twisted.names.dns

module documentation
(source)

DNS protocol implementation.

Future Plans:

  • Get rid of some toplevels, maybe.
Interface IEncodable Interface for something which can be encoded to and decoded to the DNS wire format.
Interface IEncodableRecord Interface for DNS records that can be encoded and decoded.
Interface IRecord A single entry in a zone of authority.
Class Charstr No class docstring; 0/1 instance variable, 3/6 methods documented
Class DNSDatagramProtocol DNS protocol over UDP.
Class DNSMixin DNS protocol mixin shared by UDP and TCP implementations.
Class DNSProtocol DNS protocol over TCP.
Class Message Message contains all the information represented by a single DNS request or response.
Class Name A name in the domain name system, made up of multiple labels. For example, twistedmatrix.com.
Class Query Represent a single DNS query.
Class Record_A An IPv4 host address.
Class Record_A6 An IPv6 address.
Class Record_AAAA An IPv6 host address.
Class Record_AFSDB Map from a domain name to the name of an AFS cell database server.
Class Record_CNAME The canonical name for an alias.
Class Record_DNAME A non-terminal DNS name redirection.
Class Record_HINFO Host information.
Class Record_MB A mailbox domain name.
Class Record_MD A mail destination.
Class Record_MF A mail forwarder.
Class Record_MG A mail group member.
Class Record_MINFO Mailbox or mail list information.
Class Record_MR A mail rename domain name.
Class Record_MX Mail exchange.
Class Record_NAPTR The location of the server(s) for a specific protocol and domain.
Class Record_NS An authoritative nameserver.
Class Record_NULL A null record.
Class Record_PTR A domain name pointer.
Class Record_RP The responsible person for a domain.
Class Record_SOA Marks the start of a zone of authority.
Class Record_SPF Structurally, freeform text. Semantically, a policy definition, formatted as defined in rfc 4408.
Class Record_SRV The location of the server(s) for a specific protocol and domain.
Class Record_SSHFP A record containing the fingerprint of an SSH key.
Class Record_TSIG A transaction signature, encapsulated in a RR, as described in RFC 2845.
Class Record_TXT Freeform text.
Class Record_WKS A well known service description.
Class RRHeader A resource record header.
Class SimpleRecord A Resource Record which consists of a single RFC 1035 domain-name.
Class UnknownRecord Encapsulate the wire data for unknown record types so that they can pass through the system unchanged.
Function domainString Coerce a domain name string to bytes.
Function randomSource Wrapper around twisted.python.randbytes.RandomFactory.secureRandom to return 2 random bytes.
Function readPrecisely Undocumented
Function str2time Parse a string description of an interval into an integer number of seconds.
Constant A6 Undocumented
Constant AAAA Undocumented
Constant ANY Undocumented
Constant DNAME Undocumented
Constant EBADVERSION Undocumented
Constant EXT_QUERIES Undocumented
Constant NAPTR Undocumented
Constant OP_NOTIFY Undocumented
Constant OP_UPDATE Undocumented
Constant OPT Undocumented
Constant PORT Undocumented
Constant QUERY_CLASSES Undocumented
Constant QUERY_TYPES Undocumented
Constant REV_CLASSES Undocumented
Constant REV_TYPES Undocumented
Constant SPF Undocumented
Constant SRV Undocumented
Constant SSHFP Undocumented
Constant TKEY Undocumented
Constant TSIG Undocumented
Variable A Undocumented
Variable AFSDB Undocumented
Variable ALL_RECORDS Undocumented
Variable AXFR Undocumented
Variable CH Undocumented
Variable CNAME Undocumented
Variable CS Undocumented
Variable EBADKEY Undocumented
Variable EBADSIG Undocumented
Variable EBADTIME Undocumented
Variable EFORMAT Undocumented
Variable ENAME Undocumented
Variable ENOTIMP Undocumented
Variable EREFUSED Undocumented
Variable ESERVER Undocumented
Variable HINFO Undocumented
Variable HS Undocumented
Variable IN Undocumented
Variable IXFR Undocumented
Variable MAILA Undocumented
Variable MAILB Undocumented
Variable MB Undocumented
Variable MD Undocumented
Variable MF Undocumented
Variable MG Undocumented
Variable MINFO Undocumented
Variable MR Undocumented
Variable MX Undocumented
Variable NS Undocumented
Variable NULL Undocumented
Variable OK Undocumented
Variable OP_INVERSE Undocumented
Variable OP_QUERY Undocumented
Variable OP_STATUS Undocumented
Variable PTR Undocumented
Variable RP Undocumented
Variable SOA Undocumented
Variable TXT Undocumented
Variable WKS Undocumented
Class _EDNSMessage An EDNS message.
Class _OPTHeader An OPT record header.
Class _OPTVariableOption A class to represent OPT record variable options.
Function _compactRepr Return a str representation of obj which only shows fields with non-default values, flags which are True and sections which have been explicitly set.
Function _getDisplayableArguments Inspect the function signature of obj's constructor, and get a list of which arguments should be displayed. This is a helper function for _compactRepr.
Function _isSubdomainOf Test whether descendantName is equal to or is a subdomain of ancestorName.
Function _nameToLabels Split a domain name into its constituent labels.
Function _nicebytes Represent a mostly textful bytes object in a way suitable for presentation to an end user.
Function _nicebyteslist Represent a list of mostly textful bytes objects in a way suitable for presentation to an end user.
Function _ord2bytes Construct a bytes object representing a single byte with the given ordinal value.
Function _responseFromMessage Generate a Message like instance suitable for use as the response to message.
Function _str2time mypy doesn't like type-punning str | bytes | int | None into a str so we have this helper function.
def domainString(domain: str | bytes) -> bytes: (source)

