1 /*
2 * Copyright © 2009 Red Hat, Inc.
3 * Copyright © 2018 Ebrahim Byagowi
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 */
27
28 /* http://www.oracle.com/technetwork/articles/servers-storage-dev/standardheaderfiles-453865.html */
29 #ifndef _POSIX_C_SOURCE
30 #define _POSIX_C_SOURCE 200809L
31 #endif
32
33 #include "hb-private.hh"
34 #include "hb-debug.hh"
35 #include "hb-blob-private.hh"
36
37 #ifdef HAVE_SYS_MMAN_H
38 #ifdef HAVE_UNISTD_H
39 #include <unistd.h>
40 #endif /* HAVE_UNISTD_H */
41 #include <sys/mman.h>
42 #endif /* HAVE_SYS_MMAN_H */
43
44 #include <stdio.h>
45 #include <errno.h>
46 #include <stdlib.h>
47
48
49 /**
50 * hb_blob_create: (skip)
51 * @data: Pointer to blob data.
52 * @length: Length of @data in bytes.
53 * @mode: Memory mode for @data.
54 * @user_data: Data parameter to pass to @destroy.
55 * @destroy: Callback to call when @data is not needed anymore.
56 *
57 * Creates a new "blob" object wrapping @data. The @mode parameter is used
58 * to negotiate ownership and lifecycle of @data.
59 *
60 * Return value: New blob, or the empty blob if something failed or if @length is
61 * zero. Destroy with hb_blob_destroy().
62 *
63 * Since: 0.9.2
64 **/
65 hb_blob_t *
66 hb_blob_create (const char *data,
67 unsigned int length,
68 hb_memory_mode_t mode,
69 void *user_data,
70 hb_destroy_func_t destroy)
71 {
72 hb_blob_t *blob;
73
74 if (!length ||
75 length >= 1u << 31 ||
76 !(blob = hb_object_create<hb_blob_t> ())) {
77 if (destroy)
78 destroy (user_data);
79 return hb_blob_get_empty ();
80 }
81
82 blob->data = data;
83 blob->length = length;
84 blob->mode = mode;
85
86 blob->user_data = user_data;
87 blob->destroy = destroy;
88
89 if (blob->mode == HB_MEMORY_MODE_DUPLICATE) {
90 blob->mode = HB_MEMORY_MODE_READONLY;
91 if (!blob->try_make_writable ()) {
92 hb_blob_destroy (blob);
93 return hb_blob_get_empty ();
94 }
95 }
96
97 return blob;
98 }
99
100 static void
101 _hb_blob_destroy (void *data)
102 {
103 hb_blob_destroy ((hb_blob_t *) data);
104 }
105
106 /**
107 * hb_blob_create_sub_blob:
108 * @parent: Parent blob.
109 * @offset: Start offset of sub-blob within @parent, in bytes.
110 * @length: Length of sub-blob.
111 *
112 * Returns a blob that represents a range of bytes in @parent. The new
113 * blob is always created with %HB_MEMORY_MODE_READONLY, meaning that it
114 * will never modify data in the parent blob. The parent data is not
115 * expected to be modified, and will result in undefined behavior if it
116 * is.
117 *
118 * Makes @parent immutable.
119 *
120 * Return value: New blob, or the empty blob if something failed or if
121 * @length is zero or @offset is beyond the end of @parent's data. Destroy
122 * with hb_blob_destroy().
123 *
124 * Since: 0.9.2
125 **/
126 hb_blob_t *
127 hb_blob_create_sub_blob (hb_blob_t *parent,
128 unsigned int offset,
129 unsigned int length)
130 {
131 hb_blob_t *blob;
132
133 if (!length || offset >= parent->length)
134 return hb_blob_get_empty ();
135
136 hb_blob_make_immutable (parent);
137
138 blob = hb_blob_create (parent->data + offset,
139 MIN (length, parent->length - offset),
140 HB_MEMORY_MODE_READONLY,
141 hb_blob_reference (parent),
142 _hb_blob_destroy);
143
144 return blob;
145 }
146
147 /**
148 * hb_blob_copy_writable_or_fail:
149 * @blob: A blob.
150 *
151 * Makes a writable copy of @blob.
152 *
153 * Return value: New blob, or nullptr if allocation failed.
154 *
155 * Since: 1.8.0
156 **/
157 hb_blob_t *
158 hb_blob_copy_writable_or_fail (hb_blob_t *blob)
159 {
160 blob = hb_blob_create (blob->data,
161 blob->length,
162 HB_MEMORY_MODE_DUPLICATE,
163 nullptr,
164 nullptr);
165
166 if (unlikely (blob == hb_blob_get_empty ()))
167 blob = nullptr;
168
169 return blob;
170 }
171
172 /**
173 * hb_blob_get_empty:
174 *
175 * Returns the singleton empty blob.
