__init__.py 33 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976
  1. #
  2. # The Qubes OS Project, https://www.qubes-os.org/
  3. #
  4. # Copyright (C) 2013-2015 Joanna Rutkowska <joanna@invisiblethingslab.com>
  5. # Copyright (C) 2013-2015 Marek Marczykowski-Górecki
  6. # <marmarek@invisiblethingslab.com>
  7. # Copyright (C) 2015 Wojtek Porczyk <woju@invisiblethingslab.com>
  8. #
  9. # This library is free software; you can redistribute it and/or
  10. # modify it under the terms of the GNU Lesser General Public
  11. # License as published by the Free Software Foundation; either
  12. # version 2.1 of the License, or (at your option) any later version.
  13. #
  14. # This library is distributed in the hope that it will be useful,
  15. # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17. # Lesser General Public License for more details.
  18. #
  19. # You should have received a copy of the GNU Lesser General Public
  20. # License along with this library; if not, see <https://www.gnu.org/licenses/>.
  21. #
  22. """ Qubes storage system"""
  23. from __future__ import absolute_import
  24. import inspect
  25. import os
  26. import os.path
  27. import string # pylint: disable=deprecated-module
  28. import subprocess
  29. import time
  30. from datetime import datetime
  31. import asyncio
  32. import lxml.etree
  33. import pkg_resources
  34. import qubes
  35. import qubes.exc
  36. import qubes.utils
  37. STORAGE_ENTRY_POINT = 'qubes.storage'
  38. class StoragePoolException(qubes.exc.QubesException):
  39. ''' A general storage exception '''
  40. class BlockDevice:
  41. ''' Represents a storage block device. '''
  42. # pylint: disable=too-few-public-methods
  43. def __init__(self, path, name, script=None, rw=True, domain=None,
  44. devtype='disk'):
  45. assert name, 'Missing device name'
  46. assert path, 'Missing device path'
  47. self.path = path
  48. self.name = name
  49. self.rw = rw
  50. self.script = script
  51. self.domain = domain
  52. self.devtype = devtype
  53. class Volume:
  54. ''' Encapsulates all data about a volume for serialization to qubes.xml and
  55. libvirt config.
  56. Keep in mind!
  57. volatile = not snap_on_start and not save_on_stop
  58. snapshot = snap_on_start and not save_on_stop
  59. origin = not snap_on_start and save_on_stop
  60. origin_snapshot = snap_on_start and save_on_stop
  61. '''
  62. devtype = 'disk'
  63. domain = None
  64. path = None
  65. script = None
  66. #: disk space used by this volume, can be smaller than :py:attr:`size`
  67. #: for sparse volumes
  68. usage = 0
  69. def __init__(self, name, pool, vid,
  70. revisions_to_keep=0, rw=False, save_on_stop=False, size=0,
  71. snap_on_start=False, source=None, **kwargs):
  72. ''' Initialize a volume.
  73. :param str name: The name of the volume inside owning domain
  74. :param Pool pool: The pool object
  75. :param str vid: Volume identifier needs to be unique in pool
  76. :param int revisions_to_keep: Amount of revisions to keep around
  77. :param bool rw: If true volume will be mounted read-write
  78. :param bool snap_on_start: Create a snapshot from source on
  79. start, instead of using volume own data
  80. :param bool save_on_stop: Write changes to the volume in
  81. vm.stop(), otherwise - discard
  82. :param Volume source: other volume in same pool to make snapshot
  83. from, required if *snap_on_start*=`True`
  84. :param str/int size: Size of the volume
  85. '''
  86. super(Volume, self).__init__(**kwargs)
  87. assert isinstance(pool, Pool)
  88. assert source is None or (isinstance(source, Volume)
  89. and source.pool == pool)
  90. if snap_on_start and source is None:
  91. msg = "snap_on_start specified on {!r} but no volume source set"
  92. msg = msg.format(name)
  93. raise StoragePoolException(msg)
  94. if not snap_on_start and source is not None:
  95. msg = "source specified on {!r} but no snap_on_start set"
  96. msg = msg.format(name)
  97. raise StoragePoolException(msg)
  98. #: Name of the volume in a domain it's attached to (like `root` or
  99. #: `private`).
