Only start scan/advertise when host re-synced if duration was indefinite.

Previously when the host reset while scanning (if active prior) it would be restarted automatically.
This caused errors for some applications and has been removed since the event invokes the scan
ended callback for the app to take action. Instead scanning will now only be restarted if the duration
was indefinite and a callback was set for the advertisment events, this use case is less likely to have
a scan ended callback.

Advertising (if active prior) would be started without regard to it's previous state.
This has been corrected to only start advertising again if it was advertising for an idefinite time.

src/NimBLEAdvertising.cpp

@@ -312,6 +312,9 @@ void NimBLEAdvertising::start(uint32_t duration, void (*advCompleteCB)(NimBLEAdv
         return;
     }
 
+    // Save the duration incase of host reset so we can restart with the same params
+    m_duration = duration;
+
     if(duration == 0){
         duration = BLE_HS_FOREVER;
     }
@@ -495,6 +498,7 @@ void NimBLEAdvertising::start(uint32_t duration, void (*advCompleteCB)(NimBLEAdv
  */
 void NimBLEAdvertising::stop() {
     NIMBLE_LOGD(LOG_TAG, ">> stop");
+
     int rc = ble_gap_adv_stop();
     if (rc != 0 && rc != BLE_HS_EALREADY) {
         NIMBLE_LOGE(LOG_TAG, "ble_gap_adv_stop rc=%d %s", rc, NimBLEUtils::returnCodeToString(rc));
@@ -528,8 +532,14 @@ bool NimBLEAdvertising::isAdvertising() {
  * Host reset seems to clear advertising data,
  * we need clear the flag so it reloads it.
  */
-void NimBLEAdvertising::onHostReset() {
+void NimBLEAdvertising::onHostSync() {
+    NIMBLE_LOGD(LOG_TAG, "Host re-synced");
+
     m_advDataSet = false;
+    // If we were advertising forever, restart it now
+    if(m_duration == 0) {
+        start(m_duration, m_advCompCB);
+    }
 }
 
 
@@ -543,6 +553,19 @@ int NimBLEAdvertising::handleGapEvent(struct ble_gap_event *event, void *arg) {
     NimBLEAdvertising *pAdv = (NimBLEAdvertising*)arg;
 
     if(event->type == BLE_GAP_EVENT_ADV_COMPLETE) {
+        switch(event->adv_complete.reason) {
+            // Don't call the callback if host reset, we want to
+            // preserve the active flag until re-sync to restart advertising.
+            case BLE_HS_ETIMEOUT_HCI:
+            case BLE_HS_EOS:
+            case BLE_HS_ECONTROLLER:
+            case BLE_HS_ENOTSYNCED:
+                NIMBLE_LOGC(LOG_TAG, "host reset, rc=%d", event->adv_complete.reason);
+                NimBLEDevice::onReset(event->adv_complete.reason);
+                return 0;
+            default:
+                break;
+        }
         pAdv->advCompleteCB();
     }
     return 0;

src/NimBLEAdvertising.h

@@ -95,7 +95,7 @@ public:
 private:
     friend class NimBLEDevice;
 
-    void                    onHostReset();
+    void                    onHostSync();
     static int              handleGapEvent(struct ble_gap_event *event, void *arg);
 
     ble_hs_adv_fields       m_advData;
@@ -108,7 +108,7 @@ private:
     bool                    m_advDataSet;
     void                    (*m_advCompCB)(NimBLEAdvertising *pAdv);
     uint8_t                 m_slaveItvl[4];
-
+    uint32_t                m_duration;
 };
 
 #endif // #if defined(CONFIG_BT_NIMBLE_ROLE_PERIPHERAL)

src/NimBLEDevice.cpp

@@ -410,30 +410,16 @@ void NimBLEDevice::stopAdvertising() {
 
     m_synced = false;
 
-#if defined(CONFIG_BT_NIMBLE_ROLE_OBSERVER)
-    if(m_pScan != nullptr) {
-        m_pScan->onHostReset();
-    }
-#endif
-
-/*  Not needed
-    if(m_pServer != nullptr) {
-        m_pServer->onHostReset();
-    }
-
-    for(auto it = m_cList.cbegin(); it != m_cList.cend(); ++it) {
-        (*it)->onHostReset();
-    }
-*/
-
-#if defined(CONFIG_BT_NIMBLE_ROLE_BROADCASTER)
-    if(m_bleAdvertising != nullptr) {
-        m_bleAdvertising->onHostReset();
-    }
-#endif
-
     NIMBLE_LOGC(LOG_TAG, "Resetting state; reason=%d, %s", reason,
                         NimBLEUtils::returnCodeToString(reason));
+
+#if defined(CONFIG_BT_NIMBLE_ROLE_OBSERVER)
+    if(initialized) {
+        if(m_pScan != nullptr) {
+            m_pScan->onHostReset();
+        }
+    }
+#endif
 } // onReset
 
 
@@ -462,15 +448,13 @@ void NimBLEDevice::stopAdvertising() {
     if(initialized) {
 #if defined(CONFIG_BT_NIMBLE_ROLE_OBSERVER)
         if(m_pScan != nullptr) {
-            // Restart scanning with the last values sent, allow to clear results.
+            m_pScan->onHostSync();
-            m_pScan->start(m_pScan->m_duration, m_pScan->m_scanCompleteCB);
         }
 #endif
 
 #if defined(CONFIG_BT_NIMBLE_ROLE_BROADCASTER)
         if(m_bleAdvertising != nullptr) {
-            // Restart advertisng, parameters should already be set.
+            m_bleAdvertising->onHostSync();
-            m_bleAdvertising->start();
         }
 #endif
     }

src/NimBLEScan.cpp

@@ -41,6 +41,7 @@ NimBLEScan::NimBLEScan() {
     m_ignoreResults                  = false;
     m_wantDuplicates                 = false;
     m_pTaskData                      = nullptr;
+    m_duration                       = BLE_HS_FOREVER; // make sure this is non-zero in the event of a host reset
 }
 
 
@@ -378,12 +379,25 @@ void NimBLEScan::erase(const NimBLEAddress &address) {
 
 
 /**
- * @brief If the host reset the scan will have stopped so we should set the flag as stopped.
+ * @brief Called when host reset, we set a flag to stop scanning until synced.
  */
 void NimBLEScan::onHostReset() {
+    m_ignoreResults = true;
 }
 
 
+/**
+ * @brief If the host reset and re-synced this is called.
+ * If the application was scanning indefinitely with a callback, restart it.
+ */
+void NimBLEScan::onHostSync() {
+    m_ignoreResults = false;
+
+    if(m_duration == 0 && m_pAdvertisedDeviceCallbacks != nullptr) {
+        start(m_duration, m_scanCompleteCB);
+    }
+}
+
 /**
  * @brief Get the results of the scan.
  * @return NimBLEScanResults object.

src/NimBLEScan.h

@@ -83,6 +83,7 @@ private:
     ~NimBLEScan();
     static int          handleGapEvent(ble_gap_event*  event, void* arg);
     void                onHostReset();
+    void                onHostSync();
 
     NimBLEAdvertisedDeviceCallbacks*    m_pAdvertisedDeviceCallbacks = nullptr;
     void                                (*m_scanCompleteCB)(NimBLEScanResults scanResults);