1 // Copyright 2016 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.
15 // Pledge implements the pledge syscall.
17 // The pledge syscall does not accept execpromises on OpenBSD releases
20 // execpromises must be empty when Pledge is called on OpenBSD
21 // releases predating 6.3, otherwise an error will be returned.
23 // For more information see pledge(2).
24 func Pledge(promises, execpromises string) error {
25 maj, min, err := majmin()
30 err = pledgeAvailable(maj, min, execpromises)
35 pptr, err := syscall.BytePtrFromString(promises)
40 // This variable will hold either a nil unsafe.Pointer or
41 // an unsafe.Pointer to a string (execpromises).
42 var expr unsafe.Pointer
44 // If we're running on OpenBSD > 6.2, pass execpromises to the syscall.
45 if maj > 6 || (maj == 6 && min > 2) {
46 exptr, err := syscall.BytePtrFromString(execpromises)
50 expr = unsafe.Pointer(exptr)
53 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
61 // PledgePromises implements the pledge syscall.
63 // This changes the promises and leaves the execpromises untouched.
65 // For more information see pledge(2).
66 func PledgePromises(promises string) error {
67 maj, min, err := majmin()
72 err = pledgeAvailable(maj, min, "")
77 // This variable holds the execpromises and is always nil.
78 var expr unsafe.Pointer
80 pptr, err := syscall.BytePtrFromString(promises)
85 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
93 // PledgeExecpromises implements the pledge syscall.
95 // This changes the execpromises and leaves the promises untouched.
97 // For more information see pledge(2).
98 func PledgeExecpromises(execpromises string) error {
99 maj, min, err := majmin()
104 err = pledgeAvailable(maj, min, execpromises)
109 // This variable holds the promises and is always nil.
110 var pptr unsafe.Pointer
112 exptr, err := syscall.BytePtrFromString(execpromises)
117 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(pptr), uintptr(unsafe.Pointer(exptr)), 0)
125 // majmin returns major and minor version number for an OpenBSD system.
126 func majmin() (major int, minor int, err error) {
133 major, err = strconv.Atoi(string(v.Release[0]))
135 err = errors.New("cannot parse major version number returned by uname")
139 minor, err = strconv.Atoi(string(v.Release[2]))
141 err = errors.New("cannot parse minor version number returned by uname")
148 // pledgeAvailable checks for availability of the pledge(2) syscall
149 // based on the running OpenBSD version.
150 func pledgeAvailable(maj, min int, execpromises string) error {
151 // If OpenBSD <= 5.9, pledge is not available.
152 if (maj == 5 && min != 9) || maj < 5 {
153 return fmt.Errorf("pledge syscall is not available on OpenBSD %d.%d", maj, min)
156 // If OpenBSD <= 6.2 and execpromises is not empty,
157 // return an error - execpromises is not available before 6.3
158 if (maj < 6 || (maj == 6 && min <= 2)) && execpromises != "" {
159 return fmt.Errorf("cannot use execpromises on OpenBSD %d.%d", maj, min)