/*

 * 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

 *

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

 */

#include "ns3/log.h"

#include "ns3/uinteger.h"

#include "amsdu-subframe-header.h"

#include "msdu-standard-aggregator.h"

NS_LOG_COMPONENT_DEFINE ("MsduStandardAggregator");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (MsduStandardAggregator);

TypeId

MsduStandardAggregator::GetTypeId (void)

{

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

    .SetParent<MsduAggregator> ()

    .AddConstructor<MsduStandardAggregator> ()

    .AddAttribute ("MaxAmsduSize", "Max length in byte of an A-MSDU",

                   UintegerValue (7935),

                   MakeUintegerAccessor (&MsduStandardAggregator::m_maxAmsduLength),

                   MakeUintegerChecker<uint32_t> ())

  ;

  return tid;

}

MsduStandardAggregator::MsduStandardAggregator ()

{

}

MsduStandardAggregator::~MsduStandardAggregator ()

{

}

bool

MsduStandardAggregator::Aggregate (Ptr<const Packet> packet, Ptr<Packet> aggregatedPacket,

                                   Mac48Address src, Mac48Address dest)

{

  NS_LOG_FUNCTION (this);

  Ptr<Packet> currentPacket;

  AmsduSubframeHeader currentHdr;

  uint32_t padding = CalculatePadding (aggregatedPacket);

  uint32_t actualSize = aggregatedPacket->GetSize ();

  if ((14 + packet->GetSize () + actualSize + padding) <= m_maxAmsduLength)

    {

      if (padding)

        {

          Ptr<Packet> pad = Create<Packet> (padding);

          aggregatedPacket->AddAtEnd (pad);

        }

      currentHdr.SetDestinationAddr (dest);

      currentHdr.SetSourceAddr (src);

      currentHdr.SetLength (packet->GetSize ());

      currentPacket = packet->Copy ();

      currentPacket->AddHeader (currentHdr);

      aggregatedPacket->AddAtEnd (currentPacket);

      return true;

    }

  return false;

}

uint32_t

MsduStandardAggregator::CalculatePadding (Ptr<const Packet> packet)

{

  return (4 - (packet->GetSize () % 4 )) % 4;

}

}  //namespace ns3