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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 + 7) & ~7;
  47         for (u16 i = 0 ; i < dentry->num_ads; i++)
  48                 length += ads_entry_length(&dentry->ads_entries[i]);
  49         return length;
  50 }
  51
  52 /* Transfers file attributes from a `stat' buffer to a struct dentry. */
  53 void stbuf_to_dentry(const struct stat *stbuf, struct dentry *dentry)
  54 {
  55         if (S_ISDIR(stbuf->st_mode))
  56                 dentry->attributes = FILE_ATTRIBUTE_DIRECTORY;
  57         else
  58                 dentry->attributes = FILE_ATTRIBUTE_NORMAL;
  59 }
  60
  61 /* Transfers file attributes from a struct dentry to a `stat' buffer. */
  62 void dentry_to_stbuf(const struct dentry *dentry, struct stat *stbuf,
  63                      const struct lookup_table *table)
  64 {
  65         struct lookup_table_entry *lte;
  66
  67         if (dentry_is_directory(dentry))
  68                 stbuf->st_mode = S_IFDIR | 0755;
  69         else
  70                 stbuf->st_mode = S_IFREG | 0644;
  71
  72         if (table)
  73                 lte = lookup_resource(table, dentry->hash);
  74         else
  75                 lte = NULL;
  76
  77         if (lte) {
  78                 stbuf->st_nlink = lte->refcnt;
  79                 stbuf->st_size = lte->resource_entry.original_size;
  80         } else {
  81                 stbuf->st_nlink = 1;
  82                 stbuf->st_size = 0;
  83         }
  84         stbuf->st_uid     = getuid();
  85         stbuf->st_gid     = getgid();
  86         stbuf->st_atime   = ms_timestamp_to_unix(dentry->last_access_time);
  87         stbuf->st_mtime   = ms_timestamp_to_unix(dentry->last_write_time);
  88         stbuf->st_ctime   = ms_timestamp_to_unix(dentry->creation_time);
  89         stbuf->st_blocks  = (stbuf->st_size + 511) / 512;
  90 }
  91
  92 /* Makes all timestamp fields for the dentry be the current time. */
  93 void dentry_update_all_timestamps(struct dentry *dentry)
  94 {
  95         u64 now = get_timestamp();
  96         dentry->creation_time    = now;
  97         dentry->last_access_time = now;
  98         dentry->last_write_time  = now;
  99 }
 100
 101 /*
 102  * Calls a function on all directory entries in a directory tree.  It is called
 103  * on a parent before its children.
 104  */
 105 int for_dentry_in_tree(struct dentry *root,
 106                        int (*visitor)(struct dentry*, void*), void *arg)
 107 {
 108         int ret;
 109         struct dentry *child;
 110
 111         ret = visitor(root, arg);
 112
 113         if (ret != 0)
 114                 return ret;
 115
 116         child = root->children;
 117
 118         if (!child)
 119                 return 0;
 120
 121         do {
 122                 ret = for_dentry_in_tree(child, visitor, arg);
 123                 if (ret != 0)
 124                         return ret;
 125                 child = child->next;
 126         } while (child != root->children);
 127         return 0;
 128 }
 129
 130 /*
 131  * Like for_dentry_in_tree(), but the visitor function is always called on a
 132  * dentry's children before on itself.
 133  */
 134 int for_dentry_in_tree_depth(struct dentry *root,
 135                              int (*visitor)(struct dentry*, void*), void *arg)
 136 {
 137         int ret;
 138         struct dentry *child;
 139         struct dentry *next;
 140
 141         child = root->children;
 142         if (child) {
 143                 do {
 144                         next = child->next;
 145                         ret = for_dentry_in_tree_depth(child, visitor, arg);
 146                         if (ret != 0)
 147                                 return ret;
 148                         child = next;
 149                 } while (child != root->children);
 150         }
 151         return visitor(root, arg);
 152 }
 153
 154 /*
 155  * Calculate the full path of @dentry, based on its parent's full path and on
 156  * its UTF-8 file name.
