tcp_ipv6.c 54.3 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 <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 void	__tcp_v6_send_check(struct sk_buff *skb,
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				    const struct in6_addr *saddr,
				    const struct in6_addr *daddr);
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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 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 __inline__ __sum16 tcp_v6_check(int len,
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				   const struct in6_addr *saddr,
				   const struct in6_addr *daddr,
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				   __wsum base)
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{
	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
}

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

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	np->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,
					       &np->rcv_saddr);
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		}

		return err;
	}

	if (!ipv6_addr_any(&np->rcv_saddr))
		saddr = &np->rcv_saddr;

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	fl6.flowi6_proto = IPPROTO_TCP;
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	fl6.daddr = np->daddr;
	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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		np->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 &&
	    ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
		struct inet_peer *peer = rt6_get_peer(rt);
		/*
		 * VJ's idea. We save last timestamp seen from
		 * the destination in peer table, when entering state
		 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
		 * when trying new connection.
		 */
		if (peer) {
			inet_peer_refcheck(peer);
			if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
				tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
				tp->rx_opt.ts_recent = peer->tcp_ts;
			}
		}
	}

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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;

	if (!tp->write_seq)
		tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
							     np->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;
}

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);
	if (sock_owned_by_user(sk))
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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);

	if (type == ICMPV6_PKT_TOOBIG) {
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		struct dst_entry *dst;
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		if (sock_owned_by_user(sk))
			goto out;
		if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
			goto out;

		/* icmp should have updated the destination cache entry */
		dst = __sk_dst_check(sk, np->dst_cookie);

		if (dst == NULL) {
			struct inet_sock *inet = inet_sk(sk);
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			struct flowi6 fl6;
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			/* BUGGG_FUTURE: Again, it is not clear how
			   to handle rthdr case. Ignore this complexity
			   for now.
			 */
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			memset(&fl6, 0, sizeof(fl6));
			fl6.flowi6_proto = IPPROTO_TCP;
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			fl6.daddr = np->daddr;
			fl6.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 = inet->inet_dport;
			fl6.fl6_sport = inet->inet_sport;
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			security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));

			dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
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			if (IS_ERR(dst)) {
				sk->sk_err_soft = -PTR_ERR(dst);
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				goto out;
			}

		} else
			dst_hold(dst);

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		if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
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			tcp_sync_mss(sk, dst_mtu(dst));
			tcp_simple_retransmit(sk);
		} /* else let the usual retransmit timer handle it */
		dst_release(dst);
		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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		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 request_sock *req,
			      struct request_values *rvp)
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{
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	struct inet6_request_sock *treq = inet6_rsk(req);
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	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff * skb;
	struct ipv6_txoptions *opt = NULL;
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	struct in6_addr * final_p, final;
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	struct flowi6 fl6;
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	struct dst_entry *dst;
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	int err;
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	memset(&fl6, 0, sizeof(fl6));
	fl6.flowi6_proto = IPPROTO_TCP;
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	fl6.daddr = treq->rmt_addr;
	fl6.saddr = treq->loc_addr;
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	fl6.flowlabel = 0;
	fl6.flowi6_oif = treq->iif;
	fl6.flowi6_mark = sk->sk_mark;
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	fl6.fl6_dport = inet_rsk(req)->rmt_port;
	fl6.fl6_sport = inet_rsk(req)->loc_port;
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	security_req_classify_flow(req, flowi6_to_flowi(&fl6));
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	opt = np->opt;
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	final_p = fl6_update_dst(&fl6, opt, &final);
L
Linus Torvalds 已提交
503

504
	dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
505 506
	if (IS_ERR(dst)) {
		err = PTR_ERR(dst);
507
		dst = NULL;
508
		goto done;
509
	}
510
	skb = tcp_make_synack(sk, dst, req, rvp);
511
	err = -ENOMEM;
L
Linus Torvalds 已提交
512
	if (skb) {
513
		__tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
L
Linus Torvalds 已提交
514

A
Alexey Dobriyan 已提交
515
		fl6.daddr = treq->rmt_addr;
516
		err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
517
		err = net_xmit_eval(err);
L
Linus Torvalds 已提交
518 519 520
	}

done:
521
	if (opt && opt != np->opt)
L
Linus Torvalds 已提交
522
		sock_kfree_s(sk, opt, opt->tot_len);
523
	dst_release(dst);
L
Linus Torvalds 已提交
524 525 526
	return err;
}

527 528 529 530 531 532 533
static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
			     struct request_values *rvp)
{
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
	return tcp_v6_send_synack(sk, req, rvp);
}

534
static void tcp_v6_reqsk_destructor(struct request_sock *req)
L
Linus Torvalds 已提交
535
{
536
	kfree_skb(inet6_rsk(req)->pktopts);
L
Linus Torvalds 已提交
537 538
}

539 540
#ifdef CONFIG_TCP_MD5SIG
static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
541
						   const struct in6_addr *addr)
542
{
E
Eric Dumazet 已提交
543
	return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
}

static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
						struct sock *addr_sk)
{
	return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
}

static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
						      struct request_sock *req)
{
	return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
}

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
574
		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
E
Eric Dumazet 已提交
575 576 577 578
			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);
579 580 581 582 583
	}

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

E
Eric Dumazet 已提交
584 585 586
	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);
587

E
Eric Dumazet 已提交
588 589
	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
			      AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
590 591
}

592
static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
593 594
					const struct in6_addr *daddr,
					const struct in6_addr *saddr, int nbytes)
595 596
{
	struct tcp6_pseudohdr *bp;
597
	struct scatterlist sg;
598

599 600
	bp = &hp->md5_blk.ip6;
	/* 1. TCP pseudo-header (RFC2460) */
A
Alexey Dobriyan 已提交
601 602
	bp->saddr = *saddr;
	bp->daddr = *daddr;
603
	bp->protocol = cpu_to_be32(IPPROTO_TCP);
A
Adam Langley 已提交
604
	bp->len = cpu_to_be32(nbytes);
605

606 607 608
	sg_init_one(&sg, bp, sizeof(*bp));
	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
}
609

