1 /*
2 * resource.c
3 *
4 * Code for reading blobs and resources, including compressed WIM resources.
5 */
6
7 /*
8 * Copyright (C) 2012, 2013, 2015 Eric Biggers
9 *
10 * This file is free software; you can redistribute it and/or modify it under
11 * the terms of the GNU Lesser General Public License as published by the Free
12 * Software Foundation; either version 3 of the License, or (at your option) any
13 * later version.
14 *
15 * This file is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this file; if not, see http://www.gnu.org/licenses/.
22 */
23
24 #ifdef HAVE_CONFIG_H
25 # include "config.h"
26 #endif
27
28 #include <errno.h>
29 #include <fcntl.h>
30 #include <unistd.h>
31
32 #include "wimlib/alloca.h"
33 #include "wimlib/assert.h"
34 #include "wimlib/bitops.h"
35 #include "wimlib/blob_table.h"
36 #include "wimlib/endianness.h"
37 #include "wimlib/error.h"
38 #include "wimlib/file_io.h"
39 #include "wimlib/ntfs_3g.h"
40 #include "wimlib/resource.h"
41 #include "wimlib/sha1.h"
42 #include "wimlib/wim.h"
43 #include "wimlib/win32.h"
44
45 /*
46 * Compressed WIM resources
47 *
48 * A compressed resource in a WIM consists of a sequence of chunks. Each chunk
49 * decompresses to the same size except possibly for the last, which
50 * decompresses to the remaining size. Chunks that did not compress to less
51 * than their original size are stored uncompressed.
52 *
53 * We support three variations on this resource format, independently of the
54 * compression type and chunk size which can vary as well:
55 *
56 * - Original resource format: immediately before the compressed chunks, the
57 * "chunk table" provides the offset, in bytes relative to the end of the
58 * chunk table, of the start of each compressed chunk, except for the first
59 * chunk which is omitted as it always has an offset of 0. Chunk table
60 * entries are 32-bit for resources < 4 GiB uncompressed and 64-bit for
61 * resources >= 4 GiB uncompressed.
62 *
63 * - Solid resource format (distinguished by the use of WIM_RESHDR_FLAG_SOLID
64 * instead of WIM_RESHDR_FLAG_COMPRESSED): similar to the original format, but
65 * the resource begins with a 16-byte header which specifies the uncompressed
66 * size of the resource, the compression type, and the chunk size. (In the
67 * original format, these values were instead determined from outside the
68 * resource itself, from the blob table and the WIM file header.) In addition,
69 * in this format the entries in the chunk table contain compressed chunk
70 * sizes rather than offsets. As a consequence of this, the chunk table
71 * entries are always 32-bit and there is an entry for chunk 0.
72 *
73 * - Pipable resource format (wimlib extension; all resources in a pipable WIM
74 * have this format): similar to the original format, but the chunk table is
75 * at the end of the resource rather than the beginning, and each compressed
76 * chunk is prefixed with its compressed size as a 32-bit integer. This
77 * format allows a resource to be written without rewinding.
78 */
79
80
81 struct data_range {
82 u64 offset;
83 u64 size;
84 };
85
86 /*
87 * Read data from a compressed WIM resource.
88 *
89 * @rdesc
90 * Description of the compressed WIM resource to read from.
91 * @ranges
92 * Nonoverlapping, nonempty ranges of the uncompressed resource data to
93 * read, sorted by increasing offset.
94 * @num_ranges
95 * Number of ranges in @ranges; must be at least 1.
96 * @cb
97 * Structure which provides the consume_chunk callback into which to feed
98 * the data being read. Each call provides the next chunk of the requested
99 * data, uncompressed. Each chunk will be nonempty and will not cross
100 * range boundaries but otherwise will be of unspecified size.
101 *
102 * Possible return values:
103 *
104 * WIMLIB_ERR_SUCCESS (0)
105 * WIMLIB_ERR_READ (errno set)
106 * WIMLIB_ERR_UNEXPECTED_END_OF_FILE (errno set to EINVAL)
107 * WIMLIB_ERR_NOMEM (errno set to ENOMEM)
108 * WIMLIB_ERR_DECOMPRESSION (errno set to EINVAL)
109 * WIMLIB_ERR_INVALID_CHUNK_SIZE (errno set to EINVAL)
110 *
111 * or other error code returned by the callback function.
112 */
113 static int
read_compressed_wim_resource(const struct wim_resource_descriptor * const rdesc,const struct data_range * const ranges,const size_t num_ranges,const struct consume_chunk_callback * cb)114 read_compressed_wim_resource(const struct wim_resource_descriptor * const rdesc,
115 const struct data_range * const ranges,
116 const size_t num_ranges,
117 const struct consume_chunk_callback *cb)
118 {
119 int ret;
120 u64 *chunk_offsets = NULL;
121 u8 *ubuf = NULL;
122 void *cbuf = NULL;
123 bool chunk_offsets_malloced = false;
124 bool ubuf_malloced = false;
125 bool cbuf_malloced = false;
126 struct wimlib_decompressor *decompressor = NULL;
127
128 /* Sanity checks */
129 wimlib_assert(num_ranges != 0);
130 for (size_t i = 0; i < num_ranges; i++) {
131 wimlib_assert(ranges[i].offset + ranges[i].size > ranges[i].offset &&
132 ranges[i].offset + ranges[i].size <= rdesc->uncompressed_size);
133 }
134 for (size_t i = 0; i < num_ranges - 1; i++)
135 wimlib_assert(ranges[i].offset + ranges[i].size <= ranges[i + 1].offset);
136
137 /* Get the offsets of the first and last bytes of the read. */
138 const u64 first_offset = ranges[0].offset;
139 const u64 last_offset = ranges[num_ranges - 1].offset + ranges[num_ranges - 1].size - 1;
140
141 /* Get the file descriptor for the WIM. */
142 struct filedes * const in_fd = &rdesc->wim->in_fd;
143
144 /* Determine if we're reading a pipable resource from a pipe or not. */
145 const bool is_pipe_read = (rdesc->is_pipable && !filedes_is_seekable(in_fd));
146
147 /* Determine if the chunk table is in an alternate format. */
148 const bool alt_chunk_table = (rdesc->flags & WIM_RESHDR_FLAG_SOLID)
149 && !is_pipe_read;
150
151 /* Get the maximum size of uncompressed chunks in this resource, which
152 * we require be a power of 2. */
153 u64 cur_read_offset = rdesc->offset_in_wim;
154 int ctype = rdesc->compression_type;
155 u32 chunk_size = rdesc->chunk_size;
156 if (alt_chunk_table) {
157 /* Alternate chunk table format. Its header specifies the chunk
158 * size and compression format. Note: it could be read here;
159 * however, the relevant data was already loaded into @rdesc by
160 * read_blob_table(). */
161 cur_read_offset += sizeof(struct alt_chunk_table_header_disk);
162 }
163
164 if (unlikely(!is_power_of_2(chunk_size))) {
165 ERROR("Invalid compressed resource: "
166 "expected power-of-2 chunk size (got %"PRIu32")",
167 chunk_size);
168 ret = WIMLIB_ERR_INVALID_CHUNK_SIZE;
169 errno = EINVAL;
170 goto out_cleanup;
171 }
172
173 /* Get valid decompressor. */
