/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2005 INRIA

 *

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "ns3/log.h"

#include "ns3/assert.h"

#include "ns3/packet.h"

#include "ns3/node.h"

#include "ns3/boolean.h"

#include "udp-l4-protocol.h"

#include "udp-header.h"

#include "ipv4-end-point-demux.h"

#include "ipv4-end-point.h"

#include "ipv4-l3-protocol.h"

#include "udp-socket-impl.h"

NS_LOG_COMPONENT_DEFINE ("UdpL4Protocol");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (UdpL4Protocol);

/* see http://www.iana.org/assignments/protocol-numbers */

const uint8_t UdpL4Protocol::PROT_NUMBER = 17;

TypeId 

UdpL4Protocol::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::UdpL4Protocol")

    .SetParent<Ipv4L4Protocol> ()

    .AddConstructor<UdpL4Protocol> ()

    .AddAttribute ("CalcChecksum", "If true, we calculate the checksum of outgoing packets"

                   " and verify the checksum of incoming packets.",

                   BooleanValue (false),

                   MakeBooleanAccessor (&UdpL4Protocol::m_calcChecksum),

                   MakeBooleanChecker ())

    ;

  return tid;

}

UdpL4Protocol::UdpL4Protocol ()

  : m_endPoints (new Ipv4EndPointDemux ())

{

  NS_LOG_FUNCTION_NOARGS ();

}

UdpL4Protocol::~UdpL4Protocol ()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void 

UdpL4Protocol::SetNode (Ptr<Node> node)

{

  m_node = node;

}

int 

UdpL4Protocol::GetProtocolNumber (void) const

{

  return PROT_NUMBER;

}

int 

UdpL4Protocol::GetVersion (void) const

{

  return 2;

}

void

UdpL4Protocol::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_endPoints != 0)

    {

      delete m_endPoints;

      m_endPoints = 0;

    }

  m_node = 0;

  Ipv4L4Protocol::DoDispose ();

}

Ptr<Socket>

UdpL4Protocol::CreateSocket (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  Ptr<UdpSocketImpl> socket = CreateObject<UdpSocketImpl> ();

  socket->SetNode (m_node);

  socket->SetUdp (this);

  return socket;

}

Ipv4EndPoint *

UdpL4Protocol::Allocate (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_endPoints->Allocate ();

}

Ipv4EndPoint *

UdpL4Protocol::Allocate (Ipv4Address address)

{

  NS_LOG_FUNCTION (this << address);

  return m_endPoints->Allocate (address);

}

Ipv4EndPoint *

UdpL4Protocol::Allocate (uint16_t port)

{

  NS_LOG_FUNCTION (this << port);

  return m_endPoints->Allocate (port);

}

Ipv4EndPoint *

UdpL4Protocol::Allocate (Ipv4Address address, uint16_t port)

{

  NS_LOG_FUNCTION (this << address << port);

  return m_endPoints->Allocate (address, port);

}

Ipv4EndPoint *

UdpL4Protocol::Allocate (Ipv4Address localAddress, uint16_t localPort,

                         Ipv4Address peerAddress, uint16_t peerPort)

{

  NS_LOG_FUNCTION (this << localAddress << localPort << peerAddress << peerPort);

  return m_endPoints->Allocate (localAddress, localPort,

                                peerAddress, peerPort);

}

void 

UdpL4Protocol::DeAllocate (Ipv4EndPoint *endPoint)

{

  NS_LOG_FUNCTION (this << endPoint);

  m_endPoints->DeAllocate (endPoint);

}

void 

UdpL4Protocol::Receive(Ptr<Packet> packet, 

                       Ipv4Address const &source,

                       Ipv4Address const &destination,

                       Ptr<Ipv4Interface> interface)

{

  NS_LOG_FUNCTION (this << packet << source << destination);

  UdpHeader udpHeader;

  if(m_calcChecksum)

  {

    udpHeader.EnableChecksums();

  }

  udpHeader.InitializeChecksum (source, destination, PROT_NUMBER);

  packet->RemoveHeader (udpHeader);

  if(!udpHeader.IsChecksumOk ())

  {

    NS_LOG_INFO("Bad checksum : dropping packet!");

    return;

  }

  Ipv4EndPointDemux::EndPoints endPoints =

    m_endPoints->Lookup (destination, udpHeader.GetDestinationPort (),

                         source, udpHeader.GetSourcePort (), interface);

  for (Ipv4EndPointDemux::EndPointsI endPoint = endPoints.begin ();

       endPoint != endPoints.end (); endPoint++)

    {

      (*endPoint)->ForwardUp (packet->Copy (), source, udpHeader.GetSourcePort ());

    }

}

void

UdpL4Protocol::Send (Ptr<Packet> packet, 

                     Ipv4Address saddr, Ipv4Address daddr, 

                     uint16_t sport, uint16_t dport)

{

  NS_LOG_FUNCTION (this << packet << saddr << daddr << sport << dport);

  UdpHeader udpHeader;

  if(m_calcChecksum)

  {

    udpHeader.EnableChecksums();

    udpHeader.InitializeChecksum (saddr,

                                  daddr,

                                  PROT_NUMBER);

  }

  udpHeader.SetDestinationPort (dport);

  udpHeader.SetSourcePort (sport);

  packet->AddHeader (udpHeader);

  Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();

  if (ipv4 != 0)

    {

      NS_LOG_LOGIC ("Sending to IP");

      ipv4->Send (packet, saddr, daddr, PROT_NUMBER);

    }

}

}; // namespace ns3