  100. self.name = str(name)
  101. #: :py:class:`Pool` instance owning this volume
  102. self.pool = pool
  103. #: How many revisions of the volume to keep. Each revision is created
  104. # at :py:meth:`stop`, if :py:attr:`save_on_stop` is True
  105. self.revisions_to_keep = int(revisions_to_keep)
  106. #: Should this volume be writable by domain.
  107. self.rw = rw
  108. #: Should volume state be saved or discarded at :py:meth:`stop`
  109. self.save_on_stop = save_on_stop
  110. self._size = int(size)
  111. #: Should the volume state be initialized with a snapshot of
  112. #: same-named volume of domain's template.
  113. self.snap_on_start = snap_on_start
  114. #: source volume for :py:attr:`snap_on_start` volumes
  115. self.source = source
  116. #: Volume unique (inside given pool) identifier
  117. self.vid = vid
  118. def __eq__(self, other):
  119. if isinstance(other, Volume):
  120. return other.pool == self.pool and other.vid == self.vid
  121. return NotImplemented
  122. def __hash__(self):
  123. return hash('%s:%s' % (self.pool, self.vid))
  124. def __neq__(self, other):
  125. return not self.__eq__(other)
  126. def __repr__(self):
  127. return '{!r}'.format(str(self.pool) + ':' + self.vid)
  128. def __str__(self):
  129. return str(self.vid)
  130. def __xml__(self):
  131. config = _sanitize_config(self.config)
  132. return lxml.etree.Element('volume', **config)
  133. def create(self):
  134. ''' Create the given volume on disk.
  135. This method is called only once in the volume lifetime. Before
  136. calling this method, no data on disk should be touched (in
  137. context of this volume).
  138. This can be implemented as a coroutine.
  139. '''
  140. raise self._not_implemented("create")
  141. def remove(self):
  142. ''' Remove volume.
  143. This can be implemented as a coroutine.'''
  144. raise self._not_implemented("remove")
  145. def export(self):
  146. ''' Returns a path to read the volume data from.
  147. Reading from this path when domain owning this volume is
  148. running (i.e. when :py:meth:`is_dirty` is True) should return the
  149. data from before domain startup.
  150. Reading from the path returned by this method should return the
  151. volume data. If extracting volume data require something more
  152. than just reading from file (for example connecting to some other
  153. domain, or decompressing the data), the returned path may be a pipe.
  154. '''
  155. raise self._not_implemented("export")
  156. def import_data(self):
  157. ''' Returns a path to overwrite volume data.
  158. This method is called after volume was already :py:meth:`create`-ed.
  159. Writing to this path should overwrite volume data. If importing
  160. volume data require something more than just writing to a file (
  161. for example connecting to some other domain, or converting data
  162. on the fly), the returned path may be a pipe.
  163. This can be implemented as a coroutine.
  164. '''
  165. raise self._not_implemented("import_data")
  166. def import_data_end(self, success):
  167. ''' End the data import operation. This may be used by pool
  168. implementation to commit changes, cleanup temporary files etc.
  169. This method is called regardless the operation was successful or not.
  170. This can be implemented as a coroutine.
  171. :param success: True if data import was successful, otherwise False
  172. '''
  173. # by default do nothing
  174. def import_volume(self, src_volume):
  175. ''' Imports data from a different volume (possibly in a different
  176. pool.
  177. The volume needs to be create()d first.
  178. This can be implemented as a coroutine. '''
  179. # pylint: disable=unused-argument
  180. raise self._not_implemented("import_volume")
  181. def is_dirty(self):
  182. ''' Return `True` if volume was not properly shutdown and committed.
  183. This include the situation when domain owning the volume is still
  184. running.
  185. '''
  186. raise self._not_implemented("is_dirty")
  187. def is_outdated(self):
  188. ''' Returns `True` if this snapshot of a source volume (for
  189. `snap_on_start`=True) is outdated.
