extern struct sfb *sfb_alloc(struct ifnet *, u_int32_t, u_int32_t, u_int32_t);
extern void sfb_destroy(struct sfb *);
extern int sfb_addq(struct sfb *, class_queue_t *, pktsched_pkt_t *,
extern struct sfb *sfb_alloc(struct ifnet *, u_int32_t, u_int32_t, u_int32_t);
extern void sfb_destroy(struct sfb *);
extern int sfb_addq(struct sfb *, class_queue_t *, pktsched_pkt_t *,