def get_networks(self, context, filters=None, fields=None,
                     sorts=None, limit=None, marker=None, page_reverse=False):
        # if id is not specified in the filter, we just return network data in
        # local Neutron server, otherwise id is specified, we need to retrieve
        # network data from central Neutron server and create network which
        # doesn't exist in local Neutron server.
        if not filters or 'id' not in filters:
            return self.core_plugin.get_networks(
                context, filters, fields, sorts, limit, marker, page_reverse)

        b_full_networks = self.core_plugin.get_networks(
            context, filters, None, sorts, limit, marker, page_reverse)
        b_networks = []
        for b_network in b_full_networks:
            subnet_ids = self._ensure_subnet(context, b_network, False)
            if subnet_ids:
                b_network['subnets'] = subnet_ids
            b_networks.append(db_utils.resource_fields(b_network, fields))

        if len(b_networks) == len(filters['id']):
            return b_networks

        t_ctx = t_context.get_context_from_neutron_context(context)
        if self._skip_non_api_query(t_ctx):
            return b_networks
        t_ctx.auth_token = client.Client.get_admin_token(context.project_id)
        raw_client = self.neutron_handle._get_client(t_ctx)
        params = self._construct_params(filters, sorts, limit, marker,
                                        page_reverse)
        t_networks = raw_client.list_networks(**params)['networks']

        t_id_set = set([network['id'] for network in t_networks])
        b_id_set = set([network['id'] for network in b_networks])
        missing_id_set = t_id_set - b_id_set
        if missing_id_set:
            missing_networks = [network for network in t_networks if (
                network['id'] in missing_id_set)]
            for network in missing_networks:
                region_name = self._get_neutron_region()
                located = self._is_network_located_in_region(network,
                                                             region_name)
                if not located:
                    LOG.error('network: %(net_id)s not located in current '
                              'region: %(region_name)s, '
                              'az_hints: %(az_hints)s',
                              {'net_id': network['id'],
                               'region_name': region_name,
                               'az_hints': network[az_def.AZ_HINTS]})
                    continue

                self._adapt_network_body(network)

                network.pop('qos_policy_id', None)
                b_network = self.core_plugin.create_network(
                    context, {'network': network})
                subnet_ids = self._ensure_subnet(context, network)
                if subnet_ids:
                    b_network['subnets'] = subnet_ids
                b_networks.append(db_utils.resource_fields(b_network, fields))
        return b_networks

 def delete_flow_classifier_precommit(self, context):
     t_ctx = t_context.get_context_from_neutron_context(
         context._plugin_context)
     flowclassifier_id = context.current['id']
     db_api.create_recycle_resource(
         t_ctx, flowclassifier_id, t_constants.RT_FLOW_CLASSIFIER,
         t_ctx.project_id)

    def delete_security_group_rule(self, q_context, _id):
        rule = self.get_security_group_rule(q_context, _id)
        if rule['remote_group_id']:
            raise n_exceptions.RemoteGroupNotSupported()
        sg_id = rule['security_group_id']
        sg = self.get_security_group(q_context, sg_id)
        if sg['name'] == 'default':
            raise n_exceptions.DefaultGroupUpdateNotSupported()

        t_context = context.get_context_from_neutron_context(q_context)
        mappings = db_api.get_bottom_mappings_by_top_id(
            t_context, sg_id, constants.RT_SG)

        try:
            for pod, b_sg_id in mappings:
                client = self._get_client(pod['pod_name'])
                rule['security_group_id'] = b_sg_id
                b_sg = client.get_security_groups(t_context, b_sg_id)
                for b_rule in b_sg['security_group_rules']:
                    if not self._compare_rule(b_rule, rule):
                        continue
                    self._safe_delete_security_group_rule(t_context, client,
                                                          b_rule['id'])
                    break
        except Exception:
            raise n_exceptions.BottomPodOperationFailure(
                resource='security group rule', pod_name=pod['pod_name'])

        super(TricircleSecurityGroupMixin,
              self).delete_security_group_rule(q_context, _id)

