.github/workflows: bump go version to 1.21.x

By filtering the interfaces by MAC address instead of name.

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["windows-latest", "ubuntu-latest", "macOS-latest"]
-        go: ["1.20.x"]
+        go: ["1.21.x"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3

.gitignore

@@ -3,3 +3,12 @@ gon.hcl
 
 /Build
 .DS_Store
+
+# Release folder
+dist/
+
+# Binaries
+ctrld-*
+
+# generated file
+cmd/cli/rsrc_*.syso

README.md

@@ -10,7 +10,8 @@ A highly configurable DNS forwarding proxy with support for:
 - Multiple network policy driven DNS query steering
 - Policy driven domain based "split horizon" DNS with wildcard support
 - Integrations with common router vendors and firmware
-- LAN client discovery via DHCP, mDNS, and ARP
+- LAN client discovery via DHCP, mDNS, ARP, NDP, hosts file parsing
+- Prometheus metrics exporter 
 
 ## TLDR
 Proxy legacy DNS traffic to secure DNS upstreams in highly configurable ways. 
@@ -61,7 +62,7 @@ $ docker pull controldns/ctrld
 Alternatively, if you know what you're doing you can download pre-compiled binaries from the [Releases](https://github.com/Control-D-Inc/ctrld/releases) section for the appropriate platform. 
 
 ## Build
-Lastly, you can build `ctrld` from source which requires `go1.19+`:
+Lastly, you can build `ctrld` from source which requires `go1.21+`:
 
 ```shell
 $ go build ./cmd/ctrld
@@ -232,7 +233,6 @@ See [Contribution Guideline](./docs/contributing.md)
 
 ## Roadmap
 The following functionality is on the roadmap and will be available in future releases. 
-- Prometheus metrics exporter 
 - DNS intercept mode
 - Direct listener mode
 - Support for more routers (let us know which ones)

client_info.go

@@ -18,4 +18,5 @@ type LeaseFileFormat string
 const (
 	Dnsmasq  LeaseFileFormat = "dnsmasq"
 	IscDhcpd LeaseFileFormat = "isc-dhcpd"
+	KeaDHCP4 LeaseFileFormat = "kea-dhcp4"
 )

cmd/cli/cli.go

@@ -50,9 +50,10 @@ var (
 )
 
 var (
-	v                 = viper.NewWithOptions(viper.KeyDelimiter("::"))
-	defaultConfigFile = "ctrld.toml"
-	rootCertPool      *x509.CertPool
+	v                    = viper.NewWithOptions(viper.KeyDelimiter("::"))
+	defaultConfigFile    = "ctrld.toml"
+	rootCertPool         *x509.CertPool
+	errSelfCheckNoAnswer = errors.New("no answer from ctrld listener")
 )
 
 var basicModeFlags = []string{"listen", "primary_upstream", "secondary_upstream", "domains"}
@@ -258,6 +259,16 @@ func initCLI() {
 				return
 			}
 
+			status, err := s.Status()
+			isCtrldInstalled := !errors.Is(err, service.ErrNotInstalled)
+
+			// If pin code was set, do not allow running start command.
+			if status == service.StatusRunning {
+				if err := checkDeactivationPin(s); isCheckDeactivationPinErr(err) {
+					os.Exit(deactivationPinInvalidExitCode)
+				}
+			}
+
 			if router.Name() != "" && iface != "" {
 				mainLog.Load().Debug().Msg("cleaning up router before installing")
 				_ = p.router.Cleanup()
@@ -266,7 +277,22 @@ func initCLI() {
 			tasks := []task{
 				{s.Stop, false},
 				{func() error { return doGenerateNextDNSConfig(nextdns) }, true},
-				{s.Uninstall, false},
+				{func() error { return ensureUninstall(s) }, false},
+				{func() error {
+					// If ctrld is installed, we should not save current DNS settings, because:
+					//
+					// - The DNS settings was being set by ctrld already.
+					// - We could not determine the state of DNS settings before installing ctrld.
+					if isCtrldInstalled {
+						return nil
+					}
+
+					// Save current DNS so we can restore later.
+					withEachPhysicalInterfaces("", "save DNS settings", func(i *net.Interface) error {
+						return saveCurrentStaticDNS(i)
+					})
+					return nil
+				}, false},
 				{s.Install, false},
 				{s.Start, true},
 				// Note that startCmd do not actually write ControlD config, but the config file was
@@ -280,17 +306,40 @@ func initCLI() {
 					return
 				}
 
-				status := selfCheckStatus(s)
-				switch status {
-				case service.StatusRunning:
+				ok, status, err := selfCheckStatus(s)
+				switch {
+				case ok && status == service.StatusRunning:
 					mainLog.Load().Notice().Msg("Service started")
 				default:
 					marker := bytes.Repeat([]byte("="), 32)
-					mainLog.Load().Error().Msg("ctrld service may not have started due to an error or misconfiguration, service log:")
-					_, _ = mainLog.Load().Write(marker)
-					for msg := range runCmdLogCh {
-						_, _ = mainLog.Load().Write([]byte(msg))
+					// If ctrld service is not running, emitting log obtained from ctrld process.
+					if status != service.StatusRunning {
+						mainLog.Load().Error().Msg("ctrld service may not have started due to an error or misconfiguration, service log:")
+						_, _ = mainLog.Load().Write(marker)
+						haveLog := false
+						for msg := range runCmdLogCh {
+							_, _ = mainLog.Load().Write([]byte(msg))
+							haveLog = true
+						}
+						// If we're unable to get log from "ctrld run", notice users about it.
+						if !haveLog {
+							mainLog.Load().Write([]byte(`<no log output is obtained from ctrld process>"`))
+						}
 					}
+					// Report any error if occurred.
+					if err != nil {
+						_, _ = mainLog.Load().Write(marker)
+						msg := fmt.Sprintf("An error occurred while performing test query: %s", err)
+						mainLog.Load().Write([]byte(msg))
+					}
+					// If ctrld service is running but selfCheckStatus failed, it could be related
+					// to user's system firewall configuration, notice users about it.
+					if status == service.StatusRunning {
+						_, _ = mainLog.Load().Write(marker)
+						mainLog.Load().Write([]byte(`ctrld service was running, but a DNS query could not be sent to its listener`))
+						mainLog.Load().Write([]byte(`Please check your system firewall if it is configured to block/intercept/redirect DNS queries`))
+					}
+
 					_, _ = mainLog.Load().Write(marker)
 					uninstall(p, s)
 					os.Exit(1)
@@ -364,6 +413,9 @@ func initCLI() {
 				return
 			}
 			initLogging()
+			if err := checkDeactivationPin(s); isCheckDeactivationPinErr(err) {
+				os.Exit(deactivationPinInvalidExitCode)
+			}
 			if doTasks([]task{{s.Stop, true}}) {
 				p.router.Cleanup()
 				p.resetDNS()
@@ -372,6 +424,8 @@ func initCLI() {
 		},
 	}
 	stopCmd.Flags().StringVarP(&iface, "iface", "", "", `Reset DNS setting for iface, "auto" means the default interface gateway`)
+	stopCmd.Flags().Int64VarP(&deactivationPin, "pin", "", defaultDeactivationPin, `Pin code for stopping ctrld`)
+	_ = stopCmd.Flags().MarkHidden("pin")
 
 	restartCmd := &cobra.Command{
 		PreRun: func(cmd *cobra.Command, args []string) {
@@ -518,10 +572,15 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 			if iface == "" {
 				iface = "auto"
 			}
+			if err := checkDeactivationPin(s); isCheckDeactivationPinErr(err) {
+				os.Exit(deactivationPinInvalidExitCode)
+			}
 			uninstall(p, s)
 		},
 	}
 	uninstallCmd.Flags().StringVarP(&iface, "iface", "", "", `Reset DNS setting for iface, use "auto" for the default gateway interface`)
+	uninstallCmd.Flags().Int64VarP(&deactivationPin, "pin", "", defaultDeactivationPin, `Pin code for uninstalling ctrld`)
+	_ = uninstallCmd.Flags().MarkHidden("pin")
 
 	listIfacesCmd := &cobra.Command{
 		Use:   "list",
@@ -719,6 +778,10 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 				sort.Strings(s)
 				return s
 			}
+			// If metrics is enabled, server set this for all clients, so we can check only the first one.
+			// Ideally, we may have a field in response to indicate that query count should be shown, but
+			// it would break earlier version of ctrld, which only look list of clients in response.
+			withQueryCount := len(clients) > 0 && clients[0].IncludeQueryCount
 			data := make([][]string, len(clients))
 			for i, c := range clients {
 				row := []string{
@@ -727,10 +790,17 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 					c.Mac,
 					strings.Join(map2Slice(c.Source), ","),
 				}
+				if withQueryCount {
+					row = append(row, strconv.FormatInt(c.QueryCount, 10))
+				}
 				data[i] = row
 			}
 			table := tablewriter.NewWriter(os.Stdout)
-			table.SetHeader([]string{"IP", "Hostname", "Mac", "Discovered"})
+			headers := []string{"IP", "Hostname", "Mac", "Discovered"}
+			if withQueryCount {
+				headers = append(headers, "Queries")
+			}
+			table.SetHeader(headers)
 			table.SetAutoFormatHeaders(false)
 			table.AppendBulk(data)
 			table.Render()
@@ -753,6 +823,11 @@ func isMobile() bool {
 	return runtime.GOOS == "android" || runtime.GOOS == "ios"
 }
 
+// isAndroid reports whether the current OS is Android.
+func isAndroid() bool {
+	return runtime.GOOS == "android"
+}
+
 // RunCobraCommand runs ctrld cli.
 func RunCobraCommand(cmd *cobra.Command) {
 	noConfigStart = isNoConfigStart(cmd)
@@ -771,11 +846,20 @@ func RunMobile(appConfig *AppConfig, appCallback *AppCallback, stopCh chan struc
 	homedir = appConfig.HomeDir
 	verbose = appConfig.Verbose
 	cdUID = appConfig.CdUID
-	cdUpstreamProto = ctrld.ResolverTypeDOH
+	cdUpstreamProto = appConfig.UpstreamProto
 	logPath = appConfig.LogPath
 	run(appCallback, stopCh)
 }
 
+// CheckDeactivationPin checks if deactivation pin is valid
+func CheckDeactivationPin(pin int64) int {
+	deactivationPin = pin
+	if err := checkDeactivationPin(nil); isCheckDeactivationPinErr(err) {
+		return deactivationPinInvalidExitCode
+	}
+	return 0
+}
+
 // run runs ctrld cli with given app callback and stop channel.
 func run(appCallback *AppCallback, stopCh chan struct{}) {
 	if stopCh == nil {
@@ -1155,6 +1239,18 @@ func processNoConfigFlags(noConfigStart bool) {
 	v.Set("upstream", upstream)
 }
 
+// defaultDeactivationPin is the default value for cdDeactivationPin.
+// If cdDeactivationPin equals to this default, it means the pin code is not set from Control D API.
+const defaultDeactivationPin = -1
+
+// cdDeactivationPin is used in cd mode to decide whether stop and uninstall commands can be run.
+var cdDeactivationPin int64 = defaultDeactivationPin
+
+// deactivationPinNotSet reports whether cdDeactivationPin was not set by processCDFlags.
+func deactivationPinNotSet() bool {
+	return cdDeactivationPin == defaultDeactivationPin
+}
+
 func processCDFlags(cfg *ctrld.Config) error {
 	logger := mainLog.Load().With().Str("mode", "cd").Logger()
 	logger.Info().Msgf("fetching Controld D configuration from API: %s", cdUID)
@@ -1179,6 +1275,11 @@ func processCDFlags(cfg *ctrld.Config) error {
 		return err
 	}
 
+	if resolverConfig.DeactivationPin != nil {
+		logger.Debug().Msg("saving deactivation pin")
+		cdDeactivationPin = *resolverConfig.DeactivationPin
+	}
+
 	logger.Info().Msg("generating ctrld config from Control-D configuration")
 
 	*cfg = ctrld.Config{}
@@ -1294,41 +1395,44 @@ func defaultIfaceName() string {
 	return dri
 }
 
-func selfCheckStatus(s service.Service) service.Status {
+// selfCheckStatus performs the end-to-end DNS test by sending query to ctrld listener.
+// It returns a boolean to indicate whether the check is succeeded, the actual status
+// of ctrld service, and an additional error if any.
+func selfCheckStatus(s service.Service) (bool, service.Status, error) {
 	status, err := s.Status()
 	if err != nil {
 		mainLog.Load().Warn().Err(err).Msg("could not get service status")
-		return status
+		return false, service.StatusUnknown, err
 	}
 	// If ctrld is not running, do nothing, just return the status as-is.
 	if status != service.StatusRunning {
-		return status
+		return false, status, nil
 	}
 	dir, err := socketDir()
 	if err != nil {
 		mainLog.Load().Error().Err(err).Msg("failed to check ctrld listener status: could not get home directory")
-		return service.StatusUnknown
+		return false, status, err
 	}
 	mainLog.Load().Debug().Msg("waiting for ctrld listener to be ready")
 	cc := newSocketControlClient(s, dir)
 	if cc == nil {
-		return service.StatusUnknown
+		return false, status, errors.New("could not connect to control server")
 	}
 
 	resp, err := cc.post(startedPath, nil)
 	if err != nil {
 		mainLog.Load().Error().Err(err).Msg("failed to connect to control server")
-		return service.StatusUnknown
+		return false, status, err
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		mainLog.Load().Error().Msg("ctrld listener is not ready")
-		return service.StatusUnknown
+		return false, status, errors.New("ctrld listener is not ready")
 	}
 
 	// Not a ctrld upstream, return status as-is.
 	if cfg.FirstUpstream().VerifyDomain() == "" {
-		return status
+		return true, status, nil
 	}
 
 	mainLog.Load().Debug().Msg("ctrld listener is ready")
@@ -1353,12 +1457,12 @@ func selfCheckStatus(s service.Service) service.Status {
 	domain := cfg.FirstUpstream().VerifyDomain()
 	if domain == "" {
 		// Nothing to do, return the status as-is.
-		return status
+		return true, status, nil
 	}
 	watcher, err := fsnotify.NewWatcher()
 	if err != nil {
 		mainLog.Load().Error().Err(err).Msg("could not watch config change")
-		return service.StatusUnknown
+		return false, status, err
 	}
 	defer watcher.Close()
 
@@ -1397,14 +1501,18 @@ func selfCheckStatus(s service.Service) service.Status {
 		m := new(dns.Msg)
 		m.SetQuestion(domain+".", dns.TypeA)
 		m.RecursionDesired = true
-		r, _, err := c.ExchangeContext(ctx, m, net.JoinHostPort(lc.IP, strconv.Itoa(lc.Port)))
+		r, _, exErr := exchangeContextWithTimeout(c, time.Second, m, net.JoinHostPort(lc.IP, strconv.Itoa(lc.Port)))
 		if r != nil && r.Rcode == dns.RcodeSuccess && len(r.Answer) > 0 {
 			mainLog.Load().Debug().Msgf("self-check against %q succeeded", domain)
-			return status
+			return true, status, nil
+		}
+		// Return early if this is a connection refused.
+		if errConnectionRefused(exErr) {
+			return false, status, exErr
 		}
 		lastAnswer = r
-		lastErr = err
-		bo.BackOff(ctx, fmt.Errorf("ExchangeContext: %w", err))
+		lastErr = exErr
+		bo.BackOff(ctx, fmt.Errorf("ExchangeContext: %w", exErr))
 	}
 	mainLog.Load().Debug().Msgf("self-check against %q failed", domain)
 	lc := cfg.FirstListener()
@@ -1419,9 +1527,9 @@ func selfCheckStatus(s service.Service) service.Status {
 		for _, s := range strings.Split(lastAnswer.String(), "\n") {
 			mainLog.Load().Debug().Msgf("%s", s)
 		}
-		mainLog.Load().Debug().Msg(marker)
+		return false, status, errSelfCheckNoAnswer
 	}
-	return service.StatusUnknown
+	return false, status, lastErr
 }
 
 func userHomeDir() (string, error) {
@@ -1618,10 +1726,18 @@ type listenerConfigCheck struct {
 
 // mobileListenerPort returns hardcoded port for mobile platforms.
 func mobileListenerPort() int {
-	if runtime.GOOS == "ios" {
-		return 53
+	if isAndroid() {
+		return 5354
 	}
-	return 5354
+	return 53
+}
+
+// mobileListenerIp returns hardcoded listener ip for mobile platforms
+func mobileListenerIp() string {
+	if isAndroid() {
+		return "0.0.0.0"
+	}
+	return "127.0.0.1"
 }
 
 // updateListenerConfig updates the config for listeners if not defined,
@@ -1640,10 +1756,17 @@ func tryUpdateListenerConfig(cfg *ctrld.Config, infoLogger *zerolog.Logger, fata
 	lcc := make(map[string]*listenerConfigCheck)
 	cdMode := cdUID != ""
 	nextdnsMode := nextdns != ""
+	// For Windows server with local Dns server running, we can only try on random local IP.
+	hasLocalDnsServer := windowsHasLocalDnsServerRunning()
 	for n, listener := range cfg.Listener {
 		lcc[n] = &listenerConfigCheck{}
 		if listener.IP == "" {
 			listener.IP = "0.0.0.0"
+			if hasLocalDnsServer {
+				// Windows Server lies to us that we could listen on 0.0.0.0:53
+				// even there's a process already done that, stick to local IP only.
+				listener.IP = "127.0.0.1"
+			}
 			lcc[n].IP = true
 		}
 		if listener.Port == 0 {
@@ -1652,9 +1775,15 @@ func tryUpdateListenerConfig(cfg *ctrld.Config, infoLogger *zerolog.Logger, fata
 		}
 		// In cd mode, we always try to pick an ip:port pair to work.
 		// Same if nextdns resolver is used.
+		//
+		// Except on Windows Server with local Dns running,
+		// we could only listen on random local IP port 53.
 		if cdMode || nextdnsMode {
 			lcc[n].IP = true
 			lcc[n].Port = true
+			if hasLocalDnsServer {
+				lcc[n].Port = false
+			}
 		}
 		updated = updated || lcc[n].IP || lcc[n].Port
 	}
@@ -1670,9 +1799,8 @@ func tryUpdateListenerConfig(cfg *ctrld.Config, infoLogger *zerolog.Logger, fata
 				delete(cfg.Listener, k)
 			}
 		}
-		// In cd mode, always use 127.0.0.1:5354.
 		if cdMode {
-			firstLn.IP = "127.0.0.1" // Mobile platforms allows running listener only on loop back address.
+			firstLn.IP = mobileListenerIp()
 			firstLn.Port = mobileListenerPort()
 			// TODO: use clear(lcc) once upgrading to go 1.21
 			for k := range lcc {
@@ -1741,6 +1869,11 @@ func tryUpdateListenerConfig(cfg *ctrld.Config, infoLogger *zerolog.Logger, fata
 		tryAllPort53 := true
 		tryOldIPPort5354 := true
 		tryPort5354 := true
+		if hasLocalDnsServer {
+			tryAllPort53 = false
+			tryOldIPPort5354 = false
+			tryPort5354 = false
+		}
 		attempts := 0
 		maxAttempts := 10
 		for {
@@ -2026,3 +2159,103 @@ func noticeWritingControlDConfig() error {
 	}
 	return nil
 }
+
+// deactivationPinInvalidExitCode indicates exit code due to invalid pin code.
