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

//

// Copyright (c) 2008 University of Washington

//

// 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.

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// 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

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//

#ifndef IPV4_GLOBAL_ROUTING_H

#define IPV4_GLOBAL_ROUTING_H

#include <list>

#include <stdint.h>

#include "ns3/ipv4-address.h"

#include "ns3/ipv4-header.h"

#include "ns3/ptr.h"

#include "ns3/ipv4.h"

#include "ns3/ipv4-routing-protocol.h"

#include "ns3/random-variable.h"

namespace ns3 {

class Packet;

class NetDevice;

class Ipv4Interface;

class Ipv4Address;

class Ipv4Header;

class Ipv4RoutingTableEntry;

class Ipv4MulticastRoutingTableEntry;

class Node;

/**

 * \brief Global routing protocol for IP version 4 stacks.

 *

 * In ns-3 we have the concept of a pluggable routing protocol.  Routing

 * protocols are added to a list maintained by the Ipv4L3Protocol.  Every 

 * stack gets one routing protocol for free -- the Ipv4StaticRouting routing

 * protocol is added in the constructor of the Ipv4L3Protocol (this is the 

 * piece of code that implements the functionality of the IP layer).

 *

 * As an option to running a dynamic routing protocol, a GlobalRouteManager

 * object has been created to allow users to build routes for all participating

 * nodes.  One can think of this object as a "routing oracle"; it has

 * an omniscient view of the topology, and can construct shortest path

 * routes between all pairs of nodes.  These routes must be stored 

 * somewhere in the node, so therefore this class Ipv4GlobalRouting

 * is used as one of the pluggable routing protocols.  It is kept distinct

 * from Ipv4StaticRouting because these routes may be dynamically cleared

 * and rebuilt in the middle of the simulation, while manually entered

 * routes into the Ipv4StaticRouting may need to be kept distinct.

 *

 * This class deals with Ipv4 unicast routes only.

 *

 * \see Ipv4RoutingProtocol

 * \see GlobalRouteManager

 */

class Ipv4GlobalRouting : public Ipv4RoutingProtocol

{

public:

  static TypeId GetTypeId (void);

/**

 * \brief Construct an empty Ipv4GlobalRouting routing protocol,

 *

 * The Ipv4GlobalRouting class supports host and network unicast routes.

 * This method initializes the lists containing these routes to empty.

 *

 * \see Ipv4GlobalRouting

 */

  Ipv4GlobalRouting ();

  virtual ~Ipv4GlobalRouting ();

  // These methods inherited from base class

  virtual Ptr<Ipv4Route> RouteOutput (Ptr<Packet> p, const Ipv4Header &header, Ptr<NetDevice> oif, Socket::SocketErrno &sockerr);

  virtual bool RouteInput  (Ptr<const Packet> p, const Ipv4Header &header, Ptr<const NetDevice> idev,

                             UnicastForwardCallback ucb, MulticastForwardCallback mcb,

                             LocalDeliverCallback lcb, ErrorCallback ecb);

  virtual void NotifyInterfaceUp (uint32_t interface);

  virtual void NotifyInterfaceDown (uint32_t interface);

  virtual void NotifyAddAddress (uint32_t interface, Ipv4InterfaceAddress address);

  virtual void NotifyRemoveAddress (uint32_t interface, Ipv4InterfaceAddress address);

  virtual void SetIpv4 (Ptr<Ipv4> ipv4);

/**

 * \brief Add a host route to the global routing table.

 *

 * \param dest The Ipv4Address destination for this route.

 * \param nextHop The Ipv4Address of the next hop in the route.

 * \param interface The network interface index used to send packets to the

 * destination.

 *

 * \see Ipv4Address

 */

  void AddHostRouteTo (Ipv4Address dest, 

                       Ipv4Address nextHop, 

                       uint32_t interface);

/**

 * \brief Add a host route to the global routing table.

 *

 * \param dest The Ipv4Address destination for this route.

 * \param interface The network interface index used to send packets to the

 * destination.

 *

 * \see Ipv4Address

 */

  void AddHostRouteTo (Ipv4Address dest, 

                       uint32_t interface);

/**

 * \brief Add a network route to the global routing table.

 *

 * \param network The Ipv4Address network for this route.

 * \param networkMask The Ipv4Mask to extract the network.

 * \param nextHop The next hop in the route to the destination network.

 * \param interface The network interface index used to send packets to the

 * destination.

