Add more tests

_examples/reflect/reflect.go

@@ -69,7 +69,7 @@ func handleReflect(w dns.ResponseWriter, r *dns.Msg) {
 	m.Extra[0] = t
 	m.Answer[0] = rr
 	b, ok := m.Pack()
-	if !ok {
+        if !ok {
                 log.Print("Packing failed")
 		return
 	}

dns_test.go

@@ -1,6 +1,7 @@
 package dns
 
 import (
+	"net"
 	"testing"
 )
 
@@ -43,6 +44,29 @@ func TestPackUnpack(t *testing.T) {
 	}
 }
 
+func TestPackUnpack2(t *testing.T) {
+	m := new(Msg)
+	m.Extra = make([]RR, 1)
+	m.Answer = make([]RR, 1)
+        dom := "miek.nl."
+        rr := new(RR_A)
+	rr.Hdr = RR_Header{Name: dom, Rrtype: TypeA, Class: ClassINET, Ttl: 0}
+	rr.A = net.IPv4(127, 0, 0, 1)
+
+	x := new(RR_TXT)
+	x.Hdr = RR_Header{Name: dom, Rrtype: TypeTXT, Class: ClassINET, Ttl: 0}
+	x.Txt = "heelalaollo"
+
+	m.Extra[0] = x
+	m.Answer[0] = rr
+	_, ok := m.Pack()
+	if !ok {
+		t.Log("Packing failed")
+		t.Fail()
+		return
+	}
+}
+
 func TestEDNS_RR(t *testing.T) {
 	edns := new(RR_OPT)
 	edns.Hdr.Name = "." // must . be for edns

msg.go

@@ -375,7 +375,7 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 				switch fv.Len() {
 				case net.IPv6len:
 					if off+net.IPv4len > lenmsg {
-						println("dns: overflow packing A")
+						println("dns: overflow packing A", off, lenmsg)
 						return lenmsg, false
 					}
 					msg[off] = byte(fv.Index(12).Uint())
@@ -385,7 +385,7 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 					off += net.IPv4len
 				case net.IPv4len:
 					if off+net.IPv4len > lenmsg {
-						println("dns: overflow packing A")
+						println("dns: overflow packing A", off, lenmsg)
 						return lenmsg, false
 					}
 					msg[off] = byte(fv.Index(0).Uint())
@@ -1014,7 +1014,7 @@ func (dns *Msg) Pack() (msg []byte, ok bool) {
 	dh.Arcount = uint16(len(extra))
 
 	// TODO: still a little too much, but better than 64K...
-	msg = make([]byte, dns.Len()*2)
+	msg = make([]byte, dns.Len())
 
 	// Pack it in: header and then the pieces.
 	off := 0

types.go

@@ -494,7 +494,7 @@ func (rr *RR_A) String() string {
 }
 
 func (rr *RR_A) Len() int {
-	return rr.Hdr.Len() + 4 /// 4 bytes?
+	return rr.Hdr.Len() + net.IPv4len
 }
 
 type RR_AAAA struct {
@@ -511,7 +511,7 @@ func (rr *RR_AAAA) String() string {
 }
 
 func (rr *RR_AAAA) Len() int {
-	return rr.Hdr.Len() + 16
+	return rr.Hdr.Len() + net.IPv6len
 }
 
 type RR_LOC struct {