tcp_ipv6.c 52.5 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.
 */

#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>

#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 <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 struct inet_connection_sock_af_ops ipv6_mapped;
static struct inet_connection_sock_af_ops ipv6_specific;
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#ifdef CONFIG_TCP_MD5SIG
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static struct tcp_sock_af_ops tcp_sock_ipv6_specific;
static 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,
						   struct in6_addr *addr)
{
	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);
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		local_bh_enable();
	}
}

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static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len,
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				   struct in6_addr *saddr,
				   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(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);
	struct in6_addr *saddr = NULL, *final_p = NULL, final;
	struct flowi fl;
	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);

	memset(&fl, 0, sizeof(fl));

	if (np->sndflow) {
		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
		IP6_ECN_flow_init(fl.fl6_flowlabel);
		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
			struct ip6_flowlabel *flowlabel;
			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
			if (flowlabel == NULL)
				return -EINVAL;
			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
			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;
	}

	ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
	np->flow_label = fl.fl6_flowlabel;

	/*
	 *	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 {
			ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
				      inet->saddr);
			ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
				      inet->rcv_saddr);
		}

		return err;
	}

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

	fl.proto = IPPROTO_TCP;
	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
	ipv6_addr_copy(&fl.fl6_src,
		       (saddr ? saddr : &np->saddr));
	fl.oif = sk->sk_bound_dev_if;
	fl.fl_ip_dport = usin->sin6_port;
	fl.fl_ip_sport = inet->sport;

	if (np->opt && np->opt->srcrt) {
		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
		ipv6_addr_copy(&final, &fl.fl6_dst);
		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
		final_p = &final;
	}

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	security_sk_classify_flow(sk, &fl);

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	err = ip6_dst_lookup(sk, &dst, &fl);
	if (err)
		goto failure;
	if (final_p)
		ipv6_addr_copy(&fl.fl6_dst, final_p);

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	if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
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		if (err == -EREMOTE)
			err = ip6_dst_blackhole(sk, &dst, &fl);
		if (err < 0)
			goto failure;
	}
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	if (saddr == NULL) {
		saddr = &fl.fl6_src;
		ipv6_addr_copy(&np->rcv_saddr, saddr);
	}

	/* set the source address */
	ipv6_addr_copy(&np->saddr, saddr);
	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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	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);

	inet->dport = usin->sin6_port;

	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,
							     inet->sport,
							     inet->dport);

	err = tcp_connect(sk);
	if (err)
		goto late_failure;

	return 0;

late_failure:
	tcp_set_state(sk, TCP_CLOSE);
	__sk_dst_reset(sk);
failure:
	inet->dport = 0;
	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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		int type, int code, int offset, __be32 info)
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{
	struct ipv6hdr *hdr = (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;

	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) {
		struct dst_entry *dst = NULL;

		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);
			struct flowi fl;

			/* BUGGG_FUTURE: Again, it is not clear how
			   to handle rthdr case. Ignore this complexity
			   for now.
			 */
			memset(&fl, 0, sizeof(fl));
			fl.proto = IPPROTO_TCP;
			ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
			ipv6_addr_copy(&fl.fl6_src, &np->saddr);
			fl.oif = sk->sk_bound_dev_if;
			fl.fl_ip_dport = inet->dport;
			fl.fl_ip_sport = inet->sport;
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			security_skb_classify_flow(skb, &fl);
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			if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
				sk->sk_err_soft = -err;
				goto out;
			}

			if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
				sk->sk_err_soft = -err;
				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)
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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;
	struct in6_addr * final_p = NULL, final;
	struct flowi fl;
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	struct dst_entry *dst;
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	int err = -1;

	memset(&fl, 0, sizeof(fl));
	fl.proto = IPPROTO_TCP;
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	ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
	ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
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	fl.fl6_flowlabel = 0;
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	fl.oif = treq->iif;
	fl.fl_ip_dport = inet_rsk(req)->rmt_port;
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	fl.fl_ip_sport = inet_rsk(req)->loc_port;
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	security_req_classify_flow(req, &fl);
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	opt = np->opt;
	if (opt && opt->srcrt) {
		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
		ipv6_addr_copy(&final, &fl.fl6_dst);
		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
		final_p = &final;
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	}

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	err = ip6_dst_lookup(sk, &dst, &fl);
	if (err)
		goto done;
	if (final_p)
		ipv6_addr_copy(&fl.fl6_dst, final_p);
	if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
		goto done;

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	skb = tcp_make_synack(sk, dst, req);
	if (skb) {
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		struct tcphdr *th = tcp_hdr(skb);
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		th->check = tcp_v6_check(th, skb->len,
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					 &treq->loc_addr, &treq->rmt_addr,
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					 csum_partial(th, skb->len, skb->csum));
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		ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
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		err = ip6_xmit(sk, skb, &fl, opt, 0);
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		err = net_xmit_eval(err);
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	}

done:
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	if (opt && opt != np->opt)
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		sock_kfree_s(sk, opt, opt->tot_len);
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	dst_release(dst);
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	return err;
}

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static inline void syn_flood_warning(struct sk_buff *skb)
{
#ifdef CONFIG_SYN_COOKIES
	if (sysctl_tcp_syncookies)
		printk(KERN_INFO
		       "TCPv6: Possible SYN flooding on port %d. "
		       "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
	else
#endif
		printk(KERN_INFO
		       "TCPv6: Possible SYN flooding on port %d. "
		       "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
}

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static void tcp_v6_reqsk_destructor(struct request_sock *req)
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{
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	if (inet6_rsk(req)->pktopts)
		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,
						   struct in6_addr *addr)
{
	struct tcp_sock *tp = tcp_sk(sk);
	int i;

	BUG_ON(tp == NULL);

	if (!tp->md5sig_info || !tp->md5sig_info->entries6)
		return NULL;

	for (i = 0; i < tp->md5sig_info->entries6; i++) {
551
		if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
552
			return &tp->md5sig_info->keys6[i].base;
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572
	}
	return NULL;
}

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_md5_do_add(struct sock *sk, struct in6_addr *peer,
			     char *newkey, u8 newkeylen)
{
	/* Add key to the list */
573
	struct tcp_md5sig_key *key;
574 575 576
	struct tcp_sock *tp = tcp_sk(sk);
	struct tcp6_md5sig_key *keys;

