sub register {
  my ($self, $qp) = @_;
  $self->register_hook("queue", "queue_handler");
}

sub queue_handler {
  my ($self, $transaction) = @_;

  # these bits inspired by Peter Samuels "qmail-queue wrapper"
  pipe(MESSAGE_READER, MESSAGE_WRITER) or fault("Could not create message pipe"), exit;
  pipe(ENVELOPE_READER, ENVELOPE_WRITER) or fault("Could not create envelope pipe"), exit;

  my $child = fork();

  not defined $child and fault(451, "Could not fork"), exit;

  if ($child) {
    # Parent
    my $oldfh = select(MESSAGE_WRITER); $| = 1; 
                select(ENVELOPE_WRITER); $| = 1;
    select($oldfh);

    close MESSAGE_READER  or fault("close msg reader fault"),exit;
    close ENVELOPE_READER or fault("close envelope reader fault"), exit;

    $transaction->header->print(\*MESSAGE_WRITER);
    $transaction->body_resetpos;
    while (my $line = $transaction->body_getline) {
      print MESSAGE_WRITER $line;
    }
    close MESSAGE_WRITER;

    my @rcpt = map { "T" . $_->address } $transaction->recipients;
    my $from = "F".($transaction->sender->address|| "" );
    print ENVELOPE_WRITER "$from\0", join("\0",@rcpt), "\0\0"
      or return(DECLINED,"Could not print addresses to queue");
    
    close ENVELOPE_WRITER;
    waitpid($child, 0);
    my $exit_code = $? >> 8;
    $exit_code and return(DECLINED, "Unable to queue message ($exit_code)");
    return (OK, "Queued!");
  }
  elsif (defined $child) {
    # Child
    close MESSAGE_WRITER or die "could not close message writer in parent";
    close ENVELOPE_WRITER or die "could not close envelope writer in parent";
    
    open(STDIN, "<&MESSAGE_READER") or die "b1";
    open(STDOUT, "<&ENVELOPE_READER") or die "b2";
    
    unless (exec '/var/qmail/bin/qmail-queue') {
      return (DECLINED, "fatal error spawning qmail-queue");
    }
  }
}