#!/usr/bin/python2
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2013 Marek Marczykowski <marmarek@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.
#
#
from __future__ import absolute_import
import os
import os.path
import subprocess
import sys
import re
from qubes.storage import QubesVmStorage
from qubes.qubes import QubesException, vm_files
class QubesXenVmStorage(QubesVmStorage):
"""
Class for VM storage of Xen VMs.
"""
def __init__(self, vm, **kwargs):
super(QubesXenVmStorage, self).__init__(vm, **kwargs)
self.root_dev = "xvda"
self.private_dev = "xvdb"
self.volatile_dev = "xvdc"
self.modules_dev = "xvdd"
if self.vm.is_template():
self.rootcow_img = os.path.join(self.vmdir, vm_files["rootcow_img"])
else:
self.rootcow_img = None
def _format_disk_dev(self, path, script, vdev, rw=True, type="disk", domain=None):
if path is None:
return ''
template = " <disk type='block' device='{type}'>\n" \
" <driver name='phy'/>\n" \
" <source dev='{path}'/>\n" \
" <target dev='{vdev}' bus='xen'/>\n" \
"{params}" \
" </disk>\n"
params = ""
if not rw:
params += " <readonly/>\n"
if domain:
params += " <backenddomain name='%s'/>\n" % domain
if script:
params += " <script path='%s'/>\n" % script
return template.format(path=path, vdev=vdev, type=type,
params=params)
def _get_rootdev(self):
if self.vm.is_template() and \
os.path.exists(os.path.join(self.vmdir, "root-cow.img")):
return self._format_disk_dev(
"{dir}/root.img:{dir}/root-cow.img".format(
dir=self.vmdir),
"block-origin", self.root_dev, True)
elif self.vm.template:
return self._format_disk_dev(
"{dir}/root.img:{dir}/root-cow.img".format(
dir=self.vm.template.dir_path),
"block-snapshot", self.root_dev, False)
else:
return self._format_disk_dev(
"{dir}/root.img".format(dir=self.vmdir),
None, self.root_dev, True)
def get_config_params(self):
args = {}
args['rootdev'] = self._get_rootdev()
args['privatedev'] = \
self._format_disk_dev(self.private_img,
None, self.private_dev, True)
args['volatiledev'] = \
self._format_disk_dev(self.volatile_img,
None, self.volatile_dev, True)
if self.modules_img is not None:
args['otherdevs'] = \
self._format_disk_dev(self.modules_img,
None, self.modules_dev, self.modules_img_rw)
elif self.drive is not None:
(drive_type, drive_domain, drive_path) = self.drive.split(":")
if drive_domain.lower() == "dom0":
drive_domain = None
args['otherdevs'] = self._format_disk_dev(drive_path, None,
self.modules_dev,
rw=True if drive_type == "disk" else False, type=drive_type,
domain=drive_domain)
else:
args['otherdevs'] = ''
return args
def create_on_disk_private_img(self, verbose, source_template = None):
if source_template:
template_priv = source_template.private_img
if verbose:
print >> sys.stderr, "--> Copying the template's private image: {0}".\
format(template_priv)
self._copy_file(template_priv, self.private_img)
else:
f_private = open (self.private_img, "a+b")
f_private.truncate (self.private_img_size)
f_private.close ()
def create_on_disk_root_img(self, verbose, source_template = None):
if source_template:
if not self.vm.updateable:
# just use template's disk
return
else:
template_root = source_template.root_img
if verbose:
print >> sys.stderr, "--> Copying the template's root image: {0}".\
format(template_root)
self._copy_file(template_root, self.root_img)
else:
f_root = open (self.root_img, "a+b")
f_root.truncate (self.root_img_size)
f_root.close ()
if self.vm.is_template():
self.commit_template_changes()
def rename(self, old_name, new_name):
super(QubesXenVmStorage, self).rename(old_name, new_name)
old_dirpath = os.path.join(os.path.dirname(self.vmdir), old_name)
if self.rootcow_img:
self.rootcow_img = self.rootcow_img.replace(old_dirpath,
self.vmdir)
def resize_private_img(self, size):
f_private = open (self.private_img, "a+b")
f_private.truncate (size)
f_private.close ()
# find loop device if any
p = subprocess.Popen (["sudo", "losetup", "--associated", self.private_img],
stdout=subprocess.PIPE)
result = p.communicate()
m = re.match(r"^(/dev/loop\d+):\s", result[0])
if m is not None:
loop_dev = m.group(1)
# resize loop device
subprocess.check_call(["sudo", "losetup", "--set-capacity", loop_dev])
def commit_template_changes(self):
assert self.vm.is_template()
# TODO: move rootcow_img to this class; the same for vm.is_outdated()
if os.path.exists (self.rootcow_img):
os.rename (self.rootcow_img, self.rootcow_img + '.old')
old_umask = os.umask(002)
f_cow = open (self.rootcow_img, "w")
f_root = open (self.root_img, "r")
f_root.seek(0, os.SEEK_END)
f_cow.truncate (f_root.tell()) # make empty sparse file of the same size as root.img
f_cow.close ()
f_root.close()
os.umask(old_umask)