4 * Support for modifying WIM files with image-level operations (delete an image,
5 * add an image, export an imagex from one WIM to another.) There is nothing
6 * here that lets you change individual files in the WIM; for that you will need
7 * to look at the filesystem implementation in mount.c.
11 * Copyright (C) 2012 Eric Biggers
13 * This file is part of wimlib, a library for working with WIM files.
15 * wimlib is free software; you can redistribute it and/or modify it under the
16 * terms of the GNU Lesser General Public License as published by the Free
17 * Software Foundation; either version 2.1 of the License, or (at your option)
20 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
21 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
22 * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
25 * You should have received a copy of the GNU Lesser General Public License
26 * along with wimlib; if not, see http://www.gnu.org/licenses/.
29 #include "wimlib_internal.h"
34 #include "lookup_table.h"
41 /** Private flag: Used to mark that we currently adding the root directory of
43 #define WIMLIB_ADD_IMAGE_FLAG_ROOT 0x80000000
45 static void destroy_image_metadata(struct image_metadata *imd,
46 struct lookup_table *lt)
48 free_dentry_tree(imd->root_dentry, lt, true);
49 free_security_data(imd->security_data);
51 /* Get rid of the lookup table entry for this image's metadata resource
53 lookup_table_remove(lt, imd->metadata_lte);
57 * Recursively builds a dentry tree from a directory tree on disk, outside the
60 * @root: A dentry that has already been created for the root of the dentry
62 * @source_path: The path to the root of the tree on disk.
63 * @root_stat: A pointer to a `struct stat' that contains the metadata for the
64 * root of the tree on disk.
65 * @lookup_table: The lookup table for the WIM file. For each file added to the
66 * dentry tree being built, an entry is added to the lookup table,
67 * unless an identical file is already in the lookup table. These
68 * lookup table entries that are added point to the file on disk.
70 * @return: 0 on success, nonzero on failure. It is a failure if any of
71 * the files cannot be `stat'ed, or if any of the needed
72 * directories cannot be opened or read. Failure to add the files
73 * to the WIM may still occur later when trying to actually read
74 * the regular files in the tree into the WIM as file resources.
76 static int build_dentry_tree(struct dentry *root, const char *root_disk_path,
77 struct lookup_table* lookup_table,
80 DEBUG("`%s'", root_disk_path);
81 struct stat root_stbuf;
83 int (*stat_fn)(const char *restrict, struct stat *restrict);
85 if (add_flags & WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)
91 ret = (*stat_fn)(root_disk_path, &root_stbuf);
93 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
94 return WIMLIB_ERR_STAT;
97 if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
98 !S_ISDIR(root_stbuf.st_mode)) {
99 ERROR("`%s' is not a directory", root_disk_path);
100 return WIMLIB_ERR_NOTDIR;
102 stbuf_to_dentry(&root_stbuf, root);
103 add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
105 if (dentry_is_directory(root)) {
106 /* Open the directory on disk */
109 struct dentry *child;
111 dir = opendir(root_disk_path);
113 ERROR_WITH_ERRNO("Failed to open the directory `%s'",
115 return WIMLIB_ERR_OPEN;
118 /* Buffer for names of files in directory. */
119 size_t len = strlen(root_disk_path);
120 char name[len + 1 + FILENAME_MAX + 1];
121 memcpy(name, root_disk_path, len);
124 /* Create a dentry for each entry in the directory on disk, and recurse
125 * to any subdirectories. */
126 while ((p = readdir(dir)) != NULL) {
127 if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
128 || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
130 strcpy(name + len + 1, p->d_name);
131 child = new_dentry(p->d_name);
133 ERROR("No memory to allocate new dentry");
134 return WIMLIB_ERR_NOMEM;
136 ret = build_dentry_tree(child, name, lookup_table,
138 link_dentry(child, root);
143 } else if (dentry_is_symlink(root)) {
144 /* Archiving a symbolic link */
145 size_t symlink_buf_len;
146 char deref_name_buf[4096];
147 ssize_t ret = readlink(root_disk_path, deref_name_buf,
148 sizeof(deref_name_buf) - 1);
150 ERROR_WITH_ERRNO("Failed to read target of "
151 "symbolic link `%s'", root_disk_path);
152 return WIMLIB_ERR_STAT;
154 deref_name_buf[ret] = '\0';
155 DEBUG("Read symlink `%s'", deref_name_buf);
156 void *symlink_buf = make_symlink_reparse_data_buf(deref_name_buf,
159 return WIMLIB_ERR_NOMEM;
160 DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
161 symlink_buf_len, ret);
163 u8 symlink_buf_hash[WIM_HASH_SIZE];
164 sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
166 ret = dentry_set_symlink_buf(root, symlink_buf_hash);
172 DEBUG("Created symlink buf");
174 struct lookup_table_entry *lte;
175 struct lookup_table_entry *existing_lte;
177 existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
179 existing_lte->refcnt++;
181 DEBUG("Creating new lookup table entry");
182 lte = new_lookup_table_entry();
185 return WIMLIB_ERR_NOMEM;
187 lte->symlink_buf = symlink_buf;
188 lte->resource_entry.original_size = symlink_buf_len;
189 lte->resource_entry.size = symlink_buf_len;
190 lte->is_symlink = true;
191 memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
192 lookup_table_insert(lookup_table, lte);
196 struct lookup_table_entry *lte;
198 /* For each regular file, we must check to see if the file is in
199 * the lookup table already; if it is, we increment its refcnt;
200 * otherwise, we create a new lookup table entry and insert it.
