Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 2196 insertions, 0 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
new file mode 100644
index 00000000..98256cf7
--- /dev/null
+++ b/net/ipv6/tcp_ipv6.c
@@ -0,0 +1,2196 @@
+/*
+ *	TCP over IPv6
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *
+ *	Based on:
+ *	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/bottom_half.h>
+#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/slab.h>
+
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+
+#include <net/tcp.h>
+#include <net/ndisc.h>
+#include <net/inet6_hashtables.h>
+#include <net/inet6_connection_sock.h>
+#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>
+#include <net/timewait_sock.h>
+#include <net/netdma.h>
+#include <net/inet_common.h>
+#include <net/secure_seq.h>
+#include <net/tcp_memcontrol.h>
+
+#include <asm/uaccess.h>
+
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+
+static void	tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
+static void	tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
+				      struct request_sock *req);
+
+static int	tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
+static void	__tcp_v6_send_check(struct sk_buff *skb,
+				    const struct in6_addr *saddr,
+				    const struct in6_addr *daddr);
+
+static const struct inet_connection_sock_af_ops ipv6_mapped;
+static const struct inet_connection_sock_af_ops ipv6_specific;
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
+static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
+#else
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
+						   const struct in6_addr *addr)
+{
+	return NULL;
+}
+#endif
+
+static void tcp_v6_hash(struct sock *sk)
+{
+	if (sk->sk_state != TCP_CLOSE) {
+		if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
+			tcp_prot.hash(sk);
+			return;
+		}
+		local_bh_disable();
+		__inet6_hash(sk, NULL);
+		local_bh_enable();
+	}
+}
+
+static __inline__ __sum16 tcp_v6_check(int len,
+				   const struct in6_addr *saddr,
+				   const struct in6_addr *daddr,
+				   __wsum base)
+{
+	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
+}
+
+static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
+{
+	return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
+					    ipv6_hdr(skb)->saddr.s6_addr32,
+					    tcp_hdr(skb)->dest,
+					    tcp_hdr(skb)->source);
+}
+
+static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
+			  int addr_len)
+{
+	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
+	struct inet_sock *inet = inet_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct in6_addr *saddr = NULL, *final_p, final;
+	struct rt6_info *rt;
+	struct flowi6 fl6;
+	struct dst_entry *dst;
+	int addr_type;
+	int err;
+
+	if (addr_len < SIN6_LEN_RFC2133)
+		return -EINVAL;
+
+	if (usin->sin6_family != AF_INET6)
+		return -EAFNOSUPPORT;
+
+	memset(&fl6, 0, sizeof(fl6));
+
+	if (np->sndflow) {
+		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
+		IP6_ECN_flow_init(fl6.flowlabel);
+		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
+			struct ip6_flowlabel *flowlabel;
+			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
+			if (flowlabel == NULL)
+				return -EINVAL;
+			usin->sin6_addr = flowlabel->dst;
+			fl6_sock_release(flowlabel);
+		}
+	}
+
+	/*
+	 *	connect() to INADDR_ANY means loopback (BSD'ism).
+	 */
+
+	if(ipv6_addr_any(&usin->sin6_addr))
+		usin->sin6_addr.s6_addr[15] = 0x1;
+
+	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;
+	}
+
+	np->daddr = usin->sin6_addr;
+	np->flow_label = fl6.flowlabel;
+
+	/*
+	 *	TCP over IPv4
+	 */
+
+	if (addr_type == IPV6_ADDR_MAPPED) {
+		u32 exthdrlen = icsk->icsk_ext_hdr_len;
+		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];
+
+		icsk->icsk_af_ops = &ipv6_mapped;
+		sk->sk_backlog_rcv = tcp_v4_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+		tp->af_specific = &tcp_sock_ipv6_mapped_specific;
+#endif
+
+		err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
+
+		if (err) {
+			icsk->icsk_ext_hdr_len = exthdrlen;
+			icsk->icsk_af_ops = &ipv6_specific;
+			sk->sk_backlog_rcv = tcp_v6_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+			tp->af_specific = &tcp_sock_ipv6_specific;
+#endif
+			goto failure;
+		} else {
+			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
+			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
+					       &np->rcv_saddr);
+		}
+
+		return err;
+	}
+
+	if (!ipv6_addr_any(&np->rcv_saddr))
+		saddr = &np->rcv_saddr;
+
+	fl6.flowi6_proto = IPPROTO_TCP;
+	fl6.daddr = np->daddr;
+	fl6.saddr = saddr ? *saddr : np->saddr;
+	fl6.flowi6_oif = sk->sk_bound_dev_if;
+	fl6.flowi6_mark = sk->sk_mark;
+	fl6.fl6_dport = usin->sin6_port;
+	fl6.fl6_sport = inet->inet_sport;
+
+	final_p = fl6_update_dst(&fl6, np->opt, &final);
+
+	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
+
+	dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
+	if (IS_ERR(dst)) {
+		err = PTR_ERR(dst);
+		goto failure;
+	}
+
+	if (saddr == NULL) {
+		saddr = &fl6.saddr;
+		np->rcv_saddr = *saddr;
+	}
+
+	/* set the source address */
+	np->saddr = *saddr;
+	inet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+	sk->sk_gso_type = SKB_GSO_TCPV6;
+	__ip6_dst_store(sk, dst, NULL, NULL);
+
+	rt = (struct rt6_info *) dst;
+	if (tcp_death_row.sysctl_tw_recycle &&
+	    !tp->rx_opt.ts_recent_stamp &&
+	    ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
+		struct inet_peer *peer = rt6_get_peer(rt);
+		/*
+		 * VJ's idea. We save last timestamp seen from
+		 * the destination in peer table, when entering state
+		 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
+		 * when trying new connection.
