DB_CKSUMSTUFF
DB_CKSUMSTUFF(mp1) = DB_CKSUMSTUFF(mp);
DB_CKSUMSTUFF(mp) = (uint8_t *)cksump - (uint8_t *)ip6h;
DB_CKSUMSTUFF(mp) = (uint8_t *)cksump - (uint8_t *)ipha;
*stuff = (uint32_t)DB_CKSUMSTUFF(mp);
DB_CKSUMSTUFF(mp) = (intptr_t)stuff;
DB_CKSUMSTUFF(dst) = DB_CKSUMSTUFF(src);
ocsum_stuff = (uint32_t)DB_CKSUMSTUFF(omp);
DB_CKSUMSTUFF(nhdrmp) = ocsum_stuff;
(uint32_t)DB_CKSUMSTUFF(mp);
DB_CKSUMSTUFF(nmp) = stuff_offset;
DB_CKSUMSTUFF(nmp) = stuff_offset;
DB_CKSUMSTUFF(nmp) = stuff_offset;
DB_CKSUMSTUFF(mp) = 0;