/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright 2007 University of Washington
* Copyright (C) 1999, 2000 Kunihiro Ishiguro, Toshiaki Takada
*
* 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
*
* Authors: Tom Henderson (tomhend@u.washington.edu)
*
* Kunihiro Ishigura, Toshiaki Takada (GNU Zebra) are attributed authors
* of the quagga 0.99.7/src/ospfd/ospf_spf.c code which was ported here
*/
#include <utility>
#include <vector>
#include <queue>
#include <algorithm>
#include <iostream>
#include "ns3/assert.h"
#include "ns3/fatal-error.h"
#include "ns3/log.h"
#include "ns3/node-list.h"
#include "ns3/ipv4.h"
#include "ns3/ipv4-routing-protocol.h"
#include "ns3/ipv4-list-routing.h"
#include "ns3/mpi-interface.h"
#include "global-router-interface.h"
#include "global-route-manager-impl.h"
#include "candidate-queue.h"
#include "ipv4-global-routing.h"
namespace ns3 {
NS_LOG_COMPONENT_DEFINE ("GlobalRouteManagerImpl");
/**
* \brief Stream insertion operator.
*
* \param os the reference to the output stream
* \param exit the exit node
* \returns the reference to the output stream
*/
std::ostream&
operator<< (std::ostream& os, const SPFVertex::NodeExit_t& exit)
{
os << "(" << exit.first << " ," << exit.second << ")";
return os;
}
std::ostream&
operator<< (std::ostream& os, const SPFVertex::ListOfSPFVertex_t& vs)
{
typedef SPFVertex::ListOfSPFVertex_t::const_iterator CIter_t;
os << "{";
for (CIter_t iter = vs.begin (); iter != vs.end ();)
{
os << (*iter)->m_vertexId;
if (++iter != vs.end ())
{
os << ", ";
}
else
{
break;
}
}
os << "}";
return os;
}
// ---------------------------------------------------------------------------
//
// SPFVertex Implementation
//
// ---------------------------------------------------------------------------
SPFVertex::SPFVertex () :
m_vertexType (VertexUnknown),
m_vertexId ("255.255.255.255"),
m_lsa (0),
m_distanceFromRoot (SPF_INFINITY),
m_rootOif (SPF_INFINITY),
m_nextHop ("0.0.0.0"),
m_parents (),
m_children (),
m_vertexProcessed (false)
{
NS_LOG_FUNCTION (this);
}
SPFVertex::SPFVertex (GlobalRoutingLSA* lsa) :
m_vertexId (lsa->GetLinkStateId ()),
m_lsa (lsa),
m_distanceFromRoot (SPF_INFINITY),
m_rootOif (SPF_INFINITY),
m_nextHop ("0.0.0.0"),
m_parents (),
m_children (),
m_vertexProcessed (false)
{
NS_LOG_FUNCTION (this << lsa);
if (lsa->GetLSType () == GlobalRoutingLSA::RouterLSA)
{
NS_LOG_LOGIC ("Setting m_vertexType to VertexRouter");
m_vertexType = SPFVertex::VertexRouter;
}
else if (lsa->GetLSType () == GlobalRoutingLSA::NetworkLSA)
{
NS_LOG_LOGIC ("Setting m_vertexType to VertexNetwork");
m_vertexType = SPFVertex::VertexNetwork;
}
}
SPFVertex::~SPFVertex ()
{
NS_LOG_FUNCTION (this);
NS_LOG_LOGIC ("Children vertices - " << m_children);
NS_LOG_LOGIC ("Parent verteices - " << m_parents);
// find this node from all its parents and remove the entry of this node
// from all its parents
for (ListOfSPFVertex_t::iterator piter = m_parents.begin ();
piter != m_parents.end ();
piter++)
{
// remove the current vertex from its parent's children list. Check
// if the size of the list is reduced, or the child<->parent relation
// is not bidirectional
uint32_t orgCount = (*piter)->m_children.size ();
(*piter)->m_children.remove (this);
uint32_t newCount = (*piter)->m_children.size ();
if (orgCount > newCount)
{
NS_ASSERT_MSG (orgCount > newCount, "Unable to find the current vertex from its parents --- impossible!");
}
}
// delete children
while (m_children.size () > 0)
{
// pop out children one by one. Some children may disapper
// when deleting some other children in the list. As a result,
// it is necessary to use pop to walk through all children, instead
// of using iterator.
//
// Note that m_children.pop_front () is not necessary as this
// p is removed from the children list when p is deleted
SPFVertex* p = m_children.front ();
// 'p' == 0, this child is already deleted by its other parent
if (p == 0) continue;
NS_LOG_LOGIC ("Parent vertex-" << m_vertexId << " deleting its child vertex-" << p->GetVertexId ());
delete p;
p = 0;
}
m_children.clear ();
// delete parents
m_parents.clear ();
// delete root exit direction
m_ecmpRootExits.clear ();
NS_LOG_LOGIC ("Vertex-" << m_vertexId << " completed deleted");
}
void
SPFVertex::SetVertexType (SPFVertex::VertexType type)
{
NS_LOG_FUNCTION (this << type);
m_vertexType = type;
}
SPFVertex::VertexType
SPFVertex::GetVertexType (void) const
{
NS_LOG_FUNCTION (this);
return m_vertexType;
}
void
SPFVertex::SetVertexId (Ipv4Address id)
{
NS_LOG_FUNCTION (this << id);
m_vertexId = id;
}
Ipv4Address
SPFVertex::GetVertexId (void) const
{
NS_LOG_FUNCTION (this);
return m_vertexId;
}
void
SPFVertex::SetLSA (GlobalRoutingLSA* lsa)
{
NS_LOG_FUNCTION (this << lsa);
m_lsa = lsa;
}
GlobalRoutingLSA*
SPFVertex::GetLSA (void) const
{
NS_LOG_FUNCTION (this);
return m_lsa;
}
void
SPFVertex::SetDistanceFromRoot (uint32_t distance)
{
NS_LOG_FUNCTION (this << distance);
m_distanceFromRoot = distance;
}
uint32_t
SPFVertex::GetDistanceFromRoot (void) const
{
NS_LOG_FUNCTION (this);
return m_distanceFromRoot;
}
void
SPFVertex::SetParent (SPFVertex* parent)
{
NS_LOG_FUNCTION (this << parent);
// always maintain only one parent when using setter/getter methods
m_parents.clear ();
m_parents.push_back (parent);
}
SPFVertex*
SPFVertex::GetParent (uint32_t i) const
{
NS_LOG_FUNCTION (this << i);
// If the index i is out-of-range, return 0 and do nothing
if (m_parents.size () <= i)
{
NS_LOG_LOGIC ("Index to SPFVertex's parent is out-of-range.");
return 0;
}
ListOfSPFVertex_t::const_iterator iter = m_parents.begin ();
while (i-- > 0)
{
iter++;
}
return *iter;
}
void
SPFVertex::MergeParent (const SPFVertex* v)
{
NS_LOG_FUNCTION (this << v);
NS_LOG_LOGIC ("Before merge, list of parents = " << m_parents);
// combine the two lists first, and then remove any duplicated after
m_parents.insert (m_parents.end (),
v->m_parents.begin (), v->m_parents.end ());
// remove duplication
m_parents.sort ();
m_parents.unique ();
NS_LOG_LOGIC ("After merge, list of parents = " << m_parents);
}
void
SPFVertex::SetRootExitDirection (Ipv4Address nextHop, int32_t id)
{
NS_LOG_FUNCTION (this << nextHop << id);
// always maintain only one root's exit
m_ecmpRootExits.clear ();
m_ecmpRootExits.push_back (NodeExit_t (nextHop, id));
// update the following in order to be backward compatitable with
// GetNextHop and GetOutgoingInterface methods
m_nextHop = nextHop;
m_rootOif = id;
}
void
SPFVertex::SetRootExitDirection (SPFVertex::NodeExit_t exit)
{
NS_LOG_FUNCTION (this << exit);
SetRootExitDirection (exit.first, exit.second);
}
SPFVertex::NodeExit_t
SPFVertex::GetRootExitDirection (uint32_t i) const
{
NS_LOG_FUNCTION (this << i);
typedef ListOfNodeExit_t::const_iterator CIter_t;
NS_ASSERT_MSG (i < m_ecmpRootExits.size (), "Index out-of-range when accessing SPFVertex::m_ecmpRootExits!");
CIter_t iter = m_ecmpRootExits.begin ();
while (i-- > 0) { iter++; }
return *iter;
}
SPFVertex::NodeExit_t
SPFVertex::GetRootExitDirection () const
{
NS_LOG_FUNCTION (this);
NS_ASSERT_MSG (m_ecmpRootExits.size () <= 1, "Assumed there is at most one exit from the root to this vertex");
return GetRootExitDirection (0);
}
void
SPFVertex::MergeRootExitDirections (const SPFVertex* vertex)
{
NS_LOG_FUNCTION (this << vertex);
