Fix ipv6 dns entries

pkg/networkservice/connectioncontext/dnscontext/vl3dns/server.go

@@ -31,10 +31,10 @@ import (
 	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsconfig"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils"
+	dnschain "github.com/networkservicemesh/sdk/pkg/tools/dnsutils/chain"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/dnsconfigs"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/fanout"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/memory"
-	dnsnext "github.com/networkservicemesh/sdk/pkg/tools/dnsutils/next"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/noloop"
 	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/norecursion"
 	"github.com/networkservicemesh/sdk/pkg/tools/ippool"
@@ -70,7 +70,7 @@ func NewServer(chanCtx context.Context, getDNSServerIP func() net.IP, opts ...Op
 	}
 
 	if result.dnsServer == nil {
-		result.dnsServer = dnsnext.NewDNSHandler(
+		result.dnsServer = dnschain.NewDNSHandler(
 			dnsconfigs.NewDNSHandler(result.dnsConfigs),
 			noloop.NewDNSHandler(),
 			norecursion.NewDNSHandler(),

pkg/tools/dnsutils/memory/handler.go

@@ -62,7 +62,9 @@ func (f *memoryHandler) ServeDNS(ctx context.Context, rw dns.ResponseWriter, msg
 	if !ok {
 		next.Handler(ctx).ServeDNS(ctx, rwWrapper, msg)
 		if !rwWrapper.passed {
-			dns.HandleFailed(rw, msg)
+			// Send NXDomain because we didn't find anything
+			m := new(dns.Msg)
+			_ = rw.WriteMsg(m.SetRcode(msg, dns.RcodeNameError))
 		}
 		return
 	}
@@ -81,7 +83,9 @@ func (f *memoryHandler) ServeDNS(ctx context.Context, rw dns.ResponseWriter, msg
 	if len(resp.Answer) == 0 {
 		next.Handler(ctx).ServeDNS(ctx, rwWrapper, msg)
 		if !rwWrapper.passed {
-			dns.HandleFailed(rw, msg)
+			// Send NXDomain because we didn't find anything
+			m := new(dns.Msg)
+			_ = rw.WriteMsg(m.SetRcode(msg, dns.RcodeNameError))
 		}
 		return
 	}
@@ -99,29 +103,29 @@ func NewDNSHandler(records *Map) dnsutils.Handler {
 	return &memoryHandler{records: records}
 }
 func a(domain string, ips []net.IP) []dns.RR {
-	answers := make([]dns.RR, len(ips))
-	for i, ip := range ips {
+	var answers []dns.RR
+	for _, ip := range ips {
 		if ip.To4() == nil {
 			continue
 		}
 		r := new(dns.A)
 		r.Hdr = dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: defaultTTL}
 		r.A = ip
-		answers[i] = r
+		answers = append(answers, r)
 	}
 	return answers
 }
 
 func aaaa(domain string, ips []net.IP) []dns.RR {
-	answers := make([]dns.RR, len(ips))
-	for i, ip := range ips {
-		if ip.To16() == nil {
+	var answers []dns.RR
+	for _, ip := range ips {
+		if ip.To4() != nil {
 			continue
 		}
 		r := new(dns.AAAA)
 		r.Hdr = dns.RR_Header{Name: domain, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: defaultTTL}
 		r.AAAA = ip
-		answers[i] = r
+		answers = append(answers, r)
 	}
 	return answers
 }

pkg/tools/dnsutils/memory/handler_test.go

@@ -0,0 +1,88 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package memory_test
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/miekg/dns"
+	"github.com/stretchr/testify/require"
+
+	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/memory"
+	"github.com/networkservicemesh/sdk/pkg/tools/dnsutils/next"
+)
+
+type responseWriter struct {
+	dns.ResponseWriter
+	Response *dns.Msg
+}
+
+func (r *responseWriter) WriteMsg(m *dns.Msg) error {
+	r.Response = m
+	return nil
+}
+
+func TestDomainSearches(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	// Store two entries for IPv4 and IPv6
+	records := new(memory.Map)
+	records.Store("example.com.", []net.IP{net.ParseIP("1.1.1.1")})
+	records.Store("example.net.", []net.IP{net.ParseIP("2001:db8::68")})
+
+	handler := next.NewDNSHandler(
+		memory.NewDNSHandler(records),
+	)
+	rw := &responseWriter{}
+	m := &dns.Msg{}
+
+	// Get example.com IPv4. Expect success
+	m.SetQuestion(dns.Fqdn("example.com"), dns.TypeA)
+	handler.ServeDNS(ctx, rw, m)
+
+	resp := rw.Response.Copy()
+	require.Equal(t, resp.MsgHdr.Rcode, dns.RcodeSuccess)
+	require.NotNil(t, resp.Answer)
+	require.Equal(t, resp.Answer[0].(*dns.A).A.String(), "1.1.1.1")
+
+	// Get example.com IPv6. Expect NXDomain
+	m.SetQuestion(dns.Fqdn("example.com"), dns.TypeAAAA)
+	handler.ServeDNS(ctx, rw, m)
+
+	resp = rw.Response.Copy()
+	require.Equal(t, resp.MsgHdr.Rcode, dns.RcodeNameError)
+
+	// Get example.net IPv4. Expect NXDomain
+	m.SetQuestion(dns.Fqdn("example.net"), dns.TypeA)
+	handler.ServeDNS(ctx, rw, m)
+
+	resp = rw.Response.Copy()
+	require.Equal(t, resp.MsgHdr.Rcode, dns.RcodeNameError)
+
+	// Get example.net IPv6. Expect success
+	m.SetQuestion(dns.Fqdn("example.net"), dns.TypeAAAA)
+	handler.ServeDNS(ctx, rw, m)
+
+	resp = rw.Response.Copy()
+	require.Equal(t, resp.MsgHdr.Rcode, dns.RcodeSuccess)
+	require.NotNil(t, resp.Answer)
+	require.Equal(t, resp.Answer[0].(*dns.AAAA).AAAA.String(), "2001:db8::68")
+}