6b35a90367d0b106a9a0152804481c47c27c24e1
[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 (name[i]) {
659         #ifdef __WIN32__
660                 case cpu_to_le16('\\'):
661                 case cpu_to_le16(':'):
662                 case cpu_to_le16('*'):
663                 case cpu_to_le16('?'):
664                 case cpu_to_le16('"'):
665                 case cpu_to_le16('<'):
666                 case cpu_to_le16('>'):
667                 case cpu_to_le16('|'):
668         #endif
669                 case cpu_to_le16('/'):
670                 case cpu_to_le16('\0'):
671                         if (fix)
672                                 name[i] = replacement_char;
673                         else
674                                 return false;
675                 }
676         }
677
678 #ifdef __WIN32__
679         if (name[num_chars - 1] == cpu_to_le16(' ') ||
680             name[num_chars - 1] == cpu_to_le16('.'))
681         {
682                 if (fix)
683                         name[num_chars - 1] = replacement_char;
684                 else
685                         return false;
686         }
687 #endif
688         return true;
689 }
690
691 static int
692 dentry_calculate_extraction_name(struct wim_dentry *dentry,
693                                  struct apply_ctx *ctx)
694 {
695         int ret;
696
697         if (dentry_is_root(dentry))
698                 return 0;
699
700 #ifdef WITH_NTFS_3G
701         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
702                 dentry->d_extraction_name = dentry->d_name;
703                 dentry->d_extraction_name_nchars = dentry->d_name_nbytes /
704                                                    sizeof(utf16lechar);
705                 return 0;
706         }
707 #endif
708
709         if (!ctx->supported_features.case_sensitive_filenames) {
710                 struct wim_dentry *other;
711                 list_for_each_entry(other, &dentry->d_ci_conflict_list,
712                                     d_ci_conflict_list)
713                 {
714                         if (will_extract_dentry(other)) {
715                                 if (ctx->extract_flags &
716                                     WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS) {
717                                         WARNING("\"%"TS"\" has the same "
718                                                 "case-insensitive name as "
719                                                 "\"%"TS"\"; extracting "
720                                                 "dummy name instead",
721                                                 dentry_full_path(dentry),
722                                                 dentry_full_path(other));
723                                         goto out_replace;
724                                 } else {
725                                         WARNING("Not extracting \"%"TS"\": "
726                                                 "has same case-insensitive "
727                                                 "name as \"%"TS"\"",
728                                                 dentry_full_path(dentry),
729                                                 dentry_full_path(other));
730                                         goto skip_dentry;
731                                 }
732                         }
733                 }
734         }
735
736         if (file_name_valid(dentry->d_name, dentry->d_name_nbytes / 2, false)) {
737                 size_t nbytes = 0;
738                 ret = utf16le_get_tstr(dentry->d_name,
739                                        dentry->d_name_nbytes,
740                                        (const tchar **)&dentry->d_extraction_name,
741                                        &nbytes);
742                 dentry->d_extraction_name_nchars = nbytes / sizeof(tchar);
743                 return ret;
744         } else {
745                 if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
746                 {
747                         WARNING("\"%"TS"\" has an invalid filename "
748                                 "that is not supported on this platform; "
749                                 "extracting dummy name instead",
750                                 dentry_full_path(dentry));
751                         goto out_replace;
752                 } else {
753                         WARNING("Not extracting \"%"TS"\": has an invalid filename "
754                                 "that is not supported on this platform",
755                                 dentry_full_path(dentry));
756                         goto skip_dentry;
757                 }
758         }
759
760 out_replace:
761         {
762                 utf16lechar utf16_name_copy[dentry->d_name_nbytes / 2];
763
764                 memcpy(utf16_name_copy, dentry->d_name, dentry->d_name_nbytes);
765                 file_name_valid(utf16_name_copy, dentry->d_name_nbytes / 2, true);
766
767                 const tchar *tchar_name;
768                 size_t tchar_nchars;
769
770                 ret = utf16le_get_tstr(utf16_name_copy,
771                                        dentry->d_name_nbytes,
772                                        &tchar_name, &tchar_nchars);
773                 if (ret)
774                         return ret;
775
776                 tchar_nchars /= sizeof(tchar);
777
778                 size_t fixed_name_num_chars = tchar_nchars;
779                 tchar fixed_name[tchar_nchars + 50];
780
781                 tmemcpy(fixed_name, tchar_name, tchar_nchars);
782                 fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
783                                                  T(" (invalid filename #%lu)"),
784                                                  ++ctx->invalid_sequence);
785
786                 utf16le_put_tstr(tchar_name);
787
788                 dentry->d_extraction_name = TSTRDUP(fixed_name);
789                 if (!dentry->d_extraction_name)
790                         return WIMLIB_ERR_NOMEM;
791                 dentry->d_extraction_name_nchars = fixed_name_num_chars;
792         }
793         return 0;
794
795 skip_dentry:
796         for_dentry_in_tree(dentry, dentry_delete_from_list, NULL);
797         return 0;
798 }
799
800 /*
801  * Calculate the actual filename component at which each WIM dentry will be
802  * extracted, with special handling for dentries that are unsupported by the
803  * extraction backend or have invalid names.
804  *
805  * ctx->supported_features must be filled in.