// obtain the external list of exit directions
//
// Append the external list into 'this' and remove duplication afterward
const ListOfNodeExit_t& extList = vertex->m_ecmpRootExits;
m_ecmpRootExits.insert (m_ecmpRootExits.end (),
extList.begin (), extList.end ());
m_ecmpRootExits.sort ();
m_ecmpRootExits.unique ();
}
void
SPFVertex::InheritAllRootExitDirections (const SPFVertex* vertex)
{
NS_LOG_FUNCTION (this << vertex);
// discard all exit direction currently associated with this vertex,
// and copy all the exit directions from the given vertex
if (m_ecmpRootExits.size () > 0)
{
NS_LOG_WARN ("x root exit directions in this vertex are going to be discarded");
}
m_ecmpRootExits.clear ();
m_ecmpRootExits.insert (m_ecmpRootExits.end (),
vertex->m_ecmpRootExits.begin (), vertex->m_ecmpRootExits.end ());
}
uint32_t
SPFVertex::GetNRootExitDirections () const
{
NS_LOG_FUNCTION (this);
return m_ecmpRootExits.size ();
}
uint32_t
SPFVertex::GetNChildren (void) const
{
NS_LOG_FUNCTION (this);
return m_children.size ();
}
SPFVertex*
SPFVertex::GetChild (uint32_t n) const
{
NS_LOG_FUNCTION (this << n);
uint32_t j = 0;
for ( ListOfSPFVertex_t::const_iterator i = m_children.begin ();
i != m_children.end ();
i++, j++)
{
if (j == n)
{
return *i;
}
}
NS_ASSERT_MSG (false, "Index <n> out of range.");
return 0;
}
uint32_t
SPFVertex::AddChild (SPFVertex* child)
{
NS_LOG_FUNCTION (this << child);
m_children.push_back (child);
return m_children.size ();
}
void
SPFVertex::SetVertexProcessed (bool value)
{
NS_LOG_FUNCTION (this << value);
m_vertexProcessed = value;
}
bool
SPFVertex::IsVertexProcessed (void) const
{
NS_LOG_FUNCTION (this);
return m_vertexProcessed;
}
void
SPFVertex::ClearVertexProcessed (void)
{
NS_LOG_FUNCTION (this);
for (uint32_t i = 0; i < this->GetNChildren (); i++)
{
this->GetChild (i)->ClearVertexProcessed ();
}
this->SetVertexProcessed (false);
}
// ---------------------------------------------------------------------------
//
// GlobalRouteManagerLSDB Implementation
//
// ---------------------------------------------------------------------------
GlobalRouteManagerLSDB::GlobalRouteManagerLSDB ()
:
m_database (),
m_extdatabase ()
{
NS_LOG_FUNCTION (this);
}
GlobalRouteManagerLSDB::~GlobalRouteManagerLSDB ()
{
NS_LOG_FUNCTION (this);
LSDBMap_t::iterator i;
for (i= m_database.begin (); i!= m_database.end (); i++)
{
NS_LOG_LOGIC ("free LSA");
GlobalRoutingLSA* temp = i->second;
delete temp;
}
for (uint32_t j = 0; j < m_extdatabase.size (); j++)
{
NS_LOG_LOGIC ("free ASexternalLSA");
GlobalRoutingLSA* temp = m_extdatabase.at (j);
delete temp;
}
NS_LOG_LOGIC ("clear map");
m_database.clear ();
}
void
GlobalRouteManagerLSDB::Initialize ()
{
NS_LOG_FUNCTION (this);
LSDBMap_t::iterator i;
for (i= m_database.begin (); i!= m_database.end (); i++)
{
GlobalRoutingLSA* temp = i->second;
temp->SetStatus (GlobalRoutingLSA::LSA_SPF_NOT_EXPLORED);
}
}
void
GlobalRouteManagerLSDB::Insert (Ipv4Address addr, GlobalRoutingLSA* lsa)
{
NS_LOG_FUNCTION (this << addr << lsa);
if (lsa->GetLSType () == GlobalRoutingLSA::ASExternalLSAs)
{
m_extdatabase.push_back (lsa);
}
else
{
m_database.insert (LSDBPair_t (addr, lsa));
}
}
GlobalRoutingLSA*
GlobalRouteManagerLSDB::GetExtLSA (uint32_t index) const
{
NS_LOG_FUNCTION (this << index);
return m_extdatabase.at (index);
}
uint32_t
GlobalRouteManagerLSDB::GetNumExtLSAs () const
{
NS_LOG_FUNCTION (this);
return m_extdatabase.size ();
}
GlobalRoutingLSA*
GlobalRouteManagerLSDB::GetLSA (Ipv4Address addr) const
{
NS_LOG_FUNCTION (this << addr);
//
// Look up an LSA by its address.
//
LSDBMap_t::const_iterator i;
for (i= m_database.begin (); i!= m_database.end (); i++)
{
if (i->first == addr)
{
return i->second;
}
}
return 0;
}
GlobalRoutingLSA*
GlobalRouteManagerLSDB::GetLSAByLinkData (Ipv4Address addr) const
{
NS_LOG_FUNCTION (this << addr);
//
// Look up an LSA by its address.
//
LSDBMap_t::const_iterator i;
for (i= m_database.begin (); i!= m_database.end (); i++)
{
GlobalRoutingLSA* temp = i->second;
// Iterate among temp's Link Records
for (uint32_t j = 0; j < temp->GetNLinkRecords (); j++)
{
GlobalRoutingLinkRecord *lr = temp->GetLinkRecord (j);
if ( lr->GetLinkType () == GlobalRoutingLinkRecord::TransitNetwork &&
lr->GetLinkData () == addr)
{
return temp;
}
}
}
return 0;
}
// ---------------------------------------------------------------------------
//
// GlobalRouteManagerImpl Implementation
//
// ---------------------------------------------------------------------------
GlobalRouteManagerImpl::GlobalRouteManagerImpl ()
:
m_spfroot (0)
{
NS_LOG_FUNCTION (this);
m_lsdb = new GlobalRouteManagerLSDB ();
}
GlobalRouteManagerImpl::~GlobalRouteManagerImpl ()
{
NS_LOG_FUNCTION (this);
if (m_lsdb)
{
delete m_lsdb;
}
}
void
GlobalRouteManagerImpl::DebugUseLsdb (GlobalRouteManagerLSDB* lsdb)
{
NS_LOG_FUNCTION (this << lsdb);
if (m_lsdb)
{
delete m_lsdb;
}
m_lsdb = lsdb;
}
void
GlobalRouteManagerImpl::DeleteGlobalRoutes ()
{
NS_LOG_FUNCTION (this);
NodeList::Iterator listEnd = NodeList::End ();
for (NodeList::Iterator i = NodeList::Begin (); i != listEnd; i++)
{
Ptr<Node> node = *i;
Ptr<GlobalRouter> router = node->GetObject<GlobalRouter> ();
if (router == 0)
{
continue;
}
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
uint32_t j = 0;
uint32_t nRoutes = gr->GetNRoutes ();
NS_LOG_LOGIC ("Deleting " << gr->GetNRoutes ()<< " routes from node " << node->GetId ());
// Each time we delete route 0, the route index shifts downward
// We can delete all routes if we delete the route numbered 0
// nRoutes times
for (j = 0; j < nRoutes; j++)
{
NS_LOG_LOGIC ("Deleting global route " << j << " from node " << node->GetId ());
gr->RemoveRoute (0);
}
NS_LOG_LOGIC ("Deleted " << j << " global routes from node "<< node->GetId ());
}
if (m_lsdb)
{
NS_LOG_LOGIC ("Deleting LSDB, creating new one");
delete m_lsdb;
m_lsdb = new GlobalRouteManagerLSDB ();
}
}
//
// In order to build the routing database, we need to walk the list of nodes
// in the system and look for those that support the GlobalRouter interface.
// These routers will export a number of Link State Advertisements (LSAs)
// that describe the links and networks that are "adjacent" (i.e., that are
// on the other side of a point-to-point link). We take these LSAs and put
// add them to the Link State DataBase (LSDB) from which the routes will
// ultimately be computed.
//
void
GlobalRouteManagerImpl::BuildGlobalRoutingDatabase ()
{
NS_LOG_FUNCTION (this);
//
// Walk the list of nodes looking for the GlobalRouter Interface. Nodes with
// global router interfaces are, not too surprisingly, our routers.
//
NodeList::Iterator listEnd = NodeList::End ();
for (NodeList::Iterator i = NodeList::Begin (); i != listEnd; i++)
{
Ptr<Node> node = *i;
Ptr<GlobalRouter> rtr = node->GetObject<GlobalRouter> ();
//
// Ignore nodes that aren't participating in routing.
//
if (!rtr)
{
continue;
}
//
// You must call DiscoverLSAs () before trying to use any routing info or to
// update LSAs. DiscoverLSAs () drives the process of discovering routes in
// the GlobalRouter. Afterward, you may use GetNumLSAs (), which is a very
// computationally inexpensive call. If you call GetNumLSAs () before calling
// DiscoverLSAs () will get zero as the number since no routes have been
// found.
