def write(self, value, withResponse=False):
"""Blocking write of the descriptor.
Args:
value : a bytearray of length at most send MTU - 3
Raises:
ClientError on failure
"""
assert isinstance(value, bytearray)
op = att.OP_WRITE_REQ if withResponse else att.OP_WRITE_CMD
req = bytearray([op])
req += _handle_to_bytearray(self._handleNo)
req += value
if not withResponse:
self.client._socket._send(req)
return
resp = self.client._new_transaction(req)
if resp is None:
raise ClientError("no response")
elif resp[0] == att.OP_WRITE_RESP:
return resp[1:]
elif resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN:
raise ClientError("write failed - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
def read(self):
"""Blocking read of the descriptor.
Returns:
A bytearray
Raises:
ClientError on failure
"""
if self._cachable and self._cached is not None:
return self._cached
req = bytearray([att.OP_READ_REQ])
req += _handle_to_bytearray(self._handleNo)
resp = self.client._new_transaction(req)
if resp is None:
raise ClientError("no response")
elif resp[0] == att.OP_READ_RESP:
ret = resp[1:]
if self._cachable:
self._cached = ret
return ret
elif resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN:
raise ClientError("read failed - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
def write(self, value, withResponse=True):
"""Blocking write of the characteristic.
Args:
value : a bytearray of length at most send MTU - 3
withResponse : whether the write should be a request or command
Raises:
ClientError on failure
"""
assert isinstance(value, bytearray)
if "w" not in self.permissions:
raise ClientError("write not permitted")
op = att.OP_WRITE_REQ if withResponse else att.OP_WRITE_CMD
req = bytearray([op])
req += _handle_to_bytearray(self._valHandleNo)
req += value
if not withResponse:
self.client._socket._send(req)
return
resp = self.client._new_transaction(req)
if resp is None:
raise ClientError("no response")
elif resp[0] == att.OP_WRITE_RESP:
return resp[1:]
elif resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN:
raise ClientError("write failed - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
def __discover_services_by_uuid(self, uuid, startHandle, endHandle):
primSvcUuid = UUID(gatt.PRIM_SVC_UUID)
services = []
newServices = []
serviceHandles = {}
currHandle = startHandle
while True:
req = att_pdu.new_find_by_type_value_req(currHandle, endHandle,
primSvcUuid, uuid.raw[::-1])
resp = self._new_transaction(req)
if not resp:
raise ClientError("transaction failed")
if resp[0] == att.OP_FIND_BY_TYPE_REQ:
idx = 2
endGroup = currHandle # not needed
while idx < len(resp) and idx + 4 <= len(resp):
handleNo = att_pdu.unpack_handle(resp, idx)
endGroup = att_pdu.unpack_handle(resp, idx + 2)
if handleNo in self._serviceHandles:
service = self._serviceHandles[handleNo]
else:
service = _ClientService(self, uuid, handleNo, endGroup)
serviceHandles[handleNo] = service
newServices.append(service)
services.append(service)
idx += 4
currHandle = endGroup + 1
if currHandle >= endHandle:
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_FIND_BY_TYPE_REQ
and resp[4] == att.ECODE_ATTR_NOT_FOUND):
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_FIND_BY_TYPE_REQ):
raise ClientError("error - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
self.services.extend(newServices)
self.services.sort(key=lambda x: x._handleNo)
self._serviceHandles.update(serviceHandles)
return services
def __discover_services(self, startHandle, endHandle):
primSvcUuid = UUID(gatt.PRIM_SVC_UUID)
services = []
serviceHandles = {}
currHandle = startHandle
while True:
req = att_pdu.new_read_by_group_req(currHandle, endHandle,
primSvcUuid)
resp = self._new_transaction(req)
if not resp:
raise ClientError("transaction failed")
if resp[0] == att.OP_READ_BY_GROUP_RESP:
attDataLen = resp[1]
idx = 2
endGroup = currHandle # not needed
while idx < len(resp) and idx + attDataLen <= len(resp):
handleNo = att_pdu.unpack_handle(resp, idx)
endGroup = att_pdu.unpack_handle(resp, idx + 2)
uuid = UUID(resp[idx+4:idx+attDataLen], reverse=True)
service = _ClientService(self, uuid, handleNo, endGroup)
services.append(service)
serviceHandles[handleNo] = service
idx += attDataLen
currHandle = endGroup + 1
if currHandle >= endHandle:
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_READ_BY_GROUP_REQ
and resp[4] == att.ECODE_ATTR_NOT_FOUND):
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_READ_BY_GROUP_REQ):
raise ClientError("error - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
return services, serviceHandles
def read(self):
"""Blocking read of the characteristic.