806  *
807  * Possible error codes: WIMLIB_ERR_NOMEM, WIMLIB_ERR_INVALID_UTF16_STRING
808  */
809 static int
810 dentry_list_calculate_extraction_names(struct list_head *dentry_list,
811                                        struct apply_ctx *ctx)
812 {
813         struct list_head *prev, *cur;
814
815         /* Can't use list_for_each_entry() because a call to
816          * dentry_calculate_extraction_name() may delete the current dentry and
817          * its children from the list.  */
818
819         prev = dentry_list;
820         for (;;) {
821                 struct wim_dentry *dentry;
822                 int ret;
823
824                 cur = prev->next;
825                 if (cur == dentry_list)
826                         break;
827
828                 dentry = list_entry(cur, struct wim_dentry, d_extraction_list_node);
829
830                 ret = dentry_calculate_extraction_name(dentry, ctx);
831                 if (ret)
832                         return ret;
833
834                 if (prev->next == cur)
835                         prev = cur;
836                 else
837                         ; /* Current dentry and its children (which follow in
838                              the list) were deleted.  prev stays the same.  */
839         }
840         return 0;
841 }
842
843 static int
844 dentry_resolve_streams(struct wim_dentry *dentry, int extract_flags,
845                        struct blob_table *blob_table)
846 {
847         struct wim_inode *inode = dentry->d_inode;
848         struct blob_descriptor *blob;
849         int ret;
850         bool force = false;
851
852         /* Special case:  when extracting from a pipe, the WIM blob table is
853          * initially empty, so "resolving" an inode's streams is initially not
854          * possible.  However, we still need to keep track of which blobs,
855          * identified by SHA-1 message digests, need to be extracted, so we
856          * "resolve" the inode's streams anyway by allocating a 'struct
857          * blob_descriptor' for each one.  */
858         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
859                 force = true;
860         ret = inode_resolve_streams(inode, blob_table, force);
861         if (ret)
862                 return ret;
863         for (unsigned i = 0; i < inode->i_num_streams; i++) {
864                 blob = stream_blob_resolved(&inode->i_streams[i]);
865                 if (blob)
866                         blob->out_refcnt = 0;
867         }
868         return 0;
869 }
870
871 /*
872  * For each dentry to be extracted, resolve all streams in the corresponding
873  * inode and set 'out_refcnt' in all referenced blob_descriptors to 0.
874  *
875  * Possible error codes: WIMLIB_ERR_RESOURCE_NOT_FOUND, WIMLIB_ERR_NOMEM.
876  */
877 static int
878 dentry_list_resolve_streams(struct list_head *dentry_list,
879                             struct apply_ctx *ctx)
880 {
881         struct wim_dentry *dentry;
882         int ret;
883
884         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
885                 ret = dentry_resolve_streams(dentry,
886                                              ctx->extract_flags,
887                                              ctx->wim->blob_table);
888                 if (ret)
889                         return ret;
890         }
891         return 0;
892 }
893
894 static int
895 ref_stream(struct wim_inode_stream *strm, struct wim_dentry *dentry,
896            struct apply_ctx *ctx)
897 {
898         struct wim_inode *inode = dentry->d_inode;
899         struct blob_descriptor *blob = stream_blob_resolved(strm);
900         struct blob_extraction_target *targets;
901
902         if (!blob)
903                 return 0;
904
905         /* Tally the size only for each actual extraction of the stream (not
906          * additional hard links to the inode).  */
907         if (inode->i_visited && ctx->supported_features.hard_links)
908                 return 0;
909
910         ctx->progress.extract.total_bytes += blob->size;
911         ctx->progress.extract.total_streams++;
912
913         if (inode->i_visited)
914                 return 0;
915
916         /* Add each blob to 'ctx->blob_list' only one time, regardless of how
917          * many extraction targets it will have.  */
918         if (blob->out_refcnt == 0) {
919                 list_add_tail(&blob->extraction_list, &ctx->blob_list);
920                 ctx->num_blobs_remaining++;
921         }
922
923         /* Set this stream as an extraction target of 'blob'.  */
924
925         if (blob->out_refcnt < ARRAY_LEN(blob->inline_blob_extraction_targets)) {
926                 targets = blob->inline_blob_extraction_targets;
927         } else {
928                 struct blob_extraction_target *prev_targets;
929                 size_t alloc_blob_extraction_targets;
930
931                 if (blob->out_refcnt == ARRAY_LEN(blob->inline_blob_extraction_targets)) {
932                         prev_targets = NULL;
933                         alloc_blob_extraction_targets = ARRAY_LEN(blob->inline_blob_extraction_targets);
934                 } else {
935                         prev_targets = blob->blob_extraction_targets;
936                         alloc_blob_extraction_targets = blob->alloc_blob_extraction_targets;
937                 }
938
939                 if (blob->out_refcnt == alloc_blob_extraction_targets) {
940                         alloc_blob_extraction_targets *= 2;
941                         targets = REALLOC(prev_targets,
942                                           alloc_blob_extraction_targets *
943                                           sizeof(targets[0]));
944                         if (!targets)
945                                 return WIMLIB_ERR_NOMEM;
946                         if (!prev_targets) {
947                                 memcpy(targets,
948                                        blob->inline_blob_extraction_targets,
949                                        sizeof(blob->inline_blob_extraction_targets));
950                         }
951                         blob->blob_extraction_targets = targets;
952                         blob->alloc_blob_extraction_targets = alloc_blob_extraction_targets;
953                 }
954                 targets = blob->blob_extraction_targets;
955         }
956         targets[blob->out_refcnt].inode = inode;
957         targets[blob->out_refcnt].stream = strm;
958         blob->out_refcnt++;
959         return 0;
960 }
961
962 static int
963 ref_stream_if_needed(struct wim_dentry *dentry, struct wim_inode *inode,
964                      struct wim_inode_stream *strm, struct apply_ctx *ctx)
965 {
966         bool need_stream = false;
967         switch (strm->stream_type) {
968         case STREAM_TYPE_DATA:
969                 if (stream_is_named(strm)) {
970                         /* Named data stream  */
971                         if (ctx->supported_features.named_data_streams)
972                                 need_stream = true;
973                 } else if (!(inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
974                                                     FILE_ATTRIBUTE_ENCRYPTED))
975                            && !(inode_is_symlink(inode)
976                                 && !ctx->supported_features.reparse_points
977                                 && ctx->supported_features.symlink_reparse_points))
978                 {
979                         /*
980                          * Unnamed data stream.  Skip if any of the following is true:
981                          *
982                          * - file is a directory
983                          * - file is encrypted
