1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package unix
6
7import (
8	"syscall"
9	"unsafe"
10)
11
12// Unveil implements the unveil syscall.
13// For more information see unveil(2).
14// Note that the special case of blocking further
15// unveil calls is handled by UnveilBlock.
16func Unveil(path string, flags string) error {
17	pathPtr, err := syscall.BytePtrFromString(path)
18	if err != nil {
19		return err
20	}
21	flagsPtr, err := syscall.BytePtrFromString(flags)
22	if err != nil {
23		return err
24	}
25	_, _, e := syscall.Syscall(SYS_UNVEIL, uintptr(unsafe.Pointer(pathPtr)), uintptr(unsafe.Pointer(flagsPtr)), 0)
26	if e != 0 {
27		return e
28	}
29	return nil
30}
31
32// UnveilBlock blocks future unveil calls.
33// For more information see unveil(2).
34func UnveilBlock() error {
35	// Both pointers must be nil.
36	var pathUnsafe, flagsUnsafe unsafe.Pointer
37	_, _, e := syscall.Syscall(SYS_UNVEIL, uintptr(pathUnsafe), uintptr(flagsUnsafe), 0)
38	if e != 0 {
39		return e
40	}
41	return nil
42}
43