174 if (likely(ctype == rdesc->wim->decompressor_ctype &&
175 chunk_size == rdesc->wim->decompressor_max_block_size))
176 {
177 /* Cached decompressor. */
178 decompressor = rdesc->wim->decompressor;
179 rdesc->wim->decompressor_ctype = WIMLIB_COMPRESSION_TYPE_NONE;
180 rdesc->wim->decompressor = NULL;
181 } else {
182 ret = wimlib_create_decompressor(ctype, chunk_size,
183 &decompressor);
184 if (unlikely(ret)) {
185 if (ret != WIMLIB_ERR_NOMEM)
186 errno = EINVAL;
187 goto out_cleanup;
188 }
189 }
190
191 const u32 chunk_order = bsr32(chunk_size);
192
193 /* Calculate the total number of chunks the resource is divided into. */
194 const u64 num_chunks = (rdesc->uncompressed_size + chunk_size - 1) >> chunk_order;
195
196 /* Calculate the 0-based indices of the first and last chunks containing
197 * data that needs to be passed to the callback. */
198 const u64 first_needed_chunk = first_offset >> chunk_order;
199 const u64 last_needed_chunk = last_offset >> chunk_order;
200
201 /* Calculate the 0-based index of the first chunk that actually needs to
202 * be read. This is normally first_needed_chunk, but for pipe reads we
203 * must always start from the 0th chunk. */
204 const u64 read_start_chunk = (is_pipe_read ? 0 : first_needed_chunk);
205
206 /* Calculate the number of chunk offsets that are needed for the chunks
207 * being read. */
208 const u64 num_needed_chunk_offsets =
209 last_needed_chunk - read_start_chunk + 1 +
210 (last_needed_chunk < num_chunks - 1);
211
212 /* Calculate the number of entries in the chunk table. Normally, it's
213 * one less than the number of chunks, since the first chunk has no
214 * entry. But in the alternate chunk table format, the chunk entries
215 * contain chunk sizes, not offsets, and there is one per chunk. */
216 const u64 num_chunk_entries = (alt_chunk_table ? num_chunks : num_chunks - 1);
217
218 /* Set the size of each chunk table entry based on the resource's
219 * uncompressed size. */
220 const u64 chunk_entry_size = get_chunk_entry_size(rdesc->uncompressed_size,
221 alt_chunk_table);
222
223 /* Calculate the size of the chunk table in bytes. */
224 const u64 chunk_table_size = num_chunk_entries * chunk_entry_size;
225
226 /* Calculate the size of the chunk table in bytes, including the header
227 * in the case of the alternate chunk table format. */
228 const u64 chunk_table_full_size =
229 (alt_chunk_table) ? chunk_table_size + sizeof(struct alt_chunk_table_header_disk)
230 : chunk_table_size;
231
232 if (!is_pipe_read) {
233 /* Read the needed chunk table entries into memory and use them
234 * to initialize the chunk_offsets array. */
235
236 u64 first_chunk_entry_to_read;
237 u64 num_chunk_entries_to_read;
238
239 if (alt_chunk_table) {
240 /* The alternate chunk table contains chunk sizes, not
241 * offsets, so we always must read all preceding entries
242 * in order to determine offsets. */
243 first_chunk_entry_to_read = 0;
244 num_chunk_entries_to_read = last_needed_chunk + 1;
245 } else {
246
247 num_chunk_entries_to_read = last_needed_chunk - read_start_chunk + 1;
248
249 /* The first chunk has no explicit chunk table entry. */
250 if (read_start_chunk == 0) {
251 num_chunk_entries_to_read--;
252 first_chunk_entry_to_read = 0;
253 } else {
254 first_chunk_entry_to_read = read_start_chunk - 1;
255 }
256
257 /* Unless we're reading the final chunk of the resource,
258 * we need the offset of the chunk following the last
259 * needed chunk so that the compressed size of the last
260 * needed chunk can be computed. */
261 if (last_needed_chunk < num_chunks - 1)
262 num_chunk_entries_to_read++;
263 }
264
265 const u64 chunk_offsets_alloc_size =
266 max(num_chunk_entries_to_read,
267 num_needed_chunk_offsets) * sizeof(chunk_offsets[0]);
268
269 if (unlikely((size_t)chunk_offsets_alloc_size != chunk_offsets_alloc_size)) {
270 errno = ENOMEM;
271 goto oom;
272 }
273
274 if (likely(chunk_offsets_alloc_size <= STACK_MAX)) {
275 chunk_offsets = alloca(chunk_offsets_alloc_size);
276 } else {
277 chunk_offsets = MALLOC(chunk_offsets_alloc_size);
278 if (unlikely(!chunk_offsets))
279 goto oom;
280 chunk_offsets_malloced = true;
281 }
282
283 const size_t chunk_table_size_to_read =
284 num_chunk_entries_to_read * chunk_entry_size;
285
286 const u64 file_offset_of_needed_chunk_entries =
287 cur_read_offset
288 + (first_chunk_entry_to_read * chunk_entry_size)
289 + (rdesc->is_pipable ? (rdesc->size_in_wim - chunk_table_size) : 0);
290
291 void * const chunk_table_data =
292 (u8*)chunk_offsets +
293 chunk_offsets_alloc_size -
294 chunk_table_size_to_read;
295
296 ret = full_pread(in_fd, chunk_table_data, chunk_table_size_to_read,
297 file_offset_of_needed_chunk_entries);
298 if (unlikely(ret))
299 goto read_error;
300
301 /* Now fill in chunk_offsets from the entries we have read in
302 * chunk_tab_data. We break aliasing rules here to avoid having
303 * to allocate yet another array. */
304 typedef le64 _may_alias_attribute aliased_le64_t;
305 typedef le32 _may_alias_attribute aliased_le32_t;
306 u64 * chunk_offsets_p = chunk_offsets;
307
308 if (alt_chunk_table) {
309 u64 cur_offset = 0;
310 aliased_le32_t *raw_entries = chunk_table_data;
311
312 for (size_t i = 0; i < num_chunk_entries_to_read; i++) {
313 u32 entry = le32_to_cpu(raw_entries[i]);
314 if (i >= read_start_chunk)
315 *chunk_offsets_p++ = cur_offset;
316 cur_offset += entry;
317 }
318 if (last_needed_chunk < num_chunks - 1)
319 *chunk_offsets_p = cur_offset;
320 } else {
321 if (read_start_chunk == 0)
322 *chunk_offsets_p++ = 0;
323
324 if (chunk_entry_size == 4) {
325 aliased_le32_t *raw_entries = chunk_table_data;
326 for (size_t i = 0; i < num_chunk_entries_to_read; i++)
327 *chunk_offsets_p++ = le32_to_cpu(raw_entries[i]);
328 } else {
329 aliased_le64_t *raw_entries = chunk_table_data;
330 for (size_t i = 0; i < num_chunk_entries_to_read; i++)
331 *chunk_offsets_p++ = le64_to_cpu(raw_entries[i]);
332 }
333 }
334
335 /* Set offset to beginning of first chunk to read. */
336 cur_read_offset += chunk_offsets[0];
337 if (rdesc->is_pipable)
338 cur_read_offset += read_start_chunk * sizeof(struct pwm_chunk_hdr);
339 else
340 cur_read_offset += chunk_table_size;
341 }
342
343 /* Allocate buffer for holding the uncompressed data of each chunk. */
344 if (chunk_size <= STACK_MAX) {
345 ubuf = alloca(chunk_size);
346 } else {
347 ubuf = MALLOC(chunk_size);
348 if (unlikely(!ubuf))
349 goto oom;
350 ubuf_malloced = true;
351 }
352
353 /* Allocate a temporary buffer for reading compressed chunks, each of
354 * which can be at most @chunk_size - 1 bytes. This excludes compressed
355 * chunks that are a full @chunk_size bytes, which are actually stored
356 * uncompressed. */
357 if (chunk_size - 1 <= STACK_MAX) {
