all: implement router setup for openwrt

cmd/ctrld/cli.go

@@ -200,7 +200,7 @@ func initCLI() {
 				os.Exit(0)
 			}
 
-			if runtime.GOOS == "linux" && onRouter {
+			if router.Name() != "" {
 				mainLog.Debug().Msg("Router setup")
 				err := router.Configure(&cfg)
 				if errors.Is(err, router.ErrNotSupported) {
@@ -230,8 +230,6 @@ func initCLI() {
 	_ = runCmd.Flags().MarkHidden("homedir")
 	runCmd.Flags().StringVarP(&iface, "iface", "", "", `Update DNS setting for iface, "auto" means the default interface gateway`)
 	_ = runCmd.Flags().MarkHidden("iface")
-	runCmd.Flags().BoolVarP(&onRouter, "router", "", false, `Configure onRouter for running ctrld`)
-	_ = runCmd.Flags().MarkHidden("router")
 
 	rootCmd.AddCommand(runCmd)
 
@@ -249,6 +247,7 @@ func initCLI() {
 			}
 			setDependencies(sc)
 			sc.Arguments = append([]string{"run"}, osArgs...)
+			router.ConfigureService(sc)
 
 			// No config path, generating config in HOME directory.
 			noConfigStart := isNoConfigStart(cmd)
@@ -276,12 +275,12 @@ func initCLI() {
 			cfg.Service.LogPath = logPath
 
 			processCDFlags()
-			// On Windows, the service will be run as SYSTEM, so if ctrld start as Admin,
-			// the user home dir is different, so pass specific arguments that relevant here.
-			if runtime.GOOS == "windows" {
-				if configPath == "" {
-					sc.Arguments = append(sc.Arguments, "--config="+defaultConfigFile)
-				}
+
+			// Explicitly passing config, so on system where home directory could not be obtained,
+			// or sub-process env is different with the parent, we still behave correctly and use
+			// the expected config file.
+			if configPath == "" {
+				sc.Arguments = append(sc.Arguments, "--config="+defaultConfigFile)
 			}
 
 			prog := &prog{}
@@ -297,7 +296,11 @@ func initCLI() {
 				{s.Start, true},
 			}
 			if doTasks(tasks) {
-				status, err := s.Status()
+				if err := router.PostInstall(); err != nil {
+					mainLog.Warn().Err(err).Msg("post installation failed, please check system/service log for details error")
+					return
+				}
+				status, err := serviceStatus(s)
 				if err != nil {
 					mainLog.Warn().Err(err).Msg("could not get service status")
 					return
@@ -329,8 +332,6 @@ func initCLI() {
 	startCmd.Flags().IntVarP(&cacheSize, "cache_size", "", 0, "Enable cache with size items")
 	startCmd.Flags().StringVarP(&cdUID, "cd", "", "", "Control D resolver uid")
 	startCmd.Flags().StringVarP(&iface, "iface", "", "", `Update DNS setting for iface, "auto" means the default interface gateway`)
-	startCmd.Flags().BoolVarP(&onRouter, "router", "", false, `Configure onRouter for running ctrld`)
-	_ = startCmd.Flags().MarkHidden("router")
 
 	stopCmd := &cobra.Command{
 		PreRun: checkHasElevatedPrivilege,
@@ -381,7 +382,7 @@ func initCLI() {
 				stderrMsg(err.Error())
 				return
 			}
-			status, err := s.Status()
+			status, err := serviceStatus(s)
 			if err != nil {
 				stderrMsg(err.Error())
 				os.Exit(1)
@@ -429,6 +430,9 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 					iface = "auto"
 				}
 				prog.resetDNS()
+				if err := router.Cleanup(); err != nil {
+					mainLog.Warn().Err(err).Msg("could not cleanup router")
+				}
 				mainLog.Info().Msg("Service uninstalled")
 				return
 			}
@@ -815,5 +819,5 @@ func selfCheckStatus(status service.Status) service.Status {
 }
 
 func unsupportedPlatformHelp(cmd *cobra.Command) {
-	cmd.PrintErrln("Unsupported or incorrectly chosen onRouter platform. Please open an issue and provide all relevant information: https://github.com/Control-D-Inc/ctrld/issues/new")
+	cmd.PrintErrln("Unsupported or incorrectly chosen router platform. Please open an issue and provide all relevant information: https://github.com/Control-D-Inc/ctrld/issues/new")
 }

