cloudinit/vendor/github.com/vtolstov/go-ioctl/ioctl.go

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package ioctl
import "syscall"
// Generic ioctl constants
const (
IOC_NONE = 0x0
IOC_WRITE = 0x1
IOC_READ = 0x2
IOC_NRBITS = 8
IOC_TYPEBITS = 8
IOC_SIZEBITS = 14
IOC_DIRBITS = 2
IOC_NRSHIFT = 0
IOC_TYPESHIFT = IOC_NRSHIFT + IOC_NRBITS
IOC_SIZESHIFT = IOC_TYPESHIFT + IOC_TYPEBITS
IOC_DIRSHIFT = IOC_SIZESHIFT + IOC_SIZEBITS
IOC_NRMASK = ((1 << IOC_NRBITS) - 1)
IOC_TYPEMASK = ((1 << IOC_TYPEBITS) - 1)
IOC_SIZEMASK = ((1 << IOC_SIZEBITS) - 1)
IOC_DIRMASK = ((1 << IOC_DIRBITS) - 1)
)
// Some useful additional ioctl constanst
const (
IOC_IN = IOC_WRITE << IOC_DIRSHIFT
IOC_OUT = IOC_READ << IOC_DIRSHIFT
IOC_INOUT = (IOC_WRITE | IOC_READ) << IOC_DIRSHIFT
IOCSIZE_MASK = IOC_SIZEMASK << IOC_SIZESHIFT
IOCSIZE_SHIFT = IOC_SIZESHIFT
)
// IOC generate IOC
func IOC(dir, t, nr, size uintptr) uintptr {
return (dir << IOC_DIRSHIFT) | (t << IOC_TYPESHIFT) |
(nr << IOC_NRSHIFT) | (size << IOC_SIZESHIFT)
}
// IOR generate IOR
func IOR(t, nr, size uintptr) uintptr {
return IOC(IOC_READ, t, nr, size)
}
// IOW generate IOW
func IOW(t, nr, size uintptr) uintptr {
return IOC(IOC_WRITE, t, nr, size)
}
// IOWR generate IOWR
func IOWR(t, nr, size uintptr) uintptr {
return IOC(IOC_READ|IOC_WRITE, t, nr, size)
}
// IO generate IO
func IO(t, nr uintptr) uintptr {
return IOC(IOC_NONE, t, nr, 0)
}
// IOCTL send ioctl
func IOCTL(fd, name, data uintptr) error {
_, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, name, data)
if err != 0 {
return syscall.Errno(err)
}
return nil
}