    def update_port(self, context, _id, port):
        # ovs agent will not call update_port, it updates port status via rpc
        # and direct db operation
        profile_dict = port['port'].get(portbindings.PROFILE, {})
        if profile_dict.pop(t_constants.PROFILE_FORCE_UP, None):
            port['port']['status'] = q_constants.PORT_STATUS_ACTIVE
            port['port'][
                portbindings.VNIC_TYPE] = q_constants.ATTR_NOT_SPECIFIED
        b_port = self.core_plugin.update_port(context, _id, port)
        if self._need_top_update(b_port, port['port']):
            region_name = self._get_neutron_region()
            update_dict = {portbindings.PROFILE: {
                t_constants.PROFILE_REGION: region_name,
                t_constants.PROFILE_DEVICE: b_port['device_owner']}}
            self._fill_agent_info_in_profile(
                context, _id, port['port'][portbindings.HOST_ID],
                update_dict[portbindings.PROFILE])

            if directory.get_plugin('trunk'):
                trunk_details = b_port.get('trunk_details')
                if trunk_details:
                    update_dict['binding:profile'].update({
                        t_constants.PROFILE_LOCAL_TRUNK_ID:
                            trunk_details['trunk_id']})

            t_ctx = t_context.get_context_from_neutron_context(context)
            self.neutron_handle.handle_update(t_ctx, 'port', _id,
                                              {'port': update_dict})
        return b_port

 def delete_port_pair_precommit(self, context):
     t_ctx = t_context.get_context_from_neutron_context(
         context._plugin_context)
     portpair_id = context.current['id']
     db_api.create_recycle_resource(
         t_ctx, portpair_id, t_constants.RT_PORT_PAIR,
         t_ctx.project_id)

    def update_subnet(self, context, _id, subnet):
        """update bottom subnet

        Can not directly use ML2 plugin's update_subnet function,
        because it will call local plugin's get_subnet in a transaction,
        the local plugin's get_subnet will create a dhcp port when subnet's
        enable_dhcp attribute is changed from False to True, but neutron
        doesn't allow calling create_port in a transaction and will raise an
        exception.

        :param context: neutron context
        :param _id: subnet_id
        :param subnet: update body
        :return: updated subnet
        """
        t_ctx = t_context.get_context_from_neutron_context(context)
        b_subnet = self.core_plugin.get_subnet(context, _id)
        origin_enable_dhcp = b_subnet['enable_dhcp']
        req_enable_dhcp = subnet['subnet'].get('enable_dhcp')
        # when request enable dhcp, and origin dhcp is disabled,
        # ensure subnet dhcp port is created
        if req_enable_dhcp and not origin_enable_dhcp:
            self._ensure_subnet_dhcp_port(t_ctx, context, b_subnet)
        res = self.core_plugin.update_subnet(context, _id, subnet)
        return res

    def create_security_group_rule(self, q_context, security_group_rule):
        rule = security_group_rule['security_group_rule']
        if rule['remote_group_id']:
            raise n_exceptions.RemoteGroupNotSupported()
        sg_id = rule['security_group_id']
        sg = self.get_security_group(q_context, sg_id)
        if sg['name'] == 'default':
            raise n_exceptions.DefaultGroupUpdateNotSupported()

        new_rule = super(TricircleSecurityGroupMixin,
                         self).create_security_group_rule(q_context,
                                                          security_group_rule)

        t_context = context.get_context_from_neutron_context(q_context)
        mappings = db_api.get_bottom_mappings_by_top_id(
            t_context, sg_id, constants.RT_SG)

        try:
            for pod, b_sg_id in mappings:
                client = self._get_client(pod['pod_name'])
                rule['security_group_id'] = b_sg_id
                self._safe_create_security_group_rule(
                    t_context, client, {'security_group_rule': rule})
        except Exception:
            super(TricircleSecurityGroupMixin,
                  self).delete_security_group_rule(q_context, new_rule['id'])
            raise n_exceptions.BottomPodOperationFailure(
                resource='security group rule', pod_name=pod['pod_name'])
        return new_rule

