add router handler option

cmd/gost/config.go

@@ -71,12 +71,12 @@ func buildService(cfg *config.Config) (services []*service.Service) {
 		h := registry.GetHandler(svc.Handler.Type)(
 			handler.BypassOption(bypasses[svc.Bypass]),
 			handler.LoggerOption(handlerLogger),
+			handler.RouterOption(&chain.Router{
+				Chain:  chains[svc.Chain],
+				Logger: handlerLogger,
+			}),
 		)
 
-		if chainable, ok := h.(chain.Chainable); ok {
-			chainable.WithChain(chains[svc.Chain])
-		}
-
 		if forwarder, ok := h.(handler.Forwarder); ok {
 			forwarder.Forward(forwarderFromConfig(svc.Forwarder))
 		}

pkg/chain/router.go

@@ -13,30 +13,10 @@ import (
 )
 
 type Router struct {
-	retries  int
+	Retries  int
-	chain    *Chain
+	Chain    *Chain
-	resolver resolver.Resolver
+	Resolver resolver.Resolver
-	logger   logger.Logger
+	Logger   logger.Logger
-}
-
-func (r *Router) WithChain(chain *Chain) *Router {
-	r.chain = chain
-	return r
-}
-
-func (r *Router) WithResolver(resolver resolver.Resolver) *Router {
-	r.resolver = resolver
-	return r
-}
-
-func (r *Router) WithRetry(retries int) *Router {
-	r.retries = retries
-	return r
-}
-
-func (r *Router) WithLogger(logger logger.Logger) *Router {
-	r.logger = logger
-	return r
 }
 
 func (r *Router) Dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
@@ -53,27 +33,27 @@ func (r *Router) Dial(ctx context.Context, network, address string) (conn net.Co
 }
 
 func (r *Router) dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
-	count := r.retries + 1
+	count := r.Retries + 1
 	if count <= 0 {
 		count = 1
 	}
-	r.logger.Debugf("dial %s/%s", address, network)
+	r.Logger.Debugf("dial %s/%s", address, network)
 
 	for i := 0; i < count; i++ {
-		route := r.chain.GetRouteFor(network, address)
+		route := r.Chain.GetRouteFor(network, address)
 
-		if r.logger.IsLevelEnabled(logger.DebugLevel) {
+		if r.Logger.IsLevelEnabled(logger.DebugLevel) {
 			buf := bytes.Buffer{}
 			for _, node := range route.Path() {
 				fmt.Fprintf(&buf, "%s@%s > ", node.Name(), node.Addr())
 			}
 			fmt.Fprintf(&buf, "%s", address)
-			r.logger.Debugf("route(retry=%d) %s", i, buf.String())
+			r.Logger.Debugf("route(retry=%d) %s", i, buf.String())
 		}
 
 		address, err = r.resolve(ctx, address)
 		if err != nil {
-			r.logger.Error(err)
+			r.Logger.Error(err)
 			break
 		}
 
@@ -81,15 +61,19 @@ func (r *Router) dial(ctx context.Context, network, address string) (conn net.Co
 		if err == nil {
 			break
 		}
-		r.logger.Errorf("route(retry=%d) %s", i, err)
+		r.Logger.Errorf("route(retry=%d) %s", i, err)
 	}
 
 	return
 }
 
 func (r *Router) resolve(ctx context.Context, addr string) (string, error) {
+	if addr == "" {
+		return addr, nil
+	}
+
 	host, port, err := net.SplitHostPort(addr)
-	if err != nil {
+	if err != nil || host == "" {
 		return "", err
 	}
 
@@ -99,10 +83,10 @@ func (r *Router) resolve(ctx context.Context, addr string) (string, error) {
 		}
 	*/
 
-	if r.resolver != nil {
+	if r.Resolver != nil {
-		ips, err := r.resolver.Resolve(ctx, host)
+		ips, err := r.Resolver.Resolve(ctx, host)
 		if err != nil {
-			r.logger.Error(err)
+			r.Logger.Error(err)
 		}
 		if len(ips) == 0 {
 			return "", errors.New("domain not exists")
@@ -113,29 +97,29 @@ func (r *Router) resolve(ctx context.Context, addr string) (string, error) {
 }
 
 func (r *Router) Bind(ctx context.Context, network, address string, opts ...connector.BindOption) (ln net.Listener, err error) {
-	count := r.retries + 1
+	count := r.Retries + 1
 	if count <= 0 {
 		count = 1
 	}
-	r.logger.Debugf("bind on %s/%s", address, network)
+	r.Logger.Debugf("bind on %s/%s", address, network)
 
 	for i := 0; i < count; i++ {
-		route := r.chain.GetRouteFor(network, address)
+		route := r.Chain.GetRouteFor(network, address)
 
-		if r.logger.IsLevelEnabled(logger.DebugLevel) {
+		if r.Logger.IsLevelEnabled(logger.DebugLevel) {
 			buf := bytes.Buffer{}
 			for _, node := range route.Path() {
 				fmt.Fprintf(&buf, "%s@%s > ", node.Name(), node.Addr())
 			}
 			fmt.Fprintf(&buf, "%s", address)
-			r.logger.Debugf("route(retry=%d) %s", i, buf.String())
+			r.Logger.Debugf("route(retry=%d) %s", i, buf.String())
 		}
 
 		ln, err = route.Bind(ctx, network, address, opts...)
 		if err == nil {
 			break
 		}
-		r.logger.Errorf("route(retry=%d) %s", i, err)
+		r.Logger.Errorf("route(retry=%d) %s", i, err)
 	}
 
 	return

pkg/handler/auto/handler.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/go-gost/gosocks4"
 	"github.com/go-gost/gosocks5"
-	"github.com/go-gost/gost/pkg/chain"
 	"github.com/go-gost/gost/pkg/handler"
 	"github.com/go-gost/gost/pkg/logger"
 	md "github.com/go-gost/gost/pkg/metadata"
@@ -21,7 +20,6 @@ func init() {
 }
 
 type autoHandler struct {
-	chain         *chain.Chain
 	httpHandler   handler.Handler
 	socks4Handler handler.Handler
 	socks5Handler handler.Handler
@@ -68,43 +66,23 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 	return h
 }
 
-func (h *autoHandler) WithChain(chain *chain.Chain) {
-	h.chain = chain
-}
-
 func (h *autoHandler) Init(md md.Metadata) error {
 	if h.httpHandler != nil {
-		if chainable, ok := h.httpHandler.(chain.Chainable); ok {
-			chainable.WithChain(h.chain)
-		}
-
 		if err := h.httpHandler.Init(md); err != nil {
 			return err
 		}
 	}
 	if h.socks4Handler != nil {
-		if chainable, ok := h.socks4Handler.(chain.Chainable); ok {
-			chainable.WithChain(h.chain)
-		}
-
 		if err := h.socks4Handler.Init(md); err != nil {
 			return err
 		}
 	}
 	if h.socks5Handler != nil {
-		if chainable, ok := h.socks5Handler.(chain.Chainable); ok {
-			chainable.WithChain(h.chain)
-		}
-
 		if err := h.socks5Handler.Init(md); err != nil {
 			return err
 		}
 	}
 	if h.relayHandler != nil {
-		if chainable, ok := h.relayHandler.(chain.Chainable); ok {
-			chainable.WithChain(h.chain)
-		}
-
 		if err := h.relayHandler.Init(md); err != nil {
 			return err
 		}

pkg/handler/dns/handler.go

@@ -21,13 +21,17 @@ import (
 	"github.com/miekg/dns"
 )
 
+const (
+	defaultNameserver = "udp://127.0.0.1:53"
+)
+
 func init() {
 	registry.RegisterHandler("dns", NewHandler)
 }
 
 type dnsHandler struct {
-	chain      *chain.Chain
 	bypass     bypass.Bypass
+	router     *chain.Router
 	exchangers []exchanger.Exchanger
 	cache      *resolver_util.Cache
 	logger     logger.Logger
@@ -44,6 +48,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &dnsHandler{
 		bypass: options.Bypass,
+		router: options.Router,
 		cache:  cache,
 		logger: options.Logger,
 	}
@@ -61,7 +66,7 @@ func (h *dnsHandler) Init(md md.Metadata) (err error) {
 		}
 		ex, err := exchanger.NewExchanger(
 			server,
-			exchanger.ChainOption(h.chain),
+			exchanger.RouterOption(h.router),
 			exchanger.TimeoutOption(h.md.timeout),
 			exchanger.LoggerOption(h.logger),
 		)
@@ -72,14 +77,13 @@ func (h *dnsHandler) Init(md md.Metadata) (err error) {
 		h.exchangers = append(h.exchangers, ex)
 	}
 	if len(h.exchangers) == 0 {
-		addr := "udp://127.0.0.1:53"
 		ex, err := exchanger.NewExchanger(
-			addr,
+			defaultNameserver,
-			exchanger.ChainOption(h.chain),
+			exchanger.RouterOption(h.router),
 			exchanger.TimeoutOption(h.md.timeout),
 			exchanger.LoggerOption(h.logger),
 		)
-		h.logger.Warnf("resolver not found, default to %s", addr)
+		h.logger.Warnf("resolver not found, default to %s", defaultNameserver)
 		if err != nil {
 			return err
 		}
@@ -88,11 +92,6 @@ func (h *dnsHandler) Init(md md.Metadata) (err error) {
 	return
 }
 
-// implements chain.Chainable interface
-func (h *dnsHandler) WithChain(chain *chain.Chain) {
-	h.chain = chain
-}
-
 func (h *dnsHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/dns/metadata.go

@@ -10,7 +10,6 @@ import (
 
 type metadata struct {
 	readTimeout time.Duration
-	retryCount  int
 	ttl         time.Duration
 	timeout     time.Duration
 	clientIP    net.IP
@@ -22,7 +21,6 @@ type metadata struct {
 func (h *dnsHandler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 		ttl         = "ttl"
 		timeout     = "timeout"
 		clientIP    = "clientIP"
@@ -31,7 +29,6 @@ func (h *dnsHandler) parseMetadata(md mdata.Metadata) (err error) {
 	)
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	h.md.ttl = mdata.GetDuration(md, ttl)
 	h.md.timeout = mdata.GetDuration(md, timeout)
 	if h.md.timeout <= 0 {

pkg/handler/forward/local/handler.go

@@ -22,8 +22,8 @@ func init() {
 
 type forwardHandler struct {
 	group  *chain.NodeGroup
-	chain  *chain.Chain
 	bypass bypass.Bypass
+	router *chain.Router
 	logger logger.Logger
 	md     metadata
 }
@@ -36,6 +36,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &forwardHandler{
 		bypass: options.Bypass,
+		router: options.Router,
 		logger: options.Logger,
 	}
 }
@@ -49,12 +50,8 @@ func (h *forwardHandler) Init(md md.Metadata) (err error) {
 		// dummy node used by relay connector.
 		h.group = chain.NewNodeGroup(chain.NewNode("dummy", ":0"))
 	}
-	return nil
-}
 
-// WithChain implements chain.Chainable interface
+	return nil
-func (h *forwardHandler) WithChain(chain *chain.Chain) {
-	h.chain = chain
 }
 
 // Forward implements handler.Forwarder.
@@ -95,12 +92,7 @@ func (h *forwardHandler) Handle(ctx context.Context, conn net.Conn) {
 
 	h.logger.Infof("%s >> %s", conn.RemoteAddr(), target.Addr())
 
-	r := (&chain.Router{}).
+	cc, err := h.router.Dial(ctx, network, target.Addr())
-		WithChain(h.chain).
-		WithRetry(h.md.retryCount).
-		WithLogger(h.logger)
-
-	cc, err := r.Dial(ctx, network, target.Addr())
 	if err != nil {
 		h.logger.Error(err)
 		// TODO: the router itself may be failed due to the failed node in the router,

pkg/handler/forward/local/metadata.go

@@ -8,16 +8,13 @@ import (
 
 type metadata struct {
 	readTimeout time.Duration
-	retryCount  int
 }
 
 func (h *forwardHandler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 	)
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	return
 }

pkg/handler/forward/remote/handler.go

@@ -22,6 +22,7 @@ func init() {
 type forwardHandler struct {
 	group  *chain.NodeGroup
 	bypass bypass.Bypass
+	router *chain.Router
 	logger logger.Logger
 	md     metadata
 }
@@ -34,12 +35,20 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &forwardHandler{
 		bypass: options.Bypass,
+		router: &chain.Router{
+			Retries:  options.Router.Retries,
+			Resolver: options.Resolver,
+			Logger:   options.Logger,
+		},
 		logger: options.Logger,
 	}
 }
 
 func (h *forwardHandler) Init(md md.Metadata) (err error) {
-	return h.parseMetadata(md)
+	if err = h.parseMetadata(md); err != nil {
+		return
+	}
+	return
 }
 
 // Forward implements handler.Forwarder.
@@ -80,12 +89,7 @@ func (h *forwardHandler) Handle(ctx context.Context, conn net.Conn) {
 
 	h.logger.Infof("%s >> %s", conn.RemoteAddr(), target.Addr())
 
-	// without chain
+	cc, err := h.router.Dial(ctx, network, target.Addr())
-	r := (&chain.Router{}).
-		WithRetry(h.md.retryCount).
-		WithLogger(h.logger)
-
-	cc, err := r.Dial(ctx, network, target.Addr())
 	if err != nil {
 		h.logger.Error(err)
 		// TODO: the router itself may be failed due to the failed node in the router,

pkg/handler/forward/remote/metadata.go

@@ -8,16 +8,13 @@ import (
 
 type metadata struct {
 	readTimeout time.Duration
-	retryCount  int
 }
 
 func (h *forwardHandler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 	)
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	return
 }

pkg/handler/forward/ssh/handler.go

@@ -31,9 +31,9 @@ func init() {
 }
 
 type forwardHandler struct {
-	chain  *chain.Chain
 	bypass bypass.Bypass
 	config *ssh.ServerConfig
+	router *chain.Router
 	logger logger.Logger
 	md     metadata
 }
@@ -46,6 +46,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &forwardHandler{
 		bypass: options.Bypass,
+		router: options.Router,
 		logger: options.Logger,
 	}
 }
@@ -71,11 +72,6 @@ func (h *forwardHandler) Init(md md.Metadata) (err error) {
 	return nil
 }
 
-// WithChain implements chain.Chainable interface
-func (h *forwardHandler) WithChain(chain *chain.Chain) {
-	h.chain = chain
-}
-
 func (h *forwardHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 
@@ -168,11 +164,7 @@ func (h *forwardHandler) directPortForwardChannel(ctx context.Context, channel s
 		return
 	}
 
-	r := (&chain.Router{}).
+	conn, err := h.router.Dial(ctx, "tcp", raddr)
-		WithChain(h.chain).
-		// WithRetry(h.md.retryCount).
-		WithLogger(h.logger)
-	conn, err := r.Dial(ctx, "tcp", raddr)
 	if err != nil {
 		return
 	}

pkg/handler/http/handler.go

@@ -43,9 +43,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &httpHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -55,16 +53,9 @@ func (h *httpHandler) Init(md md.Metadata) error {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *httpHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *httpHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/http/metadata.go

@@ -9,7 +9,6 @@ import (
 )
 
 type metadata struct {
-	retryCount    int
 	authenticator auth.Authenticator
 	probeResist   *probeResist
 	sni           bool
@@ -23,7 +22,6 @@ func (h *httpHandler) parseMetadata(md mdata.Metadata) error {
 		users          = "users"
 		probeResistKey = "probeResist"
 		knock          = "knock"
-		retryCount     = "retry"
 		sni            = "sni"
 		enableUDP      = "udp"
 	)
@@ -58,7 +56,6 @@ func (h *httpHandler) parseMetadata(md mdata.Metadata) error {
 			}
 		}
 	}
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	h.md.sni = mdata.GetBool(md, sni)
 	h.md.enableUDP = mdata.GetBool(md, enableUDP)
 

pkg/handler/http2/handler.go

@@ -43,9 +43,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &http2Handler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -55,16 +53,9 @@ func (h *http2Handler) Init(md md.Metadata) error {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *http2Handler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *http2Handler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/http2/metadata.go

@@ -10,7 +10,6 @@ import (
 type metadata struct {
 	authenticator auth.Authenticator
 	proxyAgent    string
-	retryCount    int
 	probeResist   *probeResist
 	sni           bool
 	enableUDP     bool
@@ -22,7 +21,6 @@ func (h *http2Handler) parseMetadata(md mdata.Metadata) error {
 		users          = "users"
 		probeResistKey = "probeResist"
 		knock          = "knock"
-		retryCount     = "retry"
 		sni            = "sni"
 		enableUDP      = "udp"
 	)
@@ -51,7 +49,6 @@ func (h *http2Handler) parseMetadata(md mdata.Metadata) error {
 			}
 		}
 	}
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	h.md.sni = mdata.GetBool(md, sni)
 	h.md.enableUDP = mdata.GetBool(md, enableUDP)
 

pkg/handler/option.go

@@ -2,11 +2,13 @@ package handler
 
 import (
 	"github.com/go-gost/gost/pkg/bypass"
+	"github.com/go-gost/gost/pkg/chain"
 	"github.com/go-gost/gost/pkg/logger"
 	"github.com/go-gost/gost/pkg/resolver"
 )
 
 type Options struct {
+	Router   *chain.Router
 	Bypass   bypass.Bypass
 	Resolver resolver.Resolver
 	Logger   logger.Logger
@@ -14,9 +16,9 @@ type Options struct {
 
 type Option func(opts *Options)
 
-func LoggerOption(logger logger.Logger) Option {
+func RouterOption(router *chain.Router) Option {
 	return func(opts *Options) {
-		opts.Logger = logger
+		opts.Router = router
 	}
 }
 
@@ -26,8 +28,8 @@ func BypassOption(bypass bypass.Bypass) Option {
 	}
 }
 
-func ResolverOption(resolver resolver.Resolver) Option {
+func LoggerOption(logger logger.Logger) Option {
 	return func(opts *Options) {
-		opts.Resolver = resolver
+		opts.Logger = logger
 	}
 }

pkg/handler/redirect/handler.go

@@ -22,8 +22,8 @@ func init() {
 }
 
 type redirectHandler struct {
-	chain  *chain.Chain
 	bypass bypass.Bypass
+	router *chain.Router
 	logger logger.Logger
 	md     metadata
 }
@@ -36,6 +36,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &redirectHandler{
 		bypass: options.Bypass,
+		router: options.Router,
 		logger: options.Logger,
 	}
 }
@@ -44,11 +45,6 @@ func (h *redirectHandler) Init(md md.Metadata) (err error) {
 	return h.parseMetadata(md)
 }
 
-// WithChain implements chain.Chainable interface
-func (h *redirectHandler) WithChain(chain *chain.Chain) {
-	h.chain = chain
-}
-
 func (h *redirectHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 
@@ -93,12 +89,7 @@ func (h *redirectHandler) Handle(ctx context.Context, conn net.Conn) {
 		return
 	}
 
-	r := (&chain.Router{}).
+	cc, err := h.router.Dial(ctx, network, dstAddr.String())
-		WithChain(h.chain).
-		WithRetry(h.md.retryCount).
-		WithLogger(h.logger)
-
-	cc, err := r.Dial(ctx, network, dstAddr.String())
 	if err != nil {
 		h.logger.Error(err)
 		return

pkg/handler/relay/handler.go

@@ -35,9 +35,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &relayHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -47,16 +45,9 @@ func (h *relayHandler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// WithChain implements chain.Chainable interface
-func (h *relayHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 // Forward implements handler.Forwarder.
 func (h *relayHandler) Forward(group *chain.NodeGroup) {
 	h.group = group

pkg/handler/relay/metadata.go

@@ -12,7 +12,6 @@ import (
 type metadata struct {
 	authenticator auth.Authenticator
 	readTimeout   time.Duration
-	retryCount    int
 	enableBind    bool
 	udpBufferSize int
 	noDelay       bool
@@ -22,7 +21,6 @@ func (h *relayHandler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		users         = "users"
 		readTimeout   = "readTimeout"
-		retryCount    = "retry"
 		enableBind    = "bind"
 		udpBufferSize = "udpBufferSize"
 		noDelay       = "nodelay"
@@ -42,7 +40,6 @@ func (h *relayHandler) parseMetadata(md mdata.Metadata) (err error) {
 	}
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	h.md.enableBind = mdata.GetBool(md, enableBind)
 	h.md.noDelay = mdata.GetBool(md, noDelay)
 

pkg/handler/sni/handler.go

@@ -46,9 +46,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	h := &sniHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: log,
 	}
 
@@ -74,16 +72,9 @@ func (h *sniHandler) Init(md md.Metadata) (err error) {
 		}
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// WithChain implements chain.Chainable interface
-func (h *sniHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *sniHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/sni/metadata.go

@@ -8,16 +8,13 @@ import (
 
 type metadata struct {
 	readTimeout time.Duration
-	retryCount  int
 }
 
 func (h *sniHandler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 	)
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	return
 }

pkg/handler/socks/v4/handler.go

@@ -34,9 +34,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &socks4Handler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -46,16 +44,9 @@ func (h *socks4Handler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *socks4Handler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *socks4Handler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/socks/v4/metadata.go

@@ -10,14 +10,12 @@ import (
 type metadata struct {
 	authenticator auth.Authenticator
 	readTimeout   time.Duration
-	retryCount    int
 }
 
 func (h *socks4Handler) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		users       = "users"
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 	)
 
 	if auths := mdata.GetStrings(md, users); len(auths) > 0 {
@@ -31,6 +29,5 @@ func (h *socks4Handler) parseMetadata(md mdata.Metadata) (err error) {
 	}
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	return
 }

pkg/handler/socks/v5/handler.go

@@ -36,9 +36,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &socks5Handler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -55,16 +53,9 @@ func (h *socks5Handler) Init(md md.Metadata) (err error) {
 		noTLS:         h.md.noTLS,
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return
 }
 
-// implements chain.Chainable interface
-func (h *socks5Handler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *socks5Handler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/socks/v5/metadata.go

@@ -16,7 +16,6 @@ type metadata struct {
 	authenticator     auth.Authenticator
 	timeout           time.Duration
 	readTimeout       time.Duration
-	retryCount        int
 	noTLS             bool
 	enableBind        bool
 	enableUDP         bool
@@ -32,7 +31,6 @@ func (h *socks5Handler) parseMetadata(md mdata.Metadata) (err error) {
 		users             = "users"
 		readTimeout       = "readTimeout"
 		timeout           = "timeout"
-		retryCount        = "retry"
 		noTLS             = "notls"
 		enableBind        = "bind"
 		enableUDP         = "udp"
@@ -64,7 +62,6 @@ func (h *socks5Handler) parseMetadata(md mdata.Metadata) (err error) {
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
 	h.md.timeout = mdata.GetDuration(md, timeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 	h.md.noTLS = mdata.GetBool(md, noTLS)
 	h.md.enableBind = mdata.GetBool(md, enableBind)
 	h.md.enableUDP = mdata.GetBool(md, enableUDP)

pkg/handler/ss/handler.go

@@ -36,9 +36,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &ssHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -48,16 +46,9 @@ func (h *ssHandler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *ssHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *ssHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/ss/metadata.go

@@ -12,7 +12,6 @@ import (
 type metadata struct {
 	cipher      core.Cipher
 	readTimeout time.Duration
-	retryCount  int
 }
 
 func (h *ssHandler) parseMetadata(md mdata.Metadata) (err error) {
@@ -20,7 +19,6 @@ func (h *ssHandler) parseMetadata(md mdata.Metadata) (err error) {
 		users       = "users"
 		key         = "key"
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 	)
 
 	var method, password string
@@ -39,7 +37,6 @@ func (h *ssHandler) parseMetadata(md mdata.Metadata) (err error) {
 	}
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 
 	return
 }

pkg/handler/ss/udp/handler.go

@@ -35,9 +35,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &ssuHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 	}
 }
@@ -47,16 +45,9 @@ func (h *ssuHandler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// WithChain implements chain.Chainable interface
-func (h *ssuHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 func (h *ssuHandler) Handle(ctx context.Context, conn net.Conn) {
 	defer conn.Close()
 

pkg/handler/ss/udp/metadata.go

@@ -13,7 +13,6 @@ import (
 type metadata struct {
 	cipher      core.Cipher
 	readTimeout time.Duration
-	retryCount  int
 	bufferSize  int
 }
 
@@ -22,7 +21,6 @@ func (h *ssuHandler) parseMetadata(md mdata.Metadata) (err error) {
 		users       = "users"
 		key         = "key"
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 		bufferSize  = "bufferSize"
 	)
 
@@ -42,7 +40,6 @@ func (h *ssuHandler) parseMetadata(md mdata.Metadata) (err error) {
 	}
 
 	h.md.readTimeout = mdata.GetDuration(md, readTimeout)
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 
 	if bs := mdata.GetInt(md, bufferSize); bs > 0 {
 		h.md.bufferSize = int(math.Min(math.Max(float64(bs), 512), 64*1024))

pkg/handler/tap/handler.go

@@ -44,9 +44,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &tapHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 		exit:   make(chan struct{}, 1),
 	}
@@ -57,16 +55,9 @@ func (h *tapHandler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *tapHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 // Forward implements handler.Forwarder.
 func (h *tapHandler) Forward(group *chain.NodeGroup) {
 	h.group = group

pkg/handler/tap/metadata.go

@@ -19,7 +19,6 @@ func (h *tapHandler) parseMetadata(md mdata.Metadata) (err error) {
 		users       = "users"
 		key         = "key"
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 		bufferSize  = "bufferSize"
 	)
 
@@ -37,7 +36,6 @@ func (h *tapHandler) parseMetadata(md mdata.Metadata) (err error) {
 	if err != nil {
 		return
 	}
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 
 	h.md.bufferSize = mdata.GetInt(md, bufferSize)
 	if h.md.bufferSize <= 0 {

pkg/handler/tun/handler.go

@@ -46,9 +46,7 @@ func NewHandler(opts ...handler.Option) handler.Handler {
 
 	return &tunHandler{
 		bypass: options.Bypass,
-		router: (&chain.Router{}).
+		router: options.Router,
-			WithLogger(options.Logger).
-			WithResolver(options.Resolver),
 		logger: options.Logger,
 		exit:   make(chan struct{}, 1),
 	}
@@ -59,16 +57,9 @@ func (h *tunHandler) Init(md md.Metadata) (err error) {
 		return err
 	}
 
-	h.router.WithRetry(h.md.retryCount)
-
 	return nil
 }
 
-// implements chain.Chainable interface
-func (h *tunHandler) WithChain(chain *chain.Chain) {
-	h.router.WithChain(chain)
-}
-
 // Forward implements handler.Forwarder.
 func (h *tunHandler) Forward(group *chain.NodeGroup) {
 	h.group = group

pkg/handler/tun/metadata.go

@@ -10,7 +10,6 @@ import (
 
 type metadata struct {
 	cipher     core.Cipher
-	retryCount int
 	bufferSize int
 }
 
@@ -19,7 +18,6 @@ func (h *tunHandler) parseMetadata(md mdata.Metadata) (err error) {
 		users       = "users"
 		key         = "key"
 		readTimeout = "readTimeout"
-		retryCount  = "retry"
 		bufferSize  = "bufferSize"
 	)
 
@@ -37,7 +35,6 @@ func (h *tunHandler) parseMetadata(md mdata.Metadata) (err error) {
 	if err != nil {
 		return
 	}
-	h.md.retryCount = mdata.GetInt(md, retryCount)
 
 	h.md.bufferSize = mdata.GetInt(md, bufferSize)
 	if h.md.bufferSize <= 0 {

pkg/listener/rtcp/listener.go

@@ -22,6 +22,7 @@ type rtcpListener struct {
 	chain  *chain.Chain
 	ln     net.Listener
 	md     metadata
+	router *chain.Router
 	logger logger.Logger
 	closed chan struct{}
 }
@@ -34,13 +35,16 @@ func NewListener(opts ...listener.Option) listener.Listener {
 	return &rtcpListener{
 		addr:   options.Addr,
 		closed: make(chan struct{}),
+		router: &chain.Router{
+			Logger: options.Logger,
+		},
 		logger: options.Logger,
 	}
 }
 
 // implements chain.Chainable interface
 func (l *rtcpListener) WithChain(chain *chain.Chain) {
-	l.chain = chain
+	l.router.Chain = chain
 }
 
 func (l *rtcpListener) Init(md md.Metadata) (err error) {
@@ -66,11 +70,7 @@ func (l *rtcpListener) Accept() (conn net.Conn, err error) {
 	}
 
 	if l.ln == nil {
-		r := (&chain.Router{}).
+		l.ln, err = l.router.Bind(context.Background(), "tcp", l.laddr.String(),
-			WithChain(l.chain).
-			WithRetry(l.md.retryCount).
-			WithLogger(l.logger)
-		l.ln, err = r.Bind(context.Background(), "tcp", l.laddr.String(),
 			connector.MuxBindOption(true),
 		)
 		if err != nil {

pkg/listener/rudp/listener.go

@@ -22,6 +22,7 @@ type rudpListener struct {
 	chain  *chain.Chain
 	ln     net.Listener
 	md     metadata
+	router *chain.Router
 	logger logger.Logger
 	closed chan struct{}
 }
@@ -34,13 +35,16 @@ func NewListener(opts ...listener.Option) listener.Listener {
 	return &rudpListener{
 		addr:   options.Addr,
 		closed: make(chan struct{}),
+		router: &chain.Router{
+			Logger: options.Logger,
+		},
 		logger: options.Logger,
 	}
 }
 
 // implements chain.Chainable interface
 func (l *rudpListener) WithChain(chain *chain.Chain) {
-	l.chain = chain
+	l.router.Chain = chain
 }
 
 func (l *rudpListener) Init(md md.Metadata) (err error) {
@@ -66,11 +70,7 @@ func (l *rudpListener) Accept() (conn net.Conn, err error) {
 	}
 
 	if l.ln == nil {
-		r := (&chain.Router{}).
+		l.ln, err = l.router.Bind(context.Background(), "udp", l.laddr.String(),
-			WithChain(l.chain).
-			WithRetry(l.md.retryCount).
-			WithLogger(l.logger)
-		l.ln, err = r.Bind(context.Background(), "udp", l.laddr.String(),
 			connector.BacklogBindOption(l.md.backlog),
 			connector.UDPConnTTLBindOption(l.md.ttl),
 			connector.UDPDataBufferSizeBindOption(l.md.readBufferSize),

pkg/resolver/exchanger/exchanger.go

@@ -18,7 +18,7 @@ import (
 )
 
 type Options struct {
-	chain     *chain.Chain
+	router    *chain.Router
 	tlsConfig *tls.Config
 	timeout   time.Duration
 	logger    logger.Logger
@@ -27,10 +27,10 @@ type Options struct {
 // Option allows a common way to set Exchanger options.
 type Option func(opts *Options)
 
-// ChainOption sets the chain for Exchanger.
+// RouterOption sets the router for Exchanger.
-func ChainOption(chain *chain.Chain) Option {
+func RouterOption(router *chain.Router) Option {
 	return func(opts *Options) {
-		opts.chain = chain
+		opts.router = router
 	}
 }
 
@@ -89,14 +89,17 @@ func NewExchanger(addr string, opts ...Option) (Exchanger, error) {
 		network: u.Scheme,
 		addr:    u.Host,
 		rawAddr: addr,
+		router:  options.router,
 		options: options,
 	}
-	ex.router = (&chain.Router{}).
-		WithChain(options.chain).
-		WithLogger(options.logger)
 	if _, port, _ := net.SplitHostPort(ex.addr); port == "" {
 		ex.addr = net.JoinHostPort(ex.addr, "53")
 	}
+	if ex.router == nil {
+		ex.router = &chain.Router{
+			Logger: options.logger,
+		}
+	}
 
 	switch ex.network {
 	case "tcp":