984                          * - backend needs to create the file as UNIX symlink
985                          * - backend will extract the stream as externally backed
986                          */
987                         if (ctx->apply_ops->will_externally_back) {
988                                 int ret = (*ctx->apply_ops->will_externally_back)(dentry, ctx);
989                                 if (ret > 0) /* Error?  */
990                                         return ret;
991                                 if (ret < 0) /* Won't externally back?  */
992                                         need_stream = true;
993                         } else {
994                                 need_stream = true;
995                         }
996                 }
997                 break;
998         case STREAM_TYPE_REPARSE_POINT:
999                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT);
1000                 if (ctx->supported_features.reparse_points ||
1001                     (inode_is_symlink(inode) &&
1002                      ctx->supported_features.symlink_reparse_points))
1003                         need_stream = true;
1004                 break;
1005         case STREAM_TYPE_EFSRPC_RAW_DATA:
1006                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED);
1007                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
1008                         if (ctx->supported_features.encrypted_directories)
1009                                 need_stream = true;
1010                 } else {
1011                         if (ctx->supported_features.encrypted_files)
1012                                 need_stream = true;
1013                 }
1014                 break;
1015         }
1016         if (need_stream)
1017                 return ref_stream(strm, dentry, ctx);
1018         return 0;
1019 }
1020
1021 static int
1022 dentry_ref_streams(struct wim_dentry *dentry, struct apply_ctx *ctx)
1023 {
1024         struct wim_inode *inode = dentry->d_inode;
1025         for (unsigned i = 0; i < inode->i_num_streams; i++) {
1026                 int ret = ref_stream_if_needed(dentry, inode,
1027                                                &inode->i_streams[i], ctx);
1028                 if (ret)
1029                         return ret;
1030         }
1031         inode->i_visited = 1;
1032         return 0;
1033 }
1034
1035 /*
1036  * Given a list of dentries to be extracted, build the list of blobs that need
1037  * to be extracted, and for each blob determine the streams to which that blob
1038  * will be extracted.
1039  *
1040  * This also initializes the extract progress info with byte and blob
1041  * information.
1042  *
1043  * ctx->supported_features must be filled in.
1044  */
1045 static int
1046 dentry_list_ref_streams(struct list_head *dentry_list, struct apply_ctx *ctx)
1047 {
1048         struct wim_dentry *dentry;
1049         int ret;
1050
1051         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1052                 ret = dentry_ref_streams(dentry, ctx);
1053                 if (ret)
1054                         return ret;
1055         }
1056         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1057                 dentry->d_inode->i_visited = 0;
1058         return 0;
1059 }
1060
1061 static void
1062 dentry_list_build_inode_alias_lists(struct list_head *dentry_list)
1063 {
1064         struct wim_dentry *dentry;
1065
1066         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1067                 dentry->d_inode->i_first_extraction_alias = NULL;
1068
1069         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1070                 dentry->d_next_extraction_alias = dentry->d_inode->i_first_extraction_alias;
1071                 dentry->d_inode->i_first_extraction_alias = dentry;
1072         }
1073 }
1074
1075 static void
1076 inode_tally_features(const struct wim_inode *inode,
1077                      struct wim_features *features)
1078 {
1079         if (inode->i_attributes & FILE_ATTRIBUTE_ARCHIVE)
1080                 features->archive_files++;
1081         if (inode->i_attributes & FILE_ATTRIBUTE_HIDDEN)
1082                 features->hidden_files++;
1083         if (inode->i_attributes & FILE_ATTRIBUTE_SYSTEM)
1084                 features->system_files++;
1085         if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED)
1086                 features->compressed_files++;
1087         if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
1088                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
1089                         features->encrypted_directories++;
1090                 else
1091                         features->encrypted_files++;
1092         }
1093         if (inode->i_attributes & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
1094                 features->not_context_indexed_files++;
1095         if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE)
1096                 features->sparse_files++;
1097         if (inode_has_named_data_stream(inode))
1098                 features->named_data_streams++;
1099         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1100                 features->reparse_points++;
1101                 if (inode_is_symlink(inode))
1102                         features->symlink_reparse_points++;
1103                 else
1104                         features->other_reparse_points++;
1105         }
1106         if (inode_has_security_descriptor(inode))
1107                 features->security_descriptors++;
1108         if (inode_has_unix_data(inode))
1109                 features->unix_data++;
1110 }
1111
1112 /* Tally features necessary to extract a dentry and the corresponding inode.  */
1113 static void
1114 dentry_tally_features(struct wim_dentry *dentry, struct wim_features *features)
1115 {
1116         struct wim_inode *inode = dentry->d_inode;
1117
1118         if (dentry_has_short_name(dentry))
1119                 features->short_names++;
1120
1121         if (inode->i_visited) {
1122                 features->hard_links++;
1123         } else {
1124                 inode_tally_features(inode, features);
1125                 inode->i_visited = 1;
1126         }
1127 }
1128
1129 /* Tally the features necessary to extract the specified dentries.  */
1130 static void
1131 dentry_list_get_features(struct list_head *dentry_list,
1132                          struct wim_features *features)
1133 {
1134         struct wim_dentry *dentry;
1135
1136         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1137                 dentry_tally_features(dentry, features);
1138
1139         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1140                 dentry->d_inode->i_visited = 0;
1141 }
1142
1143 static int
1144 do_feature_check(const struct wim_features *required_features,
1145                  const struct wim_features *supported_features,
1146                  int extract_flags)
1147 {
1148         /* Encrypted files.  */
1149         if (required_features->encrypted_files &&
1150             !supported_features->encrypted_files)
1151                 WARNING("Ignoring EFS-encrypted data of %lu files",
1152                         required_features->encrypted_files);
1153
1154         /* Named data streams.  */
1155         if (required_features->named_data_streams &&
1156             !supported_features->named_data_streams)
1157                 WARNING("Ignoring named data streams of %lu files",
1158                         required_features->named_data_streams);
1159
1160         /* File attributes.  */
1161         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
1162                 /* Note: Don't bother the user about FILE_ATTRIBUTE_ARCHIVE.
