/****************************************************************************
*
* gxvprop.c
*
* TrueTypeGX/AAT prop table validation (body).
*
* Copyright (C) 2004-2021 by
* suzuki toshiya, Masatake YAMATO, Red Hat K.K.,
* 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.
*
*/
/****************************************************************************
*
* gxvalid is derived from both gxlayout module and otvalid module.
* Development of gxlayout is supported by the Information-technology
* Promotion Agency(IPA), Japan.
*
*/
#include "gxvalid.h"
#include "gxvcommn.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 gxvprop
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** Data and Types *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#define GXV_PROP_HEADER_SIZE ( 4 + 2 + 2 )
#define GXV_PROP_SIZE_MIN GXV_PROP_HEADER_SIZE
typedef struct GXV_prop_DataRec_
{
FT_Fixed version;
} GXV_prop_DataRec, *GXV_prop_Data;
#define GXV_PROP_DATA( field ) GXV_TABLE_DATA( prop, field )
#define GXV_PROP_FLOATER 0x8000U
#define GXV_PROP_USE_COMPLEMENTARY_BRACKET 0x1000U
#define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00U
#define GXV_PROP_ATTACHING_TO_RIGHT 0x0080U
#define GXV_PROP_RESERVED 0x0060U
#define GXV_PROP_DIRECTIONALITY_CLASS 0x001FU
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** UTILITY FUNCTIONS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
gxv_prop_zero_advance_validate( FT_UShort gid,
GXV_Validator gxvalid )
{
FT_Face face;
FT_Error error;
FT_GlyphSlot glyph;
GXV_NAME_ENTER( "zero advance" );
face = gxvalid->face;
error = FT_Load_Glyph( face,
gid,
FT_LOAD_IGNORE_TRANSFORM );
if ( error )
FT_INVALID_GLYPH_ID;
glyph = face->glyph;
if ( glyph->advance.x != (FT_Pos)0 ||
glyph->advance.y != (FT_Pos)0 )
{
GXV_TRACE(( " found non-zero advance in zero-advance glyph\n" ));
FT_INVALID_DATA;
}
GXV_EXIT;
}
/* Pass 0 as GLYPH to check the default property */
static void
gxv_prop_property_validate( FT_UShort property,
FT_UShort glyph,
GXV_Validator gxvalid )
{
if ( glyph != 0 && ( property & GXV_PROP_FLOATER ) )
gxv_prop_zero_advance_validate( glyph, gxvalid );
if ( property & GXV_PROP_USE_COMPLEMENTARY_BRACKET )
{
FT_UShort offset;
char complement;
offset = (FT_UShort)( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET );
if ( offset == 0 )
{
GXV_TRACE(( " found zero offset to property\n" ));
FT_INVALID_OFFSET;
}
complement = (char)( offset >> 8 );
if ( complement & 0x08 )
{
/* Top bit is set: negative */
/* Calculate the absolute offset */
complement = (char)( ( complement & 0x07 ) + 1 );
/* The gid for complement must be greater than 0 */
if ( glyph <= complement )
{
GXV_TRACE(( " found non-positive glyph complement\n" ));
FT_INVALID_DATA;
}
}
else
{
/* The gid for complement must be the face. */
gxv_glyphid_validate( (FT_UShort)( glyph + complement ), gxvalid );
}
}
else
{
if ( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET )
GXV_TRACE(( "glyph %d cannot have complementary bracketing\n",
glyph ));
}
/* this is introduced in version 2.0 */
if ( property & GXV_PROP_ATTACHING_TO_RIGHT )
{
if ( GXV_PROP_DATA( version ) == 0x00010000UL )
{
GXV_TRACE(( " found older version (1.0) in new version table\n" ));
FT_INVALID_DATA;
}
}
if ( property & GXV_PROP_RESERVED )
{
GXV_TRACE(( " found non-zero bits in reserved bits\n" ));
FT_INVALID_DATA;
}
if ( ( property & GXV_PROP_DIRECTIONALITY_CLASS ) > 11 )
{
/* TODO: Too restricted. Use the validation level. */
if ( GXV_PROP_DATA( version ) == 0x00010000UL ||
GXV_PROP_DATA( version ) == 0x00020000UL )
{
GXV_TRACE(( " found too old version in directionality class\n" ));
FT_INVALID_DATA;
}
}
}
static void
gxv_prop_LookupValue_validate( FT_UShort glyph,
GXV_LookupValueCPtr value_p,
GXV_Validator gxvalid )
{
gxv_prop_property_validate( value_p->u, glyph, gxvalid );
}
/*
+===============+ --------+
| lookup header | |
+===============+ |
| BinSrchHeader | |
+===============+ |
| lastGlyph[0] | |
+---------------+ |
| firstGlyph[0] | | head of lookup table
+---------------+ | +
| offset[0] | -> | offset [byte]
+===============+ | +
| lastGlyph[1] | | (glyphID - firstGlyph) * 2 [byte]
+---------------+ |
| firstGlyph[1] | |
+---------------+ |
| offset[1] | |
+===============+ |
|
... |
|
16bit value array |
+===============+ |
| value | <-------+
...
