src/gxvalid/gxvfeat.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvfeat.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT feat table validation (body).                         */
   6 /*                                                                         */
   7 /*  Copyright 2004, 2005, 2008, 2012 by                                    */
   8 /*  suzuki toshiya, Masatake YAMATO, Red Hat K.K.,                         */
   9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  10 /*                                                                         */
  11 /*  This file is part of the FreeType project, and may only be used,       */
  12 /*  modified, and distributed under the terms of the FreeType project      */
  13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  14 /*  this file you indicate that you have read the license and              */
  15 /*  understand and accept it fully.                                        */
  16 /*                                                                         */
  17 /***************************************************************************/
  18
  19 /***************************************************************************/
  20 /*                                                                         */
  21 /* gxvalid is derived from both gxlayout module and otvalid module.        */
  22 /* Development of gxlayout is supported by the Information-technology      */
  23 /* Promotion Agency(IPA), Japan.                                           */
  24 /*                                                                         */
  25 /***************************************************************************/
  26
  27
  28 #include "gxvalid.h"
  29 #include "gxvcommn.h"
  30 #include "gxvfeat.h"
  31
  32
  33   /*************************************************************************/
  34   /*                                                                       */
  35   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  36   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  37   /* messages during execution.                                            */
  38   /*                                                                       */
  39 #undef  FT_COMPONENT
  40 #define FT_COMPONENT  trace_gxvfeat
  41
  42
  43   /*************************************************************************/
  44   /*************************************************************************/
  45   /*****                                                               *****/
  46   /*****                      Data and Types                           *****/
  47   /*****                                                               *****/
  48   /*************************************************************************/
  49   /*************************************************************************/
  50
  51   typedef struct  GXV_feat_DataRec_
  52   {
  53     FT_UInt    reserved_size;
  54     FT_UShort  feature;
  55     FT_UShort  setting;
  56
  57   } GXV_feat_DataRec, *GXV_feat_Data;
  58
  59
  60 #define GXV_FEAT_DATA( field )  GXV_TABLE_DATA( feat, field )
  61
  62
  63   typedef enum  GXV_FeatureFlagsMask_
  64   {
  65     GXV_FEAT_MASK_EXCLUSIVE_SETTINGS = 0x8000U,
  66     GXV_FEAT_MASK_DYNAMIC_DEFAULT    = 0x4000,
  67     GXV_FEAT_MASK_UNUSED             = 0x3F00,
  68     GXV_FEAT_MASK_DEFAULT_SETTING    = 0x00FF
  69
  70   } GXV_FeatureFlagsMask;
  71
  72
  73   /*************************************************************************/
  74   /*************************************************************************/
  75   /*****                                                               *****/
  76   /*****                      UTILITY FUNCTIONS                        *****/
  77   /*****                                                               *****/
  78   /*************************************************************************/
  79   /*************************************************************************/
  80
  81   static void
  82   gxv_feat_registry_validate( FT_UShort      feature,