1163                  * We're an archive program, so theoretically we can do what we
1164                  * want with it.  */
1165
1166                 if (required_features->hidden_files &&
1167                     !supported_features->hidden_files)
1168                         WARNING("Ignoring FILE_ATTRIBUTE_HIDDEN of %lu files",
1169                                 required_features->hidden_files);
1170
1171                 if (required_features->system_files &&
1172                     !supported_features->system_files)
1173                         WARNING("Ignoring FILE_ATTRIBUTE_SYSTEM of %lu files",
1174                                 required_features->system_files);
1175
1176                 if (required_features->compressed_files &&
1177                     !supported_features->compressed_files)
1178                         WARNING("Ignoring FILE_ATTRIBUTE_COMPRESSED of %lu files",
1179                                 required_features->compressed_files);
1180
1181                 if (required_features->not_context_indexed_files &&
1182                     !supported_features->not_context_indexed_files)
1183                         WARNING("Ignoring FILE_ATTRIBUTE_NOT_CONTENT_INDEXED of %lu files",
1184                                 required_features->not_context_indexed_files);
1185
1186                 if (required_features->sparse_files &&
1187                     !supported_features->sparse_files)
1188                         WARNING("Ignoring FILE_ATTRIBUTE_SPARSE_FILE of %lu files",
1189                                 required_features->sparse_files);
1190
1191                 if (required_features->encrypted_directories &&
1192                     !supported_features->encrypted_directories)
1193                         WARNING("Ignoring FILE_ATTRIBUTE_ENCRYPTED of %lu directories",
1194                                 required_features->encrypted_directories);
1195         }
1196
1197         /* Hard links.  */
1198         if (required_features->hard_links && !supported_features->hard_links)
1199                 WARNING("Extracting %lu hard links as independent files",
1200                         required_features->hard_links);
1201
1202         /* Symbolic links and reparse points.  */
1203         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS) &&
1204             required_features->symlink_reparse_points &&
1205             !supported_features->symlink_reparse_points &&
1206             !supported_features->reparse_points)
1207         {
1208                 ERROR("Extraction backend does not support symbolic links!");
1209                 return WIMLIB_ERR_UNSUPPORTED;
1210         }
1211         if (required_features->reparse_points &&
1212             !supported_features->reparse_points)
1213         {
1214                 if (supported_features->symlink_reparse_points) {
1215                         if (required_features->other_reparse_points) {
1216                                 WARNING("Ignoring reparse data of %lu non-symlink/junction files",
1217                                         required_features->other_reparse_points);
1218                         }
1219                 } else {
1220                         WARNING("Ignoring reparse data of %lu files",
1221                                 required_features->reparse_points);
1222                 }
1223         }
1224
1225         /* Security descriptors.  */
1226         if (((extract_flags & (WIMLIB_EXTRACT_FLAG_STRICT_ACLS |
1227                                WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1228              == WIMLIB_EXTRACT_FLAG_STRICT_ACLS) &&
1229             required_features->security_descriptors &&
1230             !supported_features->security_descriptors)
1231         {
1232                 ERROR("Extraction backend does not support security descriptors!");
1233                 return WIMLIB_ERR_UNSUPPORTED;
1234         }
1235         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS) &&
1236             required_features->security_descriptors &&
1237             !supported_features->security_descriptors)
1238                 WARNING("Ignoring Windows NT security descriptors of %lu files",
1239                         required_features->security_descriptors);
1240
1241         /* UNIX data.  */
1242         if ((extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
1243             required_features->unix_data && !supported_features->unix_data)
1244         {
1245                 ERROR("Extraction backend does not support UNIX data!");
1246                 return WIMLIB_ERR_UNSUPPORTED;
1247         }
1248
1249         if (required_features->unix_data &&
1250             !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1251         {
1252                 WARNING("Ignoring UNIX metadata of %lu files",
1253                         required_features->unix_data);
1254         }
1255
1256         /* DOS Names.  */
1257         if (required_features->short_names &&
1258             !supported_features->short_names)
1259         {
1260                 if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES) {
1261                         ERROR("Extraction backend does not support DOS names!");
1262                         return WIMLIB_ERR_UNSUPPORTED;
1263                 }
1264                 WARNING("Ignoring DOS names of %lu files",
1265                         required_features->short_names);
1266         }
1267
1268         /* Timestamps.  */
1269         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) &&
1270             !supported_features->timestamps)
1271         {
1272                 ERROR("Extraction backend does not support timestamps!");
1273                 return WIMLIB_ERR_UNSUPPORTED;
1274         }
1275
1276         return 0;
1277 }
1278
1279 static const struct apply_operations *
1280 select_apply_operations(int extract_flags)
1281 {
1282 #ifdef WITH_NTFS_3G
1283         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
1284                 return &ntfs_3g_apply_ops;
1285 #endif
1286 #ifdef __WIN32__
1287         return &win32_apply_ops;
1288 #else
1289         return &unix_apply_ops;
1290 #endif
1291 }
1292
1293 static int
1294 extract_trees(WIMStruct *wim, struct wim_dentry **trees, size_t num_trees,
1295               const tchar *target, int extract_flags)
1296 {
1297         const struct apply_operations *ops;
1298         struct apply_ctx *ctx;
1299         int ret;
1300         LIST_HEAD(dentry_list);
1301
1302         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
1303                 ret = extract_dentries_to_stdout(trees, num_trees,
1304                                                  wim->blob_table);
1305                 goto out;
1306         }
1307
1308         num_trees = remove_duplicate_trees(trees, num_trees);
1309         num_trees = remove_contained_trees(trees, num_trees);
1310
1311         ops = select_apply_operations(extract_flags);
1312
