/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2007-2009 Strasbourg University
 *
 * 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: David Gross <gdavid.devel@gmail.com>
 */

#include <list>
#include <ctime>

#include "ns3/log.h"
#include "ns3/assert.h"
#include "ns3/uinteger.h"
#include "ns3/object-vector.h"
#include "ns3/ipv6-address.h"
#include "ns3/ipv6-header.h"
#include "ns3/ipv6-l3-protocol.h"
#include "ns3/ipv6-static-routing.h"
#include "ns3/ipv6-list-routing.h"
#include "ns3/ipv6-route.h"
#include "ns3/trace-source-accessor.h"
#include "ns3/random-variable.h"
#include "icmpv6-l4-protocol.h"
#include "ipv6-extension-demux.h"
#include "ipv6-extension.h"
#include "ipv6-extension-header.h"
#include "ipv6-option-demux.h"
#include "ipv6-option.h"
#include "udp-header.h"

NS_LOG_COMPONENT_DEFINE ("Ipv6Extension");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (Ipv6Extension);

TypeId Ipv6Extension::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6Extension")
    .SetParent<Object> ()
    .AddAttribute ("ExtensionNumber", "The IPv6 extension number.",
                   UintegerValue (0),
                   MakeUintegerAccessor (&Ipv6Extension::GetExtensionNumber),
                   MakeUintegerChecker<uint8_t> ())
    .AddTraceSource ("Drop", "Drop ipv6 packet",
                     MakeTraceSourceAccessor (&Ipv6Extension::m_dropTrace))
  ;
  return tid;
}

Ipv6Extension::~Ipv6Extension ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

void Ipv6Extension::SetNode (Ptr<Node> node)
{
  NS_LOG_FUNCTION (this << node);

  m_node = node;
}

Ptr<Node> Ipv6Extension::GetNode () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return m_node;
}

uint8_t Ipv6Extension::ProcessOptions (Ptr<Packet>& packet, uint8_t offset, uint8_t length, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << length << ipv6Header << dst << nextHeader << isDropped);

  // For ICMPv6 Error packets
  Ptr<Packet> malformedPacket = packet->Copy ();
  malformedPacket->AddHeader (ipv6Header);
  Ptr<Icmpv6L4Protocol> icmpv6 = GetNode ()->GetObject<Ipv6L3Protocol> ()->GetIcmpv6 ();

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  Ptr<Ipv6OptionDemux> ipv6OptionDemux = GetNode ()->GetObject<Ipv6OptionDemux> ();
  Ptr<Ipv6Option> ipv6Option;

  uint8_t processedSize = 0;
  uint32_t size = p->GetSize ();
  uint8_t *data = new uint8_t[size];
  p->CopyData (data, size);

  uint8_t optionType = 0;
  uint8_t optionLength = 0;

  while (length > processedSize && !isDropped)
    {
      optionType = *(data + processedSize);
      ipv6Option = ipv6OptionDemux->GetOption (optionType);

      if (ipv6Option == 0)
        {
          optionType >>= 6;
          switch (optionType)
            {
            case 0:
              optionLength = *(data + processedSize + 1) + 2;
              break;

            case 1:
              NS_LOG_LOGIC ("Unknown Option. Drop!");
              m_dropTrace (packet);
              optionLength = 0;
              isDropped = true;
              break;

            case 2:
              NS_LOG_LOGIC ("Unknown Option. Drop!");
              icmpv6->SendErrorParameterError (malformedPacket, ipv6Header.GetSourceAddress (), Icmpv6Header::ICMPV6_UNKNOWN_OPTION, offset + processedSize);
              m_dropTrace (packet);
              optionLength = 0;
              isDropped = true;
              break;

            case 3:
              NS_LOG_LOGIC ("Unknown Option. Drop!");

              if (!ipv6Header.GetDestinationAddress ().IsMulticast ())
                {
                  icmpv6->SendErrorParameterError (malformedPacket, ipv6Header.GetSourceAddress (), Icmpv6Header::ICMPV6_UNKNOWN_OPTION, offset + processedSize);
                  m_dropTrace (packet);
                  optionLength = 0;
                  isDropped = true;
                  break;
                }

              m_dropTrace (packet);
              optionLength = 0;
              isDropped = true;
              break;

            default:
              break;
            }

        }
      else
        {
          optionLength = ipv6Option->Process (packet, offset + processedSize, ipv6Header, isDropped);
        }

      processedSize += optionLength;
      p->RemoveAtStart (optionLength);
    }

  delete [] data;

  return processedSize;
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionHopByHop);