//
Ptr<Ipv4GlobalRouting> grouting = rtr->GetRoutingProtocol ();
uint32_t numLSAs = rtr->DiscoverLSAs ();
NS_LOG_LOGIC ("Found " << numLSAs << " LSAs");
for (uint32_t j = 0; j < numLSAs; ++j)
{
GlobalRoutingLSA* lsa = new GlobalRoutingLSA ();
//
// This is the call to actually fetch a Link State Advertisement from the
// router.
//
rtr->GetLSA (j, *lsa);
NS_LOG_LOGIC (*lsa);
//
// Write the newly discovered link state advertisement to the database.
//
m_lsdb->Insert (lsa->GetLinkStateId (), lsa);
}
}
}
//
// For each node that is a global router (which is determined by the presence
// of an aggregated GlobalRouter interface), run the Dijkstra SPF calculation
// on the database rooted at that router, and populate the node forwarding
// tables.
//
// This function parallels RFC2328, Section 16.1.1, and quagga ospfd
//
// This calculation yields the set of intra-area routes associated
// with an area (called hereafter Area A). A router calculates the
// shortest-path tree using itself as the root. The formation
// of the shortest path tree is done here in two stages. In the
// first stage, only links between routers and transit networks are
// considered. Using the Dijkstra algorithm, a tree is formed from
// this subset of the link state database. In the second stage,
// leaves are added to the tree by considering the links to stub
// networks.
//
// The area's link state database is represented as a directed graph.
// The graph's vertices are routers, transit networks and stub networks.
//
// The first stage of the procedure (i.e., the Dijkstra algorithm)
// can now be summarized as follows. At each iteration of the
// algorithm, there is a list of candidate vertices. Paths from
// the root to these vertices have been found, but not necessarily
// the shortest ones. However, the paths to the candidate vertex
// that is closest to the root are guaranteed to be shortest; this
// vertex is added to the shortest-path tree, removed from the
// candidate list, and its adjacent vertices are examined for
// possible addition to/modification of the candidate list. The
// algorithm then iterates again. It terminates when the candidate
// list becomes empty.
//
void
GlobalRouteManagerImpl::InitializeRoutes ()
{
NS_LOG_FUNCTION (this);
//
// Walk the list of nodes in the system.
//
NS_LOG_INFO ("About to start SPF calculation");
NodeList::Iterator listEnd = NodeList::End ();
for (NodeList::Iterator i = NodeList::Begin (); i != listEnd; i++)
{
Ptr<Node> node = *i;
//
// Look for the GlobalRouter interface that indicates that the node is
// participating in routing.
//
Ptr<GlobalRouter> rtr =
node->GetObject<GlobalRouter> ();
uint32_t systemId = MpiInterface::GetSystemId ();
// Ignore nodes that are not assigned to our systemId (distributed sim)
if (node->GetSystemId () != systemId)
{
continue;
}
//
// if the node has a global router interface, then run the global routing
// algorithms.
//
if (rtr && rtr->GetNumLSAs () )
{
SPFCalculate (rtr->GetRouterId ());
}
}
NS_LOG_INFO ("Finished SPF calculation");
}
//
// This method is derived from quagga ospf_spf_next (). See RFC2328 Section
// 16.1 (2) for further details.
//
// We're passed a parameter <v> that is a vertex which is already in the SPF
// tree. A vertex represents a router node. We also get a reference to the
// SPF candidate queue, which is a priority queue containing the shortest paths
// to the networks we know about.
//
// We examine the links in v's LSA and update the list of candidates with any
// vertices not already on the list. If a lower-cost path is found to a
// vertex already on the candidate list, store the new (lower) cost.
//
void
GlobalRouteManagerImpl::SPFNext (SPFVertex* v, CandidateQueue& candidate)
{
NS_LOG_FUNCTION (this << v << &candidate);
SPFVertex* w = 0;
GlobalRoutingLSA* w_lsa = 0;
GlobalRoutingLinkRecord *l = 0;
uint32_t distance = 0;
uint32_t numRecordsInVertex = 0;
//
// V points to a Router-LSA or Network-LSA
// Loop over the links in router LSA or attached routers in Network LSA
//
if (v->GetVertexType () == SPFVertex::VertexRouter)
{
numRecordsInVertex = v->GetLSA ()->GetNLinkRecords ();
}
if (v->GetVertexType () == SPFVertex::VertexNetwork)
{
numRecordsInVertex = v->GetLSA ()->GetNAttachedRouters ();
}
for (uint32_t i = 0; i < numRecordsInVertex; i++)
{
// Get w_lsa: In case of V is Router-LSA
if (v->GetVertexType () == SPFVertex::VertexRouter)
{
NS_LOG_LOGIC ("Examining link " << i << " of " <<
v->GetVertexId () << "'s " <<
v->GetLSA ()->GetNLinkRecords () << " link records");
//
// (a) If this is a link to a stub network, examine the next link in V's LSA.
// Links to stub networks will be considered in the second stage of the
// shortest path calculation.
//
l = v->GetLSA ()->GetLinkRecord (i);
NS_ASSERT (l != 0);
if (l->GetLinkType () == GlobalRoutingLinkRecord::StubNetwork)
{
NS_LOG_LOGIC ("Found a Stub record to " << l->GetLinkId ());
continue;
}
//
// (b) Otherwise, W is a transit vertex (router or transit network). Look up
// the vertex W's LSA (router-LSA or network-LSA) in Area A's link state
// database.
//
if (l->GetLinkType () == GlobalRoutingLinkRecord::PointToPoint)
{
//
// Lookup the link state advertisement of the new link -- we call it <w> in
// the link state database.
//
w_lsa = m_lsdb->GetLSA (l->GetLinkId ());
NS_ASSERT (w_lsa);
NS_LOG_LOGIC ("Found a P2P record from " <<
v->GetVertexId () << " to " << w_lsa->GetLinkStateId ());
}
else if (l->GetLinkType () ==
GlobalRoutingLinkRecord::TransitNetwork)
{
w_lsa = m_lsdb->GetLSA (l->GetLinkId ());
NS_ASSERT (w_lsa);
NS_LOG_LOGIC ("Found a Transit record from " <<
v->GetVertexId () << " to " << w_lsa->GetLinkStateId ());
}
else
{
NS_ASSERT_MSG (0, "illegal Link Type");
}
}
// Get w_lsa: In case of V is Network-LSA
if (v->GetVertexType () == SPFVertex::VertexNetwork)
{
w_lsa = m_lsdb->GetLSAByLinkData
(v->GetLSA ()->GetAttachedRouter (i));
if (!w_lsa)
{
continue;
}
NS_LOG_LOGIC ("Found a Network LSA from " <<
v->GetVertexId () << " to " << w_lsa->GetLinkStateId ());
}
// Note: w_lsa at this point may be either RouterLSA or NetworkLSA
//
// (c) If vertex W is already on the shortest-path tree, examine the next
// link in the LSA.
//
// If the link is to a router that is already in the shortest path first tree
// then we have it covered -- ignore it.
//
if (w_lsa->GetStatus () == GlobalRoutingLSA::LSA_SPF_IN_SPFTREE)
{
NS_LOG_LOGIC ("Skipping -> LSA "<<
w_lsa->GetLinkStateId () << " already in SPF tree");
continue;
}
//
// (d) Calculate the link state cost D of the resulting path from the root to
// vertex W. D is equal to the sum of the link state cost of the (already
// calculated) shortest path to vertex V and the advertised cost of the link
// between vertices V and W.
//
if (v->GetLSA ()->GetLSType () == GlobalRoutingLSA::RouterLSA)
{
NS_ASSERT (l != 0);
distance = v->GetDistanceFromRoot () + l->GetMetric ();
}
else
{
distance = v->GetDistanceFromRoot ();
}
NS_LOG_LOGIC ("Considering w_lsa " << w_lsa->GetLinkStateId ());
// Is there already vertex w in candidate list?
if (w_lsa->GetStatus () == GlobalRoutingLSA::LSA_SPF_NOT_EXPLORED)
{
// Calculate nexthop to w
// We need to figure out how to actually get to the new router represented
// by <w>. This will (among other things) find the next hop address to send
// packets destined for this network to, and also find the outbound interface
// used to forward the packets.
// prepare vertex w
w = new SPFVertex (w_lsa);
if (SPFNexthopCalculation (v, w, l, distance))
{
w_lsa->SetStatus (GlobalRoutingLSA::LSA_SPF_CANDIDATE);
//
// Push this new vertex onto the priority queue (ordered by distance from the
// root node).
//
candidate.Push (w);
NS_LOG_LOGIC ("Pushing " <<
w->GetVertexId () << ", parent vertexId: " <<
v->GetVertexId () << ", distance: " <<
w->GetDistanceFromRoot ());
}
else
NS_ASSERT_MSG (0, "SPFNexthopCalculation never "
<< "return false, but it does now!");
}
else if (w_lsa->GetStatus () == GlobalRoutingLSA::LSA_SPF_CANDIDATE)
{
//
// We have already considered the link represented by <w>. What wse have to
// do now is to decide if this new router represents a route with a shorter
// distance metric.
