# # The Qubes OS Project, https://www.qubes-os.org/ # # Copyright (C) 2010-2015 Joanna Rutkowska # Copyright (C) 2011-2015 Marek Marczykowski-Górecki # # Copyright (C) 2014-2015 Wojtek Porczyk # # 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 . # import collections import copy import functools import grp import itertools import logging import os import random import sys import tempfile import time import traceback import uuid import asyncio import jinja2 import libvirt import lxml.etree try: import xen.lowlevel.xs # pylint: disable=wrong-import-order import xen.lowlevel.xc # pylint: disable=wrong-import-order except ImportError: pass if os.name == 'posix': # pylint: disable=wrong-import-order import fcntl elif os.name == 'nt': # pylint: disable=import-error import win32con import win32file import pywintypes else: raise RuntimeError("Qubes works only on POSIX or WinNT systems") # pylint: disable=wrong-import-position import qubes import qubes.ext import qubes.utils import qubes.storage import qubes.storage.reflink import qubes.vm import qubes.vm.adminvm import qubes.vm.qubesvm import qubes.vm.templatevm # pylint: enable=wrong-import-position class VirDomainWrapper: # pylint: disable=too-few-public-methods def __init__(self, connection, vm): self._connection = connection self._vm = vm def _reconnect_if_dead(self): try: is_dead = not self._vm.connect().isAlive() except libvirt.libvirtError as ex: if ex.get_error_code() == libvirt.VIR_ERR_INVALID_CONN: # connection to libvirt was re-established in the meantime is_dead = True else: raise if is_dead: # pylint: disable=protected-access self._connection._reconnect_if_dead() self._vm = self._connection._conn.lookupByUUID(self._vm.UUID()) return is_dead def __getattr__(self, attrname): attr = getattr(self._vm, attrname) if not isinstance(attr, collections.Callable): return attr @functools.wraps(attr) def wrapper(*args, **kwargs): try: return attr(*args, **kwargs) except libvirt.libvirtError: if self._reconnect_if_dead(): return getattr(self._vm, attrname)(*args, **kwargs) raise return wrapper class VirConnectWrapper: # pylint: disable=too-few-public-methods def __init__(self, uri, reconnect_cb=None): self._conn = libvirt.open(uri) self._reconnect_cb = reconnect_cb def _reconnect_if_dead(self): is_dead = not self._conn.isAlive() if is_dead: uri = self._conn.getURI() old_conn = self._conn self._conn = libvirt.open(uri) if callable(self._reconnect_cb): self._reconnect_cb(old_conn) old_conn.close() return is_dead def _wrap_domain(self, ret): if isinstance(ret, libvirt.virDomain): ret = VirDomainWrapper(self, ret) return ret def __getattr__(self, attrname): attr = getattr(self._conn, attrname) if not isinstance(attr, collections.Callable): return attr if attrname == 'close': return attr @functools.wraps(attr) def wrapper(*args, **kwargs): try: return self._wrap_domain(attr(*args, **kwargs)) except libvirt.libvirtError: if self._reconnect_if_dead(): return self._wrap_domain( getattr(self._conn, attrname)(*args, **kwargs)) raise return wrapper class VMMConnection: """Connection to Virtual Machine Manager (libvirt)""" def __init__(self, offline_mode=None, libvirt_reconnect_cb=None): """ :param offline_mode: enable/disable offline mode; default is to enable when running in chroot as root, otherwise disable :param libvirt_reconnect_cb: callable to be called when connection to libvirt is re-established; the callback is called with old connection as argument """ if offline_mode is None: offline_mode = bool(os.getuid() == 0 and os.stat('/') != os.stat('/proc/1/root/.')) self._offline_mode = offline_mode self._libvirt_reconnect_cb = libvirt_reconnect_cb self._libvirt_conn = None self._xs = None self._xc = None @property def offline_mode(self): """Check or enable offline mode (do not actually connect to vmm)""" return self._offline_mode def _libvirt_error_handler(self, ctx, error): pass def init_vmm_connection(self): """Initialise connection This method is automatically called when getting""" if self._libvirt_conn is not None: # Already initialized return if self._offline_mode: # Do not initialize in offline mode raise qubes.exc.QubesException( 'VMM operations disabled in offline mode') if 'xen.lowlevel.xs' in sys.modules: self._xs = xen.lowlevel.xs.xs() if 'xen.lowlevel.xc' in sys.modules: self._xc = xen.lowlevel.xc.xc() self._libvirt_conn = VirConnectWrapper( qubes.config.defaults['libvirt_uri'], reconnect_cb=self._libvirt_reconnect_cb) libvirt.registerErrorHandler(self._libvirt_error_handler, None) @property def libvirt_conn(self): """Connection to libvirt""" self.init_vmm_connection() return self._libvirt_conn @property def xs(self): """Connection to Xen Store This property in available only when running on Xen. """ # XXX what about the case when we run under KVM, # but xen