extern void nfnetlink_set_err(u32 pid, u32 group, int error);
extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);
extern void nfnetlink_set_err(u32 pid, u32 group, int error);
extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);