core-admin/qubes/vm/__init__.py
Marek Marczykowski-Górecki c99a47d192 vm: fix handling firewall_conf path
It may be (and by default is) path relative to VM directory.
This code will be gone in the final version, after merging firewall
configuration into qubes.xml. But for now have something testable.
2016-03-21 11:43:33 +01:00

653 lines
21 KiB
Python

#!/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 ast
import collections
import datetime
import functools
import itertools
import os
import re
import subprocess
import sys
import xml.parsers.expat
import lxml.etree
import qubes
import qubes.log
import qubes.events
import qubes.tools.qvm_ls
class Features(dict):
'''Manager of the features.
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):
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):
if feature in self:
return self[feature]
if hasattr(self.vm, 'template') and self.vm.template is not None \
and feature in self.vm.template.features:
return self.vm.template.features[feature]
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 DeviceCollection(object):
'''Bag for devices.
Used as default value for :py:meth:`DeviceManager.__missing__` factory.
:param vm: VM for which we manage devices
:param class_: device class
'''
def __init__(self, vm, class_):
self._vm = vm
self._class = class_
self._set = set()
def attach(self, device):
'''Attach (add) device to domain.
:param str device: device identifier (format is class-dependent)
'''
if device in self:
raise KeyError(
'device {!r} of class {} already attached to {!r}'.format(
device, self._class, self._vm))
self._vm.fire_event_pre('device-pre-attached:{}'.format(self._class),
device)
self._set.add(device)
self._vm.fire_event('device-attached:{}'.format(self._class), device)
def detach(self, device):
'''Detach (remove) device from domain.
:param str device: device identifier (format is class-dependent)
'''
if device not in self:
raise KeyError(
'device {!r} of class {} not attached to {!r}'.format(
device, self._class, self._vm))
self._vm.fire_event_pre('device-pre-detached:{}'.format(self._class),
device)
self._set.remove(device)
self._vm.fire_event('device-detached:{}'.format(self._class), device)
def __iter__(self):
return iter(self._set)
def __contains__(self, item):
return item in self._set
def __len__(self):
return len(self._set)
class DeviceManager(dict):
'''Device manager that hold all devices by their classess.
:param vm: VM for which we manage devices
'''
def __init__(self, vm):
super(DeviceManager, self).__init__()
self._vm = vm
def __missing__(self, key):
self[key] = DeviceCollection(self._vm, key)
return self[key]
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 = DeviceManager(self) if devices is None else devices
#: user-specified tags
self.tags = tags or {}
if self.xml is not None:
# features
for node in xml.xpath('./features/service'):
self.features[node.get('name')] = node.text
# devices (pci, usb, ...)
for parent in xml.xpath('./devices'):
devclass = parent.get('class')
for node in parent.xpath('./device'):
self.devices[devclass].attach(node.text)
# tags
for node in xml.xpath('./tags/tag'):
self.tags[node.get('name')] = node.text
# TODO: firewall, policy
# check if properties are appropriate
all_names = set(prop.__name__ for prop in self.property_list())
for node in self.xml.xpath('./properties/property'):
name = node.get('name')
if not name in all_names:
raise TypeError(
'property {!r} not applicable to {!r}'.format(
name, self.__class__.__name__))
#: logger instance for logging messages related to this VM
self.log = None
if hasattr(self, 'name'):
self.init_log()
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('service', name=feature)
node.text = self.features[feature] if feature else None
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]:
node = lxml.etree.Element('device')
node.text = device
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
#
@staticmethod
def lvxml_net_dev(ip, mac, backend):
'''Return ``<interface>`` node for libvirt xml.
This was previously _format_net_dev
:param str ip: IP address of the frontend
:param str mac: MAC (Ethernet) address of the frontend
:param qubes.vm.qubesvm.QubesVM backend: Backend domain
:rtype: lxml.etree._Element
'''
interface = lxml.etree.Element('interface', type='ethernet')
interface.append(lxml.etree.Element('mac', address=mac))
interface.append(lxml.etree.Element('ip', address=ip))
interface.append(lxml.etree.Element('backenddomain', name=backend.name))
interface.append(lxml.etree.Element('script', path="vif-route-qubes"))
return interface
@staticmethod
def lvxml_pci_dev(address):
'''Return ``<hostdev>`` node for libvirt xml.