  190. '''
  191. raise self._not_implemented("is_outdated")
  192. def resize(self, size):
  193. ''' Expands volume, throws
  194. :py:class:`qubes.storage.StoragePoolException` if
  195. given size is less than current_size
  196. This can be implemented as a coroutine.
  197. :param int size: new size in bytes
  198. '''
  199. # pylint: disable=unused-argument
  200. raise self._not_implemented("resize")
  201. def revert(self, revision=None):
  202. ''' Revert volume to previous revision
  203. This can be implemented as a coroutine.
  204. :param revision: revision to revert volume to, see :py:attr:`revisions`
  205. '''
  206. # pylint: disable=unused-argument
  207. raise self._not_implemented("revert")
  208. def start(self):
  209. ''' Do what ever is needed on start.
  210. This include making a snapshot of template's volume if
  211. :py:attr:`snap_on_start` is set.
  212. This can be implemented as a coroutine.'''
  213. raise self._not_implemented("start")
  214. def stop(self):
  215. ''' Do what ever is needed on stop.
  216. This include committing data if :py:attr:`save_on_stop` is set.
  217. This can be implemented as a coroutine.'''
  218. raise self._not_implemented("stop")
  219. def verify(self):
  220. ''' Verifies the volume.
  221. This function is supposed to either return :py:obj:`True`, or raise
  222. an exception.
  223. This can be implemented as a coroutine.'''
  224. raise self._not_implemented("verify")
  225. def block_device(self):
  226. ''' Return :py:class:`BlockDevice` for serialization in
  227. the libvirt XML template as <disk>.
  228. '''
  229. return BlockDevice(self.path, self.name, self.script,
  230. self.rw, self.domain, self.devtype)
  231. @property
  232. def revisions(self):
  233. ''' Returns a dict containing revision identifiers and time of their
  234. creation '''
  235. msg = "{!s} has revisions not implemented".format(self.__class__)
  236. raise NotImplementedError(msg)
  237. @property
  238. def size(self):
  239. ''' Volume size in bytes '''
  240. return self._size
  241. @size.setter
  242. def size(self, size):
  243. # pylint: disable=attribute-defined-outside-init
  244. self._size = int(size)
  245. @property
  246. def config(self):
  247. ''' return config data for serialization to qubes.xml '''
  248. result = {
  249. 'name': self.name,
  250. 'pool': str(self.pool),
  251. 'vid': self.vid,
  252. 'revisions_to_keep': self.revisions_to_keep,
  253. 'rw': self.rw,
  254. 'save_on_stop': self.save_on_stop,
  255. 'snap_on_start': self.snap_on_start,
  256. }
  257. if self.size:
  258. result['size'] = self.size
  259. if self.source:
  260. result['source'] = str(self.source)
  261. return result
  262. def _not_implemented(self, method_name):
  263. ''' Helper for emitting helpful `NotImplementedError` exceptions '''
  264. msg = "Volume {!s} has {!s}() not implemented"
  265. msg = msg.format(str(self.__class__.__name__), method_name)
  266. return NotImplementedError(msg)
  267. class Storage:
  268. ''' Class for handling VM virtual disks.
  269. This is base class for all other implementations, mostly with Xen on Linux
  270. in mind.
  271. '''
  272. AVAILABLE_FRONTENDS = {'xvd' + c for c in string.ascii_lowercase}
  273. def __init__(self, vm):
  274. #: Domain for which we manage storage
  275. self.vm = vm
  276. self.log = self.vm.log
  277. #: Additional drive (currently used only by HVM)
  278. self.drive = None
  279. if hasattr(vm, 'volume_config'):
  280. for name, conf in self.vm.volume_config.items():
  281. self.init_volume(name, conf)
  282. def _update_volume_config_source(self, name, volume_config):
  283. '''Retrieve 'source' volume from VM's template'''
  284. template = getattr(self.vm, 'template', None)
  285. # recursively lookup source volume - templates may be
  286. # chained (TemplateVM -> AppVM -> DispVM, where the
