/* -*-  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>

 *         Gustavo Carneiro <gjc@inescporto.pt>

 */

#ifndef IPV4_STATIC_ROUTING_H

#define IPV4_STATIC_ROUTING_H

#include <list>

#include <stdint.h>

#include "ns3/ipv4-address.h"

#include "ns3/ipv4-header.h"

#include "ns3/socket.h"

#include "ns3/ptr.h"

#include "ns3/ipv4.h"

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

namespace ns3 {

class Packet;

class NetDevice;

class Ipv4Interface;

class Ipv4Address;

class Ipv4Header;

class Node;

class Ipv4RoutingTableEntry;

class Ipv4MulticastRoutingTableEntry;

/**

 * 

 * \brief Static 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).

 *

 * The Ipv4StaticRouting class inherits from the abstract base class 

 * Ipv4RoutingProtocol that defines the interface methods that a routing 

 * protocol must support.

 *

 * When a packet arrives in the Ipv4L3Protocol for transmission, it comes

 * either from a local source via Ipv4L3Protocol::Send or from a remote 

 * source via Ipv4L3Protocol::Forwarding.  In both cases, a function is called

 * (Ipv4L3Protocol::Lookup) to look up the routing information for the packet.

 *

 * The lookup function iterates through the list of routing protocols asking

 * each to see if it can find a route and send the packet.  A callback is 

 * provided during each of these calls that should be considered a pre-

 * packaged send call.  This is done to allow asynchronous calls into 

 * routing subsystems in order to support on-demand routing, for example.  The

 * method for requesting this operation is Ipv4StaticRouting::RequestRoute for

 * the static routing protocol.

 *

 * Each routing protocol is also free to implement its own methods for managing

 * routes which you will find below.  This class manages a set of "static" or

 * manually configured routes for host, network and multicast routes.

 *

 * \see Ipv4RoutingProtocol

 * \see Ipv4L3Protocol::AddRoutingProtocol

 * \see Ipv4L3Protocol::Ipv4L3Protocol

 */

class Ipv4StaticRouting : public Ipv4RoutingProtocol

{

public:

  static TypeId GetTypeId (void);

/**

 * \brief Add a host route to the static 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

 */

  virtual void AddHostRouteTo (Ipv4Address dest, 

                       Ipv4Address nextHop, 

                       uint32_t interface) = 0;

/**

 * \brief Add a host route to the static 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

 */

  virtual void AddHostRouteTo (Ipv4Address dest, uint32_t interface) = 0;

/**

 * \brief Add a network route to the static 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

 */

  virtual void AddNetworkRouteTo (Ipv4Address network, 

                          Ipv4Mask networkMask, 

                          Ipv4Address nextHop, 

                          uint32_t interface) = 0;

/**

 * \brief Add a network route to the static 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

 */

  virtual void AddNetworkRouteTo (Ipv4Address network, 

                          Ipv4Mask networkMask, 

                          uint32_t interface) = 0;

/**

 * \brief Add a default route to the static routing table.

 *

 * This method tells the routing system what to do in the case where a specific

 * route to a destination is not found.  The system forwards packets to the

 * specified node in the hope that it knows better how to route the packet.

 * 

 * If the default route is set, it is returned as the selected route from 

 * LookupStatic irrespective of destination address if no specific route is

 * found.

 *

 * \param nextHop The Ipv4Address to send packets to in the hope that they

 * will be forwarded correctly.

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

 *

 * \see Ipv4Address

 * \see Ipv4StaticRouting::Lookup

 */

  virtual void SetDefaultRoute (Ipv4Address nextHop, uint32_t interface) = 0;

/**

 * \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.

 */

  virtual uint32_t GetNRoutes (void) = 0;

/**

 * \brief Get the default route from the static routing table.

 *

 * \return If the default route is set, a pointer to that Ipv4RoutingTableEntry is

 * returned, otherwise a zero pointer is returned.

 *

 * \see Ipv4RoutingTableEntry

 */

  virtual Ipv4RoutingTableEntry GetDefaultRoute (void) = 0;

/**

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

 *

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

 * n entries.  The one sublety 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 explicity 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 Ipv4StaticRouting::RemoveRoute

 */

  virtual Ipv4RoutingTableEntry GetRoute (uint32_t i) = 0;

/**

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

 *

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

 * n entries.  The one sublety 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 Ipv4StaticRouting::GetRoute

 * \see Ipv4StaticRouting::AddRoute

 */

  virtual void RemoveRoute (uint32_t i) = 0;

/**

 * \brief Add a multicast route to the static routing table.

 *

 * A multicast route must specify an origin IP address, a multicast group and

 * an input network interface index as conditions and provide a vector of

 * output network interface indices over which packets matching the conditions

 * are sent.

 *

 * Typically there are two main types of multicast routes:  routes of the 

 * first kind are used during forwarding.  All of the conditions must be

 * exlicitly provided.  The second kind of routes are used to get packets off

 * of a local node.  The difference is in the input interface.  Routes for

 * forwarding will always have an explicit input interface specified.  Routes

 * off of a node will always set the input interface to a wildcard specified

 * by the index Ipv4RoutingProtocol::INTERFACE_ANY.

