Handle DBusException in NetworkManagerMonitor (#636)

* Catch DBus permission errors
* Better DBusException handling in NetworkManagerMonitor

src/vorta/network_status/network_manager.py

@@ -16,11 +16,16 @@ def __init__(self, nm_adapter: 'NetworkManagerDBusAdapter' = None):
         self._nm = nm_adapter or NetworkManagerDBusAdapter.get_system_nm_adapter()
 
     def is_network_metered(self) -> bool:
+        try:
             return self._nm.get_global_metered_status() in (NMMetered.YES, NMMetered.GUESS_YES)
+        except DBusException:
+            logger.exception("Failed to check if network is metered, assuming it isn't")
+            return False
 
     def get_current_wifi(self) -> Optional[str]:
         # Only check the primary connection. VPN over WiFi will still show the WiFi as Primary Connection.
         # We don't check all active connections, as NM won't disable WiFi when connecting a cable.
+        try:
             active_connection_path = self._nm.get_primary_connection_path()
             if not active_connection_path:
                 return
@@ -30,11 +35,24 @@ def get_current_wifi(self) -> Optional[str]:
                 ssid = self._get_ssid_from_settings(settings)
                 if ssid:
                     return ssid
+        except DBusException:
+            logger.exception("Failed to get currently connected WiFi network, assuming none")
+            return None
 
     def get_known_wifis(self) -> Optional[List[SystemWifiInfo]]:
+        try:
+            connections_paths = self._nm.get_connections_paths()
+        except DBusException:
+            logger.exception("Failed to list connections")
+            return None
+
         wifis = []
-        for connection_path in self._nm.get_connections_paths():
+        for connection_path in connections_paths:
+            try:
                 settings = self._nm.get_settings(connection_path)
+            except DBusException:
+                logger.warning("Couldn't load settings for %s", connection_path, exc_info=True)
+            else:
                 ssid = self._get_ssid_from_settings(settings)
                 if ssid:
                     timestamp = settings['connection'].get('timestamp')

tests/network_manager/test_network_manager.py

@@ -5,7 +5,7 @@
 
 from vorta.network_status.abc import SystemWifiInfo
 from vorta.network_status.network_manager import NetworkManagerMonitor, NMMetered, NetworkManagerDBusAdapter, \
-    ActiveConnectionInfo, decode_ssid
+    ActiveConnectionInfo, decode_ssid, DBusException
 
 
 @pytest.fixture
@@ -95,6 +95,27 @@ def test_get_known_wifis_with_never_used_connection(nm_monitor):
     )]
 
 
+def test_get_known_wifis_partial_failure(nm_monitor):
+    nm_monitor._nm.get_connections_paths.return_value = [
+        '/org/freedesktop/NetworkManager/Settings/12',
+        '/org/freedesktop/NetworkManager/Settings/42',
+    ]
+    nm_monitor._nm.get_settings.side_effect = [
+        DBusException("Test"),
+        {
+            'connection': {},
+            '802-11-wireless': {'ssid': [84, 69, 83, 84]},
+        },
+    ]
+
+    result = nm_monitor.get_known_wifis()
+
+    assert result == [SystemWifiInfo(
+        ssid='TEST',
+        last_connected=None,
+    )]
+
+
 def test_get_known_wifis_with_no_wifi_connections(nm_monitor):
     nm_monitor._nm.get_connections_paths.return_value = ['/org/freedesktop/NetworkManager/Settings/12']
     nm_monitor._nm.get_settings.return_value = {