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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 void 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         /* Use the size of the unnamed (default) file stream. */
  96         if (table && (lte = __lookup_resource(table, dentry_hash(dentry))))
  97                 stbuf->st_size = lte->resource_entry.original_size;
  98         else
  99                 stbuf->st_size = 0;
 100
 101         stbuf->st_nlink   = dentry_link_group_size(dentry);
 102         stbuf->st_ino     = dentry->hard_link;
 103         stbuf->st_uid     = getuid();
 104         stbuf->st_gid     = getgid();
 105         stbuf->st_atime   = ms_timestamp_to_unix(dentry->last_access_time);
 106         stbuf->st_mtime   = ms_timestamp_to_unix(dentry->last_write_time);
 107         stbuf->st_ctime   = ms_timestamp_to_unix(dentry->creation_time);
 108         stbuf->st_blocks  = (stbuf->st_size + 511) / 512;
 109 }
 110
 111 /* Makes all timestamp fields for the dentry be the current time. */
 112 void dentry_update_all_timestamps(struct dentry *dentry)
 113 {
 114         u64 now = get_timestamp();
 115         dentry->creation_time    = now;
 116         dentry->last_access_time = now;
 117         dentry->last_write_time  = now;
 118 }
 119
 120 struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
 121                                        const char *stream_name)
 122 {
 123         size_t stream_name_len = strlen(stream_name);
 124         if (!stream_name)
 125                 return NULL;
 126         for (u16 i = 0; i < dentry->num_ads; i++)
 127                 if (ads_entry_has_name(&dentry->ads_entries[i],
 128                                        stream_name, stream_name_len))
 129                         return &dentry->ads_entries[i];
 130         return NULL;
 131 }
 132
 133 /* Add an alternate stream entry to a dentry and return a pointer to it, or NULL
 134  * on failure. */
 135 struct ads_entry *dentry_add_ads(struct dentry *dentry, const char *stream_name)
 136 {
 137         u16 num_ads = dentry->num_ads + 1;
 138         struct ads_entry *ads_entries;
 139         struct ads_entry *new_entry;
 140         if (num_ads == 0xffff)
 141                 return NULL;
 142         ads_entries = MALLOC(num_ads * sizeof(struct ads_entry));
 143         if (!ads_entries)
 144                 return NULL;
 145
 146         new_entry = &ads_entries[num_ads - 1];
 147         if (change_ads_name(new_entry, stream_name) != 0) {
 148                 FREE(ads_entries);
 149                 return NULL;
 150         }
 151
 152         memcpy(ads_entries, dentry->ads_entries,
 153                (num_ads - 1) * sizeof(struct ads_entry));
 154         FREE(dentry->ads_entries);
 155         dentry->ads_entries = ads_entries;
 156         dentry->num_ads = num_ads;
 157         return memset(new_entry, 0, sizeof(struct ads_entry));
 158 }
 159
 160 void dentry_remove_ads(struct dentry *dentry, struct ads_entry *sentry)
 161 {
 162         destroy_ads_entry(sentry);
 163         memcpy(sentry, sentry + 1,
 164                (dentry->num_ads - (sentry - dentry->ads_entries))
 165                  * sizeof(struct ads_entry));
 166         dentry->num_ads--;
 167 }
 168
 169 /*
 170  * Calls a function on all directory entries in a directory tree.  It is called
 171  * on a parent before its children.
 172  */
 173 int for_dentry_in_tree(struct dentry *root,
 174                        int (*visitor)(struct dentry*, void*), void *arg)
 175 {
 176         int ret;
 177         struct dentry *child;
 178
 179         ret = visitor(root, arg);
 180
 181         if (ret != 0)
 182                 return ret;
 183
 184         child = root->children;
 185
 186         if (!child)
 187                 return 0;
 188
 189         do {
 190                 ret = for_dentry_in_tree(child, visitor, arg);
 191                 if (ret != 0)
 192                         return ret;
 193                 child = child->next;
 194         } while (child != root->children);
 195         return 0;
 196 }
 197
 198 /*
 199  * Like for_dentry_in_tree(), but the visitor function is always called on a
 200  * dentry's children before on itself.
 201  */
 202 int for_dentry_in_tree_depth(struct dentry *root,
 203                              int (*visitor)(struct dentry*, void*), void *arg)
 204 {
 205         int ret;
 206         struct dentry *child;
 207         struct dentry *next;
 208
 209         child = root->children;
 210         if (child) {
 211                 do {
 212                         next = child->next;
 213                         ret = for_dentry_in_tree_depth(child, visitor, arg);
 214                         if (ret != 0)
 215                                 return ret;
 216                         child = next;
 217                 } while (child != root->children);
 218         }
 219         return visitor(root, arg);
 220 }
 221
 222 /*
 223  * Calculate the full path of @dentry, based on its parent's full path and on
 224  * its UTF-8 file name.
