ref: c3e9f026058981ee7ef6bf0b15601e11e994b1d9
dir: /src/otvalid/otvgpos.c/
/***************************************************************************/ /* */ /* otvgpos.c */ /* */ /* OpenType GPOS table validation (body). */ /* */ /* Copyright 2002, 2004, 2005, 2006, 2007, 2008 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 "otvalid.h" #include "otvcommn.h" #include "otvgpos.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_otvgpos static void otv_Anchor_validate( FT_Bytes table, OTV_Validator valid ); static void otv_MarkArray_validate( FT_Bytes table, OTV_Validator valid ); /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** UTILITY FUNCTIONS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ #define BaseArrayFunc otv_x_sxy #define LigatureAttachFunc otv_x_sxy #define Mark2ArrayFunc otv_x_sxy /* uses valid->extra1 (counter) */ /* uses valid->extra2 (boolean to handle NULL anchor field) */ static void otv_x_sxy( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt Count, count1, table_size; OTV_ENTER; OTV_LIMIT_CHECK( 2 ); Count = FT_NEXT_USHORT( p ); OTV_TRACE(( " (Count = %d)\n", Count )); OTV_LIMIT_CHECK( Count * valid->extra1 * 2 ); table_size = Count * valid->extra1 * 2 + 2; for ( ; Count > 0; Count-- ) for ( count1 = valid->extra1; count1 > 0; count1-- ) { OTV_OPTIONAL_TABLE( anchor_offset ); OTV_OPTIONAL_OFFSET( anchor_offset ); if ( valid->extra2 ) { OTV_SIZE_CHECK( anchor_offset ); if ( anchor_offset ) otv_Anchor_validate( table + anchor_offset, valid ); } else otv_Anchor_validate( table + anchor_offset, valid ); } OTV_EXIT; } #define MarkBasePosFormat1Func otv_u_O_O_u_O_O #define MarkLigPosFormat1Func otv_u_O_O_u_O_O #define MarkMarkPosFormat1Func otv_u_O_O_u_O_O /* sets valid->extra1 (class count) */ static void otv_u_O_O_u_O_O( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt Coverage1, Coverage2, ClassCount; FT_UInt Array1, Array2; OTV_Validate_Func func; OTV_ENTER; p += 2; /* skip PosFormat */ OTV_LIMIT_CHECK( 10 ); Coverage1 = FT_NEXT_USHORT( p ); Coverage2 = FT_NEXT_USHORT( p ); ClassCount = FT_NEXT_USHORT( p ); Array1 = FT_NEXT_USHORT( p ); Array2 = FT_NEXT_USHORT( p ); otv_Coverage_validate( table + Coverage1, valid, -1 ); otv_Coverage_validate( table + Coverage2, valid, -1 ); otv_MarkArray_validate( table + Array1, valid ); valid->nesting_level++; func = valid->func[valid->nesting_level]; valid->extra1 = ClassCount; func( table + Array2, valid ); valid->nesting_level--; OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** VALUE RECORDS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static FT_UInt otv_value_length( FT_UInt format ) { FT_UInt count; count = ( ( format & 0xAA ) >> 1 ) + ( format & 0x55 ); count = ( ( count & 0xCC ) >> 2 ) + ( count & 0x33 ); count = ( ( count & 0xF0 ) >> 4 ) + ( count & 0x0F ); return count * 2; } /* uses valid->extra3 (pointer to base table) */ static void otv_ValueRecord_validate( FT_Bytes table, FT_UInt format, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt count; #ifdef FT_DEBUG_LEVEL_TRACE FT_Int loop; FT_ULong res = 0; OTV_NAME_ENTER( "ValueRecord" ); /* display `format' in dual representation */ for ( loop = 7; loop >= 0; loop-- ) { res <<= 4; res += ( format >> loop ) & 1; } OTV_TRACE(( " (format 0b%08lx)\n", res )); #endif if ( format >= 0x100 ) FT_INVALID_FORMAT; for ( count = 4; count > 0; count-- ) { if ( format & 1 ) { /* XPlacement, YPlacement, XAdvance, YAdvance */ OTV_LIMIT_CHECK( 2 ); p += 2; } format >>= 1; } for ( count = 4; count > 0; count-- ) { if ( format & 1 ) { FT_PtrDist table_size; OTV_OPTIONAL_TABLE( device ); /* XPlaDevice, YPlaDevice, XAdvDevice, YAdvDevice */ OTV_LIMIT_CHECK( 2 ); OTV_OPTIONAL_OFFSET( device ); /* XXX: this value is usually too small, especially if the current */ /* ValueRecord is part of an array -- getting the correct table */ /* size is probably not worth the trouble */ table_size = p - valid->extra3; OTV_SIZE_CHECK( device ); if ( device ) otv_Device_validate( valid->extra3 + device, valid ); } format >>= 1; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** ANCHORS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void otv_Anchor_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt AnchorFormat; OTV_NAME_ENTER( "Anchor"); OTV_LIMIT_CHECK( 6 ); AnchorFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", AnchorFormat )); p += 4; /* skip XCoordinate and YCoordinate */ switch ( AnchorFormat ) { case 1: break; case 2: OTV_LIMIT_CHECK( 2 ); /* AnchorPoint */ break; case 3: { FT_UInt table_size; OTV_OPTIONAL_TABLE( XDeviceTable ); OTV_OPTIONAL_TABLE( YDeviceTable ); OTV_LIMIT_CHECK( 4 ); OTV_OPTIONAL_OFFSET( XDeviceTable ); OTV_OPTIONAL_OFFSET( YDeviceTable ); table_size = 6 + 4; OTV_SIZE_CHECK( XDeviceTable ); if ( XDeviceTable ) otv_Device_validate( table + XDeviceTable, valid ); OTV_SIZE_CHECK( YDeviceTable ); if ( YDeviceTable ) otv_Device_validate( table + YDeviceTable, valid ); } break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** MARK ARRAYS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void otv_MarkArray_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt MarkCount; OTV_NAME_ENTER( "MarkArray" ); OTV_LIMIT_CHECK( 2 ); MarkCount = FT_NEXT_USHORT( p ); OTV_TRACE(( " (MarkCount = %d)\n", MarkCount )); OTV_LIMIT_CHECK( MarkCount * 4 ); /* MarkRecord */ for ( ; MarkCount > 0; MarkCount-- ) { p += 2; /* skip Class */ /* MarkAnchor */ otv_Anchor_validate( table + FT_NEXT_USHORT( p ), valid ); } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 1 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->extra3 (pointer to base table) */ static void otv_SinglePos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "SinglePos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); valid->extra3 = table; switch ( PosFormat ) { case 1: /* SinglePosFormat1 */ { FT_UInt Coverage, ValueFormat; OTV_LIMIT_CHECK( 4 ); Coverage = FT_NEXT_USHORT( p ); ValueFormat = FT_NEXT_USHORT( p ); otv_Coverage_validate( table + Coverage, valid, -1 ); otv_ValueRecord_validate( p, ValueFormat, valid ); /* Value */ } break; case 2: /* SinglePosFormat2 */ { FT_UInt Coverage, ValueFormat, ValueCount, len_value; OTV_LIMIT_CHECK( 6 ); Coverage = FT_NEXT_USHORT( p ); ValueFormat = FT_NEXT_USHORT( p ); ValueCount = FT_NEXT_USHORT( p ); OTV_TRACE(( " (ValueCount = %d)\n", ValueCount )); len_value = otv_value_length( ValueFormat ); otv_Coverage_validate( table + Coverage, valid, ValueCount ); OTV_LIMIT_CHECK( ValueCount * len_value ); /* Value */ for ( ; ValueCount > 0; ValueCount-- ) { otv_ValueRecord_validate( p, ValueFormat, valid ); p += len_value; } } break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 2 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void otv_PairSet_validate( FT_Bytes table, FT_UInt format1, FT_UInt format2, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt value_len1, value_len2, PairValueCount; OTV_NAME_ENTER( "PairSet" ); OTV_LIMIT_CHECK( 2 ); PairValueCount = FT_NEXT_USHORT( p ); OTV_TRACE(( " (PairValueCount = %d)\n", PairValueCount )); value_len1 = otv_value_length( format1 ); value_len2 = otv_value_length( format2 ); OTV_LIMIT_CHECK( PairValueCount * ( value_len1 + value_len2 + 2 ) ); /* PairValueRecord */ for ( ; PairValueCount > 0; PairValueCount-- ) { p += 2; /* skip SecondGlyph */ if ( format1 ) otv_ValueRecord_validate( p, format1, valid ); /* Value1 */ p += value_len1; if ( format2 ) otv_ValueRecord_validate( p, format2, valid ); /* Value2 */ p += value_len2; } OTV_EXIT; } /* sets valid->extra3 (pointer to base table) */ static void otv_PairPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "PairPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); valid->extra3 = table; switch ( PosFormat ) { case 1: /* PairPosFormat1 */ { FT_UInt Coverage, ValueFormat1, ValueFormat2, PairSetCount; OTV_LIMIT_CHECK( 8 ); Coverage = FT_NEXT_USHORT( p ); ValueFormat1 = FT_NEXT_USHORT( p ); ValueFormat2 = FT_NEXT_USHORT( p ); PairSetCount = FT_NEXT_USHORT( p ); OTV_TRACE(( " (PairSetCount = %d)\n", PairSetCount )); otv_Coverage_validate( table + Coverage, valid, -1 ); OTV_LIMIT_CHECK( PairSetCount * 2 ); /* PairSetOffset */ for ( ; PairSetCount > 0; PairSetCount-- ) otv_PairSet_validate( table + FT_NEXT_USHORT( p ), ValueFormat1, ValueFormat2, valid ); } break; case 2: /* PairPosFormat2 */ { FT_UInt Coverage, ValueFormat1, ValueFormat2, ClassDef1, ClassDef2; FT_UInt ClassCount1, ClassCount2, len_value1, len_value2, count; OTV_LIMIT_CHECK( 14 ); Coverage = FT_NEXT_USHORT( p ); ValueFormat1 = FT_NEXT_USHORT( p ); ValueFormat2 = FT_NEXT_USHORT( p ); ClassDef1 = FT_NEXT_USHORT( p ); ClassDef2 = FT_NEXT_USHORT( p ); ClassCount1 = FT_NEXT_USHORT( p ); ClassCount2 = FT_NEXT_USHORT( p ); OTV_TRACE(( " (ClassCount1 = %d)\n", ClassCount1 )); OTV_TRACE(( " (ClassCount2 = %d)\n", ClassCount2 )); len_value1 = otv_value_length( ValueFormat1 ); len_value2 = otv_value_length( ValueFormat2 ); otv_Coverage_validate( table + Coverage, valid, -1 ); otv_ClassDef_validate( table + ClassDef1, valid ); otv_ClassDef_validate( table + ClassDef2, valid ); OTV_LIMIT_CHECK( ClassCount1 * ClassCount2 * ( len_value1 + len_value2 ) ); /* Class1Record */ for ( ; ClassCount1 > 0; ClassCount1-- ) { /* Class2Record */ for ( count = ClassCount2; count > 0; count-- ) { if ( ValueFormat1 ) /* Value1 */ otv_ValueRecord_validate( p, ValueFormat1, valid ); p += len_value1; if ( ValueFormat2 ) /* Value2 */ otv_ValueRecord_validate( p, ValueFormat2, valid ); p += len_value2; } } } break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 3 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void otv_CursivePos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "CursivePos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: /* CursivePosFormat1 */ { FT_UInt table_size; FT_UInt Coverage, EntryExitCount; OTV_OPTIONAL_TABLE( EntryAnchor ); OTV_OPTIONAL_TABLE( ExitAnchor ); OTV_LIMIT_CHECK( 4 ); Coverage = FT_NEXT_USHORT( p ); EntryExitCount = FT_NEXT_USHORT( p ); OTV_TRACE(( " (EntryExitCount = %d)\n", EntryExitCount )); otv_Coverage_validate( table + Coverage, valid, EntryExitCount ); OTV_LIMIT_CHECK( EntryExitCount * 4 ); table_size = EntryExitCount * 4 + 4; /* EntryExitRecord */ for ( ; EntryExitCount > 0; EntryExitCount-- ) { OTV_OPTIONAL_OFFSET( EntryAnchor ); OTV_OPTIONAL_OFFSET( ExitAnchor ); OTV_SIZE_CHECK( EntryAnchor ); if ( EntryAnchor ) otv_Anchor_validate( table + EntryAnchor, valid ); OTV_SIZE_CHECK( ExitAnchor ); if ( ExitAnchor ) otv_Anchor_validate( table + ExitAnchor, valid ); } } break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 4 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* UNDOCUMENTED (in OpenType 1.5): */ /* BaseRecord tables can contain NULL pointers. */ /* sets valid->extra2 (1) */ static void otv_MarkBasePos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "MarkBasePos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: valid->extra2 = 1; OTV_NEST2( MarkBasePosFormat1, BaseArray ); OTV_RUN( table, valid ); break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 5 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->extra2 (1) */ static void otv_MarkLigPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "MarkLigPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: valid->extra2 = 1; OTV_NEST3( MarkLigPosFormat1, LigatureArray, LigatureAttach ); OTV_RUN( table, valid ); break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 6 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->extra2 (0) */ static void otv_MarkMarkPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "MarkMarkPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: valid->extra2 = 0; OTV_NEST2( MarkMarkPosFormat1, Mark2Array ); OTV_RUN( table, valid ); break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 7 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->extra1 (lookup count) */ static void otv_ContextPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "ContextPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: /* no need to check glyph