TypeId Ipv6ExtensionHopByHop::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionHopByHop")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionHopByHop> ()
  ;
  return tid;
}

Ipv6ExtensionHopByHop::Ipv6ExtensionHopByHop ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionHopByHop::~Ipv6ExtensionHopByHop ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionHopByHop::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionHopByHop::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  Ipv6ExtensionHopByHopHeader hopbyhopHeader;
  p->RemoveHeader (hopbyhopHeader);
  if (nextHeader)
    {
      *nextHeader = hopbyhopHeader.GetNextHeader ();
    }

  uint8_t processedSize = hopbyhopHeader.GetOptionsOffset ();
  offset += processedSize;
  uint8_t length = hopbyhopHeader.GetLength () - hopbyhopHeader.GetOptionsOffset ();

  processedSize += ProcessOptions (packet, offset, length, ipv6Header, dst, nextHeader, isDropped);

  return processedSize;
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionDestination);

TypeId Ipv6ExtensionDestination::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionDestination")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionDestination> ()
  ;
  return tid;
}

Ipv6ExtensionDestination::Ipv6ExtensionDestination ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionDestination::~Ipv6ExtensionDestination ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionDestination::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionDestination::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  Ipv6ExtensionDestinationHeader destinationHeader;
  p->RemoveHeader (destinationHeader);
  if (nextHeader)
    {
      *nextHeader = destinationHeader.GetNextHeader ();
    }

  uint8_t processedSize = destinationHeader.GetOptionsOffset ();
  offset += processedSize;
  uint8_t length = destinationHeader.GetLength () - destinationHeader.GetOptionsOffset ();

  processedSize += ProcessOptions (packet, offset, length, ipv6Header, dst, nextHeader, isDropped);

  return processedSize;
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionFragment);

TypeId Ipv6ExtensionFragment::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionFragment")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionFragment> ()
  ;
  return tid;
}

Ipv6ExtensionFragment::Ipv6ExtensionFragment ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionFragment::~Ipv6ExtensionFragment ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

void Ipv6ExtensionFragment::DoDispose ()
{
  NS_LOG_FUNCTION_NOARGS ();

  for (MapFragments_t::iterator it = m_fragments.begin (); it != m_fragments.end (); it++)
    {
      it->second = 0;
    }

  m_fragments.clear ();
  Ipv6Extension::DoDispose ();
}

uint8_t Ipv6ExtensionFragment::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionFragment::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  Ipv6ExtensionFragmentHeader fragmentHeader;
  p->RemoveHeader (fragmentHeader);

  if (nextHeader)
    {
      *nextHeader = fragmentHeader.GetNextHeader ();
    }

  bool moreFragment = fragmentHeader.GetMoreFragment ();
  uint16_t fragmentOffset = fragmentHeader.GetOffset ();
  uint32_t identification = fragmentHeader.GetIdentification ();
  Ipv6Address src = ipv6Header.GetSourceAddress ();

  std::pair<Ipv6Address, uint32_t> fragmentsId = std::make_pair<Ipv6Address, uint32_t> (src, identification);
  Ptr<Fragments> fragments;

  Ipv6Header ipHeader = ipv6Header;
  ipHeader.SetNextHeader (fragmentHeader.GetNextHeader ());

