"""
Basic handlers for relay options
"""
import logging
from dhcpkit.ipv6.messages import RelayForwardMessage, RelayReplyMessage
from dhcpkit.ipv6.server.handlers import Handler, RelayHandler
from dhcpkit.ipv6.server.transaction_bundle import TransactionBundle
logger = logging.getLogger(__name__)
[docs]class CopyRelayOptionHandler(RelayHandler):
"""
This handler just copies a type of option from the incoming relay messages to the outgoing relay messages
:param option_class: The option class to copy
"""
def __init__(self, option_class: type(Handler)):
super().__init__()
self.option_class = option_class
"""The class of the option from the :class:`.RelayForwardMessage` to the :class:`.RelayReplyMessage`"""
[docs] def handle_relay(self, bundle: TransactionBundle,
relay_message_in: RelayForwardMessage, relay_message_out: RelayReplyMessage):
"""
Copy the options for each relay message pair.
:param bundle: The transaction bundle
:param relay_message_in: The incoming relay message
:param relay_message_out: Thr outgoing relay message
"""
# Make sure this option can go into this type of response
if not relay_message_out.may_contain(self.option_class):
return
# Make sure this option isn't present and then copy those from the request
relay_message_out.options = [existing_option for existing_option in relay_message_out.options
if not isinstance(existing_option, self.option_class)]
relay_message_out.options[:0] = relay_message_in.get_options_of_type(self.option_class)