2024年6月7日11:21:00 socket5 代理

config/config.go

@@ -0,0 +1,6 @@
+package config
+
+const (
+	LOCAL_SOCKET_ADDR = "127.0.0.1"
+	LOCAL_SOCKET_PORT = 1080
+)

go.mod

@@ -0,0 +1,3 @@
+module go-socket5-proxy
+
+go 1.20

helper/helper.go

@@ -0,0 +1,28 @@
+package helper
+
+import (
+	"log"
+	"net"
+)
+
+// CreateListen 监听
+func CreateListen(serverAddr string) (*net.TCPListener, error) {
+	tcpAddr, err := net.ResolveTCPAddr("tcp", serverAddr)
+	if err != nil {
+		log.Println("创建监听出错:" + serverAddr)
+		return nil, err
+	}
+	tcpListen, err := net.ListenTCP("tcp", tcpAddr)
+	return tcpListen, err
+}
+
+// CreateConn 创建连接
+func CreateConn(serverAddr string) (*net.TCPConn, error) {
+	tcpAddr, err := net.ResolveTCPAddr("tcp", serverAddr)
+	if err != nil {
+		log.Println("创建连接出错:" + serverAddr)
+		return nil, err
+	}
+	conn, err := net.DialTCP("tcp", nil, tcpAddr)
+	return conn, err
+}

server/main.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"go-socket5-proxy/config"
+	"go-socket5-proxy/socket5"
+)
+
+func main() {
+	server := &socket5.Socket5Server{
+		IP:   config.LOCAL_SOCKET_ADDR,
+		Port: config.LOCAL_SOCKET_PORT,
+	}
+	server.Run()
+}

socket5/auth.go

@@ -0,0 +1,68 @@
+package socket5
+
+import (
+	"errors"
+	"io"
+	"net"
+)
+
+var (
+	ERROR_SOCKET_VERSION_SUPPORTED = errors.New("不支持该socket版本")
+	ERROR_COMMAND_NOT_SUPPORTED    = errors.New("不支持该COMMAND命令")
+	ERRADDRESS_TYPE_NOT_SUPPORTED  = errors.New("不支持该地址类型")
+)
+
+const (
+	SOCKET_5_VERSION       = 0x05
+	Method_NO_AUTH         = 0x00
+	Method_GSS_API         = 0x01
+	Method_PASS_WORD       = 0x02
+	Method_NO_ACCEPT_TABLE = 0xff
+	ReservedFild           = 0x00
+)
+
+type Method = byte
+
+type ClientAuthMessage struct {
+	Version byte
+
+	NMethods byte
+
+	Methods []Method
+}
+
+func NewServerAuthMessage(conn net.Conn, method Method) error {
+	buf := []byte{SOCKET_5_VERSION, method}
+	_, err := conn.Write(buf)
+	return err
+}
+
+func NewClientAuthMessage(conn net.Conn) (*ClientAuthMessage, error) {
+
+	//读取socket版本
+	buf := make([]byte, 2)
+	_, err := io.ReadFull(conn, buf)
+	if err != nil {
+		return nil, err
+	}
+	//校验socket 版本
+	if buf[0] != SOCKET_5_VERSION {
+		return nil, ERROR_SOCKET_VERSION_SUPPORTED
+	}
+
+	//读取method
+	nmethos := buf[1]
+
+	buf = make([]byte, nmethos)
+	_, err = io.ReadFull(conn, buf)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &ClientAuthMessage{
+		Version:  SOCKET_5_VERSION,
+		NMethods: nmethos,
+		Methods:  buf,
+	}, nil
+}

