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   1 /*
   2  * lookup_table.c
   3  *
   4  * Lookup table, implemented as a hash table, that maps SHA1 message digests to
   5  * data streams; plus code to read and write the corresponding on-disk data.
   6  */
   7
   8 /*
   9  * Copyright (C) 2012, 2013 Eric Biggers
  10  *
  11  * This file is part of wimlib, a library for working with WIM files.
  12  *
  13  * wimlib is free software; you can redistribute it and/or modify it under the
  14  * terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 3 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #  include "config.h"
  29 #endif
  30
  31 #include "wimlib/assert.h"
  32 #include "wimlib/endianness.h"
  33 #include "wimlib/error.h"
  34 #include "wimlib/lookup_table.h"
  35 #include "wimlib/metadata.h"
  36 #include "wimlib/ntfs_3g.h"
  37 #include "wimlib/resource.h"
  38 #include "wimlib/util.h"
  39 #include "wimlib/write.h"
  40
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h> /* for unlink()  */
  44
  45 /* WIM lookup table:
  46  *
  47  * This is a logical mapping from SHA1 message digests to the data streams
  48  * contained in a WIM.
  49  *
  50  * Here it is implemented as a hash table.
  51  *
  52  * Note: Everything will break horribly if there is a SHA1 collision.
  53  */
  54 struct wim_lookup_table {
  55         struct hlist_head *array;
  56         size_t num_entries;
  57         size_t capacity;
  58 };
  59
  60 struct wim_lookup_table *
  61 new_lookup_table(size_t capacity)
  62 {
  63         struct wim_lookup_table *table;
  64         struct hlist_head *array;
  65
  66         table = MALLOC(sizeof(struct wim_lookup_table));
  67         if (table == NULL)
  68                 goto oom;
  69
  70         array = CALLOC(capacity, sizeof(array[0]));
  71         if (array == NULL) {
  72                 FREE(table);
  73                 goto oom;
  74         }
  75
  76         table->num_entries = 0;
  77         table->capacity = capacity;
  78         table->array = array;
  79         return table;
  80
  81 oom:
  82         ERROR("Failed to allocate memory for lookup table "
  83               "with capacity %zu", capacity);
  84         return NULL;
  85 }
  86
  87 static int
  88 do_free_lookup_table_entry(struct wim_lookup_table_entry *entry, void *ignore)
  89 {
  90         free_lookup_table_entry(entry);
  91         return 0;
  92 }
  93
  94 void
  95 free_lookup_table(struct wim_lookup_table *table)
  96 {
  97         DEBUG("Freeing lookup table.");
  98         if (table == NULL)
  99                 return;
 100
 101         if (table->array) {
 102                 for_lookup_table_entry(table,
 103                                        do_free_lookup_table_entry,
 104                                        NULL);
 105                 FREE(table->array);
 106         }
 107         FREE(table);
 108 }
 109
 110 struct wim_lookup_table_entry *
 111 new_lookup_table_entry(void)
 112 {
 113         struct wim_lookup_table_entry *lte;
 114
 115         lte = CALLOC(1, sizeof(struct wim_lookup_table_entry));
 116         if (lte == NULL)
 117                 return NULL;
 118
 119         lte->refcnt = 1;
 120
 121         /* lte->resource_location = RESOURCE_NONEXISTENT  */
 122         BUILD_BUG_ON(RESOURCE_NONEXISTENT != 0);
 123
 124         return lte;
 125 }
 126
 127 struct wim_lookup_table_entry *
 128 clone_lookup_table_entry(const struct wim_lookup_table_entry *old)
 129 {
 130         struct wim_lookup_table_entry *new;
 131
 132         new = memdup(old, sizeof(struct wim_lookup_table_entry));
 133         if (new == NULL)
 134                 return NULL;
 135
 136         new->extracted_file = NULL;
 137         switch (new->resource_location) {
 138         case RESOURCE_IN_WIM:
 139                 list_add(&new->rspec_node, &new->rspec->stream_list);
 140                 break;
 141
 142         case RESOURCE_IN_FILE_ON_DISK:
 143 #ifdef __WIN32__
 144         case RESOURCE_WIN32_ENCRYPTED:
 145 #endif
 146 #ifdef WITH_FUSE
 147         case RESOURCE_IN_STAGING_FILE:
 148                 BUILD_BUG_ON((void*)&old->file_on_disk !=
 149                              (void*)&old->staging_file_name);
 150 #endif
 151                 new->file_on_disk = TSTRDUP(old->file_on_disk);
 152                 if (new->file_on_disk == NULL)
 153                         goto out_free;
 154                 break;
 155         case RESOURCE_IN_ATTACHED_BUFFER:
 156                 new->attached_buffer = memdup(old->attached_buffer, old->size);
 157                 if (new->attached_buffer == NULL)
 158                         goto out_free;
 159                 break;
 160 #ifdef WITH_NTFS_3G
 161         case RESOURCE_IN_NTFS_VOLUME:
 162                 if (old->ntfs_loc) {
 163                         struct ntfs_location *loc;
 164                         loc = memdup(old->ntfs_loc, sizeof(struct ntfs_location));
 165                         if (loc == NULL)
 166                                 goto out_free;
 167                         loc->path = NULL;
 168                         loc->stream_name = NULL;
 169                         new->ntfs_loc = loc;
 170                         loc->path = STRDUP(old->ntfs_loc->path);
 171                         if (loc->path == NULL)
 172                                 goto out_free;
 173                         if (loc->stream_name_nchars != 0) {
 174                                 loc->stream_name = memdup(old->ntfs_loc->stream_name,
 175                                                           loc->stream_name_nchars * 2);
 176                                 if (loc->stream_name == NULL)
 177                                         goto out_free;
 178                         }
 179                 }
 180                 break;
 181 #endif
 182         default:
 183                 break;
 184         }
 185         return new;
 186
 187 out_free:
 188         free_lookup_table_entry(new);
 189         return NULL;
 190 }
 191
 192 void
 193 lte_put_resource(struct wim_lookup_table_entry *lte)
 194 {
 195         switch (lte->resource_location) {
 196         case RESOURCE_IN_WIM:
 197                 list_del(&lte->rspec_node);
 198                 if (list_empty(&lte->rspec->stream_list))
 199                         FREE(lte->rspec);
 200                 break;
 201         case RESOURCE_IN_FILE_ON_DISK:
 202 #ifdef __WIN32__
 203         case RESOURCE_WIN32_ENCRYPTED:
 204 #endif
 205 #ifdef WITH_FUSE
 206         case RESOURCE_IN_STAGING_FILE:
 207                 BUILD_BUG_ON((void*)&lte->file_on_disk !=
 208                              (void*)&lte->staging_file_name);
 209 #endif
 210         case RESOURCE_IN_ATTACHED_BUFFER:
 211                 BUILD_BUG_ON((void*)&lte->file_on_disk !=
 212                              (void*)&lte->attached_buffer);
 213                 FREE(lte->file_on_disk);
 214                 break;
 215 #ifdef WITH_NTFS_3G
 216         case RESOURCE_IN_NTFS_VOLUME:
 217                 if (lte->ntfs_loc) {
 218                         FREE(lte->ntfs_loc->path);
 219                         FREE(lte->ntfs_loc->stream_name);
 220                         FREE(lte->ntfs_loc);
 221                 }
 222                 break;
 223 #endif
 224         default:
 225                 break;
 226         }
 227 }
 228
 229 void
 230 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 231 {
 232         if (lte) {
 233                 lte_put_resource(lte);
 234                 FREE(lte);
 235         }
 236 }
 237
 238 /* Should this stream be retained even if it has no references?  */
 239 static bool
 240 should_retain_lte(const struct wim_lookup_table_entry *lte)
 241 {
 242         return lte->resource_location == RESOURCE_IN_WIM;
 243 }
 244
 245 static void
 246 finalize_lte(struct wim_lookup_table_entry *lte)
 247 {
 248         if (!should_retain_lte(lte))
 249                 free_lookup_table_entry(lte);
 250 }
 251
 252 /*
 253  * Decrements the reference count for the lookup table entry @lte, which must be
 254  * inserted in the stream lookup table @table.
