4 * A dentry (directory entry) contains the metadata for a file. In the WIM file
5 * format, the dentries are stored in the "metadata resource" section right
6 * after the security data. Each image in the WIM file has its own metadata
7 * resource with its own security data and dentry tree. Dentries in different
8 * images may share file resources by referring to the same lookup table
13 * Copyright (C) 2012 Eric Biggers
15 * This file is part of wimlib, a library for working with WIM files.
17 * wimlib is free software; you can redistribute it and/or modify it under the
18 * terms of the GNU General Public License as published by the Free Software
19 * Foundation; either version 3 of the License, or (at your option) any later
22 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
23 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
24 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License along with
27 * wimlib; if not, see http://www.gnu.org/licenses/.
37 #include "lookup_table.h"
39 #include "timestamp.h"
40 #include "wimlib_internal.h"
43 * Returns true if @dentry has the UTF-8 file name @name that has length
46 static bool dentry_has_name(const struct dentry *dentry, const char *name,
49 if (dentry->file_name_utf8_len != name_len)
51 return memcmp(dentry->file_name_utf8, name, name_len) == 0;
54 static u64 __dentry_correct_length_unaligned(u16 file_name_len,
57 u64 length = WIM_DENTRY_DISK_SIZE;
59 length += file_name_len + 2;
61 length += short_name_len + 2;
65 static u64 dentry_correct_length_unaligned(const struct dentry *dentry)
67 return __dentry_correct_length_unaligned(dentry->file_name_len,
68 dentry->short_name_len);
71 /* Return the "correct" value to write in the length field of the dentry, based
72 * on the file name length and short name length */
73 static u64 dentry_correct_length(const struct dentry *dentry)
75 return (dentry_correct_length_unaligned(dentry) + 7) & ~7;
78 static u64 __dentry_total_length(const struct dentry *dentry, u64 length)
80 for (u16 i = 0; i < dentry->num_ads; i++)
81 length += ads_entry_total_length(&dentry->ads_entries[i]);
82 return (length + 7) & ~7;
85 u64 dentry_correct_total_length(const struct dentry *dentry)
87 return __dentry_total_length(dentry,
88 dentry_correct_length_unaligned(dentry));
91 /* Real length of a dentry, including the alternate data stream entries, which
92 * are not included in the dentry->length field... */
93 u64 dentry_total_length(const struct dentry *dentry)
95 return __dentry_total_length(dentry, dentry->length);
98 /* Transfers file attributes from a `stat' buffer to a struct dentry. */
99 void stbuf_to_dentry(const struct stat *stbuf, struct dentry *dentry)
101 if (S_ISLNK(stbuf->st_mode)) {
102 dentry->attributes = FILE_ATTRIBUTE_REPARSE_POINT;
103 dentry->reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
104 } else if (S_ISDIR(stbuf->st_mode)) {
105 dentry->attributes = FILE_ATTRIBUTE_DIRECTORY;
107 dentry->attributes = FILE_ATTRIBUTE_NORMAL;
109 if (sizeof(ino_t) >= 8)
110 dentry->link_group_id = (u64)stbuf->st_ino;
112 dentry->link_group_id = (u64)stbuf->st_ino |
113 ((u64)stbuf->st_dev << (sizeof(ino_t) * 8));
115 dentry->creation_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
116 dentry->last_write_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
117 dentry->last_access_time = timespec_to_wim_timestamp(&stbuf->st_atim);
121 /* Sets all the timestamp fields of the dentry to the current time. */
122 void dentry_update_all_timestamps(struct dentry *dentry)
124 u64 now = get_wim_timestamp();
125 dentry->creation_time = now;
126 dentry->last_access_time = now;
127 dentry->last_write_time = now;
130 /* Returns the alternate data stream entry belonging to @dentry that has the
131 * stream name @stream_name. */
132 struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
133 const char *stream_name)
135 size_t stream_name_len;
138 if (dentry->num_ads) {
140 stream_name_len = strlen(stream_name);
142 if (ads_entry_has_name(&dentry->ads_entries[i],
143 stream_name, stream_name_len))
144 return &dentry->ads_entries[i];
145 } while (++i != dentry->num_ads);
150 static void ads_entry_init(struct ads_entry *ads_entry)
152 memset(ads_entry, 0, sizeof(struct ads_entry));
153 INIT_LIST_HEAD(&ads_entry->lte_group_list.list);
154 ads_entry->lte_group_list.type = STREAM_TYPE_ADS;
158 * Add an alternate stream entry to a dentry and return a pointer to it, or NULL
159 * if memory could not be allocated.
161 struct ads_entry *dentry_add_ads(struct dentry *dentry, const char *stream_name)
164 struct ads_entry *ads_entries;
165 struct ads_entry *new_entry;
167 DEBUG("Add alternate data stream %s:%s",
168 dentry->file_name_utf8, stream_name);
170 if (dentry->num_ads == 0xffff) {
171 ERROR("Too many alternate data streams in one dentry!");
174 num_ads = dentry->num_ads + 1;
175 ads_entries = REALLOC(dentry->ads_entries,
176 num_ads * sizeof(dentry->ads_entries[0]));
178 ERROR("Failed to allocate memory for new alternate data stream");
181 wimlib_assert(ads_entries == dentry->ads_entries ||
182 ads_entries < dentry->ads_entries ||
183 ads_entries > dentry->ads_entries + dentry->num_ads);
184 if (ads_entries != dentry->ads_entries) {
185 /* We moved the ADS entries. Adjust the stream lists. */
186 for (u16 i = 0; i < dentry->num_ads; i++) {
187 struct list_head *cur = &ads_entries[i].lte_group_list.list;
188 struct list_head *prev = cur->prev;
189 struct list_head *next;
190 if ((u8*)prev >= (u8*)dentry->ads_entries
191 && (u8*)prev < (u8*)(dentry->ads_entries + dentry->num_ads)) {
192 /* Previous entry was located in the same ads_entries
193 * array! Adjust our own prev pointer. */
194 u16 idx = (struct ads_entry*)prev -
195 (struct ads_entry*)&dentry->ads_entries[0].lte_group_list.list;
196 cur->prev = &ads_entries[idx].lte_group_list.list;
198 /* Previous entry is located in a different ads_entries
199 * array. Adjust its next pointer. */
203 if ((u8*)next >= (u8*)dentry->ads_entries
204 && (u8*)next < (u8*)(dentry->ads_entries + dentry->num_ads)) {
205 /* Next entry was located in the same ads_entries array!
