/* -*- 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 "sta-wifi-mac.h"
#include "ns3/log.h"
#include "ns3/simulator.h"
#include "ns3/string.h"
#include "ns3/pointer.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 "wifi-mac-header.h"
#include "msdu-aggregator.h"
#include "amsdu-subframe-header.h"
#include "mgt-headers.h"
#include "ht-capabilities.h"
#include "vht-capabilities.h"
/*
* The state machine for this STA is:
-------------- -----------
| Associated | <-------------------- -------> | Refused |
-------------- \ / -----------
\ \ /
\ ----------------- -----------------------------
\-> | Beacon Missed | --> | Wait Association Response |
----------------- -----------------------------
\ ^
\ |
\ -----------------------
\-> | Wait Probe Response |
-----------------------
*/
namespace ns3 {
NS_LOG_COMPONENT_DEFINE ("StaWifiMac");
NS_OBJECT_ENSURE_REGISTERED (StaWifiMac);
TypeId
StaWifiMac::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::StaWifiMac")
.SetParent<RegularWifiMac> ()
.SetGroupName ("Wifi")
.AddConstructor<StaWifiMac> ()
.AddAttribute ("ProbeRequestTimeout", "The interval between two consecutive probe request attempts.",
TimeValue (Seconds (0.05)),
MakeTimeAccessor (&StaWifiMac::m_probeRequestTimeout),
MakeTimeChecker ())
.AddAttribute ("AssocRequestTimeout", "The interval between two consecutive assoc request attempts.",
TimeValue (Seconds (0.5)),
MakeTimeAccessor (&StaWifiMac::m_assocRequestTimeout),
MakeTimeChecker ())
.AddAttribute ("MaxMissedBeacons",
"Number of beacons which much be consecutively missed before "
"we attempt to restart association.",
UintegerValue (10),
MakeUintegerAccessor (&StaWifiMac::m_maxMissedBeacons),
MakeUintegerChecker<uint32_t> ())
.AddAttribute ("ActiveProbing",
"If true, we send probe requests. If false, we don't."
"NOTE: if more than one STA in your simulation is using active probing, "
"you should enable it at a different simulation time for each STA, "
"otherwise all the STAs will start sending probes at the same time resulting in collisions. "
"See bug 1060 for more info.",
BooleanValue (false),
MakeBooleanAccessor (&StaWifiMac::SetActiveProbing, &StaWifiMac::GetActiveProbing),
MakeBooleanChecker ())
.AddTraceSource ("Assoc", "Associated with an access point.",
MakeTraceSourceAccessor (&StaWifiMac::m_assocLogger),
"ns3::Mac48Address::TracedCallback")
.AddTraceSource ("DeAssoc", "Association with an access point lost.",
MakeTraceSourceAccessor (&StaWifiMac::m_deAssocLogger),
"ns3::Mac48Address::TracedCallback")
;
return tid;
}
StaWifiMac::StaWifiMac ()
: m_state (BEACON_MISSED),
m_probeRequestEvent (),
m_assocRequestEvent (),
m_beaconWatchdogEnd (Seconds (0.0))
{
NS_LOG_FUNCTION (this);
//Let the lower layers know that we are acting as a non-AP STA in
//an infrastructure BSS.
