haiku/headers/compatibility/bsd/sys/ioccom.h

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/**
* @file sys/ioccom.h
* @brief Definitions & maros common to ioctl
*/
#ifndef _SYS_IOCCOM_H
#define _SYS_IOCCOM_H
/**
* @defgroup IOCTL_common sys/ioccom.h
* @brief Definitions & maros common to ioctl()
* @ingroup OpenBeOS_POSIX
* @ingroup IOCTL
* Ioctl values passed as the command (2nd) variable have the
* command encoded in the lower word and the size of any parameters
* in the upper word (in or out).
* The high 3 bits are used to encode whether it's in or out.
* Due to this you can't just give an ioctl value, you need to encode
* it using macros described in
* @ref IOCTL_macros
* @{
*/
/** @defgroup IOCTL_parm ioctl() parameter definitions
* @ingroup IOCTL_common
* @{
*/
/** @def IOC_VOID */
#define IOC_VOID (ulong)0x20000000
/** @def IOC_OUT ioctl expects data (output) */
#define IOC_OUT (ulong)0x40000000
/** @def IOC_IN ioctl passes a value in */
#define IOC_IN (ulong)0x80000000
/** @def IOC_INOUT ioctl passes data in and out */
#define IOC_INOUT (IOC_IN|IOC_OUT)
/** @def IOC_DIRMASK */
#define IOC_DIRMASK (ulong)0xe0000000
/** @} */
/**
* @defgroup IOCTL_macros IOCTL macros
* These should be used to define the values passed in as cmd to
* ioctl()
* @ingroup IOCTL_common
* @{
*/
/** @def IOCPARM_MASK mask used to for following macros */
#define IOCPARM_MASK 0x1fff
/** @def IOCPARM_LEN(x) length of the data passed as param */
#define IOCPARM_LEN(x) (((x) >> 16) & IOCPARM_MASK)
/** @def IOCBASECMD(x) the base command encoded in the ioctl value */
#define IOCBASECMD(x) ((x) & ~(IOCPARM_MASK << 16))
/** @def IOCGROUP(x) which group of ioctl() commands does this belong to? */
#define IOCGROUP(x) (((x) >> 8) & 0xff)
/** @def IOCPARM_MAX Maximum size of parameter that can be passed (20 bytes) */
#define IOCPARM_MAX 20
/**
* @defgroup IOCTL_createmacros macro's to create ioctl() values
* @brief these macro's should be used to create new ioctl() values
* @ingroup IOCTL_common
* @{
*/
/** @def _IOC(inout, group, num , len) create a new ioctl */
#define _IOC(inout, group, num, len) \
(inout | ((len & IOCPARM_MASK)<<16) | ((group) << 8) | (num))
/** @def _IO(g,n) create a new void ioctl for group g, number n */
#define _IO(g,n) _IOC(IOC_VOID, (g), (n), 0)
/** @def _IOR(g,n,t) create a ioctl() that reads a value of type t*/
#define _IOR(g,n,t) _IOC(IOC_OUT, (g), (n), sizeof(t))
/** @def _IOW(g,n,t) ioctl() that writes value of type t, group g, number n */
#define _IOW(g,n,t) _IOC(IOC_IN , (g), (n), sizeof(t))
/** @def _IOWR(g,n,t) ioctl() that reads/writes value of type t
* @note this isn't _IORW as this causes name conflicts on some systems */
#define _IOWR(g,n,t) _IOC(IOC_INOUT, (g), (n), sizeof(t))
/** @} */
/** @} */
#endif /* _SYS_IOCCOM_H */