extract.c: add missing will_extract_dentry() check
[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/reparse.h"
58 #include "wimlib/resource.h"
59 #include "wimlib/security.h"
60 #include "wimlib/unix_data.h"
61 #include "wimlib/wildcard.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                 if (progress->extract.completed_bytes >=
345                     progress->extract.total_bytes)
346                 {
347                         ctx->next_progress = UINT64_MAX;
348                 } else {
349                         /* Send new message as soon as another 1/128 of the
350                          * total has been extracted.  (Arbitrary number.)  */
351                         ctx->next_progress =
352                                 progress->extract.completed_bytes +
353                                         progress->extract.total_bytes / 128;
354
355                         /* ... Unless that would be more than 5000000 bytes, in
356                          * which case send the next after the next 5000000
357                          * bytes.  (Another arbitrary number.)  */
358                         if (progress->extract.completed_bytes + 5000000 <
359                             ctx->next_progress)
360                                 ctx->next_progress =
361                                         progress->extract.completed_bytes + 5000000;
362
363                         /* ... But always send a message as soon as we're
364                          * completely done.  */
365                         if (progress->extract.total_bytes < ctx->next_progress)
366                                 ctx->next_progress = progress->extract.total_bytes;
367                 }
368         }
369
370         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
371                 /* Just extracting to temporary file for now.  */
372                 ret = full_write(&ctx->tmpfile_fd, chunk, size);
373                 if (ret) {
374                         ERROR_WITH_ERRNO("Error writing data to "
375                                          "temporary file \"%"TS"\"",
376                                          ctx->tmpfile_name);
377                 }
378                 return ret;
379         }
380
381         return call_consume_chunk(chunk, size, ctx->saved_cbs);
382 }
383
384 /* Copy the blob's data from the temporary file to each of its targets.
385  *
386  * This is executed only in the very uncommon case that a blob is being
387  * extracted to more than MAX_OPEN_FILES targets!  */
388 static int
389 extract_from_tmpfile(const tchar *tmpfile_name,
390                      const struct blob_descriptor *orig_blob,
391                      const struct read_blob_callbacks *cbs)
392 {
393         struct blob_descriptor tmpfile_blob;
394         const struct blob_extraction_target *targets = blob_extraction_targets(orig_blob);
395         int ret;
396
397         memcpy(&tmpfile_blob, orig_blob, sizeof(struct blob_descriptor));
398         tmpfile_blob.blob_location = BLOB_IN_FILE_ON_DISK;
399         tmpfile_blob.file_on_disk = (tchar *)tmpfile_name;
400         tmpfile_blob.out_refcnt = 1;
401
402         for (u32 i = 0; i < orig_blob->out_refcnt; i++) {
403                 tmpfile_blob.inline_blob_extraction_targets[0] = targets[i];
404                 ret = read_blob_with_cbs(&tmpfile_blob, cbs);
405                 if (ret)
406                         return ret;
407         }
408         return 0;
409 }
410
411 static int
412 end_extract_blob_wrapper(struct blob_descriptor *blob, int status, void *_ctx)
413 {
414         struct apply_ctx *ctx = _ctx;
415
416         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
417                 filedes_close(&ctx->tmpfile_fd);
418                 if (!status)
419                         status = extract_from_tmpfile(ctx->tmpfile_name, blob,
420                                                       ctx->saved_cbs);
421                 filedes_invalidate(&ctx->tmpfile_fd);
422                 tunlink(ctx->tmpfile_name);
423                 FREE(ctx->tmpfile_name);
424                 return status;
425         }
426
427         return call_end_blob(blob, status, ctx->saved_cbs);
428 }
429
430 /*
431  * Read the list of blobs to extract and feed their data into the specified
432  * callback functions.
433  *
434  * This handles checksumming each blob.
435  *
436  * This also handles sending WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS.
437  *
438  * This also works if the WIM is being read from a pipe.
439  *
440  * This also will split up blobs that will need to be extracted to more than
441  * MAX_OPEN_FILES locations, as measured by the 'out_refcnt' of each blob.
442  * Therefore, the apply_operations implementation need not worry about running
443  * out of file descriptors, unless it might open more than one file descriptor
444  * per 'blob_extraction_target' (e.g. Win32 currently might because the
445  * destination file system might not support hard links).
446  */
447 int
448 extract_blob_list(struct apply_ctx *ctx, const struct read_blob_callbacks *cbs)
449 {
450         struct read_blob_callbacks wrapper_cbs = {
451                 .begin_blob     = begin_extract_blob_wrapper,
452                 .consume_chunk  = extract_chunk_wrapper,
453                 .end_blob       = end_extract_blob_wrapper,
454                 .ctx            = ctx,
455         };
456         ctx->saved_cbs = cbs;
457         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
458                 return read_blobs_from_pipe(ctx, &wrapper_cbs);
459         } else {
460                 return read_blob_list(&ctx->blob_list,
461                                       offsetof(struct blob_descriptor,
462                                                extraction_list),
463                                       &wrapper_cbs, VERIFY_BLOB_HASHES);
464         }
465 }
466
467 /* Extract a WIM dentry to standard output.
468  *
469  * This obviously doesn't make sense in all cases.  We return an error if the
470  * dentry does not correspond to a regular file.  Otherwise we extract the
471  * unnamed data stream only.  */
472 static int
473 extract_dentry_to_stdout(struct wim_dentry *dentry,
474                          const struct blob_table *blob_table)
475 {
476         struct wim_inode *inode = dentry->d_inode;
477         struct blob_descriptor *blob;
478         struct filedes _stdout;
479
480         if (inode->i_attributes & (FILE_ATTRIBUTE_REPARSE_POINT |
481                                    FILE_ATTRIBUTE_DIRECTORY |
482                                    FILE_ATTRIBUTE_ENCRYPTED))
483         {
484                 ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
485                       "extracted to standard output", dentry_full_path(dentry));
486                 return WIMLIB_ERR_NOT_A_REGULAR_FILE;
487         }
488
489         blob = inode_get_blob_for_unnamed_data_stream(inode, blob_table);
490         if (!blob) {
491                 const u8 *hash = inode_get_hash_of_unnamed_data_stream(inode);
492                 if (!is_zero_hash(hash))
493                         return blob_not_found_error(inode, hash);
494                 return 0;
495         }
496
497         filedes_init(&_stdout, STDOUT_FILENO);
498         return extract_blob_to_fd(blob, &_stdout);
499 }
500
501 static int
502 extract_dentries_to_stdout(struct wim_dentry **dentries, size_t num_dentries,
503                            const struct blob_table *blob_table)
504 {
505         for (size_t i = 0; i < num_dentries; i++) {
506                 int ret = extract_dentry_to_stdout(dentries[i], blob_table);
507                 if (ret)
508                         return ret;
509         }
510         return 0;
511 }
512
513 /**********************************************************************/
514
515 /*
516  * Removes duplicate dentries from the array.
517  *
518  * Returns the new number of dentries, packed at the front of the array.
519  */
520 static size_t
521 remove_duplicate_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                 if (!trees[i]->d_tmp_flag) {
526                         /* Found distinct dentry.  */
527                         trees[i]->d_tmp_flag = 1;
528                         trees[j++] = trees[i];
529                 }
530         }
531         for (i = 0; i < j; i++)
532                 trees[i]->d_tmp_flag = 0;
533         return j;
534 }
535
536 /*
537  * Remove dentries that are descendants of other dentries in the array.
