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

/*

 * Copyright (c) 2008,2009 IITP RAS

 *

 * 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

 *

 * Authors: Kirill Andreev <andreev@iitp.ru>

 */

#ifndef HWMP_PROTOCOL_H

#define HWMP_PROTOCOL_H

#include "ns3/mesh-l2-routing-protocol.h"

#include "ns3/nstime.h"

#include "ns3/event-id.h"

#include "ie-dot11s-perr.h"

#include <vector>

#include <map>

namespace ns3 {

class MeshPointDevice;

class Packet;

class Mac48Address;

namespace dot11s {

class HwmpProtocolMac;

class HwmpRtable;

class IePreq;

class IePrep;

/**

 * \ingroup dot11s

 *

 * \brief Hybrid wireless mesh protocol -- a routing protocol of IEEE 802.11s draft.

 */

class HwmpProtocol : public MeshL2RoutingProtocol

{

public:

  static TypeId GetTypeId ();

  HwmpProtocol ();

  ~HwmpProtocol ();

  void DoDispose ();

  /// Route request, inherited from MeshL2RoutingProtocol

  bool RequestRoute (uint32_t  sourceIface, const Mac48Address source, const Mac48Address destination,

      Ptr<const Packet>  packet, uint16_t  protocolType, RouteReplyCallback  routeReply);

  /// Cleanup packet from all tags

  bool RemoveRoutingStuff (uint32_t fromIface, const Mac48Address source,

      const Mac48Address destination, Ptr<Packet>  packet, uint16_t&  protocolType);

  /**

   * \brief Install HWMP on given mesh point.

   *

   * Installing protocol cause installing its interface MAC plugins.

   *

   * Also MP aggregates all installed protocols, HWMP protocol can be accessed

   * via MeshPointDevice::GetObject<dot11s::HwmpProtocol>();

   */

  bool Install (Ptr<MeshPointDevice>);

  void PeerLinkStatus (Mac48Address meshPontAddress, Mac48Address peerAddress, uint32_t interface,bool status);

  ///\brief This callback is used to obtain active neighbours on a

  //given interface

  ///\param interface is the interface ID

  void SetNeighboursCallback (Callback<std::vector<Mac48Address>, uint32_t> cb);

  ///\name Proactive PREQ mechanism:

  ///\{

  void SetRoot ();

  void UnsetRoot ();

  ///\}

  ///\brief Statistics:

  void Report (std::ostream &) const;

  void ResetStats ();

private:

  friend class HwmpProtocolMac;

  /// Like RequestRoute, but for unicast packets

  bool ForwardUnicast (uint32_t  sourceIface, const Mac48Address source, const Mac48Address destination,

      Ptr<Packet>  packet, uint16_t  protocolType, RouteReplyCallback  routeReply, uint32_t ttl);

  ///\name Interaction with HWMP MAC plugin

  //\{

  void ReceivePreq (IePreq preq, Mac48Address from, uint32_t interface, Mac48Address fromMp, uint32_t metric);

  void ReceivePrep (IePrep prep, Mac48Address from, uint32_t interface, Mac48Address fromMp, uint32_t metric);

  void ReceivePerr (std::vector<IePerr::FailedDestination>, Mac48Address from, uint32_t interface, Mac48Address fromMp);

  void SendPrep (

      Mac48Address src,

      Mac48Address dst,

      Mac48Address retransmitter,

      uint32_t initMetric,

      uint32_t originatorDsn,

      uint32_t destinationSN,

      uint32_t lifetime,

      uint32_t interface);

  /**

   * \brief Structure of path error: IePerr and list of receivers:

   * interfaces and MAC address

   */

  struct PathError

  {

    std::vector<IePerr::FailedDestination> destinations;

    /// interface-address

    std::vector<std::pair<uint32_t, Mac48Address> > receivers;

  };

  /**

   * \brief forms a path error information element when list of destination fails on a given interface

   * \attention removes all entries from routing table!

   */

  PathError MakePathError (std::vector<IePerr::FailedDestination> destinations);

  ///\brief Forwards a received path error

  void ForwardPathError (PathError perr);

  ///\brief Pasess a selg-generated PERR to interface-plugin

  void InitiatePathError (PathError perr);

  /// \return list of addresses where a PERR should be sent to

  std::vector<std::pair<uint32_t, Mac48Address> > GetPerrReceivers (std::vector<IePerr::FailedDestination> failedDest);

  /// \return list of addresses where a PERR should be sent to

  std::vector<Mac48Address> GetPreqReceivers (uint32_t interface);

  /// \return list of addresses where a broadcast should be

  //retransmitted

  std::vector<Mac48Address> GetBroadcastReceivers (uint32_t interface);

  /**

   * \brief MAC-plugin asks wether the frame can be dropeed. Protocol automatically updates seqno.

