4f1c54a00df805cef6ff092e009ec32bc35e603a
[wimlib] / src / extract.c
1 /*
2  * extract.c
3  *
4  * Support for extracting WIM images, or files or directories contained in a WIM
5  * image.
6  */
7
8 /*
9  * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
10  *
11  * This file is free software; you can redistribute it and/or modify it under
12  * the terms of the GNU Lesser General Public License as published by the Free
13  * Software Foundation; either version 3 of the License, or (at your option) any
14  * later version.
15  *
16  * This file is distributed in the hope that it will be useful, but WITHOUT
17  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
18  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
19  * details.
20  *
21  * You should have received a copy of the GNU Lesser General Public License
22  * along with this file; if not, see http://www.gnu.org/licenses/.
23  */
24
25 /*
26  * This file provides the API functions wimlib_extract_image(),
27  * wimlib_extract_image_from_pipe(), wimlib_extract_paths(), and
28  * wimlib_extract_pathlist().  Internally, all end up calling
29  * do_wimlib_extract_paths() and extract_trees().
30  *
31  * Although wimlib supports multiple extraction modes/backends (NTFS-3g, UNIX,
32  * Win32), this file does not itself have code to extract files or directories
33  * to any specific target; instead, it handles generic functionality and relies
34  * on lower-level callback functions declared in `struct apply_operations' to do
35  * the actual extraction.
36  */
37
38 #ifdef HAVE_CONFIG_H
39 #  include "config.h"
40 #endif
41
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <sys/stat.h>
45 #include <unistd.h>
46
47 #include "wimlib/apply.h"
48 #include "wimlib/assert.h"
49 #include "wimlib/blob_table.h"
50 #include "wimlib/dentry.h"
51 #include "wimlib/encoding.h"
52 #include "wimlib/endianness.h"
53 #include "wimlib/error.h"
54 #include "wimlib/metadata.h"
55 #include "wimlib/pathlist.h"
56 #include "wimlib/paths.h"
57 #include "wimlib/pattern.h"
58 #include "wimlib/reparse.h"
59 #include "wimlib/resource.h"
60 #include "wimlib/security.h"
61 #include "wimlib/unix_data.h"
62 #include "wimlib/wim.h"
63 #include "wimlib/win32.h" /* for realpath() equivalent */
64 #include "wimlib/xml.h"
65
66 #define WIMLIB_EXTRACT_FLAG_FROM_PIPE   0x80000000
67 #define WIMLIB_EXTRACT_FLAG_IMAGEMODE   0x40000000
68
69 /* Keep in sync with wimlib.h  */
70 #define WIMLIB_EXTRACT_MASK_PUBLIC                              \
71         (WIMLIB_EXTRACT_FLAG_NTFS                       |       \
72          WIMLIB_EXTRACT_FLAG_UNIX_DATA                  |       \
73          WIMLIB_EXTRACT_FLAG_NO_ACLS                    |       \
74          WIMLIB_EXTRACT_FLAG_STRICT_ACLS                |       \
75          WIMLIB_EXTRACT_FLAG_RPFIX                      |       \
76          WIMLIB_EXTRACT_FLAG_NORPFIX                    |       \
77          WIMLIB_EXTRACT_FLAG_TO_STDOUT                  |       \
78          WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES  |       \
79          WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS         |       \
80          WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS          |       \
81          WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES         |       \
82          WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS            |       \
83          WIMLIB_EXTRACT_FLAG_GLOB_PATHS                 |       \
84          WIMLIB_EXTRACT_FLAG_STRICT_GLOB                |       \
85          WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES              |       \
86          WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE  |       \
87          WIMLIB_EXTRACT_FLAG_WIMBOOT)
88
89 /* Send WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE or
90  * WIMLIB_PROGRESS_MSG_EXTRACT_METADATA.  */
91 int
92 do_file_extract_progress(struct apply_ctx *ctx, enum wimlib_progress_msg msg)
93 {
94         ctx->count_until_file_progress = 500;  /* Arbitrary value to limit calls  */
95         return extract_progress(ctx, msg);
96 }
97
98 static int
99 start_file_phase(struct apply_ctx *ctx, u64 end_file_count, enum wimlib_progress_msg msg)
100 {
101         ctx->progress.extract.current_file_count = 0;
102         ctx->progress.extract.end_file_count = end_file_count;
103         return do_file_extract_progress(ctx, msg);
104 }
105
106 int
107 start_file_structure_phase(struct apply_ctx *ctx, u64 end_file_count)
108 {
109         return start_file_phase(ctx, end_file_count, WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE);
110 }
111
112 int
113 start_file_metadata_phase(struct apply_ctx *ctx, u64 end_file_count)
114 {
115         return start_file_phase(ctx, end_file_count, WIMLIB_PROGRESS_MSG_EXTRACT_METADATA);
116 }
117
118 static int
119 end_file_phase(struct apply_ctx *ctx, enum wimlib_progress_msg msg)
120 {
121         ctx->progress.extract.current_file_count = ctx->progress.extract.end_file_count;
122         return do_file_extract_progress(ctx, msg);
123 }
124
125 int
126 end_file_structure_phase(struct apply_ctx *ctx)
127 {
128         return end_file_phase(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE);
129 }
130
131 int
132 end_file_metadata_phase(struct apply_ctx *ctx)
133 {
134         return end_file_phase(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_METADATA);
135 }
136
137 #define PWM_FOUND_WIM_HDR (-1)
138
139 /* Read the header for a blob in a pipable WIM.  If @pwm_hdr_ret is not NULL,
140  * also look for a pipable WIM header and return PWM_FOUND_WIM_HDR if found.  */
141 static int
142 read_pwm_blob_header(WIMStruct *pwm, u8 hash_ret[SHA1_HASH_SIZE],
143                      struct wim_reshdr *reshdr_ret,
144                      struct wim_header_disk *pwm_hdr_ret)
145 {
146         int ret;
147         struct pwm_blob_hdr blob_hdr;
148         u64 magic;
149
150         ret = full_read(&pwm->in_fd, &blob_hdr, sizeof(blob_hdr));
151         if (unlikely(ret))
152                 goto read_error;
153
154         magic = le64_to_cpu(blob_hdr.magic);
155
156         if (magic == PWM_MAGIC && pwm_hdr_ret != NULL) {
157                 memcpy(pwm_hdr_ret, &blob_hdr, sizeof(blob_hdr));
158                 ret = full_read(&pwm->in_fd,
159                                 (u8 *)pwm_hdr_ret + sizeof(blob_hdr),
160                                 sizeof(*pwm_hdr_ret) - sizeof(blob_hdr));
161                 if (unlikely(ret))
162                         goto read_error;
163                 return PWM_FOUND_WIM_HDR;
164         }
165
166         if (unlikely(magic != PWM_BLOB_MAGIC)) {
167                 ERROR("Data read on pipe is invalid (expected blob header)");
168                 return WIMLIB_ERR_INVALID_PIPABLE_WIM;
169         }
170
171         copy_hash(hash_ret, blob_hdr.hash);
172
173         reshdr_ret->size_in_wim = 0; /* Not available  */
174         reshdr_ret->flags = le32_to_cpu(blob_hdr.flags);
175         reshdr_ret->offset_in_wim = pwm->in_fd.offset;
176         reshdr_ret->uncompressed_size = le64_to_cpu(blob_hdr.uncompressed_size);
177
178         if (unlikely(reshdr_ret->uncompressed_size == 0)) {
179                 ERROR("Data read on pipe is invalid (resource is of 0 size)");
180                 return WIMLIB_ERR_INVALID_PIPABLE_WIM;
181         }
182
183         return 0;
184
185 read_error:
186         if (ret == WIMLIB_ERR_UNEXPECTED_END_OF_FILE)
187                 ERROR("The pipe ended before all needed data was sent!");
188         else
189                 ERROR_WITH_ERRNO("Error reading pipable WIM from pipe");
190         return ret;
191 }
192
193 static int
194 read_blobs_from_pipe(struct apply_ctx *ctx, const struct read_blob_callbacks *cbs)
195 {
196         int ret;
197         u8 hash[SHA1_HASH_SIZE];
198         struct wim_reshdr reshdr;
199         struct wim_header_disk pwm_hdr;
200         struct wim_resource_descriptor rdesc;
201         struct blob_descriptor *blob;
202
203         copy_guid(ctx->progress.extract.guid, ctx->wim->hdr.guid);
204         ctx->progress.extract.part_number = ctx->wim->hdr.part_number;
205         ctx->progress.extract.total_parts = ctx->wim->hdr.total_parts;
206         ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN);
207         if (ret)
208                 return ret;
209
210         while (ctx->num_blobs_remaining) {
211
212                 ret = read_pwm_blob_header(ctx->wim, hash, &reshdr, &pwm_hdr);
213
214                 if (ret == PWM_FOUND_WIM_HDR) {
215                         u16 part_number = le16_to_cpu(pwm_hdr.part_number);
216                         u16 total_parts = le16_to_cpu(pwm_hdr.total_parts);
217
218                         if (part_number == ctx->progress.extract.part_number &&
219                             total_parts == ctx->progress.extract.total_parts &&
220                             guids_equal(pwm_hdr.guid, ctx->progress.extract.guid))
221                                 continue;
222
223                         copy_guid(ctx->progress.extract.guid, pwm_hdr.guid);
