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);
50 free_link_group_table(imd->lgt);
52 /* Get rid of the lookup table entry for this image's metadata resource
54 lookup_table_remove(lt, imd->metadata_lte);
58 * Recursively builds a dentry tree from a directory tree on disk, outside the
61 * @root: A dentry that has already been created for the root of the dentry
63 * @source_path: The path to the root of the tree on disk.
64 * @root_stat: A pointer to a `struct stat' that contains the metadata for the
65 * root of the tree on disk.
66 * @lookup_table: The lookup table for the WIM file. For each file added to the
67 * dentry tree being built, an entry is added to the lookup table,
68 * unless an identical file is already in the lookup table. These
69 * lookup table entries that are added point to the file on disk.
71 * @return: 0 on success, nonzero on failure. It is a failure if any of
72 * the files cannot be `stat'ed, or if any of the needed
73 * directories cannot be opened or read. Failure to add the files
74 * to the WIM may still occur later when trying to actually read
75 * the regular files in the tree into the WIM as file resources.
77 static int build_dentry_tree(struct dentry *root, const char *root_disk_path,
78 struct lookup_table* lookup_table,
81 DEBUG("`%s'", root_disk_path);
82 struct stat root_stbuf;
84 int (*stat_fn)(const char *restrict, struct stat *restrict);
86 if (add_flags & WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)
92 ret = (*stat_fn)(root_disk_path, &root_stbuf);
94 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
95 return WIMLIB_ERR_STAT;
98 if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
99 !S_ISDIR(root_stbuf.st_mode)) {
100 ERROR("`%s' is not a directory", root_disk_path);
101 return WIMLIB_ERR_NOTDIR;
103 stbuf_to_dentry(&root_stbuf, root);
104 add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
106 if (dentry_is_directory(root)) {
107 /* Open the directory on disk */
110 struct dentry *child;
112 dir = opendir(root_disk_path);
114 ERROR_WITH_ERRNO("Failed to open the directory `%s'",
116 return WIMLIB_ERR_OPEN;
119 /* Buffer for names of files in directory. */
120 size_t len = strlen(root_disk_path);
121 char name[len + 1 + FILENAME_MAX + 1];
122 memcpy(name, root_disk_path, len);
125 /* Create a dentry for each entry in the directory on disk, and recurse
126 * to any subdirectories. */
127 while ((p = readdir(dir)) != NULL) {
128 if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
129 || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
131 strcpy(name + len + 1, p->d_name);
132 child = new_dentry(p->d_name);
134 ERROR("No memory to allocate new dentry");
135 return WIMLIB_ERR_NOMEM;
137 ret = build_dentry_tree(child, name, lookup_table,
139 link_dentry(child, root);
144 } else if (dentry_is_symlink(root)) {
145 /* Archiving a symbolic link */
146 size_t symlink_buf_len;
147 char deref_name_buf[4096];
148 ssize_t ret = readlink(root_disk_path, deref_name_buf,
149 sizeof(deref_name_buf) - 1);
151 ERROR_WITH_ERRNO("Failed to read target of "
152 "symbolic link `%s'", root_disk_path);
153 return WIMLIB_ERR_STAT;
155 deref_name_buf[ret] = '\0';
156 DEBUG("Read symlink `%s'", deref_name_buf);
157 void *symlink_buf = make_symlink_reparse_data_buf(deref_name_buf,
160 return WIMLIB_ERR_NOMEM;
161 DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
162 symlink_buf_len, ret);
164 u8 symlink_buf_hash[WIM_HASH_SIZE];
165 sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
167 ret = dentry_set_symlink_buf(root, symlink_buf_hash);
173 DEBUG("Created symlink buf");
175 struct lookup_table_entry *lte;
176 struct lookup_table_entry *existing_lte;
178 existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
180 existing_lte->refcnt++;
182 DEBUG("Creating new lookup table entry");
183 lte = new_lookup_table_entry();
186 return WIMLIB_ERR_NOMEM;
188 lte->symlink_buf = symlink_buf;
189 lte->resource_entry.original_size = symlink_buf_len;
190 lte->resource_entry.size = symlink_buf_len;
191 lte->is_symlink = true;
192 memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
193 lookup_table_insert(lookup_table, lte);
197 struct lookup_table_entry *lte;
199 /* For each regular file, we must check to see if the file is in
200 * the lookup table already; if it is, we increment its refcnt;
201 * otherwise, we create a new lookup table entry and insert it.
