strategy: add checktimeout config. (#89)

README.md

@@ -116,9 +116,11 @@ glider -config CONFIGPATH -listen :8080 -verbose
 ## Usage
 
 ```bash
-glider v0.6.10 usage:
+glider v0.7.0 usage:
   -checkinterval int
         proxy check interval(seconds) (default 30)
+  -checktimeout int
+        proxy check timeout(seconds) (default 10)
   -checkwebsite string
         proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80 (default "www.apple.com")
   -config string
@@ -139,6 +141,8 @@ glider v0.6.10 usage:
         timeout value used in multiple dnsservers switch(seconds) (default 3)
   -forward value
         forward url, format: SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS[,SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS]
+  -include value
+        include file
   -interface string
         source ip or source interface
   -listen value

common/conn/conn.go

@@ -7,41 +7,35 @@ import (
 	"time"
 )
 
-// UDPBufSize is the size of udp buffer
+// UDPBufSize is the size of udp buffer.
 const UDPBufSize = 65536
 
-// Conn struct
+// Conn is a base conn struct.
 type Conn struct {
 	r *bufio.Reader
 	net.Conn
 }
 
-// NewConn .
+// NewConn returns a new conn.
 func NewConn(c net.Conn) *Conn {
 	return &Conn{bufio.NewReader(c), c}
 }
 
-// NewConnSize .
+// Peek returns the next n bytes without advancing the reader.
-func NewConnSize(c net.Conn, n int) *Conn {
-	return &Conn{bufio.NewReaderSize(c, n), c}
-}
-
-// Peek .
 func (c *Conn) Peek(n int) ([]byte, error) {
 	return c.r.Peek(n)
 }
 
-// Read .
 func (c *Conn) Read(p []byte) (int, error) {
 	return c.r.Read(p)
 }
 
-// Reader returns the internal bufio.Reader
+// Reader returns the internal bufio.Reader.
 func (c *Conn) Reader() *bufio.Reader {
 	return c.r
 }
 
-// Relay .
+// Relay relays between left and right.
 func Relay(left, right net.Conn) (int64, int64, error) {
 	type res struct {
 		N   int64
@@ -67,8 +61,8 @@ func Relay(left, right net.Conn) (int64, int64, error) {
 	return n, rs.N, err
 }
 
-// TimedCopy copy from src to dst at target with read timeout
+// RelayUDP copys from src to dst at target with read timeout.
-func TimedCopy(dst net.PacketConn, target net.Addr, src net.PacketConn, timeout time.Duration) error {
+func RelayUDP(dst net.PacketConn, target net.Addr, src net.PacketConn, timeout time.Duration) error {
 	buf := make([]byte, UDPBufSize)
 	for {
 		src.SetReadDeadline(time.Now().Add(timeout))
@@ -84,7 +78,7 @@ func TimedCopy(dst net.PacketConn, target net.Addr, src net.PacketConn, timeout
 	}
 }
 
-// OutboundIP returns preferred outbound ip of this machine
+// OutboundIP returns preferred outbound ip of this machine.
