Merge pull request #37 from Control-D-Inc/release-branch-v1.1.4

Release branch v1.1.4

.goreleaser-darwin.yaml

@@ -9,6 +9,8 @@ builds:
       - -trimpath
     ldflags:
       - -s -w
+      - -X main.version={{.Version}}
+      - -X main.commit={{.Commit}}
     goos:
       - darwin
     goarch:

.goreleaser-qf.yaml

@@ -9,6 +9,8 @@ builds:
       - -trimpath
     ldflags:
       - -s -w
+      - -X main.version={{.Version}}
+      - -X main.commit={{.Commit}}
     goos:
       - darwin
       - linux

.goreleaser.yaml

@@ -9,6 +9,8 @@ builds:
       - -trimpath
     ldflags:
       - -s -w
+      - -X main.version={{.Version}}
+      - -X main.commit={{.Commit}}
     goos:
       - linux
       - freebsd

cmd/ctrld/cli.go

@@ -15,10 +15,12 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
 
+	"github.com/cuonglm/osinfo"
 	"github.com/go-playground/validator/v10"
 	"github.com/kardianos/service"
 	"github.com/miekg/dns"
@@ -35,6 +37,11 @@ import (
 
 const selfCheckFQDN = "verify.controld.com"
 
+var (
+	version = "dev"
+	commit  = "none"
+)
+
 var (
 	v                    = viper.NewWithOptions(viper.KeyDelimiter("::"))
 	defaultConfigWritten = false
@@ -61,17 +68,28 @@ _/ ___\   __\_  __ \  |   / __ |
      \/ dns forwarding proxy  \/
 `
 
+var rootCmd = &cobra.Command{
+	Use:     "ctrld",
+	Short:   strings.TrimLeft(rootShortDesc, "\n"),
+	Version: curVersion(),
+}
+
+func curVersion() string {
+	if version != "dev" {
+		version = "v" + version
+	}
+	if len(commit) > 7 {
+		commit = commit[:7]
+	}
+	return fmt.Sprintf("%s-%s", version, commit)
+}
+
 func initCLI() {
 	// Enable opening via explorer.exe on Windows.
 	// See: https://github.com/spf13/cobra/issues/844.
 	cobra.MousetrapHelpText = ""
 	cobra.EnableCommandSorting = false
 
-	rootCmd := &cobra.Command{
-		Use:     "ctrld",
-		Short:   strings.TrimLeft(rootShortDesc, "\n"),
-		Version: "1.1.2",
-	}
 	rootCmd.PersistentFlags().CountVarP(
 		&verbose,
 		"verbose",
@@ -89,6 +107,35 @@ func initCLI() {
 			if daemon && runtime.GOOS == "windows" {
 				log.Fatal("Cannot run in daemon mode. Please install a Windows service.")
 			}
+
+			waitCh := make(chan struct{})
+			stopCh := make(chan struct{})
+			if !daemon {
+				// We need to call s.Run() as soon as possible to response to the OS manager, so it
+				// can see ctrld is running and don't mark ctrld as failed service.
+				go func() {
+					p := &prog{
+						waitCh: waitCh,
+						stopCh: stopCh,
+					}
+					s, err := service.New(p, svcConfig)
+					if err != nil {
+						mainLog.Fatal().Err(err).Msg("failed create new service")
+					}
+					serviceLogger, err := s.Logger(nil)
+					if err != nil {
+						mainLog.Error().Err(err).Msg("failed to get service logger")
+						return
+					}
+
+					if err := s.Run(); err != nil {
+						if sErr := serviceLogger.Error(err); sErr != nil {
+							mainLog.Error().Err(sErr).Msg("failed to write service log")
+						}
+						mainLog.Error().Err(err).Msg("failed to start service")
+					}
+				}()
+			}
 			noConfigStart := isNoConfigStart(cmd)
 			writeDefaultConfig := !noConfigStart && configBase64 == ""
 			configs := []struct {
@@ -112,7 +159,11 @@ func initCLI() {
 			if err := v.Unmarshal(&cfg); err != nil {
 				log.Fatalf("failed to unmarshal config: %v", err)
 			}
-			fmt.Println("starting ctrld...")
+
+			log.Printf("starting ctrld %s\n", curVersion())
+			oi := osinfo.New()
+			log.Printf("os: %s\n", oi.String())
+
 			// Wait for network up.
 			if !ctrldnet.Up() {
 				log.Fatal("network is not up yet")
@@ -149,22 +200,8 @@ func initCLI() {
 				os.Exit(0)
 			}
 
-			s, err := service.New(&prog{}, svcConfig)
-			if err != nil {
-				mainLog.Fatal().Err(err).Msg("failed create new service")
-			}
-			serviceLogger, err := s.Logger(nil)
-			if err != nil {
-				mainLog.Error().Err(err).Msg("failed to get service logger")
-				return
-			}
-
-			if err := s.Run(); err != nil {
-				if sErr := serviceLogger.Error(err); sErr != nil {
-					mainLog.Error().Err(sErr).Msg("failed to write service log")
-				}
-				mainLog.Error().Err(err).Msg("failed to start service")
-			}
+			close(waitCh)
+			<-stopCh
 		},
 	}
 	runCmd.Flags().BoolVarP(&daemon, "daemon", "d", false, "Run as daemon")
@@ -346,12 +383,19 @@ func initCLI() {
 			}
 		},
 	}
+	if runtime.GOOS == "darwin" {
+		// On darwin, running status command without privileges may return wrong information.
+		statusCmd.PreRun = checkHasElevatedPrivilege
+	}
 