  MapFragments_t::iterator it = m_fragments.find (fragmentsId);
  if (it == m_fragments.end ())
    {
      fragments = Create<Fragments> ();
      m_fragments.insert (std::make_pair (fragmentsId, fragments));
      EventId timeout = Simulator::Schedule (Seconds (60),
                                             &Ipv6ExtensionFragment::HandleFragmentsTimeout, this,
                                             fragmentsId, ipHeader);
      fragments->SetTimeoutEventId (timeout);
    }
  else
    {
      fragments = it->second;
    }

  if (fragmentOffset == 0)
    {
      Ptr<Packet> unfragmentablePart = packet->Copy ();
      unfragmentablePart->RemoveAtEnd (packet->GetSize () - offset);
      fragments->SetUnfragmentablePart (unfragmentablePart);
    }

  fragments->AddFragment (p, fragmentOffset, moreFragment);

  if (fragments->IsEntire ())
    {
      packet = fragments->GetPacket ();
      fragments->CancelTimeout ();
      m_fragments.erase (fragmentsId);
      isDropped = false;
    }
  else
    {
      // the fragment is not "dropped", but Ipv6L3Protocol::LocalDeliver must stop processing it.
      isDropped = true;
    }

  return 0;
}

void Ipv6ExtensionFragment::GetFragments (Ptr<Packet> packet, uint32_t maxFragmentSize, std::list<Ptr<Packet> >& listFragments)
{
  Ptr<Packet> p = packet->Copy ();

  Ipv6Header ipv6Header;
  p->RemoveHeader (ipv6Header);

  uint8_t nextHeader = ipv6Header.GetNextHeader ();
  uint8_t ipv6HeaderSize = ipv6Header.GetSerializedSize ();

  uint8_t type;
  p->CopyData (&type, sizeof(type));

  bool moreHeader = true;
  if (!(nextHeader == Ipv6Header::IPV6_EXT_HOP_BY_HOP || nextHeader == Ipv6Header::IPV6_EXT_ROUTING
        || (nextHeader == Ipv6Header::IPV6_EXT_DESTINATION && type == Ipv6Header::IPV6_EXT_ROUTING)))
    {
      moreHeader = false;
      ipv6Header.SetNextHeader (Ipv6Header::IPV6_EXT_FRAGMENTATION);
    }

  std::list<std::pair<Ipv6ExtensionHeader *, uint8_t> > unfragmentablePart;
  uint32_t unfragmentablePartSize = 0;

  Ptr<Ipv6ExtensionDemux> extensionDemux = GetNode ()->GetObject<Ipv6ExtensionDemux> ();
  Ptr<Ipv6Extension> extension = extensionDemux->GetExtension (nextHeader);
  uint8_t extensionHeaderLength;

  while (moreHeader)
    {
      if (nextHeader == Ipv6Header::IPV6_EXT_HOP_BY_HOP)
        {
          Ipv6ExtensionHopByHopHeader *hopbyhopHeader = new Ipv6ExtensionHopByHopHeader ();
          p->RemoveHeader (*hopbyhopHeader);

          nextHeader = hopbyhopHeader->GetNextHeader ();
          extensionHeaderLength = hopbyhopHeader->GetLength ();

          uint8_t type;
          p->CopyData (&type, sizeof(type));

          if (!(nextHeader == Ipv6Header::IPV6_EXT_HOP_BY_HOP || nextHeader == Ipv6Header::IPV6_EXT_ROUTING
                || (nextHeader == Ipv6Header::IPV6_EXT_DESTINATION && type == Ipv6Header::IPV6_EXT_ROUTING)))
            {
              moreHeader = false;
              hopbyhopHeader->SetNextHeader (Ipv6Header::IPV6_EXT_FRAGMENTATION);
            }