+		 */
+		if (peer) {
+			inet_peer_refcheck(peer);
+			if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
+				tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
+				tp->rx_opt.ts_recent = peer->tcp_ts;
+			}
+		}
+	}
+
+	icsk->icsk_ext_hdr_len = 0;
+	if (np->opt)
+		icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
+					  np->opt->opt_nflen);
+
+	tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
+
+	inet->inet_dport = usin->sin6_port;
+
+	tcp_set_state(sk, TCP_SYN_SENT);
+	err = inet6_hash_connect(&tcp_death_row, sk);
+	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->inet_sport,
+							     inet->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->inet_dport = 0;
+	sk->sk_route_caps = 0;
+	return err;
+}
+
+static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+		u8 type, u8 code, int offset, __be32 info)
+{
+	const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
+	const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
+	struct ipv6_pinfo *np;
+	struct sock *sk;
+	int err;
+	struct tcp_sock *tp;
+	__u32 seq;
+	struct net *net = dev_net(skb->dev);
+
+	sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
+			th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
+
+	if (sk == NULL) {
+		ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
+				   ICMP6_MIB_INERRORS);
+		return;
+	}
+
+	if (sk->sk_state == TCP_TIME_WAIT) {
+		inet_twsk_put(inet_twsk(sk));
+		return;
+	}
+
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk))
+		NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
+
+	if (sk->sk_state == TCP_CLOSE)
+		goto out;
+
+	if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
+		NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
+		goto out;
+	}
+
+	tp = tcp_sk(sk);
+	seq = ntohl(th->seq);
+	if (sk->sk_state != TCP_LISTEN &&
+	    !between(seq, tp->snd_una, tp->snd_nxt)) {
+		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+		goto out;
+	}
+
+	np = inet6_sk(sk);
+
+	if (type == ICMPV6_PKT_TOOBIG) {
+		struct dst_entry *dst;
+
+		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 flowi6 fl6;
+
+			/* BUGGG_FUTURE: Again, it is not clear how
+			   to handle rthdr case. Ignore this complexity
+			   for now.
+			 */
+			memset(&fl6, 0, sizeof(fl6));
+			fl6.flowi6_proto = IPPROTO_TCP;
+			fl6.daddr = np->daddr;
+			fl6.saddr = np->saddr;
+			fl6.flowi6_oif = sk->sk_bound_dev_if;
+			fl6.flowi6_mark = sk->sk_mark;
+			fl6.fl6_dport = inet->inet_dport;
+			fl6.fl6_sport = inet->inet_sport;
+			security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
+
+			dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
+			if (IS_ERR(dst)) {
+				sk->sk_err_soft = -PTR_ERR(dst);
+				goto out;
+			}
+
+		} else
+			dst_hold(dst);
+
+		if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
+			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);
+
+	/* Might be for an request_sock */
+	switch (sk->sk_state) {
+		struct request_sock *req, **prev;
+	case TCP_LISTEN:
+		if (sock_owned_by_user(sk))
+			goto out;
+
+		req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
+					   &hdr->saddr, inet6_iif(skb));
+		if (!req)
+			goto out;
+
+		/* ICMPs are not backlogged, hence we cannot get
+		 * an established socket here.
+		 */
+		WARN_ON(req->sk != NULL);
+
+		if (seq != tcp_rsk(req)->snt_isn) {
+			NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+			goto out;
+		}
+
+		inet_csk_reqsk_queue_drop(sk, req, prev);
+		goto out;
+
+	case TCP_SYN_SENT:
+	case TCP_SYN_RECV:  /* Cannot happen.
+			       It can, it SYNs are crossed. --ANK */
+		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);
+}
+
+
+static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
+			      struct request_values *rvp)
+{
+	struct inet6_request_sock *treq = inet6_rsk(req);
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct sk_buff * skb;
+	struct ipv6_txoptions *opt = NULL;
+	struct in6_addr * final_p, final;
+	struct flowi6 fl6;
+	struct dst_entry *dst;
+	int err;
+
+	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_proto = IPPROTO_TCP;
+	fl6.daddr = treq->rmt_addr;
+	fl6.saddr = treq->loc_addr;
+	fl6.flowlabel = 0;
+	fl6.flowi6_oif = treq->iif;
+	fl6.flowi6_mark = sk->sk_mark;
+	fl6.fl6_dport = inet_rsk(req)->rmt_port;
+	fl6.fl6_sport = inet_rsk(req)->loc_port;
+	security_req_classify_flow(req, flowi6_to_flowi(&fl6));
+
+	opt = np->opt;
+	final_p = fl6_update_dst(&fl6, opt, &final);
+
+	dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
+	if (IS_ERR(dst)) {
+		err = PTR_ERR(dst);
+		dst = NULL;
+		goto done;
+	}
+	skb = tcp_make_synack(sk, dst, req, rvp);
+	err = -ENOMEM;
+	if (skb) {
+		__tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
+
+		fl6.daddr = treq->rmt_addr;
+		err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
+		err = net_xmit_eval(err);
+	}
+
+done:
+	if (opt && opt != np->opt)
+		sock_kfree_s(sk, opt, opt->tot_len);
+	dst_release(dst);
+	return err;
+}
+
+static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
+			     struct request_values *rvp)
+{
+	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
+	return tcp_v6_send_synack(sk, req, rvp);
+}
+
+static void tcp_v6_reqsk_destructor(struct request_sock *req)
+{
+	kfree_skb(inet6_rsk(req)->pktopts);
+}
+
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
+						   const struct in6_addr *addr)
+{
+	return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
+}
+
+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) {
+		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+			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);
+	}
+
+	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
+		return -EINVAL;
+
+	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);
+
+	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
+			      AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
