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c2959dadb470b32075173e151aaf34b998802155
bumble_fork/bumble/sdp.py
Gilles Boccon-Gibod c2959dadb4 formatting and linting automation 
Squashed commits:
[cd479ba] formatting and linting automation
[7fbfabb] formatting and linting automation
[c4f9505] fix after rebase
[f506ad4] rename job
[441d517] update doc (+7 squashed commits)
[2e1b416] fix invoke and github action
[6ae5bb4] doc for git blame
[44b5461] add GitHub action
[b07474f] add docs
[4cd9a6f] more linter fixes
[db71901] wip
[540dc88] wip
2022-12-15 23:07:17 -08:00

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# Copyright 2021-2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# -----------------------------------------------------------------------------
# Imports
# -----------------------------------------------------------------------------
import logging
import struct
from colors import color
import colors
from . import core
from .core import InvalidStateError
from .hci import HCI_Object, name_or_number, key_with_value
# -----------------------------------------------------------------------------
# Logging
# -----------------------------------------------------------------------------
logger = logging.getLogger(__name__)
# -----------------------------------------------------------------------------
# Constants
# -----------------------------------------------------------------------------
# fmt: off
# pylint: disable=line-too-long
SDP_CONTINUATION_WATCHDOG = 64 # Maximum number of continuations we're willing to do
SDP_PSM = 0x0001
SDP_ERROR_RESPONSE = 0x01
SDP_SERVICE_SEARCH_REQUEST = 0x02
SDP_SERVICE_SEARCH_RESPONSE = 0x03
SDP_SERVICE_ATTRIBUTE_REQUEST = 0x04
SDP_SERVICE_ATTRIBUTE_RESPONSE = 0x05
SDP_SERVICE_SEARCH_ATTRIBUTE_REQUEST = 0x06
SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE = 0x07
SDP_PDU_NAMES = {
SDP_ERROR_RESPONSE: 'SDP_ERROR_RESPONSE',
SDP_SERVICE_SEARCH_REQUEST: 'SDP_SERVICE_SEARCH_REQUEST',
SDP_SERVICE_SEARCH_RESPONSE: 'SDP_SERVICE_SEARCH_RESPONSE',
SDP_SERVICE_ATTRIBUTE_REQUEST: 'SDP_SERVICE_ATTRIBUTE_REQUEST',
SDP_SERVICE_ATTRIBUTE_RESPONSE: 'SDP_SERVICE_ATTRIBUTE_RESPONSE',
SDP_SERVICE_SEARCH_ATTRIBUTE_REQUEST: 'SDP_SERVICE_SEARCH_ATTRIBUTE_REQUEST',
SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE: 'SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE'
}
SDP_INVALID_SDP_VERSION_ERROR = 0x0001
SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR = 0x0002
SDP_INVALID_REQUEST_SYNTAX_ERROR = 0x0003
SDP_INVALID_PDU_SIZE_ERROR = 0x0004
SDP_INVALID_CONTINUATION_STATE_ERROR = 0x0005
SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR = 0x0006
SDP_ERROR_NAMES = {
SDP_INVALID_SDP_VERSION_ERROR: 'SDP_INVALID_SDP_VERSION_ERROR',
SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR: 'SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR',
SDP_INVALID_REQUEST_SYNTAX_ERROR: 'SDP_INVALID_REQUEST_SYNTAX_ERROR',
SDP_INVALID_PDU_SIZE_ERROR: 'SDP_INVALID_PDU_SIZE_ERROR',
SDP_INVALID_CONTINUATION_STATE_ERROR: 'SDP_INVALID_CONTINUATION_STATE_ERROR',
SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR: 'SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR'
}
SDP_SERVICE_NAME_ATTRIBUTE_ID_OFFSET = 0x0000
SDP_SERVICE_DESCRIPTION_ATTRIBUTE_ID_OFFSET = 0x0001
SDP_PROVIDER_NAME_ATTRIBUTE_ID_OFFSET = 0x0002
SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID = 0X0000
SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID = 0X0001
SDP_SERVICE_RECORD_STATE_ATTRIBUTE_ID = 0X0002
SDP_SERVICE_ID_ATTRIBUTE_ID = 0X0003
SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID = 0X0004
SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID = 0X0005
SDP_LANGUAGE_BASE_ATTRIBUTE_ID_LIST_ATTRIBUTE_ID = 0X0006
SDP_SERVICE_INFO_TIME_TO_LIVE_ATTRIBUTE_ID = 0X0007
SDP_SERVICE_AVAILABILITY_ATTRIBUTE_ID = 0X0008
SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID = 0X0009
SDP_DOCUMENTATION_URL_ATTRIBUTE_ID = 0X000A
SDP_CLIENT_EXECUTABLE_URL_ATTRIBUTE_ID = 0X000B
SDP_ICON_URL_ATTRIBUTE_ID = 0X000C
SDP_ADDITIONAL_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID = 0X000D
