diff --git a/gost.go b/gost.go
index 2bb2641..90c47f3 100644
--- a/gost.go
+++ b/gost.go
@@ -1,17 +1,17 @@
 package main
 
 import (
-	//"bufio"
-	//"bytes"
+	"bufio"
+	"bytes"
 	//"crypto/tls"
-	//"errors"
+	"errors"
 	"io"
 	//"io/ioutil"
 	"log"
 	"net"
-	//"net/http"
-	//"strconv"
-	//"strings"
+	"net/http"
+	"strconv"
+	"strings"
 	//"sync/atomic"
 	"time"
 )
@@ -42,58 +42,158 @@ func (g *Gost) Run() error {
 			log.Println("accept:", err)
 			continue
 		}
-		go g.serve(conn)
+		go g.handle(conn)
 	}
 
 	return ln.Close()
 }
 
-func (g *Gost) serve(conn net.Conn) error {
-	var pconn net.Conn
+func (g *Gost) handle(conn net.Conn) {
 	defer conn.Close()
 
+	// as client
+	if len(g.Saddr) > 0 {
+		g.cli(conn)
+		return
+	}
+
+	// as server
+	g.srv(conn)
+}
+
+func (g *Gost) cli(conn net.Conn) {
+	sconn, err := g.connect(g.Saddr)
+	if err != nil {
+		return
+	}
+	defer sconn.Close()
+
+	g.transport(conn, sconn)
+	return
+}
+
+func (g *Gost) srv(conn net.Conn) {
+	b := make([]byte, 8192)
+
+	n, err := conn.Read(b)
+	if err != nil {
+		log.Println(err)
+		return
+	}
+
+	if bytes.Equal(b[:n], []byte{5, 1, 0}) { // socks5,NO AUTHENTICATION
+		log.Println("read cmd:", b[:n])
+		if _, err := conn.Write([]byte{5, 0}); err != nil {
+			log.Println(err)
+			return
+		}
+
+		cmd, err := ReadCmd(conn)
+		if err != nil {
+			return
+		}
+		host := cmd.Addr + ":" + strconv.Itoa(int(cmd.Port))
+		log.Println("connect", host)
+		tconn, err := g.connect(host)
+		if err != nil {
+			log.Println(err)
+			NewCmd(ConnRefused, 0, "", 0).Write(conn)
+			return
+		}
+		defer tconn.Close()
+
+		if err = NewCmd(Succeeded, AddrIPv4, "0.0.0.0", 0).Write(conn); err != nil {
+			log.Println(err)
+			return
+		}
+
+		g.transport(conn, tconn)
+		return
+	}
+
+	//log.Println(string(b[:n]))
+	req, err := http.ReadRequest(bufio.NewReader(bytes.NewReader(b[:n])))
+	if err != nil {
+		log.Println(err)
+		return
+	}
+
+	log.Println(req.Method, req.RequestURI)
+	host := req.Host
+	if !strings.Contains(host, ":") {
+		host = host + ":80"
+	}
+	tconn, err := g.connect(host)
+	if err != nil {
+		log.Println(err)
+		conn.Write([]byte("HTTP/1.1 503 Service unavailable\r\n" +
+			"Proxy-Agent: gost/1.0\r\n\r\n"))
+		return
+	}
+	defer tconn.Close()
+
+	if req.Method == "CONNECT" {
+		if _, err = conn.Write(
+			[]byte("HTTP/1.1 200 Connection established\r\n" +
+				"Proxy-Agent: gost/1.0\r\n\r\n")); err != nil {
+			return
+		}
+	} else {
+		if err := req.Write(tconn); err != nil {
+			return
+		}
+	}
+
+	g.transport(conn, tconn)
+}
+
+func (g *Gost) connect(addr string) (net.Conn, error) {
+	if len(g.Proxy) == 0 {
+		taddr, err := net.ResolveTCPAddr("tcp", addr)
+		if err != nil {
+			return nil, err
+		}
+		return net.DialTCP("tcp", nil, taddr)
+	}
+
 	paddr, err := net.ResolveTCPAddr("tcp", g.Proxy)
 	if err != nil {
-		log.Println(err)
+		return nil, err
 	}
-	if paddr != nil {
-		pconn, err = net.DialTCP("tcp", nil, paddr)
-		if err != nil {
-			return err
-		}
-		return g.foward(conn, pconn)
-	}
-
-	saddr, err := net.ResolveTCPAddr("tcp", g.Saddr)
+	pconn, err := net.DialTCP("tcp", nil, paddr)
 	if err != nil {
-		log.Println(err)
+		return nil, err
 	}
-	if saddr != nil {
-		sconn, err := net.DialTCP("tcp", nil, saddr)
-		if err != nil {
-			return err
+
+	b := make([]byte, 1500)
+	buffer := bytes.NewBuffer(b)
+	buffer.WriteString("CONNECT " + addr + " HTTP/1.1\r\n")
+	buffer.WriteString("Host: " + addr + "\r\n")
+	buffer.WriteString("Proxy-Connection: keep-alive\r\n\r\n")
+	if _, err = pconn.Write(buffer.Bytes()); err != nil {
+		pconn.Close()
+		return nil, err
+	}
+
+	r := ""
+	for !strings.HasSuffix(r, "\r\n\r\n") {
+		n := 0
+		if n, err = pconn.Read(b); err != nil {
+			pconn.Close()
+			return nil, err
 		}
-		defer sconn.Close()
-
-		return g.transport(conn, sconn)
+		r += string(b[:n])
 	}
 