+const deactivationPinInvalidExitCode = 126
+
+// errInvalidDeactivationPin indicates that the deactivation pin is invalid.
+var errInvalidDeactivationPin = errors.New("deactivation pin is invalid")
+
+// errRequiredDeactivationPin indicates that the deactivation pin is required but not provided by users.
+var errRequiredDeactivationPin = errors.New("deactivation pin is required to stop or uninstall the service")
+
+// checkDeactivationPin validates if the deactivation pin matches one in ControlD config.
+func checkDeactivationPin(s service.Service) error {
+	dir, err := socketDir()
+	if err != nil {
+		mainLog.Load().Err(err).Msg("could not check deactivation pin")
+		return err
+	}
+	var cc *controlClient
+	if s == nil {
+		cc = newControlClient(filepath.Join(dir, ctrldControlUnixSock))
+	} else {
+		cc = newSocketControlClient(s, dir)
+	}
+	if cc == nil {
+		return nil // ctrld is not running.
+	}
+	data, _ := json.Marshal(&deactivationRequest{Pin: deactivationPin})
+	resp, _ := cc.post(deactivationPath, bytes.NewReader(data))
+	if resp != nil {
+		switch resp.StatusCode {
+		case http.StatusBadRequest:
+			mainLog.Load().Error().Msg(errRequiredDeactivationPin.Error())
+			return errRequiredDeactivationPin // pin is required
+		case http.StatusOK:
+			return nil // valid pin
+		case http.StatusNotFound:
+			return nil // the server is running older version of ctrld
+		}
+	}
+	mainLog.Load().Error().Msg(errInvalidDeactivationPin.Error())
+	return errInvalidDeactivationPin
+}
+
+// isCheckDeactivationPinErr reports whether there is an error during check deactivation pin process.
+func isCheckDeactivationPinErr(err error) bool {
+	return errors.Is(err, errInvalidDeactivationPin) || errors.Is(err, errRequiredDeactivationPin)
+}
+
+// ensureUninstall ensures that s.Uninstall will remove ctrld service from system completely.
+func ensureUninstall(s service.Service) error {
+	maxAttempts := 10
+	var err error
+	for i := 0; i < maxAttempts; i++ {
+		err = s.Uninstall()
+		if _, err := s.Status(); errors.Is(err, service.ErrNotInstalled) {
+			return nil
+		}
+		time.Sleep(time.Second)
+	}
+	return errors.Join(err, errors.New("uninstall failed"))
+}
+
+// exchangeContextWithTimeout wraps c.ExchangeContext with the given timeout.
+func exchangeContextWithTimeout(c *dns.Client, timeout time.Duration, msg *dns.Msg, addr string) (*dns.Msg, time.Duration, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	return c.ExchangeContext(ctx, msg, addr)
+}
+
+// powershell runs the given powershell command.
+func powershell(cmd string) ([]byte, error) {
+	out, err := exec.Command("powershell", "-Command", cmd).CombinedOutput()
+	return bytes.TrimSpace(out), err
+}
+
+// windowsHasLocalDnsServerRunning reports whether we are on Windows and having Dns server running.
+func windowsHasLocalDnsServerRunning() bool {
+	if runtime.GOOS == "windows" {
+		out, _ := powershell("Get-WindowsFeature -Name DNS")
+		if !bytes.Contains(bytes.ToLower(out), []byte("installed")) {
+			return false
+		}
+
+		_, err := powershell("Get-Process -Name DNS")
+		return err == nil
+	}
+	return false
+}
+
+// absHomeDir returns the absolute path to given filename using home directory as root dir.
+func absHomeDir(filename string) string {
+	if homedir != "" {
+		return filepath.Join(homedir, filename)
+	}
+	dir, err := userHomeDir()
+	if err != nil {
+		return filename
+	}
+	return filepath.Join(dir, filename)
+}

cmd/cli/control_client.go

@@ -27,3 +27,8 @@ func newControlClient(addr string) *controlClient {
 func (c *controlClient) post(path string, data io.Reader) (*http.Response, error) {
 	return c.c.Post("http://unix"+path, contentTypeJson, data)
 }
+
+// deactivationRequest represents request for validating deactivation pin.
+type deactivationRequest struct {
+	Pin int64 `json:"pin"`
+}

cmd/cli/control_server.go

@@ -10,14 +10,17 @@ import (
 	"sort"
 	"time"
 
+	dto "github.com/prometheus/client_model/go"
+
 	"github.com/Control-D-Inc/ctrld"
 )
 
 const (
-	contentTypeJson = "application/json"
-	listClientsPath = "/clients"
-	startedPath     = "/started"
-	reloadPath      = "/reload"
+	contentTypeJson  = "application/json"
+	listClientsPath  = "/clients"
+	startedPath      = "/started"
+	reloadPath       = "/reload"
+	deactivationPath = "/deactivation"
 )
 
 type controlServer struct {
@@ -66,6 +69,25 @@ func (p *prog) registerControlServerHandler() {
 		sort.Slice(clients, func(i, j int) bool {
 			return clients[i].IP.Less(clients[j].IP)
 		})
+		if p.cfg.Service.MetricsQueryStats {
+			for _, client := range clients {
+				client.IncludeQueryCount = true
+				dm := &dto.Metric{}
+				m, err := statsClientQueriesCount.MetricVec.GetMetricWithLabelValues(
+					client.IP.String(),
+					client.Mac,
+					client.Hostname,
+				)
+				if err != nil {
+					mainLog.Load().Debug().Err(err).Msgf("could not get metrics for client: %v", client)
+					continue
+				}
+				if err := m.Write(dm); err == nil {
+					client.QueryCount = int64(dm.Counter.GetValue())
+				}
+			}
+		}
+
 		if err := json.NewEncoder(w).Encode(&clients); err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
@@ -125,6 +147,30 @@ func (p *prog) registerControlServerHandler() {
 		// Otherwise, reload is done.
 		w.WriteHeader(http.StatusOK)
 	}))
+	p.cs.register(deactivationPath, http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
+		// Non-cd mode or pin code not set, always allowing deactivation.
+		if cdUID == "" || deactivationPinNotSet() {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+
+		var req deactivationRequest
+		if err := json.NewDecoder(request.Body).Decode(&req); err != nil {
+			w.WriteHeader(http.StatusPreconditionFailed)
+			mainLog.Load().Err(err).Msg("invalid deactivation request")
+			return
+		}
+
+		code := http.StatusForbidden
+		switch req.Pin {
+		case cdDeactivationPin:
+			code = http.StatusOK
+		case defaultDeactivationPin:
+			// If the pin code was set, but users do not provide --pin, return proper code to client.
+			code = http.StatusBadRequest
+		}
+		w.WriteHeader(code)
+	}))
 }
 
 func jsonResponse(next http.Handler) http.Handler {

cmd/cli/dns_proxy.go

@@ -54,6 +54,14 @@ type proxyRequest struct {
 	ufr            *upstreamForResult
 }
 
+// proxyResponse contains data for proxying a DNS response from upstream.
+type proxyResponse struct {
+	answer     *dns.Msg
+	cached     bool
+	clientInfo bool
+	upstream   string
+}
+
 // upstreamForResult represents the result of processing rules for a request.
 type upstreamForResult struct {
 	upstreams      []string
@@ -101,26 +109,49 @@ func (p *prog) serveDNS(listenerNum string) error {
 		fmtSrcToDest := fmtRemoteToLocal(listenerNum, ci.Hostname, remoteAddr.String())
 		t := time.Now()
 		ctrld.Log(ctx, mainLog.Load().Info(), "QUERY: %s: %s %s", fmtSrcToDest, dns.TypeToString[q.Qtype], domain)
-		res := p.upstreamFor(ctx, listenerNum, listenerConfig, remoteAddr, ci.Mac, domain)
+		ur := p.upstreamFor(ctx, listenerNum, listenerConfig, remoteAddr, ci.Mac, domain)
+
+		labelValues := make([]string, 0, len(statsQueriesCountLabels))
+		labelValues = append(labelValues, net.JoinHostPort(listenerConfig.IP, strconv.Itoa(listenerConfig.Port)))
+		labelValues = append(labelValues, ci.IP)
+		labelValues = append(labelValues, ci.Mac)
+		labelValues = append(labelValues, ci.Hostname)
+
 		var answer *dns.Msg
-		if !res.matched && listenerConfig.Restricted {
+		if !ur.matched && listenerConfig.Restricted {
 			ctrld.Log(ctx, mainLog.Load().Info(), "query refused, %s does not match any network policy", remoteAddr.String())
 			answer = new(dns.Msg)
 			answer.SetRcode(m, dns.RcodeRefused)
+			labelValues = append(labelValues, "") // no upstream
 		} else {
 			var failoverRcode []int
 			if listenerConfig.Policy != nil {
 				failoverRcode = listenerConfig.Policy.FailoverRcodeNumbers
 			}
-			answer = p.proxy(ctx, &proxyRequest{
+			pr := p.proxy(ctx, &proxyRequest{
 				msg:            m,
 				ci:             ci,
 				failoverRcodes: failoverRcode,
-				ufr:            res,
+				ufr:            ur,
 			})
+			answer = pr.answer
 			rtt := time.Since(t)
 			ctrld.Log(ctx, mainLog.Load().Debug(), "received response of %d bytes in %s", answer.Len(), rtt)
+			upstream := pr.upstream
+			switch {
+			case pr.cached:
+				upstream = "cache"
+			case pr.clientInfo:
+				upstream = "client_info_table"
+			}
+			labelValues = append(labelValues, upstream)
 		}
+		labelValues = append(labelValues, dns.TypeToString[q.Qtype])
+		labelValues = append(labelValues, dns.RcodeToString[answer.Rcode])
+		go func() {
+			p.WithLabelValuesInc(statsQueriesCount, labelValues...)
+			p.WithLabelValuesInc(statsClientQueriesCount, []string{ci.IP, ci.Mac, ci.Hostname}...)
+		}()
 		if err := w.WriteMsg(answer); err != nil {
 			ctrld.Log(ctx, mainLog.Load().Error().Err(err), "serveDNS: failed to send DNS response to client")
 		}
@@ -360,7 +391,7 @@ func (p *prog) proxyLanHostnameQuery(ctx context.Context, msg *dns.Msg) *dns.Msg
 	return nil
 }
 
-func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
+func (p *prog) proxy(ctx context.Context, req *proxyRequest) *proxyResponse {
 	var staleAnswer *dns.Msg
 	upstreams := req.ufr.upstreams
 	serveStaleCache := p.cache != nil && p.cfg.Service.CacheServeStale
@@ -370,6 +401,8 @@ func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
 		upstreams = []string{upstreamOS}
 	}
 
+	res := &proxyResponse{}
+
 	// LAN/PTR lookup flow:
 	//
 	// 1. If there's matching rule, follow it.
@@ -384,14 +417,18 @@ func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
 		case isPrivatePtrLookup(req.msg):
 			isLanOrPtrQuery = true
 			if answer := p.proxyPrivatePtrLookup(ctx, req.msg); answer != nil {
-				return answer
+				res.answer = answer
+				res.clientInfo = true
+				return res
 			}
 			upstreams, upstreamConfigs = p.upstreamsAndUpstreamConfigForLanAndPtr(upstreams, upstreamConfigs)
 			ctrld.Log(ctx, mainLog.Load().Debug(), "private PTR lookup, using upstreams: %v", upstreams)
 		case isLanHostnameQuery(req.msg):
 			isLanOrPtrQuery = true
 			if answer := p.proxyLanHostnameQuery(ctx, req.msg); answer != nil {
-				return answer
+				res.answer = answer
+				res.clientInfo = true
+				return res
 			}
 			upstreams, upstreamConfigs = p.upstreamsAndUpstreamConfigForLanAndPtr(upstreams, upstreamConfigs)
 			ctrld.Log(ctx, mainLog.Load().Debug(), "lan hostname lookup, using upstreams: %v", upstreams)
@@ -413,7 +450,9 @@ func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
 			if cachedValue.Expire.After(now) {
 				ctrld.Log(ctx, mainLog.Load().Debug(), "hit cached response")
 				setCachedAnswerTTL(answer, now, cachedValue.Expire)
-				return answer
+				res.answer = answer
+				res.cached = true
+				return res
 			}
 			staleAnswer = answer
 		}
@@ -475,7 +514,9 @@ func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
 				ctrld.Log(ctx, mainLog.Load().Debug(), "serving stale cached response")
 				now := time.Now()
 				setCachedAnswerTTL(staleAnswer, now, now.Add(staleTTL))
-				return staleAnswer
+				res.answer = staleAnswer
+				res.cached = true
+				return res
 			}
 			continue
 		}
@@ -509,12 +550,15 @@ func (p *prog) proxy(ctx context.Context, req *proxyRequest) *dns.Msg {
 			hostname = req.ci.Hostname
 		}
 		ctrld.Log(ctx, mainLog.Load().Info(), "REPLY: %s -> %s (%s): %s", upstreams[n], req.ufr.srcAddr, hostname, dns.RcodeToString[answer.Rcode])
-		return answer
+		res.answer = answer
+		res.upstream = upstreamConfig.Endpoint
+		return res
 	}
 	ctrld.Log(ctx, mainLog.Load().Error(), "all %v endpoints failed", upstreams)
 	answer := new(dns.Msg)
 	answer.SetRcode(req.msg, dns.RcodeServerFailure)
-	return answer
+	res.answer = answer
+	return res
 }
 
 func (p *prog) upstreamsAndUpstreamConfigForLanAndPtr(upstreams []string, upstreamConfigs []*ctrld.UpstreamConfig) ([]string, []*ctrld.UpstreamConfig) {

cmd/cli/dns_proxy_test.go

@@ -187,8 +187,8 @@ func TestCache(t *testing.T) {
 	got1 := prog.proxy(context.Background(), req1)
 	got2 := prog.proxy(context.Background(), req2)
 	assert.NotSame(t, got1, got2)
-	assert.Equal(t, answer1.Rcode, got1.Rcode)
-	assert.Equal(t, answer2.Rcode, got2.Rcode)
+	assert.Equal(t, answer1.Rcode, got1.answer.Rcode)
+	assert.Equal(t, answer2.Rcode, got2.answer.Rcode)
 }
 
 func Test_ipAndMacFromMsg(t *testing.T) {

cmd/cli/library.go

@@ -11,8 +11,9 @@ type AppCallback struct {
 
 // AppConfig allows overwriting ctrld cli flags from mobile platforms.
 type AppConfig struct {
-	CdUID   string
-	HomeDir string
-	Verbose int
-	LogPath string
+	CdUID         string
+	HomeDir       string
+	UpstreamProto string
+	Verbose       int
+	LogPath       string
 }

cmd/cli/main.go

@@ -34,6 +34,7 @@ var (
 	ifaceStartStop    string
 	nextdns           string
 	cdUpstreamProto   string
+	deactivationPin   int64
 
 	mainLog       atomic.Pointer[zerolog.Logger]
 	consoleWriter zerolog.ConsoleWriter

cmd/cli/metrics.go

@@ -0,0 +1,150 @@
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"net"
+	"net/http"
+	"runtime"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/prometheus/prom2json"
+)
+
+// metricsServer represents a server to expose Prometheus metrics via HTTP.
+type metricsServer struct {
+	server  *http.Server
+	mux     *http.ServeMux
+	reg     *prometheus.Registry
+	addr    string
+	started bool
+}
+
+// newMetricsServer returns new metrics server.
+func newMetricsServer(addr string, reg *prometheus.Registry) (*metricsServer, error) {
+	mux := http.NewServeMux()
+	ms := &metricsServer{
+		server: &http.Server{Handler: mux},
+		mux:    mux,
+		reg:    reg,
+	}
+	ms.addr = addr
+	ms.registerMetricsServerHandler()
+	return ms, nil
+}
+
+// register adds handlers for given pattern.
+func (ms *metricsServer) register(pattern string, handler http.Handler) {
+	ms.mux.Handle(pattern, handler)
+}
+
+// registerMetricsServerHandler adds handlers for metrics server.
+func (ms *metricsServer) registerMetricsServerHandler() {
+	ms.register("/metrics", promhttp.HandlerFor(
+		ms.reg,
+		promhttp.HandlerOpts{
+			EnableOpenMetrics: true,
+			Timeout:           10 * time.Second,
+		},
+	))
+	ms.register("/metrics/json", jsonResponse(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		g := prometheus.ToTransactionalGatherer(ms.reg)
+		mfs, done, err := g.Gather()
+		defer done()
+		if err != nil {
+			msg := "could not gather metrics"
+			mainLog.Load().Warn().Err(err).Msg(msg)
+			http.Error(w, msg, http.StatusInternalServerError)
+			return
+		}
+		result := make([]*prom2json.Family, 0, len(mfs))
+		for _, mf := range mfs {
+			result = append(result, prom2json.NewFamily(mf))
+		}
+		if err := json.NewEncoder(w).Encode(result); err != nil {
+			msg := "could not marshal metrics result"
+			mainLog.Load().Warn().Err(err).Msg(msg)
+			http.Error(w, msg, http.StatusInternalServerError)
+			return
+		}
+	})))
+}
+
+// start runs the metricsServer.
+func (ms *metricsServer) start() error {
+	listener, err := net.Listen("tcp", ms.addr)
+	if err != nil {
+		return err
+	}
+	go ms.server.Serve(listener)
+	ms.started = true
+	return nil
+}
+
+// stop shutdowns the metricsServer within 2 seconds timeout.
+func (ms *metricsServer) stop() error {
+	if !ms.started {
+		return nil
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*1)
+	defer cancel()
+	return ms.server.Shutdown(ctx)
+}
+
+// runMetricsServer initializes metrics stats and runs the metrics server if enabled.
+func (p *prog) runMetricsServer(ctx context.Context, reloadCh chan struct{}) {
+	if !p.metricsEnabled() {
+		return
+	}
+
+	// Reset all stats.
+	statsVersion.Reset()
+	statsQueriesCount.Reset()
+	statsClientQueriesCount.Reset()
+
+	reg := prometheus.NewRegistry()
+	// Register queries count stats if enabled.
+	if cfg.Service.MetricsQueryStats {
+		reg.MustRegister(statsQueriesCount)
+		reg.MustRegister(statsClientQueriesCount)
+	}
+
+	addr := p.cfg.Service.MetricsListener
+	ms, err := newMetricsServer(addr, reg)
+	if err != nil {
+		mainLog.Load().Warn().Err(err).Msg("could not create new metrics server")
+		return
+	}
+	// Only start listener address if defined.
+	if addr != "" {
+		// Go runtime stats.
+		reg.MustRegister(collectors.NewBuildInfoCollector())
+		reg.MustRegister(collectors.NewGoCollector(
+			collectors.WithGoCollectorRuntimeMetrics(collectors.MetricsAll),
+		))
+		// ctrld stats.