176 *
177 * See TODO:link object types for more information.
178 *
179 * Return value: (transfer full): the empty blob.
180 *
181 * Since: 0.9.2
182 **/
183 hb_blob_t *
184 hb_blob_get_empty (void)
185 {
186 static const hb_blob_t _hb_blob_nil = {
187 HB_OBJECT_HEADER_STATIC,
188
189 true, /* immutable */
190
191 nullptr, /* data */
192 0, /* length */
193 HB_MEMORY_MODE_READONLY, /* mode */
194
195 nullptr, /* user_data */
196 nullptr /* destroy */
197 };
198
199 return const_cast<hb_blob_t *> (&_hb_blob_nil);
200 }
201
202 /**
203 * hb_blob_reference: (skip)
204 * @blob: a blob.
205 *
206 * Increases the reference count on @blob.
207 *
208 * See TODO:link object types for more information.
209 *
210 * Return value: @blob.
211 *
212 * Since: 0.9.2
213 **/
214 hb_blob_t *
215 hb_blob_reference (hb_blob_t *blob)
216 {
217 return hb_object_reference (blob);
218 }
219
220 /**
221 * hb_blob_destroy: (skip)
222 * @blob: a blob.
223 *
224 * Decreases the reference count on @blob, and if it reaches zero, destroys
225 * @blob, freeing all memory, possibly calling the destroy-callback the blob
226 * was created for if it has not been called already.
227 *
228 * See TODO:link object types for more information.
229 *
230 * Since: 0.9.2
231 **/
232 void
233 hb_blob_destroy (hb_blob_t *blob)
234 {
235 if (!hb_object_destroy (blob)) return;
236
237 blob->fini_shallow ();
238
239 free (blob);
240 }
241
242 /**
243 * hb_blob_set_user_data: (skip)
244 * @blob: a blob.
245 * @key: key for data to set.
246 * @data: data to set.
247 * @destroy: callback to call when @data is not needed anymore.
248 * @replace: whether to replace an existing data with the same key.
249 *
250 * Return value:
251 *
252 * Since: 0.9.2
253 **/
254 hb_bool_t
255 hb_blob_set_user_data (hb_blob_t *blob,
256 hb_user_data_key_t *key,
257 void * data,
258 hb_destroy_func_t destroy,
259 hb_bool_t replace)
260 {
261 return hb_object_set_user_data (blob, key, data, destroy, replace);
262 }
263
264 /**
265 * hb_blob_get_user_data: (skip)
266 * @blob: a blob.
267 * @key: key for data to get.
268 *
269 *
270 *
271 * Return value: (transfer none):
272 *
273 * Since: 0.9.2
274 **/
275 void *
276 hb_blob_get_user_data (hb_blob_t *blob,
277 hb_user_data_key_t *key)
278 {
279 return hb_object_get_user_data (blob, key);
280 }
281
282
283 /**
284 * hb_blob_make_immutable:
285 * @blob: a blob.
286 *
287 *
288 *
289 * Since: 0.9.2
290 **/
291 void
292 hb_blob_make_immutable (hb_blob_t *blob)
293 {
294 if (hb_object_is_inert (blob))
295 return;
296
297 blob->immutable = true;
298 }
299
300 /**
301 * hb_blob_is_immutable:
302 * @blob: a blob.
303 *
304 *
305 *
306 * Return value: TODO
307 *
308 * Since: 0.9.2
309 **/
310 hb_bool_t
311 hb_blob_is_immutable (hb_blob_t *blob)
312 {
313 return blob->immutable;
314 }
315
316
317 /**
318 * hb_blob_get_length:
319 * @blob: a blob.
320 *
321 *
322 *
323 * Return value: the length of blob data in bytes.
324 *
325 * Since: 0.9.2
326 **/
327 unsigned int
328 hb_blob_get_length (hb_blob_t *blob)
329 {
330 return blob->length;
331 }
332
333 /**
334 * hb_blob_get_data:
335 * @blob: a blob.
336 * @length: (out):
337 *
338 *
339 *
340 * Returns: (transfer none) (array length=length):
341 *
342 * Since: 0.9.2
343 **/
344 const char *
345 hb_blob_get_data (hb_blob_t *blob, unsigned int *length)
346 {
347 if (length)
348 *length = blob->length;
349
350 return blob->data;
351 }
352
353 /**
354 * hb_blob_get_data_writable:
355 * @blob: a blob.
356 * @length: (out): output length of the writable data.
357 *
358 * Tries to make blob data writable (possibly copying it) and
359 * return pointer to data.
360 *
361 * Fails if blob has been made immutable, or if memory allocation
362 * fails.
363 *
364 * Returns: (transfer none) (array length=length): Writable blob data,
365 * or %NULL if failed.
