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zxzxwu merged 1 commit into from
Jan 16, 2026
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GATT: Support Multiple Requests #862

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129 changes: 97 additions & 32 deletions bumble/att.py
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@
import functools
import inspect
import struct
from collections.abc import Awaitable, Callable
from collections.abc import Awaitable, Callable, Sequence
from typing import (
TYPE_CHECKING,
ClassVar,
Expand Down Expand Up @@ -72,34 +72,36 @@ def is_enhanced_bearer(bearer: Bearer) -> TypeIs[EnhancedBearer]:
EATT_PSM = 0x0027

class Opcode(hci.SpecableEnum):
ATT_ERROR_RESPONSE = 0x01
ATT_EXCHANGE_MTU_REQUEST = 0x02
ATT_EXCHANGE_MTU_RESPONSE = 0x03
ATT_FIND_INFORMATION_REQUEST = 0x04
ATT_FIND_INFORMATION_RESPONSE = 0x05
ATT_FIND_BY_TYPE_VALUE_REQUEST = 0x06
ATT_FIND_BY_TYPE_VALUE_RESPONSE = 0x07
ATT_READ_BY_TYPE_REQUEST = 0x08
ATT_READ_BY_TYPE_RESPONSE = 0x09
ATT_READ_REQUEST = 0x0A
ATT_READ_RESPONSE = 0x0B
ATT_READ_BLOB_REQUEST = 0x0C
ATT_READ_BLOB_RESPONSE = 0x0D
ATT_READ_MULTIPLE_REQUEST = 0x0E
ATT_READ_MULTIPLE_RESPONSE = 0x0F
ATT_READ_BY_GROUP_TYPE_REQUEST = 0x10
ATT_READ_BY_GROUP_TYPE_RESPONSE = 0x11
ATT_WRITE_REQUEST = 0x12
ATT_WRITE_RESPONSE = 0x13
ATT_WRITE_COMMAND = 0x52
ATT_SIGNED_WRITE_COMMAND = 0xD2
ATT_PREPARE_WRITE_REQUEST = 0x16
ATT_PREPARE_WRITE_RESPONSE = 0x17
ATT_EXECUTE_WRITE_REQUEST = 0x18
ATT_EXECUTE_WRITE_RESPONSE = 0x19
ATT_HANDLE_VALUE_NOTIFICATION = 0x1B
ATT_HANDLE_VALUE_INDICATION = 0x1D
ATT_HANDLE_VALUE_CONFIRMATION = 0x1E
ATT_ERROR_RESPONSE = 0x01
ATT_EXCHANGE_MTU_REQUEST = 0x02
ATT_EXCHANGE_MTU_RESPONSE = 0x03
ATT_FIND_INFORMATION_REQUEST = 0x04
ATT_FIND_INFORMATION_RESPONSE = 0x05
ATT_FIND_BY_TYPE_VALUE_REQUEST = 0x06
ATT_FIND_BY_TYPE_VALUE_RESPONSE = 0x07
ATT_READ_BY_TYPE_REQUEST = 0x08
ATT_READ_BY_TYPE_RESPONSE = 0x09
ATT_READ_REQUEST = 0x0A
ATT_READ_RESPONSE = 0x0B
ATT_READ_BLOB_REQUEST = 0x0C
ATT_READ_BLOB_RESPONSE = 0x0D
ATT_READ_MULTIPLE_REQUEST = 0x0E
ATT_READ_MULTIPLE_RESPONSE = 0x0F
ATT_READ_BY_GROUP_TYPE_REQUEST = 0x10
ATT_READ_BY_GROUP_TYPE_RESPONSE = 0x11
ATT_READ_MULTIPLE_VARIABLE_REQUEST = 0x20
ATT_READ_MULTIPLE_VARIABLE_RESPONSE = 0x21
ATT_WRITE_REQUEST = 0x12
ATT_WRITE_RESPONSE = 0x13
ATT_WRITE_COMMAND = 0x52
ATT_SIGNED_WRITE_COMMAND = 0xD2
ATT_PREPARE_WRITE_REQUEST = 0x16
ATT_PREPARE_WRITE_RESPONSE = 0x17
ATT_EXECUTE_WRITE_REQUEST = 0x18
ATT_EXECUTE_WRITE_RESPONSE = 0x19
ATT_HANDLE_VALUE_NOTIFICATION = 0x1B
ATT_HANDLE_VALUE_INDICATION = 0x1D
ATT_HANDLE_VALUE_CONFIRMATION = 0x1E