SDP_ATTRIBUTE_ID_NAMES = {
SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID: 'SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID',
SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID: 'SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID',
SDP_SERVICE_RECORD_STATE_ATTRIBUTE_ID: 'SDP_SERVICE_RECORD_STATE_ATTRIBUTE_ID',
SDP_SERVICE_ID_ATTRIBUTE_ID: 'SDP_SERVICE_ID_ATTRIBUTE_ID',
SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID: 'SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID',
SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID: 'SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID',
SDP_LANGUAGE_BASE_ATTRIBUTE_ID_LIST_ATTRIBUTE_ID: 'SDP_LANGUAGE_BASE_ATTRIBUTE_ID_LIST_ATTRIBUTE_ID',
SDP_SERVICE_INFO_TIME_TO_LIVE_ATTRIBUTE_ID: 'SDP_SERVICE_INFO_TIME_TO_LIVE_ATTRIBUTE_ID',
SDP_SERVICE_AVAILABILITY_ATTRIBUTE_ID: 'SDP_SERVICE_AVAILABILITY_ATTRIBUTE_ID',
SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID: 'SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID',
SDP_DOCUMENTATION_URL_ATTRIBUTE_ID: 'SDP_DOCUMENTATION_URL_ATTRIBUTE_ID',
SDP_CLIENT_EXECUTABLE_URL_ATTRIBUTE_ID: 'SDP_CLIENT_EXECUTABLE_URL_ATTRIBUTE_ID',
SDP_ICON_URL_ATTRIBUTE_ID: 'SDP_ICON_URL_ATTRIBUTE_ID',
SDP_ADDITIONAL_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID: 'SDP_ADDITIONAL_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID'
}
SDP_PUBLIC_BROWSE_ROOT = core.UUID.from_16_bits(0x1002, 'PublicBrowseRoot')
# To be used in searches where an attribute ID list allows a range to be specified
SDP_ALL_ATTRIBUTES_RANGE = (0x0000FFFF, 4) # Express this as tuple so we can convey the desired encoding size
# fmt: on
# pylint: enable=line-too-long
# pylint: disable=invalid-name
# -----------------------------------------------------------------------------
class DataElement:
NIL = 0
UNSIGNED_INTEGER = 1
SIGNED_INTEGER = 2
UUID = 3
TEXT_STRING = 4
BOOLEAN = 5
SEQUENCE = 6
ALTERNATIVE = 7
URL = 8
TYPE_NAMES = {
NIL: 'NIL',
UNSIGNED_INTEGER: 'UNSIGNED_INTEGER',
SIGNED_INTEGER: 'SIGNED_INTEGER',
UUID: 'UUID',
TEXT_STRING: 'TEXT_STRING',
BOOLEAN: 'BOOLEAN',
SEQUENCE: 'SEQUENCE',
ALTERNATIVE: 'ALTERNATIVE',
URL: 'URL',
}
type_constructors = {
NIL: lambda x: DataElement(DataElement.NIL, None),
UNSIGNED_INTEGER: lambda x, y: DataElement(
DataElement.UNSIGNED_INTEGER,
DataElement.unsigned_integer_from_bytes(x),
value_size=y,
),
SIGNED_INTEGER: lambda x, y: DataElement(
DataElement.SIGNED_INTEGER,
DataElement.signed_integer_from_bytes(x),
value_size=y,
),
UUID: lambda x: DataElement(
DataElement.UUID, core.UUID.from_bytes(bytes(reversed(x)))
),
TEXT_STRING: lambda x: DataElement(DataElement.TEXT_STRING, x.decode('utf8')),
BOOLEAN: lambda x: DataElement(DataElement.BOOLEAN, x[0] == 1),
SEQUENCE: lambda x: DataElement(
DataElement.SEQUENCE, DataElement.list_from_bytes(x)
),
ALTERNATIVE: lambda x: DataElement(
DataElement.ALTERNATIVE, DataElement.list_from_bytes(x)
),
URL: lambda x: DataElement(DataElement.URL, x.decode('utf8')),
}
def __init__(self, element_type, value, value_size=None):
self.type = element_type
self.value = value
self.value_size = value_size
# Used as a cache when parsing from bytes so we can emit a byte-for-byte replica
self.bytes = None
if element_type in (DataElement.UNSIGNED_INTEGER, DataElement.SIGNED_INTEGER):
if value_size is None:
raise ValueError('integer types must have a value size specified')
@staticmethod
def nil():
return DataElement(DataElement.NIL, None)
@staticmethod
def unsigned_integer(value, value_size):
return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size)
@staticmethod
def unsigned_integer_8(value):
return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=1)
@staticmethod
def unsigned_integer_16(value):
return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=2)
@staticmethod
def unsigned_integer_32(value):
return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=4)
@staticmethod
def signed_integer(value, value_size):
return DataElement(DataElement.SIGNED_INTEGER, value, value_size)
@staticmethod
def signed_integer_8(value):
