/* -*-  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>

 */

#include "hwmp-protocol.h"

#include "hwmp-mac-plugin.h"

#include "hwmp-tag.h"

#include "hwmp-rtable.h"

#include "ns3/log.h"

#include "ns3/simulator.h"

#include "ns3/packet.h"

#include "ns3/mesh-point-device.h"

#include "ns3/wifi-net-device.h"

#include "ns3/mesh-point-device.h"

#include "ns3/mesh-wifi-interface-mac.h"

#include "ie-dot11s-preq.h"

#include "ie-dot11s-prep.h"

#include "ie-dot11s-perr.h"

NS_LOG_COMPONENT_DEFINE ("HwmpProtocol");

namespace ns3 {

namespace dot11s {

NS_OBJECT_ENSURE_REGISTERED (HwmpProtocol);

TypeId

HwmpProtocol::GetTypeId ()

{

  static TypeId tid = TypeId ("ns3::dot11s::HwmpProtocol")

    .SetParent<MeshL2RoutingProtocol> ()

    .AddConstructor<HwmpProtocol> ()

    .AddAttribute ("dot11MeshHWMPmaxPREQretries",

        "Maximum number of retries before we suppose the destination to be unreachable",

        UintegerValue (3),

        MakeUintegerAccessor (&HwmpProtocol::m_dot11MeshHWMPmaxPREQretries),

        MakeUintegerChecker<uint8_t> (1)

        )

    .AddAttribute ("dot11MeshHWMPnetDiameterTraversalTime",

        "Time we suppose the packet to go from one edge of the network to another",

        TimeValue (MicroSeconds (1024*10)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPnetDiameterTraversalTime),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPpreqMinInterval",

        "Minimal interval between to successive PREQs",

        TimeValue (MicroSeconds (1024*100)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPpreqMinInterval),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPperrMinInterval",

        "Minimal interval between to successive PREQs",

        TimeValue (MicroSeconds (1024*100)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPperrMinInterval),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPactiveRootTimeout",

        "Lifetime of poractive routing information",

        TimeValue (MicroSeconds (1024*5000)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPactiveRootTimeout),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPactivePathTimeout",

        "Lifetime of reactive routing information",

        TimeValue (MicroSeconds (1024*5000)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPactivePathTimeout),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPpathToRootInterval",

        "Interval between two successive proactive PREQs",

        TimeValue (MicroSeconds (1024*5000)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPpathToRootInterval),

        MakeTimeChecker ()

        )

    .AddAttribute ("dot11MeshHWMPrannInterval",

        "Lifetime of poractive routing information",

        TimeValue (MicroSeconds (1024*5000)),

        MakeTimeAccessor (&HwmpProtocol::m_dot11MeshHWMPrannInterval),

        MakeTimeChecker ()

        )

  .AddAttribute ("maxQueueSize",

        "Maximum number of packets we can store when resolving route",

        UintegerValue (255),

        MakeUintegerAccessor (&HwmpProtocol::m_maxQueueSize),

        MakeUintegerChecker<uint16_t> (1)

        )

  .AddAttribute ("maxTtl",

        "Initial value of Time To Live field",

        UintegerValue (32),

        MakeUintegerAccessor (&HwmpProtocol::m_maxTtl),

        MakeUintegerChecker<uint8_t> (2)

        )

  .AddAttribute ("unicastPerrThreshold",

        "Maximum number of PERR receivers, when we send a PERR as a chain of unicasts",

        UintegerValue (32),

        MakeUintegerAccessor (&HwmpProtocol::m_unicastPerrThreshold),

        MakeUintegerChecker<uint8_t> (1)

        )

  .AddAttribute ("unicastPreqThreshold",

        "Maximum number of PREQ receivers, when we send a PREQ as a chain of unicasts",

        UintegerValue (0),

        MakeUintegerAccessor (&HwmpProtocol::m_unicastPreqThreshold),

        MakeUintegerChecker<uint8_t> (0)

        );

  return tid;

}

HwmpProtocol::HwmpProtocol ():

    m_dataSeqno (1),

    m_hwmpSeqno (1),

    m_preqId (0),

    m_rtable (CreateObject<HwmpRtable> ()),

    m_isRoot (false),

    m_doFlag (false),

    m_rfFlag (false)

{

}

HwmpProtocol::~HwmpProtocol ()

{

}

void

HwmpProtocol::DoDispose ()

{

  for (std::map<Mac48Address, EventId>::iterator i = m_preqTimeouts.begin (); i != m_preqTimeouts.end(); i ++)

    i->second.Cancel ();

  m_preqTimeouts.clear ();

  m_lastDataSeqno.clear ();

  m_lastHwmpSeqno.clear ();

  m_rqueue.clear ();

  m_rtable = 0;

