text: #    (c) Copyright 2014 Brocade Communications Systems Inc.
  #    All Rights Reserved.
  #
  #    Copyright 2014 OpenStack Foundation
  #
  #    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.
  #
  """
  ZoneManager is responsible to manage access control using FC zoning
  when zoning mode is set as 'fabric'.
  ZoneManager provides interfaces to add connection and remove connection
  for given initiator and target list associated with a FC volume attach and
  detach operation.
  
  **Related Flags**
  
  :zone_driver:  Used by:class:`ZoneManager`.
      Defaults to
      `cinder.zonemanager.drivers.brocade.brcd_fc_zone_driver.BrcdFCZoneDriver`
  :zoning_policy: Used by: class: 'ZoneManager'. Defaults to 'none'
  
  """
  
  from oslo.config import cfg
  
  from cinder import exception
  from cinder.openstack.common import importutils
  from cinder.openstack.common import log as logging
  from cinder.volume import configuration as config
  from cinder.zonemanager import fc_common
  
  LOG = logging.getLogger(__name__)
  
  zone_manager_opts = [
      cfg.StrOpt('zone_driver',
                 default='cinder.zonemanager.drivers.brocade.brcd_fc_zone_driver'
                 '.BrcdFCZoneDriver',
                 help='FC Zone Driver responsible for zone management'),
      cfg.StrOpt('zoning_policy',
                 default='initiator-target',
                 help='Zoning policy configured by user'),
      cfg.StrOpt('fc_fabric_names',
                 default=None,
                 help='Comma separated list of fibre channel fabric names.'
                 ' This list of names is used to retrieve other SAN credentials'
                 ' for connecting to each SAN fabric'),
      cfg.StrOpt('fc_san_lookup_service',
                 default='cinder.zonemanager.drivers.brocade'
                 '.brcd_fc_san_lookup_service.BrcdFCSanLookupService',
                 help='FC San Lookup Service'),
  ]
  
  CONF = cfg.CONF
  CONF.register_opts(zone_manager_opts, 'fc-zone-manager')
  
  
  class ZoneManager(fc_common.FCCommon):
      """Manages Connection control during attach/detach."""
  
      VERSION = "1.0"
      driver = None
      fabric_names = []
  
      def __init__(self, **kwargs):
          """Load the driver from the one specified in args, or from flags."""
          super(ZoneManager, self).__init__(**kwargs)
  
          self.configuration = kwargs.get('configuration', None)
          if self.configuration:
              self.configuration.append_config_values(zone_manager_opts)
  
          zone_driver = self.configuration.zone_driver
          LOG.debug("Zone Driver from config: {%s}", zone_driver)
  
          zm_config = config.Configuration(zone_manager_opts, 'fc-zone-manager')
          # Initialize vendor specific implementation of  FCZoneDriver
          self.driver = importutils.import_object(
              zone_driver,
              configuration=zm_config)
  
      def get_zoning_state_ref_count(self, initiator_wwn, target_wwn):
          """Zone management state check.
  
          Performs state check for given I-T pair to return the current count of
          active attach for the pair.
          """
          # TODO(sk): ref count state management
          count = 0
          # check the state for I-T pair
          return count
  
      def add_connection(self, initiator_target_map):
          """Add connection control.
  
          Adds connection control for the given initiator target map.
          initiator_target_map - each initiator WWN mapped to a list of one
          or more target WWN:
          eg:
          {
              '10008c7cff523b01': ['20240002ac000a50', '20240002ac000a40']
          }
          """
          connected_fabric = None
          try:
              for initiator in initiator_target_map.keys():
                  target_list = initiator_target_map[initiator]
                  LOG.debug("Target List :%s", {initiator: target_list})
  