202 ret = sha1sum(root_disk_path, root->hash);
206 lte = __lookup_resource(lookup_table, root->hash);
210 char *file_on_disk = STRDUP(root_disk_path);
212 ERROR("Failed to allocate memory for file path");
213 return WIMLIB_ERR_NOMEM;
215 lte = new_lookup_table_entry();
218 return WIMLIB_ERR_NOMEM;
220 lte->file_on_disk = file_on_disk;
221 lte->resource_entry.original_size = root_stbuf.st_size;
222 lte->resource_entry.size = root_stbuf.st_size;
223 memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
224 lookup_table_insert(lookup_table, lte);
236 * This function takes in a dentry that was previously located only in image(s)
237 * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
238 * lookup table entry for this file in the lookup table of the destination WIM
239 * file, we simply increment its reference count. Otherwise, a new lookup table
240 * entry is created that references the location of the file resource in the
241 * source WIM file through the other_wim_fp field of the lookup table entry.
243 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
245 WIMStruct *src_wim, *dest_wim;
246 struct lookup_table_entry *src_table_entry;
247 struct lookup_table_entry *dest_table_entry;
249 src_wim = ((struct wim_pair*)arg)->src_wim;
250 dest_wim = ((struct wim_pair*)arg)->dest_wim;
252 if (dentry_is_directory(dentry))
255 src_table_entry = wim_lookup_resource(src_wim, dentry);
256 if (!src_table_entry)
259 dest_table_entry = wim_lookup_resource(dest_wim, dentry);
260 if (dest_table_entry) {
261 dest_table_entry->refcnt++;
263 dest_table_entry = new_lookup_table_entry();
264 if (!dest_table_entry)
265 return WIMLIB_ERR_NOMEM;
266 dest_table_entry->other_wim_fp = src_wim->fp;
267 dest_table_entry->other_wim_ctype =
268 wimlib_get_compression_type(src_wim);
269 dest_table_entry->refcnt = 1;
270 memcpy(&dest_table_entry->resource_entry,
271 &src_table_entry->resource_entry,
272 sizeof(struct resource_entry));
273 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
274 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
280 * Adds an image (given by its dentry tree) to the image metadata array of a WIM
281 * file, adds an entry to the lookup table for the image metadata, updates the
282 * image count in the header, and selects the new image.
284 * Does not update the XML data.
286 * @w: The WIMStruct for the WIM file.
287 * @root_dentry: The root of the directory tree for the image.
289 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
291 struct lookup_table_entry *metadata_lte;
292 struct image_metadata *imd;
293 struct image_metadata *new_imd;
294 struct wim_security_data *sd;
296 DEBUG("Reallocating image metadata array for image_count = %u",
297 w->hdr.image_count + 1);
298 imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
301 ERROR("Failed to allocate memory for new image metadata array");
302 return WIMLIB_ERR_NOMEM;
305 memcpy(imd, w->image_metadata,
306 w->hdr.image_count * sizeof(struct image_metadata));
308 metadata_lte = new_lookup_table_entry();
311 sd = CALLOC(1, sizeof(struct wim_security_data));
313 goto out_free_metadata_lte;
315 sd->total_length = 8;
317 metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
318 randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
319 lookup_table_insert(w->lookup_table, metadata_lte);
321 w->hdr.image_count++;
323 new_imd = &imd[w->hdr.image_count - 1];
324 new_imd->metadata_lte = metadata_lte;
325 new_imd->modified = true;
326 new_imd->root_dentry = root_dentry;
327 new_imd->security_data = sd;
328 FREE(w->image_metadata);
329 w->image_metadata = imd;
331 /* Change the current image to the new one. */
332 return wimlib_select_image(w, w->hdr.image_count);
333 out_free_metadata_lte:
337 return WIMLIB_ERR_NOMEM;
342 * Copies an image, or all the images, from a WIM file, into another WIM file.
344 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
347 const char *dest_name,
348 const char *dest_description,
354 struct wim_pair wims;
356 if (src_image == WIM_ALL_IMAGES) {
357 if (src_wim->hdr.image_count > 1) {
359 /* multi-image export. */
361 if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
362 (src_wim->hdr.boot_idx == 0))
364 /* Specifying the boot flag on a multi-image
365 * source WIM makes the boot index default to
366 * the bootable image in the source WIM. It is
367 * an error if there is no such bootable image.
