neutron/neutron/agent/l3/dvr_local_router.py

488 lines
22 KiB
Python

# 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.
import binascii
import collections
import netaddr
from oslo_log import log as logging
from oslo_utils import excutils
import six
from neutron.agent.l3 import dvr_fip_ns
from neutron.agent.l3 import dvr_router_base
from neutron.agent.linux import ip_lib
from neutron.common import constants as l3_constants
from neutron.common import exceptions
from neutron.common import utils as common_utils
from neutron.i18n import _LE, _LW
LOG = logging.getLogger(__name__)
# xor-folding mask used for IPv6 rule index
MASK_30 = 0x3fffffff
# Tracks the arp entry cache
Arp_entry = collections.namedtuple(
'Arp_entry', 'ip mac subnet_id operation')
class DvrLocalRouter(dvr_router_base.DvrRouterBase):
def __init__(self, agent, host, *args, **kwargs):
super(DvrLocalRouter, self).__init__(agent, host, *args, **kwargs)
self.floating_ips_dict = {}
# Linklocal subnet for router and floating IP namespace link
self.rtr_fip_subnet = None
self.dist_fip_count = None
self.fip_ns = None
self._pending_arp_set = set()
def get_floating_ips(self):
"""Filter Floating IPs to be hosted on this agent."""
floating_ips = super(DvrLocalRouter, self).get_floating_ips()
return [i for i in floating_ips if i['host'] == self.host]
def _handle_fip_nat_rules(self, interface_name):
"""Configures NAT rules for Floating IPs for DVR.
Remove all the rules. This is safe because if
use_namespaces is set as False then the agent can
only configure one router, otherwise each router's
NAT rules will be in their own namespace.
"""
self.iptables_manager.ipv4['nat'].empty_chain('POSTROUTING')
self.iptables_manager.ipv4['nat'].empty_chain('snat')
# Add back the jump to float-snat
self.iptables_manager.ipv4['nat'].add_rule('snat', '-j $float-snat')
# And add the NAT rule back
rule = ('POSTROUTING', '! -i %(interface_name)s '
'! -o %(interface_name)s -m conntrack ! '
'--ctstate DNAT -j ACCEPT' %
{'interface_name': interface_name})
self.iptables_manager.ipv4['nat'].add_rule(*rule)
self.iptables_manager.apply()
def floating_ip_added_dist(self, fip, fip_cidr):
"""Add floating IP to FIP namespace."""
floating_ip = fip['floating_ip_address']
fixed_ip = fip['fixed_ip_address']
self._add_floating_ip_rule(floating_ip, fixed_ip)
fip_2_rtr_name = self.fip_ns.get_int_device_name(self.router_id)
#Add routing rule in fip namespace
fip_ns_name = self.fip_ns.get_name()
if self.rtr_fip_subnet is None:
self.rtr_fip_subnet = self.fip_ns.local_subnets.allocate(
self.router_id)
rtr_2_fip, _ = self.rtr_fip_subnet.get_pair()
device = ip_lib.IPDevice(fip_2_rtr_name, namespace=fip_ns_name)
device.route.add_route(fip_cidr, str(rtr_2_fip.ip))
interface_name = (
self.fip_ns.get_ext_device_name(
self.fip_ns.agent_gateway_port['id']))
ip_lib.send_ip_addr_adv_notif(fip_ns_name,
interface_name,
floating_ip,
self.agent_conf)
# update internal structures
self.dist_fip_count = self.dist_fip_count + 1
def _add_floating_ip_rule(self, floating_ip, fixed_ip):
rule_pr = self.fip_ns.allocate_rule_priority(floating_ip)
self.floating_ips_dict[floating_ip] = rule_pr
ip_rule = ip_lib.IPRule(namespace=self.ns_name)
ip_rule.rule.add(ip=fixed_ip,
table=dvr_fip_ns.FIP_RT_TBL,
priority=rule_pr)
def _remove_floating_ip_rule(self, floating_ip):
if floating_ip in self.floating_ips_dict:
rule_pr = self.floating_ips_dict[floating_ip]
ip_rule = ip_lib.IPRule(namespace=self.ns_name)
ip_rule.rule.delete(ip=floating_ip,
table=dvr_fip_ns.FIP_RT_TBL,
priority=rule_pr)
self.fip_ns.deallocate_rule_priority(floating_ip)
#TODO(rajeev): Handle else case - exception/log?
def floating_ip_removed_dist(self, fip_cidr):
"""Remove floating IP from FIP namespace."""