 157  */
 158 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
 159 {
 160         char *full_path;
 161         u32 full_path_len;
 162         if (dentry_is_root(dentry)) {
 163                 full_path = MALLOC(2);
 164                 if (!full_path)
 165                         goto oom;
 166                 full_path[0] = '/';
 167                 full_path[1] = '\0';
 168                 full_path_len = 1;
 169         } else {
 170                 char *parent_full_path;
 171                 u32 parent_full_path_len;
 172                 const struct dentry *parent = dentry->parent;
 173
 174                 if (dentry_is_root(parent)) {
 175                         parent_full_path = "";
 176                         parent_full_path_len = 0;
 177                 } else {
 178                         parent_full_path = parent->full_path_utf8;
 179                         parent_full_path_len = parent->full_path_utf8_len;
 180                 }
 181
 182                 full_path_len = parent_full_path_len + 1 +
 183                                 dentry->file_name_utf8_len;
 184                 full_path = MALLOC(full_path_len + 1);
 185                 if (!full_path)
 186                         goto oom;
 187
 188                 memcpy(full_path, parent_full_path, parent_full_path_len);
 189                 full_path[parent_full_path_len] = '/';
 190                 memcpy(full_path + parent_full_path_len + 1,
 191                        dentry->file_name_utf8,
 192                        dentry->file_name_utf8_len);
 193                 full_path[full_path_len] = '\0';
 194         }
 195         FREE(dentry->full_path_utf8);
 196         dentry->full_path_utf8 = full_path;
 197         dentry->full_path_utf8_len = full_path_len;
 198         return 0;
 199 oom:
 200         ERROR("Out of memory while calculating dentry full path");
 201         return WIMLIB_ERR_NOMEM;
 202 }
 203
 204 /*
 205  * Recursively calculates the subdir offsets for a directory tree.
 206  *
 207  * @dentry:  The root of the directory tree.
 208  * @subdir_offset_p:  The current subdirectory offset; i.e., the subdirectory
 209  *      offset for @dentry.
 210  */
 211 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 212 {
 213         struct dentry *child;
 214
 215         child = dentry->children;
 216         dentry->subdir_offset = *subdir_offset_p;
 217         if (child) {
 218
 219                 /* Advance the subdir offset by the amount of space the children
 220                  * of this dentry take up. */
 221                 do {
 222                         *subdir_offset_p += dentry_total_length(child);
 223                         child = child->next;
 224                 } while (child != dentry->children);
 225
 226                 /* End-of-directory dentry on disk. */
 227                 *subdir_offset_p += 8;
 228
 229                 /* Recursively call calculate_subdir_offsets() on all the
 230                  * children. */
 231                 do {
 232                         calculate_subdir_offsets(child, subdir_offset_p);
 233                         child = child->next;
 234                 } while (child != dentry->children);
 235         } else {
 236                 /* On disk, childless directories have a valid subdir_offset
 237                  * that points to an 8-byte end-of-directory dentry.  Regular
 238                  * files have a subdir_offset of 0. */
 239                 if (dentry_is_directory(dentry))
 240                         *subdir_offset_p += 8;
 241                 else
 242                         dentry->subdir_offset = 0;
 243         }
 244 }
 245
 246
 247 /* Returns the child of @dentry that has the file name @name.
 248  * Returns NULL if no child has the name. */
 249 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
 250                                                         const char *name)
 251 {
 252         struct dentry *child;
 253         size_t name_len;
 254
 255         child = dentry->children;
 256         if (child) {
 257                 name_len = strlen(name);
 258                 do {
 259                         if (dentry_has_name(child, name, name_len))
 260                                 return child;
 261                         child = child->next;
 262                 } while (child != dentry->children);
 263         }
 264         return NULL;
 265 }
 266
 267 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
 268  * @cur_dir.  Returns NULL if no dentry having the path is found. */
 269 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir, const char *path)
 270 {
 271         struct dentry *child;
 272         size_t base_len;
 273         const char *new_path;
 274
 275         if (*path == '\0')
 276                 return cur_dir;
 277
 278         child = cur_dir->children;
 279         if (child) {
