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/src/freetype/src/gxvalid/gxvmorx2.c

https://bitbucket.org/cabalistic/ogredeps/
C | 327 lines | 222 code | 69 blank | 36 comment | 16 complexity | 743c6d0aa028ee72da62934b08517bce MD5 | raw file
  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 */