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	`A`	Undocumented
Constant	`A6`	Undocumented
Constant	`AAAA`	Undocumented
Constant	`AFSDB`	Undocumented
Constant	`ALL_RECORDS`	Undocumented
Constant	`ANY`	Undocumented
Constant	`AXFR`	Undocumented
Constant	`CH`	Undocumented
Constant	`CNAME`	Undocumented
Constant	`CS`	Undocumented
Constant	`DNAME`	Undocumented
Constant	`EBADKEY`	Undocumented
Constant	`EBADSIG`	Undocumented
Constant	`EBADTIME`	Undocumented
Constant	`EBADVERSION`	Undocumented
Constant	`EFORMAT`	Undocumented
Constant	`ENAME`	Undocumented
Constant	`ENOTIMP`	Undocumented
Constant	`EREFUSED`	Undocumented
Constant	`ESERVER`	Undocumented
Constant	`EXT_QUERIES`	Undocumented
Constant	`HINFO`	Undocumented
Constant	`HS`	Undocumented
Constant	`IN`	Undocumented
Constant	`IXFR`	Undocumented
Constant	`MAILA`	Undocumented
Constant	`MAILB`	Undocumented
Constant	`MB`	Undocumented
Constant	`MD`	Undocumented
Constant	`MF`	Undocumented
Constant	`MG`	Undocumented
Constant	`MINFO`	Undocumented
Constant	`MR`	Undocumented
Constant	`MX`	Undocumented
Constant	`NAPTR`	Undocumented
Constant	`NS`	Undocumented
Constant	`NULL`	Undocumented
Constant	`OK`	Undocumented
Constant	`OP_INVERSE`	Undocumented
Constant	`OP_NOTIFY`	Undocumented
Constant	`OP_QUERY`	Undocumented
Constant	`OP_STATUS`	Undocumented
Constant	`OP_UPDATE`	Undocumented
Constant	`OPT`	Undocumented
Constant	`PORT`	Undocumented
Constant	`PTR`	Undocumented
Constant	`QUERY_CLASSES`	Undocumented
Constant	`QUERY_TYPES`	Undocumented
Constant	`REV_CLASSES`	Undocumented
Constant	`REV_TYPES`	Undocumented
Constant	`RP`	Undocumented
Constant	`SOA`	Undocumented
Constant	`SPF`	Undocumented
Constant	`SRV`	Undocumented
Constant	`SSHFP`	Undocumented
Constant	`TKEY`	Undocumented
Constant	`TSIG`	Undocumented
Constant	`TXT`	Undocumented
Constant	`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`.

def domainString(domain): (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 `str`	A domain name. If passed as a text string it will be `idna` encoded.
Returns
`bytes`	`bytes` 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
`bytes`	Undocumented

def readPrecisely(file, l): (source)

Undocumented

def str2time(s): (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
an `int` giving the interval represented by the string `s`, or whatever `s` is if it is not a string.

A = (source)

Undocumented

A6: int = (source)

Undocumented

Value

AAAA: int = (source)

Undocumented

Value

AFSDB = (source)

Undocumented

ALL_RECORDS = (source)

Undocumented

ANY: int = (source)

Undocumented

Value

AXFR = (source)

Undocumented

CH = (source)

Undocumented

CNAME = (source)

Undocumented

CS = (source)

Undocumented

DNAME: int = (source)

Undocumented

Value

EBADKEY = (source)

Undocumented

EBADSIG = (source)

Undocumented

EBADTIME = (source)

Undocumented

EBADVERSION: int = (source)

Undocumented

Value

EFORMAT = (source)

Undocumented

ENAME = (source)

Undocumented

ENOTIMP = (source)

Undocumented

EREFUSED = (source)

Undocumented

ESERVER = (source)

Undocumented

EXT_QUERIES = (source)

Undocumented

Value

{IXFR: 'IXFR',
 AXFR: 'AXFR',
 MAILB: 'MAILB',
 MAILA: 'MAILA',
 ALL_RECORDS: 'ALL_RECORDS'}

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

NAPTR: int = (source)

Undocumented

Value

NS = (source)

Undocumented

NULL = (source)

Undocumented

OK = (source)

Undocumented

OP_INVERSE = (source)

Undocumented

OP_NOTIFY: int = (source)

Undocumented

Value

OP_QUERY = (source)

Undocumented

OP_STATUS = (source)

Undocumented

OP_UPDATE: int = (source)

Undocumented

Value

OPT: int = (source)

Undocumented

Value

PORT: int = (source)

Undocumented

Value

PTR = (source)

Undocumented

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())}

RP = (source)

Undocumented

SOA = (source)

Undocumented

SPF: int = (source)

Undocumented

Value

SRV: int = (source)

Undocumented

Value

SSHFP: int = (source)

Undocumented

Value

TKEY: int = (source)

Undocumented

Value

TSIG: int = (source)

Undocumented

Value

TXT = (source)

Undocumented

WKS = (source)

Undocumented

def _compactRepr(obj, alwaysShow=None, flagNames=None, fieldNames=None, sectionNames=None): (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	The instance whose repr is being generated.
alwaysShow	A `list` of field names which should always be shown.
flagNames	A `list` of flag attribute names which should be shown if they are `True`.
fieldNames	A `list` of field attribute names which should be shown if they have non-default values.
sectionNames	A `list` of section attribute names which should be shown if they have been assigned a value.
Returns
A `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
obj	The instance whose repr is being generated.
alwaysShow	A `list` of field names which should always be shown.
fieldNames	A `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:`bytes`	The DNS subdomain name.
ancestorName:`bytes`	The 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:`bytes`	A fully qualified domain name (with or without a trailing dot).
Returns
`list` of `bytes`	A `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
bytes	The bytes to represent.
Returns
`str`	Undocumented

def _nicebyteslist(list): (source)

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

Parameters
list	The list of bytes to represent.
Returns
`str`	Undocumented

def _ord2bytes(ordinal): (source)

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

Parameters
ordinal:`int`	Undocumented
Returns
`bytes`	Undocumented

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:`callable`	A response message constructor with an initializer signature matching `dns.Message.__init__`.
message:`Message`	A request message.
**kwargs:`dict`	Keyword arguments which will be passed to the initialiser of the response message.
Returns
`responseConstructor`	A `Message` like response instance.