core-admin/qubes/storage/__init__.py
2015-06-29 17:39:28 +02:00

255 lines
8.4 KiB
Python

#!/usr/bin/python2 -O
# vim: fileencoding=utf-8
#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2013-2015 Joanna Rutkowska <joanna@invisiblethingslab.com>
# Copyright (C) 2013-2015 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
# Copyright (C) 2015 Wojtek Porczyk <woju@invisiblethingslab.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
from __future__ import absolute_import
import importlib
import os
import os.path
import re
import shutil
import subprocess
import sys
import qubes
import qubes.utils
class VMStorage(object):
'''Class for handling VM virtual disks.
This is base class for all other implementations, mostly with Xen on Linux
in mind.
''' # pylint: disable=abstract-class-little-used
def __init__(self, vm, private_img_size=None, root_img_size=None,
modules_img=None, modules_img_rw=False):
#: Domain for which we manage storage
self.vm = vm
#: Size of the private image
self.private_img_size = private_img_size \
if private_img_size is not None \
else qubes.config.defaults['private_img_size']
#: Size of the root image
self.root_img_size = root_img_size \
if root_img_size is not None \
else qubes.config.defaults['root_img_size']
# For now compute this path still in QubesVm
self.modules_img = modules_img
self.modules_img_rw = modules_img_rw
#: Additional drive (currently used only by HVM)
self.drive = None
@property
def private_img(self):
'''Path to the private image'''
return self.abspath(qubes.config.vm_files['private_img'])
@property
def root_img(self):
'''Path to the root image'''
return self.vm.template.root_img if hasattr(self.vm, 'template') \
else self.abspath(qubes.config.vm_files['root_img'])
@property
def volatile_img(self):
'''Path to the volatile image'''
return self.abspath(qubes.config.vm_files['volatile_img'])
def abspath(self, path, rel=None):
'''Make absolute path.
If given path is relative, it is interpreted as relative to
:py:attr:`self.vm.dir_path` or given *rel*.
'''
return path if os.path.isabs(path) \
else os.path.join(rel or self.vm.dir_path, path)
def get_config_params(self):
raise NotImplementedError()
@staticmethod
def _copy_file(source, destination):
'''Effective file copy, preserving sparse files etc.
'''
# TODO: Windows support
# We prefer to use Linux's cp, because it nicely handles sparse files
try:
subprocess.check_call(['cp', source, destination])
except subprocess.CalledProcessError:
raise IOError('Error while copying {!r} to {!r}'.format(
source, destination))
def get_disk_utilization(self):
return qubes.utils.get_disk_usage(self.vm.dir_path)
def get_disk_utilization_private_img(self):
# pylint: disable=invalid-name
return qubes.utils.get_disk_usage(self.private_img)
def get_private_img_sz(self):
if not os.path.exists(self.private_img):
return 0
return os.path.getsize(self.private_img)
def resize_private_img(self, size):
raise NotImplementedError()
def create_on_disk_private_img(self, source_template=None):
raise NotImplementedError()
def create_on_disk_root_img(self, source_template=None):
raise NotImplementedError()
def create_on_disk(self, source_template=None):
if source_template is None:
source_template = self.vm.template
old_umask = os.umask(002)
self.vm.log.info('Creating directory: {0}'.format(self.vm.dir_path))
os.mkdir(self.vm.dir_path)
self.create_on_disk_private_img(source_template)
self.create_on_disk_root_img(source_template)
self.reset_volatile_storage(source_template)
os.umask(old_umask)
def clone_disk_files(self, src_vm):
self.vm.log.info('Creating directory: {0}'.format(self.vm.dir_path))
os.mkdir(self.vm.dir_path)
if hasattr(src_vm, 'private_img'):
self.vm.log.info('Copying the private image: {} -> {}'.format(
src_vm.private_img, self.vm.private_img))
self._copy_file(src_vm.private_img, self.vm.private_img)
if src_vm.updateable and hasattr(src_vm, 'root_img'):
self.vm.log.info('Copying the root image: {} -> {}'.format(
src_vm.root_img, self.root_img))
self._copy_file(src_vm.root_img, self.root_img)
# TODO: modules?
# XXX which modules? -woju
@staticmethod
def rename(newpath, oldpath):
'''Move storage directory, most likely during domain's rename.
.. note::
The arguments are in different order than in :program:`cp` utility.
.. versionchange:: 3.0
This is now dummy method that just passes everything to
:py:func:`os.rename`.
:param str newpath: New path
:param str oldpath: Old path
'''
os.rename(oldpath, newpath)
def verify_files(self):
if not os.path.exists(self.vm.dir_path):
raise qubes.QubesException(
'VM directory does not exist: {}'.format(self.vm.dir_path))
if hasattr(self.vm, 'root_img') and not os.path.exists(self.root_img):
raise qubes.QubesException(
'VM root image file does not exist: {}'.format(self.root_img))
if hasattr(self.vm, 'private_img') \
and not os.path.exists(self.private_img):
raise qubes.QubesException(
'VM private image file does not exist: {}'.format(
self.private_img))
if self.modules_img is not None \
and not os.path.exists(self.modules_img):
raise qubes.QubesException(
'VM kernel modules image does not exists: {}'.format(
self.modules_img))
def remove_from_disk(self):
shutil.rmtree(self.vm.dir_path)
def reset_volatile_storage(self, source_template=None):
if source_template is None:
source_template = self.vm.template
# Re-create only for template based VMs
if source_template is not None and self.volatile_img:
if os.path.exists(self.volatile_img):
os.remove(self.volatile_img)
# For StandaloneVM create it only if not already exists
# (eg after backup-restore)
if hasattr(self.vm, 'volatile_img') \
and not os.path.exists(self.vm.volatile_img):
self.vm.log.info(
'Creating volatile image: {0}'.format(self.volatile_img))
subprocess.check_call(
[qubes.config.system_path["prepare_volatile_img_cmd"],
self.volatile_img,
str(self.root_img_size / 1024 / 1024)])
def prepare_for_vm_startup(self):
self.reset_volatile_storage()
if hasattr(self.vm, 'private_img') \
and not os.path.exists(self.private_img):
self.vm.log.info('Creating empty VM private image file: {0}'.format(
self.private_img))
self.create_on_disk_private_img()
def get_storage(vm):
'''Factory yielding storage class instances for domains.
:raises ImportError: when storage class specified in config cannot be found
:raises KeyError: when storage class specified in config cannot be found
'''
pkg, cls = qubes.config.defaults['storage_class'].strip().rsplit('.', 1)
# this may raise ImportError or KeyError, that's okay
return importlib.import_module(pkg).__dict__[cls](vm)