   *

   * \return true if frame can be dropped

   * \param uint32_t is the seqno

   * \param Mac48Address is the mesh source addrress of the frame

   */

  bool DropDataFrame (uint32_t, Mac48Address);

  //\}

private:

  /// Packet waiting its routing information

  struct QueuedPacket {

    Ptr<Packet> pkt; ///< the packet

    Mac48Address src; ///< src address

    Mac48Address dst; ///< dst address

    uint16_t protocol; ///< protocol number

    uint32_t inInterface; ///< incoming device interface ID. (if packet has come from upper layers, this is Mesh point ID)

    RouteReplyCallback reply; ///< how to reply

  };

  ///\name Methods related to Queue/Dequeue procedures

  //\{

  bool QueuePacket (QueuedPacket packet);

  QueuedPacket  DequeueFirstPacketByDst (Mac48Address dst);

  QueuedPacket  DequeueFirstPacket ();

  void ReactivePathResolved (Mac48Address dst);

  void ProactivePathResolved ();

  //\}

  ///\name Statistics:

  ///\{

  struct Statistics

  {

    uint16_t txUnicast;

    uint16_t txBroadcast;

    uint32_t txBytes;

    uint16_t droppedTtl;

    uint16_t totalQueued;

    uint16_t totalDropped;

    uint16_t initiatedPreq;

    uint16_t initiatedPrep;

    uint16_t initiatedPerr;

    void Print (std::ostream & os) const;

    Statistics ();

  };

  Statistics m_stats;

  ///\}

  ///\name Methods responsible for path discovery retry procedure:

  //\{

  /**

   * \brief checks when the last path discovery procedure was started for a given destination.

   *

   * If the retry counter has not achieved the maximum level - preq should not be sent

   */

  bool  ShouldSendPreq (Mac48Address dst);

  /**

   * \brief Generates PREQ retry when retry timeout has expired and route is still unresolved.

   *

   * When PREQ retry has achieved the maximum level - retry mechanish should be cancelled

   */

  void  RetryPathDiscovery (Mac48Address dst, uint8_t numOfRetry);

  //\}

  ///\name Proactive Preq routines:

  //\{

  void SendProactivePreq ();

  //\}

  ///\return address of MeshPointDevice

  Mac48Address GetAddress ();

private:

  typedef std::map<uint32_t, Ptr<HwmpProtocolMac> > HwmpProtocolMacMap;

  HwmpProtocolMacMap m_interfaces;

  Mac48Address m_address;

  uint32_t m_dataSeqno;

  uint32_t m_hwmpSeqno;

  uint32_t m_preqId;

  ///\name Sequence number filters

  //\{

  /// Data sequence number database

  std::map<Mac48Address, uint32_t> m_lastDataSeqno;

  /// DSN databse

  std::map<Mac48Address, uint32_t> m_lastHwmpSeqno;

  /// Metric database

  std::map<Mac48Address, uint32_t> m_lastHwmpMetric;

  //\}

  /// Routing table

  Ptr<HwmpRtable> m_rtable;

  ///\name Timers:

  //\{

  std::map<Mac48Address, EventId> m_preqTimeouts;

  EventId m_proactivePreqTimer;

  //Random start in Proactive PREQ propagation

  Time m_randomStart;

  //\}

  /// Packet Queue

  std::vector<QueuedPacket> m_rqueue;

private:

  ///\name HWMP-protocol parameters (attributes of GetTypeId)

  //\{

  uint16_t m_maxQueueSize;

  uint8_t m_dot11MeshHWMPmaxPREQretries;

  Time m_dot11MeshHWMPnetDiameterTraversalTime;

  Time m_dot11MeshHWMPpreqMinInterval;

  Time m_dot11MeshHWMPperrMinInterval;

  Time m_dot11MeshHWMPactiveRootTimeout;

  Time m_dot11MeshHWMPactivePathTimeout;

  Time m_dot11MeshHWMPpathToRootInterval;

  Time m_dot11MeshHWMPrannInterval;

  bool m_isRoot;

  uint8_t m_maxTtl;

  uint8_t m_unicastPerrThreshold;

  uint8_t m_unicastPreqThreshold;

  uint8_t m_unicastDataThreshold;

  bool m_doFlag;

  bool m_rfFlag;

  //\}

  ///\name Methods needed by HwmpMacLugin to access protocol parameters:

  //\{

  bool GetDoFlag ();

  bool GetRfFlag ();

  Time GetPreqMinInterval ();

  Time GetPerrMinInterval ();

  uint8_t GetMaxTtl ();

  uint32_t GetNextPreqId ();

  uint32_t GetNextHwmpSeqno ();

  uint32_t GetActivePathLifetime ();

  uint8_t GetUnicastPerrThreshold ();

  //\}

  Callback <std::vector<Mac48Address>, uint32_t> m_neighboursCallback;

};

} //namespace dot11s

} //namespace ns3

#endif