os-ken/os_ken/services/protocols/vrrp/sample_router.py

540 lines
20 KiB
Python

# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2013 Isaku Yamahata <yamahata at private email ne jp>
#
# 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.
"""
router implementation base class
a template for router implementation that support VRRP
Those routers needs to be created by someone else.
sample_manager.routerManager is an example.
Usage example:
PYTHONPATH=. ./bin/osken-manager --verbose \
os_ken.services.protocols.vrrp.manager \
os_ken.services.protocols.vrrp.dumper \
os_ken.services.protocols.vrrp.sample_manager
"""
import contextlib
import greenlet
import socket
from os_ken.base import app_manager
from os_ken.controller import handler
from os_ken.controller import ofp_event
from os_ken.lib import hub
from os_ken.lib import mac as mac_lib
from os_ken.lib.packet import arp
from os_ken.lib.packet import ethernet
from os_ken.lib.packet import packet
from os_ken.lib.packet import vlan
from os_ken.lib.packet import vrrp
from os_ken.ofproto import ether
from os_ken.ofproto import ofproto_v1_2
from os_ken.services.protocols.vrrp import api as vrrp_api
from os_ken.services.protocols.vrrp import event as vrrp_event
from os_ken.services.protocols.vrrp import utils
class RouterBase(app_manager.OSKenApp):
def _router_name(self, config, interface):
ip_version = 'ipv6' if config.is_ipv6 else 'ipv4'
return '%s-%s-%d-%s' % (self.__class__.__name__,
str(interface), config.vrid, ip_version)
def __init__(self, *args, **kwargs):
super(RouterBase, self).__init__(*args, **kwargs)
self.instance_name = kwargs['name']
self.monitor_name = kwargs['monitor_name']
self.config = kwargs['config']
self.interface = kwargs['interface']
self.name = self._router_name(self.config, self.interface)
def _transmit(self, data):
vrrp_api.vrrp_transmit(self, self.monitor_name, data)
def _initialized(self):
self.logger.debug('initialized')
def _initialized_to_master(self):
self.logger.debug('initialized to master')
# RFC3768 6.4.1
# o Broadcast a gratuitous ARP request containing the virtual
# router MAC address for each IP address associated with the
# virtual router.
#
# or
#
# RFC 5795 6.4.1
# (115)+ If the protected IPvX address is an IPv4 address, then:
# (120) * Broadcast a gratuitous ARP request containing the
# virtual router MAC address for each IP address associated
# with the virtual router.
# (125) + else // IPv6
# (130) * For each IPv6 address associated with the virtual
# router, send an unsolicited ND Neighbor Advertisement with
# the Router Flag (R) set, the Solicited Flag (S) unset, the
# Override flag (O) set, the target address set to the IPv6
# address of the virtual router, and the target link-layer
# address set to the virtual router MAC address.
def _become_master(self):
self.logger.debug('become master')
# RFC3768 6.4.2
# o Broadcast a gratuitous ARP request containing the virtual
# router MAC address for each IP address associated with the
# virtual router
#
# or
#
# RFC 5795 6.4.2
# (375)+ If the protected IPvX address is an IPv4 address, then:
# (380)* Broadcast a gratuitous ARP request on that interface
# containing the virtual router MAC address for each IPv4
# address associated with the virtual router.
# (385) + else // ipv6
# (390) * Compute and join the Solicited-Node multicast
# address [RFC4291] for the IPv6 address(es) associated with
# the virtual router.
# (395) * For each IPv6 address associated with the virtual
# router, send an unsolicited ND Neighbor Advertisement with
# the Router Flag (R) set, the Solicited Flag (S) unset, the
# Override flag (O) set, the target address set to the IPv6
# address of the virtual router, and the target link-layer
# address set to the virtual router MAC address.
def _become_backup(self):
self.logger.debug('become backup')