577
	key = tcp_v6_md5_do_lookup(sk, peer);
578 579
	if (key) {
		/* modify existing entry - just update that one */
580 581 582
		kfree(key->key);
		key->key = newkey;
		key->keylen = newkeylen;
583 584 585 586 587 588 589 590
	} else {
		/* reallocate new list if current one is full. */
		if (!tp->md5sig_info) {
			tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
			if (!tp->md5sig_info) {
				kfree(newkey);
				return -ENOMEM;
			}
591
			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
592
		}
593 594 595 596
		if (tcp_alloc_md5sig_pool() == NULL) {
			kfree(newkey);
			return -ENOMEM;
		}
597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618
		if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
			keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
				       (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);

			if (!keys) {
				tcp_free_md5sig_pool();
				kfree(newkey);
				return -ENOMEM;
			}

			if (tp->md5sig_info->entries6)
				memmove(keys, tp->md5sig_info->keys6,
					(sizeof (tp->md5sig_info->keys6[0]) *
					 tp->md5sig_info->entries6));

			kfree(tp->md5sig_info->keys6);
			tp->md5sig_info->keys6 = keys;
			tp->md5sig_info->alloced6++;
		}

		ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
			       peer);
619 620
		tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
		tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639

		tp->md5sig_info->entries6++;
	}
	return 0;
}

static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
			       u8 *newkey, __u8 newkeylen)
{
	return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
				 newkey, newkeylen);
}

static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
{
	struct tcp_sock *tp = tcp_sk(sk);
	int i;

	for (i = 0; i < tp->md5sig_info->entries6; i++) {
640
		if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
641
			/* Free the key */
642
			kfree(tp->md5sig_info->keys6[i].base.key);
643 644 645 646 647
			tp->md5sig_info->entries6--;

			if (tp->md5sig_info->entries6 == 0) {
				kfree(tp->md5sig_info->keys6);
				tp->md5sig_info->keys6 = NULL;
648
				tp->md5sig_info->alloced6 = 0;
649 650 651 652 653 654 655 656
			} else {
				/* shrink the database */
				if (tp->md5sig_info->entries6 != i)
					memmove(&tp->md5sig_info->keys6[i],
						&tp->md5sig_info->keys6[i+1],
						(tp->md5sig_info->entries6 - i)
						* sizeof (tp->md5sig_info->keys6[0]));
			}
657 658
			tcp_free_md5sig_pool();
			return 0;
659 660 661 662 663 664 665 666 667 668 669 670
		}
	}
	return -ENOENT;
}

static void tcp_v6_clear_md5_list (struct sock *sk)
{
	struct tcp_sock *tp = tcp_sk(sk);
	int i;

	if (tp->md5sig_info->entries6) {
		for (i = 0; i < tp->md5sig_info->entries6; i++)
671
			kfree(tp->md5sig_info->keys6[i].base.key);
672 673 674 675 676 677 678 679 680 681
		tp->md5sig_info->entries6 = 0;
		tcp_free_md5sig_pool();
	}

	kfree(tp->md5sig_info->keys6);
	tp->md5sig_info->keys6 = NULL;
	tp->md5sig_info->alloced6 = 0;

	if (tp->md5sig_info->entries4) {
		for (i = 0; i < tp->md5sig_info->entries4; i++)
682
			kfree(tp->md5sig_info->keys4[i].base.key);
683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710
		tp->md5sig_info->entries4 = 0;
		tcp_free_md5sig_pool();
	}

	kfree(tp->md5sig_info->keys4);
	tp->md5sig_info->keys4 = NULL;
	tp->md5sig_info->alloced4 = 0;
}

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;
	u8 *newkey;

	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) {
		if (!tcp_sk(sk)->md5sig_info)
			return -ENOENT;
B
Brian Haley 已提交
711
		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
			return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
		return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
	}

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

	if (!tcp_sk(sk)->md5sig_info) {
		struct tcp_sock *tp = tcp_sk(sk);
		struct tcp_md5sig_info *p;

		p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
		if (!p)
			return -ENOMEM;

		tp->md5sig_info = p;
728
		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
729 730
	}

A
Arnaldo Carvalho de Melo 已提交
731
	newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
732 733
	if (!newkey)
		return -ENOMEM;
B
Brian Haley 已提交
734
	if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
735 736 737 738 739 740
		return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
					 newkey, cmd.tcpm_keylen);
	}
	return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
}

741 742 743
static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
					struct in6_addr *daddr,
					struct in6_addr *saddr, int nbytes)
744 745
{
	struct tcp6_pseudohdr *bp;
746
	struct scatterlist sg;
747

748 749 750 751
	bp = &hp->md5_blk.ip6;
	/* 1. TCP pseudo-header (RFC2460) */
	ipv6_addr_copy(&bp->saddr, saddr);
	ipv6_addr_copy(&bp->daddr, daddr);
752
	bp->protocol = cpu_to_be32(IPPROTO_TCP);
A
Adam Langley 已提交
753
	bp->len = cpu_to_be32(nbytes);
754

755 756 757
	sg_init_one(&sg, bp, sizeof(*bp));
	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
}
758

759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
			       struct in6_addr *daddr, struct in6_addr *saddr,
			       struct tcphdr *th)
{
	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))
780 781 782 783
		goto clear_hash;

	tcp_put_md5sig_pool();
	return 0;
784

785 786 787 788
clear_hash:
	tcp_put_md5sig_pool();
clear_hash_noput:
	memset(md5_hash, 0, 16);
789
	return 1;
790 791
}

792 793 794
static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
			       struct sock *sk, struct request_sock *req,
			       struct sk_buff *skb)
795 796
{
	struct in6_addr *saddr, *daddr;
797 798 799
	struct tcp_md5sig_pool *hp;
	struct hash_desc *desc;
	struct tcphdr *th = tcp_hdr(skb);
800 801 802 803

	if (sk) {
		saddr = &inet6_sk(sk)->saddr;
		daddr = &inet6_sk(sk)->daddr;
804
	} else if (req) {
805 806
		saddr = &inet6_rsk(req)->loc_addr;
		daddr = &inet6_rsk(req)->rmt_addr;
807 808 809 810
	} else {
		struct ipv6hdr *ip6h = ipv6_hdr(skb);
		saddr = &ip6h->saddr;
		daddr = &ip6h->daddr;
811
	}
812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839

