# Copyright 2014 VMware, 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.

from distutils import version
import xml.etree.ElementTree as et

import netaddr

from neutron_lib.agent import topics
from neutron_lib.api.definitions import address_scope
from neutron_lib.api.definitions import agent as agent_apidef
from neutron_lib.api.definitions import allowedaddresspairs as addr_apidef
from neutron_lib.api.definitions import availability_zone as az_def
from neutron_lib.api.definitions import dvr as dvr_apidef
from neutron_lib.api.definitions import external_net as extnet_apidef
from neutron_lib.api.definitions import extra_dhcp_opt as ext_edo
from neutron_lib.api.definitions import extraroute
from neutron_lib.api.definitions import flavors as flavors_apidef
from neutron_lib.api.definitions import l3 as l3_apidef
from neutron_lib.api.definitions import l3_flavors
from neutron_lib.api.definitions import multiprovidernet as mpnet_apidef
from neutron_lib.api.definitions import network_availability_zone
from neutron_lib.api.definitions import port as port_def
from neutron_lib.api.definitions import port_security as psec
from neutron_lib.api.definitions import portbindings as pbin
from neutron_lib.api.definitions import provider_net as pnet
from neutron_lib.api.definitions import router_availability_zone
from neutron_lib.api.definitions import subnet as subnet_def
from neutron_lib.api.definitions import vlantransparent as vlan_apidef
from neutron_lib.api import extensions
from neutron_lib.api import validators
from neutron_lib.api.validators import availability_zone as az_validator
from neutron_lib.callbacks import events
from neutron_lib.callbacks import registry
from neutron_lib.callbacks import resources
from neutron_lib import constants
from neutron_lib import context as n_context
from neutron_lib.db import api as db_api
from neutron_lib.db import constants as db_const
from neutron_lib.db import resource_extend
from neutron_lib.db import utils as db_utils
from neutron_lib import exceptions as n_exc
from neutron_lib.exceptions import allowedaddresspairs as addr_exc
from neutron_lib.exceptions import flavors as flav_exc
from neutron_lib.exceptions import l3 as l3_exc
from neutron_lib.exceptions import multiprovidernet as mpnet_exc
from neutron_lib.exceptions import port_security as psec_exc
from neutron_lib.objects import registry as obj_reg
from neutron_lib.plugins import constants as plugin_const
from neutron_lib.plugins import directory
from neutron_lib.plugins import utils
from neutron_lib import rpc as n_rpc
from neutron_lib.services.qos import constants as qos_consts
from oslo_config import cfg
from oslo_log import log as logging
from oslo_serialization import jsonutils
from oslo_utils import excutils
from oslo_utils import netutils
from oslo_utils import uuidutils
from sqlalchemy.orm import exc as sa_exc

from neutron.api import extensions as neutron_extensions
from neutron.common import ipv6_utils
from neutron.common import utils as n_utils
from neutron.db import agents_db
from neutron.db import allowedaddresspairs_db as addr_pair_db
from neutron.db.availability_zone import router as router_az_db
from neutron.db import dns_db
from neutron.db import external_net_db
from neutron.db import extradhcpopt_db
from neutron.db import extraroute_db
from neutron.db import l3_db
from neutron.db import l3_gwmode_db
from neutron.db.models import l3 as l3_db_models
from neutron.db.models import securitygroup as securitygroup_model
from neutron.db import models_v2
from neutron.db import portsecurity_db
from neutron.db import securitygroups_db
from neutron.db import vlantransparent_db
from neutron.extensions import securitygroup as ext_sg
from neutron.quota import resource_registry
from neutron.services.flavors import flavors_plugin
from vmware_nsx.dvs import dvs
from vmware_nsx.services.qos.common import utils as qos_com_utils
from vmware_nsx.services.qos.nsx_v import driver as qos_driver
from vmware_nsx.services.qos.nsx_v import utils as qos_utils

import vmware_nsx
from vmware_nsx._i18n import _
from vmware_nsx.common import availability_zones as nsx_com_az
from vmware_nsx.common import config  # noqa
from vmware_nsx.common import exceptions as nsx_exc
from vmware_nsx.common import l3_rpc_agent_api
from vmware_nsx.common import locking
from vmware_nsx.common import managers as nsx_managers
from vmware_nsx.common import nsx_constants
from vmware_nsx.common import nsxv_constants
from vmware_nsx.common import utils as c_utils
from vmware_nsx.db import (
    extended_security_group_rule as extend_sg_rule)
from vmware_nsx.db import (
    routertype as rt_rtr)
from vmware_nsx.db import db as nsx_db
from vmware_nsx.db import extended_security_group as extended_secgroup
from vmware_nsx.db import maclearning as mac_db
from vmware_nsx.db import nsx_portbindings_db as pbin_db
from vmware_nsx.db import nsxv_db
from vmware_nsx.db import vnic_index_db
from vmware_nsx.extensions import (
    advancedserviceproviders as as_providers)
from vmware_nsx.extensions import (
    vnicindex as ext_vnic_idx)
from vmware_nsx.extensions import dhcp_mtu as ext_dhcp_mtu
from vmware_nsx.extensions import dns_search_domain as ext_dns_search_domain
from vmware_nsx.extensions import housekeeper as hk_ext
from vmware_nsx.extensions import maclearning as mac_ext
from vmware_nsx.extensions import nsxpolicy
from vmware_nsx.extensions import projectpluginmap
from vmware_nsx.extensions import providersecuritygroup as provider_sg
from vmware_nsx.extensions import routersize
from vmware_nsx.extensions import routertype
from vmware_nsx.extensions import secgroup_rule_local_ip_prefix
from vmware_nsx.extensions import securitygrouplogging as sg_logging
from vmware_nsx.extensions import securitygrouppolicy as sg_policy
from vmware_nsx.plugins.common.housekeeper import housekeeper
from vmware_nsx.plugins.common import plugin as nsx_plugin_common
from vmware_nsx.plugins.nsx import utils as tvd_utils
from vmware_nsx.plugins.nsx_v import availability_zones as nsx_az
from vmware_nsx.plugins.nsx_v import managers
from vmware_nsx.plugins.nsx_v import md_proxy as nsx_v_md_proxy
from vmware_nsx.plugins.nsx_v.vshield.common import (
    constants as vcns_const)
from vmware_nsx.plugins.nsx_v.vshield.common import (
    exceptions as vsh_exc)
from vmware_nsx.plugins.nsx_v.vshield import edge_firewall_driver
from vmware_nsx.plugins.nsx_v.vshield import edge_utils
from vmware_nsx.plugins.nsx_v.vshield import securitygroup_utils
from vmware_nsx.plugins.nsx_v.vshield import vcns_driver
from vmware_nsx.services.flowclassifier.nsx_v import utils as fc_utils
from vmware_nsx.services.fwaas.common import utils as fwaas_utils
from vmware_nsx.services.fwaas.nsx_v import fwaas_callbacks_v2
from vmware_nsx.services.lbaas.nsx_v.implementation import healthmon_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import l7policy_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import l7rule_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import listener_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import loadbalancer_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import member_mgr
from vmware_nsx.services.lbaas.nsx_v.implementation import pool_mgr
from vmware_nsx.services.lbaas.nsx_v import lbaas_common as lb_common
from vmware_nsx.services.lbaas.octavia import constants as oct_const
from vmware_nsx.services.lbaas.octavia import octavia_listener

LOG = logging.getLogger(__name__)
PORTGROUP_PREFIX = 'dvportgroup'
ROUTER_SIZE = routersize.ROUTER_SIZE
VALID_EDGE_SIZES = routersize.VALID_EDGE_SIZES

SUBNET_RULE_NAME = 'Subnet Rule'
DNAT_RULE_NAME = 'DNAT Rule'
ALLOCATION_POOL_RULE_NAME = 'Allocation Pool Rule'
NO_SNAT_RULE_NAME = 'No SNAT Rule'

UNSUPPORTED_RULE_NAMED_PROTOCOLS = [constants.PROTO_NAME_DCCP,
                                    constants.PROTO_NAME_PGM,
                                    constants.PROTO_NAME_VRRP,
                                    constants.PROTO_NAME_UDPLITE,
                                    constants.PROTO_NAME_EGP,
                                    constants.PROTO_NAME_IPIP,
                                    constants.PROTO_NAME_OSPF,
                                    constants.PROTO_NAME_IPV6_ROUTE,
                                    constants.PROTO_NAME_IPV6_ENCAP,
                                    constants.PROTO_NAME_IPV6_FRAG,
                                    constants.PROTO_NAME_IPV6_OPTS,
                                    constants.PROTO_NAME_IPV6_NONXT]
PROTOCOLS_SUPPORTING_PORTS = [constants.PROTO_NUM_TCP,
                              constants.PROTO_NUM_UDP,
                              constants.PROTO_NUM_ICMP,
                              constants.PROTO_NUM_IPV6_ICMP]


@resource_extend.has_resource_extenders
class NsxVPluginV2(addr_pair_db.AllowedAddressPairsMixin,
                   agents_db.AgentDbMixin,
                   nsx_plugin_common.NsxPluginBase,
                   rt_rtr.RouterType_mixin,
                   external_net_db.External_net_db_mixin,
                   extraroute_db.ExtraRoute_db_mixin,
                   extradhcpopt_db.ExtraDhcpOptMixin,
                   router_az_db.RouterAvailabilityZoneMixin,
                   l3_gwmode_db.L3_NAT_db_mixin,
                   pbin_db.NsxPortBindingMixin,
                   portsecurity_db.PortSecurityDbMixin,
                   extend_sg_rule.ExtendedSecurityGroupRuleMixin,
                   securitygroups_db.SecurityGroupDbMixin,
                   extended_secgroup.ExtendedSecurityGroupPropertiesMixin,
                   vnic_index_db.VnicIndexDbMixin,
                   dns_db.DNSDbMixin, nsxpolicy.NsxPolicyPluginBase,
                   vlantransparent_db.Vlantransparent_db_mixin,
                   nsx_com_az.NSXAvailabilityZonesPluginCommon,
                   mac_db.MacLearningDbMixin,
                   hk_ext.Housekeeper):

    supported_extension_aliases = [agent_apidef.ALIAS,
                                   addr_apidef.ALIAS,
                                   address_scope.ALIAS,
                                   pbin.ALIAS,
                                   ext_dns_search_domain.ALIAS,
                                   dvr_apidef.ALIAS,
                                   "ext-gw-mode",
                                   mpnet_apidef.ALIAS,
                                   psec.ALIAS,
                                   pnet.ALIAS,
                                   "quotas",
                                   extnet_apidef.ALIAS,
                                   ext_edo.ALIAS,
                                   extraroute.ALIAS,
                                   l3_apidef.ALIAS,
                                   "security-group",
                                   secgroup_rule_local_ip_prefix.ALIAS,
                                   sg_logging.ALIAS,
                                   routertype.ALIAS,
                                   routersize.ALIAS,
                                   ext_vnic_idx.ALIAS,
                                   as_providers.ALIAS,
                                   "subnet_allocation",
                                   az_def.ALIAS,
                                   network_availability_zone.ALIAS,
                                   router_availability_zone.ALIAS,
                                   l3_flavors.ALIAS,
                                   flavors_apidef.ALIAS,
                                   ext_dhcp_mtu.ALIAS,
                                   mac_ext.ALIAS,
                                   hk_ext.ALIAS,
                                   "port-security-groups-filtering"]

    __native_bulk_support = True
    __native_pagination_support = True
    __native_sorting_support = True

    @resource_registry.tracked_resources(
        network=models_v2.Network,
        port=models_v2.Port,
        subnet=models_v2.Subnet,
        subnetpool=models_v2.SubnetPool,
        security_group=securitygroup_model.SecurityGroup,
        security_group_rule=securitygroup_model.SecurityGroupRule,
        router=l3_db_models.Router,
        floatingip=l3_db_models.FloatingIP)
    def __init__(self):
        self._is_sub_plugin = tvd_utils.is_tvd_core_plugin()
        self.init_is_complete = False
        self.octavia_listener = None
        self.octavia_stats_collector = None
        self.housekeeper = None
        super(NsxVPluginV2, self).__init__()
        if self._is_sub_plugin:
            extension_drivers = cfg.CONF.nsx_tvd.nsx_v_extension_drivers
        else:
            extension_drivers = cfg.CONF.nsx_extension_drivers
        self._extension_manager = nsx_managers.ExtensionManager(
            extension_drivers=extension_drivers)
        # Bind the dummy L3 notifications
        self.l3_rpc_notifier = l3_rpc_agent_api.L3NotifyAPI()
        self._extension_manager.initialize()
        self.supported_extension_aliases.extend(
            self._extension_manager.extension_aliases())
        self.metadata_proxy_handler = None
        config.validate_nsxv_config_options()
        self._network_vlans = utils.parse_network_vlan_ranges(
            cfg.CONF.nsxv.network_vlan_ranges)
        neutron_extensions.append_api_extensions_path(
            [vmware_nsx.NSX_EXT_PATH])

        # This needs to be set prior to binding callbacks
        if cfg.CONF.nsxv.use_dvs_features:
            self._vcm = dvs.VCManager()
        else:
            self._vcm = None
        # Create the client to interface with the NSX-v
        _nsx_v_callbacks = edge_utils.NsxVCallbacks(self)
        self.nsx_v = vcns_driver.VcnsDriver(_nsx_v_callbacks)
        # Use the existing class instead of creating a new instance
        self.lbv2_driver = self.nsx_v
        # Ensure that edges do concurrency
        self._ensure_lock_operations()
        self._validate_nsx_version()
        # Configure aggregate publishing
        self._aggregate_publishing()
        # Configure edge reservations
        self._configure_reservations()
        self.edge_manager = edge_utils.EdgeManager(self.nsx_v, self)
        self.nsx_sg_utils = securitygroup_utils.NsxSecurityGroupUtils(
            self.nsx_v)
        self.init_availability_zones()
        self._validate_config()

        self._use_nsx_policies = False
        if cfg.CONF.nsxv.use_nsx_policies:
            if not c_utils.is_nsxv_version_6_2(self.nsx_v.vcns.get_version()):
                error = (_("NSX policies are not supported for version "
                           "%(ver)s.") %
                         {'ver': self.nsx_v.vcns.get_version()})
                raise nsx_exc.NsxPluginException(err_msg=error)

            # Support NSX policies in default security groups
            self._use_nsx_policies = True
            # enable the extension
            self.supported_extension_aliases.append(sg_policy.ALIAS)
            self.supported_extension_aliases.append(nsxpolicy.ALIAS)

        # Support transparent VLANS from 6.3.0 onwards. The feature is only
        # supported if the global configuration flag vlan_transparent is
        # True
        if cfg.CONF.vlan_transparent:
            if c_utils.is_nsxv_version_6_3(self.nsx_v.vcns.get_version()):
                self.supported_extension_aliases.append(vlan_apidef.ALIAS)
            else:
                LOG.warning("Transparent support only from "
                            "NSX 6.3 onwards")
        self.sg_container_id = self._create_security_group_container()
        self.default_section = self._create_cluster_default_fw_section()

        self._router_managers = managers.RouterTypeManager(self)

        # Make sure starting rpc listeners (for QoS and other agents)
        # will happen only once
        self.start_rpc_listeners_called = False
        self.fwaas_callbacks = None

        # Service insertion driver register
        self._si_handler = fc_utils.NsxvServiceInsertionHandler(self)
        registry.subscribe(self.add_vms_to_service_insertion,
                           fc_utils.SERVICE_INSERTION_RESOURCE,
                           events.AFTER_CREATE)

        # Subscribe to subnet pools changes
        registry.subscribe(
            self.on_subnetpool_address_scope_updated,
            resources.SUBNETPOOL_ADDRESS_SCOPE, events.AFTER_UPDATE)

        if c_utils.is_nsxv_version_6_2(self.nsx_v.vcns.get_version()):
            self.supported_extension_aliases.append(provider_sg.ALIAS)

        # Bind QoS notifications
        qos_driver.register(self)

        registry.subscribe(self.spawn_complete,
                           resources.PROCESS,
                           events.AFTER_SPAWN)

        # subscribe the init complete method last, so it will be called only
        # if init was successful
        registry.subscribe(self.init_complete,
                           resources.PROCESS,
                           events.AFTER_INIT)

    @staticmethod
    def plugin_type():
        return projectpluginmap.NsxPlugins.NSX_V

    @staticmethod
    def is_tvd_plugin():
        return False

    def spawn_complete(self, resource, event, trigger, payload=None):
        # Init the FWaaS support with RPC listeners for the original process
        self._init_fwaas(with_rpc=True)

        # The rest of this method should run only once, but after init_complete
        if not self.init_is_complete:
            self.init_complete(None, None, None)

        if not self._is_sub_plugin:
            self.octavia_stats_collector = (
                octavia_listener.NSXOctaviaStatisticsCollector(
                    self,
                    self._get_octavia_stats_getter(),
                    self._get_octavia_status_getter()))

    def init_complete(self, resource, event, trigger, payload=None):
        with locking.LockManager.get_lock('plugin-init-complete'):
            if self.init_is_complete:
                # Should be called only once per worker
                return
            has_metadata_cfg = (
                cfg.CONF.nsxv.nova_metadata_ips and
                cfg.CONF.nsxv.mgt_net_moid and
                cfg.CONF.nsxv.mgt_net_proxy_ips and
                cfg.CONF.nsxv.mgt_net_proxy_netmask)
            if has_metadata_cfg:
                # Init md_proxy handler per availability zone
                self.metadata_proxy_handler = {}
                for az in self.get_azs_list():
                    # create metadata handler only if the az supports it.
                    # if not, the global one will be used
                    if az.supports_metadata():
                        self.metadata_proxy_handler[az.name] = (
                            nsx_v_md_proxy.NsxVMetadataProxyHandler(
                                self, az))
                LOG.debug('Metadata is configured for AZs %s',
                          self.metadata_proxy_handler.keys())
            else:
                LOG.debug('No metadata configuration available!')

            self.housekeeper = housekeeper.NsxHousekeeper(
                hk_ns='vmware_nsx.neutron.nsxv.housekeeper.jobs',
                hk_jobs=cfg.CONF.nsxv.housekeeping_jobs,
                hk_readonly=cfg.CONF.nsxv.housekeeping_readonly,
                hk_readonly_jobs=cfg.CONF.nsxv.housekeeping_readonly_jobs)

            # Init octavia listener and endpoints
            if not self._is_sub_plugin:
                octavia_objects = self._get_octavia_objects()
                self.octavia_listener = octavia_listener.NSXOctaviaListener(
                    **octavia_objects)

            # Init the FWaaS support without RPC listeners
            # for the spawn workers
            self._init_fwaas(with_rpc=False)

            self.init_is_complete = True

    def _get_octavia_objects(self):
        return {
            'loadbalancer': loadbalancer_mgr.EdgeLoadBalancerManagerFromDict(
                        self.nsx_v),
            'listener': listener_mgr.EdgeListenerManagerFromDict(self.nsx_v),
            'pool': pool_mgr.EdgePoolManagerFromDict(self.nsx_v),
            'member': member_mgr.EdgeMemberManagerFromDict(self.nsx_v),
            'healthmonitor': healthmon_mgr.EdgeHealthMonitorManagerFromDict(
                    self.nsx_v),
            'l7policy': l7policy_mgr.EdgeL7PolicyManagerFromDict(self.nsx_v),
            'l7rule': l7rule_mgr.EdgeL7RuleManagerFromDict(self.nsx_v)}

    def _get_octavia_stats_getter(self):
        return listener_mgr.stats_getter

    def _get_octavia_status_getter(self):
        return loadbalancer_mgr.status_getter

    def _validate_nsx_version(self):
        ver = self.nsx_v.vcns.get_version()
        if version.LooseVersion(ver) < version.LooseVersion('6.2.3'):
            error = _("Plugin version doesn't support NSX version %s.") % ver
            raise nsx_exc.NsxPluginException(err_msg=error)

    def get_metadata_proxy_handler(self, az_name):
        if not self.metadata_proxy_handler:
            return None
        if az_name in self.metadata_proxy_handler:
            return self.metadata_proxy_handler[az_name]
        # fallback to the global handler
        # Note(asarfaty): in case this is called during init_complete the
        # default availability zone may still not exist.
        return self.metadata_proxy_handler.get(nsx_az.DEFAULT_NAME)

    def add_vms_to_service_insertion(self, sg_id):
        def _add_vms_to_service_insertion(*args, **kwargs):

            """Adding existing VMs to the service insertion security group

            Adding all current compute ports with port security to the service
            insertion security group in order to classify their traffic by the
            security redirect rules
            """
            sg_id = args[0]
            context = n_context.get_admin_context()
            filters = {'device_owner': ['compute:None']}
            ports = self.get_ports(context, filters=filters)
            for port in ports:
                # Only add compute ports with device-id, vnic & port security
                if (validators.is_attr_set(
                        port.get(ext_vnic_idx.VNIC_INDEX)) and
                    validators.is_attr_set(port.get('device_id')) and
                    port[psec.PORTSECURITY]):
                    try:
                        vnic_idx = port[ext_vnic_idx.VNIC_INDEX]
                        device_id = port['device_id']
                        vnic_id = self._get_port_vnic_id(vnic_idx, device_id)
                        self._add_member_to_security_group(sg_id, vnic_id)
                    except Exception as e:
                        LOG.info('Could not add port %(port)s to service '
                                 'insertion security group. Exception '
                                 '%(err)s',
                                 {'port': port['id'], 'err': e})

        # Doing this in a separate thread to not slow down the init process
        # in case there are many compute ports
        c_utils.spawn_n(_add_vms_to_service_insertion, sg_id)

    def start_rpc_listeners(self):
        if self.start_rpc_listeners_called:
            # If called more than once - we should not create it again
            return self.conn.consume_in_threads()

        LOG.info("NSXV plugin: starting RPC listeners")

        self.endpoints = [agents_db.AgentExtRpcCallback()]
        self.topic = topics.PLUGIN

        self.conn = n_rpc.Connection()
        self.conn.create_consumer(self.topic, self.endpoints, fanout=False)

        self.start_rpc_listeners_called = True
        return self.conn.consume_in_threads()

    def _init_fwaas(self, with_rpc):
        # Bind FWaaS callbacks to the driver
        if fwaas_utils.is_fwaas_v2_plugin_enabled():
            LOG.info("NSXv FWaaS v2 plugin enabled")
            self.fwaas_callbacks = fwaas_callbacks_v2.NsxvFwaasCallbacksV2(
                with_rpc)

    def _create_security_group_container(self):
        name = "OpenStack Security Group container"
        with locking.LockManager.get_lock('security-group-container-init'):
            container_id = self.nsx_v.vcns.get_security_group_id(name)
            if not container_id:
                description = ("OpenStack Security Group Container, "
                               "managed by Neutron nsx-v plugin.")
                container = {"securitygroup": {"name": name,
                                               "description": description}}
                h, container_id = (
                    self.nsx_v.vcns.create_security_group(container))
            return container_id

    def _find_router_driver(self, context, router_id):
        router_qry = context.session.query(l3_db_models.Router)
        router_db = router_qry.filter_by(id=router_id).one()
        return self._get_router_driver(context, router_db)

    def _get_router_driver(self, context, router_db):
        router_type_dict = {}
        self._extend_nsx_router_dict(router_type_dict, router_db)
        router_type = None
        if router_type_dict.get("distributed", False):
            router_type = "distributed"
        else:
            router_type = router_type_dict.get("router_type")
        return self._router_managers.get_tenant_router_driver(
            context, router_type)

    def _decide_router_type(self, context, r):
        router_type = None
        if (validators.is_attr_set(r.get("distributed")) and
            r.get("distributed")):
            router_type = "distributed"
            if validators.is_attr_set(r.get("router_type")):
                err_msg = _('Can not support router_type extension for '
                            'distributed router')
                raise n_exc.InvalidInput(error_message=err_msg)
        elif validators.is_attr_set(r.get("router_type")):
            router_type = r.get("router_type")

        router_type = self._router_managers.decide_tenant_router_type(
            context, router_type)
        if router_type == "distributed":
            r["distributed"] = True
            r["router_type"] = "exclusive"
        else:
            r["distributed"] = False
            r["router_type"] = router_type

    @staticmethod
    @resource_extend.extends([l3_apidef.ROUTERS])
    def _extend_nsx_router_dict(router_res, router_db):
        router_type_obj = rt_rtr.RouterType_mixin()
        router_type_obj._extend_nsx_router_dict(
            router_res, router_db, router_type_obj.nsx_attributes)

    def _get_cluster_default_fw_section_rules(self):
        """Build Default cluster rules"""
        rules = [{'name': 'Default DHCP rule for OS Security Groups',
                  'action': 'allow',
                  'services': [('17', '67', None, None),
                               ('17', '68', None, None)]},
                 {'name': 'Default ICMPv6 rule for OS Security Groups',
                  'action': 'allow',
                  'services': [('58', None,
                                constants.ICMPV6_TYPE_NS, None),
                               ('58', None,
                                constants.ICMPV6_TYPE_NA, None),
                               ('58', None,
                                constants.ICMPV6_TYPE_RA, None),
                               ('58', None,
                                constants.ICMPV6_TYPE_MLD_QUERY, None)]},
                 {'name': 'Default DHCPv6 rule for OS Security Groups',
                  'action': 'allow',
                  'services': [('17', '546', None, None),
                               ('17', '547', None, None)]}]

        if cfg.CONF.nsxv.cluster_moid:
            applied_to_ids = cfg.CONF.nsxv.cluster_moid
            applied_to_type = 'ClusterComputeResource'
        else:
            applied_to_ids = [self.sg_container_id]
            applied_to_type = 'SecurityGroup'

        rule_list = []
        for rule in rules:
            rule_config = self.nsx_sg_utils.get_rule_config(
                applied_to_ids, rule['name'], rule['action'],
                applied_to_type, services=rule['services'],
                logged=cfg.CONF.nsxv.log_security_groups_allowed_traffic)
            rule_list.append(rule_config)

        igmp_names = ['IGMP Membership Query', 'IGMP V2 Membership Report',
                      'IGMP V3 Membership Report', 'IGMP Leave Group']
        igmp_ids = []
        for name in igmp_names:
            igmp_id = self._get_appservice_id(name)
            if igmp_id:
                igmp_ids.append(igmp_id)
        if igmp_ids:
            rules = [{'name': 'Default IGMP rule for OS Security Groups',
                      'action': 'allow',
                      'service_ids': igmp_ids}]
            for rule in rules:
                rule_config = self.nsx_sg_utils.get_rule_config(
                    applied_to_ids, rule['name'], rule['action'],
                    applied_to_type,
                    application_services=rule['service_ids'],
                    logged=cfg.CONF.nsxv.log_security_groups_allowed_traffic)
                rule_list.append(rule_config)

