face: introduce NullTransport and use it in several places

Refs: #4528
Change-Id: Icc7a77232bca1a700ce1319493c15a85d05d7488
diff --git a/daemon/face/null-transport.cpp b/daemon/face/null-transport.cpp
new file mode 100644
index 0000000..912bf25
--- /dev/null
+++ b/daemon/face/null-transport.cpp
@@ -0,0 +1,47 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2014-2019,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "null-transport.hpp"
+
+namespace nfd {
+namespace face {
+
+NFD_LOG_INIT(NullTransport);
+
+NullTransport::NullTransport(const FaceUri& localUri, const FaceUri& remoteUri,
+                             ndn::nfd::FaceScope scope, ndn::nfd::FacePersistency persistency)
+{
+  this->setLocalUri(localUri);
+  this->setRemoteUri(remoteUri);
+  this->setScope(scope);
+  this->setPersistency(persistency);
+  this->setLinkType(ndn::nfd::LINK_TYPE_POINT_TO_POINT);
+  this->setMtu(MTU_UNLIMITED);
+
+  NFD_LOG_FACE_DEBUG("Creating transport");
+}
+
+} // namespace face
+} // namespace nfd