Net::DNS::Update(3)

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

SYNOPSIS
    use Net::DNS::Update;

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

    $update->push(prerequisite => nxrrset('foo.example.com. A'));
    $update->push(update => rr_add('foo.example.com. 86400 A 192.168.1.2'));

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.

METHODS

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

Returns a "Net::DNS::Update" object used to perform a DNS dynamic update operation. Specifically, it creates a packet with the header opcode set to UPDATE and zone qtype to SOA (per RFC 2136, 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 strict;
    use Net::DNS;

    # Create the update packet.
    my $update = Net::DNS::Update->new('example.com');

    # Prerequisite is that no A records exist for the name.
    $update->push(prerequisite => 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) {
        my $rcode = $reply->header->rcode;
        print 'Update ', $rcode eq 'NOERROR' ? "succeeded\n" : "failed: $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(prerequisite => 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(prerequisite => 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(prerequisite => 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(prerequisite => yxdomain('byebye.example.com'));
    $update->push(update       => rr_del('byebye.example.com'));

  Perform a signed update
    my $key_name = 'tsig-key';
    my $key_data = '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_data);

  Another way to perform a signed update
    my $key_name = 'tsig-key';
    my $key_data = '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_data"));

  Perform a signed update with a customized TSIG record
    my $key_name = 'tsig-key';
    my $key_data = 'awwLOtRfpGE+rRKF2+DEiw==';

    my $tsig = Net::DNS::RR->new("$key_name TSIG $key_data");
    $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
WARNING: 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, Net::DNS, Net::DNS::Resolver, Net::DNS::Header, Net::DNS::Packet, Net::DNS::Question, Net::DNS::RR, RFC 2136, RFC 2845