  //TODO: clear plugins

}

bool

HwmpProtocol::RequestRoute (

  uint32_t sourceIface,

  const Mac48Address source,

  const Mac48Address destination,

  Ptr<Packet> packet,

  uint16_t protocolType, //ethrnet 'Protocol' field

  MeshL2RoutingProtocol::RouteReplyCallback routeReply

)

{

  HwmpTag tag;

  if (sourceIface == GetMeshPoint ()->GetIfIndex())

    // packet from level 3

  {

    NS_ASSERT (!packet->PeekPacketTag(tag));

    //Filling TAG:

    if(destination == Mac48Address::GetBroadcast ())

    {

      tag.SetSeqno (m_dataSeqno++);

      tag.SetAddress (Mac48Address::GetBroadcast());

      tag.SetTtl (m_maxTtl+1);

      if (m_dataSeqno == 0xffffffff)

        m_dataSeqno = 0;

      NS_LOG_UNCOND("add a tag"<<packet->GetUid());

      packet->AddPacketTag(tag);

    }

  }

  else

  {

    NS_ASSERT (packet->PeekPacketTag(tag));

    if (tag.GetTtl () == 0)

      return false;

    tag.DecrementTtl ();

  }

  if (destination == Mac48Address::GetBroadcast ())

    routeReply (true, packet, source, destination, protocolType, HwmpRtable::INTERFACE_ANY);

  else

    return ForwardUnicast(sourceIface, source, destination, packet, protocolType, routeReply);

  return true;

}

bool

HwmpProtocol::ForwardUnicast(uint32_t  sourceIface, const Mac48Address source, const Mac48Address destination,

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

{

  NS_ASSERT(destination != Mac48Address::GetBroadcast ());

  HwmpRtable::LookupResult result = m_rtable->LookupReactive(destination);

  if(result.retransmitter == Mac48Address::GetBroadcast ())

    result = m_rtable->LookupProactive ();

  if(result.retransmitter != Mac48Address::GetBroadcast ())

  {

    //reply immediately:

    //packet->RemoveAllTags ();

    //Add a proper HWMP-tag:

    HwmpTag tag;

    NS_ASSERT(!packet->RemovePacketTag(tag));

    tag.SetAddress (result.retransmitter);

    //seqno and metric is not used;

    packet->AddPacketTag(tag);

    routeReply (true, packet, source, destination, protocolType, result.ifIndex);

    return true;

  }

  if (sourceIface != GetMeshPoint ()->GetIfIndex())

  {

    //Start path error procedure:

    NS_LOG_DEBUG ("Must Send PERR");

    result = m_rtable->LookupReactiveExpired (destination);

    //1.  Lookup expired reactive path. If exists - start path error

    //    procedure towards a next hop of this path

    //2.  If there was no reactive path, we lookup expired proactive

    //    path. If exist - start path error procedure towards path to

    //    root

    //3.  If and only if we are a root station - we queue packet

    if((result.retransmitter == Mac48Address::GetBroadcast ()) && (!m_isRoot))

      result = m_rtable->LookupProactiveExpired ();

    if((result.retransmitter == Mac48Address::GetBroadcast ()) && (!m_isRoot))

      return false;

    std::vector<IePerr::FailedDestination> destinations = m_rtable->GetUnreachableDestinations (result.retransmitter);

    MakePathError (destinations);

    if(!m_isRoot)

      return false;

  }

  //Request a destination:

  if(ShouldSendPreq(destination))

    for(HwmpPluginMap::iterator i = m_interfaces.begin (); i != m_interfaces.end (); i ++)

      i->second->RequestDestination(destination);

  QueuedPacket pkt;

  HwmpTag tag;

  packet->RemovePacketTag (tag);

  tag.SetAddress(Mac48Address::GetBroadcast ());

  packet->AddPacketTag (tag);

  pkt.pkt = packet;

  pkt.dst = destination;

  pkt.src = source;

  pkt.protocol = protocolType;

  pkt.reply = routeReply;

  pkt.inInterface = sourceIface;

  QueuePacket (pkt);

  return true;

}

bool

HwmpProtocol::HandleIncomingFrame (Ptr<Packet> packet, Mac48Address src, Mac48Address dst, uint16_t protocol)

{

  //Handle only incoming frames:

  NS_ASSERT(dst == m_address);

  HwmpTag tag;

  NS_ASSERT(packet->RemovePacketTag(tag));

  return true;

}

void

HwmpProtocol::ReceivePreq (IePreq preq, Mac48Address from, uint32_t interface)

{

  preq.IncrementMetric (1);