 	uninstallCmd := &cobra.Command{
 		PreRun: checkHasElevatedPrivilege,
 		Use:    "uninstall",
 		Short:  "Stop and uninstall the ctrld service",
-		Args:   cobra.NoArgs,
+		Long: `Stop and uninstall the ctrld service.
+
+NOTE: Uninstalling will set DNS to values provided by DHCP.`,
+		Args: cobra.NoArgs,
 		Run: func(cmd *cobra.Command, args []string) {
 			prog := &prog{}
 			s, err := service.New(prog, svcConfig)
@@ -365,13 +409,16 @@ func initCLI() {
 			}
 			initLogging()
 			if doTasks(tasks) {
+				if iface == "" {
+					iface = "auto"
+				}
 				prog.resetDNS()
 				mainLog.Info().Msg("Service uninstalled")
 				return
 			}
 		},
 	}
-	uninstallCmd.Flags().StringVarP(&iface, "iface", "", "auto", `Reset DNS setting for iface, "auto" means the default interface gateway`)
+	uninstallCmd.Flags().StringVarP(&iface, "iface", "", "", `Reset DNS setting for iface, use "auto" for the default gateway interface`)
 
 	listIfacesCmd := &cobra.Command{
 		Use:   "list",
@@ -500,15 +547,8 @@ func readConfigFile(writeDefaultConfig bool) bool {
 	// If err == nil, there's a config supplied via `--config`, no default config written.
 	err := v.ReadInConfig()
 	if err == nil {
-		fmt.Println("loading config file from:", v.ConfigFileUsed())
+		log.Println("loading config file from:", v.ConfigFileUsed())
 		defaultConfigFile = v.ConfigFileUsed()
-		v.OnConfigChange(func(in fsnotify.Event) {
-			if err := v.UnmarshalKey("listener", &cfg.Listener); err != nil {
-				log.Printf("failed to unmarshal listener config: %v", err)
-				return
-			}
-		})
-		v.WatchConfig()
 		return true
 	}
 
@@ -521,7 +561,7 @@ func readConfigFile(writeDefaultConfig bool) bool {
 		if err := writeConfigFile(); err != nil {
 			log.Fatalf("failed to write default config file: %v", err)
 		} else {
-			fmt.Println("writing default config file to: " + defaultConfigFile)
+			log.Println("writing default config file to: " + defaultConfigFile)
 		}
 		defaultConfigWritten = true
 		return false
@@ -553,18 +593,24 @@ func processNoConfigFlags(noConfigStart bool) {
 	}
 	processListenFlag()
 
+	endpointAndTyp := func(endpoint string) (string, string) {
+		typ := ctrld.ResolverTypeFromEndpoint(endpoint)
+		return strings.TrimPrefix(endpoint, "quic://"), typ
+	}
+	pEndpoint, pType := endpointAndTyp(primaryUpstream)
 	upstream := map[string]*ctrld.UpstreamConfig{
 		"0": {
-			Name:     primaryUpstream,
-			Endpoint: primaryUpstream,
-			Type:     ctrld.ResolverTypeDOH,
+			Name:     pEndpoint,
+			Endpoint: pEndpoint,
+			Type:     pType,
 		},
 	}
 	if secondaryUpstream != "" {
+		sEndpoint, sType := endpointAndTyp(secondaryUpstream)
 		upstream["1"] = &ctrld.UpstreamConfig{
-			Name:     secondaryUpstream,
-			Endpoint: secondaryUpstream,
-			Type:     ctrld.ResolverTypeLegacy,
+			Name:     sEndpoint,
+			Endpoint: sEndpoint,
+			Type:     sType,
 		}
 		rules := make([]ctrld.Rule, 0, len(domains))
 		for _, domain := range domains {
@@ -721,8 +767,26 @@ func selfCheckStatus(status service.Status) service.Status {
 	err := errors.New("query failed")
 	maxAttempts := 20
 	mainLog.Debug().Msg("Performing self-check")
+	var (
+		lcChanged map[string]*ctrld.ListenerConfig
+		mu        sync.Mutex
+	)
+	v.OnConfigChange(func(in fsnotify.Event) {
+		mu.Lock()
+		defer mu.Unlock()
+		if err := v.UnmarshalKey("listener", &lcChanged); err != nil {
+			log.Printf("failed to unmarshal listener config: %v", err)
+			return
+		}
+	})
+	v.WatchConfig()
 	for i := 0; i < maxAttempts; i++ {
 		lc := cfg.Listener["0"]
+		mu.Lock()
+		if lcChanged != nil {
+			lc = lcChanged["0"]
+		}
+		mu.Unlock()
 		m := new(dns.Msg)
 		m.SetQuestion(selfCheckFQDN+".", dns.TypeA)
 		m.RecursionDesired = true

cmd/ctrld/dns_proxy.go

@@ -56,7 +56,7 @@ func (p *prog) serveDNS(listenerNum string) error {
 		}
 	})
 
-	g := new(errgroup.Group)
+	g, ctx := errgroup.WithContext(context.Background())
 	for _, proto := range []string{"udp", "tcp"} {
 		proto := proto
 		// On Windows, there's no easy way for disabling/removing IPv6 DNS resolver, so we check whether we can
@@ -68,6 +68,10 @@ func (p *prog) serveDNS(listenerNum string) error {
 					Net:     proto,
 					Handler: handler,
 				}
+				go func() {
+					<-ctx.Done()
+					_ = s.Shutdown()
+				}()
 				if err := s.ListenAndServe(); err != nil {
 					mainLog.Error().Err(err).Msg("could not serving on ::1")
 				}
@@ -80,6 +84,10 @@ func (p *prog) serveDNS(listenerNum string) error {
 				Net:     proto,
 				Handler: handler,
 			}
+			go func() {
+				<-ctx.Done()
+				_ = s.Shutdown()
+			}()
 			if err := s.ListenAndServe(); err != nil {
 				mainLog.Error().Err(err).Msgf("could not listen and serve on: %s", s.Addr)
 				return err

cmd/ctrld/main.go

@@ -73,7 +73,6 @@ func initLogging() {
 		}
 		writers = append(writers, logFile)
 	}
-	zerolog.TimeFieldFormat = zerolog.TimeFormatUnixMs
 	consoleWriter := zerolog.NewConsoleWriter(func(w *zerolog.ConsoleWriter) {
 		w.TimeFormat = time.StampMilli
 	})