  287. # actual source should be used from TemplateVM)
  288. while template:
  289. source = template.volumes[name]
  290. volume_config['source'] = source
  291. volume_config['pool'] = source.pool
  292. volume_config['size'] = source.size
  293. if source.source is not None:
  294. template = getattr(template, 'template', None)
  295. else:
  296. break
  297. def init_volume(self, name, volume_config):
  298. ''' Initialize Volume instance attached to this domain '''
  299. if 'name' not in volume_config:
  300. volume_config['name'] = name
  301. if 'source' in volume_config:
  302. # we have no control over VM load order,
  303. # so initialize storage recursively if needed
  304. template = getattr(self.vm, 'template', None)
  305. if template and template.storage is None:
  306. template.storage = Storage(template)
  307. if volume_config['source'] is None:
  308. self._update_volume_config_source(name, volume_config)
  309. else:
  310. # if source is already specified, pool needs to be too
  311. pool = self.vm.app.get_pool(volume_config['pool'])
  312. volume_config['source'] = pool.volumes[volume_config['source']]
  313. # if pool still unknown, load default
  314. if 'pool' not in volume_config:
  315. volume_config['pool'] = \
  316. getattr(self.vm.app, 'default_pool_' + name)
  317. pool = self.vm.app.get_pool(volume_config['pool'])
  318. if 'internal' in volume_config:
  319. # migrate old config
  320. del volume_config['internal']
  321. volume = pool.init_volume(self.vm, volume_config)
  322. self.vm.volumes[name] = volume
  323. return volume
  324. def attach(self, volume, rw=False):
  325. ''' Attach a volume to the domain '''
  326. assert self.vm.is_running()
  327. if self._is_already_attached(volume):
  328. self.vm.log.info("{!r} already attached".format(volume))
  329. return
  330. try:
  331. frontend = self.unused_frontend()
  332. except IndexError:
  333. raise StoragePoolException("No unused frontend found")
  334. disk = lxml.etree.Element("disk")
  335. disk.set('type', 'block')
  336. disk.set('device', 'disk')
  337. lxml.etree.SubElement(disk, 'driver').set('name', 'phy')
  338. lxml.etree.SubElement(disk, 'source').set('dev', '/dev/%s' % volume.vid)
  339. lxml.etree.SubElement(disk, 'target').set('dev', frontend)
  340. if not rw:
  341. lxml.etree.SubElement(disk, 'readonly')
  342. if volume.domain is not None:
  343. lxml.etree.SubElement(disk, 'backenddomain').set(
  344. 'name', volume.domain.name)
  345. xml_string = lxml.etree.tostring(disk, encoding='utf-8')
  346. self.vm.libvirt_domain.attachDevice(xml_string)
  347. # trigger watches to update device status
  348. # FIXME: this should be removed once libvirt will report such
  349. # events itself
  350. # self.vm.untrusted_qdb.write('/qubes-block-devices', '')
  351. # ← do we need this?
  352. def _is_already_attached(self, volume):
  353. ''' Checks if the given volume is already attached '''
  354. parsed_xml = lxml.etree.fromstring(self.vm.libvirt_domain.XMLDesc())
  355. disk_sources = parsed_xml.xpath("//domain/devices/disk/source")
  356. for source in disk_sources:
  357. if source.get('dev') == '/dev/%s' % volume.vid:
  358. return True
  359. return False
  360. def detach(self, volume):
  361. ''' Detach a volume from domain '''
  362. parsed_xml = lxml.etree.fromstring(self.vm.libvirt_domain.XMLDesc())
  363. disks = parsed_xml.xpath("//domain/devices/disk")
  364. for disk in disks:
  365. source = disk.xpath('source')[0]
  366. if source.get('dev') == '/dev/%s' % volume.vid:
  367. disk_xml = lxml.etree.tostring(disk, encoding='utf-8')
  368. self.vm.libvirt_domain.detachDevice(disk_xml)
  369. return
  370. raise StoragePoolException('Volume {!r} is not attached'.format(volume))
  371. @property
  372. def kernels_dir(self):
  373. '''Directory where kernel resides.
