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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.
   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/endianness.h"
  32 #include "wimlib/error.h"
  33 #include "wimlib/file_io.h"
  34 #include "wimlib/lookup_table.h"
  35 #include "wimlib/metadata.h"
  36 #include "wimlib/paths.h"
  37 #include "wimlib/resource.h"
  38 #include "wimlib/util.h"
  39
  40 #include <errno.h>
  41 #include <stdlib.h>
  42 #ifdef WITH_FUSE
  43 #  include <unistd.h> /* for unlink() */
  44 #endif
  45
  46 struct wim_lookup_table *
  47 new_lookup_table(size_t capacity)
  48 {
  49         struct wim_lookup_table *table;
  50         struct hlist_head *array;
  51
  52         table = CALLOC(1, sizeof(struct wim_lookup_table));
  53         if (table) {
  54                 array = CALLOC(capacity, sizeof(array[0]));
  55                 if (array) {
  56                         table->num_entries = 0;
  57                         table->capacity = capacity;
  58                         table->array = array;
  59                 } else {
  60                         FREE(table);
  61                         table = NULL;
  62                         ERROR("Failed to allocate memory for lookup table "
  63                               "with capacity %zu", capacity);
  64                 }
  65         }
  66         return table;
  67 }
  68
  69 struct wim_lookup_table_entry *
  70 new_lookup_table_entry(void)
  71 {
  72         struct wim_lookup_table_entry *lte;
  73
  74         lte = CALLOC(1, sizeof(struct wim_lookup_table_entry));
  75         if (lte) {
  76                 lte->part_number  = 1;
  77                 lte->refcnt       = 1;
  78         } else {
  79                 ERROR("Out of memory (tried to allocate %zu bytes for "
  80                       "lookup table entry)",
  81                       sizeof(struct wim_lookup_table_entry));
  82         }
  83         return lte;
  84 }
  85
  86 struct wim_lookup_table_entry *
  87 clone_lookup_table_entry(const struct wim_lookup_table_entry *old)
  88 {
  89         struct wim_lookup_table_entry *new;
  90
  91         new = memdup(old, sizeof(struct wim_lookup_table_entry));
  92         if (!new)
  93                 return NULL;
  94
  95         new->extracted_file = NULL;
  96         switch (new->resource_location) {
  97 #ifdef __WIN32__
  98         case RESOURCE_WIN32:
  99         case RESOURCE_WIN32_ENCRYPTED:
 100 #else
 101         case RESOURCE_IN_FILE_ON_DISK:
 102 #endif
 103 #ifdef WITH_FUSE
 104         case RESOURCE_IN_STAGING_FILE:
 105                 BUILD_BUG_ON((void*)&old->file_on_disk !=
 106                              (void*)&old->staging_file_name);
 107 #endif
 108                 new->file_on_disk = TSTRDUP(old->file_on_disk);
 109                 if (!new->file_on_disk)
 110                         goto out_free;
 111                 break;
 112         case RESOURCE_IN_ATTACHED_BUFFER:
 113                 new->attached_buffer = memdup(old->attached_buffer,
 114                                               wim_resource_size(old));
 115                 if (!new->attached_buffer)
 116                         goto out_free;
 117                 break;
 118 #ifdef WITH_NTFS_3G
 119         case RESOURCE_IN_NTFS_VOLUME:
 120                 if (old->ntfs_loc) {
 121                         struct ntfs_location *loc;
 122                         loc = memdup(old->ntfs_loc, sizeof(struct ntfs_location));
 123                         if (!loc)
 124                                 goto out_free;
 125                         loc->path = NULL;
 126                         loc->stream_name = NULL;
 127                         new->ntfs_loc = loc;
 128                         loc->path = STRDUP(old->ntfs_loc->path);
 129                         if (!loc->path)
 130                                 goto out_free;
 131                         if (loc->stream_name_nchars) {
 132                                 loc->stream_name = memdup(old->ntfs_loc->stream_name,
 133                                                           loc->stream_name_nchars * 2);
 134                                 if (!loc->stream_name)
 135                                         goto out_free;
 136                         }
 137                 }
 138                 break;
 139 #endif
 140         default:
 141                 break;
 142         }
 143         return new;
 144 out_free:
 145         free_lookup_table_entry(new);
 146         return NULL;
 147 }
 148
 149 void
 150 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 151 {
 152         if (lte) {
 153                 switch (lte->resource_location) {
 154         #ifdef __WIN32__
 155                 case RESOURCE_WIN32:
 156                 case RESOURCE_WIN32_ENCRYPTED:
 157         #else
 158                 case RESOURCE_IN_FILE_ON_DISK:
 159         #endif
 160         #ifdef WITH_FUSE
 161                 case RESOURCE_IN_STAGING_FILE:
 162                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 163                                      (void*)&lte->staging_file_name);
 164         #endif
 165                 case RESOURCE_IN_ATTACHED_BUFFER:
 166                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 167                                      (void*)&lte->attached_buffer);
 168                         FREE(lte->file_on_disk);
 169                         break;
 170 #ifdef WITH_NTFS_3G
 171                 case RESOURCE_IN_NTFS_VOLUME:
 172                         if (lte->ntfs_loc) {
 173                                 FREE(lte->ntfs_loc->path);
 174                                 FREE(lte->ntfs_loc->stream_name);
 175                                 FREE(lte->ntfs_loc);
 176                         }
 177                         break;
 178 #endif
 179                 default:
 180                         break;
 181                 }
 182                 FREE(lte);
 183         }
 184 }
 185
 186 static int
 187 do_free_lookup_table_entry(struct wim_lookup_table_entry *entry, void *ignore)
 188 {
 189         free_lookup_table_entry(entry);
 190         return 0;
 191 }
 192
 193
 194 void
 195 free_lookup_table(struct wim_lookup_table *table)
 196 {
 197         DEBUG2("Freeing lookup table");
 198         if (table) {
 199                 if (table->array) {
 200                         for_lookup_table_entry(table,
 201                                                do_free_lookup_table_entry,
 202                                                NULL);
 203                         FREE(table->array);
 204                 }
 205                 FREE(table);
 206         }
 207 }
 208
 209 /*
 210  * Inserts an entry into the lookup table.
