1 /*
2 * Copyright © 2007,2008,2009 Red Hat, Inc.
3 * Copyright © 2012 Google, Inc.
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29 #ifndef HB_OPEN_FILE_PRIVATE_HH
30 #define HB_OPEN_FILE_PRIVATE_HH
31
32 #include "hb-open-type-private.hh"
33 #include "hb-ot-head-table.hh"
34
35
36 namespace OT {
37
38
39 /*
40 *
41 * The OpenType Font File
42 *
43 */
44
45
46 /*
47 * Organization of an OpenType Font
48 */
49
50 struct OpenTypeFontFile;
51 struct OffsetTable;
52 struct TTCHeader;
53
54
55 typedef struct TableRecord
56 {
57 int cmp (Tag t) const
58 { return -t.cmp (tag); }
59
60 static int cmp (const void *pa, const void *pb)
61 {
62 const TableRecord *a = (const TableRecord *) pa;
63 const TableRecord *b = (const TableRecord *) pb;
64 return b->cmp (a->tag);
65 }
66
67 inline bool sanitize (hb_sanitize_context_t *c) const
68 {
69 TRACE_SANITIZE (this);
70 return_trace (c->check_struct (this));
71 }
72
73 Tag tag; /* 4-byte identifier. */
74 CheckSum checkSum; /* CheckSum for this table. */
75 Offset32 offset; /* Offset from beginning of TrueType font
76 * file. */
77 HBUINT32 length; /* Length of this table. */
78 public:
79 DEFINE_SIZE_STATIC (16);
80 } OpenTypeTable;
81
82 typedef struct OffsetTable
83 {
84 friend struct OpenTypeFontFile;
85
86 inline unsigned int get_table_count (void) const
87 { return tables.len; }
88 inline const TableRecord& get_table (unsigned int i) const
89 {
90 return tables[i];
91 }
92 inline unsigned int get_table_tags (unsigned int start_offset,
93 unsigned int *table_count, /* IN/OUT */
94 hb_tag_t *table_tags /* OUT */) const
95 {
96 if (table_count)
97 {
98 if (start_offset >= tables.len)
99 *table_count = 0;
100 else
101 *table_count = MIN<unsigned int> (*table_count, tables.len - start_offset);
102
103 const TableRecord *sub_tables = tables.arrayZ + start_offset;
104 unsigned int count = *table_count;
105 for (unsigned int i = 0; i < count; i++)
106 table_tags[i] = sub_tables[i].tag;
107 }
108 return tables.len;
109 }
110 inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
111 {
112 Tag t;
113 t.set (tag);
114 /* Linear-search for small tables to work around fonts with unsorted
115 * table list. */
116 int i = tables.len < 64 ? tables.lsearch (t) : tables.bsearch (t);
117 if (table_index)
118 *table_index = i == -1 ? Index::NOT_FOUND_INDEX : (unsigned int) i;
119 return i != -1;
120 }
121 inline const TableRecord& get_table_by_tag (hb_tag_t tag) const
122 {
123 unsigned int table_index;
124 find_table_index (tag, &table_index);
125 return get_table (table_index);
126 }
127
128 public:
129
130 inline bool serialize (hb_serialize_context_t *c,
131 hb_tag_t sfnt_tag,
132 Supplier<hb_tag_t> &tags,
133 Supplier<hb_blob_t *> &blobs,
134 unsigned int table_count)
135 {
136 TRACE_SERIALIZE (this);
137 /* Alloc 12 for the OTHeader. */
138 if (unlikely (!c->extend_min (*this))) return_trace (false);
139 /* Write sfntVersion (bytes 0..3). */
140 sfnt_version.set (sfnt_tag);
141 /* Take space for numTables, searchRange, entrySelector, RangeShift
142 * and the TableRecords themselves. */
143 if (unlikely (!tables.serialize (c, table_count))) return_trace (false);
144
145 const char *dir_end = (const char *) c->head;
146 HBUINT32 *checksum_adjustment = nullptr;
147
148 /* Write OffsetTables, alloc for and write actual table blobs. */
149 for (unsigned int i = 0; i < table_count; i++)
150 {
151 TableRecord &rec = tables.arrayZ[i];
152 hb_blob_t *blob = blobs[i];
153 rec.tag.set (tags[i]);
154 rec.length.set (hb_blob_get_length (blob));
155 rec.offset.serialize (c, this);
156
157 /* Allocate room for the table and copy it. */
158 char *start = (char *) c->allocate_size<void> (rec.length);
159 if (unlikely (!start)) {return false;}
160
161 memcpy (start, hb_blob_get_data (blob, nullptr), rec.length);
162
163 /* 4-byte allignment. */
164 if (rec.length % 4)
165 c->allocate_size<void> (4 - rec.length % 4);
166 const char *end = (const char *) c->head;
