src/gxvalid/gxvmorx2.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  gxvmorx2.c                                                             */
   4 /*                                                                         */
   5 /*    TrueTypeGX/AAT morx table validation                                 */
   6 /*    body for type2 (Ligature Substitution) subtable.                     */
   7 /*                                                                         */
   8 /*  Copyright 2005 by 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   typedef struct  GXV_morx_subtable_type2_StateOptRec_
  42   {
  43     FT_ULong  ligActionTable;
  44     FT_ULong  componentTable;
  45     FT_ULong  ligatureTable;
  46     FT_ULong  ligActionTable_length;
  47     FT_ULong  componentTable_length;
  48     FT_ULong  ligatureTable_length;
  49
  50   }  GXV_morx_subtable_type2_StateOptRec,
  51     *GXV_morx_subtable_type2_StateOptRecData;
  52
  53
  54 #define GXV_MORX_SUBTABLE_TYPE2_HEADER_SIZE \
  55           ( GXV_XSTATETABLE_HEADER_SIZE + 4 + 4 + 4 )
  56
  57
  58   static void
  59   gxv_morx_subtable_type2_opttable_load( FT_Bytes       table,
  60                                          FT_Bytes       limit,
  61                                          GXV_Validator  valid )
  62   {
  63     FT_Bytes  p = table;
  64
  65     GXV_morx_subtable_type2_StateOptRecData  optdata =
  66       (GXV_morx_subtable_type2_StateOptRecData)valid->xstatetable.optdata;
  67
  68
  69     GXV_LIMIT_CHECK( 4 + 4 + 4 );
  70     optdata->ligActionTable = FT_NEXT_ULONG( p );
  71     optdata->componentTable = FT_NEXT_ULONG( p );
  72     optdata->ligatureTable  = FT_NEXT_ULONG( p );
  73
  74     GXV_TRACE(( "offset to ligActionTable=0x%08x\n",
  75                 optdata->ligActionTable ));
  76     GXV_TRACE(( "offset to componentTable=0x%08x\n",
  77                 optdata->componentTable ));
  78     GXV_TRACE(( "offset to ligatureTable=0x%08x\n",
  79                 optdata->ligatureTable ));
  80   }
  81
  82
  83   static void
  84   gxv_morx_subtable_type2_subtable_setup( FT_ULong       table_size,
  85                                           FT_ULong       classTable,
  86                                           FT_ULong       stateArray,
  87                                           FT_ULong       entryTable,
  88                                           FT_ULong*      classTable_length_p,
  89                                           FT_ULong*      stateArray_length_p,
  90                                           FT_ULong*      entryTable_length_p,
  91                                           GXV_Validator  valid )
  92   {
  93     FT_ULong   o[6];
  94     FT_ULong*  l[6];
  95     FT_ULong   buff[7];
  96
  97     GXV_morx_subtable_type2_StateOptRecData  optdata =
  98       (GXV_morx_subtable_type2_StateOptRecData)valid->xstatetable.optdata;
  99
 100
 101     GXV_NAME_ENTER( "subtable boundaries setup" );
 102
 103     o[0] = classTable;
 104     o[1] = stateArray;
 105     o[2] = entryTable;
 106     o[3] = optdata->ligActionTable;
 107     o[4] = optdata->componentTable;
 108     o[5] = optdata->ligatureTable;
 109     l[0] = classTable_length_p;
 110     l[1] = stateArray_length_p;
 111     l[2] = entryTable_length_p;
 112     l[3] = &(optdata->ligActionTable_length);
 113     l[4] = &(optdata->componentTable_length);
 114     l[5] = &(optdata->ligatureTable_length);
 115
 116     gxv_set_length_by_ulong_offset( o, l, buff, 6, table_size, valid );
 117
 118     GXV_TRACE(( "classTable: offset=0x%08x length=0x%08x\n",
 119                 classTable, *classTable_length_p ));