 211  *
 212  * @table:      A pointer to the lookup table.
 213  * @lte:        A pointer to the entry to insert.
 214  */
 215 void
 216 lookup_table_insert(struct wim_lookup_table *table,
 217                     struct wim_lookup_table_entry *lte)
 218 {
 219         size_t i = lte->hash_short % table->capacity;
 220         hlist_add_head(&lte->hash_list, &table->array[i]);
 221
 222         /* XXX Make the table grow when too many entries have been inserted. */
 223         table->num_entries++;
 224 }
 225
 226 static void
 227 finalize_lte(struct wim_lookup_table_entry *lte)
 228 {
 229         #ifdef WITH_FUSE
 230         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 231                 unlink(lte->staging_file_name);
 232                 list_del(&lte->unhashed_list);
 233         }
 234         #endif
 235         free_lookup_table_entry(lte);
 236 }
 237
 238 /* Decrements the reference count for the lookup table entry @lte.  If its
 239  * reference count reaches 0, it is unlinked from the lookup table.  If,
 240  * furthermore, the entry has no opened file descriptors associated with it, the
 241  * entry is freed.  */
 242 void
 243 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 244                      struct wim_lookup_table *table)
 245 {
 246         wimlib_assert(lte != NULL);
 247         wimlib_assert(lte->refcnt != 0);
 248         if (--lte->refcnt == 0) {
 249                 if (lte->unhashed)
 250                         list_del(&lte->unhashed_list);
 251                 else
 252                         lookup_table_unlink(table, lte);
 253         #ifdef WITH_FUSE
 254                 if (lte->num_opened_fds == 0)
 255         #endif
 256                         finalize_lte(lte);
 257         }
 258 }
 259
 260 #ifdef WITH_FUSE
 261 void
 262 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 263 {
 264         if (lte->num_opened_fds != 0)
 265                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 266                         finalize_lte(lte);
 267 }
 268 #endif
 269
 270 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 271  * return nonzero if any call to the function returns nonzero. */
 272 int
 273 for_lookup_table_entry(struct wim_lookup_table *table,
 274                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 275                        void *arg)
 276 {
 277         struct wim_lookup_table_entry *lte;
 278         struct hlist_node *pos, *tmp;
 279         int ret;
 280
 281         for (size_t i = 0; i < table->capacity; i++) {
 282                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 283                                           hash_list)
 284                 {
 285                         wimlib_assert2(!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA));
 286                         ret = visitor(lte, arg);
 287                         if (ret)
 288                                 return ret;
 289                 }
 290         }
 291         return 0;
 292 }
 293
 294 int
 295 cmp_streams_by_wim_position(const void *p1, const void *p2)
 296 {
 297         const struct wim_lookup_table_entry *lte1, *lte2;
 298         lte1 = *(const struct wim_lookup_table_entry**)p1;
 299         lte2 = *(const struct wim_lookup_table_entry**)p2;
 300         if (lte1->resource_entry.offset < lte2->resource_entry.offset)
 301                 return -1;
 302         else if (lte1->resource_entry.offset > lte2->resource_entry.offset)
 303                 return 1;
 304         else
 305                 return 0;
 306 }
 307
 308
 309 static int
 310 add_lte_to_array(struct wim_lookup_table_entry *lte,
 311                  void *_pp)
 312 {
 313         struct wim_lookup_table_entry ***pp = _pp;
 314         *(*pp)++ = lte;
 315         return 0;
 316 }
 317
 318 /* Iterate through the lookup table entries, but first sort them by stream
 319  * offset in the WIM.  Caution: this is intended to be used when the stream
 320  * offset field has actually been set. */
 321 int
 322 for_lookup_table_entry_pos_sorted(struct wim_lookup_table *table,
 323                                   int (*visitor)(struct wim_lookup_table_entry *,
 324                                                  void *),
 325                                   void *arg)
 326 {
 327         struct wim_lookup_table_entry **lte_array, **p;
 328         size_t num_streams = table->num_entries;
 329         int ret;
 330
 331         lte_array = MALLOC(num_streams * sizeof(lte_array[0]));
 332         if (!lte_array)
 333                 return WIMLIB_ERR_NOMEM;
 334         p = lte_array;
 335         for_lookup_table_entry(table, add_lte_to_array, &p);
 336
 337         wimlib_assert(p == lte_array + num_streams);
 338
 339         qsort(lte_array, num_streams, sizeof(lte_array[0]),
 340               cmp_streams_by_wim_position);
 341         ret = 0;
 342         for (size_t i = 0; i < num_streams; i++) {
 343                 ret = visitor(lte_array[i], arg);
 344                 if (ret)
 345                         break;
 346         }
 347         FREE(lte_array);
 348         return ret;
 349 }
 350
 351 /* On-disk format of a WIM lookup table entry (stream entry). */
 352 struct wim_lookup_table_entry_disk {
 353         /* Location, offset, compression status, and metadata status of the
 354          * stream. */
 355         struct resource_entry_disk resource_entry;
 356
 357         /* Which part of the split WIM this stream is in; indexed from 1. */
 358         le16 part_number;
 359
 360         /* Reference count of this stream over all WIM images. */
 361         le32 refcnt;
 362
 363         /* SHA1 message digest of the uncompressed data of this stream, or
 364          * optionally all zeroes if this stream is of zero length. */
 365         u8 hash[SHA1_HASH_SIZE];
 366 } _packed_attribute;
 367
 368 #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
 369
 370 /*
 371  * Reads the lookup table from a WIM file.
