#!/usr/bin/python2 -O # vim: fileencoding=utf-8 # # The Qubes OS Project, https://www.qubes-os.org/ # # Copyright (C) 2013-2015 Joanna Rutkowska # Copyright (C) 2013-2015 Marek Marczykowski-Górecki # # Copyright (C) 2015 Wojtek Porczyk # # 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. # """ Qubes storage system""" from __future__ import absolute_import import os import os.path import shutil import subprocess import pkg_resources import qubes import qubes.exc import qubes.utils BLKSIZE = 512 STORAGE_ENTRY_POINT = 'qubes.storage' class StoragePoolException(qubes.exc.QubesException): pass class Storage(object): '''Class for handling VM virtual disks. This is base class for all other implementations, mostly with Xen on Linux in mind. ''' root_img = None private_img = None volatile_img = None modules_dev = None def __init__(self, vm, private_img_size=None, root_img_size=None): #: 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'] #: Additional drive (currently used only by HVM) self.drive = None def get_config_params(self): args = {} args['rootdev'] = self.root_dev_config() args['privatedev'] = self.private_dev_config() args['volatiledev'] = self.volatile_dev_config() args['otherdevs'] = self.other_dev_config() args['kerneldir'] = self.kernels_dir return args def root_dev_config(self): raise NotImplementedError() def private_dev_config(self): raise NotImplementedError() def volatile_dev_config(self): raise NotImplementedError() def other_dev_config(self): if self.modules_img is not None: return BlockDevice(self.modules_img, 'kernel', rw=False) elif self.drive is not None: (drive_type, drive_domain, drive_path) = self.drive.split(":") if drive_type == 'hd': drive_type = 'disk' rw = (drive_type == 'disk') if drive_domain.lower() == "dom0": drive_domain = None return self.format_disk_dev(drive_path, 'other', rw=rw, devtype=drive_type, domain=drive_domain) else: return '' def format_disk_dev(self, path, name, script=None, rw=True, devtype='disk', domain=None): raise NotImplementedError() @property def kernels_dir(self): '''Directory where kernel resides. If :py:attr:`self.vm.kernel` is :py:obj:`None`, the this points inside :py:attr:`self.vm.dir_path` ''' return os.path.join(qubes.config.system_path['qubes_base_dir'], qubes.config.system_path['qubes_kernels_base_dir'], self.vm.kernel)\ if self.vm.kernel is not None \ else os.path.join(self.vm.dir_path, qubes.config.vm_files['kernels_subdir']) @property def modules_img(self): '''Path to image with modules. Depending on domain, this may be global or inside domain's dir. ''' modules_path = os.path.join(self.kernels_dir, 'modules.img') if os.path.exists(modules_path): return modules_path else: return None @property def modules_img_rw(self): ''':py:obj:`True` if module image should be mounted RW, :py:obj:`False` otherwise.''' return self.vm.kernel is None 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) @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', '--reflink=auto', source, destination]) except subprocess.CalledProcessError: raise IOError('Error while copying {!r} to {!r}'.format( source, destination)) def get_disk_utilization(self): return get_disk_usage(self.vm.dir_path) def get_disk_utilization_private_img(self): # pylint: disable=invalid-name return 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 and hasattr(self.vm, 'template'): 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() 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:: 4.0 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.exc.QubesVMError(self.vm, '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.exc.QubesVMError(self.vm, '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.exc.QubesVMError(self.vm, '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.exc.QubesVMError(self.vm, '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): # Re-create only for template based VMs try: if self.vm.template is not None and self.volatile_img: if os.path.exists(self.volatile_img): os.remove(self.volatile_img) except AttributeError: # self.vm.template pass # For StandaloneVM create it only if not already exists # (eg after backup-restore) if hasattr(self, 'volatile_img') \ and not os.path.exists(self.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_disk_usage_one(st): '''Extract disk usage of one inode from its stat_result struct. If known, get real disk usage, as written to device by filesystem, not logical file size. Those values may be different for sparse files. :param os.stat_result st: stat result :returns: disk usage ''' try: return st.st_blocks * BLKSIZE except AttributeError: return st.st_size def get_disk_usage(path): '''Get real disk usage of given path (file or directory). When *path* points to directory, then it is evaluated recursively. This function tries estiate real disk usage. See documentation of :py:func:`get_disk_usage_one`. :param str path: path to evaluate :returns: disk usage ''' try: st = os.lstat(path) except OSError: return 0 ret = get_disk_usage_one(st) # if path is not a directory, this is skipped for dirpath, dirnames, filenames in os.walk(path): for name in dirnames + filenames: ret += get_disk_usage_one(os.lstat(os.path.join(dirpath, name))) return ret class Pool(object): def __init__(self, vm, dir_path): assert vm is not None assert dir_path is not None self.vm = vm self.dir_path = dir_path self.create_dir_if_not_exists(self.dir_path) self.vmdir = self.vmdir_path(vm, self.dir_path) appvms_path = os.path.join(self.dir_path, 'appvms') self.create_dir_if_not_exists(appvms_path) servicevms_path = os.path.join(self.dir_path, 'servicevms') self.create_dir_if_not_exists(servicevms_path) vm_templates_path = os.path.join(self.dir_path, 'vm-templates') self.create_dir_if_not_exists(vm_templates_path) # XXX there is also a class attribute on the domain classes which does # exactly that -- which one should prevail? def vmdir_path(self, vm, pool_dir): """ Returns the path to vmdir depending on the type of the VM. The default QubesOS file storage saves the vm images in three different directories depending on the ``QubesVM`` type: * ``appvms`` for ``QubesAppVm`` or ``QubesHvm`` * ``vm-templates`` for ``QubesTemplateVm`` or ``QubesTemplateHvm`` Args: vm: a QubesVM pool_dir: the root directory of the pool Returns: string (str) absolute path to the directory where the vm files are stored """ if vm.is_template(): subdir = 'vm-templates' elif vm.is_disposablevm(): subdir = 'appvms' return os.path.join(pool_dir, subdir, vm.template.name + '-dvm') else: subdir = 'appvms' return os.path.join(pool_dir, subdir, vm.name) def create_dir_if_not_exists(self, path): """ Check if a directory exists in if not create it. This method does not create any parent directories. """ if not os.path.exists(path): os.mkdir(path) def pool_drivers(): """ Return a list of EntryPoints names """ return [ep.name for ep in pkg_resources.iter_entry_points(STORAGE_ENTRY_POINT)]