	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;
840 841 842 843 844 845
}

static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
{
	__u8 *hash_location = NULL;
	struct tcp_md5sig_key *hash_expected;
846
	struct ipv6hdr *ip6h = ipv6_hdr(skb);
847
	struct tcphdr *th = tcp_hdr(skb);
848 849 850 851
	int genhash;
	u8 newhash[16];

	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
852
	hash_location = tcp_parse_md5sig_option(th);
853

854 855 856 857 858 859
	/* 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);
860 861 862
		return 1;
	}

863 864
	if (!hash_expected && hash_location) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
865 866 867 868
		return 1;
	}

	/* check the signature */
869 870 871 872
	genhash = tcp_v6_md5_hash_skb(newhash,
				      hash_expected,
				      NULL, NULL, skb);

873 874
	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
		if (net_ratelimit()) {
H
Harvey Harrison 已提交
875
			printk(KERN_INFO "MD5 Hash %s for (%pI6, %u)->(%pI6, %u)\n",
876
			       genhash ? "failed" : "mismatch",
877 878
			       &ip6h->saddr, ntohs(th->source),
			       &ip6h->daddr, ntohs(th->dest));
879 880 881 882 883 884 885
		}
		return 1;
	}
	return 0;
}
#endif

886
struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
L
Linus Torvalds 已提交
887
	.family		=	AF_INET6,
888
	.obj_size	=	sizeof(struct tcp6_request_sock),
L
Linus Torvalds 已提交
889
	.rtx_syn_ack	=	tcp_v6_send_synack,
890 891
	.send_ack	=	tcp_v6_reqsk_send_ack,
	.destructor	=	tcp_v6_reqsk_destructor,
L
Linus Torvalds 已提交
892 893 894
	.send_reset	=	tcp_v6_send_reset
};

895
#ifdef CONFIG_TCP_MD5SIG
896
static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
897 898
	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
};
899
#endif
900

901 902 903
static struct timewait_sock_ops tcp6_timewait_sock_ops = {
	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
	.twsk_unique	= tcp_twsk_unique,
904
	.twsk_destructor= tcp_twsk_destructor,
905 906
};

907
static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
L
Linus Torvalds 已提交
908 909
{
	struct ipv6_pinfo *np = inet6_sk(sk);
910
	struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
911

912
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
L
Linus Torvalds 已提交
913
		th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
914
		skb->csum_start = skb_transport_header(skb) - skb->head;
A
Al Viro 已提交
915
		skb->csum_offset = offsetof(struct tcphdr, check);
L
Linus Torvalds 已提交
916
	} else {
917
		th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
918
					    csum_partial(th, th->doff<<2,
L
Linus Torvalds 已提交
919 920 921 922
							 skb->csum));
	}
}

923 924 925 926 927 928 929 930
static int tcp_v6_gso_send_check(struct sk_buff *skb)
{
	struct ipv6hdr *ipv6h;
	struct tcphdr *th;

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

931
	ipv6h = ipv6_hdr(skb);
932
	th = tcp_hdr(skb);
933 934 935 936

	th->check = 0;
	th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
				     IPPROTO_TCP, 0);
937
	skb->csum_start = skb_transport_header(skb) - skb->head;
A
Al Viro 已提交
938
	skb->csum_offset = offsetof(struct tcphdr, check);
939
	skb->ip_summed = CHECKSUM_PARTIAL;
940 941
	return 0;
}
L
Linus Torvalds 已提交
942

943 944
static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
				 u32 ts, struct tcp_md5sig_key *key, int rst)
L
Linus Torvalds 已提交
945
{
946
	struct tcphdr *th = tcp_hdr(skb), *t1;
L
Linus Torvalds 已提交
947 948
	struct sk_buff *buff;
	struct flowi fl;
949
	struct net *net = dev_net(skb->dst->dev);
950
	struct sock *ctl_sk = net->ipv6.tcp_sk;
951
	unsigned int tot_len = sizeof(struct tcphdr);
952
	__be32 *topt;
L
Linus Torvalds 已提交
953

954 955
	if (ts)
		tot_len += TCPOLEN_TSTAMP_ALIGNED;
956 957 958 959 960 961
#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
962
			 GFP_ATOMIC);
963 964
	if (buff == NULL)
		return;
L
Linus Torvalds 已提交
965

966
	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
L
Linus Torvalds 已提交
967

968
	t1 = (struct tcphdr *) skb_push(buff, tot_len);
L
Linus Torvalds 已提交
969 970 971 972 973

	/* Swap the send and the receive. */
	memset(t1, 0, sizeof(*t1));
	t1->dest = th->source;
	t1->source = th->dest;
974
	t1->doff = tot_len / 4;
975 976 977 978 979
	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
980

981 982
	topt = (__be32 *)(t1 + 1);

983 984 985 986 987 988 989
	if (ts) {
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
		*topt++ = htonl(tcp_time_stamp);
		*topt++ = htonl(ts);
	}

990 991
#ifdef CONFIG_TCP_MD5SIG
	if (key) {
992 993 994
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
995 996
				    &ipv6_hdr(skb)->saddr,
				    &ipv6_hdr(skb)->daddr, t1);
997 998 999
	}
#endif

1000
	buff->csum = csum_partial(t1, tot_len, 0);
L
Linus Torvalds 已提交
1001 1002

	memset(&fl, 0, sizeof(fl));
1003 1004
	ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
	ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
L
Linus Torvalds 已提交
1005 1006

	t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1007
				    tot_len, IPPROTO_TCP,
L
Linus Torvalds 已提交
1008 1009 1010
				    buff->csum);

	fl.proto = IPPROTO_TCP;
1011
	fl.oif = inet6_iif(skb);
L
Linus Torvalds 已提交
1012 1013
	fl.fl_ip_dport = t1->dest;
	fl.fl_ip_sport = t1->source;
V
Venkat Yekkirala 已提交
1014
	security_skb_classify_flow(skb, &fl);
L
Linus Torvalds 已提交
1015

