twisted.names.dns

DNS protocol implementation.

Future Plans:

Get rid of some toplevels, maybe.

Function	randomSource	Wrapper around `twisted.python.randbytes.RandomFactory.secureRandom` to return 2 random bytes.
Interface	IRecord	A single entry in a zone of authority.
Function	domainString	Coerce a domain name string to bytes.
Function	str2time	Parse a string description of an interval into an integer number of seconds.
Function	readPrecisely	Undocumented
Interface	IEncodable	Interface for something which can be encoded to and decoded to the DNS wire format.
Class	Charstr	No class docstring; 3/7 methods documented
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	RRHeader	A resource record header.
Class	SimpleRecord	A Resource Record which consists of a single RFC 1035 domain-name.
Class	Record_NS	An authoritative nameserver.
Class	Record_MD	A mail destination.
Class	Record_MF	A mail forwarder.
Class	Record_CNAME	The canonical name for an alias.
Class	Record_MB	A mailbox domain name.
Class	Record_MG	A mail group member.
Class	Record_MR	A mail rename domain name.
Class	Record_PTR	A domain name pointer.
Class	Record_DNAME	A non-terminal DNS name redirection.
Class	Record_A	An IPv4 host address.
Class	Record_SOA	Marks the start of a zone of authority.
Class	Record_NULL	A null record.
Class	Record_WKS	A well known service description.
Class	Record_AAAA	An IPv6 host address.
Class	Record_A6	An IPv6 address.
Class	Record_SRV	The location of the server(s) for a specific protocol and domain.
Class	Record_NAPTR	The location of the server(s) for a specific protocol and domain.
Class	Record_AFSDB	Map from a domain name to the name of an AFS cell database server.
Class	Record_RP	The responsible person for a domain.
Class	Record_HINFO	Host information.
Class	Record_MINFO	Mailbox or mail list information.
Class	Record_MX	Mail exchange.
Class	Record_SSHFP	A record containing the fingerprint of an SSH key.
Class	Record_TXT	Freeform text.
Class	UnknownRecord	Encapsulate the wire data for unknown record types so that they can pass through the system unchanged.
Class	Record_SPF	Structurally, freeform text. Semantically, a policy definition, formatted as defined in rfc 4408.
Class	Record_TSIG	A transaction signature, encapsulated in a RR, as described in RFC 2845.
Class	Message	`Message` contains all the information represented by a single DNS request or response.
Class	DNSMixin	DNS protocol mixin shared by UDP and TCP implementations.
Class	DNSDatagramProtocol	DNS protocol over UDP.
Class	DNSProtocol	DNS protocol over TCP.
Function	_ord2bytes	Construct a bytes object representing a single byte with the given ordinal value.
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	_nameToLabels	Split a domain name into its constituent labels.
Function	_isSubdomainOf	Test whether `descendantName` is equal to or is a subdomain of `ancestorName`.
Class	_OPTHeader	An OPT record header.
Class	_OPTVariableOption	A class to represent OPT record variable options.
Function	_responseFromMessage	Generate a `Message` like instance suitable for use as the response to `message`.
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	_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.
Class	_EDNSMessage	An EDNS message.

def _ord2bytes(ordinal):

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

Returns (type: bytes)

def _nicebytes(bytes):

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

Parameters	bytes	The bytes to represent.
Returns	(type: `str`)

def _nicebyteslist(list):

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	(type: `str`)

def randomSource():

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

Returns (type: bytes)

def _nameToLabels(name):

Split a domain name into its constituent labels.

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

def domainString(domain):

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	A domain name. If passed as a text string it will be `idna` encoded. (type: `bytes` or `str`)
Returns	`bytes` suitable for network transmission. (type: `bytes`)
Present Since	Twisted 20.3.0

def _isSubdomainOf(descendantName, ancestorName):

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	The DNS subdomain name. (type: `bytes`)
	ancestorName	The DNS parent or ancestor domain name. (type: `bytes`)
Returns	`True` if `descendantName` is equal to or if it is a subdomain of `ancestorName`. Otherwise returns `False`.

def str2time(s):

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

Parameters	s	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. (type: text string (`bytes` or `unicode`) for parsing; anything else for passthrough.)
Returns	an `int` giving the interval represented by the string `s`, or whatever `s` is if it is not a string.

def readPrecisely(file, l):

Undocumented

def _responseFromMessage(responseConstructor, message, **kwargs):

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

def _getDisplayableArguments(obj, alwaysShow, fieldNames):

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 _compactRepr(obj, alwaysShow=None, flagNames=None, fieldNames=None, sectionNames=None):

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`.

API Documentation for twisted, generated by pydoctor at 2020-03-25 17:34:30.

twisted.names.dns module documentation

`twisted.names.dns` module documentation