 280                 new_path = path_next_part(path, &base_len);
 281                 do {
 282                         if (dentry_has_name(child, path, base_len))
 283                                 return get_dentry_relative_path(child, new_path);
 284                         child = child->next;
 285                 } while (child != cur_dir->children);
 286         }
 287         return NULL;
 288 }
 289
 290 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
 291  * such dentry. */
 292 struct dentry *get_dentry(WIMStruct *w, const char *path)
 293 {
 294         struct dentry *root = wim_root_dentry(w);
 295         while (*path == '/')
 296                 path++;
 297         return get_dentry_relative_path(root, path);
 298 }
 299
 300 /* Returns the parent directory for the @path. */
 301 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
 302 {
 303         size_t path_len = strlen(path);
 304         char buf[path_len + 1];
 305
 306         memcpy(buf, path, path_len + 1);
 307
 308         to_parent_name(buf, path_len);
 309
 310         return get_dentry(w, buf);
 311 }
 312
 313 /* Prints the full path of a dentry. */
 314 int print_dentry_full_path(struct dentry *dentry, void *ignore)
 315 {
 316         if (dentry->full_path_utf8)
 317                 puts(dentry->full_path_utf8);
 318         return 0;
 319 }
 320
 321 struct file_attr_flag {
 322         u32 flag;
 323         const char *name;
 324 };
 325 struct file_attr_flag file_attr_flags[] = {
 326         {FILE_ATTRIBUTE_READONLY,               "READONLY"},
 327         {FILE_ATTRIBUTE_HIDDEN,         "HIDDEN"},
 328         {FILE_ATTRIBUTE_SYSTEM,         "SYSTEM"},
 329         {FILE_ATTRIBUTE_DIRECTORY,              "DIRECTORY"},
 330         {FILE_ATTRIBUTE_ARCHIVE,                "ARCHIVE"},
 331         {FILE_ATTRIBUTE_DEVICE,         "DEVICE"},
 332         {FILE_ATTRIBUTE_NORMAL,         "NORMAL"},
 333         {FILE_ATTRIBUTE_TEMPORARY,              "TEMPORARY"},
 334         {FILE_ATTRIBUTE_SPARSE_FILE,    "SPARSE_FILE"},
 335         {FILE_ATTRIBUTE_REPARSE_POINT,  "REPARSE_POINT"},
 336         {FILE_ATTRIBUTE_COMPRESSED,             "COMPRESSED"},
 337         {FILE_ATTRIBUTE_OFFLINE,                "OFFLINE"},
 338         {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
 339         {FILE_ATTRIBUTE_ENCRYPTED,              "ENCRYPTED"},
 340         {FILE_ATTRIBUTE_VIRTUAL,                "VIRTUAL"},
 341 };
 342
 343 /* Prints a directory entry.  @lookup_table is a pointer to the lookup table, or
 344  * NULL if the resource entry for the dentry is not to be printed. */
 345 int print_dentry(struct dentry *dentry, void *lookup_table)
 346 {
 347         struct lookup_table_entry *lte;
 348         unsigned i;
 349
 350         printf("[DENTRY]\n");
 351         printf("Length            = %"PRIu64"\n", dentry->length);
 352         printf("Attributes        = 0x%x\n", dentry->attributes);
 353         for (i = 0; i < ARRAY_LEN(file_attr_flags); i++)
 354                 if (file_attr_flags[i].flag & dentry->attributes)
 355                         printf("    FILE_ATTRIBUTE_%s is set\n",
 356                                 file_attr_flags[i].name);
 357         printf("Security ID       = %d\n", dentry->security_id);
 358         printf("Subdir offset     = %"PRIu64"\n", dentry->subdir_offset);
 359         /*printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);*/
 360         /*printf("Unused2           = %"PRIu64"\n", dentry->unused2);*/
 361         printf("Creation Time     = %"PRIu64"\n", dentry->creation_time);
 362         printf("Last Access Time  = %"PRIu64"\n", dentry->last_access_time);
 363         printf("Last Write Time   = %"PRIu64"\n", dentry->last_write_time);
 364         printf("Creation Time     = 0x%"PRIx64"\n", dentry->creation_time);
 365         printf("Hash              = ");
 366         print_hash(dentry->hash);
 367         putchar('\n');
 368         printf("Reparse Tag       = 0x%"PRIx32"\n", dentry->reparse_tag);
 369         printf("Hard Link Group   = 0x%"PRIx64"\n", dentry->hard_link);
 370         printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
 371         printf("Filename          = \"");
 372         print_string(dentry->file_name, dentry->file_name_len);
 373         puts("\"");
 374         printf("Filename Length   = %hu\n", dentry->file_name_len);
 375         printf("Filename (UTF-8)  = \"%s\"\n", dentry->file_name_utf8);
 376         printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
 377         printf("Short Name        = \"");
 378         print_string(dentry->short_name, dentry->short_name_len);
 379         puts("\"");
 380         printf("Short Name Length = %hu\n", dentry->short_name_len);
 381         printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
 382         if (lookup_table) {
 383                 lte = lookup_resource(lookup_table, dentry->hash);
