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

/*

 * Copyright (c) 2013 Universita' di Firenze, Italy

 *

 * 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: Tommaso Pecorella <tommaso.pecorella@unifi.it>

 *         Michele Muccio <michelemuccio@virgilio.it>

 */

#ifndef SIXLOWPAN_NET_DEVICE_H

#define SIXLOWPAN_NET_DEVICE_H

#include <stdint.h>

#include <string>

#include <map>

#include "ns3/traced-callback.h"

#include "ns3/event-id.h"

#include "ns3/nstime.h"

#include "ns3/net-device.h"

#include "ns3/packet.h"

#include "sixlowpan-header.h"

#include "ns3/random-variable-stream.h"

namespace ns3 {

class Node;

/**

 * \defgroup sixlowpan 6LoWPAN

 *

 * This module acts as a shim between IPv6 and a generic NetDevice.

 *

 * <ul>

 * <li> MESH and LOWPAN_BC0 dispatch types are not supported </li>

 * <li> HC2 encoding is not supported </li>

 * <li> IPHC's SAC and DAC are not supported </li>

 *</ul>

 */

/**

 * \ingroup sixlowpan

 *

 * \brief Shim performing 6LoWPAN compression, decompression and fragmentation.

 *

 * This class implements the shim between IPv6 and a generic NetDevice,

 * performing packet compression, decompression and fragmentation in a transparent way.

 * To this end, the class pretend to be a normal NetDevice, masquerading some functions

 * of the underlying NetDevice.

 */

class SixLowPanNetDevice : public NetDevice

{

public:

  /**

   * Enumeration of the dropping reasons in SixLoWPAN.

   */

  enum DropReason

  {

    DROP_FRAGMENT_TIMEOUT = 1, /**< Fragment timeout exceeded */

    DROP_FRAGMENT_BUFFER_FULL, /**< Fragment buffer size exceeded */

    DROP_UNKNOWN_EXTENSION /**< Unsupported compression kind */

  };

  /**

   * \brief Get the type ID.

   */

  static TypeId GetTypeId (void);

  /**

   * Constructor for the SixLowPanNetDevice.

   */

  SixLowPanNetDevice ();

  // inherited from NetDevice base class

  virtual void SetIfIndex (const uint32_t index);

  virtual uint32_t GetIfIndex (void) const;

  virtual Ptr<Channel> GetChannel (void) const;

  virtual void SetAddress (Address address);

  virtual Address GetAddress (void) const;

  virtual bool SetMtu (const uint16_t mtu);

  /**

   * \brief Returns the link-layer MTU for this interface.

   * 1280 will be returned.

   *

   */

  virtual uint16_t GetMtu (void) const;

  virtual bool IsLinkUp (void) const;

  virtual void AddLinkChangeCallback (Callback<void> callback);

  virtual bool IsBroadcast (void) const;

  virtual Address GetBroadcast (void) const;

  virtual bool IsMulticast (void) const;

  virtual Address GetMulticast (Ipv4Address multicastGroup) const;

  virtual bool IsPointToPoint (void) const;

  virtual bool IsBridge (void) const;

  virtual bool Send (Ptr<Packet> packet, const Address& dest, uint16_t protocolNumber);

  virtual bool SendFrom (Ptr<Packet> packet, const Address& source, const Address& dest, uint16_t protocolNumber);

  virtual Ptr<Node> GetNode (void) const;

  virtual void SetNode (Ptr<Node> node);

  virtual bool NeedsArp (void) const;

  virtual void SetReceiveCallback (NetDevice::ReceiveCallback cb);

  virtual void SetPromiscReceiveCallback (NetDevice::PromiscReceiveCallback cb);

  virtual bool SupportsSendFrom () const;

  virtual Address GetMulticast (Ipv6Address addr) const;

  /**

   * \brief Returns a smart pointer to the underlying NetDevice.

   *

   */

  Ptr<NetDevice> GetNetDevice () const;

  /**

   * \brief Setup SixLowPan to be a proxy for the specified NetDevice.