        # Default security-group rules
        block_rule = self.nsx_sg_utils.get_rule_config(
            [self.sg_container_id], 'Block All', 'deny',
            logged=cfg.CONF.nsxv.log_security_groups_blocked_traffic)
        rule_list.append(block_rule)

        return rule_list

    def _create_cluster_default_fw_section(self, update_section=False):
        section_name = 'OS Cluster Security Group section'
        with locking.LockManager.get_lock('default-section-init'):
            section_id = self.nsx_v.vcns.get_section_id(section_name)
            if section_id and not update_section:
                # No need to update an existing section, unless the
                # configuration changed
                return section_id

            rule_list = self._get_cluster_default_fw_section_rules()
            section = self.nsx_sg_utils.get_section_with_rules(
                section_name, rule_list, section_id)
            section_req_body = self.nsx_sg_utils.to_xml_string(section)
            if section_id:
                self.nsx_v.vcns.update_section_by_id(
                    section_id, 'ip', section_req_body)
            else:
                # cluster section does not exists. Create it above the
                # default l3 section
                try:
                    l3_id = self.nsx_v.vcns.get_default_l3_id()
                    h, c = self.nsx_v.vcns.create_section(
                        'ip', section_req_body, insert_before=l3_id)
                    section_id = self.nsx_sg_utils.parse_and_get_section_id(c)
                except Exception as e:
                    # another controller might have already created one
                    section_id = self.nsx_v.vcns.get_section_id(section_name)
                    if not section_id:
                        with excutils.save_and_reraise_exception():
                            LOG.error("Failed to create default section: %s",
                                      e)
        return section_id

    def _create_dhcp_static_binding(self, context, neutron_port_db):

        network_id = neutron_port_db['network_id']
        device_owner = neutron_port_db['device_owner']
        if device_owner.startswith("compute"):
            s_bindings = self.edge_manager.create_static_binding(
                context, neutron_port_db)
            self.edge_manager.create_dhcp_bindings(
                    context, neutron_port_db['id'], network_id, s_bindings)

    def _delete_dhcp_static_binding(self, context, neutron_port_db,
                                    log_error=True):

        port_id = neutron_port_db['id']
        network_id = neutron_port_db['network_id']
        try:
            self.edge_manager.delete_dhcp_binding(
                context, port_id, network_id, neutron_port_db['mac_address'])
        except Exception as e:
            msg = ("Unable to delete static bindings for port %(id)s"
                   "Error: %(e)s" % {'id': port_id, 'e': e})
            if log_error:
                LOG.error(msg)
            else:
                LOG.info(msg)

    def _validate_network_qos(self, context, network, backend_network):
        err_msg = None
        if validators.is_attr_set(network.get(qos_consts.QOS_POLICY_ID)):
            if not backend_network:
                err_msg = (_("Cannot configure QOS on external networks"))
            if not cfg.CONF.nsxv.use_dvs_features:
                err_msg = (_("Cannot configure QOS "
                             "without enabling use_dvs_features"))
        if err_msg:
            raise n_exc.InvalidInput(error_message=err_msg)

        self._validate_qos_policy_id(
            context, network.get(qos_consts.QOS_POLICY_ID))

    def _get_network_az_from_net_data(self, net_data):
        if az_def.AZ_HINTS in net_data and net_data[az_def.AZ_HINTS]:
            return self._availability_zones_data.get_availability_zone(
                net_data[az_def.AZ_HINTS][0])
        return self.get_default_az()

    def _get_network_az_dvs_id(self, net_data):
        az = self._get_network_az_from_net_data(net_data)
        return az.dvs_id

    def _get_network_vdn_scope_id(self, net_data):
        az = self._get_network_az_from_net_data(net_data)
        return az.vdn_scope_id

    def _validate_dvs_id(self, dvs_id):
        if not self.nsx_v.vcns.validate_dvs(
            dvs_id, dvs_list=self.existing_dvs):
            # try to retrieve the dvs list again in case 1 was added
            self.existing_dvs = self.nsx_v.vcns.get_dvs_list()
            if not self.nsx_v.vcns.validate_dvs(
                dvs_id, dvs_list=self.existing_dvs):
                return False
        return True

    def _validate_provider_create(self, context, network):
        if not validators.is_attr_set(network.get(mpnet_apidef.SEGMENTS)):
            return

        az_dvs = self._get_network_az_dvs_id(network)
        for segment in network[mpnet_apidef.SEGMENTS]:
            network_type = segment.get(pnet.NETWORK_TYPE)
            physical_network = segment.get(pnet.PHYSICAL_NETWORK)
            segmentation_id = segment.get(pnet.SEGMENTATION_ID)
            network_type_set = validators.is_attr_set(network_type)
            segmentation_id_set = validators.is_attr_set(segmentation_id)
            physical_network_set = validators.is_attr_set(physical_network)

            err_msg = None
            if not network_type_set:
                err_msg = _("%s required") % pnet.NETWORK_TYPE
            elif network_type == c_utils.NsxVNetworkTypes.FLAT:
                if segmentation_id_set:
                    err_msg = _("Segmentation ID cannot be specified with "
                                "flat network type")
                if physical_network_set:
                    # Validate the DVS Id
                    if not self._validate_dvs_id(physical_network):
                        err_msg = (_("DVS Id %s could not be found") %
                                   physical_network)
            elif network_type == c_utils.NsxVNetworkTypes.VLAN:
                if not segmentation_id_set:
                    if physical_network_set:
                        if physical_network not in self._network_vlans:
                            err_msg = _("Invalid physical network for "
                                        "segmentation ID allocation")
                    else:
                        err_msg = _("Segmentation ID must be specified with "
                                    "vlan network type")
                elif (segmentation_id_set and
                      not utils.is_valid_vlan_tag(segmentation_id)):
                    err_msg = (_("%(segmentation_id)s out of range "
                                 "(%(min_id)s through %(max_id)s)") %
                               {'segmentation_id': segmentation_id,
                                'min_id': constants.MIN_VLAN_TAG,
                                'max_id': constants.MAX_VLAN_TAG})
                elif (segmentation_id_set and physical_network_set and
                      not self._validate_dvs_id(physical_network)):
                    err_msg = (_("DVS Id %s could not be found") %
                               physical_network)
                else:
                    # Verify segment is not already allocated
                    bindings = nsxv_db.get_network_bindings_by_vlanid(
                        context.session, segmentation_id)
                    if bindings:
                        dvs_ids = self._get_dvs_ids(physical_network,
                                                    az_dvs)
                        for phy_uuid in dvs_ids:
                            for binding in bindings:
                                if binding['phy_uuid'] == phy_uuid:
                                    raise n_exc.VlanIdInUse(
                                        vlan_id=segmentation_id,
                                        physical_network=phy_uuid)
            elif network_type == c_utils.NsxVNetworkTypes.VXLAN:
                # Currently unable to set the segmentation id
                if segmentation_id_set:
                    err_msg = _("Segmentation ID cannot be set with VXLAN")
            elif network_type == c_utils.NsxVNetworkTypes.PORTGROUP:
                external = network.get(extnet_apidef.EXTERNAL)
                if segmentation_id_set:
                    err_msg = _("Segmentation ID cannot be set with portgroup")
                if not physical_network_set:
                    err_msg = _("Physical network must be set")
                elif not self.nsx_v.vcns.validate_network(physical_network):
                    err_msg = _("Physical network doesn't exist")
                # A provider network portgroup will need the network name to
                # match the portgroup name
                elif ((not validators.is_attr_set(external) or
                       validators.is_attr_set(external) and not external) and
                      not self.nsx_v.vcns.validate_network_name(
                          physical_network, network['name'])):
                    err_msg = _("Portgroup name must match network name")

                if not err_msg:
                    # make sure no other neutron network is using it
                    bindings = (
                        nsxv_db.get_network_bindings_by_physical_net_and_type(
                            context.elevated().session, physical_network,
                            network_type))
                    if bindings:
                        err_msg = (_('protgroup %s is already used by '
                                     'another network') % physical_network)
            else:
                err_msg = (_("%(net_type_param)s %(net_type_value)s not "
                             "supported") %
                           {'net_type_param': pnet.NETWORK_TYPE,
                            'net_type_value': network_type})
            if err_msg:
                raise n_exc.InvalidInput(error_message=err_msg)
            # TODO(salvatore-orlando): Validate tranport zone uuid
            # which should be specified in physical_network

    def _validate_network_type(self, context, network_id, net_types):
        bindings = nsxv_db.get_network_bindings(context.session,
                                                network_id)
        multiprovider = nsx_db.is_multiprovider_network(context.session,
                                                        network_id)
        if bindings:
            if not multiprovider:
                return bindings[0].binding_type in net_types
            for binding in bindings:
                if binding.binding_type not in net_types:
                    return False
            return True
        return False

    def _extend_network_dict_provider(self, context, network,
                                      multiprovider=None, bindings=None):
        if 'id' not in network:
            return
        if not bindings:
            bindings = nsxv_db.get_network_bindings(context.session,
                                                    network['id'])
        if not multiprovider:
            multiprovider = nsx_db.is_multiprovider_network(context.session,
                                                            network['id'])
        # With NSX plugin 'normal' overlay networks will have no binding
        # TODO(salvatore-orlando) make sure users can specify a distinct
        # phy_uuid as 'provider network' for STT net type
        if bindings:
            if not multiprovider:
                # network came in through provider networks api
                network[pnet.NETWORK_TYPE] = bindings[0].binding_type
                network[pnet.PHYSICAL_NETWORK] = bindings[0].phy_uuid
                network[pnet.SEGMENTATION_ID] = bindings[0].vlan_id
            else:
                # network come in though multiprovider networks api
                network[mpnet_apidef.SEGMENTS] = [
                    {pnet.NETWORK_TYPE: binding.binding_type,
                     pnet.PHYSICAL_NETWORK: binding.phy_uuid,
                     pnet.SEGMENTATION_ID: binding.vlan_id}
                    for binding in bindings]

        # update availability zones
        network[az_def.COLLECTION_NAME] = (
            self._get_network_availability_zones(context, network))

    def _get_subnet_as_providers(self, context, subnet, nw_dict=None):
        net_id = subnet.get('network_id')
        if net_id is None:
            net_id = self.get_subnet(context, subnet['id']).get('network_id')

        if nw_dict:
            providers = nw_dict.get(net_id, [])
        else:
            as_provider_data = nsxv_db.get_edge_vnic_bindings_by_int_lswitch(
                context.session, net_id)
            providers = [asp['edge_id'] for asp in as_provider_data]
        return providers

    def get_subnet(self, context, id, fields=None):
        subnet = super(NsxVPluginV2, self).get_subnet(context, id, fields)

        if not context.is_admin:
            return subnet
        if fields and as_providers.ADV_SERVICE_PROVIDERS in fields:
            subnet[as_providers.ADV_SERVICE_PROVIDERS] = (
                self._get_subnet_as_providers(context, subnet))
        return subnet

    def get_subnets(self, context, filters=None, fields=None, sorts=None,
                    limit=None, marker=None, page_reverse=False):
        subnets = super(NsxVPluginV2, self).get_subnets(context, filters,
                                                        fields, sorts, limit,
                                                        marker, page_reverse)

        if not context.is_admin or (not filters and not fields):
            return subnets

        new_subnets = []
        if ((fields and as_providers.ADV_SERVICE_PROVIDERS in fields) or
            (filters and filters.get(as_providers.ADV_SERVICE_PROVIDERS))):

            # This ugly mess should reduce DB calls with network_id field
            # as filter - as network_id is not indexed
            vnic_binds = nsxv_db.get_edge_vnic_bindings_with_networks(
                context.session)
            nw_dict = {}
            for vnic_bind in vnic_binds:
                if nw_dict.get(vnic_bind['network_id']):
                    nw_dict[vnic_bind['network_id']].append(
                        vnic_bind['edge_id'])
                else:
                    nw_dict[vnic_bind['network_id']] = [vnic_bind['edge_id']]

            # We only deal metadata provider field when:
            # - adv_service_provider is explicitly retrieved
            # - adv_service_provider is used in a filter
            for subnet in subnets:
                as_provider = self._get_subnet_as_providers(
                    context, subnet, nw_dict)
                md_filter = (
                    None if filters is None
                    else filters.get(as_providers.ADV_SERVICE_PROVIDERS))

                if md_filter is None or len(set(as_provider) & set(md_filter)):
                    # Include metadata_providers only if requested in results
                    if fields and as_providers.ADV_SERVICE_PROVIDERS in fields:
                        subnet[as_providers.ADV_SERVICE_PROVIDERS] = (
                            as_provider)

                    new_subnets.append(subnet)
        else:
            # No need to handle metadata providers field
            return subnets

        return new_subnets

    def _convert_to_transport_zones_dict(self, network):
        """Converts the provider request body to multiprovider.
        Returns: True if request is multiprovider False if provider
        and None if neither.
        """
        if any(validators.is_attr_set(network.get(f))
               for f in (pnet.NETWORK_TYPE, pnet.PHYSICAL_NETWORK,
                         pnet.SEGMENTATION_ID)):
            if validators.is_attr_set(network.get(mpnet_apidef.SEGMENTS)):
                raise mpnet_exc.SegmentsSetInConjunctionWithProviders()
            # convert to transport zone list
            network[mpnet_apidef.SEGMENTS] = [
                {pnet.NETWORK_TYPE: network[pnet.NETWORK_TYPE],
                 pnet.PHYSICAL_NETWORK: network[pnet.PHYSICAL_NETWORK],
                 pnet.SEGMENTATION_ID: network[pnet.SEGMENTATION_ID]}]
            del network[pnet.NETWORK_TYPE]
            del network[pnet.PHYSICAL_NETWORK]
            del network[pnet.SEGMENTATION_ID]
            return False
        if validators.is_attr_set(network.get(mpnet_apidef.SEGMENTS)):
            return True

    def _delete_backend_network(self, moref, dvs_id=None):
        """Deletes the backend NSX network.

        This can either be a VXLAN or a VLAN network. The type is determined
        by the prefix of the moref.
        The dvs_id is relevant only if it is a vlan network
        """
        if moref.startswith(PORTGROUP_PREFIX):
            self.nsx_v.delete_port_group(dvs_id, moref)
        else:
            self.nsx_v.delete_virtual_wire(moref)

    def _get_vlan_network_name(self, net_data, dvs_id):
        if net_data.get('name') is None:
            net_data['name'] = ''
        # Maximum name length is 80 characters. 'id' length is 36
        # maximum prefix for name plus dvs-id is 43
        if net_data['name'] == '':
            prefix = dvs_id[:43]
        else:
            prefix = ('%s-%s' % (dvs_id, net_data['name']))[:43]
        return '%s-%s' % (prefix, net_data['id'])

    def _update_network_teaming(self, dvs_id, net_id, net_moref):
        if self._vcm:
            try:
                h, switch = self.nsx_v.vcns.get_vdn_switch(dvs_id)
            except Exception:
                LOG.warning('DVS %s not registered on NSX. Unable to '
                            'update teaming for network %s',
                            dvs_id, net_id)
                return
            try:
                self._vcm.update_port_groups_config(
                    dvs_id, net_id, net_moref,
                    self._vcm.update_port_group_spec_teaming,
                    switch)
            except Exception as e:
                LOG.error('Unable to update teaming information for '
                          'net %(net_id)s. Error: %(e)s',
                          {'net_id': net_id, 'e': e})

    def _create_vlan_network_at_backend(self, net_data, dvs_id):
        network_name = self._get_vlan_network_name(net_data, dvs_id)
        segment = net_data[mpnet_apidef.SEGMENTS][0]
        vlan_tag = 0
        if (segment.get(pnet.NETWORK_TYPE) ==
            c_utils.NsxVNetworkTypes.VLAN):
            vlan_tag = segment.get(pnet.SEGMENTATION_ID, 0)
        portgroup = {'vlanId': vlan_tag,
                     'networkBindingType': 'Static',
                     'networkName': network_name,
                     'networkType': 'Isolation'}
        config_spec = {'networkSpec': portgroup}
        try:
            h, c = self.nsx_v.vcns.create_port_group(dvs_id,
                                                     config_spec)
        except Exception as e:
            error = (_("Failed to create port group on DVS: %(dvs_id)s. "
                       "Reason: %(reason)s") % {'dvs_id': dvs_id,
                                                'reason': e.response})
            raise nsx_exc.NsxPluginException(err_msg=error)
        self._update_network_teaming(dvs_id, net_data['id'], c)
        return c

    def _get_dvs_ids(self, physical_network, default_dvs):
        """Extract DVS-IDs provided in the physical network field.

        If physical network attribute is not set, return the pre configured
        dvs-id from nsx.ini file, otherwise convert physical network string
        to a list of unique DVS-IDs.
        """
        if not validators.is_attr_set(physical_network):
            return [default_dvs]
        # Return unique DVS-IDs only and ignore duplicates
        return list(set(
            dvs.strip() for dvs in physical_network.split(',') if dvs))

    def _add_member_to_security_group(self, sg_id, vnic_id):
        with locking.LockManager.get_lock('neutron-security-ops' + str(sg_id)):
            try:
                self.nsx_v.vcns.add_member_to_security_group(
                    sg_id, vnic_id)
                LOG.info("Added %(sg_id)s member to NSX security "
                         "group %(vnic_id)s",
                         {'sg_id': sg_id, 'vnic_id': vnic_id})
            except Exception:
                with excutils.save_and_reraise_exception():
                    LOG.error("NSX security group %(sg_id)s member add "
                              "failed %(vnic_id)s.",
                              {'sg_id': sg_id,
                               'vnic_id': vnic_id})

    def _add_security_groups_port_mapping(self, session, vnic_id,
                                          added_sgids):
        if vnic_id is None or added_sgids is None:
            return
        for add_sg in added_sgids:
            nsx_sg_id = nsx_db.get_nsx_security_group_id(session, add_sg,
                                                         moref=True)
            if nsx_sg_id is None:
                LOG.warning("NSX security group not found for %s", add_sg)
            else:
                self._add_member_to_security_group(nsx_sg_id, vnic_id)

    def _remove_member_from_security_group(self, sg_id, vnic_id):
        with locking.LockManager.get_lock('neutron-security-ops' + str(sg_id)):
            try:
                h, c = self.nsx_v.vcns.remove_member_from_security_group(
                    sg_id, vnic_id)
            except Exception:
                LOG.debug("NSX security group %(nsx_sg_id)s member "
                          "delete failed %(vnic_id)s",
                          {'nsx_sg_id': sg_id,
                           'vnic_id': vnic_id})

    def _delete_security_groups_port_mapping(self, session, vnic_id,
                                             deleted_sgids):
        if vnic_id is None or deleted_sgids is None:
            return
        # Remove vnic from delete security groups binding
        for del_sg in deleted_sgids:
            nsx_sg_id = nsx_db.get_nsx_security_group_id(session, del_sg,
                                                         moref=True)
            if nsx_sg_id is None:
                LOG.warning("NSX security group not found for %s", del_sg)
            else:
                self._remove_member_from_security_group(nsx_sg_id, vnic_id)

    def _update_security_groups_port_mapping(self, session, port_id,
                                             vnic_id, current_sgids,
                                             new_sgids):

        new_sgids = new_sgids or []
        current_sgids = current_sgids or []
        # If no vnic binding is found, nothing can be done, so return
        if vnic_id is None:
            return
        deleted_sgids = set()
        added_sgids = set()
        # Find all delete security group from port binding
        for curr_sg in current_sgids:
            if curr_sg not in new_sgids:
                deleted_sgids.add(curr_sg)
        # Find all added security group from port binding
        for new_sg in new_sgids:
            if new_sg not in current_sgids:
                added_sgids.add(new_sg)

        self._delete_security_groups_port_mapping(session, vnic_id,
                                                  deleted_sgids)
        self._add_security_groups_port_mapping(session, vnic_id,
                                               added_sgids)

    def _get_port_vnic_id(self, port_index, device_id):
        # The vnic-id format which is expected by NSXv
        return '%s.%03d' % (device_id, port_index)

    def init_availability_zones(self):
        self._availability_zones_data = nsx_az.NsxVAvailabilityZones(
            use_tvd_config=self._is_sub_plugin)

    def _list_availability_zones(self, context, filters=None):
        result = {}
        for az in self.get_azs_names():
            # Add this availability zone as a router & network resource
            if filters:
                if 'name' in filters and az not in filters['name']:
                    continue
            for res in ['network', 'router']:
                if 'resource' not in filters or res in filters['resource']:
                    result[(az, res)] = True
        return result

    def _validate_availability_zones_in_obj(self, context, resource_type,
                                           obj_data):
        if az_def.AZ_HINTS in obj_data:
            self.validate_availability_zones(context, resource_type,
                                             obj_data[az_def.AZ_HINTS],
                                             force=True)

    def validate_availability_zones(self, context, resource_type,
                                    availability_zones, force=False):
        """Verify that the availability zones exist, and only 1 hint
        was set.
        """
        # This method is called directly from this plugin but also from
        # registered callbacks
        if self._is_sub_plugin and not force:
            # validation should be done together for both plugins
            return
        return self.validate_obj_azs(availability_zones)

    def _prepare_spoofguard_policy(self, network_type, net_data, net_morefs):
        # The method will determine if a portgroup is already assigned to a
        # spoofguard policy. If so, it will return the predefined policy. If
        # not a new spoofguard policy will be created
        if network_type == c_utils.NsxVNetworkTypes.PORTGROUP:
            pcs = self.nsx_v.vcns.get_spoofguard_policies()[1].get('policies',
                                                                   [])
            for policy in pcs:
                for ep in policy['enforcementPoints']:
                    if ep['id'] == net_morefs[0]:
                        return policy['policyId'], True
            LOG.warning("No spoofguard policy will be created for %s",
                        net_data['id'])
            return None, False
        # Always use enabled spoofguard policy. ports with disabled port
        # security will be added to the exclude list
        sg_policy_id = self.nsx_v.vcns.create_spoofguard_policy(
                net_morefs, net_data['id'], True)[1]
        return sg_policy_id, False

    def _get_physical_network(self, network_type, net_data):
        if network_type == c_utils.NsxVNetworkTypes.VXLAN:
            return self._get_network_vdn_scope_id(net_data)
        # Use the dvs_id of the availability zone
        return self._get_network_az_dvs_id(net_data)

    def _generate_segment_id(self, context, physical_network, net_data):
        bindings = nsxv_db.get_network_bindings_by_physical_net(
            context.session, physical_network)
        vlan_ranges = self._network_vlans.get(physical_network, [])
        if vlan_ranges:
            vlan_ids = set()
            for vlan_min, vlan_max in vlan_ranges:
                vlan_ids |= set(range(vlan_min, vlan_max + 1))
        else:
            vlan_min = constants.MIN_VLAN_TAG
            vlan_max = constants.MAX_VLAN_TAG
            vlan_ids = set(range(vlan_min, vlan_max + 1))
        used_ids_in_range = set([binding.vlan_id for binding in bindings
                                 if binding.vlan_id in vlan_ids])
        free_ids = list(vlan_ids ^ used_ids_in_range)
        if len(free_ids) == 0:
            raise n_exc.NoNetworkAvailable()
        net_data[mpnet_apidef.SEGMENTS][0][pnet.SEGMENTATION_ID] = free_ids[0]

    def create_network(self, context, network):
        net_data = network['network']
        tenant_id = net_data['tenant_id']
        self._ensure_default_security_group(context, tenant_id)
        # Process the provider network extension
        provider_type = self._convert_to_transport_zones_dict(net_data)
        self._validate_provider_create(context, net_data)
        self._validate_availability_zones_in_obj(context, 'network', net_data)
        net_data['id'] = str(uuidutils.generate_uuid())

        external = net_data.get(extnet_apidef.EXTERNAL)
        backend_network = (not validators.is_attr_set(external) or
                           validators.is_attr_set(external) and not external)
        network_type = None
        generate_segmenation_id = False
        lock_vlan_creation = False
        if provider_type is not None:
            segment = net_data[mpnet_apidef.SEGMENTS][0]
            network_type = segment.get(pnet.NETWORK_TYPE)
            if network_type == c_utils.NsxVNetworkTypes.VLAN:
                physical_network = segment.get(pnet.PHYSICAL_NETWORK)
                if physical_network in self._network_vlans:
                    lock_vlan_creation = True
                if not validators.is_attr_set(
                    segment.get(pnet.SEGMENTATION_ID)):
                    generate_segmenation_id = True
        if lock_vlan_creation:
            with locking.LockManager.get_lock(
                'vlan-networking-%s' % physical_network):
                if generate_segmenation_id:
                    self._generate_segment_id(context, physical_network,
                                              net_data)
                else:
                    segmentation_id = segment.get(pnet.SEGMENTATION_ID)
                    if nsxv_db.get_network_bindings_by_ids(context.session,
                        segmentation_id, physical_network):
                        raise n_exc.VlanIdInUse(
                                    vlan_id=segmentation_id,
                                    physical_network=physical_network)
                return self._create_network(context, network, net_data,
                                            provider_type, external,
                                            backend_network, network_type)
        else:
            return self._create_network(context, network, net_data,
                                        provider_type, external,
                                        backend_network, network_type)

    def _create_network(self, context, network, net_data,
                        provider_type, external, backend_network,
                        network_type):
        # A external network should be created in the case that we have a flat,
        # vlan or vxlan network. For port groups we do not make any changes.
        external_backend_network = (
            external and provider_type is not None and
            network_type != c_utils.NsxVNetworkTypes.PORTGROUP)
        self._validate_network_qos(context, net_data, backend_network)

