/* -*- 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: Sebastien Vincent <vincent@clarinet.u-strasbg.fr>

 */

#ifndef NDISC_CACHE_H

#define NDISC_CACHE_H

#include <stdint.h>

#include <list>

#include "ns3/packet.h"

#include "ns3/nstime.h"

#include "ns3/net-device.h"

#include "ns3/ipv6-address.h"

#include "ns3/ptr.h"

#include "ns3/timer.h"

#include "ns3/sgi-hashmap.h"

namespace ns3

{

class NetDevice;

class Ipv6Interface;

/**

 * \class NdiscCache

 * \brief IPv6 Neighbor Discovery cache.

 */

class NdiscCache : public Object

{

public:

  class Entry;

  /**

   * \brief Get the type ID

   * \return type ID

   */

  static TypeId GetTypeId ();

  /**

   * \brief Default value for unres qlen.

   */

  static const uint32_t DEFAULT_UNRES_QLEN = 3;

  /**

   * \brief Constructor.

   */

  NdiscCache ();

  /**

   * \brief Destructor.

   */

  ~NdiscCache ();

  /**

   * \brief Get the NetDevice associated with this cache.

   * \return NetDevice

   */

  Ptr<NetDevice> GetDevice () const;

  /**

   * \brief Get the Ipv6Interface associated with this cache.

   */

  Ptr<Ipv6Interface> GetInterface () const;

  /**

   * \brief Lookup in the cache.

   * \param dst destination address

   * \return the entry if found, 0 otherwise

   */

  NdiscCache::Entry* Lookup (Ipv6Address dst);

  /**

   * \brief Add an entry.

   * \param to address to add

   * \return an new Entry

   */

  NdiscCache::Entry* Add (Ipv6Address to);

  /**

   * \brief Delete an entry.

   * \param entry pointer to delete from the list.

   */

  void Remove (NdiscCache::Entry* entry);

  /**

   * \brief Flush the cache.

   */

  void Flush ();

  /**

   * \brief Set the max number of waiting packet.

   * \param unresQlen value to set

   */

  void SetUnresQlen (uint32_t unresQlen);

  /**

   * \brief Get the max number of waiting packet.

   * \return max number

   */

  uint32_t GetUnresQlen ();

  /**

   * \brief Set the device and interface.

   * \param device the device

   * \param interface the IPv6 interface

   */

  void SetDevice (Ptr<NetDevice> device, Ptr<Ipv6Interface> interface);

  /**

   * \class Entry

   * \brief A record that holds information about an NdiscCache entry.

   */

  class Entry

  {

public:

    /**

     * \brief Constructor.

     * \param nd The NdiscCache this entry belongs to.

     */

    Entry (NdiscCache* nd);

    /**

     * \brief Changes the state to this entry to INCOMPLETE.

     * \param p packet that wait to be sent

     */

    void MarkIncomplete (Ptr<Packet> p);

    /**

     * \brief Changes the state to this entry to REACHABLE.

     * \param mac MAC address

     * \return the list of packet waiting

     */

    std::list<Ptr<Packet> > MarkReachable (Address mac);

    /**

     * \brief Changes the state to this entry to PROBE.

     */

    void MarkProbe ();

    /**

     * \brief Changes the state to this entry to STALE.

     * \param mac L2 address

     * \return the list of packet waiting

     */

    std::list<Ptr<Packet> > MarkStale (Address mac);

    /**

     * \brief Changes the state to this entry to STALE.

     */

    void MarkStale ();

    /**

     * \brief Changes the state to this entry to REACHABLE.

     */

    void MarkReachable ();

    /**

     * \brief Change the state to this entry to DELAY.

     */

    void MarkDelay ();

    /**

     * \brief Add a packet (or replace old value) in the queue.

     * \param p packet to add

     */

    void AddWaitingPacket (Ptr<Packet> p);

    /**

     * \brief Clear the waiting packet list.

     */

    void ClearWaitingPacket ();

    /**

     * \brief Is the entry STALE

     * \return true if the entry is in STALE state, false otherwise

     */

    bool IsStale () const;

    /**

     * \brief Is the entry REACHABLE

     * \return true if the entry is in REACHABLE state, false otherwise

     */

    bool IsReachable () const;

    /**

     * \brief Is the entry DELAY

     * \return true if the entry is in DELAY state, false otherwise

     */

    bool IsDelay () const;

    /**

     * \brief Is the entry INCOMPLETE

     * \return true if the entry is in INCOMPLETE state, false otherwise

     */

    bool IsIncomplete () const;

    /**

     * \brief Is the entry PROBE

     * \return true if the entry is in PROBE state, false otherwise

     */

    bool IsProbe () const;

    /**

     * \brief Get the MAC address of this entry.

     * \return the L2 address

     */

    Address GetMacAddress () const;

    /**

     * \brief Set the MAC address of this entry.

     * \param mac the MAC address to set

     */

    void SetMacAddress (Address mac);

    /**

     * \brief If the entry is a host or a router.

     * \return true if the node is a router, 0 if it is a host

     */

    bool IsRouter () const;

    /**

     * \brief Set the node type.

