client/cros/faft/rpc_functions.py

# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Code to provide functions for FAFT tests.

These can be exposed via a xmlrpci server running on the DUT.
"""

import functools, os, shutil, tempfile

import common
from autotest_lib.client.cros.faft.utils import (cgpt_handler,
                                                 chromeos_interface,
                                                 firmware_check_keys,
                                                 firmware_updater,
                                                 flashrom_handler,
                                                 kernel_handler,
                                                 rootfs_handler,
                                                 saft_flashrom_util,
                                                 tpm_handler,
                                                )


def allow_multiple_section_input(image_operator):
    """Decorate a method to support multiple sections.

    @param image_operator: Method accepting one section as its argument.
    """
    @functools.wraps(image_operator)
    def wrapper(self, section):
        """Wrapper method to support multiple sections.

        @param section: A list of sections of just a section.
        """
        if type(section) in (tuple, list):
            for sec in section:
                image_operator(self, sec)
        else:
            image_operator(self, section)
    return wrapper


class LazyFlashromHandlerProxy:
    """Proxy of FlashromHandler for lazy initialization."""
    _loaded = False
    _obj = None

    def __init__(self, *args, **kargs):
        self._args = args
        self._kargs = kargs

    def _load(self):
        self._obj = flashrom_handler.FlashromHandler()
        self._obj.init(*self._args, **self._kargs)
        self._obj.new_image()
        self._loaded = True

    def __getattr__(self, name):
        if not self._loaded:
            self._load()
        return getattr(self._obj, name)

    def reload(self):
        """Reload the FlashromHandler class."""
        self._loaded = False


class RPCFunctions(object):
    """A class which aggregates some useful functions for firmware testing.

    This class can be exposed via a XMLRPC server such that its functions can
    be accessed remotely. Method naming should fit the naming rule
    '_[categories]_[method_name]' where categories contains system, ec, bios,
    kernel, cgpt, tpm, updater, etc. Methods should be called by
    'FAFTClient.[categories].[method_name]', because _dispatch will rename
    this name to '_[categories]_[method_name]'.

    Attributes:
        _chromeos_interface: An object to encapsulate OS services functions.
        _bios_handler: An object to automate BIOS flashrom testing.
        _ec_handler: An object to automate EC flashrom testing.
        _ec_image: An object to automate EC image for autest.
        _kernel_handler: An object to provide kernel related actions.
        _log_file: Path of the log file.
        _tpm_handler: An object to control TPM device.
        _updater: An object to update firmware.
        _temp_path: Path of a temp directory.
        _keys_path: Path of a directory, keys/, in temp directory.
        _work_path: Path of a directory, work/, in temp directory.
    """
    def __init__(self):
        """Initialize the data attributes of this class."""
        # TODO(waihong): Move the explicit object.init() methods to the
        # objects' constructors (ChromeOSInterface, FlashromHandler,
        # KernelHandler, and TpmHandler).
        self._chromeos_interface = chromeos_interface.ChromeOSInterface(False)
        # We keep the state of FAFT test in a permanent directory over reboots.
        state_dir = '/var/tmp/faft'
        self._log_file = os.path.join(state_dir, 'faft_client.log')
        self._chromeos_interface.init(state_dir, log_file=self._log_file)
        os.chdir(state_dir)

        self._bios_handler = LazyFlashromHandlerProxy(
                                saft_flashrom_util,
                                self._chromeos_interface,
                                None,
                                '/usr/share/vboot/devkeys',
                                'bios')

        self._ec_handler = None
        if not os.system("mosys ec info"):
            self._ec_handler = LazyFlashromHandlerProxy(
                                  saft_flashrom_util,
                                  self._chromeos_interface,
                                  'ec_root_key.vpubk',
                                  '/usr/share/vboot/devkeys',
                                  'ec')

        self._ec_image = None

        self._kernel_handler = kernel_handler.KernelHandler()
        # TODO(waihong): The dev_key_path is a new argument. We do that in
        # order not to break the old image and still be able to run.
        try:
            self._kernel_handler.init(self._chromeos_interface,
                                      dev_key_path='/usr/share/vboot/devkeys',
                                      internal_disk=True)
        except TypeError:
            # Copy the key to the current working directory.
            shutil.copy('/usr/share/vboot/devkeys/kernel_data_key.vbprivk', '.')
            self._kernel_handler.init(self._chromeos_interface,
                                      internal_disk=True)

        self._tpm_handler = tpm_handler.TpmHandler()
        self._tpm_handler.init(self._chromeos_interface)

        self._cgpt_handler = cgpt_handler.CgptHandler(self._chromeos_interface)

        self._rootfs_handler = rootfs_handler.RootfsHandler()
        self._rootfs_handler.init(self._chromeos_interface)

        self._updater = firmware_updater.FirmwareUpdater(self._chromeos_interface)
        self._check_keys = firmware_check_keys.firmwareCheckKeys()

