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   1 /*
   2  * dentry.c
   3  *
   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
   9  * entries.
  10  */
  11
  12 /*
  13  *
  14  * Copyright (C) 2010 Carl Thijssen
  15  * Copyright (C) 2012 Eric Biggers
  16  *
  17  * This file is part of wimlib, a library for working with WIM files.
  18  *
  19  * wimlib is free software; you can redistribute it and/or modify it under the
  20  * terms of the GNU Lesser General Public License as published by the Free
  21  * Software Foundation; either version 2.1 of the License, or (at your option)
  22  * any later version.
  23  *
  24  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  25  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  26  * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  27  * details.
  28  *
  29  * You should have received a copy of the GNU Lesser General Public License
  30  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  31  */
  32
  33 #include "wimlib_internal.h"
  34 #include "dentry.h"
  35 #include "io.h"
  36 #include "timestamp.h"
  37 #include "lookup_table.h"
  38 #include "sha1.h"
  39 #include <unistd.h>
  40 #include <sys/stat.h>
  41
  42 /*
  43  * Returns true if @dentry has the UTF-8 file name @name that has length
  44  * @name_len.
  45  */
  46 static bool dentry_has_name(const struct dentry *dentry, const char *name,
  47                             size_t name_len)
  48 {
  49         if (dentry->file_name_utf8_len != name_len)
  50                 return false;
  51         return memcmp(dentry->file_name_utf8, name, name_len) == 0;
  52 }
  53
  54 /* Real length of a dentry, including the alternate data stream entries, which
  55  * are not included in the dentry->length field... */
  56 u64 dentry_total_length(const struct dentry *dentry)
  57 {
  58         u64 length = (dentry->length + 7) & ~7;
  59         for (u16 i = 0 ; i < dentry->num_ads; i++)
  60                 length += ads_entry_length(&dentry->ads_entries[i]);
  61         return length;
  62 }
  63
  64 /* Transfers file attributes from a `stat' buffer to a struct dentry. */
  65 void stbuf_to_dentry(const struct stat *stbuf, struct dentry *dentry)
  66 {
  67         if (S_ISLNK(stbuf->st_mode)) {
  68                 dentry->attributes = FILE_ATTRIBUTE_REPARSE_POINT;
  69                 dentry->reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
  70         } else if (S_ISDIR(stbuf->st_mode)) {
  71                 dentry->attributes = FILE_ATTRIBUTE_DIRECTORY;
  72         } else {
  73                 dentry->attributes = FILE_ATTRIBUTE_NORMAL;
  74         }
  75         if (sizeof(ino_t) >= 8)
  76                 dentry->hard_link = (u64)stbuf->st_ino;
  77         else
  78                 dentry->hard_link = (u64)stbuf->st_ino |
  79                                    ((u64)stbuf->st_dev << (sizeof(ino_t) * 8));
  80 }
  81
  82 /* Transfers file attributes from a struct dentry to a `stat' buffer. */
  83 int dentry_to_stbuf(const struct dentry *dentry, struct stat *stbuf,
  84                     const struct lookup_table *table)
  85 {
  86         struct lookup_table_entry *lte;
  87
  88         if (dentry_is_symlink(dentry))
  89                 stbuf->st_mode = S_IFLNK | 0777;
  90         else if (dentry_is_directory(dentry))
  91                 stbuf->st_mode = S_IFDIR | 0755;
  92         else
  93                 stbuf->st_mode = S_IFREG | 0644;
  94
  95         stbuf->st_ino = (ino_t)dentry->hard_link;
  96
  97         stbuf->st_nlink = dentry_link_group_size(dentry);
  98         stbuf->st_uid   = getuid();
  99         stbuf->st_gid   = getgid();
 100
 101         /* Use the size of the unnamed (default) file stream. */
 102         if (table && (lte = __lookup_resource(table, dentry_hash(dentry)))) {
 103                 if (lte->staging_file_name) {
 104                         struct stat native_stat;
 105                         if (stat(lte->staging_file_name, &native_stat) != 0)
 106                                 return -errno;
 107                         stbuf->st_size = native_stat.st_size;
 108                 } else {
 109                         stbuf->st_size = lte->resource_entry.original_size;
 110                 }
 111         } else {
 112                 stbuf->st_size = 0;
 113         }
 114
 115         stbuf->st_atime   = ms_timestamp_to_unix(dentry->last_access_time);
 116         stbuf->st_mtime   = ms_timestamp_to_unix(dentry->last_write_time);
 117         stbuf->st_ctime   = ms_timestamp_to_unix(dentry->creation_time);
 118         stbuf->st_blocks  = (stbuf->st_size + 511) / 512;
 119         return 0;
 120 }
 121
 122 /* Makes all timestamp fields for the dentry be the current time. */
 123 void dentry_update_all_timestamps(struct dentry *dentry)
 124 {
 125         u64 now = get_timestamp();
 126         dentry->creation_time    = now;
 127         dentry->last_access_time = now;
 128         dentry->last_write_time  = now;
 129 }
 130
 131 struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
 132                                        const char *stream_name)
 133 {
 134         size_t stream_name_len = strlen(stream_name);
 135         if (!stream_name)
 136                 return NULL;
 137         for (u16 i = 0; i < dentry->num_ads; i++)
 138                 if (ads_entry_has_name(&dentry->ads_entries[i],
 139                                        stream_name, stream_name_len))
 140                         return &dentry->ads_entries[i];
 141         return NULL;
 142 }
 143
 144 /* Add an alternate stream entry to a dentry and return a pointer to it, or NULL
 145  * on failure. */
 146 struct ads_entry *dentry_add_ads(struct dentry *dentry, const char *stream_name)
 147 {
 148         u16 num_ads = dentry->num_ads + 1;
 149         struct ads_entry *ads_entries;
 150         struct ads_entry *new_entry;
 151         if (num_ads == 0xffff)
 152                 return NULL;
 153         ads_entries = MALLOC(num_ads * sizeof(struct ads_entry));
 154         if (!ads_entries)
 155                 return NULL;
 156
 157         new_entry = &ads_entries[num_ads - 1];
 158         if (change_ads_name(new_entry, stream_name) != 0) {
 159                 FREE(ads_entries);
 160                 return NULL;
 161         }
 162
 163         memcpy(ads_entries, dentry->ads_entries,
 164                (num_ads - 1) * sizeof(struct ads_entry));
 165         FREE(dentry->ads_entries);
 166         dentry->ads_entries = ads_entries;
 167         dentry->num_ads = num_ads;
 168         return memset(new_entry, 0, sizeof(struct ads_entry));
 169 }
 170
 171 void dentry_remove_ads(struct dentry *dentry, struct ads_entry *sentry)
 172 {
 173         destroy_ads_entry(sentry);
 174         memcpy(sentry, sentry + 1,
 175                (dentry->num_ads - (sentry - dentry->ads_entries + 1))
 176                  * sizeof(struct ads_entry));
 177         dentry->num_ads--;
 178 }
 179
 180 /*
 181  * Calls a function on all directory entries in a directory tree.  It is called
 182  * on a parent before its children.
