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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 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 194 {
 195         if (lte) {
 196                 switch (lte->resource_location) {
 197                 case RESOURCE_IN_WIM:
 198                         list_del(&lte->rspec_node);
 199                         if (list_empty(&lte->rspec->stream_list))
 200                                 FREE(lte->rspec);
 201                         break;
 202                 case RESOURCE_IN_FILE_ON_DISK:
 203         #ifdef __WIN32__
 204                 case RESOURCE_WIN32_ENCRYPTED:
 205         #endif
 206         #ifdef WITH_FUSE
 207                 case RESOURCE_IN_STAGING_FILE:
 208                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 209                                      (void*)&lte->staging_file_name);
 210         #endif
 211                 case RESOURCE_IN_ATTACHED_BUFFER:
 212                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 213                                      (void*)&lte->attached_buffer);
 214                         FREE(lte->file_on_disk);
 215                         break;
 216 #ifdef WITH_NTFS_3G
 217                 case RESOURCE_IN_NTFS_VOLUME:
 218                         if (lte->ntfs_loc) {
 219                                 FREE(lte->ntfs_loc->path);
 220                                 FREE(lte->ntfs_loc->stream_name);
 221                                 FREE(lte->ntfs_loc);
 222                         }
 223                         break;
 224 #endif
 225                 default:
 226                         break;
 227                 }
 228                 FREE(lte);
 229         }
 230 }
 231
 232 /* Decrements the reference count for the lookup table entry @lte.  If its
 233  * reference count reaches 0, it is unlinked from the lookup table.  If,
 234  * furthermore, the entry has no opened file descriptors associated with it, the
 235  * entry is freed.  */
 236 void
 237 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 238                      struct wim_lookup_table *table)
 239 {
 240         wimlib_assert(lte->refcnt != 0);
 241
 242         if (--lte->refcnt == 0) {
 243                 if (lte->unhashed) {
 244                         list_del(&lte->unhashed_list);
 245                 #ifdef WITH_FUSE
 246                         /* If the stream has been extracted to a staging file
 247                          * for a FUSE mount, unlink the staging file.  (Note
 248                          * that there still may be open file descriptors to it.)
 249                          * */
 250                         if (lte->resource_location == RESOURCE_IN_STAGING_FILE)
 251                                 unlink(lte->staging_file_name);
 252                 #endif
 253                 } else {
 254                         lookup_table_unlink(table, lte);
 255                 }
 256
 257                 /* If FUSE mounts are enabled, we don't actually free the entry
 258                  * until the last file descriptor has been closed by
 259                  * lte_decrement_num_opened_fds().  */
 260 #ifdef WITH_FUSE
 261                 if (lte->num_opened_fds == 0)
 262 #endif
 263                         free_lookup_table_entry(lte);
 264         }
 265 }
 266
 267 #ifdef WITH_FUSE
 268 void
 269 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 270 {
 271         wimlib_assert(lte->num_opened_fds != 0);
 272
 273         if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 274                 free_lookup_table_entry(lte);
 275 }
 276 #endif
 277
 278 static void
 279 lookup_table_insert_raw(struct wim_lookup_table *table,
 280                         struct wim_lookup_table_entry *lte)
 281 {
 282         size_t i = lte->hash_short % table->capacity;
 283
 284         hlist_add_head(&lte->hash_list, &table->array[i]);
 285 }
 286
 287 static void
 288 enlarge_lookup_table(struct wim_lookup_table *table)
 289 {
 290         size_t old_capacity, new_capacity;
 291         struct hlist_head *old_array, *new_array;
 292         struct wim_lookup_table_entry *lte;
 293         struct hlist_node *cur, *tmp;
 294         size_t i;
 295
 296         old_capacity = table->capacity;
 297         new_capacity = old_capacity * 2;
 298         new_array = CALLOC(new_capacity, sizeof(struct hlist_head));
 299         if (new_array == NULL)
 300                 return;
 301         old_array = table->array;
 302         table->array = new_array;
 303         table->capacity = new_capacity;
 304
 305         for (i = 0; i < old_capacity; i++) {
 306                 hlist_for_each_entry_safe(lte, cur, tmp, &old_array[i], hash_list) {
 307                         hlist_del(&lte->hash_list);
 308                         lookup_table_insert_raw(table, lte);
 309                 }
 310         }
 311         FREE(old_array);
 312 }
 313
 314 /* Inserts an entry into the lookup table.  */
 315 void
 316 lookup_table_insert(struct wim_lookup_table *table,
 317                     struct wim_lookup_table_entry *lte)
 318 {
 319         lookup_table_insert_raw(table, lte);
 320         if (++table->num_entries > table->capacity)
 321                 enlarge_lookup_table(table);
 322 }
 323
 324 /* Unlinks a lookup table entry from the table; does not free it.  */
 325 void
 326 lookup_table_unlink(struct wim_lookup_table *table,
 327                     struct wim_lookup_table_entry *lte)
 328 {
 329         wimlib_assert(!lte->unhashed);
 330         wimlib_assert(table->num_entries != 0);
 331
 332         hlist_del(&lte->hash_list);
 333         table->num_entries--;
 334 }
 335
 336 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 337  * lookup table, or NULL if there is none.  */
 338 struct wim_lookup_table_entry *
 339 lookup_stream(const struct wim_lookup_table *table, const u8 hash[])
 340 {
 341         size_t i;
 342         struct wim_lookup_table_entry *lte;
 343         struct hlist_node *pos;
 344
 345         i = *(size_t*)hash % table->capacity;
 346         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 347                 if (hashes_equal(hash, lte->hash))
 348                         return lte;
 349         return NULL;
 350 }
 351
 352 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 353  * return nonzero if any call to the function returns nonzero. */
 354 int
 355 for_lookup_table_entry(struct wim_lookup_table *table,
 356                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 357                        void *arg)
 358 {
 359         struct wim_lookup_table_entry *lte;
 360         struct hlist_node *pos, *tmp;
 361         int ret;
 362
 363         for (size_t i = 0; i < table->capacity; i++) {
 364                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 365                                           hash_list)
 366                 {
 367                         ret = visitor(lte, arg);
 368                         if (ret)
 369                                 return ret;
 370                 }
 371         }
 372         return 0;
 373 }
 374
 375 /* qsort() callback that sorts streams (represented by `struct
 376  * wim_lookup_table_entry's) into an order optimized for reading.