+}
+
+static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
+					const struct in6_addr *daddr,
+					const struct in6_addr *saddr, int nbytes)
+{
+	struct tcp6_pseudohdr *bp;
+	struct scatterlist sg;
+
+	bp = &hp->md5_blk.ip6;
+	/* 1. TCP pseudo-header (RFC2460) */
+	bp->saddr = *saddr;
+	bp->daddr = *daddr;
+	bp->protocol = cpu_to_be32(IPPROTO_TCP);
+	bp->len = cpu_to_be32(nbytes);
+
+	sg_init_one(&sg, bp, sizeof(*bp));
+	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
+}
+
+static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
+			       const struct in6_addr *daddr, struct in6_addr *saddr,
+			       const 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))
+		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;
+}
+
+static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
+			       const struct sock *sk,
+			       const struct request_sock *req,
+			       const struct sk_buff *skb)
+{
+	const struct in6_addr *saddr, *daddr;
+	struct tcp_md5sig_pool *hp;
+	struct hash_desc *desc;
+	const struct tcphdr *th = tcp_hdr(skb);
+
+	if (sk) {
+		saddr = &inet6_sk(sk)->saddr;
+		daddr = &inet6_sk(sk)->daddr;
+	} else if (req) {
+		saddr = &inet6_rsk(req)->loc_addr;
+		daddr = &inet6_rsk(req)->rmt_addr;
+	} else {
+		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+		saddr = &ip6h->saddr;
+		daddr = &ip6h->daddr;
+	}
+
+	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;
+}
+
+static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
+{
+	const __u8 *hash_location = NULL;
+	struct tcp_md5sig_key *hash_expected;
+	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	const struct tcphdr *th = tcp_hdr(skb);
+	int genhash;
+	u8 newhash[16];
+
+	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
+	hash_location = tcp_parse_md5sig_option(th);
+
+	/* 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);
+		return 1;
+	}
+
+	if (!hash_expected && hash_location) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+		return 1;
+	}
+
+	/* check the signature */
+	genhash = tcp_v6_md5_hash_skb(newhash,
+				      hash_expected,
+				      NULL, NULL, skb);
+
+	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+		if (net_ratelimit()) {
+			printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
+			       genhash ? "failed" : "mismatch",
+			       &ip6h->saddr, ntohs(th->source),
+			       &ip6h->daddr, ntohs(th->dest));
+		}
+		return 1;
+	}
+	return 0;
+}
+#endif
+
+struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
+	.family		=	AF_INET6,
+	.obj_size	=	sizeof(struct tcp6_request_sock),
+	.rtx_syn_ack	=	tcp_v6_rtx_synack,
+	.send_ack	=	tcp_v6_reqsk_send_ack,
+	.destructor	=	tcp_v6_reqsk_destructor,
+	.send_reset	=	tcp_v6_send_reset,
+	.syn_ack_timeout = 	tcp_syn_ack_timeout,
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
+	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
+	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
+};
+#endif
+
+static void __tcp_v6_send_check(struct sk_buff *skb,
+				const struct in6_addr *saddr, const struct in6_addr *daddr)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
+		skb->csum_start = skb_transport_header(skb) - skb->head;
+		skb->csum_offset = offsetof(struct tcphdr, check);
+	} else {
+		th->check = tcp_v6_check(skb->len, saddr, daddr,
+					 csum_partial(th, th->doff << 2,
+						      skb->csum));
+	}
+}
+
+static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
+{
+	struct ipv6_pinfo *np = inet6_sk(sk);
+
+	__tcp_v6_send_check(skb, &np->saddr, &np->daddr);
+}
+
+static int tcp_v6_gso_send_check(struct sk_buff *skb)
+{
+	const struct ipv6hdr *ipv6h;
+	struct tcphdr *th;
+
+	if (!pskb_may_pull(skb, sizeof(*th)))
+		return -EINVAL;
+
+	ipv6h = ipv6_hdr(skb);
+	th = tcp_hdr(skb);
+
+	th->check = 0;
+	skb->ip_summed = CHECKSUM_PARTIAL;
+	__tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
+	return 0;
+}
+
+static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
+					 struct sk_buff *skb)
+{
+	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
+				  skb->csum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			break;
+		}
+
+		/* fall through */
+	case CHECKSUM_NONE:
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+	return tcp_gro_receive(head, skb);
+}
+
+static int tcp6_gro_complete(struct sk_buff *skb)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct tcphdr *th = tcp_hdr(skb);
+
+	th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
+				  &iph->saddr, &iph->daddr, 0);
+	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+
+	return tcp_gro_complete(skb);
+}
+
+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, u8 tclass)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	struct tcphdr *t1;
+	struct sk_buff *buff;
+	struct flowi6 fl6;
+	struct net *net = dev_net(skb_dst(skb)->dev);
+	struct sock *ctl_sk = net->ipv6.tcp_sk;
+	unsigned int tot_len = sizeof(struct tcphdr);
+	struct dst_entry *dst;
+	__be32 *topt;
+
+	if (ts)
+		tot_len += TCPOLEN_TSTAMP_ALIGNED;
+#ifdef CONFIG_TCP_MD5SIG
+	if (key)
+		tot_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
+	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
+			 GFP_ATOMIC);
+	if (buff == NULL)
+		return;
+
+	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
+
+	t1 = (struct tcphdr *) skb_push(buff, tot_len);
+	skb_reset_transport_header(buff);
+
+	/* Swap the send and the receive. */
+	memset(t1, 0, sizeof(*t1));
+	t1->dest = th->source;
+	t1->source = th->dest;
+	t1->doff = tot_len / 4;
+	t1->seq = htonl(seq);
+	t1->ack_seq = htonl(ack);
+	t1->ack = !rst || !th->ack;
+	t1->rst = rst;
+	t1->window = htons(win);
+
+	topt = (__be32 *)(t1 + 1);
+
+	if (ts) {
+		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
+		*topt++ = htonl(tcp_time_stamp);
+		*topt++ = htonl(ts);
+	}
+
+#ifdef CONFIG_TCP_MD5SIG
+	if (key) {