cmd/ctrld/cli_router_linux.go

@@ -14,7 +14,7 @@ import (
 func initRouterCLI() {
 	validArgs := append(router.SupportedPlatforms(), "auto")
 	var b strings.Builder
-	b.WriteString("Auto-setup Control D on a onRouter.\n\nSupported platforms:\n\n")
+	b.WriteString("Auto-setup Control D on a router.\n\nSupported platforms:\n\n")
 	for _, arg := range validArgs {
 		b.WriteString("    ₒ ")
 		b.WriteString(arg)
@@ -52,8 +52,7 @@ func initRouterCLI() {
 			}
 
 			cmdArgs := []string{"start"}
-			cmdArgs = append(cmdArgs, os.Args[3:]...)
-			cmdArgs = append(cmdArgs, "--router=true")
+			cmdArgs = append(cmdArgs, osArgs(platform)...)
 			command := exec.Command(exe, cmdArgs...)
 			command.Stdout = os.Stdout
 			command.Stderr = os.Stderr
@@ -63,8 +62,32 @@ func initRouterCLI() {
 			}
 		},
 	}
+	// Keep these flags in sync with startCmd, except for "--router".
+	routerCmd.Flags().StringVarP(&configPath, "config", "c", "", "Path to config file")
+	routerCmd.Flags().StringVarP(&configBase64, "base64_config", "", "", "Base64 encoded config")
+	routerCmd.Flags().StringVarP(&listenAddress, "listen", "", "", "Listener address and port, in format: address:port")
+	routerCmd.Flags().StringVarP(&primaryUpstream, "primary_upstream", "", "", "Primary upstream endpoint")
+	routerCmd.Flags().StringVarP(&secondaryUpstream, "secondary_upstream", "", "", "Secondary upstream endpoint")
+	routerCmd.Flags().StringSliceVarP(&domains, "domains", "", nil, "List of domain to apply in a split DNS policy")
+	routerCmd.Flags().StringVarP(&logPath, "log", "", "", "Path to log file")
+	routerCmd.Flags().IntVarP(&cacheSize, "cache_size", "", 0, "Enable cache with size items")
+	routerCmd.Flags().StringVarP(&cdUID, "cd", "", "", "Control D resolver uid")
+	routerCmd.Flags().StringVarP(&iface, "iface", "", "", `Update DNS setting for iface, "auto" means the default interface gateway`)
+
 	tmpl := routerCmd.UsageTemplate()
 	tmpl = strings.Replace(tmpl, "{{.UseLine}}", "{{.UseLine}} [platform]", 1)
 	routerCmd.SetUsageTemplate(tmpl)
 	rootCmd.AddCommand(routerCmd)
 }
+
+func osArgs(platform string) []string {
+	args := os.Args[2:]
+	n := 0
+	for _, x := range args {
+		if x != platform && x != "auto" {
+			args[n] = x
+			n++
+		}
+	}
+	return args[:n]
+}

cmd/ctrld/dns_proxy.go

@@ -17,10 +17,17 @@ import (
 	"github.com/Control-D-Inc/ctrld"
 	"github.com/Control-D-Inc/ctrld/internal/dnscache"
 	ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
+	"github.com/Control-D-Inc/ctrld/internal/router"
 )
 
 const staleTTL = 60 * time.Second
 
+var osUpstreamConfig = &ctrld.UpstreamConfig{
+	Name:    "OS resolver",
+	Type:    ctrld.ResolverTypeOS,
+	Timeout: 2000,
+}
+
 func (p *prog) serveDNS(listenerNum string) error {
 	listenerConfig := p.cfg.Listener[listenerNum]
 	// make sure ip is allocated
@@ -61,7 +68,7 @@ func (p *prog) serveDNS(listenerNum string) error {
 		proto := proto
 		// On Windows, there's no easy way for disabling/removing IPv6 DNS resolver, so we check whether we can
 		// listen on ::1, then spawn a listener for receiving DNS requests.
-		if runtime.GOOS == "windows" && ctrldnet.SupportsIPv6ListenLocal() {
+		if needLocalIPv6Listener() {
 			g.Go(func() error {
 				s := &dns.Server{
 					Addr:    net.JoinHostPort("::1", strconv.Itoa(listenerConfig.Port)),
@@ -80,7 +87,7 @@ func (p *prog) serveDNS(listenerNum string) error {
 		}
 		g.Go(func() error {
 			s := &dns.Server{
-				Addr:    net.JoinHostPort(listenerConfig.IP, strconv.Itoa(listenerConfig.Port)),
+				Addr:    dnsListenAddress(listenerConfig),
 				Net:     proto,
 				Handler: handler,
 			}
@@ -353,8 +360,13 @@ func ttlFromMsg(msg *dns.Msg) uint32 {
 	return 0
 }
 
