Add support to install multicast rules (#289)

utils/p4runtime_lib/switch.py

@@ -133,6 +133,18 @@ class SwitchConnection(object):
                 yield response
 
 
+    def WriteMulticastGroupEntry(self, mc_entry, dry_run=False):
+        request = p4runtime_pb2.WriteRequest()
+        request.device_id = self.device_id
+        request.election_id.low = 1
+        update = request.updates.add()
+        update.type = p4runtime_pb2.Update.INSERT
+        update.entity.packet_replication_engine_entry.CopyFrom(mc_entry)
+        if dry_run:
+            print "P4Runtime Write:", request
+        else:
+            self.client_stub.Write(request)
+
 class GrpcRequestLogger(grpc.UnaryUnaryClientInterceptor,
                         grpc.UnaryStreamClientInterceptor):
     """Implementation of a gRPC interceptor that logs request to a file"""