//
// So, locate the vertex in the candidate queue and take a look at the
// distance.
/* (quagga-0.98.6) W is already on the candidate list; call it cw.
* Compare the previously calculated cost (cw->distance)
* with the cost we just determined (w->distance) to see
* if we've found a shorter path.
*/
SPFVertex* cw;
cw = candidate.Find (w_lsa->GetLinkStateId ());
if (cw->GetDistanceFromRoot () < distance)
{
//
// This is not a shorter path, so don't do anything.
//
continue;
}
else if (cw->GetDistanceFromRoot () == distance)
{
//
// This path is one with an equal cost.
//
NS_LOG_LOGIC ("Equal cost multiple paths found.");
// At this point, there are two instances 'w' and 'cw' of the
// same vertex, the vertex that is currently being considered
// for adding into the shortest path tree. 'w' is the instance
// as seen from the root via vertex 'v', and 'cw' is the instance
// as seen from the root via some other vertices other than 'v'.
// These two instances are being merged in the following code.
// In particular, the parent nodes, the next hops, and the root's
// output interfaces of the two instances are being merged.
//
// Note that this is functionally equivalent to calling
// ospf_nexthop_merge (cw->nexthop, w->nexthop) in quagga-0.98.6
// (ospf_spf.c::859), although the detail implementation
// is very different from quagga (blame ns3::GlobalRouteManagerImpl)
// prepare vertex w
w = new SPFVertex (w_lsa);
SPFNexthopCalculation (v, w, l, distance);
cw->MergeRootExitDirections (w);
cw->MergeParent (w);
// SPFVertexAddParent (w) is necessary as the destructor of
// SPFVertex checks if the vertex and its parent is linked
// bidirectionally
SPFVertexAddParent (w);
delete w;
}
else // cw->GetDistanceFromRoot () > w->GetDistanceFromRoot ()
{
//
// this path represents a new, lower-cost path to <w> (the vertex we found in
// the current link record of the link state advertisement of the current root
// (vertex <v>)
//
// N.B. the nexthop_calculation is conditional, if it finds a valid nexthop
// it will call spf_add_parents, which will flush the old parents
//
if (SPFNexthopCalculation (v, cw, l, distance))
{
//
// If we've changed the cost to get to the vertex represented by <w>, we
// must reorder the priority queue keyed to that cost.
//
candidate.Reorder ();
}
} // new lower cost path found
} // end W is already on the candidate list
} // end loop over the links in V's LSA
}
//
// This method is derived from quagga ospf_nexthop_calculation() 16.1.1.
//
// Calculate nexthop from root through V (parent) to vertex W (destination)
// with given distance from root->W.
//
// As appropriate, set w's parent, distance, and nexthop information
//
// For now, this is greatly simplified from the quagga code
//
int
GlobalRouteManagerImpl::SPFNexthopCalculation (
SPFVertex* v,
SPFVertex* w,
GlobalRoutingLinkRecord* l,
uint32_t distance)
{
NS_LOG_FUNCTION (this << v << w << l << distance);
//
// If w is a NetworkVertex, l should be null
/*
if (w->GetVertexType () == SPFVertex::VertexNetwork && l)
{
NS_ASSERT_MSG (0, "Error: SPFNexthopCalculation parameter problem");
}
*/
//
// The vertex m_spfroot is a distinguished vertex representing the node at
// the root of the calculations. That is, it is the node for which we are
// calculating the routes.
//
// There are two distinct cases for calculating the next hop information.
// First, if we're considering a hop from the root to an "adjacent" network
// (one that is on the other side of a point-to-point link connected to the
// root), then we need to store the information needed to forward down that
// link. The second case is if the network is not directly adjacent. In that
// case we need to use the forwarding information from the vertex on the path
// to the destination that is directly adjacent [node 1] in both cases of the
// diagram below.
//
// (1) [root] -> [point-to-point] -> [node 1]
// (2) [root] -> [point-to-point] -> [node 1] -> [point-to-point] -> [node 2]
//
// We call the propagation of next hop information down vertices of a path
// "inheriting" the next hop information.
//
// The point-to-point link information is only useful in this calculation when
// we are examining the root node.
//
if (v == m_spfroot)
{
//
// In this case <v> is the root node, which means it is the starting point
// for the packets forwarded by that node. This also means that the next hop
// address of packets headed for some arbitrary off-network destination must
// be the destination at the other end of one of the links off of the root
// node if this root node is a router. We then need to see if this node <w>
// is a router.
//
if (w->GetVertexType () == SPFVertex::VertexRouter)
{
//
// In the case of point-to-point links, the link data field (m_linkData) of a
// Global Router Link Record contains the local IP address. If we look at the
// link record describing the link from the perspecive of <w> (the remote
// node from the viewpoint of <v>) back to the root node, we can discover the
// IP address of the router to which <v> is adjacent. This is a distinguished
// address -- the next hop address to get from <v> to <w> and all networks
// accessed through that path.
//
// SPFGetNextLink () is a little odd. used in this way it is just going to
// return the link record describing the link from <w> to <v>. Think of it as
// SPFGetLink.
//
NS_ASSERT (l);
GlobalRoutingLinkRecord *linkRemote = 0;
linkRemote = SPFGetNextLink (w, v, linkRemote);
//
// At this point, <l> is the Global Router Link Record describing the point-
// to point link from <v> to <w> from the perspective of <v>; and <linkRemote>
// is the Global Router Link Record describing that same link from the
// perspective of <w> (back to <v>). Now we can just copy the next hop
// address from the m_linkData member variable.
//
// The next hop member variable we put in <w> has the sense "in order to get
// from the root node to the host represented by vertex <w>, you have to send
// the packet to the next hop address specified in w->m_nextHop.
//
Ipv4Address nextHop = linkRemote->GetLinkData ();
//
// Now find the outgoing interface corresponding to the point to point link
// from the perspective of <v> -- remember that <l> is the link "from"
// <v> "to" <w>.
//
uint32_t outIf = FindOutgoingInterfaceId (l->GetLinkData ());
w->SetRootExitDirection (nextHop, outIf);
w->SetDistanceFromRoot (distance);
w->SetParent (v);
NS_LOG_LOGIC ("Next hop from " <<
v->GetVertexId () << " to " << w->GetVertexId () <<
" goes through next hop " << nextHop <<
" via outgoing interface " << outIf <<
" with distance " << distance);
} // end W is a router vertes
else
{
NS_ASSERT (w->GetVertexType () == SPFVertex::VertexNetwork);
// W is a directly connected network; no next hop is required
GlobalRoutingLSA* w_lsa = w->GetLSA ();
NS_ASSERT (w_lsa->GetLSType () == GlobalRoutingLSA::NetworkLSA);
// Find outgoing interface ID for this network
uint32_t outIf = FindOutgoingInterfaceId (w_lsa->GetLinkStateId (),
w_lsa->GetNetworkLSANetworkMask () );
// Set the next hop to 0.0.0.0 meaning "not exist"
Ipv4Address nextHop = Ipv4Address::GetZero ();
w->SetRootExitDirection (nextHop, outIf);
w->SetDistanceFromRoot (distance);
w->SetParent (v);
NS_LOG_LOGIC ("Next hop from " <<
v->GetVertexId () << " to network " << w->GetVertexId () <<
" via outgoing interface " << outIf <<
" with distance " << distance);
return 1;
}
} // end v is the root
else if (v->GetVertexType () == SPFVertex::VertexNetwork)
{
// See if any of v's parents are the root
if (v->GetParent () == m_spfroot)
{
// 16.1.1 para 5. ...the parent vertex is a network that
// directly connects the calculating router to the destination
// router. The list of next hops is then determined by
// examining the destination's router-LSA...
NS_ASSERT (w->GetVertexType () == SPFVertex::VertexRouter);
GlobalRoutingLinkRecord *linkRemote = 0;
while ((linkRemote = SPFGetNextLink (w, v, linkRemote)))
{
/* ...For each link in the router-LSA that points back to the
* parent network, the link's Link Data field provides the IP
* address of a next hop router. The outgoing interface to
* use can then be derived from the next hop IP address (or
* it can be inherited from the parent network).
*/
Ipv4Address nextHop = linkRemote->GetLinkData ();
uint32_t outIf = v->GetRootExitDirection ().second;
w->SetRootExitDirection (nextHop, outIf);
NS_LOG_LOGIC ("Next hop from " <<
v->GetVertexId () << " to " << w->GetVertexId () <<
" goes through next hop " << nextHop <<
" via outgoing interface " << outIf);
}
}
else
{
w->SetRootExitDirection (v->GetRootExitDirection ());
}
}
else
{
//
// If we're calculating the next hop information from a node (v) that is
// *not* the root, then we need to "inherit" the information needed to
// forward the packet from the vertex closer to the root. That is, we'll
// still send packets to the next hop address of the router adjacent to the
// root on the path toward <w>.
//
// Above, when we were considering the root node, we calculated the next hop
// address and outgoing interface required to get off of the root network.
// At this point, we are further away from the root network along one of the
// (shortest) paths. So the next hop and outoing interface remain the same
// (are inherited).
