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

/*

 * 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>

 * Author: Cecchi Niccolò <insa@igeek.it>

 */

#include "qos-utils.h"

#include "qos-tag.h"

namespace ns3 {

AcIndex

QosUtilsMapTidToAc (uint8_t tid)

{

  switch (tid)

    {

    case 0:

      return AC_BE;

      break;

    case 1:

      return AC_BK;

      break;

    case 2:

      return AC_BK;

      break;

    case 3:

      return AC_BE;

      break;

    case 4:

      return AC_VI;

      break;

    case 5:

      return AC_VI;

      break;

    case 6:

      return AC_VO;

      break;

    case 7:

      return AC_VO;

      break;

    }

  return AC_UNDEF;

}

uint8_t

QosUtilsGetTidForPacket (Ptr<const Packet> packet)

{

  QosTag qos;

  uint8_t tid = 8;

  if (packet->PeekPacketTag (qos))

    {

      if (qos.GetTid () < 8)

        {

          tid = qos.GetTid ();

        }

    }

  return tid;

}

uint32_t

QosUtilsMapSeqControlToUniqueInteger (uint16_t seqControl, uint16_t endSequence)

{

  uint32_t integer = 0;

  uint16_t numberSeq = (seqControl >> 4) & 0x0fff;

  integer = (4096 - (endSequence + 1) + numberSeq) % 4096;

  integer *= 16;

  integer += (seqControl & 0x000f);

  return integer;

}

bool

QosUtilsIsOldPacket (uint16_t startingSeq, uint16_t seqNumber)

{

  NS_ASSERT (startingSeq < 4096);

  NS_ASSERT (seqNumber < 4096);

  uint16_t distance = ((seqNumber - startingSeq) + 4096) % 4096;

  return (distance >= 2048);

}

} // namespace ns3