conf: support disable expired cache on specific domain.

package/luci-compat/files/luci/i18n/smartdns.zh-cn.po

@@ -2,6 +2,12 @@
 msgid "Additional Args for upstream dns servers"
 msgstr "额外的上游 DNS 服务器参数"
 
+msgid "Additional Rule Flag"
+msgstr "额外规则标识"
+
+msgid "Additional Flags for rules, read help on domain-rule for more information."
+msgstr "额外的规则标识，具体参考domain-rule的帮助说明。"
+
 msgid "Additional Server Args"
 msgstr "额外的服务器参数"
 

package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua

@@ -448,6 +448,12 @@ function o.validate(self, value)
     return nil, translate("NFTset name format error, format: [#[4|6]:[family#table#set]]")
 end
 
+---- other args
+o = s:taboption("forwarding", Value, "addition_flag", translate("Additional Rule Flag"), translate("Additional Flags for rules, read help on domain-rule for more information."))
+o.default = ""
+o.rempty = true
+o.modalonly = true;
+
 o = s:taboption("forwarding", FileUpload, "forwarding_domain_set_file", translate("Domain List File"),
     translate("Upload domain list file, or configure auto download from Download File Setting page."))
 o.rmempty = true