-var osUpstreamConfig = &ctrld.UpstreamConfig{
-	Name:    "OS resolver",
-	Type:    ctrld.ResolverTypeOS,
-	Timeout: 2000,
+func needLocalIPv6Listener() bool {
+	return ctrldnet.SupportsIPv6ListenLocal() && runtime.GOOS == "windows"
+}
+
+func dnsListenAddress(lc *ctrld.ListenerConfig) string {
+	if addr := router.ListenAddress(); addr != "" {
+		return addr
+	}
+	return net.JoinHostPort(lc.IP, strconv.Itoa(lc.Port))
 }

cmd/ctrld/main.go

@@ -29,7 +29,6 @@ var (
 	cdUID             string
 	iface             string
 	ifaceStartStop    string
-	onRouter          bool
 
 	mainLog = zerolog.New(io.Discard)
 )

cmd/ctrld/prog.go

@@ -25,6 +25,7 @@ var errWindowsAddrInUse = syscall.Errno(0x2740)
 var svcConfig = &service.Config{
 	Name:        "ctrld",
 	DisplayName: "Control-D Helper Service",
+	Option:      service.KeyValue{},
 }
 
 type prog struct {

cmd/ctrld/service.go

@@ -1,9 +1,12 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"os"
+	"os/exec"
 
+	"github.com/kardianos/service"
 	"github.com/spf13/cobra"
 )
 
@@ -43,3 +46,24 @@ func checkHasElevatedPrivilege(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 }
+
+func serviceStatus(s service.Service) (service.Status, error) {
+	status, err := s.Status()
+	if err != nil && service.Platform() == "unix-systemv" {
+		return unixSystemVServiceStatus()
+	}
+	return status, err
+}
+
+func unixSystemVServiceStatus() (service.Status, error) {
+	out, err := exec.Command("/etc/init.d/ctrld", "status").CombinedOutput()
+	if err != nil {
+		return service.StatusUnknown, nil
+	}
+	switch string(bytes.TrimSpace(out)) {
+	case "running":
+		return service.StatusRunning, nil
+	default:
+		return service.StatusStopped, nil
+	}
+}

internal/router/openwrt.go

@@ -0,0 +1,74 @@
+package router
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+var errUCIEntryNotFound = errors.New("uci: Entry not found")
+
+const openwrtDNSMasqConfigPath = "/tmp/dnsmasq.d/ctrld.conf"
+const openwrtDNSMasqConfigContent = `# GENERATED BY ctrld - DO NOT MODIFY
+port=0
+`
+
+func setupOpenWrt() error {
+	// Delete dnsmasq port if set.
+	if _, err := uci("delete", "dhcp.@dnsmasq[0].port"); err != nil && !errors.Is(err, errUCIEntryNotFound) {
+		return err
+	}
+	// Disable dnsmasq as DNS server.
+	if err := os.WriteFile(openwrtDNSMasqConfigPath, []byte(openwrtDNSMasqConfigContent), 0600); err != nil {
+		return err
+	}
+	// Commit.
+	if _, err := uci("commit"); err != nil {
+		return err
+	}
+	// Restart dnsmasq service.
+	if err := restartDNSMasq(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func cleanupOpenWrt() error {
+	// Remove the custom dnsmasq config
+	if err := os.Remove(openwrtDNSMasqConfigPath); err != nil {
+		return err
+	}
+	// Restart dnsmasq service.
+	if err := restartDNSMasq(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func postInstallOpenWrt() error {
+	return exec.Command("/etc/init.d/ctrld", "enable").Run()
+}
+
+func uci(args ...string) (string, error) {
+	cmd := exec.Command("uci", args...)
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		if strings.HasPrefix(stderr.String(), errUCIEntryNotFound.Error()) {
+			return "", errUCIEntryNotFound
+		}
+		return "", fmt.Errorf("%s:%w", stderr.String(), err)
+	}
+	return strings.TrimSpace(stdout.String()), nil
+}
+
+func restartDNSMasq() error {
+	if out, err := exec.Command("/etc/init.d/dnsmasq", "restart").CombinedOutput(); err != nil {
+		return fmt.Errorf("%s: %w", string(out), err)
+	}
+	return nil
+}

