openstack/neutron
Code Issues Proposed changes

replaces enumeration method used to get a list of interfaces

Browse Source 
ip_lib was parsing tunnel links incorrectly. We can create interface
names with any character the filesystem supports (not '..', '/', ':').
Given this we do not know what to delimit on so parsing iproute2 output
is probably not a good idea.

I asked the iproute2 devs what the proper way we should get interface
names is and was told NOT to parse iproute2 output but to use something
like sysfs instead.  http://www.spinics.net/lists/netdev/msg316577.html

This patch pulls interfaces from sysfs (/sys/class/net) and verifies them
via checking if they are links (bonding creates files for instance and
needs to be skipped).

Currently it is not possible without jumping through a ton of hoops to
access a network namespace without iproute2 or cython, so we use ip to
run find to find the correct sysfs directory.  We also only call out to
iproute2 _ONLY_ if needed.

Change-Id: I07d1d297f07857d216649cccf717896574aac301
Closes-Bug: 1374663
This commit is contained in:
Matthew Thode 2015-02-09 11:02:58 -06:00
parent 0244e59df0
commit c717a6365c
7 changed files with 45 additions and 60 deletions
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1
etc/neutron/rootwrap.d/cisco-apic.filters
View File

@ -13,4 +13,5 @@ lldpctl: CommandFilter, lldpctl, root
# ip_lib filters
ip: IpFilter, ip, root
find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -printf, %.*
ip_exec: IpNetnsExecFilter, ip, root

1
etc/neutron/rootwrap.d/dhcp.filters
View File

@ -32,4 +32,5 @@ kill_metadata7: KillFilter, root, python2.7, -9
# ip_lib
ip: IpFilter, ip, root
find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -printf, %.*
ip_exec: IpNetnsExecFilter, ip, root

1
etc/neutron/rootwrap.d/l3.filters
View File

@ -29,6 +29,7 @@ kill_radvd: KillFilter, root, /sbin/radvd, -9, -HUP
# ip_lib
ip: IpFilter, ip, root
find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -printf, %.*
ip_exec: IpNetnsExecFilter, ip, root
# For ip monitor

1
etc/neutron/rootwrap.d/linuxbridge-plugin.filters
View File

@ -16,4 +16,5 @@ bridge: CommandFilter, bridge, root
# ip_lib
ip: IpFilter, ip, root
find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -printf, %.*
ip_exec: IpNetnsExecFilter, ip, root

1
etc/neutron/rootwrap.d/openvswitch-plugin.filters
View File

@ -19,4 +19,5 @@ xe: CommandFilter, xe, root
# ip_lib
ip: IpFilter, ip, root
find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -printf, %.*
ip_exec: IpNetnsExecFilter, ip, root

41
neutron/agent/linux/ip_lib.py
View File

@ -15,6 +15,7 @@
import eventlet
import netaddr
import os
from oslo_config import cfg
from oslo_log import log as logging
@ -32,11 +33,8 @@ OPTS = [
LOOPBACK_DEVNAME = 'lo'
# NOTE(ethuleau): depend of the version of iproute2, the vlan
# interface details vary.
VLAN_INTERFACE_DETAIL = ['vlan protocol 802.1q',
'vlan protocol 802.1Q',
'vlan id']
SYS_NET_PATH = '/sys/class/net'
class SubProcessBase(object):
@ -93,22 +91,27 @@ class IPWrapper(SubProcessBase):
def get_devices(self, exclude_loopback=False):
retval = []
output = self._run(['o', 'd'], 'link', ('list',))
for line in output.split('\n'):
if '<' not in line:
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).
output = utils.execute(['ip', 'netns', 'exec', self.namespace,
'find', SYS_NET_PATH, '-maxdepth', '1',
'-type', 'l', '-printf', '%f '],
run_as_root=True,
log_fail_as_error=self.log_fail_as_error
).split()
else:
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:
continue
tokens = line.split(' ', 2)
if len(tokens) == 3:
if any(v in tokens[2] for v in VLAN_INTERFACE_DETAIL):
delimiter = '@'
else:
delimiter = ':'
name = tokens[1].rpartition(delimiter)[0].strip()
retval.append(IPDevice(name, namespace=self.namespace))
if exclude_loopback and name == LOOPBACK_DEVNAME:
continue
retval.append(IPDevice(name, namespace=self.namespace))
return retval
def add_tuntap(self, name, mode='tap'):