1016 1017 1018 1019
	/* Pass a socket to ip6_dst_lookup either it is for RST
	 * Underlying function will use this to retrieve the network
	 * namespace
	 */
1020
	if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
A
Arnaldo Carvalho de Melo 已提交
1021
		if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1022
			ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1023
			TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1024 1025
			if (rst)
				TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
L
Linus Torvalds 已提交
1026
			return;
A
Arnaldo Carvalho de Melo 已提交
1027
		}
L
Linus Torvalds 已提交
1028 1029 1030 1031 1032
	}

	kfree_skb(buff);
}

1033
static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
1034
{
1035 1036
	struct tcphdr *th = tcp_hdr(skb);
	u32 seq = 0, ack_seq = 0;
1037
	struct tcp_md5sig_key *key = NULL;
L
Linus Torvalds 已提交
1038

1039
	if (th->rst)
L
Linus Torvalds 已提交
1040 1041
		return;

1042 1043
	if (!ipv6_unicast_destination(skb))
		return;
L
Linus Torvalds 已提交
1044

1045
#ifdef CONFIG_TCP_MD5SIG
1046 1047
	if (sk)
		key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1048 1049
#endif

1050 1051 1052 1053 1054
	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
1055

1056 1057
	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
}
L
Linus Torvalds 已提交
1058

1059 1060 1061 1062
static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
			    struct tcp_md5sig_key *key)
{
	tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
L
Linus Torvalds 已提交
1063 1064 1065 1066
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
1067
	struct inet_timewait_sock *tw = inet_twsk(sk);
1068
	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
L
Linus Torvalds 已提交
1069

1070
	tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1071
			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1072
			tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
L
Linus Torvalds 已提交
1073

1074
	inet_twsk_put(tw);
L
Linus Torvalds 已提交
1075 1076
}

1077 1078
static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
				  struct request_sock *req)
L
Linus Torvalds 已提交
1079
{
1080
	tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1081
			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
L
Linus Torvalds 已提交
1082 1083 1084 1085 1086
}


static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
{
1087
	struct request_sock *req, **prev;
1088
	const struct tcphdr *th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1089 1090 1091
	struct sock *nsk;

	/* Find possible connection requests. */
1092
	req = inet6_csk_search_req(sk, &prev, th->source,
1093 1094
				   &ipv6_hdr(skb)->saddr,
				   &ipv6_hdr(skb)->daddr, inet6_iif(skb));
L
Linus Torvalds 已提交
1095 1096 1097
	if (req)
		return tcp_check_req(sk, skb, req, prev);

1098
	nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1099 1100
			&ipv6_hdr(skb)->saddr, th->source,
			&ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
1101 1102 1103 1104 1105 1106

	if (nsk) {
		if (nsk->sk_state != TCP_TIME_WAIT) {
			bh_lock_sock(nsk);
			return nsk;
		}
1107
		inet_twsk_put(inet_twsk(nsk));
L
Linus Torvalds 已提交
1108 1109 1110
		return NULL;
	}

1111
#ifdef CONFIG_SYN_COOKIES
L
Linus Torvalds 已提交
1112
	if (!th->rst && !th->syn && th->ack)
1113
		sk = cookie_v6_check(sk, skb);
L
Linus Torvalds 已提交
1114 1115 1116 1117 1118 1119 1120 1121 1122
#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)
{
1123
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
1124 1125 1126
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct tcp_options_received tmp_opt;
	struct tcp_sock *tp = tcp_sk(sk);
1127
	struct request_sock *req = NULL;
L
Linus Torvalds 已提交
1128
	__u32 isn = TCP_SKB_CB(skb)->when;
1129 1130 1131 1132 1133
#ifdef CONFIG_SYN_COOKIES
	int want_cookie = 0;
#else
#define want_cookie 0
#endif
L
Linus Torvalds 已提交
1134 1135 1136 1137 1138

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

	if (!ipv6_unicast_destination(skb))
1139
		goto drop;
L
Linus Torvalds 已提交
1140

1141
	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
L
Linus Torvalds 已提交
1142
		if (net_ratelimit())
1143 1144 1145 1146 1147 1148
			syn_flood_warning(skb);
#ifdef CONFIG_SYN_COOKIES
		if (sysctl_tcp_syncookies)
			want_cookie = 1;
		else
#endif
1149
		goto drop;
L
Linus Torvalds 已提交
1150 1151
	}

1152
	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
L
Linus Torvalds 已提交
1153 1154
		goto drop;

1155
	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
L
Linus Torvalds 已提交
1156 1157 1158
	if (req == NULL)
		goto drop;

1159 1160 1161 1162
#ifdef CONFIG_TCP_MD5SIG
	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
#endif

L
Linus Torvalds 已提交
1163 1164 1165 1166 1167 1168
	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;

	tcp_parse_options(skb, &tmp_opt, 0);

1169
	if (want_cookie && !tmp_opt.saw_tstamp)
1170 1171
		tcp_clear_options(&tmp_opt);

L
Linus Torvalds 已提交
1172 1173 1174
	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
	tcp_openreq_init(req, &tmp_opt, skb);

1175
	treq = inet6_rsk(req);
1176 1177
	ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
	ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1178 1179 1180 1181 1182
	if (!want_cookie)
		TCP_ECN_create_request(req, tcp_hdr(skb));

	if (want_cookie) {
		isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1183
		req->cookie_ts = tmp_opt.tstamp_ok;
1184 1185 1186 1187 1188 1189 1190 1191
	} else if (!isn) {
		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;
		}
		treq->iif = sk->sk_bound_dev_if;
L
Linus Torvalds 已提交
1192

1193 1194 1195 1196
		/* 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);
L
Linus Torvalds 已提交
1197

1198
		isn = tcp_v6_init_sequence(skb);
1199
	}
L
Linus Torvalds 已提交
1200

1201
	tcp_rsk(req)->snt_isn = isn;
L
Linus Torvalds 已提交
1202

1203 1204
	security_inet_conn_request(sk, skb, req);

1205
	if (tcp_v6_send_synack(sk, req))
L
Linus Torvalds 已提交
1206 1207
		goto drop;