return DataElement(DataElement.SIGNED_INTEGER, value, value_size=1)
@staticmethod
def signed_integer_16(value):
return DataElement(DataElement.SIGNED_INTEGER, value, value_size=2)
@staticmethod
def signed_integer_32(value):
return DataElement(DataElement.SIGNED_INTEGER, value, value_size=4)
@staticmethod
def uuid(value):
return DataElement(DataElement.UUID, value)
@staticmethod
def text_string(value):
return DataElement(DataElement.TEXT_STRING, value)
@staticmethod
def boolean(value):
return DataElement(DataElement.BOOLEAN, value)
@staticmethod
def sequence(value):
return DataElement(DataElement.SEQUENCE, value)
@staticmethod
def alternative(value):
return DataElement(DataElement.ALTERNATIVE, value)
@staticmethod
def url(value):
return DataElement(DataElement.URL, value)
@staticmethod
def unsigned_integer_from_bytes(data):
if len(data) == 1:
return data[0]
if len(data) == 2:
return struct.unpack('>H', data)[0]
if len(data) == 4:
return struct.unpack('>I', data)[0]
if len(data) == 8:
return struct.unpack('>Q', data)[0]
raise ValueError(f'invalid integer length {len(data)}')
@staticmethod
def signed_integer_from_bytes(data):
if len(data) == 1:
return struct.unpack('b', data)[0]
if len(data) == 2:
return struct.unpack('>h', data)[0]
if len(data) == 4:
return struct.unpack('>i', data)[0]
if len(data) == 8:
return struct.unpack('>q', data)[0]
raise ValueError(f'invalid integer length {len(data)}')
@staticmethod
def list_from_bytes(data):
elements = []
while data:
element = DataElement.from_bytes(data)
elements.append(element)
data = data[len(bytes(element)) :]
return elements
@staticmethod
def parse_from_bytes(data, offset):
element = DataElement.from_bytes(data[offset:])
return offset + len(bytes(element)), element
@staticmethod
def from_bytes(data):
element_type = data[0] >> 3
size_index = data[0] & 7
value_offset = 0
if size_index == 0:
if element_type == DataElement.NIL:
value_size = 0
else:
value_size = 1
elif size_index == 1:
value_size = 2
elif size_index == 2:
value_size = 4
elif size_index == 3:
value_size = 8
elif size_index == 4:
value_size = 16
elif size_index == 5:
value_size = data[1]
value_offset = 1
elif size_index == 6:
value_size = struct.unpack('>H', data[1:3])[0]
value_offset = 2
else: # size_index == 7
value_size = struct.unpack('>I', data[1:5])[0]
value_offset = 4
value_data = data[1 + value_offset : 1 + value_offset + value_size]
constructor = DataElement.type_constructors.get(element_type)
if constructor:
if element_type in (
DataElement.UNSIGNED_INTEGER,
DataElement.SIGNED_INTEGER,
):
result = constructor(value_data, value_size)
else:
result = constructor(value_data)
else:
result = DataElement(element_type, value_data)
result.bytes = data[
: 1 + value_offset + value_size
] # Keep a copy so we can re-serialize to an exact replica
return result
def to_bytes(self):
return bytes(self)
def __bytes__(self):
# Return early if we have a cache
if self.bytes:
return self.bytes
if self.type == DataElement.NIL:
data = b''
elif self.type == DataElement.UNSIGNED_INTEGER:
if self.value < 0:
raise ValueError('UNSIGNED_INTEGER cannot be negative')
if self.value_size == 1:
data = struct.pack('B', self.value)
elif self.value_size == 2:
data = struct.pack('>H', self.value)
elif self.value_size == 4:
data = struct.pack('>I', self.value)
elif self.value_size == 8:
data = struct.pack('>Q', self.value)
else:
raise ValueError('invalid value_size')
elif self.type == DataElement.SIGNED_INTEGER:
if self.value_size == 1:
data = struct.pack('b', self.value)
elif self.value_size == 2:
data = struct.pack('>h', self.value)
elif self.value_size == 4:
data = struct.pack('>i', self.value)
elif self.value_size == 8:
data = struct.pack('>q', self.value)
else:
raise ValueError('invalid value_size')
elif self.type == DataElement.UUID:
data = bytes(reversed(bytes(self.value)))
elif self.type in (DataElement.TEXT_STRING, DataElement.URL):
data = self.value.encode('utf8')
elif self.type == DataElement.BOOLEAN:
data = bytes([1 if self.value else 0])
elif self.type in (DataElement.SEQUENCE, DataElement.ALTERNATIVE):
data = b''.join([bytes(element) for element in self.value])
