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

/*

 * Copyright (c) 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

 *

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

 */

#ifndef IPV4_H

#define IPV4_H

#include <stdint.h>

#include "ns3/ipv4-address.h"

#include "ns3/object.h"

#include "ns3/callback.h"

#include "ipv4-route.h"

namespace ns3 {

class Node;

class NetDevice;

class Packet;

class Ipv4Route;

class Ipv4Header; // FIXME: ipv4-header.h needs to move from module

                  // "internet-node" to module "node"

/**

 * \brief Base class for IPv4 routing protocols.

 *

 * This class represents the interface between the IPv4 routing core

 * and a specific IPv4 routing protocol.  The interface is

 * asynchronous (callback based) in order to support reactive routing

 * protocols (e.g. AODV).

 */

class Ipv4RoutingProtocol : public Object

{

public:

  // void (*RouteReply) (bool found, Ipv4Route route, Packet packet, Ipv4Header const &ipHeader);

  /**

   * \brief Callback to be invoked when route discovery is completed

   *

   * \param bool flag indicating whether a route was actually found;

   * when this is false, the Ipv4Route parameter is ignored

   *

   * \param Ipv4Route the route found

   *

   * \param Packet the packet for which a route was requested; can be

   * modified by the routing protocol

   *

   * \param Ipv4Header the IP header supplied to the route request

   * method (possibly modified in case a new routing header is

   * inserted and consequently the protocol type has to change).

   *

   */

  /**

   * \brief Asynchronously requests a route for a given packet and IP header

   *

   * \param ifIndex The interface index on which the packet was received.

   * \param ipHeader IP header of the packet

   * \param packet packet that is being sent or forwarded

   * \param routeReply callback that will receive the route reply

   *

   * \returns true if the routing protocol should be able to get the

   * route, false otherwise.

   *

   * This method is called whenever a node's IPv4 forwarding engine

   * needs to lookup a route for a given packet and IP header.

   *

   * The routing protocol implementation may determine immediately it

   * should not be handling this particular the route request.  For

   * instance, a routing protocol may decline to search for routes for

   * certain classes of addresses, like link-local.  In this case,

   * RequestRoute() should return false and the routeReply callback

   * must not be invoked.

   *

   * If the routing protocol implementations assumes it can provide

   * the requested route, then it should return true, and the

   * routeReply callback must be invoked, either immediately before

   * returning true (synchronously), or in the future (asynchronous).

   * The routing protocol may use any information available in the IP

   * header and packet as routing key, although most routing protocols

   * use only the destination address (as given by

   * ipHeader.GetDestination ()).  The routing protocol is also

   * allowed to add a new header to the packet, which will appear

   * immediately after the IP header, although most routing do not

   * insert any extra header.

   */

  virtual bool RequestRoute (uint32_t ifIndex,

                             const Ipv4Header &ipHeader,

                             RouteReplyCallback routeReply) = 0;

/**

 * \brief Synchronously check to see if we can determine the interface index 

 * that will be used if a packet is sent to this destination.

 *

 * This method addresses a problem in the IP stack where a destination address

 * must be present and checksummed into the IP header before the actual 

 * interface over which the packet is sent can be determined.  The answer is

 * to implement a known and intentional cross-layer violation.  This is the

 * endpoint of a call chain that started up quite high in the stack (sockets)

 * and has found its way down to the Ipv4L3Protocol which is consulting the

 * routing protocols for what they would do if presented with a packet of the

 * given destination.

 *

 * Note that the a single interface index is returned.  This means that if

 * the destination address is a multicast, and an explicit route is present

 * that includeds multiple output interfaces, that route cannot be used.

 * 

 * If there are multiple paths out of the node, the resolution is performed

 * by Ipv4L3Protocol::GetIfIndexforDestination which has access to more 

 * contextual information that is useful for making a determination.

 *

 * \param destination The Ipv4Address if the destination of a hypothetical 

 * packet.  This may be a multicast group address.

 * \param ifIndex A reference to the interface index over which a packet

 * sent to this destination would be sent.

 * \return Returns true if a route is found to the destination that involves

 * a single output interface index, otherwise false.

 *

 * \see Ipv4StaticRouting

 * \see Ipv4RoutingProtocol

 * \see Ipv4L3Protocol

 */

  virtual bool RequestIfIndex (Ipv4Address destination, 

                              uint32_t& ifIndex) = 0;

  static const uint32_t IF_INDEX_ANY = 0xffffffff;

};

/**

 * \brief Access to the Ipv4 forwarding table and to the ipv4 interfaces

 *

 * This class allows you to create ipv4 interfaces based on a NetDevice.

 * Multiple interfaces can be created for a single NetDevice, hence

 * achieving multihoming.

 *

 * This class also allows you to control the content of the ipv4 

 * forwarding table.