167
168 if (tags[i] == HB_OT_TAG_head && end - start >= head::static_size)
169 {
170 head *h = (head *) start;
171 checksum_adjustment = &h->checkSumAdjustment;
172 checksum_adjustment->set (0);
173 }
174
175 rec.checkSum.set_for_data (start, end - start);
176 }
177 tags += table_count;
178 blobs += table_count;
179
180 tables.qsort ();
181
182 if (checksum_adjustment)
183 {
184 CheckSum checksum;
185
186 /* The following line is a slower version of the following block. */
187 //checksum.set_for_data (this, (const char *) c->head - (const char *) this);
188 checksum.set_for_data (this, dir_end - (const char *) this);
189 for (unsigned int i = 0; i < table_count; i++)
190 {
191 TableRecord &rec = tables.arrayZ[i];
192 checksum.set (checksum + rec.checkSum);
193 }
194
195 checksum_adjustment->set (0xB1B0AFBAu - checksum);
196 }
197
198 return_trace (true);
199 }
200
201 inline bool sanitize (hb_sanitize_context_t *c) const
202 {
203 TRACE_SANITIZE (this);
204 return_trace (c->check_struct (this) && tables.sanitize (c));
205 }
206
207 protected:
208 Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
209 BinSearchArrayOf<TableRecord>
210 tables;
211 public:
212 DEFINE_SIZE_ARRAY (12, tables);
213 } OpenTypeFontFace;
214
215
216 /*
217 * TrueType Collections
218 */
219
220 struct TTCHeaderVersion1
221 {
222 friend struct TTCHeader;
223
224 inline unsigned int get_face_count (void) const { return table.len; }
225 inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }
226
227 inline bool sanitize (hb_sanitize_context_t *c) const
228 {
229 TRACE_SANITIZE (this);
230 return_trace (table.sanitize (c, this));
231 }
232
233 protected:
234 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
235 FixedVersion<>version; /* Version of the TTC Header (1.0),
236 * 0x00010000u */
237 LArrayOf<LOffsetTo<OffsetTable> >
238 table; /* Array of offsets to the OffsetTable for each font
239 * from the beginning of the file */
240 public:
241 DEFINE_SIZE_ARRAY (12, table);
242 };
243
244 struct TTCHeader
245 {
246 friend struct OpenTypeFontFile;
247
248 private:
249
250 inline unsigned int get_face_count (void) const
251 {
252 switch (u.header.version.major) {
253 case 2: /* version 2 is compatible with version 1 */
254 case 1: return u.version1.get_face_count ();
255 default:return 0;
256 }
257 }
258 inline const OpenTypeFontFace& get_face (unsigned int i) const
259 {
260 switch (u.header.version.major) {
261 case 2: /* version 2 is compatible with version 1 */
262 case 1: return u.version1.get_face (i);
263 default:return Null(OpenTypeFontFace);
264 }
265 }
266
267 inline bool sanitize (hb_sanitize_context_t *c) const
268 {
269 TRACE_SANITIZE (this);
270 if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
271 switch (u.header.version.major) {
272 case 2: /* version 2 is compatible with version 1 */
273 case 1: return_trace (u.version1.sanitize (c));
274 default:return_trace (true);
275 }
276 }
277
278 protected:
279 union {
280 struct {
281 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
282 FixedVersion<>version; /* Version of the TTC Header (1.0 or 2.0),
283 * 0x00010000u or 0x00020000u */
284 } header;
285 TTCHeaderVersion1 version1;
286 } u;
287 };
288
289 /*
290 * Mac Resource Fork
291 */
292
293 struct ResourceRefItem
294 {
295 inline bool sanitize (hb_sanitize_context_t *c) const
296 {
297 TRACE_SANITIZE (this);
298 // actual data sanitization is done on ResourceForkHeader sanitizer
299 return_trace (likely (c->check_struct (this)));
300 }
301
302 HBINT16 id; /* Resource ID, is really should be signed? */
303 HBINT16 nameOffset; /* Offset from beginning of resource name list
304 * to resource name, minus means there is no */
305 HBUINT8 attr; /* Resource attributes */
306 HBUINT24 dataOffset; /* Offset from beginning of resource data to
307 * data for this resource */
308 HBUINT32 reserved; /* Reserved for handle to resource */
309 public:
310 DEFINE_SIZE_STATIC (12);
311 };
312
313 struct ResourceTypeItem
314 {
315 inline bool sanitize (hb_sanitize_context_t *c) const
316 {
317 TRACE_SANITIZE (this);
318 // RefList sanitization is done on ResourceMap sanitizer
319 return_trace (likely (c->check_struct (this)));
320 }
321
322 inline unsigned int get_resource_count () const
323 {
324 return numRes + 1;
325 }
326
327 inline bool is_sfnt () const
328 {
329 return type == HB_TAG ('s','f','n','t');
330 }
331
332 inline const ResourceRefItem& get_ref_item (const void *base,
333 unsigned int i) const
334 {
335 return (base+refList)[i];
336 }
337
338 protected:
339 Tag type; /* Resource type */
340 HBUINT16 numRes; /* Number of resource this type in map minus 1 */
341 OffsetTo<UnsizedArrayOf<ResourceRefItem> >
342 refList; /* Offset from beginning of resource type list
343 * to reference list for this type */
344 public:
345 DEFINE_SIZE_STATIC (8);
346 };
347
348 struct ResourceMap
349 {
350 inline bool sanitize (hb_sanitize_context_t *c) const
351 {
352 TRACE_SANITIZE (this);
353 if (unlikely (!c->check_struct (this)))
354 return_trace (false);
355 for (unsigned int i = 0; i < get_types_count (); ++i)
356 {
357 const ResourceTypeItem& type = get_type (i);
358 if (unlikely (!type.sanitize (c)))
359 return_trace (false);
360 for (unsigned int j = 0; j < type.get_resource_count (); ++j)
361 if (unlikely (!get_ref_item (type, j).sanitize (c)))
362 return_trace (false);
363 }
364 return_trace (true);
365 }
366
367 inline const ResourceTypeItem& get_type (unsigned int i) const
368 {
369 // Why offset from the second byte of the object? I'm not sure
370 return ((&reserved[2])+typeList)[i];
371 }
372
373 inline unsigned int get_types_count () const
374 {
375 return nTypes + 1;
376 }
377
378 inline const ResourceRefItem &get_ref_item (const ResourceTypeItem &type,
379 unsigned int i) const
380 {
381 return type.get_ref_item (&(this+typeList), i);
382 }
383
384 inline const PString& get_name (const ResourceRefItem &item,
385 unsigned int i) const
386 {
387 if (item.nameOffset == -1)
388 return Null (PString);
389
390 return StructAtOffset<PString> (this, nameList + item.nameOffset);
391 }
392
393 protected:
394 HBUINT8 reserved[16]; /* Reserved for copy of resource header */
395 LOffsetTo<ResourceMap>
396 reserved1; /* Reserved for handle to next resource map */
397 HBUINT16 reserved2; /* Reserved for file reference number */
398 HBUINT16 attr; /* Resource fork attribute */
399 OffsetTo<UnsizedArrayOf<ResourceTypeItem> >
400 typeList; /* Offset from beginning of map to
401 * resource type list */
402 HBUINT16 nameList; /* Offset from beginning of map to
403 * resource name list */
404 HBUINT16 nTypes; /* Number of types in the map minus 1 */
405 public:
406 DEFINE_SIZE_STATIC (30);
407 };
408
409 struct ResourceForkHeader
410 {
411 inline unsigned int get_face_count () const
412 {
413 const ResourceMap &resource_map = this+map;
414 for (unsigned int i = 0; i < resource_map.get_types_count (); ++i)
415 {
416 const ResourceTypeItem& type = resource_map.get_type (i);
417 if (type.is_sfnt ())
418 return type.get_resource_count ();
419 }
420 return 0;
421 }
422
423 inline const LArrayOf<HBUINT8>& get_data (const ResourceTypeItem& type,
424 unsigned int idx) const
425 {
426 const ResourceMap &resource_map = this+map;
427 unsigned int offset = dataOffset;
428 offset += resource_map.get_ref_item (type, idx).dataOffset;
429 return StructAtOffset<LArrayOf<HBUINT8> > (this, offset);
430 }
431
432 inline const OpenTypeFontFace& get_face (unsigned int idx) const
433 {
434 const ResourceMap &resource_map = this+map;
435 for (unsigned int i = 0; i < resource_map.get_types_count (); ++i)
436 {
437 const ResourceTypeItem& type = resource_map.get_type (i);
438 if (type.is_sfnt () && idx < type.get_resource_count ())
439 return (OpenTypeFontFace&) get_data (type, idx).arrayZ;
440 }
441 return Null (OpenTypeFontFace);
442 }
443
