/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006 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 "ns3/packet.h"
#include "ns3/simulator.h"
#include "ns3/assert.h"
#include "ns3/log.h"
#include "ns3/node.h"
#include "ns3/uinteger.h"
#include "nqsta-wifi-mac.h"
#include "wifi-mac-header.h"
#include "mgt-headers.h"
#include "wifi-phy.h"
#include "dca-txop.h"
#include "mac-low.h"
#include "dcf-manager.h"
#include "mac-rx-middle.h"
NS_LOG_COMPONENT_DEFINE ("NqstaWifiMac");
/*
* The state machine for this NQSTA is:
-------------- -----------
| Associated | <-------------------- -------> | Refused |
-------------- \ / -----------
\ \ /
\ ----------------- -----------------------------
\-> | Beacon Missed | --> | Wait Association Response |
----------------- -----------------------------
\ ^
\ |
\ -----------------------
\-> | Wait Probe Response |
-----------------------
*/
namespace ns3 {
NS_OBJECT_ENSURE_REGISTERED (NqstaWifiMac);
TypeId
NqstaWifiMac::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::NqstaWifiMac")
.SetParent<WifiMac> ()
.AddConstructor<NqstaWifiMac> ()
.AddAttribute ("ProbeRequestTimeout", "XXX",
TimeValue (Seconds (0.5)),
MakeTimeAccessor (&NqstaWifiMac::m_probeRequestTimeout),
MakeTimeChecker ())
.AddAttribute ("AssocRequestTimeout", "XXX",
TimeValue (Seconds (0.5)),
MakeTimeAccessor (&NqstaWifiMac::m_assocRequestTimeout),
MakeTimeChecker ())
.AddAttribute ("MaxMissedBeacons",
"Number of beacons which much be consecutively missed before "
"we attempt to restart association.",
UintegerValue (10),
MakeUintegerAccessor (&NqstaWifiMac::m_maxMissedBeacons),
MakeUintegerChecker<uint32_t> ())
.AddAttribute ("ActiveProbing", "XXX",
BooleanValue (false),
MakeBooleanAccessor (&NqstaWifiMac::SetActiveProbing),
MakeBooleanChecker ())
;
return tid;
}
NqstaWifiMac::NqstaWifiMac ()
: m_state (BEACON_MISSED),
m_probeRequestEvent (),
m_assocRequestEvent (),
m_beaconWatchdogEnd (Seconds (0.0))
{
NS_LOG_FUNCTION (this);
m_rxMiddle = new MacRxMiddle ();
m_rxMiddle->SetForwardCallback (MakeCallback (&NqstaWifiMac::Receive, this));
m_low = CreateObject<MacLow> ();
m_low->SetRxCallback (MakeCallback (&MacRxMiddle::Receive, m_rxMiddle));
m_low->SetMac (this);
m_dcfManager = new DcfManager ();
m_dcfManager->SetupLowListener (m_low);
m_dca = CreateObject<DcaTxop> ();
m_dca->SetLow (m_low);
m_dca->SetManager (m_dcfManager);
}
NqstaWifiMac::~NqstaWifiMac ()
{
NS_LOG_FUNCTION (this);
}
void
NqstaWifiMac::DoDispose (void)
{
NS_LOG_FUNCTION (this);
delete m_rxMiddle;
delete m_dcfManager;
m_rxMiddle = 0;
m_low = 0;
m_dcfManager = 0;
m_phy = 0;
m_dca = 0;
WifiMac::DoDispose ();
}
void
NqstaWifiMac::SetSlot (Time slotTime)
{
NS_LOG_FUNCTION (this << slotTime);
m_dcfManager->SetSlot (slotTime);
m_slot = slotTime;
}
void
NqstaWifiMac::SetSifs (Time sifs)
{
NS_LOG_FUNCTION (this << sifs);
m_dcfManager->SetSifs (sifs);
m_sifs = sifs;
}
void
NqstaWifiMac::SetEifsNoDifs (Time eifsNoDifs)
{
NS_LOG_FUNCTION (this << eifsNoDifs);
m_dcfManager->SetEifsNoDifs (eifsNoDifs);
m_eifsNoDifs = eifsNoDifs;
}
Time
NqstaWifiMac::GetSlot (void) const
{
