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   1 /*
   2  * dentry.c
   3  *
   4  * In the WIM file format, the dentries are stored in the "metadata resource"
   5  * section right after the security data.  Each image in the WIM file has its
   6  * own metadata resource with its own security data and dentry tree.  Dentries
   7  * in different images may share file resources by referring to the same lookup
   8  * table entries.
   9  */
  10
  11 /*
  12  * Copyright (C) 2012, 2013 Eric Biggers
  13  *
  14  * This file is part of wimlib, a library for working with WIM files.
  15  *
  16  * wimlib is free software; you can redistribute it and/or modify it under the
  17  * terms of the GNU General Public License as published by the Free Software
  18  * Foundation; either version 3 of the License, or (at your option) any later
  19  * version.
  20  *
  21  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  22  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  23  * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License along with
  26  * wimlib; if not, see http://www.gnu.org/licenses/.
  27  */
  28
  29 #include "buffer_io.h"
  30 #include "dentry.h"
  31 #include "lookup_table.h"
  32 #include "timestamp.h"
  33 #include "wimlib_internal.h"
  34 #include <errno.h>
  35
  36 /* Calculates the unaligned length, in bytes, of an on-disk WIM dentry that has
  37  * a file name and short name that take the specified numbers of bytes.  This
  38  * excludes any alternate data stream entries that may follow the dentry. */
  39 static u64
  40 __dentry_correct_length_unaligned(u16 file_name_nbytes, u16 short_name_nbytes)
  41 {
  42         u64 length = WIM_DENTRY_DISK_SIZE;
  43         if (file_name_nbytes)
  44                 length += file_name_nbytes + 2;
  45         if (short_name_nbytes)
  46                 length += short_name_nbytes + 2;
  47         return length;
  48 }
  49
  50 /* Calculates the unaligned length, in bytes, of an on-disk WIM dentry, based on
  51  * the file name length and short name length.  Note that dentry->length is
  52  * ignored; also, this excludes any alternate data stream entries that may
  53  * follow the dentry. */
  54 static u64
  55 dentry_correct_length_unaligned(const struct wim_dentry *dentry)
  56 {
  57         return __dentry_correct_length_unaligned(dentry->file_name_nbytes,
  58                                                  dentry->short_name_nbytes);
  59 }
  60
  61 /* Return the "correct" value to write in the length field of a WIM dentry,
  62  * based on the file name length and short name length. */
  63 static u64
  64 dentry_correct_length(const struct wim_dentry *dentry)
  65 {
  66         return (dentry_correct_length_unaligned(dentry) + 7) & ~7;
  67 }
  68
  69 /* Return %true iff the alternate data stream entry @entry has the UTF-16LE
  70  * stream name @name that has length @name_nbytes bytes. */
  71 static inline bool
  72 ads_entry_has_name(const struct wim_ads_entry *entry,
  73                    const utf16lechar *name, size_t name_nbytes)
  74 {
  75         return entry->stream_name_nbytes == name_nbytes &&
  76                memcmp(entry->stream_name, name, name_nbytes) == 0;
  77 }
  78
  79 /* Duplicates a string of system-dependent encoding into a UTF-16LE string and
  80  * returns the string and its length, in bytes, in the pointer arguments.  Frees
  81  * any existing string at the return location before overwriting it. */
  82 static int
  83 get_utf16le_name(const tchar *name, utf16lechar **name_utf16le_ret,
  84                  u16 *name_utf16le_nbytes_ret)
  85 {
  86         utf16lechar *name_utf16le;
  87         size_t name_utf16le_nbytes;
  88         int ret;
  89 #if TCHAR_IS_UTF16LE
  90         name_utf16le_nbytes = tstrlen(name) * sizeof(utf16lechar);
  91         name_utf16le = MALLOC(name_utf16le_nbytes + sizeof(utf16lechar));
  92         if (!name_utf16le)
  93                 return WIMLIB_ERR_NOMEM;
  94         memcpy(name_utf16le, name, name_utf16le_nbytes + sizeof(utf16lechar));
  95         ret = 0;
  96 #else
  97
  98         ret = tstr_to_utf16le(name, tstrlen(name), &name_utf16le,
  99                               &name_utf16le_nbytes);
 100         if (ret == 0) {
 101                 if (name_utf16le_nbytes > 0xffff) {
 102                         FREE(name_utf16le);
 103                         ERROR("Multibyte string \"%"TS"\" is too long!", name);
 104                         ret = WIMLIB_ERR_INVALID_UTF8_STRING;
 105                 }
 106         }
 107 #endif
 108         if (ret == 0) {
 109                 FREE(*name_utf16le_ret);
 110                 *name_utf16le_ret = name_utf16le;
 111                 *name_utf16le_nbytes_ret = name_utf16le_nbytes;
 112         }
 113         return ret;
 114 }
 115
 116 /* Sets the name of a WIM dentry from a multibyte string. */
 117 int
 118 set_dentry_name(struct wim_dentry *dentry, const tchar *new_name)
 119 {
 120         int ret;
 121         ret = get_utf16le_name(new_name, &dentry->file_name,
 122                                &dentry->file_name_nbytes);
 123         if (ret == 0) {
 124                 /* Clear the short name and recalculate the dentry length */
 125                 if (dentry_has_short_name(dentry)) {
 126                         FREE(dentry->short_name);
 127                         dentry->short_name = NULL;
 128                         dentry->short_name_nbytes = 0;
 129                 }
 130                 dentry->length = dentry_correct_length(dentry);
 131         }
 132         return ret;
 133 }
 134
 135 /* Returns the total length of a WIM alternate data stream entry on-disk,
 136  * including the stream name, the null terminator, AND the padding after the
 137  * entry to align the next ADS entry or dentry on an 8-byte boundary. */
 138 static u64
 139 ads_entry_total_length(const struct wim_ads_entry *entry)
 140 {
 141         u64 len = WIM_ADS_ENTRY_DISK_SIZE;
 142         if (entry->stream_name_nbytes)
 143                 len += entry->stream_name_nbytes + 2;
 144         return (len + 7) & ~7;
 145 }
 146
 147
 148 static u64
 149 __dentry_total_length(const struct wim_dentry *dentry, u64 length)
 150 {
 151         const struct wim_inode *inode = dentry->d_inode;
 152         for (u16 i = 0; i < inode->i_num_ads; i++)
 153                 length += ads_entry_total_length(&inode->i_ads_entries[i]);
 154         return (length + 7) & ~7;
 155 }
 156
 157 /* Calculate the aligned *total* length of an on-disk WIM dentry.  This includes
 158  * all alternate data streams. */
 159 u64
 160 dentry_correct_total_length(const struct wim_dentry *dentry)
 161 {
 162         return __dentry_total_length(dentry,
 163                                      dentry_correct_length_unaligned(dentry));
 164 }
 165
 166 /* Like dentry_correct_total_length(), but use the existing dentry->length field
 167  * instead of calculating its "correct" value. */
 168 static u64
 169 dentry_total_length(const struct wim_dentry *dentry)
 170 {
 171         return __dentry_total_length(dentry, dentry->length);
 172 }
 173
 174 int
 175 for_dentry_in_rbtree(struct rb_node *root,
 176                      int (*visitor)(struct wim_dentry *, void *),
 177                      void *arg)
 178 {
 179         int ret;
 180         struct rb_node *node = root;
 181         LIST_HEAD(stack);
 182         while (1) {
 183                 if (node) {
 184                         list_add(&rbnode_dentry(node)->tmp_list, &stack);
 185                         node = node->rb_left;
 186                 } else {
 187                         struct list_head *next;
 188                         struct wim_dentry *dentry;
 189
 190                         next = stack.next;
 191                         if (next == &stack)
 192                                 return 0;
 193                         dentry = container_of(next, struct wim_dentry, tmp_list);
 194                         list_del(next);
 195                         ret = visitor(dentry, arg);
 196                         if (ret != 0)
 197                                 return ret;
 198                         node = dentry->rb_node.rb_right;
 199                 }
 200         }
 201 }
 202
 203 static int
 204 for_dentry_tree_in_rbtree_depth(struct rb_node *node,
 205                                 int (*visitor)(struct wim_dentry*, void*),
 206                                 void *arg)
 207 {
 208         int ret;
 209         if (node) {
 210                 ret = for_dentry_tree_in_rbtree_depth(node->rb_left,
 211                                                       visitor, arg);
 212                 if (ret != 0)
 213                         return ret;
 214                 ret = for_dentry_tree_in_rbtree_depth(node->rb_right,
 215                                                       visitor, arg);
 216                 if (ret != 0)
 217                         return ret;
 218                 ret = for_dentry_in_tree_depth(rbnode_dentry(node), visitor, arg);
 219                 if (ret != 0)
 220                         return ret;
 221         }
 222         return 0;
 223 }
 224
 225 static int
 226 for_dentry_tree_in_rbtree(struct rb_node *node,
 227                           int (*visitor)(struct wim_dentry*, void*),
 228                           void *arg)
 229 {
 230         int ret;
 231         if (node) {
 232                 ret = for_dentry_tree_in_rbtree(node->rb_left, visitor, arg);
 233                 if (ret != 0)
 234                         return ret;
 235                 ret = for_dentry_in_tree(rbnode_dentry(node), visitor, arg);
 236                 if (ret != 0)
 237                         return ret;
 238                 ret = for_dentry_tree_in_rbtree(node->rb_right, visitor, arg);
 239                 if (ret != 0)
 240                         return ret;
 241         }
 242         return 0;
 243 }
 244
 245 /* Calls a function on all directory entries in a WIM dentry tree.  Logically,
 246  * this is a pre-order traversal (the function is called on a parent dentry
 247  * before its children), but sibling dentries will be visited in order as well.
