proxy: drop tcptun and udptun, use tcp and udp instead

README.md

@@ -56,13 +56,13 @@ we can set up local listeners as proxy servers, and forward requests to internet
 |SSR          | | |√| |client only
 |SSH          | | |√| |client only
 |SOCKS4       | | |√| |client only
+|TCP          |√| |√| |tcp tunnel client & server
+|UDP          | |√| |√|udp tunnel client & server
 |TLS          |√| |√| |transport client & server
 |KCP          | |√|√| |transport client & server
 |Unix         |√| |√| |transport client & server
 |Websocket    |√| |√| |transport client & server
 |Simple-Obfs  | | |√| |transport client only
-|TCPTun       |√| | | |transport server only
-|UDPTun       | |√| | |transport server only
 |Redir        |√| | | |linux only
 |Redir6       |√| | | |linux only(ipv6)
 |Reject       | | |√|√|reject all requests
@@ -94,7 +94,12 @@ glider -h
 <summary>click to see details</summary>
 
 ```bash
-glider 0.12.3 usage:
+glider 0.13.0 usage:
+  -check string
+    	check=tcp[://HOST:PORT]: tcp port connect check
+    	check=http://HOST[:PORT][/URI][#expect=STRING_IN_RESP_LINE]
+    	check=file://SCRIPT_PATH: run a check script, healthy when exitcode=0, environment variables: FORWARDER_ADDR
+    	check=disable: disable health check (default "http://www.msftconnecttest.com/connecttest.txt#expect=200")
   -checkdisabledonly
     	check disabled fowarders only
   -checkinterval int
@@ -103,8 +108,6 @@ glider 0.12.3 usage:
     	fowarder check timeout(seconds) (default 10)
   -checktolerance int
     	fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode
-  -checkwebsite string
-    	fowarder check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80 (default "www.apple.com")
   -config string
     	config file path
   -dialtimeout int
@@ -149,8 +152,8 @@ glider 0.12.3 usage:
     	verbose mode
 
 Available schemes:
-  listen: mixed ss socks5 http vless trojan trojanc redir redir6 tcptun udptun tls ws unix kcp
+  listen: mixed ss socks5 http vless trojan trojanc redir redir6 tcp udp tls ws unix kcp
-  forward: reject ss socks4 socks5 http ssr ssh vless vmess trojan trojanc tls ws unix kcp simple-obfs
+  forward: reject ss socks4 socks5 http ssr ssh vless vmess trojan trojanc tcp udp tls ws unix kcp simple-obfs
 
 Socks5 scheme:
   socks://[user:pass@]host:port
@@ -292,26 +295,20 @@ Examples:
   ./glider -listen redir://:1081 -forward ss://method:pass@1.1.1.1:8443
     -listen on :1081 as a transparent redirect server, forward all requests via remote ss server.
 
-  ./glider -listen redir://:1081 -forward "ssr://method:pass@1.1.1.1:8444?protocol=a&protocol_param=b&obfs=c&obfs_param=d"
-    -listen on :1081 as a transparent redirect server, forward all requests via remote ssr server.
-
   ./glider -listen redir://:1081 -forward "tls://abc.com:443,vmess://security:uuid@?alterID=10"
     -listen on :1081 as a transparent redirect server, forward all requests via remote tls+vmess server.
 
-  ./glider -listen redir://:1081 -forward "ws://1.1.1.1:80,vmess://security:uuid@?alterID=10"
+  ./glider -listen tcp://:80 -forward tcp://2.2.2.2:80
-    -listen on :1081 as a transparent redirect server, forward all requests via remote ws+vmess server.
+    -tcp tunnel: listen on :80 and forward all requests to 2.2.2.2:80.
 
-  ./glider -listen tcptun://:80=2.2.2.2:80 -forward ss://method:pass@1.1.1.1:8443
+  ./glider -listen udp://:53 -forward ss://method:pass@1.1.1.1:8443,udp://8.8.8.8:53
-    -listen on :80 and forward all requests to 2.2.2.2:80 via remote ss server.