 func OutboundIP() string {
 	conn, err := net.Dial("udp", "8.8.8.8:80")
 	if err != nil {

conf.go

@@ -40,6 +40,7 @@ func confInit() {
 	flag.StringVar(&conf.StrategyConfig.Strategy, "strategy", "rr", "forward strategy, default: rr")
 	flag.StringVar(&conf.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
 	flag.IntVar(&conf.StrategyConfig.CheckInterval, "checkinterval", 30, "proxy check interval(seconds)")
+	flag.IntVar(&conf.StrategyConfig.CheckTimeout, "checktimeout", 10, "proxy check timeout(seconds)")
 	flag.IntVar(&conf.StrategyConfig.MaxFailures, "maxfailures", 3, "max failures to change forwarder status to disabled")
 	flag.StringVar(&conf.StrategyConfig.IntFace, "interface", "", "source ip or source interface")
 

config/glider.conf.example

@@ -155,6 +155,8 @@ checkwebsite=www.apple.com
 # check interval(seconds)
 checkinterval=30
 
+# check timeout(seconds)
+checktimeout=10
 
 # DNS FORWARDING SERVER
 # ----------------

go.mod

@@ -19,9 +19,9 @@ require (
 	github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b // indirect
 	github.com/tjfoc/gmsm v1.0.1 // indirect
 	github.com/xtaci/kcp-go v5.0.7+incompatible
-	golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2
+	golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a
-	golang.org/x/net v0.0.0-20190311183353-d8887717615a // indirect
+	golang.org/x/net v0.0.0-20190313220215-9f648a60d977 // indirect
-	golang.org/x/sys v0.0.0-20190312061237-fead79001313 // indirect
+	golang.org/x/sys v0.0.0-20190316082340-a2f829d7f35f // indirect
 )
 
 // Replace dependency modules with local developing copy

go.sum

@@ -38,6 +38,8 @@ golang.org/x/crypto v0.0.0-20190228161510-8dd112bcdc25 h1:jsG6UpNLt9iAsb0S2AGW28
 golang.org/x/crypto v0.0.0-20190228161510-8dd112bcdc25/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a h1:YX8ljsm6wXlHZO+aRz9Exqr0evNhKRNe5K/gi+zKh4U=
+golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95 h1:fY7Dsw114eJN4boqzVSbpVHO6rTdhq6/GnXeu+PKnzU=
 golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190310074541-c10a0554eabf h1:J7RqX9u0J9ZB37CGaFc2VC+QZZT6E6jnDbrboEFVo0U=
@@ -46,6 +48,8 @@ golang.org/x/net v0.0.0-20190311031020-56fb01167e7d h1:vQJbQvu6+H699vOmHa20TEBI9
 golang.org/x/net v0.0.0-20190311031020-56fb01167e7d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190313220215-9f648a60d977 h1:actzWV6iWn3GLqN8dZjzsB+CLt+gaV2+wsxroxiQI8I=
+golang.org/x/net v0.0.0-20190313220215-9f648a60d977/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190302025703-b6889370fb10 h1:xQJI9OEiErEQ++DoXOHqEpzsGMrAv2Q2jyCpi7DmfpQ=
 golang.org/x/sys v0.0.0-20190302025703-b6889370fb10/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -69,4 +73,6 @@ golang.org/x/sys v0.0.0-20190311152110-c8c8c57fd1e1 h1:FQNj2xvjQ1lgFyzbSybGZr792
 golang.org/x/sys v0.0.0-20190311152110-c8c8c57fd1e1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190312061237-fead79001313 h1:pczuHS43Cp2ktBEEmLwScxgjWsBSzdaQiKzUyf3DTTc=
 golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190316082340-a2f829d7f35f h1:yCrMx/EeIue0+Qca57bWZS7VX6ymEoypmhWyPhz0NHM=
+golang.org/x/sys v0.0.0-20190316082340-a2f829d7f35f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

proxy/socks5/socks5.go

@@ -26,10 +26,10 @@ import (
 	"github.com/nadoo/glider/proxy"
 )
 
-// Version is socks5 version number
+// Version is socks5 version number.
 const Version = 5
 
-// SOCKS5 struct
+// SOCKS5 is a base socks5 struct.
 type SOCKS5 struct {
 	dialer   proxy.Dialer
 	addr     string
@@ -43,7 +43,7 @@ func init() {
 }
 
 // NewSOCKS5 returns a Proxy that makes SOCKS v5 connections to the given address
-// with an optional username and password. See RFC 1928
+// with an optional username and password. (RFC 1928)
 func NewSOCKS5(s string, dialer proxy.Dialer) (*SOCKS5, error) {
 	u, err := url.Parse(s)
 	if err != nil {
@@ -65,23 +65,23 @@ func NewSOCKS5(s string, dialer proxy.Dialer) (*SOCKS5, error) {
 	return h, nil
 }
 
-// NewSocks5Dialer returns a socks5 proxy dialer
+// NewSocks5Dialer returns a socks5 proxy dialer.
 func NewSocks5Dialer(s string, dialer proxy.Dialer) (proxy.Dialer, error) {
 	return NewSOCKS5(s, dialer)
 }
 
-// NewSocks5Server returns a socks5 proxy server
+// NewSocks5Server returns a socks5 proxy server.
 func NewSocks5Server(s string, dialer proxy.Dialer) (proxy.Server, error) {
 	return NewSOCKS5(s, dialer)
 }
 
-// ListenAndServe serves socks5 requests
+// ListenAndServe serves socks5 requests.
 func (s *SOCKS5) ListenAndServe() {
 	go s.ListenAndServeUDP()
 	s.ListenAndServeTCP()
 }
 
-// ListenAndServeTCP .