1208 1209 1210 1211
	if (!want_cookie) {
		inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
		return 0;
	}
L
Linus Torvalds 已提交
1212 1213 1214

drop:
	if (req)
1215
		reqsk_free(req);
L
Linus Torvalds 已提交
1216 1217 1218 1219 1220

	return 0; /* don't send reset */
}

static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1221
					  struct request_sock *req,
L
Linus Torvalds 已提交
1222 1223
					  struct dst_entry *dst)
{
1224
	struct inet6_request_sock *treq;
L
Linus Torvalds 已提交
1225 1226 1227 1228 1229 1230
	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;
1231 1232 1233
#ifdef CONFIG_TCP_MD5SIG
	struct tcp_md5sig_key *key;
#endif
L
Linus Torvalds 已提交
1234 1235 1236 1237 1238 1239 1240 1241

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

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

1242
		if (newsk == NULL)
L
Linus Torvalds 已提交
1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261
			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));

		ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
			      newinet->daddr);

		ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
			      newinet->saddr);

		ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);

1262
		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
L
Linus Torvalds 已提交
1263
		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1264 1265 1266 1267
#ifdef CONFIG_TCP_MD5SIG
		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif

L
Linus Torvalds 已提交
1268 1269
		newnp->pktoptions  = NULL;
		newnp->opt	   = NULL;
1270
		newnp->mcast_oif   = inet6_iif(skb);
1271
		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
L
Linus Torvalds 已提交
1272

1273 1274 1275 1276
		/*
		 * 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
1277 1278 1279
		 */

		/* It is tricky place. Until this moment IPv4 tcp
1280
		   worked with IPv6 icsk.icsk_af_ops.
L
Linus Torvalds 已提交
1281 1282
		   Sync it now.
		 */
1283
		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
L
Linus Torvalds 已提交
1284 1285 1286 1287

		return newsk;
	}

1288
	treq = inet6_rsk(req);
L
Linus Torvalds 已提交
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299
	opt = np->opt;

	if (sk_acceptq_is_full(sk))
		goto out_overflow;

	if (dst == NULL) {
		struct in6_addr *final_p = NULL, final;
		struct flowi fl;

		memset(&fl, 0, sizeof(fl));
		fl.proto = IPPROTO_TCP;
1300
		ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
L
Linus Torvalds 已提交
1301 1302 1303 1304 1305 1306
		if (opt && opt->srcrt) {
			struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
			ipv6_addr_copy(&final, &fl.fl6_dst);
			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
			final_p = &final;
		}
1307
		ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
L
Linus Torvalds 已提交
1308
		fl.oif = sk->sk_bound_dev_if;
1309
		fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1310
		fl.fl_ip_sport = inet_rsk(req)->loc_port;
1311
		security_req_classify_flow(req, &fl);
L
Linus Torvalds 已提交
1312 1313 1314 1315 1316 1317 1318 1319 1320

		if (ip6_dst_lookup(sk, &dst, &fl))
			goto out;

		if (final_p)
			ipv6_addr_copy(&fl.fl6_dst, final_p);

		if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
			goto out;
1321
	}
L
Linus Torvalds 已提交
1322 1323 1324 1325 1326

	newsk = tcp_create_openreq_child(sk, req, skb);
	if (newsk == NULL)
		goto out;

1327 1328 1329 1330 1331
	/*
	 * 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
1332

1333
	newsk->sk_gso_type = SKB_GSO_TCPV6;
1334
	__ip6_dst_store(newsk, dst, NULL, NULL);
L
Linus Torvalds 已提交
1335 1336 1337 1338 1339 1340 1341 1342 1343 1344

	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));

1345 1346 1347 1348
	ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
	ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
	ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
	newsk->sk_bound_dev_if = treq->iif;
L
Linus Torvalds 已提交
1349

1350
	/* Now IPv6 options...
L
Linus Torvalds 已提交
1351 1352 1353 1354

	   First: no IPv4 options.
	 */
	newinet->opt = NULL;
1355
	newnp->ipv6_fl_list = NULL;
L
Linus Torvalds 已提交
1356 1357 1358 1359 1360 1361

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

	/* Clone pktoptions received with SYN */
	newnp->pktoptions = NULL;
1362 1363 1364 1365
	if (treq->pktopts != NULL) {
		newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
		kfree_skb(treq->pktopts);
		treq->pktopts = NULL;
L
Linus Torvalds 已提交
1366 1367 1368 1369
		if (newnp->pktoptions)
			skb_set_owner_r(newnp->pktoptions, newsk);
	}
	newnp->opt	  = NULL;
1370
	newnp->mcast_oif  = inet6_iif(skb);
1371
	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
L
Linus Torvalds 已提交
1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384

	/* 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);
	}

1385
	inet_csk(newsk)->icsk_ext_hdr_len = 0;
L
Linus Torvalds 已提交
1386
	if (newnp->opt)
1387 1388
		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
						     newnp->opt->opt_flen);
L
Linus Torvalds 已提交
1389

J
John Heffner 已提交
1390
	tcp_mtup_init(newsk);
L
Linus Torvalds 已提交
1391 1392 1393 1394 1395 1396
	tcp_sync_mss(newsk, dst_mtu(dst));
	newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
	tcp_initialize_rcv_mss(newsk);

	newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;

1397 1398 1399 1400 1401 1402 1403 1404
#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.
		 */
A
Arnaldo Carvalho de Melo 已提交
1405 1406
		char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
		if (newkey != NULL)
1407 1408 1409 1410 1411
			tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
					  newkey, key->keylen);
	}
#endif

1412
	__inet6_hash(newsk);
1413
	__inet_inherit_port(sk, newsk);
L
Linus Torvalds 已提交
1414 1415 1416 1417

	return newsk;

out_overflow:
1418
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
L
Linus Torvalds 已提交
1419
out:
1420
	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
L
Linus Torvalds 已提交
1421 1422 1423 1424 1425 1426
	if (opt && opt != np->opt)
		sock_kfree_s(sk, opt, opt->tot_len);
	dst_release(dst);
	return NULL;
}

1427
static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
L
Linus Torvalds 已提交
1428
{
1429
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
1430
		if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1431
				  &ipv6_hdr(skb)->daddr, skb->csum)) {
1432
			skb->ip_summed = CHECKSUM_UNNECESSARY;
L
Linus Torvalds 已提交
1433
			return 0;
1434
		}
L
Linus Torvalds 已提交
1435
	}
1436

