tcp_ipv6.c 51.4 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 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 &&
	    !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 &&
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	    ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr))
		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,
							     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;
}

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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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	}

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	if (type == ICMPV6_PKT_TOOBIG) {
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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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		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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			      struct request_values *rvp,
			      u16 queue_mapping)
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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;
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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, rvp, NULL);
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	if (skb) {
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		__tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
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		fl6->daddr = treq->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,
			     struct request_values *rvp)
{
486
	struct flowi6 fl6;
487
	int res;
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	res = tcp_v6_send_synack(sk, NULL, &fl6, req, rvp, 0);
	if (!res)
		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
	return res;
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}

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static void tcp_v6_reqsk_destructor(struct request_sock *req)
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{
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	kfree_skb(inet6_rsk(req)->pktopts);
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}

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#ifdef CONFIG_TCP_MD5SIG
static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
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						   const struct in6_addr *addr)
503
{
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	return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534
}

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
535
		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
E
Eric Dumazet 已提交
536 537 538 539
			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);
540 541 542 543 544
	}

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

E
Eric Dumazet 已提交
545 546 547
	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);
548

E
Eric Dumazet 已提交
549 550
	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
			      AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
551 552
}

553
static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
554 555
					const struct in6_addr *daddr,
					const struct in6_addr *saddr, int nbytes)
556 557
{
	struct tcp6_pseudohdr *bp;
558
	struct scatterlist sg;
559

560 561
	bp = &hp->md5_blk.ip6;
	/* 1. TCP pseudo-header (RFC2460) */
A
Alexey Dobriyan 已提交
562 563
	bp->saddr = *saddr;
	bp->daddr = *daddr;
564
	bp->protocol = cpu_to_be32(IPPROTO_TCP);
A
Adam Langley 已提交
565
	bp->len = cpu_to_be32(nbytes);
566

567 568 569
	sg_init_one(&sg, bp, sizeof(*bp));
	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
}
570

571
static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
572
			       const struct in6_addr *daddr, struct in6_addr *saddr,
E
Eric Dumazet 已提交
573
			       const struct tcphdr *th)
574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591
{
	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))
592 593 594 595
		goto clear_hash;

	tcp_put_md5sig_pool();
	return 0;
596

597 598 599 600
clear_hash:
	tcp_put_md5sig_pool();
clear_hash_noput:
	memset(md5_hash, 0, 16);
601
	return 1;
602 603
}

604
static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
E
Eric Dumazet 已提交
605 606 607
			       const struct sock *sk,
			       const struct request_sock *req,
			       const struct sk_buff *skb)
608
{
609
	const struct in6_addr *saddr, *daddr;
610 611
	struct tcp_md5sig_pool *hp;
	struct hash_desc *desc;
E
Eric Dumazet 已提交
612
	const struct tcphdr *th = tcp_hdr(skb);
613 614 615 616

	if (sk) {
		saddr = &inet6_sk(sk)->saddr;
		daddr = &inet6_sk(sk)->daddr;
617
	} else if (req) {
618 619
		saddr = &inet6_rsk(req)->loc_addr;
		daddr = &inet6_rsk(req)->rmt_addr;
620
	} else {
621
		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
622 623
		saddr = &ip6h->saddr;
		daddr = &ip6h->daddr;
624
	}
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652

	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;
653 654
}

E
Eric Dumazet 已提交
655
static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
656
{
657
	const __u8 *hash_location = NULL;
658
	struct tcp_md5sig_key *hash_expected;
659
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
E
Eric Dumazet 已提交
660
	const struct tcphdr *th = tcp_hdr(skb);
661 662 663 664
	int genhash;
	u8 newhash[16];

	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
665
	hash_location = tcp_parse_md5sig_option(th);
666

667 668 669 670 671 672
	/* 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);
673 674 675
		return 1;
	}

676 677
	if (!hash_expected && hash_location) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
678 679 680 681
		return 1;
	}

	/* check the signature */
682 683 684 685
	genhash = tcp_v6_md5_hash_skb(newhash,
				      hash_expected,
				      NULL, NULL, skb);

686
	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
687 688 689 690
		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));
691 692 693 694 695 696
		return 1;
	}
	return 0;
}
#endif

697
struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
L
Linus Torvalds 已提交
698
	.family		=	AF_INET6,
699
	.obj_size	=	sizeof(struct tcp6_request_sock),
700
	.rtx_syn_ack	=	tcp_v6_rtx_synack,
701 702
	.send_ack	=	tcp_v6_reqsk_send_ack,
	.destructor	=	tcp_v6_reqsk_destructor,
703 704
	.send_reset	=	tcp_v6_send_reset,
	.syn_ack_timeout = 	tcp_syn_ack_timeout,
L
Linus Torvalds 已提交
705 706
};

707
#ifdef CONFIG_TCP_MD5SIG
708
static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
709
	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
710
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
711
};
712
#endif
713

