tcp_ipv6.c 51.2 KB
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/*
 *	TCP over IPv6
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 *	Linux INET6 implementation
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 *
 *	Authors:
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 *	Pedro Roque		<roque@di.fc.ul.pt>
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 *
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 *	Based on:
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 *	linux/net/ipv4/tcp.c
 *	linux/net/ipv4/tcp_input.c
 *	linux/net/ipv4/tcp_output.c
 *
 *	Fixes:
 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
 *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
 *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
 *					a single port at the same time.
 *	YOSHIFUJI Hideaki @USAGI:	convert /proc/net/tcp6 to seq_file.
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

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#include <linux/bottom_half.h>
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#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/jiffies.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/jhash.h>
#include <linux/ipsec.h>
#include <linux/times.h>
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#include <linux/slab.h>
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#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/random.h>

#include <net/tcp.h>
#include <net/ndisc.h>
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#include <net/inet6_hashtables.h>
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#include <net/inet6_connection_sock.h>
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#include <net/ipv6.h>
#include <net/transp_v6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/ip6_checksum.h>
#include <net/inet_ecn.h>
#include <net/protocol.h>
#include <net/xfrm.h>
#include <net/snmp.h>
#include <net/dsfield.h>
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#include <net/timewait_sock.h>
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#include <net/netdma.h>
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#include <net/inet_common.h>
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#include <net/secure_seq.h>
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#include <net/tcp_memcontrol.h>
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#include <net/busy_poll.h>
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#include <asm/uaccess.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>

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#include <linux/crypto.h>
#include <linux/scatterlist.h>

static void	tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
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static void	tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
				      struct request_sock *req);
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static int	tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);

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static const struct inet_connection_sock_af_ops ipv6_mapped;
static const struct inet_connection_sock_af_ops ipv6_specific;
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#ifdef CONFIG_TCP_MD5SIG
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static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
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#else
static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
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						   const struct in6_addr *addr)
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{
	return NULL;
}
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#endif
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static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	const struct rt6_info *rt = (const struct rt6_info *)dst;

	dst_hold(dst);
	sk->sk_rx_dst = dst;
	inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
	if (rt->rt6i_node)
		inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
}

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static void tcp_v6_hash(struct sock *sk)
{
	if (sk->sk_state != TCP_CLOSE) {
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		if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
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			tcp_prot.hash(sk);
			return;
		}
		local_bh_disable();
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		__inet6_hash(sk, NULL);
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		local_bh_enable();
	}
}

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static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
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{
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	return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
					    ipv6_hdr(skb)->saddr.s6_addr32,
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					    tcp_hdr(skb)->dest,
					    tcp_hdr(skb)->source);
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}

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static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
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			  int addr_len)
{
	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
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	struct inet_sock *inet = inet_sk(sk);
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	struct inet_connection_sock *icsk = inet_csk(sk);
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	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_sock *tp = tcp_sk(sk);
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	struct in6_addr *saddr = NULL, *final_p, final;
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	struct rt6_info *rt;
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	struct flowi6 fl6;
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	struct dst_entry *dst;
	int addr_type;
	int err;

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	if (addr_len < SIN6_LEN_RFC2133)
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		return -EINVAL;

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	if (usin->sin6_family != AF_INET6)
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		return -EAFNOSUPPORT;
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	memset(&fl6, 0, sizeof(fl6));
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	if (np->sndflow) {
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		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
		IP6_ECN_flow_init(fl6.flowlabel);
		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
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			struct ip6_flowlabel *flowlabel;
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			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
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			if (flowlabel == NULL)
				return -EINVAL;
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			usin->sin6_addr = flowlabel->dst;
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			fl6_sock_release(flowlabel);
		}
	}

	/*
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	 *	connect() to INADDR_ANY means loopback (BSD'ism).
	 */

	if(ipv6_addr_any(&usin->sin6_addr))
		usin->sin6_addr.s6_addr[15] = 0x1;
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	addr_type = ipv6_addr_type(&usin->sin6_addr);

	if(addr_type & IPV6_ADDR_MULTICAST)
		return -ENETUNREACH;

	if (addr_type&IPV6_ADDR_LINKLOCAL) {
		if (addr_len >= sizeof(struct sockaddr_in6) &&
		    usin->sin6_scope_id) {
			/* If interface is set while binding, indices
			 * must coincide.
			 */
			if (sk->sk_bound_dev_if &&
			    sk->sk_bound_dev_if != usin->sin6_scope_id)
				return -EINVAL;

			sk->sk_bound_dev_if = usin->sin6_scope_id;
		}

		/* Connect to link-local address requires an interface */
		if (!sk->sk_bound_dev_if)
			return -EINVAL;
	}

	if (tp->rx_opt.ts_recent_stamp &&
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	    !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
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		tp->rx_opt.ts_recent = 0;
		tp->rx_opt.ts_recent_stamp = 0;
		tp->write_seq = 0;
	}

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	sk->sk_v6_daddr = usin->sin6_addr;
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	np->flow_label = fl6.flowlabel;
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	/*
	 *	TCP over IPv4
	 */

	if (addr_type == IPV6_ADDR_MAPPED) {
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		u32 exthdrlen = icsk->icsk_ext_hdr_len;
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		struct sockaddr_in sin;

		SOCK_DEBUG(sk, "connect: ipv4 mapped\n");

		if (__ipv6_only_sock(sk))
			return -ENETUNREACH;

		sin.sin_family = AF_INET;
		sin.sin_port = usin->sin6_port;
		sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];

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		icsk->icsk_af_ops = &ipv6_mapped;
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		sk->sk_backlog_rcv = tcp_v4_do_rcv;
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#ifdef CONFIG_TCP_MD5SIG
		tp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif
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		err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));

		if (err) {
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			icsk->icsk_ext_hdr_len = exthdrlen;
			icsk->icsk_af_ops = &ipv6_specific;
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			sk->sk_backlog_rcv = tcp_v6_do_rcv;
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#ifdef CONFIG_TCP_MD5SIG
			tp->af_specific = &tcp_sock_ipv6_specific;
#endif
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			goto failure;
		} else {
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			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
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					       &sk->sk_v6_rcv_saddr);
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		}

		return err;
	}

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	if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
		saddr = &sk->sk_v6_rcv_saddr;
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	fl6.flowi6_proto = IPPROTO_TCP;
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	fl6.daddr = sk->sk_v6_daddr;
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	fl6.saddr = saddr ? *saddr : np->saddr;
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	fl6.flowi6_oif = sk->sk_bound_dev_if;
	fl6.flowi6_mark = sk->sk_mark;
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	fl6.fl6_dport = usin->sin6_port;
	fl6.fl6_sport = inet->inet_sport;
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	final_p = fl6_update_dst(&fl6, np->opt, &final);
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	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
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	dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
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	if (IS_ERR(dst)) {
		err = PTR_ERR(dst);
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		goto failure;
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	}
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	if (saddr == NULL) {
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		saddr = &fl6.saddr;
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		sk->sk_v6_rcv_saddr = *saddr;
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	}

	/* set the source address */
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	np->saddr = *saddr;
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	inet->inet_rcv_saddr = LOOPBACK4_IPV6;
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	sk->sk_gso_type = SKB_GSO_TCPV6;
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	__ip6_dst_store(sk, dst, NULL, NULL);
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	rt = (struct rt6_info *) dst;
	if (tcp_death_row.sysctl_tw_recycle &&
	    !tp->rx_opt.ts_recent_stamp &&
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	    ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
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		tcp_fetch_timewait_stamp(sk, dst);
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	icsk->icsk_ext_hdr_len = 0;
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	if (np->opt)
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		icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
					  np->opt->opt_nflen);
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	tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);

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	inet->inet_dport = usin->sin6_port;
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	tcp_set_state(sk, TCP_SYN_SENT);
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	err = inet6_hash_connect(&tcp_death_row, sk);
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	if (err)
		goto late_failure;

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	if (!tp->write_seq && likely(!tp->repair))
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		tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
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							     sk->sk_v6_daddr.s6_addr32,
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							     inet->inet_sport,
							     inet->inet_dport);
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	err = tcp_connect(sk);
	if (err)
		goto late_failure;

	return 0;

late_failure:
	tcp_set_state(sk, TCP_CLOSE);
	__sk_dst_reset(sk);
failure:
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	inet->inet_dport = 0;
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	sk->sk_route_caps = 0;
	return err;
}