358 cbuf = alloca(chunk_size - 1);
359 } else {
360 cbuf = MALLOC(chunk_size - 1);
361 if (unlikely(!cbuf))
362 goto oom;
363 cbuf_malloced = true;
364 }
365
366 /* Set current data range. */
367 const struct data_range *cur_range = ranges;
368 const struct data_range * const end_range = &ranges[num_ranges];
369 u64 cur_range_pos = cur_range->offset;
370 u64 cur_range_end = cur_range->offset + cur_range->size;
371
372 /* Read and process each needed chunk. */
373 for (u64 i = read_start_chunk; i <= last_needed_chunk; i++) {
374
375 /* Calculate uncompressed size of next chunk. */
376 u32 chunk_usize;
377 if ((i == num_chunks - 1) && (rdesc->uncompressed_size & (chunk_size - 1)))
378 chunk_usize = (rdesc->uncompressed_size & (chunk_size - 1));
379 else
380 chunk_usize = chunk_size;
381
382 /* Calculate compressed size of next chunk. */
383 u32 chunk_csize;
384 if (is_pipe_read) {
385 struct pwm_chunk_hdr chunk_hdr;
386
387 ret = full_pread(in_fd, &chunk_hdr,
388 sizeof(chunk_hdr), cur_read_offset);
389 if (unlikely(ret))
390 goto read_error;
391 chunk_csize = le32_to_cpu(chunk_hdr.compressed_size);
392 } else {
393 if (i == num_chunks - 1) {
394 chunk_csize = rdesc->size_in_wim -
395 chunk_table_full_size -
396 chunk_offsets[i - read_start_chunk];
397 if (rdesc->is_pipable)
398 chunk_csize -= num_chunks * sizeof(struct pwm_chunk_hdr);
399 } else {
400 chunk_csize = chunk_offsets[i + 1 - read_start_chunk] -
401 chunk_offsets[i - read_start_chunk];
402 }
403 }
404 if (unlikely(chunk_csize == 0 || chunk_csize > chunk_usize)) {
405 ERROR("Invalid chunk size in compressed resource!");
406 errno = EINVAL;
407 ret = WIMLIB_ERR_DECOMPRESSION;
408 goto out_cleanup;
409 }
410 if (rdesc->is_pipable)
411 cur_read_offset += sizeof(struct pwm_chunk_hdr);
412
413 /* Offsets in the uncompressed resource at which this chunk
414 * starts and ends. */
415 const u64 chunk_start_offset = i << chunk_order;
416 const u64 chunk_end_offset = chunk_start_offset + chunk_usize;
417
418 if (chunk_end_offset <= cur_range_pos) {
419
420 /* The next range does not require data in this chunk,
421 * so skip it. */
422 cur_read_offset += chunk_csize;
423 if (is_pipe_read) {
424 u8 dummy;
425
426 ret = full_pread(in_fd, &dummy, 1, cur_read_offset - 1);
427 if (unlikely(ret))
428 goto read_error;
429 }
430 } else {
431
432 /* Read the chunk and feed data to the callback
433 * function. */
434 u8 *read_buf;
435
436 if (chunk_csize == chunk_usize)
437 read_buf = ubuf;
438 else
439 read_buf = cbuf;
440
441 ret = full_pread(in_fd,
442 read_buf,
443 chunk_csize,
444 cur_read_offset);
445 if (unlikely(ret))
446 goto read_error;
447
448 if (read_buf == cbuf) {
449 ret = wimlib_decompress(cbuf,
450 chunk_csize,
451 ubuf,
452 chunk_usize,
453 decompressor);
454 if (unlikely(ret)) {
455 ERROR("Failed to decompress data!");
456 ret = WIMLIB_ERR_DECOMPRESSION;
457 errno = EINVAL;
458 goto out_cleanup;
459 }
460 }
461 cur_read_offset += chunk_csize;
462
463 /* At least one range requires data in this chunk. */
464 do {
465 size_t start, end, size;
466
467 /* Calculate how many bytes of data should be
468 * sent to the callback function, taking into
469 * account that data sent to the callback
470 * function must not overlap range boundaries.
471 */
472 start = cur_range_pos - chunk_start_offset;
473 end = min(cur_range_end, chunk_end_offset) - chunk_start_offset;
474 size = end - start;
475
476 ret = consume_chunk(cb, &ubuf[start], size);
477 if (unlikely(ret))
478 goto out_cleanup;
479
480 cur_range_pos += size;
481 if (cur_range_pos == cur_range_end) {
482 /* Advance to next range. */
483 if (++cur_range == end_range) {
484 cur_range_pos = ~0ULL;
485 } else {
486 cur_range_pos = cur_range->offset;
487 cur_range_end = cur_range->offset + cur_range->size;
488 }
489 }
490 } while (cur_range_pos < chunk_end_offset);
491 }
492 }
493
494 if (is_pipe_read &&
495 last_offset == rdesc->uncompressed_size - 1 &&
496 chunk_table_size)
497 {
498 u8 dummy;
499 /* If reading a pipable resource from a pipe and the full data
500 * was requested, skip the chunk table at the end so that the
501 * file descriptor is fully clear of the resource after this
502 * returns. */
503 cur_read_offset += chunk_table_size;
504 ret = full_pread(in_fd, &dummy, 1, cur_read_offset - 1);
505 if (unlikely(ret))
506 goto read_error;
507 }
508 ret = 0;
509
510 out_cleanup:
511 if (decompressor) {
512 wimlib_free_decompressor(rdesc->wim->decompressor);
513 rdesc->wim->decompressor = decompressor;
514 rdesc->wim->decompressor_ctype = ctype;
515 rdesc->wim->decompressor_max_block_size = chunk_size;
516 }
517 if (chunk_offsets_malloced)
518 FREE(chunk_offsets);
519 if (ubuf_malloced)
520 FREE(ubuf);
521 if (cbuf_malloced)
522 FREE(cbuf);
523 return ret;
524
525 oom:
526 ERROR("Out of memory while reading compressed WIM resource");
527 ret = WIMLIB_ERR_NOMEM;
528 goto out_cleanup;
529
530 read_error:
531 ERROR_WITH_ERRNO("Error reading data from WIM file");
532 goto out_cleanup;
533 }
534
535 /* Read raw data from a file descriptor at the specified offset, feeding the
536 * data in nonempty chunks into the specified callback function. */
537 static int
read_raw_file_data(struct filedes * in_fd,u64 offset,u64 size,const struct consume_chunk_callback * cb,const tchar * filename)538 read_raw_file_data(struct filedes *in_fd, u64 offset, u64 size,
539 const struct consume_chunk_callback *cb,
540 const tchar *filename)
541 {
542 u8 buf[BUFFER_SIZE];
543 size_t bytes_to_read;
544 int ret;
545
546 while (size) {
547 bytes_to_read = min(sizeof(buf), size);
548 ret = full_pread(in_fd, buf, bytes_to_read, offset);
549 if (unlikely(ret))
550 goto read_error;
551 ret = consume_chunk(cb, buf, bytes_to_read);
552 if (unlikely(ret))
553 return ret;
554 size -= bytes_to_read;
555 offset += bytes_to_read;
556 }
557 return 0;
558
559 read_error:
560 if (!filename) {
561 ERROR_WITH_ERRNO("Error reading data from WIM file");
562 } else if (ret == WIMLIB_ERR_UNEXPECTED_END_OF_FILE) {
563 ERROR("\"%"TS"\": File was concurrently truncated", filename);
564 ret = WIMLIB_ERR_CONCURRENT_MODIFICATION_DETECTED;
565 } else {
566 ERROR_WITH_ERRNO("\"%"TS"\": Error reading data", filename);
567 }
568 return ret;
569 }
570
571 /* A consume_chunk implementation which simply concatenates all chunks into an
572 * in-memory buffer. */
573 static int
bufferer_cb(const void * chunk,size_t size,void * _ctx)574 bufferer_cb(const void *chunk, size_t size, void *_ctx)
575 {
576 void **buf_p = _ctx;
577
578 *buf_p = mempcpy(*buf_p, chunk, size);
579 return 0;
580 }
581
582 /*
583 * Read @size bytes at @offset in the WIM resource described by @rdesc and feed
584 * the data into the @cb callback function.