SetTypeOfStation (STA);
}
StaWifiMac::~StaWifiMac ()
{
NS_LOG_FUNCTION (this);
}
void
StaWifiMac::SetMaxMissedBeacons (uint32_t missed)
{
NS_LOG_FUNCTION (this << missed);
m_maxMissedBeacons = missed;
}
void
StaWifiMac::SetProbeRequestTimeout (Time timeout)
{
NS_LOG_FUNCTION (this << timeout);
m_probeRequestTimeout = timeout;
}
void
StaWifiMac::SetAssocRequestTimeout (Time timeout)
{
NS_LOG_FUNCTION (this << timeout);
m_assocRequestTimeout = timeout;
}
void
StaWifiMac::StartActiveAssociation (void)
{
NS_LOG_FUNCTION (this);
TryToEnsureAssociated ();
}
void
StaWifiMac::SetActiveProbing (bool enable)
{
NS_LOG_FUNCTION (this << enable);
if (enable)
{
Simulator::ScheduleNow (&StaWifiMac::TryToEnsureAssociated, this);
}
else
{
m_probeRequestEvent.Cancel ();
}
m_activeProbing = enable;
}
bool StaWifiMac::GetActiveProbing (void) const
{
return m_activeProbing;
}
void
StaWifiMac::SendProbeRequest (void)
{
NS_LOG_FUNCTION (this);
WifiMacHeader hdr;
hdr.SetProbeReq ();
hdr.SetAddr1 (Mac48Address::GetBroadcast ());
hdr.SetAddr2 (GetAddress ());
hdr.SetAddr3 (Mac48Address::GetBroadcast ());
hdr.SetDsNotFrom ();
hdr.SetDsNotTo ();
Ptr<Packet> packet = Create<Packet> ();
MgtProbeRequestHeader probe;
probe.SetSsid (GetSsid ());
probe.SetSupportedRates (GetSupportedRates ());
if (m_htSupported || m_vhtSupported)
{
probe.SetHtCapabilities (GetHtCapabilities ());
hdr.SetNoOrder ();
}
if (m_vhtSupported)
{
probe.SetVhtCapabilities (GetVhtCapabilities ());
}
packet->AddHeader (probe);
//The standard is not clear on the correct queue for management
//frames if we are a QoS AP. The approach taken here is to always
//use the DCF for these regardless of whether we have a QoS
//association or not.
m_dca->Queue (packet, hdr);
if (m_probeRequestEvent.IsRunning ())
{
m_probeRequestEvent.Cancel ();
}
m_probeRequestEvent = Simulator::Schedule (m_probeRequestTimeout,
&StaWifiMac::ProbeRequestTimeout, this);
}
void
StaWifiMac::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 ());
if (m_htSupported || m_vhtSupported)
{
assoc.SetHtCapabilities (GetHtCapabilities ());
hdr.SetNoOrder ();
}
if (m_vhtSupported)
{
assoc.SetVhtCapabilities (GetVhtCapabilities ());
}
packet->AddHeader (assoc);
//The standard is not clear on the correct queue for management
//frames if we are a QoS AP. The approach taken here is to always
//use the DCF for these regardless of whether we have a QoS
//association or not.
m_dca->Queue (packet, hdr);
if (m_assocRequestEvent.IsRunning ())
{
m_assocRequestEvent.Cancel ();
}
m_assocRequestEvent = Simulator::Schedule (m_assocRequestTimeout,
&StaWifiMac::AssocRequestTimeout, this);
}
void
StaWifiMac::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 ();
if (m_activeProbing)
{
SetState (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
StaWifiMac::AssocRequestTimeout (void)
{
NS_LOG_FUNCTION (this);
SetState (WAIT_ASSOC_RESP);
SendAssociationRequest ();
}
void
StaWifiMac::ProbeRequestTimeout (void)
{
NS_LOG_FUNCTION (this);
SetState (WAIT_PROBE_RESP);
SendProbeRequest ();
}
void
StaWifiMac::MissedBeacons (void)
{
NS_LOG_FUNCTION (this);
if (m_beaconWatchdogEnd > Simulator::Now ())
{
if (m_beaconWatchdog.IsRunning ())
{
m_beaconWatchdog.Cancel ();
}
m_beaconWatchdog = Simulator::Schedule (m_beaconWatchdogEnd - Simulator::Now (),
&StaWifiMac::MissedBeacons, this);
return;
}
NS_LOG_DEBUG ("beacon missed");
SetState (BEACON_MISSED);
TryToEnsureAssociated ();
}
void
StaWifiMac::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, &StaWifiMac::MissedBeacons, this);
}
}
bool
StaWifiMac::IsAssociated (void) const
{
return m_state == ASSOCIATED;
}
bool
StaWifiMac::IsWaitAssocResp (void) const
{
return m_state == WAIT_ASSOC_RESP;
}
void
StaWifiMac::Enqueue (Ptr<const Packet> packet, Mac48Address to)
{
NS_LOG_FUNCTION (this << packet << to);
if (!IsAssociated ())
{
NotifyTxDrop (packet);
TryToEnsureAssociated ();
return;
}
WifiMacHeader hdr;
//If we are not a QoS AP 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, an AP that supports QoS does not support non-QoS
//associations, and vice versa. In future the AP model should
//support simultaneously associated QoS and non-QoS STAs, at which
//point there will need to be per-association 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'll
//mean that AC_BE is used.