369 ERROR("Cannot specify `boot' flag when "
370 "exporting multiple images from a WIM "
371 "with no bootable images");
372 return WIMLIB_ERR_INVALID_PARAM;
374 if (dest_name || dest_description) {
375 ERROR("Image name or image description was "
376 "specified, but we are exporting "
378 return WIMLIB_ERR_INVALID_PARAM;
380 for (i = 1; i <= src_wim->hdr.image_count; i++) {
381 int export_flags = flags;
383 if (i != src_wim->hdr.boot_idx)
384 export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
386 ret = wimlib_export_image(src_wim, i, dest_wim,
399 ret = wimlib_select_image(src_wim, src_image);
401 ERROR("Could not select image %d from the WIM `%s' "
402 "to export it", src_image, src_wim->filename);
407 dest_name = wimlib_get_image_name(src_wim, src_image);
408 DEBUG("Using name `%s' for source image %d",
409 dest_name, src_image);
412 DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
414 if (wimlib_image_name_in_use(dest_wim, dest_name)) {
415 ERROR("There is already an image named `%s' in the "
416 "destination WIM", dest_name);
417 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
421 /* Cleaning up here on failure would be hard. For example, we could
422 * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
423 * leaving the lookup table entries in the destination WIM in an
424 * inconsistent state. Until these issues can be resolved,
425 * wimlib_export_image() is documented as leaving dest_wim is an
426 * indeterminate state. */
427 root = wim_root_dentry(src_wim);
428 for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
429 wims.src_wim = src_wim;
430 wims.dest_wim = dest_wim;
431 ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
434 ret = add_new_dentry_tree(dest_wim, root);
437 /* Bring over old security data */
438 struct wim_security_data *sd = wim_security_data(src_wim);
439 struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
441 free_security_data(new_imd->security_data);
442 new_imd->security_data = sd;
445 if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
446 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
447 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
450 return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
451 dest_name, dest_description);
455 * Deletes an image from the WIM.
457 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
463 if (image == WIM_ALL_IMAGES) {
464 num_images = w->hdr.image_count;
465 for (i = 1; i <= num_images; i++) {
466 /* Always delete the first image, since by the end
467 * there won't be any more than that! */
468 ret = wimlib_delete_image(w, 1);
475 DEBUG("Deleting image %d", image);
477 /* Even if the dentry tree is not allocated, we must select it (and
478 * therefore allocate it) so that we can decrement the reference counts
479 * in the lookup table. */
480 ret = wimlib_select_image(w, image);
484 /* Free the dentry tree, any lookup table entries that have their
485 * refcnt decremented to 0, and the security data. */
486 destroy_image_metadata(wim_get_current_image_metadata(w),
489 /* Get rid of the empty slot in the image metadata array. */
490 memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
491 (w->hdr.image_count - image) * sizeof(struct image_metadata));
493 /* Decrement the image count. */
494 if (--w->hdr.image_count == 0) {
495 FREE(w->image_metadata);
496 w->image_metadata = NULL;
499 /* Fix the boot index. */
500 if (w->hdr.boot_idx == image)
502 else if (w->hdr.boot_idx > image)
505 w->current_image = WIM_NO_IMAGE;
507 /* Remove the image from the XML information. */
508 xml_delete_image(&w->wim_info, image);
513 * Adds an image to a WIM file from a directory tree on disk.
515 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
516 const char *name, const char *description,
517 const char *flags_element, int flags)
519 struct dentry *root_dentry;
520 struct stat root_stat;
521 struct image_metadata *imd;
524 DEBUG("Adding dentry tree from dir `%s'.", dir);
526 if (!name || !*name) {
527 ERROR("Must specify a non-empty string for the image name");
528 return WIMLIB_ERR_INVALID_PARAM;
531 ERROR("Must specify the name of a directory");
532 return WIMLIB_ERR_INVALID_PARAM;
535 if (wimlib_image_name_in_use(w, name)) {
536 ERROR("There is already an image named \"%s\" in `%s'",
538 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
541 DEBUG("Creating root dentry.");
543 root_dentry = new_dentry("");
545 return WIMLIB_ERR_NOMEM;
546 ret = calculate_dentry_full_path(root_dentry, NULL);
549 goto out_free_dentry_tree;
551 root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
553 DEBUG("Building dentry tree.");
554 ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
555 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
558 ERROR("Failed to build dentry tree for `%s'", dir);
559 goto out_free_dentry_tree;
562 DEBUG("Recalculating full paths of dentries.");
563 ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
565 goto out_free_dentry_tree;
567 ret = add_new_dentry_tree(w, root_dentry);
569 goto out_free_dentry_tree;
571 if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
572 wimlib_set_boot_idx(w, w->hdr.image_count);
574 ret = xml_add_image(w, root_dentry, name, description, flags_element);
576 goto out_destroy_imd;
580 destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
583 out_free_dentry_tree:
584 free_dentry_tree(root_dentry, w->lookup_table, true);