fix: populate ldns submodule and add autotools to LDNS build stage

- Re-cloned zonemaster-ldns with --recurse-submodules so the bundled
  ldns C library source (including Changelog and configure.ac) is present
- Added autoconf, automake, libtool to Dockerfile.backend ldns-build stage
  so libtoolize + autoreconf can generate ldns/configure during make

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

zonemaster-ldns/ldns/contrib/DNS-LDNS/lib/DNS/LDNS/Packet.pm

@@ -0,0 +1,259 @@
+package DNS::LDNS::Packet;
+
+use 5.008008;
+use strict;
+use warnings;
+
+use DNS::LDNS;
+
+our $VERSION = '0.61';
+
+sub new {
+    my ($class, %args) = @_;
+
+    if ($args{name}) {
+	return _query_new(
+	    $args{name}, $args{type}, $args{class}, $args{flags});
+    }
+    else {
+	return _new;
+    }
+}
+
+sub question {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_question, $self);
+}
+
+sub set_question {
+    my ($self, $l) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->question);
+    $self->_set_question($l);
+    return DNS::LDNS::GC::own($l, $self);
+}
+
+sub answer {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_answer, $self);
+}
+
+sub set_answer {
+    my ($self, $l) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->answer);
+    $self->_set_answer($l);
+    return DNS::LDNS::GC::own($l, $self);
+}
+
+sub authority {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_authority, $self);
+}
+
+sub set_authority {
+    my ($self, $l) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->authority);
+    $self->_set_authority($l);
+    return DNS::LDNS::GC::own($l, $self);
+}
+
+sub additional {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_additional, $self);
+}
+
+sub set_additional {
+    my ($self, $l) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->additional);
+    $self->_set_additional($l);
+    return DNS::LDNS::GC::own($l, $self);
+}
+
+sub answerfrom {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_answerfrom, $self);
+}
+
+sub set_answerfrom {
+    my ($self, $a) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->answerfrom);
+    $self->_set_answerfrom($a);
+    return DNS::LDNS::GC::own($a, $self);
+}
+
+
+sub timestamp {
+    my $self = shift;
+    my $t = _timestamp($self);
+    return wantarray ? @$t : $t;
+}
+
+sub edns_data {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_edns_data, $self);
+}
+
+sub set_edns_data {
+    my ($self, $data) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->edns_data);
+    $self->_set_edns_data($data);
+    return DNS::LDNS::GC::own($data, $self);
+}
+
+sub push_rr {
+    my ($self, $sec, $rr) = @_;
+
+    my $ret = $self->_push_rr($sec, my $copy = $_->clone);
+    DNS::LDNS::GC::own($copy, $self);
+    return $ret;
+}
+
+sub safe_push_rr {
+    my ($self, $sec, $rr) = @_;
+
+    my $ret = $self->_safe_push_rr($sec, my $copy = $_->clone);
+    if ($ret) {
+	DNS::LDNS::GC::own($copy, $self);
+    }
+    return $ret;
+}
+
+sub tsig {
+    my $self = shift;
+    return DNS::LDNS::GC::own($self->_tsig, $self);
+}
+
+sub set_tsig {
+    my ($self, $rr) = @_;
+    DNS::LDNS::GC::disown(my $old = $self->tsig);
+    $self->_set_tsig($rr);
+    return DNS::LDNS::GC::own($rr, $self);
+}
+
+sub DESTROY {
+    DNS::LDNS::GC::free($_[0]);
+}
+
+1;
+__END__
+
+=head1 NAME
+
+DNS::LDNS::Packet - DNS packet
+
+=head1 SYNOPSIS
+
+  use DNS::LDNS ':all'
+
+  my pkt = new DNS::LDNS::Packet(name => rdata, type => LDNS_RR_TYPE_...,
+    class => LDNS_RR_CLASS_..., flags => ...)
+  my pkt = new DNS::LDNS::Packet
+
+  pkt2 = pkt->clone
+
+  pkt->to_string
+
+  rrlist = pkt->question
+  pkt->set_question(rrlist)
+'
+  rrlist = pkt->answer
+  pkt->set_answer(rrlist)
+
+  rrlist = pkt->authority
+  pkt->set_authority(rrlist)
+
+  rrlist = pkt->additional
+  pkt->set_additional(rrlist)
+
+  rrlist = pkt->all
+  rrlist = pkt->all_noquestion
+
+  for (qw/qr aa tc rd cd ra ad/) {
+    bool = pkt->$_
+    pkt->set_$_(bool)
+  }
+
+  id = pkt->id
+  pkt->set_id(id)
+  pkt->set_random_id
+
+  count = pkt->qdcount
+  count = pkt->ancount
+  count = pkt->nscount
+  count = pkt->arcount
+
+  opcode = pkt->opcode
+  pkt->set_opcode(opcode)
+
+  rcode = pkt->rcode                  # Response code
+  pkt->set_rcode(rcode)
+
+  size = pkt->size
+
+  epoch = pkt->querytime
+  pkt->set_querytime(epoch)
+
+  rdata = pkt->answerfrom
+  pkt->set_answerfrom(rdata)
+
+  (sec, usec) = pkt->timestamp
+  pkt->set_timestamp(sec, usec)
+
+  bool = pkt->edns
+
+  size = pkt->edns_udp_size
+  pkt->set_edns_udp_size(size)
+
+  rcode = pkt->edns_extended_rcode
+  pkt->set_edns_extended_rcode(rcode)
+
+  v = pkt->edns_version
+  pkt->set_edns_version(v)
+
+  z = pkt->edns_z
+  pkt->set_edns_z(z)
+
+  do = pkt->edns_do
+  pkt->set_edns_do(do)
+
+  rdata = pkt->edns_data
+  pkt->set_edns_data(rdata)
+
+  pkt->set_flags(flags)
+
+  rrlist = pkt->rr_list_by_name(rdata, section)
+  rrlist = pkt->rr_list_by_type(type, section)
+  rrlist = pkt->rr_list_by_name_and_type(rdata, type, section)
+
+  bool = pkt->rr(section, rr)       # Check if rr exists
+
+  pkt->push_rr(section, rr)
+  pkt->safe_push_rr(section, rr)
+
+  count = pkt->section_count(section)
+  bool = pkt->empty
+
+  rr = pkt->tsig
+  pkt->set_tsig(rr)
+
+  type = pkt->reply_type
+
+  rrlist = pkt->get_rrsigs_for_name_and_type(rdata, rrtype)
+  rrlist = pkt->get_rrsigs_for_type(rrtype)
+
+=head1 SEE ALSO
+
+http://www.nlnetlabs.nl/projects/ldns
+
+=head1 AUTHOR
+
+Erik Pihl Ostlyngen, E<lt>erik.ostlyngen@uninett.noE<gt>
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright (C) 2013 by UNINETT Norid AS
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself, either Perl version 5.14.2 or,
+at your option, any later version of Perl 5 you may have available.
+
+=cut