1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
package sys
import (
"errors"
"fmt"
"os"
"os/exec"
"strconv"
"sync"
"hakurei.app/container"
"hakurei.app/hst"
"hakurei.app/internal"
)
// Hsu caches responses from cmd/hsu.
type Hsu struct {
uidOnce sync.Once
uidCopy map[int]struct {
uid int
err error
}
uidMu sync.RWMutex
}
var ErrHsuAccess = errors.New("current user is not in the hsurc file")
func (h *Hsu) Uid(identity int) (int, error) {
h.uidOnce.Do(func() {
h.uidCopy = make(map[int]struct {
uid int
err error
})
})
{
h.uidMu.RLock()
u, ok := h.uidCopy[identity]
h.uidMu.RUnlock()
if ok {
return u.uid, u.err
}
}
h.uidMu.Lock()
defer h.uidMu.Unlock()
u := struct {
uid int
err error
}{}
defer func() { h.uidCopy[identity] = u }()
u.uid = -1
hsuPath := internal.MustHsuPath()
cmd := exec.Command(hsuPath)
cmd.Path = hsuPath
cmd.Stderr = os.Stderr // pass through fatal messages
cmd.Env = []string{"HAKUREI_APP_ID=" + strconv.Itoa(identity)}
cmd.Dir = container.FHSRoot
var (
p []byte
exitError *exec.ExitError
)
const step = "obtain uid from hsu"
if p, u.err = cmd.Output(); u.err == nil {
u.uid, u.err = strconv.Atoi(string(p))
if u.err != nil {
u.err = &hst.AppError{Step: step, Err: u.err, Msg: "invalid uid string from hsu"}
}
} else if errors.As(u.err, &exitError) && exitError != nil && exitError.ExitCode() == 1 {
// hsu prints an error message in this case
u.err = &hst.AppError{Step: step, Err: ErrHsuAccess}
} else if os.IsNotExist(u.err) {
u.err = &hst.AppError{Step: step, Err: os.ErrNotExist,
Msg: fmt.Sprintf("the setuid helper is missing: %s", hsuPath)}
}
return u.uid, u.err
}
|