        # Update the transparent vlan if configured
        vlt = False
        if extensions.is_extension_supported(self, 'vlan-transparent'):
            vlt = vlan_apidef.get_vlan_transparent(net_data)

        if backend_network or external_backend_network:
            #NOTE(abhiraut): Consider refactoring code below to have more
            #                readable conditions.
            if (provider_type is None or
                network_type == c_utils.NsxVNetworkTypes.VXLAN):
                virtual_wire = {"name": net_data['id'],
                                "tenantId": "virtual wire tenant"}
                if vlt:
                    virtual_wire["guestVlanAllowed"] = True
                config_spec = {"virtualWireCreateSpec": virtual_wire}
                vdn_scope_id = self._get_network_vdn_scope_id(net_data)
                if provider_type is not None:
                    segment = net_data[mpnet_apidef.SEGMENTS][0]
                    if validators.is_attr_set(
                        segment.get(pnet.PHYSICAL_NETWORK)):
                        vdn_scope_id = segment.get(pnet.PHYSICAL_NETWORK)
                        if not (self.nsx_v.vcns.
                                validate_vdn_scope(vdn_scope_id)):
                            raise nsx_exc.NsxResourceNotFound(
                                res_name='vdn_scope_id',
                                res_id=vdn_scope_id)
                h, c = self.nsx_v.vcns.create_virtual_wire(vdn_scope_id,
                                                           config_spec)
                net_morefs = [c]
                dvs_net_ids = [net_data['id']]
            elif network_type == c_utils.NsxVNetworkTypes.PORTGROUP:
                if vlt:
                    raise NotImplementedError(_("Transparent support only "
                                                "for VXLANs"))
                segment = net_data[mpnet_apidef.SEGMENTS][0]
                net_morefs = [segment.get(pnet.PHYSICAL_NETWORK)]
                dvs_net_ids = [net_data['name']]
            else:
                segment = net_data[mpnet_apidef.SEGMENTS][0]
                physical_network = segment.get(pnet.PHYSICAL_NETWORK)
                # Retrieve the list of dvs-ids from physical network.
                # If physical_network attr is not set, retrieve a list
                # consisting of a single dvs-id pre-configured in nsx.ini
                az_dvs = self._get_network_az_dvs_id(net_data)
                dvs_ids = self._get_dvs_ids(physical_network, az_dvs)
                dvs_net_ids = []
                # Save the list of netmorefs from the backend
                net_morefs = []
                dvs_pg_mappings = {}
                for dvs_id in dvs_ids:
                    try:
                        net_moref = self._create_vlan_network_at_backend(
                            dvs_id=dvs_id,
                            net_data=net_data)
                    except nsx_exc.NsxPluginException:
                        with excutils.save_and_reraise_exception():
                            # Delete VLAN networks on other DVSes if it
                            # fails to be created on one DVS and reraise
                            # the original exception.
                            for dvsmoref, netmoref in dvs_pg_mappings.items():
                                self._delete_backend_network(
                                    netmoref, dvsmoref)
                    dvs_pg_mappings[dvs_id] = net_moref
                    net_morefs.append(net_moref)
                    dvs_net_ids.append(self._get_vlan_network_name(
                        net_data, dvs_id))
                    if vlt:
                        try:
                            self._vcm.update_port_groups_config(
                                dvs_id, net_data['id'], net_moref,
                                self._vcm.update_port_group_spec_trunk,
                                {})
                        except Exception:
                            with excutils.save_and_reraise_exception():
                                # Delete VLAN networks on other DVSes if it
                                # fails to be created on one DVS and reraise
                                # the original exception.
                                for dvsm, netm in dvs_pg_mappings.items():
                                    self._delete_backend_network(netm, dvsm)
        # Define variable to satisfy pylint check (E0601)
        predefined = None
        try:
            net_data[psec.PORTSECURITY] = net_data.get(psec.PORTSECURITY, True)
            if not cfg.CONF.nsxv.spoofguard_enabled:
                LOG.info("Network %s will have port security disabled",
                         net_data['id'])
                net_data[psec.PORTSECURITY] = False
            # Create SpoofGuard policy for network anti-spoofing
            # allow_multiple_addresses will be overridden in case the user
            # requires allowing multiple or cidr-based allowed address pairs
            # defined per port but doesn't want to disable spoofguard globally
            sg_policy_id = None
            allow_multiple_addresses = (not net_data[psec.PORTSECURITY] and
                                        cfg.CONF.
                                        nsxv.allow_multiple_ip_addresses)
            if (cfg.CONF.nsxv.spoofguard_enabled and backend_network and not
                    allow_multiple_addresses):
                # This variable is set as the method below may result in a
                # exception and we may need to rollback
                predefined = False
                sg_policy_id, predefined = self._prepare_spoofguard_policy(
                    network_type, net_data, net_morefs)
            with db_api.CONTEXT_WRITER.using(context):
                new_net = super(NsxVPluginV2, self).create_network(context,
                                                                   network)
                self._extension_manager.process_create_network(
                    context, net_data, new_net)
                # Process port security extension
                self._process_network_port_security_create(
                    context, net_data, new_net)

                if vlt:
                    super(NsxVPluginV2, self).update_network(context,
                        new_net['id'],
                        {'network': {'vlan_transparent': vlt}})

                # update the network with the availability zone hints
                if az_def.AZ_HINTS in net_data:
                    az_hints = az_validator.convert_az_list_to_string(
                        net_data[az_def.AZ_HINTS])
                    super(NsxVPluginV2, self).update_network(context,
                        new_net['id'],
                        {'network': {az_def.AZ_HINTS: az_hints}})
                    new_net[az_def.AZ_HINTS] = az_hints
                    # still no availability zones until subnets creation
                    new_net[az_def.COLLECTION_NAME] = []

                # DB Operations for setting the network as external
                self._process_l3_create(context, new_net, net_data)
                if (net_data.get(mpnet_apidef.SEGMENTS) and
                    isinstance(provider_type, bool)):
                    net_bindings = []
                    for tz in net_data[mpnet_apidef.SEGMENTS]:
                        network_type = tz.get(pnet.NETWORK_TYPE)
                        segmentation_id = tz.get(pnet.SEGMENTATION_ID, 0)
                        segmentation_id_set = validators.is_attr_set(
                            segmentation_id)
                        if not segmentation_id_set:
                            segmentation_id = 0
                        physical_network = tz.get(pnet.PHYSICAL_NETWORK, '')
                        physical_net_set = validators.is_attr_set(
                            physical_network)
                        if not physical_net_set:
                            if external_backend_network:
                                physical_network = net_morefs[0]
                            else:
                                physical_network = self._get_physical_network(
                                    network_type, net_data)
                        net_bindings.append(nsxv_db.add_network_binding(
                            context.session, new_net['id'],
                            network_type,
                            physical_network,
                            segmentation_id))
                    if provider_type:
                        nsx_db.set_multiprovider_network(context.session,
                                                         new_net['id'])
                    self._extend_network_dict_provider(context, new_net,
                                                       provider_type,
                                                       net_bindings)
                if backend_network or external_backend_network:
                    # Save moref in the DB for future access
                    if (network_type == c_utils.NsxVNetworkTypes.VLAN or
                        network_type == c_utils.NsxVNetworkTypes.FLAT):
                        # Save netmoref to dvs id mappings for VLAN network
                        # type for future access.
                        for dvs_id, netmoref in dvs_pg_mappings.items():
                            nsx_db.add_neutron_nsx_network_mapping(
                                session=context.session,
                                neutron_id=new_net['id'],
                                nsx_switch_id=netmoref,
                                dvs_id=dvs_id)
                    else:
                        for net_moref in net_morefs:
                            nsx_db.add_neutron_nsx_network_mapping(
                                context.session, new_net['id'],
                                net_moref)
                    if (cfg.CONF.nsxv.spoofguard_enabled and
                        backend_network and sg_policy_id):
                        nsxv_db.map_spoofguard_policy_for_network(
                            context.session, new_net['id'], sg_policy_id)

        except Exception:
            with excutils.save_and_reraise_exception():
                # Delete the backend network
                if backend_network or external_backend_network:
                    if (cfg.CONF.nsxv.spoofguard_enabled and sg_policy_id and
                        not predefined):
                        self.nsx_v.vcns.delete_spoofguard_policy(sg_policy_id)
                    # Ensure that an predefined portgroup will not be deleted
                    if network_type == c_utils.NsxVNetworkTypes.VXLAN:
                        for net_moref in net_morefs:
                            self._delete_backend_network(net_moref)
                    elif (network_type and
                          network_type != c_utils.NsxVNetworkTypes.PORTGROUP):
                        for dvsmrf, netmrf in dvs_pg_mappings.items():
                            self._delete_backend_network(netmrf, dvsmrf)
                LOG.exception('Failed to create network')

        # If init is incomplete calling _update_qos_network() will result a
        # deadlock.
        # That situation happens when metadata init is creating a network
        # on its 1st execution.
        # Therefore we skip this code during init.
        if backend_network and self.init_is_complete:
            # Update the QOS restrictions of the backend network
            self._update_qos_on_created_network(context, net_data, new_net)

        # this extra lookup is necessary to get the
        # latest db model for the extension functions
        net_model = self._get_network(context, new_net['id'])
        resource_extend.apply_funcs('networks', new_net, net_model)
        return new_net

    def _update_qos_on_created_network(self, context, net_data, new_net):
        qos_policy_id = qos_com_utils.set_qos_policy_on_new_net(
            context, net_data, new_net, allow_external=True)

        if qos_policy_id:
            # update the QoS data on the backend
            self._update_qos_on_backend_network(
                context, net_data['id'], qos_policy_id)

    def _update_qos_on_backend_network(self, context, net_id, qos_policy_id):
        # Translate the QoS rule data into Nsx values
        qos_data = qos_utils.NsxVQosRule(
            context=context, qos_policy_id=qos_policy_id)

        # default dvs for this network
        az = self.get_network_az_by_net_id(context, net_id)
        az_dvs_id = az.dvs_id

        # get the network moref/s from the db
        net_mappings = nsx_db.get_nsx_network_mappings(
            context.session, net_id)
        for mapping in net_mappings:
            # update the qos restrictions of the network
            self._vcm.update_port_groups_config(
                mapping.dvs_id or az_dvs_id,
                net_id, mapping.nsx_id,
                self._vcm.update_port_group_spec_qos, qos_data)

    def _cleanup_dhcp_edge_before_deletion(self, context, net_id):
        if self.metadata_proxy_handler:
            # Find if this is the last network which is bound
            # to DHCP Edge. If it is - cleanup Edge metadata config
            dhcp_edge = nsxv_db.get_dhcp_edge_network_binding(
                context.session, net_id)

            if dhcp_edge:
                edge_vnics = nsxv_db.get_edge_vnic_bindings_by_edge(
                    context.session, dhcp_edge['edge_id'])

                # If the DHCP Edge is connected to two networks:
                # the deleted network and the inter-edge network, we can delete
                # the inter-edge interface
                if len(edge_vnics) == 2:
                    rtr_binding = nsxv_db.get_nsxv_router_binding_by_edge(
                        context.session, dhcp_edge['edge_id'])
                    if rtr_binding:
                        rtr_id = rtr_binding['router_id']
                        az_name = rtr_binding['availability_zone']
                        md_proxy = self.get_metadata_proxy_handler(az_name)
                        if md_proxy:
                            md_proxy.cleanup_router_edge(context, rtr_id)
                else:
                    self.edge_manager.reconfigure_shared_edge_metadata_port(
                        context, (vcns_const.DHCP_EDGE_PREFIX + net_id)[:36])

    def _is_neutron_spoofguard_policy(self, net_id, moref, policy_id):
        # A neutron policy will have the network UUID as the name of the
        # policy
        try:
            policy = self.nsx_v.vcns.get_spoofguard_policy(policy_id)[1]
        except Exception:
            LOG.error("Policy does not exists for %s", policy_id)
            # We will not attempt to delete a policy that does not exist
            return False
        if policy:
            for ep in policy['enforcementPoints']:
                if ep['id'] == moref and policy['name'] == net_id:
                    return True
        return False

    def _validate_internal_network(self, context, network_id):
        if nsxv_db.get_nsxv_internal_network_by_id(
            context.elevated().session, network_id):
            msg = (_("Cannot delete internal network %s or its subnets and "
                     "ports") % network_id)
            raise n_exc.InvalidInput(error_message=msg)

    def delete_network(self, context, id):
        mappings = nsx_db.get_nsx_network_mappings(context.session, id)
        bindings = nsxv_db.get_network_bindings(context.session, id)
        if cfg.CONF.nsxv.spoofguard_enabled:
            sg_policy_id = nsxv_db.get_spoofguard_policy_id(
                context.session, id)

        self._validate_internal_network(context, id)

        # Update the DHCP edge for metadata and clean the vnic in DHCP edge
        # if there is only no other existing port besides DHCP port
        filters = {'network_id': [id]}
        ports = self.get_ports(context, filters=filters)
        auto_del = [p['id'] for p in ports
                    if p['device_owner'] in [constants.DEVICE_OWNER_DHCP]]
        is_dhcp_backend_deleted = False
        if auto_del:
            filters = {'network_id': [id], 'enable_dhcp': [True]}
            sids = self.get_subnets(context, filters=filters, fields=['id'])
            if len(sids) > 0:
                try:
                    self._cleanup_dhcp_edge_before_deletion(context, id)
                    self.edge_manager.delete_dhcp_edge_service(context, id)
                    is_dhcp_backend_deleted = True
                except Exception:
                    with excutils.save_and_reraise_exception():
                        LOG.exception('Failed to delete network')
            for port_id in auto_del:
                try:
                    self.delete_port(context.elevated(), port_id,
                                     force_delete_dhcp=True)
                except Exception as e:
                    LOG.warning('Unable to delete port %(port_id)s. '
                                'Reason: %(e)s',
                                {'port_id': port_id, 'e': e})

        with db_api.CONTEXT_WRITER.using(context):
            self._process_l3_delete(context, id)
            # We would first delete subnet db if the backend dhcp service is
            # deleted in case of entering delete_subnet logic and retrying
            # to delete backend dhcp service again.
            if is_dhcp_backend_deleted:
                subnets = self._get_subnets_by_network(context, id)
                for subnet in subnets:
                    self.base_delete_subnet(context, subnet['id'])

            super(NsxVPluginV2, self).delete_network(context, id)

        # Do not delete a predefined port group that was attached to
        # an external network
        if (bindings and
            bindings[0].binding_type == c_utils.NsxVNetworkTypes.PORTGROUP):
            if cfg.CONF.nsxv.spoofguard_enabled and sg_policy_id:
                if self._is_neutron_spoofguard_policy(id, mappings[0].nsx_id,
                                                      sg_policy_id):
                    self.nsx_v.vcns.delete_spoofguard_policy(sg_policy_id)
            return

        # Delete the backend network if necessary. This is done after
        # the base operation as that may throw an exception in the case
        # that there are ports defined on the network.
        if mappings:
            if cfg.CONF.nsxv.spoofguard_enabled and sg_policy_id:
                self.nsx_v.vcns.delete_spoofguard_policy(sg_policy_id)
            edge_utils.check_network_in_use_at_backend(context, id)
            for mapping in mappings:
                self._delete_backend_network(
                    mapping.nsx_id, mapping.dvs_id)

    def _extend_get_network_dict_provider(self, context, net):
        self._extend_network_dict_provider(context, net)
        net[qos_consts.QOS_POLICY_ID] = qos_com_utils.get_network_policy_id(
            context, net['id'])

    def get_network(self, context, id, fields=None):
        with db_api.CONTEXT_READER.using(context):
            # goto to the plugin DB and fetch the network
            network = self._get_network(context, id)
            # Don't do field selection here otherwise we won't be able
            # to add provider networks fields
            net_result = self._make_network_dict(network,
                                                 context=context)
            self._extend_get_network_dict_provider(context, net_result)
        return db_utils.resource_fields(net_result, fields)

    def get_networks(self, context, filters=None, fields=None,
                     sorts=None, limit=None, marker=None,
                     page_reverse=False):
        filters = filters or {}
        with db_api.CONTEXT_READER.using(context):
            networks = (
                super(NsxVPluginV2, self).get_networks(
                    context, filters, fields, sorts,
                    limit, marker, page_reverse))
            for net in networks:
                self._extend_get_network_dict_provider(context, net)
        return (networks if not fields else
                [db_utils.resource_fields(network,
                                          fields) for network in networks])

    def _raise_if_updates_provider_attributes(self, original_network, attrs,
                                              az_dvs):
        """Raise exception if provider attributes are present.

        For the NSX-V we want to allow changing the physical network of
        vlan type networks.
        """
        if (original_network.get(pnet.NETWORK_TYPE) ==
            c_utils.NsxVNetworkTypes.VLAN and
            validators.is_attr_set(
                attrs.get(pnet.PHYSICAL_NETWORK)) and
            not validators.is_attr_set(
                attrs.get(pnet.NETWORK_TYPE)) and
            not validators.is_attr_set(
                attrs.get(pnet.SEGMENTATION_ID))):
            return
        c_utils.raise_if_updates_provider_attributes(attrs)

    def _update_vlan_network_dvs_ids(self, context, network,
                                     new_physical_network, az_dvs):
        """Update the dvs ids of a vlan provider network

        The new values will replace the old ones.

        Actions done in this function:
        - Create a backend network for each new dvs
        - Delete the backend networks for the old ones.
        - Return the relevant information in order to later also update
          the spoofguard policy, qos, network object and DB

        Returns:
        - dvs_list_changed True/False
        - dvs_pg_mappings - updated mapping of the elements dvs->moref
        """
        dvs_pg_mappings = {}

        current_dvs_ids = set(self._get_dvs_ids(
            network[pnet.PHYSICAL_NETWORK], az_dvs))
        new_dvs_ids = set(self._get_dvs_ids(
            new_physical_network, az_dvs))
        additional_dvs_ids = new_dvs_ids - current_dvs_ids
        removed_dvs_ids = current_dvs_ids - new_dvs_ids

        if not additional_dvs_ids and not removed_dvs_ids:
            # no changes in the list of DVS
            return False, dvs_pg_mappings

        self._convert_to_transport_zones_dict(network)
        # get the current mapping as in the DB
        db_mapping = nsx_db.get_nsx_network_mappings(
            context.session, network['id'])
        for db_map in db_mapping:
            dvs_pg_mappings[db_map.dvs_id] = db_map.nsx_id

        # delete old backend networks
        for dvs_id in removed_dvs_ids:
            nsx_id = dvs_pg_mappings.get(dvs_id)
            if nsx_id:
                #Note(asarfaty) This may fail if there is a vm deployed, but
                # since the delete is done offline we will not catch it here
                self._delete_backend_network(nsx_id, dvs_id)
                del dvs_pg_mappings[dvs_id]

        # create all the new backend networks
        for dvs_id in additional_dvs_ids:
            try:
                net_moref = self._create_vlan_network_at_backend(
                    dvs_id=dvs_id,
                    net_data=network)
            except nsx_exc.NsxPluginException:
                with excutils.save_and_reraise_exception():
                    # Delete VLAN networks on other DVSes if it
                    # fails to be created on one DVS and reraise
                    # the original exception.
                    for dvsmoref, netmoref in dvs_pg_mappings.items():
                        self._delete_backend_network(netmoref, dvsmoref)
            dvs_pg_mappings[dvs_id] = net_moref

        return True, dvs_pg_mappings

    def _update_network_validate_port_sec(self, context, net_id, net_attrs):
        if psec.PORTSECURITY in net_attrs and not net_attrs[psec.PORTSECURITY]:
            # check if there are compute ports on this network
            port_filters = {'network_id': [net_id],
                            'device_owner': ['compute:None']}
            compute_ports = self.get_ports(context, filters=port_filters)
            if compute_ports:
                LOG.warning("Disabling port-security on network %s would "
                            "require instance in the network to have VM tools "
                            "installed in order for security-groups to "
                            "function properly.", net_id)

    def allow_multiple_addresses_configure_spoofguard(self, context, id,
                                                      net_attrs, net_morefs):
        # User requires multiple addresses to be assigned to compute port
        # and therefore, the spoofguard policy is being removed for this net.
        orig_net = self.get_network(context, id)
        if not net_attrs[psec.PORTSECURITY]:
            sg_pol = nsxv_db.get_spoofguard_policy_id(context.session,
                                                      orig_net['id'])
            if sg_pol:
                try:
                    self.nsx_v.vcns.delete_spoofguard_policy(sg_pol)
                    nsxv_db.del_nsxv_spoofguard_binding(context.session,
                                                        sg_pol)
                except Exception as e:
                    LOG.error('Unable to delete spoofguard policy '
                              '%(sg_policy)s. Error: %(e)s',
                              {'sg_policy': sg_pol, 'e': e})
            else:
                LOG.warning("Could not locate spoofguard policy for "
                            "network %s", id)
        # User requires port-security-enabled set to True and thus requires
        # spoofguard installed for this network
        else:
            # Verifying that all ports are legal, i.e. not CIDR/subnet, and
            # that the same IP address is not used multiple times for a given
            # neutron network
            filters = {'network_id': [id]}
            ports = self.get_ports(context, filters=filters)
            valid_ports = []
            ip_addresses = set()
            if ports:
                for port in ports:
                    for ap in port[addr_apidef.ADDRESS_PAIRS]:
                        if len(ap['ip_address'].split('/')) > 1:
                            msg = _('Port %s contains CIDR/subnet, '
                                    'which is not supported at the '
                                    'backend ') % port['id']
                            raise n_exc.BadRequest(
                                    resource='networks',
                                    msg=msg)
                        set_len = len(ip_addresses)
                        ip_addresses.add(ap['ip_address'])
                        if len(ip_addresses) == set_len:
                            msg = _('IP address %(ip)s is allowed '
                                    'by more than 1 logical port. '
                                    'This is not supported by the '
                                    'backend. Port security cannot '
                                    'be enabled for network %(net)s') % {
                                'ip': ap['ip_address'], 'net': id}
                            LOG.error(msg)
                            raise n_exc.BadRequest(
                                resource='networks', msg=msg)
                        valid_ports.append(port)
            try:
                sg_policy_id, predefined = (
                        self._prepare_spoofguard_policy(
                            orig_net.get(pnet.NETWORK_TYPE), orig_net,
                            net_morefs))
                if sg_policy_id:
                    nsxv_db.map_spoofguard_policy_for_network(
                                context.session,
                                orig_net['id'], sg_policy_id)
            except Exception as e:
                msg = _('Unable to create spoofguard policy, error: %('
                        'error)s, '
                        'net_morefs=%(net_morefs)s, network_id= %('
                        'network_id)s') % {'error': e, 'net_morefs':
                    net_morefs, 'network_id': orig_net}
                raise n_exc.BadRequest(resource='spoofguard policy', msg=msg)

            try:
                for port in valid_ports:
                    vnic_idx = port.get(ext_vnic_idx.VNIC_INDEX)
                    device_id = port['device_id']
                    vnic_id = self._get_port_vnic_id(vnic_idx,
                                                     device_id)
                    self._update_vnic_assigned_addresses(context.session, port,
                                                         vnic_id)
            except Exception as e:
                msg = _('Unable to add port to spoofguard policy error '
                        '%s') % e
                raise n_exc.BadRequest(resource='spoofguard policy',
                                       msg=msg)

    def update_network(self, context, id, network):
        net_attrs = network['network']
        orig_net = self.get_network(context, id)
        az_dvs = self._get_network_az_dvs_id(orig_net)
        self._raise_if_updates_provider_attributes(
            orig_net, net_attrs, az_dvs)
        if net_attrs.get("admin_state_up") is False:
            raise NotImplementedError(_("admin_state_up=False networks "
                                        "are not supported."))

        ext_net = self._get_network(context, id)
        if not ext_net.external:
            net_morefs = nsx_db.get_nsx_switch_ids(context.session, id)
        else:
            net_morefs = []
        backend_network = bool(len(net_morefs) > 0)
        self._validate_network_qos(context, net_attrs, backend_network)

        # PortSecurity validation checks
        psec_update = (psec.PORTSECURITY in net_attrs and
                       orig_net[psec.PORTSECURITY] !=
                       net_attrs[psec.PORTSECURITY])
        if psec_update:
            self._update_network_validate_port_sec(context, id, net_attrs)

        # Change spoofguard accordingly - either remove if
        # port-security-enabled was set to false or add (with relevant ports)
        #  if set to true.
        if (cfg.CONF.nsxv.spoofguard_enabled and
                cfg.CONF.nsxv.allow_multiple_ip_addresses and psec_update):
            self.allow_multiple_addresses_configure_spoofguard(context, id,
                                                               net_attrs,
                                                               net_morefs)

        # Check if the physical network of a vlan provider network was updated
        updated_morefs = False
        if (net_attrs.get(pnet.PHYSICAL_NETWORK) and
            orig_net.get(pnet.NETWORK_TYPE) ==
            c_utils.NsxVNetworkTypes.VLAN):
            (updated_morefs,
             new_dvs_pg_mappings) = self._update_vlan_network_dvs_ids(
                context,
                orig_net,
                net_attrs[pnet.PHYSICAL_NETWORK],
                az_dvs)
            if updated_morefs:
                net_morefs = list(new_dvs_pg_mappings.values())

        with db_api.CONTEXT_WRITER.using(context):
            net_res = super(NsxVPluginV2, self).update_network(context, id,
                                                               network)
            self._extension_manager.process_update_network(context, net_attrs,
                                                           net_res)
            self._process_network_port_security_update(
                context, net_attrs, net_res)
            self._process_l3_update(context, net_res, net_attrs)
            self._extend_network_dict_provider(context, net_res)
            if updated_morefs:
                # delete old mapping before recreating all
                nsx_db.delete_neutron_nsx_network_mapping(
                    session=context.session, neutron_id=id)

                # Save netmoref to dvs id mappings for VLAN network
                # type for future access.
                dvs_ids = []
                for dvs_id, netmoref in new_dvs_pg_mappings.items():
                    nsx_db.add_neutron_nsx_network_mapping(
                        session=context.session,
                        neutron_id=id,
                        nsx_switch_id=netmoref,
                        dvs_id=dvs_id)
                    dvs_ids.append(dvs_id)
                all_dvs = ', '.join(sorted(dvs_ids))
                net_res[pnet.PHYSICAL_NETWORK] = all_dvs
                vlan_id = net_res.get(pnet.SEGMENTATION_ID)
                nsxv_db.update_network_binding_phy_uuid(
                    context.session, id,
                    net_res.get(pnet.NETWORK_TYPE),
                    vlan_id, all_dvs)

