Module refinery.lib.dns

DNS wire-format parser implementing RFC 1035 message parsing with support for name compression, common record types, and EDNS(0). The main entry point is parse_dns_message(), which returns a DnsMessage built entirely from enum.Enum and typing.NamedTuple values rather than dictionaries.

"""
DNS wire-format parser implementing RFC 1035 message parsing with support for name compression,
common record types, and EDNS(0). The main entry point is `parse_dns_message`, which returns a
`DnsMessage` built entirely from `enum.Enum` and `typing.NamedTuple` values rather than dictionaries.
"""
from __future__ import annotations

import ipaddress

from enum import IntEnum, IntFlag
from typing import NamedTuple

from refinery.lib.structures import EOF, StructReader


class DnsType(IntEnum):
    """
    DNS resource record type codes (RFC 1035, plus common extensions).
    """
    A     = 1  # noqa
    NS    = 2  # noqa
    CNAME = 5  # noqa
    SOA   = 6  # noqa
    PTR   = 12 # noqa
    MX    = 15 # noqa
    TXT   = 16 # noqa
    AAAA  = 28 # noqa
    SRV   = 33 # noqa
    OPT   = 41 # noqa

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'TYPE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj


class DnsClass(IntEnum):
    """
    DNS class codes (RFC 1035).
    """
    IN  = 1  # noqa
    CS  = 2  # noqa
    CH  = 3  # noqa
    HS  = 4  # noqa
    ANY = 255

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'CLASS{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj


class DnsOpcode(IntEnum):
    """
    DNS opcode values from the header flags field.
    """
    QUERY  = 0  # noqa
    IQUERY = 1
    STATUS = 2
    NOTIFY = 4
    UPDATE = 5

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'OPCODE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj


class DnsRcode(IntEnum):
    """
    DNS response code values.
    """
    NOERROR  = 0  # noqa
    FORMERR  = 1  # noqa
    SERVFAIL = 2  # noqa
    NXDOMAIN = 3  # noqa
    NOTIMP   = 4  # noqa
    REFUSED  = 5  # noqa
    YXDOMAIN = 6  # noqa
    YXRRSET  = 7  # noqa
    NXRRSET  = 8  # noqa
    NOTAUTH  = 9  # noqa
    NOTZONE  = 10 # noqa

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'RCODE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj


class DnsQr(IntEnum):
    """
    The query/response bit from the header flags field.
    """
    QUERY    = 0  # noqa
    RESPONSE = 1


class DnsHeaderFlag(IntFlag):
    """
    The single-bit boolean flags carried in the DNS header flags field. Members are declared in the
    order in which they appear from the most significant bit so that iteration yields them in a
    stable, wire-consistent order.
    """
    AA = 1 << 10
    TC = 1 << 9
    RD = 1 << 8
    RA = 1 << 7
    AD = 1 << 5
    CD = 1 << 4


class DnsMX(NamedTuple):
    """
    The parsed payload of an `DnsType.MX` record.
    """
    preference: int
    exchange: str


class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int


class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str


class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool


DnsRData = str | list[str] | DnsMX | DnsSOA | DnsSRV
"""
The union of possible parsed record payloads. Address records resolve to a dotted string, name
records to the referenced domain, text records to a list of strings, and structured records to
their respective `typing.NamedTuple`. Unknown types fall back to a hexadecimal string.
"""


class DnsQuestion(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass


class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData


class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]


