extern int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen);
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
extern int sk_chk_filter(struct sock_filter *filter, int flen);
extern int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen);
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
extern int sk_chk_filter(struct sock_filter *filter, int flen);