585 *
586 * @offset and @size are assumed to have already been validated against the
587 * resource's uncompressed size.
588 *
589 * Returns 0 on success; or the first nonzero value returned by the callback
590 * function; or a nonzero wimlib error code with errno set as well.
591 */
592 static int
read_partial_wim_resource(const struct wim_resource_descriptor * rdesc,const u64 offset,const u64 size,const struct consume_chunk_callback * cb)593 read_partial_wim_resource(const struct wim_resource_descriptor *rdesc,
594 const u64 offset, const u64 size,
595 const struct consume_chunk_callback *cb)
596 {
597 if (rdesc->flags & (WIM_RESHDR_FLAG_COMPRESSED |
598 WIM_RESHDR_FLAG_SOLID))
599 {
600 /* Compressed resource */
601 if (unlikely(!size))
602 return 0;
603 struct data_range range = {
604 .offset = offset,
605 .size = size,
606 };
607 return read_compressed_wim_resource(rdesc, &range, 1, cb);
608 }
609
610 /* Uncompressed resource */
611 return read_raw_file_data(&rdesc->wim->in_fd,
612 rdesc->offset_in_wim + offset,
613 size, cb, NULL);
614 }
615
616 /* Read the specified range of uncompressed data from the specified blob, which
617 * must be located in a WIM file, into the specified buffer. */
618 int
read_partial_wim_blob_into_buf(const struct blob_descriptor * blob,u64 offset,size_t size,void * buf)619 read_partial_wim_blob_into_buf(const struct blob_descriptor *blob,
620 u64 offset, size_t size, void *buf)
621 {
622 struct consume_chunk_callback cb = {
623 .func = bufferer_cb,
624 .ctx = &buf,
625 };
626 return read_partial_wim_resource(blob->rdesc,
627 blob->offset_in_res + offset,
628 size,
629 &cb);
630 }
631
632 static int
noop_cb(const void * chunk,size_t size,void * _ctx)633 noop_cb(const void *chunk, size_t size, void *_ctx)
634 {
635 return 0;
636 }
637
638 /* Skip over the data of the specified WIM resource. */
639 int
skip_wim_resource(const struct wim_resource_descriptor * rdesc)640 skip_wim_resource(const struct wim_resource_descriptor *rdesc)
641 {
642 static const struct consume_chunk_callback cb = {
643 .func = noop_cb,
644 };
645 return read_partial_wim_resource(rdesc, 0,
646 rdesc->uncompressed_size, &cb);
647 }
648
649 static int
read_wim_blob_prefix(const struct blob_descriptor * blob,u64 size,const struct consume_chunk_callback * cb)650 read_wim_blob_prefix(const struct blob_descriptor *blob, u64 size,
651 const struct consume_chunk_callback *cb)
652 {
653 return read_partial_wim_resource(blob->rdesc, blob->offset_in_res,
654 size, cb);
655 }
656
657 /* This function handles reading blob data that is located in an external file,
658 * such as a file that has been added to the WIM image through execution of a
659 * wimlib_add_command.
660 *
661 * This assumes the file can be accessed using the standard POSIX open(),
662 * read(), and close(). On Windows this will not necessarily be the case (since
663 * the file may need FILE_FLAG_BACKUP_SEMANTICS to be opened, or the file may be
664 * encrypted), so Windows uses its own code for its equivalent case. */
665 static int
read_file_on_disk_prefix(const struct blob_descriptor * blob,u64 size,const struct consume_chunk_callback * cb)666 read_file_on_disk_prefix(const struct blob_descriptor *blob, u64 size,
667 const struct consume_chunk_callback *cb)
668 {
669 int ret;
670 int raw_fd;
671 struct filedes fd;
672
673 raw_fd = topen(blob->file_on_disk, O_BINARY | O_RDONLY);
674 if (unlikely(raw_fd < 0)) {
675 ERROR_WITH_ERRNO("Can't open \"%"TS"\"", blob->file_on_disk);
676 return WIMLIB_ERR_OPEN;
677 }
678 filedes_init(&fd, raw_fd);
679 ret = read_raw_file_data(&fd, 0, size, cb, blob->file_on_disk);
680 filedes_close(&fd);
681 return ret;
682 }
683
684 #ifdef WITH_FUSE
685 static int
read_staging_file_prefix(const struct blob_descriptor * blob,u64 size,const struct consume_chunk_callback * cb)686 read_staging_file_prefix(const struct blob_descriptor *blob, u64 size,
687 const struct consume_chunk_callback *cb)
688 {
689 int raw_fd;
690 struct filedes fd;
691 int ret;
692
693 raw_fd = openat(blob->staging_dir_fd, blob->staging_file_name,
694 O_RDONLY | O_NOFOLLOW);
695 if (unlikely(raw_fd < 0)) {
696 ERROR_WITH_ERRNO("Can't open staging file \"%s\"",
697 blob->staging_file_name);
698 return WIMLIB_ERR_OPEN;
699 }
700 filedes_init(&fd, raw_fd);
701 ret = read_raw_file_data(&fd, 0, size, cb, blob->staging_file_name);
702 filedes_close(&fd);
703 return ret;
704 }
705 #endif
706
707 /* This function handles the trivial case of reading blob data that is, in fact,
708 * already located in an in-memory buffer. */
709 static int
read_buffer_prefix(const struct blob_descriptor * blob,u64 size,const struct consume_chunk_callback * cb)710 read_buffer_prefix(const struct blob_descriptor *blob,
711 u64 size, const struct consume_chunk_callback *cb)
712 {
713 if (unlikely(!size))
714 return 0;
715 return consume_chunk(cb, blob->attached_buffer, size);
716 }
717
718 typedef int (*read_blob_prefix_handler_t)(const struct blob_descriptor *blob,
719 u64 size,
720 const struct consume_chunk_callback *cb);
721
722 /*
723 * Read the first @size bytes from a generic "blob", which may be located in any
724 * one of several locations, such as in a WIM resource (possibly compressed), in
725 * an external file, or directly in an in-memory buffer. The blob data will be
726 * fed to @cb in chunks that are nonempty but otherwise are of unspecified size.
727 *
728 * Returns 0 on success; nonzero on error. A nonzero value will be returned if
729 * the blob data cannot be successfully read (for a number of different reasons,
730 * depending on the blob location), or if @cb returned nonzero in which case
731 * that error code will be returned.