ATT_REQUESTS = [
Opcode.ATT_EXCHANGE_MTU_REQUEST,
Expand All @@ -110,9 +112,10 @@ class Opcode(hci.SpecableEnum):
Opcode.ATT_READ_BLOB_REQUEST,
Opcode.ATT_READ_MULTIPLE_REQUEST,
Opcode.ATT_READ_BY_GROUP_TYPE_REQUEST,
Opcode.ATT_READ_MULTIPLE_VARIABLE_REQUEST,
Opcode.ATT_WRITE_REQUEST,
Opcode.ATT_PREPARE_WRITE_REQUEST,
Opcode.ATT_EXECUTE_WRITE_REQUEST
Opcode.ATT_EXECUTE_WRITE_REQUEST,
]

ATT_RESPONSES = [
Expand All @@ -125,9 +128,10 @@ class Opcode(hci.SpecableEnum):
Opcode.ATT_READ_BLOB_RESPONSE,
Opcode.ATT_READ_MULTIPLE_RESPONSE,
Opcode.ATT_READ_BY_GROUP_TYPE_RESPONSE,
Opcode.ATT_READ_MULTIPLE_VARIABLE_RESPONSE,
Opcode.ATT_WRITE_RESPONSE,
Opcode.ATT_PREPARE_WRITE_RESPONSE,
Opcode.ATT_EXECUTE_WRITE_RESPONSE
Opcode.ATT_EXECUTE_WRITE_RESPONSE,
]

class ErrorCode(hci.SpecableEnum):
Expand Down Expand Up @@ -185,6 +189,18 @@ class ErrorCode(hci.SpecableEnum):
ATT_DEFAULT_MTU = 23

HANDLE_FIELD_SPEC = {'size': 2, 'mapper': lambda x: f'0x{x:04X}'}
_SET_OF_HANDLES_METADATA = hci.metadata({
'parser': lambda data, offset: (
len(data),
[
struct.unpack_from('<H', data, i)[0]
for i in range(offset, len(data), 2)
],
),
'serializer': lambda handles: b''.join(
[struct.pack('<H', handle) for handle in handles]
),
})

# fmt: on
# pylint: enable=line-too-long
Expand Down Expand Up @@ -554,7 +570,7 @@ class ATT_Read_Multiple_Request(ATT_PDU):
See Bluetooth spec @ Vol 3, Part F - 3.4.4.7 Read Multiple Request
'''

set_of_handles: bytes = dataclasses.field(metadata=hci.metadata("*"))
set_of_handles: Sequence[int] = dataclasses.field(metadata=_SET_OF_HANDLES_METADATA)


# -----------------------------------------------------------------------------
Expand Down Expand Up @@ -635,6 +651,55 @@ def __str__(self):
return result


# -----------------------------------------------------------------------------
@ATT_PDU.subclass
@dataclasses.dataclass
class ATT_Read_Multiple_Variable_Request(ATT_PDU):
'''
See Bluetooth spec @ Vol 3, Part F - 3.4.4.11 Read Multiple Variable Request
'''

set_of_handles: Sequence[int] = dataclasses.field(metadata=_SET_OF_HANDLES_METADATA)