610
static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
611
			       const struct in6_addr *daddr, struct in6_addr *saddr,
E
Eric Dumazet 已提交
612
			       const struct tcphdr *th)
613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630
{
	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))
631 632 633 634
		goto clear_hash;

	tcp_put_md5sig_pool();
	return 0;
635

636 637 638 639
clear_hash:
	tcp_put_md5sig_pool();
clear_hash_noput:
	memset(md5_hash, 0, 16);
640
	return 1;
641 642
}

643
static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
E
Eric Dumazet 已提交
644 645 646
			       const struct sock *sk,
			       const struct request_sock *req,
			       const struct sk_buff *skb)
647
{
648
	const struct in6_addr *saddr, *daddr;
649 650
	struct tcp_md5sig_pool *hp;
	struct hash_desc *desc;
E
Eric Dumazet 已提交
651
	const struct tcphdr *th = tcp_hdr(skb);
652 653 654 655

	if (sk) {
		saddr = &inet6_sk(sk)->saddr;
		daddr = &inet6_sk(sk)->daddr;
656
	} else if (req) {
657 658
		saddr = &inet6_rsk(req)->loc_addr;
		daddr = &inet6_rsk(req)->rmt_addr;
659
	} else {
660
		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
661 662
		saddr = &ip6h->saddr;
		daddr = &ip6h->daddr;
663
	}
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691

	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;
692 693
}

E
Eric Dumazet 已提交
694
static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
695
{
696
	const __u8 *hash_location = NULL;
697
	struct tcp_md5sig_key *hash_expected;
698
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
E
Eric Dumazet 已提交
699
	const struct tcphdr *th = tcp_hdr(skb);
700 701 702 703
	int genhash;
	u8 newhash[16];

	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
704
	hash_location = tcp_parse_md5sig_option(th);
705

706 707 708 709 710 711
	/* 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);
712 713 714
		return 1;
	}

715 716
	if (!hash_expected && hash_location) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
717 718 719 720
		return 1;
	}

	/* check the signature */
721 722 723 724
	genhash = tcp_v6_md5_hash_skb(newhash,
				      hash_expected,
				      NULL, NULL, skb);

725 726
	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
		if (net_ratelimit()) {
727
			printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
728
			       genhash ? "failed" : "mismatch",
729 730
			       &ip6h->saddr, ntohs(th->source),
			       &ip6h->daddr, ntohs(th->dest));
731 732 733 734 735 736 737
		}
		return 1;
	}
	return 0;
}
#endif

738
struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
L
Linus Torvalds 已提交
739
	.family		=	AF_INET6,
740
	.obj_size	=	sizeof(struct tcp6_request_sock),
741
	.rtx_syn_ack	=	tcp_v6_rtx_synack,
742 743
	.send_ack	=	tcp_v6_reqsk_send_ack,
	.destructor	=	tcp_v6_reqsk_destructor,
744 745
	.send_reset	=	tcp_v6_send_reset,
	.syn_ack_timeout = 	tcp_syn_ack_timeout,
L
Linus Torvalds 已提交
746 747
};

748
#ifdef CONFIG_TCP_MD5SIG
749
static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
750
	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
751
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
752
};
753
#endif
754

755
static void __tcp_v6_send_check(struct sk_buff *skb,
756
				const struct in6_addr *saddr, const struct in6_addr *daddr)
L
Linus Torvalds 已提交
757
{
758
	struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
759

760
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
761
		th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
762
		skb->csum_start = skb_transport_header(skb) - skb->head;
A
Al Viro 已提交
763
		skb->csum_offset = offsetof(struct tcphdr, check);
L
Linus Torvalds 已提交
764
	} else {
765 766 767
		th->check = tcp_v6_check(skb->len, saddr, daddr,
					 csum_partial(th, th->doff << 2,
						      skb->csum));
L
Linus Torvalds 已提交
768 769 770
	}
}

771
static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
772 773 774 775 776 777
{
	struct ipv6_pinfo *np = inet6_sk(sk);

	__tcp_v6_send_check(skb, &np->saddr, &np->daddr);
}

778 779
static int tcp_v6_gso_send_check(struct sk_buff *skb)
{
780
	const struct ipv6hdr *ipv6h;
781 782 783 784 785
	struct tcphdr *th;

	if (!pskb_may_pull(skb, sizeof(*th)))
		return -EINVAL;

786
	ipv6h = ipv6_hdr(skb);
787
	th = tcp_hdr(skb);
788 789

	th->check = 0;
790
	skb->ip_summed = CHECKSUM_PARTIAL;
791
	__tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
792 793
	return 0;
}
L
Linus Torvalds 已提交
794

H
Herbert Xu 已提交
795 796
static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
					 struct sk_buff *skb)
H
Herbert Xu 已提交
797
{
798
	const struct ipv6hdr *iph = skb_gro_network_header(skb);
H
Herbert Xu 已提交
799 800 801

	switch (skb->ip_summed) {
	case CHECKSUM_COMPLETE:
802
		if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
H
Herbert Xu 已提交
803 804 805 806 807 808 809 810 811 812 813 814 815 816
				  skb->csum)) {
			skb->ip_summed = CHECKSUM_UNNECESSARY;
			break;
		}

		/* fall through */
	case CHECKSUM_NONE:
		NAPI_GRO_CB(skb)->flush = 1;
		return NULL;
	}

	return tcp_gro_receive(head, skb);
}

H
Herbert Xu 已提交
817
static int tcp6_gro_complete(struct sk_buff *skb)
H
Herbert Xu 已提交
818
{
819
	const struct ipv6hdr *iph = ipv6_hdr(skb);
H
Herbert Xu 已提交
820 821 822 823 824 825 826 827 828
	struct tcphdr *th = tcp_hdr(skb);

	th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
				  &iph->saddr, &iph->daddr, 0);
	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;

	return tcp_gro_complete(skb);
}

829
static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
830
				 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
L
Linus Torvalds 已提交
831
{
832 833
	const struct tcphdr *th = tcp_hdr(skb);
	struct tcphdr *t1;
L
Linus Torvalds 已提交
834
	struct sk_buff *buff;
835
	struct flowi6 fl6;
E
Eric Dumazet 已提交
836
	struct net *net = dev_net(skb_dst(skb)->dev);
837
	struct sock *ctl_sk = net->ipv6.tcp_sk;
838
	unsigned int tot_len = sizeof(struct tcphdr);
E
Eric Dumazet 已提交
839
	struct dst_entry *dst;
840
	__be32 *topt;
L
Linus Torvalds 已提交
841