+		reg.MustRegister(statsVersion)
+		statsVersion.WithLabelValues(commit, runtime.Version(), curVersion()).Inc()
+		reg.MustRegister(statsTimeStart)
+		statsTimeStart.Set(float64(time.Now().Unix()))
+		mainLog.Load().Debug().Msgf("starting metrics server on: %s", addr)
+		if err := ms.start(); err != nil {
+			mainLog.Load().Warn().Err(err).Msg("could not start metrics server")
+			return
+		}
+	}
+
+	select {
+	case <-p.stopCh:
+	case <-ctx.Done():
+	case <-reloadCh:
+	}
+
+	if err := ms.stop(); err != nil {
+		mainLog.Load().Warn().Err(err).Msg("could not stop metrics server")
+		return
+	}
+}

cmd/cli/net.go

@@ -0,0 +1,34 @@
+package cli
+
+import "strings"
+
+// Copied from https://gist.github.com/Ultraporing/fe52981f678be6831f747c206a4861cb
+
+// Mac Address parts to look for, and identify non-physical devices. There may be more, update me!
+var macAddrPartsToFilter = []string{
+	"00:03:FF",       // Microsoft Hyper-V, Virtual Server, Virtual PC
+	"0A:00:27",       // VirtualBox
+	"00:00:00:00:00", // Teredo Tunneling Pseudo-Interface
+	"00:50:56",       // VMware ESX 3, Server, Workstation, Player
+	"00:1C:14",       // VMware ESX 3, Server, Workstation, Player
+	"00:0C:29",       // VMware ESX 3, Server, Workstation, Player
+	"00:05:69",       // VMware ESX 3, Server, Workstation, Player
+	"00:1C:42",       // Microsoft Hyper-V, Virtual Server, Virtual PC
+	"00:0F:4B",       // Virtual Iron 4
+	"00:16:3E",       // Red Hat Xen, Oracle VM, XenSource, Novell Xen
+	"08:00:27",       // Sun xVM VirtualBox
+	"7A:79",          // Hamachi
+}
+
+// Filters the possible physical interface address by comparing it to known popular VM Software addresses
+// and Teredo Tunneling Pseudo-Interface.
+//
+//lint:ignore U1000 use in net_windows.go
+func isPhysicalInterface(addr string) bool {
+	for _, macPart := range macAddrPartsToFilter {
+		if strings.HasPrefix(strings.ToLower(addr), strings.ToLower(macPart)) {
+			return false
+		}
+	}
+	return true
+}

cmd/cli/net_darwin.go

@@ -42,3 +42,21 @@ func networkServiceName(ifaceName string, r io.Reader) string {
 	}
 	return ""
 }
+
+// validInterface reports whether the *net.Interface is a valid one, which includes:
+//
+// - en0: physical wireless
+// - en1: Thunderbolt 1
+// - en2: Thunderbolt 2
+// - en3: Thunderbolt 3
+// - en4: Thunderbolt 4
+//
+// For full list, see: https://unix.stackexchange.com/questions/603506/what-are-these-ifconfig-interfaces-on-macos
+func validInterface(iface *net.Interface) bool {
+	switch iface.Name {
+	case "en0", "en1", "en2", "en3", "en4":
+		return true
+	default:
+		return false
+	}
+}

cmd/cli/net_others.go

@@ -1,7 +1,9 @@
-//go:build !darwin
+//go:build !darwin && !windows
 
 package cli
 
 import "net"
 
 func patchNetIfaceName(iface *net.Interface) error { return nil }
+
+func validInterface(iface *net.Interface) bool { return true }

cmd/cli/net_windows.go

@@ -0,0 +1,21 @@
+package cli
+
+import (
+	"net"
+)
+
+func patchNetIfaceName(iface *net.Interface) error {
+	return nil
+}
+
+// validInterface reports whether the *net.Interface is a valid one.
+// On Windows, only physical interfaces are considered valid.
+func validInterface(iface *net.Interface) bool {
+	if iface == nil {
+		return false
+	}
+	if isPhysicalInterface(iface.HardwareAddr.String()) {
+		return true
+	}
+	return false
+}

cmd/cli/os_darwin.go

@@ -1,6 +1,9 @@
 package cli
 
 import (
+	"bufio"
+	"bytes"
+	"fmt"
 	"net"
 	"os/exec"
 
@@ -34,22 +37,23 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 	cmd := "networksetup"
 	args := []string{"-setdnsservers", iface.Name}
 	args = append(args, nameservers...)
-
-	if err := exec.Command(cmd, args...).Run(); err != nil {
-		mainLog.Load().Error().Err(err).Msgf("setDNS failed, ips = %q", nameservers)
-		return err
+	if out, err := exec.Command(cmd, args...).CombinedOutput(); err != nil {
+		return fmt.Errorf("%v: %w", string(out), err)
 	}
 	return nil
 }
 
 // TODO(cuonglm): use system API
 func resetDNS(iface *net.Interface) error {
+	if ns := savedStaticNameservers(iface); len(ns) > 0 {
+		if err := setDNS(iface, ns); err == nil {
+			return nil
+		}
+	}
 	cmd := "networksetup"
 	args := []string{"-setdnsservers", iface.Name, "empty"}
-
-	if err := exec.Command(cmd, args...).Run(); err != nil {
-		mainLog.Load().Error().Err(err).Msgf("resetDNS failed")
-		return err
+	if out, err := exec.Command(cmd, args...).CombinedOutput(); err != nil {
+		return fmt.Errorf("%v: %w", string(out), err)
 	}
 	return nil
 }
@@ -57,3 +61,22 @@ func resetDNS(iface *net.Interface) error {
 func currentDNS(_ *net.Interface) []string {
 	return resolvconffile.NameServers("")
 }
+
+// currentStaticDNS returns the current static DNS settings of given interface.
+func currentStaticDNS(iface *net.Interface) ([]string, error) {
+	cmd := "networksetup"
+	args := []string{"-getdnsservers", iface.Name}
+	out, err := exec.Command(cmd, args...).Output()
+	if err != nil {
+		return nil, err
+	}
+	scanner := bufio.NewScanner(bytes.NewReader(out))
+	var ns []string
+	for scanner.Scan() {
+		line := scanner.Text()
+		if ip := net.ParseIP(line); ip != nil {
+			ns = append(ns, ip.String())
+		}
+	}
+	return ns, nil
+}

cmd/cli/os_freebsd.go

@@ -66,3 +66,8 @@ func resetDNS(iface *net.Interface) error {
 func currentDNS(_ *net.Interface) []string {
 	return resolvconffile.NameServers("")
 }
+
+// currentStaticDNS returns the current static DNS settings of given interface.
+func currentStaticDNS(iface *net.Interface) ([]string, error) {
+	return currentDNS(iface), nil
+}

cmd/cli/os_linux.go

@@ -9,12 +9,10 @@ import (
 	"net"
 	"net/netip"
 	"os/exec"
-	"path/filepath"
 	"strings"
 	"syscall"
 	"time"
 
-	"github.com/fsnotify/fsnotify"
 	"github.com/insomniacslk/dhcp/dhcpv4/nclient4"
 	"github.com/insomniacslk/dhcp/dhcpv6"
 	"github.com/insomniacslk/dhcp/dhcpv6/client6"
@@ -25,11 +23,6 @@ import (
 	"github.com/Control-D-Inc/ctrld/internal/resolvconffile"
 )
 
-const (
-	resolvConfPath            = "/etc/resolv.conf"
-	resolvConfBackupFailedMsg = "open /etc/resolv.pre-ctrld-backup.conf: read-only file system"
-)
-
 // allocate loopback ip
 // sudo ip a add 127.0.0.2/24 dev lo
 func allocateIP(ip string) error {
@@ -69,12 +62,6 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 		Nameservers:   ns,
 		SearchDomains: []dnsname.FQDN{},
 	}
-	defer func() {
-		if r.Mode() == "direct" {
-			go watchResolveConf(osConfig)
-		}
-	}()
-
 	trySystemdResolve := false
 	for i := 0; i < maxSetDNSAttempts; i++ {
 		if err := r.SetDNS(osConfig); err != nil {
@@ -203,6 +190,11 @@ func currentDNS(iface *net.Interface) []string {
 	return nil
 }
 
+// currentStaticDNS returns the current static DNS settings of given interface.
+func currentStaticDNS(iface *net.Interface) ([]string, error) {
+	return currentDNS(iface), nil
+}
+
 func getDNSByResolvectl(iface string) []string {
 	b, err := exec.Command("resolvectl", "dns", "-i", iface).Output()
 	if err != nil {
@@ -309,59 +301,3 @@ func sliceIndex[S ~[]E, E comparable](s S, v E) int {
 	}
 	return -1
 }
-
-// watchResolveConf watches any changes to /etc/resolv.conf file,
-// and reverting to the original config set by ctrld.
-func watchResolveConf(oc dns.OSConfig) {
-	mainLog.Load().Debug().Msg("start watching /etc/resolv.conf file")
-	watcher, err := fsnotify.NewWatcher()
-	if err != nil {
-		mainLog.Load().Warn().Err(err).Msg("could not create watcher for /etc/resolv.conf")
-		return
-	}
-
-	// We watch /etc instead of /etc/resolv.conf directly,
-	// see: https://github.com/fsnotify/fsnotify#watching-a-file-doesnt-work-well
-	watchDir := filepath.Dir(resolvConfPath)
-	if err := watcher.Add(watchDir); err != nil {
-		mainLog.Load().Warn().Err(err).Msg("could not add /etc/resolv.conf to watcher list")
-		return
-	}
-
-	r, err := dns.NewOSConfigurator(func(format string, args ...any) {}, "lo") // interface name does not matter.
-	if err != nil {
-		mainLog.Load().Error().Err(err).Msg("failed to create DNS OS configurator")
-		return
-	}
-
-	for {
-		select {
-		case event, ok := <-watcher.Events:
-			if !ok {
-				return
-			}
-			if event.Name != resolvConfPath { // skip if not /etc/resolv.conf changes.
-				continue
-			}
-			if event.Has(fsnotify.Write) || event.Has(fsnotify.Create) {
-				mainLog.Load().Debug().Msg("/etc/resolv.conf changes detected, reverting to ctrld setting")
-				if err := watcher.Remove(watchDir); err != nil {
-					mainLog.Load().Error().Err(err).Msg("failed to pause watcher")
-					continue
-				}
-				if err := r.SetDNS(oc); err != nil {
-					mainLog.Load().Error().Err(err).Msg("failed to revert /etc/resolv.conf changes")
-				}
-				if err := watcher.Add(watchDir); err != nil {
-					mainLog.Load().Error().Err(err).Msg("failed to continue running watcher")
-					return
-				}
-			}
-		case err, ok := <-watcher.Errors:
-			if !ok {
-				return
-			}
-			mainLog.Load().Err(err).Msg("could not get event for /etc/resolv.conf")
-		}
-	}
-}

cmd/cli/os_windows.go

@@ -2,21 +2,56 @@ package cli
 
 import (
 	"errors"
+	"fmt"
 	"net"
+	"os"
 	"os/exec"
 	"strconv"
+	"strings"
+	"sync"
 
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 
 	ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
 )
 
+const (
+	forwardersFilename       = ".forwarders.txt"
+	v4InterfaceKeyPathFormat = `HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\`
+	v6InterfaceKeyPathFormat = `HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\Interfaces\`
+)
+
+var (
+	setDNSOnce   sync.Once
+	resetDNSOnce sync.Once
+)
+
 func setDNS(iface *net.Interface, nameservers []string) error {
 	if len(nameservers) == 0 {
 		return errors.New("empty DNS nameservers")
 	}
+	setDNSOnce.Do(func() {
+		// If there's a Dns server running, that means we are on AD with Dns feature enabled.
+		// Configuring the Dns server to forward queries to ctrld instead.
+		if windowsHasLocalDnsServerRunning() {
+			file := absHomeDir(forwardersFilename)
+			if data, _ := os.ReadFile(file); len(data) > 0 {
+				if err := removeDnsServerForwarders(strings.Split(string(data), ",")); err != nil {
+					mainLog.Load().Error().Err(err).Msg("could not remove current forwarders settings")
+				} else {
+					mainLog.Load().Debug().Msg("removed current forwarders settings.")
+				}
+			}
+			if err := os.WriteFile(file, []byte(strings.Join(nameservers, ",")), 0600); err != nil {
+				mainLog.Load().Warn().Err(err).Msg("could not save forwarders settings")
+			}
+			if err := addDnsServerForwarders(nameservers); err != nil {
+				mainLog.Load().Warn().Err(err).Msg("could not set forwarders settings")
+			}
+		}
+	})
 	primaryDNS := nameservers[0]
-	if err := setPrimaryDNS(iface, primaryDNS); err != nil {
+	if err := setPrimaryDNS(iface, primaryDNS, true); err != nil {
 		return err
 	}
 	if len(nameservers) > 1 {
@@ -28,20 +63,64 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 
 // TODO(cuonglm): should we use system API?
 func resetDNS(iface *net.Interface) error {
+	resetDNSOnce.Do(func() {
+		// See corresponding comment in setDNS.
+		if windowsHasLocalDnsServerRunning() {
+			file := absHomeDir(forwardersFilename)
+			content, err := os.ReadFile(file)
+			if err != nil {
+				mainLog.Load().Error().Err(err).Msg("could not read forwarders settings")
+				return
+			}
+			nameservers := strings.Split(string(content), ",")
+			if err := removeDnsServerForwarders(nameservers); err != nil {
+				mainLog.Load().Error().Err(err).Msg("could not remove forwarders settings")
+				return
+			}
+		}
+	})
+
+	// Restoring ipv6 first.
 	if ctrldnet.SupportsIPv6ListenLocal() {
 		if output, err := netsh("interface", "ipv6", "set", "dnsserver", strconv.Itoa(iface.Index), "dhcp"); err != nil {
 			mainLog.Load().Warn().Err(err).Msgf("failed to reset ipv6 DNS: %s", string(output))
 		}
 	}
+	// Restoring ipv4 DHCP.
 	output, err := netsh("interface", "ipv4", "set", "dnsserver", strconv.Itoa(iface.Index), "dhcp")
 	if err != nil {
-		mainLog.Load().Error().Err(err).Msgf("failed to reset ipv4 DNS: %s", string(output))
-		return err
+		return fmt.Errorf("%s: %w", string(output), err)
+	}
+	// If there's static DNS saved, restoring it.
+	if nss := savedStaticNameservers(iface); len(nss) > 0 {
+		v4ns := make([]string, 0, 2)
+		v6ns := make([]string, 0, 2)
+		for _, ns := range nss {
+			if ctrldnet.IsIPv6(ns) {
+				v6ns = append(v6ns, ns)
+			} else {
+				v4ns = append(v4ns, ns)
+			}
+		}
+
+		for _, ns := range [][]string{v4ns, v6ns} {
+			if len(ns) == 0 {
+				continue
+			}
+			primaryDNS := ns[0]
+			if err := setPrimaryDNS(iface, primaryDNS, false); err != nil {
+				return err
+			}
+			if len(ns) > 1 {
+				secondaryDNS := ns[1]
+				_ = addSecondaryDNS(iface, secondaryDNS)
+			}
+		}
 	}
 	return nil
 }
 
-func setPrimaryDNS(iface *net.Interface, dns string) error {
+func setPrimaryDNS(iface *net.Interface, dns string, disablev6 bool) error {
 	ipVer := "ipv4"
 	if ctrldnet.IsIPv6(dns) {
 		ipVer = "ipv6"
@@ -52,7 +131,7 @@ func setPrimaryDNS(iface *net.Interface, dns string) error {
 		mainLog.Load().Error().Err(err).Msgf("failed to set primary DNS: %s", string(output))
 		return err
 	}
-	if ipVer == "ipv4" && ctrldnet.SupportsIPv6ListenLocal() {
+	if disablev6 && ipVer == "ipv4" && ctrldnet.SupportsIPv6ListenLocal() {
 		// Disable IPv6 DNS, so the query will be fallback to IPv4.
 		_, _ = netsh("interface", "ipv6", "set", "dnsserver", idx, "static", "::1", "primary")
 	}
@@ -93,3 +172,54 @@ func currentDNS(iface *net.Interface) []string {
 	}
 	return ns
 }
+
+// currentStaticDNS returns the current static DNS settings of given interface.
+func currentStaticDNS(iface *net.Interface) ([]string, error) {
+	luid, err := winipcfg.LUIDFromIndex(uint32(iface.Index))
+	if err != nil {
+		return nil, err
+	}
+	guid, err := luid.GUID()
+	if err != nil {
+		return nil, err
+	}
+	var ns []string
+	for _, path := range []string{v4InterfaceKeyPathFormat, v6InterfaceKeyPathFormat} {
+		interfaceKeyPath := path + guid.String()
+		found := false
+		for _, key := range []string{"NameServer", "ProfileNameServer"} {
+			if found {
+				continue
+			}
+			cmd := fmt.Sprintf(`Get-ItemPropertyValue -Path "%s" -Name "%s"`, interfaceKeyPath, key)
+			out, err := powershell(cmd)
+			if err == nil && len(out) > 0 {
+				found = true
+				ns = append(ns, strings.Split(string(out), ",")...)
+			}
+		}
+	}
+	return ns, nil
+}
+
+// addDnsServerForwarders adds given nameservers to DNS server forwarders list.
+func addDnsServerForwarders(nameservers []string) error {
+	for _, ns := range nameservers {
+		cmd := fmt.Sprintf("Add-DnsServerForwarder -IPAddress %s", ns)
+		if out, err := powershell(cmd); err != nil {
+			return fmt.Errorf("%w: %s", err, string(out))
+		}
+	}
+	return nil
+}
+
+// removeDnsServerForwarders removes given nameservers from DNS server forwarders list.
+func removeDnsServerForwarders(nameservers []string) error {
+	for _, ns := range nameservers {
+		cmd := fmt.Sprintf("Remove-DnsServerForwarder -IPAddress %s -Force", ns)
+		if out, err := powershell(cmd); err != nil {
+			return fmt.Errorf("%w: %s", err, string(out))
+		}
+	}
+	return nil
+}

cmd/cli/prog.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io/fs"
 	"math/rand"
 	"net"
 	"net/netip"
@@ -13,6 +14,7 @@ import (
 	"runtime"
 	"sort"
 	"strconv"
+	"strings"
 	"sync"
 	"syscall"
 
@@ -348,6 +350,13 @@ func (p *prog) run(reload bool, reloadCh chan struct{}) {
 		p.checkDnsLoopTicker(ctx)
 	}()
 
+	wg.Add(1)
+	// Prometheus exporter goroutine.
+	go func() {
+		defer wg.Done()
+		p.runMetricsServer(ctx, reloadCh)
+	}()
+
 	if !reload {
 		// Stop writing log to unix socket.
 		consoleWriter.Out = os.Stdout
@@ -365,6 +374,11 @@ func (p *prog) run(reload bool, reloadCh chan struct{}) {
 	wg.Wait()
 }
 
+// metricsEnabled reports whether prometheus exporter is enabled/disabled.
+func (p *prog) metricsEnabled() bool {
+	return p.cfg.Service.MetricsQueryStats || p.cfg.Service.MetricsListener != ""
+}
+
 func (p *prog) Stop(s service.Service) error {
 	mainLog.Load().Info().Msg("Service stopped")
 	close(p.stopCh)
@@ -405,8 +419,14 @@ func (p *prog) setDNS() {
 	if iface == "" {
 		return
 	}
+	// allIfaces tracks whether we should set DNS for all physical interfaces.
+	allIfaces := false
 	if iface == "auto" {
 		iface = defaultIfaceName()
+		// If iface is "auto", it means user does not specify "--iface" flag.