538  *
539  * Returns the new number of dentries, packed at the front of the array.
540  */
541 static size_t
542 remove_contained_trees(struct wim_dentry **trees, size_t num_trees)
543 {
544         size_t i, j = 0;
545         for (i = 0; i < num_trees; i++)
546                 trees[i]->d_tmp_flag = 1;
547         for (i = 0; i < num_trees; i++) {
548                 struct wim_dentry *d = trees[i];
549                 while (!dentry_is_root(d)) {
550                         d = d->d_parent;
551                         if (d->d_tmp_flag)
552                                 goto tree_contained;
553                 }
554                 trees[j++] = trees[i];
555                 continue;
556
557         tree_contained:
558                 trees[i]->d_tmp_flag = 0;
559         }
560
561         for (i = 0; i < j; i++)
562                 trees[i]->d_tmp_flag = 0;
563         return j;
564 }
565
566 static int
567 dentry_append_to_list(struct wim_dentry *dentry, void *_dentry_list)
568 {
569         struct list_head *dentry_list = _dentry_list;
570         list_add_tail(&dentry->d_extraction_list_node, dentry_list);
571         return 0;
572 }
573
574 static void
575 dentry_reset_extraction_list_node(struct wim_dentry *dentry)
576 {
577         dentry->d_extraction_list_node = (struct list_head){NULL, NULL};
578 }
579
580 static int
581 dentry_delete_from_list(struct wim_dentry *dentry, void *_ignore)
582 {
583         if (will_extract_dentry(dentry)) {
584                 list_del(&dentry->d_extraction_list_node);
585                 dentry_reset_extraction_list_node(dentry);
586         }
587         return 0;
588 }
589
590 /*
591  * Build the preliminary list of dentries to be extracted.
592  *
593  * The list maintains the invariant that if d1 and d2 are in the list and d1 is
594  * an ancestor of d2, then d1 appears before d2 in the list.
595  */
596 static void
597 build_dentry_list(struct list_head *dentry_list, struct wim_dentry **trees,
598                   size_t num_trees, bool add_ancestors)
599 {
600         INIT_LIST_HEAD(dentry_list);
601
602         /* Add the trees recursively.  */
603         for (size_t i = 0; i < num_trees; i++)
604                 for_dentry_in_tree(trees[i], dentry_append_to_list, dentry_list);
605
606         /* If requested, add ancestors of the trees.  */
607         if (add_ancestors) {
608                 for (size_t i = 0; i < num_trees; i++) {
609                         struct wim_dentry *dentry = trees[i];
610                         struct wim_dentry *ancestor;
611                         struct list_head *place_after;
612
613                         if (dentry_is_root(dentry))
614                                 continue;
615
616                         place_after = dentry_list;
617                         ancestor = dentry;
618                         do {
619                                 ancestor = ancestor->d_parent;
620                                 if (will_extract_dentry(ancestor)) {
621                                         place_after = &ancestor->d_extraction_list_node;
622                                         break;
623                                 }
624                         } while (!dentry_is_root(ancestor));
625
626                         ancestor = dentry;
627                         do {
628                                 ancestor = ancestor->d_parent;
629                                 if (will_extract_dentry(ancestor))
630                                         break;
631                                 list_add(&ancestor->d_extraction_list_node, place_after);
632                         } while (!dentry_is_root(ancestor));
633                 }
634         }
635 }
636
637 static void
638 destroy_dentry_list(struct list_head *dentry_list)
639 {
640         struct wim_dentry *dentry, *tmp;
641         struct wim_inode *inode;
642
643         list_for_each_entry_safe(dentry, tmp, dentry_list, d_extraction_list_node) {
644                 inode = dentry->d_inode;
645                 dentry_reset_extraction_list_node(dentry);
646                 inode->i_visited = 0;
647                 inode->i_can_externally_back = 0;
648                 if ((void *)dentry->d_extraction_name != (void *)dentry->d_name)
649                         FREE(dentry->d_extraction_name);
650                 dentry->d_extraction_name = NULL;
651                 dentry->d_extraction_name_nchars = 0;
652         }
653 }
654
655 static void
656 destroy_blob_list(struct list_head *blob_list)
657 {
658         struct blob_descriptor *blob;
659
660         list_for_each_entry(blob, blob_list, extraction_list)
661                 if (blob->out_refcnt > ARRAY_LEN(blob->inline_blob_extraction_targets))
662                         FREE(blob->blob_extraction_targets);
663 }
664
665 #ifdef __WIN32__
666 static const utf16lechar replacement_char = cpu_to_le16(0xfffd);
667 #else
668 static const utf16lechar replacement_char = cpu_to_le16('?');
669 #endif
670
671 static bool
672 file_name_valid(utf16lechar *name, size_t num_chars, bool fix)
673 {
674         size_t i;
675
676         if (num_chars == 0)
677                 return true;
678         for (i = 0; i < num_chars; i++) {
679                 switch (name[i]) {
680         #ifdef __WIN32__
681                 case cpu_to_le16('\\'):
682                 case cpu_to_le16(':'):
683                 case cpu_to_le16('*'):
684                 case cpu_to_le16('?'):
685                 case cpu_to_le16('"'):
686                 case cpu_to_le16('<'):
687                 case cpu_to_le16('>'):
688                 case cpu_to_le16('|'):
689         #endif
690                 case cpu_to_le16('/'):
691                 case cpu_to_le16('\0'):
692                         if (fix)
693                                 name[i] = replacement_char;
694                         else
695                                 return false;
696                 }
697         }
698
699 #ifdef __WIN32__
700         if (name[num_chars - 1] == cpu_to_le16(' ') ||
701             name[num_chars - 1] == cpu_to_le16('.'))