 372  *
 373  * Saves lookup table entries for non-metadata streams in a hash table, and
 374  * saves the metadata entry for each image in a special per-image location (the
 375  * image_metadata array).
 376  */
 377 int
 378 read_lookup_table(WIMStruct *w)
 379 {
 380         int ret;
 381         size_t num_entries;
 382         struct wim_lookup_table *table;
 383         struct wim_lookup_table_entry *cur_entry, *duplicate_entry;
 384         struct wim_lookup_table_entry_disk
 385                         table_buf[BUFFER_SIZE / sizeof(struct wim_lookup_table_entry_disk)]
 386                                 _aligned_attribute(8);
 387
 388         BUILD_BUG_ON(sizeof(struct wim_lookup_table_entry_disk) !=
 389                      WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE);
 390
 391         off_t offset;
 392         size_t buf_entries_remaining;
 393         const struct wim_lookup_table_entry_disk *disk_entry;
 394
 395         DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
 396               w->hdr.lookup_table_res_entry.offset,
 397               w->hdr.lookup_table_res_entry.original_size);
 398
 399         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
 400                 ERROR("Didn't expect a compressed lookup table!");
 401                 ERROR("Ask the author to implement support for this.");
 402                 return WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
 403         }
 404
 405         num_entries = w->hdr.lookup_table_res_entry.size /
 406                       sizeof(struct wim_lookup_table_entry_disk);
 407         table = new_lookup_table(num_entries * 2 + 1);
 408         if (!table) {
 409                 ERROR("Failed to allocate stream hash table of size %zu",
 410                       num_entries * 2 + 1);
 411                 return WIMLIB_ERR_NOMEM;
 412         }
 413
 414         w->current_image = 0;
 415         offset = w->hdr.lookup_table_res_entry.offset;
 416         buf_entries_remaining = 0;
 417         for (; num_entries != 0;
 418              num_entries--, buf_entries_remaining--, disk_entry++)
 419         {
 420                 if (buf_entries_remaining == 0) {
 421                         size_t entries_to_read, bytes_to_read;
 422
 423                         entries_to_read = min(ARRAY_LEN(table_buf), num_entries);
 424                         bytes_to_read = entries_to_read * sizeof(struct wim_lookup_table_entry_disk);
 425                         if (full_pread(w->in_fd, table_buf,
 426                                        bytes_to_read, offset) != bytes_to_read)
 427                         {
 428                                 ERROR_WITH_ERRNO("Error reading lookup table "
 429                                                  "(offset=%"PRIu64")", offset);
 430                                 ret = WIMLIB_ERR_READ;
 431                                 goto out_free_lookup_table;
 432                         }
 433                         offset += bytes_to_read;
 434                         disk_entry = table_buf;
 435                         buf_entries_remaining = entries_to_read;
 436                 }
 437                 cur_entry = new_lookup_table_entry();
 438                 if (!cur_entry) {
 439                         ret = WIMLIB_ERR_NOMEM;
 440                         goto out_free_lookup_table;
 441                 }
 442
 443                 cur_entry->wim = w;
 444                 cur_entry->resource_location = RESOURCE_IN_WIM;
 445                 get_resource_entry(&disk_entry->resource_entry, &cur_entry->resource_entry);
 446                 cur_entry->part_number = le16_to_cpu(disk_entry->part_number);
 447                 cur_entry->refcnt = le32_to_cpu(disk_entry->refcnt);
 448                 copy_hash(cur_entry->hash, disk_entry->hash);
 449
 450                 if (cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 451                         cur_entry->compression_type = w->compression_type;
 452                 else
 453                         BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_NONE != 0);
 454
 455                 if (cur_entry->part_number != w->hdr.part_number) {
 456                         WARNING("A lookup table entry in part %hu of the WIM "
 457                                 "points to part %hu (ignoring it)",
 458                                 w->hdr.part_number, cur_entry->part_number);
 459                         free_lookup_table_entry(cur_entry);
 460                         continue;
 461                 }
 462
 463                 if (is_zero_hash(cur_entry->hash)) {
 464                         WARNING("The WIM lookup table contains an entry with a "
 465                                 "SHA1 message digest of all 0's (ignoring it)");
 466                         free_lookup_table_entry(cur_entry);
 467                         continue;
 468                 }
 469
 470                 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 471                     && (cur_entry->resource_entry.size !=
 472                         cur_entry->resource_entry.original_size))
 473                 {
 474                         if (wimlib_print_errors) {
 475                                 WARNING("Found uncompressed resource with "
 476                                         "original size (%"PRIu64") not the same "
 477                                         "as compressed size (%"PRIu64")",
 478                                         cur_entry->resource_entry.original_size,
 479                                         cur_entry->resource_entry.size);
 480                                 if (cur_entry->resource_entry.original_size) {
