tipc: add function for checking broadcast support in bearer

As a preparation for the 'replicast' functionality we are going to
introduce in the next commits, we need the broadcast base structure to
store whether bearer broadcast is available at all from the currently
used bearer or bearers.

We do this by adding a new function tipc_bearer_bcast_support() to
the bearer layer, and letting the bearer selection function in
bcast.c use this to give a new boolean field, 'bcast_support' the
appropriate value.

Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/bearer.h

@@ -60,9 +60,14 @@
 #define TIPC_MEDIA_TYPE_IB	2
 #define TIPC_MEDIA_TYPE_UDP	3
 
-/* minimum bearer MTU */
+/* Minimum bearer MTU */
 #define TIPC_MIN_BEARER_MTU	(MAX_H_SIZE + INT_H_SIZE)
 
+/* Identifiers for distinguishing between broadcast/multicast and replicast
+ */
+#define TIPC_BROADCAST_SUPPORT  1
+#define TIPC_REPLICAST_SUPPORT  2
+
 /**
  * struct tipc_media_addr - destination address used by TIPC bearers
  * @value: address info (format defined by media)
@@ -210,6 +215,7 @@ int tipc_bearer_setup(void);
 void tipc_bearer_cleanup(void);
 void tipc_bearer_stop(struct net *net);
 int tipc_bearer_mtu(struct net *net, u32 bearer_id);
+bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id);
 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
 			  struct sk_buff *skb,
 			  struct tipc_media_addr *dest);