#!/usr/bin/python2 -O # vim: fileencoding=utf-8 # # The Qubes OS Project, https://www.qubes-os.org/ # # Copyright (C) 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. # from __future__ import absolute_import import os import os.path import re import subprocess import lxml.etree import qubes import qubes.config import qubes.storage import qubes.vm.templatevm class XenStorage(qubes.storage.Storage): '''Class for VM storage of Xen VMs. ''' root_dev = 'xvda' private_dev = 'xvdb' volatile_dev = 'xvdc' modules_dev = 'xvdd' def __init__(self, vm, vmdir, **kwargs): """ Instantiate the storage. Args: vm: a QubesVM vmdir: the root directory of the pool """ assert vm is not None assert vmdir is not None super(XenStorage, self).__init__(vm, **kwargs) self.vmdir = vmdir @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 rootcow_img(self): '''Path to the root COW image''' if isinstance(self.vm, qubes.vm.templatevm.TemplateVM): return self.abspath(qubes.config.vm_files['rootcow_img']) return None @property def volatile_img(self): '''Path to the volatile image''' return self.abspath(qubes.config.vm_files['volatile_img']) def format_disk_dev(self, path, vdev, script=None, rw=True, devtype='disk', domain=None): if path is None: return '' element = lxml.etree.Element('disk') element.set('type', 'block') element.set('device', devtype) element.append(lxml.etree.Element('driver', name='phy')) element.append(lxml.etree.Element('source', dev=path)) element.append(lxml.etree.Element('target', dev=vdev)) if not rw: element.append(lxml.etree.Element('readonly')) if domain is not None: # XXX vm.name? element.append(lxml.etree.Element('domain', name=domain)) if script: element.append(lxml.etree.Element('script', path=script)) # TODO return element return lxml.etree.tostring(element) def root_dev_config(self): if isinstance(self.vm, qubes.vm.templatevm.TemplateVM): return self.format_disk_dev( '{root}:{rootcow}'.format( root=self.root_img, rootcow=self.rootcow_img), self.root_dev, script='block-origin') elif self.vm.hvm and hasattr(self.vm, 'template'): # HVM template-based VM - only one device-mapper layer, in dom0 # (root+volatile) # HVM detection based on 'kernel' property is massive hack, # but taken from assumption that VM needs Qubes-specific kernel # (actually initramfs) to assemble the second layer of device-mapper return self.format_disk_dev( '{root}:{volatile}'.format( root=self.vm.template.storage.root_img, volatile=self.volatile_img), self.root_dev, script='block-snapshot') elif hasattr(self.vm, 'template'): # any other template-based VM - two device-mapper layers: one # in dom0 (here) from root+root-cow, and another one from # this+volatile.img return self.format_disk_dev( '{root}:{template_rootcow}'.format( root=self.root_img, template_rootcow=self.vm.template.storage.rootcow_img), self.root_dev, script='block-snapshot', rw=False) else: # standalone qube return self.format_disk_dev(self.root_img, self.root_dev) def private_dev_config(self): return self.format_disk_dev(self.private_img, self.private_dev) def volatile_dev_config(self): return self.format_disk_dev(self.volatile_img, self.volatile_dev) def create_on_disk_private_img(self, source_template=None): if source_template is None: f_private = open(self.private_img, 'a+b') f_private.truncate(self.private_img_size) f_private.close() else: self.vm.log.info("Copying the template's private image: {}".format( source_template.private_img)) self._copy_file(source_template.private_img, self.private_img) def create_on_disk_root_img(self, source_template=None): if source_template is None: fd = open(self.root_img, 'a+b') fd.truncate(self.root_img_size) fd.close() elif self.vm.updateable: # if not updateable, just use template's disk self.vm.log.info("--> Copying the template's root image: {}".format( source_template.root_img)) self._copy_file(source_template.root_img, self.root_img) def resize_private_img(self, size): fd = open(self.private_img, 'a+b') fd.truncate(size) fd.close() # find loop device if any p = subprocess.Popen( ['sudo', 'losetup', '--associated', self.private_img], stdout=subprocess.PIPE) result = p.communicate() m = re.match(r'^(/dev/loop\d+):\s', result[0]) if m is not None: loop_dev = m.group(1) # resize loop device subprocess.check_call( ['sudo', 'losetup', '--set-capacity', loop_dev]) def commit_template_changes(self): assert isinstance(self.vm, qubes.vm.templatevm.TemplateVM) # TODO: move rootcow_img to this class; the same for vm.is_outdated() if os.path.exists(self.vm.rootcow_img): os.rename(self.vm.rootcow_img, self.vm.rootcow_img + '.old') old_umask = os.umask(002) f_cow = open(self.vm.rootcow_img, 'w') f_root = open(self.root_img, 'r') f_root.seek(0, os.SEEK_END) # make empty sparse file of the same size as root.img f_cow.truncate(f_root.tell()) f_cow.close() f_root.close() os.umask(old_umask) def reset_volatile_storage(self): try: # no template set, in any way (Standalone VM, Template VM) if self.vm.template is None: raise AttributeError # template-based HVM with only one device-mapper layer - # volatile.img used as upper layer on root.img, no root-cow.img # intermediate layer if self.vm.hvm: if os.path.exists(self.volatile_img): if self.vm.debug: if os.path.getmtime(self.vm.template.storage.root_img) \ > os.path.getmtime(self.volatile_img): self.vm.log.warning( 'Template have changed, resetting root.img') else: self.vm.log.warning( 'Debug mode: not resetting root.img; if you' ' want to force root.img reset, either' ' update template VM, or remove volatile.img' ' file.') return os.remove(self.volatile_img) # FIXME stat on f_root; with open() ... f_volatile = open(self.volatile_img, "w") f_root = open(self.vm.template.storage.root_img, "r") # make empty sparse file of the same size as root.img f_root.seek(0, os.SEEK_END) f_volatile.truncate(f_root.tell()) f_volatile.close() f_root.close() return # XXX why is that? super() does not run except AttributeError: # self.vm.template pass super(XenStorage, self).reset_volatile_storage() def prepare_for_vm_startup(self): super(XenStorage, self).prepare_for_vm_startup() if self.drive is not None: # pylint: disable=unused-variable (drive_type, drive_domain, drive_path) = self.drive.split(":") if drive_domain.lower() != "dom0": # XXX "VM '{}' holding '{}' does not exists".format( drive_vm = self.vm.app.domains[drive_domain] if not drive_vm.is_running(): raise qubes.exc.QubesVMNotRunningError(drive_vm, 'VM {!r} holding {!r} isn\'t running'.format( drive_domain, drive_path)) if self.rootcow_img and not os.path.exists(self.rootcow_img): self.commit_template_changes() class XenPool(qubes.storage.Pool): def get_storage(self): """ Returns an instantiated ``XenStorage``. """ return XenStorage(self.vm, vmdir=self.vmdir)