else:
data = self.value
size = len(data)
size_bytes = b''
if self.type == DataElement.NIL:
if size != 0:
raise ValueError('NIL must be empty')
size_index = 0
elif self.type in (
DataElement.UNSIGNED_INTEGER,
DataElement.SIGNED_INTEGER,
DataElement.UUID,
):
if size <= 1:
size_index = 0
elif size == 2:
size_index = 1
elif size == 4:
size_index = 2
elif size == 8:
size_index = 3
elif size == 16:
size_index = 4
else:
raise ValueError('invalid data size')
elif self.type in (
DataElement.TEXT_STRING,
DataElement.SEQUENCE,
DataElement.ALTERNATIVE,
DataElement.URL,
):
if size <= 0xFF:
size_index = 5
size_bytes = bytes([size])
elif size <= 0xFFFF:
size_index = 6
size_bytes = struct.pack('>H', size)
elif size <= 0xFFFFFFFF:
size_index = 7
size_bytes = struct.pack('>I', size)
else:
raise ValueError('invalid data size')
elif self.type == DataElement.BOOLEAN:
if size != 1:
raise ValueError('boolean must be 1 byte')
size_index = 0
self.bytes = bytes([self.type << 3 | size_index]) + size_bytes + data
return self.bytes
def to_string(self, pretty=False, indentation=0):
prefix = ' ' * indentation
type_name = name_or_number(self.TYPE_NAMES, self.type)
if self.type == DataElement.NIL:
value_string = ''
elif self.type in (DataElement.SEQUENCE, DataElement.ALTERNATIVE):
container_separator = '\n' if pretty else ''
element_separator = '\n' if pretty else ','
elements = [
element.to_string(pretty, indentation + 1 if pretty else 0)
for element in self.value
]
value_string = (
f'[{container_separator}'
f'{element_separator.join(elements)}'
f'{container_separator}{prefix}]'
)
elif self.type in (DataElement.UNSIGNED_INTEGER, DataElement.SIGNED_INTEGER):
value_string = f'{self.value}#{self.value_size}'
elif isinstance(self.value, DataElement):
value_string = self.value.to_string(pretty, indentation)
else:
value_string = str(self.value)
return f'{prefix}{type_name}({value_string})'
def __str__(self):
return self.to_string()
# -----------------------------------------------------------------------------
class ServiceAttribute:
def __init__(self, attribute_id, value):
self.id = attribute_id
self.value = value
@staticmethod
def list_from_data_elements(elements):
attribute_list = []
for i in range(0, len(elements) // 2):
attribute_id, attribute_value = elements[2 * i : 2 * (i + 1)]
if attribute_id.type != DataElement.UNSIGNED_INTEGER:
logger.warning('attribute ID element is not an integer')
continue
attribute_list.append(ServiceAttribute(attribute_id.value, attribute_value))
return attribute_list
@staticmethod
def find_attribute_in_list(attribute_list, attribute_id):
return next(
(
attribute.value
for attribute in attribute_list
if attribute.id == attribute_id
),
None,
)
@staticmethod
def id_name(id_code):
return name_or_number(SDP_ATTRIBUTE_ID_NAMES, id_code)
@staticmethod
def is_uuid_in_value(uuid, value):
# Find if a uuid matches a value, either directly or recursing into sequences
if value.type == DataElement.UUID:
return value.value == uuid
if value.type == DataElement.SEQUENCE:
for element in value.value:
if ServiceAttribute.is_uuid_in_value(uuid, element):
return True
return False
return False
def to_string(self, with_colors=False):
if with_colors:
return (
f'Attribute(id={colors.color(self.id_name(self.id),"magenta")},'
f'value={self.value})'
)
return f'Attribute(id={self.id_name(self.id)},value={self.value})'
def __str__(self):
return self.to_string()
# -----------------------------------------------------------------------------
class SDP_PDU:
'''
See Bluetooth spec @ Vol 3, Part B - 4.2 PROTOCOL DATA UNIT FORMAT
'''
sdp_pdu_classes = {}
name = None
pdu_id = 0
@staticmethod
def from_bytes(pdu):
pdu_id, transaction_id, _parameters_length = struct.unpack_from('>BHH', pdu, 0)
cls = SDP_PDU.sdp_pdu_classes.get(pdu_id)
if cls is None:
instance = SDP_PDU(pdu)
instance.name = SDP_PDU.pdu_name(pdu_id)
instance.pdu_id = pdu_id
instance.transaction_id = transaction_id
return instance
self = cls.__new__(cls)
SDP_PDU.__init__(self, pdu, transaction_id)
if hasattr(self, 'fields'):
self.init_from_bytes(pdu, 5)
return self
@staticmethod