842 843
	if (ts)
		tot_len += TCPOLEN_TSTAMP_ALIGNED;
844 845 846 847 848 849
#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
850
			 GFP_ATOMIC);
851 852
	if (buff == NULL)
		return;
L
Linus Torvalds 已提交
853

854
	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
L
Linus Torvalds 已提交
855

856
	t1 = (struct tcphdr *) skb_push(buff, tot_len);
857
	skb_reset_transport_header(buff);
L
Linus Torvalds 已提交
858 859 860 861 862

	/* Swap the send and the receive. */
	memset(t1, 0, sizeof(*t1));
	t1->dest = th->source;
	t1->source = th->dest;
863
	t1->doff = tot_len / 4;
864 865 866 867 868
	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
869

870 871
	topt = (__be32 *)(t1 + 1);

872 873 874 875 876 877 878
	if (ts) {
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
		*topt++ = htonl(tcp_time_stamp);
		*topt++ = htonl(ts);
	}

879 880
#ifdef CONFIG_TCP_MD5SIG
	if (key) {
881 882 883
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
884 885
				    &ipv6_hdr(skb)->saddr,
				    &ipv6_hdr(skb)->daddr, t1);
886 887 888
	}
#endif

889
	memset(&fl6, 0, sizeof(fl6));
A
Alexey Dobriyan 已提交
890 891
	fl6.daddr = ipv6_hdr(skb)->saddr;
	fl6.saddr = ipv6_hdr(skb)->daddr;
L
Linus Torvalds 已提交
892

893 894 895
	buff->ip_summed = CHECKSUM_PARTIAL;
	buff->csum = 0;

896
	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
L
Linus Torvalds 已提交
897

898 899
	fl6.flowi6_proto = IPPROTO_TCP;
	fl6.flowi6_oif = inet6_iif(skb);
900 901
	fl6.fl6_dport = t1->dest;
	fl6.fl6_sport = t1->source;
902
	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
L
Linus Torvalds 已提交
903

904 905 906 907
	/* Pass a socket to ip6_dst_lookup either it is for RST
	 * Underlying function will use this to retrieve the network
	 * namespace
	 */
908
	dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
909 910
	if (!IS_ERR(dst)) {
		skb_dst_set(buff, dst);
911
		ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
912 913 914 915
		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
916 917 918 919 920
	}

	kfree_skb(buff);
}

921
static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
922
{
923
	const struct tcphdr *th = tcp_hdr(skb);
924
	u32 seq = 0, ack_seq = 0;
925
	struct tcp_md5sig_key *key = NULL;
926 927 928 929 930 931 932
#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
933

934
	if (th->rst)
L
Linus Torvalds 已提交
935 936
		return;

937 938
	if (!ipv6_unicast_destination(skb))
		return;
L
Linus Torvalds 已提交
939

940
#ifdef CONFIG_TCP_MD5SIG
941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966
	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),
					   &tcp_hashinfo, &ipv6h->daddr,
					   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;
	}
967 968
#endif

969 970 971 972 973
	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
974

975
	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
976 977 978 979 980 981 982 983

#ifdef CONFIG_TCP_MD5SIG
release_sk1:
	if (sk1) {
		rcu_read_unlock();
		sock_put(sk1);
	}
#endif
984
}
L
Linus Torvalds 已提交
985

986
static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
987
			    struct tcp_md5sig_key *key, u8 tclass)
988
{
989
	tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
L
Linus Torvalds 已提交
990 991 992 993
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
994
	struct inet_timewait_sock *tw = inet_twsk(sk);
995
	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
L
Linus Torvalds 已提交
996

997
	tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
998
			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
999 1000
			tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
			tw->tw_tclass);
L
Linus Torvalds 已提交
1001

1002
	inet_twsk_put(tw);
L
Linus Torvalds 已提交
1003 1004
}

1005 1006
static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
				  struct request_sock *req)
L
Linus Torvalds 已提交
1007
{
1008
	tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1009
			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
L
Linus Torvalds 已提交
1010 1011 1012 1013 1014
}


static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
{
1015
	struct request_sock *req, **prev;
1016
	const struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1017 1018 1019
	struct sock *nsk;

	/* Find possible connection requests. */
1020
	req = inet6_csk_search_req(sk, &prev, th->source,
1021 1022
				   &ipv6_hdr(skb)->saddr,
				   &ipv6_hdr(skb)->daddr, inet6_iif(skb));
L
Linus Torvalds 已提交
1023 1024 1025
	if (req)
		return tcp_check_req(sk, skb, req, prev);

1026
	nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1027 1028
			&ipv6_hdr(skb)->saddr, th->source,
			&ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
1029 1030 1031 1032 1033 1034

	if (nsk) {
		if (nsk->sk_state != TCP_TIME_WAIT) {
			bh_lock_sock(nsk);
			return nsk;
		}
1035
		inet_twsk_put(inet_twsk(nsk));
L
Linus Torvalds 已提交
1036 1037 1038
		return NULL;
	}

1039
#ifdef CONFIG_SYN_COOKIES
1040
	if (!th->syn)
1041
		sk = cookie_v6_check(sk, skb);
L
Linus Torvalds 已提交
1042 1043 1044 1045 1046 1047 1048 1049 1050
#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)
{
1051
	struct tcp_extend_values tmp_ext;
1052
	struct tcp_options_received tmp_opt;
1053
	const u8 *hash_location;
1054
	struct request_sock *req;
1055
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
1056 1057
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_sock *tp = tcp_sk(sk);
1058
	__u32 isn = TCP_SKB_CB(skb)->when;
1059
	struct dst_entry *dst = NULL;
1060
	int want_cookie = 0;
L
Linus Torvalds 已提交
1061 1062 1063 1064 1065

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

	if (!ipv6_unicast_destination(skb))
1066
		goto drop;
L
Linus Torvalds 已提交
1067

1068
	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1069 1070 1071
		want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
		if (!want_cookie)
			goto drop;
L
Linus Torvalds 已提交
1072 1073
	}