  83                               FT_UShort      nSettings,
  84                               FT_Bool        exclusive,
  85                               GXV_Validator  gxvalid )
  86   {
  87     GXV_NAME_ENTER( "feature in registry" );
  88
  89     GXV_TRACE(( " (feature = %u)\n", feature ));
  90
  91     if ( feature >= gxv_feat_registry_length )
  92     {
  93       GXV_TRACE(( "feature number %d is out of range %d\n",
  94                   feature, gxv_feat_registry_length ));
  95       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
  96       goto Exit;
  97     }
  98
  99     if ( gxv_feat_registry[feature].existence == 0 )
 100     {
 101       GXV_TRACE(( "feature number %d is in defined range but doesn't exist\n",
 102                   feature ));
 103       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 104       goto Exit;
 105     }
 106
 107     if ( gxv_feat_registry[feature].apple_reserved )
 108     {
 109       /* Don't use here. Apple is reserved. */
 110       GXV_TRACE(( "feature number %d is reserved by Apple\n", feature ));
 111       if ( gxvalid->root->level >= FT_VALIDATE_TIGHT )
 112         FT_INVALID_DATA;
 113     }
 114
 115     if ( nSettings != gxv_feat_registry[feature].nSettings )
 116     {
 117       GXV_TRACE(( "feature %d: nSettings %d != defined nSettings %d\n",
 118                   feature, nSettings,
 119                   gxv_feat_registry[feature].nSettings ));
 120       if ( gxvalid->root->level >= FT_VALIDATE_TIGHT )
 121         FT_INVALID_DATA;
 122     }
 123
 124     if ( exclusive != gxv_feat_registry[feature].exclusive )
 125     {
 126       GXV_TRACE(( "exclusive flag %d differs from predefined value\n",
 127                   exclusive ));
 128       if ( gxvalid->root->level >= FT_VALIDATE_TIGHT )
 129         FT_INVALID_DATA;
 130     }
 131
 132   Exit:
 133     GXV_EXIT;
 134   }
 135
 136
 137   static void
 138   gxv_feat_name_index_validate( FT_Bytes       table,
 139                                 FT_Bytes       limit,
 140                                 GXV_Validator  gxvalid )
 141   {
 142     FT_Bytes  p = table;
 143
 144     FT_Short  nameIndex;
 145
 146
 147     GXV_NAME_ENTER( "nameIndex" );
 148
 149     GXV_LIMIT_CHECK( 2 );
 150     nameIndex = FT_NEXT_SHORT ( p );
 151     GXV_TRACE(( " (nameIndex = %d)\n", nameIndex ));
 152
 153     gxv_sfntName_validate( (FT_UShort)nameIndex,
 154                            255,
 155                            32768U,
 156                            gxvalid );
 157
 158     GXV_EXIT;
 159   }
 160
 161
 162   static void
 163   gxv_feat_setting_validate( FT_Bytes       table,
 164                              FT_Bytes       limit,
 165                              FT_Bool        exclusive,
 166                              GXV_Validator  gxvalid )
 167   {
 168     FT_Bytes   p = table;
 169     FT_UShort  setting;
 170
 171
 172     GXV_NAME_ENTER( "setting" );
 173
 174     GXV_LIMIT_CHECK( 2 );
 175
 176     setting = FT_NEXT_USHORT( p );
 177
 178     /* If we have exclusive setting, the setting should be odd. */
 179     if ( exclusive && ( setting & 1 ) == 0 )
 180       FT_INVALID_DATA;
 181
 182     gxv_feat_name_index_validate( p, limit, gxvalid );
 183
 184     GXV_FEAT_DATA( setting ) = setting;
 185
 186     GXV_EXIT;
 187   }
 188
 189
 190   static void
 191   gxv_feat_name_validate( FT_Bytes       table,
 192                           FT_Bytes       limit,
 193                           GXV_Validator  gxvalid )
 194   {
 195     FT_Bytes   p             = table;
 196     FT_UInt    reserved_size = GXV_FEAT_DATA( reserved_size );
 197
 198     FT_UShort  feature;
 199     FT_UShort  nSettings;
 200     FT_ULong   settingTable;
 201     FT_UShort  featureFlags;
 202
 203     FT_Bool    exclusive;
 204     FT_Int     last_setting;
 205     FT_UInt    i;
 206
 207
 208     GXV_NAME_ENTER( "name" );
 209
 210     /* feature + nSettings + settingTable + featureFlags */
 211     GXV_LIMIT_CHECK( 2 + 2 + 4 + 2 );
 212
 213     feature = FT_NEXT_USHORT( p );
 214     GXV_FEAT_DATA( feature ) = feature;
 215