return m_slot;
}
Time
NqstaWifiMac::GetSifs (void) const
{
return m_sifs;
}
Time
NqstaWifiMac::GetEifsNoDifs (void) const
{
return m_eifsNoDifs;
}
void
NqstaWifiMac::SetWifiPhy (Ptr<WifiPhy> phy)
{
m_phy = phy;
m_dcfManager->SetupPhyListener (phy);
m_low->SetPhy (phy);
}
void
NqstaWifiMac::SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> stationManager)
{
m_stationManager = stationManager;
m_dca->SetWifiRemoteStationManager (stationManager);
m_low->SetWifiRemoteStationManager (stationManager);
}
void
NqstaWifiMac::SetForwardUpCallback (Callback<void,Ptr<Packet>, const Mac48Address &> upCallback)
{
m_forwardUp = upCallback;
}
void
NqstaWifiMac::SetLinkUpCallback (Callback<void> linkUp)
{
m_linkUp = linkUp;
}
void
NqstaWifiMac::SetLinkDownCallback (Callback<void> linkDown)
{
m_linkDown = linkDown;
}
Mac48Address
NqstaWifiMac::GetAddress (void) const
{
return m_address;
}
Ssid
NqstaWifiMac::GetSsid (void) const
{
return m_ssid;
}
Mac48Address
NqstaWifiMac::GetBssid (void) const
{
return m_bssid;
}
void
NqstaWifiMac::SetAddress (Mac48Address address)
{
NS_LOG_FUNCTION (this << address);
m_address = address;
}
void
NqstaWifiMac::SetSsid (Ssid ssid)
{
NS_LOG_FUNCTION (this << ssid);
m_ssid = ssid;
}
void
NqstaWifiMac::SetMaxMissedBeacons (uint32_t missed)
{
NS_LOG_FUNCTION (this << missed);
m_maxMissedBeacons = missed;
}
void
NqstaWifiMac::SetProbeRequestTimeout (Time timeout)
{
NS_LOG_FUNCTION (this << timeout);
m_probeRequestTimeout = timeout;
}
void
NqstaWifiMac::SetAssocRequestTimeout (Time timeout)
{
NS_LOG_FUNCTION (this << timeout);
m_assocRequestTimeout = timeout;
}
void
NqstaWifiMac::StartActiveAssociation (void)
{
NS_LOG_FUNCTION (this);
TryToEnsureAssociated ();
}
Mac48Address
NqstaWifiMac::GetBroadcastBssid (void)
{
return Mac48Address::GetBroadcast ();
}
void
NqstaWifiMac::SetBssid (Mac48Address bssid)
{
NS_LOG_FUNCTION (this << bssid);
m_bssid = bssid;
}
void
NqstaWifiMac::SetActiveProbing (bool enable)
{
NS_LOG_FUNCTION (this << enable);
if (enable)
{
TryToEnsureAssociated ();
}
else
{
m_probeRequestEvent.Cancel ();
}
}
void
NqstaWifiMac::ForwardUp (Ptr<Packet> packet, const Mac48Address &address)
{
NS_LOG_FUNCTION (this << packet << address);
m_forwardUp (packet, address);
}
void
NqstaWifiMac::SendProbeRequest (void)
{
NS_LOG_FUNCTION (this);
WifiMacHeader hdr;
hdr.SetProbeReq ();
hdr.SetAddr1 (GetBroadcastBssid ());
hdr.SetAddr2 (GetAddress ());
hdr.SetAddr3 (GetBroadcastBssid ());
hdr.SetDsNotFrom ();
hdr.SetDsNotTo ();
Ptr<Packet> packet = Create<Packet> ();
MgtProbeRequestHeader probe;
probe.SetSsid (GetSsid ());
probe.SetSupportedRates (GetSupportedRates ());
packet->AddHeader (probe);
m_dca->Queue (packet, hdr);
m_probeRequestEvent = Simulator::Schedule (m_probeRequestTimeout,
&NqstaWifiMac::ProbeRequestTimeout, this);
}
void
NqstaWifiMac::SendAssociationRequest (void)
{
NS_LOG_FUNCTION (this << GetBssid ());
WifiMacHeader hdr;
hdr.SetAssocReq ();
hdr.SetAddr1 (GetBssid ());
hdr.SetAddr2 (GetAddress ());
hdr.SetAddr3 (GetBssid ());
hdr.SetDsNotFrom ();
hdr.SetDsNotTo ();
Ptr<Packet> packet = Create<Packet> ();