          unfragmentablePart.push_back (std::make_pair<Ipv6ExtensionHeader *, uint8_t> (hopbyhopHeader, Ipv6Header::IPV6_EXT_HOP_BY_HOP));
          unfragmentablePartSize += extensionHeaderLength;
        }
      else if (nextHeader == Ipv6Header::IPV6_EXT_ROUTING)
        {
          uint8_t buf[2];
          p->CopyData (buf, sizeof(buf));
          uint8_t numberAddress = buf[1] / 2;
          Ipv6ExtensionLooseRoutingHeader *routingHeader = new Ipv6ExtensionLooseRoutingHeader ();
          routingHeader->SetNumberAddress (numberAddress);
          p->RemoveHeader (*routingHeader);

          nextHeader = routingHeader->GetNextHeader ();
          extensionHeaderLength = routingHeader->GetLength ();

          uint8_t type;
          p->CopyData (&type, sizeof(type));
          if (!(nextHeader == Ipv6Header::IPV6_EXT_HOP_BY_HOP || nextHeader == Ipv6Header::IPV6_EXT_ROUTING
                || (nextHeader == Ipv6Header::IPV6_EXT_DESTINATION && type == Ipv6Header::IPV6_EXT_ROUTING)))
            {
              moreHeader = false;
              routingHeader->SetNextHeader (Ipv6Header::IPV6_EXT_FRAGMENTATION);
            }

          unfragmentablePart.push_back (std::make_pair<Ipv6ExtensionHeader *, uint8_t> (routingHeader, Ipv6Header::IPV6_EXT_ROUTING));
          unfragmentablePartSize += extensionHeaderLength;
        }
      else if (nextHeader == Ipv6Header::IPV6_EXT_DESTINATION)
        {
          Ipv6ExtensionDestinationHeader *destinationHeader = new Ipv6ExtensionDestinationHeader ();
          p->RemoveHeader (*destinationHeader);

          nextHeader = destinationHeader->GetNextHeader ();
          extensionHeaderLength = destinationHeader->GetLength ();

          uint8_t type;
          p->CopyData (&type, sizeof(type));
          if (!(nextHeader == Ipv6Header::IPV6_EXT_HOP_BY_HOP || nextHeader == Ipv6Header::IPV6_EXT_ROUTING
                || (nextHeader == Ipv6Header::IPV6_EXT_DESTINATION && type == Ipv6Header::IPV6_EXT_ROUTING)))
            {
              moreHeader = false;
              destinationHeader->SetNextHeader (Ipv6Header::IPV6_EXT_FRAGMENTATION);
            }

          unfragmentablePart.push_back (std::make_pair<Ipv6ExtensionHeader *, uint8_t> (destinationHeader, Ipv6Header::IPV6_EXT_DESTINATION));
          unfragmentablePartSize += extensionHeaderLength;
        }
    }

  Ipv6ExtensionFragmentHeader fragmentHeader;
  uint8_t fragmentHeaderSize = fragmentHeader.GetSerializedSize ();

  uint32_t maxFragmentablePartSize = maxFragmentSize - ipv6HeaderSize - unfragmentablePartSize - fragmentHeaderSize;
  uint32_t currentFragmentablePartSize = 0;

  bool moreFragment = true;
  UniformVariable uvar;
  uint32_t identification = (uint32_t) uvar.GetValue (0, (uint32_t)-1);
  uint16_t offset = 0;

  do
    {
      if (p->GetSize () > offset + maxFragmentablePartSize)
        {
          moreFragment = true;
          currentFragmentablePartSize = maxFragmentablePartSize;
        }
      else
        {
          moreFragment = false;
          currentFragmentablePartSize = p->GetSize () - offset;
        }

      currentFragmentablePartSize -= currentFragmentablePartSize % 8;

      fragmentHeader.SetNextHeader (nextHeader);
      fragmentHeader.SetLength (currentFragmentablePartSize);
      fragmentHeader.SetOffset (offset);
      fragmentHeader.SetMoreFragment (moreFragment);
      fragmentHeader.SetIdentification (identification);

