ieee80211: start scan dwell after channel and probe completion

src/inet/linklayer/ieee80211/mac/Ieee80211BssidReq.msg

@@ -0,0 +1,16 @@
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+//
+
+import inet.common.INETDefs;
+import inet.common.TagBase;
+import inet.linklayer.common.MacAddress;
+
+namespace inet;
+
+// The management procedure's BSSID for Address3 of an outgoing management frame.
+// It is independent of the receiver address and survives queuing/state changes.
+class Ieee80211BssidReq extends TagBase
+{
+    MacAddress bssid;
+}

src/inet/linklayer/ieee80211/mac/Ieee80211Mac.cc

@@ -6,6 +6,7 @@
 
 
 #include "inet/linklayer/ieee80211/mac/Ieee80211Mac.h"
+#include "inet/linklayer/ieee80211/mac/Ieee80211BssidReq_m.h"
 
 #include <algorithm>
 
@@ -46,8 +47,8 @@ Ieee80211Mac::Ieee80211Mac()
 
 Ieee80211Mac::~Ieee80211Mac()
 {
-    if (pendingRadioConfigMsg)
-        delete pendingRadioConfigMsg;
+    cancelAndDelete(radioConfigRetry);
+    delete pendingRadioConfigMsg;
 }
 
 void Ieee80211Mac::initialize(int stage)
@@ -156,15 +157,46 @@ void Ieee80211Mac::handleMessageWhenUp(cMessage *message)
 
 void Ieee80211Mac::handleSelfMessage(cMessage *msg)
 {
-    ASSERT(false);
+    if (msg == radioConfigRetry) {
+        // Retry after delivered receptions and exchange callbacks have reserved any SIFS response.
+        if (pendingRadioConfigMsg && rx->isMediumFree() && !tx->isTransmissionPending() &&
+            !(mib->qos ? hcf->isFrameSequenceRunning() : dcf->isFrameSequenceRunning()))
+            sendDownPendingRadioConfigMsg();
+    }
+    else
+        ASSERT(false);
+}
+
+void Ieee80211Mac::scheduleRadioConfigRetry()
+{
+    Enter_Method("scheduleRadioConfigRetry");
+    if (pendingRadioConfigMsg) {
+        if (!radioConfigRetry)
+            radioConfigRetry = new cMessage("radioConfigRetry");
+        if (!radioConfigRetry->isScheduled())
+            scheduleAt(simTime(), radioConfigRetry);
+    }
 }
 
+
+void Ieee80211Mac::clearPendingRadioConfig()
+{
+    if (radioConfigRetry)
+        cancelEvent(radioConfigRetry);
+    delete pendingRadioConfigMsg;
+    pendingRadioConfigMsg = nullptr;
+}
+
+
 void Ieee80211Mac::handleMgmtPacket(Packet *packet)
 {
     const auto& header = makeShared<Ieee80211MgmtHeader>();
     header->setType((Ieee80211FrameType)packet->getTag<Ieee80211SubtypeReq>()->getSubtype());
     header->setReceiverAddress(packet->getTag<MacAddressReq>()->getDestAddress());
-    if (mib->mode == Ieee80211Mib::INFRASTRUCTURE && mib->bssStationData.stationType == Ieee80211Mib::ACCESS_POINT)
+    // IEEE Std 802.11-2024, 9.3.3.1: management supplies its intended BSSID.
+    if (auto bssid = packet->findTag<Ieee80211BssidReq>())
+        header->setAddress3(bssid->getBssid());
+    else if (mib->mode == Ieee80211Mib::INFRASTRUCTURE && mib->bssStationData.stationType == Ieee80211Mib::ACCESS_POINT)
         header->setAddress3(mib->bssData.bssid);
     packet->insertAtFront(header);
     packet->insertAtBack(makeShared<Ieee80211MacTrailer>());
@@ -239,9 +271,9 @@ void Ieee80211Mac::handleUpperCommand(cMessage *msg)
             sendDown(msg);
         }
         else {
-            // TODO waiting potentially indefinitely?! wtf?!
             EV_DEBUG << "Delaying " << msg->getName() << " until next IDLE or DEFER state\n";
             pendingRadioConfigMsg = msg;
+            scheduleRadioConfigRetry();
         }
     }
     else {
@@ -340,6 +372,8 @@ void Ieee80211Mac::receiveSignal(cComponent *source, simsignal_t signalID, intva
             configureRadioMode(IRadio::RADIO_MODE_RECEIVER); // FIXME this is in a very wrong place!!! should be done explicitly from coordination function!
         }
         rx->transmissionStateChanged(transmissionState);
+        if (transmissionFinished)
+            scheduleRadioConfigRetry();
     }
     else if (signalID == IRadio::receivedSignalPartChangedSignal) {
         rx->receivedSignalPartChanged(static_cast<IRadioSignal::SignalPart>(value));
@@ -428,11 +462,13 @@ void Ieee80211Mac::handleStartOperation(LifecycleOperation *operation)
 // FIXME
 void Ieee80211Mac::handleStopOperation(LifecycleOperation *operation)
 {
+    clearPendingRadioConfig();
 }
 
