OpenStack Networking (Neutron)
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# 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
# 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 os
import re
import eventlet
import netaddr
from neutron_lib import constants
from neutron_lib import exceptions
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import excutils
import six
from neutron._i18n import _, _LE, _LW
from neutron.agent.common import utils
from neutron.common import exceptions as n_exc
from neutron.common import utils as common_utils
LOG = logging.getLogger(__name__)
OPTS = [
help=_('Force ip_lib calls to use the root helper')),
IP_NONLOCAL_BIND = 'net.ipv4.ip_nonlocal_bind'
GRE_TUNNEL_DEVICE_NAMES = ['gre0', 'gretap0']
SYS_NET_PATH = '/sys/class/net'
DEFAULT_GW_PATTERN = re.compile(r"via (\S+)")
METRIC_PATTERN = re.compile(r"metric (\S+)")
DEVICE_NAME_PATTERN = re.compile(r"(\d+?): (\S+?):.*")
def remove_interface_suffix(interface):
"""Remove a possible "<if>@<endpoint>" suffix from an interface' name.
This suffix can appear in some kernel versions, and intends on specifying,
for example, a veth's pair. However, this interface name is useless to us
as further 'ip' commands require that the suffix be removed.
# If '@' is not present, this will do nothing.
return interface.partition("@")[0]
class AddressNotReady(exceptions.NeutronException):
message = _("Failure waiting for address %(address)s to "
"become ready: %(reason)s")
class SubProcessBase(object):
def __init__(self, namespace=None,
self.namespace = namespace
self.log_fail_as_error = log_fail_as_error
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, run_as_root=True,
return self._execute(options, command, args,
def _as_root(self, options, command, args, use_root_namespace=False):
namespace = self.namespace if not use_root_namespace else None
return self._execute(options, command, args, run_as_root=True,
def _execute(cls, options, command, args, run_as_root=False,
namespace=None, log_fail_as_error=True):
opt_list = ['-%s' % o for o in options]
ip_cmd = add_namespace_to_cmd(['ip'], namespace)
cmd = ip_cmd + opt_list + [command] + list(args)
return utils.execute(cmd, run_as_root=run_as_root,
def set_log_fail_as_error(self, fail_with_error):
self.log_fail_as_error = fail_with_error
def get_log_fail_as_error(self):
return self.log_fail_as_error
class IPWrapper(SubProcessBase):
def __init__(self, namespace=None):
super(IPWrapper, self).__init__(namespace=namespace)
self.netns = IpNetnsCommand(self)
def device(self, name):
return IPDevice(name, namespace=self.namespace)
def get_devices(self, exclude_loopback=False, exclude_gre_devices=False):
retval = []
if self.namespace:
# we call out manually because in order to avoid screen scraping
# iproute2 we use find to see what is in the sysfs directory, as
# suggested by Stephen Hemminger (iproute2 dev).
cmd = ['ip', 'netns', 'exec', self.namespace,
'find', SYS_NET_PATH, '-maxdepth', '1',
'-type', 'l', '-printf', '%f ']
output = utils.execute(
except RuntimeError:
# We could be racing with a cron job deleting namespaces.
# Just return a empty list if the namespace is deleted.
with excutils.save_and_reraise_exception() as ctx:
if not self.netns.exists(self.namespace):
ctx.reraise = False
return []
output = (
i for i in os.listdir(SYS_NET_PATH)
if os.path.islink(os.path.join(SYS_NET_PATH, i))
for name in output:
if (exclude_loopback and name == LOOPBACK_DEVNAME or
exclude_gre_devices and name in GRE_TUNNEL_DEVICE_NAMES):
retval.append(IPDevice(name, namespace=self.namespace))
return retval
def get_device_by_ip(self, ip):
"""Get the IPDevice from system which has ip configured.
@param ip: look for the device holding this ip. If this is None,
None is returned.
