使用自定义流程实现网关协议解析转发功能

cmd/server/main.go

@@ -0,0 +1,396 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/binary"
+	"github.com/joho/godotenv"
+	"github.com/pkg/errors"
+	"io"
+	"log/slog"
+	"net"
+	"os"
+	"proxy-server/pkg/socks5"
+	"proxy-server/pkg/utils"
+	"proxy-server/server/orm"
+	"proxy-server/server/web/app/models"
+	"strconv"
+	"time"
+)
+
+var connMap = make(map[string]socks5.ProxyData)
+
+func main() {
+	slog.SetLogLoggerLevel(slog.LevelDebug)
+
+	// 初始化环境变量
+	err := godotenv.Load()
+	if err != nil {
+		slog.Debug("没有本地环境变量文件")
+	}
+
+	orm.Init()
+
+	go startControlTun()
+	go startDataTun()
+	select {}
+}
+
+func startDataTun() {
+	dataPort := os.Getenv("APP_DATA_PORT")
+	if dataPort == "" {
+		panic("环境变量 APP_DATA_PORT 未设置")
+	}
+
+	slog.Info("监听数据端口 " + dataPort)
+	lData, err := net.Listen("tcp", ":"+dataPort)
+	if err != nil {
+		slog.Error("listen error", err)
+		return
+	}
+	defer lData.Close()
+
+	for {
+		conn, err := lData.Accept()
+		if err != nil {
+			slog.Error("accept error", err)
+			return
+		}
+		processDataConn(conn)
+	}
+}
+
+func processDataConn(client net.Conn) {
+
+	slog.Info("已建立客户端数据通道 " + client.RemoteAddr().String())
+
+	// 读取 tag
+	tagLen, err := utils.ReadByte(client)
+	if err != nil {
+		slog.Error("read error", err)
+		return
+	}
+	tagBuf, err := utils.ReadBuffer(client, int(tagLen))
+	if err != nil {
+		slog.Error("read error", err)
+		return
+	}
+	tag := string(tagBuf)
+
+	// 找到用户连接
+	data, ok := connMap[tag]
+	if !ok {
+		slog.Error("no such connection")
+		return
+	}
+
+	// 响应用户
+	user := data.Conn
+	socks5.SendSuccess(user, client)
+
+	// 写入目标地址
+	_, err = client.Write([]byte{byte(len(data.Dest))})
+	if err != nil {
+		slog.Error("写入目标地址失败", err)
+		return
+	}
+	_, err = client.Write([]byte(data.Dest))
+	if err != nil {
+		slog.Error("写入目标地址失败", err)
+		return
+	}
+
+	// 数据转发
+	slog.Info("开始数据转发 " + client.RemoteAddr().String() + " <-> " + data.Dest)
+	errCh := make(chan error)
+	go func() {
+		_, err := io.Copy(client, user)
+		if err != nil {
+			slog.Error("processDataConn error c2u", err)
+		}
+		errCh <- err
+	}()
+	go func() {
+		_, err := io.Copy(user, client)
+		if err != nil {
+			slog.Error("processDataConn error u2c", err)
+		}
+		errCh <- err
+	}()
+	<-errCh
+	slog.Info("数据转发结束 " + client.RemoteAddr().String() + " <-> " + data.Dest)
+	defer func() {
+		err := user.Close()
+		if err != nil {
+			slog.Error("close error", err)
+		}
+		err = client.Close()
+		if err != nil {
+			slog.Error("close error", err)
+		}
+	}()
+}
+
+func startControlTun() {
+	ctrlPort := os.Getenv("APP_CTRL_PORT")
+	if ctrlPort == "" {
