ref: a438621451bf126b4819d263c4df8c19db9fd9e2
dir: /src/gxvalid/gxvkern.c/
/***************************************************************************/
/* */
/* gxvkern.c */
/* */
/* TrueTypeGX/AAT kern table validation (body). */
/* */
/* Copyright 2004, 2005 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 was support of Information-technology Promotion */
/* Agency(IPA), Japan. */
/***************************************************************************/
#include "gxvalid.h"
#include "gxvcommn.h"
#include FT_SFNT_NAMES_H
#include FT_SERVICE_GX_VALIDATE_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_gxvkern
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** Data and Types *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
typedef enum GXV_kern_Version_
{
KERN_VERSION_CLASSIC = 0x0000,
KERN_VERSION_NEW = 0x0001
} GXV_kern_Version;
typedef enum GXV_kern_Dialect_
{
KERN_DIALECT_MS = FT_VALIDATE_MS,
KERN_DIALECT_APPLE = FT_VALIDATE_APPLE,
KERN_DIALECT_ANY = FT_VALIDATE_CKERN
} GXV_kern_Dialect;
typedef struct GXV_kern_DataRec_
{
GXV_kern_Version version;
void *subtable_data;
GXV_kern_Dialect dialect_request;
} GXV_kern_DataRec, *GXV_kern_Data;
#define GXV_KERN_DATA( field ) GXV_TABLE_DATA( kern, field )
#define KERN_IS_CLASSIC( valid ) ( KERN_VERSION_CLASSIC == GXV_KERN_DATA( version ) )
#define KERN_IS_NEW( valid ) ( KERN_VERSION_NEW == GXV_KERN_DATA( version ) )
#define KERN_DIALECT( valid ) GXV_KERN_DATA( dialect_request )
#define KERN_ALLOWS_MS( valid ) ( KERN_DIALECT( valid ) & KERN_DIALECT_MS )
#define KERN_ALLOWS_APPLE( valid ) ( KERN_DIALECT( valid ) & KERN_DIALECT_APPLE )
#define GXV_KERN_HEADER_SIZE ( KERN_IS_NEW( valid ) ? 8 : 4 )
#define GXV_KERN_SUBTABLE_HEADER_SIZE ( KERN_IS_NEW( valid ) ? 8 : 6 )
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** SUBTABLE VALIDATORS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* ============================= format 0 ============================== */
static void
gxv_kern_subtable_fmt0_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
FT_UShort nPairs;
FT_UShort unitSize;
FT_UShort i;
GXV_NAME_ENTER("kern subtable format0");
unitSize = ( 2 + 2 + 2 );
nPairs = 0;
/* nPairs, searchRange, entrySelector, rangeShift */
GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
gxv_BinSrchHeader_validate( p, limit, &unitSize, &nPairs, valid );
p += 2 + 2 + 2 + 2;
for ( i = 0; i < nPairs; i++ )
{
FT_UShort gid_left;
FT_UShort gid_right;
FT_Short kernValue;
/* TODO: should be checked pairs are unique. */
/* left */
gid_left = FT_NEXT_USHORT( p );
gxv_glyphid_validate( gid_left, valid );
/* right */
gid_right = FT_NEXT_USHORT( p );
gxv_glyphid_validate( gid_right, valid );
/* skip the kern value */
kernValue = FT_NEXT_SHORT( p );
}
GXV_EXIT;
}
/* ============================= format 1 ============================== */
typedef struct GXV_kern_fmt1_StateOptRec_
{
FT_UShort valueTable;
FT_UShort valueTable_length;
} GXV_kern_fmt1_StateOptRec, *GXV_kern_fmt1_StateOptRecData;
static void
gxv_kern_subtable_fmt1_valueTable_load( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_Bytes p = table;
GXV_kern_fmt1_StateOptRecData optdata = valid->statetable.optdata;
GXV_LIMIT_CHECK( 2 );
optdata->valueTable = FT_NEXT_USHORT( p );
}
/*
* passed tables_size covers whole StateTable, including kern fmt1 header
*/
static void
gxv_kern_subtable_fmt1_subtable_setup( FT_UShort table_size,
FT_UShort classTable,
FT_UShort stateArray,
FT_UShort entryTable,
FT_UShort* classTable_length_p,
FT_UShort* stateArray_length_p,
FT_UShort* entryTable_length_p,
GXV_Validator valid )
{
FT_UShort o[4];
FT_UShort *l[4];
FT_UShort buff[5];
GXV_kern_fmt1_StateOptRecData optdata = valid->statetable.optdata;
o[0] = classTable;
o[1] = stateArray;
o[2] = entryTable;
o[3] = optdata->valueTable;
l[0] = classTable_length_p;
l[1] = stateArray_length_p;
l[2] = entryTable_length_p;
l[3] = &(optdata->valueTable_length);
gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, valid );
}
/*
* passed table & limit are of whole of StateTable, not included subtables.