1437
	skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1438 1439
					      &ipv6_hdr(skb)->saddr,
					      &ipv6_hdr(skb)->daddr, 0));
1440

L
Linus Torvalds 已提交
1441
	if (skb->len <= 76) {
1442
		return __skb_checksum_complete(skb);
L
Linus Torvalds 已提交
1443 1444 1445 1446 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
	}
	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);

1472 1473 1474 1475 1476
#ifdef CONFIG_TCP_MD5SIG
	if (tcp_v6_inbound_md5_hash (sk, skb))
		goto discard;
#endif

1477
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495
		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.
1496
					       --ANK (980728)
L
Linus Torvalds 已提交
1497 1498 1499 1500 1501 1502
	 */
	if (np->rxopt.all)
		opt_skb = skb_clone(skb, GFP_ATOMIC);

	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
		TCP_CHECK_TIMER(sk);
1503
		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1504 1505 1506 1507 1508 1509 1510
			goto reset;
		TCP_CHECK_TIMER(sk);
		if (opt_skb)
			goto ipv6_pktoptions;
		return 0;
	}

1511
	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
L
Linus Torvalds 已提交
1512 1513
		goto csum_err;

1514
	if (sk->sk_state == TCP_LISTEN) {
L
Linus Torvalds 已提交
1515 1516 1517 1518 1519 1520 1521 1522 1523
		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..
		 */
1524
		if(nsk != sk) {
L
Linus Torvalds 已提交
1525 1526 1527 1528 1529 1530 1531 1532 1533
			if (tcp_child_process(sk, nsk, skb))
				goto reset;
			if (opt_skb)
				__kfree_skb(opt_skb);
			return 0;
		}
	}

	TCP_CHECK_TIMER(sk);
1534
	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
L
Linus Torvalds 已提交
1535 1536 1537 1538 1539 1540 1541
		goto reset;
	TCP_CHECK_TIMER(sk);
	if (opt_skb)
		goto ipv6_pktoptions;
	return 0;

reset:
1542
	tcp_v6_send_reset(sk, skb);
L
Linus Torvalds 已提交
1543 1544 1545 1546 1547 1548
discard:
	if (opt_skb)
		__kfree_skb(opt_skb);
	kfree_skb(skb);
	return 0;
csum_err:
1549
	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563
	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))) {
1564
		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1565
			np->mcast_oif = inet6_iif(opt_skb);
1566
		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1567
			np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
L
Linus Torvalds 已提交
1568 1569 1570 1571 1572 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);
		}
	}

	if (opt_skb)
		kfree_skb(opt_skb);
	return 0;
}

1582
static int tcp_v6_rcv(struct sk_buff *skb)
L
Linus Torvalds 已提交
1583
{
1584
	struct tcphdr *th;
L
Linus Torvalds 已提交
1585 1586
	struct sock *sk;
	int ret;
1587
	struct net *net = dev_net(skb->dev);
L
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1588 1589 1590 1591 1592 1593 1594

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

	/*
	 *	Count it even if it's bad.
	 */
1595
	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
L
Linus Torvalds 已提交
1596 1597 1598 1599

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

1600
	th = tcp_hdr(skb);
L
Linus Torvalds 已提交
1601 1602 1603 1604 1605 1606

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

1607
	if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
L
Linus Torvalds 已提交
1608 1609
		goto bad_packet;

1610
	th = tcp_hdr(skb);
L
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1611 1612 1613 1614 1615
	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;
1616
	TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
L
Linus Torvalds 已提交
1617 1618
	TCP_SKB_CB(skb)->sacked = 0;

1619
	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
L
Linus Torvalds 已提交
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629
	if (!sk)
		goto no_tcp_socket;

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

	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_and_relse;

1630
	if (sk_filter(sk, skb))
L
Linus Torvalds 已提交
1631 1632 1633 1634
		goto discard_and_relse;

	skb->dev = NULL;

1635
	bh_lock_sock_nested(sk);
L
Linus Torvalds 已提交
1636 1637
	ret = 0;
	if (!sock_owned_by_user(sk)) {
C
Chris Leech 已提交
1638
#ifdef CONFIG_NET_DMA
1639
		struct tcp_sock *tp = tcp_sk(sk);
1640 1641
		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
			tp->ucopy.dma_chan = get_softnet_dma();
1642 1643 1644
		if (tp->ucopy.dma_chan)
			ret = tcp_v6_do_rcv(sk, skb);
		else
C
Chris Leech 已提交
1645 1646 1647 1648 1649
#endif
		{
			if (!tcp_prequeue(sk, skb))
				ret = tcp_v6_do_rcv(sk, skb);
		}
L
Linus Torvalds 已提交
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662
	} else
		sk_add_backlog(sk, skb);
	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:
1663
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
L
Linus Torvalds 已提交
1664
	} else {
1665
		tcp_v6_send_reset(NULL, skb);
L
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1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682
	}

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)) {
1683
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1684 1685 1686 1687
		goto discard_it;
	}

	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1688
		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1689
		inet_twsk_put(inet_twsk(sk));
L
Linus Torvalds 已提交
1690 1691 1692
		goto discard_it;
	}

1693
	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
L
Linus Torvalds 已提交
1694 1695 1696 1697
	case TCP_TW_SYN:
	{
		struct sock *sk2;

1698
		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1699
					    &ipv6_hdr(skb)->daddr,
1700
					    ntohs(th->dest), inet6_iif(skb));
L
Linus Torvalds 已提交
1701
		if (sk2 != NULL) {
1702 1703 1704
			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
1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725
			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;
}

static int tcp_v6_remember_stamp(struct sock *sk)
{
	/* Alas, not yet... */
	return 0;
}

1726
static struct inet_connection_sock_af_ops ipv6_specific = {
1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737
	.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,
	.remember_stamp	   = tcp_v6_remember_stamp,
	.net_header_len	   = sizeof(struct ipv6hdr),
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1738
	.bind_conflict	   = inet6_csk_bind_conflict,
1739
#ifdef CONFIG_COMPAT
1740 1741
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1742
#endif
L
Linus Torvalds 已提交
1743 1744
};

