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

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmorx.c                                                              */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT morx table validation (body).                         */
   6 /*                                                                         */
   7 /*  Copyright 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 "gxvmorx.h"
  28
  29
  30   /*************************************************************************/
  31   /*                                                                       */
  32   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  33   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  34   /* messages during execution.                                            */
  35   /*                                                                       */
  36 #undef  FT_COMPONENT
  37 #define FT_COMPONENT  trace_gxvmorx
  38
  39
  40   static void
  41   gxv_morx_subtables_validate( FT_Bytes       table,
  42                                FT_Bytes       limit,
  43                                FT_UShort      nSubtables,
  44                                GXV_Validator  valid )
  45   {
  46     FT_Bytes  p = table;
  47
  48     GXV_Validate_Func fmt_funcs_table[] =
  49     {
  50       gxv_morx_subtable_type0_validate, /* 0 */
  51       gxv_morx_subtable_type1_validate, /* 1 */
  52       gxv_morx_subtable_type2_validate, /* 2 */
  53       NULL,                             /* 3 */
  54       gxv_morx_subtable_type4_validate, /* 4 */
  55       gxv_morx_subtable_type5_validate, /* 5 */
  56
  57     };
  58
  59     GXV_Validate_Func  func;
  60
  61     FT_UShort  i;
  62
  63
  64     GXV_NAME_ENTER( "subtables in a chain" );
  65
  66     for ( i = 0; i < nSubtables; i++ )
  67     {
  68       FT_ULong  length;
  69       FT_ULong  coverage;
  70       FT_ULong  subFeatureFlags;
  71       FT_UInt   type;
  72       FT_UInt   rest;
  73
  74
  75       GXV_LIMIT_CHECK( 4 + 4 + 4 );
  76       length          = FT_NEXT_ULONG( p );
  77       coverage        = FT_NEXT_ULONG( p );
  78       subFeatureFlags = FT_NEXT_ULONG( p );
  79
  80       GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
  81                   i + 1, nSubtables, length ));
  82
  83       type = coverage & 0x0007;
  84       rest = length - ( 4 + 4 + 4 );
  85       GXV_LIMIT_CHECK( rest );
  86
  87       /* morx coverage consists of mort_coverage & 16bit padding */
  88       gxv_mort_coverage_validate( (FT_UShort)( ( coverage >> 16 ) | coverage ),
  89                                   valid );
  90       if ( type > 5 )
  91         FT_INVALID_FORMAT;
  92
  93       func = fmt_funcs_table[type];
  94       if ( func == NULL )
  95         GXV_TRACE(( "morx type %d is reserved\n", type ));
  96
  97       func( p, p + rest, valid );
  98
  99       p += rest;
 100     }
 101
 102     valid->subtable_length = p - table;
 103
 104     GXV_EXIT;
 105   }
 106
 107
 108   static void
 109   gxv_morx_chain_validate( FT_Bytes       table,
 110                            FT_Bytes       limit,
 111                            GXV_Validator  valid )
 112   {
 113     FT_Bytes  p = table;
 114     FT_ULong  defaultFlags;
 115     FT_ULong  chainLength;
 116     FT_ULong  nFeatureFlags;
 117     FT_ULong  nSubtables;
 118
 119
 120     GXV_NAME_ENTER( "morx chain header" );
 121
 122     GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
 123     defaultFlags  = FT_NEXT_ULONG( p );
 124     chainLength   = FT_NEXT_ULONG( p );
 125     nFeatureFlags = FT_NEXT_ULONG( p );
 126     nSubtables    = FT_NEXT_ULONG( p );
 127
 128     /* feature-array of morx is same with that of mort */
 129     gxv_mort_featurearray_validate( p, limit, nFeatureFlags, valid );
 130     p += valid->subtable_length;
 131
 132     if ( nSubtables >= 0x10000 )
 133       FT_INVALID_DATA;
 134
 135     gxv_morx_subtables_validate( p, table + chainLength,
 136                                  (FT_UShort)nSubtables, valid );
 137
 138     valid->subtable_length = chainLength;
 139
 140     GXV_EXIT;
 141   }
 142
 143
 144   FT_LOCAL_DEF( void )
 145   gxv_morx_validate( FT_Bytes      table,
 146                      FT_Face       face,
 147                      FT_Validator  ftvalid )
 148   {
 149     GXV_ValidatorRec  validrec;
 150     GXV_Validator     valid = &validrec;
 151     FT_Bytes          p     = table;
 152     FT_Bytes          limit = 0;
 153     FT_ULong          version;
 154     FT_ULong          nChains;
 155     FT_ULong          i;
 156
 157
 158     valid->root = ftvalid;
 159     valid->face = face;
 160
 161     FT_TRACE3(( "validating `morx' table\n" ));
 162     GXV_INIT;
 163
 164     GXV_LIMIT_CHECK( 4 + 4 );
 165     version = FT_NEXT_ULONG( p );
 166     nChains = FT_NEXT_ULONG( p );
 167
 168     if ( version != 0x00020000UL )
 169       FT_INVALID_FORMAT;
 170
 171     for ( i = 0; i < nChains; i++ )
 172     {
 173       GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
 174       GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
 175       gxv_morx_chain_validate( p, limit, valid );
 176       p += valid->subtable_length;
 177     }
 178
 179     FT_TRACE4(( "\n" ));
 180   }
 181
 182
 183 /* END */