if(type == ETH_P_IP && DATA(packet)[start + 9] == 6) {
start += (DATA(packet)[start] & 0xf) * 4;
} else if(type == ETH_P_IPV6 && DATA(packet)[start + 6] == 6) {
if(type == ETH_P_IP && DATA(packet)[start + 9] == 6) {
start += (DATA(packet)[start] & 0xf) * 4;
} else if(type == ETH_P_IPV6 && DATA(packet)[start + 6] == 6) {