__nf_register_net_hook
err = __nf_register_net_hook(net, NFPROTO_INET, reg);
err = __nf_register_net_hook(net, NFPROTO_IPV4, reg);
err = __nf_register_net_hook(net, NFPROTO_IPV6, reg);
err = __nf_register_net_hook(net, reg->pf, reg);