src/third_party/freetype2/src/src/gxvalid/gxvprop.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvprop.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT prop table validation (body).                         */
   6 /*                                                                         */
   7 /*  Copyright 2004, 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18 /***************************************************************************/
  19 /*                                                                         */
  20 /* gxvalid is derived from both gxlayout module and otvalid module.        */
  21 /* Development of gxlayout is supported by the Information-technology      */
  22 /* Promotion Agency(IPA), Japan.                                           */
  23 /*                                                                         */
  24 /***************************************************************************/
  25
  26
  27 #include "gxvalid.h"
  28 #include "gxvcommn.h"
  29
  30
  31   /*************************************************************************/
  32   /*                                                                       */
  33   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  34   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  35   /* messages during execution.                                            */
  36   /*                                                                       */
  37 #undef  FT_COMPONENT
  38 #define FT_COMPONENT  trace_gxvprop
  39
  40
  41   /*************************************************************************/
  42   /*************************************************************************/
  43   /*****                                                               *****/
  44   /*****                      Data and Types                           *****/
  45   /*****                                                               *****/
  46   /*************************************************************************/
  47   /*************************************************************************/
  48
  49 #define GXV_PROP_HEADER_SIZE  ( 4 + 2 + 2 )
  50 #define GXV_PROP_SIZE_MIN     GXV_PROP_HEADER_SIZE
  51
  52   typedef struct  GXV_prop_DataRec_
  53   {
  54     FT_Fixed  version;
  55
  56   } GXV_prop_DataRec, *GXV_prop_Data;
  57
  58 #define GXV_PROP_DATA( field )  GXV_TABLE_DATA( prop, field )
  59
  60 #define GXV_PROP_FLOATER                      0x8000U
  61 #define GXV_PROP_USE_COMPLEMENTARY_BRACKET    0x1000U
  62 #define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00U
  63 #define GXV_PROP_ATTACHING_TO_RIGHT           0x0080U
  64 #define GXV_PROP_RESERVED                     0x0060U
  65 #define GXV_PROP_DIRECTIONALITY_CLASS         0x001FU
  66
  67
  68   /*************************************************************************/
  69   /*************************************************************************/
  70   /*****                                                               *****/
  71   /*****                      UTILITY FUNCTIONS                        *****/
  72   /*****                                                               *****/
  73   /*************************************************************************/
  74   /*************************************************************************/
  75
  76   static void
  77   gxv_prop_zero_advance_validate( FT_UShort      gid,
  78                                   GXV_Validator  valid )
  79   {
  80     FT_Face       face;
  81     FT_Error      error;
  82     FT_GlyphSlot  glyph;
  83
  84
  85     GXV_NAME_ENTER( "zero advance" );
  86
  87     face = valid->face;
  88
  89     error = FT_Load_Glyph( face,
  90                            gid,
  91                            FT_LOAD_IGNORE_TRANSFORM );
  92     if ( error )
  93       FT_INVALID_GLYPH_ID;
  94
  95     glyph = face->glyph;
  96
  97     if ( glyph->advance.x != (FT_Pos)0 ||
  98          glyph->advance.y != (FT_Pos)0 )
  99     {
 100       GXV_TRACE(( "  found non-zero advance in zero-advance glyph\n" ));
 101       FT_INVALID_DATA;
 102     }
 103
 104     GXV_EXIT;
 105   }
 106
 107
 108   /* Pass 0 as GLYPH to check the default property */
 109   static void
 110   gxv_prop_property_validate( FT_UShort      property,
 111                               FT_UShort      glyph,
 112                               GXV_Validator  valid )
 113   {
 114     if ( glyph != 0 && ( property & GXV_PROP_FLOATER ) )
 115       gxv_prop_zero_advance_validate( glyph, valid );
 116
 117     if ( property & GXV_PROP_USE_COMPLEMENTARY_BRACKET )
 118     {
 119       FT_UShort  offset;
 120       char       complement;
 121
 122
 123       offset = (FT_UShort)( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET );
 124       if ( offset == 0 )
 125       {
 126         GXV_TRACE(( "  found zero offset to property\n" ));
 127         FT_INVALID_OFFSET;
 128       }
 129
 130       complement = (char)( offset >> 8 );
 131       if ( complement & 0x08 )
 132       {
 133         /* Top bit is set: negative */
 134
 135         /* Calculate the absolute offset */
 136         complement = (char)( ( complement & 0x07 ) + 1 );
 137
 138         /* The gid for complement must be greater than 0 */
 139         if ( glyph <= complement )
 140         {
 141           GXV_TRACE(( "  found non-positive glyph complement\n" ));
 142           FT_INVALID_DATA;
 143         }
 144       }
 145       else
 146       {
 147         /* The gid for complement must be the face. */
 148         gxv_glyphid_validate( (FT_UShort)( glyph + complement ), valid );
 149       }
 150     }
 151     else
 152     {
 153       if ( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET )
 154         GXV_TRACE(( "glyph %d cannot have complementary bracketing\n",
 155                     glyph ));
 156     }
 157