floating_ip = fip_cidr.split('/')[0]
rtr_2_fip_name = self.fip_ns.get_rtr_ext_device_name(self.router_id)
fip_2_rtr_name = self.fip_ns.get_int_device_name(self.router_id)
if self.rtr_fip_subnet is None:
self.rtr_fip_subnet = self.fip_ns.local_subnets.allocate(
self.router_id)
rtr_2_fip, fip_2_rtr = self.rtr_fip_subnet.get_pair()
fip_ns_name = self.fip_ns.get_name()
self._remove_floating_ip_rule(floating_ip)
device = ip_lib.IPDevice(fip_2_rtr_name, namespace=fip_ns_name)
device.route.delete_route(fip_cidr, str(rtr_2_fip.ip))
# check if this is the last FIP for this router
self.dist_fip_count = self.dist_fip_count - 1
if self.dist_fip_count == 0:
#remove default route entry
device = ip_lib.IPDevice(rtr_2_fip_name, namespace=self.ns_name)
ns_ip = ip_lib.IPWrapper(namespace=fip_ns_name)
device.route.delete_gateway(str(fip_2_rtr.ip),
table=dvr_fip_ns.FIP_RT_TBL)
self.fip_ns.local_subnets.release(self.router_id)
self.rtr_fip_subnet = None
ns_ip.del_veth(fip_2_rtr_name)
self.fip_ns.unsubscribe(self.router_id)
# NOTE (Swami): The fg interface and the namespace will be deleted
# when the external gateway port is removed. This will be
# initiated from the server through an RPC call.
def floating_ip_moved_dist(self, fip):
"""Handle floating IP move between fixed IPs."""
floating_ip = fip['floating_ip_address']
self._remove_floating_ip_rule(floating_ip)
self._add_floating_ip_rule(floating_ip, fip['fixed_ip_address'])
def add_floating_ip(self, fip, interface_name, device):
if not self._add_fip_addr_to_device(fip, device):
return l3_constants.FLOATINGIP_STATUS_ERROR
# Special Handling for DVR - update FIP namespace
ip_cidr = common_utils.ip_to_cidr(fip['floating_ip_address'])
self.floating_ip_added_dist(fip, ip_cidr)
return l3_constants.FLOATINGIP_STATUS_ACTIVE
def remove_floating_ip(self, device, ip_cidr):
super(DvrLocalRouter, self).remove_floating_ip(device, ip_cidr)
self.floating_ip_removed_dist(ip_cidr)
def move_floating_ip(self, fip):
self.floating_ip_moved_dist(fip)
return l3_constants.FLOATINGIP_STATUS_ACTIVE
def _get_internal_port(self, subnet_id):
"""Return internal router port based on subnet_id."""
router_ports = self.router.get(l3_constants.INTERFACE_KEY, [])
for port in router_ports:
fips = port['fixed_ips']
for f in fips:
if f['subnet_id'] == subnet_id:
return port
def _cache_arp_entry(self, ip, mac, subnet_id, operation):
"""Cache the arp entries if device not ready."""
arp_entry_tuple = Arp_entry(ip=ip,
mac=mac,
subnet_id=subnet_id,
operation=operation)
self._pending_arp_set.add(arp_entry_tuple)
def _process_arp_cache_for_internal_port(self, subnet_id):
"""Function to process the cached arp entries."""
arp_remove = set()
for arp_entry in self._pending_arp_set:
if subnet_id == arp_entry.subnet_id:
try:
state = self._update_arp_entry(
arp_entry.ip, arp_entry.mac,
arp_entry.subnet_id, arp_entry.operation)
except Exception:
state = False
if state:
# If the arp update was successful, then
# go ahead and add it to the remove set
arp_remove.add(arp_entry)
self._pending_arp_set -= arp_remove
def _delete_arp_cache_for_internal_port(self, subnet_id):
"""Function to delete the cached arp entries."""
arp_delete = set()
for arp_entry in self._pending_arp_set:
if subnet_id == arp_entry.subnet_id:
arp_delete.add(arp_entry)
self._pending_arp_set -= arp_delete
def _update_arp_entry(self, ip, mac, subnet_id, operation):
"""Add or delete arp entry into router namespace for the subnet."""
port = self._get_internal_port(subnet_id)
# update arp entry only if the subnet is attached to the router
if not port:
return False
try:
# TODO(mrsmith): optimize the calls below for bulk calls
interface_name = self.get_internal_device_name(port['id'])
device = ip_lib.IPDevice(interface_name, namespace=self.ns_name)
if ip_lib.device_exists(interface_name, self.ns_name):
if operation == 'add':
device.neigh.add(ip, mac)
elif operation == 'delete':
device.neigh.delete(ip, mac)
return True
else:
if operation == 'add':
LOG.warn(_LW("Device %s does not exist so ARP entry "
"cannot be updated, will cache information "
"to be applied later when the device exists"),
device)
self._cache_arp_entry(ip, mac, subnet_id, operation)
return False
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception(_LE("DVR: Failed updating arp entry"))
def _set_subnet_arp_info(self, subnet_id):
"""Set ARP info retrieved from Plugin for existing ports."""