Returns:
A bytearray
Raises:
ClientError on failure
"""
if "r" not in self.permissions:
raise ClientError("read not permitted")
req = bytearray([att.OP_READ_REQ])
req += _handle_to_bytearray(self._valHandleNo)
resp = self.client._new_transaction(req)
if resp is None:
raise ClientError("no response")
elif resp[0] == att.OP_READ_RESP:
return resp[1:]
elif resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN:
raise ClientError("read failed - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
def __discover_all_characteristics(self):
startHandle = self._handleNo + 1
endHandle = self._endGroup
if startHandle > endHandle:
return [], {}
characUuid = UUID(gatt.CHARAC_UUID)
characs = []
characHandles = {}
currHandle = startHandle
while True:
req = att_pdu.new_read_by_type_req(currHandle, endHandle,
characUuid)
resp = self.client._new_transaction(req)
if not resp:
raise ClientError("transaction failed")
if resp[0] == att.OP_READ_BY_TYPE_RESP:
attDataLen = resp[1]
idx = 2
maxHandleNo = currHandle # not needed
while idx < len(resp) and idx + attDataLen <= len(resp):
handleNo = att_pdu.unpack_handle(resp, idx)
properties = resp[idx+2]
valHandleNo = att_pdu.unpack_handle(resp, idx + 3)
uuid = UUID(resp[idx+5:idx+attDataLen], reverse=True)
charac = _ClientCharacteristic(self.client, self, uuid,
handleNo, properties, valHandleNo)
characs.append(charac)
characHandles[handleNo] = characs
idx += attDataLen
maxHandleNo = valHandleNo
currHandle = maxHandleNo + 1
if currHandle >= endHandle:
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_READ_BY_TYPE_REQ
and resp[4] == att.ECODE_ATTR_NOT_FOUND):
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_READ_BY_TYPE_REQ
and resp[4] == att.ECODE_READ_NOT_PERM):
currHandle = currHandle + 1
if currHandle >= endHandle:
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_READ_BY_TYPE_REQ):
raise ClientError("error - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
for i, charac in enumerate(characs):
if i + 1 < len(characs):
charac._set_end_group(characs[i+1]._handleNo-1)
else:
charac._set_end_group(self._endGroup)
return characs, characHandles
def discoverDescriptors(self):
"""Return a list of descriptors"""
assert self._endGroup is not None
startHandle = self._handleNo + 1
endHandle = self._endGroup
if startHandle > endHandle:
return []
descriptors = []
cccdUuid = UUID(gatt.CLIENT_CHARAC_CFG_UUID)
cccd = None
userDescUuid = UUID(gatt.CHARAC_USER_DESC_UUID)
userDesc = None
currHandle = startHandle
while True:
req = att_pdu.new_find_info_req(currHandle, endHandle)
resp = self.client._new_transaction(req)
if not resp:
raise ClientError("transaction failed")
if resp[0] == att.OP_FIND_INFO_RESP:
attDataLen = 4 if resp[1] == att.FIND_INFO_RESP_FMT_16BIT \
else 18
idx = 2
handleNo = currHandle # not needed
while idx < len(resp) and idx + attDataLen <= len(resp):
handleNo = att_pdu.unpack_handle(resp, idx)
uuid = UUID(resp[idx+2:idx+attDataLen], reverse=True)
if handleNo == self._valHandleNo:
idx += attDataLen
continue
if uuid == userDescUuid:
descriptor = _ClientDescriptor(self.client, self, uuid,
handleNo, cacheable=True)
userDesc = descriptor
else:
descriptor = _ClientDescriptor(self.client, self, uuid,
handleNo)
if uuid == cccdUuid:
# hide the cccd from users
cccd = descriptor
else:
descriptors.append(descriptor)
idx += attDataLen
currHandle = handleNo + 1
if currHandle >= endHandle:
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_FIND_INFO_REQ
and resp[4] == att.ECODE_ATTR_NOT_FOUND):
break
elif (resp[0] == att.OP_ERROR and len(resp) == att_pdu.ERROR_PDU_LEN
and resp[1] == att.OP_FIND_INFO_REQ):
raise ClientError("error - %s" % att.ecodeLookup(resp[4]))
else:
raise ClientError("unexpected - %s" % att.opcodeLookup(resp[0]))
self.descriptors = descriptors
self._cccd = cccd
self._user_desc = userDesc
return descriptors