core-admin/qubes/vm/mix/net.py
Marek Marczykowski-Górecki 3b1238f7cf vm: stub for new firewall API
- introduce 'firewall-changed' event
 - add reload_firewall_for_vm stub function

Should that function be private, called only from appropriate event
handlers?

QubesOS/qubes-issues#1815
2016-03-21 11:43:33 +01:00

314 lines
10 KiB
Python

#!/usr/bin/python2 -O
# vim: fileencoding=utf-8
#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2010-2016 Joanna Rutkowska <joanna@invisiblethingslab.com>
# Copyright (C) 2013-2016 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
# Copyright (C) 2014-2016 Wojtek Porczyk <woju@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 shutil
import time
import libvirt
import lxml.etree
import qubes
import qubes.exc
class NetVMMixin(object):
mac = qubes.property('mac', type=str,
default=(lambda self: '00:16:3E:5E:6C:{:02X}'.format(self.qid)),
ls_width=17,
doc='MAC address of the NIC emulated inside VM')
# XXX swallowed uses_default_netvm
netvm = qubes.VMProperty('netvm', load_stage=4, allow_none=True,
default=(lambda self: self.app.default_fw_netvm if self.provides_network
else self.app.default_netvm),
ls_width=31,
doc='''VM that provides network connection to this domain. When
`None`, machine is disconnected. When absent, domain uses default
NetVM.''')
provides_network = qubes.property('provides_network', default=False,
type=bool, setter=qubes.property.bool,
doc='''If this domain can act as network provider (formerly known as
NetVM or ProxyVM)''')
#
# used in networked appvms or proxyvms (netvm is not None)
#
@qubes.tools.qvm_ls.column(width=15)
@property
def ip(self):
'''IP address of this domain.'''
if not self.is_networked():
return None
if self.netvm is not None:
return self.netvm.get_ip_for_vm(self)
else:
return self.get_ip_for_vm(self)
#
# used in netvms (provides_network=True)
# those properties and methods are most likely accessed as vm.netvm.<prop>
#
@staticmethod
def get_ip_for_vm(vm):
'''Get IP address for (appvm) domain connected to this (netvm) domain.
'''
import qubes.vm.dispvm # pylint: disable=redefined-outer-name
if isinstance(vm, qubes.vm.dispvm.DispVM):
return '10.138.{}.{}'.format((vm.dispid >> 8) & 7, vm.dispid & 7)
# VM technically can get address which ends in '.0'. This currently
# does not happen, because qid < 253, but may happen in the future.
return '10.137.{}.{}'.format((vm.qid >> 8) & 7, vm.qid & 7)
@qubes.tools.qvm_ls.column(head='IPBACK', width=15)
@property
def gateway(self):
'''Gateway for other domains that use this domain as netvm.'''
return self.ip if self.provides_network else None
@qubes.tools.qvm_ls.column(width=15)
@property
def netmask(self):
'''Netmask for gateway address.'''
return '255.255.255.255' if self.is_networked() else None
@qubes.tools.qvm_ls.column(width=7)
@property
def vif(self):
'''Name of the network interface backend in netvm that is connected to
NIC inside this domain.'''
if self.xid < 0:
return None
if self.netvm is None:
return None
return "vif{0}.+".format(self.xid)
@property
def connected_vms(self):
for vm in self.app.domains:
if vm.netvm is self:
yield vm
#
# used in both
#
@qubes.tools.qvm_ls.column(width=15)
@property
def dns(self):
'''Secondary DNS server set up for this domain.'''
if self.netvm is not None or self.provides_network:
return (
'10.139.1.1',
'10.139.1.2',
)
else:
return None
def __init__(self, *args, **kwargs):
super(NetVMMixin, self).__init__(*args, **kwargs)
@qubes.events.handler('domain-started')
def start_net(self):
'''Connect this domain to its downstream domains.
This is needed when starting netvm *after* its connected domains.
'''
for vm in self.connected_vms:
if not vm.is_running():
continue
vm.log.info('Attaching network')
# 1426
vm.cleanup_vifs()
try:
# 1426
vm.run('modprobe -r xen-netfront xennet',
user='root', wait=True)
except:
pass
try:
vm.attach_network(wait=False)
except qubes.exc.QubesException:
vm.log.warning('Cannot attach network', exc_info=1)
@qubes.events.handler('pre-domain-shutdown')
def shutdown_net(self, force=False):
connected_vms = [vm for vm in self.connected_vms if vm.is_running()]
