[tcat][ble] introduce notifier events to update TCAT advertisement data / use bool for advertising state (#12913)

To get an update of TCAT advertisement data when the active dataset changes, notifier events are
introduced. This also refactors the existing adv update on MLE role change to use a notifier event.

This update now covers all cases where an application/CLI/user changes the active dataset, which should
be then reflected in TCAT advertisement flag values.

The 'requested advertising state' is refactored from a BleState to a bool, to make the code more
readable and avoid subtle errors.

src/core/common/notifier.cpp

@@ -140,6 +140,10 @@ void Notifier::EmitEvents(void)
 #if OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE && OPENTHREAD_CONFIG_BORDER_AGENT_ADMITTER_ENABLE
     Get<MeshCoP::BorderAgent::Admitter>().HandleNotifierEvents(events);
 #endif
+#if OPENTHREAD_CONFIG_BLE_TCAT_ENABLE
+    Get<Ble::BleSecure>().HandleNotifierEvents(events);
+    Get<MeshCoP::TcatAgent>().HandleNotifierEvents(events);
+#endif
 #if OPENTHREAD_CONFIG_MLR_ENABLE || (OPENTHREAD_FTD && OPENTHREAD_CONFIG_TMF_PROXY_MLR_ENABLE)
     Get<Mlr::Manager>().HandleNotifierEvents(events);
 #endif
@@ -190,9 +194,6 @@ void Notifier::EmitEvents(void)
 #if OPENTHREAD_CONFIG_LINK_METRICS_MANAGER_ENABLE
     Get<Utils::LinkMetricsManager>().HandleNotifierEvents(events);
 #endif
-#if OPENTHREAD_CONFIG_BLE_TCAT_ENABLE
-    Get<MeshCoP::TcatAgent>().HandleNotifierEvents(events);
-#endif
 
     for (ExternalCallback &callback : mExternalCallbacks)
     {

src/core/radio/ble_secure.cpp

@@ -56,7 +56,7 @@ BleSecure::BleSecure(Instance &aInstance)
     , mSendMessage(nullptr)
     , mTransmitTask(aInstance)
     , mBleState(kStopped)
-    , mBleAdvRequestedState(kStopped)
+    , mIsBleAdvRequested(false)
     , mMtuSize(kInitialMtuSize)
 {
 }
@@ -86,9 +86,9 @@ Error BleSecure::Start(ConnectCallback aConnectHandler, ReceiveCallback aReceive
     mTls.SetConnectCallback(HandleTlsConnectEvent, this);
 
     // attempt to start BLE advertising only if everything else succeeded.
-    mBleState             = kNotAdvertising;
-    mBleAdvRequestedState = kAdvertising;
-    error                 = SetRequestedBleAdvertisementsState();
+    mBleState          = kNotAdvertising;
+    mIsBleAdvRequested = true;
+    error              = SetRequestedBleAdvertisementsState();
 
 exit:
     if (error != kErrorNone && error != kErrorAlready)
@@ -118,9 +118,9 @@ void BleSecure::Stop(void)
     // Even if stop-advertisements or disable BLE would fail, we continue closing TLS and stopping TCAT agent.
     IgnoreError(otPlatBleGapAdvStop(&GetInstance()));
     IgnoreError(otPlatBleDisable(&GetInstance()));
-    mBleState             = kStopped;
-    mBleAdvRequestedState = kStopped;
-    mMtuSize              = kInitialMtuSize;
+    mBleState          = kStopped;
+    mIsBleAdvRequested = false;
+    mMtuSize           = kInitialMtuSize;
 
     mTls.Close();
     Get<MeshCoP::TcatAgent>().Stop();
@@ -214,9 +214,17 @@ exit:
     return error;
 }
 
+void BleSecure::HandleNotifierEvents(Events aEvents)
+{
+    if (aEvents.ContainsAny(kEventActiveDatasetChanged | kEventThreadRoleChanged))
+    {
+        IgnoreError(NotifyAdvertisementChanged());
+    }
+}
+
 void BleSecure::NotifySendAdvertisements(bool aSendAdvertisements)
 {
-    mBleAdvRequestedState = aSendAdvertisements ? kAdvertising : kNotAdvertising;
+    mIsBleAdvRequested = aSendAdvertisements;
     IgnoreError(SetRequestedBleAdvertisementsState());
 }
 
@@ -227,12 +235,12 @@ Error BleSecure::SetRequestedBleAdvertisementsState(void)
     Error error = kErrorNone;
 
     // Must not make GapAdv platform calls when kStopped, or kConnected.
-    if (mBleAdvRequestedState == kAdvertising && mBleState == kNotAdvertising)
+    if (mIsBleAdvRequested && mBleState == kNotAdvertising)
     {
         SuccessOrExit(error = otPlatBleGapAdvStart(&GetInstance(), OT_BLE_ADV_INTERVAL_DEFAULT));
         mBleState = kAdvertising;
     }
-    else if (mBleAdvRequestedState != kAdvertising && mBleState == kAdvertising)
+    else if (!mIsBleAdvRequested && mBleState == kAdvertising)
     {
         SuccessOrExit(error = otPlatBleGapAdvStop(&GetInstance()));
         mBleState = kNotAdvertising;

src/core/radio/ble_secure.hpp

@@ -35,6 +35,7 @@
 
 #include <openthread/ble_secure.h>
 
+#include "common/notifier.hpp"
 #include "meshcop/meshcop.hpp"
 #include "meshcop/secure_transport.hpp"
 #include "meshcop/tcat_agent.hpp"
@@ -54,6 +55,8 @@ namespace Ble {
 
 class BleSecure : public InstanceLocator, public MeshCoP::Tls::Extension, private NonCopyable
 {
+    friend class ot::Notifier;
+
 public:
     /**
      * Pointer to call when the secure BLE connection state changes.
@@ -356,6 +359,8 @@ private:
     static constexpr uint16_t kTxBleHandle      = 0;   // Characteristics Handle for TX (not used)
     static constexpr uint16_t kTlsDataMaxSize   = 800; // Maximum size of data chunks sent with mTls.Send(..)
 
+    void HandleNotifierEvents(Events aEvents);
+
     static void HandleTlsConnectEvent(MeshCoP::Tls::ConnectEvent aEvent, void *aContext);
     void        HandleTlsConnectEvent(MeshCoP::Tls::ConnectEvent aEvent);
 
@@ -381,7 +386,7 @@ private:
     TxTask                    mTransmitTask;
     uint8_t                   mPacketBuffer[kPacketBufferSize];
     BleState                  mBleState;
-    BleState                  mBleAdvRequestedState;
+    bool                      mIsBleAdvRequested;
     uint16_t                  mMtuSize;
 };
 

src/core/thread/mle.cpp

@@ -319,10 +319,6 @@ void Mle::SetRole(DeviceRole aRole)
         break;
     }
 
-#if OPENTHREAD_CONFIG_BLE_TCAT_ENABLE
-    IgnoreError(Get<Ble::BleSecure>().NotifyAdvertisementChanged());
-#endif
-
     // If the previous state is disabled, the parent can be in kStateRestored.
     if (!IsChild() && oldRole != kRoleDisabled)
     {