops,
1877 .show = tcp6_seq_show,
1881 int __net_init tcp6_proc_init(struct net *net)
1883 return tcp_proc_register(net, &tcp6_seq_afinfo);
1886 void tcp6_proc_exit(struct net *net)
1888 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1892 static void tcp_v6_clear_sk(struct sock *sk, int size)
1894 struct inet_sock *inet = inet_sk(sk);
1896 /* we do not want to clear pinet6 field, because of RCU lookups */
1897 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1899 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1900 memset(&inet->pinet6 + 1, 0, size);
1903 struct proto tcpv6_prot = {
1905 .owner = THIS_MODULE,
1907 .connect = tcp_v6_connect,
1908 .disconnect = tcp_disconnect,
1909 .accept = inet_csk_accept,
1911 .init = tcp_v6_init_sock,
1912 .destroy = tcp_v6_destroy_sock,
1913 .shutdown = tcp_shutdown,
1914 .setsockopt = tcp_setsockopt,
1915 .getsockopt = tcp_getsockopt,
1916 .recvmsg = tcp_recvmsg,
1917 .sendmsg = tcp_sendmsg,
1918 .sendpage = tcp_sendpage,
1919 .backlog_rcv = tcp_v6_do_rcv,
1920 .release_cb = tcp_release_cb,
1921 .mtu_reduced = tcp_v6_mtu_reduced,
1922 .hash = tcp_v6_hash,
1923 .unhash = inet_unhash,
1924 .get_port = inet_csk_get_port,
1925 .enter_memory_pressure = tcp_enter_memory_pressure,
1926 .stream_memory_free = tcp_stream_memory_free,
1927 .sockets_allocated = &tcp_sockets_allocated,
1928 .memory_allocated = &tcp_memory_allocated,
1929 .memory_pressure = &tcp_memory_pressure,
1930 .orphan_count = &tcp_orphan_count,
1931 .sysctl_mem = sysctl_tcp_mem,
1932 .sysctl_wmem = sysctl_tcp_wmem,
1933 .sysctl_rmem = sysctl_tcp_rmem,
1934 .max_header = MAX_TCP_HEADER,
1935 .obj_size = sizeof(struct tcp6_sock),
1936 .slab_flags = SLAB_DESTROY_BY_RCU,
1937 .twsk_prot = &tcp6_timewait_sock_ops,
1938 .rsk_prot = &tcp6_request_sock_ops,
1939 .h.hashinfo = &tcp_hashinfo,
1940 .no_autobind = true,
1941 #ifdef CONFIG_COMPAT
1942 .compat_setsockopt = compat_tcp_setsockopt,
1943 .compat_getsockopt = compat_tcp_getsockopt,
1945 #ifdef CONFIG_MEMCG_KMEM
1946 .proto_cgroup = tcp_proto_cgroup,
1948 .clear_sk = tcp_v6_clear_sk,
1951 static const struct inet6_protocol tcpv6_protocol = {
1952 .early_demux = tcp_v6_early_demux,
1953 .handler = tcp_v6_rcv,
1954 .err_handler = tcp_v6_err,
1955 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1958 static struct inet_protosw tcpv6_protosw = {
1959 .type = SOCK_STREAM,
1960 .protocol = IPPROTO_TCP,
1961 .prot = &tcpv6_prot,
1962 .ops = &inet6_stream_ops,
1964 .flags = INET_PROTOSW_PERMANENT |
1968 static int __net_init tcpv6_net_init(struct net *net)
1970 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1971 SOCK_RAW, IPPROTO_TCP, net);
1974 static void __net_exit tcpv6_net_exit(struct net *net)
1976 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1979 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1981 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1984 static struct pernet_operations tcpv6_net_ops = {
1985 .init = tcpv6_net_init,
1986 .exit = tcpv6_net_exit,
1987 .exit_batch = tcpv6_net_exit_batch,
1990 int __init tcpv6_init(void)
1994 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1998 /* register inet6 protocol */
1999 ret = inet6_register_protosw(&tcpv6_protosw);
2001 goto out_tcpv6_protocol;
2003 ret = register_pernet_subsys(&tcpv6_net_ops);
2005 goto out_tcpv6_protosw;
2010 inet6_unregister_protosw(&tcpv6_protosw);
2012 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2016 void tcpv6_exit(void)
2018 unregister_pernet_subsys(&tcpv6_net_ops);
2019 inet6_unregister_protosw(&tcpv6_protosw);
2020 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);