714
static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
715
				 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
L
Linus Torvalds 已提交
716
{
717 718
	const struct tcphdr *th = tcp_hdr(skb);
	struct tcphdr *t1;
L
Linus Torvalds 已提交
719
	struct sk_buff *buff;
720
	struct flowi6 fl6;
E
Eric Dumazet 已提交
721
	struct net *net = dev_net(skb_dst(skb)->dev);
722
	struct sock *ctl_sk = net->ipv6.tcp_sk;
723
	unsigned int tot_len = sizeof(struct tcphdr);
E
Eric Dumazet 已提交
724
	struct dst_entry *dst;
725
	__be32 *topt;
L
Linus Torvalds 已提交
726

727 728
	if (ts)
		tot_len += TCPOLEN_TSTAMP_ALIGNED;
729 730 731 732 733 734
#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
735
			 GFP_ATOMIC);
736 737
	if (buff == NULL)
		return;
L
Linus Torvalds 已提交
738

739
	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
L
Linus Torvalds 已提交
740

741
	t1 = (struct tcphdr *) skb_push(buff, tot_len);
742
	skb_reset_transport_header(buff);
L
Linus Torvalds 已提交
743 744 745 746 747

	/* Swap the send and the receive. */
	memset(t1, 0, sizeof(*t1));
	t1->dest = th->source;
	t1->source = th->dest;
748
	t1->doff = tot_len / 4;
749 750 751 752 753
	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
754

755 756
	topt = (__be32 *)(t1 + 1);

757 758 759 760 761 762 763
	if (ts) {
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
		*topt++ = htonl(tcp_time_stamp);
		*topt++ = htonl(ts);
	}

764 765
#ifdef CONFIG_TCP_MD5SIG
	if (key) {
766 767 768
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
769 770
				    &ipv6_hdr(skb)->saddr,
				    &ipv6_hdr(skb)->daddr, t1);
771 772 773
	}
#endif

774
	memset(&fl6, 0, sizeof(fl6));
A
Alexey Dobriyan 已提交
775 776
	fl6.daddr = ipv6_hdr(skb)->saddr;
	fl6.saddr = ipv6_hdr(skb)->daddr;
L
Linus Torvalds 已提交
777

778 779 780
	buff->ip_summed = CHECKSUM_PARTIAL;
	buff->csum = 0;

781
	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
L
Linus Torvalds 已提交
782

783
	fl6.flowi6_proto = IPPROTO_TCP;
A
Alexey Kuznetsov 已提交
784 785
	if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
		fl6.flowi6_oif = inet6_iif(skb);
786 787
	fl6.fl6_dport = t1->dest;
	fl6.fl6_sport = t1->source;
788
	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
L
Linus Torvalds 已提交
789

790 791 792 793
	/* Pass a socket to ip6_dst_lookup either it is for RST
	 * Underlying function will use this to retrieve the network
	 * namespace
	 */
794
	dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
795 796
	if (!IS_ERR(dst)) {
		skb_dst_set(buff, dst);
797
		ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
798 799 800 801
		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
802 803 804 805 806
	}

	kfree_skb(buff);
}

807
static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
808
{
809
	const struct tcphdr *th = tcp_hdr(skb);
810
	u32 seq = 0, ack_seq = 0;
811
	struct tcp_md5sig_key *key = NULL;
812 813 814 815 816 817 818
#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
819

820
	if (th->rst)
L
Linus Torvalds 已提交
821 822
		return;

823 824
	if (!ipv6_unicast_destination(skb))
		return;
L
Linus Torvalds 已提交
825

826
#ifdef CONFIG_TCP_MD5SIG
827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
	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;
	}
853 854
#endif

855 856 857 858 859
	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
860

861
	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
862 863 864 865 866 867 868 869

#ifdef CONFIG_TCP_MD5SIG
release_sk1:
	if (sk1) {
		rcu_read_unlock();
		sock_put(sk1);
	}
#endif
870
}
L
Linus Torvalds 已提交
871

872
static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
873
			    struct tcp_md5sig_key *key, u8 tclass)
874
{
875
	tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
L
Linus Torvalds 已提交
876 877 878 879
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
880
	struct inet_timewait_sock *tw = inet_twsk(sk);
881
	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
L
Linus Torvalds 已提交
882

883
	tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
884
			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
885 886
			tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
			tw->tw_tclass);
L
Linus Torvalds 已提交
887

888
	inet_twsk_put(tw);
L
Linus Torvalds 已提交
889 890
}

891 892
static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
				  struct request_sock *req)
L
Linus Torvalds 已提交
893
{
894
	tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
895
			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
L
Linus Torvalds 已提交
896 897 898 899 900
}


static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
{
901
	struct request_sock *req, **prev;
902
	const struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
903 904 905
	struct sock *nsk;

	/* Find possible connection requests. */
906
	req = inet6_csk_search_req(sk, &prev, th->source,
907 908
				   &ipv6_hdr(skb)->saddr,
				   &ipv6_hdr(skb)->daddr, inet6_iif(skb));
L
Linus Torvalds 已提交
909
	if (req)
910
		return tcp_check_req(sk, skb, req, prev, false);
L
Linus Torvalds 已提交
911