702         {
703                 if (fix)
704                         name[num_chars - 1] = replacement_char;
705                 else
706                         return false;
707         }
708 #endif
709         return true;
710 }
711
712 static int
713 dentry_calculate_extraction_name(struct wim_dentry *dentry,
714                                  struct apply_ctx *ctx)
715 {
716         int ret;
717
718         if (dentry_is_root(dentry))
719                 return 0;
720
721 #ifdef WITH_NTFS_3G
722         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
723                 dentry->d_extraction_name = dentry->d_name;
724                 dentry->d_extraction_name_nchars = dentry->d_name_nbytes /
725                                                    sizeof(utf16lechar);
726                 return 0;
727         }
728 #endif
729
730         if (!ctx->supported_features.case_sensitive_filenames) {
731                 struct wim_dentry *other;
732                 list_for_each_entry(other, &dentry->d_ci_conflict_list,
733                                     d_ci_conflict_list)
734                 {
735                         if (will_extract_dentry(other)) {
736                                 if (ctx->extract_flags &
737                                     WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS) {
738                                         WARNING("\"%"TS"\" has the same "
739                                                 "case-insensitive name as "
740                                                 "\"%"TS"\"; extracting "
741                                                 "dummy name instead",
742                                                 dentry_full_path(dentry),
743                                                 dentry_full_path(other));
744                                         goto out_replace;
745                                 } else {
746                                         WARNING("Not extracting \"%"TS"\": "
747                                                 "has same case-insensitive "
748                                                 "name as \"%"TS"\"",
749                                                 dentry_full_path(dentry),
750                                                 dentry_full_path(other));
751                                         goto skip_dentry;
752                                 }
753                         }
754                 }
755         }
756
757         if (file_name_valid(dentry->d_name, dentry->d_name_nbytes / 2, false)) {
758                 size_t nbytes = 0;
759                 ret = utf16le_get_tstr(dentry->d_name,
760                                        dentry->d_name_nbytes,
761                                        (const tchar **)&dentry->d_extraction_name,
762                                        &nbytes);
763                 dentry->d_extraction_name_nchars = nbytes / sizeof(tchar);
764                 return ret;
765         } else {
766                 if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
767                 {
768                         WARNING("\"%"TS"\" has an invalid filename "
769                                 "that is not supported on this platform; "
770                                 "extracting dummy name instead",
771                                 dentry_full_path(dentry));
772                         goto out_replace;
773                 } else {
774                         WARNING("Not extracting \"%"TS"\": has an invalid filename "
775                                 "that is not supported on this platform",
776                                 dentry_full_path(dentry));
777                         goto skip_dentry;
778                 }
779         }
780
781 out_replace:
782         {
783                 utf16lechar utf16_name_copy[dentry->d_name_nbytes / 2];
784
785                 memcpy(utf16_name_copy, dentry->d_name, dentry->d_name_nbytes);
786                 file_name_valid(utf16_name_copy, dentry->d_name_nbytes / 2, true);
787
788                 const tchar *tchar_name;
789                 size_t tchar_nchars;
790
791                 ret = utf16le_get_tstr(utf16_name_copy,
792                                        dentry->d_name_nbytes,
793                                        &tchar_name, &tchar_nchars);
794                 if (ret)
795                         return ret;
796
797                 tchar_nchars /= sizeof(tchar);
798
799                 size_t fixed_name_num_chars = tchar_nchars;
800                 tchar fixed_name[tchar_nchars + 50];
801
802                 tmemcpy(fixed_name, tchar_name, tchar_nchars);
803                 fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
804                                                  T(" (invalid filename #%lu)"),
805                                                  ++ctx->invalid_sequence);
806
807                 utf16le_put_tstr(tchar_name);
808
809                 dentry->d_extraction_name = TSTRDUP(fixed_name);
810                 if (!dentry->d_extraction_name)
811                         return WIMLIB_ERR_NOMEM;
812                 dentry->d_extraction_name_nchars = fixed_name_num_chars;
813         }
814         return 0;
815
816 skip_dentry:
817         for_dentry_in_tree(dentry, dentry_delete_from_list, NULL);
818         return 0;
819 }
820
821 /*
822  * Calculate the actual filename component at which each WIM dentry will be
823  * extracted, with special handling for dentries that are unsupported by the
824  * extraction backend or have invalid names.
825  *
826  * ctx->supported_features must be filled in.
827  *
828  * Possible error codes: WIMLIB_ERR_NOMEM, WIMLIB_ERR_INVALID_UTF16_STRING
829  */
830 static int
831 dentry_list_calculate_extraction_names(struct list_head *dentry_list,
832                                        struct apply_ctx *ctx)
833 {
834         struct list_head *prev, *cur;
835
836         /* Can't use list_for_each_entry() because a call to
837          * dentry_calculate_extraction_name() may delete the current dentry and
838          * its children from the list.  */
839
840         prev = dentry_list;
841         for (;;) {
842                 struct wim_dentry *dentry;
843                 int ret;
844
845                 cur = prev->next;
846                 if (cur == dentry_list)
847                         break;
848
849                 dentry = list_entry(cur, struct wim_dentry, d_extraction_list_node);
850
851                 ret = dentry_calculate_extraction_name(dentry, ctx);
852                 if (ret)
853                         return ret;
854
855                 if (prev->next == cur)
856                         prev = cur;
857                 else
858                         ; /* Current dentry and its children (which follow in
859                              the list) were deleted.  prev stays the same.  */
860         }
861         return 0;
862 }
863
864 static int
865 dentry_resolve_streams(struct wim_dentry *dentry, int extract_flags,
866                        struct blob_table *blob_table)
867 {
868         struct wim_inode *inode = dentry->d_inode;
869         struct blob_descriptor *blob;
870         int ret;
871         bool force = false;
872
873         /* Special case:  when extracting from a pipe, the WIM blob table is
874          * initially empty, so "resolving" an inode's streams is initially not
875          * possible.  However, we still need to keep track of which blobs,
876          * identified by SHA-1 message digests, need to be extracted, so we
877          * "resolve" the inode's streams anyway by allocating a 'struct
878          * blob_descriptor' for each one.  */
879         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
880                 force = true;
881         ret = inode_resolve_streams(inode, blob_table, force);
882         if (ret)
883                 return ret;
884         for (unsigned i = 0; i < inode->i_num_streams; i++) {
885                 blob = stream_blob_resolved(&inode->i_streams[i]);
886                 if (blob)
887                         blob->out_refcnt = 0;
888         }
889         return 0;
890 }
891
892 /*
893  * For each dentry to be extracted, resolve all streams in the corresponding
894  * inode and set 'out_refcnt' in all referenced blob_descriptors to 0.
895  *
896  * Possible error codes: WIMLIB_ERR_RESOURCE_NOT_FOUND, WIMLIB_ERR_NOMEM.
897  */
898 static int
899 dentry_list_resolve_streams(struct list_head *dentry_list,
900                             struct apply_ctx *ctx)
901 {
902         struct wim_dentry *dentry;
903         int ret;
904
905         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
906                 ret = dentry_resolve_streams(dentry,
907                                              ctx->extract_flags,
908                                              ctx->wim->blob_table);
909                 if (ret)
910                         return ret;
911         }
912         return 0;
913 }
914
915 static int
916 ref_stream(struct wim_inode_stream *strm, struct wim_dentry *dentry,
917            struct apply_ctx *ctx)
918 {
919         struct wim_inode *inode = dentry->d_inode;
920         struct blob_descriptor *blob = stream_blob_resolved(strm);
921         struct blob_extraction_target *targets;
922
923         if (!blob)
924                 return 0;
925
926         /* Tally the size only for each actual extraction of the stream (not
927          * additional hard links to the inode).  */
928         if (inode->i_visited && ctx->supported_features.hard_links)
929                 return 0;
930
931         ctx->progress.extract.total_bytes += blob->size;
932         ctx->progress.extract.total_streams++;
933
934         if (inode->i_visited)
935                 return 0;
936
937         /* Add each blob to 'ctx->blob_list' only one time, regardless of how
938          * many extraction targets it will have.  */
939         if (blob->out_refcnt == 0) {
940                 list_add_tail(&blob->extraction_list, &ctx->blob_list);
941                 ctx->num_blobs_remaining++;
942         }
943
944         /* Set this stream as an extraction target of 'blob'.  */
945
946         if (blob->out_refcnt < ARRAY_LEN(blob->inline_blob_extraction_targets)) {
947                 targets = blob->inline_blob_extraction_targets;
948         } else {
949                 struct blob_extraction_target *prev_targets;
950                 size_t alloc_blob_extraction_targets;
951
952                 if (blob->out_refcnt == ARRAY_LEN(blob->inline_blob_extraction_targets)) {