-
-  ./glider -listen udptun://:53=8.8.8.8:53 -forward ss://method:pass@1.1.1.1:8443
     -listen on :53 and forward all udp requests to 8.8.8.8:53 via remote ss server.
 
   ./glider -listen socks5://:1080 -listen http://:8080 -forward ss://method:pass@1.1.1.1:8443
     -listen on :1080 as socks5 server, :8080 as http proxy server, forward all requests via remote ss server.
 
-  ./glider -listen redir://:1081 -dns=:53 -dnsserver=8.8.8.8:53 -forward ss://method:pass@server1:port1,ss://method:pass@server2:port2
+  ./glider -listen redir://:1081 -dns=:53 -dnsserver=8.8.8.8:53 -forward ss://method:pass@server:port
-    -listen on :1081 as transparent redirect server, :53 as dns server, use forward chain: server1 -> server2.
+    -listen on :1081 as transparent redirect server, :53 as dns server, forward via ss server.
 
   ./glider -listen socks5://:1080 -forward ss://method:pass@server1:port1 -forward ss://method:pass@server2:port2 -strategy rr
     -listen on :1080 as socks5 server, forward requests via server1 and server2 in round robin mode.

config.go

@@ -131,8 +131,8 @@ func usage() {
 	fmt.Fprintf(w, "\n")
 
 	fmt.Fprintf(w, "Available schemes:\n")
-	fmt.Fprintf(w, "  listen: mixed ss socks5 http vless trojan trojanc redir redir6 tcptun udptun tls ws unix kcp\n")
+	fmt.Fprintf(w, "  listen: mixed ss socks5 http vless trojan trojanc redir redir6 tcp udp tls ws unix kcp\n")
-	fmt.Fprintf(w, "  forward: reject ss socks4 socks5 http ssr ssh vless vmess trojan trojanc tls ws unix kcp simple-obfs\n")
+	fmt.Fprintf(w, "  forward: reject ss socks4 socks5 http ssr ssh vless vmess trojan trojanc tcp udp tls ws unix kcp simple-obfs\n")
 	fmt.Fprintf(w, "\n")
 
 	fmt.Fprintf(w, "Socks5 scheme:\n")
@@ -302,26 +302,20 @@ func usage() {
 	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward ss://method:pass@1.1.1.1:8443\n")
 	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote ss server.\n")
 	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"ssr://method:pass@1.1.1.1:8444?protocol=a&protocol_param=b&obfs=c&obfs_param=d\"\n")
-	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote ssr server.\n")
-	fmt.Fprintf(w, "\n")
 	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"tls://abc.com:443,vmess://security:uuid@?alterID=10\"\n")
 	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote tls+vmess server.\n")
 	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"ws://1.1.1.1:80,vmess://security:uuid@?alterID=10\"\n")
+	fmt.Fprintf(w, "  "+app+" -listen tcp://:80 -forward tcp://2.2.2.2:80\n")
-	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote ws+vmess server.\n")
+	fmt.Fprintf(w, "    -tcp tunnel: listen on :80 and forward all requests to 2.2.2.2:80.\n")
 	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen tcptun://:80=2.2.2.2:80 -forward ss://method:pass@1.1.1.1:8443\n")
+	fmt.Fprintf(w, "  "+app+" -listen udp://:53 -forward ss://method:pass@1.1.1.1:8443,udp://8.8.8.8:53\n")
-	fmt.Fprintf(w, "    -listen on :80 and forward all requests to 2.2.2.2:80 via remote ss server.\n")
-	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen udptun://:53=8.8.8.8:53 -forward ss://method:pass@1.1.1.1:8443\n")
 	fmt.Fprintf(w, "    -listen on :53 and forward all udp requests to 8.8.8.8:53 via remote ss server.\n")
 	fmt.Fprintf(w, "\n")
