go fmt

socks4.go

@@ -1,104 +1,104 @@
-package socks
+package socks
-
+
-import (
+import (
-	"encoding/binary"
+	"encoding/binary"
-	"fmt"
+	"fmt"
-	"io"
+	"io"
-	"log"
+	"log"
-	"net"
+	"net"
-)
+)
-
+
-type socks4Conn struct {
+type socks4Conn struct {
-	server_conn net.Conn
+	server_conn net.Conn
-	client_conn net.Conn
+	client_conn net.Conn
-}
+}
-
+
-func (s4 *socks4Conn) Serve() {
+func (s4 *socks4Conn) Serve() {
-	defer s4.Close()
+	defer s4.Close()
-	if err := s4.processRequest(); err != nil {
+	if err := s4.processRequest(); err != nil {
-		log.Println(err)
+		log.Println(err)
-		return
+		return
-	}
+	}
-}
+}
-
+
-func (s4 *socks4Conn) Close() {
+func (s4 *socks4Conn) Close() {
-	if s4.client_conn != nil {
+	if s4.client_conn != nil {
-		s4.client_conn.Close()
+		s4.client_conn.Close()
-	}
+	}
-	if s4.server_conn != nil {
+	if s4.server_conn != nil {
-		s4.server_conn.Close()
+		s4.server_conn.Close()
-	}
+	}
-}
+}
-
+
-func (s4 *socks4Conn) forward() {
+func (s4 *socks4Conn) forward() {
-	go func() {
+	go func() {
-		io.Copy(s4.client_conn, s4.server_conn)
+		io.Copy(s4.client_conn, s4.server_conn)
-	}()
+	}()
-
+
-	io.Copy(s4.server_conn, s4.client_conn)
+	io.Copy(s4.server_conn, s4.client_conn)
-}
+}
-
+
-func (s4 *socks4Conn) processRequest() error {
+func (s4 *socks4Conn) processRequest() error {
-	// version has already read out by socksConn.Serve()
+	// version has already read out by socksConn.Serve()
-	// process command and target here
+	// process command and target here
-
+
-	buf := make([]byte, 128)
+	buf := make([]byte, 128)
-	n, err := io.ReadAtLeast(s4.client_conn, buf, 8)
+	n, err := io.ReadAtLeast(s4.client_conn, buf, 8)
-	if err != nil {
+	if err != nil {
-		return err
+		return err
-	}
+	}
-
+
-	// only support connect
+	// only support connect
-	if buf[0] != cmdConnect {
+	if buf[0] != cmdConnect {
-		return fmt.Errorf("error command %s", buf[0])
+		return fmt.Errorf("error command %s", buf[0])
-	}
+	}
-
+
-	port := binary.BigEndian.Uint16(buf[1:3])
+	port := binary.BigEndian.Uint16(buf[1:3])
-
+
-	ip := net.IP(buf[3:7])
+	ip := net.IP(buf[3:7])
-
+
-	// NULL-terminated user string
+	// NULL-terminated user string
-	// jump to NULL character
+	// jump to NULL character
-	var j int
+	var j int
-	for j = 7; j < n; j++ {
+	for j = 7; j < n; j++ {
-		if buf[j] == 0x00 {
+		if buf[j] == 0x00 {
-			break
+			break
-		}
+		}
-	}
+	}
-
+
-	host := ip.String()
+	host := ip.String()
-
+
-	// socks4a
+	// socks4a
-	// 0.0.0.x
+	// 0.0.0.x
-	if ip[0] == 0x00 && ip[1] == 0x00 && ip[2] == 0x00 && ip[3] != 0x00 {
+	if ip[0] == 0x00 && ip[1] == 0x00 && ip[2] == 0x00 && ip[3] != 0x00 {
-		j++
+		j++
-		var i = j
+		var i = j
-
+
-		// jump to the end of hostname
+		// jump to the end of hostname
-		for j = i; j < n; j++ {
+		for j = i; j < n; j++ {
-			if buf[j] == 0x00 {
+			if buf[j] == 0x00 {
-				break
+				break
-			}
+			}
-		}
+		}
-		host = string(buf[i:j])
+		host = string(buf[i:j])
-	}
+	}
-
+
-	target := net.JoinHostPort(host, fmt.Sprintf("%d", port))
+	target := net.JoinHostPort(host, fmt.Sprintf("%d", port))
-
+
-	// reply user with connect success
+	// reply user with connect success
-	// if dial to target failed, user will receive connection reset
+	// if dial to target failed, user will receive connection reset
-	s4.client_conn.Write([]byte{0x00, 0x5a, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00})
+	s4.client_conn.Write([]byte{0x00, 0x5a, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00})
-
+
-	log.Printf("connecting to %s", target)
+	log.Printf("connecting to %s", target)
-
+
-	// connect to the target
+	// connect to the target
-	s4.server_conn, err = net.Dial("tcp", target)
+	s4.server_conn, err = net.Dial("tcp", target)
-	if err != nil {
+	if err != nil {
-		return err
+		return err
-	}
+	}
-
+
-	// enter data exchange
+	// enter data exchange
-	s4.forward()
+	s4.forward()
-
+
-	return nil
+	return nil
-}
+}