neutron/neutron/privileged/agent/linux/ip_lib.py

69 lines
2.4 KiB
Python

# 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 errno
import socket
import pyroute2
from pyroute2.netlink import rtnl
from neutron._i18n import _
from neutron import privileged
_IP_VERSION_FAMILY_MAP = {4: socket.AF_INET, 6: socket.AF_INET6}
def _get_scope_name(scope):
"""Return the name of the scope (given as a number), or the scope number
if the name is unknown.
"""
return rtnl.rt_scope.get(scope, scope)
class NetworkNamespaceNotFound(RuntimeError):
message = _("Network namespace %(netns_name)s could not be found.")
def __init__(self, netns_name):
super(NetworkNamespaceNotFound, self).__init__(
self.message % {'netns_name': netns_name})
@privileged.default.entrypoint
def get_routing_table(ip_version, namespace=None):
"""Return a list of dictionaries, each representing a route.
:param ip_version: IP version of routes to return, for example 4
:param namespace: The name of the namespace from which to get the routes
:return: a list of dictionaries, each representing a route.
The dictionary format is: {'destination': cidr,
'nexthop': ip,
'device': device_name,
'scope': scope}
"""
family = _IP_VERSION_FAMILY_MAP[ip_version]
try:
netns = pyroute2.NetNS(namespace, flags=0) if namespace else None
except OSError as e:
if e.errno == errno.ENOENT:
raise NetworkNamespaceNotFound(netns_name=namespace)
raise
with pyroute2.IPDB(nl=netns) as ipdb:
ipdb_routes = ipdb.routes
ipdb_interfaces = ipdb.interfaces
routes = [{'destination': route['dst'],
'nexthop': route.get('gateway'),
'device': ipdb_interfaces[route['oif']]['ifname'],
'scope': _get_scope_name(route['scope'])}
for route in ipdb_routes if route['family'] == family]
return routes