 481                                         WARNING("Overriding compressed size with original size.");
 482                                         cur_entry->resource_entry.size =
 483                                                 cur_entry->resource_entry.original_size;
 484                                 } else {
 485                                         WARNING("Overriding original size with compressed size");
 486                                         cur_entry->resource_entry.original_size =
 487                                                 cur_entry->resource_entry.size;
 488                                 }
 489                         }
 490                 }
 491
 492                 if (cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 493                         /* Lookup table entry for a metadata resource */
 494                         if (cur_entry->refcnt != 1) {
 495                                 if (wimlib_print_errors) {
 496                                         ERROR("Found metadata resource with refcnt != 1:");
 497                                         print_lookup_table_entry(cur_entry, stderr);
 498                                 }
 499                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 500                                 goto out_free_cur_entry;
 501                         }
 502
 503                         if (w->hdr.part_number != 1) {
 504                                 WARNING("Ignoring metadata resource found in a "
 505                                         "non-first part of the split WIM");
 506                                 free_lookup_table_entry(cur_entry);
 507                                 continue;
 508                         }
 509                         if (w->current_image == w->hdr.image_count) {
 510                                 WARNING("The WIM header says there are %u images "
 511                                         "in the WIM, but we found more metadata "
 512                                         "resources than this (ignoring the extra)",
 513                                         w->hdr.image_count);
 514                                 free_lookup_table_entry(cur_entry);
 515                                 continue;
 516                         }
 517
 518                         /* Notice very carefully:  We are assigning the metadata
 519                          * resources in the exact order mirrored by their lookup
 520                          * table entries on disk, which is the behavior of
 521                          * Microsoft's software.  In particular, this overrides
 522                          * the actual locations of the metadata resources
 523                          * themselves in the WIM file as well as any information
 524                          * written in the XML data. */
 525                         DEBUG("Found metadata resource for image %u at "
 526                               "offset %"PRIu64".",
 527                               w->current_image + 1,
 528                               cur_entry->resource_entry.offset);
 529                         w->image_metadata[
 530                                 w->current_image++]->metadata_lte = cur_entry;
 531                 } else {
 532                         /* Lookup table entry for a stream that is not a
 533                          * metadata resource */
 534                         duplicate_entry = __lookup_resource(table, cur_entry->hash);
 535                         if (duplicate_entry) {
 536                                 if (wimlib_print_errors) {
 537                                         WARNING("The WIM lookup table contains two entries with the "
 538                                               "same SHA1 message digest!");
 539                                         WARNING("The first entry is:");
 540                                         print_lookup_table_entry(duplicate_entry, stderr);
 541                                         WARNING("The second entry is:");
 542                                         print_lookup_table_entry(cur_entry, stderr);
 543                                 }
 544                                 free_lookup_table_entry(cur_entry);
 545                                 continue;
 546                         } else {
 547                                 lookup_table_insert(table, cur_entry);
 548                         }
 549                 }
 550         }
 551
 552         if (w->hdr.part_number == 1 && w->current_image != w->hdr.image_count) {
 553                 WARNING("The header of \"%"TS"\" says there are %u images in\n"
 554                         "          the WIM, but we only found %d metadata resources!  Acting as if\n"
 555                         "          the header specified only %d images instead.",
 556                         w->filename, w->hdr.image_count,
 557                         w->current_image, w->current_image);
 558                 for (int i = w->current_image; i < w->hdr.image_count; i++)
 559                         put_image_metadata(w->image_metadata[i], NULL);
 560                 w->hdr.image_count = w->current_image;
 561         }
 562         DEBUG("Done reading lookup table.");
 563         w->lookup_table = table;
 564         ret = 0;
 565         goto out;
 566 out_free_cur_entry:
 567         FREE(cur_entry);
 568 out_free_lookup_table:
 569         free_lookup_table(table);
 570 out:
 571         w->current_image = 0;
 572         return ret;
 573 }
 574
 575
 576 static void
 577 write_lookup_table_entry(const struct wim_lookup_table_entry *lte,
 578                          struct wim_lookup_table_entry_disk *disk_entry)
 579 {
 580         put_resource_entry(&lte->output_resource_entry, &disk_entry->resource_entry);
