fix(quic): Make DNS-over-QUIC work again

Signed-off-by: Sam Therapy <sam@samtherapy.net>

pkg/query/query_test.go

@@ -96,7 +96,7 @@ func TestCreateQ(t *testing.T) {
 				QUIC:   true,
 
 				Request: util.Request{
-					Server:  "dns.froth.zone",
+					Server:  "zero.dns0.eu",
 					Port:    853,
 					Type:    dns.TypeA,
 					Name:    "example.com.",

pkg/resolvers/QUIC.go

@@ -5,6 +5,7 @@ package resolvers
 import (
 	"context"
 	"crypto/tls"
+	"encoding/binary"
 	"fmt"
 	"io"
 	"strings"
@@ -52,6 +53,7 @@ func (resolver *QUICResolver) LookUp(msg *dns.Msg) (resp util.Response, err erro
 
 	resolver.opts.Logger.Debug("quic: packing query")
 
+	msg.Id = 0
 	// Compress request to over-the-wire
 	buf, err := msg.Pack()
 	if err != nil {
@@ -69,7 +71,7 @@ func (resolver *QUICResolver) LookUp(msg *dns.Msg) (resp util.Response, err erro
 
 	resolver.opts.Logger.Debug("quic: writing to stream")
 
-	_, err = stream.Write(buf)
+	_, err = stream.Write(rfc9250prefix(buf))
 	if err != nil {
 		return resp, fmt.Errorf("doq: quic stream write: %w", err)
 	}
@@ -101,10 +103,19 @@ func (resolver *QUICResolver) LookUp(msg *dns.Msg) (resp util.Response, err erro
 
 	resolver.opts.Logger.Debug("quic: unpacking response")
 
-	err = resp.DNS.Unpack(fullRes)
+	// Unpack response and lop off the first two bytes (RFC 9250 moment)
+	err = resp.DNS.Unpack(fullRes[2:])
 	if err != nil {
 		return resp, fmt.Errorf("doq: unpack: %w", err)
 	}
 
 	return
 }
+
+// rfc9250prefix adds a two-byte prefix to the input data as per RFC 9250.
+func rfc9250prefix(in []byte) []byte {
+	out := make([]byte, 2+len(in))
+	binary.BigEndian.PutUint16(out, uint16(len(in)))
+	copy(out[2:], in)
+	return out
+}

pkg/resolvers/QUIC_test.go

@@ -35,21 +35,6 @@ func TestQuic(t *testing.T) {
 				},
 			},
 		},
-		{
-			"Valid, Froth",
-			&util.Options{
-				QUIC:   true,
-				Logger: util.InitLogger(0),
-				Request: util.Request{
-					Server:  "dns.froth.zone",
-					Type:    dns.TypeA,
-					Name:    "git.freecumextremist.com",
-					Port:    853,
-					Timeout: 750 * time.Millisecond,
-					Retries: 3,
-				},
-			},
-		},
 		{
 			"Bad domain",
 			&util.Options{
@@ -107,6 +92,7 @@ func TestQuic(t *testing.T) {
 				res util.Response
 				err error
 			)
+
 			for i := 0; i <= test.opts.Request.Retries; i++ {
 				res, err = query.CreateQuery(test.opts)
 				if err == nil {