`std/dns/codes`

std/dns/src/codes.trb

The numbers of the DNS as closed sets: RecordType, RecordClass, Operation and ResponseCode. Each has a case for every code this package knows and Other(code) for the rest, and each compares by its code, so RecordType.Other(1) == RecordType.A - a number read from the wire and a case written in a program are one value.

type RecordType

type RecordType with Show, Equals, Hash

The type of a record, or of the records a question asks for (RFC 1035 section 3.2.2, and the registry of IANA's "Resource Record (RR) TYPEs" for the later ones).

Examples

print RecordType.of(28)
print RecordType.Https.code()

case A

case A

An IPv4 address, 1.

case Ns

case Ns

An authoritative name server, 2.

case Cname

case Cname

The canonical name of an alias, 5.

case Soa

case Soa

The start of a zone of authority, 6.

case Ptr

case Ptr

A pointer to another name, 12: the reverse lookup of an address.

case Mx

case Mx

A mail exchange, 15.

case Txt

case Txt

Text strings, 16.

case Aaaa

case Aaaa

An IPv6 address, 28 (RFC 3596).

case Srv

case Srv

The location of a service, 33 (RFC 2782).

case Opt

case Opt

The EDNS0 pseudo-record, 41 (RFC 6891).

case Svcb

case Svcb

A service binding, 64 (RFC 9460).

case Https

case Https

A service binding for HTTPS, 65 (RFC 9460).

case Any

case Any

Every record of a name, 255: a question only.

case Caa

case Caa

A certification authority authorization, 257 (RFC 8659).

case Other

case Other(code: Int)

Any other type, by its number from 0 to 65535.

fn of

static fn of(code: Int): Self

The type of the number code, a named case where there is one. Taken modulo 65536.

fn code

fn code(): Int

The number on the wire.

fn show

fn show(): String

The mnemonic of a zone file: AAAA, HTTPS, and TYPE65280 for a type without one (RFC 3597 section 5).

fn equals

fn equals(other: RecordType): Bool

By the code.

fn hash

fn hash(): Int

Not documented.

type RecordClass

type RecordClass with Show, Equals, Hash

The class of a record (RFC 1035 section 3.2.4). Everything on the Internet is Internet.

case Internet

case Internet

IN, 1.

case Chaos

case Chaos

CH, 3: Chaosnet, still used for version.bind.

case Hesiod

case Hesiod

HS, 4: Hesiod.

case Any

case Any

ANY, 255: a question only.

case Other

case Other(code: Int)

Any other class, by its number from 0 to 65535.

fn of

static fn of(code: Int): Self

The class of the number code, a named case where there is one. Taken modulo 65536.

fn code

fn code(): Int

The number on the wire.

fn show

fn show(): String

IN, CH, HS, ANY, and CLASS{n} for the rest (RFC 3597 section 5).

fn equals

fn equals(other: RecordClass): Bool

By the code.

fn hash

fn hash(): Int

Not documented.

type Operation

type Operation with Show, Equals, Hash

What a message asks the server to do: the four bits of OPCODE (RFC 1035 section 4.1.1).

case Query

case Query

A standard query, 0.

case Status

case Status

A server status request, 2.

case Notify

case Notify

A zone change notification, 4 (RFC 1996).

case Update

case Update

A dynamic update, 5 (RFC 2136).

case Other

case Other(code: Int)

Any other operation, by its number from 0 to 15.

fn of

static fn of(code: Int): Self

The operation of the number code, a named case where there is one. Taken modulo 16.

fn code

fn code(): Int

The four bits on the wire.

fn show

fn show(): String

QUERY, STATUS, NOTIFY, UPDATE, and OPCODE{n} for the rest.

fn equals

fn equals(other: Operation): Bool

By the code.

fn hash

fn hash(): Int

Not documented.

type ResponseCode

type ResponseCode with Show, Equals, Hash

How a server answered: the twelve bits of the response code, four in the header and eight more in the EDNS0 record (RFC 6891 section 6.1.3). A name that does not exist is NameError, the NXDOMAIN of the tools.