//
w->InheritAllRootExitDirections (v);
}
//
// In all cases, we need valid values for the distance metric and a parent.
//
w->SetDistanceFromRoot (distance);
w->SetParent (v);
return 1;
}
//
// This method is derived from quagga ospf_get_next_link ()
//
// First search the Global Router Link Records of vertex <v> for one
// representing a point-to point link to vertex <w>.
//
// What is done depends on prev_link. Contrary to appearances, prev_link just
// acts as a flag here. If prev_link is NULL, we return the first Global
// Router Link Record we find that describes a point-to-point link from <v>
// to <w>. If prev_link is not NULL, we return a Global Router Link Record
// representing a possible *second* link from <v> to <w>.
//
GlobalRoutingLinkRecord*
GlobalRouteManagerImpl::SPFGetNextLink (
SPFVertex* v,
SPFVertex* w,
GlobalRoutingLinkRecord* prev_link)
{
NS_LOG_FUNCTION (this << v << w << prev_link);
bool skip = true;
bool found_prev_link = false;
GlobalRoutingLinkRecord* l;
//
// If prev_link is 0, we are really looking for the first link, not the next
// link.
//
if (prev_link == 0)
{
skip = false;
found_prev_link = true;
}
//
// Iterate through the Global Router Link Records advertised by the vertex
// <v> looking for records representing the point-to-point links off of this
// vertex.
//
for (uint32_t i = 0; i < v->GetLSA ()->GetNLinkRecords (); ++i)
{
l = v->GetLSA ()->GetLinkRecord (i);
//
// The link ID of a link record representing a point-to-point link is set to
// the router ID of the neighboring router -- the router to which the link
// connects from the perspective of <v> in this case. The vertex ID is also
// set to the router ID (using the link state advertisement of a router node).
// We're just checking to see if the link <l> is actually the link from <v> to
// <w>.
//
if (l->GetLinkId () == w->GetVertexId ())
{
if (!found_prev_link)
{
NS_LOG_LOGIC ("Skipping links before prev_link found");
found_prev_link = true;
continue;
}
NS_LOG_LOGIC ("Found matching link l: linkId = " <<
l->GetLinkId () << " linkData = " << l->GetLinkData ());
//
// If skip is false, don't (not too surprisingly) skip the link found -- it's
// the one we're interested in. That's either because we didn't pass in a
// previous link, and we're interested in the first one, or because we've
// skipped a previous link and moved forward to the next (which is then the
// one we want).
//
if (skip == false)
{
NS_LOG_LOGIC ("Returning the found link");
return l;
}
else
{
//
// Skip is true and we've found a link from <v> to <w>. We want the next one.
// Setting skip to false gets us the next point-to-point global router link
// record in the LSA from <v>.
//
NS_LOG_LOGIC ("Skipping the found link");
skip = false;
continue;
}
}
}
return 0;
}
//
// Used for unit tests.
//
void
GlobalRouteManagerImpl::DebugSPFCalculate (Ipv4Address root)
{
NS_LOG_FUNCTION (this << root);
SPFCalculate (root);
}
//
// Used to test if a node is a stub, from an OSPF sense.
// If there is only one link of type 1 or 2, then a default route
// can safely be added to the next-hop router and SPF does not need
// to be run
//
bool
GlobalRouteManagerImpl::CheckForStubNode (Ipv4Address root)
{
NS_LOG_FUNCTION (this << root);
GlobalRoutingLSA *rlsa = m_lsdb->GetLSA (root);
Ipv4Address myRouterId = rlsa->GetLinkStateId ();
int transits = 0;
GlobalRoutingLinkRecord *transitLink = 0;
for (uint32_t i = 0; i < rlsa->GetNLinkRecords (); i++)
{
GlobalRoutingLinkRecord *l = rlsa->GetLinkRecord (i);
if (l->GetLinkType () == GlobalRoutingLinkRecord::TransitNetwork)
{
transits++;
transitLink = l;
}
else if (l->GetLinkType () == GlobalRoutingLinkRecord::PointToPoint)
{
transits++;
transitLink = l;
}
}
if (transits == 0)
{
// This router is not connected to any router. Probably, global
// routing should not be called for this node, but we can just raise
// a warning here and return true.
NS_LOG_WARN ("all nodes should have at least one transit link:" << root );
return true;
}
if (transits == 1)
{
if (transitLink->GetLinkType () == GlobalRoutingLinkRecord::TransitNetwork)
{
// Install default route to next hop router
// What is the next hop? We need to check all neighbors on the link.
// If there is a single router that has two transit links, then
// that is the default next hop. If there are more than one
// routers on link with multiple transit links, return false.
// Not yet implemented, so simply return false
NS_LOG_LOGIC ("TBD: Would have inserted default for transit");
return false;
}
else if (transitLink->GetLinkType () == GlobalRoutingLinkRecord::PointToPoint)
{
// Install default route to next hop
// The link record LinkID is the router ID of the peer.
// The Link Data is the local IP interface address
GlobalRoutingLSA *w_lsa = m_lsdb->GetLSA (transitLink->GetLinkId ());
uint32_t nLinkRecords = w_lsa->GetNLinkRecords ();
for (uint32_t j = 0; j < nLinkRecords; ++j)
{
//
// We are only concerned about point-to-point links
//
GlobalRoutingLinkRecord *lr = w_lsa->GetLinkRecord (j);
if (lr->GetLinkType () != GlobalRoutingLinkRecord::PointToPoint)
{
continue;
}
// Find the link record that corresponds to our routerId
if (lr->GetLinkId () == myRouterId)
{
// Next hop is stored in the LinkID field of lr
Ptr<GlobalRouter> router = rlsa->GetNode ()->GetObject<GlobalRouter> ();
NS_ASSERT (router);
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
NS_ASSERT (gr);
gr->AddNetworkRouteTo (Ipv4Address ("0.0.0.0"), Ipv4Mask ("0.0.0.0"), lr->GetLinkData (),
FindOutgoingInterfaceId (transitLink->GetLinkData ()));
NS_LOG_LOGIC ("Inserting default route for node " << myRouterId << " to next hop " <<
lr->GetLinkData () << " via interface " <<
FindOutgoingInterfaceId (transitLink->GetLinkData ()));
return true;
}
}
}
}
return false;
}
// quagga ospf_spf_calculate
void
GlobalRouteManagerImpl::SPFCalculate (Ipv4Address root)
{
NS_LOG_FUNCTION (this << root);
SPFVertex *v;
//
// Initialize the Link State Database.
//
m_lsdb->Initialize ();
//
// The candidate queue is a priority queue of SPFVertex objects, with the top
// of the queue being the closest vertex in terms of distance from the root
// of the tree. Initially, this queue is empty.
//
CandidateQueue candidate;
NS_ASSERT (candidate.Size () == 0);
//
// Initialize the shortest-path tree to only contain the router doing the
// calculation. Each router (and corresponding network) is a vertex in the
// shortest path first (SPF) tree.
//
v = new SPFVertex (m_lsdb->GetLSA (root));
//
// This vertex is the root of the SPF tree and it is distance 0 from the root.
// We also mark this vertex as being in the SPF tree.
//
m_spfroot= v;
v->SetDistanceFromRoot (0);
v->GetLSA ()->SetStatus (GlobalRoutingLSA::LSA_SPF_IN_SPFTREE);
NS_LOG_LOGIC ("Starting SPFCalculate for node " << root);
//
// Optimize SPF calculation, for ns-3.
// We do not need to calculate SPF for every node in the network if this
// node has only one interface through which another router can be
// reached. Instead, short-circuit this computation and just install
// a default route in the CheckForStubNode() method.
//
if (NodeList::GetNNodes () > 0 && CheckForStubNode (root))
{
NS_LOG_LOGIC ("SPFCalculate truncated for stub node " << root);
delete m_spfroot;
return;
}
for (;;)
{
//
// The operations we need to do are given in the OSPF RFC which we reference
// as we go along.
//
// RFC2328 16.1. (2).
//
// We examine the Global Router Link Records in the Link State
// Advertisements of the current vertex. If there are any point-to-point
// links to unexplored adjacent vertices we add them to the tree and update
// the distance and next hop information on how to get there. We also add
// the new vertices to the candidate queue (the priority queue ordered by
// shortest path). If the new vertices represent shorter paths, we use them
// and update the path cost.
//
SPFNext (v, candidate);
//
// RFC2328 16.1. (3).
//
// If at this step the candidate list is empty, the shortest-path tree (of
// transit vertices) has been completely built and this stage of the
// procedure terminates.
//
if (candidate.Size () == 0)
{
break;
}
//
// Choose the vertex belonging to the candidate list that is closest to the
// root, and add it to the shortest-path tree (removing it from the candidate
// list in the process).
//
// Recall that in the previous step, we created SPFVertex structures for each
// of the routers found in the Global Router Link Records and added tehm to
// the candidate list.
//
NS_LOG_LOGIC (candidate);
v = candidate.Pop ();
NS_LOG_LOGIC ("Popped vertex " << v->GetVertexId ());
//
// Update the status field of the vertex to indicate that it is in the SPF
// tree.