*/
static void
gxv_kern_subtable_fmt1_entry_validate( FT_Byte state,
FT_UShort flags,
GXV_StateTable_GlyphOffsetDesc glyphOffset,
FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_UShort push;
FT_UShort dontAdvance;
FT_UShort valueOffset;
FT_UShort kernAction;
FT_UShort kernValue;
push = flags / 0x8000;
dontAdvance = ( flags & 0x4000 ) / 0x4000;
valueOffset = flags & 0x3FFF;
{
GXV_kern_fmt1_StateOptRecData vt_rec = valid->statetable.optdata;
FT_Bytes p;
if ( valueOffset < vt_rec->valueTable )
FT_INVALID_OFFSET;
p = table + valueOffset;
limit = table + vt_rec->valueTable + vt_rec->valueTable_length;
GXV_LIMIT_CHECK( 2 + 2 );
kernAction = FT_NEXT_USHORT( p );
kernValue = FT_NEXT_USHORT( p );
}
}
static void
gxv_kern_subtable_fmt1_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_Bytes p = table;
GXV_kern_fmt1_StateOptRec vt_rec;
GXV_NAME_ENTER("kern subtable format1");
valid->statetable.optdata = &vt_rec;
valid->statetable.optdata_load_func = gxv_kern_subtable_fmt1_valueTable_load;
valid->statetable.subtable_setup_func = gxv_kern_subtable_fmt1_subtable_setup;
valid->statetable.entry_glyphoffset_fmt = GXV_GLYPHOFFSET_NONE;
valid->statetable.entry_validate_func = gxv_kern_subtable_fmt1_entry_validate;
gxv_StateTable_validate( p, limit, valid );
GXV_EXIT;
}
/* ================ Data for Class-Based Subtables 2, 3 ================ */
typedef enum GXV_kern_ClassSpec_
{
GXV_KERN_CLS_L = 0,
GXV_KERN_CLS_R
} GXV_kern_ClassSpec;
/* ============================= format 2 ============================== */
/* ---------------------- format 2 specific data ----------------------- */
typedef struct GXV_kern_subtable_fmt2_DataRec_
{
FT_UShort rowWidth;
FT_UShort array;
FT_UShort offset_min[2];
FT_UShort offset_max[2];
FT_String* class_tag[2];
GXV_odtect_Range odtect;
} GXV_kern_subtable_fmt2_DataRec, *GXV_kern_subtable_fmt2_Data;
#define GXV_KERN_FMT2_DATA( field ) \
(((GXV_kern_subtable_fmt2_DataRec *)(GXV_KERN_DATA( subtable_data )))-> field )
/* -------------------------- utility functions ----------------------- */
static void
gxv_kern_subtable_fmt2_clstbl_validate( FT_Bytes table,
FT_Bytes limit,
GXV_kern_ClassSpec spec,
GXV_Validator valid )
{
FT_String* tag = GXV_KERN_FMT2_DATA( class_tag[spec] );
GXV_odtect_Range odtect = GXV_KERN_FMT2_DATA( odtect );
FT_Bytes p = table;
FT_UShort firstGlyph;
FT_UShort nGlyphs;
GXV_NAME_ENTER(( "kern format 2 classTable" ));
GXV_LIMIT_CHECK( 2 + 2 );
firstGlyph = FT_NEXT_USHORT( p );
nGlyphs = FT_NEXT_USHORT( p );
GXV_TRACE(( " %s firstGlyph=%d, nGlyphs=%d\n", tag, firstGlyph, nGlyphs ));
gxv_glyphid_validate( firstGlyph, valid );
gxv_glyphid_validate( firstGlyph + nGlyphs - 1, valid );
gxv_array_getlimits_ushort( p, p + ( 2 * nGlyphs ),
&( GXV_KERN_FMT2_DATA( offset_min[spec] ) ),
&( GXV_KERN_FMT2_DATA( offset_max[spec] ) ),
valid );
gxv_odtect_add_range( table, ( 2 * nGlyphs ), tag, odtect );
GXV_EXIT;
}
static void
gxv_kern_subtable_fmt2_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
GXV_ODTECT( 3, odtect );
GXV_kern_subtable_fmt2_DataRec fmt2_rec =
{ 0, 0, { 0, 0 }, { 0, 0 }, { "leftClass", "rightClass" }, NULL };
FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