# -----------------------------------------------------------------------------
@ATT_PDU.subclass
@dataclasses.dataclass
class ATT_Read_Multiple_Variable_Response(ATT_PDU):
'''
See Bluetooth spec @ Vol 3, Part F - 3.4.4.12 Read Multiple Variable Response
'''

@classmethod
def _parse_length_value_tuples(
cls, data: bytes, offset: int
) -> tuple[int, list[tuple[int, bytes]]]:
length_value_tuple_list: list[tuple[int, bytes]] = []
while offset < len(data):
length = struct.unpack_from('<H', data, offset)[0]
length_value_tuple_list.append(
(length, data[offset + 2 : offset + 2 + length])
)
offset += 2 + length
return (len(data), length_value_tuple_list)

length_value_tuple_list: Sequence[tuple[int, bytes]] = dataclasses.field(
metadata=hci.metadata(
{
'parser': lambda data, offset: ATT_Read_Multiple_Variable_Response._parse_length_value_tuples(
data, offset
),
'serializer': lambda length_value_tuple_list: b''.join(
[
struct.pack('<H', length) + value
for length, value in length_value_tuple_list
]
),
}
)
)


# -----------------------------------------------------------------------------
@ATT_PDU.subclass
@dataclasses.dataclass
Expand Down
88 changes: 88 additions & 0 deletions bumble/gatt_server.py
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -977,6 +977,94 @@ async def on_att_read_by_group_type_request(

self.send_response(bearer, response)

@utils.AsyncRunner.run_in_task()
async def on_att_read_multiple_request(
self, bearer: att.Bearer, request: att.ATT_Read_Multiple_Request
):
'''
See Bluetooth spec Vol 3, Part F - 3.4.4.7 Read Multiple Request.
'''
response: att.ATT_PDU

pdu_space_available = bearer.att_mtu - 1
values: list[bytes] = []

for handle in request.set_of_handles:
if not (attribute := self.get_attribute(handle)):
response = att.ATT_Error_Response(
request_opcode_in_error=request.op_code,
attribute_handle_in_error=handle,
error_code=att.ATT_ATTRIBUTE_NOT_FOUND_ERROR,
)
self.send_response(bearer, response)
return
# No need to catch permission errors here, since these attributes
# must all be world-readable
attribute_value = await attribute.read_value(bearer)
# Check the attribute value size
max_attribute_size = min(bearer.att_mtu - 1, 251)
if len(attribute_value) > max_attribute_size:
# We need to truncate
attribute_value = attribute_value[:max_attribute_size]

# Check if there is enough space
entry_size = len(attribute_value)
if pdu_space_available < entry_size:
break

# Add the attribute to the list
values.append(attribute_value)
pdu_space_available -= entry_size

response = att.ATT_Read_Multiple_Response(set_of_values=b''.join(values))
self.send_response(bearer, response)

@utils.AsyncRunner.run_in_task()
async def on_att_read_multiple_variable_request(
self, bearer: att.Bearer, request: att.ATT_Read_Multiple_Variable_Request
):
'''
See Bluetooth spec Vol 3, Part F - 3.4.4.11 Read Multiple Variable Request.
'''
response: att.ATT_PDU

pdu_space_available = bearer.att_mtu - 1
length_value_tuple_list: list[tuple[int, bytes]] = []

for handle in request.set_of_handles:
if not (attribute := self.get_attribute(handle)):
response = att.ATT_Error_Response(
request_opcode_in_error=request.op_code,
attribute_handle_in_error=handle,
error_code=att.ATT_ATTRIBUTE_NOT_FOUND_ERROR,
)
self.send_response(bearer, response)
return
# No need to catch permission errors here, since these attributes
# must all be world-readable
attribute_value = await attribute.read_value(bearer)
length = len(attribute_value)
# Check the attribute value size
max_attribute_size = min(bearer.att_mtu - 3, 251)
if len(attribute_value) > max_attribute_size:
# We need to truncate
attribute_value = attribute_value[:max_attribute_size]