Coerce a domain name string to bytes.

twisted.names represents domain names as bytes, but many interfaces accept bytes or a text string (unicode on Python 2, str on Python 3). This function coerces text strings using IDNA encoding --- see encodings.idna.

Note that DNS is case insensitive but case preserving. This function doesn't normalize case, so you'll still need to do that whenever comparing the strings it returns.

Parameters
domain:bytes or strA domain name. If passed as a text string it will be idna encoded.
Returns
bytesbytes suitable for network transmission.
Present Since
Twisted 20.3.0
def randomSource(): (source)

Wrapper around twisted.python.randbytes.RandomFactory.secureRandom to return 2 random bytes.

Returns
bytesUndocumented
def readPrecisely(file, l): (source)

Undocumented

@overload
def str2time(s: str | bytes | int) -> int:
@overload
def str2time(s: None):
(source)

Parse a string description of an interval into an integer number of seconds.

Parameters
s:text string (bytes or str) for parsing; anything else for passthrough.An interval definition constructed as an interval duration followed by an interval unit. An interval duration is a base ten representation of an integer. An interval unit is one of the following letters: S (seconds), M (minutes), H (hours), D (days), W (weeks), or Y (years). For example: "3S" indicates an interval of three seconds; "5D" indicates an interval of five days. Alternatively, s may be any non-string and it will be returned unmodified.
Returns
int | Nonean int giving the interval represented by the string s, or whatever s is if it is not a string.
A6: int = (source)

Undocumented

Value
38
AAAA: int = (source)

Undocumented

Value
28
ANY: int = (source)

Undocumented

Value
255
DNAME: int = (source)

Undocumented

Value
39
EBADVERSION: int = (source)

Undocumented

Value
16
EXT_QUERIES = (source)

Undocumented

Value
{IXFR: 'IXFR',
 AXFR: 'AXFR',
 MAILB: 'MAILB',
 MAILA: 'MAILA',
 ALL_RECORDS: 'ALL_RECORDS'}
NAPTR: int = (source)

Undocumented

Value
35
OP_NOTIFY: int = (source)

Undocumented

Value
4
OP_UPDATE: int = (source)

Undocumented

Value
5
OPT: int = (source)

Undocumented

Value
41
PORT: int = (source)

Undocumented

Value
53
QUERY_CLASSES = (source)

Undocumented

Value
{IN: 'IN', CS: 'CS', CH: 'CH', HS: 'HS', ANY: 'ANY'}
QUERY_TYPES = (source)

Undocumented

Value
{A: 'A',
 NS: 'NS',
 MD: 'MD',
 MF: 'MF',
 CNAME: 'CNAME',
 SOA: 'SOA',
 MB: 'MB',
...
REV_CLASSES = (source)

Undocumented

Value
{v: k for k, v in QUERY_CLASSES.items()}
REV_TYPES = (source)

Undocumented

Value
{v: k for k, v in chain(QUERY_TYPES.items(), EXT_QUERIES.items())}
SPF: int = (source)

Undocumented

Value
99
SRV: int = (source)

Undocumented

Value
33
SSHFP: int = (source)

Undocumented

Value
44
TKEY: int = (source)

Undocumented

Value
249
TSIG: int = (source)

Undocumented

Value
250
A = (source)

Undocumented

AFSDB = (source)

Undocumented

ALL_RECORDS = (source)

