/src/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#ifdef GXV_LOAD_UNUSED_VARS
 72      FT_ULong  subFeatureFlags;
 73#endif
 74      FT_ULong  type;
 75      FT_ULong  rest;
 76
 77
 78      GXV_LIMIT_CHECK( 4 + 4 + 4 );
 79      length          = FT_NEXT_ULONG( p );
 80      coverage        = FT_NEXT_ULONG( p );
 81#ifdef GXV_LOAD_UNUSED_VARS
 82      subFeatureFlags = FT_NEXT_ULONG( p );
 83#else
 84      p += 4;
 85#endif
 86
 87      GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
 88                  i + 1, nSubtables, length ));
 89
 90      type = coverage & 0x0007;
 91      rest = length - ( 4 + 4 + 4 );
 92      GXV_LIMIT_CHECK( rest );
 93
 94      /* morx coverage consists of mort_coverage & 16bit padding */
 95      gxv_mort_coverage_validate( (FT_UShort)( ( coverage >> 16 ) | coverage ),
 96                                  valid );
 97      if ( type > 5 )
 98        FT_INVALID_FORMAT;
 99
100      func = fmt_funcs_table[type];
101      if ( func == NULL )
102        GXV_TRACE(( "morx type %d is reserved\n", type ));
103
104      func( p, p + rest, valid );
105
106      /* TODO: subFeatureFlags should be unique in a table? */
107      p += rest;
108    }
109
110    valid->subtable_length = p - table;
111
112    GXV_EXIT;
113  }
114
115
116  static void
117  gxv_morx_chain_validate( FT_Bytes       table,
118                           FT_Bytes       limit,
119                           GXV_Validator  valid )
120  {
121    FT_Bytes  p = table;
122#ifdef GXV_LOAD_UNUSED_VARS
123    FT_ULong  defaultFlags;
124#endif
125    FT_ULong  chainLength;
126    FT_ULong  nFeatureFlags;
127    FT_ULong  nSubtables;
128
129
130    GXV_NAME_ENTER( "morx chain header" );
131
132    GXV_LIMIT_CHECK( 4 + 4 + 4 + 4 );
133#ifdef GXV_LOAD_UNUSED_VARS
134    defaultFlags  = FT_NEXT_ULONG( p );
135#else
136    p += 4;
137#endif
138    chainLength   = FT_NEXT_ULONG( p );
139    nFeatureFlags = FT_NEXT_ULONG( p );
140    nSubtables    = FT_NEXT_ULONG( p );
141
142    /* feature-array of morx is same with that of mort */
143    gxv_mort_featurearray_validate( p, limit, nFeatureFlags, valid );
144    p += valid->subtable_length;
145
146    if ( nSubtables >= 0x10000L )
147      FT_INVALID_DATA;
148
149    gxv_morx_subtables_validate( p, table + chainLength,
150                                 (FT_UShort)nSubtables, valid );
151
152    valid->subtable_length = chainLength;
153
154    /* TODO: defaultFlags should be compared with the flags in tables */
155
156    GXV_EXIT;
157  }
158
159
160  FT_LOCAL_DEF( void )
161  gxv_morx_validate( FT_Bytes      table,
162                     FT_Face       face,
163                     FT_Validator  ftvalid )
164  {
165    GXV_ValidatorRec  validrec;
166    GXV_Validator     valid = &validrec;
167    FT_Bytes          p     = table;
168    FT_Bytes          limit = 0;
169    FT_ULong          version;
170    FT_ULong          nChains;
171    FT_ULong          i;
172
173
174    valid->root = ftvalid;
175    valid->face = face;
176
177    FT_TRACE3(( "validating `morx' table\n" ));
178    GXV_INIT;
179
180    GXV_LIMIT_CHECK( 4 + 4 );
181    version = FT_NEXT_ULONG( p );
182    nChains = FT_NEXT_ULONG( p );
183
184    if ( version != 0x00020000UL )
185      FT_INVALID_FORMAT;
186
187    for ( i = 0; i < nChains; i++ )
188    {
189      GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
190      GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
191      gxv_morx_chain_validate( p, limit, valid );
192      p += valid->subtable_length;
193    }
194
195    FT_TRACE4(( "\n" ));
196  }
197
198
199/* END */