find_rhc
gw_rhc = find_rhc(paddr, ire->ire_ipversion, B_FALSE);
attrp->igsa_rhc = find_rhc(paddr, ipversion, B_FALSE);
if ((rhc = find_rhc(addr, version, staleok)) == NULL)
extern tsol_tnrhc_t *find_rhc(const void *, uchar_t, boolean_t);