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

/*

 * Copyright (c) 2005,2006,2007 INRIA

 * 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

 *

 * Authors: 

 *  Mathieu Lacage <mathieu.lacage@sophia.inria.fr>,

 *  Tom Henderson <tomh@tomh.org>

 */

#ifndef IPV4_INTERFACE_H

#define IPV4_INTERFACE_H

#include <list>

#include "ns3/ipv4-address.h"

#include "ns3/ptr.h"

#include "ns3/object.h"

namespace ns3 {

class NetDevice;

class Packet;

class TraceResolver;

class TraceContext;

/**

 * \brief The IPv4 representation of a network interface

 *

 * This class roughly corresponds to the struct in_device

 * of Linux; the main purpose is to provide address-family

 * specific information (addresses) about an interface.

 *

 * This class defines two APIs:

 *  - the public API which is expected to be used by both 

 *    the IPv4 layer and the user during forwarding and 

 *    configuration.

 *  - the private API which is expected to be implemented

 *    by subclasses of this base class. One such subclass 

 *    will be a Loopback interface which loops every

 *    packet sent back to the ipv4 layer. Another such 

 *    subclass typically contains the Ipv4 <-> MAC address

 *    translation logic which will use most of the time the

 *    ARP/RARP protocols.

 *

 * By default, Ipv4 interface are created in the "down" state

 * with ip address 192.168.0.1 and a matching mask. Before

 * becoming useable, the user must invoke SetUp on them

 * once the final Ipv4 address and mask has been set.

 *

 * Subclasses must implement the two methods:

 *   - Ipv4Interface::SendTo

 */

class Ipv4Interface  : public Object

{

public:

  /**

   * \param nd the NetDevice associated to this Ipv4Interface.

   *           This value can be zero in which case the MTU

   *           of this interface will be 2^(16-1).

   */

  Ipv4Interface (Ptr<NetDevice> nd);

  virtual ~Ipv4Interface();

  /**

   * \returns the underlying NetDevice. This method can return

   *          zero if this interface has no associated NetDevice.

   */

  Ptr<NetDevice> GetDevice (void) const;

  /**

   * \param a set the ipv4 address of this interface.

   */

  void SetAddress (Ipv4Address a);

  /**

   * \param mask set the ipv4 netmask of this interface.

   */

  void SetNetworkMask (Ipv4Mask mask);

  /**

   * \returns the broadcast ipv4 address associated to this interface

   */

  Ipv4Address GetBroadcast (void) const;

  /**

   * \returns the ipv4 netmask of this interface

   */

  Ipv4Mask GetNetworkMask (void) const;

  /**

   * \returns the ipv4 address of this interface

   */

  Ipv4Address GetAddress (void) const;

  /**

   * This function a pass-through to NetDevice GetMtu, modulo

   * the  LLC/SNAP header i.e., ipv4MTU = NetDeviceMtu - LLCSNAPSIZE

   * \returns the Maximum Transmission Unit associated to this interface.

   */

  uint16_t GetMtu (void) const;

  /**

   * These are IP interface states and may be distinct from 

   * NetDevice states, such as found in real implementations

   * (where the device may be down but IP interface state is still up).

   */

  /**

   * \returns true if this interface is enabled, false otherwise.

   */

  bool IsUp (void) const;

  /**

   * \returns true if this interface is disabled, false otherwise.

   */

  bool IsDown (void) const;

  /**

   * Enable this interface

   */

  void SetUp (void);

  /**

   * Disable this interface

   */

  void SetDown (void);

  /**

   * \param p packet to send

   * \param dest next hop address of packet.

   *

   * This method will eventually call the private

   * SendTo method which must be implemented by subclasses.

   */ 

  void Send(Packet p, Ipv4Address dest);

protected:

  virtual void DoDispose (void);

private:

  virtual void SendTo (Packet p, Ipv4Address dest) = 0;

  Ptr<NetDevice> m_netdevice;

  bool m_ifup;

  Ipv4Address m_address;

  Ipv4Mask m_netmask;

};

}; // namespace ns3

#endif