 183  */
 184 int for_dentry_in_tree(struct dentry *root,
 185                        int (*visitor)(struct dentry*, void*), void *arg)
 186 {
 187         int ret;
 188         struct dentry *child;
 189
 190         ret = visitor(root, arg);
 191
 192         if (ret != 0)
 193                 return ret;
 194
 195         child = root->children;
 196
 197         if (!child)
 198                 return 0;
 199
 200         do {
 201                 ret = for_dentry_in_tree(child, visitor, arg);
 202                 if (ret != 0)
 203                         return ret;
 204                 child = child->next;
 205         } while (child != root->children);
 206         return 0;
 207 }
 208
 209 /*
 210  * Like for_dentry_in_tree(), but the visitor function is always called on a
 211  * dentry's children before on itself.
 212  */
 213 int for_dentry_in_tree_depth(struct dentry *root,
 214                              int (*visitor)(struct dentry*, void*), void *arg)
 215 {
 216         int ret;
 217         struct dentry *child;
 218         struct dentry *next;
 219
 220         child = root->children;
 221         if (child) {
 222                 do {
 223                         next = child->next;
 224                         ret = for_dentry_in_tree_depth(child, visitor, arg);
 225                         if (ret != 0)
 226                                 return ret;
 227                         child = next;
 228                 } while (child != root->children);
 229         }
 230         return visitor(root, arg);
 231 }
 232
 233 /*
 234  * Calculate the full path of @dentry, based on its parent's full path and on
 235  * its UTF-8 file name.
 236  */
 237 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
 238 {
 239         char *full_path;
 240         u32 full_path_len;
 241         if (dentry_is_root(dentry)) {
 242                 full_path = MALLOC(2);
 243                 if (!full_path)
 244                         goto oom;
 245                 full_path[0] = '/';
 246                 full_path[1] = '\0';
 247                 full_path_len = 1;
 248         } else {
 249                 char *parent_full_path;
 250                 u32 parent_full_path_len;
 251                 const struct dentry *parent = dentry->parent;
 252
 253                 if (dentry_is_root(parent)) {
 254                         parent_full_path = "";
 255                         parent_full_path_len = 0;
 256                 } else {
 257                         parent_full_path = parent->full_path_utf8;
 258                         parent_full_path_len = parent->full_path_utf8_len;
 259                 }
 260
 261                 full_path_len = parent_full_path_len + 1 +
 262                                 dentry->file_name_utf8_len;
 263                 full_path = MALLOC(full_path_len + 1);
 264                 if (!full_path)
 265                         goto oom;
 266
 267                 memcpy(full_path, parent_full_path, parent_full_path_len);
 268                 full_path[parent_full_path_len] = '/';
 269                 memcpy(full_path + parent_full_path_len + 1,
 270                        dentry->file_name_utf8,
 271                        dentry->file_name_utf8_len);
 272                 full_path[full_path_len] = '\0';
 273         }
 274         FREE(dentry->full_path_utf8);
 275         dentry->full_path_utf8 = full_path;
 276         dentry->full_path_utf8_len = full_path_len;
 277         return 0;
 278 oom:
 279         ERROR("Out of memory while calculating dentry full path");
 280         return WIMLIB_ERR_NOMEM;
 281 }
 282
 283 /*
 284  * Recursively calculates the subdir offsets for a directory tree.
 285  *
 286  * @dentry:  The root of the directory tree.
 287  * @subdir_offset_p:  The current subdirectory offset; i.e., the subdirectory
 288  *      offset for @dentry.
 289  */
 290 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 291 {
 292         struct dentry *child;
 293
 294         child = dentry->children;
 295         dentry->subdir_offset = *subdir_offset_p;
 296         if (child) {
 297
 298                 /* Advance the subdir offset by the amount of space the children
 299                  * of this dentry take up. */
 300                 do {
 301                         *subdir_offset_p += dentry_total_length(child);
 302                         child = child->next;
 303                 } while (child != dentry->children);
 304
 305                 /* End-of-directory dentry on disk. */
 306                 *subdir_offset_p += 8;
 307
 308                 /* Recursively call calculate_subdir_offsets() on all the
 309                  * children. */
 310                 do {
 311                         calculate_subdir_offsets(child, subdir_offset_p);
 312                         child = child->next;
 313                 } while (child != dentry->children);
 314         } else {
 315                 /* On disk, childless directories have a valid subdir_offset
 316                  * that points to an 8-byte end-of-directory dentry.  Regular
 317                  * files have a subdir_offset of 0. */
 318                 if (dentry_is_directory(dentry))
 319                         *subdir_offset_p += 8;
 320                 else
 321                         dentry->subdir_offset = 0;
 322         }
 323 }
 324
 325
 326 /* Returns the child of @dentry that has the file name @name.