        # Initialize temporary directory path
        self._temp_path = '/var/tmp/faft/autest'
        self._keys_path = os.path.join(self._temp_path, 'keys')
        self._work_path = os.path.join(self._temp_path, 'work')

    def _dispatch(self, method, params):
        """This _dispatch method handles string conversion especially.

        Since we turn off allow_dotted_names option. So any string conversion,
        like str(FAFTClient.method), i.e. FAFTClient.method.__str__, failed
        via XML RPC call.
        """
        is_str = method.endswith('.__str__')
        if is_str:
            method = method.rsplit('.', 1)[0]

        categories = ('system', 'bios', 'ec', 'kernel',
                      'tpm', 'cgpt', 'updater', 'rootfs')
        try:
            if method.split('.', 1)[0] in categories:
                func = getattr(self, '_%s_%s' % (method.split('.', 1)[0],
                                                 method.split('.', 1)[1]))
            else:
                func = getattr(self, method)
        except AttributeError:
            raise Exception('method "%s" is not supported' % method)

        if is_str:
            return str(func)
        else:
            self._chromeos_interface.log('Dispatching method %s with args %s' %
                    (str(func), str(params)))
            return func(*params)

    def _system_is_available(self):
        """Function for polling the RPC server availability.

        @return: Always True.
        """
        return True

    def _system_dump_log(self, remove_log=False):
        """Dump the log file.

        @param remove_log: Remove the log file after dump.
        @return: String of the log file content.
        """
        log = open(self._log_file).read()
        if remove_log:
            os.remove(self._log_file)
        return log

    def _system_run_shell_command(self, command):
        """Run shell command.

        @param command: A shell command to be run.
        """
        self._chromeos_interface.run_shell_command(command)

    def _system_run_shell_command_get_output(self, command):
        """Run shell command and get its console output.

        @param command: A shell command to be run.
        @return: A list of strings stripped of the newline characters.
        """
        return self._chromeos_interface.run_shell_command_get_output(command)

    def _system_software_reboot(self):
        """Request software reboot."""
        self._chromeos_interface.run_shell_command('reboot')

    def _system_get_platform_name(self):
        """Get the platform name of the current system.

        @return: A string of the platform name.
        """
        # 'mosys platform name' sometimes fails. Let's get the verbose output.
        lines = self._chromeos_interface.run_shell_command_get_output(
                '(mosys -vvv platform name 2>&1) || echo Failed')
        if lines[-1].strip() == 'Failed':
            raise Exception('Failed getting platform name: ' + '\n'.join(lines))
        return lines[-1]

    def _system_get_crossystem_value(self, key):
        """Get crossystem value of the requested key.

        @param key: A crossystem key.
        @return: A string of the requested crossystem value.
        """
        return self._chromeos_interface.run_shell_command_get_output(
                'crossystem %s' % key)[0]

    def _system_get_root_dev(self):
        """Get the name of root device without partition number.

        @return: A string of the root device without partition number.
        """
        return self._chromeos_interface.get_root_dev()

    def _system_get_root_part(self):
        """Get the name of root device with partition number.

        @return: A string of the root device with partition number.
        """
        return self._chromeos_interface.get_root_part()

    def _system_set_try_fw_b(self, count=1):
        """Set 'Try Frimware B' flag in crossystem.

        @param count: # times to try booting into FW B
        """
        self._chromeos_interface.cs.fwb_tries = count

    def _system_set_fw_try_next(self, next, count=0):
        """Set fw_try_next to A or B

        @param next: Next FW to reboot to (A or B)
        @param count: # of times to try booting into FW <next>
        """
        self._chromeos_interface.cs.fw_try_next = next
        if count:
            self._chromeos_interface.cs.fw_try_count = count

    def _system_get_fw_vboot2(self):
        """Get fw_vboot2"""
        try:
            return self._chromeos_interface.cs.fw_vboot2 == '1'
        except chromeos_interface.ChromeOSInterfaceError:
            return False

    def _system_request_recovery_boot(self):
        """Request running in recovery mode on the restart."""
        self._chromeos_interface.cs.request_recovery()

    def _system_get_dev_boot_usb(self):
        """Get dev_boot_usb value which controls developer mode boot from USB.