 384                 if (lte)
 385                         print_lookup_table_entry(lte, NULL);
 386                 else
 387                         putchar('\n');
 388         } else {
 389                 putchar('\n');
 390         }
 391         for (u16 i = 0; i < dentry->num_ads; i++) {
 392                 printf("[Alternate Stream Entry %u]\n", i);
 393                 printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
 394                 printf("Name Length (UTF-16) = %u\n",
 395                                 dentry->ads_entries[i].stream_name_len);
 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         /* Must be multiple of 8. */
 546         dentry->length = (dentry->length + 7) & ~7;
 547 }
 548
 549 /* Changes the name of a dentry to @new_name.  Only changes the file_name and
 550  * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
 551  * full_path_utf8 fields.  Also recalculates its length. */
 552 int change_dentry_name(struct dentry *dentry, const char *new_name)
 553 {
 554         size_t utf8_len;
 555         size_t utf16_len;
 556
 557         FREE(dentry->file_name);
 558
 559         utf8_len = strlen(new_name);
 560
 561         dentry->file_name = utf8_to_utf16(new_name, utf8_len, &utf16_len);
 562
 563         if (!dentry->file_name)
 564                 return WIMLIB_ERR_NOMEM;
 565
 566         FREE(dentry->file_name_utf8);
 567         dentry->file_name_utf8 = MALLOC(utf8_len + 1);
 568         if (!dentry->file_name_utf8) {
 569                 FREE(dentry->file_name);
 570                 dentry->file_name = NULL;
 571                 return WIMLIB_ERR_NOMEM;
 572         }
 573
 574         dentry->file_name_len = utf16_len;
 575         dentry->file_name_utf8_len = utf8_len;
 576         memcpy(dentry->file_name_utf8, new_name, utf8_len + 1);
 577         recalculate_dentry_size(dentry);
 578         return 0;
 579 }
 580
 581 /* Parameters for calculate_dentry_statistics(). */
 582 struct image_statistics {
 583         struct lookup_table *lookup_table;
 584         u64 *dir_count;
 585         u64 *file_count;
 586         u64 *total_bytes;
 587         u64 *hard_link_bytes;
 588 };
 589
 590 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
 591 {
 592         struct image_statistics *stats;
 593         struct lookup_table_entry *lte;
 594
 595         stats = arg;
 596         lte = lookup_resource(stats->lookup_table, dentry->hash);
 597
 598         if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
 599                 ++*stats->dir_count;
 600         else
 601                 ++*stats->file_count;
 602
 603         if (lte) {
 604                 u64 size = lte->resource_entry.original_size;
 605                 *stats->total_bytes += size;
 606                 if (++lte->out_refcnt == 1)
 607                         *stats->hard_link_bytes += size;
 608         }
 609         return 0;
 610 }
 611
 612 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
 613                                    u64 *dir_count_ret, u64 *file_count_ret,
 614                                    u64 *total_bytes_ret,
 615                                    u64 *hard_link_bytes_ret)
 616 {
 617         struct image_statistics stats;
 618         *dir_count_ret         = 0;
 619         *file_count_ret        = 0;
 620         *total_bytes_ret       = 0;
 621         *hard_link_bytes_ret   = 0;
 622         stats.lookup_table     = table;
 623         stats.dir_count       = dir_count_ret;
 624         stats.file_count      = file_count_ret;
 625         stats.total_bytes     = total_bytes_ret;
 626         stats.hard_link_bytes = hard_link_bytes_ret;
 627         for_lookup_table_entry(table, zero_out_refcnts, NULL);
 628         for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
 629 }
 630
 631 static int read_ads_entries(const u8 *p, struct dentry *dentry,
 632                             u64 remaining_size)
 633 {
 634         u16 num_ads = dentry->num_ads;
 635         struct ads_entry *ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
 636         int ret;
 637         if (!ads_entries) {
 638                 ERROR("Could not allocate memory for %"PRIu16" "
 639                       "alternate data stream entries", num_ads);
 640                 return WIMLIB_ERR_NOMEM;
 641         }
 642         DEBUG2("Reading %"PRIu16" alternate data streams "
 643                "(remaining size = %"PRIu64")", num_ads, remaining_size);
 644
 645         for (u16 i = 0; i < num_ads; i++) {
 646                 struct ads_entry *cur_entry = &ads_entries[i];
 647                 u64 length;
 648                 size_t utf8_len;
 649                 const char *p_save = p;
 650                 /* Read the base stream entry, excluding the stream name. */
 651                 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
 652                         ERROR("Stream entries go past end of metadata resource");