indices/classes used as input for these */ /* context rules since even invalid glyph indices/classes return */ /* meaningful results */ valid->extra1 = valid->lookup_count; OTV_NEST3( ContextPosFormat1, PosRuleSet, PosRule ); OTV_RUN( table, valid ); break; case 2: /* no need to check glyph indices/classes used as input for these */ /* context rules since even invalid glyph indices/classes return */ /* meaningful results */ OTV_NEST3( ContextPosFormat2, PosClassSet, PosClassRule ); OTV_RUN( table, valid ); break; case 3: OTV_NEST1( ContextPosFormat3 ); OTV_RUN( table, valid ); break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 8 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->extra1 (lookup count) */ static void otv_ChainContextPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "ChainContextPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: /* no need to check glyph indices/classes used as input for these */ /* context rules since even invalid glyph indices/classes return */ /* meaningful results */ valid->extra1 = valid->lookup_count; OTV_NEST3( ChainContextPosFormat1, ChainPosRuleSet, ChainPosRule ); OTV_RUN( table, valid ); break; case 2: /* no need to check glyph indices/classes used as input for these */ /* context rules since even invalid glyph indices/classes return */ /* meaningful results */ OTV_NEST3( ChainContextPosFormat2, ChainPosClassSet, ChainPosClassRule ); OTV_RUN( table, valid ); break; case 3: OTV_NEST1( ChainContextPosFormat3 ); OTV_RUN( table, valid ); break; default: FT_INVALID_FORMAT; } OTV_EXIT; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS LOOKUP TYPE 9 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* uses valid->type_funcs */ static void otv_ExtensionPos_validate( FT_Bytes table, OTV_Validator valid ) { FT_Bytes p = table; FT_UInt PosFormat; OTV_NAME_ENTER( "ExtensionPos" ); OTV_LIMIT_CHECK( 2 ); PosFormat = FT_NEXT_USHORT( p ); OTV_TRACE(( " (format %d)\n", PosFormat )); switch ( PosFormat ) { case 1: /* ExtensionPosFormat1 */ { FT_UInt ExtensionLookupType; FT_ULong ExtensionOffset; OTV_Validate_Func validate; OTV_LIMIT_CHECK( 6 ); ExtensionLookupType = FT_NEXT_USHORT( p ); ExtensionOffset = FT_NEXT_ULONG( p ); if ( ExtensionLookupType == 0 || ExtensionLookupType >= 9 ) FT_INVALID_DATA; validate = valid->type_funcs[ExtensionLookupType - 1]; validate( table + ExtensionOffset, valid ); } break; default: FT_INVALID_FORMAT; } OTV_EXIT; } static const OTV_Validate_Func otv_gpos_validate_funcs[9] = { otv_SinglePos_validate, otv_PairPos_validate, otv_CursivePos_validate, otv_MarkBasePos_validate, otv_MarkLigPos_validate, otv_MarkMarkPos_validate, otv_ContextPos_validate, otv_ChainContextPos_validate, otv_ExtensionPos_validate }; /* sets valid->type_count */ /* sets valid->type_funcs */ FT_LOCAL_DEF( void ) otv_GPOS_subtable_validate( FT_Bytes table, OTV_Validator valid ) { valid->type_count = 9; valid->type_funcs = (OTV_Validate_Func*)otv_gpos_validate_funcs; otv_Lookup_validate( table, valid ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GPOS TABLE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* sets valid->glyph_count */ FT_LOCAL_DEF( void ) otv_GPOS_validate( FT_Bytes table, FT_UInt glyph_count, FT_Validator ftvalid ) { OTV_ValidatorRec validrec; OTV_Validator valid = &validrec; FT_Bytes p = table; FT_UInt ScriptList, FeatureList, LookupList; valid->root = ftvalid; FT_TRACE3(( "validating GPOS table\n" )); OTV_INIT; OTV_LIMIT_CHECK( 10 ); if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */ FT_INVALID_FORMAT; ScriptList = FT_NEXT_USHORT( p ); FeatureList = FT_NEXT_USHORT( p ); LookupList = FT_NEXT_USHORT( p ); valid->type_count = 9; valid->type_funcs = (OTV_Validate_Func*)otv_gpos_validate_funcs; valid->glyph_count = glyph_count; otv_LookupList_validate( table + LookupList, valid ); otv_FeatureList_validate( table + FeatureList, table + LookupList, valid ); otv_ScriptList_validate( table + ScriptList, table + FeatureList, valid ); FT_TRACE4(( "\n" )); } /* END */