 377  *
 378  * Sorting is done primarily by resource location, then secondarily by a
 379  * per-resource location order.  For example, resources in WIM files are sorted
 380  * primarily by part number, then secondarily by offset, as to implement optimal
 381  * reading of either a standalone or split WIM.  */
 382 static int
 383 cmp_streams_by_sequential_order(const void *p1, const void *p2)
 384 {
 385         const struct wim_lookup_table_entry *lte1, *lte2;
 386         int v;
 387         WIMStruct *wim1, *wim2;
 388
 389         lte1 = *(const struct wim_lookup_table_entry**)p1;
 390         lte2 = *(const struct wim_lookup_table_entry**)p2;
 391
 392         v = (int)lte1->resource_location - (int)lte2->resource_location;
 393
 394         /* Different resource locations?  */
 395         if (v)
 396                 return v;
 397
 398         switch (lte1->resource_location) {
 399         case RESOURCE_IN_WIM:
 400                 wim1 = lte1->rspec->wim;
 401                 wim2 = lte2->rspec->wim;
 402
 403                 /* Different (possibly split) WIMs?  */
 404                 if (wim1 != wim2) {
 405                         v = memcmp(wim1->hdr.guid, wim2->hdr.guid, WIM_GID_LEN);
 406                         if (v)
 407                                 return v;
 408                 }
 409
 410                 /* Different part numbers in the same WIM?  */
 411                 v = (int)wim1->hdr.part_number - (int)wim2->hdr.part_number;
 412                 if (v)
 413                         return v;
 414
 415                 if (lte1->rspec->offset_in_wim != lte2->rspec->offset_in_wim)
 416                         return cmp_u64(lte1->rspec->offset_in_wim,
 417                                        lte2->rspec->offset_in_wim);
 418
 419                 return cmp_u64(lte1->offset_in_res, lte2->offset_in_res);
 420
 421         case RESOURCE_IN_FILE_ON_DISK:
 422 #ifdef WITH_FUSE
 423         case RESOURCE_IN_STAGING_FILE:
 424 #endif
 425 #ifdef __WIN32__
 426         case RESOURCE_WIN32_ENCRYPTED:
 427 #endif
 428                 /* Compare files by path: just a heuristic that will place files
 429                  * in the same directory next to each other.  */
 430                 return tstrcmp(lte1->file_on_disk, lte2->file_on_disk);
 431 #ifdef WITH_NTFS_3G
 432         case RESOURCE_IN_NTFS_VOLUME:
 433                 return tstrcmp(lte1->ntfs_loc->path, lte2->ntfs_loc->path);
 434 #endif
 435         default:
 436                 /* No additional sorting order defined for this resource
 437                  * location (e.g. RESOURCE_IN_ATTACHED_BUFFER); simply compare
 438                  * everything equal to each other.  */
 439                 return 0;
 440         }
 441 }
 442
 443 int
 444 sort_stream_list(struct list_head *stream_list,
 445                  size_t list_head_offset,
 446                  int (*compar)(const void *, const void*))
 447 {
 448         struct list_head *cur;
 449         struct wim_lookup_table_entry **array;
 450         size_t i;
 451         size_t array_size;
 452         size_t num_streams = 0;
 453
 454         list_for_each(cur, stream_list)
 455                 num_streams++;
 456
 457         if (num_streams <= 1)
 458                 return 0;
 459
 460         array_size = num_streams * sizeof(array[0]);
 461         array = MALLOC(array_size);
 462         if (array == NULL)
 463                 return WIMLIB_ERR_NOMEM;
 464
 465         cur = stream_list->next;
 466         for (i = 0; i < num_streams; i++) {
 467                 array[i] = (struct wim_lookup_table_entry*)((u8*)cur -
 468                                                             list_head_offset);
 469                 cur = cur->next;
 470         }
 471
 472         qsort(array, num_streams, sizeof(array[0]), compar);
 473
 474         INIT_LIST_HEAD(stream_list);
 475         for (i = 0; i < num_streams; i++) {
 476                 list_add_tail((struct list_head*)
 477                                ((u8*)array[i] + list_head_offset),
 478                               stream_list);
 479         }
 480         FREE(array);
 481         return 0;
 482 }
 483
 484 /* Sort the specified list of streams in an order optimized for reading.  */
 485 int
 486 sort_stream_list_by_sequential_order(struct list_head *stream_list,
 487                                      size_t list_head_offset)
