ovn-bgp-agent/ovn_bgp_agent/utils/linux_net.py
Luis Tomas Bolivar 00749e404d Ensure proper order during expose/withdraw
When exposing IPs, there is a need to first wire it, i.e., ensure
connectivity to/from OVN overlay, and then expose the IP through
BGP. For withdrawn the process is the opposite, first withdraw the
IP through BGP, and then remove the wiring

Change-Id: I3d41380829e2aa5dc3109a37f8879246a718c8d7
2023-03-14 12:11:08 +01:00

671 lines
24 KiB
Python

# Copyright 2021 Red Hat, Inc.
#
# 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 ipaddress
import random
import re
import sys
from socket import AF_INET
from socket import AF_INET6
from oslo_log import log as logging
import pyroute2
from pyroute2.netlink import exceptions as netlink_exceptions
import tenacity
from ovn_bgp_agent import constants
from ovn_bgp_agent import exceptions as agent_exc
import ovn_bgp_agent.privileged.linux_net
LOG = logging.getLogger(__name__)
def get_ip_version(ip):
return ipaddress.ip_address(ip.split('/')[0]).version
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_interfaces(filter_out=[]):
with pyroute2.NDB() as ndb:
return [iface.ifname for iface in ndb.interfaces
if iface.ifname not in filter_out]
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_interface_index(nic):
with pyroute2.NDB() as ndb:
return ndb.interfaces[nic]['index']
def ensure_vrf(vrf_name, vrf_table):
ovn_bgp_agent.privileged.linux_net.ensure_vrf(vrf_name, vrf_table)
def ensure_bridge(bridge_name):
ovn_bgp_agent.privileged.linux_net.ensure_bridge(bridge_name)
def ensure_vxlan(vxlan_name, vni, local_ip, dstport):
ovn_bgp_agent.privileged.linux_net.ensure_vxlan(vxlan_name, vni, local_ip,
dstport)
def ensure_veth(veth_name, veth_peer):
ovn_bgp_agent.privileged.linux_net.ensure_veth(veth_name, veth_peer)
def set_master_for_device(device, master):
ovn_bgp_agent.privileged.linux_net.set_master_for_device(device, master)
def ensure_dummy_device(device):
ovn_bgp_agent.privileged.linux_net.ensure_dummy_device(device)
def ensure_ovn_device(ovn_ifname, vrf_name):
ensure_dummy_device(ovn_ifname)
set_master_for_device(ovn_ifname, vrf_name)
def delete_device(device):
ovn_bgp_agent.privileged.linux_net.delete_device(device)
def ensure_arp_ndp_enabled_for_bridge(bridge, offset, vlan_tag=None):
ipv4 = "192.168." + str(int(offset / 256)) + "." + str(offset % 256)
ipv6 = "fd53:d91e:400:7f17::%x" % offset
try:
ovn_bgp_agent.privileged.linux_net.add_ip_to_dev(ipv4, bridge)
except KeyError as e:
if "object exists" not in str(e):
LOG.error("Unable to add IP on bridge %s to enable arp/ndp. "
"Exception: %s", bridge, e)
raise
try:
ovn_bgp_agent.privileged.linux_net.add_ip_to_dev(ipv6, bridge)
except KeyError as e:
if "object exists" not in str(e):
LOG.error("Unable to add IP on bridge %s to enable arp/ndp. "
"Exception: %s", bridge, e)
raise
if not vlan_tag:
enable_proxy_arp(bridge)
enable_proxy_ndp(bridge)
def ensure_routing_table_for_bridge(ovn_routing_tables, bridge, vrf_table):
# check a routing table with the bridge name exists on
# /etc/iproute2/rt_tables
regex = r'^[0-9]*[\s]*{}$'.format(bridge)
matching_table = [line.replace('\t', ' ')
for line in open('/etc/iproute2/rt_tables')
if re.findall(regex, line)]
if matching_table:
table_info = matching_table[0].strip().split()
ovn_routing_tables[table_info[1]] = int(table_info[0])
LOG.debug("Found routing table for %s with: %s", bridge,
table_info)
# if not configured, add random number for the table
else:
LOG.debug("Routing table for bridge %s not configured "