def parse_service_record_handle_list_preceded_by_count(data, offset):
count = struct.unpack_from('>H', data, offset - 2)[0]
handle_list = [
struct.unpack_from('>I', data, offset + x * 4)[0] for x in range(count)
]
return offset + count * 4, handle_list
@staticmethod
def parse_bytes_preceded_by_length(data, offset):
length = struct.unpack_from('>H', data, offset - 2)[0]
return offset + length, data[offset : offset + length]
@staticmethod
def error_name(error_code):
return name_or_number(SDP_ERROR_NAMES, error_code)
@staticmethod
def pdu_name(code):
return name_or_number(SDP_PDU_NAMES, code)
@staticmethod
def subclass(fields):
def inner(cls):
name = cls.__name__
# add a _ character before every uppercase letter, except the SDP_ prefix
location = len(name) - 1
while location > 4:
if not name[location].isupper():
location -= 1
continue
name = name[:location] + '_' + name[location:]
location -= 1
cls.name = name.upper()
cls.pdu_id = key_with_value(SDP_PDU_NAMES, cls.name)
if cls.pdu_id is None:
raise KeyError(f'PDU name {cls.name} not found in SDP_PDU_NAMES')
cls.fields = fields
# Register a factory for this class
SDP_PDU.sdp_pdu_classes[cls.pdu_id] = cls
return cls
return inner
def __init__(self, pdu=None, transaction_id=0, **kwargs):
if hasattr(self, 'fields') and kwargs:
HCI_Object.init_from_fields(self, self.fields, kwargs)
if pdu is None:
parameters = HCI_Object.dict_to_bytes(kwargs, self.fields)
pdu = (
struct.pack('>BHH', self.pdu_id, transaction_id, len(parameters))
+ parameters
)
self.pdu = pdu
self.transaction_id = transaction_id
def init_from_bytes(self, pdu, offset):
return HCI_Object.init_from_bytes(self, pdu, offset, self.fields)
def to_bytes(self):
return self.pdu
def __bytes__(self):
return self.to_bytes()
def __str__(self):
result = f'{color(self.name, "blue")} [TID={self.transaction_id}]'
if fields := getattr(self, 'fields', None):
result += ':\n' + HCI_Object.format_fields(self.__dict__, fields, ' ')
elif len(self.pdu) > 1:
result += f': {self.pdu.hex()}'
return result
# -----------------------------------------------------------------------------
@SDP_PDU.subclass([('error_code', {'size': 2, 'mapper': SDP_PDU.error_name})])
class SDP_ErrorResponse(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.4.1 SDP_ErrorResponse PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('service_search_pattern', DataElement.parse_from_bytes),
('maximum_service_record_count', '>2'),
('continuation_state', '*'),
]
)
class SDP_ServiceSearchRequest(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.5.1 SDP_ServiceSearchRequest PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('total_service_record_count', '>2'),
('current_service_record_count', '>2'),
(
'service_record_handle_list',
SDP_PDU.parse_service_record_handle_list_preceded_by_count,
),
('continuation_state', '*'),
]
)
class SDP_ServiceSearchResponse(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.5.2 SDP_ServiceSearchResponse PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('service_record_handle', '>4'),
('maximum_attribute_byte_count', '>2'),
('attribute_id_list', DataElement.parse_from_bytes),
('continuation_state', '*'),
]
)
class SDP_ServiceAttributeRequest(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.6.1 SDP_ServiceAttributeRequest PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('attribute_list_byte_count', '>2'),
('attribute_list', SDP_PDU.parse_bytes_preceded_by_length),
('continuation_state', '*'),
]
)
class SDP_ServiceAttributeResponse(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.6.2 SDP_ServiceAttributeResponse PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('service_search_pattern', DataElement.parse_from_bytes),
('maximum_attribute_byte_count', '>2'),
('attribute_id_list', DataElement.parse_from_bytes),
('continuation_state', '*'),
]
)
class SDP_ServiceSearchAttributeRequest(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.7.1 SDP_ServiceSearchAttributeRequest PDU
'''
# -----------------------------------------------------------------------------
@SDP_PDU.subclass(
[
('attribute_lists_byte_count', '>2'),