+// ListenAndServeTCP listen and serve on tcp port.
 func (s *SOCKS5) ListenAndServeTCP() {
 	l, err := net.Listen("tcp", s.addr)
 	if err != nil {
@@ -102,7 +102,7 @@ func (s *SOCKS5) ListenAndServeTCP() {
 	}
 }
 
-// Serve .
+// Serve serves a connection.
 func (s *SOCKS5) Serve(c net.Conn) {
 	defer c.Close()
 
@@ -148,7 +148,7 @@ func (s *SOCKS5) Serve(c net.Conn) {
 	}
 }
 
-// ListenAndServeUDP serves udp requests
+// ListenAndServeUDP serves udp requests.
 func (s *SOCKS5) ListenAndServeUDP() {
 	lc, err := net.ListenPacket("udp", s.addr)
 	if err != nil {
@@ -189,7 +189,7 @@ func (s *SOCKS5) ListenAndServeUDP() {
 			nm.Store(raddr.String(), pc)
 
 			go func() {
-				conn.TimedCopy(c, raddr, pc, 2*time.Minute)
+				conn.RelayUDP(c, raddr, pc, 2*time.Minute)
 				pc.Close()
 				nm.Delete(raddr.String())
 			}()
@@ -211,7 +211,7 @@ func (s *SOCKS5) ListenAndServeUDP() {
 
 }
 
-// Addr returns forwarder's address
+// Addr returns forwarder's address.
 func (s *SOCKS5) Addr() string {
 	if s.addr == "" {
 		return s.dialer.Addr()
@@ -219,7 +219,7 @@ func (s *SOCKS5) Addr() string {
 	return s.addr
 }
 
-// NextDialer returns the next dialer
+// NextDialer returns the next dialer.
 func (s *SOCKS5) NextDialer(dstAddr string) proxy.Dialer { return s.dialer.NextDialer(dstAddr) }
 
 // Dial connects to the address addr on the network net via the SOCKS5 proxy.
@@ -244,7 +244,7 @@ func (s *SOCKS5) Dial(network, addr string) (net.Conn, error) {
 	return c, nil
 }
 
-// DialUDP connects to the given address via the proxy
+// DialUDP connects to the given address via the proxy.
 func (s *SOCKS5) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
 	c, err := s.dialer.Dial("tcp", s.addr)
 	if err != nil {
@@ -293,7 +293,7 @@ func (s *SOCKS5) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.A
 
 // connect takes an existing connection to a socks5 proxy server,
 // and commands the server to extend that connection to target,
-// which must be a canonical address with a host and port
+// which must be a canonical address with a host and port.
 func (s *SOCKS5) connect(conn net.Conn, target string) error {
 	host, portStr, err := net.SplitHostPort(target)
 	if err != nil {
@@ -424,7 +424,7 @@ func (s *SOCKS5) connect(conn net.Conn, target string) error {
 	return nil
 }
 
-// Handshake fast-tracks SOCKS initialization to get target address to connect
+// Handshake fast-tracks SOCKS initialization to get target address to connect.
 func (s *SOCKS5) handshake(rw io.ReadWriter) (socks.Addr, error) {
 	// Read RFC 1928 for request and reply structure and sizes
 	buf := make([]byte, socks.MaxAddrLen)

proxy/ss/ss.go

@@ -16,7 +16,7 @@ import (
 	"github.com/nadoo/glider/proxy"
 )
 
-// SS .
+// SS is a base ss struct.
 type SS struct {
 	dialer proxy.Dialer
 	addr   string
@@ -29,7 +29,7 @@ func init() {
 	proxy.RegisterServer("ss", NewSSServer)
 }
 
-// NewSS returns a shadowsocks proxy
+// NewSS returns a ss proxy.
 func NewSS(s string, dialer proxy.Dialer) (*SS, error) {
 	u, err := url.Parse(s)
 	if err != nil {
@@ -55,23 +55,23 @@ func NewSS(s string, dialer proxy.Dialer) (*SS, error) {
 	return p, nil
 }
 
-// NewSSDialer returns a ss proxy dialer
+// NewSSDialer returns a ss proxy dialer.
 func NewSSDialer(s string, dialer proxy.Dialer) (proxy.Dialer, error) {
 	return NewSS(s, dialer)
 }
 
-// NewSSServer returns a ss proxy server
+// NewSSServer returns a ss proxy server.
 func NewSSServer(s string, dialer proxy.Dialer) (proxy.Server, error) {
 	return NewSS(s, dialer)
 }
 
-// ListenAndServe serves ss requests
+// ListenAndServe serves ss requests.
 func (s *SS) ListenAndServe() {
 	go s.ListenAndServeUDP()
 	s.ListenAndServeTCP()
 }
 
-// ListenAndServeTCP serves tcp ss requests
+// ListenAndServeTCP serves tcp ss requests.
 func (s *SS) ListenAndServeTCP() {
 	l, err := net.Listen("tcp", s.addr)
 	if err != nil {
@@ -92,7 +92,7 @@ func (s *SS) ListenAndServeTCP() {
 
 }
 
-// Serve serves tcp ss requests
+// Serve serves a connection.
 func (s *SS) Serve(c net.Conn) {
 	defer c.Close()
 
@@ -166,7 +166,7 @@ func (s *SS) Serve(c net.Conn) {
 
 }
 
-// ListenAndServeUDP serves udp ss requests
+// ListenAndServeUDP serves udp ss requests.
 func (s *SS) ListenAndServeUDP() {
 	lc, err := net.ListenPacket("udp", s.addr)
 	if err != nil {
@@ -204,7 +204,7 @@ func (s *SS) ListenAndServeUDP() {
 			nm.Store(raddr.String(), pc)
 
 			go func() {
-				conn.TimedCopy(c, raddr, pc, 2*time.Minute)
+				conn.RelayUDP(c, raddr, pc, 2*time.Minute)
 				pc.Close()
 				nm.Delete(raddr.String())
 			}()
@@ -225,12 +225,12 @@ func (s *SS) ListenAndServeUDP() {
 	}
 }
 
-// ListCipher .
+// ListCipher returns all the ciphers supported.
 func ListCipher() string {
 	return strings.Join(core.ListCipher(), " ")
 }
 
-// Addr returns forwarder's address
+// Addr returns forwarder's address.
 func (s *SS) Addr() string {
 	if s.addr == "" {
 		return s.dialer.Addr()
@@ -238,7 +238,7 @@ func (s *SS) Addr() string {
 	return s.addr
 }
 
-// NextDialer returns the next dialer
+// NextDialer returns the next dialer.
 func (s *SS) NextDialer(dstAddr string) proxy.Dialer { return s.dialer.NextDialer(dstAddr) }
 
 // Dial connects to the address addr on the network net via the proxy.
@@ -268,7 +268,7 @@ func (s *SS) Dial(network, addr string) (net.Conn, error) {
 
 }
 
-// DialUDP connects to the given address via the proxy
+// DialUDP connects to the given address via the proxy.
 func (s *SS) DialUDP(network, addr string) (net.PacketConn, net.Addr, error) {
 	pc, nextHop, err := s.dialer.DialUDP(network, s.addr)
 	if err != nil {

proxy/udptun/udptun.go

@@ -16,8 +16,8 @@ import (
 type UDPTun struct {
 	dialer proxy.Dialer
 	addr   string
-	taddr  string       // tunnel addr
+	taddr  string       // tunnel addr string
-	uaddr  *net.UDPAddr // tunnel addr
+	tuaddr *net.UDPAddr // tunnel addr
 }
 
 func init() {
@@ -41,7 +41,7 @@ func NewUDPTun(s string, dialer proxy.Dialer) (*UDPTun, error) {
 		taddr:  d[1],
 	}
 
-	p.uaddr, err = net.ResolveUDPAddr("udp", p.taddr)
+	p.tuaddr, err = net.ResolveUDPAddr("udp", p.taddr)
 	return p, err
 }
 
@@ -85,7 +85,7 @@ func (s *UDPTun) ListenAndServe() {
 			nm.Store(raddr.String(), pc)
 
 			go func() {
-				conn.TimedCopy(c, raddr, pc, 2*time.Minute)
+				conn.RelayUDP(c, raddr, pc, 2*time.Minute)
 				pc.Close()
 				nm.Delete(raddr.String())
 			}()
@@ -94,7 +94,7 @@ func (s *UDPTun) ListenAndServe() {
 			pc = v.(net.PacketConn)
 		}
 
-		_, err = pc.WriteTo(buf[:n], s.uaddr)
+		_, err = pc.WriteTo(buf[:n], s.tuaddr)
 		if err != nil {
 			log.F("[udptun] remote write error: %v", err)
 			continue

proxy/uottun/uottun.go

@@ -12,7 +12,7 @@ import (
 	"github.com/nadoo/glider/proxy"
 )
 
-// UoTTun udp over tcp tunnel
+// UoTTun is a base udp over tcp tunnel struct.
