HIDCheckReport.c   [plain text]


/*
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
	File:		HIDCheckReport.c

	Contains:	xxx put contents here xxx

	Version:	xxx put version here xxx

	Copyright:	 1999-2001 by Apple Computer, Inc., all rights reserved.

	File Ownership:

		DRI:				xxx put dri here xxx

		Other Contact:		xxx put other contact here xxx

		Technology:			xxx put technology here xxx

	Writers:

		(DF)	David Ferguson
		(KH)	Keithen Hayenga
		(BWS)	Brent Schorsch

	Change History (most recent first):

	  <USB3>	  1/2/01	DF		Change length checking to check for the minimum size instead of
									the "exact" size.
	  <USB2>	12/12/00	KH		Correcting cast of void *
	  <USB1>	  3/5/99	BWS		first checked in
*/

#include "HIDLib.h"

/*
 *------------------------------------------------------------------------------
 *
 * HIDCheckReport - Check the Report ID, Type, and Length
 *
 *	 Input:
 *			  reportType		   - The Specified Report Type
 *			  ptPreparsedData		- The Preparsed Data
 *			  ptReportItem			- The Report Item
 *			  psReport				- The Report
 *			  iReportLength			- The Report Length
 *	 Output:
 *	 Returns:
 *			  kHIDSuccess, HidP_IncompatibleReportID,
 *			  kHIDInvalidReportLengthErr, kHIDInvalidReportTypeErr
 *
 *------------------------------------------------------------------------------
*/
OSStatus HIDCheckReport(HIDReportType reportType, HIDPreparsedDataRef preparsedDataRef,
							 HIDReportItem *ptReportItem, void *report, ByteCount iReportLength)
{
	HIDPreparsedDataPtr ptPreparsedData = (HIDPreparsedDataPtr) preparsedDataRef;
	int reportID, reportIndex;
	int iExpectedLength;
	Byte * psReport = (Byte *)report;
/*
 *	See if this is the correct Report ID
*/
	reportID = psReport[0]&0xFF;
	if ((ptPreparsedData->reportCount > 1)
	 && (reportID != ptReportItem->globals.reportID))
		return kHIDIncompatibleReportErr;
/*
 *	See if this is the correct ReportType
*/
	if (reportType != ptReportItem->reportType)
		return kHIDIncompatibleReportErr;
/*
 *	Check for the correct Length for the Type
*/
	reportIndex = ptReportItem->globals.reportIndex;
	switch(reportType)
	{
		case kHIDInputReport:
			iExpectedLength = (ptPreparsedData->reports[reportIndex].inputBitCount + 7)/8;
			break;
		case kHIDOutputReport:
			iExpectedLength = (ptPreparsedData->reports[reportIndex].outputBitCount + 7)/8;
			break;
		case kHIDFeatureReport:
			iExpectedLength = (ptPreparsedData->reports[reportIndex].featureBitCount + 7)/8;
			break;
		default:
			return kHIDInvalidReportTypeErr;
	}
	if (iExpectedLength > iReportLength)
		return kHIDInvalidReportLengthErr;
	return kHIDSuccess;
}