  374. If :py:attr:`self.vm.kernel` is :py:obj:`None`, the this points inside
  375. :py:attr:`self.vm.dir_path`
  376. '''
  377. if not self.vm.kernel:
  378. return None
  379. if 'kernel' in self.vm.volumes:
  380. return self.vm.volumes['kernel'].kernels_dir
  381. return os.path.join(
  382. qubes.config.qubes_base_dir,
  383. qubes.config.system_path['qubes_kernels_base_dir'],
  384. self.vm.kernel)
  385. def get_disk_utilization(self):
  386. ''' Returns summed up disk utilization for all domain volumes '''
  387. result = 0
  388. for volume in self.vm.volumes.values():
  389. result += volume.usage
  390. return result
  391. @asyncio.coroutine
  392. def resize(self, volume, size):
  393. ''' Resizes volume a read-writable volume '''
  394. if isinstance(volume, str):
  395. volume = self.vm.volumes[volume]
  396. ret = volume.resize(size)
  397. if asyncio.iscoroutine(ret):
  398. yield from ret
  399. if self.vm.is_running():
  400. try:
  401. yield from self.vm.run_service_for_stdio('qubes.ResizeDisk',
  402. input=volume.name.encode(),
  403. user='root')
  404. except subprocess.CalledProcessError as e:
  405. service_error = e.stderr.decode('ascii', errors='ignore')
  406. service_error = service_error.replace('%', '')
  407. raise StoragePoolException(
  408. 'Online resize of volume {} failed (you need to resize '
  409. 'filesystem manually): {}'.format(volume, service_error))
  410. @asyncio.coroutine
  411. def create(self):
  412. ''' Creates volumes on disk '''
  413. old_umask = os.umask(0o002)
  414. coros = []
  415. for volume in self.vm.volumes.values():
  416. # launch the operation, if it's asynchronous, then append to wait
  417. # for them at the end
  418. ret = volume.create()
  419. if asyncio.iscoroutine(ret):
  420. coros.append(ret)
  421. yield from _wait_and_reraise(coros)
  422. os.umask(old_umask)
  423. @asyncio.coroutine
  424. def clone_volume(self, src_vm, name):
  425. ''' Clone single volume from the specified vm
  426. :param QubesVM src_vm: source VM
  427. :param str name: name of volume to clone ('root', 'private' etc)
  428. :return cloned volume object
  429. '''
  430. config = self.vm.volume_config[name]
  431. dst_pool = self.vm.app.get_pool(config['pool'])
  432. dst = dst_pool.init_volume(self.vm, config)
  433. src_volume = src_vm.volumes[name]
  434. msg = "Importing volume {!s} from vm {!s}"
  435. self.vm.log.info(msg.format(src_volume.name, src_vm.name))
  436. # First create the destination volume
  437. create_op_ret = dst.create()
  438. # clone/import functions may be either synchronous or asynchronous
  439. # in the later case, we need to wait for them to finish
  440. if asyncio.iscoroutine(create_op_ret):
  441. yield from create_op_ret
  442. # Then import data from source volume
  443. clone_op_ret = dst.import_volume(src_volume)
  444. # clone/import functions may be either synchronous or asynchronous
  445. # in the later case, we need to wait for them to finish
  446. if asyncio.iscoroutine(clone_op_ret):
  447. yield from clone_op_ret
  448. self.vm.volumes[name] = dst
  449. return self.vm.volumes[name]
  450. @asyncio.coroutine
  451. def clone(self, src_vm):
  452. ''' Clone volumes from the specified vm '''
  453. self.vm.volumes = {}
  454. with VmCreationManager(self.vm):
  455. yield from _wait_and_reraise([self.clone_volume(src_vm, vol_name)
  456. for vol_name in self.vm.volume_config.keys()])
  457. @property
  458. def outdated_volumes(self):
  459. ''' Returns a list of outdated volumes '''
  460. result = []
  461. if self.vm.is_halted():
  462. return result
  463. volumes = self.vm.volumes
  464. for volume in volumes.values():
  465. if volume.is_outdated():
  466. result += [volume]
  467. return result
  468. @asyncio.coroutine
  469. def verify(self):
  470. '''Verify that the storage is sane.
  471. On success, returns normally. On failure, raises exception.
  472. '''
  473. if not os.path.exists(self.vm.dir_path):
  474. raise qubes.exc.QubesVMError(
  475. self.vm,
  476. 'VM directory does not exist: {}'.format(self.vm.dir_path))
  477. futures = []
  478. for volume in self.vm.volumes.values():
  479. ret = volume.verify()
  480. if asyncio.iscoroutine(ret):
  481. futures.append(ret)
  482. yield from _wait_and_reraise(futures)
  483. self.vm.fire_event('domain-verify-files')
  484. return True
  485. @asyncio.coroutine
  486. def remove(self):
  487. ''' Remove all the volumes.