224                         ctx->progress.extract.part_number = part_number;
225                         ctx->progress.extract.total_parts = total_parts;
226                         ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN);
227                         if (ret)
228                                 return ret;
229
230                         continue;
231                 }
232
233                 if (ret)
234                         return ret;
235
236                 if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)
237                     && (blob = lookup_blob(ctx->wim->blob_table, hash))
238                     && (blob->out_refcnt))
239                 {
240                         wim_reshdr_to_desc_and_blob(&reshdr, ctx->wim, &rdesc, blob);
241                         ret = read_blob_with_sha1(blob, cbs);
242                         blob_unset_is_located_in_wim_resource(blob);
243                         if (ret)
244                                 return ret;
245                         ctx->num_blobs_remaining--;
246                 } else {
247                         wim_reshdr_to_desc(&reshdr, ctx->wim, &rdesc);
248                         ret = skip_wim_resource(&rdesc);
249                         if (ret)
250                                 return ret;
251                 }
252         }
253
254         return 0;
255 }
256
257 /* Creates a temporary file opened for writing.  The open file descriptor is
258  * returned in @fd_ret and its name is returned in @name_ret (dynamically
259  * allocated).  */
260 static int
261 create_temporary_file(struct filedes *fd_ret, tchar **name_ret)
262 {
263         tchar *name;
264         int open_flags;
265         int raw_fd;
266
267 retry:
268         name = ttempnam(NULL, T("wimlib"));
269         if (!name) {
270                 ERROR_WITH_ERRNO("Failed to create temporary filename");
271                 return WIMLIB_ERR_NOMEM;
272         }
273
274         open_flags = O_WRONLY | O_CREAT | O_EXCL | O_BINARY;
275 #ifdef __WIN32__
276         open_flags |= _O_SHORT_LIVED;
277 #endif
278         raw_fd = topen(name, open_flags, 0600);
279
280         if (raw_fd < 0) {
281                 if (errno == EEXIST) {
282                         FREE(name);
283                         goto retry;
284                 }
285                 ERROR_WITH_ERRNO("Failed to create temporary file "
286                                  "\"%"TS"\"", name);
287                 FREE(name);
288                 return WIMLIB_ERR_OPEN;
289         }
290
291         filedes_init(fd_ret, raw_fd);
292         *name_ret = name;
293         return 0;
294 }
295
296 static int
297 begin_extract_blob_wrapper(struct blob_descriptor *blob, void *_ctx)
298 {
299         struct apply_ctx *ctx = _ctx;
300
301         ctx->cur_blob = blob;
302         ctx->cur_blob_offset = 0;
303
304         if (unlikely(blob->out_refcnt > MAX_OPEN_FILES))
305                 return create_temporary_file(&ctx->tmpfile_fd, &ctx->tmpfile_name);
306
307         return call_begin_blob(blob, ctx->saved_cbs);
308 }
309
310 static int
311 extract_chunk_wrapper(const void *chunk, size_t size, void *_ctx)
312 {
313         struct apply_ctx *ctx = _ctx;
314         union wimlib_progress_info *progress = &ctx->progress;
315         int ret;
316
317         ctx->cur_blob_offset += size;
318
319         if (likely(ctx->supported_features.hard_links)) {
320                 progress->extract.completed_bytes +=
321                         (u64)size * ctx->cur_blob->out_refcnt;
322                 if (ctx->cur_blob_offset == ctx->cur_blob->size)
323                         progress->extract.completed_streams += ctx->cur_blob->out_refcnt;
324         } else {
325                 const struct blob_extraction_target *targets =
326                         blob_extraction_targets(ctx->cur_blob);
327                 for (u32 i = 0; i < ctx->cur_blob->out_refcnt; i++) {
328                         const struct wim_inode *inode = targets[i].inode;
329                         const struct wim_dentry *dentry;
330
331                         inode_for_each_extraction_alias(dentry, inode) {
332                                 progress->extract.completed_bytes += size;
333                                 if (ctx->cur_blob_offset == ctx->cur_blob->size)
334                                         progress->extract.completed_streams++;
335                         }
336                 }
337         }
338         if (progress->extract.completed_bytes >= ctx->next_progress) {
339
340                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
341                 if (ret)
342                         return ret;
343
344                 set_next_progress(progress->extract.completed_bytes,
345                                   progress->extract.total_bytes,
346                                   &ctx->next_progress);
347         }
348
349         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
350                 /* Just extracting to temporary file for now.  */
351                 ret = full_write(&ctx->tmpfile_fd, chunk, size);
352                 if (ret) {
353                         ERROR_WITH_ERRNO("Error writing data to "
354                                          "temporary file \"%"TS"\"",
355                                          ctx->tmpfile_name);
356                 }
357                 return ret;
358         }
359
360         return call_consume_chunk(chunk, size, ctx->saved_cbs);
361 }
362
363 /* Copy the blob's data from the temporary file to each of its targets.
364  *
365  * This is executed only in the very uncommon case that a blob is being
366  * extracted to more than MAX_OPEN_FILES targets!  */
367 static int
368 extract_from_tmpfile(const tchar *tmpfile_name,
369                      const struct blob_descriptor *orig_blob,
370                      const struct read_blob_callbacks *cbs)
371 {
372         struct blob_descriptor tmpfile_blob;
373         const struct blob_extraction_target *targets = blob_extraction_targets(orig_blob);
374         int ret;
375
376         memcpy(&tmpfile_blob, orig_blob, sizeof(struct blob_descriptor));
377         tmpfile_blob.blob_location = BLOB_IN_FILE_ON_DISK;
378         tmpfile_blob.file_on_disk = (tchar *)tmpfile_name;
379         tmpfile_blob.out_refcnt = 1;
380
381         for (u32 i = 0; i < orig_blob->out_refcnt; i++) {
382                 tmpfile_blob.inline_blob_extraction_targets[0] = targets[i];
383                 ret = read_blob_with_cbs(&tmpfile_blob, cbs);
384                 if (ret)
385                         return ret;
386         }
387         return 0;
388 }
389
390 static int
391 end_extract_blob_wrapper(struct blob_descriptor *blob, int status, void *_ctx)
392 {
393         struct apply_ctx *ctx = _ctx;
394
395         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
396                 filedes_close(&ctx->tmpfile_fd);
397                 if (!status)
398                         status = extract_from_tmpfile(ctx->tmpfile_name, blob,
399                                                       ctx->saved_cbs);
400                 filedes_invalidate(&ctx->tmpfile_fd);
401                 tunlink(ctx->tmpfile_name);
402                 FREE(ctx->tmpfile_name);
403                 return status;
404         }
405
406         return call_end_blob(blob, status, ctx->saved_cbs);
407 }
408
409 /*
410  * Read the list of blobs to extract and feed their data into the specified
411  * callback functions.
412  *
413  * This handles checksumming each blob.
414  *
415  * This also handles sending WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS.
416  *
417  * This also works if the WIM is being read from a pipe.
418  *
419  * This also will split up blobs that will need to be extracted to more than
420  * MAX_OPEN_FILES locations, as measured by the 'out_refcnt' of each blob.
421  * Therefore, the apply_operations implementation need not worry about running
422  * out of file descriptors, unless it might open more than one file descriptor
423  * per 'blob_extraction_target' (e.g. Win32 currently might because the
424  * destination file system might not support hard links).
425  */
426 int
427 extract_blob_list(struct apply_ctx *ctx, const struct read_blob_callbacks *cbs)
428 {
429         struct read_blob_callbacks wrapper_cbs = {
430                 .begin_blob     = begin_extract_blob_wrapper,
431                 .consume_chunk  = extract_chunk_wrapper,
432                 .end_blob       = end_extract_blob_wrapper,
433                 .ctx            = ctx,
434         };
435         ctx->saved_cbs = cbs;
436         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
437                 return read_blobs_from_pipe(ctx, &wrapper_cbs);
438         } else {
439                 return read_blob_list(&ctx->blob_list,
440                                       offsetof(struct blob_descriptor,
441                                                extraction_list),
442                                       &wrapper_cbs, VERIFY_BLOB_HASHES);
443         }
444 }
445
446 /* Extract a WIM dentry to standard output.
