From 60f7a03e1b5e952f9d15f1a136bfabd24e80d9bd Mon Sep 17 00:00:00 2001
From: dop-bot <95738113+dop-bot@users.noreply.github.com>
Date: Tue, 2 Jan 2024 12:03:36 +0800
Subject: [PATCH] fix(dns): avoid early return when dns query refused (#2878)

* avoid early return when dns query refused

* address reviews
---
 app/dns/dns.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/dns/dns.go b/app/dns/dns.go
index 6efcb825..3b173677 100644
--- a/app/dns/dns.go
+++ b/app/dns/dns.go
@@ -215,7 +215,8 @@ func (s *DNS) LookupIP(domain string, option dns.IPOption) ([]net.IP, error) {
 			newError("failed to lookup ip for domain ", domain, " at server ", client.Name()).Base(err).WriteToLog()
 			errs = append(errs, err)
 		}
-		if err != context.Canceled && err != context.DeadlineExceeded && err != errExpectedIPNonMatch && err != dns.ErrEmptyResponse {
+		// 5 for RcodeRefused in miekg/dns, hardcode to reduce binary size
+		if err != context.Canceled && err != context.DeadlineExceeded && err != errExpectedIPNonMatch && err != dns.ErrEmptyResponse && dns.RCodeFromError(err) != 5 {
 			return nil, err
 		}
 	}