 488 {
 489         return sort_stream_list(stream_list, list_head_offset,
 490                                 cmp_streams_by_sequential_order);
 491 }
 492
 493
 494 static int
 495 add_lte_to_array(struct wim_lookup_table_entry *lte,
 496                  void *_pp)
 497 {
 498         struct wim_lookup_table_entry ***pp = _pp;
 499         *(*pp)++ = lte;
 500         return 0;
 501 }
 502
 503 /* Iterate through the lookup table entries, but first sort them by stream
 504  * offset in the WIM.  Caution: this is intended to be used when the stream
 505  * offset field has actually been set. */
 506 int
 507 for_lookup_table_entry_pos_sorted(struct wim_lookup_table *table,
 508                                   int (*visitor)(struct wim_lookup_table_entry *,
 509                                                  void *),
 510                                   void *arg)
 511 {
 512         struct wim_lookup_table_entry **lte_array, **p;
 513         size_t num_streams = table->num_entries;
 514         int ret;
 515
 516         lte_array = MALLOC(num_streams * sizeof(lte_array[0]));
 517         if (!lte_array)
 518                 return WIMLIB_ERR_NOMEM;
 519         p = lte_array;
 520         for_lookup_table_entry(table, add_lte_to_array, &p);
 521
 522         wimlib_assert(p == lte_array + num_streams);
 523
 524         qsort(lte_array, num_streams, sizeof(lte_array[0]),
 525               cmp_streams_by_sequential_order);
 526         ret = 0;
 527         for (size_t i = 0; i < num_streams; i++) {
 528                 ret = visitor(lte_array[i], arg);
 529                 if (ret)
 530                         break;
 531         }
 532         FREE(lte_array);
 533         return ret;
 534 }
 535
 536 /* On-disk format of a WIM lookup table entry (stream entry). */
 537 struct wim_lookup_table_entry_disk {
 538         /* Size, offset, and flags of the stream.  */
 539         struct wim_reshdr_disk reshdr;
 540
 541         /* Which part of the split WIM this stream is in; indexed from 1. */
 542         le16 part_number;
 543
 544         /* Reference count of this stream over all WIM images. */
 545         le32 refcnt;
 546
 547         /* SHA1 message digest of the uncompressed data of this stream, or
 548          * optionally all zeroes if this stream is of zero length. */
 549         u8 hash[SHA1_HASH_SIZE];
 550 } _packed_attribute;
 551
 552 #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
 553
 554 /* Validate the size and location of a WIM resource.  */
 555 static int
 556 validate_resource(const struct wim_resource_spec *rspec)
 557 {
 558         struct wim_lookup_table_entry *lte;
 559         u64 cur_offset;
 560
 561         /* Verify that calculating the offset of the end of the resource doesn't
 562          * overflow.  */
 563         if (rspec->offset_in_wim + rspec->size_in_wim < rspec->size_in_wim)
 564                 goto invalid;
 565
 566         /* Verify that each stream in the resource has a valid offset and size,
 567          * and that no streams overlap, and that the streams were added in order
 568          * of increasing offset.  */
 569         cur_offset = 0;
 570         list_for_each_entry(lte, &rspec->stream_list, rspec_node) {
 571                 if (lte->offset_in_res + lte->size < lte->size ||
 572                     lte->offset_in_res + lte->size > rspec->uncompressed_size ||
 573                     lte->offset_in_res < cur_offset)
 574                         goto invalid;
 575
 576                 cur_offset = lte->offset_in_res + lte->size;
 577         }
 578         return 0;
 579
 580 invalid:
 581
 582         ERROR("Invalid resource entry!");
 583         return WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 584 }
 585
 586 /*
 587  * Reads the lookup table from a WIM file.  Each entry specifies a stream that
 588  * the WIM file contains, along with its location and SHA1 message digest.
 589  *
 590  * Saves lookup table entries for non-metadata streams in a hash table, and
 591  * saves the metadata entry for each image in a special per-image location (the
 592  * image_metadata array).
 593  *
 594  * Return values:
 595  *      WIMLIB_ERR_SUCCESS (0)
 596  *      WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY
 597  *      WIMLIB_ERR_RESOURCE_NOT_FOUND
 598  *
 599  *      Or an error code caused by failure to read the lookup table into memory.