@type ip: str.
if not ip:
return None
addr = IpAddrCommand(self)
devices = addr.get_devices_with_ip(to=ip)
if devices:
return IPDevice(devices[0]['name'], namespace=self.namespace)
def add_tuntap(self, name, mode='tap'):
self._as_root([], 'tuntap', ('add', name, 'mode', mode))
return IPDevice(name, namespace=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
args += ['netns', namespace2]
self._as_root([], 'link', tuple(args))
return (IPDevice(name1, namespace=self.namespace),
IPDevice(name2, namespace=namespace2))
def add_macvtap(self, name, src_dev, mode='bridge'):
args = ['add', 'link', src_dev, 'name', name, 'type', 'macvtap',
'mode', mode]
self._as_root([], 'link', tuple(args))
return IPDevice(name, namespace=self.namespace)
def del_veth(self, name):
"""Delete a virtual interface between two namespaces."""
self._as_root([], 'link', ('del', name))
def add_dummy(self, name):
"""Create a Linux dummy interface with the given name."""
self._as_root([], 'link', ('add', name, 'type', 'dummy'))
return IPDevice(name, namespace=self.namespace)
def ensure_namespace(self, name):
if not self.netns.exists(name):
ip = self.netns.add(name)
lo = ip.device(LOOPBACK_DEVNAME)
ip = IPWrapper(namespace=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():
return True
return False
def add_device_to_namespace(self, device):
if self.namespace:
def add_vlan(self, name, physical_interface, vlan_id):
cmd = ['add', 'link', physical_interface, 'name', name,
'type', 'vlan', 'id', vlan_id]
self._as_root([], 'link', cmd)
return IPDevice(name, namespace=self.namespace)
def add_vxlan(self, name, vni, group=None, dev=None, ttl=None, tos=None,
local=None, port=None, proxy=False):
cmd = ['add', name, 'type', 'vxlan', 'id', vni]
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])
if proxy:
# tuple: min,max
if port and len(port) == 2:
cmd.extend(['port', port[0], port[1]])
elif port:
raise n_exc.NetworkVxlanPortRangeError(vxlan_range=port)
self._as_root([], 'link', cmd)
return (IPDevice(name, namespace=self.namespace))
def get_namespaces(cls):
output = cls._execute(
[], 'netns', ('list',),
return [l.split()[0] for l in output.splitlines()]
class IPDevice(SubProcessBase):
def __init__(self, name, namespace=None):
super(IPDevice, self).__init__(namespace=namespace)
self._name = name = IpLinkCommand(self)
self.addr = IpAddrCommand(self)
self.route = IpRouteCommand(self)
self.neigh = IpNeighCommand(self)
def __eq__(self, other):
return (other is not None and ==
and self.namespace == other.namespace)
def __str__(self):
def exists(self):
"""Return True if the device exists in the namespace."""
# we must save and restore this before returning
orig_log_fail_as_error = self.get_log_fail_as_error()
return bool(
except RuntimeError:
return False
def delete_addr_and_conntrack_state(self, cidr):
"""Delete an address along with its conntrack state
This terminates any active connections through an IP.
:param cidr: the IP address for which state should be removed.
This can be passed as a string with or without /NN.
A netaddr.IPAddress or netaddr.Network representing the IP address
can also be passed.
ip_str = str(netaddr.IPNetwork(cidr).ip)
ip_wrapper = IPWrapper(namespace=self.namespace)
# Delete conntrack state for ingress traffic
# If 0 flow entries have been deleted
# conntrack -D will return 1
ip_wrapper.netns.execute(["conntrack", "-D", "-d", ip_str],
except RuntimeError:
LOG.exception(_LE("Failed deleting ingress connection state of"
" floatingip %s"), ip_str)
# Delete conntrack state for egress traffic
ip_wrapper.netns.execute(["conntrack", "-D", "-q", ip_str],
except RuntimeError:
LOG.exception(_LE("Failed deleting egress connection state of"
" floatingip %s"), ip_str)
def _sysctl(self, cmd):
"""execute() doesn't return the exit status of the command it runs,
it returns stdout and stderr. Setting check_exit_code=True will cause
it to raise a RuntimeError if the exit status of the command is
non-zero, which in sysctl's case is an error. So we're normalizing
that into zero (success) and one (failure) here to mimic what
"echo $?" in a shell would be.