 248  * */
 249 int
 250 for_dentry_in_tree(struct wim_dentry *root,
 251                    int (*visitor)(struct wim_dentry*, void*), void *arg)
 252 {
 253         int ret = visitor(root, arg);
 254         if (ret == 0) {
 255                 ret = for_dentry_tree_in_rbtree(root->d_inode->i_children.rb_node,
 256                                                 visitor,
 257                                                 arg);
 258         }
 259         return ret;
 260 }
 261
 262 /* Like for_dentry_in_tree(), but the visitor function is always called on a
 263  * dentry's children before on itself. */
 264 int
 265 for_dentry_in_tree_depth(struct wim_dentry *root,
 266                          int (*visitor)(struct wim_dentry*, void*), void *arg)
 267 {
 268         int ret;
 269         ret = for_dentry_tree_in_rbtree_depth(root->d_inode->i_children.rb_node,
 270                                               visitor, arg);
 271         if (ret == 0)
 272                 ret = visitor(root, arg);
 273         return ret;
 274 }
 275
 276 /* Calculate the full path of @dentry.  The full path of its parent must have
 277  * already been calculated, or it must be the root dentry. */
 278 static int
 279 calculate_dentry_full_path(struct wim_dentry *dentry)
 280 {
 281         tchar *full_path;
 282         u32 full_path_nbytes;
 283         int ret;
 284
 285         if (dentry->_full_path)
 286                 return 0;
 287
 288         if (dentry_is_root(dentry)) {
 289                 full_path = TSTRDUP(T("/"));
 290                 if (!full_path)
 291                         return WIMLIB_ERR_NOMEM;
 292                 full_path_nbytes = 1 * sizeof(tchar);
 293         } else {
 294                 struct wim_dentry *parent;
 295                 tchar *parent_full_path;
 296                 u32 parent_full_path_nbytes;
 297                 size_t filename_nbytes;
 298
 299                 parent = dentry->parent;
 300                 if (dentry_is_root(parent)) {
 301                         parent_full_path = T("");
 302                         parent_full_path_nbytes = 0;
 303                 } else {
 304                         if (!parent->_full_path) {
 305                                 ret = calculate_dentry_full_path(parent);
 306                                 if (ret)
 307                                         return ret;
 308                         }
 309                         parent_full_path = parent->_full_path;
 310                         parent_full_path_nbytes = parent->full_path_nbytes;
 311                 }
 312
 313                 /* Append this dentry's name as a tchar string to the full path
 314                  * of the parent followed by the path separator */
 315         #if TCHAR_IS_UTF16LE
 316                 filename_nbytes = dentry->file_name_nbytes;
 317         #else
 318                 {
 319                         int ret = utf16le_to_tstr_nbytes(dentry->file_name,
 320                                                          dentry->file_name_nbytes,
 321                                                          &filename_nbytes);
 322                         if (ret)
 323                                 return ret;
 324                 }
 325         #endif
 326
 327                 full_path_nbytes = parent_full_path_nbytes + sizeof(tchar) +
 328                                    filename_nbytes;
 329                 full_path = MALLOC(full_path_nbytes + sizeof(tchar));
 330                 if (!full_path)
 331                         return WIMLIB_ERR_NOMEM;
 332                 memcpy(full_path, parent_full_path, parent_full_path_nbytes);
 333                 full_path[parent_full_path_nbytes / sizeof(tchar)] = T('/');
 334         #if TCHAR_IS_UTF16LE
 335                 memcpy(&full_path[parent_full_path_nbytes / sizeof(tchar) + 1],
 336                        dentry->file_name,
 337                        filename_nbytes + sizeof(tchar));
 338         #else
 339                 utf16le_to_tstr_buf(dentry->file_name,
 340                                     dentry->file_name_nbytes,
 341                                     &full_path[parent_full_path_nbytes /
 342                                                sizeof(tchar) + 1]);
 343         #endif
 344         }
 345         dentry->_full_path = full_path;
 346         dentry->full_path_nbytes= full_path_nbytes;
 347         return 0;
 348 }
 349
 350 static int
 351 do_calculate_dentry_full_path(struct wim_dentry *dentry, void *_ignore)
 352 {
 353         return calculate_dentry_full_path(dentry);
 354 }
 355
 356 int
 357 calculate_dentry_tree_full_paths(struct wim_dentry *root)
 358 {
 359         return for_dentry_in_tree(root, do_calculate_dentry_full_path, NULL);
 360 }
 361
 362 tchar *
 363 dentry_full_path(struct wim_dentry *dentry)
 364 {
 365         calculate_dentry_full_path(dentry);
 366         return dentry->_full_path;
 367 }
 368
 369 static int
 370 increment_subdir_offset(struct wim_dentry *dentry, void *subdir_offset_p)
 371 {
 372         *(u64*)subdir_offset_p += dentry_correct_total_length(dentry);
 373         return 0;
 374 }
 375
 376 static int
 377 call_calculate_subdir_offsets(struct wim_dentry *dentry, void *subdir_offset_p)
 378 {
 379         calculate_subdir_offsets(dentry, subdir_offset_p);
 380         return 0;
 381 }
 382
 383 /*
 384  * Recursively calculates the subdir offsets for a directory tree.
 385  *
 386  * @dentry:  The root of the directory tree.
 387  * @subdir_offset_p:  The current subdirectory offset; i.e., the subdirectory
 388  *                    offset for @dentry.
 389  */
 390 void
 391 calculate_subdir_offsets(struct wim_dentry *dentry, u64 *subdir_offset_p)
 392 {
 393         struct rb_node *node;
 394
 395         dentry->subdir_offset = *subdir_offset_p;
 396         node = dentry->d_inode->i_children.rb_node;
 397         if (node) {
 398                 /* Advance the subdir offset by the amount of space the children
 399                  * of this dentry take up. */
 400                 for_dentry_in_rbtree(node, increment_subdir_offset, subdir_offset_p);
 401
 402                 /* End-of-directory dentry on disk. */
 403                 *subdir_offset_p += 8;
 404
 405                 /* Recursively call calculate_subdir_offsets() on all the
 406                  * children. */
 407                 for_dentry_in_rbtree(node, call_calculate_subdir_offsets, subdir_offset_p);
 408         } else {
 409                 /* On disk, childless directories have a valid subdir_offset
 410                  * that points to an 8-byte end-of-directory dentry.  Regular
 411                  * files or reparse points have a subdir_offset of 0. */
 412                 if (dentry_is_directory(dentry))
 413                         *subdir_offset_p += 8;
 414                 else
 415                         dentry->subdir_offset = 0;
 416         }
 417 }
 418
 419 static int
 420 compare_utf16le_names(const utf16lechar *name1, size_t nbytes1,
 421                       const utf16lechar *name2, size_t nbytes2)
 422 {
 423         int result = memcmp(name1, name2, min(nbytes1, nbytes2));
 424         if (result)
 425                 return result;
 426         else
 427                 return (int)nbytes1 - (int)nbytes2;
 428 }
 429
 430 static int
 431 dentry_compare_names(const struct wim_dentry *d1, const struct wim_dentry *d2)
 432 {
 433         return compare_utf16le_names(d1->file_name, d1->file_name_nbytes,
 434                                      d2->file_name, d2->file_name_nbytes);
 435 }
 436
 437
 438 struct wim_dentry *
 439 get_dentry_child_with_utf16le_name(const struct wim_dentry *dentry,
 440                                    const utf16lechar *name,
 441                                    size_t name_nbytes)
 442 {
 443         struct rb_node *node = dentry->d_inode->i_children.rb_node;
 444         struct wim_dentry *child;
 445         while (node) {
 446                 child = rbnode_dentry(node);
 447                 int result = compare_utf16le_names(name, name_nbytes,
 448                                                    child->file_name,
 449                                                    child->file_name_nbytes);
 450                 if (result < 0)
 451                         node = node->rb_left;
 452                 else if (result > 0)
 453                         node = node->rb_right;
 454                 else
 455                         return child;
 456         }
 457         return NULL;
 458 }
 459
 460 /* Returns the child of @dentry that has the file name @name.  Returns NULL if
 461  * no child has the name. */
 462 struct wim_dentry *
 463 get_dentry_child_with_name(const struct wim_dentry *dentry, const tchar *name)
 464 {
 465 #if TCHAR_IS_UTF16LE
 466         return get_dentry_child_with_utf16le_name(dentry, name,
 467                                                   tstrlen(name) * sizeof(tchar));
 468 #else
 469         utf16lechar *utf16le_name;
 470         size_t utf16le_name_nbytes;
 471         int ret;
 472         struct wim_dentry *child;
 473
 474         ret = tstr_to_utf16le(name, tstrlen(name) * sizeof(tchar),
 475                               &utf16le_name, &utf16le_name_nbytes);
 476         if (ret) {
 477                 child = NULL;
 478         } else {