        # Updating SpoofGuard policy if exists, on failure revert to network
        # old state
        if (not ext_net.external and
            cfg.CONF.nsxv.spoofguard_enabled and updated_morefs):
            policy_id = nsxv_db.get_spoofguard_policy_id(context.session, id)
            try:
                # Always use enabled spoofguard policy. ports with disabled
                # port security will be added to the exclude list
                self.nsx_v.vcns.update_spoofguard_policy(
                    policy_id, net_morefs, id, True)
            except Exception:
                with excutils.save_and_reraise_exception():
                    revert_update = db_utils.resource_fields(
                        orig_net, ['shared', psec.PORTSECURITY])
                    self._process_network_port_security_update(
                        context, revert_update, net_res)
                    super(NsxVPluginV2, self).update_network(
                        context, id, {'network': revert_update})

        # Handle QOS updates (Value can be None, meaning to delete the
        # current policy), or moref updates with an existing qos policy
        if (not ext_net.external and
            (qos_consts.QOS_POLICY_ID in net_attrs) or
            (updated_morefs and orig_net.get(qos_consts.QOS_POLICY_ID))):
            # update the qos data
            qos_policy_id = (net_attrs[qos_consts.QOS_POLICY_ID]
                if qos_consts.QOS_POLICY_ID in net_attrs
                else orig_net.get(qos_consts.QOS_POLICY_ID))
            self._update_qos_on_backend_network(context, id, qos_policy_id)

            # attach the policy to the network in neutron DB
            qos_com_utils.update_network_policy_binding(
                context, id, qos_policy_id)

            net_res[qos_consts.QOS_POLICY_ID] = (
                qos_com_utils.get_network_policy_id(context, id))

        # Handle case of network name update - this only is relevant for
        # networks that we create - not portgroup providers
        if (net_attrs.get('name') and
            orig_net.get('name') != net_attrs.get('name') and
            (orig_net.get(pnet.NETWORK_TYPE) ==
             c_utils.NsxVNetworkTypes.VLAN or
             orig_net.get(pnet.NETWORK_TYPE) ==
             c_utils.NsxVNetworkTypes.FLAT)):
            # Only update networks created by plugin
            mappings = nsx_db.get_nsx_network_mappings(context.session, id)
            for mapping in mappings:
                network_name = self._get_vlan_network_name(net_res,
                                                           mapping.dvs_id)
                try:
                    self._vcm.update_port_groups_config(
                        mapping.dvs_id, id, mapping.nsx_id,
                        self._dvs.update_port_group_spec_name,
                        network_name)
                except Exception as e:
                    LOG.error('Unable to update name for net %(net_id)s. '
                              'Error: %(e)s',
                              {'net_id': id, 'e': e})

        return net_res

    def _validate_unique_address_pair_across_network(self, context,
                                                     port, address_pairs):
        network_id = port['network_id']
        filters = {'network_id': [network_id]}
        valid_existing_ports = []
        existing_fixed_and_addr_pairs = []

        for exist_port in self.get_ports(context, filters=filters):
            if exist_port['id'] != port['id']:
                valid_existing_ports.append(exist_port)
        for valid_port in valid_existing_ports:
            for fixed in valid_port.get('fixed_ips', []):
                existing_fixed_and_addr_pairs.append(fixed['ip_address'])
            for addr_pair in valid_port.get('allowed_address_pairs', []):
                existing_fixed_and_addr_pairs.append(addr_pair['ip_address'])
        fixed_ips_list = port.get('fixed_ips', [])
        # validate ip collision with fixed ips
        for fixed_ip in fixed_ips_list:
            ip = fixed_ip.get('ip_address')
            if ip in existing_fixed_and_addr_pairs:
                msg = _('IP address %s entered as fixed ip already '
                        'exists in the network. Duplicate IP addresses is not '
                        'supported at backend') % ip
                raise n_exc.InvalidInput(error_message=msg)
        # validate ip collision with address pair
        for pair in address_pairs:
            ip = pair.get('ip_address')
            if ip in existing_fixed_and_addr_pairs:
                msg = _('IP address %s entered as address pair already '
                        'exists in the network. Duplicate IP addresses is not '
                        'supported at backend') % ip
                raise n_exc.InvalidInput(error_message=msg)

    def _verify_cidr_defined(self, attrs):
        for ap in attrs[addr_apidef.ADDRESS_PAIRS]:
            # Check that the IP address is a subnet
            if len(ap['ip_address'].split('/')) > 1:
                msg = _('NSXv does not support CIDR as address pairs')
                raise n_exc.BadRequest(resource='address_pairs',
                                       msg=msg)

    def _validate_address_pairs(self, context, attrs, db_port):
        # Ground rule - if spoofguard exists: all tests must take place.
        policy_id = nsxv_db.get_spoofguard_policy_id(context.session,
                                                     db_port['network_id'])
        if policy_id:
            self._validate_unique_address_pair_across_network(
                     context, db_port, attrs[addr_apidef.ADDRESS_PAIRS])
            self._verify_cidr_defined(attrs)
        # Check that the MAC address is the same as the port
        for ap in attrs[addr_apidef.ADDRESS_PAIRS]:
            if ('mac_address' in ap and
                    ap['mac_address'] != db_port['mac_address']):
                msg = _('Address pairs should have same MAC as the '
                        'port')
                raise n_exc.BadRequest(resource='address_pairs', msg=msg)

    def _is_mac_in_use(self, context, network_id, mac_address):
        # Override this method as the backed doesn't support using the same
        # mac twice on any network, not just this specific network
        admin_ctx = context.elevated()
        return bool(admin_ctx.session.query(models_v2.Port).
                    filter(models_v2.Port.mac_address == mac_address).
                    count())

    @db_api.retry_db_errors
    def base_create_port(self, context, port):
        created_port = super(NsxVPluginV2, self).create_port(context, port)
        self._extension_manager.process_create_port(
            context, port['port'], created_port)
        return created_port

    def _validate_extra_dhcp_options(self, opts):
        if not opts:
            return
        for opt in opts:
            opt_name = opt['opt_name']
            opt_val = opt['opt_value']
            if opt_name == 'classless-static-route':
                # separate validation for option121
                if opt_val is not None:
                    try:
                        net, ip = opt_val.split(',')
                    except Exception:
                        msg = (_("Bad value %(val)s for DHCP option "
                                 "%(name)s") % {'name': opt_name,
                                                'val': opt_val})
                        raise n_exc.InvalidInput(error_message=msg)
            elif opt_name not in vcns_const.SUPPORTED_DHCP_OPTIONS:
                try:
                    option = int(opt_name)
                except ValueError:
                    option = 255
                if option >= 255:
                    msg = (_("DHCP option %s is not supported") % opt_name)
                    LOG.error(msg)
                    raise n_exc.InvalidInput(error_message=msg)

    def _validate_port_qos(self, port):
        if validators.is_attr_set(port.get(qos_consts.QOS_POLICY_ID)):
            err_msg = (_("Cannot configure QOS directly on ports"))
            raise n_exc.InvalidInput(error_message=err_msg)

    def _assert_on_lb_port_admin_state(self, port_data, original_port,
                                       device_owner):
        if device_owner in [constants.DEVICE_OWNER_LOADBALANCERV2,
                            oct_const.DEVICE_OWNER_OCTAVIA]:
            orig_state = original_port.get("admin_state_up")
            new_state = port_data.get("admin_state_up")
            if new_state is not None and (orig_state != new_state):
                err_msg = _("Changing admin_state for "
                            "loadbalancer's internal port is not supported")
                LOG.warning(err_msg)
                raise n_exc.InvalidInput(error_message=err_msg)

    def create_port(self, context, port):
        port_data = port['port']
        dhcp_opts = port_data.get(ext_edo.EXTRADHCPOPTS)
        self._validate_extra_dhcp_options(dhcp_opts)
        self._validate_max_ips_per_port(port_data.get('fixed_ips', []),
                                        port_data.get('device_owner'))
        self._validate_port_qos(port_data)
        direct_vnic_type = self._validate_port_vnic_type(
            context, port_data, port_data['network_id'])

        # Do this outside of the context writer scope so it can overcome
        # failures
        if port_data.get('tenant_id'):
            self._ensure_default_security_group(context,
                                                port_data['tenant_id'])

        with db_api.CONTEXT_WRITER.using(context):
            # First we allocate port in neutron database
            neutron_db = super(NsxVPluginV2, self).create_port(context, port)
            self._extension_manager.process_create_port(
                context, port_data, neutron_db)

            # Port port-security is decided based on port's vnic_type and ports
            # network port-security state (unless explicitly requested
            # differently by the user).
            if not cfg.CONF.nsxv.spoofguard_enabled:
                port_security = False
            else:
                port_security = port_data.get(psec.PORTSECURITY)
            if validators.is_attr_set(port_security):
                # 'direct' and 'direct-physical' vnic types ports requires
                # port-security to be disabled.
                if direct_vnic_type and port_security:
                    err_msg = _("Security features are not supported for "
                                "ports with direct/direct-physical VNIC type")
                    raise n_exc.InvalidInput(error_message=err_msg)
            elif direct_vnic_type:
                # Implicitly disable port-security for direct vnic types.
                port_security = False
            else:
                port_security = self._get_network_security_binding(
                    context, neutron_db['network_id'])
            port_data[psec.PORTSECURITY] = port_security

            provider_sg_specified = (validators.is_attr_set(
                port_data.get(provider_sg.PROVIDER_SECURITYGROUPS)) and
                port_data[provider_sg.PROVIDER_SECURITYGROUPS] != [])
            has_security_groups = (
                self._check_update_has_security_groups(port))

            self._process_port_port_security_create(
                context, port_data, neutron_db)

            self._process_portbindings_create_and_update(
                context, port_data, neutron_db)

            # Update fields obtained from neutron db (eg: MAC address)
            port["port"].update(neutron_db)
            has_ip = self._ip_on_port(neutron_db)

            # allowed address pair checks
            attrs = port[port_def.RESOURCE_NAME]
            if self._check_update_has_allowed_address_pairs(port):
                if not port_security:
                    raise addr_exc.AddressPairAndPortSecurityRequired()
                self._validate_address_pairs(context, attrs, neutron_db)
            else:
                # remove ATTR_NOT_SPECIFIED
                attrs[addr_apidef.ADDRESS_PAIRS] = []

            # security group extension checks
            if has_ip and port_security:
                self._ensure_default_security_group_on_port(context, port)
                (sgids, ssgids) = self._get_port_security_groups_lists(
                    context, port)
            elif (has_security_groups or provider_sg_specified):
                LOG.error("Port has conflicting port security status and "
                          "security groups")
                raise psec_exc.PortSecurityAndIPRequiredForSecurityGroups()
            else:
                sgids = ssgids = []

            self._process_port_create_security_group(context, port_data, sgids)
            self._process_port_create_provider_security_group(context,
                                                              port_data,
                                                              ssgids)

            neutron_db[addr_apidef.ADDRESS_PAIRS] = (
                self._process_create_allowed_address_pairs(
                    context, neutron_db,
                    attrs.get(addr_apidef.ADDRESS_PAIRS)))

            self._process_port_create_extra_dhcp_opts(
                context, port_data, dhcp_opts)
            # MAC learning - only update DB. Can only update NSX when the port
            # exists - this is done via update
            if validators.is_attr_set(port_data.get(mac_ext.MAC_LEARNING)):
                if (((has_ip and port_security) or
                     has_security_groups or provider_sg_specified) and
                    port_data.get(mac_ext.MAC_LEARNING) is True):
                    err_msg = _("Security features are not supported for "
                                "mac learning")
                    raise n_exc.InvalidInput(error_message=err_msg)
                self._create_mac_learning_state(context, port_data)
            elif mac_ext.MAC_LEARNING in port_data:
                # This is due to the fact that the default is
                # ATTR_NOT_SPECIFIED
                port_data.pop(mac_ext.MAC_LEARNING)

        try:
            # Configure NSX - this should not be done in the DB transaction
            # Configure the DHCP Edge service
            self._create_dhcp_static_binding(context, port_data)
        except Exception:
            with excutils.save_and_reraise_exception():
                LOG.exception('Failed to create port')
                # Revert what we have created and raise the exception
                self.delete_port(context, port_data['id'])

        # this extra lookup is necessary to get the
        # latest db model for the extension functions
        port_model = self._get_port(context, port_data['id'])
        resource_extend.apply_funcs('ports', port_data, port_model)
        self._remove_provider_security_groups_from_list(port_data)
        self._extend_nsx_port_dict_binding(context, port_data)

        payload = events.DBEventPayload(
            context,
            states=(neutron_db,))
        registry.publish(resources.PORT, events.AFTER_CREATE, self,
                         payload=payload)
        return port_data

    def _make_port_dict(self, port, fields=None,
                        process_extensions=True, bulk=False):
        port_data = super(NsxVPluginV2, self)._make_port_dict(
            port, fields=fields,
            process_extensions=process_extensions, bulk=bulk)
        self._remove_provider_security_groups_from_list(port_data)
        return port_data

    def _get_port_subnet_mask(self, context, port):
        if len(port['fixed_ips']) > 0 and 'subnet_id' in port['fixed_ips'][0]:
            subnet_id = port['fixed_ips'][0]['subnet_id']
            subnet = self._get_subnet_object(context, subnet_id)
            return str(netaddr.IPNetwork(subnet.cidr).netmask)

    def _get_port_fixed_ip_addr(self, port):
        if (len(port['fixed_ips']) > 0 and
            'ip_address' in port['fixed_ips'][0]):
            return port['fixed_ips'][0]['ip_address']

    def _count_no_sec_ports_for_device_id(self, context, device_id):
        """Find how many compute ports with this device ID and no security
        there are, so we can decide on adding / removing the device from
        the exclusion list
        """
        filters = {'device_id': [device_id]}
        device_ports = self.get_ports(context.elevated(), filters=filters)
        ports = [port for port in device_ports
                 if port['device_owner'].startswith('compute')]
        return len([p for p in ports
            if validators.is_attr_set(p.get(ext_vnic_idx.VNIC_INDEX)) and
               not p[psec.PORTSECURITY]])

    def _add_vm_to_exclude_list(self, context, device_id, port_id):
        if (self._vcm and
            cfg.CONF.nsxv.use_exclude_list):
            # first time for this vm (we expect the count to be 1 already
            # because the DB was already updated)
            if (self._count_no_sec_ports_for_device_id(
                    context, device_id) <= 1):
                vm_moref = self._vcm.get_vm_moref(device_id)
                if vm_moref is not None:
                    try:
                        LOG.info("Add VM %(dev)s to exclude list on "
                                 "behalf of port %(port)s: added to "
                                 "list",
                                 {"dev": device_id, "port": port_id})
                        self.nsx_v.vcns.add_vm_to_exclude_list(vm_moref)
                    except vsh_exc.RequestBad as e:
                        LOG.error("Failed to add vm %(device)s "
                                  "moref %(moref)s to exclude list: "
                                  "%(err)s",
                                  {'device': device_id, 'moref': vm_moref,
                                   'err': e})
            else:
                LOG.info("Add VM %(dev)s to exclude list on behalf of "
                         "port %(port)s: VM already in list",
                         {"dev": device_id, "port": port_id})
                loose_ver = version.LooseVersion(self.nsx_v.vcns.get_version())
                if loose_ver < version.LooseVersion('6.3.3'):
                    LOG.info("Syncing firewall")
                    self.nsx_v.vcns.sync_firewall()

    def _remove_vm_from_exclude_list(self, context, device_id, port_id,
                                     expected_count=0):
        if (self._vcm and
            cfg.CONF.nsxv.use_exclude_list):
            # No ports left in DB (expected count is 0 or 1 depending
            # on whether the DB was already updated),
            # So we can remove it from the backend exclude list
            if (self._count_no_sec_ports_for_device_id(
                    context, device_id) <= expected_count):
                vm_moref = self._vcm.get_vm_moref(device_id)
                if vm_moref is not None:
                    try:
                        LOG.info("Remove VM %(dev)s from exclude list on "
                                 "behalf of port %(port)s: removed from "
                                 "list",
                                 {"dev": device_id, "port": port_id})
                        self.nsx_v.vcns.delete_vm_from_exclude_list(vm_moref)
                    except vsh_exc.RequestBad as e:
                        LOG.error("Failed to delete vm %(device)s "
                                  "moref %(moref)s from exclude list: "
                                  "%(err)s",
                                  {'device': device_id, 'moref': vm_moref,
                                   'err': e})
            else:
                LOG.info("Remove VM %(dev)s from exclude list on behalf "
                         "of port %(port)s: other ports still in list",
                         {"dev": device_id, "port": port_id})

    def update_port(self, context, id, port):
        with locking.LockManager.get_lock('port-update-%s' % id):

            original_port = super(NsxVPluginV2, self).get_port(context, id)
            self._extend_get_port_dict_qos_and_binding(context, original_port)
            is_compute_port = self._is_compute_port(original_port)
            device_id = original_port['device_id']
            if is_compute_port and device_id:
                # Lock on the device ID to make sure we do not change/delete
                # ports of the same device at the same time
                with locking.LockManager.get_lock(
                    'port-device-%s' % device_id):
                    return self._update_port(context, id, port, original_port,
                                             is_compute_port, device_id)
            else:
                return self._update_port(context, id, port, original_port,
                                         is_compute_port, device_id)

    def _update_dhcp_address(self, context, network_id):
        with locking.LockManager.get_lock('dhcp-update-%s' % network_id):
            address_groups = self._create_network_dhcp_address_group(
                context, network_id)
            self.edge_manager.update_dhcp_edge_service(
                context, network_id, address_groups=address_groups)

    def _nsx_update_mac_learning(self, context, port):
        net_id = port['network_id']
        # default dvs for this network
        az = self.get_network_az_by_net_id(context, net_id)
        az_dvs_id = az.dvs_id

        # get the network moref/s from the db
        net_mappings = nsx_db.get_nsx_network_mappings(
            context.session, net_id)
        for mapping in net_mappings:
            dvs_id = mapping.dvs_id or az_dvs_id
            try:
                self._vcm.update_port_groups_config(
                    dvs_id, net_id, mapping.nsx_id,
                    self._vcm.update_port_group_security_policy, True)
            except Exception as e:
                LOG.error("Unable to update network security override "
                          "policy: %s", e)
                return
            self._vcm.update_port_security_policy(
                dvs_id, net_id, mapping.nsx_id,
                port['device_id'], port['mac_address'],
                port[mac_ext.MAC_LEARNING])

    def _update_port(self, context, id, port, original_port, is_compute_port,
                     device_id):
        attrs = port[port_def.RESOURCE_NAME]
        port_data = port['port']
        dhcp_opts = port_data.get(ext_edo.EXTRADHCPOPTS)
        self._validate_extra_dhcp_options(dhcp_opts)
        self._validate_port_qos(port_data)
        if addr_apidef.ADDRESS_PAIRS in attrs:
            self._validate_address_pairs(context, attrs, original_port)
        self._validate_max_ips_per_port(
            port_data.get('fixed_ips', []),
            port_data.get('device_owner', original_port['device_owner']))
        orig_has_port_security = (cfg.CONF.nsxv.spoofguard_enabled and
                                  original_port[psec.PORTSECURITY])
        orig_device_owner = original_port.get('device_owner')
        self._assert_on_lb_port_admin_state(port_data, original_port,
                                            orig_device_owner)
        port_mac_change = port_data.get('mac_address') is not None
        port_ip_change = port_data.get('fixed_ips') is not None
        device_owner_change = port_data.get('device_owner') is not None
        # We do not support updating the port ip and device owner together
        if port_ip_change and device_owner_change:
            msg = (_('Cannot set fixed ips and device owner together for port '
                     '%s') % original_port['id'])
            raise n_exc.BadRequest(resource='port', msg=msg)

        # Check if port security has changed
        port_sec_change = False
        has_port_security = orig_has_port_security
        if (psec.PORTSECURITY in port_data and
            port_data[psec.PORTSECURITY] != original_port[psec.PORTSECURITY]):
            port_sec_change = True
            has_port_security = (cfg.CONF.nsxv.spoofguard_enabled and
                                 port_data[psec.PORTSECURITY])

        # Address pairs require port security
        if (not has_port_security and
            (original_port[addr_apidef.ADDRESS_PAIRS] or
             addr_apidef.ADDRESS_PAIRS in attrs)):
            msg = _('Address pairs require port security enabled')
            raise n_exc.BadRequest(resource='port', msg=msg)

        # TODO(roeyc): create a method '_process_vnic_index_update' from the
        # following code block
        # Process update for vnic-index
        vnic_idx = port_data.get(ext_vnic_idx.VNIC_INDEX)
        # Only set the vnic index for a compute VM
        if validators.is_attr_set(vnic_idx) and is_compute_port:
            # Update database only if vnic index was changed
            if original_port.get(ext_vnic_idx.VNIC_INDEX) != vnic_idx:
                self._set_port_vnic_index_mapping(
                    context, id, device_id, vnic_idx)
            vnic_id = self._get_port_vnic_id(vnic_idx, device_id)
            self._add_security_groups_port_mapping(
                context.session, vnic_id,
                original_port[ext_sg.SECURITYGROUPS] +
                original_port[provider_sg.PROVIDER_SECURITYGROUPS])
            if has_port_security:
                LOG.debug("Assigning vnic port fixed-ips: port %s, "
                          "vnic %s, with fixed-ips %s", id, vnic_id,
                          original_port['fixed_ips'])
                self._update_vnic_assigned_addresses(
                    context.session, original_port, vnic_id)
                if (cfg.CONF.nsxv.use_default_block_all and
                    not original_port[ext_sg.SECURITYGROUPS]):
                    self._add_member_to_security_group(
                        self.sg_container_id, vnic_id)
            else:
                # Add vm to the exclusion list, since it has no port security
                self._add_vm_to_exclude_list(context, device_id, id)
            # if service insertion is enabled - add this vnic to the service
            # insertion security group
            if self._si_handler.enabled and original_port[psec.PORTSECURITY]:
                self._add_member_to_security_group(self._si_handler.sg_id,
                                                   vnic_id)

        provider_sgs_specified = validators.is_attr_set(
            port_data.get(provider_sg.PROVIDER_SECURITYGROUPS))
        delete_provider_sg = provider_sgs_specified and (
            port_data[provider_sg.PROVIDER_SECURITYGROUPS] != [])
        delete_security_groups = self._check_update_deletes_security_groups(
            port)
        has_security_groups = self._check_update_has_security_groups(port)
        comp_owner_update = ('device_owner' in port_data and
                             port_data['device_owner'].startswith('compute:'))

        direct_vnic_type = self._validate_port_vnic_type(
            context, port_data, original_port['network_id'])
        if direct_vnic_type and has_port_security:
            err_msg = _("Security features are not supported for "
                        "ports with direct/direct-physical VNIC type")
            raise n_exc.InvalidInput(error_message=err_msg)
        old_mac_learning_state = original_port.get(mac_ext.MAC_LEARNING)
        if has_port_security:
            if ((mac_ext.MAC_LEARNING in port_data and
                 port_data[mac_ext.MAC_LEARNING] is True) or
                (mac_ext.MAC_LEARNING not in port_data and
                 old_mac_learning_state is True)):
                err_msg = _("Security features are not supported for "
                            "mac_learning")
                raise n_exc.InvalidInput(error_message=err_msg)

        with db_api.CONTEXT_WRITER.using(context):
            ret_port = super(NsxVPluginV2, self).update_port(
                context, id, port)
            self._extension_manager.process_update_port(
                context, port_data, ret_port)

            self._process_portbindings_create_and_update(
                context, port_data, ret_port)

            # copy values over - except fixed_ips as
            # they've already been processed
            updates_fixed_ips = port['port'].pop('fixed_ips', [])
            ret_port.update(port['port'])
            has_ip = self._ip_on_port(ret_port)

            # checks that if update adds/modify security groups,
            # then port has ip and port-security
            if not (has_ip and has_port_security):
                if has_security_groups or provider_sgs_specified:
                    LOG.error("Port has conflicting port security status and "
                              "security groups")
                    raise psec_exc.PortSecurityAndIPRequiredForSecurityGroups()
                if ((not delete_security_groups and
                     original_port[ext_sg.SECURITYGROUPS]) or
                        (not delete_provider_sg and
                         original_port[provider_sg.PROVIDER_SECURITYGROUPS])):
                    LOG.error("Port has conflicting port security status and "
                              "security groups")
                    raise psec_exc.PortSecurityAndIPRequiredForSecurityGroups()

            if delete_security_groups or has_security_groups:
                self.update_security_group_on_port(context, id, port,
                                                   original_port, ret_port)
            # NOTE(roeyc): Should call this method only after
            # update_security_group_on_port was called.
            pvd_sg_changed = self._process_port_update_provider_security_group(
                context, port, original_port, ret_port)

            update_assigned_addresses = False
            if addr_apidef.ADDRESS_PAIRS in attrs:
                update_assigned_addresses = self.update_address_pairs_on_port(
                    context, id, port, original_port, ret_port)

            self._update_extra_dhcp_opts_on_port(context, id, port,
                                                 ret_port)
            new_mac_learning_state = ret_port.get(mac_ext.MAC_LEARNING)
            if (new_mac_learning_state is not None and
                old_mac_learning_state != new_mac_learning_state):
                self._update_mac_learning_state(context, id,
                                                new_mac_learning_state)

