// -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*-

//

// Copyright (c) 2006 Georgia Tech Research Corporation

//

// 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"

#include "ns3/ipv4-header.h"

namespace ns3 {

class Packet;

class Ipv4Address;

class Ipv4Interface;

/**

 * \brief L4 Protocol abstract base class 

 *

 * This is an abstract base class for layer four protocols which use IPv4 as

 * the network layer.

 */  

class Ipv4L4Protocol : public Object

{

public:

  enum RxStatus {

    RX_OK,

    RX_CSUM_FAILED,

    RX_ENDPOINT_UNREACH

  };

  static TypeId GetTypeId (void);

  virtual ~Ipv4L4Protocol ();

  /**

   * \returns the protocol number of this protocol.

   */

  virtual int GetProtocolNumber (void) const = 0;

  /**

   * \param p packet to forward up

   * \param source source address of packet received

   * \param destination address of packet received

   * \param incomingInterface the Ipv4Interface on which the packet arrived

   * 

   * Called from lower-level layers to send the packet up

   * in the stack. 

   */

  virtual enum RxStatus Receive(Ptr<Packet> p, 

                                Ipv4Address const &source,

                                Ipv4Address const &destination,

                                Ptr<Ipv4Interface> incomingInterface) = 0;

  /**

   * \param icmpTtl the ttl of the icmp message

   * \param icmpType the 'type' field of the icmp message

   * \param icmpCode the 'code' field of the icmp message

   * \param icmpInfo extra information dependent on the icmp message

   *        generated by Icmpv4L4Protocol

   * \param payloadSource the source address of the packet which triggered

   *        the icmp message

   * \param payloadDestination the destination address of the packet which

   *        triggered the icmp message.

   * \param payload the first 8 bytes of the udp header of the packet

   *        which triggered the icmp message.

   */

  virtual void ReceiveIcmp (Ipv4Address icmpSource, uint8_t icmpTtl,

                            uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo,

                            Ipv4Address payloadSource, Ipv4Address payloadDestination,

                            const uint8_t payload[8]);

};

} // Namespace ns3

#endif