luci-app-passwall: sync upstream

last commit: 031adb7a24

luci-app-passwall/luasrc/passwall/util_sing-box.lua

@@ -130,13 +130,10 @@ function gen_outbound(flag, node, tag, proxy_table)
 		if version_ge_1_12_0 then
 			--https://sing-box.sagernet.org/migration/#migrate-outbound-domain-strategy-option-to-domain-resolver
 			result.domain_strategy = nil
-			if node.domain_strategy then
-				local domain_resolver = {
-					server = "direct",
-					strategy = node.domain_strategy
-				}
-				result.domain_resolver = domain_resolver
-			end
+			result.domain_resolver = {
+				server = "direct",
+				strategy = (node.domain_strategy and node.domain_strategy ~="") and node.domain_strategy or nil
+			}
 		end
 
 		local tls = nil
@@ -1762,6 +1759,23 @@ function gen_config(var)
 				strategy = "prefer_ipv6"
 			}
 			direct_outbound.domain_resolver = domain_resolver
+			-- 当没有 direct dns 服务器时添加 local
+			if config.dns and config.dns.servers then
+				for _, server in ipairs(config.dns.servers) do
+					if server.tag == "direct" then
+						break
+					end
+				end
+			else
+				config.dns = {
+					servers = {
+						{
+							type = "local",
+							tag = "direct"
+						}
+					},
+				}
+			end
 		end
 		table.insert(outbounds,direct_outbound)