 600  */
 601 int
 602 read_wim_lookup_table(WIMStruct *wim)
 603 {
 604         int ret;
 605         size_t i;
 606         size_t num_entries;
 607         struct wim_lookup_table *table;
 608         struct wim_lookup_table_entry *cur_entry, *duplicate_entry;
 609         struct wim_resource_spec *cur_rspec;
 610         void *buf;
 611         bool back_to_back_pack;
 612
 613         DEBUG("Reading lookup table.");
 614
 615         /* Sanity check: lookup table entries are 50 bytes each.  */
 616         BUILD_BUG_ON(sizeof(struct wim_lookup_table_entry_disk) !=
 617                      WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE);
 618
 619         /* Calculate number of entries in the lookup table.  */
 620         num_entries = wim->hdr.lookup_table_reshdr.uncompressed_size /
 621                       sizeof(struct wim_lookup_table_entry_disk);
 622
 623         /* Read the lookup table into a buffer.  */
 624         ret = wim_reshdr_to_data(&wim->hdr.lookup_table_reshdr, wim, &buf);
 625         if (ret)
 626                 goto out;
 627
 628         /* Allocate a hash table to map SHA1 message digests into stream
 629          * specifications.  This is the in-memory "lookup table".  */
 630         table = new_lookup_table(num_entries * 2 + 1);
 631         if (table == NULL) {
 632                 ERROR("Not enough memory to read lookup table.");
 633                 ret = WIMLIB_ERR_NOMEM;
 634                 goto out_free_buf;
 635         }
 636
 637         /* Allocate and initalize stream entries from the raw lookup table
 638          * buffer.  */
 639         wim->current_image = 0;
 640         cur_rspec = NULL;
 641         for (i = 0; i < num_entries; i++) {
 642                 const struct wim_lookup_table_entry_disk *disk_entry =
 643                         &((const struct wim_lookup_table_entry_disk*)buf)[i];
 644                 u16 part_number;
 645                 struct wim_reshdr reshdr;
 646
 647                 get_wim_reshdr(&disk_entry->reshdr, &reshdr);
 648
 649                 DEBUG("reshdr: size_in_wim=%"PRIu64", "
 650                       "uncompressed_size=%"PRIu64", "
 651                       "offset_in_wim=%"PRIu64", "
 652                       "flags=0x%02x",
 653                       reshdr.size_in_wim, reshdr.uncompressed_size,
 654                       reshdr.offset_in_wim, reshdr.flags);
 655
 656                 if (wim->hdr.wim_version == WIM_VERSION_DEFAULT)
 657                         reshdr.flags &= ~WIM_RESHDR_FLAG_PACKED_STREAMS;
 658
 659                 cur_entry = new_lookup_table_entry();
 660                 if (cur_entry == NULL) {
 661                         ERROR("Not enough memory to read lookup table!");
 662                         ret = WIMLIB_ERR_NOMEM;
 663                         goto err;
 664                 }
 665
 666                 part_number = le16_to_cpu(disk_entry->part_number);
 667                 cur_entry->refcnt = le32_to_cpu(disk_entry->refcnt);
 668                 copy_hash(cur_entry->hash, disk_entry->hash);
 669
 670                 if (part_number != wim->hdr.part_number) {
 671                         WARNING("A lookup table entry in part %hu of the WIM "
 672                                 "points to part %hu (ignoring it)",
 673                                 wim->hdr.part_number, part_number);
 674                         free_lookup_table_entry(cur_entry);
 675                         continue;
 676                 }
 677
 678                 if (!(reshdr.flags & (WIM_RESHDR_FLAG_PACKED_STREAMS |
 679                                       WIM_RESHDR_FLAG_COMPRESSED))) {
 680                         if (reshdr.uncompressed_size != reshdr.size_in_wim) {
 681                                 ERROR("Invalid resource entry!");
 682                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 683                                 goto err;
 684                         }
 685                 }
 686
 687                 back_to_back_pack = false;
 688                 if (!(reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) ||
 689                     cur_rspec == NULL ||
 690                     (back_to_back_pack =
 691                      ((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
 692                       reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER &&
 693                       cur_rspec != NULL &&
 694                       cur_rspec->size_in_wim != 0)))
 695                 {
 696                         /* Starting new run of streams that share the same WIM
 697                          * resource.  */
 698                         struct wim_lookup_table_entry *prev_entry = NULL;
 699
 700                         if (back_to_back_pack &&
 701                             !list_empty(&cur_rspec->stream_list))
 702                         {
 703                                 prev_entry = list_entry(cur_rspec->stream_list.prev,
 704                                                         struct wim_lookup_table_entry,
 705                                                         rspec_node);
 706                                 lte_unbind_wim_resource_spec(prev_entry);
 707                         }
 708                         if (cur_rspec != NULL) {
 709                                 ret = validate_resource(cur_rspec);
 710                                 if (ret)
 711                                         goto err;
 712                         }
 713
 714                         /* Allocate the resource specification and initialize it
 715                          * with values from the current stream entry.  */
 716                         cur_rspec = MALLOC(sizeof(*cur_rspec));
 717                         if (cur_rspec == NULL) {
 718                                 ERROR("Not enough memory to read lookup table!");
 719                                 ret = WIMLIB_ERR_NOMEM;
 720                                 goto err;
 721                         }
 722                         wim_res_hdr_to_spec(&reshdr, wim, cur_rspec);
 723
 724                         /* If this is a packed run, the current stream entry may
 725                          * specify a stream within the resource, and not the
 726                          * resource itself.  Zero possibly irrelevant data until
 727                          * it is read for certain.  (Note that the computation
 728                          * of 'back_to_back_pack' tests if 'size_in_wim' is
 729                          * nonzero to see if the resource info has been read;
 730                          * hence we need to set it to 0 here.)  */
 731                         if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
 732                                 cur_rspec->size_in_wim = 0;
 733                                 cur_rspec->uncompressed_size = 0;
 734                                 cur_rspec->offset_in_wim = 0;
 735                         }
 736
 737                         if (prev_entry)
 738                                 lte_bind_wim_resource_spec(prev_entry, cur_rspec);
 739                 }
 740
 741                 if ((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
 742                     reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER)
 743                 {
 744                         /* Found the specification for the packed resource.
