/***************************************************************************/ /* */ /* gxvprop.c */ /* */ /* TrueTypeGX/AAT prop 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" /*************************************************************************/ /* */ /* 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_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 0x8000 #define GXV_PROP_USE_COMPLEMENTARY_BRACKET 0x1000 #define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00 #define GXV_PROP_ATTACHING_TO_RIGHT 0x0080 #define GXV_PROP_RESERVED 0x0060 #define GXV_PROP_DIRECTIONALITY_CLASS 0x001F /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** UTILITY FUNCTIONS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void gxv_prop_zero_advance_validate( FT_UShort gid, GXV_Validator valid ) { FT_Face face; FT_Error error; FT_GlyphSlot glyph; GXV_NAME_ENTER(" zero advance " ); face = valid->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 ) 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 valid ) { if ( glyph != 0 && ( property & GXV_PROP_FLOATER ) ) { gxv_prop_zero_advance_validate( glyph, valid ); } if ( property & GXV_PROP_USE_COMPLEMENTARY_BRACKET ) { FT_UShort offset; char complement; offset = property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET; if ( offset == 0 ) FT_INVALID_DATA; complement = offset >> 8; if ( complement & 0x08 ) { /* Top bit is set: nagative */ /* Calculated the absolute offset */ complement = ( complement & 0x07 ) + 1; /* The gid for complement must be greater than 0 */ if ( glyph <= complement ) FT_INVALID_DATA; } else { /* The gid for complement must be the face. */ gxv_glyphid_validate( glyph + complement, valid ); } } else { if ( ( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET ) ) GXV_TRACE(( "glyph %d cannot have complementary bracketing\n", glyph )); } /* this is introduced in ver 2.0 */ if ( property & GXV_PROP_ATTACHING_TO_RIGHT ) { if ( GXV_PROP_DATA( version ) == 0x00010000 ) FT_INVALID_DATA; } if ( property & GXV_PROP_RESERVED ) { FT_INVALID_DATA; } if ( ( property & GXV_PROP_DIRECTIONALITY_CLASS ) > 11 ) { /* TODO: Too restricted. Use the validation level. */ if ( GXV_PROP_DATA( version ) == 0x00010000 || GXV_PROP_DATA( version ) == 0x00020000 ) FT_INVALID_DATA; } } static void gxv_prop_LookupValue_validate( FT_UShort glyph, GXV_LookupValueDesc value, GXV_Validator valid ) { gxv_prop_property_validate( value.u, glyph, valid ); } /* +===============+ --------+ | 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_LookupValueDesc base_value, FT_Bytes lookuptbl_limit, GXV_Validator valid ) { FT_Bytes p; FT_Bytes limit; FT_UShort offset; GXV_LookupValueDesc value; offset = base_value.u + ( relative_gindex * sizeof( FT_UShort ) ); p = valid->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 validrec; GXV_Validator valid = &validrec; GXV_prop_DataRec proprec; GXV_prop_Data prop = &proprec; FT_Fixed version; FT_UShort format; FT_UShort defaultProp; valid->root = ftvalid; valid->table_data = prop; valid->face = face; FT_TRACE3(( "validation prop table\n" )); GXV_INIT; GXV_LIMIT_CHECK( 4 + 2 + 2 ); version = FT_NEXT_ULONG( p ); format = FT_NEXT_USHORT( p ); defaultProp = FT_NEXT_USHORT( p ); /* version 1.0, 2.0, 3.0 are only defined (1996) */ if ( version != 0x00010000 && version != 0x00020000 && version != 0x00030000 ) FT_INVALID_FORMAT; /* format 0x0000, 0x0001 are only defined (1996) */ if ( format > 1 ) FT_INVALID_FORMAT; gxv_prop_property_validate( defaultProp, 0, valid ); if ( format == 0 ) { FT_TRACE3(( "(format 0, no per-glyph properties, " "rest %d bytes are skipped)", limit - p )); goto Exit; } /* format == 1 */ GXV_PROP_DATA( version ) = version; valid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED; valid->lookupval_func = gxv_prop_LookupValue_validate; valid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit; gxv_LookupTable_validate( p, limit, valid ); Exit: FT_TRACE4(( "\n" )); } /* END */