?? otvcommn.c
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/***************************************************************************/
/* */
/* otvcommn.c */
/* */
/* OpenType common tables validation (body). */
/* */
/* Copyright 2004, 2005, 2006 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include "otvcommn.h"
/*************************************************************************/
/* */
/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
/* messages during execution. */
/* */
#undef FT_COMPONENT
#define FT_COMPONENT trace_otvcommon
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** COVERAGE TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
otv_Coverage_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt CoverageFormat;
OTV_NAME_ENTER( "Coverage" );
OTV_LIMIT_CHECK( 4 );
CoverageFormat = FT_NEXT_USHORT( p );
OTV_TRACE(( " (format %d)\n", CoverageFormat ));
switch ( CoverageFormat )
{
case 1: /* CoverageFormat1 */
{
FT_UInt GlyphCount;
GlyphCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));
OTV_LIMIT_CHECK( GlyphCount * 2 ); /* GlyphArray */
}
break;
case 2: /* CoverageFormat2 */
{
FT_UInt n, RangeCount;
FT_UInt Start, End, StartCoverageIndex, total = 0, last = 0;
RangeCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (RangeCount = %d)\n", RangeCount ));
OTV_LIMIT_CHECK( RangeCount * 6 );
/* RangeRecord */
for ( n = 0; n < RangeCount; n++ )
{
Start = FT_NEXT_USHORT( p );
End = FT_NEXT_USHORT( p );
StartCoverageIndex = FT_NEXT_USHORT( p );
if ( Start > End || StartCoverageIndex != total )
FT_INVALID_DATA;
if ( n > 0 && Start <= last )
FT_INVALID_DATA;
total += End - Start + 1;
last = End;
}
}
break;
default:
FT_INVALID_FORMAT;
}
/* no need to check glyph indices used as input to coverage tables */
/* since even invalid glyph indices return a meaningful result */
OTV_EXIT;
}
FT_LOCAL_DEF( FT_UInt )
otv_Coverage_get_first( FT_Bytes table )
{
FT_Bytes p = table;
p += 4; /* skip CoverageFormat and Glyph/RangeCount */
return FT_NEXT_USHORT( p );
}
FT_LOCAL_DEF( FT_UInt )
otv_Coverage_get_last( FT_Bytes table )
{
FT_Bytes p = table;
FT_UInt CoverageFormat = FT_NEXT_USHORT( p );
FT_UInt count = FT_NEXT_USHORT( p ); /* Glyph/RangeCount */
FT_UInt result = 0;
switch ( CoverageFormat )
{
case 1:
p += ( count - 1 ) * 2;
result = FT_NEXT_USHORT( p );
break;
case 2:
p += ( count - 1 ) * 6 + 2;
result = FT_NEXT_USHORT( p );
break;
default:
;
}
return result;
}
FT_LOCAL_DEF( FT_UInt )
otv_Coverage_get_count( FT_Bytes table )
{
FT_Bytes p = table;
FT_UInt CoverageFormat = FT_NEXT_USHORT( p );
FT_UInt count = FT_NEXT_USHORT( p ); /* Glyph/RangeCount */
FT_UInt result = 0;
switch ( CoverageFormat )
{
case 1:
return count;
case 2:
{
FT_UInt Start, End;
for ( ; count > 0; count-- )
{
Start = FT_NEXT_USHORT( p );
End = FT_NEXT_USHORT( p );
p += 2; /* skip StartCoverageIndex */
result += End - Start + 1;
}
}
break;
default:
;
}
return result;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** CLASS DEFINITION TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
otv_ClassDef_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt ClassFormat;
OTV_NAME_ENTER( "ClassDef" );
OTV_LIMIT_CHECK( 4 );
ClassFormat = FT_NEXT_USHORT( p );
OTV_TRACE(( " (format %d)\n", ClassFormat ));
switch ( ClassFormat )
{
case 1: /* ClassDefFormat1 */
{
FT_UInt GlyphCount;
p += 2; /* skip StartGlyph */
OTV_LIMIT_CHECK( 2 );
GlyphCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));
OTV_LIMIT_CHECK( GlyphCount * 2 ); /* ClassValueArray */
}
break;
case 2: /* ClassDefFormat2 */
{
FT_UInt n, ClassRangeCount;
FT_UInt Start, End, last = 0;
ClassRangeCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (ClassRangeCount = %d)\n", ClassRangeCount ));
OTV_LIMIT_CHECK( ClassRangeCount * 6 );
/* ClassRangeRecord */
for ( n = 0; n < ClassRangeCount; n++ )
{
Start = FT_NEXT_USHORT( p );
End = FT_NEXT_USHORT( p );
p += 2; /* skip Class */
if ( Start > End || ( n > 0 && Start <= last ) )
FT_INVALID_DATA;
last = End;
}
}
break;
default:
FT_INVALID_FORMAT;
}
/* no need to check glyph indices used as input to class definition */
/* tables since even invalid glyph indices return a meaningful result */
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** DEVICE TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
otv_Device_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt StartSize, EndSize, DeltaFormat, count;