cmd/ctrld/prog.go

@@ -28,6 +28,10 @@ var svcConfig = &service.Config{
 }
 
 type prog struct {
+	mu     sync.Mutex
+	waitCh chan struct{}
+	stopCh chan struct{}
+
 	cfg   *ctrld.Config
 	cache dnscache.Cacher
 }
@@ -39,6 +43,8 @@ func (p *prog) Start(s service.Service) error {
 }
 
 func (p *prog) run() {
+	// Wait the caller to signal that we can do our logic.
+	<-p.waitCh
 	p.preRun()
 	if p.cfg.Service.CacheEnable {
 		cacher, err := dnscache.NewLRUCache(p.cfg.Service.CacheSize)
@@ -106,7 +112,9 @@ func (p *prog) run() {
 					} else {
 						mainLog.Info().Msg("writing config file to: " + defaultConfigFile)
 					}
+					p.mu.Lock()
 					p.cfg.Service.AllocateIP = true
+					p.mu.Unlock()
 					p.preRun()
 					mainLog.Info().Msgf("Starting DNS server on listener.%s: %s", listenerNum, net.JoinHostPort(ip, strconv.Itoa(port)))
 					if err := p.serveDNS(listenerNum); err != nil {
@@ -128,10 +136,13 @@ func (p *prog) Stop(s service.Service) error {
 		return err
 	}
 	mainLog.Info().Msg("Service stopped")
+	close(p.stopCh)
 	return nil
 }
 
 func (p *prog) allocateIP(ip string) error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
 	if !p.cfg.Service.AllocateIP {
 		return nil
 	}
@@ -139,6 +150,8 @@ func (p *prog) allocateIP(ip string) error {
 }
 
 func (p *prog) deAllocateIP() error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
 	if !p.cfg.Service.AllocateIP {
 		return nil
 	}

config.go

@@ -155,6 +155,12 @@ func (uc *UpstreamConfig) Init() {
 // SetupBootstrapIP manually find all available IPs of the upstream.
 // The first usable IP will be used as bootstrap IP of the upstream.
 func (uc *UpstreamConfig) SetupBootstrapIP() {
+	uc.setupBootstrapIP(true)
+}
+
+// SetupBootstrapIP manually find all available IPs of the upstream.
+// The first usable IP will be used as bootstrap IP of the upstream.
+func (uc *UpstreamConfig) setupBootstrapIP(withBootstrapDNS bool) {
 	bootstrapIP := func(record dns.RR) string {
 		switch ar := record.(type) {
 		case *dns.A:
@@ -166,7 +172,9 @@ func (uc *UpstreamConfig) SetupBootstrapIP() {
 	}
 
 	resolver := &osResolver{nameservers: availableNameservers()}
-	resolver.nameservers = append([]string{net.JoinHostPort(bootstrapDNS, "53")}, resolver.nameservers...)
+	if withBootstrapDNS {
+		resolver.nameservers = append([]string{net.JoinHostPort(bootstrapDNS, "53")}, resolver.nameservers...)
+	}
 	ProxyLog.Debug().Msgf("Resolving %q using bootstrap DNS %q", uc.Domain, resolver.nameservers)
 	timeoutMs := 2000
 	if uc.Timeout > 0 && uc.Timeout < timeoutMs {
@@ -185,7 +193,7 @@ func (uc *UpstreamConfig) SetupBootstrapIP() {
 			return
 		}
 		if r.Rcode != dns.RcodeSuccess {
-			ProxyLog.Error().Msgf("could not resolve domain return code: %d, upstream", r.Rcode)
+			ProxyLog.Error().Msgf("could not resolve domain %q, return code: %s", uc.Domain, dns.RcodeToString[r.Rcode])
 			return
 		}
 		if len(r.Answer) == 0 {
@@ -228,9 +236,13 @@ func (uc *UpstreamConfig) ReBootstrap() {
 	default:
 		return
 	}
-	_, _, _ = uc.g.Do("rebootstrap", func() (any, error) {
+	_, _, _ = uc.g.Do("ReBootstrap", func() (any, error) {
 		ProxyLog.Debug().Msg("re-bootstrapping upstream ip")
 		n := uint32(len(uc.bootstrapIPs))
+		if n == 0 {
+			uc.SetupBootstrapIP()
+			uc.setupTransportWithoutPingUpstream()
+		}
 
 		timeoutMs := 1000
 		if uc.Timeout > 0 && uc.Timeout < timeoutMs {
@@ -368,3 +380,27 @@ func availableNameservers() []string {
 	}
 	return nss[:n]
 }
+
+// ResolverTypeFromEndpoint tries guessing the resolver type with a given endpoint
+// using following rules:
+//
+// - If endpoint is an IP address ->  ResolverTypeLegacy
+// - If endpoint starts with "https://" -> ResolverTypeDOH
+// - If endpoint starts with "quic://" -> ResolverTypeDOQ
+// - For anything else -> ResolverTypeDOT
+func ResolverTypeFromEndpoint(endpoint string) string {
+	switch {
+	case strings.HasPrefix(endpoint, "https://"):
+		return ResolverTypeDOH
+	case strings.HasPrefix(endpoint, "quic://"):
+		return ResolverTypeDOQ
+	}
+	host := endpoint
+	if strings.Contains(endpoint, ":") {
+		host, _, _ = net.SplitHostPort(host)
+	}
+	if ip := net.ParseIP(host); ip != nil {
+		return ResolverTypeLegacy
+	}
+	return ResolverTypeDOT
+}

config_internal_test.go

@@ -0,0 +1,21 @@
+package ctrld
+
+import (
+	"testing"
+)
+
+func TestUpstreamConfig_SetupBootstrapIP(t *testing.T) {
+	uc := &UpstreamConfig{
+		Name:     "test",
+		Type:     ResolverTypeDOH,
+		Endpoint: "https://freedns.controld.com/p2",
+		Timeout:  5000,
+	}
+	uc.Init()
+	uc.setupBootstrapIP(false)
+	if uc.BootstrapIP == "" {
+		t.Log(availableNameservers())
+		t.Fatal("could not bootstrap ip without bootstrap DNS")
+	}
+	t.Log(uc)
+}