        @return: True if enable, False if disable.
        """
        return self._chromeos_interface.cs.dev_boot_usb == '1'

    def _system_set_dev_boot_usb(self, value):
        """Set dev_boot_usb value which controls developer mode boot from USB.

        @param value: True to enable, False to disable.
        """
        self._chromeos_interface.cs.dev_boot_usb = 1 if value else 0

    def _system_is_removable_device_boot(self):
        """Check the current boot device is removable.

        @return: True: if a removable device boots.
                 False: if a non-removable device boots.
        """
        root_part = self._chromeos_interface.get_root_part()
        return self._chromeos_interface.is_removable_device(root_part)

    def _system_create_temp_dir(self, prefix='backup_'):
        """Create a temporary directory and return the path."""
        return tempfile.mkdtemp(prefix=prefix)

    def _bios_reload(self):
        """Reload the firmware image that may be changed."""
        self._bios_handler.reload()

    def _bios_get_gbb_flags(self):
        """Get the GBB flags.

        @return: An integer of the GBB flags.
        """
        return self._bios_handler.get_gbb_flags()

    def _bios_get_preamble_flags(self, section):
        """Get the preamble flags of a firmware section.

        @param section: A firmware section, either 'a' or 'b'.
        @return: An integer of the preamble flags.
        """
        return self._bios_handler.get_section_flags(section)

    def _bios_set_preamble_flags(self, section, flags):
        """Set the preamble flags of a firmware section.

        @param section: A firmware section, either 'a' or 'b'.
        @param flags: An integer of preamble flags.
        """
        version = self._bios_get_version(section)
        self._bios_handler.set_section_version(section, version, flags,
                                               write_through=True)

    def _bios_get_body_sha(self, section):
        """Get SHA1 hash of BIOS RW firmware section.

        @param section: A firmware section, either 'a' or 'b'.
        @param flags: An integer of preamble flags.
        """
        return self._bios_handler.get_section_sha(section)

    def _bios_get_sig_sha(self, section):
        """Get SHA1 hash of firmware vblock in section."""
        return self._bios_handler.get_section_sig_sha(section)

    @allow_multiple_section_input
    def _bios_corrupt_sig(self, section):
        """Corrupt the requested firmware section signature.

        @param section: A firmware section, either 'a' or 'b'.
        """
        self._bios_handler.corrupt_firmware(section)

    @allow_multiple_section_input
    def _bios_restore_sig(self, section):
        """Restore the previously corrupted firmware section signature.

        @param section: A firmware section, either 'a' or 'b'.
        """
        self._bios_handler.restore_firmware(section)

    @allow_multiple_section_input
    def _bios_corrupt_body(self, section):
        """Corrupt the requested firmware section body.

        @param section: A firmware section, either 'a' or 'b'.
        """
        self._bios_handler.corrupt_firmware_body(section)

    @allow_multiple_section_input
    def _bios_restore_body(self, section):
        """Restore the previously corrupted firmware section body.

        @param section: A firmware section, either 'a' or 'b'.
        """
        self._bios_handler.restore_firmware_body(section)

    def __bios_modify_version(self, section, delta):
        """Modify firmware version for the requested section, by adding delta.

        The passed in delta, a positive or a negative number, is added to the
        original firmware version.
        """
        original_version = self._bios_get_version(section)
        new_version = original_version + delta
        flags = self._bios_handler.get_section_flags(section)
        self._chromeos_interface.log(
                'Setting firmware section %s version from %d to %d' % (
                section, original_version, new_version))
        self._bios_handler.set_section_version(section, new_version, flags,
                                               write_through=True)

    @allow_multiple_section_input
    def _bios_move_version_backward(self, section):
        """Decrement firmware version for the requested section."""
        self.__bios_modify_version(section, -1)

    @allow_multiple_section_input
    def _bios_move_version_forward(self, section):
        """Increase firmware version for the requested section."""
        self.__bios_modify_version(section, 1)

    def _bios_get_version(self, section):
        """Retrieve firmware version of a section."""
        return self._bios_handler.get_section_version(section)

    def _bios_get_datakey_version(self, section):
        """Return firmware data key version."""
        return self._bios_handler.get_section_datakey_version(section)

    def _bios_get_kernel_subkey_version(self, section):
        """Return kernel subkey version."""
        return self._bios_handler.get_section_kernel_subkey_version(section)

    def _bios_setup_EC_image(self, ec_path):
        """Setup the new EC image for later update.