 	fmt.Fprintf(w, "  "+app+" -listen socks5://:1080 -listen http://:8080 -forward ss://method:pass@1.1.1.1:8443\n")
 	fmt.Fprintf(w, "    -listen on :1080 as socks5 server, :8080 as http proxy server, forward all requests via remote ss server.\n")
 	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -dns=:53 -dnsserver=8.8.8.8:53 -forward ss://method:pass@server1:port1,ss://method:pass@server2:port2\n")
+	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -dns=:53 -dnsserver=8.8.8.8:53 -forward ss://method:pass@server:port\n")
-	fmt.Fprintf(w, "    -listen on :1081 as transparent redirect server, :53 as dns server, use forward chain: server1 -> server2.\n")
+	fmt.Fprintf(w, "    -listen on :1081 as transparent redirect server, :53 as dns server, forward via ss server.\n")
 	fmt.Fprintf(w, "\n")
 	fmt.Fprintf(w, "  "+app+" -listen socks5://:1080 -forward ss://method:pass@server1:port1 -forward ss://method:pass@server2:port2 -strategy rr\n")
 	fmt.Fprintf(w, "    -listen on :1080 as socks5 server, forward requests via server1 and server2 in round robin mode.\n")

config/glider.conf.example

@@ -51,12 +51,6 @@ listen=socks5://:1080
 # listen on 1081 as a linux transparent proxy server.
 # listen=redir://:1081
 
-# listen on 1082 as a tcp tunnel, all requests to :1082 will be forward to 1.1.1.1:80
-# listen=tcptun://:1082=1.1.1.1:80
-
-# listen on 1083 as a udp tunnel, all requests to :1083 will be forward to 1.1.1.1:53
-# listen=udptun://:1083=1.1.1.1:53
-
 # http over tls (HTTPS proxy)
 # listen=tls://:443?cert=crtFilePath&key=keyFilePath,http://
 

feature.go

@@ -22,8 +22,4 @@ import (
 	_ "github.com/nadoo/glider/proxy/vless"
 	_ "github.com/nadoo/glider/proxy/vmess"
 	_ "github.com/nadoo/glider/proxy/ws"
-
-	// deprecated, to be removed.
-	_ "github.com/nadoo/glider/proxy/tcptun"
-	_ "github.com/nadoo/glider/proxy/udptun"
 )

go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/xtaci/kcp-go/v5 v5.6.1
 	golang.org/x/crypto v0.0.0-20201124201722-c8d3bf9c5392
-	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 // indirect
+	golang.org/x/sys v0.0.0-20201126233918-771906719818 // indirect
 	golang.org/x/tools v0.0.0-20201125231158-b5590deeca9b // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 )

go.sum

@@ -128,8 +128,8 @@ golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20201101102859-da207088b7d1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201112073958-5cba982894dd h1:5CtCZbICpIOFdgO940moixOPjc0178IU44m4EjOO5IY=
 golang.org/x/sys v0.0.0-20201112073958-5cba982894dd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
+golang.org/x/sys v0.0.0-20201126233918-771906719818 h1:f1CIuDlJhwANEC2MM87MBEVMr3jl5bifgsfj90XAF9c=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201126233918-771906719818/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221 h1:/ZHdbVpdR/jk3g30/d4yUL0JU9kksj8+F/bnQUVLGDM=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

proxy/proxy.go

@@ -8,7 +8,7 @@ type Proxy interface {
 	Dial(network, addr string) (c net.Conn, dialer Dialer, err error)
 
 	// DialUDP connects to the given address via the proxy.
-	DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error)
+	DialUDP(network, addr string) (pc net.PacketConn, dialer UDPDialer, writeTo net.Addr, err error)
 
 	// Get the dialer by dstAddr.
