constants Module

The constants module defines the various DNS constants, and also provides some utility functions for dealing with these.

class constants.QR

Enumerates the possible QR bit values.

QUERY = 0

QR flag for queries

RESPONSE = 1

QR flag for responses

class constants.OpCode

Enumerates the defined DNS operation codes.

QUERY = 0

OpCode for queries

IQUERY = 1

OpCode for inverse queries

STATUS = 2

OpCode for status queries

NOTIFY = 4

OpCode for NOTIFY messages

UPDATE = 5

OpCode for UPDATE messages

DSO = 6

OpCode for DNS Stateful Operation (DSO) messages

class constants.RCODE

Enumerates the defined DNS response codes.

NoError = 0

No Error RCODE

FormErr = 1

Format Error RCODE

ServFail = 2

Server Failure RCODE

NXDomain = 3

Non-Existent Domain RCODE

NotImp = 4

Not Implemented RCODE

Refused = 5

Query Refused RCODE

YXDomain = 6

Name Exists when it should not RCODE

YXRRSet = 7

RR Set Exists when it should not RCODE

NXRRSet = 8

RR Set that should exist does not RCODE

NotAuth = 9

Server Not Authoritative for zone / Not Authorized RCODE

NotZone = 10

Name not contained in zone RCODE

DSOTYPENI = 11

DSO-TYPE Not Implemented RCODE

class constants.Type

Enumerates the defined DNS types.

A = 1

a host address RTYPE

NS = 2

an authoritative name server RTYPE

MD = 3

a mail destination RTYPE

MF = 4

a mail forwarder RTYPE

CNAME = 5

the canonical name for an alias RTYPE

SOA = 6

marks the start of a zone of authority RTYPE

MB = 7

a mailbox domain name RTYPE

MG = 8

a mail group member RTYPE

MR = 9

a mail rename domain name RTYPE

NULL = 10

a null RR RTYPE

WKS = 11

a well known service description RTYPE

PTR = 12

a domain name pointer RTYPE

HINFO = 13

host information RTYPE

MINFO = 14

mailbox or mail list information RTYPE

MX = 15

mail exchange RTYPE

TXT = 16

text strings RTYPE

RP = 17

for Responsible Person RTYPE

AFSDB = 18

for AFS Data Base location RTYPE

X25 = 19

for X.25 PSDN address RTYPE

ISDN = 20

for ISDN address RTYPE

RT = 21

for Route Through RTYPE

NSAP = 22

for NSAP address, NSAP style A record RTYPE

NSAP_PTR = 23

for domain name pointer, NSAP style RTYPE

SIG = 24

for security signature RTYPE

KEY = 25

for security key RTYPE

PX = 26

X.400 mail mapping information RTYPE

GPOS = 27

Geographical Position RTYPE

AAAA = 28

IP6 Address RTYPE

OPT = 41

OPT RTYPE

RRSIG = 46

RRSIG RTYPE

TSIG = 250

Transaction Signature

IXFR = 251

incremental transfer

AXFR = 252

transfer of an entire zone

constants.type_name(dns_type: int) → str

Converts a numeric type value to a name. This is the symbolic name if we know it (like NS or AAAA), otherwise the RFC 3597 version (TYPE####). Numbers out of range raise a ValueError exception.

Parameters:dns_type (str) – Numeric value of a DNS type to convert to string. Returns:String version of the type identifier. Return type:str Raises:ValueError if dns_type is not an unsigned 16-bit value.

class constants.Class

Enumerates the defined DNS classes.

IN = 1

Internet class

CH = 3

Chaos class

HS = 4

Hesiod class

NONE = 254

“NONE” class

ANY = 255

“ANY” class

constants.class_name(dns_class: int) → str

Converts a numeric class value to a name. This is the symbolic name if we know it (like IN or CH), otherwise the RFC 3597 version (CLASS####). Numbers out of range raise a ValueError exception.

Parameters:dns_class (str) – Numeric value of a DNS class to convert to string. Returns:String version of the class identifier. Return type:str Raises:ValueError if dns_class is not an unsigned 16-bit value.