--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/internet-node/ipv4-l4-protocol.h	Fri May 04 15:04:07 2007 +0200
@@ -0,0 +1,85 @@
+// -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*-
+//
+// Copyright (c) 2006 Georgia Tech Research Corporation
+// All rights reserved.
+//
+// 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: George F. Riley<riley@ece.gatech.edu>
+//
+
+// NS3 - Layer 4 Protocol base class
+// George F. Riley, Georgia Tech, Spring 2007
+
+#ifndef IPV4_L4_PROTOCOL_H
+#define IPV4_L4_PROTOCOL_H
+
+#include "ns3/object.h"
+
+namespace ns3 {
+
+class Node;
+class Packet;
+class Ipv4Address;
+class TraceResolver;
+class TraceContext;
+
+/**
+ * \brief L4 Protocol base class 
+ *
+ * All subclasses must implement:
+ *   - Ipv4L4Protocol::Copy
+ *   - Ipv4L4Protocol::CreateTraceResolver
+ *
+ * If you want to implement a new L4 protocol, all you have to do is
+ * implement a subclass of this base class and add it to an L4Demux.
+ */  
+class Ipv4L4Protocol : public Object
+{
+public:
+  Ipv4L4Protocol(int protocolNumber, int version);
+  virtual ~Ipv4L4Protocol ();
+
+  /**
+   * \returns the protocol number of this protocol.
+   */
+  int GetProtocolNumber (void) const;
+  /**
+   * \returns the version number of this protocol.
+   */
+  int GetVersion() const;
+
+  virtual TraceResolver *CreateTraceResolver (TraceContext const &context) = 0;
+
+  /**
+   * \param p packet to forward up
+   * \param source source address of packet received
+   * \param destination address of packet received
+   * 
+   * Called from lower-level layers to send the packet up
+   * in the stack. 
+   */
+  virtual void Receive(Packet& p, 
+                       Ipv4Address const &source,
+                       Ipv4Address const &destination) = 0;
+protected:
+  virtual void DoDispose (void);
+private:
+  int m_protocolNumber;
+  int m_version;
+};
+
+} // Namespace ns3
+
+#endif