OpenStack Networking (Neutron)
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# Copyright (c) 2015 OpenStack Foundation
#
# 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 neutron_lib import constants as lib_constants
from oslo_log import log as logging
from neutron.agent.l3 import dvr_local_router
from neutron.agent.l3 import dvr_snat_ns
from neutron.agent.l3 import router_info as router
from neutron.agent.linux import ip_lib
from neutron.agent.linux import iptables_manager
from neutron.common import utils as common_utils
LOG = logging.getLogger(__name__)
class DvrEdgeRouter(dvr_local_router.DvrLocalRouter):
def __init__(self, host, *args, **kwargs):
super(DvrEdgeRouter, self).__init__(host, *args, **kwargs)
self.snat_namespace = dvr_snat_ns.SnatNamespace(
self.router_id, self.agent_conf, self.driver, self.use_ipv6)
self.snat_iptables_manager = None
def get_gw_ns_name(self):
return self.snat_namespace.name
def external_gateway_added(self, ex_gw_port, interface_name):
super(DvrEdgeRouter, self).external_gateway_added(
ex_gw_port, interface_name)
if self._is_this_snat_host():
self._create_dvr_gateway(ex_gw_port, interface_name)
# NOTE: When a router is created without a gateway the routes get
# added to the router namespace, but if we wanted to populate
# the same routes to the snat namespace after the gateway port
# is added, we need to call routes_updated here.
self.routes_updated([], self.router['routes'])
elif self.snat_namespace.exists():
# This is the case where the snat was moved manually or
# rescheduled to a different agent when the agent was dead.
LOG.debug("SNAT was moved or rescheduled to a different host "
"and does not match with the current host. This is "
"a stale namespace %s and will be cleared from the "
"current dvr_snat host.", self.snat_namespace.name)
self.external_gateway_removed(ex_gw_port, interface_name)
def _list_centralized_floating_ip_cidrs(self):
# Compute a list of addresses this gw is supposed to have.
# This avoids unnecessarily removing those addresses and
# causing a momentarily network outage.
floating_ips = self.get_floating_ips()
return [common_utils.ip_to_cidr(ip['floating_ip_address'])
for ip in floating_ips
if ip.get(lib_constants.DVR_SNAT_BOUND)]
def external_gateway_updated(self, ex_gw_port, interface_name):
if not self._is_this_snat_host():
# no centralized SNAT gateway for this node/agent
LOG.debug("not hosting snat for router: %s", self.router['id'])
if self.snat_namespace.exists():
LOG.debug("SNAT was rescheduled to host %s. Clearing snat "
"namespace.", self.router.get('gw_port_host'))
return self.external_gateway_removed(
ex_gw_port, interface_name)
return
if not self.snat_namespace.exists():
# SNAT might be rescheduled to this agent; need to process like
# newly created gateway
return self.external_gateway_added(ex_gw_port, interface_name)
else:
preserve_ips = self._list_centralized_floating_ip_cidrs()
self._external_gateway_added(ex_gw_port,
interface_name,
self.snat_namespace.name,
preserve_ips)
def _external_gateway_removed(self, ex_gw_port, interface_name):
super(DvrEdgeRouter, self).external_gateway_removed(ex_gw_port,
interface_name)
if not self._is_this_snat_host() and not self.snat_namespace.exists():
# no centralized SNAT gateway for this node/agent
LOG.debug("not hosting snat for router: %s", self.router['id'])
return
self.driver.unplug(interface_name,
namespace=self.snat_namespace.name,
prefix=router.EXTERNAL_DEV_PREFIX)
def external_gateway_removed(self, ex_gw_port, interface_name):
self._external_gateway_removed(ex_gw_port, interface_name)
if self.snat_namespace.exists():
self.snat_namespace.delete()
def internal_network_added(self, port):
super(DvrEdgeRouter, self).internal_network_added(port)
# TODO(gsagie) some of this checks are already implemented
# in the base class, think how to avoid re-doing them
if not self._is_this_snat_host():
return
sn_port = self.get_snat_port_for_internal_port(port)
if not sn_port:
return
ns_name = dvr_snat_ns.SnatNamespace.get_snat_ns_name(self.router['id'])
interface_name = self._get_snat_int_device_name(sn_port['id'])
self._internal_network_added(
ns_name,
sn_port['network_id'],
sn_port['id'],
sn_port['fixed_ips'],
sn_port['mac_address'],
interface_name,
lib_constants.SNAT_INT_DEV_PREFIX,
mtu=sn_port.get('mtu'))
def _dvr_internal_network_removed(self, port):
super(DvrEdgeRouter, self)._dvr_internal_network_removed(port)
if not self.ex_gw_port:
return
sn_port = self.get_snat_port_for_internal_port(port, self.snat_ports)
if not sn_port:
return
if not self._is_this_snat_host():
return