206 * Adjust our own next pointer. */
207 u16 idx = (struct ads_entry*)next -
208 (struct ads_entry*)&dentry->ads_entries[0].lte_group_list.list;
209 cur->next = &ads_entries[idx].lte_group_list.list;
211 /* Next entry is located in a different ads_entries
212 * array. Adjust its prev pointer. */
218 new_entry = &ads_entries[num_ads - 1];
219 ads_entry_init(new_entry);
220 if (change_ads_name(new_entry, stream_name) != 0)
222 dentry->ads_entries = ads_entries;
223 dentry->num_ads = num_ads;
227 /* Remove an alternate data stream from a dentry.
229 * The corresponding lookup table entry for the stream is NOT changed.
231 * @dentry: The dentry
232 * @ads_entry: The alternate data stream entry (it MUST be one of the
233 * ads_entry's in the array dentry->ads_entries).
235 void dentry_remove_ads(struct dentry *dentry, struct ads_entry *ads_entry)
240 wimlib_assert(dentry->num_ads);
241 idx = ads_entry - dentry->ads_entries;
242 wimlib_assert(idx < dentry->num_ads);
243 following = dentry->num_ads - idx - 1;
245 destroy_ads_entry(ads_entry);
246 memcpy(ads_entry, ads_entry + 1, following * sizeof(struct ads_entry));
248 /* We moved the ADS entries. Adjust the stream lists. */
249 for (u16 i = 0; i < following; i++) {
250 struct list_head *cur = &ads_entry[i].lte_group_list.list;
251 struct list_head *prev = cur->prev;
252 struct list_head *next;
253 if ((u8*)prev >= (u8*)(ads_entry + 1)
254 && (u8*)prev < (u8*)(ads_entry + following + 1)) {
255 cur->prev = (struct list_head*)((u8*)prev - sizeof(struct ads_entry));
260 if ((u8*)next >= (u8*)(ads_entry + 1)
261 && (u8*)next < (u8*)(ads_entry + following + 1)) {
262 cur->next = (struct list_head*)((u8*)next - sizeof(struct ads_entry));
272 * Calls a function on all directory entries in a directory tree. It is called
273 * on a parent before its children.
275 int for_dentry_in_tree(struct dentry *root,
276 int (*visitor)(struct dentry*, void*), void *arg)
279 struct dentry *child;
281 ret = visitor(root, arg);
286 child = root->children;
292 ret = for_dentry_in_tree(child, visitor, arg);
296 } while (child != root->children);
301 * Like for_dentry_in_tree(), but the visitor function is always called on a
302 * dentry's children before on itself.
304 int for_dentry_in_tree_depth(struct dentry *root,
305 int (*visitor)(struct dentry*, void*), void *arg)
308 struct dentry *child;
311 child = root->children;
315 ret = for_dentry_in_tree_depth(child, visitor, arg);
319 } while (child != root->children);
321 return visitor(root, arg);
325 * Calculate the full path of @dentry, based on its parent's full path and on
326 * its UTF-8 file name.
328 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
332 if (dentry_is_root(dentry)) {
333 full_path = MALLOC(2);
340 char *parent_full_path;
341 u32 parent_full_path_len;
342 const struct dentry *parent = dentry->parent;
344 if (dentry_is_root(parent)) {
345 parent_full_path = "";
346 parent_full_path_len = 0;
348 parent_full_path = parent->full_path_utf8;
349 parent_full_path_len = parent->full_path_utf8_len;
352 full_path_len = parent_full_path_len + 1 +
353 dentry->file_name_utf8_len;
354 full_path = MALLOC(full_path_len + 1);
358 memcpy(full_path, parent_full_path, parent_full_path_len);
359 full_path[parent_full_path_len] = '/';
360 memcpy(full_path + parent_full_path_len + 1,
361 dentry->file_name_utf8,
362 dentry->file_name_utf8_len);
363 full_path[full_path_len] = '\0';
365 FREE(dentry->full_path_utf8);
366 dentry->full_path_utf8 = full_path;
367 dentry->full_path_utf8_len = full_path_len;
370 ERROR("Out of memory while calculating dentry full path");
371 return WIMLIB_ERR_NOMEM;
375 * Recursively calculates the subdir offsets for a directory tree.
377 * @dentry: The root of the directory tree.
378 * @subdir_offset_p: The current subdirectory offset; i.e., the subdirectory
379 * offset for @dentry.
381 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
383 struct dentry *child;
385 child = dentry->children;
386 dentry->subdir_offset = *subdir_offset_p;
389 /* Advance the subdir offset by the amount of space the children
390 * of this dentry take up. */
392 *subdir_offset_p += dentry_correct_total_length(child);
394 } while (child != dentry->children);
396 /* End-of-directory dentry on disk. */
397 *subdir_offset_p += 8;
399 /* Recursively call calculate_subdir_offsets() on all the
402 calculate_subdir_offsets(child, subdir_offset_p);
404 } while (child != dentry->children);
406 /* On disk, childless directories have a valid subdir_offset
407 * that points to an 8-byte end-of-directory dentry. Regular
408 * files or reparse points have a subdir_offset of 0. */
409 if (dentry_is_directory(dentry))
410 *subdir_offset_p += 8;
412 dentry->subdir_offset = 0;
417 /* Returns the child of @dentry that has the file name @name.