//
v->GetLSA ()->SetStatus (GlobalRoutingLSA::LSA_SPF_IN_SPFTREE);
//
// The current vertex has a parent pointer. By calling this rather oddly
// named method (blame quagga) we add the current vertex to the list of
// children of that parent vertex. In the next hop calculation called during
// SPFNext, the parent pointer was set but the vertex has been orphaned up
// to now.
//
SPFVertexAddParent (v);
//
// Note that when there is a choice of vertices closest to the root, network
// vertices must be chosen before router vertices in order to necessarily
// find all equal-cost paths.
//
// RFC2328 16.1. (4).
//
// This is the method that actually adds the routes. It'll walk the list
// of nodes in the system, looking for the node corresponding to the router
// ID of the root of the tree -- that is the router we're building the routes
// for. It looks for the Ipv4 interface of that node and remembers it. So
// we are only actually adding routes to that one node at the root of the SPF
// tree.
//
// We're going to pop of a pointer to every vertex in the tree except the
// root in order of distance from the root. For each of the vertices, we call
// SPFIntraAddRouter (). Down in SPFIntraAddRouter, we look at all of the
// point-to-point Global Router Link Records (the links to nodes adjacent to
// the node represented by the vertex). We add a route to the IP address
// specified by the m_linkData field of each of those link records. This will
// be the *local* IP address associated with the interface attached to the
// link. We use the outbound interface and next hop information present in
// the vertex <v> which have possibly been inherited from the root.
//
// To summarize, we're going to look at the node represented by <v> and loop
// through its point-to-point links, adding a *host* route to the local IP
// address (at the <v> side) for each of those links.
//
if (v->GetVertexType () == SPFVertex::VertexRouter)
{
SPFIntraAddRouter (v);
}
else if (v->GetVertexType () == SPFVertex::VertexNetwork)
{
SPFIntraAddTransit (v);
}
else
{
NS_ASSERT_MSG (0, "illegal SPFVertex type");
}
//
// RFC2328 16.1. (5).
//
// Iterate the algorithm by returning to Step 2 until there are no more
// candidate vertices.
} // end for loop
// Second stage of SPF calculation procedure
SPFProcessStubs (m_spfroot);
for (uint32_t i = 0; i < m_lsdb->GetNumExtLSAs (); i++)
{
m_spfroot->ClearVertexProcessed ();
GlobalRoutingLSA *extlsa = m_lsdb->GetExtLSA (i);
NS_LOG_LOGIC ("Processing External LSA with id " << extlsa->GetLinkStateId ());
ProcessASExternals (m_spfroot, extlsa);
}
//
// We're all done setting the routing information for the node at the root of
// the SPF tree. Delete all of the vertices and corresponding resources. Go
// possibly do it again for the next router.
//
delete m_spfroot;
m_spfroot = 0;
}
void
GlobalRouteManagerImpl::ProcessASExternals (SPFVertex* v, GlobalRoutingLSA* extlsa)
{
NS_LOG_FUNCTION (this << v << extlsa);
NS_LOG_LOGIC ("Processing external for destination " <<
extlsa->GetLinkStateId () <<
", for router " << v->GetVertexId () <<
", advertised by " << extlsa->GetAdvertisingRouter ());
if (v->GetVertexType () == SPFVertex::VertexRouter)
{
GlobalRoutingLSA *rlsa = v->GetLSA ();
NS_LOG_LOGIC ("Processing router LSA with id " << rlsa->GetLinkStateId ());
if ((rlsa->GetLinkStateId ()) == (extlsa->GetAdvertisingRouter ()))
{
NS_LOG_LOGIC ("Found advertising router to destination");
SPFAddASExternal (extlsa,v);
}
}
for (uint32_t i = 0; i < v->GetNChildren (); i++)
{
if (!v->GetChild (i)->IsVertexProcessed ())
{
NS_LOG_LOGIC ("Vertex's child " << i << " not yet processed, processing...");
ProcessASExternals (v->GetChild (i), extlsa);
v->GetChild (i)->SetVertexProcessed (true);
}
}
}
//
// Adding external routes to routing table - modeled after
// SPFAddIntraAddStub()
//
void
GlobalRouteManagerImpl::SPFAddASExternal (GlobalRoutingLSA *extlsa, SPFVertex *v)
{
NS_LOG_FUNCTION (this << extlsa << v);
NS_ASSERT_MSG (m_spfroot, "GlobalRouteManagerImpl::SPFAddASExternal (): Root pointer not set");
// Two cases to consider: We are advertising the external ourselves
// => No need to add anything
// OR find best path to the advertising router
if (v->GetVertexId () == m_spfroot->GetVertexId ())
{
NS_LOG_LOGIC ("External is on local host: "
<< v->GetVertexId () << "; returning");
return;
}
NS_LOG_LOGIC ("External is on remote host: "
<< extlsa->GetAdvertisingRouter () << "; installing");
Ipv4Address routerId = m_spfroot->GetVertexId ();
NS_LOG_LOGIC ("Vertex ID = " << routerId);
//
// We need to walk the list of nodes looking for the one that has the router
// ID corresponding to the root vertex. This is the one we're going to write
// the routing information to.
//
NodeList::Iterator i = NodeList::Begin ();
NodeList::Iterator listEnd = NodeList::End ();
for (; i != listEnd; i++)
{
Ptr<Node> node = *i;
//
// The router ID is accessible through the GlobalRouter interface, so we need
// to QI for that interface. If there's no GlobalRouter interface, the node
// in question cannot be the router we want, so we continue.
//
Ptr<GlobalRouter> rtr = node->GetObject<GlobalRouter> ();
if (rtr == 0)
{
NS_LOG_LOGIC ("No GlobalRouter interface on node " << node->GetId ());
continue;
}
//
// If the router ID of the current node is equal to the router ID of the
// root of the SPF tree, then this node is the one for which we need to
// write the routing tables.
//
NS_LOG_LOGIC ("Considering router " << rtr->GetRouterId ());
if (rtr->GetRouterId () == routerId)
{
NS_LOG_LOGIC ("Setting routes for node " << node->GetId ());
//
// Routing information is updated using the Ipv4 interface. We need to QI
// for that interface. If the node is acting as an IP version 4 router, it
// should absolutely have an Ipv4 interface.
//
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4,
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"QI for <Ipv4> interface failed");
//
// Get the Global Router Link State Advertisement from the vertex we're
// adding the routes to. The LSA will have a number of attached Global Router
// Link Records corresponding to links off of that vertex / node. We're going
// to be interested in the records corresponding to point-to-point links.
//
NS_ASSERT_MSG (v->GetLSA (),
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"Expected valid LSA in SPFVertex* v");
Ipv4Mask tempmask = extlsa->GetNetworkLSANetworkMask ();
Ipv4Address tempip = extlsa->GetLinkStateId ();
tempip = tempip.CombineMask (tempmask);
//
// Here's why we did all of that work. We're going to add a host route to the
// host address found in the m_linkData field of the point-to-point link
// record. In the case of a point-to-point link, this is the local IP address
// of the node connected to the link. Each of these point-to-point links
// will correspond to a local interface that has an IP address to which
// the node at the root of the SPF tree can send packets. The vertex <v>
// (corresponding to the node that has these links and interfaces) has
// an m_nextHop address precalculated for us that is the address to which the
// root node should send packets to be forwarded to these IP addresses.
// Similarly, the vertex <v> has an m_rootOif (outbound interface index) to
// which the packets should be send for forwarding.
//
Ptr<GlobalRouter> router = node->GetObject<GlobalRouter> ();
if (router == 0)
{
continue;
}
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
NS_ASSERT (gr);
// walk through all next-hop-IPs and out-going-interfaces for reaching
// the stub network gateway 'v' from the root node
for (uint32_t i = 0; i < v->GetNRootExitDirections (); i++)
{
SPFVertex::NodeExit_t exit = v->GetRootExitDirection (i);
Ipv4Address nextHop = exit.first;
int32_t outIf = exit.second;
if (outIf >= 0)
{
gr->AddASExternalRouteTo (tempip, tempmask, nextHop, outIf);
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" add external network route to " << tempip <<
" using next hop " << nextHop <<
" via interface " << outIf);
}
else
{
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" NOT able to add network route to " << tempip <<
" using next hop " << nextHop <<
" since outgoing interface id is negative");
}
}
return;
} // if
} // for
}
// Processing logic from RFC 2328, page 166 and quagga ospf_spf_process_stubs ()
// stub link records will exist for point-to-point interfaces and for
// broadcast interfaces for which no neighboring router can be found
void
GlobalRouteManagerImpl::SPFProcessStubs (SPFVertex* v)
{
NS_LOG_FUNCTION (this << v);
NS_LOG_LOGIC ("Processing stubs for " << v->GetVertexId ());
if (v->GetVertexType () == SPFVertex::VertexRouter)
{
GlobalRoutingLSA *rlsa = v->GetLSA ();
NS_LOG_LOGIC ("Processing router LSA with id " << rlsa->GetLinkStateId ());
for (uint32_t i = 0; i < rlsa->GetNLinkRecords (); i++)
{
NS_LOG_LOGIC ("Examining link " << i << " of " <<
v->GetVertexId () << "'s " <<
v->GetLSA ()->GetNLinkRecords () << " link records");
GlobalRoutingLinkRecord *l = v->GetLSA ()->GetLinkRecord (i);
if (l->GetLinkType () == GlobalRoutingLinkRecord::StubNetwork)
{
NS_LOG_LOGIC ("Found a Stub record to " << l->GetLinkId ());
SPFIntraAddStub (l, v);
continue;
}
}
}
for (uint32_t i = 0; i < v->GetNChildren (); i++)
{
if (!v->GetChild (i)->IsVertexProcessed ())
{
SPFProcessStubs (v->GetChild (i));
v->GetChild (i)->SetVertexProcessed (true);
}
}
}
// RFC2328 16.1. second stage.