go.mod

@@ -1,16 +1,18 @@
 module github.com/Control-D-Inc/ctrld
 
-go 1.19
+go 1.20
 
 require (
 	github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534
+	github.com/cuonglm/osinfo v0.0.0-20230329055532-c513f836da19
 	github.com/frankban/quicktest v1.14.3
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/go-playground/validator/v10 v10.11.1
 	github.com/godbus/dbus/v5 v5.0.6
 	github.com/hashicorp/golang-lru/v2 v2.0.1
 	github.com/illarion/gonotify v1.0.1
-	github.com/insomniacslk/dhcp v0.0.0-20211209223715-7d93572ebe8e
+	github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8
+	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86
 	github.com/kardianos/service v1.2.1
 	github.com/miekg/dns v1.1.50
 	github.com/pelletier/go-toml/v2 v2.0.6
@@ -19,10 +21,11 @@ require (
 	github.com/spf13/cobra v1.4.0
 	github.com/spf13/viper v1.14.0
 	github.com/stretchr/testify v1.8.1
+	golang.org/x/net v0.7.0
 	golang.org/x/sync v0.1.0
 	golang.org/x/sys v0.5.0
 	golang.zx2c4.com/wireguard/windows v0.5.3
-	tailscale.com v1.34.1
+	tailscale.com v1.38.3
 )
 
