[NETNS]: Add the netns_ipv4 struct

The ipv4 will store its parameters inside this structure.
This one is empty now, but it will be eventually filled.

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 18da0af..d04ddf2 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -10,6 +10,7 @@
 
 #include <net/netns/unix.h>
 #include <net/netns/packet.h>
+#include <net/netns/ipv4.h>
 
 struct proc_dir_entry;
 struct net_device;
@@ -46,6 +47,7 @@
 
 	struct netns_packet	packet;
 	struct netns_unix	unx;
+	struct netns_ipv4	ipv4;
 };
 
 #ifdef CONFIG_NET