--- zzzz-none-000/linux-3.10.107/net/ipv4/tcp_ipv4.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/net/ipv4/tcp_ipv4.c	2021-02-04 17:41:59.000000000 +0000
@@ -72,9 +72,9 @@
 #include <net/inet_common.h>
 #include <net/timewait_sock.h>
 #include <net/xfrm.h>
-#include <net/netdma.h>
 #include <net/secure_seq.h>
 #include <net/tcp_memcontrol.h>
+#include <net/busy_poll.h>
 
 #include <linux/inet.h>
 #include <linux/ipv6.h>
@@ -89,7 +89,6 @@
 int sysctl_tcp_low_latency __read_mostly;
 EXPORT_SYMBOL(sysctl_tcp_low_latency);
 
-
 #ifdef CONFIG_TCP_MD5SIG
 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 			       __be32 daddr, __be32 saddr, const struct tcphdr *th);
@@ -98,7 +97,7 @@
 struct inet_hashinfo tcp_hashinfo;
 EXPORT_SYMBOL(tcp_hashinfo);
 
-static inline __u32 tcp_v4_init_sequence(const struct sk_buff *skb)
+static  __u32 tcp_v4_init_sequence(const struct sk_buff *skb)
 {
 	return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
 					  ip_hdr(skb)->saddr,
@@ -123,7 +122,7 @@
 	   and use initial timestamp retrieved from peer table.
 	 */
 	if (tcptw->tw_ts_recent_stamp &&
-	    (twp == NULL || (sysctl_tcp_tw_reuse &&
+	    (!twp || (sysctl_tcp_tw_reuse &&
 			     get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
 		tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
 		if (tp->write_seq == 0)
@@ -172,7 +171,7 @@
 	rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
 			      RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
 			      IPPROTO_TCP,
-			      orig_sport, orig_dport, sk, true);
+			      orig_sport, orig_dport, sk);
 	if (IS_ERR(rt)) {
 		err = PTR_ERR(rt);
 		if (err == -ENETUNREACH)
@@ -190,7 +189,7 @@
 
 	if (!inet->inet_saddr)
 		inet->inet_saddr = fl4->saddr;
-	inet->inet_rcv_saddr = inet->inet_saddr;
+	sk_rcv_saddr_set(sk, inet->inet_saddr);
 
 	if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) {
 		/* Reset inherited state */
@@ -205,7 +204,7 @@
 		tcp_fetch_timewait_stamp(sk, &rt->dst);
 
 	inet->inet_dport = usin->sin_port;
-	inet->inet_daddr = daddr;
+	sk_daddr_set(sk, daddr);
 
 	inet_csk(sk)->icsk_ext_hdr_len = 0;
 	if (inet_opt)
@@ -223,6 +222,8 @@
 	if (err)
 		goto failure;
 
+	sk_set_txhash(sk);
+
 	rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
 			       inet->inet_sport, inet->inet_dport, sk);
 	if (IS_ERR(rt)) {
@@ -290,6 +291,7 @@
 	mtu = dst_mtu(dst);
 
 	if (inet->pmtudisc != IP_PMTUDISC_DONT &&
+	    ip_sk_accept_pmtu(sk) &&
 	    inet_csk(sk)->icsk_pmtu_cookie > mtu) {
 		tcp_sync_mss(sk, mtu);
 
@@ -311,6 +313,32 @@
 		dst->ops->redirect(dst, sk, skb);
 }
 
+
+/* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */
+void tcp_req_err(struct sock *sk, u32 seq, bool abort)
+{
+	struct request_sock *req = inet_reqsk(sk);
+	struct net *net = sock_net(sk);
+
+	/* ICMPs are not backlogged, hence we cannot get
+	 * an established socket here.
+	 */
+	if (seq != tcp_rsk(req)->snt_isn) {
+		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+	} else if (abort) {
+		/*
+		 * Still in SYN_RECV, just remove it silently.
+		 * There is no good way to pass the error to the newly
+		 * created socket, and POSIX does not want network
+		 * errors returned from accept().
+		 */
+		inet_csk_reqsk_queue_drop(req->rsk_listener, req);
+		NET_INC_STATS_BH(net, LINUX_MIB_LISTENDROPS);
+	}
+	reqsk_put(req);
+}
+EXPORT_SYMBOL(tcp_req_err);
+
 /*
  * This routine is called by the ICMP module when it gets some
  * sort of error condition.  If err < 0 then the socket should
@@ -338,19 +366,15 @@
 	const int code = icmp_hdr(icmp_skb)->code;
 	struct sock *sk;
 	struct sk_buff *skb;
-	struct request_sock *req;
-	__u32 seq;
+	struct request_sock *fastopen;
+	__u32 seq, snd_una;
 	__u32 remaining;
 	int err;
 	struct net *net = dev_net(icmp_skb->dev);
 
-	if (icmp_skb->len < (iph->ihl << 2) + 8) {
-		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
-		return;
-	}
-
-	sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
-			iph->saddr, th->source, inet_iif(icmp_skb));
+	sk = __inet_lookup_established(net, &tcp_hashinfo, iph->daddr,
+				       th->dest, iph->saddr, ntohs(th->source),
+				       inet_iif(icmp_skb));
 	if (!sk) {
 		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
 		return;
@@ -359,6 +383,14 @@
 		inet_twsk_put(inet_twsk(sk));
 		return;
 	}
+	seq = ntohl(th->seq);
+	if (sk->sk_state == TCP_NEW_SYN_RECV)
+		return tcp_req_err(sk, seq,
+				  type == ICMP_PARAMETERPROB ||
+				  type == ICMP_TIME_EXCEEDED ||
+				  (type == ICMP_DEST_UNREACH &&
+				   (code == ICMP_NET_UNREACH ||
+				    code == ICMP_HOST_UNREACH)));
 
 	bh_lock_sock(sk);
 	/* If too many ICMPs get dropped on busy
@@ -380,12 +412,11 @@
 
 	icsk = inet_csk(sk);
 	tp = tcp_sk(sk);
-	req = tp->fastopen_rsk;
-	seq = ntohl(th->seq);
+	/* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
+	fastopen = tp->fastopen_rsk;
+	snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 	if (sk->sk_state != TCP_LISTEN &&
-	    !between(seq, tp->snd_una, tp->snd_nxt) &&
-	    (req == NULL || seq != tcp_rsk(req)->snt_isn)) {
-		/* For a Fast Open socket, allow seq to be snt_isn. */
+	    !between(seq, snd_una, tp->snd_nxt)) {
 		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 		goto out;
 	}
@@ -429,24 +460,23 @@
 		if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
 			break;
 		if (seq != tp->snd_una  || !icsk->icsk_retransmits ||
-		    !icsk->icsk_backoff)
+		    !icsk->icsk_backoff || fastopen)
 			break;
 
-		/* XXX (TFO) - revisit the following logic for TFO */
-
 		if (sock_owned_by_user(sk))
 			break;
 
 		icsk->icsk_backoff--;
-		inet_csk(sk)->icsk_rto = (tp->srtt ? __tcp_set_rto(tp) :
-			TCP_TIMEOUT_INIT) << icsk->icsk_backoff;
-		tcp_bound_rto(sk);
+		icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) :
+					       TCP_TIMEOUT_INIT;
+		icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);
 
 		skb = tcp_write_queue_head(sk);
 		BUG_ON(!skb);
 
-		remaining = icsk->icsk_rto - min(icsk->icsk_rto,
-				tcp_time_stamp - TCP_SKB_CB(skb)->when);
+		remaining = icsk->icsk_rto -
+			    min(icsk->icsk_rto,
+				tcp_time_stamp - tcp_skb_timestamp(skb));
 
 		if (remaining) {
 			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
@@ -465,50 +495,15 @@
 		goto out;
 	}
 
