npf_nat_setaddr
errno = npf_nat_setaddr(nt, AF_INET, &addr, 0);
errno = npf_nat_setaddr(nt, AF_INET, &addr, 0);
int npf_nat_setaddr(nl_nat_t *, int, npf_addr_t *, npf_netmask_t);
npf_nat_setaddr(nat, family, &am->fam_addr, am->fam_mask);