This is all because sysctl is too verbose and prints the value you
just set on success, unlike most other utilities that print nothing.
execute() will have dumped a message to the logs with the actual
output on failure, so it's not lost, and we don't need to print it
cmd = ['sysctl', '-w'] + cmd
ip_wrapper = IPWrapper(self.namespace)
ip_wrapper.netns.execute(cmd, run_as_root=True,
except RuntimeError:
LOG.exception(_LE("Failed running %s"), cmd)
return 1
return 0
def disable_ipv6(self):
sysctl_name = re.sub(r'\.', '/',
cmd = 'net.ipv6.conf.%s.disable_ipv6=1' % sysctl_name
return self._sysctl([cmd])
def name(self):
if self._name:
return self._name[:constants.DEVICE_NAME_MAX_LEN]
return self._name
def name(self, name):
self._name = name
class IpCommandBase(object):
def __init__(self, parent):
self._parent = parent
def _run(self, options, args):
return self._parent._run(options, self.COMMAND, args)
def _as_root(self, options, args, use_root_namespace=False):
return self._parent._as_root(options,
class IPRule(SubProcessBase):
def __init__(self, namespace=None):
super(IPRule, self).__init__(namespace=namespace)
self.rule = IpRuleCommand(self)
class IpRuleCommand(IpCommandBase):
COMMAND = 'rule'
def _make_canonical(ip_version, settings):
"""Converts settings to a canonical representation to compare easily"""
def canonicalize_fwmark_string(fwmark_mask):
"""Reformats fwmark/mask in to a canonical form
Examples, these are all equivalent:
(0x1, 0xfffffffff)
:param fwmark_mask: The firewall and mask (default 0xffffffff)
:type fwmark_mask: A string with / as delimiter, an iterable, or a
single value.
# Turn the value we were passed in to an iterable: fwmark[, mask]
if isinstance(fwmark_mask, six.string_types):
# A / separates the optional mask in a string
iterable = fwmark_mask.split('/')
iterable = iter(fwmark_mask)
except TypeError:
# At this point, it must be a single integer
iterable = [fwmark_mask]
def to_i(s):
if isinstance(s, six.string_types):
# Passing 0 as "base" arg to "int" causes it to determine
# the base automatically.
return int(s, 0)
# s isn't a string, can't specify base argument
return int(s)
integers = [to_i(x) for x in iterable]
# The default mask is all ones, the mask is 32 bits.
if len(integers) == 1:
# We now have two integers in a list. Convert to canonical string.
return '{0:#x}/{1:#x}'.format(*integers)
def canonicalize(item):
k, v = item
# ip rule shows these as 'any'
if k == 'from' and v == 'all':
return k, constants.IP_ANY[ip_version]
# lookup and table are interchangeable. Use table every time.
if k == 'lookup':
return 'table', v
if k == 'fwmark':
return k, canonicalize_fwmark_string(v)
return k, v
if 'type' not in settings:
settings['type'] = 'unicast'
return {k: str(v) for k, v in map(canonicalize, settings.items())}
def _parse_line(self, ip_version, line):
# Typical rules from 'ip rule show':
# 4030201: from lookup 10203040
# 1024: from all iif qg-c43b1928-48 lookup noscope
parts = line.split()
if not parts:
return {}
# Format of line is: "priority: <key> <value> ... [<type>]"
settings = {k: v for k, v in zip(parts[1::2], parts[2::2])}
settings['priority'] = parts[0][:-1]
if len(parts) % 2 == 0:
# When line has an even number of columns, last one is the type.
settings['type'] = parts[-1]
return self._make_canonical(ip_version, settings)
def list_rules(self, ip_version):
lines = self._as_root([ip_version], ['show']).splitlines()
return [self._parse_line(ip_version, line) for line in lines]
def _exists(self, ip_version, **kwargs):
return kwargs in self.list_rules(ip_version)
def _make__flat_args_tuple(self, *args, **kwargs):
for kwargs_item in sorted(kwargs.items(), key=lambda i: i[0]):
args += kwargs_item
return tuple(args)
def add(self, ip, **kwargs):
ip_version = get_ip_version(ip)
# In case if we need to add in a rule based on incoming
# interface we don't need to pass in the ip.
if not kwargs.get('iif'):
kwargs.update({'from': ip})
canonical_kwargs = self._make_canonical(ip_version, kwargs)
if not self._exists(ip_version, **canonical_kwargs):
args_tuple = self._make__flat_args_tuple('add', **canonical_kwargs)
self._as_root([ip_version], args_tuple)
def delete(self, ip, **kwargs):
ip_version = get_ip_version(ip)
