tipc: add ip/udp media type

The ip/udp bearer can be configured in a point-to-point
mode by specifying both local and remote ip/hostname,
or it can be enabled in multicast mode, where links are
established to all tipc nodes that have joined the same
multicast group. The multicast IP address is generated
based on the TIPC network ID, but can be overridden by
using another multicast address as remote ip.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index c1cc8d7..fa16784 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -87,7 +87,7 @@
  * Note: Headroom should be a multiple of 4 to ensure the TIPC header fields
  *       are word aligned for quicker access
  */
-#define BUF_HEADROOM LL_MAX_HEADER
+#define BUF_HEADROOM (LL_MAX_HEADER + 48)
 
 struct tipc_skb_cb {
 	void *handle;