[linux] Remove known devices before running BLE scan (#5946)

* [python] Remove known devices before running BLE scan Linux BLE layer tries to connect to known devices, cached by Bluez daemon before running the active scan. It may cause an issue when trying to connect to a device which is no longer advertising or it has changed its BLE address which can be especially painful after enabling features like BLE address randomization. Remove known devices before running an active BLE scan. * Restyled by clang-format Co-authored-by: Restyled.io <[email protected]>
project-chip · Apr 12, 2021 · 4d7fd4d · 4d7fd4d
1 parent dada1be
commit 4d7fd4d
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Showing 2 changed files with 35 additions and 2 deletions.
diff --git a/src/platform/Linux/bluez/ChipDeviceScanner.cpp b/src/platform/Linux/bluez/ChipDeviceScanner.cpp
@@ -230,6 +230,35 @@ void ChipDeviceScanner::ReportDevice(BluezDevice1 * device)
     mDelegate->OnDeviceScanned(device, deviceInfo);
 }
 
+void ChipDeviceScanner::RemoveDevice(BluezDevice1 * device)
+{
+    if (device == nullptr)
+    {
+        return;
+    }
+
+    if (strcmp(bluez_device1_get_adapter(device), g_dbus_proxy_get_object_path(G_DBUS_PROXY(mAdapter))) != 0)
+    {
+        return;
+    }
+
+    chip::Ble::ChipBLEDeviceIdentificationInfo deviceInfo;
+
+    if (!BluezGetChipDeviceInfo(*device, deviceInfo))
+    {
+        return;
+    }
+
+    const auto devicePath = g_dbus_proxy_get_object_path(G_DBUS_PROXY(device));
+    GError * error        = nullptr;
+
+    if (!bluez_adapter1_call_remove_device_sync(mAdapter, devicePath, nullptr, &error))
+    {
+        ChipLogDetail(Ble, "Failed to remove device %s: %s", devicePath, error->message);
+        g_error_free(error);
+    }
+}
+
 int ChipDeviceScanner::MainLoopStartScan(ChipDeviceScanner * self)
 {
     GError * error = nullptr;
@@ -238,10 +267,10 @@ int ChipDeviceScanner::MainLoopStartScan(ChipDeviceScanner * self)
     self->mInterfaceChangedSignal =
         g_signal_connect(self->mManager, "interface-proxy-properties-changed", G_CALLBACK(SignalInterfaceChanged), self);
 
-    ChipLogProgress(Ble, "BLE scanning through known devices.");
+    ChipLogProgress(Ble, "BLE removing known devices.");
     for (BluezObject & object : BluezObjectList(self->mManager))
     {
-        self->ReportDevice(bluez_object_get_device1(&object));
+        self->RemoveDevice(bluez_object_get_device1(&object));
     }
 
     ChipLogProgress(Ble, "BLE initiating scan.");

diff --git a/src/platform/Linux/bluez/ChipDeviceScanner.h b/src/platform/Linux/bluez/ChipDeviceScanner.h
@@ -86,6 +86,10 @@ class ChipDeviceScanner
     /// Check if a given device is a CHIP device and if yes, report it as discovered
     void ReportDevice(BluezDevice1 * device);
 
+    /// Check if a given device is a CHIP device and if yes, remove it from the adapter
+    /// so that it can be re-discovered if it's still advertising.
+    void RemoveDevice(BluezDevice1 * device);
+
     GDBusObjectManager * mManager         = nullptr;
     BluezAdapter1 * mAdapter              = nullptr;
     GCancellable * mCancellable           = nullptr;