# Check if there is enough space
entry_size = 2 + len(attribute_value)

# Add the attribute to the list
length_value_tuple_list.append((length, attribute_value))
pdu_space_available -= entry_size

if pdu_space_available <= 0:
break

response = att.ATT_Read_Multiple_Variable_Response(
length_value_tuple_list=length_value_tuple_list
)
self.send_response(bearer, response)

@utils.AsyncRunner.run_in_task()
async def on_att_write_request(
self, bearer: att.Bearer, request: att.ATT_Write_Request
Expand Down
100 changes: 99 additions & 1 deletion tests/gatt_test.py
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@
import pytest
from typing_extensions import Self

from bumble import gatt_client, l2cap
from bumble import att, gatt_client, l2cap
from bumble.att import (
ATT_ATTRIBUTE_NOT_FOUND_ERROR,
ATT_PDU,
Expand Down Expand Up @@ -1638,6 +1638,104 @@ async def test_eatt_connection_failure():
await gatt_client.Client.connect_eatt(devices.connections[0])


# -----------------------------------------------------------------------------
@pytest.mark.asyncio
async def test_read_multiple() -> None:
devices = await TwoDevices.create_with_connection()

characteristic1 = Characteristic(
'0001', Characteristic.Properties.READ, Characteristic.READABLE, b'1234'
)

characteristic2 = Characteristic(
'0002',
Characteristic.Properties.READ,
Characteristic.READABLE,
b'5678',
)

service = Service('0000', [characteristic1, characteristic2])
devices[1].add_service(service)

client = devices.connections[0].gatt_client
server = devices[1].gatt_server

await client.discover_services()
characteristics = await client.discover_characteristics(
[characteristic1.uuid, characteristic2.uuid], None
)
response = await client.send_request(
att.ATT_Read_Multiple_Request(
set_of_handles=[c.handle for c in characteristics]
)
)
assert isinstance(response, att.ATT_Read_Multiple_Response)
assert response.set_of_values == b'12345678'

response = await client.send_request(
att.ATT_Read_Multiple_Request(
set_of_handles=[
next(
handle
for handle in range(0x0001, 0xFFFF)
if not server.get_attribute(handle)
)
]
)
)
assert isinstance(response, att.ATT_Error_Response)
assert response.error_code == att.ATT_ATTRIBUTE_NOT_FOUND_ERROR


# -----------------------------------------------------------------------------
@pytest.mark.asyncio
async def test_read_multiple_variable() -> None:
devices = await TwoDevices.create_with_connection()

characteristic1 = Characteristic(
'0001', Characteristic.Properties.READ, Characteristic.READABLE, b'1234'
)

characteristic2 = Characteristic(
'0002',
Characteristic.Properties.READ,
Characteristic.READABLE,
b'99',
)

service = Service('0000', [characteristic1, characteristic2])
devices[1].add_service(service)

client = devices.connections[0].gatt_client
server = devices[1].gatt_server

await client.discover_services()
characteristics = await client.discover_characteristics(
[characteristic1.uuid, characteristic2.uuid], None
)
response = await client.send_request(
att.ATT_Read_Multiple_Variable_Request(
set_of_handles=[c.handle for c in characteristics]
)
)
assert isinstance(response, att.ATT_Read_Multiple_Variable_Response)
assert response.length_value_tuple_list == [(4, b'1234'), (2, b'99')]

response = await client.send_request(
att.ATT_Read_Multiple_Variable_Request(
set_of_handles=[
next(
handle
for handle in range(0x0001, 0xFFFF)
if not server.get_attribute(handle)
)
]
)
)
assert isinstance(response, att.ATT_Error_Response)
assert response.error_code == att.ATT_ATTRIBUTE_NOT_FOUND_ERROR


# -----------------------------------------------------------------------------
if __name__ == '__main__':
logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
Expand Down
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