 653                         ERROR("(remaining_size = %"PRIu64")", remaining_size);
 654                         ret = WIMLIB_ERR_INVALID_DENTRY;
 655                         goto out_free_ads_entries;
 656                 }
 657                 remaining_size -= WIM_ADS_ENTRY_DISK_SIZE;
 658
 659                 p = get_u64(p, &length); /* ADS entry length */
 660
 661                 DEBUG2("ADS length = %"PRIu64, length);
 662
 663                 p += 8; /* Unused */
 664                 p = get_bytes(p, WIM_HASH_SIZE, (u8*)cur_entry->hash);
 665                 p = get_u16(p, &cur_entry->stream_name_len);
 666
 667                 DEBUG2("Stream name length = %u", cur_entry->stream_name_len);
 668
 669                 cur_entry->stream_name = NULL;
 670                 cur_entry->stream_name_utf8 = NULL;
 671
 672                 if (remaining_size < cur_entry->stream_name_len + 2) {
 673                         ERROR("Stream entries go past end of metadata resource");
 674                         ERROR("(remaining_size = %"PRIu64" bytes, stream_name_len "
 675                               "= %"PRIu16" bytes", remaining_size,
 676                               cur_entry->stream_name_len);
 677                         ret = WIMLIB_ERR_INVALID_DENTRY;
 678                         goto out_free_ads_entries;
 679                 }
 680                 remaining_size -= cur_entry->stream_name_len + 2;
 681
 682                 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
 683                 if (!cur_entry->stream_name) {
 684                         ret = WIMLIB_ERR_NOMEM;
 685                         goto out_free_ads_entries;
 686                 }
 687                 get_bytes(p, cur_entry->stream_name_len,
 688                           (u8*)cur_entry->stream_name);
 689                 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
 690                                                             cur_entry->stream_name_len,
 691                                                             &utf8_len);
 692                 cur_entry->stream_name_len_utf8 = utf8_len;
 693
 694                 if (!cur_entry->stream_name_utf8) {
 695                         ret = WIMLIB_ERR_NOMEM;
 696                         goto out_free_ads_entries;
 697                 }
 698                 p = p_save + ads_entry_length(cur_entry);
 699         }
 700         dentry->ads_entries = ads_entries;
 701         return 0;
 702 out_free_ads_entries:
 703         for (u16 i = 0; i < num_ads; i++) {
 704                 FREE(ads_entries[i].stream_name);
 705                 FREE(ads_entries[i].stream_name_utf8);
 706         }
 707         FREE(ads_entries);
 708         return ret;
 709 }
 710
 711 /*
 712  * Reads a directory entry from the metadata resource.
 713  */
 714 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
 715                 u64 offset, struct dentry *dentry)
 716 {
 717         const u8 *p;
 718         u64 calculated_size;
 719         char *file_name;
 720         char *file_name_utf8;
 721         char *short_name;
 722         u16 short_name_len;
 723         u16 file_name_len;
 724         size_t file_name_utf8_len;
 725         int ret;
 726
 727         dentry_common_init(dentry);
 728
 729         /*Make sure the dentry really fits into the metadata resource.*/
 730         if (offset + 8 > metadata_resource_len) {
 731                 ERROR("Directory entry starting at %"PRIu64" ends past the "
 732                       "end of the metadata resource (size %"PRIu64")",
 733                       offset, metadata_resource_len);
 734                 return WIMLIB_ERR_INVALID_DENTRY;
 735         }
 736
 737         /* Before reading the whole entry, we need to read just the length.
 738          * This is because an entry of length 8 (that is, just the length field)
 739          * terminates the list of sibling directory entries. */
 740
 741         p = get_u64(&metadata_resource[offset], &dentry->length);
 742
 743         /* A zero length field (really a length of 8, since that's how big the
 744          * directory entry is...) indicates that this is the end of directory
 745          * dentry.  We do not read it into memory as an actual dentry, so just
 746          * return true in that case. */
 747         if (dentry->length == 0)
 748                 return 0;
 749
 750         if (offset + dentry->length >= metadata_resource_len) {
 751                 ERROR("Directory entry at offset %"PRIu64" and with size "
 752                       "%"PRIu64" ends past the end of the metadata resource "
 753                       "(size %"PRIu64")",
 754                       offset, dentry->length, metadata_resource_len);
 755                 return WIMLIB_ERR_INVALID_DENTRY;
 756         }
 757
 758         /* If it is a recognized length, read the rest of the directory entry.
