tidy up DNSServer fields

- make Zone, Iface and Upstream public - this is safe and makes sense
  since all are immutable, and the former two are passed to the
  constructor and are thus known anyway, and the latter is derived
  from external information
- remove IfaceName - we can just use Iface instead
- log Upstream on startup

nameserver/server.go

@@ -18,8 +18,7 @@ const (
 	DefaultCacheLen      = 8192               // default cache capacity
 	DefaultResolvWorkers = 8                  // default number of resolution workers
 	DefaultTimeout       = 5                  // default timeout for DNS resolutions
-	DefaultIfaceName     = "default interface"
-	DefaultResolvTries   = 3 // max # of times a worker tries to resolve a query
+	DefaultResolvTries   = 3                  // max # of times a worker tries to resolve a query
 )
 
 type DNSServerConfig struct {
@@ -68,32 +67,30 @@ func (proto dnsProtocol) GetNewClient(bufsize int) *dns.Client {
 }
 
 type DNSServer struct {
+	Zone        Zone
+	Iface       *net.Interface
+	Upstream    *dns.ClientConfig
 	udpSrv      *dns.Server
 	tcpSrv      *dns.Server
 	mdnsCli     *MDNSClient
 	mdnsSrv     *MDNSServer
 	cache       *Cache
-	zone        Zone
-	iface       *net.Interface
-	upstream    *dns.ClientConfig
 	timeout     int
 	udpBuf      int
 	listenersWg *sync.WaitGroup
 
 	Domain     string // the local domain
-	IfaceName  string // the interface where mDNS is working on
 	ListenAddr string // the address the server is listening at
 }
 
 // Creates a new DNS server
 func NewDNSServer(config DNSServerConfig, zone Zone, iface *net.Interface) (s *DNSServer, err error) {
 	s = &DNSServer{
-		zone:        zone,
-		iface:       iface,
+		Zone:        zone,
+		Iface:       iface,
 		listenersWg: new(sync.WaitGroup),
 
 		Domain:     DefaultLocalDomain,
-		IfaceName:  DefaultIfaceName,
 		ListenAddr: fmt.Sprintf(":%d", DefaultServerPort),
 	}
 
@@ -105,13 +102,13 @@ func NewDNSServer(config DNSServerConfig, zone Zone, iface *net.Interface) (s *D
 		s.Domain = config.LocalDomain
 	}
 	if config.UpstreamCfg != nil {
-		s.upstream = config.UpstreamCfg
+		s.Upstream = config.UpstreamCfg
 	} else {
 		cfgFile := DefaultCLICfgFile
 		if len(config.UpstreamCfgFile) > 0 {
 			cfgFile = config.UpstreamCfgFile
 		}
-		if s.upstream, err = dns.ClientConfigFromFile(cfgFile); err != nil {
+		if s.Upstream, err = dns.ClientConfigFromFile(cfgFile); err != nil {
 			return nil, err
 		}
 	}
@@ -125,13 +122,10 @@ func NewDNSServer(config DNSServerConfig, zone Zone, iface *net.Interface) (s *D
 	if err != nil {
 		return
 	}
-	s.mdnsSrv, err = NewMDNSServer(s.zone)
+	s.mdnsSrv, err = NewMDNSServer(s.Zone)
 	if err != nil {
 		return
 	}
-	if iface != nil {
-		s.IfaceName = iface.Name
-	}
 	cacheLen := DefaultCacheLen
 	if config.CacheLen > 0 {
 		cacheLen = config.CacheLen
@@ -146,8 +140,8 @@ func NewDNSServer(config DNSServerConfig, zone Zone, iface *net.Interface) (s *D
 	// (we use the same protocol for asking upstream servers)
 	mux := func(proto dnsProtocol) *dns.ServeMux {
 		m := dns.NewServeMux()
-		m.HandleFunc(s.Domain, s.queryHandler([]Lookup{s.zone, s.mdnsCli}, proto))
-		m.HandleFunc(RDNSDomain, s.rdnsHandler([]Lookup{s.zone, s.mdnsCli}, proto))
+		m.HandleFunc(s.Domain, s.queryHandler([]Lookup{s.Zone, s.mdnsCli}, proto))
+		m.HandleFunc(RDNSDomain, s.rdnsHandler([]Lookup{s.Zone, s.mdnsCli}, proto))
 		m.HandleFunc(".", s.notUsHandler(proto))
 		return m
 	}
@@ -160,10 +154,10 @@ func NewDNSServer(config DNSServerConfig, zone Zone, iface *net.Interface) (s *D
 
 // Start the DNS server
 func (s *DNSServer) Start() error {
-	Info.Printf("Using mDNS on %s", s.IfaceName)
-	err := s.mdnsCli.Start(s.iface)
+	Info.Printf("Using mDNS on %v", s.Iface)
+	err := s.mdnsCli.Start(s.Iface)
 	CheckFatal(err)
-	err = s.mdnsSrv.Start(s.iface, s.Domain)
+	err = s.mdnsSrv.Start(s.Iface, s.Domain)
 	CheckFatal(err)
 
 	s.listenersWg.Add(2)
@@ -198,9 +192,9 @@ func (s *DNSServer) Status() string {
 	var buf bytes.Buffer
 	fmt.Fprintln(&buf, "Local domain", s.Domain)
 	fmt.Fprintln(&buf, "Listen address", s.ListenAddr)
-	fmt.Fprintln(&buf, "mDNS interface", s.iface)
-	fmt.Fprintln(&buf, "Fallback DNS config", s.upstream)
-	fmt.Fprintf(&buf, "Zone database:\n%s", s.zone)
+	fmt.Fprintln(&buf, "mDNS interface", s.Iface)
+	fmt.Fprintln(&buf, "Fallback DNS config", s.Upstream)
+	fmt.Fprintf(&buf, "Zone database:\n%s", s.Zone)
 	return buf.String()
 }
 
@@ -334,8 +328,8 @@ func (s *DNSServer) notUsHandler(proto dnsProtocol) dns.HandlerFunc {
 		rcopy.SetEdns0(uint16(maxLen), false)
 
 		Debug.Printf("[dns msgid %d] Fallback query: %+v [%s, max:%d bytes]", rcopy.MsgHdr.Id, q, proto, maxLen)
-		for _, server := range s.upstream.Servers {
-			reply, _, err := dnsClient.Exchange(rcopy, fmt.Sprintf("%s:%s", server, s.upstream.Port))
+		for _, server := range s.Upstream.Servers {
+			reply, _, err := dnsClient.Exchange(rcopy, fmt.Sprintf("%s:%s", server, s.Upstream.Port))
 			if err != nil {
 				Debug.Printf("[dns msgid %d] Network error trying %s (%s)",
 					r.MsgHdr.Id, server, err)

weavedns/main.go

@@ -87,6 +87,7 @@ func main() {
 	if err != nil {
 		Error.Fatal("Failed to initialize the WeaveDNS server", err)
 	}
+	Info.Println("Upstream", srv.Upstream)
 
 	Debug.Printf("Starting the signals handler")
 	go handleSignals(srv)