--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/devices/wifi/nqsta-wifi-mac.cc Sat Mar 01 21:21:53 2008 +0100
@@ -0,0 +1,471 @@
+/* -*- 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");
+
+#define TRACE(x) \
+ NS_LOG_DEBUG (Simulator::Now () << " " << GetAddress () << " " << x);
+
+/*
+ * 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 ("NqstaWifiMac")
+ .SetParent<WifiMac> ()
+ .AddConstructor<NqstaWifiMac> ()
+ .AddAttribute ("ProbeRequestTimeout", "XXX",
+ Seconds (0.5),
+ MakeTimeAccessor (&NqstaWifiMac::m_probeRequestTimeout),
+ MakeTimeChecker ())
+ .AddAttribute ("AssocRequestTimeout", "XXX",
+ Seconds (0.5),
+ MakeTimeAccessor (&NqstaWifiMac::m_assocRequestTimeout),
+ MakeTimeChecker ())
+ .AddAttribute ("MaxMissedBeacons",
+ "Number of beacons which much be consecutively missed before "
+ "we attempt to restart association.",
+ Uinteger (10),
+ MakeUintegerAccessor (&NqstaWifiMac::m_maxMissedBeacons),
+ MakeUintegerChecker<uint32_t> ())
+ ;
+ return tid;
+}
+
+
+NqstaWifiMac::NqstaWifiMac ()
+ : m_state (BEACON_MISSED),
+ m_probeRequestEvent (),
+ m_assocRequestEvent (),
+ m_beaconWatchdogEnd (Seconds (0.0))
+{
+ m_dcfManager = new DcfManager ();
+
+ m_rxMiddle = new MacRxMiddle ();
+ m_rxMiddle->SetForwardCallback (MakeCallback (&NqstaWifiMac::Receive, this));
+
+ m_low = new MacLow ();
+ m_low->SetRxCallback (MakeCallback (&MacRxMiddle::Receive, m_rxMiddle));
+
+ m_dca = CreateObject<DcaTxop> ();
+ m_dca->SetLow (m_low);
+ m_dca->SetManager (m_dcfManager);
+}
+
+NqstaWifiMac::~NqstaWifiMac ()
+{}
+
+void
+NqstaWifiMac::DoDispose (void)
+{
+ delete m_rxMiddle;
+ delete m_low;
+ m_rxMiddle = 0;
+ m_low = 0;
+ m_phy = 0;
+ m_dca = 0;
+ WifiMac::DoDispose ();
+}
+
+void
+NqstaWifiMac::SetWifiPhy (Ptr<WifiPhy> phy)
+{
+ m_phy = phy;
+}
+void
+NqstaWifiMac::SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> stationManager)
+{
+ m_stationManager = 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)
+{
+ m_address = address;
+}
+void
+NqstaWifiMac::SetSsid (Ssid ssid)
+{
+ m_ssid = ssid;
+}
+
+void
+NqstaWifiMac::SetMaxMissedBeacons (uint32_t missed)
+{
+ m_maxMissedBeacons = missed;
+}
+void
+NqstaWifiMac::SetProbeRequestTimeout (Time timeout)
+{
+ m_probeRequestTimeout = timeout;
+}
+void
+NqstaWifiMac::SetAssocRequestTimeout (Time timeout)
+{
+ m_assocRequestTimeout = timeout;
+}
+
+void
+NqstaWifiMac::StartActiveAssociation (void)
+{
+ TryToEnsureAssociated ();
+}
+
+Mac48Address
+NqstaWifiMac::GetBroadcastBssid (void)
+{
+ return Mac48Address::GetBroadcast ();
+}
+
+void
+NqstaWifiMac::SetBssid (Mac48Address bssid)
+{
+ m_bssid = bssid;
+}
+void
+NqstaWifiMac::ForwardUp (Ptr<Packet> packet, const Mac48Address &address)
+{
+ m_forwardUp (packet, address);
+}
+void
+NqstaWifiMac::SendProbeRequest (void)
+{
+ TRACE ("send probe request");
+ 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)
+{
+ TRACE ("send assoc request to=" << 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)
+{
+ 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)
+{
+ TRACE ("assoc request timeout");
+ m_state = WAIT_ASSOC_RESP;
+ SendAssociationRequest ();
+}
+void
+NqstaWifiMac::ProbeRequestTimeout (void)
+{
+ TRACE ("probe request timeout");
+ m_state = WAIT_PROBE_RESP;
+ SendProbeRequest ();
+}
+void
+NqstaWifiMac::MissedBeacons (void)
+{
+ if (m_beaconWatchdogEnd > Simulator::Now ())
+ {
+ m_beaconWatchdog = Simulator::Schedule (m_beaconWatchdogEnd - Simulator::Now (),
+ &NqstaWifiMac::MissedBeacons, this);
+ return;
+ }
+ TRACE ("beacon missed");
+ m_state = BEACON_MISSED;
+ TryToEnsureAssociated ();
+}
+void
+NqstaWifiMac::RestartBeaconWatchdog (Time delay)
+{
+ m_beaconWatchdogEnd = std::max (Simulator::Now () + delay, m_beaconWatchdogEnd);
+ if (Simulator::GetDelayLeft (m_beaconWatchdog) < delay &&
+ m_beaconWatchdog.IsExpired ())
+ {
+ 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)
+{
+ if (!IsAssociated ())
+ {
+ TryToEnsureAssociated ();
+ return;
+ }
+ //TRACE ("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_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;
+ TRACE ("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);
+ }
+ }
+ }
+ m_linkUp ();
+ }
+ else
+ {
+ TRACE ("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