_MAX_NAME_LENGTH = 255
_MAX_SECTION_COUNT = 256
_HEADER_LENGTH = 12

_ALL_HEADER_FLAGS = (
    DnsHeaderFlag.AA
    | DnsHeaderFlag.TC
    | DnsHeaderFlag.RD
    | DnsHeaderFlag.RA
    | DnsHeaderFlag.AD
    | DnsHeaderFlag.CD
)


def _read_dns_name(msg: memoryview, start: int) -> tuple[str, int]:
    """
    Read a DNS domain name starting at the given offset within the full message buffer.
    Handles compression pointers (RFC 1035 section 4.1.4). Returns the dotted domain name and
    the number of bytes consumed from the starting offset (which may be less than the full
    resolved name due to pointer indirection).
    """
    labels: list[str] = []
    offset = start
    jumped = False
    bytes_consumed = 0
    visited: set[int] = set()
    total_length = 0

    while True:
        if offset >= len(msg):
            break
        if offset in visited:
            break
        visited.add(offset)

        length = msg[offset]

        if length == 0:
            if not jumped:
                bytes_consumed = offset - start + 1
            break
        elif (length & 0xC0) == 0xC0:
            if offset + 1 >= len(msg):
                if not jumped:
                    bytes_consumed = offset - start + 2
                break
            pointer = ((length & 0x3F) << 8) | msg[offset + 1]
            if not jumped:
                bytes_consumed = offset - start + 2
                jumped = True
            offset = pointer
        elif (length & 0xC0) != 0:
            if not jumped:
                bytes_consumed = offset - start + 1
            break
        else:
            offset += 1
            end = offset + length
            if end > len(msg):
                if not jumped:
                    bytes_consumed = end - start
                break
            total_length += length + 1
            if total_length > _MAX_NAME_LENGTH:
                break
            label = bytes(msg[offset:end])
            labels.append(label.decode('ascii', errors='replace'))
            offset = end

    if not bytes_consumed:
        bytes_consumed = offset - start

    return '.'.join(labels), bytes_consumed


def _parse_rdata(
    msg: memoryview, rtype: DnsType, rdata_offset: int, rdlength: int,
) -> DnsRData:
    available = len(msg) - rdata_offset
    if rdlength > available:
        rdlength = available
    rdata = msg[rdata_offset:rdata_offset + rdlength]
    if rtype == DnsType.A:
        if rdlength >= 4:
            return str(ipaddress.IPv4Address(bytes(rdata[:4])))
    elif rtype == DnsType.AAAA:
        if rdlength >= 16:
            return str(ipaddress.IPv6Address(bytes(rdata[:16])))
    elif rtype in (DnsType.CNAME, DnsType.NS, DnsType.PTR):
        name, _ = _read_dns_name(msg, rdata_offset)
        return name
    elif rtype == DnsType.MX:
        if rdlength >= 3:
            preference = int.from_bytes(rdata[:2], 'big')
            exchange, _ = _read_dns_name(msg, rdata_offset + 2)
            return DnsMX(preference, exchange)
    elif rtype == DnsType.SOA:
        mname, consumed = _read_dns_name(msg, rdata_offset)
        rname, consumed2 = _read_dns_name(msg, rdata_offset + consumed)
        numbers_start = consumed + consumed2
        if rdlength >= numbers_start + 20:
            tail = rdata[numbers_start:]
            return DnsSOA(
                mname=mname,
                rname=rname,
                serial=int.from_bytes(tail[0:4], 'big'),
                refresh=int.from_bytes(tail[4:8], 'big'),
                retry=int.from_bytes(tail[8:12], 'big'),
                expire=int.from_bytes(tail[12:16], 'big'),
                minimum=int.from_bytes(tail[16:20], 'big'),
            )
    elif rtype == DnsType.TXT:
        strings: list[str] = []
        pos = 0
        while pos < rdlength:
            length = rdata[pos]
            pos += 1
            end = min(pos + length, rdlength)
            strings.append(bytes(rdata[pos:end]).decode('latin-1'))
            pos = end
        return strings
    elif rtype == DnsType.SRV:
        if rdlength >= 7:
            priority = int.from_bytes(rdata[0:2], 'big')
            weight = int.from_bytes(rdata[2:4], 'big')
            port = int.from_bytes(rdata[4:6], 'big')
            target, _ = _read_dns_name(msg, rdata_offset + 6)
            return DnsSRV(priority, weight, port, target)
    return bytes(rdata).hex()


