headers/compatibility/bsd/sys/ioccom.h

   1 /**
   2  * @file sys/ioccom.h
   3  * @brief Definitions & maros common to ioctl
   4  */
   5
   6 #ifndef _SYS_IOCCOM_H
   7 #define _SYS_IOCCOM_H
   8
   9
  10 #ifdef _BSD_SOURCE
  11
  12
  13 /**
  14  * @defgroup IOCTL_common sys/ioccom.h
  15  * @brief Definitions & maros common to ioctl()
  16  * @ingroup OpenBeOS_POSIX
  17  * @ingroup IOCTL
  18  * Ioctl values passed as the command (2nd) variable have the
  19  * command encoded in the lower word and the size of any parameters
  20  * in the upper word (in or out).
  21  * The high 3 bits are used to encode whether it's in or out.
  22  * Due to this you can't just give an ioctl value, you need to encode
  23  * it using macros described in
  24  * @ref IOCTL_macros
  25  * @{
  26  */
  27
  28 /** @defgroup IOCTL_parm ioctl() parameter definitions
  29  * @ingroup IOCTL_common
  30  * @{
  31  */
  32 /** @def IOC_VOID */
  33 #define IOC_VOID         (ulong)0x20000000
  34 /** @def IOC_OUT ioctl expects data (output) */
  35 #define IOC_OUT          (ulong)0x40000000
  36 /** @def IOC_IN ioctl passes a value in */
  37 #define IOC_IN           (ulong)0x80000000
  38 /** @def IOC_INOUT ioctl passes data in and out */
  39 #define IOC_INOUT        (IOC_IN|IOC_OUT)
  40 /** @def IOC_DIRMASK */
  41 #define IOC_DIRMASK      (ulong)0xe0000000
  42 /** @} */
  43
  44 /**
  45  * @defgroup IOCTL_macros IOCTL macros
  46  * These should be used to define the values passed in as cmd to
  47  * ioctl()
  48  * @ingroup IOCTL_common
  49  * @{
  50  */
  51 /** @def IOCPARM_MASK mask used to for following macros */
  52 #define IOCPARM_MASK     0x1fff
  53 /** @def IOCPARM_LEN(x) length of the data passed as param */
  54 #define IOCPARM_LEN(x)   (((x) >> 16) & IOCPARM_MASK)
  55 /** @def IOCBASECMD(x) the base command encoded in the ioctl value */
  56 #define IOCBASECMD(x)    ((x) & ~(IOCPARM_MASK << 16))
  57 /** @def IOCGROUP(x) which group of ioctl() commands does this belong to? */
  58 #define IOCGROUP(x)      (((x) >> 8) & 0xff)
  59 /** @def IOCPARM_MAX Maximum size of parameter that can be passed (20 bytes) */
  60 #define IOCPARM_MAX      20
  61
  62 /**
  63  * @defgroup IOCTL_createmacros macro's to create ioctl() values
  64  * @brief these macro's should be used to create new ioctl() values
  65  * @ingroup IOCTL_common
  66  * @{
  67  */
  68 /** @def _IOC(inout, group, num , len) create a new ioctl */
  69 #define _IOC(inout, group, num, len) \
  70         (inout | ((len & IOCPARM_MASK)<<16) | ((group) << 8) | (num))
  71 /** @def _IO(g,n) create a new void ioctl for group g, number n */
  72 #define _IO(g,n)          _IOC(IOC_VOID, (g), (n), 0)
  73 /** @def _IOR(g,n,t) create a ioctl() that reads a value of type t*/
  74 #define _IOR(g,n,t)       _IOC(IOC_OUT,  (g), (n), sizeof(t))
  75 /** @def _IOW(g,n,t) ioctl() that writes value of type t, group g, number n */
  76 #define _IOW(g,n,t)       _IOC(IOC_IN ,  (g), (n), sizeof(t))
  77 /** @def _IOWR(g,n,t) ioctl() that reads/writes value of type t
  78  * @note this isn't _IORW as this causes name conflicts on some systems */
  79 #define _IOWR(g,n,t)      _IOC(IOC_INOUT,  (g), (n), sizeof(t))
  80 /** @} */
  81
  82 /** @} */
  83
  84
  85 #endif
  86
  87
  88 #endif /* _SYS_IOCCOM_H */