+		panic("环境变量 APP_CTRL_PORT 未设置")
+	}
+
+	slog.Info("监听控制端口 " + ctrlPort)
+	lControl, err := net.Listen("tcp", ":"+ctrlPort)
+	if err != nil {
+		slog.Error("listen error", err)
+		return
+	}
+	defer lControl.Close()
+
+	for {
+		conn, err := lControl.Accept()
+		if err != nil {
+			slog.Error("accept error", err)
+			return
+		}
+		go processController(conn)
+	}
+}
+
+func processController(controller net.Conn) {
+	defer controller.Close()
+
+	slog.Info("收到客户端控制连接 " + controller.RemoteAddr().String())
+
+	reader := bufio.NewReader(controller)
+
+	// 读取端口
+	portBuf := make([]byte, 2)
+	_, err := io.ReadFull(reader, portBuf)
+	if err != nil {
+		slog.Error("读取转发端口失败", "err", err)
+		return
+	}
+	port := binary.BigEndian.Uint16(portBuf)
+
+	// 新建代理服务
+	slog.Info("新建代理服务", "port", port)
+	proxy, err := socks5.New(&socks5.Config{
+		Name: strconv.Itoa(int(port)),
+		Port: port,
+		AuthMethods: []socks5.Authenticator{
+			&UserPassAuthenticator{},
+			&NoAuthAuthenticator{},
+		},
+	})
+	if err != nil {
+		slog.Error("代理服务创建失败", err)
+		return
+	}
+
+	go func() {
+		err := proxy.Run()
+		if err != nil {
+			slog.Error("代理服务建立失败", err)
+			return
+		}
+	}()
+
+	slog.Info("代理服务已建立", "port", port)
+	for {
+		user := <-proxy.Conn
+		tag := user.Tag()
+		_, err := controller.Write([]byte{byte(len(tag))})
+		if err != nil {
+			slog.Error("write error", err)
+			return
+		}
+		_, err = controller.Write([]byte(tag))
+		slog.Info("已通知客户端建立数据通道")
+		if err != nil {
+			slog.Error("write error", err)
+			return
+		}
+		connMap[tag] = user
+	}
+}
+
+type NoAuthAuthenticator struct {
+}
+
+func (a *NoAuthAuthenticator) Method() socks5.AuthMethod {
+	return socks5.NoAuth
+}
+
+func (a *NoAuthAuthenticator) Authenticate(ctx context.Context, reader io.Reader, writer io.Writer) (*socks5.AuthContext, error) {
+
+	// 检查用户是否在白名单中，如果不在则返回错误
+	conn, ok := writer.(net.Conn)
+	if !ok {
+		return nil, errors.New("noAuth 认证失败，无法获取连接信息")
+	}
+
+	addr := conn.RemoteAddr().String()
+	client, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, errors.Wrap(err, "noAuth 认证失败")
+	}
+	slog.Info("用户的地址为 " + client)
+
+	// 检查此 ip 是否有权限访问目标 node
+	server, ok := ctx.Value("service").(*socks5.Server)
+	if !ok {
+		return nil, errors.New("noAuth 认证失败，无法获取服务信息")
+	}
+
+	node := server.Name
+	slog.Debug(" 客户端 " + client + " 请求连接到 " + node)
+
+	var channels []models.Channel
+	err = orm.DB.
+		Joins("INNER JOIN public.nodes n ON channels.node_id = n.id AND n.name = ?", node).
+		Joins("INNER JOIN public.users u ON channels.user_id = u.id").
+		Joins("INNER JOIN public.user_ips ip ON u.id = ip.user_id AND ip.ip_address = ?", client).