-	/* XXX (TFO) - if it's a TFO socket and has been accepted, rather
-	 * than following the TCP_SYN_RECV case and closing the socket,
-	 * we ignore the ICMP error and keep trying like a fully established
-	 * socket. Is this the right thing to do?
-	 */
-	if (req && req->sk == NULL)
-		goto out;
-
 	switch (sk->sk_state) {
-		struct request_sock *req, **prev;
-	case TCP_LISTEN:
-		if (sock_owned_by_user(sk))
-			goto out;
-
-		req = inet_csk_search_req(sk, &prev, th->dest,
-					  iph->daddr, iph->saddr);
-		if (!req)
-			goto out;
-
-		/* ICMPs are not backlogged, hence we cannot get
-		   an established socket here.
-		 */
-		WARN_ON(req->sk);
-
-		if (seq != tcp_rsk(req)->snt_isn) {
-			NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
-			goto out;
-		}
-
-		/*
-		 * Still in SYN_RECV, just remove it silently.
-		 * There is no good way to pass the error to the newly
-		 * created socket, and POSIX does not want network
-		 * errors returned from accept().
+	case TCP_SYN_SENT:
+	case TCP_SYN_RECV:
+		/* Only in fast or simultaneous open. If a fast open socket is
+		 * is already accepted it is treated as a connected one below.
 		 */
-		inet_csk_reqsk_queue_drop(sk, req, prev);
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
-		goto out;
+		if (fastopen && !fastopen->sk)
+			break;
 
-	case TCP_SYN_SENT:
-	case TCP_SYN_RECV:  /* Cannot happen.
-			       It can f.e. if SYNs crossed,
-			       or Fast Open.
-			     */
 		if (!sock_owned_by_user(sk)) {
 			sk->sk_err = err;
 
@@ -550,8 +545,7 @@
 	sock_put(sk);
 }
 
-static void __tcp_v4_send_check(struct sk_buff *skb,
-				__be32 saddr, __be32 daddr)
+void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr)
 {
 	struct tcphdr *th = tcp_hdr(skb);
 
@@ -576,23 +570,6 @@
 }
 EXPORT_SYMBOL(tcp_v4_send_check);
 
-int tcp_v4_gso_send_check(struct sk_buff *skb)
-{
-	const struct iphdr *iph;
-	struct tcphdr *th;
-
-	if (!pskb_may_pull(skb, sizeof(*th)))
-		return -EINVAL;
-
-	iph = ip_hdr(skb);
-	th = tcp_hdr(skb);
-
-	th->check = 0;
-	skb->ip_summed = CHECKSUM_PARTIAL;
-	__tcp_v4_send_check(skb, iph->saddr, iph->daddr);
-	return 0;
-}
-
 /*
  *	This routine will send an RST to the other tcp.
  *
@@ -606,7 +583,7 @@
  *	Exception: precedence violation. We do not implement it in any case.
  */
 
-static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
+static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct {
@@ -629,7 +606,10 @@
 	if (th->rst)
 		return;
 
-	if (skb_rtable(skb)->rt_type != RTN_LOCAL)
+	/* If sk not NULL, it means we did a successful lookup and incoming
+	 * route had to be correct. prequeue might have dropped our dst.
+	 */
+	if (!sk && skb_rtable(skb)->rt_type != RTN_LOCAL)
 		return;
 
 	/* Swap the send and the receive. */
@@ -651,6 +631,7 @@
 	arg.iov[0].iov_base = (unsigned char *)&rep;
 	arg.iov[0].iov_len  = sizeof(rep.th);
 
+	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 #ifdef CONFIG_TCP_MD5SIG
 	hash_location = tcp_parse_md5sig_option(th);
 	if (!sk && hash_location) {
@@ -661,7 +642,7 @@
 		 * Incoming packet is checked with md5 hash with finding key,
 		 * no RST generated if md5 hash doesn't match.
 		 */
-		sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
+		sk1 = __inet_lookup_listener(net,
 					     &tcp_hashinfo, ip_hdr(skb)->saddr,
 					     th->source, ip_hdr(skb)->daddr,
 					     ntohs(th->source), inet_iif(skb));
@@ -674,7 +655,7 @@
 		if (!key)
 			goto release_sk1;
 
-		genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb);
+		genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
 		if (genhash || memcmp(hash_location, newhash, 16) != 0)
 			goto release_sk1;
 	} else {
@@ -709,11 +690,11 @@
 	if (sk)
 		arg.bound_dev_if = sk->sk_bound_dev_if;
 
-	net = dev_net(skb_dst(skb)->dev);
 	arg.tos = ip_hdr(skb)->tos;
 	ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
-			      skb, ip_hdr(skb)->saddr,
-			      ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
+			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
+			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+			      &arg, arg.iov[0].iov_len);
 
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
@@ -731,7 +712,8 @@
    outside socket context is ugly, certainly. What can I do?
  */
 
-static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
+static void tcp_v4_send_ack(struct net *net,
+			    struct sk_buff *skb, u32 seq, u32 ack,
 			    u32 win, u32 tsval, u32 tsecr, int oif,
 			    struct tcp_md5sig_key *key,
 			    int reply_flags, u8 tos)
@@ -746,7 +728,6 @@
 			];
 	} rep;
 	struct ip_reply_arg arg;
-	struct net *net = dev_net(skb_dst(skb)->dev);
 
 	memset(&rep.th, 0, sizeof(struct tcphdr));
 	memset(&arg, 0, sizeof(arg));
@@ -796,8 +777,9 @@
 		arg.bound_dev_if = oif;
 	arg.tos = tos;
 	ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
-			      skb, ip_hdr(skb)->saddr,
-			      ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
+			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
+			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+			      &arg, arg.iov[0].iov_len);
 
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 }
@@ -807,7 +789,8 @@
 	struct inet_timewait_sock *tw = inet_twsk(sk);
 	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 
-	tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+	tcp_v4_send_ack(sock_net(sk), skb,
+			tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 			tcp_time_stamp + tcptw->tw_ts_offset,
 			tcptw->tw_ts_recent,
@@ -820,16 +803,23 @@
 	inet_twsk_put(tw);
 }
 
-static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
+static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 				  struct request_sock *req)
 {
 	/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 	 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 	 */
-	tcp_v4_send_ack(skb, (sk->sk_state == TCP_LISTEN) ?
-			tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
+	u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
+					     tcp_sk(sk)->snd_nxt;
+
+	/* RFC 7323 2.3
+	 * The window field (SEG.WND) of every outgoing segment, with the
+	 * exception of <SYN> segments, MUST be right-shifted by
+	 * Rcv.Wind.Shift bits:
+	 */
+	tcp_v4_send_ack(sock_net(sk), skb, seq,
 			tcp_rsk(req)->rcv_nxt,
-			req->rcv_wnd >> inet_rsk(req)->rcv_wscale,
+			req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
 			tcp_time_stamp,
 			req->ts_recent,
 			0,
@@ -844,46 +834,35 @@
  *	This still operates on a request_sock only, not on a big
  *	socket.
  */
-static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
+static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
+			      struct flowi *fl,
 			      struct request_sock *req,
-			      u16 queue_mapping,
-			      bool nocache)
+			      struct tcp_fastopen_cookie *foc,
+				  bool attach_req)
 {
 	const struct inet_request_sock *ireq = inet_rsk(req);
 	struct flowi4 fl4;
 	int err = -1;
-	struct sk_buff * skb;
+	struct sk_buff *skb;
 
 	/* First, grab a route. */
 	if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL)
 		return -1;
 
-	skb = tcp_make_synack(sk, dst, req, NULL);
+	skb = tcp_make_synack(sk, dst, req, foc, attach_req);
 
 	if (skb) {
-		__tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);
+		__tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr);
 
-		skb_set_queue_mapping(skb, queue_mapping);
-		err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
-					    ireq->rmt_addr,
+		err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr,
+					    ireq->ir_rmt_addr,
 					    ireq->opt);
 		err = net_xmit_eval(err);
-		if (!tcp_rsk(req)->snt_synack && !err)
-			tcp_rsk(req)->snt_synack = tcp_time_stamp;
 	}
 
 	return err;
 }
 
-static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req)
-{
-	int res = tcp_v4_send_synack(sk, NULL, req, 0, false);
-
-	if (!res)
-		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
-	return res;
-}
-
 /*
  *	IPv4 request_sock destructor.
  */
@@ -892,59 +871,6 @@
 	kfree(inet_rsk(req)->opt);
 }
 