 type UoTTun struct {
 	dialer proxy.Dialer
 	addr   string
@@ -24,7 +24,7 @@ func init() {
 	proxy.RegisterServer("uottun", NewUoTTunServer)
 }
 
-// NewUoTTun returns a UoTTun proxy
+// NewUoTTun returns a UoTTun proxy.
 func NewUoTTun(s string, dialer proxy.Dialer) (*UoTTun, error) {
 	u, err := url.Parse(s)
 	if err != nil {
@@ -44,12 +44,12 @@ func NewUoTTun(s string, dialer proxy.Dialer) (*UoTTun, error) {
 	return p, nil
 }
 
-// NewUoTTunServer returns a uot tunnel server
+// NewUoTTunServer returns a uot tunnel server.
 func NewUoTTunServer(s string, dialer proxy.Dialer) (proxy.Server, error) {
 	return NewUoTTun(s, dialer)
 }
 
-// ListenAndServe .
+// ListenAndServe listen and serve on tcp.
 func (s *UoTTun) ListenAndServe() {
 	c, err := net.ListenPacket("udp", s.addr)
 	if err != nil {
@@ -78,7 +78,7 @@ func (s *UoTTun) ListenAndServe() {
 		go func() {
 			// no remote forwarder, just a local udp forwarder
 			if urc, ok := rc.(*net.UDPConn); ok {
-				conn.TimedCopy(c, clientAddr, urc, 2*time.Minute)
+				conn.RelayUDP(c, clientAddr, urc, 2*time.Minute)
 				urc.Close()
 				return
 			}
@@ -103,7 +103,7 @@ func (s *UoTTun) ListenAndServe() {
 	}
 }
 
-// Serve .
+// Serve is not allowed to be called directly.
 func (s *UoTTun) Serve(c net.Conn) {
 	// TODO
 	log.F("[uottun] func Serve: can not be called directly")

rule/config.go

@@ -35,6 +35,7 @@ func NewConfFromFile(ruleFile string) (*Config, error) {
 	f.StringVar(&p.StrategyConfig.Strategy, "strategy", "rr", "forward strategy, default: rr")
 	f.StringVar(&p.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
 	f.IntVar(&p.StrategyConfig.CheckInterval, "checkinterval", 30, "proxy check interval(seconds)")
+	f.IntVar(&p.StrategyConfig.CheckTimeout, "checktimeout", 10, "proxy check timeout(seconds)")
 	f.StringVar(&p.StrategyConfig.IntFace, "interface", "", "source ip or source interface")
 
 	f.StringSliceUniqVar(&p.DNSServers, "dnsserver", nil, "remote dns server")

strategy/strategy.go

@@ -15,16 +15,17 @@ import (
 	"github.com/nadoo/glider/proxy"
 )
 
-// Checker is an interface of forwarder checker
+// Checker is an interface of forwarder checker.
 type Checker interface {
 	Check()
 }
 
-// Config of strategy
+// Config is strategy config struct.
 type Config struct {
 	Strategy      string
 	CheckWebSite  string
 	CheckInterval int
+	CheckTimeout  int
 	MaxFailures   int
 	IntFace       string
 }
@@ -36,7 +37,7 @@ func (p priSlice) Len() int           { return len(p) }
 func (p priSlice) Less(i, j int) bool { return p[i].Priority() > p[j].Priority() }
 func (p priSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
 
-// Dialer .
