BaseNetwLayer.cc

/***************************************************************************
 * file:        BaseNetwLayer.cc
 *
 * author:      Daniel Willkomm
 *
 * copyright:   (C) 2004 Telecommunication Networks Group (TKN) at
 *              Technische Universitaet Berlin, Germany.
 *
 *              This program is free software; you can redistribute it
 *              and/or modify it under the terms of the GNU General Public
 *              License as published by the Free Software Foundation; either
 *              version 2 of the License, or (at your option) any later
 *              version.
 *              For further information see file COPYING
 *              in the top level directory
 ***************************************************************************
 * part of:     framework implementation developed by tkn
 * description: network layer: general class for the network layer
 *              subclass to create your own network layer
 ***************************************************************************/


#include "BaseNetwLayer.h"
#include "NetwControlInfo.h"
#include "NetwToMacControlInfo.h"
#include "BaseMacLayer.h"
#include "AddressingInterface.h"

#include <cassert>

Define_Module(BaseNetwLayer);

void BaseNetwLayer::initialize(int stage)
{
    BaseLayer::initialize(stage);

    if(stage==0){
      coreDebug = par("coreDebug").boolValue();
        headerLength= par("headerLength");
        arp = FindModule<ArpInterface*>::findSubModule(findHost());
    }
    else if(stage == 1) {
      // see if there is an addressing module available
      // otherwise use module id as network address
        AddressingInterface* addrScheme = FindModule<AddressingInterface*>
													::findSubModule(findHost());
        if(addrScheme) {
          myNetwAddr = addrScheme->myNetwAddr(this);
        } else {
          myNetwAddr = getId();
        }
        coreEV << " myNetwAddr " << myNetwAddr << endl;
    }
}

cMessage* BaseNetwLayer::decapsMsg(NetwPkt *msg)
{
    cMessage *m = msg->decapsulate();
    m->setControlInfo(new NetwControlInfo(msg->getSrcAddr()));
    // delete the netw packet
    delete msg;
    return m;
}


NetwPkt* BaseNetwLayer::encapsMsg(cPacket *appPkt) {
    int macAddr;
    int netwAddr;

    coreEV <<"in encaps...\n";

    NetwPkt *pkt = new NetwPkt(appPkt->getName(), appPkt->getKind());
    pkt->setBitLength(headerLength);

    NetwControlInfo* cInfo = dynamic_cast<NetwControlInfo*>(appPkt->removeControlInfo());

    if(cInfo == 0){
  EV << "warning: Application layer did not specifiy a destination L3 address\n"
     << "\tusing broadcast address instead\n";
  netwAddr = L3BROADCAST;
    } else {
  coreEV <<"CInfo removed, netw addr="<< cInfo->getNetwAddr()<<endl;
        netwAddr = cInfo->getNetwAddr();
  delete cInfo;
    }

    pkt->setSrcAddr(myNetwAddr);
    pkt->setDestAddr(netwAddr);
    coreEV << " netw "<< myNetwAddr << " sending packet" <<endl;
    if(netwAddr == L3BROADCAST) {
        coreEV << "sendDown: nHop=L3BROADCAST -> message has to be broadcasted"
           << " -> set destMac=L2BROADCAST\n";
        macAddr = L2BROADCAST;
    }
    else{
        coreEV <<"sendDown: get the MAC address\n";
        macAddr = arp->getMacAddr(netwAddr);
    }

    pkt->setControlInfo(new NetwToMacControlInfo(macAddr));

    //encapsulate the application packet
    pkt->encapsulate(appPkt);
    coreEV <<" pkt encapsulated\n";
    return pkt;
}

void BaseNetwLayer::handleLowerMsg(cMessage* msg)
{
    NetwPkt *m = static_cast<NetwPkt *>(msg);
    coreEV << " handling packet from " << m->getSrcAddr() << endl;
    sendUp(decapsMsg(m));
}

void BaseNetwLayer::handleUpperMsg(cMessage* msg)
{
  assert(dynamic_cast<cPacket*>(msg));
    sendDown(encapsMsg(static_cast<cPacket*>(msg)));
}

void BaseNetwLayer::handleLowerControl(cMessage* msg)
{
  switch (msg->getKind())
  {
  case BaseMacLayer::TX_OVER:
    delete msg;
    break;
  default:
    EV << "BaseNetwLayer does not handle control messages called "
       << msg->getName() << endl;
    delete msg;
  }
}