# TODO(Carl) Can we eliminate the need to make this RPC while
# processing a router.
subnet_ports = self.agent.get_ports_by_subnet(subnet_id)
for p in subnet_ports:
if p['device_owner'] not in l3_constants.ROUTER_INTERFACE_OWNERS:
for fixed_ip in p['fixed_ips']:
self._update_arp_entry(fixed_ip['ip_address'],
p['mac_address'],
subnet_id,
'add')
self._process_arp_cache_for_internal_port(subnet_id)
@staticmethod
def _get_snat_idx(ip_cidr):
"""Generate index for DVR snat rules and route tables.
The index value has to be 32 bits or less but more than the system
generated entries i.e. 32768. For IPv4 use the numeric value of the
cidr. For IPv6 generate a crc32 bit hash and xor-fold to 30 bits.
Use the freed range to extend smaller values so that they become
greater than system generated entries.
"""
net = netaddr.IPNetwork(ip_cidr)
if net.version == 6:
if isinstance(ip_cidr, six.text_type):
ip_cidr = ip_cidr.encode() # Needed for Python 3.x
# the crc32 & 0xffffffff is for Python 2.6 and 3.0 compatibility
snat_idx = binascii.crc32(ip_cidr) & 0xffffffff
# xor-fold the hash to reserve upper range to extend smaller values
snat_idx = (snat_idx >> 30) ^ (snat_idx & MASK_30)
if snat_idx < 32768:
snat_idx = snat_idx + MASK_30
else:
snat_idx = net.value
return snat_idx
def _delete_gateway_device_if_exists(self, ns_ip_device, gw_ip_addr,
snat_idx):
try:
ns_ip_device.route.delete_gateway(gw_ip_addr,
table=snat_idx)
except exceptions.DeviceNotFoundError:
pass
def _snat_redirect_modify(self, gateway, sn_port, sn_int, is_add):
"""Adds or removes rules and routes for SNAT redirection."""
try:
ns_ipr = ip_lib.IPRule(namespace=self.ns_name)
ns_ipd = ip_lib.IPDevice(sn_int, namespace=self.ns_name)
if is_add:
ns_ipwrapr = ip_lib.IPWrapper(namespace=self.ns_name)
for port_fixed_ip in sn_port['fixed_ips']:
# Find the first gateway IP address matching this IP version
port_ip_addr = port_fixed_ip['ip_address']
port_ip_vers = netaddr.IPAddress(port_ip_addr).version
for gw_fixed_ip in gateway['fixed_ips']:
gw_ip_addr = gw_fixed_ip['ip_address']
if netaddr.IPAddress(gw_ip_addr).version == port_ip_vers:
sn_port_cidr = common_utils.ip_to_cidr(
port_ip_addr, port_fixed_ip['prefixlen'])
snat_idx = self._get_snat_idx(sn_port_cidr)
if is_add:
ns_ipd.route.add_gateway(gw_ip_addr,
table=snat_idx)
ns_ipr.rule.add(ip=sn_port_cidr,
table=snat_idx,
priority=snat_idx)
ns_ipwrapr.netns.execute(
['sysctl', '-w',
'net.ipv4.conf.%s.send_redirects=0' % sn_int])
else:
self._delete_gateway_device_if_exists(ns_ipd,
gw_ip_addr,
snat_idx)
ns_ipr.rule.delete(ip=sn_port_cidr,
table=snat_idx,
priority=snat_idx)
break
except Exception:
if is_add:
exc = _LE('DVR: error adding redirection logic')
else:
exc = _LE('DVR: snat remove failed to clear the rule '
'and device')
LOG.exception(exc)
def _snat_redirect_add(self, gateway, sn_port, sn_int):
"""Adds rules and routes for SNAT redirection."""
self._snat_redirect_modify(gateway, sn_port, sn_int, is_add=True)
def _snat_redirect_remove(self, gateway, sn_port, sn_int):
"""Removes rules and routes for SNAT redirection."""
self._snat_redirect_modify(gateway, sn_port, sn_int, is_add=False)
def internal_network_added(self, port):
super(DvrLocalRouter, self).internal_network_added(port)
# NOTE: The following function _set_subnet_arp_info
# should be called to dynamically populate the arp
# entries for the dvr services ports into the router
# namespace. This does not have dependency on the
# external_gateway port or the agent_mode.
for subnet in port['subnets']:
self._set_subnet_arp_info(subnet['id'])
ex_gw_port = self.get_ex_gw_port()
if not ex_gw_port:
return
sn_port = self.get_snat_port_for_internal_port(port)
if not sn_port:
return
interface_name = self.get_internal_device_name(port['id'])
self._snat_redirect_add(sn_port, port, interface_name)
def _dvr_internal_network_removed(self, 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
# DVR handling code for SNAT
interface_name = self.get_internal_device_name(port['id'])
self._snat_redirect_remove(sn_port, port, interface_name)
# Clean up the cached arp entries related to the port subnet
for subnet in port['subnets']:
self._delete_arp_cache_for_internal_port(subnet)
def internal_network_removed(self, port):
self._dvr_internal_network_removed(port)
super(DvrLocalRouter, self).internal_network_removed(port)
def get_floating_agent_gw_interface(self, ext_net_id):
"""Filter Floating Agent GW port for the external network."""