 327  * Returns NULL if no child has the name. */
 328 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
 329                                                         const char *name)
 330 {
 331         struct dentry *child;
 332         size_t name_len;
 333
 334         child = dentry->children;
 335         if (child) {
 336                 name_len = strlen(name);
 337                 do {
 338                         if (dentry_has_name(child, name, name_len))
 339                                 return child;
 340                         child = child->next;
 341                 } while (child != dentry->children);
 342         }
 343         return NULL;
 344 }
 345
 346 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
 347  * @cur_dir.  Returns NULL if no dentry having the path is found. */
 348 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir, const char *path)
 349 {
 350         struct dentry *child;
 351         size_t base_len;
 352         const char *new_path;
 353
 354         if (*path == '\0')
 355                 return cur_dir;
 356
 357         child = cur_dir->children;
 358         if (child) {
 359                 new_path = path_next_part(path, &base_len);
 360                 do {
 361                         if (dentry_has_name(child, path, base_len))
 362                                 return get_dentry_relative_path(child, new_path);
 363                         child = child->next;
 364                 } while (child != cur_dir->children);
 365         }
 366         return NULL;
 367 }
 368
 369 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
 370  * such dentry. */
 371 struct dentry *get_dentry(WIMStruct *w, const char *path)
 372 {
 373         struct dentry *root = wim_root_dentry(w);
 374         while (*path == '/')
 375                 path++;
 376         return get_dentry_relative_path(root, path);
 377 }
 378
 379 /* Returns the parent directory for the @path. */
 380 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
 381 {
 382         size_t path_len = strlen(path);
 383         char buf[path_len + 1];
 384
 385         memcpy(buf, path, path_len + 1);
 386
 387         to_parent_name(buf, path_len);
 388
 389         return get_dentry(w, buf);
 390 }
 391
 392 /* Prints the full path of a dentry. */
 393 int print_dentry_full_path(struct dentry *dentry, void *ignore)
 394 {
 395         if (dentry->full_path_utf8)
 396                 puts(dentry->full_path_utf8);
 397         return 0;
 398 }
 399
 400 struct file_attr_flag {
 401         u32 flag;
 402         const char *name;
 403 };
 404 struct file_attr_flag file_attr_flags[] = {
 405         {FILE_ATTRIBUTE_READONLY,               "READONLY"},
 406         {FILE_ATTRIBUTE_HIDDEN,         "HIDDEN"},
 407         {FILE_ATTRIBUTE_SYSTEM,         "SYSTEM"},
 408         {FILE_ATTRIBUTE_DIRECTORY,              "DIRECTORY"},
 409         {FILE_ATTRIBUTE_ARCHIVE,                "ARCHIVE"},
 410         {FILE_ATTRIBUTE_DEVICE,         "DEVICE"},
 411         {FILE_ATTRIBUTE_NORMAL,         "NORMAL"},
 412         {FILE_ATTRIBUTE_TEMPORARY,              "TEMPORARY"},
 413         {FILE_ATTRIBUTE_SPARSE_FILE,    "SPARSE_FILE"},
 414         {FILE_ATTRIBUTE_REPARSE_POINT,  "REPARSE_POINT"},
 415         {FILE_ATTRIBUTE_COMPRESSED,             "COMPRESSED"},
 416         {FILE_ATTRIBUTE_OFFLINE,                "OFFLINE"},
 417         {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
 418         {FILE_ATTRIBUTE_ENCRYPTED,              "ENCRYPTED"},
 419         {FILE_ATTRIBUTE_VIRTUAL,                "VIRTUAL"},
 420 };
 421
 422 /* Prints a directory entry.  @lookup_table is a pointer to the lookup table, or
 423  * NULL if the resource entry for the dentry is not to be printed. */
 424 int print_dentry(struct dentry *dentry, void *lookup_table)
 425 {
 426         struct lookup_table_entry *lte;
 427         unsigned i;
 428
 429         printf("[DENTRY]\n");
 430         printf("Length            = %"PRIu64"\n", dentry->length);
 431         printf("Attributes        = 0x%x\n", dentry->attributes);
 432         for (i = 0; i < ARRAY_LEN(file_attr_flags); i++)
 433                 if (file_attr_flags[i].flag & dentry->attributes)
 434                         printf("    FILE_ATTRIBUTE_%s is set\n",
 435                                 file_attr_flags[i].name);
 436         printf("Security ID       = %d\n", dentry->security_id);
 437         printf("Subdir offset     = %"PRIu64"\n", dentry->subdir_offset);
 438         /*printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);*/
 439         /*printf("Unused2           = %"PRIu64"\n", dentry->unused2);*/
 440         printf("Creation Time     = 0x%"PRIx64"\n", dentry->creation_time);
 441         printf("Last Access Time  = 0x%"PRIx64"\n", dentry->last_access_time);
 442         printf("Last Write Time   = 0x%"PRIx64"\n", dentry->last_write_time);
 443         printf("Hash              = 0x");
 444         print_hash(dentry->hash);
 445         putchar('\n');
 446         printf("Reparse Tag       = 0x%"PRIx32"\n", dentry->reparse_tag);
 447         printf("Hard Link Group   = 0x%"PRIx64"\n", dentry->hard_link);
 448         printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
 449         printf("Filename          = \"");
 450         print_string(dentry->file_name, dentry->file_name_len);
 451         puts("\"");
 452         printf("Filename Length   = %hu\n", dentry->file_name_len);
 453         printf("Filename (UTF-8)  = \"%s\"\n", dentry->file_name_utf8);
 454         printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
 455         printf("Short Name        = \"");
 456         print_string(dentry->short_name, dentry->short_name_len);
 457         puts("\"");
 458         printf("Short Name Length = %hu\n", dentry->short_name_len);
 459         printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
 460         if (lookup_table && (lte = __lookup_resource(lookup_table, dentry->hash)))
 461                 print_lookup_table_entry(lte, NULL);
 462         else
 463                 putchar('\n');
 464         for (u16 i = 0; i < dentry->num_ads; i++) {
 465                 printf("[Alternate Stream Entry %u]\n", i);
 466                 printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
 467                 printf("Name Length (UTF-16) = %u\n",
 468                                 dentry->ads_entries[i].stream_name_len);
 469                 printf("Hash              = 0x");
 470                 print_hash(dentry->ads_entries[i].hash);
 471                 if (lookup_table &&
 472                      (lte = __lookup_resource(lookup_table,
 473                                               dentry->ads_entries[i].hash)))
 474                 {
 475                         print_lookup_table_entry(lte, NULL);
 476                 } else {
 477                         putchar('\n');
 478                 }
 479         }
 480         return 0;
 481 }
 482
 483 static inline void dentry_common_init(struct dentry *dentry)
 484 {
 485         memset(dentry, 0, sizeof(struct dentry));
 486         dentry->refcnt = 1;
 487         dentry->security_id = -1;
 488         dentry->link_group_master_status = GROUP_SLAVE;
 489 }
 490
 491 /*
 492  * Creates an unlinked directory entry.
 493  *
 494  * @name:    The base name of the new dentry.
 495  * @return:  A pointer to the new dentry, or NULL if out of memory.