+// Dialer is base dialer struct.
 type Dialer struct {
 	config    *Config
 	fwdrs     priSlice
@@ -48,7 +49,7 @@ type Dialer struct {
 	nextForwarder func(addr string) *proxy.Forwarder
 }
 
-// NewDialer returns a new strategy dialer
+// NewDialer returns a new strategy dialer.
 func NewDialer(s []string, c *Config) proxy.Dialer {
 	var fwdrs []*proxy.Forwarder
 	for _, chain := range s {
@@ -111,20 +112,20 @@ func newDialer(fwdrs []*proxy.Forwarder, c *Config) *Dialer {
 	return d
 }
 
-// Addr returns forwarder's address
+// Addr returns forwarder's address.
 func (d *Dialer) Addr() string { return "STRATEGY" }
 
-// Dial connects to the address addr on the network net
+// Dial connects to the address addr on the network net.
 func (d *Dialer) Dial(network, addr string) (net.Conn, error) {
 	return d.NextDialer(addr).Dial(network, addr)
 }
 
-// DialUDP connects to the given address
+// DialUDP connects to the given address.
 func (d *Dialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
 	return d.NextDialer(addr).DialUDP(network, addr)
 }
 
-// NextDialer returns the next dialer
+// NextDialer returns the next dialer.
 func (d *Dialer) NextDialer(dstAddr string) proxy.Dialer {
 	d.mu.RLock()
 	defer d.mu.RUnlock()
@@ -132,13 +133,13 @@ func (d *Dialer) NextDialer(dstAddr string) proxy.Dialer {
 	return d.nextForwarder(dstAddr)
 }
 
-// Priority returns the active priority of dialer
+// Priority returns the active priority of dialer.
 func (d *Dialer) Priority() uint32 { return atomic.LoadUint32(&d.priority) }
 
-// SetPriority sets the active priority of daler
+// SetPriority sets the active priority of daler.
 func (d *Dialer) SetPriority(p uint32) { atomic.StoreUint32(&d.priority, p) }
 
-// initAvailable traverse d.fwdrs and init the available forwarder slice
+// initAvailable traverse d.fwdrs and init the available forwarder slice.
 func (d *Dialer) initAvailable() {
 	for _, f := range d.fwdrs {
 		if f.Enabled() {
@@ -162,7 +163,7 @@ func (d *Dialer) initAvailable() {
 	}
 }
 
-// onStatusChanged will be called when fwdr's status changed
+// onStatusChanged will be called when fwdr's status changed.
 func (d *Dialer) onStatusChanged(fwdr *proxy.Forwarder) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
@@ -189,7 +190,7 @@ func (d *Dialer) onStatusChanged(fwdr *proxy.Forwarder) {
 	}
 }
 
-// Check implements the Checker interface
+// Check implements the Checker interface.
 func (d *Dialer) Check() {
 	for i := 0; i < len(d.fwdrs); i++ {
 		go d.check(i)
@@ -229,11 +230,19 @@ func (d *Dialer) check(i int) {
 			f.Disable()
 			log.F("[check] %s(%d) -> %s, DISABLED. error in read: %s", f.Addr(), f.Priority(), d.config.CheckWebSite, err)
 		} else if bytes.Equal([]byte("HTTP"), buf) {
-			f.Enable()
+
-			retry = 2
 			readTime := time.Since(startTime)
 			f.SetLatency(int64(readTime))
-			log.F("[check] %s(%d) -> %s, ENABLED. connect time: %s", f.Addr(), f.Priority(), d.config.CheckWebSite, readTime.String())
+
+			if readTime > time.Duration(d.config.CheckTimeout)*time.Second {
+				f.Disable()
+				log.F("[check] %s(%d) -> %s, DISABLED. connect timeout: %s", f.Addr(), f.Priority(), d.config.CheckWebSite, readTime)
+			} else {
+				retry = 2
+				f.Enable()
+				log.F("[check] %s(%d) -> %s, ENABLED. connect time: %s", f.Addr(), f.Priority(), d.config.CheckWebSite, readTime)
+			}
+
 		} else {
 			f.Disable()
 			log.F("[check] %s(%d) -> %s, DISABLED. server response: %s", f.Addr(), f.Priority(), d.config.CheckWebSite, buf)