Merge pull request #41 from hostcc/fix/block-notifications-from-wrong…

…-device

fix: Enforce host/device GUID when handling notifications/alerts

src/pyg90alarm/alarm.py

@@ -60,7 +60,8 @@
     G90Commands, REMOTE_PORT,
     REMOTE_TARGETED_DISCOVERY_PORT,
     LOCAL_TARGETED_DISCOVERY_PORT,
-    NOTIFICATIONS_PORT,
+    LOCAL_NOTIFICATIONS_HOST,
+    LOCAL_NOTIFICATIONS_PORT,
     G90ArmDisarmTypes,
 )
 from .base_cmd import (G90BaseCommand, G90BaseCommandData)
@@ -140,11 +141,14 @@ class G90Alarm(G90DeviceNotifications):
     # pylint: disable=too-many-instance-attributes,too-many-arguments
     def __init__(self, host: str, port: int = REMOTE_PORT,
                  reset_occupancy_interval: float = 3.0,
-                 notifications_host: str = '0.0.0.0',
-                 notifications_port: int = NOTIFICATIONS_PORT):
-        super().__init__(host=notifications_host, port=notifications_port)
-        self._host = host
-        self._port = port
+                 notifications_local_host: str = LOCAL_NOTIFICATIONS_HOST,
+                 notifications_local_port: int = LOCAL_NOTIFICATIONS_PORT):
+        super().__init__(
+            local_host=notifications_local_host,
+            local_port=notifications_local_port
+        )
+        self._host: str = host
+        self._port: int = port
         self._sensors: List[G90Sensor] = []
         self._devices: List[G90Device] = []
         self._notifications: Optional[G90DeviceNotifications] = None
@@ -336,7 +340,9 @@ async def get_host_info(self) -> G90HostInfo:
         :return: Device information
         """
         res = await self.command(G90Commands.GETHOSTINFO)
-        return G90HostInfo(*res)
+        info = G90HostInfo(*res)
+        self.device_id = info.host_guid
+        return info
 
     @property
     async def host_status(self) -> G90HostStatus:
@@ -813,7 +819,7 @@ async def _simulate_alerts_from_history(
                         # code as alert, as if it came from the device and its
                         # notifications port
                         self._handle_alert(
-                            (self._host, self._notifications_port),
+                            (self._host, self._notifications_local_port),
                             item.as_device_alert()
                         )
 

src/pyg90alarm/const.py

@@ -28,7 +28,8 @@
 REMOTE_PORT = 12368
 REMOTE_TARGETED_DISCOVERY_PORT = 12900
 LOCAL_TARGETED_DISCOVERY_PORT = 12901
-NOTIFICATIONS_PORT = 12901
+LOCAL_NOTIFICATIONS_HOST = '0.0.0.0'
+LOCAL_NOTIFICATIONS_PORT = 12901
 
 CMD_PAGE_SIZE = 10
 

src/pyg90alarm/device_notifications.py

@@ -41,7 +41,6 @@
     G90AlertStates,
 )
 
-
 _LOGGER = logging.getLogger(__name__)
 
 
@@ -107,12 +106,29 @@ class G90DeviceAlert:  # pylint: disable=too-many-instance-attributes
 class G90DeviceNotifications(DatagramProtocol):
     """
     Implements support for notifications/alerts sent by alarm panel.
+
+    There is a basic check to ensure only notifications/alerts from the correct
+    device are processed - the check uses the host and port of the device, and
+    the device ID (GUID) that is set by the ancestor class that implements the
+    commands (e.g. :class:`G90Alarm`). The latter to work correctly needs a
+    command to be performed first, one that fetches device GUID and then stores
+    it using :attr:`.device_id` (e.g. :meth:`G90Alarm.get_host_info`).
     """
-    def __init__(self, port: int, host: str):
+    def __init__(self, local_port: int, local_host: str):
         # pylint: disable=too-many-arguments
         self._notification_transport: Optional[BaseTransport] = None
-        self._notifications_host = host
-        self._notifications_port = port
+        self._notifications_local_host = local_host
+        self._notifications_local_port = local_port
+        # Host/port of the device is configured to communicating via commands.
+        # Inteded to validate if notifications/alert are received from the
+        # correct device.
+        self._host: Optional[str] = None
+        self._port: Optional[int] = None
+        # Same but for device ID (GUID) - the notifications logic uses it to
+        # perform validation, but doesn't set it from messages received (it
+        # will diminish the purpose of the validation, should be done by an
+        # ancestor class).
+        self._device_id: Optional[str] = None
 