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static void tcp_v6_mtu_reduced(struct sock *sk)
{
	struct dst_entry *dst;

	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
		return;

	dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
	if (!dst)
		return;

	if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
		tcp_sync_mss(sk, dst_mtu(dst));
		tcp_simple_retransmit(sk);
	}
}

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static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
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		u8 type, u8 code, int offset, __be32 info)
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{
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	const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
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	const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
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	struct ipv6_pinfo *np;
	struct sock *sk;
	int err;
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	struct tcp_sock *tp;
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	__u32 seq;
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	struct net *net = dev_net(skb->dev);
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	sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
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			th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
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	if (sk == NULL) {
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		ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
				   ICMP6_MIB_INERRORS);
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		return;
	}

	if (sk->sk_state == TCP_TIME_WAIT) {
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		inet_twsk_put(inet_twsk(sk));
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		return;
	}

	bh_lock_sock(sk);
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	if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
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		NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
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	if (sk->sk_state == TCP_CLOSE)
		goto out;

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	if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
		NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
		goto out;
	}

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	tp = tcp_sk(sk);
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	seq = ntohl(th->seq);
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	if (sk->sk_state != TCP_LISTEN &&
	    !between(seq, tp->snd_una, tp->snd_nxt)) {
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		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
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		goto out;
	}

	np = inet6_sk(sk);

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	if (type == NDISC_REDIRECT) {
		struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);

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		if (dst)
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			dst->ops->redirect(dst, sk, skb);
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		goto out;
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	}

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	if (type == ICMPV6_PKT_TOOBIG) {
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		/* We are not interested in TCP_LISTEN and open_requests
		 * (SYN-ACKs send out by Linux are always <576bytes so
		 * they should go through unfragmented).
		 */
		if (sk->sk_state == TCP_LISTEN)
			goto out;

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		tp->mtu_info = ntohl(info);
		if (!sock_owned_by_user(sk))
			tcp_v6_mtu_reduced(sk);
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		else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
					   &tp->tsq_flags))
			sock_hold(sk);
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		goto out;
	}

	icmpv6_err_convert(type, code, &err);

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	/* Might be for an request_sock */
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	switch (sk->sk_state) {
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		struct request_sock *req, **prev;
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	case TCP_LISTEN:
		if (sock_owned_by_user(sk))
			goto out;

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		req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
					   &hdr->saddr, inet6_iif(skb));
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		if (!req)
			goto out;

		/* ICMPs are not backlogged, hence we cannot get
		 * an established socket here.
		 */
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		WARN_ON(req->sk != NULL);
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		if (seq != tcp_rsk(req)->snt_isn) {
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			NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
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			goto out;
		}

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		inet_csk_reqsk_queue_drop(sk, req, prev);
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		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
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		goto out;

	case TCP_SYN_SENT:
	case TCP_SYN_RECV:  /* Cannot happen.
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			       It can, it SYNs are crossed. --ANK */
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		if (!sock_owned_by_user(sk)) {
			sk->sk_err = err;
			sk->sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */

			tcp_done(sk);
		} else
			sk->sk_err_soft = err;
		goto out;
	}

	if (!sock_owned_by_user(sk) && np->recverr) {
		sk->sk_err = err;
		sk->sk_error_report(sk);
	} else
		sk->sk_err_soft = err;

out:
	bh_unlock_sock(sk);
	sock_put(sk);
}


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static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
			      struct flowi6 *fl6,
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			      struct request_sock *req,
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			      u16 queue_mapping)
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{
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	struct inet_request_sock *ireq = inet_rsk(req);
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	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff * skb;
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	int err = -ENOMEM;
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	/* First, grab a route. */
	if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
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		goto done;
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	skb = tcp_make_synack(sk, dst, req, NULL);
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	if (skb) {
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		__tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
				    &ireq->ir_v6_rmt_addr);
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		fl6->daddr = ireq->ir_v6_rmt_addr;
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		skb_set_queue_mapping(skb, queue_mapping);
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		err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
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		err = net_xmit_eval(err);
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	}

done:
	return err;
}

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static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
494
{
495
	struct flowi6 fl6;
496
	int res;
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	res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
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	if (!res)
		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
	return res;
502 503
}

504
static void tcp_v6_reqsk_destructor(struct request_sock *req)
L
Linus Torvalds 已提交
505
{
506
	kfree_skb(inet_rsk(req)->pktopts);
L
Linus Torvalds 已提交
507 508
}

509 510
#ifdef CONFIG_TCP_MD5SIG
static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
511
						   const struct in6_addr *addr)
512
{
E
Eric Dumazet 已提交
513
	return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
514 515 516 517 518
}

static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
						struct sock *addr_sk)
{
519
	return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
520 521 522 523 524
}

static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
						      struct request_sock *req)
{
525
	return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543
}

static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
				  int optlen)
{
	struct tcp_md5sig cmd;
	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;

	if (optlen < sizeof(cmd))
		return -EINVAL;

	if (copy_from_user(&cmd, optval, sizeof(cmd)))
		return -EFAULT;

	if (sin6->sin6_family != AF_INET6)
		return -EINVAL;

	if (!cmd.tcpm_keylen) {
B
Brian Haley 已提交
544
		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
E
Eric Dumazet 已提交
545 546 547 548
			return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
					      AF_INET);
		return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
				      AF_INET6);
549 550 551 552 553
	}

	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
		return -EINVAL;

E
Eric Dumazet 已提交
554 555 556
	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
		return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
				      AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
557

E
Eric Dumazet 已提交
558 559
	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
			      AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
560 561
}

562
static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
563 564
					const struct in6_addr *daddr,
					const struct in6_addr *saddr, int nbytes)
565 566
{
	struct tcp6_pseudohdr *bp;
567
	struct scatterlist sg;
568

569 570
	bp = &hp->md5_blk.ip6;
	/* 1. TCP pseudo-header (RFC2460) */
A
Alexey Dobriyan 已提交
571 572
	bp->saddr = *saddr;
	bp->daddr = *daddr;
573
	bp->protocol = cpu_to_be32(IPPROTO_TCP);
A
Adam Langley 已提交
574
	bp->len = cpu_to_be32(nbytes);
575

576 577 578
	sg_init_one(&sg, bp, sizeof(*bp));
	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
}
579

580
static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
581
			       const struct in6_addr *daddr, struct in6_addr *saddr,
E
Eric Dumazet 已提交
582
			       const struct tcphdr *th)
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600
{
	struct tcp_md5sig_pool *hp;
	struct hash_desc *desc;

	hp = tcp_get_md5sig_pool();
	if (!hp)
		goto clear_hash_noput;
	desc = &hp->md5_desc;

	if (crypto_hash_init(desc))
		goto clear_hash;
	if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
		goto clear_hash;
	if (tcp_md5_hash_header(hp, th))
		goto clear_hash;
	if (tcp_md5_hash_key(hp, key))
		goto clear_hash;
	if (crypto_hash_final(desc, md5_hash))
601 602 603 604
		goto clear_hash;

	tcp_put_md5sig_pool();
	return 0;
605

606 607 608 609
clear_hash:
	tcp_put_md5sig_pool();
clear_hash_noput:
	memset(md5_hash, 0, 16);
610
	return 1;
611 612
}

613
static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
E
Eric Dumazet 已提交
614 615 616
			       const struct sock *sk,
			       const struct request_sock *req,
			       const struct sk_buff *skb)
617
{
618
	const struct in6_addr *saddr, *daddr;
619 620
	struct tcp_md5sig_pool *hp;
	struct hash_desc *desc;
E
Eric Dumazet 已提交
621
	const struct tcphdr *th = tcp_hdr(skb);
622 623 624

	if (sk) {
		saddr = &inet6_sk(sk)->saddr;
625
		daddr = &sk->sk_v6_daddr;
626
	} else if (req) {
627 628
		saddr = &inet_rsk(req)->ir_v6_loc_addr;
		daddr = &inet_rsk(req)->ir_v6_rmt_addr;
629
	} else {
630
		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
631 632
		saddr = &ip6h->saddr;
		daddr = &ip6h->daddr;
633
	}
634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661

	hp = tcp_get_md5sig_pool();
	if (!hp)
		goto clear_hash_noput;
	desc = &hp->md5_desc;

	if (crypto_hash_init(desc))
		goto clear_hash;

	if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
		goto clear_hash;
	if (tcp_md5_hash_header(hp, th))
		goto clear_hash;
	if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
		goto clear_hash;
	if (tcp_md5_hash_key(hp, key))
		goto clear_hash;
	if (crypto_hash_final(desc, md5_hash))
		goto clear_hash;

	tcp_put_md5sig_pool();
	return 0;

clear_hash:
	tcp_put_md5sig_pool();
clear_hash_noput:
	memset(md5_hash, 0, 16);
	return 1;
662 663
}

