From 889ee022e7d21c9182fcc56194265bcc2f182e08 Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sat, 8 May 2021 16:15:19 +0530
Subject: [PATCH] ResolverDnsCache: updated Query() method with correct check
 conditions for auth and cache response.

---
 DnsServerCore/Dns/ResolverDnsCache.cs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/DnsServerCore/Dns/ResolverDnsCache.cs b/DnsServerCore/Dns/ResolverDnsCache.cs
index 82f5ddf1..36d60a08 100644
--- a/DnsServerCore/Dns/ResolverDnsCache.cs
+++ b/DnsServerCore/Dns/ResolverDnsCache.cs
@@ -43,25 +43,25 @@ namespace DnsServerCore.Dns
 
         #region public
 
-        public virtual DnsDatagram Query(DnsDatagram request, bool serveStale = false)
+        public virtual DnsDatagram Query(DnsDatagram request, bool serveStaleAndResetExpiry = false)
         {
             DnsDatagram authResponse = _authZoneManager.Query(request, true);
-            if ((authResponse != null))
+            if (authResponse is not null)
             {
-                if ((authResponse.Answer.Count > 0) || ((authResponse.Authority.Count > 0) && (authResponse.Authority[0].Type == DnsResourceRecordType.SOA)))
+                if ((authResponse.RCODE != DnsResponseCode.NoError) || (authResponse.Answer.Count > 0) || (authResponse.Authority.Count == 0) || (authResponse.Authority[0].Type == DnsResourceRecordType.SOA))
                     return authResponse;
             }
 
-            DnsDatagram cacheResponse = _cacheZoneManager.Query(request, serveStale);
-            if (cacheResponse != null)
+            DnsDatagram cacheResponse = _cacheZoneManager.Query(request, serveStaleAndResetExpiry);
+            if (cacheResponse is not null)
             {
-                if ((cacheResponse.Answer.Count > 0) || ((cacheResponse.Authority.Count > 0) && (cacheResponse.Authority[0].Type == DnsResourceRecordType.SOA)))
+                if ((cacheResponse.RCODE != DnsResponseCode.NoError) || (cacheResponse.Answer.Count > 0) || (cacheResponse.Authority.Count == 0) || (cacheResponse.Authority[0].Type == DnsResourceRecordType.SOA))
                     return cacheResponse;
             }
 
-            if ((authResponse != null) && (authResponse.Authority.Count > 0))
+            if ((authResponse is not null) && (authResponse.Authority.Count > 0))
             {
-                if ((cacheResponse != null) && (cacheResponse.Authority.Count > 0))
+                if ((cacheResponse is not null) && (cacheResponse.Authority.Count > 0))
                 {
                     if (cacheResponse.Authority[0].Name.Length > authResponse.Authority[0].Name.Length)
                         return cacheResponse;