Add ioctl package

pkg/ioctl/README.md

@@ -0,0 +1,3 @@
+# IOCTL
+
+This is just an example how Linux IOCTL constants works.

pkg/ioctl/ioctl.go

@@ -0,0 +1,28 @@
+package ioctl
+
+import (
+	"bytes"
+)
+
+func Str(b []byte) string {
+	if i := bytes.IndexByte(b, 0); i >= 0 {
+		return string(b[:i])
+	}
+	return string(b)
+}
+
+func io(mode byte, type_ byte, number byte, size uint16) uintptr {
+	return uintptr(mode)<<30 | uintptr(size)<<16 | uintptr(type_)<<8 | uintptr(number)
+}
+
+func IOR(type_ byte, number byte, size uint16) uintptr {
+	return io(read, type_, number, size)
+}
+
+func IOW(type_ byte, number byte, size uint16) uintptr {
+	return io(write, type_, number, size)
+}
+
+func IORW(type_ byte, number byte, size uint16) uintptr {
+	return io(read|write, type_, number, size)
+}

pkg/ioctl/ioctl_be.go

@@ -0,0 +1,8 @@
+//go:build arm || arm64 || 386 || amd64
+
+package ioctl
+
+const (
+	write = 1
+	read  = 2
+)

pkg/ioctl/ioctl_le.go

@@ -0,0 +1,8 @@
+//go:build mipsle
+
+package ioctl
+
+const (
+	read  = 1
+	write = 2
+)

pkg/ioctl/ioctl_linux.go

@@ -0,0 +1,14 @@
+package ioctl
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func Ioctl(fd int, req uint, arg unsafe.Pointer) error {
+	_, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
+	if err != 0 {
+		return err
+	}
+	return nil
+}

pkg/ioctl/ioctl_test.go

@@ -0,0 +1,16 @@
+package ioctl
+
+import (
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIOR(t *testing.T) {
+	// #define SNDRV_PCM_IOCTL_INFO		_IOR('A', 0x01, struct snd_pcm_info)
+	if runtime.GOARCH == "arm64" {
+		c := IOR('A', 0x01, 288)
+		require.Equal(t, uintptr(0x81204101), c)
+	}
+}