summaryrefslogtreecommitdiff
path: root/pkg/systray/pid.go
blob: b898d4e40a896938d9752ee48d441f64eba886bb (plain)
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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
package systray

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"syscall"

	"0xacab.org/leap/bitmask-vpn/pkg/config"
	"github.com/keybase/go-ps"
)

var pidFile = filepath.Join(config.Path, "systray.pid")

func acquirePID() error {
	pid := syscall.Getpid()
	current, err := getPID()
	if err != nil {
		return err
	}

	if current != pid && pidRunning(current) {
		return fmt.Errorf("Another systray is running with pid: %d", current)
	}

	return setPID(pid)
}

func releasePID() error {
	pid := syscall.Getpid()
	current, err := getPID()
	if err != nil {
		return err
	}
	if current != 0 && current != pid {
		return fmt.Errorf("Can't release pid file, is not own by this process")
	}

	if current == pid {
		return os.Remove(pidFile)
	}
	return nil
}

func getPID() (int, error) {
	_, err := os.Stat(pidFile)
	if os.IsNotExist(err) {
		return 0, nil
	}
	if err != nil {
		return 0, err
	}

	file, err := os.Open(pidFile)
	if err != nil {
		return 0, err
	}
	defer file.Close()

	b, err := ioutil.ReadAll(file)
	if err != nil {
		return 0, err
	}
	if len(b) == 0 {
		return 0, nil
	}
	return strconv.Atoi(string(b))
}

func setPID(pid int) error {
	file, err := os.Create(pidFile)
	if err != nil {
		return err
	}
	defer file.Close()

	_, err = file.WriteString(fmt.Sprintf("%d", pid))
	return err
}

func pidRunning(pid int) bool {
	if pid == 0 {
		return false
	}
	proc, err := ps.FindProcess(pid)
	if err != nil {
		log.Printf("An error ocurred finding process: %v", err)
		return false
	}
	if proc == nil {
		return false
	}
	log.Printf("There is a running process with the pid %d and executable: %s", pid, proc.Executable())
	return strings.Contains(os.Args[0], proc.Executable())
}