     * \param router true is a router, false means a host

     */

    void SetRouter (bool router);

    /**

     * \brief Get the number of NS retransmit.

     * \return number of NS that have been retransmit

     */

    uint8_t GetNSRetransmit () const;

    /**

     * \brief Increment NS retransmit.

     */

    void IncNSRetransmit ();

    /**

     * \brief Reset NS retransmit (=0).

     */

    void ResetNSRetransmit ();

    /**

     * \brief Get the time of last reachability confirmation.

     * \return time

     */

    Time GetLastReachabilityConfirmation () const;

    /**

     * \brief Update the time of last reachability confirmation.

     */

    void UpdateLastReachabilityconfirmation ();

    /**

     * \brief Start the reachable timer.

     */

    void StartReachableTimer ();

    /**

     * \brief Stop the reachable timer.

     */

    void StopReachableTimer ();

    /**

     * \brief Start retransmit timer.

     */

    void StartRetransmitTimer ();

    /**

     * \brief Stop retransmit timer.

     */

    void StopRetransmitTimer ();

    /**

     * \brief Start probe timer.

     */

    void StartProbeTimer ();

    /**

     * \brief Stop probe timer.

     */

    void StopProbeTimer ();

    /**

     * \brief Start delay timer.

     */

    void StartDelayTimer ();

    /**

     * \brief Stop delay timer.

     */

    void StopDelayTimer ();

    /**

     * \brief Function called when reachable timer timeout.

     */

    void FunctionReachableTimeout ();

    /**

     * \brief Function called when retransmit timer timeout.

     * It verify that the NS retransmit has reached the max so discard the entry

     * otherwise it retransmit a NS.

     */

    void FunctionRetransmitTimeout ();

    /**

     * \brief Function called when probe timer timeout.

     */

    void FunctionProbeTimeout ();

    /**

     * \brief Function called when delay timer timeout.

     */

    void FunctionDelayTimeout ();

    /**

     * \brief Set the IPv6 address.

     * \param ipv6Address IPv6 address

     */

    void SetIpv6Address (Ipv6Address ipv6Address);

private:

    /**

     * \brief The IPv6 address.

     */

    Ipv6Address m_ipv6Address;

    /**

     * \brief The Entry state enumeration.

     */

    enum NdiscCacheEntryState_e

    {

      INCOMPLETE, /**< No mapping between IPv6 and L2 addresses */

      REACHABLE, /**< Mapping exists between IPv6 and L2 addresses */

      STALE, /**< Mapping is stale */

      DELAY, /**< Try to wait contact from remote host */

      PROBE /**< Try to contact IPv6 address to know again its L2 address */

    };

    /**

     * \brief The state of the entry.

     */

    NdiscCacheEntryState_e m_state;

    /**

     * \brief the NdiscCache associated.

     */

    NdiscCache* m_ndCache;

    /**

     * \brief The MAC address.

     */

    Address m_macAddress;

    /**

     * \brief The list of packet waiting.

     */

    std::list<Ptr<Packet> > m_waiting;

    /**

     * \brief Type of node (router or host).

     */

    bool m_router;

    /**

     * \brief Reachable timer (used for NUD in REACHABLE state).

     */

    Timer m_reachableTimer;

    /**

     * \brief Retransmission timer (used for NUD in INCOMPLETE state).

     */

    Timer m_retransTimer;

    /**

     * \brief Probe timer (used for NUD in PROBE state).

     */

    Timer m_probeTimer;

    /**

     * \brief Delay timer (used for NUD when in DELAY state).

     */

    Timer m_delayTimer;

    /**

     * \brief Last time we see a reachability confirmation.

     */

    Time m_lastReachabilityConfirmation;

    /**

     * \brief Number of NS retransmission.

     */

    uint8_t m_nsRetransmit;

  };

private:

  /**

   * \brief Neighbor Discovery Cache container

   */

  typedef sgi::hash_map<Ipv6Address, NdiscCache::Entry *, Ipv6AddressHash> Cache;

  /**

   * \brief Neighbor Discovery Cache container iterator

   */

  typedef sgi::hash_map<Ipv6Address, NdiscCache::Entry *, Ipv6AddressHash>::iterator CacheI;

  /**

   * \brief Copy constructor.

   *

   * Not implemented to avoid misuse

   */

  NdiscCache (NdiscCache const &);

  /**

   * \brief Copy constructor.

   *

   * Not implemented to avoid misuse

   * \returns

   */

  NdiscCache& operator= (NdiscCache const &);

  /**

   * \brief Dispose this object.

   */

  void DoDispose ();

  /**

   * \brief The NetDevice.

   */

  Ptr<NetDevice> m_device;

  /**

   * \brief the interface.

   */

  Ptr<Ipv6Interface> m_interface;

  /**

   * \brief A list of Entry.

   */

  Cache m_ndCache;

  /**

   * \brief Max number of packet stored in m_waiting.

   */

  uint32_t m_unresQlen;

};

} /* namespace ns3 */

#endif /* NDISC_CACHE_H */