Fix norduser pid detection

norduser/service/fork.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os/exec"
+	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -71,15 +72,18 @@ func getRunningNorduserPIDs() ([]int, error) {
 }
 
 func findPIDOfUID(uids string, desiredUID uint32) int {
-	for _, pidUid := range strings.Split(uids, "\n") {
-		var pid, uid int
-		_, err := fmt.Sscanf(pidUid, " %d %d", &uid, &pid)
-		if err != nil {
-			log.Println("error when scanning ps output line: ", err)
+	re := regexp.MustCompile(`\s*(\d+)\s+(\d+)\s*`)
+
+	for _, uidPid := range strings.Split(uids, "\n") {
+		match := re.FindStringSubmatch(uidPid)
+		if len(match) != 3 {
+			log.Println(internal.ErrorPrefix+" invalid input line: ", uidPid)
 			continue
 		}
 
+		uid, _ := strconv.Atoi(match[1])
 		if uid == int(desiredUID) {
+			pid, _ := strconv.Atoi(match[2])
 			return pid
 		}
 	}

norduser/service/fork_test.go

@@ -48,34 +48,45 @@ func Test_findPIDOfUID(t *testing.T) {
 	tests := []struct {
 		name        string
 		uidToPID    []string
+		uid         int
 		expectedPID int
 	}{
 		{
 			name:        "empty list",
 			uidToPID:    []string{},
+			uid:         1001,
 			expectedPID: -1,
 		},
 		{
 			name:        "uid not present",
 			uidToPID:    []string{" 1004 35139", " 1003 35153", " 1002 35144"},
+			uid:         1001,
 			expectedPID: -1,
 		},
 		{
 			name:        "invalid pid",
 			uidToPID:    []string{" 1001 aaaa", " 1003 35153", " 1002 35144"},
+			uid:         1001,
 			expectedPID: -1,
 		},
 		{
 			name:        "pid found",
 			uidToPID:    []string{" 1001 35255", " 1003 35153", " 1002 35144"},
+			uid:         1001,
 			expectedPID: 35255,
 		},
+		{
+			name:        "different format",
+			uidToPID:    []string{" 1001 35255", "10003 35153", "1002 35144"},
+			uid:         10003,
+			expectedPID: 35153,
+		},
 	}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			pids := strings.Join(test.uidToPID, "\n")
-			result := findPIDOfUID(pids, 1001)
+			result := findPIDOfUID(pids, uint32(test.uid))
 			assert.Equal(t, test.expectedPID, result)
 		})
 	}