#!/usr/bin/python2 # # The Qubes OS Project, http://www.qubes-os.org # # Copyright (C) 2013 Marek Marczykowski # # 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 re import subprocess import sys from qubes.qubes import QubesException, vm_files from qubes.storage import Pool, QubesVmStorage class XenStorage(QubesVmStorage): """ Class for VM storage of Xen VMs. """ def __init__(self, vm, vmdir, **kwargs): """ Instantiate the storage. Args: vm: a QubesVM vmdir: the root directory of the pool """ assert vm is not None assert vmdir is not None super(XenStorage, self).__init__(vm, **kwargs) self.vmdir = vmdir if self.vm.is_template(): self.rootcow_img = os.path.join(self.vmdir, vm_files["rootcow_img"]) else: self.rootcow_img = None self.private_img = os.path.join(vmdir, 'private.img') if self.vm.template: self.root_img = self.vm.template.root_img else: self.root_img = os.path.join(vmdir, 'root.img') self.volatile_img = os.path.join(vmdir, 'volatile.img') def root_dev_config(self): if self.vm.is_template() and self.rootcow_img: return self.format_disk_dev( "{root}:{rootcow}".format( root=self.root_img, rootcow=self.rootcow_img), "block-origin", self.root_dev, True) elif self.vm.template and not hasattr(self.vm, 'kernel'): # HVM template-based VM - only one device-mapper layer, in dom0 ( # root+volatile) # HVM detection based on 'kernel' property is massive hack, # but taken from assumption that VM needs Qubes-specific kernel ( # actually initramfs) to assemble the second layer of device-mapper return self.format_disk_dev( "{root}:{volatile}".format( root=self.vm.template.storage.root_img, volatile=self.volatile_img), "block-snapshot", self.root_dev, True) elif self.vm.template: # any other template-based VM - two device-mapper layers: one # in dom0 (here) from root+root-cow, and another one from # this+volatile.img return self.format_disk_dev( "{root}:{rootcow}".format( root=self.root_img, rootcow=self.vm.template.storage.rootcow_img), "block-snapshot", self.root_dev, False) else: return self.format_disk_dev( "{root}".format(root=self.root_img), None, self.root_dev, True) def private_dev_config(self): return self.format_disk_dev(self.private_img, None, self.private_dev, True) def volatile_dev_config(self): return self.format_disk_dev(self.volatile_img, None, self.volatile_dev, True) 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(XenStorage, 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() if not self.rootcow_img: return 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) def reset_volatile_storage(self, verbose = False, source_template = None): if source_template is None: source_template = self.vm.template if source_template is not None: # template-based VM with only one device-mapper layer - # volatile.img used as upper layer on root.img, no root-cow.img # intermediate layer if not source_template.storage.rootcow_img: if os.path.exists(self.volatile_img): if self.vm.debug: if os.path.getmtime(source_template.storage.root_img)\ > os.path.getmtime(self.volatile_img): if verbose: print >>sys.stderr, "--> WARNING: template have changed, resetting root.img" else: if verbose: print >>sys.stderr, "--> Debug mode: not resetting root.img" print >>sys.stderr, "--> Debug mode: if you want to force root.img reset, either update template VM, or remove volatile.img file" return os.remove(self.volatile_img) f_volatile = open(self.volatile_img, "w") f_root = open(source_template.storage.root_img, "r") f_root.seek(0, os.SEEK_END) f_volatile.truncate(f_root.tell()) # make empty sparse file of the same size as root.img f_volatile.close() f_root.close() return super(XenStorage, self).reset_volatile_storage( verbose=verbose, source_template=source_template) def prepare_for_vm_startup(self, verbose): super(XenStorage, self).prepare_for_vm_startup(verbose=verbose) if self.drive is not None: (drive_type, drive_domain, drive_path) = self.drive.split(":") if drive_domain.lower() != "dom0": try: # FIXME: find a better way to access QubesVmCollection drive_vm = self.vm._collection.get_vm_by_name(drive_domain) # prepare for improved QubesVmCollection if drive_vm is None: raise KeyError if not drive_vm.is_running(): raise QubesException( "VM '{}' holding '{}' isn't running".format( drive_domain, drive_path)) except KeyError: raise QubesException( "VM '{}' holding '{}' does not exists".format( drive_domain, drive_path)) class XenPool(Pool): def __init__(self, vm, dir_path): super(XenPool, self).__init__(vm, dir_path) def getStorage(self): """ Returns an instantiated ``XenStorage``. """ return XenStorage(self.vm, vmdir=self.vmdir)