MgtAssocRequestHeader assoc;
assoc.SetSsid (GetSsid ());
assoc.SetSupportedRates (GetSupportedRates ());
packet->AddHeader (assoc);
m_dca->Queue (packet, hdr);
m_assocRequestEvent = Simulator::Schedule (m_assocRequestTimeout,
&NqstaWifiMac::AssocRequestTimeout, this);
}
void
NqstaWifiMac::TryToEnsureAssociated (void)
{
NS_LOG_FUNCTION (this);
switch (m_state) {
case ASSOCIATED:
return;
break;
case WAIT_PROBE_RESP:
/* we have sent a probe request earlier so we
do not need to re-send a probe request immediately.
We just need to wait until probe-request-timeout
or until we get a probe response
*/
break;
case BEACON_MISSED:
/* we were associated but we missed a bunch of beacons
* so we should assume we are not associated anymore.
* We try to initiate a probe request now.
*/
m_linkDown ();
m_state = WAIT_PROBE_RESP;
SendProbeRequest ();
break;
case WAIT_ASSOC_RESP:
/* we have sent an assoc request so we do not need to
re-send an assoc request right now. We just need to
wait until either assoc-request-timeout or until
we get an assoc response.
*/
break;
case REFUSED:
/* we have sent an assoc request and received a negative
assoc resp. We wait until someone restarts an
association with a given ssid.
*/
break;
}
}
void
NqstaWifiMac::AssocRequestTimeout (void)
{
NS_LOG_FUNCTION (this);
m_state = WAIT_ASSOC_RESP;
SendAssociationRequest ();
}
void
NqstaWifiMac::ProbeRequestTimeout (void)
{
NS_LOG_FUNCTION (this);
m_state = WAIT_PROBE_RESP;
SendProbeRequest ();
}
void
NqstaWifiMac::MissedBeacons (void)
{
NS_LOG_FUNCTION (this);
if (m_beaconWatchdogEnd > Simulator::Now ())
{
m_beaconWatchdog = Simulator::Schedule (m_beaconWatchdogEnd - Simulator::Now (),
&NqstaWifiMac::MissedBeacons, this);
return;
}
NS_LOG_DEBUG ("beacon missed");
m_state = BEACON_MISSED;
TryToEnsureAssociated ();
}
void
NqstaWifiMac::RestartBeaconWatchdog (Time delay)
{
NS_LOG_FUNCTION (this << delay);
m_beaconWatchdogEnd = std::max (Simulator::Now () + delay, m_beaconWatchdogEnd);
if (Simulator::GetDelayLeft (m_beaconWatchdog) < delay &&
m_beaconWatchdog.IsExpired ())
{
NS_LOG_DEBUG ("really restart watchdog.");
m_beaconWatchdog = Simulator::Schedule (delay, &NqstaWifiMac::MissedBeacons, this);
}
}
bool
NqstaWifiMac::IsAssociated (void)
{
return (m_state == ASSOCIATED)?true:false;
}
void
NqstaWifiMac::Enqueue (Ptr<const Packet> packet, Mac48Address to)
{
NS_LOG_FUNCTION (this << packet << to);
if (!IsAssociated ())
{
TryToEnsureAssociated ();
return;
}
//NS_LOG_DEBUG ("enqueue size="<<packet->GetSize ()<<", to="<<to);
WifiMacHeader hdr;
hdr.SetTypeData ();
hdr.SetAddr1 (GetBssid ());
hdr.SetAddr2 (GetAddress ());
hdr.SetAddr3 (to);
hdr.SetDsNotFrom ();
hdr.SetDsTo ();
m_dca->Queue (packet, hdr);
}
void
NqstaWifiMac::Receive (Ptr<Packet> packet, WifiMacHeader const *hdr)
{
NS_LOG_FUNCTION (this << packet << hdr);
NS_ASSERT (!hdr->IsCtl ());
if (hdr->GetAddr1 () != GetAddress () &&
!hdr->GetAddr1 ().IsBroadcast ())
{
// packet is not for us
}
else if (hdr->IsData ())
{
ForwardUp (packet, hdr->GetAddr2 ());
}
else if (hdr->IsProbeReq () ||
hdr->IsAssocReq ())
{
/* this is a frame aimed at an AP.