def _read_question(msg: memoryview, reader: StructReader) -> DnsQuestion:
    offset = reader.tell()
    name, consumed = _read_dns_name(msg, offset)
    reader.seekrel(consumed)
    qtype = DnsType(reader.u16())
    qclass = DnsClass(reader.u16())
    return DnsQuestion(name, qtype, qclass)


def _read_opt(reader: StructReader) -> DnsOpt:
    udp_size = reader.u16()
    ttl_field = reader.u32()
    rdlength = reader.u16()
    reader.seekrel(rdlength)
    return DnsOpt(
        udp_size=udp_size,
        extended_rcode=(ttl_field >> 24) & 0xFF,
        version=(ttl_field >> 16) & 0xFF,
        do=bool((ttl_field >> 15) & 1),
    )


def _read_record(msg: memoryview, reader: StructReader) -> DnsRecord | DnsOpt:
    offset = reader.tell()
    name, consumed = _read_dns_name(msg, offset)
    reader.seekrel(consumed)
    rtype = DnsType(reader.u16())
    if rtype == DnsType.OPT:
        return _read_opt(reader)
    rclass = DnsClass(reader.u16())
    ttl = reader.i32()
    rdlength = reader.u16()
    rdata_offset = reader.tell()
    reader.seekrel(rdlength)
    data = _parse_rdata(msg, rtype, rdata_offset, rdlength)
    return DnsRecord(name, rtype, rclass, ttl, data)


def _read_section(
    msg: memoryview, reader: StructReader, count: int,
) -> list[DnsRecord | DnsOpt]:
    records: list[DnsRecord | DnsOpt] = []
    for _ in range(min(count, _MAX_SECTION_COUNT)):
        try:
            records.append(_read_record(msg, reader))
        except EOF:
            break
    return records


def parse_dns_message(data: bytes | bytearray | memoryview) -> DnsMessage | None:
    """
    Parse a DNS wire-format message into a `DnsMessage`. Returns `None` if the data is too short to
    contain a valid DNS header.
    """
    msg = memoryview(data)
    if len(msg) < _HEADER_LENGTH:
        return None

    reader = StructReader(msg, bigendian=True)
    try:
        msg_id = reader.u16()
        flags_word = reader.u16()
        qdcount = reader.u16()
        ancount = reader.u16()
        nscount = reader.u16()
        arcount = reader.u16()
    except EOF:
        return None

    qr = DnsQr((flags_word >> 15) & 1)
    opcode = DnsOpcode((flags_word >> 11) & 0xF)
    rcode = DnsRcode(flags_word & 0xF)
    flags = DnsHeaderFlag(flags_word) & _ALL_HEADER_FLAGS

    questions: list[DnsQuestion] = []
    for _ in range(min(qdcount, _MAX_SECTION_COUNT)):
        try:
            questions.append(_read_question(msg, reader))
        except EOF:
            break

    return DnsMessage(
        id=msg_id,
        qr=qr,
        opcode=opcode,
        flags=flags,
        rcode=rcode,
        question=questions,
        answer=_read_section(msg, reader, ancount),
        authority=_read_section(msg, reader, nscount),
        additional=_read_section(msg, reader, arcount),
    )

Global variables

var DnsRData

The union of possible parsed record payloads. Address records resolve to a dotted string, name records to the referenced domain, text records to a list of strings, and structured records to their respective typing.NamedTuple. Unknown types fall back to a hexadecimal string.

Functions

def parse_dns_message(data)

Parse a DNS wire-format message into a DnsMessage. Returns None if the data is too short to contain a valid DNS header.

