all: add support to Netgear Orbi Voxel

While at it, also ensure checking the service is installed or not before
executing uninstall function, so we won't emit un-necessary errors.

internal/router/dnsmasq/dnsmasq.go

@@ -10,6 +10,8 @@ import (
 	"github.com/Control-D-Inc/ctrld"
 )
 
+const CtrldMarker = `# GENERATED BY ctrld - DO NOT MODIFY`
+
 const ConfigContentTmpl = `# GENERATED BY ctrld - DO NOT MODIFY
 no-resolv
 {{- range .Upstreams}}

internal/router/netgear_orbi_voxel/procd.go

@@ -0,0 +1,22 @@
+package netgear
+
+const openWrtScript = `#!/bin/sh /etc/rc.common
+USE_PROCD=1
+# After dnsmasq starts
+START=61
+# 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 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/netgear_orbi_voxel/voxel.go

@@ -0,0 +1,220 @@
+package netgear
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/kardianos/service"
+
+	"github.com/Control-D-Inc/ctrld"
+	"github.com/Control-D-Inc/ctrld/internal/router/dnsmasq"
+	"github.com/Control-D-Inc/ctrld/internal/router/nvram"
+)
+
+const (
+	Name                                = "netgear_orbi_voxel"
+	netgearOrbiVoxelDNSMasqConfigPath   = "/etc/dnsmasq.conf"
+	netgearOrbiVoxelHomedir             = "/mnt/bitdefender"
+	netgearOrbiVoxelStartupScript       = "/mnt/bitdefender/rc.user"
+	netgearOrbiVoxelStartupScriptBackup = "/mnt/bitdefender/rc.user.bak"
+	netgearOrbiVoxelStartupScriptMarker = "\n# GENERATED BY ctrld"
+)
+
+var nvramKvMap = map[string]string{
+	"dns_hijack": "0", // Disable dns hijacking
+}
+
+type NetgearOrbiVoxel struct {
+	cfg *ctrld.Config
+}
+
+// New returns a router.Router for configuring/setup/run ctrld on ddwrt routers.
+func New(cfg *ctrld.Config) *NetgearOrbiVoxel {
+	return &NetgearOrbiVoxel{cfg: cfg}
+}
+
+func (d *NetgearOrbiVoxel) ConfigureService(svc *service.Config) error {
+	if err := d.checkInstalledDir(); err != nil {
+		return err
+	}
+	svc.Option["SysvScript"] = openWrtScript
+	return nil
+}
+
+func (d *NetgearOrbiVoxel) Install(_ *service.Config) error {
+	// Ignoring error here at this moment is ok, since everything will be wiped out on reboot.
+	_ = exec.Command("/etc/init.d/ctrld", "enable").Run()
+	if err := d.checkInstalledDir(); err != nil {
+		return err
+	}
+	if err := backupVoxelStartupScript(); err != nil {
+		return fmt.Errorf("backup startup script: %w", err)
+	}
+	if err := writeVoxelStartupScript(); err != nil {
+		return fmt.Errorf("writing startup script: %w", err)
+	}
+	return nil
+}
+
+func (d *NetgearOrbiVoxel) Uninstall(_ *service.Config) error {
+	if err := os.Remove(netgearOrbiVoxelStartupScript); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	err := os.Rename(netgearOrbiVoxelStartupScriptBackup, netgearOrbiVoxelStartupScript)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}
+
+func (d *NetgearOrbiVoxel) PreRun() error {
+	return nil
+}
+
+func (d *NetgearOrbiVoxel) Setup() error {
+	if d.cfg.FirstListener().IsDirectDnsListener() {
+		return nil
+	}
+	// Already setup.
+	if val, _ := nvram.Run("get", nvram.CtrldSetupKey); val == "1" {
+		return nil
+	}
+
+	data, err := dnsmasq.ConfTmplWithCacheDisabled(dnsmasq.ConfigContentTmpl, d.cfg, false)
+	if err != nil {
+		return err
+	}
+	currentConfig, _ := os.ReadFile(netgearOrbiVoxelDNSMasqConfigPath)
+	configContent := append(currentConfig, data...)
+	if err := os.WriteFile(netgearOrbiVoxelDNSMasqConfigPath, configContent, 0600); err != nil {
+		return err
+	}
+	// Restart dnsmasq service.
+	if err := restartDNSMasq(); err != nil {
+		return err
+	}
+
+	if err := nvram.SetKV(nvramKvMap, nvram.CtrldSetupKey); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (d *NetgearOrbiVoxel) Cleanup() error {
+	if d.cfg.FirstListener().IsDirectDnsListener() {
+		return nil
+	}
+	if val, _ := nvram.Run("get", nvram.CtrldSetupKey); val != "1" {
+		return nil // was restored, nothing to do.
+	}
+
+	// Restore old configs.
+	if err := nvram.Restore(nvramKvMap, nvram.CtrldSetupKey); err != nil {
+		return err
+	}
+
+	// Restore dnsmasq config.
+	if err := restoreDnsmasqConf(); err != nil {
+		return err
+	}
+
+	// Restart dnsmasq service.
+	if err := restartDNSMasq(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// checkInstalledDir checks that ctrld binary was installed in the correct directory.
+func (d *NetgearOrbiVoxel) checkInstalledDir() error {
+	exePath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("checkHomeDir: failed to get binary path %w", err)
+	}
+	if !strings.HasSuffix(filepath.Dir(exePath), netgearOrbiVoxelHomedir) {
+		return fmt.Errorf("checkHomeDir: could not install service outside %s", netgearOrbiVoxelHomedir)
+	}
+	return nil
+}
+
+// backupVoxelStartupScript creates a backup of original startup script if existed.
+func backupVoxelStartupScript() error {
+	// Do nothing if the startup script was modified by ctrld.
+	script, _ := os.ReadFile(netgearOrbiVoxelStartupScript)
+	if bytes.Contains(script, []byte(netgearOrbiVoxelStartupScriptMarker)) {
+		return nil
+	}
+	err := os.Rename(netgearOrbiVoxelStartupScript, netgearOrbiVoxelStartupScriptBackup)
+	if err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("backupVoxelStartupScript: %w", err)
+	}
+	return nil
+}
+
+// writeVoxelStartupScript writes startup script to re-install ctrld upon reboot.
+// See: https://github.com/SVoxel/ORBI-RBK50/pull/7
+func writeVoxelStartupScript() error {
+	exe, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("configure service: failed to get binary path %w", err)
+	}
+	// This is called when "ctrld start ..." runs, so recording
+	// the same command line arguments to use in startup script.
+	argStr := strings.Join(os.Args[1:], " ")
+	script, _ := os.ReadFile(netgearOrbiVoxelStartupScriptBackup)
+	script = append(script, fmt.Sprintf("%s\n%q %s\n", netgearOrbiVoxelStartupScriptMarker, exe, argStr)...)
+	f, err := os.Create(netgearOrbiVoxelStartupScript)
+	if err != nil {
+		return fmt.Errorf("failed to create startup script: %w", err)
+	}
+	defer f.Close()
+
+	if _, err := f.Write(script); err != nil {
+		return fmt.Errorf("failed to write startup script: %w", err)
+	}
+	if err := f.Close(); err != nil {
+		return fmt.Errorf("failed to save startup script: %w", err)
+	}
+	return nil
+}
+
+// restoreDnsmasqConf restores original dnsmasq configuration.
+func restoreDnsmasqConf() error {
+	f, err := os.Open(netgearOrbiVoxelDNSMasqConfigPath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	var bs []byte
+	buf := bytes.NewBuffer(bs)
+
+	removed := false
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if line == dnsmasq.CtrldMarker {
+			removed = true
+		}
+		if !removed {
+			_, err := buf.WriteString(line + "\n")
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return os.WriteFile(netgearOrbiVoxelDNSMasqConfigPath, buf.Bytes(), 0644)
+}
+
+func restartDNSMasq() error {
+	if out, err := exec.Command("/etc/init.d/dnsmasq", "restart").CombinedOutput(); err != nil {
+		return fmt.Errorf("restartDNSMasq: %s, %w", string(out), err)
+	}
+	return nil
+}

