From: "Rémi Bernon" Subject: [PATCH 6/7] hidclass.sys: Simplify signed / unsigned item value parsing. Message-Id: <20210608072641.1358397-6-rbernon@codeweavers.com> Date: Tue, 8 Jun 2021 09:26:40 +0200 In-Reply-To: <20210608072641.1358397-1-rbernon@codeweavers.com> References: <20210608072641.1358397-1-rbernon@codeweavers.com> Signed-off-by: Rémi Bernon --- 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 736317ca7bf..4a0ee007841 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