// Copyright 2016 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 // +build 386 amd64 arm package unix import ( "errors" "fmt" "strconv" "syscall" "unsafe" ) const ( _SYS_PLEDGE = 108 ) // Pledge implements the pledge syscall. // // The pledge syscall does not accept execpromises on OpenBSD releases // before 6.3. // // execpromises must be empty when Pledge is called on OpenBSD // releases predating 6.3, otherwise an error will be returned. // // For more information see pledge(2). func Pledge(promises, execpromises string) error { maj, min, err := majmin() if err != nil { return err } // If OpenBSD <= 5.9, pledge is not available. if (maj == 5 && min != 9) || maj < 5 { return fmt.Errorf("pledge syscall is not available on OpenBSD %d.%d", maj, min) } // If OpenBSD <= 6.2 and execpromises is not empty // return an error - execpromises is not available before 6.3 if (maj < 6 || (maj == 6 && min <= 2)) && execpromises != "" { return fmt.Errorf("cannot use execpromises on OpenBSD %d.%d", maj, min) } pptr, err := syscall.BytePtrFromString(promises) if err != nil { return err } // This variable will hold either a nil unsafe.Pointer or // an unsafe.Pointer to a string (execpromises). var expr unsafe.Pointer // If we're running on OpenBSD > 6.2, pass execpromises to the syscall. if maj > 6 || (maj == 6 && min > 2) { exptr, err := syscall.BytePtrFromString(execpromises) if err != nil { return err } expr = unsafe.Pointer(exptr) } _, _, e := syscall.Syscall(_SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0) if e != 0 { return e } return nil } // majmin returns major and minor version number for an OpenBSD system. func majmin() (major int, minor int, err error) { var v Utsname err = Uname(&v) if err != nil { return } major, err = strconv.Atoi(string(v.Release[0])) if err != nil { err = errors.New("cannot parse major version number returned by uname") return } minor, err = strconv.Atoi(string(v.Release[2])) if err != nil { err = errors.New("cannot parse minor version number returned by uname") return } return }