E
Eric Dumazet 已提交
664
static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
665
{
666
	const __u8 *hash_location = NULL;
667
	struct tcp_md5sig_key *hash_expected;
668
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
E
Eric Dumazet 已提交
669
	const struct tcphdr *th = tcp_hdr(skb);
670 671 672 673
	int genhash;
	u8 newhash[16];

	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
674
	hash_location = tcp_parse_md5sig_option(th);
675

676 677 678 679 680 681
	/* We've parsed the options - do we have a hash? */
	if (!hash_expected && !hash_location)
		return 0;

	if (hash_expected && !hash_location) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
682 683 684
		return 1;
	}

685 686
	if (!hash_expected && hash_location) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
687 688 689 690
		return 1;
	}

	/* check the signature */
691 692 693 694
	genhash = tcp_v6_md5_hash_skb(newhash,
				      hash_expected,
				      NULL, NULL, skb);

695
	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
696 697 698 699
		net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
				     genhash ? "failed" : "mismatch",
				     &ip6h->saddr, ntohs(th->source),
				     &ip6h->daddr, ntohs(th->dest));
700 701 702 703 704 705
		return 1;
	}
	return 0;
}
#endif

706
struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
L
Linus Torvalds 已提交
707
	.family		=	AF_INET6,
708
	.obj_size	=	sizeof(struct tcp6_request_sock),
709
	.rtx_syn_ack	=	tcp_v6_rtx_synack,
710 711
	.send_ack	=	tcp_v6_reqsk_send_ack,
	.destructor	=	tcp_v6_reqsk_destructor,
712 713
	.send_reset	=	tcp_v6_send_reset,
	.syn_ack_timeout = 	tcp_syn_ack_timeout,
L
Linus Torvalds 已提交
714 715
};

716
#ifdef CONFIG_TCP_MD5SIG
717
static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
718
	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
719
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
720
};
721
#endif
722

723
static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
724 725
				 u32 tsval, u32 tsecr,
				 struct tcp_md5sig_key *key, int rst, u8 tclass)
L
Linus Torvalds 已提交
726
{
727 728
	const struct tcphdr *th = tcp_hdr(skb);
	struct tcphdr *t1;
L
Linus Torvalds 已提交
729
	struct sk_buff *buff;
730
	struct flowi6 fl6;
E
Eric Dumazet 已提交
731
	struct net *net = dev_net(skb_dst(skb)->dev);
732
	struct sock *ctl_sk = net->ipv6.tcp_sk;
733
	unsigned int tot_len = sizeof(struct tcphdr);
E
Eric Dumazet 已提交
734
	struct dst_entry *dst;
735
	__be32 *topt;
L
Linus Torvalds 已提交
736

737
	if (tsecr)
738
		tot_len += TCPOLEN_TSTAMP_ALIGNED;
739 740 741 742 743 744
#ifdef CONFIG_TCP_MD5SIG
	if (key)
		tot_len += TCPOLEN_MD5SIG_ALIGNED;
#endif

	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
L
Linus Torvalds 已提交
745
			 GFP_ATOMIC);
746 747
	if (buff == NULL)
		return;
L
Linus Torvalds 已提交
748

749
	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
L
Linus Torvalds 已提交
750

751
	t1 = (struct tcphdr *) skb_push(buff, tot_len);
752
	skb_reset_transport_header(buff);
L
Linus Torvalds 已提交
753 754 755 756 757

	/* Swap the send and the receive. */
	memset(t1, 0, sizeof(*t1));
	t1->dest = th->source;
	t1->source = th->dest;
758
	t1->doff = tot_len / 4;
759 760 761 762 763
	t1->seq = htonl(seq);
	t1->ack_seq = htonl(ack);
	t1->ack = !rst || !th->ack;
	t1->rst = rst;
	t1->window = htons(win);
L
Linus Torvalds 已提交
764

765 766
	topt = (__be32 *)(t1 + 1);

767
	if (tsecr) {
768 769
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
770 771
		*topt++ = htonl(tsval);
		*topt++ = htonl(tsecr);
772 773
	}

774 775
#ifdef CONFIG_TCP_MD5SIG
	if (key) {
776 777 778
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
779 780
				    &ipv6_hdr(skb)->saddr,
				    &ipv6_hdr(skb)->daddr, t1);
781 782 783
	}
#endif

784
	memset(&fl6, 0, sizeof(fl6));
A
Alexey Dobriyan 已提交
785 786
	fl6.daddr = ipv6_hdr(skb)->saddr;
	fl6.saddr = ipv6_hdr(skb)->daddr;
L
Linus Torvalds 已提交
787

788 789 790
	buff->ip_summed = CHECKSUM_PARTIAL;
	buff->csum = 0;

791
	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
L
Linus Torvalds 已提交
792

793
	fl6.flowi6_proto = IPPROTO_TCP;
A
Alexey Kuznetsov 已提交
794 795
	if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
		fl6.flowi6_oif = inet6_iif(skb);
796 797
	fl6.fl6_dport = t1->dest;
	fl6.fl6_sport = t1->source;
798
	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
L
Linus Torvalds 已提交
799

800 801 802 803
	/* Pass a socket to ip6_dst_lookup either it is for RST
	 * Underlying function will use this to retrieve the network
	 * namespace
	 */
804
	dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
805 806
	if (!IS_ERR(dst)) {
		skb_dst_set(buff, dst);
807
		ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
808 809 810 811
		TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
		if (rst)
			TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
		return;
L
Linus Torvalds 已提交
812 813 814 815 816
	}

	kfree_skb(buff);
}

817
static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
818
{
819
	const struct tcphdr *th = tcp_hdr(skb);
820
	u32 seq = 0, ack_seq = 0;
821
	struct tcp_md5sig_key *key = NULL;
822 823 824 825 826 827 828
#ifdef CONFIG_TCP_MD5SIG
	const __u8 *hash_location = NULL;
	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
	unsigned char newhash[16];
	int genhash;
	struct sock *sk1 = NULL;
#endif
L
Linus Torvalds 已提交
829

830
	if (th->rst)
L
Linus Torvalds 已提交
831 832
		return;

833 834
	if (!ipv6_unicast_destination(skb))
		return;
L
Linus Torvalds 已提交
835

836
#ifdef CONFIG_TCP_MD5SIG
837 838 839 840 841 842 843 844 845 846
	hash_location = tcp_parse_md5sig_option(th);
	if (!sk && hash_location) {
		/*
		 * active side is lost. Try to find listening socket through
		 * source port, and then find md5 key through listening socket.
		 * we are not loose security here:
		 * Incoming packet is checked with md5 hash with finding key,
		 * no RST generated if md5 hash doesn't match.
		 */
		sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
847 848
					   &tcp_hashinfo, &ipv6h->saddr,
					   th->source, &ipv6h->daddr,
849 850 851 852 853 854 855 856 857 858 859 860 861 862 863
					   ntohs(th->source), inet6_iif(skb));
		if (!sk1)
			return;

		rcu_read_lock();
		key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
		if (!key)
			goto release_sk1;

		genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
		if (genhash || memcmp(hash_location, newhash, 16) != 0)
			goto release_sk1;
	} else {
		key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
	}
864 865
#endif

866 867 868 869 870
	if (th->ack)
		seq = ntohl(th->ack_seq);
	else
		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
			  (th->doff << 2);
L
Linus Torvalds 已提交
871

872
	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, key, 1, 0);
873 874 875 876 877 878 879 880

#ifdef CONFIG_TCP_MD5SIG
release_sk1:
	if (sk1) {
		rcu_read_unlock();
		sock_put(sk1);
	}
#endif
881
}
L
Linus Torvalds 已提交
882

