# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Nicira Networks, Inc.
# 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.
# @author: Somik Behera, Nicira Networks, Inc.
# @author: Brad Hall, Nicira Networks, Inc.
# @author: Dan Wendlandt, Nicira Networks, Inc.
# @author: Dave Lapsley, Nicira Networks, Inc.
# @author: Aaron Rosen, Nicira Networks, Inc.
# @author: Bob Kukura, Red Hat, Inc.
# @author: Seetharama Ayyadevara, Freescale Semiconductor, Inc.

import sys

from oslo.config import cfg

from neutron.agent import securitygroups_rpc as sg_rpc
from neutron.api.rpc.agentnotifiers import dhcp_rpc_agent_api
from neutron.api.rpc.agentnotifiers import l3_rpc_agent_api
from neutron.api.v2 import attributes
from neutron.common import constants as q_const
from neutron.common import exceptions as q_exc
from neutron.common import rpc as q_rpc
from neutron.common import topics
from neutron.common import utils
from neutron.db import agents_db
from neutron.db import agentschedulers_db
from neutron.db import allowedaddresspairs_db as addr_pair_db
from neutron.db import db_base_plugin_v2
from neutron.db import dhcp_rpc_base
from neutron.db import external_net_db
from neutron.db import extradhcpopt_db
from neutron.db import extraroute_db
from neutron.db import l3_agentschedulers_db
from neutron.db import l3_gwmode_db
from neutron.db import l3_rpc_base
from neutron.db import portbindings_db
from neutron.db import quota_db  # noqa
from neutron.db import securitygroups_rpc_base as sg_db_rpc
from neutron.extensions import allowedaddresspairs as addr_pair
from neutron.extensions import extra_dhcp_opt as edo_ext
from neutron.extensions import portbindings
from neutron.extensions import providernet as provider
from neutron.extensions import nat
from neutron import manager
from neutron.openstack.common import importutils
from neutron.openstack.common import log as logging
from neutron.openstack.common import rpc
from neutron.openstack.common.rpc import proxy
from neutron.plugins.common import constants as svc_constants
from neutron.plugins.common import utils as plugin_utils
from neutron.plugins.openvswitch.common import config  # noqa
from neutron.plugins.openvswitch.common import constants
from neutron.plugins.openvswitch import ovs_db_v2


LOG = logging.getLogger(__name__)


class OVSRpcCallbacks(dhcp_rpc_base.DhcpRpcCallbackMixin,
                      l3_rpc_base.L3RpcCallbackMixin,
                      sg_db_rpc.SecurityGroupServerRpcCallbackMixin):

    # history
    #   1.0 Initial version
    #   1.1 Support Security Group RPC

    RPC_API_VERSION = '1.1'

    def __init__(self, notifier, tunnel_type):
        self.notifier = notifier
        self.tunnel_type = tunnel_type

    def create_rpc_dispatcher(self):
        '''Get the rpc dispatcher for this manager.

        If a manager would like to set an rpc API version, or support more than
        one class as the target of rpc messages, override this method.
        '''
        return q_rpc.PluginRpcDispatcher([self,
                                          agents_db.AgentExtRpcCallback()])

    @classmethod
    def get_port_from_device(cls, device):
        port = ovs_db_v2.get_port_from_device(device)
        if port:
            port['device'] = device
        return port

    def get_device_details(self, rpc_context, **kwargs):
        """Agent requests device details."""
        agent_id = kwargs.get('agent_id')
        device = kwargs.get('device')
        LOG.debug(_("Device %(device)s details requested from %(agent_id)s"),
                  {'device': device, 'agent_id': agent_id})
        port = ovs_db_v2.get_port(device)
        if port:
            binding = ovs_db_v2.get_network_binding(None, port['network_id'])
            entry = {'device': device,
                     'network_id': port['network_id'],
                     'port_id': port['id'],
                     'admin_state_up': port['admin_state_up'],
                     'network_type': binding.network_type,
                     'segmentation_id': binding.segmentation_id,
                     'physical_network': binding.physical_network}
            new_status = (q_const.PORT_STATUS_ACTIVE if port['admin_state_up']
                          else q_const.PORT_STATUS_DOWN)
            if port['status'] != new_status:
                ovs_db_v2.set_port_status(port['id'], new_status)
        else:
            entry = {'device': device}
            LOG.debug(_("%s can not be found in database"), device)
        return entry