 require (
@@ -36,7 +39,6 @@ require (
 	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
-	github.com/josharian/native v1.0.0 // indirect
 	github.com/jsimonetti/rtnetlink v1.1.2-0.20220408201609-d380b505068b // indirect
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/kr/text v0.2.0 // indirect
@@ -45,9 +47,9 @@ require (
 	github.com/mattn/go-colorable v0.1.12 // indirect
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7 // indirect
-	github.com/mdlayher/netlink v1.6.0 // indirect
+	github.com/mdlayher/netlink v1.7.1 // indirect
 	github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065 // indirect
-	github.com/mdlayher/socket v0.2.3 // indirect
+	github.com/mdlayher/socket v0.4.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/onsi/ginkgo/v2 v2.2.0 // indirect
 	github.com/pelletier/go-toml v1.9.5 // indirect
@@ -62,14 +64,13 @@ require (
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/subosito/gotenv v1.4.1 // indirect
-	github.com/u-root/uio v0.0.0-20220204230159-dac05f7d2cb4 // indirect
+	github.com/u-root/uio v0.0.0-20221213070652-c3537552635f // indirect
 	go4.org/mem v0.0.0-20210711025021-927187094b94 // indirect
-	golang.org/x/crypto v0.4.0 // indirect
+	golang.org/x/crypto v0.6.0 // indirect
 	golang.org/x/exp v0.0.0-20221205204356-47842c84f3db // indirect
-	golang.org/x/mod v0.6.0 // indirect
-	golang.org/x/net v0.7.0 // indirect
+	golang.org/x/mod v0.7.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
-	golang.org/x/tools v0.2.0 // indirect
+	golang.org/x/tools v0.4.1-0.20221208213631-3f74d914ae6d // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -54,6 +54,8 @@ github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534 h1:rtAn27
 github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/cuonglm/osinfo v0.0.0-20230329055532-c513f836da19 h1:7P/f19Mr0oa3ug8BYt4JuRe/Zq3dF4Mrr4m8+Kw+Hcs=
+github.com/cuonglm/osinfo v0.0.0-20230329055532-c513f836da19/go.mod h1:G45410zMgmnSjLVKCq4f6GpbYAzoP2plX9rPwgx6C24=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -163,10 +165,12 @@ github.com/illarion/gonotify v1.0.1 h1:F1d+0Fgbq/sDWjj/r66ekjDG+IDeecQKUFH4wNwso
 github.com/illarion/gonotify v1.0.1/go.mod h1:zt5pmDofZpU1f8aqlK0+95eQhoEAn/d4G4B/FjVW4jE=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
-github.com/insomniacslk/dhcp v0.0.0-20211209223715-7d93572ebe8e h1:IQpunlq7T+NiJJMO7ODYV2YWBiv/KnObR3gofX0mWOo=
-github.com/insomniacslk/dhcp v0.0.0-20211209223715-7d93572ebe8e/go.mod h1:h+MxyHxRg9NH3terB1nfRIUaQEcI0XOVkdR9LNBlp8E=
-github.com/josharian/native v1.0.0 h1:Ts/E8zCSEsG17dUqv7joXJFybuMLjQfWE04tsBODTxk=
+github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8 h1:Z72DOke2yOK0Ms4Z2LK1E1OrRJXOxSj5DllTz2FYTRg=
+github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8/go.mod h1:m5WMe03WCvWcXjRnhvaAbAAXdCnu20J5P+mmH44ZzpE=
 github.com/josharian/native v1.0.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
+github.com/josharian/native v1.0.1-0.20221213033349-c1e37c09b531/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
+github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86 h1:elKwZS1OcdQ0WwEDBeqxKwb7WB62QX8bvZ/FJnVXIfk=
+github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86/go.mod h1:aFAMtuldEgx/4q7iSGazk22+IcgvtiC+HIimFO9XlS8=
 github.com/jsimonetti/rtnetlink v0.0.0-20190606172950-9527aa82566a/go.mod h1:Oz+70psSo5OFh8DBl0Zv2ACw7Esh6pPUphlvZG9x7uw=
 github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4/go.mod h1:WGuG/smIU4J/54PblvSbh+xvCZmpJnFgr3ds6Z55XMQ=
 github.com/jsimonetti/rtnetlink v0.0.0-20201009170750-9c6f07d100c1/go.mod h1:hqoO/u39cqLeBLebZ8fWdE96O7FxrAsRYhnVOdgHxok=
@@ -202,14 +206,15 @@ github.com/mdlayher/netlink v0.0.0-20190409211403-11939a169225/go.mod h1:eQB3mZE
 github.com/mdlayher/netlink v1.0.0/go.mod h1:KxeJAFOFLG6AjpyDkQ/iIhxygIUKD+vcwqcnu43w/+M=
 github.com/mdlayher/netlink v1.1.0/go.mod h1:H4WCitaheIsdF9yOYu8CFmCgQthAPIWZmcKp9uZHgmY=
 github.com/mdlayher/netlink v1.1.1/go.mod h1:WTYpFb/WTvlRJAyKhZL5/uy69TDDpHHu2VZmb2XgV7o=
-github.com/mdlayher/netlink v1.6.0 h1:rOHX5yl7qnlpiVkFWoqccueppMtXzeziFjWAjLg6sz0=
 github.com/mdlayher/netlink v1.6.0/go.mod h1:0o3PlBmGst1xve7wQ7j/hwpNaFaH4qCRyWCdcZk8/vA=
+github.com/mdlayher/netlink v1.7.1 h1:FdUaT/e33HjEXagwELR8R3/KL1Fq5x3G5jgHLp/BTmg=
+github.com/mdlayher/netlink v1.7.1/go.mod h1:nKO5CSjE/DJjVhk/TNp6vCE1ktVxEA8VEh8drhZzxsQ=
 github.com/mdlayher/raw v0.0.0-20190606142536-fef19f00fc18/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
 github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065 h1:aFkJ6lx4FPip+S+Uw4aTegFMct9shDvP+79PsSxpm3w=
 github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
 github.com/mdlayher/socket v0.1.1/go.mod h1:mYV5YIZAfHh4dzDVzI8x8tWLWCliuX8Mon5Awbj+qDs=
-github.com/mdlayher/socket v0.2.3 h1:XZA2X2TjdOwNoNPVPclRCURoX/hokBY8nkTmRZFEheM=
-github.com/mdlayher/socket v0.2.3/go.mod h1:bz12/FozYNH/VbvC3q7TRIK/Y6dH1kCKsXaUeXi/FmY=
+github.com/mdlayher/socket v0.4.0 h1:280wsy40IC9M9q1uPGcLBwXpcTQDtoGwVt+BNoITxIw=
+github.com/mdlayher/socket v0.4.0/go.mod h1:xxFqz5GRCUN3UEOm9CZqEJsAbe1C8OwSK46NlmWuVoc=
 github.com/miekg/dns v1.1.50 h1:DQUfb9uc6smULcREF09Uc+/Gd46YWqJd5DbpPE9xkcA=
 github.com/miekg/dns v1.1.50/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
@@ -275,9 +280,8 @@ github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKs
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/subosito/gotenv v1.4.1 h1:jyEFiXpy21Wm81FBN71l9VoMMV8H8jG+qIK3GCpY6Qs=
 github.com/subosito/gotenv v1.4.1/go.mod h1:ayKnFf/c6rvx/2iiLrJUk1e6plDbT3edrFNGqEflhK0=
-github.com/u-root/uio v0.0.0-20210528114334-82958018845c/go.mod h1:LpEX5FO/cB+WF4TYGY1V5qktpaZLkKkSegbr0V4eYXA=
-github.com/u-root/uio v0.0.0-20220204230159-dac05f7d2cb4 h1:hl6sK6aFgTLISijk6xIzeqnPzQcsLqqvL6vEfTPinME=
-github.com/u-root/uio v0.0.0-20220204230159-dac05f7d2cb4/go.mod h1:LpEX5FO/cB+WF4TYGY1V5qktpaZLkKkSegbr0V4eYXA=
+github.com/u-root/uio v0.0.0-20221213070652-c3537552635f h1:dpx1PHxYqAnXzbryJrWP1NQLzEjwcVgFLhkknuFQ7ww=
+github.com/u-root/uio v0.0.0-20221213070652-c3537552635f/go.mod h1:IogEAUBXDEwX7oR/BMmCctShYs80ql4hF0ySdzGxf7E=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -299,8 +303,8 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20211108221036-ceb1ce70b4fa/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20211215153901-e495a2d5b3d3/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
-golang.org/x/crypto v0.4.0 h1:UVQgzMY87xqpKNgb+kDsll2Igd33HszWHFLmpaRMq/8=
-golang.org/x/crypto v0.4.0/go.mod h1:3quD/ATkf6oY+rnes5c3ExXTbLc8mueNue5/DoinL80=
+golang.org/x/crypto v0.6.0 h1:qfktjS5LUO+fFKeJXZ+ikTRijMmljikvG68fpMMruSc=
+golang.org/x/crypto v0.6.0/go.mod h1:OFC/31mSvZgRz0V1QTNCzfAI1aIRzbiufJtkMIlEp58=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -337,8 +341,8 @@ 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 v0.6.0 h1:b9gGHsz9/HhJ3HF5DHQytPpuwocVTChQJK3AvoLRD5I=
-golang.org/x/mod v0.6.0/go.mod h1:4mET923SAdbXp2ki8ey+zGs1SLqsuM2Y0uvdZR/fUNI=
+golang.org/x/mod v0.7.0 h1:LapD9S96VoQRhi/GrNTqeBJFrUjs5UHCAtTlgwA5oZA=
+golang.org/x/mod v0.7.0/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=
@@ -448,7 +452,6 @@ golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7w
 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 v0.0.0-20210525143221-35b2ab0089ea/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=
@@ -456,7 +459,9 @@ golang.org/x/sys v0.0.0-20210906170528-6f6e22806c34/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220128215802-99c3d69c2c27/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220622161953-175b2fd9d664/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.4.1-0.20230131160137-e7d7f63158de/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -524,8 +529,8 @@ golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e/go.mod h1:emZCQorbCU4vsT4f
 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 v0.1.6-0.20210726203631-07bc1bf47fb2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
-golang.org/x/tools v0.2.0 h1:G6AHpWxTMGY1KyEYoAQ5WTtIekUUvDNjan3ugu60JvE=
-golang.org/x/tools v0.2.0/go.mod h1:y4OqIKeOV/fWJetJ8bXPU1sEVniLMIyDAZWeHdV+NTA=
+golang.org/x/tools v0.4.1-0.20221208213631-3f74d914ae6d h1:9ZNWAi4CYhNv60mXGgAncgq7SGc5qa7C8VZV8Tg7Ggs=
+golang.org/x/tools v0.4.1-0.20221208213631-3f74d914ae6d/go.mod h1:UE5sM2OK9E/d67R0ANs2xJizIymRP5gJU295PvKXxjQ=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -645,5 +650,5 @@ honnef.co/go/tools v0.0.1-2020.1.4/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=
 rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
-tailscale.com v1.34.1 h1:tqm9Ww4ltyYp3IPe7vCGch6tT6j5G/WXPQ6BrVZ6pdI=
-tailscale.com v1.34.1/go.mod h1:ZsBP7rjzzB2rp+UCOumr9DAe0EQ6OPivwSXcz/BrekQ=
+tailscale.com v1.38.3 h1:2aX3+u0Re8QcN6nq7zf9Aa4ZCR2Nf6Imv3isqdQrb58=
+tailscale.com v1.38.3/go.mod h1:UWLQxcd8dz+lds2I+HpfXSruHrvXM1j4zd4zdx86t7w=