internal/router/router.go

@@ -18,6 +18,7 @@ import (
 	"github.com/Control-D-Inc/ctrld/internal/router/edgeos"
 	"github.com/Control-D-Inc/ctrld/internal/router/firewalla"
 	"github.com/Control-D-Inc/ctrld/internal/router/merlin"
+	netgear "github.com/Control-D-Inc/ctrld/internal/router/netgear_orbi_voxel"
 	"github.com/Control-D-Inc/ctrld/internal/router/openwrt"
 	"github.com/Control-D-Inc/ctrld/internal/router/synology"
 	"github.com/Control-D-Inc/ctrld/internal/router/tomato"
@@ -66,10 +67,17 @@ func New(cfg *ctrld.Config, cdMode bool) Router {
 		return tomato.New(cfg)
 	case firewalla.Name:
 		return firewalla.New(cfg)
+	case netgear.Name:
+		return netgear.New(cfg)
 	}
 	return newOsRouter(cfg, cdMode)
 }
 
+// IsNetGearOrbi reports whether the router is a Netgear Orbi router.
+func IsNetGearOrbi() bool {
+	return Name() == netgear.Name
+}
+
 // IsGLiNet reports whether the router is an GL.iNet router.
 func IsGLiNet() bool {
 	if Name() != openwrt.Name {
@@ -145,7 +153,7 @@ func LocalResolverIP() string {
 // HomeDir returns the home directory of ctrld on current router.
 func HomeDir() (string, error) {
 	switch Name() {
-	case ddwrt.Name, firewalla.Name, merlin.Name, tomato.Name:
+	case ddwrt.Name, firewalla.Name, merlin.Name, netgear.Name, tomato.Name:
 		exe, err := os.Executable()
 		if err != nil {
 			return "", err
@@ -198,6 +206,9 @@ func distroName() string {
 	case bytes.HasPrefix(unameO(), []byte("ASUSWRT-Merlin")):
 		return merlin.Name
 	case haveFile("/etc/openwrt_version"):
+		if haveFile("/bin/config") { // TODO: is there any more reliable way?
+			return netgear.Name
+		}
 		return openwrt.Name
 	case isUbios():
 		return ubios.Name