"at /etc/iproute2/rt_tables", bridge)
regex = r'^[0-9]+[\s]*'
existing_routes = [int(line.replace('\t', ' ').split(' ')[0])
for line in open('/etc/iproute2/rt_tables')
if re.findall(regex, line)]
# pick a number between 1 and 252
try:
table_number = random.choice(list(
set([x for x in range(1, 253)
if x != int(vrf_table)]).difference(
set(existing_routes))))
except IndexError:
LOG.error("No more routing tables available for bridge %s "
"at /etc/iproute2/rt_tables", bridge)
sys.exit()
ovn_bgp_agent.privileged.linux_net.create_routing_table_for_bridge(
table_number, bridge)
ovn_routing_tables[bridge] = int(table_number)
LOG.debug("Added routing table for %s with number: %s", bridge,
table_number)
return _ensure_routing_table_routes(ovn_routing_tables, bridge)
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def _ensure_routing_table_routes(ovn_routing_tables, bridge):
# add default route on that table if it does not exist
extra_routes = []
with pyroute2.NDB() as ndb:
table_route_dsts = set(
[
(r.dst, r.dst_len)
for r in ndb.routes.summary().filter(
table=ovn_routing_tables[bridge]
)
]
)
if not table_route_dsts:
r1 = {'dst': 'default', 'oif': ndb.interfaces[bridge]['index'],
'table': ovn_routing_tables[bridge], 'scope': 253,
'proto': 3}
ovn_bgp_agent.privileged.linux_net.route_create(r1)
r2 = {'dst': 'default', 'oif': ndb.interfaces[bridge]['index'],
'table': ovn_routing_tables[bridge], 'family': AF_INET6,
'proto': 3}
ovn_bgp_agent.privileged.linux_net.route_create(r2)
else:
route_missing = True
route6_missing = True
for (dst, dst_len) in table_route_dsts:
if not dst: # default route
try:
route = ndb.routes[
{'table': ovn_routing_tables[bridge],
'dst': '',
'family': AF_INET}]
if (bridge ==
ndb.interfaces[{'index': route['oif']}][
'ifname']):
route_missing = False
else:
extra_routes.append(route)
except KeyError:
pass # no ipv4 default rule
try:
route_6 = ndb.routes[
{'table': ovn_routing_tables[bridge],
'dst': '',
'family': AF_INET6}]
if (bridge ==
ndb.interfaces[{'index': route_6['oif']}][
'ifname']):
route6_missing = False
else:
extra_routes.append(route_6)
except KeyError:
pass # no ipv6 default rule
else:
if get_ip_version(dst) == constants.IP_VERSION_6:
extra_routes.append(
ndb.routes[{'table': ovn_routing_tables[bridge],
'dst': dst,
'dst_len': dst_len,
'family': AF_INET6}]
)
else:
extra_routes.append(
ndb.routes[{'table': ovn_routing_tables[bridge],
'dst': dst,
'dst_len': dst_len,
'family': AF_INET}]
)
if route_missing:
r = {'dst': 'default', 'oif': ndb.interfaces[bridge]['index'],
'table': ovn_routing_tables[bridge], 'scope': 253,
'proto': 3}
ovn_bgp_agent.privileged.linux_net.route_create(r)
if route6_missing:
r = {'dst': 'default', 'oif': ndb.interfaces[bridge]['index'],
'table': ovn_routing_tables[bridge], 'family': AF_INET6,
'proto': 3}
ovn_bgp_agent.privileged.linux_net.route_create(r)
return extra_routes
def ensure_vlan_device_for_network(bridge, vlan_tag):
ovn_bgp_agent.privileged.linux_net.ensure_vlan_device_for_network(bridge,
vlan_tag)
device = "{}/{}".format(bridge, vlan_tag)
enable_proxy_arp(device)
enable_proxy_ndp(device)
def delete_vlan_device_for_network(bridge, vlan_tag):
vlan_device_name = '{}.{}'.format(bridge, vlan_tag)
delete_device(vlan_device_name)
def enable_proxy_ndp(device):
flag = "net.ipv6.conf.{}.proxy_ndp".format(device)
ovn_bgp_agent.privileged.linux_net.set_kernel_flag(flag, 1)
def enable_proxy_arp(device):
flag = "net.ipv4.conf.{}.proxy_arp".format(device)