Expand source code Browse git

def parse_dns_message(data: bytes | bytearray | memoryview) -> DnsMessage | None:
    """
    Parse a DNS wire-format message into a `DnsMessage`. Returns `None` if the data is too short to
    contain a valid DNS header.
    """
    msg = memoryview(data)
    if len(msg) < _HEADER_LENGTH:
        return None

    reader = StructReader(msg, bigendian=True)
    try:
        msg_id = reader.u16()
        flags_word = reader.u16()
        qdcount = reader.u16()
        ancount = reader.u16()
        nscount = reader.u16()
        arcount = reader.u16()
    except EOF:
        return None

    qr = DnsQr((flags_word >> 15) & 1)
    opcode = DnsOpcode((flags_word >> 11) & 0xF)
    rcode = DnsRcode(flags_word & 0xF)
    flags = DnsHeaderFlag(flags_word) & _ALL_HEADER_FLAGS

    questions: list[DnsQuestion] = []
    for _ in range(min(qdcount, _MAX_SECTION_COUNT)):
        try:
            questions.append(_read_question(msg, reader))
        except EOF:
            break

    return DnsMessage(
        id=msg_id,
        qr=qr,
        opcode=opcode,
        flags=flags,
        rcode=rcode,
        question=questions,
        answer=_read_section(msg, reader, ancount),
        authority=_read_section(msg, reader, nscount),
        additional=_read_section(msg, reader, arcount),
    )

Classes

class DnsType (*args, **kwds)

DNS resource record type codes (RFC 1035, plus common extensions).

Expand source code Browse git

class DnsType(IntEnum):
    """
    DNS resource record type codes (RFC 1035, plus common extensions).
    """
    A     = 1  # noqa
    NS    = 2  # noqa
    CNAME = 5  # noqa
    SOA   = 6  # noqa
    PTR   = 12 # noqa
    MX    = 15 # noqa
    TXT   = 16 # noqa
    AAAA  = 28 # noqa
    SRV   = 33 # noqa
    OPT   = 41 # noqa

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'TYPE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj

Ancestors

• enum.IntEnum
• builtins.int
• enum.ReprEnum
• enum.Enum

Class variables

var A

The type of the None singleton.

var NS

The type of the None singleton.

var CNAME

The type of the None singleton.

var SOA

The type of the None singleton.

var PTR

The type of the None singleton.

var MX

The type of the None singleton.

var TXT

The type of the None singleton.

var AAAA

The type of the None singleton.

var SRV

The type of the None singleton.

var OPT

The type of the None singleton.

class DnsClass (*args, **kwds)

DNS class codes (RFC 1035).

Expand source code Browse git

class DnsClass(IntEnum):
    """
    DNS class codes (RFC 1035).
    """
    IN  = 1  # noqa
    CS  = 2  # noqa
    CH  = 3  # noqa
    HS  = 4  # noqa
    ANY = 255

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'CLASS{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj

Ancestors

• enum.IntEnum
• builtins.int
• enum.ReprEnum
• enum.Enum

Class variables

var IN

The type of the None singleton.

var CS

The type of the None singleton.

var CH

The type of the None singleton.

var HS

The type of the None singleton.

var ANY

The type of the None singleton.

class DnsOpcode (*args, **kwds)

DNS opcode values from the header flags field.

Expand source code Browse git

class DnsOpcode(IntEnum):
    """
    DNS opcode values from the header flags field.
    """
    QUERY  = 0  # noqa
    IQUERY = 1
    STATUS = 2
    NOTIFY = 4
    UPDATE = 5

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'OPCODE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj

Ancestors

• enum.IntEnum
• builtins.int
• enum.ReprEnum
• enum.Enum

Class variables

var QUERY

The type of the None singleton.

var IQUERY

The type of the None singleton.

var STATUS

The type of the None singleton.

var NOTIFY

The type of the None singleton.

var UPDATE

The type of the None singleton.

class DnsRcode (*args, **kwds)

DNS response code values.