# TODO(Carl) ip ignored in delete, okay in general?
canonical_kwargs = self._make_canonical(ip_version, kwargs)
args_tuple = self._make__flat_args_tuple('del', **canonical_kwargs)
self._as_root([ip_version], args_tuple)
class IpDeviceCommandBase(IpCommandBase):
def name(self):
class IpLinkCommand(IpDeviceCommandBase):
COMMAND = 'link'
def set_address(self, mac_address):
self._as_root([], ('set',, 'address', mac_address))
def set_allmulticast_on(self):
self._as_root([], ('set',, 'allmulticast', 'on'))
def set_mtu(self, mtu_size):
self._as_root([], ('set',, 'mtu', mtu_size))
def set_up(self):
return self._as_root([], ('set',, 'up'))
def set_down(self):
return self._as_root([], ('set',, 'down'))
def set_netns(self, namespace):
self._as_root([], ('set',, 'netns', namespace))
self._parent.namespace = namespace
def set_name(self, name):
self._as_root([], ('set',, 'name', name)) = name
def set_alias(self, alias_name):
self._as_root([], ('set',, 'alias', alias_name))
def delete(self):
self._as_root([], ('delete',
def address(self):
return self.attributes.get('link/ether')
def state(self):
return self.attributes.get('state')
def mtu(self):
return self.attributes.get('mtu')
def qdisc(self):
return self.attributes.get('qdisc')
def qlen(self):
return self.attributes.get('qlen')
def alias(self):
return self.attributes.get('alias')
def attributes(self):
return self._parse_line(self._run(['o'], ('show',
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, cidr, scope='global', add_broadcast=True):
net = netaddr.IPNetwork(cidr)
args = ['add', cidr,
'scope', scope,
if add_broadcast and net.version == 4:
args += ['brd', str(net[-1])]
self._as_root([net.version], tuple(args))
def delete(self, cidr):
ip_version = get_ip_version(cidr)
('del', cidr,
def flush(self, ip_version):
self._as_root([ip_version], ('flush',
def get_devices_with_ip(self, name=None, scope=None, to=None,
filters=None, ip_version=None):
"""Get a list of all the devices with an IP attached in the namespace.
@param name: if it's not None, only a device with that matching name
will be returned.
options = [ip_version] if ip_version else []
args = ['show']
if name:
args += [name]
if filters:
args += filters
if scope:
args += ['scope', scope]
if to:
args += ['to', to]
retval = []
for line in self._run(options, tuple(args)).split('\n'):
line = line.strip()
match =
if match:
# Found a match for a device name, but its' addresses will
# only appear in following lines, so we may as well continue.
device_name = remove_interface_suffix(
elif not line.startswith('inet'):
parts = line.split(" ")
if parts[0] == 'inet6':
scope = parts[3]
if parts[2] == 'brd':
scope = parts[5]
scope = parts[3]
dynamic=('dynamic' == parts[-1]),
tentative=('tentative' in line),
dadfailed=('dadfailed' == parts[-1])))
return retval
def list(self, scope=None, to=None, filters=None, ip_version=None):
"""Get device details of a device named <>."""