 *

 * For routes off of a local node wildcards may be used in the origin and

 * multicast group addresses.  The wildcard used for Ipv4Adresses is that 

 * address returned by Ipv4Address::GetAny () -- typically "0.0.0.0".  Usage

 * of a wildcard allows one to specify default behavior to varying degrees.

 *

 * For example, making the origin address a wildcard, but leaving the 

 * multicast group specific allows one (in the case of a node with multiple

 * interfaces) to create different routes using different output interfaces

 * for each multicast group.

 *

 * If the origin and multicast addresses are made wildcards, you have created

 * essentially a default multicast address that can forward to multiple 

 * interfaces.  Compare this to the actual default multicast address that is

 * limited to specifying a single output interface for compatibility with

 * existing functionality in other systems.

 * 

 * \param origin The Ipv4Address of the origin of packets for this route.  May

 * be Ipv4Address:GetAny for open groups.

 * \param group The Ipv4Address of the multicast group or this route.

 * \param inputInterface The input network interface index over which to 

 * expect packets destined for this route.  May be

 * Ipv4RoutingProtocol::INTERFACE_ANY for packets of local origin.

 * \param outputInterfaces A vector of network interface indices used to specify

 * how to send packets to the destination(s).

 *

 * \see Ipv4Address

 */

  virtual void AddMulticastRoute (Ipv4Address origin,

                          Ipv4Address group,

                          uint32_t inputInterface,

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

/**

 * \brief Add a default multicast route to the static routing table.

 *

 * This is the multicast equivalent of the unicast version SetDefaultRoute.

 * We tell the routing system what to do in the case where a specific route

 * to a destination multicast group is not found.  The system forwards 

 * packets out the specified interface in the hope that "something out there"

 * knows better how to route the packet.  This method is only used in 

 * initially sending packets off of a host.  The default multicast route is

 * not consulted during forwarding -- exact routes must be specified using

 * AddMulticastRoute for that case.

 *

 * Since we're basically sending packets to some entity we think may know

 * better what to do, we don't pay attention to "subtleties" like origin

 * address, nor do we worry about forwarding out multiple  interfaces.  If the

 * default multicast route is set, it is returned as the selected route from 

 * LookupStatic irrespective of origin or multicast group if another specific

 * route is not found.

 *

 * \param outputInterface The network interface index used to specify where

 * to send packets in the case of unknown routes.

 *

 * \see Ipv4Address

 */

  virtual void SetDefaultMulticastRoute (uint32_t outputInterface) = 0;

/**

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

 * to the routing table.

 *

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

 */

  virtual uint32_t GetNMulticastRoutes (void) const = 0;

/**

 * \brief Get a route from the static multicast routing table.

 *

 * Externally, the multicast static routing table appears simply as a table 

 * with n entries.  

 * 

 * \param i The index (into the routing table) of the multicast route to

 * retrieve.  

 * \return If route \e i is set, a pointer to that Ipv4MulticastRoutingTableEntry is

 * returned, otherwise a zero pointer is returned.

 *

 * \see Ipv4MulticastRoutingTableEntry

 * \see Ipv4StaticRouting::RemoveRoute

 */

  virtual Ipv4MulticastRoutingTableEntry GetMulticastRoute (uint32_t i) const = 0;

/**

 * \brief Remove a route from the static multicast routing table.

 *

 * Externally, the multicast static routing table appears simply as a table 

 * with n entries.  

 * This method causes the multicast routing table to be searched for the first

 * route that matches the parameters and removes it.

 *

 * Wildcards may be provided to this function, but the wildcards are used to

 * exacly match wildcards in the routes (see AddMulticastRoute).  That is,

 * calling RemoveMulticastRoute with the origin set to "0.0.0.0" will not

 * remove routes with any address in the origin, but will only remove routes

 * with "0.0.0.0" set as the the origin.

 *

 * \param origin The IP address specified as the origin of packets for the

 * route.

 * \param group The IP address specified as the multicast group addres of

 * the route.

 * \param inputInterface The network interface index specified as the expected

 * input interface for the route.

 * \returns true if a route was found and removed, false otherwise.

 *

 * \see Ipv4MulticastRoutingTableEntry

 * \see Ipv4StaticRouting::AddMulticastRoute

 */

  virtual bool RemoveMulticastRoute (Ipv4Address origin,

                             Ipv4Address group,

                             uint32_t inputInterface) = 0;

/**

 * \brief Remove a route from the static multicast routing table.

 *

 * Externally, the multicast static routing table appears simply as a table 

 * with n entries.  

 *

 * \param index The index (into the multicast routing table) of the route to

 * remove.  

 *

 * \see Ipv4RoutingTableEntry

 * \see Ipv4StaticRouting::GetRoute

 * \see Ipv4StaticRouting::AddRoute

 */

  virtual void RemoveMulticastRoute (uint32_t index) = 0;

  virtual void SetNode (Ptr<Node> node) = 0;

  virtual Ptr<Node> GetNode (void) const = 0;

};

} // Namespace ns3

#endif /* IPV4_STATIC_ROUTING_H */