1074
	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
L
Linus Torvalds 已提交
1075 1076
		goto drop;

1077
	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
L
Linus Torvalds 已提交
1078 1079 1080
	if (req == NULL)
		goto drop;

1081 1082 1083 1084
#ifdef CONFIG_TCP_MD5SIG
	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
#endif

L
Linus Torvalds 已提交
1085 1086 1087
	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;
1088
	tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104

	if (tmp_opt.cookie_plus > 0 &&
	    tmp_opt.saw_tstamp &&
	    !tp->rx_opt.cookie_out_never &&
	    (sysctl_tcp_cookie_size > 0 ||
	     (tp->cookie_values != NULL &&
	      tp->cookie_values->cookie_desired > 0))) {
		u8 *c;
		u32 *d;
		u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
		int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;

		if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
			goto drop_and_free;

		/* Secret recipe starts with IP addresses */
1105
		d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1106 1107 1108 1109
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;
1110
		d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1111 1112 1113 1114 1115 1116 1117 1118 1119
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;

		/* plus variable length Initiator Cookie */
		c = (u8 *)mess;
		while (l-- > 0)
			*c++ ^= *hash_location++;
L
Linus Torvalds 已提交
1120

1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131
		want_cookie = 0;	/* not our kind of cookie */
		tmp_ext.cookie_out_never = 0; /* false */
		tmp_ext.cookie_plus = tmp_opt.cookie_plus;
	} else if (!tp->rx_opt.cookie_in_always) {
		/* redundant indications, but ensure initialization. */
		tmp_ext.cookie_out_never = 1; /* true */
		tmp_ext.cookie_plus = 0;
	} else {
		goto drop_and_free;
	}
	tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
L
Linus Torvalds 已提交
1132

1133
	if (want_cookie && !tmp_opt.saw_tstamp)
1134 1135
		tcp_clear_options(&tmp_opt);

L
Linus Torvalds 已提交
1136 1137 1138
	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
	tcp_openreq_init(req, &tmp_opt, skb);

1139
	treq = inet6_rsk(req);
A
Alexey Dobriyan 已提交
1140 1141
	treq->rmt_addr = ipv6_hdr(skb)->saddr;
	treq->loc_addr = ipv6_hdr(skb)->daddr;
1142
	if (!want_cookie || tmp_opt.tstamp_ok)
1143 1144
		TCP_ECN_create_request(req, tcp_hdr(skb));

1145 1146 1147 1148 1149 1150 1151
	treq->iif = sk->sk_bound_dev_if;

	/* So that link locals have meaning */
	if (!sk->sk_bound_dev_if &&
	    ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
		treq->iif = inet6_iif(skb);

1152
	if (!isn) {
1153 1154
		struct inet_peer *peer = NULL;

1155 1156 1157 1158 1159 1160
		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);
			treq->pktopts = skb;
		}
1161 1162

		if (want_cookie) {
1163 1164
			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
			req->cookie_ts = tmp_opt.tstamp_ok;
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180
			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 &&
		    (dst = inet6_csk_route_req(sk, req)) != NULL &&
		    (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1181
		    ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206
				    &treq->rmt_addr)) {
			inet_peer_refcheck(peer);
			if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
			    (s32)(peer->tcp_ts - req->ts_recent) >
							TCP_PAWS_WINDOW) {
				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)) &&
			 (!peer || !peer->tcp_ts_stamp) &&
			 (!dst || !dst_metric(dst, RTAX_RTT))) {
			/* 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",
				       &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
			goto drop_and_release;
1207
		}
1208 1209

		isn = tcp_v6_init_sequence(skb);
1210
	}
1211
have_isn:
1212
	tcp_rsk(req)->snt_isn = isn;
1213
	tcp_rsk(req)->snt_synack = tcp_time_stamp;
L
Linus Torvalds 已提交
1214

1215 1216
	security_inet_conn_request(sk, skb, req);

1217 1218 1219
	if (tcp_v6_send_synack(sk, req,
			       (struct request_values *)&tmp_ext) ||
	    want_cookie)
1220
		goto drop_and_free;
L
Linus Torvalds 已提交
1221

1222 1223
	inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
	return 0;
L
Linus Torvalds 已提交
1224

1225 1226
drop_and_release:
	dst_release(dst);
1227 1228
drop_and_free:
	reqsk_free(req);
L
Linus Torvalds 已提交
1229 1230 1231 1232 1233
drop:
	return 0; /* don't send reset */
}

static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1234
					  struct request_sock *req,
L
Linus Torvalds 已提交
1235 1236
					  struct dst_entry *dst)
{
1237
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
1238 1239 1240 1241 1242 1243
	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
	struct tcp6_sock *newtcp6sk;
	struct inet_sock *newinet;
	struct tcp_sock *newtp;
	struct sock *newsk;
	struct ipv6_txoptions *opt;
1244 1245 1246
#ifdef CONFIG_TCP_MD5SIG
	struct tcp_md5sig_key *key;
#endif
L
Linus Torvalds 已提交
1247 1248 1249 1250 1251 1252 1253 1254

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

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

1255
		if (newsk == NULL)
L
Linus Torvalds 已提交
1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
			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));

E
Eric Dumazet 已提交
1267
		ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
L
Linus Torvalds 已提交
1268

E
Eric Dumazet 已提交
1269
		ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
L
Linus Torvalds 已提交
1270

A
Alexey Dobriyan 已提交
1271
		newnp->rcv_saddr = newnp->saddr;
L
Linus Torvalds 已提交
1272

1273
		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
L
Linus Torvalds 已提交
1274
		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1275 1276 1277 1278
#ifdef CONFIG_TCP_MD5SIG
		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif

1279 1280
		newnp->ipv6_ac_list = NULL;
		newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1281 1282
		newnp->pktoptions  = NULL;
		newnp->opt	   = NULL;
1283
		newnp->mcast_oif   = inet6_iif(skb);
1284
		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1285
		newnp->rcv_tclass  = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1286

1287 1288 1289 1290
		/*
		 * 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
1291 1292 1293
		 */