 759          * Note: The root directory entry has no name, and its length does not
 760          * include the short name length field.  */
 761         if (dentry->length < WIM_DENTRY_DISK_SIZE) {
 762                 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
 763                       dentry->length);
 764                 return WIMLIB_ERR_INVALID_DENTRY;
 765         }
 766
 767         p = get_u32(p, &dentry->attributes);
 768         p = get_u32(p, (u32*)&dentry->security_id);
 769         p = get_u64(p, &dentry->subdir_offset);
 770
 771         /* 2 unused fields */
 772         p += 2 * sizeof(u64);
 773         /*p = get_u64(p, &dentry->unused1);*/
 774         /*p = get_u64(p, &dentry->unused2);*/
 775
 776         p = get_u64(p, &dentry->creation_time);
 777         p = get_u64(p, &dentry->last_access_time);
 778         p = get_u64(p, &dentry->last_write_time);
 779
 780         p = get_bytes(p, WIM_HASH_SIZE, dentry->hash);
 781
 782         /*
 783          * I don't know what's going on here.  It seems like M$ screwed up the
 784          * reparse points, then put the fields in the same place and didn't
 785          * document it.  The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
 786          * have something to do with this, but it's not documented.
 787          */
 788         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 789                 /* ??? */
 790                 u32 u1, u2;
 791                 p = get_u32(p, &u1);
 792                 /*p += 4;*/
 793                 p = get_u32(p, &dentry->reparse_tag);
 794                 p = get_u32(p, &u2);
 795                 /*p += 4;*/
 796                 dentry->hard_link = (u64)(u1) | ((u64)(u2) << 32);
 797         } else {
 798                 p = get_u32(p, &dentry->reparse_tag);
 799                 p = get_u64(p, &dentry->hard_link);
 800         }
 801
 802         /* By the way, the reparse_reserved field does not actually exist (at
 803          * least when the file is not a reparse point) */
 804
 805
 806         p = get_u16(p, &dentry->num_ads);
 807
 808         p = get_u16(p, &short_name_len);
 809         p = get_u16(p, &file_name_len);
 810
 811         calculated_size = WIM_DENTRY_DISK_SIZE + file_name_len + 2 +
 812                           short_name_len;
 813
 814         if (dentry->length < calculated_size) {
 815                 ERROR("Unexpected end of directory entry! (Expected "
 816                       "%"PRIu64" bytes, got %"PRIu64" bytes. "
 817                       "short_name_len = %hu, file_name_len = %hu)",
 818                       calculated_size, dentry->length,
 819                       short_name_len, file_name_len);
 820                 return WIMLIB_ERR_INVALID_DENTRY;
 821         }
 822
 823         /* Read the filename. */
 824         file_name = MALLOC(file_name_len);
 825         if (!file_name) {
 826                 ERROR("Failed to allocate %hu bytes for dentry file name",
 827                       file_name_len);
 828                 return WIMLIB_ERR_NOMEM;
 829         }
 830         p = get_bytes(p, file_name_len, file_name);
 831
 832         /* Convert filename to UTF-8. */
 833         file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
 834                                        &file_name_utf8_len);
 835
 836         if (!file_name_utf8) {
 837                 ERROR("Failed to allocate memory to convert UTF-16 "
 838                       "filename (%hu bytes) to UTF-8", file_name_len);
 839                 ret = WIMLIB_ERR_NOMEM;
 840                 goto out_free_file_name;
 841         }
 842
 843         /* Undocumented padding between file name and short name.  This probably
 844          * is supposed to be a terminating null character. */
 845         p += 2;
 846
 847         /* Read the short filename. */
 848         short_name = MALLOC(short_name_len);
 849         if (!short_name) {
 850                 ERROR("Failed to allocate %hu bytes for short filename",
 851                       short_name_len);
 852                 ret = WIMLIB_ERR_NOMEM;
 853                 goto out_free_file_name_utf8;
 854         }
 855
 856         p = get_bytes(p, short_name_len, short_name);
 857
 858         /* Some directory entries inexplicibly have a little over 70 bytes of
 859          * extra data.  The exact amount of data seems to be 72 bytes, but it is
 860          * aligned on the next 8-byte boundary.  Here's an example of the
 861          * aligned data:
 862          *
 863          * 01000000400000006c786bbac58ede11b0bb00261870892ab6adb76fe63a3
 864          * e468fca86530d2effa16c786bbac58ede11b0bb00261870892a0000000000
 865          * 0000000000000000000000
 866          *
 867          * Here's one interpretation of how the data is laid out.
