Net::DNS::DomainName (3)

Leading comments

Automatically generated by Pod::Man 4.09 (Pod::Simple 3.35)

Standard preamble:
========================================================================

(The comments found at the beginning of the groff file "man3/Net::DNS::DomainName.3pm".)

NAME

Net::DNS::DomainName - DNS name representation

SYNOPSIS

    use Net::DNS::DomainName;

    $object = new Net::DNS::DomainName('example.com');
    $name = $object->name;
    $data = $object->encode;

    ( $object, $next ) = decode Net::DNS::DomainName( \$data, $offset );

DESCRIPTION

The Net::DNS::DomainName module implements the concrete representation of domain names used within packets.

Net::DNS::DomainName defines methods for encoding and decoding wire format octet strings as defined in

All other behaviour, including the new() constructor, is inherited from Net::DNS::Domain.

The Net::DNS::DomainName1035 and Net::DNS::DomainName2535 packages implement disjoint domain name subtypes which provide the name compression and canonicalisation specified by

and These are necessary to meet the backward compatibility requirements introduced by

METHODS

new

    $object = new Net::DNS::DomainName('example.com');

Creates a domain name object which identifies the domain specified by the character string argument.

canonical

    $data = $object->canonical;

Returns the canonical wire-format representation of the domain name as defined in

(8.1).

decode

    $object = decode Net::DNS::DomainName( \$buffer, $offset, $hash );

    ( $object, $next ) = decode Net::DNS::DomainName( \$buffer, $offset, $hash );

Creates a domain name object which represents the

domain name identified by the wire-format data at the indicated offset within the data buffer.

The argument list consists of a reference to a scalar containing the wire-format data and specified offset. The optional reference to a hash table provides improved efficiency of decoding compressed names by exploiting already cached compression pointers.

The returned offset value indicates the start of the next item in the data buffer.

encode

    $data = $object->encode;

Returns the wire-format representation of the domain name suitable for inclusion in a

packet buffer.

Net::DNS::DomainName1035

Net::DNS::DomainName1035 implements a subclass of domain name objects which are to be encoded using the compressed wire format defined in

    use Net::DNS::DomainName;

    $object = new Net::DNS::DomainName1035('compressible.example.com');
    $data   = $object->encode( $offset, $hash );

    ( $object, $next ) = decode Net::DNS::DomainName1035( \$data, $offset );

Note that

implies that the types defined in section 3.3 are the only types eligible for compression.

encode

    $data = $object->encode( $offset, $hash );

Returns the wire-format representation of the domain name suitable for inclusion in a

packet buffer.

The optional arguments are the offset within the packet data where the domain name is to be stored and a reference to a hash table used to index compressed names within the packet.

If the hash reference is undefined, encode() returns the lowercase uncompressed canonical representation defined in

(8.1).

Net::DNS::DomainName2535

Net::DNS::DomainName2535 implements a subclass of domain name objects which are to be encoded using uncompressed wire format.

Note that

and latterly specifies that the lower case canonical encoding defined in is to be used for types defined prior to

    use Net::DNS::DomainName;

    $object = new Net::DNS::DomainName2535('incompressible.example.com');
    $data   = $object->encode( $offset, $hash );

    ( $object, $next ) = decode Net::DNS::DomainName2535( \$data, $offset );

encode

    $data = $object->encode( $offset, $hash );

Returns the uncompressed wire-format representation of the domain name suitable for inclusion in a

packet buffer.

If the hash reference is undefined, encode() returns the lowercase canonical form defined in

(8.1).

COPYRIGHT

Copyright (c)2009-2011 Dick Franks.

All rights reserved.

This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

perl, Net::DNS, Net::DNS::Domain,