// -*- 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.
//
// 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
//
//
#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"
namespace ns3 {
class Packet;
class NetDevice;
class Ipv4Interface;
class Ipv4Address;
class Ipv4Header;
class Ipv4Route;
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 ();
/**
* @brief Request that a check for a route bw performed and if a route is found
* that the packet be sent on its way using the pre-packaged send callback.
*
* The source and destination IP addresses for the packet in question are found
* in the provided Ipv4Header. There are two major processing forks depending
* on the type of destination address.
*
* If the destination address is unicast then the routing table is consulted
* for a route to the destination and if it is found, the routeReply callback
* is executed to send the packet (with the found route).
*
* If the destination address is a multicast, then the method will return
* false.
*
* @param interface The network interface index over which the packed was
* received. If the packet is from a local source, interface will be set to
* Ipv4RoutingProtocol::INTERFACE_INDEX_ANY.
* @param ipHeader the Ipv4Header containing the source and destination IP
* addresses for the packet.
* @param packet The packet to be sent if a route is found.
* @param routeReply A callback that packaged up the call to actually send the
* packet.
* @return Returns true if a route is found and the packet has been sent,
* otherwise returns false indicating that the next routing protocol should
* be consulted.
*
* @see Ipv4GlobalRouting
* @see Ipv4RoutingProtocol
*/
virtual bool RequestRoute (uint32_t interface,
Ipv4Header const &ipHeader,
Ptr<Packet> packet,
RouteReplyCallback routeReply);
/**
* @brief 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.
*
* If there are multiple paths out of the node, the resolution is performed
* by Ipv4L3Protocol::GetInterfaceforDestination which has access to more
* contextual information that is useful for making a determination.
*
* This method will return false on a multicast address.
*
* @param destination The Ipv4Address if the destination of a hypothetical
* packet. This may be a multicast group address.
* @param interface 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 returns false indicating that
* the next routing protocol should be consulted.
*
* @see Ipv4GlobalRouting
* @see Ipv4RoutingProtocol
* @see Ipv4L3Protocol
*/
virtual bool RequestInterface (Ipv4Address destination, uint32_t& interface);
/**
* @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 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.
*/
uint32_t GetNRoutes (void);
/**
* @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 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 Ipv4Route is returned, otherwise
* a zero pointer is returned.
*
* @see Ipv4Route
* @see Ipv4GlobalRouting::RemoveRoute
*/
Ipv4Route *GetRoute (uint32_t i);
/**
* @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 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 Ipv4Route
* @see Ipv4GlobalRouting::GetRoute
* @see Ipv4GlobalRouting::AddRoute
*/
void RemoveRoute (uint32_t i);
protected:
void DoDispose (void);
private:
typedef std::list<Ipv4Route *> HostRoutes;
typedef std::list<Ipv4Route *>::const_iterator HostRoutesCI;
typedef std::list<Ipv4Route *>::iterator HostRoutesI;
typedef std::list<Ipv4Route *> NetworkRoutes;
typedef std::list<Ipv4Route *>::const_iterator NetworkRoutesCI;
typedef std::list<Ipv4Route *>::iterator NetworkRoutesI;
Ipv4Route *LookupGlobal (Ipv4Address dest);
HostRoutes m_hostRoutes;
NetworkRoutes m_networkRoutes;
};
} // Namespace ns3
#endif /* IPV4_GLOBAL_ROUTING_H */