"""BGP implementation for FAUCET."""
# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2015 Brad Cowie, Christopher Lorier and Joe Stringer.
# Copyright (C) 2015 Research and Education Advanced Network New Zealand Ltd.
# Copyright (C) 2015--2017 The Contributors
#
# 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 json
import ipaddress
from ryu.services.protocols.bgp.bgpspeaker import BGPSpeaker
from ryu.services.protocols.bgp.api.base import CoreNotStarted
from faucet.valve_util import btos
[docs]class FaucetBgp(object):
def __init__(self, logger, send_flow_msgs):
self._dp_bgp_speakers = {}
self._metrics = None
self._valves = None
self.logger = logger
self._send_flow_msgs = send_flow_msgs
def _bgp_route_handler(self, path_change, vlan):
"""Handle a BGP change event.
Args:
path_change (ryu.services.protocols.bgp.bgpspeaker.EventPrefix): path change
vlan (vlan): Valve VLAN this path change was received for.
"""
prefix = ipaddress.ip_network(btos(path_change.prefix))
nexthop = ipaddress.ip_address(btos(path_change.nexthop))
withdraw = path_change.is_withdraw
flowmods = []
if not self._valves or vlan.dp_id not in self._valves:
return
valve = self._valves[vlan.dp_id]
if vlan.is_faucet_vip(nexthop):
self.logger.error(
'BGP nexthop %s for prefix %s cannot be us',
nexthop, prefix)
return
if vlan.ip_in_vip_subnet(nexthop) is None:
self.logger.error(
'BGP nexthop %s for prefix %s is not a connected network',
nexthop, prefix)
return
if withdraw:
self.logger.info(
'BGP withdraw %s nexthop %s', prefix, nexthop)
flowmods = valve.del_route(vlan, prefix)
else:
self.logger.info(
'BGP add %s nexthop %s', prefix, nexthop)
flowmods = valve.add_route(vlan, nexthop, prefix)
if flowmods:
self._send_flow_msgs(vlan.dp_id, flowmods)
def _create_bgp_speaker_for_vlan(self, vlan):
"""Set up BGP speaker for an individual VLAN if required.
Args:
vlan (vlan): VLAN associated with this speaker.
Returns:
ryu.services.protocols.bgp.bgpspeaker.BGPSpeaker: BGP speaker.
"""
handler = lambda x: self._bgp_route_handler(x, vlan)
bgp_speaker = BGPSpeaker(
as_number=vlan.bgp_as,
router_id=vlan.bgp_routerid,
bgp_server_port=vlan.bgp_port,
bgp_server_hosts=vlan.bgp_server_addresses,
best_path_change_handler=handler)
for faucet_vip in vlan.faucet_vips:
bgp_speaker.prefix_add(
prefix=str(faucet_vip), next_hop=str(faucet_vip.ip))
for ipv in vlan.ipvs():
routes = vlan.routes_by_ipv(ipv)
for ip_dst, ip_gw in list(routes.items()):
bgp_speaker.prefix_add(
prefix=str(ip_dst), next_hop=str(ip_gw))
for bgp_neighbor_address in vlan.bgp_neighbor_addresses:
bgp_speaker.neighbor_add(
address=bgp_neighbor_address,
remote_as=vlan.bgp_neighbor_as,
local_address=vlan.bgp_local_address,
enable_ipv4=True,
enable_ipv6=True)
return bgp_speaker
[docs] def reset(self, valves, metrics):
"""Set up a BGP speaker for every VLAN that requires it."""
self._valves = valves
self._metrics = metrics
# TODO: port status changes should cause us to withdraw a route.
for dp_id, valve in list(self._valves.items()):
if dp_id not in self._dp_bgp_speakers:
self._dp_bgp_speakers[dp_id] = {}
bgp_speakers = self._dp_bgp_speakers[dp_id]
for bgp_speaker in list(bgp_speakers.values()):
bgp_speaker.shutdown()
for vlan in list(valve.dp.vlans.values()):
if vlan.bgp_as:
bgp_speakers[vlan] = self._create_bgp_speaker_for_vlan(vlan)
[docs] def update_metrics(self):
"""Update BGP metrics."""
for dp_id, bgp_speakers in list(self._dp_bgp_speakers.items()):
for vlan, bgp_speaker in list(bgp_speakers.items()):
if bgp_speaker is not None:
try:
neighbor_states = list(json.loads(
bgp_speaker.neighbor_state_get()).items())
except CoreNotStarted:
continue
for neighbor, neighbor_state in neighbor_states:
base_labels = self._valves[dp_id].base_prom_labels
# pylint: disable=no-member
self._metrics.bgp_neighbor_uptime_seconds.labels(
**dict(base_labels, vlan=vlan.vid, neighbor=neighbor)).set(
neighbor_state['info']['uptime'])
for ipv in vlan.ipvs():
# pylint: disable=no-member
self._metrics.bgp_neighbor_routes.labels(
**dict(base_labels, vlan=vlan.vid, neighbor=neighbor, ipv=ipv)).set(
len(vlan.routes_by_ipv(ipv)))