-/*
- * Return true if a syncookie should be sent
- */
-bool tcp_syn_flood_action(struct sock *sk,
-			 const struct sk_buff *skb,
-			 const char *proto)
-{
-	const char *msg = "Dropping request";
-	bool want_cookie = false;
-	struct listen_sock *lopt;
-
-
-
-#ifdef CONFIG_SYN_COOKIES
-	if (sysctl_tcp_syncookies) {
-		msg = "Sending cookies";
-		want_cookie = true;
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES);
-	} else
-#endif
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP);
-
-	lopt = inet_csk(sk)->icsk_accept_queue.listen_opt;
-	if (!lopt->synflood_warned) {
-		lopt->synflood_warned = 1;
-		pr_info("%s: Possible SYN flooding on port %d. %s.  Check SNMP counters.\n",
-			proto, ntohs(tcp_hdr(skb)->dest), msg);
-	}
-	return want_cookie;
-}
-EXPORT_SYMBOL(tcp_syn_flood_action);
-
-/*
- * Save and compile IPv4 options into the request_sock if needed.
- */
-static struct ip_options_rcu *tcp_v4_save_options(struct sk_buff *skb)
-{
-	const struct ip_options *opt = &(IPCB(skb)->opt);
-	struct ip_options_rcu *dopt = NULL;
-
-	if (opt && opt->optlen) {
-		int opt_size = sizeof(*dopt) + opt->optlen;
-
-		dopt = kmalloc(opt_size, GFP_ATOMIC);
-		if (dopt) {
-			if (ip_options_echo(&dopt->opt, skb)) {
-				kfree(dopt);
-				dopt = NULL;
-			}
-		}
-	}
-	return dopt;
-}
 
 #ifdef CONFIG_TCP_MD5SIG
 /*
@@ -954,19 +880,19 @@
  */
 
 /* Find the Key structure for an address.  */
-struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
+struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
 					 const union tcp_md5_addr *addr,
 					 int family)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;
 	unsigned int size = sizeof(struct in_addr);
-	struct tcp_md5sig_info *md5sig;
+	const struct tcp_md5sig_info *md5sig;
 
 	/* caller either holds rcu_read_lock() or socket lock */
 	md5sig = rcu_dereference_check(tp->md5sig_info,
 				       sock_owned_by_user(sk) ||
-				       lockdep_is_held(&sk->sk_lock.slock));
+				       lockdep_is_held((spinlock_t *)&sk->sk_lock.slock));
 	if (!md5sig)
 		return NULL;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -983,25 +909,16 @@
 }
 EXPORT_SYMBOL(tcp_md5_do_lookup);
 
-struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
-					 struct sock *addr_sk)
+struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
+					 const struct sock *addr_sk)
 {
-	union tcp_md5_addr *addr;
+	const union tcp_md5_addr *addr;
 
-	addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_daddr;
+	addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr;
 	return tcp_md5_do_lookup(sk, addr, AF_INET);
 }
 EXPORT_SYMBOL(tcp_v4_md5_lookup);
 
-static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
-						      struct request_sock *req)
-{
-	union tcp_md5_addr *addr;
-
-	addr = (union tcp_md5_addr *)&inet_rsk(req)->rmt_addr;
-	return tcp_md5_do_lookup(sk, addr, AF_INET);
-}
-
 /* This can be called on a newly created socket, from other files */
 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 		   int family, const u8 *newkey, u8 newkeylen, gfp_t gfp)
@@ -1035,7 +952,7 @@
 	key = sock_kmalloc(sk, sizeof(*key), gfp);
 	if (!key)
 		return -ENOMEM;
-	if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) {
+	if (!tcp_alloc_md5sig_pool()) {
 		sock_kfree_s(sk, key, sizeof(*key));
 		return -ENOMEM;
 	}
@@ -1053,9 +970,7 @@
 
 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;
-	struct tcp_md5sig_info *md5sig;
 
 	key = tcp_md5_do_lookup(sk, addr, family);
 	if (!key)
@@ -1063,10 +978,6 @@
 	hlist_del_rcu(&key->node);
 	atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
 	kfree_rcu(key, rcu);
-	md5sig = rcu_dereference_protected(tp->md5sig_info,
-					   sock_owned_by_user(sk));
-	if (hlist_empty(&md5sig->head))
-		tcp_free_md5sig_pool();
 	return 0;
 }
 EXPORT_SYMBOL(tcp_md5_do_del);
@@ -1080,8 +991,6 @@
 
 	md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
 
-	if (!hlist_empty(&md5sig->head))
-		tcp_free_md5sig_pool();
 	hlist_for_each_entry_safe(key, n, &md5sig->head, node) {
 		hlist_del_rcu(&key->node);
 		atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
@@ -1104,7 +1013,7 @@
 	if (sin->sin_family != AF_INET)
 		return -EINVAL;
 
-	if (!cmd.tcpm_key || !cmd.tcpm_keylen)
+	if (!cmd.tcpm_keylen)
 		return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
 				      AF_INET);
 
@@ -1171,8 +1080,8 @@
 	return 1;
 }
 
-int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
-			const struct sock *sk, const struct request_sock *req,
+int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
+			const struct sock *sk,
 			const struct sk_buff *skb)
 {
 	struct tcp_md5sig_pool *hp;
@@ -1180,12 +1089,9 @@
 	const struct tcphdr *th = tcp_hdr(skb);
 	__be32 saddr, daddr;
 
-	if (sk) {
-		saddr = inet_sk(sk)->inet_saddr;
-		daddr = inet_sk(sk)->inet_daddr;
-	} else if (req) {
-		saddr = inet_rsk(req)->loc_addr;
-		daddr = inet_rsk(req)->rmt_addr;
+	if (sk) { /* valid for establish/request sockets */
+		saddr = sk->sk_rcv_saddr;
+		daddr = sk->sk_daddr;
 	} else {
 		const struct iphdr *iph = ip_hdr(skb);
 		saddr = iph->saddr;
@@ -1222,8 +1128,13 @@
 }
 EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
 
-static bool tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
+#endif
+
+/* Called with rcu_read_lock() */
+static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
+				    const struct sk_buff *skb)
 {
+#ifdef CONFIG_TCP_MD5SIG
 	/*
 	 * This gets called for each TCP segment that arrives
 	 * so we want to be efficient.
@@ -1262,7 +1173,7 @@
 	 */
 	genhash = tcp_v4_md5_hash_skb(newhash,
 				      hash_expected,
-				      NULL, NULL, skb);
+				      NULL, skb);
 
 	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 		net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
@@ -1273,371 +1184,73 @@
 		return true;
 	}
 	return false;
+#endif
+	return false;
 }
 
-#endif
+static void tcp_v4_init_req(struct request_sock *req,
+			    const struct sock *sk_listener,
+			    struct sk_buff *skb)
+{
+	struct inet_request_sock *ireq = inet_rsk(req);
+
+	sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr);
+	sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr);
+	ireq->no_srccheck = inet_sk(sk_listener)->transparent;
+	ireq->opt = tcp_v4_save_options(skb);
+}
+
+static struct dst_entry *tcp_v4_route_req(const struct sock *sk,
+					  struct flowi *fl,
+					  const struct request_sock *req,
+					  bool *strict)
+{
+	struct dst_entry *dst = inet_csk_route_req(sk, &fl->u.ip4, req);
+
+	if (strict) {
+		if (fl->u.ip4.daddr == inet_rsk(req)->ir_rmt_addr)
+			*strict = true;
+		else
+			*strict = false;
+	}
+
+	return dst;
+}
 
 struct request_sock_ops tcp_request_sock_ops __read_mostly = {
 	.family		=	PF_INET,
 	.obj_size	=	sizeof(struct tcp_request_sock),
-	.rtx_syn_ack	=	tcp_v4_rtx_synack,
+	.rtx_syn_ack	=	tcp_rtx_synack,
 	.send_ack	=	tcp_v4_reqsk_send_ack,
 	.destructor	=	tcp_v4_reqsk_destructor,
 	.send_reset	=	tcp_v4_send_reset,
-	.syn_ack_timeout = 	tcp_syn_ack_timeout,
+	.syn_ack_timeout =	tcp_syn_ack_timeout,
 };
 