modules are importable? if 'xen.lowlevel.xs' not in sys.modules: raise AttributeError( 'xs object is available under Xen hypervisor only') self.init_vmm_connection() return self._xs @property def xc(self): """Connection to Xen This property in available only when running on Xen. """ # XXX what about the case when we run under KVM, # but xen modules are importable? if 'xen.lowlevel.xc' not in sys.modules: raise AttributeError( 'xc object is available under Xen hypervisor only') self.init_vmm_connection() return self._xc def close(self): libvirt.registerErrorHandler(None, None) if self._xs: self._xs.close() self._xs = None if self._libvirt_conn: self._libvirt_conn.close() self._libvirt_conn = None self._xc = None # and pray it will get garbage-collected class QubesHost: """Basic information about host machine :param qubes.Qubes app: Qubes application context (must have \ :py:attr:`Qubes.vmm` attribute defined) """ def __init__(self, app): self.app = app self._no_cpus = None self._total_mem = None self._physinfo = None def _fetch(self): if self._no_cpus is not None: return # pylint: disable=unused-variable (model, memory, cpus, mhz, nodes, socket, cores, threads) = \ self.app.vmm.libvirt_conn.getInfo() self._total_mem = int(memory) * 1024 self._no_cpus = cpus self.app.log.debug('QubesHost: no_cpus={} memory_total={}'.format( self.no_cpus, self.memory_total)) try: self.app.log.debug('QubesHost: xen_free_memory={}'.format( self.get_free_xen_memory())) except NotImplementedError: pass @property def memory_total(self): """Total memory, in kbytes""" if self.app.vmm.offline_mode: return 2 ** 64 - 1 self._fetch() return self._total_mem @property def no_cpus(self): """Number of CPUs""" if self.app.vmm.offline_mode: return 42 self._fetch() return self._no_cpus def get_free_xen_memory(self): """Get free memory from Xen's physinfo. :raises NotImplementedError: when not under Xen """ try: self._physinfo = self.app.xc.physinfo() except AttributeError: raise NotImplementedError('This function requires Xen hypervisor') return int(self._physinfo['free_memory']) def get_vm_stats(self, previous_time=None, previous=None, only_vm=None): """Measure cpu usage for all domains at once. If previous measurements are given, CPU usage will be given in percents of time. Otherwise only absolute value (seconds). Return a tuple of (measurements_time, measurements), where measurements is a dictionary with key: domid, value: dict: - cpu_time - absolute CPU usage (seconds since its startup) - cpu_usage_raw - CPU usage in % - cpu_usage - CPU usage in % (normalized to number of vcpus) - memory_kb - current memory assigned, in kb This function requires Xen hypervisor. ..warning: This function may return info about implementation-specific VMs, like stubdomains for HVM :param previous: previous measurement :param previous_time: time of previous measurement :param only_vm: get measurements only for this VM :raises NotImplementedError: when not under Xen """ if (previous_time is None) != (previous is None): raise ValueError( 'previous and previous_time must be given together (or none)') if previous is None: previous = {} current_time = time.time() current = {} try: if only_vm: xid = only_vm.xid if xid < 0: raise qubes.exc.QubesVMNotRunningError(only_vm) info = self.app.vmm.xc.domain_getinfo(xid, 1) if info[0]['domid'] != xid: raise qubes.exc.QubesVMNotRunningError(only_vm) else: info = self.app.vmm.xc.domain_getinfo(0, 1024) except AttributeError: raise NotImplementedError( 'This function requires Xen hypervisor') # TODO: add stubdomain stats to actual VMs for vm in info: domid = vm['domid'] current[domid] = {} current[domid]['memory_kb'] = vm['mem_kb'] current[domid]['cpu_time'] = int(vm['cpu_time']) vcpus = max(vm['online_vcpus'], 1) if domid in previous: current[domid]['cpu_usage_raw'] = int( (current[domid]['cpu_time'] - previous[domid]['cpu_time']) / 1000 ** 3 * 100 / (current_time - previous_time)) if current[domid]['cpu_usage_raw'] < 0: # VM has been rebooted current[domid]['cpu_usage_raw'] = 0 else: current[domid]['cpu_usage_raw'] = 0 current[domid]['cpu_usage'] = \ int(current[domid]['cpu_usage_raw'] / vcpus) return current_time, current class VMCollection: """A collection of Qubes VMs VMCollection supports ``in`` operator. You may test for ``qid``, ``name`` and whole VM object's presence. Iterating over VMCollection will yield machine objects. """ def __init__(self, app): self.app = app self._dict = dict() def close(self): del self.app self._dict.clear() del self._dict def __repr__(self): return '<{} {!r}>'.format( self.__class__.