    def update_device_down(self, rpc_context, **kwargs):
        """Device no longer exists on agent."""
        agent_id = kwargs.get('agent_id')
        device = kwargs.get('device')
        host = kwargs.get('host')
        port = ovs_db_v2.get_port(device)
        LOG.debug(_("Device %(device)s no longer exists on %(agent_id)s"),
                  {'device': device, 'agent_id': agent_id})
        if port:
            entry = {'device': device,
                     'exists': True}
            plugin = manager.NeutronManager.get_plugin()
            if (host and
                not plugin.get_port_host(rpc_context, port['id']) == host):
                LOG.debug(_("Device %(device)s not bound to the"
                            " agent host %(host)s"),
                          {'device': device, 'host': host})
            elif port['status'] != q_const.PORT_STATUS_DOWN:
                # Set port status to DOWN
                ovs_db_v2.set_port_status(port['id'],
                                          q_const.PORT_STATUS_DOWN)
        else:
            entry = {'device': device,
                     'exists': False}
            LOG.debug(_("%s can not be found in database"), device)
        return entry

    def update_device_up(self, rpc_context, **kwargs):
        """Device is up on agent."""
        agent_id = kwargs.get('agent_id')
        device = kwargs.get('device')
        host = kwargs.get('host')
        port = ovs_db_v2.get_port(device)
        LOG.debug(_("Device %(device)s up on %(agent_id)s"),
                  {'device': device, 'agent_id': agent_id})
        plugin = manager.NeutronManager.get_plugin()
        if port:
            if (host and
                not plugin.get_port_host(rpc_context, port['id']) == host):
                LOG.debug(_("Device %(device)s not bound to the"
                            " agent host %(host)s"),
                          {'device': device, 'host': host})
                return
            elif port['status'] != q_const.PORT_STATUS_ACTIVE:
                ovs_db_v2.set_port_status(port['id'],
                                          q_const.PORT_STATUS_ACTIVE)
        else:
            LOG.debug(_("%s can not be found in database"), device)

    def tunnel_sync(self, rpc_context, **kwargs):
        """Update new tunnel.

        Updates the datbase with the tunnel IP. All listening agents will also
        be notified about the new tunnel IP.
        """
        tunnel_ip = kwargs.get('tunnel_ip')
        # Update the database with the IP
        tunnel = ovs_db_v2.add_tunnel_endpoint(tunnel_ip)
        tunnels = ovs_db_v2.get_tunnel_endpoints()
        entry = dict()
        entry['tunnels'] = tunnels
        # Notify all other listening agents
        self.notifier.tunnel_update(rpc_context, tunnel.ip_address,
                                    tunnel.id, self.tunnel_type)
        # Return the list of tunnels IP's to the agent
        return entry


class AgentNotifierApi(proxy.RpcProxy,
                       sg_rpc.SecurityGroupAgentRpcApiMixin):
    '''Agent side of the openvswitch rpc API.

    API version history:
        1.0 - Initial version.

    '''

    BASE_RPC_API_VERSION = '1.0'

    def __init__(self, topic):
        super(AgentNotifierApi, self).__init__(
            topic=topic, default_version=self.BASE_RPC_API_VERSION)
        self.topic_network_delete = topics.get_topic_name(topic,
                                                          topics.NETWORK,
                                                          topics.DELETE)
        self.topic_port_update = topics.get_topic_name(topic,
                                                       topics.PORT,
                                                       topics.UPDATE)
        self.topic_tunnel_update = topics.get_topic_name(topic,
                                                         constants.TUNNEL,
                                                         topics.UPDATE)

    def network_delete(self, context, network_id):
        self.fanout_cast(context,
                         self.make_msg('network_delete',
                                       network_id=network_id),
                         topic=self.topic_network_delete)