447  *
448  * This obviously doesn't make sense in all cases.  We return an error if the
449  * dentry does not correspond to a regular file.  Otherwise we extract the
450  * unnamed data stream only.  */
451 static int
452 extract_dentry_to_stdout(struct wim_dentry *dentry,
453                          const struct blob_table *blob_table)
454 {
455         struct wim_inode *inode = dentry->d_inode;
456         struct blob_descriptor *blob;
457         struct filedes _stdout;
458
459         if (inode->i_attributes & (FILE_ATTRIBUTE_REPARSE_POINT |
460                                    FILE_ATTRIBUTE_DIRECTORY |
461                                    FILE_ATTRIBUTE_ENCRYPTED))
462         {
463                 ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
464                       "extracted to standard output", dentry_full_path(dentry));
465                 return WIMLIB_ERR_NOT_A_REGULAR_FILE;
466         }
467
468         blob = inode_get_blob_for_unnamed_data_stream(inode, blob_table);
469         if (!blob) {
470                 const u8 *hash = inode_get_hash_of_unnamed_data_stream(inode);
471                 if (!is_zero_hash(hash))
472                         return blob_not_found_error(inode, hash);
473                 return 0;
474         }
475
476         filedes_init(&_stdout, STDOUT_FILENO);
477         return extract_blob_to_fd(blob, &_stdout);
478 }
479
480 static int
481 extract_dentries_to_stdout(struct wim_dentry **dentries, size_t num_dentries,
482                            const struct blob_table *blob_table)
483 {
484         for (size_t i = 0; i < num_dentries; i++) {
485                 int ret = extract_dentry_to_stdout(dentries[i], blob_table);
486                 if (ret)
487                         return ret;
488         }
489         return 0;
490 }
491
492 /**********************************************************************/
493
494 /*
495  * Removes duplicate dentries from the array.
496  *
497  * Returns the new number of dentries, packed at the front of the array.
498  */
499 static size_t
500 remove_duplicate_trees(struct wim_dentry **trees, size_t num_trees)
501 {
502         size_t i, j = 0;
503         for (i = 0; i < num_trees; i++) {
504                 if (!trees[i]->d_tmp_flag) {
505                         /* Found distinct dentry.  */
506                         trees[i]->d_tmp_flag = 1;
507                         trees[j++] = trees[i];
508                 }
509         }
510         for (i = 0; i < j; i++)
511                 trees[i]->d_tmp_flag = 0;
512         return j;
513 }
514
515 /*
516  * Remove dentries that are descendants of other dentries in the array.
517  *
518  * Returns the new number of dentries, packed at the front of the array.
519  */
520 static size_t
521 remove_contained_trees(struct wim_dentry **trees, size_t num_trees)
522 {
523         size_t i, j = 0;
524         for (i = 0; i < num_trees; i++)
525                 trees[i]->d_tmp_flag = 1;
526         for (i = 0; i < num_trees; i++) {
527                 struct wim_dentry *d = trees[i];
528                 while (!dentry_is_root(d)) {
529                         d = d->d_parent;
530                         if (d->d_tmp_flag)
531                                 goto tree_contained;
532                 }
533                 trees[j++] = trees[i];
534                 continue;
535
536         tree_contained:
537                 trees[i]->d_tmp_flag = 0;
538         }
539
540         for (i = 0; i < j; i++)
541                 trees[i]->d_tmp_flag = 0;
542         return j;
543 }
544
545 static int
546 dentry_append_to_list(struct wim_dentry *dentry, void *_dentry_list)
547 {
548         struct list_head *dentry_list = _dentry_list;
549         list_add_tail(&dentry->d_extraction_list_node, dentry_list);
550         return 0;
551 }
552
553 static void
554 dentry_reset_extraction_list_node(struct wim_dentry *dentry)
555 {
556         dentry->d_extraction_list_node = (struct list_head){NULL, NULL};
557 }
558
559 static int
560 dentry_delete_from_list(struct wim_dentry *dentry, void *_ignore)
561 {
562         if (will_extract_dentry(dentry)) {
563                 list_del(&dentry->d_extraction_list_node);
564                 dentry_reset_extraction_list_node(dentry);
565         }
566         return 0;
567 }
568
569 /*
570  * Build the preliminary list of dentries to be extracted.
571  *
572  * The list maintains the invariant that if d1 and d2 are in the list and d1 is
573  * an ancestor of d2, then d1 appears before d2 in the list.
574  */
575 static void
576 build_dentry_list(struct list_head *dentry_list, struct wim_dentry **trees,
577                   size_t num_trees, bool add_ancestors)
578 {
579         INIT_LIST_HEAD(dentry_list);
580
581         /* Add the trees recursively.  */
582         for (size_t i = 0; i < num_trees; i++)
583                 for_dentry_in_tree(trees[i], dentry_append_to_list, dentry_list);
584
585         /* If requested, add ancestors of the trees.  */
586         if (add_ancestors) {
587                 for (size_t i = 0; i < num_trees; i++) {
588                         struct wim_dentry *dentry = trees[i];
589                         struct wim_dentry *ancestor;
590                         struct list_head *place_after;
591
592                         if (dentry_is_root(dentry))
593                                 continue;
594
595                         place_after = dentry_list;
596                         ancestor = dentry;
597                         do {
598                                 ancestor = ancestor->d_parent;
599                                 if (will_extract_dentry(ancestor)) {
600                                         place_after = &ancestor->d_extraction_list_node;
601                                         break;
602                                 }
603                         } while (!dentry_is_root(ancestor));
604
605                         ancestor = dentry;
606                         do {
607                                 ancestor = ancestor->d_parent;
608                                 if (will_extract_dentry(ancestor))
609                                         break;
610                                 list_add(&ancestor->d_extraction_list_node, place_after);
611                         } while (!dentry_is_root(ancestor));
612                 }
613         }
614 }
615
616 static void
617 destroy_dentry_list(struct list_head *dentry_list)
618 {
619         struct wim_dentry *dentry, *tmp;
620         struct wim_inode *inode;
621
622         list_for_each_entry_safe(dentry, tmp, dentry_list, d_extraction_list_node) {
623                 inode = dentry->d_inode;
624                 dentry_reset_extraction_list_node(dentry);
625                 inode->i_visited = 0;
626                 inode->i_can_externally_back = 0;
627                 if ((void *)dentry->d_extraction_name != (void *)dentry->d_name)
628                         FREE(dentry->d_extraction_name);
629                 dentry->d_extraction_name = NULL;
630                 dentry->d_extraction_name_nchars = 0;
631         }
632 }
633
634 static void
635 destroy_blob_list(struct list_head *blob_list)
636 {
637         struct blob_descriptor *blob;
638
639         list_for_each_entry(blob, blob_list, extraction_list)
640                 if (blob->out_refcnt > ARRAY_LEN(blob->inline_blob_extraction_targets))
641                         FREE(blob->blob_extraction_targets);
642 }
643
644 #ifdef __WIN32__
645 static const utf16lechar replacement_char = cpu_to_le16(0xfffd);
646 #else
647 static const utf16lechar replacement_char = cpu_to_le16('?');
648 #endif
649
650 static bool
651 file_name_valid(utf16lechar *name, size_t num_chars, bool fix)
652 {
653         size_t i;
654
655         if (num_chars == 0)
656                 return true;
657         for (i = 0; i < num_chars; i++) {
658                 switch (le16_to_cpu(name[i])) {
659         #ifdef __WIN32__
660                 case '\x01'...'\x1F':
661                 case '\\':
662                 case ':':
663                 case '*':
664                 case '?':
665                 case '"':
666                 case '<':
667                 case '>':
668                 case '|':
669         #endif
670                 case '/':
671                 case '\0':
672                         if (fix)
673                                 name[i] = replacement_char;
674                         else
675                                 return false;
676                 }
677         }
678
679         return true;
680 }
681
682 static int
683 dentry_calculate_extraction_name(struct wim_dentry *dentry,
684                                  struct apply_ctx *ctx)
685 {
686         int ret;
687
688         if (dentry_is_root(dentry))
689                 return 0;
690
691 #ifdef WITH_NTFS_3G
692         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
693                 dentry->d_extraction_name = dentry->d_name;
694                 dentry->d_extraction_name_nchars = dentry->d_name_nbytes /
695                                                    sizeof(utf16lechar);
696                 return 0;
697         }
698 #endif
699
700         if (!ctx->supported_features.case_sensitive_filenames) {
701                 struct wim_dentry *other;
702                 list_for_each_entry(other, &dentry->d_ci_conflict_list,
703                                     d_ci_conflict_list)
704                 {
705                         if (will_extract_dentry(other)) {
706                                 if (ctx->extract_flags &
707                                     WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS) {
708                                         WARNING("\"%"TS"\" has the same "
709                                                 "case-insensitive name as "
710                                                 "\"%"TS"\"; extracting "
711                                                 "dummy name instead",
712                                                 dentry_full_path(dentry),
713                                                 dentry_full_path(other));
714                                         goto out_replace;
715                                 } else {
716                                         WARNING("Not extracting \"%"TS"\": "
717                                                 "has same case-insensitive "
718                                                 "name as \"%"TS"\"",
719                                                 dentry_full_path(dentry),
720                                                 dentry_full_path(other));
721                                         goto skip_dentry;
722                                 }
723                         }
724                 }
725         }
726
727         if (file_name_valid(dentry->d_name, dentry->d_name_nbytes / 2, false)) {
728                 size_t nbytes = 0;
729                 ret = utf16le_get_tstr(dentry->d_name,
730                                        dentry->d_name_nbytes,
731                                        (const tchar **)&dentry->d_extraction_name,
732                                        &nbytes);
733                 dentry->d_extraction_name_nchars = nbytes / sizeof(tchar);
734                 return ret;
735         } else {
736                 if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
737                 {
738                         WARNING("\"%"TS"\" has an invalid filename "
739                                 "that is not supported on this platform; "
740                                 "extracting dummy name instead",
741                                 dentry_full_path(dentry));
742                         goto out_replace;
743                 } else {
744                         WARNING("Not extracting \"%"TS"\": has an invalid filename "
745                                 "that is not supported on this platform",
746                                 dentry_full_path(dentry));
747                         goto skip_dentry;
748                 }
749         }
750
751 out_replace:
752         {
753                 utf16lechar utf16_name_copy[dentry->d_name_nbytes / 2];
754
755                 memcpy(utf16_name_copy, dentry->d_name, dentry->d_name_nbytes);
756                 file_name_valid(utf16_name_copy, dentry->d_name_nbytes / 2, true);
757
758                 const tchar *tchar_name;
759                 size_t tchar_nchars;
760
761                 ret = utf16le_get_tstr(utf16_name_copy,
762                                        dentry->d_name_nbytes,
763                                        &tchar_name, &tchar_nchars);
764                 if (ret)
765                         return ret;
766
767                 tchar_nchars /= sizeof(tchar);
768
769                 size_t fixed_name_num_chars = tchar_nchars;
770                 tchar fixed_name[tchar_nchars + 50];
771
772                 tmemcpy(fixed_name, tchar_name, tchar_nchars);
773                 fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
774                                                  T(" (invalid filename #%lu)"),
775                                                  ++ctx->invalid_sequence);
776
777                 utf16le_put_tstr(tchar_name);
778
779                 dentry->d_extraction_name = TSTRDUP(fixed_name);
780                 if (!dentry->d_extraction_name)
781                         return WIMLIB_ERR_NOMEM;
782                 dentry->d_extraction_name_nchars = fixed_name_num_chars;
783         }
784         return 0;
785
786 skip_dentry:
787         for_dentry_in_tree(dentry, dentry_delete_from_list, NULL);
788         return 0;
789 }
790
791 /*
792  * Calculate the actual filename component at which each WIM dentry will be
793  * extracted, with special handling for dentries that are unsupported by the
794  * extraction backend or have invalid names.
