4 * Support for extracting WIM files.
6 * This code does NOT contain any filesystem-specific features. In particular,
7 * security information (i.e. file permissions) and alternate data streams are
8 * ignored, except possibly to read an alternate data stream that contains
13 * Copyright (C) 2010 Carl Thijssen
14 * Copyright (C) 2012 Eric Biggers
16 * This file is part of wimlib, a library for working with WIM files.
18 * wimlib is free software; you can redistribute it and/or modify it under the
19 * terms of the GNU General Public License as published by the Free
20 * Software Foundation; either version 3 of the License, or (at your option)
23 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
24 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
25 * A PARTICULAR PURPOSE. See the GNU General Public License for more
28 * You should have received a copy of the GNU General Public License
29 * along with wimlib; if not, see http://www.gnu.org/licenses/.
43 #include "lookup_table.h"
44 #include "timestamp.h"
45 #include "wimlib_internal.h"
49 #define WIMLIB_EXTRACT_FLAG_MULTI_IMAGE 0x80000000
51 static int extract_regular_file_linked(const struct dentry *dentry,
52 const char *output_dir,
53 const char *output_path,
55 struct lookup_table_entry *lte)
57 /* This mode overrides the normal hard-link extraction and
58 * instead either symlinks or hardlinks *all* identical files in
59 * the WIM, even if they are in a different image (in the case
60 * of a multi-image extraction) */
61 wimlib_assert(lte->extracted_file);
63 if (extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK) {
64 if (link(lte->extracted_file, output_path) != 0) {
65 ERROR_WITH_ERRNO("Failed to hard link "
67 output_path, lte->extracted_file);
68 return WIMLIB_ERR_LINK;
71 int num_path_components;
72 int num_output_dir_path_components;
73 size_t extracted_file_len;
78 wimlib_assert(extract_flags & WIMLIB_EXTRACT_FLAG_SYMLINK);
81 get_num_path_components(dentry->full_path_utf8) - 1;
82 num_output_dir_path_components =
83 get_num_path_components(output_dir);
85 if (extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
86 num_path_components++;
87 num_output_dir_path_components--;
89 extracted_file_len = strlen(lte->extracted_file);
91 char buf[extracted_file_len + 3 * num_path_components + 1];
94 for (i = 0; i < num_path_components; i++) {
99 p2 = lte->extracted_file;
102 while (num_output_dir_path_components--)
103 p2 = path_next_part(p2, NULL);
105 if (symlink(buf, output_path) != 0) {
106 ERROR_WITH_ERRNO("Failed to symlink `%s' to "
108 buf, lte->extracted_file);
109 return WIMLIB_ERR_LINK;
116 static int extract_regular_file_unlinked(WIMStruct *w,
117 struct dentry *dentry,
118 const char *output_path,
120 struct lookup_table_entry *lte)
122 /* Normal mode of extraction. Regular files and hard links are
123 * extracted in the way that they appear in the WIM. */
127 const struct list_head *head = &dentry->link_group_list;
129 if (head->next != head &&
130 !(extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE))
132 /* This dentry is one of a hard link set of at least 2 dentries.
133 * If one of the other dentries has already been extracted, make
134 * a hard link to the file corresponding to this
135 * already-extracted directory. Otherwise, extract the
136 * file, and set the dentry->extracted_file field so that other
137 * dentries in the hard link group can link to it. */
138 struct dentry *other;
139 list_for_each_entry(other, head, link_group_list) {
140 if (other->extracted_file) {
141 DEBUG("Extracting hard link `%s' => `%s'",
142 output_path, other->extracted_file);
143 if (link(other->extracted_file, output_path) != 0) {
144 ERROR_WITH_ERRNO("Failed to hard link "
147 other->extracted_file);
148 return WIMLIB_ERR_LINK;
153 FREE(dentry->extracted_file);
154 dentry->extracted_file = STRDUP(output_path);
155 if (!dentry->extracted_file) {
156 ERROR("Failed to allocate memory for filename");
157 return WIMLIB_ERR_NOMEM;
161 /* Extract the contents of the file to @output_path. */
163 out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
165 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
167 return WIMLIB_ERR_OPEN;
171 /* Empty file with no lookup table entry */
172 DEBUG("Empty file `%s'.", output_path);
177 ret = extract_full_wim_resource_to_fd(lte, out_fd);
179 ERROR("Failed to extract resource to `%s'", output_path);
184 if (close(out_fd) != 0) {
185 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
186 ret = WIMLIB_ERR_WRITE;
192 * Extracts a regular file from the WIM archive.
194 static int extract_regular_file(WIMStruct *w,
195 struct dentry *dentry,
196 const char *output_dir,
197 const char *output_path,
200 struct lookup_table_entry *lte;
202 lte = dentry_unnamed_lte(dentry, w->lookup_table);
204 if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
205 WIMLIB_EXTRACT_FLAG_HARDLINK)) && lte) {
206 if (++lte->out_refcnt != 1)
207 return extract_regular_file_linked(dentry, output_dir,
210 lte->extracted_file = STRDUP(output_path);
211 if (!lte->extracted_file)
212 return WIMLIB_ERR_NOMEM;
215 return extract_regular_file_unlinked(w, dentry, output_path,
220 static int extract_symlink(const struct dentry *dentry, const char *output_path,
224 ssize_t ret = dentry_readlink(dentry, target, sizeof(target), w);
226 ERROR("Could not read the symbolic link from dentry `%s'",
227 dentry->full_path_utf8);
228 return WIMLIB_ERR_INVALID_DENTRY;
230 ret = symlink(target, output_path);
232 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
233 output_path, target);
234 return WIMLIB_ERR_LINK;
240 * Extracts a directory from the WIM archive.
242 * @dentry: The directory entry for the directory.