('attribute_lists', SDP_PDU.parse_bytes_preceded_by_length),
('continuation_state', '*'),
]
)
class SDP_ServiceSearchAttributeResponse(SDP_PDU):
'''
See Bluetooth spec @ Vol 3, Part B - 4.7.2 SDP_ServiceSearchAttributeResponse PDU
'''
# -----------------------------------------------------------------------------
class Client:
def __init__(self, device):
self.device = device
self.pending_request = None
self.channel = None
async def connect(self, connection):
result = await self.device.l2cap_channel_manager.connect(connection, SDP_PSM)
self.channel = result
async def disconnect(self):
if self.channel:
await self.channel.disconnect()
self.channel = None
async def search_services(self, uuids):
if self.pending_request is not None:
raise InvalidStateError('request already pending')
service_search_pattern = DataElement.sequence(
[DataElement.uuid(uuid) for uuid in uuids]
)
# Request and accumulate until there's no more continuation
service_record_handle_list = []
continuation_state = bytes([0])
watchdog = SDP_CONTINUATION_WATCHDOG
while watchdog > 0:
response_pdu = await self.channel.send_request(
SDP_ServiceSearchRequest(
transaction_id=0, # Transaction ID TODO: pick a real value
service_search_pattern=service_search_pattern,
maximum_service_record_count=0xFFFF,
continuation_state=continuation_state,
)
)
response = SDP_PDU.from_bytes(response_pdu)
logger.debug(f'<<< Response: {response}')
service_record_handle_list += response.service_record_handle_list
continuation_state = response.continuation_state
if len(continuation_state) == 1 and continuation_state[0] == 0:
break
logger.debug(f'continuation: {continuation_state.hex()}')
watchdog -= 1
return service_record_handle_list
async def search_attributes(self, uuids, attribute_ids):
if self.pending_request is not None:
raise InvalidStateError('request already pending')
service_search_pattern = DataElement.sequence(
[DataElement.uuid(uuid) for uuid in uuids]
)
attribute_id_list = DataElement.sequence(
[
DataElement.unsigned_integer(
attribute_id[0], value_size=attribute_id[1]
)
if isinstance(attribute_id, tuple)
else DataElement.unsigned_integer_16(attribute_id)
for attribute_id in attribute_ids
]
)
# Request and accumulate until there's no more continuation
accumulator = b''
continuation_state = bytes([0])
watchdog = SDP_CONTINUATION_WATCHDOG
while watchdog > 0:
response_pdu = await self.channel.send_request(
SDP_ServiceSearchAttributeRequest(
transaction_id=0, # Transaction ID TODO: pick a real value
service_search_pattern=service_search_pattern,
maximum_attribute_byte_count=0xFFFF,
attribute_id_list=attribute_id_list,
continuation_state=continuation_state,
)
)
response = SDP_PDU.from_bytes(response_pdu)
logger.debug(f'<<< Response: {response}')
accumulator += response.attribute_lists
continuation_state = response.continuation_state
if len(continuation_state) == 1 and continuation_state[0] == 0:
break
logger.debug(f'continuation: {continuation_state.hex()}')
watchdog -= 1
# Parse the result into attribute lists
attribute_lists_sequences = DataElement.from_bytes(accumulator)
if attribute_lists_sequences.type != DataElement.SEQUENCE:
logger.warning('unexpected data type')
return []
return [
ServiceAttribute.list_from_data_elements(sequence.value)
for sequence in attribute_lists_sequences.value
if sequence.type == DataElement.SEQUENCE
]
async def get_attributes(self, service_record_handle, attribute_ids):
if self.pending_request is not None:
raise InvalidStateError('request already pending')
attribute_id_list = DataElement.sequence(
[
DataElement.unsigned_integer(
attribute_id[0], value_size=attribute_id[1]
)
if isinstance(attribute_id, tuple)
else DataElement.unsigned_integer_16(attribute_id)
for attribute_id in attribute_ids
]
)
# Request and accumulate until there's no more continuation
accumulator = b''
continuation_state = bytes([0])
watchdog = SDP_CONTINUATION_WATCHDOG
while watchdog > 0:
response_pdu = await self.channel.send_request(
SDP_ServiceAttributeRequest(
transaction_id=0, # Transaction ID TODO: pick a real value
service_record_handle=service_record_handle,