 496  */
 497 struct dentry *new_dentry(const char *name)
 498 {
 499         struct dentry *dentry;
 500
 501         dentry = MALLOC(sizeof(struct dentry));
 502         if (!dentry)
 503                 goto err;
 504
 505         dentry_common_init(dentry);
 506         if (change_dentry_name(dentry, name) != 0)
 507                 goto err;
 508
 509         dentry_update_all_timestamps(dentry);
 510         dentry->next   = dentry;
 511         dentry->prev   = dentry;
 512         dentry->parent = dentry;
 513         INIT_LIST_HEAD(&dentry->link_group_list);
 514         return dentry;
 515 err:
 516         FREE(dentry);
 517         ERROR("Failed to allocate new dentry");
 518         return NULL;
 519 }
 520
 521 void dentry_free_ads_entries(struct dentry *dentry)
 522 {
 523         for (u16 i = 0; i < dentry->num_ads; i++)
 524                 destroy_ads_entry(&dentry->ads_entries[i]);
 525         FREE(dentry->ads_entries);
 526         dentry->ads_entries = NULL;
 527         dentry->num_ads = 0;
 528 }
 529
 530 static void __destroy_dentry(struct dentry *dentry)
 531 {
 532         FREE(dentry->file_name);
 533         FREE(dentry->file_name_utf8);
 534         FREE(dentry->short_name);
 535         FREE(dentry->full_path_utf8);
 536         FREE(dentry->extracted_file);
 537 }
 538
 539 void free_dentry(struct dentry *dentry)
 540 {
 541         __destroy_dentry(dentry);
 542         if (dentry->link_group_master_status != GROUP_SLAVE)
 543                 dentry_free_ads_entries(dentry);
 544         FREE(dentry);
 545 }
 546
 547 void put_dentry(struct dentry *dentry)
 548 {
 549         if (dentry->link_group_master_status == GROUP_MASTER) {
 550                 struct dentry *new_master;
 551                 list_for_each_entry(new_master, &dentry->link_group_list,
 552                                     link_group_list)
 553                 {
 554                         if (new_master->link_group_master_status == GROUP_SLAVE) {
 555                                 new_master->link_group_master_status = GROUP_MASTER;
 556                                 dentry->link_group_master_status = GROUP_SLAVE;
 557                                 break;
 558                         }
 559                 }
 560         }
 561         struct list_head *next;
 562         next = dentry->link_group_list.next;
 563         list_del(&dentry->link_group_list);
 564         /*if (next->next == next)*/
 565                 /*container_of(next, struct dentry, link_group_list)->hard_link = 0;*/
 566         free_dentry(dentry);
 567 }
 568
 569 static bool dentries_have_same_ads(const struct dentry *d1,
 570                                    const struct dentry *d2)
 571 {
 572         /* Verify stream names and hashes are the same */
 573         for (u16 i = 0; i < d1->num_ads; i++) {
 574                 if (strcmp(d1->ads_entries[i].stream_name_utf8,
 575                            d2->ads_entries[i].stream_name_utf8) != 0)
 576                         return false;
 577                 if (memcmp(d1->ads_entries[i].hash,
 578                            d2->ads_entries[i].hash,
 579                            WIM_HASH_SIZE) != 0)
 580                         return false;
 581         }
 582         return true;
 583 }
 584
 585 /* Share the alternate stream entries between hard-linked dentries. */
 586 int share_dentry_ads(struct dentry *master, struct dentry *slave)
 587 {
 588         const char *mismatch_type;
 589         wimlib_assert(master->num_ads == 0 ||
 590                       master->ads_entries != slave->ads_entries);
 591         if (master->attributes != slave->attributes) {
 592                 mismatch_type = "attributes";
 593                 goto mismatch;
 594         }
 595         if (master->attributes & FILE_ATTRIBUTE_DIRECTORY) {
 596                 WARNING("`%s' is hard-linked to `%s', which is a directory ",
 597                         slave->full_path_utf8, master->full_path_utf8);
 598                 return WIMLIB_ERR_INVALID_DENTRY;
 599         }
 600         if (master->security_id != slave->security_id) {
 601                 mismatch_type = "security ID";
 602                 goto mismatch;
 603         }
 604         if (memcmp(master->hash, slave->hash, WIM_HASH_SIZE) != 0) {
 605                 mismatch_type = "main file resource";
 606                 goto mismatch;
 607         }
 608         if (!dentries_have_same_ads(master, slave)) {
 609                 mismatch_type = "Alternate Stream Entries";
 610                 goto mismatch;
 611         }
 612         dentry_free_ads_entries(slave);
 613         slave->ads_entries = master->ads_entries;
 614         slave->link_group_master_status = GROUP_SLAVE;
 615         return 0;
 616 mismatch:
 617         WARNING("Dentries `%s' and `%s' in the same hard-link group but "
 618                 "do not share the same %s",
 619                 master->full_path_utf8, slave->full_path_utf8,
 620                 mismatch_type);
 621         return WIMLIB_ERR_INVALID_DENTRY;
 622 }
 623
 624 /* clones a dentry.
 625  *
 626  * Beware:
 627  *      - memory for file names is not cloned
 628  *      - next, prev, and children pointers and not touched
 629  *      - stream entries are not cloned.
 630  */
 631 struct dentry *clone_dentry(struct dentry *old)
 632 {
 633         struct dentry *new = MALLOC(sizeof(struct dentry));
 634         if (!new)
 635                 return NULL;
 636         memcpy(new, old, sizeof(struct dentry));
 637         new->file_name          = NULL;
 638         new->file_name_len      = 0;
 639         new->file_name_utf8     = NULL;
 640         new->file_name_utf8_len = 0;
 641         new->short_name         = NULL;
 642         new->short_name_len     = 0;
 643         return new;
 644 }
 645
 646 /* Arguments for do_free_dentry(). */
 647 struct free_dentry_args {
 648         struct lookup_table *lookup_table;
 649         bool lt_decrement_refcnt;
 650 };
 651
 652 /*
 653  * This function is passed as an argument to for_dentry_in_tree_depth() in order
 654  * to free a directory tree.  __args is a pointer to a `struct free_dentry_args'.
 655  */
 656 static int do_free_dentry(struct dentry *dentry, void *__args)
 657 {
 658         struct free_dentry_args *args = (struct free_dentry_args*)__args;
 659
 660         if (args->lt_decrement_refcnt && !dentry_is_directory(dentry)) {
 661                 lookup_table_decrement_refcnt(args->lookup_table,
 662                                               dentry->hash);
 663         }
 664
 665         wimlib_assert(dentry->refcnt >= 1);
 666         if (--dentry->refcnt == 0)
 667                 free_dentry(dentry);
 668         return 0;
 669 }
 670
 671 /*
 672  * Unlinks and frees a dentry tree.
