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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 /* Real length of a dentry, including the alternate data stream entries, which
  43  * are not included in the dentry->length field... */
  44 u64 dentry_total_length(const struct dentry *dentry)
  45 {
  46         u64 length = dentry->length;
  47         for (u16 i = 0 ; i < dentry->num_ads; i++)
  48                 length += ads_entry_length(&dentry->ads_entries[i]);
  49
  50         /* Round to 8 byte boundary. */
  51         return (length + 7) & ~7;
  52 }
  53
  54 /* Transfers file attributes from a `stat' buffer to a struct dentry. */
  55 void stbuf_to_dentry(const struct stat *stbuf, struct dentry *dentry)
  56 {
  57         if (S_ISDIR(stbuf->st_mode))
  58                 dentry->attributes = FILE_ATTRIBUTE_DIRECTORY;
  59         else
  60                 dentry->attributes = FILE_ATTRIBUTE_NORMAL;
  61 }
  62
  63 /* Transfers file attributes from a struct dentry to a `stat' buffer. */
  64 void dentry_to_stbuf(const struct dentry *dentry, struct stat *stbuf,
  65                      const struct lookup_table *table)
  66 {
  67         struct lookup_table_entry *lte;
  68
  69         if (dentry_is_directory(dentry))
  70                 stbuf->st_mode = S_IFDIR | 0755;
  71         else
  72                 stbuf->st_mode = S_IFREG | 0644;
  73
  74         if (table)
  75                 lte = lookup_resource(table, dentry->hash);
  76         else
  77                 lte = NULL;
  78
  79         if (lte) {
  80                 stbuf->st_nlink = lte->refcnt;
  81                 stbuf->st_size = lte->resource_entry.original_size;
  82         } else {
  83                 stbuf->st_nlink = 1;
  84                 stbuf->st_size = 0;
  85         }
  86         stbuf->st_uid     = getuid();
  87         stbuf->st_gid     = getgid();
  88         stbuf->st_atime   = ms_timestamp_to_unix(dentry->last_access_time);
  89         stbuf->st_mtime   = ms_timestamp_to_unix(dentry->last_write_time);
  90         stbuf->st_ctime   = ms_timestamp_to_unix(dentry->creation_time);
  91         stbuf->st_blocks  = (stbuf->st_size + 511) / 512;
  92 }
  93
  94 /* Makes all timestamp fields for the dentry be the current time. */
  95 void dentry_update_all_timestamps(struct dentry *dentry)
  96 {
  97         u64 now = get_timestamp();
  98         dentry->creation_time    = now;
  99         dentry->last_access_time = now;
 100         dentry->last_write_time  = now;
 101 }
 102
 103 /*
 104  * Calls a function on all directory entries in a directory tree.  It is called
 105  * on a parent before its children.
 106  */
 107 int for_dentry_in_tree(struct dentry *root,
 108                        int (*visitor)(struct dentry*, void*), void *arg)
 109 {
 110         int ret;
 111         struct dentry *child;
 112
 113         ret = visitor(root, arg);
 114
 115         if (ret != 0)
 116                 return ret;
 117
 118         child = root->children;
 119
 120         if (!child)
 121                 return 0;
 122
 123         do {
 124                 ret = for_dentry_in_tree(child, visitor, arg);
 125                 if (ret != 0)
 126                         return ret;
 127                 child = child->next;
 128         } while (child != root->children);
 129         return 0;
 130 }
 131
 132 /*
 133  * Like for_dentry_in_tree(), but the visitor function is always called on a
 134  * dentry's children before on itself.
 135  */
 136 int for_dentry_in_tree_depth(struct dentry *root,
 137                              int (*visitor)(struct dentry*, void*), void *arg)
 138 {
 139         int ret;
 140         struct dentry *child;
 141         struct dentry *next;
 142
 143         child = root->children;
 144         if (child) {
 145                 do {
 146                         next = child->next;
 147                         ret = for_dentry_in_tree_depth(child, visitor, arg);
 148                         if (ret != 0)
 149                                 return ret;
 150                         child = next;
 151                 } while (child != root->children);
 152         }
 153         return visitor(root, arg);
 154 }
 155
 156 /*
 157  * Calculate the full path of @dentry, based on its parent's full path and on
 158  * its UTF-8 file name.
