Source: ../../rib/route.hh
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// -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-
// Copyright (c) 2001-2004 International Computer Science Institute
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software")
// to deal in the Software without restriction, subject to the conditions
// listed in the XORP LICENSE file. These conditions include: you must
// preserve this copyright notice, and you cannot mention the copyright
// holders in advertising related to the Software without their permission.
// The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
// notice is a summary of the XORP LICENSE file; the license in that file is
// legally binding.
// $XORP: xorp/rib/route.hh,v 1.13 2004/06/10 22:41:39 hodson Exp $
#ifndef __RIB_ROUTE_HH__
#define __RIB_ROUTE_HH__
#include <set>
#include <map>
#include "libxorp/xorp.h"
#include "libxorp/ipv4net.hh"
#include "libxorp/ipv6net.hh"
#include "libxorp/vif.hh"
#include "libxorp/nexthop.hh"
#include "protocol.hh"
/**
* @short Base class for RIB routing table entries.
*
* This is the base class from which RIB routing table entries are derived.
* It's not useful by itself.
*/
class RouteEntry {
public:
/**
* Constructor for a route entry.
*
* @param vif the Virtual Interface on which packets matching this
* routing table entry should be forwarded.
* @param nexthop the NextHop router to which packets matching this
* entry should be forwarded.
* @param protocol the routing protocol that originated this route.
* @param metric the routing protocol metric for this route.
*/
RouteEntry(Vif* vif, NextHop* nexthop, const Protocol& protocol,
uint16_t metric)
: _vif(vif), _nexthop(nexthop), _protocol(protocol),
_admin_distance(255), _metric(metric)
{
}
/**
* Destructor
*/
virtual ~RouteEntry() {}
/**
* Get the VIF.
*
* @return the Virtual Interface on which packets matching this
* routing table entry should be forwarded.
*/
inline Vif* vif() const { return _vif; }
/**
* Get the NextHop router.
*
* @return the NextHop router to which packets matching this
* entry should be forwarded.
*/
inline NextHop* nexthop() const { return _nexthop; }
/**
* Set the NextHop router.
*
* @param v the NextHop router to be set on this route.
*/
inline void set_nexthop(NextHop* v) { _nexthop = v; }
/**
* Get the Administrative Distance.
*
* @return the Administrative Distance associated with this route.
* Admin Distance is a parameter typically assigned on a
* per-routing-protocol basis. When two routes for the same
* subnet come from different routing protocols, the one with the
* lower admin distance is prefered.
*/
inline uint16_t admin_distance() const { return _admin_distance; }
/**
* Set the Administrative Distance.
*
* @param ad the administrative distance to apply to this route.
*/
inline void set_admin_distance(uint16_t ad) { _admin_distance = ad; }
/**
* Get the routing protocol.
*
* @return the routing protocol that originated this route.
* @see Protocol.
*/
inline const Protocol& protocol() const { return _protocol; }
/**
* Display the route for debugging purposes.
*/
virtual string str() const = 0;
/**
* Set the routing protocol metric on this route.
*
* @param metric the routing protocol metric to be set on this route.
*/
inline void set_metric(uint16_t metric) { _metric = metric; }
/**
* Get the routing protocol metric.
*
* @return the routing protocol metric for this route.
*/
inline uint32_t metric() const { return _metric; }
protected:
Vif* _vif;
NextHop* _nexthop; // The next-hop router
// The routing protocol that instantiated this route
const Protocol& _protocol;
uint16_t _admin_distance; // Lower is better
uint16_t _metric; // Lower is better
};
/**
* @short Routing Table Entry
*
* This class stores a regular RIB routing table entry for either an
* IPv4 or an IPv6 route. It is a template class, where A is either a
* the IPv4 class or the IPv6 class.
*/
template <class A>
class IPRouteEntry : public RouteEntry {
public:
/**
* Constructor for IPRouteEntry.
*
* @param net the Subnet (address and mask) of the routing table entry.
* @param vif the Virtual Interface on which packets matching this
* routing table entry should be forwarded.
* @param nexthop the NextHop router to which packets matching this
* entry should be forwarded.
* @param protocol the routing protocol that originated this route.
* @param metric the routing protocol metric for this route.
*/
IPRouteEntry(const IPNet<A>& net, Vif* vif, NextHop* nexthop,
const Protocol& protocol, uint16_t metric)
: RouteEntry(vif, nexthop, protocol, metric), _net(net) {}
/**
* Destructor for Routing Table Entry
*/
~IPRouteEntry() {}
/**
* Get the route entry's subnet addres.
*
* @return the route entry's subnet address.
*/
inline const IPNet<A>& net() const { return _net; }
/**
* Get the prefix length of the route entry's subnet address.
*
* @return the prefix length (in bits) of the route entry's subnet address.
*/
inline size_t prefix_len() const { return _net.prefix_len(); }
/**
* Get the route entry's next-hop router address.