795  *
796  * ctx->supported_features must be filled in.
797  *
798  * Possible error codes: WIMLIB_ERR_NOMEM, WIMLIB_ERR_INVALID_UTF16_STRING
799  */
800 static int
801 dentry_list_calculate_extraction_names(struct list_head *dentry_list,
802                                        struct apply_ctx *ctx)
803 {
804         struct list_head *prev, *cur;
805
806         /* Can't use list_for_each_entry() because a call to
807          * dentry_calculate_extraction_name() may delete the current dentry and
808          * its children from the list.  */
809
810         prev = dentry_list;
811         for (;;) {
812                 struct wim_dentry *dentry;
813                 int ret;
814
815                 cur = prev->next;
816                 if (cur == dentry_list)
817                         break;
818
819                 dentry = list_entry(cur, struct wim_dentry, d_extraction_list_node);
820
821                 ret = dentry_calculate_extraction_name(dentry, ctx);
822                 if (ret)
823                         return ret;
824
825                 if (prev->next == cur)
826                         prev = cur;
827                 else
828                         ; /* Current dentry and its children (which follow in
829                              the list) were deleted.  prev stays the same.  */
830         }
831         return 0;
832 }
833
834 static int
835 dentry_resolve_streams(struct wim_dentry *dentry, int extract_flags,
836                        struct blob_table *blob_table)
837 {
838         struct wim_inode *inode = dentry->d_inode;
839         struct blob_descriptor *blob;
840         int ret;
841         bool force = false;
842
843         /* Special case:  when extracting from a pipe, the WIM blob table is
844          * initially empty, so "resolving" an inode's streams is initially not
845          * possible.  However, we still need to keep track of which blobs,
846          * identified by SHA-1 message digests, need to be extracted, so we
847          * "resolve" the inode's streams anyway by allocating a 'struct
848          * blob_descriptor' for each one.  */
849         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
850                 force = true;
851         ret = inode_resolve_streams(inode, blob_table, force);
852         if (ret)
853                 return ret;
854         for (unsigned i = 0; i < inode->i_num_streams; i++) {
855                 blob = stream_blob_resolved(&inode->i_streams[i]);
856                 if (blob)
857                         blob->out_refcnt = 0;
858         }
859         return 0;
860 }
861
862 /*
863  * For each dentry to be extracted, resolve all streams in the corresponding
864  * inode and set 'out_refcnt' in all referenced blob_descriptors to 0.
865  *
866  * Possible error codes: WIMLIB_ERR_RESOURCE_NOT_FOUND, WIMLIB_ERR_NOMEM.
867  */
868 static int
869 dentry_list_resolve_streams(struct list_head *dentry_list,
870                             struct apply_ctx *ctx)
871 {
872         struct wim_dentry *dentry;
873         int ret;
874
875         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
876                 ret = dentry_resolve_streams(dentry,
877                                              ctx->extract_flags,
878                                              ctx->wim->blob_table);
879                 if (ret)
880                         return ret;
881         }
882         return 0;
883 }
884
885 static int
886 ref_stream(struct wim_inode_stream *strm, struct wim_dentry *dentry,
887            struct apply_ctx *ctx)
888 {
889         struct wim_inode *inode = dentry->d_inode;
890         struct blob_descriptor *blob = stream_blob_resolved(strm);
891         struct blob_extraction_target *targets;
892
893         if (!blob)
894                 return 0;
895
896         /* Tally the size only for each actual extraction of the stream (not
897          * additional hard links to the inode).  */
898         if (inode->i_visited && ctx->supported_features.hard_links)
899                 return 0;
900
901         ctx->progress.extract.total_bytes += blob->size;
902         ctx->progress.extract.total_streams++;
903
904         if (inode->i_visited)
905                 return 0;
906
907         /* Add each blob to 'ctx->blob_list' only one time, regardless of how
908          * many extraction targets it will have.  */
909         if (blob->out_refcnt == 0) {
910                 list_add_tail(&blob->extraction_list, &ctx->blob_list);
911                 ctx->num_blobs_remaining++;
912         }
913
914         /* Set this stream as an extraction target of 'blob'.  */
915
916         if (blob->out_refcnt < ARRAY_LEN(blob->inline_blob_extraction_targets)) {
917                 targets = blob->inline_blob_extraction_targets;
918         } else {
919                 struct blob_extraction_target *prev_targets;
920                 size_t alloc_blob_extraction_targets;
921
922                 if (blob->out_refcnt == ARRAY_LEN(blob->inline_blob_extraction_targets)) {
923                         prev_targets = NULL;
924                         alloc_blob_extraction_targets = ARRAY_LEN(blob->inline_blob_extraction_targets);
925                 } else {
926                         prev_targets = blob->blob_extraction_targets;
927                         alloc_blob_extraction_targets = blob->alloc_blob_extraction_targets;
928                 }
929
930                 if (blob->out_refcnt == alloc_blob_extraction_targets) {
931                         alloc_blob_extraction_targets *= 2;
932                         targets = REALLOC(prev_targets,
933                                           alloc_blob_extraction_targets *
934                                           sizeof(targets[0]));
935                         if (!targets)
936                                 return WIMLIB_ERR_NOMEM;
937                         if (!prev_targets) {
938                                 memcpy(targets,
939                                        blob->inline_blob_extraction_targets,
940                                        sizeof(blob->inline_blob_extraction_targets));
941                         }
942                         blob->blob_extraction_targets = targets;
943                         blob->alloc_blob_extraction_targets = alloc_blob_extraction_targets;
944                 }
945                 targets = blob->blob_extraction_targets;
946         }
947         targets[blob->out_refcnt].inode = inode;
948         targets[blob->out_refcnt].stream = strm;
949         blob->out_refcnt++;
950         return 0;
951 }
952
953 static int
954 ref_stream_if_needed(struct wim_dentry *dentry, struct wim_inode *inode,
955                      struct wim_inode_stream *strm, struct apply_ctx *ctx)
956 {
957         bool need_stream = false;
958         switch (strm->stream_type) {
959         case STREAM_TYPE_DATA:
960                 if (stream_is_named(strm)) {
961                         /* Named data stream  */
962                         if (ctx->supported_features.named_data_streams)
963                                 need_stream = true;
964                 } else if (!(inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
965                                                     FILE_ATTRIBUTE_ENCRYPTED))
966                            && !(inode_is_symlink(inode)
967                                 && !ctx->supported_features.reparse_points
968                                 && ctx->supported_features.symlink_reparse_points))
969                 {
970                         /*
971                          * Unnamed data stream.  Skip if any of the following is true:
972                          *
973                          * - file is a directory
974                          * - file is encrypted
975                          * - backend needs to create the file as UNIX symlink
976                          * - backend will extract the stream as externally backed
977                          */
978                         if (ctx->apply_ops->will_externally_back) {
979                                 int ret = (*ctx->apply_ops->will_externally_back)(dentry, ctx);
980                                 if (ret > 0) /* Error?  */
981                                         return ret;
982                                 if (ret < 0) /* Won't externally back?  */
983                                         need_stream = true;
984                         } else {
985                                 need_stream = true;
986                         }
987                 }
988                 break;
989         case STREAM_TYPE_REPARSE_POINT:
990                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT);
991                 if (ctx->supported_features.reparse_points ||
992                     (inode_is_symlink(inode) &&
993                      ctx->supported_features.symlink_reparse_points))
994                         need_stream = true;
995                 break;
996         case STREAM_TYPE_EFSRPC_RAW_DATA:
997                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED);
998                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
999                         if (ctx->supported_features.encrypted_directories)
1000                                 need_stream = true;
1001                 } else {
1002                         if (ctx->supported_features.encrypted_files)
1003                                 need_stream = true;
1004                 }
1005                 break;
1006         }
1007         if (need_stream)
1008                 return ref_stream(strm, dentry, ctx);
1009         return 0;
1010 }
1011
1012 static int
1013 dentry_ref_streams(struct wim_dentry *dentry, struct apply_ctx *ctx)
1014 {
1015         struct wim_inode *inode = dentry->d_inode;
1016         for (unsigned i = 0; i < inode->i_num_streams; i++) {
1017                 int ret = ref_stream_if_needed(dentry, inode,
1018                                                &inode->i_streams[i], ctx);
1019                 if (ret)
1020                         return ret;
1021         }
1022         inode->i_visited = 1;
1023         return 0;
1024 }
1025
1026 /*
1027  * Given a list of dentries to be extracted, build the list of blobs that need
1028  * to be extracted, and for each blob determine the streams to which that blob
1029  * will be extracted.
