chore: wireguard dns can work with domain-based server

dns/resolver.go

@@ -412,8 +412,11 @@ func (r *Resolver) asyncExchange(ctx context.Context, client []dnsClient, msg *D
 	return ch
 }
 
-// HasProxyServer has proxy server dns client
-func (r *Resolver) HasProxyServer() bool {
+// Invalid return this resolver can or can't be used
+func (r *Resolver) Invalid() bool {
+	if r == nil {
+		return false
+	}
 	return len(r.main) > 0
 }
 

dns/util.go

@@ -170,6 +170,14 @@ func getDialHandler(r *Resolver, proxyAdapter C.ProxyAdapter, proxyName string,
 					Host:    host,
 					DstPort: port,
 				}
+				if proxyAdapter.IsL3Protocol(metadata) {
+					dstIP, err := resolver.ResolveIPWithResolver(ctx, host, r)
+					if err != nil {
+						return nil, err
+					}
+					metadata.Host = ""
+					metadata.DstIP = dstIP
+				}
 				if proxyAdapter != nil {
 					return proxyAdapter.DialContext(ctx, metadata, opts...)
 				}