953                         prev_targets = NULL;
954                         alloc_blob_extraction_targets = ARRAY_LEN(blob->inline_blob_extraction_targets);
955                 } else {
956                         prev_targets = blob->blob_extraction_targets;
957                         alloc_blob_extraction_targets = blob->alloc_blob_extraction_targets;
958                 }
959
960                 if (blob->out_refcnt == alloc_blob_extraction_targets) {
961                         alloc_blob_extraction_targets *= 2;
962                         targets = REALLOC(prev_targets,
963                                           alloc_blob_extraction_targets *
964                                           sizeof(targets[0]));
965                         if (!targets)
966                                 return WIMLIB_ERR_NOMEM;
967                         if (!prev_targets) {
968                                 memcpy(targets,
969                                        blob->inline_blob_extraction_targets,
970                                        sizeof(blob->inline_blob_extraction_targets));
971                         }
972                         blob->blob_extraction_targets = targets;
973                         blob->alloc_blob_extraction_targets = alloc_blob_extraction_targets;
974                 }
975                 targets = blob->blob_extraction_targets;
976         }
977         targets[blob->out_refcnt].inode = inode;
978         targets[blob->out_refcnt].stream = strm;
979         blob->out_refcnt++;
980         return 0;
981 }
982
983 static int
984 ref_stream_if_needed(struct wim_dentry *dentry, struct wim_inode *inode,
985                      struct wim_inode_stream *strm, struct apply_ctx *ctx)
986 {
987         bool need_stream = false;
988         switch (strm->stream_type) {
989         case STREAM_TYPE_DATA:
990                 if (stream_is_named(strm)) {
991                         /* Named data stream  */
992                         if (ctx->supported_features.named_data_streams)
993                                 need_stream = true;
994                 } else if (!(inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
995                                                     FILE_ATTRIBUTE_ENCRYPTED))
996                            && !(inode_is_symlink(inode)
997                                 && !ctx->supported_features.reparse_points
998                                 && ctx->supported_features.symlink_reparse_points))
999                 {
1000                         /*
1001                          * Unnamed data stream.  Skip if any of the following is true:
1002                          *
1003                          * - file is a directory
1004                          * - file is encrypted
1005                          * - backend needs to create the file as UNIX symlink
1006                          * - backend will extract the stream as externally backed
1007                          */
1008                         if (ctx->apply_ops->will_externally_back) {
1009                                 int ret = (*ctx->apply_ops->will_externally_back)(dentry, ctx);
1010                                 if (ret > 0) /* Error?  */
1011                                         return ret;
1012                                 if (ret < 0) /* Won't externally back?  */
1013                                         need_stream = true;
1014                         } else {
1015                                 need_stream = true;
1016                         }
1017                 }
1018                 break;
1019         case STREAM_TYPE_REPARSE_POINT:
1020                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT);
1021                 if (ctx->supported_features.reparse_points ||
1022                     (inode_is_symlink(inode) &&
1023                      ctx->supported_features.symlink_reparse_points))
1024                         need_stream = true;
1025                 break;
1026         case STREAM_TYPE_EFSRPC_RAW_DATA:
1027                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED);
1028                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
1029                         if (ctx->supported_features.encrypted_directories)
1030                                 need_stream = true;
1031                 } else {
1032                         if (ctx->supported_features.encrypted_files)
1033                                 need_stream = true;
1034                 }
1035                 break;
1036         }
1037         if (need_stream)
1038                 return ref_stream(strm, dentry, ctx);
1039         return 0;
1040 }
1041
1042 static int
1043 dentry_ref_streams(struct wim_dentry *dentry, struct apply_ctx *ctx)
1044 {
1045         struct wim_inode *inode = dentry->d_inode;
1046         for (unsigned i = 0; i < inode->i_num_streams; i++) {
1047                 int ret = ref_stream_if_needed(dentry, inode,
1048                                                &inode->i_streams[i], ctx);
1049                 if (ret)
1050                         return ret;
1051         }
1052         inode->i_visited = 1;
1053         return 0;
1054 }
1055
1056 /*
1057  * Given a list of dentries to be extracted, build the list of blobs that need
1058  * to be extracted, and for each blob determine the streams to which that blob
1059  * will be extracted.
1060  *
1061  * This also initializes the extract progress info with byte and blob
1062  * information.
1063  *
1064  * ctx->supported_features must be filled in.
1065  */
1066 static int
1067 dentry_list_ref_streams(struct list_head *dentry_list, struct apply_ctx *ctx)
1068 {
1069         struct wim_dentry *dentry;
1070         int ret;
1071
1072         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1073                 ret = dentry_ref_streams(dentry, ctx);
1074                 if (ret)
1075                         return ret;
1076         }
1077         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1078                 dentry->d_inode->i_visited = 0;
1079         return 0;
1080 }
1081
1082 static void
1083 dentry_list_build_inode_alias_lists(struct list_head *dentry_list)
1084 {
1085         struct wim_dentry *dentry;
1086
1087         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1088                 dentry->d_inode->i_first_extraction_alias = NULL;
1089
1090         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1091                 dentry->d_next_extraction_alias = dentry->d_inode->i_first_extraction_alias;
1092                 dentry->d_inode->i_first_extraction_alias = dentry;
1093         }
1094 }
1095
1096 static void
1097 inode_tally_features(const struct wim_inode *inode,
1098                      struct wim_features *features)
1099 {
1100         if (inode->i_attributes & FILE_ATTRIBUTE_ARCHIVE)
1101                 features->archive_files++;
1102         if (inode->i_attributes & FILE_ATTRIBUTE_HIDDEN)
1103                 features->hidden_files++;
1104         if (inode->i_attributes & FILE_ATTRIBUTE_SYSTEM)
1105                 features->system_files++;
1106         if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED)
1107                 features->compressed_files++;
1108         if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
1109                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
1110                         features->encrypted_directories++;
1111                 else
1112                         features->encrypted_files++;
1113         }
1114         if (inode->i_attributes & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
1115                 features->not_context_indexed_files++;
1116         if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE)
1117                 features->sparse_files++;
1118         if (inode_has_named_data_stream(inode))
1119                 features->named_data_streams++;
1120         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1121                 features->reparse_points++;
1122                 if (inode_is_symlink(inode))
1123                         features->symlink_reparse_points++;
1124                 else
1125                         features->other_reparse_points++;
1126         }
1127         if (inode_has_security_descriptor(inode))
1128                 features->security_descriptors++;
1129         if (inode_has_unix_data(inode))
1130                 features->unix_data++;
1131 }
1132
1133 /* Tally features necessary to extract a dentry and the corresponding inode.  */
1134 static void
1135 dentry_tally_features(struct wim_dentry *dentry, struct wim_features *features)
1136 {
1137         struct wim_inode *inode = dentry->d_inode;
1138
1139         if (dentry_has_short_name(dentry))
1140                 features->short_names++;
1141
1142         if (inode->i_visited) {
1143                 features->hard_links++;
1144         } else {
1145                 inode_tally_features(inode, features);
1146                 inode->i_visited = 1;
1147         }
1148 }
1149
1150 /* Tally the features necessary to extract the specified dentries.  */
1151 static void
1152 dentry_list_get_features(struct list_head *dentry_list,
1153                          struct wim_features *features)
1154 {
1155         struct wim_dentry *dentry;
1156
1157         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1158                 dentry_tally_features(dentry, features);
1159
1160         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1161                 dentry->d_inode->i_visited = 0;
1162 }
1163
1164 static int
1165 do_feature_check(const struct wim_features *required_features,
1166                  const struct wim_features *supported_features,
1167                  int extract_flags)
1168 {
1169         /* Encrypted files.  */
1170         if (required_features->encrypted_files &&
1171             !supported_features->encrypted_files)
1172                 WARNING("Ignoring EFS-encrypted data of %lu files",
1173                         required_features->encrypted_files);
1174
1175         /* Named data streams.  */
1176         if (required_features->named_data_streams &&
1177             !supported_features->named_data_streams)
1178                 WARNING("Ignoring named data streams of %lu files",
1179                         required_features->named_data_streams);
1180
1181         /* File attributes.  */
1182         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
1183                 /* Note: Don't bother the user about FILE_ATTRIBUTE_ARCHIVE.