__name__, list(sorted(self.keys()))) def items(self): """Iterate over ``(qid, vm)`` pairs""" for qid in self.qids(): yield (qid, self[qid]) def qids(self): """Iterate over all qids qids are sorted by numerical order. """ return iter(sorted(self._dict.keys())) keys = qids def names(self): """Iterate over all names names are sorted by lexical order. """ return iter(sorted(vm.name for vm in self._dict.values())) def vms(self): """Iterate over all machines vms are sorted by qid. """ return iter(sorted(self._dict.values())) __iter__ = vms values = vms def add(self, value, _enable_events=True): """Add VM to collection :param qubes.vm.BaseVM value: VM to add :param _enable_events: :raises TypeError: when value is of wrong type :raises ValueError: when there is already VM which has equal ``qid`` """ # this violates duck typing, but is needed # for VMProperty to function correctly if not isinstance(value, qubes.vm.BaseVM): raise TypeError('{} holds only BaseVM instances'.format( self.__class__.__name__)) if value.qid in self: raise ValueError('This collection already holds VM that has ' 'qid={!r} ({!r})'.format(value.qid, self[value.qid])) if value.name in self: raise ValueError('A VM named {!s} already exists' .format(value.name)) self._dict[value.qid] = value if _enable_events: value.events_enabled = True self.app.fire_event('domain-add', vm=value) return value def __getitem__(self, key): if isinstance(key, int): return self._dict[key] if isinstance(key, str): for vm in self: if vm.name == key: return vm raise KeyError(key) if isinstance(key, qubes.vm.BaseVM): key = key.uuid if isinstance(key, uuid.UUID): for vm in self: if vm.uuid == key: return vm raise KeyError(key) raise KeyError(key) def __delitem__(self, key): vm = self[key] if not vm.is_halted(): raise qubes.exc.QubesVMNotHaltedError(vm) self.app.fire_event('domain-pre-delete', pre_event=True, vm=vm) try: if vm.libvirt_domain: vm.libvirt_domain.undefine() # pylint: disable=protected-access vm._libvirt_domain = None except libvirt.libvirtError as e: if e.get_error_code() == libvirt.VIR_ERR_NO_DOMAIN: # already undefined pass del self._dict[vm.qid] self.app.fire_event('domain-delete', vm=vm) def __contains__(self, key): return any((key in (vm, vm.qid, vm.name)) for vm in self) def __len__(self): return len(self._dict) def get_vms_based_on(self, template): template = self[template] return set(vm for vm in self if hasattr(vm, 'template') and vm.template == template) def get_vms_connected_to(self, netvm): new_vms = {self[netvm]} dependent_vms = set() # Dependency resolving only makes sense on NetVM (or derivative) # if not self[netvm_qid].is_netvm(): # return set([]) while new_vms: cur_vm = new_vms.pop() for vm in cur_vm.connected_vms: if vm in dependent_vms: continue dependent_vms.add(vm) # if vm.is_netvm(): new_vms.add(vm) return dependent_vms # XXX with Qubes Admin Api this will probably lead to race condition # whole process of creating and adding should be synchronised def get_new_unused_qid(self): used_ids = set(self.qids()) for i in range(1, qubes.config.max_qid): if i not in used_ids: return i raise LookupError("Cannot find unused qid!") def get_new_unused_dispid(self): for _ in range(int(qubes.config.max_dispid ** 0.5)): dispid = random.SystemRandom().randrange(qubes.config.max_dispid) if not any(getattr(vm, 'dispid', None) == dispid for vm in self): return dispid raise LookupError(( 'https://xkcd.com/221/', 'http://dilbert.com/strip/2001-10-25')[ random.randint(0, 1)]) def _default_pool(app): """ Default storage pool. 1. If there is one named 'default', use it. 2. Check if root fs is on LVM thin - use that 3. Look for file(-reflink)-based pool pointing to /var/lib/qubes 4. Fail """ if 'default' in app.pools: return app.pools['default'] if 'DEFAULT_LVM_POOL' in os.environ: thin_pool = os.environ['DEFAULT_LVM_POOL'] for pool in app.pools.values(): if pool.config.get('driver', None) != 'lvm_thin': continue if pool.config['thin_pool'] == thin_pool: return pool # no DEFAULT_LVM_POOL, or pool not defined root_volume_group, root_thin_pool = \ qubes.storage.DirectoryThinPool.thin_pool('/') if root_thin_pool: for pool in app.pools.values(): if pool.config.get('driver', None) != 'lvm_thin': continue if (pool.config['volume_group'] == root_volume_group and pool.config['thin_pool'] == root_thin_pool): return pool # not a thin volume? look for file pools for pool in app.pools.values(): if pool.config.get('driver', None) not in ('file', 'file-reflink'): continue if pool.config['dir_path'] == qubes.config.qubes_base_dir: return pool raise AttributeError('Cannot determine default storage pool') def _setter_pool(app, prop, value): if isinstance(value, qubes.storage.Pool): return value try: return app.pools[value] except KeyError: raise qubes.exc.QubesPropertyValueError(app, prop, value, 'No such storage pool') def _setter_default_netvm(app, prop, value): # skip netvm loop check while loading qubes.xml, to avoid tricky loading # order if not app.events_enabled: return value if value is None: return value # forbid setting to a value that would result in netvm loop for vm in app.domains: if not hasattr(vm, 'netvm'): continue if not vm.property_is_default('netvm'): continue if value == vm \ or value in app.domains.get_vms_connected_to(vm): raise qubes.exc.QubesPropertyValueError( app, prop, value, 'Network loop on \'{!s}\''.format(vm)) return value class Qubes(qubes.PropertyHolder): """Main Qubes application :param str store: path to ``qubes.xml`` The store is loaded in stages: 1. In the first stage there are loaded some basic features from store (currently labels). 