refine dns black list

src/main/scala/com/github/shadowsocks/utils/ConfigUtils.scala

@@ -161,6 +161,8 @@ object ConfigUtils {
       | reject = %s;
       | reject_policy = fail;
       | reject_recursively = on;
+      | exclude = %s;
+      | policy = included;
       | uptest = none;
       | preset = on;
       |}
@@ -173,6 +175,8 @@ object ConfigUtils {
       | reject = %s;
       | reject_policy = fail;
       | reject_recursively = on;
+      | exclude = %s;
+      | policy = included;
       | uptest = none;
       | preset = on;
       |}
@@ -218,6 +222,17 @@ object ConfigUtils {
     }
   }
 
+  def getBlackList(context: Context, app: ShadowsocksApplication): String = {
+    val default = context.getString(R.string.black_list)
+    try {
+      val container = app.containerHolder.getContainer
+      val update = container.getString("black_list")
+      if (update == null || update.isEmpty) default else update
+    } catch {
+      case ex: Exception => default
+    }
+  }
+
   def getPublicConfig(context: Context, container: Container, config: Config): Config = {
     val url = container.getString("proxy_url")
     val sig = Utils.getSignature(context)