 479                 child = get_dentry_child_with_utf16le_name(dentry,
 480                                                            utf16le_name,
 481                                                            utf16le_name_nbytes);
 482                 FREE(utf16le_name);
 483         }
 484         return child;
 485 #endif
 486 }
 487
 488 static struct wim_dentry *
 489 get_dentry_utf16le(WIMStruct *w, const utf16lechar *path,
 490                    size_t path_nbytes)
 491 {
 492         struct wim_dentry *cur_dentry, *parent_dentry;
 493         const utf16lechar *p, *pp;
 494
 495         cur_dentry = parent_dentry = wim_root_dentry(w);
 496         p = path;
 497         while (1) {
 498                 while (*p == cpu_to_le16('/'))
 499                         p++;
 500                 if (*p == '\0')
 501                         break;
 502                 pp = p;
 503                 while (*pp != cpu_to_le16('/') && *pp != cpu_to_le16('\0'))
 504                         pp++;
 505
 506                 cur_dentry = get_dentry_child_with_utf16le_name(parent_dentry, p,
 507                                                                 (void*)pp - (void*)p);
 508                 if (cur_dentry == NULL)
 509                         break;
 510                 p = pp;
 511                 parent_dentry = cur_dentry;
 512         }
 513         if (cur_dentry == NULL) {
 514                 if (dentry_is_directory(parent_dentry))
 515                         errno = ENOENT;
 516                 else
 517                         errno = ENOTDIR;
 518         }
 519         return cur_dentry;
 520 }
 521
 522 /* Returns the dentry corresponding to the @path, or NULL if there is no such
 523  * dentry. */
 524 struct wim_dentry *
 525 get_dentry(WIMStruct *w, const tchar *path)
 526 {
 527 #if TCHAR_IS_UTF16LE
 528         return get_dentry_utf16le(w, path, tstrlen(path) * sizeof(tchar));
 529 #else
 530         utf16lechar *path_utf16le;
 531         size_t path_utf16le_nbytes;
 532         int ret;
 533         struct wim_dentry *dentry;
 534
 535         ret = tstr_to_utf16le(path, tstrlen(path) * sizeof(tchar),
 536                               &path_utf16le, &path_utf16le_nbytes);
 537         if (ret)
 538                 return NULL;
 539         dentry = get_dentry_utf16le(w, path_utf16le, path_utf16le_nbytes);
 540         FREE(path_utf16le);
 541         return dentry;
 542 #endif
 543 }
 544
 545 struct wim_inode *
 546 wim_pathname_to_inode(WIMStruct *w, const tchar *path)
 547 {
 548         struct wim_dentry *dentry;
 549         dentry = get_dentry(w, path);
 550         if (dentry)
 551                 return dentry->d_inode;
 552         else
 553                 return NULL;
 554 }
 555
 556 /* Takes in a path of length @len in @buf, and transforms it into a string for
 557  * the path of its parent directory. */
 558 static void
 559 to_parent_name(tchar *buf, size_t len)
 560 {
 561         ssize_t i = (ssize_t)len - 1;
 562         while (i >= 0 && buf[i] == T('/'))
 563                 i--;
 564         while (i >= 0 && buf[i] != T('/'))
 565                 i--;
 566         while (i >= 0 && buf[i] == T('/'))
 567                 i--;
 568         buf[i + 1] = T('\0');
 569 }
 570
 571 /* Returns the dentry that corresponds to the parent directory of @path, or NULL
 572  * if the dentry is not found. */
 573 struct wim_dentry *
 574 get_parent_dentry(WIMStruct *w, const tchar *path)
 575 {
 576         size_t path_len = tstrlen(path);
 577         tchar buf[path_len + 1];
 578
 579         tmemcpy(buf, path, path_len + 1);
 580         to_parent_name(buf, path_len);
 581         return get_dentry(w, buf);
 582 }
 583
 584 /* Prints the full path of a dentry. */
 585 int
 586 print_dentry_full_path(struct wim_dentry *dentry, void *_ignore)
 587 {
 588         int ret = calculate_dentry_full_path(dentry);
 589         if (ret)
 590                 return ret;
 591         tprintf(T("%"TS"\n"), dentry->_full_path);
 592         return 0;
 593 }
 594
 595 /* We want to be able to show the names of the file attribute flags that are
 596  * set. */
 597 struct file_attr_flag {
 598         u32 flag;
 599         const tchar *name;
 600 };
 601 struct file_attr_flag file_attr_flags[] = {
 602         {FILE_ATTRIBUTE_READONLY,           T("READONLY")},
 603         {FILE_ATTRIBUTE_HIDDEN,             T("HIDDEN")},
 604         {FILE_ATTRIBUTE_SYSTEM,             T("SYSTEM")},
 605         {FILE_ATTRIBUTE_DIRECTORY,          T("DIRECTORY")},
 606         {FILE_ATTRIBUTE_ARCHIVE,            T("ARCHIVE")},
 607         {FILE_ATTRIBUTE_DEVICE,             T("DEVICE")},
 608         {FILE_ATTRIBUTE_NORMAL,             T("NORMAL")},
 609         {FILE_ATTRIBUTE_TEMPORARY,          T("TEMPORARY")},
 610         {FILE_ATTRIBUTE_SPARSE_FILE,        T("SPARSE_FILE")},
 611         {FILE_ATTRIBUTE_REPARSE_POINT,      T("REPARSE_POINT")},
 612         {FILE_ATTRIBUTE_COMPRESSED,         T("COMPRESSED")},
 613         {FILE_ATTRIBUTE_OFFLINE,            T("OFFLINE")},
 614         {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,T("NOT_CONTENT_INDEXED")},
 615         {FILE_ATTRIBUTE_ENCRYPTED,          T("ENCRYPTED")},
 616         {FILE_ATTRIBUTE_VIRTUAL,            T("VIRTUAL")},
 617 };
 618
 619 /* Prints a directory entry.  @lookup_table is a pointer to the lookup table, if
 620  * available.  If the dentry is unresolved and the lookup table is NULL, the
 621  * lookup table entries will not be printed.  Otherwise, they will be. */
 622 int
 623 print_dentry(struct wim_dentry *dentry, void *lookup_table)
 624 {
 625         const u8 *hash;
 626         struct wim_lookup_table_entry *lte;
 627         const struct wim_inode *inode = dentry->d_inode;
 628         tchar buf[50];
 629
 630         tprintf(T("[DENTRY]\n"));
 631         tprintf(T("Length            = %"PRIu64"\n"), dentry->length);
 632         tprintf(T("Attributes        = 0x%x\n"), inode->i_attributes);
 633         for (size_t i = 0; i < ARRAY_LEN(file_attr_flags); i++)
 634                 if (file_attr_flags[i].flag & inode->i_attributes)
 635                         tprintf(T("    FILE_ATTRIBUTE_%"TS" is set\n"),
 636                                 file_attr_flags[i].name);
 637         tprintf(T("Security ID       = %d\n"), inode->i_security_id);
 638         tprintf(T("Subdir offset     = %"PRIu64"\n"), dentry->subdir_offset);
 639
 640         wim_timestamp_to_str(inode->i_creation_time, buf, sizeof(buf));
 641         tprintf(T("Creation Time     = %"TS"\n"), buf);
 642
 643         wim_timestamp_to_str(inode->i_last_access_time, buf, sizeof(buf));
 644         tprintf(T("Last Access Time  = %"TS"\n"), buf);
 645
 646         wim_timestamp_to_str(inode->i_last_write_time, buf, sizeof(buf));
 647         tprintf(T("Last Write Time   = %"TS"\n"), buf);
 648
 649         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 650                 tprintf(T("Reparse Tag       = 0x%"PRIx32"\n"), inode->i_reparse_tag);
 651                 tprintf(T("Reparse Point Flags = 0x%"PRIx16"\n"),
 652                         inode->i_not_rpfixed);
 653                 tprintf(T("Reparse Point Unknown 2 = 0x%"PRIx32"\n"),
 654                         inode->i_rp_unknown_2);
 655         }
 656         tprintf(T("Reparse Point Unknown 1 = 0x%"PRIx32"\n"),
 657                 inode->i_rp_unknown_1);
 658         tprintf(T("Hard Link Group   = 0x%"PRIx64"\n"), inode->i_ino);
 659         tprintf(T("Hard Link Group Size = %"PRIu32"\n"), inode->i_nlink);
 660         tprintf(T("Number of Alternate Data Streams = %hu\n"), inode->i_num_ads);
 661         if (dentry_has_long_name(dentry))
 662                 wimlib_printf(T("Filename = \"%"WS"\"\n"), dentry->file_name);
 663         if (dentry_has_short_name(dentry))
 664                 wimlib_printf(T("Short Name \"%"WS"\"\n"), dentry->short_name);
 665         if (dentry->_full_path)
 666                 tprintf(T("Full Path = \"%"TS"\"\n"), dentry->_full_path);
 667
 668         lte = inode_stream_lte(dentry->d_inode, 0, lookup_table);
 669         if (lte) {
 670                 print_lookup_table_entry(lte, stdout);
 671         } else {
 672                 hash = inode_stream_hash(inode, 0);
 673                 if (hash) {
 674                         tprintf(T("Hash              = 0x"));
 675                         print_hash(hash, stdout);
 676                         tputchar(T('\n'));
 677                         tputchar(T('\n'));
 678                 }
 679         }
 680         for (u16 i = 0; i < inode->i_num_ads; i++) {
 681                 tprintf(T("[Alternate Stream Entry %u]\n"), i);
 682                 wimlib_printf(T("Name = \"%"WS"\"\n"),
 683                               inode->i_ads_entries[i].stream_name);
 684                 tprintf(T("Name Length (UTF16 bytes) = %hu\n"),
 685                        inode->i_ads_entries[i].stream_name_nbytes);
 686                 hash = inode_stream_hash(inode, i + 1);
 687                 if (hash) {
 688                         tprintf(T("Hash              = 0x"));
 689                         print_hash(hash, stdout);
 690                         tputchar(T('\n'));
 691                 }
 692                 print_lookup_table_entry(inode_stream_lte(inode, i + 1, lookup_table),
 693                                          stdout);