 745                          * Transfer the values to the `struct
 746                          * wim_resource_spec', and discard the current stream
 747                          * since this lookup table entry did not, in fact,
 748                          * correspond to a "stream".
 749                          */
 750
 751                         /* Uncompressed size of the resource pack is actually
 752                          * stored in the header of the resource itself.  Read
 753                          * it, and also grab the chunk size and compression type
 754                          * (which are not necessarily the defaults from the WIM
 755                          * header).  */
 756                         struct alt_chunk_table_header_disk hdr;
 757
 758                         ret = full_pread(&wim->in_fd, &hdr,
 759                                          sizeof(hdr), reshdr.offset_in_wim);
 760                         if (ret)
 761                                 goto err;
 762
 763                         cur_rspec->uncompressed_size = le64_to_cpu(hdr.res_usize);
 764                         cur_rspec->offset_in_wim = reshdr.offset_in_wim;
 765                         cur_rspec->size_in_wim = reshdr.size_in_wim;
 766                         cur_rspec->flags = reshdr.flags;
 767
 768                         /* Compression format numbers must be the same as in
 769                          * WIMGAPI to be compatible here.  */
 770                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_NONE != 0);
 771                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZX != 1);
 772                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_XPRESS != 2);
 773                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZMS != 3);
 774                         cur_rspec->compression_type = le32_to_cpu(hdr.compression_format);
 775
 776                         cur_rspec->chunk_size = le32_to_cpu(hdr.chunk_size);
 777
 778                         DEBUG("Full pack is %"PRIu64" compressed bytes "
 779                               "at file offset %"PRIu64" (flags 0x%02x)",
 780                               cur_rspec->size_in_wim,
 781                               cur_rspec->offset_in_wim,
 782                               cur_rspec->flags);
 783                         free_lookup_table_entry(cur_entry);
 784                         continue;
 785                 }
 786
 787                 if (is_zero_hash(cur_entry->hash)) {
 788                         free_lookup_table_entry(cur_entry);
 789                         continue;
 790                 }
 791
 792                 if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
 793                         /* Continuing the pack with another stream.  */
 794                         DEBUG("Continuing pack with stream: "
 795                               "%"PRIu64" uncompressed bytes @ "
 796                               "resource offset %"PRIu64")",
 797                               reshdr.size_in_wim, reshdr.offset_in_wim);
 798                 }
 799
 800                 lte_bind_wim_resource_spec(cur_entry, cur_rspec);
 801                 if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
 802                         /* In packed runs, the offset field is used for
 803                          * in-resource offset, not the in-WIM offset, and the
 804                          * size field is used for the uncompressed size, not the
 805                          * compressed size.  */
 806                         cur_entry->offset_in_res = reshdr.offset_in_wim;
 807                         cur_entry->size = reshdr.size_in_wim;
 808                         cur_entry->flags = reshdr.flags;
 809                 } else {
 810                         /* Normal case: The stream corresponds one-to-one with
 811                          * the resource entry.  */
 812                         cur_entry->offset_in_res = 0;
 813                         cur_entry->size = reshdr.uncompressed_size;
 814                         cur_entry->flags = reshdr.flags;
 815                         cur_rspec = NULL;
 816                 }
 817
 818                 if (cur_entry->flags & WIM_RESHDR_FLAG_METADATA) {
 819                         /* Lookup table entry for a metadata resource */
 820
 821                         /* Metadata entries with no references must be ignored;
 822                          * see for example the WinPE WIMs from the WAIK v2.1.