2. In the second stage stubs for all VMs are loaded. They are filled with their basic properties, like ``qid`` and ``name``. 3. In the third stage all global properties are loaded. They often reference VMs, like default netvm, so they should be filled after loading VMs. 4. In the fourth stage all remaining VM properties are loaded. They also need all VMs loaded, because they represent dependencies between VMs like aforementioned netvm. 5. In the fifth stage there are some fixups to ensure sane system operation. This class emits following events: .. event:: domain-add (subject, event, vm) When domain is added. :param subject: Event emitter :param event: Event name (``'domain-add'``) :param vm: Domain object .. event:: domain-pre-delete (subject, event, vm) When domain is deleted. VM still has reference to ``app`` object, and is contained within VMCollection. You may prevent removal by raising an exception. :param subject: Event emitter :param event: Event name (``'domain-pre-delete'``) :param vm: Domain object .. event:: domain-delete (subject, event, vm) When domain is deleted. VM still has reference to ``app`` object, but is not contained within VMCollection. :param subject: Event emitter :param event: Event name (``'domain-delete'``) :param vm: Domain object .. event:: pool-add (subject, event, pool) When storage pool is added. Handler for this event can be asynchronous (a coroutine). :param subject: Event emitter :param event: Event name (``'pool-add'``) :param pool: Pool object .. event:: pool-pre-delete (subject, event, pool) When pool is deleted. Pool is still contained within app.pools dictionary. You may prevent removal by raising an exception. Handler for this event can be asynchronous (a coroutine). :param subject: Event emitter :param event: Event name (``'pool-pre-delete'``) :param pool: Pool object .. event:: pool-delete (subject, event, pool) When storage pool is deleted. The pool is already removed at this point. Handler for this event can be asynchronous (a coroutine). :param subject: Event emitter :param event: Event name (``'pool-delete'``) :param pool: Pool object Methods and attributes: """ default_netvm = qubes.VMProperty('default_netvm', load_stage=3, default=None, allow_none=True, setter=_setter_default_netvm, doc="""Default NetVM for AppVMs. Initial state is `None`, which means that AppVMs are not connected to the Internet.""") default_template = qubes.VMProperty('default_template', load_stage=3, vmclass=qubes.vm.templatevm.TemplateVM, doc='Default template for new AppVMs', allow_none=True) updatevm = qubes.VMProperty('updatevm', load_stage=3, default=None, allow_none=True, doc="""Which VM to use as `yum` proxy for updating AdminVM and TemplateVMs""") clockvm = qubes.VMProperty('clockvm', load_stage=3, default=None, allow_none=True, doc='Which VM to use as NTP proxy for updating ' 'AdminVM') default_kernel = qubes.property('default_kernel', load_stage=3, doc='Which kernel to use when not ' 'overriden in VM') default_dispvm = qubes.VMProperty('default_dispvm', load_stage=3, default=None, doc='Default DispVM base for service ' 'calls', allow_none=True) management_dispvm = qubes.VMProperty('management_dispvm', load_stage=3, default=None, doc='Default DispVM base for ' 'managing VMs', allow_none=True) default_pool = qubes.property('default_pool', load_stage=3, default=_default_pool, setter=_setter_pool, doc='Default storage pool') default_pool_private = qubes.property('default_pool_private', load_stage=3, default=lambda app: app.default_pool, setter=_setter_pool, doc='Default storage pool for ' 'private volumes') default_pool_root = qubes.property('default_pool_root', load_stage=3, default=lambda app: app.default_pool, setter=_setter_pool, doc='Default storage pool for root ' 'volumes') default_pool_volatile = qubes.property('default_pool_volatile', load_stage=3, default=lambda app: app.default_pool, setter=_setter_pool, doc='Default storage pool for ' 'volatile volumes') default_pool_kernel = qubes.property('default_pool_kernel', load_stage=3, default=lambda app: app.default_pool, setter=_setter_pool, doc='Default storage pool for kernel ' 'volumes') default_qrexec_timeout = qubes.property('default_qrexec_timeout', load_stage=3, default=60, type=int, doc="""Default