Undocumented

AXFR = (source)

Undocumented

CH = (source)

Undocumented

CNAME = (source)

Undocumented

CS = (source)

Undocumented

EBADKEY = (source)

Undocumented

EBADSIG = (source)

Undocumented

EBADTIME = (source)

Undocumented

EFORMAT = (source)

Undocumented

ENAME = (source)

Undocumented

ENOTIMP = (source)

Undocumented

EREFUSED = (source)

Undocumented

ESERVER = (source)

Undocumented

HINFO = (source)

Undocumented

HS = (source)

Undocumented

IN = (source)

Undocumented

IXFR = (source)

Undocumented

MAILA = (source)

Undocumented

MAILB = (source)

Undocumented

MB = (source)

Undocumented

MD = (source)

Undocumented

MF = (source)

Undocumented

MG = (source)

Undocumented

MINFO = (source)

Undocumented

MR = (source)

Undocumented

MX = (source)

Undocumented

NS = (source)

Undocumented

NULL = (source)

Undocumented

OK = (source)

Undocumented

OP_INVERSE = (source)

Undocumented

OP_QUERY = (source)

Undocumented

OP_STATUS = (source)

Undocumented

PTR = (source)

Undocumented

RP = (source)

Undocumented

SOA = (source)

Undocumented

TXT = (source)

Undocumented

WKS = (source)

Undocumented

def _compactRepr(obj: object, alwaysShow: Sequence[str] | None = None, flagNames: Sequence[str] | None = None, fieldNames: Sequence[str] | None = None, sectionNames: Sequence[str] | None = None) -> str: (source)

Return a str representation of obj which only shows fields with non-default values, flags which are True and sections which have been explicitly set.

Parameters
obj:objectThe instance whose repr is being generated.
alwaysShow:Sequence[str] | NoneA list of field names which should always be shown.
flagNames:Sequence[str] | NoneA list of flag attribute names which should be shown if they are True.
fieldNames:Sequence[str] | NoneA list of field attribute names which should be shown if they have non-default values.
sectionNames:Sequence[str] | NoneA list of section attribute names which should be shown if they have been assigned a value.
Returns
strA str representation of obj.
def _getDisplayableArguments(obj, alwaysShow, fieldNames): (source)

Inspect the function signature of obj's constructor, and get a list of which arguments should be displayed. This is a helper function for _compactRepr.

Parameters
objThe instance whose repr is being generated.
alwaysShowA list of field names which should always be shown.
fieldNamesA list of field attribute names which should be shown if they have non-default values.
Returns
A list of displayable arguments.
def _isSubdomainOf(descendantName, ancestorName): (source)

Test whether descendantName is equal to or is a subdomain of ancestorName.

The names are compared case-insensitively.

The names are treated as byte strings containing one or more DNS labels separated by ..

descendantName is considered equal if its sequence of labels exactly matches the labels of ancestorName.

descendantName is considered a subdomain if its sequence of labels ends with the labels of ancestorName.

Parameters
descendantName:bytesThe DNS subdomain name.
ancestorName:bytesThe DNS parent or ancestor domain name.
Returns
True if descendantName is equal to or if it is a subdomain of ancestorName. Otherwise returns False.
def _nameToLabels(name): (source)

Split a domain name into its constituent labels.

Parameters
name:bytesA fully qualified domain name (with or without a trailing dot).
Returns
list of bytesA list of labels ending with an empty label representing the DNS root zone.
def _nicebytes(bytes): (source)

Represent a mostly textful bytes object in a way suitable for presentation to an end user.

Parameters
bytesThe bytes to represent.
Returns
strUndocumented
def _nicebyteslist(list): (source)

Represent a list of mostly textful bytes objects in a way suitable for presentation to an end user.

Parameters
listThe list of bytes to represent.
Returns
strUndocumented
def _ord2bytes(ordinal): (source)

Construct a bytes object representing a single byte with the given ordinal value.

Parameters
ordinal:intUndocumented
Returns
bytesUndocumented
def _responseFromMessage(responseConstructor, message, **kwargs): (source)

Generate a Message like instance suitable for use as the response to message.

The queries, id attributes will be copied from message and the answer flag will be set to True.

Parameters
responseConstructor:callableA response message constructor with an initializer signature matching dns.Message.__init__.
message:MessageA request message.
**kwargs:dictKeyword arguments which will be passed to the initialiser of the response message.
Returns
responseConstructorA Message like response instance.
def _str2time(s: str) -> int: (source)

mypy doesn't like type-punning str | bytes | int | None into a str so we have this helper function.