1030  *
1031  * This also initializes the extract progress info with byte and blob
1032  * information.
1033  *
1034  * ctx->supported_features must be filled in.
1035  */
1036 static int
1037 dentry_list_ref_streams(struct list_head *dentry_list, struct apply_ctx *ctx)
1038 {
1039         struct wim_dentry *dentry;
1040         int ret;
1041
1042         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1043                 ret = dentry_ref_streams(dentry, ctx);
1044                 if (ret)
1045                         return ret;
1046         }
1047         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1048                 dentry->d_inode->i_visited = 0;
1049         return 0;
1050 }
1051
1052 static void
1053 dentry_list_build_inode_alias_lists(struct list_head *dentry_list)
1054 {
1055         struct wim_dentry *dentry;
1056
1057         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1058                 dentry->d_inode->i_first_extraction_alias = NULL;
1059
1060         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1061                 dentry->d_next_extraction_alias = dentry->d_inode->i_first_extraction_alias;
1062                 dentry->d_inode->i_first_extraction_alias = dentry;
1063         }
1064 }
1065
1066 static void
1067 inode_tally_features(const struct wim_inode *inode,
1068                      struct wim_features *features)
1069 {
1070         if (inode->i_attributes & FILE_ATTRIBUTE_ARCHIVE)
1071                 features->archive_files++;
1072         if (inode->i_attributes & FILE_ATTRIBUTE_HIDDEN)
1073                 features->hidden_files++;
1074         if (inode->i_attributes & FILE_ATTRIBUTE_SYSTEM)
1075                 features->system_files++;
1076         if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED)
1077                 features->compressed_files++;
1078         if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
1079                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
1080                         features->encrypted_directories++;
1081                 else
1082                         features->encrypted_files++;
1083         }
1084         if (inode->i_attributes & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
1085                 features->not_context_indexed_files++;
1086         if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE)
1087                 features->sparse_files++;
1088         if (inode_has_named_data_stream(inode))
1089                 features->named_data_streams++;
1090         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1091                 features->reparse_points++;
1092                 if (inode_is_symlink(inode))
1093                         features->symlink_reparse_points++;
1094                 else
1095                         features->other_reparse_points++;
1096         }
1097         if (inode_has_security_descriptor(inode))
1098                 features->security_descriptors++;
1099         if (inode_has_unix_data(inode))
1100                 features->unix_data++;
1101 }
1102
1103 /* Tally features necessary to extract a dentry and the corresponding inode.  */
1104 static void
1105 dentry_tally_features(struct wim_dentry *dentry, struct wim_features *features)
1106 {
1107         struct wim_inode *inode = dentry->d_inode;
1108
1109         if (dentry_has_short_name(dentry))
1110                 features->short_names++;
1111
1112         if (inode->i_visited) {
1113                 features->hard_links++;
1114         } else {
1115                 inode_tally_features(inode, features);
1116                 inode->i_visited = 1;
1117         }
1118 }
1119
1120 /* Tally the features necessary to extract the specified dentries.  */
1121 static void
1122 dentry_list_get_features(struct list_head *dentry_list,
1123                          struct wim_features *features)
1124 {
1125         struct wim_dentry *dentry;
1126
1127         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1128                 dentry_tally_features(dentry, features);
1129
1130         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1131                 dentry->d_inode->i_visited = 0;
1132 }
1133
1134 static int
1135 do_feature_check(const struct wim_features *required_features,
1136                  const struct wim_features *supported_features,
1137                  int extract_flags)
1138 {
1139         /* Encrypted files.  */
1140         if (required_features->encrypted_files &&
1141             !supported_features->encrypted_files)
1142                 WARNING("Ignoring EFS-encrypted data of %lu files",
1143                         required_features->encrypted_files);
1144
1145         /* Named data streams.  */
1146         if (required_features->named_data_streams &&
1147             !supported_features->named_data_streams)
1148                 WARNING("Ignoring named data streams of %lu files",
1149                         required_features->named_data_streams);
1150
1151         /* File attributes.  */
1152         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
1153                 /* Note: Don't bother the user about FILE_ATTRIBUTE_ARCHIVE.