  488. Errors on removal are catched and logged.
  489. '''
  490. futures = []
  491. for name, volume in self.vm.volumes.items():
  492. self.log.info('Removing volume %s: %s' % (name, volume.vid))
  493. try:
  494. ret = volume.remove()
  495. if asyncio.iscoroutine(ret):
  496. futures.append(ret)
  497. except (IOError, OSError) as e:
  498. self.vm.log.exception("Failed to remove volume %s", name, e)
  499. try:
  500. yield from _wait_and_reraise(futures)
  501. except (IOError, OSError) as e:
  502. self.vm.log.exception("Failed to remove some volume", e)
  503. @asyncio.coroutine
  504. def start(self):
  505. ''' Execute the start method on each volume '''
  506. futures = []
  507. for volume in self.vm.volumes.values():
  508. ret = volume.start()
  509. if asyncio.iscoroutine(ret):
  510. futures.append(ret)
  511. yield from _wait_and_reraise(futures)
  512. @asyncio.coroutine
  513. def stop(self):
  514. ''' Execute the stop method on each volume '''
  515. futures = []
  516. for volume in self.vm.volumes.values():
  517. ret = volume.stop()
  518. if asyncio.iscoroutine(ret):
  519. futures.append(ret)
  520. yield from _wait_and_reraise(futures)
  521. def unused_frontend(self):
  522. ''' Find an unused device name '''
  523. unused_frontends = self.AVAILABLE_FRONTENDS.difference(
  524. self.used_frontends)
  525. return sorted(unused_frontends)[0]
  526. @property
  527. def used_frontends(self):
  528. ''' Used device names '''
  529. xml = self.vm.libvirt_domain.XMLDesc()
  530. parsed_xml = lxml.etree.fromstring(xml)
  531. return {target.get('dev', None)
  532. for target in parsed_xml.xpath(
  533. "//domain/devices/disk/target")}
  534. def export(self, volume):
  535. ''' Helper function to export volume (pool.export(volume))'''
  536. assert isinstance(volume, (Volume, str)), \
  537. "You need to pass a Volume or pool name as str"
  538. if isinstance(volume, Volume):
  539. return volume.export()
  540. return self.vm.volumes[volume].export()
  541. @asyncio.coroutine
  542. def import_data(self, volume):
  543. ''' Helper function to import volume data (pool.import_data(volume))'''
  544. assert isinstance(volume, (Volume, str)), \
  545. "You need to pass a Volume or pool name as str"
  546. if isinstance(volume, Volume):
  547. ret = volume.import_data()
  548. else:
  549. ret = self.vm.volumes[volume].import_data()
  550. if asyncio.iscoroutine(ret):
  551. ret = yield from ret
  552. return ret
  553. @asyncio.coroutine
  554. def import_data_end(self, volume, success):
  555. ''' Helper function to finish/cleanup data import
  556. (pool.import_data_end( volume))'''
  557. assert isinstance(volume, (Volume, str)), \
  558. "You need to pass a Volume or pool name as str"
  559. if isinstance(volume, Volume):
  560. ret = volume.import_data_end(success=success)
  561. else:
  562. ret = self.vm.volumes[volume].import_data_end(success=success)
  563. if asyncio.iscoroutine(ret):
  564. ret = yield from ret
  565. return ret
  566. class VolumesCollection:
  567. '''Convenient collection wrapper for pool.get_volume and
  568. pool.list_volumes
  569. '''
  570. def __init__(self, pool):
  571. self._pool = pool
  572. def __getitem__(self, item):
  573. ''' Get a single volume with given Volume ID.
  574. You can also a Volume instance to get the same Volume or KeyError if
  575. Volume no longer exists.
  576. :param item: a Volume ID (str) or a Volume instance
  577. '''
  578. if isinstance(item, Volume):
  579. if item.pool == self._pool:
  580. return self[item.vid]
  581. raise KeyError(item)
  582. try:
  583. return self._pool.get_volume(item)
  584. except NotImplementedError:
  585. for vol in self:
  586. if vol.vid == item:
  587. return vol
  588. # if list_volumes is not implemented too, it will raise
  589. # NotImplementedError again earlier
  590. raise KeyError(item)
  591. def __iter__(self):
  592. ''' Get iterator over pool's volumes '''
  593. return iter(self._pool.list_volumes())
  594. def __contains__(self, item):
  595. ''' Check if given volume (either Volume ID or Volume instance) is
  596. present in the pool
  597. '''
  598. try:
  599. return self[item] is not None
  600. except KeyError:
  601. return False
  602. def keys(self):
  603. ''' Return list of volume IDs '''
  604. return [vol.vid for vol in self]
  605. def values(self):
  606. ''' Return list of Volumes'''
  607. return [vol for vol in self]
  608. class Pool:
  609. ''' A Pool is used to manage different kind of volumes (File
  610. based/LVM/Btrfs/...).