        @param ec_path: The path of the EC image to be updated.
        """
        self._ec_image = flashrom_handler.FlashromHandler()
        self._ec_image.init(saft_flashrom_util,
                            self._chromeos_interface,
                            'ec_root_key.vpubk',
                            '/usr/share/vboot/devkeys',
                            'ec')
        self._ec_image.new_image(ec_path)

    def _bios_get_EC_image_sha(self):
        """Get SHA1 hash of RW firmware section of the EC autest image."""
        return self._ec_image.get_section_sha('rw')

    def _bios_update_EC_from_image(self, section, flags):
        """Update EC via software sync design.

        It copys the RW section from the EC image, which is loaded by calling
        bios_setup_EC_image(), to the EC area of the specified RW section on the
        current AP firmware.

        @param section: A firmware section on current BIOS, either 'a' or 'b'.
        @param flags: An integer of preamble flags.
        """
        blob = self._ec_image.get_section_body('rw')
        self._bios_handler.set_section_ecbin(section, blob,
                                             write_through=True)
        self._bios_set_preamble_flags(section, flags)

    def _bios_dump_whole(self, bios_path):
        """Dump the current BIOS firmware to a file, specified by bios_path.

        @param bios_path: The path of the BIOS image to be written.
        """
        self._bios_handler.dump_whole(bios_path)

    def _bios_dump_rw(self, dir_path):
        """Dump the current BIOS firmware RW to dir_path.

        VBOOTA, VBOOTB, FVMAIN, FVMAINB need to be dumped.

        @param dir_path: The path of directory which contains files to be
                         written.
        """
        if not os.path.isdir(dir_path):
            raise Exception("%s doesn't exist" % dir_path)

        VBOOTA_blob = self._bios_handler.get_section_sig('a')
        VBOOTB_blob = self._bios_handler.get_section_sig('b')
        FVMAIN_blob = self._bios_handler.get_section_body('a')
        FVMAINB_blob = self._bios_handler.get_section_body('b')

        open(os.path.join(dir_path, 'VBOOTA'), 'w').write(VBOOTA_blob)
        open(os.path.join(dir_path, 'VBOOTB'), 'w').write(VBOOTB_blob)
        open(os.path.join(dir_path, 'FVMAIN'), 'w').write(FVMAIN_blob)
        open(os.path.join(dir_path, 'FVMAINB'), 'w').write(FVMAINB_blob)

    def _bios_write_whole(self, bios_path):
        """Write the firmware from bios_path to the current system.

        @param bios_path: The path of the source BIOS image.
        """
        self._bios_handler.new_image(bios_path)
        self._bios_handler.write_whole()

    def _bios_write_rw(self, dir_path):
        """Write the firmware RW from dir_path to the current system.

        VBOOTA, VBOOTB, FVMAIN, FVMAINB need to be written.

        @param dir_path: The path of directory which contains the source files.
        """
        if not os.path.exists(os.path.join(dir_path, 'VBOOTA')) or \
           not os.path.exists(os.path.join(dir_path, 'VBOOTB')) or \
           not os.path.exists(os.path.join(dir_path, 'FVMAIN')) or \
           not os.path.exists(os.path.join(dir_path, 'FVMAINB')):
            raise Exception("Source firmware file(s) doesn't exist.")

        VBOOTA_blob = open(os.path.join(dir_path, 'VBOOTA'), 'rb').read()
        VBOOTB_blob = open(os.path.join(dir_path, 'VBOOTB'), 'rb').read()
        FVMAIN_blob = open(os.path.join(dir_path, 'FVMAIN'), 'rb').read()
        FVMAINB_blob = open(os.path.join(dir_path, 'FVMAINB'), 'rb').read()

        self._bios_handler.set_section_sig('a', VBOOTA_blob,
                                           write_through=True)
        self._bios_handler.set_section_sig('b', VBOOTB_blob,
                                           write_through=True)
        self._bios_handler.set_section_body('a', FVMAIN_blob,
                                            write_through=True)
        self._bios_handler.set_section_body('b', FVMAINB_blob,
                                            write_through=True)

    def _ec_get_version(self):
        """Get EC version via mosys.