 159  */
 160 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
 161 {
 162         char *full_path;
 163         u32 full_path_len;
 164         if (dentry_is_root(dentry)) {
 165                 full_path = MALLOC(2);
 166                 if (!full_path)
 167                         goto oom;
 168                 full_path[0] = '/';
 169                 full_path[1] = '\0';
 170                 full_path_len = 1;
 171         } else {
 172                 char *parent_full_path;
 173                 u32 parent_full_path_len;
 174                 const struct dentry *parent = dentry->parent;
 175
 176                 if (dentry_is_root(parent)) {
 177                         parent_full_path = "";
 178                         parent_full_path_len = 0;
 179                 } else {
 180                         parent_full_path = parent->full_path_utf8;
 181                         parent_full_path_len = parent->full_path_utf8_len;
 182                 }
 183
 184                 full_path_len = parent_full_path_len + 1 +
 185                                 dentry->file_name_utf8_len;
 186                 full_path = MALLOC(full_path_len + 1);
 187                 if (!full_path)
 188                         goto oom;
 189
 190                 memcpy(full_path, parent_full_path, parent_full_path_len);
 191                 full_path[parent_full_path_len] = '/';
 192                 memcpy(full_path + parent_full_path_len + 1,
 193                        dentry->file_name_utf8,
 194                        dentry->file_name_utf8_len);
 195                 full_path[full_path_len] = '\0';
 196         }
 197         FREE(dentry->full_path_utf8);
 198         dentry->full_path_utf8 = full_path;
 199         dentry->full_path_utf8_len = full_path_len;
 200         return 0;
 201 oom:
 202         ERROR("Out of memory while calculating dentry full path");
 203         return WIMLIB_ERR_NOMEM;
 204 }
 205
 206 /*
 207  * Recursively calculates the subdir offsets for a directory tree.
 208  *
 209  * @dentry:  The root of the directory tree.
 210  * @subdir_offset_p:  The current subdirectory offset; i.e., the subdirectory
 211  *      offset for @dentry.
 212  */
 213 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 214 {
 215         struct dentry *child;
 216
 217         child = dentry->children;
 218         dentry->subdir_offset = *subdir_offset_p;
 219         if (child) {
 220
 221                 /* Advance the subdir offset by the amount of space the children
 222                  * of this dentry take up. */
 223                 do {
 224                         *subdir_offset_p += dentry_total_length(child);
 225                         child = child->next;
 226                 } while (child != dentry->children);
 227
 228                 /* End-of-directory dentry on disk. */
 229                 *subdir_offset_p += 8;
 230
 231                 /* Recursively call calculate_subdir_offsets() on all the
 232                  * children. */
 233                 do {
 234                         calculate_subdir_offsets(child, subdir_offset_p);
 235                         child = child->next;
 236                 } while (child != dentry->children);
 237         } else {
 238                 /* On disk, childless directories have a valid subdir_offset
 239                  * that points to an 8-byte end-of-directory dentry.  Regular
 240                  * files have a subdir_offset of 0. */
 241                 if (dentry_is_directory(dentry))
 242                         *subdir_offset_p += 8;
 243                 else
 244                         dentry->subdir_offset = 0;
 245         }
 246 }
 247
 248
 249 /* Returns the child of @dentry that has the file name @name.
 250  * Returns NULL if no child has the name. */
 251 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
 252                                                         const char *name)
 253 {
 254         struct dentry *child;
 255         size_t name_len;
 256
 257         child = dentry->children;
 258         if (child) {
 259                 name_len = strlen(name);
 260                 do {
 261                         if (dentry_has_name(child, name, name_len))
 262                                 return child;
 263                         child = child->next;
 264                 } while (child != dentry->children);
 265         }
 266         return NULL;
 267 }
 268
 269 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
 270  * @cur_dir.  Returns NULL if no dentry having the path is found. */
 271 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir, const char *path)
 272 {
 273         struct dentry *child;
 274         size_t base_len;
 275         const char *new_path;
 276
 277         if (*path == '\0')
 278                 return cur_dir;
 279
 280         child = cur_dir->children;
 281         if (child) {
 282                 new_path = path_next_part(path, &base_len);
 283                 do {
 284                         if (dentry_has_name(child, path, base_len))
 285                                 return get_dentry_relative_path(child, new_path);
 286                         child = child->next;
 287                 } while (child != cur_dir->children);
 288         }
 289         return NULL;
 290 }
 291
 292 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
 293  * such dentry. */
 294 struct dentry *get_dentry(WIMStruct *w, const char *path)
 295 {
