thirdparty/freetype-2.3.12/src/gxvalid/gxvtrak.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvtrak.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT trak 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_gxvtrak
  39
  40
  41   /*************************************************************************/
  42   /*************************************************************************/
  43   /*****                                                               *****/
  44   /*****                      Data and Types                           *****/
  45   /*****                                                               *****/
  46   /*************************************************************************/
  47   /*************************************************************************/
  48
  49     /*
  50      * referred track table format specification:
  51      * http://developer.apple.com/fonts/TTRefMan/RM06/Chap6trak.html
  52      * last update was 1996.
  53      * ----------------------------------------------
  54      * [MINIMUM HEADER]: GXV_TRAK_SIZE_MIN
  55      * version          (fixed:  32bit) = 0x00010000
  56      * format           (uint16: 16bit) = 0 is only defined (1996)
  57      * horizOffset      (uint16: 16bit)
  58      * vertOffset       (uint16: 16bit)
  59      * reserved         (uint16: 16bit) = 0
  60      * ----------------------------------------------
  61      * [VARIABLE BODY]:
  62      * horizData
  63      *   header         ( 2 + 2 + 4
  64      *   trackTable       + nTracks * ( 4 + 2 + 2 )
  65      *   sizeTable        + nSizes * 4 )
  66      * ----------------------------------------------
  67      * vertData
  68      *   header         ( 2 + 2 + 4
  69      *   trackTable       + nTracks * ( 4 + 2 + 2 )
  70      *   sizeTable        + nSizes * 4 )
  71      * ----------------------------------------------
  72      */
  73   typedef struct  GXV_trak_DataRec_
  74   {
  75     FT_UShort  trackValueOffset_min;
  76     FT_UShort  trackValueOffset_max;
  77
  78   } GXV_trak_DataRec, *GXV_trak_Data;
  79
  80
  81 #define GXV_TRAK_DATA( FIELD )  GXV_TABLE_DATA( trak, FIELD )
  82
  83
  84   /*************************************************************************/
  85   /*************************************************************************/
  86   /*****                                                               *****/
  87   /*****                      UTILITY FUNCTIONS                        *****/
  88   /*****                                                               *****/
  89   /*************************************************************************/
  90   /*************************************************************************/
  91
  92   static void
  93   gxv_trak_trackTable_validate( FT_Bytes       table,
  94                                 FT_Bytes       limit,
  95                                 FT_UShort      nTracks,
  96                                 GXV_Validator  valid )
  97   {
  98     FT_Bytes   p = table;
  99
 100     FT_Fixed   track;
 101     FT_UShort  nameIndex;
 102     FT_UShort  offset;
 103     FT_UShort  i;
 104
 105
 106     GXV_NAME_ENTER( "trackTable" );
 107
 108     GXV_TRAK_DATA( trackValueOffset_min ) = 0xFFFFU;
 109     GXV_TRAK_DATA( trackValueOffset_max ) = 0x0000;
 110
 111     for ( i = 0; i < nTracks; i ++ )
 112     {
 113       GXV_LIMIT_CHECK( 4 + 2 + 2 );
 114       track     = FT_NEXT_LONG( p );
 115       nameIndex = FT_NEXT_USHORT( p );
 116       offset    = FT_NEXT_USHORT( p );
 117
 118       if ( offset < GXV_TRAK_DATA( trackValueOffset_min ) )
 119         GXV_TRAK_DATA( trackValueOffset_min ) = offset;
 120       if ( offset > GXV_TRAK_DATA( trackValueOffset_max ) )
 121         GXV_TRAK_DATA( trackValueOffset_max ) = offset;
 122
 123       gxv_sfntName_validate( nameIndex, 256, 32767, valid );
 124     }
 125
 126     valid->subtable_length = p - table;
 127     GXV_EXIT;
 128   }
 129
 130
 131   static void
 132   gxv_trak_trackData_validate( FT_Bytes       table,
 133                                FT_Bytes       limit,
 134                                GXV_Validator  valid )
 135   {
 136     FT_Bytes   p = table;
 137     FT_UShort  nTracks;
 138     FT_UShort  nSizes;
 139     FT_ULong   sizeTableOffset;
 140
 141     GXV_ODTECT( 4, odtect );
 142
 143
 144     GXV_ODTECT_INIT( odtect );
 145     GXV_NAME_ENTER( "trackData" );
 146
 147     /* read the header of trackData */
 148     GXV_LIMIT_CHECK( 2 + 2 + 4 );
 149     nTracks         = FT_NEXT_USHORT( p );
 150     nSizes          = FT_NEXT_USHORT( p );