fip_ports = self.router.get(l3_constants.FLOATINGIP_AGENT_INTF_KEY, [])
return next(
(p for p in fip_ports if p['network_id'] == ext_net_id), None)
def get_external_device_interface_name(self, ex_gw_port):
fip_int = self.fip_ns.get_int_device_name(self.router_id)
if ip_lib.device_exists(fip_int, namespace=self.fip_ns.get_name()):
return self.fip_ns.get_rtr_ext_device_name(self.router_id)
def external_gateway_added(self, ex_gw_port, interface_name):
# TODO(Carl) Refactor external_gateway_added/updated/removed to use
# super class implementation where possible. Looks like preserve_ips,
# and ns_name are the key differences.
ip_wrapr = ip_lib.IPWrapper(namespace=self.ns_name)
ip_wrapr.netns.execute(['sysctl', '-w',
'net.ipv4.conf.all.send_redirects=0'])
for p in self.internal_ports:
gateway = self.get_snat_port_for_internal_port(p)
id_name = self.get_internal_device_name(p['id'])
if gateway:
self._snat_redirect_add(gateway, p, id_name)
for port in self.get_snat_interfaces():
for ip in port['fixed_ips']:
self._update_arp_entry(ip['ip_address'],
port['mac_address'],
ip['subnet_id'],
'add')
def external_gateway_updated(self, ex_gw_port, interface_name):
pass
def external_gateway_removed(self, ex_gw_port, interface_name):
# TODO(Carl) Should this be calling process_snat_dnat_for_fip?
self.process_floating_ip_nat_rules()
if self.fip_ns:
to_fip_interface_name = (
self.get_external_device_interface_name(ex_gw_port))
self.process_floating_ip_addresses(to_fip_interface_name)
for p in self.internal_ports:
# NOTE: When removing the gateway port, pass in the snat_port
# cache along with the current ports.
gateway = self.get_snat_port_for_internal_port(p, self.snat_ports)
internal_interface = self.get_internal_device_name(p['id'])
self._snat_redirect_remove(gateway, p, internal_interface)
def _handle_router_snat_rules(self, ex_gw_port, interface_name):
pass
def process_external(self, agent):
ex_gw_port = self.get_ex_gw_port()
if ex_gw_port:
self.create_dvr_fip_interfaces(ex_gw_port)
super(DvrLocalRouter, self).process_external(agent)
def create_dvr_fip_interfaces(self, ex_gw_port):
floating_ips = self.get_floating_ips()
fip_agent_port = self.get_floating_agent_gw_interface(
ex_gw_port['network_id'])
if fip_agent_port:
LOG.debug("FloatingIP agent gateway port received from the "
"plugin: %s", fip_agent_port)
is_first = False
if floating_ips:
is_first = self.fip_ns.subscribe(self.router_id)
if is_first and not fip_agent_port:
LOG.debug("No FloatingIP agent gateway port possibly due to "
"late binding of the private port to the host, "
"requesting agent gateway port for 'network-id' :"
"%s", ex_gw_port['network_id'])
fip_agent_port = self.agent.plugin_rpc.get_agent_gateway_port(
self.agent.context, ex_gw_port['network_id'])
if not fip_agent_port:
LOG.error(_LE("No FloatingIP agent gateway port "
"returned from server for 'network-id': "
"%s"), ex_gw_port['network_id'])
if fip_agent_port:
if 'subnets' not in fip_agent_port:
LOG.error(_LE('Missing subnet/agent_gateway_port'))
else:
if is_first:
self.fip_ns.create_gateway_port(fip_agent_port)
else:
self.fip_ns.update_gateway_port(fip_agent_port)
if (self.fip_ns.agent_gateway_port and
(self.dist_fip_count == 0 or is_first)):
self.fip_ns.create_rtr_2_fip_link(self)
# kicks the FW Agent to add rules for the IR namespace if
# configured
self.agent.process_router_add(self)
def process(self, agent):
ex_gw_port = self.get_ex_gw_port()
if ex_gw_port:
self.fip_ns = agent.get_fip_ns(ex_gw_port['network_id'])
self.fip_ns.scan_fip_ports(self)
super(DvrLocalRouter, self).process(agent)