  //acceptance cretirea:

  std::map<Mac48Address, uint32_t>::iterator i = m_lastHwmpSeqno.find (preq.GetOriginatorAddress());

  if (i == m_lastHwmpSeqno.end ())

    {

      m_lastHwmpSeqno[preq.GetOriginatorAddress ()] = preq.GetOriginatorSeqNumber();

      m_lastHwmpMetric[preq.GetOriginatorAddress ()] = preq.GetMetric();

    }

  else

    {

      if (i->second > preq.GetOriginatorSeqNumber ())

        return;

      if (i->second == preq.GetOriginatorSeqNumber ())

        {

          //find metric

          std::map<Mac48Address, uint32_t>::iterator j =

            m_lastHwmpMetric.find (preq.GetOriginatorAddress());

          NS_ASSERT (j != m_lastHwmpSeqno.end());

          if (j->second <= preq.GetMetric ())

            return;

        }

      m_lastHwmpSeqno[preq.GetOriginatorAddress ()] = preq.GetOriginatorSeqNumber();

      m_lastHwmpMetric[preq.GetOriginatorAddress ()] = preq.GetMetric();

    }

  //check if can answer:

  std::vector<Ptr<DestinationAddressUnit> > destinations = preq.GetDestinationList ();

  for (std::vector<Ptr<DestinationAddressUnit> >::iterator i = destinations.begin (); i != destinations.end(); i++)

    {

      if ((*i)->GetDestinationAddress () == Mac48Address::GetBroadcast())

        {

          //only proactive PREQ contains destination

          //address as broadcast! Proactive preq MUST

          //have destination count equal to 1 and

          //per destination flags DO and RF

          NS_ASSERT (preq.GetDestCount() == 1);

          NS_ASSERT (((*i)->IsDo()) && ((*i)->IsRf()));

          m_rtable->AddProactivePath (

              preq.GetMetric (),

              preq.GetOriginatorAddress (),

              from,

              interface,

              MicroSeconds (preq.GetLifetime () * 1024),

              preq.GetOriginatorSeqNumber ()

              );

          ProactivePathResolved ();

          if (!preq.IsNeedNotPrep ())

              SendPrep (

                  m_address,

                  preq.GetOriginatorAddress (),

                  from,

                  preq.GetMetric (),

                  preq.GetOriginatorSeqNumber (),

                  GetNextHwmpSeqno (),

                  preq.GetLifetime (),

                  interface

              );

          break;

        }

      if ((*i)->GetDestinationAddress () == m_address)

        {

          NS_LOG_UNCOND("PREQ has reached destination:"<<m_address);

          preq.DelDestinationAddressElement ((*i)->GetDestinationAddress());

          SendPrep (

              m_address,

              preq.GetOriginatorAddress (),

              from,

              (uint32_t)0,

              preq.GetOriginatorSeqNumber (),

              GetNextHwmpSeqno (),

              preq.GetLifetime (),

              interface

          );

          continue;

        }

      //check if can answer:

      HwmpRtable::LookupResult result = m_rtable->LookupReactive ((*i)->GetDestinationAddress());

      if ((! ((*i)->IsDo())) && (result.retransmitter != Mac48Address::GetBroadcast()))

        {

          //have a valid information and acn answer

          if ((*i)->IsRf ())

            (*i)->SetFlags (true, false); //DO = 1, RF = 0 (as it was)

          else

            {

              //send a PREP and delete destination

              preq.DelDestinationAddressElement ((*i)->GetDestinationAddress());

              SendPrep (

                  (*i)->GetDestinationAddress (),

                  preq.GetOriginatorAddress (),

                  from,

                  result.metric,

                  preq.GetOriginatorSeqNumber (),

                  result.seqnum +1,

                  preq.GetLifetime (),

                  interface

              );

              continue;

            }

        }

    }

  m_rtable->AddReactivePath (

      preq.GetOriginatorAddress (),

      from,

      interface,

      preq.GetMetric (),

      MicroSeconds (preq.GetLifetime () *1024),

      preq.GetOriginatorSeqNumber ()

      );

  ReactivePathResolved (preq.GetOriginatorAddress ());

  //m_routingInfoCallback (newInfo);

  //chack if must retransmit:

  if (preq.GetDestCount () == 0)

    return;

  //Forward PREQ to all interfaces:

  NS_LOG_UNCOND("I am "<<m_address<<"retransmitting PREQ:"<<preq);

  for(HwmpPluginMap::iterator i = m_interfaces.begin (); i != m_interfaces.end (); i ++)

    i->second->SendPreq (preq);

}

void

HwmpProtocol::ReceivePrep (IePrep prep, Mac48Address from, uint32_t interface)

{

  prep.IncrementMetric (1);

  //acceptance cretirea:

