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

/*

 * Copyright (c) 2006, 2009 INRIA

 * Copyright (c) 2009 MIRKO BANCHI

 *

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 *          Mirko Banchi <mk.banchi@gmail.com>

 */

#include "adhoc-wifi-mac.h"

#include "ns3/pointer.h"

#include "ns3/log.h"

#include "ns3/string.h"

#include "ns3/boolean.h"

#include "ns3/trace-source-accessor.h"

#include "qos-tag.h"

#include "mac-low.h"

#include "dcf-manager.h"

#include "mac-rx-middle.h"

#include "mac-tx-middle.h"

#include "msdu-aggregator.h"

#include "amsdu-subframe-header.h"

#include "mgt-headers.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("AdhocWifiMac");

NS_OBJECT_ENSURE_REGISTERED (AdhocWifiMac);

TypeId

AdhocWifiMac::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::AdhocWifiMac")

    .SetParent<RegularWifiMac> ()

    .SetGroupName ("Wifi")

    .AddConstructor<AdhocWifiMac> ()

  ;

  return tid;

}

AdhocWifiMac::AdhocWifiMac ()

{

  NS_LOG_FUNCTION (this);

  //Let the lower layers know that we are acting in an IBSS

  SetTypeOfStation (ADHOC_STA);

}

AdhocWifiMac::~AdhocWifiMac ()

{

  NS_LOG_FUNCTION (this);

}

void

AdhocWifiMac::SetAddress (Mac48Address address)

{

  NS_LOG_FUNCTION (this << address);

  //In an IBSS, the BSSID is supposed to be generated per Section

  //11.1.3 of IEEE 802.11. We don't currently do this - instead we

  //make an IBSS STA a bit like an AP, with the BSSID for frames

  //transmitted by each STA set to that STA's address.

  //

  //This is why we're overriding this method.

  RegularWifiMac::SetAddress (address);

  RegularWifiMac::SetBssid (address);

}

void

AdhocWifiMac::Enqueue (Ptr<const Packet> packet, Mac48Address to)

{

  NS_LOG_FUNCTION (this << packet << to);

  if (m_stationManager->IsBrandNew (to))

    {

      //In ad hoc mode, we assume that every destination supports all

      //the rates we support.

      m_stationManager->AddAllSupportedModes (to);

      m_stationManager->RecordDisassociated (to);

    }

  WifiMacHeader hdr;

  //If we are not a QoS STA then we definitely want to use AC_BE to

  //transmit the packet. A TID of zero will map to AC_BE (through \c

  //QosUtilsMapTidToAc()), so we use that as our default here.

  uint8_t tid = 0;

  //For now, a STA that supports QoS does not support non-QoS

  //associations, and vice versa. In future the STA model should fall

  //back to non-QoS if talking to a peer that is also non-QoS. At

  //that point there will need to be per-station QoS state maintained

  //by the association state machine, and consulted here.

  if (m_qosSupported)

    {

      hdr.SetType (WIFI_MAC_QOSDATA);

      hdr.SetQosAckPolicy (WifiMacHeader::NORMAL_ACK);

      hdr.SetQosNoEosp ();

      hdr.SetQosNoAmsdu ();

      //Transmission of multiple frames in the same TXOP is not

      //supported for now

      hdr.SetQosTxopLimit (0);

      //Fill in the QoS control field in the MAC header

      tid = QosUtilsGetTidForPacket (packet);

      //Any value greater than 7 is invalid and likely indicates that

      //the packet had no QoS tag, so we revert to zero, which will

      //mean that AC_BE is used.

      if (tid > 7)

        {

          tid = 0;

        }

      hdr.SetQosTid (tid);

    }

  else

    {

      hdr.SetTypeData ();

    }

  hdr.SetAddr1 (to);

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

  hdr.SetAddr3 (GetBssid ());

  hdr.SetDsNotFrom ();

  hdr.SetDsNotTo ();

  if (m_qosSupported)

    {

      //Sanity check that the TID is valid

      NS_ASSERT (tid < 8);

      m_edca[QosUtilsMapTidToAc (tid)]->Queue (packet, hdr);

    }

  else

    {

      m_dca->Queue (packet, hdr);

    }

}

void

AdhocWifiMac::SetLinkUpCallback (Callback<void> linkUp)

{

  NS_LOG_FUNCTION (this << &linkUp);

  RegularWifiMac::SetLinkUpCallback (linkUp);

  //The approach taken here is that, from the point of view of a STA

  //in IBSS mode, the link is always up, so we immediately invoke the

  //callback if one is set

  linkUp ();

}

void

AdhocWifiMac::Receive (Ptr<Packet> packet, const WifiMacHeader *hdr)

{

  NS_LOG_FUNCTION (this << packet << hdr);

  NS_ASSERT (!hdr->IsCtl ());

  Mac48Address from = hdr->GetAddr2 ();

  Mac48Address to = hdr->GetAddr1 ();

  if (hdr->IsData ())

    {

      if (hdr->IsQosData () && hdr->IsQosAmsdu ())

        {

          NS_LOG_DEBUG ("Received A-MSDU from" << from);

          DeaggregateAmsduAndForward (packet, hdr);

        }

      else

        {

          ForwardUp (packet, from, to);

        }

      return;

    }

  //Invoke the receive handler of our parent class to deal with any

  //other frames. Specifically, this will handle Block Ack-related

  //Management Action frames.

  RegularWifiMac::Receive (packet, hdr);

}

} //namespace ns3