        @return: A string of the EC version.
        """
        return self._chromeos_interface.run_shell_command_get_output(
                'mosys ec info | sed "s/.*| //"')[0]

    def _ec_get_firmware_sha(self):
        """Get SHA1 hash of EC RW firmware section."""
        return self._ec_handler.get_section_sha('rw')

    @allow_multiple_section_input
    def _ec_corrupt_sig(self, section):
        """Corrupt the requested EC section signature.

        @param section: A EC section, either 'a' or 'b'.
        """
        self._ec_handler.corrupt_firmware(section, corrupt_all=True)

    @allow_multiple_section_input
    def _ec_restore_sig(self, section):
        """Restore the previously corrupted EC section signature.

        @param section: An EC section, either 'a' or 'b'.
        """
        self._ec_handler.restore_firmware(section, restore_all=True)

    @allow_multiple_section_input
    def _ec_corrupt_body(self, section):
        """Corrupt the requested EC section body.

        @param section: An EC section, either 'a' or 'b'.
        """
        self._ec_handler.corrupt_firmware_body(section, corrupt_all=True)

    @allow_multiple_section_input
    def _ec_restore_body(self, section):
        """Restore the previously corrupted EC section body.

        @param section: An EC section, either 'a' or 'b'.
        """
        self._ec_handler.restore_firmware_body(section, restore_all=True)

    def _ec_dump_firmware(self, ec_path):
        """Dump the current EC firmware to a file, specified by ec_path.

        @param ec_path: The path of the EC image to be written.
        """
        self._ec_handler.dump_whole(ec_path)

    def _ec_set_write_protect(self, enable):
        """Enable write protect of the EC flash chip.

        @param enable: True if activating EC write protect. Otherwise, False.
        """
        if enable:
            self._ec_handler.enable_write_protect()
        else:
            self._ec_handler.disable_write_protect()

    @allow_multiple_section_input
    def _kernel_corrupt_sig(self, section):
        """Corrupt the requested kernel section.

        @param section: A kernel section, either 'a' or 'b'.
        """
        self._kernel_handler.corrupt_kernel(section)

    @allow_multiple_section_input
    def _kernel_restore_sig(self, section):
        """Restore the requested kernel section (previously corrupted).

        @param section: A kernel section, either 'a' or 'b'.
        """
        self._kernel_handler.restore_kernel(section)

    def __kernel_modify_version(self, section, delta):
        """Modify kernel version for the requested section, by adding delta.

        The passed in delta, a positive or a negative number, is added to the
        original kernel version.
        """
        original_version = self._kernel_handler.get_version(section)
        new_version = original_version + delta
        self._chromeos_interface.log(
                'Setting kernel section %s version from %d to %d' % (
                section, original_version, new_version))
        self._kernel_handler.set_version(section, new_version)

    @allow_multiple_section_input
    def _kernel_move_version_backward(self, section):
        """Decrement kernel version for the requested section."""
        self.__kernel_modify_version(section, -1)

    @allow_multiple_section_input
    def _kernel_move_version_forward(self, section):
        """Increase kernel version for the requested section."""
        self.__kernel_modify_version(section, 1)

    def _kernel_get_version(self, section):
        """Return kernel version."""
        return self._kernel_handler.get_version(section)

    def _kernel_get_datakey_version(self, section):
        """Return kernel datakey version."""
        return self._kernel_handler.get_datakey_version(section)

    def _kernel_diff_a_b(self):
        """Compare kernel A with B.

        @return: True: if kernel A is different with B.
                 False: if kernel A is the same as B.
        """
        rootdev = self._chromeos_interface.get_root_dev()
        kernel_a = self._chromeos_interface.join_part(rootdev, '2')
        kernel_b = self._chromeos_interface.join_part(rootdev, '4')

        # The signature (some kind of hash) for the kernel body is stored in
        # the beginning. So compare the first 64KB (including header, preamble,
        # and signature) should be enough to check them identical.
        header_a = self._chromeos_interface.read_partition(kernel_a, 0x10000)
        header_b = self._chromeos_interface.read_partition(kernel_b, 0x10000)

        return header_a != header_b

    def _kernel_resign_with_keys(self, section, key_path=None):
        """Resign kernel with temporary key."""
        self._kernel_handler.resign_kernel(section, key_path)

    def _kernel_dump(self, section, kernel_path):
        """Dump the specified kernel to a file.

