优化项目机构和服务端协程控制逻辑

server/pkg/socks5/server.go

@@ -0,0 +1,199 @@
+package socks5
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"log/slog"
+	"net"
+	"os"
+	"proxy-server/pkg/utils"
+	"strconv"
+)
+
+const (
+	SocksVersion = byte(5)
+)
+
+type Config struct {
+	Name string
+
+	Host string
+	Port uint16
+
+	// 认证方法
+	AuthMethods []Authenticator
+
+	// 域名解析
+	Resolver NameResolver
+
+	// 自定义认证规则
+	Rules RuleSet
+
+	// 地址重写
+	Rewriter AddressRewriter
+
+	// 用于 bind 和 associate
+	BindIP net.IP
+
+	// Logger
+	Logger *log.Logger
+
+	// 自定义连接流程
+	Dial func(network, addr string) (net.Conn, error)
+}
+
+type Server struct {
+	config *Config
+	Name   string
+	Port   uint16
+	Conn   chan ProxyData
+}
+
+// New 创建服务器
+func New(conf *Config) (*Server, error) {
+	if len(conf.AuthMethods) == 0 {
+		return nil, ConfigError("认证方法不能为空")
+	}
+
+	if conf.Resolver == nil {
+		conf.Resolver = DNSResolver{}
+	}
+
+	if conf.Rules == nil {
+		conf.Rules = PermitAll()
+	}
+
+	if conf.Logger == nil {
+		conf.Logger = log.New(os.Stdout, "", log.LstdFlags)
+	}
+
+	if conf.Dial == nil {
+		conf.Dial = func(network, addr string) (net.Conn, error) {
+			return net.Dial(network, addr)
+		}
+	}
+
+	return &Server{
+		config: conf,
+		Name:   conf.Name,
+		Port:   conf.Port,
+		Conn:   make(chan ProxyData, 100),
+	}, nil
+}
+
+// Run 监听端口
+func (server *Server) Run() error {
+	host := server.config.Host
+	port := server.config.Port
+	addr := net.JoinHostPort(host, strconv.Itoa(int(port)))
+
+	slog.Info("启动 socks5 代理服务")
+
+	listener, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+	defer closeListener(listener)
+
+	slog.Info("代理服务已启动，正在监听端口 " + addr)
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			slog.Error("客户端连接失败", err)
+			continue
+		}
+
+		go func() {
+			err := server.serve(conn)
+			if err != nil {
+				slog.Error("连接异常退出", err)
+			}
+		}()
+	}
+}
+
+// serve 建立连接
+func (server *Server) serve(conn net.Conn) error {
+	slog.Info("收到来自" + conn.RemoteAddr().String() + "的连接")
+
+	reader := bufio.NewReader(conn)
+
+	// 认证
+	slog.Debug("开始认证流程")
+	authContext, err := server.authenticate(reader, conn)
+	if err != nil {
+		conn.Close()
+		slog.Error("认证失败", err)
+		return err
+	} else {
+		slog.Debug("认证完成")
+	}
+
+	// 处理连接请求
+	slog.Debug("处理连接请求")
+	request, err := server.request(reader, conn)
+	if err != nil {
+		slog.Error("连接请求处理失败", err)
+		return err
+	} else {
+		slog.Debug("连接请求处理完成")
+	}
+
+	request.AuthContext = authContext
+	client, ok := conn.RemoteAddr().(*net.TCPAddr)
+	if !ok {
+		return fmt.Errorf("获取客户端地址失败")
+	}
+
+	request.RemoteAddr = &AddrSpec{
+		IP:   client.IP,
+		Port: client.Port,
+	}
+
+	// 处理请求
+	slog.Debug("开始代理流量")
+	err = server.handle(request, conn)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// checkVersion 检查客户端版本
+func checkVersion(reader io.Reader) error {
+	version, err := utils.ReadByte(reader)
+	if err != nil {
+		return err
+	}
+
+	slog.Debug("客户端请求版本", "version", version)
+
+	if version != SocksVersion {
+		return errors.New("客户端版本不兼容")
+	}
+
+	return nil
+}
+
+// closeListener 关闭监听并处理可能的错误
+func closeListener(listener net.Listener) {
+	err := listener.Close()
+	if err != nil {
+		slog.Info("结束监听端口")
+	}
+}
+
+// closeConnection 关闭连接并处理可能的错误
+func closeConnection(conn net.Conn) {
+	err := conn.Close()
+	if err != nil {
+		slog.Error("连接异常关闭", err)
+	} else {
+		slog.Info("已关闭来自" + conn.RemoteAddr().String() + "的连接")
+	}
+}