twisted.names.dns.

class documentation

An OPT record header.

See Also
`_OPTHeader.__init__` for documentation of other public instance attributes.
https://tools.ietf.org/html/rfc6891#section-6.1.2

Present Since
13.2

Class Method	`fromRRHeader`	A classmethod for constructing a new `_OPTHeader` from the attributes and payload of an existing `RRHeader` instance.
Method	`__init__`	No summary
Method	`decode`	Decode bytes into an `_OPTHeader` instance.
Method	`encode`	Encode this `_OPTHeader` instance to bytes.
Class Variable	`compareAttributes`	Undocumented
Class Variable	`showAttributes`	Undocumented
Instance Variable	`dnssecOK`	Undocumented
Instance Variable	`extendedRCODE`	Undocumented
Instance Variable	`options`	Undocumented
Instance Variable	`udpPayloadSize`	Undocumented
Instance Variable	`version`	Undocumented
Property	`name`	A readonly property for accessing the `name` attribute of this record.
Property	`type`	A readonly property for accessing the `type` attribute of this record.

Inherited from FancyStrMixin:

Method __str__ Undocumented

Inherited from FancyEqMixin (via FancyStrMixin):

Method	`__eq__`	Undocumented
Method	`__ne__`	Undocumented

@classmethod

A classmethod for constructing a new _OPTHeader from the attributes and payload of an existing RRHeader instance.

Parameters
rrHeader:`RRHeader`	An `RRHeader` instance containing an `UnknownRecord` payload.

Returns
`_OPTHeader`	An instance of `_OPTHeader`.

def __init__(self, udpPayloadSize=4096, extendedRCODE=0, version=0, dnssecOK=False, options=None): (source) ¶

Parameters
udpPayloadSize:`int`	The number of octets of the largest UDP payload that can be reassembled and delivered in the requestor's network stack.
extendedRCODE:`int`	Forms the upper 8 bits of extended 12-bit RCODE (together with the 4 bits defined in [RFC1035]. Note that EXTENDED-RCODE value 0 indicates that an unextended RCODE is in use (values 0 through 15).
version:`int`	Indicates the implementation level of the setter. Full conformance with this specification is indicated by version `0`.
dnssecOK:`bool`	DNSSEC OK bit as defined by [RFC3225].
options:`list`	A `list` of 0 or more `_OPTVariableOption` instances.

def decode(self, strio, length=None): (source) ¶

from twisted.names.dns.IEncodable

Decode bytes into an _OPTHeader instance.

Parameters
strio:file	Bytes will be read from this file until the full `_OPTHeader` is decoded.
length:`int` or `None`	Not used.

def encode(self, strio, compDict=None): (source) ¶

from twisted.names.dns.IEncodable

Encode this _OPTHeader instance to bytes.

Parameters
strio:file	the byte representation of this `_OPTHeader` will be written to this file.
compDict:`dict` or `None`	A dictionary of backreference addresses that have already been written to this stream and that may be used for DNS name compression.