 823                          * */
 824                         if (cur_entry->refcnt == 0) {
 825                                 free_lookup_table_entry(cur_entry);
 826                                 continue;
 827                         }
 828
 829                         if (cur_entry->refcnt != 1) {
 830                                 ERROR("Found metadata resource with refcnt != 1");
 831                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 832                                 goto err;
 833                         }
 834
 835                         if (wim->hdr.part_number != 1) {
 836                                 WARNING("Ignoring metadata resource found in a "
 837                                         "non-first part of the split WIM");
 838                                 free_lookup_table_entry(cur_entry);
 839                                 continue;
 840                         }
 841                         if (wim->current_image == wim->hdr.image_count) {
 842                                 WARNING("The WIM header says there are %u images "
 843                                         "in the WIM, but we found more metadata "
 844                                         "resources than this (ignoring the extra)",
 845                                         wim->hdr.image_count);
 846                                 free_lookup_table_entry(cur_entry);
 847                                 continue;
 848                         }
 849
 850                         /* Notice very carefully:  We are assigning the metadata
 851                          * resources in the exact order mirrored by their lookup
 852                          * table entries on disk, which is the behavior of
 853                          * Microsoft's software.  In particular, this overrides
 854                          * the actual locations of the metadata resources
 855                          * themselves in the WIM file as well as any information
 856                          * written in the XML data. */
 857                         DEBUG("Found metadata resource for image %u at "
 858                               "offset %"PRIu64".",
 859                               wim->current_image + 1,
 860                               cur_entry->rspec->offset_in_wim);
 861                         wim->image_metadata[
 862                                 wim->current_image++]->metadata_lte = cur_entry;
 863                         continue;
 864                 }
 865
 866                 /* Lookup table entry for a stream that is not a metadata
 867                  * resource.  */
 868                 duplicate_entry = lookup_stream(table, cur_entry->hash);
 869                 if (duplicate_entry) {
 870                         WARNING("The WIM lookup table contains two entries "
 871                                 "with the same SHA1 message digest!");
 872                         free_lookup_table_entry(cur_entry);
 873                         continue;
 874                 }
 875
 876                 /* Finally, insert the stream into the lookup table, keyed by
 877                  * its SHA1 message digest.  */
 878                 lookup_table_insert(table, cur_entry);
 879         }
 880         cur_entry = NULL;
 881
 882         /* Validate the last resource.  */
 883         if (cur_rspec != NULL) {
 884                 ret = validate_resource(cur_rspec);
 885                 if (ret)
 886                         goto err;
 887         }
 888
 889         if (wim->hdr.part_number == 1 && wim->current_image != wim->hdr.image_count) {
 890                 WARNING("The header of \"%"TS"\" says there are %u images in\n"
 891                         "          the WIM, but we only found %d metadata resources!  Acting as if\n"
 892                         "          the header specified only %d images instead.",
 893                         wim->filename, wim->hdr.image_count,
 894                         wim->current_image, wim->current_image);
 895                 for (int i = wim->current_image; i < wim->hdr.image_count; i++)
 896                         put_image_metadata(wim->image_metadata[i], NULL);
 897                 wim->hdr.image_count = wim->current_image;
 898         }
 899         DEBUG("Done reading lookup table.");
 900         wim->lookup_table = table;
 901         ret = 0;
 902         goto out_free_buf;
 903
 904 err:
 905         if (cur_rspec && list_empty(&cur_rspec->stream_list))
 906                 FREE(cur_rspec);
 907         free_lookup_table_entry(cur_entry);
 908         free_lookup_table(table);
 909 out_free_buf:
 910         FREE(buf);
 911 out:
 912         wim->current_image = 0;
 913         return ret;
 914 }
 915
 916 static void
 917 put_wim_lookup_table_entry(struct wim_lookup_table_entry_disk *disk_entry,
 918                            const struct wim_reshdr *out_reshdr,
 919                            u16 part_number, u32 refcnt, const u8 *hash)
 920 {
 921         put_wim_reshdr(out_reshdr, &disk_entry->reshdr);
 922         disk_entry->part_number = cpu_to_le16(part_number);
 923         disk_entry->refcnt = cpu_to_le32(refcnt);
 924         copy_hash(disk_entry->hash, hash);
 925 }
 926
 927 int
 928 write_wim_lookup_table_from_stream_list(struct list_head *stream_list,
 929                                         struct filedes *out_fd,
 930                                         u16 part_number,
 931                                         struct wim_reshdr *out_reshdr,
 932                                         int write_resource_flags)
 933 {
 934         size_t table_size;
 935         struct wim_lookup_table_entry *lte;
 936         struct wim_lookup_table_entry_disk *table_buf;
 937         struct wim_lookup_table_entry_disk *table_buf_ptr;
 938         int ret;
 939         u64 prev_res_offset_in_wim = ~0ULL;
 940
 941         table_size = 0;
 942         list_for_each_entry(lte, stream_list, lookup_table_list) {
 943                 table_size += sizeof(struct wim_lookup_table_entry_disk);
 944
 945                 if (lte->out_reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS &&
 946                     lte->out_res_offset_in_wim != prev_res_offset_in_wim)