if (tid > 7)
{
tid = 0;
}
hdr.SetQosTid (tid);
}
else
{
hdr.SetTypeData ();
}
if (m_htSupported || m_vhtSupported)
{
hdr.SetNoOrder ();
}
hdr.SetAddr1 (GetBssid ());
hdr.SetAddr2 (m_low->GetAddress ());
hdr.SetAddr3 (to);
hdr.SetDsNotFrom ();
hdr.SetDsTo ();
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
StaWifiMac::Receive (Ptr<Packet> packet, const WifiMacHeader *hdr)
{
NS_LOG_FUNCTION (this << packet << hdr);
NS_ASSERT (!hdr->IsCtl ());
if (hdr->GetAddr3 () == GetAddress ())
{
NS_LOG_LOGIC ("packet sent by us.");
return;
}
else if (hdr->GetAddr1 () != GetAddress ()
&& !hdr->GetAddr1 ().IsGroup ())
{
NS_LOG_LOGIC ("packet is not for us");
NotifyRxDrop (packet);
return;
}
else if (hdr->IsData ())
{
if (!IsAssociated ())
{
NS_LOG_LOGIC ("Received data frame while not associated: ignore");
NotifyRxDrop (packet);
return;
}
if (!(hdr->IsFromDs () && !hdr->IsToDs ()))
{
NS_LOG_LOGIC ("Received data frame not from the DS: ignore");
NotifyRxDrop (packet);
return;
}
if (hdr->GetAddr2 () != GetBssid ())
{
NS_LOG_LOGIC ("Received data frame not from the BSS we are associated with: ignore");
NotifyRxDrop (packet);
return;
}
if (hdr->IsQosData ())
{
if (hdr->IsQosAmsdu ())
{
NS_ASSERT (hdr->GetAddr3 () == GetBssid ());
DeaggregateAmsduAndForward (packet, hdr);
packet = 0;
}
else
{
ForwardUp (packet, hdr->GetAddr3 (), hdr->GetAddr1 ());
}
}
else
{
ForwardUp (packet, hdr->GetAddr3 (), hdr->GetAddr1 ());
}
return;
}
else if (hdr->IsProbeReq ()
|| hdr->IsAssocReq ())
{
//This is a frame aimed at an AP, so we can safely ignore it.
