From a7675988d876ad45656dcd95c2e824dcc4c2986a Mon Sep 17 00:00:00 2001
From: Ekko <beijiu572@gmail.com>
Date: Tue, 24 Sep 2024 22:06:37 +0800
Subject: [PATCH] fix: compatible issue when DNS msg not be compressed (#646)

Co-authored-by: mzz2017 <2017@duck.com>
---
 control/dns_control.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/control/dns_control.go b/control/dns_control.go
index 8b41c30..b6cbaee 100644
--- a/control/dns_control.go
+++ b/control/dns_control.go
@@ -166,6 +166,7 @@ func (c *DnsController) LookupDnsRespCache_(msg *dnsmessage.Msg, cacheKey string
 	cache := c.LookupDnsRespCache(cacheKey, ignoreFixedTtl)
 	if cache != nil {
 		cache.FillInto(msg)
+		msg.Compress = true
 		b, err := msg.Pack()
 		if err != nil {
 			c.log.Warnf("failed to pack: %v", err)
@@ -497,6 +498,7 @@ func (c *DnsController) sendReject_(dnsMessage *dnsmessage.Msg, req *udpRequest)
 	dnsMessage.Response = true
 	dnsMessage.RecursionAvailable = true
 	dnsMessage.Truncated = false
+	dnsMessage.Compress = true
 	if c.log.IsLevelEnabled(logrus.TraceLevel) {
 		c.log.WithFields(logrus.Fields{
 			"question": dnsMessage.Question,
@@ -756,6 +758,7 @@ func (c *DnsController) dialSend(invokingDepth int, req *udpRequest, data []byte
 	if needResp {
 		// Keep the id the same with request.
 		respMsg.Id = id
+		respMsg.Compress = true
 		data, err = respMsg.Pack()
 		if err != nil {
 			return err