-#ifdef CONFIG_TCP_MD5SIG
 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
-	.md5_lookup	=	tcp_v4_reqsk_md5_lookup,
+	.mss_clamp	=	TCP_MSS_DEFAULT,
+#ifdef CONFIG_TCP_MD5SIG
+	.req_md5_lookup	=	tcp_v4_md5_lookup,
 	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
-};
 #endif
-
-static bool tcp_fastopen_check(struct sock *sk, struct sk_buff *skb,
-			       struct request_sock *req,
-			       struct tcp_fastopen_cookie *foc,
-			       struct tcp_fastopen_cookie *valid_foc)
-{
-	bool skip_cookie = false;
-	struct fastopen_queue *fastopenq;
-
-	if (likely(!fastopen_cookie_present(foc))) {
-		/* See include/net/tcp.h for the meaning of these knobs */
-		if ((sysctl_tcp_fastopen & TFO_SERVER_ALWAYS) ||
-		    ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD) &&
-		    (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1)))
-			skip_cookie = true; /* no cookie to validate */
-		else
-			return false;
-	}
-	fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq;
-	/* A FO option is present; bump the counter. */
-	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVE);
-
-	/* Make sure the listener has enabled fastopen, and we don't
-	 * exceed the max # of pending TFO requests allowed before trying
-	 * to validating the cookie in order to avoid burning CPU cycles
-	 * unnecessarily.
-	 *
-	 * XXX (TFO) - The implication of checking the max_qlen before
-	 * processing a cookie request is that clients can't differentiate
-	 * between qlen overflow causing Fast Open to be disabled
-	 * temporarily vs a server not supporting Fast Open at all.
-	 */
-	if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) == 0 ||
-	    fastopenq == NULL || fastopenq->max_qlen == 0)
-		return false;
-
-	if (fastopenq->qlen >= fastopenq->max_qlen) {
-		struct request_sock *req1;
-		spin_lock(&fastopenq->lock);
-		req1 = fastopenq->rskq_rst_head;
-		if ((req1 == NULL) || time_after(req1->expires, jiffies)) {
-			spin_unlock(&fastopenq->lock);
-			NET_INC_STATS_BH(sock_net(sk),
-			    LINUX_MIB_TCPFASTOPENLISTENOVERFLOW);
-			/* Avoid bumping LINUX_MIB_TCPFASTOPENPASSIVEFAIL*/
-			foc->len = -1;
-			return false;
-		}
-		fastopenq->rskq_rst_head = req1->dl_next;
-		fastopenq->qlen--;
-		spin_unlock(&fastopenq->lock);
-		reqsk_free(req1);
-	}
-	if (skip_cookie) {
-		tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
-		return true;
-	}
-	if (foc->len == TCP_FASTOPEN_COOKIE_SIZE) {
-		if ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_CHKED) == 0) {
-			tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, valid_foc);
-			if ((valid_foc->len != TCP_FASTOPEN_COOKIE_SIZE) ||
-			    memcmp(&foc->val[0], &valid_foc->val[0],
-			    TCP_FASTOPEN_COOKIE_SIZE) != 0)
-				return false;
-			valid_foc->len = -1;
-		}
-		/* Acknowledge the data received from the peer. */
-		tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
-		return true;
-	} else if (foc->len == 0) { /* Client requesting a cookie */
-		tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, valid_foc);
-		NET_INC_STATS_BH(sock_net(sk),
-		    LINUX_MIB_TCPFASTOPENCOOKIEREQD);
-	} else {
-		/* Client sent a cookie with wrong size. Treat it
-		 * the same as invalid and return a valid one.
-		 */
-		tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, valid_foc);
-	}
-	return false;
-}
-
-static int tcp_v4_conn_req_fastopen(struct sock *sk,
-				    struct sk_buff *skb,
-				    struct sk_buff *skb_synack,
-				    struct request_sock *req)
-{
-	struct tcp_sock *tp = tcp_sk(sk);
-	struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
-	const struct inet_request_sock *ireq = inet_rsk(req);
-	struct sock *child;
-	int err;
-
-	req->num_retrans = 0;
-	req->num_timeout = 0;
-	req->sk = NULL;
-
-	child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
-	if (child == NULL) {
-		NET_INC_STATS_BH(sock_net(sk),
-				 LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
-		kfree_skb(skb_synack);
-		return -1;
-	}
-	err = ip_build_and_send_pkt(skb_synack, sk, ireq->loc_addr,
-				    ireq->rmt_addr, ireq->opt);
-	err = net_xmit_eval(err);
-	if (!err)
-		tcp_rsk(req)->snt_synack = tcp_time_stamp;
-	/* XXX (TFO) - is it ok to ignore error and continue? */
-
-	spin_lock(&queue->fastopenq->lock);
-	queue->fastopenq->qlen++;
-	spin_unlock(&queue->fastopenq->lock);
-
-	/* Initialize the child socket. Have to fix some values to take
-	 * into account the child is a Fast Open socket and is created
-	 * only out of the bits carried in the SYN packet.
-	 */
-	tp = tcp_sk(child);
-
-	tp->fastopen_rsk = req;
-	/* Do a hold on the listner sk so that if the listener is being
-	 * closed, the child that has been accepted can live on and still
-	 * access listen_lock.
-	 */
-	sock_hold(sk);
-	tcp_rsk(req)->listener = sk;
-
-	/* RFC1323: The window in SYN & SYN/ACK segments is never
-	 * scaled. So correct it appropriately.
-	 */
-	tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
-	tp->max_window = tp->snd_wnd;
-
-	/* Activate the retrans timer so that SYNACK can be retransmitted.
-	 * The request socket is not added to the SYN table of the parent
-	 * because it's been added to the accept queue directly.
-	 */
-	inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS,
-	    TCP_TIMEOUT_INIT, TCP_RTO_MAX);
-
-	/* Add the child socket directly into the accept queue */
-	inet_csk_reqsk_queue_add(sk, req, child);
-
-	/* Now finish processing the fastopen child socket. */
-	inet_csk(child)->icsk_af_ops->rebuild_header(child);
-	tcp_init_congestion_control(child);
-	tcp_mtup_init(child);
-	tcp_init_buffer_space(child);
-	tcp_init_metrics(child);
-
-	/* Queue the data carried in the SYN packet. We need to first
-	 * bump skb's refcnt because the caller will attempt to free it.
-	 *
-	 * XXX (TFO) - we honor a zero-payload TFO request for now.
-	 * (Any reason not to?)
-	 */
-	if (TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq + 1) {
-		/* Don't queue the skb if there is no payload in SYN.
-		 * XXX (TFO) - How about SYN+FIN?
-		 */
-		tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
-	} else {
-		skb = skb_get(skb);
-		skb_dst_drop(skb);
-		__skb_pull(skb, tcp_hdr(skb)->doff * 4);
-		skb_set_owner_r(skb, child);
-		__skb_queue_tail(&child->sk_receive_queue, skb);
-		tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
-		tp->syn_data_acked = 1;
-	}
-	sk->sk_data_ready(sk, 0);
-	bh_unlock_sock(child);
-	sock_put(child);
-	WARN_ON(req->sk == NULL);
-	return 0;
-}
+	.init_req	=	tcp_v4_init_req,
+#ifdef CONFIG_SYN_COOKIES
+	.cookie_init_seq =	cookie_v4_init_sequence,
+#endif
+	.route_req	=	tcp_v4_route_req,
+	.init_seq	=	tcp_v4_init_sequence,
+	.send_synack	=	tcp_v4_send_synack,
+};
 