   * All the packets incoming and outgoing from the NetDevice will be

   * processed by SixLowPanNetDevice.

   *

   */

  void SetNetDevice (Ptr<NetDevice> device);

  /**

   * 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.

   *

   */

  int64_t AssignStreams (int64_t stream);

  /**

   * TracedCallback signature for packet send/receive events.

   *

   * \param [in] packet The packet.

   * \param [in] ifindex The ifindex of the device.

   */

  typedef void (* RxTxTracedCallback)

    (const Ptr<const Packet> packet,

     const Ptr<const SixLowPanNetDevice> sixNetDevice,

     const uint32_t ifindex);

  /**

   * TracedCallback signature for

   *

   * \param [in] reason The reason for the drop.

   * \param [in] packet The packet.

   * \param [in] ifindex The ifindex of the device.

   */

  typedef void (* DropTracedCallback)

    (const DropReason reason, const Ptr<const Packet> packet,

     const Ptr<const SixLowPanNetDevice> sixNetDevice,

     const uint32_t ifindex);

protected:

  virtual void DoDispose (void);

private:

  /**

   * \brief Copy constructor

   *

   */

  SixLowPanNetDevice (SixLowPanNetDevice const &);

  /**

   * \brief Copy constructor

   *

   * \returns

   */

  SixLowPanNetDevice& operator= (SixLowPanNetDevice const &);

  /**

   */

  void ReceiveFromDevice (Ptr<NetDevice> device, Ptr<const Packet> packet, uint16_t protocol,

                          Address const &source, Address const &destination, PacketType packetType);

  /**

   *        this packet. Used to call the right L3Protocol when the packet

   *        is received.

   *

   *  Called from higher layer to send packet into Network Device

   *  with the specified source and destination Addresses.

   *

   */

  bool DoSend (Ptr<Packet> packet, const Address& source, const Address& dest, uint16_t protocolNumber, bool doSendFrom);

  /**

   * The callback used to notify higher layers that a packet has been received.

   */

  NetDevice::ReceiveCallback m_rxCallback;

  /**

   * The callback used to notify higher layers that a packet has been received in promiscuous mode.

   */

  NetDevice::PromiscReceiveCallback m_promiscRxCallback;

  /**

   * \brief Callback to trace TX (transmission) packets.

   *

   * Data passed:

   * \li Packet received (including 6LoWPAN header)

   * \li Ptr to SixLowPanNetDevice

   * \li interface index

   */

  TracedCallback<Ptr<const Packet>, Ptr<SixLowPanNetDevice>, uint32_t> m_txTrace;

  /**

   * \brief Callback to trace RX (reception) packets.

   *

   * Data passed:

   * \li Packet received (including 6LoWPAN header)

   * \li Ptr to SixLowPanNetDevice

   * \li interface index

   */

  TracedCallback<Ptr<const Packet>, Ptr<SixLowPanNetDevice>, uint32_t> m_rxTrace;

  /**

   * \brief Callback to trace drop packets.

   *

   * Data passed:

   * \li DropReason

   * \li Packet dropped (including 6LoWPAN header)

   * \li Ptr to SixLowPanNetDevice

   * \li interface index

   */

  TracedCallback<DropReason, Ptr<const Packet>, Ptr<SixLowPanNetDevice>, uint32_t> m_dropTrace;

  /**

   */

  Ipv6Address MakeLinkLocalAddressFromMac (Address const &addr);

  /**

   */

  Ipv6Address MakeGlobalAddressFromMac (Address const &addr, Ipv6Address prefix);

  /**

   * \brief Compress the headers according to HC1 compression.

   */

  uint32_t CompressLowPanHc1 (Ptr<Packet> packet, Address const &src, Address const &dst);

  /**

   * \brief Decompress the headers according to HC1 compression.

   */

  void DecompressLowPanHc1 (Ptr<Packet> packet, Address const &src, Address const &dst);

  /**

   * \brief Compress the headers according to IPHC compression.