		/* It is tricky place. Until this moment IPv4 tcp
1294
		   worked with IPv6 icsk.icsk_af_ops.
L
Linus Torvalds 已提交
1295 1296
		   Sync it now.
		 */
1297
		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
L
Linus Torvalds 已提交
1298 1299 1300 1301

		return newsk;
	}

1302
	treq = inet6_rsk(req);
L
Linus Torvalds 已提交
1303 1304 1305 1306 1307
	opt = np->opt;

	if (sk_acceptq_is_full(sk))
		goto out_overflow;

1308 1309 1310
	if (!dst) {
		dst = inet6_csk_route_req(sk, req);
		if (!dst)
L
Linus Torvalds 已提交
1311
			goto out;
1312
	}
L
Linus Torvalds 已提交
1313 1314 1315

	newsk = tcp_create_openreq_child(sk, req, skb);
	if (newsk == NULL)
1316
		goto out_nonewsk;
L
Linus Torvalds 已提交
1317

1318 1319 1320 1321 1322
	/*
	 * 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
1323

1324
	newsk->sk_gso_type = SKB_GSO_TCPV6;
1325
	__ip6_dst_store(newsk, dst, NULL, NULL);
L
Linus Torvalds 已提交
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335

	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));

A
Alexey Dobriyan 已提交
1336 1337 1338
	newnp->daddr = treq->rmt_addr;
	newnp->saddr = treq->loc_addr;
	newnp->rcv_saddr = treq->loc_addr;
1339
	newsk->sk_bound_dev_if = treq->iif;
L
Linus Torvalds 已提交
1340

1341
	/* Now IPv6 options...
L
Linus Torvalds 已提交
1342 1343 1344

	   First: no IPv4 options.
	 */
1345
	newinet->inet_opt = NULL;
1346
	newnp->ipv6_ac_list = NULL;
1347
	newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1348 1349 1350 1351 1352 1353

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

	/* Clone pktoptions received with SYN */
	newnp->pktoptions = NULL;
1354 1355
	if (treq->pktopts != NULL) {
		newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1356
		consume_skb(treq->pktopts);
1357
		treq->pktopts = NULL;
L
Linus Torvalds 已提交
1358 1359 1360 1361
		if (newnp->pktoptions)
			skb_set_owner_r(newnp->pktoptions, newsk);
	}
	newnp->opt	  = NULL;
1362
	newnp->mcast_oif  = inet6_iif(skb);
1363
	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1364
	newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377

	/* 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.
	 */
	if (opt) {
		newnp->opt = ipv6_dup_options(newsk, opt);
		if (opt != np->opt)
			sock_kfree_s(sk, opt, opt->tot_len);
	}

1378
	inet_csk(newsk)->icsk_ext_hdr_len = 0;
L
Linus Torvalds 已提交
1379
	if (newnp->opt)
1380 1381
		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
						     newnp->opt->opt_flen);
L
Linus Torvalds 已提交
1382

J
John Heffner 已提交
1383
	tcp_mtup_init(newsk);
L
Linus Torvalds 已提交
1384
	tcp_sync_mss(newsk, dst_mtu(dst));
1385
	newtp->advmss = dst_metric_advmss(dst);
1386 1387 1388 1389
	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
1390
	tcp_initialize_rcv_mss(newsk);
1391 1392 1393 1394
	if (tcp_rsk(req)->snt_synack)
		tcp_valid_rtt_meas(newsk,
		    tcp_time_stamp - tcp_rsk(req)->snt_synack);
	newtp->total_retrans = req->retrans;
L
Linus Torvalds 已提交
1395

E
Eric Dumazet 已提交
1396 1397
	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
L
Linus Torvalds 已提交
1398

1399 1400 1401 1402 1403 1404 1405 1406
#ifdef CONFIG_TCP_MD5SIG
	/* Copy over the MD5 key from the original socket */
	if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
		/* 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.
		 */
E
Eric Dumazet 已提交
1407 1408
		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
			       AF_INET6, key->key, key->keylen, GFP_ATOMIC);
1409 1410 1411
	}
#endif

1412 1413 1414 1415
	if (__inet_inherit_port(sk, newsk) < 0) {
		sock_put(newsk);
		goto out;
	}
1416
	__inet6_hash(newsk, NULL);
L
Linus Torvalds 已提交
1417 1418 1419 1420

	return newsk;

out_overflow:
1421
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1422
out_nonewsk:
L
Linus Torvalds 已提交
1423 1424 1425
	if (opt && opt != np->opt)
		sock_kfree_s(sk, opt, opt->tot_len);
	dst_release(dst);
1426 1427
out:
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
L
Linus Torvalds 已提交
1428 1429 1430
	return NULL;
}

1431
static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
L
Linus Torvalds 已提交
1432
{
1433
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
H
Herbert Xu 已提交
1434
		if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1435
				  &ipv6_hdr(skb)->daddr, skb->csum)) {
1436
			skb->ip_summed = CHECKSUM_UNNECESSARY;
L
Linus Torvalds 已提交
1437
			return 0;
1438
		}
L
Linus Torvalds 已提交
1439
	}
1440

H
Herbert Xu 已提交
1441
	skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1442 1443
					      &ipv6_hdr(skb)->saddr,
					      &ipv6_hdr(skb)->daddr, 0));
1444

L
Linus Torvalds 已提交
1445
	if (skb->len <= 76) {
1446
		return __skb_checksum_complete(skb);
L
Linus Torvalds 已提交
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
	}
	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);

1476 1477 1478 1479 1480
#ifdef CONFIG_TCP_MD5SIG
	if (tcp_v6_inbound_md5_hash (sk, skb))
		goto discard;
#endif

1481
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499
		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.
1500
					       --ANK (980728)
L
Linus Torvalds 已提交
1501 1502 1503 1504 1505
	 */
	if (np->rxopt.all)
		opt_skb = skb_clone(skb, GFP_ATOMIC);

	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1506
		sock_rps_save_rxhash(sk, skb);
1507
		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1508 1509 1510 1511 1512 1513
			goto reset;
		if (opt_skb)
			goto ipv6_pktoptions;
		return 0;
	}

1514
	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
L
Linus Torvalds 已提交
1515 1516
		goto csum_err;