418 * Returns NULL if no child has the name. */
419 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
422 struct dentry *child;
425 child = dentry->children;
427 name_len = strlen(name);
429 if (dentry_has_name(child, name, name_len))
432 } while (child != dentry->children);
437 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
438 * @cur_dir. Returns NULL if no dentry having the path is found. */
439 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir,
442 struct dentry *child;
444 const char *new_path;
449 child = cur_dir->children;
451 new_path = path_next_part(path, &base_len);
453 if (dentry_has_name(child, path, base_len))
454 return get_dentry_relative_path(child, new_path);
456 } while (child != cur_dir->children);
461 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
463 struct dentry *get_dentry(WIMStruct *w, const char *path)
465 struct dentry *root = wim_root_dentry(w);
468 return get_dentry_relative_path(root, path);
471 /* Returns the dentry that corresponds to the parent directory of @path, or NULL
472 * if the dentry is not found. */
473 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
475 size_t path_len = strlen(path);
476 char buf[path_len + 1];
478 memcpy(buf, path, path_len + 1);
480 to_parent_name(buf, path_len);
482 return get_dentry(w, buf);
485 /* Prints the full path of a dentry. */
486 int print_dentry_full_path(struct dentry *dentry, void *ignore)
488 if (dentry->full_path_utf8)
489 puts(dentry->full_path_utf8);
493 /* We want to be able to show the names of the file attribute flags that are
495 struct file_attr_flag {
499 struct file_attr_flag file_attr_flags[] = {
500 {FILE_ATTRIBUTE_READONLY, "READONLY"},
501 {FILE_ATTRIBUTE_HIDDEN, "HIDDEN"},
502 {FILE_ATTRIBUTE_SYSTEM, "SYSTEM"},
503 {FILE_ATTRIBUTE_DIRECTORY, "DIRECTORY"},
504 {FILE_ATTRIBUTE_ARCHIVE, "ARCHIVE"},
505 {FILE_ATTRIBUTE_DEVICE, "DEVICE"},
506 {FILE_ATTRIBUTE_NORMAL, "NORMAL"},
507 {FILE_ATTRIBUTE_TEMPORARY, "TEMPORARY"},
508 {FILE_ATTRIBUTE_SPARSE_FILE, "SPARSE_FILE"},
509 {FILE_ATTRIBUTE_REPARSE_POINT, "REPARSE_POINT"},
510 {FILE_ATTRIBUTE_COMPRESSED, "COMPRESSED"},
511 {FILE_ATTRIBUTE_OFFLINE, "OFFLINE"},
512 {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
513 {FILE_ATTRIBUTE_ENCRYPTED, "ENCRYPTED"},
514 {FILE_ATTRIBUTE_VIRTUAL, "VIRTUAL"},
517 /* Prints a directory entry. @lookup_table is a pointer to the lookup table, if
518 * available. If the dentry is unresolved and the lookup table is NULL, the
519 * lookup table entries will not be printed. Otherwise, they will be. */
520 int print_dentry(struct dentry *dentry, void *lookup_table)
523 struct lookup_table_entry *lte;
527 printf("[DENTRY]\n");
528 printf("Length = %"PRIu64"\n", dentry->length);
529 printf("Attributes = 0x%x\n", dentry->attributes);
530 for (unsigned i = 0; i < ARRAY_LEN(file_attr_flags); i++)
531 if (file_attr_flags[i].flag & dentry->attributes)
532 printf(" FILE_ATTRIBUTE_%s is set\n",
533 file_attr_flags[i].name);
534 printf("Security ID = %d\n", dentry->security_id);
535 printf("Subdir offset = %"PRIu64"\n", dentry->subdir_offset);
537 printf("Unused1 = 0x%"PRIu64"\n", dentry->unused1);
538 printf("Unused2 = %"PRIu64"\n", dentry->unused2);
541 printf("Creation Time = 0x%"PRIx64"\n");
542 printf("Last Access Time = 0x%"PRIx64"\n");
543 printf("Last Write Time = 0x%"PRIx64"\n");
546 /* Translate the timestamps into something readable */
547 time = wim_timestamp_to_unix(dentry->creation_time);
548 p = asctime(gmtime(&time));
549 *(strrchr(p, '\n')) = '\0';
550 printf("Creation Time = %s UTC\n", p);
552 time = wim_timestamp_to_unix(dentry->last_access_time);
553 p = asctime(gmtime(&time));
554 *(strrchr(p, '\n')) = '\0';
555 printf("Last Access Time = %s UTC\n", p);
557 time = wim_timestamp_to_unix(dentry->last_write_time);
558 p = asctime(gmtime(&time));
559 *(strrchr(p, '\n')) = '\0';
560 printf("Last Write Time = %s UTC\n", p);
562 printf("Reparse Tag = 0x%"PRIx32"\n", dentry->reparse_tag);
563 printf("Hard Link Group = 0x%"PRIx64"\n", dentry->link_group_id);
564 printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
565 printf("Filename = \"");
566 print_string(dentry->file_name, dentry->file_name_len);
568 printf("Filename Length = %hu\n", dentry->file_name_len);
569 printf("Filename (UTF-8) = \"%s\"\n", dentry->file_name_utf8);
570 printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
571 printf("Short Name = \"");
572 print_string(dentry->short_name, dentry->short_name_len);
574 printf("Short Name Length = %hu\n", dentry->short_name_len);
575 printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
576 lte = dentry_stream_lte(dentry, 0, lookup_table);
578 print_lookup_table_entry(lte);
580 hash = dentry_stream_hash(dentry, 0);
588 for (u16 i = 0; i < dentry->num_ads; i++) {
589 printf("[Alternate Stream Entry %u]\n", i);
590 printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
591 printf("Name Length (UTF-16) = %u\n",
592 dentry->ads_entries[i].stream_name_len);
593 hash = dentry_stream_hash(dentry, i + 1);
599 print_lookup_table_entry(dentry_stream_lte(dentry, i + 1,
605 /* Initializations done on every `struct dentry'. */
606 static void dentry_common_init(struct dentry *dentry)
608 memset(dentry, 0, sizeof(struct dentry));
610 dentry->security_id = -1;
611 dentry->ads_entries_status = ADS_ENTRIES_DEFAULT;
612 dentry->lte_group_list.type = STREAM_TYPE_NORMAL;
616 * Creates an unlinked directory entry.
618 * @name: The UTF-8 filename of the new dentry.
620 * Returns a pointer to the new dentry, or NULL if out of memory.