 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 {
-	struct tcp_options_received tmp_opt;
-	struct request_sock *req;
-	struct inet_request_sock *ireq;
-	struct tcp_sock *tp = tcp_sk(sk);
-	struct dst_entry *dst = NULL;
-	__be32 saddr = ip_hdr(skb)->saddr;
-	__be32 daddr = ip_hdr(skb)->daddr;
-	__u32 isn = TCP_SKB_CB(skb)->when;
-	bool want_cookie = false;
-	struct flowi4 fl4;
-	struct tcp_fastopen_cookie foc = { .len = -1 };
-	struct tcp_fastopen_cookie valid_foc = { .len = -1 };
-	struct sk_buff *skb_synack;
-	int do_fastopen;
-
 	/* Never answer to SYNs send to broadcast or multicast */
 	if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
 		goto drop;
 
-	/* TW buckets are converted to open requests without
-	 * limitations, they conserve resources and peer is
-	 * evidently real one.
-	 */
-	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
-		want_cookie = tcp_syn_flood_action(sk, skb, "TCP");
-		if (!want_cookie)
-			goto drop;
-	}
-
-	/* Accept backlog is full. If we have already queued enough
-	 * of warm entries in syn queue, drop request. It is better than
-	 * clogging syn queue with openreqs with exponentially increasing
-	 * timeout.
-	 */
-	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
-		goto drop;
-	}
-
-	req = inet_reqsk_alloc(&tcp_request_sock_ops);
-	if (!req)
-		goto drop;
-
-#ifdef CONFIG_TCP_MD5SIG
-	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
-#endif
-
-	tcp_clear_options(&tmp_opt);
-	tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
-	tmp_opt.user_mss  = tp->rx_opt.user_mss;
-	tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc);
+	return tcp_conn_request(&tcp_request_sock_ops,
+				&tcp_request_sock_ipv4_ops, sk, skb);
 
-	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);
-
-	ireq = inet_rsk(req);
-	ireq->loc_addr = daddr;
-	ireq->rmt_addr = saddr;
-	ireq->no_srccheck = inet_sk(sk)->transparent;
-	ireq->opt = tcp_v4_save_options(skb);
-
-	if (security_inet_conn_request(sk, skb, req))
-		goto drop_and_free;
-
-	if (!want_cookie || tmp_opt.tstamp_ok)
-		TCP_ECN_create_request(req, skb, sock_net(sk));
-
-	if (want_cookie) {
-		isn = cookie_v4_init_sequence(sk, skb, &req->mss);
-		req->cookie_ts = tmp_opt.tstamp_ok;
-	} else if (!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 = inet_csk_route_req(sk, &fl4, req)) != NULL &&
-		    fl4.daddr == saddr) {
-			if (!tcp_peer_is_proven(req, dst, true)) {
-				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)) &&
-			 !tcp_peer_is_proven(req, dst, false)) {
-			/* 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 pr_fmt("drop open request from %pI4/%u\n"),
-				       &saddr, ntohs(tcp_hdr(skb)->source));
-			goto drop_and_release;
-		}
-
-		isn = tcp_v4_init_sequence(skb);
-	}
-	tcp_rsk(req)->snt_isn = isn;
-
-	if (dst == NULL) {
-		dst = inet_csk_route_req(sk, &fl4, req);
-		if (dst == NULL)
-			goto drop_and_free;
-	}
-	do_fastopen = tcp_fastopen_check(sk, skb, req, &foc, &valid_foc);
-
-	/* We don't call tcp_v4_send_synack() directly because we need
-	 * to make sure a child socket can be created successfully before
-	 * sending back synack!
-	 *
-	 * XXX (TFO) - Ideally one would simply call tcp_v4_send_synack()
-	 * (or better yet, call tcp_send_synack() in the child context
-	 * directly, but will have to fix bunch of other code first)
-	 * after syn_recv_sock() except one will need to first fix the
-	 * latter to remove its dependency on the current implementation
-	 * of tcp_v4_send_synack()->tcp_select_initial_window().
-	 */
-	skb_synack = tcp_make_synack(sk, dst, req,
-	    fastopen_cookie_present(&valid_foc) ? &valid_foc : NULL);
-
-	if (skb_synack) {
-		__tcp_v4_send_check(skb_synack, ireq->loc_addr, ireq->rmt_addr);
-		skb_set_queue_mapping(skb_synack, skb_get_queue_mapping(skb));
-	} else
-		goto drop_and_free;
-
-	if (likely(!do_fastopen)) {
-		int err;
-		err = ip_build_and_send_pkt(skb_synack, sk, ireq->loc_addr,
-		     ireq->rmt_addr, ireq->opt);
-		err = net_xmit_eval(err);
-		if (err || want_cookie)
-			goto drop_and_free;
-
-		tcp_rsk(req)->snt_synack = tcp_time_stamp;
-		tcp_rsk(req)->listener = NULL;
-		/* Add the request_sock to the SYN table */
-		inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
-		if (fastopen_cookie_present(&foc) && foc.len != 0)
-			NET_INC_STATS_BH(sock_net(sk),
-			    LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
-	} else if (tcp_v4_conn_req_fastopen(sk, skb, skb_synack, req))
-		goto drop_and_free;
-
-	return 0;
-
-drop_and_release:
-	dst_release(dst);
-drop_and_free:
-	reqsk_free(req);
 drop:
 	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 	return 0;
@@ -1649,9 +1262,11 @@
  * The three way handshake has completed - we got a valid synack -
  * now create the new socket.
  */
-struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
+struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 				  struct request_sock *req,
-				  struct dst_entry *dst)
+				  struct dst_entry *dst,
+				  struct request_sock *req_unhash,
+				  bool *own_req)
 {
 	struct inet_request_sock *ireq;
 	struct inet_sock *newinet;
@@ -1675,9 +1290,9 @@
 	newtp		      = tcp_sk(newsk);
 	newinet		      = inet_sk(newsk);
 	ireq		      = inet_rsk(req);
-	newinet->inet_daddr   = ireq->rmt_addr;
-	newinet->inet_rcv_saddr = ireq->loc_addr;
-	newinet->inet_saddr	      = ireq->loc_addr;
+	sk_daddr_set(newsk, ireq->ir_rmt_addr);
+	sk_rcv_saddr_set(newsk, ireq->ir_loc_addr);
+	newinet->inet_saddr	      = ireq->ir_loc_addr;
 	inet_opt	      = ireq->opt;
 	rcu_assign_pointer(newinet->inet_opt, inet_opt);
 	ireq->opt	      = NULL;
@@ -1698,7 +1313,8 @@
 	}
 	sk_setup_caps(newsk, dst);
 
-	tcp_mtup_init(newsk);
+	tcp_ca_openreq_child(newsk, dst);
+
 	tcp_sync_mss(newsk, dst_mtu(dst));
 	newtp->advmss = dst_metric_advmss(dst);
 	if (tcp_sk(sk)->rx_opt.user_mss &&
@@ -1706,14 +1322,12 @@
 		newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
 
 	tcp_initialize_rcv_mss(newsk);
-	tcp_synack_rtt_meas(newsk, req);
-	newtp->total_retrans = req->num_retrans;
 
 #ifdef CONFIG_TCP_MD5SIG
 	/* Copy over the MD5 key from the original socket */
 	key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr,
 				AF_INET);
-	if (key != NULL) {
+	if (key) {
 		/*
 		 * We're using one, so create a matching key
 		 * on the newsk structure. If we fail to get
@@ -1728,7 +1342,9 @@
 
 	if (__inet_inherit_port(sk, newsk) < 0)
 		goto put_and_exit;
-	__inet_hash_nolisten(newsk, NULL);
+	*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
+	if (*own_req)
+		tcp_move_syn(newtp, req);
 
 	return newsk;
 
@@ -1746,61 +1362,19 @@
 }
 EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
 
-static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
+static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb)
 {
-	struct tcphdr *th = tcp_hdr(skb);
-	const struct iphdr *iph = ip_hdr(skb);
-	struct sock *nsk;
-	struct request_sock **prev;
-	/* Find possible connection requests. */
-	struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
-						       iph->saddr, iph->daddr);
-	if (req)
-		return tcp_check_req(sk, skb, req, prev, false);
-
-	nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
-			th->source, iph->daddr, th->dest, inet_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
+	const struct tcphdr *th = tcp_hdr(skb);
+
 	if (!th->syn)
-		sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
+		sk = cookie_v4_check(sk, skb);
 #endif
 	return sk;
 }
 
