Forwarder Class Reference

#include <Forwarder.h>

Inheritance diagram for Forwarder:

List of all members.

Public Member Functions
	Forwarder ()
Protected Member Functions
virtual void	initialize (int stage)
virtual int	numInitStages () const
virtual void	handleMessage (cMessage *msg)
virtual void	handlePSMsg (PSEtherAppMsg *msg)
Protected Attributes
FwTable *	fwt
	Pointer to the Forwarding Table of the Router.
IInterfaceTable *	ift
	Pointer to the Interface Table of the Router.
int	numMulticast
	Number of multicast packets forwarded.
int	numLocalDeliver
	Number of local packets delivered.
int	numDropped
	Number of Packets dropped.
int	numUnroutable
	Number of Packets unable to be routed.
int	numForwarded
	Number of forwarded packets.
int	numFalsePositives
	Number of the palse positives in the forwarded packets.

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Detailed Description

The Publish Subscribe Forwarder class header Implements the Forwarder for the publish-subscribe network router. This module, on receiving a network message, just checks with the forwarding table if there is any link towards another network interface, with LID matching the received message's FID. If this check returns a number of matching interfaces, the received message is forwarded to all these interfaces.

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Constructor & Destructor Documentation

Forwarder::Forwarder

(

)

[inline]

Constructor

{}

---

Member Function Documentation

void Forwarder::handleMessage

(

cMessage *

msg

)

[protected, virtual]

Processing of messages, received from the link layer.

Reimplemented from cSimpleModule.

{
        //Check is received message is a pub-sub message
        if (dynamic_cast<PSEtherAppMsg *>(msg)) {
                PSEtherAppMsg *PSmsg =  check_and_cast <PSEtherAppMsg *> (msg);

                handlePSMsg(PSmsg);
        }
        //...else delete received message
        else {
                numUnroutable++;
                ev << "Packet with invalid format received... being discarted!!!" << endl;
                delete msg;
        }
        return;
}

void Forwarder::handlePSMsg

(

PSEtherAppMsg *

msg

)

[protected, virtual]

If a message is a pub-sub message, apply the forwarding functions.

                                              {
        ev << "Handling Pub-Sub message... Checking forwarding table..." << endl;

        //Get the list of the network interface gate index that match the message's FID
        list<int> interfaceIDs=fwt->findMatchingRoute(msg->getFID());

        //If we are checking for false positives, record any such occurrence by checking
        //the result given by the Forwarding Table.
        if(simulation.getSystemModule()->par("FP_check").boolValue()==true && msg->getPathArraySize()>0) {

                //Check if the link used for forwarding is inside the messages list
                for(list<int>::iterator it = interfaceIDs.begin(); it != interfaceIDs.end(); it++) {

                        bool found = false;

                        //For all the lids in the message path
                        for(uint i=0;i<msg->getPathArraySize();i++) {
                                //If the searched LID is found in the path, change the flag
                                if(strcmp(msg->getPath(i),fwt->getLID(*it))==0)
                                        found=true;
                        }

                        //If a false positive is found, record it and remove the forwarding link from the list
                        if(!found) {
                                ev << "ATTENTION: False-positive found in the forwarding process!" << endl;
                                numFalsePositives++;
                                //Remove the link from the forwarding list
                                it = interfaceIDs.erase(it);
                                it--;
                        }
                }
        }

        //If the list is not empty
        if(!interfaceIDs.empty()) {

                for (list<int>::iterator it = interfaceIDs.begin(); it != interfaceIDs.end(); it++) {

                        //We shound't send the message back from where it came
                        if(msg->getArrivalGate()->getIndex()!=*it) {
                                ev << "Found a matching LID for interface eth[" <<  *it << "]" << endl;

                                //Creating new copies of the message for each interface and copying the Control Info
                                PSEtherAppMsg *msgcopy=(PSEtherAppMsg *)msg->dup();
                                msgcopy->setControlInfo(new Ieee802Ctrl(*check_and_cast<Ieee802Ctrl *>(msg->getControlInfo())));

                                ev << "Forwarding the message to the interface..." << endl;

                                //Sending message down to the correct interface
                                numForwarded++;
                                send(msgcopy,"ifOut",*it);
                        }
                }
        }
        else {
                numDropped++;
                ev << "No Ethernet interface with matching LID found. Dropping packet." << endl;
        }

        delete msg;
}

void Forwarder::initialize

(

int

stage

)

[protected, virtual]

Initialization

Reimplemented from cComponent.

{
        if(stage==1) {
                //Initialize parent class
                cSimpleModule::initialize(stage);

                //Access Interface and Forwarding Table
                ift = InterfaceTableAccess().get();
                fwt = FwTableAccess().get();

                //Initialize and watch statistics
                numMulticast = numLocalDeliver = numDropped = numUnroutable = numForwarded = numFalsePositives = 0;

                WATCH(numMulticast);
                WATCH(numLocalDeliver);
                WATCH(numDropped);
                WATCH(numUnroutable);
                WATCH(numForwarded);
                WATCH(numFalsePositives);
        }
}

virtual int Forwarder::numInitStages

(

)

const [inline, protected, virtual]

Returns the number of initialization stages.

Reimplemented from cComponent.

{return 4;}

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Member Data Documentation

FwTable* Forwarder::fwt [protected]

Pointer to the Forwarding Table of the Router.

IInterfaceTable* Forwarder::ift [protected]

Pointer to the Interface Table of the Router.

int Forwarder::numDropped [protected]

Number of Packets dropped.

int Forwarder::numFalsePositives [protected]

Number of the palse positives in the forwarded packets.

int Forwarder::numForwarded [protected]

Number of forwarded packets.

int Forwarder::numLocalDeliver [protected]

Number of local packets delivered.

int Forwarder::numMulticast [protected]

Number of multicast packets forwarded.

int Forwarder::numUnroutable [protected]

Number of Packets unable to be routed.

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

• Forwarder.h
• Forwarder.cc