 def update_port_pair_group_precommit(self, context):
     plugin_context = context._plugin_context
     t_ctx = t_context.get_context_from_neutron_context(
         context._plugin_context)
     port_pair_group = context.current
     mappings = db_api.get_bottom_mappings_by_top_id(
         t_ctx, port_pair_group['id'], t_constants.RT_PORT_PAIR_GROUP)
     if mappings:
         portchain_id = self._get_chain_id_by_group_id(
             plugin_context, context._plugin, port_pair_group['id'])
         if port_pair_group['port_pairs']:
             net_id = self._get_net_id_by_portpairgroups(
                 plugin_context, context._plugin, [port_pair_group['id']])
         elif context.original['port_pairs']:
             portpair_id = context.original['port_pairs'][0]
             port_pair = context._plugin._get_port_pair(
                 plugin_context, portpair_id)
             net_id = self._get_net_id_by_port_id(
                 plugin_context, port_pair['ingress'])
         else:
             net_id = ''
         if not portchain_id and not net_id:
             return
         self.xjob_handler.sync_service_function_chain(
             t_ctx, port_pair_group['project_id'], portchain_id, net_id,
             t_constants.POD_NOT_SPECIFIED)

 def prepare_bottom_external_subnet_by_bottom_name(
         self, context, subnet, region_name, b_net_name, top_subnet_id):
     t_ctx = t_context.get_context_from_neutron_context(context)
     pod = db_api.get_pod_by_name(t_ctx, region_name)
     b_client = self._get_client(region_name)
     bottom_network = b_client.list_networks(
         t_ctx, [{'key': 'name',
                  'comparator': 'eq',
                  'value': b_net_name}]
     )
     if not bottom_network:
         raise t_exceptions.InvalidInput(
             reason='bottom network not found for %(b_net_name)s'
                    % {'b_net_name': b_net_name})
     body = {
         'subnet': {
             'name': top_subnet_id,
             'network_id': bottom_network[0]['id'],
             'tenant_id': subnet['tenant_id']
         }
     }
     attrs = ('ip_version', 'cidr', 'gateway_ip', 'allocation_pools',
              'enable_dhcp')
     for attr in attrs:
         if validators.is_attr_set(subnet.get(attr)):
             body['subnet'][attr] = subnet[attr]
     self.prepare_bottom_element(
         t_ctx, subnet['tenant_id'], pod, {'id': top_subnet_id},
         t_constants.RT_SUBNET, body)

    def create_port(self, context, port):
        port_body = port['port']
        network_id = port_body['network_id']
        # get_network will create bottom network if it doesn't exist
        self.get_network(context, network_id)

        t_ctx = t_context.get_context_from_neutron_context(context)
        raw_client = self.neutron_handle._get_client(t_ctx)

        def get_top_port_by_ip(ip):
            params = {'fixed_ips': 'ip_address=%s' % ip,
                      'network_id': network_id}
            t_ports = raw_client.list_ports(**params)['ports']
            if not t_ports:
                raise q_exceptions.InvalidIpForNetwork(
                    ip_address=fixed_ip['ip_address'])
            return t_ports[0]

        if port_body['fixed_ips'] is not q_constants.ATTR_NOT_SPECIFIED and (
            port_body.get('device_owner') != (
                q_constants.DEVICE_OWNER_LOADBALANCERV2)):
            if not self._is_special_port(port_body):
                fixed_ip = port_body['fixed_ips'][0]
                ip_address = fixed_ip.get('ip_address')
                if not ip_address:
                    # dhcp agent may request to create a dhcp port without
                    # specifying ip address, we just raise an exception to
                    # reject this request
                    raise q_exceptions.InvalidIpForNetwork(ip_address='None')
                t_port = get_top_port_by_ip(ip_address)
            elif helper.NetworkHelper.is_need_top_sync_port(
                    port_body, cfg.CONF.client.bridge_cidr):
                # for port that needs to be synced with top port, we keep ids
                # the same
                ip_address = port_body['fixed_ips'][0]['ip_address']
                port_body['id'] = get_top_port_by_ip(ip_address)['id']
                t_port = port_body
            else:
                self._handle_dvr_snat_port(t_ctx, port_body)
                t_port = port_body
        else:
            self._adapt_port_body_for_client(port['port'])
            t_port = raw_client.create_port(port)['port']

