[HID] Improved checks in getDescriptor() method

Author: cmaglie

hardware/arduino/avr/cores/arduino/USBCore.h

@@ -49,8 +49,9 @@
 #define REQUEST_OTHER			0x03
 #define REQUEST_RECIPIENT		0x03
 
-#define REQUEST_DEVICETOHOST_CLASS_INTERFACE  (REQUEST_DEVICETOHOST + REQUEST_CLASS + REQUEST_INTERFACE)
-#define REQUEST_HOSTTODEVICE_CLASS_INTERFACE  (REQUEST_HOSTTODEVICE + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_DEVICETOHOST_CLASS_INTERFACE    (REQUEST_DEVICETOHOST + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_HOSTTODEVICE_CLASS_INTERFACE    (REQUEST_HOSTTODEVICE + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_DEVICETOHOST_STANDARD_INTERFACE (REQUEST_DEVICETOHOST + REQUEST_STANDARD + REQUEST_INTERFACE)
 
 //	Class requests
 

hardware/arduino/avr/libraries/HID/HID.cpp

@@ -40,9 +40,12 @@ int HID_::getInterface(uint8_t* interfaceCount)
 
 int HID_::getDescriptor(USBSetup& setup)
 {
-	if (pluggedInterface != setup.wIndex) {
-		return 0;
-	}
+	// Check if this is a HID Class Descriptor request
+	if (setup.bmRequestType != REQUEST_DEVICETOHOST_STANDARD_INTERFACE) { return 0; }
+	if (setup.wValueH != HID_REPORT_DESCRIPTOR_TYPE) { return 0; }
+
+	// In a HID Class Descriptor wIndex cointains the interface number
+	if (setup.wIndex != pluggedInterface) { return 0; }
 
 	int total = 0;
 	HIDDescriptorListNode* node;