      Ptr<Packet> fragment = p->CreateFragment (offset, currentFragmentablePartSize);
      offset += currentFragmentablePartSize;

      fragment->AddHeader (fragmentHeader);

      for (std::list<std::pair<Ipv6ExtensionHeader *, uint8_t> >::iterator it = unfragmentablePart.begin (); it != unfragmentablePart.end (); it++)
        {
          if (it->second == Ipv6Header::IPV6_EXT_HOP_BY_HOP)
            {
              fragment->AddHeader (*dynamic_cast<Ipv6ExtensionHopByHopHeader *> (it->first));
            }
          else if (it->second == Ipv6Header::IPV6_EXT_ROUTING)
            {
              fragment->AddHeader (*dynamic_cast<Ipv6ExtensionLooseRoutingHeader *> (it->first));
            }
          else if (it->second == Ipv6Header::IPV6_EXT_DESTINATION)
            {
              fragment->AddHeader (*dynamic_cast<Ipv6ExtensionDestinationHeader *> (it->first));
            }
        }

      ipv6Header.SetPayloadLength (fragment->GetSize ());
      fragment->AddHeader (ipv6Header);

      std::ostringstream oss;
      fragment->Print (oss);
      listFragments.push_back (fragment);
    }
  while (moreFragment);

  for (std::list<std::pair<Ipv6ExtensionHeader *, uint8_t> >::iterator it = unfragmentablePart.begin (); it != unfragmentablePart.end (); it++)
    {
      delete it->first;
    }

  unfragmentablePart.clear ();
}


void Ipv6ExtensionFragment::HandleFragmentsTimeout (std::pair<Ipv6Address, uint32_t> fragmentsId,
                                                    Ipv6Header & ipHeader)
{
  Ptr<Fragments> fragments;

  MapFragments_t::iterator it = m_fragments.find (fragmentsId);
  NS_ASSERT_MSG(it != m_fragments.end (), "IPv6 Fragment timeout reached for non-existent fragment");
  fragments = it->second;

  Ptr<Packet> packet = fragments->GetPartialPacket ();

  packet->AddHeader (ipHeader);

  // if we have at least 8 bytes, we can send an ICMP.
  if ( packet->GetSize () > 8 )
    {
      Ptr<Icmpv6L4Protocol> icmp = GetNode ()->GetObject<Icmpv6L4Protocol> ();
      icmp->SendErrorTimeExceeded (packet, ipHeader.GetSourceAddress (), Icmpv6Header::ICMPV6_FRAGTIME);
    }
  m_dropTrace (packet);

  // clear the buffers
  m_fragments.erase (fragmentsId);
}

Ipv6ExtensionFragment::Fragments::Fragments ()
  : m_moreFragment (0)
{
}

Ipv6ExtensionFragment::Fragments::~Fragments ()
{
}

void Ipv6ExtensionFragment::Fragments::AddFragment (Ptr<Packet> fragment, uint16_t fragmentOffset, bool moreFragment)
{
  std::list<std::pair<Ptr<Packet>, uint16_t> >::iterator it;

  for (it = m_packetFragments.begin (); it != m_packetFragments.end (); it++)
    {
      if (it->second > fragmentOffset)
        {
          break;
        }
    }

  if (it == m_packetFragments.end ())
    {
      m_moreFragment = moreFragment;
    }

  m_packetFragments.insert (it, std::make_pair<Ptr<Packet>, uint16_t> (fragment, fragmentOffset));
}

void Ipv6ExtensionFragment::Fragments::SetUnfragmentablePart (Ptr<Packet> unfragmentablePart)
{
  m_unfragmentable = unfragmentablePart;
}

bool Ipv6ExtensionFragment::Fragments::IsEntire () const
{
  bool ret = !m_moreFragment && m_packetFragments.size () > 0;

  if (ret)
    {
      uint16_t lastEndOffset = 0;

      for (std::list<std::pair<Ptr<Packet>, uint16_t> >::const_iterator it = m_packetFragments.begin (); it != m_packetFragments.end (); it++)
        {
          if (lastEndOffset != it->second)
            {
              ret = false;
              break;
            }

          lastEndOffset += it->first->GetSize ();
        }
    }

  return ret;
}

Ptr<Packet> Ipv6ExtensionFragment::Fragments::GetPacket () const
{
  Ptr<Packet> p =  m_unfragmentable->Copy ();