622 struct dentry *new_dentry(const char *name)
624 struct dentry *dentry;
626 dentry = MALLOC(sizeof(struct dentry));
630 dentry_common_init(dentry);
631 if (change_dentry_name(dentry, name) != 0)
634 dentry_update_all_timestamps(dentry);
635 dentry->next = dentry;
636 dentry->prev = dentry;
637 dentry->parent = dentry;
638 INIT_LIST_HEAD(&dentry->link_group_list);
639 INIT_LIST_HEAD(&dentry->lte_group_list.list);
643 ERROR("Failed to allocate new dentry");
647 void dentry_free_ads_entries(struct dentry *dentry)
649 for (u16 i = 0; i < dentry->num_ads; i++)
650 destroy_ads_entry(&dentry->ads_entries[i]);
651 FREE(dentry->ads_entries);
652 dentry->ads_entries = NULL;
656 static void __destroy_dentry(struct dentry *dentry)
658 FREE(dentry->file_name);
659 FREE(dentry->file_name_utf8);
660 FREE(dentry->short_name);
661 FREE(dentry->full_path_utf8);
662 if (dentry->extracted_file != dentry->full_path_utf8)
663 FREE(dentry->extracted_file);
666 /* Frees a WIM dentry. */
667 void free_dentry(struct dentry *dentry)
669 wimlib_assert(dentry);
670 __destroy_dentry(dentry);
671 /* Don't destroy the ADS entries if they "belong" to a different dentry
673 if (dentry->ads_entries_status != ADS_ENTRIES_USER)
674 dentry_free_ads_entries(dentry);
678 /* Like free_dentry(), but assigns a new ADS entries owner if this dentry was
679 * the previous owner, and also deletes the dentry from its link_group_list */
680 void put_dentry(struct dentry *dentry)
682 if (dentry->ads_entries_status == ADS_ENTRIES_OWNER) {
683 struct dentry *new_owner;
684 list_for_each_entry(new_owner, &dentry->link_group_list,
687 if (new_owner->ads_entries_status == ADS_ENTRIES_USER) {
688 new_owner->ads_entries_status = ADS_ENTRIES_OWNER;
692 dentry->ads_entries_status = ADS_ENTRIES_USER;
694 list_del(&dentry->link_group_list);
699 /* Partically clones a dentry.
702 * - memory for file names is not cloned (the pointers are all set to NULL
703 * and the lengths are set to zero)
704 * - next, prev, and children pointers and not touched
705 * - stream entries are not cloned (pointer left untouched).
707 struct dentry *clone_dentry(struct dentry *old)
709 struct dentry *new = MALLOC(sizeof(struct dentry));
712 memcpy(new, old, sizeof(struct dentry));
713 new->file_name = NULL;
714 new->file_name_len = 0;
715 new->file_name_utf8 = NULL;
716 new->file_name_utf8_len = 0;
717 new->short_name = NULL;
718 new->short_name_len = 0;
723 * This function is passed as an argument to for_dentry_in_tree_depth() in order
724 * to free a directory tree. __args is a pointer to a `struct free_dentry_args'.
726 static int do_free_dentry(struct dentry *dentry, void *__lookup_table)
728 struct lookup_table *lookup_table = __lookup_table;
729 struct lookup_table_entry *lte;
733 for (i = 0; i <= dentry->num_ads; i++) {
734 lte = dentry_stream_lte(dentry, i, lookup_table);
735 lte_decrement_refcnt(lte, lookup_table);
739 wimlib_assert(dentry->refcnt != 0);
740 if (--dentry->refcnt == 0)
746 * Unlinks and frees a dentry tree.
748 * @root: The root of the tree.
749 * @lookup_table: The lookup table for dentries. If non-NULL, the
750 * reference counts in the lookup table for the lookup
751 * table entries corresponding to the dentries will be
754 void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table)
756 if (!root || !root->parent)
758 for_dentry_in_tree_depth(root, do_free_dentry, lookup_table);
761 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
768 * Links a dentry into the directory tree.
770 * @dentry: The dentry to link.
771 * @parent: The dentry that will be the parent of @dentry.
773 void link_dentry(struct dentry *dentry, struct dentry *parent)
775 wimlib_assert(dentry_is_directory(parent));
776 dentry->parent = parent;
777 if (parent->children) {
778 /* Not an only child; link to siblings. */
779 dentry->next = parent->children;
780 dentry->prev = parent->children->prev;
781 dentry->next->prev = dentry;
782 dentry->prev->next = dentry;
784 /* Only child; link to parent. */
785 parent->children = dentry;
786 dentry->next = dentry;
787 dentry->prev = dentry;
792 /* Unlink a dentry from the directory tree.
794 * Note: This merely removes it from the in-memory tree structure. See
795 * remove_dentry() in mount.c for a function implemented on top of this one that
796 * frees the dentry and implements reference counting for the lookup table
798 void unlink_dentry(struct dentry *dentry)
800 if (dentry_is_root(dentry))
802 if (dentry_is_only_child(dentry)) {
803 dentry->parent->children = NULL;
805 if (dentry_is_first_sibling(dentry))
806 dentry->parent->children = dentry->next;
807 dentry->next->prev = dentry->prev;
808 dentry->prev->next = dentry->next;
812 /* Duplicates a UTF-8 name into UTF-8 and UTF-16 strings and returns the strings
813 * and their lengths in the pointer arguments */
814 int get_names(char **name_utf16_ret, char **name_utf8_ret,
815 u16 *name_utf16_len_ret, u16 *name_utf8_len_ret,
820 char *name_utf16, *name_utf8;
822 utf8_len = strlen(name);
824 name_utf16 = utf8_to_utf16(name, utf8_len, &utf16_len);
827 return WIMLIB_ERR_NOMEM;
829 name_utf8 = MALLOC(utf8_len + 1);
832 return WIMLIB_ERR_NOMEM;
834 memcpy(name_utf8, name, utf8_len + 1);
835 FREE(*name_utf8_ret);
836 FREE(*name_utf16_ret);
837 *name_utf8_ret = name_utf8;
838 *name_utf16_ret = name_utf16;
839 *name_utf8_len_ret = utf8_len;
840 *name_utf16_len_ret = utf16_len;
844 /* Changes the name of a dentry to @new_name. Only changes the file_name and
845 * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
846 * full_path_utf8 fields. Also recalculates its length. */
847 int change_dentry_name(struct dentry *dentry, const char *new_name)
851 ret = get_names(&dentry->file_name, &dentry->file_name_utf8,
852 &dentry->file_name_len, &dentry->file_name_utf8_len,
854 FREE(dentry->short_name);
855 dentry->short_name_len = 0;
857 dentry->length = dentry_correct_length(dentry);
862 * Changes the name of an alternate data stream */
863 int change_ads_name(struct ads_entry *entry, const char *new_name)
865 return get_names(&entry->stream_name, &entry->stream_name_utf8,
866 &entry->stream_name_len,
867 &entry->stream_name_utf8_len,
871 /* Parameters for calculate_dentry_statistics(). */
872 struct image_statistics {
873 struct lookup_table *lookup_table;
877 u64 *hard_link_bytes;
880 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
882 struct image_statistics *stats;
883 struct lookup_table_entry *lte;
887 if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
890 ++*stats->file_count;
892 for (unsigned i = 0; i <= dentry->num_ads; i++) {
893 lte = dentry_stream_lte(dentry, i, stats->lookup_table);
895 *stats->total_bytes += wim_resource_size(lte);
896 if (++lte->out_refcnt == 1)
897 *stats->hard_link_bytes += wim_resource_size(lte);
903 /* Calculates some statistics about a dentry tree. */
904 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
905 u64 *dir_count_ret, u64 *file_count_ret,
906 u64 *total_bytes_ret,
907 u64 *hard_link_bytes_ret)
909 struct image_statistics stats;
912 *total_bytes_ret = 0;
913 *hard_link_bytes_ret = 0;
914 stats.lookup_table = table;
915 stats.dir_count = dir_count_ret;
916 stats.file_count = file_count_ret;
917 stats.total_bytes = total_bytes_ret;
918 stats.hard_link_bytes = hard_link_bytes_ret;
919 for_lookup_table_entry(table, zero_out_refcnts, NULL);
920 for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
925 * Reads the alternate data stream entries for a dentry.
