Source code for qubesadmin.tools.qvm_backup

# -*- encoding: utf8 -*-
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2017 Marek Marczykowski-Górecki
#                               <[email protected]>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with this program; if not, see <http://www.gnu.org/licenses/>.

'''qvm-backup tool'''

import asyncio
import functools
import getpass
import os
import signal
import sys
import yaml

try:
    import qubesadmin.events
    have_events = True
except ImportError:
    have_events = False
import qubesadmin.tools
from qubesadmin.exc import QubesException

backup_profile_dir = '/etc/qubes/backup'

parser = qubesadmin.tools.QubesArgumentParser()

parser.add_argument("--yes", "-y", action="store_true",
    dest="yes", default=False,
    help="Do not ask for confirmation")

group = parser.add_mutually_exclusive_group()
group.add_argument('--profile', action='store',
    help='Perform backup defined by a given profile')
no_profile = group.add_argument_group('Profile setup',
    'Manually specify profile options')
no_profile.add_argument("--exclude", "-x", action="append",
    dest="exclude_list", default=[],
    help="Exclude the specified VM from the backup (may be "
         "repeated)")
no_profile.add_argument("--dest-vm", "-d", action="store",
    dest="appvm", default=None,
    help="Specify the destination VM to which the backup "
         "will be sent (implies -e)")
no_profile.add_argument("--encrypt", "-e", action="store_true",
    dest="encrypted", default=True,
    help="Ignored, backup is always encrypted")
no_profile.add_argument("--passphrase-file", "-p", action="store",
    dest="passphrase_file", default=None,
    help="Read passphrase from a file, or use '-' to read "
         "from stdin")
no_profile.add_argument("--compress", "-z", action="store_true",
    dest="compression", default=True,
    help="Compress the backup (default)")
no_profile.add_argument("--no-compress", action="store_false",
    dest="compression",
    help="Do not compress the backup")
no_profile.add_argument("--compress-filter", "-Z", action="store",
    dest="compression",
    help="Specify a non-default compression filter program "
         "(default: gzip)")
no_profile.add_argument('--save-profile', action='store',
    help='Save profile under selected name for further use.'
         'Available only in dom0.')

no_profile.add_argument("backup_location", action="store", default=None,
    nargs='?',
    help="Backup location (absolute directory path, "
         "or command to pipe backup to)")

no_profile.add_argument("vms", nargs="*", action=qubesadmin.tools.VmNameAction,
    help="Backup only those VMs")


[docs]def write_backup_profile(output_stream, args, passphrase=None): '''Format backup profile and print it to *output_stream* (a file or stdout) :param output_stream: file-like object ro print the profile to :param args: parsed arguments :param passphrase: passphrase to use ''' profile_data = {} profile_data['include'] = args.vms or None if args.exclude_list: profile_data['exclude'] = args.exclude_list if passphrase: profile_data['passphrase_text'] = passphrase profile_data['compression'] = args.compression if args.appvm: profile_data['destination_vm'] = args.appvm else: profile_data['destination_vm'] = 'dom0' profile_data['destination_path'] = args.backup_location yaml.safe_dump(profile_data, output_stream)
[docs]def main(args=None, app=None): '''Main function of qvm-backup tool''' args = parser.parse_args(args, app=app) profile_path = None if args.profile is None: if args.backup_location is None: parser.error('either --profile or \'backup_location\' is required') if args.app.qubesd_connection_type == 'socket': # when running in dom0, we can create backup profile, including # passphrase if args.save_profile: profile_name = args.save_profile else: # don't care about collisions because only the user in dom0 can # trigger this, and qrexec policy should not allow random VM # to execute the same backup in the meantime profile_name = 'backup-run-{}'.format(os.getpid()) # first write the backup profile without passphrase, to display # summary profile_path = os.path.join( backup_profile_dir, profile_name + '.conf') with open(profile_path, 'w') as f_profile: write_backup_profile(f_profile, args) else: if args.save_profile: parser.error( 'Cannot save backup profile when running not in dom0') # unreachable - parser.error terminate the process return 1 print('To perform the backup according to selected options, ' 'create backup profile ({}) in dom0 with following ' 'content:'.format( os.path.join(backup_profile_dir, 'profile_name.conf'))) write_backup_profile(sys.stdout, args) print('# specify backup passphrase below') print('passphrase_text: ...') return 1 else: profile_name = args.profile try: backup_summary = args.app.qubesd_call( 'dom0', 'admin.backup.Info', profile_name) print(backup_summary.decode()) except QubesException as err: print('\nBackup preparation error: {}'.format(err), file=sys.stderr) return 1 if not args.yes: if input("Do you want to proceed? [y/N] ").upper() != "Y": if args.profile is None and not args.save_profile: os.unlink(profile_path) return 0 if args.profile is None: if args.passphrase_file is not None: pass_f = open(args.passphrase_file) \ if args.passphrase_file != "-" else sys.stdin passphrase = pass_f.readline().rstrip() if pass_f is not sys.stdin: pass_f.close() else: prompt = ("Please enter the passphrase that will be used to " "encrypt and verify the backup: ") passphrase = getpass.getpass(prompt) if getpass.getpass("Enter again for verification: ") != passphrase: parser.error_runtime("Passphrase mismatch!") with open(profile_path, 'w') as f_profile: write_backup_profile(f_profile, args, passphrase) loop = asyncio.get_event_loop() if have_events: # pylint: disable=no-member events_dispatcher = qubesadmin.events.EventsDispatcher(args.app) events_dispatcher.add_handler('backup-progress', functools.partial(print_progress, profile_name)) events_task = asyncio.ensure_future( events_dispatcher.listen_for_events()) loop.add_signal_handler(signal.SIGINT, args.app.qubesd_call, 'dom0', 'admin.backup.Cancel', profile_name) try: loop.run_until_complete(loop.run_in_executor(None, args.app.qubesd_call, 'dom0', 'admin.backup.Execute', profile_name)) except QubesException as err: print('\nBackup error: {}'.format(err), file=sys.stderr) return 1 finally: if have_events: events_task.cancel() try: loop.run_until_complete(events_task) except asyncio.CancelledError: pass loop.close() if args.profile is None and not args.save_profile: os.unlink(profile_path) print('\n') return 0
if __name__ == '__main__': sys.exit(main())