fixup! ble-dongle: Get USB echo running

nucleo-wb55-dongle-ble/Core/Src/main.c

@@ -23,7 +23,7 @@
 
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
-
+#include "usbd_cdc_if.h"
 /* USER CODE END Includes */
 
 /* Private typedef -----------------------------------------------------------*/
@@ -55,7 +55,9 @@ static void MX_GPIO_Init(void);
 
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
-
+void usb_receive(uint8_t *buf, uint32_t *len) {
+  CDC_Transmit_FS(buf, *len);  // echo
+}
 /* USER CODE END 0 */
 
 /**

nucleo-wb55-dongle-ble/USB_Device/App/usbd_cdc_if.c

@@ -129,7 +129,7 @@ static int8_t CDC_Receive_FS(uint8_t* pbuf, uint32_t *Len);
 static int8_t CDC_TransmitCplt_FS(uint8_t *pbuf, uint32_t *Len, uint8_t epnum);
 
 /* USER CODE BEGIN PRIVATE_FUNCTIONS_DECLARATION */
-
+__weak void usb_receive(uint8_t *buf, uint32_t *len) {}
 /* USER CODE END PRIVATE_FUNCTIONS_DECLARATION */
 
 /**
@@ -270,7 +270,7 @@ static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
   /* USER CODE BEGIN 6 */
   USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
   USBD_CDC_ReceivePacket(&hUsbDeviceFS);
-  CDC_Transmit_FS(Buf, *Len);  // echo
+  usb_receive(Buf, Len);
   return (USBD_OK);
   /* USER CODE END 6 */
 }

nucleo-wb55-dongle-ble/USB_Device/App/usbd_cdc_if.h

@@ -110,7 +110,7 @@ extern USBD_CDC_ItfTypeDef USBD_Interface_fops_FS;
 uint8_t CDC_Transmit_FS(uint8_t* Buf, uint16_t Len);
 
 /* USER CODE BEGIN EXPORTED_FUNCTIONS */
-
+__weak void usb_receive(uint8_t *buf, uint32_t *len);
 /* USER CODE END EXPORTED_FUNCTIONS */
 
 /**