#!/usr/bin/python2 -O
# vim: fileencoding=utf-8
#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2010-2015 Joanna Rutkowska <joanna@invisiblethingslab.com>
# Copyright (C) 2011-2015 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
# Copyright (C) 2014-2015 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.
#
'''Qubes Virtual Machines
'''
import datetime
import os
import subprocess
import sys
import xml.parsers.expat
import lxml.etree
import qubes
import qubes.devices
import qubes.events
import qubes.log
import qubes.tools.qvm_ls
class Features(dict):
'''Manager of the features.
Features can have three distinct values: no value (not present in mapping,
which is closest thing to :py:obj:`None`), empty string (which is
interpreted as :py:obj:`False`) and non-empty string, which is
:py:obj:`True`. Anything assigned to the mapping is coerced to strings,
however if you assign instances of :py:class:`bool`, they are converted as
described above. Be aware that assigning the number `0` (which is considered
false in Python) will result in string `'0'`, which is considered true.
This class inherits from dict, but has most of the methods that manipulate
the item disarmed (they raise NotImplementedError). The ones that are left
fire appropriate events on the qube that owns an instance of this class.
'''
#
# Those are the methods that affect contents. Either disarm them or make
# them report appropriate events. Good approach is to rewrite them carefully
# using official documentation, but use only our (overloaded) methods.
#
def __init__(self, vm, other=None, **kwargs):
super(Features, self).__init__()
self.vm = vm
self.update(other, **kwargs)
def __delitem__(self, key):
super(Features, self).__delitem__(key)
self.vm.fire_event('domain-feature-delete', key)
def __setitem__(self, key, value):
if value is None or isinstance(value, bool):
value = '1' if value else ''
else:
value = str(value)
self.vm.fire_event('domain-feature-set', key, value)
super(Features, self).__setitem__(key, value)
def clear(self):
for key in self:
del self[key]
def pop(self):
'''Not implemented
:raises: NotImplementedError
'''
raise NotImplementedError()
def popitem(self):
'''Not implemented
:raises: NotImplementedError
'''
raise NotImplementedError()
def setdefault(self):
'''Not implemented
:raises: NotImplementedError
'''
raise NotImplementedError()
def update(self, other=None, **kwargs):
if other is not None:
if hasattr(other, 'keys'):
for key in other:
self[key] = other[key]
else:
for key, value in other:
self[key] = value
for key in kwargs:
self[key] = kwargs[key]
#
# end of overriding
#
_NO_DEFAULT = object()
def check_with_template(self, feature, default=_NO_DEFAULT):
''' Check if the vm's template has the specified feature. '''
if feature in self:
return self[feature]
if hasattr(self.vm, 'template') and self.vm.template is not None:
try:
return self.vm.template.features[feature]
except KeyError:
# handle default just below
pass
if default is self._NO_DEFAULT:
raise KeyError(feature)
return default
class BaseVMMeta(qubes.events.EmitterMeta):
'''Metaclass for :py:class:`.BaseVM`'''
def __init__(cls, name, bases, dict_):
super(BaseVMMeta, cls).__init__(name, bases, dict_)
qubes.tools.qvm_ls.process_class(cls)
class BaseVM(qubes.PropertyHolder):
'''Base class for all VMs
:param app: Qubes application context
:type app: :py:class:`qubes.Qubes`
:param xml: xml node from which to deserialise
:type xml: :py:class:`lxml.etree._Element` or :py:obj:`None`
This class is responsible for serializing and deserialising machines and
provides basic framework. It contains no management logic. For that, see
:py:class:`qubes.vm.qubesvm.QubesVM`.
'''
# pylint: disable=no-member
__metaclass__ = BaseVMMeta
def __init__(self, app, xml, features=None, devices=None, tags=None,
**kwargs):
# pylint: disable=redefined-outer-name
# self.app must be set before super().__init__, because some property
# setters need working .app attribute
#: mother :py:class:`qubes.Qubes` object
self.app = app
super(BaseVM, self).__init__(xml, **kwargs)
#: dictionary of features of this qube
self.features = Features(self, features)
#: :py:class:`DeviceManager` object keeping devices that are attached to
#: this domain
self.devices = devices or qubes.devices.DeviceManager(self)
#: user-specified tags
self.tags = tags or {}
#: logger instance for logging messages related to this VM
self.log = None
if hasattr(self, 'name'):
self.init_log()
def load_extras(self):
# features
for node in self.xml.xpath('./features/feature'):