return self.get_devices_with_ip(, scope, to, filters, ip_version)
def wait_until_address_ready(self, address, wait_time=30):
"""Wait until an address is no longer marked 'tentative'
raises AddressNotReady if times out or address not present on interface
def is_address_ready():
addr_info = self.list(to=address)[0]
except IndexError:
raise AddressNotReady(
reason=_('Address not present on interface'))
if not addr_info['tentative']:
return True
if addr_info['dadfailed']:
raise AddressNotReady(
address=address, reason=_('Duplicate address detected'))
errmsg = _("Exceeded %s second limit waiting for "
"address to leave the tentative state.") % wait_time
is_address_ready, timeout=wait_time, sleep=0.20,
exception=AddressNotReady(address=address, reason=errmsg))
class IpRouteCommand(IpDeviceCommandBase):
COMMAND = 'route'
def __init__(self, parent, table=None):
super(IpRouteCommand, self).__init__(parent)
self._table = table
def table(self, table):
"""Return an instance of IpRouteCommand which works on given table"""
return IpRouteCommand(self._parent, table)
def _table_args(self, override=None):
if override:
return ['table', override]
return ['table', self._table] if self._table else []
def _dev_args(self):
return ['dev',] if else []
def add_gateway(self, gateway, metric=None, table=None):
ip_version = get_ip_version(gateway)
args = ['replace', 'default', 'via', gateway]
if metric:
args += ['metric', metric]
args += self._dev_args()
args += self._table_args(table)
self._as_root([ip_version], tuple(args))
def _run_as_root_detect_device_not_found(self, *args, **kwargs):
return self._as_root(*args, **kwargs)
except RuntimeError as rte:
with excutils.save_and_reraise_exception() as ctx:
if "Cannot find device" in str(rte):
ctx.reraise = False
raise exceptions.DeviceNotFoundError(
def delete_gateway(self, gateway, table=None):
ip_version = get_ip_version(gateway)
args = ['del', 'default',
'via', gateway]
args += self._dev_args()
args += self._table_args(table)
self._run_as_root_detect_device_not_found([ip_version], tuple(args))
def _parse_routes(self, ip_version, output, **kwargs):
for line in output.splitlines():
parts = line.split()
# Format of line is: "<cidr>|default [<key> <value>] ..."
route = {k: v for k, v in zip(parts[1::2], parts[2::2])}
route['cidr'] = parts[0]
# Avoids having to explicitly pass around the IP version
if route['cidr'] == 'default':
route['cidr'] = constants.IP_ANY[ip_version]
# ip route drops things like scope and dev from the output if it
# was specified as a filter. This allows us to add them back.
route['dev'] =
if self._table:
route['table'] = self._table
# Callers add any filters they use as kwargs
yield route
def list_routes(self, ip_version, **kwargs):
args = ['list']
args += self._dev_args()
args += self._table_args()
for k, v in kwargs.items():
args += [k, v]
output = self._run([ip_version], tuple(args))
return [r for r in self._parse_routes(ip_version, output, **kwargs)]
def list_onlink_routes(self, ip_version):
routes = self.list_routes(ip_version, scope='link')
return [r for r in routes if 'src' not in r]
def add_onlink_route(self, cidr):
self.add_route(cidr, scope='link')
def delete_onlink_route(self, cidr):
self.delete_route(cidr, scope='link')
def get_gateway(self, scope=None, filters=None, ip_version=None):
options = [ip_version] if ip_version else []
args = ['list']
args += self._dev_args()
args += self._table_args()
if filters:
args += filters
retval = None
if scope:
args += ['scope', scope]
route_list_lines = self._run(options, tuple(args)).split('\n')
default_route_line = next((x.strip() for x in
route_list_lines if
x.strip().startswith('default')), None)
if default_route_line:
retval = dict()
gateway =
if gateway:
metric =
if metric:
return retval
def flush(self, ip_version, table=None, **kwargs):
args = ['flush']
args += self._table_args(table)
for k, v in kwargs.items():
args += [k, v]
self._as_root([ip_version], tuple(args))
def add_route(self, cidr, via=None, table=None, **kwargs):
ip_version = get_ip_version(cidr)
args = ['replace', cidr]
if via:
args += ['via', via]
args += self._dev_args()
args += self._table_args(table)
for k, v in kwargs.items():
args += [k, v]
self._run_as_root_detect_device_not_found([ip_version], tuple(args))
def delete_route(self, cidr, via=None, table=None, **kwargs):
ip_version = get_ip_version(cidr)
args = ['del', cidr]
if via:
args += ['via', via]
args += self._dev_args()
args += self._table_args(table)
for k, v in kwargs.items():
args += [k, v]
self._run_as_root_detect_device_not_found([ip_version], tuple(args))
class IPRoute(SubProcessBase):
def __init__(self, namespace=None, table=None):
super(IPRoute, self).__init__(namespace=namespace) = None
self.route = IpRouteCommand(self, table=table)
class IpNeighCommand(IpDeviceCommandBase):
COMMAND = 'neigh'
def add(self, ip_address, mac_address):
ip_version = get_ip_version(ip_address)
('replace', ip_address,
'lladdr', mac_address,
'nud', 'permanent',
def delete(self, ip_address, mac_address):
ip_version = get_ip_version(ip_address)
('del', ip_address,
'lladdr', mac_address,
def show(self, ip_version):
options = [ip_version]
return self._as_root(options,
def flush(self, ip_version, ip_address):
"""Flush neighbour entries
Given address entry is removed from neighbour cache (ARP or NDP). To
flush all entries pass string 'all' as an address.