 255  *
 256  * If the reference count reaches 0, this may cause @lte to be destroyed.
 257  * However, we may retain entries with 0 reference count.  This does not affect
 258  * correctness, but it prevents the entries for valid streams in a WIM archive,
 259  * which will continue to be present after appending to the file, from being
 260  * lost merely because we dropped all references to them.
 261  */
 262 void
 263 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 264                      struct wim_lookup_table *table)
 265 {
 266         wimlib_assert(lte->refcnt != 0);
 267
 268         if (--lte->refcnt == 0) {
 269                 if (lte->unhashed) {
 270                         list_del(&lte->unhashed_list);
 271                 #ifdef WITH_FUSE
 272                         /* If the stream has been extracted to a staging file
 273                          * for a FUSE mount, unlink the staging file.  (Note
 274                          * that there still may be open file descriptors to it.)
 275                          * */
 276                         if (lte->resource_location == RESOURCE_IN_STAGING_FILE)
 277                                 unlink(lte->staging_file_name);
 278                 #endif
 279                 } else {
 280                         if (!should_retain_lte(lte))
 281                                 lookup_table_unlink(table, lte);
 282                 }
 283
 284                 /* If FUSE mounts are enabled, we don't actually free the entry
 285                  * until the last file descriptor has been closed by
 286                  * lte_decrement_num_opened_fds().  */
 287 #ifdef WITH_FUSE
 288                 if (lte->num_opened_fds == 0)
 289 #endif
 290                         finalize_lte(lte);
 291         }
 292 }
 293
 294 #ifdef WITH_FUSE
 295 void
 296 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 297 {
 298         wimlib_assert(lte->num_opened_fds != 0);
 299
 300         if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 301                 finalize_lte(lte);
 302 }
 303 #endif
 304
 305 static void
 306 lookup_table_insert_raw(struct wim_lookup_table *table,
 307                         struct wim_lookup_table_entry *lte)
 308 {
 309         size_t i = lte->hash_short % table->capacity;
 310
 311         hlist_add_head(&lte->hash_list, &table->array[i]);
 312 }
 313
 314 static void
 315 enlarge_lookup_table(struct wim_lookup_table *table)
 316 {
 317         size_t old_capacity, new_capacity;
 318         struct hlist_head *old_array, *new_array;
 319         struct wim_lookup_table_entry *lte;
 320         struct hlist_node *cur, *tmp;
 321         size_t i;
 322
 323         old_capacity = table->capacity;
 324         new_capacity = old_capacity * 2;
 325         new_array = CALLOC(new_capacity, sizeof(struct hlist_head));
 326         if (new_array == NULL)
 327                 return;
 328         old_array = table->array;
 329         table->array = new_array;
 330         table->capacity = new_capacity;
 331
 332         for (i = 0; i < old_capacity; i++) {
 333                 hlist_for_each_entry_safe(lte, cur, tmp, &old_array[i], hash_list) {
 334                         hlist_del(&lte->hash_list);
 335                         lookup_table_insert_raw(table, lte);
 336                 }
 337         }
 338         FREE(old_array);
 339 }
 340
 341 /* Inserts an entry into the lookup table.  */
 342 void
 343 lookup_table_insert(struct wim_lookup_table *table,
 344                     struct wim_lookup_table_entry *lte)
 345 {
 346         lookup_table_insert_raw(table, lte);
 347         if (++table->num_entries > table->capacity)
 348                 enlarge_lookup_table(table);
 349 }
 350
 351 /* Unlinks a lookup table entry from the table; does not free it.  */
 352 void
 353 lookup_table_unlink(struct wim_lookup_table *table,
 354                     struct wim_lookup_table_entry *lte)
 355 {
 356         wimlib_assert(!lte->unhashed);
 357         wimlib_assert(table->num_entries != 0);
 358
 359         hlist_del(&lte->hash_list);
 360         table->num_entries--;
 361 }
 362
 363 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 364  * lookup table, or NULL if there is none.  */
 365 struct wim_lookup_table_entry *
 366 lookup_stream(const struct wim_lookup_table *table, const u8 hash[])
 367 {
 368         size_t i;
 369         struct wim_lookup_table_entry *lte;
 370         struct hlist_node *pos;
 371
 372         i = *(size_t*)hash % table->capacity;
 373         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 374                 if (hashes_equal(hash, lte->hash))
 375                         return lte;
 376         return NULL;
 377 }
 378
 379 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 380  * return nonzero if any call to the function returns nonzero. */
 381 int
 382 for_lookup_table_entry(struct wim_lookup_table *table,
 383                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 384                        void *arg)
 385 {
 386         struct wim_lookup_table_entry *lte;
 387         struct hlist_node *pos, *tmp;
 388         int ret;
 389
 390         for (size_t i = 0; i < table->capacity; i++) {
 391                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 392                                           hash_list)
 393                 {
 394                         ret = visitor(lte, arg);
 395                         if (ret)
 396                                 return ret;
 397                 }
 398         }
 399         return 0;
 400 }
 401
 402 /* qsort() callback that sorts streams (represented by `struct
 403  * wim_lookup_table_entry's) into an order optimized for reading.