927 * @p: Pointer to buffer that starts with the first alternate stream entry.
929 * @dentry: Dentry to load the alternate data streams into.
930 * @dentry->num_ads must have been set to the number of
931 * alternate data streams that are expected.
933 * @remaining_size: Number of bytes of data remaining in the buffer pointed
936 * The format of the on-disk alternate stream entries is as follows:
938 * struct ads_entry_on_disk {
939 * u64 length; // Length of the entry, in bytes. This includes
940 * all fields (including the stream name and
941 * null terminator if present, AND the padding!).
942 * u64 reserved; // Seems to be unused
943 * u8 hash[20]; // SHA1 message digest of the uncompressed stream
944 * u16 stream_name_len; // Length of the stream name, in bytes
945 * char stream_name[]; // Stream name in UTF-16LE, @stream_name_len bytes long,
946 * not including null terminator
947 * u16 zero; // UTF-16 null terminator for the stream name, NOT
948 * included in @stream_name_len. Based on what
949 * I've observed from filenames in dentries,
950 * this field should not exist when
951 * (@stream_name_len == 0), but you can't
952 * actually tell because of the padding anyway
953 * (provided that the padding is zeroed, which
954 * it always seems to be).
955 * char padding[]; // Padding to make the size a multiple of 8 bytes.
958 * In addition, the entries are 8-byte aligned.
960 * Return 0 on success or nonzero on failure. On success, dentry->ads_entries
961 * is set to an array of `struct ads_entry's of length dentry->num_ads. On
962 * failure, @dentry is not modified.
964 static int read_ads_entries(const u8 *p, struct dentry *dentry,
968 struct ads_entry *ads_entries;
971 num_ads = dentry->num_ads;
972 ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
974 ERROR("Could not allocate memory for %"PRIu16" "
975 "alternate data stream entries", num_ads);
976 return WIMLIB_ERR_NOMEM;
979 for (u16 i = 0; i < num_ads; i++) {
980 struct ads_entry *cur_entry = &ads_entries[i];
982 u64 length_no_padding;
985 const u8 *p_save = p;
987 /* Read the base stream entry, excluding the stream name. */
988 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
989 ERROR("Stream entries go past end of metadata resource");
990 ERROR("(remaining_size = %"PRIu64")", remaining_size);
991 ret = WIMLIB_ERR_INVALID_DENTRY;
992 goto out_free_ads_entries;
995 p = get_u64(p, &length);
996 p += 8; /* Skip the reserved field */
997 p = get_bytes(p, SHA1_HASH_SIZE, (u8*)cur_entry->hash);
998 p = get_u16(p, &cur_entry->stream_name_len);
1000 cur_entry->stream_name = NULL;
1001 cur_entry->stream_name_utf8 = NULL;
1003 /* Length including neither the null terminator nor the padding
1005 length_no_padding = WIM_ADS_ENTRY_DISK_SIZE +
1006 cur_entry->stream_name_len;
1008 /* Length including the null terminator and the padding */
1009 total_length = ((length_no_padding + 2) + 7) & ~7;
1011 wimlib_assert(total_length == ads_entry_total_length(cur_entry));
1013 if (remaining_size < length_no_padding) {
1014 ERROR("Stream entries go past end of metadata resource");
1015 ERROR("(remaining_size = %"PRIu64" bytes, "
1016 "length_no_padding = %"PRIu64" bytes)",
1017 remaining_size, length_no_padding);
1018 ret = WIMLIB_ERR_INVALID_DENTRY;
1019 goto out_free_ads_entries;
1022 /* The @length field in the on-disk ADS entry is expected to be
1023 * equal to @total_length, which includes all of the entry and
1024 * the padding that follows it to align the next ADS entry to an
1025 * 8-byte boundary. However, to be safe, we'll accept the
1026 * length field as long as it's not less than the un-padded
1027 * total length and not more than the padded total length. */
1028 if (length < length_no_padding || length > total_length) {
1029 ERROR("Stream entry has unexpected length "
1030 "field (length field = %"PRIu64", "
1031 "unpadded total length = %"PRIu64", "
1032 "padded total length = %"PRIu64")",
1033 length, length_no_padding, total_length);
1034 ret = WIMLIB_ERR_INVALID_DENTRY;
1035 goto out_free_ads_entries;
1038 if (cur_entry->stream_name_len) {
1039 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
1040 if (!cur_entry->stream_name) {
1041 ret = WIMLIB_ERR_NOMEM;
1042 goto out_free_ads_entries;
1044 get_bytes(p, cur_entry->stream_name_len,
1045 (u8*)cur_entry->stream_name);
1046 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
1047 cur_entry->stream_name_len,
1049 cur_entry->stream_name_utf8_len = utf8_len;
1051 if (!cur_entry->stream_name_utf8) {
1052 ret = WIMLIB_ERR_NOMEM;
1053 goto out_free_ads_entries;
1056 /* It's expected that the size of every ADS entry is a multiple
1057 * of 8. However, to be safe, I'm allowing the possibility of
1058 * an ADS entry at the very end of the metadata resource ending
1059 * un-aligned. So although we still need to increment the input
1060 * pointer by @total_length to reach the next ADS entry, it's
1061 * possible that less than @total_length is actually remaining
1062 * in the metadata resource. We should set the remaining size to
1063 * 0 bytes if this happens. */
1064 p = p_save + total_length;
1065 if (remaining_size < total_length)
1068 remaining_size -= total_length;
1070 dentry->ads_entries = ads_entries;
1072 out_free_ads_entries:
1073 for (u16 i = 0; i < num_ads; i++) {
1074 FREE(ads_entries[i].stream_name);
1075 FREE(ads_entries[i].stream_name_utf8);
1082 * Reads a directory entry, including all alternate data stream entries that
1083 * follow it, from the WIM image's metadata resource.
