# vim: tabstop=4 shiftwidth=4 softtabstop=4 # Copyright 2012 OpenStack LLC # All Rights Reserved. # # 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 os import socket import uuid import eventlet import netaddr from quantum.agent.common import config from quantum.agent.linux import dhcp from quantum.agent.linux import interface from quantum.agent.linux import ip_lib from quantum.agent import rpc as agent_rpc from quantum.common import exceptions from quantum.common import topics from quantum import context from quantum.openstack.common import cfg from quantum.openstack.common import importutils from quantum.openstack.common import jsonutils from quantum.openstack.common import log as logging from quantum.openstack.common.rpc import proxy from quantum.openstack.common import uuidutils LOG = logging.getLogger(__name__) NS_PREFIX = 'qdhcp-' class DhcpAgent(object): OPTS = [ cfg.StrOpt('root_helper', default='sudo'), cfg.IntOpt('resync_interval', default=30), cfg.StrOpt('dhcp_driver', default='quantum.agent.linux.dhcp.Dnsmasq', help="The driver used to manage the DHCP server."), cfg.BoolOpt('use_namespaces', default=True, help="Allow overlapping IP.") ] def __init__(self, conf): self.needs_resync = False self.conf = conf self.cache = NetworkCache() self.dhcp_driver_cls = importutils.import_class(conf.dhcp_driver) ctx = context.get_admin_context_without_session() self.plugin_rpc = DhcpPluginApi(topics.PLUGIN, ctx) self.device_manager = DeviceManager(self.conf, self.plugin_rpc) self.notifications = agent_rpc.NotificationDispatcher() self.lease_relay = DhcpLeaseRelay(self.update_lease) def run(self): """Activate the DHCP agent.""" self.sync_state() self.periodic_resync() self.lease_relay.start() self.notifications.run_dispatch(self) def call_driver(self, action, network): """Invoke an action on a DHCP driver instance.""" if self.conf.use_namespaces: namespace = NS_PREFIX + network.id else: namespace = None try: # the Driver expects something that is duck typed similar to # the base models. driver = self.dhcp_driver_cls(self.conf, network, self.conf.root_helper, self.device_manager, namespace) getattr(driver, action)() return True except Exception, e: self.needs_resync = True LOG.exception('Unable to %s dhcp.' % action) def update_lease(self, network_id, ip_address, time_remaining): try: self.plugin_rpc.update_lease_expiration(network_id, ip_address, time_remaining) except: self.needs_resync = True LOG.exception(_('Unable to update lease')) def sync_state(self): """Sync the local DHCP state with Quantum.""" LOG.info(_('Synchronizing state')) known_networks = set(self.cache.get_network_ids()) try: active_networks = set(self.plugin_rpc.get_active_networks()) for deleted_id in known_networks - active_networks: self.disable_dhcp_helper(deleted_id) for network_id in active_networks: self.refresh_dhcp_helper(network_id) except: self.needs_resync = True LOG.exception(_('Unable to sync network state.')) def _periodic_resync_helper(self): """Resync the dhcp state at the configured interval.""" while True: eventlet.sleep(self.conf.resync_interval) if self.needs_resync: self.needs_resync = False self.sync_state() def periodic_resync(self): """Spawn a thread to periodically resync the dhcp state.""" eventlet.spawn(self._periodic_resync_helper) def enable_dhcp_helper(self, network_id): """Enable DHCP for a network that meets enabling criteria.""" try: network = self.plugin_rpc.get_network_info(network_id) except: self.needs_resync = True LOG.exception(_('Network %s RPC info call failed.') % network_id) return if not network.admin_state_up: return for subnet in network.subnets: if subnet.enable_dhcp: if self.call_driver('enable', network): self.cache.put(network) break def disable_dhcp_helper(self, network_id): """Disable DHCP for a network known to the agent.""" network = self.cache.get_network_by_id(network_id) if network: if self.call_driver('disable', network): self.cache.remove(network) def refresh_dhcp_helper(self, network_id): """Refresh or disable DHCP for a network depending on the current state of the network. """ old_network = self.cache.get_network_by_id(network_id) if not old_network: # DHCP current not running for network. return self.enable_dhcp_helper(network_id) try: network = self.plugin_rpc.get_network_info(network_id) except: self.needs_resync = True LOG.exception(_('Network %s RPC info call failed.') % network_id) return old_cidrs = set(s.cidr for s in old_network.subnets if s.enable_dhcp) new_cidrs = set(s.cidr for s in network.subnets if s.enable_dhcp) if new_cidrs and old_cidrs == new_cidrs: self.call_driver('reload_allocations', network) self.cache.put(network) elif new_cidrs: if self.call_driver('restart', network): self.cache.put(network) else: self.disable_dhcp_helper(network.id) def network_create_end(self, payload): """Handle the network.create.end notification event.""" network_id = payload['network']['id'] self.enable_dhcp_helper(network_id) def network_update_end(self, payload): """Handle the network.update.end notification event.""" network_id = payload['network']['id'] if payload['network']['admin_state_up']: self.enable_dhcp_helper(network_id) else: self.disable_dhcp_helper(network_id) def network_delete_end(self, payload): """Handle the network.delete.end notification event.""" self.disable_dhcp_helper(payload['network_id']) def subnet_update_end(self, payload): """Handle the subnet.update.end notification event.""" network_id = payload['subnet']['network_id'] self.refresh_dhcp_helper(network_id) # Use the update handler for the subnet create event. subnet_create_end = subnet_update_end def subnet_delete_end(self, payload): """Handle the subnet.delete.end notification event.""" subnet_id = payload['subnet_id'] network = self.cache.get_network_by_subnet_id(subnet_id) if network: self.refresh_dhcp_helper(network.id) def port_update_end(self, payload): """Handle the port.update.end notification event.""" port = DictModel(payload['port']) network = self.cache.get_network_by_id(port.network_id) if network: self.cache.put_port(port) self.call_driver('reload_allocations', network) # Use the update handler for the port create event. port_create_end = port_update_end def port_delete_end(self, payload): """Handle the port.delete.end notification event.""" port = self.cache.get_port_by_id(payload['port_id']) if port: network = self.cache.get_network_by_id(port.network_id) self.cache.remove_port(port) self.call_driver('reload_allocations', network) class DhcpPluginApi(proxy.RpcProxy): """Agent side of the dhcp rpc API. API version history: 1.0 - Initial version. """ BASE_RPC_API_VERSION = '1.0' def __init__(self, topic, context): super(DhcpPluginApi, self).__init__( topic=topic, default_version=self.BASE_RPC_API_VERSION) self.context = context self.host = socket.gethostname() def get_active_networks(self): """Make a remote process call to retrieve the active networks.""" return self.call(self.context, self.make_msg('get_active_networks', host=self.host), topic=self.topic) def get_network_info(self, network_id): """Make a remote process call to retrieve network info.""" return DictModel(self.call(self.context, self.make_msg('get_network_info', network_id=network_id, host=self.host), topic=self.topic)) def get_dhcp_port(self, network_id, device_id): """Make a remote process call to create the dhcp port.""" return DictModel(self.call(self.context, self.make_msg('get_dhcp_port', network_id=network_id, device_id=device_id, host=self.host), topic=self.topic)) def release_dhcp_port(self, network_id, device_id): """Make a remote process call to release the dhcp port.""" return self.call(self.context, self.make_msg('release_dhcp_port', network_id=network_id, device_id=device_id, host=self.host), topic=self.topic) def release_port_fixed_ip(self, network_id, device_id, subnet_id): """Make a remote process call to release a fixed_ip on the port.""" return self.call(self.context, self.make_msg('release_port_fixed_ip', network_id=network_id, subnet_id=subnet_id, device_id=device_id, host=self.host), topic=self.topic) def update_lease_expiration(self, network_id, ip_address, lease_remaining): """Make a remote process call to update the ip lease expiration.""" self.cast(self.context, self.make_msg('update_lease_expiration', network_id=network_id, ip_address=ip_address, lease_remaining=lease_remaining, host=self.host), topic=self.topic) class NetworkCache(object): """Agent cache of the current network state.""" def __init__(self): self.cache = {} self.subnet_lookup = {} self.port_lookup = {} def get_network_ids(self): return self.cache.keys() def get_network_by_id(self, network_id): return self.cache.get(network_id) def get_network_by_subnet_id(self, subnet_id): return self.cache.get(self.subnet_lookup.get(subnet_id)) def get_network_by_port_id(self, port_id): return self.cache.get(self.port_lookup.get(port_id)) def put(self, network): if network.id in self.cache: self.remove(self.cache[network.id]) self.cache[network.id] = network for subnet in network.subnets: self.subnet_lookup[subnet.id] = network.id for port in network.ports: self.port_lookup[port.id] = network.id def remove(self, network): del self.cache[network.id] for subnet in network.subnets: del self.subnet_lookup[subnet.id] for port in network.ports: del self.port_lookup[port.id] def put_port(self, port): network = self.get_network_by_id(port.network_id) for index in range(len(network.ports)): if network.ports[index].id == port.id: network.ports[index] = port break else: network.ports.append(port) self.port_lookup[port.id] = network.id def remove_port(self, port): network = self.get_network_by_port_id(port.id) for index in range(len(network.ports)): if network.ports[index] == port: del network.ports[index] del self.port_lookup[port.id] break def get_port_by_id(self, port_id): network = self.get_network_by_port_id(port_id) if network: for port in network.ports: if port.id == port_id: return port class DeviceManager(object): OPTS = [ cfg.StrOpt('admin_user'), cfg.StrOpt('admin_password'), cfg.StrOpt('admin_tenant_name'), cfg.StrOpt('auth_url'), cfg.StrOpt('auth_strategy', default='keystone', help=_("The