Update fks-shield and remove ListenAndServeTsig

ListenAndServeTsig can be handled much more easier
if you create your own server object

ex/fks-shield/cache.go

@@ -31,6 +31,8 @@ type Cache struct {
 	*radix.Radix
 }
 
+// Make an as-is copy, except for the first two bytes, as these hold
+// the DNS id.
 func quickCopy(p []byte) []byte {
 	q := make([]byte, 2)
 	q = append(q, p[2:]...)

ex/fks-shield/shield.go

@@ -42,12 +42,6 @@ func serve(w dns.ResponseWriter, r *dns.Msg, c *Cache) {
 	}
 }
 
-func listenAndServe(add, net string) {
-	if err := dns.ListenAndServe(add, net, nil); err != nil {
-		log.Fatal("fks-shield: failed to setup %s %s", net, add)
-	}
-}
-
 func main() {
 	flag.Usage = func() {
 		flag.PrintDefaults()
@@ -55,11 +49,14 @@ func main() {
 	flag.Parse()
 
 	cache := NewCache()
-
 	dns.HandleFunc(".", func(w dns.ResponseWriter, r *dns.Msg) { serve(w, r, cache) })
 
-	go listenAndServe(*listen, "tcp")
-	go listenAndServe(*listen, "udp")
+	// Only listen on UDP
+	go func() {
+		if err := dns.ListenAndServe(*listen, "udp", nil); err != nil {
+			log.Fatal("fks-shield: failed to setup %s %s", net, add)
+		}
+	}
 
 	sig := make(chan os.Signal)
 forever:

ex/fksd/cmds/config.mkd

@@ -8,6 +8,7 @@ We have defined the following groups:
 * `SYSTEM`: for system management?
 * `...`:    ...
 
+Better stuff then add and set
 
 # ZONE
 
@@ -27,7 +28,11 @@ Zones are listed in the additional section of the reply packet
 
 # USER
 
-    USER. TXT   "ADD miekg base64-tsig-secret"
+    USER. TXT   "ADD miekg"
     USER. TXT   "DROP miekg"
+    USER. TXT   "ADDTSIG miekg base64-tsig-secret"
     USER. TXT   "ADDPOWER miekg list"   // list/write/drop
     USER. TXT   "DROPPOWER miekg list"
+
+
+The config is internally stored in some memory structure 

server.go

@@ -93,14 +93,6 @@ func ListenAndServe(addr string, network string, handler Handler) error {
 	return server.ListenAndServe()
 }
 
-// Start a server on addresss and network speficied. Use the tsig
-// secrets for Tsig validation. 
-// Invoke handler for any incoming queries.
-func ListenAndServeTsig(addr string, network string, handler Handler, tsig map[string]string) error {
-	server := &Server{Addr: addr, Net: network, Handler: handler, TsigSecret: tsig}
-	return server.ListenAndServe()
-}
-
 func (mux *ServeMux) match(zone string, t uint16) Handler {
 	// Exact match
 	zone = toRadixName(zone)