// -*- 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_CLOSED,
    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 header IPv4 Header information
   * \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, 
                                Ipv4Header const &header,
                                Ptr<Ipv4Interface> incomingInterface) = 0;

  /**
   * \param icmpSource the source address of the icmp message
   * \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