 	NextDialer(dstAddr string) Dialer

proxy/socks5/server.go

@@ -124,7 +124,7 @@ func (s *Socks5) ListenAndServeUDP() {
 				continue
 			}
 
-			lpc, nextHop, err := s.proxy.DialUDP("udp", c.tgtAddr.String())
+			lpc, _, nextHop, err := s.proxy.DialUDP("udp", c.tgtAddr.String())
 			if err != nil {
 				log.F("[socks5u] remote dial error: %v", err)
 				continue

proxy/ss/server.go

@@ -108,7 +108,7 @@ func (s *SS) ListenAndServeUDP() {
 		var pc *PktConn
 		v, ok := nm.Load(raddr.String())
 		if !ok && v == nil {
-			lpc, nextHop, err := s.proxy.DialUDP("udp", c.tgtAddr.String())
+			lpc, _, nextHop, err := s.proxy.DialUDP("udp", c.tgtAddr.String())
 			if err != nil {
 				log.F("[ssu] remote dial error: %v", err)
 				continue

proxy/tcptun/tcptun.go

@@ -1,99 +0,0 @@
-package tcptun
-
-import (
-	"errors"
-	"net"
-	"net/url"
-	"strings"
-
-	"github.com/nadoo/glider/log"
-	"github.com/nadoo/glider/proxy"
-)
-
-// TCPTun struct.
-type TCPTun struct {
-	proxy proxy.Proxy
-	addr  string
-
-	raddr string
-}
-
-func init() {
-	proxy.RegisterServer("tcptun", NewTCPTunServer)
-}
-
-// NewTCPTun returns a tcptun proxy.
-func NewTCPTun(s string, p proxy.Proxy) (*TCPTun, error) {
-	u, err := url.Parse(s)
-	if err != nil {
-		log.F("[tcptun] parse err: %s", err)
-		return nil, err
-	}
-
-	addr := u.Host
-	d := strings.Split(addr, "=")
-	if len(d) < 2 {
-		return nil, errors.New("error in strings.Split")
-	}
-
-	t := &TCPTun{
-		proxy: p,
-		addr:  d[0],
-		raddr: d[1],
-	}
-
-	return t, nil
-}
-
-// NewTCPTunServer returns a udp tunnel server.
-func NewTCPTunServer(s string, p proxy.Proxy) (proxy.Server, error) {
-	return NewTCPTun(s, p)
-}
-
-// ListenAndServe listens on server's addr and serves connections.
-func (s *TCPTun) ListenAndServe() {
-	l, err := net.Listen("tcp", s.addr)
-	if err != nil {
-		log.F("[tcptun] failed to listen on %s: %v", s.addr, err)
-		return
-	}
-
-	log.F("[tcptun] listening TCP on %s", s.addr)
-
-	for {
-		c, err := l.Accept()
-		if err != nil {
-			log.F("[tcptun] failed to accept: %v", err)
-			continue
-		}
-
-		go s.Serve(c)
-	}
-}
-
-// Serve serves a connection.
