/* -*- 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

 */

#include "ns3/log.h"

#include "ns3/ipv4-address.h"

#include "ns3/nstime.h"

#include "ns3/inet-socket-address.h"

#include "ns3/socket.h"

#include "ns3/simulator.h"

#include "ns3/socket-factory.h"

#include "ns3/packet.h"

#include "ns3/uinteger.h"

#include "udp-echo-server.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("UdpEchoServerApplication");

NS_OBJECT_ENSURE_REGISTERED (UdpEchoServer);

TypeId

UdpEchoServer::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::UdpEchoServer")

    .SetParent<Application> ()

    .AddConstructor<UdpEchoServer> ()

    .AddAttribute ("Port", "Port on which we listen for incoming packets.",

                   UintegerValue (9),

                   MakeUintegerAccessor (&UdpEchoServer::m_port),

                   MakeUintegerChecker<uint16_t> ())

    ;

  return tid;

}

UdpEchoServer::UdpEchoServer ()

{

  NS_LOG_FUNCTION_NOARGS ();

}

UdpEchoServer::~UdpEchoServer()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void

UdpEchoServer::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  Application::DoDispose ();

}

void 

UdpEchoServer::StartApplication (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (!m_socket)

    {

      m_socket = Socket::CreateSocket (GetNode(), tid);

      InetSocketAddress local = InetSocketAddress (Ipv4Address::GetAny (), m_port);

      m_socket->Bind (local);

    }

  m_socket->SetRecvCallback(MakeCallback(&UdpEchoServer::HandleRead, this));

}

void 

UdpEchoServer::StopApplication ()

{

  NS_LOG_FUNCTION_NOARGS ();

  if (!m_socket) 

    {

      m_socket->SetRecvCallback(MakeNullCallback<void, Ptr<Socket> > ());

    }

}

void 

UdpEchoServer::HandleRead (Ptr<Socket> socket)

{

  Ptr<Packet> packet;

  while (packet = socket->Recv ())

    {

      SocketRxAddressTag tag;

      bool found = packet->PeekTag (tag); 

      NS_ASSERT (found);

      Address from = tag.GetAddress ();

      packet->RemoveTag (tag);

      if (InetSocketAddress::IsMatchingType (from))

        {

          InetSocketAddress address = InetSocketAddress::ConvertFrom (from);

          NS_LOG_INFO ("Received " << packet->GetSize() << " bytes from " << 

            address.GetIpv4());

          NS_LOG_LOGIC ("Echoing packet");

          socket->SendTo (packet, from);

        }

    }

}

} // Namespace ns3