1517
	if (sk->sk_state == TCP_LISTEN) {
L
Linus Torvalds 已提交
1518 1519 1520 1521 1522 1523 1524 1525 1526
		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..
		 */
1527
		if(nsk != sk) {
1528
			sock_rps_save_rxhash(nsk, skb);
L
Linus Torvalds 已提交
1529 1530 1531 1532 1533 1534
			if (tcp_child_process(sk, nsk, skb))
				goto reset;
			if (opt_skb)
				__kfree_skb(opt_skb);
			return 0;
		}
1535
	} else
1536
		sock_rps_save_rxhash(sk, skb);
L
Linus Torvalds 已提交
1537

1538
	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1539 1540 1541 1542 1543 1544
		goto reset;
	if (opt_skb)
		goto ipv6_pktoptions;
	return 0;

reset:
1545
	tcp_v6_send_reset(sk, skb);
L
Linus Torvalds 已提交
1546 1547 1548 1549 1550 1551
discard:
	if (opt_skb)
		__kfree_skb(opt_skb);
	kfree_skb(skb);
	return 0;
csum_err:
1552
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
	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))) {
1567
		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1568
			np->mcast_oif = inet6_iif(opt_skb);
1569
		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1570
			np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1571 1572
		if (np->rxopt.bits.rxtclass)
			np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1573 1574 1575 1576 1577 1578 1579 1580 1581
		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);
		}
	}

1582
	kfree_skb(opt_skb);
L
Linus Torvalds 已提交
1583 1584 1585
	return 0;
}

1586
static int tcp_v6_rcv(struct sk_buff *skb)
L
Linus Torvalds 已提交
1587
{
1588
	const struct tcphdr *th;
1589
	const struct ipv6hdr *hdr;
L
Linus Torvalds 已提交
1590 1591
	struct sock *sk;
	int ret;
1592
	struct net *net = dev_net(skb->dev);
L
Linus Torvalds 已提交
1593 1594 1595 1596 1597 1598 1599

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

	/*
	 *	Count it even if it's bad.
	 */
1600
	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
L
Linus Torvalds 已提交
1601 1602 1603 1604

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

1605
	th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1606 1607 1608 1609 1610 1611

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

1612
	if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
L
Linus Torvalds 已提交
1613 1614
		goto bad_packet;

1615
	th = tcp_hdr(skb);
1616
	hdr = ipv6_hdr(skb);
L
Linus Torvalds 已提交
1617 1618 1619 1620 1621
	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;
1622
	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
L
Linus Torvalds 已提交
1623 1624
	TCP_SKB_CB(skb)->sacked = 0;

1625
	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
L
Linus Torvalds 已提交
1626 1627 1628 1629 1630 1631 1632
	if (!sk)
		goto no_tcp_socket;

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

1633 1634 1635 1636 1637
	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
1638 1639 1640
	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_and_relse;

1641
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1642 1643 1644 1645
		goto discard_and_relse;

	skb->dev = NULL;

1646
	bh_lock_sock_nested(sk);
L
Linus Torvalds 已提交
1647 1648
	ret = 0;
	if (!sock_owned_by_user(sk)) {
C
Chris Leech 已提交
1649
#ifdef CONFIG_NET_DMA
1650
		struct tcp_sock *tp = tcp_sk(sk);
1651
		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1652
			tp->ucopy.dma_chan = net_dma_find_channel();
1653 1654 1655
		if (tp->ucopy.dma_chan)
			ret = tcp_v6_do_rcv(sk, skb);
		else
C
Chris Leech 已提交
1656 1657 1658 1659 1660
#endif
		{
			if (!tcp_prequeue(sk, skb))
				ret = tcp_v6_do_rcv(sk, skb);
		}
1661 1662
	} else if (unlikely(sk_add_backlog(sk, skb,
					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
Z
Zhu Yi 已提交
1663
		bh_unlock_sock(sk);
1664
		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
Z
Zhu Yi 已提交
1665 1666
		goto discard_and_relse;
	}
L
Linus Torvalds 已提交
1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677
	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)) {
bad_packet:
1678
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1679
	} else {
1680
		tcp_v6_send_reset(NULL, skb);
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697
	}

discard_it:

	/*
	 *	Discard frame
	 */

	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)) {
1698
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1699 1700 1701 1702
		goto discard_it;
	}

	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1703
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1704
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1705 1706 1707
		goto discard_it;
	}

1708
	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
L
Linus Torvalds 已提交
1709 1710 1711 1712
	case TCP_TW_SYN:
	{
		struct sock *sk2;

1713
		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1714
					    &ipv6_hdr(skb)->daddr,
1715
					    ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
1716
		if (sk2 != NULL) {
1717 1718 1719
			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
1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734
			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;
}

1735 1736
static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
{
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748
	struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct inet_peer *peer;

	if (!rt ||
	    !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
		peer = inet_getpeer_v6(&np->daddr, 1);
		*release_it = true;
	} else {
		if (!rt->rt6i_peer)
			rt6_bind_peer(rt, 1);
		peer = rt->rt6i_peer;
1749
		*release_it = false;
1750 1751 1752
	}

	return peer;
1753 1754 1755
}

static void *tcp_v6_tw_get_peer(struct sock *sk)
L
Linus Torvalds 已提交
1756
{
1757 1758
	const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
	const struct inet_timewait_sock *tw = inet_twsk(sk);
1759 1760 1761 1762

	if (tw->tw_family == AF_INET)
		return tcp_v4_tw_get_peer(sk);

1763
	return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
L
Linus Torvalds 已提交
1764 1765
}

1766 1767 1768 1769 1770 1771 1772
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,
	.twsk_getpeer	= tcp_v6_tw_get_peer,
};

1773
static const struct inet_connection_sock_af_ops ipv6_specific = {
1774 1775 1776 1777 1778
	.queue_xmit	   = inet6_csk_xmit,
	.send_check	   = tcp_v6_send_check,
	.rebuild_header	   = inet6_sk_rebuild_header,
	.conn_request	   = tcp_v6_conn_request,
	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
1779
	.get_peer	   = tcp_v6_get_peer,
1780 1781 1782 1783 1784
	.net_header_len	   = sizeof(struct ipv6hdr),
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1785
	.bind_conflict	   = inet6_csk_bind_conflict,
1786
#ifdef CONFIG_COMPAT
1787 1788
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1789
#endif
L
Linus Torvalds 已提交
1790 1791
};