  611. 3rd Parties providing own storage implementations will need to extend
  612. this class.
  613. ''' # pylint: disable=unused-argument
  614. private_img_size = qubes.config.defaults['private_img_size']
  615. root_img_size = qubes.config.defaults['root_img_size']
  616. def __init__(self, name, revisions_to_keep=1, **kwargs):
  617. super(Pool, self).__init__(**kwargs)
  618. self._volumes_collection = VolumesCollection(self)
  619. self.name = name
  620. self.revisions_to_keep = revisions_to_keep
  621. kwargs['name'] = self.name
  622. def __eq__(self, other):
  623. if isinstance(other, Pool):
  624. return self.name == other.name
  625. if isinstance(other, str):
  626. return self.name == other
  627. return NotImplemented
  628. def __neq__(self, other):
  629. return not self.__eq__(other)
  630. def __str__(self):
  631. return self.name
  632. def __hash__(self):
  633. return hash(self.name)
  634. def __xml__(self):
  635. config = _sanitize_config(self.config)
  636. return lxml.etree.Element('pool', **config)
  637. @property
  638. def config(self):
  639. ''' Returns the pool config to be written to qubes.xml '''
  640. raise self._not_implemented("config")
  641. def destroy(self):
  642. ''' Called when removing the pool. Use this for implementation specific
  643. clean up.
  644. This can be implemented as a coroutine.
  645. '''
  646. raise self._not_implemented("destroy")
  647. def init_volume(self, vm, volume_config):
  648. ''' Initialize a :py:class:`qubes.storage.Volume` from `volume_config`.
  649. '''
  650. raise self._not_implemented("init_volume")
  651. def setup(self):
  652. ''' Called when adding a pool to the system. Use this for implementation
  653. specific set up.
  654. This can be implemented as a coroutine.
  655. '''
  656. raise self._not_implemented("setup")
  657. @property
  658. def volumes(self):
  659. ''' Return a collection of volumes managed by this pool '''
  660. return self._volumes_collection
  661. def list_volumes(self):
  662. ''' Return a list of volumes managed by this pool '''
  663. raise self._not_implemented("list_volumes")
  664. def get_volume(self, vid):
  665. ''' Return a volume with *vid* from this pool
  666. :raise KeyError: if no volume is found
  667. '''
  668. raise self._not_implemented("get_volume")
  669. def included_in(self, app):
  670. ''' Check if this pool is physically included in another one
  671. This works on best-effort basis, because one pool driver may not know
  672. all the other drivers.
  673. :param app: Qubes() object to lookup other pools in
  674. :returns pool or None
  675. '''
  676. @property
  677. def size(self):
  678. ''' Storage pool size in bytes, or None if unknown '''
  679. @property
  680. def usage(self):
  681. ''' Space used in the pool in bytes, or None if unknown '''
  682. def _not_implemented(self, method_name):
  683. ''' Helper for emitting helpful `NotImplementedError` exceptions '''
  684. msg = "Pool driver {!s} has {!s}() not implemented"
  685. msg = msg.format(str(self.__class__.__name__), method_name)
  686. return NotImplementedError(msg)
  687. @asyncio.coroutine
  688. def _wait_and_reraise(futures):
  689. if futures:
  690. done, _ = yield from asyncio.wait(futures)
  691. for task in done: # (re-)raise first exception in line
  692. task.result()
  693. def _sanitize_config(config):
  694. ''' Helper function to convert types to appropriate strings
  695. ''' # FIXME: find another solution for serializing basic types
  696. result = {}
  697. for key, value in config.items():
  698. if isinstance(value, bool):
  699. if value:
  700. result[key] = 'True'
  701. else:
  702. result[key] = str(value)
  703. return result
  704. def pool_drivers():
  705. """ Return a list of EntryPoints names """
  706. return [ep.name
  707. for ep in pkg_resources.iter_entry_points(STORAGE_ENTRY_POINT)]
  708. def driver_parameters(name):
  709. ''' Get __init__ parameters from a driver with out `self` & `name`. '''
  710. init_function = qubes.utils.get_entry_point_one(
  711. qubes.storage.STORAGE_ENTRY_POINT, name).__init__
  712. signature = inspect.signature(init_function)
  713. params = signature.parameters.keys()
  714. ignored_params = ['self', 'name', 'kwargs']
  715. return [p for p in params if p not in ignored_params]
  716. def isodate(seconds):
  717. ''' Helper method which returns an iso date '''
  718. return datetime.utcfromtimestamp(seconds).isoformat("T")
  719. def search_pool_containing_dir(pools, dir_path):
  720. ''' Helper function looking for a pool containing given directory.
