From 6d959115584f4861ef9c1287f21510d9e41b0c4f Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Wed, 11 Jan 2012 16:16:09 +0100
Subject: [PATCH] Dont allow the question section to be compressed

---
 dnssec.go     | 2 +-
 msg.go        | 9 +++++----
 nsec3.go      | 2 +-
 parse_test.go | 4 ++--
 types.go      | 2 +-
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/dnssec.go b/dnssec.go
index 413b7e84..1afd0bbc 100644
--- a/dnssec.go
+++ b/dnssec.go
@@ -133,7 +133,7 @@ func (k *RR_DNSKEY) ToDS(h int) *RR_DS {
 	wire = wire[:n]
 
 	owner := make([]byte, 255)
-	off, ok1 := PackDomainName(k.Hdr.Name, owner, 0, nil)
+	off, ok1 := PackDomainName(k.Hdr.Name, owner, 0, nil, false)
 	if !ok1 {
 		return nil
 	}
diff --git a/msg.go b/msg.go
index 39683cb6..3ec5640b 100644
--- a/msg.go
+++ b/msg.go
@@ -176,7 +176,7 @@ var Rcode_str = map[int]string{
 // PackDomainName packs a domain name s into msg[off:].
 // Domain names are a sequence of counted strings
 // split at the dots. They end with a zero-length string.
-func PackDomainName(s string, msg []byte, off int, compression map[string]int) (off1 int, ok bool) {
+func PackDomainName(s string, msg []byte, off int, compression map[string]int, compress bool) (off1 int, ok bool) {
 	// Add trailing dot to canonicalize name.
 	lenmsg := len(msg)
 	if n := len(s); n == 0 || s[n-1] != '.' {
@@ -234,7 +234,8 @@ func PackDomainName(s string, msg []byte, off int, compression map[string]int) (
 					// keep the pointer offset we get back and store
 					// the offset of the current name, because that's
 					// where we need to insert the pointer later
-					if pointer == -1 {
+                                        // If compress is true, we allowed to compress this dname
+					if pointer == -1 && compress {
 						pointer = p         // Where to point to
 						nameoffset = offset // Where to point from
 					}
@@ -484,9 +485,9 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 				fallthrough // No compression
 			case "cdomain-name":
 				if val.Type().Field(i).Tag == "cdomain-name" {
-					off, ok = PackDomainName(s, msg, off, compression)
+					off, ok = PackDomainName(s, msg, off, compression, true)
 				} else {
-					off, ok = PackDomainName(s, msg, off, nil)
+					off, ok = PackDomainName(s, msg, off, compression, false)
 				}
 				if !ok {
 					//fmt.Fprintf(os.Stderr, "dns: overflow packing domain-name")
diff --git a/nsec3.go b/nsec3.go
index 684ac337..2124f60b 100644
--- a/nsec3.go
+++ b/nsec3.go
@@ -23,7 +23,7 @@ func HashName(label string, ha, iter int, salt string) string {
 	}
 	wire = wire[:n]
 	name := make([]byte, 255)
-	off, ok1 := PackDomainName(strings.ToLower(label), name, 0, nil)
+	off, ok1 := PackDomainName(strings.ToLower(label), name, 0, nil, false)
 	if !ok1 {
 		return ""
 	}
diff --git a/parse_test.go b/parse_test.go
index 0a5c0615..976f4727 100644
--- a/parse_test.go
+++ b/parse_test.go
@@ -76,7 +76,7 @@ Activate: 20110302104537`
 
 func TestDotInName(t *testing.T) {
 	buf := make([]byte, 20)
-	PackDomainName("aa\\.bb.nl.", buf, 0, nil)
+	PackDomainName("aa\\.bb.nl.", buf, 0, nil, false)
 	// index 3 must be a real dot
 	if buf[3] != '.' {
 		t.Log("Dot should be a real dot")
@@ -136,7 +136,7 @@ func TestDomainName(t *testing.T) {
 
 
         for _, ts := range tests {
-                if _, ok := PackDomainName(ts, dbuff, 0, nil); !ok {
+                if _, ok := PackDomainName(ts, dbuff, 0, nil, false); !ok {
                         t.Log("Not a valid domain name")
                         t.Fail()
                         continue
diff --git a/types.go b/types.go
index 471e25b1..6c81de8d 100644
--- a/types.go
+++ b/types.go
@@ -129,7 +129,7 @@ const (
 
 // DNS queries.
 type Question struct {
-	Name   string "cdomain-name" // "cdomain-name" specifies encoding (and may be compressed)
+	Name   string "domain-name" // "cdomain-name" specifies encoding (and may be compressed)
 	Qtype  uint16
 	Qclass uint16
 }