 868          *
 869          * struct unknown {
 870          *      u32 field1; (always 0x00000001)
 871          *      u32 field2; (always 0x40000000)
 872          *      u16 field3;
 873          *      u32 field4;
 874          *      u32 field5;
 875          *      u32 field6;
 876          *      u8  data[48]; (???)
 877          *      u64 reserved1; (always 0)
 878          *      u64 reserved2; (always 0)
 879          * };*/
 880 #if 0
 881         if (dentry->length - calculated_size >= WIM_ADS_ENTRY_DISK_SIZE) {
 882                 printf("%s: %lu / %lu (", file_name_utf8,
 883                                 calculated_size, dentry->length);
 884                 print_string(p + WIM_ADS_ENTRY_DISK_SIZE, dentry->length - calculated_size - WIM_ADS_ENTRY_DISK_SIZE);
 885                 puts(")");
 886                 print_byte_field(p, dentry->length - calculated_size);
 887                 putchar('\n');
 888         }
 889 #endif
 890
 891         if (dentry->num_ads != 0) {
 892                 calculated_size = (calculated_size + 7) & ~7;
 893                 if (calculated_size > metadata_resource_len - offset) {
 894                         ERROR("Not enough space in metadata resource for "
 895                               "alternate stream entries");
 896                         ret = WIMLIB_ERR_INVALID_DENTRY;
 897                         goto out_free_short_name;
 898                 }
 899                 ret = read_ads_entries(&metadata_resource[offset + calculated_size],
 900                                        dentry,
 901                                        metadata_resource_len - offset - calculated_size);
 902                 if (ret != 0)
 903                         goto out_free_short_name;
 904         }
 905
 906         dentry->file_name          = file_name;
 907         dentry->file_name_utf8     = file_name_utf8;
 908         dentry->short_name         = short_name;
 909         dentry->file_name_len      = file_name_len;
 910         dentry->file_name_utf8_len = file_name_utf8_len;
 911         dentry->short_name_len     = short_name_len;
 912         return 0;
 913 out_free_short_name:
 914         FREE(short_name);
 915 out_free_file_name_utf8:
 916         FREE(file_name_utf8);
 917 out_free_file_name:
 918         FREE(file_name);
 919         return ret;
 920 }
 921
 922 /*
 923  * Writes a dentry to an output buffer.
 924  *
 925  * @dentry:  The dentry structure.
 926  * @p:       The memory location to write the data to.
 927  * @return:  Pointer to the byte after the last byte we wrote as part of the
 928  *              dentry.
 929  */
 930 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
 931 {
 932         u8 *orig_p = p;
 933         memset(p, 0, dentry->length);
 934         p = put_u64(p, dentry->length);
 935         p = put_u32(p, dentry->attributes);
 936         p = put_u32(p, dentry->security_id);
 937         p = put_u64(p, dentry->subdir_offset);
 938         p = put_u64(p, 0); /* unused1 */
 939         p = put_u64(p, 0); /* unused2 */
 940         p = put_u64(p, dentry->creation_time);
 941         p = put_u64(p, dentry->last_access_time);
 942         p = put_u64(p, dentry->last_write_time);
 943         memcpy(p, dentry->hash, WIM_HASH_SIZE);
 944         p += WIM_HASH_SIZE;
 945         p = put_u32(p, dentry->reparse_tag);
 946         p = put_u64(p, dentry->hard_link);
 947         p = put_u16(p, dentry->num_ads); /*streams */
 948         p = put_u16(p, dentry->short_name_len);
 949         p = put_u16(p, dentry->file_name_len);
 950         p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
 951         p = put_u16(p, 0); /* filename padding, 2 bytes. */
 952         p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
 953         for (u16 i = 0; i < dentry->num_ads; i++) {
 954                 p = put_u64(p, ads_entry_length(&dentry->ads_entries[i]));
 955                 p = put_u64(p, 0); /* Unused */
 956                 p = put_bytes(p, WIM_HASH_SIZE, dentry->ads_entries[i].hash);
 957                 p = put_u16(p, dentry->ads_entries[i].stream_name_len);
 958                 p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
 959                                  (u8*)dentry->ads_entries[i].stream_name);
 960         }
 961         return orig_p + dentry->length;
 962 }
 963
 964 /* Recursive function that writes a dentry tree rooted at @tree, not including
 965  * @tree itself, which has already been written, except in the case of the root
 966  * dentry, which is written right away, along with an end-of-directory entry. */
 967 u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
 968 {
 969         const struct dentry *child;
 970
 971         if (dentry_is_root(tree)) {