 */

class Ipv4 : public Object

{

public:

  static const InterfaceId iid;

  Ipv4 ();

  virtual ~Ipv4 ();

  /**

   * \brief Register a new routing protocol to be used in this IPv4 stack

   * 

   * \param routingProtocol new routing protocol implementation object

   * \param priority priority to give to this routing protocol.

   * Values may range between -32768 and +32767.  The priority 0

   * corresponds to static routing table lookups, higher values have

   * more priority.  The order by which routing protocols with the

   * same priority value are consulted is undefined.

   */

  virtual void AddRoutingProtocol (Ptr<Ipv4RoutingProtocol> routingProtocol,

                                   int16_t priority) = 0;

  /**

   * \param dest destination address

   * \param nextHop address of next hop.

   * \param interface interface of next hop.

   *

   * Add route to host dest through host nextHop 

   * on interface.

   */

  virtual void AddHostRouteTo (Ipv4Address dest, 

			       Ipv4Address nextHop, 

			       uint32_t interface) = 0;

  /**

   * \param dest destination address

   * \param interface of next hop

   *

   * add route to host dest on interface.

   */

  virtual void AddHostRouteTo (Ipv4Address dest, 

			       uint32_t interface) = 0;

  /**

   * \param network destination network

   * \param networkMask netmask of destination network

   * \param nextHop address of next hop

   * \param interface interface of next hop

   * 

   * add route to network dest with netmask 

   * through host nextHop on interface

   */

  virtual void AddNetworkRouteTo (Ipv4Address network, 

				  Ipv4Mask networkMask, 

				  Ipv4Address nextHop, 

				  uint32_t interface) = 0;

  /**

   * \param network destination network

   * \param networkMask netmask of destination network

   * \param interface interface of next hop

   *

   * add route to network dest with netmask 

   * on interface

   */

  virtual void AddNetworkRouteTo (Ipv4Address network, 

				  Ipv4Mask networkMask, 

				  uint32_t interface) = 0;

  /**

   * \param nextHop address of default next hop

   * \param interface interface of default next hop.

   * 

   * set the default route to host nextHop on

   * interface. 

   */

  virtual void SetDefaultRoute (Ipv4Address nextHop, 

				uint32_t interface) = 0;

  /**

   * \returns the number of entries in the routing table.

   */

  virtual uint32_t GetNRoutes (void) = 0;

  /**

   * \param i index of route to return

   * \returns the route whose index is i

   */

  virtual Ipv4Route GetRoute (uint32_t i) = 0;

  /**

   * \param i index of route to remove from routing table.

   */

  virtual void RemoveRoute (uint32_t i) = 0;

  /**

   * \brief Add a static multicast route for a given multicast source and 

   *        group.

   *

   * \param origin The Ipv4 address of the multicast source.

   * \param group The multicast group address.

   * \param inputInterface The interface index over which the packet arrived.

   * \param outputInterfaces The list of output interface indices over which 

   *        the packet should be sent (excluding the inputInterface).

   */

  virtual void AddMulticastRoute (Ipv4Address origin,

                                  Ipv4Address group,

                                  uint32_t inputInterface,

                                  std::vector<uint32_t> outputInterfaces) = 0;

  /**

   * \brief Remove a static multicast route for a given multicast source and

   *        group.

   *

   * \param origin The Ipv4 address of the multicast source.

   * \param group The multicast group address.

   * \param inputInterface The interface index over which the packet arrived.

   */

  virtual void RemoveMulticastRoute (Ipv4Address origin,

                                     Ipv4Address group,

                                     uint32_t inputInterface) = 0;

  /**

   * \brief Set the default static multicast route.

   *

   * \param outputInterface The network output interface index over which 

   *        packets without specific routes should be sent.

   */

  virtual void SetDefaultMulticastRoute (uint32_t outputInterface) = 0;

  /**

   * \returns the number of entries in the multicast routing table.

   */

  virtual uint32_t GetNMulticastRoutes (void) const = 0;

  /**

   * \param i index of route to return

   * \returns the route whose index is i

   */

  virtual Ipv4MulticastRoute GetMulticastRoute (uint32_t i) const = 0;

  /**

   * \param i index of route to remove from routing table.

   */

  virtual void RemoveMulticastRoute (uint32_t i) = 0;

  /**

   * \param device device to add to the list of ipv4 interfaces

   *        which can be used as output interfaces during packet forwarding.

   * \returns the index of the ipv4 interface added.

   *

   * Once a device has been added, it can never be removed: if you want

   * to disable it, you can invoke Ipv4::SetDown which will

   * make sure that it is never used during packet forwarding.

   */

  virtual uint32_t AddInterface (Ptr<NetDevice> device) = 0;

  /**

   * \returns the number of interfaces added by the user.

   */

  virtual uint32_t GetNInterfaces (void) = 0;  

  /**

   * \brief Find and return the interface ID of the interface that has been

   *        assigned the specified IP address.

