core-admin/core-modules/01QubesDisposableVm.py

#!/usr/bin/python2
# -*- coding: utf-8 -*-
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2010  Joanna Rutkowska <joanna@invisiblethingslab.com>
# 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.
#
#

import os
import sys
import libvirt
import time
from qubes.qubes import QubesVm,QubesVmLabel,register_qubes_vm_class, \
    QubesException
from qubes.qubes import QubesDispVmLabels
from qubes.qubes import dry_run,vmm
import grp

qmemman_present = False
try:
    from qubes.qmemman_client import QMemmanClient
    qmemman_present = True
except ImportError:
    pass

DISPID_STATE_FILE = '/var/run/qubes/dispid'

class QubesDisposableVm(QubesVm):
    """
    A class that represents an DisposableVM. A child of QubesVm.
    """

    # In which order load this VM type from qubes.xml
    load_order = 120


    def _assign_new_dispid(self):
        # This method in called while lock on qubes.xml is held, so no need for
        # additional lock
        if os.path.exists(DISPID_STATE_FILE):
            f = open(DISPID_STATE_FILE, 'r+')
            dispid = int(f.read())
            f.seek(0)
            f.truncate(0)
            f.write(str(dispid+1))
            f.close()
        else:
            dispid = 1
            f = open(DISPID_STATE_FILE, 'w')
            f.write(str(dispid+1))
            f.close()
            os.chown(DISPID_STATE_FILE, -1, grp.getgrnam('qubes').gr_gid)
            os.chmod(DISPID_STATE_FILE, 0664)
        return dispid

    def get_attrs_config(self):
        attrs_config = super(QubesDisposableVm, self).get_attrs_config()

        attrs_config['name']['func'] = \
            lambda x: "disp%d" % self.dispid if x is None else x

        # New attributes
        attrs_config['dispid'] = {
            'func': lambda x: (self._assign_new_dispid() if x is None
                               else int(x)),
            'save': lambda: str(self.dispid),
            # needs to be set before name
            'order': 0
        }
        attrs_config['include_in_backups']['func'] = lambda x: False
        attrs_config['disp_savefile'] = {
                'default': '/var/run/qubes/current-savefile',
                'save': lambda: str(self.disp_savefile) }

        return attrs_config

    def __init__(self, **kwargs):

        disp_template = None
        if 'disp_template' in kwargs.keys():
            disp_template = kwargs['disp_template']
            kwargs['template'] = disp_template.template
            kwargs['dir_path'] = disp_template.dir_path
            kwargs['kernel'] = disp_template.kernel
            kwargs['uses_default_kernel'] = disp_template.uses_default_kernel
            kwargs['kernelopts'] = disp_template.kernelopts
            kwargs['uses_default_kernelopts'] = \
                disp_template.uses_default_kernelopts
        super(QubesDisposableVm, self).__init__(**kwargs)

        assert self.template is not None, "Missing template for DisposableVM!"

        if disp_template:
            self.clone_attrs(disp_template)

        # Use DispVM icon with the same color
        if self._label:
            self._label = QubesDispVmLabels[self._label.name]
            self.icon_path = self._label.icon_path

    @property
    def type(self):
        return "DisposableVM"

    def is_disposablevm(self):
        return True

    @property
    def ip(self):
        if self.netvm is not None:
            return self.netvm.get_ip_for_dispvm(self.dispid)
        else:
            return None

    def get_clone_attrs(self):
        attrs = super(QubesDisposableVm, self).get_clone_attrs()
        attrs.remove('_label')
        return attrs

    def do_not_use_get_xml_attrs(self):
        # Minimal set - do not inherit rest of attributes
        attrs = {}
        attrs["qid"] = str(self.qid)
        attrs["name"] = self.name
        attrs["dispid"] = str(self.dispid)
        attrs["template_qid"] = str(self.template.qid)
        attrs["label"] = self.label.name
        attrs["firewall_conf"] = self.relative_path(self.firewall_conf)
        attrs["netvm_qid"] = str(self.netvm.qid) if self.netvm is not None else "none"
        return attrs

    def verify_files(self):
        return True

    def get_config_params(self):
        attrs = super(QubesDisposableVm, self).get_config_params()
        attrs['privatedev'] = ''
        return attrs

    def create_qubesdb_entries(self):
        super(QubesDisposableVm, self).create_qubesdb_entries()

        self.qdb.write("/qubes-vm-persistence", "none")
        self.qdb.write('/qubes-restore-complete', '1')

    def start(self, verbose = False, **kwargs):
        self.log.debug('start()')
        if dry_run:
            return

        # Intentionally not used is_running(): eliminate also "Paused", "Crashed", "Halting"
        if self.get_power_state() != "Halted":
            raise QubesException ("VM is already running!")

        if self.netvm is not None:
            if self.netvm.qid != 0:
                if not self.netvm.is_running():
                    if verbose:
                        print >> sys.stderr, "--> Starting NetVM {0}...".\
                            format(self.netvm.name)
                    self.netvm.start(verbose=verbose, **kwargs)

        if verbose:
            print >> sys.stderr, "--> Loading the VM (type = {0})...".format(self.type)

        print >>sys.stderr, "time=%s, creating config file" % (str(time.time()))
        # refresh config file
        domain_config = self.create_config_file()

        qmemman_client = self.request_memory()

        # dispvm cannot have PCI devices
        assert (len(self.pcidevs) == 0), "DispVM cannot have PCI devices"

        print >>sys.stderr, "time=%s, calling restore" % (str(time.time()))
        vmm.libvirt_conn.restoreFlags(self.disp_savefile,
                domain_config, libvirt.VIR_DOMAIN_SAVE_PAUSED)

        print >>sys.stderr, "time=%s, done" % (str(time.time()))
        self._libvirt_domain = None

        if verbose:
            print >> sys.stderr, "--> Starting Qubes DB..."
        self.start_qubesdb()

        self.services['qubes-dvm'] = True
        if verbose:
            print >> sys.stderr, "--> Setting Qubes DB info for the VM..."
        self.create_qubesdb_entries()
        print >>sys.stderr, "time=%s, done qubesdb" % (str(time.time()))

        # fire hooks
        for hook in self.hooks_start:
            hook(self, verbose = verbose, **kwargs)

        if verbose:
            print >> sys.stderr, "--> Starting the VM..."
        self.libvirt_domain.resume()
        print >>sys.stderr, "time=%s, resumed" % (str(time.time()))

# close() is not really needed, because the descriptor is close-on-exec
# anyway, the reason to postpone close() is that possibly xl is not done
# constructing the domain after its main process exits
# so we close() when we know the domain is up
# the successful unpause is some indicator of it
        if qmemman_present:
            qmemman_client.close()

        if kwargs.get('start_guid', True) and os.path.exists('/var/run/shm.id'):
            self.start_guid(verbose=verbose, before_qrexec=True,
                    notify_function=kwargs.get('notify_function', None))

        self.start_qrexec_daemon(verbose=verbose,
                notify_function=kwargs.get('notify_function', None))
        print >>sys.stderr, "time=%s, qrexec done" % (str(time.time()))

        if kwargs.get('start_guid', True) and os.path.exists('/var/run/shm.id'):
            self.start_guid(verbose=verbose,
                    notify_function=kwargs.get('notify_function', None))
        print >>sys.stderr, "time=%s, guid done" % (str(time.time()))

        return self.xid

    def remove_from_disk(self):
        # nothing to remove
        pass

# register classes
register_qubes_vm_class(QubesDisposableVm)