 296         struct dentry *root = wim_root_dentry(w);
 297         while (*path == '/')
 298                 path++;
 299         return get_dentry_relative_path(root, path);
 300 }
 301
 302 /* Returns the parent directory for the @path. */
 303 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
 304 {
 305         size_t path_len = strlen(path);
 306         char buf[path_len + 1];
 307
 308         memcpy(buf, path, path_len + 1);
 309
 310         to_parent_name(buf, path_len);
 311
 312         return get_dentry(w, buf);
 313 }
 314
 315 /* Prints the full path of a dentry. */
 316 int print_dentry_full_path(struct dentry *dentry, void *ignore)
 317 {
 318         if (dentry->full_path_utf8)
 319                 puts(dentry->full_path_utf8);
 320         return 0;
 321 }
 322
 323 struct file_attr_flag {
 324         u32 flag;
 325         const char *name;
 326 };
 327 struct file_attr_flag file_attr_flags[] = {
 328         {FILE_ATTRIBUTE_READONLY,               "READONLY"},
 329         {FILE_ATTRIBUTE_HIDDEN,         "HIDDEN"},
 330         {FILE_ATTRIBUTE_SYSTEM,         "SYSTEM"},
 331         {FILE_ATTRIBUTE_DIRECTORY,              "DIRECTORY"},
 332         {FILE_ATTRIBUTE_ARCHIVE,                "ARCHIVE"},
 333         {FILE_ATTRIBUTE_DEVICE,         "DEVICE"},
 334         {FILE_ATTRIBUTE_NORMAL,         "NORMAL"},
 335         {FILE_ATTRIBUTE_TEMPORARY,              "TEMPORARY"},
 336         {FILE_ATTRIBUTE_SPARSE_FILE,    "SPARSE_FILE"},
 337         {FILE_ATTRIBUTE_REPARSE_POINT,  "REPARSE_POINT"},
 338         {FILE_ATTRIBUTE_COMPRESSED,             "COMPRESSED"},
 339         {FILE_ATTRIBUTE_OFFLINE,                "OFFLINE"},
 340         {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
 341         {FILE_ATTRIBUTE_ENCRYPTED,              "ENCRYPTED"},
 342         {FILE_ATTRIBUTE_VIRTUAL,                "VIRTUAL"},
 343 };
 344
 345 /* Prints a directory entry.  @lookup_table is a pointer to the lookup table, or
 346  * NULL if the resource entry for the dentry is not to be printed. */
 347 int print_dentry(struct dentry *dentry, void *lookup_table)
 348 {
 349         struct lookup_table_entry *lte;
 350         unsigned i;
 351
 352         printf("[DENTRY]\n");
 353         printf("Length            = %"PRIu64"\n", dentry->length);
 354         printf("Attributes        = 0x%x\n", dentry->attributes);
 355         for (i = 0; i < ARRAY_LEN(file_attr_flags); i++)
 356                 if (file_attr_flags[i].flag & dentry->attributes)
 357                         printf("    FILE_ATTRIBUTE_%s is set\n",
 358                                 file_attr_flags[i].name);
 359         printf("Security ID       = %d\n", dentry->security_id);
 360         printf("Subdir offset     = %"PRIu64"\n", dentry->subdir_offset);
 361         /*printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);*/
 362         /*printf("Unused2           = %"PRIu64"\n", dentry->unused2);*/
 363         printf("Creation Time     = %"PRIu64"\n", dentry->creation_time);
 364         printf("Last Access Time  = %"PRIu64"\n", dentry->last_access_time);
 365         printf("Last Write Time   = %"PRIu64"\n", dentry->last_write_time);
 366         printf("Creation Time     = 0x%"PRIx64"\n", dentry->creation_time);
 367         printf("Hash              = ");
 368         print_hash(dentry->hash);
 369         putchar('\n');
 370         printf("Reparse Tag       = 0x%"PRIx32"\n", dentry->reparse_tag);
 371         printf("Hard Link Group   = 0x%"PRIx64"\n", dentry->hard_link);
 372         printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
 373         printf("Filename          = \"");
 374         print_string(dentry->file_name, dentry->file_name_len);
 375         puts("\"");
 376         printf("Filename Length   = %hu\n", dentry->file_name_len);
 377         printf("Filename (UTF-8)  = \"%s\"\n", dentry->file_name_utf8);
 378         printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
 379         printf("Short Name        = \"");
 380         print_string(dentry->short_name, dentry->short_name_len);
 381         puts("\"");
 382         printf("Short Name Length = %hu\n", dentry->short_name_len);
 383         printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
 384         if (lookup_table) {
 385                 lte = lookup_resource(lookup_table, dentry->hash);
 386                 if (lte)
 387                         print_lookup_table_entry(lte, NULL);
 388                 else
 389                         putchar('\n');
 390         } else {
 391                 putchar('\n');
 392         }
 393         for (u16 i = 0; i < dentry->num_ads; i++) {
 394                 printf("[Alternate Stream Entry %u]\n", i);
 395                 printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
 396                 lte = lookup_resource(lookup_table, dentry->ads_entries[i].hash);
 397                 if (lte)
 398                         print_lookup_table_entry(lte, NULL);
 399                 else
 400                         putchar('\n');
 401         }
 402         return 0;
 403 }
 404
 405 static inline void dentry_common_init(struct dentry *dentry)
 406 {
 407         memset(dentry, 0, sizeof(struct dentry));
 408         dentry->refcnt = 1;
 409         dentry->security_id = -1;
 410 }
 411
 412 /*
 413  * Creates an unlinked directory entry.
 414  *
 415  * @name:    The base name of the new dentry.
 416  * @return:  A pointer to the new dentry, or NULL if out of memory.
