# Copyright (c) 2020 Jeff Irion and contributors
#
# This file is part of the aio-adb-shell package. It incorporates work
# covered by the following license notice:
#
#
# Copyright 2014 Google Inc. All rights reserved.
#
# 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
#
# http://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,
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"""Functions and an :class:`AdbMessage` class for packing and unpacking ADB messages.
.. rubric:: Contents
* :class:`AdbMessage`
* :attr:`AdbMessage.checksum`
* :meth:`AdbMessage.pack`
* :func:`checksum`
* :func:`unpack`
"""
import struct
from . import constants
[docs]def checksum(data):
"""Calculate the checksum of the provided data.
Parameters
----------
data : bytearray, bytes, str
The data
Returns
-------
int
The checksum
"""
# The checksum is just a sum of all the bytes. I swear.
if isinstance(data, bytearray):
total = sum(data)
elif isinstance(data, bytes):
if data and isinstance(data[0], bytes):
# Python 2 bytes (str) index as single-character strings.
total = sum((ord(d) for d in data)) # pragma: no cover
else:
# Python 3 bytes index as numbers (and PY2 empty strings sum() to 0)
total = sum(data)
else:
# Unicode strings (should never see?)
total = sum((ord(d) for d in data))
return total & 0xFFFFFFFF
[docs]def unpack(message):
"""Unpack a received ADB message.
Parameters
----------
message : bytes
The received message
Returns
-------
cmd : int
The ADB command
arg0 : int
TODO
arg1 : int
TODO
data_length : int
The length of the data sent by the device (used by :meth:`adb_shell.adb_device._read`)
data_checksum : int
The checksum of the data sent by the device
Raises
------
ValueError
Unable to unpack the ADB command.
"""
try:
cmd, arg0, arg1, data_length, data_checksum, _ = struct.unpack(constants.MESSAGE_FORMAT, message)
except struct.error as e:
raise ValueError('Unable to unpack ADB command. (length={})'.format(len(message)), constants.MESSAGE_FORMAT, message, e)
return cmd, arg0, arg1, data_length, data_checksum
[docs]class AdbMessage(object):
"""A helper class for packing ADB messages.
Parameters
----------
command : bytes
A command; examples used in this package include :const:`adb_shell.constants.AUTH`, :const:`adb_shell.constants.CNXN`, :const:`adb_shell.constants.CLSE`, :const:`adb_shell.constants.OPEN`, and :const:`adb_shell.constants.OKAY`
arg0 : int
Usually the local ID, but :meth:`~adb_shell.adb_device.AdbDevice.connect` provides :const:`adb_shell.constants.VERSION`, :const:`adb_shell.constants.AUTH_SIGNATURE`, and :const:`adb_shell.constants.AUTH_RSAPUBLICKEY`
arg1 : int
Usually the remote ID, but :meth:`~adb_shell.adb_device.AdbDevice.connect` provides :const:`adb_shell.constants.MAX_ADB_DATA`
data : bytes
The data that will be sent
Attributes
----------
arg0 : int
Usually the local ID, but :meth:`~adb_shell.adb_device.AdbDevice.connect` provides :const:`adb_shell.constants.VERSION`, :const:`adb_shell.constants.AUTH_SIGNATURE`, and :const:`adb_shell.constants.AUTH_RSAPUBLICKEY`
arg1 : int
Usually the remote ID, but :meth:`~adb_shell.adb_device.AdbDevice.connect` provides :const:`adb_shell.constants.MAX_ADB_DATA`
command : int
The input parameter ``command`` converted to an integer via :const:`adb_shell.constants.ID_TO_WIRE`
data : bytes
The data that will be sent
magic : int
``self.command`` with its bits flipped; in other words, ``self.command + self.magic == 2**32 - 1``
"""
def __init__(self, command, arg0, arg1, data=b''):
self.command = constants.ID_TO_WIRE[command]
self.magic = self.command ^ 0xFFFFFFFF
self.arg0 = arg0
self.arg1 = arg1
self.data = data
[docs] def pack(self):
"""Returns this message in an over-the-wire format.
Returns
-------
bytes
The message packed into the format required by ADB
"""
return struct.pack(constants.MESSAGE_FORMAT, self.command, self.arg0, self.arg1, len(self.data), self.checksum, self.magic)
@property
def checksum(self):
"""Return ``checksum(self.data)``
Returns
-------
int
The checksum of ``self.data``
"""
return checksum(self.data)