 673  *
 674  * @root:               The root of the tree.
 675  * @lookup_table:       The lookup table for dentries.
 676  * @decrement_refcnt:   True if the dentries in the tree are to have their
 677  *                      reference counts in the lookup table decremented.
 678  */
 679 void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table,
 680                       bool lt_decrement_refcnt)
 681 {
 682         if (!root || !root->parent)
 683                 return;
 684
 685         struct free_dentry_args args;
 686         args.lookup_table        = lookup_table;
 687         args.lt_decrement_refcnt = lt_decrement_refcnt;
 688         for_dentry_in_tree_depth(root, do_free_dentry, &args);
 689 }
 690
 691 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
 692 {
 693         dentry->refcnt++;
 694         return 0;
 695 }
 696
 697 /*
 698  * Links a dentry into the directory tree.
 699  *
 700  * @dentry: The dentry to link.
 701  * @parent: The dentry that will be the parent of @dentry.
 702  */
 703 void link_dentry(struct dentry *dentry, struct dentry *parent)
 704 {
 705         dentry->parent = parent;
 706         if (parent->children) {
 707                 /* Not an only child; link to siblings. */
 708                 dentry->next = parent->children;
 709                 dentry->prev = parent->children->prev;
 710                 dentry->next->prev = dentry;
 711                 dentry->prev->next = dentry;
 712         } else {
 713                 /* Only child; link to parent. */
 714                 parent->children = dentry;
 715                 dentry->next = dentry;
 716                 dentry->prev = dentry;
 717         }
 718 }
 719
 720
 721 /* Unlink a dentry from the directory tree.
 722  *
 723  * Note: This merely removes it from the in-memory tree structure.  See
 724  * remove_dentry() in mount.c for a function implemented on top of this one that
 725  * frees the dentry and implements reference counting for the lookup table
 726  * entries. */
 727 void unlink_dentry(struct dentry *dentry)
 728 {
 729         if (dentry_is_root(dentry))
 730                 return;
 731         if (dentry_is_only_child(dentry)) {
 732                 dentry->parent->children = NULL;
 733         } else {
 734                 if (dentry_is_first_sibling(dentry))
 735                         dentry->parent->children = dentry->next;
 736                 dentry->next->prev = dentry->prev;
 737                 dentry->prev->next = dentry->next;
 738         }
 739 }
 740
 741
 742 /* Recalculates the length of @dentry based on its file name length and short
 743  * name length.  */
 744 static inline void recalculate_dentry_size(struct dentry *dentry)
 745 {
 746         dentry->length = WIM_DENTRY_DISK_SIZE + dentry->file_name_len +
 747                          2 + dentry->short_name_len;
 748         /* Must be multiple of 8. */
 749         dentry->length = (dentry->length + 7) & ~7;
 750 }
 751
 752 int get_names(char **name_utf16_ret, char **name_utf8_ret,
 753               u16 *name_utf16_len_ret, u16 *name_utf8_len_ret,
 754               const char *name)
 755 {
 756         size_t utf8_len;
 757         size_t utf16_len;
 758         char *name_utf16, *name_utf8;
 759
 760         utf8_len = strlen(name);
 761
 762         name_utf16 = utf8_to_utf16(name, utf8_len, &utf16_len);
 763
 764         if (!name_utf16)
 765                 return WIMLIB_ERR_NOMEM;
 766
 767         name_utf8 = MALLOC(utf8_len + 1);
 768         if (!name_utf8) {
 769                 FREE(name_utf8);
 770                 return WIMLIB_ERR_NOMEM;
 771         }
 772         memcpy(name_utf8, name, utf8_len + 1);
 773         FREE(*name_utf8_ret);
 774         FREE(*name_utf16_ret);
 775         *name_utf8_ret      = name_utf8;
 776         *name_utf16_ret     = name_utf16;
 777         *name_utf8_len_ret  = utf8_len;
 778         *name_utf16_len_ret = utf16_len;
 779         return 0;
 780 }
 781
 782 /* Changes the name of a dentry to @new_name.  Only changes the file_name and
 783  * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
 784  * full_path_utf8 fields.  Also recalculates its length. */
 785 int change_dentry_name(struct dentry *dentry, const char *new_name)
 786 {
 787         int ret;
 788
 789         ret = get_names(&dentry->file_name, &dentry->file_name_utf8,
 790                         &dentry->file_name_len, &dentry->file_name_utf8_len,
 791                          new_name);
 792         if (ret == 0)
 793                 recalculate_dentry_size(dentry);
 794         return ret;
 795 }
 796
 797 int change_ads_name(struct ads_entry *entry, const char *new_name)
 798 {
 799         return get_names(&entry->stream_name, &entry->stream_name_utf8,
 800                          &entry->stream_name_len,
 801                          &entry->stream_name_utf8_len,
 802                           new_name);
 803 }
 804
 805 /* Parameters for calculate_dentry_statistics(). */
 806 struct image_statistics {
 807         struct lookup_table *lookup_table;
 808         u64 *dir_count;
 809         u64 *file_count;
 810         u64 *total_bytes;
 811         u64 *hard_link_bytes;
 812 };
 813
 814 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
 815 {
 816         struct image_statistics *stats;
 817         struct lookup_table_entry *lte;
 818         u16 i;
 819
 820         stats = arg;
 821
 822         if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
 823                 ++*stats->dir_count;
 824         else
 825                 ++*stats->file_count;
 826
 827         lte = __lookup_resource(stats->lookup_table, dentry->hash);
 828         i = 0;
 829         while (1) {
 830                 if (lte) {
 831                         u64 size = lte->resource_entry.original_size;
 832                         *stats->total_bytes += size;
 833                         if (++lte->out_refcnt == 1)
 834                                 *stats->hard_link_bytes += size;
 835                 }
 836                 if (i == dentry->num_ads)
 837                         break;
 838                 lte = __lookup_resource(stats->lookup_table,
 839                                         dentry->ads_entries[i].hash);
 840                 i++;
 841         }
 842
 843         return 0;
 844 }
 845
 846 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
 847                                    u64 *dir_count_ret, u64 *file_count_ret,
 848                                    u64 *total_bytes_ret,
 849                                    u64 *hard_link_bytes_ret)
 850 {
