[NETNS][IPV6]: Make bindv6only sysctl per namespace.

This patch moves the bindv6only sysctl to the network namespace
structure. Until the ipv6 protocol is not per namespace, the sysctl
variable is always from the initial network namespace.
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6.h

@@ -109,7 +109,6 @@ struct frag_hdr {
 #include <net/sock.h>
 
 /* sysctls */
-extern int sysctl_ipv6_bindv6only;
 extern int sysctl_mld_max_msf;
 
 extern struct ctl_path net_ipv6_ctl_path[];

include/net/netns/ipv6.h

@@ -11,6 +11,7 @@ struct netns_sysctl_ipv6 {
 #ifdef CONFIG_SYSCTL
 	struct ctl_table_header *table;
 #endif
+	int bindv6only;
 };
 
 struct netns_ipv6 {

net/ipv6/af_inet6.c

@@ -66,8 +66,6 @@ MODULE_AUTHOR("Cast of dozens");
 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
 MODULE_LICENSE("GPL");
 
-int sysctl_ipv6_bindv6only __read_mostly;
-
 /* The inetsw6 table contains everything that inet6_create needs to
  * build a new socket.
  */
@@ -193,7 +191,7 @@ lookup_protocol:
 	np->mcast_hops	= -1;
 	np->mc_loop	= 1;
 	np->pmtudisc	= IPV6_PMTUDISC_WANT;
-	np->ipv6only	= sysctl_ipv6_bindv6only;
+	np->ipv6only	= init_net.ipv6.sysctl.bindv6only;
 
 	/* Init the ipv4 part of the socket since we can have sockets
 	 * using v6 API for ipv4.
@@ -721,6 +719,7 @@ static void cleanup_ipv6_mibs(void)
 
 static int inet6_net_init(struct net *net)
 {
+	net->ipv6.sysctl.bindv6only = 0;
 	return 0;
 }
 

net/ipv6/sysctl_net_ipv6.c

@@ -35,7 +35,7 @@ static ctl_table ipv6_table_template[] = {
 	{
 		.ctl_name	= NET_IPV6_BINDV6ONLY,
 		.procname	= "bindv6only",
-		.data		= &sysctl_ipv6_bindv6only,
+		.data		= &init_net.ipv6.sysctl.bindv6only,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec
@@ -116,6 +116,8 @@ static int ipv6_sysctl_net_init(struct net *net)
 	ipv6_table[0].child = ipv6_route_table;
 	ipv6_table[1].child = ipv6_icmp_table;
 
+	ipv6_table[2].data = &net->ipv6.sysctl.bindv6only;
+
 	net->ipv6.sysctl.table = register_net_sysctl_table(net, net_ipv6_ctl_path,
 							   ipv6_table);
 	if (!net->ipv6.sysctl.table)