From 7f40a046385bef3dcfab81bae937bfbeec9c741c Mon Sep 17 00:00:00 2001
From: Niklas <niklas@kapelle.org>
Date: Thu, 31 Dec 2020 14:11:07 +0100
Subject: [PATCH] only one question per query

---
 coolDns.go | 104 +++++++++++++++++++++++++++--------------------------
 1 file changed, 54 insertions(+), 50 deletions(-)

diff --git a/coolDns.go b/coolDns.go
index a9e47d8..970d8db 100644
--- a/coolDns.go
+++ b/coolDns.go
@@ -278,65 +278,69 @@ func handleRequest(w dns.ResponseWriter, r *dns.Msg, zone zoneView) {
 	m.SetReply(r)
 	m.Authoritative = true
 
-	// maybe only support one question per query like most servers do it ???
-	for _, q := range r.Question {
-		rrs := zone.rr[q.Qtype]
+	// Only support one question per query because all the other server also does that
+	if len(r.Question) != 1 {
+		rcodeRequest(w, r, dns.RcodeServerFailure)
+	}
 
-		// Handle ANY
-		if q.Qtype == dns.TypeANY {
-			for _, rrType := range anyRecordTypes {
-				m.Answer = append(m.Answer, zone.rr[rrType][q.Name]...)
-			}
-		} else {
-			// Handle any other type
-			m.Answer = append(m.Answer, rrs[q.Name]...)
+	q := r.Question[0]
 
-			// Check for wildcard
-			if len(m.Answer) == 0 {
-				parts := dns.SplitDomainName(q.Name)[1:]
-				searchDomain := "*." + dns.Fqdn(strings.Join(parts, "."))
-				foundDomain := rrs[searchDomain]
-				for _, rr := range foundDomain {
-					newRR := rr
-					newRR.Header().Name = q.Name
-					m.Answer = append(m.Answer, newRR)
-				}
+	rrs := zone.rr[q.Qtype]
+
+	// Handle ANY
+	if q.Qtype == dns.TypeANY {
+		for _, rrType := range anyRecordTypes {
+			m.Answer = append(m.Answer, zone.rr[rrType][q.Name]...)
+		}
+	} else {
+		// Handle any other type
+		m.Answer = append(m.Answer, rrs[q.Name]...)
+
+		// Check for wildcard
+		if len(m.Answer) == 0 {
+			parts := dns.SplitDomainName(q.Name)[1:]
+			searchDomain := "*." + dns.Fqdn(strings.Join(parts, "."))
+			foundDomain := rrs[searchDomain]
+			for _, rr := range foundDomain {
+				newRR := rr
+				newRR.Header().Name = q.Name
+				m.Answer = append(m.Answer, newRR)
 			}
 		}
+	}
 
-		// Handle extras
-		switch q.Qtype {
-		// Dont handle extra stuff when answering ANY request
-		// case dns.TypeANY:
-		// 	fallthrough
-		case dns.TypeMX:
-			// Resolve MX domains
-			for _, mxRR := range m.Answer {
-				if t, ok := mxRR.(*dns.MX); ok {
-					m.Extra = append(m.Extra, zone.rr[dns.TypeA][t.Mx]...)
-					m.Extra = append(m.Extra, zone.rr[dns.TypeAAAA][t.Mx]...)
-				}
+	// Handle extras
+	switch q.Qtype {
+	// Dont handle extra stuff when answering ANY request
+	// case dns.TypeANY:
+	// 	fallthrough
+	case dns.TypeMX:
+		// Resolve MX domains
+		for _, mxRR := range m.Answer {
+			if t, ok := mxRR.(*dns.MX); ok {
+				m.Extra = append(m.Extra, zone.rr[dns.TypeA][t.Mx]...)
+				m.Extra = append(m.Extra, zone.rr[dns.TypeAAAA][t.Mx]...)
 			}
-		case dns.TypeA, dns.TypeAAAA:
-			if len(m.Answer) == 0 {
-				// no A or AAAA found. Look for CNAME
-				m.Answer = append(m.Answer, zone.rr[dns.TypeCNAME][q.Name]...)
-				if len(m.Answer) != 0 {
-					// Resolve CNAME
-					for _, nameRR := range m.Answer {
-						if t, ok := nameRR.(*dns.CNAME); ok {
-							m.Answer = append(m.Answer, zone.rr[q.Qtype][t.Target]...)
-						}
+		}
+	case dns.TypeA, dns.TypeAAAA:
+		if len(m.Answer) == 0 {
+			// no A or AAAA found. Look for CNAME
+			m.Answer = append(m.Answer, zone.rr[dns.TypeCNAME][q.Name]...)
+			if len(m.Answer) != 0 {
+				// Resolve CNAME
+				for _, nameRR := range m.Answer {
+					if t, ok := nameRR.(*dns.CNAME); ok {
+						m.Answer = append(m.Answer, zone.rr[q.Qtype][t.Target]...)
 					}
 				}
 			}
-		case dns.TypeNS:
-			// Resove NS records
-			for _, nsRR := range m.Answer {
-				if t, ok := nsRR.(*dns.NS); ok {
-					m.Extra = append(m.Extra, zone.rr[dns.TypeA][t.Ns]...)
-					m.Extra = append(m.Extra, zone.rr[dns.TypeAAAA][t.Ns]...)
-				}
+		}
+	case dns.TypeNS:
+		// Resove NS records
+		for _, nsRR := range m.Answer {
+			if t, ok := nsRR.(*dns.NS); ok {
+				m.Extra = append(m.Extra, zone.rr[dns.TypeA][t.Ns]...)
+				m.Extra = append(m.Extra, zone.rr[dns.TypeAAAA][t.Ns]...)
 			}
 		}
 	}