 694         }
 695         return 0;
 696 }
 697
 698 /* Initializations done on every `struct wim_dentry'. */
 699 static void
 700 dentry_common_init(struct wim_dentry *dentry)
 701 {
 702         memset(dentry, 0, sizeof(struct wim_dentry));
 703 }
 704
 705 struct wim_inode *
 706 new_timeless_inode()
 707 {
 708         struct wim_inode *inode = CALLOC(1, sizeof(struct wim_inode));
 709         if (inode) {
 710                 inode->i_security_id = -1;
 711                 inode->i_nlink = 1;
 712                 inode->i_next_stream_id = 1;
 713                 inode->i_not_rpfixed = 1;
 714         #ifdef WITH_FUSE
 715                 if (pthread_mutex_init(&inode->i_mutex, NULL) != 0) {
 716                         ERROR_WITH_ERRNO("Error initializing mutex");
 717                         FREE(inode);
 718                         return NULL;
 719                 }
 720         #endif
 721                 INIT_LIST_HEAD(&inode->i_dentry);
 722         }
 723         return inode;
 724 }
 725
 726 static struct wim_inode *
 727 new_inode()
 728 {
 729         struct wim_inode *inode = new_timeless_inode();
 730         if (inode) {
 731                 u64 now = get_wim_timestamp();
 732                 inode->i_creation_time = now;
 733                 inode->i_last_access_time = now;
 734                 inode->i_last_write_time = now;
 735         }
 736         return inode;
 737 }
 738
 739 /* Creates an unlinked directory entry. */
 740 int
 741 new_dentry(const tchar *name, struct wim_dentry **dentry_ret)
 742 {
 743         struct wim_dentry *dentry;
 744         int ret;
 745
 746         dentry = MALLOC(sizeof(struct wim_dentry));
 747         if (!dentry)
 748                 return WIMLIB_ERR_NOMEM;
 749
 750         dentry_common_init(dentry);
 751         ret = set_dentry_name(dentry, name);
 752         if (ret == 0) {
 753                 dentry->parent = dentry;
 754                 *dentry_ret = dentry;
 755         } else {
 756                 FREE(dentry);
 757                 ERROR("Failed to set name on new dentry with name \"%"TS"\"",
 758                       name);
 759         }
 760         return ret;
 761 }
 762
 763
 764 static int
 765 __new_dentry_with_inode(const tchar *name, struct wim_dentry **dentry_ret,
 766                         bool timeless)
 767 {
 768         struct wim_dentry *dentry;
 769         int ret;
 770
 771         ret = new_dentry(name, &dentry);
 772         if (ret)
 773                 return ret;
 774
 775         if (timeless)
 776                 dentry->d_inode = new_timeless_inode();
 777         else
 778                 dentry->d_inode = new_inode();
 779         if (!dentry->d_inode) {
 780                 free_dentry(dentry);
 781                 return WIMLIB_ERR_NOMEM;
 782         }
 783
 784         inode_add_dentry(dentry, dentry->d_inode);
 785         *dentry_ret = dentry;
 786         return 0;
 787 }
 788
 789 int
 790 new_dentry_with_timeless_inode(const tchar *name, struct wim_dentry **dentry_ret)
 791 {
 792         return __new_dentry_with_inode(name, dentry_ret, true);
 793 }
 794
 795 int
 796 new_dentry_with_inode(const tchar *name, struct wim_dentry **dentry_ret)
 797 {
 798         return __new_dentry_with_inode(name, dentry_ret, false);
 799 }
 800
 801
 802 static int
 803 init_ads_entry(struct wim_ads_entry *ads_entry, const void *name,
 804                size_t name_nbytes, bool is_utf16le)
 805 {
 806         int ret = 0;
 807         memset(ads_entry, 0, sizeof(*ads_entry));
 808
 809         if (is_utf16le) {
 810                 utf16lechar *p = MALLOC(name_nbytes + sizeof(utf16lechar));
 811                 if (!p)
 812                         return WIMLIB_ERR_NOMEM;
 813                 memcpy(p, name, name_nbytes);
 814                 p[name_nbytes / 2] = 0;
 815                 ads_entry->stream_name = p;
 816                 ads_entry->stream_name_nbytes = name_nbytes;
 817         } else {
 818                 if (name && *(const tchar*)name != T('\0')) {
 819                         ret = get_utf16le_name(name, &ads_entry->stream_name,
 820                                                &ads_entry->stream_name_nbytes);
 821                 }
 822         }
 823         return ret;
 824 }
 825
 826 static void
 827 destroy_ads_entry(struct wim_ads_entry *ads_entry)
 828 {
 829         FREE(ads_entry->stream_name);
 830 }
 831
 832 /* Frees an inode. */
 833 void
 834 free_inode(struct wim_inode *inode)
 835 {
 836         if (inode) {
 837                 if (inode->i_ads_entries) {
 838                         for (u16 i = 0; i < inode->i_num_ads; i++)
 839                                 destroy_ads_entry(&inode->i_ads_entries[i]);
 840                         FREE(inode->i_ads_entries);
 841                 }
 842         #ifdef WITH_FUSE
 843                 wimlib_assert(inode->i_num_opened_fds == 0);
 844                 FREE(inode->i_fds);
 845                 pthread_mutex_destroy(&inode->i_mutex);
 846                 if (inode->i_hlist.pprev)
 847                         hlist_del(&inode->i_hlist);
 848         #endif
 849                 FREE(inode->i_extracted_file);
 850                 FREE(inode);
 851         }
 852 }
 853
 854 /* Decrements link count on an inode and frees it if the link count reaches 0.
 855  * */
 856 static void
 857 put_inode(struct wim_inode *inode)
 858 {
 859         wimlib_assert(inode->i_nlink != 0);
 860         if (--inode->i_nlink == 0) {
 861         #ifdef WITH_FUSE
 862                 if (inode->i_num_opened_fds == 0)
 863         #endif
 864                 {
 865                         free_inode(inode);
 866                 }
 867         }
 868 }
 869
 870 /* Frees a WIM dentry.
 871  *
 872  * The corresponding inode (if any) is freed only if its link count is
 873  * decremented to 0.
 874  */
 875 void
 876 free_dentry(struct wim_dentry *dentry)
 877 {
 878         FREE(dentry->file_name);
 879         FREE(dentry->short_name);
 880         FREE(dentry->_full_path);
 881         if (dentry->d_inode)
 882                 put_inode(dentry->d_inode);
 883         FREE(dentry);
 884 }
 885
 886 /* This function is passed as an argument to for_dentry_in_tree_depth() in order
 887  * to free a directory tree. */
 888 static int
 889 do_free_dentry(struct wim_dentry *dentry, void *__lookup_table)
 890 {
 891         struct wim_lookup_table *lookup_table = __lookup_table;
 892         unsigned i;
 893
 894         if (lookup_table) {
 895                 struct wim_lookup_table_entry *lte;
 896                 struct wim_inode *inode = dentry->d_inode;
 897                 wimlib_assert(inode->i_nlink != 0);
 898                 for (i = 0; i <= inode->i_num_ads; i++) {
 899                         lte = inode_stream_lte(inode, i, lookup_table);
 900                         if (lte)
 901                                 lte_decrement_refcnt(lte, lookup_table);
 902                 }
 903         }
 904         free_dentry(dentry);
 905         return 0;
 906 }
 907
 908 /*
 909  * Unlinks and frees a dentry tree.
 910  *
 911  * @root:               The root of the tree.
 912  * @lookup_table:       The lookup table for dentries.  If non-NULL, the
 913  *                      reference counts in the lookup table for the lookup
 914  *                      table entries corresponding to the dentries will be
 915  *                      decremented.
 916  */
 917 void
 918 free_dentry_tree(struct wim_dentry *root, struct wim_lookup_table *lookup_table)
 919 {
 920         if (root)
 921                 for_dentry_in_tree_depth(root, do_free_dentry, lookup_table);
 922 }
 923
 924 /*
 925  * Links a dentry into the directory tree.
 926  *
 927  * @parent: The dentry that will be the parent of @dentry.
 928  * @dentry: The dentry to link.
 929  */
 930 struct wim_dentry *
 931 dentry_add_child(struct wim_dentry * restrict parent,
 932                  struct wim_dentry * restrict child)
 933 {
 934         wimlib_assert(dentry_is_directory(parent));
 935
 936         struct rb_root *root = &parent->d_inode->i_children;
 937         struct rb_node **new = &(root->rb_node);
 938         struct rb_node *rb_parent = NULL;
 939
 940         while (*new) {
 941                 struct wim_dentry *this = rbnode_dentry(*new);
 942                 int result = dentry_compare_names(child, this);
 943
 944                 rb_parent = *new;
 945
 946                 if (result < 0)
 947                         new = &((*new)->rb_left);
 948                 else if (result > 0)
 949                         new = &((*new)->rb_right);
 950                 else
 951                         return this;
 952         }
 953         child->parent = parent;
 954         rb_link_node(&child->rb_node, rb_parent, new);
 955         rb_insert_color(&child->rb_node, root);
 956         return NULL;
 957 }
 958
 959 /* Unlink a WIM dentry from the directory entry tree. */
 960 void
 961 unlink_dentry(struct wim_dentry *dentry)
 962 {
 963         struct wim_dentry *parent = dentry->parent;
 964         if (parent == dentry)
 965                 return;
 966         rb_erase(&dentry->rb_node, &parent->d_inode->i_children);
 967 }
 968
 969 /*
 970  * Returns the alternate data stream entry belonging to @inode that has the
 971  * stream name @stream_name.
