ref: 96508b74b421cb8f6cb2d2bbb4a1792c6637e221
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 is supported by the 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_UNKNOWN = 0, 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 = (GXV_kern_fmt1_StateOptRecData)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 = (GXV_kern_fmt1_StateOptRecData)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 StateTable, not including 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; FT_UNUSED( state ); FT_UNUSED( glyphOffset ); push = (FT_UShort)( ( flags >> 15 ) & 1 ); dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 ); valueOffset = (FT_UShort)( flags & 0x3FFF ); { GXV_kern_fmt1_StateOptRecData vt_rec = (GXV_kern_fmt1_StateOptRecData)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]; const 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 ) { const 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( (FT_UShort)( 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; FT_UNUSED( valid ); /* reserved bits = 0 */ if ( coverage & 0x1FFC ) return 0; kernVertical = FT_BOOL( ( coverage >> 15 ) & 1 ); kernCrossStream = FT_BOOL( ( coverage >> 14 ) & 1 ); kernVariation = FT_BOOL( ( coverage >> 13 ) & 1 ); *format = (FT_UShort)( 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 1; } 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; /* check expected flags, but don't check if MS-dialect is impossible */ if ( !( coverage & 0xFD00 ) && KERN_ALLOWS_MS( valid ) ) return 0; /* reserved bits = 0 */ if ( coverage & 0x02FC ) return 0; horizontal = FT_BOOL( ( coverage >> 15 ) & 1 ); cross_stream = FT_BOOL( ( coverage >> 13 ) & 1 ); *format = (FT_UShort)( coverage & 0x0003 ); GXV_TRACE(( "classic Apple-dialect: " "horizontal=%d, cross-stream=%d, format=%d\n", horizontal, cross_stream, *format )); /* format 1 requires GX State Machine, too new for classic */ if ( *format == 1 ) return 0; GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" )); return 1; } 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; FT_UNUSED( valid ); /* reserved bits = 0 */ if ( coverage & 0xFDF0 ) return 0; horizontal = FT_BOOL( coverage & 1 ); minimum = FT_BOOL( ( coverage >> 1 ) & 1 ); cross_stream = FT_BOOL( ( coverage >> 2 ) & 1 ); override = FT_BOOL( ( coverage >> 3 ) & 1 ); *format = (FT_UShort)( ( 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 1; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** MAIN *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static GXV_kern_Dialect gxv_kern_coverage_validate( FT_UShort coverage, FT_UShort* format, GXV_Validator valid ) { GXV_kern_Dialect result = KERN_DIALECT_UNKNOWN; GXV_NAME_ENTER( "validating 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; } /* formats 1, 2, 3 require 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(( "validating `kern' table\n" )); GXV_INIT; KERN_DIALECT( valid ) = dialect_request; GXV_LIMIT_CHECK( 2 ); GXV_KERN_DATA( version ) = (GXV_kern_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(( "validating 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 = (GXV_kern_Dialect)dialect_flags; gxv_kern_validate_generic( table, face, 1, dialect_request, ftvalid ); } /* END */