Initial commit

core/connect/fake_tcp.go

@@ -0,0 +1,219 @@
+package connect
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+// FakeTCPConn FakeTCP 连接（UDP 包封装为 TCP 流）
+type FakeTCPConn struct {
+	conn       net.Conn
+	mu         sync.Mutex
+	closed     bool
+	readBuffer []byte
+}
+
+// NewFakeTCPConn 创建 FakeTCP 连接
+func NewFakeTCPConn(conn net.Conn) *FakeTCPConn {
+	return &FakeTCPConn{
+		conn:       conn,
+		readBuffer: make([]byte, 0),
+	}
+}
+
+// Read 读取数据（带长度前缀解析）
+func (c *FakeTCPConn) Read(b []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// 如果缓冲区有数据，直接返回
+	if len(c.readBuffer) > 0 {
+		n := copy(b, c.readBuffer)
+		c.readBuffer = c.readBuffer[n:]
+		return n, nil
+	}
+
+	// 读取长度前缀（4 字节）
+	var length uint32
+	if err := binary.Read(c.conn, binary.BigEndian, &length); err != nil {
+		return 0, err
+	}
+
+	// 限制最大长度（防止恶意攻击）
+	if length > 65535 {
+		return 0, fmt.Errorf("packet too large: %d bytes", length)
+	}
+
+	// 读取实际数据
+	data := make([]byte, length)
+	if _, err := io.ReadFull(c.conn, data); err != nil {
+		return 0, err
+	}
+
+	// 返回请求的数据
+	n := copy(b, data)
+	if n < len(data) {
+		// 剩余数据存入缓冲区
+		c.readBuffer = data[n:]
+	}
+
+	return n, nil
+}
+
+// Write 写入数据（添加 4 字节长度前缀）
+func (c *FakeTCPConn) Write(b []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.closed {
+		return 0, fmt.Errorf("connection closed")
+	}
+
+	// 写入长度前缀
+	length := uint32(len(b))
+	if err := binary.Write(c.conn, binary.BigEndian, length); err != nil {
+		return 0, err
+	}
+
+	// 写入实际数据
+	n, err := c.conn.Write(b)
+	return n, err
+}
+
+// Close 关闭连接
+func (c *FakeTCPConn) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.closed = true
+	return c.conn.Close()
+}
+
+// LocalAddr 本地地址
+func (c *FakeTCPConn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+// RemoteAddr 远程地址
+func (c *FakeTCPConn) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+// SetDeadline 设置截止时间
+func (c *FakeTCPConn) SetDeadline(t time.Time) error {
+	return c.conn.SetDeadline(t)
+}
+
+// SetReadDeadline 设置读截止时间
+func (c *FakeTCPConn) SetReadDeadline(t time.Time) error {
+	return c.conn.SetReadDeadline(t)
+}
+
+// SetWriteDeadline 设置写截止时间
+func (c *FakeTCPConn) SetWriteDeadline(t time.Time) error {
+	return c.conn.SetWriteDeadline(t)
+}
+
+// DialFakeTCP 拨号 FakeTCP 连接
+func DialFakeTCP(ctx context.Context, network, addr string, logger *zap.Logger) (net.Conn, error) {
+	logger.Debug("dialing FakeTCP", zap.String("addr", addr))
+
+	// 建立 TCP 连接
+	conn, err := (&net.Dialer{}).DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to dial TCP: %w", err)
+	}
+
+	// 包装为 FakeTCP 连接
+	return NewFakeTCPConn(conn), nil
+}
+
+// ListenFakeTCP 监听 FakeTCP 端口
+func ListenFakeTCP(network, addr string, logger *zap.Logger) (net.Listener, error) {
+	logger.Info("listening FakeTCP", zap.String("addr", addr))
+
+	// 监听 TCP 端口
+	listener, err := net.Listen(network, addr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to listen TCP: %w", err)
+	}
+
+	return &fakeTCPListener{
+		Listener: listener,
+		logger:   logger,
+	}, nil
+}
+
+// fakeTCPListener FakeTCP 监听器
+type fakeTCPListener struct {
+	net.Listener
+	logger *zap.Logger
+}
+
+// Accept 接受连接并包装为 FakeTCPConn
+func (l *fakeTCPListener) Accept() (net.Conn, error) {
+	conn, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+
+	l.logger.Debug("accepted FakeTCP connection", zap.String("addr", conn.RemoteAddr().String()))
+	return NewFakeTCPConn(conn), nil
+}
+
+// FakeTCPFactory FakeTCP 传输工厂
+type FakeTCPFactory struct {
+	logger *zap.Logger
+}
+
+// NewFakeTCPFactory 创建 FakeTCP 工厂
+func NewFakeTCPFactory(logger *zap.Logger) *FakeTCPFactory {
+	return &FakeTCPFactory{
+		logger: logger,
+	}
+}
+
+// Layer 返回传输层类型
+func (f *FakeTCPFactory) Layer() Layer {
+	return LayerFakeTCP
+}
+
+// Name 返回名称
+func (f *FakeTCPFactory) Name() string {
+	return "FakeTCP"
+}
+
+// Dial 建立 FakeTCP 连接
+func (f *FakeTCPFactory) Dial(ctx context.Context, config *DialConfig) (net.Conn, error) {
+	f.logger.Info("开始建立 FakeTCP 连接",
+		zap.String("peer_id", config.PeerID))
+
+	// 1. 解析对端地址（PeerID 格式应为 "ip:port"）
+	if config.PeerID == "" {
+		return nil, fmt.Errorf("PeerID 为空")
+	}
+
+	// 2. 建立 TCP 连接
+	dialer := &net.Dialer{Timeout: config.Timeout}
+	conn, err := dialer.DialContext(ctx, "tcp", config.PeerID)
+	if err != nil {
+		return nil, fmt.Errorf("TCP 连接失败：%w", err)
+	}
+
+	// 3. 包装为 FakeTCP 连接（UDP 包封装为 TCP 流）
+	fakeConn := NewFakeTCPConn(conn)
+
+	f.logger.Info("FakeTCP 连接建立成功",
+		zap.String("peer_id", config.PeerID),
+		zap.String("local_addr", conn.LocalAddr().String()),
+		zap.String("remote_addr", conn.RemoteAddr().String()))
+
+	return fakeConn, nil
+}