883 884
static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
			    u32 win, u32 tsval, u32 tsecr,
885
			    struct tcp_md5sig_key *key, u8 tclass)
886
{
887
	tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, key, 0, tclass);
L
Linus Torvalds 已提交
888 889 890 891
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
892
	struct inet_timewait_sock *tw = inet_twsk(sk);
893
	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
L
Linus Torvalds 已提交
894

895
	tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
896
			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
897
			tcp_time_stamp + tcptw->tw_ts_offset,
898 899
			tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
			tw->tw_tclass);
L
Linus Torvalds 已提交
900

901
	inet_twsk_put(tw);
L
Linus Torvalds 已提交
902 903
}

904 905
static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
				  struct request_sock *req)
L
Linus Torvalds 已提交
906
{
907 908
	tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
			req->rcv_wnd, tcp_time_stamp, req->ts_recent,
909
			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
L
Linus Torvalds 已提交
910 911 912 913 914
}


static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
{
915
	struct request_sock *req, **prev;
916
	const struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
917 918 919
	struct sock *nsk;

	/* Find possible connection requests. */
920
	req = inet6_csk_search_req(sk, &prev, th->source,
921 922
				   &ipv6_hdr(skb)->saddr,
				   &ipv6_hdr(skb)->daddr, inet6_iif(skb));
L
Linus Torvalds 已提交
923
	if (req)
924
		return tcp_check_req(sk, skb, req, prev, false);
L
Linus Torvalds 已提交
925

926
	nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
927 928
			&ipv6_hdr(skb)->saddr, th->source,
			&ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
929 930 931 932 933 934

	if (nsk) {
		if (nsk->sk_state != TCP_TIME_WAIT) {
			bh_lock_sock(nsk);
			return nsk;
		}
935
		inet_twsk_put(inet_twsk(nsk));
L
Linus Torvalds 已提交
936 937 938
		return NULL;
	}

939
#ifdef CONFIG_SYN_COOKIES
940
	if (!th->syn)
941
		sk = cookie_v6_check(sk, skb);
L
Linus Torvalds 已提交
942 943 944 945 946 947 948 949 950
#endif
	return sk;
}

/* FIXME: this is substantially similar to the ipv4 code.
 * Can some kind of merge be done? -- erics
 */
static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
{
951 952
	struct tcp_options_received tmp_opt;
	struct request_sock *req;
953
	struct inet_request_sock *ireq;
L
Linus Torvalds 已提交
954 955
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_sock *tp = tcp_sk(sk);
956
	__u32 isn = TCP_SKB_CB(skb)->when;
957
	struct dst_entry *dst = NULL;
958
	struct flowi6 fl6;
E
Eric Dumazet 已提交
959
	bool want_cookie = false;
L
Linus Torvalds 已提交
960 961 962 963 964

	if (skb->protocol == htons(ETH_P_IP))
		return tcp_v4_conn_request(sk, skb);

	if (!ipv6_unicast_destination(skb))
965
		goto drop;
L
Linus Torvalds 已提交
966

967 968
	if ((sysctl_tcp_syncookies == 2 ||
	     inet_csk_reqsk_queue_is_full(sk)) && !isn) {
969 970 971
		want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
		if (!want_cookie)
			goto drop;
L
Linus Torvalds 已提交
972 973
	}

974 975
	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
L
Linus Torvalds 已提交
976
		goto drop;
977
	}
L
Linus Torvalds 已提交
978

979
	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
L
Linus Torvalds 已提交
980 981 982
	if (req == NULL)
		goto drop;

983 984 985 986
#ifdef CONFIG_TCP_MD5SIG
	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
#endif

L
Linus Torvalds 已提交
987 988 989
	tcp_clear_options(&tmp_opt);
	tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
	tmp_opt.user_mss = tp->rx_opt.user_mss;
C
Christoph Paasch 已提交
990
	tcp_parse_options(skb, &tmp_opt, 0, NULL);
L
Linus Torvalds 已提交
991

992
	if (want_cookie && !tmp_opt.saw_tstamp)
993 994
		tcp_clear_options(&tmp_opt);

L
Linus Torvalds 已提交
995 996 997
	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
	tcp_openreq_init(req, &tmp_opt, skb);

998 999 1000
	ireq = inet_rsk(req);
	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
1001
	if (!want_cookie || tmp_opt.tstamp_ok)
1002
		TCP_ECN_create_request(req, skb, sock_net(sk));
1003

1004
	ireq->ir_iif = sk->sk_bound_dev_if;
1005 1006 1007

	/* So that link locals have meaning */
	if (!sk->sk_bound_dev_if &&
1008 1009
	    ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
		ireq->ir_iif = inet6_iif(skb);
1010

1011
	if (!isn) {
1012 1013 1014 1015
		if (ipv6_opt_accepted(sk, skb) ||
		    np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
		    np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
			atomic_inc(&skb->users);
1016
			ireq->pktopts = skb;
1017
		}
1018 1019

		if (want_cookie) {
1020 1021
			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
			req->cookie_ts = tmp_opt.tstamp_ok;
1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
			goto have_isn;
		}

		/* VJ's idea. We save last timestamp seen
		 * from the destination in peer table, when entering
		 * state TIME-WAIT, and check against it before
		 * accepting new connection request.
		 *
		 * If "isn" is not zero, this request hit alive
		 * timewait bucket, so that all the necessary checks
		 * are made in the function processing timewait state.
		 */
		if (tmp_opt.saw_tstamp &&
		    tcp_death_row.sysctl_tw_recycle &&
1036 1037
		    (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
			if (!tcp_peer_is_proven(req, dst, true)) {
1038 1039 1040 1041 1042 1043 1044 1045
				NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
				goto drop_and_release;
			}
		}
		/* Kill the following clause, if you dislike this way. */
		else if (!sysctl_tcp_syncookies &&
			 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
			  (sysctl_max_syn_backlog >> 2)) &&
1046
			 !tcp_peer_is_proven(req, dst, false)) {
1047 1048 1049 1050 1051 1052 1053 1054
			/* Without syncookies last quarter of
			 * backlog is filled with destinations,
			 * proven to be alive.
			 * It means that we continue to communicate
			 * to destinations, already remembered
			 * to the moment of synflood.
			 */
			LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1055
				       &ireq->ir_v6_rmt_addr, ntohs(tcp_hdr(skb)->source));
1056
			goto drop_and_release;
1057
		}
1058 1059

		isn = tcp_v6_init_sequence(skb);
1060
	}
1061
have_isn:
1062
	tcp_rsk(req)->snt_isn = isn;
L
Linus Torvalds 已提交
1063

1064 1065
	if (security_inet_conn_request(sk, skb, req))
		goto drop_and_release;
1066

1067
	if (tcp_v6_send_synack(sk, dst, &fl6, req,
1068
			       skb_get_queue_mapping(skb)) ||
1069
	    want_cookie)
1070
		goto drop_and_free;
L
Linus Torvalds 已提交
1071

1072
	tcp_rsk(req)->snt_synack = tcp_time_stamp;
1073
	tcp_rsk(req)->listener = NULL;
1074 1075
	inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
	return 0;
L
Linus Torvalds 已提交
1076

1077 1078
drop_and_release:
	dst_release(dst);
1079 1080
drop_and_free:
	reqsk_free(req);
L
Linus Torvalds 已提交
1081
drop:
1082
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
L
Linus Torvalds 已提交
1083 1084 1085 1086
	return 0; /* don't send reset */
}

static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1087
					  struct request_sock *req,
L
Linus Torvalds 已提交
1088 1089
					  struct dst_entry *dst)
{
1090
	struct inet_request_sock *ireq;
L
Linus Torvalds 已提交
1091 1092 1093 1094 1095
	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
	struct tcp6_sock *newtcp6sk;
	struct inet_sock *newinet;
	struct tcp_sock *newtp;
	struct sock *newsk;
1096 1097 1098
#ifdef CONFIG_TCP_MD5SIG
	struct tcp_md5sig_key *key;
#endif
1099
	struct flowi6 fl6;
L
Linus Torvalds 已提交
1100 1101 1102 1103 1104 1105 1106 1107

	if (skb->protocol == htons(ETH_P_IP)) {
		/*
		 *	v6 mapped
		 */

		newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);