 417  */
 418 struct dentry *new_dentry(const char *name)
 419 {
 420         struct dentry *dentry;
 421
 422         dentry = MALLOC(sizeof(struct dentry));
 423         if (!dentry)
 424                 return NULL;
 425
 426         dentry_common_init(dentry);
 427         if (change_dentry_name(dentry, name) != 0) {
 428                 FREE(dentry);
 429                 return NULL;
 430         }
 431
 432         dentry_update_all_timestamps(dentry);
 433         dentry->next   = dentry;
 434         dentry->prev   = dentry;
 435         dentry->parent = dentry;
 436         return dentry;
 437 }
 438
 439
 440 void free_dentry(struct dentry *dentry)
 441 {
 442         FREE(dentry->file_name);
 443         FREE(dentry->file_name_utf8);
 444         FREE(dentry->short_name);
 445         FREE(dentry->full_path_utf8);
 446         FREE(dentry);
 447 }
 448
 449 /* Arguments for do_free_dentry(). */
 450 struct free_dentry_args {
 451         struct lookup_table *lookup_table;
 452         bool lt_decrement_refcnt;
 453 };
 454
 455 /*
 456  * This function is passed as an argument to for_dentry_in_tree_depth() in order
 457  * to free a directory tree.  __args is a pointer to a `struct free_dentry_args'.
 458  */
 459 static int do_free_dentry(struct dentry *dentry, void *__args)
 460 {
 461         struct free_dentry_args *args = (struct free_dentry_args*)__args;
 462
 463         if (args->lt_decrement_refcnt && !dentry_is_directory(dentry)) {
 464                 lookup_table_decrement_refcnt(args->lookup_table,
 465                                               dentry->hash);
 466         }
 467
 468         wimlib_assert(dentry->refcnt >= 1);
 469         if (--dentry->refcnt == 0)
 470                 free_dentry(dentry);
 471         return 0;
 472 }
 473
 474 /*
 475  * Unlinks and frees a dentry tree.
 476  *
 477  * @root:               The root of the tree.
 478  * @lookup_table:       The lookup table for dentries.
 479  * @decrement_refcnt:   True if the dentries in the tree are to have their
 480  *                      reference counts in the lookup table decremented.
 481  */
 482 void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table,
 483                       bool lt_decrement_refcnt)
 484 {
 485         if (!root || !root->parent)
 486                 return;
 487
 488         struct free_dentry_args args;
 489         args.lookup_table        = lookup_table;
 490         args.lt_decrement_refcnt = lt_decrement_refcnt;
 491         for_dentry_in_tree_depth(root, do_free_dentry, &args);
 492 }
 493
 494 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
 495 {
 496         dentry->refcnt++;
 497         return 0;
 498 }
 499
 500 /*
 501  * Links a dentry into the directory tree.
 502  *
 503  * @dentry: The dentry to link.
 504  * @parent: The dentry that will be the parent of @dentry.
 505  */
 506 void link_dentry(struct dentry *dentry, struct dentry *parent)
 507 {
 508         dentry->parent = parent;
 509         if (parent->children) {
 510                 /* Not an only child; link to siblings. */
 511                 dentry->next = parent->children;
 512                 dentry->prev = parent->children->prev;
 513                 dentry->next->prev = dentry;
 514                 dentry->prev->next = dentry;
 515         } else {
 516                 /* Only child; link to parent. */
 517                 parent->children = dentry;
 518                 dentry->next = dentry;
 519                 dentry->prev = dentry;
 520         }
 521 }
 522
 523 /* Unlink a dentry from the directory tree. */
 524 void unlink_dentry(struct dentry *dentry)
 525 {
 526         if (dentry_is_root(dentry))
 527                 return;
 528         if (dentry_is_only_child(dentry)) {
 529                 dentry->parent->children = NULL;
 530         } else {
 531                 if (dentry_is_first_sibling(dentry))
 532                         dentry->parent->children = dentry->next;
 533                 dentry->next->prev = dentry->prev;
 534                 dentry->prev->next = dentry->next;
 535         }
 536 }
 537
 538
 539 /* Recalculates the length of @dentry based on its file name length and short
 540  * name length.  */
 541 static inline void recalculate_dentry_size(struct dentry *dentry)
 542 {
 543         dentry->length = WIM_DENTRY_DISK_SIZE + dentry->file_name_len +
 544                          2 + dentry->short_name_len;
 545         for (u16 i = 0; i < dentry->num_ads; i++)
 546                 dentry->length += ads_entry_length(&dentry->ads_entries[i]);
 547         /* Must be multiple of 8. */
 548         dentry->length = (dentry->length + 7) & ~7;
 549 }
 550
 551 /* Changes the name of a dentry to @new_name.  Only changes the file_name and
 552  * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
 553  * full_path_utf8 fields.  Also recalculates its length. */
 554 int change_dentry_name(struct dentry *dentry, const char *new_name)
 555 {
 556         size_t utf8_len;
 557         size_t utf16_len;
 558
 559         FREE(dentry->file_name);
 560
 561         utf8_len = strlen(new_name);
 562
 563         dentry->file_name = utf8_to_utf16(new_name, utf8_len, &utf16_len);
 564
 565         if (!dentry->file_name)
 566                 return WIMLIB_ERR_NOMEM;
 567
 568         FREE(dentry->file_name_utf8);
 569         dentry->file_name_utf8 = MALLOC(utf8_len + 1);
 570         if (!dentry->file_name_utf8) {
 571                 FREE(dentry->file_name);
 572                 dentry->file_name = NULL;
 573                 return WIMLIB_ERR_NOMEM;
 574         }
 575
 576         dentry->file_name_len = utf16_len;
 577         dentry->file_name_utf8_len = utf8_len;
 578         memcpy(dentry->file_name_utf8, new_name, utf8_len + 1);
 579         recalculate_dentry_size(dentry);
 580         return 0;
 581 }
 582
 583 /* Parameters for calculate_dentry_statistics(). */
