OpenStack Networking (Neutron)
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#
# 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 re
import eventlet
import netaddr
from neutron_lib import constants
from neutron_lib import exceptions
from oslo_concurrency import lockutils
from oslo_log import log as logging
from neutron.agent.linux import utils as linux_utils
LOG = logging.getLogger(__name__)
CONTRACK_MGRS = {}
MAX_CONNTRACK_ZONES = 65535
ZONE_START = 4097
WORKERS = 8
class IpConntrackUpdate(object):
"""Encapsulates a conntrack update
An instance of this object carries the information necessary to
process a request to update the conntrack table.
"""
def __init__(self, device_info_list, rule, remote_ips):
self.device_info_list = device_info_list
self.rule = rule
self.remote_ips = remote_ips
def __repr__(self):
return ('<IpConntrackUpdate(device_info_list=%s, rule=%s, '
'remote_ips=%s>' % (self.device_info_list, self.rule,
self.remote_ips))
@lockutils.synchronized('conntrack')
def get_conntrack(get_rules_for_table_func, filtered_ports, unfiltered_ports,
execute=None, namespace=None, zone_per_port=False):
try:
return CONTRACK_MGRS[namespace]
except KeyError:
ipconntrack = IpConntrackManager(get_rules_for_table_func,
filtered_ports, unfiltered_ports,
execute, namespace, zone_per_port)
CONTRACK_MGRS[namespace] = ipconntrack
return CONTRACK_MGRS[namespace]
class IpConntrackManager(object):
"""Smart wrapper for ip conntrack."""
def __init__(self, get_rules_for_table_func, filtered_ports,
unfiltered_ports, execute=None, namespace=None,
zone_per_port=False):
self.get_rules_for_table_func = get_rules_for_table_func
self.execute = execute or linux_utils.execute
self.namespace = namespace
self.filtered_ports = filtered_ports
self.unfiltered_ports = unfiltered_ports
self.zone_per_port = zone_per_port # zone per port vs per network
self._populate_initial_zone_map()
self._queue = eventlet.queue.LightQueue()
self._start_process_queue()
def _start_process_queue(self):
LOG.debug("Starting ip_conntrack _process_queue_worker() threads")
pool = eventlet.GreenPool(size=WORKERS)
for i in range(WORKERS):
pool.spawn_n(self._process_queue_worker)
def _process_queue_worker(self):
# While it's technically not necessary to have this method, the
# 'while True' could just be in _process_queue(), the tests have
# to be able to drain the queue without blocking, so _process_queue()
# is made standalone.
while True:
self._process_queue()
def _process_queue(self):
update = None
try:
# this will block until an entry gets added to the queue
update = self._queue.get()
if update.remote_ips:
for remote_ip in update.remote_ips:
self._delete_conntrack_state(
update.device_info_list, update.rule, remote_ip)
else:
self._delete_conntrack_state(
update.device_info_list, update.rule)
except Exception:
LOG.exception("Failed to process ip_conntrack queue entry: %s",
update)
def _process(self, device_info_list, rule, remote_ips=None):
# queue the update to allow the caller to resume its work
update = IpConntrackUpdate(device_info_list, rule, remote_ips)
self._queue.put(update)
@staticmethod
def _generate_conntrack_cmd_by_rule(rule, namespace):
ethertype = rule.get('ethertype')
protocol = rule.get('protocol')
direction = rule.get('direction')
mark = rule.get('mark')
cmd = ['conntrack', '-D']
if protocol is not None:
# 0 is IP in /etc/protocols, but conntrack will throw an error
if str(protocol) == '0':
protocol = 'ip'
cmd.extend(['-p', str(protocol)])
cmd.extend(['-f', str(ethertype).lower()])
if mark is not None:
cmd.extend(['-m', str(mark)])
cmd.append('-d' if direction == 'ingress' else '-s')
cmd_ns = []
if namespace:
cmd_ns.extend(['ip', 'netns', 'exec', namespace])
cmd_ns.extend(cmd)
return cmd_ns
def _get_conntrack_cmds(self, device_info_list, rule, remote_ip=None):
conntrack_cmds = set()
cmd = self._generate_conntrack_cmd_by_rule(rule, self.namespace)
ethertype = rule.get('ethertype')
for device_info in device_info_list:
zone_id = self.get_device_zone(device_info, create=False)
if not zone_id:
LOG.debug("No zone for device %(dev)s. Will not try to "
"clear conntrack state. Zone map: %(zm)s",
{'dev': device_info['device'],
'zm': self._device_zone_map})
continue
ips = device_info.get('fixed_ips', [])
for ip in ips:
net = netaddr.IPNetwork(ip)
if str(net.version) not in ethertype:
continue
ip_cmd = [str(net.ip), '-w', zone_id]
if remote_ip and str(
netaddr.IPNetwork(remote_ip).version) in ethertype:
if rule.get('direction') == 'ingress':
direction = '-s'
else:
direction = '-d'
ip_cmd.extend([direction, str(remote_ip)])
conntrack_cmds.add(tuple(cmd + ip_cmd))
return conntrack_cmds
def _delete_conntrack_state(self, device_info_list, rule, remote_ip=None):
conntrack_cmds = self._get_conntrack_cmds(device_info_list,
rule, remote_ip)
for cmd in conntrack_cmds:
try:
self.execute(list(cmd), run_as_root=True,
check_exit_code=True,
extra_ok_codes=[1])
except RuntimeError:
LOG.exception("Failed execute conntrack command %s", cmd)
def delete_conntrack_state_by_rule(self, device_info_list, rule):
self._process(device_info_list, rule)
def delete_conntrack_state_by_remote_ips(self, device_info_list,
ethertype, remote_ips, mark=None):
for direction in ['ingress', 'egress']:
rule = {'ethertype': str(ethertype).lower(),
'direction': direction}
if mark:
rule['mark'] = mark
self._process(device_info_list, rule, remote_ips)
def _populate_initial_zone_map(self):
"""Setup the map between devices and zones based on current rules."""
