inline bool
operator==(RoutingTableEntry& rhs)
{
return ((*this).getDestination() == rhs.getDestination()
&&
(*this).getNexthopList() == rhs.getNexthopList());
}
RoutingTableEntryList RoutingTable::getPossibleNextHops(const Packet* packet) {
if (isDeliverable(packet->getDestination())) {
AddressPtr source = packet->getSource();
AddressPtr sender = packet->getSender();
RoutingTableEntryList* availableHops = table[packet->getDestination()];
RoutingTableEntryList returnedList = RoutingTableEntryList(*availableHops);
// remove all entries that would route the packet back over the source or sender of the packet (would create a loop)
RoutingTableEntryList::iterator iterator = returnedList.begin();
while (iterator != returnedList.end()) {
RoutingTableEntry* entry = *iterator;
AddressPtr possibleNextHop = entry->getAddress();
if (possibleNextHop->equals(source) || possibleNextHop->equals(sender) ) {
iterator = returnedList.erase(iterator);
}
else {
iterator++;
}
}
return returnedList;
}
else {
// return empty list
return RoutingTableEntryList();
}
}
// function related to manipulation of routing table
void
RoutingTable::addNextHop(const ndn::Name& destRouter, NextHop& nh)
{
_LOG_DEBUG("Adding " << nh << " for destination: " << destRouter);
RoutingTableEntry* rteChk = findRoutingTableEntry(destRouter);
if (rteChk == 0) {
RoutingTableEntry rte(destRouter);
rte.getNexthopList().addNextHop(nh);
m_rTable.push_back(rte);
}
else {
rteChk->getNexthopList().addNextHop(nh);
}
}
void
NamePrefixTable::addEntry(const ndn::Name& name, RoutingTableEntry& rte)
{
NptEntryList::iterator it = std::find_if(m_table.begin(),
m_table.end(),
bind(&npteCompare, _1, name));
if (it == m_table.end()) {
_LOG_TRACE("Adding origin: " << rte.getDestination() << " to new name prefix: " << name);
NamePrefixTableEntry entry(name);
entry.addRoutingTableEntry(rte);
entry.generateNhlfromRteList();
entry.getNexthopList().sort();
m_table.push_back(entry);
if (rte.getNexthopList().getSize() > 0) {
_LOG_TRACE("Updating FIB with next hops for " << entry);
m_nlsr.getFib().update(name, entry.getNexthopList());
}
}
else {
_LOG_TRACE("Adding origin: " << rte.getDestination() << " to existing prefix: " << *it);
it->addRoutingTableEntry(rte);
it->generateNhlfromRteList();
it->getNexthopList().sort();
if (it->getNexthopList().getSize() > 0) {
_LOG_TRACE("Updating FIB with next hops for " << *it);
m_nlsr.getFib().update(name, it->getNexthopList());
}
else {
// The routing table may recalculate and add a routing table entry with no next hops to
// replace an existing routing table entry. In this case, the name prefix is no longer
// reachable through a next hop and should be removed from the FIB. But, the prefix
// should remain in the Name Prefix Table as a future routing table calculation may
// add next hops.
_LOG_TRACE(*it << " has no next hops; removing from FIB");
m_nlsr.getFib().remove(name);
}
}
}
void RoutingTable::applyEvaporation(Time* currentTime) {
long timeDifference = currentTime->getDifferenceInMilliSeconds(lastAccessTime);
delete currentTime;
if (evaporationPolicy->isEvaporationNecessary(timeDifference)) {
lastAccessTime->setToCurrentTime();
RoutingTableMap::iterator i = table.begin();
while (i!=table.end()) {
std::pair<AddressPtr const, RoutingTableEntryList*> entryPair = *i;
AddressPtr destination = entryPair.first;
RoutingTableEntryList* nextHopsForDestination = entryPair.second;
// apply evaporation to all next hops for that destination
RoutingTableEntryList::iterator j = nextHopsForDestination->begin();
while (j != nextHopsForDestination->end()) {
RoutingTableEntry* entry = *j;
float newPheromoneValue = evaporationPolicy->evaporate(entry->getPheromoneValue(), timeDifference);
if (newPheromoneValue > 0) {
entry->setPheromoneValue(newPheromoneValue);
j++;
}
else {
delete entry;
j = nextHopsForDestination->erase(j); // this does not invalidate the iterator, because j is set to the valid return value of erase (will point to end() if empty)
}
}
if (nextHopsForDestination->empty()) {
delete nextHopsForDestination;
i = table.erase(i); // this does not invalidate the iterator, because i is set to the valid return value of erase (will point to end() if empty)
}
else {
i++;
}
}
}
}
void RoutingTable::removeEntry(AddressPtr destination, AddressPtr nextHop, NetworkInterface* interface) {
if (table.find(destination) != table.end()) {
RoutingTableEntryList* entryList = table[destination];
RoutingTableEntryList::iterator iterator = entryList->begin();
if (iterator != entryList->end()) {
while (iterator != entryList->end()) {
RoutingTableEntry* entry = *iterator;
if (entry->getAddress()->equals(nextHop) && entry->getNetworkInterface()->equals(interface)) {
entryList->erase(iterator);
delete entry;
break;
}
iterator++;
}
if (entryList->empty()) {
// this was the last entry so we can delete the whole list
table.erase(destination);
delete entryList;
}
}
}
}
void
NamePrefixTable::removeEntry(const ndn::Name& name, RoutingTableEntry& rte)
{
NptEntryList::iterator it = std::find_if(m_table.begin(),
m_table.end(),
bind(&npteCompare, _1, name));
if (it != m_table.end()) {
_LOG_TRACE("Removing origin: " << rte.getDestination() << " from prefix: " << *it);
it->removeRoutingTableEntry(rte);
// If the prefix is a router prefix and it does not have any other routing table entries,
// the Adjacency/Coordinate LSA associated with that origin router has been removed from
// the LSDB and so the router prefix should be removed from the Name Prefix Table.
//
// If the prefix is an advertised name prefix:
// If another router advertises this name prefix, the RteList should have another entry
// for that router; the next hops should be recalculated and installed in the FIB.
//
// If no other router advertises this name prefix, the RteList should be empty and the
// prefix can be removed from the Name Prefix Table. Once a new Name LSA advertises this
// prefix, a new entry for the prefix will be created.
//
if (it->getRteListSize() == 0) {
_LOG_TRACE(*it << " has no routing table entries; removing from table and FIB");
m_table.erase(it);
m_nlsr.getFib().remove(name);
}
else {
_LOG_TRACE(*it << " has other routing table entries; updating FIB with next hops");
it->generateNhlfromRteList();
it->getNexthopList().sort();
m_nlsr.getFib().update(name, it->getNexthopList());
}
}
}
static bool
routingTableEntryCompare(RoutingTableEntry& rte, ndn::Name& destRouter)
{
return rte.getDestination() == destRouter;
}