[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/netns/ipv4.h b/include/net/netns/ipv4.h
new file mode 100644
index 0000000..ce830d5
--- /dev/null
+++ b/include/net/netns/ipv4.h
@@ -0,0 +1,9 @@
+/*
+ * ipv4 in net namespaces
+ */
+
+#ifndef __NETNS_IPV4_H__
+#define __NETNS_IPV4_H__
+struct netns_ipv4 {
+};
+#endif