self._device_zone_map = {}
rules = self.get_rules_for_table_func('raw')
for rule in rules:
match = re.match(r'.* --physdev-in (?P<dev>[a-zA-Z0-9\-]+)'
r'.* -j CT --zone (?P<zone>\d+).*', rule)
if match:
# strip off any prefix that the interface is using
short_port_id = (
match.group('dev')[constants.LINUX_DEV_PREFIX_LEN:])
self._device_zone_map[short_port_id] = int(match.group('zone'))
LOG.debug("Populated conntrack zone map: %s", self._device_zone_map)
def _device_key(self, port):
# we have to key the device_zone_map based on the fragment of the
# UUID that shows up in the interface name. This is because the initial
# map is populated strictly based on interface names that we don't know
# the full UUID of.
if self.zone_per_port:
identifier = port['device'][constants.LINUX_DEV_PREFIX_LEN:]
else:
identifier = port['network_id']
return identifier[:(constants.LINUX_DEV_LEN -
constants.LINUX_DEV_PREFIX_LEN)]
def get_device_zone(self, port, create=True):
device_key = self._device_key(port)
try:
return self._device_zone_map[device_key]
except KeyError:
if create:
return self._generate_device_zone(device_key)
def _free_zones_from_removed_ports(self):
"""Clears any entries from the zone map of removed ports."""
existing_ports = [
self._device_key(port)
for port in (list(self.filtered_ports.values()) +
list(self.unfiltered_ports.values()))
]
removed = set(self._device_zone_map) - set(existing_ports)
for dev in removed:
self._device_zone_map.pop(dev, None)
def _generate_device_zone(self, short_device_id):
"""Generates a unique conntrack zone for the passed in ID."""
try:
zone = self._find_open_zone()
except exceptions.CTZoneExhaustedError:
# Free some zones and try again, repeat failure will not be caught
self._free_zones_from_removed_ports()
zone = self._find_open_zone()
self._device_zone_map[short_device_id] = zone
LOG.debug("Assigned CT zone %(z)s to device %(dev)s.",
{'z': zone, 'dev': short_device_id})
return self._device_zone_map[short_device_id]
def _find_open_zone(self):
# call set to dedup because old ports may be mapped to the same zone.
zones_in_use = sorted(set(self._device_zone_map.values()))
if not zones_in_use:
return ZONE_START
# attempt to increment onto the highest used zone first. if we hit the
# end, go back and look for any gaps left by removed devices.
last = zones_in_use[-1]
if last < MAX_CONNTRACK_ZONES:
return max(last + 1, ZONE_START)
for index, used in enumerate(zones_in_use):
if used - index != ZONE_START:
# gap found, let's use it!
return index + ZONE_START
# conntrack zones exhausted :( :(
raise exceptions.CTZoneExhaustedError()
class OvsIpConntrackManager(IpConntrackManager):
def __init__(self, execute=None):
super(OvsIpConntrackManager, self).__init__(
get_rules_for_table_func=None,
filtered_ports={}, unfiltered_ports={},
execute=execute, namespace=None, zone_per_port=False)
def _populate_initial_zone_map(self):
self._device_zone_map = {}
def get_device_zone(self, port, create=False):
of_port = port.get('of_port')
if of_port is None:
return
return of_port.vlan_tag