   * \param addr The IP address assigned to the interface of interest.

   * \returns The index of the ipv4 interface with the given address.

   *

   * Each IP interface has an IP address associated with it.  It is often 

   * useful to search the list of interfaces for one that corresponds to 

   * a known IP Address.  This call takes an IP address as a parameter and

   * returns the interface index of the first interface that has been assigned

   * that address.  If the address is not found, this function asserts.

   */

  virtual uint32_t FindInterfaceForAddr (Ipv4Address addr) const = 0;

  /**

   * \brief Find and return the interface ID of the interface that has been

   *        assigned the specified (masked) IP address.

   * \param addr The IP address assigned to the interface of interest.

   * \param mask The address mask to be used in address matching.

   * \returns The index of the ipv4 interface with the given address.

   *

   * Each IP interface has an IP address associated with it.  It is often 

   * useful to search the list of interfaces for one that corresponds to 

   * a known IP Address.  This call takes an IP address and an IP address

   * mask as parameters and returns the interface index of the first interface

   * that matches the masked IP address.

   */

  virtual uint32_t FindInterfaceForAddr (Ipv4Address addr, 

    Ipv4Mask mask) const = 0;

  /**

   * \param i index of ipv4 interface

   * \returns the NetDevice associated with the ipv4 interface index

   */

  virtual Ptr<NetDevice> GetNetDevice (uint32_t i) = 0;

  /**

   * \brief Join a multicast group for a given multicast source and 

   *        group.

   *

   * \param origin The Ipv4 address of the multicast source.

   * \param group The multicast group address.

   */

  virtual void JoinMulticastGroup (Ipv4Address origin, Ipv4Address group) = 0;

  /**

   * \brief Leave a multicast group for a given multicast source and 

   *        group.

   *

   * \param origin The Ipv4 address of the multicast source.

   * \param group The multicast group address.

   */

  virtual void LeaveMulticastGroup (Ipv4Address origin, Ipv4Address group) = 0;

  /**

   * \param i index of ipv4 interface

   * \param address address to associate to the underlying ipv4 interface

   */

  virtual void SetAddress (uint32_t i, Ipv4Address address) = 0;

  /**

   * \param i index of ipv4 interface

   * \param mask mask to associate to the underlying ipv4 interface

   */

  virtual void SetNetworkMask (uint32_t i, Ipv4Mask mask) = 0;

  /**

   * \param i index of ipv4 interface

   * \returns the mask associated to the underlying ipv4 interface

   */

  virtual Ipv4Mask GetNetworkMask (uint32_t i) const = 0;

  /**

   * \param i index of ipv4 interface

   * \returns the address associated to the underlying ipv4 interface

   */

  virtual Ipv4Address GetAddress (uint32_t i) const = 0;

  /**

   * \param destination The IP address of a hypothetical destination.

   * \returns The IP address assigned to the interface that will be used

   * if we were to send a packet to destination.

   */

  virtual Ipv4Address GetSourceAddress (Ipv4Address destination) const = 0;

  /**

   * \param destination The IP address of a hypothetical destination.

   * \param ifIndex filled in with the interface index that will be used to

   *        send a packet to the hypothetical destination.

   * \returns True if a single interface can be identified, false otherwise.

   */

  virtual bool GetIfIndexForDestination (Ipv4Address dest,

    uint32_t &ifIndex) const = 0;

  /**

   * \param i index of ipv4 interface

   * \returns the Maximum Transmission Unit (in bytes) associated

   *          to the underlying ipv4 interface

   */

  virtual uint16_t GetMtu (uint32_t i) const = 0;

  /**

   * \param i index of ipv4 interface

   * \returns true if the underlying interface is in the "up" state,

   *          false otherwise.

   */

  virtual bool IsUp (uint32_t i) const = 0;

  /**

   * \param i index of ipv4 interface

   * 

   * Set the interface into the "up" state. In this state, it is

   * considered valid during ipv4 forwarding.

   */

  virtual void SetUp (uint32_t i) = 0;

  /**

   * \param i index of ipv4 interface

   *

   * Set the interface into the "down" state. In this state, it is

   * ignored during ipv4 forwarding.

   */

  virtual void SetDown (uint32_t i) = 0;

/**

 * Convenience functions (Doxygen still needed)

 *

 * Return the ifIndex corresponding to the Ipv4Address provided.

 */

  static uint32_t GetIfIndexByAddress (Ptr<Node> node, Ipv4Address a, 

    Ipv4Mask amask = Ipv4Mask("255.255.255.255"));

  static bool GetRouteToDestination (Ptr<Node> node, Ipv4Route& route, 

    Ipv4Address a, Ipv4Mask amask = Ipv4Mask("255.255.255.255"));

};

} // namespace ns3 

#endif /* IPV4_H */