912
	nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
913 914
			&ipv6_hdr(skb)->saddr, th->source,
			&ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
915 916 917 918 919 920

	if (nsk) {
		if (nsk->sk_state != TCP_TIME_WAIT) {
			bh_lock_sock(nsk);
			return nsk;
		}
921
		inet_twsk_put(inet_twsk(nsk));
L
Linus Torvalds 已提交
922 923 924
		return NULL;
	}

925
#ifdef CONFIG_SYN_COOKIES
926
	if (!th->syn)
927
		sk = cookie_v6_check(sk, skb);
L
Linus Torvalds 已提交
928 929 930 931 932 933 934 935 936
#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)
{
937
	struct tcp_extend_values tmp_ext;
938
	struct tcp_options_received tmp_opt;
939
	const u8 *hash_location;
940
	struct request_sock *req;
941
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
942 943
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_sock *tp = tcp_sk(sk);
944
	__u32 isn = TCP_SKB_CB(skb)->when;
945
	struct dst_entry *dst = NULL;
946
	struct flowi6 fl6;
E
Eric Dumazet 已提交
947
	bool want_cookie = false;
L
Linus Torvalds 已提交
948 949 950 951 952

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

	if (!ipv6_unicast_destination(skb))
953
		goto drop;
L
Linus Torvalds 已提交
954

955
	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
956 957 958
		want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
		if (!want_cookie)
			goto drop;
L
Linus Torvalds 已提交
959 960
	}

961
	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
L
Linus Torvalds 已提交
962 963
		goto drop;

964
	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
L
Linus Torvalds 已提交
965 966 967
	if (req == NULL)
		goto drop;

968 969 970 971
#ifdef CONFIG_TCP_MD5SIG
	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
#endif

L
Linus Torvalds 已提交
972 973 974
	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;
Y
Yuchung Cheng 已提交
975
	tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);
976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991

	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 */
992
		d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
993 994 995 996
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;
		*mess++ ^= *d++;
997
		d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
998 999 1000 1001 1002 1003 1004 1005 1006
		*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
1007

E
Eric Dumazet 已提交
1008
		want_cookie = false;	/* not our kind of cookie */
1009 1010 1011 1012 1013 1014 1015 1016 1017 1018
		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
1019

1020
	if (want_cookie && !tmp_opt.saw_tstamp)
1021 1022
		tcp_clear_options(&tmp_opt);

L
Linus Torvalds 已提交
1023 1024 1025
	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
	tcp_openreq_init(req, &tmp_opt, skb);

1026
	treq = inet6_rsk(req);
A
Alexey Dobriyan 已提交
1027 1028
	treq->rmt_addr = ipv6_hdr(skb)->saddr;
	treq->loc_addr = ipv6_hdr(skb)->daddr;
1029
	if (!want_cookie || tmp_opt.tstamp_ok)
1030
		TCP_ECN_create_request(req, skb, sock_net(sk));
1031

1032 1033 1034 1035 1036 1037 1038
	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);

1039
	if (!isn) {
1040 1041 1042 1043 1044 1045
		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;
		}
1046 1047

		if (want_cookie) {
1048 1049
			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
			req->cookie_ts = tmp_opt.tstamp_ok;
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
			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 &&
1064 1065
		    (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
			if (!tcp_peer_is_proven(req, dst, true)) {
1066 1067 1068 1069 1070 1071 1072 1073
				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)) &&
1074
			 !tcp_peer_is_proven(req, dst, false)) {
1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
			/* 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;
1085
		}
1086 1087

		isn = tcp_v6_init_sequence(skb);
1088
	}
1089
have_isn:
1090
	tcp_rsk(req)->snt_isn = isn;
L
Linus Torvalds 已提交
1091

1092 1093
	if (security_inet_conn_request(sk, skb, req))
		goto drop_and_release;
1094

1095
	if (tcp_v6_send_synack(sk, dst, &fl6, req,
1096 1097
			       (struct request_values *)&tmp_ext,
			       skb_get_queue_mapping(skb)) ||
1098
	    want_cookie)
1099
		goto drop_and_free;
L
Linus Torvalds 已提交
1100

1101
	tcp_rsk(req)->snt_synack = tcp_time_stamp;
1102
	tcp_rsk(req)->listener = NULL;
1103 1104
	inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
	return 0;
L
Linus Torvalds 已提交
1105

1106 1107
drop_and_release:
	dst_release(dst);
1108 1109
drop_and_free:
	reqsk_free(req);
L
Linus Torvalds 已提交
1110 1111 1112 1113 1114
drop:
	return 0; /* don't send reset */
}

static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1115
					  struct request_sock *req,
L
Linus Torvalds 已提交
1116 1117
					  struct dst_entry *dst)
{
1118
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
1119 1120 1121 1122 1123
	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
	struct tcp6_sock *newtcp6sk;
	struct inet_sock *newinet;
	struct tcp_sock *newtp;
	struct sock *newsk;
1124 1125 1126
#ifdef CONFIG_TCP_MD5SIG
	struct tcp_md5sig_key *key;
#endif
1127
	struct flowi6 fl6;
L
Linus Torvalds 已提交
1128 1129 1130 1131 1132 1133 1134 1135