732 */
733 static int
read_blob_prefix(const struct blob_descriptor * blob,u64 size,const struct consume_chunk_callback * cb)734 read_blob_prefix(const struct blob_descriptor *blob, u64 size,
735 const struct consume_chunk_callback *cb)
736 {
737 static const read_blob_prefix_handler_t handlers[] = {
738 [BLOB_IN_WIM] = read_wim_blob_prefix,
739 [BLOB_IN_FILE_ON_DISK] = read_file_on_disk_prefix,
740 [BLOB_IN_ATTACHED_BUFFER] = read_buffer_prefix,
741 #ifdef WITH_FUSE
742 [BLOB_IN_STAGING_FILE] = read_staging_file_prefix,
743 #endif
744 #ifdef WITH_NTFS_3G
745 [BLOB_IN_NTFS_VOLUME] = read_ntfs_attribute_prefix,
746 #endif
747 #ifdef __WIN32__
748 [BLOB_IN_WINDOWS_FILE] = read_windows_file_prefix,
749 #endif
750 };
751 wimlib_assert(blob->blob_location < ARRAY_LEN(handlers)
752 && handlers[blob->blob_location] != NULL);
753 wimlib_assert(size <= blob->size);
754 return handlers[blob->blob_location](blob, size, cb);
755 }
756
757 struct blob_chunk_ctx {
758 const struct blob_descriptor *blob;
759 const struct read_blob_callbacks *cbs;
760 u64 offset;
761 };
762
763 static int
consume_blob_chunk(const void * chunk,size_t size,void * _ctx)764 consume_blob_chunk(const void *chunk, size_t size, void *_ctx)
765 {
766 struct blob_chunk_ctx *ctx = _ctx;
767 int ret;
768
769 ret = call_continue_blob(ctx->blob, ctx->offset, chunk, size, ctx->cbs);
770 ctx->offset += size;
771 return ret;
772 }
773
774 /* Read the full data of the specified blob, passing the data into the specified
775 * callbacks (all of which are optional). */
776 int
read_blob_with_cbs(struct blob_descriptor * blob,const struct read_blob_callbacks * cbs)777 read_blob_with_cbs(struct blob_descriptor *blob,
778 const struct read_blob_callbacks *cbs)
779 {
780 int ret;
781 struct blob_chunk_ctx ctx = {
782 .blob = blob,
783 .offset = 0,
784 .cbs = cbs,
785 };
786 struct consume_chunk_callback cb = {
787 .func = consume_blob_chunk,
788 .ctx = &ctx,
789 };
790
791 ret = call_begin_blob(blob, cbs);
792 if (unlikely(ret))
793 return ret;
794
795 ret = read_blob_prefix(blob, blob->size, &cb);
796
797 return call_end_blob(blob, ret, cbs);
798 }
799
800 /* Read the full uncompressed data of the specified blob into the specified
801 * buffer, which must have space for at least blob->size bytes. The SHA-1
802 * message digest is *not* checked. */
803 int
read_blob_into_buf(const struct blob_descriptor * blob,void * buf)804 read_blob_into_buf(const struct blob_descriptor *blob, void *buf)
805 {
806 struct consume_chunk_callback cb = {
807 .func = bufferer_cb,
808 .ctx = &buf,
809 };
810 return read_blob_prefix(blob, blob->size, &cb);
811 }
812
813 /* Retrieve the full uncompressed data of the specified blob. A buffer large
814 * enough hold the data is allocated and returned in @buf_ret. The SHA-1
815 * message digest is *not* checked. */
816 int
read_blob_into_alloc_buf(const struct blob_descriptor * blob,void ** buf_ret)817 read_blob_into_alloc_buf(const struct blob_descriptor *blob, void **buf_ret)
818 {
819 int ret;
820 void *buf;
821
822 if (unlikely((size_t)blob->size != blob->size)) {
823 ERROR("Can't read %"PRIu64" byte blob into memory", blob->size);
824 return WIMLIB_ERR_NOMEM;
825 }
826
827 buf = MALLOC(blob->size);
828 if (unlikely(!buf))
829 return WIMLIB_ERR_NOMEM;
830
831 ret = read_blob_into_buf(blob, buf);
832 if (unlikely(ret)) {
833 FREE(buf);
834 return ret;
835 }
836
837 *buf_ret = buf;
838 return 0;
839 }
840
841 /* Retrieve the full uncompressed data of a WIM resource specified as a raw
842 * `wim_reshdr' and the corresponding WIM file. A buffer large enough hold the
843 * data is allocated and returned in @buf_ret. */
844 int
wim_reshdr_to_data(const struct wim_reshdr * reshdr,WIMStruct * wim,void ** buf_ret)845 wim_reshdr_to_data(const struct wim_reshdr *reshdr, WIMStruct *wim,
846 void **buf_ret)
847 {
848 struct wim_resource_descriptor rdesc;
849 struct blob_descriptor blob;
850
851 wim_reshdr_to_desc_and_blob(reshdr, wim, &rdesc, &blob);
852
853 return read_blob_into_alloc_buf(&blob, buf_ret);
854 }
855
856 /* Calculate the SHA-1 message digest of the uncompressed data of the specified
857 * WIM resource. */
858 int
wim_reshdr_to_hash(const struct wim_reshdr * reshdr,WIMStruct * wim,u8 hash[SHA1_HASH_SIZE])859 wim_reshdr_to_hash(const struct wim_reshdr *reshdr, WIMStruct *wim,
860 u8 hash[SHA1_HASH_SIZE])
861 {
862 struct wim_resource_descriptor rdesc;
863 struct blob_descriptor blob;
864 int ret;
865
866 wim_reshdr_to_desc_and_blob(reshdr, wim, &rdesc, &blob);
867 blob.unhashed = 1;
868
869 ret = sha1_blob(&blob);
870 if (unlikely(ret))
871 return ret;
872
873 copy_hash(hash, blob.hash);
874 return 0;
875 }
876
877 struct blobifier_context {
878 struct read_blob_callbacks cbs;
879 struct blob_descriptor *cur_blob;
880 struct blob_descriptor *next_blob;
881 u64 cur_blob_offset;
882 struct blob_descriptor *final_blob;
883 size_t list_head_offset;
884 };
885
886 static struct blob_descriptor *
next_blob(struct blob_descriptor * blob,size_t list_head_offset)887 next_blob(struct blob_descriptor *blob, size_t list_head_offset)
888 {
889 struct list_head *cur;
890
891 cur = (struct list_head*)((u8*)blob + list_head_offset);
892
893 return (struct blob_descriptor*)((u8*)cur->next - list_head_offset);
894 }
895
896 /*
897 * A consume_chunk implementation that translates raw resource data into blobs,
898 * calling the begin_blob, continue_blob, and end_blob callbacks as appropriate.