internal/controld/config.go

@@ -7,16 +7,26 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"sync"
 	"time"
 
+	"github.com/miekg/dns"
+
+	"github.com/Control-D-Inc/ctrld"
 	ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
 )
 
 const (
+	apiDomain         = "api.controld.com"
 	resolverDataURL   = "https://api.controld.com/utility"
 	InvalidConfigCode = 40401
 )
 
+var (
+	resolveAPIDomainOnce sync.Once
+	apiDomainIP          string
+)
+
 // ResolverConfig represents Control D resolver data.
 type ResolverConfig struct {
 	DOH     string   `json:"doh"`
@@ -64,6 +74,44 @@ func FetchResolverConfig(uid string) (*ResolverConfig, error) {
 		if ctrldnet.SupportsIPv4() {
 			proto = "tcp4"
 		}
+		resolveAPIDomainOnce.Do(func() {
+			r, err := ctrld.NewResolver(&ctrld.UpstreamConfig{Type: ctrld.ResolverTypeOS})
+			if err != nil {
+				return
+			}
+			ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+			defer cancel()
+
+			msg := new(dns.Msg)
+			dnsType := dns.TypeAAAA
+			if proto == "tcp4" {
+				dnsType = dns.TypeA
+			}
+			msg.SetQuestion(apiDomain+".", dnsType)
+			msg.RecursionDesired = true
+			answer, err := r.Resolve(ctx, msg)
+			if err != nil {
+				return
+			}
+			if answer.Rcode != dns.RcodeSuccess || len(answer.Answer) == 0 {
+				return
+			}
+			for _, record := range answer.Answer {
+				switch ar := record.(type) {
+				case *dns.A:
+					apiDomainIP = ar.A.String()
+					return
+				case *dns.AAAA:
+					apiDomainIP = ar.AAAA.String()
+					return
+				}
+			}
+		})
+		if apiDomainIP != "" {
+			if _, port, _ := net.SplitHostPort(addr); port != "" {
+				return ctrldnet.Dialer.DialContext(ctx, proto, net.JoinHostPort(apiDomainIP, port))
+			}
+		}
 		return ctrldnet.Dialer.DialContext(ctx, proto, addr)
 	}
 	client := http.Client{

internal/dns/nm.go

@@ -14,8 +14,8 @@ import (
 	"time"
 
 	"github.com/godbus/dbus/v5"
+	"github.com/josharian/native"
 	"tailscale.com/util/dnsname"
-	"tailscale.com/util/endian"
 )
 
 const (
@@ -131,7 +131,7 @@ func (m *nmManager) trySet(ctx context.Context, config OSConfig) error {
 	for _, ip := range config.Nameservers {
 		b := ip.As16()
 		if ip.Is4() {
-			dnsv4 = append(dnsv4, endian.Native.Uint32(b[12:]))
+			dnsv4 = append(dnsv4, native.Endian.Uint32(b[12:]))
 		} else {
 			dnsv6 = append(dnsv6, b[:])
 		}

internal/dns/resolvconffile/resolvconffile.go

@@ -15,7 +15,6 @@ import (
 	"strings"
 
 	"tailscale.com/util/dnsname"
-	"tailscale.com/util/strs"
 )
 
 // Path is the canonical location of resolv.conf.
@@ -63,7 +62,7 @@ func Parse(r io.Reader) (*Config, error) {
 		line, _, _ = strings.Cut(line, "#") // remove any comments
 		line = strings.TrimSpace(line)
 
-		if s, ok := strs.CutPrefix(line, "nameserver"); ok {
+		if s, ok := strings.CutPrefix(line, "nameserver"); ok {
 			nameserver := strings.TrimSpace(s)
 			if len(nameserver) == len(s) {
 				return nil, fmt.Errorf("missing space after \"nameserver\" in %q", line)
@@ -76,7 +75,7 @@ func Parse(r io.Reader) (*Config, error) {
 			continue
 		}
 
-		if s, ok := strs.CutPrefix(line, "search"); ok {
+		if s, ok := strings.CutPrefix(line, "search"); ok {
 			domains := strings.TrimSpace(s)
 			if len(domains) == len(s) {
 				// No leading space?!

