refactor: 为SMB2插件添加包控制功能

- 在testCredential和detectProtocol方法中添加包控制检查
- 统一错误处理和包计数逻辑
- 确保所有TCP连接遵循发包限制

plugins/services/smb2.go

@@ -105,6 +105,11 @@ func (p *Smb2Plugin) Scan(ctx context.Context, info *common.HostInfo) *ScanResul
 
 // testCredential 测试单个凭据 - 简化的SMB2协议检测
 func (p *Smb2Plugin) testCredential(ctx context.Context, info *common.HostInfo, cred Credential) bool {
+	// 检查发包限制
+	if canSend, _ := common.CanSendPacket(); !canSend {
+		return false
+	}
+	
 	// 基于TCP连接的简单SMB2检测
 	timeoutCtx, cancel := context.WithTimeout(ctx, time.Duration(common.Timeout)*time.Second)
 	defer cancel()
@@ -112,8 +117,10 @@ func (p *Smb2Plugin) testCredential(ctx context.Context, info *common.HostInfo,
 	dialer := &net.Dialer{}
 	conn, err := dialer.DialContext(timeoutCtx, "tcp", fmt.Sprintf("%s:445", info.Host))
 	if err != nil {
+		common.IncrementTCPFailedPacketCount()
 		return false
 	}
+	common.IncrementTCPSuccessPacketCount()
 	defer conn.Close()
 
 	// 发送SMB2协商请求
@@ -153,10 +160,17 @@ func (p *Smb2Plugin) testCredential(ctx context.Context, info *common.HostInfo,
 
 // detectProtocol 检测SMB2协议信息
 func (p *Smb2Plugin) detectProtocol(ctx context.Context, info *common.HostInfo) string {
-	conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:445", info.Host), 5*time.Second)
-	if err != nil {
+	// 检查发包限制
+	if canSend, _ := common.CanSendPacket(); !canSend {
 		return ""
 	}
+	
+	conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:445", info.Host), 5*time.Second)
+	if err != nil {
+		common.IncrementTCPFailedPacketCount()
+		return ""
+	}
+	common.IncrementTCPSuccessPacketCount()
 	defer conn.Close()
 
 	// 发送SMB2协商请求获取版本信息