899 */
900 static int
blobifier_cb(const void * chunk,size_t size,void * _ctx)901 blobifier_cb(const void *chunk, size_t size, void *_ctx)
902 {
903 struct blobifier_context *ctx = _ctx;
904 int ret;
905
906 wimlib_assert(ctx->cur_blob != NULL);
907 wimlib_assert(size <= ctx->cur_blob->size - ctx->cur_blob_offset);
908
909 if (ctx->cur_blob_offset == 0) {
910 /* Starting a new blob. */
911 ret = call_begin_blob(ctx->cur_blob, &ctx->cbs);
912 if (ret)
913 return ret;
914 }
915
916 ret = call_continue_blob(ctx->cur_blob, ctx->cur_blob_offset,
917 chunk, size, &ctx->cbs);
918 ctx->cur_blob_offset += size;
919 if (ret)
920 return ret;
921
922 if (ctx->cur_blob_offset == ctx->cur_blob->size) {
923 /* Finished reading all the data for a blob. */
924
925 ctx->cur_blob_offset = 0;
926
927 ret = call_end_blob(ctx->cur_blob, 0, &ctx->cbs);
928 if (ret)
929 return ret;
930
931 /* Advance to next blob. */
932 ctx->cur_blob = ctx->next_blob;
933 if (ctx->cur_blob != NULL) {
934 if (ctx->cur_blob != ctx->final_blob)
935 ctx->next_blob = next_blob(ctx->cur_blob,
936 ctx->list_head_offset);
937 else
938 ctx->next_blob = NULL;
939 }
940 }
941 return 0;
942 }
943
944 struct hasher_context {
945 SHA_CTX sha_ctx;
946 int flags;
947 struct read_blob_callbacks cbs;
948 };
949
950 /* Callback for starting to read a blob while calculating its SHA-1 message
951 * digest. */
952 static int
hasher_begin_blob(struct blob_descriptor * blob,void * _ctx)953 hasher_begin_blob(struct blob_descriptor *blob, void *_ctx)
954 {
955 struct hasher_context *ctx = _ctx;
956
957 sha1_init(&ctx->sha_ctx);
958
959 return call_begin_blob(blob, &ctx->cbs);
960 }
961
962 /*
963 * A continue_blob() implementation that continues calculating the SHA-1 message
964 * digest of the blob being read, then optionally passes the data on to another
965 * continue_blob() implementation. This allows checking the SHA-1 message
966 * digest of a blob being extracted, for example.
967 */
968 static int
hasher_continue_blob(const struct blob_descriptor * blob,u64 offset,const void * chunk,size_t size,void * _ctx)969 hasher_continue_blob(const struct blob_descriptor *blob, u64 offset,
970 const void *chunk, size_t size, void *_ctx)
971 {
972 struct hasher_context *ctx = _ctx;
973
974 sha1_update(&ctx->sha_ctx, chunk, size);
975
976 return call_continue_blob(blob, offset, chunk, size, &ctx->cbs);
977 }
978
979 static int
report_sha1_mismatch_error(const struct blob_descriptor * blob,const u8 actual_hash[SHA1_HASH_SIZE])980 report_sha1_mismatch_error(const struct blob_descriptor *blob,
981 const u8 actual_hash[SHA1_HASH_SIZE])
982 {
983 tchar expected_hashstr[SHA1_HASH_SIZE * 2 + 1];
984 tchar actual_hashstr[SHA1_HASH_SIZE * 2 + 1];
985
986 wimlib_assert(blob->blob_location != BLOB_NONEXISTENT);
987 wimlib_assert(blob->blob_location != BLOB_IN_ATTACHED_BUFFER);
988
989 sprint_hash(blob->hash, expected_hashstr);
990 sprint_hash(actual_hash, actual_hashstr);
991
992 if (blob_is_in_file(blob)) {
993 ERROR("A file was concurrently modified!\n"
994 " Path: \"%"TS"\"\n"
995 " Expected SHA-1: %"TS"\n"
996 " Actual SHA-1: %"TS"\n",
997 blob_file_path(blob), expected_hashstr, actual_hashstr);
998 return WIMLIB_ERR_CONCURRENT_MODIFICATION_DETECTED;
999 } else if (blob->blob_location == BLOB_IN_WIM) {
1000 const struct wim_resource_descriptor *rdesc = blob->rdesc;
1001 ERROR("A WIM resource is corrupted!\n"
1002 " WIM file: \"%"TS"\"\n"
1003 " Blob uncompressed size: %"PRIu64"\n"
1004 " Resource offset in WIM: %"PRIu64"\n"
1005 " Resource uncompressed size: %"PRIu64"\n"
1006 " Resource size in WIM: %"PRIu64"\n"
1007 " Resource flags: 0x%x%"TS"\n"
1008 " Resource compression type: %"TS"\n"
1009 " Resource compression chunk size: %"PRIu32"\n"
1010 " Expected SHA-1: %"TS"\n"
1011 " Actual SHA-1: %"TS"\n",
1012 rdesc->wim->filename,
1013 blob->size,
1014 rdesc->offset_in_wim,
1015 rdesc->uncompressed_size,
1016 rdesc->size_in_wim,
1017 (unsigned int)rdesc->flags,
1018 (rdesc->is_pipable ? T(", pipable") : T("")),
1019 wimlib_get_compression_type_string(
1020 rdesc->compression_type),
1021 rdesc->chunk_size,
1022 expected_hashstr, actual_hashstr);
1023 return WIMLIB_ERR_INVALID_RESOURCE_HASH;
1024 } else {
1025 ERROR("File data was concurrently modified!\n"
1026 " Location ID: %d\n"
1027 " Expected SHA-1: %"TS"\n"
1028 " Actual SHA-1: %"TS"\n",
1029 (int)blob->blob_location,
1030 expected_hashstr, actual_hashstr);
1031 return WIMLIB_ERR_CONCURRENT_MODIFICATION_DETECTED;
1032 }
1033 }
1034
1035 /* Callback for finishing reading a blob while calculating its SHA-1 message
1036 * digest. */
1037 static int
hasher_end_blob(struct blob_descriptor * blob,int status,void * _ctx)1038 hasher_end_blob(struct blob_descriptor *blob, int status, void *_ctx)
1039 {
1040 struct hasher_context *ctx = _ctx;
1041 u8 hash[SHA1_HASH_SIZE];
1042 int ret;
1043
1044 if (unlikely(status)) {
1045 /* Error occurred; the full blob may not have been read. */
1046 ret = status;
1047 goto out_next_cb;
1048 }
1049
1050 /* Retrieve the final SHA-1 message digest. */
1051 sha1_final(hash, &ctx->sha_ctx);
1052
1053 /* Set the SHA-1 message digest of the blob, or compare the calculated
1054 * value with stored value. */
1055 if (blob->unhashed) {
1056 if (ctx->flags & COMPUTE_MISSING_BLOB_HASHES)
1057 copy_hash(blob->hash, hash);
1058 } else if ((ctx->flags & VERIFY_BLOB_HASHES) &&
1059 unlikely(!hashes_equal(hash, blob->hash)))
1060 {
1061 ret = report_sha1_mismatch_error(blob, hash);
1062 goto out_next_cb;
1063 }
1064 ret = 0;
1065 out_next_cb:
1066 return call_end_blob(blob, ret, &ctx->cbs);
1067 }
1068
1069 /* Read the full data of the specified blob, passing the data into the specified
1070 * callbacks (all of which are optional) and either checking or computing the
1071 * SHA-1 message digest of the blob. */
1072 int
read_blob_with_sha1(struct blob_descriptor * blob,const struct read_blob_callbacks * cbs)1073 read_blob_with_sha1(struct blob_descriptor *blob,
1074 const struct read_blob_callbacks *cbs)
1075 {
1076 struct hasher_context hasher_ctx = {
1077 .flags = VERIFY_BLOB_HASHES | COMPUTE_MISSING_BLOB_HASHES,
1078 .cbs = *cbs,
1079 };
1080 struct read_blob_callbacks hasher_cbs = {
1081 .begin_blob = hasher_begin_blob,
1082 .continue_blob = hasher_continue_blob,
1083 .end_blob = hasher_end_blob,
1084 .ctx = &hasher_ctx,
1085 };
1086 return read_blob_with_cbs(blob, &hasher_cbs);
1087 }
1088
1089 static int
read_blobs_in_solid_resource(struct blob_descriptor * first_blob,struct blob_descriptor * last_blob,size_t blob_count,size_t list_head_offset,const struct read_blob_callbacks * sink_cbs)1090 read_blobs_in_solid_resource(struct blob_descriptor *first_blob,
1091 struct blob_descriptor *last_blob,
1092 size_t blob_count,
1093 size_t list_head_offset,
1094 const struct read_blob_callbacks *sink_cbs)
1095 {
1096 struct data_range *ranges;
1097 bool ranges_malloced;
1098 struct blob_descriptor *cur_blob;
1099 size_t i;
1100 int ret;
1101 u64 ranges_alloc_size;
1102
1103 /* Setup data ranges array (one range per blob to read); this way
1104 * read_compressed_wim_resource() does not need to be aware of blobs.
