netns: Introduce sysctl root for read-only net sysctls.

This one stores all ctl-heads in one list and restricts the
permissions not give write access to non-init net namespaces.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index aa540e6..8df751b 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -201,8 +201,11 @@
 struct ctl_path;
 struct ctl_table;
 struct ctl_table_header;
+
 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
 	const struct ctl_path *path, struct ctl_table *table);
+extern struct ctl_table_header *register_net_sysctl_rotable(
+	const struct ctl_path *path, struct ctl_table *table);
 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 
 #endif /* __NET_NET_NAMESPACE_H */