1184                  * We're an archive program, so theoretically we can do what we
1185                  * want with it.  */
1186
1187                 if (required_features->hidden_files &&
1188                     !supported_features->hidden_files)
1189                         WARNING("Ignoring FILE_ATTRIBUTE_HIDDEN of %lu files",
1190                                 required_features->hidden_files);
1191
1192                 if (required_features->system_files &&
1193                     !supported_features->system_files)
1194                         WARNING("Ignoring FILE_ATTRIBUTE_SYSTEM of %lu files",
1195                                 required_features->system_files);
1196
1197                 if (required_features->compressed_files &&
1198                     !supported_features->compressed_files)
1199                         WARNING("Ignoring FILE_ATTRIBUTE_COMPRESSED of %lu files",
1200                                 required_features->compressed_files);
1201
1202                 if (required_features->not_context_indexed_files &&
1203                     !supported_features->not_context_indexed_files)
1204                         WARNING("Ignoring FILE_ATTRIBUTE_NOT_CONTENT_INDEXED of %lu files",
1205                                 required_features->not_context_indexed_files);
1206
1207                 if (required_features->sparse_files &&
1208                     !supported_features->sparse_files)
1209                         WARNING("Ignoring FILE_ATTRIBUTE_SPARSE_FILE of %lu files",
1210                                 required_features->sparse_files);
1211
1212                 if (required_features->encrypted_directories &&
1213                     !supported_features->encrypted_directories)
1214                         WARNING("Ignoring FILE_ATTRIBUTE_ENCRYPTED of %lu directories",
1215                                 required_features->encrypted_directories);
1216         }
1217
1218         /* Hard links.  */
1219         if (required_features->hard_links && !supported_features->hard_links)
1220                 WARNING("Extracting %lu hard links as independent files",
1221                         required_features->hard_links);
1222
1223         /* Symbolic links and reparse points.  */
1224         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS) &&
1225             required_features->symlink_reparse_points &&
1226             !supported_features->symlink_reparse_points &&
1227             !supported_features->reparse_points)
1228         {
1229                 ERROR("Extraction backend does not support symbolic links!");
1230                 return WIMLIB_ERR_UNSUPPORTED;
1231         }
1232         if (required_features->reparse_points &&
1233             !supported_features->reparse_points)
1234         {
1235                 if (supported_features->symlink_reparse_points) {
1236                         if (required_features->other_reparse_points) {
1237                                 WARNING("Ignoring reparse data of %lu non-symlink/junction files",
1238                                         required_features->other_reparse_points);
1239                         }
1240                 } else {
1241                         WARNING("Ignoring reparse data of %lu files",
1242                                 required_features->reparse_points);
1243                 }
1244         }
1245
1246         /* Security descriptors.  */
1247         if (((extract_flags & (WIMLIB_EXTRACT_FLAG_STRICT_ACLS |
1248                                WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1249              == WIMLIB_EXTRACT_FLAG_STRICT_ACLS) &&
1250             required_features->security_descriptors &&
1251             !supported_features->security_descriptors)
1252         {
1253                 ERROR("Extraction backend does not support security descriptors!");
1254                 return WIMLIB_ERR_UNSUPPORTED;
1255         }
1256         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS) &&
1257             required_features->security_descriptors &&
1258             !supported_features->security_descriptors)
1259                 WARNING("Ignoring Windows NT security descriptors of %lu files",
1260                         required_features->security_descriptors);
1261
1262         /* UNIX data.  */
1263         if ((extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
1264             required_features->unix_data && !supported_features->unix_data)
1265         {
1266                 ERROR("Extraction backend does not support UNIX data!");
1267                 return WIMLIB_ERR_UNSUPPORTED;
1268         }
1269
1270         if (required_features->unix_data &&
1271             !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1272         {
1273                 WARNING("Ignoring UNIX metadata of %lu files",
1274                         required_features->unix_data);
1275         }
1276
1277         /* DOS Names.  */
1278         if (required_features->short_names &&
1279             !supported_features->short_names)
1280         {
1281                 if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES) {
1282                         ERROR("Extraction backend does not support DOS names!");
1283                         return WIMLIB_ERR_UNSUPPORTED;
1284                 }
1285                 WARNING("Ignoring DOS names of %lu files",
1286                         required_features->short_names);
1287         }
1288
1289         /* Timestamps.  */
1290         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) &&
1291             !supported_features->timestamps)
1292         {
1293                 ERROR("Extraction backend does not support timestamps!");
1294                 return WIMLIB_ERR_UNSUPPORTED;
1295         }
1296
1297         return 0;
1298 }
1299
1300 static const struct apply_operations *
1301 select_apply_operations(int extract_flags)
1302 {
1303 #ifdef WITH_NTFS_3G
1304         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
1305                 return &ntfs_3g_apply_ops;
1306 #endif
1307 #ifdef __WIN32__
1308         return &win32_apply_ops;
1309 #else
1310         return &unix_apply_ops;
1311 #endif
1312 }
1313
1314 static int
1315 extract_trees(WIMStruct *wim, struct wim_dentry **trees, size_t num_trees,
1316               const tchar *target, int extract_flags)
1317 {
1318         const struct apply_operations *ops;
1319         struct apply_ctx *ctx;
1320         int ret;
1321         LIST_HEAD(dentry_list);
1322
1323         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
1324                 ret = extract_dentries_to_stdout(trees, num_trees,
1325                                                  wim->blob_table);
1326                 goto out;
1327         }
1328
1329         num_trees = remove_duplicate_trees(trees, num_trees);
1330         num_trees = remove_contained_trees(trees, num_trees);
1331
1332         ops = select_apply_operations(extract_flags);
1333
1334         if (num_trees > 1 && ops->single_tree_only) {
1335                 ERROR("Extracting multiple directory trees "
1336                       "at once is not supported in %s extraction mode!",
1337                       ops->name);
1338                 ret = WIMLIB_ERR_UNSUPPORTED;
1339                 goto out;
1340         }
1341
1342         ctx = CALLOC(1, ops->context_size);
1343         if (!ctx) {
1344                 ret = WIMLIB_ERR_NOMEM;
1345                 goto out;
1346         }
1347
1348         ctx->wim = wim;
1349         ctx->target = target;
1350         ctx->target_nchars = tstrlen(target);
1351         ctx->extract_flags = extract_flags;
1352         if (ctx->wim->progfunc) {
1353                 ctx->progfunc = ctx->wim->progfunc;
1354                 ctx->progctx = ctx->wim->progctx;
1355                 ctx->progress.extract.image = wim->current_image;
1356                 ctx->progress.extract.extract_flags = (extract_flags &
1357                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
1358                 ctx->progress.extract.wimfile_name = wim->filename;
1359                 ctx->progress.extract.image_name = wimlib_get_image_name(wim,
1360                                                                          wim->current_image);
1361                 ctx->progress.extract.target = target;
1362         }
1363         INIT_LIST_HEAD(&ctx->blob_list);
1364         filedes_invalidate(&ctx->tmpfile_fd);
1365         ctx->apply_ops = ops;
1366
1367         ret = (*ops->get_supported_features)(target, &ctx->supported_features);
1368         if (ret)
1369                 goto out_cleanup;
1370
1371         build_dentry_list(&dentry_list, trees, num_trees,
1372                           !(extract_flags &
1373                             WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE));
1374
1375         dentry_list_get_features(&dentry_list, &ctx->required_features);
1376
1377         ret = do_feature_check(&ctx->required_features, &ctx->supported_features,
1378                                ctx->extract_flags);
1379         if (ret)
1380                 goto out_cleanup;
1381
1382         ret = dentry_list_calculate_extraction_names(&dentry_list, ctx);
1383         if (ret)
1384                 goto out_cleanup;
1385
1386         if (unlikely(list_empty(&dentry_list))) {
1387                 WARNING("There is nothing to extract!");
1388                 goto out_cleanup;
1389         }
1390
1391         ret = dentry_list_resolve_streams(&dentry_list, ctx);
1392         if (ret)
1393                 goto out_cleanup;
1394
1395         dentry_list_build_inode_alias_lists(&dentry_list);
1396
1397         ret = dentry_list_ref_streams(&dentry_list, ctx);
1398         if (ret)
1399                 goto out_cleanup;
1400
1401         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
1402                 /* When extracting from a pipe, the number of bytes of data to
1403                  * extract can't be determined in the normal way (examining the
1404                  * blob table), since at this point all we have is a set of
1405                  * SHA-1 message digests of blobs that need to be extracted.