1085 * @metadata_resource: Buffer containing the uncompressed metadata resource.
1086 * @metadata_resource_len: Length of the metadata resource.
1087 * @offset: Offset of this directory entry in the metadata resource.
1088 * @dentry: A `struct dentry' that will be filled in by this function.
1090 * Return 0 on success or nonzero on failure. On failure, @dentry have been
1091 * modified, bu it will be left with no pointers to any allocated buffers.
1092 * On success, the dentry->length field must be examined. If zero, this was a
1093 * special "end of directory" dentry and not a real dentry. If nonzero, this
1094 * was a real dentry.
1096 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
1097 u64 offset, struct dentry *dentry)
1100 u64 calculated_size;
1101 char *file_name = NULL;
1102 char *file_name_utf8 = NULL;
1103 char *short_name = NULL;
1106 size_t file_name_utf8_len = 0;
1109 dentry_common_init(dentry);
1111 /*Make sure the dentry really fits into the metadata resource.*/
1112 if (offset + 8 > metadata_resource_len || offset + 8 < offset) {
1113 ERROR("Directory entry starting at %"PRIu64" ends past the "
1114 "end of the metadata resource (size %"PRIu64")",
1115 offset, metadata_resource_len);
1116 return WIMLIB_ERR_INVALID_DENTRY;
1119 /* Before reading the whole dentry, we need to read just the length.
1120 * This is because a dentry of length 8 (that is, just the length field)
1121 * terminates the list of sibling directory entries. */
1123 p = get_u64(&metadata_resource[offset], &dentry->length);
1125 /* A zero length field (really a length of 8, since that's how big the
1126 * directory entry is...) indicates that this is the end of directory
1127 * dentry. We do not read it into memory as an actual dentry, so just
1128 * return successfully in that case. */
1129 if (dentry->length == 0)
1132 /* If the dentry does not overflow the metadata resource buffer and is
1133 * not too short, read the rest of it (excluding the alternate data
1134 * streams, but including the file name and short name variable-length
1135 * fields) into memory. */
1136 if (offset + dentry->length >= metadata_resource_len
1137 || offset + dentry->length < offset)
1139 ERROR("Directory entry at offset %"PRIu64" and with size "
1140 "%"PRIu64" ends past the end of the metadata resource "
1142 offset, dentry->length, metadata_resource_len);
1143 return WIMLIB_ERR_INVALID_DENTRY;
1146 if (dentry->length < WIM_DENTRY_DISK_SIZE) {
1147 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
1149 return WIMLIB_ERR_INVALID_DENTRY;
1152 p = get_u32(p, &dentry->attributes);
1153 p = get_u32(p, (u32*)&dentry->security_id);
1154 p = get_u64(p, &dentry->subdir_offset);
1156 /* 2 unused fields */
1157 p += 2 * sizeof(u64);
1158 /*p = get_u64(p, &dentry->unused1);*/
1159 /*p = get_u64(p, &dentry->unused2);*/
1161 p = get_u64(p, &dentry->creation_time);
1162 p = get_u64(p, &dentry->last_access_time);
1163 p = get_u64(p, &dentry->last_write_time);
1165 p = get_bytes(p, SHA1_HASH_SIZE, dentry->hash);
1168 * I don't know what's going on here. It seems like M$ screwed up the
1169 * reparse points, then put the fields in the same place and didn't
1170 * document it. The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
1171 * have something to do with this, but it's not documented.
1173 if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1176 p = get_u32(p, &dentry->reparse_tag);
1179 p = get_u32(p, &dentry->reparse_tag);
1180 p = get_u64(p, &dentry->link_group_id);
1183 /* By the way, the reparse_reserved field does not actually exist (at
1184 * least when the file is not a reparse point) */
1186 p = get_u16(p, &dentry->num_ads);
1188 p = get_u16(p, &short_name_len);
1189 p = get_u16(p, &file_name_len);
1191 /* We now know the length of the file name and short name. Make sure
1192 * the length of the dentry is large enough to actually hold them.
1194 * The calculated length here is unaligned to allow for the possibility
1195 * that the dentry->length names an unaligned length, although this
1196 * would be unexpected. */
1197 calculated_size = __dentry_correct_length_unaligned(file_name_len,
1200 if (dentry->length < calculated_size) {
1201 ERROR("Unexpected end of directory entry! (Expected "
1202 "at least %"PRIu64" bytes, got %"PRIu64" bytes. "
1203 "short_name_len = %hu, file_name_len = %hu)",
1204 calculated_size, dentry->length,
1205 short_name_len, file_name_len);
1206 return WIMLIB_ERR_INVALID_DENTRY;
1209 /* Read the filename if present. Note: if the filename is empty, there
1210 * is no null terminator following it. */
1211 if (file_name_len) {
1212 file_name = MALLOC(file_name_len);
1214 ERROR("Failed to allocate %hu bytes for dentry file name",
1216 return WIMLIB_ERR_NOMEM;
1218 p = get_bytes(p, file_name_len, file_name);
1220 /* Convert filename to UTF-8. */
1221 file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
1222 &file_name_utf8_len);
1224 if (!file_name_utf8) {
1225 ERROR("Failed to allocate memory to convert UTF-16 "
1226 "filename (%hu bytes) to UTF-8", file_name_len);
1227 ret = WIMLIB_ERR_NOMEM;
1228 goto out_free_file_name;
1231 WARNING("Expected two zero bytes following the file name "
1232 "`%s', but found non-zero bytes", file_name_utf8);
1236 /* Align the calculated size */
1237 calculated_size = (calculated_size + 7) & ~7;
1239 if (dentry->length > calculated_size) {
1240 /* Weird; the dentry says it's longer than it should be. Note
1241 * that the length field does NOT include the size of the
1242 * alternate stream entries. */
1244 /* Strangely, some directory entries inexplicably have a little
1245 * over 70 bytes of extra data. The exact amount of data seems
1246 * to be 72 bytes, but it is aligned on the next 8-byte
1247 * boundary. It does NOT seem to be alternate data stream
1248 * entries. Here's an example of the aligned data:
1250 * 01000000 40000000 6c786bba c58ede11 b0bb0026 1870892a b6adb76f
1251 * e63a3e46 8fca8653 0d2effa1 6c786bba c58ede11 b0bb0026 1870892a
1252 * 00000000 00000000 00000000 00000000
1254 * Here's one interpretation of how the data is laid out.
