How to check forwarded Packets in UDPBasicApp in Omnet - udp

Question

How can I modify UDPBasicApp to find duplicates in the messages recieved?
I made these changes to the class UDPBasicApp.cc to add an extra step to check recieved udp data packets like below, but I see no effect in .sca/.vec and does not even show bubbles.
Where could the error be?
void UDPBasicApp::handleMessageWhenUp(cMessage *msg)
{
if (msg->isSelfMessage()) {
ASSERT(msg == selfMsg);
switch (selfMsg->getKind()) {
case START:
processStart();
break;
case SEND:
processSend();
break;
case STOP:
processStop();
break;
default:
throw cRuntimeError("Invalid kind %d in self message", (int)selfMsg->getKind());
}
}
else if (msg->getKind() == UDP_I_DATA) {
// process incoming packet
//-----------------------------------------------------Added step
//std::string currentMsg= "" + msg->getTreeId();
std::string currentPacket= PK(msg)->getName();
if( BF->CheckBloom(currentPacket) == 1) {
numReplayed++;
getParentModule()->bubble("Replayed!!");
EV<<"----------------------WSNode "<<getParentModule()->getIndex() <<": REPLAYED! Dropping Packet\n";
delete msg;
return;
}
else
{
BF->AddToBloom(currentPacket);
numLegit++;
getParentModule()->bubble("Legit.");
EV<<"----------------------WSNode "<<getParentModule()->getIndex() <<":OK. Pass.\n";
}
//-----------------------------------------------------------------------------
processPacket(PK(msg));
}
else if (msg->getKind() == UDP_I_ERROR) {
EV_WARN << "Ignoring UDP error report\n";
delete msg;
}
else {
throw cRuntimeError("Unrecognized message (%s)%s", msg->getClassName(), msg->getName());
}
if (hasGUI()) {
char buf[40];
sprintf(buf, "rcvd: %d pks\nsent: %d pks", numReceived, numSent);
getDisplayString().setTagArg("t", 0, buf);
}
}

Answer 1

Since I don't have enough context about the entities participating in your overall system, I will provide the following idea:
You can add a unique ID to each message of your application by adding the following line to your applications *.msg:
int messageID = simulation.getUniqueNumber();
Now on the receiver side you can have an std::map<int, int> myMap where you store the <id,number-of-occurences>
Each time you receive a message you add the message to the std::map and increment the number-of-occurences
if(this->myMap.count(myMessage->getUniqueID) == 0) /* check whether this ID exists in the map */
{
this->myMap.insert(std::make_pair(myMessage->getUniqueID(), 1)); /* add this id to the map and set the counter to 1 */
}
else
{
this->myMap.at(myMessage->getUniqueID())++; /* add this id to the map and increment the counter */
}
This will allow you to track whether the same message has been forwarded twice, simply by doing:
if(this->myMap.at(myMessage->getUniqueID()) != 1 ) /* the counter is not 1, message has been "seen" more than once */
The tricky thing for you is how do you define whether a message has been seen twice (or more).