 225  */
 226 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
 227 {
 228         char *full_path;
 229         u32 full_path_len;
 230         if (dentry_is_root(dentry)) {
 231                 full_path = MALLOC(2);
 232                 if (!full_path)
 233                         goto oom;
 234                 full_path[0] = '/';
 235                 full_path[1] = '\0';
 236                 full_path_len = 1;
 237         } else {
 238                 char *parent_full_path;
 239                 u32 parent_full_path_len;
 240                 const struct dentry *parent = dentry->parent;
 241
 242                 if (dentry_is_root(parent)) {
 243                         parent_full_path = "";
 244                         parent_full_path_len = 0;
 245                 } else {
 246                         parent_full_path = parent->full_path_utf8;
 247                         parent_full_path_len = parent->full_path_utf8_len;
 248                 }
 249
 250                 full_path_len = parent_full_path_len + 1 +
 251                                 dentry->file_name_utf8_len;
 252                 full_path = MALLOC(full_path_len + 1);
 253                 if (!full_path)
 254                         goto oom;
 255
 256                 memcpy(full_path, parent_full_path, parent_full_path_len);
 257                 full_path[parent_full_path_len] = '/';
 258                 memcpy(full_path + parent_full_path_len + 1,
 259                        dentry->file_name_utf8,
 260                        dentry->file_name_utf8_len);
 261                 full_path[full_path_len] = '\0';
 262         }
 263         FREE(dentry->full_path_utf8);
 264         dentry->full_path_utf8 = full_path;
 265         dentry->full_path_utf8_len = full_path_len;
 266         return 0;
 267 oom:
 268         ERROR("Out of memory while calculating dentry full path");
 269         return WIMLIB_ERR_NOMEM;
 270 }
 271
 272 /*
 273  * Recursively calculates the subdir offsets for a directory tree.
 274  *
 275  * @dentry:  The root of the directory tree.
 276  * @subdir_offset_p:  The current subdirectory offset; i.e., the subdirectory
 277  *      offset for @dentry.
 278  */
 279 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 280 {
 281         struct dentry *child;
 282
 283         child = dentry->children;
 284         dentry->subdir_offset = *subdir_offset_p;
 285         if (child) {
 286
 287                 /* Advance the subdir offset by the amount of space the children
 288                  * of this dentry take up. */
 289                 do {
 290                         *subdir_offset_p += dentry_total_length(child);
 291                         child = child->next;
 292                 } while (child != dentry->children);
 293
 294                 /* End-of-directory dentry on disk. */
 295                 *subdir_offset_p += 8;
 296
 297                 /* Recursively call calculate_subdir_offsets() on all the
 298                  * children. */
 299                 do {
 300                         calculate_subdir_offsets(child, subdir_offset_p);
 301                         child = child->next;
 302                 } while (child != dentry->children);
 303         } else {
 304                 /* On disk, childless directories have a valid subdir_offset
 305                  * that points to an 8-byte end-of-directory dentry.  Regular
 306                  * files have a subdir_offset of 0. */
 307                 if (dentry_is_directory(dentry))
 308                         *subdir_offset_p += 8;
 309                 else
 310                         dentry->subdir_offset = 0;
 311         }
 312 }
 313
 314
 315 /* Returns the child of @dentry that has the file name @name.
 316  * Returns NULL if no child has the name. */
 317 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
 318                                                         const char *name)
 319 {
 320         struct dentry *child;
 321         size_t name_len;
 322
 323         child = dentry->children;
 324         if (child) {
 325                 name_len = strlen(name);
 326                 do {
 327                         if (dentry_has_name(child, name, name_len))
 328                                 return child;
 329                         child = child->next;
 330                 } while (child != dentry->children);
 331         }
 332         return NULL;
 333 }
 334
 335 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
 336  * @cur_dir.  Returns NULL if no dentry having the path is found. */
 337 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir, const char *path)
 338 {
 339         struct dentry *child;
 340         size_t base_len;
 341         const char *new_path;
 342
 343         if (*path == '\0')
 344                 return cur_dir;
 345
 346         child = cur_dir->children;
 347         if (child) {
 348                 new_path = path_next_part(path, &base_len);
 349                 do {
 350                         if (dentry_has_name(child, path, base_len))
 351                                 return get_dentry_relative_path(child, new_path);
 352                         child = child->next;
 353                 } while (child != cur_dir->children);
 354         }
 355         return NULL;
 356 }
 357
 358 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
 359  * such dentry. */
 360 struct dentry *get_dentry(WIMStruct *w, const char *path)
 361 {
 362         struct dentry *root = wim_root_dentry(w);
 363         while (*path == '/')
 364                 path++;
 365         return get_dentry_relative_path(root, path);
 366 }
 367
 368 /* Returns the parent directory for the @path. */
 369 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
 370 {
 371         size_t path_len = strlen(path);
 372         char buf[path_len + 1];
 373
 374         memcpy(buf, path, path_len + 1);
 375
 376         to_parent_name(buf, path_len);
 377
 378         return get_dentry(w, buf);
 379 }
 380
 381 /* Prints the full path of a dentry. */
 382 int print_dentry_full_path(struct dentry *dentry, void *ignore)
 383 {
 384         if (dentry->full_path_utf8)
 385                 puts(dentry->full_path_utf8);