    def port_update(self, context, port, network_type, segmentation_id,
                    physical_network):
        self.fanout_cast(context,
                         self.make_msg('port_update',
                                       port=port,
                                       network_type=network_type,
                                       segmentation_id=segmentation_id,
                                       physical_network=physical_network),
                         topic=self.topic_port_update)

    def tunnel_update(self, context, tunnel_ip, tunnel_id, tunnel_type):
        self.fanout_cast(context,
                         self.make_msg('tunnel_update',
                                       tunnel_ip=tunnel_ip,
                                       tunnel_id=tunnel_id,
                                       tunnel_type=tunnel_type),
                         topic=self.topic_tunnel_update)


class OVSNeutronPluginV2(db_base_plugin_v2.NeutronDbPluginV2,
                         external_net_db.External_net_db_mixin,
                         extraroute_db.ExtraRoute_db_mixin,
                         l3_gwmode_db.L3_NAT_db_mixin,
                         sg_db_rpc.SecurityGroupServerRpcMixin,
                         l3_agentschedulers_db.L3AgentSchedulerDbMixin,
                         agentschedulers_db.DhcpAgentSchedulerDbMixin,
                         portbindings_db.PortBindingMixin,
                         extradhcpopt_db.ExtraDhcpOptMixin,
                         addr_pair_db.AllowedAddressPairsMixin):

    """Implement the Neutron abstractions using Open vSwitch.

    Depending on whether tunneling is enabled, either a GRE, VXLAN tunnel or
    a new VLAN is created for each network. An agent is relied upon to
    perform the actual OVS configuration on each host.

    The provider extension is also supported. As discussed in
    https://bugs.launchpad.net/neutron/+bug/1023156, this class could
    be simplified, and filtering on extended attributes could be
    handled, by adding support for extended attributes to the
    NeutronDbPluginV2 base class. When that occurs, this class should
    be updated to take advantage of it.

    The port binding extension enables an external application relay
    information to and from the plugin.
    """

    # This attribute specifies whether the plugin supports or not
    # bulk/pagination/sorting operations. Name mangling is used in
    # order to ensure it is qualified by class
    __native_bulk_support = True
    __native_pagination_support = True
    __native_sorting_support = True

    _supported_extension_aliases = ["provider", "external-net", "router",
                                    "ext-gw-mode", "binding", "quotas",
                                    "security-group", "agent", "extraroute",
                                    "l3_agent_scheduler",
                                    "dhcp_agent_scheduler",
                                    "extra_dhcp_opt",
                                    "allowed-address-pairs",
                                    "nat"]

    @property
    def supported_extension_aliases(self):
        if not hasattr(self, '_aliases'):
            aliases = self._supported_extension_aliases[:]
            sg_rpc.disable_security_group_extension_if_noop_driver(aliases)
            self._aliases = aliases
        return self._aliases

    def __init__(self, configfile=None):
        self.base_binding_dict = {
            portbindings.VIF_TYPE: portbindings.VIF_TYPE_OVS,
            portbindings.CAPABILITIES: {
                portbindings.CAP_PORT_FILTER:
                'security-group' in self.supported_extension_aliases}}
        ovs_db_v2.initialize()
        self._parse_network_vlan_ranges()
        ovs_db_v2.sync_vlan_allocations(self.network_vlan_ranges)
        self.tenant_network_type = cfg.CONF.OVS.tenant_network_type
        if self.tenant_network_type not in [constants.TYPE_LOCAL,
                                            constants.TYPE_VLAN,
                                            constants.TYPE_GRE,
                                            constants.TYPE_VXLAN,
                                            constants.TYPE_NONE]:
            LOG.error(_("Invalid tenant_network_type: %s. "
                      "Server terminated!"),
                      self.tenant_network_type)
            sys.exit(1)
        self.enable_tunneling = cfg.CONF.OVS.enable_tunneling
        self.tunnel_type = None
        if self.enable_tunneling:
            self.tunnel_type = cfg.CONF.OVS.tunnel_type or constants.TYPE_GRE
        elif cfg.CONF.OVS.tunnel_type:
            self.tunnel_type = cfg.CONF.OVS.tunnel_type
            self.enable_tunneling = True
        self.tunnel_id_ranges = []
        if self.enable_tunneling:
            self._parse_tunnel_id_ranges()
            ovs_db_v2.sync_tunnel_allocations(self.tunnel_id_ranges)
        elif self.tenant_network_type in constants.TUNNEL_NETWORK_TYPES:
            LOG.error(_("Tunneling disabled but tenant_network_type is '%s'. "
                      "Server terminated!"), self.tenant_network_type)
            sys.exit(1)
        self.setup_rpc()
        self.network_scheduler = importutils.import_object(
            cfg.CONF.network_scheduler_driver
        )
        self.router_scheduler = importutils.import_object(
            cfg.CONF.router_scheduler_driver
        )