 120     GXV_TRACE(( "stateArray: offset=0x%08x length=0x%08x\n",
 121                 stateArray, *stateArray_length_p ));
 122     GXV_TRACE(( "entryTable: offset=0x%08x length=0x%08x\n",
 123                 entryTable, *entryTable_length_p ));
 124     GXV_TRACE(( "ligActionTable: offset=0x%08x length=0x%08x\n",
 125                 optdata->ligActionTable,
 126                 optdata->ligActionTable_length ));
 127     GXV_TRACE(( "componentTable: offset=0x%08x length=0x%08x\n",
 128                 optdata->componentTable,
 129                 optdata->componentTable_length ));
 130     GXV_TRACE(( "ligatureTable:  offset=0x%08x length=0x%08x\n",
 131                 optdata->ligatureTable,
 132                 optdata->ligatureTable_length ));
 133
 134     GXV_EXIT;
 135   }
 136
 137
 138 #define GXV_MORX_LIGACTION_ENTRY_SIZE  4
 139
 140
 141   static void
 142   gxv_morx_subtable_type2_ligActionIndex_validate(
 143     FT_Bytes       table,
 144     FT_UShort      ligActionIndex,
 145     GXV_Validator  valid )
 146   {
 147     /* access ligActionTable */
 148     GXV_morx_subtable_type2_StateOptRecData optdata =
 149       (GXV_morx_subtable_type2_StateOptRecData)valid->xstatetable.optdata;
 150
 151     FT_Bytes lat_base  = table + optdata->ligActionTable;
 152     FT_Bytes p         = lat_base +
 153                          ligActionIndex * GXV_MORX_LIGACTION_ENTRY_SIZE;
 154     FT_Bytes lat_limit = lat_base + optdata->ligActionTable;
 155
 156
 157     if ( p < lat_base )
 158     {
 159       GXV_TRACE(( "p < lat_base (%d byte rewind)\n", lat_base - p ));
 160       FT_INVALID_OFFSET;
 161     }
 162     else if ( lat_limit < p )
 163     {
 164       GXV_TRACE(( "lat_limit < p (%d byte overrun)\n", p - lat_limit ));
 165       FT_INVALID_OFFSET;
 166     }
 167
 168     {
 169       /* validate entry in ligActionTable */
 170       FT_ULong   lig_action;
 171 #ifdef GXV_LOAD_UNUSED_VARS
 172       FT_UShort  last;
 173       FT_UShort  store;
 174 #endif
 175       FT_ULong   offset;
 176       FT_Long    gid_limit;
 177
 178
 179       lig_action = FT_NEXT_ULONG( p );
 180 #ifdef GXV_LOAD_UNUSED_VARS
 181       last       = (FT_UShort)( ( lig_action >> 31 ) & 1 );
 182       store      = (FT_UShort)( ( lig_action >> 30 ) & 1 );
 183 #endif
 184
 185       offset = lig_action & 0x3FFFFFFFUL;
 186
 187       /* this offset is 30-bit signed value to add to GID */
 188       /* it is different from the location offset in mort */
 189       if ( ( offset & 0x3FFF0000UL ) == 0x3FFF0000UL )
 190       { /* negative offset */
 191         gid_limit = valid->face->num_glyphs - ( offset & 0x0000FFFFUL );
 192         if ( gid_limit > 0 )
 193           return;
 194
 195         GXV_TRACE(( "ligature action table includes"
 196                     " too negative offset moving all GID"
 197                     " below defined range: 0x%04x\n",
 198                     offset & 0xFFFFU ));
 199         GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 200       }
 201       else if ( ( offset & 0x3FFF0000UL ) == 0x0000000UL )
 202       { /* positive offset */
 203         if ( (FT_Long)offset < valid->face->num_glyphs )
 204           return;
 205
 206         GXV_TRACE(( "ligature action table includes"
 207                     " too large offset moving all GID"
 208                     " over defined range: 0x%04x\n",
 209                     offset & 0xFFFFU ));
 210         GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 211       }
 212
 213       GXV_TRACE(( "ligature action table includes"
 214                   " invalid offset to add to 16-bit GID:"
