/* -*- 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>
 */

#ifndef IPV6_EXTENSION_H
#define IPV6_EXTENSION_H

#include <map>
#include <list>

#include "ns3/object.h"
#include "ns3/node.h"
#include "ns3/ptr.h"
#include "ipv6-interface.h"
#include "ns3/ipv6-header.h"
#include "ns3/buffer.h"
#include "ns3/packet.h"
#include "ns3/random-variable-stream.h"
#include "ns3/ipv6-address.h"
#include "ns3/ipv6-l3-protocol.h"
#include "ns3/traced-callback.h"


namespace ns3 {

/**
 * \class Ipv6Extension
 * \brief IPv6 Extension base
 * If you want to implement a new IPv6 extension, all you have to do is
 * implement a subclass of this class and add it to an Ipv6ExtensionDemux.
 */
class Ipv6Extension : public Object
{
public:
  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6Extension ();

  /**
   * \brief Destructor.
   */
  virtual ~Ipv6Extension ();

  /**
   * \brief Set the node.
   * \param node the node to set
   */
  void SetNode (Ptr<Node> node);

  /**
   * \brief Get the node.
   * \return the node
   */
  Ptr<Node> GetNode () const;

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const = 0;

  /**
   * \brief Process method
   * Called from Ipv6L3Protocol::Receive.
   *
   * \param packet the packet
   * \param offset the offset of the extension to process
   * \param ipv6Header the IPv6 header of packet received
   * \param dst destination address of the packet received (i.e. us)
   * \param nextHeader the next header
   * \param stopProcessing true if the packet must not be further processed
   * \param isDropped true if the packet must be dropped
   * \param dropReason dropping reason
   * \return the size processed
   */
  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason) = 0;

  /**
   * \brief Process options
   * Called by implementing classes to process the options
   *
   * \param packet the packet
   * \param offset the offset of the first option to process
   * \param length the total length of all options (as specified in the extension header)
   * \param ipv6Header the IPv6 header of packet received
   * \param dst destination address of the packet received (i.e. us)
   * \param nextHeader the next header
   * \param stopProcessing true if the packet must not be further processed
   * \param isDropped true if the packet must be dropped
   * \param dropReason dropping reason
   * \return the size processed
   */
  virtual uint8_t ProcessOptions (Ptr<Packet>& packet,
                                  uint8_t offset,
                                  uint8_t length,
                                  Ipv6Header const& ipv6Header,
                                  Ipv6Address dst,
                                  uint8_t *nextHeader,
                                  bool& stopProcessing,
                                  bool& isDropped,
                                  Ipv6L3Protocol::DropReason& dropReason
                                  );

 /**
  * Assign a fixed random variable stream number to the random variables
  * used by this model.  Return the number of streams (possibly zero) that
  * have been assigned.
  *
  * \param stream first stream index to use
  * \return the number of stream indices assigned by this model
  */
  int64_t AssignStreams (int64_t stream);

protected:
  /**
   * \brief Provides uniform random variables.
   */
  Ptr<UniformRandomVariable> m_uvar;

private:
  /**
   * \brief The node.
   */
  Ptr<Node> m_node;
};

/**
 * \class Ipv6ExtensionHopByHop
 * \brief IPv6 Extension "Hop By Hop"
 */
class Ipv6ExtensionHopByHop : public Ipv6Extension
{
public:
  /**
   * \brief Hop-by-hop extension number.
   */
  static const uint8_t EXT_NUMBER = 0;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionHopByHop ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionHopByHop ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

/**
 * \class Ipv6ExtensionDestination
 * \brief IPv6 Extension Destination
 */
class Ipv6ExtensionDestination : public Ipv6Extension
{
public:
  /**
   * \brief Destination extension number.
   */
  static const uint8_t EXT_NUMBER = 60;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionDestination ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionDestination ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

