add shadowsocks compatible

gost.go

@@ -13,7 +13,10 @@ import (
 	"strconv"
 	"strings"
 	//"sync/atomic"
-	//"fmt"
+	"encoding/binary"
+	"fmt"
+	"github.com/shadowsocks/shadowsocks-go/shadowsocks"
+	"net/url"
 	"time"
 )
 
@@ -24,6 +27,7 @@ const (
 
 type Gost struct {
 	Laddr, Saddr, Proxy string
+	Shadows             bool // shadowsocks compatible
 }
 
 func (g *Gost) Run() error {
@@ -43,6 +47,7 @@ func (g *Gost) Run() error {
 			log.Println("accept:", err)
 			continue
 		}
+		//log.Println("accept", conn.RemoteAddr().String())
 		go g.handle(conn)
 	}
 
@@ -62,7 +67,13 @@ func (g *Gost) handle(conn net.Conn) {
 }
 
 func (g *Gost) cli(conn net.Conn) {
-	lg := NewLog()
+	lg := NewLog(true)
+	defer func() {
+		lg.Logln()
+		lg.Flush()
+	}()
+
+	lg.Logln("accept", conn.(*net.TCPConn).RemoteAddr().String())
 
 	sconn, err := g.connect(g.Saddr)
 	if err != nil {
@@ -80,6 +91,48 @@ func (g *Gost) cli(conn net.Conn) {
 	}
 	lg.Logln(">>>|", []byte{5, 1, 0})
 
+	if g.Shadows {
+		lg.Logln("shadowsocks, aes-256-cfb")
+		cipher, _ := shadowsocks.NewCipher("aes-256-cfb", "123456")
+		conn = shadowsocks.NewConn(conn, cipher)
+		addr, port, extra, err := getRequest(conn)
+		if err != nil {
+			lg.Logln(err)
+			return
+		}
+		lg.Logln(addr, port)
+
+		cmd := NewCmd(CmdConnect, AddrDomain, addr, port)
+		if err = cmd.Write(sconn); err != nil {
+			lg.Logln(err)
+			return
+		}
+		lg.Logln(">>>|", cmd)
+
+		if cmd, err = ReadCmd(sconn); err != nil {
+			lg.Logln(err)
+			return
+		}
+		lg.Logln("<<<|", cmd)
+
+		if cmd.Cmd != Succeeded {
+			conn.Write([]byte("HTTP/1.1 503 Service unavailable\r\n" +
+				"Proxy-Agent: gost/1.0\r\n\r\n"))
+			return
+		}
+
+		if extra != nil {
+			if _, err := sconn.Write(extra); err != nil {
+				log.Println(err)
+				return
+			}
+		}
+
+		g.transport(conn, sconn)
+
+		return
+	}
+
 	b := make([]byte, 8192)
 
 	n, err := io.ReadFull(sconn, b[:2])
@@ -94,7 +147,7 @@ func (g *Gost) cli(conn net.Conn) {
 		lg.Logln(err)
 		return
 	}
-
+	//log.Println(b[:n])
 	if b[0] == 5 { // socks5,NO AUTHENTICATION
 		lg.Logln("|>>>", b[:n])
 
@@ -130,9 +183,6 @@ func (g *Gost) cli(conn net.Conn) {
 		}
 		lg.Logln("|<<<", cmd)
 
-		lg.Logln()
-		lg.Flush()
-
 		g.transport(conn, sconn)
 		return
 	}
@@ -192,14 +242,17 @@ func (g *Gost) cli(conn net.Conn) {
 		}
 	}
 
-	lg.Logln()
-	lg.Flush()
 	g.transport(conn, sconn)
 }
 
 func (g *Gost) srv(conn net.Conn) {
 	b := make([]byte, 8192)
-	lg := NewLog()
+	lg := NewLog(true)
+	defer func() {
+		lg.Logln()
+		lg.Flush()
+	}()
+	lg.Logln("accept", conn.(*net.TCPConn).RemoteAddr().String())
 
 	n, err := conn.Read(b)
 	if err != nil {
@@ -306,36 +359,34 @@ func (g *Gost) connect(addr string) (net.Conn, error) {
 	}
 	pconn, err := net.DialTCP("tcp", nil, paddr)
 	if err != nil {
+		log.Println(err)
 		return nil, 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 {
+	header := http.Header{}
+	header.Set("Proxy-Connection", "keep-alive")
+	req := &http.Request{
+		Method: "CONNECT",
+		URL:    &url.URL{Host: addr},
+		Host:   addr,
+		Header: header,
+	}
+	if err := req.Write(pconn); err != nil {
+		log.Println(err)
 		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
-		}
-		r += string(b[:n])
-	}
-
-	log.Println(r)
-	if !strings.Contains(r, "200") {
-		log.Println("connection failed:\n", r)
-		err = errors.New(r)
+	resp, err := http.ReadResponse(bufio.NewReader(pconn), req)
+	if err != nil {
+		log.Println(err)
 		pconn.Close()
 		return nil, err
 	}
+	if resp.StatusCode != http.StatusOK {
+		pconn.Close()
+		return nil, errors.New(resp.Status)
+	}
 
 	return pconn, nil
 }
@@ -361,3 +412,72 @@ func (g *Gost) transport(conn, conn2 net.Conn) (err error) {
 