    def setup_rpc(self):
        # RPC support
        self.service_topics = {svc_constants.CORE: topics.PLUGIN,
                               svc_constants.L3_ROUTER_NAT: topics.L3PLUGIN}
        self.conn = rpc.create_connection(new=True)
        self.notifier = AgentNotifierApi(topics.AGENT)
        self.agent_notifiers[q_const.AGENT_TYPE_DHCP] = (
            dhcp_rpc_agent_api.DhcpAgentNotifyAPI()
        )
        self.agent_notifiers[q_const.AGENT_TYPE_L3] = (
            l3_rpc_agent_api.L3AgentNotify
        )
        self.callbacks = OVSRpcCallbacks(self.notifier, self.tunnel_type)
        self.dispatcher = self.callbacks.create_rpc_dispatcher()
        for svc_topic in self.service_topics.values():
            self.conn.create_consumer(svc_topic, self.dispatcher, fanout=False)
        # Consume from all consumers in a thread
        self.conn.consume_in_thread()

    def _parse_network_vlan_ranges(self):
        try:
            self.network_vlan_ranges = plugin_utils.parse_network_vlan_ranges(
                cfg.CONF.OVS.network_vlan_ranges)
        except Exception as ex:
            LOG.error(_("%s. Server terminated!"), ex)
            sys.exit(1)
        LOG.info(_("Network VLAN ranges: %s"), self.network_vlan_ranges)

    def _parse_tunnel_id_ranges(self):
        for entry in cfg.CONF.OVS.tunnel_id_ranges:
            entry = entry.strip()
            try:
                tun_min, tun_max = entry.split(':')
                self.tunnel_id_ranges.append((int(tun_min), int(tun_max)))
            except ValueError as ex:
                LOG.error(_("Invalid tunnel ID range: "
                            "'%(range)s' - %(e)s. Server terminated!"),
                          {'range': entry, 'e': ex})
                sys.exit(1)
        LOG.info(_("Tunnel ID ranges: %s"), self.tunnel_id_ranges)

    def _extend_network_dict_provider(self, context, network):
        binding = ovs_db_v2.get_network_binding(context.session,
                                                network['id'])
        network[provider.NETWORK_TYPE] = binding.network_type
        if binding.network_type in constants.TUNNEL_NETWORK_TYPES:
            network[provider.PHYSICAL_NETWORK] = None
            network[provider.SEGMENTATION_ID] = binding.segmentation_id
        elif binding.network_type == constants.TYPE_FLAT:
            network[provider.PHYSICAL_NETWORK] = binding.physical_network
            network[provider.SEGMENTATION_ID] = None
        elif binding.network_type == constants.TYPE_VLAN:
            network[provider.PHYSICAL_NETWORK] = binding.physical_network
            network[provider.SEGMENTATION_ID] = binding.segmentation_id
        elif binding.network_type == constants.TYPE_LOCAL:
            network[provider.PHYSICAL_NETWORK] = None
            network[provider.SEGMENTATION_ID] = None

    def _process_provider_create(self, context, attrs):
        network_type = attrs.get(provider.NETWORK_TYPE)
        physical_network = attrs.get(provider.PHYSICAL_NETWORK)
        segmentation_id = attrs.get(provider.SEGMENTATION_ID)

        network_type_set = attributes.is_attr_set(network_type)
        physical_network_set = attributes.is_attr_set(physical_network)
        segmentation_id_set = attributes.is_attr_set(segmentation_id)