 947                 {
 948                         table_size += sizeof(struct wim_lookup_table_entry_disk);
 949                         prev_res_offset_in_wim = lte->out_res_offset_in_wim;
 950                 }
 951         }
 952
 953         DEBUG("Writing WIM lookup table (size=%zu, offset=%"PRIu64")",
 954               table_size, out_fd->offset);
 955
 956         table_buf = MALLOC(table_size);
 957         if (table_buf == NULL) {
 958                 ERROR("Failed to allocate %zu bytes for temporary lookup table",
 959                       table_size);
 960                 return WIMLIB_ERR_NOMEM;
 961         }
 962         table_buf_ptr = table_buf;
 963
 964         prev_res_offset_in_wim = ~0ULL;
 965         list_for_each_entry(lte, stream_list, lookup_table_list) {
 966
 967                 put_wim_lookup_table_entry(table_buf_ptr++,
 968                                            &lte->out_reshdr,
 969                                            part_number,
 970                                            lte->out_refcnt,
 971                                            lte->hash);
 972                 if (lte->out_reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS &&
 973                     lte->out_res_offset_in_wim != prev_res_offset_in_wim)
 974                 {
 975                         /* Put the main resource entry for the pack.  */
 976
 977                         struct wim_reshdr reshdr;
 978
 979                         reshdr.offset_in_wim = lte->out_res_offset_in_wim;
 980                         reshdr.size_in_wim = lte->out_res_size_in_wim;
 981                         reshdr.uncompressed_size = WIM_PACK_MAGIC_NUMBER;
 982                         reshdr.flags = WIM_RESHDR_FLAG_PACKED_STREAMS;
 983
 984                         DEBUG("Putting main entry for pack: "
 985                               "size_in_wim=%"PRIu64", "
 986                               "offset_in_wim=%"PRIu64", "
 987                               "uncompressed_size=%"PRIu64,
 988                               reshdr.size_in_wim,
 989                               reshdr.offset_in_wim,
 990                               reshdr.uncompressed_size);
 991
 992                         put_wim_lookup_table_entry(table_buf_ptr++,
 993                                                    &reshdr,
 994                                                    part_number,
 995                                                    1, zero_hash);
 996                         prev_res_offset_in_wim = lte->out_res_offset_in_wim;
 997                 }
 998
 999         }
1000         wimlib_assert((u8*)table_buf_ptr - (u8*)table_buf == table_size);
1001
1002         /* Write the lookup table uncompressed.  Although wimlib can handle a
1003          * compressed lookup table, MS software cannot.  */
1004         ret = write_wim_resource_from_buffer(table_buf,
1005                                              table_size,
1006                                              WIM_RESHDR_FLAG_METADATA,
1007                                              out_fd,
1008                                              WIMLIB_COMPRESSION_TYPE_NONE,
1009                                              0,
1010                                              out_reshdr,
1011                                              NULL,
1012                                              write_resource_flags);
1013         FREE(table_buf);
1014         DEBUG("ret=%d", ret);
1015         return ret;
1016 }
1017
1018 int
1019 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
1020 {
1021         lte->real_refcnt = 0;
1022         return 0;
1023 }
1024
1025 int
1026 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
1027 {
1028         lte->out_refcnt = 0;
1029         return 0;
1030 }
1031
1032 int
1033 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *_ignore)
1034 {
1035         if (lte->extracted_file != NULL) {
1036                 FREE(lte->extracted_file);
1037                 lte->extracted_file = NULL;
1038         }
1039         return 0;
1040 }
1041
1042 /* Allocate a stream entry for the contents of the buffer, or re-use an existing
1043  * entry in @lookup_table for the same stream.  */
1044 struct wim_lookup_table_entry *
1045 new_stream_from_data_buffer(const void *buffer, size_t size,
1046                             struct wim_lookup_table *lookup_table)
1047 {
1048         u8 hash[SHA1_HASH_SIZE];
1049         struct wim_lookup_table_entry *lte, *existing_lte;
1050
1051         sha1_buffer(buffer, size, hash);
1052         existing_lte = lookup_stream(lookup_table, hash);
1053         if (existing_lte) {
1054                 wimlib_assert(existing_lte->size == size);
1055                 lte = existing_lte;
1056                 lte->refcnt++;
1057         } else {
1058                 void *buffer_copy;
1059                 lte = new_lookup_table_entry();
1060                 if (lte == NULL)
1061                         return NULL;
1062                 buffer_copy = memdup(buffer, size);
1063                 if (buffer_copy == NULL) {
1064                         free_lookup_table_entry(lte);
1065                         return NULL;
1066                 }
1067                 lte->resource_location  = RESOURCE_IN_ATTACHED_BUFFER;
1068                 lte->attached_buffer    = buffer_copy;
1069                 lte->size               = size;
1070                 copy_hash(lte->hash, hash);
1071                 lookup_table_insert(lookup_table, lte);
1072         }
1073         return lte;
1074 }
1075
1076 /* Calculate the SHA1 message digest of a stream and move it from the list of
1077  * unhashed streams to the stream lookup table, possibly joining it with an
1078  * existing lookup table entry for an identical stream.
1079  *
1080  * @lte:  An unhashed lookup table entry.
1081  * @lookup_table:  Lookup table for the WIM.
1082  * @lte_ret:  On success, write a pointer to the resulting lookup table
1083  *            entry to this location.  This will be the same as @lte
1084  *            if it was inserted into the lookup table, or different if
1085  *            a duplicate stream was found.
1086  *
1087  * Returns 0 on success; nonzero if there is an error reading the stream.
