mfc_find
rt = mfc_find(&mfccp->mfcc_origin, &mfccp->mfcc_mcastgrp);
rt = mfc_find(&mfccp->mfcc_origin, &mfccp->mfcc_mcastgrp);
rt = mfc_find(&ip->ip_src, &ip->ip_dst);
mfc = mfc_find(&req->bu_src, &req->bu_dst);
mfc = mfc_find(&req->bu_src, &req->bu_dst);
rt = mfc_find(&req->src, &req->grp);