        if not (network_type_set or physical_network_set or
                segmentation_id_set):
            return (None, None, None)

        if not network_type_set:
            msg = _("provider:network_type required")
            raise q_exc.InvalidInput(error_message=msg)
        elif network_type == constants.TYPE_FLAT:
            if segmentation_id_set:
                msg = _("provider:segmentation_id specified for flat network")
                raise q_exc.InvalidInput(error_message=msg)
            else:
                segmentation_id = constants.FLAT_VLAN_ID
        elif network_type == constants.TYPE_VLAN:
            if not segmentation_id_set:
                msg = _("provider:segmentation_id required")
                raise q_exc.InvalidInput(error_message=msg)
            if not utils.is_valid_vlan_tag(segmentation_id):
                msg = (_("provider:segmentation_id out of range "
                         "(%(min_id)s through %(max_id)s)") %
                       {'min_id': q_const.MIN_VLAN_TAG,
                        'max_id': q_const.MAX_VLAN_TAG})
                raise q_exc.InvalidInput(error_message=msg)
        elif network_type in constants.TUNNEL_NETWORK_TYPES:
            if not self.enable_tunneling:
                msg = _("%s networks are not enabled") % network_type
                raise q_exc.InvalidInput(error_message=msg)
            if physical_network_set:
                msg = _("provider:physical_network specified for %s "
                        "network") % network_type
                raise q_exc.InvalidInput(error_message=msg)
            else:
                physical_network = None
            if not segmentation_id_set:
                msg = _("provider:segmentation_id required")
                raise q_exc.InvalidInput(error_message=msg)
        elif network_type == constants.TYPE_LOCAL:
            if physical_network_set:
                msg = _("provider:physical_network specified for local "
                        "network")
                raise q_exc.InvalidInput(error_message=msg)
            else:
                physical_network = None
            if segmentation_id_set:
                msg = _("provider:segmentation_id specified for local "
                        "network")
                raise q_exc.InvalidInput(error_message=msg)
            else:
                segmentation_id = None
        else:
            msg = _("provider:network_type %s not supported") % network_type
            raise q_exc.InvalidInput(error_message=msg)

        if network_type in [constants.TYPE_VLAN, constants.TYPE_FLAT]:
            if physical_network_set:
                if physical_network not in self.network_vlan_ranges:
                    msg = _("Unknown provider:physical_network "
                            "%s") % physical_network
                    raise q_exc.InvalidInput(error_message=msg)
            elif 'default' in self.network_vlan_ranges:
                physical_network = 'default'
            else:
                msg = _("provider:physical_network required")
                raise q_exc.InvalidInput(error_message=msg)

        return (network_type, physical_network, segmentation_id)

    def create_network(self, context, network):
        (network_type, physical_network,
         segmentation_id) = self._process_provider_create(context,
                                                          network['network'])

        session = context.session
        #set up default security groups
        tenant_id = self._get_tenant_id_for_create(
            context, network['network'])
        self._ensure_default_security_group(context, tenant_id)

        with session.begin(subtransactions=True):
            if not network_type:
                # tenant network
                network_type = self.tenant_network_type
                if network_type == constants.TYPE_NONE:
                    raise q_exc.TenantNetworksDisabled()
                elif network_type == constants.TYPE_VLAN:
                    (physical_network,
                     segmentation_id) = ovs_db_v2.reserve_vlan(session)
                elif network_type in constants.TUNNEL_NETWORK_TYPES:
                    segmentation_id = ovs_db_v2.reserve_tunnel(session)
                # no reservation needed for TYPE_LOCAL
            else:
                # provider network
                if network_type in [constants.TYPE_VLAN, constants.TYPE_FLAT]:
                    ovs_db_v2.reserve_specific_vlan(session, physical_network,
                                                    segmentation_id)
                elif network_type in constants.TUNNEL_NETWORK_TYPES:
                    ovs_db_v2.reserve_specific_tunnel(session, segmentation_id)
                # no reservation needed for TYPE_LOCAL
            net = super(OVSNeutronPluginV2, self).create_network(context,
                                                                 network)
            ovs_db_v2.add_network_binding(session, net['id'], network_type,
                                          physical_network, segmentation_id)