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

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

1136
		if (newsk == NULL)
L
Linus Torvalds 已提交
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
			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
1148
		ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
L
Linus Torvalds 已提交
1149

E
Eric Dumazet 已提交
1150
		ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
L
Linus Torvalds 已提交
1151

A
Alexey Dobriyan 已提交
1152
		newnp->rcv_saddr = newnp->saddr;
L
Linus Torvalds 已提交
1153

1154
		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
L
Linus Torvalds 已提交
1155
		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1156 1157 1158 1159
#ifdef CONFIG_TCP_MD5SIG
		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif

1160 1161
		newnp->ipv6_ac_list = NULL;
		newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1162 1163
		newnp->pktoptions  = NULL;
		newnp->opt	   = NULL;
1164
		newnp->mcast_oif   = inet6_iif(skb);
1165
		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1166
		newnp->rcv_tclass  = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1167

1168 1169 1170 1171
		/*
		 * 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
1172 1173 1174
		 */

		/* It is tricky place. Until this moment IPv4 tcp
1175
		   worked with IPv6 icsk.icsk_af_ops.
L
Linus Torvalds 已提交
1176 1177
		   Sync it now.
		 */
1178
		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
L
Linus Torvalds 已提交
1179 1180 1181 1182

		return newsk;
	}

1183
	treq = inet6_rsk(req);
L
Linus Torvalds 已提交
1184 1185 1186 1187

	if (sk_acceptq_is_full(sk))
		goto out_overflow;

1188
	if (!dst) {
1189
		dst = inet6_csk_route_req(sk, &fl6, req);
1190
		if (!dst)
L
Linus Torvalds 已提交
1191
			goto out;
1192
	}
L
Linus Torvalds 已提交
1193 1194 1195

	newsk = tcp_create_openreq_child(sk, req, skb);
	if (newsk == NULL)
1196
		goto out_nonewsk;
L
Linus Torvalds 已提交
1197

1198 1199 1200 1201 1202
	/*
	 * 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
1203

1204
	newsk->sk_gso_type = SKB_GSO_TCPV6;
1205
	__ip6_dst_store(newsk, dst, NULL, NULL);
1206
	inet6_sk_rx_dst_set(newsk, skb);
L
Linus Torvalds 已提交
1207 1208 1209 1210 1211 1212 1213 1214 1215 1216

	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
1217 1218 1219
	newnp->daddr = treq->rmt_addr;
	newnp->saddr = treq->loc_addr;
	newnp->rcv_saddr = treq->loc_addr;
1220
	newsk->sk_bound_dev_if = treq->iif;
L
Linus Torvalds 已提交
1221

1222
	/* Now IPv6 options...
L
Linus Torvalds 已提交
1223 1224 1225

	   First: no IPv4 options.
	 */
1226
	newinet->inet_opt = NULL;
1227
	newnp->ipv6_ac_list = NULL;
1228
	newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1229 1230 1231 1232 1233 1234

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

	/* Clone pktoptions received with SYN */
	newnp->pktoptions = NULL;
1235
	if (treq->pktopts != NULL) {
1236 1237
		newnp->pktoptions = skb_clone(treq->pktopts,
					      sk_gfp_atomic(sk, GFP_ATOMIC));
1238
		consume_skb(treq->pktopts);
1239
		treq->pktopts = NULL;
L
Linus Torvalds 已提交
1240 1241 1242 1243
		if (newnp->pktoptions)
			skb_set_owner_r(newnp->pktoptions, newsk);
	}
	newnp->opt	  = NULL;
1244
	newnp->mcast_oif  = inet6_iif(skb);
1245
	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1246
	newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1247 1248 1249 1250 1251 1252 1253

	/* 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.
	 */
1254 1255
	if (np->opt)
		newnp->opt = ipv6_dup_options(newsk, np->opt);
L
Linus Torvalds 已提交
1256

1257
	inet_csk(newsk)->icsk_ext_hdr_len = 0;
L
Linus Torvalds 已提交
1258
	if (newnp->opt)
1259 1260
		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
						     newnp->opt->opt_flen);
L
Linus Torvalds 已提交
1261

J
John Heffner 已提交
1262
	tcp_mtup_init(newsk);
L
Linus Torvalds 已提交
1263
	tcp_sync_mss(newsk, dst_mtu(dst));
1264
	newtp->advmss = dst_metric_advmss(dst);
1265 1266 1267 1268
	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
1269
	tcp_initialize_rcv_mss(newsk);
1270
	tcp_synack_rtt_meas(newsk, req);
1271
	newtp->total_retrans = req->num_retrans;
L
Linus Torvalds 已提交
1272