 151     sizeTableOffset = FT_NEXT_ULONG( p );
 152
 153     gxv_odtect_add_range( table, p - table, "trackData header", odtect );
 154
 155     /* validate trackTable */
 156     gxv_trak_trackTable_validate( p, limit, nTracks, valid );
 157     gxv_odtect_add_range( p, valid->subtable_length,
 158                           "trackTable", odtect );
 159
 160     /* sizeTable is array of FT_Fixed, don't check contents */
 161     p = valid->root->base + sizeTableOffset;
 162     GXV_LIMIT_CHECK( nSizes * 4 );
 163     gxv_odtect_add_range( p, nSizes * 4, "sizeTable", odtect );
 164
 165     /* validate trackValueOffet */
 166     p = valid->root->base + GXV_TRAK_DATA( trackValueOffset_min );
 167     if ( limit - p < nTracks * nSizes * 2 )
 168       GXV_TRACE(( "too short trackValue array\n" ));
 169
 170     p = valid->root->base + GXV_TRAK_DATA( trackValueOffset_max );
 171     GXV_LIMIT_CHECK( nSizes * 2 );
 172
 173     gxv_odtect_add_range( valid->root->base
 174                             + GXV_TRAK_DATA( trackValueOffset_min ),
 175                           GXV_TRAK_DATA( trackValueOffset_max )
 176                             - GXV_TRAK_DATA( trackValueOffset_min )
 177                             + nSizes * 2,
 178                           "trackValue array", odtect );
 179
 180     gxv_odtect_validate( odtect, valid );
 181
 182     GXV_EXIT;
 183   }
 184
 185
 186   /*************************************************************************/
 187   /*************************************************************************/
 188   /*****                                                               *****/
 189   /*****                          trak TABLE                           *****/
 190   /*****                                                               *****/
 191   /*************************************************************************/
 192   /*************************************************************************/
 193
 194   FT_LOCAL_DEF( void )
 195   gxv_trak_validate( FT_Bytes      table,
 196                      FT_Face       face,
 197                      FT_Validator  ftvalid )
 198   {
 199     FT_Bytes          p = table;
 200     FT_Bytes          limit = 0;
 201     FT_Offset         table_size;
 202
 203     GXV_ValidatorRec  validrec;
 204     GXV_Validator     valid = &validrec;
 205     GXV_trak_DataRec  trakrec;
 206     GXV_trak_Data     trak = &trakrec;
 207
 208     FT_ULong   version;
 209     FT_UShort  format;
 210     FT_UShort  horizOffset;
 211     FT_UShort  vertOffset;
 212     FT_UShort  reserved;
 213
 214
 215     GXV_ODTECT( 3, odtect );
 216
 217     GXV_ODTECT_INIT( odtect );
 218     valid->root       = ftvalid;
 219     valid->table_data = trak;
 220     valid->face       = face;
 221
 222     limit      = valid->root->limit;
 223     table_size = limit - table;
 224
 225     FT_TRACE3(( "validating `trak' table\n" ));
 226     GXV_INIT;
 227
 228     GXV_LIMIT_CHECK( 4 + 2 + 2 + 2 + 2 );
 229     version     = FT_NEXT_ULONG( p );
 230     format      = FT_NEXT_USHORT( p );
 231     horizOffset = FT_NEXT_USHORT( p );
 232     vertOffset  = FT_NEXT_USHORT( p );
 233     reserved    = FT_NEXT_USHORT( p );
 234
 235     GXV_TRACE(( " (version = 0x%08x)\n", version ));
 236     GXV_TRACE(( " (format = 0x%04x)\n", format ));
 237     GXV_TRACE(( " (horizOffset = 0x%04x)\n", horizOffset ));
 238     GXV_TRACE(( " (vertOffset = 0x%04x)\n", vertOffset ));
 239     GXV_TRACE(( " (reserved = 0x%04x)\n", reserved ));
 240
 241     /* Version 1.0 (always:1996) */
 242     if ( version != 0x00010000UL )
 243       FT_INVALID_FORMAT;
 244
 245     /* format 0 (always:1996) */
 246     if ( format != 0x0000 )
 247       FT_INVALID_FORMAT;
 248
 249     GXV_32BIT_ALIGNMENT_VALIDATE( horizOffset );
 250     GXV_32BIT_ALIGNMENT_VALIDATE( vertOffset );
 251
 252     /* Reserved Fixed Value (always) */
 253     if ( reserved != 0x0000 )
 254       FT_INVALID_DATA;
 255
 256     /* validate trackData */
 257     if ( 0 < horizOffset )
 258     {
 259       gxv_trak_trackData_validate( table + horizOffset, limit, valid );
 260       gxv_odtect_add_range( table + horizOffset, valid->subtable_length,
 261                             "horizJustData", odtect );
 262     }
 263
 264     if ( 0 < vertOffset )
 265     {
 266       gxv_trak_trackData_validate( table + vertOffset, limit, valid );
 267       gxv_odtect_add_range( table + vertOffset, valid->subtable_length,
 268                             "vertJustData", odtect );
 269     }
 270
 271     gxv_odtect_validate( odtect, valid );
 272
 273     FT_TRACE4(( "\n" ));
 274   }
 275
 276
 277 /* END */