ip_find_hdr_v4
extern int ip_find_hdr_v4(ipha_t *, ip_pkt_t *, boolean_t);
(void) ip_find_hdr_v4(ipha, &ipps, B_FALSE);
(void) ip_find_hdr_v4((ipha_t *)rptr, &ipp,
err = ip_find_hdr_v4(ipha, ipp, B_TRUE);
(void) ip_find_hdr_v4((ipha_t *)rptr, &ipp,
err = ip_find_hdr_v4((ipha_t *)rptr, &udp->udp_recv_ipp,
(void) ip_find_hdr_v4((ipha_t *)rptr, &ipps, B_FALSE);