:param ip_version: Either 4 or 6 for IPv4 or IPv6 respectively
:param ip_address: The prefix selecting the neighbours to flush
self._as_root([ip_version], ('flush', 'to', ip_address))
class IpNetnsCommand(IpCommandBase):
COMMAND = 'netns'
def add(self, name):
self._as_root([], ('add', name), use_root_namespace=True)
wrapper = IPWrapper(namespace=name)
wrapper.netns.execute(['sysctl', '-w',
return wrapper
def delete(self, name):
self._as_root([], ('delete', name), use_root_namespace=True)
def execute(self, cmds, addl_env=None, check_exit_code=True,
log_fail_as_error=True, extra_ok_codes=None,
ns_params = []
kwargs = {'run_as_root': run_as_root}
if self._parent.namespace:
kwargs['run_as_root'] = True
ns_params = ['ip', 'netns', 'exec', self._parent.namespace]
env_params = []
if addl_env:
env_params = (['env'] +
['%s=%s' % pair for pair in addl_env.items()])
cmd = ns_params + env_params + list(cmds)
return utils.execute(cmd, check_exit_code=check_exit_code,
log_fail_as_error=log_fail_as_error, **kwargs)
def exists(self, name):
output = self._parent._execute(
['o'], 'netns', ['list'],
for line in [l.split()[0] for l in output.splitlines()]:
if name == line:
return True
return False
def vlan_in_use(segmentation_id, namespace=None):
"""Return True if VLAN ID is in use by an interface, else False."""
ip_wrapper = IPWrapper(namespace=namespace)
interfaces = ip_wrapper.netns.execute(["ip", "-d", "link", "list"],
return '802.1Q id %s ' % segmentation_id in interfaces
def vxlan_in_use(segmentation_id, namespace=None):
"""Return True if VXLAN VNID is in use by an interface, else False."""
ip_wrapper = IPWrapper(namespace=namespace)
interfaces = ip_wrapper.netns.execute(["ip", "-d", "link", "list"],
return 'vxlan id %s ' % segmentation_id in interfaces
def device_exists(device_name, namespace=None):
"""Return True if the device exists in the namespace."""
return IPDevice(device_name, namespace=namespace).exists()
def device_exists_with_ips_and_mac(device_name, ip_cidrs, mac, namespace=None):
"""Return True if the device with the given IP addresses and MAC address
exists in the namespace.
device = IPDevice(device_name, namespace=namespace)
if mac !=
return False
device_ip_cidrs = [ip['cidr'] for ip in device.addr.list()]
for ip_cidr in ip_cidrs:
if ip_cidr not in device_ip_cidrs:
return False
except RuntimeError:
return False
return True
'via': 'nexthop',
'dev': 'device',
'scope': 'scope'
def _parse_ip_route_line(line):
"""Parse a line output from ip route.
Example for output from 'ip route':
default via dev wlp3s0 proto static metric 1024 dev tun0 proto static scope link metric 1024 dev tun1 proto static scope link metric 1024 linkdown
The first column is the destination, followed by key/value pairs and flags.
@param line A line output from ip route
@return: a dictionary representing a route.
line = line.split()
result = {
'destination': line[0],
'nexthop': None,
'device': None,
'scope': None
idx = 1
while idx < len(line):
field = _IP_ROUTE_PARSE_KEYS.get(line[idx])
if not field:
idx = idx + 1
result[field] = line[idx + 1]
idx = idx + 2
return result
def get_routing_table(ip_version, namespace=None):
"""Return a list of dictionaries, each representing a route.
@param ip_version: the routes of version to return, for example 4
@param namespace
@return: a list of dictionaries, each representing a route.