 584 struct image_statistics {
 585         struct lookup_table *lookup_table;
 586         u64 *dir_count;
 587         u64 *file_count;
 588         u64 *total_bytes;
 589         u64 *hard_link_bytes;
 590 };
 591
 592 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
 593 {
 594         struct image_statistics *stats;
 595         struct lookup_table_entry *lte;
 596
 597         stats = arg;
 598         lte = lookup_resource(stats->lookup_table, dentry->hash);
 599
 600         if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
 601                 ++*stats->dir_count;
 602         else
 603                 ++*stats->file_count;
 604
 605         if (lte) {
 606                 u64 size = lte->resource_entry.original_size;
 607                 *stats->total_bytes += size;
 608                 if (++lte->out_refcnt == 1)
 609                         *stats->hard_link_bytes += size;
 610         }
 611         return 0;
 612 }
 613
 614 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
 615                                    u64 *dir_count_ret, u64 *file_count_ret,
 616                                    u64 *total_bytes_ret,
 617                                    u64 *hard_link_bytes_ret)
 618 {
 619         struct image_statistics stats;
 620         *dir_count_ret         = 0;
 621         *file_count_ret        = 0;
 622         *total_bytes_ret       = 0;
 623         *hard_link_bytes_ret   = 0;
 624         stats.lookup_table     = table;
 625         stats.dir_count       = dir_count_ret;
 626         stats.file_count      = file_count_ret;
 627         stats.total_bytes     = total_bytes_ret;
 628         stats.hard_link_bytes = hard_link_bytes_ret;
 629         for_lookup_table_entry(table, zero_out_refcnts, NULL);
 630         for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
 631 }
 632
 633 static int read_ads_entries(const u8 *p, struct dentry *dentry,
 634                             u64 remaining_size)
 635 {
 636         u16 num_ads = dentry->num_ads;
 637         struct ads_entry *ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
 638         int ret;
 639         if (!ads_entries) {
 640                 ERROR("Could not allocate memory for %"PRIu16" "
 641                       "alternate data stream entries", num_ads);
 642                 return WIMLIB_ERR_NOMEM;
 643         }
 644         DEBUG2("Reading %"PRIu16" alternate data streams "
 645                "(remaining size = %"PRIu64")", num_ads, remaining_size);
 646
 647         for (u16 i = 0; i < num_ads; i++) {
 648                 struct ads_entry *cur_entry = &ads_entries[i];
 649                 u64 length;
 650                 size_t utf8_len;
 651                 const char *p_save = p;
 652                 /* Read the base stream entry, excluding the stream name. */
 653                 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
 654                         ERROR("Stream entries go past end of metadata resource");
 655                         ERROR("(remaining_size = %"PRIu64")", remaining_size);
 656                         ret = WIMLIB_ERR_INVALID_DENTRY;
 657                         goto out_free_ads_entries;
 658                 }
 659                 remaining_size -= WIM_ADS_ENTRY_DISK_SIZE;
 660                 /*print_string(p + 40, 10);*/
 661                 /*print_byte_field(p, 50);*/
 662
 663                 p = get_u64(p, &length); /* ADS entry length */
 664
 665                 DEBUG2("ADS length = %"PRIu64, length);
 666
 667                 p += 8; /* Unused */
 668                 p = get_bytes(p, WIM_HASH_SIZE, (u8*)cur_entry->hash);
 669                 p = get_u16(p, &cur_entry->stream_name_len);
 670
 671                 DEBUG2("Stream name length = %u", cur_entry->stream_name_len);
 672
 673                 cur_entry->stream_name = NULL;
 674                 cur_entry->stream_name_utf8 = NULL;
 675
 676                 if (remaining_size < cur_entry->stream_name_len + 2) {
 677                         ERROR("Stream entries go past end of metadata resource");
 678                         ERROR("(remaining_size = %"PRIu64" bytes, stream_name_len "
 679                               "= %"PRIu16" bytes", remaining_size,
 680                               cur_entry->stream_name_len);
 681                         ret = WIMLIB_ERR_INVALID_DENTRY;
 682                         goto out_free_ads_entries;
 683                 }
 684                 remaining_size -= cur_entry->stream_name_len + 2;
 685
 686                 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
 687                 if (!cur_entry->stream_name) {
 688                         ret = WIMLIB_ERR_NOMEM;
 689                         goto out_free_ads_entries;
 690                 }
 691                 get_bytes(p, cur_entry->stream_name_len,
 692                           (u8*)cur_entry->stream_name);
 693                 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
 694                                                             cur_entry->stream_name_len,
 695                                                             &utf8_len);
 696                 cur_entry->stream_name_len_utf8 = utf8_len;
 697
 698                 if (!cur_entry->stream_name_utf8) {
 699                         ret = WIMLIB_ERR_NOMEM;
 700                         goto out_free_ads_entries;
 701                 }
 702                 p = p_save + ads_entry_length(cur_entry);
 703         }
 704         dentry->ads_entries = ads_entries;
 705         return 0;
 706 out_free_ads_entries:
 707         for (u16 i = 0; i < num_ads; i++) {
 708                 FREE(ads_entries[i].stream_name);
 709                 FREE(ads_entries[i].stream_name_utf8);
 710         }
 711         FREE(ads_entries);
 712         return ret;
 713 }
 714
 715 /*
 716  * Reads a directory entry from the metadata resource.