203 ret = sha1sum(root_disk_path, root->hash);
207 lte = __lookup_resource(lookup_table, root->hash);
211 char *file_on_disk = STRDUP(root_disk_path);
213 ERROR("Failed to allocate memory for file path");
214 return WIMLIB_ERR_NOMEM;
216 lte = new_lookup_table_entry();
219 return WIMLIB_ERR_NOMEM;
221 lte->file_on_disk = file_on_disk;
222 lte->resource_entry.original_size = root_stbuf.st_size;
223 lte->resource_entry.size = root_stbuf.st_size;
224 memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
225 lookup_table_insert(lookup_table, lte);
237 * This function takes in a dentry that was previously located only in image(s)
238 * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
239 * lookup table entry for this file in the lookup table of the destination WIM
240 * file, we simply increment its reference count. Otherwise, a new lookup table
241 * entry is created that references the location of the file resource in the
242 * source WIM file through the other_wim_fp field of the lookup table entry.
244 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
246 WIMStruct *src_wim, *dest_wim;
247 struct lookup_table_entry *src_table_entry;
248 struct lookup_table_entry *dest_table_entry;
250 src_wim = ((struct wim_pair*)arg)->src_wim;
251 dest_wim = ((struct wim_pair*)arg)->dest_wim;
253 if (dentry_is_directory(dentry))
257 src_table_entry = __lookup_resource(src_wim->lookup_table, dentry->hash);
258 if (!src_table_entry)
262 dest_table_entry = __lookup_resource(dest_wim->lookup_table, dentry->hash);
263 if (dest_table_entry) {
264 dest_table_entry->refcnt++;
266 dest_table_entry = new_lookup_table_entry();
267 if (!dest_table_entry)
268 return WIMLIB_ERR_NOMEM;
269 dest_table_entry->other_wim_fp = src_wim->fp;
270 dest_table_entry->other_wim_ctype =
271 wimlib_get_compression_type(src_wim);
272 dest_table_entry->refcnt = 1;
273 memcpy(&dest_table_entry->resource_entry,
274 &src_table_entry->resource_entry,
275 sizeof(struct resource_entry));
276 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
277 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
283 * Adds an image (given by its dentry tree) to the image metadata array of a WIM
284 * file, adds an entry to the lookup table for the image metadata, updates the
285 * image count in the header, and selects the new image.
287 * Does not update the XML data.
289 * @w: The WIMStruct for the WIM file.
290 * @root_dentry: The root of the directory tree for the image.
292 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
294 struct lookup_table_entry *metadata_lte;
295 struct image_metadata *imd;
296 struct image_metadata *new_imd;
297 struct wim_security_data *sd;
299 DEBUG("Reallocating image metadata array for image_count = %u",
300 w->hdr.image_count + 1);
301 imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
304 ERROR("Failed to allocate memory for new image metadata array");
305 return WIMLIB_ERR_NOMEM;
308 memcpy(imd, w->image_metadata,
309 w->hdr.image_count * sizeof(struct image_metadata));
311 metadata_lte = new_lookup_table_entry();
314 sd = CALLOC(1, sizeof(struct wim_security_data));
316 goto out_free_metadata_lte;
318 sd->total_length = 8;
320 metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
321 randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
322 lookup_table_insert(w->lookup_table, metadata_lte);
324 w->hdr.image_count++;
326 new_imd = &imd[w->hdr.image_count - 1];
327 new_imd->metadata_lte = metadata_lte;
328 new_imd->modified = true;
329 new_imd->root_dentry = root_dentry;
330 new_imd->security_data = sd;
331 FREE(w->image_metadata);
332 w->image_metadata = imd;
334 /* Change the current image to the new one. */
335 return wimlib_select_image(w, w->hdr.image_count);
336 out_free_metadata_lte:
340 return WIMLIB_ERR_NOMEM;
345 * Copies an image, or all the images, from a WIM file, into another WIM file.
347 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
350 const char *dest_name,
351 const char *dest_description,
357 struct wim_pair wims;
359 if (src_image == WIM_ALL_IMAGES) {
360 if (src_wim->hdr.image_count > 1) {
362 /* multi-image export. */
364 if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
365 (src_wim->hdr.boot_idx == 0))
367 /* Specifying the boot flag on a multi-image
368 * source WIM makes the boot index default to
369 * the bootable image in the source WIM. It is
370 * an error if there is no such bootable image.