1257 * u32 field1; (always 0x00000001)
1258 * u32 field2; (always 0x40000000)
1259 * u8 data[48]; (???)
1260 * u64 reserved1; (always 0)
1261 * u64 reserved2; (always 0)
1263 DEBUG("Dentry for file or directory `%s' has %zu extra "
1265 file_name_utf8, dentry->length - calculated_size);
1268 /* Read the short filename if present. Note: if there is no short
1269 * filename, there is no null terminator following it. */
1270 if (short_name_len) {
1271 short_name = MALLOC(short_name_len);
1273 ERROR("Failed to allocate %hu bytes for short filename",
1275 ret = WIMLIB_ERR_NOMEM;
1276 goto out_free_file_name_utf8;
1279 p = get_bytes(p, short_name_len, short_name);
1281 WARNING("Expected two zero bytes following the file name "
1282 "`%s', but found non-zero bytes", file_name_utf8);
1287 * Read the alternate data streams, if present. dentry->num_ads tells
1288 * us how many they are, and they will directly follow the dentry
1291 * Note that each alternate data stream entry begins on an 8-byte
1292 * aligned boundary, and the alternate data stream entries are NOT
1293 * included in the dentry->length field for some reason.
1295 if (dentry->num_ads != 0) {
1296 if (calculated_size > metadata_resource_len - offset) {
1297 ERROR("Not enough space in metadata resource for "
1298 "alternate stream entries");
1299 ret = WIMLIB_ERR_INVALID_DENTRY;
1300 goto out_free_short_name;
1302 ret = read_ads_entries(&metadata_resource[offset + calculated_size],
1304 metadata_resource_len - offset - calculated_size);
1306 goto out_free_short_name;
1309 /* We've read all the data for this dentry. Set the names and their
1310 * lengths, and we've done. */
1311 dentry->file_name = file_name;
1312 dentry->file_name_utf8 = file_name_utf8;
1313 dentry->short_name = short_name;
1314 dentry->file_name_len = file_name_len;
1315 dentry->file_name_utf8_len = file_name_utf8_len;
1316 dentry->short_name_len = short_name_len;
1318 out_free_short_name:
1320 out_free_file_name_utf8:
1321 FREE(file_name_utf8);
1327 /* Run some miscellaneous verifications on a WIM dentry */
1328 int verify_dentry(struct dentry *dentry, void *wim)
1330 const WIMStruct *w = wim;
1331 const struct lookup_table *table = w->lookup_table;
1332 const struct wim_security_data *sd = wim_const_security_data(w);
1333 int ret = WIMLIB_ERR_INVALID_DENTRY;
1335 /* Check the security ID */
1336 if (dentry->security_id < -1) {
1337 ERROR("Dentry `%s' has an invalid security ID (%d)",
1338 dentry->full_path_utf8, dentry->security_id);
1341 if (dentry->security_id >= sd->num_entries) {
1342 ERROR("Dentry `%s' has an invalid security ID (%d) "
1343 "(there are only %u entries in the security table)",
1344 dentry->full_path_utf8, dentry->security_id,
1349 /* Check that lookup table entries for all the resources exist, except
1350 * if the SHA1 message digest is all 0's, which indicates there is
1351 * intentionally no resource there. */
1352 if (w->hdr.total_parts == 1) {
1353 for (unsigned i = 0; i <= dentry->num_ads; i++) {
1354 struct lookup_table_entry *lte;
1356 hash = dentry_stream_hash_unresolved(dentry, i);
1357 lte = __lookup_resource(table, hash);
1358 if (!lte && !is_zero_hash(hash)) {
1359 ERROR("Could not find lookup table entry for stream "
1360 "%u of dentry `%s'", i, dentry->full_path_utf8);
1366 /* Make sure there is only one un-named stream. */
1367 unsigned num_unnamed_streams = 0;
1368 for (unsigned i = 0; i <= dentry->num_ads; i++) {
1370 hash = dentry_stream_hash_unresolved(dentry, i);
1371 if (!dentry_stream_name_len(dentry, i) && !is_zero_hash(hash))
1372 num_unnamed_streams++;
1374 if (num_unnamed_streams > 1) {
1375 ERROR("Dentry `%s' has multiple (%u) un-named streams",
1376 dentry->full_path_utf8, num_unnamed_streams);
1380 /* Cannot have a short name but no long name */
1381 if (dentry->short_name_len && !dentry->file_name_len) {
1382 ERROR("Dentry `%s' has a short name but no long name",
1383 dentry->full_path_utf8);
1387 /* Make sure root dentry is unnamed */
1388 if (dentry_is_root(dentry)) {
1389 if (dentry->file_name_len) {
1390 ERROR("The root dentry is named `%s', but it must "
1391 "be unnamed", dentry->file_name_utf8);
1397 /* Check timestamps */
1398 if (dentry->last_access_time < dentry->creation_time ||
1399 dentry->last_write_time < dentry->creation_time) {
1400 WARNING("Dentry `%s' was created after it was last accessed or "
1401 "written to", dentry->full_path_utf8);
1411 * Writes a WIM dentry to an output buffer.
1413 * @dentry: The dentry structure.
1414 * @p: The memory location to write the data to.