  for (std::list<std::pair<Ptr<Packet>, uint16_t> >::const_iterator it = m_packetFragments.begin (); it != m_packetFragments.end (); it++)
    {
      p->AddAtEnd (it->first);
    }

  return p;
}

Ptr<Packet> Ipv6ExtensionFragment::Fragments::GetPartialPacket () const
{
  Ptr<Packet> p;

  if ( m_unfragmentable )
    {
      p = m_unfragmentable->Copy ();
    }
  else
    {
      return p;
    }

  uint16_t lastEndOffset = 0;

  for (std::list<std::pair<Ptr<Packet>, uint16_t> >::const_iterator it = m_packetFragments.begin (); it != m_packetFragments.end (); it++)
    {
      if (lastEndOffset != it->second)
        {
          break;
        }
      p->AddAtEnd (it->first);
      lastEndOffset += it->first->GetSize ();
    }

  return p;
}

void Ipv6ExtensionFragment::Fragments::SetTimeoutEventId (EventId event)
{
  m_timeoutEventId = event;
  return;
}

void Ipv6ExtensionFragment::Fragments::CancelTimeout ()
{
  m_timeoutEventId.Cancel ();
  return;
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionRouting);

TypeId Ipv6ExtensionRouting::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionRouting")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionRouting> ()
  ;
  return tid;
}

Ipv6ExtensionRouting::Ipv6ExtensionRouting ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionRouting::~Ipv6ExtensionRouting ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionRouting::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionRouting::GetTypeRouting () const
{
  NS_LOG_FUNCTION_NOARGS ();
  return 0;
}

uint8_t Ipv6ExtensionRouting::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  // For ICMPv6 Error Packets
  Ptr<Packet> malformedPacket = packet->Copy ();
  malformedPacket->AddHeader (ipv6Header);

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  uint8_t buf[4];
  packet->CopyData (buf, sizeof(buf));

  uint8_t routingNextHeader = buf[0];
  uint8_t routingLength = buf[1];
  uint8_t routingTypeRouting = buf[2];
  uint8_t routingSegmentsLeft = buf[3];

  if (nextHeader)
    {
      *nextHeader = routingNextHeader;
    }

  Ptr<Icmpv6L4Protocol> icmpv6 = GetNode ()->GetObject<Ipv6L3Protocol> ()->GetIcmpv6 ();

  Ptr<Ipv6ExtensionRoutingDemux> ipv6ExtensionRoutingDemux = GetNode ()->GetObject<Ipv6ExtensionRoutingDemux> ();
  Ptr<Ipv6ExtensionRouting> ipv6ExtensionRouting = ipv6ExtensionRoutingDemux->GetExtensionRouting (routingTypeRouting);

  if (ipv6ExtensionRouting == 0)
    {
      if (routingSegmentsLeft == 0)
        {
          isDropped = false;
        }
      else
        {
          NS_LOG_LOGIC ("Malformed header. Drop!");

          icmpv6->SendErrorParameterError (malformedPacket, ipv6Header.GetSourceAddress (), Icmpv6Header::ICMPV6_MALFORMED_HEADER, offset + 1);
          m_dropTrace (packet);
          isDropped = true;
        }

      return routingLength;
    }

  return ipv6ExtensionRouting->Process (packet, offset, ipv6Header, dst, (uint8_t *)0, isDropped);
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionRoutingDemux);

TypeId Ipv6ExtensionRoutingDemux::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionRoutingDemux")
    .SetParent<Object> ()
    .AddAttribute ("Routing Extensions", "The set of IPv6 Routing extensions registered with this demux.",
                   ObjectVectorValue (),
                   MakeObjectVectorAccessor (&Ipv6ExtensionRoutingDemux::m_extensionsRouting),
                   MakeObjectVectorChecker<Ipv6ExtensionRouting> ())
  ;
  return tid;
}