 972                 p = write_dentry(tree, p);
 973
 974                 /* write end of directory entry */
 975                 p = put_u64(p, 0);
 976         } else {
 977                 /* Nothing to do for a regular file. */
 978                 if (dentry_is_regular_file(tree))
 979                         return p;
 980         }
 981
 982         /* Write child dentries and end-of-directory entry. */
 983         child = tree->children;
 984         if (child) {
 985                 do {
 986                         p = write_dentry(child, p);
 987                         child = child->next;
 988                 } while (child != tree->children);
 989         }
 990
 991         /* write end of directory entry */
 992         p = put_u64(p, 0);
 993
 994         /* Recurse on children. */
 995         if (child) {
 996                 do {
 997                         p = write_dentry_tree(child, p);
 998                         child = child->next;
 999                 } while (child != tree->children);
1000         }
1001         return p;
1002 }
1003
1004 /* Reads the children of a dentry, and all their children, ..., etc. from the
1005  * metadata resource and into the dentry tree.
1006  *
1007  * @metadata_resource:  An array that contains the uncompressed metadata
1008  *                      resource for the WIM file.
1009  * @metadata_resource_len:      The length of @metadata_resource.
1010  * @dentry:     A pointer to a struct dentry that is the root of the directory
1011  *              tree and has already been read from the metadata resource.  It
1012  *              does not need to be the real root because this procedure is
1013  *              called recursively.
1014  *
1015  * @return:     Zero on success, nonzero on failure.
1016  */
1017 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1018                      struct dentry *dentry)
1019 {
1020         u64 cur_offset = dentry->subdir_offset;
1021         struct dentry *prev_child = NULL;
1022         struct dentry *first_child = NULL;
1023         struct dentry *child;
1024         struct dentry cur_child;
1025         int ret;
1026
1027         /* If @dentry is a regular file, nothing more needs to be done for this
1028          * branch. */
1029         if (cur_offset == 0)
1030                 return 0;
1031
1032         /* Find and read all the children of @dentry. */
1033         while (1) {
1034
1035                 /* Read next child of @dentry into @cur_child. */
1036                 ret = read_dentry(metadata_resource, metadata_resource_len,
1037                                   cur_offset, &cur_child);
1038                 if (ret != 0)
1039                         break;
1040
1041                 /* Check for end of directory. */
1042                 if (cur_child.length == 0) {
1043                         ret = 0;
1044                         break;
1045                 }
1046
1047                 /* Not end of directory.  Allocate this child permanently and
1048                  * link it to the parent and previous child. */
1049                 child = MALLOC(sizeof(struct dentry));
1050                 if (!child) {
1051                         ERROR("Failed to allocate %zu bytes for new dentry",
1052                               sizeof(struct dentry));
1053                         ret = WIMLIB_ERR_NOMEM;
1054                         break;
1055                 }
1056                 memcpy(child, &cur_child, sizeof(struct dentry));
1057
1058                 if (prev_child) {
1059                         prev_child->next = child;
1060                         child->prev = prev_child;
1061                 } else {
1062                         first_child = child;
1063                 }
1064
1065                 child->parent = dentry;
1066                 prev_child = child;
1067
1068                 /* If there are children of this child, call this procedure
1069                  * recursively. */
1070                 if (child->subdir_offset != 0) {
1071                         ret = read_dentry_tree(metadata_resource,
1072                                                metadata_resource_len, child);
1073                         if (ret != 0)
1074                                 break;
1075                 }
1076
1077                 /* Advance to the offset of the next child. */
1078                 cur_offset += dentry_total_length(child);
1079         }
1080
1081         /* Link last child to first one, and set parent's
1082          * children pointer to the first child.  */
1083         if (prev_child) {
1084                 prev_child->next = first_child;
1085                 first_child->prev = prev_child;
1086         }
1087         dentry->children = first_child;
1088         return ret;
1089 }