/* -*- 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 "udp-echo-server.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("UdpEchoServerApplication");

UdpEchoServer::UdpEchoServer (
  Ptr<Node> n,
  uint16_t port)
: 
  Application(n)
{
  NS_LOG_FUNCTION;
  NS_LOG_PARAM ("(" << n << ", " << port << ")");

  Construct (n, port);
}

UdpEchoServer::~UdpEchoServer()
{
  NS_LOG_FUNCTION;
}

void
UdpEchoServer::Construct (
  Ptr<Node> n,
  uint16_t port)
{
  NS_LOG_FUNCTION;
  NS_LOG_PARAM ("(" << n << ", " << port << ")");

  m_node = n;
  m_port = port;

  m_socket = 0;
  m_local = InetSocketAddress (Ipv4Address::GetAny (), port);
}

void
UdpEchoServer::DoDispose (void)
{
  NS_LOG_FUNCTION;
  Application::DoDispose ();
}

void 
UdpEchoServer::StartApplication (void)
{
  NS_LOG_FUNCTION;

  if (!m_socket)
    {
      InterfaceId iid = InterfaceId::LookupByName ("Udp");
      Ptr<SocketFactory> socketFactory = 
        GetNode ()->QueryInterface<SocketFactory> (iid);
      m_socket = socketFactory->CreateSocket ();
      m_socket->Bind (m_local);
    }

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

void 
UdpEchoServer::StopApplication ()
{
  NS_LOG_FUNCTION;

  if (!m_socket) 
    {
      m_socket->SetRecvCallback(MakeNullCallback<void, Ptr<Socket>, 
        Ptr<Packet>, const Address &> ());
    }
}

void
UdpEchoServer::Receive(
  Ptr<Socket> socket, 
  Ptr<Packet> packet,
  const Address &from) 
{
  NS_LOG_FUNCTION;
  NS_LOG_PARAM ("(" << socket << ", " << packet << ", " << from << ")");

  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 (from, packet);
    }
}

} // Namespace ns3