RoutingTable6 Class Reference

#include <RoutingTable6.h>

List of all members.

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Detailed Description

Represents the IPv6 routing table and neighbour discovery data structures. This object has one instance per host or router.

See the NED documentation for general overview.

This is a simple module without gates, it requires function calls to it (message handling does nothing). Methods are provided for reading and updating the interface table and the route table, as well as for unicast and multicast routing.

The route table is read from a file. The route table can also be read and modified during simulation, typically by routing protocol implementations.

Public Member Functions
	RoutingTable6 ()
virtual	~RoutingTable6 ()
bool	isRouter () const
Interfaces
InterfaceEntry *	interfaceByAddress (const IPv6Address &address)
Routing functions
bool	localDeliver (const IPv6Address &dest)
const IPv6Address &	lookupDestCache (const IPv6Address &dest, int &outInterfaceId)
const IPv6Route *	doLongestPrefixMatch (const IPv6Address &dest)
bool	isPrefixPresent (const IPv6Address &prefix)
Managing the destination cache
void	updateDestCache (const IPv6Address &dest, const IPv6Address &nextHopAddr, int interfaceId)
void	purgeDestCache ()
void	purgeDestCacheEntriesToNeighbour (const IPv6Address &nextHopAddr, int interfaceId)
Managing prefixes and the route table
void	addOrUpdateOnLinkPrefix (const IPv6Address &destPrefix, int prefixLength, int interfaceId, simtime_t expiryTime)
void	removeOnLinkPrefix (const IPv6Address &destPrefix, int prefixLength)
void	addOrUpdateOwnAdvPrefix (const IPv6Address &destPrefix, int prefixLength, int interfaceId, simtime_t expiryTime)
void	addStaticRoute (const IPv6Address &destPrefix, int prefixLength, unsigned int interfaceId, const IPv6Address &nextHop, int metric=0)
void	addDefaultRoute (const IPv6Address &raSrcAddr, unsigned int ifID, simtime_t routerLifetime)
void	addRoutingProtocolRoute (IPv6Route *route)
void	removeRoute (IPv6Route *route)
int	numRoutes () const
IPv6Route *	route (int i)
Protected Member Functions
void	updateDisplayString ()
int	numInitStages () const
void	initialize (int stage)
void	parseXMLConfigFile ()
void	handleMessage (cMessage *)
Private Types
typedef std::map< IPv6Address, DestCacheEntry >	DestCache
typedef std::vector< IPv6Route * >	RouteList
Private Member Functions
void	addRoute (IPv6Route *route)
void	configureInterfaceForIPv6 (InterfaceEntry *ie)
void	assignRequiredNodeAddresses (InterfaceEntry *ie)
void	configureInterfaceFromXML (InterfaceEntry *ie, cXMLElement *cfg)
Static Private Member Functions
static bool	routeLessThan (const IPv6Route *a, const IPv6Route *b)
Private Attributes
InterfaceTable *	ift
bool	isrouter
DestCache	destCache
RouteList	routeList
Friends
std::ostream &	operator<< (std::ostream &os, const DestCacheEntry &e)
Classes
struct	DestCacheEntry

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Member Typedef Documentation

typedef std::map<IPv6Address,DestCacheEntry> RoutingTable6::DestCache [private]

typedef std::vector<IPv6Route*> RoutingTable6::RouteList [private]

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Constructor & Destructor Documentation

RoutingTable6::RoutingTable6 (   )

{ }

RoutingTable6::~RoutingTable6 (   )  [virtual]

{ for (unsigned int i=0; i<routeList.size(); i++) delete routeList[i]; }

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Member Function Documentation

void RoutingTable6::addDefaultRoute (  const IPv6Address &  raSrcAddr, unsigned int  ifID, simtime_t  routerLifetime )

Adds a default route for a host. This method requires the RA's source address and the router expiry time plus the simTime(). { // create route object IPv6Route *route = new IPv6Route(IPv6Address(), 0, IPv6Route::FROM_RA); route->setInterfaceID(ifID); route->setNextHop(nextHop); route->setMetric(10);//FIXME:should be filled from interface metric // then add it addRoute(route); }

void RoutingTable6::addOrUpdateOnLinkPrefix (  const IPv6Address &  destPrefix, int  prefixLength, int  interfaceId, simtime_t  expiryTime )