+		// In this case, ctrld has to set DNS for all physical interfaces, so
+		// thing will still work when user switch from one to the other.
+		allIfaces = requiredMultiNICsConfig()
 	}
 	lc := cfg.FirstListener()
 	if lc == nil {
@@ -448,14 +468,29 @@ func (p *prog) setDNS() {
 		return
 	}
 	logger.Debug().Msg("setting DNS successfully")
+	if shouldWatchResolvconf() {
+		servers := make([]netip.Addr, len(nameservers))
+		for i := range nameservers {
+			servers[i] = netip.MustParseAddr(nameservers[i])
+		}
+		go watchResolvConf(netIface, servers, setResolvConf)
+	}
+	if allIfaces {
+		withEachPhysicalInterfaces(netIface.Name, "set DNS", func(i *net.Interface) error {
+			return setDNS(i, nameservers)
+		})
+	}
 }
 
 func (p *prog) resetDNS() {
 	if iface == "" {
 		return
 	}
+	allIfaces := false
 	if iface == "auto" {
 		iface = defaultIfaceName()
+		// See corresponding comments in (*prog).setDNS function.
+		allIfaces = requiredMultiNICsConfig()
 	}
 	logger := mainLog.Load().With().Str("iface", iface).Logger()
 	netIface, err := netInterface(iface)
@@ -473,6 +508,9 @@ func (p *prog) resetDNS() {
 		return
 	}
 	logger.Debug().Msg("Restoring DNS successfully")
+	if allIfaces {
+		withEachPhysicalInterfaces(netIface.Name, "reset DNS", resetDNS)
+	}
 }
 
 func randomLocalIP() string {
@@ -556,6 +594,15 @@ func errNetworkError(err error) bool {
 	return false
 }
 
+// errConnectionRefused reports whether err is connection refused.
+func errConnectionRefused(err error) bool {
+	var opErr *net.OpError
+	if !errors.As(err, &opErr) {
+		return false
+	}
+	return errors.Is(opErr.Err, syscall.ECONNREFUSED) || errors.Is(opErr.Err, windowsECONNREFUSED)
+}
+
 func ifaceFirstPrivateIP(iface *net.Interface) string {
 	if iface == nil {
 		return ""
@@ -637,3 +684,87 @@ func canBeLocalUpstream(addr string) bool {
 	}
 	return false
 }
+
+// withEachPhysicalInterfaces runs the function f with each physical interfaces, excluding
+// the interface that matches excludeIfaceName. The context is used to clarify the
+// log message when error happens.
+func withEachPhysicalInterfaces(excludeIfaceName, context string, f func(i *net.Interface) error) {
+	interfaces.ForeachInterface(func(i interfaces.Interface, prefixes []netip.Prefix) {
+		// Skip loopback/virtual interface.
+		if i.IsLoopback() || len(i.HardwareAddr) == 0 {
+			return
+		}
+		// Skip invalid interface.
+		if !validInterface(i.Interface) {
+			return
+		}
+		netIface := i.Interface
+		if err := patchNetIfaceName(netIface); err != nil {
+			mainLog.Load().Debug().Err(err).Msg("failed to patch net interface name")
+			return
+		}
+		// Skip excluded interface.
+		if netIface.Name == excludeIfaceName {
+			return
+		}
+		// TODO: investigate whether we should report this error?
+		if err := f(netIface); err == nil {
+			mainLog.Load().Debug().Msgf("%s for interface %q successfully", context, i.Name)
+		} else if !errors.Is(err, errSaveCurrentStaticDNSNotSupported) {
+			mainLog.Load().Err(err).Msgf("%s for interface %q failed", context, i.Name)
+		}
+	})
+}
+
+// requiredMultiNicConfig reports whether ctrld needs to set/reset DNS for multiple NICs.
+func requiredMultiNICsConfig() bool {
+	switch runtime.GOOS {
+	case "windows", "darwin":
+		return true
+	default:
+		return false
+	}
+}
+
+var errSaveCurrentStaticDNSNotSupported = errors.New("saving current DNS is not supported on this platform")
+
+// saveCurrentStaticDNS saves the current static DNS settings for restoring later.
+// Only works on Windows and Mac.
+func saveCurrentStaticDNS(iface *net.Interface) error {
+	switch runtime.GOOS {
+	case "windows", "darwin":
+	default:
+		return errSaveCurrentStaticDNSNotSupported
+	}
+	file := savedStaticDnsSettingsFilePath(iface)
+	ns, _ := currentStaticDNS(iface)
+	if len(ns) == 0 {
+		_ = os.Remove(file) // removing old static DNS settings
+		return nil
+	}
+	if err := os.Remove(file); err != nil && !errors.Is(err, fs.ErrNotExist) {
+		mainLog.Load().Warn().Err(err).Msg("could not remove old static DNS settings file")
+	}
+	mainLog.Load().Debug().Msgf("DNS settings for %s is static, saving ...", iface.Name)
+	if err := os.WriteFile(file, []byte(strings.Join(ns, ",")), 0600); err != nil {
+		mainLog.Load().Err(err).Msgf("could not save DNS settings for iface: %s", iface.Name)
+		return err
+	}
+	return nil
+}
+
+// savedStaticDnsSettingsFilePath returns the path to saved DNS settings of the given interface.
+func savedStaticDnsSettingsFilePath(iface *net.Interface) string {
+	return absHomeDir(".dns_" + iface.Name)
+}
+
+// savedStaticNameservers returns the static DNS nameservers of the given interface.
+//
+//lint:ignore U1000 use in os_windows.go and os_darwin.go
+func savedStaticNameservers(iface *net.Interface) []string {
+	file := savedStaticDnsSettingsFilePath(iface)
+	if data, _ := os.ReadFile(file); len(data) > 0 {
+		return strings.Split(string(data), ",")
+	}
+	return nil
+}

cmd/cli/prometheus.go

@@ -0,0 +1,57 @@
+package cli
+
+import "github.com/prometheus/client_golang/prometheus"
+
+const (
+	metricsLabelListener       = "listener"
+	metricsLabelClientSourceIP = "client_source_ip"
+	metricsLabelClientMac      = "client_mac"
+	metricsLabelClientHostname = "client_hostname"
+	metricsLabelUpstream       = "upstream"
+	metricsLabelRRType         = "rr_type"
+	metricsLabelRCode          = "rcode"
+)
+
+// statsVersion represent ctrld version.
+var statsVersion = prometheus.NewCounterVec(prometheus.CounterOpts{
+	Name: "ctrld_build_info",
+	Help: "Version of ctrld process.",
+}, []string{"gitref", "goversion", "version"})
+
+// statsTimeStart represents start time of ctrld service.
+var statsTimeStart = prometheus.NewGauge(prometheus.GaugeOpts{
+	Name: "ctrld_time_seconds",
+	Help: "Start time of the ctrld process since unix epoch in seconds.",
+})
+
+var statsQueriesCountLabels = []string{
+	metricsLabelListener,
+	metricsLabelClientSourceIP,
+	metricsLabelClientMac,
+	metricsLabelClientHostname,
+	metricsLabelUpstream,
+	metricsLabelRRType,
+	metricsLabelRCode,
+}
+
+// statsQueriesCount counts total number of queries.
+var statsQueriesCount = prometheus.NewCounterVec(prometheus.CounterOpts{
+	Name: "ctrld_queries_count",
+	Help: "Total number of queries.",
+}, statsQueriesCountLabels)
+
+// statsClientQueriesCount counts total number of queries of a client.
+//
+// The labels "client_source_ip", "client_mac", "client_hostname" are unbounded,
+// thus this stat is highly inefficient if there are many devices.
+var statsClientQueriesCount = prometheus.NewCounterVec(prometheus.CounterOpts{
+	Name: "ctrld_client_queries_count",
+	Help: "Total number queries of a client.",
+}, []string{metricsLabelClientSourceIP, metricsLabelClientMac, metricsLabelClientHostname})
+
+// WithLabelValuesInc increases prometheus counter by 1 if query stats is enabled.
+func (p *prog) WithLabelValuesInc(c *prometheus.CounterVec, lvs ...string) {
+	if p.cfg.Service.MetricsQueryStats {
+		c.WithLabelValues(lvs...).Inc()
+	}
+}

cmd/cli/resolvconf.go

@@ -0,0 +1,65 @@
+package cli
+
+import (
+	"net"
+	"net/netip"
+	"path/filepath"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+const (
+	resolvConfPath            = "/etc/resolv.conf"
+	resolvConfBackupFailedMsg = "open /etc/resolv.pre-ctrld-backup.conf: read-only file system"
+)
+
+// watchResolvConf watches any changes to /etc/resolv.conf file,
+// and reverting to the original config set by ctrld.
+func watchResolvConf(iface *net.Interface, ns []netip.Addr, setDnsFn func(iface *net.Interface, ns []netip.Addr) error) {
+	mainLog.Load().Debug().Msg("start watching /etc/resolv.conf file")
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		mainLog.Load().Warn().Err(err).Msg("could not create watcher for /etc/resolv.conf")
+		return
+	}
+	defer watcher.Close()
+
+	// We watch /etc instead of /etc/resolv.conf directly,
+	// see: https://github.com/fsnotify/fsnotify#watching-a-file-doesnt-work-well
+	watchDir := filepath.Dir(resolvConfPath)
+	if err := watcher.Add(watchDir); err != nil {
+		mainLog.Load().Warn().Err(err).Msg("could not add /etc/resolv.conf to watcher list")
+		return
+	}
+
+	for {
+		select {
+		case event, ok := <-watcher.Events:
+			if !ok {
+				return
+			}
+			if event.Name != resolvConfPath { // skip if not /etc/resolv.conf changes.
+				continue
+			}
+			if event.Has(fsnotify.Write) || event.Has(fsnotify.Create) {
+				mainLog.Load().Debug().Msg("/etc/resolv.conf changes detected, reverting to ctrld setting")
+				if err := watcher.Remove(watchDir); err != nil {
+					mainLog.Load().Error().Err(err).Msg("failed to pause watcher")
+					continue
+				}
+				if err := setDnsFn(iface, ns); err != nil {
+					mainLog.Load().Error().Err(err).Msg("failed to revert /etc/resolv.conf changes")
+				}
+				if err := watcher.Add(watchDir); err != nil {
+					mainLog.Load().Error().Err(err).Msg("failed to continue running watcher")
+					return
+				}
+			}
+		case err, ok := <-watcher.Errors:
+			if !ok {
+				return
+			}
+			mainLog.Load().Err(err).Msg("could not get event for /etc/resolv.conf")
+		}
+	}
+}

cmd/cli/resolvconf_darwin.go

@@ -0,0 +1,20 @@
+package cli
+
+import (
+	"net"
+	"net/netip"
+)
+
+// setResolvConf sets the content of resolv.conf file using the given nameservers list.
+func setResolvConf(iface *net.Interface, ns []netip.Addr) error {
+	servers := make([]string, len(ns))
+	for i := range ns {
+		servers[i] = ns[i].String()
+	}
+	return setDNS(iface, servers)
+}
+
+// shouldWatchResolvconf reports whether ctrld should watch changes to resolv.conf file with given OS configurator.
+func shouldWatchResolvconf() bool {
+	return true
+}

cmd/cli/resolvconf_not_darwin_unix.go

@@ -0,0 +1,40 @@
+//go:build unix && !darwin
+
+package cli
+
+import (
+	"net"
+	"net/netip"
+
+	"tailscale.com/util/dnsname"
+
+	"github.com/Control-D-Inc/ctrld/internal/dns"
+)
+
+// setResolvConf sets the content of resolv.conf file using the given nameservers list.
+func setResolvConf(iface *net.Interface, ns []netip.Addr) error {
+	r, err := dns.NewOSConfigurator(func(format string, args ...any) {}, "lo") // interface name does not matter.
+	if err != nil {
+		return err
+	}
+
+	oc := dns.OSConfig{
+		Nameservers:   ns,
+		SearchDomains: []dnsname.FQDN{},
+	}
+	return r.SetDNS(oc)
+}
+
+// shouldWatchResolvconf reports whether ctrld should watch changes to resolv.conf file with given OS configurator.
+func shouldWatchResolvconf() bool {
+	r, err := dns.NewOSConfigurator(func(format string, args ...any) {}, "lo") // interface name does not matter.
+	if err != nil {
+		return false
+	}
+	switch r.Mode() {
+	case "direct", "resolvconf":
+		return true
+	default:
+		return false
+	}
+}

cmd/cli/resolvconf_windows.go

@@ -0,0 +1,16 @@
+package cli
+
+import (
+	"net"
+	"net/netip"
+)
+
+// setResolvConf sets the content of resolv.conf file using the given nameservers list.
+func setResolvConf(_ *net.Interface, _ []netip.Addr) error {
+	return nil
+}
+
+// shouldWatchResolvconf reports whether ctrld should watch changes to resolv.conf file with given OS configurator.
+func shouldWatchResolvconf() bool {
+	return false
+}

cmd/cli/winres/winres.json

@@ -0,0 +1,20 @@
+{
+  "RT_VERSION": {
+    "#1": {
+      "0000": {
+        "fixed": {
+          "file_version": "0.0.0.1"
+        },
+        "info": {
+          "0409": {
+            "CompanyName": "ControlD Inc",
+            "FileDescription": "Control D DNS daemon",
+            "ProductName": "ctrld",
+            "InternalName": "ctrld",
+            "LegalCopyright": "ControlD Inc 2024"
+          }
+        }
+      }
+    }
+  }
+}

cmd/cli/winres_windows.go

@@ -0,0 +1,4 @@
+//go:generate go-winres make --product-version=git-tag --file-version=git-tag
+package cli
+
+// Placeholder file for windows builds.

cmd/ctrld_library/main.go

@@ -28,14 +28,15 @@ type AppCallback interface {
 // Start configures utility with config.toml from provided directory.
 // This function will block until Stop is called
 // Check port availability prior to calling it.
-func (c *Controller) Start(CdUID string, HomeDir string, logLevel int, logPath string) {
+func (c *Controller) Start(CdUID string, HomeDir string, UpstreamProto string, logLevel int, logPath string) {
 	if c.stopCh == nil {
 		c.stopCh = make(chan struct{})
 		c.Config = cli.AppConfig{
-			CdUID:   CdUID,
-			HomeDir: HomeDir,
-			Verbose: logLevel,
-			LogPath: logPath,
+			CdUID:         CdUID,
+			HomeDir:       HomeDir,
+			UpstreamProto: UpstreamProto,
+			Verbose:       logLevel,
+			LogPath:       logPath,
 		}
 		appCallback := mapCallback(c.AppCallback)
 		cli.RunMobile(&c.Config, &appCallback, c.stopCh)
@@ -60,13 +61,13 @@ func mapCallback(callback AppCallback) cli.AppCallback {
 	}
 }
 
-func (c *Controller) Stop() bool {
-	if c.stopCh != nil {
+func (c *Controller) Stop(Pin int64) int {
+	errorCode := cli.CheckDeactivationPin(Pin)
+	if errorCode == 0 && c.stopCh != nil {
 		close(c.stopCh)
 		c.stopCh = nil
-		return true
 	}
-	return false
+	return errorCode
 }
 
 func (c *Controller) IsRunning() bool {

config.go

@@ -179,23 +179,26 @@ func (c *Config) FirstUpstream() *UpstreamConfig {
 
 // ServiceConfig specifies the general ctrld config.
 type ServiceConfig struct {
-	LogLevel              string `mapstructure:"log_level" toml:"log_level,omitempty"`
-	LogPath               string `mapstructure:"log_path" toml:"log_path,omitempty"`
-	CacheEnable           bool   `mapstructure:"cache_enable" toml:"cache_enable,omitempty"`
-	CacheSize             int    `mapstructure:"cache_size" toml:"cache_size,omitempty"`
-	CacheTTLOverride      int    `mapstructure:"cache_ttl_override" toml:"cache_ttl_override,omitempty"`
-	CacheServeStale       bool   `mapstructure:"cache_serve_stale" toml:"cache_serve_stale,omitempty"`
-	MaxConcurrentRequests *int   `mapstructure:"max_concurrent_requests" toml:"max_concurrent_requests,omitempty" validate:"omitempty,gte=0"`
-	DHCPLeaseFile         string `mapstructure:"dhcp_lease_file_path" toml:"dhcp_lease_file_path" validate:"omitempty,file"`
-	DHCPLeaseFileFormat   string `mapstructure:"dhcp_lease_file_format" toml:"dhcp_lease_file_format" validate:"required_unless=DHCPLeaseFile '',omitempty,oneof=dnsmasq isc-dhcp"`
-	DiscoverMDNS          *bool  `mapstructure:"discover_mdns" toml:"discover_mdns,omitempty"`
-	DiscoverARP           *bool  `mapstructure:"discover_arp" toml:"discover_dhcp,omitempty"`
-	DiscoverDHCP          *bool  `mapstructure:"discover_dhcp" toml:"discover_dhcp,omitempty"`
-	DiscoverPtr           *bool  `mapstructure:"discover_ptr" toml:"discover_ptr,omitempty"`
-	DiscoverHosts         *bool  `mapstructure:"discover_hosts" toml:"discover_hosts,omitempty"`
-	ClientIDPref          string `mapstructure:"client_id_preference" toml:"client_id_preference,omitempty" validate:"omitempty,oneof=host mac"`
-	Daemon                bool   `mapstructure:"-" toml:"-"`
-	AllocateIP            bool   `mapstructure:"-" toml:"-"`
+	LogLevel                string `mapstructure:"log_level" toml:"log_level,omitempty"`
+	LogPath                 string `mapstructure:"log_path" toml:"log_path,omitempty"`
+	CacheEnable             bool   `mapstructure:"cache_enable" toml:"cache_enable,omitempty"`
+	CacheSize               int    `mapstructure:"cache_size" toml:"cache_size,omitempty"`
+	CacheTTLOverride        int    `mapstructure:"cache_ttl_override" toml:"cache_ttl_override,omitempty"`
+	CacheServeStale         bool   `mapstructure:"cache_serve_stale" toml:"cache_serve_stale,omitempty"`
+	MaxConcurrentRequests   *int   `mapstructure:"max_concurrent_requests" toml:"max_concurrent_requests,omitempty" validate:"omitempty,gte=0"`
+	DHCPLeaseFile           string `mapstructure:"dhcp_lease_file_path" toml:"dhcp_lease_file_path" validate:"omitempty,file"`
+	DHCPLeaseFileFormat     string `mapstructure:"dhcp_lease_file_format" toml:"dhcp_lease_file_format" validate:"required_unless=DHCPLeaseFile '',omitempty,oneof=dnsmasq isc-dhcp"`
+	DiscoverMDNS            *bool  `mapstructure:"discover_mdns" toml:"discover_mdns,omitempty"`
+	DiscoverARP             *bool  `mapstructure:"discover_arp" toml:"discover_arp,omitempty"`
+	DiscoverDHCP            *bool  `mapstructure:"discover_dhcp" toml:"discover_dhcp,omitempty"`
+	DiscoverPtr             *bool  `mapstructure:"discover_ptr" toml:"discover_ptr,omitempty"`
+	DiscoverHosts           *bool  `mapstructure:"discover_hosts" toml:"discover_hosts,omitempty"`
+	DiscoverRefreshInterval int    `mapstructure:"discover_refresh_interval" toml:"discover_refresh_interval,omitempty"`
+	ClientIDPref            string `mapstructure:"client_id_preference" toml:"client_id_preference,omitempty" validate:"omitempty,oneof=host mac"`
+	MetricsQueryStats       bool   `mapstructure:"metrics_query_stats" toml:"metrics_query_stats,omitempty"`
+	MetricsListener         string `mapstructure:"metrics_listener" toml:"metrics_listener,omitempty"`
+	Daemon                  bool   `mapstructure:"-" toml:"-"`
+	AllocateIP              bool   `mapstructure:"-" toml:"-"`
 }
 
 // NetworkConfig specifies configuration for networks where ctrld will handle requests.

