import logging
from typing import Callable, Coroutine, Dict, List, Literal, Optional, TypedDict
from warnings import warn
from dbus_fast import Variant
from ...exc import BleakError
from ..scanner import AdvertisementData, AdvertisementDataCallback, BaseBleakScanner
from .advertisement_monitor import OrPatternLike
from .defs import Device1
from .manager import get_global_bluez_manager
from .utils import bdaddr_from_device_path
logger = logging.getLogger(__name__)
[docs]class BlueZDiscoveryFilters(TypedDict, total=False):
"""
Dictionary of arguments for the ``org.bluez.Adapter1.SetDiscoveryFilter``
D-Bus method.
https://github.com/bluez/bluez/blob/master/doc/adapter-api.txt
"""
UUIDs: List[str]
"""
Filter by service UUIDs, empty means match _any_ UUID.
Normally, the ``service_uuids`` argument of :class:`bleak.BleakScanner`
is used instead.
"""
RSSI: int
"""
RSSI threshold value.
"""
Pathloss: int
"""
Pathloss threshold value.
"""
Transport: str
"""
Transport parameter determines the type of scan.
This should not be used since it is required to be set to ``"le"``.
"""
DuplicateData: bool
"""
Disables duplicate detection of advertisement data.
This does not affect the ``Filter Duplicates`` parameter of the ``LE Set Scan Enable``
HCI command to the Bluetooth adapter!
Although the default value for BlueZ is ``True``, Bleak sets this to ``False`` by default.
"""
Discoverable: bool
"""
Make adapter discoverable while discovering,
if the adapter is already discoverable setting
this filter won't do anything.
"""
Pattern: str
"""
Discover devices where the pattern matches
either the prefix of the address or
device name which is convenient way to limited
the number of device objects created during a
discovery.
"""
[docs]class BlueZScannerArgs(TypedDict, total=False):
"""
:class:`BleakScanner` args that are specific to the BlueZ backend.
"""
filters: BlueZDiscoveryFilters
"""
Filters to pass to the adapter SetDiscoveryFilter D-Bus method.
Only used for active scanning.
"""
or_patterns: List[OrPatternLike]
"""
Or patterns to pass to the AdvertisementMonitor1 D-Bus interface.
Only used for passive scanning.
"""
[docs]class BleakScannerBlueZDBus(BaseBleakScanner):
"""The native Linux Bleak BLE Scanner.
For possible values for `filters`, see the parameters to the
``SetDiscoveryFilter`` method in the `BlueZ docs
<https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/adapter-api.txt?h=5.48&id=0d1e3b9c5754022c779da129025d493a198d49cf>`_
Args:
detection_callback:
Optional function that will be called each time a device is
discovered or advertising data has changed.
service_uuids:
Optional list of service UUIDs to filter on. Only advertisements
containing this advertising data will be received. Specifying this
also enables scanning while the screen is off on Android.
scanning_mode:
Set to ``"passive"`` to avoid the ``"active"`` scanning mode.
**bluez:
Dictionary of arguments specific to the BlueZ backend.
**adapter (str):
Bluetooth adapter to use for discovery.