Expand source code Browse git

class DnsRcode(IntEnum):
    """
    DNS response code values.
    """
    NOERROR  = 0  # noqa
    FORMERR  = 1  # noqa
    SERVFAIL = 2  # noqa
    NXDOMAIN = 3  # noqa
    NOTIMP   = 4  # noqa
    REFUSED  = 5  # noqa
    YXDOMAIN = 6  # noqa
    YXRRSET  = 7  # noqa
    NXRRSET  = 8  # noqa
    NOTAUTH  = 9  # noqa
    NOTZONE  = 10 # noqa

    @classmethod
    def _missing_(cls, value: object):
        obj = int.__new__(cls, int(value))  # type: ignore[arg-type]
        obj._name_ = F'RCODE{value}'
        obj._value_ = int(value)  # type: ignore[assignment]
        return obj

Ancestors

• enum.IntEnum
• builtins.int
• enum.ReprEnum
• enum.Enum

Class variables

var NOERROR

The type of the None singleton.

var FORMERR

The type of the None singleton.

var SERVFAIL

The type of the None singleton.

var NXDOMAIN

The type of the None singleton.

var NOTIMP

The type of the None singleton.

var REFUSED

The type of the None singleton.

var YXDOMAIN

The type of the None singleton.

var YXRRSET

The type of the None singleton.

var NXRRSET

The type of the None singleton.

var NOTAUTH

The type of the None singleton.

var NOTZONE

The type of the None singleton.

class DnsQr (*args, **kwds)

The query/response bit from the header flags field.

Expand source code Browse git

class DnsQr(IntEnum):
    """
    The query/response bit from the header flags field.
    """
    QUERY    = 0  # noqa
    RESPONSE = 1

Ancestors

• enum.IntEnum
• builtins.int
• enum.ReprEnum
• enum.Enum

Class variables

var QUERY

The type of the None singleton.

var RESPONSE

The type of the None singleton.

class DnsHeaderFlag (*args, **kwds)

The single-bit boolean flags carried in the DNS header flags field. Members are declared in the order in which they appear from the most significant bit so that iteration yields them in a stable, wire-consistent order.

Expand source code Browse git

class DnsHeaderFlag(IntFlag):
    """
    The single-bit boolean flags carried in the DNS header flags field. Members are declared in the
    order in which they appear from the most significant bit so that iteration yields them in a
    stable, wire-consistent order.
    """
    AA = 1 << 10
    TC = 1 << 9
    RD = 1 << 8
    RA = 1 << 7
    AD = 1 << 5
    CD = 1 << 4

Ancestors

• enum.IntFlag
• builtins.int
• enum.ReprEnum
• enum.Flag
• enum.Enum

Class variables

var AA

The type of the None singleton.

var TC

The type of the None singleton.

var RD

The type of the None singleton.

var RA

The type of the None singleton.

var AD

The type of the None singleton.

var CD

The type of the None singleton.

class DnsMX (preference, exchange)

The parsed payload of an DnsType.MX record.

Expand source code Browse git

class DnsMX(NamedTuple):
    """
    The parsed payload of an `DnsType.MX` record.
    """
    preference: int
    exchange: str

Ancestors

• builtins.tuple

Instance variables

var preference

Alias for field number 0

Expand source code Browse git

class DnsMX(NamedTuple):
    """
    The parsed payload of an `DnsType.MX` record.
    """
    preference: int
    exchange: str

var exchange

Alias for field number 1

Expand source code Browse git

class DnsMX(NamedTuple):
    """
    The parsed payload of an `DnsType.MX` record.
    """
    preference: int
    exchange: str

class DnsSOA (mname, rname, serial, refresh, retry, expire, minimum)

The parsed payload of an DnsType.SOA record.

