face: NDNLPv2 fragmentation and reassembly

refs #3171

Change-Id: If29035b697b904ee49cb86d9248be488657c6f9e
diff --git a/daemon/face/lp-fragmenter.hpp b/daemon/face/lp-fragmenter.hpp
new file mode 100644
index 0000000..8275d0f
--- /dev/null
+++ b/daemon/face/lp-fragmenter.hpp
@@ -0,0 +1,92 @@
+/* -*- 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_LP_FRAGMENTER_HPP
+#define NFD_DAEMON_FACE_LP_FRAGMENTER_HPP
+
+#include "face-log.hpp"
+
+#include <ndn-cxx/lp/packet.hpp>
+
+namespace nfd {
+namespace face {
+
+class LinkService;
+
+/** \brief fragments network-layer packets into NDNLPv2 link-layer packets
+ *  \sa http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
+ */
+class LpFragmenter
+{
+public:
+  /** \brief Options that control the behavior of LpFragmenter
+   */
+  class Options
+  {
+  public:
+    Options();
+
+  public:
+    /** \brief maximum number of fragments in a packet
+     */
+    size_t nMaxFragments;
+  };
+
+  explicit
+  LpFragmenter(const Options& options = Options(), const LinkService* linkService = nullptr);
+
+  /** \brief set options for fragmenter
+   */
+  void
+  setOptions(const Options& options);
+
+  /** \return LinkService that owns this instance
+   *
+   *  This is only used for logging, and may be nullptr.
+   */
+  const LinkService*
+  getLinkService() const;
+
+  /** \brief fragments a network-layer packet into link-layer packets
+   *  \param packet an LpPacket that contains a network-layer packet;
+   *                must have Fragment field, must not have FragIndex and FragCount fields
+   *  \param mtu maximum allowable LpPacket size after fragmentation and sequence number assignment
+   *  \return whether fragmentation succeeded, fragmented packets without sequence number
+   */
+  std::tuple<bool, std::vector<lp::Packet>>
+  fragmentPacket(const lp::Packet& packet, size_t mtu);
+
+private:
+  Options m_options;
+  const LinkService* m_linkService;
+};
+
+std::ostream&
+operator<<(std::ostream& os, const FaceLogHelper<LpFragmenter>& flh);
+
+} // namespace face
+} // namespace nfd
+
+#endif // NFD_DAEMON_FACE_LP_FRAGMENTER_HPP