time in seconds after which qrexec connection attempt is deemed failed""") default_shutdown_timeout = qubes.property('default_shutdown_timeout', load_stage=3, default=60, type=int, doc="""Default time in seconds for VM shutdown to complete""") stats_interval = qubes.property('stats_interval', load_stage=3, default=3, type=int, doc='Interval in seconds for VM stats ' 'reporting (memory, CPU usage)') # TODO #1637 #892 check_updates_vm = qubes.property('check_updates_vm', type=bool, setter=qubes.property.bool, load_stage=3, default=True, doc='check for updates inside qubes') def __init__(self, store=None, load=True, offline_mode=None, lock=False, **kwargs): #: logger instance for logging global messages self.log = logging.getLogger('app') self.log.debug('init() -> %#x', id(self)) self.log.debug('stack:') for frame in traceback.extract_stack(): self.log.debug('%s', frame) self._extensions = qubes.ext.get_extensions() #: collection of all VMs managed by this Qubes instance self.domains = VMCollection(self) #: collection of all available labels for VMs self.labels = {} #: collection of all pools self.pools = {} #: Connection to VMM self.vmm = VMMConnection( offline_mode=offline_mode, libvirt_reconnect_cb=self.register_event_handlers) #: Information about host system self.host = QubesHost(self) if store is not None: self._store = store else: self._store = os.environ.get('QUBES_XML_PATH', os.path.join( qubes.config.qubes_base_dir, qubes.config.system_path[ 'qubes_store_filename'])) super(Qubes, self).__init__(xml=None, **kwargs) self.__load_timestamp = None self.__locked_fh = None self._domain_event_callback_id = None #: jinja2 environment for libvirt XML templates self.env = jinja2.Environment( loader=jinja2.FileSystemLoader([ '/etc/qubes/templates', '/usr/share/qubes/templates', ]), undefined=jinja2.StrictUndefined) if load: self.load(lock=lock) self.events_enabled = True @property def store(self): return self._store def _migrate_global_properties(self): """Migrate renamed/dropped properties""" if self.xml is None: return # drop default_fw_netvm node_default_fw_netvm = self.xml.find( './properties/property[@name=\'default_fw_netvm\']') if node_default_fw_netvm is not None: node_default_netvm = self.xml.find( './properties/property[@name=\'default_netvm\']') try: default_fw_netvm = self.domains[node_default_fw_netvm.text] if node_default_netvm is None: default_netvm = None else: default_netvm = self.domains[node_default_netvm.text] if default_netvm != default_fw_netvm: for vm in self.domains: if not hasattr(vm, 'netvm'): continue if not getattr(vm, 'provides_network', False): continue node_netvm = vm.xml.find( './properties/property[@name=\'netvm\']') if node_netvm is not None: # non-default netvm continue # this will unfortunately break "being default" # property state, but the alternative (changing # value behind user's back) is worse properties = vm.xml.find('./properties') element = lxml.etree.Element('property', name='netvm') element.text = default_fw_netvm.name # manipulate xml directly, before loading netvm # property, to avoid hitting netvm loop detection properties.append(element) except KeyError: # if default_fw_netvm was set to invalid value, simply # drop it pass node_default_fw_netvm.getparent().remove(node_default_fw_netvm) def load(self, lock=False): """Open qubes.xml :throws EnvironmentError: failure on parsing store :throws xml.parsers.expat.ExpatError: failure on parsing store :raises lxml.etree.XMLSyntaxError: on syntax error in qubes.xml """ fh = self._acquire_lock() self.xml = lxml.etree.parse(fh) # stage 1: load labels and pools for node in self.xml.xpath('./labels/label'): label = qubes.Label.fromxml(node) self.labels[label.index] = label for node in self.xml.xpath('./pools/pool'): name = node.get('name') assert name, "Pool name '%s' is invalid " % name try: self.pools[name] = self._get_pool(**node.attrib) except qubes.exc.QubesException as e: self.log.error(str(e)) # stage 2: load VMs for node in self.xml.xpath('./domains/domain'): # pylint: disable=no-member cls = self.get_vm_class(node.get('class')) vm = cls(self, node) vm.load_properties(load_stage=2) vm.init_log() self.domains.add(vm, _enable_events=False) if 0 not in self.domains: self.domains.add( qubes.vm.adminvm.AdminVM(self, None), _enable_events=False) self._migrate_global_properties() # stage 3: load global properties self.load_properties(load_stage=3) # stage 4: fill all remaining VM properties for vm in self.domains: vm.load_properties(load_stage=4) vm.load_extras() # stage 5: misc fixups self.property_require('default_netvm', allow_none=True) self.property_require('default_template', allow_none=True) self.property_require('clockvm', allow_none=True) self.property_require('updatevm', allow_none=True) for vm in self.domains: vm.events_enabled = True vm.fire_event('domain-load') # get a file timestamp (before closing it - still holding the lock!), # to detect whether anyone else have modified it in the meantime self.