1745
#ifdef CONFIG_TCP_MD5SIG
1746
static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1747
	.md5_lookup	=	tcp_v6_md5_lookup,
1748
	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
1749 1750 1751
	.md5_add	=	tcp_v6_md5_add_func,
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1752
#endif
1753

L
Linus Torvalds 已提交
1754 1755 1756 1757
/*
 *	TCP over IPv4 via INET6 API
 */

1758
static struct inet_connection_sock_af_ops ipv6_mapped = {
1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769
	.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,
	.remember_stamp	   = tcp_v4_remember_stamp,
	.net_header_len	   = sizeof(struct iphdr),
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1770
	.bind_conflict	   = inet6_csk_bind_conflict,
1771
#ifdef CONFIG_COMPAT
1772 1773
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
1774
#endif
L
Linus Torvalds 已提交
1775 1776
};

1777
#ifdef CONFIG_TCP_MD5SIG
1778
static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1779
	.md5_lookup	=	tcp_v4_md5_lookup,
1780
	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
1781 1782 1783
	.md5_add	=	tcp_v6_md5_add_func,
	.md5_parse	=	tcp_v6_parse_md5_keys,
};
1784
#endif
1785

L
Linus Torvalds 已提交
1786 1787 1788 1789 1790
/* 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)
{
1791
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1792 1793 1794 1795 1796 1797
	struct tcp_sock *tp = tcp_sk(sk);

	skb_queue_head_init(&tp->out_of_order_queue);
	tcp_init_xmit_timers(sk);
	tcp_prequeue_init(tp);

1798
	icsk->icsk_rto = TCP_TIMEOUT_INIT;
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
	tp->mdev = TCP_TIMEOUT_INIT;

	/* So many TCP implementations out there (incorrectly) count the
	 * initial SYN frame in their delayed-ACK and congestion control
	 * algorithms that we must have the following bandaid to talk
	 * efficiently to them.  -DaveM
	 */
	tp->snd_cwnd = 2;

	/* See draft-stevens-tcpca-spec-01 for discussion of the
	 * initialization of these values.
	 */
	tp->snd_ssthresh = 0x7fffffff;
	tp->snd_cwnd_clamp = ~0;
1813
	tp->mss_cache = 536;
L
Linus Torvalds 已提交
1814 1815 1816 1817 1818

	tp->reordering = sysctl_tcp_reordering;

	sk->sk_state = TCP_CLOSE;

1819
	icsk->icsk_af_ops = &ipv6_specific;
1820
	icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1821
	icsk->icsk_sync_mss = tcp_sync_mss;
L
Linus Torvalds 已提交
1822 1823 1824
	sk->sk_write_space = sk_stream_write_space;
	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);

1825 1826 1827 1828
#ifdef CONFIG_TCP_MD5SIG
	tp->af_specific = &tcp_sock_ipv6_specific;
#endif

L
Linus Torvalds 已提交
1829 1830 1831 1832 1833 1834 1835 1836
	sk->sk_sndbuf = sysctl_tcp_wmem[1];
	sk->sk_rcvbuf = sysctl_tcp_rmem[1];

	atomic_inc(&tcp_sockets_allocated);

	return 0;
}

1837
static void tcp_v6_destroy_sock(struct sock *sk)
L
Linus Torvalds 已提交
1838
{
1839 1840 1841 1842 1843
#ifdef CONFIG_TCP_MD5SIG
	/* Clean up the MD5 key list */
	if (tcp_sk(sk)->md5sig_info)
		tcp_v6_clear_md5_list(sk);
#endif
L
Linus Torvalds 已提交
1844
	tcp_v4_destroy_sock(sk);
1845
	inet6_destroy_sock(sk);
L
Linus Torvalds 已提交
1846 1847
}

1848
#ifdef CONFIG_PROC_FS
L
Linus Torvalds 已提交
1849
/* Proc filesystem TCPv6 sock list dumping. */
1850
static void get_openreq6(struct seq_file *seq,
1851
			 struct sock *sk, struct request_sock *req, int i, int uid)
L
Linus Torvalds 已提交
1852 1853
{
	int ttd = req->expires - jiffies;
1854 1855
	struct in6_addr *src = &inet6_rsk(req)->loc_addr;
	struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
L
Linus Torvalds 已提交
1856 1857 1858 1859 1860 1861 1862 1863 1864 1865

	if (ttd < 0)
		ttd = 0;

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
		   i,
		   src->s6_addr32[0], src->s6_addr32[1],
		   src->s6_addr32[2], src->s6_addr32[3],
1866
		   ntohs(inet_rsk(req)->loc_port),
L
Linus Torvalds 已提交
1867 1868
		   dest->s6_addr32[0], dest->s6_addr32[1],
		   dest->s6_addr32[2], dest->s6_addr32[3],
1869
		   ntohs(inet_rsk(req)->rmt_port),
L
Linus Torvalds 已提交
1870 1871
		   TCP_SYN_RECV,
		   0,0, /* could print option size, but that is af dependent. */
1872 1873
		   1,   /* timers active (only the expire timer) */
		   jiffies_to_clock_t(ttd),
L
Linus Torvalds 已提交
1874 1875
		   req->retrans,
		   uid,
1876
		   0,  /* non standard timer */
L
Linus Torvalds 已提交
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888
		   0, /* open_requests have no inode */
		   0, req);
}

static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
{
	struct in6_addr *dest, *src;
	__u16 destp, srcp;
	int timer_active;
	unsigned long timer_expires;
	struct inet_sock *inet = inet_sk(sp);
	struct tcp_sock *tp = tcp_sk(sp);
1889
	const struct inet_connection_sock *icsk = inet_csk(sp);
L
Linus Torvalds 已提交
1890 1891 1892 1893 1894 1895
	struct ipv6_pinfo *np = inet6_sk(sp);

	dest  = &np->daddr;
	src   = &np->rcv_saddr;
	destp = ntohs(inet->dport);
	srcp  = ntohs(inet->sport);
1896 1897