NotifyRxDrop (packet);
return;
}
else if (hdr->IsBeacon ())
{
MgtBeaconHeader beacon;
packet->RemoveHeader (beacon);
bool goodBeacon = false;
if (GetSsid ().IsBroadcast ()
|| beacon.GetSsid ().IsEqual (GetSsid ()))
{
goodBeacon = true;
}
SupportedRates rates = beacon.GetSupportedRates ();
for (uint32_t i = 0; i < m_phy->GetNBssMembershipSelectors (); i++)
{
uint32_t selector = m_phy->GetBssMembershipSelector (i);
if (!rates.IsSupportedRate (selector))
{
goodBeacon = false;
}
}
if ((IsWaitAssocResp () || IsAssociated ()) && hdr->GetAddr3 () != GetBssid ())
{
goodBeacon = false;
}
if (goodBeacon)
{
Time delay = MicroSeconds (beacon.GetBeaconIntervalUs () * m_maxMissedBeacons);
RestartBeaconWatchdog (delay);
SetBssid (hdr->GetAddr3 ());
}
if (goodBeacon && m_state == BEACON_MISSED)
{
SetState (WAIT_ASSOC_RESP);
SendAssociationRequest ();
}
return;
}
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;
}
SupportedRates rates = probeResp.GetSupportedRates ();
for (uint32_t i = 0; i < m_phy->GetNBssMembershipSelectors (); i++)
{
uint32_t selector = m_phy->GetBssMembershipSelector (i);
if (!rates.IsSupportedRate (selector))
{
return;
}
}
SetBssid (hdr->GetAddr3 ());
Time delay = MicroSeconds (probeResp.GetBeaconIntervalUs () * m_maxMissedBeacons);
RestartBeaconWatchdog (delay);
if (m_probeRequestEvent.IsRunning ())
{
m_probeRequestEvent.Cancel ();
}
SetState (WAIT_ASSOC_RESP);
SendAssociationRequest ();
}
return;
}
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 ())
{
SetState (ASSOCIATED);
NS_LOG_DEBUG ("assoc completed");
SupportedRates rates = assocResp.GetSupportedRates ();
if (m_htSupported)
{
HtCapabilities htcapabilities = assocResp.GetHtCapabilities ();
m_stationManager->AddStationHtCapabilities (hdr->GetAddr2 (),htcapabilities);
}
if (m_vhtSupported)
{
VhtCapabilities vhtcapabilities = assocResp.GetVhtCapabilities ();
m_stationManager->AddStationVhtCapabilities (hdr->GetAddr2 (), vhtcapabilities);
}
for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
{
WifiMode mode = m_phy->GetMode (i);
if (rates.IsSupportedRate (mode.GetDataRate (m_phy->GetChannelWidth (), false, 1)))
{
m_stationManager->AddSupportedMode (hdr->GetAddr2 (), mode);
if (rates.IsBasicRate (mode.GetDataRate (m_phy->GetChannelWidth (), false, 1)))
{
m_stationManager->AddBasicMode (mode);
}
}
}
if (m_htSupported)
{
HtCapabilities htcapabilities = assocResp.GetHtCapabilities ();
for (uint32_t i = 0; i < m_phy->GetNMcs (); i++)
{
WifiMode mcs = m_phy->GetMcs (i);
if (mcs.GetModulationClass () == WIFI_MOD_CLASS_HT && htcapabilities.IsSupportedMcs (mcs.GetMcsValue ()))
{
m_stationManager->AddSupportedMcs (hdr->GetAddr2 (), mcs);
//here should add a control to add basic MCS when it is implemented
}
}
}
if (m_vhtSupported)
{
VhtCapabilities vhtcapabilities = assocResp.GetVhtCapabilities ();
for (uint32_t i = 0; i < m_phy->GetNMcs (); i++)
{
WifiMode mcs = m_phy->GetMcs (i);
if (mcs.GetModulationClass () == WIFI_MOD_CLASS_VHT && vhtcapabilities.IsSupportedTxMcs (mcs.GetMcsValue ()))
{
m_stationManager->AddSupportedMcs (hdr->GetAddr2 (), mcs);
//here should add a control to add basic MCS when it is implemented
}
}
}
if (!m_linkUp.IsNull ())