snat_interface = self._get_snat_int_device_name(sn_port['id'])
ns_name = self.snat_namespace.name
prefix = lib_constants.SNAT_INT_DEV_PREFIX
if ip_lib.device_exists(snat_interface, namespace=ns_name):
self.driver.unplug(snat_interface, namespace=ns_name,
prefix=prefix)
def _plug_snat_port(self, port):
interface_name = self._get_snat_int_device_name(port['id'])
self._internal_network_added(
self.snat_namespace.name, port['network_id'],
port['id'], port['fixed_ips'],
port['mac_address'], interface_name,
lib_constants.SNAT_INT_DEV_PREFIX,
mtu=port.get('mtu'))
def _create_dvr_gateway(self, ex_gw_port, gw_interface_name):
snat_ns = self._create_snat_namespace()
# connect snat_ports to br_int from SNAT namespace
for port in self.get_snat_interfaces():
self._plug_snat_port(port)
self._external_gateway_added(ex_gw_port, gw_interface_name,
snat_ns.name, preserve_ips=[])
self.snat_iptables_manager = iptables_manager.IptablesManager(
namespace=snat_ns.name,
use_ipv6=self.use_ipv6)
self._initialize_address_scope_iptables(self.snat_iptables_manager)
def _create_snat_namespace(self):
"""Create SNAT namespace."""
# TODO(mlavalle): in the near future, this method should contain the
# code in the L3 agent that creates a gateway for a dvr. The first step
# is to move the creation of the snat namespace here
self.snat_namespace.create()
return self.snat_namespace
def _get_snat_int_device_name(self, port_id):
long_name = lib_constants.SNAT_INT_DEV_PREFIX + port_id
return long_name[:self.driver.DEV_NAME_LEN]
def _is_this_snat_host(self):
host = self.router.get('gw_port_host')
if not host:
LOG.debug("gw_port_host missing from router: %s",
self.router['id'])
return host == self.host
def _handle_router_snat_rules(self, ex_gw_port, interface_name):
super(DvrEdgeRouter, self)._handle_router_snat_rules(
ex_gw_port, interface_name)
if not self._is_this_snat_host():
return
if not self.get_ex_gw_port():
return
if not self.snat_iptables_manager:
LOG.debug("DVR router: no snat rules to be handled")
return
with self.snat_iptables_manager.defer_apply():
self._empty_snat_chains(self.snat_iptables_manager)
# NOTE: float-snat should be added for the
# centralized floating-ips supported by the
# snat namespace.
self.snat_iptables_manager.ipv4['nat'].add_rule(
'snat', '-j $float-snat')
self._add_snat_rules(ex_gw_port, self.snat_iptables_manager,
interface_name)
def update_routing_table(self, operation, route):
if self.get_ex_gw_port() and self._is_this_snat_host():
ns_name = self.snat_namespace.name
# NOTE: For now let us apply the static routes both in SNAT
# namespace and Router Namespace, to reduce the complexity.
if self.snat_namespace.exists():
super(DvrEdgeRouter, self)._update_routing_table(
operation, route, namespace=ns_name)
else:
LOG.error("The SNAT namespace %s does not exist for "
"the router.", ns_name)
super(DvrEdgeRouter, self).update_routing_table(operation, route)
def delete(self):
super(DvrEdgeRouter, self).delete()
if self.snat_namespace.exists():
self.snat_namespace.delete()
def process_address_scope(self):
super(DvrEdgeRouter, self).process_address_scope()
if not self._is_this_snat_host():
return
if not self.snat_iptables_manager:
LOG.debug("DVR router: no snat rules to be handled")
return
# Prepare address scope iptables rule for dvr snat interfaces
internal_ports = self.get_snat_interfaces()
ports_scopemark = self._get_port_devicename_scopemark(
internal_ports, self._get_snat_int_device_name)
# Prepare address scope iptables rule for external port
external_port = self.get_ex_gw_port()
if external_port:
external_port_scopemark = self._get_port_devicename_scopemark(
[external_port], self.get_external_device_name)
for ip_version in (lib_constants.IP_VERSION_4,
lib_constants.IP_VERSION_6):
ports_scopemark[ip_version].update(
external_port_scopemark[ip_version])
with self.snat_iptables_manager.defer_apply():
self._add_address_scope_mark(
self.snat_iptables_manager, ports_scopemark)
def _delete_stale_external_devices(self, interface_name):
if not self.snat_namespace.exists():
return
ns_ip = ip_lib.IPWrapper(namespace=self.snat_namespace.name)
for d in ns_ip.get_devices():
if (d.name.startswith(router.EXTERNAL_DEV_PREFIX) and
d.name != interface_name):
LOG.debug('Deleting stale external router device: %s', d.name)
self.driver.unplug(
d.name,
namespace=self.snat_namespace.name,
prefix=router.EXTERNAL_DEV_PREFIX)
def get_snat_external_device_interface_name(self, ex_gw_port):
long_name = router.EXTERNAL_DEV_PREFIX + ex_gw_port['id']
return long_name[:self.driver.DEV_NAME_LEN]
def get_centralized_fip_cidr_set(self):
"""Returns the fip_cidr set for centralized floatingips."""