E
Eric Dumazet 已提交
1273 1274
	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
L
Linus Torvalds 已提交
1275

1276 1277 1278 1279 1280 1281 1282 1283
#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
1284
		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1285 1286
			       AF_INET6, key->key, key->keylen,
			       sk_gfp_atomic(sk, GFP_ATOMIC));
1287 1288 1289
	}
#endif

1290
	if (__inet_inherit_port(sk, newsk) < 0) {
1291 1292
		inet_csk_prepare_forced_close(newsk);
		tcp_done(newsk);
1293 1294
		goto out;
	}
1295
	__inet6_hash(newsk, NULL);
L
Linus Torvalds 已提交
1296 1297 1298 1299

	return newsk;

out_overflow:
1300
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1301
out_nonewsk:
L
Linus Torvalds 已提交
1302
	dst_release(dst);
1303 1304
out:
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
L
Linus Torvalds 已提交
1305 1306 1307
	return NULL;
}

1308
static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
L
Linus Torvalds 已提交
1309
{
1310
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
H
Herbert Xu 已提交
1311
		if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1312
				  &ipv6_hdr(skb)->daddr, skb->csum)) {
1313
			skb->ip_summed = CHECKSUM_UNNECESSARY;
L
Linus Torvalds 已提交
1314
			return 0;
1315
		}
L
Linus Torvalds 已提交
1316
	}
1317

H
Herbert Xu 已提交
1318
	skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1319 1320
					      &ipv6_hdr(skb)->saddr,
					      &ipv6_hdr(skb)->daddr, 0));
1321

L
Linus Torvalds 已提交
1322
	if (skb->len <= 76) {
1323
		return __skb_checksum_complete(skb);
L
Linus Torvalds 已提交
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352
	}
	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);

1353 1354 1355 1356 1357
#ifdef CONFIG_TCP_MD5SIG
	if (tcp_v6_inbound_md5_hash (sk, skb))
		goto discard;
#endif

1358
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376
		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.
1377
					       --ANK (980728)
L
Linus Torvalds 已提交
1378 1379
	 */
	if (np->rxopt.all)
1380
		opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
L
Linus Torvalds 已提交
1381 1382

	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
E
Eric Dumazet 已提交
1383 1384
		struct dst_entry *dst = sk->sk_rx_dst;

1385
		sock_rps_save_rxhash(sk, skb);
E
Eric Dumazet 已提交
1386 1387 1388 1389 1390 1391 1392 1393
		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;
			}
		}

1394
		if (tcp_rcv_established(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;
	}

1401
	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
L
Linus Torvalds 已提交
1402 1403
		goto csum_err;

1404
	if (sk->sk_state == TCP_LISTEN) {
L
Linus Torvalds 已提交
1405 1406 1407 1408 1409 1410 1411 1412 1413
		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..
		 */
1414
		if(nsk != sk) {
1415
			sock_rps_save_rxhash(nsk, skb);
L
Linus Torvalds 已提交
1416 1417 1418 1419 1420 1421
			if (tcp_child_process(sk, nsk, skb))
				goto reset;
			if (opt_skb)
				__kfree_skb(opt_skb);
			return 0;
		}
1422
	} else
1423
		sock_rps_save_rxhash(sk, skb);
L
Linus Torvalds 已提交
1424

1425
	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1426 1427 1428 1429 1430 1431
		goto reset;
	if (opt_skb)
		goto ipv6_pktoptions;
	return 0;

reset:
1432
	tcp_v6_send_reset(sk, skb);
L
Linus Torvalds 已提交
1433 1434 1435 1436 1437 1438
discard:
	if (opt_skb)
		__kfree_skb(opt_skb);
	kfree_skb(skb);
	return 0;
csum_err:
1439
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
	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))) {
1454
		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1455
			np->mcast_oif = inet6_iif(opt_skb);
1456
		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1457
			np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1458 1459
		if (np->rxopt.bits.rxtclass)
			np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1460 1461 1462 1463 1464 1465 1466 1467 1468
		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);
		}
	}

1469
	kfree_skb(opt_skb);
L
Linus Torvalds 已提交
1470 1471 1472
	return 0;
}

1473
static int tcp_v6_rcv(struct sk_buff *skb)
L
Linus Torvalds 已提交
1474
{
1475
	const struct tcphdr *th;
1476
	const struct ipv6hdr *hdr;
L
Linus Torvalds 已提交
1477 1478
	struct sock *sk;
	int ret;
1479
	struct net *net = dev_net(skb->dev);
L
Linus Torvalds 已提交
1480 1481 1482 1483 1484 1485 1486

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

	/*
	 *	Count it even if it's bad.
	 */
1487
	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
L
Linus Torvalds 已提交
1488 1489 1490 1491

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

1492
	th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1493 1494 1495 1496 1497 1498

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

1499
	if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
L
Linus Torvalds 已提交
1500 1501
		goto bad_packet;