1154                  * We're an archive program, so theoretically we can do what we
1155                  * want with it.  */
1156
1157                 if (required_features->hidden_files &&
1158                     !supported_features->hidden_files)
1159                         WARNING("Ignoring FILE_ATTRIBUTE_HIDDEN of %lu files",
1160                                 required_features->hidden_files);
1161
1162                 if (required_features->system_files &&
1163                     !supported_features->system_files)
1164                         WARNING("Ignoring FILE_ATTRIBUTE_SYSTEM of %lu files",
1165                                 required_features->system_files);
1166
1167                 if (required_features->compressed_files &&
1168                     !supported_features->compressed_files)
1169                         WARNING("Ignoring FILE_ATTRIBUTE_COMPRESSED of %lu files",
1170                                 required_features->compressed_files);
1171
1172                 if (required_features->not_context_indexed_files &&
1173                     !supported_features->not_context_indexed_files)
1174                         WARNING("Ignoring FILE_ATTRIBUTE_NOT_CONTENT_INDEXED of %lu files",
1175                                 required_features->not_context_indexed_files);
1176
1177                 if (required_features->sparse_files &&
1178                     !supported_features->sparse_files)
1179                         WARNING("Ignoring FILE_ATTRIBUTE_SPARSE_FILE of %lu files",
1180                                 required_features->sparse_files);
1181
1182                 if (required_features->encrypted_directories &&
1183                     !supported_features->encrypted_directories)
1184                         WARNING("Ignoring FILE_ATTRIBUTE_ENCRYPTED of %lu directories",
1185                                 required_features->encrypted_directories);
1186         }
1187
1188         /* Hard links.  */
1189         if (required_features->hard_links && !supported_features->hard_links)
1190                 WARNING("Extracting %lu hard links as independent files",
1191                         required_features->hard_links);
1192
1193         /* Symbolic links and reparse points.  */
1194         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS) &&
1195             required_features->symlink_reparse_points &&
1196             !supported_features->symlink_reparse_points &&
1197             !supported_features->reparse_points)
1198         {
1199                 ERROR("Extraction backend does not support symbolic links!");
1200                 return WIMLIB_ERR_UNSUPPORTED;
1201         }
1202         if (required_features->reparse_points &&
1203             !supported_features->reparse_points)
1204         {
1205                 if (supported_features->symlink_reparse_points) {
1206                         if (required_features->other_reparse_points) {
1207                                 WARNING("Ignoring reparse data of %lu non-symlink/junction files",
1208                                         required_features->other_reparse_points);
1209                         }
1210                 } else {
1211                         WARNING("Ignoring reparse data of %lu files",
1212                                 required_features->reparse_points);
1213                 }
1214         }
1215
1216         /* Security descriptors.  */
1217         if (((extract_flags & (WIMLIB_EXTRACT_FLAG_STRICT_ACLS |
1218                                WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1219              == WIMLIB_EXTRACT_FLAG_STRICT_ACLS) &&
1220             required_features->security_descriptors &&
1221             !supported_features->security_descriptors)
1222         {
1223                 ERROR("Extraction backend does not support security descriptors!");
1224                 return WIMLIB_ERR_UNSUPPORTED;
1225         }
1226         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS) &&
1227             required_features->security_descriptors &&
1228             !supported_features->security_descriptors)
1229                 WARNING("Ignoring Windows NT security descriptors of %lu files",
1230                         required_features->security_descriptors);
1231
1232         /* UNIX data.  */
1233         if ((extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
1234             required_features->unix_data && !supported_features->unix_data)
1235         {
1236                 ERROR("Extraction backend does not support UNIX data!");
1237                 return WIMLIB_ERR_UNSUPPORTED;
1238         }
1239
1240         if (required_features->unix_data &&
1241             !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1242         {
1243                 WARNING("Ignoring UNIX metadata of %lu files",
1244                         required_features->unix_data);
1245         }
1246
1247         /* DOS Names.  */
1248         if (required_features->short_names &&
1249             !supported_features->short_names)
1250         {
1251                 if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES) {
1252                         ERROR("Extraction backend does not support DOS names!");
1253                         return WIMLIB_ERR_UNSUPPORTED;
1254                 }
1255                 WARNING("Ignoring DOS names of %lu files",
1256                         required_features->short_names);
1257         }
1258
1259         /* Timestamps.  */
1260         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) &&
1261             !supported_features->timestamps)
1262         {
1263                 ERROR("Extraction backend does not support timestamps!");
1264                 return WIMLIB_ERR_UNSUPPORTED;
1265         }
1266
1267         return 0;
1268 }
1269
1270 static const struct apply_operations *
1271 select_apply_operations(int extract_flags)
1272 {
1273 #ifdef WITH_NTFS_3G
1274         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
1275                 return &ntfs_3g_apply_ops;
1276 #endif
1277 #ifdef __WIN32__
1278         return &win32_apply_ops;
1279 #else
1280         return &unix_apply_ops;
1281 #endif
1282 }
1283
1284 static int
1285 extract_trees(WIMStruct *wim, struct wim_dentry **trees, size_t num_trees,
1286               const tchar *target, int extract_flags)
1287 {
1288         const struct apply_operations *ops;
1289         struct apply_ctx *ctx;
1290         int ret;
1291         LIST_HEAD(dentry_list);
1292
1293         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
1294                 ret = extract_dentries_to_stdout(trees, num_trees,
1295                                                  wim->blob_table);
1296                 goto out;
1297         }
1298
1299         num_trees = remove_duplicate_trees(trees, num_trees);
1300         num_trees = remove_contained_trees(trees, num_trees);
1301
1302         ops = select_apply_operations(extract_flags);
1303
1304         if (num_trees > 1 && ops->single_tree_only) {
1305                 ERROR("Extracting multiple directory trees "
1306                       "at once is not supported in %s extraction mode!",
1307                       ops->name);
1308                 ret = WIMLIB_ERR_UNSUPPORTED;
1309                 goto out;
1310         }
1311
1312         ctx = CALLOC(1, ops->context_size);
1313         if (!ctx) {
1314                 ret = WIMLIB_ERR_NOMEM;
1315                 goto out;
1316         }
1317
1318         ctx->wim = wim;
1319         ctx->target = target;
1320         ctx->target_nchars = tstrlen(target);
1321         ctx->extract_flags = extract_flags;
1322         if (ctx->wim->progfunc) {
1323                 ctx->progfunc = ctx->wim->progfunc;
1324                 ctx->progctx = ctx->wim->progctx;
1325                 ctx->progress.extract.image = wim->current_image;
1326                 ctx->progress.extract.extract_flags = (extract_flags &
1327                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
1328                 ctx->progress.extract.wimfile_name = wim->filename;
1329                 ctx->progress.extract.image_name = wimlib_get_image_name(wim,
1330                                                                          wim->current_image);
1331                 ctx->progress.extract.target = target;
1332         }
1333         INIT_LIST_HEAD(&ctx->blob_list);
1334         filedes_invalidate(&ctx->tmpfile_fd);
1335         ctx->apply_ops = ops;
1336
1337         ret = (*ops->get_supported_features)(target, &ctx->supported_features);
1338         if (ret)
1339                 goto out_cleanup;
1340
1341         build_dentry_list(&dentry_list, trees, num_trees,
1342                           !(extract_flags &
1343                             WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE));
1344
1345         dentry_list_get_features(&dentry_list, &ctx->required_features);
1346
1347         ret = do_feature_check(&ctx->required_features, &ctx->supported_features,
1348                                ctx->extract_flags);
1349         if (ret)
1350                 goto out_cleanup;
1351
1352         ret = dentry_list_calculate_extraction_names(&dentry_list, ctx);
1353         if (ret)
1354                 goto out_cleanup;
1355
1356         if (unlikely(list_empty(&dentry_list))) {
1357                 WARNING("There is nothing to extract!");
1358                 goto out_cleanup;
1359         }
1360
1361         ret = dentry_list_resolve_streams(&dentry_list, ctx);
1362         if (ret)
1363                 goto out_cleanup;
1364
1365         dentry_list_build_inode_alias_lists(&dentry_list);
1366
1367         ret = dentry_list_ref_streams(&dentry_list, ctx);
1368         if (ret)
1369                 goto out_cleanup;
1370
1371         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
1372                 /* When extracting from a pipe, the number of bytes of data to
1373                  * extract can't be determined in the normal way (examining the
1374                  * blob table), since at this point all we have is a set of
1375                  * SHA-1 message digests of blobs that need to be extracted.
1376                  * However, we can get a reasonably accurate estimate by taking
1377                  * <TOTALBYTES> from the corresponding <IMAGE> in the WIM XML
1378                  * data.  This does assume that a full image is being extracted,
1379                  * but currently there is no API for doing otherwise.  (Also,
1380                  * subtract <HARDLINKBYTES> from this if hard links are
1381                  * supported by the extraction mode.)  */
1382                 ctx->progress.extract.total_bytes =
1383                         wim_info_get_image_total_bytes(wim->wim_info,
1384                                                        wim->current_image);
1385                 if (ctx->supported_features.hard_links) {
1386                         ctx->progress.extract.total_bytes -=
1387                                 wim_info_get_image_hard_link_bytes(wim->wim_info,
1388                                                                    wim->current_image);
1389                 }
1390         }
1391
1392         ret = extract_progress(ctx,
1393                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1394                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN :
1395                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN));
1396         if (ret)
1397                 goto out_cleanup;
1398
1399         ret = (*ops->extract)(&dentry_list, ctx);
1400         if (ret)
1401                 goto out_cleanup;
1402
1403         if (ctx->progress.extract.completed_bytes <
1404             ctx->progress.extract.total_bytes)
1405         {
1406                 ctx->progress.extract.completed_bytes =