-static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
-{
-	const struct iphdr *iph = ip_hdr(skb);
-
-	if (skb->ip_summed == CHECKSUM_COMPLETE) {
-		if (!tcp_v4_check(skb->len, iph->saddr,
-				  iph->daddr, skb->csum)) {
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
-			return 0;
-		}
-	}
-
-	skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
-				       skb->len, IPPROTO_TCP, 0);
-
-	if (skb->len <= 76) {
-		return __skb_checksum_complete(skb);
-	}
-	return 0;
-}
-
-
 /* The socket must have it's spinlock held when we get
- * here.
+ * here, unless it is a TCP_LISTEN socket.
  *
  * We have a potential double-lock case here, so even when
  * doing backlog processing we use the BH locking scheme.
@@ -1810,45 +1384,34 @@
 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	struct sock *rsk;
-#ifdef CONFIG_TCP_MD5SIG
-	/*
-	 * We really want to reject the packet as early as possible
-	 * if:
-	 *  o We're expecting an MD5'd packet and this is no MD5 tcp option
-	 *  o There is an MD5 option and we're not expecting one
-	 */
-	if (tcp_v4_inbound_md5_hash(sk, skb))
-		goto discard;
-#endif
 
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
 		struct dst_entry *dst = sk->sk_rx_dst;
 
 		sock_rps_save_rxhash(sk, skb);
+		sk_mark_napi_id(sk, skb);
 		if (dst) {
 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
-			    dst->ops->check(dst, 0) == NULL) {
+			    !dst->ops->check(dst, 0)) {
 				dst_release(dst);
 				sk->sk_rx_dst = NULL;
 			}
 		}
-		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
-			rsk = sk;
-			goto reset;
-		}
+		tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
 		return 0;
 	}
 
-	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
+	if (tcp_checksum_complete(skb))
 		goto csum_err;
 
 	if (sk->sk_state == TCP_LISTEN) {
-		struct sock *nsk = tcp_v4_hnd_req(sk, skb);
+		struct sock *nsk = tcp_v4_cookie_check(sk, skb);
+
 		if (!nsk)
 			goto discard;
-
 		if (nsk != sk) {
 			sock_rps_save_rxhash(nsk, skb);
+			sk_mark_napi_id(nsk, skb);
 			if (tcp_child_process(sk, nsk, skb)) {
 				rsk = nsk;
 				goto reset;
@@ -1858,7 +1421,7 @@
 	} else
 		sock_rps_save_rxhash(sk, skb);
 
-	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
+	if (tcp_rcv_state_process(sk, skb)) {
 		rsk = sk;
 		goto reset;
 	}
@@ -1907,8 +1470,8 @@
 	if (sk) {
 		skb->sk = sk;
 		skb->destructor = sock_edemux;
-		if (sk->sk_state != TCP_TIME_WAIT) {
-			struct dst_entry *dst = ACCESS_ONCE(sk->sk_rx_dst);
+		if (sk_fullsock(sk)) {
+			struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
 
 			if (dst)
 				dst = dst_check(dst, 0);
@@ -1937,7 +1500,17 @@
 	    skb_queue_len(&tp->ucopy.prequeue) == 0)
 		return false;
 
-	skb_dst_force(skb);
+	/* Before escaping RCU protected region, we need to take care of skb
+	 * dst. Prequeue is only enabled for established sockets.
+	 * For such sockets, we might need the skb dst only to set sk->sk_rx_dst
+	 * Instead of doing full sk_rx_dst validity here, let's perform
+	 * an optimistic check.
+	 */
+	if (likely(sk->sk_rx_dst))
+		skb_dst_drop(skb);
+	else
+		skb_dst_force_safe(skb);
+
 	__skb_queue_tail(&tp->ucopy.prequeue, skb);
 	tp->ucopy.memory += skb->truesize;
 	if (tp->ucopy.memory > sk->sk_rcvbuf) {
@@ -2011,19 +1584,29 @@
 	 * Packet length and doff are validated by header prediction,
 	 * provided case of th->doff==0 is eliminated.
 	 * So, we defer the checks. */
-	if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
+
+	if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo))
 		goto csum_error;
 
 	th = tcp_hdr(skb);
 	iph = ip_hdr(skb);
+	/* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
+	 * barrier() makes sure compiler wont play fool^Waliasing games.
+	 */
+	memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb),
+		sizeof(struct inet_skb_parm));
+	barrier();
+
 	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)->tcp_flags = tcp_flag_byte(th);
+	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
 	TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
 	TCP_SKB_CB(skb)->sacked	 = 0;
 
+lookup:
 	sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
 	if (!sk)
 		goto no_tcp_socket;
@@ -2032,6 +1615,35 @@
 	if (sk->sk_state == TCP_TIME_WAIT)
 		goto do_time_wait;
 
+	if (sk->sk_state == TCP_NEW_SYN_RECV) {
+		struct request_sock *req = inet_reqsk(sk);
+		struct sock *nsk;
+
+		sk = req->rsk_listener;
+		if (unlikely(tcp_v4_inbound_md5_hash(sk, skb))) {
+			reqsk_put(req);
+			goto discard_it;
+		}
+		if (unlikely(sk->sk_state != TCP_LISTEN)) {
+			inet_csk_reqsk_queue_drop_and_put(sk, req);
+			goto lookup;
+		}
+		sock_hold(sk);
+		nsk = tcp_check_req(sk, skb, req, false);
+		if (!nsk) {
+			reqsk_put(req);
+			goto discard_and_relse;
+		}
+		if (nsk == sk) {
+			reqsk_put(req);
+		} else if (tcp_child_process(sk, nsk, skb)) {
+			tcp_v4_send_reset(nsk, skb);
+			goto discard_and_relse;
+		} else {
+			sock_put(sk);
+			return 0;
+		}
+	}
 	if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
 		NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 		goto discard_and_relse;
@@ -2039,6 +1651,10 @@
 
 	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto discard_and_relse;
+
+	if (tcp_v4_inbound_md5_hash(sk, skb))
+		goto discard_and_relse;
+
 	nf_reset(skb);
 
 	if (tcp_filter(sk, skb))
@@ -2048,21 +1664,19 @@
 
 	skb->dev = NULL;
 
+	if (sk->sk_state == TCP_LISTEN) {
+		ret = tcp_v4_do_rcv(sk, skb);
+		goto put_and_return;
+	}
+
+	sk_incoming_cpu_update(sk);
+
 	bh_lock_sock_nested(sk);
+	tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
 	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)
+		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v4_do_rcv(sk, skb);
-		else
-#endif
-		{
-			if (!tcp_prequeue(sk, skb))
-				ret = tcp_v4_do_rcv(sk, skb);
-		}
 	} else if (unlikely(sk_add_backlog(sk, skb,
 					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
 		bh_unlock_sock(sk);
@@ -2071,6 +1685,7 @@
 	}
 	bh_unlock_sock(sk);
 
+put_and_return:
 	sock_put(sk);
 
 	return ret;
@@ -2079,7 +1694,7 @@
 	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 		goto discard_it;
 
-	if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
+	if (tcp_checksum_complete(skb)) {
 csum_error:
 		TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
 bad_packet:
@@ -2103,10 +1718,6 @@
 		goto discard_it;
 	}
 
-	if (skb->len < (th->doff << 2)) {
-		inet_twsk_put(inet_twsk(sk));
-		goto bad_packet;
-	}
 	if (tcp_checksum_complete(skb)) {
 		inet_twsk_put(inet_twsk(sk));
 		goto csum_error;
@@ -2119,8 +1730,7 @@
 							iph->daddr, th->dest,
 							inet_iif(skb));
 		if (sk2) {
-			inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
-			inet_twsk_put(inet_twsk(sk));
+			inet_twsk_deschedule_put(inet_twsk(sk));
 			sk = sk2;
 			goto process;
 		}
@@ -2146,9 +1756,10 @@
 {
 	struct dst_entry *dst = skb_dst(skb);
 