Add on-link prefix (route of type FROM_RA), or update existing one. To be called from code processing on-link prefixes in Router Advertisements. Expiry time can be derived from the Valid Lifetime field in the Router Advertisements. NOTE: This method does NOT update the lifetime of matching addresses in the InterfaceTable (see IPv6InterfaceData); that has to be done separately. { // see if prefix exists in table IPv6Route *route = NULL; for (RouteList::iterator it=routeList.begin(); it!=routeList.end(); it++) { if ((*it)->src()==IPv6Route::FROM_RA && (*it)->destPrefix()==destPrefix && (*it)->prefixLength()==prefixLength) { route = *it; break; } } if (route==NULL) { // create new route object IPv6Route *route = new IPv6Route(destPrefix, prefixLength, IPv6Route::FROM_RA); route->setInterfaceID(interfaceId); route->setExpiryTime(expiryTime); route->setMetric(0); // then add it addRoute(route); } else { // update existing one route->setInterfaceID(interfaceId); route->setExpiryTime(expiryTime); } updateDisplayString(); }

void RoutingTable6::addOrUpdateOwnAdvPrefix (  const IPv6Address &  destPrefix, int  prefixLength, int  interfaceId, simtime_t  expiryTime )

Add route of type OWN_ADV_PREFIX. This is a prefix that *this* router advertises on this interface. { // FIXME this is very similar to the one above -- refactor!! // see if prefix exists in table IPv6Route *route = NULL; for (RouteList::iterator it=routeList.begin(); it!=routeList.end(); it++) { if ((*it)->src()==IPv6Route::OWN_ADV_PREFIX && (*it)->destPrefix()==destPrefix && (*it)->prefixLength()==prefixLength) { route = *it; break; } } if (route==NULL) { // create new route object IPv6Route *route = new IPv6Route(destPrefix, prefixLength, IPv6Route::OWN_ADV_PREFIX); route->setInterfaceID(interfaceId); route->setExpiryTime(expiryTime); route->setMetric(0); // then add it addRoute(route); } else { // update existing one route->setInterfaceID(interfaceId); route->setExpiryTime(expiryTime); } updateDisplayString(); }

void RoutingTable6::addRoute (  IPv6Route *  route  )  [private]

{ routeList.push_back(route); // we keep entries sorted by prefix length in routeList, so that we can // stop at the first match when doing the longest prefix matching std::sort(routeList.begin(), routeList.end(), routeLessThan); updateDisplayString(); }

void RoutingTable6::addRoutingProtocolRoute (  IPv6Route *  route  )

Adds the given route (which can be OSPF, BGP, RIP or any other route) with src==ROUTING_PROT. To store additional information with the route, one can subclass from IPv6Route and add more fields. { ASSERT(route->src()==IPv6Route::ROUTING_PROT); addRoute(route); }

void RoutingTable6::addStaticRoute (  const IPv6Address &  destPrefix, int  prefixLength, unsigned int  interfaceId, const IPv6Address &  nextHop, int  metric = 0 )

Creates a static route. If metric is omitted, it gets initialized to the interface's metric value. { // create route object IPv6Route *route = new IPv6Route(destPrefix, prefixLength, IPv6Route::STATIC); route->setInterfaceID(interfaceId); route->setNextHop(nextHop); if (metric==0) { metric = 10; // TBD should be filled from interface metric } route->setMetric(metric); // then add it addRoute(route); }

void RoutingTable6::assignRequiredNodeAddresses (  InterfaceEntry *  ie  )  [private]