	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
L
Linus Torvalds 已提交
1898
		timer_active	= 1;
1899 1900
		timer_expires	= icsk->icsk_timeout;
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
L
Linus Torvalds 已提交
1901
		timer_active	= 4;
1902
		timer_expires	= icsk->icsk_timeout;
L
Linus Torvalds 已提交
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
	} 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 "
1913
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %lu %lu %u %u %d\n",
L
Linus Torvalds 已提交
1914 1915 1916 1917 1918
		   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,
1919
		   sp->sk_state,
1920 1921
		   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
1922 1923
		   timer_active,
		   jiffies_to_clock_t(timer_expires - jiffies),
1924
		   icsk->icsk_retransmits,
L
Linus Torvalds 已提交
1925
		   sock_i_uid(sp),
1926
		   icsk->icsk_probes_out,
L
Linus Torvalds 已提交
1927 1928
		   sock_i_ino(sp),
		   atomic_read(&sp->sk_refcnt), sp,
1929 1930
		   jiffies_to_clock_t(icsk->icsk_rto),
		   jiffies_to_clock_t(icsk->icsk_ack.ato),
1931
		   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
L
Linus Torvalds 已提交
1932 1933 1934 1935
		   tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
		   );
}

1936
static void get_timewait6_sock(struct seq_file *seq,
1937
			       struct inet_timewait_sock *tw, int i)
L
Linus Torvalds 已提交
1938 1939 1940
{
	struct in6_addr *dest, *src;
	__u16 destp, srcp;
1941
	struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
L
Linus Torvalds 已提交
1942 1943 1944 1945 1946
	int ttd = tw->tw_ttd - jiffies;

	if (ttd < 0)
		ttd = 0;

1947 1948
	dest = &tw6->tw_v6_daddr;
	src  = &tw6->tw_v6_rcv_saddr;
L
Linus Torvalds 已提交
1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 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
	destp = ntohs(tw->tw_dport);
	srcp  = ntohs(tw->tw_sport);

	seq_printf(seq,
		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
		   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;
}

static struct tcp_seq_afinfo tcp6_seq_afinfo = {
	.name		= "tcp6",
	.family		= AF_INET6,
1999 2000 2001
	.seq_fops	= {
		.owner		= THIS_MODULE,
	},
2002 2003 2004
	.seq_ops	= {
		.show		= tcp6_seq_show,
	},
L
Linus Torvalds 已提交
2005 2006
};

2007
int tcp6_proc_init(struct net *net)
L
Linus Torvalds 已提交
2008
{
2009
	return tcp_proc_register(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
2010 2011
}

2012
void tcp6_proc_exit(struct net *net)
L
Linus Torvalds 已提交
2013
{
2014
	tcp_proc_unregister(net, &tcp6_seq_afinfo);
L
Linus Torvalds 已提交
2015 2016 2017 2018 2019 2020 2021 2022 2023
}
#endif

struct proto tcpv6_prot = {
	.name			= "TCPv6",
	.owner			= THIS_MODULE,
	.close			= tcp_close,
	.connect		= tcp_v6_connect,
	.disconnect		= tcp_disconnect,
2024
	.accept			= inet_csk_accept,
L
Linus Torvalds 已提交
2025 2026 2027 2028 2029 2030 2031 2032 2033
	.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,
	.backlog_rcv		= tcp_v6_do_rcv,
	.hash			= tcp_v6_hash,
2034 2035
	.unhash			= inet_unhash,
	.get_port		= inet_csk_get_port,
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	.enter_memory_pressure	= tcp_enter_memory_pressure,
	.sockets_allocated	= &tcp_sockets_allocated,
	.memory_allocated	= &tcp_memory_allocated,
	.memory_pressure	= &tcp_memory_pressure,
2040
	.orphan_count		= &tcp_orphan_count,
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	.sysctl_mem		= sysctl_tcp_mem,
	.sysctl_wmem		= sysctl_tcp_wmem,
	.sysctl_rmem		= sysctl_tcp_rmem,
	.max_header		= MAX_TCP_HEADER,
	.obj_size		= sizeof(struct tcp6_sock),
2046
	.slab_flags		= SLAB_DESTROY_BY_RCU,
2047
	.twsk_prot		= &tcp6_timewait_sock_ops,
2048
	.rsk_prot		= &tcp6_request_sock_ops,
2049
	.h.hashinfo		= &tcp_hashinfo,
2050 2051 2052 2053
#ifdef CONFIG_COMPAT
	.compat_setsockopt	= compat_tcp_setsockopt,
	.compat_getsockopt	= compat_tcp_getsockopt,
#endif
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};

static struct inet6_protocol tcpv6_protocol = {
	.handler	=	tcp_v6_rcv,
	.err_handler	=	tcp_v6_err,
2059
	.gso_send_check	=	tcp_v6_gso_send_check,
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Herbert Xu 已提交
2060
	.gso_segment	=	tcp_tso_segment,
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	.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,
	.capability	=	-1,
	.no_check	=	0,
2071 2072
	.flags		=	INET_PROTOSW_PERMANENT |
				INET_PROTOSW_ICSK,
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};

2075 2076
static int tcpv6_net_init(struct net *net)
{
2077 2078
	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
				    SOCK_RAW, IPPROTO_TCP, net);
2079 2080 2081 2082
}

static void tcpv6_net_exit(struct net *net)
{
2083
	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2084
	inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET6);
2085 2086 2087 2088 2089 2090 2091
}

static struct pernet_operations tcpv6_net_ops = {
	.init = tcpv6_net_init,
	.exit = tcpv6_net_exit,
};

2092
int __init tcpv6_init(void)
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{
2094 2095 2096 2097 2098 2099
	int ret;

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

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	/* register inet6 protocol */
2101 2102 2103 2104
	ret = inet6_register_protosw(&tcpv6_protosw);
	if (ret)
		goto out_tcpv6_protocol;

2105
	ret = register_pernet_subsys(&tcpv6_net_ops);
2106 2107 2108 2109
	if (ret)
		goto out_tcpv6_protosw;
out:
	return ret;
2110

2111 2112 2113 2114 2115 2116 2117
out_tcpv6_protocol:
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
out_tcpv6_protosw:
	inet6_unregister_protosw(&tcpv6_protosw);
	goto out;
}

2118
void tcpv6_exit(void)
2119
{
2120
	unregister_pernet_subsys(&tcpv6_net_ops);
2121 2122
	inet6_unregister_protosw(&tcpv6_protosw);
	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
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}