 717  */
 718 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
 719                 u64 offset, struct dentry *dentry)
 720 {
 721         const u8 *p;
 722         u64 calculated_size;
 723         char *file_name;
 724         char *file_name_utf8;
 725         char *short_name;
 726         u16 short_name_len;
 727         u16 file_name_len;
 728         size_t file_name_utf8_len;
 729         int ret;
 730
 731         dentry_common_init(dentry);
 732
 733         /*Make sure the dentry really fits into the metadata resource.*/
 734         if (offset + 8 > metadata_resource_len) {
 735                 ERROR("Directory entry starting at %"PRIu64" ends past the "
 736                       "end of the metadata resource (size %"PRIu64")",
 737                       offset, metadata_resource_len);
 738                 return WIMLIB_ERR_INVALID_DENTRY;
 739         }
 740
 741         /* Before reading the whole entry, we need to read just the length.
 742          * This is because an entry of length 8 (that is, just the length field)
 743          * terminates the list of sibling directory entries. */
 744
 745         p = get_u64(&metadata_resource[offset], &dentry->length);
 746
 747         /* A zero length field (really a length of 8, since that's how big the
 748          * directory entry is...) indicates that this is the end of directory
 749          * dentry.  We do not read it into memory as an actual dentry, so just
 750          * return true in that case. */
 751         if (dentry->length == 0)
 752                 return 0;
 753
 754         if (offset + dentry->length >= metadata_resource_len) {
 755                 ERROR("Directory entry at offset %"PRIu64" and with size "
 756                       "%"PRIu64" ends past the end of the metadata resource "
 757                       "(size %"PRIu64")",
 758                       offset, dentry->length, metadata_resource_len);
 759                 return WIMLIB_ERR_INVALID_DENTRY;
 760         }
 761
 762         /* If it is a recognized length, read the rest of the directory entry.
 763          * Note: The root directory entry has no name, and its length does not
 764          * include the short name length field.  */
 765         if (dentry->length < WIM_DENTRY_DISK_SIZE) {
 766                 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
 767                       dentry->length);
 768                 return WIMLIB_ERR_INVALID_DENTRY;
 769         }
 770
 771         p = get_u32(p, &dentry->attributes);
 772         p = get_u32(p, (u32*)&dentry->security_id);
 773         p = get_u64(p, &dentry->subdir_offset);
 774
 775         /* 2 unused fields */
 776         p += 2 * sizeof(u64);
 777         /*p = get_u64(p, &dentry->unused1);*/
 778         /*p = get_u64(p, &dentry->unused2);*/
 779
 780         p = get_u64(p, &dentry->creation_time);
 781         p = get_u64(p, &dentry->last_access_time);
 782         p = get_u64(p, &dentry->last_write_time);
 783
 784         p = get_bytes(p, WIM_HASH_SIZE, dentry->hash);
 785
 786         /*
 787          * I don't know what's going on here.  It seems like M$ screwed up the
 788          * reparse points, then put the fields in the same place and didn't
 789          * document it.  The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
 790          * have something to do with this, but it's not documented.
