MFCHASH
mfcbp = &ipst->ips_mfcs[MFCHASH(mfccp->mfcc_origin.s_addr,
hash = MFCHASH(origin.s_addr, mcastgrp.s_addr);
mfcbp = &ipst->ips_mfcs[MFCHASH(src, dst)];
hash = MFCHASH(src, dst);
hash = MFCHASH(mfc_rt->mfc_origin.s_addr, mfc_rt->mfc_mcastgrp.s_addr);
mfcbp = &ipst->ips_mfcs[MFCHASH(req->src.s_addr, req->grp.s_addr)];