This was previously _format_pci_dev
:param str ip: IP address of the frontend
:param str mac: MAC (Ethernet) address of the frontend
:param qubes.vm.qubesvm.QubesVM backend: Backend domain
:rtype: lxml.etree._Element
'''
dev_match = re.match(r'([0-9a-f]+):([0-9a-f]+)\.([0-9a-f]+)', address)
if not dev_match:
raise ValueError('Invalid PCI device address: {!r}'.format(address))
hostdev = lxml.etree.Element('hostdev', type='pci', managed='yes')
source = lxml.etree.Element('source')
source.append(lxml.etree.Element('address',
bus='0x' + dev_match.group(1),
slot='0x' + dev_match.group(2),
function='0x' + dev_match.group(3)))
hostdev.append(source)
return hostdev
#
# old libvirt XML
# TODO rewrite it to do proper XML synthesis via lxml.etree
#
def get_config_params(self):
'''Return parameters for libvirt's XML domain config
.. deprecated:: 3.0-alpha This will go away.
'''
args = {}
args['name'] = self.name
args['uuid'] = str(self.uuid)
args['vmdir'] = self.dir_path
args['pcidevs'] = ''.join(lxml.etree.tostring(self.lvxml_pci_dev(dev))
for dev in self.devices['pci'])
args['maxmem'] = str(self.maxmem)
args['vcpus'] = str(self.vcpus)
args['mem'] = str(min(self.memory, self.maxmem))
# If dynamic memory management disabled, set maxmem=mem
if not self.features.get('meminfo-writer', True):
args['maxmem'] = args['mem']
if self.netvm is not None:
args['ip'] = self.ip
args['mac'] = self.mac
args['gateway'] = self.netvm.gateway
for i, addr in zip(itertools.count(start=1), self.dns):
args['dns{}'.format(i)] = addr
args['netmask'] = self.netmask
args['netdev'] = lxml.etree.tostring(
self.lvxml_net_dev(self.ip, self.mac, self.netvm))
args['network_begin'] = ''
args['network_end'] = ''
args['no_network_begin'] = '<!--'
args['no_network_end'] = '-->'
else:
args['ip'] = ''
args['mac'] = ''
args['gateway'] = ''
args['dns1'] = ''
args['dns2'] = ''
args['netmask'] = ''
args['netdev'] = ''
args['network_begin'] = '<!--'
args['network_end'] = '-->'
args['no_network_begin'] = ''
args['no_network_end'] = ''
args.update(self.storage.get_config_params())
if hasattr(self, 'kernelopts'):
args['kernelopts'] = self.kernelopts
if self.debug:
self.log.info(
"Debug mode: adding 'earlyprintk=xen' to kernel opts")
args['kernelopts'] += ' earlyprintk=xen'
return args
def create_config_file(self, file_path=None, prepare_dvm=False):
'''Create libvirt's XML domain config file
If :py:attr:`qubes.vm.qubesvm.QubesVM.uses_custom_config` is true, this
does nothing.
:param str file_path: Path to file to create \
(default: :py:attr:`qubes.vm.qubesvm.QubesVM.conf_file`)
:param bool prepare_dvm: If we are in the process of preparing \
DisposableVM
'''
if file_path is None:
file_path = self.conf_file
# TODO
# if self.uses_custom_config:
# conf_appvm = open(file_path, "r")
# domain_config = conf_appvm.read()
# conf_appvm.close()
# return domain_config
f_conf_template = open(self.config_file_template, 'r')
conf_template = f_conf_template.read()
f_conf_template.close()
template_params = self.get_config_params()
if prepare_dvm:
template_params['name'] = '%NAME%'
template_params['privatedev'] = ''
template_params['netdev'] = re.sub(r"address='[0-9.]*'",
"address='%IP%'", template_params['netdev'])
domain_config = conf_template.format(**template_params)
# FIXME: This is only for debugging purposes
old_umask = os.umask(002)
try:
conf_appvm = open(file_path, "w")
conf_appvm.write(domain_config)
conf_appvm.close()
except: # pylint: disable=bare-except
# Ignore errors
pass
finally:
os.umask(old_umask)
return domain_config
#
# firewall
# TODO rewrite it, have <firewall/> node under <domain/>
# and possibly integrate with generic policy framework
#
def write_firewall_conf(self, conf):
'''Write firewall config file.