  721. This is useful for implementing Pool.included_in method
  722. '''
  723. real_dir_path = os.path.realpath(dir_path)
  724. # prefer filesystem pools
  725. for pool in pools:
  726. if hasattr(pool, 'dir_path'):
  727. pool_real_dir_path = os.path.realpath(pool.dir_path)
  728. if os.path.commonpath([pool_real_dir_path, real_dir_path]) == \
  729. pool_real_dir_path:
  730. return pool
  731. # then look for lvm
  732. for pool in pools:
  733. if hasattr(pool, 'thin_pool') and hasattr(pool, 'volume_group'):
  734. if (pool.volume_group, pool.thin_pool) == \
  735. DirectoryThinPool.thin_pool(real_dir_path):
  736. return pool
  737. return None
  738. class VmCreationManager:
  739. ''' A `ContextManager` which cleans up if volume creation fails.
  740. ''' # pylint: disable=too-few-public-methods
  741. def __init__(self, vm):
  742. self.vm = vm
  743. def __enter__(self):
  744. pass
  745. def __exit__(self, type, value, tb): # pylint: disable=redefined-builtin
  746. if type is not None and value is not None and tb is not None:
  747. for volume in self.vm.volumes.values():
  748. try:
  749. volume.remove()
  750. except Exception: # pylint: disable=broad-except
  751. pass
  752. os.rmdir(self.vm.dir_path)
  753. # pylint: disable=too-few-public-methods
  754. class DirectoryThinPool:
  755. '''The thin pool containing the device of given filesystem'''
  756. _thin_pool = {}
  757. @classmethod
  758. def _init(cls, dir_path):
  759. '''Find out the thin pool containing given filesystem'''
  760. if dir_path not in cls._thin_pool:
  761. cls._thin_pool[dir_path] = None, None
  762. try:
  763. fs_stat = os.stat(dir_path)
  764. fs_major = (fs_stat.st_dev & 0xff00) >> 8
  765. fs_minor = fs_stat.st_dev & 0xff
  766. sudo = []
  767. if os.getuid():
  768. sudo = ['sudo']
  769. root_table = subprocess.check_output(sudo + ["dmsetup",
  770. "-j", str(fs_major), "-m", str(fs_minor),
  771. "table"], stderr=subprocess.DEVNULL)
  772. _start, _sectors, target_type, target_args = \
  773. root_table.decode().split(" ", 3)
  774. if target_type == "thin":
  775. thin_pool_devnum, _thin_pool_id = target_args.split(" ")
  776. with open("/sys/dev/block/{}/dm/name"
  777. .format(thin_pool_devnum), "r") as thin_pool_tpool_f:
  778. thin_pool_tpool = thin_pool_tpool_f.read().rstrip('\n')
  779. if thin_pool_tpool.endswith("-tpool"):
  780. volume_group, thin_pool, _tpool = \
  781. thin_pool_tpool.rsplit("-", 2)
  782. cls._thin_pool[dir_path] = volume_group, thin_pool
  783. except: # pylint: disable=bare-except
  784. pass
  785. @classmethod
  786. def thin_pool(cls, dir_path):
  787. '''Thin tuple (volume group, pool name) containing given filesystem'''
  788. cls._init(dir_path)
  789. return cls._thin_pool[dir_path]