1407                         ctx->progress.extract.total_bytes;
1408                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
1409                 if (ret)
1410                         goto out_cleanup;
1411         }
1412
1413         ret = extract_progress(ctx,
1414                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1415                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END :
1416                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END));
1417 out_cleanup:
1418         destroy_blob_list(&ctx->blob_list);
1419         destroy_dentry_list(&dentry_list);
1420         FREE(ctx);
1421 out:
1422         return ret;
1423 }
1424
1425 static int
1426 mkdir_if_needed(const tchar *target)
1427 {
1428         if (!tmkdir(target, 0755))
1429                 return 0;
1430
1431         if (errno == EEXIST)
1432                 return 0;
1433
1434 #ifdef __WIN32__
1435         /* _wmkdir() fails with EACCES if called on a drive root directory.  */
1436         if (errno == EACCES)
1437                 return 0;
1438 #endif
1439
1440         ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
1441         return WIMLIB_ERR_MKDIR;
1442 }
1443
1444 /* Make sure the extraction flags make sense, and update them if needed.  */
1445 static int
1446 check_extract_flags(const WIMStruct *wim, int *extract_flags_p)
1447 {
1448         int extract_flags = *extract_flags_p;
1449
1450         /* Check for invalid flag combinations  */
1451
1452         if ((extract_flags &
1453              (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1454               WIMLIB_EXTRACT_FLAG_STRICT_ACLS)) == (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1455                                                     WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
1456                 return WIMLIB_ERR_INVALID_PARAM;
1457
1458         if ((extract_flags &
1459              (WIMLIB_EXTRACT_FLAG_RPFIX |
1460               WIMLIB_EXTRACT_FLAG_NORPFIX)) == (WIMLIB_EXTRACT_FLAG_RPFIX |
1461                                                 WIMLIB_EXTRACT_FLAG_NORPFIX))
1462                 return WIMLIB_ERR_INVALID_PARAM;
1463
1464 #ifndef WITH_NTFS_3G
1465         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1466                 ERROR("wimlib was compiled without support for NTFS-3g, so\n"
1467                       "        it cannot apply a WIM image directly to an NTFS volume.");
1468                 return WIMLIB_ERR_UNSUPPORTED;
1469         }
1470 #endif
1471
1472         if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
1473 #ifdef __WIN32__
1474                 if (!wim->filename)
1475                         return WIMLIB_ERR_NO_FILENAME;
1476 #else
1477                 ERROR("WIMBoot extraction is only supported on Windows!");
1478                 return WIMLIB_ERR_UNSUPPORTED;
1479 #endif
1480         }
1481
1482
1483         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
1484                               WIMLIB_EXTRACT_FLAG_NORPFIX |
1485                               WIMLIB_EXTRACT_FLAG_IMAGEMODE)) ==
1486                                         WIMLIB_EXTRACT_FLAG_IMAGEMODE)
1487         {
1488                 /* For full-image extraction, do reparse point fixups by default
1489                  * if the WIM header says they are enabled.  */
1490                 if (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
1491                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
1492         }
1493
1494         *extract_flags_p = extract_flags;
1495         return 0;
1496 }
1497
1498 struct append_dentry_ctx {
1499         struct wim_dentry **dentries;
1500         size_t num_dentries;
1501         size_t num_alloc_dentries;
1502 };
1503
1504 static int
1505 append_dentry_cb(struct wim_dentry *dentry, void *_ctx)
1506 {
1507         struct append_dentry_ctx *ctx = _ctx;
1508
1509         if (ctx->num_dentries == ctx->num_alloc_dentries) {
1510                 struct wim_dentry **new_dentries;
1511                 size_t new_length;
1512
1513                 new_length = max(ctx->num_alloc_dentries + 8,
1514                                  ctx->num_alloc_dentries * 3 / 2);
1515                 new_dentries = REALLOC(ctx->dentries,
1516                                        new_length * sizeof(ctx->dentries[0]));
1517                 if (new_dentries == NULL)
1518                         return WIMLIB_ERR_NOMEM;
1519                 ctx->dentries = new_dentries;
1520                 ctx->num_alloc_dentries = new_length;
1521         }
1522         ctx->dentries[ctx->num_dentries++] = dentry;
1523         return 0;
1524 }
1525
1526 /* Append dentries matched by a path which can contain wildcard characters.  */
1527 static int
1528 append_matched_dentries(WIMStruct *wim, const tchar *orig_pattern,
1529                         int extract_flags, struct append_dentry_ctx *ctx)
1530 {
1531         const size_t count_before = ctx->num_dentries;
1532         tchar *pattern;
1533         int ret;
1534
1535         pattern = canonicalize_wim_path(orig_pattern);
1536         if (!pattern)
1537                 return WIMLIB_ERR_NOMEM;
1538         ret = expand_path_pattern(wim_get_current_root_dentry(wim), pattern,
1539                                   append_dentry_cb, ctx);
1540         FREE(pattern);
1541         if (ret || ctx->num_dentries > count_before)
1542                 return ret;
1543         if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_GLOB) {
1544                 ERROR("No matches for path pattern \"%"TS"\"", orig_pattern);
1545                 return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1546         }
1547         WARNING("No matches for path pattern \"%"TS"\"", orig_pattern);
1548         return 0;
1549 }
1550
1551 static int
1552 do_wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1553                         const tchar * const *paths, size_t num_paths,
1554                         int extract_flags)
1555 {
1556         int ret;
1557         struct wim_dentry **trees;
1558         size_t num_trees;
1559
1560         if (wim == NULL || target == NULL || target[0] == T('\0') ||
1561             (num_paths != 0 && paths == NULL))
1562                 return WIMLIB_ERR_INVALID_PARAM;
1563
1564         ret = check_extract_flags(wim, &extract_flags);
1565         if (ret)
1566                 return ret;
1567
1568         ret = select_wim_image(wim, image);
1569         if (ret)
1570                 return ret;
1571
1572         ret = wim_checksum_unhashed_blobs(wim);
1573         if (ret)
1574                 return ret;
1575
1576         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_NTFS |
1577                               WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE)) ==
1578             (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE))
1579         {
1580                 ret = mkdir_if_needed(target);
1581                 if (ret)
1582                         return ret;
1583         }
1584
1585         if (extract_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {
1586
1587                 struct append_dentry_ctx append_dentry_ctx = {
1588                         .dentries = NULL,
1589                         .num_dentries = 0,
1590                         .num_alloc_dentries = 0,
1591                 };
1592
1593                 for (size_t i = 0; i < num_paths; i++) {
1594                         ret = append_matched_dentries(wim, paths[i],
1595                                                       extract_flags,
1596                                                       &append_dentry_ctx);
1597                         if (ret) {
1598                                 trees = append_dentry_ctx.dentries;
1599                                 goto out_free_trees;
1600                         }
1601                 }
1602                 trees = append_dentry_ctx.dentries;
1603                 num_trees = append_dentry_ctx.num_dentries;
1604         } else {
1605                 trees = MALLOC(num_paths * sizeof(trees[0]));
1606                 if (trees == NULL)
1607                         return WIMLIB_ERR_NOMEM;
1608
1609                 for (size_t i = 0; i < num_paths; i++) {
1610
1611                         tchar *path = canonicalize_wim_path(paths[i]);
1612                         if (path == NULL) {
1613                                 ret = WIMLIB_ERR_NOMEM;
1614                                 goto out_free_trees;
1615                         }
1616
1617                         trees[i] = get_dentry(wim, path,
1618                                               WIMLIB_CASE_PLATFORM_DEFAULT);
1619                         FREE(path);
1620                         if (trees[i] == NULL) {
1621                                   ERROR("Path \"%"TS"\" does not exist "
1622                                         "in WIM image %d",
1623                                         paths[i], wim->current_image);
1624                                   ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1625                                   goto out_free_trees;
1626                         }
1627                 }
1628                 num_trees = num_paths;
1629         }
1630
1631         if (num_trees == 0) {
1632                 ret = 0;
1633                 goto out_free_trees;
1634         }
1635
1636         ret = extract_trees(wim, trees, num_trees, target, extract_flags);
1637 out_free_trees:
1638         FREE(trees);
1639         return ret;
1640 }
1641
1642 static int
1643 extract_single_image(WIMStruct *wim, int image,
1644                      const tchar *target, int extract_flags)
1645 {
1646         const tchar *path = WIMLIB_WIM_ROOT_PATH;
1647         extract_flags |= WIMLIB_EXTRACT_FLAG_IMAGEMODE;
1648         return do_wimlib_extract_paths(wim, image, target, &path, 1, extract_flags);
1649 }
1650
1651 static const tchar * const filename_forbidden_chars =
1652 T(
1653 #ifdef __WIN32__
1654 "<>:\"/\\|?*"
1655 #else
1656 "/"
1657 #endif
1658 );
1659
1660 /* This function checks if it is okay to use a WIM image's name as a directory
1661  * name.  */
1662 static bool
1663 image_name_ok_as_dir(const tchar *image_name)
1664 {
1665         return image_name && *image_name &&
1666                 !tstrpbrk(image_name, filename_forbidden_chars) &&
1667                 tstrcmp(image_name, T(".")) &&
1668                 tstrcmp(image_name, T(".."));
1669 }
1670
1671 /* Extracts all images from the WIM to the directory @target, with the images
1672  * placed in subdirectories named by their image names. */
1673 static int
1674 extract_all_images(WIMStruct *wim, const tchar *target, int extract_flags)
1675 {
1676         size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
1677         size_t output_path_len = tstrlen(target);
1678         tchar buf[output_path_len + 1 + image_name_max_len + 1];
1679         int ret;
1680         int image;
1681         const tchar *image_name;
1682
1683         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1684                 ERROR("Cannot extract multiple images in NTFS extraction mode.");
1685                 return WIMLIB_ERR_INVALID_PARAM;
1686         }
1687
1688         ret = mkdir_if_needed(target);
1689         if (ret)
1690                 return ret;
1691         tmemcpy(buf, target, output_path_len);
1692         buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
1693         for (image = 1; image <= wim->hdr.image_count; image++) {
1694                 image_name = wimlib_get_image_name(wim, image);
1695                 if (image_name_ok_as_dir(image_name)) {
1696                         tstrcpy(buf + output_path_len + 1, image_name);
1697                 } else {
1698                         /* Image name is empty or contains forbidden characters.
