ipv4: Namespacify ip_dynaddr sysctl knob

Signed-off-by: Nikolay Borisov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/ip.h

···
 /* From ip_input.c */
 extern int sysctl_ip_early_demux;
 
-/* From ip_output.c */
-extern int sysctl_ip_dynaddr;
-
 void ipfrag_init(void);
 
 void ip_static_sysctl_init(void);

include/net/netns/ipv4.h

···
 	int sysctl_ip_no_pmtu_disc;
 	int sysctl_ip_fwd_use_pmtu;
 	int sysctl_ip_nonlocal_bind;
+	/* Shall we try to damage output packets if routing dev changes? */
+	int sysctl_ip_dynaddr;
 
 	int sysctl_fwmark_reflect;
 	int sysctl_tcp_fwmark_accept;

net/ipv4/af_inet.c

···
 }
 EXPORT_SYMBOL(inet_unregister_protosw);
 
-/*
- *      Shall we try to damage output packets if routing dev changes?
- */
-
-int sysctl_ip_dynaddr __read_mostly;
-
 static int inet_sk_reselect_saddr(struct sock *sk)
 {
 	struct inet_sock *inet = inet_sk(sk);
···
 	if (new_saddr == old_saddr)
 		return 0;
 
-	if (sysctl_ip_dynaddr > 1) {
+	if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
 			__func__, &old_saddr, &new_saddr);
 	}
···
 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
 		 */
-		if (!sysctl_ip_dynaddr ||
+		if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
 		    sk->sk_state != TCP_SYN_SENT ||
 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
 		    (err = inet_sk_reselect_saddr(sk)) != 0)

net/ipv4/sysctl_net_ipv4.c

···
 		.proc_handler	= proc_dointvec
 	},
 	{
-		.procname	= "ip_dynaddr",
-		.data		= &sysctl_ip_dynaddr,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-	{
 		.procname	= "tcp_fastopen",
 		.data		= &sysctl_tcp_fastopen,
 		.maxlen		= sizeof(int),
···
 		.proc_handler	= proc_dointvec
 	},
 	{
+		.procname	= "ip_dynaddr",
+		.data		= &init_net.ipv4.sysctl_ip_dynaddr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
+	{
 		.procname	= "ip_default_ttl",
 		.data		= &init_net.ipv4.sysctl_ip_default_ttl,
 		.maxlen		= sizeof(int),
···
 		goto err_ports;
 
 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
+	net->ipv4.sysctl_ip_dynaddr = 0;
 
 	return 0;