1502
	th = tcp_hdr(skb);
1503
	hdr = ipv6_hdr(skb);
L
Linus Torvalds 已提交
1504 1505 1506 1507 1508
	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;
1509
	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
L
Linus Torvalds 已提交
1510 1511
	TCP_SKB_CB(skb)->sacked = 0;

1512
	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
L
Linus Torvalds 已提交
1513 1514 1515 1516 1517 1518 1519
	if (!sk)
		goto no_tcp_socket;

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

1520 1521 1522 1523 1524
	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
1525 1526 1527
	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_and_relse;

1528
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1529 1530 1531 1532
		goto discard_and_relse;

	skb->dev = NULL;

1533
	bh_lock_sock_nested(sk);
L
Linus Torvalds 已提交
1534 1535
	ret = 0;
	if (!sock_owned_by_user(sk)) {
C
Chris Leech 已提交
1536
#ifdef CONFIG_NET_DMA
1537
		struct tcp_sock *tp = tcp_sk(sk);
1538
		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1539
			tp->ucopy.dma_chan = net_dma_find_channel();
1540 1541 1542
		if (tp->ucopy.dma_chan)
			ret = tcp_v6_do_rcv(sk, skb);
		else
C
Chris Leech 已提交
1543 1544 1545 1546 1547
#endif
		{
			if (!tcp_prequeue(sk, skb))
				ret = tcp_v6_do_rcv(sk, skb);
		}
1548 1549
	} else if (unlikely(sk_add_backlog(sk, skb,
					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
Z
Zhu Yi 已提交
1550
		bh_unlock_sock(sk);
1551
		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
Z
Zhu Yi 已提交
1552 1553
		goto discard_and_relse;
	}
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564
	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:
1565
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1566
	} else {
1567
		tcp_v6_send_reset(NULL, skb);
L
Linus Torvalds 已提交
1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584
	}

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)) {
1585
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1586 1587 1588 1589
		goto discard_it;
	}

	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1590
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1591
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1592 1593 1594
		goto discard_it;
	}

1595
	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
L
Linus Torvalds 已提交
1596 1597 1598 1599
	case TCP_TW_SYN:
	{
		struct sock *sk2;

1600
		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1601
					    &ipv6_hdr(skb)->daddr,
1602
					    ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
1603
		if (sk2 != NULL) {
1604 1605 1606
			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
1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621
			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
1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
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;
1649

E
Eric Dumazet 已提交
1650
			if (dst)
E
Eric Dumazet 已提交
1651
				dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
E
Eric Dumazet 已提交
1652
			if (dst &&
1653
			    inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
E
Eric Dumazet 已提交
1654 1655 1656 1657 1658
				skb_dst_set_noref(skb, dst);
		}
	}
}

1659 1660 1661 1662 1663 1664
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,
};

1665
static const struct inet_connection_sock_af_ops ipv6_specific = {
1666 1667 1668
	.queue_xmit	   = inet6_csk_xmit,
	.send_check	   = tcp_v6_send_check,
	.rebuild_header	   = inet6_sk_rebuild_header,
E
Eric Dumazet 已提交
1669
	.sk_rx_dst_set	   = inet6_sk_rx_dst_set,
1670 1671 1672
	.conn_request	   = tcp_v6_conn_request,
	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
	.net_header_len	   = sizeof(struct ipv6hdr),
1673
	.net_frag_header_len = sizeof(struct frag_hdr),
1674 1675 1676 1677
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1678
	.bind_conflict	   = inet6_csk_bind_conflict,
1679
#ifdef CONFIG_COMPAT
1680 1681
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1682
#endif
L
Linus Torvalds 已提交
1683 1684
};

1685
#ifdef CONFIG_TCP_MD5SIG
1686
static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1687
	.md5_lookup	=	tcp_v6_md5_lookup,
1688
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
1689 1690
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1691
#endif
1692

L
Linus Torvalds 已提交
1693 1694 1695 1696
/*
 *	TCP over IPv4 via INET6 API
 */

1697
static const struct inet_connection_sock_af_ops ipv6_mapped = {
1698 1699 1700
	.queue_xmit	   = ip_queue_xmit,
	.send_check	   = tcp_v4_send_check,
	.rebuild_header	   = inet_sk_rebuild_header,
1701
	.sk_rx_dst_set	   = inet_sk_rx_dst_set,
1702 1703 1704 1705 1706 1707 1708
	.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),
1709
	.bind_conflict	   = inet6_csk_bind_conflict,
1710
#ifdef CONFIG_COMPAT
1711 1712
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1713
#endif
L
Linus Torvalds 已提交
1714 1715
};

1716
#ifdef CONFIG_TCP_MD5SIG
1717
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1718
	.md5_lookup	=	tcp_v4_md5_lookup,
1719
	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
1720 1721
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1722
#endif
1723

L
Linus Torvalds 已提交
1724 1725 1726 1727 1728
/* 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)
{
1729
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1730

1731
	tcp_init_sock(sk);
L
Linus Torvalds 已提交
1732

1733
	icsk->icsk_af_ops = &ipv6_specific;
L
Linus Torvalds 已提交
1734

1735
#ifdef CONFIG_TCP_MD5SIG
1736
	tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1737 1738
#endif