 386         return 0;
 387 }
 388
 389 struct file_attr_flag {
 390         u32 flag;
 391         const char *name;
 392 };
 393 struct file_attr_flag file_attr_flags[] = {
 394         {FILE_ATTRIBUTE_READONLY,               "READONLY"},
 395         {FILE_ATTRIBUTE_HIDDEN,         "HIDDEN"},
 396         {FILE_ATTRIBUTE_SYSTEM,         "SYSTEM"},
 397         {FILE_ATTRIBUTE_DIRECTORY,              "DIRECTORY"},
 398         {FILE_ATTRIBUTE_ARCHIVE,                "ARCHIVE"},
 399         {FILE_ATTRIBUTE_DEVICE,         "DEVICE"},
 400         {FILE_ATTRIBUTE_NORMAL,         "NORMAL"},
 401         {FILE_ATTRIBUTE_TEMPORARY,              "TEMPORARY"},
 402         {FILE_ATTRIBUTE_SPARSE_FILE,    "SPARSE_FILE"},
 403         {FILE_ATTRIBUTE_REPARSE_POINT,  "REPARSE_POINT"},
 404         {FILE_ATTRIBUTE_COMPRESSED,             "COMPRESSED"},
 405         {FILE_ATTRIBUTE_OFFLINE,                "OFFLINE"},
 406         {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
 407         {FILE_ATTRIBUTE_ENCRYPTED,              "ENCRYPTED"},
 408         {FILE_ATTRIBUTE_VIRTUAL,                "VIRTUAL"},
 409 };
 410
 411 /* Prints a directory entry.  @lookup_table is a pointer to the lookup table, or
 412  * NULL if the resource entry for the dentry is not to be printed. */
 413 int print_dentry(struct dentry *dentry, void *lookup_table)
 414 {
 415         struct lookup_table_entry *lte;
 416         unsigned i;
 417
 418         printf("[DENTRY]\n");
 419         printf("Length            = %"PRIu64"\n", dentry->length);
 420         printf("Attributes        = 0x%x\n", dentry->attributes);
 421         for (i = 0; i < ARRAY_LEN(file_attr_flags); i++)
 422                 if (file_attr_flags[i].flag & dentry->attributes)
 423                         printf("    FILE_ATTRIBUTE_%s is set\n",
 424                                 file_attr_flags[i].name);
 425         printf("Security ID       = %d\n", dentry->security_id);
 426         printf("Subdir offset     = %"PRIu64"\n", dentry->subdir_offset);
 427         /*printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);*/
 428         /*printf("Unused2           = %"PRIu64"\n", dentry->unused2);*/
 429         printf("Creation Time     = 0x%"PRIx64"\n", dentry->creation_time);
 430         printf("Last Access Time  = 0x%"PRIx64"\n", dentry->last_access_time);
 431         printf("Last Write Time   = 0x%"PRIx64"\n", dentry->last_write_time);
 432         printf("Hash              = 0x");
 433         print_hash(dentry->hash);
 434         putchar('\n');
 435         printf("Reparse Tag       = 0x%"PRIx32"\n", dentry->reparse_tag);
 436         printf("Hard Link Group   = 0x%"PRIx64"\n", dentry->hard_link);
 437         printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
 438         printf("Filename          = \"");
 439         print_string(dentry->file_name, dentry->file_name_len);
 440         puts("\"");
 441         printf("Filename Length   = %hu\n", dentry->file_name_len);
 442         printf("Filename (UTF-8)  = \"%s\"\n", dentry->file_name_utf8);
 443         printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
 444         printf("Short Name        = \"");
 445         print_string(dentry->short_name, dentry->short_name_len);
 446         puts("\"");
 447         printf("Short Name Length = %hu\n", dentry->short_name_len);
 448         printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
 449         if (lookup_table && (lte = __lookup_resource(lookup_table, dentry->hash)))
 450                 print_lookup_table_entry(lte, NULL);
 451         else
 452                 putchar('\n');
 453         for (u16 i = 0; i < dentry->num_ads; i++) {
 454                 printf("[Alternate Stream Entry %u]\n", i);
 455                 printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
 456                 printf("Name Length (UTF-16) = %u\n",
 457                                 dentry->ads_entries[i].stream_name_len);
 458                 printf("Hash              = 0x");
 459                 print_hash(dentry->ads_entries[i].hash);
 460                 if (lookup_table &&
 461                      (lte = __lookup_resource(lookup_table,
 462                                               dentry->ads_entries[i].hash)))
 463                 {
 464                         print_lookup_table_entry(lte, NULL);
 465                 } else {
 466                         putchar('\n');
 467                 }
 468         }
 469         return 0;
 470 }
 471
 472 static inline void dentry_common_init(struct dentry *dentry)
 473 {
 474         memset(dentry, 0, sizeof(struct dentry));
 475         dentry->refcnt = 1;
 476         dentry->security_id = -1;
 477 }
 478
 479 /*
 480  * Creates an unlinked directory entry.
 481  *
 482  * @name:    The base name of the new dentry.
 483  * @return:  A pointer to the new dentry, or NULL if out of memory.
 484  */
 485 struct dentry *new_dentry(const char *name)
 486 {
 487         struct dentry *dentry;
 488
 489         dentry = MALLOC(sizeof(struct dentry));
 490         if (!dentry)
 491                 goto err;
 492
 493         dentry_common_init(dentry);
 494         if (change_dentry_name(dentry, name) != 0)
 495                 goto err;
 496
 497         dentry_update_all_timestamps(dentry);
 498         dentry->next   = dentry;
 499         dentry->prev   = dentry;
 500         dentry->parent = dentry;
 501         return dentry;
 502 err:
 503         FREE(dentry);
 504         ERROR("Failed to allocate new dentry");
 505         return NULL;
 506 }
 507
 508 void dentry_free_ads_entries(struct dentry *dentry)
 509 {
 510         for (u16 i = 0; i < dentry->num_ads; i++)
 511                 destroy_ads_entry(&dentry->ads_entries[i]);
 512         FREE(dentry->ads_entries);
 513         dentry->ads_entries = NULL;
 514         dentry->num_ads = 0;
 515 }
 516
 517
 518 void free_dentry(struct dentry *dentry)
 519 {
 520         FREE(dentry->file_name);
 521         FREE(dentry->file_name_utf8);
 522         FREE(dentry->short_name);
 523         FREE(dentry->full_path_utf8);
 524         dentry_free_ads_entries(dentry);
 525         FREE(dentry);
 526 }
 527
 528 /* clones a dentry.
