iokit/Families/IOHIDSystem/IOHIDDescriptorParser/HIDCheckReport.c

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23         File:           HIDCheckReport.c
  24
  25         Contains:       xxx put contents here xxx
  26
  27         Version:        xxx put version here xxx
  28
  29         Copyright:      © 1999-2001 by Apple Computer, Inc., all rights reserved.
  30
  31         File Ownership:
  32
  33                 DRI:                            xxx put dri here xxx
  34
  35                 Other Contact:          xxx put other contact here xxx
  36
  37                 Technology:                     xxx put technology here xxx
  38
  39         Writers:
  40
  41                 (DF)    David Ferguson
  42                 (KH)    Keithen Hayenga
  43                 (BWS)   Brent Schorsch
  44
  45         Change History (most recent first):
  46
  47           <USB3>          1/2/01        DF              Change length checking to check for the minimum size instead of
  48                                                                         the "exact" size.
  49           <USB2>        12/12/00        KH              Correcting cast of void *
  50           <USB1>          3/5/99        BWS             first checked in
  51 */
  52
  53 #include "HIDLib.h"
  54
  55 /*
  56  *------------------------------------------------------------------------------
  57  *
  58  * HIDCheckReport - Check the Report ID, Type, and Length
  59  *
  60  *       Input:
  61  *                        reportType               - The Specified Report Type
  62  *                        ptPreparsedData               - The Preparsed Data
  63  *                        ptReportItem                  - The Report Item
  64  *                        psReport                              - The Report
  65  *                        iReportLength                 - The Report Length
  66  *       Output:
  67  *       Returns:
  68  *                        kHIDSuccess, HidP_IncompatibleReportID,
  69  *                        kHIDInvalidReportLengthErr, kHIDInvalidReportTypeErr
  70  *
  71  *------------------------------------------------------------------------------
  72 */
  73 OSStatus HIDCheckReport(HIDReportType reportType, HIDPreparsedDataRef preparsedDataRef,
  74                                                          HIDReportItem *ptReportItem, void *report, UInt32 iReportLength)
  75 {
  76         HIDPreparsedDataPtr ptPreparsedData = (HIDPreparsedDataPtr) preparsedDataRef;
  77         int reportID, reportIndex;
  78         int iExpectedLength;
  79         Byte * psReport = (Byte *)report;
  80 /*
  81  *      See if this is the correct Report ID
  82 */
  83         reportID = psReport[0]&0xFF;
  84         if ((ptPreparsedData->reportCount > 1)
  85          && (reportID != ptReportItem->globals.reportID))
  86                 return kHIDIncompatibleReportErr;
  87 /*
  88  *      See if this is the correct ReportType
  89 */
  90         if (reportType != ptReportItem->reportType)
  91                 return kHIDIncompatibleReportErr;
  92 /*
  93  *      Check for the correct Length for the Type
  94 */
  95         reportIndex = ptReportItem->globals.reportIndex;
  96         switch(reportType)
  97         {
  98                 case kHIDInputReport:
  99                         iExpectedLength = (ptPreparsedData->reports[reportIndex].inputBitCount + 7)/8;
 100                         break;
 101                 case kHIDOutputReport:
 102                         iExpectedLength = (ptPreparsedData->reports[reportIndex].outputBitCount + 7)/8;
 103                         break;
 104                 case kHIDFeatureReport:
 105                         iExpectedLength = (ptPreparsedData->reports[reportIndex].featureBitCount + 7)/8;
 106                         break;
 107                 default:
 108                         return kHIDInvalidReportTypeErr;
 109         }
 110         if (iExpectedLength > iReportLength)
 111                 return kHIDInvalidReportLengthErr;
 112         return kHIDSuccess;
 113 }