gattlib: Introduce 'gattlib_get_rssi_from_mac()'

bluez/gattlib_connect.c

@@ -554,6 +554,11 @@ int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi)
 	return GATTLIB_NOT_SUPPORTED;
 }
 
+int gattlib_get_rssi_from_mac(void *adapter, const char *mac_address, int16_t *rssi)
+{
+	return GATTLIB_NOT_SUPPORTED;
+}
+
 int gattlib_get_advertisement_data(gatt_connection_t *connection, gattlib_advertisement_data_t **advertisement_data,
 		uint16_t *manufacturer_id, uint8_t **manufacturer_data, size_t *manufacturer_data_size)
 {

dbus/gattlib.c

@@ -93,7 +93,28 @@ gboolean on_handle_device_property_change(
 	return TRUE;
 }
 
-static void get_object_path_from_mac(const char *adapter_name, const char *mac_address, char *object_path, size_t object_path_len)
+void get_device_path_from_mac_with_adapter(OrgBluezAdapter1* adapter, const char *mac_address, char *object_path, size_t object_path_len)
+{
+	char device_address_str[20 + 1];
+	const char* adapter_path = g_dbus_proxy_get_object_path((GDBusProxy *)ORG_BLUEZ_ADAPTER1_PROXY(adapter));
+
+	// Transform string from 'DA:94:40:95:E0:87' to 'dev_DA_94_40_95_E0_87'
+	strncpy(device_address_str, mac_address, sizeof(device_address_str));
+	for (int i = 0; i < strlen(device_address_str); i++) {
+		if (device_address_str[i] == ':') {
+			device_address_str[i] = '_';
+		}
+	}
+
+	// Force a null-terminated character
+	device_address_str[20] = '\0';
+
+	// Generate object path like: /org/bluez/hci0/dev_DA_94_40_95_E0_87
+	snprintf(object_path, object_path_len, "%s/dev_%s", adapter_path, device_address_str);
+}
+
+
+void get_device_path_from_mac(const char *adapter_name, const char *mac_address, char *object_path, size_t object_path_len)
 {
 	char device_address_str[20 + 1];
 	const char* adapter;
@@ -132,7 +153,7 @@ gatt_connection_t *gattlib_connect(const char *src, const char *dst, unsigned lo
 	GError *error = NULL;
 	char object_path[100];
 
-	get_object_path_from_mac(src, dst, object_path, sizeof(object_path));
+	get_device_path_from_mac(src, dst, object_path, sizeof(object_path));
 
 	gattlib_context_t* conn_context = calloc(sizeof(gattlib_context_t), 1);
 	if (conn_context == NULL) {
@@ -1344,7 +1365,8 @@ int gattlib_notification_stop(gatt_connection_t* connection, const uuid_t* uuid)
 	}
 }
 
-int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi) {
+int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi)
+{
 	gattlib_context_t* conn_context = connection->context;
 
 	if (rssi == NULL) {
@@ -1356,6 +1378,39 @@ int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi) {
 	return GATTLIB_SUCCESS;
 }
 
+int gattlib_get_rssi_from_mac(void *adapter, const char *mac_address, int16_t *rssi)
+{
+	GError *error = NULL;
+	char object_path[100];
+
+	if (rssi == NULL) {
+		return GATTLIB_INVALID_PARAMETER;
+	}
+
+	if (adapter != NULL) {
+		get_device_path_from_mac_with_adapter((OrgBluezAdapter1*)adapter, mac_address, object_path, sizeof(object_path));
+	} else {
+		get_device_path_from_mac(NULL, mac_address, object_path, sizeof(object_path));
+	}
+
+	OrgBluezDevice1* bluez_device1 = org_bluez_device1_proxy_new_for_bus_sync(
+			G_BUS_TYPE_SYSTEM,
+			G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_NONE,
+			"org.bluez",
+			object_path,
+			NULL,
+			&error);
+	if (error) {
+		fprintf(stderr, "Failed to connection to new DBus Bluez Device: %s\n",
+			error->message);
+		g_error_free(error);
+		return GATTLIB_ERROR_DBUS;
+	}
+
+	*rssi = org_bluez_device1_get_rssi(bluez_device1);
+	return GATTLIB_SUCCESS;
+}
+
 int gattlib_get_advertisement_data(gatt_connection_t *connection, gattlib_advertisement_data_t **advertisement_data,
 		uint16_t *manufacturer_id, uint8_t **manufacturer_data, size_t *manufacturer_data_size)
 {

