/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright 2007 University of Washington
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author:  Tom Henderson (tomhend@u.washington.edu)
 */

#ifndef PACKET_SINK_H
#define PACKET_SINK_H

#include "ns3/application.h"
#include "ns3/event-id.h"
#include "ns3/ptr.h"
#include "ns3/traced-callback.h"
#include "ns3/address.h"

namespace ns3 {

class Address;
class Socket;
class Packet;

/**
 * \ingroup applications 
 * \defgroup packetsink PacketSink
 *
 * This application was written to complement OnOffApplication, but it
 * is more general so a PacketSink name was selected.  Functionally it is
 * important to use in multicast situations, so that reception of the layer-2
 * multicast frames of interest are enabled, but it is also useful for
 * unicast as an example of how you can write something simple to receive
 * packets at the application layer.  Also, if an IP stack generates 
 * ICMP Port Unreachable errors, receiving applications will be needed.
 */

/**
 * \ingroup packetsink
 *
 * \brief Receive and consume traffic generated to an IP address and port
 *
 * This application was written to complement OnOffApplication, but it
 * is more general so a PacketSink name was selected.  Functionally it is
 * important to use in multicast situations, so that reception of the layer-2
 * multicast frames of interest are enabled, but it is also useful for
 * unicast as an example of how you can write something simple to receive
 * packets at the application layer.  Also, if an IP stack generates 
 * ICMP Port Unreachable errors, receiving applications will be needed.
 *
 * The constructor specifies the Address (IP address and port) and the 
 * transport protocol to use.   A virtual Receive () method is installed 
 * as a callback on the receiving socket.  By default, when logging is
 * enabled, it prints out the size of packets and their address.
 * A tracing source to Receive() is also available.
 */
class PacketSink : public Application 
{
public:
  /**
   * \brief Get the type ID.
   * \return the object TypeId
   */
  static TypeId GetTypeId (void);
  PacketSink ();

  virtual ~PacketSink ();

  /**
   * \return the total bytes received in this sink app
   */
  uint32_t GetTotalRx () const;

  /**
   * \return pointer to listening socket
   */
  Ptr<Socket> GetListeningSocket (void) const;

  /**
   * \return list of pointers to accepted sockets
   */
  std::list<Ptr<Socket> > GetAcceptedSockets (void) const;
 
protected:
  virtual void DoDispose (void);
private:
  // inherited from Application base class.
  virtual void StartApplication (void);    // Called at time specified by Start
  virtual void StopApplication (void);     // Called at time specified by Stop

  /**
   * \brief Handle a packet received by the application
   * \param socket the receiving socket
   */
  void HandleRead (Ptr<Socket> socket);
  /**
   * \brief Handle an incoming connection
   * \param socket the incoming connection socket
   * \param from the address the connection is from
   */
  void HandleAccept (Ptr<Socket> socket, const Address& from);
  /**
   * \brief Handle an connection close
   * \param socket the connected socket
   */
  void HandlePeerClose (Ptr<Socket> socket);
  /**
   * \brief Handle an connection error
   * \param socket the connected socket
   */
  void HandlePeerError (Ptr<Socket> socket);

  // In the case of TCP, each socket accept returns a new socket, so the 
  // listening socket is stored separately from the accepted sockets
  Ptr<Socket>     m_socket;       //!< Listening socket
  std::list<Ptr<Socket> > m_socketList; //!< the accepted sockets

  Address         m_local;        //!< Local address to bind to
  uint32_t        m_totalRx;      //!< Total bytes received
  TypeId          m_tid;          //!< Protocol TypeId

  /// Traced Callback: received packets, source address.
  TracedCallback<Ptr<const Packet>, const Address &> m_rxTrace;

};

} // namespace ns3

#endif /* PACKET_SINK_H */