  NS_LOG_UNCOND("I am "<<m_address<<", received prep");

  std::map<Mac48Address, uint32_t>::iterator i = m_lastHwmpSeqno.find (prep.GetOriginatorAddress());

  if (i == m_lastHwmpSeqno.end ())

    {

      m_lastHwmpSeqno[prep.GetOriginatorAddress ()] = prep.GetOriginatorSeqNumber();

    }

  else

    if (i->second > prep.GetOriginatorSeqNumber ())

      return;

  //update routing info

  //Now add a path to destination and add precursor to source

  m_rtable->AddPrecursor (prep.GetDestinationAddress (), interface, from);

  m_rtable->AddReactivePath (

      prep.GetOriginatorAddress (),

      from,

      interface,

      prep.GetMetric (),

      MicroSeconds(prep.GetLifetime () * 1024),

      prep.GetOriginatorSeqNumber ());

  if(prep.GetDestinationAddress() == m_address)

    NS_LOG_UNCOND("Destination resolved:"<<prep.GetOriginatorAddress ());

  HwmpRtable::LookupResult result = m_rtable->LookupReactive(prep.GetDestinationAddress());

  if (result.retransmitter == Mac48Address::GetBroadcast ())

    //try to look for default route

    result = m_rtable->LookupProactive ();

  if (result.retransmitter == Mac48Address::GetBroadcast ())

  {

    NS_LOG_UNCOND("I am "<<m_address<<", can not forward prep");

    return;

  }

  m_rtable->AddPrecursor (prep.GetOriginatorAddress (), interface, result.retransmitter);

  //Forward PREP

  HwmpPluginMap::iterator prep_sender = m_interfaces.find (result.ifIndex);

  NS_ASSERT(prep_sender != m_interfaces.end ());

  prep_sender->second->SendPrep(prep, result.retransmitter);

}

void

HwmpProtocol::ReceivePerr (IePerr perr, Mac48Address from, uint32_t interface)

{

  //Acceptance cretirea:

  NS_LOG_UNCOND("I am "<<m_address<<", received PERR from "<<from);

  std::vector<IePerr::FailedDestination> destinations = perr.GetAddressUnitVector ();

  HwmpRtable::LookupResult result;

  for(unsigned int i = 0; i < destinations.size (); i ++)

  {

    result = m_rtable->LookupReactive (destinations[i].destination);

    NS_LOG_UNCOND("Destination = "<<destinations[i].destination<<", RA = "<<result.retransmitter);

    if (

        (result.retransmitter != from) ||

        (result.ifIndex != interface) ||

        (result.seqnum > destinations[i].seqnum)

        )

    {

      perr.DeleteAddressUnit(destinations[i].destination);

      continue;

    }

    m_rtable->DeleteReactivePath(destinations[i].destination);

  }

  if(perr.GetNumOfDest () == 0)

    return;

  MakePathError (destinations);

}

void

HwmpProtocol::SendPrep (

    Mac48Address src,

    Mac48Address dst,

    Mac48Address retransmitter,

    uint32_t initMetric,

    uint32_t originatorDsn,

    uint32_t destinationSN,

    uint32_t lifetime,

    uint32_t interface)

{

  NS_LOG_UNCOND("sending prep to "<<dst<<" through "<<retransmitter);

  IePrep prep;

  prep.SetHopcount (0);

  prep.SetTtl (m_maxTtl);

  prep.SetDestinationAddress (dst);

  prep.SetDestinationSeqNumber (destinationSN);

  prep.SetLifetime (lifetime);

  prep.SetMetric (0);

  prep.SetOriginatorAddress (src);

  prep.SetOriginatorSeqNumber (originatorDsn);

  HwmpPluginMap::iterator prep_sender = m_interfaces.find (interface);

  NS_ASSERT(prep_sender != m_interfaces.end ());

  prep_sender->second->SendPrep(prep, retransmitter);

  //m_prepCallback (prep, retransmitter);

}

bool

HwmpProtocol::Install (Ptr<MeshPointDevice> mp)

{

  m_mp = mp;

  std::vector<Ptr<NetDevice> > interfaces = mp->GetInterfaces ();

  for (std::vector<Ptr<NetDevice> >::iterator i = interfaces.begin (); i != interfaces.end(); i++)

    {

      // Checking for compatible net device

      const WifiNetDevice * wifiNetDev = dynamic_cast<const WifiNetDevice *> (PeekPointer (*i));

      if (wifiNetDev == NULL)

        return false;

      MeshWifiInterfaceMac * mac = dynamic_cast<MeshWifiInterfaceMac *> (PeekPointer (wifiNetDev->GetMac ()));

      if (mac == NULL)

        return false;

      // Installing plugins: