/*

 * Copyright (c) 2005,2006,2007 INRIA

 *

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

 */

#include "wifi-remote-station-manager.h"

#include "ns3/simulator.h"

#include "ns3/assert.h"

#include "ns3/log.h"

#include "ns3/tag.h"

#include "ns3/boolean.h"

#include "ns3/double.h"

#include "ns3/uinteger.h"

#include "ns3/wifi-phy.h"

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

#include "wifi-mac-header.h"

#include "wifi-mac-trailer.h"

NS_LOG_COMPONENT_DEFINE ("WifiRemoteStationManager");

/***************************************************************

 *           Packet Mode Tagger

 ***************************************************************/

namespace ns3 {

class TxModeTag : public Tag

{

public:

  TxModeTag ();

  TxModeTag (WifiMode rtsMode, WifiMode dataMode);

  WifiMode GetRtsMode (void) const;

  WifiMode GetDataMode (void) const;

  static TypeId GetTypeId (void);

  virtual TypeId GetInstanceTypeId (void) const;

  virtual uint32_t GetSerializedSize (void) const;

  virtual void Serialize (TagBuffer i) const;

  virtual void Deserialize (TagBuffer i);

  virtual void Print (std::ostream &os) const;

private:

  WifiMode m_rtsMode;

  WifiMode m_dataMode;

};

TxModeTag::TxModeTag ()

{

}

TxModeTag::TxModeTag (WifiMode rtsMode, WifiMode dataMode)

  : m_rtsMode (rtsMode),

    m_dataMode (dataMode)

{

}

WifiMode

TxModeTag::GetRtsMode (void) const

{

  return m_rtsMode;

}

WifiMode

TxModeTag::GetDataMode (void) const

{

  return m_dataMode;

}

TypeId

TxModeTag::GetTypeId (void)

{

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

    .SetParent<Tag> ()

    .AddConstructor<TxModeTag> ()

    .AddAttribute ("RtsTxMode",

                   "Tx mode of rts to use later",

                   EmptyAttributeValue (),

                   MakeWifiModeAccessor (&TxModeTag::GetRtsMode),

                   MakeWifiModeChecker ())

    .AddAttribute ("DataTxMode",

                   "Tx mode of data to use later",

                   EmptyAttributeValue (),

                   MakeWifiModeAccessor (&TxModeTag::GetDataMode),

                   MakeWifiModeChecker ())

  ;

  return tid;

}

TypeId

TxModeTag::GetInstanceTypeId (void) const

{

  return GetTypeId ();

}

uint32_t

TxModeTag::GetSerializedSize (void) const

{

  return sizeof (WifiMode) * 2;

}

void

TxModeTag::Serialize (TagBuffer i) const

{

  i.Write ((uint8_t *)&m_rtsMode, sizeof (WifiMode));

  i.Write ((uint8_t *)&m_dataMode, sizeof (WifiMode));

}

void

TxModeTag::Deserialize (TagBuffer i)

{

  i.Read ((uint8_t *)&m_rtsMode, sizeof (WifiMode));

  i.Read ((uint8_t *)&m_dataMode, sizeof (WifiMode));

}

void

TxModeTag::Print (std::ostream &os) const

{

  os << "Rts=" << m_rtsMode << ", Data=" << m_dataMode;

}

} // namespace ns3

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (WifiRemoteStationManager);

TypeId

WifiRemoteStationManager::GetTypeId (void)

{

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

    .SetParent<Object> ()

    .AddAttribute ("IsLowLatency", "If true, we attempt to modelize a so-called low-latency device: a device"

                   " where decisions about tx parameters can be made on a per-packet basis and feedback about the"

                   " transmission of each packet is obtained before sending the next. Otherwise, we modelize a "

                   " high-latency device, that is a device where we cannot update our decision about tx parameters"

                   " after every packet transmission.",

                   BooleanValue (true), // this value is ignored because there is no setter

                   MakeBooleanAccessor (&WifiRemoteStationManager::IsLowLatency),

                   MakeBooleanChecker ())

    .AddAttribute ("MaxSsrc", "The maximum number of retransmission attempts for an RTS. This value"

                   " will not have any effect on some rate control algorithms.",

                   UintegerValue (7),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_maxSsrc),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("MaxSlrc", "The maximum number of retransmission attempts for a DATA packet. This value"

                   " will not have any effect on some rate control algorithms.",

                   UintegerValue (7),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_maxSlrc),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("RtsCtsThreshold", "If  the size of the data packet + LLC header + MAC header + FCS trailer is bigger than "

                   "this value, we use an RTS/CTS handshake before sending the data, as per IEEE Std. 802.11-2007, Section 9.2.6. "

                   "This value will not have any effect on some rate control algorithms.",

                   UintegerValue (2346),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_rtsCtsThreshold),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("FragmentationThreshold", "If the size of the data packet + LLC header + MAC header + FCS trailer is bigger"

                   "than this value, we fragment it such that the size of the fragments are equal or smaller "

                   "than this value, as per IEEE Std. 802.11-2007, Section 9.4. "

                   "This value will not have any effect on some rate control algorithms.",

                   UintegerValue (2346),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_fragmentationThreshold),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("NonUnicastMode", "Wifi mode used for non-unicast transmissions.",

                   WifiModeValue (),

                   MakeWifiModeAccessor (&WifiRemoteStationManager::m_nonUnicastMode),

                   MakeWifiModeChecker ())

    .AddTraceSource ("MacTxRtsFailed",

                     "The transmission of a RTS by the MAC layer has failed",

                     MakeTraceSourceAccessor (&WifiRemoteStationManager::m_macTxRtsFailed))

    .AddTraceSource ("MacTxDataFailed",

                     "The transmission of a data packet by the MAC layer has failed",

                     MakeTraceSourceAccessor (&WifiRemoteStationManager::m_macTxDataFailed))

    .AddTraceSource ("MacTxFinalRtsFailed",

                     "The transmission of a RTS has exceeded the maximum number of attempts",

                     MakeTraceSourceAccessor (&WifiRemoteStationManager::m_macTxFinalRtsFailed))

    .AddTraceSource ("MacTxFinalDataFailed",

                     "The transmission of a data packet has exceeded the maximum number of attempts",

                     MakeTraceSourceAccessor (&WifiRemoteStationManager::m_macTxFinalDataFailed))

  ;

  return tid;

}

WifiRemoteStationManager::WifiRemoteStationManager ()

{

}

WifiRemoteStationManager::~WifiRemoteStationManager ()

{

}

void

WifiRemoteStationManager::DoDispose (void)

{

  for (StationStates::const_iterator i = m_states.begin (); i != m_states.end (); i++)

    {

      delete (*i);

    }

  m_states.clear ();

  for (Stations::const_iterator i = m_stations.begin (); i != m_stations.end (); i++)

    {

      delete (*i);

    }

  m_stations.clear ();

}

void

WifiRemoteStationManager::SetupPhy (Ptr<WifiPhy> phy)

{

  // We need to track our PHY because it is the object that knows the

  // full set of transmit rates that are supported. We need to know

  // this in order to find the relevant mandatory rates when chosing a

  // transmit rate for automatic control responses like

  // acknowledgements.

  m_wifiPhy = phy;

  m_defaultTxMode = phy->GetMode (0);

  Reset ();

}

uint32_t

WifiRemoteStationManager::GetMaxSsrc (void) const

{

  return m_maxSsrc;

}

uint32_t

WifiRemoteStationManager::GetMaxSlrc (void) const

{

  return m_maxSlrc;

}

uint32_t

WifiRemoteStationManager::GetRtsCtsThreshold (void) const

{

  return m_rtsCtsThreshold;

}

uint32_t

WifiRemoteStationManager::GetFragmentationThreshold (void) const

{

  return m_fragmentationThreshold;

}

void

WifiRemoteStationManager::SetMaxSsrc (uint32_t maxSsrc)

{

  m_maxSsrc = maxSsrc;

}

void

WifiRemoteStationManager::SetMaxSlrc (uint32_t maxSlrc)

{

  m_maxSlrc = maxSlrc;

}

void

WifiRemoteStationManager::SetRtsCtsThreshold (uint32_t threshold)

{

  m_rtsCtsThreshold = threshold;

}

void

WifiRemoteStationManager::SetFragmentationThreshold (uint32_t threshold)

{

  m_fragmentationThreshold = threshold;

}

void

WifiRemoteStationManager::Reset (Mac48Address address)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStationState *state = LookupState (address);

  state->m_operationalRateSet.clear ();

  AddSupportedMode (address, GetDefaultMode ());

}

void

WifiRemoteStationManager::AddSupportedMode (Mac48Address address, WifiMode mode)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStationState *state = LookupState (address);

  for (WifiModeListIterator i = state->m_operationalRateSet.begin (); i != state->m_operationalRateSet.end (); i++)

    {

      if ((*i) == mode)

        {

          // already in.

          return;

        }

    }

  state->m_operationalRateSet.push_back (mode);

}

bool

WifiRemoteStationManager::IsBrandNew (Mac48Address address) const

{

  if (address.IsGroup ())

    {

      return false;

    }

  return LookupState (address)->m_state == WifiRemoteStationState::BRAND_NEW;

}

bool

WifiRemoteStationManager::IsAssociated (Mac48Address address) const

{

  if (address.IsGroup ())

    {

      return true;

    }

  return LookupState (address)->m_state == WifiRemoteStationState::GOT_ASSOC_TX_OK;

}

bool

WifiRemoteStationManager::IsWaitAssocTxOk (Mac48Address address) const

{

  if (address.IsGroup ())

    {

      return false;

    }

  return LookupState (address)->m_state == WifiRemoteStationState::WAIT_ASSOC_TX_OK;

}

void

WifiRemoteStationManager::RecordWaitAssocTxOk (Mac48Address address)

{

  NS_ASSERT (!address.IsGroup ());

  LookupState (address)->m_state = WifiRemoteStationState::WAIT_ASSOC_TX_OK;

}

void

WifiRemoteStationManager::RecordGotAssocTxOk (Mac48Address address)

{

  NS_ASSERT (!address.IsGroup ());

  LookupState (address)->m_state = WifiRemoteStationState::GOT_ASSOC_TX_OK;

}

void

WifiRemoteStationManager::RecordGotAssocTxFailed (Mac48Address address)

{

  NS_ASSERT (!address.IsGroup ());

  LookupState (address)->m_state = WifiRemoteStationState::DISASSOC;

}

void

WifiRemoteStationManager::RecordDisassociated (Mac48Address address)

{

  NS_ASSERT (!address.IsGroup ());

  LookupState (address)->m_state = WifiRemoteStationState::DISASSOC;

}

void

WifiRemoteStationManager::PrepareForQueue (Mac48Address address, const WifiMacHeader *header,

                                           Ptr<const Packet> packet, uint32_t fullPacketSize)

{

  if (IsLowLatency () || address.IsGroup ())

    {

      return;

    }

  WifiRemoteStation *station = Lookup (address, header);

  WifiMode rts = DoGetRtsMode (station);

  WifiMode data = DoGetDataMode (station, fullPacketSize);

  TxModeTag tag;

  // first, make sure that the tag is not here anymore.

  ConstCast<Packet> (packet)->RemovePacketTag (tag);

  tag = TxModeTag (rts, data);

  // and then, add it back

  packet->AddPacketTag (tag);

}

WifiMode

WifiRemoteStationManager::GetDataMode (Mac48Address address, const WifiMacHeader *header,

                                       Ptr<const Packet> packet, uint32_t fullPacketSize)

{

  if (address.IsGroup ())

    {

      return GetNonUnicastMode ();

    }

  if (!IsLowLatency ())

    {

      TxModeTag tag;

      bool found;

      found = ConstCast<Packet> (packet)->PeekPacketTag (tag);

      NS_ASSERT (found);

      // cast found to void, to suppress 'found' set but not used

      // compiler warning

      (void) found;

      return tag.GetDataMode ();

    }

  return DoGetDataMode (Lookup (address, header), fullPacketSize);

}

WifiMode

WifiRemoteStationManager::GetRtsMode (Mac48Address address, const WifiMacHeader *header,

                                      Ptr<const Packet> packet)

{

  NS_ASSERT (!address.IsGroup ());

  if (!IsLowLatency ())

    {

      TxModeTag tag;

      bool found;

      found = ConstCast<Packet> (packet)->PeekPacketTag (tag);

      NS_ASSERT (found);

      // cast found to void, to suppress 'found' set but not used

      // compiler warning

      (void) found;

      return tag.GetRtsMode ();

    }

  return DoGetRtsMode (Lookup (address, header));

}

void

WifiRemoteStationManager::ReportRtsFailed (Mac48Address address, const WifiMacHeader *header)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_ssrc++;

  m_macTxRtsFailed (address);

  DoReportRtsFailed (station);

}

void

WifiRemoteStationManager::ReportDataFailed (Mac48Address address, const WifiMacHeader *header)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_slrc++;

  m_macTxDataFailed (address);

  DoReportDataFailed (station);

}

void

WifiRemoteStationManager::ReportRtsOk (Mac48Address address, const WifiMacHeader *header,

                                       double ctsSnr, WifiMode ctsMode, double rtsSnr)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_state->m_info.NotifyTxSuccess (station->m_ssrc);

  station->m_ssrc = 0;

  DoReportRtsOk (station, ctsSnr, ctsMode, rtsSnr);

}

void

WifiRemoteStationManager::ReportDataOk (Mac48Address address, const WifiMacHeader *header,

                                        double ackSnr, WifiMode ackMode, double dataSnr)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_state->m_info.NotifyTxSuccess (station->m_slrc);

  station->m_slrc = 0;

  DoReportDataOk (station, ackSnr, ackMode, dataSnr);

}

void

WifiRemoteStationManager::ReportFinalRtsFailed (Mac48Address address, const WifiMacHeader *header)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_state->m_info.NotifyTxFailed ();

  station->m_ssrc = 0;

  m_macTxFinalRtsFailed (address);

  DoReportFinalRtsFailed (station);

}

void

WifiRemoteStationManager::ReportFinalDataFailed (Mac48Address address, const WifiMacHeader *header)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  station->m_state->m_info.NotifyTxFailed ();

  station->m_slrc = 0;

  m_macTxFinalDataFailed (address);

  DoReportFinalDataFailed (station);

}

void

WifiRemoteStationManager::ReportRxOk (Mac48Address address, const WifiMacHeader *header,

                                      double rxSnr, WifiMode txMode)

{

  if (address.IsGroup ())

    {

      return;

    }

  WifiRemoteStation *station = Lookup (address, header);

  DoReportRxOk (station, rxSnr, txMode);

}

bool

WifiRemoteStationManager::NeedRts (Mac48Address address, const WifiMacHeader *header,

                                   Ptr<const Packet> packet)

{

  if (address.IsGroup ())

    {

      return false;

    }

  bool normally = (packet->GetSize () + header->GetSize () + WIFI_MAC_FCS_LENGTH) > GetRtsCtsThreshold ();

  return DoNeedRts (Lookup (address, header), packet, normally);

}

bool

WifiRemoteStationManager::NeedRtsRetransmission (Mac48Address address, const WifiMacHeader *header,

                                                 Ptr<const Packet> packet)

{

  NS_ASSERT (!address.IsGroup ());

  WifiRemoteStation *station = Lookup (address, header);

  bool normally = station->m_ssrc < GetMaxSsrc ();

  return DoNeedRtsRetransmission (station, packet, normally);

}

bool