lib/3rdparty/freetype/src/gxvalid/gxvmorx.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmorx.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT morx table validation (body).                         */
   6 /*                                                                         */
   7 /*  Copyright 2005, 2008 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 "gxvmorx.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_gxvmorx
  39
  40
  41   static void
  42   gxv_morx_subtables_validate( FT_Bytes       table,
  43                                FT_Bytes       limit,
  44                                FT_UShort      nSubtables,
  45                                GXV_Validator  valid )
  46   {
  47     FT_Bytes  p = table;
  48
  49     GXV_Validate_Func fmt_funcs_table[] =
  50     {
  51       gxv_morx_subtable_type0_validate, /* 0 */
  52       gxv_morx_subtable_type1_validate, /* 1 */
  53       gxv_morx_subtable_type2_validate, /* 2 */
  54       NULL,                             /* 3 */
  55       gxv_morx_subtable_type4_validate, /* 4 */
  56       gxv_morx_subtable_type5_validate, /* 5 */
  57
  58     };
  59
  60     GXV_Validate_Func  func;
  61
  62     FT_UShort  i;
  63
  64
  65     GXV_NAME_ENTER( "subtables in a chain" );
  66
  67     for ( i = 0; i < nSubtables; i++ )
  68     {
  69       FT_ULong  length;
  70       FT_ULong  coverage;
  71       FT_ULong  subFeatureFlags;
  72       FT_ULong  type;
  73       FT_ULong  rest;
  74
  75
  76       GXV_LIMIT_CHECK( 4 + 4 + 4 );
  77       length          = FT_NEXT_ULONG( p );
  78       coverage        = FT_NEXT_ULONG( p );
  79       subFeatureFlags = FT_NEXT_ULONG( p );
  80
  81       GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
  82                   i + 1, nSubtables, length ));
  83
  84       type = coverage & 0x0007;
  85       rest = length - ( 4 + 4 + 4 );
  86       GXV_LIMIT_CHECK( rest );
  87
  88       /* morx coverage consists of mort_coverage & 16bit padding */
  89       gxv_mort_coverage_validate( (FT_UShort)( ( coverage >> 16 ) | coverage ),
  90                                   valid );
  91       if ( type > 5 )
  92         FT_INVALID_FORMAT;
  93
  94       func = fmt_funcs_table[type];
  95       if ( func == NULL )
  96         GXV_TRACE(( "morx type %d is reserved\n", type ));
  97
  98       func( p, p + rest, valid );
  99
 100       p += rest;
 101     }
 102
 103     valid->subtable_length = p - table;
 104
 105     GXV_EXIT;
 106   }
 107
 108
 109   static void
 110   gxv_morx_chain_validate( FT_Bytes       table,
 111                            FT_Bytes       limit,
 112                            GXV_Validator  valid )
 113   {
 114     FT_Bytes  p = table;
 115     FT_ULong  defaultFlags;
 116     FT_ULong  chainLength;
 117     FT_ULong  nFeatureFlags;
 118     FT_ULong  nSubtables;
 119
 120
 121     GXV_NAME_ENTER( "morx chain header" );
 122
 123     GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
 124     defaultFlags  = FT_NEXT_ULONG( p );
 125     chainLength   = FT_NEXT_ULONG( p );
 126     nFeatureFlags = FT_NEXT_ULONG( p );
 127     nSubtables    = FT_NEXT_ULONG( p );
 128
 129     /* feature-array of morx is same with that of mort */
 130     gxv_mort_featurearray_validate( p, limit, nFeatureFlags, valid );
 131     p += valid->subtable_length;
 132
 133     if ( nSubtables >= 0x10000L )
 134       FT_INVALID_DATA;
 135
 136     gxv_morx_subtables_validate( p, table + chainLength,
 137                                  (FT_UShort)nSubtables, valid );
 138
 139     valid->subtable_length = chainLength;
 140
 141     GXV_EXIT;
 142   }
 143
 144
 145   FT_LOCAL_DEF( void )
 146   gxv_morx_validate( FT_Bytes      table,
 147                      FT_Face       face,
 148                      FT_Validator  ftvalid )
 149   {
 150     GXV_ValidatorRec  validrec;
 151     GXV_Validator     valid = &validrec;
 152     FT_Bytes          p     = table;
 153     FT_Bytes          limit = 0;
 154     FT_ULong          version;
 155     FT_ULong          nChains;
 156     FT_ULong          i;
 157
 158
 159     valid->root = ftvalid;
 160     valid->face = face;
 161
 162     FT_TRACE3(( "validating `morx' table\n" ));
 163     GXV_INIT;
 164
 165     GXV_LIMIT_CHECK( 4 + 4 );
 166     version = FT_NEXT_ULONG( p );
 167     nChains = FT_NEXT_ULONG( p );
 168
 169     if ( version != 0x00020000UL )
 170       FT_INVALID_FORMAT;
 171
 172     for ( i = 0; i < nChains; i++ )
 173     {
 174       GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
 175       GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
 176       gxv_morx_chain_validate( p, limit, valid );
 177       p += valid->subtable_length;
 178     }
 179
 180     FT_TRACE4(( "\n" ));
 181   }
 182
 183
 184 /* END */