config_quic.go

@@ -1,5 +1,3 @@
-//go:build !qf
-
 package ctrld
 
 import (

config_quic_free.go

@@ -1,9 +0,0 @@
-//go:build qf
-
-package ctrld
-
-import "net/http"
-
-func (uc *UpstreamConfig) setupDOH3Transport() {}
-
-func (uc *UpstreamConfig) doh3Transport(dnsType uint16) http.RoundTripper { return nil }

config_test.go

@@ -121,6 +121,29 @@ func TestConfigValidation(t *testing.T) {
 	}
 }
 
+func TestConfigDiscoverOverride(t *testing.T) {
+	v := viper.NewWithOptions(viper.KeyDelimiter("::"))
+	ctrld.InitConfig(v, "test_config_discover_override")
+	v.SetConfigType("toml")
+	configStr := `
+[service]
+discover_arp = false
+discover_dhcp = false
+discover_hosts = false
+discover_mdns = false
+discover_ptr = false
+`
+	require.NoError(t, v.ReadConfig(strings.NewReader(configStr)))
+	cfg := ctrld.Config{}
+	require.NoError(t, v.Unmarshal(&cfg))
+
+	require.False(t, *cfg.Service.DiscoverARP)
+	require.False(t, *cfg.Service.DiscoverDHCP)
+	require.False(t, *cfg.Service.DiscoverHosts)
+	require.False(t, *cfg.Service.DiscoverMDNS)
+	require.False(t, *cfg.Service.DiscoverPtr)
+}
+
 func defaultConfig(t *testing.T) *ctrld.Config {
 	v := viper.New()
 	ctrld.InitConfig(v, "test_load_default_config")

docs/config.md

@@ -200,6 +200,14 @@ Perform LAN client discovery using hosts file.
 - Required: no
 - Default: true
 
+### discover_refresh_interval
+Time in seconds between each discovery refresh loop to update new client information data. 
+The default value is 120 seconds, lower this value to make the discovery process run more aggressively.
+
+- Type: integer
+- Required: no
+- Default: 120
+
 ### dhcp_lease_file_path
 Relative or absolute path to a custom DHCP leases file location. 
 
@@ -216,16 +224,27 @@ DHCP leases file format.
 - Default: ""
 
 ### client_id_preference
-Decide how the client ID is generated
+Decide how the client ID is generated. By default client ID will use both MAC address and Hostname i.e. `hash(mac + host)`. To override this behavior, select one of the 2 allowed values to scope client ID to just MAC address OR Hostname.  
 
-If `host` -> client id will only use the hostname i.e.`hash(hostname)`.
-If `mac` -> client id will only use the MAC address `hash(mac)`.
-Else -> client ID will use both Mac and Hostname i.e. `hash(mac + host)
 - Type: string
 - Required: no
 - Valid values: `mac`, `host`
 - Default: ""
 
+### metrics_query_stats
+If set to `true`, collect and export the query counters, and show them in `clients list` command.
+
+- Type: boolean
+- Required: no
+- Default: false
+
+### metrics_listener
+Specifying the `ip` and `port` of the Prometheus metrics server. The Prometheus metrics will be available on: `http://ip:port/metrics`. You can also append `/metrics/json` to get the same data in json format. 
+
+- Type: string
+- Required: no
+- Default: ""
+
 ## Upstream
 The `[upstream]` section specifies the DNS upstream servers that `ctrld` will forward DNS requests to.
 
@@ -331,7 +350,7 @@ If `ip_stack` is empty, or undefined:
  - Default value is `split` for Control D resolvers.
 
 ### send_client_info
-Specifying whether to include client info when sending query to upstream.
+Specifying whether to include client info when sending query to upstream. **This will only work with `doh` or `doh3` type upstreams.** 
 
 - Type: boolean
 - Required: no

go.mod

@@ -1,6 +1,6 @@
 module github.com/Control-D-Inc/ctrld
 
-go 1.20
+go 1.21
 
 require (
 	github.com/coreos/go-systemd/v22 v22.5.0
@@ -15,10 +15,14 @@ require (
 	github.com/jaytaylor/go-hostsfile v0.0.0-20220426042432-61485ac1fa6c
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86
 	github.com/kardianos/service v1.2.1
+	github.com/mdlayher/ndp v1.0.1
 	github.com/miekg/dns v1.1.55
 	github.com/olekukonko/tablewriter v0.0.5
 	github.com/pelletier/go-toml/v2 v2.0.8
-	github.com/quic-go/quic-go v0.38.0
+	github.com/prometheus/client_golang v1.15.1
+	github.com/prometheus/client_model v0.4.0
+	github.com/prometheus/prom2json v1.3.3
+	github.com/quic-go/quic-go v0.41.0
 	github.com/rs/zerolog v1.28.0
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
@@ -34,11 +38,13 @@ require (
 
 require (
 	github.com/alexbrainman/sspi v0.0.0-20210105120005-909beea2cc74 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-playground/locales v0.14.0 // indirect
 	github.com/go-playground/universal-translator v0.18.0 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 // indirect
-	github.com/golang/mock v1.6.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
@@ -51,6 +57,7 @@ require (
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.18 // indirect
 	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
 	github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065 // indirect
@@ -59,8 +66,9 @@ require (
 	github.com/onsi/ginkgo/v2 v2.9.5 // indirect
 	github.com/pierrec/lz4/v4 v4.1.17 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.9.0 // indirect
 	github.com/quic-go/qpack v0.4.0 // indirect
-	github.com/quic-go/qtls-go1-20 v0.3.2 // indirect
 	github.com/rivo/uniseg v0.4.4 // indirect
 	github.com/rogpeppe/go-internal v1.10.0 // indirect
 	github.com/spf13/afero v1.9.5 // indirect
@@ -69,12 +77,14 @@ require (
 	github.com/subosito/gotenv v1.4.2 // indirect
 	github.com/u-root/uio v0.0.0-20230305220412-3e8cd9d6bf63 // indirect
 	github.com/vishvananda/netns v0.0.4 // indirect
+	go.uber.org/mock v0.3.0 // indirect
 	go4.org/mem v0.0.0-20220726221520-4f986261bf13 // indirect
 	golang.org/x/crypto v0.14.0 // indirect
 	golang.org/x/exp v0.0.0-20230425010034-47ecfdc1ba53 // indirect
-	golang.org/x/mod v0.10.0 // indirect
+	golang.org/x/mod v0.11.0 // indirect
 	golang.org/x/text v0.13.0 // indirect
 	golang.org/x/tools v0.9.1 // indirect
+	google.golang.org/protobuf v1.30.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -42,11 +42,16 @@ github.com/Windscribe/zerolog v0.0.0-20230503170159-e6aa153233be h1:qBKVRi7Mom5h
 github.com/Windscribe/zerolog v0.0.0-20230503170159-e6aa153233be/go.mod h1:/tk+P47gFdPXq4QYjvCmT5/Gsug2nagsFWBWhAiSi1w=
 github.com/alexbrainman/sspi v0.0.0-20210105120005-909beea2cc74 h1:Kk6a4nehpJ3UuJRqlA3JxYxBZEqCeOmATOvrbT4p9RA=
 github.com/alexbrainman/sspi v0.0.0-20210105120005-909beea2cc74/go.mod h1:cEWa1LVoE5KvSD9ONXsZrj0z6KqySlCCNKHlLzbqAt4=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
+github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/cilium/ebpf v0.10.0 h1:nk5HPMeoBXtOzbkZBWym+ZWq1GIiHUsBFXxwewXAHLQ=
+github.com/cilium/ebpf v0.10.0/go.mod h1:DPiVdY/kT534dgc9ERmvP8mWA+9gvwgKfRvk4nNWnoE=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
@@ -74,6 +79,7 @@ github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/go-logr/logr v1.2.4 h1:g01GSCwiDw2xSZfjJ2/T9M+S6pFdcNtFYsp+Y43HYDQ=
+github.com/go-logr/logr v1.2.4/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-playground/assert/v2 v2.0.1 h1:MsBgLAaY856+nPRTKrp3/OZK38U/wa0CcBYNjji3q3A=
 github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.14.0 h1:u50s323jtVGugKlcYeyzC0etD1HifMjqmJqb8WugfUU=
@@ -98,8 +104,6 @@ github.com/golang/mock v1.4.0/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt
 github.com/golang/mock v1.4.1/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/mock v1.4.3/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/mock v1.4.4/go.mod h1:l3mdAwkq5BuhzHwde/uurv3sEJeZMXNpwsxVWU71h+4=
-github.com/golang/mock v1.6.0 h1:ErTB+efbowRARo13NNdxyJji2egdxLGQhRaY+DUumQc=
-github.com/golang/mock v1.6.0/go.mod h1:p6yTPP+5HYm5mzsMV8JkE6ZKdX+/wYM6Hr+LicevLPs=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -114,7 +118,9 @@ github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvq
 github.com/golang/protobuf v1.4.1/go.mod h1:U8fpvMrcmy5pZrNK1lt4xCsGvpyWQ/VVv6QDs8UjoX8=
 github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
 github.com/golang/protobuf v1.4.3/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
@@ -126,6 +132,7 @@ github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
@@ -155,6 +162,7 @@ github.com/hashicorp/golang-lru/v2 v2.0.1/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyf
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714 h1:/jC7qQFrv8CrSJVmaolDVOxTfS9kc36uB6H40kdbQq8=
+github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714/go.mod h1:2Goc3h8EklBH5mspfHFxBnEoURQCGzQQH1ga9Myjvis=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/illarion/gonotify v1.0.1 h1:F1d+0Fgbq/sDWjj/r66ekjDG+IDeecQKUFH4wNwsoio=
@@ -199,8 +207,12 @@ github.com/mattn/go-isatty v0.0.18/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/mattn/go-runewidth v0.0.14 h1:+xnbZSEeDbOIg5/mE6JF0w6n9duR1l3/WmbinWVwUuU=
 github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7 h1:lez6TS6aAau+8wXUP3G9I3TGlmPFEq2CTxBaRqY6AGE=
 github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7/go.mod h1:U6ZQobyTjI/tJyq2HG+i/dfSoFUt8/aZCM+GKtmFk/Y=
+github.com/mdlayher/ndp v1.0.1 h1:+yAD79/BWyFlvAoeG5ncPS0ItlHP/eVbH7bQ6/+LVA4=
+github.com/mdlayher/ndp v1.0.1/go.mod h1:rf3wKaWhAYJEXFKpgF8kQ2AxypxVbfNcZbqoAo6fVzk=
 github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g=
 github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw=
 github.com/mdlayher/raw v0.0.0-20190606142536-fef19f00fc18/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
@@ -217,6 +229,7 @@ github.com/olekukonko/tablewriter v0.0.5/go.mod h1:hPp6KlRPjbx+hW8ykQs1w3UBbZlj6
 github.com/onsi/ginkgo/v2 v2.9.5 h1:+6Hr4uxzP4XIUyAkg61dWBw8lb/gc4/X5luuxN/EC+Q=
 github.com/onsi/ginkgo/v2 v2.9.5/go.mod h1:tvAoo1QUJwNEU2ITftXTpR7R1RbCzoZUOs3RonqW57k=
 github.com/onsi/gomega v1.27.6 h1:ENqfyGeS5AX/rlXDd/ETokDz93u0YufY1Pgxuy/PvWE=
+github.com/onsi/gomega v1.27.6/go.mod h1:PIQNjfQwkP3aQAH7lf7j87O/5FiNr+ZR8+ipb+qQlhg=
 github.com/pelletier/go-toml/v2 v2.0.8 h1:0ctb6s9mE31h0/lhu+J6OPmVeDxJn+kYnJc2jZR9tGQ=
 github.com/pelletier/go-toml/v2 v2.0.8/go.mod h1:vuYfssBdrU2XDZ9bYydBu6t+6a6PYNcZljzZR9VXg+4=
 github.com/pierrec/lz4/v4 v4.1.14/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
@@ -227,13 +240,21 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pkg/sftp v1.13.1/go.mod h1:3HaPG6Dq1ILlpPZRO0HVMrsydcdLt6HRDccSgb87qRg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.15.1 h1:8tXpTmJbyH5lydzFPoxSIJ0J46jdh3tylbvM1xCv0LI=
+github.com/prometheus/client_golang v1.15.1/go.mod h1:e9yaBhRPU2pPNsZwE+JdQl0KEt1N9XgF6zxWmaC0xOk=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.4.0 h1:5lQXD3cAg1OXBf4Wq03gTrXHeaV0TQvGfUooCfx1yqY=
+github.com/prometheus/client_model v0.4.0/go.mod h1:oMQmHW1/JoDwqLtg57MGgP/Fb1CJEYF2imWWhWtMkYU=
+github.com/prometheus/common v0.44.0 h1:+5BrQJwiBB9xsMygAB3TNvpQKOwlkc25LbISbrdOOfY=
+github.com/prometheus/common v0.44.0/go.mod h1:ofAIvZbQ1e/nugmZGz4/qCb9Ap1VoSTIO7x0VV9VvuY=
+github.com/prometheus/procfs v0.9.0 h1:wzCHvIvM5SxWqYvwgVL7yJY8Lz3PKn49KQtpgMYJfhI=
+github.com/prometheus/procfs v0.9.0/go.mod h1:+pB4zwohETzFnmlpe6yd2lSc+0/46IYZRB/chUwxUZY=
+github.com/prometheus/prom2json v1.3.3 h1:IYfSMiZ7sSOfliBoo89PcufjWO4eAR0gznGcETyaUgo=
+github.com/prometheus/prom2json v1.3.3/go.mod h1:Pv4yIPktEkK7btWsrUTWDDDrnpUrAELaOCj+oFwlgmc=
 github.com/quic-go/qpack v0.4.0 h1:Cr9BXA1sQS2SmDUWjSofMPNKmvF6IiIfDRmgU0w1ZCo=
 github.com/quic-go/qpack v0.4.0/go.mod h1:UZVnYIfi5GRk+zI9UMaCPsmZ2xKJP7XBUvVyT1Knj9A=
-github.com/quic-go/qtls-go1-20 v0.3.2 h1:rRgN3WfnKbyik4dBV8A6girlJVxGand/d+jVKbQq5GI=
-github.com/quic-go/qtls-go1-20 v0.3.2/go.mod h1:X9Nh97ZL80Z+bX/gUXMbipO6OxdiDi58b/fMC9mAL+k=
-github.com/quic-go/quic-go v0.38.0 h1:T45lASr5q/TrVwt+jrVccmqHhPL2XuSyoCLVCpfOSLc=
-github.com/quic-go/quic-go v0.38.0/go.mod h1:MPCuRq7KBK2hNcfKj/1iD1BGuN3eAYMeNxp3T42LRUg=
+github.com/quic-go/quic-go v0.41.0 h1:aD8MmHfgqTURWNJy48IYFg2OnxwHT3JL7ahGs73lb4k=
+github.com/quic-go/quic-go v0.41.0/go.mod h1:qCkNjqczPEvgsOnxZ0eCD14lv+B2LHlFAB++CNOh9hA=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
 github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
@@ -283,13 +304,14 @@ github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
+go.uber.org/mock v0.3.0 h1:3mUxI1No2/60yUYax92Pt8eNOEecx2D3lcXZh2NEZJo=
+go.uber.org/mock v0.3.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
 go4.org/mem v0.0.0-20220726221520-4f986261bf13 h1:CbZeCBZ0aZj8EfVgnqQcYZgf0lpZ3H9rmp5nkDTAst8=
 go4.org/mem v0.0.0-20220726221520-4f986261bf13/go.mod h1:reUoABIJ9ikfM5sgtSF3Wushcza7+WeD01VB9Lirh3g=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -337,9 +359,8 @@ golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
-golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.11.0 h1:bUO06HqtnRcc/7l71XBe4WcqTZ+3AH1J59zWDDwLKgU=
+golang.org/x/mod v0.11.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -372,7 +393,6 @@ golang.org/x/net v0.0.0-20201031054903-ff519b6c9102/go.mod h1:sp8m0HH+o8qH0wwXwY
 golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20201224014010-6772e930b67b/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
 golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
@@ -395,7 +415,6 @@ golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
 golang.org/x/sync v0.2.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -435,10 +454,8 @@ golang.org/x/sys v0.0.0-20201201145000-ef89a241ccb3/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210104204734-6f8348627aad/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210225134936-a50acf3fe073/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210806184541-e5e7981a1069/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -511,7 +528,6 @@ golang.org/x/tools v0.0.0-20201208233053-a543418bbed2/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.0.0-20210105154028-b0ab187a4818/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
-golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.9.1 h1:8WMNJAz3zrtPmnYC7ISf5dEn3MT0gY7jBJfw27yrrLo=
 golang.org/x/tools v0.9.1/go.mod h1:owI94Op576fPu3cIGQeHs3joujW/2Oc6MtlxbF5dfNc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -608,7 +624,10 @@ google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2
 google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
 google.golang.org/protobuf v1.24.0/go.mod h1:r/3tXBNzIEhYS9I1OUVjXDlt8tc493IdKGjtUeSXeh4=
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 google.golang.org/protobuf v1.30.0 h1:kPPoIgf3TsEvrm0PFe15JQ+570QVxYzEvvHqChK+cng=
+google.golang.org/protobuf v1.30.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=

internal/clientinfo/client_info.go

@@ -58,10 +58,12 @@ type ipLister interface {
 }
 
 type Client struct {
-	IP       netip.Addr
-	Mac      string
-	Hostname string
-	Source   map[string]struct{}
+	IP                netip.Addr
+	Mac               string
+	Hostname          string
+	Source            map[string]struct{}
+	QueryCount        int64
+	IncludeQueryCount bool
 }
 
 type Table struct {
@@ -70,10 +72,13 @@ type Table struct {
 	hostnameResolvers []HostnameResolver
 	refreshers        []refresher
 	initOnce          sync.Once
+	refreshInterval   int
 
 	dhcp           *dhcp
 	merlin         *merlinDiscover
+	ubios          *ubiosDiscover
 	arp            *arpDiscover
+	ndp            *ndpDiscover
 	ptr            *ptrDiscover
 	mdns           *mdns
 	hf             *hostsFile
@@ -86,12 +91,17 @@ type Table struct {
 }
 
 func NewTable(cfg *ctrld.Config, selfIP, cdUID string, ns []string) *Table {
+	refreshInterval := cfg.Service.DiscoverRefreshInterval
+	if refreshInterval <= 0 {
+		refreshInterval = 2 * 60 // 2 minutes
+	}
 	return &Table{
-		svcCfg:         cfg.Service,
-		quitCh:         make(chan struct{}),
-		selfIP:         selfIP,
-		cdUID:          cdUID,
-		ptrNameservers: ns,
+		svcCfg:          cfg.Service,
+		quitCh:          make(chan struct{}),
+		selfIP:          selfIP,
+		cdUID:           cdUID,
+		ptrNameservers:  ns,
+		refreshInterval: refreshInterval,
 	}
 }
 
@@ -102,8 +112,9 @@ func (t *Table) AddLeaseFile(name string, format ctrld.LeaseFileFormat) {
 	clientInfoFiles[name] = format
 }
 
+// RefreshLoop runs all the refresher to update new client info data.
 func (t *Table) RefreshLoop(ctx context.Context) {
-	timer := time.NewTicker(time.Minute * 5)
+	timer := time.NewTicker(time.Second * time.Duration(t.refreshInterval))
 	defer timer.Stop()
 	for {
 		select {
@@ -137,14 +148,26 @@ func (t *Table) init() {
 	// Otherwise, process all possible sources in order, that means
 	// the first result of IP/MAC/Hostname lookup will be used.