void
GlobalRouteManagerImpl::SPFIntraAddStub (GlobalRoutingLinkRecord *l, SPFVertex* v)
{
NS_LOG_FUNCTION (this << l << v);
NS_ASSERT_MSG (m_spfroot,
"GlobalRouteManagerImpl::SPFIntraAddStub (): Root pointer not set");
// XXX simplifed logic for the moment. There are two cases to consider:
// 1) the stub network is on this router; do nothing for now
// (already handled above)
// 2) the stub network is on a remote router, so I should use the
// same next hop that I use to get to vertex v
if (v->GetVertexId () == m_spfroot->GetVertexId ())
{
NS_LOG_LOGIC ("Stub is on local host: " << v->GetVertexId () << "; returning");
return;
}
NS_LOG_LOGIC ("Stub is on remote host: " << v->GetVertexId () << "; installing");
//
// The root of the Shortest Path First tree is the router to which we are
// going to write the actual routing table entries. The vertex corresponding
// to this router has a vertex ID which is the router ID of that node. We're
// going to use this ID to discover which node it is that we're actually going
// to update.
//
Ipv4Address routerId = m_spfroot->GetVertexId ();
NS_LOG_LOGIC ("Vertex ID = " << routerId);
//
// We need to walk the list of nodes looking for the one that has the router
// ID corresponding to the root vertex. This is the one we're going to write
// the routing information to.
//
NodeList::Iterator i = NodeList::Begin ();
NodeList::Iterator listEnd = NodeList::End ();
for (; i != listEnd; i++)
{
Ptr<Node> node = *i;
//
// The router ID is accessible through the GlobalRouter interface, so we need
// to QI for that interface. If there's no GlobalRouter interface, the node
// in question cannot be the router we want, so we continue.
//
Ptr<GlobalRouter> rtr =
node->GetObject<GlobalRouter> ();
if (rtr == 0)
{
NS_LOG_LOGIC ("No GlobalRouter interface on node " <<
node->GetId ());
continue;
}
//
// If the router ID of the current node is equal to the router ID of the
// root of the SPF tree, then this node is the one for which we need to
// write the routing tables.
//
NS_LOG_LOGIC ("Considering router " << rtr->GetRouterId ());
if (rtr->GetRouterId () == routerId)
{
NS_LOG_LOGIC ("Setting routes for node " << node->GetId ());
//
// Routing information is updated using the Ipv4 interface. We need to QI
// for that interface. If the node is acting as an IP version 4 router, it
// should absolutely have an Ipv4 interface.
//
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4,
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"QI for <Ipv4> interface failed");
//
// Get the Global Router Link State Advertisement from the vertex we're
// adding the routes to. The LSA will have a number of attached Global Router
// Link Records corresponding to links off of that vertex / node. We're going
// to be interested in the records corresponding to point-to-point links.
//
NS_ASSERT_MSG (v->GetLSA (),
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"Expected valid LSA in SPFVertex* v");
Ipv4Mask tempmask (l->GetLinkData ().Get ());
Ipv4Address tempip = l->GetLinkId ();
tempip = tempip.CombineMask (tempmask);
//
// Here's why we did all of that work. We're going to add a host route to the
// host address found in the m_linkData field of the point-to-point link
// record. In the case of a point-to-point link, this is the local IP address
// of the node connected to the link. Each of these point-to-point links
// will correspond to a local interface that has an IP address to which
// the node at the root of the SPF tree can send packets. The vertex <v>
// (corresponding to the node that has these links and interfaces) has
// an m_nextHop address precalculated for us that is the address to which the
// root node should send packets to be forwarded to these IP addresses.
// Similarly, the vertex <v> has an m_rootOif (outbound interface index) to
// which the packets should be send for forwarding.
//
Ptr<GlobalRouter> router = node->GetObject<GlobalRouter> ();
if (router == 0)
{
continue;
}
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
NS_ASSERT (gr);
// walk through all next-hop-IPs and out-going-interfaces for reaching
// the stub network gateway 'v' from the root node
for (uint32_t i = 0; i < v->GetNRootExitDirections (); i++)
{
SPFVertex::NodeExit_t exit = v->GetRootExitDirection (i);
Ipv4Address nextHop = exit.first;
int32_t outIf = exit.second;
if (outIf >= 0)
{
gr->AddNetworkRouteTo (tempip, tempmask, nextHop, outIf);
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" add network route to " << tempip <<
" using next hop " << nextHop <<
" via interface " << outIf);
}
else
{
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" NOT able to add network route to " << tempip <<
" using next hop " << nextHop <<
" since outgoing interface id is negative");
}
}
return;
} // if
} // for
}
//
// Return the interface number corresponding to a given IP address and mask
// This is a wrapper around GetInterfaceForPrefix(), but we first
// have to find the right node pointer to pass to that function.
// If no such interface is found, return -1 (note: unit test framework
// for routing assumes -1 to be a legal return value)
//
int32_t
GlobalRouteManagerImpl::FindOutgoingInterfaceId (Ipv4Address a, Ipv4Mask amask)
{
NS_LOG_FUNCTION (this << a << amask);
//
// We have an IP address <a> and a vertex ID of the root of the SPF tree.
// The question is what interface index does this address correspond to.
// The answer is a little complicated since we have to find a pointer to
// the node corresponding to the vertex ID, find the Ipv4 interface on that
// node in order to iterate the interfaces and find the one corresponding to
// the address in question.
//
Ipv4Address routerId = m_spfroot->GetVertexId ();
//
// Walk the list of nodes in the system looking for the one corresponding to
// the node at the root of the SPF tree. This is the node for which we are
// building the routing table.
//
NodeList::Iterator i = NodeList::Begin ();
NodeList::Iterator listEnd = NodeList::End ();
for (; i != listEnd; i++)
{
Ptr<Node> node = *i;
Ptr<GlobalRouter> rtr =
node->GetObject<GlobalRouter> ();
//
// If the node doesn't have a GlobalRouter interface it can't be the one
// we're interested in.
//
if (rtr == 0)
{
continue;
}
if (rtr->GetRouterId () == routerId)
{
//
// This is the node we're building the routing table for. We're going to need
// the Ipv4 interface to look for the ipv4 interface index. Since this node
// is participating in routing IP version 4 packets, it certainly must have
// an Ipv4 interface.
//
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4,
"GlobalRouteManagerImpl::FindOutgoingInterfaceId (): "
"GetObject for <Ipv4> interface failed");
//
// Look through the interfaces on this node for one that has the IP address
// we're looking for. If we find one, return the corresponding interface
// index, or -1 if not found.
//
int32_t interface = ipv4->GetInterfaceForPrefix (a, amask);
#if 0
if (interface < 0)
{
NS_FATAL_ERROR ("GlobalRouteManagerImpl::FindOutgoingInterfaceId(): "
"Expected an interface associated with address a:" << a);
}
#endif
return interface;
}
}
//
// Couldn't find it.
//
NS_LOG_LOGIC ("FindOutgoingInterfaceId():Can't find root node " << routerId);
return -1;
}
//
// This method is derived from quagga ospf_intra_add_router ()
//
// This is where we are actually going to add the host routes to the routing
// tables of the individual nodes.
//
// The vertex passed as a parameter has just been added to the SPF tree.
// This vertex must have a valid m_root_oid, corresponding to the outgoing
// interface on the root router of the tree that is the first hop on the path
// to the vertex. The vertex must also have a next hop address, corresponding
// to the next hop on the path to the vertex. The vertex has an m_lsa field
// that has some number of link records. For each point to point link record,
// the m_linkData is the local IP address of the link. This corresponds to
// a destination IP address, reachable from the root, to which we add a host
// route.
//
void
GlobalRouteManagerImpl::SPFIntraAddRouter (SPFVertex* v)
{
NS_LOG_FUNCTION (this << v);
NS_ASSERT_MSG (m_spfroot,
"GlobalRouteManagerImpl::SPFIntraAddRouter (): Root pointer not set");
//
// The root of the Shortest Path First tree is the router to which we are
// going to write the actual routing table entries. The vertex corresponding
// to this router has a vertex ID which is the router ID of that node. We're
// going to use this ID to discover which node it is that we're actually going
// to update.
