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

/*

 * Copyright (c) 2005,2006 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

 *

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

 * Modified by Emmanuelle Laprise to remove dependance on LLC headers

 */

#ifndef NET_DEVICE_H

#define NET_DEVICE_H

#include <string>

#include <stdint.h>

#include "ns3/callback.h"

#include "ns3/object.h"

#include "ns3/ptr.h"

#include "address.h"

#include "ipv4-address.h"

namespace ns3 {

class Node;

class TraceResolver;

class TraceContext;

class Channel;

class Packet;

/**

 * \brief Network layer to device interface

 *

 * This interface defines the API which the IP and ARP

 * layers need to access to manage an instance of a network device 

 * layer. It currently does not support MAC-level 

 * multicast but this should not be too hard to add by adding

 * extra methods to register MAC multicast addresses to

 * filter out unwanted packets before handing them to the

 * higher layers.

 *

 * In Linux, this interface is analogous to the interface

 * just above dev_queue_xmit() (i.e., IP packet is fully

 * constructed with destination MAC address already selected).

 * 

 * If you want to write a new MAC layer, you need to subclass

 * this base class and implement your own version of the

 * NetDevice::SendTo method.

 */

class NetDevice : public Object

{

public:

  virtual ~NetDevice();

  /**

   * \return the channel this NetDevice is connected to. The value

   *         returned can be zero if the NetDevice is not yet connected

   *         to any channel.

   */

  Ptr<Channel> GetChannel (void) const;

  /**

   * \return the current Address of this interface.

   */

  Address GetAddress (void) const;

  /**

   * \param mtu MTU value, in bytes, to set for the device

   * \return whether the MTU value was within legal bounds

   * 

   * Override for default MTU defined on a per-type basis.

   */

  bool SetMtu (const uint16_t mtu);

  /**

   * \return the link-level MTU in bytes for this interface.

   * 

   * This value is typically used by the IP layer to perform

   * IP fragmentation when needed.

   */

  uint16_t GetMtu (void) const;

  /**

   * \param name name of the device (e.g. "eth0")

   */

  void SetName(const std::string name); 

  /**

   * \return name name of the device (e.g. "eth0")

   */

  std::string GetName(void) const;

  /**

   * \param index ifIndex of the device 

   */

  void SetIfIndex(const uint32_t index);

  /**

   * \return index ifIndex of the device 

   */

  uint32_t GetIfIndex(void) const;

  /**

   * \return true if link is up; false otherwise

   */

  bool IsLinkUp (void) const;

  /**

   * \param callback the callback to invoke

   *

   * Register a callback invoked whenever the link 

   * status changes to UP. This callback is typically used

   * by the IP/ARP layer to flush the ARP cache 

   * whenever the link goes up.

   */

  void SetLinkChangeCallback (Callback<void> callback);

  /**

   * \return true if this interface supports a broadcast address,

   *         false otherwise.

   */

  bool IsBroadcast (void) const;

  /**

   * \return the broadcast address supported by

   *         this netdevice.

   *

   * Calling this method is invalid if IsBroadcast returns

   * not true.

   */

  Address const &GetBroadcast (void) const;

  /**

   * \return value of m_isMulticast flag

   */

  bool IsMulticast (void) const;

  /**

   * \brief Return the MAC multicast base address used when mapping multicast

   * groups to MAC multicast addresses.

   *

   * Typically when one constructs a multicast MAC addresses, some bits from

   * the IP multicast group are copied into a corresponding MAC multicast 

   * group.  In EUI-48, for example, the low order 23 bits of the multicast

   * group are copied to the MAC multicast group base address.

   *

   * This method allows access to the underlying MAC multicast group base 

   * address.  It is expected that in most cases, a net device client will

   * allow the net device to perform the actual construction of the multicast

   * address.  Use of this method is discouraged unless you have a good reason

   * to perform a custom mapping.  You should prefer 

   * NetDevice::MakeMulticastAddress which will do the RFC-specified mapping

   * for the net device in question.

   *

   * \return The multicast address supported by this net device.

   *

   * \warning Calling this method is invalid if IsMulticast returns not true.

   * The method NS_ASSERTs if the device is not a multicast device.

   * \see NetDevice::MakeMulticastAddress

   */

  Address GetMulticast (void) const;

  /**

   * \brief Make and return a MAC multicast address using the provided

   *        multicast group

   *

   * RFC 1112 says that an Ipv4 host group address is mapped to an Ethernet 

   * multicast address by placing the low-order 23-bits of the IP address into 

   * the low-order 23 bits of the Ethernet multicast address 

   * 01-00-5E-00-00-00 (hex).  Similar RFCs exist for Ipv6 and Eui64 mappings.

   * This method performs the multicast address creation function appropriate

   * to the underlying MAC address of the device.  This MAC address is

   * encapsulated in an abstract Address to avoid dependencies on the exact

   * MAC address format.

   *

   * A default imlementation of MakeMulticastAddress is provided, but this

   * method simply NS_ASSERTS.  In the case of net devices that do not support

   * multicast, clients are expected to test NetDevice::IsMulticast and avoid

   * attempting to map multicast packets.  Subclasses of NetDevice that do

   * support multicasting are expected to override this method and provide an

   * implementation appropriate to the particular device.

   *

   * \param multicastGroup The IP address for the multicast group destination

   * of the packet.