     def _handle_notification(
         self, addr: Tuple[str, int], notification: G90Notification
@@ -145,6 +161,15 @@ def _handle_notification(
     def _handle_alert(
         self, addr: Tuple[str, int], alert: G90DeviceAlert
     ) -> None:
+        # Stop processing when alert is received from the device with different
+        # GUID
+        if self.device_id and alert.device_id != self.device_id:
+            _LOGGER.error(
+                "Received alert from wrong device: expected '%s', got '%s'",
+                self.device_id, alert.device_id
+            )
+            return
+
         if alert.type == G90AlertTypes.DOOR_OPEN_CLOSE:
             if alert.state in (
                 G90AlertStates.DOOR_OPEN, G90AlertStates.DOOR_CLOSE
@@ -219,10 +244,17 @@ def connection_lost(self, exc: Optional[Exception]) -> None:
     def datagram_received(  # pylint:disable=R0911
         self, data: bytes, addr: Tuple[str, int]
     ) -> None:
-
         """
-        Invoked from datagram is received from the device.
+        Invoked when datagram is received from the device.
         """
+        if self._host and self._host != addr[0]:
+            _LOGGER.error(
+                "Received notification/alert from wrong host '%s',"
+                " expected from '%s'",
+                addr[0], self._host
+            )
+            return
+
         s_data = data.decode('utf-8')
         if not s_data.endswith('\0'):
             _LOGGER.error('Missing end marker in data')
@@ -304,13 +336,13 @@ async def listen(self) -> None:
             loop = asyncio.get_event_loop()
 
         _LOGGER.debug('Creating UDP endpoint for %s:%s',
-                      self._notifications_host,
-                      self._notifications_port)
+                      self._notifications_local_host,
+                      self._notifications_local_port)
         (self._notification_transport,
          _protocol) = await loop.create_datagram_endpoint(
             lambda: self,
             local_addr=(
-                self._notifications_host, self._notifications_port
+                self._notifications_local_host, self._notifications_local_port
             ))
 
     @property
@@ -328,3 +360,17 @@ def close(self) -> None:
             _LOGGER.debug('No longer listening for device notifications')
             self._notification_transport.close()
             self._notification_transport = None
+
+    @property
+    def device_id(self) -> Optional[str]:
+        """
+        The ID (GUID) of the panel being communicated with thru commands.
+
+        Available when any panel command receives it from the device
+        (:meth:`G90Alarm.get_host_info` currently).
+        """
+        return self._device_id
+
+    @device_id.setter
+    def device_id(self, device_id: str) -> None:
+        self._device_id = device_id

tests/test_alarm.py

@@ -308,8 +308,8 @@ async def test_sensor_event(mock_device: DeviceMock) -> None:
     reset_interval = 0.5
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
                    reset_occupancy_interval=reset_interval,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
 
     sensors = await g90.get_sensors()
     prop_sensors = await g90.sensors
@@ -352,8 +352,8 @@ async def test_sensor_low_battery_event(mock_device: DeviceMock) -> None:
     Tests for sensor low battery callback.
     """
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
 
     sensors = await g90.get_sensors()
     prop_sensors = await g90.sensors
@@ -401,8 +401,8 @@ async def test_armdisarm_callback(mock_device: DeviceMock) -> None:
     armdisarm_cb = MagicMock()
     armdisarm_cb.side_effect = lambda *args: future.set_result(True)
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
     g90.armdisarm_callback = armdisarm_cb
     await g90.listen_device_notifications()
     await mock_device.send_next_notification()
@@ -434,8 +434,8 @@ async def test_door_open_close_callback(mock_device: DeviceMock) -> None:
     door_open_close_cb.side_effect = lambda *args: future.set_result(True)
 
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
     g90.door_open_close_callback = door_open_close_cb
 
     # Simulate two device alerts - for opening (this one) and then closing the
@@ -492,8 +492,8 @@ async def test_alarm_callback(mock_device: DeviceMock) -> None:
     alarm_cb.side_effect = lambda *args: future.set_result(True)
 
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
     sensors = await g90.get_sensors()
     # Set extra data for the 1st sensor
     sensors[0].extra_data = 'Dummy extra data'
@@ -753,8 +753,8 @@ async def test_sms_alert_when_armed(mock_device: DeviceMock) -> None:
     armdisarm_cb = MagicMock()
     armdisarm_cb.side_effect = lambda *args: future.set_result(True)
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
     g90.armdisarm_callback = armdisarm_cb
     g90.sms_alert_when_armed = True
     await g90.listen_device_notifications()
@@ -787,8 +787,8 @@ async def test_sms_alert_when_disarmed(mock_device: DeviceMock) -> None:
     armdisarm_cb = MagicMock()
     armdisarm_cb.side_effect = lambda *args: future.set_result(True)
     g90 = G90Alarm(host=mock_device.host, port=mock_device.port,
-                   notifications_host=mock_device.notification_host,
-                   notifications_port=mock_device.notification_port)
+                   notifications_local_host=mock_device.notification_host,
+                   notifications_local_port=mock_device.notification_port)
     g90.armdisarm_callback = armdisarm_cb
     g90.sms_alert_when_armed = True
     await g90.listen_device_notifications()