L
Linus Torvalds 已提交
1739 1740 1741
	return 0;
}

1742
static void tcp_v6_destroy_sock(struct sock *sk)
L
Linus Torvalds 已提交
1743 1744
{
	tcp_v4_destroy_sock(sk);
1745
	inet6_destroy_sock(sk);
L
Linus Torvalds 已提交
1746 1747
}

1748
#ifdef CONFIG_PROC_FS
L
Linus Torvalds 已提交
1749
/* Proc filesystem TCPv6 sock list dumping. */
1750
static void get_openreq6(struct seq_file *seq,
1751
			 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
L
Linus Torvalds 已提交
1752 1753
{
	int ttd = req->expires - jiffies;
1754 1755
	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
1756 1757 1758 1759 1760 1761

	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
1762
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1763 1764 1765
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3],
1766
		   ntohs(inet_rsk(req)->loc_port),
L
Linus Torvalds 已提交
1767 1768
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3],
1769
		   ntohs(inet_rsk(req)->rmt_port),
L
Linus Torvalds 已提交
1770 1771
		   TCP_SYN_RECV,
		   0,0, /* could print option size, but that is af dependent. */
1772 1773
		   1,   /* timers active (only the expire timer) */
		   jiffies_to_clock_t(ttd),
1774
		   req->num_timeout,
1775
		   from_kuid_munged(seq_user_ns(seq), uid),
1776
		   0,  /* non standard timer */
L
Linus Torvalds 已提交
1777 1778 1779 1780 1781 1782
		   0, /* open_requests have no inode */
		   0, req);
}

static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
{
1783
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1784 1785 1786
	__u16 destp, srcp;
	int timer_active;
	unsigned long timer_expires;
1787 1788
	const struct inet_sock *inet = inet_sk(sp);
	const struct tcp_sock *tp = tcp_sk(sp);
1789
	const struct inet_connection_sock *icsk = inet_csk(sp);
1790
	const struct ipv6_pinfo *np = inet6_sk(sp);
L
Linus Torvalds 已提交
1791 1792 1793

	dest  = &np->daddr;
	src   = &np->rcv_saddr;
E
Eric Dumazet 已提交
1794 1795
	destp = ntohs(inet->inet_dport);
	srcp  = ntohs(inet->inet_sport);
1796 1797

	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
L
Linus Torvalds 已提交
1798
		timer_active	= 1;
1799 1800
		timer_expires	= icsk->icsk_timeout;
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
L
Linus Torvalds 已提交
1801
		timer_active	= 4;
1802
		timer_expires	= icsk->icsk_timeout;
L
Linus Torvalds 已提交
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
	} 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
1813
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
L
Linus Torvalds 已提交
1814 1815 1816 1817 1818
		   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,
1819
		   sp->sk_state,
1820 1821
		   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
1822
		   timer_active,
1823
		   jiffies_delta_to_clock_t(timer_expires - jiffies),
1824
		   icsk->icsk_retransmits,
1825
		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1826
		   icsk->icsk_probes_out,
L
Linus Torvalds 已提交
1827 1828
		   sock_i_ino(sp),
		   atomic_read(&sp->sk_refcnt), sp,
1829 1830
		   jiffies_to_clock_t(icsk->icsk_rto),
		   jiffies_to_clock_t(icsk->icsk_ack.ato),
1831
		   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
I
Ilpo Järvinen 已提交
1832 1833
		   tp->snd_cwnd,
		   tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
L
Linus Torvalds 已提交
1834 1835 1836
		   );
}

1837
static void get_timewait6_sock(struct seq_file *seq,
1838
			       struct inet_timewait_sock *tw, int i)
L
Linus Torvalds 已提交
1839
{
1840
	const struct in6_addr *dest, *src;
L
Linus Torvalds 已提交
1841
	__u16 destp, srcp;
1842
	const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1843
	long delta = tw->tw_ttd - jiffies;
L
Linus Torvalds 已提交
1844

1845 1846
	dest = &tw6->tw_v6_daddr;
	src  = &tw6->tw_v6_rcv_saddr;
L
Linus Torvalds 已提交
1847 1848 1849 1850 1851
	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
1852
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
L
Linus Torvalds 已提交
1853 1854 1855 1856 1857 1858
		   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,
1859
		   3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
L
Linus Torvalds 已提交
1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893
		   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;
}

1894 1895 1896 1897 1898 1899 1900 1901
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
1902 1903 1904
static struct tcp_seq_afinfo tcp6_seq_afinfo = {
	.name		= "tcp6",
	.family		= AF_INET6,
1905
	.seq_fops	= &tcp6_afinfo_seq_fops,
1906 1907 1908
	.seq_ops	= {
		.show		= tcp6_seq_show,
	},
L
Linus Torvalds 已提交
1909 1910
};

1911
int __net_init tcp6_proc_init(struct net *net)
L
Linus Torvalds 已提交
1912
{
1913
	return tcp_proc_register(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
1914 1915
}

