vcl/session: tx notifications for cut-thru sessions

Change-Id: I076c753e419bbb177d2d28609190715e9895b398
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index e446a39..993b8bd 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -46,6 +46,7 @@
   void (*update_time) (f64 time_now, u8 thread_index);
   void (*flush_data) (transport_connection_t *tconn);
   int (*custom_tx) (void *session);
+  int (*app_rx_evt) (transport_connection_t *tconn);
 
   /*
    * Connection retrieval
@@ -111,6 +112,16 @@
   return tp_vfts[tp].custom_tx (s);
 }
 
+static inline int
+transport_app_rx_evt (transport_proto_t tp, u32 conn_index, u32 thread_index)
+{
+  transport_connection_t *tc;
+  if (!tp_vfts[tp].app_rx_evt)
+    return 0;
+  tc = transport_get_connection (tp, conn_index, thread_index);
+  return tp_vfts[tp].app_rx_evt (tc);
+}
+
 void transport_register_protocol (transport_proto_t transport_proto,
 				  const transport_proto_vft_t * vft,
 				  fib_protocol_t fib_proto, u32 output_node);