if connected_vms and not force:
raise qubes.exc.QubesVMError(
'There are other VMs connected to this VM: {}'.format(
', '.join(vm.name for vm in connected_vms)))
# detach network interfaces of connected VMs before shutting down,
# otherwise libvirt will not notice it and will try to detach them
# again (which would fail, obviously).
# This code can be removed when #1426 got implemented
for vm in connected_vms:
if vm.is_running():
try:
vm.detach_network()
except (qubes.exc.QubesException, libvirt.libvirtError):
# ignore errors
pass
# TODO maybe this should be other way: backend.devices['net'].attach(self)
def attach_network(self):
'''Attach network in this machine to it's netvm.'''
if not self.is_running():
raise qubes.exc.QubesVMNotRunningError(self)
assert self.netvm is not None
if not self.netvm.is_running():
self.log.info('Starting NetVM ({0})'.format(self.netvm.name))
self.netvm.start()
self.libvirt_domain.attachDevice(lxml.etree.ElementTree(
self.lvxml_net_dev(self.ip, self.mac, self.netvm)).tostring())
def detach_network(self):
'''Detach machine from it's netvm'''
if not self.is_running():
raise qubes.exc.QubesVMNotRunningError(self)
assert self.netvm is not None
self.libvirt_domain.detachDevice(lxml.etree.ElementTree(
self.lvxml_net_dev(self.ip, self.mac, self.netvm)).tostring())
def is_networked(self):
'''Check whether this VM can reach network (firewall notwithstanding).
:returns: :py:obj:`True` if is machine can reach network, \
:py:obj:`False` otherwise.
:rtype: bool
'''
if self.provides_network:
return True
return self.netvm is not None
def cleanup_vifs(self):
'''Remove stale network device backends.
Libvirt does not remove vif when backend domain is down, so we must do
it manually. This method is one big hack for #1426.
'''
# FIXME: remove this?
if not self.is_running():
return
dev_basepath = '/local/domain/%d/device/vif' % self.xid
for dev in self.app.vmm.xs.ls('', dev_basepath):
# check if backend domain is alive
backend_xid = int(self.app.vmm.xs.read('',
'{}/{}/backend-id'.format(dev_basepath, dev)))
if backend_xid in self.app.vmm.libvirt_conn.listDomainsID():
# check if device is still active
if self.app.vmm.xs.read('',
'{}/{}/state'.format(dev_basepath, dev)) == '4':
continue
# remove dead device
self.app.vmm.xs.rm('', '{}/{}'.format(dev_basepath, dev))
def reload_firewall_for_vm(self, vm):
# TODO QubesOS/qubes-issues#1815
pass
@qubes.events.handler('property-del:netvm')
def on_property_del_netvm(self, event, name, old_netvm):
# pylint: disable=unused-argument
# we are changing to default netvm
new_netvm = self.netvm
if new_netvm == old_netvm:
return
self.fire_event('property-set:netvm', 'netvm', new_netvm, old_netvm)
@qubes.events.handler('property-set:netvm')
def on_property_set_netvm(self, event, name, new_netvm, old_netvm=None):
# pylint: disable=unused-argument
# TODO offline_mode
if self.is_running() and new_netvm is not None \
and not new_netvm.is_running():
raise qubes.exc.QubesVMNotStartedError(new_netvm,
'Cannot dynamically attach to stopped NetVM: {!r}'.format(
new_netvm))
if self.netvm is not None:
if self.is_running():
self.detach_network()
# TODO change to domain-removed event handler in netvm
# if hasattr(self.netvm, 'post_vm_net_detach'):
# self.netvm.post_vm_net_detach(self)
if new_netvm is None:
return
if self.is_running():
# refresh IP, DNS etc
self.create_qdb_entries()
self.attach_network()
# TODO documentation
new_netvm.fire_event('net-domain-connect', self)
# FIXME handle in the above event?
new_netvm.reload_firewall_for_vm(self)
@qubes.events.handler('qdb-created')
def on_qdb_created(self, event):
# TODO: fill firewall QubesDB entries (QubesOS/qubes-issues#1815)
pass
# FIXME use event after creating Xen domain object, but before "resume"
@qubes.events.handler('domain-started')
def on_domain_started(self, event, **kwargs):
if self.netvm:
self.netvm.reload_firewall_for_vm(self)
@qubes.events.handler('firewall-changed')
def on_firewall_changed(self, event):
if self.is_running() and self.netvm:
self.netvm.reload_firewall_for_vm(self)