1916
void tcp6_proc_exit(struct net *net)
L
Linus Torvalds 已提交
1917
{
1918
	tcp_proc_unregister(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
1919 1920 1921 1922 1923 1924 1925 1926 1927
}
#endif

struct proto tcpv6_prot = {
	.name			= "TCPv6",
	.owner			= THIS_MODULE,
	.close			= tcp_close,
	.connect		= tcp_v6_connect,
	.disconnect		= tcp_disconnect,
1928
	.accept			= inet_csk_accept,
L
Linus Torvalds 已提交
1929 1930 1931 1932 1933 1934 1935
	.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,
1936 1937
	.sendmsg		= tcp_sendmsg,
	.sendpage		= tcp_sendpage,
L
Linus Torvalds 已提交
1938
	.backlog_rcv		= tcp_v6_do_rcv,
E
Eric Dumazet 已提交
1939
	.release_cb		= tcp_release_cb,
1940
	.mtu_reduced		= tcp_v6_mtu_reduced,
L
Linus Torvalds 已提交
1941
	.hash			= tcp_v6_hash,
1942 1943
	.unhash			= inet_unhash,
	.get_port		= inet_csk_get_port,
L
Linus Torvalds 已提交
1944 1945 1946 1947
	.enter_memory_pressure	= tcp_enter_memory_pressure,
	.sockets_allocated	= &tcp_sockets_allocated,
	.memory_allocated	= &tcp_memory_allocated,
	.memory_pressure	= &tcp_memory_pressure,
1948
	.orphan_count		= &tcp_orphan_count,
L
Linus Torvalds 已提交
1949 1950 1951 1952
	.sysctl_wmem		= sysctl_tcp_wmem,
	.sysctl_rmem		= sysctl_tcp_rmem,
	.max_header		= MAX_TCP_HEADER,
	.obj_size		= sizeof(struct tcp6_sock),
1953
	.slab_flags		= SLAB_DESTROY_BY_RCU,
1954
	.twsk_prot		= &tcp6_timewait_sock_ops,
1955
	.rsk_prot		= &tcp6_request_sock_ops,
1956
	.h.hashinfo		= &tcp_hashinfo,
1957
	.no_autobind		= true,
1958 1959 1960 1961
#ifdef CONFIG_COMPAT
	.compat_setsockopt	= compat_tcp_setsockopt,
	.compat_getsockopt	= compat_tcp_getsockopt,
#endif
A
Andrew Morton 已提交
1962
#ifdef CONFIG_MEMCG_KMEM
G
Glauber Costa 已提交
1963 1964
	.proto_cgroup		= tcp_proto_cgroup,
#endif
L
Linus Torvalds 已提交
1965 1966
};

1967
static const struct inet6_protocol tcpv6_protocol = {
E
Eric Dumazet 已提交
1968
	.early_demux	=	tcp_v6_early_demux,
L
Linus Torvalds 已提交
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979
	.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,
1980 1981
	.flags		=	INET_PROTOSW_PERMANENT |
				INET_PROTOSW_ICSK,
L
Linus Torvalds 已提交
1982 1983
};

1984
static int __net_init tcpv6_net_init(struct net *net)
1985
{
1986 1987
	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
				    SOCK_RAW, IPPROTO_TCP, net);
1988 1989
}

1990
static void __net_exit tcpv6_net_exit(struct net *net)
1991
{
1992
	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
E
Eric W. Biederman 已提交
1993 1994
}

1995
static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
E
Eric W. Biederman 已提交
1996 1997
{
	inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1998 1999 2000
}

static struct pernet_operations tcpv6_net_ops = {
E
Eric W. Biederman 已提交
2001 2002 2003
	.init	    = tcpv6_net_init,
	.exit	    = tcpv6_net_exit,
	.exit_batch = tcpv6_net_exit_batch,
2004 2005
};

2006
int __init tcpv6_init(void)
L
Linus Torvalds 已提交
2007
{
2008 2009
	int ret;

2010 2011
	ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
	if (ret)
2012
		goto out;
2013

L
Linus Torvalds 已提交
2014
	/* register inet6 protocol */
2015 2016 2017 2018
	ret = inet6_register_protosw(&tcpv6_protosw);
	if (ret)
		goto out_tcpv6_protocol;

2019
	ret = register_pernet_subsys(&tcpv6_net_ops);
2020 2021 2022 2023
	if (ret)
		goto out_tcpv6_protosw;
out:
	return ret;
2024

2025 2026
out_tcpv6_protosw:
	inet6_unregister_protosw(&tcpv6_protosw);
2027 2028
out_tcpv6_protocol:
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2029 2030 2031
	goto out;
}

2032
void tcpv6_exit(void)
2033
{
2034
	unregister_pernet_subsys(&tcpv6_net_ops);
2035 2036
	inet6_unregister_protosw(&tcpv6_protosw);
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
L
Linus Torvalds 已提交
2037
}