-	return nil
-}
-
-func (g *Gost) foward(conn, pconn net.Conn) error {
-	defer pconn.Close()
-
-	saddr, err := net.ResolveTCPAddr("tcp", g.Saddr)
-	if err != nil {
-		log.Println(err)
+	log.Println(r)
+	if !strings.Contains(r, "200") {
+		log.Println("connection failed:\n", r)
+		err = errors.New(r)
+		pconn.Close()
+		return nil, err
 	}
 
-	if saddr != nil {
-
-	}
-
-	return nil
+	return pconn, nil
 }
 
 func (g *Gost) pipe(src io.Reader, dst io.Writer, c chan<- error) {
@@ -101,7 +201,7 @@ func (g *Gost) pipe(src io.Reader, dst io.Writer, c chan<- error) {
 	c <- err
 }
 
-func (g *Gost) transport(conn net.Conn, conn2 net.Conn) (err error) {
+func (g *Gost) transport(conn, conn2 net.Conn) (err error) {
 	rChan := make(chan error, 1)
 	wChan := make(chan error, 1)
 
@@ -110,7 +210,9 @@ func (g *Gost) transport(conn net.Conn, conn2 net.Conn) (err error) {
 
 	select {
 	case err = <-wChan:
+		//log.Println("w exit", err)
 	case err = <-rChan:
+		//log.Println("r exit", err)
 	}
 
 	return
diff --git a/gost2 b/gost2
deleted file mode 100755
index 7b17d2d..0000000
Binary files a/gost2 and /dev/null differ
diff --git a/socks5.go b/socks5.go
index 646cea7..c8795b3 100644
--- a/socks5.go
+++ b/socks5.go
@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
+	"log"
 	"net"
 )
 
@@ -91,6 +92,7 @@ func ReadCmd(r io.Reader) (*Cmd, error) {
 	if err != nil {
 		return nil, err
 	}
+	log.Println("read cmd:", b[:n])
 	if n < 10 {
 		return nil, ErrBadFormat
 	}
@@ -128,7 +130,7 @@ func ReadCmd(r io.Reader) (*Cmd, error) {
 		cmd.Addr = string(b[pos : pos+length])
 		pos += length
 	default:
-		return nil, ErrBadAddrType
+		pos += 4
 	}
 
 	cmd.Port = binary.BigEndian.Uint16(b[pos:])
@@ -157,6 +159,7 @@ func (cmd *Cmd) Write(w io.Writer) (err error) {
 	binary.BigEndian.PutUint16(b[pos:], cmd.Port)
 	pos += 2
 
+	log.Println("write cmd:", b[:pos])
 	_, err = w.Write(b[:pos])
 
 	return