Source: ../../contrib/olsr/external.hh
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// -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-
// vim:set sts=4 ts=8 sw=4:
// Copyright (c) 2001-2009 XORP, Inc.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, Version 2, June
// 1991 as published by the Free Software Foundation. Redistribution
// and/or modification of this program under the terms of any other
// version of the GNU General Public License is not permitted.
//
// 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. For more details,
// see the GNU General Public License, Version 2, a copy of which can be
// found in the XORP LICENSE.gpl file.
//
// XORP Inc, 2953 Bunker Hill Lane, Suite 204, Santa Clara, CA 95054, USA;
// http://xorp.net
// $XORP: xorp/contrib/olsr/external.hh,v 1.4 2009/01/05 18:30:46 jtc Exp $
#ifndef __OLSR_EXTERNAL_HH__
#define __OLSR_EXTERNAL_HH__
class ExternalRoute;
class ExternalRoutes;
class RouteManager;
/**
* @short Orders a sequence of OlsrTypes::ExternalID in descending
* order of preference for route selection.
*
* Model of StrictWeakOrdering.
*/
struct ExternalRouteOrderPred {
ExternalRoutes& _ers;
inline ExternalRouteOrderPred(ExternalRoutes& ers) : _ers(ers) {}
/**
* Functor to: implement collation order on external route maps.
*
* 12.6: The distance to the last-hop, as measured from the HNA
* message, is used as the current discriminator; this is what's
* specified in the RFC.
*
* Because identifiers for these structures are normally passed around
* rather than the pointers themselves, it is necessary to use a functor.
*
* Collation order:
* 1. Network destination, as per IPvXNet.
* 2. If not self originated, distance in ascending order.
*
* @param lhid the ID of the external route on the left-hand side.
* @param rhid the ID of the external route on the right-hand side.
* @return true if lhid comes before rhid.
*/
bool operator()(const OlsrTypes::ExternalID lhid,
const OlsrTypes::ExternalID rhid);
};
/**
* @short Class which manages distribution of external routes
* throughout the OLSR domain.
*/
class ExternalRoutes {
public:
ExternalRoutes(Olsr& olsr, EventLoop& eventloop,
FaceManager& fm, Neighborhood& nh);
~ExternalRoutes();
//
// Accessors/mutators.
//
FaceManager& face_manager() { return _fm; }
inline RouteManager* route_manager() { return _rm; }
inline void set_route_manager(RouteManager* rm) { _rm = rm; }
//
// HNA protocol variables.
//
inline TimeVal get_hna_interval() const { return _hna_interval; }
/**
* Set the HNA send timer.
*
* @param hna_interval the interval between HNA advertisements.
*
* The timer will only be restarted if previously scheduled. If the
* period of the HNA broadcasts is changed, a HNA broadcast MAY be
* scheduled to take place immediately.
*/
void set_hna_interval(const TimeVal& hna_interval);
inline TimeVal get_hna_hold_time() const {
return 3 * get_hna_interval();
}
//
// HNA routes in.
//
/**
* Update or create a route entry learned from HNA.
*
* If the origin of the HNA route is not reachable in the OLSR SPT,
* the route will be rejected; see NOTES.
* TODO: In future distance may also be treated as an advertised metric.
*
* @param dest The destination being updated.
* @param lasthop The last-hop to reach the destination.
* @param distance the number of hops to reach lasthop.
* @param expiry_time The time at which the entry will expire.
* @param is_created reference to a boolean which is set to true
* iff a new entry was created by this method.
*
* @return The ID of the created or updated route entry.
* @throw BadExternalRoute if the route could not be created.
*/
OlsrTypes::ExternalID update_hna_route_in(const IPv4Net& dest,
const IPv4& lasthop,
const uint16_t distance,
const TimeVal& expiry_time,
bool& is_created)
throw(BadExternalRoute);
/**
* Create a route entry learned from HNA.
*
* @param dest The destination being updated.
* @param lasthop The last-hop to reach the destination;
* usually this is the origin of the route.
* @param distance the number of hops to reach lasthop.
* @param expiry_time The time at which the entry will expire.
*
* @return The ID of the created route entry.
* @throw BadExternalRoute if the route could not be created.
*/
OlsrTypes::ExternalID add_hna_route_in(const IPv4Net& dest,
const IPv4& lasthop,
const uint16_t distance,
const TimeVal& expiry_time)
throw(BadExternalRoute);
/**
* Delete an HNA learned route entry given its ID.
*
* @param erid The ID of the external route to delete.
* @return true if the entry was found and deleted.