"""
def __init__(
self,
detection_callback: Optional[AdvertisementDataCallback],
service_uuids: Optional[List[str]],
scanning_mode: Literal["active", "passive"],
*,
bluez: BlueZScannerArgs,
**kwargs,
):
super(BleakScannerBlueZDBus, self).__init__(detection_callback, service_uuids)
self._scanning_mode = scanning_mode
# kwarg "device" is for backwards compatibility
self._adapter: Optional[str] = kwargs.get("adapter", kwargs.get("device"))
# callback from manager for stopping scanning if it has been started
self._stop: Optional[Callable[[], Coroutine]] = None
# Discovery filters
self._filters: Dict[str, Variant] = {}
self._filters["Transport"] = Variant("s", "le")
self._filters["DuplicateData"] = Variant("b", False)
if self._service_uuids:
self._filters["UUIDs"] = Variant("as", self._service_uuids)
filters = kwargs.get("filters")
if filters is None:
filters = bluez.get("filters")
else:
warn(
"the 'filters' kwarg is deprecated, use 'bluez' kwarg instead",
FutureWarning,
stacklevel=2,
)
if filters is not None:
self.set_scanning_filter(filters=filters)
self._or_patterns = bluez.get("or_patterns")
if self._scanning_mode == "passive" and service_uuids:
logger.warning(
"service uuid filtering is not implemented for passive scanning, use bluez or_patterns as a workaround"
)
if self._scanning_mode == "passive" and not self._or_patterns:
raise BleakError("passive scanning mode requires bluez or_patterns")
[docs] async def start(self) -> None:
manager = await get_global_bluez_manager()
if self._adapter:
adapter_path = f"/org/bluez/{self._adapter}"
else:
adapter_path = manager.get_default_adapter()
self.seen_devices = {}
if self._scanning_mode == "passive":
self._stop = await manager.passive_scan(
adapter_path,
self._or_patterns,
self._handle_advertising_data,
self._handle_device_removed,
)
else:
self._stop = await manager.active_scan(
adapter_path,
self._filters,
self._handle_advertising_data,
self._handle_device_removed,
)
[docs] async def stop(self) -> None:
if self._stop:
# avoid reentrancy
stop, self._stop = self._stop, None
await stop()
[docs] def set_scanning_filter(self, **kwargs) -> None:
"""Sets OS level scanning filters for the BleakScanner.
For possible values for `filters`, see the parameters to the
``SetDiscoveryFilter`` method in the `BlueZ docs
<https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/adapter-api.txt?h=5.48&id=0d1e3b9c5754022c779da129025d493a198d49cf>`_
See variant types here: <https://python-dbus-next.readthedocs.io/en/latest/type-system/>
Keyword Args:
filters (dict): A dict of filters to be applied on discovery.
"""
for k, v in kwargs.get("filters", {}).items():
if k == "UUIDs":
self._filters[k] = Variant("as", v)
elif k == "RSSI":
self._filters[k] = Variant("n", v)
elif k == "Pathloss":
self._filters[k] = Variant("n", v)
elif k == "Transport":
self._filters[k] = Variant("s", v)
elif k == "DuplicateData":
self._filters[k] = Variant("b", v)
elif k == "Discoverable":
self._filters[k] = Variant("b", v)
elif k == "Pattern":
self._filters[k] = Variant("s", v)
else:
logger.warning("Filter '%s' is not currently supported." % k)
# Helper methods
def _handle_advertising_data(self, path: str, props: Device1) -> None:
"""
Handles advertising data received from the BlueZ manager instance.
Args:
path: The D-Bus object path of the device.
props: The D-Bus object properties of the device.
"""
# Get all the information wanted to pack in the advertisement data
_local_name = props.get("Name")
_manufacturer_data = {
k: bytes(v) for k, v in props.get("ManufacturerData", {}).items()
}
_service_data = {k: bytes(v) for k, v in props.get("ServiceData", {}).items()}
_service_uuids = props.get("UUIDs", [])
# Get tx power data
tx_power = props.get("TxPower")
# Pack the advertisement data
advertisement_data = AdvertisementData(
local_name=_local_name,
manufacturer_data=_manufacturer_data,
service_data=_service_data,
service_uuids=_service_uuids,
tx_power=tx_power,
rssi=props.get("RSSI", -127),
platform_data=(path, props),
)
device = self.create_or_update_device(
props["Address"],
props["Alias"],
{"path": path, "props": props},
advertisement_data,
)
self.call_detection_callbacks(device, advertisement_data)
def _handle_device_removed(self, device_path: str) -> None:
"""
Handles a device being removed from BlueZ.
"""
try:
bdaddr = bdaddr_from_device_path(device_path)
del self.seen_devices[bdaddr]
except KeyError:
# The device will not have been added to self.seen_devices if no
# advertising data was received, so this is expected to happen
# occasionally.
pass