tipc: Add socket options to get number of queued messages

This patch allows a TIPC application to determine the number of messages
currently waiting in a socket's receive queue (TIPC_SOCK_RECVQ_DEPTH) or
in all TIPC socket receive queues (TIPC_NODE_RECVQ_DEPTH).

Signed-off-by: Oscar Medina <oscar.medina@motorola.com>
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tipc.h b/include/linux/tipc.h
index bea4694..3d92396 100644
--- a/include/linux/tipc.h
+++ b/include/linux/tipc.h
@@ -209,5 +209,7 @@
 #define TIPC_SRC_DROPPABLE	128	/* Default: 0 (resend congested msg) */
 #define TIPC_DEST_DROPPABLE	129	/* Default: based on socket type */
 #define TIPC_CONN_TIMEOUT	130	/* Default: 8000 (ms)  */
+#define TIPC_NODE_RECVQ_DEPTH	131	/* Default: none (read only) */
+#define TIPC_SOCK_RECVQ_DEPTH	132	/* Default: none (read only) */
 
 #endif