Add .meship protocol support (#7)

pkg/meshname/server.go

@@ -64,9 +64,11 @@ func (s *MeshnameServer) Start() error {
 			NotifyStartedFunc: func(){ close(waitStarted) },
 		}
 		for tld, subnet := range s.networks {
-			dns.HandleFunc(tld, s.handleRequest)
+			dns.HandleFunc(tld, s.handleMeshnameRequest)
 			s.log.Debugln("Handling:", tld, subnet)
 		}
+		dns.HandleFunc("meship", s.handleMeshIPRequest)
+		s.log.Debugln("Handling: meship ::/0")
 		go func(){
 			if err := s.dnsServer.ListenAndServe(); err != nil {
 				s.log.Fatalln("MeshnameServer failed to start:", err)
@@ -88,7 +90,7 @@ func (s *MeshnameServer) ConfigureDNSRecords(dnsRecords map[string][]dns.RR) {
 	s.dnsRecordsLock.Unlock()
 }
 
-func (s *MeshnameServer) handleRequest(w dns.ResponseWriter, r *dns.Msg) {
+func (s *MeshnameServer) handleMeshnameRequest(w dns.ResponseWriter, r *dns.Msg) {
 	var remoteLookups = make(map[string][]dns.Question)
 	m := new(dns.Msg)
 	m.SetReply(r)
@@ -146,6 +148,35 @@ func (s *MeshnameServer) handleRequest(w dns.ResponseWriter, r *dns.Msg) {
 	}
 }
 
+func (s *MeshnameServer) handleMeshIPRequest(w dns.ResponseWriter, r *dns.Msg) {
+	m := new(dns.Msg)
+	m.SetReply(r)
+
+	for _, q := range r.Question {
+		labels := dns.SplitDomainName(q.Name)
+		// resolve only 2nd level domains and AAAA type
+		if len(labels) != 2 || q.Qtype != dns.TypeAAAA || q.Qclass != dns.ClassINET {
+			s.log.Debugln("Error: invalid resource requested")
+			continue
+		}
+		subDomain := labels[len(labels)-2]
+
+		if resolvedAddr, err := IPFromDomain(&subDomain); err == nil {
+			answer := new(dns.AAAA)
+			answer.Hdr = dns.RR_Header{Name: q.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: 3600}
+			answer.AAAA = resolvedAddr
+
+			m.Answer = append(m.Answer, answer)
+		} else {
+			s.log.Debugln(err)
+		}
+	}
+
+	if err := w.WriteMsg(m); err != nil {
+		s.log.Debugln("Error writing response:", err)
+	}
+}
+
 func (s *MeshnameServer) isRemoteLookupAllowed(addr net.Addr) bool {
 	// TODO prefix whitelists ?
 	if s.allowRemote {