Ipv6ExtensionRoutingDemux::Ipv6ExtensionRoutingDemux ()
{
}

Ipv6ExtensionRoutingDemux::~Ipv6ExtensionRoutingDemux ()
{
}

void Ipv6ExtensionRoutingDemux::DoDispose ()
{
  for (Ipv6ExtensionRoutingList_t::iterator it = m_extensionsRouting.begin (); it != m_extensionsRouting.end (); it++)
    {
      (*it)->Dispose ();
      *it = 0;
    }
  m_extensionsRouting.clear ();
  m_node = 0;
  Object::DoDispose ();
}

void Ipv6ExtensionRoutingDemux::SetNode (Ptr<Node> node)
{
  m_node = node;
}

void Ipv6ExtensionRoutingDemux::Insert (Ptr<Ipv6ExtensionRouting> extensionRouting)
{
  m_extensionsRouting.push_back (extensionRouting);
}

Ptr<Ipv6ExtensionRouting> Ipv6ExtensionRoutingDemux::GetExtensionRouting (uint8_t typeRouting)
{
  for (Ipv6ExtensionRoutingList_t::iterator i = m_extensionsRouting.begin (); i != m_extensionsRouting.end (); i++)
    {
      if ((*i)->GetTypeRouting () == typeRouting)
        {
          return *i;
        }
    }
  return 0;
}

void Ipv6ExtensionRoutingDemux::Remove (Ptr<Ipv6ExtensionRouting> extensionRouting)
{
  m_extensionsRouting.remove (extensionRouting);
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionLooseRouting);

TypeId Ipv6ExtensionLooseRouting::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionLooseRouting")
    .SetParent<Ipv6ExtensionRouting> ()
    .AddConstructor<Ipv6ExtensionLooseRouting> ()
  ;
  return tid;
}

Ipv6ExtensionLooseRouting::Ipv6ExtensionLooseRouting ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionLooseRouting::~Ipv6ExtensionLooseRouting ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionLooseRouting::GetTypeRouting () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return TYPE_ROUTING;
}

uint8_t Ipv6ExtensionLooseRouting::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  // For ICMPv6 Error packets
  Ptr<Packet> malformedPacket = packet->Copy ();
  malformedPacket->AddHeader (ipv6Header);

  Ptr<Packet> p = packet->Copy ();
  p->RemoveAtStart (offset);

  // Copy IPv6 Header : ipv6Header -> ipv6header
  Buffer tmp;
  tmp.AddAtStart (ipv6Header.GetSerializedSize ());
  Buffer::Iterator it = tmp.Begin ();
  Ipv6Header ipv6header;
  ipv6Header.Serialize (it);
  ipv6header.Deserialize (it);

  // Get the number of routers' address field
  uint8_t buf[2];
  p->CopyData (buf, sizeof(buf));
  uint8_t numberAddress = buf[1] / 2;
  Ipv6ExtensionLooseRoutingHeader routingHeader;
  routingHeader.SetNumberAddress (numberAddress);
  p->RemoveHeader (routingHeader);

  if (nextHeader)
    {
      *nextHeader = routingHeader.GetNextHeader ();
    }

  Ptr<Icmpv6L4Protocol> icmpv6 = GetNode ()->GetObject<Ipv6L3Protocol> ()->GetIcmpv6 ();

  Ipv6Address srcAddress = ipv6header.GetSourceAddress ();
  Ipv6Address destAddress = ipv6header.GetDestinationAddress ();
  uint8_t hopLimit = ipv6header.GetHopLimit ();
  uint8_t segmentsLeft = routingHeader.GetSegmentsLeft ();
  uint8_t length = (routingHeader.GetLength () >> 3) - 1;
  uint8_t nbAddress = length / 2;
  uint8_t nextAddressIndex;
  Ipv6Address nextAddress;

  if (segmentsLeft == 0)
    {
      isDropped = false;
      return routingHeader.GetSerializedSize ();
    }