{
m_linkUp ();
}
}
else
{
NS_LOG_DEBUG ("assoc refused");
SetState (REFUSED);
}
}
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);
}
SupportedRates
StaWifiMac::GetSupportedRates (void) const
{
SupportedRates rates;
if (m_htSupported || m_vhtSupported)
{
for (uint32_t i = 0; i < m_phy->GetNBssMembershipSelectors (); i++)
{
rates.SetBasicRate (m_phy->GetBssMembershipSelector (i));
}
}
for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
{
WifiMode mode = m_phy->GetMode (i);
rates.AddSupportedRate (mode.GetDataRate (m_phy->GetChannelWidth (), false, 1));
}
return rates;
}
HtCapabilities
StaWifiMac::GetHtCapabilities (void) const
{
HtCapabilities capabilities;
capabilities.SetHtSupported (1);
if (m_htSupported)
{
capabilities.SetLdpc (m_phy->GetLdpc ());
capabilities.SetSupportedChannelWidth (m_phy->GetChannelWidth () == 40);
capabilities.SetShortGuardInterval20 (m_phy->GetGuardInterval ());
capabilities.SetShortGuardInterval40 (m_phy->GetChannelWidth () == 40 && m_phy->GetGuardInterval ());
capabilities.SetGreenfield (m_phy->GetGreenfield ());
capabilities.SetMaxAmsduLength (1); //hardcoded for now (TBD)
capabilities.SetLSigProtectionSupport (!m_phy->GetGreenfield ());
capabilities.SetMaxAmpduLength (3); //hardcoded for now (TBD)
uint64_t maxSupportedRate = 0; //in bit/s
for (uint8_t i = 0; i < m_phy->GetNMcs (); i++)
{
WifiMode mcs = m_phy->GetMcs (i);
capabilities.SetRxMcsBitmask (mcs.GetMcsValue ());
if (mcs.GetDataRate (m_phy->GetGuardInterval (), m_phy->GetGuardInterval (), 1) > maxSupportedRate)
{
maxSupportedRate = mcs.GetDataRate (m_phy->GetGuardInterval (), m_phy->GetGuardInterval (), 1);
}
}
capabilities.SetRxHighestSupportedDataRate (maxSupportedRate / 1e6); //in Mbit/s
capabilities.SetTxMcsSetDefined (m_phy->GetNMcs () > 0);
capabilities.SetTxMaxNSpatialStreams (m_phy->GetNumberOfTransmitAntennas ());
}
return capabilities;
}
VhtCapabilities
StaWifiMac::GetVhtCapabilities (void) const
{
VhtCapabilities capabilities;
capabilities.SetVhtSupported (1);
if (m_vhtSupported)
{
if (m_phy->GetChannelWidth () == 160)
{
capabilities.SetSupportedChannelWidthSet (1);
}
else
{
capabilities.SetSupportedChannelWidthSet (0);
}
capabilities.SetMaxMpduLength (2); //hardcoded for now (TBD)
capabilities.SetRxLdpc (m_phy->GetLdpc ());
capabilities.SetShortGuardIntervalFor80Mhz ((m_phy->GetChannelWidth () == 80) && m_phy->GetGuardInterval ());
capabilities.SetShortGuardIntervalFor160Mhz ((m_phy->GetChannelWidth () == 160) && m_phy->GetGuardInterval ());
capabilities.SetMaxAmpduLengthExponent (7); //hardcoded for now (TBD)
uint8_t maxMcs = 0;
for (uint8_t i = 0; i < m_phy->GetNMcs (); i++)
{
WifiMode mcs = m_phy->GetMcs (i);
if (mcs.GetMcsValue () > maxMcs)
{
maxMcs = mcs.GetMcsValue ();
}
}
capabilities.SetRxMcsMap (maxMcs, 1); //Only 1 SS is currently supported
capabilities.SetTxMcsMap (maxMcs, 1); //Only 1 SS is currently supported
}
return capabilities;
}
void
StaWifiMac::SetState (MacState value)
{
if (value == ASSOCIATED
&& m_state != ASSOCIATED)
{
m_assocLogger (GetBssid ());
}
else if (value != ASSOCIATED
&& m_state == ASSOCIATED)
{
m_deAssocLogger (GetBssid ());
}
m_state = value;
}
} //namespace ns3