 	//
-	// Merlin custom clients.
+	// Routers custom clients:
+	//  - Merlin
+	//  - Ubios
 	if t.discoverDHCP() || t.discoverARP() {
 		t.merlin = &merlinDiscover{}
-		if err := t.merlin.refresh(); err != nil {
-			ctrld.ProxyLogger.Load().Error().Err(err).Msg("could not init Merlin discover")
-		} else {
-			t.hostnameResolvers = append(t.hostnameResolvers, t.merlin)
-			t.refreshers = append(t.refreshers, t.merlin)
+		t.ubios = &ubiosDiscover{}
+		discovers := map[string]interface {
+			refresher
+			HostnameResolver
+		}{
+			"Merlin": t.merlin,
+			"Ubios":  t.ubios,
+		}
+		for platform, discover := range discovers {
+			if err := discover.refresh(); err != nil {
+				ctrld.ProxyLogger.Load().Error().Err(err).Msgf("could not init %s discover", platform)
+			} else {
+				t.hostnameResolvers = append(t.hostnameResolvers, discover)
+				t.refreshers = append(t.refreshers, discover)
+			}
 		}
 	}
 	// Hosts file mapping.
@@ -172,17 +195,35 @@ func (t *Table) init() {
 		}
 		go t.dhcp.watchChanges()
 	}
-	// ARP table.
+	// ARP/NDP table.
 	if t.discoverARP() {
 		t.arp = &arpDiscover{}
+		t.ndp = &ndpDiscover{}
 		ctrld.ProxyLogger.Load().Debug().Msg("start arp discovery")
-		if err := t.arp.refresh(); err != nil {
-			ctrld.ProxyLogger.Load().Error().Err(err).Msg("could not init ARP discover")
-		} else {
-			t.ipResolvers = append(t.ipResolvers, t.arp)
-			t.macResolvers = append(t.macResolvers, t.arp)
-			t.refreshers = append(t.refreshers, t.arp)
+		discovers := map[string]interface {
+			refresher
+			IpResolver
+			MacResolver
+		}{
+			"ARP": t.arp,
+			"NDP": t.ndp,
 		}
+
+		for protocol, discover := range discovers {
+			if err := discover.refresh(); err != nil {
+				ctrld.ProxyLogger.Load().Error().Err(err).Msgf("could not init %s discover", protocol)
+			} else {
+				t.ipResolvers = append(t.ipResolvers, discover)
+				t.macResolvers = append(t.macResolvers, discover)
+				t.refreshers = append(t.refreshers, discover)
+			}
+		}
+		ctx, cancel := context.WithCancel(context.Background())
+		go func() {
+			<-t.quitCh
+			cancel()
+		}()
+		go t.ndp.listen(ctx)
 	}
 	// PTR lookup.
 	if t.discoverPTR() {
@@ -328,7 +369,7 @@ func (t *Table) ListClients() []*Client {
 		_ = r.refresh()
 	}
 	ipMap := make(map[string]*Client)
-	il := []ipLister{t.dhcp, t.arp, t.ptr, t.mdns, t.vni}
+	il := []ipLister{t.dhcp, t.arp, t.ndp, t.ptr, t.mdns, t.vni}
 	for _, ir := range il {
 		for _, ip := range ir.List() {
 			c, ok := ipMap[ip]
@@ -343,6 +384,7 @@ func (t *Table) ListClients() []*Client {
 			}
 		}
 	}
+	clientsByMAC := make(map[string]*Client)
 	for ip := range ipMap {
 		c := ipMap[ip]
 		for _, e := range t.lookupMacAll(ip) {
@@ -356,6 +398,7 @@ func (t *Table) ListClients() []*Client {
 		for _, e := range t.lookupHostnameAll(ip, c.Mac) {
 			if c.Hostname == "" && e.name != "" {
 				c.Hostname = e.name
+				clientsByMAC[c.Mac] = c
 			}
 			if e.name != "" {
 				c.Source[e.src] = struct{}{}
@@ -364,6 +407,11 @@ func (t *Table) ListClients() []*Client {
 	}
 	clients := make([]*Client, 0, len(ipMap))
 	for _, c := range ipMap {
+		// If we found a client with empty hostname, use hostname from
+		// an existed client which has the same MAC address.
+		if cFromMac := clientsByMAC[c.Mac]; cFromMac != nil && c.Hostname == "" {
+			c.Hostname = cFromMac.Hostname
+		}
 		clients = append(clients, c)
 	}
 	return clients

internal/clientinfo/client_info_test.go

@@ -44,3 +44,31 @@ func TestTable_LookupRFC1918IPv4(t *testing.T) {
 		t.Fatalf("unexpected result, want: %s, got: %s", rfc1918IPv4, got)
 	}
 }
+
+func TestTable_ListClients(t *testing.T) {
+	mac := "74:56:3c:44:eb:5e"
+	ipv6_1 := "2405:4803:a04b:4190:fbe9:cd14:d522:bbae"
+	ipv6_2 := "2405:4803:a04b:4190:fbe9:cd14:d522:bbab"
+	table := &Table{}
+
+	// NDP init.
+	table.ndp = &ndpDiscover{}
+	table.ndp.mac.Store(ipv6_1, mac)
+	table.ndp.mac.Store(ipv6_2, mac)
+	table.ndp.ip.Store(mac, ipv6_1)
+	table.ndp.ip.Store(mac, ipv6_2)
+	table.ipResolvers = append(table.ipResolvers, table.ndp)
+	table.macResolvers = append(table.macResolvers, table.ndp)
+
+	hostname := "foo"
+	// mdns init.
+	table.mdns = &mdns{}
+	table.mdns.name.Store(ipv6_2, hostname)
+	table.hostnameResolvers = append(table.hostnameResolvers, table.mdns)
+
+	for _, c := range table.ListClients() {
+		if c.Hostname != hostname {
+			t.Fatalf("missing hostname for client: %v", c)
+		}
+	}
+}

internal/clientinfo/dhcp.go

@@ -3,6 +3,7 @@ package clientinfo
 import (
 	"bufio"
 	"bytes"
+	"encoding/csv"
 	"fmt"
 	"io"
 	"net"
@@ -187,6 +188,8 @@ func (d *dhcp) readLeaseFile(name string, format ctrld.LeaseFileFormat) error {
 		return d.dnsmasqReadClientInfoFile(name)
 	case ctrld.IscDhcpd:
 		return d.iscDHCPReadClientInfoFile(name)
+	case ctrld.KeaDHCP4:
+		return d.keaDhcp4ReadClientInfoFile(name)
 	}
 	return fmt.Errorf("unsupported format: %s, file: %s", format, name)
 }
@@ -202,7 +205,8 @@ func (d *dhcp) dnsmasqReadClientInfoFile(name string) error {
 
 }
 
-// dnsmasqReadClientInfoReader likes ctrld.Dnsmasq, but reading from an io.Reader instead of file.
+// dnsmasqReadClientInfoReader performs the same task as dnsmasqReadClientInfoFile,
+// but by reading from an io.Reader instead of file.
 func (d *dhcp) dnsmasqReadClientInfoReader(reader io.Reader) error {
 	return lineread.Reader(reader, func(line []byte) error {
 		fields := bytes.Fields(line)
@@ -244,7 +248,8 @@ func (d *dhcp) iscDHCPReadClientInfoFile(name string) error {
 	return d.iscDHCPReadClientInfoReader(f)
 }
 
-// iscDHCPReadClientInfoReader likes ctrld.IscDhcpd, but reading from an io.Reader instead of file.
+// iscDHCPReadClientInfoReader performs the same task as iscDHCPReadClientInfoFile,
+// but by reading from an io.Reader instead of file.
 func (d *dhcp) iscDHCPReadClientInfoReader(reader io.Reader) error {
 	s := bufio.NewScanner(reader)
 	var ip, mac, hostname string
@@ -287,6 +292,58 @@ func (d *dhcp) iscDHCPReadClientInfoReader(reader io.Reader) error {
 	return nil
 }
 
+// keaDhcp4ReadClientInfoFile populates dhcp table with client info reading from kea dhcp4 lease file.
+func (d *dhcp) keaDhcp4ReadClientInfoFile(name string) error {
+	f, err := os.Open(name)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return d.keaDhcp4ReadClientInfoReader(bufio.NewReader(f))
+
+}
+
+// keaDhcp4ReadClientInfoReader performs the same task as keaDhcp4ReadClientInfoFile,
+// but by reading from an io.Reader instead of file.
+func (d *dhcp) keaDhcp4ReadClientInfoReader(r io.Reader) error {
+	cr := csv.NewReader(r)
+	for {
+		record, err := cr.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if len(record) < 9 {
+			continue // hostname is at 9th field, so skipping record with not enough fields.
+		}
+		if record[0] == "address" {
+			continue // skip header.
+		}
+		mac := record[1]
+		if _, err := net.ParseMAC(mac); err != nil { // skip invalid MAC
+			continue
+		}
+		ip := normalizeIP(record[0])
+		if net.ParseIP(ip) == nil {
+			ctrld.ProxyLogger.Load().Warn().Msgf("invalid ip address entry: %q", ip)
+			ip = ""
+		}
+
+		d.mac.Store(ip, mac)
+		d.ip.Store(mac, ip)
+		hostname := record[8]
+		if hostname == "*" {
+			continue
+		}
+		name := normalizeHostname(hostname)
+		d.mac2name.Store(mac, name)
+		d.ip2name.Store(ip, name)
+	}
+	return nil
+}
+
 // addSelf populates current host info to dhcp, so queries from
 // the host itself can be attached with proper client info.
 func (d *dhcp) addSelf() {

internal/clientinfo/dhcp_lease_files.go

@@ -15,4 +15,5 @@ var clientInfoFiles = map[string]ctrld.LeaseFileFormat{
 	"/run/dhcpd.leases":                        ctrld.IscDhcpd, // EdgeOS
 	"/var/dhcpd/var/db/dhcpd.leases":           ctrld.IscDhcpd, // Pfsense
 	"/home/pi/.router/run/dhcp/dnsmasq.leases": ctrld.Dnsmasq,  // Firewalla
+	"/var/lib/kea/dhcp4.leases":                ctrld.KeaDHCP4, // Pfsense
 }

internal/clientinfo/dhcp_test.go

@@ -67,6 +67,41 @@ lease 192.168.1.2 {
 			"00:00:00:00:00:04",
 			"example",
 		},
+		{
+			"kea-dhcp4 good",
+			`address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id
+192.168.0.123,00:00:00:00:00:05,00:00:00:00:00:05,7200,1703290639,1,0,0,foo,0,,0
+`,
+			d.keaDhcp4ReadClientInfoReader,
+			"00:00:00:00:00:05",
+			"foo",
+		},
+		{
+			"kea-dhcp4 no-header",
+			`192.168.0.123,00:00:00:00:00:05,00:00:00:00:00:05,7200,1703290639,1,0,0,foo,0,,0`,
+			d.keaDhcp4ReadClientInfoReader,
+			"00:00:00:00:00:05",
+			"foo",
+		},
+		{
+			"kea-dhcp4 hostname *",
+			`address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id
+192.168.0.123,00:00:00:00:00:05,00:00:00:00:00:05,7200,1703290639,1,0,0,*,0,,0
+`,
+			d.keaDhcp4ReadClientInfoReader,
+			"00:00:00:00:00:05",
+			"*",
+		},
+		{
+			"kea-dhcp4 bad",
+			`address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id
+192.168.0.123,00:00:00:00:00:05,00:00:00:00:00:05,7200,1703290639,1,0,0,foo,0,,0
+192.168.0.124,invalid_MAC,00:00:00:00:00:05,7200,1703290639,1,0,0,foo,0,,0
+`,
+			d.keaDhcp4ReadClientInfoReader,
+			"00:00:00:00:00:05",
+			"foo",
+		},
 	}
 
 	for _, tc := range tests {
@@ -76,6 +111,12 @@ lease 192.168.1.2 {
 				t.Errorf("readClientInfoReader() error = %v", err)
 			}
 			val, existed := d.mac2name.Load(tc.mac)
+			if tc.hostname == "*" {
+				if existed {
+					t.Errorf("* hostname must be skipped")
+				}
+				return
+			}
 			if !existed {
 				t.Error("client info missing")
 			}

internal/clientinfo/hostsfile.go

@@ -1,8 +1,12 @@
 package clientinfo
 
 import (
+	"bufio"
+	"bytes"
+	"io"
 	"net/netip"
 	"os"
+	"strings"
 	"sync"
 
 	"github.com/fsnotify/fsnotify"
@@ -12,9 +16,10 @@ import (
 )
 
 const (
-	ipv4LocalhostName = "localhost"
-	ipv6LocalhostName = "ip6-localhost"
-	ipv6LoopbackName  = "ip6-loopback"
+	ipv4LocalhostName   = "localhost"
+	ipv6LocalhostName   = "ip6-localhost"
+	ipv6LoopbackName    = "ip6-loopback"
+	hostEntriesConfPath = "/var/unbound/host_entries.conf"
 )
 
 // hostsFile provides client discovery functionality using system hosts file.
@@ -34,14 +39,9 @@ func (hf *hostsFile) init() error {
 	if err := hf.watcher.Add(hostsfile.HostsPath); err != nil {
 		return err
 	}
-	m, err := hostsfile.ParseHosts(hostsfile.ReadHostsFile())
-	if err != nil {
-		return err
-	}
-	hf.mu.Lock()
-	hf.m = m
-	hf.mu.Unlock()
-	return nil
+	// Conservatively adding hostEntriesConfPath, since it is not available everywhere.
+	_ = hf.watcher.Add(hostEntriesConfPath)
+	return hf.refresh()
 }
 
 // refresh reloads hosts file entries.
@@ -52,6 +52,14 @@ func (hf *hostsFile) refresh() error {
 	}
 	hf.mu.Lock()
 	hf.m = m
+	// override hosts file with host_entries.conf content if present.
+	hem, err := parseHostEntriesConf(hostEntriesConfPath)
+	if err != nil && !os.IsNotExist(err) {
+		ctrld.ProxyLogger.Load().Debug().Err(err).Msg("could not read host_entries.conf file")
+	}
+	for k, v := range hem {
+		hf.m[k] = v
+	}
 	hf.mu.Unlock()
 	return nil
 }
@@ -137,3 +145,46 @@ func isLocalhostName(hostname string) bool {
 		return false
 	}
 }
+
+// parseHostEntriesConf parses host_entries.conf file and returns parsed result.
+func parseHostEntriesConf(path string) (map[string][]string, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return parseHostEntriesConfFromReader(bytes.NewReader(b)), nil
+}
+
+// parseHostEntriesConfFromReader is like parseHostEntriesConf, but read from an io.Reader instead of file.
+func parseHostEntriesConfFromReader(r io.Reader) map[string][]string {
+	hostsMap := map[string][]string{}
+	scanner := bufio.NewScanner(r)
+
+	localZone := ""
+	for scanner.Scan() {
+		line := scanner.Text()
+		if after, found := strings.CutPrefix(line, "local-zone:"); found {
+			after = strings.TrimSpace(after)
+			fields := strings.Fields(after)
+			if len(fields) > 1 {
+				localZone = strings.Trim(fields[0], `"`)
+			}
+			continue
+		}
+		// Only read "local-data-ptr: ..." line, it has all necessary information.
+		after, found := strings.CutPrefix(line, "local-data-ptr:")
+		if !found {
+			continue
+		}
+		after = strings.TrimSpace(after)
+		after = strings.Trim(after, `"`)
+		fields := strings.Fields(after)
+		if len(fields) != 2 {
+			continue
+		}
+		ip := fields[0]
+		name := strings.TrimSuffix(fields[1], "."+localZone)
+		hostsMap[ip] = append(hostsMap[ip], name)
+	}
+	return hostsMap
+}

internal/clientinfo/hostsfile_test.go

@@ -1,6 +1,7 @@
 package clientinfo
 
 import (
+	"strings"
 	"testing"
 )
 
@@ -31,3 +32,46 @@ func Test_hostsFile_LookupHostnameByIP(t *testing.T) {
 		})
 	}
 }
+
+func Test_parseHostEntriesConfFromReader(t *testing.T) {
+	const content = `local-zone: "localdomain" transparent
+local-data-ptr: "127.0.0.1 localhost"
+local-data: "localhost A 127.0.0.1"
+local-data: "localhost.localdomain A 127.0.0.1"
+local-data-ptr: "::1 localhost"
+local-data: "localhost AAAA ::1"
+local-data: "localhost.localdomain AAAA ::1"
+local-data-ptr: "10.0.10.227 OPNsense.localdomain"
+local-data: "OPNsense.localdomain A 10.0.10.227"
+local-data: "OPNsense A 10.0.10.227"
+local-data-ptr: "fe80::5a78:4e29:caa3:f9f7 OPNsense.localdomain"
+local-data: "OPNsense.localdomain AAAA fe80::5a78:4e29:caa3:f9f7"
+local-data: "OPNsense AAAA fe80::5a78:4e29:caa3:f9f7"
+local-data-ptr: "1.1.1.1 banana-party.local.com"
+local-data: "banana-party.local.com IN A 1.1.1.1"
+local-data-ptr: "1.1.1.1 cheese-land.lan"
+local-data: "cheese-land.lan IN A 1.1.1.1"
+`
+	r := strings.NewReader(content)
+	hostsMap := parseHostEntriesConfFromReader(r)
+	if len(hostsMap) != 5 {
+		t.Fatalf("unexpected number of entries, want 5, got: %d", len(hostsMap))
+	}
+	for ip, names := range hostsMap {
+		switch ip {
+		case "1.1.1.1":
+			for _, name := range names {
+				if name != "banana-party.local.com" && name != "cheese-land.lan" {
+					t.Fatalf("unexpected names for 1.1.1.1: %v", names)
+				}
+			}
+		case "10.0.10.227":
+			if len(names) != 1 {
+				t.Fatalf("unexpected names for 10.0.10.227: %v", names)
+			}
+			if names[0] != "OPNsense" {
+				t.Fatalf("unexpected name: %s", names[0])
+			}
+		}
+	}
+}

internal/clientinfo/mdns.go

@@ -1,11 +1,16 @@
 package clientinfo
 
 import (
+	"bufio"
+	"bytes"
 	"context"
 	"errors"
+	"io"
 	"net"
 	"net/netip"
 	"os"
+	"os/exec"
+	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -107,6 +112,7 @@ func (m *mdns) init(quitCh chan struct{}) error {
 
 	go m.probeLoop(v4ConnList, mdnsV4Addr, quitCh)
 	go m.probeLoop(v6ConnList, mdnsV6Addr, quitCh)
+	go m.getDataFromAvahiDaemonCache()
 
 	return nil
 }
@@ -212,6 +218,44 @@ func (m *mdns) probe(conns []*net.UDPConn, remoteAddr net.Addr) error {
 	return err
 }
 
+// getDataFromAvahiDaemonCache reads entries from avahi-daemon cache to update mdns data.