 791          */
 792         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 793                 /* ??? */
 794                 u32 u1, u2;
 795                 p = get_u32(p, &u1);
 796                 /*p += 4;*/
 797                 p = get_u32(p, &dentry->reparse_tag);
 798                 p = get_u32(p, &u2);
 799                 /*p += 4;*/
 800                 dentry->hard_link = (u64)(u1) | ((u64)(u2) << 32);
 801         } else {
 802                 p = get_u32(p, &dentry->reparse_tag);
 803                 p = get_u64(p, &dentry->hard_link);
 804         }
 805
 806         /* By the way, the reparse_reserved field does not actually exist (at
 807          * least when the file is not a reparse point) */
 808
 809
 810         p = get_u16(p, &dentry->num_ads);
 811
 812         p = get_u16(p, &short_name_len);
 813         p = get_u16(p, &file_name_len);
 814
 815         calculated_size = WIM_DENTRY_DISK_SIZE + file_name_len + 2 +
 816                           short_name_len;
 817
 818         if (dentry->length < calculated_size) {
 819                 ERROR("Unexpected end of directory entry! (Expected "
 820                       "%"PRIu64" bytes, got %"PRIu64" bytes. "
 821                       "short_name_len = %hu, file_name_len = %hu)",
 822                       calculated_size, dentry->length,
 823                       short_name_len, file_name_len);
 824                 return WIMLIB_ERR_INVALID_DENTRY;
 825         }
 826
 827         /* Read the filename. */
 828         file_name = MALLOC(file_name_len);
 829         if (!file_name) {
 830                 ERROR("Failed to allocate %hu bytes for dentry file name",
 831                       file_name_len);
 832                 return WIMLIB_ERR_NOMEM;
 833         }
 834         p = get_bytes(p, file_name_len, file_name);
 835
 836         /* Convert filename to UTF-8. */
 837         file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
 838                                        &file_name_utf8_len);
 839
 840         if (!file_name_utf8) {
 841                 ERROR("Failed to allocate memory to convert UTF-16 "
 842                       "filename (%hu bytes) to UTF-8", file_name_len);
 843                 ret = WIMLIB_ERR_NOMEM;
 844                 goto out_free_file_name;
 845         }
 846
 847         /* Undocumented padding between file name and short name.  This probably
 848          * is supposed to be a terminating null character. */
 849         p += 2;
 850
 851         /* Read the short filename. */
 852         short_name = MALLOC(short_name_len);
 853         if (!short_name) {
 854                 ERROR("Failed to allocate %hu bytes for short filename",
 855                       short_name_len);
 856                 ret = WIMLIB_ERR_NOMEM;
 857                 goto out_free_file_name_utf8;
 858         }
 859
 860         p = get_bytes(p, short_name_len, short_name);
 861
 862         /* Some directory entries inexplicibly have a little over 70 bytes of
 863          * extra data.  The exact amount of data seems to be 72 bytes, but it is
 864          * aligned on the next 8-byte boundary.  Here's an example of the
 865          * aligned data:
 866          *
 867          * 01000000400000006c786bbac58ede11b0bb00261870892ab6adb76fe63a3
 868          * e468fca86530d2effa16c786bbac58ede11b0bb00261870892a0000000000
 869          * 0000000000000000000000
 870          *
 871          * Here's one interpretation of how the data is laid out.
 872          *
 873          * struct unknown {
 874          *      u32 field1; (always 0x00000001)
 875          *      u32 field2; (always 0x40000000)
 876          *      u16 field3;
 877          *      u32 field4;
 878          *      u32 field5;
 879          *      u32 field6;
 880          *      u8  data[48]; (???)
 881          *      u64 reserved1; (always 0)
 882          *      u64 reserved2; (always 0)
 883          * };*/
 884 #if 0
 885         if (dentry->length - calculated_size >= WIM_ADS_ENTRY_DISK_SIZE) {
 886                 printf("%s: %lu / %lu (", file_name_utf8,
 887                                 calculated_size, dentry->length);
 888                 print_string(p + WIM_ADS_ENTRY_DISK_SIZE, dentry->length - calculated_size - WIM_ADS_ENTRY_DISK_SIZE);
 889                 puts(")");
 890                 print_byte_field(p, dentry->length - calculated_size);
 891                 putchar('\n');
 892         }
 893 #endif
 894
 895         if (dentry->num_ads != 0) {
 896                 ret = read_ads_entries(p, dentry,
 897                                        metadata_resource_len - offset - calculated_size);
 898                 if (ret != 0)
 899                         goto out_free_short_name;
 900         }
 901
 902         dentry->file_name          = file_name;
 903         dentry->file_name_utf8     = file_name_utf8;
 904         dentry->short_name         = short_name;
 905         dentry->file_name_len      = file_name_len;
 906         dentry->file_name_utf8_len = file_name_utf8_len;
 907         dentry->short_name_len     = short_name_len;
 908         return 0;
 909 out_free_short_name:
 910         FREE(short_name);
 911 out_free_file_name_utf8:
 912         FREE(file_name_utf8);
 913 out_free_file_name:
 914         FREE(file_name);
 915         return ret;
 916 }
 917
 918 /*
 919  * Writes a dentry to an output buffer.
 920  *
 921  * @dentry:  The dentry structure.
 922  * @p:       The memory location to write the data to.
 923  * @return:  Pointer to the byte after the last byte we wrote as part of the
 924  *              dentry.
