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comparison vendor/golang.org/x/sys/unix/pledge_openbsd.go @ 66:787b5ee0289d draft

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Use vendored modules Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
author yakumo.izuru
date Sun, 23 Jul 2023 13:18:53 +0000
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65:6d985efa0f7a 66:787b5ee0289d
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.
4
5 package unix
6
7 import (
8 "errors"
9 "fmt"
10 "strconv"
11 "syscall"
12 "unsafe"
13 )
14
15 // Pledge implements the pledge syscall.
16 //
17 // The pledge syscall does not accept execpromises on OpenBSD releases
18 // before 6.3.
19 //
20 // execpromises must be empty when Pledge is called on OpenBSD
21 // releases predating 6.3, otherwise an error will be returned.
22 //
23 // For more information see pledge(2).
24 func Pledge(promises, execpromises string) error {
25 maj, min, err := majmin()
26 if err != nil {
27 return err
28 }
29
30 err = pledgeAvailable(maj, min, execpromises)
31 if err != nil {
32 return err
33 }
34
35 pptr, err := syscall.BytePtrFromString(promises)
36 if err != nil {
37 return err
38 }
39
40 // This variable will hold either a nil unsafe.Pointer or
41 // an unsafe.Pointer to a string (execpromises).
42 var expr unsafe.Pointer
43
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)
47 if err != nil {
48 return err
49 }
50 expr = unsafe.Pointer(exptr)
51 }
52
53 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
54 if e != 0 {
55 return e
56 }
57
58 return nil
59 }
60
61 // PledgePromises implements the pledge syscall.
62 //
63 // This changes the promises and leaves the execpromises untouched.
64 //
65 // For more information see pledge(2).
66 func PledgePromises(promises string) error {
67 maj, min, err := majmin()
68 if err != nil {
69 return err
70 }
71
72 err = pledgeAvailable(maj, min, "")
73 if err != nil {
74 return err
75 }
76
77 // This variable holds the execpromises and is always nil.
78 var expr unsafe.Pointer
79
80 pptr, err := syscall.BytePtrFromString(promises)
81 if err != nil {
82 return err
83 }
84
85 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0)
86 if e != 0 {
87 return e
88 }
89
90 return nil
91 }
92
93 // PledgeExecpromises implements the pledge syscall.
94 //
95 // This changes the execpromises and leaves the promises untouched.
96 //
97 // For more information see pledge(2).
98 func PledgeExecpromises(execpromises string) error {
99 maj, min, err := majmin()
100 if err != nil {
101 return err
102 }
103
104 err = pledgeAvailable(maj, min, execpromises)
105 if err != nil {
106 return err
107 }
108
109 // This variable holds the promises and is always nil.
110 var pptr unsafe.Pointer
111
112 exptr, err := syscall.BytePtrFromString(execpromises)
113 if err != nil {
114 return err
115 }
116
117 _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(pptr), uintptr(unsafe.Pointer(exptr)), 0)
118 if e != 0 {
119 return e
120 }
121
122 return nil
123 }
124
125 // majmin returns major and minor version number for an OpenBSD system.
126 func majmin() (major int, minor int, err error) {
127 var v Utsname
128 err = Uname(&v)
129 if err != nil {
130 return
131 }
132
133 major, err = strconv.Atoi(string(v.Release[0]))
134 if err != nil {
135 err = errors.New("cannot parse major version number returned by uname")
136 return
137 }
138
139 minor, err = strconv.Atoi(string(v.Release[2]))
140 if err != nil {
141 err = errors.New("cannot parse minor version number returned by uname")
142 return
143 }
144
145 return
146 }
147
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)
154 }
155
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)
160 }
161
162 return nil
163 }