 529  *
 530  * Beware:
 531  *      - memory for file names is not cloned
 532  *      - next, prev, and children pointers and not touched
 533  *      - stream entries are not cloned.
 534  */
 535 struct dentry *clone_dentry(struct dentry *old)
 536 {
 537         struct dentry *new = MALLOC(sizeof(struct dentry));
 538         if (!new)
 539                 return NULL;
 540         memcpy(new, old, sizeof(struct dentry));
 541         new->file_name          = NULL;
 542         new->file_name_len      = 0;
 543         new->file_name_utf8     = NULL;
 544         new->file_name_utf8_len = 0;
 545         new->short_name         = NULL;
 546         new->short_name_len     = 0;
 547         return new;
 548 }
 549
 550 /* Arguments for do_free_dentry(). */
 551 struct free_dentry_args {
 552         struct lookup_table *lookup_table;
 553         bool lt_decrement_refcnt;
 554 };
 555
 556 /*
 557  * This function is passed as an argument to for_dentry_in_tree_depth() in order
 558  * to free a directory tree.  __args is a pointer to a `struct free_dentry_args'.
 559  */
 560 static int do_free_dentry(struct dentry *dentry, void *__args)
 561 {
 562         struct free_dentry_args *args = (struct free_dentry_args*)__args;
 563
 564         if (args->lt_decrement_refcnt && !dentry_is_directory(dentry)) {
 565                 lookup_table_decrement_refcnt(args->lookup_table,
 566                                               dentry->hash);
 567         }
 568
 569         wimlib_assert(dentry->refcnt >= 1);
 570         if (--dentry->refcnt == 0)
 571                 free_dentry(dentry);
 572         return 0;
 573 }
 574
 575 /*
 576  * Unlinks and frees a dentry tree.
 577  *
 578  * @root:               The root of the tree.
 579  * @lookup_table:       The lookup table for dentries.
 580  * @decrement_refcnt:   True if the dentries in the tree are to have their
 581  *                      reference counts in the lookup table decremented.
 582  */
 583 void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table,
 584                       bool lt_decrement_refcnt)
 585 {
 586         if (!root || !root->parent)
 587                 return;
 588
 589         struct free_dentry_args args;
 590         args.lookup_table        = lookup_table;
 591         args.lt_decrement_refcnt = lt_decrement_refcnt;
 592         for_dentry_in_tree_depth(root, do_free_dentry, &args);
 593 }
 594
 595 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
 596 {
 597         dentry->refcnt++;
 598         return 0;
 599 }
 600
 601 /*
 602  * Links a dentry into the directory tree.
 603  *
 604  * @dentry: The dentry to link.
 605  * @parent: The dentry that will be the parent of @dentry.
 606  */
 607 void link_dentry(struct dentry *dentry, struct dentry *parent)
 608 {
 609         dentry->parent = parent;
 610         if (parent->children) {
 611                 /* Not an only child; link to siblings. */
 612                 dentry->next = parent->children;
 613                 dentry->prev = parent->children->prev;
 614                 dentry->next->prev = dentry;
 615                 dentry->prev->next = dentry;
 616         } else {
 617                 /* Only child; link to parent. */
 618                 parent->children = dentry;
 619                 dentry->next = dentry;
 620                 dentry->prev = dentry;
 621         }
 622 }
 623
 624 /* Unlink a dentry from the directory tree. */
 625 void unlink_dentry(struct dentry *dentry)
 626 {
 627         if (dentry_is_root(dentry))
 628                 return;
 629         if (dentry_is_only_child(dentry)) {
 630                 dentry->parent->children = NULL;
 631         } else {
 632                 if (dentry_is_first_sibling(dentry))
 633                         dentry->parent->children = dentry->next;
 634                 dentry->next->prev = dentry->prev;
 635                 dentry->prev->next = dentry->next;
 636         }
 637 }
 638
 639
 640 /* Recalculates the length of @dentry based on its file name length and short
 641  * name length.  */
 642 static inline void recalculate_dentry_size(struct dentry *dentry)
 643 {
 644         dentry->length = WIM_DENTRY_DISK_SIZE + dentry->file_name_len +
 645                          2 + dentry->short_name_len;
 646         /* Must be multiple of 8. */
 647         dentry->length = (dentry->length + 7) & ~7;
 648 }
 649
 650 static int do_name_change(char **file_name_ret,
 651                           char **file_name_utf8_ret,
 652                           u16 *file_name_len_ret,
 653                           u16 *file_name_utf8_len_ret,
 654                           const char *new_name)
 655 {
 656         size_t utf8_len;
 657         size_t utf16_len;
 658         char *file_name, *file_name_utf8;
 659
 660         utf8_len = strlen(new_name);
 661
 662         file_name = utf8_to_utf16(new_name, utf8_len, &utf16_len);
 663
 664         if (!file_name)
 665                 return WIMLIB_ERR_NOMEM;
 666
 667         file_name_utf8 = MALLOC(utf8_len + 1);
 668         if (!file_name_utf8) {
 669                 FREE(file_name);
 670                 return WIMLIB_ERR_NOMEM;
 671         }
 672         memcpy(file_name_utf8, new_name, utf8_len + 1);
 673
 674         FREE(*file_name_ret);
 675         FREE(*file_name_utf8_ret);
 676         *file_name_ret          = file_name;
 677         *file_name_utf8_ret     = file_name_utf8;
 678         *file_name_len_ret      = utf16_len;
 679         *file_name_utf8_len_ret = utf8_len;
 680         return 0;
 681 }
 682
 683 /* Changes the name of a dentry to @new_name.  Only changes the file_name and
 684  * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
 685  * full_path_utf8 fields.  Also recalculates its length. */
 686 int change_dentry_name(struct dentry *dentry, const char *new_name)
 687 {
 688         int ret;
 689
 690         ret = do_name_change(&dentry->file_name, &dentry->file_name_utf8,
 691                              &dentry->file_name_len, &dentry->file_name_utf8_len,
 692                              new_name);
 693         if (ret == 0)
 694                 recalculate_dentry_size(dentry);
 695         return ret;
 696 }
 697
 698 int change_ads_name(struct ads_entry *entry, const char *new_name)
 699 {
 700         return do_name_change(&entry->stream_name, &entry->stream_name_utf8,