 972  */
 973 struct wim_ads_entry *
 974 inode_get_ads_entry(struct wim_inode *inode, const tchar *stream_name,
 975                     u16 *idx_ret)
 976 {
 977         if (inode->i_num_ads == 0) {
 978                 return NULL;
 979         } else {
 980                 size_t stream_name_utf16le_nbytes;
 981                 u16 i;
 982                 struct wim_ads_entry *result;
 983
 984         #if TCHAR_IS_UTF16LE
 985                 const utf16lechar *stream_name_utf16le;
 986
 987                 stream_name_utf16le = stream_name;
 988                 stream_name_utf16le_nbytes = tstrlen(stream_name) * sizeof(tchar);
 989         #else
 990                 utf16lechar *stream_name_utf16le;
 991
 992                 {
 993                         int ret = tstr_to_utf16le(stream_name,
 994                                                   tstrlen(stream_name) *
 995                                                       sizeof(tchar),
 996                                                   &stream_name_utf16le,
 997                                                   &stream_name_utf16le_nbytes);
 998                         if (ret)
 999                                 return NULL;
1000                 }
1001         #endif
1002                 i = 0;
1003                 result = NULL;
1004                 do {
1005                         if (ads_entry_has_name(&inode->i_ads_entries[i],
1006                                                stream_name_utf16le,
1007                                                stream_name_utf16le_nbytes))
1008                         {
1009                                 if (idx_ret)
1010                                         *idx_ret = i;
1011                                 result = &inode->i_ads_entries[i];
1012                                 break;
1013                         }
1014                 } while (++i != inode->i_num_ads);
1015         #if !TCHAR_IS_UTF16LE
1016                 FREE(stream_name_utf16le);
1017         #endif
1018                 return result;
1019         }
1020 }
1021
1022 static struct wim_ads_entry *
1023 do_inode_add_ads(struct wim_inode *inode, const void *stream_name,
1024                  size_t stream_name_nbytes, bool is_utf16le)
1025 {
1026         u16 num_ads;
1027         struct wim_ads_entry *ads_entries;
1028         struct wim_ads_entry *new_entry;
1029
1030         if (inode->i_num_ads >= 0xfffe) {
1031                 ERROR("Too many alternate data streams in one inode!");
1032                 return NULL;
1033         }
1034         num_ads = inode->i_num_ads + 1;
1035         ads_entries = REALLOC(inode->i_ads_entries,
1036                               num_ads * sizeof(inode->i_ads_entries[0]));
1037         if (!ads_entries) {
1038                 ERROR("Failed to allocate memory for new alternate data stream");
1039                 return NULL;
1040         }
1041         inode->i_ads_entries = ads_entries;
1042
1043         new_entry = &inode->i_ads_entries[num_ads - 1];
1044         if (init_ads_entry(new_entry, stream_name, stream_name_nbytes, is_utf16le))
1045                 return NULL;
1046         new_entry->stream_id = inode->i_next_stream_id++;
1047         inode->i_num_ads = num_ads;
1048         return new_entry;
1049 }
1050
1051 struct wim_ads_entry *
1052 inode_add_ads_utf16le(struct wim_inode *inode,
1053                       const utf16lechar *stream_name,
1054                       size_t stream_name_nbytes)
1055 {
1056         DEBUG("Add alternate data stream \"%"WS"\"", stream_name);
1057         return do_inode_add_ads(inode, stream_name, stream_name_nbytes, true);
1058 }
1059
1060 /*
1061  * Add an alternate stream entry to a WIM inode and return a pointer to it, or
1062  * NULL if memory could not be allocated.
1063  */
1064 struct wim_ads_entry *
1065 inode_add_ads(struct wim_inode *inode, const tchar *stream_name)
1066 {
1067         DEBUG("Add alternate data stream \"%"TS"\"", stream_name);
1068         return do_inode_add_ads(inode, stream_name,
1069                                 tstrlen(stream_name) * sizeof(tchar),
1070                                 TCHAR_IS_UTF16LE);
1071 }
1072
1073 int
1074 inode_add_ads_with_data(struct wim_inode *inode, const tchar *name,
1075                         const void *value, size_t size,
1076                         struct wim_lookup_table *lookup_table)
1077 {
1078         int ret = WIMLIB_ERR_NOMEM;
1079         struct wim_ads_entry *new_ads_entry;
1080         struct wim_lookup_table_entry *existing_lte;
1081         struct wim_lookup_table_entry *lte;
1082         u8 value_hash[SHA1_HASH_SIZE];
1083
1084         wimlib_assert(inode->i_resolved);
1085         new_ads_entry = inode_add_ads(inode, name);
1086         if (!new_ads_entry)
1087                 goto out;
1088         sha1_buffer((const u8*)value, size, value_hash);
1089         existing_lte = __lookup_resource(lookup_table, value_hash);
1090         if (existing_lte) {
1091                 lte = existing_lte;
1092                 lte->refcnt++;
1093         } else {
1094                 u8 *value_copy;
1095                 lte = new_lookup_table_entry();
1096                 if (!lte)
1097                         goto out_remove_ads_entry;
1098                 value_copy = MALLOC(size);
1099                 if (!value_copy) {
1100                         FREE(lte);
1101                         goto out_remove_ads_entry;
1102                 }
1103                 memcpy(value_copy, value, size);
1104                 lte->resource_location            = RESOURCE_IN_ATTACHED_BUFFER;
1105                 lte->attached_buffer              = value_copy;
1106                 lte->resource_entry.original_size = size;
1107                 lte->resource_entry.size          = size;
1108                 copy_hash(lte->hash, value_hash);
1109                 lookup_table_insert(lookup_table, lte);
1110         }
1111         new_ads_entry->lte = lte;
1112         ret = 0;
1113         goto out;
1114 out_remove_ads_entry:
1115         inode_remove_ads(inode, new_ads_entry - inode->i_ads_entries,
1116                          lookup_table);
1117 out:
1118         return ret;
1119 }
1120
1121 /* Remove an alternate data stream from a WIM inode  */
1122 void
1123 inode_remove_ads(struct wim_inode *inode, u16 idx,
1124                  struct wim_lookup_table *lookup_table)
1125 {
1126         struct wim_ads_entry *ads_entry;
1127         struct wim_lookup_table_entry *lte;
1128
1129         wimlib_assert(idx < inode->i_num_ads);
1130         wimlib_assert(inode->i_resolved);
1131
1132         ads_entry = &inode->i_ads_entries[idx];
1133
1134         DEBUG("Remove alternate data stream \"%"WS"\"", ads_entry->stream_name);
1135
1136         lte = ads_entry->lte;
1137         if (lte)
1138                 lte_decrement_refcnt(lte, lookup_table);
1139
1140         destroy_ads_entry(ads_entry);
1141
1142         memmove(&inode->i_ads_entries[idx],
1143                 &inode->i_ads_entries[idx + 1],
1144                 (inode->i_num_ads - idx - 1) * sizeof(inode->i_ads_entries[0]));
1145         inode->i_num_ads--;
1146 }
1147
1148 #ifndef __WIN32__
1149 int
1150 inode_get_unix_data(const struct wim_inode *inode,
1151                     struct wimlib_unix_data *unix_data,
1152                     u16 *stream_idx_ret)
1153 {
1154         const struct wim_ads_entry *ads_entry;
1155         const struct wim_lookup_table_entry *lte;
1156         size_t size;
1157         int ret;
1158
1159         wimlib_assert(inode->i_resolved);
1160
1161         ads_entry = inode_get_ads_entry((struct wim_inode*)inode,
1162                                         WIMLIB_UNIX_DATA_TAG, NULL);
1163         if (!ads_entry)
1164                 return NO_UNIX_DATA;
1165
1166         if (stream_idx_ret)
1167                 *stream_idx_ret = ads_entry - inode->i_ads_entries;
1168
1169         lte = ads_entry->lte;
1170         if (!lte)
1171                 return NO_UNIX_DATA;
1172
1173         size = wim_resource_size(lte);
1174         if (size != sizeof(struct wimlib_unix_data))
1175                 return BAD_UNIX_DATA;
1176
1177         ret = read_full_resource_into_buf(lte, unix_data, true);
1178         if (ret)
1179                 return ret;
1180
1181         if (unix_data->version != 0)
1182                 return BAD_UNIX_DATA;
1183         return 0;
1184 }
1185
1186 int
1187 inode_set_unix_data(struct wim_inode *inode, uid_t uid, gid_t gid, mode_t mode,
1188                     struct wim_lookup_table *lookup_table, int which)
1189 {
1190         struct wimlib_unix_data unix_data;
1191         int ret;
1192         bool have_good_unix_data = false;
1193         bool have_unix_data = false;
1194         u16 stream_idx;
1195
1196         if (!(which & UNIX_DATA_CREATE)) {
1197                 ret = inode_get_unix_data(inode, &unix_data, &stream_idx);
1198                 if (ret == 0 || ret == BAD_UNIX_DATA || ret > 0)
1199                         have_unix_data = true;
1200                 if (ret == 0)
1201                         have_good_unix_data = true;
1202         }
1203         unix_data.version = 0;
1204         if (which & UNIX_DATA_UID || !have_good_unix_data)
1205                 unix_data.uid = uid;
1206         if (which & UNIX_DATA_GID || !have_good_unix_data)
1207                 unix_data.gid = gid;
1208         if (which & UNIX_DATA_MODE || !have_good_unix_data)
1209                 unix_data.mode = mode;
1210         ret = inode_add_ads_with_data(inode, WIMLIB_UNIX_DATA_TAG,
1211                                       &unix_data,
1212                                       sizeof(struct wimlib_unix_data),
1213                                       lookup_table);
1214         if (ret == 0 && have_unix_data)
1215                 inode_remove_ads(inode, stream_idx, lookup_table);
1216         return ret;
1217 }
1218 #endif /* !__WIN32__ */
1219
1220 static void
1221 replace_forbidden_characters(utf16lechar *name)
1222 {
1223         utf16lechar *p;
1224
1225         for (p = name; *p; p++) {
1226         #ifdef __WIN32__
1227                 if (wcschr(L"<>:\"/\\|?*", (wchar_t)*p))
1228         #else
1229                 if (*p == '/')
1230         #endif
1231                 {
1232                         if (name) {
1233                                 WARNING("File, directory, or stream name \"%"WS"\"\n"
1234                                         "          contains forbidden characters; "
1235                                         "replacing them with Unicode codepoint U+001A",
1236                                         name);
1237                                 name = NULL;
1238                         }
1239                         *p = 0x1a;
1240                 }
1241         }
1242 }
1243
1244 /*
1245  * Reads the alternate data stream entries of a WIM dentry.