 158     /* this is introduced in version 2.0 */
 159     if ( property & GXV_PROP_ATTACHING_TO_RIGHT )
 160     {
 161       if ( GXV_PROP_DATA( version ) == 0x00010000UL )
 162       {
 163         GXV_TRACE(( "  found older version (1.0) in new version table\n" ));
 164         FT_INVALID_DATA;
 165       }
 166     }
 167
 168     if ( property & GXV_PROP_RESERVED )
 169     {
 170       GXV_TRACE(( "  found non-zero bits in reserved bits\n" ));
 171       FT_INVALID_DATA;
 172     }
 173
 174     if ( ( property & GXV_PROP_DIRECTIONALITY_CLASS ) > 11 )
 175     {
 176       /* TODO: Too restricted. Use the validation level. */
 177       if ( GXV_PROP_DATA( version ) == 0x00010000UL ||
 178            GXV_PROP_DATA( version ) == 0x00020000UL )
 179       {
 180         GXV_TRACE(( "  found too old version in directionality class\n" ));
 181         FT_INVALID_DATA;
 182       }
 183     }
 184   }
 185
 186
 187   static void
 188   gxv_prop_LookupValue_validate( FT_UShort            glyph,
 189                                  GXV_LookupValueCPtr  value_p,
 190                                  GXV_Validator        valid )
 191   {
 192     gxv_prop_property_validate( value_p->u, glyph, valid );
 193   }
 194
 195
 196   /*
 197     +===============+ --------+
 198     | lookup header |         |
 199     +===============+         |
 200     | BinSrchHeader |         |
 201     +===============+         |
 202     | lastGlyph[0]  |         |
 203     +---------------+         |
 204     | firstGlyph[0] |         |    head of lookup table
 205     +---------------+         |             +
 206     | offset[0]     |    ->   |          offset            [byte]
 207     +===============+         |             +
 208     | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
 209     +---------------+         |
 210     | firstGlyph[1] |         |
 211     +---------------+         |
 212     | offset[1]     |         |
 213     +===============+         |
 214                               |
 215      ...                      |
 216                               |
 217     16bit value array         |
 218     +===============+         |
 219     |     value     | <-------+
 220     ...
 221   */
 222
 223   static GXV_LookupValueDesc
 224   gxv_prop_LookupFmt4_transit( FT_UShort            relative_gindex,
 225                                GXV_LookupValueCPtr  base_value_p,
 226                                FT_Bytes             lookuptbl_limit,
 227                                GXV_Validator        valid )
 228   {
 229     FT_Bytes             p;
 230     FT_Bytes             limit;
 231     FT_UShort            offset;
 232     GXV_LookupValueDesc  value;
 233
 234     /* XXX: check range? */
 235     offset = (FT_UShort)( base_value_p->u +
 236                           relative_gindex * sizeof( FT_UShort ) );
 237     p      = valid->lookuptbl_head + offset;
 238     limit  = lookuptbl_limit;
 239
 240     GXV_LIMIT_CHECK ( 2 );
 241     value.u = FT_NEXT_USHORT( p );
 242
 243     return value;
 244   }
 245
 246
 247   /*************************************************************************/
 248   /*************************************************************************/
 249   /*****                                                               *****/
 250   /*****                         prop TABLE                            *****/
 251   /*****                                                               *****/
 252   /*************************************************************************/
 253   /*************************************************************************/
 254
 255   FT_LOCAL_DEF( void )
 256   gxv_prop_validate( FT_Bytes      table,
 257                      FT_Face       face,
 258                      FT_Validator  ftvalid )
 259   {
 260     FT_Bytes          p     = table;
 261     FT_Bytes          limit = 0;
 262     GXV_ValidatorRec  validrec;
 263     GXV_Validator     valid = &validrec;
 264
 265     GXV_prop_DataRec  proprec;
 266     GXV_prop_Data     prop = &proprec;
 267
 268     FT_Fixed          version;
 269     FT_UShort         format;
 270     FT_UShort         defaultProp;
 271
 272
 273     valid->root       = ftvalid;
 274     valid->table_data = prop;
 275     valid->face       = face;
 276
 277     FT_TRACE3(( "validating `prop' table\n" ));
 278     GXV_INIT;
 279
 280     GXV_LIMIT_CHECK( 4 + 2 + 2 );
 281     version     = FT_NEXT_ULONG( p );
 282     format      = FT_NEXT_USHORT( p );
 283     defaultProp = FT_NEXT_USHORT( p );
 284
 285     GXV_TRACE(( "  version 0x%08x\n", version ));
 286     GXV_TRACE(( "  format  0x%04x\n", format ));
 287     GXV_TRACE(( "  defaultProp  0x%04x\n", defaultProp ));
 288
 289     /* only versions 1.0, 2.0, 3.0 are defined (1996) */
 290     if ( version != 0x00010000UL &&
 291          version != 0x00020000UL &&
 292          version != 0x00030000UL )
 293     {
 294       GXV_TRACE(( "  found unknown version\n" ));
 295       FT_INVALID_FORMAT;
 296     }
 297
 298
 299     /* only formats 0x0000, 0x0001 are defined (1996) */
 300     if ( format > 1 )
 301     {
 302       GXV_TRACE(( "  found unknown format\n" ));
 303       FT_INVALID_FORMAT;
 304     }
 305
 306     gxv_prop_property_validate( defaultProp, 0, valid );
 307
 308     if ( format == 0 )
 309     {
 310       FT_TRACE3(( "(format 0, no per-glyph properties, "
 311                   "remaining %d bytes are skipped)", limit - p ));
 312       goto Exit;
 313     }
 314
 315     /* format == 1 */
 316     GXV_PROP_DATA( version ) = version;
 317
 318     valid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;
 319     valid->lookupval_func   = gxv_prop_LookupValue_validate;
 320     valid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit;
 321
 322     gxv_LookupTable_validate( p, limit, valid );
 323
 324   Exit:
 325     FT_TRACE4(( "\n" ));
 326   }
 327
 328
 329 /* END */