Changed the parameters and behaviour of the USB_GetDeviceConfigDescriptor() function so that it now performs size checks and data validations internally, to simplify user code.

4 files changed, 54 insertions, 29 deletions

diff --git a/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.c b/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.c
index 47982b806..4c6fbfdab 100644
--- a/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.c
+++ b/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.c
@@ -31,9 +31,11 @@
 #include "ConfigDescriptor.h"

 

 #if defined(USB_CAN_BE_HOST)

-uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr)

+uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr,

+                                      void* BufferPtr, uint16_t BufferSize)

 {

 	uint8_t ErrorCode;

+	uint8_t ConfigHeader[sizeof(USB_Descriptor_Configuration_Header_t)];

 

 	USB_ControlRequest = (USB_Request_Header_t)

 		{

@@ -46,26 +48,27 @@ uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const Conf
 	

 	Pipe_SelectPipe(PIPE_CONTROLPIPE);

 

-	if (BufferPtr == NULL)

-	{

-		uint8_t ConfigHeader[sizeof(USB_Descriptor_Configuration_Header_t)];

+	if ((ErrorCode = USB_Host_SendControlRequest(ConfigHeader)) != HOST_SENDCONTROL_Successful)

+	  return ErrorCode;

 

-		ErrorCode      = USB_Host_SendControlRequest(ConfigHeader);

+	#if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES)

+	*ConfigSizePtr = DESCRIPTOR_CAST(ConfigHeader, USB_Descriptor_Configuration_Header_t).TotalConfigurationSize;

+	#else

+	*ConfigSizePtr = DESCRIPTOR_CAST(ConfigHeader, USB_Descriptor_Configuration_Header_t).wTotalLength;		

+	#endif

 

-		#if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES)

-		*ConfigSizePtr = DESCRIPTOR_CAST(ConfigHeader, USB_Descriptor_Configuration_Header_t).TotalConfigurationSize;

-		#else

-		*ConfigSizePtr = DESCRIPTOR_CAST(ConfigHeader, USB_Descriptor_Configuration_Header_t).wTotalLength;		

-		#endif

-	}

-	else

-	{

-		USB_ControlRequest.wLength = *ConfigSizePtr;

-		

-		ErrorCode      = USB_Host_SendControlRequest(BufferPtr);				

-	}

+	if (*ConfigSizePtr > BufferSize)

+	  return HOST_GETCONFIG_BuffOverflow;

+	  

+	USB_ControlRequest.wLength = *ConfigSizePtr;

+	

+	if ((ErrorCode = USB_Host_SendControlRequest(BufferPtr)) != HOST_SENDCONTROL_Successful)

+	  return ErrorCode;

 

-	return ErrorCode;

+	if (DESCRIPTOR_TYPE(BufferPtr) != DTYPE_Configuration)

+	  return HOST_GETCONFIG_InvalidData;

+	

+	return HOST_GETCONFIG_Successful;

 }

 #endif

 

diff --git a/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h b/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h
index a9b0b1423..8c4e2c2db 100644
--- a/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h
+++ b/LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h
@@ -163,6 +163,23 @@
 			uint8_t USB_GetNextDescriptorComp(uint16_t* BytesRem, uint8_t** CurrConfigLoc, ConfigComparatorPtr_t ComparatorRoutine);

 			

 		/* Enums: */

+			enum USB_Host_GetConfigDescriptor_ErrorCodes_t

+			{

+				HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor */

+				HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration

+				                                        * descriptor

+				                                        */

+				HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request */

+				HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration

+				                                        * descriptor

+				                                        */

+				HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out */

+				HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated

+				                                        * buffer

+				                                        */

+				HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data */

+			};

+		

 			/** Enum for return values of a descriptor comparator function. */

 			enum DSearch_Return_ErrorCodes_t

 			{

@@ -181,22 +198,19 @@
 			};

 	

 		/* Function Prototypes: */

-			/** Retrieves the configuration descriptor data or size from an attached device via a standard request.

+			/** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,

+			 *  including validity and size checking to prevent a buffer overflow.

 			 *

 			 *  \param[in] ConfigNumber  Device configuration descriptor number to fetch from the device (usually set to 1 for

 			 *                           single configuration devices)

+			 *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for storing the retrieved configuration descriptor size

+			 *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data.

+			 *  \param[out] BufferSize  Size of the allocated buffer where the configuration descriptor is to be stored

 			 *

-			 *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for either storing or retrieving the configuration

-			 *                                descriptor size

-			 *

-			 *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data. If this is

-			 *                         NULL, the size of the configuration descriptor will be retrieved instead and

-			 *                         placed in the variable pointed to by ConfigSizePtr. If this is non-NULL, the number

-			 *                         of bytes indicated by ConfigSizePtr of the configuration descriptor will be loaded

-			 *                         into the buffer

+			 *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum

 			 */

-			uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr)

-			                                      ATTR_NON_NULL_PTR_ARG(2);

+			uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr,

+			                                      uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2, 3);

 

 			/** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.

 			 *  The bytes remaining value is automatically decremented.

diff --git a/LUFA/ManPages/ChangeLog.txt b/LUFA/ManPages/ChangeLog.txt
index 8530f705f..1750bfaeb 100644
--- a/LUFA/ManPages/ChangeLog.txt
+++ b/LUFA/ManPages/ChangeLog.txt
@@ -29,6 +29,8 @@
   *  - Added new "Common" section to the class drivers, to hold all mode-independant definitions for clarity

   *  - Moved SCSI command/sense constants into the Mass Storage Class driver, instead of the user-code

   *  - Altered the SCSI commands in the LowLevel Mass Storage Host to save on FLASH space by reducing function calls

+  *  - Changed the parameters and behaviour of the USB_GetDeviceConfigDescriptor() function so that it now performs size checks

+  *    and data validations internally, to simplify user code

   *

   *  <b>Fixed:</b>

   *  - Fixed possible lockup in the CDC device class driver, when the host sends data that is a multiple of the

diff --git a/LUFA/ManPages/MigrationInformation.txt b/LUFA/ManPages/MigrationInformation.txt
index d83043182..9527a373c 100644
--- a/LUFA/ManPages/MigrationInformation.txt
+++ b/LUFA/ManPages/MigrationInformation.txt
@@ -19,6 +19,12 @@
  *    - The SPI_Init() routine's parameters have changed, so that the clock polarity and data sampling modes can be set. See

  *      the SPI_Init() function documentation for more details

  *

+ *  <b>Host Mode</b>

+ *    - The \ref USB_GetDeviceConfigDescriptor() function's parameters and behaviour has changed; the user is required to

+ *      preallocate the largest allowable buffer, and pass the size of the buffer to the function. This allows for a single

+ *      call to the function to retrieve, size check and validate the Configuration Descriptor rather than having the user

+ *      application perform these intermediatary steps.

+ *

  * \section Sec_Migration090810 Migrating from 090605 to 090810

  *

  *  <b>All</b>