   */

  uint32_t CompressLowPanIphc (Ptr<Packet> packet, Address const &src, Address const &dst);

  /**

   * \brief Checks if the next header can be compressed using NHC.

   */

  bool CanCompressLowPanNhc (uint8_t headerType);

  /**

   * \brief Decompress the headers according to IPHC compression.

   */

  void DecompressLowPanIphc (Ptr<Packet> packet, Address const &src, Address const &dst);

  /**

   * \brief Compress the headers according to NHC compression.

   */

  uint32_t CompressLowPanNhc (Ptr<Packet> packet, uint8_t headerType, Address const &src, Address const &dst);

  /**

   * \brief Decompress the headers according to NHC compression.

   */

  uint8_t DecompressLowPanNhc (Ptr<Packet> packet, Address const &src, Address const &dst, Ipv6Address srcAddress, Ipv6Address dstAddress);

  /**

   * \brief Compress the headers according to NHC compression.

   */

  uint32_t CompressLowPanUdpNhc (Ptr<Packet> packet, bool omitChecksum);

  /**

   * \brief Decompress the headers according to NHC compression.

   */

  void DecompressLowPanUdpNhc (Ptr<Packet> packet, Ipv6Address saddr, Ipv6Address daddr);

  /**

   */

  typedef std::pair< std::pair<Address, Address>, std::pair<uint16_t, uint16_t> > FragmentKey;

  /**

   * \class Fragments

   */

  class Fragments : public SimpleRefCount<Fragments>

  {

public:

    /**

     * \brief Constructor.

     */

    Fragments ();

    /**

     * \brief Destructor.

     */

    ~Fragments ();

    /**

     * \brief Add a fragment to the pool.

     */

    void AddFragment (Ptr<Packet> fragment, uint16_t fragmentOffset);

    /**

     * \brief Add the first packet fragment. The first fragment is needed to

     * allow the post-defragmentation decompression.

     */

    void AddFirstFragment (Ptr<Packet> fragment);

    /**

     * \brief If all fragments have been added.

     */

    bool IsEntire () const;

    /**

     * \brief Get the entire packet.

     */

    Ptr<Packet> GetPacket () const;

    /**

     * \brief Set the packet-to-be-defragmented size.

     */

    void SetPacketSize (uint32_t packetSize);

    /**

     * \brief Get a list of the current stored fragments.

     */

    std::list< Ptr<Packet> > GetFraments () const;

private:

    /**

     * \brief The size of the reconstructed packet (bytes).

     */

    uint32_t m_packetSize;

    /**

     * \brief The current fragments.

     */

    std::list<std::pair<Ptr<Packet>, uint16_t> > m_fragments;

    /**

     */

    Ptr<Packet> m_firstFragment;

  };

  /**

   */

  void DoFragmentation (Ptr<Packet> packet, uint32_t origPacketSize, uint32_t origHdrSize,

                        std::list<Ptr<Packet> >& listFragments);

  /**

   */

  bool ProcessFragment (Ptr<Packet>& packet, Address const &src, Address const &dst, bool isFirst);

  /**

   */

  void HandleFragmentsTimeout ( FragmentKey key, uint32_t iif);

  /**

   */

  void DropOldestFragmentSet ();

  /**

   */

  typedef std::map< FragmentKey, Ptr<Fragments> > MapFragments_t;

  /**

   */

  typedef std::map< FragmentKey, Ptr<Fragments> >::iterator MapFragmentsI_t;

  /**

   */

  typedef std::map< FragmentKey, EventId > MapFragmentsTimers_t;

  /**

   */

  typedef std::map< FragmentKey, EventId >::iterator MapFragmentsTimersI_t;

  /**

   * \brief How many packets can be rebuilt at the same time.

   * Some real implementation do limit this. Zero means no limit.

   */

  uint16_t             m_fragmentReassemblyListSize;

  /**

   * \brief Force the EtherType number.

   */

  bool m_forceEtherType;

  Ptr<UniformRandomVariable> m_rng; //!< Rng for the fragments tag.

};

} // namespace ns3