Completely fix EDNS0

TODO

@@ -1,14 +1,13 @@
 Todo:
 * DNSSEC validation
 * NSEC(3) secure denial of existence
-* Unknown RRs
 * fix os.Erros usage, add DNSSEC related errors
 * AXFR/IXFR support
 * IDN?
+* Unknown RRs?
 * query-time, server in string ouput of dns.Msg
 
 Issues:
-* completely fix EDNS
 * shortened ipv6 addresses are not parsed correctly
 * quoted quotes in txt records
 * Convience functions?

_examples/q/q.go

@@ -15,12 +15,13 @@ import (
 
 func main() {
 	var dnssec *bool = flag.Bool("dnssec", false, "Set the DO (DNSSEC OK) bit and set the bufsize to 4096")
+        var port   *string = flag.String("port", "53", "Set the query port")
         flag.Usage = func() {
                 fmt.Fprintf(os.Stderr, "Usage: %s [@server] [qtype] [qclass] [name ...]\n", os.Args[0])
                 flag.PrintDefaults()
         }
 
-	nameserver := "127.0.0.1"       // Default nameserver
+	nameserver := "@127.0.0.1"       // Default nameserver
 	qtype := uint16(dns.TypeA)      // Default qtype
 	qclass := uint16(dns.ClassINET) // Default qclass
 	var qname []string
@@ -53,12 +54,14 @@ FLAGS:
 	}
 	r := new(resolver.Resolver)
         r.Timeout = 2
+        r.Port = *port
         r.Attempts = 1
 
 	qr := resolver.NewQuerier(r)
 	// @server may be a name, resolv that 
 	var err os.Error
-	_, addr, err := net.LookupHost(string([]byte(nameserver)[1:]))  //chop off @
+        nameserver = string([]byte(nameserver)[1:]) // chop off @
+	_, addr, err := net.LookupHost(nameserver)
         if err == nil {
                 r.Servers = addr
         } else {

dns.go

@@ -8,6 +8,7 @@
 // * 1982 - Serial Arithmetic
 // * 1034/1035
 // * 2671 - EDNS
+// * 3225 - DO bit (DNSSEC OK)
 // * 4033/4034/4035 - DNSSEC + validation functions
 // * 5011 - NSID
 // * IP6 support

edns.go

@@ -6,10 +6,10 @@ import (
 
 // EDNS0 Options and Do bit
 const (
-	OptionCodeLLQ  = 1 // Not used
-	OptionCodeUL   = 2 // Not used
-	OptionCodeNSID = 3 // NSID, RFC5001
-	_DO = 1 << 7 // dnssec ok
+	OptionCodeLLQ  = 1      // Not used
+	OptionCodeUL   = 2      // Not used
+	OptionCodeNSID = 3      // NSID, RFC5001
+	_DO            = 1 << 7 // dnssec ok
 )
 
 // An ENDS0 option rdata element.
@@ -70,19 +70,29 @@ func (rr *RR_OPT) UDPSize(size uint16, set bool) uint16 {
 	return rr.Hdr.Class
 }
 
+
+/* from RFC 3225
+             +0 (MSB)                +1 (LSB)
+      +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+   0: |   EXTENDED-RCODE      |       VERSION         |
+      +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+   2: |DO|                    Z                       |
+      +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+*/
+
 // Set/Get the DoBit 
 func (rr *RR_OPT) DoBit(do, set bool) bool {
-	// rr.TTL last 2 bytes, left most bit
-	// See line 239 in msg.go for TTL encoding
 	if set {
-		leftbyte := byte(rr.Hdr.Ttl >> 24)
-		leftbyte = leftbyte | _DO
-		rr.Hdr.Ttl = uint32(leftbyte << 24)
+		b1 := byte(rr.Hdr.Ttl >> 24)
+		b2 := byte(rr.Hdr.Ttl >> 16)
+		b3 := byte(rr.Hdr.Ttl >> 8)
+		b4 := byte(rr.Hdr.Ttl)
+		b3 |= _DO // Set it
+		rr.Hdr.Ttl = uint32(b1)<<24 | uint32(b2)<<16 | uint32(b3)<<8 | uint32(b4)
 		return true
 	} else {
-		// jaja?? TODO(MG)
-		leftbyte := byte(rr.Hdr.Ttl >> 24)
-		return leftbyte&_DO == 1
+		b3 := byte(rr.Hdr.Ttl >> 8)
+		return b3&_DO == _DO
 	}
 	return true // dead code, bug in Go
 }