 701                               &entry->stream_name_len,
 702                               &entry->stream_name_utf8_len,
 703                               new_name);
 704 }
 705
 706 /* Parameters for calculate_dentry_statistics(). */
 707 struct image_statistics {
 708         struct lookup_table *lookup_table;
 709         u64 *dir_count;
 710         u64 *file_count;
 711         u64 *total_bytes;
 712         u64 *hard_link_bytes;
 713 };
 714
 715 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
 716 {
 717         struct image_statistics *stats;
 718         struct lookup_table_entry *lte;
 719         u16 i;
 720
 721         stats = arg;
 722
 723         if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
 724                 ++*stats->dir_count;
 725         else
 726                 ++*stats->file_count;
 727
 728         lte = __lookup_resource(stats->lookup_table, dentry->hash);
 729         i = 0;
 730         while (1) {
 731                 if (lte) {
 732                         u64 size = lte->resource_entry.original_size;
 733                         *stats->total_bytes += size;
 734                         if (++lte->out_refcnt == 1)
 735                                 *stats->hard_link_bytes += size;
 736                 }
 737                 if (i == dentry->num_ads)
 738                         break;
 739                 lte = __lookup_resource(stats->lookup_table,
 740                                         dentry->ads_entries[i].hash);
 741                 i++;
 742         }
 743
 744         return 0;
 745 }
 746
 747 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
 748                                    u64 *dir_count_ret, u64 *file_count_ret,
 749                                    u64 *total_bytes_ret,
 750                                    u64 *hard_link_bytes_ret)
 751 {
 752         struct image_statistics stats;
 753         *dir_count_ret         = 0;
 754         *file_count_ret        = 0;
 755         *total_bytes_ret       = 0;
 756         *hard_link_bytes_ret   = 0;
 757         stats.lookup_table     = table;
 758         stats.dir_count       = dir_count_ret;
 759         stats.file_count      = file_count_ret;
 760         stats.total_bytes     = total_bytes_ret;
 761         stats.hard_link_bytes = hard_link_bytes_ret;
 762         for_lookup_table_entry(table, zero_out_refcnts, NULL);
 763         for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
 764 }
 765
 766 static int read_ads_entries(const u8 *p, struct dentry *dentry,
 767                             u64 remaining_size)
 768 {
 769         u16 num_ads = dentry->num_ads;
 770         struct ads_entry *ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
 771         int ret;
 772         if (!ads_entries) {
 773                 ERROR("Could not allocate memory for %"PRIu16" "
 774                       "alternate data stream entries", num_ads);
 775                 return WIMLIB_ERR_NOMEM;
 776         }
 777         DEBUG2("Reading %"PRIu16" alternate data streams "
 778                "(remaining size = %"PRIu64")", num_ads, remaining_size);
 779
 780         for (u16 i = 0; i < num_ads; i++) {
 781                 struct ads_entry *cur_entry = &ads_entries[i];
 782                 u64 length;
 783                 size_t utf8_len;
 784                 const char *p_save = p;
 785                 /* Read the base stream entry, excluding the stream name. */
 786                 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
 787                         ERROR("Stream entries go past end of metadata resource");
 788                         ERROR("(remaining_size = %"PRIu64")", remaining_size);
 789                         ret = WIMLIB_ERR_INVALID_DENTRY;
 790                         goto out_free_ads_entries;
 791                 }
 792                 remaining_size -= WIM_ADS_ENTRY_DISK_SIZE;
 793
 794                 p = get_u64(p, &length); /* ADS entry length */
 795
 796                 DEBUG2("ADS length = %"PRIu64, length);
 797
 798                 p += 8; /* Unused */
 799                 p = get_bytes(p, WIM_HASH_SIZE, (u8*)cur_entry->hash);
 800                 p = get_u16(p, &cur_entry->stream_name_len);
 801
 802                 DEBUG2("Stream name length = %u", cur_entry->stream_name_len);
 803
 804                 cur_entry->stream_name = NULL;
 805                 cur_entry->stream_name_utf8 = NULL;
 806
 807                 if (remaining_size < cur_entry->stream_name_len + 2) {
 808                         ERROR("Stream entries go past end of metadata resource");
 809                         ERROR("(remaining_size = %"PRIu64" bytes, stream_name_len "
 810                               "= %"PRIu16" bytes", remaining_size,
 811                               cur_entry->stream_name_len);
 812                         ret = WIMLIB_ERR_INVALID_DENTRY;
 813                         goto out_free_ads_entries;
 814                 }
 815                 remaining_size -= cur_entry->stream_name_len + 2;
 816
 817                 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
 818                 if (!cur_entry->stream_name) {
 819                         ret = WIMLIB_ERR_NOMEM;
 820                         goto out_free_ads_entries;
 821                 }
 822                 get_bytes(p, cur_entry->stream_name_len,
 823                           (u8*)cur_entry->stream_name);
 824                 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
 825                                                             cur_entry->stream_name_len,
 826                                                             &utf8_len);
 827                 cur_entry->stream_name_utf8_len = utf8_len;
 828
 829                 if (!cur_entry->stream_name_utf8) {
 830                         ret = WIMLIB_ERR_NOMEM;
 831                         goto out_free_ads_entries;
 832                 }
 833                 p = p_save + ads_entry_length(cur_entry);
 834         }
 835         dentry->ads_entries = ads_entries;
 836         return 0;
 837 out_free_ads_entries:
 838         for (u16 i = 0; i < num_ads; i++) {
 839                 FREE(ads_entries[i].stream_name);
 840                 FREE(ads_entries[i].stream_name_utf8);
 841         }
 842         FREE(ads_entries);
 843         return ret;
 844 }
 845
 846 /*
 847  * Reads a directory entry from the metadata resource.