-	dst_hold(dst);
-	sk->sk_rx_dst = dst;
-	inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+	if (dst && dst_hold_safe(dst)) {
+		sk->sk_rx_dst = dst;
+		inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+	}
 }
 EXPORT_SYMBOL(inet_sk_rx_dst_set);
 
@@ -2222,11 +1833,6 @@
 	}
 #endif
 
-#ifdef CONFIG_NET_DMA
-	/* Cleans up our sk_async_wait_queue */
-	__skb_queue_purge(&sk->sk_async_wait_queue);
-#endif
-
 	/* Clean prequeue, it must be empty really */
 	__skb_queue_purge(&tp->ucopy.prequeue);
 
@@ -2234,10 +1840,11 @@
 	if (inet_csk(sk)->icsk_bind_hash)
 		inet_put_port(sk);
 
-	BUG_ON(tp->fastopen_rsk != NULL);
+	BUG_ON(tp->fastopen_rsk);
 
 	/* If socket is aborted during connect operation */
 	tcp_free_fastopen_req(tp);
+	tcp_saved_syn_free(tp);
 
 	sk_sockets_allocated_dec(sk);
 	sock_release_memcg(sk);
@@ -2247,18 +1854,6 @@
 #ifdef CONFIG_PROC_FS
 /* Proc filesystem TCP sock list dumping. */
 
-static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
-{
-	return hlist_nulls_empty(head) ? NULL :
-		list_entry(head->first, struct inet_timewait_sock, tw_node);
-}
-
-static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
-{
-	return !is_a_nulls(tw->tw_node.next) ?
-		hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
-}
-
 /*
  * Get next listener socket follow cur.  If cur is NULL, get first socket
  * starting from bucket given in st->bucket; when st->bucket is zero the
@@ -2284,35 +1879,7 @@
 	++st->num;
 	++st->offset;
 
-	if (st->state == TCP_SEQ_STATE_OPENREQ) {
-		struct request_sock *req = cur;
-
-		icsk = inet_csk(st->syn_wait_sk);
-		req = req->dl_next;
-		while (1) {
-			while (req) {
-				if (req->rsk_ops->family == st->family) {
-					cur = req;
-					goto out;
-				}
-				req = req->dl_next;
-			}
-			if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
-				break;
-get_req:
-			req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
-		}
-		sk	  = sk_nulls_next(st->syn_wait_sk);
-		st->state = TCP_SEQ_STATE_LISTENING;
-		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
-	} else {
-		icsk = inet_csk(sk);
-		read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
-		if (reqsk_queue_len(&icsk->icsk_accept_queue))
-			goto start_req;
-		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
-		sk = sk_nulls_next(sk);
-	}
+	sk = sk_nulls_next(sk);
 get_sk:
 	sk_nulls_for_each_from(sk, node) {
 		if (!net_eq(sock_net(sk), net))
@@ -2322,16 +1889,6 @@
 			goto out;
 		}
 		icsk = inet_csk(sk);
-		read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
-		if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
-start_req:
-			st->uid		= sock_i_uid(sk);
-			st->syn_wait_sk = sk;
-			st->state	= TCP_SEQ_STATE_OPENREQ;
-			st->sbucket	= 0;
-			goto get_req;
-		}
-		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
 	}
 	spin_unlock_bh(&ilb->lock);
 	st->offset = 0;
@@ -2362,10 +1919,9 @@
 	return rc;
 }
 
-static inline bool empty_bucket(struct tcp_iter_state *st)
+static inline bool empty_bucket(const struct tcp_iter_state *st)
 {
-	return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
-		hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
+	return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain);
 }
 
 /*
@@ -2382,7 +1938,6 @@
 	for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
 		struct sock *sk;
 		struct hlist_nulls_node *node;
-		struct inet_timewait_sock *tw;
 		spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
 
 		/* Lockless fast path for the common case of empty buckets */
@@ -2398,18 +1953,7 @@
 			rc = sk;
 			goto out;
 		}
-		st->state = TCP_SEQ_STATE_TIME_WAIT;
-		inet_twsk_for_each(tw, node,
-				   &tcp_hashinfo.ehash[st->bucket].twchain) {
-			if (tw->tw_family != st->family ||
-			    !net_eq(twsk_net(tw), net)) {
-				continue;
-			}
-			rc = tw;
-			goto out;
-		}
 		spin_unlock_bh(lock);
-		st->state = TCP_SEQ_STATE_ESTABLISHED;
 	}
 out:
 	return rc;
@@ -2418,7 +1962,6 @@
 static void *established_get_next(struct seq_file *seq, void *cur)
 {
 	struct sock *sk = cur;
-	struct inet_timewait_sock *tw;
 	struct hlist_nulls_node *node;
 	struct tcp_iter_state *st = seq->private;
 	struct net *net = seq_file_net(seq);
@@ -2426,45 +1969,16 @@
 	++st->num;
 	++st->offset;
 
-	if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
-		tw = cur;
-		tw = tw_next(tw);
-get_tw:
-		while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
-			tw = tw_next(tw);
-		}
-		if (tw) {
-			cur = tw;
-			goto out;
-		}
-		spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
-		st->state = TCP_SEQ_STATE_ESTABLISHED;
-
-		/* Look for next non empty bucket */
-		st->offset = 0;
-		while (++st->bucket <= tcp_hashinfo.ehash_mask &&
-				empty_bucket(st))
-			;
-		if (st->bucket > tcp_hashinfo.ehash_mask)
-			return NULL;
-
-		spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
-		sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
-	} else
-		sk = sk_nulls_next(sk);
+	sk = sk_nulls_next(sk);
 
 	sk_nulls_for_each_from(sk, node) {
 		if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
-			goto found;
+			return sk;
 	}
 
-	st->state = TCP_SEQ_STATE_TIME_WAIT;
-	tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
-	goto get_tw;
-found:
-	cur = sk;
-out:
-	return cur;
+	spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
+	++st->bucket;
+	return established_get_first(seq);
 }
 
 static void *established_get_idx(struct seq_file *seq, loff_t pos)
@@ -2506,7 +2020,6 @@
 	void *rc = NULL;
 
 	switch (st->state) {
-	case TCP_SEQ_STATE_OPENREQ:
 	case TCP_SEQ_STATE_LISTENING:
 		if (st->bucket >= INET_LHTABLE_SIZE)
 			break;
@@ -2517,10 +2030,9 @@
 		if (rc)
 			break;
 		st->bucket = 0;
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
 		/* Fallthrough */
 	case TCP_SEQ_STATE_ESTABLISHED:
-	case TCP_SEQ_STATE_TIME_WAIT:
-		st->state = TCP_SEQ_STATE_ESTABLISHED;
 		if (st->bucket > tcp_hashinfo.ehash_mask)
 			break;
 		rc = established_get_first(seq);
@@ -2566,7 +2078,6 @@
 	}
 
 	switch (st->state) {
-	case TCP_SEQ_STATE_OPENREQ:
 	case TCP_SEQ_STATE_LISTENING:
 		rc = listening_get_next(seq, v);
 		if (!rc) {
@@ -2577,7 +2088,6 @@
 		}
 		break;
 	case TCP_SEQ_STATE_ESTABLISHED:
-	case TCP_SEQ_STATE_TIME_WAIT:
 		rc = established_get_next(seq, v);
 		break;
 	}
@@ -2592,16 +2102,10 @@
 	struct tcp_iter_state *st = seq->private;
 
 	switch (st->state) {
-	case TCP_SEQ_STATE_OPENREQ:
-		if (v) {
-			struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
-			read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
-		}
 	case TCP_SEQ_STATE_LISTENING:
 		if (v != SEQ_START_TOKEN)
 			spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
 		break;
-	case TCP_SEQ_STATE_TIME_WAIT:
 	case TCP_SEQ_STATE_ESTABLISHED:
 		if (v)
 			spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
@@ -2622,7 +2126,7 @@
 
 	s = ((struct seq_file *)file->private_data)->private;
 	s->family		= afinfo->family;
-	s->last_pos 		= 0;
+	s->last_pos		= 0;
 	return 0;
 }
 EXPORT_SYMBOL(tcp_seq_open);
@@ -2650,45 +2154,46 @@
 }
 EXPORT_SYMBOL(tcp_proc_unregister);
 