1108
		if (newsk == NULL)
L
Linus Torvalds 已提交
1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119
			return NULL;

		newtcp6sk = (struct tcp6_sock *)newsk;
		inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;

		newinet = inet_sk(newsk);
		newnp = inet6_sk(newsk);
		newtp = tcp_sk(newsk);

		memcpy(newnp, np, sizeof(struct ipv6_pinfo));

1120
		ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
L
Linus Torvalds 已提交
1121

E
Eric Dumazet 已提交
1122
		ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
L
Linus Torvalds 已提交
1123

1124
		newsk->sk_v6_rcv_saddr = newnp->saddr;
L
Linus Torvalds 已提交
1125

1126
		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
L
Linus Torvalds 已提交
1127
		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1128 1129 1130 1131
#ifdef CONFIG_TCP_MD5SIG
		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif

1132 1133
		newnp->ipv6_ac_list = NULL;
		newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1134 1135
		newnp->pktoptions  = NULL;
		newnp->opt	   = NULL;
1136
		newnp->mcast_oif   = inet6_iif(skb);
1137
		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1138
		newnp->rcv_tclass  = ipv6_get_dsfield(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1139

1140 1141 1142 1143
		/*
		 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
		 * here, tcp_create_openreq_child now does this for us, see the comment in
		 * that function for the gory details. -acme
L
Linus Torvalds 已提交
1144 1145 1146
		 */

		/* It is tricky place. Until this moment IPv4 tcp
1147
		   worked with IPv6 icsk.icsk_af_ops.
L
Linus Torvalds 已提交
1148 1149
		   Sync it now.
		 */
1150
		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
L
Linus Torvalds 已提交
1151 1152 1153 1154

		return newsk;
	}

1155
	ireq = inet_rsk(req);
L
Linus Torvalds 已提交
1156 1157 1158 1159

	if (sk_acceptq_is_full(sk))
		goto out_overflow;

1160
	if (!dst) {
1161
		dst = inet6_csk_route_req(sk, &fl6, req);
1162
		if (!dst)
L
Linus Torvalds 已提交
1163
			goto out;
1164
	}
L
Linus Torvalds 已提交
1165 1166 1167

	newsk = tcp_create_openreq_child(sk, req, skb);
	if (newsk == NULL)
1168
		goto out_nonewsk;
L
Linus Torvalds 已提交
1169

1170 1171 1172 1173 1174
	/*
	 * No need to charge this sock to the relevant IPv6 refcnt debug socks
	 * count here, tcp_create_openreq_child now does this for us, see the
	 * comment in that function for the gory details. -acme
	 */
L
Linus Torvalds 已提交
1175

1176
	newsk->sk_gso_type = SKB_GSO_TCPV6;
1177
	__ip6_dst_store(newsk, dst, NULL, NULL);
1178
	inet6_sk_rx_dst_set(newsk, skb);
L
Linus Torvalds 已提交
1179 1180 1181 1182 1183 1184 1185 1186 1187 1188

	newtcp6sk = (struct tcp6_sock *)newsk;
	inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;

	newtp = tcp_sk(newsk);
	newinet = inet_sk(newsk);
	newnp = inet6_sk(newsk);

	memcpy(newnp, np, sizeof(struct ipv6_pinfo));

1189 1190 1191 1192
	newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
	newnp->saddr = ireq->ir_v6_loc_addr;
	newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
	newsk->sk_bound_dev_if = ireq->ir_iif;
L
Linus Torvalds 已提交
1193

1194
	/* Now IPv6 options...
L
Linus Torvalds 已提交
1195 1196 1197

	   First: no IPv4 options.
	 */
1198
	newinet->inet_opt = NULL;
1199
	newnp->ipv6_ac_list = NULL;
1200
	newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1201 1202 1203 1204 1205 1206

	/* Clone RX bits */
	newnp->rxopt.all = np->rxopt.all;

	/* Clone pktoptions received with SYN */
	newnp->pktoptions = NULL;
1207 1208
	if (ireq->pktopts != NULL) {
		newnp->pktoptions = skb_clone(ireq->pktopts,
1209
					      sk_gfp_atomic(sk, GFP_ATOMIC));
1210 1211
		consume_skb(ireq->pktopts);
		ireq->pktopts = NULL;
L
Linus Torvalds 已提交
1212 1213 1214 1215
		if (newnp->pktoptions)
			skb_set_owner_r(newnp->pktoptions, newsk);
	}
	newnp->opt	  = NULL;
1216
	newnp->mcast_oif  = inet6_iif(skb);
1217
	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1218
	newnp->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1219 1220 1221 1222 1223 1224 1225

	/* Clone native IPv6 options from listening socket (if any)

	   Yes, keeping reference count would be much more clever,
	   but we make one more one thing there: reattach optmem
	   to newsk.
	 */
1226 1227
	if (np->opt)
		newnp->opt = ipv6_dup_options(newsk, np->opt);
L
Linus Torvalds 已提交
1228

1229
	inet_csk(newsk)->icsk_ext_hdr_len = 0;
L
Linus Torvalds 已提交
1230
	if (newnp->opt)
1231 1232
		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
						     newnp->opt->opt_flen);
L
Linus Torvalds 已提交
1233

J
John Heffner 已提交
1234
	tcp_mtup_init(newsk);
L
Linus Torvalds 已提交
1235
	tcp_sync_mss(newsk, dst_mtu(dst));
1236
	newtp->advmss = dst_metric_advmss(dst);
1237 1238 1239 1240
	if (tcp_sk(sk)->rx_opt.user_mss &&
	    tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
		newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;

L
Linus Torvalds 已提交
1241 1242
	tcp_initialize_rcv_mss(newsk);

E
Eric Dumazet 已提交
1243 1244
	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
L
Linus Torvalds 已提交
1245

1246 1247
#ifdef CONFIG_TCP_MD5SIG
	/* Copy over the MD5 key from the original socket */
1248
	if ((key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr)) != NULL) {
1249 1250 1251 1252 1253
		/* We're using one, so create a matching key
		 * on the newsk structure. If we fail to get
		 * memory, then we end up not copying the key
		 * across. Shucks.
		 */
1254
		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1255 1256
			       AF_INET6, key->key, key->keylen,
			       sk_gfp_atomic(sk, GFP_ATOMIC));
1257 1258 1259
	}
#endif

1260
	if (__inet_inherit_port(sk, newsk) < 0) {
1261 1262
		inet_csk_prepare_forced_close(newsk);
		tcp_done(newsk);
1263 1264
		goto out;
	}
1265
	__inet6_hash(newsk, NULL);
L
Linus Torvalds 已提交
1266 1267 1268 1269

	return newsk;

out_overflow:
1270
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1271
out_nonewsk:
L
Linus Torvalds 已提交
1272
	dst_release(dst);
1273 1274
out:
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
L
Linus Torvalds 已提交
1275 1276 1277
	return NULL;
}

1278
static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
L
Linus Torvalds 已提交
1279
{
1280
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
H
Herbert Xu 已提交
1281
		if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1282
				  &ipv6_hdr(skb)->daddr, skb->csum)) {
1283
			skb->ip_summed = CHECKSUM_UNNECESSARY;
L
Linus Torvalds 已提交
1284
			return 0;
1285
		}
L
Linus Torvalds 已提交
1286
	}
1287

H
Herbert Xu 已提交
1288
	skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1289 1290
					      &ipv6_hdr(skb)->saddr,
					      &ipv6_hdr(skb)->daddr, 0));
1291

L
Linus Torvalds 已提交
1292
	if (skb->len <= 76) {
1293
		return __skb_checksum_complete(skb);
L
Linus Torvalds 已提交
1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
	}
	return 0;
}

/* The socket must have it's spinlock held when we get
 * here.
 *
 * We have a potential double-lock case here, so even when
 * doing backlog processing we use the BH locking scheme.
 * This is because we cannot sleep with the original spinlock
 * held.
 */
static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_sock *tp;
	struct sk_buff *opt_skb = NULL;

	/* Imagine: socket is IPv6. IPv4 packet arrives,
	   goes to IPv4 receive handler and backlogged.
	   From backlog it always goes here. Kerboom...
	   Fortunately, tcp_rcv_established and rcv_established
	   handle them correctly, but it is not case with
	   tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
	 */

	if (skb->protocol == htons(ETH_P_IP))
		return tcp_v4_do_rcv(sk, skb);

1323 1324 1325 1326 1327
#ifdef CONFIG_TCP_MD5SIG
	if (tcp_v6_inbound_md5_hash (sk, skb))
		goto discard;
#endif

1328
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346
		goto discard;

	/*
	 *	socket locking is here for SMP purposes as backlog rcv
	 *	is currently called with bh processing disabled.
	 */

	/* Do Stevens' IPV6_PKTOPTIONS.