            self._process_l3_create(context, net, network['network'])
            self._extend_network_dict_provider(context, net)
            # note - exception will rollback entire transaction
        LOG.debug(_("Created network: %s"), net['id'])
        return net

    def update_network(self, context, id, network):
        provider._raise_if_updates_provider_attributes(network['network'])

        session = context.session
        with session.begin(subtransactions=True):
            net = super(OVSNeutronPluginV2, self).update_network(context, id,
                                                                 network)
            self._process_l3_update(context, net, network['network'])
            self._extend_network_dict_provider(context, net)
        return net

    def delete_network(self, context, id):
        session = context.session
        with session.begin(subtransactions=True):
            binding = ovs_db_v2.get_network_binding(session, id)
            super(OVSNeutronPluginV2, self).delete_network(context, id)
            if binding.network_type in constants.TUNNEL_NETWORK_TYPES:
                ovs_db_v2.release_tunnel(session, binding.segmentation_id,
                                         self.tunnel_id_ranges)
            elif binding.network_type in [constants.TYPE_VLAN,
                                          constants.TYPE_FLAT]:
                ovs_db_v2.release_vlan(session, binding.physical_network,
                                       binding.segmentation_id,
                                       self.network_vlan_ranges)
            # the network_binding record is deleted via cascade from
            # the network record, so explicit removal is not necessary
        self.notifier.network_delete(context, id)

    def get_network(self, context, id, fields=None):
        session = context.session
        with session.begin(subtransactions=True):
            net = super(OVSNeutronPluginV2, self).get_network(context,
                                                              id, None)
            self._extend_network_dict_provider(context, net)
        return self._fields(net, fields)

    def get_networks(self, context, filters=None, fields=None,
                     sorts=None,
                     limit=None, marker=None, page_reverse=False):
        session = context.session
        with session.begin(subtransactions=True):
            nets = super(OVSNeutronPluginV2,
                         self).get_networks(context, filters, None, sorts,
                                            limit, marker, page_reverse)
            for net in nets:
                self._extend_network_dict_provider(context, net)

        return [self._fields(net, fields) for net in nets]

    def create_port(self, context, port):
        # Set port status as 'DOWN'. This will be updated by agent
        port['port']['status'] = q_const.PORT_STATUS_DOWN
        port_data = port['port']
        session = context.session
        with session.begin(subtransactions=True):
            self._ensure_default_security_group_on_port(context, port)
            sgids = self._get_security_groups_on_port(context, port)
            dhcp_opts = port['port'].get(edo_ext.EXTRADHCPOPTS, [])
            port = super(OVSNeutronPluginV2, self).create_port(context, port)
            self._process_portbindings_create_and_update(context,
                                                         port_data, port)
            self._process_port_create_security_group(context, port, sgids)
            self._process_port_create_extra_dhcp_opts(context, port,
                                                      dhcp_opts)
            port[addr_pair.ADDRESS_PAIRS] = (
                self._process_create_allowed_address_pairs(
                    context, port,
                    port_data.get(addr_pair.ADDRESS_PAIRS)))
        self.notify_security_groups_member_updated(context, port)
        return port

    def _extend_port_dict_nat(self, context, port):
        forward = ovs_db_v2.get_port_forwarding(context.session, port['id'])
        if forward:
            port[nat.FORWARD_PORTS] = forward
        else:
            port[nat.FORWARD_PORTS] = None

    def _process_nat_update(self, context, attrs, id):
        forward_ports = attrs.get(nat.FORWARD_PORTS)
        forward_ports_set = attributes.is_attr_set(forward_ports)

