IOCPARM_MASK       44 sys/ioccom.h   #define	IOCPARM_LEN(x)	(((x) >> 16) & IOCPARM_MASK)
IOCPARM_MASK       45 sys/ioccom.h   #define	IOCBASECMD(x)	((x) & ~(IOCPARM_MASK << 16))
IOCPARM_MASK       61 sys/ioccom.h   	(inout | ((len & IOCPARM_MASK) << 16) | ((group) << 8) | (num))