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 Lesser General Public License as published by the Free
20 * Software Foundation; either version 2.1 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 Lesser General Public License for more
28 * You should have received a copy of the GNU Lesser 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. */
126 const struct resource_entry *res_entry;
128 const struct list_head *head = &dentry->link_group_list;
130 if (head->next != head &&
131 !(extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE))
133 /* This dentry is one of a hard link set of at least 2 dentries.
134 * If one of the other dentries has already been extracted, make
135 * a hard link to the file corresponding to this
136 * already-extracted directory. Otherwise, extract the
137 * file, and set the dentry->extracted_file field so that other
138 * dentries in the hard link group can link to it. */
139 struct dentry *other;
140 list_for_each_entry(other, head, link_group_list) {
141 if (other->extracted_file) {
142 DEBUG("Extracting hard link `%s' => `%s'",
143 output_path, other->extracted_file);
144 if (link(other->extracted_file, output_path) != 0) {
145 ERROR_WITH_ERRNO("Failed to hard link "
148 other->extracted_file);
149 return WIMLIB_ERR_LINK;
154 FREE(dentry->extracted_file);
155 dentry->extracted_file = STRDUP(output_path);
156 if (!dentry->extracted_file) {
157 ERROR("Failed to allocate memory for filename");
158 return WIMLIB_ERR_NOMEM;
162 /* Extract the contents of the file to @output_path. */
164 out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
166 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
168 return WIMLIB_ERR_OPEN;
172 /* Empty file with no lookup table entry */
173 DEBUG("Empty file `%s'.", output_path);
178 ret = extract_full_wim_resource_to_fd(lte, out_fd);
180 ERROR("Failed to extract resource to `%s'", output_path);
185 if (close(out_fd) != 0) {
186 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
187 ret = WIMLIB_ERR_WRITE;
193 * Extracts a regular file from the WIM archive.
195 static int extract_regular_file(WIMStruct *w,
196 struct dentry *dentry,
197 const char *output_dir,
198 const char *output_path,
201 struct lookup_table_entry *lte;
203 lte = dentry_first_lte(dentry, w->lookup_table);
205 if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
206 WIMLIB_EXTRACT_FLAG_HARDLINK)) && lte) {
207 if (++lte->out_refcnt != 1)
208 return extract_regular_file_linked(dentry, output_dir,
211 lte->extracted_file = STRDUP(output_path);
212 if (!lte->extracted_file)
213 return WIMLIB_ERR_NOMEM;
216 return extract_regular_file_unlinked(w, dentry, output_path,
221 static int extract_symlink(const struct dentry *dentry, const char *output_path,
225 ssize_t ret = dentry_readlink(dentry, target, sizeof(target), w);
227 ERROR("Could not read the symbolic link from dentry `%s'",
228 dentry->full_path_utf8);
229 return WIMLIB_ERR_INVALID_DENTRY;
231 ret = symlink(target, output_path);
233 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
234 output_path, target);
235 return WIMLIB_ERR_LINK;
241 * Extracts a directory from the WIM archive.
243 * @dentry: The directory entry for the directory.
244 * @output_path: The path to which the directory is to be extracted to.
245 * @return: True on success, false on failure.
247 static int extract_directory(const char *output_path, bool is_root)
251 ret = stat(output_path, &stbuf);
253 if (S_ISDIR(stbuf.st_mode)) {
255 WARNING("`%s' already exists", output_path);
258 ERROR("`%s' is not a directory", output_path);
259 return WIMLIB_ERR_MKDIR;
262 if (errno != ENOENT) {
263 ERROR_WITH_ERRNO("Failed to stat `%s'", output_path);
264 return WIMLIB_ERR_STAT;
267 /* Compute the output path directory to the directory. */
268 if (mkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP |
269 S_IROTH | S_IXOTH) != 0) {
270 ERROR_WITH_ERRNO("Cannot create directory `%s'",
272 return WIMLIB_ERR_MKDIR;
277 struct extract_args {
280 const char *output_dir;
282 struct SECURITY_API *scapi;
287 * Extracts a file, directory, or symbolic link from the WIM archive. For use
288 * in for_dentry_in_tree().