The dictionary format is: {'destination': cidr,
'nexthop': ip,
'device': device_name,
'scope': scope}
ip_wrapper = IPWrapper(namespace=namespace)
table = ip_wrapper.netns.execute(
['ip', '-%s' % ip_version, 'route'],
return [_parse_ip_route_line(line)
for line in table.split('\n') if line.strip()]
def ensure_device_is_ready(device_name, namespace=None):
dev = IPDevice(device_name, namespace=namespace)
# Ensure the device is up, even if it is already up. If the device
# doesn't exist, a RuntimeError will be raised.
except RuntimeError:
return False
return True
def iproute_arg_supported(command, arg):
command += ['help']
stdout, stderr = utils.execute(command, check_exit_code=False,
return_stderr=True, log_fail_as_error=False)
return any(arg in line for line in stderr.split('\n'))
def _arping(ns_name, iface_name, address, count, log_exception):
# Pass -w to set timeout to ensure exit if interface removed while running
arping_cmd = ['arping', '-A', '-I', iface_name, '-c', count,
'-w', 1.5 * count, address]
ip_wrapper = IPWrapper(namespace=ns_name)
# Since arping is used to send gratuitous ARP, a response is not
# expected. In some cases (no response) and with some platforms
# (>=Ubuntu 14.04), arping exit code can be 1.
ip_wrapper.netns.execute(arping_cmd, extra_ok_codes=[1])
except Exception as exc:
msg = _("Failed sending gratuitous ARP "
"to %(addr)s on %(iface)s in namespace %(ns)s: %(err)s")
logger_method = LOG.exception
if not log_exception:
logger_method = LOG.warning
logger_method(msg, {'addr': address,
'iface': iface_name,
'ns': ns_name,
'err': exc})
def send_ip_addr_adv_notif(
ns_name, iface_name, address, config, log_exception=True):
"""Send advance notification of an IP address assignment.
If the address is in the IPv4 family, send gratuitous ARP.
If the address is in the IPv6 family, no advance notification is
necessary, since the Neighbor Discovery Protocol (NDP), Duplicate
Address Discovery (DAD), and (for stateless addresses) router
advertisements (RAs) are sufficient for address resolution and
duplicate address detection.
:param ns_name: Namespace name which GARPs are gonna be sent from.
:param iface_name: Name of interface which GARPs are gonna be sent from.
:param address: Advertised IP address.
:param config: An object with send_arp_for_ha member, about
how many GARPs are gonna be sent.
:param log_exception: (Optional) True if possible failures should be logged
on exception level. Otherwise they are logged on
WARNING level. Default is True.
count = config.send_arp_for_ha
def arping():
_arping(ns_name, iface_name, address, count, log_exception)
if count > 0 and netaddr.IPAddress(address).version == 4:
def add_namespace_to_cmd(cmd, namespace=None):
"""Add an optional namespace to the command."""
return ['ip', 'netns', 'exec', namespace] + cmd if namespace else cmd
def get_ip_version(ip_or_cidr):
return netaddr.IPNetwork(ip_or_cidr).version
def get_ipv6_lladdr(mac_addr):
return '%s/64' % netaddr.EUI(mac_addr).ipv6_link_local()
def get_ip_nonlocal_bind(namespace=None):
"""Get kernel option value of ip_nonlocal_bind in given namespace."""
cmd = ['sysctl', '-bn', IP_NONLOCAL_BIND]
ip_wrapper = IPWrapper(namespace)
return int(ip_wrapper.netns.execute(cmd, run_as_root=True))
def set_ip_nonlocal_bind(value, namespace=None, log_fail_as_error=True):
"""Set sysctl knob of ip_nonlocal_bind to given value."""
cmd = ['sysctl', '-w', '%s=%d' % (IP_NONLOCAL_BIND, value)]
ip_wrapper = IPWrapper(namespace)
cmd, run_as_root=True, log_fail_as_error=log_fail_as_error)
def set_ip_nonlocal_bind_for_namespace(namespace):
"""Set ip_nonlocal_bind but don't raise exception on failure."""
value=0, namespace=namespace, log_fail_as_error=False)
except RuntimeError as rte:
_LW("Setting %(knob)s=0 in namespace %(ns)s failed: %(err)s. It "
"will not be set to 0 in the root namespace in order to not "
"break DVR, which requires this value be set to 1. This "
"may introduce a race between moving a floating IP to a "
"different network node, and the peer side getting a "
"populated ARP cache for a given floating IP address."),
'ns': namespace,
'err': rte})