vmware-nsx/neutron/agent/linux/ip_lib.py
Francois Eleouet 81e793d9f1 Vxlan / L2population support to Linuxbridge Agent
This patch introduces VXLAN support for Linuxbridge agent alongside
with ml2 plugin support in linubridge mechnism driver.

A new vxlan configuration section is added for vxlan related parameters.

The agent also implements l2population RPC callbacks which allows ml2
plugin using l2population mechnism driver to populate vxlan forwarding
and neighbor tables following portbinding events. It allows agent to
respond locally to ARP requests for remote VMs and avoid dataplane based
learning. This should help limiting the use of multicast or flooding
for broadcast emulation in vxlan networks.

These changes should anyway have a limited risk, as agent behaviour
shouldn't be affected, except when vxlan is enabled alongside ml2 plugin.

Implements: blueprint l2-population

Change-Id: I99a961c53f9e451409f1affb079042936d8ae5c6
2013-09-12 02:51:37 +02:00

480 lines
16 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 OpenStack Foundation
# 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.
import netaddr
from oslo.config import cfg
from neutron.agent.linux import utils
from neutron.common import exceptions
OPTS = [
cfg.BoolOpt('ip_lib_force_root',
default=False,
help=_('Force ip_lib calls to use the root helper')),
]
LOOPBACK_DEVNAME = 'lo'
class SubProcessBase(object):
def __init__(self, root_helper=None, namespace=None):
self.root_helper = root_helper
self.namespace = namespace
try:
self.force_root = cfg.CONF.ip_lib_force_root
except cfg.NoSuchOptError:
# Only callers that need to force use of the root helper
# need to register the option.
self.force_root = False
def _run(self, options, command, args):
if self.namespace:
return self._as_root(options, command, args)
elif self.force_root:
# Force use of the root helper to ensure that commands
# will execute in dom0 when running under XenServer/XCP.
return self._execute(options, command, args, self.root_helper)
else:
return self._execute(options, command, args)
def _as_root(self, options, command, args, use_root_namespace=False):
if not self.root_helper:
raise exceptions.SudoRequired()
namespace = self.namespace if not use_root_namespace else None
return self._execute(options,
command,
args,
self.root_helper,
namespace)
@classmethod
def _execute(cls, options, command, args, root_helper=None,
namespace=None):
opt_list = ['-%s' % o for o in options]
if namespace:
ip_cmd = ['ip', 'netns', 'exec', namespace, 'ip']
else:
ip_cmd = ['ip']
return utils.execute(ip_cmd + opt_list + [command] + list(args),
root_helper=root_helper)
class IPWrapper(SubProcessBase):
def __init__(self, root_helper=None, namespace=None):
super(IPWrapper, self).__init__(root_helper=root_helper,
namespace=namespace)
self.netns = IpNetnsCommand(self)
def device(self, name):
return IPDevice(name, self.root_helper, self.namespace)
def get_devices(self, exclude_loopback=False):
retval = []
output = self._execute('o', 'link', ('list',),
self.root_helper, self.namespace)
for line in output.split('\n'):
if '<' not in line:
continue
tokens = line.split(':', 2)
if len(tokens) >= 3:
name = tokens[1].strip()
if exclude_loopback and name == LOOPBACK_DEVNAME:
continue
retval.append(IPDevice(name,
self.root_helper,
self.namespace))
return retval
def add_tuntap(self, name, mode='tap'):
self._as_root('', 'tuntap', ('add', name, 'mode', mode))
return IPDevice(name, self.root_helper, self.namespace)
def add_veth(self, name1, name2, namespace2=None):
args = ['add', name1, 'type', 'veth', 'peer', 'name', name2]
if namespace2 is None:
namespace2 = self.namespace
else:
self.ensure_namespace(namespace2)
args += ['netns', namespace2]
self._as_root('', 'link', tuple(args))
return (IPDevice(name1, self.root_helper, self.namespace),
IPDevice(name2, self.root_helper, namespace2))
def ensure_namespace(self, name):
if not self.netns.exists(name):
ip = self.netns.add(name)
lo = ip.device(LOOPBACK_DEVNAME)
lo.link.set_up()
else:
ip = IPWrapper(self.root_helper, name)
return ip
def namespace_is_empty(self):
return not self.get_devices(exclude_loopback=True)
def garbage_collect_namespace(self):
"""Conditionally destroy the namespace if it is empty."""
if self.namespace and self.netns.exists(self.namespace):
if self.namespace_is_empty():
self.netns.delete(self.namespace)
return True
return False
def add_device_to_namespace(self, device):
if self.namespace:
device.link.set_netns(self.namespace)
def add_vxlan(self, name, vni, group=None, dev=None, ttl=None, tos=None,
local=None, port=None):
cmd = ['add', name, 'type', 'vxlan', 'id', vni, 'proxy']
if group:
cmd.extend(['group', group])
if dev:
cmd.extend(['dev', dev])
if ttl:
cmd.extend(['ttl', ttl])
if tos:
cmd.extend(['tos', tos])
if local:
cmd.extend(['local', local])
# tuple: min,max
if port and len(port) == 2:
cmd.extend(['port', port[0], port[1]])
elif port:
raise exceptions.NetworkVxlanPortRangeError(vxlan_range=port)
self._as_root('', 'link', cmd)
return (IPDevice(name, self.root_helper, self.namespace))
@classmethod
def get_namespaces(cls, root_helper):
output = cls._execute('', 'netns', ('list',), root_helper=root_helper)
return [l.strip() for l in output.split('\n')]
class IPDevice(SubProcessBase):
def __init__(self, name, root_helper=None, namespace=None):
super(IPDevice, self).__init__(root_helper=root_helper,
namespace=namespace)
self.name = name
self.link = IpLinkCommand(self)
self.addr = IpAddrCommand(self)
self.route = IpRouteCommand(self)
def __eq__(self, other):
return (other is not None and self.name == other.name
and self.namespace == other.namespace)
def __str__(self):
return self.name
class IpCommandBase(object):
COMMAND = ''
def __init__(self, parent):
self._parent = parent
def _run(self, *args, **kwargs):
return self._parent._run(kwargs.get('options', []), self.COMMAND, args)
def _as_root(self, *args, **kwargs):
return self._parent._as_root(kwargs.get('options', []),
self.COMMAND,
args,
kwargs.get('use_root_namespace', False))
class IpDeviceCommandBase(IpCommandBase):
@property
def name(self):
return self._parent.name
class IpLinkCommand(IpDeviceCommandBase):
COMMAND = 'link'
def set_address(self, mac_address):
self._as_root('set', self.name, 'address', mac_address)
def set_mtu(self, mtu_size):
self._as_root('set', self.name, 'mtu', mtu_size)
def set_up(self):
self._as_root('set', self.name, 'up')
def set_down(self):
self._as_root('set', self.name, 'down')
def set_netns(self, namespace):
self._as_root('set', self.name, 'netns', namespace)
self._parent.namespace = namespace
def set_name(self, name):
self._as_root('set', self.name, 'name', name)
self._parent.name = name
def set_alias(self, alias_name):
self._as_root('set', self.name, 'alias', alias_name)
def delete(self):
self._as_root('delete', self.name)
@property
def address(self):
return self.attributes.get('link/ether')
@property
def state(self):
return self.attributes.get('state')
@property
def mtu(self):
return self.attributes.get('mtu')
@property
def qdisc(self):
return self.attributes.get('qdisc')
@property
def qlen(self):
return self.attributes.get('qlen')
@property
def alias(self):
return self.attributes.get('alias')
@property
def attributes(self):
return self._parse_line(self._run('show', self.name, options='o'))
def _parse_line(self, value):
if not value:
return {}
device_name, settings = value.replace("\\", '').split('>', 1)
tokens = settings.split()
keys = tokens[::2]
values = [int(v) if v.isdigit() else v for v in tokens[1::2]]
retval = dict(zip(keys, values))
return retval
class IpAddrCommand(IpDeviceCommandBase):
COMMAND = 'addr'
def add(self, ip_version, cidr, broadcast, scope='global'):
self._as_root('add',
cidr,
'brd',
broadcast,
'scope',
scope,
'dev',
self.name,
options=[ip_version])
def delete(self, ip_version, cidr):
self._as_root('del',
cidr,
'dev',
self.name,
options=[ip_version])
def flush(self):
self._as_root('flush', self.name)
def list(self, scope=None, to=None, filters=None):
if filters is None:
filters = []