+		Find(&channels).Error
+	if err != nil {
+		return nil, errors.New("noAuth 认证失败，查询用户权限失败")
+	}
+
+	if len(channels) == 0 {
+		return nil, errors.New("noAuth 认证失败，没有权限")
+	}
+	if len(channels) > 1 {
+		slog.Warn(client + " + " + node + "的组合有多个权限结果，这是不应当存在的")
+	}
+
+	channel := channels[0]
+
+	if !channel.AuthIp {
+		return nil, errors.New("noAuth 认证失败，没有权限")
+	}
+
+	if channel.Expiration.Before(time.Now()) {
+		return nil, errors.New("noAuth 认证失败，权限已过期")
+	}
+
+	return &socks5.AuthContext{
+		Method:  socks5.NoAuth,
+		Timeout: 300, // todo
+		Payload: nil,
+	}, nil
+}
+
+type UserPassAuthenticator struct {
+}
+
+func (a *UserPassAuthenticator) Method() socks5.AuthMethod {
+	return socks5.UserPassAuth
+}
+
+func (a *UserPassAuthenticator) Authenticate(ctx context.Context, reader io.Reader, writer io.Writer) (*socks5.AuthContext, error) {
+
+	// 检查版本
+	v, err := utils.ReadByte(reader)
+	if err != nil {
+		return nil, errors.Wrap(err, "读取版本号失败")
+	}
+	if v != socks5.AuthVersion {
+		_, err := writer.Write([]byte{socks5.SocksVersion, socks5.AuthFailure})
+		if err != nil {
+			return nil, errors.Wrap(err, "响应认证失败")
+		}
+		return nil, errors.New("认证版本参数不正确")
+	}
+
+	// 读取账号
+	uLen, err := utils.ReadByte(reader)
+	if err != nil {
+		return nil, errors.Wrap(err, "读取用户名长度失败")
+	}
+	usernameBuf, err := utils.ReadBuffer(reader, int(uLen))
+	if err != nil {
+		return nil, errors.Wrap(err, "读取用户名失败")
+	}
+	username := string(usernameBuf)
+
+	// 读取密码
+	pLen, err := utils.ReadByte(reader)
+	if err != nil {
+		return nil, errors.Wrap(err, "读取密码长度失败")
+	}
+	passwordBuf, err := utils.ReadBuffer(reader, int(pLen))
+	if err != nil {
+		return nil, errors.Wrap(err, "读取密码失败")
+	}
+	password := string(passwordBuf)
+
+	var channels []models.Channel
+	err = orm.DB.
+		Where(&models.Channel{
+			Username: username,
+		}).
+		Find(&channels).Error
+	if err != nil {
+		return nil, errors.Wrap(err, "查询用户失败")
+	}
+
+	if len(channels) == 0 {
+		return nil, errors.New("没有权限")
+	}
+	if len(channels) > 1 {
+		slog.Warn("用户有多个权限结果，这是不应当存在的")
+	}
+	channel := channels[0]
+	if !channel.AuthPass {
+		return nil, errors.New("没有权限")
+	}
+
+	if channel.Expiration.Before(time.Now()) {
+		return nil, errors.New("权限已过期")
+	}
+
+	// 检查密码 todo 哈希
+	if channel.Password != password {
+		return nil, errors.New("密码错误")
+	}
+
+	// 如果用户设置了双验证则检查 ip 是否在白名单中
+	if channel.AuthIp {
+		conn, ok := writer.(net.Conn)
+		if !ok {
+			return nil, errors.New("无法获取连接信息")
+		}
+
+		addr := conn.RemoteAddr().String()
+		client, _, err := net.SplitHostPort(addr)
+		if err != nil {
+			return nil, errors.Wrap(err, "无法获取连接信息")
+		}
+
+		slog.Info("用户的地址为 " + client)
+		var ips []models.UserIp
+		err = orm.DB.
+			Where(&models.UserIp{
+				UserId:    channel.UserId,
+				IpAddress: client,
+			}).
+			Find(&ips).Error
+		if err != nil {
+			return nil, errors.Wrap(err, "查询用户 ip 失败")
+		}
+
+		if len(ips) == 0 {
+			return nil, errors.New("没有权限")
+		}
+	}
+
+	_, err = writer.Write([]byte{socks5.AuthVersion, socks5.AuthSuccess})
+	if err != nil {
+		slog.Error("响应认证失败", err)
+		return nil, err
+	}
+
+	return &socks5.AuthContext{
+		Method:  socks5.UserPassAuth,
+		Timeout: 300, // todo
+		Payload: nil,
+	}, nil
+}