 925  */
 926 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
 927 {
 928         u8 *orig_p = p;
 929         memset(p, 0, dentry->length);
 930         p = put_u64(p, dentry->length);
 931         p = put_u32(p, dentry->attributes);
 932         p = put_u32(p, dentry->security_id);
 933         p = put_u64(p, dentry->subdir_offset);
 934         p = put_u64(p, 0); /* unused1 */
 935         p = put_u64(p, 0); /* unused2 */
 936         p = put_u64(p, dentry->creation_time);
 937         p = put_u64(p, dentry->last_access_time);
 938         p = put_u64(p, dentry->last_write_time);
 939         memcpy(p, dentry->hash, WIM_HASH_SIZE);
 940         p += WIM_HASH_SIZE;
 941         p = put_u32(p, dentry->reparse_tag);
 942         p = put_u64(p, dentry->hard_link);
 943         p = put_u16(p, dentry->num_ads); /*streams */
 944         p = put_u16(p, dentry->short_name_len);
 945         p = put_u16(p, dentry->file_name_len);
 946         p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
 947         p = put_u16(p, 0); /* filename padding, 2 bytes. */
 948         p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
 949         for (u16 i = 0; i < dentry->num_ads; i++) {
 950                 p = put_u64(p, ads_entry_length(&dentry->ads_entries[i]));
 951                 p = put_u64(p, 0); /* Unused */
 952                 p = put_bytes(p, WIM_HASH_SIZE, dentry->ads_entries[i].hash);
 953                 p = put_u16(p, dentry->ads_entries[i].stream_name_len);
 954                 p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
 955                                  (u8*)dentry->ads_entries[i].stream_name);
 956         }
 957         return orig_p + dentry->length;
 958 }
 959
 960 /* Recursive function that writes a dentry tree rooted at @tree, not including
 961  * @tree itself, which has already been written, except in the case of the root
 962  * dentry, which is written right away, along with an end-of-directory entry. */
 963 u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
 964 {
 965         const struct dentry *child;
 966
 967         if (dentry_is_root(tree)) {
 968                 p = write_dentry(tree, p);
 969
 970                 /* write end of directory entry */
 971                 p = put_u64(p, 0);
 972         } else {
 973                 /* Nothing to do for a regular file. */
 974                 if (dentry_is_regular_file(tree))
 975                         return p;
 976         }
 977
 978         /* Write child dentries and end-of-directory entry. */
 979         child = tree->children;
 980         if (child) {
 981                 do {
 982                         p = write_dentry(child, p);
 983                         child = child->next;
 984                 } while (child != tree->children);
 985         }
 986
 987         /* write end of directory entry */
 988         p = put_u64(p, 0);
 989
 990         /* Recurse on children. */
 991         if (child) {
 992                 do {
 993                         p = write_dentry_tree(child, p);
 994                         child = child->next;
 995                 } while (child != tree->children);
 996         }
 997         return p;
 998 }
 999
1000 /* Reads the children of a dentry, and all their children, ..., etc. from the
1001  * metadata resource and into the dentry tree.
1002  *
1003  * @metadata_resource:  An array that contains the uncompressed metadata
1004  *                      resource for the WIM file.
1005  * @metadata_resource_len:      The length of @metadata_resource.
1006  * @dentry:     A pointer to a struct dentry that is the root of the directory
1007  *              tree and has already been read from the metadata resource.  It
1008  *              does not need to be the real root because this procedure is
1009  *              called recursively.
1010  *
1011  * @return:     Zero on success, nonzero on failure.
1012  */
1013 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1014                      struct dentry *dentry)
1015 {
1016         u64 cur_offset = dentry->subdir_offset;
1017         struct dentry *prev_child = NULL;
1018         struct dentry *first_child = NULL;
1019         struct dentry *child;
1020         struct dentry cur_child;
1021         int ret;
1022
1023         /* If @dentry is a regular file, nothing more needs to be done for this
1024          * branch. */
1025         if (cur_offset == 0)
1026                 return 0;
1027
1028         /* Find and read all the children of @dentry. */
1029         while (1) {
1030
1031                 /* Read next child of @dentry into @cur_child. */
1032                 ret = read_dentry(metadata_resource, metadata_resource_len,
1033                                   cur_offset, &cur_child);
1034                 if (ret != 0)
1035                         break;
1036
1037                 /* Check for end of directory. */
1038                 if (cur_child.length == 0) {
1039                         ret = 0;
1040                         break;
1041                 }
1042
1043                 /* Not end of directory.  Allocate this child permanently and
1044                  * link it to the parent and previous child. */
1045                 child = MALLOC(sizeof(struct dentry));
1046                 if (!child) {
1047                         ERROR("Failed to allocate %zu bytes for new dentry",
1048                               sizeof(struct dentry));
1049                         ret = WIMLIB_ERR_NOMEM;
1050                         break;
1051                 }
1052                 memcpy(child, &cur_child, sizeof(struct dentry));
1053
1054                 if (prev_child) {
1055                         prev_child->next = child;
1056                         child->prev = prev_child;
1057                 } else {
1058                         first_child = child;
1059                 }
1060
1061                 child->parent = dentry;
1062                 prev_child = child;
1063
1064                 /* If there are children of this child, call this procedure
1065                  * recursively. */
1066                 if (child->subdir_offset != 0) {
1067                         ret = read_dentry_tree(metadata_resource,
1068                                                metadata_resource_len, child);
1069                         if (ret != 0)
1070                                 break;
1071                 }
1072
1073                 /* Advance to the offset of the next child. */
1074                 cur_offset += dentry_total_length(child);
1075         }
1076
1077         /* Link last child to first one, and set parent's
1078          * children pointer to the first child.  */
1079         if (prev_child) {
1080                 prev_child->next = first_child;
1081                 first_child->prev = prev_child;
1082         }
1083         dentry->children = first_child;
1084         return ret;
1085 }