1246  *
1247  * @p:  Pointer to buffer that starts with the first alternate stream entry.
1248  *
1249  * @inode:      Inode to load the alternate data streams into.
1250  *                      @inode->i_num_ads must have been set to the number of
1251  *                      alternate data streams that are expected.
1252  *
1253  * @remaining_size:     Number of bytes of data remaining in the buffer pointed
1254  *                              to by @p.
1255  *
1256  * The format of the on-disk alternate stream entries is as follows:
1257  *
1258  * struct wim_ads_entry_on_disk {
1259  *      u64  length;          // Length of the entry, in bytes.  This includes
1260  *                                  all fields (including the stream name and
1261  *                                  null terminator if present, AND the padding!).
1262  *      u64  reserved;        // Seems to be unused
1263  *      u8   hash[20];        // SHA1 message digest of the uncompressed stream
1264  *      u16  stream_name_len; // Length of the stream name, in bytes
1265  *      char stream_name[];   // Stream name in UTF-16LE, @stream_name_len bytes long,
1266  *                                  not including null terminator
1267  *      u16  zero;            // UTF-16 null terminator for the stream name, NOT
1268  *                                  included in @stream_name_len.  Based on what
1269  *                                  I've observed from filenames in dentries,
1270  *                                  this field should not exist when
1271  *                                  (@stream_name_len == 0), but you can't
1272  *                                  actually tell because of the padding anyway
1273  *                                  (provided that the padding is zeroed, which
1274  *                                  it always seems to be).
1275  *      char padding[];       // Padding to make the size a multiple of 8 bytes.
1276  * };
1277  *
1278  * In addition, the entries are 8-byte aligned.
1279  *
1280  * Return 0 on success or nonzero on failure.  On success, inode->i_ads_entries
1281  * is set to an array of `struct wim_ads_entry's of length inode->i_num_ads.  On
1282  * failure, @inode is not modified.
1283  */
1284 static int
1285 read_ads_entries(const u8 *p, struct wim_inode *inode, u64 remaining_size)
1286 {
1287         u16 num_ads;
1288         struct wim_ads_entry *ads_entries;
1289         int ret;
1290
1291         num_ads = inode->i_num_ads;
1292         ads_entries = CALLOC(num_ads, sizeof(inode->i_ads_entries[0]));
1293         if (!ads_entries) {
1294                 ERROR("Could not allocate memory for %"PRIu16" "
1295                       "alternate data stream entries", num_ads);
1296                 return WIMLIB_ERR_NOMEM;
1297         }
1298
1299         for (u16 i = 0; i < num_ads; i++) {
1300                 struct wim_ads_entry *cur_entry;
1301                 u64 length;
1302                 u64 length_no_padding;
1303                 u64 total_length;
1304                 const u8 *p_save = p;
1305
1306                 cur_entry = &ads_entries[i];
1307
1308         #ifdef WITH_FUSE
1309                 ads_entries[i].stream_id = i + 1;
1310         #endif
1311
1312                 /* Read the base stream entry, excluding the stream name. */
1313                 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
1314                         ERROR("Stream entries go past end of metadata resource");
1315                         ERROR("(remaining_size = %"PRIu64")", remaining_size);
1316                         ret = WIMLIB_ERR_INVALID_DENTRY;
1317                         goto out_free_ads_entries;
1318                 }
1319
1320                 p = get_u64(p, &length);
1321                 p += 8; /* Skip the reserved field */
1322                 p = get_bytes(p, SHA1_HASH_SIZE, cur_entry->hash);
1323                 p = get_u16(p, &cur_entry->stream_name_nbytes);
1324
1325                 cur_entry->stream_name = NULL;
1326
1327                 /* Length including neither the null terminator nor the padding
1328                  * */
1329                 length_no_padding = WIM_ADS_ENTRY_DISK_SIZE +
1330                                     cur_entry->stream_name_nbytes;
1331
1332                 /* Length including the null terminator and the padding */
1333                 total_length = ((length_no_padding + 2) + 7) & ~7;
1334
1335                 wimlib_assert(total_length == ads_entry_total_length(cur_entry));
1336
1337                 if (remaining_size < length_no_padding) {
1338                         ERROR("Stream entries go past end of metadata resource");
1339                         ERROR("(remaining_size = %"PRIu64" bytes, "
1340                               "length_no_padding = %"PRIu64" bytes)",
1341                               remaining_size, length_no_padding);
1342                         ret = WIMLIB_ERR_INVALID_DENTRY;
1343                         goto out_free_ads_entries;
1344                 }
1345
1346                 /* The @length field in the on-disk ADS entry is expected to be
1347                  * equal to @total_length, which includes all of the entry and
1348                  * the padding that follows it to align the next ADS entry to an
1349                  * 8-byte boundary.  However, to be safe, we'll accept the
1350                  * length field as long as it's not less than the un-padded
1351                  * total length and not more than the padded total length. */
1352                 if (length < length_no_padding || length > total_length) {
1353                         ERROR("Stream entry has unexpected length "
1354                               "field (length field = %"PRIu64", "
1355                               "unpadded total length = %"PRIu64", "
1356                               "padded total length = %"PRIu64")",
1357                               length, length_no_padding, total_length);
1358                         ret = WIMLIB_ERR_INVALID_DENTRY;
1359                         goto out_free_ads_entries;
1360                 }
1361
1362                 if (cur_entry->stream_name_nbytes) {
1363                         cur_entry->stream_name = MALLOC(cur_entry->stream_name_nbytes + 2);
1364                         if (!cur_entry->stream_name) {
1365                                 ret = WIMLIB_ERR_NOMEM;
1366                                 goto out_free_ads_entries;
1367                         }
1368                         get_bytes(p, cur_entry->stream_name_nbytes,
1369                                   cur_entry->stream_name);
1370                         cur_entry->stream_name[cur_entry->stream_name_nbytes / 2] = 0;
1371                         replace_forbidden_characters(cur_entry->stream_name);
1372                 }
1373                 /* It's expected that the size of every ADS entry is a multiple
1374                  * of 8.  However, to be safe, I'm allowing the possibility of
1375                  * an ADS entry at the very end of the metadata resource ending
1376                  * un-aligned.  So although we still need to increment the input
1377                  * pointer by @total_length to reach the next ADS entry, it's
1378                  * possible that less than @total_length is actually remaining
1379                  * in the metadata resource. We should set the remaining size to
1380                  * 0 bytes if this happens. */
1381                 p = p_save + total_length;
1382                 if (remaining_size < total_length)
1383                         remaining_size = 0;
1384                 else
1385                         remaining_size -= total_length;
1386         }
1387         inode->i_ads_entries = ads_entries;
1388 #ifdef WITH_FUSE
1389         inode->i_next_stream_id = inode->i_num_ads + 1;
1390 #endif
1391         return 0;
1392 out_free_ads_entries:
1393         for (u16 i = 0; i < num_ads; i++)
1394                 destroy_ads_entry(&ads_entries[i]);
1395         FREE(ads_entries);
1396         return ret;
1397 }
1398
1399 /*
1400  * Reads a WIM directory entry, including all alternate data stream entries that
1401  * follow it, from the WIM image's metadata resource.
1402  *
1403  * @metadata_resource:  Buffer containing the uncompressed metadata resource.
1404  * @metadata_resource_len:   Length of the metadata resource.
1405  * @offset:     Offset of this directory entry in the metadata resource.
1406  * @dentry:     A `struct wim_dentry' that will be filled in by this function.
1407  *
1408  * Return 0 on success or nonzero on failure.  On failure, @dentry will have
1409  * been modified, but it will not be left with pointers to any allocated
1410  * buffers.  On success, the dentry->length field must be examined.  If zero,
1411  * this was a special "end of directory" dentry and not a real dentry.  If
1412  * nonzero, this was a real dentry.
1413  */
1414 int
1415 read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
1416             u64 offset, struct wim_dentry *dentry)
1417 {
1418         const u8 *p;
1419         u64 calculated_size;
1420         utf16lechar *file_name = NULL;
1421         utf16lechar *short_name = NULL;
1422         u16 short_name_nbytes;
1423         u16 file_name_nbytes;
1424         int ret;
1425         struct wim_inode *inode = NULL;
1426
1427         dentry_common_init(dentry);
1428
1429         /*Make sure the dentry really fits into the metadata resource.*/
1430         if (offset + 8 > metadata_resource_len || offset + 8 < offset) {
1431                 ERROR("Directory entry starting at %"PRIu64" ends past the "
1432                       "end of the metadata resource (size %"PRIu64")",
1433                       offset, metadata_resource_len);
1434                 return WIMLIB_ERR_INVALID_DENTRY;
1435         }
1436
1437         /* Before reading the whole dentry, we need to read just the length.