+func (m *mdns) getDataFromAvahiDaemonCache() {
+	if _, err := exec.LookPath("avahi-browse"); err != nil {
+		ctrld.ProxyLogger.Load().Debug().Err(err).Msg("could not find avahi-browse binary, skipping.")
+		return
+	}
+	// Run avahi-browse to discover services from cache:
+	//  - "-a" -> all services.
+	//  - "-r" -> resolve found services.
+	//  - "-p" -> parseable format.
+	//  - "-c" -> read from cache.
+	out, err := exec.Command("avahi-browse", "-a", "-r", "-p", "-c").Output()
+	if err != nil {
+		ctrld.ProxyLogger.Load().Debug().Err(err).Msg("could not browse services from avahi cache")
+		return
+	}
+	m.storeDataFromAvahiBrowseOutput(bytes.NewReader(out))
+}
+
+// storeDataFromAvahiBrowseOutput parses avahi-browse output from reader, then updating found data to mdns table.
+func (m *mdns) storeDataFromAvahiBrowseOutput(r io.Reader) {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		fields := strings.FieldsFunc(scanner.Text(), func(r rune) bool {
+			return r == ';'
+		})
+		if len(fields) < 8 || fields[0] != "=" {
+			continue
+		}
+		ip := fields[7]
+		name := normalizeHostname(fields[6])
+		// Only using cache value if we don't have existed one.
+		if _, loaded := m.name.LoadOrStore(ip, name); !loaded {
+			ctrld.ProxyLogger.Load().Debug().Msgf("found hostname: %q, ip: %q via avahi cache", name, ip)
+		}
+	}
+}
+
 func multicastInterfaces() ([]net.Interface, error) {
 	ifaces, err := net.Interfaces()
 	if err != nil {

internal/clientinfo/mdns_test.go

@@ -0,0 +1,27 @@
+package clientinfo
+
+import (
+	"strings"
+	"testing"
+)
+
+func Test_mdns_storeDataFromAvahiBrowseOutput(t *testing.T) {
+	const content = `+;wlp0s20f3;IPv6;Foo\032\0402\041;_companion-link._tcp;local
++;wlp0s20f3;IPv4;Foo\032\0402\041;_companion-link._tcp;local
+=;wlp0s20f3;IPv6;Foo\032\0402\041;_companion-link._tcp;local;Foo-2.local;192.168.1.123;64842;"rpBA=00:00:00:00:00:01" "rpHI=e6ae2cbbca0e" "rpAD=36566f4d850f" "rpVr=510.71.1" "rpHA=0ddc20fdddc8" "rpFl=0x30000" "rpHN=1d4a03afdefa" "rpMac=0"
+=;wlp0s20f3;IPv4;Foo\032\0402\041;_companion-link._tcp;local;Foo-2.local;192.168.1.123;64842;"rpBA=00:00:00:00:00:01" "rpHI=e6ae2cbbca0e" "rpAD=36566f4d850f" "rpVr=510.71.1" "rpHA=0ddc20fdddc8" "rpFl=0x30000" "rpHN=1d4a03afdefa" "rpMac=0"
+`
+	m := &mdns{}
+	m.storeDataFromAvahiBrowseOutput(strings.NewReader(content))
+	ip := "192.168.1.123"
+	val, loaded := m.name.LoadOrStore(ip, "")
+	if !loaded {
+		t.Fatal("missing Foo-2 data from mdns table")
+	}
+
+	wantHostname := "Foo-2"
+	hostname := val.(string)
+	if hostname != wantHostname {
+		t.Fatalf("unexpected hostname, want: %q, got: %q", wantHostname, hostname)
+	}
+}

internal/clientinfo/ndp.go

@@ -0,0 +1,219 @@
+package clientinfo
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/netip"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/mdlayher/ndp"
+
+	"github.com/Control-D-Inc/ctrld"
+)
+
+// ndpDiscover provides client discovery functionality using NDP protocol.
+type ndpDiscover struct {
+	mac sync.Map // ip  => mac
+	ip  sync.Map // mac => ip
+}
+
+// refresh re-scans the NDP table.
+func (nd *ndpDiscover) refresh() error {
+	nd.scan()
+	return nil
+}
+
+// LookupIP returns the ipv6 associated with the input MAC address.
+func (nd *ndpDiscover) LookupIP(mac string) string {
+	val, ok := nd.ip.Load(mac)
+	if !ok {
+		return ""
+	}
+	return val.(string)
+}
+
+// LookupMac returns the MAC address of the given IP address.
+func (nd *ndpDiscover) LookupMac(ip string) string {
+	val, ok := nd.mac.Load(ip)
+	if !ok {
+		return ""
+	}
+	return val.(string)
+}
+
+// String returns human-readable format of ndpDiscover.
+func (nd *ndpDiscover) String() string {
+	return "ndp"
+}
+
+// List returns all known IP addresses.
+func (nd *ndpDiscover) List() []string {
+	if nd == nil {
+		return nil
+	}
+	var ips []string
+	nd.ip.Range(func(key, value any) bool {
+		ips = append(ips, value.(string))
+		return true
+	})
+	nd.mac.Range(func(key, value any) bool {
+		ips = append(ips, key.(string))
+		return true
+	})
+	return ips
+}
+
+// listen listens on ipv6 link local for Neighbor Solicitation message
+// to update new neighbors information to ndp table.
+func (nd *ndpDiscover) listen(ctx context.Context) {
+	ifi, err := firstInterfaceWithV6LinkLocal()
+	if err != nil {
+		ctrld.ProxyLogger.Load().Debug().Err(err).Msg("failed to find valid ipv6")
+		return
+	}
+	c, ip, err := ndp.Listen(ifi, ndp.LinkLocal)
+	if err != nil {
+		ctrld.ProxyLogger.Load().Debug().Err(err).Msg("ndp listen failed")
+		return
+	}
+	defer c.Close()
+	ctrld.ProxyLogger.Load().Debug().Msgf("listening ndp on: %s", ip.String())
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+		}
+		_ = c.SetReadDeadline(time.Now().Add(30 * time.Second))
+		msg, _, from, readErr := c.ReadFrom()
+		if readErr != nil {
+			var opErr *net.OpError
+			if errors.As(readErr, &opErr) && (opErr.Timeout() || opErr.Temporary()) {
+				continue
+			}
+			ctrld.ProxyLogger.Load().Debug().Err(readErr).Msg("ndp read loop error")
+			return
+		}
+
+		// Only looks for neighbor solicitation message, since new clients
+		// which join network will broadcast this message to us.
+		am, ok := msg.(*ndp.NeighborSolicitation)
+		if !ok {
+			continue
+		}
+		fromIP := from.String()
+		for _, opt := range am.Options {
+			if lla, ok := opt.(*ndp.LinkLayerAddress); ok {
+				mac := lla.Addr.String()
+				nd.mac.Store(fromIP, mac)
+				nd.ip.Store(mac, fromIP)
+			}
+		}
+	}
+}
+
+// scanWindows populates NDP table using information from "netsh" command.
+func (nd *ndpDiscover) scanWindows(r io.Reader) {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 3 {
+			continue
+		}
+		if mac := parseMAC(fields[1]); mac != "" {
+			nd.mac.Store(fields[0], mac)
+			nd.ip.Store(mac, fields[0])
+		}
+	}
+}
+
+// scanUnix populates NDP table using information from "ndp" command.
+func (nd *ndpDiscover) scanUnix(r io.Reader) {
+	scanner := bufio.NewScanner(r)
+	scanner.Scan() // skip header
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 2 {
+			continue
+		}
+		if mac := parseMAC(fields[1]); mac != "" {
+			ip := fields[0]
+			if idx := strings.IndexByte(ip, '%'); idx != -1 {
+				ip = ip[:idx]
+			}
+			nd.mac.Store(ip, mac)
+			nd.ip.Store(mac, ip)
+		}
+	}
+}
+
+// normalizeMac ensure the given MAC address have the proper format
+// before being parsed.
+//
+// Example, changing "00:0:00:0:00:01" to "00:00:00:00:00:01", which
+// can be seen on Darwin.
+func normalizeMac(mac string) string {
+	if len(mac) == 17 {
+		return mac
+	}
+	// Windows use "-" instead of ":" as separator.
+	mac = strings.ReplaceAll(mac, "-", ":")
+	parts := strings.Split(mac, ":")
+	if len(parts) != 6 {
+		return ""
+	}
+	for i, c := range parts {
+		if len(c) == 1 {
+			parts[i] = "0" + c
+		}
+	}
+	return strings.Join(parts, ":")
+}
+
+// parseMAC parses the input MAC, doing normalization,
+// and return the result after calling net.ParseMac function.
+func parseMAC(mac string) string {
+	hw, _ := net.ParseMAC(normalizeMac(mac))
+	return hw.String()
+}
+
+// firstInterfaceWithV6LinkLocal returns the first interface which is capable of using NDP.
+func firstInterfaceWithV6LinkLocal() (*net.Interface, error) {
+	ifis, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, ifi := range ifis {
+		// Skip if iface is down/loopback/non-multicast.
+		if ifi.Flags&net.FlagUp == 0 || ifi.Flags&net.FlagLoopback != 0 || ifi.Flags&net.FlagMulticast == 0 {
+			continue
+		}
+
+		addrs, err := ifi.Addrs()
+		if err != nil {
+			return nil, err
+		}
+
+		for _, addr := range addrs {
+			ipNet, ok := addr.(*net.IPNet)
+			if !ok {
+				continue
+			}
+			ip, ok := netip.AddrFromSlice(ipNet.IP)
+			if !ok {
+				return nil, fmt.Errorf("invalid ip address: %s", ipNet.String())
+			}
+			if ip.Is6() && !ip.Is4In6() {
+				return &ifi, nil
+			}
+		}
+	}
+	return nil, errors.New("no interface can be used")
+}

internal/clientinfo/ndp_linux.go

@@ -0,0 +1,24 @@
+package clientinfo
+
+import (
+	"github.com/vishvananda/netlink"
+
+	"github.com/Control-D-Inc/ctrld"
+)
+
+// scan populates NDP table using information from system mappings.
+func (nd *ndpDiscover) scan() {
+	neighs, err := netlink.NeighList(0, netlink.FAMILY_V6)
+	if err != nil {
+		ctrld.ProxyLogger.Load().Warn().Err(err).Msg("could not get neigh list")
+		return
+	}
+
+	for _, n := range neighs {
+		ip := n.IP.String()
+		mac := n.HardwareAddr.String()
+		nd.mac.Store(ip, mac)
+		nd.ip.Store(mac, ip)
+	}
+
+}

internal/clientinfo/ndp_others.go

@@ -0,0 +1,31 @@
+//go:build !linux
+
+package clientinfo
+
+import (
+	"bytes"
+	"os/exec"
+	"runtime"
+
+	"github.com/Control-D-Inc/ctrld"
+)
+
+// scan populates NDP table using information from system mappings.
+func (nd *ndpDiscover) scan() {
+	switch runtime.GOOS {
+	case "windows":
+		data, err := exec.Command("netsh", "interface", "ipv6", "show", "neighbors").Output()
+		if err != nil {
+			ctrld.ProxyLogger.Load().Warn().Err(err).Msg("could not query ndp table")
+			return
+		}
+		nd.scanWindows(bytes.NewReader(data))
+	default:
+		data, err := exec.Command("ndp", "-an").Output()
+		if err != nil {
+			ctrld.ProxyLogger.Load().Warn().Err(err).Msg("could not query ndp table")
+			return
+		}
+		nd.scanUnix(bytes.NewReader(data))
+	}
+}

internal/clientinfo/ndp_test.go

@@ -0,0 +1,64 @@
+package clientinfo
+
+import (
+	"strings"
+	"sync"
+	"testing"
+)
+
+func Test_ndpDiscover_scanUnix(t *testing.T) {
+	r := strings.NewReader(`Neighbor                                Linklayer Address  Netif Expire    St Flgs Prbs
+2405:4802:1f90:fda0:1459:ec89:523d:3583 00:0:00:0:00:01      en0 permanent R
+2405:4802:1f90:fda0:186b:c54a:1370:c196 (incomplete)         en0 expired   N
+2405:4802:1f90:fda0:88de:14ef:6a8c:579a 00:0:00:0:00:02      en0 permanent R
+fe80::1%lo0                             (incomplete)         lo0 permanent R
+`)
+	nd := &ndpDiscover{}
+	nd.scanUnix(r)
+
+	for _, m := range []*sync.Map{&nd.mac, &nd.ip} {
+		count := 0
+		m.Range(func(key, value any) bool {
+			count++
+			return true
+		})
+		if count != 2 {
+			t.Errorf("unexpected count, want 2, got: %d", count)
+		}
+	}
+}
+
+func Test_ndpDiscover_scanWindows(t *testing.T) {
+	r := strings.NewReader(`Interface 14: Wi-Fi
+
+
+Internet Address                              Physical Address   Type
+--------------------------------------------  -----------------  -----------
+2405:4802:1f90:fda0:ffff:ffff:ffff:ff88       00-00-00-00-00-00  Unreachable
+fe80::1                                       60-57-47-21-dd-00  Reachable (Router)
+fe80::6257:47ff:fe21:dd00                     60-57-47-21-dd-00  Reachable (Router)
+ff02::1                                       33-33-00-00-00-01  Permanent
+ff02::2                                       33-33-00-00-00-02  Permanent
+ff02::c                                       33-33-00-00-00-0c  Permanent
+`)
+	nd := &ndpDiscover{}
+	nd.scanWindows(r)
+
+	count := 0
+	nd.mac.Range(func(key, value any) bool {
+		count++
+		return true
+	})
+	if count != 6 {
+		t.Errorf("unexpected count, want 6, got: %d", count)
+	}
+
+	count = 0
+	nd.ip.Range(func(key, value any) bool {
+		count++
+		return true
+	})
+	if count != 5 {
+		t.Errorf("unexpected count, want 5, got: %d", count)
+	}
+}

internal/clientinfo/ubios.go

@@ -0,0 +1,78 @@
+package clientinfo
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"os/exec"
+	"strings"
+	"sync"
+
+	"github.com/Control-D-Inc/ctrld/internal/router"
+	"github.com/Control-D-Inc/ctrld/internal/router/ubios"
+)
+
+// ubiosDiscover provides client discovery functionality on Ubios routers.
+type ubiosDiscover struct {
+	hostname sync.Map // mac => hostname
+}
+
+// refresh reloads unifi devices from database.
+func (u *ubiosDiscover) refresh() error {
+	if router.Name() != ubios.Name {
+		return nil
+	}
+	return u.refreshDevices()
+}
+
+// LookupHostnameByIP returns hostname for given IP.
+func (u *ubiosDiscover) LookupHostnameByIP(ip string) string {
+	return ""
+}
+
+// LookupHostnameByMac returns unifi device custom hostname for the given MAC address.
+func (u *ubiosDiscover) LookupHostnameByMac(mac string) string {
+	val, ok := u.hostname.Load(mac)
+	if !ok {
+		return ""
+	}
+	return val.(string)
+}
+
+// refreshDevices updates unifi devices name from local mongodb.
+func (u *ubiosDiscover) refreshDevices() error {
+	cmd := exec.Command("/usr/bin/mongo", "localhost:27117/ace", "--quiet", "--eval", `
+		DBQuery.shellBatchSize = 256;
+		db.user.find({name: {$exists: true, $ne: ""}}, {_id:0, mac:1, name:1});`)
+	b, err := cmd.Output()
+	if err != nil {
+		return err
+	}
+	return u.storeDevices(bytes.NewReader(b))
+}
+
+// storeDevices saves unifi devices name for caching.
+func (u *ubiosDiscover) storeDevices(r io.Reader) error {
+	decoder := json.NewDecoder(r)
+	device := struct {
+		MAC  string
+		Name string
+	}{}
+	for {
+		err := decoder.Decode(&device)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		mac := strings.ToLower(device.MAC)
+		u.hostname.Store(mac, normalizeHostname(device.Name))
+	}
+	return nil
+}
+
+// String returns human-readable format of ubiosDiscover.
+func (u *ubiosDiscover) String() string {
+	return "ubios"
+}

internal/clientinfo/ubios_test.go

@@ -0,0 +1,43 @@
+package clientinfo
+
+import (
+	"strings"
+	"testing"
+)
+
+func Test_ubiosDiscover_storeDevices(t *testing.T) {
+	ud := &ubiosDiscover{}
+	r := strings.NewReader(`{ "mac": "00:00:00:00:00:01", "name": "device 1" }
+{ "mac": "00:00:00:00:00:02", "name": "device 2" }
+`)
+	if err := ud.storeDevices(r); err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		name     string
+		mac      string
+		hostname string
+	}{
+		{"device 1", "00:00:00:00:00:01", "device 1"},
+		{"device 2", "00:00:00:00:00:02", "device 2"},
+		{"non-existed", "00:00:00:00:00:03", ""},
+	}
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			if got := ud.LookupHostnameByMac(tc.mac); got != tc.hostname {
+				t.Errorf("hostname mismatched, want: %q, got: %q", tc.hostname, got)
+			}
+		})
+	}
+
+	// Test for invalid input.
