366 typedef struct	msgb {  struct
367 	struct	msgb	*b_next;  argument
368 	struct  msgb	*b_prev;  argument
369 	struct	msgb	*b_cont;  argument
370 	unsigned char	*b_rptr;
371 	unsigned char	*b_wptr;
372 	struct datab 	*b_datap;
373 	unsigned char	b_band;
374 	unsigned char	b_tag;
375 	unsigned short	b_flag;
376 	queue_t		*b_queue;	/* for sync queues */