platform: Add service error wrapper for macOS system extension

experimental/libbox/service_error.go

@@ -0,0 +1,32 @@
+package libbox
+
+import (
+	"os"
+	"path/filepath"
+)
+
+func serviceErrorPath() string {
+	return filepath.Join(sWorkingPath, "network_extension_error")
+}
+
+func ClearServiceError() {
+	os.Remove(serviceErrorPath())
+}
+
+func ReadServiceError() (string, error) {
+	data, err := os.ReadFile(serviceErrorPath())
+	if err == nil {
+		os.Remove(serviceErrorPath())
+	}
+	return string(data), err
+}
+
+func WriteServiceError(message string) error {
+	errorFile, err := os.Create(serviceErrorPath())
+	if err != nil {
+		return err
+	}
+	errorFile.WriteString(message)
+	errorFile.Chown(sUserID, sGroupID)
+	return errorFile.Close()
+}