-func (s *TCPTun) Serve(c net.Conn) {
-	defer c.Close()
-
-	if c, ok := c.(*net.TCPConn); ok {
-		c.SetKeepAlive(true)
-	}
-
-	rc, dialer, err := s.proxy.Dial("tcp", s.raddr)
-	if err != nil {
-		log.F("[tcptun] %s <-> %s via %s, error in dial: %v", c.RemoteAddr(), s.addr, dialer.Addr(), err)
-		s.proxy.Record(dialer, false)
-		return
-	}
-	defer rc.Close()
-
-	log.F("[tcptun] %s <-> %s via %s", c.RemoteAddr(), s.raddr, dialer.Addr())
-
-	if err = proxy.Relay(c, rc); err != nil {
-		log.F("[tcptun] %s <-> %s via %s, relay error: %v", c.RemoteAddr(), s.raddr, dialer.Addr(), err)
-		// record remote conn failure only
-		if !strings.Contains(err.Error(), s.addr) {
-			s.proxy.Record(dialer, false)
-		}
-	}
-}

proxy/udp/udp.go

@@ -73,10 +73,11 @@ func (s *UDP) ListenAndServe() {
 
 		var raddr net.Addr
 		var pc net.PacketConn
+		var dialer proxy.UDPDialer
 
 		v, ok := nm.Load(lraddr.String())
 		if !ok && v == nil {
-			pc, raddr, err = s.proxy.DialUDP("udp", "")
+			pc, dialer, raddr, err = s.proxy.DialUDP("udp", "")
 			if err != nil {
 				log.F("[udp] remote dial error: %v", err)
 				continue
@@ -100,7 +101,7 @@ func (s *UDP) ListenAndServe() {
 			continue
 		}
 
-		log.F("[udp] %s <-> %s", lraddr, raddr)
+		log.F("[udp] %s <-> %s", lraddr, dialer.Addr())
 
 	}
 }

proxy/udptun/udptun.go

@@ -1,113 +0,0 @@
-package udptun
-
-import (
-	"errors"
-	"net"
-	"net/url"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/nadoo/glider/log"
-	"github.com/nadoo/glider/proxy"
-)
-
-// UDPTun is a base udptun struct.
-type UDPTun struct {
-	proxy  proxy.Proxy
-	addr   string
-	taddr  string       // tunnel addr string
-	tuaddr *net.UDPAddr // tunnel addr
-}
-
-func init() {
-	proxy.RegisterServer("udptun", NewUDPTunServer)
-}
-
-// NewUDPTun returns a UDPTun proxy.
-func NewUDPTun(s string, p proxy.Proxy) (*UDPTun, error) {
-	u, err := url.Parse(s)
-	if err != nil {
-		log.F("[udptun] parse err: %s", err)
-		return nil, err
-	}
-
-	addr := u.Host
-	d := strings.Split(addr, "=")
-	if len(d) < 2 {
-		return nil, errors.New("error in strings.Split")
-	}
-
-	ut := &UDPTun{
-		proxy: p,
-		addr:  d[0],
-		taddr: d[1],
-	}
-
-	ut.tuaddr, err = net.ResolveUDPAddr("udp", ut.taddr)
-	return ut, err
-}
-
-// NewUDPTunServer returns a udp tunnel server.
-func NewUDPTunServer(s string, p proxy.Proxy) (proxy.Server, error) {
-	return NewUDPTun(s, p)
-}
-
-// ListenAndServe listen and serves on the given address.
-func (s *UDPTun) ListenAndServe() {
-	c, err := net.ListenPacket("udp", s.addr)
-	if err != nil {
-		log.F("[udptun] failed to listen on %s: %v", s.addr, err)
-		return
-	}
-	defer c.Close()
-
-	log.F("[udptun] listening UDP on %s", s.addr)
-
-	var nm sync.Map
-	buf := make([]byte, proxy.UDPBufSize)
-
-	for {
-		n, raddr, err := c.ReadFrom(buf)
-		if err != nil {
-			log.F("[udptun] read error: %v", err)
-			continue
-		}
-
-		var pc net.PacketConn
-
-		v, ok := nm.Load(raddr.String())
-		if !ok && v == nil {
-			pc, _, err = s.proxy.DialUDP("udp", s.taddr)
-			if err != nil {
-				log.F("[udptun] remote dial error: %v", err)
-				continue
-			}
-
-			nm.Store(raddr.String(), pc)
-
-			go func(c, pc net.PacketConn, raddr net.Addr) {
-				proxy.RelayUDP(c, raddr, pc, 2*time.Minute)
-				pc.Close()
-				nm.Delete(raddr.String())
-			}(c, pc, raddr)
-
-		} else {
-			pc = v.(net.PacketConn)
-		}
-
-		_, err = pc.WriteTo(buf[:n], s.tuaddr)
-		if err != nil {
-			log.F("[udptun] remote write error: %v", err)
-			continue
-		}
-
-		log.F("[udptun] %s <-> %s", raddr, s.taddr)
-
-	}
-}
-
-// Serve serves a net.Conn, can not be called directly.