290 static int extract_dentry(struct dentry *dentry, void *arg)
292 struct extract_args *args = arg;
293 WIMStruct *w = args->w;
294 int extract_flags = args->extract_flags;
295 size_t len = strlen(args->output_dir);
296 char output_path[len + dentry->full_path_utf8_len + 1];
299 if (extract_flags & WIMLIB_EXTRACT_FLAG_VERBOSE) {
300 wimlib_assert(dentry->full_path_utf8);
301 puts(dentry->full_path_utf8);
304 memcpy(output_path, args->output_dir, len);
305 memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
306 output_path[len + dentry->full_path_utf8_len] = '\0';
308 if (dentry_is_symlink(dentry))
309 ret = extract_symlink(dentry, output_path, w);
310 else if (dentry_is_directory(dentry))
311 ret = extract_directory(output_path, dentry_is_root(dentry));
313 ret = extract_regular_file(w, dentry, args->output_dir,
314 output_path, extract_flags);
321 /* Apply timestamp to extracted file */
322 static int apply_dentry_timestamps(struct dentry *dentry, void *arg)
324 struct extract_args *args = arg;
325 size_t len = strlen(args->output_dir);
326 char output_path[len + dentry->full_path_utf8_len + 1];
328 memcpy(output_path, args->output_dir, len);
329 memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
330 output_path[len + dentry->full_path_utf8_len] = '\0';
332 struct timeval tv[2];
333 wim_timestamp_to_timeval(dentry->last_access_time, &tv[0]);
334 wim_timestamp_to_timeval(dentry->last_write_time, &tv[1]);
335 if (lutimes(output_path, tv) != 0) {
336 WARNING("Failed to set timestamp on file `%s': %s",
337 output_path, strerror(errno));
343 static int extract_single_image(WIMStruct *w, int image,
344 const char *output_dir, int extract_flags)
346 DEBUG("Extracting image %d", image);
349 ret = wimlib_select_image(w, image);
353 struct extract_args args = {
355 .extract_flags = extract_flags,
356 .output_dir = output_dir,
362 ret = for_dentry_in_tree(wim_root_dentry(w), extract_dentry, &args);
365 return for_dentry_in_tree_depth(wim_root_dentry(w),
366 apply_dentry_timestamps, &args);
371 /* Extracts all images from the WIM to @output_dir, with the images placed in
372 * subdirectories named by their image names. */
373 static int extract_all_images(WIMStruct *w, const char *output_dir,
376 size_t image_name_max_len = max(xml_get_max_image_name_len(w), 20);
377 size_t output_path_len = strlen(output_dir);
378 char buf[output_path_len + 1 + image_name_max_len + 1];
381 const char *image_name;
383 DEBUG("Attempting to extract all images from `%s'", w->filename);
385 ret = extract_directory(output_dir, true);
389 memcpy(buf, output_dir, output_path_len);
390 buf[output_path_len] = '/';
391 for (image = 1; image <= w->hdr.image_count; image++) {
393 image_name = wimlib_get_image_name(w, image);
395 strcpy(buf + output_path_len + 1, image_name);
397 /* Image name is empty. Use image number instead */
398 sprintf(buf + output_path_len + 1, "%d", image);
400 ret = extract_single_image(w, image, buf, extract_flags);
405 /* Restore original output directory */
406 buf[output_path_len + 1] = '\0';
410 /* Extracts a single image or all images from a WIM file. */
411 WIMLIBAPI int wimlib_extract_image(WIMStruct *w, int image,
412 const char *output_dir, int flags)
415 return WIMLIB_ERR_INVALID_PARAM;
417 if ((flags & (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
418 == (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
419 return WIMLIB_ERR_INVALID_PARAM;
421 for_lookup_table_entry(w->lookup_table, zero_out_refcnts, NULL);
423 if (image == WIM_ALL_IMAGES) {
424 flags |= WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
425 return extract_all_images(w, output_dir, flags);
427 flags &= ~WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
428 return extract_single_image(w, image, output_dir, flags);