1313         if (num_trees > 1 && ops->single_tree_only) {
1314                 ERROR("Extracting multiple directory trees "
1315                       "at once is not supported in %s extraction mode!",
1316                       ops->name);
1317                 ret = WIMLIB_ERR_UNSUPPORTED;
1318                 goto out;
1319         }
1320
1321         ctx = CALLOC(1, ops->context_size);
1322         if (!ctx) {
1323                 ret = WIMLIB_ERR_NOMEM;
1324                 goto out;
1325         }
1326
1327         ctx->wim = wim;
1328         ctx->target = target;
1329         ctx->target_nchars = tstrlen(target);
1330         ctx->extract_flags = extract_flags;
1331         if (ctx->wim->progfunc) {
1332                 ctx->progfunc = ctx->wim->progfunc;
1333                 ctx->progctx = ctx->wim->progctx;
1334                 ctx->progress.extract.image = wim->current_image;
1335                 ctx->progress.extract.extract_flags = (extract_flags &
1336                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
1337                 ctx->progress.extract.wimfile_name = wim->filename;
1338                 ctx->progress.extract.image_name = wimlib_get_image_name(wim,
1339                                                                          wim->current_image);
1340                 ctx->progress.extract.target = target;
1341         }
1342         INIT_LIST_HEAD(&ctx->blob_list);
1343         filedes_invalidate(&ctx->tmpfile_fd);
1344         ctx->apply_ops = ops;
1345
1346         ret = (*ops->get_supported_features)(target, &ctx->supported_features);
1347         if (ret)
1348                 goto out_cleanup;
1349
1350         build_dentry_list(&dentry_list, trees, num_trees,
1351                           !(extract_flags &
1352                             WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE));
1353
1354         dentry_list_get_features(&dentry_list, &ctx->required_features);
1355
1356         ret = do_feature_check(&ctx->required_features, &ctx->supported_features,
1357                                ctx->extract_flags);
1358         if (ret)
1359                 goto out_cleanup;
1360
1361         ret = dentry_list_calculate_extraction_names(&dentry_list, ctx);
1362         if (ret)
1363                 goto out_cleanup;
1364
1365         if (unlikely(list_empty(&dentry_list))) {
1366                 WARNING("There is nothing to extract!");
1367                 goto out_cleanup;
1368         }
1369
1370         ret = dentry_list_resolve_streams(&dentry_list, ctx);
1371         if (ret)
1372                 goto out_cleanup;
1373
1374         dentry_list_build_inode_alias_lists(&dentry_list);
1375
1376         ret = dentry_list_ref_streams(&dentry_list, ctx);
1377         if (ret)
1378                 goto out_cleanup;
1379
1380         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
1381                 /* When extracting from a pipe, the number of bytes of data to
1382                  * extract can't be determined in the normal way (examining the
1383                  * blob table), since at this point all we have is a set of
1384                  * SHA-1 message digests of blobs that need to be extracted.
1385                  * However, we can get a reasonably accurate estimate by taking
1386                  * <TOTALBYTES> from the corresponding <IMAGE> in the WIM XML
1387                  * data.  This does assume that a full image is being extracted,
1388                  * but currently there is no API for doing otherwise.  (Also,
1389                  * subtract <HARDLINKBYTES> from this if hard links are
1390                  * supported by the extraction mode.)  */
1391                 ctx->progress.extract.total_bytes =
1392                         wim_info_get_image_total_bytes(wim->wim_info,
1393                                                        wim->current_image);
1394                 if (ctx->supported_features.hard_links) {
1395                         ctx->progress.extract.total_bytes -=
1396                                 wim_info_get_image_hard_link_bytes(wim->wim_info,
1397                                                                    wim->current_image);
1398                 }
1399         }
1400
1401         ret = extract_progress(ctx,
1402                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1403                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN :
1404                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN));
1405         if (ret)
1406                 goto out_cleanup;
1407
1408         ret = (*ops->extract)(&dentry_list, ctx);
1409         if (ret)
1410                 goto out_cleanup;
1411
1412         if (ctx->progress.extract.completed_bytes <
1413             ctx->progress.extract.total_bytes)
1414         {
1415                 ctx->progress.extract.completed_bytes =
1416                         ctx->progress.extract.total_bytes;
1417                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
1418                 if (ret)
1419                         goto out_cleanup;
1420         }
1421
1422         ret = extract_progress(ctx,
1423                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1424                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END :
1425                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END));
1426 out_cleanup:
1427         destroy_blob_list(&ctx->blob_list);
1428         destroy_dentry_list(&dentry_list);
1429         FREE(ctx);
1430 out:
1431         return ret;
1432 }
1433
1434 static int
1435 mkdir_if_needed(const tchar *target)
1436 {
1437         if (!tmkdir(target, 0755))
1438                 return 0;
1439
1440         if (errno == EEXIST)
1441                 return 0;
1442
1443 #ifdef __WIN32__
1444         /* _wmkdir() fails with EACCES if called on a drive root directory.  */
1445         if (errno == EACCES)
1446                 return 0;
1447 #endif
1448
1449         ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
1450         return WIMLIB_ERR_MKDIR;
1451 }
1452
1453 /* Make sure the extraction flags make sense, and update them if needed.  */
1454 static int
1455 check_extract_flags(const WIMStruct *wim, int *extract_flags_p)
1456 {
1457         int extract_flags = *extract_flags_p;
1458
1459         /* Check for invalid flag combinations  */
1460
1461         if ((extract_flags &
1462              (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1463               WIMLIB_EXTRACT_FLAG_STRICT_ACLS)) == (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1464                                                     WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
1465                 return WIMLIB_ERR_INVALID_PARAM;
1466
1467         if ((extract_flags &
1468              (WIMLIB_EXTRACT_FLAG_RPFIX |
1469               WIMLIB_EXTRACT_FLAG_NORPFIX)) == (WIMLIB_EXTRACT_FLAG_RPFIX |