            # update port security in DB if changed
            if psec.PORTSECURITY in port['port']:
                self._process_port_port_security_update(
                    context, port_data, ret_port)

        if comp_owner_update:
            # Create dhcp bindings, the port is now owned by an instance
            self._create_dhcp_static_binding(context, ret_port)
        elif port_mac_change or port_ip_change or dhcp_opts:
            owner = original_port['device_owner']
            # If port IP has changed we should update according to device
            # owner
            if is_compute_port:
                # This is an instance port, so re-create DHCP entry
                self._delete_dhcp_static_binding(context, original_port)
                self._create_dhcp_static_binding(context, ret_port)
            elif owner == constants.DEVICE_OWNER_DHCP:
                # Update the ip of the dhcp port
                # Note: if there are no fixed ips this means that we are in
                # the process of deleting the subnet of this port.
                # In this case we should avoid updating the nsx backed as the
                # delete subnet will soon do it.
                if dhcp_opts or ret_port.get('fixed_ips'):
                    self._update_dhcp_address(context,
                                              ret_port['network_id'])
            elif (owner == constants.DEVICE_OWNER_ROUTER_GW or
                  owner == constants.DEVICE_OWNER_ROUTER_INTF):
                # This is a router port - update the edge appliance
                old_ip = self._get_port_fixed_ip_addr(original_port)
                new_ip = self._get_port_fixed_ip_addr(ret_port)
                if ((old_ip is not None or new_ip is not None) and
                    (old_ip != new_ip)):
                    if validators.is_attr_set(original_port.get('device_id')):
                        router_id = original_port['device_id']
                        router_driver = self._find_router_driver(context,
                                                                 router_id)
                        # subnet mask is needed for adding new ip to the vnic
                        sub_mask = self._get_port_subnet_mask(context,
                                                              ret_port)
                        router_driver.update_router_interface_ip(
                            context,
                            router_id,
                            original_port['id'],
                            ret_port['network_id'],
                            old_ip, new_ip, sub_mask)
            else:
                LOG.info('Not updating fixed IP on backend for '
                         'device owner [%(dev_own)s] and port %(pid)s',
                         {'dev_own': owner, 'pid': original_port['id']})

        # Processing compute port update
        vnic_idx = original_port.get(ext_vnic_idx.VNIC_INDEX)
        if validators.is_attr_set(vnic_idx) and is_compute_port:
            vnic_id = self._get_port_vnic_id(vnic_idx, device_id)
            curr_sgids = (
                original_port[provider_sg.PROVIDER_SECURITYGROUPS] +
                original_port[ext_sg.SECURITYGROUPS])
            if ret_port['device_id'] != device_id:
                # Update change device_id - remove port-vnic association and
                # delete security-groups memberships for the vnic
                self._delete_security_groups_port_mapping(
                    context.session, vnic_id, curr_sgids)
                if cfg.CONF.nsxv.spoofguard_enabled:
                    if original_port[psec.PORTSECURITY]:
                        try:
                            self._remove_vnic_from_spoofguard_policy(
                                context.session,
                                original_port['network_id'],
                                vnic_id)
                        except Exception as e:
                            LOG.error('Could not delete the spoofguard '
                                      'policy. Exception %s', e)
                    # remove vm from the exclusion list when it is detached
                    # from the device if it has no port security
                    if not original_port[psec.PORTSECURITY]:
                        self._remove_vm_from_exclude_list(
                            context, device_id, id)
                self._delete_port_vnic_index_mapping(context, id)
                self._delete_dhcp_static_binding(context, original_port)

                # if service insertion is enabled - remove this vnic from the
                # service insertion security group
                if (self._si_handler.enabled and
                    original_port[psec.PORTSECURITY]):
                    self._remove_member_from_security_group(
                        self._si_handler.sg_id,
                        vnic_id)
            else:
                # port security enabled / disabled
                if port_sec_change:
                    if has_port_security:
                        LOG.debug("Assigning vnic port fixed-ips: port %s, "
                                  "vnic %s, with fixed-ips %s", id, vnic_id,
                                  original_port['fixed_ips'])
                        self._update_vnic_assigned_addresses(
                            context.session, original_port, vnic_id)
                        # Remove vm from the exclusion list, since it now has
                        # port security
                        self._remove_vm_from_exclude_list(context, device_id,
                                                          id)
                        # add the vm to the service insertion
                        if self._si_handler.enabled:
                            self._add_member_to_security_group(
                                self._si_handler.sg_id, vnic_id)
                    elif cfg.CONF.nsxv.spoofguard_enabled:
                        try:
                            self._remove_vnic_from_spoofguard_policy(
                                context.session, original_port['network_id'],
                                vnic_id)
                        except Exception as e:
                            LOG.error('Could not delete the spoofguard '
                                      'policy. Exception %s', e)
                        # Add vm to the exclusion list, since it has no port
                        # security now
                        self._add_vm_to_exclude_list(context, device_id, id)
                        # remove the vm from the service insertion
                        if self._si_handler.enabled:
                            self._remove_member_from_security_group(
                                self._si_handler.sg_id, vnic_id)

                # Update vnic with the newest approved IP addresses
                if (has_port_security and
                    (updates_fixed_ips or update_assigned_addresses)):
                    LOG.debug("Updating vnic port fixed-ips: port %s, vnic "
                              "%s, fixed-ips %s",
                              id, vnic_id, ret_port['fixed_ips'])
                    self._update_vnic_assigned_addresses(
                        context.session, ret_port, vnic_id)
                if not has_port_security and has_security_groups:
                    LOG.warning("port-security is disabled on "
                                "port %(id)s, "
                                "VM tools must be installed on instance "
                                "%(device_id)s for security-groups to "
                                "function properly ",
                                {'id': id,
                                 'device_id': original_port['device_id']})
                if (delete_security_groups or has_security_groups or
                    pvd_sg_changed):
                    # Update security-groups,
                    # calculate differences and update vnic membership
                    # accordingly.
                    new_sgids = (
                        ret_port[provider_sg.PROVIDER_SECURITYGROUPS] +
                        ret_port[ext_sg.SECURITYGROUPS])
                    self._update_security_groups_port_mapping(
                        context.session, id, vnic_id, curr_sgids, new_sgids)
                    if (cfg.CONF.nsxv.use_default_block_all and
                        not ret_port[ext_sg.SECURITYGROUPS]):
                        # If there are no security groups ensure that the
                        # default is 'Drop All'
                        self._add_member_to_security_group(
                            self.sg_container_id, vnic_id)

        # update mac learning on NSX
        if self._vcm:
            mac_learning = self.get_mac_learning_state(context, id)
            if mac_learning is not None:
                try:
                    self._nsx_update_mac_learning(context, ret_port)
                except Exception as e:
                    LOG.error("Unable to update mac learning for port %s, "
                              "reason: %s", id, e)

        registry.publish(
            resources.PORT, events.AFTER_UPDATE, self,
            payload=events.DBEventPayload(
                context,
                resource_id=id,
                metadata={'mac_address_updated': False},
                states=(original_port, ret_port,)))

        return ret_port

    def _extend_get_port_dict_qos_and_binding(self, context, port):
        self._extend_nsx_port_dict_binding(context, port)
        # add the qos policy id from the DB (always None in this plugin)
        if 'id' in port:
            port[qos_consts.QOS_POLICY_ID] = qos_com_utils.get_port_policy_id(
                context, port['id'])

    def _extend_nsx_port_dict_binding(self, context, port_data):
        # Extend port dict binding in case the data was not updated from the
        # DB by _extend_port_portbinding, which means this is an older port
        if pbin.VIF_TYPE not in port_data:
            port_data[pbin.VIF_TYPE] = nsx_constants.VIF_TYPE_DVS
        if pbin.VNIC_TYPE not in port_data:
            port_data[pbin.VNIC_TYPE] = pbin.VNIC_NORMAL
        if pbin.VIF_DETAILS not in port_data:
            port_data[pbin.VIF_DETAILS] = {pbin.CAP_PORT_FILTER: True}
            if 'network_id' in port_data:
                net_bindings = nsxv_db.get_network_bindings(
                    context.session, port_data['network_id'])
                if net_bindings:
                    port_data[pbin.VIF_DETAILS][pbin.VIF_DETAILS_VLAN] = (
                        net_bindings[0].vlan_id)

    def get_port(self, context, id, fields=None):
        port = super(NsxVPluginV2, self).get_port(context, id, fields=None)
        self._extend_get_port_dict_qos_and_binding(context, port)
        return db_utils.resource_fields(port, fields)

    def get_ports(self, context, filters=None, fields=None,
                  sorts=None, limit=None, marker=None,
                  page_reverse=False):
        filters = filters or {}
        self._update_filters_with_sec_group(context, filters)
        with db_api.CONTEXT_READER.using(context):
            ports = (
                super(NsxVPluginV2, self).get_ports(
                    context, filters, fields, sorts,
                    limit, marker, page_reverse))
            self._log_get_ports(ports, filters)
            # Add the relevant port extensions
            for port in ports[:]:
                self._extend_get_port_dict_qos_and_binding(context, port)
        return (ports if not fields else
                [db_utils.resource_fields(port, fields) for port in ports])

    def delete_port(self, context, id, l3_port_check=True,
                    nw_gw_port_check=True, force_delete_dhcp=False,
                    allow_delete_internal=False,
                    allow_delete_lb_if=False):
        # Send delete port notification to any interested service plugin
        registry.publish(resources.PORT, events.BEFORE_DELETE, self,
                         payload=events.DBEventPayload(
                             context, resource_id=id,
                             metadata={'port_check': l3_port_check}))

        neutron_db_port = self.get_port(context, id)
        device_id = neutron_db_port['device_id']
        is_compute_port = self._is_compute_port(neutron_db_port)
        if not allow_delete_internal:
            self._validate_internal_network(
                context, neutron_db_port['network_id'])
        if (not allow_delete_lb_if and
            neutron_db_port.get('device_owner') and
            neutron_db_port['device_owner'] == lb_common.LBAAS_DEVICE_OWNER):
            msg = _("Cannot delete LB interface port")
            raise n_exc.InvalidInput(error_message=msg)

        if is_compute_port and device_id:
            # Lock on the device ID to make sure we do not change/delete
            # ports of the same device at the same time
            with locking.LockManager.get_lock(
                'port-device-%s' % device_id):
                return self._delete_port(context, id, l3_port_check,
                                         nw_gw_port_check, neutron_db_port,
                                         force_delete_dhcp)
        else:
            return self._delete_port(context, id, l3_port_check,
                                     nw_gw_port_check, neutron_db_port,
                                     force_delete_dhcp)

    def _delete_port(self, context, id, l3_port_check,
                     nw_gw_port_check, neutron_db_port,
                     force_delete_dhcp=False):
        """Deletes a port on a specified Virtual Network.

        If the port contains a remote interface attachment, the remote
        interface is first un-plugged and then the port is deleted.

        :returns: None
        :raises: exception.PortInUse
        :raises: exception.PortNotFound
        :raises: exception.NetworkNotFound
        """
        # if needed, check to see if this is a port owned by
        # a l3 router.  If so, we should prevent deletion here
        if l3_port_check:
            self.prevent_l3_port_deletion(context, id)
        if (not force_delete_dhcp and
            neutron_db_port['device_owner'] in [constants.DEVICE_OWNER_DHCP]):
            msg = (_('Can not delete DHCP port %s') % neutron_db_port['id'])
            raise n_exc.BadRequest(resource='port', msg=msg)

        # If this port is attached to a device, remove the corresponding vnic
        # from all NSXv Security-Groups and the spoofguard policy
        port_index = neutron_db_port.get(ext_vnic_idx.VNIC_INDEX)
        compute_port = self._is_compute_port(neutron_db_port)
        if validators.is_attr_set(port_index):
            vnic_id = self._get_port_vnic_id(port_index,
                                             neutron_db_port['device_id'])
            sgids = neutron_db_port.get(ext_sg.SECURITYGROUPS)
            self._delete_security_groups_port_mapping(
                context.session, vnic_id, sgids)

            # if service insertion is enabled - remove this vnic from the
            # service insertion security group
            if self._si_handler.enabled and neutron_db_port[psec.PORTSECURITY]:
                self._remove_member_from_security_group(self._si_handler.sg_id,
                                                        vnic_id)

            if (cfg.CONF.nsxv.spoofguard_enabled and
                neutron_db_port[psec.PORTSECURITY]):
                try:
                    self._remove_vnic_from_spoofguard_policy(
                        context.session, neutron_db_port['network_id'],
                        vnic_id)
                except Exception as e:
                    LOG.error('Could not delete the spoofguard policy. '
                              'Exception %s', e)

            if not neutron_db_port[psec.PORTSECURITY] and compute_port:
                device_id = neutron_db_port['device_id']
                # Note that we expect to find 1 relevant port in the DB still
                # because this port was not yet deleted
                self._remove_vm_from_exclude_list(context, device_id, id,
                                                  expected_count=1)

        self.disassociate_floatingips(context, id)
        with db_api.CONTEXT_WRITER.using(context):
            super(NsxVPluginV2, self).delete_port(context, id)

        # deleting the dhcp binding anyway
        # (even if not compute port to be on the safe side)
        self._delete_dhcp_static_binding(
            context, neutron_db_port,
            log_error=bool(compute_port))

    def base_delete_subnet(self, context, subnet_id):
        with locking.LockManager.get_lock('neutron-base-subnet'):
            super(NsxVPluginV2, self).delete_subnet(context, subnet_id)

    def delete_subnet(self, context, id):
        subnet = self._get_subnet_object(context, id)
        filters = {'fixed_ips': {'subnet_id': [id]}}
        ports = self.get_ports(context, filters=filters)

        # Add nsx-dhcp-edge-pool here is because we first delete the subnet in
        # db.locking if the subnet overlaps with another new creating subnet,
        # there is a chance that the new creating subnet select the deleting
        # subnet's edge and send update dhcp interface rest call before
        # deleting subnet's corresponding dhcp interface rest call and lead to
        # overlap response from backend.
        network_id = subnet.network_id
        self._validate_internal_network(context, network_id)

        with locking.LockManager.get_lock(network_id):
            with locking.LockManager.get_lock('nsx-dhcp-edge-pool'):

                with db_api.CONTEXT_WRITER.using(context):
                    self.base_delete_subnet(context, id)

                if subnet.enable_dhcp:
                    # There is only DHCP port available
                    if len(ports) == 1:
                        port = ports.pop()
                        # This is done out of the transaction as it invokes
                        # update_port which interfaces with the NSX
                        self.ipam.delete_port(context, port['id'])

                    # Delete the DHCP edge service
                    filters = {'network_id': [network_id]}
                    remaining_subnets = self.get_subnets(context,
                                                         filters=filters)
                    if len(remaining_subnets) == 0:
                        self._cleanup_dhcp_edge_before_deletion(
                            context, network_id)
                        LOG.debug("Delete the DHCP service for network %s",
                                  network_id)
                        self.edge_manager.delete_dhcp_edge_service(context,
                                                                   network_id)
                    else:
                        # Update address group and delete the DHCP port only
                        self._update_dhcp_address(context, network_id)

    def _is_overlapping_reserved_subnets(self, subnet):
        """Return True if the subnet overlaps with reserved subnets.

        For the V plugin we have a limitation that we should not use
        some reserved ranges like: 169.254.128.0/17 and 169.254.1.0/24
        """
        # translate the given subnet to a range object
        data = subnet['subnet']

        if data['cidr'] not in (constants.ATTR_NOT_SPECIFIED, None):
            reserved_subnets = list(nsxv_constants.RESERVED_IPS)
            reserved_subnets.append(cfg.CONF.nsxv.vdr_transit_network)
            return edge_utils.is_overlapping_reserved_subnets(data['cidr'],
                                                              reserved_subnets)

        return False

    def _get_dhcp_ip_addr_from_subnet(self, context, subnet_id):
        dhcp_port_filters = {'fixed_ips': {'subnet_id': [subnet_id]},
                             'device_owner': [constants.DEVICE_OWNER_DHCP]}
        dhcp_ports = self.get_ports(context, filters=dhcp_port_filters)
        if dhcp_ports and dhcp_ports[0].get('fixed_ips'):
            return dhcp_ports[0]['fixed_ips'][0]['ip_address']

    def is_dhcp_metadata(self, context, subnet_id):
        try:
            subnet = self.get_subnet(context, subnet_id)
        except n_exc.SubnetNotFound:
            LOG.debug("subnet %s not found to determine its dhcp meta",
                      subnet_id)
            return False
        return bool(subnet['enable_dhcp'] and self.metadata_proxy_handler)

    def create_subnet_bulk(self, context, subnets):

        collection = "subnets"
        items = subnets[collection]
        new_subnets = []
        for item in items:
            try:
                s = self.create_subnet(context, item)
                new_subnets.append(s)
            except Exception as e:
                LOG.error('Unable to create bulk subnets. Failed to '
                          'create item %(item)s. Rolling back. '
                          'Error: %(e)s', {'item': item, 'e': e})
                for subnet in new_subnets:
                    s_id = subnet['id']
                    try:
                        self.delete_subnet(context, s_id)
                    except Exception:
                        LOG.error('Unable to delete subnet %s', s_id)
                raise
        return new_subnets

    def base_create_subnet(self, context, subnet):
        with locking.LockManager.get_lock('neutron-base-subnet'):
            return super(NsxVPluginV2, self).create_subnet(context, subnet)

    def create_subnet(self, context, subnet):
        """Create subnet on nsx_v provider network.

        If the subnet is created with DHCP enabled, and the network which
        the subnet is attached is not bound to an DHCP Edge, nsx_v will
        create the Edge and make sure the network is bound to the Edge
        """
        self._validate_host_routes_input(subnet)
        if subnet['subnet']['enable_dhcp']:
            self._validate_external_subnet(context,
                                           subnet['subnet']['network_id'])
            data = subnet['subnet']
            if (data.get('ip_version') == 6 or
                (data['cidr'] not in (constants.ATTR_NOT_SPECIFIED, None) and
                 netaddr.IPNetwork(data['cidr']).version == 6)):
                err_msg = _("No support for DHCP for IPv6")
                raise n_exc.InvalidInput(error_message=err_msg)
            if self._is_overlapping_reserved_subnets(subnet):
                err_msg = _("The requested subnet contains reserved IP's")
                raise n_exc.InvalidInput(error_message=err_msg)

        with locking.LockManager.get_lock(subnet['subnet']['network_id']):
            s = self.base_create_subnet(context, subnet)
            self._extension_manager.process_create_subnet(
                context, subnet['subnet'], s)
            if s['enable_dhcp']:
                try:
                    self._process_subnet_ext_attr_create(
                        session=context.session,
                        subnet_db=s,
                        subnet_req=data)
                    self._update_dhcp_service_with_subnet(context, s)
                except Exception:
                    with excutils.save_and_reraise_exception():
                        self.base_delete_subnet(context, s['id'])
        return s

    def _process_subnet_ext_attr_create(self, session, subnet_db,
                                        subnet_req):
        # Verify if dns search domain/dhcp mtu for subnet are configured
        dns_search_domain = subnet_req.get(
            ext_dns_search_domain.DNS_SEARCH_DOMAIN)
        dhcp_mtu = subnet_req.get(
            ext_dhcp_mtu.DHCP_MTU)
        if (not validators.is_attr_set(dns_search_domain) and
            not validators.is_attr_set(dhcp_mtu)):
            return
        if not validators.is_attr_set(dns_search_domain):
            dns_search_domain = None
        if not validators.is_attr_set(dhcp_mtu):
            dhcp_mtu = None
        sub_binding = nsxv_db.get_nsxv_subnet_ext_attributes(
            session=session,
            subnet_id=subnet_db['id'])
        # Create a subnet extensions for subnet if it does not exist
        if not sub_binding:
            nsxv_db.add_nsxv_subnet_ext_attributes(
                session=session,
                subnet_id=subnet_db['id'],
                dns_search_domain=dns_search_domain,
                dhcp_mtu=dhcp_mtu)
        # Else update only if a new values for subnet extensions are provided
        elif (sub_binding.dns_search_domain != dns_search_domain or
              sub_binding.dhcp_mtu != dhcp_mtu):
            nsxv_db.update_nsxv_subnet_ext_attributes(
                session=session,
                subnet_id=subnet_db['id'],
                dns_search_domain=dns_search_domain,
                dhcp_mtu=dhcp_mtu)
        subnet_db['dns_search_domain'] = dns_search_domain
        subnet_db['dhcp_mtu'] = dhcp_mtu

    def _process_subnet_ext_attr_update(self, session, subnet_db,
                                        subnet_req):
        update_dhcp_config = False
        # Update extended attributes for subnet
        if (ext_dns_search_domain.DNS_SEARCH_DOMAIN in subnet_req or
            ext_dhcp_mtu.DHCP_MTU in subnet_req):
            self._process_subnet_ext_attr_create(session,
                                                 subnet_db,
                                                 subnet_req)
            update_dhcp_config = True
        return update_dhcp_config

    def _update_routers_on_gateway_change(self, context, subnet_id,
                                          new_gateway):
        """Update all relevant router edges that the nexthop changed."""
        port_filters = {'device_owner': [l3_db.DEVICE_OWNER_ROUTER_GW],
                        'fixed_ips': {'subnet_id': [subnet_id]}}
        intf_ports = self.get_ports(context.elevated(),
                                    filters=port_filters)
        router_ids = [port['device_id'] for port in intf_ports]
        for router_id in router_ids:
            router_driver = self._find_router_driver(context, router_id)
            router_driver._update_nexthop(context, router_id, new_gateway)

    def update_subnet(self, context, id, subnet):
        # Lock the subnet so that no other conflicting action can occur on
        # the same subnet
        with locking.LockManager.get_lock('subnet-%s' % id):
            return self._safe_update_subnet(context, id, subnet)

    def _safe_update_subnet(self, context, id, subnet):
        s = subnet['subnet']
        subnet_obj = self._get_subnet_object(context, id)
        orig = self._make_subnet_dict(subnet_obj, fields=None, context=context)
        gateway_ip = orig['gateway_ip']
        enable_dhcp = orig['enable_dhcp']
        orig_host_routes = orig['host_routes']
        if s.get('enable_dhcp'):
            self._validate_external_subnet(context, orig['network_id'])
        self._validate_host_routes_input(subnet,
                                         orig_enable_dhcp=enable_dhcp,
                                         orig_host_routes=orig_host_routes)
        subnet = super(NsxVPluginV2, self).update_subnet(context, id, subnet)
        self._extension_manager.process_update_subnet(context, s, subnet)
        update_dhcp_config = self._process_subnet_ext_attr_update(
            context.session, subnet, s)
        if (gateway_ip != subnet['gateway_ip'] or update_dhcp_config or
            set(orig['dns_nameservers']) != set(subnet['dns_nameservers']) or
            orig_host_routes != subnet['host_routes'] or
            enable_dhcp and not subnet['enable_dhcp']):
            # Need to ensure that all of the subnet attributes will be reloaded
            # when creating the edge bindings. Without adding this the original
            # subnet details are provided.
            context.session.expire_all()
            # Update the edge
            network_id = subnet['network_id']
            self.edge_manager.update_dhcp_edge_bindings(context, network_id)
            # also update routers that use this subnet as their gateway
            if gateway_ip != subnet['gateway_ip']:
                self._update_routers_on_gateway_change(context, id,
                                                       subnet['gateway_ip'])
        if enable_dhcp != subnet['enable_dhcp']:
            self._update_subnet_dhcp_status(subnet, context)
        return subnet

    @staticmethod
    @resource_extend.extends([subnet_def.COLLECTION_NAME])
    def _extend_subnet_dict_extended_attributes(subnet_res, subnet_db):
        subnet_attr = subnet_db.get('nsxv_subnet_attributes')
        if subnet_attr:
            subnet_res['dns_search_domain'] = subnet_attr.dns_search_domain
            subnet_res['dhcp_mtu'] = subnet_attr.dhcp_mtu

    def _is_subnet_gw_a_vdr(self, context, subnet):
        filters = {'fixed_ips': {'subnet_id': [subnet['id']],
                                 'ip_address': [subnet['gateway_ip']]}}
        ports = self.get_ports(context, filters=filters)
        if ports and ports[0].get('device_id'):
            rtr_id = ports[0].get('device_id')
            rtr = self.get_router(context, rtr_id)
            if rtr and rtr.get('distributed'):
                return rtr_id

    def _update_subnet_dhcp_status(self, subnet, context):
        network_id = subnet['network_id']
        if subnet['enable_dhcp']:
            # Check if the network has one related dhcp edge
            resource_id = (vcns_const.DHCP_EDGE_PREFIX + network_id)[:36]
            edge_binding = nsxv_db.get_nsxv_router_binding(context.session,
                                                           resource_id)
            if edge_binding:
                # Create DHCP port
                port_dict = {'name': '',
                             'admin_state_up': True,
                             'network_id': network_id,
                             'tenant_id': subnet['tenant_id'],
                             'fixed_ips': [{'subnet_id': subnet['id']}],
                             'device_owner': constants.DEVICE_OWNER_DHCP,
                             'device_id': n_utils.get_dhcp_agent_device_id(
                                  network_id, 'nsxv'),
                             'mac_address': constants.ATTR_NOT_SPECIFIED
                             }
                self.create_port(context, {'port': port_dict})
            # First time binding network with dhcp edge
            else:
                with locking.LockManager.get_lock(subnet['network_id']):
                    self._update_dhcp_service_with_subnet(context, subnet)
                return
        else:
            # delete dhcp port
            filters = {'fixed_ips': {'subnet_id': [subnet['id']]}}
            ports = self.get_ports(context, filters=filters)
            for port in ports:
                if port["device_owner"] == constants.DEVICE_OWNER_DHCP:
                    self.ipam.delete_port(context, port['id'])
            # Delete the DHCP edge service
            network_id = subnet['network_id']
            filters = {'network_id': [network_id]}
            subnets = self.get_subnets(context, filters=filters)
            cleaup_edge = True
            for s in subnets:
                if s['enable_dhcp']:
                    cleaup_edge = False
            if cleaup_edge:
                self._cleanup_dhcp_edge_before_deletion(
                    context, network_id)
                LOG.debug("Delete the DHCP service for network %s",
                          network_id)
                self.edge_manager.delete_dhcp_edge_service(context, network_id)
                return
        self._update_dhcp_address(context, network_id)

    def _get_conflict_network_ids_by_overlapping(self, context, subnets):
        with locking.LockManager.get_lock('nsx-networking'):
            conflict_network_ids = []
            subnet_ids = [subnet['id'] for subnet in subnets]
            conflict_set = netaddr.IPSet(
                [subnet['cidr'] for subnet in subnets])
            subnets_qry = context.session.query(models_v2.Subnet).all()
            subnets_all = [subnet for subnet in subnets_qry
                           if subnet['id'] not in subnet_ids]
            for subnet in subnets_all:
                cidr_set = netaddr.IPSet([subnet['cidr']])
                if cidr_set & conflict_set:
                    conflict_network_ids.append(subnet['network_id'])
            return conflict_network_ids

    def _get_conflicting_networks_for_subnet(self, context, subnet):
        """Return a list if networks IDs conflicting with requested subnet