/**
 * \class Ipv6ExtensionFragment
 * \brief IPv6 Extension Fragment
 */
class Ipv6ExtensionFragment : public Ipv6Extension
{
public:
  /**
   * \brief Fragmentation extension number.
   */
  static const uint8_t EXT_NUMBER = 44;

  /**
    * \brief Get the type identificator.
    * \return type identificator
    */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionFragment ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionFragment ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);

  /**
   * \brief Fragment a packet
   * \param packet the packet
   * \param fragmentSize the maximal size of the fragment (unfragmentable part + fragmentation header + fragmentable part)
   * \param listFragments the list of fragments
   */
  void GetFragments (Ptr<Packet> packet, uint32_t fragmentSize, std::list<Ptr<Packet> >& listFragments);

protected:
  /**
   * \brief Dispose this object.
   */
  virtual void DoDispose ();

private:
  /**
   * \class Fragments
   * \brief A Set of Fragment
   */
  class Fragments : public SimpleRefCount<Fragments>
  {
public:
    /**
     * \brief Constructor.
     */
    Fragments ();

    /**
     * \brief Destructor.
     */
    ~Fragments ();

    /**
     * \brief Add a fragment.
     * \param fragment the fragment
     * \param fragmentOffset the offset of the fragment
     * \param moreFragment the bit "More Fragment"
     */
    void AddFragment (Ptr<Packet> fragment, uint16_t fragmentOffset, bool moreFragment);

    /**
     * \brief Set the unfragmentable part of the packet.
     * \param unfragmentablePart the unfragmentable part
     */
    void SetUnfragmentablePart (Ptr<Packet> unfragmentablePart);

    /**
     * \brief If all fragments have been added.
     * \returns true if the packet is entire
     */
    bool IsEntire () const;

    /**
     * \brief Get the entire packet.
     * \return the entire packet
     */
    Ptr<Packet> GetPacket () const;

    /**
     * \brief Get the packet parts so far received.
     * \return the partial packet
     */
    Ptr<Packet> GetPartialPacket () const;

    /**
     * \brief Set the Timeout EventId.
     */
    void SetTimeoutEventId (EventId event);

    /**
     * \brief Cancel the timeout event
     */
    void CancelTimeout ();

private:
    /**
     * \brief If other fragments will be sent.
     */
    bool m_moreFragment;

    /**
     * \brief The current fragments.
     */
    std::list<std::pair<Ptr<Packet>, uint16_t> > m_packetFragments;

    /**
     * \brief The unfragmentable part.
     */
    Ptr<Packet> m_unfragmentable;

    /**
     * \brief Timeout handler event
     */
    EventId m_timeoutEventId;
  };

  /**
   * \brief Process the timeout for packet fragments
   * \param key representing the packet fragments
   * \param ipHeader the IP header of the original packet
   */
  void HandleFragmentsTimeout (std::pair<Ipv6Address, uint32_t> key, Ipv6Header ipHeader);

  /**
   * \brief Get the packet parts so far received.
   * \return the partial packet
   */
  Ptr<Packet> GetPartialPacket () const;

  /**
   * \brief Set the Timeout EventId.
   */
  void SetTimeoutEventId (EventId event);

  /**
   * \brief Cancel the timeout event
   */
  void CancelTimeout ();

  /**
   * \brief Container for the packet fragments.
   */
  typedef std::map<std::pair<Ipv6Address, uint32_t>, Ptr<Fragments> > MapFragments_t;

  /**
   * \brief The hash of fragmented packets.
   */
  MapFragments_t m_fragments;
};

/**
 * \class Ipv6ExtensionRouting
 * \brief IPv6 Extension Routing
 * If you want to implement a new IPv6 routing extension, all you have to do is
 * implement a subclass of this class and add it to an Ipv6ExtensionRoutingDemux.
 */
class Ipv6ExtensionRouting : public Ipv6Extension
{
public:
  /**
   * \brief Routing extension number.
   */
  static const uint8_t EXT_NUMBER = 43;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionRouting ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionRouting ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  /**
   * \brief Get the type of routing.
   * \return type of routing
   */
  virtual uint8_t GetTypeRouting () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