-static void get_openreq4(const struct sock *sk, const struct request_sock *req,
-			 struct seq_file *f, int i, kuid_t uid, int *len)
+static void get_openreq4(const struct request_sock *req,
+			 struct seq_file *f, int i)
 {
 	const struct inet_request_sock *ireq = inet_rsk(req);
-	long delta = req->expires - jiffies;
+	long delta = req->rsk_timer.expires - jiffies;
 
 	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
-		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
+		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK",
 		i,
-		ireq->loc_addr,
-		ntohs(inet_sk(sk)->inet_sport),
-		ireq->rmt_addr,
-		ntohs(ireq->rmt_port),
+		ireq->ir_loc_addr,
+		ireq->ir_num,
+		ireq->ir_rmt_addr,
+		ntohs(ireq->ir_rmt_port),
 		TCP_SYN_RECV,
 		0, 0, /* could print option size, but that is af dependent. */
 		1,    /* timers active (only the expire timer) */
 		jiffies_delta_to_clock_t(delta),
 		req->num_timeout,
-		from_kuid_munged(seq_user_ns(f), uid),
+		from_kuid_munged(seq_user_ns(f),
+				 sock_i_uid(req->rsk_listener)),
 		0,  /* non standard timer */
 		0, /* open_requests have no inode */
-		atomic_read(&sk->sk_refcnt),
-		req,
-		len);
+		0,
+		req);
 }
 
-static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
+static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
 {
 	int timer_active;
 	unsigned long timer_expires;
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	const struct inet_sock *inet = inet_sk(sk);
-	struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
+	const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
 	__be32 dest = inet->inet_daddr;
 	__be32 src = inet->inet_rcv_saddr;
 	__u16 destp = ntohs(inet->inet_dport);
 	__u16 srcp = ntohs(inet->inet_sport);
 	int rx_queue;
+	int state;
 
 	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
 	    icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
@@ -2706,17 +2211,18 @@
 		timer_expires = jiffies;
 	}
 
-	if (sk->sk_state == TCP_LISTEN)
+	state = sk_state_load(sk);
+	if (state == TCP_LISTEN)
 		rx_queue = sk->sk_ack_backlog;
 	else
-		/*
-		 * because we dont lock socket, we might find a transient negative value
+		/* Because we don't lock the socket,
+		 * we might find a transient negative value.
 		 */
 		rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
 
 	seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
-			"%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n",
-		i, src, srcp, dest, destp, sk->sk_state,
+			"%08X %5u %8d %lu %d %pK %lu %lu %u %u %d",
+		i, src, srcp, dest, destp, state,
 		tp->write_seq - tp->snd_una,
 		rx_queue,
 		timer_active,
@@ -2730,18 +2236,17 @@
 		jiffies_to_clock_t(icsk->icsk_ack.ato),
 		(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
 		tp->snd_cwnd,
-		sk->sk_state == TCP_LISTEN ?
-		    (fastopenq ? fastopenq->max_qlen : 0) :
-		    (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh),
-		len);
+		state == TCP_LISTEN ?
+		    fastopenq->max_qlen :
+		    (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh));
 }
 
 static void get_timewait4_sock(const struct inet_timewait_sock *tw,
-			       struct seq_file *f, int i, int *len)
+			       struct seq_file *f, int i)
 {
+	long delta = tw->tw_timer.expires - jiffies;
 	__be32 dest, src;
 	__u16 destp, srcp;
-	long delta = tw->tw_ttd - jiffies;
 
 	dest  = tw->tw_daddr;
 	src   = tw->tw_rcv_saddr;
@@ -2749,10 +2254,10 @@
 	srcp  = ntohs(tw->tw_sport);
 
 	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
-		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK",
 		i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
 		3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
-		atomic_read(&tw->tw_refcnt), tw, len);
+		atomic_read(&tw->tw_refcnt), tw);
 }
 
 #define TMPSZ 150
@@ -2760,31 +2265,25 @@
 static int tcp4_seq_show(struct seq_file *seq, void *v)
 {
 	struct tcp_iter_state *st;
-	int len;
+	struct sock *sk = v;
 
+	seq_setwidth(seq, TMPSZ - 1);
 	if (v == SEQ_START_TOKEN) {
-		seq_printf(seq, "%-*s\n", TMPSZ - 1,
-			   "  sl  local_address rem_address   st tx_queue "
+		seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
 			   "rx_queue tr tm->when retrnsmt   uid  timeout "
 			   "inode");
 		goto out;
 	}
 	st = seq->private;
 
-	switch (st->state) {
-	case TCP_SEQ_STATE_LISTENING:
-	case TCP_SEQ_STATE_ESTABLISHED:
-		get_tcp4_sock(v, seq, st->num, &len);
-		break;
-	case TCP_SEQ_STATE_OPENREQ:
-		get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
-		break;
-	case TCP_SEQ_STATE_TIME_WAIT:
-		get_timewait4_sock(v, seq, st->num, &len);
-		break;
-	}
-	seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
+	if (sk->sk_state == TCP_TIME_WAIT)
+		get_timewait4_sock(v, seq, st->num);
+	else if (sk->sk_state == TCP_NEW_SYN_RECV)
+		get_openreq4(v, seq, st->num);
+	else
+		get_tcp4_sock(v, seq, st->num);
 out:
+	seq_pad(seq, '\n');
 	return 0;
 }
 
@@ -2831,52 +2330,6 @@
 }
 #endif /* CONFIG_PROC_FS */
 
-struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
-{
-	const struct iphdr *iph = skb_gro_network_header(skb);
-	__wsum wsum;
-	__sum16 sum;
-
-	switch (skb->ip_summed) {
-	case CHECKSUM_COMPLETE:
-		if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
-				  skb->csum)) {
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
-			break;
-		}
-flush:
-		NAPI_GRO_CB(skb)->flush = 1;
-		return NULL;
-
-	case CHECKSUM_NONE:
-		wsum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
-					  skb_gro_len(skb), IPPROTO_TCP, 0);
-		sum = csum_fold(skb_checksum(skb,
-					     skb_gro_offset(skb),
-					     skb_gro_len(skb),
-					     wsum));
-		if (sum)
-			goto flush;
-
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		break;
-	}
-
-	return tcp_gro_receive(head, skb);
-}
-
-int tcp4_gro_complete(struct sk_buff *skb)
-{
-	const struct iphdr *iph = ip_hdr(skb);
-	struct tcphdr *th = tcp_hdr(skb);
-
-	th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
-				  iph->saddr, iph->daddr, 0);
-	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
-
-	return tcp_gro_complete(skb);
-}
-
 struct proto tcp_prot = {
 	.name			= "TCP",
 	.owner			= THIS_MODULE,
@@ -2899,10 +2352,12 @@
 	.unhash			= inet_unhash,
 	.get_port		= inet_csk_get_port,
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
+	.stream_memory_free	= tcp_stream_memory_free,
 	.sockets_allocated	= &tcp_sockets_allocated,
 	.orphan_count		= &tcp_orphan_count,
 	.memory_allocated	= &tcp_memory_allocated,
 	.memory_pressure	= &tcp_memory_pressure,
+	.sysctl_mem		= sysctl_tcp_mem,
 	.sysctl_wmem		= sysctl_tcp_wmem,
 	.sysctl_rmem		= sysctl_tcp_rmem,
 	.max_header		= MAX_TCP_HEADER,
@@ -2950,9 +2405,16 @@
 			goto fail;
 		*per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;
 	}
+
 	net->ipv4.sysctl_tcp_ecn = 2;
-	return 0;
+	net->ipv4.sysctl_tcp_ecn_fallback = 1;
 
+	net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS;
+	net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS;
+	net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD;
+	net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL;
+
+	return 0;
 fail:
 	tcp_sk_exit(net);