1438          * This is because a dentry of length 8 (that is, just the length field)
1439          * terminates the list of sibling directory entries. */
1440
1441         p = get_u64(&metadata_resource[offset], &dentry->length);
1442
1443         /* A zero length field (really a length of 8, since that's how big the
1444          * directory entry is...) indicates that this is the end of directory
1445          * dentry.  We do not read it into memory as an actual dentry, so just
1446          * return successfully in that case. */
1447         if (dentry->length == 0)
1448                 return 0;
1449
1450         /* If the dentry does not overflow the metadata resource buffer and is
1451          * not too short, read the rest of it (excluding the alternate data
1452          * streams, but including the file name and short name variable-length
1453          * fields) into memory. */
1454         if (offset + dentry->length >= metadata_resource_len
1455             || offset + dentry->length < offset)
1456         {
1457                 ERROR("Directory entry at offset %"PRIu64" and with size "
1458                       "%"PRIu64" ends past the end of the metadata resource "
1459                       "(size %"PRIu64")",
1460                       offset, dentry->length, metadata_resource_len);
1461                 return WIMLIB_ERR_INVALID_DENTRY;
1462         }
1463
1464         if (dentry->length < WIM_DENTRY_DISK_SIZE) {
1465                 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
1466                       dentry->length);
1467                 return WIMLIB_ERR_INVALID_DENTRY;
1468         }
1469
1470         inode = new_timeless_inode();
1471         if (!inode)
1472                 return WIMLIB_ERR_NOMEM;
1473
1474         p = get_u32(p, &inode->i_attributes);
1475         p = get_u32(p, (u32*)&inode->i_security_id);
1476         p = get_u64(p, &dentry->subdir_offset);
1477
1478         /* 2 unused fields */
1479         p += 2 * sizeof(u64);
1480         /*p = get_u64(p, &dentry->unused1);*/
1481         /*p = get_u64(p, &dentry->unused2);*/
1482
1483         p = get_u64(p, &inode->i_creation_time);
1484         p = get_u64(p, &inode->i_last_access_time);
1485         p = get_u64(p, &inode->i_last_write_time);
1486
1487         p = get_bytes(p, SHA1_HASH_SIZE, inode->i_hash);
1488
1489         /* I don't know what's going on here.  It seems like M$ screwed up the
1490          * reparse points, then put the fields in the same place and didn't
1491          * document it.  */
1492         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1493                 p = get_u32(p, &inode->i_rp_unknown_1);
1494                 p = get_u32(p, &inode->i_reparse_tag);
1495                 p = get_u16(p, &inode->i_rp_unknown_2);
1496                 p = get_u16(p, &inode->i_not_rpfixed);
1497         } else {
1498                 p = get_u32(p, &inode->i_rp_unknown_1);
1499                 p = get_u64(p, &inode->i_ino);
1500         }
1501
1502         /* By the way, the reparse_reserved field does not actually exist (at
1503          * least when the file is not a reparse point) */
1504
1505         p = get_u16(p, &inode->i_num_ads);
1506
1507         p = get_u16(p, &short_name_nbytes);
1508         p = get_u16(p, &file_name_nbytes);
1509
1510         /* We now know the length of the file name and short name.  Make sure
1511          * the length of the dentry is large enough to actually hold them.
1512          *
1513          * The calculated length here is unaligned to allow for the possibility
1514          * that the dentry->length names an unaligned length, although this
1515          * would be unexpected. */
1516         calculated_size = __dentry_correct_length_unaligned(file_name_nbytes,
1517                                                             short_name_nbytes);
1518
1519         if (dentry->length < calculated_size) {
1520                 ERROR("Unexpected end of directory entry! (Expected "
1521                       "at least %"PRIu64" bytes, got %"PRIu64" bytes. "
1522                       "short_name_nbytes = %hu, file_name_nbytes = %hu)",
1523                       calculated_size, dentry->length,
1524                       short_name_nbytes, file_name_nbytes);
1525                 ret = WIMLIB_ERR_INVALID_DENTRY;
1526                 goto out_free_inode;
1527         }
1528
1529         /* Read the filename if present.  Note: if the filename is empty, there
1530          * is no null terminator following it. */
1531         if (file_name_nbytes) {
1532                 file_name = MALLOC(file_name_nbytes + 2);
1533                 if (!file_name) {
1534                         ERROR("Failed to allocate %d bytes for dentry file name",
1535                               file_name_nbytes + 2);
1536                         ret = WIMLIB_ERR_NOMEM;
1537                         goto out_free_inode;
1538                 }
1539                 p = get_bytes(p, file_name_nbytes + 2, file_name);
1540                 if (file_name[file_name_nbytes / 2] != 0) {
1541                         file_name[file_name_nbytes / 2] = 0;
1542                         WARNING("File name in WIM dentry \"%"WS"\" is not "
1543                                 "null-terminated!", file_name);
1544                 }
1545                 replace_forbidden_characters(file_name);
1546         }
1547
1548         /* Align the calculated size */
1549         calculated_size = (calculated_size + 7) & ~7;
1550
1551         if (dentry->length > calculated_size) {
1552                 /* Weird; the dentry says it's longer than it should be.  Note
1553                  * that the length field does NOT include the size of the
1554                  * alternate stream entries. */
1555
1556                 /* Strangely, some directory entries inexplicably have a little
1557                  * over 70 bytes of extra data.  The exact amount of data seems
1558                  * to be 72 bytes, but it is aligned on the next 8-byte
1559                  * boundary.  It does NOT seem to be alternate data stream
1560                  * entries.  Here's an example of the aligned data:
1561                  *
1562                  * 01000000 40000000 6c786bba c58ede11 b0bb0026 1870892a b6adb76f
1563                  * e63a3e46 8fca8653 0d2effa1 6c786bba c58ede11 b0bb0026 1870892a
1564                  * 00000000 00000000 00000000 00000000
1565                  *
1566                  * Here's one interpretation of how the data is laid out.
1567                  *
1568                  * struct unknown {
1569                  *      u32 field1; (always 0x00000001)
1570                  *      u32 field2; (always 0x40000000)
1571                  *      u8  data[48]; (???)
1572                  *      u64 reserved1; (always 0)
1573                  *      u64 reserved2; (always 0)
1574                  * };*/
1575                 /*DEBUG("Dentry for file or directory `%"WS"' has %"PRIu64" "*/
1576                       /*"extra bytes of data", file_name,*/
1577                       /*dentry->length - calculated_size);*/
1578         }
1579
1580         /* Read the short filename if present.  Note: if there is no short
1581          * filename, there is no null terminator following it. */
1582         if (short_name_nbytes) {
1583                 short_name = MALLOC(short_name_nbytes + 2);
1584                 if (!short_name) {
1585                         ERROR("Failed to allocate %d bytes for dentry short name",
1586                               short_name_nbytes + 2);
1587                         ret = WIMLIB_ERR_NOMEM;
1588                         goto out_free_file_name;
1589                 }
1590                 p = get_bytes(p, short_name_nbytes + 2, short_name);
1591                 if (short_name[short_name_nbytes / 2] != 0) {
1592                         short_name[short_name_nbytes / 2] = 0;
1593                         WARNING("Short name in WIM dentry \"%"WS"\" is not "
1594                                 "null-terminated!", file_name);
1595                 }
1596                 replace_forbidden_characters(short_name);
1597         }
1598
1599         /*
1600          * Read the alternate data streams, if present.  dentry->num_ads tells
1601          * us how many they are, and they will directly follow the dentry
1602          * on-disk.
1603          *
1604          * Note that each alternate data stream entry begins on an 8-byte
1605          * aligned boundary, and the alternate data stream entries are NOT
1606          * included in the dentry->length field for some reason.
1607          */
1608         if (inode->i_num_ads != 0) {
1609
1610                 /* Trying different lengths is just a hack to make sure we have
1611                  * a chance of reading the ADS entries correctly despite the
1612                  * poor documentation. */
1613
1614                 if (calculated_size != dentry->length) {
1615                         WARNING("Trying calculated dentry length (%"PRIu64") "
1616                                 "instead of dentry->length field (%"PRIu64") "
1617                                 "to read ADS entries",
1618                                 calculated_size, dentry->length);
1619                 }
1620                 u64 lengths_to_try[3] = {calculated_size,
1621                                          (dentry->length + 7) & ~7,
1622                                          dentry->length};
1623                 ret = WIMLIB_ERR_INVALID_DENTRY;
1624                 for (size_t i = 0; i < ARRAY_LEN(lengths_to_try); i++) {
1625                         if (lengths_to_try[i] > metadata_resource_len - offset)
1626                                 continue;
1627                         ret = read_ads_entries(&metadata_resource[offset + lengths_to_try[i]],
1628                                                inode,
1629                                                metadata_resource_len - offset - lengths_to_try[i]);
1630                         if (ret == 0)
1631                                 goto out;
1632                 }
1633                 ERROR("Failed to read alternate data stream "
1634                       "entries of WIM dentry \"%"WS"\"", file_name);
1635                 goto out_free_short_name;
1636         }
1637 out:
1638         /* We've read all the data for this dentry.  Set the names and their
1639          * lengths, and we've done. */
1640         dentry->d_inode           = inode;
1641         dentry->file_name         = file_name;
1642         dentry->short_name        = short_name;
1643         dentry->file_name_nbytes  = file_name_nbytes;
1644         dentry->short_name_nbytes = short_name_nbytes;
1645         return 0;
1646 out_free_short_name:
1647         FREE(short_name);
1648 out_free_file_name:
1649         FREE(file_name);
1650 out_free_inode:
1651         free_inode(inode);
1652         return ret;
1653 }
1654
1655 /* Reads the children of a dentry, and all their children, ..., etc. from the
1656  * metadata resource and into the dentry tree.