RFC 3513: Section 2.8 A Node's Required Address Assign the various addresses to the node's respective interface. This should be done when the IPv6 Protocol stack is created. { //RFC 3513 Section 2.8:A Node's Required Addresses /*A host is required to recognize the following addresses as identifying itself:*/ //o The loopback address. if (ie->isLoopback()) { ie->ipv6()->assignAddress(IPv6Address("::1"), false, 0, 0); return; } //o Its required Link-Local Address for each interface. //IPv6Address linkLocalAddr = IPv6Address().formLinkLocalAddress(ie->interfaceToken()); //ie->ipv6()->assignAddress(linkLocalAddr, true, 0, 0); /*o Any additional Unicast and Anycast Addresses that have been configured for the node's interfaces (manually or automatically).*/ // FIXME FIXME Andras: commented out the following lines, because these addresses // are implicitly checked for in localDeliver() (we don't want redundancy, // and manually adding solicited-node mcast address for each and every address // is very error-prone!) // //o The All-Nodes Multicast Addresses defined in section 2.7.1. /*o The Solicited-Node Multicast Address for each of its unicast and anycast addresses.*/ //o Multicast Addresses of all other groups to which the node belongs. /*A router is required to recognize all addresses that a host is required to recognize, plus the following addresses as identifying itself:*/ /*o The Subnet-Router Anycast Addresses for all interfaces for which it is configured to act as a router.*/ //o All other Anycast Addresses with which the router has been configured. //o The All-Routers Multicast Addresses defined in section 2.7.1. }

void RoutingTable6::configureInterfaceForIPv6 (  InterfaceEntry *  ie  )  [private]

{ IPv6InterfaceData *ipv6IfData = new IPv6InterfaceData(); ie->setIPv6Data(ipv6IfData); // for routers, turn on advertisements by default //FIXME: we will use this isRouter flag for now. what if future implementations //have 2 interfaces where one interface is configured as a router and the other //as a host? ipv6IfData->setAdvSendAdvertisements(isrouter);//Added by WEI // metric: some hints: OSPF cost (2e9/bps value), MS KB article Q299540, ... //d->setMetric((int)ceil(2e9/ie->datarate())); // use OSPF cost as default //FIXME TBD fill in the rest assignRequiredNodeAddresses(ie); }

void RoutingTable6::configureInterfaceFromXML (  InterfaceEntry *  ie, cXMLElement *  cfg )  [private]

{ /*XML parsing capabilities tweaked by WEI. For now, we can configure a specific node's interface. We can set advertising prefixes and other variables to be used in RAs. The IPv6 interface data gets overwritten if lines 249 to 262 is uncommented. The fix is to create an XML file with all the default values. Customised XML files can be used for future protocols that requires different values. (MIPv6)*/ IPv6InterfaceData *d = ie->ipv6(); // parse basic config (attributes) d->setAdvSendAdvertisements(toBool(getRequiredAttr(cfg, "AdvSendAdvertisements"))); //TODO: leave this off first!! They overwrite stuff! /* TODO: Wei commented out the stuff below. To be checked why (Andras). d->setMaxRtrAdvInterval(OPP_Global::atod(getRequiredAttr(cfg, "MaxRtrAdvInterval"))); d->setMinRtrAdvInterval(OPP_Global::atod(getRequiredAttr(cfg, "MinRtrAdvInterval"))); d->setAdvManagedFlag(toBool(getRequiredAttr(cfg, "AdvManagedFlag"))); d->setAdvOtherConfigFlag(toBool(getRequiredAttr(cfg, "AdvOtherConfigFlag"))); d->setAdvLinkMTU(OPP_Global::atoul(getRequiredAttr(cfg, "AdvLinkMTU"))); d->setAdvReachableTime(OPP_Global::atoul(getRequiredAttr(cfg, "AdvReachableTime"))); d->setAdvRetransTimer(OPP_Global::atoul(getRequiredAttr(cfg, "AdvRetransTimer"))); d->setAdvCurHopLimit(OPP_Global::atoul(getRequiredAttr(cfg, "AdvCurHopLimit"))); d->setAdvDefaultLifetime(OPP_Global::atoul(getRequiredAttr(cfg, "AdvDefaultLifetime"))); ie->setMtu(OPP_Global::atoul(getRequiredAttr(cfg, "HostLinkMTU"))); d->setCurHopLimit(OPP_Global::atoul(getRequiredAttr(cfg, "HostCurHopLimit"))); d->setBaseReachableTime(OPP_Global::atoul(getRequiredAttr(cfg, "HostBaseReachableTime"))); d->setRetransTimer(OPP_Global::atoul(getRequiredAttr(cfg, "HostRetransTimer"))); d->setDupAddrDetectTransmits(OPP_Global::atoul(getRequiredAttr(cfg, "HostDupAddrDetectTransmits"))); */ // parse prefixes (AdvPrefix elements; they should be inside an AdvPrefixList // element, but we don't check that) cXMLElementList prefixList = cfg->getElementsByTagName("AdvPrefix"); for (unsigned int i=0; i<prefixList.size(); i++) { cXMLElement *node = prefixList[i]; IPv6InterfaceData::AdvPrefix prefix; // FIXME todo implement: advValidLifetime, advPreferredLifetime can // store (absolute) expiry time (if >0) or lifetime (delta) (if <0); // 0 should be treated as infinity int pfxLen; if (!prefix.prefix.tryParseAddrWithPrefix(node->getNodeValue(),pfxLen)) opp_error("element <%s> at %s: wrong IPv6Address/prefix syntax %s", node->getTagName(), node->getSourceLocation(), node->getNodeValue()); prefix.prefixLength = pfxLen; prefix.advValidLifetime = OPP_Global::atoul(getRequiredAttr(node, "AdvValidLifetime")); prefix.advOnLinkFlag = toBool(getRequiredAttr(node, "AdvOnLinkFlag")); prefix.advPreferredLifetime = OPP_Global::atoul(getRequiredAttr(node, "AdvPreferredLifetime")); prefix.advAutonomousFlag = toBool(getRequiredAttr(node, "AdvAutonomousFlag")); d->addAdvPrefix(prefix); } // parse addresses cXMLElementList addrList = cfg->getChildrenByTagName("inetAddr"); for (unsigned int k=0; k<addrList.size(); k++) { cXMLElement *node = addrList[k]; IPv6Address address(node->getNodeValue()); //We can now decide if the address is tentative or not. d->assignAddress(address, toBool(getRequiredAttr(node, "tentative")), 0, 0); // set up with infinite lifetimes } }

