sub send_packet {
    my ($socket, $packet) = @_;
    
    my $length = length($packet);
    my $lengthbuf = pack("N", $length);
    my $rc = syswrite($socket, $lengthbuf, 4);
    die "syswrite (length): $!\n" if $rc != 4;

    my $byteswritten = 0;
    while ($byteswritten < $length) {
        my $rc = syswrite($socket, $packet, length($packet));
        die "SEND_PACKET: sysread (data): $!\n" if $rc < 0;

        $packet = substr($packet, $rc, -1);
        $byteswritten += $rc;
    }
}