1415 * @return: Pointer to the byte after the last byte we wrote as part of the
1418 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
1423 /* We calculate the correct length of the dentry ourselves because the
1424 * dentry->length field may been set to an unexpected value from when we
1425 * read the dentry in (for example, there may have been unknown data
1426 * appended to the end of the dentry...) */
1427 u64 length = dentry_correct_length(dentry);
1429 p = put_u64(p, length);
1430 p = put_u32(p, dentry->attributes);
1431 p = put_u32(p, dentry->security_id);
1432 p = put_u64(p, dentry->subdir_offset);
1433 p = put_u64(p, 0); /* unused1 */
1434 p = put_u64(p, 0); /* unused2 */
1435 p = put_u64(p, dentry->creation_time);
1436 p = put_u64(p, dentry->last_access_time);
1437 p = put_u64(p, dentry->last_write_time);
1438 hash = dentry_stream_hash(dentry, 0);
1439 p = put_bytes(p, SHA1_HASH_SIZE, hash);
1440 if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1441 p = put_zeroes(p, 4);
1442 p = put_u32(p, dentry->reparse_tag);
1443 p = put_zeroes(p, 4);
1447 if (dentry->link_group_list.next == &dentry->link_group_list)
1450 link_group_id = dentry->link_group_id;
1451 p = put_u64(p, link_group_id);
1453 p = put_u16(p, dentry->num_ads);
1454 p = put_u16(p, dentry->short_name_len);
1455 p = put_u16(p, dentry->file_name_len);
1456 if (dentry->file_name_len) {
1457 p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
1458 p = put_u16(p, 0); /* filename padding, 2 bytes. */
1460 if (dentry->short_name) {
1461 p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
1462 p = put_u16(p, 0); /* short name padding, 2 bytes */
1465 /* Align to 8-byte boundary */
1466 wimlib_assert(length >= (p - orig_p)
1467 && length - (p - orig_p) <= 7);
1468 p = put_zeroes(p, length - (p - orig_p));
1470 /* Write the alternate data streams, if there are any. Please see
1471 * read_ads_entries() for comments about the format of the on-disk
1472 * alternate data stream entries. */
1473 for (u16 i = 0; i < dentry->num_ads; i++) {
1474 p = put_u64(p, ads_entry_total_length(&dentry->ads_entries[i]));
1475 p = put_u64(p, 0); /* Unused */
1476 hash = dentry_stream_hash(dentry, i + 1);
1477 p = put_bytes(p, SHA1_HASH_SIZE, hash);
1478 p = put_u16(p, dentry->ads_entries[i].stream_name_len);
1479 if (dentry->ads_entries[i].stream_name_len) {
1480 p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
1481 (u8*)dentry->ads_entries[i].stream_name);
1484 p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1486 #ifdef ENABLE_ASSERTIONS
1487 wimlib_assert(p - orig_p == __dentry_total_length(dentry, length));
1492 /* Recursive function that writes a dentry tree rooted at @parent, not including
1493 * @parent itself, which has already been written. */
1494 static u8 *write_dentry_tree_recursive(const struct dentry *parent, u8 *p)
1496 const struct dentry *child;
1498 /* Nothing to do if this dentry has no children. */
1499 if (parent->subdir_offset == 0)
1502 /* Write child dentries and end-of-directory entry.
1504 * Note: we need to write all of this dentry's children before
1505 * recursively writing the directory trees rooted at each of the child
1506 * dentries, since the on-disk dentries for a dentry's children are
1507 * always located at consecutive positions in the metadata resource! */
1508 child = parent->children;
1511 p = write_dentry(child, p);
1512 child = child->next;
1513 } while (child != parent->children);
1516 /* write end of directory entry */
1519 /* Recurse on children. */
1522 p = write_dentry_tree_recursive(child, p);
1523 child = child->next;
1524 } while (child != parent->children);
1529 /* Writes a directory tree to the metadata resource.
1531 * @root: Root of the dentry tree.
1532 * @p: Pointer to a buffer with enough space for the dentry tree.
1534 * Returns pointer to the byte after the last byte we wrote.
1536 u8 *write_dentry_tree(const struct dentry *root, u8 *p)
1538 wimlib_assert(dentry_is_root(root));
1540 /* If we're the root dentry, we have no parent that already
1541 * wrote us, so we need to write ourselves. */
1542 p = write_dentry(root, p);
1544 /* Write end of directory entry after the root dentry just to be safe;
1545 * however the root dentry obviously cannot have any siblings. */
1548 /* Recursively write the rest of the dentry tree. */
1549 return write_dentry_tree_recursive(root, p);
1552 /* Reads the children of a dentry, and all their children, ..., etc. from the
1553 * metadata resource and into the dentry tree.
1555 * @metadata_resource: An array that contains the uncompressed metadata
1556 * resource for the WIM file.
1558 * @metadata_resource_len: The length of the uncompressed metadata resource, in
1561 * @dentry: A pointer to a `struct dentry' that is the root of the directory
1562 * tree and has already been read from the metadata resource. It
1563 * does not need to be the real root because this procedure is
1564 * called recursively.
1566 * @return: Zero on success, nonzero on failure.
1568 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1569 struct dentry *dentry)
1571 u64 cur_offset = dentry->subdir_offset;
1572 struct dentry *prev_child = NULL;
1573 struct dentry *first_child = NULL;
1574 struct dentry *child;
1575 struct dentry cur_child;
1579 * If @dentry has no child dentries, nothing more needs to be done for
1580 * this branch. This is the case for regular files, symbolic links, and
1581 * *possibly* empty directories (although an empty directory may also
1582 * have one child dentry that is the special end-of-directory dentry)
1584 if (cur_offset == 0)
1587 /* Find and read all the children of @dentry. */
1590 /* Read next child of @dentry into @cur_child. */
1591 ret = read_dentry(metadata_resource, metadata_resource_len,
1592 cur_offset, &cur_child);
1596 /* Check for end of directory. */
1597 if (cur_child.length == 0)
1600 /* Not end of directory. Allocate this child permanently and
1601 * link it to the parent and previous child. */
1602 child = MALLOC(sizeof(struct dentry));
1604 ERROR("Failed to allocate %zu bytes for new dentry",
1605 sizeof(struct dentry));
1606 ret = WIMLIB_ERR_NOMEM;
1609 memcpy(child, &cur_child, sizeof(struct dentry));
1612 prev_child->next = child;
1613 child->prev = prev_child;
1615 first_child = child;
1618 child->parent = dentry;
1621 /* If there are children of this child, call this procedure
1623 if (child->subdir_offset != 0) {
1624 ret = read_dentry_tree(metadata_resource,
1625 metadata_resource_len, child);
1630 /* Advance to the offset of the next child. Note: We need to
1631 * advance by the TOTAL length of the dentry, not by the length
1632 * child->length, which although it does take into account the
1633 * padding, it DOES NOT take into account alternate stream
1635 cur_offset += dentry_total_length(child);
1638 /* Link last child to first one, and set parent's children pointer to
1639 * the first child. */
1641 prev_child->next = first_child;
1642 first_child->prev = prev_child;
1644 dentry->children = first_child;