1470                                                 WIMLIB_EXTRACT_FLAG_NORPFIX))
1471                 return WIMLIB_ERR_INVALID_PARAM;
1472
1473 #ifndef WITH_NTFS_3G
1474         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1475                 ERROR("wimlib was compiled without support for NTFS-3g, so\n"
1476                       "        it cannot apply a WIM image directly to an NTFS volume.");
1477                 return WIMLIB_ERR_UNSUPPORTED;
1478         }
1479 #endif
1480
1481         if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
1482 #ifdef __WIN32__
1483                 if (!wim->filename)
1484                         return WIMLIB_ERR_NO_FILENAME;
1485 #else
1486                 ERROR("WIMBoot extraction is only supported on Windows!");
1487                 return WIMLIB_ERR_UNSUPPORTED;
1488 #endif
1489         }
1490
1491
1492         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
1493                               WIMLIB_EXTRACT_FLAG_NORPFIX |
1494                               WIMLIB_EXTRACT_FLAG_IMAGEMODE)) ==
1495                                         WIMLIB_EXTRACT_FLAG_IMAGEMODE)
1496         {
1497                 /* For full-image extraction, do reparse point fixups by default
1498                  * if the WIM header says they are enabled.  */
1499                 if (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
1500                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
1501         }
1502
1503         *extract_flags_p = extract_flags;
1504         return 0;
1505 }
1506
1507 struct append_dentry_ctx {
1508         struct wim_dentry **dentries;
1509         size_t num_dentries;
1510         size_t num_alloc_dentries;
1511 };
1512
1513 static int
1514 append_dentry_cb(struct wim_dentry *dentry, void *_ctx)
1515 {
1516         struct append_dentry_ctx *ctx = _ctx;
1517
1518         if (ctx->num_dentries == ctx->num_alloc_dentries) {
1519                 struct wim_dentry **new_dentries;
1520                 size_t new_length;
1521
1522                 new_length = max(ctx->num_alloc_dentries + 8,
1523                                  ctx->num_alloc_dentries * 3 / 2);
1524                 new_dentries = REALLOC(ctx->dentries,
1525                                        new_length * sizeof(ctx->dentries[0]));
1526                 if (new_dentries == NULL)
1527                         return WIMLIB_ERR_NOMEM;
1528                 ctx->dentries = new_dentries;
1529                 ctx->num_alloc_dentries = new_length;
1530         }
1531         ctx->dentries[ctx->num_dentries++] = dentry;
1532         return 0;
1533 }
1534
1535 /* Append dentries matched by a path which can contain wildcard characters.  */
1536 static int
1537 append_matched_dentries(WIMStruct *wim, const tchar *orig_pattern,
1538                         int extract_flags, struct append_dentry_ctx *ctx)
1539 {
1540         const size_t count_before = ctx->num_dentries;
1541         tchar *pattern;
1542         int ret;
1543
1544         pattern = canonicalize_wim_path(orig_pattern);
1545         if (!pattern)
1546                 return WIMLIB_ERR_NOMEM;
1547         ret = expand_path_pattern(wim_get_current_root_dentry(wim), pattern,
1548                                   append_dentry_cb, ctx);
1549         FREE(pattern);
1550         if (ret || ctx->num_dentries > count_before)
1551                 return ret;
1552         if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_GLOB) {
1553                 ERROR("No matches for path pattern \"%"TS"\"", orig_pattern);
1554                 return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1555         }
1556         WARNING("No matches for path pattern \"%"TS"\"", orig_pattern);
1557         return 0;
1558 }
1559
1560 static int
1561 do_wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1562                         const tchar * const *paths, size_t num_paths,
1563                         int extract_flags)
1564 {
1565         int ret;
1566         struct wim_dentry **trees;
1567         size_t num_trees;
1568
1569         if (wim == NULL || target == NULL || target[0] == T('\0') ||
1570             (num_paths != 0 && paths == NULL))
1571                 return WIMLIB_ERR_INVALID_PARAM;
1572
1573         ret = check_extract_flags(wim, &extract_flags);
1574         if (ret)
1575                 return ret;
1576
1577         ret = select_wim_image(wim, image);
1578         if (ret)
1579                 return ret;
1580
1581         ret = wim_checksum_unhashed_blobs(wim);
1582         if (ret)
1583                 return ret;
1584
1585         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_NTFS |
1586                               WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE)) ==
1587             (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE))
1588         {
1589                 ret = mkdir_if_needed(target);
1590                 if (ret)
1591                         return ret;
1592         }
1593
1594         if (extract_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {
1595
1596                 struct append_dentry_ctx append_dentry_ctx = {
1597                         .dentries = NULL,
1598                         .num_dentries = 0,
1599                         .num_alloc_dentries = 0,
1600                 };
1601
1602                 for (size_t i = 0; i < num_paths; i++) {
1603                         ret = append_matched_dentries(wim, paths[i],
1604                                                       extract_flags,
1605                                                       &append_dentry_ctx);
1606                         if (ret) {
1607                                 trees = append_dentry_ctx.dentries;
1608                                 goto out_free_trees;
1609                         }
1610                 }
1611                 trees = append_dentry_ctx.dentries;
1612                 num_trees = append_dentry_ctx.num_dentries;
1613         } else {
1614                 trees = MALLOC(num_paths * sizeof(trees[0]));
1615                 if (trees == NULL)
1616                         return WIMLIB_ERR_NOMEM;
1617
1618                 for (size_t i = 0; i < num_paths; i++) {
1619
1620                         tchar *path = canonicalize_wim_path(paths[i]);
1621                         if (path == NULL) {
1622                                 ret = WIMLIB_ERR_NOMEM;
1623                                 goto out_free_trees;
1624                         }
1625
1626                         trees[i] = get_dentry(wim, path,
1627                                               WIMLIB_CASE_PLATFORM_DEFAULT);
1628                         FREE(path);
1629                         if (trees[i] == NULL) {
1630                                   ERROR("Path \"%"TS"\" does not exist "
1631                                         "in WIM image %d",
1632                                         paths[i], wim->current_image);