retval = []
if scope:
filters += ['scope', scope]
if to:
filters += ['to', to]
for line in self._run('show', self.name, *filters).split('\n'):
line = line.strip()
if not line.startswith('inet'):
continue
parts = line.split()
if parts[0] == 'inet6':
version = 6
scope = parts[3]
broadcast = '::'
else:
version = 4
if parts[2] == 'brd':
broadcast = parts[3]
scope = parts[5]
else:
# sometimes output of 'ip a' might look like:
# inet 192.168.100.100/24 scope global eth0
# and broadcast needs to be calculated from CIDR
broadcast = str(netaddr.IPNetwork(parts[1]).broadcast)
scope = parts[3]
retval.append(dict(cidr=parts[1],
broadcast=broadcast,
scope=scope,
ip_version=version,
dynamic=('dynamic' == parts[-1])))
return retval
class IpRouteCommand(IpDeviceCommandBase):
COMMAND = 'route'
def add_gateway(self, gateway, metric=None):
args = ['replace', 'default', 'via', gateway]
if metric:
args += ['metric', metric]
args += ['dev', self.name]
self._as_root(*args)
def delete_gateway(self, gateway):
self._as_root('del',
'default',
'via',
gateway,
'dev',
self.name)
def get_gateway(self, scope=None, filters=None):
if filters is None:
filters = []
retval = None
if scope:
filters += ['scope', scope]
route_list_lines = self._run('list', 'dev', self.name,
*filters).split('\n')
default_route_line = next((x.strip() for x in
route_list_lines if
x.strip().startswith('default')), None)
if default_route_line:
gateway_index = 2
parts = default_route_line.split()
retval = dict(gateway=parts[gateway_index])
metric_index = 4
parts_has_metric = (len(parts) > metric_index)
if parts_has_metric:
retval.update(metric=int(parts[metric_index]))
return retval
def pullup_route(self, interface_name):
"""Ensures that the route entry for the interface is before all
others on the same subnet.
"""
device_list = []
device_route_list_lines = self._run('list', 'proto', 'kernel',
'dev', interface_name).split('\n')
for device_route_line in device_route_list_lines:
try:
subnet = device_route_line.split()[0]
except Exception:
continue
subnet_route_list_lines = self._run('list', 'proto', 'kernel',
'match', subnet).split('\n')
for subnet_route_line in subnet_route_list_lines:
i = iter(subnet_route_line.split())
while(i.next() != 'dev'):
pass
device = i.next()
try:
while(i.next() != 'src'):
pass
src = i.next()
except Exception:
src = ''
if device != interface_name:
device_list.append((device, src))
else:
break
for (device, src) in device_list:
self._as_root('del', subnet, 'dev', device)
if (src != ''):
self._as_root('append', subnet, 'proto', 'kernel',
'src', src, 'dev', device)
else:
self._as_root('append', subnet, 'proto', 'kernel',
'dev', device)
class IpNetnsCommand(IpCommandBase):
COMMAND = 'netns'
def add(self, name):
self._as_root('add', name, use_root_namespace=True)
return IPWrapper(self._parent.root_helper, name)
def delete(self, name):
self._as_root('delete', name, use_root_namespace=True)
def execute(self, cmds, addl_env={}, check_exit_code=True):
if not self._parent.root_helper:
raise exceptions.SudoRequired()
elif not self._parent.namespace:
raise Exception(_('No namespace defined for parent'))
else:
env_params = []
if addl_env:
env_params = (['env'] +
['%s=%s' % pair for pair in addl_env.items()])
return utils.execute(
['ip', 'netns', 'exec', self._parent.namespace] +
env_params + list(cmds),
root_helper=self._parent.root_helper,
check_exit_code=check_exit_code)
def exists(self, name):
output = self._as_root('list', options='o', use_root_namespace=True)
for line in output.split('\n'):
if name == line.strip():
return True
return False
def device_exists(device_name, root_helper=None, namespace=None):
try:
address = IPDevice(device_name, root_helper, namespace).link.address
except RuntimeError:
return False
return bool(address)
def iproute_arg_supported(command, arg, root_helper=None):
command += ['help']
stdout, stderr = utils.execute(command, root_helper=root_helper,
check_exit_code=False, return_stderr=True)
return any(arg in line for line in stderr.split('\n'))