1105 */
1106
1107 ranges_alloc_size = (u64)blob_count * sizeof(ranges[0]);
1108
1109 if (unlikely((size_t)ranges_alloc_size != ranges_alloc_size))
1110 goto oom;
1111
1112 if (ranges_alloc_size <= STACK_MAX) {
1113 ranges = alloca(ranges_alloc_size);
1114 ranges_malloced = false;
1115 } else {
1116 ranges = MALLOC(ranges_alloc_size);
1117 if (unlikely(!ranges))
1118 goto oom;
1119 ranges_malloced = true;
1120 }
1121
1122 for (i = 0, cur_blob = first_blob;
1123 i < blob_count;
1124 i++, cur_blob = next_blob(cur_blob, list_head_offset))
1125 {
1126 ranges[i].offset = cur_blob->offset_in_res;
1127 ranges[i].size = cur_blob->size;
1128 }
1129
1130 struct blobifier_context blobifier_ctx = {
1131 .cbs = *sink_cbs,
1132 .cur_blob = first_blob,
1133 .next_blob = next_blob(first_blob, list_head_offset),
1134 .cur_blob_offset = 0,
1135 .final_blob = last_blob,
1136 .list_head_offset = list_head_offset,
1137 };
1138 struct consume_chunk_callback cb = {
1139 .func = blobifier_cb,
1140 .ctx = &blobifier_ctx,
1141 };
1142
1143 ret = read_compressed_wim_resource(first_blob->rdesc, ranges,
1144 blob_count, &cb);
1145
1146 if (ranges_malloced)
1147 FREE(ranges);
1148
1149 if (unlikely(ret && blobifier_ctx.cur_blob_offset != 0)) {
1150 ret = call_end_blob(blobifier_ctx.cur_blob, ret,
1151 &blobifier_ctx.cbs);
1152 }
1153 return ret;
1154
1155 oom:
1156 ERROR("Too many blobs in one resource!");
1157 return WIMLIB_ERR_NOMEM;
1158 }
1159
1160 /*
1161 * Read a list of blobs, each of which may be in any supported location (e.g.
1162 * in a WIM or in an external file). This function optimizes the case where
1163 * multiple blobs are combined into a single solid compressed WIM resource by
1164 * reading the blobs in sequential order, only decompressing the solid resource
1165 * one time.
1166 *
1167 * @blob_list
1168 * List of blobs to read.
1169 * @list_head_offset
1170 * Offset of the `struct list_head' within each `struct blob_descriptor'
1171 * that makes up the @blob_list.
1172 * @cbs
1173 * Callback functions to accept the blob data.
1174 * @flags
1175 * Bitwise OR of zero or more of the following flags:
1176 *
1177 * VERIFY_BLOB_HASHES:
1178 * For all blobs being read that have already had SHA-1 message
1179 * digests computed, calculate the SHA-1 message digest of the read
1180 * data and compare it with the previously computed value. If they
1181 * do not match, return WIMLIB_ERR_INVALID_RESOURCE_HASH.
1182 *
1183 * COMPUTE_MISSING_BLOB_HASHES
1184 * For all blobs being read that have not yet had their SHA-1
1185 * message digests computed, calculate and save their SHA-1 message
1186 * digests.
1187 *
1188 * BLOB_LIST_ALREADY_SORTED
1189 * @blob_list is already sorted in sequential order for reading.
1190 *
1191 * The callback functions are allowed to delete the current blob from the list
1192 * if necessary.
1193 *
1194 * Returns 0 on success; a nonzero error code on failure. Failure can occur due
1195 * to an error reading the data or due to an error status being returned by any
1196 * of the callback functions.
1197 */
1198 int
read_blob_list(struct list_head * blob_list,size_t list_head_offset,const struct read_blob_callbacks * cbs,int flags)1199 read_blob_list(struct list_head *blob_list, size_t list_head_offset,
1200 const struct read_blob_callbacks *cbs, int flags)
1201 {
1202 int ret;
1203 struct list_head *cur, *next;
1204 struct blob_descriptor *blob;
1205 struct hasher_context *hasher_ctx;
1206 struct read_blob_callbacks *sink_cbs;
1207
1208 if (!(flags & BLOB_LIST_ALREADY_SORTED)) {
1209 ret = sort_blob_list_by_sequential_order(blob_list,
1210 list_head_offset);
1211 if (ret)
1212 return ret;
1213 }
1214
1215 if (flags & (VERIFY_BLOB_HASHES | COMPUTE_MISSING_BLOB_HASHES)) {
1216 hasher_ctx = alloca(sizeof(*hasher_ctx));
1217 *hasher_ctx = (struct hasher_context) {
1218 .flags = flags,
1219 .cbs = *cbs,
1220 };
1221 sink_cbs = alloca(sizeof(*sink_cbs));
1222 *sink_cbs = (struct read_blob_callbacks) {
1223 .begin_blob = hasher_begin_blob,
1224 .continue_blob = hasher_continue_blob,
1225 .end_blob = hasher_end_blob,
1226 .ctx = hasher_ctx,
1227 };
1228 } else {
1229 sink_cbs = (struct read_blob_callbacks *)cbs;
1230 }
1231
1232 for (cur = blob_list->next, next = cur->next;
1233 cur != blob_list;
1234 cur = next, next = cur->next)
1235 {
1236 blob = (struct blob_descriptor*)((u8*)cur - list_head_offset);
1237
1238 if (blob->blob_location == BLOB_IN_WIM &&
1239 blob->size != blob->rdesc->uncompressed_size)
1240 {
1241 struct blob_descriptor *blob_next, *blob_last;
1242 struct list_head *next2;
1243 size_t blob_count;
1244
1245 /* The next blob is a proper sub-sequence of a WIM
1246 * resource. See if there are other blobs in the same
1247 * resource that need to be read. Since
1248 * sort_blob_list_by_sequential_order() sorted the blobs
1249 * by offset in the WIM, this can be determined by
1250 * simply scanning forward in the list. */
1251
1252 blob_last = blob;
1253 blob_count = 1;
1254 for (next2 = next;
1255 next2 != blob_list
1256 && (blob_next = (struct blob_descriptor*)
1257 ((u8*)next2 - list_head_offset),
1258 blob_next->blob_location == BLOB_IN_WIM
1259 && blob_next->rdesc == blob->rdesc);
1260 next2 = next2->next)
1261 {
1262 blob_last = blob_next;
1263 blob_count++;
1264 }
1265 if (blob_count > 1) {
1266 /* Reading multiple blobs combined into a single
1267 * WIM resource. They are in the blob list,
1268 * sorted by offset; @blob specifies the first
1269 * blob in the resource that needs to be read
1270 * and @blob_last specifies the last blob in the
1271 * resource that needs to be read. */
1272 next = next2;
1273 ret = read_blobs_in_solid_resource(blob, blob_last,