1633                                   ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1634                                   goto out_free_trees;
1635                         }
1636                 }
1637                 num_trees = num_paths;
1638         }
1639
1640         if (num_trees == 0) {
1641                 ret = 0;
1642                 goto out_free_trees;
1643         }
1644
1645         ret = extract_trees(wim, trees, num_trees, target, extract_flags);
1646 out_free_trees:
1647         FREE(trees);
1648         return ret;
1649 }
1650
1651 static int
1652 extract_single_image(WIMStruct *wim, int image,
1653                      const tchar *target, int extract_flags)
1654 {
1655         const tchar *path = WIMLIB_WIM_ROOT_PATH;
1656         extract_flags |= WIMLIB_EXTRACT_FLAG_IMAGEMODE;
1657         return do_wimlib_extract_paths(wim, image, target, &path, 1, extract_flags);
1658 }
1659
1660 static const tchar * const filename_forbidden_chars =
1661 T(
1662 #ifdef __WIN32__
1663 "<>:\"/\\|?*"
1664 #else
1665 "/"
1666 #endif
1667 );
1668
1669 /* This function checks if it is okay to use a WIM image's name as a directory
1670  * name.  */
1671 static bool
1672 image_name_ok_as_dir(const tchar *image_name)
1673 {
1674         return image_name && *image_name &&
1675                 !tstrpbrk(image_name, filename_forbidden_chars) &&
1676                 tstrcmp(image_name, T(".")) &&
1677                 tstrcmp(image_name, T(".."));
1678 }
1679
1680 /* Extracts all images from the WIM to the directory @target, with the images
1681  * placed in subdirectories named by their image names. */
1682 static int
1683 extract_all_images(WIMStruct *wim, const tchar *target, int extract_flags)
1684 {
1685         size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
1686         size_t output_path_len = tstrlen(target);
1687         tchar buf[output_path_len + 1 + image_name_max_len + 1];
1688         int ret;
1689         int image;
1690         const tchar *image_name;
1691
1692         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1693                 ERROR("Cannot extract multiple images in NTFS extraction mode.");
1694                 return WIMLIB_ERR_INVALID_PARAM;
1695         }
1696
1697         ret = mkdir_if_needed(target);
1698         if (ret)
1699                 return ret;
1700         tmemcpy(buf, target, output_path_len);
1701         buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
1702         for (image = 1; image <= wim->hdr.image_count; image++) {
1703                 image_name = wimlib_get_image_name(wim, image);
1704                 if (image_name_ok_as_dir(image_name)) {
1705                         tstrcpy(buf + output_path_len + 1, image_name);
1706                 } else {
1707                         /* Image name is empty or contains forbidden characters.
1708                          * Use image number instead. */
1709                         tsprintf(buf + output_path_len + 1, T("%d"), image);
1710                 }
1711                 ret = extract_single_image(wim, image, buf, extract_flags);
1712                 if (ret)
1713                         return ret;
1714         }
1715         return 0;
1716 }
1717
1718 static int
1719 do_wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1720                         int extract_flags)
1721 {
1722         if (extract_flags & (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
1723                              WIMLIB_EXTRACT_FLAG_TO_STDOUT |
1724                              WIMLIB_EXTRACT_FLAG_GLOB_PATHS))
1725                 return WIMLIB_ERR_INVALID_PARAM;
1726
1727         if (image == WIMLIB_ALL_IMAGES)
1728                 return extract_all_images(wim, target, extract_flags);
1729         else
1730                 return extract_single_image(wim, image, target, extract_flags);
1731 }
1732
1733
1734 /****************************************************************************
1735  *                          Extraction API                                  *
1736  ****************************************************************************/
1737
1738 WIMLIBAPI int
1739 wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1740                      const tchar * const *paths, size_t num_paths,
1741                      int extract_flags)
1742 {
1743         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1744                 return WIMLIB_ERR_INVALID_PARAM;
1745
1746         return do_wimlib_extract_paths(wim, image, target, paths, num_paths,
1747                                        extract_flags);
1748 }
1749
1750 WIMLIBAPI int
1751 wimlib_extract_pathlist(WIMStruct *wim, int image, const tchar *target,
1752                         const tchar *path_list_file, int extract_flags)
1753 {
1754         int ret;
1755         tchar **paths;
1756         size_t num_paths;
1757         void *mem;
1758
1759         ret = read_path_list_file(path_list_file, &paths, &num_paths, &mem);
1760         if (ret) {
1761                 ERROR("Failed to read path list file \"%"TS"\"",
1762                       path_list_file);
1763                 return ret;
1764         }
1765
1766         ret = wimlib_extract_paths(wim, image, target,
1767                                    (const tchar * const *)paths, num_paths,
1768                                    extract_flags);
1769         FREE(paths);
1770         FREE(mem);
1771         return ret;
1772 }
1773
1774 WIMLIBAPI int
1775 wimlib_extract_image_from_pipe_with_progress(int pipe_fd,
1776                                              const tchar *image_num_or_name,
1777                                              const tchar *target,
1778                                              int extract_flags,
1779                                              wimlib_progress_func_t progfunc,
1780                                              void *progctx)
1781 {
1782         int ret;
1783         WIMStruct *pwm;
1784         struct filedes *in_fd;
1785         int image;
1786         unsigned i;
1787
1788         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1789                 return WIMLIB_ERR_INVALID_PARAM;
1790
1791         /* Read the WIM header from the pipe and get a WIMStruct to represent
1792          * the pipable WIM.  Caveats:  Unlike getting a WIMStruct with
1793          * wimlib_open_wim(), getting a WIMStruct in this way will result in an
1794          * empty blob table, no XML data read, and no filename set.  */
1795         ret = open_wim_as_WIMStruct(&pipe_fd, WIMLIB_OPEN_FLAG_FROM_PIPE, &pwm,
1796                                     progfunc, progctx);
1797         if (ret)
1798                 return ret;
1799
1800         /* Sanity check to make sure this is a pipable WIM.  */
1801         if (pwm->hdr.magic != PWM_MAGIC) {
1802                 ERROR("The WIM being read from file descriptor %d "
1803                       "is not pipable!", pipe_fd);
1804                 ret = WIMLIB_ERR_NOT_PIPABLE;