ovn_bgp_agent.privileged.linux_net.set_kernel_flag(flag, 1)
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_exposed_ips(nic):
exposed_ips = []
with pyroute2.NDB() as ndb:
exposed_ips = [ip.address
for ip in ndb.interfaces[nic].ipaddr.summary()
if ip.prefixlen == 32 or ip.prefixlen == 128]
return exposed_ips
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_nic_ip(nic, prefixlen_filter=None):
exposed_ips = []
with pyroute2.NDB() as ndb:
if prefixlen_filter:
exposed_ips = [ip.address
for ip in ndb.interfaces[nic].ipaddr.summary(
).filter(prefixlen=prefixlen_filter)]
else:
exposed_ips = [ip.address
for ip in ndb.interfaces[nic].ipaddr.summary()]
return exposed_ips
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_exposed_ips_on_network(nic, network):
exposed_ips = []
with pyroute2.NDB() as ndb:
try:
exposed_ips = [ip.address
for ip in ndb.interfaces[nic].ipaddr.summary()
if ((ip.prefixlen == 32 or ip.prefixlen == 128) and
ipaddress.ip_address(ip.address) in network)]
except KeyError:
# Nic does not exists
LOG.debug("Nic %s does not yet exists, so it does not have "
"exposed IPs", nic)
return exposed_ips
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_exposed_routes_on_network(table_ids, network):
with pyroute2.NDB() as ndb:
# NOTE: skip bgp routes (proto 186)
return [
r
for r in ndb.routes.dump()
if r.table in table_ids and
r.dst != "" and
r.gateway is not None and
r.proto != 186 and
ipaddress.ip_address(r.gateway) in network
]
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_ovn_ip_rules(routing_table):
# get the rules pointing to ovn bridges
ovn_ip_rules = {}
with pyroute2.NDB() as ndb:
rules_info = [(rule.table,
"{}/{}".format(rule.dst, rule.dst_len),
rule.family) for rule in ndb.rules.dump()
if rule.table in routing_table]
for table, dst, family in rules_info:
ovn_ip_rules[dst] = {'table': table, 'family': family}
return ovn_ip_rules
def delete_exposed_ips(ips, nic):
ovn_bgp_agent.privileged.linux_net.delete_exposed_ips(ips, nic)
def delete_ip_rules(ip_rules):
ovn_bgp_agent.privileged.linux_net.delete_ip_rules(ip_rules)
def delete_bridge_ip_routes(routing_tables, routing_tables_routes,
extra_routes):
with pyroute2.NDB() as ndb:
for device, routes_info in routing_tables_routes.items():
if not extra_routes.get(device):
continue
for route_info in routes_info:
oif = ndb.interfaces[device]['index']
if route_info['vlan']:
vlan_device_name = '{}.{}'.format(device,
route_info['vlan'])
oif = ndb.interfaces[vlan_device_name]['index']
if 'gateway' in route_info['route'].keys(): # subnet route
possible_matchings = [
r for r in extra_routes[device]
if (r['dst'] == route_info['route']['dst'] and
r['dst_len'] == route_info['route']['dst_len'] and
r['gateway'] == route_info['route']['gateway'])]
else: # cr-lrp
possible_matchings = [
r for r in extra_routes[device]
if (r['dst'] == route_info['route']['dst'] and
r['dst_len'] == route_info['route']['dst_len'] and
r['oif'] == oif)]
for r in possible_matchings:
extra_routes[device].remove(r)
for bridge, routes in extra_routes.items():
for route in routes:
r_info = {'dst': route['dst'],
'dst_len': route['dst_len'],
'family': route['family'],
'oif': route['oif'],
'gateway': route['gateway'],
'table': routing_tables[bridge]}
ovn_bgp_agent.privileged.linux_net.route_delete(r_info)
def delete_routes_from_table(table):
table_routes = _get_table_routes(table)
delete_ip_routes(table_routes)
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def _get_table_routes(table):
with pyroute2.NDB() as ndb:
# FIXME: problem in pyroute2 removing routes with local (254) scope
return [r for r in ndb.routes.dump().filter(table=table)
if r.scope != 254 and r.proto != 186]
@tenacity.retry(
retry=tenacity.retry_if_exception_type(
netlink_exceptions.NetlinkDumpInterrupted),
wait=tenacity.wait_exponential(multiplier=0.02, max=1),
stop=tenacity.stop_after_delay(8),
reraise=True)
def get_routes_on_tables(table_ids):
with pyroute2.NDB() as ndb:
# NOTE: skip bgp routes (proto 186)
return [r for r in ndb.routes.dump()
if r.table in table_ids and r.dst != '' and r.proto != 186]
def delete_ip_routes(routes):
for route in routes:
r_info = {'dst': route['dst'],
'dst_len': route['dst_len'],
'family': route['family'],
'oif': route['oif'],
'gateway': route['gateway'],
'table': route['table']}
ovn_bgp_agent.privileged.linux_net.route_delete(r_info)
def add_ndp_proxy(ip, dev, vlan=None):
ovn_bgp_agent.privileged.linux_net.add_ndp_proxy(ip, dev, vlan)
def del_ndp_proxy(ip, dev, vlan=None):
ovn_bgp_agent.privileged.linux_net.del_ndp_proxy(ip, dev, vlan)
def add_ips_to_dev(nic, ips, clear_local_route_at_table=False):
already_added_ips = []
for ip in ips:
try:
ovn_bgp_agent.privileged.linux_net.add_ip_to_dev(ip, nic)
except KeyError:
# NDB raises KeyError: 'object exists'
# if the ip is already added
already_added_ips.append(ip)
if clear_local_route_at_table:
for ip in ips:
if ip in already_added_ips:
continue
with pyroute2.NDB() as ndb:
oif = ndb.interfaces[nic]['index']
route = {'table': clear_local_route_at_table,
'proto': 2,
'scope': 254,
'dst': ip,
'oif': oif}
ovn_bgp_agent.privileged.linux_net.route_delete(route)
def del_ips_from_dev(nic, ips):
for ip in ips:
ovn_bgp_agent.privileged.linux_net.del_ip_from_dev(ip, nic)
def add_ip_rule(ip, table, dev=None, lladdr=None):
ip_version = get_ip_version(ip)
ip_info = ip.split("/")
if len(ip_info) == 1:
rule = {'dst': ip_info[0], 'table': table, 'dst_len': 32}
if ip_version == constants.IP_VERSION_6:
rule['dst_len'] = 128
rule['family'] = AF_INET6
elif len(ip_info) == 2:
rule = {'dst': ip_info[0], 'table': table, 'dst_len': int(ip_info[1])}
if ip_version == constants.IP_VERSION_6:
rule['family'] = AF_INET6
else:
raise agent_exc.InvalidPortIP(ip=ip)
ovn_bgp_agent.privileged.linux_net.rule_create(rule)
if lladdr:
add_ip_nei(ip, lladdr, dev)
def add_ip_nei(ip, lladdr, dev):
"""Add ip neighbor permament entry
param ip: IP of the neighbor to add an entry for
param lladdr: link layer address of the neighbor to associate to that IP
param dev: the interface to which the neighbor is attached
"""
# FIXME: There is no support for creating neighbours in NDB
# So we are using iproute here
ovn_bgp_agent.privileged.linux_net.add_ip_nei(ip, lladdr, dev)
def del_ip_rule(ip, table, dev=None, lladdr=None):
ip_version = get_ip_version(ip)
ip_info = ip.split("/")
if len(ip_info) == 1:
rule = {'dst': ip_info[0], 'table': table, 'dst_len': 32}
if ip_version == constants.IP_VERSION_6:
rule['dst_len'] = 128
rule['family'] = AF_INET6
elif len(ip_info) == 2:
rule = {'dst': ip_info[0], 'table': table, 'dst_len': int(ip_info[1])}
if ip_version == constants.IP_VERSION_6:
rule['family'] = AF_INET6
else:
raise agent_exc.InvalidPortIP(ip=ip)
ovn_bgp_agent.privileged.linux_net.rule_delete(rule)
if lladdr:
del_ip_nei(ip, lladdr, dev)
def del_ip_nei(ip, lladdr, dev):
"""Del ip neighbor permament entry
param ip: IP of the neighbor to delete the entry
param lladdr: link layer address of the neighbor to disassociate
param dev: the interface to which the neighbor is attached