 // FIXME
 void Ieee80211Mac::handleCrashOperation(LifecycleOperation *operation)
 {
+    clearPendingRadioConfig();
 }
 
 } // namespace ieee80211

src/inet/linklayer/ieee80211/mac/Ieee80211Mac.h

@@ -60,6 +60,7 @@ class INET_API Ieee80211Mac : public MacProtocolBase
 
     // The last change channel message received and not yet sent to the physical layer, or nullptr.
     cMessage *pendingRadioConfigMsg = nullptr;
+    cMessage *radioConfigRetry = nullptr;
 
   protected:
     virtual int numInitStages() const override { return NUM_INIT_STAGES; }
@@ -79,6 +80,7 @@ class INET_API Ieee80211Mac : public MacProtocolBase
 
     /** @brief Handle timer self messages */
     virtual void handleSelfMessage(cMessage *msg) override;
+    void clearPendingRadioConfig();
 
     /** @brief Handle packets from management */
     virtual void handleMgmtPacket(Packet *packet);
@@ -106,6 +108,7 @@ class INET_API Ieee80211Mac : public MacProtocolBase
     virtual void sendUpFrame(Packet *frame);
     virtual void sendDownFrame(Packet *frame);
     virtual void sendDownPendingRadioConfigMsg();
+    virtual void scheduleRadioConfigRetry();
 
     virtual void processUpperFrame(Packet *packet, const Ptr<const Ieee80211DataOrMgmtHeader>& header);
     virtual void processLowerFrame(Packet *packet, const Ptr<const Ieee80211MacHeader>& header);

src/inet/linklayer/ieee80211/mac/Tx.h

@@ -42,6 +42,7 @@ class INET_API Tx : public SimpleModule, public ITx
     virtual void transmitFrame(Packet *packet, const Ptr<const Ieee80211MacHeader>& header, ITx::ICallback *txCallback) override;
     virtual void transmitFrame(Packet *packet, const Ptr<const Ieee80211MacHeader>& header, simtime_t ifs, ITx::ICallback *txCallback) override;
     virtual void radioTransmissionFinished() override;
+    virtual bool isTransmissionPending() const override { return frame != nullptr; }
 };
 
 } // namespace ieee80211

src/inet/linklayer/ieee80211/mac/contention/Contention.cc

@@ -160,6 +160,9 @@ void Contention::mediumStateChanged(bool mediumFree)
     this->mediumFree = mediumFree;
     lastChannelBusyTime = simTime();
     handleWithFSM(MEDIUM_STATE_CHANGED);
+    // An idle contender otherwise has no transition that applies a deferred channel change.
+    if (mediumFree)
+        mac->scheduleRadioConfigRetry();
 }
 
 void Contention::handleMessage(cMessage *msg)

src/inet/linklayer/ieee80211/mac/contract/ITx.h

@@ -34,6 +34,9 @@ class INET_API ITx
     virtual void transmitFrame(Packet *packet, const Ptr<const Ieee80211MacHeader>& header, ICallback *callback) = 0;
     virtual void transmitFrame(Packet *packet, const Ptr<const Ieee80211MacHeader>& header, simtime_t ifs, ICallback *callback) = 0;
     virtual void radioTransmissionFinished() = 0;
+
+    // Includes a frame waiting for its inter-frame space, as well as on-air transmission.
+    virtual bool isTransmissionPending() const = 0;
 };
 
 } // namespace ieee80211

src/inet/linklayer/ieee80211/mac/coordinationfunction/Dcf.h

@@ -123,6 +123,7 @@ class INET_API Dcf : public ICoordinationFunction, public IFrameSequenceHandler:
 
   public:
     virtual ~Dcf();
+    virtual bool isFrameSequenceRunning() const { return frameSequenceHandler->isSequenceRunning(); }
 
     // ICoordinationFunction
     virtual void processUpperFrame(Packet *packet, const Ptr<const Ieee80211DataOrMgmtHeader>& header) override;

src/inet/linklayer/ieee80211/mac/coordinationfunction/Hcf.h

@@ -164,6 +164,7 @@ class INET_API Hcf : public ICoordinationFunction, public IFrameSequenceHandler:
 
   public:
     virtual ~Hcf();
+    virtual bool isFrameSequenceRunning() const { return frameSequenceHandler->isSequenceRunning(); }
 
     // ICoordinationFunction
     virtual void processUpperFrame(Packet *packet, const Ptr<const Ieee80211DataOrMgmtHeader>& header) override;