commands/FBCopyCommands.py

#!/usr/bin/python

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.

from __future__ import print_function

import errno
import os
import time

import fbchisellldbbase as fb
import fbchisellldbobjecthelpers as objectHelpers
import lldb


def lldbcommands():
    return [FBCopyCommand()]


def _copyFromURL(url, preferredFilename, noOpen):
    data = fb.evaluateObjectExpression(
        "(id)[NSData dataWithContentsOfURL:(id){}]".format(url)
    )
    defaultFilename = fb.describeObject(
        "(id)[[{} pathComponents] lastObject]".format(url)
    )
    _copyFromData(data, defaultFilename, preferredFilename, noOpen)


def _copyFromData(data, defaultFilename, preferredFilename, noOpen):
    directory = "/tmp/chisel_copy/"

    path = directory + (preferredFilename or defaultFilename)

    try:
        os.makedirs(directory)
    except OSError as e:
        if e.errno == errno.EEXIST and os.path.isdir(directory):
            pass
        else:
            raise

    startAddress = fb.evaluateExpression("(void *)[(id)" + data + " bytes]")
    length = fb.evaluateExpression("(NSUInteger)[(id)" + data + " length]")

    address = int(startAddress, 16)
    length = int(length)

    if not (address or length):
        print("Could not get data.")
        return

    process = lldb.debugger.GetSelectedTarget().GetProcess()
    error = lldb.SBError()
    mem = process.ReadMemory(address, length, error)

    if error is not None and str(error) != "success":
        print(error)
    else:
        with open(path, "wb") as file:
            file.write(mem)
            file.close()
        print(path)
        if not noOpen:
            os.system("open " + path)


def _copy(target, preferredFilename, noOpen):
    target = "(" + target + ")"

    if objectHelpers.isKindOfClass(target, "NSURL"):
        _copyFromURL(target, preferredFilename, noOpen)
    elif objectHelpers.isKindOfClass(target, "NSData"):
        _copyFromData(
            target,
            time.strftime("%Y-%m-%d-%H-%M-%S", time.gmtime()) + ".data",
            preferredFilename,
            noOpen,
        )
    else:
        print(
            "{} isn't supported. You can copy an NSURL or NSData.".format(
                objectHelpers.className(target)
            )
        )


class FBCopyCommand(fb.FBCommand):
    def name(self):
        return "copy"

    def description(self):
        return "Copy data to your Mac."

    def options(self):
        return [
            fb.FBCommandArgument(
                short="-f",
                long="--filename",
                arg="filename",
                help="The output filename.",
            ),
            fb.FBCommandArgument(
                short="-n",
                long="--no-open",
                arg="noOpen",
                boolean=True,
                default=False,
                help="Do not open the file.",
            ),
        ]

    def args(self):
        return [
            fb.FBCommandArgument(arg="target", type="(id)", help="The object to copy.")
        ]

    def run(self, arguments, options):
        _copy(arguments[0], options.filename, options.noOpen)