366 *
367 * Since: 0.9.2
368 **/
369 char *
370 hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length)
371 {
372 if (!blob->try_make_writable ()) {
373 if (length)
374 *length = 0;
375
376 return nullptr;
377 }
378
379 if (length)
380 *length = blob->length;
381
382 return const_cast<char *> (blob->data);
383 }
384
385
386 bool
387 hb_blob_t::try_make_writable_inplace_unix (void)
388 {
389 #if defined(HAVE_SYS_MMAN_H) && defined(HAVE_MPROTECT)
390 uintptr_t pagesize = -1, mask, length;
391 const char *addr;
392
393 #if defined(HAVE_SYSCONF) && defined(_SC_PAGE_SIZE)
394 pagesize = (uintptr_t) sysconf (_SC_PAGE_SIZE);
395 #elif defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE)
396 pagesize = (uintptr_t) sysconf (_SC_PAGESIZE);
397 #elif defined(HAVE_GETPAGESIZE)
398 pagesize = (uintptr_t) getpagesize ();
399 #endif
400
401 if ((uintptr_t) -1L == pagesize) {
402 DEBUG_MSG_FUNC (BLOB, this, "failed to get pagesize: %s", strerror (errno));
403 return false;
404 }
405 DEBUG_MSG_FUNC (BLOB, this, "pagesize is %lu", (unsigned long) pagesize);
406
407 mask = ~(pagesize-1);
408 addr = (const char *) (((uintptr_t) this->data) & mask);
409 length = (const char *) (((uintptr_t) this->data + this->length + pagesize-1) & mask) - addr;
410 DEBUG_MSG_FUNC (BLOB, this,
411 "calling mprotect on [%p..%p] (%lu bytes)",
412 addr, addr+length, (unsigned long) length);
413 if (-1 == mprotect ((void *) addr, length, PROT_READ | PROT_WRITE)) {
414 DEBUG_MSG_FUNC (BLOB, this, "mprotect failed: %s", strerror (errno));
415 return false;
416 }
417
418 this->mode = HB_MEMORY_MODE_WRITABLE;
419
420 DEBUG_MSG_FUNC (BLOB, this,
421 "successfully made [%p..%p] (%lu bytes) writable\n",
422 addr, addr+length, (unsigned long) length);
423 return true;
424 #else
425 return false;
426 #endif
427 }
428
429 bool
430 hb_blob_t::try_make_writable_inplace (void)
431 {
432 DEBUG_MSG_FUNC (BLOB, this, "making writable inplace\n");
433
434 if (this->try_make_writable_inplace_unix ())
435 return true;
436
437 DEBUG_MSG_FUNC (BLOB, this, "making writable -> FAILED\n");
438
439 /* Failed to make writable inplace, mark that */
440 this->mode = HB_MEMORY_MODE_READONLY;
441 return false;
442 }
443
444 bool
445 hb_blob_t::try_make_writable (void)
446 {
447 if (this->immutable)
448 return false;
449
450 if (this->mode == HB_MEMORY_MODE_WRITABLE)
451 return true;
452
453 if (this->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE && this->try_make_writable_inplace ())
454 return true;
455
456 if (this->mode == HB_MEMORY_MODE_WRITABLE)
457 return true;
458
459
460 DEBUG_MSG_FUNC (BLOB, this, "current data is -> %p\n", this->data);
461
462 char *new_data;
463
464 new_data = (char *) malloc (this->length);
465 if (unlikely (!new_data))
466 return false;
467
468 DEBUG_MSG_FUNC (BLOB, this, "dupped successfully -> %p\n", this->data);
469
470 memcpy (new_data, this->data, this->length);
471 this->destroy_user_data ();
472 this->mode = HB_MEMORY_MODE_WRITABLE;
473 this->data = new_data;
474 this->user_data = new_data;
475 this->destroy = free;
476
477 return true;
478 }
479
480 /*
481 * Mmap
482 */
483
484 #ifdef HAVE_MMAP
485 # include <sys/types.h>
486 # include <sys/stat.h>
487 # include <fcntl.h>
488 #endif
489
490 #if defined(_WIN32) || defined(__CYGWIN__)
491 # include <windows.h>
492 #else
493 # ifndef _O_BINARY
494 # define _O_BINARY 0
495 # endif
496 #endif
497
498 #ifndef MAP_NORESERVE
499 # define MAP_NORESERVE 0
500 #endif
501
502 struct hb_mapped_file_t
503 {
504 char *contents;
505 unsigned long length;
506 #if defined(_WIN32) || defined(__CYGWIN__)
507 HANDLE mapping;
508 #endif
509 };
510
511 static void
512 _hb_mapped_file_destroy (hb_mapped_file_t *file)
513 {
514 #ifdef HAVE_MMAP
515 munmap (file->contents, file->length);
516 #elif defined(_WIN32) || defined(__CYGWIN__)
517 UnmapViewOfFile (file->contents);
518 CloseHandle (file->mapping);
519 #else
520 assert (0); // If we don't have mmap we shouldn't reach here
521 #endif
522
523 free (file);
524 }
525
526 /**
527 * hb_blob_create_from_file:
528 * @file_name: font filename.