__load_timestamp = os.path.getmtime(self._store) if not lock: self._release_lock() def __xml__(self): element = lxml.etree.Element('qubes') element.append(self.xml_labels()) pools_xml = lxml.etree.Element('pools') for pool in self.pools.values(): xml = pool.__xml__() if xml is not None: pools_xml.append(xml) element.append(pools_xml) element.append(self.xml_properties()) domains = lxml.etree.Element('domains') for vm in self.domains: domains.append(vm.__xml__()) element.append(domains) return element def __str__(self): return type(self).__name__ def save(self, lock=True): """Save all data to qubes.xml There are several problems with saving :file:`qubes.xml` which must be mitigated: - Running out of disk space. No space left should not result in empty file. This is done by writing to temporary file and then renaming. - Attempts to write two or more files concurrently. This is done by sophisticated locking. :param bool lock: keep file locked after saving :throws EnvironmentError: failure on saving """ if not self.__locked_fh: self._acquire_lock(for_save=True) fh_new = tempfile.NamedTemporaryFile( prefix=self._store, delete=False) lxml.etree.ElementTree(self.__xml__()).write( fh_new, encoding='utf-8', pretty_print=True) fh_new.flush() try: os.chown(fh_new.name, -1, grp.getgrnam('qubes').gr_gid) os.chmod(fh_new.name, 0o660) except KeyError: # group 'qubes' not found # don't change mode if no 'qubes' group in the system pass os.rename(fh_new.name, self._store) # update stored mtime, in case of multiple save() calls without # loading qubes.xml again self.__load_timestamp = os.path.getmtime(self._store) # this releases lock for all other processes, # but they should instantly block on the new descriptor self.__locked_fh.close() self.__locked_fh = fh_new if not lock: self._release_lock() def close(self): """Deconstruct the object and break circular references After calling this the object is unusable, not even for saving.""" self.log.debug('close() <- %#x', id(self)) for frame in traceback.extract_stack(): self.log.debug('%s', frame) super().close() if self._domain_event_callback_id is not None: self.vmm.libvirt_conn.domainEventDeregisterAny( self._domain_event_callback_id) self._domain_event_callback_id = None # Only our Lord, The God Almighty, knows what references # are kept in extensions. del self._extensions for vm in self.domains: vm.close() self.domains.close() del self.domains self.vmm.close() del self.vmm del self.host if self.__locked_fh: self._release_lock() def _acquire_lock(self, for_save=False): assert self.__locked_fh is None, 'double lock' while True: try: fd = os.open(self._store, os.O_RDWR | (os.O_CREAT * int(for_save))) except FileNotFoundError: if not for_save: raise qubes.exc.QubesException( 'Qubes XML store {!r} is missing; ' 'use qubes-create tool'.format(self._store)) raise # While we were waiting for lock, someone could have unlink()ed # (or rename()d) our file out of the filesystem. We have to # ensure we got lock on something linked to filesystem. # If not, try again. if os.fstat(fd) != os.stat(self._store): os.close(fd) continue if self.__load_timestamp and \ os.path.getmtime(self._store) != self.__load_timestamp: os.close(fd) raise qubes.exc.QubesException( 'Someone else modified qubes.xml in the meantime') break if os.name == 'posix': fcntl.lockf(fd, fcntl.LOCK_EX) elif os.name == 'nt': # pylint: disable=protected-access overlapped = pywintypes.OVERLAPPED() win32file.LockFileEx( win32file._get_osfhandle(fd), win32con.LOCKFILE_EXCLUSIVE_LOCK, 0, -0x10000, overlapped) self.__locked_fh = os.fdopen(fd, 'r+b') return self.__locked_fh def _release_lock(self): assert self.__locked_fh is not None, 'double release' # intentionally do not call explicit unlock to not unlock the file # before all buffers are flushed self.__locked_fh.close() self.__locked_fh = None def load_initial_values(self): self.labels = { 1: qubes.Label(1, '0xcc0000', 'red'), 2: qubes.Label(2, '0xf57900', 'orange'), 3: qubes.Label(3, '0xedd400', 'yellow'), 4: qubes.Label(4, '0x73d216', 'green'), 5: qubes.Label(5, '0x555753', 'gray'), 6: qubes.Label(6, '0x3465a4', 'blue'), 7: qubes.Label(7, '0x75507b', 'purple'), 8: qubes.Label(8, '0x000000', 'black'), } assert max(self.labels.keys()) == qubes.config.max_default_label pool_configs = copy.deepcopy(qubes.config.defaults['pool_configs']) root_volume_group, root_thin_pool = \ qubes.storage.DirectoryThinPool.thin_pool('/') if root_thin_pool: lvm_config = { 'name': 'lvm', 'driver': 'lvm_thin', 'volume_group': root_volume_group, 'thin_pool': root_thin_pool } pool_configs[lvm_config['name']] = lvm_config for name, config in pool_configs.items(): if 'driver' not in config and 'dir_path' in config: config['driver'] = 'file' try: os.makedirs(config['dir_path'], exist_ok=True) if qubes.storage.reflink.is_supported(config['dir_path']): config['driver'] = 'file-reflink' config['setup_check'] = 'no' # don't check twice except PermissionError: # looks like a testing environment pass # stay with 'file' self.pools[name] = self._get_pool(**config) self.default_pool_kernel = 'linux-kernel' self.domains.add( qubes.vm.adminvm.AdminVM(self, None, label='black')) @classmethod def create_empty_store(cls, *args, **kwargs): self = cls(*args, load=False, **kwargs) if os.path.exists(self.store): raise qubes.exc.QubesException( '{} already exists, aborting'.format(self.store)) self.load_initial_values() # TODO py3 get lock= as keyword-only arg self.save(kwargs.get('lock')) return self def xml_labels(self): """Serialise labels :rtype: lxml.etree._Element """ labels = lxml.etree.Element('labels') for label in sorted(self.labels.values(), key=lambda labl: labl.index): labels.append(label.__xml__()) return labels @staticmethod def get_vm_class(clsname): """Find the class for a domain. Classes are registered as setuptools' entry points in ``qubes.vm`` group. Any package may supply their own classes. :param str clsname: name of the class :return type: class """ try: return qubes.utils.get_entry_point_one( qubes.vm.VM_ENTRY_POINT, clsname) except KeyError: raise qubes.exc.QubesException( 'no such VM class: {!r}'.format(clsname)) # don't catch TypeError def add_new_vm(self, cls, qid=None, **kwargs): """Add new Virtual Machine to collection """ if qid is None: qid = self.domains.get_new_unused_qid() if isinstance(cls, str): cls = self.get_vm_class(cls) # handle default template; specifically allow template=None (do not # override it with default template) if 'template' not in kwargs and hasattr(cls, 'template'): if cls == self.get_vm_class('DispVM'): kwargs['template'] = self.default_dispvm else: kwargs['template'] = self.default_template if kwargs['template'] is None: raise qubes.exc.QubesValueError( 'Template for the qube not specified, nor default ' 'template set.') elif 'template' in kwargs and isinstance(kwargs['template'], str): kwargs['template'] = self.domains[kwargs['template']] return self.domains.add(cls(self, None, qid=qid, **kwargs)) def get_label(self, label): """Get label as identified by index or name :throws KeyError: when label is not found """ # first search for index, verbatim try: return self.labels[label] except KeyError: pass # then search for name for i in self.labels.values(): if i.name == label: return i # last call, if label is a number represented as str, search in indices try: return self.labels[int(label)] except (KeyError, ValueError): pass raise KeyError(label) @asyncio.coroutine def setup_pools(self): """ Run implementation specific setup for each storage pool. """ yield from qubes.utils.void_coros_maybe( pool.setup() for pool in self.pools.values()) @asyncio.coroutine def add_pool(self, name, **kwargs): """ Add a storage pool to config.""" if name in self.pools.keys(): raise qubes.exc.QubesException('pool named %s already exists \n' % name) kwargs['name'] = name pool = self._get_pool(**kwargs) yield from qubes.utils.coro_maybe(pool.setup()) self.pools[name] = pool yield from self.fire_event_async('pool-add', pool=pool) return pool @asyncio.coroutine def remove_pool(self, name): """ Remove a storage pool from config file. """ try: pool = self.pools[name] volumes = [(vm, volume) for vm in self.domains for volume in vm.volumes.values() if volume.pool is pool] if volumes: raise qubes.exc.QubesPoolInUseError(pool) prop_suffixes = ['', '_kernel', '_private', '_root', '_volatile'] for suffix in prop_suffixes: if getattr(self, 'default_pool' + suffix, None) is pool: raise qubes.exc.QubesPoolInUseError( pool, 'Storage pool is in use: ' 'set as {}'.format('default_pool' + suffix)) yield from self.fire_event_async('pool-pre-delete', pre_event=True, pool=pool) del self.pools[name] yield from qubes.utils.coro_maybe(pool.destroy()) yield from self.fire_event_async('pool-delete', pool=pool) except KeyError: return def get_pool(self, pool): """ Returns a :py:class:`qubes.storage.Pool` instance """ if isinstance(pool, qubes.storage.Pool): return pool try: return self.pools[pool] except KeyError: raise qubes.exc.QubesException('Unknown storage pool ' + pool) @staticmethod def _get_pool(**kwargs): try: name = kwargs['name'] assert name, 'Name needs to be an non empty string' except KeyError: raise qubes.exc.QubesException('No pool name for pool') try: driver = kwargs['driver'] except KeyError: raise qubes.exc.QubesException('No driver specified for pool ' + name) try: klass = qubes.utils.get_entry_point_one( qubes.storage.STORAGE_ENTRY_POINT, driver) del kwargs['driver'] return klass(**kwargs) except KeyError: raise qubes.exc.QubesException('No driver %s for pool %s' % (driver, name)) def register_event_handlers(self, old_connection=None): """Register libvirt event handlers, which will translate libvirt events into qubes.events. This function should be called only in 'qubesd' process and only when mainloop has been already set. """ if old_connection: try: old_connection.domainEventDeregisterAny( self._domain_event_callback_id) except libvirt.libvirtError: # the connection is probably in a bad state; but call the above # anyway to cleanup the client structures pass self._domain_event_callback_id = ( self.vmm.libvirt_conn.domainEventRegisterAny( None, # any domain libvirt.VIR_DOMAIN_EVENT_ID_LIFECYCLE, self._domain_event_callback, None)) def _domain_event_callback(self, _conn, domain, event, _detail, _opaque): """Generic libvirt event handler (virConnectDomainEventCallback), translate libvirt event into qubes.events. """ if not self.events_enabled: return try: vm = self.domains[domain.name()] except KeyError: # ignore events for unknown domains return if event == libvirt.VIR_DOMAIN_EVENT_STOPPED: vm.on_libvirt_domain_stopped() elif event == libvirt.VIR_DOMAIN_EVENT_SUSPENDED: try: vm.fire_event('domain-paused') except Exception: # pylint: disable=broad-except self.log.exception( 'Uncaught exception from domain-paused handler ' 'for domain %s', vm.name) elif event == libvirt.VIR_DOMAIN_EVENT_RESUMED: try: vm.fire_event('domain-unpaused') except Exception: # pylint: disable=broad-except self.log.exception( 'Uncaught exception from domain-unpaused handler ' 'for domain %s', vm.name) @qubes.events.handler('domain-pre-delete') def on_domain_pre_deleted(self, event, vm): # pylint: disable=unused-argument for obj in itertools.chain(self.domains, (self,)): if obj is vm: # allow removed VM to reference itself continue for prop in obj.property_list(): try: if isinstance(prop, qubes.vm.VMProperty) and \ getattr(obj, prop.__name__) == vm: self.log.error( 'Cannot remove %s, used by %s.%s', vm, obj, prop.__name__) raise qubes.exc.QubesVMInUseError( vm, 'Domain is in use: {!r};' 'see /var/log/qubes/qubes.log in dom0 for ' 'details'.format( vm.name)) except AttributeError: pass @qubes.events.handler('domain-delete') def on_domain_deleted(self, event, vm): # pylint: disable=unused-argument for propname in ( 'default_netvm', 'default_fw_netvm', 'clockvm', 'updatevm', 'default_template', ): try: if getattr(self, propname) == vm: delattr(self, propname) except AttributeError: pass @qubes.events.handler('property-pre-set:clockvm') def on_property_pre_set_clockvm(self, event, name, newvalue, oldvalue=None): # pylint: disable=unused-argument,no-self-use if newvalue is None: return if 'service.clocksync' not in newvalue.features: newvalue.features['service.clocksync'] = True @qubes.events.handler('property-set:clockvm') def on_property_set_clockvm(self, event, name, newvalue, oldvalue=None): # pylint: disable=unused-argument,no-self-use if oldvalue and oldvalue.features.get('service.clocksync', False): del oldvalue.features['service.clocksync'] @qubes.events.handler('property-pre-set:default_netvm') def on_property_pre_set_default_netvm(self, event, name, newvalue, oldvalue=None): # pylint: disable=unused-argument,invalid-name if newvalue is not None and oldvalue is not None \ and oldvalue.is_running() and not newvalue.is_running() \ and self.domains.get_vms_connected_to(oldvalue): raise qubes.exc.QubesVMNotRunningError( newvalue, 'Cannot change {!r} to domain that ' 'is not running ({!r}).'.format( name, newvalue.name)) @qubes.events.handler('property-set:default_fw_netvm') def on_property_set_default_fw_netvm(self, event, name, newvalue, oldvalue=None): # pylint: disable=unused-argument,invalid-name for vm in self.domains: if hasattr(vm, 'provides_network') and vm.provides_network and \ hasattr(vm, 'netvm') and vm.property_is_default('netvm'): # fire property-del:netvm as it is responsible for resetting # netvm to it's default value vm.fire_event('property-pre-del:netvm', pre_event=True, name='netvm', oldvalue=oldvalue) vm.fire_event('property-del:netvm', name='netvm', oldvalue=oldvalue) @qubes.events.handler('property-set:default_netvm') def on_property_set_default_netvm(self, event, name, newvalue, oldvalue=None): # pylint: disable=unused-argument for vm in self.domains: if hasattr(vm, 'provides_network') and not vm.provides_network and \ hasattr(vm, 'netvm') and vm.property_is_default('netvm'): # fire property-del:netvm as it is responsible for resetting # netvm to it's default value vm.fire_event('property-pre-del:netvm', pre_event=True, name='netvm', oldvalue=oldvalue) vm.fire_event('property-del:netvm', name='netvm', oldvalue=oldvalue)