372 ERROR("Cannot specify `boot' flag when "
373 "exporting multiple images from a WIM "
374 "with no bootable images");
375 return WIMLIB_ERR_INVALID_PARAM;
377 if (dest_name || dest_description) {
378 ERROR("Image name or image description was "
379 "specified, but we are exporting "
381 return WIMLIB_ERR_INVALID_PARAM;
383 for (i = 1; i <= src_wim->hdr.image_count; i++) {
384 int export_flags = flags;
386 if (i != src_wim->hdr.boot_idx)
387 export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
389 ret = wimlib_export_image(src_wim, i, dest_wim,
402 ret = wimlib_select_image(src_wim, src_image);
404 ERROR("Could not select image %d from the WIM `%s' "
405 "to export it", src_image, src_wim->filename);
410 dest_name = wimlib_get_image_name(src_wim, src_image);
411 DEBUG("Using name `%s' for source image %d",
412 dest_name, src_image);
415 DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
417 if (wimlib_image_name_in_use(dest_wim, dest_name)) {
418 ERROR("There is already an image named `%s' in the "
419 "destination WIM", dest_name);
420 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
424 /* Cleaning up here on failure would be hard. For example, we could
425 * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
426 * leaving the lookup table entries in the destination WIM in an
427 * inconsistent state. Until these issues can be resolved,
428 * wimlib_export_image() is documented as leaving dest_wim is an
429 * indeterminate state. */
430 root = wim_root_dentry(src_wim);
431 for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
432 wims.src_wim = src_wim;
433 wims.dest_wim = dest_wim;
434 ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
437 ret = add_new_dentry_tree(dest_wim, root);
440 /* Bring over old security data */
441 struct wim_security_data *sd = wim_security_data(src_wim);
442 struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
444 free_security_data(new_imd->security_data);
445 new_imd->security_data = sd;
448 if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
449 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
450 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
453 return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
454 dest_name, dest_description);
458 * Deletes an image from the WIM.
460 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
466 if (image == WIM_ALL_IMAGES) {
467 num_images = w->hdr.image_count;
468 for (i = 1; i <= num_images; i++) {
469 /* Always delete the first image, since by the end
470 * there won't be any more than that! */
471 ret = wimlib_delete_image(w, 1);
478 DEBUG("Deleting image %d", image);
480 /* Even if the dentry tree is not allocated, we must select it (and
481 * therefore allocate it) so that we can decrement the reference counts
482 * in the lookup table. */
483 ret = wimlib_select_image(w, image);
487 /* Free the dentry tree, any lookup table entries that have their
488 * refcnt decremented to 0, and the security data. */
489 destroy_image_metadata(wim_get_current_image_metadata(w),
492 /* Get rid of the empty slot in the image metadata array. */
493 memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
494 (w->hdr.image_count - image) * sizeof(struct image_metadata));
496 /* Decrement the image count. */
497 if (--w->hdr.image_count == 0) {
498 FREE(w->image_metadata);
499 w->image_metadata = NULL;
502 /* Fix the boot index. */
503 if (w->hdr.boot_idx == image)
505 else if (w->hdr.boot_idx > image)
508 w->current_image = WIM_NO_IMAGE;
510 /* Remove the image from the XML information. */
511 xml_delete_image(&w->wim_info, image);
516 * Adds an image to a WIM file from a directory tree on disk.
518 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
519 const char *name, const char *description,
520 const char *flags_element, int flags)
522 struct dentry *root_dentry;
523 struct stat root_stat;
524 struct image_metadata *imd;
527 DEBUG("Adding dentry tree from dir `%s'.", dir);
529 if (!name || !*name) {
530 ERROR("Must specify a non-empty string for the image name");
531 return WIMLIB_ERR_INVALID_PARAM;
534 ERROR("Must specify the name of a directory");
535 return WIMLIB_ERR_INVALID_PARAM;
538 if (wimlib_image_name_in_use(w, name)) {
539 ERROR("There is already an image named \"%s\" in `%s'",
541 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
544 DEBUG("Creating root dentry.");
546 root_dentry = new_dentry("");
548 return WIMLIB_ERR_NOMEM;
549 ret = calculate_dentry_full_path(root_dentry, NULL);
552 goto out_free_dentry_tree;
554 root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
556 DEBUG("Building dentry tree.");
557 ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
558 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
561 ERROR("Failed to build dentry tree for `%s'", dir);
562 goto out_free_dentry_tree;
565 DEBUG("Recalculating full paths of dentries.");
566 ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
568 goto out_free_dentry_tree;
570 ret = add_new_dentry_tree(w, root_dentry);
572 goto out_free_dentry_tree;
574 ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
575 &w->image_metadata[w->hdr.image_count - 1].lgt);
577 goto out_destroy_imd;
578 assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
580 if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
581 wimlib_set_boot_idx(w, w->hdr.image_count);
583 ret = xml_add_image(w, root_dentry, name, description, flags_element);
585 goto out_destroy_imd;
589 destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
592 out_free_dentry_tree:
593 free_dentry_tree(root_dentry, w->lookup_table, true);