 581         disk_entry->part_number = cpu_to_le16(lte->part_number);
 582         disk_entry->refcnt = cpu_to_le32(lte->out_refcnt);
 583         copy_hash(disk_entry->hash, lte->hash);
 584 }
 585
 586 int
 587 write_lookup_table_from_stream_list(struct list_head *stream_list,
 588                                     int out_fd,
 589                                     struct resource_entry *out_res_entry)
 590 {
 591         int ret;
 592         off_t start_offset;
 593         struct wim_lookup_table_entry_disk
 594                         table_buf[BUFFER_SIZE / sizeof(struct wim_lookup_table_entry_disk)]
 595                                 _aligned_attribute(8);
 596         size_t table_size;
 597         size_t bytes_to_write;
 598         struct wim_lookup_table_entry *lte;
 599         size_t cur_idx;
 600
 601         start_offset = filedes_offset(out_fd);
 602         if (start_offset == -1)
 603                 goto write_error;
 604
 605         table_size = 0;
 606         cur_idx = 0;
 607         list_for_each_entry(lte, stream_list, lookup_table_list) {
 608                 if (cur_idx == ARRAY_LEN(table_buf)) {
 609                         bytes_to_write = sizeof(table_buf);
 610                         if (full_write(out_fd, table_buf,
 611                                        bytes_to_write) != bytes_to_write)
 612                                 goto write_error;
 613                         table_size += bytes_to_write;
 614                         cur_idx = 0;
 615                 }
 616                 write_lookup_table_entry(lte, &table_buf[cur_idx]);
 617                 cur_idx++;
 618         }
 619         if (cur_idx != 0) {
 620                 bytes_to_write = cur_idx * sizeof(struct wim_lookup_table_entry_disk);
 621                 if (full_write(out_fd, table_buf,
 622                                bytes_to_write) != bytes_to_write)
 623                         goto write_error;
 624                 table_size += bytes_to_write;
 625         }
 626         out_res_entry->offset        = start_offset;
 627         out_res_entry->size          = table_size;
 628         out_res_entry->original_size = table_size;
 629         out_res_entry->flags         = WIM_RESHDR_FLAG_METADATA;
 630         ret = 0;
 631 out:
 632         return ret;
 633 write_error:
 634         ERROR_WITH_ERRNO("Failed to write lookup table");
 635         ret = WIMLIB_ERR_WRITE;
 636         goto out;
 637 }
 638
 639 static int
 640 append_lookup_table_entry(struct wim_lookup_table_entry *lte, void *_list)
 641 {
 642         if (lte->out_refcnt != 0)
 643                 list_add_tail(&lte->lookup_table_list, (struct list_head*)_list);
 644         return 0;
 645 }
 646
 647 /* Writes the WIM lookup table to the output file. */
 648 int
 649 write_lookup_table(WIMStruct *w, int image, struct resource_entry *out_res_entry)
 650 {
 651         LIST_HEAD(stream_list);
 652         int start_image;
 653         int end_image;
 654
 655         if (image == WIMLIB_ALL_IMAGES) {
 656                 start_image = 1;
 657                 end_image = w->hdr.image_count;
 658         } else {
 659                 start_image = image;
 660                 end_image = image;
 661         }
 662
 663         for (int i = start_image; i <= end_image; i++) {
 664                 struct wim_lookup_table_entry *metadata_lte;
 665
 666                 metadata_lte = w->image_metadata[i - 1]->metadata_lte;
 667                 metadata_lte->out_refcnt = 1;
 668                 metadata_lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
 669                 append_lookup_table_entry(metadata_lte, &stream_list);
 670         }
 671         for_lookup_table_entry(w->lookup_table,
 672                                append_lookup_table_entry,
 673                                &stream_list);
 674         return write_lookup_table_from_stream_list(&stream_list,
 675                                                    w->out_fd,
 676                                                    out_res_entry);
 677 }
 678
 679 int
 680 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
 681 {
 682         lte->real_refcnt = 0;
 683         return 0;
 684 }
 685
 686 int
 687 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
 688 {
 689         lte->out_refcnt = 0;
 690         return 0;
 691 }
 692
 693 int
 694 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *_ignore)
 695 {
 696         if (lte->extracted_file != NULL) {
 697                 FREE(lte->extracted_file);
 698                 lte->extracted_file = NULL;
 699         }
 700         return 0;
 701 }
 702
 703 void
 704 print_lookup_table_entry(const struct wim_lookup_table_entry *lte, FILE *out)
 705 {
 706         if (!lte) {
 707                 tputc(T('\n'), out);
 708                 return;
 709         }
 710         tfprintf(out, T("Offset            = %"PRIu64" bytes\n"),
 711                  lte->resource_entry.offset);
 712
 713         tfprintf(out, T("Size              = %"PRIu64" bytes\n"),
 714                  (u64)lte->resource_entry.size);
 715
 716         tfprintf(out, T("Original size     = %"PRIu64" bytes\n"),
 717                  lte->resource_entry.original_size);
 718
 719         tfprintf(out, T("Part Number       = %hu\n"), lte->part_number);
 720         tfprintf(out, T("Reference Count   = %u\n"), lte->refcnt);
 721
 722         if (lte->unhashed) {
 723                 tfprintf(out, T("(Unhashed: inode %p, stream_id = %u)\n"),
 724                          lte->back_inode, lte->back_stream_id);
 725         } else {
 726                 tfprintf(out, T("Hash              = 0x"));
 727                 print_hash(lte->hash, out);