	   Yes, guys, it is the only place in our code, where we
	   may make it not affecting IPv4.
	   The rest of code is protocol independent,
	   and I do not like idea to uglify IPv4.

	   Actually, all the idea behind IPV6_PKTOPTIONS
	   looks not very well thought. For now we latch
	   options, received in the last packet, enqueued
	   by tcp. Feel free to propose better solution.
1347
					       --ANK (980728)
L
Linus Torvalds 已提交
1348 1349
	 */
	if (np->rxopt.all)
1350
		opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
L
Linus Torvalds 已提交
1351 1352

	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
E
Eric Dumazet 已提交
1353 1354
		struct dst_entry *dst = sk->sk_rx_dst;

1355
		sock_rps_save_rxhash(sk, skb);
E
Eric Dumazet 已提交
1356 1357 1358 1359 1360 1361 1362 1363
		if (dst) {
			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
			    dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
				dst_release(dst);
				sk->sk_rx_dst = NULL;
			}
		}

1364
		tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
L
Linus Torvalds 已提交
1365 1366 1367 1368 1369
		if (opt_skb)
			goto ipv6_pktoptions;
		return 0;
	}

1370
	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
L
Linus Torvalds 已提交
1371 1372
		goto csum_err;

1373
	if (sk->sk_state == TCP_LISTEN) {
L
Linus Torvalds 已提交
1374 1375 1376 1377 1378 1379 1380 1381 1382
		struct sock *nsk = tcp_v6_hnd_req(sk, skb);
		if (!nsk)
			goto discard;

		/*
		 * Queue it on the new socket if the new socket is active,
		 * otherwise we just shortcircuit this and continue with
		 * the new socket..
		 */
1383
		if(nsk != sk) {
1384
			sock_rps_save_rxhash(nsk, skb);
L
Linus Torvalds 已提交
1385 1386 1387 1388 1389 1390
			if (tcp_child_process(sk, nsk, skb))
				goto reset;
			if (opt_skb)
				__kfree_skb(opt_skb);
			return 0;
		}
1391
	} else
1392
		sock_rps_save_rxhash(sk, skb);
L
Linus Torvalds 已提交
1393

1394
	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1395 1396 1397 1398 1399 1400
		goto reset;
	if (opt_skb)
		goto ipv6_pktoptions;
	return 0;

reset:
1401
	tcp_v6_send_reset(sk, skb);
L
Linus Torvalds 已提交
1402 1403 1404 1405 1406 1407
discard:
	if (opt_skb)
		__kfree_skb(opt_skb);
	kfree_skb(skb);
	return 0;
csum_err:
1408
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1409
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
	goto discard;


ipv6_pktoptions:
	/* Do you ask, what is it?

	   1. skb was enqueued by tcp.
	   2. skb is added to tail of read queue, rather than out of order.
	   3. socket is not in passive state.
	   4. Finally, it really contains options, which user wants to receive.
	 */
	tp = tcp_sk(sk);
	if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
	    !((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(opt_skb));
L
Linus Torvalds 已提交
1430 1431 1432 1433 1434 1435 1436 1437 1438
		if (ipv6_opt_accepted(sk, opt_skb)) {
			skb_set_owner_r(opt_skb, sk);
			opt_skb = xchg(&np->pktoptions, opt_skb);
		} else {
			__kfree_skb(opt_skb);
			opt_skb = xchg(&np->pktoptions, NULL);
		}
	}

1439
	kfree_skb(opt_skb);
L
Linus Torvalds 已提交
1440 1441 1442
	return 0;
}

1443
static int tcp_v6_rcv(struct sk_buff *skb)
L
Linus Torvalds 已提交
1444
{
1445
	const struct tcphdr *th;
1446
	const struct ipv6hdr *hdr;
L
Linus Torvalds 已提交
1447 1448
	struct sock *sk;
	int ret;
1449
	struct net *net = dev_net(skb->dev);
L
Linus Torvalds 已提交
1450 1451 1452 1453 1454 1455 1456

	if (skb->pkt_type != PACKET_HOST)
		goto discard_it;

	/*
	 *	Count it even if it's bad.
	 */
1457
	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
L
Linus Torvalds 已提交
1458 1459 1460 1461

	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
		goto discard_it;

1462
	th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1463 1464 1465 1466 1467 1468

	if (th->doff < sizeof(struct tcphdr)/4)
		goto bad_packet;
	if (!pskb_may_pull(skb, th->doff*4))
		goto discard_it;

1469
	if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1470
		goto csum_error;
L
Linus Torvalds 已提交
1471

1472
	th = tcp_hdr(skb);
1473
	hdr = ipv6_hdr(skb);
L
Linus Torvalds 已提交
1474 1475 1476 1477 1478
	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
				    skb->len - th->doff*4);
	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
	TCP_SKB_CB(skb)->when = 0;
1479
	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
L
Linus Torvalds 已提交
1480 1481
	TCP_SKB_CB(skb)->sacked = 0;

1482
	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
L
Linus Torvalds 已提交
1483 1484 1485 1486 1487 1488 1489
	if (!sk)
		goto no_tcp_socket;

process:
	if (sk->sk_state == TCP_TIME_WAIT)
		goto do_time_wait;

1490 1491 1492 1493 1494
	if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
		NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
		goto discard_and_relse;
	}

L
Linus Torvalds 已提交
1495 1496 1497
	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_and_relse;

1498
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1499 1500
		goto discard_and_relse;

1501
	sk_mark_napi_id(sk, skb);
L
Linus Torvalds 已提交
1502 1503
	skb->dev = NULL;

1504
	bh_lock_sock_nested(sk);
L
Linus Torvalds 已提交
1505 1506
	ret = 0;
	if (!sock_owned_by_user(sk)) {
C
Chris Leech 已提交
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 1512 1513
		if (tp->ucopy.dma_chan)
			ret = tcp_v6_do_rcv(sk, skb);
		else
C
Chris Leech 已提交
1514 1515 1516 1517 1518
#endif
		{
			if (!tcp_prequeue(sk, skb))
				ret = tcp_v6_do_rcv(sk, skb);
		}
1519 1520
	} else if (unlikely(sk_add_backlog(sk, skb,
					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
Z
Zhu Yi 已提交
1521
		bh_unlock_sock(sk);
1522
		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
Z
Zhu Yi 已提交
1523 1524
		goto discard_and_relse;
	}
L
Linus Torvalds 已提交
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534
	bh_unlock_sock(sk);

	sock_put(sk);
	return ret ? -1 : 0;

no_tcp_socket:
	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
		goto discard_it;

	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1535 1536
csum_error:
		TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
L
Linus Torvalds 已提交
1537
bad_packet:
1538
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1539
	} else {
1540
		tcp_v6_send_reset(NULL, skb);
L
Linus Torvalds 已提交
1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552
	}

discard_it:
	kfree_skb(skb);
	return 0;

discard_and_relse:
	sock_put(sk);
	goto discard_it;

do_time_wait:
	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1553
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1554 1555 1556
		goto discard_it;
	}

1557
	if (skb->len < (th->doff<<2)) {
1558
		inet_twsk_put(inet_twsk(sk));
1559 1560 1561 1562 1563
		goto bad_packet;
	}
	if (tcp_checksum_complete(skb)) {
		inet_twsk_put(inet_twsk(sk));
		goto csum_error;
L
Linus Torvalds 已提交
1564 1565
	}

1566
	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
L
Linus Torvalds 已提交
1567 1568 1569 1570
	case TCP_TW_SYN:
	{
		struct sock *sk2;