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

Ancestors

• builtins.tuple

Instance variables

var mname

Alias for field number 0

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var rname

Alias for field number 1

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var serial

Alias for field number 2

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var refresh

Alias for field number 3

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var retry

Alias for field number 4

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var expire

Alias for field number 5

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

var minimum

Alias for field number 6

Expand source code Browse git

class DnsSOA(NamedTuple):
    """
    The parsed payload of an `DnsType.SOA` record.
    """
    mname: str
    rname: str
    serial: int
    refresh: int
    retry: int
    expire: int
    minimum: int

class DnsSRV (priority, weight, port, target)

The parsed payload of an DnsType.SRV record.

Expand source code Browse git

class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str

Ancestors

• builtins.tuple

Instance variables

var priority

Alias for field number 0

Expand source code Browse git

class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str

var weight

Alias for field number 1

Expand source code Browse git

class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str

var port

Alias for field number 2

Expand source code Browse git

class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str

var target

Alias for field number 3

Expand source code Browse git

class DnsSRV(NamedTuple):
    """
    The parsed payload of an `DnsType.SRV` record.
    """
    priority: int
    weight: int
    port: int
    target: str

class DnsOpt (udp_size, extended_rcode, version, do)

The parsed EDNS(0) pseudo-record (DnsType.OPT). The class and TTL fields of the record header are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field carries the extended response code, the EDNS version, and the DNSSEC OK flag.

Expand source code Browse git

class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool

Ancestors

• builtins.tuple

Instance variables

var udp_size

Alias for field number 0

Expand source code Browse git

class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool

var extended_rcode

Alias for field number 1

Expand source code Browse git

class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool

var version

Alias for field number 2

Expand source code Browse git

class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool

var do

Alias for field number 3

Expand source code Browse git

class DnsOpt(NamedTuple):
    """
    The parsed EDNS(0) pseudo-record (`DnsType.OPT`). The class and TTL fields of the record header
    are repurposed by EDNS(0): the class carries the requestor's UDP payload size and the TTL field
    carries the extended response code, the EDNS version, and the DNSSEC OK flag.
    """
    udp_size: int
    extended_rcode: int
    version: int
    do: bool

class DnsQuestion (name, type, cls)

DnsQuestion(name, type, cls)

Expand source code Browse git

class DnsQuestion(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass

Ancestors

• builtins.tuple

Instance variables

var name

Alias for field number 0

Expand source code Browse git

class DnsQuestion(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass

var type

Alias for field number 1

Expand source code Browse git

class DnsQuestion(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass

var cls

Alias for field number 2

Expand source code Browse git

class DnsQuestion(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass

class DnsRecord (name, type, cls, ttl, data)

DnsRecord(name, type, cls, ttl, data)

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

Ancestors

• builtins.tuple

Instance variables

var name

Alias for field number 0

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

var type

Alias for field number 1

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

var cls

Alias for field number 2

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

var ttl

Alias for field number 3

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

var data

Alias for field number 4

Expand source code Browse git

class DnsRecord(NamedTuple):
    name: str
    type: DnsType
    cls: DnsClass
    ttl: int
    data: DnsRData

class DnsMessage (id, qr, opcode, flags, rcode, question, answer, authority, additional)

A fully parsed DNS message. The four sections are always present as lists and may be empty.

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

Ancestors

• builtins.tuple

Instance variables

var id

Alias for field number 0

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var qr

Alias for field number 1

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var opcode

Alias for field number 2

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var flags

Alias for field number 3

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var rcode

Alias for field number 4

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var question

Alias for field number 5

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var answer

Alias for field number 6

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var authority

Alias for field number 7

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]

var additional

Alias for field number 8

Expand source code Browse git

class DnsMessage(NamedTuple):
    """
    A fully parsed DNS message. The four sections are always present as lists and may be empty.
    """
    id: int
    qr: DnsQr
    opcode: DnsOpcode
    flags: DnsHeaderFlag
    rcode: DnsRcode
    question: list[DnsQuestion]
    answer: list[DnsRecord | DnsOpt]
    authority: list[DnsRecord | DnsOpt]
    additional: list[DnsRecord | DnsOpt]