[PATCH 1/6] hidclass.sys: Simplify signed / unsigned item value parsing.
Rémi Bernon
rbernon at codeweavers.com
Thu Jun 17 03:20:16 CDT 2021
Signed-off-by: Rémi Bernon <rbernon at codeweavers.com>
---
dlls/hidclass.sys/descriptor.c | 109 ++++++++++++++-------------------
1 file changed, 46 insertions(+), 63 deletions(-)
diff --git a/dlls/hidclass.sys/descriptor.c b/dlls/hidclass.sys/descriptor.c
index 65c2f9aadae..cf0e8436b91 100644
--- a/dlls/hidclass.sys/descriptor.c
+++ b/dlls/hidclass.sys/descriptor.c
@@ -256,29 +256,6 @@ static void debug_print_preparsed(WINE_HIDP_PREPARSED_DATA *data)
}
}
-static int getValue(int bsize, int source, BOOL allow_negative)
-{
- int mask = 0xff;
- int negative = 0x80;
- int outofrange = 0x100;
- int value;
- unsigned int i;
-
- if (bsize == 4)
- return source;
-
- for (i = 1; i < bsize; i++)
- {
- mask = (mask<<8) + 0xff;
- negative = (negative<<8);
- outofrange = (outofrange<<8);
- }
- value = (source&mask);
- if (allow_negative && value&negative)
- value = -1 * (outofrange - value);
- return value;
-}
-
static void parse_io_feature(unsigned int bSize, int itemVal, int bTag,
unsigned int *feature_index,
struct feature *feature)
@@ -342,17 +319,35 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
int usages_top = 0;
USAGE usages[256];
int i;
+ UINT32 value;
+ INT32 signed_value;
for (i = index; i < length;)
{
BYTE b0 = descriptor[i++];
- int bSize = b0 & 0x03;
+ int size = b0 & 0x03;
int bType = (b0 >> 2) & 0x03;
int bTag = (b0 >> 4) & 0x0F;
- bSize = (bSize == 3) ? 4 : bSize;
- if (bType == TAG_TYPE_RESERVED && bTag == 0x0F && bSize == 2 &&
- i + 2 < length)
+ if (size == 3) size = 4;
+ if (length - i < size)
+ {
+ ERR("Need %d bytes to read item value\n", size);
+ return -1;
+ }
+
+ if (size == 0) signed_value = value = 0;
+ else if (size == 1) signed_value = (INT8)(value = *(UINT8 *)(descriptor + i));
+ else if (size == 2) signed_value = (INT16)(value = *(UINT16 *)(descriptor + i));
+ else if (size == 4) signed_value = (INT32)(value = *(UINT32 *)(descriptor + i));
+ else
+ {
+ ERR("Unexpected item value size %d.\n", size);
+ return -1;
+ }
+ i += size;
+
+ if (bType == TAG_TYPE_RESERVED && bTag == 0x0F && size == 2)
{
/* Long data items: Should be unused */
ERR("Long Data Item, should be unused\n");
@@ -360,19 +355,9 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
}
else
{
- int bSizeActual = 0;
- int itemVal = 0;
unsigned int j;
- for (j = 0; j < bSize; j++)
- {
- if (i + j < length)
- {
- itemVal += descriptor[i + j] << (8 * j);
- bSizeActual++;
- }
- }
- TRACE(" 0x%x[%i], type %i , tag %i, size %i, val %i\n",b0,i-1,bType, bTag, bSize, itemVal );
+ TRACE(" 0x%x[%i], type %i , tag %i, size %i, val %i\n",b0,i-size-1,bType, bTag, size, value );
if (bType == TAG_TYPE_MAIN)
{
@@ -392,7 +377,7 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
feature->type = HidP_Output;
else
feature->type = HidP_Feature;
- parse_io_feature(bSize, itemVal, bTag, feature_index, feature);
+ parse_io_feature(size, value, bTag, feature_index, feature);
if (j < usages_top)
caps->NotRange.Usage = usages[j];
feature->caps = *caps;
@@ -429,9 +414,9 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
list_init(&subcollection->collections);
new_caps(caps);
- parse_collection(bSize, itemVal, subcollection);
+ parse_collection(size, value, subcollection);
- if ((i = parse_descriptor(descriptor, i+1, length, feature_index, collection_index, subcollection, caps, stack)) < 0) return i;