+		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
+		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
+				    &ipv6_hdr(skb)->saddr,
+				    &ipv6_hdr(skb)->daddr, t1);
+	}
+#endif
+
+	memset(&fl6, 0, sizeof(fl6));
+	fl6.daddr = ipv6_hdr(skb)->saddr;
+	fl6.saddr = ipv6_hdr(skb)->daddr;
+
+	buff->ip_summed = CHECKSUM_PARTIAL;
+	buff->csum = 0;
+
+	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
+
+	fl6.flowi6_proto = IPPROTO_TCP;
+	fl6.flowi6_oif = inet6_iif(skb);
+	fl6.fl6_dport = t1->dest;
+	fl6.fl6_sport = t1->source;
+	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
+
+	/* Pass a socket to ip6_dst_lookup either it is for RST
+	 * Underlying function will use this to retrieve the network
+	 * namespace
+	 */
+	dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
+	if (!IS_ERR(dst)) {
+		skb_dst_set(buff, dst);
+		ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
+		TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
+		if (rst)
+			TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
+		return;
+	}
+
+	kfree_skb(buff);
+}
+
+static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	u32 seq = 0, ack_seq = 0;
+	struct tcp_md5sig_key *key = NULL;
+#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
+
+	if (th->rst)
+		return;
+
+	if (!ipv6_unicast_destination(skb))
+		return;
+
+#ifdef CONFIG_TCP_MD5SIG
+	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;
+	}
+#endif
+
+	if (th->ack)
+		seq = ntohl(th->ack_seq);
+	else
+		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
+			  (th->doff << 2);
+
+	tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
+
+#ifdef CONFIG_TCP_MD5SIG
+release_sk1:
+	if (sk1) {
+		rcu_read_unlock();
+		sock_put(sk1);
+	}
+#endif
+}
+
+static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
+			    struct tcp_md5sig_key *key, u8 tclass)
+{
+	tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
+}
+
+static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
+{
+	struct inet_timewait_sock *tw = inet_twsk(sk);
+	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+
+	tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
+			tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
+			tw->tw_tclass);
+
+	inet_twsk_put(tw);
+}
+
+static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
+				  struct request_sock *req)
+{
+	tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
+			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
+}
+
+
+static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
+{
+	struct request_sock *req, **prev;
+	const struct tcphdr *th = tcp_hdr(skb);
+	struct sock *nsk;
+
+	/* Find possible connection requests. */
+	req = inet6_csk_search_req(sk, &prev, th->source,
+				   &ipv6_hdr(skb)->saddr,
+				   &ipv6_hdr(skb)->daddr, inet6_iif(skb));
+	if (req)
+		return tcp_check_req(sk, skb, req, prev);
+
+	nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
+			&ipv6_hdr(skb)->saddr, th->source,
+			&ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
+
+	if (nsk) {
+		if (nsk->sk_state != TCP_TIME_WAIT) {
+			bh_lock_sock(nsk);
+			return nsk;
+		}
+		inet_twsk_put(inet_twsk(nsk));
+		return NULL;
+	}
+
+#ifdef CONFIG_SYN_COOKIES
+	if (!th->syn)
+		sk = cookie_v6_check(sk, skb);
+#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)
+{
+	struct tcp_extend_values tmp_ext;
+	struct tcp_options_received tmp_opt;
+	const u8 *hash_location;
+	struct request_sock *req;
+	struct inet6_request_sock *treq;
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	__u32 isn = TCP_SKB_CB(skb)->when;
+	struct dst_entry *dst = NULL;
+	int want_cookie = 0;
+
+	if (skb->protocol == htons(ETH_P_IP))
+		return tcp_v4_conn_request(sk, skb);
+
+	if (!ipv6_unicast_destination(skb))
+		goto drop;
+
+	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
+		want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
+		if (!want_cookie)
+			goto drop;
+	}
+
+	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
+		goto drop;
+
+	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
+	if (req == NULL)
+		goto drop;
+
+#ifdef CONFIG_TCP_MD5SIG
+	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
+#endif
+
+	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, &hash_location, 0);
+
+	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 */
+		d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+		d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+		*mess++ ^= *d++;
+
+		/* plus variable length Initiator Cookie */
+		c = (u8 *)mess;
+		while (l-- > 0)
+			*c++ ^= *hash_location++;
+
+		want_cookie = 0;	/* not our kind of cookie */
+		tmp_ext.cookie_out_never = 0; /* false */
+		tmp_ext.cookie_plus = tmp_opt.cookie_plus;
+	} else if (!tp->rx_opt.cookie_in_always) {
+		/* redundant indications, but ensure initialization. */
+		tmp_ext.cookie_out_never = 1; /* true */
+		tmp_ext.cookie_plus = 0;
+	} else {
+		goto drop_and_free;
+	}
+	tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
+
+	if (want_cookie && !tmp_opt.saw_tstamp)
+		tcp_clear_options(&tmp_opt);
+
+	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
+	tcp_openreq_init(req, &tmp_opt, skb);
+
+	treq = inet6_rsk(req);
+	treq->rmt_addr = ipv6_hdr(skb)->saddr;
+	treq->loc_addr = ipv6_hdr(skb)->daddr;
+	if (!want_cookie || tmp_opt.tstamp_ok)
+		TCP_ECN_create_request(req, tcp_hdr(skb));
+
+	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);
+
+	if (!isn) {
+		struct inet_peer *peer = NULL;
+
+		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;
+		}
+
+		if (want_cookie) {
+			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
+			req->cookie_ts = tmp_opt.tstamp_ok;
+			goto have_isn;
+		}
+
+		/* VJ's idea. We save last timestamp seen
+		 * from the destination in peer table, when entering
+		 * state TIME-WAIT, and check against it before
+		 * accepting new connection request.