OTV_NAME_ENTER( "Device" );
OTV_LIMIT_CHECK( 8 );
StartSize = FT_NEXT_USHORT( p );
EndSize = FT_NEXT_USHORT( p );
DeltaFormat = FT_NEXT_USHORT( p );
if ( DeltaFormat < 1 || DeltaFormat > 3 || EndSize < StartSize )
FT_INVALID_DATA;
count = EndSize - StartSize + 1;
OTV_LIMIT_CHECK( ( 1 << DeltaFormat ) * count / 8 ); /* DeltaValue */
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** LOOKUPS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* uses valid->type_count */
/* uses valid->type_funcs */
FT_LOCAL_DEF( void )
otv_Lookup_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt LookupType, SubTableCount;
OTV_Validate_Func validate;
OTV_NAME_ENTER( "Lookup" );
OTV_LIMIT_CHECK( 6 );
LookupType = FT_NEXT_USHORT( p );
p += 2; /* skip LookupFlag */
SubTableCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (type %d)\n", LookupType ));
if ( LookupType == 0 || LookupType >= valid->type_count )
FT_INVALID_DATA;
validate = valid->type_funcs[LookupType - 1];
OTV_TRACE(( " (SubTableCount = %d)\n", SubTableCount ));
OTV_LIMIT_CHECK( SubTableCount * 2 );
/* SubTable */
for ( ; SubTableCount > 0; SubTableCount-- )
validate( table + FT_NEXT_USHORT( p ), valid );
OTV_EXIT;
}
/* uses valid->lookup_count */
FT_LOCAL_DEF( void )
otv_LookupList_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt LookupCount;
OTV_NAME_ENTER( "LookupList" );
OTV_LIMIT_CHECK( 2 );
LookupCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (LookupCount = %d)\n", LookupCount ));
OTV_LIMIT_CHECK( LookupCount * 2 );
valid->lookup_count = LookupCount;
/* Lookup */
for ( ; LookupCount > 0; LookupCount-- )
otv_Lookup_validate( table + FT_NEXT_USHORT( p ), valid );
OTV_EXIT;
}
static FT_UInt
otv_LookupList_get_count( FT_Bytes table )
{
return FT_NEXT_USHORT( table );
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FEATURES *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* uses valid->lookup_count */
FT_LOCAL_DEF( void )
otv_Feature_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt LookupCount;
OTV_NAME_ENTER( "Feature" );
OTV_LIMIT_CHECK( 4 );
p += 2; /* skip FeatureParams (unused) */
LookupCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (LookupCount = %d)\n", LookupCount ));
OTV_LIMIT_CHECK( LookupCount * 2 );
/* LookupListIndex */
for ( ; LookupCount > 0; LookupCount-- )
if ( FT_NEXT_USHORT( p ) >= valid->lookup_count )
FT_INVALID_DATA;
OTV_EXIT;
}
static FT_UInt
otv_Feature_get_count( FT_Bytes table )
{
return FT_NEXT_USHORT( table );
}
/* sets valid->lookup_count */
FT_LOCAL_DEF( void )
otv_FeatureList_validate( FT_Bytes table,
FT_Bytes lookups,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt FeatureCount;
OTV_NAME_ENTER( "FeatureList" );
OTV_LIMIT_CHECK( 2 );
FeatureCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (FeatureCount = %d)\n", FeatureCount ));
OTV_LIMIT_CHECK( FeatureCount * 2 );
valid->lookup_count = otv_LookupList_get_count( lookups );
/* FeatureRecord */
for ( ; FeatureCount > 0; FeatureCount-- )
{
p += 4; /* skip FeatureTag */
/* Feature */
otv_Feature_validate( table + FT_NEXT_USHORT( p ), valid );
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** LANGUAGE SYSTEM *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* uses valid->extra1 (number of features) */
FT_LOCAL_DEF( void )
otv_LangSys_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt ReqFeatureIndex;
FT_UInt FeatureCount;
OTV_NAME_ENTER( "LangSys" );
OTV_LIMIT_CHECK( 6 );
p += 2; /* skip LookupOrder (unused) */
ReqFeatureIndex = FT_NEXT_USHORT( p );
FeatureCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (ReqFeatureIndex = %d)\n", ReqFeatureIndex ));
OTV_TRACE(( " (FeatureCount = %d)\n", FeatureCount ));
if ( ReqFeatureIndex != 0xFFFFU && ReqFeatureIndex >= valid->extra1 )
FT_INVALID_DATA;
OTV_LIMIT_CHECK( FeatureCount * 2 );
/* FeatureIndex */
for ( ; FeatureCount > 0; FeatureCount-- )
if ( FT_NEXT_USHORT( p ) >= valid->extra1 )
FT_INVALID_DATA;
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** SCRIPTS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
otv_Script_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_UInt DefaultLangSys, LangSysCount;
FT_Bytes p = table;
OTV_NAME_ENTER( "Script" );
OTV_LIMIT_CHECK( 4 );
DefaultLangSys = FT_NEXT_USHORT( p );
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