1805                 goto out_wimlib_free;
1806         }
1807
1808         /* Sanity check to make sure the first part of a pipable split WIM is
1809          * sent over the pipe first.  */
1810         if (pwm->hdr.part_number != 1) {
1811                 ERROR("The first part of the split WIM must be "
1812                       "sent over the pipe first.");
1813                 ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1814                 goto out_wimlib_free;
1815         }
1816
1817         in_fd = &pwm->in_fd;
1818         wimlib_assert(in_fd->offset == WIM_HEADER_DISK_SIZE);
1819
1820         /* As mentioned, the WIMStruct we created from the pipe does not have
1821          * XML data yet.  Fix this by reading the extra copy of the XML data
1822          * that directly follows the header in pipable WIMs.  (Note: see
1823          * write_pipable_wim() for more details about the format of pipable
1824          * WIMs.)  */
1825         {
1826                 u8 hash[SHA1_HASH_SIZE];
1827
1828                 ret = read_pwm_blob_header(pwm, hash,
1829                                            &pwm->hdr.xml_data_reshdr, NULL);
1830                 if (ret)
1831                         goto out_wimlib_free;
1832
1833                 if (!(pwm->hdr.xml_data_reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1834                         ERROR("Expected XML data, but found non-metadata resource.");
1835                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1836                         goto out_wimlib_free;
1837                 }
1838
1839                 ret = read_wim_xml_data(pwm);
1840                 if (ret)
1841                         goto out_wimlib_free;
1842
1843                 if (wim_info_get_num_images(pwm->wim_info) != pwm->hdr.image_count) {
1844                         ERROR("Image count in XML data is not the same as in WIM header.");
1845                         ret = WIMLIB_ERR_IMAGE_COUNT;
1846                         goto out_wimlib_free;
1847                 }
1848         }
1849
1850         /* Get image index (this may use the XML data that was just read to
1851          * resolve an image name).  */
1852         if (image_num_or_name) {
1853                 image = wimlib_resolve_image(pwm, image_num_or_name);
1854                 if (image == WIMLIB_NO_IMAGE) {
1855                         ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
1856                               image_num_or_name);
1857                         ret = WIMLIB_ERR_INVALID_IMAGE;
1858                         goto out_wimlib_free;
1859                 } else if (image == WIMLIB_ALL_IMAGES) {
1860                         ERROR("Applying all images from a pipe is not supported!");
1861                         ret = WIMLIB_ERR_INVALID_IMAGE;
1862                         goto out_wimlib_free;
1863                 }
1864         } else {
1865                 if (pwm->hdr.image_count != 1) {
1866                         ERROR("No image was specified, but the pipable WIM "
1867                               "did not contain exactly 1 image");
1868                         ret = WIMLIB_ERR_INVALID_IMAGE;
1869                         goto out_wimlib_free;
1870                 }
1871                 image = 1;
1872         }
1873
1874         /* Load the needed metadata resource.  */
1875         for (i = 1; i <= pwm->hdr.image_count; i++) {
1876                 struct wim_image_metadata *imd;
1877                 struct wim_reshdr reshdr;
1878                 struct wim_resource_descriptor *metadata_rdesc;
1879
1880                 imd = pwm->image_metadata[i - 1];
1881
1882                 ret = WIMLIB_ERR_NOMEM;
1883                 imd->metadata_blob = new_blob_descriptor();
1884                 if (!imd->metadata_blob)
1885                         goto out_wimlib_free;
1886
1887                 imd->metadata_blob->is_metadata = 1;
1888
1889                 ret = read_pwm_blob_header(pwm, imd->metadata_blob->hash,
1890                                            &reshdr, NULL);
1891                 if (ret)
1892                         goto out_wimlib_free;
1893
1894                 if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
1895                         ERROR("Expected metadata resource, but found "
1896                               "non-metadata resource");
1897                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1898                         goto out_wimlib_free;
1899                 }
1900
1901                 ret = WIMLIB_ERR_NOMEM;
1902                 metadata_rdesc = MALLOC(sizeof(struct wim_resource_descriptor));
1903                 if (!metadata_rdesc)
1904                         goto out_wimlib_free;
1905                 wim_reshdr_to_desc_and_blob(&reshdr, pwm, metadata_rdesc,
1906                                             imd->metadata_blob);
1907
1908                 if (i == image) {
1909                         /* Metadata resource is for the image being extracted.
1910                          * Parse it and save the metadata in memory.  */
1911                         ret = read_metadata_resource(imd);
1912                         if (ret)
1913                                 goto out_wimlib_free;
1914                         imd->modified = 1;
1915                 } else {
1916                         /* Metadata resource is not for the image being
1917                          * extracted.  Skip over it.  */
1918                         ret = skip_wim_resource(metadata_rdesc);
1919                         if (ret)
1920                                 goto out_wimlib_free;
1921                 }
1922         }
1923         /* Extract the image.  */
1924         extract_flags |= WIMLIB_EXTRACT_FLAG_FROM_PIPE;
1925         ret = do_wimlib_extract_image(pwm, image, target, extract_flags);
1926         /* Clean up and return.  */
1927 out_wimlib_free:
1928         wimlib_free(pwm);
1929         return ret;
1930 }
1931
1932
1933 WIMLIBAPI int
1934 wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
1935                                const tchar *target, int extract_flags)
1936 {
1937         return wimlib_extract_image_from_pipe_with_progress(pipe_fd,
1938                                                             image_num_or_name,
1939                                                             target,
1940                                                             extract_flags,
1941                                                             NULL,
1942                                                             NULL);
1943 }
1944
1945 WIMLIBAPI int
1946 wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1947                      int extract_flags)
1948 {
1949         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1950                 return WIMLIB_ERR_INVALID_PARAM;
1951         return do_wimlib_extract_image(wim, image, target, extract_flags);
1952 }