 215                   " 0x%08x\n", offset ));
 216       GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET );
 217     }
 218   }
 219
 220
 221   static void
 222   gxv_morx_subtable_type2_entry_validate(
 223     FT_UShort                       state,
 224     FT_UShort                       flags,
 225     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
 226     FT_Bytes                        table,
 227     FT_Bytes                        limit,
 228     GXV_Validator                   valid )
 229   {
 230 #ifdef GXV_LOAD_UNUSED_VARS
 231     FT_UShort  setComponent;
 232     FT_UShort  dontAdvance;
 233     FT_UShort  performAction;
 234 #endif
 235     FT_UShort  reserved;
 236     FT_UShort  ligActionIndex;
 237
 238     FT_UNUSED( state );
 239     FT_UNUSED( limit );
 240
 241
 242 #ifdef GXV_LOAD_UNUSED_VARS
 243     setComponent   = (FT_UShort)( ( flags >> 15 ) & 1 );
 244     dontAdvance    = (FT_UShort)( ( flags >> 14 ) & 1 );
 245     performAction  = (FT_UShort)( ( flags >> 13 ) & 1 );
 246 #endif
 247
 248     reserved       = (FT_UShort)( flags & 0x1FFF );
 249     ligActionIndex = glyphOffset_p->u;
 250
 251     if ( reserved > 0 )
 252       GXV_TRACE(( "  reserved 14bit is non-zero\n" ));
 253
 254     if ( 0 < ligActionIndex )
 255       gxv_morx_subtable_type2_ligActionIndex_validate(
 256         table, ligActionIndex, valid );
 257   }
 258
 259
 260   static void
 261   gxv_morx_subtable_type2_ligatureTable_validate( FT_Bytes       table,
 262                                                   GXV_Validator  valid )
 263   {
 264     GXV_morx_subtable_type2_StateOptRecData  optdata =
 265       (GXV_morx_subtable_type2_StateOptRecData)valid->xstatetable.optdata;
 266
 267     FT_Bytes p     = table + optdata->ligatureTable;
 268     FT_Bytes limit = table + optdata->ligatureTable
 269                            + optdata->ligatureTable_length;
 270
 271
 272     GXV_NAME_ENTER( "morx chain subtable type2 - substitutionTable" );
 273
 274     if ( 0 != optdata->ligatureTable )
 275     {
 276       /* Apple does not give specification of ligatureTable format */
 277       while ( p < limit )
 278       {
 279         FT_UShort  lig_gid;
 280
 281
 282         GXV_LIMIT_CHECK( 2 );
 283         lig_gid = FT_NEXT_USHORT( p );
 284         if ( lig_gid < valid->face->num_glyphs )
 285           GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
 286       }
 287     }
 288
 289     GXV_EXIT;
 290   }
 291
 292
 293   FT_LOCAL_DEF( void )
 294   gxv_morx_subtable_type2_validate( FT_Bytes       table,
 295                                     FT_Bytes       limit,
 296                                     GXV_Validator  valid )
 297   {
 298     FT_Bytes  p = table;
 299
 300     GXV_morx_subtable_type2_StateOptRec  lig_rec;
 301
 302
 303     GXV_NAME_ENTER( "morx chain subtable type2 (Ligature Substitution)" );
 304
 305     GXV_LIMIT_CHECK( GXV_MORX_SUBTABLE_TYPE2_HEADER_SIZE );
 306
 307     valid->xstatetable.optdata =
 308       &lig_rec;
 309     valid->xstatetable.optdata_load_func =
 310       gxv_morx_subtable_type2_opttable_load;
 311     valid->xstatetable.subtable_setup_func =
 312       gxv_morx_subtable_type2_subtable_setup;
 313     valid->xstatetable.entry_glyphoffset_fmt =
 314       GXV_GLYPHOFFSET_USHORT;
 315     valid->xstatetable.entry_validate_func =
 316       gxv_morx_subtable_type2_entry_validate;
 317
 318     gxv_XStateTable_validate( p, limit, valid );
 319
 320     p += valid->subtable_length;
 321     gxv_morx_subtable_type2_ligatureTable_validate( table, valid );
 322
 323     GXV_EXIT;
 324   }
 325
 326
 327 /* END */