1088  */
1089 int
1090 hash_unhashed_stream(struct wim_lookup_table_entry *lte,
1091                      struct wim_lookup_table *lookup_table,
1092                      struct wim_lookup_table_entry **lte_ret)
1093 {
1094         int ret;
1095         struct wim_lookup_table_entry *duplicate_lte;
1096         struct wim_lookup_table_entry **back_ptr;
1097
1098         wimlib_assert(lte->unhashed);
1099
1100         /* back_ptr must be saved because @back_inode and @back_stream_id are in
1101          * union with the SHA1 message digest and will no longer be valid once
1102          * the SHA1 has been calculated. */
1103         back_ptr = retrieve_lte_pointer(lte);
1104
1105         ret = sha1_stream(lte);
1106         if (ret)
1107                 return ret;
1108
1109         /* Look for a duplicate stream */
1110         duplicate_lte = lookup_stream(lookup_table, lte->hash);
1111         list_del(&lte->unhashed_list);
1112         if (duplicate_lte) {
1113                 /* We have a duplicate stream.  Transfer the reference counts
1114                  * from this stream to the duplicate and update the reference to
1115                  * this stream (in an inode or ads_entry) to point to the
1116                  * duplicate.  The caller is responsible for freeing @lte if
1117                  * needed.  */
1118                 wimlib_assert(!(duplicate_lte->unhashed));
1119                 wimlib_assert(duplicate_lte->size == lte->size);
1120                 duplicate_lte->refcnt += lte->refcnt;
1121                 lte->refcnt = 0;
1122                 *back_ptr = duplicate_lte;
1123                 lte = duplicate_lte;
1124         } else {
1125                 /* No duplicate stream, so we need to insert this stream into
1126                  * the lookup table and treat it as a hashed stream. */
1127                 lookup_table_insert(lookup_table, lte);
1128                 lte->unhashed = 0;
1129         }
1130         *lte_ret = lte;
1131         return 0;
1132 }
1133
1134 void
1135 lte_to_wimlib_resource_entry(const struct wim_lookup_table_entry *lte,
1136                              struct wimlib_resource_entry *wentry)
1137 {
1138         memset(wentry, 0, sizeof(*wentry));
1139
1140         wentry->uncompressed_size = lte->size;
1141         if (lte->resource_location == RESOURCE_IN_WIM) {
1142                 wentry->part_number = lte->rspec->wim->hdr.part_number;
1143                 if (lte->flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
1144                         wentry->compressed_size = 0;
1145                         wentry->offset = lte->offset_in_res;
1146                 } else {
1147                         wentry->compressed_size = lte->rspec->size_in_wim;
1148                         wentry->offset = lte->rspec->offset_in_wim;
1149                 }
1150                 wentry->raw_resource_offset_in_wim = lte->rspec->offset_in_wim;
1151                 /*wentry->raw_resource_uncompressed_size = lte->rspec->uncompressed_size;*/
1152                 wentry->raw_resource_compressed_size = lte->rspec->size_in_wim;
1153         }
1154         copy_hash(wentry->sha1_hash, lte->hash);
1155         wentry->reference_count = lte->refcnt;
1156         wentry->is_compressed = (lte->flags & WIM_RESHDR_FLAG_COMPRESSED) != 0;
1157         wentry->is_metadata = (lte->flags & WIM_RESHDR_FLAG_METADATA) != 0;
1158         wentry->is_free = (lte->flags & WIM_RESHDR_FLAG_FREE) != 0;
1159         wentry->is_spanned = (lte->flags & WIM_RESHDR_FLAG_SPANNED) != 0;
1160         wentry->packed = (lte->flags & WIM_RESHDR_FLAG_PACKED_STREAMS) != 0;
1161 }
1162
1163 struct iterate_lte_context {
1164         wimlib_iterate_lookup_table_callback_t cb;
1165         void *user_ctx;
1166 };
1167
1168 static int
1169 do_iterate_lte(struct wim_lookup_table_entry *lte, void *_ctx)
1170 {
1171         struct iterate_lte_context *ctx = _ctx;
1172         struct wimlib_resource_entry entry;
1173
1174         lte_to_wimlib_resource_entry(lte, &entry);
1175         return (*ctx->cb)(&entry, ctx->user_ctx);
1176 }
1177
1178 /* API function documented in wimlib.h  */
1179 WIMLIBAPI int
1180 wimlib_iterate_lookup_table(WIMStruct *wim, int flags,
1181                             wimlib_iterate_lookup_table_callback_t cb,
1182                             void *user_ctx)
1183 {
1184         if (flags != 0)
1185                 return WIMLIB_ERR_INVALID_PARAM;
1186
1187         struct iterate_lte_context ctx = {
1188                 .cb = cb,
1189                 .user_ctx = user_ctx,
1190         };
1191         if (wim->hdr.part_number == 1) {
1192                 int ret;
1193                 for (int i = 0; i < wim->hdr.image_count; i++) {
1194                         ret = do_iterate_lte(wim->image_metadata[i]->metadata_lte,
1195                                              &ctx);
1196                         if (ret)
1197                                 return ret;
1198                 }
1199         }
1200         return for_lookup_table_entry(wim->lookup_table, do_iterate_lte, &ctx);
1201 }