 851         struct image_statistics stats;
 852         *dir_count_ret         = 0;
 853         *file_count_ret        = 0;
 854         *total_bytes_ret       = 0;
 855         *hard_link_bytes_ret   = 0;
 856         stats.lookup_table     = table;
 857         stats.dir_count       = dir_count_ret;
 858         stats.file_count      = file_count_ret;
 859         stats.total_bytes     = total_bytes_ret;
 860         stats.hard_link_bytes = hard_link_bytes_ret;
 861         for_lookup_table_entry(table, zero_out_refcnts, NULL);
 862         for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
 863 }
 864
 865 static int read_ads_entries(const u8 *p, struct dentry *dentry,
 866                             u64 remaining_size)
 867 {
 868         u16 num_ads = dentry->num_ads;
 869         struct ads_entry *ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
 870         int ret;
 871         if (!ads_entries) {
 872                 ERROR("Could not allocate memory for %"PRIu16" "
 873                       "alternate data stream entries", num_ads);
 874                 return WIMLIB_ERR_NOMEM;
 875         }
 876         DEBUG2("Reading %"PRIu16" alternate data streams "
 877                "(remaining size = %"PRIu64")", num_ads, remaining_size);
 878
 879         for (u16 i = 0; i < num_ads; i++) {
 880                 struct ads_entry *cur_entry = &ads_entries[i];
 881                 u64 length;
 882                 size_t utf8_len;
 883                 const char *p_save = p;
 884                 /* Read the base stream entry, excluding the stream name. */
 885                 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
 886                         ERROR("Stream entries go past end of metadata resource");
 887                         ERROR("(remaining_size = %"PRIu64")", remaining_size);
 888                         ret = WIMLIB_ERR_INVALID_DENTRY;
 889                         goto out_free_ads_entries;
 890                 }
 891                 remaining_size -= WIM_ADS_ENTRY_DISK_SIZE;
 892
 893                 p = get_u64(p, &length); /* ADS entry length */
 894
 895                 DEBUG2("ADS length = %"PRIu64, length);
 896
 897                 p += 8; /* Unused */
 898                 p = get_bytes(p, WIM_HASH_SIZE, (u8*)cur_entry->hash);
 899                 p = get_u16(p, &cur_entry->stream_name_len);
 900
 901                 DEBUG2("Stream name length = %u", cur_entry->stream_name_len);
 902
 903                 cur_entry->stream_name = NULL;
 904                 cur_entry->stream_name_utf8 = NULL;
 905
 906                 if (remaining_size < cur_entry->stream_name_len + 2) {
 907                         ERROR("Stream entries go past end of metadata resource");
 908                         ERROR("(remaining_size = %"PRIu64" bytes, stream_name_len "
 909                               "= %"PRIu16" bytes", remaining_size,
 910                               cur_entry->stream_name_len);
 911                         ret = WIMLIB_ERR_INVALID_DENTRY;
 912                         goto out_free_ads_entries;
 913                 }
 914                 remaining_size -= cur_entry->stream_name_len + 2;
 915
 916                 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
 917                 if (!cur_entry->stream_name) {
 918                         ret = WIMLIB_ERR_NOMEM;
 919                         goto out_free_ads_entries;
 920                 }
 921                 get_bytes(p, cur_entry->stream_name_len,
 922                           (u8*)cur_entry->stream_name);
 923                 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
 924                                                             cur_entry->stream_name_len,
 925                                                             &utf8_len);
 926                 cur_entry->stream_name_utf8_len = utf8_len;
 927
 928                 if (!cur_entry->stream_name_utf8) {
 929                         ret = WIMLIB_ERR_NOMEM;
 930                         goto out_free_ads_entries;
 931                 }
 932                 p = p_save + ads_entry_length(cur_entry);
 933         }
 934         dentry->ads_entries = ads_entries;
 935         return 0;
 936 out_free_ads_entries:
 937         for (u16 i = 0; i < num_ads; i++) {
 938                 FREE(ads_entries[i].stream_name);
 939                 FREE(ads_entries[i].stream_name_utf8);
 940         }
 941         FREE(ads_entries);
 942         return ret;
 943 }
 944
 945 /*
 946  * Reads a directory entry from the metadata resource.
 947  */
 948 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
 949                 u64 offset, struct dentry *dentry)
 950 {
 951         const u8 *p;
 952         u64 calculated_size;
 953         char *file_name;
 954         char *file_name_utf8;
 955         char *short_name;
 956         u16 short_name_len;
 957         u16 file_name_len;
 958         size_t file_name_utf8_len;
 959         int ret;
 960
 961         dentry_common_init(dentry);
 962
 963         /*Make sure the dentry really fits into the metadata resource.*/
 964         if (offset + 8 > metadata_resource_len) {
 965                 ERROR("Directory entry starting at %"PRIu64" ends past the "
 966                       "end of the metadata resource (size %"PRIu64")",
 967                       offset, metadata_resource_len);
 968                 return WIMLIB_ERR_INVALID_DENTRY;
 969         }
 970
 971         /* Before reading the whole entry, we need to read just the length.
 972          * This is because an entry of length 8 (that is, just the length field)
 973          * terminates the list of sibling directory entries. */
 974
 975         p = get_u64(&metadata_resource[offset], &dentry->length);
 976
 977         /* A zero length field (really a length of 8, since that's how big the
 978          * directory entry is...) indicates that this is the end of directory
 979          * dentry.  We do not read it into memory as an actual dentry, so just
 980          * return true in that case. */
 981         if (dentry->length == 0)
 982                 return 0;
 983
 984         if (offset + dentry->length >= metadata_resource_len) {
 985                 ERROR("Directory entry at offset %"PRIu64" and with size "
 986                       "%"PRIu64" ends past the end of the metadata resource "
 987                       "(size %"PRIu64")",
 988                       offset, dentry->length, metadata_resource_len);
 989                 return WIMLIB_ERR_INVALID_DENTRY;
 990         }
 991
 992         /* If it is a recognized length, read the rest of the directory entry.
