UDP_CHECKSUM_OFFSET
offset = hlen + UDP_CHECKSUM_OFFSET;
((uint16_t *)(((uchar_t *)(ipha)) + ((hlen) + UDP_CHECKSUM_OFFSET)))
hck_stuff += UDP_CHECKSUM_OFFSET;
cksum_off = UDP_CHECKSUM_OFFSET;
stuff = start + UDP_CHECKSUM_OFFSET;
stuff = (uint16_t *)(ptr + UDP_CHECKSUM_OFFSET);