+		 *
+		 * If "isn" is not zero, this request hit alive
+		 * timewait bucket, so that all the necessary checks
+		 * are made in the function processing timewait state.
+		 */
+		if (tmp_opt.saw_tstamp &&
+		    tcp_death_row.sysctl_tw_recycle &&
+		    (dst = inet6_csk_route_req(sk, req)) != NULL &&
+		    (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
+		    ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
+				    &treq->rmt_addr)) {
+			inet_peer_refcheck(peer);
+			if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
+			    (s32)(peer->tcp_ts - req->ts_recent) >
+							TCP_PAWS_WINDOW) {
+				NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
+				goto drop_and_release;
+			}
+		}
+		/* Kill the following clause, if you dislike this way. */
+		else if (!sysctl_tcp_syncookies &&
+			 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
+			  (sysctl_max_syn_backlog >> 2)) &&
+			 (!peer || !peer->tcp_ts_stamp) &&
+			 (!dst || !dst_metric(dst, RTAX_RTT))) {
+			/* Without syncookies last quarter of
+			 * backlog is filled with destinations,
+			 * proven to be alive.
+			 * It means that we continue to communicate
+			 * to destinations, already remembered
+			 * to the moment of synflood.
+			 */
+			LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
+				       &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
+			goto drop_and_release;
+		}
+
+		isn = tcp_v6_init_sequence(skb);
+	}
+have_isn:
+	tcp_rsk(req)->snt_isn = isn;
+	tcp_rsk(req)->snt_synack = tcp_time_stamp;
+
+	security_inet_conn_request(sk, skb, req);
+
+	if (tcp_v6_send_synack(sk, req,
+			       (struct request_values *)&tmp_ext) ||
+	    want_cookie)
+		goto drop_and_free;
+
+	inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+	return 0;
+
+drop_and_release:
+	dst_release(dst);
+drop_and_free:
+	reqsk_free(req);
+drop:
+	return 0; /* don't send reset */
+}
+
+static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
+					  struct request_sock *req,
+					  struct dst_entry *dst)
+{
+	struct inet6_request_sock *treq;
+	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;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *key;
+#endif
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		/*
+		 *	v6 mapped
+		 */
+
+		newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
+
+		if (newsk == NULL)
+			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_v4mapped(newinet->inet_daddr, &newnp->daddr);
+
+		ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
+
+		newnp->rcv_saddr = newnp->saddr;
+
+		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
+		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
+#endif
+
+		newnp->ipv6_ac_list = NULL;
+		newnp->ipv6_fl_list = NULL;
+		newnp->pktoptions  = NULL;
+		newnp->opt	   = NULL;
+		newnp->mcast_oif   = inet6_iif(skb);
+		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
+		newnp->rcv_tclass  = ipv6_tclass(ipv6_hdr(skb));
+
+		/*
+		 * 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
+		 */
+
+		/* It is tricky place. Until this moment IPv4 tcp
+		   worked with IPv6 icsk.icsk_af_ops.
+		   Sync it now.
+		 */
+		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
+
+		return newsk;
+	}
+
+	treq = inet6_rsk(req);
+	opt = np->opt;
+
+	if (sk_acceptq_is_full(sk))
+		goto out_overflow;
+
+	if (!dst) {
+		dst = inet6_csk_route_req(sk, req);
+		if (!dst)
+			goto out;
+	}
+
+	newsk = tcp_create_openreq_child(sk, req, skb);
+	if (newsk == NULL)
+		goto out_nonewsk;
+
+	/*
+	 * 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
+	 */
+
+	newsk->sk_gso_type = SKB_GSO_TCPV6;
+	__ip6_dst_store(newsk, dst, NULL, NULL);
+
+	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));
+
+	newnp->daddr = treq->rmt_addr;
+	newnp->saddr = treq->loc_addr;
+	newnp->rcv_saddr = treq->loc_addr;
+	newsk->sk_bound_dev_if = treq->iif;
+
+	/* Now IPv6 options...
+
+	   First: no IPv4 options.
+	 */
+	newinet->inet_opt = NULL;
+	newnp->ipv6_ac_list = NULL;
+	newnp->ipv6_fl_list = NULL;
+
+	/* Clone RX bits */
+	newnp->rxopt.all = np->rxopt.all;
+
+	/* Clone pktoptions received with SYN */
+	newnp->pktoptions = NULL;
+	if (treq->pktopts != NULL) {
+		newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
+		kfree_skb(treq->pktopts);
+		treq->pktopts = NULL;
+		if (newnp->pktoptions)
+			skb_set_owner_r(newnp->pktoptions, newsk);
+	}
+	newnp->opt	  = NULL;
+	newnp->mcast_oif  = inet6_iif(skb);
+	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+	newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
+
+	/* 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);
+	}
+
+	inet_csk(newsk)->icsk_ext_hdr_len = 0;
+	if (newnp->opt)
+		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
+						     newnp->opt->opt_flen);
+
+	tcp_mtup_init(newsk);
+	tcp_sync_mss(newsk, dst_mtu(dst));
+	newtp->advmss = dst_metric_advmss(dst);
+	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;
+
+	tcp_initialize_rcv_mss(newsk);
+	if (tcp_rsk(req)->snt_synack)
+		tcp_valid_rtt_meas(newsk,
+		    tcp_time_stamp - tcp_rsk(req)->snt_synack);
+	newtp->total_retrans = req->retrans;
+
+	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
+	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+#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.