        The requested subnet cannot be placed on the same DHCP edge as the
        conflicting networks.
        A network will be conflicting with the current subnet if:
        1. overlapping ips
        2. provider networks with different physical network
        3. flat provider network with any other flat network
        4. if not share_edges_between_tenants: networks of different tenants

        """
        subnet_net = subnet['network_id']
        subnet_tenant = subnet['tenant_id']
        # The DHCP for network with different physical network can not be used
        # The flat network should be located in different DHCP
        conflicting_networks = []
        all_networks = self.get_networks(context.elevated(),
                                         fields=['id', 'tenant_id'])
        phy_net = nsxv_db.get_network_bindings(context.session, subnet_net)
        if phy_net:
            binding_type = phy_net[0]['binding_type']
            phy_uuid = phy_net[0]['phy_uuid']
            for net_id in all_networks:
                p_net = nsxv_db.get_network_bindings(context.session,
                                                    net_id['id'])
                if (p_net and binding_type == p_net[0]['binding_type'] and
                    binding_type == c_utils.NsxVNetworkTypes.FLAT):
                    conflicting_networks.append(net_id['id'])
                elif (p_net and phy_uuid != p_net[0]['phy_uuid']):
                    conflicting_networks.append(net_id['id'])

        # get conflicting networks of other tenants
        if not cfg.CONF.nsxv.share_edges_between_tenants:
            for another_net in all_networks:
                if (another_net['id'] != subnet_net and
                    another_net['tenant_id'] != subnet_tenant):
                    conflicting_networks.append(another_net['id'])

        # get all of the subnets on the network, there may be more than one
        filters = {'network_id': [subnet_net]}
        subnets = super(NsxVPluginV2, self).get_subnets(context.elevated(),
                                                        filters=filters)
        # Query all networks with overlap subnet
        if cfg.CONF.allow_overlapping_ips:
            conflicting_networks.extend(
                self._get_conflict_network_ids_by_overlapping(
                    context.elevated(), subnets))

        conflicting_networks = list(set(conflicting_networks))
        return conflicting_networks

    def _get_edge_id_by_rtr_id(self, context, rtr_id):
        binding = nsxv_db.get_nsxv_router_binding(
            context.session,
            rtr_id)

        if binding:
            return binding['edge_id']

    def _get_edge_id_and_az_by_rtr_id(self, context, rtr_id):
        binding = nsxv_db.get_nsxv_router_binding(
            context.session,
            rtr_id)

        if binding:
            return binding['edge_id'], binding['availability_zone']
        return None, None

    def _update_dhcp_service_new_edge(self, context, resource_id):
        edge_id, az_name = self._get_edge_id_and_az_by_rtr_id(
            context, resource_id)
        if edge_id:
            with locking.LockManager.get_lock(str(edge_id)):
                if self.metadata_proxy_handler:
                    LOG.debug('Update metadata for resource %s az=%s',
                              resource_id, az_name)
                    md_proxy = self.get_metadata_proxy_handler(az_name)
                    if md_proxy:
                        md_proxy.configure_router_edge(context, resource_id)

                self.setup_dhcp_edge_fw_rules(context, self,
                                              resource_id)

    def _update_dhcp_service_with_subnet(self, context, subnet):
        network_id = subnet['network_id']
        # Create DHCP port
        port_dict = {'name': '',
                     'admin_state_up': True,
                     'network_id': network_id,
                     'tenant_id': subnet['tenant_id'],
                     'fixed_ips': [{'subnet_id': subnet['id']}],
                     'device_owner': constants.DEVICE_OWNER_DHCP,
                     'device_id': n_utils.get_dhcp_agent_device_id(
                          network_id, 'nsxv'),
                     'mac_address': constants.ATTR_NOT_SPECIFIED
                     }
        self.create_port(context, {'port': port_dict})

        try:
            self.edge_manager.create_dhcp_edge_service(context, network_id,
                                                       subnet)
            # Create all dhcp ports within the network
            self._update_dhcp_address(context, network_id)

        except Exception:
            with excutils.save_and_reraise_exception():
                LOG.exception("Failed to update DHCP for subnet %s",
                              subnet['id'])

    def setup_dhcp_edge_fw_rules(self, context, plugin, router_id):
        rules = []
        loose_ver = version.LooseVersion(self.nsx_v.vcns.get_version())
        if loose_ver < version.LooseVersion('6.3.2'):
            # For these versions the raw icmp rule will not work due to
            # backend bug. Workaround: use applications, but since
            # application ids can change, we look them up by application name
            try:
                application_ids = plugin.nsx_v.get_icmp_echo_application_ids()

                rules = [{"name": "ICMPPing",
                          "enabled": True,
                          "action": "allow",
                          "application": {
                              "applicationId": application_ids}},
                         {"name": "DHCPReply",
                          "action": "allow",
                          "enabled": True,
                          "protocol": "udp",
                          "source_port": "68",
                          "destination_port": "67"}]

            except Exception as e:
                LOG.error(
                    'Could not find ICMP Echo application. Exception %s',
                    e)
        else:
            # For newer versions, we can use the raw icmp rule
            rules = [{"name": "ICMPPing",
                      "enabled": True,
                      "action": "allow",
                      "protocol": "icmp",
                      "icmp_type": 8},
                     {"name": "DHCPReply",
                      "action": "allow",
                      "enabled": True,
                      "protocol": "udp",
                      "source_port": "68",
                      "destination_port": "67"}]

        if plugin.metadata_proxy_handler:
            rules += nsx_v_md_proxy.get_router_fw_rules()

        try:
            edge_utils.update_firewall(plugin.nsx_v, context, router_id,
                                       {'firewall_rule_list': rules},
                                       allow_external=False)
        except Exception as e:
            # On failure, log that we couldn't configure the firewall on the
            # Edge appliance. This won't break the DHCP functionality
            LOG.error(
                'Could not set up DHCP Edge firewall. Exception %s', e)

    def _create_network_dhcp_address_group(self, context, network_id):
        """Create dhcp address group for subnets attached to the network."""

        filters = {'network_id': [network_id],
                   'device_owner': [constants.DEVICE_OWNER_DHCP]}
        ports = self.get_ports(context, filters=filters)

        filters = {'network_id': [network_id], 'enable_dhcp': [True]}
        subnets = self.get_subnets(context, filters=filters)

        address_groups = []
        for subnet in subnets:
            address_group = {}
            ip_found = False
            for port in ports:
                fixed_ips = port['fixed_ips']
                for fip in fixed_ips:
                    s_id = fip['subnet_id']
                    ip_addr = fip['ip_address']
                    if s_id == subnet['id'] and self._is_valid_ip(ip_addr):
                        address_group['primaryAddress'] = ip_addr
                        ip_found = True
                        break
            if ip_found:
                net = netaddr.IPNetwork(subnet['cidr'])
                address_group['subnetPrefixLength'] = str(net.prefixlen)
                address_groups.append(address_group)
        LOG.debug("Update the DHCP address group to %s", address_groups)
        return address_groups

    def _validate_router_size(self, router):
        # Check if router-size is specified. router-size can only be specified
        # for an exclusive non-distributed router; else raise a BadRequest
        # exception.
        r = router['router']
        if validators.is_attr_set(r.get(ROUTER_SIZE)):
            if r.get('router_type') == constants.SHARED:
                msg = _("Cannot specify router-size for shared router")
                raise n_exc.BadRequest(resource="router", msg=msg)
            if r.get('distributed') is True:
                msg = _("Cannot specify router-size for distributed router")
                raise n_exc.BadRequest(resource="router", msg=msg)
        else:
            if r.get('router_type') == nsxv_constants.EXCLUSIVE:
                r[ROUTER_SIZE] = cfg.CONF.nsxv.exclusive_router_appliance_size

    def _get_router_flavor_profile(self, context, flavor_id):
        flv_plugin = directory.get_plugin(plugin_const.FLAVORS)
        if not flv_plugin:
            msg = _("Flavors plugin not found")
            raise n_exc.BadRequest(resource="router", msg=msg)

        # Will raise FlavorNotFound if doesn't exist
        fl_db = flavors_plugin.FlavorsPlugin.get_flavor(
            flv_plugin, context, flavor_id)
        if fl_db['service_type'] != plugin_const.L3:
            raise n_exc.InvalidFlavorServiceType(
                service_type=fl_db['service_type'])

        if not fl_db['enabled']:
            raise flav_exc.FlavorDisabled()

        # get the profile (Currently only 1 is supported, so take the first)
        if not fl_db['service_profiles']:
            return
        profile_id = fl_db['service_profiles'][0]

        return flavors_plugin.FlavorsPlugin.get_service_profile(
            flv_plugin,
            context,
            profile_id)

    def _get_flavor_metainfo_from_profile(self, flavor_id, flavor_profile):
        if not flavor_profile:
            return {}
        metainfo_string = flavor_profile.get('metainfo').replace("'", "\"")
        try:
            metainfo = jsonutils.loads(metainfo_string)
            if not isinstance(metainfo, dict):
                LOG.warning("Skipping router flavor %(flavor)s metainfo "
                            "[%(metainfo)s]: expected a dictionary",
                            {'flavor': flavor_id,
                             'metainfo': metainfo_string})
                metainfo = {}
        except ValueError as e:
            LOG.warning("Error reading router flavor %(flavor)s metainfo "
                        "[%(metainfo)s]: %(error)s",
                        {'flavor': flavor_id,
                         'metainfo': metainfo_string,
                         'error': e})
            metainfo = {}
        return metainfo

    def get_flavor_metainfo(self, context, flavor_id):
        """Retrieve metainfo from first profile of specified flavor"""
        flavor_profile = self._get_router_flavor_profile(context, flavor_id)
        return self._get_flavor_metainfo_from_profile(flavor_id,
                                                      flavor_profile)

    def _get_router_config_from_flavor(self, context, router):
        """Validate the router flavor and initialize router data

        Validate that the flavor is legit, and that contradicting configuration
        does not exist.
        Also update the router data to reflect the selected flavor.
        """
        if not validators.is_attr_set(router.get('flavor_id')):
            return
        metainfo = self.get_flavor_metainfo(context, router['flavor_id'])

        # Go over the attributes of the metainfo
        allowed_keys = [ROUTER_SIZE, 'router_type', 'distributed',
                        az_def.AZ_HINTS]
        # This info will be used later on
        # and is not part of standard router config
        future_use_keys = ['syslog']
        for k, v in metainfo.items():
            if k in allowed_keys:
                #special case for availability zones hints which are an array
                if k == az_def.AZ_HINTS:
                    if not isinstance(v, list):
                        v = [v]
                    # The default az hists is an empty array
                    if (validators.is_attr_set(router.get(k)) and
                        len(router[k]) > 0):
                        msg = (_("Cannot specify %s if the flavor profile "
                                 "defines it") % k)
                        raise n_exc.BadRequest(resource="router", msg=msg)

                elif validators.is_attr_set(router.get(k)) and router[k] != v:
                    msg = _("Cannot specify %s if the flavor defines it") % k
                    raise n_exc.BadRequest(resource="router", msg=msg)
                # Legal value
                router[k] = v
            elif k in future_use_keys:
                pass
            else:
                LOG.warning("Skipping router flavor metainfo [%(k)s:%(v)s]"
                            ":unsupported field",
                            {'k': k, 'v': v})

    def create_router(self, context, router, allow_metadata=True):
        r = router['router']
        self._get_router_config_from_flavor(context, r)
        self._decide_router_type(context, r)
        self._validate_router_size(router)
        self._validate_availability_zones_in_obj(context, 'router', r)

        # First extract the gateway info in case of updating
        # gateway before edge is deployed.
        # TODO(berlin): admin_state_up and routes update
        gw_info = self._extract_external_gw(context, router)
        lrouter = super(NsxVPluginV2, self).create_router(context, router)

        with db_api.CONTEXT_WRITER.using(context):
            router_db = self._get_router(context, lrouter['id'])
            self._process_extra_attr_router_create(context, router_db, r)
            self._process_nsx_router_create(context, router_db, r)
            self._process_router_flavor_create(context, router_db, r)
            try:
                router_driver = self._get_router_driver(context, router_db)
            except Exception:
                LOG.exception("Failed to create router %s", router)
                with excutils.save_and_reraise_exception():
                    self.delete_router(context, lrouter['id'])

        with db_api.CONTEXT_READER.using(context):
            lrouter = super(NsxVPluginV2, self).get_router(context,
                                                           lrouter['id'])
        try:
            if router_driver.get_type() == nsxv_constants.EXCLUSIVE:
                router_driver.create_router(
                    context, lrouter,
                    appliance_size=r.get(ROUTER_SIZE),
                    allow_metadata=(allow_metadata and
                                    self.metadata_proxy_handler))
            else:
                router_driver.create_router(
                    context, lrouter,
                    allow_metadata=(allow_metadata and
                                    self.metadata_proxy_handler))
            if gw_info != constants.ATTR_NOT_SPECIFIED and gw_info:
                self._update_router_gw_info(
                    context, lrouter['id'], gw_info)
        except Exception:
            LOG.exception("Failed to create router %s", router)
            with excutils.save_and_reraise_exception():
                self.delete_router(context, lrouter['id'])

        # re-read the router with the updated data, and return it
        with db_api.CONTEXT_READER.using(context):
            return self.get_router(context, lrouter['id'])

    def _validate_router_migration(self, context, router_id,
                                   new_router_type, router):
        if new_router_type == 'shared':
            # shared router cannot have static routes
            # verify that the original router did not have static routes
            err_msg = _('Unable to create a shared router with static routes')
            routes = self._get_extra_routes_by_router_id(context, router_id)
            if len(routes) > 0:
                raise n_exc.InvalidInput(error_message=err_msg)
            # verify that the updated router does not have static routes
            if (validators.is_attr_set(router.get("routes")) and
                len(router['routes']) > 0):
                raise n_exc.InvalidInput(error_message=err_msg)

            # shared router cannot be attached to a loadbalancer
            edge_id = self._get_edge_id_by_rtr_id(context, router_id)
            if edge_id:
                lb_bind = nsxv_db.get_nsxv_lbaas_loadbalancer_binding_by_edge(
                    context.session, edge_id)
                if lb_bind:
                    err_msg = _('Unable to create a shared router with a load '
                                'balancer')
                    raise n_exc.InvalidInput(error_message=err_msg)

            # shared router cannot be attached to a fwaas
            if (self.fwaas_callbacks and
                self.fwaas_callbacks.should_apply_firewall_to_router(
                    context, router, router_id)):
                err_msg = _('Unable to create a shared router with FWaaS')
                raise n_exc.InvalidInput(error_message=err_msg)

    def update_router(self, context, router_id, router):
        with locking.LockManager.get_lock('router-%s' % router_id):
            return self._safe_update_router(context, router_id, router)

    def _safe_update_router(self, context, router_id, router):
        # Validate that the gateway information is relevant
        gw_info = self._extract_external_gw(context, router, is_extract=False)
        # Toggling the distributed flag is not supported
        if 'distributed' in router['router']:
            r = self.get_router(context, router_id)
            if r['distributed'] != router['router']['distributed']:
                err_msg = _('Unable to update distributed mode')
                raise n_exc.InvalidInput(error_message=err_msg)

        # Toggling router type is supported only for non-distributed router
        elif 'router_type' in router['router']:
            r = self.get_router(context, router_id)
            if r.get('router_type') != router['router']['router_type']:
                if r["distributed"]:
                    err_msg = _('Unable to update distributed mode')
                    raise n_exc.InvalidInput(error_message=err_msg)
                # should migrate the router because its type changed
                new_router_type = router['router']['router_type']
                self._validate_router_size(router)
                self._validate_router_migration(
                    context, router_id, new_router_type, r)

                # remove the router from the old pool, and free resources
                old_router_driver = \
                    self._router_managers.get_tenant_router_driver(
                        context, r['router_type'])
                old_router_driver.detach_router(context, router_id, router)

                # update the router-type
                with db_api.CONTEXT_WRITER.using(context):
                    router_db = self._get_router(context, router_id)
                    self._process_nsx_router_create(
                        context, router_db, router['router'])

                # update availability zone
                router['router']['availability_zone_hints'] = r.get(
                    'availability_zone_hints')

                # add the router to the new pool
                appliance_size = router['router'].get(ROUTER_SIZE)
                new_router_driver = \
                    self._router_managers.get_tenant_router_driver(
                        context, new_router_type)
                new_router_driver.attach_router(
                    context,
                    router_id,
                    router,
                    appliance_size=appliance_size)
                # continue to update the router with the new driver
                # but remove the router-size that was already updated
                router['router'].pop(ROUTER_SIZE, None)

        if (validators.is_attr_set(gw_info) and
            not gw_info.get('enable_snat', cfg.CONF.enable_snat_by_default)):
            router_ports = self._get_router_interfaces(context, router_id)
            for port in router_ports:
                for fip in port['fixed_ips']:
                    self._validate_address_scope_for_router_interface(
                        context.elevated(), router_id,
                        gw_info['network_id'], fip['subnet_id'])

        router_driver = self._find_router_driver(context, router_id)
        return router_driver.update_router(context, router_id, router)

    def _check_router_in_use(self, context, router_id):
        with db_api.CONTEXT_READER.using(context):
            # Ensure that the router is not used
            router_filter = {'router_id': [router_id]}
            fips = self.get_floatingips_count(context.elevated(),
                                              filters=router_filter)
            if fips:
                raise l3_exc.RouterInUse(router_id=router_id)

            device_filter = {'device_id': [router_id],
                             'device_owner': [l3_db.DEVICE_OWNER_ROUTER_INTF]}
            ports = self.get_ports_count(context.elevated(),
                                         filters=device_filter)
            if ports:
                raise l3_exc.RouterInUse(router_id=router_id)

            if nsxv_db.get_nsxv_internal_edge_by_router(
                context.elevated().session, router_id):
                msg = _("Cannot delete internal router %s") % router_id
                raise n_exc.InvalidInput(error_message=msg)

    def delete_router(self, context, id):
        self._check_router_in_use(context, id)
        router_driver = self._find_router_driver(context, id)
        # Clear vdr's gw relative components if the router has gw info
        if router_driver.get_type() == "distributed":
            router = self.get_router(context, id)
            if router.get(l3_apidef.EXTERNAL_GW_INFO):
                try:
                    router_driver._update_router_gw_info(context, id, {})
                except Exception as e:
                    # Do not fail router deletion
                    LOG.error("Failed to remove router %(rtr)s GW info before "
                              "deletion: %(e)s", {'e': e, 'rtr': id})
        super(NsxVPluginV2, self).delete_router(context, id)
        router_driver.delete_router(context, id)

    def get_availability_zone_name_by_edge(self, context, edge_id):
        az_name = nsxv_db.get_edge_availability_zone(
            context.session, edge_id)
        if az_name:
            return az_name
        # fallback
        return nsx_az.DEFAULT_NAME

    def get_network_availability_zones(self, net_db):
        context = n_context.get_admin_context()
        return self._get_network_availability_zones(context, net_db)

    def _get_network_availability_zones(self, context, net_db):
        """Return availability zones which a network belongs to.

        Return only the actual az the dhcp edge is deployed on.
        If there is no edge - the availability zones list is empty.
        """
        resource_id = (vcns_const.DHCP_EDGE_PREFIX + net_db["id"])[:36]
        dhcp_edge_binding = nsxv_db.get_nsxv_router_binding(
            context.session, resource_id)
        if dhcp_edge_binding:
            return [dhcp_edge_binding['availability_zone']]
        return []

    def get_router_availability_zones(self, router):
        """Return availability zones which a router belongs to.

        Return only the actual az the router edge is deployed on.
        If there is no edge - the availability zones list is empty.
        """
        context = n_context.get_admin_context()
        binding = nsxv_db.get_nsxv_router_binding(
            context.session, router['id'])
        if binding:
            return [binding['availability_zone']]
        return []

    def _process_router_flavor_create(self, context, router_db, r):
        """Update the router DB structure with the flavor ID upon creation
        """
        if validators.is_attr_set(r.get('flavor_id')):
            router_db.flavor_id = r['flavor_id']

    @staticmethod
    @resource_extend.extends([l3_apidef.ROUTERS])
    def add_flavor_id(router_res, router_db):
        router_res['flavor_id'] = router_db['flavor_id']

    def get_router(self, context, id, fields=None):
        router = super(NsxVPluginV2, self).get_router(context, id, fields)
        if router.get("distributed") and 'router_type' in router:
            del router['router_type']
        if router.get("router_type") == nsxv_constants.EXCLUSIVE:
            binding = nsxv_db.get_nsxv_router_binding(context.session,
                                                      router.get("id"))
            if binding:
                router[ROUTER_SIZE] = binding.get("appliance_size")
            else:
                LOG.error("No binding for router %s", id)
        return router

    def _get_external_attachment_info(self, context, router):
        gw_port = router.gw_port
        ipaddress = None
        netmask = None
        nexthop = None

        if gw_port:
            # TODO(berlin): we can only support gw port with one fixed ip at
            # present.
            if gw_port.get('fixed_ips'):
                ipaddress = gw_port['fixed_ips'][0]['ip_address']
                subnet_id = gw_port['fixed_ips'][0]['subnet_id']
                subnet = self.get_subnet(context.elevated(), subnet_id)
                nexthop = subnet['gateway_ip']

            network_id = gw_port.get('network_id')
            if network_id:
                ext_net = self._get_network(context, network_id)
                if not ext_net.external:
                    msg = (_("Network '%s' is not a valid external "
                             "network") % network_id)
                    raise n_exc.BadRequest(resource='router', msg=msg)
                if ext_net.subnets:
                    netmask = set([str(ext_subnet.cidr)
                                   for ext_subnet in ext_net.subnets])

        return (ipaddress, netmask, nexthop)

    def _add_network_info_for_routes(self, context, routes, ports):
        for route in routes:
            for port in ports:
                for ip in port['fixed_ips']:
                    subnet = self.get_subnet(context.elevated(),
                                             ip['subnet_id'])
                    if netaddr.all_matching_cidrs(
                        route['nexthop'], [subnet['cidr']]):
                        net = self.get_network(context.elevated(),
                                               subnet['network_id'])
                        route['network_id'] = net['id']
                        if net.get(extnet_apidef.EXTERNAL):
                            route['external'] = True

    def _prepare_edge_extra_routes(self, context, router_id):
        routes = self._get_extra_routes_by_router_id(context, router_id)
        filters = {'device_id': [router_id]}
        ports = self.get_ports(context.elevated(), filters)
        self._add_network_info_for_routes(context, routes, ports)
        return routes

    def _update_routes(self, context, router_id, nexthop):
        routes = self._prepare_edge_extra_routes(context, router_id)
        edge_utils.update_routes(self.nsx_v, context, router_id,
                                 routes, nexthop)

    def _update_current_gw_port(self, context, router_id, router, ext_ips):
        """Override this function in order not to call plugins' update_port
        since the actual backend work was already done by the router driver,
        and it may cause a deadlock.
        """

        port_data = {'fixed_ips': ext_ips}
        updated_port = super(NsxVPluginV2, self).update_port(
            context, router.gw_port['id'], {'port': port_data})
        self._extension_manager.process_update_port(
            context, port_data, updated_port)
        registry.publish(resources.ROUTER_GATEWAY,
                         events.AFTER_UPDATE,
                         self._update_current_gw_port,
                         payload=events.DBEventPayload(
                             context, resource_id=router_id,
                             states=(router,), metadata={
                                 'network_id': router.gw_port.network_id,
                                 'updated_port': updated_port
                             }))

    def _update_router_gw_info(self, context, router_id, info,
                               is_routes_update=False,
                               force_update=False):
        with db_api.CONTEXT_WRITER.using(context):
            # use the reader context a this might be called from create_router
            router_db = self._get_router(context, router_id)
            router_driver = self._get_router_driver(context, router_db)

        if info:
            try:
                ext_ips = info.get('external_fixed_ips')
                network_id = info.get('network_id')

                org_enable_snat = router_db.enable_snat
                # Ensure that a router cannot have SNAT disabled if there are
                # floating IP's assigned
                if ('enable_snat' in info and
                    org_enable_snat != info.get('enable_snat') and
                    info.get('enable_snat') is False and
                    self.router_gw_port_has_floating_ips(context, router_id)):
                    msg = _("Unable to set SNAT disabled. Floating IPs "
                            "assigned")
                    raise n_exc.InvalidInput(error_message=msg)