        @param section: The kernel to dump. May be A or B.
        @param kernel_path: The path to the kernel image to be written.
        """
        self._kernel_handler.dump_kernel(section, kernel_path)

    def _kernel_write(self, section, kernel_path):
        """Write a kernel image to the specified section.

        @param section: The kernel to dump. May be A or B.
        @param kernel_path: The path to the kernel image.
        """
        self._kernel_handler.write_kernel(section, kernel_path)

    def _kernel_get_sha(self, section):
        """Return the SHA1 hash of the specified kernel section."""
        return self._kernel_handler.get_sha(section)

    def _tpm_get_firmware_version(self):
        """Retrieve tpm firmware body version."""
        return self._tpm_handler.get_fw_version()

    def _tpm_get_firmware_datakey_version(self):
        """Retrieve tpm firmware data key version."""
        return self._tpm_handler.get_fw_body_version()

    def _cgpt_get_attributes(self):
        """Get kernel attributes."""
        rootdev = self._system_get_root_dev()
        self._cgpt_handler.read_device_info(rootdev)
        return {'A': self._cgpt_handler.get_partition(rootdev, 'KERN-A'),
                'B': self._cgpt_handler.get_partition(rootdev, 'KERN-B')}

    def _cgpt_set_attributes(self, attributes):
        """Set kernel attributes."""
        rootdev = self._system_get_root_dev()
        allowed = ['priority', 'tries', 'successful']
        for p in ('A', 'B'):
            if p not in attributes:
                continue
            attr = dict()
            for k in allowed:
                if k in attributes[p]:
                    attr[k] = attributes[p][k]
            if attr:
                self._cgpt_handler.set_partition(rootdev, 'KERN-%s' % p, attr)

    def _updater_setup(self, shellball=None):
        """Setup the updater.

        @param shellball: Path of provided shellball. Use default shellball
                          if None,
        """
        self._updater.setup(self._chromeos_interface, shellball)

    def _updater_cleanup(self):
        self._updater.cleanup_temp_dir()

    def _updater_get_fwid(self):
        """Retrieve shellball's fwid.

        This method should be called after updater_setup.

        @return: Shellball's fwid.
        """
        return self._updater.retrieve_fwid()

    def _updater_resign_firmware(self, version):
        """Resign firmware with version.

        @param version: new version number.
        """
        self._updater.resign_firmware(version)

    def _updater_repack_shellball(self, append):
        """Repack shellball with new fwid.

        @param append: use for new fwid naming.
        """
        self._updater.repack_shellball(append)

    def _updater_run_autoupdate(self, append):
        """Run chromeos-firmwareupdate with autoupdate mode."""
        options = ['--noupdate_ec', '--nocheck_rw_compatible']
        self._updater.run_firmwareupdate(mode='autoupdate',
                                         updater_append=append,
                                         options=options)

    def _updater_run_factory_install(self):
        """Run chromeos-firmwareupdate with factory_install mode."""
        options = ['--noupdate_ec']
        self._updater.run_firmwareupdate(mode='factory_install',
                                         options=options)

    def _updater_run_bootok(self, append):
        """Run chromeos-firmwareupdate with bootok mode."""
        self._updater.run_firmwareupdate(mode='bootok',
                                         updater_append=append)

    def _updater_run_recovery(self):
        """Run chromeos-firmwareupdate with recovery mode."""
        options = ['--noupdate_ec', '--nocheck_rw_compatible']
        self._updater.run_firmwareupdate(mode='recovery',
                                         options=options)

    def _updater_get_temp_path(self):
        """Get updater's temp directory path."""
        return self._updater.get_temp_path()

    def _updater_get_keys_path(self):
        """Get updater's keys directory path."""
        return self._updater.get_keys_path()

    def _updater_get_work_path(self):
        """Get updater's work directory path."""
        return self._updater.get_work_path()

    def _rootfs_verify_rootfs(self, section):
        """Verifies the integrity of the root FS.

        @param section: The rootfs to verify. May be A or B.
        """
        return self._rootfs_handler.verify_rootfs(section)

    def _system_check_keys(self, expected_sequence):
        """Check the keys sequence was as expected.

        @param expected_sequence: A list of expected key sequences.
        """
        return self._check_keys.check_keys(expected_sequence)

    def cleanup(self):
        """Cleanup for the RPC server. Currently nothing."""
        pass