ex_gw_port = self.get_ex_gw_port()
# Don't look for centralized FIP cidrs if gw_port not exists or
# this is not snat host
if (not ex_gw_port or not self._is_this_snat_host() or
not self.snat_namespace.exists()):
return set()
interface_name = self.get_snat_external_device_interface_name(
ex_gw_port)
return set([addr['cidr'] for addr in ip_lib.get_devices_with_ip(
self.snat_namespace.name,
name=interface_name)])
def get_router_cidrs(self, device):
"""Over-ride the get_router_cidrs function to return the list.
This function is overridden to provide the complete list of
floating_ip cidrs that the router hosts.
This includes the centralized floatingip cidr list and the
regular floatingip cidr list that are bound to fip namespace.
"""
fip_cidrs = super(DvrEdgeRouter, self).get_router_cidrs(device)
centralized_cidrs = self.get_centralized_fip_cidr_set()
return fip_cidrs | centralized_cidrs
def remove_centralized_floatingip(self, fip_cidr):
"""Function to handle the centralized Floatingip remove."""
if not self.get_ex_gw_port():
return
if not self._is_this_snat_host():
return
interface_name = self.get_snat_external_device_interface_name(
self.get_ex_gw_port())
device = ip_lib.IPDevice(
interface_name, namespace=self.snat_namespace.name)
device.delete_addr_and_conntrack_state(fip_cidr)
self.process_floating_ip_nat_rules_for_centralized_floatingip()
def add_centralized_floatingip(self, fip, fip_cidr):
"""Function to handle the centralized Floatingip addition."""
if not self.get_ex_gw_port():
return
if not self._is_this_snat_host():
return
interface_name = self.get_snat_external_device_interface_name(
self.get_ex_gw_port())
try:
ip_lib.add_ip_address(fip_cidr, interface_name,
namespace=self.snat_namespace.name)
except ip_lib.IpAddressAlreadyExists:
pass
except RuntimeError:
LOG.warning("Unable to configure IP address for centralized "
"floating IP: %s", fip['id'])
return lib_constants.FLOATINGIP_STATUS_ERROR
self.process_floating_ip_nat_rules_for_centralized_floatingip()
# Send a GARP message on the external interface for the
# centralized floatingip configured.
ip_lib.send_ip_addr_adv_notif(self.snat_namespace.name,
interface_name,
fip['floating_ip_address'])
return lib_constants.FLOATINGIP_STATUS_ACTIVE
def _centralized_floating_forward_rules(self, floating_ip, fixed_ip):
to_source = '-s %s/32 -j SNAT --to-source %s' % (fixed_ip, floating_ip)
if self.snat_iptables_manager.random_fully:
to_source += ' --random-fully'
return [('PREROUTING', '-d %s/32 -j DNAT --to-destination %s' %
(floating_ip, fixed_ip)),
('OUTPUT', '-d %s/32 -j DNAT --to-destination %s' %
(floating_ip, fixed_ip)),
('float-snat', to_source)]
def _set_floating_ip_nat_rules_for_centralized_floatingip(self, fip):
if fip.get(lib_constants.DVR_SNAT_BOUND):
fixed = fip['fixed_ip_address']
fip_ip = fip['floating_ip_address']
for chain, rule in self._centralized_floating_forward_rules(
fip_ip, fixed):
self.snat_iptables_manager.ipv4['nat'].add_rule(
chain, rule, tag='floating_ip')
def process_floating_ip_nat_rules_for_centralized_floatingip(self):
self.snat_iptables_manager.ipv4['nat'].clear_rules_by_tag(
'floating_ip')
floating_ips = self.get_floating_ips()
for fip in floating_ips:
self._set_floating_ip_nat_rules_for_centralized_floatingip(fip)
self.snat_iptables_manager.apply()
def process_floating_ip_nat_rules(self):
if self._is_this_snat_host():
self.process_floating_ip_nat_rules_for_centralized_floatingip()
# Cover mixed dvr_snat and compute node, aka a dvr_snat node has both
# centralized and distributed floating IPs.
super(DvrEdgeRouter, self).process_floating_ip_nat_rules()