mgmt refactoring: Refactor InternalFace

InternalFace is now exclusively for internal use by NFD's forwarding
pipelines.  A separate InternalClientFace has been introduced, intended
to be used by the NFD internal applications, including FIB, Face, RIB
manager, and others.

Change-Id: I4a06b9d05b1613a456c6267582091924557d73be
Refs: #2107
diff --git a/daemon/face/internal-face.hpp b/daemon/face/internal-face.hpp
new file mode 100644
index 0000000..1014fca
--- /dev/null
+++ b/daemon/face/internal-face.hpp
@@ -0,0 +1,102 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  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/>.
+ */
+
+#ifndef NFD_DAEMON_FACE_INTERNAL_FACE_HPP
+#define NFD_DAEMON_FACE_INTERNAL_FACE_HPP
+
+#include "face.hpp"
+
+namespace nfd {
+
+/**
+ * @brief represents a face for internal use in NFD.
+ */
+class InternalFace : public Face
+{
+public:
+
+  InternalFace();
+
+  virtual void
+  sendInterest(const Interest& interest) DECL_OVERRIDE;
+
+  virtual void
+  sendData(const Data& data) DECL_OVERRIDE;
+
+  virtual void
+  close() DECL_OVERRIDE;
+
+  /**
+   * @brief receive a block from a client face
+   *
+   * step1. extracte the packet payload from the received block.
+   * step2. check the type (either Interest or Data) through the payload.
+   * step3. call receiveInterest / receiveData respectively according to the type.
+   *
+   * @param blockFromClient the block from a client face
+   */
+  void
+  receive(const Block& blockFromClient);
+
+  /**
+   * @brief receive an Interest from a client face
+   *
+   * emit the onReceiveInterest signal.
+   *
+   * @param interest the received Interest packet
+   */
+  void
+  receiveInterest(const Interest& interest);
+
+  /**
+   * @brief receive a Data from a client face
+   *
+   * emit the onReceiveData signal.
+   *
+   * @param data the received Data packet
+   */
+  void
+  receiveData(const Data& data);
+
+  /**
+   * @brief compose the whole packet from the received block after payload is extracted
+   *
+   * construct a packet from the extracted payload, and then decode the localControlHeader if the
+   * received block holds more information than the payload.
+   *
+   * @tparam Packet the type of packet, Interest or Data
+   * @param blockFromClient the received block
+   * @param payLoad the extracted payload
+   *
+   * @return a complete packet
+   */
+  template<typename Packet>
+  static shared_ptr<Packet>
+  extractPacketFromBlock(const Block& blockFromClient, const Block& payLoad);
+};
+
+} // namespace nfd
+
+#endif // NFD_DAEMON_FACE_INTERNAL_FACE_HPP