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));
L
Linus Torvalds 已提交
1575
		if (sk2 != NULL) {
1576 1577 1578
			struct inet_timewait_sock *tw = inet_twsk(sk);
			inet_twsk_deschedule(tw, &tcp_death_row);
			inet_twsk_put(tw);
L
Linus Torvalds 已提交
1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
			sk = sk2;
			goto process;
		}
		/* Fall through to ACK */
	}
	case TCP_TW_ACK:
		tcp_v6_timewait_ack(sk, skb);
		break;
	case TCP_TW_RST:
		goto no_tcp_socket;
	case TCP_TW_SUCCESS:;
	}
	goto discard_it;
}

E
Eric Dumazet 已提交
1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620
static void tcp_v6_early_demux(struct sk_buff *skb)
{
	const struct ipv6hdr *hdr;
	const struct tcphdr *th;
	struct sock *sk;

	if (skb->pkt_type != PACKET_HOST)
		return;

	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
		return;

	hdr = ipv6_hdr(skb);
	th = tcp_hdr(skb);

	if (th->doff < sizeof(struct tcphdr) / 4)
		return;

	sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
					&hdr->saddr, th->source,
					&hdr->daddr, ntohs(th->dest),
					inet6_iif(skb));
	if (sk) {
		skb->sk = sk;
		skb->destructor = sock_edemux;
		if (sk->sk_state != TCP_TIME_WAIT) {
			struct dst_entry *dst = sk->sk_rx_dst;
1621

E
Eric Dumazet 已提交
1622
			if (dst)
E
Eric Dumazet 已提交
1623
				dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
E
Eric Dumazet 已提交
1624
			if (dst &&
1625
			    inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
E
Eric Dumazet 已提交
1626 1627 1628 1629 1630
				skb_dst_set_noref(skb, dst);
		}
	}
}

1631 1632 1633 1634 1635 1636
static struct timewait_sock_ops tcp6_timewait_sock_ops = {
	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
	.twsk_unique	= tcp_twsk_unique,
	.twsk_destructor= tcp_twsk_destructor,
};

1637
static const struct inet_connection_sock_af_ops ipv6_specific = {
1638 1639 1640
	.queue_xmit	   = inet6_csk_xmit,
	.send_check	   = tcp_v6_send_check,
	.rebuild_header	   = inet6_sk_rebuild_header,
E
Eric Dumazet 已提交
1641
	.sk_rx_dst_set	   = inet6_sk_rx_dst_set,
1642 1643 1644
	.conn_request	   = tcp_v6_conn_request,
	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
	.net_header_len	   = sizeof(struct ipv6hdr),
1645
	.net_frag_header_len = sizeof(struct frag_hdr),
1646 1647 1648 1649
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1650
	.bind_conflict	   = inet6_csk_bind_conflict,
1651
#ifdef CONFIG_COMPAT
1652 1653
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1654
#endif
L
Linus Torvalds 已提交
1655 1656
};

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 1662
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1663
#endif
1664

L
Linus Torvalds 已提交
1665 1666 1667 1668
/*
 *	TCP over IPv4 via INET6 API
 */

1669
static const struct inet_connection_sock_af_ops ipv6_mapped = {
1670 1671 1672
	.queue_xmit	   = ip_queue_xmit,
	.send_check	   = tcp_v4_send_check,
	.rebuild_header	   = inet_sk_rebuild_header,
1673
	.sk_rx_dst_set	   = inet_sk_rx_dst_set,
1674 1675 1676 1677 1678 1679 1680
	.conn_request	   = tcp_v6_conn_request,
	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
	.net_header_len	   = sizeof(struct iphdr),
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1681
	.bind_conflict	   = inet6_csk_bind_conflict,
1682
#ifdef CONFIG_COMPAT
1683 1684
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1685
#endif
L
Linus Torvalds 已提交
1686 1687
};

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 1693
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1694
#endif
1695

L
Linus Torvalds 已提交
1696 1697 1698 1699 1700
/* NOTE: A lot of things set to zero explicitly by call to
 *       sk_alloc() so need not be done here.
 */
static int tcp_v6_init_sock(struct sock *sk)
{
1701
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1702

1703
	tcp_init_sock(sk);
L
Linus Torvalds 已提交
1704

1705
	icsk->icsk_af_ops = &ipv6_specific;
L
Linus Torvalds 已提交
1706

1707
#ifdef CONFIG_TCP_MD5SIG
1708
	tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1709 1710
#endif

L
Linus Torvalds 已提交
1711 1712 1713
	return 0;
}

1714
static void tcp_v6_destroy_sock(struct sock *sk)
L
Linus Torvalds 已提交
1715 1716
{
	tcp_v4_destroy_sock(sk);
1717
	inet6_destroy_sock(sk);
L
Linus Torvalds 已提交
1718 1719
}

1720
#ifdef CONFIG_PROC_FS
L
Linus Torvalds 已提交
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)
L
Linus Torvalds 已提交
1724 1725
{
	int ttd = req->expires - jiffies;
1726 1727
	const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
	const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
L
Linus Torvalds 已提交
1728 1729 1730 1731 1732 1733

	if (ttd < 0)
		ttd = 0;

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1734
		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1735 1736 1737
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3],
1738
		   ntohs(inet_rsk(req)->ir_loc_port),
L
Linus Torvalds 已提交
1739 1740
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3],
1741
		   ntohs(inet_rsk(req)->ir_rmt_port),
L
Linus Torvalds 已提交
1742 1743
		   TCP_SYN_RECV,
		   0,0, /* could print option size, but that is af dependent. */
1744 1745
		   1,   /* timers active (only the expire timer) */
		   jiffies_to_clock_t(ttd),
1746
		   req->num_timeout,
1747
		   from_kuid_munged(seq_user_ns(seq), uid),
1748
		   0,  /* non standard timer */
L
Linus Torvalds 已提交
1749 1750 1751 1752 1753 1754
		   0, /* open_requests have no inode */
		   0, req);
}

static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
{
1755
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1756 1757 1758
	__u16 destp, srcp;
	int timer_active;
	unsigned long timer_expires;
1759 1760
	const struct inet_sock *inet = inet_sk(sp);
	const struct tcp_sock *tp = tcp_sk(sp);
1761
	const struct inet_connection_sock *icsk = inet_csk(sp);
L
Linus Torvalds 已提交
1762

1763 1764
	dest  = &sp->sk_v6_daddr;
	src   = &sp->sk_v6_rcv_saddr;
E
Eric Dumazet 已提交
1765 1766
	destp = ntohs(inet->inet_dport);
	srcp  = ntohs(inet->inet_sport);
1767 1768

	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
L
Linus Torvalds 已提交
1769
		timer_active	= 1;
1770 1771
		timer_expires	= icsk->icsk_timeout;
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
L
Linus Torvalds 已提交
1772
		timer_active	= 4;
1773
		timer_expires	= icsk->icsk_timeout;
L
Linus Torvalds 已提交
1774 1775 1776 1777 1778 1779 1780 1781 1782 1783
	} else if (timer_pending(&sp->sk_timer)) {
		timer_active	= 2;
		timer_expires	= sp->sk_timer.expires;
	} else {
		timer_active	= 0;
		timer_expires = jiffies;
	}

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1784
		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
L
Linus Torvalds 已提交
1785 1786 1787 1788 1789
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3], srcp,
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1790
		   sp->sk_state,
1791 1792
		   tp->write_seq-tp->snd_una,
		   (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
L
Linus Torvalds 已提交
1793
		   timer_active,
1794
		   jiffies_delta_to_clock_t(timer_expires - jiffies),
1795
		   icsk->icsk_retransmits,
1796
		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1797
		   icsk->icsk_probes_out,
L
Linus Torvalds 已提交
1798 1799
		   sock_i_ino(sp),
		   atomic_read(&sp->sk_refcnt), sp,
1800 1801
		   jiffies_to_clock_t(icsk->icsk_rto),
		   jiffies_to_clock_t(icsk->icsk_ack.ato),
1802
		   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
I
Ilpo Järvinen 已提交
1803 1804
		   tp->snd_cwnd,
		   tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
L
Linus Torvalds 已提交
1805 1806 1807
		   );
}

1808
static void get_timewait6_sock(struct seq_file *seq,
1809
			       struct inet_timewait_sock *tw, int i)
L
Linus Torvalds 已提交
1810
{
1811
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1812
	__u16 destp, srcp;
1813
	s32 delta = tw->tw_ttd - inet_tw_time_stamp();
L
Linus Torvalds 已提交
1814