 404  *
 405  * Sorting is done primarily by resource location, then secondarily by a
 406  * per-resource location order.  For example, resources in WIM files are sorted
 407  * primarily by part number, then secondarily by offset, as to implement optimal
 408  * reading of either a standalone or split WIM.  */
 409 static int
 410 cmp_streams_by_sequential_order(const void *p1, const void *p2)
 411 {
 412         const struct wim_lookup_table_entry *lte1, *lte2;
 413         int v;
 414         WIMStruct *wim1, *wim2;
 415
 416         lte1 = *(const struct wim_lookup_table_entry**)p1;
 417         lte2 = *(const struct wim_lookup_table_entry**)p2;
 418
 419         v = (int)lte1->resource_location - (int)lte2->resource_location;
 420
 421         /* Different resource locations?  */
 422         if (v)
 423                 return v;
 424
 425         switch (lte1->resource_location) {
 426         case RESOURCE_IN_WIM:
 427                 wim1 = lte1->rspec->wim;
 428                 wim2 = lte2->rspec->wim;
 429
 430                 /* Different (possibly split) WIMs?  */
 431                 if (wim1 != wim2) {
 432                         v = memcmp(wim1->hdr.guid, wim2->hdr.guid, WIM_GID_LEN);
 433                         if (v)
 434                                 return v;
 435                 }
 436
 437                 /* Different part numbers in the same WIM?  */
 438                 v = (int)wim1->hdr.part_number - (int)wim2->hdr.part_number;
 439                 if (v)
 440                         return v;
 441
 442                 if (lte1->rspec->offset_in_wim != lte2->rspec->offset_in_wim)
 443                         return cmp_u64(lte1->rspec->offset_in_wim,
 444                                        lte2->rspec->offset_in_wim);
 445
 446                 return cmp_u64(lte1->offset_in_res, lte2->offset_in_res);
 447
 448         case RESOURCE_IN_FILE_ON_DISK:
 449 #ifdef WITH_FUSE
 450         case RESOURCE_IN_STAGING_FILE:
 451 #endif
 452 #ifdef __WIN32__
 453         case RESOURCE_WIN32_ENCRYPTED:
 454 #endif
 455                 /* Compare files by path: just a heuristic that will place files
 456                  * in the same directory next to each other.  */
 457                 return tstrcmp(lte1->file_on_disk, lte2->file_on_disk);
 458 #ifdef WITH_NTFS_3G
 459         case RESOURCE_IN_NTFS_VOLUME:
 460                 return tstrcmp(lte1->ntfs_loc->path, lte2->ntfs_loc->path);
 461 #endif
 462         default:
 463                 /* No additional sorting order defined for this resource
 464                  * location (e.g. RESOURCE_IN_ATTACHED_BUFFER); simply compare
 465                  * everything equal to each other.  */
 466                 return 0;
 467         }
 468 }
 469
 470 int
 471 sort_stream_list(struct list_head *stream_list,
 472                  size_t list_head_offset,
 473                  int (*compar)(const void *, const void*))
 474 {
 475         struct list_head *cur;
 476         struct wim_lookup_table_entry **array;
 477         size_t i;
 478         size_t array_size;
 479         size_t num_streams = 0;
 480
 481         list_for_each(cur, stream_list)
 482                 num_streams++;
 483
 484         if (num_streams <= 1)
 485                 return 0;
 486
 487         array_size = num_streams * sizeof(array[0]);
 488         array = MALLOC(array_size);
 489         if (array == NULL)
 490                 return WIMLIB_ERR_NOMEM;
 491
 492         cur = stream_list->next;
 493         for (i = 0; i < num_streams; i++) {
 494                 array[i] = (struct wim_lookup_table_entry*)((u8*)cur -
 495                                                             list_head_offset);
 496                 cur = cur->next;
 497         }
 498
 499         qsort(array, num_streams, sizeof(array[0]), compar);
 500
 501         INIT_LIST_HEAD(stream_list);
 502         for (i = 0; i < num_streams; i++) {
 503                 list_add_tail((struct list_head*)
 504                                ((u8*)array[i] + list_head_offset),
 505                               stream_list);
 506         }
 507         FREE(array);
 508         return 0;
 509 }
 510
 511 /* Sort the specified list of streams in an order optimized for reading.  */
 512 int
 513 sort_stream_list_by_sequential_order(struct list_head *stream_list,
 514                                      size_t list_head_offset)
 515 {
 516         return sort_stream_list(stream_list, list_head_offset,
 517                                 cmp_streams_by_sequential_order);
 518 }
 519
 520
 521 static int
 522 add_lte_to_array(struct wim_lookup_table_entry *lte,
 523                  void *_pp)
 524 {
 525         struct wim_lookup_table_entry ***pp = _pp;
 526         *(*pp)++ = lte;
 527         return 0;
 528 }
 529
 530 /* Iterate through the lookup table entries, but first sort them by stream
 531  * offset in the WIM.  Caution: this is intended to be used when the stream
 532  * offset field has actually been set. */
 533 int
 534 for_lookup_table_entry_pos_sorted(struct wim_lookup_table *table,
 535                                   int (*visitor)(struct wim_lookup_table_entry *,
 536                                                  void *),
 537                                   void *arg)
 538 {
 539         struct wim_lookup_table_entry **lte_array, **p;
 540         size_t num_streams = table->num_entries;
 541         int ret;
 542
 543         lte_array = MALLOC(num_streams * sizeof(lte_array[0]));
 544         if (!lte_array)
 545                 return WIMLIB_ERR_NOMEM;
 546         p = lte_array;
 547         for_lookup_table_entry(table, add_lte_to_array, &p);
 548
 549         wimlib_assert(p == lte_array + num_streams);
 550
 551         qsort(lte_array, num_streams, sizeof(lte_array[0]),
 552               cmp_streams_by_sequential_order);
 553         ret = 0;
 554         for (size_t i = 0; i < num_streams; i++) {
 555                 ret = visitor(lte_array[i], arg);
 556                 if (ret)
 557                         break;
 558         }
 559         FREE(lte_array);
 560         return ret;
 561 }
 562
 563 /* On-disk format of a WIM lookup table entry (stream entry). */
 564 struct wim_lookup_table_entry_disk {
 565         /* Size, offset, and flags of the stream.  */
 566         struct wim_reshdr_disk reshdr;
 567
 568         /* Which part of the split WIM this stream is in; indexed from 1. */
 569         le16 part_number;
 570
 571         /* Reference count of this stream over all WIM images. */