 728                 tputc(T('\n'), out);
 729         }
 730
 731         tfprintf(out, T("Flags             = "));
 732         u8 flags = lte->resource_entry.flags;
 733         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 734                 tfputs(T("WIM_RESHDR_FLAG_COMPRESSED, "), out);
 735         if (flags & WIM_RESHDR_FLAG_FREE)
 736                 tfputs(T("WIM_RESHDR_FLAG_FREE, "), out);
 737         if (flags & WIM_RESHDR_FLAG_METADATA)
 738                 tfputs(T("WIM_RESHDR_FLAG_METADATA, "), out);
 739         if (flags & WIM_RESHDR_FLAG_SPANNED)
 740                 tfputs(T("WIM_RESHDR_FLAG_SPANNED, "), out);
 741         tputc(T('\n'), out);
 742         switch (lte->resource_location) {
 743         case RESOURCE_IN_WIM:
 744                 if (lte->wim->filename) {
 745                         tfprintf(out, T("WIM file          = `%"TS"'\n"),
 746                                  lte->wim->filename);
 747                 }
 748                 break;
 749 #ifdef __WIN32__
 750         case RESOURCE_WIN32:
 751         case RESOURCE_WIN32_ENCRYPTED:
 752 #else
 753         case RESOURCE_IN_FILE_ON_DISK:
 754 #endif
 755                 tfprintf(out, T("File on Disk      = `%"TS"'\n"),
 756                          lte->file_on_disk);
 757                 break;
 758 #ifdef WITH_FUSE
 759         case RESOURCE_IN_STAGING_FILE:
 760                 tfprintf(out, T("Staging File      = `%"TS"'\n"),
 761                                 lte->staging_file_name);
 762                 break;
 763 #endif
 764         default:
 765                 break;
 766         }
 767         tputc(T('\n'), out);
 768 }
 769
 770 static int
 771 do_print_lookup_table_entry(struct wim_lookup_table_entry *lte, void *fp)
 772 {
 773         print_lookup_table_entry(lte, (FILE*)fp);
 774         return 0;
 775 }
 776
 777 /*
 778  * Prints the lookup table of a WIM file.
 779  */
 780 WIMLIBAPI void
 781 wimlib_print_lookup_table(WIMStruct *wim)
 782 {
 783         for (int i = 0; i < wim->hdr.image_count; i++)
 784                 print_lookup_table_entry(wim->image_metadata[i]->metadata_lte, stdout);
 785         for_lookup_table_entry(wim->lookup_table,
 786                                do_print_lookup_table_entry,
 787                                stdout);
 788 }
 789
 790 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 791  * lookup table, or NULL if there is none.  */
 792 struct wim_lookup_table_entry *
 793 __lookup_resource(const struct wim_lookup_table *table, const u8 hash[])
 794 {
 795         size_t i;
 796         struct wim_lookup_table_entry *lte;
 797         struct hlist_node *pos;
 798
 799         wimlib_assert(table != NULL);
 800         wimlib_assert(hash != NULL);
 801
 802         i = *(size_t*)hash % table->capacity;
 803         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 804                 if (hashes_equal(hash, lte->hash))
 805                         return lte;
 806         return NULL;
 807 }
 808
 809 #ifdef WITH_FUSE
 810 /*
 811  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 812  * given a path name.
 813  *
 814  * This is only for pre-resolved inodes.
 815  */
 816 int
 817 lookup_resource(WIMStruct *w,
 818                 const tchar *path,
 819                 int lookup_flags,
 820                 struct wim_dentry **dentry_ret,
 821                 struct wim_lookup_table_entry **lte_ret,
 822                 u16 *stream_idx_ret)
 823 {
 824         struct wim_dentry *dentry;
 825         struct wim_lookup_table_entry *lte;
 826         u16 stream_idx;
 827         const tchar *stream_name = NULL;
 828         struct wim_inode *inode;
 829         tchar *p = NULL;
 830
 831         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 832                 stream_name = path_stream_name(path);
 833                 if (stream_name) {
 834                         p = (tchar*)stream_name - 1;
 835                         *p = T('\0');
 836                 }
 837         }
 838
 839         dentry = get_dentry(w, path);
 840         if (p)
 841                 *p = T(':');
 842         if (!dentry)
 843                 return -errno;
 844
 845         inode = dentry->d_inode;
 846
 847         if (!inode->i_resolved)
 848                 if (inode_resolve_ltes(inode, w->lookup_table))
 849                         return -EIO;
 850
 851         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
 852               && inode_is_directory(inode))
 853                 return -EISDIR;
 854
 855         if (stream_name) {
 856                 struct wim_ads_entry *ads_entry;
 857                 u16 ads_idx;
 858                 ads_entry = inode_get_ads_entry(inode, stream_name,
 859                                                 &ads_idx);
 860                 if (ads_entry) {
 861                         stream_idx = ads_idx + 1;
 862                         lte = ads_entry->lte;
 863                         goto out;
 864                 } else {
 865                         return -ENOENT;
 866                 }
 867         } else {
 868                 lte = inode->i_lte;
 869                 stream_idx = 0;
 870         }
 871 out:
 872         if (dentry_ret)
 873                 *dentry_ret = dentry;
 874         if (lte_ret)
 875                 *lte_ret = lte;
 876         if (stream_idx_ret)
 877                 *stream_idx_ret = stream_idx;
 878         return 0;
 879 }
 880 #endif
 881
 882 /* Resolve an inode's lookup table entries
 883  *
 884  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
 885  * lookup table) with pointers directly to the lookup table entries.  A circular
 886  * linked list of streams sharing the same lookup table entry is created.
