text: //
  // Copyright (C) 2004 Andras Varga
  //
  // This program is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public License
  // as published by the Free Software Foundation; either version 2
  // of the License, or (at your option) any later version.
  //
  // This program is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  // GNU Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public License
  // along with this program; if not, see <http://www.gnu.org/licenses/>.
  //
  
  #ifndef __INET_PPP_H
  #define __INET_PPP_H
  
  #include "inet/common/INETDefs.h"
  
  #include "inet/linklayer/ppp/PPPFrame_m.h"
  #include "inet/linklayer/common/TxNotifDetails.h"
  #include "inet/common/lifecycle/ILifecycle.h"
  #include "inet/common/lifecycle/NodeStatus.h"
  #include "inet/linklayer/base/MACBase.h"
  
  namespace inet {
  
  class InterfaceEntry;
  class IPassiveQueue;
  
  /**
   * PPP implementation.
   */
  class INET_API PPP : public MACBase
  {
    protected:
      long txQueueLimit = -1;
      cGate *physOutGate = nullptr;
      cChannel *datarateChannel = nullptr;    // nullptr if we're not connected
  
      cQueue txQueue;
      cMessage *endTransmissionEvent = nullptr;
      IPassiveQueue *queueModule = nullptr;
  
      TxNotifDetails notifDetails;
  
      std::string oldConnColor;
  
      // statistics
      long numSent = 0;
      long numRcvdOK = 0;
      long numBitErr = 0;
      long numDroppedIfaceDown = 0;
  
      static simsignal_t txStateSignal;
      static simsignal_t rxPkOkSignal;
      static simsignal_t dropPkIfaceDownSignal;
      static simsignal_t dropPkBitErrorSignal;
      static simsignal_t packetSentToLowerSignal;
      static simsignal_t packetReceivedFromLowerSignal;
      static simsignal_t packetSentToUpperSignal;
      static simsignal_t packetReceivedFromUpperSignal;
  
    protected:
      virtual void startTransmitting(cPacket *msg);
      virtual PPPFrame *encapsulate(cPacket *msg);
      virtual cPacket *decapsulate(PPPFrame *pppFrame);
      virtual void refreshDisplay() const override;
      virtual void refreshOutGateConnection(bool connected);
  
      // cListener function
      virtual void receiveSignal(cComponent *source, simsignal_t signalID, cObject *obj, cObject *details) override;
  
      // MACBase functions
      virtual InterfaceEntry *createInterfaceEntry() override;
      virtual bool isUpperMsg(cMessage *msg) override { return msg->arrivedOn("netwIn"); }
      virtual void flushQueue() override;
      virtual void clearQueue() override;
  
    public:
      virtual ~PPP();
  
    protected:
      virtual int numInitStages() const override { return NUM_INIT_STAGES; }
      virtual void initialize(int stage) override;
      virtual void handleMessage(cMessage *msg) override;
  };
  
  } // namespace inet
  
  #endif // ifndef __INET_PPP_H
  
  