# RFC 3768 6.4.2 Backup
# - MUST NOT respond to ARP requests for the IP address(s)
# associated with the virtual router.
# - MUST discard packets with a destination link layer MAC address
# equal to the virtual router MAC address.
# - MUST NOT accept packets addressed to the IP address(es)
# associated with the virtual router.
#
# or
#
# RFC 5798 6.4.2 Backup
# (305) - If the protected IPvX address is an IPv4 address, then:
# (310) + MUST NOT respond to ARP requests for the IPv4
# address(es) associated with the virtual router.
# (315) - else // protected addr is IPv6
# (320) + MUST NOT respond to ND Neighbor Solicitation messages
# for the IPv6 address(es) associated with the virtual router.
# (325) + MUST NOT send ND Router Advertisement messages for the
# virtual router.
# (330) -endif // was protected addr IPv4?
# (335) - MUST discard packets with a destination link-layer MAC
# address equal to the virtual router MAC address.
# (340) - MUST NOT accept packets addressed to the IPvX address(es)
# associated with the virtual router.
def _shutdowned(self):
self.logger.debug('shutdowned')
@handler.set_ev_handler(vrrp_event.EventVRRPStateChanged)
def vrrp_state_changed_handler(self, ev):
old_state = ev.old_state
new_state = ev.new_state
self.logger.debug('sample router %s -> %s', old_state, new_state)
if new_state == vrrp_event.VRRP_STATE_MASTER:
if old_state == vrrp_event.VRRP_STATE_INITIALIZE:
self._initialized_to_master()
elif old_state == vrrp_event.VRRP_STATE_BACKUP:
self._become_master()
# RFC 3768 6.4.3
# - MUST respond to ARP requests for the IP address(es) associated
# with the virtual router.
# - MUST forward packets with a destination link layer MAC address
# equal to the virtual router MAC address.
# - MUST NOT accept packets addressed to the IP address(es)
# associated with the virtual router if it is not the IP address
# owner.
# - MUST accept packets addressed to the IP address(es) associated
# with the virtual router if it is the IP address owner.
#
# or
#
# RFC5798 6.4.3
# (605) - If the protected IPvX address is an IPv4 address, then:
# (610) + MUST respond to ARP requests for the IPv4 address(es)
# associated with the virtual router.
# (615) - else // ipv6
# (620) + MUST be a member of the Solicited-Node multicast
# address for the IPv6 address(es) associated with the virtual
# router.
# (625) + MUST respond to ND Neighbor Solicitation message for
# the IPv6 address(es) associated with the virtual router.
# (630) ++ MUST send ND Router Advertisements for the virtual
# router.
# (635) ++ If Accept_Mode is False: MUST NOT drop IPv6 Neighbor
# Solicitations and Neighbor Advertisements.
# (640) +-endif // ipv4?
# (645) - MUST forward packets with a destination link-layer MAC
# address equal to the virtual router MAC address.
# (650) - MUST accept packets addressed to the IPvX address(es)
# associated with the virtual router if it is the IPvX address
# owner or if Accept_Mode is True. Otherwise, MUST NOT accept
# these packets.
elif new_state == vrrp_event.VRRP_STATE_BACKUP:
self._become_backup()
elif new_state == vrrp_event.VRRP_STATE_INITIALIZE:
if old_state is None:
self._initialized()
else:
self._shutdowned()
else:
raise ValueError('invalid vrrp state %s' % new_state)
class RouterIPV4(RouterBase):
def _garp_packet(self, ip_address):
# prepare garp packet
src_mac = vrrp.vrrp_ipv4_src_mac_address(self.config.vrid)
e = ethernet.ethernet(mac_lib.BROADCAST_STR, src_mac,
ether.ETH_TYPE_ARP)
a = arp.arp_ip(arp.ARP_REQUEST, src_mac, ip_address,
mac_lib.DONTCARE_STR, ip_address)
p = packet.Packet()
p.add_protocol(e)
utils.may_add_vlan(p, self.interface.vlan_id)
p.add_protocol(a)
p.serialize()
return p
def __init__(self, *args, **kwargs):
super(RouterIPV4, self).__init__(*args, **kwargs)
assert not self.config.is_ipv6
self.garp_packets = [self._garp_packet(ip_address)
for ip_address in self.config.ip_addresses]
def _send_garp(self):
self.logger.debug('_send_garp')
for garp_packet in self.garp_packets:
self._transmit(garp_packet.data)
def _arp_reply_packet(self, arp_req_sha, arp_req_spa, arp_req_tpa):
if not (arp_req_tpa in self.config.ip_addresses or
arp_req_tpa == self.config.primary_ip_address):
return None
src_mac = vrrp.vrrp_ipv4_src_mac_address(self.config.vrid)
e = ethernet.ethernet(arp_req_sha, src_mac, ether.ETH_TYPE_ARP)
a = arp.arp_ip(arp.ARP_REPLY, src_mac, arp_req_tpa,
arp_req_sha, arp_req_spa)
p = packet.Packet()
p.add_protocol(e)
utils.may_add_vlan(p, self.interface.vlan_id)
p.add_protocol(a)
p.serialize()
self._transmit(p.data)
def _arp_process(self, data):