 848  */
 849 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
 850                 u64 offset, struct dentry *dentry)
 851 {
 852         const u8 *p;
 853         u64 calculated_size;
 854         char *file_name;
 855         char *file_name_utf8;
 856         char *short_name;
 857         u16 short_name_len;
 858         u16 file_name_len;
 859         size_t file_name_utf8_len;
 860         int ret;
 861
 862         dentry_common_init(dentry);
 863
 864         /*Make sure the dentry really fits into the metadata resource.*/
 865         if (offset + 8 > metadata_resource_len) {
 866                 ERROR("Directory entry starting at %"PRIu64" ends past the "
 867                       "end of the metadata resource (size %"PRIu64")",
 868                       offset, metadata_resource_len);
 869                 return WIMLIB_ERR_INVALID_DENTRY;
 870         }
 871
 872         /* Before reading the whole entry, we need to read just the length.
 873          * This is because an entry of length 8 (that is, just the length field)
 874          * terminates the list of sibling directory entries. */
 875
 876         p = get_u64(&metadata_resource[offset], &dentry->length);
 877
 878         /* A zero length field (really a length of 8, since that's how big the
 879          * directory entry is...) indicates that this is the end of directory
 880          * dentry.  We do not read it into memory as an actual dentry, so just
 881          * return true in that case. */
 882         if (dentry->length == 0)
 883                 return 0;
 884
 885         if (offset + dentry->length >= metadata_resource_len) {
 886                 ERROR("Directory entry at offset %"PRIu64" and with size "
 887                       "%"PRIu64" ends past the end of the metadata resource "
 888                       "(size %"PRIu64")",
 889                       offset, dentry->length, metadata_resource_len);
 890                 return WIMLIB_ERR_INVALID_DENTRY;
 891         }
 892
 893         /* If it is a recognized length, read the rest of the directory entry.
 894          * Note: The root directory entry has no name, and its length does not
 895          * include the short name length field.  */
 896         if (dentry->length < WIM_DENTRY_DISK_SIZE) {
 897                 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
 898                       dentry->length);
 899                 return WIMLIB_ERR_INVALID_DENTRY;
 900         }
 901
 902         p = get_u32(p, &dentry->attributes);
 903         p = get_u32(p, (u32*)&dentry->security_id);
 904         p = get_u64(p, &dentry->subdir_offset);
 905
 906         /* 2 unused fields */
 907         p += 2 * sizeof(u64);
 908         /*p = get_u64(p, &dentry->unused1);*/
 909         /*p = get_u64(p, &dentry->unused2);*/
 910
 911         p = get_u64(p, &dentry->creation_time);
 912         p = get_u64(p, &dentry->last_access_time);
 913         p = get_u64(p, &dentry->last_write_time);
 914
 915         p = get_bytes(p, WIM_HASH_SIZE, dentry->hash);
 916
 917         /*
 918          * I don't know what's going on here.  It seems like M$ screwed up the
 919          * reparse points, then put the fields in the same place and didn't
 920          * document it.  The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
 921          * have something to do with this, but it's not documented.
