Net::DNS::Update3pm
Dns dynamic update packet
Usage
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') );
Overview
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/perluse 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 );
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 );
Releases
15 releases since Debian 2.1 (Slink); the text changed 14 times.