*/
static GXV_LookupValueDesc
gxv_prop_LookupFmt4_transit( FT_UShort relative_gindex,
GXV_LookupValueCPtr base_value_p,
FT_Bytes lookuptbl_limit,
GXV_Validator gxvalid )
{
FT_Bytes p;
FT_Bytes limit;
FT_UShort offset;
GXV_LookupValueDesc value;
/* XXX: check range? */
offset = (FT_UShort)( base_value_p->u +
relative_gindex * sizeof ( FT_UShort ) );
p = gxvalid->lookuptbl_head + offset;
limit = lookuptbl_limit;
GXV_LIMIT_CHECK ( 2 );
value.u = FT_NEXT_USHORT( p );
return value;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** prop TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
gxv_prop_validate( FT_Bytes table,
FT_Face face,
FT_Validator ftvalid )
{
FT_Bytes p = table;
FT_Bytes limit = 0;
GXV_ValidatorRec gxvalidrec;
GXV_Validator gxvalid = &gxvalidrec;
GXV_prop_DataRec proprec;
GXV_prop_Data prop = &proprec;
FT_Fixed version;
FT_UShort format;
FT_UShort defaultProp;
gxvalid->root = ftvalid;
gxvalid->table_data = prop;
gxvalid->face = face;
FT_TRACE3(( "validating `prop' table\n" ));
GXV_INIT;
GXV_LIMIT_CHECK( 4 + 2 + 2 );
version = FT_NEXT_LONG( p );
format = FT_NEXT_USHORT( p );
defaultProp = FT_NEXT_USHORT( p );
GXV_TRACE(( " version 0x%08x\n", version ));
GXV_TRACE(( " format 0x%04x\n", format ));
GXV_TRACE(( " defaultProp 0x%04x\n", defaultProp ));
/* only versions 1.0, 2.0, 3.0 are defined (1996) */
if ( version != 0x00010000UL &&
version != 0x00020000UL &&
version != 0x00030000UL )
{
GXV_TRACE(( " found unknown version\n" ));
FT_INVALID_FORMAT;
}
/* only formats 0x0000, 0x0001 are defined (1996) */
if ( format > 1 )
{
GXV_TRACE(( " found unknown format\n" ));
FT_INVALID_FORMAT;
}
gxv_prop_property_validate( defaultProp, 0, gxvalid );
if ( format == 0 )
{
FT_TRACE3(( "(format 0, no per-glyph properties, "
"remaining %d bytes are skipped)", limit - p ));
goto Exit;
}
/* format == 1 */
GXV_PROP_DATA( version ) = version;
gxvalid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED;
gxvalid->lookupval_func = gxv_prop_LookupValue_validate;
gxvalid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit;
gxv_LookupTable_validate( p, limit, gxvalid );
Exit:
FT_TRACE4(( "\n" ));
}
/* END */