 922          */
 923         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 924                 /* ??? */
 925                 p += 4;
 926                 p = get_u32(p, &dentry->reparse_tag);
 927                 p += 4;
 928         } else {
 929                 p = get_u32(p, &dentry->reparse_tag);
 930                 p = get_u64(p, &dentry->hard_link);
 931         }
 932
 933         /* By the way, the reparse_reserved field does not actually exist (at
 934          * least when the file is not a reparse point) */
 935
 936
 937         p = get_u16(p, &dentry->num_ads);
 938
 939         p = get_u16(p, &short_name_len);
 940         p = get_u16(p, &file_name_len);
 941
 942         calculated_size = WIM_DENTRY_DISK_SIZE + file_name_len + 2 +
 943                           short_name_len;
 944
 945         if (dentry->length < calculated_size) {
 946                 ERROR("Unexpected end of directory entry! (Expected "
 947                       "%"PRIu64" bytes, got %"PRIu64" bytes. "
 948                       "short_name_len = %hu, file_name_len = %hu)",
 949                       calculated_size, dentry->length,
 950                       short_name_len, file_name_len);
 951                 return WIMLIB_ERR_INVALID_DENTRY;
 952         }
 953
 954         /* Read the filename. */
 955         file_name = MALLOC(file_name_len);
 956         if (!file_name) {
 957                 ERROR("Failed to allocate %hu bytes for dentry file name",
 958                       file_name_len);
 959                 return WIMLIB_ERR_NOMEM;
 960         }
 961         p = get_bytes(p, file_name_len, file_name);
 962
 963         /* Convert filename to UTF-8. */
 964         file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
 965                                        &file_name_utf8_len);
 966
 967         if (!file_name_utf8) {
 968                 ERROR("Failed to allocate memory to convert UTF-16 "
 969                       "filename (%hu bytes) to UTF-8", file_name_len);
 970                 ret = WIMLIB_ERR_NOMEM;
 971                 goto out_free_file_name;
 972         }
 973
 974         /* Undocumented padding between file name and short name.  This probably
 975          * is supposed to be a terminating null character. */
 976         p += 2;
 977
 978         /* Read the short filename. */
 979         short_name = MALLOC(short_name_len);
 980         if (!short_name) {
 981                 ERROR("Failed to allocate %hu bytes for short filename",
 982                       short_name_len);
 983                 ret = WIMLIB_ERR_NOMEM;
 984                 goto out_free_file_name_utf8;
 985         }
 986
 987         p = get_bytes(p, short_name_len, short_name);
 988
 989         /* Some directory entries inexplicibly have a little over 70 bytes of
 990          * extra data.  The exact amount of data seems to be 72 bytes, but it is
 991          * aligned on the next 8-byte boundary.  Here's an example of the
 992          * aligned data:
 993          *
 994          * 01000000400000006c786bbac58ede11b0bb00261870892ab6adb76fe63a3
 995          * e468fca86530d2effa16c786bbac58ede11b0bb00261870892a0000000000
 996          * 0000000000000000000000
 997          *
 998          * Here's one interpretation of how the data is laid out.
 999          *
1000          * struct unknown {
1001          *      u32 field1; (always 0x00000001)
1002          *      u32 field2; (always 0x40000000)
1003          *      u16 field3;
1004          *      u32 field4;
1005          *      u32 field5;
1006          *      u32 field6;
1007          *      u8  data[48]; (???)
1008          *      u64 reserved1; (always 0)
1009          *      u64 reserved2; (always 0)
1010          * };*/
1011 #if 0
1012         if (dentry->length - calculated_size >= WIM_ADS_ENTRY_DISK_SIZE) {
1013                 printf("%s: %lu / %lu (", file_name_utf8,
1014                                 calculated_size, dentry->length);
1015                 print_string(p + WIM_ADS_ENTRY_DISK_SIZE, dentry->length - calculated_size - WIM_ADS_ENTRY_DISK_SIZE);
1016                 puts(")");
1017                 print_byte_field(p, dentry->length - calculated_size);
1018                 putchar('\n');
1019         }
1020 #endif
1021
1022         if (dentry->num_ads != 0) {
1023                 calculated_size = (calculated_size + 7) & ~7;
1024                 if (calculated_size > metadata_resource_len - offset) {
1025                         ERROR("Not enough space in metadata resource for "
1026                               "alternate stream entries");
1027                         ret = WIMLIB_ERR_INVALID_DENTRY;
1028                         goto out_free_short_name;
1029                 }
1030                 ret = read_ads_entries(&metadata_resource[offset + calculated_size],
1031                                        dentry,
1032                                        metadata_resource_len - offset - calculated_size);
1033                 if (ret != 0)
1034                         goto out_free_short_name;
1035         }
1036
1037         dentry->file_name          = file_name;
1038         dentry->file_name_utf8     = file_name_utf8;
1039         dentry->short_name         = short_name;
1040         dentry->file_name_len      = file_name_len;
1041         dentry->file_name_utf8_len = file_name_utf8_len;
1042         dentry->short_name_len     = short_name_len;
1043         return 0;
1044 out_free_short_name:
1045         FREE(short_name);
1046 out_free_file_name_utf8:
1047         FREE(file_name_utf8);
1048 out_free_file_name:
1049         FREE(file_name);
1050         return ret;
1051 }
1052
1053 /*
1054  * Writes a dentry to an output buffer.
1055  *
1056  * @dentry:  The dentry structure.
1057  * @p:       The memory location to write the data to.
1058  * @return:  Pointer to the byte after the last byte we wrote as part of the
1059  *              dentry.