const IPv6Route * RoutingTable6::doLongestPrefixMatch (  const IPv6Address &  dest  )

Performs longest prefix match in the routing table and returns the resulting route, or NULL if there was no match. { Enter_Method("doLongestPrefixMatch(%s)", dest.str().c_str()); // we'll just stop at the first match, because the table is sorted // by prefix lengths and metric (see addRoute()) for (RouteList::iterator it=routeList.begin(); it!=routeList.end(); it++) { if (dest.matches((*it)->destPrefix(),(*it)->prefixLength())) { // FIXME proofread this code, iterator invalidation-wise, etc bool entryExpired = false; if (simTime() > (*it)->expiryTime() && (*it)->expiryTime() != 0)//since 0 represents infinity. { EV << "Expired prefix detected!!" << endl; removeOnLinkPrefix((*it)->destPrefix(), (*it)->prefixLength()); entryExpired = true; } if (entryExpired == false) return *it; } } // FIXME todo: if we selected an expired route, throw it out and select again! return NULL; }

void RoutingTable6::handleMessage (  cMessage *   )  [protected]

Raises an error. { opp_error("This module doesn't process messages"); }

void RoutingTable6::initialize (  int  stage  )  [protected]

{ if (stage==1) { ift = InterfaceTableAccess().get(); WATCH_PTRVECTOR(routeList); WATCH_MAP(destCache); // FIXME commented out for now isrouter = par("isRouter"); WATCH(isrouter); // add IPv6InterfaceData to interfaces for (int i=0; i<ift->numInterfaces(); i++) { InterfaceEntry *ie = ift->interfaceAt(i); configureInterfaceForIPv6(ie); } parseXMLConfigFile(); // skip hosts if (isrouter) { // add globally routable prefixes to routing table for (int x = 0; x < ift->numInterfaces(); x++) { InterfaceEntry *ie = ift->interfaceAt(x); if (ie->isLoopback()) continue; for (int y = 0; y < ie->ipv6()->numAdvPrefixes(); y++) if (ie->ipv6()->advPrefix(y).prefix.isGlobal()) addOrUpdateOwnAdvPrefix(ie->ipv6()->advPrefix(y).prefix, ie->ipv6()->advPrefix(y).prefixLength, x, 0); } } } else if (stage==4) { // configurator adds routes only in stage==3 updateDisplayString(); } }

