From 9bb37ef00e932eb4b989e855245468feb3980700 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 7 Jun 2017 10:34:38 -0700
Subject: [PATCH] tcp: Namespaceify sysctl_tcp_window_scaling

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/netns/ipv4.h   |  1 +
 include/net/tcp.h          |  1 -
 net/ipv4/syncookies.c      |  2 +-
 net/ipv4/sysctl_net_ipv4.c | 14 +++++++-------
 net/ipv4/tcp_input.c       |  3 +--
 net/ipv4/tcp_ipv4.c        |  1 +
 net/ipv4/tcp_output.c      |  4 ++--
 7 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index bb02482ec821..1a2ae74a1085 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -123,6 +123,7 @@ struct netns_ipv4 {
 	unsigned int sysctl_tcp_notsent_lowat;
 	int sysctl_tcp_tw_reuse;
 	int sysctl_tcp_sack;
+	int sysctl_tcp_window_scaling;
 	struct inet_timewait_death_row tcp_death_row;
 	int sysctl_max_syn_backlog;
 
diff --git a/include/net/tcp.h b/include/net/tcp.h
index f9d2ce0ba676..f41ed5bac493 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -238,7 +238,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
 
 /* sysctl variables for tcp */
 extern int sysctl_tcp_timestamps;
-extern int sysctl_tcp_window_scaling;
 extern int sysctl_tcp_fastopen;
 extern int sysctl_tcp_retrans_collapse;
 extern int sysctl_tcp_stdurg;
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index b386e8592ffd..3d74a45773f1 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -257,7 +257,7 @@ bool cookie_timestamp_decode(const struct net *net,
 	tcp_opt->wscale_ok = 1;
 	tcp_opt->snd_wscale = options & TS_OPT_WSCALE_MASK;
 
-	return sysctl_tcp_window_scaling != 0;
+	return net->ipv4.sysctl_tcp_window_scaling != 0;
 }
 EXPORT_SYMBOL(cookie_timestamp_decode);
 
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 74718f8a0aa8..c30ac2ba0e14 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -371,13 +371,6 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
-	{
-		.procname	= "tcp_window_scaling",
-		.data		= &sysctl_tcp_window_scaling,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "tcp_retrans_collapse",
 		.data		= &sysctl_tcp_retrans_collapse,
@@ -1116,6 +1109,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "tcp_window_scaling",
+		.data		= &init_net.ipv4.sysctl_tcp_window_scaling,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2eacfcaf1257..675ee903370f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -77,7 +77,6 @@
 #include <linux/errqueue.h>
 
 int sysctl_tcp_timestamps __read_mostly = 1;
-int sysctl_tcp_window_scaling __read_mostly = 1;
 int sysctl_tcp_fack __read_mostly;
 int sysctl_tcp_max_reordering __read_mostly = 300;
 int sysctl_tcp_dsack __read_mostly = 1;
@@ -3765,7 +3764,7 @@ void tcp_parse_options(const struct net *net,
 				break;
 			case TCPOPT_WINDOW:
 				if (opsize == TCPOLEN_WINDOW && th->syn &&
-				    !estab && sysctl_tcp_window_scaling) {
+				    !estab && net->ipv4.sysctl_tcp_window_scaling) {
 					__u8 snd_wscale = *(__u8 *)ptr;
 					opt_rx->wscale_ok = 1;
 					if (snd_wscale > TCP_MAX_WSCALE) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3c475a2a8432..e07ef5b14aaf 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2466,6 +2466,7 @@ static int __net_init tcp_sk_init(struct net *net)
 
 	net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 256);
 	net->ipv4.sysctl_tcp_sack = 1;
+	net->ipv4.sysctl_tcp_window_scaling = 1;
 
 	return 0;
 fail:
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 45c8e459db49..3f4095010785 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -575,7 +575,7 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 		opts->tsecr = tp->rx_opt.ts_recent;
 		remaining -= TCPOLEN_TSTAMP_ALIGNED;
 	}
-	if (likely(sysctl_tcp_window_scaling)) {
+	if (likely(sock_net(sk)->ipv4.sysctl_tcp_window_scaling)) {
 		opts->ws = tp->rx_opt.rcv_wscale;
 		opts->options |= OPTION_WSCALE;
 		remaining -= TCPOLEN_WSCALE_ALIGNED;
@@ -3303,7 +3303,7 @@ static void tcp_connect_init(struct sock *sk)
 				  tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
 				  &tp->rcv_wnd,
 				  &tp->window_clamp,
-				  sysctl_tcp_window_scaling,
+				  sock_net(sk)->ipv4.sysctl_tcp_window_scaling,
 				  &rcv_wscale,
 				  dst_metric(dst, RTAX_INITRWND));