sub register {
  my ($self, $qp) = @_;
  $self->register_hook("connect", "connect_handler");
  $self->register_hook("rcpt", "rcpt_handler");
  #$self->register_hook("disconnect", "disconnect_handler");
}

sub connect_handler {
  my ($self, $transaction) = @_;
  my $remote_ip = $self->qp->connection->remote_ip;

  my %dnsbl_zones = map { (split /\s+/, $_, 2)[0,1] } $self->qp->config('dnsbl_zones');
  return unless %dnsbl_zones;
  
  my $reversed_ip = join(".", reverse(split(/\./, $remote_ip)));

  # we should queue these lookups in the background and just fetch the
  # results in the first rcpt handler ... oh well.

  my $result = "";

  my $res = new Net::DNS::Resolver;
  for my $dnsbl (keys %dnsbl_zones) {
    $self->log(3, "Checking $reversed_ip.$dnsbl");
    my $query = $res->query("$reversed_ip.$dnsbl", "TXT");
    if ($query) {
      my $a_record = 0;
      foreach my $rr ($query->answer) {
	$a_record = 1 if $rr->type eq "A";
	next unless $rr->type eq "TXT";
	$self->log(10, "got txt record");
	$result = $rr->txtdata and last;
      }
      $a_record and $result = "Blocked by $dnsbl";
    }
    else {
      warn "$$ query for $reversed_ip.$dnsbl failed: ", $res->errorstring, "\n"
	unless $res->errorstring eq "NXDOMAIN";
    }
  }

  $transaction->notes('dnsbl', $result);

  return DECLINED;
}

sub rcpt_handler {
  my ($self, $transaction, $rcpt) = @_;
  my $note = $transaction->notes('rhsbl');
  return (DENY, $note) if $note;
  return DECLINED;
}

sub disconnect_handler {
  # if we queued stuff in the background we should make sure it got
  # cleaned up here.
  return DECLINED;
}


1;