 887  *
 888  * This function always succeeds; unresolved lookup table entries are given a
 889  * NULL pointer.
 890  */
 891 int
 892 inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table)
 893 {
 894         const u8 *hash;
 895
 896         if (!inode->i_resolved) {
 897                 struct wim_lookup_table_entry *lte, *ads_lte;
 898
 899                 /* Resolve the default file stream */
 900                 lte = NULL;
 901                 hash = inode->i_hash;
 902                 if (!is_zero_hash(hash)) {
 903                         lte = __lookup_resource(table, hash);
 904                         if (unlikely(!lte))
 905                                 goto resource_not_found;
 906                 }
 907
 908                 /* Resolve the alternate data streams */
 909                 struct wim_lookup_table_entry *ads_ltes[inode->i_num_ads];
 910                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 911                         struct wim_ads_entry *cur_entry;
 912
 913                         ads_lte = NULL;
 914                         cur_entry = &inode->i_ads_entries[i];
 915                         hash = cur_entry->hash;
 916                         if (!is_zero_hash(hash)) {
 917                                 ads_lte = __lookup_resource(table, hash);
 918                                 if (unlikely(!ads_lte))
 919                                         goto resource_not_found;
 920                         }
 921                         ads_ltes[i] = ads_lte;
 922                 }
 923                 inode->i_lte = lte;
 924                 for (u16 i = 0; i < inode->i_num_ads; i++)
 925                         inode->i_ads_entries[i].lte = ads_ltes[i];
 926                 inode->i_resolved = 1;
 927         }
 928         return 0;
 929 resource_not_found:
 930         if (wimlib_print_errors) {
 931                 ERROR("\"%"TS"\": resource not found", inode_first_full_path(inode));
 932                 tfprintf(stderr, T("        SHA-1 message digest of missing resource:\n        "));
 933                 print_hash(hash, stderr);
 934                 tputc(T('\n'), stderr);
 935         }
 936         return WIMLIB_ERR_RESOURCE_NOT_FOUND;
 937 }
 938
 939 void
 940 inode_unresolve_ltes(struct wim_inode *inode)
 941 {
 942         if (inode->i_resolved) {
 943                 if (inode->i_lte)
 944                         copy_hash(inode->i_hash, inode->i_lte->hash);
 945                 else
 946                         zero_out_hash(inode->i_hash);
 947
 948                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 949                         if (inode->i_ads_entries[i].lte)
 950                                 copy_hash(inode->i_ads_entries[i].hash,
 951                                           inode->i_ads_entries[i].lte->hash);
 952                         else
 953                                 zero_out_hash(inode->i_ads_entries[i].hash);
 954                 }
 955                 inode->i_resolved = 0;
 956         }
 957 }
 958
 959 /*
 960  * Returns the lookup table entry for stream @stream_idx of the inode, where
 961  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
 962  * corresponds to an alternate data stream.
 963  *
 964  * This works for both resolved and un-resolved inodes.
 965  */
 966 struct wim_lookup_table_entry *
 967 inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx,
 968                  const struct wim_lookup_table *table)
 969 {
 970         if (inode->i_resolved)
 971                 return inode_stream_lte_resolved(inode, stream_idx);
 972         else
 973                 return inode_stream_lte_unresolved(inode, stream_idx, table);
 974 }
 975
 976 struct wim_lookup_table_entry *
 977 inode_unnamed_lte_resolved(const struct wim_inode *inode)
 978 {
 979         wimlib_assert(inode->i_resolved);
 980         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
 981                 if (inode_stream_name_nbytes(inode, i) == 0 &&
 982                     !is_zero_hash(inode_stream_hash_resolved(inode, i)))
 983                 {
 984                         return inode_stream_lte_resolved(inode, i);
 985                 }
 986         }
 987         return NULL;
 988 }
 989
 990 struct wim_lookup_table_entry *
 991 inode_unnamed_lte_unresolved(const struct wim_inode *inode,
 992                              const struct wim_lookup_table *table)
 993 {
 994         wimlib_assert(!inode->i_resolved);
 995         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
 996                 if (inode_stream_name_nbytes(inode, i) == 0 &&
 997                     !is_zero_hash(inode_stream_hash_unresolved(inode, i)))
 998                 {
 999                         return inode_stream_lte_unresolved(inode, i, table);
1000                 }
1001         }
1002         return NULL;
1003 }
1004
1005 /* Return the lookup table entry for the unnamed data stream of an inode, or
1006  * NULL if there is none.