socket5/request.go

@@ -0,0 +1,151 @@
+package socket5
+
+import (
+	"io"
+	"net"
+)
+
+type ClientRequestMessage struct {
+	CMD         Command
+	Address     string
+	Port        uint16
+	AddressType Command
+}
+
+type Command = byte
+
+const (
+	IPV4_LENGHT = 4
+	IPV6_LENGHT = 6
+	PORT_LENGHT = 2
+)
+
+const (
+	CmdConnect Command = 0x01
+	CmdBind    Command = 0x02
+	CmdUDP     Command = 0x03
+)
+
+type AddressType = byte
+
+const (
+	TypeIPV4   AddressType = 0x01
+	TypeDoMain AddressType = 0x03
+	TypeIPV6   AddressType = 0x04
+)
+
+func NewClientRequestMessage(conn net.Conn) (*ClientRequestMessage, error) {
+	// 版本 命令 reseved 地址类型
+	buf := make([]byte, 4)
+	if _, err := io.ReadFull(conn, buf); err != nil {
+		return nil, err
+	}
+	version, command, reserved, addType := buf[0], buf[1], buf[2], buf[3]
+	if version != SOCKET_5_VERSION {
+		return nil, ERROR_SOCKET_VERSION_SUPPORTED
+	}
+
+	if command != CmdConnect && command != CmdBind && command != CmdUDP {
+		return nil, ERROR_COMMAND_NOT_SUPPORTED
+	}
+
+	if reserved != ReservedFild {
+		return nil, ERROR_SOCKET_VERSION_SUPPORTED
+	}
+
+	if addType == TypeIPV4 || addType == TypeDoMain {
+		var message ClientRequestMessage
+		message.CMD = command
+		message.AddressType = addType
+
+		//fmt.Printf("请求地址类型为:%v\n", addType)
+
+		switch addType {
+
+		case TypeIPV6:
+			buf = make([]byte, IPV6_LENGHT)
+			if _, err := io.ReadFull(conn, buf); err != nil {
+				return nil, err
+			}
+			ip := net.ParseIP(string(buf))
+			message.Address = ip.String()
+			//fmt.Println("TypeIPV6 地址为:" + ip.String())
+		case TypeIPV4:
+			buf = make([]byte, IPV4_LENGHT)
+			if _, err := io.ReadFull(conn, buf); err != nil {
+				return nil, err
+			}
+			ip := net.IP(buf)
+			message.Address = ip.String()
+			//fmt.Println("TypeIPV4 地址为:" + ip.String())
+		case TypeDoMain:
+
+			if _, err := io.ReadFull(conn, buf[:1]); err != nil {
+				return nil, err
+			}
+
+			domain_length := buf[0]
+			if domain_length > IPV4_LENGHT {
+				buf = make([]byte, domain_length)
+			}
+			if _, err := io.ReadFull(conn, buf[:domain_length]); err != nil {
+				message.Address = string(buf[:domain_length])
+			}
+
+			//fmt.Println("TypeDoMain 地址为:" + message.Address)
+		}
+
+		//读取 端口
+		if _, err := io.ReadFull(conn, buf[:PORT_LENGHT]); err != nil {
+			return nil, err
+		}
+		message.Port = (uint16(buf[0]) << 8) + uint16(buf[1])
+		return &message, nil
+	} else {
+		return nil, ERRADDRESS_TYPE_NOT_SUPPORTED
+	}
+}
+
+type ReplyType = byte
+
+const (
+	ReplySuccess ReplyType = iota
+	ReplyServerFailure
+	ReplyConnectionNotAllowed
+	ReplyNetworkUnreachable
+	ReplyHostUnreachable
+	ReplyConnectionRefused
+	ReplyTTLExpired
+	ReplyCommandNotSupported
+	ReplyAddressTypeNotSupported
+)
+
+func WriteRequestSuccessMessage(conn net.Conn, ip net.IP, port uint16) error {
+
+	addressType := TypeIPV4
+	if len(ip) == IPV6_LENGHT {
+		addressType = TypeIPV6
+	}
+
+	// Write version, reply success, reserved, address type
+	_, err := conn.Write([]byte{SOCKET_5_VERSION, ReplySuccess, ReservedFild, addressType})
+	if err != nil {
+		return err
+	}
+
+	// write bind IP(IPV4/IPV6)
+	if _, err := conn.Write(ip); err != nil {
+		return err
+	}
+	// write bind port
+	buf := make([]byte, 2)
+	buf[0] = byte(port >> 8)
+	buf[1] = byte(port - uint16(buf[0]))
+	_, err = conn.Write(buf)
+	return err
+}
+
+func WriteRequestFailureMessage(conn net.Conn, replyType ReplyType) error {
+	_, err := conn.Write([]byte{SOCKET_5_VERSION, replyType, ReservedFild, TypeIPV4, 0, 0, 0, 0, 0, 0})
+	return err
+}