 572         le32 refcnt;
 573
 574         /* SHA1 message digest of the uncompressed data of this stream, or
 575          * optionally all zeroes if this stream is of zero length. */
 576         u8 hash[SHA1_HASH_SIZE];
 577 } _packed_attribute;
 578
 579 #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
 580
 581 static int
 582 cmp_streams_by_offset_in_res(const void *p1, const void *p2)
 583 {
 584         const struct wim_lookup_table_entry *lte1, *lte2;
 585
 586         lte1 = *(const struct wim_lookup_table_entry**)p1;
 587         lte2 = *(const struct wim_lookup_table_entry**)p2;
 588
 589         return cmp_u64(lte1->offset_in_res, lte2->offset_in_res);
 590 }
 591
 592 /* Validate the size and location of a WIM resource.  */
 593 static int
 594 validate_resource(struct wim_resource_spec *rspec)
 595 {
 596         struct wim_lookup_table_entry *lte;
 597         bool out_of_order;
 598         u64 expected_next_offset;
 599         int ret;
 600
 601         /* Verify that the resource itself has a valid offset and size.  */
 602         if (rspec->offset_in_wim + rspec->size_in_wim < rspec->size_in_wim)
 603                 goto invalid_due_to_overflow;
 604
 605         /* Verify that each stream in the resource has a valid offset and size.
 606          */
 607         expected_next_offset = 0;
 608         out_of_order = false;
 609         list_for_each_entry(lte, &rspec->stream_list, rspec_node) {
 610                 if (lte->offset_in_res + lte->size < lte->size ||
 611                     lte->offset_in_res + lte->size > rspec->uncompressed_size)
 612                         goto invalid_due_to_overflow;
 613
 614                 if (lte->offset_in_res >= expected_next_offset)
 615                         expected_next_offset = lte->offset_in_res + lte->size;
 616                 else
 617                         out_of_order = true;
 618         }
 619
 620         /* If the streams were not located at strictly increasing positions (not
 621          * allowing for overlap), sort them.  Then make sure that none overlap.
 622          */
 623         if (out_of_order) {
 624                 ret = sort_stream_list(&rspec->stream_list,
 625                                        offsetof(struct wim_lookup_table_entry,
 626                                                 rspec_node),
 627                                        cmp_streams_by_offset_in_res);
 628                 if (ret)
 629                         return ret;
 630
 631                 expected_next_offset = 0;
 632                 list_for_each_entry(lte, &rspec->stream_list, rspec_node) {
 633                         if (lte->offset_in_res >= expected_next_offset)
 634                                 expected_next_offset = lte->offset_in_res + lte->size;
 635                         else
 636                                 goto invalid_due_to_overlap;
 637                 }
 638         }
 639
 640         return 0;
 641
 642 invalid_due_to_overflow:
 643         ERROR("Invalid resource entry (offset overflow)");
 644         return WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 645
 646 invalid_due_to_overlap:
 647         ERROR("Invalid resource entry (streams in packed resource overlap)");
 648         return WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 649 }
 650
 651 /* Validate the resource, or free it if unused.  */
 652 static int
 653 finish_resource(struct wim_resource_spec *rspec)
 654 {
 655         if (!list_empty(&rspec->stream_list)) {
 656                 /* This resource contains at least one stream.  */
 657                 return validate_resource(rspec);
 658         } else {
 659                 /* No streams are in this resource.  Get rid of it.  */
 660                 FREE(rspec);
 661                 return 0;
 662         }
 663 }
 664
 665 /*
 666  * Reads the lookup table from a WIM file.  Usually, each entry specifies a
 667  * stream that the WIM file contains, along with its location and SHA1 message
 668  * digest.
 669  *
 670  * Saves lookup table entries for non-metadata streams in a hash table (set to
 671  * wim->lookup_table), and saves the metadata entry for each image in a special
 672  * per-image location (the wim->image_metadata array).
 673  *
 674  * This works for both version WIM_VERSION_DEFAULT (68864) and version
 675  * WIM_VERSION_PACKED_STREAMS (3584) WIMs.
 676  *
 677  * Possible return values:
 678  *      WIMLIB_ERR_SUCCESS (0)
 679  *      WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY
 680  *      WIMLIB_ERR_NOMEM
 681  *
 682  *      Or an error code caused by failure to read the lookup table from the WIM
 683  *      file.
 684  */
 685 int
 686 read_wim_lookup_table(WIMStruct *wim)
 687 {
 688         int ret;
 689         size_t num_entries;
 690         void *buf = NULL;
 691         struct wim_lookup_table *table = NULL;
 692         struct wim_lookup_table_entry *cur_entry = NULL;
 693         struct wim_resource_spec *cur_rspec = NULL;
 694         size_t num_duplicate_entries = 0;
 695         size_t num_wrong_part_entries = 0;
 696         u32 image_index = 0;
 697
 698         DEBUG("Reading lookup table.");
 699
 700         /* Sanity check: lookup table entries are 50 bytes each.  */
 701         BUILD_BUG_ON(sizeof(struct wim_lookup_table_entry_disk) !=
 702                      WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE);
 703
 704         /* Calculate the number of entries in the lookup table.  */
 705         num_entries = wim->hdr.lookup_table_reshdr.uncompressed_size /
 706                       sizeof(struct wim_lookup_table_entry_disk);
 707
 708         /* Read the lookup table into a buffer.  */
 709         ret = wim_reshdr_to_data(&wim->hdr.lookup_table_reshdr, wim, &buf);
 710         if (ret)
 711                 goto out;
 712
 713         /* Allocate a hash table to map SHA1 message digests into stream
 714          * specifications.  This is the in-memory "lookup table".  */
 715         table = new_lookup_table(num_entries * 2 + 1);
 716         if (!table)
 717                 goto oom;
 718
 719         /* Allocate and initalize stream entries ('struct
 720          * wim_lookup_table_entry's) from the raw lookup table buffer.  Each of
 721          * these entries will point to a 'struct wim_resource_spec' that
 722          * describes the underlying resource.  In WIMs with version number
 723          * WIM_VERSION_PACKED_STREAMS, a resource may contain multiple streams.