1060  */
1061 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
1062 {
1063         u8 *orig_p = p;
1064         unsigned padding;
1065
1066         p = put_u64(p, dentry->length);
1067         p = put_u32(p, dentry->attributes);
1068         p = put_u32(p, dentry->security_id);
1069         p = put_u64(p, dentry->subdir_offset);
1070         p = put_u64(p, 0); /* unused1 */
1071         p = put_u64(p, 0); /* unused2 */
1072         p = put_u64(p, dentry->creation_time);
1073         p = put_u64(p, dentry->last_access_time);
1074         p = put_u64(p, dentry->last_write_time);
1075         p = put_bytes(p, WIM_HASH_SIZE, dentry->hash);
1076         if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1077                 p = put_zeroes(p, 4);
1078                 p = put_u32(p, dentry->reparse_tag);
1079                 p = put_zeroes(p, 4);
1080         } else {
1081                 p = put_u32(p, dentry->reparse_tag);
1082                 p = put_u64(p, dentry->hard_link);
1083         }
1084         p = put_u16(p, dentry->num_ads);
1085         p = put_u16(p, dentry->short_name_len);
1086         p = put_u16(p, dentry->file_name_len);
1087         p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
1088         p = put_u16(p, 0); /* filename padding, 2 bytes. */
1089         p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
1090
1091         wimlib_assert(p - orig_p <= dentry->length);
1092         if (p - orig_p < dentry->length)
1093                 p = put_zeroes(p, dentry->length - (p - orig_p));
1094
1095         p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1096
1097         for (u16 i = 0; i < dentry->num_ads; i++) {
1098                 p = put_u64(p, ads_entry_length(&dentry->ads_entries[i]));
1099                 p = put_u64(p, 0); /* Unused */
1100                 p = put_bytes(p, WIM_HASH_SIZE, dentry->ads_entries[i].hash);
1101                 p = put_u16(p, dentry->ads_entries[i].stream_name_len);
1102                 p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
1103                                  (u8*)dentry->ads_entries[i].stream_name);
1104                 p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1105         }
1106         return p;
1107 }
1108
1109 /* Recursive function that writes a dentry tree rooted at @tree, not including
1110  * @tree itself, which has already been written, except in the case of the root
1111  * dentry, which is written right away, along with an end-of-directory entry. */
1112 u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
1113 {
1114         const struct dentry *child;
1115
1116         if (dentry_is_root(tree)) {
1117                 p = write_dentry(tree, p);
1118
1119                 /* write end of directory entry */
1120                 p = put_u64(p, 0);
1121         } else {
1122                 /* Nothing to do for non-directories */
1123                 if (!dentry_is_directory(tree))
1124                         return p;
1125         }
1126
1127         /* Write child dentries and end-of-directory entry. */
1128         child = tree->children;
1129         if (child) {
1130                 do {
1131                         p = write_dentry(child, p);
1132                         child = child->next;
1133                 } while (child != tree->children);
1134         }
1135
1136         /* write end of directory entry */
1137         p = put_u64(p, 0);
1138
1139         /* Recurse on children. */
1140         if (child) {
1141                 do {
1142                         p = write_dentry_tree(child, p);
1143                         child = child->next;
1144                 } while (child != tree->children);
1145         }
1146         return p;
1147 }
1148
1149 /* Reads the children of a dentry, and all their children, ..., etc. from the
1150  * metadata resource and into the dentry tree.
1151  *
1152  * @metadata_resource:  An array that contains the uncompressed metadata
1153  *                      resource for the WIM file.
1154  * @metadata_resource_len:      The length of @metadata_resource.
1155  * @dentry:     A pointer to a struct dentry that is the root of the directory
1156  *              tree and has already been read from the metadata resource.  It
1157  *              does not need to be the real root because this procedure is
1158  *              called recursively.
1159  *
1160  * @return:     Zero on success, nonzero on failure.
1161  */
1162 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1163                      struct dentry *dentry)
1164 {
1165         u64 cur_offset = dentry->subdir_offset;
1166         struct dentry *prev_child = NULL;
1167         struct dentry *first_child = NULL;
1168         struct dentry *child;
1169         struct dentry cur_child;
1170         int ret;
1171
1172         /* If @dentry is a regular file, nothing more needs to be done for this
1173          * branch. */
1174         if (cur_offset == 0)
1175                 return 0;
1176
1177         /* Find and read all the children of @dentry. */
1178         while (1) {
1179
1180                 /* Read next child of @dentry into @cur_child. */
1181                 ret = read_dentry(metadata_resource, metadata_resource_len,
1182                                   cur_offset, &cur_child);
1183                 if (ret != 0)
1184                         break;
1185
1186                 /* Check for end of directory. */
1187                 if (cur_child.length == 0) {
1188                         ret = 0;
1189                         break;
1190                 }
1191
1192                 /* Not end of directory.  Allocate this child permanently and
1193                  * link it to the parent and previous child. */
1194                 child = MALLOC(sizeof(struct dentry));
1195                 if (!child) {
1196                         ERROR("Failed to allocate %zu bytes for new dentry",
1197                               sizeof(struct dentry));
1198                         ret = WIMLIB_ERR_NOMEM;
1199                         break;
1200                 }
1201                 memcpy(child, &cur_child, sizeof(struct dentry));
1202
1203                 if (prev_child) {
1204                         prev_child->next = child;
1205                         child->prev = prev_child;
1206                 } else {
1207                         first_child = child;
1208                 }
1209
1210                 child->parent = dentry;
1211                 prev_child = child;
1212
1213                 /* If there are children of this child, call this procedure
1214                  * recursively. */
1215                 if (child->subdir_offset != 0) {
1216                         ret = read_dentry_tree(metadata_resource,
1217                                                metadata_resource_len, child);
1218                         if (ret != 0)
1219                                 break;
1220                 }
1221
1222                 /* Advance to the offset of the next child. */
1223                 cur_offset += dentry_total_length(child);
1224         }
1225
1226         /* Link last child to first one, and set parent's
1227          * children pointer to the first child.  */
1228         if (prev_child) {
1229                 prev_child->next = first_child;
1230                 first_child->prev = prev_child;
1231         }
1232         dentry->children = first_child;
1233         return ret;
1234 }