  if (length % 2 != 0)
    {
      NS_LOG_LOGIC ("Malformed header. Drop!");
      icmpv6->SendErrorParameterError (malformedPacket, srcAddress, Icmpv6Header::ICMPV6_MALFORMED_HEADER, offset + 1);
      m_dropTrace (packet);
      isDropped = true;
      return routingHeader.GetSerializedSize ();
    }

  if (segmentsLeft > nbAddress)
    {
      NS_LOG_LOGIC ("Malformed header. Drop!");
      icmpv6->SendErrorParameterError (malformedPacket, srcAddress, Icmpv6Header::ICMPV6_MALFORMED_HEADER, offset + 3);
      m_dropTrace (packet);
      isDropped = true;
      return routingHeader.GetSerializedSize ();
    }

  routingHeader.SetSegmentsLeft (segmentsLeft - 1);
  nextAddressIndex = nbAddress - segmentsLeft;
  nextAddress = routingHeader.GetRouterAddress (nextAddressIndex);

  if (nextAddress.IsMulticast () || destAddress.IsMulticast ())
    {
      m_dropTrace (packet);
      isDropped = true;
      return routingHeader.GetSerializedSize ();
    }

  routingHeader.SetRouterAddress (nextAddressIndex, destAddress);
  ipv6header.SetDestinationAddress (nextAddress);

  if (hopLimit <= 1)
    {
      NS_LOG_LOGIC ("Time Exceeded : Hop Limit <= 1. Drop!");
      icmpv6->SendErrorTimeExceeded (malformedPacket, srcAddress, Icmpv6Header::ICMPV6_HOPLIMIT);
      m_dropTrace (packet);
      isDropped = true;
      return routingHeader.GetSerializedSize ();
    }

  routingHeader.SetLength (88);
  ipv6header.SetHopLimit (hopLimit - 1);
  p->AddHeader (routingHeader);

  /* short-circuiting routing stuff
   *
   * If we process this option,
   * the packet was for us so we resend it to
   * the new destination (modified in the header above).
   */

  Ptr<Ipv6L3Protocol> ipv6 = GetNode ()->GetObject<Ipv6L3Protocol> ();
  Ptr<Ipv6RoutingProtocol> ipv6rp = ipv6->GetRoutingProtocol ();
  Socket::SocketErrno err;
  NS_ASSERT (ipv6rp);

  Ptr<Ipv6Route> rtentry = ipv6rp->RouteOutput (p, ipv6header, 0, err);

  if (rtentry)
    {
      /* we know a route exists so send packet now */
      ipv6->SendRealOut (rtentry, p, ipv6header);
    }
  else
    {
      NS_LOG_INFO ("No route for next router");
    }

  /* as we directly send packet, mark it as dropped */
  isDropped = true;

  return routingHeader.GetSerializedSize ();
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionESP);

TypeId Ipv6ExtensionESP::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionESP")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionESP> ()
  ;
  return tid;
}

Ipv6ExtensionESP::Ipv6ExtensionESP ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionESP::~Ipv6ExtensionESP ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionESP::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionESP::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  /* TODO */

  return 0;
}


NS_OBJECT_ENSURE_REGISTERED (Ipv6ExtensionAH);

TypeId Ipv6ExtensionAH::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::Ipv6ExtensionAH")
    .SetParent<Ipv6Extension> ()
    .AddConstructor<Ipv6ExtensionAH> ()
  ;
  return tid;
}

Ipv6ExtensionAH::Ipv6ExtensionAH ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6ExtensionAH::~Ipv6ExtensionAH ()
{
  NS_LOG_FUNCTION_NOARGS ();
}

uint8_t Ipv6ExtensionAH::GetExtensionNumber () const
{
  NS_LOG_FUNCTION_NOARGS ();

  return EXT_NUMBER;
}

uint8_t Ipv6ExtensionAH::Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped)
{
  NS_LOG_FUNCTION (this << packet << offset << ipv6Header << dst << nextHeader << isDropped);

  /* TODO */

  return true;
}

} /* namespace ns3 */