//
Ipv4Address routerId = m_spfroot->GetVertexId ();
NS_LOG_LOGIC ("Vertex ID = " << routerId);
//
// We need to walk the list of nodes looking for the one that has the router
// ID corresponding to the root vertex. This is the one we're going to write
// the routing information to.
//
NodeList::Iterator i = NodeList::Begin ();
NodeList::Iterator listEnd = NodeList::End ();
for (; i != listEnd; i++)
{
Ptr<Node> node = *i;
//
// The router ID is accessible through the GlobalRouter interface, so we need
// to GetObject for that interface. If there's no GlobalRouter interface,
// the node in question cannot be the router we want, so we continue.
//
Ptr<GlobalRouter> rtr =
node->GetObject<GlobalRouter> ();
if (rtr == 0)
{
NS_LOG_LOGIC ("No GlobalRouter interface on node " <<
node->GetId ());
continue;
}
//
// If the router ID of the current node is equal to the router ID of the
// root of the SPF tree, then this node is the one for which we need to
// write the routing tables.
//
NS_LOG_LOGIC ("Considering router " << rtr->GetRouterId ());
if (rtr->GetRouterId () == routerId)
{
NS_LOG_LOGIC ("Setting routes for node " << node->GetId ());
//
// Routing information is updated using the Ipv4 interface. We need to
// GetObject for that interface. If the node is acting as an IP version 4
// router, it should absolutely have an Ipv4 interface.
//
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4,
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"GetObject for <Ipv4> interface failed");
//
// Get the Global Router Link State Advertisement from the vertex we're
// adding the routes to. The LSA will have a number of attached Global Router
// Link Records corresponding to links off of that vertex / node. We're going
// to be interested in the records corresponding to point-to-point links.
//
GlobalRoutingLSA *lsa = v->GetLSA ();
NS_ASSERT_MSG (lsa,
"GlobalRouteManagerImpl::SPFIntraAddRouter (): "
"Expected valid LSA in SPFVertex* v");
uint32_t nLinkRecords = lsa->GetNLinkRecords ();
//
// Iterate through the link records on the vertex to which we're going to add
// routes. To make sure we're being clear, we're going to add routing table
// entries to the tables on the node corresping to the root of the SPF tree.
// These entries will have routes to the IP addresses we find from looking at
// the local side of the point-to-point links found on the node described by
// the vertex <v>.
//
NS_LOG_LOGIC (" Node " << node->GetId () <<
" found " << nLinkRecords << " link records in LSA " << lsa << "with LinkStateId "<< lsa->GetLinkStateId ());
for (uint32_t j = 0; j < nLinkRecords; ++j)
{
//
// We are only concerned about point-to-point links
//
GlobalRoutingLinkRecord *lr = lsa->GetLinkRecord (j);
if (lr->GetLinkType () != GlobalRoutingLinkRecord::PointToPoint)
{
continue;
}
//
// Here's why we did all of that work. We're going to add a host route to the
// host address found in the m_linkData field of the point-to-point link
// record. In the case of a point-to-point link, this is the local IP address
// of the node connected to the link. Each of these point-to-point links
// will correspond to a local interface that has an IP address to which
// the node at the root of the SPF tree can send packets. The vertex <v>
// (corresponding to the node that has these links and interfaces) has
// an m_nextHop address precalculated for us that is the address to which the
// root node should send packets to be forwarded to these IP addresses.
// Similarly, the vertex <v> has an m_rootOif (outbound interface index) to
// which the packets should be send for forwarding.
//
Ptr<GlobalRouter> router = node->GetObject<GlobalRouter> ();
if (router == 0)
{
continue;
}
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
NS_ASSERT (gr);
// walk through all available exit directions due to ECMP,
// and add host route for each of the exit direction toward
// the vertex 'v'
for (uint32_t i = 0; i < v->GetNRootExitDirections (); i++)
{
SPFVertex::NodeExit_t exit = v->GetRootExitDirection (i);
Ipv4Address nextHop = exit.first;
int32_t outIf = exit.second;
if (outIf >= 0)
{
gr->AddHostRouteTo (lr->GetLinkData (), nextHop,
outIf);
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" adding host route to " << lr->GetLinkData () <<
" using next hop " << nextHop <<
" and outgoing interface " << outIf);
}
else
{
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" NOT able to add host route to " << lr->GetLinkData () <<
" using next hop " << nextHop <<
" since outgoing interface id is negative " << outIf);
}
} // for all routes from the root the vertex 'v'
}
//
// Done adding the routes for the selected node.
//
return;
}
}
}
void
GlobalRouteManagerImpl::SPFIntraAddTransit (SPFVertex* v)
{
NS_LOG_FUNCTION (this << v);
NS_ASSERT_MSG (m_spfroot,
"GlobalRouteManagerImpl::SPFIntraAddTransit (): Root pointer not set");
//
// The root of the Shortest Path First tree is the router to which we are
// going to write the actual routing table entries. The vertex corresponding
// to this router has a vertex ID which is the router ID of that node. We're
// going to use this ID to discover which node it is that we're actually going
// to update.
//
Ipv4Address routerId = m_spfroot->GetVertexId ();
NS_LOG_LOGIC ("Vertex ID = " << routerId);
//
// We need to walk the list of nodes looking for the one that has the router
// ID corresponding to the root vertex. This is the one we're going to write
// the routing information to.
//
NodeList::Iterator i = NodeList::Begin ();
NodeList::Iterator listEnd = NodeList::End ();
for (; i != listEnd; i++)
{
Ptr<Node> node = *i;
//
// The router ID is accessible through the GlobalRouter interface, so we need
// to GetObject for that interface. If there's no GlobalRouter interface,
// the node in question cannot be the router we want, so we continue.
//
Ptr<GlobalRouter> rtr =
node->GetObject<GlobalRouter> ();
if (rtr == 0)
{
NS_LOG_LOGIC ("No GlobalRouter interface on node " <<
node->GetId ());
continue;
}
//
// If the router ID of the current node is equal to the router ID of the
// root of the SPF tree, then this node is the one for which we need to
// write the routing tables.
//
NS_LOG_LOGIC ("Considering router " << rtr->GetRouterId ());
if (rtr->GetRouterId () == routerId)
{
NS_LOG_LOGIC ("setting routes for node " << node->GetId ());
//
// Routing information is updated using the Ipv4 interface. We need to
// GetObject for that interface. If the node is acting as an IP version 4
// router, it should absolutely have an Ipv4 interface.
//
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4,
"GlobalRouteManagerImpl::SPFIntraAddTransit (): "
"GetObject for <Ipv4> interface failed");
//
// Get the Global Router Link State Advertisement from the vertex we're
// adding the routes to. The LSA will have a number of attached Global Router
// Link Records corresponding to links off of that vertex / node. We're going
// to be interested in the records corresponding to point-to-point links.
//
GlobalRoutingLSA *lsa = v->GetLSA ();
NS_ASSERT_MSG (lsa,
"GlobalRouteManagerImpl::SPFIntraAddTransit (): "
"Expected valid LSA in SPFVertex* v");
Ipv4Mask tempmask = lsa->GetNetworkLSANetworkMask ();
Ipv4Address tempip = lsa->GetLinkStateId ();
tempip = tempip.CombineMask (tempmask);
Ptr<GlobalRouter> router = node->GetObject<GlobalRouter> ();
if (router == 0)
{
continue;
}
Ptr<Ipv4GlobalRouting> gr = router->GetRoutingProtocol ();
NS_ASSERT (gr);
// walk through all available exit directions due to ECMP,
// and add host route for each of the exit direction toward
// the vertex 'v'
for (uint32_t i = 0; i < v->GetNRootExitDirections (); i++)
{
SPFVertex::NodeExit_t exit = v->GetRootExitDirection (i);
Ipv4Address nextHop = exit.first;
int32_t outIf = exit.second;
if (outIf >= 0)
{
gr->AddNetworkRouteTo (tempip, tempmask, nextHop, outIf);
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" add network route to " << tempip <<
" using next hop " << nextHop <<
" via interface " << outIf);
}
else
{
NS_LOG_LOGIC ("(Route " << i << ") Node " << node->GetId () <<
" NOT able to add network route to " << tempip <<
" using next hop " << nextHop <<
" since outgoing interface id is negative " << outIf);
}
}
}
}
}
// Derived from quagga ospf_vertex_add_parents ()
//
// This is a somewhat oddly named method (blame quagga). Although you might
// expect it to add a parent *to* something, it actually adds a vertex
// to the list of children *in* each of its parents.
//
// Given a pointer to a vertex, it links back to the vertex's parent that it
// already has set and adds itself to that vertex's list of children.
//
void
GlobalRouteManagerImpl::SPFVertexAddParent (SPFVertex* v)
{
NS_LOG_FUNCTION (this << v);
for (uint32_t i=0;;)
{
SPFVertex* parent;
// check if all parents of vertex v
if ((parent = v->GetParent (i++)) == 0) break;
parent->AddChild (v);
}
}
} // namespace ns3