public void handlePackage(Package package)
{
NHLFE_Entry nhlfeEntry = null;
FIB_Entry fibEntry = null;
if (package.labelStack.labels.Any()) //check if stack has any elements
{
if (package.labelStack.labels.Peek().labelNumber == 0) // check if i'm last hop
{
//getting rid of all '0' labels (pushed in penultimate router)
while (package.labelStack.labels.Peek().labelNumber == 0)
{
package.labelStack.labels.Pop();
if (!package.labelStack.labels.Any())
{
break;
}
}
//if there are no labels left all tunnels are over. check fib table and return
if (!package.labelStack.labels.Any())
{
fibEntry = findFibEntry(package.DestinationAddress);
package.Port = (ushort)fibEntry.portOut;
return;
}
}
ILM_Entry ilmEntry = findIlmEntry(package.Port, package.labelStack.labels.Peek().labelNumber);
nhlfeEntry = findNhlfeEntry(ilmEntry.NHLFE_ID);
}
else
{
FEC_Entry fecEntry = findFecEntry(package.DestinationAddress);
if (fecEntry != null) //adding label
{
FTN_Entry ftnEntry = findFtnEntry(fecEntry.FEC);
nhlfeEntry = findNhlfeEntry(ftnEntry.NHLFE_ID);
}
else //forwarding by IPAddress
{
fibEntry = findFibEntry(package.DestinationAddress);
}
}
modifyPackage(package, nhlfeEntry, fibEntry);
}
public FIB_Entry findFibEntry(IPAddress ipAddress)
{
FIB_Entry fibEntry = null;
foreach (FIB_Entry item in FIB_Table)
{
if (ipAddress.ToString().Equals(item.destinationIP))
{
fibEntry = item;
break;
}
}
if (fibEntry == null)
{
Console.WriteLine("No fib found for IP " + ipAddress);
}
return(fibEntry);
}
private void modifyPackage(Package package, NHLFE_Entry nhlfeEntry, FIB_Entry fibEntry)
{
if (nhlfeEntry != null)
{
package.Port = (ushort)nhlfeEntry.portOut;
switch (nhlfeEntry.action)
{
case "swap":
{
package.labelStack.labels.Pop();
Label newLabel = new Label();
newLabel.labelNumber = nhlfeEntry.labelsOut[0];
package.labelStack.labels.Push(newLabel);
break;
}
case "push":
{
if (package.labelStack.labels.Any())
{
package.labelStack.labels.Pop();
}
foreach (ushort label in nhlfeEntry.labelsOut)
{
Label newLabel = new Label();
newLabel.labelNumber = label;
package.labelStack.labels.Push(newLabel);
}
break;
}
case "pop":
{
//pop labels to replace them with '0'
for (int i = 0; i < nhlfeEntry.popDepth; i++)
{
package.labelStack.labels.Pop();
}
// add '0' labels
for (int i = 0; i < nhlfeEntry.popDepth; i++)
{
package.labelStack.labels.Push(new Label(0));
}
break;
}
default:
{
Console.WriteLine("Wrong value in nhlfe.action field for portOut " + package.Port +
" and labelOut " + nhlfeEntry.labelsOut[0]);
return;
}
}
}
else if (fibEntry != null)
{
package.Port = (ushort)fibEntry.portOut;
}
else
{
Console.WriteLine("Couldn't find forwarding information of package coming from port " + package.Port);
}
}
