all: add support for Synology router

internal/router/dnsmasq.go

@@ -49,7 +49,7 @@ func dnsMasqConf() (string, error) {
 	var sb strings.Builder
 	var tmplText string
 	switch Name() {
-	case DDWrt, OpenWrt, Ubios:
+	case DDWrt, OpenWrt, Ubios, Synology:
 		tmplText = dnsMasqConfigContentTmpl
 	case Merlin:
 		tmplText = merlinDNSMasqPostConfTmpl

internal/router/openwrt.go

@@ -28,7 +28,6 @@ func setupOpenWrt() error {
 	if _, err := uci("delete", "dhcp.@dnsmasq[0].port"); err != nil && !errors.Is(err, errUCIEntryNotFound) {
 		return err
 	}
-	// Disable dnsmasq as DNS server.
 	dnsMasqConfigContent, err := dnsMasqConf()
 	if err != nil {
 		return err

internal/router/router.go

@@ -19,10 +19,11 @@ import (
 )
 
 const (
-	OpenWrt = "openwrt"
-	DDWrt   = "ddwrt"
-	Merlin  = "merlin"
-	Ubios   = "ubios"
+	OpenWrt  = "openwrt"
+	DDWrt    = "ddwrt"
+	Merlin   = "merlin"
+	Ubios    = "ubios"
+	Synology = "synology"
 )
 
 // ErrNotSupported reports the current router is not supported error.
@@ -39,21 +40,22 @@ type router struct {
 
 // SupportedPlatforms return all platforms that can be configured to run with ctrld.
 func SupportedPlatforms() []string {
-	return []string{DDWrt, Merlin, OpenWrt, Ubios}
+	return []string{DDWrt, Merlin, OpenWrt, Ubios, Synology}
 }
 
 var configureFunc = map[string]func() error{
-	DDWrt:   setupDDWrt,
-	Merlin:  setupMerlin,
-	OpenWrt: setupOpenWrt,
-	Ubios:   setupUbiOS,
+	DDWrt:    setupDDWrt,
+	Merlin:   setupMerlin,
+	OpenWrt:  setupOpenWrt,
+	Ubios:    setupUbiOS,
+	Synology: setupSynology,
 }
 
 // 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 DDWrt, Merlin, OpenWrt, Ubios, Synology:
 		if c.HasUpstreamSendClientInfo() {
 			r := routerPlatform.Load()
 			r.sendClientInfo = true
@@ -88,7 +90,7 @@ func ConfigureService(sc *service.Config) error {
 		}
 	case OpenWrt:
 		sc.Option["SysvScript"] = openWrtScript
-	case Merlin, Ubios:
+	case Merlin, Ubios, Synology:
 	}
 	return nil
 }
@@ -151,6 +153,8 @@ func PostInstall() error {
 		return postInstallOpenWrt()
 	case Ubios:
 		return postInstallUbiOS()
+	case Synology:
+		return postInstallSynology()
 	}
 	return nil
 }
@@ -167,6 +171,8 @@ func Cleanup() error {
 		return cleanupOpenWrt()
 	case Ubios:
 		return cleanupUbiOS()
+	case Synology:
+		return cleanupSynology()
 	}
 	return nil
 }
@@ -175,7 +181,7 @@ func Cleanup() error {
 func ListenAddress() string {
 	name := Name()
 	switch name {
-	case DDWrt, Merlin, OpenWrt, Ubios:
+	case DDWrt, Merlin, OpenWrt, Ubios, Synology:
 		return "127.0.0.1:5354"
 	}
 	return ""
@@ -194,14 +200,16 @@ func Name() string {
 
 func distroName() string {
 	switch {
-	case bytes.HasPrefix(uname(), []byte("DD-WRT")):
+	case bytes.HasPrefix(unameO(), []byte("DD-WRT")):
 		return DDWrt
-	case bytes.HasPrefix(uname(), []byte("ASUSWRT-Merlin")):
+	case bytes.HasPrefix(unameO(), []byte("ASUSWRT-Merlin")):
 		return Merlin
 	case haveFile("/etc/openwrt_version"):
 		return OpenWrt
 	case haveDir("/data/unifi"):
 		return Ubios
+	case bytes.HasPrefix(unameU(), []byte("synology")):
+		return Synology
 	}
 	return ""
 }
@@ -216,7 +224,12 @@ func haveDir(dir string) bool {
 	return fi != nil && fi.IsDir()
 }
 
-func uname() []byte {
+func unameO() []byte {
 	out, _ := exec.Command("uname", "-o").Output()
 	return out
 }
+
+func unameU() []byte {
+	out, _ := exec.Command("uname", "-u").Output()
+	return out
+}

internal/router/synology.go

@@ -0,0 +1,55 @@
+package router
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+const (
+	synologyDNSMasqConfigPath = "/etc/dhcpd/dhcpd-zzz-ctrld.conf"
+	synologyDhcpdInfoPath     = "/etc/dhcpd/dhcpd-zzz-ctrld.info"
+)
+
+func setupSynology() error {
+	dnsMasqConfigContent, err := dnsMasqConf()
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(synologyDNSMasqConfigPath, []byte(dnsMasqConfigContent), 0600); err != nil {
+		return err
+	}
+	if err := os.WriteFile(synologyDhcpdInfoPath, []byte(`enable="yes"`), 0600); err != nil {
+		return err
+	}
+	if err := synologyRestartDNSMasq(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func cleanupSynology() error {
+	// Remove the custom config files.
+	for _, f := range []string{synologyDNSMasqConfigPath, synologyDhcpdInfoPath} {
+		if err := os.Remove(f); err != nil {
+			return err
+		}
+	}
+
+	// Restart dnsmasq service.
+	if err := synologyRestartDNSMasq(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func postInstallSynology() error {
+	return nil
+}
+
+func synologyRestartDNSMasq() error {
+	if out, err := exec.Command("/etc/rc.network", "nat-restart-dhcp").CombinedOutput(); err != nil {
+		return fmt.Errorf("synologyRestartDNSMasq: %s - %w", string(out), err)
+	}
+	return nil
+}