*/
bool delete_hna_route_in(OlsrTypes::ExternalID erid);
/**
* Clear the learned HNA routes.
*/
void clear_hna_routes_in();
/**
* Look up an ExternalRoute learned from HNA, given its origin and
* destination network prefix.
*
* @param dest the destination network prefix.
* @param lasthop the origin.
* @return pointer to the ExternalRoute.
* @throw BadExternalRoute if the route could not be found.
*/
const ExternalRoute* get_hna_route_in(const IPv4Net& dest,
const IPv4& lasthop)
throw(BadExternalRoute);
/**
* Look up the ID of a learned HNA entry.
* Both the destination and the OLSR last-hop must be specified to match.
*
* @param dest The destination address.
* @param lasthop The last-hop advertised for the destination.
*
* @return the ID of the learned external route.
* @throw BadExternalRoute if the route could not be found.
*/
OlsrTypes::ExternalID get_hna_route_in_id(const IPv4Net& dest,
const IPv4& lasthop)
throw(BadExternalRoute);
/**
* Look up a learned HNA route entry by its ID.
*
* @param erid the ID of the learned ExternalRoute.
* @return the pointer to the learned ExternalRoute.
* @throw BadExternalRoute if the route could not be found.
*/
const ExternalRoute* get_hna_route_in_by_id(
const OlsrTypes::ExternalID erid)
throw(BadExternalRoute);
/**
* Calculate the number of unique OLSR nodes with HNA entries in this
* node's HNA learned route database.
*
* Used only by the protocol simulator.
*
* As we don't currently maintain a list of origins for HNA, this is
* a more computationally expensive invariant than for TC or MID.
*
* @return the number of unique origins in the HNA route-in map.
*/
size_t hna_origin_count() const;
/**
* Calculate the number of unique HNA prefixes which have been learned.
*
* Used only by the protocol simulator.
*
* @return the number of unique destinations in the HNA route-in map.
*/
size_t hna_dest_count() const;
/**
* @return the number of entries in the learned HNA route database.
*/
inline size_t hna_entry_count() const {
return _routes_in.size();
}
/**
* Fill out a list of all the external learned route IDs.
*
* @param hnalist the list to fill out.
*/
void get_hna_route_in_list(list<OlsrTypes::ExternalID>& hnalist);
//
// HNA routes out.
//
/**
* Originate an HNA route.
*
* @param dest the network for which to originate HNA broadcasts.
* @return true if the route was originated successfully.
* @throw BadExternalRoute if the route could not be originated.
*/
bool originate_hna_route_out(const IPv4Net& dest)
throw(BadExternalRoute);
/**
* Withdraw an HNA route.
*
* @param dest the network to withdraw from HNA broadcasts.
* @throw BadExternalRoute if no route to the given destination
* could be found.
*/
void withdraw_hna_route_out(const IPv4Net& dest)
throw(BadExternalRoute);
/**
* Clear the advertised HNA routes.
*/
void clear_hna_routes_out();
/**
* Look up the ID of an originated HNA entry.
* Both the destination and the OLSR last-hop must be specified to match.
*
* @param dest The destination address.
* @return the ID of the originated external route.
* @throw BadExternalRoute if the route could not be found.
*/
OlsrTypes::ExternalID get_hna_route_out_id(const IPv4Net& dest)
throw(BadExternalRoute);
//
// RouteManager interaction.
//
/**
* Push candidate HNA routes to the RouteManager.
*
* 12.6: The distance to the last-hop, as measured from the HNA
* message, is used as the current discriminator; this is what's
* specified in the RFC.
*
* TODO: Deal with the metric here rather than in the RouteManager.
* For now, RouteManager will invent a metric before plumbing to the RIB.
*/
void push_external_routes();
//
// HNA transmission timer.
//
void start_hna_send_timer();
void stop_hna_send_timer();
void restart_hna_send_timer();
/**
* Reschedule the HNA send timer (if the HNA interval has changed).
*/
void reschedule_hna_send_timer();
/**
* Schedule the HNA send timer to fire as soon as possible.
*/
void reschedule_immediate_hna_send_timer();
//
// Event handlers.
//
/**
* Callback method to: service the HNA transmission timer.
* Section 12: Non-OLSR Interfaces.
*
* Flood a HNA message to the rest of the OLSR domain
* which contains this node's Host and Network Associations.
*
* @return true if the callback should be rescheduled, otherwise false.
*/
bool event_send_hna();
/**
* Process incoming HNA message.
* Section 12.5: HNA Message Processing.
*
* @param msg the message to process.
* @param remote_addr the source address of the Packet containing msg.
* @param local_addr the address of the OLSR interface where the
* Packet containing msg was received.
