set subprocess group ID for common.External

main/commands/service.go

@@ -97,9 +97,7 @@ func startService() error {
 			return err
 		}
 	}
-	if err := service.SetUidGid("0", common.CoreGid); err != nil {
-		return err
-	}
+	service.SetUidGid("0", common.CoreGid)
 	ignoreSignals()
 	service.Start()
 	if service.Err() != nil {

main/commands/update.go

@@ -50,7 +50,7 @@ func (this *UpdateCommand) Execute(args []string) error {
 	log.HandleDebug("CurrentGid: " + strconv.Itoa(os.Getgid()))
 	if *builds.BypassSelf && strconv.Itoa(os.Getgid()) != common.CoreGid {
 		self := common.NewExternal(0, os.Stdout, os.Stderr, os.Args[0], os.Args[1:]...)
-		_ = self.SetUidGid("0", common.CoreGid)
+		self.SetUidGid("0", common.CoreGid)
 		log.HandleDebug("will exec update command in new xrayhelper process, waiting")
 		self.Run()
 		var exitError *exec.ExitError

main/common/external.go

@@ -6,12 +6,14 @@ import (
 	"errors"
 	"io"
 	"os/exec"
+	"strconv"
+	"syscall"
 	"time"
 )
 
 type External interface {
 	Err() error
-	SetUidGid(uid string, gid string) error
+	SetUidGid(uid string, gid string)
 	AppendEnv(env string)
 	Run()
 	Start()
@@ -44,9 +46,18 @@ func NewExternal(timeout time.Duration, out io.Writer, err io.Writer, name strin
 		ex.cmd.Stdout = out
 		ex.cmd.Stderr = err
 	}
+	ex.cmd.SysProcAttr = &syscall.SysProcAttr{}
+	ex.cmd.SysProcAttr.Setpgid = true
 	return &ex
 }
 
+// SetUidGid implement in linux
+func (this *external) SetUidGid(uid string, gid string) {
+	uidInt, _ := strconv.Atoi(uid)
+	gidInt, _ := strconv.Atoi(gid)
+	this.cmd.SysProcAttr.Credential = &syscall.Credential{Uid: uint32(uidInt), Gid: uint32(gidInt)}
+}
+
 // AppendEnv add env variable, eg: JAVA_HOME=/usr/local/java/
 func (this *external) AppendEnv(env string) {
 	this.cmd.Env = append(this.cmd.Env, env)