 216     nSettings    = FT_NEXT_USHORT( p );
 217     settingTable = FT_NEXT_ULONG ( p );
 218     featureFlags = FT_NEXT_USHORT( p );
 219
 220     if ( settingTable < reserved_size )
 221       FT_INVALID_OFFSET;
 222
 223     if ( ( featureFlags & GXV_FEAT_MASK_UNUSED ) == 0 )
 224       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 225
 226     exclusive = FT_BOOL( featureFlags & GXV_FEAT_MASK_EXCLUSIVE_SETTINGS );
 227     if ( exclusive )
 228     {
 229       FT_Byte  dynamic_default;
 230
 231
 232       if ( featureFlags & GXV_FEAT_MASK_DYNAMIC_DEFAULT )
 233         dynamic_default = (FT_Byte)( featureFlags &
 234                                      GXV_FEAT_MASK_DEFAULT_SETTING );
 235       else
 236         dynamic_default = 0;
 237
 238       /* If exclusive, check whether default setting is in the range. */
 239       if ( !( dynamic_default < nSettings ) )
 240         FT_INVALID_FORMAT;
 241     }
 242
 243     gxv_feat_registry_validate( feature, nSettings, exclusive, gxvalid );
 244
 245     gxv_feat_name_index_validate( p, limit, gxvalid );
 246
 247     p = gxvalid->root->base + settingTable;
 248     for ( last_setting = -1, i = 0; i < nSettings; i++ )
 249     {
 250       gxv_feat_setting_validate( p, limit, exclusive, gxvalid );
 251
 252       if ( (FT_Int)GXV_FEAT_DATA( setting ) <= last_setting )
 253         GXV_SET_ERR_IF_PARANOID( FT_INVALID_FORMAT );
 254
 255       last_setting = (FT_Int)GXV_FEAT_DATA( setting );
 256       /* setting + nameIndex */
 257       p += ( 2 + 2 );
 258     }
 259
 260     GXV_EXIT;
 261   }
 262
 263
 264   /*************************************************************************/
 265   /*************************************************************************/
 266   /*****                                                               *****/
 267   /*****                         feat TABLE                            *****/
 268   /*****                                                               *****/
 269   /*************************************************************************/
 270   /*************************************************************************/
 271
 272   FT_LOCAL_DEF( void )
 273   gxv_feat_validate( FT_Bytes      table,
 274                      FT_Face       face,
 275                      FT_Validator  ftvalid )
 276   {
 277     GXV_ValidatorRec  gxvalidrec;
 278     GXV_Validator     gxvalid = &gxvalidrec;
 279
 280     GXV_feat_DataRec  featrec;
 281     GXV_feat_Data     feat = &featrec;
 282
 283     FT_Bytes          p     = table;
 284     FT_Bytes          limit = 0;
 285
 286     FT_UInt           featureNameCount;
 287
 288     FT_UInt           i;
 289     FT_Int            last_feature;
 290
 291
 292     gxvalid->root       = ftvalid;
 293     gxvalid->table_data = feat;
 294     gxvalid->face       = face;
 295
 296     FT_TRACE3(( "validating `feat' table\n" ));
 297     GXV_INIT;
 298
 299     feat->reserved_size = 0;
 300
 301     /* version + featureNameCount + none_0 + none_1  */
 302     GXV_LIMIT_CHECK( 4 + 2 + 2 + 4 );
 303     feat->reserved_size += 4 + 2 + 2 + 4;
 304
 305     if ( FT_NEXT_ULONG( p ) != 0x00010000UL ) /* Version */
 306       FT_INVALID_FORMAT;
 307
 308     featureNameCount = FT_NEXT_USHORT( p );
 309     GXV_TRACE(( " (featureNameCount = %d)\n", featureNameCount ));
 310
 311     if ( !( IS_PARANOID_VALIDATION ) )
 312       p += 6; /* skip (none) and (none) */
 313     else
 314     {
 315       if ( FT_NEXT_USHORT( p ) != 0 )
 316         FT_INVALID_DATA;
 317
 318       if ( FT_NEXT_ULONG( p )  != 0 )
 319         FT_INVALID_DATA;
 320     }
 321
 322     feat->reserved_size += featureNameCount * ( 2 + 2 + 4 + 2 + 2 );
 323
 324     for ( last_feature = -1, i = 0; i < featureNameCount; i++ )
 325     {
 326       gxv_feat_name_validate( p, limit, gxvalid );
 327
 328       if ( (FT_Int)GXV_FEAT_DATA( feature ) <= last_feature )
 329         GXV_SET_ERR_IF_PARANOID( FT_INVALID_FORMAT );
 330
 331       last_feature = GXV_FEAT_DATA( feature );
 332       p += 2 + 2 + 4 + 2 + 2;
 333     }
 334
 335     FT_TRACE4(( "\n" ));
 336   }
 337
 338
 339 /* END */