 *

 * \see Ipv4Address

 */

  void AddNetworkRouteTo (Ipv4Address network, 

                          Ipv4Mask networkMask, 

                          Ipv4Address nextHop, 

                          uint32_t interface);

/**

 * \brief Add a network route to the global routing table.

 *

 * \param network The Ipv4Address network for this route.

 * \param networkMask The Ipv4Mask to extract the network.

 * \param interface The network interface index used to send packets to the

 * destination.

 *

 * \see Ipv4Address

 */

  void AddNetworkRouteTo (Ipv4Address network, 

                          Ipv4Mask networkMask, 

                          uint32_t interface);

/**

 * \brief Add an external route to the global routing table.

 *

 * \param network The Ipv4Address network for this route.

 * \param networkMask The Ipv4Mask to extract the network.

 * \param nextHop The next hop Ipv4Address

 * \param interface The network interface index used to send packets to the

 * destination.

 */

  void AddASExternalRouteTo (Ipv4Address network,

                             Ipv4Mask networkMask,

                             Ipv4Address nextHop,

                             uint32_t interface);

/**

 * \brief Get the number of individual unicast routes that have been added

 * to the routing table.

 *

 * \warning The default route counts as one of the routes.

 */

/**

 * \brief Get a route from the global unicast routing table.

 *

 * Externally, the unicast global routing table appears simply as a table with

 * n entries.  The one subtlety of note is that if a default route has been set

 * it will appear as the zeroth entry in the table.  This means that if you

 * add only a default route, the table will have one entry that can be accessed

 * either by explicitly calling GetDefaultRoute () or by calling GetRoute (0).

 * 

 * Similarly, if the default route has been set, calling RemoveRoute (0) will

 * remove the default route.

 *

 * \param i The index (into the routing table) of the route to retrieve.  If

 * the default route has been set, it will occupy index zero.

 * \return If route is set, a pointer to that Ipv4RoutingTableEntry is returned, otherwise

 * a zero pointer is returned.

 *

 * \see Ipv4RoutingTableEntry

 * \see Ipv4GlobalRouting::RemoveRoute

 */

/**

 * \brief Remove a route from the global unicast routing table.

 *

 * Externally, the unicast global routing table appears simply as a table with

 * n entries.  The one subtlety of note is that if a default route has been set

 * it will appear as the zeroth entry in the table.  This means that if the

 * default route has been set, calling RemoveRoute (0) will remove the

 * default route.

 *

 * \param i The index (into the routing table) of the route to remove.  If

 * the default route has been set, it will occupy index zero.

 *

 * \see Ipv4RoutingTableEntry

 * \see Ipv4GlobalRouting::GetRoute

 * \see Ipv4GlobalRouting::AddRoute

 */

  void RemoveRoute (uint32_t i);

protected:

  void DoDispose (void);

private:

  /// Set to true if packets are randomly routed among ECMP; set to false for using only one route consistently

  bool m_randomEcmpRouting;

  /// Set to true if this interface should respond to interface events by globallly recomputing routes 

  bool m_respondToInterfaceEvents;

  /// A uniform random number generator for randomly routing packets among ECMP 

  UniformVariable m_rand;

  typedef std::list<Ipv4RoutingTableEntry *> HostRoutes;

  typedef std::list<Ipv4RoutingTableEntry *>::const_iterator HostRoutesCI;

  typedef std::list<Ipv4RoutingTableEntry *>::iterator HostRoutesI;

  typedef std::list<Ipv4RoutingTableEntry *> NetworkRoutes;

  typedef std::list<Ipv4RoutingTableEntry *>::const_iterator NetworkRoutesCI;

  typedef std::list<Ipv4RoutingTableEntry *>::iterator NetworkRoutesI;

  typedef std::list<Ipv4RoutingTableEntry *> ASExternalRoutes;

  typedef std::list<Ipv4RoutingTableEntry *>::const_iterator ASExternalRoutesCI;

  typedef std::list<Ipv4RoutingTableEntry *>::iterator ASExternalRoutesI;

  Ptr<Ipv4Route> LookupGlobal (Ipv4Address dest, Ptr<NetDevice> oif = 0);

  HostRoutes m_hostRoutes;

  NetworkRoutes m_networkRoutes;

  ASExternalRoutes m_ASexternalRoutes; // External routes imported

  Ptr<Ipv4> m_ipv4;

};

} // Namespace ns3

#endif /* IPV4_GLOBAL_ROUTING_H */