dst_mac = vrrp.vrrp_ipv4_src_mac_address(self.config.vrid)
arp_sha = None
arp_spa = None
arp_tpa = None
p = packet.Packet(data)
for proto in p.protocols:
if isinstance(proto, ethernet.ethernet):
if proto.dst not in (mac_lib.BROADCAST_STR, dst_mac):
return None
ethertype = proto.ethertype
if not ((self.interface.vlan_id is None and
ethertype == ether.ETH_TYPE_ARP) or
(self.interface.vlan_id is not None and
ethertype == ether.ETH_TYPE_8021Q)):
return None
elif isinstance(proto, vlan.vlan):
if (proto.vid != self.interface.vlan_id or
proto.ethertype != ether.ETH_TYPE_ARP):
return None
elif isinstance(proto, arp.arp):
if (proto.hwtype != arp.ARP_HW_TYPE_ETHERNET or
proto.proto != ether.ETH_TYPE_IP or
proto.hlen != 6 or proto.plen != 4 or
proto.opcode != arp.ARP_REQUEST or
proto.dst_mac != dst_mac):
return None
arp_sha = proto.src_mac
arp_spa = proto.src_ip
arp_tpa = proto.dst_ip
break
if arp_sha is None or arp_spa is None or arp_tpa is None:
self.logger.debug('malformed arp request? arp_sha %s arp_spa %s',
arp_sha, arp_spa)
return None
self._arp_reply_packet(arp_sha, arp_spa, arp_tpa)
class RouterIPV4Linux(RouterIPV4):
def __init__(self, *args, **kwargs):
super(RouterIPV4Linux, self).__init__(*args, **kwargs)
assert isinstance(self.interface,
vrrp_event.VRRPInterfaceNetworkDevice)
self.__is_master = False
self._arp_thread = None
def start(self):
self._disable_router()
super(RouterIPV4Linux, self).start()
def _initialized_to_master(self):
self.logger.debug('initialized to master')
self._master()
def _become_master(self):
self.logger.debug('become master')
self._master()
def _master(self):
self.__is_master = True
self._enable_router()
self._send_garp()
def _become_backup(self):
self.logger.debug('become backup')
self.__is_master = False
self._disable_router()
def _shutdowned(self):
# When VRRP functionality is disabled, what to do?
# should we also exit? or continue to route packets?
self._disable_router()
def _arp_loop_socket(self, packet_socket):
while True:
try:
buf = packet_socket.recv(1500)
except socket.timeout:
continue
self._arp_process(buf)
def _arp_loop(self):
try:
with contextlib.closing(
socket.socket(
socket.AF_PACKET, socket.SOCK_RAW,
socket.htons(ether.ETH_TYPE_ARP))) as packet_socket:
packet_socket.bind((self.interface.device_name,
socket.htons(ether.ETH_TYPE_ARP),
socket.PACKET_BROADCAST,
arp.ARP_HW_TYPE_ETHERNET,
mac_lib.BROADCAST))
self._arp_loop_socket(packet_socket)
except greenlet.GreenletExit:
# suppress thread.kill exception
pass
def _enable_router(self):
if self._arp_thread is None:
self._arp_thread = hub.spawn(self._arp_loop)
# TODO: implement real routing logic
self.logger.debug('TODO:_enable_router')
def _disable_router(self):
if self._arp_thread is not None:
self._arp_thread.kill()
hub.joinall([self._arp_thread])
self._arp_thread = None
# TODO: implement real routing logic
self.logger.debug('TODO:_disable_router')
class RouterIPV4OpenFlow(RouterIPV4):
OFP_VERSIONS = [ofproto_v1_2.OFP_VERSION]
# it must be that
# _DROP_PRIORITY < monitor.VRRPInterfaceMonitorOpenFlow._PRIORITY or
# _DROP_TABLE > monitor.VRRPInterfaceMonitorOpenFlow._TABLE
# to gurantee that VRRP packets are send to controller
_DROP_TABLE = 0
_DROP_PRIORITY = 0x8000 / 2
# it must be that
# _ARP_PRIORITY < _DROP_PRIORITY or
# _ARP_TABLE > _DROP_TABLE
# to gurantee that responding arp can be disabled
_ARP_TABLE = 0
_ARP_PRIORITY = _DROP_PRIORITY // 2
# it must be that
# _ROUTEING_TABLE < _ARP_TABLE or
# _ROUTING_TABLE > _ARP_TABLE
# to gurantee that routing can be disabled
_ROUTING_TABLE = 0
_ROUTING_PRIORITY = _ARP_PRIORITY // 2
def __init__(self, *args, **kwargs):
super(RouterIPV4OpenFlow, self).__init__(*args, **kwargs)
assert isinstance(self.interface, vrrp_event.VRRPInterfaceOpenFlow)
def _get_dp(self):
return utils.get_dp(self, self.interface.dpid)
def start(self):
dp = self._get_dp()
assert dp
self._uninstall_route_rule(dp)
self._uninstall_arp_rule(dp)
self._uninstall_drop_rule(dp)
self._install_drop_rule(dp)
self._install_arp_rule(dp)
self._install_route_rule(dp)
super(RouterIPV4OpenFlow, self).start()
def _initialized_to_master(self):
self.logger.debug('initialized to master')
self._master()
def _become_master(self):
self.logger.debug('become master')
self._master()
def _master(self):
dp = self._get_dp()
if dp is None:
return
self._uninstall_drop_rule(dp)
self._send_garp(dp)
def _become_backup(self):
self.logger.debug('become backup')
dp = self._get_dp()
if dp is None:
return
self._install_drop_rule(dp)
def _shutdowned(self):
dp = self._get_dp()
if dp is None:
return
# When VRRP functionality is disabled, what to do?
# should we also exit? or continue to route packets?
self._uninstall_route_rule(dp)
self._uninstall_arp_rule(dp)
self._uninstall_drop_rule(dp)
@handler.set_ev_cls(ofp_event.EventOFPPacketIn, handler.MAIN_DISPATCHER)
def packet_in_handler(self, ev):
msg = ev.msg
datapath = msg.datapath
ofproto = datapath.ofproto
# TODO: subscribe only the datapath that we route
dpid = datapath.dpid
if dpid != self.interface.dpid:
return
for field in msg.match.fields:
header = field.header
if header == ofproto.OXM_OF_IN_PORT:
if field.value != self.interface.port_no:
return
break
self._arp_process(msg.data)
def _drop_match(self, dp):
kwargs = {}
kwargs['in_port'] = self.interface.port_no
kwargs['eth_dst'] = vrrp.vrrp_ipv4_src_mac_address(self.config.vrid)
if self.interface.vlan_id is not None:
kwargs['vlan_vid'] = self.interface.vlan_id
return dp.ofproto_parser.OFPMatch(**kwargs)
def _install_drop_rule(self, dp):
match = self._drop_match(dp)
utils.dp_flow_mod(dp, self._DROP_TABLE, dp.ofproto.OFPFC_ADD,
self._DROP_PRIORITY, match, [])
def _uninstall_drop_rule(self, dp):
match = self._drop_match(dp)
utils.dp_flow_mod(dp, self._DROP_TABLE, dp.ofproto.OFPFC_DELETE_STRICT,
self._DROP_PRIORITY, match, [])
def _arp_match(self, dp):
kwargs = {}
kwargs['in_port'] = self.interface.port_no
kwargs['eth_dst'] = mac_lib.BROADCAST_STR
kwargs['eth_type'] = ether.ETH_TYPE_ARP
if self.interface.vlan_id is not None:
kwargs['vlan_vid'] = self.interface.vlan_id
kwargs['arp_op'] = arp.ARP_REQUEST
kwargs['arp_tpa'] = vrrp.vrrp_ipv4_src_mac_address(self.config.vrid)
return dp.ofproto_parser.OFPMatch(**kwargs)
def _install_arp_rule(self, dp):
ofproto = dp.ofproto
ofproto_parser = dp.ofproto_parser
match = self._arp_match(dp)
actions = [ofproto_parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
ofproto.OFPCML_NO_BUFFER)]
instructions = [ofproto_parser.OFPInstructionActions(
ofproto.OFPIT_APPLY_ACTIONS, actions)]
utils.dp_flow_mod(dp, self._ARP_TABLE, dp.fproto.OFPFC_ADD,
self._ARP_PRIORITY, match, instructions)
def _uninstall_arp_rule(self, dp):
match = self._arp_match(dp)
utils.dp_flow_mod(dp, self._ARP_TABLE, dp.fproto.OFPFC_DELETE_STRICT,
self._ARP_PRIORITY, match, [])
def _install_route_rule(self, dp):
# TODO: implement real routing logic
self.logger.debug('TODO:_install_router_rule')
def _uninstall_route_rule(self, dp):
# TODO: implement real routing logic
self.logger.debug('TODO:_uninstall_router_rule')
class RouterIPV6(RouterBase):
def __init__(self, *args, **kwargs):
super(RouterIPV6, self).__init__(*args, **kwargs)
assert self.config.is_ipv6
class RouterIPV6Linux(RouterIPV6):
def __init__(self, *args, **kwargs):
super(RouterIPV6Linux, self).__init__(*args, **kwargs)
assert isinstance(self.interface,
vrrp_event.VRRPInterfaceNetworkDevice)
# TODO: reader's home work
pass
class RouterIPV6OpenFlow(RouterIPV6):
def __init__(self, *args, **kwargs):
super(RouterIPV6OpenFlow, self).__init__(*args, **kwargs)
assert isinstance(self.interface, vrrp_event.VRRPInterfaceOpenFlow)
# TODO: reader's home work
pass