1406                  * However, we can get a reasonably accurate estimate by taking
1407                  * <TOTALBYTES> from the corresponding <IMAGE> in the WIM XML
1408                  * data.  This does assume that a full image is being extracted,
1409                  * but currently there is no API for doing otherwise.  (Also,
1410                  * subtract <HARDLINKBYTES> from this if hard links are
1411                  * supported by the extraction mode.)  */
1412                 ctx->progress.extract.total_bytes =
1413                         wim_info_get_image_total_bytes(wim->wim_info,
1414                                                        wim->current_image);
1415                 if (ctx->supported_features.hard_links) {
1416                         ctx->progress.extract.total_bytes -=
1417                                 wim_info_get_image_hard_link_bytes(wim->wim_info,
1418                                                                    wim->current_image);
1419                 }
1420         }
1421
1422         ret = extract_progress(ctx,
1423                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1424                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN :
1425                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN));
1426         if (ret)
1427                 goto out_cleanup;
1428
1429         ret = (*ops->extract)(&dentry_list, ctx);
1430         if (ret)
1431                 goto out_cleanup;
1432
1433         if (ctx->progress.extract.completed_bytes <
1434             ctx->progress.extract.total_bytes)
1435         {
1436                 ctx->progress.extract.completed_bytes =
1437                         ctx->progress.extract.total_bytes;
1438                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
1439                 if (ret)
1440                         goto out_cleanup;
1441         }
1442
1443         ret = extract_progress(ctx,
1444                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1445                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END :
1446                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END));
1447 out_cleanup:
1448         destroy_blob_list(&ctx->blob_list);
1449         destroy_dentry_list(&dentry_list);
1450         FREE(ctx);
1451 out:
1452         return ret;
1453 }
1454
1455 static int
1456 mkdir_if_needed(const tchar *target)
1457 {
1458         if (!tmkdir(target, 0755))
1459                 return 0;
1460
1461         if (errno == EEXIST)
1462                 return 0;
1463
1464 #ifdef __WIN32__
1465         /* _wmkdir() fails with EACCES if called on a drive root directory.  */
1466         if (errno == EACCES)
1467                 return 0;
1468 #endif
1469
1470         ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
1471         return WIMLIB_ERR_MKDIR;
1472 }
1473
1474 /* Make sure the extraction flags make sense, and update them if needed.  */
1475 static int
1476 check_extract_flags(const WIMStruct *wim, int *extract_flags_p)
1477 {
1478         int extract_flags = *extract_flags_p;
1479
1480         /* Check for invalid flag combinations  */
1481
1482         if ((extract_flags &
1483              (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1484               WIMLIB_EXTRACT_FLAG_STRICT_ACLS)) == (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1485                                                     WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
1486                 return WIMLIB_ERR_INVALID_PARAM;
1487
1488         if ((extract_flags &
1489              (WIMLIB_EXTRACT_FLAG_RPFIX |
1490               WIMLIB_EXTRACT_FLAG_NORPFIX)) == (WIMLIB_EXTRACT_FLAG_RPFIX |
1491                                                 WIMLIB_EXTRACT_FLAG_NORPFIX))
1492                 return WIMLIB_ERR_INVALID_PARAM;
1493
1494 #ifndef WITH_NTFS_3G
1495         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1496                 ERROR("wimlib was compiled without support for NTFS-3g, so\n"
1497                       "        it cannot apply a WIM image directly to an NTFS volume.");
1498                 return WIMLIB_ERR_UNSUPPORTED;
1499         }
1500 #endif
1501
1502         if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
1503 #ifdef __WIN32__
1504                 if (!wim->filename)
1505                         return WIMLIB_ERR_NO_FILENAME;
1506 #else
1507                 ERROR("WIMBoot extraction is only supported on Windows!");
1508                 return WIMLIB_ERR_UNSUPPORTED;
1509 #endif
1510         }
1511
1512
1513         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
1514                               WIMLIB_EXTRACT_FLAG_NORPFIX |
1515                               WIMLIB_EXTRACT_FLAG_IMAGEMODE)) ==
1516                                         WIMLIB_EXTRACT_FLAG_IMAGEMODE)
1517         {
1518                 /* For full-image extraction, do reparse point fixups by default
1519                  * if the WIM header says they are enabled.  */
1520                 if (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
1521                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
1522         }
1523
1524         *extract_flags_p = extract_flags;
1525         return 0;
1526 }
1527
1528 static u32
1529 get_wildcard_flags(int extract_flags)
1530 {
1531         u32 wildcard_flags = 0;
1532
1533         if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_GLOB)
1534                 wildcard_flags |= WILDCARD_FLAG_ERROR_IF_NO_MATCH;
1535         else
1536                 wildcard_flags |= WILDCARD_FLAG_WARN_IF_NO_MATCH;
1537
1538         if (default_ignore_case)
1539                 wildcard_flags |= WILDCARD_FLAG_CASE_INSENSITIVE;
1540
1541         return wildcard_flags;
1542 }
1543
1544 struct append_dentry_ctx {
1545         struct wim_dentry **dentries;
1546         size_t num_dentries;
1547         size_t num_alloc_dentries;
1548 };
1549
1550 static int
1551 append_dentry_cb(struct wim_dentry *dentry, void *_ctx)
1552 {
1553         struct append_dentry_ctx *ctx = _ctx;
1554
1555         if (ctx->num_dentries == ctx->num_alloc_dentries) {
1556                 struct wim_dentry **new_dentries;
1557                 size_t new_length;
1558
1559                 new_length = max(ctx->num_alloc_dentries + 8,
1560                                  ctx->num_alloc_dentries * 3 / 2);
1561                 new_dentries = REALLOC(ctx->dentries,
1562                                        new_length * sizeof(ctx->dentries[0]));
1563                 if (new_dentries == NULL)
1564                         return WIMLIB_ERR_NOMEM;
1565                 ctx->dentries = new_dentries;