 724          */
 725         for (size_t i = 0; i < num_entries; i++) {
 726                 const struct wim_lookup_table_entry_disk *disk_entry =
 727                         &((const struct wim_lookup_table_entry_disk*)buf)[i];
 728                 struct wim_reshdr reshdr;
 729                 u16 part_number;
 730
 731                 /* Get the resource header  */
 732                 get_wim_reshdr(&disk_entry->reshdr, &reshdr);
 733
 734                 DEBUG("reshdr: size_in_wim=%"PRIu64", "
 735                       "uncompressed_size=%"PRIu64", "
 736                       "offset_in_wim=%"PRIu64", "
 737                       "flags=0x%02x\n",
 738                       reshdr.size_in_wim, reshdr.uncompressed_size,
 739                       reshdr.offset_in_wim, reshdr.flags);
 740
 741                 /* Ignore PACKED_STREAMS flag if it isn't supposed to be used in
 742                  * this WIM version  */
 743                 if (wim->hdr.wim_version == WIM_VERSION_DEFAULT)
 744                         reshdr.flags &= ~WIM_RESHDR_FLAG_PACKED_STREAMS;
 745
 746                 /* Allocate a 'struct wim_lookup_table_entry'  */
 747                 cur_entry = new_lookup_table_entry();
 748                 if (!cur_entry)
 749                         goto oom;
 750
 751                 /* Get the part number, reference count, and hash.  */
 752                 part_number = le16_to_cpu(disk_entry->part_number);
 753                 cur_entry->refcnt = le32_to_cpu(disk_entry->refcnt);
 754                 copy_hash(cur_entry->hash, disk_entry->hash);
 755
 756                 /* Verify that the part number matches that of the underlying
 757                  * WIM file.  */
 758                 if (part_number != wim->hdr.part_number) {
 759                         num_wrong_part_entries++;
 760                         goto free_cur_entry_and_continue;
 761                 }
 762
 763                 /* If resource is uncompressed, check for (unexpected) size
 764                  * mismatch.  */
 765                 if (!(reshdr.flags & (WIM_RESHDR_FLAG_PACKED_STREAMS |
 766                                       WIM_RESHDR_FLAG_COMPRESSED))) {
 767                         if (reshdr.uncompressed_size != reshdr.size_in_wim) {
 768                                 /* So ... This is an uncompressed resource, but
 769                                  * its uncompressed size is NOT the same as its
 770                                  * "compressed" size (size_in_wim).  What to do
 771                                  * with it?
 772                                  *
 773                                  * Based on a simple test, WIMGAPI seems to
 774                                  * handle this as follows:
 775                                  *
 776                                  * if (size_in_wim > uncompressed_size) {
 777                                  *      Ignore uncompressed_size; use
 778                                  *      size_in_wim instead.
 779                                  * } else {
 780                                  *      Honor uncompressed_size, but treat the
 781                                  *      part of the file data above size_in_wim
 782                                  *      as all zeros.
 783                                  * }
 784                                  *
 785                                  * So we will do the same.
 786                                  */
 787                                 if (reshdr.size_in_wim > reshdr.uncompressed_size)
 788                                         reshdr.uncompressed_size = reshdr.size_in_wim;
 789                         }
 790                 }
 791
 792                 /*
 793                  * Possibly start a new resource.
 794                  *
 795                  * We need to start a new resource if:
 796                  *
 797                  * - There is no previous resource (cur_rspec).
 798                  *
 799                  *   OR
 800                  *
 801                  * - The resource header did not have PACKED_STREAMS set, so it
 802                  *   specifies a new, single-stream resource.
 803                  *
 804                  *   OR
 805                  *
 806                  * - The resource header had PACKED_STREAMS set, and it's a
 807                  *   special entry that specifies the resource itself as opposed
 808                  *   to a stream, and we already encountered one such entry in
 809                  *   the current resource.  We will interpret this as the
 810                  *   beginning of a new packed resource.  (However, note that
 811                  *   wimlib does not currently allow create WIMs with multiple
 812                  *   packed resources, as to remain compatible with WIMGAPI.)
 813                  */
 814                 if (likely(!cur_rspec) ||
 815                     !(reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) ||
 816                       (reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER &&
 817                        cur_rspec->size_in_wim != 0))
 818                 {
 819                         /* Finish previous resource (if existent)  */
 820                         if (cur_rspec) {
 821                                 ret = finish_resource(cur_rspec);
 822                                 cur_rspec = NULL;
 823                                 if (ret)
 824                                         goto out;
 825                         }
 826
 827                         /* Allocate the resource specification and initialize it
 828                          * with values from the current stream entry.  */
 829                         cur_rspec = MALLOC(sizeof(*cur_rspec));
 830                         if (!cur_rspec)
 831                                 goto oom;
 832
 833                         wim_res_hdr_to_spec(&reshdr, wim, cur_rspec);
 834
 835                         /* If this is a packed run, the current stream entry may
 836                          * specify a stream within the resource, and not the
 837                          * resource itself.  Zero possibly irrelevant data until
 838                          * it is read for certain.  */
 839                         if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
 840                                 cur_rspec->size_in_wim = 0;
 841                                 cur_rspec->uncompressed_size = 0;
 842                                 cur_rspec->offset_in_wim = 0;
 843                         }
 844                 }
 845
 846                 /* Now cur_rspec != NULL.  */
 847
 848                 /* Checked for packed resource specification.  */
 849                 if (unlikely((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
 850                              reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER))
 851                 {
 852                         /* Found the specification for the packed resource.
 853                          * Transfer the values to the `struct
 854                          * wim_resource_spec', and discard the current stream
 855                          * since this lookup table entry did not, in fact,
 856                          * correspond to a "stream".  */
 857
 858                         /* The uncompressed size of the packed resource is
 859                          * actually stored in the header of the resource itself.
