os-vif/vif_plug_ovs/linux_net.py
Sean Mooney 9a14c18c21 introduces MTU support for vhost-user
- This change introduces the ability
  to set the MTU for vhost-user interface
  if supported by ovs.
- This change leverages the mtu_request
  option added to the ovs interface in ovs 2.6.
- MTU support enable the use of jumbo frames
  with vhost-user interfaces.

Change-Id: Ide3435b74809605692fa6153c3be3294db80182f
2017-01-09 16:36:20 +00:00

209 lines
7.3 KiB
Python

# Derived from nova/network/linux_net.py
#
# Copyright (c) 2011 X.commerce, a business unit of eBay Inc.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Implements vlans, bridges using linux utilities."""
import os
from oslo_concurrency import processutils
from oslo_log import log as logging
from oslo_utils import excutils
from vif_plug_ovs import constants
from vif_plug_ovs import exception
from vif_plug_ovs.i18n import _LE
from vif_plug_ovs import privsep
LOG = logging.getLogger(__name__)
def _ovs_vsctl(args, timeout=None):
full_args = ['ovs-vsctl']
if timeout is not None:
full_args += ['--timeout=%s' % timeout]
full_args += args
try:
return processutils.execute(*full_args)
except Exception as e:
LOG.error(_LE("Unable to execute %(cmd)s. Exception: %(exception)s"),
{'cmd': full_args, 'exception': e})
raise exception.AgentError(method=full_args)
def _create_ovs_vif_cmd(bridge, dev, iface_id, mac,
instance_id, interface_type=None,
vhost_server_path=None):
cmd = ['--', '--if-exists', 'del-port', dev, '--',
'add-port', bridge, dev,
'--', 'set', 'Interface', dev,
'external-ids:iface-id=%s' % iface_id,
'external-ids:iface-status=active',
'external-ids:attached-mac=%s' % mac,
'external-ids:vm-uuid=%s' % instance_id]
if interface_type:
cmd += ['type=%s' % interface_type]
if vhost_server_path:
cmd += ['options:vhost-server-path=%s' % vhost_server_path]
return cmd
def _create_ovs_bridge_cmd(bridge, datapath_type):
return ['--', '--may-exist', 'add-br', bridge,
'--', 'set', 'Bridge', bridge, 'datapath_type=%s' % datapath_type]
@privsep.vif_plug.entrypoint
def create_ovs_vif_port(bridge, dev, iface_id, mac, instance_id,
mtu=None, interface_type=None, timeout=None,
vhost_server_path=None):
_ovs_vsctl(_create_ovs_vif_cmd(bridge, dev, iface_id,
mac, instance_id, interface_type,
vhost_server_path), timeout=timeout)
_update_device_mtu(dev, mtu, interface_type, timeout=timeout)
@privsep.vif_plug.entrypoint
def update_ovs_vif_port(dev, mtu=None, interface_type=None, timeout=None):
_update_device_mtu(dev, mtu, interface_type, timeout=timeout)
@privsep.vif_plug.entrypoint
def delete_ovs_vif_port(bridge, dev, timeout=None):
_ovs_vsctl(['--', '--if-exists', 'del-port', bridge, dev],
timeout=timeout)
_delete_net_dev(dev)
def device_exists(device):
"""Check if ethernet device exists."""
return os.path.exists('/sys/class/net/%s' % device)
def _delete_net_dev(dev):
"""Delete a network device only if it exists."""
if device_exists(dev):
try:
processutils.execute('ip', 'link', 'delete', dev,
check_exit_code=[0, 2, 254])
LOG.debug("Net device removed: '%s'", dev)
except processutils.ProcessExecutionError:
with excutils.save_and_reraise_exception():
LOG.error(_LE("Failed removing net device: '%s'"), dev)
@privsep.vif_plug.entrypoint
def create_veth_pair(dev1_name, dev2_name, mtu):
"""Create a pair of veth devices with the specified names,
deleting any previous devices with those names.
"""
for dev in [dev1_name, dev2_name]:
_delete_net_dev(dev)
processutils.execute('ip', 'link', 'add', dev1_name,
'type', 'veth', 'peer', 'name', dev2_name)
for dev in [dev1_name, dev2_name]:
processutils.execute('ip', 'link', 'set', dev, 'up')
processutils.execute('ip', 'link', 'set', dev, 'promisc', 'on')
_update_device_mtu(dev, mtu)
@privsep.vif_plug.entrypoint
def update_veth_pair(dev1_name, dev2_name, mtu):
"""Update a pair of veth devices with new configuration."""
for dev in [dev1_name, dev2_name]:
_update_device_mtu(dev, mtu)
@privsep.vif_plug.entrypoint
def ensure_ovs_bridge(bridge, datapath_type):
_ovs_vsctl(_create_ovs_bridge_cmd(bridge, datapath_type))
@privsep.vif_plug.entrypoint
def ensure_bridge(bridge):
if not device_exists(bridge):
processutils.execute('brctl', 'addbr', bridge)
processutils.execute('brctl', 'setfd', bridge, 0)
processutils.execute('brctl', 'stp', bridge, 'off')
syspath = '/sys/class/net/%s/bridge/multicast_snooping'
syspath = syspath % bridge
processutils.execute('tee', syspath, process_input='0',
check_exit_code=[0, 1])
disv6 = ('/proc/sys/net/ipv6/conf/%s/disable_ipv6' %
bridge)
if os.path.exists(disv6):
processutils.execute('tee',
disv6,
process_input='1',
check_exit_code=[0, 1])
@privsep.vif_plug.entrypoint
def delete_bridge(bridge, dev):
if device_exists(bridge):
processutils.execute('brctl', 'delif', bridge, dev)
processutils.execute('ip', 'link', 'set', bridge, 'down')
processutils.execute('brctl', 'delbr', bridge)
@privsep.vif_plug.entrypoint
def add_bridge_port(bridge, dev):
processutils.execute('ip', 'link', 'set', bridge, 'up')
processutils.execute('brctl', 'addif', bridge, dev)
def _update_device_mtu(dev, mtu, interface_type=None, timeout=120):
if not mtu:
return
if interface_type not in [
constants.OVS_VHOSTUSER_INTERFACE_TYPE,
constants.OVS_VHOSTUSER_CLIENT_INTERFACE_TYPE]:
_set_device_mtu(dev, mtu)
elif _ovs_supports_mtu_requests(timeout=timeout):
_set_mtu_request(dev, mtu, timeout=timeout)
else:
LOG.debug("MTU not set on %(interface_name)s interface "
"of type %(interface_type)s.",
{'interface_name': dev,
'interface_type': interface_type})
@privsep.vif_plug.entrypoint
def _set_device_mtu(dev, mtu):
"""Set the device MTU."""
processutils.execute('ip', 'link', 'set', dev, 'mtu', mtu,
check_exit_code=[0, 2, 254])
@privsep.vif_plug.entrypoint
def _set_mtu_request(dev, mtu, timeout=None):
args = ['--', 'set', 'interface', dev,
'mtu_request=%s' % mtu]
_ovs_vsctl(args, timeout=timeout)
@privsep.vif_plug.entrypoint
def _ovs_supports_mtu_requests(timeout=None):
args = ['--columns=mtu_request', 'list', 'interface']
_, error = _ovs_vsctl(args, timeout=timeout)
if (error == 'ovs-vsctl: Interface does not contain' +
' a column whose name matches "mtu_request"'):
return False
return True