243 * @output_path: The path to which the directory is to be extracted to.
244 * @return: True on success, false on failure.
246 static int extract_directory(const char *output_path, bool is_root)
250 ret = stat(output_path, &stbuf);
252 if (S_ISDIR(stbuf.st_mode)) {
254 WARNING("`%s' already exists", output_path);
257 ERROR("`%s' is not a directory", output_path);
258 return WIMLIB_ERR_MKDIR;
261 if (errno != ENOENT) {
262 ERROR_WITH_ERRNO("Failed to stat `%s'", output_path);
263 return WIMLIB_ERR_STAT;
266 /* Compute the output path directory to the directory. */
267 if (mkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP |
268 S_IROTH | S_IXOTH) != 0) {
269 ERROR_WITH_ERRNO("Cannot create directory `%s'",
271 return WIMLIB_ERR_MKDIR;
276 struct extract_args {
279 const char *output_dir;
283 * Extracts a file, directory, or symbolic link from the WIM archive. For use
284 * in for_dentry_in_tree().
286 static int extract_dentry(struct dentry *dentry, void *arg)
288 struct extract_args *args = arg;
289 WIMStruct *w = args->w;
290 int extract_flags = args->extract_flags;
291 size_t len = strlen(args->output_dir);
292 char output_path[len + dentry->full_path_utf8_len + 1];
294 if (extract_flags & WIMLIB_EXTRACT_FLAG_VERBOSE) {
295 wimlib_assert(dentry->full_path_utf8);
296 puts(dentry->full_path_utf8);
299 memcpy(output_path, args->output_dir, len);
300 memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
301 output_path[len + dentry->full_path_utf8_len] = '\0';
303 if (dentry_is_symlink(dentry))
304 return extract_symlink(dentry, output_path, w);
305 else if (dentry_is_directory(dentry))
306 return extract_directory(output_path, dentry_is_root(dentry));
308 return extract_regular_file(w, dentry, args->output_dir,
309 output_path, extract_flags);
312 /* Apply timestamp to extracted file */
313 static int apply_dentry_timestamps(struct dentry *dentry, void *arg)
315 struct extract_args *args = arg;
316 size_t len = strlen(args->output_dir);
317 char output_path[len + dentry->full_path_utf8_len + 1];
319 memcpy(output_path, args->output_dir, len);
320 memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
321 output_path[len + dentry->full_path_utf8_len] = '\0';
323 struct timeval tv[2];
324 wim_timestamp_to_timeval(dentry->last_access_time, &tv[0]);
325 wim_timestamp_to_timeval(dentry->last_write_time, &tv[1]);
326 if (lutimes(output_path, tv) != 0) {
327 WARNING("Failed to set timestamp on file `%s': %s",
328 output_path, strerror(errno));
334 static int extract_single_image(WIMStruct *w, int image,
335 const char *output_dir, int extract_flags)
337 DEBUG("Extracting image %d", image);
340 ret = wimlib_select_image(w, image);
344 struct extract_args args = {
346 .extract_flags = extract_flags,
347 .output_dir = output_dir,
350 ret = for_dentry_in_tree(wim_root_dentry(w), extract_dentry, &args);
353 return for_dentry_in_tree_depth(wim_root_dentry(w),
354 apply_dentry_timestamps, &args);
359 /* Extracts all images from the WIM to @output_dir, with the images placed in
360 * subdirectories named by their image names. */
361 static int extract_all_images(WIMStruct *w, const char *output_dir,
364 size_t image_name_max_len = max(xml_get_max_image_name_len(w), 20);
365 size_t output_path_len = strlen(output_dir);
366 char buf[output_path_len + 1 + image_name_max_len + 1];
369 const char *image_name;
371 DEBUG("Attempting to extract all images from `%s' to `%s'",
372 w->filename, output_dir);
374 ret = extract_directory(output_dir, true);
378 memcpy(buf, output_dir, output_path_len);
379 buf[output_path_len] = '/';
380 for (image = 1; image <= w->hdr.image_count; image++) {
382 image_name = wimlib_get_image_name(w, image);
384 strcpy(buf + output_path_len + 1, image_name);
386 /* Image name is empty. Use image number instead */
387 sprintf(buf + output_path_len + 1, "%d", image);
389 ret = extract_single_image(w, image, buf, extract_flags);
397 /* Extracts a single image or all images from a WIM file. */
398 WIMLIBAPI int wimlib_extract_image(WIMStruct *w, int image,
399 const char *output_dir, int flags,
400 WIMStruct **additional_swms,
401 unsigned num_additional_swms)
403 struct lookup_table *joined_tab, *w_tab_save;
406 DEBUG("w->filename = %s, image = %d, output_dir = %s, flags = 0x%x, "
407 "num_additional_swms = %u",
408 w->filename, image, output_dir, flags, num_additional_swms);
410 if (!w || !output_dir)
411 return WIMLIB_ERR_INVALID_PARAM;
413 if ((flags & (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
414 == (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
415 return WIMLIB_ERR_INVALID_PARAM;
417 ret = verify_swm_set(w, additional_swms, num_additional_swms);
421 if (num_additional_swms) {
422 ret = new_joined_lookup_table(w, additional_swms,
423 num_additional_swms, &joined_tab);
426 w_tab_save = w->lookup_table;
427 w->lookup_table = joined_tab;
431 for_lookup_table_entry(w->lookup_table, zero_out_refcnts, NULL);
433 if (image == WIM_ALL_IMAGES) {
434 flags |= WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
435 ret = extract_all_images(w, output_dir, flags);
437 flags &= ~WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
438 ret = extract_single_image(w, image, output_dir, flags);
440 if (num_additional_swms) {
441 free_lookup_table(w->lookup_table);
442 w->lookup_table = w_tab_save;