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

/* 

 * Copyright (c) 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

 * 

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

 */

#include "ie-dot11s-configuration.h"

#include "ie-dot11s-peer-management.h"

#include "peer-management-plugin.h"

#include "peer-management-protocol.h"

#include "peer-link-frame.h"

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

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

#include "ns3/simulator.h"

#include "ns3/wifi-mac-header.h"

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

#include "ns3/log.h"

NS_LOG_COMPONENT_DEFINE("PeerManager");

namespace ns3 {

namespace dot11s {

PeerManagerMacPlugin::PeerManagerMacPlugin (uint32_t interface, Ptr<PeerManagementProtocol> protocol)

{

  m_ifIndex = interface;

  m_protocol = protocol;

}

PeerManagerMacPlugin::~PeerManagerMacPlugin ()

{

}

void

PeerManagerMacPlugin::SetParent (Ptr<MeshWifiInterfaceMac> parent)

{

  m_parent = parent;

}

bool

PeerManagerMacPlugin::Receive (Ptr<Packet> const_packet, const WifiMacHeader & header)

{

  // First of all we copy a packet, because we need to remove some

  //headers

  Ptr<Packet> packet = const_packet->Copy();

  if(header.IsBeacon())

  {

    IeBeaconTiming beaconTiming;

    Ptr<Packet> myBeacon = packet->Copy();

    MgtBeaconHeader beacon_hdr;

    myBeacon->RemoveHeader(beacon_hdr);

    bool meshBeacon = false;

    if(beaconTiming.FindFirst(myBeacon))

      meshBeacon = true;

    m_protocol->UpdatePeerBeaconTiming(

        m_ifIndex,

        meshBeacon,

        beaconTiming,

        header.GetAddr2(),

        Simulator::Now(),

        MicroSeconds(beacon_hdr.GetBeaconIntervalUs())

        );

    // Beacon shall not be dropeed. May be needed to another plugins

    return true;

  }

  if(header.IsMultihopAction())

  {

    WifiMeshHeader meshHdr;

    packet->RemoveHeader (meshHdr);

    WifiMeshMultihopActionHeader multihopHdr;

    //parse multihop action header:

    packet->RemoveHeader (multihopHdr);

    WifiMeshMultihopActionHeader::ACTION_VALUE actionValue = multihopHdr.GetAction ();

    // If can not handle - just return;

    if(multihopHdr.GetCategory () != WifiMeshMultihopActionHeader::MESH_PEER_LINK_MGT)

      return true;

    NS_ASSERT(meshHdr.GetMeshTtl () == 1);

    NS_ASSERT(meshHdr.GetAddressExt () == 1);

    Mac48Address peerAddress = header.GetAddr2 ();

    PeerLinkFrameStart::PlinkFrameStartFields fields;

    {

      PeerLinkFrameStart peerFrame;

      packet->RemoveHeader (peerFrame);

      fields = peerFrame.GetFields();

    }

    if (actionValue.peerLink != WifiMeshMultihopActionHeader::PEER_LINK_CLOSE)

    {

      if(!(m_parent->CheckSupportedRates(fields.rates)))

      {

        m_protocol->ConfigurationMismatch (m_ifIndex, peerAddress);

        // Broken peer link frame - drop it

        return false;

      }

      if (!fields.meshId.IsEqual(m_parent->GetSsid()))

      {

        m_protocol->ConfigurationMismatch (m_ifIndex, peerAddress);

        // Broken peer link frame - drop it

        return true;

      }

    }

    // MeshConfiguration Element - exists in all peer link management

    // frames except CLOSE

    IeConfiguration meshConfig;

    if(fields.subtype != IePeerManagement::PEER_CLOSE)

      packet->RemoveHeader(meshConfig);

    IePeerManagement peerElement;

    packet->RemoveHeader(peerElement);

    // Check the correspondance betwee action valuse and peer link

    // management element subtypes:

    switch (actionValue.peerLink)

    {

      case WifiMeshMultihopActionHeader::PEER_LINK_CONFIRM:

        NS_ASSERT(fields.subtype == IePeerManagement::PEER_CONFIRM);

        break;

      case WifiMeshMultihopActionHeader::PEER_LINK_OPEN:

        NS_ASSERT(fields.subtype == IePeerManagement::PEER_OPEN);

        break;

      case WifiMeshMultihopActionHeader::PEER_LINK_CLOSE:

        NS_ASSERT(fields.subtype == IePeerManagement::PEER_CLOSE);

        break;

      default:

        // Protocol can not define which frame is it - pass further

        return true;

    }

    //Deliver Peer link management frame to protocol:

    // if we can handle a frame - drop it

    return false;

  }

  return m_protocol->IsActiveLink(m_ifIndex,header.GetAddr2());

}

bool

PeerManagerMacPlugin::UpdateOutcomingFrame (Ptr<Packet> packet, WifiMacHeader & header, Mac48Address from, Mac48Address to) const

{

  return true;

}

void

PeerManagerMacPlugin::UpdateBeacon (MeshWifiBeacon & beacon) const

{

  Ptr<IeBeaconTiming>  beaconTiming = m_protocol->GetBeaconTimingElement(m_ifIndex);

  beacon.AddInformationElement(beaconTiming);

}

void

PeerManagerMacPlugin::SendPeerLinkManagementFrame(

      Mac48Address peerAddress,

      uint16_t aid,

      IePeerManagement peerElement,

      IeConfiguration meshConfig

      )

{

  //Create a packet:

  Ptr<Packet> packet = Create<Packet> ();

  packet->AddHeader (peerElement);

  if(!peerElement.SubtypeIsClose())

    packet->AddHeader (meshConfig);

  PeerLinkFrameStart::PlinkFrameStartFields fields;

  fields.subtype = peerElement.GetSubtype();

  fields.aid = aid;

  fields.rates = m_parent->GetSupportedRates ();

  fields.meshId = m_parent->GetSsid ();

  PeerLinkFrameStart plinkFrame;

  plinkFrame.SetPlinkFrameStart(fields);

  packet->AddHeader (plinkFrame);

  //Create an 802.11 frame header:

  //Send management frame to MAC:

  WifiMeshMultihopActionHeader multihopHdr;

  if (peerElement.SubtypeIsOpen ())

    {

      WifiMeshMultihopActionHeader::ACTION_VALUE action;

      action.peerLink = WifiMeshMultihopActionHeader::PEER_LINK_OPEN;

      multihopHdr.SetAction (WifiMeshMultihopActionHeader::MESH_PEER_LINK_MGT, action);

    }

  if (peerElement.SubtypeIsConfirm ())

    {

      WifiMeshMultihopActionHeader::ACTION_VALUE action;

      action.peerLink = WifiMeshMultihopActionHeader::PEER_LINK_CONFIRM;

      multihopHdr.SetAction (WifiMeshMultihopActionHeader::MESH_PEER_LINK_MGT, action);

    }

  if (peerElement.SubtypeIsClose ())

    {

      WifiMeshMultihopActionHeader::ACTION_VALUE action;

      action.peerLink = WifiMeshMultihopActionHeader::PEER_LINK_CLOSE;

      multihopHdr.SetAction (WifiMeshMultihopActionHeader::MESH_PEER_LINK_MGT, action);

    }

  packet->AddHeader (multihopHdr);

  //mesh header:

  WifiMeshHeader meshHdr;

  meshHdr.SetMeshTtl (1);

  meshHdr.SetMeshSeqno (0);

  meshHdr.SetAddressExt(1);

  packet->AddHeader (meshHdr);

  //Wifi Mac header:

  WifiMacHeader hdr;

  hdr.SetMultihopAction ();

  hdr.SetAddr1 (peerAddress);

  hdr.SetAddr2 (m_parent->GetAddress ());

  hdr.SetDsNotFrom ();

  hdr.SetDsNotTo ();

  m_parent->SendManagementFrame(packet, hdr);

}

Mac48Address

PeerManagerMacPlugin::GetAddress () const

{

  if(m_parent !=  0)

    return m_parent->GetAddress ();

  else return Mac48Address::Mac48Address();

}

std::pair<Time, Time> 

PeerManagerMacPlugin::GetBeaconInfo() const

{

  std::pair<Time,Time> retval;

  retval.first = m_parent->GetTbtt ();

  retval.second = m_parent->GetBeaconInterval ();

  return retval;

}

void

PeerManagerMacPlugin::SetBeaconShift(Time shift)

{

  m_parent->ShiftTbtt (shift);

}

} // namespace dot11s

} //namespace ns3