* so we can safely ignore it.
*/
}
else if (hdr->IsBeacon ())
{
MgtBeaconHeader beacon;
packet->RemoveHeader (beacon);
bool goodBeacon = false;
if (GetSsid ().IsBroadcast () ||
beacon.GetSsid ().IsEqual (GetSsid ()))
{
Time delay = MicroSeconds (beacon.GetBeaconIntervalUs () * m_maxMissedBeacons);
RestartBeaconWatchdog (delay);
goodBeacon = true;
}
if (goodBeacon)
{
SetBssid (hdr->GetAddr3 ());
}
if (goodBeacon && m_state == BEACON_MISSED)
{
m_state = WAIT_ASSOC_RESP;
SendAssociationRequest ();
}
}
else if (hdr->IsProbeResp ())
{
if (m_state == WAIT_PROBE_RESP)
{
MgtProbeResponseHeader probeResp;
packet->RemoveHeader (probeResp);
if (!probeResp.GetSsid ().IsEqual (GetSsid ()))
{
//not a probe resp for our ssid.
return;
}
SetBssid (hdr->GetAddr3 ());
Time delay = MicroSeconds (probeResp.GetBeaconIntervalUs () * m_maxMissedBeacons);
RestartBeaconWatchdog (delay);
if (m_probeRequestEvent.IsRunning ())
{
m_probeRequestEvent.Cancel ();
}
m_state = WAIT_ASSOC_RESP;
SendAssociationRequest ();
}
}
else if (hdr->IsAssocResp ())
{
if (m_state == WAIT_ASSOC_RESP)
{
MgtAssocResponseHeader assocResp;
packet->RemoveHeader (assocResp);
if (m_assocRequestEvent.IsRunning ())
{
m_assocRequestEvent.Cancel ();
}
if (assocResp.GetStatusCode ().IsSuccess ())
{
m_state = ASSOCIATED;
NS_LOG_DEBUG ("assoc completed");
SupportedRates rates = assocResp.GetSupportedRates ();
WifiRemoteStation *ap = m_stationManager->Lookup (hdr->GetAddr2 ());
for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
{
WifiMode mode = m_phy->GetMode (i);
if (rates.IsSupportedRate (mode.GetDataRate ()))
{
ap->AddSupportedMode (mode);
if (rates.IsBasicRate (mode.GetDataRate ()))
{
m_stationManager->AddBasicMode (mode);
}
}
}
if (!m_linkUp.IsNull ())
{
m_linkUp ();
}
}
else
{
NS_LOG_DEBUG ("assoc refused");
m_state = REFUSED;
}
}
}
}
SupportedRates
NqstaWifiMac::GetSupportedRates (void) const
{
SupportedRates rates;
for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
{
WifiMode mode = m_phy->GetMode (i);
rates.AddSupportedRate (mode.GetDataRate ());
}
return rates;
}
} // namespace ns3