        if not self._is_special_port(port_body):
            subnet_id = t_port['fixed_ips'][0]['subnet_id']
            # get_subnet will create bottom subnet if it doesn't exist
            self.get_subnet(context, subnet_id)

        for field in ('name', 'device_id', 'device_owner', 'binding:host_id'):
            if port_body.get(field):
                t_port[field] = port_body[field]

        self._handle_security_group(t_ctx, context, t_port)
        self._create_shadow_agent(context, port_body)

        t_port.pop('qos_policy_id', None)
        b_port = self.core_plugin.create_port(context, {'port': t_port})
        return b_port

    def get_trunks(self, context, filters=None, fields=None,
                   sorts=None, limit=None, marker=None, page_reverse=False):
        ret = []
        bottom_top_map = {}
        top_bottom_map = {}
        t_ctx = t_context.get_context_from_neutron_context(context)

        route_filters = [{'key': 'resource_type',
                          'comparator': 'eq',
                          'value': t_constants.RT_TRUNK}]
        routes = db_api.list_resource_routings(t_ctx, route_filters)
        for route in routes:
            bottom_top_map[route['bottom_id']] = route['top_id']
            top_bottom_map[route['top_id']] = route['bottom_id']

        if limit:
            if marker:
                mappings = db_api.get_bottom_mappings_by_top_id(
                    t_ctx, marker, t_constants.RT_TRUNK)
                # if mapping exists, we retrieve trunk information
                # from bottom, otherwise from top
                if mappings:
                    pod_id = mappings[0][0]['pod_id']
                    current_pod = db_api.get_pod(t_ctx, pod_id)
                    ret = self._get_trunks_from_pod_with_limit(
                        context, current_pod, bottom_top_map, top_bottom_map,
                        filters, limit, marker)
                else:
                    ret = self._get_trunks_from_top_with_limit(
                        context, top_bottom_map, filters, limit, marker)
            else:
                current_pod = db_api.get_next_bottom_pod(t_ctx)
                # if current_pod exists, we retrieve trunk information
                # from bottom, otherwise from top
                if current_pod:
                    ret = self._get_trunks_from_pod_with_limit(
                        context, current_pod, bottom_top_map, top_bottom_map,
                        filters, limit, None)
                else:
                    ret = self._get_trunks_from_top_with_limit(
                        context, top_bottom_map, filters, limit, None)
        else:
            pods = db_api.list_pods(t_ctx)
            _filters = self._transform_trunk_filters(filters, top_bottom_map)
            for pod in pods:
                if not pod['az_name']:
                    continue
                client = self._get_client(pod['region_name'])
                pod_trunks = client.list_trunks(t_ctx, filters=_filters)
                ret.extend(pod_trunks)
            ret = self._map_trunks_from_bottom_to_top(ret, bottom_top_map)
            top_trunks = self._get_trunks_from_top(context,
                                                   top_bottom_map, filters)
            ret.extend(top_trunks)

        return [super(TricircleTrunkPlugin, self)._fields(trunk, fields)
                for trunk in ret]

 def remove_bottom_router_by_name(self, n_context, region_name,
                                  router_name):
     t_ctx = t_context.get_context_from_neutron_context(n_context)
     b_client = self._get_client(region_name)
     bottom_router = b_client.list_routers(
         t_ctx, [{'key': 'name',
                  'comparator': 'eq',
                  'value': router_name}])
     if bottom_router:
         b_client.delete_routers(t_ctx, bottom_router[0]['id'])

 def create_port_chain_precommit(self, context):
     plugin_context = context._plugin_context
     t_ctx = t_context.get_context_from_neutron_context(plugin_context)
     port_chain = context.current
     net_id = self._get_net_id_by_portpairgroups(
         plugin_context, context._plugin, port_chain['port_pair_groups'])
     if net_id:
         self.xjob_handler.sync_service_function_chain(
             t_ctx, port_chain['project_id'], port_chain['id'], net_id,
             t_constants.POD_NOT_SPECIFIED)

