if ($attrs{TP_PROTO} eq 'TCP+options') {
substr($tcp, 12, 2) = pack('n', (6 << 12) | 0x02 | 0x10);
$tcp .= pack('CCn', 2, 4, 1975); # MSS option
if ($attrs{TP_PROTO} eq 'TCP+options') {
substr($tcp, 12, 2) = pack('n', (6 << 12) | 0x02 | 0x10);
$tcp .= pack('CCn', 2, 4, 1975); # MSS option