529 *
530 * Returns: A hb_blob_t pointer with the content of the file
531 *
532 * Since: 1.7.7
533 **/
534 hb_blob_t *
535 hb_blob_create_from_file (const char *file_name)
536 {
537 /* Adopted from glib's gmappedfile.c with Matthias Clasen and
538 Allison Lortie permission but changed a lot to suit our need. */
539 #if defined(HAVE_MMAP) && !defined(HB_NO_MMAP)
540 hb_mapped_file_t *file = (hb_mapped_file_t *) calloc (1, sizeof (hb_mapped_file_t));
541 if (unlikely (!file)) return hb_blob_get_empty ();
542
543 int fd = open (file_name, O_RDONLY | _O_BINARY, 0);
544 if (unlikely (fd == -1)) goto fail_without_close;
545
546 struct stat st;
547 if (unlikely (fstat (fd, &st) == -1)) goto fail;
548
549 file->length = (unsigned long) st.st_size;
550 file->contents = (char *) mmap (nullptr, file->length, PROT_READ,
551 MAP_PRIVATE | MAP_NORESERVE, fd, 0);
552
553 if (unlikely (file->contents == MAP_FAILED)) goto fail;
554
555 close (fd);
556
557 return hb_blob_create (file->contents, file->length,
558 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, (void *) file,
559 (hb_destroy_func_t) _hb_mapped_file_destroy);
560
561 fail:
562 close (fd);
563 fail_without_close:
564 free (file);
565
566 #elif (defined(_WIN32) || defined(__CYGWIN__)) && !defined(HB_NO_MMAP)
567 hb_mapped_file_t *file = (hb_mapped_file_t *) calloc (1, sizeof (hb_mapped_file_t));
568 if (unlikely (!file)) return hb_blob_get_empty ();
569
570 HANDLE fd = CreateFile (file_name, GENERIC_READ, FILE_SHARE_READ, nullptr,
571 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,
572 nullptr);
573
574 if (unlikely (fd == INVALID_HANDLE_VALUE)) goto fail_without_close;
575
576 file->length = (unsigned long) GetFileSize (fd, nullptr);
577 file->mapping = CreateFileMapping (fd, nullptr, PAGE_READONLY, 0, 0, nullptr);
578 if (unlikely (file->mapping == nullptr)) goto fail;
579
580 file->contents = (char *) MapViewOfFile (file->mapping, FILE_MAP_READ, 0, 0, 0);
581 if (unlikely (file->contents == nullptr)) goto fail;
582
583 CloseHandle (fd);
584 return hb_blob_create (file->contents, file->length,
585 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, (void *) file,
586 (hb_destroy_func_t) _hb_mapped_file_destroy);
587
588 fail:
589 CloseHandle (fd);
590 fail_without_close:
591 free (file);
592
593 #endif
594
595 /* The following tries to read a file without knowing its size beforehand
596 It's used as a fallback for systems without mmap or to read from pipes */
597 unsigned long len = 0, allocated = BUFSIZ * 16;
598 char *data = (char *) malloc (allocated);
599 if (unlikely (data == nullptr)) return hb_blob_get_empty ();
600
601 FILE *fp = fopen (file_name, "rb");
602 if (unlikely (fp == nullptr)) goto fread_fail_without_close;
603
604 while (!feof (fp))
605 {
606 if (allocated - len < BUFSIZ)
607 {
608 allocated *= 2;
609 /* Don't allocate and go more than ~536MB, our mmap reader still
610 can cover files like that but lets limit our fallback reader */
611 if (unlikely (allocated > (2 << 28))) goto fread_fail;
612 char *new_data = (char *) realloc (data, allocated);
613 if (unlikely (new_data == nullptr)) goto fread_fail;
614 data = new_data;
615 }
616
617 unsigned long addition = fread (data + len, 1, allocated - len, fp);
618
619 int err = ferror (fp);
620 #ifdef EINTR // armcc doesn't have it
621 if (unlikely (err == EINTR)) continue;
622 #endif
623 if (unlikely (err)) goto fread_fail;
624
625 len += addition;
626 }
627
628 return hb_blob_create (data, len, HB_MEMORY_MODE_WRITABLE, data,
629 (hb_destroy_func_t) free);
630
631 fread_fail:
632 fclose (fp);
633 fread_fail_without_close:
634 free (data);
635 return hb_blob_get_empty ();
636 }