 860                          * Read it, and also grab the chunk size and compression
 861                          * type (which are not necessarily the defaults from the
 862                          * WIM header).  */
 863                         struct alt_chunk_table_header_disk hdr;
 864
 865                         ret = full_pread(&wim->in_fd, &hdr,
 866                                          sizeof(hdr), reshdr.offset_in_wim);
 867                         if (ret)
 868                                 goto out;
 869
 870                         cur_rspec->uncompressed_size = le64_to_cpu(hdr.res_usize);
 871                         cur_rspec->offset_in_wim = reshdr.offset_in_wim;
 872                         cur_rspec->size_in_wim = reshdr.size_in_wim;
 873                         cur_rspec->flags = reshdr.flags;
 874
 875                         /* Compression format numbers must be the same as in
 876                          * WIMGAPI to be compatible here.  */
 877                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_NONE != 0);
 878                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_XPRESS != 1);
 879                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZX != 2);
 880                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZMS != 3);
 881                         cur_rspec->compression_type = le32_to_cpu(hdr.compression_format);
 882
 883                         cur_rspec->chunk_size = le32_to_cpu(hdr.chunk_size);
 884
 885                         DEBUG("Full pack is %"PRIu64" compressed bytes "
 886                               "at file offset %"PRIu64" (flags 0x%02x)",
 887                               cur_rspec->size_in_wim,
 888                               cur_rspec->offset_in_wim,
 889                               cur_rspec->flags);
 890                         goto free_cur_entry_and_continue;
 891                 }
 892
 893                 /* Ignore entries with all zeroes in the hash field.  */
 894                 if (is_zero_hash(cur_entry->hash))
 895                         goto free_cur_entry_and_continue;
 896
 897                 if (reshdr.flags & WIM_RESHDR_FLAG_METADATA) {
 898
 899                         /* Lookup table entry for a metadata resource.  */
 900
 901                         /* Metadata entries with no references must be ignored.
 902                          * See, for example, the WinPE WIMs from the WAIK v2.1.
 903                          */
 904                         if (cur_entry->refcnt == 0)
 905                                 goto free_cur_entry_and_continue;
 906
 907                         if (cur_entry->refcnt != 1) {
 908                                 /* We don't currently support this case due to
 909                                  * the complications of multiple images sharing
 910                                  * the same metadata resource or a metadata
 911                                  * resource also being referenced by files.
 912                                  */
 913                                 ERROR("Found metadata resource with refcnt != 1");
 914                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 915                                 goto out;
 916                         }
 917
 918                         if (wim->hdr.part_number != 1) {
 919                                 WARNING("Ignoring metadata resource found in a "
 920                                         "non-first part of the split WIM");
 921                                 goto free_cur_entry_and_continue;
 922                         }
 923
 924                         /* The number of entries in the lookup table with
 925                          * WIM_RESHDR_FLAG_METADATA set should be the same as
 926                          * the image_count field in the WIM header.  */
 927                         if (image_index == wim->hdr.image_count) {
 928                                 WARNING("Found more metadata resources than images");
 929                                 goto free_cur_entry_and_continue;
 930                         }
 931
 932                         /* Notice very carefully:  We are assigning the metadata
 933                          * resources to images in the same order in which their
 934                          * lookup table entries occur on disk.  (This is also
 935                          * the behavior of Microsoft's software.)  In
 936                          * particular, this overrides the actual locations of
 937                          * the metadata resources themselves in the WIM file as
 938                          * well as any information written in the XML data.  */
 939                         DEBUG("Found metadata resource for image %"PRIu32" at "
 940                               "offset %"PRIu64".",
 941                               image_index + 1,
 942                               reshdr.offset_in_wim);
 943
 944                         wim->image_metadata[image_index++]->metadata_lte = cur_entry;
 945                 } else {
 946                         /* Lookup table entry for a non-metadata stream.  */
 947
 948                         /* Ignore this stream if it's a duplicate.  */
 949                         if (lookup_stream(table, cur_entry->hash)) {
 950                                 num_duplicate_entries++;
 951                                 goto free_cur_entry_and_continue;
 952                         }
 953
 954                         /* Insert the stream into the in-memory lookup table,
 955                          * keyed by its SHA1 message digest.  */
 956                         lookup_table_insert(table, cur_entry);
 957                 }
 958
 959                 /* Add the stream to the current resource specification.  */
 960                 lte_bind_wim_resource_spec(cur_entry, cur_rspec);
 961                 if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
 962                         /* In packed runs, the offset field is used for
 963                          * in-resource offset, not the in-WIM offset, and the
 964                          * size field is used for the uncompressed size, not the
 965                          * compressed size.  */
 966                         cur_entry->offset_in_res = reshdr.offset_in_wim;
 967                         cur_entry->size = reshdr.size_in_wim;
 968                         cur_entry->flags = reshdr.flags;
 969                         /* cur_rspec stays the same  */
 970
 971                 } else {
 972                         /* Normal case: The stream corresponds one-to-one with
 973                          * the resource entry.  */
 974                         cur_entry->offset_in_res = 0;
 975                         cur_entry->size = reshdr.uncompressed_size;
 976                         cur_entry->flags = reshdr.flags;
 977                         ret = validate_resource(cur_rspec);
 978                         cur_rspec = NULL;
 979                         if (ret)
 980                                 goto out;
 981                 }
 982                 continue;
 983
 984         free_cur_entry_and_continue:
 985                 free_lookup_table_entry(cur_entry);
 986         }
 987         cur_entry = NULL;
 988
 989         /* Validate the last resource.  */
 990         if (cur_rspec) {
 991                 ret = finish_resource(cur_rspec);
 992                 cur_rspec = NULL;
 993                 if (ret)
 994                         goto out;
 995         }
 996
 997         if (wim->hdr.part_number == 1 && image_index != wim->hdr.image_count) {
 998                 WARNING("Could not find metadata resources for all images");
 999                 for (u32 i = image_index; i < wim->hdr.image_count; i++)
1000                         put_image_metadata(wim->image_metadata[i], NULL);
1001                 wim->hdr.image_count = image_index;
1002         }
1003
1004         if (num_duplicate_entries > 0) {
1005                 WARNING("Ignoring %zu duplicate streams in the WIM lookup table",
