Mark McClain 7dcaeecfd5 netns commands should always run in the root ns
fixes bug 1044542

Previously, some netns commands were executed in the context of the
namespace defined in the wrapper. These commands should be be executed in
the root namespace for the most reliable results.

Change-Id: I4915aa6f75af3f65ce2adb40360bcd841f549239
2012-09-01 15:11:52 -04:00

348 lines
11 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 OpenStack LLC
# 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.
from quantum.agent.linux import utils
from quantum.common import exceptions
class SubProcessBase(object):
def __init__(self, root_helper=None, namespace=None):
self.root_helper = root_helper
self.namespace = namespace
def _run(self, options, command, args):
if self.namespace:
return self._as_root(options, command, args)
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):
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:
retval.append(IPDevice(tokens[1].strip(),
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):
self._as_root('', 'link',
('add', name1, 'type', 'veth', 'peer', 'name', name2))
return (IPDevice(name1, self.root_helper, self.namespace),
IPDevice(name2, self.root_helper, self.namespace))
def ensure_namespace(self, name):
if not self.netns.exists(name):
ip = self.netns.add(name)
lo = ip.device('lo')
lo.link.set_up()
else:
ip = IPWrapper(self.root_helper, name)
return ip
def add_device_to_namespace(self, device):
if self.namespace:
device.link.set_netns(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 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 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
broadcast = parts[3]
scope = parts[5]
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 = ['add', '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
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={}):
if not self._parent.root_helper:
raise exceptions.SudoRequired()
elif not self._parent.namespace:
raise Exception(_('No namespace defined for parent'))
else:
return utils.execute(
['%s=%s' % pair for pair in addl_env.items()] +
['ip', 'netns', 'exec', self._parent.namespace] + list(cmds),
root_helper=self._parent.root_helper)
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)