pf_threshold
void pf_init_threshold(struct pf_threshold *, u_int32_t,
void pf_add_threshold(struct pf_threshold *);
int pf_check_threshold(struct pf_threshold *);
pf_init_threshold(struct pf_threshold *threshold,
pf_add_threshold(struct pf_threshold *threshold)
pf_check_threshold(struct pf_threshold *threshold)
struct pf_threshold conn_rate;