+	r = strings.NewReader(`{ "mac": "00:00:00:00:00:01", "name": "device 1"`)
+	if err := ud.storeDevices(r); err == nil {
+		t.Fatal("expected error, got nil")
+	} else {
+		t.Log(err)
+	}
+}

internal/controld/config.go

@@ -35,8 +35,9 @@ type ResolverConfig struct {
 	Ctrld struct {
 		CustomConfig string `json:"custom_config"`
 	} `json:"ctrld"`
-	Exclude []string `json:"exclude"`
-	UID     string   `json:"uid"`
+	Exclude         []string `json:"exclude"`
+	UID             string   `json:"uid"`
+	DeactivationPin *int64   `json:"deactivation_pin,omitempty"`
 }
 
 type utilityResponse struct {

internal/net/net.go

@@ -16,8 +16,8 @@ import (
 
 const (
 	controldIPv6Test = "ipv6.controld.io"
-	v4BootstrapDNS   = "76.76.2.0:53"
-	v6BootstrapDNS   = "[2606:1a40::]:53"
+	v4BootstrapDNS   = "76.76.2.22:53"
+	v6BootstrapDNS   = "[2606:1a40::22]:53"
 )
 
 var Dialer = &net.Dialer{

internal/router/dnsmasq/dnsmasq.go

@@ -1,12 +1,9 @@
 package dnsmasq
 
 import (
-	"bytes"
 	"errors"
-	"fmt"
 	"html/template"
 	"net"
-	"os"
 	"path/filepath"
 	"strings"
 
@@ -18,12 +15,12 @@ no-resolv
 {{- range .Upstreams}}
 server={{ .IP }}#{{ .Port }}
 {{- end}}
-{{- if .SendClientInfo}}
 add-mac
 add-subnet=32,128
-{{- end}}
 {{- if .CacheDisabled}}
 cache-size=0
+{{- else}}
+max-cache-ttl=0
 {{- end}}
 `
 
@@ -45,12 +42,10 @@ if [ -n "$pid" ] && [ -f "/proc/${pid}/cmdline" ]; then
   {{- range .Upstreams}}
   pc_append "server={{ .IP }}#{{ .Port }}" "$config_file"
   {{- end}}
-  {{- if .SendClientInfo}}
   pc_delete "add-mac" "$config_file"
   pc_delete "add-subnet" "$config_file"
   pc_append "add-mac" "$config_file"                # add client mac
   pc_append "add-subnet=32,128" "$config_file"      # add client ip
-  {{- end}}
   pc_delete "dnssec" "$config_file"                 # disable DNSSEC
   pc_delete "trust-anchor=" "$config_file"          # disable DNSSEC
   pc_delete "cache-size=" "$config_file"
@@ -72,11 +67,18 @@ type Upstream struct {
 	Port int
 }
 
+// ConfTmpl generates dnsmasq configuration from ctrld config.
 func ConfTmpl(tmplText string, cfg *ctrld.Config) (string, error) {
-	return ConfTmplWitchCacheDisabled(tmplText, cfg, true)
+	return ConfTmplWithCacheDisabled(tmplText, cfg, true)
 }
 
-func ConfTmplWitchCacheDisabled(tmplText string, cfg *ctrld.Config, cacheDisabled bool) (string, error) {
+// ConfTmplWithCacheDisabled is like ConfTmpl, but the caller can control whether
+// dnsmasq cache is disabled using cacheDisabled parameter.
+//
+// Generally, the caller should use ConfTmpl, but on some routers which dnsmasq config may be changed
+// after ctrld started (like EdgeOS/Ubios, Firewalla ...), dnsmasq cache should not be disabled because
+// the cache-size=0 generated by ctrld will conflict with router's generated config.
+func ConfTmplWithCacheDisabled(tmplText string, cfg *ctrld.Config, cacheDisabled bool) (string, error) {
 	listener := cfg.FirstListener()
 	if listener == nil {
 		return "", errors.New("missing listener")
@@ -86,26 +88,27 @@ func ConfTmplWitchCacheDisabled(tmplText string, cfg *ctrld.Config, cacheDisable
 		ip = "127.0.0.1"
 	}
 	upstreams := []Upstream{{IP: ip, Port: listener.Port}}
-	return confTmpl(tmplText, upstreams, cfg.HasUpstreamSendClientInfo(), cacheDisabled)
+	return confTmpl(tmplText, upstreams, cacheDisabled)
 }
 
+// FirewallaConfTmpl generates dnsmasq config for Firewalla routers.
 func FirewallaConfTmpl(tmplText string, cfg *ctrld.Config) (string, error) {
+	// If ctrld listen on all interfaces, generating config for all of them.
 	if lc := cfg.FirstListener(); lc != nil && (lc.IP == "0.0.0.0" || lc.IP == "") {
-		return confTmpl(tmplText, firewallaUpstreams(lc.Port), cfg.HasUpstreamSendClientInfo(), true)
+		return confTmpl(tmplText, firewallaUpstreams(lc.Port), false)
 	}
-	return ConfTmpl(tmplText, cfg)
+	// Otherwise, generating config for the specific listener from ctrld's config.
+	return ConfTmplWithCacheDisabled(tmplText, cfg, false)
 }
 
-func confTmpl(tmplText string, upstreams []Upstream, sendClientInfo, cacheDisabled bool) (string, error) {
+func confTmpl(tmplText string, upstreams []Upstream, cacheDisabled bool) (string, error) {
 	tmpl := template.Must(template.New("").Parse(tmplText))
 	var to = &struct {
-		SendClientInfo bool
-		Upstreams      []Upstream
-		CacheDisabled  bool
+		Upstreams     []Upstream
+		CacheDisabled bool
 	}{
-		SendClientInfo: sendClientInfo,
-		Upstreams:      upstreams,
-		CacheDisabled:  cacheDisabled,
+		Upstreams:     upstreams,
+		CacheDisabled: cacheDisabled,
 	}
 	var sb strings.Builder
 	if err := tmpl.Execute(&sb, to); err != nil {
@@ -136,20 +139,6 @@ func firewallaDnsmasqConfFiles() ([]string, error) {
 	return filepath.Glob("/home/pi/firerouter/etc/dnsmasq.dns.*.conf")
 }
 
-// firewallUpdateConf updates all firewall config files using given function.
-func firewallUpdateConf(update func(conf string) error) error {
-	confFiles, err := firewallaDnsmasqConfFiles()
-	if err != nil {
-		return err
-	}
-	for _, conf := range confFiles {
-		if err := update(conf); err != nil {
-			return fmt.Errorf("%s: %w", conf, err)
-		}
-	}
-	return nil
-}
-
 // FirewallaSelfInterfaces returns list of interfaces that will be configured with default dnsmasq setup on Firewalla.
 func FirewallaSelfInterfaces() []*net.Interface {
 	matches, err := firewallaDnsmasqConfFiles()
@@ -166,32 +155,3 @@ func FirewallaSelfInterfaces() []*net.Interface {
 	}
 	return ifaces
 }
-
-// FirewallaDisableCache comments out "cache-size" line in all firewalla dnsmasq config files.
-func FirewallaDisableCache() error {
-	return firewallUpdateConf(DisableCache)
-}
-
-// FirewallaEnableCache un-comments out "cache-size" line in all firewalla dnsmasq config files.
-func FirewallaEnableCache() error {
-	return firewallUpdateConf(EnableCache)
-}
-
-// DisableCache comments out "cache-size" line in dnsmasq config file.
-func DisableCache(conf string) error {
-	return replaceFileContent(conf, "\ncache-size=", "\n#cache-size=")
-}
-
-// EnableCache un-comments "cache-size" line in dnsmasq config file.
-func EnableCache(conf string) error {
-	return replaceFileContent(conf, "\n#cache-size=", "\ncache-size=")
-}
-
-func replaceFileContent(filename, old, new string) error {
-	content, err := os.ReadFile(filename)
-	if err != nil {
-		return err
-	}
-	content = bytes.ReplaceAll(content, []byte(old), []byte(new))
-	return os.WriteFile(filename, content, 0644)
-}

internal/router/edgeos/edgeos.go

@@ -20,11 +20,15 @@ const (
 	usgDNSMasqConfigPath       = "/etc/dnsmasq.conf"
 	usgDNSMasqBackupConfigPath = "/etc/dnsmasq.conf.bak"
 	toggleContentFilteringLink = "https://community.ui.com/questions/UDM-Pro-disable-enable-DNS-filtering/e2cc4060-e56a-4139-b200-62d7f773ff8f"
+	toggleDnsShieldLink        = "https://community.ui.com/questions/UniFi-OS-3-2-7-DNS-Shield-Missing/d3a85905-4ce0-4fe4-8bf0-6cb04f21371d"
 )
 
 var ErrContentFilteringEnabled = fmt.Errorf(`the "Content Filtering" feature" is enabled, which is conflicted with ctrld.\n
 To disable it, folowing instruction here: %s`, toggleContentFilteringLink)
 
+var ErrDnsShieldEnabled = fmt.Errorf(`the "DNS Shield" feature" is enabled, which is conflicted with ctrld.\n
+To disable it, folowing screenshot here: %s`, toggleDnsShieldLink)
+
 type EdgeOS struct {
 	cfg   *ctrld.Config
 	isUSG bool
@@ -50,6 +54,11 @@ func (e *EdgeOS) Install(_ *service.Config) error {
 	if ContentFilteringEnabled() {
 		return ErrContentFilteringEnabled
 	}
+	// If "DNS Shield" is enabled, UniFi OS will spawn dnscrypt-proxy process, and route all DNS queries to it. So
+	// reporting an error and guiding users to disable the feature using UniFi OS web UI.
+	if DnsShieldEnabled() {
+		return ErrDnsShieldEnabled
+	}
 	return nil
 }
 
@@ -109,7 +118,7 @@ func (e *EdgeOS) setupUSG() error {
 		sb.WriteString(line)
 	}
 
-	data, err := dnsmasq.ConfTmplWitchCacheDisabled(dnsmasq.ConfigContentTmpl, e.cfg, false)
+	data, err := dnsmasq.ConfTmplWithCacheDisabled(dnsmasq.ConfigContentTmpl, e.cfg, false)
 	if err != nil {
 		return err
 	}
@@ -127,7 +136,7 @@ func (e *EdgeOS) setupUSG() error {
 }
 
 func (e *EdgeOS) setupUDM() error {
-	data, err := dnsmasq.ConfTmplWitchCacheDisabled(dnsmasq.ConfigContentTmpl, e.cfg, false)
+	data, err := dnsmasq.ConfTmplWithCacheDisabled(dnsmasq.ConfigContentTmpl, e.cfg, false)
 	if err != nil {
 		return err
 	}
@@ -169,6 +178,16 @@ func ContentFilteringEnabled() bool {
 	return err == nil && !st.IsDir()
 }
 
+// DnsShieldEnabled reports whether DNS Shield is enabled.
+// See: https://community.ui.com/releases/UniFi-OS-Dream-Machines-3-2-7/251dfc1e-f4dd-4264-a080-3be9d8b9e02b
+func DnsShieldEnabled() bool {
+	buf, err := os.ReadFile("/var/run/dnsmasq.conf.d/dns.conf")
+	if err != nil {
+		return false
+	}
+	return bytes.Contains(buf, []byte("server=127.0.0.1#5053"))
+}
+
 func LeaseFileDir() string {
 	if checkUSG() {
 		return ""

internal/router/firewalla/firewalla.go

@@ -65,11 +65,6 @@ func (f *Firewalla) Setup() error {
 		return fmt.Errorf("writing ctrld config: %w", err)
 	}
 
-	// Disable dnsmasq cache.
-	if err := dnsmasq.FirewallaDisableCache(); err != nil {
-		return err
-	}
-
 	// Restart dnsmasq service.
 	if err := restartDNSMasq(); err != nil {
 		return fmt.Errorf("restartDNSMasq: %w", err)
@@ -87,11 +82,6 @@ func (f *Firewalla) Cleanup() error {
 		return fmt.Errorf("removing ctrld config: %w", err)
 	}
 
-	// Enable dnsmasq cache.
-	if err := dnsmasq.FirewallaEnableCache(); err != nil {
-		return err
-	}
-
 	// Restart dnsmasq service.
 	if err := restartDNSMasq(); err != nil {
 		return fmt.Errorf("restartDNSMasq: %w", err)

internal/router/os_freebsd.go

@@ -137,20 +137,9 @@ rcvar="${name}_enable"
 pidfile="/var/run/${name}.pid"
 child_pidfile="/var/run/${name}_child.pid"
 command="/usr/sbin/daemon"
-daemon_args="-P ${pidfile} -p ${child_pidfile} -t \"${name}: daemon\"{{if .WorkingDirectory}} -c {{.WorkingDirectory}}{{end}}"
+daemon_args="-r -P ${pidfile} -p ${child_pidfile} -t \"${name}: daemon\"{{if .WorkingDirectory}} -c {{.WorkingDirectory}}{{end}}"
 command_args="${daemon_args} {{.Path}}{{range .Arguments}} {{.}}{{end}}"
 
-stop_cmd="ctrld_stop"
-
-ctrld_stop() {
-  pid=$(cat ${pidfile})
-  child_pid=$(cat ${child_pidfile})
-  if [ -e "${child_pidfile}" ]; then
-    kill -s TERM "${child_pid}"
-    wait_for_pids "${child_pid}" "${pidfile}"
-  fi
-}
-
 load_rc_config "${name}"
 run_rc_command "$1"
 `

internal/router/router.go

@@ -199,7 +199,7 @@ func distroName() string {
 		return merlin.Name
 	case haveFile("/etc/openwrt_version"):
 		return openwrt.Name
-	case haveDir("/data/unifi"):
+	case isUbios():
 		return ubios.Name
 	case bytes.HasPrefix(unameU(), []byte("synology")):
 		return synology.Name
@@ -234,3 +234,14 @@ func unameU() []byte {
 	out, _ := exec.Command("uname", "-u").Output()
 	return out
 }
+
+// isUbios reports whether the current machine is running on Ubios.
+func isUbios() bool {
+	if haveDir("/data/unifi") {
+		return true
+	}
+	if err := exec.Command("ubnt-device-info", "firmware").Run(); err == nil {
+		return true
+	}
+	return false
+}

internal/router/ubios/ubios.go

@@ -36,6 +36,10 @@ func (u *Ubios) Install(config *service.Config) error {
 	if edgeos.ContentFilteringEnabled() {
 		return edgeos.ErrContentFilteringEnabled
 	}
+	// See comment in (*edgeos.EdgeOS).Install method.
+	if edgeos.DnsShieldEnabled() {
+		return edgeos.ErrDnsShieldEnabled
+	}
 	return nil
 }
 
@@ -51,17 +55,13 @@ func (u *Ubios) Setup() error {
 	if u.cfg.FirstListener().IsDirectDnsListener() {
 		return nil
 	}
-	data, err := dnsmasq.ConfTmpl(dnsmasq.ConfigContentTmpl, u.cfg)
+	data, err := dnsmasq.ConfTmplWithCacheDisabled(dnsmasq.ConfigContentTmpl, u.cfg, false)
 	if err != nil {
 		return err
 	}
 	if err := os.WriteFile(ubiosDNSMasqConfigPath, []byte(data), 0600); err != nil {
 		return err
 	}
-	// Disable dnsmasq cache.
-	if err := dnsmasq.DisableCache(ubiosDNSMasqDnsConfigPath); err != nil {
-		return err
-	}
 	// Restart dnsmasq service.
 	if err := restartDNSMasq(); err != nil {
 		return err
@@ -77,10 +77,6 @@ func (u *Ubios) Cleanup() error {
 	if err := os.Remove(ubiosDNSMasqConfigPath); err != nil {
 		return err
 	}
-	// Enable dnsmasq cache.
-	if err := dnsmasq.EnableCache(ubiosDNSMasqDnsConfigPath); err != nil {
-		return err
-	}
 	// Restart dnsmasq service.
 	if err := restartDNSMasq(); err != nil {
 		return err

resolver.go

@@ -30,7 +30,7 @@ const (
 	ResolverTypePrivate = "private"
 )
 
-var bootstrapDNS = "76.76.2.0"
+const bootstrapDNS = "76.76.2.22"
 
 // or is the Resolver used for ResolverTypeOS.
 var or = &osResolver{nameservers: defaultNameservers()}

scripts/build.sh

@@ -72,17 +72,9 @@ build() {
       if [ "$CGO_ENABLED" = "0" ]; then
         binary=${binary}-nocgo
       fi
+      GOOS=${goos} GOARCH=${goarch} GOARM=${3} "$go" generate ./...
       GOOS=${goos} GOARCH=${goarch} GOARM=${3} "$go" build -ldflags="$ldflags" -o "$binary" ./cmd/ctrld
       compress "$binary"
-
-      if [ -z "${CTRLD_NO_QF}" ]; then
-        binary_qf=${executable_name}-qf-${goos}-${goarch}v${3}
-        if [ "$CGO_ENABLED" = "0" ]; then
-          binary_qf=${binary_qf}-nocgo
-        fi
-        GOOS=${goos} GOARCH=${goarch} GOARM=${3} "$go" build -ldflags="$ldflags" -tags=qf -o "$binary_qf" ./cmd/ctrld
-        compress "$binary_qf"
-      fi
       ;;
     *)
       # GOMIPS is required for linux/mips: https://nileshgr.com/2020/02/16/golang-on-openwrt-mips/
@@ -90,17 +82,9 @@ build() {
       if [ "$CGO_ENABLED" = "0" ]; then
         binary=${binary}-nocgo
       fi
+      GOOS=${goos} GOARCH=${goarch} GOMIPS=softfloat "$go" generate ./...
       GOOS=${goos} GOARCH=${goarch} GOMIPS=softfloat "$go" build -ldflags="$ldflags" -o "$binary" ./cmd/ctrld
       compress "$binary"
-
-      if [ -z "${CTRLD_NO_QF}" ]; then
-        binary_qf=${executable_name}-qf-${goos}-${goarch}
-        if [ "$CGO_ENABLED" = "0" ]; then
-          binary_qf=${binary_qf}-nocgo
-        fi
-        GOOS=${goos} GOARCH=${goarch} GOMIPS=softfloat "$go" build -ldflags="$ldflags" -tags=qf -o "$binary_qf" ./cmd/ctrld
-        compress "$binary_qf"
-      fi
       ;;
   esac
 }

scripts/build_lib.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+
+# This script is used to locally build Android .aar library and iOS .xcframework from ctrld source using go mobile tool.
+
+# Requirements:
+#   - Android NDK (version 23+)
+#   - Android SDK (version 33+)
+#   - Xcode 15 + Build tools
+#   - Go 1.21
+#   - Git
+# usage: $ ./build_lib.sh v1.3.4
+
+TAG="$1"
+# Hacky way to replace version info.
+update_versionInfo() {
+    local file="$1/ctrld/cmd/cli/cli.go"
+    local tag="$2"
+    local commit="$3"
+    awk -v tag="$tag" -v commit="$commit" '
+        BEGIN { version_updated = 0; commit_updated = 0 }
+        /^\tversion/ {
+            sub(/= ".+"/, "= \"" tag "\"");
+            version_updated = 1;
+        }
+        /^\tcommit/ {
+            sub(/= ".+"/, "= \"" commit "\"");
+            commit_updated = 1;
+        }
+        { print }
+        END {
+            if (version_updated == 0) {
+                print "\tversion = \"" tag "\"";
+            }
+            if (commit_updated == 0) {
+                print "\tcommit = \"" commit "\"";
+            }
+        }
+    ' "$file" > "$file.tmp" && mv "$file.tmp" "$file"
+}
+export ANDROID_NDK_HOME=~/Library/Android/sdk/ndk/23.0.7599858
+mkdir bin
+cd bin || exit
+root=$(pwd)
+# Get source from github and switch to tag
+git clone --depth 1 --branch "$TAG" https://github.com/Control-D-Inc/ctrld.git
+# Prepare gomobile tool
+sourcePath=./ctrld/cmd/ctrld_library
+cd $sourcePath || exit
+go mod tidy
+go install golang.org/x/mobile/cmd/gomobile@latest
+go get golang.org/x/mobile/bind
+gomobile init
+# Prepare build info
+buildDir=$root/../build
+mkdir -p "$buildDir"
+COMMIT=$(git rev-parse HEAD)
+update_versionInfo "$root" "$TAG" "$COMMIT"
+ldflags="-s -w"
+# Build
+gomobile bind -target ios/arm64 -ldflags="$ldflags" -o "$buildDir"/ctrld-"$TAG".xcframework || exit
+gomobile bind -ldflags="$ldflags" -o "$buildDir"/ctrld-"$TAG".aar || exit
+# Clean up
+rm -r "$root"
+echo "Successfully built Ctrld library $TAG($COMMIT)."