1792
#ifdef CONFIG_TCP_MD5SIG
1793
static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1794
	.md5_lookup	=	tcp_v6_md5_lookup,
1795
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
1796 1797
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1798
#endif
1799

L
Linus Torvalds 已提交
1800 1801 1802 1803
/*
 *	TCP over IPv4 via INET6 API
 */

1804
static const struct inet_connection_sock_af_ops ipv6_mapped = {
1805 1806 1807 1808 1809
	.queue_xmit	   = ip_queue_xmit,
	.send_check	   = tcp_v4_send_check,
	.rebuild_header	   = inet_sk_rebuild_header,
	.conn_request	   = tcp_v6_conn_request,
	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
1810
	.get_peer	   = tcp_v4_get_peer,
1811 1812 1813 1814 1815
	.net_header_len	   = sizeof(struct iphdr),
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1816
	.bind_conflict	   = inet6_csk_bind_conflict,
1817
#ifdef CONFIG_COMPAT
1818 1819
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1820
#endif
L
Linus Torvalds 已提交
1821 1822
};

1823
#ifdef CONFIG_TCP_MD5SIG
1824
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1825
	.md5_lookup	=	tcp_v4_md5_lookup,
1826
	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
1827 1828
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1829
#endif
1830

L
Linus Torvalds 已提交
1831 1832 1833 1834 1835
/* 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)
{
1836
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1837

1838
	tcp_init_sock(sk);
L
Linus Torvalds 已提交
1839

1840
	icsk->icsk_af_ops = &ipv6_specific;
L
Linus Torvalds 已提交
1841

1842
#ifdef CONFIG_TCP_MD5SIG
1843
	tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1844 1845
#endif

L
Linus Torvalds 已提交
1846 1847 1848
	return 0;
}

1849
static void tcp_v6_destroy_sock(struct sock *sk)
L
Linus Torvalds 已提交
1850 1851
{
	tcp_v4_destroy_sock(sk);
1852
	inet6_destroy_sock(sk);
L
Linus Torvalds 已提交
1853 1854
}

1855
#ifdef CONFIG_PROC_FS
L
Linus Torvalds 已提交
1856
/* Proc filesystem TCPv6 sock list dumping. */
1857
static void get_openreq6(struct seq_file *seq,
1858
			 const struct sock *sk, struct request_sock *req, int i, int uid)
L
Linus Torvalds 已提交
1859 1860
{
	int ttd = req->expires - jiffies;
1861 1862
	const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
	const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
L
Linus Torvalds 已提交
1863 1864 1865 1866 1867 1868

	if (ttd < 0)
		ttd = 0;

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
D
Dan Rosenberg 已提交
1869
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1870 1871 1872
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3],
1873
		   ntohs(inet_rsk(req)->loc_port),
L
Linus Torvalds 已提交
1874 1875
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3],
1876
		   ntohs(inet_rsk(req)->rmt_port),
L
Linus Torvalds 已提交
1877 1878
		   TCP_SYN_RECV,
		   0,0, /* could print option size, but that is af dependent. */
1879 1880
		   1,   /* timers active (only the expire timer) */
		   jiffies_to_clock_t(ttd),
L
Linus Torvalds 已提交
1881 1882
		   req->retrans,
		   uid,
1883
		   0,  /* non standard timer */
L
Linus Torvalds 已提交
1884 1885 1886 1887 1888 1889
		   0, /* open_requests have no inode */
		   0, req);
}

static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
{
1890
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1891 1892 1893
	__u16 destp, srcp;
	int timer_active;
	unsigned long timer_expires;
1894 1895
	const struct inet_sock *inet = inet_sk(sp);
	const struct tcp_sock *tp = tcp_sk(sp);
1896
	const struct inet_connection_sock *icsk = inet_csk(sp);
1897
	const struct ipv6_pinfo *np = inet6_sk(sp);
L
Linus Torvalds 已提交
1898 1899 1900

	dest  = &np->daddr;
	src   = &np->rcv_saddr;
E
Eric Dumazet 已提交
1901 1902
	destp = ntohs(inet->inet_dport);
	srcp  = ntohs(inet->inet_sport);
1903 1904

	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
L
Linus Torvalds 已提交
1905
		timer_active	= 1;
1906 1907
		timer_expires	= icsk->icsk_timeout;
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
L
Linus Torvalds 已提交
1908
		timer_active	= 4;
1909
		timer_expires	= icsk->icsk_timeout;
L
Linus Torvalds 已提交
1910 1911 1912 1913 1914 1915 1916 1917 1918 1919
	} 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 "
D
Dan Rosenberg 已提交
1920
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
L
Linus Torvalds 已提交
1921 1922 1923 1924 1925
		   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,
1926
		   sp->sk_state,
1927 1928
		   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
1929 1930
		   timer_active,
		   jiffies_to_clock_t(timer_expires - jiffies),
1931
		   icsk->icsk_retransmits,
L
Linus Torvalds 已提交
1932
		   sock_i_uid(sp),
1933
		   icsk->icsk_probes_out,
L
Linus Torvalds 已提交
1934 1935
		   sock_i_ino(sp),
		   atomic_read(&sp->sk_refcnt), sp,
1936 1937
		   jiffies_to_clock_t(icsk->icsk_rto),
		   jiffies_to_clock_t(icsk->icsk_ack.ato),
1938
		   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
I
Ilpo Järvinen 已提交
1939 1940
		   tp->snd_cwnd,
		   tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
L
Linus Torvalds 已提交
1941 1942 1943
		   );
}

1944
static void get_timewait6_sock(struct seq_file *seq,
1945
			       struct inet_timewait_sock *tw, int i)
L
Linus Torvalds 已提交
1946
{
1947
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1948
	__u16 destp, srcp;
1949
	const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
L
Linus Torvalds 已提交
1950 1951 1952 1953 1954
	int ttd = tw->tw_ttd - jiffies;

	if (ttd < 0)
		ttd = 0;