 	return
 }
+
+func getRequest(conn net.Conn) (host string, port uint16, extra []byte, err error) {
+	const (
+		idType  = 0 // address type index
+		idIP0   = 1 // ip addres start index
+		idDmLen = 1 // domain address length index
+		idDm0   = 2 // domain address start index
+
+		typeIPv4 = 1 // type is ipv4 address
+		typeDm   = 3 // type is domain address
+		typeIPv6 = 4 // type is ipv6 address
+
+		lenIPv4   = 1 + net.IPv4len + 2 // 1addrType + ipv4 + 2port
+		lenIPv6   = 1 + net.IPv6len + 2 // 1addrType + ipv6 + 2port
+		lenDmBase = 1 + 1 + 2           // 1addrType + 1addrLen + 2port, plus addrLen
+	)
+
+	// buf size should at least have the same size with the largest possible
+	// request size (when addrType is 3, domain name has at most 256 bytes)
+	// 1(addrType) + 1(lenByte) + 256(max length address) + 2(port)
+	buf := make([]byte, 260)
+	var n int
+	// read till we get possible domain length field
+	//ss.SetReadTimeout(conn)
+	if n, err = io.ReadAtLeast(conn, buf, idDmLen+1); err != nil {
+		log.Println(err)
+		return
+	}
+	log.Println(buf[:n])
+
+	reqLen := -1
+	switch buf[idType] {
+	case typeIPv4:
+		reqLen = lenIPv4
+	case typeIPv6:
+		reqLen = lenIPv6
+	case typeDm:
+		reqLen = int(buf[idDmLen]) + lenDmBase
+	default:
+		err = fmt.Errorf("addr type %d not supported", buf[idType])
+		return
+	}
+
+	if n < reqLen { // rare case
+		//ss.SetReadTimeout(conn)
+		if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil {
+			log.Println(err)
+			return
+		}
+	} else if n > reqLen {
+		// it's possible to read more than just the request head
+		extra = buf[reqLen:n]
+	}
+
+	// Return string for typeIP is not most efficient, but browsers (Chrome,
+	// Safari, Firefox) all seems using typeDm exclusively. So this is not a
+	// big problem.
+	switch buf[idType] {
+	case typeIPv4:
+		host = net.IP(buf[idIP0 : idIP0+net.IPv4len]).String()
+	case typeIPv6:
+		host = net.IP(buf[idIP0 : idIP0+net.IPv6len]).String()
+	case typeDm:
+		host = string(buf[idDm0 : idDm0+buf[idDmLen]])
+	}
+	// parse port
+	port = binary.BigEndian.Uint16(buf[reqLen-2 : reqLen])
+	return
+}

log.go

@@ -7,16 +7,24 @@ import (
 	"os"
 )
 
+var (
+	Debug bool
+)
+
 type BufferedLog struct {
 	buffer *bytes.Buffer
 	w      io.WriteCloser
 }
 
-func NewLog() *BufferedLog {
-	return &BufferedLog{
-		buffer: &bytes.Buffer{},
-		w:      os.Stdout,
+func NewLog(buffered bool) *BufferedLog {
+	log := &BufferedLog{
+		w: os.Stdout,
 	}
+	if buffered {
+		log.buffer = &bytes.Buffer{}
+	}
+
+	return log
 }
 
 func NewFileLog(file *os.File) *BufferedLog {
@@ -27,15 +35,33 @@ func NewFileLog(file *os.File) *BufferedLog {
 }
 
 func (log *BufferedLog) Log(a ...interface{}) (int, error) {
-	return fmt.Fprint(log.buffer, a...)
+	if !Debug {
+		return 0, nil
+	}
+	if log.buffer != nil {
+		return fmt.Fprint(log.buffer, a...)
+	}
+	return fmt.Fprint(log.w, a...)
 }
 
 func (log *BufferedLog) Logln(a ...interface{}) (int, error) {
-	return fmt.Fprintln(log.buffer, a...)
+	if !Debug {
+		return 0, nil
+	}
+	if log.buffer != nil {
+		return fmt.Fprintln(log.buffer, a...)
+	}
+	return fmt.Fprintln(log.w, a...)
 }
 
 func (log *BufferedLog) Logf(format string, a ...interface{}) (int, error) {
-	return fmt.Fprintf(log.buffer, format, a...)
+	if !Debug {
+		return 0, nil
+	}
+	if log.buffer != nil {
+		return fmt.Fprintf(log.buffer, format, a...)
+	}
+	return fmt.Fprintf(log.w, format, a...)
 }
 
 func (log *BufferedLog) Flush() error {
@@ -45,6 +71,10 @@ func (log *BufferedLog) Flush() error {
 		}
 	}()
 
+	if !Debug || log.buffer == nil {
+		return nil
+	}
+
 	_, err := log.buffer.WriteTo(log.w)
 	return err
 }

main.go

@@ -12,6 +12,8 @@ func init() {
 	flag.StringVar(&gost.Proxy, "P", "", "proxy for forward")
 	flag.StringVar(&gost.Saddr, "S", "", "the server that connecting to")
 	flag.StringVar(&gost.Laddr, "L", ":8080", "listen address")
+	flag.BoolVar(&gost.Shadows, "ss", false, "shadowsocks compatible")
+	flag.BoolVar(&Debug, "d", false, "debug option")
 	flag.Parse()
 
 	log.SetFlags(log.LstdFlags | log.Lshortfile)