/* -*-  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/ipv6-address.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 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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped) = 0;

  protected:
    TracedCallback<Ptr<const Packet> > m_dropTrace;

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

/**
 * \class Ipv6ExtensionHopByHop
 * \brief IPv6 Extension "Hop By Hop"
 */
class Ipv6ExtensionHopByHop : public Ipv6Extension
{
  public:
    static const uint8_t EXT_NUMBER;

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

/**
 * \class Ipv6ExtensionDestination
 * \brief IPv6 Extension Destination
 */
class Ipv6ExtensionDestination : public Ipv6Extension
{
  public:
    static const uint8_t EXT_NUMBER;

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

/**
 * \class Ipv6ExtensionFragment
 * \brief IPv6 Extension Fragment
 */
class Ipv6ExtensionFragment : public Ipv6Extension
{
  public:
    static const uint8_t EXT_NUMBER;

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);

    /**
     * \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:
        /**
         * \brief Constructor.
         */
        Fragments ();

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

        void Ref () const;
        void Unref () const;

        /**
         * \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;

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

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

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

        /**
         * \brief Number of references.
         */
        mutable uint32_t m_refCount;
    };

    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:
    static const uint8_t EXT_NUMBER;

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

/**
 * \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:
    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:
    static const uint8_t TYPE_ROUTING;

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

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

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

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

    /**
     * \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;

    /**
     * \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 isDropped if the packet must be dropped
     * \return the size processed
     */
    virtual uint8_t Process (Ptr<Packet>& packet, uint8_t offset, Ipv6Header const& ipv6Header, Ipv6Address dst, uint8_t *nextHeader, bool& isDropped);
};

} /* namespace ns3 */

#endif /* IPV6_EXTENSION_H */