 993          * Note: The root directory entry has no name, and its length does not
 994          * include the short name length field.  */
 995         if (dentry->length < WIM_DENTRY_DISK_SIZE) {
 996                 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
 997                       dentry->length);
 998                 return WIMLIB_ERR_INVALID_DENTRY;
 999         }
1000
1001         p = get_u32(p, &dentry->attributes);
1002         p = get_u32(p, (u32*)&dentry->security_id);
1003         p = get_u64(p, &dentry->subdir_offset);
1004
1005         /* 2 unused fields */
1006         p += 2 * sizeof(u64);
1007         /*p = get_u64(p, &dentry->unused1);*/
1008         /*p = get_u64(p, &dentry->unused2);*/
1009
1010         p = get_u64(p, &dentry->creation_time);
1011         p = get_u64(p, &dentry->last_access_time);
1012         p = get_u64(p, &dentry->last_write_time);
1013
1014         p = get_bytes(p, WIM_HASH_SIZE, dentry->hash);
1015
1016         /*
1017          * I don't know what's going on here.  It seems like M$ screwed up the
1018          * reparse points, then put the fields in the same place and didn't
1019          * document it.  The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
1020          * have something to do with this, but it's not documented.
1021          */
1022         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1023                 /* ??? */
1024                 p += 4;
1025                 p = get_u32(p, &dentry->reparse_tag);
1026                 p += 4;
1027         } else {
1028                 p = get_u32(p, &dentry->reparse_tag);
1029                 p = get_u64(p, &dentry->hard_link);
1030         }
1031
1032         /* By the way, the reparse_reserved field does not actually exist (at
1033          * least when the file is not a reparse point) */
1034
1035
1036         p = get_u16(p, &dentry->num_ads);
1037
1038         p = get_u16(p, &short_name_len);
1039         p = get_u16(p, &file_name_len);
1040
1041         calculated_size = WIM_DENTRY_DISK_SIZE + file_name_len + 2 +
1042                           short_name_len;
1043
1044         if (dentry->length < calculated_size) {
1045                 ERROR("Unexpected end of directory entry! (Expected "
1046                       "%"PRIu64" bytes, got %"PRIu64" bytes. "
1047                       "short_name_len = %hu, file_name_len = %hu)",
1048                       calculated_size, dentry->length,
1049                       short_name_len, file_name_len);
1050                 return WIMLIB_ERR_INVALID_DENTRY;
1051         }
1052
1053         /* Read the filename. */
1054         file_name = MALLOC(file_name_len);
1055         if (!file_name) {
1056                 ERROR("Failed to allocate %hu bytes for dentry file name",
1057                       file_name_len);
1058                 return WIMLIB_ERR_NOMEM;
1059         }
1060         p = get_bytes(p, file_name_len, file_name);
1061
1062         /* Convert filename to UTF-8. */
1063         file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
1064                                        &file_name_utf8_len);
1065
1066         if (!file_name_utf8) {
1067                 ERROR("Failed to allocate memory to convert UTF-16 "
1068                       "filename (%hu bytes) to UTF-8", file_name_len);
1069                 ret = WIMLIB_ERR_NOMEM;
1070                 goto out_free_file_name;
1071         }
1072
1073         /* Undocumented padding between file name and short name.  This probably
1074          * is supposed to be a terminating null character. */
1075         p += 2;
1076
1077         /* Read the short filename. */
1078         short_name = MALLOC(short_name_len);
1079         if (!short_name) {
1080                 ERROR("Failed to allocate %hu bytes for short filename",
1081                       short_name_len);
1082                 ret = WIMLIB_ERR_NOMEM;
1083                 goto out_free_file_name_utf8;
1084         }
1085
1086         p = get_bytes(p, short_name_len, short_name);
1087
1088         /* Some directory entries inexplicibly have a little over 70 bytes of
1089          * extra data.  The exact amount of data seems to be 72 bytes, but it is
1090          * aligned on the next 8-byte boundary.  Here's an example of the
1091          * aligned data:
1092          *
1093          * 01000000400000006c786bbac58ede11b0bb00261870892ab6adb76fe63a3
1094          * e468fca86530d2effa16c786bbac58ede11b0bb00261870892a0000000000
1095          * 0000000000000000000000
1096          *
1097          * Here's one interpretation of how the data is laid out.
1098          *
1099          * struct unknown {
1100          *      u32 field1; (always 0x00000001)
1101          *      u32 field2; (always 0x40000000)
1102          *      u16 field3;
1103          *      u32 field4;
1104          *      u32 field5;
1105          *      u32 field6;
1106          *      u8  data[48]; (???)
1107          *      u64 reserved1; (always 0)
1108          *      u64 reserved2; (always 0)
1109          * };*/
1110 #if 0
1111         if (dentry->length - calculated_size >= WIM_ADS_ENTRY_DISK_SIZE) {
1112                 printf("%s: %lu / %lu (", file_name_utf8,
1113                                 calculated_size, dentry->length);
1114                 print_string(p + WIM_ADS_ENTRY_DISK_SIZE, dentry->length - calculated_size - WIM_ADS_ENTRY_DISK_SIZE);
1115                 puts(")");
1116                 print_byte_field(p, dentry->length - calculated_size);
1117                 putchar('\n');
1118         }
1119 #endif
1120
1121         if (dentry->num_ads != 0) {
1122                 calculated_size = (calculated_size + 7) & ~7;
1123                 if (calculated_size > metadata_resource_len - offset) {
1124                         ERROR("Not enough space in metadata resource for "
1125                               "alternate stream entries");
1126                         ret = WIMLIB_ERR_INVALID_DENTRY;
1127                         goto out_free_short_name;
1128                 }
1129                 ret = read_ads_entries(&metadata_resource[offset + calculated_size],
1130                                        dentry,
1131                                        metadata_resource_len - offset - calculated_size);
1132                 if (ret != 0)
1133                         goto out_free_short_name;
1134         }
1135
1136         dentry->file_name          = file_name;
1137         dentry->file_name_utf8     = file_name_utf8;
1138         dentry->short_name         = short_name;
1139         dentry->file_name_len      = file_name_len;
1140         dentry->file_name_utf8_len = file_name_utf8_len;
1141         dentry->short_name_len     = short_name_len;
1142         return 0;
1143 out_free_short_name:
1144         FREE(short_name);
1145 out_free_file_name_utf8:
1146         FREE(file_name_utf8);
1147 out_free_file_name:
1148         FREE(file_name);
1149         return ret;
1150 }
1151
1152 /*
1153  * Writes a dentry to an output buffer.
1154  *
1155  * @dentry:  The dentry structure.
1156  * @p:       The memory location to write the data to.
1157  * @return:  Pointer to the byte after the last byte we wrote as part of the
1158  *              dentry.
