New ip-version option for listeners

cmd/routedns/config.go

@@ -22,6 +22,7 @@ type config struct {
 type listener struct {
 	Address    string
 	Protocol   string
+	IPVersion  int `toml:"ip-version"` // 4 = IPv4, 6 = IPv6
 	Transport  string
 	Resolver   string
 	CA         string

cmd/routedns/main.go

@@ -196,15 +196,21 @@ func start(opt options, args []string) error {
 			return err
 		}
 
+		if l.IPVersion != 4 && l.IPVersion != 6 && l.IPVersion != 0 {
+			return errors.New("ip-version must be 4 or 6")
+		}
+
 		opt := rdns.ListenOptions{AllowedNet: allowedNet}
 
 		switch l.Protocol {
 		case "tcp":
+			network := networkForIPVersion("tcp", l.IPVersion)
 			l.Address = rdns.AddressWithDefault(l.Address, rdns.PlainDNSPort)
-			listeners = append(listeners, rdns.NewDNSListener(id, l.Address, "tcp", opt, resolver))
+			listeners = append(listeners, rdns.NewDNSListener(id, l.Address, network, opt, resolver))
 		case "udp":
+			network := networkForIPVersion("udp", l.IPVersion)
 			l.Address = rdns.AddressWithDefault(l.Address, rdns.PlainDNSPort)
-			listeners = append(listeners, rdns.NewDNSListener(id, l.Address, "udp", opt, resolver))
+			listeners = append(listeners, rdns.NewDNSListener(id, l.Address, network, opt, resolver))
 		case "admin":
 			tlsConfig, err := rdns.TLSServerConfig(l.CA, l.ServerCrt, l.ServerKey, l.MutualTLS)
 			if err != nil {
@@ -221,12 +227,13 @@ func start(opt options, args []string) error {
 			}
 			listeners = append(listeners, ln)
 		case "dot":
+			network := networkForIPVersion("tcp", l.IPVersion)
 			l.Address = rdns.AddressWithDefault(l.Address, rdns.DoTPort)
 			tlsConfig, err := rdns.TLSServerConfig(l.CA, l.ServerCrt, l.ServerKey, l.MutualTLS)
 			if err != nil {
 				return err
 			}
-			ln := rdns.NewDoTListener(id, l.Address, rdns.DoTListenerOptions{TLSConfig: tlsConfig, ListenOptions: opt}, resolver)
+			ln := rdns.NewDoTListener(id, l.Address, network, rdns.DoTListenerOptions{TLSConfig: tlsConfig, ListenOptions: opt}, resolver)
 			listeners = append(listeners, ln)
 		case "dtls":
 			l.Address = rdns.AddressWithDefault(l.Address, rdns.DTLSPort)
@@ -248,7 +255,6 @@ func start(opt options, args []string) error {
 					return errors.New("no-tls is not supported for doh servers with quic transport")
 				}
 			} else {
-				fmt.Println("p4")
 				tlsConfig, err = rdns.TLSServerConfig(l.CA, l.ServerCrt, l.ServerKey, l.MutualTLS)
 				if err != nil {
 					return err
@@ -892,6 +898,13 @@ func newIPBlocklistDB(l list, locationDB string, rules []string) (rdns.IPBlockli
 	}
 }
 
+func networkForIPVersion(base string, ipVersion int) string {
+	if ipVersion == 0 {
+		return base
+	}
+	return base + strconv.Itoa(ipVersion)
+}
+
 func printVersion() {
 	fmt.Println("Build: ", rdns.BuildNumber)
 	fmt.Println("Build Time: ", rdns.BuildTime)

doc/configuration.md

@@ -119,6 +119,7 @@ Common options for all listeners:
 
 - `address` - Listen address.
 - `protocol` - The DNS protocol used to receive queries, can be `udp`, `tcp`, `dot`, `doh`, `doq`.
+- `ip-version` - IP version (4 or 6) to use for the listener. Optional, defaults to both.
 - `resolver` - Name/identifier of the next element in the pipeline. Can be a router, group, modifier or resolver.
 - `allowed-net` - Array of network addresses that are allowed to send queries to this listener, in CIDR notation, such as `["192.167.1.0/24", "::1/128"]`. If not set, no filter is applied, all clients can send queries.
 

dotlistener.go

@@ -23,12 +23,15 @@ type DoTListenerOptions struct {
 }
 
 // NewDoTListener returns an instance of a DNS-over-TLS listener.
-func NewDoTListener(id, addr string, opt DoTListenerOptions, resolver Resolver) *DoTListener {
+func NewDoTListener(id, addr, network string, opt DoTListenerOptions, resolver Resolver) *DoTListener {
+	if network == "" {
+		network = "tcp-tls"
+	}
 	return &DoTListener{
 		id: id,
 		Server: &dns.Server{
 			Addr:      addr,
-			Net:       "tcp-tls",
+			Net:       network,
 			TLSConfig: opt.TLSConfig,
 			Handler:   listenHandler(id, "dot", addr, resolver, opt.AllowedNet),
 		},