1006                         num_duplicate_entries);
1007         }
1008
1009         if (num_wrong_part_entries > 0) {
1010                 WARNING("Ignoring %zu streams with wrong part number",
1011                         num_wrong_part_entries);
1012         }
1013
1014         DEBUG("Done reading lookup table.");
1015         wim->lookup_table = table;
1016         table = NULL;
1017         ret = 0;
1018         goto out;
1019 oom:
1020         ERROR("Not enough memory to read lookup table!");
1021         ret = WIMLIB_ERR_NOMEM;
1022 out:
1023         if (cur_rspec && list_empty(&cur_rspec->stream_list))
1024                 FREE(cur_rspec);
1025         free_lookup_table_entry(cur_entry);
1026         free_lookup_table(table);
1027         FREE(buf);
1028         return ret;
1029 }
1030
1031 static void
1032 put_wim_lookup_table_entry(struct wim_lookup_table_entry_disk *disk_entry,
1033                            const struct wim_reshdr *out_reshdr,
1034                            u16 part_number, u32 refcnt, const u8 *hash)
1035 {
1036         put_wim_reshdr(out_reshdr, &disk_entry->reshdr);
1037         disk_entry->part_number = cpu_to_le16(part_number);
1038         disk_entry->refcnt = cpu_to_le32(refcnt);
1039         copy_hash(disk_entry->hash, hash);
1040 }
1041
1042 int
1043 write_wim_lookup_table_from_stream_list(struct list_head *stream_list,
1044                                         struct filedes *out_fd,
1045                                         u16 part_number,
1046                                         struct wim_reshdr *out_reshdr,
1047                                         int write_resource_flags)
1048 {
1049         size_t table_size;
1050         struct wim_lookup_table_entry *lte;
1051         struct wim_lookup_table_entry_disk *table_buf;
1052         struct wim_lookup_table_entry_disk *table_buf_ptr;
1053         int ret;
1054         u64 prev_res_offset_in_wim = ~0ULL;
1055
1056         table_size = 0;
1057         list_for_each_entry(lte, stream_list, lookup_table_list) {
1058                 table_size += sizeof(struct wim_lookup_table_entry_disk);
1059
1060                 if (lte->out_reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS &&
1061                     lte->out_res_offset_in_wim != prev_res_offset_in_wim)
1062                 {
1063                         table_size += sizeof(struct wim_lookup_table_entry_disk);
1064                         prev_res_offset_in_wim = lte->out_res_offset_in_wim;
1065                 }
1066         }
1067
1068         DEBUG("Writing WIM lookup table (size=%zu, offset=%"PRIu64")",
1069               table_size, out_fd->offset);
1070
1071         table_buf = MALLOC(table_size);
1072         if (table_buf == NULL) {
1073                 ERROR("Failed to allocate %zu bytes for temporary lookup table",
1074                       table_size);
1075                 return WIMLIB_ERR_NOMEM;
1076         }
1077         table_buf_ptr = table_buf;
1078
1079         prev_res_offset_in_wim = ~0ULL;
1080         list_for_each_entry(lte, stream_list, lookup_table_list) {
1081
1082                 put_wim_lookup_table_entry(table_buf_ptr++,
1083                                            &lte->out_reshdr,
1084                                            part_number,
1085                                            lte->out_refcnt,
1086                                            lte->hash);
1087                 if (lte->out_reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS &&
1088                     lte->out_res_offset_in_wim != prev_res_offset_in_wim)
1089                 {
1090                         /* Put the main resource entry for the pack.  */
1091
1092                         struct wim_reshdr reshdr;
1093
1094                         reshdr.offset_in_wim = lte->out_res_offset_in_wim;
1095                         reshdr.size_in_wim = lte->out_res_size_in_wim;
1096                         reshdr.uncompressed_size = WIM_PACK_MAGIC_NUMBER;
1097                         reshdr.flags = WIM_RESHDR_FLAG_PACKED_STREAMS;
1098
1099                         DEBUG("Putting main entry for pack: "
1100                               "size_in_wim=%"PRIu64", "
1101                               "offset_in_wim=%"PRIu64", "
1102                               "uncompressed_size=%"PRIu64,
1103                               reshdr.size_in_wim,
1104                               reshdr.offset_in_wim,
1105                               reshdr.uncompressed_size);
1106
1107                         put_wim_lookup_table_entry(table_buf_ptr++,
1108                                                    &reshdr,
1109                                                    part_number,
1110                                                    1, zero_hash);
1111                         prev_res_offset_in_wim = lte->out_res_offset_in_wim;
1112                 }
1113
1114         }
1115         wimlib_assert((u8*)table_buf_ptr - (u8*)table_buf == table_size);
1116
1117         /* Write the lookup table uncompressed.  Although wimlib can handle a
1118          * compressed lookup table, MS software cannot.  */
1119         ret = write_wim_resource_from_buffer(table_buf,
1120                                              table_size,
1121                                              WIM_RESHDR_FLAG_METADATA,
1122                                              out_fd,
1123                                              WIMLIB_COMPRESSION_TYPE_NONE,
1124                                              0,
1125                                              out_reshdr,
1126                                              NULL,
1127                                              write_resource_flags);
1128         FREE(table_buf);
1129         DEBUG("ret=%d", ret);
1130         return ret;
1131 }
1132
1133 int
1134 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
1135 {
1136         lte->real_refcnt = 0;
1137         return 0;
1138 }
1139
1140 int
1141 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
1142 {
1143         lte->out_refcnt = 0;
1144         return 0;
1145 }
1146
1147 int
1148 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *_ignore)
1149 {
1150         if (lte->extracted_file != NULL) {
1151                 FREE(lte->extracted_file);
1152                 lte->extracted_file = NULL;
1153         }
1154         return 0;
1155 }
1156
1157 /* Allocate a stream entry for the contents of the buffer, or re-use an existing
1158  * entry in @lookup_table for the same stream.  */
1159 struct wim_lookup_table_entry *
1160 new_stream_from_data_buffer(const void *buffer, size_t size,
1161                             struct wim_lookup_table *lookup_table)
1162 {
1163         u8 hash[SHA1_HASH_SIZE];
1164         struct wim_lookup_table_entry *lte, *existing_lte;
1165
1166         sha1_buffer(buffer, size, hash);
1167         existing_lte = lookup_stream(lookup_table, hash);
1168         if (existing_lte) {
1169                 wimlib_assert(existing_lte->size == size);
1170                 lte = existing_lte;
1171                 lte->refcnt++;
1172         } else {
1173                 void *buffer_copy;
1174                 lte = new_lookup_table_entry();
1175                 if (lte == NULL)
1176                         return NULL;
1177                 buffer_copy = memdup(buffer, size);
1178                 if (buffer_copy == NULL) {
1179                         free_lookup_table_entry(lte);
1180                         return NULL;
1181                 }
1182                 lte->resource_location  = RESOURCE_IN_ATTACHED_BUFFER;
1183                 lte->attached_buffer    = buffer_copy;
1184                 lte->size               = size;
1185                 copy_hash(lte->hash, hash);
1186                 lookup_table_insert(lookup_table, lte);
1187         }
1188         return lte;
1189 }
1190
1191 /* Calculate the SHA1 message digest of a stream and move it from the list of
1192  * unhashed streams to the stream lookup table, possibly joining it with an
1193  * existing lookup table entry for an identical stream.
