Source code for qubes.vm.dispvm

#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2014-2016  Wojtek Porczyk <woju@invisiblethingslab.com>
# Copyright (C) 2016       Marek Marczykowski <marmarek@invisiblethingslab.com>)
#
# This library 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 library 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 library; if not, see <https://www.gnu.org/licenses/>.
#

''' A disposable vm implementation '''

import asyncio

import qubes.vm.qubesvm
import qubes.vm.appvm
import qubes.config

[docs]class DispVM(qubes.vm.qubesvm.QubesVM): '''Disposable VM''' template = qubes.VMProperty('template', load_stage=4, vmclass=qubes.vm.appvm.AppVM, doc='AppVM, on which this DispVM is based.') dispid = qubes.property('dispid', type=int, write_once=True, clone=False, doc='''Internal, persistent identifier of particular DispVM.''') auto_cleanup = qubes.property('auto_cleanup', type=bool, default=False, doc='automatically remove this VM upon shutdown') include_in_backups = qubes.property('include_in_backups', type=bool, default=(lambda self: not self.auto_cleanup), doc='If this domain is to be included in default backup.') default_dispvm = qubes.VMProperty('default_dispvm', load_stage=4, allow_none=True, default=(lambda self: self.template), doc='Default VM to be used as Disposable VM for service calls.') def __init__(self, app, xml, *args, **kwargs): self.volume_config = { 'root': { 'name': 'root', 'snap_on_start': True, 'save_on_stop': False, 'rw': True, 'source': None, }, 'private': { 'name': 'private', 'snap_on_start': True, 'save_on_stop': False, 'rw': True, 'source': None, }, 'volatile': { 'name': 'volatile', 'snap_on_start': False, 'save_on_stop': False, 'rw': True, 'size': qubes.config.defaults['root_img_size'] + qubes.config.defaults['private_img_size'], }, 'kernel': { 'name': 'kernel', 'snap_on_start': False, 'save_on_stop': False, 'rw': False, } } template = kwargs.get('template', None) if xml is None: assert template is not None if not getattr(template, 'template_for_dispvms', False): raise qubes.exc.QubesValueError( 'template for DispVM ({}) needs to be an AppVM with ' 'template_for_dispvms=True'.format(template.name)) if 'dispid' not in kwargs: kwargs['dispid'] = app.domains.get_new_unused_dispid() if 'name' not in kwargs: kwargs['name'] = 'disp' + str(kwargs['dispid']) if template is not None: # template is only passed if the AppVM is created, in other cases we # don't need to patch the volume_config because the config is # coming from XML, already as we need it for name, config in template.volume_config.items(): # in case the template vm has more volumes add them to own # config if name not in self.volume_config: self.volume_config[name] = config.copy() if 'vid' in self.volume_config[name]: del self.volume_config[name]['vid'] # copy pool setting from base AppVM; root and private would be # in the same pool anyway (because of snap_on_start), # but not volatile, which could be surprising elif 'pool' not in self.volume_config[name] \ and 'pool' in config: self.volume_config[name]['pool'] = config['pool'] super(DispVM, self).__init__(app, xml, *args, **kwargs) if xml is None: # by default inherit properties from the DispVM template proplist = [prop.__name__ for prop in template.property_list() if prop.clone and prop.__name__ not in ['template']] # Do not overwrite properties that have already been set to a # non-default value. self_props = [prop.__name__ for prop in self.property_list() if self.property_is_default(prop)] self.clone_properties(template, set(proplist).intersection( self_props)) self.firewall.clone(template.firewall) self.features.update(template.features) self.tags.update(template.tags)
[docs] @qubes.events.handler('domain-load') def on_domain_loaded(self, event): ''' When domain is loaded assert that this vm has a template. ''' # pylint: disable=unused-argument assert self.template
[docs] @qubes.events.handler('property-pre-set:template', 'property-pre-reset:template') def on_property_pre_set_template(self, event, name, newvalue=None, oldvalue=None): ''' Disposable VM cannot have template changed ''' # pylint: disable=unused-argument raise qubes.exc.QubesValueError(self, 'Cannot change template of Disposable VM')
[docs] @qubes.events.handler('domain-shutdown') @asyncio.coroutine def on_domain_shutdown(self, _event, **_kwargs): yield from self._auto_cleanup()
@asyncio.coroutine def _auto_cleanup(self): '''Do auto cleanup if enabled''' if self.auto_cleanup and self in self.app.domains: del self.app.domains[self] yield from self.remove_from_disk() self.app.save()
[docs] @classmethod @asyncio.coroutine def from_appvm(cls, appvm, **kwargs): '''Create a new instance from given AppVM :param qubes.vm.appvm.AppVM appvm: template from which the VM should \ be created :returns: new disposable vm *kwargs* are passed to the newly created VM >>> import qubes.vm.dispvm.DispVM >>> dispvm = qubes.vm.dispvm.DispVM.from_appvm(appvm).start() >>> dispvm.run_service('qubes.VMShell', input='firefox') >>> dispvm.cleanup() This method modifies :file:`qubes.xml` file. The qube returned is not started. ''' if not appvm.template_for_dispvms: raise qubes.exc.QubesException( 'Refusing to create DispVM out of this AppVM, because ' 'template_for_dispvms=False') app = appvm.app dispvm = app.add_new_vm( cls, template=appvm, auto_cleanup=True, **kwargs) yield from dispvm.create_on_disk() app.save() return dispvm
[docs] @asyncio.coroutine def cleanup(self): '''Clean up after the DispVM This stops the disposable qube and removes it from the store. This method modifies :file:`qubes.xml` file. ''' try: # pylint: disable=not-an-iterable yield from self.kill() except qubes.exc.QubesVMNotStartedError: pass # if auto_cleanup is set, this will be done automatically if not self.auto_cleanup: del self.app.domains[self] yield from self.remove_from_disk() self.app.save()
[docs] @asyncio.coroutine def start(self, **kwargs): # pylint: disable=arguments-differ try: # sanity check, if template_for_dispvm got changed in the meantime if not self.template.template_for_dispvms: raise qubes.exc.QubesException( 'template for DispVM ({}) needs to have ' 'template_for_dispvms=True'.format(self.template.name)) yield from super(DispVM, self).start(**kwargs) except: # Cleanup also on failed startup yield from self._auto_cleanup() raise
[docs] def create_qdb_entries(self): super().create_qdb_entries() self.untrusted_qdb.write('/qubes-vm-persistence', 'none')