Use AuthAnnonymous() when connecting to DBus over TCP

DBus-next defaults to using AuthExternal() when autenticating but this only works when we are working on the same machine.

Tested on Ubuntu 21.10.

bleak/backends/bluezdbus/client.py

@@ -30,7 +30,7 @@
 from .characteristic import BleakGATTCharacteristicBlueZDBus
 from .manager import get_global_bluez_manager
 from .scanner import BleakScannerBlueZDBus
-from .utils import assert_reply, get_dbus_authenticator
+from .utils import assert_reply, get_dbus_authenticator, should_negotiate_unix_fd
 from .version import BlueZFeatures
 
 logger = logging.getLogger(__name__)
@@ -144,7 +144,7 @@ async def connect(self, dangerous_use_bleak_cache: bool = False, **kwargs) -> bo
                 # BlueZ quirk where notifications are automatically enabled on reconnect.
                 self._bus = await MessageBus(
                     bus_type=BusType.SYSTEM,
-                    negotiate_unix_fd=True,
+                    negotiate_unix_fd=should_negotiate_unix_fd(),
                     auth=get_dbus_authenticator(),
                 ).connect()
 

bleak/backends/bluezdbus/utils.py

@@ -2,7 +2,7 @@
 import os
 import re
 
-from dbus_fast.auth import AuthExternal
+from dbus_fast.auth import AuthExternal, AuthAnnonymous
 from dbus_fast.constants import MessageType
 from dbus_fast.message import Message
 
@@ -57,5 +57,14 @@ def get_dbus_authenticator():
     auth = None
     if uid is not None:
         auth = AuthExternal(uid=uid)
+
+    if 'tcp' in os.environ.get('DBUS_SYSTEM_BUS_ADDRESS', None):
+        auth=AuthAnnonymous()
 
     return auth
+
+def should_negotiate_unix_fd():
+    if 'tcp' in os.environ.get('DBUS_SYSTEM_BUS_ADDRESS', None):
+        return False
+    else:
+        return True