rename

config.go

@@ -15,8 +15,7 @@ type Config struct {
 	TLSInsecure bool
 	Limiter     *rate.Limiter
 	DNS         string
-	Socks       bool
+	TCPProxy    string
-	Proxy       string
 }
 
 func NewConfig() *Config {
@@ -25,11 +24,10 @@ func NewConfig() *Config {
 	as.Append(args.INT, "p", "port to listen on", 61113)
 	as.Append(args.INT, "kbps", "kilobytes per sec limit", -1)
 	as.Append(args.BOOL, "tls-insecure", "permit tls insecure", false)
-	as.Append(args.BOOL, "socks", "accept socks instead", false)
 	as.Append(args.DURATION, "t", "timeout", time.Minute)
 
 	as.Append(args.STRING, "dns", "dns ip:port", "1.1.1.1:53")
-	as.Append(args.STRING, "proxy", "scheme://host:port to proxy proxied to", "")
+	as.Append(args.STRING, "tcp-proxy", "host:port to tcp proxy to instead", "")
 
 	if err := as.Parse(); err != nil {
 		panic(err)
@@ -47,7 +45,6 @@ func NewConfig() *Config {
 		TLSInsecure: as.GetBool("tls-insecure"),
 		Limiter:     limiter,
 		DNS:         as.GetString("dns"),
-		Socks:       as.GetBool("socks"),
+		TCPProxy:    as.GetString("tcp-proxy"),
-		Proxy:       as.GetString("proxy"),
 	}
 }

main.go

@@ -9,8 +9,8 @@ func main() {
 	config := NewConfig()
 	log.Printf("config: %+v", *config)
 
-	if config.Socks {
+	if config.TCPProxy != "" {
-		server := NewSocksServer(config)
+		server := NewTCPServer(config)
 		if err := server.Listen(); err != nil {
 			panic(err)
 		}

socks.go

@@ -1,22 +0,0 @@
-package main
-
-import (
-	"github.com/armon/go-socks5"
-)
-
-type Socks struct {
-	config *Config
-}
-
-func NewSocksServer(c *Config) Socks {
-	return Socks{config: c}
-}
-
-func (socks Socks) Listen() error {
-	conf := &socks5.Config{}
-	server, err := socks5.New(conf)
-	if err != nil {
-		return err
-	}
-	return server.ListenAndServe("tcp", socks.config.Listen)
-}

tcp.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"io"
+	"log"
+	"net"
+)
+
+type TCP struct {
+	config *Config
+}
+
+func NewTCPServer(c *Config) TCP {
+	return TCP{config: c}
+}
+
+func (tcp TCP) Listen() error {
+	ln, err := net.Listen("tcp", tcp.config.Listen)
+	if err != nil {
+		return err
+	}
+	defer ln.Close()
+
+	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			return err
+		}
+		go func() {
+			defer conn.Close()
+
+			conn2, err := net.Dial("tcp", tcp.config.TCPProxy)
+			if err != nil {
+				log.Println(err)
+				return
+			}
+
+			errc := make(chan error)
+			go func() {
+				_, err := io.Copy(conn, conn2)
+				select {
+				case errc <- err:
+				default:
+				}
+			}()
+			go func() {
+				_, err := io.Copy(conn2, conn)
+				select {
+				case errc <- err:
+				default:
+				}
+			}()
+			<-errc
+		}()
+	}
+}