Provided by: libnet-dns-perl_1.10-2_all 
NAME
Net::DNS::Update - DNS dynamic update packet
SYNOPSIS
use Net::DNS;
$update = new Net::DNS::Update( 'example.com', 'IN' );
$update->push( prereq => 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 RFC2136 for dynamic update semantics.
METHODS
new
$update = new Net::DNS::Update;
$update = new Net::DNS::Update( 'example.com' );
$update = new Net::DNS::Update( '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. 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 = new Net::DNS::Update('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 $resolver = new Net::DNS::Resolver;
$resolver->nameservers('primary-master.example.com');
my $reply = $resolver->send($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: ', $resolver->errorstring, "\n";
}
Add an MX record for a name that already exists
my $update = new Net::DNS::Update('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 = new Net::DNS::Update('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 = new Net::DNS::Update('example.com');
$update->push( prereq => yxrrset('foo.example.com A') );
$update->push( update => rr_del('foo.example.com A') );
Delete all RRs for a name
my $update = new Net::DNS::Update('example.com');
$update->push( prereq => yxdomain('byebye.example.com') );
$update->push( update => rr_del('byebye.example.com') );
Perform a DNS update signed using a BIND private key file
my $update = new Net::DNS::Update('example.com');
$update->push( update => rr_add('foo.example.com A 10.1.2.3') );
$update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.private" );
my $reply = $resolver->send( $update );
$reply->verify( $update ) || die $reply->verifyerr;
Signing the DNS update using a BIND public key file
$update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.key" );
Signing the DNS update using a customised TSIG record
$update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.private",
fudge => 60
);
Another way to sign a DNS update
my $key_name = 'tsig-key';
my $key = 'awwLOtRfpGE+rRKF2+DEiw==';
my $tsig = new Net::DNS::RR("$key_name TSIG $key");
$tsig->fudge(60);
my $update = new Net::DNS::Update('example.com');
$update->push( update => rr_add('foo.example.com A 10.1.2.3') );
$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 above copyright notice
appear in all copies and that both that 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, Net::DNS, Net::DNS::Packet, Net::DNS::Header, Net::DNS::RR, Net::DNS::Resolver, RFC
2136, RFC 2845