-func (s *UDPTun) Serve(c net.Conn) {
-	log.F("[udptun] func Serve: can not be called directly")
-}

rule/forward.go

@@ -48,16 +48,26 @@ func ForwarderFromURL(s, intface string, dialTimeout, relayTimeout time.Duration
 		return nil, err
 	}
 
+	var addrs []string
 	for _, url := range strings.Split(ss[0], ",") {
 		d, err = proxy.DialerFromURL(url, d)
 		if err != nil {
 			return nil, err
 		}
+		cnt := len(addrs)
+		if cnt == 0 ||
+			(cnt > 0 && d.Addr() != addrs[cnt-1]) {
+			addrs = append(addrs, d.Addr())
+		}
 	}
 
 	f.Dialer = d
 	f.addr = d.Addr()
 
+	if len(addrs) > 0 {
+		f.addr = strings.Join(addrs, ",")
+	}
+
 	// set forwarder to disabled by default
 	f.Disable()
 
@@ -70,7 +80,6 @@ func DirectForwarder(intface string, dialTimeout, relayTimeout time.Duration) *F
 	if err != nil {
 		return nil
 	}
-
 	return &Forwarder{Dialer: d, addr: d.Addr()}
 }
 
@@ -93,6 +102,7 @@ func (f *Forwarder) parseOption(option string) error {
 }
 
 // Addr returns the forwarder's addr.
+// NOTE: addr returns for chained dialers: dialer1Addr,dialer2Addr,...
 func (f *Forwarder) Addr() string {
 	return f.addr
 }
@@ -103,7 +113,6 @@ func (f *Forwarder) Dial(network, addr string) (c net.Conn, err error) {
 	if err != nil {
 		f.IncFailures()
 	}
-
 	return c, err
 }
 

rule/group.go

@@ -102,8 +102,10 @@ func (p *FwdrGroup) Dial(network, addr string) (net.Conn, proxy.Dialer, error) {
 }
 
 // DialUDP connects to the given address.
-func (p *FwdrGroup) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
+func (p *FwdrGroup) DialUDP(network, addr string) (pc net.PacketConn, dialer proxy.UDPDialer, writeTo net.Addr, err error) {
-	return p.NextDialer(addr).DialUDP(network, addr)
+	nd := p.NextDialer(addr)
+	pc, wt, err := nd.DialUDP(network, addr)
+	return pc, nd, wt, err
 }
 
 // NextDialer returns the next dialer.
@@ -244,6 +246,7 @@ func (p *FwdrGroup) check(fwdr *Forwarder, checker Checker) {
 			if errors.Is(err, proxy.ErrNotSupported) {
 				fwdr.SetMaxFailures(0)
 				log.F("[check] %s(%d), %s, stop checking", fwdr.Addr(), fwdr.Priority(), err)
+				fwdr.Enable()
 				break
 			}
 
@@ -258,9 +261,9 @@ func (p *FwdrGroup) check(fwdr *Forwarder, checker Checker) {
 		}
 
 		wait = 1
-		fwdr.Enable()
 		fwdr.SetLatency(int64(elapsed))
 		log.F("[check] %s(%d), SUCCESS. elapsed: %s", fwdr.Addr(), fwdr.Priority(), elapsed)
+		fwdr.Enable()
 	}
 }
 

rule/proxy.go

@@ -61,7 +61,7 @@ func (p *Proxy) Dial(network, addr string) (net.Conn, proxy.Dialer, error) {
 }
 
 // DialUDP connects to the given address via the proxy.
-func (p *Proxy) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
+func (p *Proxy) DialUDP(network, addr string) (pc net.PacketConn, dialer proxy.UDPDialer, writeTo net.Addr, err error) {
 	return p.findDialer(addr).DialUDP(network, addr)
 }