add Handler.Init

chain.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"time"
 
 	"github.com/go-log/log"
 )
@@ -308,3 +309,42 @@ func (c *Chain) selectRouteFor(addr string) (route *Chain, err error) {
 	}
 	return
 }
+
+// ChainOptions holds options for Chain.
+type ChainOptions struct {
+	Retry    int
+	Timeout  time.Duration
+	Hosts    *Hosts
+	Resolver Resolver
+}
+
+// ChainOption allows a common way to set chain options.
+type ChainOption func(opts *ChainOptions)
+
+// RetryChainOption specifies the times of retry used by Chain.Dial.
+func RetryChainOption(retry int) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Retry = retry
+	}
+}
+
+// TimeoutChainOption specifies the timeout used by Chain.Dial.
+func TimeoutChainOption(timeout time.Duration) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Timeout = timeout
+	}
+}
+
+// HostsChainOption specifies the hosts used by Chain.Dial.
+func HostsChainOption(hosts *Hosts) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Hosts = hosts
+	}
+}
+
+// ResolverChainOption specifies the Resolver used by Chain.Dial.
+func ResolverChainOption(resolver Resolver) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Resolver = resolver
+	}
+}

client.go

@@ -90,7 +90,7 @@ func (tr *tcpTransporter) Multiplex() bool {
 	return false
 }
 
-// DialOptions describes the options for dialing.
+// DialOptions describes the options for Transporter.Dial.
 type DialOptions struct {
 	Timeout time.Duration
 	Chain   *Chain

cmd/gost/main.go

@@ -341,15 +341,12 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 }
 
 func (r *route) serve() error {
-	baseChain, err := r.initChain()
+	chain, err := r.initChain()
 	if err != nil {
 		return err
 	}
 
 	for _, ns := range r.ServeNodes {
-		chain := &gost.Chain{}
-		*chain = *baseChain
-
 		node, err := gost.ParseNode(ns)
 		if err != nil {
 			return err
@@ -469,8 +466,43 @@ func (r *route) serve() error {
 			}
 		}
 
-		var handlerOptions []gost.HandlerOption
-		handlerOptions = append(handlerOptions,
+		var handler gost.Handler
+		switch node.Protocol {
+		case "http2":
+			handler = gost.HTTP2Handler()
+		case "socks", "socks5":
+			handler = gost.SOCKS5Handler()
+		case "socks4", "socks4a":
+			handler = gost.SOCKS4Handler()
+		case "ss":
+			handler = gost.ShadowHandler()
+		case "http":
+			handler = gost.HTTPHandler()
+		case "tcp":
+			handler = gost.TCPDirectForwardHandler(node.Remote)
+		case "rtcp":
+			handler = gost.TCPRemoteForwardHandler(node.Remote)
+		case "udp":
+			handler = gost.UDPDirectForwardHandler(node.Remote)
+		case "rudp":
+			handler = gost.UDPRemoteForwardHandler(node.Remote)
+		case "forward":
+			handler = gost.SSHForwardHandler()
+		case "redirect":
+			handler = gost.TCPRedirectHandler()
+		case "ssu":
+			handler = gost.ShadowUDPdHandler()
+		case "sni":
+			handler = gost.SNIHandler()
+		default:
+			// start from 2.5, if remote is not empty, then we assume that it is a forward tunnel.
+			if node.Remote != "" {
+				handler = gost.TCPDirectForwardHandler(node.Remote)
+			} else {
+				handler = gost.AutoHandler()
+			}
+		}
+		handler.Init(
 			gost.AddrHandlerOption(node.Addr),
 			gost.ChainHandlerOption(chain),
 			gost.UsersHandlerOption(users...),
@@ -480,44 +512,6 @@ func (r *route) serve() error {
 			gost.BypassHandlerOption(parseBypass(node.Get("bypass"))),
 			gost.StrategyHandlerOption(parseStrategy(node.Get("strategy"))),
 		)
-		var handler gost.Handler
-		switch node.Protocol {
-		case "http2":
-			handler = gost.HTTP2Handler(handlerOptions...)
-		case "socks", "socks5":
-			handler = gost.SOCKS5Handler(handlerOptions...)
-		case "socks4", "socks4a":
-			handler = gost.SOCKS4Handler(handlerOptions...)
-		case "ss":
-			handler = gost.ShadowHandler(handlerOptions...)
-		case "http":
-			handler = gost.HTTPHandler(handlerOptions...)
-		case "tcp":
-			handler = gost.TCPDirectForwardHandler(node.Remote, handlerOptions...)
-		case "rtcp":
-			handler = gost.TCPRemoteForwardHandler(node.Remote, handlerOptions...)
-		case "udp":
-			handler = gost.UDPDirectForwardHandler(node.Remote, handlerOptions...)
-		case "rudp":
-			handler = gost.UDPRemoteForwardHandler(node.Remote, handlerOptions...)
-		case "forward":
-			handler = gost.SSHForwardHandler(handlerOptions...)
-		case "redirect":
-			handler = gost.TCPRedirectHandler(handlerOptions...)
-		case "ssu":
-			handler = gost.ShadowUDPdHandler(handlerOptions...)
-		case "sni":
-			handler = gost.SNIHandler(handlerOptions...)
-		default:
-			// start from 2.5, if remote is not empty, then we assume that it is a forward tunnel.
-			if node.Remote != "" {
-				handler = gost.TCPDirectForwardHandler(node.Remote, handlerOptions...)
-			} else {
-				handler = gost.AutoHandler(handlerOptions...)
-			}
-		}
-
-		srv := &gost.Server{Listener: ln}
 
 		chain.Resolver = parseResolver(node.Get("dns"))
 		if gost.Debug {
@@ -531,6 +525,7 @@ func (r *route) serve() error {
 			}
 		}
 
+		srv := &gost.Server{Listener: ln}
 		go srv.Serve(handler)
 	}
 

forward.go

@@ -38,20 +38,8 @@ type tcpDirectForwardHandler struct {
 func TCPDirectForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &tcpDirectForwardHandler{
 		raddr: raddr,
-		options: &HandlerOptions{},
+		group: NewNodeGroup(),
 	}
-	for _, opt := range opts {
-		opt(h.options)
-	}
-
-	group := NewNodeGroup()
-	group.SetSelector(&defaultSelector{},
-		WithStrategy(h.options.Strategy),
-		WithFilter(&FailFilter{
-			MaxFails:    1,
-			FailTimeout: 30 * time.Second,
-		}),
-	)
 
 	for i, addr := range strings.Split(raddr, ",") {
 		if addr == "" {
@@ -59,17 +47,35 @@ func TCPDirectForwardHandler(raddr string, opts ...HandlerOption) Handler {
 		}
 		// We treat the remote target server as a node, so we can put them in a group,
 		// and perform the node selection for load balancing.
-		group.AddNode(Node{
+		h.group.AddNode(Node{
 			ID:   i + 1,
 			Addr: addr,
 			Host: addr,
 		})
 	}
-	h.group = group
+	h.Init(opts...)
 
 	return h
 }
 
+func (h *tcpDirectForwardHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
+		opt(h.options)
+	}
+
+	h.group.SetSelector(&defaultSelector{},
+		WithStrategy(h.options.Strategy),
+		WithFilter(&FailFilter{
+			MaxFails:    1,
+			FailTimeout: 30 * time.Second,
+		}),
+	)
+}
+
 func (h *tcpDirectForwardHandler) Handle(conn net.Conn) {
 	defer conn.Close()
 
@@ -107,20 +113,8 @@ type udpDirectForwardHandler struct {
 func UDPDirectForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &udpDirectForwardHandler{
 		raddr: raddr,
-		options: &HandlerOptions{},
+		group: NewNodeGroup(),
 	}
-	for _, opt := range opts {
-		opt(h.options)
-	}
-
-	group := NewNodeGroup()
-	group.SetSelector(&defaultSelector{},
-		WithStrategy(h.options.Strategy),
-		WithFilter(&FailFilter{
-			MaxFails:    1,
-			FailTimeout: 30 * time.Second,
-		}),
-	)
 
 	for i, addr := range strings.Split(raddr, ",") {
 		if addr == "" {
@@ -128,17 +122,36 @@ func UDPDirectForwardHandler(raddr string, opts ...HandlerOption) Handler {
 		}
 		// We treat the remote target server as a node, so we can put them in a group,
 		// and perform the node selection for load balancing.
-		group.AddNode(Node{
+		h.group.AddNode(Node{
 			ID:   i + 1,
 			Addr: addr,
 			Host: addr,
 		})
 	}
-	h.group = group
+
+	h.Init(opts...)
 
 	return h
 }
 
+func (h *udpDirectForwardHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
+		opt(h.options)
+	}
+
+	h.group.SetSelector(&defaultSelector{},
+		WithStrategy(h.options.Strategy),
+		WithFilter(&FailFilter{
+			MaxFails:    1,
+			FailTimeout: 30 * time.Second,
+		}),
+	)
+}
+
 func (h *udpDirectForwardHandler) Handle(conn net.Conn) {
 	defer conn.Close()
 
@@ -192,20 +205,8 @@ type tcpRemoteForwardHandler struct {
 func TCPRemoteForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &tcpRemoteForwardHandler{
 		raddr: raddr,
-		options: &HandlerOptions{},
+		group: NewNodeGroup(),
 	}
-	for _, opt := range opts {
-		opt(h.options)
-	}
-
-	group := NewNodeGroup()
-	group.SetSelector(&defaultSelector{},
-		WithStrategy(h.options.Strategy),
-		WithFilter(&FailFilter{
-			MaxFails:    1,
-			FailTimeout: 30 * time.Second,
-		}),
-	)
 
 	for i, addr := range strings.Split(raddr, ",") {
 		if addr == "" {
@@ -213,17 +214,34 @@ func TCPRemoteForwardHandler(raddr string, opts ...HandlerOption) Handler {
 		}
 		// We treat the remote target server as a node, so we can put them in a group,
 		// and perform the node selection for load balancing.
-		group.AddNode(Node{
+		h.group.AddNode(Node{
 			ID:   i + 1,
 			Addr: addr,
 			Host: addr,
 		})
 	}
-	h.group = group
+	h.Init(opts...)
 
 	return h
 }
 
+func (h *tcpRemoteForwardHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+	for _, opt := range options {
+		opt(h.options)
+	}
+
+	h.group.SetSelector(&defaultSelector{},
+		WithStrategy(h.options.Strategy),
+		WithFilter(&FailFilter{
+			MaxFails:    1,
+			FailTimeout: 30 * time.Second,
+		}),
+	)
+}
+
 func (h *tcpRemoteForwardHandler) Handle(conn net.Conn) {
 	defer conn.Close()
 
@@ -259,37 +277,44 @@ type udpRemoteForwardHandler struct {
 func UDPRemoteForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &udpRemoteForwardHandler{
 		raddr: raddr,
-		options: &HandlerOptions{},
-	}
-	for _, opt := range opts {
-		opt(h.options)
+		group: NewNodeGroup(),
 	}
 
-	group := NewNodeGroup()
-	group.SetSelector(&defaultSelector{},
-		WithStrategy(h.options.Strategy),
-		WithFilter(&FailFilter{
-			MaxFails:    1,
-			FailTimeout: 30 * time.Second,
-		}),
-	)
 	for i, addr := range strings.Split(raddr, ",") {
 		if addr == "" {
 			continue
 		}
 		// We treat the remote target server as a node, so we can put them in a group,
 		// and perform the node selection for load balancing.
-		group.AddNode(Node{
+		h.group.AddNode(Node{
 			ID:   i + 1,
 			Addr: addr,
 			Host: addr,
 		})
 	}
-	h.group = group
+
+	h.Init(opts...)
 
 	return h
 }
 
+func (h *udpRemoteForwardHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
+		opt(h.options)
+	}
+	h.group.SetSelector(&defaultSelector{},
+		WithStrategy(h.options.Strategy),
+		WithFilter(&FailFilter{
+			MaxFails:    1,
+			FailTimeout: 30 * time.Second,
+		}),
+	)
+}
+
 func (h *udpRemoteForwardHandler) Handle(conn net.Conn) {
 	defer conn.Close()
 

handler.go

@@ -13,6 +13,7 @@ import (
 
 // Handler is a proxy server handler
 type Handler interface {
+	Init(options ...HandlerOption)
 	Handle(net.Conn)
 }
 
@@ -88,17 +89,25 @@ func StrategyHandlerOption(strategy Strategy) HandlerOption {
 }
 
 type autoHandler struct {
-	options []HandlerOption
+	options *HandlerOptions
 }
 
 // AutoHandler creates a server Handler for auto proxy server.
 func AutoHandler(opts ...HandlerOption) Handler {
-	h := &autoHandler{
-		options: opts,
-	}
+	h := &autoHandler{}
+	h.Init(opts...)
 	return h
 }
 
+func (h *autoHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+	for _, opt := range options {
+		opt(h.options)
+	}
+}
+
 func (h *autoHandler) Handle(conn net.Conn) {
 	br := bufio.NewReader(conn)
 	b, err := br.Peek(1)
@@ -109,25 +118,23 @@ func (h *autoHandler) Handle(conn net.Conn) {
 	}
 
 	cc := &bufferdConn{Conn: conn, br: br}
+	var handler Handler
 	switch b[0] {
 	case gosocks4.Ver4:
-		options := &HandlerOptions{}
-		for _, opt := range h.options {
-			opt(options)
-		}
 		// SOCKS4(a) does not suppport authentication method,
 		// so we ignore it when credentials are specified for security reason.
-		if len(options.Users) > 0 {
+		if len(h.options.Users) > 0 {
 			cc.Close()
 			return
 		}
-		h := &socks4Handler{options}
-		h.Handle(cc)
-	case gosocks5.Ver5:
-		SOCKS5Handler(h.options...).Handle(cc)
+		handler = &socks4Handler{options: h.options}
+	case gosocks5.Ver5: // socks5
+		handler = &socks5Handler{options: h.options}
 	default: // http
-		HTTPHandler(h.options...).Handle(cc)
+		handler = &httpHandler{options: h.options}
 	}
+	handler.Init()
+	handler.Handle(cc)
 }
 
 type bufferdConn struct {

http.go

@@ -75,13 +75,18 @@ type httpHandler struct {
 
 // HTTPHandler creates a server Handler for HTTP proxy server.
 func HTTPHandler(opts ...HandlerOption) Handler {
-	h := &httpHandler{
-		options: &HandlerOptions{},
+	h := &httpHandler{}
+	h.Init(opts...)
+	return h
 }
-	for _, opt := range opts {
+
+func (h *httpHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+	for _, opt := range options {
 		opt(h.options)
 	}
-	return h
 }
 
 func (h *httpHandler) Handle(conn net.Conn) {

http2.go

@@ -250,16 +250,21 @@ type http2Handler struct {
 
 // HTTP2Handler creates a server Handler for HTTP2 proxy server.
 func HTTP2Handler(opts ...HandlerOption) Handler {
-	h := &http2Handler{
-		options: new(HandlerOptions),
-	}
-	for _, opt := range opts {
-		opt(h.options)
-	}
+	h := &http2Handler{}
+	h.Init(opts...)
 
 	return h
 }
 
+func (h *http2Handler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+	for _, opt := range options {
+		opt(h.options)
+	}
+}
+
 func (h *http2Handler) Handle(conn net.Conn) {
 	defer conn.Close()
 

redirect.go

@@ -17,15 +17,20 @@ type tcpRedirectHandler struct {
 
 // TCPRedirectHandler creates a server Handler for TCP redirect server.
 func TCPRedirectHandler(opts ...HandlerOption) Handler {
-	h := &tcpRedirectHandler{
-		options: &HandlerOptions{
-			Chain: new(Chain),
-		},
+	h := &tcpRedirectHandler{}
+	h.Init(opts...)
+
+	return h
 }
-	for _, opt := range opts {
+
+func (h *tcpRedirectHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
 		opt(h.options)
 	}
-	return h
 }
 
 func (h *tcpRedirectHandler) Handle(c net.Conn) {

resolver.go

@@ -48,6 +48,12 @@ func (ns NameServer) String() string {
 	return fmt.Sprintf("%s/%s %s", addr, prot, host)
 }
 
+type nameServers struct {
+	Servers []NameServer
+	Timeout time.Duration
+	TTL     time.Duration
+}
+
 type resolverCacheItem struct {
 	IPs []net.IP
 	ts  int64

sni.go

@@ -38,13 +38,20 @@ type sniHandler struct {
 
 // SNIHandler creates a server Handler for SNI proxy server.
 func SNIHandler(opts ...HandlerOption) Handler {
-	h := &sniHandler{
-		options: &HandlerOptions{},
+	h := &sniHandler{}
+	h.Init(opts...)
+
+	return h
 }
-	for _, opt := range opts {
+
+func (h *sniHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
 		opt(h.options)
 	}
-	return h
 }
 
 func (h *sniHandler) Handle(conn net.Conn) {

socks.go

@@ -348,30 +348,36 @@ type socks5Handler struct {
 
 // SOCKS5Handler creates a server Handler for SOCKS5 proxy server.
 func SOCKS5Handler(opts ...HandlerOption) Handler {
-	options := &HandlerOptions{}
-	for _, opt := range opts {
-		opt(options)
+	h := &socks5Handler{}
+	h.Init(opts...)
+
+	return h
 }
 
-	tlsConfig := options.TLSConfig
+func (h *socks5Handler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
+		opt(h.options)
+	}
+
+	tlsConfig := h.options.TLSConfig
 	if tlsConfig == nil {
 		tlsConfig = DefaultTLSConfig
 	}
-	selector := &serverSelector{ // socks5 server selector
-		Users:     options.Users,
+	h.selector = &serverSelector{ // socks5 server selector
+		Users:     h.options.Users,
 		TLSConfig: tlsConfig,
 	}
 	// methods that socks5 server supported
-	selector.AddMethod(
+	h.selector.AddMethod(
 		gosocks5.MethodNoAuth,
 		gosocks5.MethodUserPass,
 		MethodTLS,
 		MethodTLSAuth,
 	)
-	return &socks5Handler{
-		options:  options,
-		selector: selector,
-	}
 }
 
 func (h *socks5Handler) Handle(conn net.Conn) {
@@ -1110,12 +1116,19 @@ type socks4Handler struct {
 
 // SOCKS4Handler creates a server Handler for SOCKS4(A) proxy server.
 func SOCKS4Handler(opts ...HandlerOption) Handler {
-	options := &HandlerOptions{}
-	for _, opt := range opts {
-		opt(options)
+	h := &socks4Handler{}
+	h.Init(opts...)
+
+	return h
 }
-	return &socks4Handler{
-		options: options,
+
+func (h *socks4Handler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
+		opt(h.options)
 	}
 }
 

ss.go

@@ -97,13 +97,20 @@ type shadowHandler struct {
 
 // ShadowHandler creates a server Handler for shadowsocks proxy server.
 func ShadowHandler(opts ...HandlerOption) Handler {
-	h := &shadowHandler{
-		options: &HandlerOptions{},
+	h := &shadowHandler{}
+	h.Init(opts...)
+
+	return h
 }
-	for _, opt := range opts {
+
+func (h *shadowHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
 		opt(h.options)
 	}
-	return h
 }
 
 func (h *shadowHandler) Handle(conn net.Conn) {
@@ -326,13 +333,20 @@ type shadowUDPdHandler struct {
 
 // ShadowUDPdHandler creates a server Handler for shadowsocks UDP relay server.
 func ShadowUDPdHandler(opts ...HandlerOption) Handler {
-	h := &shadowUDPdHandler{
-		options: &HandlerOptions{},
+	h := &shadowUDPdHandler{}
+	h.Init(opts...)
+
+	return h
 }
-	for _, opt := range opts {
+
+func (h *shadowUDPdHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
 		opt(h.options)
 	}
-	return h
 }
 
 func (h *shadowUDPdHandler) Handle(conn net.Conn) {

ssh.go

@@ -408,13 +408,22 @@ type sshForwardHandler struct {
 
 // SSHForwardHandler creates a server Handler for SSH port forwarding server.
 func SSHForwardHandler(opts ...HandlerOption) Handler {
-	h := &sshForwardHandler{
-		options: new(HandlerOptions),
-		config:  new(ssh.ServerConfig),
+	h := &sshForwardHandler{}
+	h.Init(opts...)
+
+	return h
 }
-	for _, opt := range opts {
+
+func (h *sshForwardHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+
+	for _, opt := range options {
 		opt(h.options)
 	}
+	h.config = &ssh.ServerConfig{}
+
 	h.config.PasswordCallback = defaultSSHPasswordCallback(h.options.Users...)
 	if len(h.options.Users) == 0 {
 		h.config.NoClientAuth = true
@@ -430,8 +439,6 @@ func SSHForwardHandler(opts ...HandlerOption) Handler {
 		}
 		h.config.AddHostKey(signer)
 	}
-
-	return h
 }
 
 func (h *sshForwardHandler) Handle(conn net.Conn) {