wifi: STAs disassociate when no enabled link remains

src/wifi/model/sta-wifi-mac.cc

@@ -596,16 +596,35 @@ StaWifiMac::MissedBeacons (uint8_t linkId)
     {
       delay = GetWifiPhy (linkId)->GetDelayUntilIdle ();
     }
-  Simulator::Schedule (delay, &StaWifiMac::Disassociated, this);
+  Simulator::Schedule (delay, &StaWifiMac::Disassociated, this, linkId);
 }
 
 void
-StaWifiMac::Disassociated (void)
+StaWifiMac::Disassociated (uint8_t linkId)
 {
-  NS_LOG_FUNCTION (this);
+  NS_LOG_FUNCTION (this << +linkId);
+
+  // disable the given link
+  GetLink (linkId).apLinkId = std::nullopt;
+  GetLink (linkId).phy->SetOffMode ();
+
+  for (uint8_t id = 0; id < GetNLinks (); id++)
+    {
+      if (GetLink (id).apLinkId.has_value ())
+        {
+          // found an enabled link
+          return;
+        }
+    }
+
   NS_LOG_DEBUG ("Set state to UNASSOCIATED and start scanning");
   SetState (UNASSOCIATED);
   m_aid = 0;  // reset AID
+  // ensure all links are on
+  for (uint8_t id = 0; id < GetNLinks (); id++)
+    {
+      GetLink (id).phy->ResumeFromOff ();
+    }
   TryToEnsureAssociated ();
 }
 
@@ -1251,10 +1270,9 @@ StaWifiMac::NotifyChannelSwitching (uint8_t linkId)
 
   WifiMac::NotifyChannelSwitching (linkId);
 
-  if (IsInitialized ())
+  if (IsInitialized () && IsAssociated ())
     {
-      // TODO handle deassociation of a link in ML setup
-      Disassociated ();
+      Disassociated (linkId);
     }
 }
 

src/wifi/model/sta-wifi-mac.h

@@ -382,9 +382,13 @@ private:
    */
   void RestartBeaconWatchdog (Time delay, uint8_t linkId);
   /**
-   * Take actions after disassociation.
+   * Check if any enabled link remains after the given link is disabled (because,
+   * e.g., the maximum number of beacons is missed or the channel is switched).
+   * If no enabled link remains, proceed with disassociation.
+   *
+   * \param linkId the ID of the given link
    */
-  void Disassociated (void);
+  void Disassociated (uint8_t linkId);
   /**
    * Return an instance of SupportedRates that contains all rates that we support
    * including HT rates.