internal/net/net.go

@@ -66,7 +66,7 @@ func supportListenIPv6Local() bool {
 }
 
 func probeStack() {
-	b := backoff.NewBackoff("probeStack", func(format string, args ...any) {}, time.Minute)
+	b := backoff.NewBackoff("probeStack", func(format string, args ...any) {}, 5*time.Second)
 	for {
 		if _, err := probeStackDialer.Dial("udp", bootstrapDNS); err == nil {
 			hasNetworkUp = true

nameservers.go

@@ -0,0 +1,29 @@
+package ctrld
+
+import "net"
+
+type dnsFn func() []string
+
+func nameservers() []string {
+	var dns []string
+	seen := make(map[string]bool)
+	ch := make(chan []string)
+	fns := dnsFns()
+
+	for _, fn := range fns {
+		go func(fn dnsFn) {
+			ch <- fn()
+		}(fn)
+	}
+	for range fns {
+		for _, ns := range <-ch {
+			if seen[ns] {
+				continue
+			}
+			seen[ns] = true
+			dns = append(dns, net.JoinHostPort(ns, "53"))
+		}
+	}
+
+	return dns
+}

nameservers_bsd.go

@@ -0,0 +1,75 @@
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
+
+package ctrld
+
+import (
+	"net"
+	"os/exec"
+	"runtime"
+	"strings"
+	"syscall"
+
+	"golang.org/x/net/route"
+)
+
+func dnsFns() []dnsFn {
+	return []dnsFn{dnsFromRIB, dnsFromIPConfig}
+}
+
+func dnsFromRIB() []string {
+	var dns []string
+	rib, err := route.FetchRIB(syscall.AF_UNSPEC, route.RIBTypeRoute, 0)
+	if err != nil {
+		return nil
+	}
+	messages, err := route.ParseRIB(route.RIBTypeRoute, rib)
+	if err != nil {
+		return nil
+	}
+	for _, message := range messages {
+		message, ok := message.(*route.RouteMessage)
+		if !ok {
+			continue
+		}
+		addresses := message.Addrs
+		if len(addresses) < 2 {
+			continue
+		}
+		dst, gw := toNetIP(addresses[0]), toNetIP(addresses[1])
+		if dst == nil || gw == nil {
+			continue
+		}
+		if gw.IsLoopback() {
+			continue
+		}
+		if dst.Equal(net.IPv4zero) || dst.Equal(net.IPv6zero) {
+			dns = append(dns, gw.String())
+		}
+	}
+	return dns
+}
+
+func dnsFromIPConfig() []string {
+	if runtime.GOOS != "darwin" {
+		return nil
+	}
+	cmd := exec.Command("ipconfig", "getoption", "", "domain_name_server")
+	out, _ := cmd.Output()
+	if ip := net.ParseIP(strings.TrimSpace(string(out))); ip != nil {
+		return []string{ip.String()}
+	}
+	return nil
+}
+
+func toNetIP(addr route.Addr) net.IP {
+	switch t := addr.(type) {
+	case *route.Inet4Addr:
+		return net.IPv4(t.IP[0], t.IP[1], t.IP[2], t.IP[3])
+	case *route.Inet6Addr:
+		ip := make(net.IP, net.IPv6len)
+		copy(ip, t.IP[:])
+		return ip
+	default:
+		return nil
+	}
+}

nameservers_linux.go

@@ -0,0 +1,97 @@
+package ctrld
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/hex"
+	"net"
+	"os"
+
+	"github.com/Control-D-Inc/ctrld/internal/dns/resolvconffile"
+)
+
+const (
+	v4RouteFile = "/proc/net/route"
+	v6RouteFile = "/proc/net/ipv6_route"
+)
+
+func dnsFns() []dnsFn {
+	return []dnsFn{dns4, dns6, dnsFromSystemdResolver}
+}
+
+func dns4() []string {
+	f, err := os.Open(v4RouteFile)
+	if err != nil {
+		return nil
+	}
+	defer f.Close()
+
+	var dns []string
+	seen := make(map[string]bool)
+	s := bufio.NewScanner(f)
+	first := true
+	for s.Scan() {
+		if first {
+			first = false
+			continue
+		}
+		fields := bytes.Fields(s.Bytes())
+		if len(fields) < 2 {
+			continue
+		}
+
+		gw := make([]byte, net.IPv4len)
+		// Third fields is gateway.
+		if _, err := hex.Decode(gw, fields[2]); err != nil {
+			continue
+		}
+		ip := net.IPv4(gw[3], gw[2], gw[1], gw[0])
+		if ip.Equal(net.IPv4zero) || seen[ip.String()] {
+			continue
+		}
+		seen[ip.String()] = true
+		dns = append(dns, ip.String())
+	}
+	return dns
+}
+
+func dns6() []string {
+	f, err := os.Open(v6RouteFile)
+	if err != nil {
+		return nil
+	}
+	defer f.Close()
+
+	var dns []string
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		fields := bytes.Fields(s.Bytes())
+		if len(fields) < 4 {
+			continue
+		}
+
+		gw := make([]byte, net.IPv6len)
+		// Fifth fields is gateway.
+		if _, err := hex.Decode(gw, fields[4]); err != nil {
+			continue
+		}
+		ip := net.IP(gw)
+		if ip.Equal(net.IPv6zero) {
+			continue
+		}
+		dns = append(dns, ip.String())
+	}
+	return dns
+}
+
+func dnsFromSystemdResolver() []string {
+	c, err := resolvconffile.ParseFile("/run/systemd/resolve/resolv.conf")
+	if err != nil {
+		return nil
+	}
+	ns := make([]string, 0, len(c.Nameservers))
+	for _, nameserver := range c.Nameservers {
+		ns = append(ns, nameserver.String())
+	}
+	return ns
+}

nameservers_test.go

@@ -0,0 +1,11 @@
+package ctrld
+
+import "testing"
+
+func TestNameservers(t *testing.T) {
+	ns := nameservers()
+	if len(ns) == 0 {
+		t.Fatal("failed to get nameservers")
+	}
+	t.Log(ns)
+}

nameservers_unix.go

@@ -1,11 +0,0 @@
-//go:build !js && !windows
-
-package ctrld
-
-import (
-	"github.com/Control-D-Inc/ctrld/internal/resolvconffile"
-)
-
-func nameservers() []string {
-	return resolvconffile.NameServersWithPort()
-}

nameservers_windows.go

@@ -2,70 +2,59 @@ package ctrld
 
 import (
 	"net"
-	"os"
 	"syscall"
-	"unsafe"
+
+	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 
 	"golang.org/x/sys/windows"
 )
 