/**
 * \class Ipv6ExtensionRoutingDemux
 * \brief IPv6 Extension Routing Demux.
 */
class Ipv6ExtensionRoutingDemux : public Object
{
public:
  /**
   * \brief The interface ID.
   * \return type ID
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionRoutingDemux ();

  /**
   * \brief Destructor.
   */
  virtual ~Ipv6ExtensionRoutingDemux ();

  /**
   * \brief Set the node.
   * \param node the node to set
   */
  void SetNode (Ptr<Node> node);

  /**
   * \brief Insert a new IPv6 Routing Extension.
   * \param extensionRouting the routing extension to insert
   */
  void Insert (Ptr<Ipv6ExtensionRouting> extensionRouting);

  /**
   * \brief Get the routing extension corresponding to typeRouting.
   * \param typeRouting the number of the routing extension to retrieve
   * \return a matching IPv6 routing extension
   */
  Ptr<Ipv6ExtensionRouting> GetExtensionRouting (uint8_t typeRouting);

  /**
   * \brief Remove a routing extension from this demux.
   * \param extensionRouting pointer on the extension to remove
   */
  void Remove (Ptr<Ipv6ExtensionRouting> extensionRouting);

protected:
  /**
   * \brief Dispose this object.
   */
  virtual void DoDispose ();

private:
  /**
   * \brief Container for the extension routing.
   */
  typedef std::list<Ptr<Ipv6ExtensionRouting> > Ipv6ExtensionRoutingList_t;

  /**
   * \brief List of IPv6 Routing Extensions supported.
   */
  Ipv6ExtensionRoutingList_t m_extensionsRouting;

  /**
   * \brief The node.
   */
  Ptr<Node> m_node;
};

/**
 * \class Ipv6ExtensionLooseRouting
 * \brief IPv6 Extension Loose Routing
 */
class Ipv6ExtensionLooseRouting : public Ipv6ExtensionRouting
{
public:
  /**
   * \brief Routing type.
   */
  static const uint8_t TYPE_ROUTING = 0;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionLooseRouting ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionLooseRouting ();

  /**
   * \brief Get the type of routing.
   * \return type of routing
   */
  virtual uint8_t GetTypeRouting () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

/**
 * \class Ipv6ExtensionESP
 * \brief IPv6 Extension ESP (Encapsulating Security Payload)
 */
class Ipv6ExtensionESP : public Ipv6Extension
{
public:
  /**
   * \brief ESP extension number.
   */
  static const uint8_t EXT_NUMBER = 50;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionESP ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionESP ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

/**
 * \class Ipv6ExtensionAH
 * \brief IPv6 Extension AH (Authentication Header)
 */
class Ipv6ExtensionAH : public Ipv6Extension
{
public:
  /**
   * \brief AH extension number.
   */
  static const uint8_t EXT_NUMBER = 51;

  /**
   * \brief Get the type identificator.
   * \return type identificator
   */
  static TypeId GetTypeId ();

  /**
   * \brief Constructor.
   */
  Ipv6ExtensionAH ();

  /**
   * \brief Destructor.
   */
  ~Ipv6ExtensionAH ();

  /**
   * \brief Get the extension number.
   * \return extension number
   */
  virtual uint8_t GetExtensionNumber () const;

  virtual uint8_t Process (Ptr<Packet>& packet,
                           uint8_t offset,
                           Ipv6Header const& ipv6Header,
                           Ipv6Address dst,
                           uint8_t *nextHeader,
                           bool& stopProcessing,
                           bool& isDropped,
                           Ipv6L3Protocol::DropReason& dropReason);
};

} /* namespace ns3 */

#endif /* IPV6_EXTENSION_H */