+		 */
+		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
+			       AF_INET6, key->key, key->keylen, GFP_ATOMIC);
+	}
+#endif
+
+	if (__inet_inherit_port(sk, newsk) < 0) {
+		sock_put(newsk);
+		goto out;
+	}
+	__inet6_hash(newsk, NULL);
+
+	return newsk;
+
+out_overflow:
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+out_nonewsk:
+	if (opt && opt != np->opt)
+		sock_kfree_s(sk, opt, opt->tot_len);
+	dst_release(dst);
+out:
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
+	return NULL;
+}
+
+static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
+{
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
+		if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
+				  &ipv6_hdr(skb)->daddr, skb->csum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			return 0;
+		}
+	}
+
+	skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
+					      &ipv6_hdr(skb)->saddr,
+					      &ipv6_hdr(skb)->daddr, 0));
+
+	if (skb->len <= 76) {
+		return __skb_checksum_complete(skb);
+	}
+	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);
+
+#ifdef CONFIG_TCP_MD5SIG
+	if (tcp_v6_inbound_md5_hash (sk, skb))
+		goto discard;
+#endif
+
+	if (sk_filter(sk, skb))
+		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.
+					       --ANK (980728)
+	 */
+	if (np->rxopt.all)
+		opt_skb = skb_clone(skb, GFP_ATOMIC);
+
+	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+		sock_rps_save_rxhash(sk, skb);
+		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
+			goto reset;
+		if (opt_skb)
+			goto ipv6_pktoptions;
+		return 0;
+	}
+
+	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
+		goto csum_err;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		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..
+		 */
+		if(nsk != sk) {
+			sock_rps_save_rxhash(nsk, skb);
+			if (tcp_child_process(sk, nsk, skb))
+				goto reset;
+			if (opt_skb)
+				__kfree_skb(opt_skb);
+			return 0;
+		}
+	} else
+		sock_rps_save_rxhash(sk, skb);
+
+	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
+		goto reset;
+	if (opt_skb)
+		goto ipv6_pktoptions;
+	return 0;
+
+reset:
+	tcp_v6_send_reset(sk, skb);
+discard:
+	if (opt_skb)
+		__kfree_skb(opt_skb);
+	kfree_skb(skb);
+	return 0;
+csum_err:
+	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
+	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))) {
+		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
+			np->mcast_oif = inet6_iif(opt_skb);
+		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
+			np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
+		if (np->rxopt.bits.rxtclass)
+			np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
+		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);
+		}
+	}
+
+	kfree_skb(opt_skb);
+	return 0;
+}
+
+static int tcp_v6_rcv(struct sk_buff *skb)
+{
+	const struct tcphdr *th;
+	const struct ipv6hdr *hdr;
+	struct sock *sk;
+	int ret;
+	struct net *net = dev_net(skb->dev);
+
+	if (skb->pkt_type != PACKET_HOST)
+		goto discard_it;
+
+	/*
+	 *	Count it even if it's bad.
+	 */
+	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
+
+	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+		goto discard_it;
+
+	th = tcp_hdr(skb);
+
+	if (th->doff < sizeof(struct tcphdr)/4)
+		goto bad_packet;
+	if (!pskb_may_pull(skb, th->doff*4))
+		goto discard_it;
+
+	if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
+		goto bad_packet;
+
+	th = tcp_hdr(skb);
+	hdr = ipv6_hdr(skb);
+	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;
+	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
+	TCP_SKB_CB(skb)->sacked = 0;
+
+	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
+	if (!sk)
+		goto no_tcp_socket;
+
+process:
+	if (sk->sk_state == TCP_TIME_WAIT)
+		goto do_time_wait;
+
+	if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
+		NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
+		goto discard_and_relse;
+	}
+
+	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
+		goto discard_and_relse;
+
+	if (sk_filter(sk, skb))
+		goto discard_and_relse;
+
+	skb->dev = NULL;
+
+	bh_lock_sock_nested(sk);
+	ret = 0;
+	if (!sock_owned_by_user(sk)) {
+#ifdef CONFIG_NET_DMA
+		struct tcp_sock *tp = tcp_sk(sk);
+		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
+			tp->ucopy.dma_chan = net_dma_find_channel();
+		if (tp->ucopy.dma_chan)
+			ret = tcp_v6_do_rcv(sk, skb);
+		else
+#endif
+		{
+			if (!tcp_prequeue(sk, skb))
+				ret = tcp_v6_do_rcv(sk, skb);
+		}
+	} else if (unlikely(sk_add_backlog(sk, skb))) {
+		bh_unlock_sock(sk);
+		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
+		goto discard_and_relse;
+	}
+	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:
+		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
+	} else {
+		tcp_v6_send_reset(NULL, skb);
+	}
+
+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)) {
+		inet_twsk_put(inet_twsk(sk));
+		goto discard_it;
+	}
+
+	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
+		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
+		inet_twsk_put(inet_twsk(sk));
+		goto discard_it;
+	}
+
+	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
+	case TCP_TW_SYN:
+	{
+		struct sock *sk2;
+
+		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