* @return true if msg was consumed by this method, otherwise false.
*/
bool event_receive_hna(Message* msg,
const IPv4& remote_addr,
const IPv4& local_addr);
/**
* Callback method to: delete a learned route entry when it expires.
*
* @param erid The ID of the external route to delete.
*/
void event_hna_route_in_expired(const OlsrTypes::ExternalID erid);
private:
Olsr& _olsr;
EventLoop& _eventloop;
FaceManager& _fm;
Neighborhood& _nh;
RouteManager* _rm;
ExternalRouteOrderPred _routes_in_order_pred;
bool _is_early_hna_enabled;
OlsrTypes::ExternalID _next_erid;
/**
* @short the interval at which HNA broadcasts are flooded
* throughout the OLSR domain by this node, if routes are originated.
*/
TimeVal _hna_interval;
XorpTimer _hna_send_timer;
/**
* @short Map of learned routes by destination to route ID
* covering that destination.
*/
typedef multimap<IPv4Net, OlsrTypes::ExternalID> ExternalDestInMap;
ExternalDestInMap _routes_in_by_dest;
/**
* @short HNA entries learned by this node.
*/
typedef map<OlsrTypes::ExternalID, ExternalRoute*> ExternalRouteMap;
ExternalRouteMap _routes_in;
/**
* @short Map of originated route IDs by destination.
*/
typedef map<IPv4Net, OlsrTypes::ExternalID> ExternalDestOutMap;
ExternalDestOutMap _routes_out_by_dest;
/**
* @short HNA entries originated by this node.
*/
ExternalRouteMap _routes_out;
};
/**
* @short Class representing an external route entry,
* either learned or originated in the OLSRv1 HNA sub-protocol.
*/
class ExternalRoute {
public:
/**
* Constructor for a external route learned from another OLSR peer.
*/
explicit ExternalRoute(ExternalRoutes& parent,
EventLoop& ev,
const OlsrTypes::ExternalID erid,
const IPv4Net& dest,
const IPv4& lasthop,
const uint16_t distance,
const TimeVal& expiry_time)
: _parent(parent),
_eventloop(ev),
_id(erid),
_is_self_originated(false),
_dest(dest),
_lasthop(lasthop),
_distance(distance)
{
update_timer(expiry_time);
}
/**
* Constructor for a external route originated by this node.
*/
explicit ExternalRoute(ExternalRoutes& parent,
EventLoop& ev,
const OlsrTypes::ExternalID erid,
const IPv4Net& dest)
: _parent(parent),
_eventloop(ev),
_id(erid),
_is_self_originated(true),
_dest(dest),
_distance(0)
{
}
virtual ~ExternalRoute() {}
/**
* @return the ID of the external route.
*/
inline OlsrTypes::ExternalID id() const { return _id; }
/**
* @return true if we are the node which originated this route.
*/
inline bool is_self_originated() const { return _is_self_originated; }
/**
* @return the destination of this route.
*/
inline IPv4Net dest() const { return _dest; }
/**
* @return the node in the OLSR topology which advertised the
* destination which this route points to.
*/
inline IPv4 lasthop() const { return _lasthop; }
/**
* @return the number of hops between this node and the last hop.
*/
inline uint16_t distance() const { return _distance; }
/**
* Update the distance in hops between this node and the last hop.
*/
inline void set_distance(const uint16_t distance) {
_distance = distance;
}
/**
* @return the amount of time remaining until this HNA entry expires.
*/
inline TimeVal time_remaining() const {
TimeVal tv;
_expiry_timer.time_remaining(tv);
return tv;
}
/**
* Schedule or re-schedule the expiry timer on this route entry.
*
* @param expiry_time The new expiry time of the route entry.
*/
void update_timer(const TimeVal& expiry_time);
/**
* Callback method to: request that the parent delete this HNA
* derived external route, as it has now expired.
*/
void event_expired();
private:
ExternalRoutes& _parent;
EventLoop& _eventloop;
OlsrTypes::ExternalID _id;
/**
* true if this ExternalRoute is being originated by this
* node and was not learned from another node, otherwise false.
*/
bool _is_self_originated;
/**
* The A_network_addr/A_netmask protocol variable.
*/
IPv4Net _dest;
/**
* The A_gateway_addr protocol variable.
*/
IPv4 _lasthop;
/**
* The A_time protocol variable.
*/
XorpTimer _expiry_timer;
/**
* The number of hops recorded between this node and the lasthop,
* as seen in the most recent HNA message containing this prefix.
*/
uint16_t _distance;
};
#endif // __OLSR_EXTERNAL_HH__
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