FT_UShort leftOffsetTable;
FT_UShort rightOffsetTable;
GXV_NAME_ENTER("kern subtable format2");
GXV_ODTECT_INIT( odtect );
fmt2_rec.odtect = odtect;
GXV_KERN_DATA( subtable_data ) = &fmt2_rec;
GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
GXV_KERN_FMT2_DATA( rowWidth ) = FT_NEXT_USHORT( p );
leftOffsetTable = FT_NEXT_USHORT( p );
rightOffsetTable = FT_NEXT_USHORT( p );
GXV_KERN_FMT2_DATA( array ) = FT_NEXT_USHORT( p );
GXV_TRACE(( "rowWidth = %d\n", GXV_KERN_FMT2_DATA( rowWidth ) ));
GXV_LIMIT_CHECK( leftOffsetTable );
GXV_LIMIT_CHECK( rightOffsetTable );
GXV_LIMIT_CHECK( GXV_KERN_FMT2_DATA( array ) );
gxv_kern_subtable_fmt2_clstbl_validate( table + leftOffsetTable, limit,
GXV_KERN_CLS_L, valid );
gxv_kern_subtable_fmt2_clstbl_validate( table + rightOffsetTable, limit,
GXV_KERN_CLS_R, valid );
if ( GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_L] )
+ GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_R] )
< GXV_KERN_FMT2_DATA( array ) )
FT_INVALID_OFFSET;
gxv_odtect_add_range( table + GXV_KERN_FMT2_DATA( array ),
GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_L] )
+ GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_R] )
- GXV_KERN_FMT2_DATA( array ),
"array", odtect );
gxv_odtect_validate( odtect, valid );
GXV_EXIT;
}
/* ============================= format 3 ============================== */
static void
gxv_kern_subtable_fmt3_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
FT_UShort glyphCount;
FT_Byte kernValueCount;
FT_Byte leftClassCount;
FT_Byte rightClassCount;
FT_Byte flags;
GXV_NAME_ENTER("kern subtable format3");
GXV_LIMIT_CHECK( 2 + 1 + 1 + 1 + 1 );
glyphCount = FT_NEXT_USHORT( p );
kernValueCount = FT_NEXT_BYTE( p );
leftClassCount = FT_NEXT_BYTE( p );
rightClassCount = FT_NEXT_BYTE( p );
flags = FT_NEXT_BYTE( p );
if ( valid->face->num_glyphs != glyphCount )
{
GXV_TRACE(( "maxGID=%d, but glyphCount=%d\n", valid->face->num_glyphs, glyphCount ));
if ( valid->root->level >= FT_VALIDATE_PARANOID )
FT_INVALID_GLYPH_ID;
}
/*
* Just skip kernValue[kernValueCount]
*/
GXV_LIMIT_CHECK( 2 * kernValueCount );
p += ( 2 * kernValueCount );
/*
* check leftClass[gid] < leftClassCount
*/
{
FT_Byte min, max;
GXV_LIMIT_CHECK( glyphCount );
gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, valid );
p += valid->subtable_length;
if ( leftClassCount < max )
FT_INVALID_DATA;
}
/*
* check rightClass[gid] < rightClassCount
*/
{
FT_Byte min, max;
GXV_LIMIT_CHECK( glyphCount );
gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, valid );
p += valid->subtable_length;
if ( rightClassCount < max )
FT_INVALID_DATA;
}
/*
* check kernIndex[i, j] < kernValueCount
*/
{
FT_UShort i, j;
for ( i = 0; i < leftClassCount; i ++ )
{
for ( j = 0; j < rightClassCount; j ++ )
{
GXV_LIMIT_CHECK( 1 );
if ( kernValueCount < FT_NEXT_BYTE( p ) )
FT_INVALID_OFFSET;
}
}
}
valid->subtable_length = ( p - table );
GXV_EXIT;
}
static FT_Bool
gxv_kern_coverage_new_apple_validate( FT_UShort coverage,
FT_UShort* format,
GXV_Validator valid )
{
/* new Apple-dialect */
FT_Bool kernVertical;
FT_Bool kernCrossStream;
FT_Bool kernVariation;
/* reserved bits = 0 */
if ( coverage & 0x1FFC )
return FALSE;
