nf_log_register
int nf_log_register(u_int8_t pf, struct nf_logger *logger);
EXPORT_SYMBOL(nf_log_register);
ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
ret = nf_log_register(NFPROTO_ARP, &nf_arp_logger);
ret = nf_log_register(NFPROTO_IPV6, &nf_ip6_logger);
ret = nf_log_register(NFPROTO_NETDEV, &nf_netdev_logger);
ret = nf_log_register(NFPROTO_BRIDGE, &nf_bridge_logger);
status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);