internal/router/procd.go

@@ -0,0 +1,24 @@
+package router
+
+const openWrtScript = `#!/bin/sh /etc/rc.common
+USE_PROCD=1
+# After network starts
+START=21
+# Before network stops
+STOP=89
+cmd="{{.Path}}{{range .Arguments}} {{.|cmd}}{{end}}"
+name="{{.Name}}"
+pid_file="/var/run/${name}.pid"
+
+start_service() {
+    echo "Starting ${name}"
+    procd_open_instance
+    procd_set_param command ${cmd}
+    procd_set_param respawn             # respawn automatically if something died
+    procd_set_param stdout 1            # forward stdout of the command to logd
+    procd_set_param stderr 1            # same for stderr
+    procd_set_param pidfile ${pid_file} # write a pid file on instance start and remove it on stop
+    procd_close_instance
+    echo "${name} has been started"
+}
+`

internal/router/router.go

@@ -8,6 +8,8 @@ import (
 	"os/exec"
 	"sync/atomic"
 
+	"github.com/kardianos/service"
+
 	"github.com/Control-D-Inc/ctrld"
 )
 
@@ -21,7 +23,7 @@ const (
 // ErrNotSupported reports the current router is not supported error.
 var ErrNotSupported = errors.New("unsupported platform")
 
-var routerAtomic atomic.Pointer[router]
+var routerPlatform atomic.Pointer[router]
 
 type router struct {
 	name string
@@ -32,11 +34,13 @@ func SupportedPlatforms() []string {
 	return []string{DDWrt, Merlin, OpenWrt, Ubios}
 }
 
-// Configure change the given *ctrld.Config for running on the router.
+// Configure configures things for running ctrld on the router.
 func Configure(c *ctrld.Config) error {
 	name := Name()
 	switch name {
-	case DDWrt, Merlin, OpenWrt, Ubios:
+	case OpenWrt:
+		return setupOpenWrt()
+	case DDWrt, Merlin, Ubios:
 	default:
 		return ErrNotSupported
 	}
@@ -45,14 +49,57 @@ func Configure(c *ctrld.Config) error {
 	return nil
 }
 
+// ConfigureService performs necessary setup for running ctrld as a service on router.
+func ConfigureService(sc *service.Config) {
+	name := Name()
+	switch name {
+	case OpenWrt:
+		sc.Option["SysvScript"] = openWrtScript
+	case DDWrt, Merlin, Ubios:
+	}
+}
+
+// PostInstall performs task after installing ctrld on router.
+func PostInstall() error {
+	name := Name()
+	switch name {
+	case OpenWrt:
+		return postInstallOpenWrt()
+	case DDWrt, Merlin, Ubios:
+	}
+	return nil
+}
+
+// Cleanup cleans ctrld setup on the router.
+func Cleanup() error {
+	name := Name()
+	switch name {
+	case OpenWrt:
+		return cleanupOpenWrt()
+	case DDWrt, Merlin, Ubios:
+	}
+	return nil
+}
+
+// ListenAddress returns the listener address of ctrld on router.
+func ListenAddress() string {
+	name := Name()
+	switch name {
+	case OpenWrt:
+		return ":53"
+	case DDWrt, Merlin, Ubios:
+	}
+	return ""
+}
+
 // Name returns name of the router platform.
 func Name() string {
-	if r := routerAtomic.Load(); r != nil {
+	if r := routerPlatform.Load(); r != nil {
 		return r.name
 	}
 	r := &router{}
 	r.name = distroName()
-	routerAtomic.Store(r)
+	routerPlatform.Store(r)
 	return r.name
 }