ipv4: Namespaceify tcp_retries2 sysctl knob

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv4.h

@@ -103,6 +103,7 @@ struct netns_ipv4 {
 	int sysctl_tcp_syncookies;
 	int sysctl_tcp_reordering;
 	int sysctl_tcp_retries1;
+	int sysctl_tcp_retries2;
 
 	struct ping_group_range ping_group_range;
 

include/net/tcp.h

@@ -240,7 +240,6 @@ extern int sysctl_tcp_timestamps;
 extern int sysctl_tcp_window_scaling;
 extern int sysctl_tcp_sack;
 extern int sysctl_tcp_fin_timeout;
-extern int sysctl_tcp_retries2;
 extern int sysctl_tcp_orphan_retries;
 extern int sysctl_tcp_fastopen;
 extern int sysctl_tcp_retrans_collapse;

net/ipv4/sysctl_net_ipv4.c

@@ -319,13 +319,6 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
-	{
-		.procname	= "tcp_retries2",
-		.data		= &sysctl_tcp_retries2,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "tcp_fin_timeout",
 		.data		= &sysctl_tcp_fin_timeout,
@@ -960,6 +953,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.proc_handler	= proc_dointvec_minmax,
 		.extra2		= &tcp_retr1_max
 	},
+	{
+		.procname	= "tcp_retries2",
+		.data		= &init_net.ipv4.sysctl_tcp_retries2,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

net/ipv4/tcp_ipv4.c

@@ -2392,6 +2392,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_syncookies = 0;
 	net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH;
 	net->ipv4.sysctl_tcp_retries1 = TCP_RETR1;
+	net->ipv4.sysctl_tcp_retries2 = TCP_RETR2;
 
 	return 0;
 fail:

net/ipv4/tcp_output.c

@@ -3476,6 +3476,7 @@ void tcp_send_probe0(struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct net *net = sock_net(sk);
 	unsigned long probe_max;
 	int err;
 
@@ -3489,7 +3490,7 @@ void tcp_send_probe0(struct sock *sk)
 	}
 
 	if (err <= 0) {
-		if (icsk->icsk_backoff < sysctl_tcp_retries2)
+		if (icsk->icsk_backoff < net->ipv4.sysctl_tcp_retries2)
 			icsk->icsk_backoff++;
 		icsk->icsk_probes_out++;
 		probe_max = TCP_RTO_MAX;

net/ipv4/tcp_timer.c

@@ -22,7 +22,6 @@
 #include <linux/gfp.h>
 #include <net/tcp.h>
 
-int sysctl_tcp_retries2 __read_mostly = TCP_RETR2;
 int sysctl_tcp_orphan_retries __read_mostly;
 int sysctl_tcp_thin_linear_timeouts __read_mostly;
 
@@ -189,7 +188,7 @@ static int tcp_write_timeout(struct sock *sk)
 			dst_negative_advice(sk);
 		}
 
-		retry_until = sysctl_tcp_retries2;
+		retry_until = net->ipv4.sysctl_tcp_retries2;
 		if (sock_flag(sk, SOCK_DEAD)) {
 			const bool alive = icsk->icsk_rto < TCP_RTO_MAX;
 
@@ -303,7 +302,7 @@ static void tcp_probe_timer(struct sock *sk)
 		 (s32)(tcp_time_stamp - start_ts) > icsk->icsk_user_timeout)
 		goto abort;
 
-	max_probes = sysctl_tcp_retries2;
+	max_probes = sock_net(sk)->ipv4.sysctl_tcp_retries2;
 	if (sock_flag(sk, SOCK_DEAD)) {
 		const bool alive = inet_csk_rto_backoff(icsk, TCP_RTO_MAX) < TCP_RTO_MAX;