self.features[node.get('name')] = node.text
# devices (pci, usb, ...)
for parent in self.xml.xpath('./devices'):
devclass = parent.get('class')
for node in parent.xpath('./device'):
device = self.devices[devclass].devclass(
self.app.domains[node.get('backend-domain')],
node.get('id')
)
self.devices[devclass].attach(device)
# tags
for node in self.xml.xpath('./tags/tag'):
self.tags[node.get('name')] = node.text
# SEE:1815 firewall, policy.
def init_log(self):
'''Initialise logger for this domain.'''
self.log = qubes.log.get_vm_logger(self.name)
def __xml__(self):
element = lxml.etree.Element('domain')
element.set('id', 'domain-' + str(self.qid))
element.set('class', self.__class__.__name__)
element.append(self.xml_properties())
features = lxml.etree.Element('features')
for feature in self.features:
node = lxml.etree.Element('feature', name=feature)
node.text = self.features[feature]
features.append(node)
element.append(features)
for devclass in self.devices:
devices = lxml.etree.Element('devices')
devices.set('class', devclass)
for device in self.devices[devclass].attached(persistent=True):
node = lxml.etree.Element('device')
node.set('backend-domain', device.backend_domain.name)
node.set('id', device.ident)
devices.append(node)
element.append(devices)
tags = lxml.etree.Element('tags')
for tag in self.tags:
node = lxml.etree.Element('tag', name=tag)
node.text = self.tags[tag]
tags.append(node)
element.append(tags)
return element
def __repr__(self):
proprepr = []
for prop in self.property_list():
try:
proprepr.append('{}={!s}'.format(
prop.__name__, getattr(self, prop.__name__)))
except AttributeError:
continue
return '<{} object at {:#x} {}>'.format(
self.__class__.__name__, id(self), ' '.join(proprepr))
#
# xml serialising methods
#
def create_config_file(self, prepare_dvm=False):
'''Create libvirt's XML domain config file
:param bool prepare_dvm: If we are in the process of preparing \
DisposableVM
'''
domain_config = self.app.env.select_template([
'libvirt/xen/by-name/{}.xml'.format(self.name),
'libvirt/xen-user.xml',
'libvirt/xen-dist.xml',
'libvirt/xen.xml',
]).render(vm=self, prepare_dvm=prepare_dvm)
return domain_config
class VMProperty(qubes.property):
'''Property that is referring to a VM
:param type vmclass: class that returned VM is supposed to be instance of
and all supported by :py:class:`property` with the exception of ``type`` \
and ``setter``
'''
_none_value = ''
def __init__(self, name, vmclass=BaseVM, allow_none=False,
**kwargs):
if 'type' in kwargs:
raise TypeError(
"'type' keyword parameter is unsupported in {}".format(
self.__class__.__name__))
if 'setter' in kwargs:
raise TypeError(
"'setter' keyword parameter is unsupported in {}".format(
self.__class__.__name__))
if not issubclass(vmclass, BaseVM):
raise TypeError(
"'vmclass' should specify a subclass of qubes.vm.BaseVM")
super(VMProperty, self).__init__(name,
saver=(lambda self_, prop, value:
self._none_value if value is None else value.name),
**kwargs)
self.vmclass = vmclass
self.allow_none = allow_none
def __set__(self, instance, value):
if value is self.__class__.DEFAULT:
self.__delete__(instance)
return
if value == self._none_value:
value = None
if value is None:
if self.allow_none:
super(VMProperty, self).__set__(instance, value)
return
else:
raise ValueError(
'Property {!r} does not allow setting to {!r}'.format(
self.__name__, value))
app = instance if isinstance(instance, qubes.Qubes) else instance.app
try:
vm = app.domains[value]
except KeyError:
raise qubes.exc.QubesVMNotFoundError(value)
if not isinstance(vm, self.vmclass):
raise TypeError('wrong VM class: domains[{!r}] is of type {!s} '
'and not {!s}'.format(value,
vm.__class__.__name__,
self.vmclass.__name__))
super(VMProperty, self).__set__(instance, vm)