444 inline bool sanitize (hb_sanitize_context_t *c) const
445 {
446 TRACE_SANITIZE (this);
447 if (unlikely (!c->check_struct (this)))
448 return_trace (false);
449
450 const ResourceMap &resource_map = this+map;
451 if (unlikely (!resource_map.sanitize (c)))
452 return_trace (false);
453
454 for (unsigned int i = 0; i < resource_map.get_types_count (); ++i)
455 {
456 const ResourceTypeItem& type = resource_map.get_type (i);
457 for (unsigned int j = 0; j < type.get_resource_count (); ++j)
458 {
459 const LArrayOf<HBUINT8>& data = get_data (type, j);
460 if (unlikely (!(data.sanitize (c) &&
461 ((OpenTypeFontFace&) data.arrayZ).sanitize (c))))
462 return_trace (false);
463 }
464 }
465
466 return_trace (true);
467 }
468
469 protected:
470 HBUINT32 dataOffset; /* Offset from beginning of resource fork
471 * to resource data */
472 LOffsetTo<ResourceMap>
473 map; /* Offset from beginning of resource fork
474 * to resource map */
475 HBUINT32 dataLen; /* Length of resource data */
476 HBUINT32 mapLen; /* Length of resource map */
477 public:
478 DEFINE_SIZE_STATIC (16);
479 };
480
481 /*
482 * OpenType Font File
483 */
484
485 struct OpenTypeFontFile
486 {
487 static const hb_tag_t tableTag = HB_TAG ('_','_','_','_'); /* Sanitizer needs this. */
488
489 enum {
490 CFFTag = HB_TAG ('O','T','T','O'), /* OpenType with Postscript outlines */
491 TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ), /* OpenType with TrueType outlines */
492 TTCTag = HB_TAG ('t','t','c','f'), /* TrueType Collection */
493 DFontTag = HB_TAG ( 0 , 0 , 1 , 0 ), /* DFont Mac Resource Fork */
494 TrueTag = HB_TAG ('t','r','u','e'), /* Obsolete Apple TrueType */
495 Typ1Tag = HB_TAG ('t','y','p','1') /* Obsolete Apple Type1 font in SFNT container */
496 };
497
498 inline hb_tag_t get_tag (void) const { return u.tag; }
499
500 inline unsigned int get_face_count (void) const
501 {
502 switch (u.tag) {
503 case CFFTag: /* All the non-collection tags */
504 case TrueTag:
505 case Typ1Tag:
506 case TrueTypeTag: return 1;
507 case TTCTag: return u.ttcHeader.get_face_count ();
508 // case DFontTag: return u.rfHeader.get_face_count ();
509 default: return 0;
510 }
511 }
512 inline const OpenTypeFontFace& get_face (unsigned int i) const
513 {
514 switch (u.tag) {
515 /* Note: for non-collection SFNT data we ignore index. This is because
516 * Apple dfont container is a container of SFNT's. So each SFNT is a
517 * non-TTC, but the index is more than zero. */
518 case CFFTag: /* All the non-collection tags */
519 case TrueTag:
520 case Typ1Tag:
521 case TrueTypeTag: return u.fontFace;
522 case TTCTag: return u.ttcHeader.get_face (i);
523 // case DFontTag: return u.rfHeader.get_face (i);
524 default: return Null(OpenTypeFontFace);
525 }
526 }
527
528 inline bool serialize_single (hb_serialize_context_t *c,
529 hb_tag_t sfnt_tag,
530 Supplier<hb_tag_t> &tags,
531 Supplier<hb_blob_t *> &blobs,
532 unsigned int table_count)
533 {
534 TRACE_SERIALIZE (this);
535 assert (sfnt_tag != TTCTag);
536 if (unlikely (!c->extend_min (*this))) return_trace (false);
537 return_trace (u.fontFace.serialize (c, sfnt_tag, tags, blobs, table_count));
538 }
539
540 inline bool sanitize (hb_sanitize_context_t *c) const
541 {
542 TRACE_SANITIZE (this);
543 if (unlikely (!u.tag.sanitize (c))) return_trace (false);
544 switch (u.tag) {
545 case CFFTag: /* All the non-collection tags */
546 case TrueTag:
547 case Typ1Tag:
548 case TrueTypeTag: return_trace (u.fontFace.sanitize (c));
549 case TTCTag: return_trace (u.ttcHeader.sanitize (c));
550 // case DFontTag: return_trace (u.rfHeader.sanitize (c));
551 default: return_trace (true);
552 }
553 }
554
555 protected:
556 union {
557 Tag tag; /* 4-byte identifier. */
558 OpenTypeFontFace fontFace;
559 TTCHeader ttcHeader;
560 ResourceForkHeader rfHeader;
561 } u;
562 public:
563 DEFINE_SIZE_UNION (4, tag);
564 };
565
566
567 } /* namespace OT */
568
569
570 #endif /* HB_OPEN_FILE_PRIVATE_HH */