Source code for dhcpkit.ipv6.extensions.bulk_leasequery

Implementation of the Bulk Leasequery protocol extension as specified in :rfc:`5460`.
from struct import pack
from typing import Union

from dhcpkit.ipv6.duids import DUID
from dhcpkit.ipv6.messages import ClientServerMessage
from dhcpkit.ipv6.options import Option





[docs]class LeasequeryDataMessage(ClientServerMessage): """ The LEASEQUERY-DATA message carries data about a single DHCPv6 client's leases and/or PD bindings on a single link. The purpose of the message is to reduce redundant data when there are multiple bindings to be sent. The LEASEQUERY-DATA message MUST be preceded by a LEASEQUERY-REPLY message. The LEASEQUERY-REPLY carries the query's status, the Leasequery's Client-ID and Server-ID options, and the first client's binding data if the query was successful. LEASEQUERY-DATA MUST ONLY be sent in response to a successful LEASEQUERY, and only if more than one client's data is to be sent. The LEASEQUERY-DATA message's transaction-id field MUST match the transaction-id of the LEASEQUERY request message. The Server-ID, Client-ID, and OPTION_STATUS_CODE options SHOULD NOT be included: that data should be constant for any one Bulk Leasequery reply, and should have been conveyed in the LEASEQUERY-REPLY message. """ message_type = MSG_LEASEQUERY_DATA from_server_to_client = True
[docs]class LeasequeryDoneMessage(ClientServerMessage): """ The LEASEQUERY-DONE message indicates the end of a group of related Leasequery replies. The LEASEQUERY-DONE message's transaction-id field MUST match the transaction-id of the LEASEQUERY request message. The presence of the message itself signals the end of a stream of reply messages. A single LEASEQUERY-DONE MUST BE sent after all replies (a successful LEASEQUERY-REPLY and zero or more LEASEQUERY-DATA messages) to a successful Bulk Leasequery request that returned at least one binding. A server may encounter an error condition after it has sent the initial LEASEQUERY-REPLY. In that case, it SHOULD attempt to send a LEASEQUERY-DONE with an OPTION_STATUS_CODE option indicating the error condition to the requestor. Other DHCPv6 options SHOULD NOT be included in the LEASEQUERY-DONE message. """ message_type = MSG_LEASEQUERY_DONE from_server_to_client = True
[docs]class RelayIdOption(Option): """ :rfc:`5460#section-5.4.1` The Relay-ID option carries a DUID [RFC3315]. A relay agent MAY include the option in Relay-Forward messages it sends. Obviously, it will not be possible for a server to respond to QUERY_BY_RELAY_ID queries unless the relay agent has included this option. A relay SHOULD be able to generate a DUID for this purpose, and capture the result in stable storage. A relay SHOULD also allow the DUID value to be configurable: doing so allows an administrator to replace a relay agent while retaining the association between the relay and existing DHCPv6 bindings. A DHCPv6 server MAY associate Relay-ID options from Relay-Forward messages it processes with prefix delegations and/or lease bindings that result. Doing so allows it to respond to QUERY_BY_RELAY_ID Leasequeries. The format of the Relay-ID option is shown below: .. code-block:: none 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_RELAY_ID | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . DUID . . (variable length) . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code OPTION_RELAY_ID (53). option-len Length of DUID in octets. DUID The DUID for the relay agent. :type duid: DUID """ option_type = OPTION_RELAY_ID def __init__(self, duid: DUID = None): self.duid = duid """The DUID of the relay agent"""
[docs] def validate(self): """ Validate that the contents of this object conform to protocol specs. """ if not isinstance(self.duid, DUID): raise ValueError("DUID is not a DUID object") self.duid.validate()
[docs] def load_from(self, buffer: bytes, offset: int = 0, length: int = None) -> int: """ Load the internal state of this object from the given buffer. The buffer may contain more data after the structured element is parsed. This data is ignored. :param buffer: The buffer to read data from :param offset: The offset in the buffer where to start reading :param length: The amount of data we are allowed to read from the buffer :return: The number of bytes used from the buffer """ my_offset, option_len = self.parse_option_header(buffer, offset, length, min_length=2) duid_len, self.duid = DUID.parse(buffer, offset=offset + my_offset, length=option_len) my_offset += duid_len return my_offset
[docs] def save(self) -> Union[bytes, bytearray]: """ Save the internal state of this object as a buffer. :return: The buffer with the data from this element """ duid_buffer = return pack('!HH', self.option_type, len(duid_buffer)) + duid_buffer