+ if ((i = parse_descriptor(descriptor, i, length, feature_index, collection_index, subcollection, caps, stack)) < 0) return i;
continue;
}
case TAG_MAIN_END_COLLECTION:
@@ -446,34 +431,34 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
switch(bTag)
{
case TAG_GLOBAL_USAGE_PAGE:
- caps->UsagePage = getValue(bSize, itemVal, FALSE);
+ caps->UsagePage = value;
break;
case TAG_GLOBAL_LOGICAL_MINIMUM:
- caps->LogicalMin = getValue(bSize, itemVal, TRUE);
+ caps->LogicalMin = signed_value;
break;
case TAG_GLOBAL_LOGICAL_MAXIMUM:
- caps->LogicalMax = getValue(bSize, itemVal, TRUE);
+ caps->LogicalMax = signed_value;
break;
case TAG_GLOBAL_PHYSICAL_MINIMUM:
- caps->PhysicalMin = getValue(bSize, itemVal, TRUE);
+ caps->PhysicalMin = signed_value;
break;
case TAG_GLOBAL_PHYSICAL_MAXIMUM:
- caps->PhysicalMax = getValue(bSize, itemVal, TRUE);
+ caps->PhysicalMax = signed_value;
break;
case TAG_GLOBAL_UNIT_EXPONENT:
- caps->UnitsExp = getValue(bSize, itemVal, TRUE);
+ caps->UnitsExp = signed_value;
break;
case TAG_GLOBAL_UNIT:
- caps->Units = getValue(bSize, itemVal, TRUE);
+ caps->Units = signed_value;
break;
case TAG_GLOBAL_REPORT_SIZE:
- caps->BitSize = getValue(bSize, itemVal, FALSE);
+ caps->BitSize = value;
break;
case TAG_GLOBAL_REPORT_ID:
- caps->ReportID = getValue(bSize, itemVal, FALSE);
+ caps->ReportID = value;
break;
case TAG_GLOBAL_REPORT_COUNT:
- caps->ReportCount = getValue(bSize, itemVal, FALSE);
+ caps->ReportCount = value;
break;
case TAG_GLOBAL_PUSH:
{
@@ -521,44 +506,44 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
}
else
{
- usages[usages_top++] = getValue(bSize, itemVal, FALSE);
+ usages[usages_top++] = value;
caps->IsRange = FALSE;
}
break;
case TAG_LOCAL_USAGE_MINIMUM:
- caps->Range.UsageMin = getValue(bSize, itemVal, FALSE);
+ caps->Range.UsageMin = value;
caps->IsRange = TRUE;
break;
case TAG_LOCAL_USAGE_MAXIMUM:
- caps->Range.UsageMax = getValue(bSize, itemVal, FALSE);
+ caps->Range.UsageMax = value;
caps->IsRange = TRUE;
break;
case TAG_LOCAL_DESIGNATOR_INDEX:
- caps->NotRange.DesignatorIndex = getValue(bSize, itemVal, FALSE);
+ caps->NotRange.DesignatorIndex = value;
caps->IsDesignatorRange = FALSE;
break;
case TAG_LOCAL_DESIGNATOR_MINIMUM:
- caps->Range.DesignatorMin = getValue(bSize, itemVal, FALSE);
+ caps->Range.DesignatorMin = value;
caps->IsDesignatorRange = TRUE;
break;
case TAG_LOCAL_DESIGNATOR_MAXIMUM:
- caps->Range.DesignatorMax = getValue(bSize, itemVal, FALSE);
+ caps->Range.DesignatorMax = value;
caps->IsDesignatorRange = TRUE;
break;
case TAG_LOCAL_STRING_INDEX:
- caps->NotRange.StringIndex = getValue(bSize, itemVal, FALSE);
+ caps->NotRange.StringIndex = value;
caps->IsStringRange = FALSE;
break;
case TAG_LOCAL_STRING_MINIMUM:
- caps->Range.StringMin = getValue(bSize, itemVal, FALSE);
+ caps->Range.StringMin = value;
caps->IsStringRange = TRUE;
break;
case TAG_LOCAL_STRING_MAXIMUM:
- caps->Range.StringMax = getValue(bSize, itemVal, FALSE);
+ caps->Range.StringMax = value;
caps->IsStringRange = TRUE;
break;
case TAG_LOCAL_DELIMITER:
- FIXME("delimiter %d not implemented!\n", itemVal);
+ FIXME("delimiter %d not implemented!\n", value);
return -1;
default:
ERR("Unknown (bTag: 0x%x, bType: 0x%x)\n", bTag, bType);
@@ -570,8 +555,6 @@ static int parse_descriptor(BYTE *descriptor, unsigned int index, unsigned int l
ERR("Unknown (bTag: 0x%x, bType: 0x%x)\n", bTag, bType);
return -1;
}
-
- i += bSize;
}
}
return i;
--
2.31.0
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