1657  *
1658  * @metadata_resource:  An array that contains the uncompressed metadata
1659  *                      resource for the WIM file.
1660  *
1661  * @metadata_resource_len:  The length of the uncompressed metadata resource, in
1662  *                          bytes.
1663  *
1664  * @dentry:     A pointer to a `struct wim_dentry' that is the root of the directory
1665  *              tree and has already been read from the metadata resource.  It
1666  *              does not need to be the real root because this procedure is
1667  *              called recursively.
1668  *
1669  * Returns zero on success; nonzero on failure.
1670  */
1671 int
1672 read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1673                  struct wim_dentry *dentry)
1674 {
1675         u64 cur_offset = dentry->subdir_offset;
1676         struct wim_dentry *child;
1677         struct wim_dentry cur_child;
1678         int ret;
1679
1680         /*
1681          * If @dentry has no child dentries, nothing more needs to be done for
1682          * this branch.  This is the case for regular files, symbolic links, and
1683          * *possibly* empty directories (although an empty directory may also
1684          * have one child dentry that is the special end-of-directory dentry)
1685          */
1686         if (cur_offset == 0)
1687                 return 0;
1688
1689         /* Find and read all the children of @dentry. */
1690         while (1) {
1691
1692                 /* Read next child of @dentry into @cur_child. */
1693                 ret = read_dentry(metadata_resource, metadata_resource_len,
1694                                   cur_offset, &cur_child);
1695                 if (ret != 0)
1696                         break;
1697
1698                 /* Check for end of directory. */
1699                 if (cur_child.length == 0)
1700                         break;
1701
1702                 /* Not end of directory.  Allocate this child permanently and
1703                  * link it to the parent and previous child. */
1704                 child = MALLOC(sizeof(struct wim_dentry));
1705                 if (!child) {
1706                         ERROR("Failed to allocate %zu bytes for new dentry",
1707                               sizeof(struct wim_dentry));
1708                         ret = WIMLIB_ERR_NOMEM;
1709                         break;
1710                 }
1711                 memcpy(child, &cur_child, sizeof(struct wim_dentry));
1712                 dentry_add_child(dentry, child);
1713                 inode_add_dentry(child, child->d_inode);
1714
1715                 /* If there are children of this child, call this procedure
1716                  * recursively. */
1717                 if (child->subdir_offset != 0) {
1718                         ret = read_dentry_tree(metadata_resource,
1719                                                metadata_resource_len, child);
1720                         if (ret != 0)
1721                                 break;
1722                 }
1723
1724                 /* Advance to the offset of the next child.  Note: We need to
1725                  * advance by the TOTAL length of the dentry, not by the length
1726                  * child->length, which although it does take into account the
1727                  * padding, it DOES NOT take into account alternate stream
1728                  * entries. */
1729                 cur_offset += dentry_total_length(child);
1730         }
1731         return ret;
1732 }
1733
1734 /*
1735  * Writes a WIM dentry to an output buffer.
1736  *
1737  * @dentry:  The dentry structure.
1738  * @p:       The memory location to write the data to.
1739  * @return:  Pointer to the byte after the last byte we wrote as part of the
1740  *              dentry.
1741  */
1742 static u8 *
1743 write_dentry(const struct wim_dentry *dentry, u8 *p)
1744 {
1745         u8 *orig_p = p;
1746         const u8 *hash;
1747         const struct wim_inode *inode = dentry->d_inode;
1748
1749         /* We calculate the correct length of the dentry ourselves because the
1750          * dentry->length field may been set to an unexpected value from when we
1751          * read the dentry in (for example, there may have been unknown data
1752          * appended to the end of the dentry...) */
1753         u64 length = dentry_correct_length(dentry);
1754
1755         p = put_u64(p, length);
1756         p = put_u32(p, inode->i_attributes);
1757         p = put_u32(p, inode->i_security_id);
1758         p = put_u64(p, dentry->subdir_offset);
1759         p = put_u64(p, 0); /* unused1 */
1760         p = put_u64(p, 0); /* unused2 */
1761         p = put_u64(p, inode->i_creation_time);
1762         p = put_u64(p, inode->i_last_access_time);
1763         p = put_u64(p, inode->i_last_write_time);
1764         hash = inode_stream_hash(inode, 0);
1765         p = put_bytes(p, SHA1_HASH_SIZE, hash);
1766         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1767                 p = put_u32(p, 0);
1768                 p = put_u32(p, inode->i_reparse_tag);
1769                 p = put_u16(p, 0);
1770                 p = put_u16(p, inode->i_not_rpfixed);
1771         } else {
1772                 u64 link_group_id;
1773                 p = put_u32(p, 0);
1774                 if (inode->i_nlink == 1)
1775                         link_group_id = 0;
1776                 else
1777                         link_group_id = inode->i_ino;
1778                 p = put_u64(p, link_group_id);
1779         }
1780         p = put_u16(p, inode->i_num_ads);
1781         p = put_u16(p, dentry->short_name_nbytes);
1782         p = put_u16(p, dentry->file_name_nbytes);
1783         if (dentry_has_long_name(dentry)) {
1784                 p = put_bytes(p, dentry->file_name_nbytes + 2,
1785                               dentry->file_name);
1786         }
1787         if (dentry_has_short_name(dentry)) {
1788                 p = put_bytes(p, dentry->short_name_nbytes + 2,
1789                               dentry->short_name);
1790         }
1791
1792         /* Align to 8-byte boundary */
1793         wimlib_assert(length >= (p - orig_p) && length - (p - orig_p) <= 7);
1794         p = put_zeroes(p, length - (p - orig_p));
1795
1796         /* Write the alternate data streams, if there are any.  Please see
1797          * read_ads_entries() for comments about the format of the on-disk
1798          * alternate data stream entries. */
1799         for (u16 i = 0; i < inode->i_num_ads; i++) {
1800                 p = put_u64(p, ads_entry_total_length(&inode->i_ads_entries[i]));
1801                 p = put_u64(p, 0); /* Unused */
1802                 hash = inode_stream_hash(inode, i + 1);
1803                 p = put_bytes(p, SHA1_HASH_SIZE, hash);
1804                 p = put_u16(p, inode->i_ads_entries[i].stream_name_nbytes);
1805                 if (inode->i_ads_entries[i].stream_name_nbytes) {
1806                         p = put_bytes(p,
1807                                       inode->i_ads_entries[i].stream_name_nbytes + 2,
1808                                       inode->i_ads_entries[i].stream_name);
1809                 }
1810                 p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1811         }
1812         wimlib_assert(p - orig_p == __dentry_total_length(dentry, length));
1813         return p;
1814 }
1815
1816 static int
1817 write_dentry_cb(struct wim_dentry *dentry, void *_p)
1818 {
1819         u8 **p = _p;
1820         *p = write_dentry(dentry, *p);
1821         return 0;
1822 }
1823
1824 static u8 *
1825 write_dentry_tree_recursive(const struct wim_dentry *parent, u8 *p);
1826
1827 static int
1828 write_dentry_tree_recursive_cb(struct wim_dentry *dentry, void *_p)
1829 {
1830         u8 **p = _p;
1831         *p = write_dentry_tree_recursive(dentry, *p);
1832         return 0;
1833 }
1834
1835 /* Recursive function that writes a dentry tree rooted at @parent, not including
1836  * @parent itself, which has already been written. */
1837 static u8 *
1838 write_dentry_tree_recursive(const struct wim_dentry *parent, u8 *p)
1839 {
1840         /* Nothing to do if this dentry has no children. */
1841         if (parent->subdir_offset == 0)
1842                 return p;
1843
1844         /* Write child dentries and end-of-directory entry.
1845          *
1846          * Note: we need to write all of this dentry's children before
1847          * recursively writing the directory trees rooted at each of the child
1848          * dentries, since the on-disk dentries for a dentry's children are
1849          * always located at consecutive positions in the metadata resource! */
1850         for_dentry_child(parent, write_dentry_cb, &p);
1851
1852         /* write end of directory entry */
1853         p = put_u64(p, 0);
1854
1855         /* Recurse on children. */
1856         for_dentry_child(parent, write_dentry_tree_recursive_cb, &p);
1857         return p;
1858 }
1859
1860 /* Writes a directory tree to the metadata resource.
1861  *
1862  * @root:       Root of the dentry tree.
1863  * @p:          Pointer to a buffer with enough space for the dentry tree.
1864  *
1865  * Returns pointer to the byte after the last byte we wrote.
1866  */
1867 u8 *
1868 write_dentry_tree(const struct wim_dentry *root, u8 *p)
1869 {
1870         DEBUG("Writing dentry tree.");
1871         wimlib_assert(dentry_is_root(root));
1872
1873         /* If we're the root dentry, we have no parent that already
1874          * wrote us, so we need to write ourselves. */
1875         p = write_dentry(root, p);
1876
1877         /* Write end of directory entry after the root dentry just to be safe;
1878          * however the root dentry obviously cannot have any siblings. */
1879         p = put_u64(p, 0);
1880
1881         /* Recursively write the rest of the dentry tree. */
1882         return write_dentry_tree_recursive(root, p);
1883 }