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.
6 // +build 386 amd64 arm
18 // Pledge implements the pledge syscall.
20 // The pledge syscall does not accept execpromises on OpenBSD releases
23 // execpromises must be empty when Pledge is called on OpenBSD
24 // releases predating 6.3, otherwise an error will be returned.
26 // For more information see pledge(2).
27 func Pledge(promises, execpromises string) error {
28 maj, min, err := majmin()
33 err = pledgeAvailable(maj, min, execpromises)
38 pptr, err := syscall.BytePtrFromString(promises)
43 // This variable will hold either a nil unsafe.Pointer or
44 // an unsafe.Pointer to a string (execpromises).
45 var expr unsafe.Pointer
47 // If we're running on OpenBSD > 6.2, pass execpromises to the syscall.
48 if maj > 6 || (maj == 6 && min > 2) {
49 exptr, err := syscall.BytePtrFromString(execpromises)
53 expr = unsafe.Pointer(exptr)
56 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
64 // PledgePromises implements the pledge syscall.
66 // This changes the promises and leaves the execpromises untouched.
68 // For more information see pledge(2).
69 func PledgePromises(promises string) error {
70 maj, min, err := majmin()
75 err = pledgeAvailable(maj, min, "")
80 // This variable holds the execpromises and is always nil.
81 var expr unsafe.Pointer
83 pptr, err := syscall.BytePtrFromString(promises)
88 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
96 // PledgeExecpromises implements the pledge syscall.
98 // This changes the execpromises and leaves the promises untouched.
100 // For more information see pledge(2).
101 func PledgeExecpromises(execpromises string) error {
102 maj, min, err := majmin()
107 err = pledgeAvailable(maj, min, execpromises)
112 // This variable holds the promises and is always nil.
113 var pptr unsafe.Pointer
115 exptr, err := syscall.BytePtrFromString(execpromises)
120 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(pptr), uintptr(unsafe.Pointer(exptr)), 0)
128 // majmin returns major and minor version number for an OpenBSD system.
129 func majmin() (major int, minor int, err error) {
136 major, err = strconv.Atoi(string(v.Release[0]))
138 err = errors.New("cannot parse major version number returned by uname")
142 minor, err = strconv.Atoi(string(v.Release[2]))
144 err = errors.New("cannot parse minor version number returned by uname")
151 // pledgeAvailable checks for availability of the pledge(2) syscall
152 // based on the running OpenBSD version.
153 func pledgeAvailable(maj, min int, execpromises string) error {
154 // If OpenBSD <= 5.9, pledge is not available.
155 if (maj == 5 && min != 9) || maj < 5 {
156 return fmt.Errorf("pledge syscall is not available on OpenBSD %d.%d", maj, min)
159 // If OpenBSD <= 6.2 and execpromises is not empty,
160 // return an error - execpromises is not available before 6.3
161 if (maj < 6 || (maj == 6 && min <= 2)) && execpromises != "" {
162 return fmt.Errorf("cannot use execpromises on OpenBSD %d.%d", maj, min)