InterfaceEntry * RoutingTable6::interfaceByAddress (  const IPv6Address &  address  )

Returns an interface given by its address. Returns NULL if not found. { Enter_Method("interfaceByAddress(%s)=?", addr.str().c_str()); if (addr.isUnspecified()) return NULL; for (int i=0; i<ift->numInterfaces(); ++i) { InterfaceEntry *ie = ift->interfaceAt(i); if (ie->ipv6()->hasAddress(addr)) return ie; } return NULL; }

bool RoutingTable6::isPrefixPresent (  const IPv6Address &  prefix  )

Checks if the given prefix already exists in the routing table (prefix list) { for (RouteList::iterator it=routeList.begin(); it!=routeList.end(); it++) if (prefix.matches((*it)->destPrefix(),128)) return true; return false; }

bool RoutingTable6::isRouter (   )  const [inline]

IP forwarding on/off {return isrouter;}

bool RoutingTable6::localDeliver (  const IPv6Address &  dest  )

Checks if the address is one of the host's addresses, i.e. assigned to one of its interfaces (tentatively or not). { Enter_Method("localDeliver(%s) y/n", dest.str().c_str()); // first, check if we have an interface with this address for (int i=0; i<ift->numInterfaces(); i++) { InterfaceEntry *ie = ift->interfaceAt(i); if (ie->ipv6()->hasAddress(dest)) return true; } // then check for special, preassigned multicast addresses // (these addresses occur more rarely than specific interface addresses, // that's why we check for them last) if (dest==IPv6Address::ALL_NODES_1 || dest==IPv6Address::ALL_NODES_2) return true; if (isRouter() && (dest==IPv6Address::ALL_ROUTERS_1 || dest==IPv6Address::ALL_ROUTERS_2 || dest==IPv6Address::ALL_ROUTERS_5)) return true; // check for solicited-node multicast address if (dest.matches(IPv6Address::SOLICITED_NODE_PREFIX, 104)) { for (int i=0; i<ift->numInterfaces(); i++) { InterfaceEntry *ie = ift->interfaceAt(i); if (ie->ipv6()->matchesSolicitedNodeMulticastAddress(dest)) return true; } } return false; }

const IPv6Address & RoutingTable6::lookupDestCache (  const IPv6Address &  dest, int &  outInterfaceId )

Looks up the given destination address in the Destination Cache, then returns the next-hop address and the interface in the outInterfaceId variable. If the destination is not in the cache, outInterfaceId is set to -1 and the unspecified address is returned. The caller should check for interfaceId==-1, because unspecified address is also returned if the link layer doesn't use addresses at all (e.g. PPP). NOTE: outInterfaceId is an OUTPUT parameter -- its initial value is ignored, and the lookupDestCache() sets it to the correct value instead. { Enter_Method("lookupDestCache(%s)", dest.str().c_str()); DestCache::iterator it = destCache.find(dest); if (it == destCache.end()) { outInterfaceId = -1; return IPv6Address::UNSPECIFIED_ADDRESS; } outInterfaceId = it->second.interfaceId; return it->second.nextHopAddr; }

int RoutingTable6::numInitStages (   )  const [inline, protected]

{return 5;}

int RoutingTable6::numRoutes (   )  const

Return the number of routes. { return routeList.size(); }

void RoutingTable6::parseXMLConfigFile (   )  [protected]

{ // TODO to be revised by Andras // configure interfaces from XML config file cXMLElement *config = par("routingTableFile"); for (cXMLElement *child=config->getFirstChild(); child; child = child->getNextSibling()) { //std::cout << "configuring interfaces from XML file." << endl; //std::cout << "selected element is: " << child->getTagName() << endl; // we ensure that the selected element is local. if (opp_strcmp(child->getTagName(),"local")!=0) continue; //ensure that this is the right parent module we are configuring. if (opp_strcmp(child->getAttribute("node"),parentModule()->fullName())!=0) continue; //Go one level deeper. //child = child->getFirstChild(); for (cXMLElement *ifTag=child->getFirstChild(); ifTag; ifTag = ifTag->getNextSibling()) { //The next tag should be "interface". if (opp_strcmp(ifTag->getTagName(),"interface")!=0) continue; //std::cout << "Getting attribute: name" << endl; const char *ifname = ifTag->getAttribute("name"); if (!ifname) error("<interface> without name attribute at %s", child->getSourceLocation()); InterfaceEntry *ie = ift->interfaceByName(ifname); if (!ie) error("no interface named %s was registered, %s", ifname, child->getSourceLocation()); configureInterfaceFromXML(ie, ifTag); } } }