-func nameservers() []string {
-	aas, err := adapterAddresses()
+func dnsFns() []dnsFn {
+	return []dnsFn{dnsFromAdapter}
+}
+
+func dnsFromAdapter() []string {
+	aas, err := winipcfg.GetAdaptersAddresses(syscall.AF_UNSPEC, winipcfg.GAAFlagIncludeGateways|winipcfg.GAAFlagIncludePrefix)
 	if err != nil {
 		return nil
 	}
-	ns := make([]string, 0, len(aas))
+	ns := make([]string, 0, len(aas)*2)
+	seen := make(map[string]bool)
+	do := func(addr windows.SocketAddress) {
+		sa, err := addr.Sockaddr.Sockaddr()
+		if err != nil {
+			return
+		}
+		var ip net.IP
+		switch sa := sa.(type) {
+		case *syscall.SockaddrInet4:
+			ip = net.IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])
+		case *syscall.SockaddrInet6:
+			ip = make(net.IP, net.IPv6len)
+			copy(ip, sa.Addr[:])
+			if ip[0] == 0xfe && ip[1] == 0xc0 {
+				// Ignore these fec0/10 ones. Windows seems to
+				// populate them as defaults on its misc rando
+				// interfaces.
+				return
+			}
+		default:
+			return
+
+		}
+		if ip.IsLoopback() || seen[ip.String()] {
+			return
+		}
+		seen[ip.String()] = true
+		ns = append(ns, ip.String())
+	}
 	for _, aa := range aas {
-		for dns := aa.FirstDnsServerAddress; dns != nil; dns = dns.Next {
-			sa, err := dns.Address.Sockaddr.Sockaddr()
-			if err != nil {
-				continue
-			}
-			var ip net.IP
-			switch sa := sa.(type) {
-			case *syscall.SockaddrInet4:
-				ip = net.IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])
-			case *syscall.SockaddrInet6:
-				ip = make(net.IP, net.IPv6len)
-				copy(ip, sa.Addr[:])
-				if ip[0] == 0xfe && ip[1] == 0xc0 {
-					// Ignore these fec0/10 ones. Windows seems to
-					// populate them as defaults on its misc rando
-					// interfaces.
-					continue
-				}
-			default:
-				// Unexpected type.
-				continue
-			}
-			ns = append(ns, net.JoinHostPort(ip.String(), "53"))
+		for dns := aa.FirstDNSServerAddress; dns != nil; dns = dns.Next {
+			do(dns.Address)
+		}
+		for gw := aa.FirstGatewayAddress; gw != nil; gw = gw.Next {
+			do(gw.Address)
 		}
 	}
 	return ns
 }
-
-func adapterAddresses() ([]*windows.IpAdapterAddresses, error) {
-	var b []byte
-	l := uint32(15000) // recommended initial size
-	for {
-		b = make([]byte, l)
-		err := windows.GetAdaptersAddresses(syscall.AF_UNSPEC, windows.GAA_FLAG_INCLUDE_PREFIX, 0, (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])), &l)
-		if err == nil {
-			if l == 0 {
-				return nil, nil
-			}
-			break
-		}
-		if err.(syscall.Errno) != syscall.ERROR_BUFFER_OVERFLOW {
-			return nil, os.NewSyscallError("getadaptersaddresses", err)
-		}
-		if l <= uint32(len(b)) {
-			return nil, os.NewSyscallError("getadaptersaddresses", err)
-		}
-	}
-	var aas []*windows.IpAdapterAddresses
-	for aa := (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])); aa != nil; aa = aa.Next {
-		aas = append(aas, aa)
-	}
-	return aas, nil
-}

resolver.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"sync"
 
 	"github.com/miekg/dns"
 )
@@ -69,8 +70,15 @@ func (o *osResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, error
 
 	dnsClient := &dns.Client{Net: "udp"}
 	ch := make(chan *osResolverResult, numServers)
+	var wg sync.WaitGroup
+	wg.Add(len(o.nameservers))
+	go func() {
+		wg.Wait()
+		close(ch)
+	}()
 	for _, server := range o.nameservers {
 		go func(server string) {
+			defer wg.Done()
 			answer, _, err := dnsClient.ExchangeContext(ctx, msg, server)
 			ch <- &osResolverResult{answer: answer, err: err}
 		}(server)

resolver_test.go

@@ -0,0 +1,53 @@
+package ctrld
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/miekg/dns"
+)
+
+func Test_osResolver_Resolve(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go func() {
+		defer cancel()
+		resolver := &osResolver{nameservers: []string{"127.0.0.127:5353"}}
+		m := new(dns.Msg)
+		m.SetQuestion("controld.com.", dns.TypeA)
+		m.RecursionDesired = true
+		_, _ = resolver.Resolve(context.Background(), m)
+	}()
+
+	select {
+	case <-time.After(10 * time.Second):
+		t.Error("os resolver hangs")
+	case <-ctx.Done():
+	}
+}
+
+func Test_upstreamTypeFromEndpoint(t *testing.T) {
+	tests := []struct {
+		name         string
+		endpoint     string
+		resolverType string
+	}{
+		{"doh", "https://freedns.controld.com/p2", ResolverTypeDOH},
+		{"doq", "quic://p2.freedns.controld.com", ResolverTypeDOQ},
+		{"dot", "p2.freedns.controld.com", ResolverTypeDOT},
+		{"legacy", "8.8.8.8:53", ResolverTypeLegacy},
+		{"legacy ipv6", "[2404:6800:4005:809::200e]:53", ResolverTypeLegacy},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			if rt := ResolverTypeFromEndpoint(tc.endpoint); rt != tc.resolverType {
+				t.Errorf("mismatch, want: %s, got: %s", tc.resolverType, rt)
+			}
+		})
+	}
+}