59
neutron/tests/unit/test_linux_ip_lib.py
View File

@ -17,6 +17,7 @@ import mock
import netaddr
from neutron.agent.linux import ip_lib
from neutron.agent.linux import utils # noqa
from neutron.common import exceptions
from neutron.tests import base
@ -235,49 +236,25 @@ class TestIpWrapper(base.BaseTestCase):
self.execute_p = mock.patch.object(ip_lib.IPWrapper, '_execute')
self.execute = self.execute_p.start()
def test_get_devices(self):
self.execute.return_value = '\n'.join(LINK_SAMPLE)
@mock.patch('os.path.islink')
@mock.patch('os.listdir', return_value=['lo'])
def test_get_devices(self, mocked_listdir, mocked_islink):
retval = ip_lib.IPWrapper().get_devices()
self.assertEqual(retval,
[ip_lib.IPDevice('lo'),
ip_lib.IPDevice('eth0'),
ip_lib.IPDevice('br-int'),
ip_lib.IPDevice('gw-ddc717df-49'),
ip_lib.IPDevice('foo:foo'),
ip_lib.IPDevice('foo@foo'),
ip_lib.IPDevice('foo:foo@foo'),
ip_lib.IPDevice('foo@foo:foo'),
ip_lib.IPDevice('bar.9'),
ip_lib.IPDevice('bar'),
ip_lib.IPDevice('bar:bar'),
ip_lib.IPDevice('bar@bar'),
ip_lib.IPDevice('bar:bar@bar'),
ip_lib.IPDevice('bar@bar:bar')])
mocked_islink.assert_called_once_with('/sys/class/net/lo')
self.assertEqual(retval, [ip_lib.IPDevice('lo')])
self.execute.assert_called_once_with(['o', 'd'], 'link', ('list',),
log_fail_as_error=True)
def test_get_devices_malformed_line(self):
self.execute.return_value = '\n'.join(LINK_SAMPLE + ['gibberish'])
retval = ip_lib.IPWrapper().get_devices()
self.assertEqual(retval,
[ip_lib.IPDevice('lo'),
ip_lib.IPDevice('eth0'),
ip_lib.IPDevice('br-int'),
ip_lib.IPDevice('gw-ddc717df-49'),
ip_lib.IPDevice('foo:foo'),
ip_lib.IPDevice('foo@foo'),
ip_lib.IPDevice('foo:foo@foo'),
ip_lib.IPDevice('foo@foo:foo'),
ip_lib.IPDevice('bar.9'),
ip_lib.IPDevice('bar'),
ip_lib.IPDevice('bar:bar'),
ip_lib.IPDevice('bar@bar'),
ip_lib.IPDevice('bar:bar@bar'),
ip_lib.IPDevice('bar@bar:bar')])
self.execute.assert_called_once_with(['o', 'd'], 'link', ('list',),
log_fail_as_error=True)
@mock.patch('neutron.agent.linux.utils.execute')
def test_get_devices_namespaces(self, mocked_execute):
fake_str = mock.Mock()
fake_str.split.return_value = ['lo']
mocked_execute.return_value = fake_str
retval = ip_lib.IPWrapper(namespace='foo').get_devices()
mocked_execute.assert_called_once_with(
['ip', 'netns', 'exec', 'foo', 'find', '/sys/class/net',
'-maxdepth', '1', '-type', 'l', '-printf', '%f '],
run_as_root=True, log_fail_as_error=True)
self.assertTrue(fake_str.split.called)
self.assertEqual(retval, [ip_lib.IPDevice('lo', namespace='foo')])
def test_get_namespaces(self):
self.execute.return_value = '\n'.join(NETNS_SAMPLE)