                # for multiple external subnets support, we need to set gw
                # port first on subnet which has gateway. If can't get one
                # subnet with gateway or allocate one available ip from
                # subnet, we would just enter normal logic and admin should
                # exactly know what he did.
                if (not ext_ips and network_id and
                    (not router_db.gw_port or
                     not router_db.gw_port.get('fixed_ips'))):
                    net_id_filter = {'network_id': [network_id]}
                    subnets = self.get_subnets(context, filters=net_id_filter)
                    fixed_subnet = True
                    if len(subnets) <= 1:
                        fixed_subnet = False
                    else:
                        for subnet in subnets:
                            if ipv6_utils.is_auto_address_subnet(subnet):
                                fixed_subnet = False
                    if fixed_subnet:
                        for subnet in subnets:
                            if not subnet['gateway_ip']:
                                continue
                            try:
                                info['external_fixed_ips'] = [{
                                    'subnet_id': subnet['id']}]
                                return router_driver._update_router_gw_info(
                                    context, router_id, info,
                                    is_routes_update=is_routes_update)
                            except n_exc.IpAddressGenerationFailure:
                                del info['external_fixed_ips']
                        LOG.warning("Cannot get one subnet with gateway "
                                    "to allocate one available gw ip")
                router_driver._update_router_gw_info(
                    context, router_id, info,
                    is_routes_update=is_routes_update,
                    force_update=force_update)
            except vsh_exc.VcnsApiException:
                with excutils.save_and_reraise_exception():
                    LOG.error("Failed to update gw_info %(info)s on "
                              "router %(router_id)s",
                              {'info': str(info),
                               'router_id': router_id})
                    router_driver._update_router_gw_info(
                        context, router_id, {},
                        is_routes_update=is_routes_update,
                        force_update=force_update)
        else:
            router_driver._update_router_gw_info(
                context, router_id, info,
                is_routes_update=is_routes_update,
                force_update=force_update)

    def _get_internal_network_ids_by_router(self, context, router_id):
        ports_qry = context.session.query(models_v2.Port)
        intf_ports = ports_qry.filter_by(
            device_id=router_id,
            device_owner=l3_db.DEVICE_OWNER_ROUTER_INTF).all()
        intf_net_ids = list(set([port['network_id'] for port in intf_ports]))
        return intf_net_ids

    def _get_address_groups(self, context, router_id, network_id):
        address_groups = []
        ports = self._get_router_interface_ports_by_network(
            context, router_id, network_id)
        for port in ports:
            address_group = {}
            gateway_ip = port['fixed_ips'][0]['ip_address']
            subnet = self.get_subnet(context,
                                     port['fixed_ips'][0]['subnet_id'])
            prefixlen = str(netaddr.IPNetwork(subnet['cidr']).prefixlen)
            address_group['primaryAddress'] = gateway_ip
            address_group['subnetPrefixLength'] = prefixlen
            address_groups.append(address_group)
        return address_groups

    def _get_dnat_rules(self, context, router):
        fip_qry = context.session.query(l3_db_models.FloatingIP)
        fip_db = fip_qry.filter_by(router_id=router['id']).all()

        dnat = [{'dst': fip.floating_ip_address,
                 'translated': fip.fixed_ip_address}
                for fip in fip_db if fip.fixed_port_id]
        return dnat

    def _get_nat_rules(self, context, router):
        snat = []

        dnat = self._get_dnat_rules(context, router)

        gw_port = router.gw_port
        if gw_port and gw_port.get('fixed_ips') and router.enable_snat:
            snat_ip = gw_port['fixed_ips'][0]['ip_address']
            subnets = self._load_router_subnet_cidrs_from_db(
                context.elevated(), router['id'])
            gw_address_scope = self._get_network_address_scope(
                context.elevated(), gw_port['network_id'])
            for subnet in subnets:
                # Do not build NAT rules for v6
                if subnet.get('ip_version') == 6:
                    continue
                # if the subnets address scope is the same as the gateways:
                # no need for SNAT
                subnet_address_scope = self._get_subnetpool_address_scope(
                    context.elevated(), subnet['subnetpool_id'])
                if (gw_address_scope and
                    gw_address_scope == subnet_address_scope):
                    LOG.info("No need for SNAT rule for router %(router)s "
                             "and subnet %(subnet)s because they use the "
                             "same address scope %(addr_scope)s.",
                             {'router': router['id'],
                              'subnet': subnet['id'],
                              'addr_scope': gw_address_scope})
                    continue
                snat.append(self._get_default_nat_rule(
                    context, router['id'], subnet, snat_ip))
        return (snat, dnat)

    def _get_default_nat_rule(self, context, router_id, subnet, snat_ip):
        binding = nsxv_db.get_nsxv_router_binding(context.session, router_id)
        bind_to_all = False
        if binding:
            azs = nsx_az.NsxVAvailabilityZones()
            az = azs.get_availability_zone(binding['availability_zone'])
            bind_to_all = az.bind_floatingip_to_all_interfaces
        rule = {'src': subnet['cidr'],
                'translated': snat_ip}
        if not bind_to_all:
            rule['vnic_index'] = vcns_const.EXTERNAL_VNIC_INDEX
        return rule

    def _get_nosnat_subnets_fw_rules(self, context, router, subnets=None):
        """Open edge firewall holes for nosnat subnets to do static routes."""
        no_snat_fw_rules = []
        gw_port = router.gw_port
        if gw_port and not router.enable_snat:
            subnet_cidrs = self._find_router_subnets_cidrs(context.elevated(),
                                                           router['id'],
                                                           subnets)
            if subnet_cidrs:
                no_snat_fw_rules.append({
                    'name': NO_SNAT_RULE_NAME,
                    'action': 'allow',
                    'enabled': True,
                    'source_vnic_groups': ["external"],
                    'destination_ip_address': subnet_cidrs})
        return no_snat_fw_rules

    def _get_allocation_pools_fw_rule(self, context, router, subnets=None):
        """Get the firewall rule for the default gateway address pool

        Return the firewall rule that should be added in order to allow
        not SNAT-ed traffic to external gateway with the same address scope as
        the interfaces
        """
        gw_port = router.gw_port
        if not gw_port or not router.enable_snat:
            return

        gw_address_scope = self._get_network_address_scope(
            context.elevated(), gw_port['network_id'])
        if gw_address_scope is None:
            return

        if not subnets:
            subnets = self._load_router_subnet_cidrs_from_db(
                context.elevated(), router['id'])
        no_nat_cidrs = []
        for subnet in subnets:
            # if the subnets address scope is the same as the gateways:
            # we should add it to the rule
            subnet_address_scope = self._get_subnetpool_address_scope(
                context.elevated(), subnet['subnetpool_id'])
            if (gw_address_scope == subnet_address_scope):
                no_nat_cidrs.append(subnet['cidr'])

        if no_nat_cidrs:
            return {'name': ALLOCATION_POOL_RULE_NAME,
                    'action': 'allow',
                    'enabled': True,
                    'source_vnic_groups': ["external"],
                    'destination_ip_address': no_nat_cidrs}

    def _get_dnat_fw_rule(self, context, router):
        # Get FW rule to open dnat firewall flows
        dnat_rules = self._get_dnat_rules(context, router)
        dnat_cidrs = [rule['dst'] for rule in dnat_rules]
        if dnat_cidrs:
            return {
                'name': DNAT_RULE_NAME,
                'action': 'allow',
                'enabled': True,
                'destination_ip_address': dnat_cidrs}

    def _get_subnet_fw_rules(self, context, router, subnets=None):
        # Get FW rule/s to open subnets firewall flows and static routes
        # relative flows
        fw_rules = []
        subnet_cidrs_per_ads = self._find_router_subnets_cidrs_per_addr_scope(
            context.elevated(), router['id'], subnets=subnets)
        routes = self._get_extra_routes_by_router_id(context, router['id'])
        routes_dest = [route['destination'] for route in routes]
        for subnet_cidrs in subnet_cidrs_per_ads:
            # create a rule to allow east-west traffic between subnets on this
            # address scope
            # Also add the static routes to each address scope
            ips = subnet_cidrs + routes_dest
            fw_rules.append({
                'name': SUBNET_RULE_NAME,
                'action': 'allow',
                'enabled': True,
                'source_ip_address': ips,
                'destination_ip_address': ips})
        return fw_rules

    def _update_nat_rules(self, context, router, router_id=None):
        snat, dnat = self._get_nat_rules(context, router)
        if not router_id:
            router_id = router['id']
        edge_utils.update_nat_rules(
            self.nsx_v, context, router_id, snat, dnat)

    def recalculate_snat_rules_for_router(self, context, router, subnets):
        """Recalculate router snat rules for specific subnets.
        Invoked when subnetpool address scope changes.
        """
        # Recalculate all nat rules for all subnets of the router
        router_db = self._get_router(context, router['id'])
        self._update_nat_rules(context, router_db)

    def recalculate_fw_rules_for_router(self, context, router, subnets):
        """Recalculate router fw rules for specific subnets.
        Invoked when subnetpool address scope changes.
        """
        # Recalculate all fw rules for all subnets of the router
        router_db = self._get_router(context, router['id'])
        self._update_subnets_and_dnat_firewall(context, router_db)

    def _check_intf_number_of_router(self, context, router_id):
        intf_ports = self._get_port_by_device_id(
            context, router_id, l3_db.DEVICE_OWNER_ROUTER_INTF)
        if len(intf_ports) >= (vcns_const.MAX_INTF_NUM):
            err_msg = _("Interfaces number on router: %(router_id)s "
                        "has reached the maximum %(number)d which NSXv can "
                        "support. Please use vdr if you want to add unlimited "
                        "interfaces") % {'router_id': router_id,
                                         'number': vcns_const.MAX_INTF_NUM}
            raise nsx_exc.ServiceOverQuota(overs="router-interface-add",
                                           err_msg=err_msg)

    def _update_router_admin_state(self, context,
                                   router_id, router_type, admin_state):
        # Collecting all router interfaces and updating the connection status
        # for each one to reflect the router admin-state-up status.
        intf_net_ids = (
            self._get_internal_network_ids_by_router(context, router_id))
        edge_id = self._get_edge_id_by_rtr_id(context, router_id)
        if not edge_id:
            LOG.warning("Cannot update router %s admin state: no edge id "
                        "found", router_id)
        with locking.LockManager.get_lock(edge_id):
            for network_id in intf_net_ids:
                address_groups = (
                    self._get_address_groups(context, router_id, network_id))
                update_args = (self.nsx_v, context, router_id, network_id,
                               address_groups, admin_state)
                if router_type == 'distributed':
                    edge_utils.update_vdr_internal_interface(*update_args)
                else:
                    edge_utils.update_internal_interface(*update_args)

    def _get_interface_info(self, context, interface_info):
        is_port, is_sub = self._validate_interface_info(interface_info)
        if is_port:
            port = self._check_router_port(context,
                                           interface_info['port_id'], '')
            subnet_id = port['fixed_ips'][0]['subnet_id']
            net_id = port['network_id']
        elif is_sub:
            subnet_id = interface_info['subnet_id']
            net_id = self.get_subnet(
                context, subnet_id)['network_id']
        return net_id, subnet_id

    def add_router_interface(self, context, router_id, interface_info):
        router = self.get_router(context, router_id)
        net_id, subnet_id = self._get_interface_info(context, interface_info)
        network = self.get_network(context.elevated(), net_id)
        # Do not support external subnet/port as a router interface
        if network.get(extnet_apidef.EXTERNAL):
            msg = _("cannot add an external subnet/port as a router interface")
            raise n_exc.InvalidInput(error_message=msg)

        snat_disabled = (router[l3_apidef.EXTERNAL_GW_INFO] and
                         not router[l3_apidef.EXTERNAL_GW_INFO]['enable_snat'])
        if snat_disabled and subnet_id:
            gw_network_id = router[l3_apidef.EXTERNAL_GW_INFO]['network_id']
            self._validate_address_scope_for_router_interface(
                context.elevated(), router_id, gw_network_id, subnet_id)

        router_driver = self._find_router_driver(context, router_id)
        try:
            return router_driver.add_router_interface(
                context, router_id, interface_info)
        except vsh_exc.VcnsApiException as e:
            json_response = jsonutils.loads(e.response)
            details = json_response.get('details')
            msg = details or e.response
            LOG.error("Failed to add interface_info %(info)s on "
                      "router %(router_id)s: %(e)s",
                      {'info': str(interface_info),
                       'router_id': router_id,
                       'e': msg})
            try:
                router_driver.remove_router_interface(
                    context, router_id, interface_info)
            except Exception:
                # Rollback may fail if creation failed too early
                pass
            # Log the original error
            raise nsx_exc.NsxPluginException(err_msg=msg)

    def remove_router_interface(self, context, router_id, interface_info):
        # Get the router interface port id
        if self.fwaas_callbacks:
            port_id = interface_info.get('port_id')
            if not port_id:
                subnet_id = interface_info['subnet_id']
                subnet = self._get_subnet_object(context, subnet_id)
                rport_qry = context.session.query(models_v2.Port)
                ports = rport_qry.filter_by(
                    device_id=router_id,
                    device_owner=l3_db.DEVICE_OWNER_ROUTER_INTF,
                    network_id=subnet.network_id)
                for p in ports:
                    if p['fixed_ips'][0]['subnet_id'] == subnet_id:
                        port_id = p['id']
                        break

        router_driver = self._find_router_driver(context, router_id)
        result = router_driver.remove_router_interface(
            context, router_id, interface_info)
        # inform the FWaaS that interface port was removed
        if self.fwaas_callbacks and port_id:
            self.fwaas_callbacks.delete_port(context, port_id)
        return result

    def _get_floatingips_by_router(self, context, router_id):
        fip_qry = context.session.query(l3_db_models.FloatingIP)
        fip_db = fip_qry.filter_by(router_id=router_id).all()
        return [fip.floating_ip_address
                for fip in fip_db if fip.fixed_port_id]

    def _update_external_interface(self, context, router, router_id=None):
        ext_net_id = router.gw_port_id and router.gw_port.network_id
        addr, mask, nexthop = self._get_external_attachment_info(
            context, router)
        secondary = self._get_floatingips_by_router(context, router['id'])
        if not router_id:
            router_id = router['id']
        self.edge_manager.update_external_interface(
            self.nsx_v, context, router_id, ext_net_id,
            addr, mask, secondary)

    def _set_floatingip_status(self, context, floatingip_db, status=None):
        if not status:
            status = (constants.FLOATINGIP_STATUS_ACTIVE
                      if floatingip_db.get('router_id')
                      else constants.FLOATINGIP_STATUS_DOWN)
        if floatingip_db['status'] != status:
            floatingip_db['status'] = status
            self.update_floatingip_status(context, floatingip_db['id'], status)

    def _update_edge_router(self, context, router_id):
        router_driver = self._find_router_driver(context, router_id)
        router_driver._update_edge_router(context, router_id)

    def create_floatingip(self, context, floatingip):
        fip_db = super(NsxVPluginV2, self).create_floatingip(
            context, floatingip)
        router_id = fip_db['router_id']
        if router_id:
            try:
                self._update_edge_router(context, router_id)
            except Exception:
                with excutils.save_and_reraise_exception():
                    LOG.exception("Failed to update edge router")
                    super(NsxVPluginV2, self).delete_floatingip(context,
                                                                fip_db['id'])
        self._set_floatingip_status(context, fip_db)
        return fip_db

    def update_floatingip(self, context, id, floatingip):
        old_fip = self._get_floatingip(context, id)
        old_router_id = old_fip.router_id
        old_port_id = old_fip.fixed_port_id
        fip_db = super(NsxVPluginV2, self).update_floatingip(
            context, id, floatingip)
        router_id = fip_db.get('router_id')
        try:
            # Update old router's nat rules if old_router_id is not None.
            if old_router_id:
                self._update_edge_router(context, old_router_id)
            # Update current router's nat rules if router_id is not None.
            if router_id:
                self._update_edge_router(context, router_id)
        except Exception:
            with excutils.save_and_reraise_exception():
                LOG.exception("Failed to update edge router")
                super(NsxVPluginV2, self).update_floatingip(
                    context, id, {'floatingip': {'port_id': old_port_id}})
        self._set_floatingip_status(context, fip_db)
        return fip_db

    def delete_floatingip(self, context, id):
        fip_db = self._get_floatingip(context, id)
        router_id = None
        if fip_db.fixed_port_id:
            router_id = fip_db.router_id
        super(NsxVPluginV2, self).delete_floatingip(context, id)
        if router_id:
            self._update_edge_router(context, router_id)

    def disassociate_floatingips(self, context, port_id):
        router_id = None
        try:
            fip_qry = context.session.query(l3_db_models.FloatingIP)
            fip_db = fip_qry.filter_by(fixed_port_id=port_id)
            for fip in fip_db:
                if fip.router_id:
                    router_id = fip.router_id
                    break
        except sa_exc.NoResultFound:
            router_id = None
        super(NsxVPluginV2, self).disassociate_floatingips(context, port_id)
        if router_id:
            self._update_edge_router(context, router_id)

    def _update_subnets_and_dnat_firewall(self, context, router_db,
                                          router_id=None):
        """Update the router edge firewall with all the relevant rules.

        router_db is the neutron router structure
        router_id is the id of the actual router that will be updated on
        the NSX (in case of distributed router it can be plr or tlr)

        This is just a wrapper of update_router_firewall
        """
        if not router_id:
            router_id = router_db['id']

        self.update_router_firewall(context.elevated(), router_id, router_db)

    def _get_firewall_icmpv6_rules(self):
        # Add ipv6 icmp multicast rule (blocked in Vsphere 7 & up)
        application_ids = self.nsx_v.get_icmpv6_multicast_application_ids()
        rules = [{
            'name': 'IPV6-ICMP-multicast',
            'action': 'allow',
            'enabled': True,
            'application': {'applicationId': application_ids}}]
        return rules

    def update_router_firewall(self, context, router_id, router_db):
        """Recreate all rules in the router edge firewall

        router_db is the neutron router structure
        router_id is the id of the actual router that will be updated on
        the NSX (in case of distributed router it can be plr or tlr)
        """
        fw_rules = []
        distributed = False
        if router_db:
            nsx_attr = router_db.get('nsx_attributes', {})
            distributed = (
                nsx_attr.get('distributed', False) if nsx_attr else False)

        edge_id = self._get_edge_id_by_rtr_id(context, router_id)

        # Add FW rule/s to open subnets firewall flows and static routes
        # relative flows
        subnets = self._load_router_subnet_cidrs_from_db(context.elevated(),
                                                         router_id)
        subnet_rules = self._get_subnet_fw_rules(context, router_db,
                                                 subnets=subnets)
        if subnet_rules:
            fw_rules.extend(subnet_rules)

        # Add ipv6 icmp multicast rule (blocked in Vsphere 7 & up)
        fw_rules.extend(self._get_firewall_icmpv6_rules())

        # If metadata service is enabled, block access to inter-edge network
        if self.metadata_proxy_handler and not distributed:
            fw_rules += nsx_v_md_proxy.get_router_fw_rules()

        # Add FWaaS rules if FWaaS is enabled
        if (self.fwaas_callbacks and
            self.fwaas_callbacks.should_apply_firewall_to_router(
                context, router_db, router_id)):
            fwaas_rules = self.fwaas_callbacks.get_fwaas_rules_for_router(
                context, router_db['id'], router_db, edge_id)
            if fwaas_rules:
                fw_rules += fwaas_rules

        # The rules added from here forward are relevant only for interface
        # ports without fwaas firewall group
        # To allow this traffic on interfaces with firewall group, the user
        # should add specific rules.
        dnat_rule = self._get_dnat_fw_rule(context, router_db)
        if dnat_rule:
            fw_rules.append(dnat_rule)

        # Add rule for not NAT-ed allocation pools
        alloc_pool_rule = self._get_allocation_pools_fw_rule(
            context, router_db, subnets=subnets)
        if alloc_pool_rule:
            fw_rules.append(alloc_pool_rule)

        # Add no-snat rules
        nosnat_fw_rules = self._get_nosnat_subnets_fw_rules(
            context, router_db, subnets=subnets)
        fw_rules.extend(nosnat_fw_rules)

        vpn_plugin = directory.get_plugin(plugin_const.VPN)
        if vpn_plugin:
            vpn_driver = vpn_plugin.drivers[vpn_plugin.default_provider]
            vpn_rules = (
                vpn_driver._generate_ipsecvpn_firewall_rules(
                    self.plugin_type(), context, edge_id=edge_id))
            fw_rules.extend(vpn_rules)

        # Get the load balancer rules in case they are refreshed
        # (relevant only for older LB that are still on the router edge)
        lb_rules = nsxv_db.get_nsxv_lbaas_loadbalancer_binding_by_edge(
                context.session, edge_id)
        for rule in lb_rules:
            vsm_rule = None
            try:
                vsm_rule = self.nsx_v.vcns.get_firewall_rule(
                        edge_id, rule['edge_fw_rule_id'])[1]
            except vsh_exc.ResourceNotFound:
                LOG.error("LB firewall rule %s for edge %s exists in DB but "
                          "not in backend", rule['edge_fw_rule_id'], edge_id)
            if vsm_rule:
                lb_fw_rule = {
                    'action': edge_firewall_driver.FWAAS_ALLOW,
                    'enabled': vsm_rule['enabled'],
                    'destination_ip_address':
                        vsm_rule['destination']['ipAddress'],
                    'name': vsm_rule['name'],
                    'ruleId': vsm_rule['ruleId']
                }
                fw_rules.append(lb_fw_rule)

        fw = {'firewall_rule_list': fw_rules}
        try:
            edge_utils.update_firewall(self.nsx_v, context, router_id, fw)
        except vsh_exc.ResourceNotFound:
            LOG.error("Failed to update firewall for router %s",
                      router_id)

    def _delete_nsx_security_group(self, nsx_sg_id, nsx_policy):
        """Helper method to delete nsx security group."""
        if nsx_sg_id is not None:
            if nsx_policy:
                # First remove this security group from the NSX policy,
                # Or else the delete will fail
                try:
                    with locking.LockManager.get_lock(
                        'neutron-security-policy-' + str(nsx_policy)):
                        self.nsx_sg_utils.del_nsx_security_group_from_policy(
                            nsx_policy, nsx_sg_id)
                except Exception as e:
                    LOG.warning("Failed to remove nsx security group "
                                "%(id)s from policy %(pol)s : %(e)s",
                                {'id': nsx_sg_id, 'pol': nsx_policy, 'e': e})

            self.nsx_v.vcns.delete_security_group(nsx_sg_id)

    # Security group handling section #
    def _delete_section(self, section_uri):
        """Helper method to delete nsx rule section."""
        if section_uri is not None:
            self.nsx_v.vcns.delete_section(section_uri)

    def _get_section_uri(self, session, security_group_id):
        mapping = nsxv_db.get_nsx_section(session, security_group_id)
        if mapping is not None:
            return mapping['ip_section_id']

    def _create_fw_section_for_security_group(self,
                                              context,
                                              securitygroup,
                                              nsx_sg_id):
        logged = (cfg.CONF.nsxv.log_security_groups_allowed_traffic or
                  securitygroup[sg_logging.LOGGING])
        action = 'deny' if securitygroup[provider_sg.PROVIDER] else 'allow'
        section_name = self.nsx_sg_utils.get_nsx_section_name(securitygroup)
        nsx_rules = []
        # Translate Neutron rules to NSXv fw rules and construct the fw section
        for rule in securitygroup['security_group_rules']:
            nsx_rule = self._create_nsx_rule(
                context, rule, nsx_sg_id, logged=logged, action=action)
            nsx_rules.append(nsx_rule)
        section = self.nsx_sg_utils.get_section_with_rules(
            section_name, nsx_rules)
        # Execute REST API for creating the section
        h, c = self.nsx_v.vcns.create_section(
            'ip', self.nsx_sg_utils.to_xml_string(section),
            insert_top=securitygroup[provider_sg.PROVIDER],
            insert_before=self.default_section)

        rule_pairs = self.nsx_sg_utils.get_rule_id_pair_from_section(c)
        # Add database associations for fw section and rules
        nsxv_db.add_neutron_nsx_section_mapping(
            context.session, securitygroup['id'], h['location'])
        for pair in rule_pairs:
            # Save nsx rule id in the DB for future access
            nsxv_db.add_neutron_nsx_rule_mapping(
                context.session, pair['neutron_id'], pair['nsx_id'])

    def _create_nsx_security_group(self, context, securitygroup):
        nsx_sg_name = self.nsx_sg_utils.get_nsx_sg_name(securitygroup)
        # NSX security-group config
        sg_dict = {"securitygroup":
                   {"name": nsx_sg_name,
                    "description": securitygroup['description']}}
        # Create the nsx security group
        h, nsx_sg_id = self.nsx_v.vcns.create_security_group(sg_dict)

        # Save moref in the DB for future access
        nsx_db.add_neutron_nsx_security_group_mapping(
            context.session, securitygroup['id'], nsx_sg_id)
        return nsx_sg_id

    def _process_security_group_create_backend_resources(self,
                                                         context,
                                                         securitygroup):
        nsx_sg_id = self._create_nsx_security_group(context, securitygroup)
        policy = securitygroup.get(sg_policy.POLICY)
        if self._use_nsx_policies and policy:
            # When using policies - no rules should be created.
            # just add the security group to the policy on the backend.
            self._update_nsx_security_group_policies(
                policy, None, nsx_sg_id)
        else:
            try:
                self._create_fw_section_for_security_group(
                    context, securitygroup, nsx_sg_id)
            except Exception:
                with excutils.save_and_reraise_exception():
                    self._delete_nsx_security_group(nsx_sg_id, policy)

        if not securitygroup[provider_sg.PROVIDER]:
            # Add Security Group to the Security Groups container in order to
            # apply the default block rule.
            # This is relevant for policies security groups too.
            # provider security-groups should not have a default blocking rule.
            self._add_member_to_security_group(self.sg_container_id,
                                               nsx_sg_id)

    def _validate_security_group(self, context, security_group, default_sg,
                                 id=None):
        if self._use_nsx_policies:
            new_policy = None
            sg_with_policy = False
            if not id:
                # called from create_security_group
                # must have a policy:
                if not security_group.get(sg_policy.POLICY):
                    if default_sg:
                        # For default sg the default policy will be used
                        security_group[sg_policy.POLICY] = (
                            cfg.CONF.nsxv.default_policy_id)
                    elif not cfg.CONF.nsxv.allow_tenant_rules_with_policy:
                        if context.is_admin:
                            msg = _('A security group must be assigned to a '
                                    'policy')
                        else:
                            msg = _('Creation of security group is not '
                                    'allowed')
                        raise n_exc.InvalidInput(error_message=msg)

                new_policy = security_group.get(sg_policy.POLICY)
                sg_with_policy = bool(new_policy)
            else:
                # called from update_security_group.
                # Check if the existing security group has policy or not
                sg_with_policy = self._is_policy_security_group(context, id)
                if sg_policy.POLICY in security_group:
                    new_policy = security_group[sg_policy.POLICY]
                    if sg_with_policy and not new_policy:
                        # cannot remove a policy from an existing sg
                        msg = (_('Security group %s must be assigned to a '
                                'policy') % id)
                        raise n_exc.InvalidInput(error_message=msg)
                    if not sg_with_policy and new_policy:
                        # cannot add a policy to a non-policy security group
                        msg = (_('Cannot add policy to an existing security '
                                 'group %s') % id)
                        raise n_exc.InvalidInput(error_message=msg)