1274 blob_count,
1275 list_head_offset,
1276 sink_cbs);
1277 if (ret)
1278 return ret;
1279 continue;
1280 }
1281 }
1282
1283 ret = read_blob_with_cbs(blob, sink_cbs);
1284 if (unlikely(ret && ret != BEGIN_BLOB_STATUS_SKIP_BLOB))
1285 return ret;
1286 }
1287 return 0;
1288 }
1289
1290 static int
extract_chunk_to_fd(const void * chunk,size_t size,void * _fd)1291 extract_chunk_to_fd(const void *chunk, size_t size, void *_fd)
1292 {
1293 struct filedes *fd = _fd;
1294 int ret = full_write(fd, chunk, size);
1295 if (unlikely(ret))
1296 ERROR_WITH_ERRNO("Error writing to file descriptor");
1297 return ret;
1298 }
1299
1300 static int
extract_blob_chunk_to_fd(const struct blob_descriptor * blob,u64 offset,const void * chunk,size_t size,void * _fd)1301 extract_blob_chunk_to_fd(const struct blob_descriptor *blob, u64 offset,
1302 const void *chunk, size_t size, void *_fd)
1303 {
1304 return extract_chunk_to_fd(chunk, size, _fd);
1305 }
1306
1307 /* Extract the first @size bytes of the specified blob to the specified file
1308 * descriptor. This does *not* check the SHA-1 message digest. */
1309 int
extract_blob_prefix_to_fd(struct blob_descriptor * blob,u64 size,struct filedes * fd)1310 extract_blob_prefix_to_fd(struct blob_descriptor *blob, u64 size,
1311 struct filedes *fd)
1312 {
1313 struct consume_chunk_callback cb = {
1314 .func = extract_chunk_to_fd,
1315 .ctx = fd,
1316 };
1317 return read_blob_prefix(blob, size, &cb);
1318 }
1319
1320 /* Extract the full uncompressed contents of the specified blob to the specified
1321 * file descriptor. This checks the SHA-1 message digest. */
1322 int
extract_blob_to_fd(struct blob_descriptor * blob,struct filedes * fd)1323 extract_blob_to_fd(struct blob_descriptor *blob, struct filedes *fd)
1324 {
1325 struct read_blob_callbacks cbs = {
1326 .continue_blob = extract_blob_chunk_to_fd,
1327 .ctx = fd,
1328 };
1329 return read_blob_with_sha1(blob, &cbs);
1330 }
1331
1332 /* Calculate the SHA-1 message digest of a blob and store it in @blob->hash. */
1333 int
sha1_blob(struct blob_descriptor * blob)1334 sha1_blob(struct blob_descriptor *blob)
1335 {
1336 static const struct read_blob_callbacks cbs = {
1337 };
1338 return read_blob_with_sha1(blob, &cbs);
1339 }
1340
1341 /*
1342 * Convert a short WIM resource header to a stand-alone WIM resource descriptor.
1343 *
1344 * Note: for solid resources some fields still need to be overridden.
1345 */
1346 void
wim_reshdr_to_desc(const struct wim_reshdr * reshdr,WIMStruct * wim,struct wim_resource_descriptor * rdesc)1347 wim_reshdr_to_desc(const struct wim_reshdr *reshdr, WIMStruct *wim,
1348 struct wim_resource_descriptor *rdesc)
1349 {
1350 rdesc->wim = wim;
1351 rdesc->offset_in_wim = reshdr->offset_in_wim;
1352 rdesc->size_in_wim = reshdr->size_in_wim;
1353 rdesc->uncompressed_size = reshdr->uncompressed_size;
1354 INIT_LIST_HEAD(&rdesc->blob_list);
1355 rdesc->flags = reshdr->flags;
1356 rdesc->is_pipable = wim_is_pipable(wim);
1357 if (rdesc->flags & WIM_RESHDR_FLAG_COMPRESSED) {
1358 rdesc->compression_type = wim->compression_type;
1359 rdesc->chunk_size = wim->chunk_size;
1360 } else {
1361 rdesc->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
1362 rdesc->chunk_size = 0;
1363 }
1364 }
1365
1366 /*
1367 * Convert the short WIM resource header @reshdr to a stand-alone WIM resource
1368 * descriptor @rdesc, then set @blob to consist of that entire resource. This
1369 * should only be used for non-solid resources!
1370 */
1371 void
wim_reshdr_to_desc_and_blob(const struct wim_reshdr * reshdr,WIMStruct * wim,struct wim_resource_descriptor * rdesc,struct blob_descriptor * blob)1372 wim_reshdr_to_desc_and_blob(const struct wim_reshdr *reshdr, WIMStruct *wim,
1373 struct wim_resource_descriptor *rdesc,
1374 struct blob_descriptor *blob)
1375 {
1376 wim_reshdr_to_desc(reshdr, wim, rdesc);
1377 blob->size = rdesc->uncompressed_size;
1378 blob_set_is_located_in_wim_resource(blob, rdesc, 0);
1379 }
1380
1381 /* Import a WIM resource header from the on-disk format. */
1382 void
get_wim_reshdr(const struct wim_reshdr_disk * disk_reshdr,struct wim_reshdr * reshdr)1383 get_wim_reshdr(const struct wim_reshdr_disk *disk_reshdr,
1384 struct wim_reshdr *reshdr)
1385 {
1386 reshdr->offset_in_wim = le64_to_cpu(disk_reshdr->offset_in_wim);
1387 reshdr->size_in_wim = (((u64)disk_reshdr->size_in_wim[0] << 0) |
1388 ((u64)disk_reshdr->size_in_wim[1] << 8) |
1389 ((u64)disk_reshdr->size_in_wim[2] << 16) |
1390 ((u64)disk_reshdr->size_in_wim[3] << 24) |
1391 ((u64)disk_reshdr->size_in_wim[4] << 32) |
1392 ((u64)disk_reshdr->size_in_wim[5] << 40) |
1393 ((u64)disk_reshdr->size_in_wim[6] << 48));
1394 reshdr->uncompressed_size = le64_to_cpu(disk_reshdr->uncompressed_size);
1395 reshdr->flags = disk_reshdr->flags;
1396 }
1397
1398 /* Export a WIM resource header to the on-disk format. */
1399 void
put_wim_reshdr(const struct wim_reshdr * reshdr,struct wim_reshdr_disk * disk_reshdr)1400 put_wim_reshdr(const struct wim_reshdr *reshdr,
1401 struct wim_reshdr_disk *disk_reshdr)
1402 {
1403 disk_reshdr->size_in_wim[0] = reshdr->size_in_wim >> 0;
1404 disk_reshdr->size_in_wim[1] = reshdr->size_in_wim >> 8;
1405 disk_reshdr->size_in_wim[2] = reshdr->size_in_wim >> 16;
1406 disk_reshdr->size_in_wim[3] = reshdr->size_in_wim >> 24;
1407 disk_reshdr->size_in_wim[4] = reshdr->size_in_wim >> 32;
1408 disk_reshdr->size_in_wim[5] = reshdr->size_in_wim >> 40;
1409 disk_reshdr->size_in_wim[6] = reshdr->size_in_wim >> 48;
1410 disk_reshdr->flags = reshdr->flags;
1411 disk_reshdr->offset_in_wim = cpu_to_le64(reshdr->offset_in_wim);
1412 disk_reshdr->uncompressed_size = cpu_to_le64(reshdr->uncompressed_size);
1413 }
1414