Net::DNS::Update(3) User Contributed Perl Documentation Net::DNS::Update(3)
NAME
Net::DNS::Update - DNS dynamic update packet
SYNOPSIS
use Net::DNS;
$update = Net::DNS::Update->new( 'example.com', 'IN' );
$update->push( prereq => nxrrset('host.example.com. AAAA') );
$update->push( update => rr_add('host.example.com. 86400 AAAA 2001::DB8::F00') );
DESCRIPTION
Net::DNS::Update is a subclass of Net::DNS::Packet, to be used for
making DNS dynamic updates.
Programmers should refer to RFC2136 for dynamic update semantics.
METHODS
new
$update = Net::DNS::Update->new;
$update = Net::DNS::Update->new( 'example.com' );
$update = Net::DNS::Update->new( 'example.com', 'IN' );
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 and
update sections before performing the update.
Arguments are the zone name and the class. The zone and class may be
undefined or omitted and default to the default domain from the
resolver configuration and IN respectively.
push
$ancount = $update->push( prereq => $rr );
$nscount = $update->push( update => $rr );
$arcount = $update->push( additional => $rr );
$nscount = $update->push( update => $rr1, $rr2, $rr3 );
$nscount = $update->push( update => @rr );
Adds RRs to the specified section of the update packet.
Returns the number of resource records in the specified section.
Section names may be abbreviated to the first three characters.
unique_push
$ancount = $update->unique_push( prereq => $rr );
$nscount = $update->unique_push( update => $rr );
$arcount = $update->unique_push( additional => $rr );
$nscount = $update->unique_push( update => $rr1, $rr2, $rr3 );
$nscount = $update->unique_push( update => @rr );
Adds RRs to the specified section of the update packet provided that
the RRs are not already present in the same section.
Returns the number of resource records in the specified section.
Section names may be abbreviated to the first three characters.
EXAMPLES
The first example below shows a complete program. Subsequent examples
show only the creation of the update packet.
Although the examples are presented using the string form of RRs, the
corresponding ( name => value ) form may also be used.
Add a new host
#!/usr/bin/perl
use Net::DNS;
# Create the update packet.
my $update = Net::DNS::Update->new('example.com');
# Prerequisite is that no address records exist for the name.
$update->push( pre => nxrrset('host.example.com. A') );
$update->push( pre => nxrrset('host.example.com. AAAA') );
# Add two address records for the name.
$update->push( update => rr_add('host.example.com. 86400 A 192.0.2.1') );
$update->push( update => rr_add('host.example.com. 86400 AAAA 2001:DB8::1') );
# Send the update to the zone's primary nameserver.
my $resolver = Net::DNS::Resolver->new();
$resolver->nameservers('DNSprimary.example.com');
my $reply = $resolver->send($update);
# Did it work?
if ($reply) {
print 'Update RCODE: ', $reply->header->rcode, "\n";
} else {
print 'Update failed: ', $resolver->errorstring, "\n";
}
Add an MX record for a name that already exists
my $update = Net::DNS::Update->new('example.com');
$update->push( prereq => yxdomain('example.com') );
$update->push( update => rr_add('example.com MX 10 mailhost.example.com') );
Add a TXT record for a name that does not exist
my $update = Net::DNS::Update->new('example.com');
$update->push( prereq => 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( prereq => yxrrset('host.example.com A') );
$update->push( update => rr_del('host.example.com A') );
Delete all RRs for a name
my $update = Net::DNS::Update->new('example.com');
$update->push( prereq => yxdomain('byebye.example.com') );
$update->push( update => rr_del('byebye.example.com') );
Perform DNS update signed using a key generated by BIND tsig-keygen
my $update = Net::DNS::Update->new('example.com');
$update->push( update => rr_add('host.example.com AAAA 2001:DB8::1') );
$update->sign_tsig( $key_file );
my $reply = $resolver->send( $update );
$reply->verify( $update ) || die $reply->verifyerr;
Signing the DNS update using a customised TSIG record
$update->sign_tsig( $key_file, fudge => 60 );
Signing the DNS update using private key generated by BIND dnssec-keygen
$update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.private" );
Signing the DNS update using public key generated by BIND dnssec-keygen
$update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.key" );
Another way to sign a DNS update
use Net::DNS::RR::TSIG;
my $tsig = create Net::DNS::RR::TSIG( $key_file );
$tsig->fudge(60);
my $update = Net::DNS::Update->new('example.com');
$update->push( update => rr_add('host.example.com AAAA 2001:DB8::1') );
$update->push( additional => $tsig );
COPYRIGHT
Copyright (c)1997-2000 Michael Fuhr.
Portions Copyright (c)2002,2003 Chris Reinhardt.
Portions Copyright (c)2015 Dick Franks.
All rights reserved.
LICENSE
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the original copyright notices appear in all copies and
that both copyright notice and this permission notice appear in
supporting documentation, and that the name of the author not be used
in advertising or publicity pertaining to distribution of the software
without specific prior written permission.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
SEE ALSO
perl(1), Net::DNS(3), Net::DNS::Packet(3), Net::DNS::Header(3),
Net::DNS::RR(3), Net::DNS::Resolver(3),
RFC2136 <https://iana.org/go/rfc2136>,
RFC8945 <https://iana.org/go/rfc8945>
perl v5.34.3 2025-02-22 Net::DNS::Update(3)
net-dns 1.500.0 - Generated Mon Feb 24 18:35:34 CST 2025