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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
package main
import (
"errors"
"fmt"
"net"
"os"
"os/signal"
"github.com/urfave/cli"
"golang.org/x/sys/unix"
"github.com/opencontainers/runc/libcontainer/utils"
)
const (
usage = `Open Container Initiative tests/cmd/pidfd-kill
pidfd-kill is an implementation of a consumer of runC's --pidfd-socket API.
After received SIGTERM, pidfd-kill sends the given signal to init process by
pidfd received from --pidfd-socket.
To use pidfd-kill, just specify a socket path at which you want to receive
pidfd:
$ pidfd-kill [--signal KILL] socket.sock
`
)
func main() {
app := cli.NewApp()
app.Name = "pidfd-kill"
app.Usage = usage
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "signal",
Value: "SIGKILL",
Usage: "Signal to send to the init process",
},
cli.StringFlag{
Name: "pid-file",
Value: "",
Usage: "Path to write the pidfd-kill process ID to",
},
}
app.Action = func(ctx *cli.Context) error {
args := ctx.Args()
if len(args) != 1 {
return errors.New("required a single socket path")
}
socketFile := ctx.Args()[0]
pidFile := ctx.String("pid-file")
if pidFile != "" {
pid := fmt.Sprintf("%d\n", os.Getpid())
if err := os.WriteFile(pidFile, []byte(pid), 0o644); err != nil {
return err
}
defer os.Remove(pidFile)
}
sigStr := ctx.String("signal")
if sigStr == "" {
sigStr = "SIGKILL"
}
sig := unix.SignalNum(sigStr)
pidfdFile, err := recvPidfd(socketFile)
if err != nil {
return err
}
defer pidfdFile.Close()
signalCh := make(chan os.Signal, 16)
signal.Notify(signalCh, unix.SIGTERM)
<-signalCh
return unix.PidfdSendSignal(int(pidfdFile.Fd()), sig, nil, 0)
}
if err := app.Run(os.Args); err != nil {
fmt.Fprintln(os.Stderr, "fatal error:", err)
os.Exit(1)
}
}
func recvPidfd(socketFile string) (*os.File, error) {
ln, err := net.Listen("unix", socketFile)
if err != nil {
return nil, err
}
defer ln.Close()
conn, err := ln.Accept()
if err != nil {
return nil, err
}
defer conn.Close()
unixconn, ok := conn.(*net.UnixConn)
if !ok {
return nil, errors.New("failed to cast to unixconn")
}
socket, err := unixconn.File()
if err != nil {
return nil, err
}
defer socket.Close()
return utils.RecvFile(socket)
}
|