kernVertical = ( coverage >> 15 ) & 1;
kernCrossStream = ( coverage >> 14 ) & 1;
kernVariation = ( coverage >> 13 ) & 1;
*format = coverage & 0x0003;
GXV_TRACE(( "new Apple-dialect: "
"horizontal=%d, cross-stream=%d, variation=%d, format=%d\n",
!kernVertical, kernCrossStream, kernVariation, *format ));
GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));
return TRUE;
}
static FT_Bool
gxv_kern_coverage_classic_apple_validate( FT_UShort coverage,
FT_UShort* format,
GXV_Validator valid )
{
/* classic Apple-dialect */
FT_Bool horizontal;
FT_Bool cross_stream;
/* expected flags but don't check if MS-dialect is impossible */
if ( !( coverage & 0xFD00 ) && KERN_ALLOWS_MS( valid ) )
return FALSE;
/* reserved bits = 0 */
if ( coverage & 0x02FC )
return FALSE;
horizontal = ( coverage >> 15 ) & 1;
cross_stream = ( coverage >> 13 ) & 1;
*format = coverage & 0x0003;
GXV_TRACE(( "classic Apple-dialect: "
"horizontal=%d, cross-stream=%d, format=%d\n",
horizontal, cross_stream, *format ));
/* format1 requires GX State Machine, too new for classic */
if ( *format == 1 )
return FALSE;
GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));
return TRUE;
}
static FT_Bool
gxv_kern_coverage_classic_microsoft_validate( FT_UShort coverage,
FT_UShort* format,
GXV_Validator valid )
{
/* classic Microsoft-dialect */
FT_Bool horizontal;
FT_Bool minimum;
FT_Bool cross_stream;
FT_Bool override;
/* reserved bits = 0 */
if ( coverage & 0xFDF0 )
return FALSE;
horizontal = coverage & 1;
minimum = ( coverage >> 1 ) & 1;
cross_stream = ( coverage >> 2 ) & 1;
override = ( coverage >> 3 ) & 1;
*format = ( coverage >> 8 ) & 0x0003;
GXV_TRACE(( "classic Microsoft-dialect: "
"horizontal=%d, minimum=%d, cross-stream=%d, override=%d, format=%d\n",
horizontal, minimum, cross_stream, override, *format ));
if ( *format == 2 )
GXV_TRACE(( "kerning values in Microsoft format 2 subtable are ignored\n" ));
return TRUE;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MAIN *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static GXV_kern_Dialect
gxv_kern_coverage_validate ( FT_UShort coverage,
FT_UShort* format,
GXV_Validator valid )
{
FT_Int result = 0;
GXV_NAME_ENTER(( "validate coverage" ));
GXV_TRACE(( "interprete coverage 0x%04x by Apple style\n", coverage ));
if ( KERN_IS_NEW( valid ) )
{
if ( gxv_kern_coverage_new_apple_validate( coverage,
format,
valid ) )
{
result = KERN_DIALECT_APPLE;
goto Exit;
}
}
if ( KERN_IS_CLASSIC( valid ) && KERN_ALLOWS_APPLE( valid ) )
{
if ( gxv_kern_coverage_classic_apple_validate( coverage,
format,
valid ) )
{
result = KERN_DIALECT_APPLE;
goto Exit;
}
}
if ( KERN_IS_CLASSIC( valid ) && KERN_ALLOWS_MS( valid ) )
{
if ( gxv_kern_coverage_classic_microsoft_validate( coverage,
format,
valid ) )
{
result = KERN_DIALECT_MS;
goto Exit;
}
}
GXV_TRACE(( "cannot interprete coverage, broken kern subtable\n" ));
Exit:
GXV_EXIT;
return result;
}
static void
gxv_kern_subtable_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator valid )
{
FT_Bytes p = table;
FT_UShort version = 0; /* MS only: subtable version, unused */
FT_ULong length; /* MS: 16bit, Apple: 32bit*/
FT_UShort coverage;
FT_UShort tupleIndex = 0; /* Apple only */
FT_UShort u16[2];