"""
# FIXME: There is no support for deleting neighbours in NDB
# So we are using iproute here
ovn_bgp_agent.privileged.linux_net.del_ip_nei(ip, lladdr, dev)
def add_unreachable_route(vrf_name):
ovn_bgp_agent.privileged.linux_net.add_unreachable_route(vrf_name)
def add_ip_route(ovn_routing_tables_routes, ip_address, route_table, dev,
vlan=None, mask=None, via=None):
net_ip = ip_address
if not mask: # default /32 or /128
if get_ip_version(ip_address) == constants.IP_VERSION_6:
mask = 128
else:
mask = 32
else:
ip = '{}/{}'.format(ip_address, mask)
if get_ip_version(ip_address) == constants.IP_VERSION_6:
net_ip = '{}'.format(ipaddress.IPv6Network(
ip, strict=False).network_address)
else:
net_ip = '{}'.format(ipaddress.IPv4Network(
ip, strict=False).network_address)
with pyroute2.NDB() as ndb:
if vlan:
oif_name = '{}.{}'.format(dev, vlan)
try:
oif = ndb.interfaces[oif_name]['index']
except KeyError:
# Most provider network was recently created an
# there has not been a sync since then, therefore
# the vlan device has not yet been created
# Trying to create the device and retrying
ensure_vlan_device_for_network(dev, vlan)
oif = ndb.interfaces[oif_name]['index']
else:
oif = ndb.interfaces[dev]['index']
route = {'dst': net_ip, 'dst_len': int(mask), 'oif': oif,
'table': int(route_table), 'proto': 3}
if via:
route['gateway'] = via
route['scope'] = 0
else:
route['scope'] = 253
if get_ip_version(net_ip) == constants.IP_VERSION_6:
route['family'] = AF_INET6
del route['scope']
with pyroute2.NDB() as ndb:
try:
with ndb.routes[route]:
LOG.debug("Route already existing: %s", route)
except KeyError:
LOG.debug("Creating route at table %s: %s", route_table, route)
ovn_bgp_agent.privileged.linux_net.route_create(route)
LOG.debug("Route created at table %s: %s", route_table, route)
route_info = {'vlan': vlan, 'route': route}
ovn_routing_tables_routes.setdefault(dev, []).append(route_info)
def del_ip_route(ovn_routing_tables_routes, ip_address, route_table, dev,
vlan=None, mask=None, via=None):
net_ip = ip_address
if not mask: # default /32 or /128
if get_ip_version(ip_address) == constants.IP_VERSION_6:
mask = 128
else:
mask = 32
else:
ip = '{}/{}'.format(ip_address, mask)
if get_ip_version(ip_address) == constants.IP_VERSION_6:
net_ip = '{}'.format(ipaddress.IPv6Network(
ip, strict=False).network_address)
else:
net_ip = '{}'.format(ipaddress.IPv4Network(
ip, strict=False).network_address)
with pyroute2.NDB() as ndb:
try:
if vlan:
oif_name = '{}.{}'.format(dev, vlan)
oif = ndb.interfaces[oif_name]['index']
else:
oif = ndb.interfaces[dev]['index']
except KeyError:
LOG.debug("Device %s does not exists, so the associated "
"routes should have been automatically deleted.", dev)
ovn_routing_tables_routes.pop(dev, None)
return
route = {'dst': net_ip, 'dst_len': int(mask), 'oif': oif,
'table': int(route_table), 'proto': 3}
if via:
route['gateway'] = via
route['scope'] = 0
else:
route['scope'] = 253
if get_ip_version(net_ip) == constants.IP_VERSION_6:
route['family'] = AF_INET6
del route['scope']
LOG.debug("Deleting route at table %s: %s", route_table, route)
ovn_bgp_agent.privileged.linux_net.route_delete(route)
LOG.debug("Route deleted at table %s: %s", route_table, route)
route_info = {'vlan': vlan, 'route': route}
if route_info in ovn_routing_tables_routes.get(dev, []):
ovn_routing_tables_routes[dev].remove(route_info)
def set_device_status(device, status, ndb=None):
ovn_bgp_agent.privileged.linux_net.set_device_status(
device, status, ndb=ndb)