1815 1816
	dest = &tw->tw_v6_daddr;
	src  = &tw->tw_v6_rcv_saddr;
L
Linus Torvalds 已提交
1817 1818 1819 1820 1821
	destp = ntohs(tw->tw_dport);
	srcp  = ntohs(tw->tw_sport);

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
D
Dan Rosenberg 已提交
1822
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1823 1824 1825 1826 1827 1828
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3], srcp,
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
		   tw->tw_substate, 0, 0,
1829
		   3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
L
Linus Torvalds 已提交
1830 1831 1832 1833 1834 1835
		   atomic_read(&tw->tw_refcnt), tw);
}

static int tcp6_seq_show(struct seq_file *seq, void *v)
{
	struct tcp_iter_state *st;
E
Eric Dumazet 已提交
1836
	struct sock *sk = v;
L
Linus Torvalds 已提交
1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851

	if (v == SEQ_START_TOKEN) {
		seq_puts(seq,
			 "  sl  "
			 "local_address                         "
			 "remote_address                        "
			 "st tx_queue rx_queue tr tm->when retrnsmt"
			 "   uid  timeout inode\n");
		goto out;
	}
	st = seq->private;

	switch (st->state) {
	case TCP_SEQ_STATE_LISTENING:
	case TCP_SEQ_STATE_ESTABLISHED:
E
Eric Dumazet 已提交
1852 1853 1854 1855
		if (sk->sk_state == TCP_TIME_WAIT)
			get_timewait6_sock(seq, v, st->num);
		else
			get_tcp6_sock(seq, v, st->num);
L
Linus Torvalds 已提交
1856 1857 1858 1859 1860 1861 1862 1863 1864
		break;
	case TCP_SEQ_STATE_OPENREQ:
		get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
		break;
	}
out:
	return 0;
}

1865 1866 1867 1868 1869 1870 1871 1872
static const struct file_operations tcp6_afinfo_seq_fops = {
	.owner   = THIS_MODULE,
	.open    = tcp_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release_net
};

L
Linus Torvalds 已提交
1873 1874 1875
static struct tcp_seq_afinfo tcp6_seq_afinfo = {
	.name		= "tcp6",
	.family		= AF_INET6,
1876
	.seq_fops	= &tcp6_afinfo_seq_fops,
1877 1878 1879
	.seq_ops	= {
		.show		= tcp6_seq_show,
	},
L
Linus Torvalds 已提交
1880 1881
};

1882
int __net_init tcp6_proc_init(struct net *net)
L
Linus Torvalds 已提交
1883
{
1884
	return tcp_proc_register(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
1885 1886
}

1887
void tcp6_proc_exit(struct net *net)
L
Linus Torvalds 已提交
1888
{
1889
	tcp_proc_unregister(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
1890 1891 1892
}
#endif

E
Eric Dumazet 已提交
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903
static void tcp_v6_clear_sk(struct sock *sk, int size)
{
	struct inet_sock *inet = inet_sk(sk);

	/* we do not want to clear pinet6 field, because of RCU lookups */
	sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));

	size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
	memset(&inet->pinet6 + 1, 0, size);
}

L
Linus Torvalds 已提交
1904 1905 1906 1907 1908 1909
struct proto tcpv6_prot = {
	.name			= "TCPv6",
	.owner			= THIS_MODULE,
	.close			= tcp_close,
	.connect		= tcp_v6_connect,
	.disconnect		= tcp_disconnect,
1910
	.accept			= inet_csk_accept,
L
Linus Torvalds 已提交
1911 1912 1913 1914 1915 1916 1917
	.ioctl			= tcp_ioctl,
	.init			= tcp_v6_init_sock,
	.destroy		= tcp_v6_destroy_sock,
	.shutdown		= tcp_shutdown,
	.setsockopt		= tcp_setsockopt,
	.getsockopt		= tcp_getsockopt,
	.recvmsg		= tcp_recvmsg,
1918 1919
	.sendmsg		= tcp_sendmsg,
	.sendpage		= tcp_sendpage,
L
Linus Torvalds 已提交
1920
	.backlog_rcv		= tcp_v6_do_rcv,
E
Eric Dumazet 已提交
1921
	.release_cb		= tcp_release_cb,
1922
	.mtu_reduced		= tcp_v6_mtu_reduced,
L
Linus Torvalds 已提交
1923
	.hash			= tcp_v6_hash,
1924 1925
	.unhash			= inet_unhash,
	.get_port		= inet_csk_get_port,
L
Linus Torvalds 已提交
1926
	.enter_memory_pressure	= tcp_enter_memory_pressure,
1927
	.stream_memory_free	= tcp_stream_memory_free,
L
Linus Torvalds 已提交
1928 1929 1930
	.sockets_allocated	= &tcp_sockets_allocated,
	.memory_allocated	= &tcp_memory_allocated,
	.memory_pressure	= &tcp_memory_pressure,
1931
	.orphan_count		= &tcp_orphan_count,
L
Linus Torvalds 已提交
1932 1933 1934 1935
	.sysctl_wmem		= sysctl_tcp_wmem,
	.sysctl_rmem		= sysctl_tcp_rmem,
	.max_header		= MAX_TCP_HEADER,
	.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 1942 1943 1944
#ifdef CONFIG_COMPAT
	.compat_setsockopt	= compat_tcp_setsockopt,
	.compat_getsockopt	= compat_tcp_getsockopt,
#endif
A
Andrew Morton 已提交
1945
#ifdef CONFIG_MEMCG_KMEM
G
Glauber Costa 已提交
1946 1947
	.proto_cgroup		= tcp_proto_cgroup,
#endif
E
Eric Dumazet 已提交
1948
	.clear_sk		= tcp_v6_clear_sk,
L
Linus Torvalds 已提交
1949 1950
};

1951
static const struct inet6_protocol tcpv6_protocol = {
E
Eric Dumazet 已提交
1952
	.early_demux	=	tcp_v6_early_demux,
L
Linus Torvalds 已提交
1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963
	.handler	=	tcp_v6_rcv,
	.err_handler	=	tcp_v6_err,
	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};

static struct inet_protosw tcpv6_protosw = {
	.type		=	SOCK_STREAM,
	.protocol	=	IPPROTO_TCP,
	.prot		=	&tcpv6_prot,
	.ops		=	&inet6_stream_ops,
	.no_check	=	0,
1964 1965
	.flags		=	INET_PROTOSW_PERMANENT |
				INET_PROTOSW_ICSK,
L
Linus Torvalds 已提交
1966 1967
};

1968
static int __net_init tcpv6_net_init(struct net *net)
1969
{
1970 1971
	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
				    SOCK_RAW, IPPROTO_TCP, net);
1972 1973
}

1974
static void __net_exit tcpv6_net_exit(struct net *net)
1975
{
1976
	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
E
Eric W. Biederman 已提交
1977 1978
}

1979
static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
E
Eric W. Biederman 已提交
1980 1981
{
	inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1982 1983 1984
}

static struct pernet_operations tcpv6_net_ops = {
E
Eric W. Biederman 已提交
1985 1986 1987
	.init	    = tcpv6_net_init,
	.exit	    = tcpv6_net_exit,
	.exit_batch = tcpv6_net_exit_batch,
1988 1989
};

1990
int __init tcpv6_init(void)
L
Linus Torvalds 已提交
1991
{
1992 1993
	int ret;

1994 1995
	ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
	if (ret)
1996
		goto out;
1997

L
Linus Torvalds 已提交
1998
	/* register inet6 protocol */
1999 2000 2001 2002
	ret = inet6_register_protosw(&tcpv6_protosw);
	if (ret)
		goto out_tcpv6_protocol;

2003
	ret = register_pernet_subsys(&tcpv6_net_ops);
2004 2005 2006 2007
	if (ret)
		goto out_tcpv6_protosw;
out:
	return ret;
2008

2009 2010
out_tcpv6_protosw:
	inet6_unregister_protosw(&tcpv6_protosw);
2011 2012
out_tcpv6_protocol:
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2013 2014 2015
	goto out;
}

2016
void tcpv6_exit(void)
2017
{
2018
	unregister_pernet_subsys(&tcpv6_net_ops);
2019 2020
	inet6_unregister_protosw(&tcpv6_protosw);
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
L
Linus Torvalds 已提交
2021
}