socket5/socket5.go

@@ -0,0 +1,131 @@
+package socket5
+
+import (
+	"errors"
+	"fmt"
+	"go-socket5-proxy/helper"
+	"io"
+	"log"
+	"net"
+)
+
+type Server interface {
+	Run() error
+}
+
+type Socket5Server struct {
+	Port int64
+	IP   string
+}
+
+func (s *Socket5Server) Run() error {
+	address := fmt.Sprintf("%s:%d", s.IP, s.Port)
+	fmt.Printf("%s:%d \n", s.IP, s.Port)
+	listen, err := helper.CreateListen(address)
+	if err != nil {
+		log.Fatal(err)
+		return err
+	}
+
+	for {
+		conn, err := listen.Accept()
+		if err != nil {
+			log.Printf("连接失败:%s: %s", conn.RemoteAddr(), err)
+		}
+
+		go func() {
+			defer conn.Close()
+			err = handleConnection(conn)
+			if err != nil {
+				//log.Printf("处理连接 handleConnection %s: %s", conn.RemoteAddr(), err)
+			}
+
+		}()
+
+	}
+}
+
+// 处理连接 handleConnection
+func handleConnection(conn net.Conn) error {
+
+	//协商过程
+	if err := auth(conn); err != nil {
+		return err
+	}
+
+	//请求过程
+	targetConn, err := request(conn)
+	if err != nil {
+		return err
+	}
+	if targetConn == nil {
+		return nil
+	}
+	//转发过程
+	return forward(conn, targetConn)
+}
+
+func forward(conn net.Conn, targetConn net.Conn) error {
+	defer targetConn.Close()
+	go io.Copy(targetConn, conn)
+	_, err := io.Copy(conn, targetConn)
+	return err
+}
+
+func request(conn net.Conn) (net.Conn, error) {
+	message, err := NewClientRequestMessage(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	//检查命令是否支持
+	if message.CMD != CmdConnect {
+		return nil, WriteRequestFailureMessage(conn, ReplyCommandNotSupported)
+	}
+
+	//ipv6
+	if message.AddressType == TypeIPV6 {
+		return nil, WriteRequestFailureMessage(conn, ReplyAddressTypeNotSupported)
+	}
+
+	//请求访问目标服务器
+	addres := fmt.Sprintf("%s:%d", message.Address, message.Port)
+	//fmt.Printf("请求访问目标服务器:%v\n", message.AddressType)
+	targetConn, err := net.Dial("tcp", addres)
+	if err != nil {
+		return nil, WriteRequestFailureMessage(conn, ReplyConnectionRefused)
+	}
+
+	//发送成功
+	addrValue := targetConn.LocalAddr()
+	addr := addrValue.(*net.TCPAddr)
+
+	if targetConn == nil {
+		fmt.Printf("targetConn is nil :" + addr.IP.String())
+	}
+
+	return targetConn, WriteRequestSuccessMessage(conn, addr.IP, uint16(addr.Port))
+}
+
+func auth(conn net.Conn) error {
+	client, err := NewClientAuthMessage(conn)
+	if err != nil {
+		return err
+	}
+	//log.Println(client.Version, client.NMethods, client.Methods)
+
+	// 是否支持 no-auth
+	var accept_table bool
+	for _, method := range client.Methods {
+		if method == Method_NO_AUTH {
+			accept_table = true
+		}
+	}
+
+	if !accept_table {
+		NewServerAuthMessage(conn, Method_NO_ACCEPT_TABLE)
+		return errors.New("方法不支持 not auth")
+	}
+
+	return NewServerAuthMessage(conn, Method_NO_AUTH)
+}