            # validate that the new policy exists (and not hidden) by using the
            # plugin getter that raises an exception if it fails.
            if new_policy:
                try:
                    policy_obj = self.get_nsx_policy(context, new_policy)
                except n_exc.ObjectNotFound:
                    msg = _('Policy %s was not found on the NSX') % new_policy
                    raise n_exc.InvalidInput(error_message=msg)

            # Do not support logging with policy
            if sg_with_policy and security_group.get(sg_logging.LOGGING):
                msg = _('Cannot support logging when using NSX policies')
                raise n_exc.InvalidInput(error_message=msg)

            # Use the NSX policy description as the description of this
            # security group if the description was not set by the user
            # and the security group is new or policy was updated
            # if the nsx policy has not description - use its name
            if new_policy and not security_group.get('description'):
                security_group['description'] = (
                    policy_obj.get('description') or
                    policy_obj.get('name'))[:db_const.DESCRIPTION_FIELD_SIZE]
        else:
            # must not have a policy:
            if security_group.get(sg_policy.POLICY):
                msg = _('The security group cannot be assigned to a policy')
                raise n_exc.InvalidInput(error_message=msg)

    def create_security_group(self, context, security_group, default_sg=False):
        """Create a security group."""
        sg_data = security_group['security_group']
        if not default_sg:
            self._ensure_default_security_group(context, sg_data['tenant_id'])

        sg_id = sg_data["id"] = str(uuidutils.generate_uuid())
        self._validate_security_group(context, sg_data, default_sg)

        with db_api.CONTEXT_WRITER.using(context):
            is_provider = bool(sg_data.get(provider_sg.PROVIDER))
            is_policy = bool(sg_data.get(sg_policy.POLICY))
            if is_provider or is_policy:
                new_sg = self.create_security_group_without_rules(
                    context, security_group, default_sg, is_provider)
            else:
                new_sg = super(NsxVPluginV2, self).create_security_group(
                    context, security_group, default_sg)
            self._process_security_group_properties_create(
                context, new_sg, sg_data, default_sg)
        try:
            self._process_security_group_create_backend_resources(
                context, new_sg)
        except Exception:
            # Couldn't create backend resources, rolling back neutron db
            # changes.
            with excutils.save_and_reraise_exception():
                # Delete security-group and its associations from database,
                # Only admin can delete the default security-group
                if default_sg:
                    context = context.elevated()
                super(NsxVPluginV2, self).delete_security_group(context, sg_id)
                LOG.exception('Failed to create security group')

        return new_sg

    def _update_security_group_with_policy(self, updated_group,
                                           sg_data, nsx_sg_id):
        """Handle security group update when using NSX policies

        Remove the security group from the old policies, and apply on the new
        policies
        """
        # Verify that the policy was not removed from the security group
        if (sg_policy.POLICY in updated_group and
            not updated_group[sg_policy.POLICY]):
            msg = _('It is not allowed to remove the policy from security '
                    'group %s') % nsx_sg_id
            raise n_exc.InvalidInput(error_message=msg)

        if (updated_group.get(sg_policy.POLICY) and
            updated_group[sg_policy.POLICY] != sg_data[sg_policy.POLICY]):

            new_policy = updated_group[sg_policy.POLICY]
            old_policy = sg_data[sg_policy.POLICY]

            self._update_nsx_security_group_policies(
                new_policy, old_policy, nsx_sg_id)

    def _update_nsx_security_group_policies(self, new_policy, old_policy,
                                            nsx_sg_id):
        # update the NSX security group to use this policy
        if old_policy:
            with locking.LockManager.get_lock(
                'neutron-security-policy-' + str(old_policy)):
                self.nsx_sg_utils.del_nsx_security_group_from_policy(
                    old_policy, nsx_sg_id)
        with locking.LockManager.get_lock(
            'neutron-security-policy-' + str(new_policy)):
            self.nsx_sg_utils.add_nsx_security_group_to_policy(
                new_policy, nsx_sg_id)

    def update_security_group(self, context, id, security_group):
        s = security_group['security_group']
        self._validate_security_group(context, s, False, id=id)
        self._prevent_non_admin_edit_provider_sg(context, id)
        nsx_sg_id = nsx_db.get_nsx_security_group_id(context.session, id,
                                                     moref=True)
        section_uri = self._get_section_uri(context.session, id)
        section_needs_update = False

        sg_data = super(NsxVPluginV2, self).update_security_group(
            context, id, security_group)

        # Reflect security-group name or description changes in the backend,
        if set(['name', 'description']) & set(s.keys()):
            nsx_sg_name = self.nsx_sg_utils.get_nsx_sg_name(sg_data)
            section_name = self.nsx_sg_utils.get_nsx_section_name(sg_data)
            self.nsx_v.vcns.update_security_group(
                nsx_sg_id, nsx_sg_name, sg_data['description'])

        # security groups with NSX policy - update the backend policy attached
        # to the security group
        if (self._use_nsx_policies and
            self._is_policy_security_group(context, id)):
            if sg_policy.POLICY in sg_data:
                self._update_security_group_with_policy(s, sg_data, nsx_sg_id)

            # The rest of the update are not relevant to policies security
            # groups as there is no matching section
            self._process_security_group_properties_update(
                context, sg_data, s)
            return sg_data

        with locking.LockManager.get_lock('rule-update-%s' % id):
            # Get the backend section matching this security group
            h, c = self.nsx_v.vcns.get_section(section_uri)
            section = self.nsx_sg_utils.parse_section(c)

            # dfw section name needs to be updated if the sg name was modified
            if 'name' in s.keys():
                section.attrib['name'] = section_name
                section_needs_update = True

            # Update the dfw section if security-group logging option has
            # changed.
            log_all_rules = cfg.CONF.nsxv.log_security_groups_allowed_traffic
            self._process_security_group_properties_update(context, sg_data, s)
            if not log_all_rules and context.is_admin:
                section_needs_update |= (
                    self.nsx_sg_utils.set_rules_logged_option(
                        section, sg_data[sg_logging.LOGGING]))

            if section_needs_update:
                # update the section with all the modifications
                self.nsx_v.vcns.update_section(
                    section_uri, self.nsx_sg_utils.to_xml_string(section), h)

        return sg_data

    def delete_security_group(self, context, id, delete_base=True):
        """Delete a security group."""
        self._prevent_non_admin_edit_provider_sg(context, id)
        self._prevent_non_admin_delete_policy_sg(context, id)
        policy = self._get_security_group_policy(context, id)
        try:
            # Find nsx rule sections
            section_uri = self._get_section_uri(context.session, id)

            # Find nsx security group
            nsx_sg_id = nsx_db.get_nsx_security_group_id(context.session, id,
                                                         moref=True)

            if delete_base:
                # Delete neutron security group
                super(NsxVPluginV2, self).delete_security_group(context, id)

            # Delete nsx rule sections
            self._delete_section(section_uri)

            # Delete nsx security group
            self._delete_nsx_security_group(nsx_sg_id, policy)

        except Exception:
            with excutils.save_and_reraise_exception():
                LOG.exception("Failed to delete security group")

    def _translate_nsx_protocols(self, protocol):
        # The NSX only excepts '58' as icmp-v6
        if (protocol == constants.PROTO_NAME_IPV6_ICMP or
            protocol == constants.PROTO_NAME_IPV6_ICMP_LEGACY):
            return str(constants.PROTO_NUM_IPV6_ICMP)

        # Some protocols are not supported and should be used as a number
        if protocol in UNSUPPORTED_RULE_NAMED_PROTOCOLS:
            return str(self._get_ip_proto_number(protocol))

        return protocol

    def _create_nsx_rule(self, context, rule,
                         nsx_sg_id=None, logged=False, action='allow'):
        src = None
        dest = None
        port = None
        protocol = None
        icmptype = None
        icmpcode = None
        flags = {}

        if nsx_sg_id is None:
            # Find nsx security group for neutron security group
            nsx_sg_id = nsx_db.get_nsx_security_group_id(
                context.session, rule['security_group_id'],
                moref=True)

        # Find the remote nsx security group id, which might be the current
        # one. In case of the default security-group, the associated
        # nsx-security-group wasn't written to the database yet.
        if rule['remote_group_id'] == rule['security_group_id']:
            remote_nsx_sg_id = nsx_sg_id
        else:
            remote_nsx_sg_id = nsx_db.get_nsx_security_group_id(
                context.session, rule['remote_group_id'], moref=True)

        # Get source and destination containers from rule
        if rule['direction'] == 'ingress':
            if rule.get(secgroup_rule_local_ip_prefix.LOCAL_IP_PREFIX):
                dest = self.nsx_sg_utils.get_remote_container(
                    None, rule[secgroup_rule_local_ip_prefix.LOCAL_IP_PREFIX])
            src = self.nsx_sg_utils.get_remote_container(
                remote_nsx_sg_id, rule['remote_ip_prefix'])
            dest = dest or self.nsx_sg_utils.get_container(nsx_sg_id)
            flags['direction'] = 'in'
        else:
            dest = self.nsx_sg_utils.get_remote_container(
                remote_nsx_sg_id, rule['remote_ip_prefix'])
            src = self.nsx_sg_utils.get_container(nsx_sg_id)
            flags['direction'] = 'out'

        protocol = self._translate_nsx_protocols(rule.get('protocol'))
        if rule['port_range_min'] is not None:
            if protocol == '1' or protocol == '58' or protocol == 'icmp':
                icmptype = str(rule['port_range_min'])
                if rule['port_range_max'] is not None:
                    icmpcode = str(rule['port_range_max'])
            else:
                port = str(rule['port_range_min'])
                if rule['port_range_max'] != rule['port_range_min']:
                    port = port + '-' + str(rule['port_range_max'])

        # Get the neutron rule id to use as name in nsxv rule
        name = rule.get('id')
        services = [(protocol, port, icmptype, icmpcode)] if protocol else []
        flags['ethertype'] = rule.get('ethertype')
        # Add rule in nsx rule section
        nsx_rule = self.nsx_sg_utils.get_rule_config(
            applied_to_ids=[nsx_sg_id],
            name=name,
            source=src,
            destination=dest,
            services=services,
            flags=flags,
            action=action,
            logged=logged,
            tag='Project_%s' % rule['tenant_id'],
            notes=rule.get('description'))
        return nsx_rule

    def create_security_group_rule(self, context, security_group_rule,
                                   create_base=True):
        """Create a single security group rule."""
        bulk_rule = {'security_group_rules': [security_group_rule]}
        return self.create_security_group_rule_bulk(
            context, bulk_rule, create_base=create_base)[0]

    def _validate_security_group_rules(self, context, rules):
        for rule in rules['security_group_rules']:
            r = rule.get('security_group_rule')

            # remote_address_group_id is not yet supported and might be missing
            if 'remote_address_group_id' not in r:
                r['remote_address_group_id'] = None

            port_based_proto = (self._get_ip_proto_number(r['protocol'])
                                in PROTOCOLS_SUPPORTING_PORTS)
            if (not port_based_proto and
                (r['port_range_min'] is not None or
                 r['port_range_max'] is not None)):
                msg = (_("Port values not valid for "
                         "protocol: %s") % r['protocol'])
                raise n_exc.BadRequest(resource='security_group_rule',
                                       msg=msg)
        return super(NsxVPluginV2, self)._validate_security_group_rules(
            context, rules)

    def create_security_group_rule_bulk(self, context, security_group_rules,
                                        create_base=True):
        """Create security group rules.

        :param security_group_rules: list of rules to create
        """
        sg_rules = security_group_rules['security_group_rules']
        sg_id = sg_rules[0]['security_group_rule']['security_group_id']

        self._prevent_non_admin_edit_provider_sg(context, sg_id)

        ruleids = set()
        nsx_rules = []

        self._validate_security_group_rules(context, security_group_rules)

        if self._is_policy_security_group(context, sg_id):
            # If policies are/were enabled - creating rules is forbidden
            msg = (_('Cannot create rules for security group %s with'
                     ' a policy') % sg_id)
            raise n_exc.InvalidInput(error_message=msg)

        with locking.LockManager.get_lock('rule-update-%s' % sg_id):
            # Querying DB for associated dfw section id
            section_uri = self._get_section_uri(context.session, sg_id)
            if not section_uri:
                error = "NSX mapping for security group %s not found" % sg_id
                raise nsx_exc.NsxPluginException(err_msg=error)
            logged = self._is_security_group_logged(context, sg_id)
            provider = self._is_provider_security_group(context, sg_id)
            log_all_rules = cfg.CONF.nsxv.log_security_groups_allowed_traffic

            # Translating Neutron rules to Nsx DFW rules
            for r in sg_rules:
                rule = r['security_group_rule']
                if not self._check_local_ip_prefix(context, rule):
                    rule[secgroup_rule_local_ip_prefix.LOCAL_IP_PREFIX] = None
                self._fix_sg_rule_dict_ips(rule)
                rule['id'] = rule.get('id') or uuidutils.generate_uuid()
                ruleids.add(rule['id'])
                nsx_rules.append(
                    self._create_nsx_rule(context, rule,
                                        logged=log_all_rules or logged,
                                        action='deny' if provider else 'allow')
                )

            _h, _c = self.nsx_v.vcns.get_section(section_uri)
            section = self.nsx_sg_utils.parse_section(_c)
            self.nsx_sg_utils.fix_existing_section_rules(section)
            self.nsx_sg_utils.extend_section_with_rules(section, nsx_rules)
            try:
                h, c = self.nsx_v.vcns.update_section(
                    section_uri, self.nsx_sg_utils.to_xml_string(section), _h)
            except vsh_exc.RequestBad as e:
                # Raise the original reason of the failure
                details = et.fromstring(e.response).find('details')
                raise n_exc.BadRequest(
                    resource='security_group_rule',
                    msg=details.text if details is not None else "Unknown")

            rule_pairs = self.nsx_sg_utils.get_rule_id_pair_from_section(c)

        try:
            # Save new rules in Database, including mappings between Nsx rules
            # and Neutron security-groups rules
            with db_api.CONTEXT_WRITER.using(context):
                if create_base:
                    new_rule_list = super(
                        NsxVPluginV2,
                        self).create_security_group_rule_bulk_native(
                            context, security_group_rules)
                    for i, r in enumerate(sg_rules):
                        self._process_security_group_rule_properties(
                            context, new_rule_list[i],
                            r['security_group_rule'])
                else:
                    new_rule_list = sg_rules
                for pair in rule_pairs:
                    neutron_rule_id = pair['neutron_id']
                    nsx_rule_id = pair['nsx_id']
                    if neutron_rule_id in ruleids:
                        nsxv_db.add_neutron_nsx_rule_mapping(
                            context.session, neutron_rule_id, nsx_rule_id)
        except Exception:
            with excutils.save_and_reraise_exception():
                for nsx_rule_id in [p['nsx_id'] for p in rule_pairs
                                    if p['neutron_id'] in ruleids]:
                    with locking.LockManager.get_lock('rule-update-%s' %
                                                      sg_id):
                        self.nsx_v.vcns.remove_rule_from_section(
                            section_uri, nsx_rule_id)
                LOG.exception("Failed to create security group rule")
        return new_rule_list

    def delete_security_group_rule(self, context, id, delete_base=True):
        """Delete a security group rule."""
        rule_db = self._get_security_group_rule(context, id)
        security_group_id = rule_db['security_group_id']
        self._prevent_non_admin_edit_provider_sg(context, security_group_id)

        # Get the nsx rule from neutron DB and delete it
        nsx_rule_id = nsxv_db.get_nsx_rule_id(context.session, id)
        section_uri = self._get_section_uri(
            context.session, security_group_id)
        try:
            if nsx_rule_id and section_uri:
                with locking.LockManager.get_lock('rule-update-%s' %
                                                  security_group_id):
                    self.nsx_v.vcns.remove_rule_from_section(
                        section_uri, nsx_rule_id)
        except vsh_exc.ResourceNotFound:
            LOG.debug("Security group rule %(id)s deleted, backend "
                      "nsx-rule %(nsx_rule_id)s doesn't exist.",
                      {'id': id, 'nsx_rule_id': nsx_rule_id})
        if delete_base:
            obj_reg.load_class('SecurityGroupRule').delete_objects(
                context, id=id)

    def _remove_vnic_from_spoofguard_policy(self, session, net_id, vnic_id):
        policy_id = nsxv_db.get_spoofguard_policy_id(session, net_id)
        self.nsx_v.vcns.inactivate_vnic_assigned_addresses(policy_id, vnic_id)

    def _update_vnic_assigned_addresses(self, session, port, vnic_id):
        sg_policy_id = nsxv_db.get_spoofguard_policy_id(
            session, port['network_id'])
        if not sg_policy_id:
            LOG.warning("Spoofguard not defined for network %s",
                        port['network_id'])
            return
        mac_addr = port['mac_address']
        approved_addrs = [addr['ip_address'] for addr in port['fixed_ips']]
        # add in the address pair
        approved_addrs.extend(
            addr['ip_address'] for addr in port[addr_apidef.ADDRESS_PAIRS])
        # add the IPv6 link-local address if there is an IPv6 address
        if any([netaddr.valid_ipv6(address) for address in approved_addrs]):
            lla = str(netutils.get_ipv6_addr_by_EUI64(
                      constants.IPv6_LLA_PREFIX, mac_addr))
            approved_addrs.append(lla)
        try:
            self.nsx_v.vcns.approve_assigned_addresses(
                sg_policy_id, vnic_id, mac_addr, approved_addrs)
        except vsh_exc.AlreadyExists:
            # Entry already configured on the NSX
            pass
        try:
            self.nsx_v.vcns.publish_assigned_addresses(sg_policy_id, vnic_id)
        except Exception as e:
            LOG.warning("Failed to publish entry for port %(port)s "
                        "for vnic %(vnic)s: %(exc)s",
                        {'port': port['id'], 'vnic': vnic_id, 'exc': str(e)})

    def _is_compute_port(self, port):
        try:
            if (port['device_id'] and
                uuidutils.is_uuid_like(port['device_id']) and
                port['device_owner'].startswith('compute:')):
                return True
        except (KeyError, AttributeError):
            pass
        return False

    def _is_valid_ip(self, ip_addr):
        return netaddr.valid_ipv4(ip_addr) or netaddr.valid_ipv6(ip_addr)

    def _ensure_lock_operations(self):
        try:
            self.nsx_v.vcns.edges_lock_operation()
        except Exception:
            LOG.info("Unable to set manager lock operation")

    def _aggregate_publishing(self):
        try:
            self.nsx_v.vcns.configure_aggregate_publishing()
        except Exception:
            LOG.info("Unable to configure aggregate publishing")

    def _configure_reservations(self):
        ver = self.nsx_v.vcns.get_version()
        if version.LooseVersion(ver) < version.LooseVersion('6.2.3'):
            LOG.debug("Skipping reservation configuration. "
                      "Not supported by version - %s.", ver)
            return
        try:
            self.nsx_v.vcns.configure_reservations()
        except Exception:
            LOG.info("Unable to configure edge reservations")

    def _validate_config(self):
        self.existing_dvs = self.nsx_v.vcns.get_dvs_list()
        if (cfg.CONF.nsxv.dvs_id and
            not self.nsx_v.vcns.validate_dvs(cfg.CONF.nsxv.dvs_id,
                                             dvs_list=self.existing_dvs)):
            raise nsx_exc.NsxResourceNotFound(
                                res_name='dvs_id',
                                res_id=cfg.CONF.nsxv.dvs_id)
        for dvs_id in self._availability_zones_data.get_additional_dvs_ids():
            if not self.nsx_v.vcns.validate_dvs(dvs_id,
                                                dvs_list=self.existing_dvs):
                raise nsx_exc.NsxAZResourceNotFound(
                    res_name='dvs_id', res_id=dvs_id)

        # validate network-vlan dvs ID's
        for dvs_id in self._network_vlans:
            if not self.nsx_v.vcns.validate_dvs(dvs_id,
                                                dvs_list=self.existing_dvs):
                raise nsx_exc.NsxResourceNotFound(res_name='dvs_id',
                                                  res_id=dvs_id)

        # Validate the global & per-AZ validate_datacenter_moid
        if not self.nsx_v.vcns.validate_datacenter_moid(
                cfg.CONF.nsxv.datacenter_moid,
                during_init=True):
            raise nsx_exc.NsxResourceNotFound(
                                res_name='datacenter_moid',
                                res_id=cfg.CONF.nsxv.datacenter_moid)
        for dc in self._availability_zones_data.get_additional_datacenter():
            if not self.nsx_v.vcns.validate_datacenter_moid(
                dc, during_init=True):
                raise nsx_exc.NsxAZResourceNotFound(
                    res_name='datacenter_moid', res_id=dc)

        # Validate the global & per-AZ external_network
        if not self.nsx_v.vcns.validate_network(
                cfg.CONF.nsxv.external_network,
                during_init=True):
            raise nsx_exc.NsxResourceNotFound(
                                res_name='external_network',
                                res_id=cfg.CONF.nsxv.external_network)
        for ext_net in self._availability_zones_data.get_additional_ext_net():
            if not self.nsx_v.vcns.validate_network(
                ext_net, during_init=True):
                raise nsx_exc.NsxAZResourceNotFound(
                    res_name='external_network', res_id=ext_net)

        # Validate the global & per-AZ vdn_scope_id
        if not self.nsx_v.vcns.validate_vdn_scope(cfg.CONF.nsxv.vdn_scope_id):
            raise nsx_exc.NsxResourceNotFound(
                                res_name='vdn_scope_id',
                                res_id=cfg.CONF.nsxv.vdn_scope_id)
        for vdns in self._availability_zones_data.get_additional_vdn_scope():
            if not self.nsx_v.vcns.validate_vdn_scope(vdns):
                raise nsx_exc.NsxAZResourceNotFound(
                    res_name='vdn_scope_id', res_id=vdns)

        # Validate the global & per-AZ mgt_net_moid
        if (cfg.CONF.nsxv.mgt_net_moid and
            not self.nsx_v.vcns.validate_network(
                cfg.CONF.nsxv.mgt_net_moid)):
            raise nsx_exc.NsxResourceNotFound(
                                res_name='mgt_net_moid',
                                res_id=cfg.CONF.nsxv.mgt_net_moid)
        for mgmt_net in self._availability_zones_data.get_additional_mgt_net():
            if not self.nsx_v.vcns.validate_network(mgmt_net):
                raise nsx_exc.NsxAZResourceNotFound(
                    res_name='mgt_net_moid', res_id=mgmt_net)

        ver = self.nsx_v.vcns.get_version()
        if version.LooseVersion(ver) < version.LooseVersion('6.2.0'):
            LOG.warning("Skipping validations. Not supported by version.")
            return

        # Validate the host_groups for each AZ
        if cfg.CONF.nsxv.use_dvs_features:
            azs = self.get_azs_list()
            for az in azs:
                if az.edge_host_groups and az.edge_ha:
                    if len(az.edge_host_groups) < 2:
                        error = _("edge_host_groups must have at least 2 "
                                  "names")
                        raise nsx_exc.NsxPluginException(err_msg=error)
                    if (not az.ha_placement_random and
                        len(az.edge_host_groups) > 2):
                        LOG.warning("Availability zone %(az)s has %(count)s "
                                    "hostgroups. only the first 2 will be "
                                    "used until ha_placement_random is "
                                    "enabled",
                                    {'az': az.name,
                                     'count': len(az.edge_host_groups)})
                    self._vcm.validate_host_groups(az.resource_pool,
                                                   az.edge_host_groups)

        # Validations below only supported by 6.2.0 and above
        inventory = [(cfg.CONF.nsxv.resource_pool_id,
                      'resource_pool_id'),
                     (cfg.CONF.nsxv.datastore_id,
                      'datastore_id'),
                     (cfg.CONF.nsxv.ha_datastore_id,
                      'ha_datastore_id'),
                     ]
        # Treat the cluster list
        for cluster in cfg.CONF.nsxv.cluster_moid:
            inventory.append((cluster, 'cluster_moid'))

        # Add the availability zones resources
        az_resources = self._availability_zones_data.get_inventory()
        for res in az_resources:
            inventory.append((res, 'availability_zone ' + res))

        if cfg.CONF.nsxv.use_nsx_policies:
            # if use_nsx_policies=True, the default policy must be defined
            if not cfg.CONF.nsxv.default_policy_id:
                error = _("default_policy_id must be defined")
                raise nsx_exc.NsxPluginException(err_msg=error)
            inventory.append((cfg.CONF.nsxv.default_policy_id,
                              'default_policy_id'))

        for moref, field in inventory:
            if moref and not self.nsx_v.vcns.validate_inventory(moref):
                error = _("Configured %s not found") % field
                raise nsx_exc.NsxPluginException(err_msg=error)

        if cfg.CONF.nsxv.vdr_transit_network:
            edge_utils.validate_vdr_transit_network()

        # Validate configuration connectivity per AZ
        self._availability_zones_data.validate_connectivity(
            self.nsx_v.vcns)

    def _nsx_policy_is_hidden(self, policy):
        for attrib in policy.get('extendedAttributes', []):
            if (attrib['name'].lower() == 'ishidden' and
                attrib['value'].lower() == 'true'):
                return True
        return False

    def _nsx_policy_to_dict(self, policy):
        return {'id': policy['objectId'],
                'name': policy.get('name'),
                'description': policy.get('description')}

    def get_nsx_policy(self, context, id, fields=None):
        try:
            policy = self.nsx_v.vcns.get_security_policy(id, return_xml=False)
        except vsh_exc.ResourceNotFound:
            # no such policy on backend
            raise n_exc.ObjectNotFound(id=id)
        if self._nsx_policy_is_hidden(policy):
            # This is an hidden policy
            raise n_exc.ObjectNotFound(id=id)
        return self._nsx_policy_to_dict(policy)

    def get_nsx_policies(self, context, filters=None, fields=None,
                         sorts=None, limit=None, marker=None,
                         page_reverse=False):
        policies = self.nsx_v.vcns.get_security_policies()
        results = []
        for policy in policies.get('policies', []):
            if not self._nsx_policy_is_hidden(policy):
                results.append(self._nsx_policy_to_dict(policy))
        return results

    def _get_appservice_id(self, name):
        return self.nsx_v.vcns.get_application_id(name)

    def service_router_has_loadbalancers(self, context, router_id):
        # This api is used by Octavia to verify that a router can be deleted
        # Currently the V plugin does not support this
        return False