+					    &ipv6_hdr(skb)->daddr,
+					    ntohs(th->dest), inet6_iif(skb));
+		if (sk2 != NULL) {
+			struct inet_timewait_sock *tw = inet_twsk(sk);
+			inet_twsk_deschedule(tw, &tcp_death_row);
+			inet_twsk_put(tw);
+			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 struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
+{
+	struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct inet_peer *peer;
+
+	if (!rt ||
+	    !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
+		peer = inet_getpeer_v6(&np->daddr, 1);
+		*release_it = true;
+	} else {
+		if (!rt->rt6i_peer)
+			rt6_bind_peer(rt, 1);
+		peer = rt->rt6i_peer;
+		*release_it = false;
+	}
+
+	return peer;
+}
+
+static void *tcp_v6_tw_get_peer(struct sock *sk)
+{
+	const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
+	const struct inet_timewait_sock *tw = inet_twsk(sk);
+
+	if (tw->tw_family == AF_INET)
+		return tcp_v4_tw_get_peer(sk);
+
+	return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
+}
+
+static struct timewait_sock_ops tcp6_timewait_sock_ops = {
+	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
+	.twsk_unique	= tcp_twsk_unique,
+	.twsk_destructor= tcp_twsk_destructor,
+	.twsk_getpeer	= tcp_v6_tw_get_peer,
+};
+
+static const struct inet_connection_sock_af_ops ipv6_specific = {
+	.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,
+	.get_peer	   = tcp_v6_get_peer,
+	.net_header_len	   = sizeof(struct ipv6hdr),
+	.setsockopt	   = ipv6_setsockopt,
+	.getsockopt	   = ipv6_getsockopt,
+	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
+	.sockaddr_len	   = sizeof(struct sockaddr_in6),
+	.bind_conflict	   = inet6_csk_bind_conflict,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_ipv6_setsockopt,
+	.compat_getsockopt = compat_ipv6_getsockopt,
+#endif
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
+	.md5_lookup	=	tcp_v6_md5_lookup,
+	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
+	.md5_parse	=	tcp_v6_parse_md5_keys,
+};
+#endif
+
+/*
+ *	TCP over IPv4 via INET6 API
+ */
+
+static const struct inet_connection_sock_af_ops ipv6_mapped = {
+	.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,
+	.get_peer	   = tcp_v4_get_peer,
+	.net_header_len	   = sizeof(struct iphdr),
+	.setsockopt	   = ipv6_setsockopt,
+	.getsockopt	   = ipv6_getsockopt,
+	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
+	.sockaddr_len	   = sizeof(struct sockaddr_in6),
+	.bind_conflict	   = inet6_csk_bind_conflict,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_ipv6_setsockopt,
+	.compat_getsockopt = compat_ipv6_getsockopt,
+#endif
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
+	.md5_lookup	=	tcp_v4_md5_lookup,
+	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
+	.md5_parse	=	tcp_v6_parse_md5_keys,
+};
+#endif
+
+/* 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)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	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);
+
+	icsk->icsk_rto = TCP_TIMEOUT_INIT;
+	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 = TCP_INFINITE_SSTHRESH;
+	tp->snd_cwnd_clamp = ~0;
+	tp->mss_cache = TCP_MSS_DEFAULT;
+
+	tp->reordering = sysctl_tcp_reordering;
+
+	sk->sk_state = TCP_CLOSE;
+
+	icsk->icsk_af_ops = &ipv6_specific;
+	icsk->icsk_ca_ops = &tcp_init_congestion_ops;
+	icsk->icsk_sync_mss = tcp_sync_mss;
+	sk->sk_write_space = sk_stream_write_space;
+	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+#ifdef CONFIG_TCP_MD5SIG
+	tp->af_specific = &tcp_sock_ipv6_specific;
+#endif
+
+	/* TCP Cookie Transactions */
+	if (sysctl_tcp_cookie_size > 0) {
+		/* Default, cookies without s_data_payload. */
+		tp->cookie_values =
+			kzalloc(sizeof(*tp->cookie_values),
+				sk->sk_allocation);
+		if (tp->cookie_values != NULL)
+			kref_init(&tp->cookie_values->kref);
+	}
+	/* Presumed zeroed, in order of appearance:
+	 *	cookie_in_always, cookie_out_never,
+	 *	s_data_constant, s_data_in, s_data_out
+	 */
+	sk->sk_sndbuf = sysctl_tcp_wmem[1];
+	sk->sk_rcvbuf = sysctl_tcp_rmem[1];
+
+	local_bh_disable();
+	sock_update_memcg(sk);
+	sk_sockets_allocated_inc(sk);
+	local_bh_enable();
+
+	return 0;
+}
+
+static void tcp_v6_destroy_sock(struct sock *sk)
+{
+	tcp_v4_destroy_sock(sk);
+	inet6_destroy_sock(sk);
+}
+
+#ifdef CONFIG_PROC_FS
+/* Proc filesystem TCPv6 sock list dumping. */
+static void get_openreq6(struct seq_file *seq,
+			 const struct sock *sk, struct request_sock *req, int i, int uid)
+{
+	int ttd = req->expires - jiffies;
+	const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
+	const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
+
+	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 %pK\n",
+		   i,
+		   src->s6_addr32[0], src->s6_addr32[1],
+		   src->s6_addr32[2], src->s6_addr32[3],
+		   ntohs(inet_rsk(req)->loc_port),
+		   dest->s6_addr32[0], dest->s6_addr32[1],
+		   dest->s6_addr32[2], dest->s6_addr32[3],
+		   ntohs(inet_rsk(req)->rmt_port),
+		   TCP_SYN_RECV,
+		   0,0, /* could print option size, but that is af dependent. */
+		   1,   /* timers active (only the expire timer) */
+		   jiffies_to_clock_t(ttd),
+		   req->retrans,
+		   uid,
+		   0,  /* non standard timer */
+		   0, /* open_requests have no inode */