'''
defaults = self.get_firewall_conf()
expiring_rules_present = False
for item in defaults.keys():
if item not in conf:
conf[item] = defaults[item]
root = lxml.etree.Element(
"QubesFirewallRules",
policy=("allow" if conf["allow"] else "deny"),
dns=("allow" if conf["allowDns"] else "deny"),
icmp=("allow" if conf["allowIcmp"] else "deny"),
yumProxy=("allow" if conf["allowYumProxy"] else "deny"))
for rule in conf["rules"]:
# For backward compatibility
if "proto" not in rule:
if rule["portBegin"] is not None and rule["portBegin"] > 0:
rule["proto"] = "tcp"
else:
rule["proto"] = "any"
element = lxml.etree.Element(
"rule",
address=rule["address"],
proto=str(rule["proto"]),
)
if rule["netmask"] is not None and rule["netmask"] != 32:
element.set("netmask", str(rule["netmask"]))
if rule.get("portBegin", None) is not None and \
rule["portBegin"] > 0:
element.set("port", str(rule["portBegin"]))
if rule.get("portEnd", None) is not None and rule["portEnd"] > 0:
element.set("toport", str(rule["portEnd"]))
if "expire" in rule:
element.set("expire", str(rule["expire"]))
expiring_rules_present = True
root.append(element)
tree = lxml.etree.ElementTree(root)
try:
old_umask = os.umask(002)
with open(os.path.join(self.dir_path,
self.firewall_conf), 'w') as fd:
tree.write(fd, encoding="UTF-8", pretty_print=True)
fd.close()
os.umask(old_umask)
except EnvironmentError as err: # pylint: disable=broad-except
print >> sys.stderr, "{0}: save error: {1}".format(
os.path.basename(sys.argv[0]), err)
return False
# Automatically enable/disable 'yum-proxy-setup' service based on
# allowYumProxy
if conf['allowYumProxy']:
self.features['yum-proxy-setup'] = '1'
else:
try:
del self.features['yum-proxy-setup']
except KeyError:
pass
if expiring_rules_present:
subprocess.call(["sudo", "systemctl", "start",
"qubes-reload-firewall@%s.timer" % self.name])
return True
def has_firewall(self):
return os.path.exists(os.path.join(self.dir_path, self.firewall_conf))
@staticmethod
def get_firewall_defaults():
return {
'rules': list(),
'allow': True,
'allowDns': True,
'allowIcmp': True,
'allowYumProxy': False}
def get_firewall_conf(self):
conf = self.get_firewall_defaults()
try:
tree = lxml.etree.parse(os.path.join(self.dir_path,
self.firewall_conf))
root = tree.getroot()
conf["allow"] = (root.get("policy") == "allow")
conf["allowDns"] = (root.get("dns") == "allow")
conf["allowIcmp"] = (root.get("icmp") == "allow")
conf["allowYumProxy"] = (root.get("yumProxy") == "allow")
for element in root:
rule = {}
attr_list = ("address", "netmask", "proto", "port", "toport",
"expire")
for attribute in attr_list:
rule[attribute] = element.get(attribute)
if rule["netmask"] is not None:
rule["netmask"] = int(rule["netmask"])
else:
rule["netmask"] = 32
if rule["port"] is not None:
rule["portBegin"] = int(rule["port"])
else:
# backward compatibility
rule["portBegin"] = 0
# For backward compatibility
if rule["proto"] is None:
if rule["portBegin"] > 0:
rule["proto"] = "tcp"
else:
rule["proto"] = "any"
if rule["toport"] is not None:
rule["portEnd"] = int(rule["toport"])
else:
rule["portEnd"] = None
if rule["expire"] is not None:
rule["expire"] = int(rule["expire"])
if rule["expire"] <= int(datetime.datetime.now().strftime(
"%s")):
continue
else:
del rule["expire"]
del rule["port"]
del rule["toport"]
conf["rules"].append(rule)
except EnvironmentError as err: # pylint: disable=broad-except
# problem accessing file, like ENOTFOUND, EPERM or sth
# return default config
return conf
except (xml.parsers.expat.ExpatError,
ValueError, LookupError) as err:
# config is invalid
print("{0}: load error: {1}".format(
os.path.basename(sys.argv[0]), err))
return None
return conf