dbus/gattlib_internal.h

@@ -55,4 +55,7 @@ typedef struct {
 
 gboolean stop_scan_func(gpointer data);
 
+void get_device_path_from_mac_with_adapter(OrgBluezAdapter1* adapter, const char *mac_address, char *object_path, size_t object_path_len);
+void get_device_path_from_mac(const char *adapter_name, const char *mac_address, char *object_path, size_t object_path_len);
+
 #endif

gattlib-py/examples/find_eddystone/find_eddystone.py

@@ -10,14 +10,15 @@ args = parser.parse_args()
 
 EDDYSTONE_COMMON_DATA_UUID = 'FEAA'
 
-
-def on_discovered_ble_device(device):
-    print("Find Eddystone device %s" % device.id)
-
-
 # Use default adapter
 default_adapter = adapter.Adapter()
 
+
+def on_discovered_ble_device(device, user_data):
+    rssi = default_adapter.get_rssi_from_mac(device.id)
+    print("Find Eddystone device %s (RSSI:%d)" % (device.id, rssi))
+
+
 # Scan for 30 seconds
 default_adapter.open()
 default_adapter.scan_enable(on_discovered_ble_device, 30, uuids=[EDDYSTONE_COMMON_DATA_UUID])

gattlib-py/gattlib/__init__.py

@@ -97,3 +97,7 @@ gattlib_register_on_disconnect.argtypes = [c_void_p, py_object, py_object]
 # int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi)
 gattlib_get_rssi = gattlib.gattlib_get_rssi
 gattlib_get_rssi.argtypes = [c_void_p, POINTER(c_int16)]
+
+# int gattlib_get_rssi_from_mac(void *adapter, const char *mac_address, int16_t *rssi)
+gattlib_get_rssi_from_mac = gattlib.gattlib_get_rssi_from_mac
+gattlib_get_rssi_from_mac.argtypes = [c_void_p, c_char_p, POINTER(c_int16)]

gattlib-py/gattlib/adapter.py

@@ -67,3 +67,11 @@ class Adapter:
     def scan_disable(self):
         ret = gattlib.gattlib_adapter_scan_disable(self._adapter)
         handle_return(ret)
+
+    def get_rssi_from_mac(self, mac_address):
+        if isinstance(mac_address, str):
+            mac_address = mac_address.encode("utf-8")
+
+        rssi = c_int16(0)
+        gattlib_get_rssi_from_mac(self._adapter, mac_address, byref(rssi))
+        return rssi.value

include/gattlib.h

@@ -350,6 +350,20 @@ void gattlib_register_indication(gatt_connection_t* connection, gattlib_event_ha
  */
 int gattlib_get_rssi(gatt_connection_t *connection, int16_t *rssi);
 
+/**
+ * @brief Function to retrieve RSSI from a MAC Address
+ *
+ * @note: This function is mainly used before a connection is established. Once the connection
+ * established, the function `gattlib_get_rssi()` should be preferred.
+ *
+ * @param adapter is the adapter the new device has been seen
+ * @param mac_address is the MAC address of the device to get the RSSI
+ * @param rssi is the Received Signal Strength Indicator of the remote device
+ *
+ * @return GATTLIB_SUCCESS on success or GATTLIB_* error code
+ */
+int gattlib_get_rssi_from_mac(void *adapter, const char *mac_address, int16_t *rssi);
+
 /**
  * @brief Function to retrieve Advertisement Data of the GATT connection
  *