FT_UShort format = 255; /* subtable format */
GXV_NAME_ENTER("kern subtable");
GXV_LIMIT_CHECK( 2 + 2 + 2 );
u16[0] = FT_NEXT_USHORT( p ); /* Apple: length_hi MS: version */
u16[1] = FT_NEXT_USHORT( p ); /* Apple: length_lo MS: length */
coverage = FT_NEXT_USHORT( p );
switch ( gxv_kern_coverage_validate( coverage, &format, valid ) )
{
case KERN_DIALECT_MS:
version = u16[0];
length = u16[1];
tupleIndex = 0;
GXV_TRACE(( "Subtable version = %d\n", version ));
GXV_TRACE(( "Subtable length = %d\n", length ));
break;
case KERN_DIALECT_APPLE:
version = 0;
length = ( u16[0] << 16 ) + u16[1];
tupleIndex = 0;
GXV_TRACE(( "Subtable length = %d\n", length ));
if ( KERN_IS_NEW( valid ))
{
GXV_LIMIT_CHECK( 2 );
tupleIndex = FT_NEXT_USHORT( p );
GXV_TRACE(( "Subtable tupleIndex = %d\n", tupleIndex ));
}
break;
default:
length = u16[1];
GXV_TRACE(( "cannot detect subtable dialect, "
"just skip %d byte\n", length ));
goto Exit;
}
/* fmt1, 2, 3 requires the position of the start of this subtable */
if ( format == 0 )
gxv_kern_subtable_fmt0_validate( table, table + length, valid );
else if ( format == 1 )
gxv_kern_subtable_fmt1_validate( table, table + length, valid );
else if ( format == 2 )
gxv_kern_subtable_fmt2_validate( table, table + length, valid );
else if ( format == 3 )
gxv_kern_subtable_fmt3_validate( table, table + length, valid );
else
FT_INVALID_DATA;
Exit:
valid->subtable_length = length;
GXV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** kern TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
gxv_kern_validate_generic( FT_Bytes table,
FT_Face face,
FT_Bool classic_only,
GXV_kern_Dialect dialect_request,
FT_Validator ftvalid )
{
GXV_ValidatorRec validrec;
GXV_Validator valid = &validrec;
GXV_kern_DataRec kernrec;
GXV_kern_Data kern = &kernrec;
FT_Bytes p = table;
FT_Bytes limit = 0;
FT_ULong nTables = 0;
FT_UInt i;
valid->root = ftvalid;
valid->table_data = kern;
valid->face = face;
FT_TRACE3(( "validation kern table\n" ));
GXV_INIT;
KERN_DIALECT( valid ) = dialect_request;
GXV_LIMIT_CHECK( 2 );
GXV_KERN_DATA( version ) = FT_NEXT_USHORT( p );
GXV_TRACE(( "version 0x%04x (higher 16bit)\n", GXV_KERN_DATA( version ) ));
if ( 0x0001 < GXV_KERN_DATA( version ) )
FT_INVALID_FORMAT;
else if ( KERN_IS_CLASSIC( valid ) )
{
GXV_LIMIT_CHECK( 2 );
nTables = FT_NEXT_USHORT( p );
}
else if ( KERN_IS_NEW( valid ) )
{
if ( classic_only )
FT_INVALID_FORMAT;
if ( 0x0000 != FT_NEXT_USHORT( p ) )
FT_INVALID_FORMAT;
GXV_LIMIT_CHECK( 4 );
nTables = FT_NEXT_ULONG( p );
}
for ( i = 0; i < nTables; i++ )
{
GXV_TRACE(( "validate subtable %d/%d\n", i, nTables ));
/* p should be 32bit-aligned? */
gxv_kern_subtable_validate( p, 0, valid );
p += valid->subtable_length;
}
FT_TRACE4(( "\n" ));
}
FT_LOCAL_DEF( void )
gxv_kern_validate( FT_Bytes table,
FT_Face face,
FT_Validator ftvalid )
{
gxv_kern_validate_generic( table, face, 0, KERN_DIALECT_ANY, ftvalid );
}
FT_LOCAL_DEF( void )
gxv_kern_validate_classic( FT_Bytes table,
FT_Face face,
FT_Int dialect_flags,
FT_Validator ftvalid )
{
GXV_kern_Dialect dialect_request;
dialect_request = dialect_flags;
gxv_kern_validate_generic( table, face, 1, dialect_request, ftvalid );
}
/* END */