unix: add support for OpenBSD unveil(2)
Now as `SYS_UNVEIL` has landed in `x/sys`, it's time to have a convenient handle for it too.
Change-Id: I61db9cc23fa9f2e10bac601959002319ea9c854b
GitHub-Last-Rev: eb9487242e1fafa06c057ef49444ea5a711382df
GitHub-Pull-Request: golang/sys#19
Reviewed-on: https://go-review.googlesource.com/c/142317
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/unix/openbsd_unveil.go b/unix/openbsd_unveil.go
new file mode 100644
index 0000000..aebc2dc
--- /dev/null
+++ b/unix/openbsd_unveil.go
@@ -0,0 +1,44 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build openbsd
+
+package unix
+
+import (
+ "syscall"
+ "unsafe"
+)
+
+// Unveil implements the unveil syscall.
+// For more information see unveil(2).
+// Note that the special case of blocking further
+// unveil calls is handled by UnveilBlock.
+func Unveil(path string, flags string) error {
+ pathPtr, err := syscall.BytePtrFromString(path)
+ if err != nil {
+ return err
+ }
+ flagsPtr, err := syscall.BytePtrFromString(flags)
+ if err != nil {
+ return err
+ }
+ _, _, e := syscall.Syscall(SYS_UNVEIL, uintptr(unsafe.Pointer(pathPtr)), uintptr(unsafe.Pointer(flagsPtr)), 0)
+ if e != 0 {
+ return e
+ }
+ return nil
+}
+
+// UnveilBlock blocks future unveil calls.
+// For more information see unveil(2).
+func UnveilBlock() error {
+ // Both pointers must be nil.
+ var pathUnsafe, flagsUnsafe unsafe.Pointer
+ _, _, e := syscall.Syscall(SYS_UNVEIL, uintptr(pathUnsafe), uintptr(flagsUnsafe), 0)
+ if e != 0 {
+ return e
+ }
+ return nil
+}
