npf_ifmap_register
if (ifname && (con->c_ifid = npf_ifmap_register(npf, ifname)) == 0) {
if (ifname && (ifid = npf_ifmap_register(npf, ifname)) == 0) {
u_int npf_ifmap_register(npf_t *, const char *);
if (ifname && (nt->nt_ifid = npf_ifmap_register(npf, ifname)) == 0) {
if ((rl->r_ifid = npf_ifmap_register(npf, rname)) == 0) {
npf_ifmap_register(npf, ifname);