maximum_attribute_byte_count=0xFFFF,
attribute_id_list=attribute_id_list,
continuation_state=continuation_state,
)
)
response = SDP_PDU.from_bytes(response_pdu)
logger.debug(f'<<< Response: {response}')
accumulator += response.attribute_list
continuation_state = response.continuation_state
if len(continuation_state) == 1 and continuation_state[0] == 0:
break
logger.debug(f'continuation: {continuation_state.hex()}')
watchdog -= 1
# Parse the result into a list of attributes
attribute_list_sequence = DataElement.from_bytes(accumulator)
if attribute_list_sequence.type != DataElement.SEQUENCE:
logger.warning('unexpected data type')
return []
return ServiceAttribute.list_from_data_elements(attribute_list_sequence.value)
# -----------------------------------------------------------------------------
class Server:
CONTINUATION_STATE = bytes([0x01, 0x43])
def __init__(self, device):
self.device = device
self.service_records = {} # Service records maps, by record handle
self.channel = None
self.current_response = None
def register(self, l2cap_channel_manager):
l2cap_channel_manager.register_server(SDP_PSM, self.on_connection)
def send_response(self, response):
logger.debug(f'{color(">>> Sending SDP Response", "blue")}: {response}')
self.channel.send_pdu(response)
def match_services(self, search_pattern):
# Find the services for which the attributes in the pattern is a subset of the
# service's attribute values (NOTE: the value search recurses into sequences)
matching_services = {}
for handle, service in self.service_records.items():
for uuid in search_pattern.value:
found = False
for attribute in service:
if ServiceAttribute.is_uuid_in_value(uuid.value, attribute.value):
found = True
break
if found:
matching_services[handle] = service
break
return matching_services
def on_connection(self, channel):
self.channel = channel
self.channel.sink = self.on_pdu
def on_pdu(self, pdu):
try:
sdp_pdu = SDP_PDU.from_bytes(pdu)
except Exception as error:
logger.warning(color(f'failed to parse SDP Request PDU: {error}', 'red'))
self.send_response(
SDP_ErrorResponse(
transaction_id=0, error_code=SDP_INVALID_REQUEST_SYNTAX_ERROR
)
)
logger.debug(f'{color("<<< Received SDP Request", "green")}: {sdp_pdu}')
# Find the handler method
handler_name = f'on_{sdp_pdu.name.lower()}'
handler = getattr(self, handler_name, None)
if handler:
try:
handler(sdp_pdu)
except Exception as error:
logger.warning(f'{color("!!! Exception in handler:", "red")} {error}')
self.send_response(
SDP_ErrorResponse(
transaction_id=sdp_pdu.transaction_id,
error_code=SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR,
)
)
else:
logger.error(color('SDP Request not handled???', 'red'))
self.send_response(
SDP_ErrorResponse(
transaction_id=sdp_pdu.transaction_id,
error_code=SDP_INVALID_REQUEST_SYNTAX_ERROR,
)
)
def get_next_response_payload(self, maximum_size):
if len(self.current_response) > maximum_size:
payload = self.current_response[:maximum_size]
continuation_state = Server.CONTINUATION_STATE
self.current_response = self.current_response[maximum_size:]
else:
payload = self.current_response
continuation_state = bytes([0])
self.current_response = None
return (payload, continuation_state)
@staticmethod
def get_service_attributes(service, attribute_ids):
attributes = []
for attribute_id in attribute_ids:
if attribute_id.value_size == 4:
# Attribute ID range
id_range_start = attribute_id.value >> 16
id_range_end = attribute_id.value & 0xFFFF
else:
id_range_start = attribute_id.value
id_range_end = attribute_id.value
attributes += [
attribute
for attribute in service
if attribute.id >= id_range_start and attribute.id <= id_range_end
]
# Return the matching attributes, sorted by attribute id
attributes.sort(key=lambda x: x.id)
attribute_list = DataElement.sequence([])
for attribute in attributes:
attribute_list.value.append(DataElement.unsigned_integer_16(attribute.id))
attribute_list.value.append(attribute.value)
return attribute_list
def on_sdp_service_search_request(self, request):
# Check if this is a continuation
if len(request.continuation_state) > 1:
if not self.current_response:
self.send_response(
SDP_ErrorResponse(
transaction_id=request.transaction_id,
error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
)
)
return
else:
# Cleanup any partial response leftover
self.current_response = None
# Find the matching services
matching_services = self.match_services(request.service_search_pattern)
service_record_handles = list(matching_services.keys())
# Only return up to the maximum requested
service_record_handles_subset = service_record_handles[
: request.maximum_service_record_count
]
# Serialize to a byte array, and remember the total count
logger.debug(f'Service Record Handles: {service_record_handles}')
self.current_response = (
len(service_record_handles),
service_record_handles_subset,
)
# Respond, keeping any unsent handles for later
service_record_handles = self.current_response[1][
: request.maximum_service_record_count
]
self.current_response = (
self.current_response[0],
self.current_response[1][request.maximum_service_record_count :],
)
continuation_state = (
Server.CONTINUATION_STATE if self.current_response[1] else bytes([0])
)
service_record_handle_list = b''.join(
[struct.pack('>I', handle) for handle in service_record_handles]
)
self.send_response(
SDP_ServiceSearchResponse(
transaction_id=request.transaction_id,
total_service_record_count=self.current_response[0],
current_service_record_count=len(service_record_handles),
service_record_handle_list=service_record_handle_list,
continuation_state=continuation_state,
)
)
def on_sdp_service_attribute_request(self, request):
# Check if this is a continuation
if len(request.continuation_state) > 1:
if not self.current_response:
self.send_response(
SDP_ErrorResponse(
transaction_id=request.transaction_id,
error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
)
)
return
else:
# Cleanup any partial response leftover
self.current_response = None
# Check that the service exists
service = self.service_records.get(request.service_record_handle)
if service is None:
self.send_response(
SDP_ErrorResponse(
transaction_id=request.transaction_id,
error_code=SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR,
)
)
return
# Get the attributes for the service
attribute_list = Server.get_service_attributes(
service, request.attribute_id_list.value
)
# Serialize to a byte array
logger.debug(f'Attributes: {attribute_list}')
self.current_response = bytes(attribute_list)
# Respond, keeping any pending chunks for later
attribute_list, continuation_state = self.get_next_response_payload(
request.maximum_attribute_byte_count
)
self.send_response(
SDP_ServiceAttributeResponse(
transaction_id=request.transaction_id,
attribute_list_byte_count=len(attribute_list),
attribute_list=attribute_list,
continuation_state=continuation_state,
)
)
def on_sdp_service_search_attribute_request(self, request):
# Check if this is a continuation
if len(request.continuation_state) > 1:
if not self.current_response:
self.send_response(
SDP_ErrorResponse(
transaction_id=request.transaction_id,
error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
)
)
else:
# Cleanup any partial response leftover
self.current_response = None
# Find the matching services
matching_services = self.match_services(
request.service_search_pattern
).values()
# Filter the required attributes
attribute_lists = DataElement.sequence([])
for service in matching_services:
attribute_list = Server.get_service_attributes(
service, request.attribute_id_list.value
)
if attribute_list.value:
attribute_lists.value.append(attribute_list)
# Serialize to a byte array
logger.debug(f'Search response: {attribute_lists}')
self.current_response = bytes(attribute_lists)
# Respond, keeping any pending chunks for later
attribute_lists, continuation_state = self.get_next_response_payload(
request.maximum_attribute_byte_count
)
self.send_response(
SDP_ServiceSearchAttributeResponse(
transaction_id=request.transaction_id,
attribute_lists_byte_count=len(attribute_lists),
attribute_lists=attribute_lists,
continuation_state=continuation_state,
)
)
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