+		   0, req);
+}
+
+static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
+{
+	const struct in6_addr *dest, *src;
+	__u16 destp, srcp;
+	int timer_active;
+	unsigned long timer_expires;
+	const struct inet_sock *inet = inet_sk(sp);
+	const struct tcp_sock *tp = tcp_sk(sp);
+	const struct inet_connection_sock *icsk = inet_csk(sp);
+	const struct ipv6_pinfo *np = inet6_sk(sp);
+
+	dest  = &np->daddr;
+	src   = &np->rcv_saddr;
+	destp = ntohs(inet->inet_dport);
+	srcp  = ntohs(inet->inet_sport);
+
+	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
+		timer_active	= 1;
+		timer_expires	= icsk->icsk_timeout;
+	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
+		timer_active	= 4;
+		timer_expires	= icsk->icsk_timeout;
+	} 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 "
+		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\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,
+		   sp->sk_state,
+		   tp->write_seq-tp->snd_una,
+		   (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
+		   timer_active,
+		   jiffies_to_clock_t(timer_expires - jiffies),
+		   icsk->icsk_retransmits,
+		   sock_i_uid(sp),
+		   icsk->icsk_probes_out,
+		   sock_i_ino(sp),
+		   atomic_read(&sp->sk_refcnt), sp,
+		   jiffies_to_clock_t(icsk->icsk_rto),
+		   jiffies_to_clock_t(icsk->icsk_ack.ato),
+		   (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
+		   tp->snd_cwnd,
+		   tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
+		   );
+}
+
+static void get_timewait6_sock(struct seq_file *seq,
+			       struct inet_timewait_sock *tw, int i)
+{
+	const struct in6_addr *dest, *src;
+	__u16 destp, srcp;
+	const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
+	int ttd = tw->tw_ttd - jiffies;
+
+	if (ttd < 0)
+		ttd = 0;
+
+	dest = &tw6->tw_v6_daddr;
+	src  = &tw6->tw_v6_rcv_saddr;
+	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 %pK\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 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
+};
+
+static struct tcp_seq_afinfo tcp6_seq_afinfo = {
+	.name		= "tcp6",
+	.family		= AF_INET6,
+	.seq_fops	= &tcp6_afinfo_seq_fops,
+	.seq_ops	= {
+		.show		= tcp6_seq_show,
+	},
+};
+
+int __net_init tcp6_proc_init(struct net *net)
+{
+	return tcp_proc_register(net, &tcp6_seq_afinfo);
+}
+
+void tcp6_proc_exit(struct net *net)
+{
+	tcp_proc_unregister(net, &tcp6_seq_afinfo);
+}
+#endif
+
+struct proto tcpv6_prot = {
+	.name			= "TCPv6",
+	.owner			= THIS_MODULE,
+	.close			= tcp_close,
+	.connect		= tcp_v6_connect,
+	.disconnect		= tcp_disconnect,
+	.accept			= inet_csk_accept,
+	.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,
+	.sendmsg		= tcp_sendmsg,
+	.sendpage		= tcp_sendpage,
+	.backlog_rcv		= tcp_v6_do_rcv,
+	.hash			= tcp_v6_hash,
+	.unhash			= inet_unhash,
+	.get_port		= inet_csk_get_port,
+	.enter_memory_pressure	= tcp_enter_memory_pressure,
+	.sockets_allocated	= &tcp_sockets_allocated,
+	.memory_allocated	= &tcp_memory_allocated,
+	.memory_pressure	= &tcp_memory_pressure,
+	.orphan_count		= &tcp_orphan_count,
+	.sysctl_wmem		= sysctl_tcp_wmem,
+	.sysctl_rmem		= sysctl_tcp_rmem,
+	.max_header		= MAX_TCP_HEADER,
+	.obj_size		= sizeof(struct tcp6_sock),
+	.slab_flags		= SLAB_DESTROY_BY_RCU,
+	.twsk_prot		= &tcp6_timewait_sock_ops,
+	.rsk_prot		= &tcp6_request_sock_ops,
+	.h.hashinfo		= &tcp_hashinfo,
+	.no_autobind		= true,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt	= compat_tcp_setsockopt,
+	.compat_getsockopt	= compat_tcp_getsockopt,
+#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+	.proto_cgroup		= tcp_proto_cgroup,
+#endif
+};
+
+static const struct inet6_protocol tcpv6_protocol = {
+	.handler	=	tcp_v6_rcv,
+	.err_handler	=	tcp_v6_err,
+	.gso_send_check	=	tcp_v6_gso_send_check,
+	.gso_segment	=	tcp_tso_segment,
+	.gro_receive	=	tcp6_gro_receive,
+	.gro_complete	=	tcp6_gro_complete,
+	.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,
+	.flags		=	INET_PROTOSW_PERMANENT |
+				INET_PROTOSW_ICSK,
+};
+
+static int __net_init tcpv6_net_init(struct net *net)
+{
+	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
+				    SOCK_RAW, IPPROTO_TCP, net);
+}
+
+static void __net_exit tcpv6_net_exit(struct net *net)
+{
+	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
+}
+
+static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
+{
+	inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
+}
+
+static struct pernet_operations tcpv6_net_ops = {
+	.init	    = tcpv6_net_init,
+	.exit	    = tcpv6_net_exit,
+	.exit_batch = tcpv6_net_exit_batch,
+};
+
+int __init tcpv6_init(void)
+{
+	int ret;
+
+	ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
+	if (ret)
+		goto out;
+
+	/* register inet6 protocol */
+	ret = inet6_register_protosw(&tcpv6_protosw);
+	if (ret)
+		goto out_tcpv6_protocol;
+
+	ret = register_pernet_subsys(&tcpv6_net_ops);
+	if (ret)
+		goto out_tcpv6_protosw;
+out:
+	return ret;
+
+out_tcpv6_protocol:
+	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
+out_tcpv6_protosw:
+	inet6_unregister_protosw(&tcpv6_protosw);
+	goto out;
+}
+
+void tcpv6_exit(void)
+{
+	unregister_pernet_subsys(&tcpv6_net_ops);
+	inet6_unregister_protosw(&tcpv6_protosw);
+	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
+}