If we add a dot to a name, be sure to remove one from the length

client.go

@@ -237,12 +237,12 @@ func (c *Client) Exchange(m *Msg, a string) (r *Msg, err error) {
 	case "tcp":
 		in = make([]byte, MaxMsgSize)
 	case "udp":
-                size := UDPMsgSize
+		size := UDPMsgSize
-                for _, r := range m.Extra {
+		for _, r := range m.Extra {
-                        if r.Header().Rrtype == TypeOPT {
+			if r.Header().Rrtype == TypeOPT {
-                                size = int(r.(*RR_OPT).UDPSize())
+				size = int(r.(*RR_OPT).UDPSize())
-                        }
+			}
-                }
+		}
 		in = make([]byte, size)
 	}
 	if n, err = c.ExchangeBuffer(out, a, in); err != nil {

defaults.go

@@ -201,16 +201,20 @@ func (dns *Msg) IsEdns0() (ok bool) {
 // When false the returned labelcount and length is 0 and 0.
 func IsDomainName(s string) (uint8, uint8, bool) { // copied from net package.
 	// See RFC 1035, RFC 3696.
-        l := len(s)
+	l := len(s)
 	if l == 0 || l > 255 {
 		return 0, 0, false
 	}
-	// Simplify checking loop: make the name end in a dot
+	longer := 0
-        // Don't call Fqdn() to save another len(s)
+	// Simplify checking loop: make the name end in a dot.
-        if s[l-1] != '.' {
+	// Don't call Fqdn() to save another len(s).
-                s += "."
+	// Keep in mind that if we do this, we report a longer
-                l++
+	// length
-        }
+	if s[l-1] != '.' {
+		s += "."
+		l++
+		longer = 1
+	}
 	last := byte('.')
 	ok := false // ok once we've seen a letter
 	partlen := 0
@@ -219,7 +223,7 @@ func IsDomainName(s string) (uint8, uint8, bool) { // copied from net package.
 		c := s[i]
 		switch {
 		default:
-			return 0, uint8(l), false
+			return 0, uint8(l - longer), false
 		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || c == '_' || c == '*':
 			ok = true
 			partlen++
@@ -231,27 +235,27 @@ func IsDomainName(s string) (uint8, uint8, bool) { // copied from net package.
 		case c == '-':
 			// byte before dash cannot be dot
 			if last == '.' {
-				return 0, uint8(l), false
+				return 0, uint8(l - longer), false
 			}
 			partlen++
 		case c == '.':
 			// byte before dot cannot be dot, dash
 			if last == '.' || last == '-' {
-				return 0, uint8(l), false
+				return 0, uint8(l - longer), false
 			}
 			if last == '\\' { // Ok, escaped dot.
 				partlen++
 				break
 			}
 			if partlen > 63 || partlen == 0 {
-				return 0, uint8(l), false
+				return 0, uint8(l - longer), false
 			}
 			partlen = 0
 			labels++
 		}
 		last = c
 	}
-	return labels, uint8(l), ok
+	return labels, uint8(l - longer), ok
 }
 
 // IsFqdn checks if a domain name is fully qualified

dns.go

@@ -67,11 +67,11 @@ import (
 )
 
 const (
-	Year68            = 1 << 32 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
+	Year68         = 1 << 32 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
-	DefaultMsgSize    = 4096    // Standard default for larger than 512 packets.
+	DefaultMsgSize = 4096    // Standard default for larger than 512 packets.
-	UDPMsgSize = 512     // Default buffer size for servers receiving UDP packets.
+	UDPMsgSize     = 512     // Default buffer size for servers receiving UDP packets.
-	MaxMsgSize        = 65536   // Largest possible DNS packet.
+	MaxMsgSize     = 65536   // Largest possible DNS packet.
-	DefaultTtl        = 3600    // Default TTL.
+	DefaultTtl     = 3600    // Default TTL.
 )
 
 // Error represents a DNS error

msg.go

@@ -808,10 +808,10 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 				default:
 					consumed = 0 // TODO, maybe error?
 				}
-                                if off+rdlength-consumed > lenmsg {
+				if off+rdlength-consumed > lenmsg {
-                                        println("dns: failure unpacking base64")
+					println("dns: failure unpacking base64")
-                                        return lenmsg, false
+					return lenmsg, false
-                                }
+				}
 				s = unpackBase64(msg[off : off+rdlength-consumed])
 				off += rdlength - consumed
 			case "cdomain-name":

zscan.go

@@ -162,11 +162,13 @@ func parseZone(r io.Reader, f string, t chan Token, include int) {
 			case _OWNER:
 				h.Name = l.token
 				_, ld, ok := IsDomainName(l.token)
-                                if !ok {
+				if !ok {
 					t <- Token{Error: &ParseError{f, "bad owner name", l}}
 					return
 				}
-                                if h.Name[ld-1] != '.' {
+				println(l.token)
+				println(len(l.token), ld)
+				if h.Name[ld-1] != '.' {
 					h.Name += origin
 				}
 				st = _EXPECT_OWNER_BL