        if not forward_ports_set:
            return None

        # LOG.info("forward ports %s" % forward_ports)
        valid_protocols = ["tcp", "udp"]
        for entry in forward_ports:
            if not isinstance(entry, dict):
                msg = _("nat:forward_ports: must specify a list of dicts (ex: 'l4_protocol=tcp,l4_port=80')")
                raise q_exc.InvalidInput(error_message=msg)
            if not ("l4_protocol" in entry and "l4_port" in entry):
                msg = _("nat:forward_ports: dict is missing l4_protocol and l4_port (ex: 'l4_protocol=tcp,l4_port=80')")
                raise q_exc.InvalidInput(error_message=msg)
            if entry['l4_protocol'] not in valid_protocols:
                msg = _("nat:forward_ports: invalid protocol (only tcp and udp allowed)")
                raise q_exc.InvalidInput(error_message=msg)

            l4_port = entry['l4_port']
            if ":" in l4_port:
                try:
                    (first, last) = l4_port.split(":")
                    first = int(first)
                    last = int(last)
                except:
                    msg = _("nat:forward_ports: l4_port range must be integer:integer")
                    raise q_exc.InvalidInput(error_message=msg)
            else:
                try:
                    l4_port = int(l4_port)
                except:
                    msg = _("nat:forward_ports: l4_port must be an integer")
                    raise q_exc.InvalidInput(error_message=msg)

        return forward_ports

    def get_port(self, context, id, fields=None):
        session = context.session
        with session.begin(subtransactions=True):
            port = super(OVSNeutronPluginV2, self).get_port(context, id, None)
            self._extend_port_dict_nat(context, port)
        return self._fields(port, fields)

    def get_ports(self, context, filters=None, fields=None):
        session = context.session
        with session.begin(subtransactions=True):
            ports = super(OVSNeutronPluginV2, self).get_ports(context, filters,
                                                          None)
            for port in ports:
                self._extend_port_dict_nat(context, port)

        return [self._fields(port, fields) for port in ports]

    def update_port(self, context, id, port):
        forward_ports = self._process_nat_update(context, port['port'], id)

        session = context.session
        need_port_update_notify = False
        changed_fixed_ips = 'fixed_ips' in port['port']
        with session.begin(subtransactions=True):
            original_port = super(OVSNeutronPluginV2, self).get_port(
                context, id)
            updated_port = super(OVSNeutronPluginV2, self).update_port(
                context, id, port)
            if addr_pair.ADDRESS_PAIRS in port['port']:
                self._delete_allowed_address_pairs(context, id)
                self._process_create_allowed_address_pairs(
                    context, updated_port,
                    port['port'][addr_pair.ADDRESS_PAIRS])
                need_port_update_notify = True
            elif changed_fixed_ips:
                self._check_fixed_ips_and_address_pairs_no_overlap(
                    context, updated_port)

            if forward_ports:
                ovs_db_v2.clear_port_forwarding(session, updated_port['id'])
                ovs_db_v2.add_port_forwarding(session, updated_port['id'], forward_ports)
            self._extend_port_dict_nat(context, updated_port)

            need_port_update_notify |= self.update_security_group_on_port(
                context, id, port, original_port, updated_port)
            self._process_portbindings_create_and_update(context,
                                                         port['port'],
                                                         updated_port)
            need_port_update_notify |= self._update_extra_dhcp_opts_on_port(
                context, id, port, updated_port)

        need_port_update_notify |= self.is_security_group_member_updated(
            context, original_port, updated_port)
        if original_port['admin_state_up'] != updated_port['admin_state_up']:
            need_port_update_notify = True

        if need_port_update_notify:
            binding = ovs_db_v2.get_network_binding(None,
                                                    updated_port['network_id'])
            self.notifier.port_update(context, updated_port,
                                      binding.network_type,
                                      binding.segmentation_id,
                                      binding.physical_network)
        return updated_port

    def delete_port(self, context, id, l3_port_check=True):

        # if needed, check to see if this is a port owned by
        # and l3-router.  If so, we should prevent deletion.
        if l3_port_check:
            self.prevent_l3_port_deletion(context, id)

        session = context.session
        with session.begin(subtransactions=True):
            self.disassociate_floatingips(context, id)
            port = self.get_port(context, id)
            self._delete_port_security_group_bindings(context, id)
            super(OVSNeutronPluginV2, self).delete_port(context, id)

        self.notify_security_groups_member_updated(context, port)