1194  *
1195  * @lte:  An unhashed lookup table entry.
1196  * @lookup_table:  Lookup table for the WIM.
1197  * @lte_ret:  On success, write a pointer to the resulting lookup table
1198  *            entry to this location.  This will be the same as @lte
1199  *            if it was inserted into the lookup table, or different if
1200  *            a duplicate stream was found.
1201  *
1202  * Returns 0 on success; nonzero if there is an error reading the stream.
1203  */
1204 int
1205 hash_unhashed_stream(struct wim_lookup_table_entry *lte,
1206                      struct wim_lookup_table *lookup_table,
1207                      struct wim_lookup_table_entry **lte_ret)
1208 {
1209         int ret;
1210         struct wim_lookup_table_entry *duplicate_lte;
1211         struct wim_lookup_table_entry **back_ptr;
1212
1213         wimlib_assert(lte->unhashed);
1214
1215         /* back_ptr must be saved because @back_inode and @back_stream_id are in
1216          * union with the SHA1 message digest and will no longer be valid once
1217          * the SHA1 has been calculated. */
1218         back_ptr = retrieve_lte_pointer(lte);
1219
1220         ret = sha1_stream(lte);
1221         if (ret)
1222                 return ret;
1223
1224         /* Look for a duplicate stream */
1225         duplicate_lte = lookup_stream(lookup_table, lte->hash);
1226         list_del(&lte->unhashed_list);
1227         if (duplicate_lte) {
1228                 /* We have a duplicate stream.  Transfer the reference counts
1229                  * from this stream to the duplicate and update the reference to
1230                  * this stream (in an inode or ads_entry) to point to the
1231                  * duplicate.  The caller is responsible for freeing @lte if
1232                  * needed.  */
1233                 wimlib_assert(!(duplicate_lte->unhashed));
1234                 wimlib_assert(duplicate_lte->size == lte->size);
1235                 duplicate_lte->refcnt += lte->refcnt;
1236                 lte->refcnt = 0;
1237                 *back_ptr = duplicate_lte;
1238                 lte = duplicate_lte;
1239         } else {
1240                 /* No duplicate stream, so we need to insert this stream into
1241                  * the lookup table and treat it as a hashed stream. */
1242                 lookup_table_insert(lookup_table, lte);
1243                 lte->unhashed = 0;
1244         }
1245         *lte_ret = lte;
1246         return 0;
1247 }
1248
1249 void
1250 lte_to_wimlib_resource_entry(const struct wim_lookup_table_entry *lte,
1251                              struct wimlib_resource_entry *wentry)
1252 {
1253         memset(wentry, 0, sizeof(*wentry));
1254
1255         wentry->uncompressed_size = lte->size;
1256         if (lte->resource_location == RESOURCE_IN_WIM) {
1257                 wentry->part_number = lte->rspec->wim->hdr.part_number;
1258                 if (lte->flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
1259                         wentry->compressed_size = 0;
1260                         wentry->offset = lte->offset_in_res;
1261                 } else {
1262                         wentry->compressed_size = lte->rspec->size_in_wim;
1263                         wentry->offset = lte->rspec->offset_in_wim;
1264                 }
1265                 wentry->raw_resource_offset_in_wim = lte->rspec->offset_in_wim;
1266                 /*wentry->raw_resource_uncompressed_size = lte->rspec->uncompressed_size;*/
1267                 wentry->raw_resource_compressed_size = lte->rspec->size_in_wim;
1268         }
1269         copy_hash(wentry->sha1_hash, lte->hash);
1270         wentry->reference_count = lte->refcnt;
1271         wentry->is_compressed = (lte->flags & WIM_RESHDR_FLAG_COMPRESSED) != 0;
1272         wentry->is_metadata = (lte->flags & WIM_RESHDR_FLAG_METADATA) != 0;
1273         wentry->is_free = (lte->flags & WIM_RESHDR_FLAG_FREE) != 0;
1274         wentry->is_spanned = (lte->flags & WIM_RESHDR_FLAG_SPANNED) != 0;
1275         wentry->packed = (lte->flags & WIM_RESHDR_FLAG_PACKED_STREAMS) != 0;
1276 }
1277
1278 struct iterate_lte_context {
1279         wimlib_iterate_lookup_table_callback_t cb;
1280         void *user_ctx;
1281 };
1282
1283 static int
1284 do_iterate_lte(struct wim_lookup_table_entry *lte, void *_ctx)
1285 {
1286         struct iterate_lte_context *ctx = _ctx;
1287         struct wimlib_resource_entry entry;
1288
1289         lte_to_wimlib_resource_entry(lte, &entry);
1290         return (*ctx->cb)(&entry, ctx->user_ctx);
1291 }
1292
1293 /* API function documented in wimlib.h  */
1294 WIMLIBAPI int
1295 wimlib_iterate_lookup_table(WIMStruct *wim, int flags,
1296                             wimlib_iterate_lookup_table_callback_t cb,
1297                             void *user_ctx)
1298 {
1299         if (flags != 0)
1300                 return WIMLIB_ERR_INVALID_PARAM;
1301
1302         struct iterate_lte_context ctx = {
1303                 .cb = cb,
1304                 .user_ctx = user_ctx,
1305         };
1306         if (wim->hdr.part_number == 1) {
1307                 int ret;
1308                 for (int i = 0; i < wim->hdr.image_count; i++) {
1309                         ret = do_iterate_lte(wim->image_metadata[i]->metadata_lte,
1310                                              &ctx);
1311                         if (ret)
1312                                 return ret;
1313                 }
1314         }
1315         return for_lookup_table_entry(wim->lookup_table, do_iterate_lte, &ctx);
1316 }