1699                          * Use image number instead. */
1700                         tsprintf(buf + output_path_len + 1, T("%d"), image);
1701                 }
1702                 ret = extract_single_image(wim, image, buf, extract_flags);
1703                 if (ret)
1704                         return ret;
1705         }
1706         return 0;
1707 }
1708
1709 static int
1710 do_wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1711                         int extract_flags)
1712 {
1713         if (extract_flags & (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
1714                              WIMLIB_EXTRACT_FLAG_TO_STDOUT |
1715                              WIMLIB_EXTRACT_FLAG_GLOB_PATHS))
1716                 return WIMLIB_ERR_INVALID_PARAM;
1717
1718         if (image == WIMLIB_ALL_IMAGES)
1719                 return extract_all_images(wim, target, extract_flags);
1720         else
1721                 return extract_single_image(wim, image, target, extract_flags);
1722 }
1723
1724
1725 /****************************************************************************
1726  *                          Extraction API                                  *
1727  ****************************************************************************/
1728
1729 WIMLIBAPI int
1730 wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1731                      const tchar * const *paths, size_t num_paths,
1732                      int extract_flags)
1733 {
1734         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1735                 return WIMLIB_ERR_INVALID_PARAM;
1736
1737         return do_wimlib_extract_paths(wim, image, target, paths, num_paths,
1738                                        extract_flags);
1739 }
1740
1741 WIMLIBAPI int
1742 wimlib_extract_pathlist(WIMStruct *wim, int image, const tchar *target,
1743                         const tchar *path_list_file, int extract_flags)
1744 {
1745         int ret;
1746         tchar **paths;
1747         size_t num_paths;
1748         void *mem;
1749
1750         ret = read_path_list_file(path_list_file, &paths, &num_paths, &mem);
1751         if (ret) {
1752                 ERROR("Failed to read path list file \"%"TS"\"",
1753                       path_list_file);
1754                 return ret;
1755         }
1756
1757         ret = wimlib_extract_paths(wim, image, target,
1758                                    (const tchar * const *)paths, num_paths,
1759                                    extract_flags);
1760         FREE(paths);
1761         FREE(mem);
1762         return ret;
1763 }
1764
1765 WIMLIBAPI int
1766 wimlib_extract_image_from_pipe_with_progress(int pipe_fd,
1767                                              const tchar *image_num_or_name,
1768                                              const tchar *target,
1769                                              int extract_flags,
1770                                              wimlib_progress_func_t progfunc,
1771                                              void *progctx)
1772 {
1773         int ret;
1774         WIMStruct *pwm;
1775         struct filedes *in_fd;
1776         int image;
1777         unsigned i;
1778
1779         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1780                 return WIMLIB_ERR_INVALID_PARAM;
1781
1782         /* Read the WIM header from the pipe and get a WIMStruct to represent
1783          * the pipable WIM.  Caveats:  Unlike getting a WIMStruct with
1784          * wimlib_open_wim(), getting a WIMStruct in this way will result in an
1785          * empty blob table, no XML data read, and no filename set.  */
1786         ret = open_wim_as_WIMStruct(&pipe_fd, WIMLIB_OPEN_FLAG_FROM_PIPE, &pwm,
1787                                     progfunc, progctx);
1788         if (ret)
1789                 return ret;
1790
1791         /* Sanity check to make sure this is a pipable WIM.  */
1792         if (pwm->hdr.magic != PWM_MAGIC) {
1793                 ERROR("The WIM being read from file descriptor %d "
1794                       "is not pipable!", pipe_fd);
1795                 ret = WIMLIB_ERR_NOT_PIPABLE;
1796                 goto out_wimlib_free;
1797         }
1798
1799         /* Sanity check to make sure the first part of a pipable split WIM is
1800          * sent over the pipe first.  */
1801         if (pwm->hdr.part_number != 1) {
1802                 ERROR("The first part of the split WIM must be "
1803                       "sent over the pipe first.");
1804                 ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1805                 goto out_wimlib_free;
1806         }
1807
1808         in_fd = &pwm->in_fd;
1809         wimlib_assert(in_fd->offset == WIM_HEADER_DISK_SIZE);
1810
1811         /* As mentioned, the WIMStruct we created from the pipe does not have
1812          * XML data yet.  Fix this by reading the extra copy of the XML data
1813          * that directly follows the header in pipable WIMs.  (Note: see
1814          * write_pipable_wim() for more details about the format of pipable
1815          * WIMs.)  */
1816         {
1817                 u8 hash[SHA1_HASH_SIZE];
1818
1819                 ret = read_pwm_blob_header(pwm, hash,
1820                                            &pwm->hdr.xml_data_reshdr, NULL);
1821                 if (ret)
1822                         goto out_wimlib_free;
1823
1824                 if (!(pwm->hdr.xml_data_reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1825                         ERROR("Expected XML data, but found non-metadata resource.");
1826                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1827                         goto out_wimlib_free;
1828                 }
1829
1830                 ret = read_wim_xml_data(pwm);
1831                 if (ret)
1832                         goto out_wimlib_free;
1833
1834                 if (wim_info_get_num_images(pwm->wim_info) != pwm->hdr.image_count) {
1835                         ERROR("Image count in XML data is not the same as in WIM header.");
1836                         ret = WIMLIB_ERR_IMAGE_COUNT;
1837                         goto out_wimlib_free;
1838                 }
1839         }
1840
1841         /* Get image index (this may use the XML data that was just read to
1842          * resolve an image name).  */
1843         if (image_num_or_name) {
1844                 image = wimlib_resolve_image(pwm, image_num_or_name);
1845                 if (image == WIMLIB_NO_IMAGE) {
1846                         ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
1847                               image_num_or_name);
1848                         ret = WIMLIB_ERR_INVALID_IMAGE;
1849                         goto out_wimlib_free;
1850                 } else if (image == WIMLIB_ALL_IMAGES) {
1851                         ERROR("Applying all images from a pipe is not supported!");
1852                         ret = WIMLIB_ERR_INVALID_IMAGE;
1853                         goto out_wimlib_free;
1854                 }
1855         } else {
1856                 if (pwm->hdr.image_count != 1) {
1857                         ERROR("No image was specified, but the pipable WIM "
1858                               "did not contain exactly 1 image");
1859                         ret = WIMLIB_ERR_INVALID_IMAGE;
1860                         goto out_wimlib_free;
1861                 }
1862                 image = 1;
1863         }
1864
1865         /* Load the needed metadata resource.  */
1866         for (i = 1; i <= pwm->hdr.image_count; i++) {
1867                 struct wim_image_metadata *imd;
1868                 struct wim_reshdr reshdr;
1869                 struct wim_resource_descriptor *metadata_rdesc;
1870
1871                 imd = pwm->image_metadata[i - 1];
1872
1873                 ret = WIMLIB_ERR_NOMEM;
1874                 imd->metadata_blob = new_blob_descriptor();
1875                 if (!imd->metadata_blob)
1876                         goto out_wimlib_free;
1877
1878                 imd->metadata_blob->is_metadata = 1;
1879
1880                 ret = read_pwm_blob_header(pwm, imd->metadata_blob->hash,
1881                                            &reshdr, NULL);
1882                 if (ret)
1883                         goto out_wimlib_free;
1884
1885                 if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1886                         ERROR("Expected metadata resource, but found "
1887                               "non-metadata resource");
1888                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1889                         goto out_wimlib_free;
1890                 }
1891
1892                 ret = WIMLIB_ERR_NOMEM;
1893                 metadata_rdesc = MALLOC(sizeof(struct wim_resource_descriptor));
1894                 if (!metadata_rdesc)
1895                         goto out_wimlib_free;
1896                 wim_reshdr_to_desc_and_blob(&reshdr, pwm, metadata_rdesc,
1897                                             imd->metadata_blob);
1898
1899                 if (i == image) {
1900                         /* Metadata resource is for the image being extracted.
1901                          * Parse it and save the metadata in memory.  */
1902                         ret = read_metadata_resource(imd);
1903                         if (ret)
1904                                 goto out_wimlib_free;
1905                         imd->modified = 1;
1906                 } else {
1907                         /* Metadata resource is not for the image being
1908                          * extracted.  Skip over it.  */
1909                         ret = skip_wim_resource(metadata_rdesc);
1910                         if (ret)
1911                                 goto out_wimlib_free;
1912                 }
1913         }
1914         /* Extract the image.  */
1915         extract_flags |= WIMLIB_EXTRACT_FLAG_FROM_PIPE;
1916         ret = do_wimlib_extract_image(pwm, image, target, extract_flags);
1917         /* Clean up and return.  */
1918 out_wimlib_free:
1919         wimlib_free(pwm);
1920         return ret;
1921 }
1922
1923
1924 WIMLIBAPI int
1925 wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
1926                                const tchar *target, int extract_flags)
1927 {
1928         return wimlib_extract_image_from_pipe_with_progress(pipe_fd,
1929                                                             image_num_or_name,
1930                                                             target,
1931                                                             extract_flags,
1932                                                             NULL,
1933                                                             NULL);
1934 }
1935
1936 WIMLIBAPI int
1937 wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1938                      int extract_flags)
1939 {
1940         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1941                 return WIMLIB_ERR_INVALID_PARAM;
1942         return do_wimlib_extract_image(wim, image, target, extract_flags);
1943 }