core-admin/qubes/vm/appvm.py
Marek Marczykowski-Górecki dc0e1a5481
vm: do not allow deleting template property from AppVM and DispVM
There is intentionally no default template in terms of qubes.property
definition, to not cause problems when switching global default_template
property - like breaking some VMs, or forcing the user to shutdown all
of them for this. But this also means it shouldn't be allowed to reset
template to "default" value, because it will result in a VM without
template at all.

Fixes QubesOS/qubes-issues#3115
2017-09-29 11:53:00 +02:00

134 lines
5.2 KiB
Python

#
# 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>)
# Copyright (C) 2016 Bahtiar `kalkin-` Gadimov <bahtiar@gadimov.de>
#
# 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.
#
''' This module contains the AppVM implementation '''
import copy
import qubes.events
import qubes.vm.qubesvm
from qubes.config import defaults
class AppVM(qubes.vm.qubesvm.QubesVM):
'''Application VM'''
template = qubes.VMProperty('template',
load_stage=4,
vmclass=qubes.vm.templatevm.TemplateVM,
doc='Template, on which this AppVM is based.')
template_for_dispvms = qubes.property('template_for_dispvms',
type=bool,
default=False,
doc='Should this VM be allowed to start as Disposable VM')
default_volume_config = {
'root': {
'name': 'root',
'snap_on_start': True,
'save_on_stop': False,
'rw': False,
'source': None,
},
'private': {
'name': 'private',
'snap_on_start': False,
'save_on_stop': True,
'rw': True,
'size': defaults['private_img_size'],
},
'volatile': {
'name': 'volatile',
'snap_on_start': False,
'save_on_stop': False,
'size': defaults['root_img_size'],
'rw': True,
},
'kernel': {
'name': 'kernel',
'snap_on_start': False,
'save_on_stop': False,
'rw': False,
}
}
def __init__(self, app, xml, **kwargs):
# migrate renamed properties
if xml is not None:
node_dispvm_allowed = xml.find(
'./properties/property[@name=\'dispvm_allowed\']')
if node_dispvm_allowed is not None:
kwargs['template_for_dispvms'] = \
qubes.property.bool(None, None, node_dispvm_allowed.text)
node_dispvm_allowed.getparent().remove(node_dispvm_allowed)
self.volume_config = copy.deepcopy(self.default_volume_config)
template = kwargs.get('template', None)
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']
super(AppVM, self).__init__(app, xml, **kwargs)
@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
@qubes.events.handler('property-pre-del:template')
def on_property_pre_del_template(self, event, name, oldvalue=None):
'''Forbid deleting template of running VM
''' # pylint: disable=unused-argument,no-self-use
raise qubes.exc.QubesValueError('Cannot unset template')
@qubes.events.handler('property-pre-set:template')
def on_property_pre_set_template(self, event, name, newvalue,
oldvalue=None):
'''Forbid changing template of running VM
''' # pylint: disable=unused-argument
if not self.is_halted():
raise qubes.exc.QubesVMNotHaltedError(self,
'Cannot change template while qube is running')
@qubes.events.handler('property-set:template')
def on_property_set_template(self, event, name, newvalue, oldvalue=None):
''' Adjust root (and possibly other snap_on_start=True) volume
on template change.
''' # pylint: disable=unused-argument
for volume_name, conf in self.default_volume_config.items():
if conf.get('snap_on_start', False) and \
conf.get('source', None) is None:
config = conf.copy()
self.volume_config[volume_name] = config
self.storage.init_volume(volume_name, config)