                  # get SAN context for the target list
                  fabric_map = self.get_san_context(target_list)
                  LOG.debug("Fabric Map after context lookup:%s", fabric_map)
                  # iterate over each SAN and apply connection control
                  for fabric in fabric_map.keys():
                      connected_fabric = fabric
                      t_list = fabric_map[fabric]
                      # get valid I-T map to add connection control
                      i_t_map = {initiator: t_list}
                      valid_i_t_map = self.get_valid_initiator_target_map(
                          i_t_map, True)
                      LOG.info(_("Final filtered map for fabric: %s"),
                               {fabric: valid_i_t_map})
  
                      # Call driver to add connection control
                      self.driver.add_connection(fabric, valid_i_t_map)
  
              LOG.info(_("Add Connection: Finished iterating "
                         "over all target list"))
          except Exception as e:
              msg = _("Failed adding connection for fabric=%(fabric)s: "
                      "Error:%(err)s") % {'fabric': connected_fabric,
                                          'err': e}
              LOG.error(msg)
              raise exception.ZoneManagerException(reason=msg)
  
      def delete_connection(self, initiator_target_map):
          """Delete connection.
  
          Updates/deletes connection control for the given initiator target map.
          initiator_target_map - each initiator WWN mapped to a list of one
          or more target WWN:
          eg:
          {
              '10008c7cff523b01': ['20240002ac000a50', '20240002ac000a40']
          }
          """
          connected_fabric = None
          try:
              for initiator in initiator_target_map.keys():
                  target_list = initiator_target_map[initiator]
                  LOG.info(_("Delete connection Target List:%s"),
                           {initiator: target_list})
  
                  # get SAN context for the target list
                  fabric_map = self.get_san_context(target_list)
                  LOG.debug("Delete connection Fabric Map from SAN "
                            "context: %s", fabric_map)
  
                  # iterate over each SAN and apply connection control
                  for fabric in fabric_map.keys():
                      connected_fabric = fabric
                      t_list = fabric_map[fabric]
                      # get valid I-T map to add connection control
                      i_t_map = {initiator: t_list}
                      valid_i_t_map = self.get_valid_initiator_target_map(
                          i_t_map, False)
                      LOG.info(_("Final filtered map for delete "
                                 "connection: %s"), valid_i_t_map)
  
                      # Call driver to delete connection control
                      if len(valid_i_t_map) > 0:
                          self.driver.delete_connection(fabric, valid_i_t_map)
  
              LOG.debug("Delete Connection - Finished iterating over all"
                        " target list")
          except Exception as e:
              msg = _("Failed removing connection for fabric=%(fabric)s: "
                      "Error:%(err)s") % {'fabric': connected_fabric,
                                          'err': e}
              LOG.error(msg)
              raise exception.ZoneManagerException(reason=msg)
  
      def get_san_context(self, target_wwn_list):
          """SAN lookup for end devices.
  
          Look up each SAN configured and return a map of SAN (fabric IP)
          to list of target WWNs visible to the fabric.
          """
          fabric_map = self.driver.get_san_context(target_wwn_list)
          LOG.debug("Got SAN context:%s", fabric_map)
          return fabric_map
  
      def get_valid_initiator_target_map(self, initiator_target_map,
                                         add_control):
          """Reference count check for end devices.
  
          Looks up the reference count for each initiator-target pair from the
          map and returns a filtered list based on the operation type
          add_control - operation type can be true for add connection control
          and false for remove connection control
          """
          filtered_i_t_map = {}
          for initiator in initiator_target_map.keys():
              t_list = initiator_target_map[initiator]
              for target in t_list:
                  count = self.get_zoning_state_ref_count(initiator, target)
                  if add_control:
                      if count > 0:
                          t_list.remove(target)
                      # update count = count + 1
                  else:
                      if count > 1:
                          t_list.remove(target)
                      # update count = count - 1
              if t_list:
                  filtered_i_t_map[initiator] = t_list
              else:
                  LOG.info(_("No targets to add or remove connection for "
                             "I: %s"), initiator)
          return filtered_i_t_map
  