1159  */
1160 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
1161 {
1162         u8 *orig_p = p;
1163         unsigned padding;
1164
1165         p = put_u64(p, dentry->length);
1166         p = put_u32(p, dentry->attributes);
1167         p = put_u32(p, dentry->security_id);
1168         p = put_u64(p, dentry->subdir_offset);
1169         p = put_u64(p, 0); /* unused1 */
1170         p = put_u64(p, 0); /* unused2 */
1171         p = put_u64(p, dentry->creation_time);
1172         p = put_u64(p, dentry->last_access_time);
1173         p = put_u64(p, dentry->last_write_time);
1174         p = put_bytes(p, WIM_HASH_SIZE, dentry->hash);
1175         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1176                 p = put_zeroes(p, 4);
1177                 p = put_u32(p, dentry->reparse_tag);
1178                 p = put_zeroes(p, 4);
1179         } else {
1180                 u64 hard_link;
1181                 p = put_u32(p, dentry->reparse_tag);
1182                 if (dentry->link_group_list.next == &dentry->link_group_list)
1183                         hard_link = 0;
1184                 else
1185                         hard_link = dentry->hard_link;
1186                 p = put_u64(p, hard_link);
1187         }
1188         p = put_u16(p, dentry->num_ads);
1189         p = put_u16(p, dentry->short_name_len);
1190         p = put_u16(p, dentry->file_name_len);
1191         p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
1192         p = put_u16(p, 0); /* filename padding, 2 bytes. */
1193         p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
1194
1195         wimlib_assert(p - orig_p <= dentry->length);
1196         if (p - orig_p < dentry->length)
1197                 p = put_zeroes(p, dentry->length - (p - orig_p));
1198
1199         p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1200
1201         for (u16 i = 0; i < dentry->num_ads; i++) {
1202                 p = put_u64(p, ads_entry_length(&dentry->ads_entries[i]));
1203                 p = put_u64(p, 0); /* Unused */
1204                 p = put_bytes(p, WIM_HASH_SIZE, dentry->ads_entries[i].hash);
1205                 p = put_u16(p, dentry->ads_entries[i].stream_name_len);
1206                 p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
1207                                  (u8*)dentry->ads_entries[i].stream_name);
1208                 p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1209         }
1210         return p;
1211 }
1212
1213 /* Recursive function that writes a dentry tree rooted at @tree, not including
1214  * @tree itself, which has already been written, except in the case of the root
1215  * dentry, which is written right away, along with an end-of-directory entry. */
1216 u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
1217 {
1218         const struct dentry *child;
1219
1220         if (dentry_is_root(tree)) {
1221                 p = write_dentry(tree, p);
1222
1223                 /* write end of directory entry */
1224                 p = put_u64(p, 0);
1225         } else {
1226                 /* Nothing to do for non-directories */
1227                 if (!dentry_is_directory(tree))
1228                         return p;
1229         }
1230
1231         /* Write child dentries and end-of-directory entry. */
1232         child = tree->children;
1233         if (child) {
1234                 do {
1235                         p = write_dentry(child, p);
1236                         child = child->next;
1237                 } while (child != tree->children);
1238         }
1239
1240         /* write end of directory entry */
1241         p = put_u64(p, 0);
1242
1243         /* Recurse on children. */
1244         if (child) {
1245                 do {
1246                         p = write_dentry_tree(child, p);
1247                         child = child->next;
1248                 } while (child != tree->children);
1249         }
1250         return p;
1251 }
1252
1253 /* Reads the children of a dentry, and all their children, ..., etc. from the
1254  * metadata resource and into the dentry tree.
1255  *
1256  * @metadata_resource:  An array that contains the uncompressed metadata
1257  *                      resource for the WIM file.
1258  * @metadata_resource_len:      The length of @metadata_resource.
1259  * @dentry:     A pointer to a struct dentry that is the root of the directory
1260  *              tree and has already been read from the metadata resource.  It
1261  *              does not need to be the real root because this procedure is
1262  *              called recursively.
1263  *
1264  * @return:     Zero on success, nonzero on failure.
1265  */
1266 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1267                      struct dentry *dentry)
1268 {
1269         u64 cur_offset = dentry->subdir_offset;
1270         struct dentry *prev_child = NULL;
1271         struct dentry *first_child = NULL;
1272         struct dentry *child;
1273         struct dentry cur_child;
1274         int ret;
1275
1276         /* If @dentry is a regular file, nothing more needs to be done for this
1277          * branch. */
1278         if (cur_offset == 0)
1279                 return 0;
1280
1281         /* Find and read all the children of @dentry. */
1282         while (1) {
1283
1284                 /* Read next child of @dentry into @cur_child. */
1285                 ret = read_dentry(metadata_resource, metadata_resource_len,
1286                                   cur_offset, &cur_child);
1287                 if (ret != 0)
1288                         break;
1289
1290                 /* Check for end of directory. */
1291                 if (cur_child.length == 0) {
1292                         ret = 0;
1293                         break;
1294                 }
1295
1296                 /* Not end of directory.  Allocate this child permanently and
1297                  * link it to the parent and previous child. */
1298                 child = MALLOC(sizeof(struct dentry));
1299                 if (!child) {
1300                         ERROR("Failed to allocate %zu bytes for new dentry",
1301                               sizeof(struct dentry));
1302                         ret = WIMLIB_ERR_NOMEM;
1303                         break;
1304                 }
1305                 memcpy(child, &cur_child, sizeof(struct dentry));
1306
1307                 if (prev_child) {
1308                         prev_child->next = child;
1309                         child->prev = prev_child;
1310                 } else {
1311                         first_child = child;
1312                 }
1313
1314                 child->parent = dentry;
1315                 prev_child = child;
1316
1317                 /* If there are children of this child, call this procedure
1318                  * recursively. */
1319                 if (child->subdir_offset != 0) {
1320                         ret = read_dentry_tree(metadata_resource,
1321                                                metadata_resource_len, child);
1322                         if (ret != 0)
1323                                 break;
1324                 }
1325
1326                 /* Advance to the offset of the next child. */
1327                 cur_offset += dentry_total_length(child);
1328         }
1329
1330         /* Link last child to first one, and set parent's
1331          * children pointer to the first child.  */
1332         if (prev_child) {
1333                 prev_child->next = first_child;
1334                 first_child->prev = prev_child;
1335         }
1336         dentry->children = first_child;
1337         return ret;
1338 }