/// <summary>
/// Handles the request route caching.
/// </summary>
/// <param name="repMessage">The request message.</param>
public void HandleReplyRoute(AodvRouteReplyMessage repMessage)
{
// search for already cached route
var route = (AodvTableEntry)this.GetRouteFor(repMessage.Sender);
// add route if route doesn't exist
if (route == null)
{
// add route to table
this.AddRouteEntry(
repMessage.Sender,
repMessage.LastHop,
repMessage.HopCount + 1,
(AodvSequence)repMessage.ReceiverSequenceNr.Clone());
}
else
{
// if route exists check if sequencenr of request is newer - information in message is newer
if (repMessage.ReceiverSequenceNr.CompareTo(route.SequenceNr) == 1)
{
if (repMessage.HopCount + 1 < route.Metric)
{
// remove route and add new one
this.Entries.Remove(route);
// add new route
this.AddRouteEntry(
repMessage.Sender,
repMessage.LastHop,
repMessage.HopCount + 1,
(AodvSequence)repMessage.ReceiverSequenceNr.Clone());
}
}
}
// handle active neighbour list of route
route = (AodvTableEntry)this.GetRouteFor(repMessage.Sender);
// add repmessage sender to active neighbours of route
if (!route.ActiveNeighbours.ContainsKey(repMessage.Sender))
{
route.ActiveNeighbours.Add(repMessage.Sender, 0);
}
// add repmessage last hop to active neighbours of route
if (!route.ActiveNeighbours.ContainsKey(repMessage.LastHop))
{
route.ActiveNeighbours.Add(repMessage.LastHop, 0);
}
}
private void IncomingAodvRouteReplyMessageHandler(NetSimMessage message)
{
AodvRouteReplyMessage repMessage = (AodvRouteReplyMessage)message;
var aodvTable = this.Table as AodvTable;
// handle the neighbour lsit update - inactive timer management
this.UpdateNeighbourList(repMessage.Sender);
this.UpdateNeighbourList(repMessage.LastHop);
// save found route to table
aodvTable?.HandleReplyRoute(repMessage);
// check if the respone is not for this node . then forward
if (!repMessage.Receiver.Equals(this.Client.Id))
{
// update reply message - increase hopcount and update last hop
repMessage.LastHop = this.Client.Id;
repMessage.HopCount += 1;
// forward message
this.SendMessage(repMessage);
}
}
private void IncomingAodvRouteRequestMessageHandler(NetSimMessage message)
{
AodvTable aodvTable = (AodvTable)this.Table;
AodvRouteRequestMessage reqMessage = (AodvRouteRequestMessage)message;
// if this node was sender of request - or has already a cached version of request
if (this.IsOwnRequest(reqMessage) || this.HasCachedRequest(reqMessage))
{
// ignore message and proceed
return;
}
// add request to cache
this.AddCachedRequest(reqMessage);
// add reverse routing entry - if route doesn't exist or sequencenr is newer
aodvTable.HandleRequestReverseRouteCaching(reqMessage);
// update request message - increase hopcount and update last hop
reqMessage.LastHop = this.Client.Id;
reqMessage.HopCount += 1;
// check if message destination is current node
if (reqMessage.Receiver.Equals(this.Client.Id))
{
// send back rrep mesage the reverse way
var response = new AodvRouteReplyMessage()
{
Receiver = reqMessage.Sender,
Sender = this.Client.Id,
ReceiverSequenceNr = (AodvSequence)this.CurrentSequence.Clone(),
LastHop = this.Client.Id
};
// enqueue message for sending
this.SendMessage(response);
}
else
{
// Check if route was cached
var searchRoute = aodvTable.SearchCachedRoute(reqMessage);
if (searchRoute != null)
{
// send reply back to requester - send back rrep mesage the reverse way
var response = new AodvRouteReplyMessage()
{
Receiver = reqMessage.Sender,
Sender = searchRoute.Destination,
ReceiverSequenceNr = (AodvSequence)searchRoute.SequenceNr.Clone(),
HopCount = searchRoute.Metric,
LastHop = this.Client.Id
};
// enqueue message for sending
this.SendMessage(response);
}
else
{
// forward message to outgoing messages
this.SendMessage(reqMessage);
}
}
}