 def remove_bottom_external_network_by_name(
         self, n_context, region_name, name):
     t_ctx = t_context.get_context_from_neutron_context(n_context)
     b_client = self._get_client(region_name)
     b_net = b_client.list_networks(
         t_ctx, [{'key': 'name',
                  'comparator': 'eq',
                  'value': name}])
     if b_net:
         b_client.delete_networks(t_ctx, b_net[0]['id'])

 def _create_bottom_network(self, context, _id):
     t_ctx = t_context.get_context_from_neutron_context(context)
     t_network = self.neutron_handle.handle_get(t_ctx, 'network', _id)
     if not t_network:
         raise q_exceptions.NetworkNotFound(net_id=_id)
     self._adapt_network_body(t_network)
     t_network.pop('qos_policy_id', None)
     b_network = self.core_plugin.create_network(context,
                                                 {'network': t_network})
     return t_network, b_network

 def delete_trunk(self, context, trunk_id):
     t_ctx = t_context.get_context_from_neutron_context(context)
     res = super(TricircleTrunkPlugin, self).get_trunk(context, trunk_id)
     with context.session.begin():
         super(TricircleTrunkPlugin, self).delete_trunk(context, trunk_id)
         mappings = db_api.get_bottom_mappings_by_top_id(
             t_ctx, trunk_id, t_constants.RT_TRUNK)
         if mappings:
             b_pod = mappings[0][0]
             self.xjob_handler.sync_trunk(t_ctx, res['project_id'],
                                          trunk_id, b_pod['pod_id'])

 def update_trunk(self, context, trunk_id, trunk):
     # update trunk
     t_ctx = t_context.get_context_from_neutron_context(context)
     with context.session.begin():
         res = super(TricircleTrunkDriver, self).update_trunk(
             context, trunk_id, trunk)
         mappings = db_api.get_bottom_mappings_by_top_id(
             t_ctx, trunk_id, t_constants.RT_TRUNK)
         if mappings:
             b_pod = mappings[0][0]
             self.xjob_handler.sync_trunk(t_ctx, res['project_id'],
                                          trunk_id, b_pod['pod_id'])
     return res

    def remove_subports(self, context, trunk_id, subports):
        t_ctx = t_context.get_context_from_neutron_context(context)
        with context.session.begin():
            self.update_subports_device_id(context, subports, '', '')
            res = super(TricircleTrunkDriver, self).remove_subports(
                context, trunk_id, subports)
            mappings = db_api.get_bottom_mappings_by_top_id(
                t_ctx, trunk_id, t_constants.RT_TRUNK)
            if mappings:
                b_pod = mappings[0][0]
                self.xjob_handler.sync_trunk(
                    t_ctx, res['project_id'], trunk_id, b_pod['pod_id'])

        return res

 def get_security_group(self, context, _id, fields=None, tenant_id=None):
     try:
         return self.core_plugin.get_security_group(
             context, _id, fields, tenant_id)
     except q_exceptions.NotFound:
         t_ctx = t_context.get_context_from_neutron_context(context)
         t_sg = self.neutron_handle.handle_get(t_ctx,
                                               'security_group', _id)
         if not t_sg:
             raise ext_sg.SecurityGroupNotFound(id=_id)
         self.core_plugin.create_security_group(context,
                                                {'security_group': t_sg})
         return self.core_plugin.get_security_group(
             context, _id, fields, tenant_id)

 def update_port_chain_precommit(self, context):
     plugin_context = context._plugin_context
     t_ctx = t_context.get_context_from_neutron_context(plugin_context)
     port_chain = context.current
     mappings = db_api.get_bottom_mappings_by_top_id(
         t_ctx, port_chain['id'], t_constants.RT_PORT_CHAIN)
     if mappings:
         net_id = self._get_net_id_by_portpairgroups(
             plugin_context, context._plugin,
             port_chain['port_pair_groups'])
         if not net_id:
             return
         self.xjob_handler.sync_service_function_chain(
             t_ctx, port_chain['project_id'], port_chain['id'],
             net_id, t_constants.POD_NOT_SPECIFIED)