*
* @return the route entry's next-hop router address. If there is no
* next-hop router, then the return value is IPv4#ZERO() or IPv6#ZERO().
*/
inline const A& nexthop_addr() const {
IPNextHop<A>* nh = reinterpret_cast<IPNextHop<A>* >(nexthop());
if (nh != NULL)
return nh->addr();
else {
return A::ZERO();
}
}
/**
* Get the route entry as a string for debugging purposes.
*
* @return a human readable representation of the route entry.
*/
string str() const {
string dst = (_net.is_valid()) ? _net.str() : string("NULL");
string vif = (_vif) ? string(_vif->name()) : string("NULL");
return string("Dst: ") + dst + string(" Vif: ") + vif +
string(" NextHop: ") + _nexthop->str() + string(" Metric: ") +
c_format("%d", _metric);
}
protected:
IPNet<A> _net; // The route entry's subnet address
};
typedef IPRouteEntry<IPv4> IPv4RouteEntry;
typedef IPRouteEntry<IPv6> IPv6RouteEntry;
/**
* @short Extended RouteEntry, used by ExtIntTable.
*
* This class stored an extended routing table entry, for use in
* ExtIntTable. When a route with a non-local nexthop arrives, the
* ExtIntTable attempts to discover a local nexthop by finding the
* route that packets to the non-local nexthop would use. This entry
* is used to store the resulting route, with a local nexthop, and
* with links to the parent routes that were used to provide the
* information in this route entry.
*
* This is a template class, where A is either a the IPv4 class or the
* IPv6 class.
*/
template <class A>
class ResolvedIPRouteEntry : public IPRouteEntry<A> {
public:
typedef multimap<const IPRouteEntry<A>* , ResolvedIPRouteEntry<A>* > RouteBackLink;
public:
/**
* Constructor for IPRouteEntry.
*
* @param net the Subnet (address and mask) of the routing table entry.
* @param vif the Virtual Interface on which packets matching this
* routing table entry should be forwarded.
* @param nexthop the NextHop router to which packets matching this
* entry should be forwarded. This should be a local nexthop.
* @param protocol the routing protocol that originated this route.
* @param metric the routing protocol metric for this route.
* @param igp_parent the route entry used to resolve the non-local
* nexthop in the egp_parent into a local nexthop.
* @param egp_parent the orginal route entry with a non-local nexthop.
*/
ResolvedIPRouteEntry(const IPNet<A>& net, Vif* vif, NextHop* nexthop,
const Protocol& protocol, uint16_t metric,
const IPRouteEntry<A>* igp_parent,
const IPRouteEntry<A>* egp_parent)
: IPRouteEntry<A>(net, vif, nexthop, protocol, metric),
_igp_parent(igp_parent),
_egp_parent(egp_parent) { }
/**
* Get the igp_parent.
*
* @return the IGP parent route entry that was used to resolve the
* EGP parent route entry's non-local nexthop into a local nexthop.
*/
inline const IPRouteEntry<A>* igp_parent() const { return _igp_parent; }
/**
* Get the EGP parent.
*
* @return the EGP parent, which is the original route entry that
* had a non-local nexthop.
*/
inline const IPRouteEntry<A>* egp_parent() const { return _egp_parent; }
/**
* Set the backlink. When a resolved route is created, the
* ExtIntTable will store a link to it in a multimap that is
* indexed by the IGP parent. This will allow all the routes
* affected by a change in the IGP parent to be found easily.
* However, if the EGP parent goes away, we need to remove the
* links from this multimap, and the backlink provides an iterator
* into the multimap that makes this operation very efficient.
*
* @param backlink the ExtIntTable multimap iterator for this route.
*/
inline void set_backlink(typename RouteBackLink::iterator v);
/**
* Get the backlink.
* @see ResolvedIPRouteEntry<A>::set_backlink
*
* @return the backlink iterator.
*/
inline typename RouteBackLink::iterator backlink() const;
private:
mutable const IPRouteEntry<A>* _igp_parent;
mutable const IPRouteEntry<A>* _egp_parent;
// _backlink is used for removing the corresponding entry from the
// RouteTable's map that is indexed by igp_parent. Without it,
// route deletion would be expensive.
typename RouteBackLink::iterator _backlink;
};
template <typename A>
inline void
ResolvedIPRouteEntry<A>::set_backlink(typename RouteBackLink::iterator v)
{
_backlink = v;
}
template <typename A>
inline typename ResolvedIPRouteEntry<A>::RouteBackLink::iterator
ResolvedIPRouteEntry<A>::backlink() const
{
return _backlink;
}
typedef ResolvedIPRouteEntry<IPv4> ResolvedIPv4RouteEntry;
typedef ResolvedIPRouteEntry<IPv6> ResolvedIPv6RouteEntry;
#endif // __RIB_ROUTE_HH__
Generated by: pavlin on possum.icir.org on Thu Jul 8 23:48:37 2004, using kdoc $.
