--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dsr/model/dsr-gratuitous-reply-table.h	Fri Jan 27 15:15:48 2012 -0800
@@ -0,0 +1,122 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 Yufei Cheng
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Yufei Cheng   <yfcheng@ittc.ku.edu>
+ *
+ * James P.G. Sterbenz <jpgs@ittc.ku.edu>, director
+ * ResiliNets Research Group  http://wiki.ittc.ku.edu/resilinets
+ * Information and Telecommunication Technology Center (ITTC)
+ * and Department of Electrical Engineering and Computer Science
+ * The University of Kansas Lawrence, KS USA.
+ *
+ * Work supported in part by NSF FIND (Future Internet Design) Program
+ * under grant CNS-0626918 (Postmodern Internet Architecture),
+ * NSF grant CNS-1050226 (Multilayer Network Resilience Analysis and Experimentation on GENI),
+ * US Department of Defense (DoD), and ITTC at The University of Kansas.
+ */
+
+#ifndef DSR_GRATUITOUS_REPLY_TABLE_H
+#define DSR_GRATUITOUS_REPLY_TABLE_H
+
+#include "ns3/simulator.h"
+#include "ns3/timer.h"
+#include "ns3/ipv4-address.h"
+#include "ns3/callback.h"
+#include <vector>
+
+namespace ns3 {
+namespace dsr {
+/*
+ * The gratuitous table entries, it maintains the already sent gratuitous route reply entries.
+ * When the node "promiscuously" received a packet destined for other nodes, and inferred a shorter
+ * route for the data packet, it will construct a route reply and send back to the source
+ */
+struct GraReplyEntry
+{
+  Ipv4Address m_replyTo;
+  Ipv4Address m_hearFrom;
+  Time m_gratReplyHoldoff;
+
+  GraReplyEntry (Ipv4Address t, Ipv4Address f, Time h)
+    : m_replyTo (t),
+      m_hearFrom (f),
+      m_gratReplyHoldoff (h)
+  {
+  }
+};
+/**
+ * \ingroup dsr
+ * \brief maintain the gratuitous reply
+ */
+class GraReply  : public Object
+{
+public:
+  // / c-tor
+  /**
+   * \brief Get the type identificator.
+   * \return type identificator
+   */
+  static TypeId GetTypeId ();
+  /**
+   * \brief Constructor.
+   */
+  GraReply ();
+  /**
+   * \brief Destructor.
+   */
+  virtual ~GraReply ();
+  // / Set the gratuitous reply table size
+  void SetGraTableSize (uint32_t g)
+  {
+    GraReplyTableSize = g;
+  }
+  // / Get the gratuitous reply table size
+  uint32_t GetGraTableSize () const
+  {
+    return GraReplyTableSize;
+  }
+  // / Add a new gratuitous reply entry
+  bool AddEntry (GraReplyEntry & graTableEntry);
+  // / Update the route entry if found, create a new one if not
+  bool FindAndUpdate (Ipv4Address replyTo, Ipv4Address replyFrom, Time gratReplyHoldoff);
+  // / Remove all expired entries
+  void Purge ();
+  // / Remove all entries
+  void Clear ()
+  {
+    m_graReply.clear ();
+  }
+
+private:
+  // / Vector of entries
+  std::vector<GraReplyEntry> m_graReply;
+  // / The max # of gratuitous reply entries to hold
+  uint32_t GraReplyTableSize;
+
+  // / Check if the entry is expired or not
+  struct IsExpired
+  {
+    bool operator() (const struct GraReplyEntry & b) const
+    {
+      return (b.m_gratReplyHoldoff < Simulator::Now ());
+    }
+  };
+};
+}  // namespace dsr
+}  // namespace ns3
+
+#endif /* DSR_GRATUITOUS_REPLY_TABLE_H */