type of authentication to use")), cfg.StrOpt('auth_region'), cfg.StrOpt('interface_driver', help="The driver used to manage the virtual interface.") ] def __init__(self, conf, plugin): self.conf = conf self.plugin = plugin if not conf.interface_driver: LOG.error(_('You must specify an interface driver')) self.driver = importutils.import_object(conf.interface_driver, conf) def get_interface_name(self, network, port=None): """Return interface(device) name for use by the DHCP process.""" if not port: device_id = self.get_device_id(network) port = self.plugin.get_dhcp_port(network.id, device_id) return self.driver.get_device_name(port) def get_device_id(self, network): """Return a unique DHCP device ID for this host on the network.""" # There could be more than one dhcp server per network, so create # a device id that combines host and network ids host_uuid = uuid.uuid5(uuid.NAMESPACE_DNS, socket.gethostname()) return 'dhcp%s-%s' % (host_uuid, network.id) def setup(self, network, reuse_existing=False): """Create and initialize a device for network's DHCP on this host.""" device_id = self.get_device_id(network) port = self.plugin.get_dhcp_port(network.id, device_id) interface_name = self.get_interface_name(network, port) if self.conf.use_namespaces: namespace = NS_PREFIX + network.id else: namespace = None if ip_lib.device_exists(interface_name, self.conf.root_helper, namespace): if not reuse_existing: raise exceptions.PreexistingDeviceFailure( dev_name=interface_name) LOG.debug(_('Reusing existing device: %s.') % interface_name) else: self.driver.plug(network.id, port.id, interface_name, port.mac_address, namespace=namespace) ip_cidrs = [] for fixed_ip in port.fixed_ips: subnet = fixed_ip.subnet net = netaddr.IPNetwork(subnet.cidr) ip_cidr = '%s/%s' % (fixed_ip.ip_address, net.prefixlen) ip_cidrs.append(ip_cidr) self.driver.init_l3(interface_name, ip_cidrs, namespace=namespace) # ensure that the dhcp interface is first in the list if namespace is None: device = ip_lib.IPDevice(interface_name, self.conf.root_helper) device.route.pullup_route(interface_name) return interface_name def destroy(self, network, device_name): """Destroy the device used for the network's DHCP on this host.""" if self.conf.use_namespaces: namespace = NS_PREFIX + network.id else: namespace = None self.driver.unplug(device_name, namespace=namespace) self.plugin.release_dhcp_port(network.id, self.get_device_id(network)) class DictModel(object): """Convert dict into an object that provides attribute access to values.""" def __init__(self, d): for key, value in d.iteritems(): if isinstance(value, list): value = [DictModel(item) if isinstance(item, dict) else item for item in value] elif isinstance(value, dict): value = DictModel(value) setattr(self, key, value) class DhcpLeaseRelay(object): """UNIX domain socket server for processing lease updates. Network namespace isolation prevents the DHCP process from notifying Quantum directly. This class works around the limitation by using the domain socket to pass the information. This class handles message. receiving and then calls the callback method. """ OPTS = [ cfg.StrOpt('dhcp_lease_relay_socket', default='$state_path/dhcp/lease_relay', help='Location to DHCP lease relay UNIX domain socket') ] def __init__(self, lease_update_callback): self.callback = lease_update_callback dirname = os.path.dirname(cfg.CONF.dhcp_lease_relay_socket) if os.path.isdir(dirname): try: os.unlink(cfg.CONF.dhcp_lease_relay_socket) except OSError: if os.path.exists(cfg.CONF.dhcp_lease_relay_socket): raise else: os.makedirs(dirname, 0755) def _handler(self, client_sock, client_addr): """Handle incoming lease relay stream connection. This method will only read the first 1024 bytes and then close the connection. The limit exists to limit the impact of misbehaving clients. """ try: msg = client_sock.recv(1024) data = jsonutils.loads(msg) client_sock.close() network_id = data['network_id'] if not uuidutils.is_uuid_like(network_id): raise ValueError(_("Network ID %s is not a valid UUID") % (network_id)) ip_address = str(netaddr.IPAddress(data['ip_address'])) lease_remaining = int(data['lease_remaining']) self.callback(network_id, ip_address, lease_remaining) except ValueError, e: LOG.warn(_('Unable to parse lease relay msg to dict.')) LOG.warn(_('Exception value: %s') % e) LOG.warn(_('Message representation: %s') % repr(msg)) except Exception, e: LOG.exception(_('Unable update lease. Exception')) def start(self): """Spawn a green thread to run the lease relay unix socket server.""" listener = eventlet.listen(cfg.CONF.dhcp_lease_relay_socket, family=socket.AF_UNIX) eventlet.spawn(eventlet.serve, listener, self._handler) def main(): eventlet.monkey_patch() cfg.CONF.register_opts(DhcpAgent.OPTS) cfg.CONF.register_opts(DeviceManager.OPTS) cfg.CONF.register_opts(DhcpLeaseRelay.OPTS) cfg.CONF.register_opts(dhcp.OPTS) cfg.CONF.register_opts(interface.OPTS) cfg.CONF(project='quantum') config.setup_logging(cfg.CONF) mgr = DhcpAgent(cfg.CONF) mgr.run()