1566                 ctx->num_alloc_dentries = new_length;
1567         }
1568         ctx->dentries[ctx->num_dentries++] = dentry;
1569         return 0;
1570 }
1571
1572 static int
1573 do_wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1574                         const tchar * const *paths, size_t num_paths,
1575                         int extract_flags)
1576 {
1577         int ret;
1578         struct wim_dentry **trees;
1579         size_t num_trees;
1580
1581         if (wim == NULL || target == NULL || target[0] == T('\0') ||
1582             (num_paths != 0 && paths == NULL))
1583                 return WIMLIB_ERR_INVALID_PARAM;
1584
1585         ret = check_extract_flags(wim, &extract_flags);
1586         if (ret)
1587                 return ret;
1588
1589         ret = select_wim_image(wim, image);
1590         if (ret)
1591                 return ret;
1592
1593         ret = wim_checksum_unhashed_blobs(wim);
1594         if (ret)
1595                 return ret;
1596
1597         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_NTFS |
1598                               WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE)) ==
1599             (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE))
1600         {
1601                 ret = mkdir_if_needed(target);
1602                 if (ret)
1603                         return ret;
1604         }
1605
1606         if (extract_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {
1607
1608                 struct append_dentry_ctx append_dentry_ctx = {
1609                         .dentries = NULL,
1610                         .num_dentries = 0,
1611                         .num_alloc_dentries = 0,
1612                 };
1613
1614                 u32 wildcard_flags = get_wildcard_flags(extract_flags);
1615
1616                 for (size_t i = 0; i < num_paths; i++) {
1617                         tchar *path = canonicalize_wim_path(paths[i]);
1618                         if (path == NULL) {
1619                                 ret = WIMLIB_ERR_NOMEM;
1620                                 trees = append_dentry_ctx.dentries;
1621                                 goto out_free_trees;
1622                         }
1623                         ret = expand_wildcard(wim, path,
1624                                               append_dentry_cb,
1625                                               &append_dentry_ctx,
1626                                               wildcard_flags);
1627                         FREE(path);
1628                         if (ret) {
1629                                 trees = append_dentry_ctx.dentries;
1630                                 goto out_free_trees;
1631                         }
1632                 }
1633                 trees = append_dentry_ctx.dentries;
1634                 num_trees = append_dentry_ctx.num_dentries;
1635         } else {
1636                 trees = MALLOC(num_paths * sizeof(trees[0]));
1637                 if (trees == NULL)
1638                         return WIMLIB_ERR_NOMEM;
1639
1640                 for (size_t i = 0; i < num_paths; i++) {
1641
1642                         tchar *path = canonicalize_wim_path(paths[i]);
1643                         if (path == NULL) {
1644                                 ret = WIMLIB_ERR_NOMEM;
1645                                 goto out_free_trees;
1646                         }
1647
1648                         trees[i] = get_dentry(wim, path,
1649                                               WIMLIB_CASE_PLATFORM_DEFAULT);
1650                         FREE(path);
1651                         if (trees[i] == NULL) {
1652                                   ERROR("Path \"%"TS"\" does not exist "
1653                                         "in WIM image %d",
1654                                         paths[i], wim->current_image);
1655                                   ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1656                                   goto out_free_trees;
1657                         }
1658                 }
1659                 num_trees = num_paths;
1660         }
1661
1662         if (num_trees == 0) {
1663                 ret = 0;
1664                 goto out_free_trees;
1665         }
1666
1667         ret = extract_trees(wim, trees, num_trees, target, extract_flags);
1668 out_free_trees:
1669         FREE(trees);
1670         return ret;
1671 }
1672
1673 static int
1674 extract_single_image(WIMStruct *wim, int image,
1675                      const tchar *target, int extract_flags)
1676 {
1677         const tchar *path = WIMLIB_WIM_ROOT_PATH;
1678         extract_flags |= WIMLIB_EXTRACT_FLAG_IMAGEMODE;
1679         return do_wimlib_extract_paths(wim, image, target, &path, 1, extract_flags);
1680 }
1681
1682 static const tchar * const filename_forbidden_chars =
1683 T(
1684 #ifdef __WIN32__
1685 "<>:\"/\\|?*"
1686 #else
1687 "/"
1688 #endif
1689 );
1690
1691 /* This function checks if it is okay to use a WIM image's name as a directory
1692  * name.  */
1693 static bool
1694 image_name_ok_as_dir(const tchar *image_name)
1695 {
1696         return image_name && *image_name &&
1697                 !tstrpbrk(image_name, filename_forbidden_chars) &&
1698                 tstrcmp(image_name, T(".")) &&
1699                 tstrcmp(image_name, T(".."));
1700 }
1701
1702 /* Extracts all images from the WIM to the directory @target, with the images
1703  * placed in subdirectories named by their image names. */
1704 static int
1705 extract_all_images(WIMStruct *wim, const tchar *target, int extract_flags)
1706 {
1707         size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
1708         size_t output_path_len = tstrlen(target);
1709         tchar buf[output_path_len + 1 + image_name_max_len + 1];
1710         int ret;
1711         int image;
1712         const tchar *image_name;
1713
1714         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1715                 ERROR("Cannot extract multiple images in NTFS extraction mode.");
1716                 return WIMLIB_ERR_INVALID_PARAM;
1717         }
1718
1719         ret = mkdir_if_needed(target);
1720         if (ret)
1721                 return ret;
1722         tmemcpy(buf, target, output_path_len);
1723         buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
1724         for (image = 1; image <= wim->hdr.image_count; image++) {
1725                 image_name = wimlib_get_image_name(wim, image);
1726                 if (image_name_ok_as_dir(image_name)) {
1727                         tstrcpy(buf + output_path_len + 1, image_name);
1728                 } else {
1729                         /* Image name is empty or contains forbidden characters.