1955 1956
	dest = &tw6->tw_v6_daddr;
	src  = &tw6->tw_v6_rcv_saddr;
L
Linus Torvalds 已提交
1957 1958 1959 1960 1961
	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
1962
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
		   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,
		   3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
		   atomic_read(&tw->tw_refcnt), tw);
}

static int tcp6_seq_show(struct seq_file *seq, void *v)
{
	struct tcp_iter_state *st;

	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:
		get_tcp6_sock(seq, v, st->num);
		break;
	case TCP_SEQ_STATE_OPENREQ:
		get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
		break;
	case TCP_SEQ_STATE_TIME_WAIT:
		get_timewait6_sock(seq, v, st->num);
		break;
	}
out:
	return 0;
}

2004 2005 2006 2007 2008 2009 2010 2011
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
2012 2013 2014
static struct tcp_seq_afinfo tcp6_seq_afinfo = {
	.name		= "tcp6",
	.family		= AF_INET6,
2015
	.seq_fops	= &tcp6_afinfo_seq_fops,
2016 2017 2018
	.seq_ops	= {
		.show		= tcp6_seq_show,
	},
L
Linus Torvalds 已提交
2019 2020
};

2021
int __net_init tcp6_proc_init(struct net *net)
L
Linus Torvalds 已提交
2022
{
2023
	return tcp_proc_register(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
2024 2025
}

2026
void tcp6_proc_exit(struct net *net)
L
Linus Torvalds 已提交
2027
{
2028
	tcp_proc_unregister(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
2029 2030 2031 2032 2033 2034 2035 2036 2037
}
#endif

struct proto tcpv6_prot = {
	.name			= "TCPv6",
	.owner			= THIS_MODULE,
	.close			= tcp_close,
	.connect		= tcp_v6_connect,
	.disconnect		= tcp_disconnect,
2038
	.accept			= inet_csk_accept,
L
Linus Torvalds 已提交
2039 2040 2041 2042 2043 2044 2045
	.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,
2046 2047
	.sendmsg		= tcp_sendmsg,
	.sendpage		= tcp_sendpage,
L
Linus Torvalds 已提交
2048 2049
	.backlog_rcv		= tcp_v6_do_rcv,
	.hash			= tcp_v6_hash,
2050 2051
	.unhash			= inet_unhash,
	.get_port		= inet_csk_get_port,
L
Linus Torvalds 已提交
2052 2053 2054 2055
	.enter_memory_pressure	= tcp_enter_memory_pressure,
	.sockets_allocated	= &tcp_sockets_allocated,
	.memory_allocated	= &tcp_memory_allocated,
	.memory_pressure	= &tcp_memory_pressure,
2056
	.orphan_count		= &tcp_orphan_count,
L
Linus Torvalds 已提交
2057 2058 2059 2060
	.sysctl_wmem		= sysctl_tcp_wmem,
	.sysctl_rmem		= sysctl_tcp_rmem,
	.max_header		= MAX_TCP_HEADER,
	.obj_size		= sizeof(struct tcp6_sock),
2061
	.slab_flags		= SLAB_DESTROY_BY_RCU,
2062
	.twsk_prot		= &tcp6_timewait_sock_ops,
2063
	.rsk_prot		= &tcp6_request_sock_ops,
2064
	.h.hashinfo		= &tcp_hashinfo,
2065
	.no_autobind		= true,
2066 2067 2068 2069
#ifdef CONFIG_COMPAT
	.compat_setsockopt	= compat_tcp_setsockopt,
	.compat_getsockopt	= compat_tcp_getsockopt,
#endif
G
Glauber Costa 已提交
2070 2071 2072
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
	.proto_cgroup		= tcp_proto_cgroup,
#endif
L
Linus Torvalds 已提交
2073 2074
};

2075
static const struct inet6_protocol tcpv6_protocol = {
L
Linus Torvalds 已提交
2076 2077
	.handler	=	tcp_v6_rcv,
	.err_handler	=	tcp_v6_err,
2078
	.gso_send_check	=	tcp_v6_gso_send_check,
H
Herbert Xu 已提交
2079
	.gso_segment	=	tcp_tso_segment,
H
Herbert Xu 已提交
2080 2081
	.gro_receive	=	tcp6_gro_receive,
	.gro_complete	=	tcp6_gro_complete,
L
Linus Torvalds 已提交
2082 2083 2084 2085 2086 2087 2088 2089 2090
	.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,
2091 2092
	.flags		=	INET_PROTOSW_PERMANENT |
				INET_PROTOSW_ICSK,
L
Linus Torvalds 已提交
2093 2094
};

2095
static int __net_init tcpv6_net_init(struct net *net)
2096
{
2097 2098
	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
				    SOCK_RAW, IPPROTO_TCP, net);
2099 2100
}

2101
static void __net_exit tcpv6_net_exit(struct net *net)
2102
{
2103
	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
E
Eric W. Biederman 已提交
2104 2105
}

2106
static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
E
Eric W. Biederman 已提交
2107 2108
{
	inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2109 2110 2111
}

static struct pernet_operations tcpv6_net_ops = {
E
Eric W. Biederman 已提交
2112 2113 2114
	.init	    = tcpv6_net_init,
	.exit	    = tcpv6_net_exit,
	.exit_batch = tcpv6_net_exit_batch,
2115 2116
};

2117
int __init tcpv6_init(void)
L
Linus Torvalds 已提交
2118
{
2119 2120 2121 2122 2123 2124
	int ret;

	ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
	if (ret)
		goto out;

L
Linus Torvalds 已提交
2125
	/* register inet6 protocol */
2126 2127 2128 2129
	ret = inet6_register_protosw(&tcpv6_protosw);
	if (ret)
		goto out_tcpv6_protocol;

2130
	ret = register_pernet_subsys(&tcpv6_net_ops);
2131 2132 2133 2134
	if (ret)
		goto out_tcpv6_protosw;
out:
	return ret;
2135

2136 2137 2138 2139 2140 2141 2142
out_tcpv6_protocol:
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
out_tcpv6_protosw:
	inet6_unregister_protosw(&tcpv6_protosw);
	goto out;
}

2143
void tcpv6_exit(void)
2144
{
2145
	unregister_pernet_subsys(&tcpv6_net_ops);
2146 2147
	inet6_unregister_protosw(&tcpv6_protosw);
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
L
Linus Torvalds 已提交
2148
}