   * \return The MAC multicast Address used to send packets to the provided

   * multicast group.

   *

   * \warning Calling this method is invalid if IsMulticast returns not true.

   * \see Ipv4Address

   * \see Address

   * \see NetDevice::IsMulticast

   */

  virtual Address MakeMulticastAddress (Ipv4Address multicastGroup) const;

  /**

   * \return value of m_isPointToPoint flag

   */

  bool IsPointToPoint (void) const;

  /**

   * \param packet packet sent from above down to Network Device

   * \param dest mac address of the destination (already resolved)

   * \param protocolNumber identifies the type of payload contained in

   *        this packet. Used to call the right L3Protocol when the packet

   *        is received.

   * 

   *  Called from higher layer to send packet into Network Device

   *  to the specified destination Address

   * 

   * \return whether the Send operation succeeded 

   */

  bool Send(Ptr<Packet> packet, const Address& dest, uint16_t protocolNumber);

  /**

   * \returns the node base class which contains this network

   *          interface.

   *

   * When a subclass needs to get access to the underlying node

   * base class to print the nodeid for example, it can invoke

   * this method.

   */

  Ptr<Node> GetNode (void) const;

  /**

   * \returns true if ARP is needed, false otherwise.

   *

   * Called by higher-layers to check if this NetDevice requires

   * ARP to be used.

   */

  bool NeedsArp (void) const;

  /**

   * \param device a pointer to the net device which is calling this callback

   * \param packet the packet received

   * \param protocol the 16 bit protocol number associated with this packet.

   *        This protocol number is expected to be the same protocol number

   *        given to the Send method by the user on the sender side.

   * \param address the address of the sender

   * \returns true if the callback could handle the packet successfully, false

   *          otherwise.

   */

  typedef Callback<bool,Ptr<NetDevice>,Ptr<Packet>,uint16_t,const Address &> ReceiveCallback;

  /**

   * \param cb callback to invoke whenever a packet has been received and must

   *        be forwarded to the higher layers.

   *

   */

  void SetReceiveCallback (ReceiveCallback cb);

 protected:

  /**

   * \param node base class node pointer of device's node 

   * \param addr MAC address of this device.

   */

  NetDevice(Ptr<Node> node, const Address& addr);

  /**

   * Enable broadcast support. This method should be

   * called by subclasses from their constructor

   */

  void EnableBroadcast (Address broadcast);

  /**

   * Set m_isBroadcast flag to false

   */

  void DisableBroadcast (void);

  /**

   * Enable multicast support. This method should be

   * called by subclasses from their constructor

   */

  void EnableMulticast (Address multicast);

  /**

   * Set m_isMulticast flag to false

   */

  void DisableMulticast (void);

  /**

   * Set m_isPointToPoint flag to true

   */

  void EnablePointToPoint (void);

  /**

   * Set m_isPointToPoint flag to false

   */

  void DisablePointToPoint (void);

  /**

   * When a subclass notices that the link status has changed to up,

   * it notifies its parent class by calling this method. This method

   * is responsible for notifying any LinkUp callbacks. 

   */

  void NotifyLinkUp (void);

  /**

   * When a subclass notices that the link status has changed to 

   * down, it notifies its parent class by calling this method.

   */

  void NotifyLinkDown (void);

  /**

   * \param p packet sent from below up to Network Device

   * \param param Extra parameter extracted from header and needed by

   * some protocols

   * \param address the address of the sender of this packet.

   * \returns true if the packet was forwarded successfully,

   *          false otherwise.

   *

   * When a subclass gets a packet from the channel, it 

   * forwards it to the higher layers by calling this method

   * which is responsible for passing it up to the Rx callback.

   */

  bool ForwardUp (Ptr<Packet> p, uint16_t param, const Address &address);

  /**

   * The dispose method for this NetDevice class.

   * Subclasses are expected to override this method _and_

   * to chain up to it by calling NetDevice::DoDispose

   * at the end of their own DoDispose method.

   */

  virtual void DoDispose (void);

 private:

  /**

   * \param p packet to send

   * \param dest address of destination to which packet must be sent

   * \param protocolNumber Number of the protocol (used with some protocols)

   * \returns true if the packet could be sent successfully, false

   *          otherwise.

   *

   * This is the private virtual target function of the public Send()

   * method.  When the link is Up, this method is invoked to ask 

   * subclasses to forward packets. Subclasses MUST override this method.

   */

  virtual bool SendTo (Ptr<Packet> p, const Address &dest, uint16_t protocolNumber) = 0;

  /**

   * \returns true if this NetDevice needs the higher-layers

   *          to perform ARP over it, false otherwise.

   *

   * Subclasses must implement this method.

   */

  virtual bool DoNeedsArp (void) const = 0;

  /**

   * \returns the channel associated to this NetDevice.

   *

   * Subclasses must implement this method.

   */

  virtual Ptr<Channel> DoGetChannel (void) const = 0;

  Ptr<Node>     m_node;

  std::string   m_name;

  uint16_t      m_ifIndex;

  Address       m_address;

  Address       m_broadcast;

  Address       m_multicast;

  uint16_t      m_mtu;

  bool          m_isUp;

  bool          m_isBroadcast;

  bool          m_isMulticast;

  bool          m_isPointToPoint;

  Callback<void> m_linkChangeCallback;

  ReceiveCallback m_receiveCallback;

};

}; // namespace ns3

#endif