1007  *
1008  * You'd think this would be easier than it actually is, since the unnamed data
1009  * stream should be the one referenced from the inode itself.  Alas, if there
1010  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
1011  * data stream in one of the alternate data streams instead of inside the WIM
1012  * dentry itself.  So we need to check the alternate data streams too.
1013  *
1014  * Also, note that a dentry may appear to have more than one unnamed stream, but
1015  * if the SHA1 message digest is all 0's then the corresponding stream does not
1016  * really "count" (this is the case for the inode's own file stream when the
1017  * file stream that should be there is actually in one of the alternate stream
1018  * entries.).  This is despite the fact that we may need to extract such a
1019  * missing entry as an empty file or empty named data stream.
1020  */
1021 struct wim_lookup_table_entry *
1022 inode_unnamed_lte(const struct wim_inode *inode,
1023                   const struct wim_lookup_table *table)
1024 {
1025         if (inode->i_resolved)
1026                 return inode_unnamed_lte_resolved(inode);
1027         else
1028                 return inode_unnamed_lte_unresolved(inode, table);
1029 }
1030
1031 static int
1032 lte_add_stream_size(struct wim_lookup_table_entry *lte, void *total_bytes_p)
1033 {
1034         *(u64*)total_bytes_p += lte->resource_entry.size;
1035         return 0;
1036 }
1037
1038 u64
1039 lookup_table_total_stream_size(struct wim_lookup_table *table)
1040 {
1041         u64 total_size = 0;
1042         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
1043         return total_size;
1044 }
1045
1046 struct wim_lookup_table_entry **
1047 retrieve_lte_pointer(struct wim_lookup_table_entry *lte)
1048 {
1049         wimlib_assert(lte->unhashed);
1050         struct wim_inode *inode = lte->back_inode;
1051         u32 stream_id = lte->back_stream_id;
1052         if (stream_id == 0)
1053                 return &inode->i_lte;
1054         else
1055                 for (u16 i = 0; i < inode->i_num_ads; i++)
1056                         if (inode->i_ads_entries[i].stream_id == stream_id)
1057                                 return &inode->i_ads_entries[i].lte;
1058         wimlib_assert(0);
1059         return NULL;
1060 }
1061
1062 /* Calculate the SHA1 message digest of a stream and move it from the list of
1063  * unhashed streams to the stream lookup table, possibly joining it with an
1064  * existing lookup table entry for an identical stream.
1065  *
1066  * @lte:  An unhashed lookup table entry.
1067  * @lookup_table:  Lookup table for the WIM.
1068  * @lte_ret:  On success, write a pointer to the resulting lookup table
1069  *            entry to this location.  This will be the same as @lte
1070  *            if it was inserted into the lookup table, or different if
1071  *            a duplicate stream was found.
1072  *
1073  * Returns 0 on success; nonzero if there is an error reading the stream.
1074  */
1075 int
1076 hash_unhashed_stream(struct wim_lookup_table_entry *lte,
1077                      struct wim_lookup_table *lookup_table,
1078                      struct wim_lookup_table_entry **lte_ret)
1079 {
1080         int ret;
1081         struct wim_lookup_table_entry *duplicate_lte;
1082         struct wim_lookup_table_entry **back_ptr;
1083
1084         wimlib_assert(lte->unhashed);
1085
1086         /* back_ptr must be saved because @back_inode and @back_stream_id are in
1087          * union with the SHA1 message digest and will no longer be valid once
1088          * the SHA1 has been calculated. */
1089         back_ptr = retrieve_lte_pointer(lte);
1090
1091         ret = sha1_resource(lte);
1092         if (ret)
1093                 return ret;
1094
1095         /* Look for a duplicate stream */
1096         duplicate_lte = __lookup_resource(lookup_table, lte->hash);
1097         list_del(&lte->unhashed_list);
1098         if (duplicate_lte) {
1099                 /* We have a duplicate stream.  Transfer the reference counts
1100                  * from this stream to the duplicate, update the reference to
1101                  * this stream (in an inode or ads_entry) to point to the
1102                  * duplicate, then free this stream. */
1103                 wimlib_assert(!(duplicate_lte->unhashed));
1104                 duplicate_lte->refcnt += lte->refcnt;
1105                 duplicate_lte->out_refcnt += lte->refcnt;
1106                 *back_ptr = duplicate_lte;
1107                 free_lookup_table_entry(lte);
1108                 lte = duplicate_lte;
1109         } else {
1110                 /* No duplicate stream, so we need to insert
1111                  * this stream into the lookup table and treat
1112                  * it as a hashed stream. */
1113                 lookup_table_insert(lookup_table, lte);
1114                 lte->unhashed = 0;
1115         }
1116         if (lte_ret)
1117                 *lte_ret = lte;
1118         return 0;
1119 }
1120