Content-type: text/html Man page of Net::DNS::Update

Net::DNS::Update

Section: User Contributed Perl Documentation (3pm)
Updated: 2006-03-31
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NAME

Net::DNS::Update - Create a DNS update packet  

SYNOPSIS

"use Net::DNS::Update;"  

DESCRIPTION

"Net::DNS::Update" is a subclass of "Net::DNS::Packet", to be used for making DNS dynamic updates. Programmers should refer to RFC 2136 for the semantics of dynamic updates.

WARNING: This code is still under development. Please use with caution on production nameservers.  

METHODS

 

new

    $packet = Net::DNS::Update->new;
    $packet = Net::DNS::Update->new('example.com');
    $packet = Net::DNS::Update->new('example.com', 'HS');

Returns a "Net::DNS::Update" object suitable for performing a DNS dynamic update. Specifically, it creates a packet with the header opcode set to UPDATE and the zone record type to SOA (per RFC 2136, Section 2.3).

Programs must use the "push" method to add RRs to the prerequisite, update, and additional sections before performing the update.

Arguments are the zone name and the class. If the zone is omitted, the default domain will be taken from the resolver configuration. If the class is omitted, it defaults to IN.

Future versions of "Net::DNS" may provide a simpler interface for making dynamic updates.  

EXAMPLES

The first example below shows a complete program; subsequent examples show only the creation of the update packet.  

Add a new host

 #!/usr/bin/perl -w
 
 use Net::DNS;
 use strict;
 
 # Create the update packet.
 my $update = Net::DNS::Update->new('example.com');
 
 # Prerequisite is that no A records exist for the name.
 $update->push(pre => nxrrset('foo.example.com. A'));
 
 # Add two A records for the name.
 $update->push(update => rr_add('foo.example.com. 86400 A 192.168.1.2'));
 $update->push(update => rr_add('foo.example.com. 86400 A 172.16.3.4'));
 
 # Send the update to the zone's primary master.
 my $res = Net::DNS::Resolver->new;
 $res->nameservers('primary-master.example.com');
 
 my $reply = $res->send($update);
 
 # Did it work?
 if ($reply) {
     if ($reply->header->rcode eq 'NOERROR') {
         print "Update succeeded\n";
     } else {
         print 'Update failed: ', $reply->header->rcode, "\n";
     }
 } else {
     print 'Update failed: ', $res->errorstring, "\n";
 }

 

Add an MX record for a name that already exists

    my $update = Net::DNS::Update->new('example.com');
    $update->push(pre    => yxdomain('example.com'));
    $update->push(update => rr_add('example.com MX 10 mailhost.example.com'));

 

Add a TXT record for a name that doesn't exist

    my $update = Net::DNS::Update->new('example.com');
    $update->push(pre    => nxdomain('info.example.com'));
    $update->push(update => rr_add('info.example.com TXT "yabba dabba doo"'));

 

Delete all A records for a name

    my $update = Net::DNS::Update->new('example.com');
    $update->push(pre    => yxrrset('foo.example.com A'));
    $update->push(update => rr_del('foo.example.com A'));

 

Delete all RRs for a name

    my $update = Net::DNS::Update->new('example.com');
    $update->push(pre    => yxdomain('byebye.example.com'));
    $update->push(update => rr_del('byebye.example.com'));

 

Perform a signed update

    my $key_name = 'tsig-key';
    my $key      = 'awwLOtRfpGE+rRKF2+DEiw==';

    my $update = Net::DNS::Update->new('example.com');
    $update->push(update => rr_add('foo.example.com A 10.1.2.3'));
    $update->push(update => rr_add('bar.example.com A 10.4.5.6'));
    $update->sign_tsig($key_name, $key);

 

Another way to perform a signed update

    my $key_name = 'tsig-key';
    my $key      = 'awwLOtRfpGE+rRKF2+DEiw==';

    my $update = Net::DNS::Update->new('example.com');
    $update->push(update     => rr_add('foo.example.com A 10.1.2.3'));
    $update->push(update     => rr_add('bar.example.com A 10.4.5.6'));
    $update->push(additional => Net::DNS::RR->new("$key_name TSIG $key"));

 

Perform a signed update with a customized TSIG record

    my $key_name = 'tsig-key';
    my $key      = 'awwLOtRfpGE+rRKF2+DEiw==';

    my $tsig = Net::DNS::RR->new("$key_name TSIG $key");
    $tsig->fudge(60);

    my $update = Net::DNS::Update->new('example.com');
    $update->push(update     => rr_add('foo.example.com A 10.1.2.3'));
    $update->push(update     => rr_add('bar.example.com A 10.4.5.6'));
    $update->push(additional => $tsig);

 

BUGS

This code is still under development. Please use with caution on production nameservers.  

COPYRIGHT

Copyright (c) 1997-2002 Michael Fuhr.

Portions Copyright (c) 2002-2004 Chris Reinhardt.

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(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Header, Net::DNS::Packet, Net::DNS::Question, Net::DNS::RR, RFC 2136, RFC 2845


 

Index

NAME
SYNOPSIS
DESCRIPTION
METHODS
new
EXAMPLES
Add a new host
Add an MX record for a name that already exists
Add a TXT record for a name that doesn't exist
Delete all A records for a name
Delete all RRs for a name
Perform a signed update
Another way to perform a signed update
Perform a signed update with a customized TSIG record
BUGS
COPYRIGHT
SEE ALSO

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Time: 04:14:17 GMT, September 24, 2010