1730                          * Use image number instead. */
1731                         tsprintf(buf + output_path_len + 1, T("%d"), image);
1732                 }
1733                 ret = extract_single_image(wim, image, buf, extract_flags);
1734                 if (ret)
1735                         return ret;
1736         }
1737         return 0;
1738 }
1739
1740 static int
1741 do_wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1742                         int extract_flags)
1743 {
1744         if (extract_flags & (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
1745                              WIMLIB_EXTRACT_FLAG_TO_STDOUT |
1746                              WIMLIB_EXTRACT_FLAG_GLOB_PATHS))
1747                 return WIMLIB_ERR_INVALID_PARAM;
1748
1749         if (image == WIMLIB_ALL_IMAGES)
1750                 return extract_all_images(wim, target, extract_flags);
1751         else
1752                 return extract_single_image(wim, image, target, extract_flags);
1753 }
1754
1755
1756 /****************************************************************************
1757  *                          Extraction API                                  *
1758  ****************************************************************************/
1759
1760 WIMLIBAPI int
1761 wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1762                      const tchar * const *paths, size_t num_paths,
1763                      int extract_flags)
1764 {
1765         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1766                 return WIMLIB_ERR_INVALID_PARAM;
1767
1768         return do_wimlib_extract_paths(wim, image, target, paths, num_paths,
1769                                        extract_flags);
1770 }
1771
1772 WIMLIBAPI int
1773 wimlib_extract_pathlist(WIMStruct *wim, int image, const tchar *target,
1774                         const tchar *path_list_file, int extract_flags)
1775 {
1776         int ret;
1777         tchar **paths;
1778         size_t num_paths;
1779         void *mem;
1780
1781         ret = read_path_list_file(path_list_file, &paths, &num_paths, &mem);
1782         if (ret) {
1783                 ERROR("Failed to read path list file \"%"TS"\"",
1784                       path_list_file);
1785                 return ret;
1786         }
1787
1788         ret = wimlib_extract_paths(wim, image, target,
1789                                    (const tchar * const *)paths, num_paths,
1790                                    extract_flags);
1791         FREE(paths);
1792         FREE(mem);
1793         return ret;
1794 }
1795
1796 WIMLIBAPI int
1797 wimlib_extract_image_from_pipe_with_progress(int pipe_fd,
1798                                              const tchar *image_num_or_name,
1799                                              const tchar *target,
1800                                              int extract_flags,
1801                                              wimlib_progress_func_t progfunc,
1802                                              void *progctx)
1803 {
1804         int ret;
1805         WIMStruct *pwm;
1806         struct filedes *in_fd;
1807         int image;
1808         unsigned i;
1809
1810         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1811                 return WIMLIB_ERR_INVALID_PARAM;
1812
1813         /* Read the WIM header from the pipe and get a WIMStruct to represent
1814          * the pipable WIM.  Caveats:  Unlike getting a WIMStruct with
1815          * wimlib_open_wim(), getting a WIMStruct in this way will result in an
1816          * empty blob table, no XML data read, and no filename set.  */
1817         ret = open_wim_as_WIMStruct(&pipe_fd, WIMLIB_OPEN_FLAG_FROM_PIPE, &pwm,
1818                                     progfunc, progctx);
1819         if (ret)
1820                 return ret;
1821
1822         /* Sanity check to make sure this is a pipable WIM.  */
1823         if (pwm->hdr.magic != PWM_MAGIC) {
1824                 ERROR("The WIM being read from file descriptor %d "
1825                       "is not pipable!", pipe_fd);
1826                 ret = WIMLIB_ERR_NOT_PIPABLE;
1827                 goto out_wimlib_free;
1828         }
1829
1830         /* Sanity check to make sure the first part of a pipable split WIM is
1831          * sent over the pipe first.  */
1832         if (pwm->hdr.part_number != 1) {
1833                 ERROR("The first part of the split WIM must be "
1834                       "sent over the pipe first.");
1835                 ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1836                 goto out_wimlib_free;
1837         }
1838
1839         in_fd = &pwm->in_fd;
1840         wimlib_assert(in_fd->offset == WIM_HEADER_DISK_SIZE);
1841
1842         /* As mentioned, the WIMStruct we created from the pipe does not have
1843          * XML data yet.  Fix this by reading the extra copy of the XML data
1844          * that directly follows the header in pipable WIMs.  (Note: see
1845          * write_pipable_wim() for more details about the format of pipable
1846          * WIMs.)  */
1847         {
1848                 u8 hash[SHA1_HASH_SIZE];
1849
1850                 ret = read_pwm_blob_header(pwm, hash,
1851                                            &pwm->hdr.xml_data_reshdr, NULL);
1852                 if (ret)
1853                         goto out_wimlib_free;
1854
1855                 if (!(pwm->hdr.xml_data_reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1856                         ERROR("Expected XML data, but found non-metadata resource.");
1857                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1858                         goto out_wimlib_free;
1859                 }
1860
1861                 ret = read_wim_xml_data(pwm);
1862                 if (ret)
1863                         goto out_wimlib_free;
1864
1865                 if (wim_info_get_num_images(pwm->wim_info) != pwm->hdr.image_count) {
1866                         ERROR("Image count in XML data is not the same as in WIM header.");
1867                         ret = WIMLIB_ERR_IMAGE_COUNT;
1868                         goto out_wimlib_free;
1869                 }
1870         }
1871
1872         /* Get image index (this may use the XML data that was just read to
1873          * resolve an image name).  */
1874         if (image_num_or_name) {
1875                 image = wimlib_resolve_image(pwm, image_num_or_name);
1876                 if (image == WIMLIB_NO_IMAGE) {
1877                         ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
1878                               image_num_or_name);
1879                         ret = WIMLIB_ERR_INVALID_IMAGE;
1880                         goto out_wimlib_free;
1881                 } else if (image == WIMLIB_ALL_IMAGES) {
1882                         ERROR("Applying all images from a pipe is not supported!");
1883                         ret = WIMLIB_ERR_INVALID_IMAGE;
1884                         goto out_wimlib_free;
1885                 }
1886         } else {
1887                 if (pwm->hdr.image_count != 1) {
1888                         ERROR("No image was specified, but the pipable WIM "
1889                               "did not contain exactly 1 image");
1890                         ret = WIMLIB_ERR_INVALID_IMAGE;
1891                         goto out_wimlib_free;
1892                 }
1893                 image = 1;
1894         }
1895
1896         /* Load the needed metadata resource.  */
1897         for (i = 1; i <= pwm->hdr.image_count; i++) {
1898                 struct wim_image_metadata *imd;
1899                 struct wim_reshdr reshdr;
1900                 struct wim_resource_descriptor *metadata_rdesc;
1901
1902                 imd = pwm->image_metadata[i - 1];
1903
1904                 ret = WIMLIB_ERR_NOMEM;
1905                 imd->metadata_blob = new_blob_descriptor();
1906                 if (!imd->metadata_blob)
1907                         goto out_wimlib_free;
1908
1909                 imd->metadata_blob->is_metadata = 1;
1910
1911                 ret = read_pwm_blob_header(pwm, imd->metadata_blob->hash,
1912                                            &reshdr, NULL);
1913                 if (ret)
1914                         goto out_wimlib_free;
1915
1916                 if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1917                         ERROR("Expected metadata resource, but found "
1918                               "non-metadata resource");
1919                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1920                         goto out_wimlib_free;
1921                 }
1922
1923                 ret = WIMLIB_ERR_NOMEM;
1924                 metadata_rdesc = MALLOC(sizeof(struct wim_resource_descriptor));
1925                 if (!metadata_rdesc)
1926                         goto out_wimlib_free;
1927                 wim_reshdr_to_desc_and_blob(&reshdr, pwm, metadata_rdesc,
1928                                             imd->metadata_blob);
1929
1930                 if (i == image) {
1931                         /* Metadata resource is for the image being extracted.
1932                          * Parse it and save the metadata in memory.  */
1933                         ret = read_metadata_resource(imd);
1934                         if (ret)
1935                                 goto out_wimlib_free;
1936                         imd->modified = 1;
1937                 } else {
1938                         /* Metadata resource is not for the image being
1939                          * extracted.  Skip over it.  */
1940                         ret = skip_wim_resource(metadata_rdesc);
1941                         if (ret)
1942                                 goto out_wimlib_free;
1943                 }
1944         }
1945         /* Extract the image.  */
1946         extract_flags |= WIMLIB_EXTRACT_FLAG_FROM_PIPE;
1947         ret = do_wimlib_extract_image(pwm, image, target, extract_flags);
1948         /* Clean up and return.  */
1949 out_wimlib_free:
1950         wimlib_free(pwm);
1951         return ret;
1952 }
1953
1954
1955 WIMLIBAPI int
1956 wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
1957                                const tchar *target, int extract_flags)
1958 {
1959         return wimlib_extract_image_from_pipe_with_progress(pipe_fd,
1960                                                             image_num_or_name,
1961                                                             target,
1962                                                             extract_flags,
1963                                                             NULL,
1964                                                             NULL);
1965 }
1966
1967 WIMLIBAPI int
1968 wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1969                      int extract_flags)
1970 {
1971         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1972                 return WIMLIB_ERR_INVALID_PARAM;
1973         return do_wimlib_extract_image(wim, image, target, extract_flags);
1974 }