void RoutingTable6::purgeDestCache (   )

Discard all entries in destination cache { destCache.clear(); updateDisplayString(); }

void RoutingTable6::purgeDestCacheEntriesToNeighbour (  const IPv6Address &  nextHopAddr, int  interfaceId )

Discard all entries in destination cache where next hop is the given address on the given interface. This is typically called when a router becomes unreachable, and all destinations going via that router have to go though router selection again. { for (DestCache::iterator it=destCache.begin(); it!=destCache.end(); ) { if (it->second.interfaceId==interfaceId && it->second.nextHopAddr==nextHopAddr) { // move the iterator past this element before removing it DestCache::iterator oldIt = it++; destCache.erase(oldIt); } else { it++; } } updateDisplayString(); }

void RoutingTable6::removeOnLinkPrefix (  const IPv6Address &  destPrefix, int  prefixLength )

Remove an on-link prefix. To be called when the prefix gets advertised with zero lifetime, or to purge an expired prefix. NOTE: This method does NOT remove the matching addresses from the InterfaceTable (see IPv6InterfaceData); that has to be done separately. { // scan the routing table for this prefix and remove it for (RouteList::iterator it=routeList.begin(); it!=routeList.end(); it++) { if ((*it)->src()==IPv6Route::FROM_RA && (*it)->destPrefix()==destPrefix && (*it)->prefixLength()==prefixLength) { routeList.erase(it); return; // there can be only one such route, addOrUpdateOnLinkPrefix() guarantees that } } updateDisplayString(); }

void RoutingTable6::removeRoute (  IPv6Route *  route  )

Deletes the given route from the route table. { RouteList::iterator it = std::find(routeList.begin(), routeList.end(), route); ASSERT(it!=routeList.end()); routeList.erase(it); updateDisplayString(); }

IPv6Route * RoutingTable6::route (  int  i  )

Return the ith route. { ASSERT(i>=0 && i<routeList.size()); return routeList[i]; }

bool RoutingTable6::routeLessThan (  const IPv6Route *  a, const IPv6Route *  b )  [static, private]

{ // helper for sort() in addRoute(). We want routes with longer // prefixes to be at front, so we compare them as "less". // For metric, a smaller value is better (we report that as "less"). if (a->prefixLength()!=b->prefixLength()) return a->prefixLength() > b->prefixLength(); return a->metric() < b->metric(); }

void RoutingTable6::updateDestCache (  const IPv6Address &  dest, const IPv6Address &  nextHopAddr, int  interfaceId )

Add or update a destination cache entry. { // FIXME this performs 2 lookups -- optimize to do only one destCache[dest].nextHopAddr = nextHopAddr; destCache[dest].interfaceId = interfaceId; updateDisplayString(); }

void RoutingTable6::updateDisplayString (   )  [protected]

{ if (!ev.isGUI()) return; char buf[80]; sprintf(buf, "%d routes\n%d destcache entries", numRoutes(), destCache.size()); displayString().setTagArg("t",0,buf); }

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Friends And Related Function Documentation

std::ostream& operator<< (  std::ostream &  os, const DestCacheEntry &  e )  [friend]

{ os << "if=" << e.interfaceId << " " << e.nextHopAddr; //FIXME try printing interface name return os; };

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Member Data Documentation

DestCache RoutingTable6::destCache [private]

InterfaceTable* RoutingTable6::ift [private]

bool RoutingTable6::isrouter [private]

RouteList RoutingTable6::routeList [private]

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The documentation for this class was generated from the following files:

• RoutingTable6.h
• RoutingTable6.cc

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