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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 #include "wimlib_internal.h"
  28 #include "lookup_table.h"
  29 #include "buffer_io.h"
  30 #include <errno.h>
  31
  32 #ifdef WITH_FUSE
  33 #include <unistd.h>
  34 #endif
  35
  36 struct wim_lookup_table *
  37 new_lookup_table(size_t capacity)
  38 {
  39         struct wim_lookup_table *table;
  40         struct hlist_head *array;
  41
  42         table = MALLOC(sizeof(struct wim_lookup_table));
  43         if (table) {
  44                 array = CALLOC(capacity, sizeof(array[0]));
  45                 if (array) {
  46                         table->num_entries = 0;
  47                         table->capacity = capacity;
  48                         table->array = array;
  49                 } else {
  50                         FREE(table);
  51                         table = NULL;
  52                         ERROR("Failed to allocate memory for lookup table with capacity %zu",
  53                               capacity);
  54                 }
  55         }
  56         return table;
  57 }
  58
  59 struct wim_lookup_table_entry *
  60 new_lookup_table_entry()
  61 {
  62         struct wim_lookup_table_entry *lte;
  63
  64         lte = CALLOC(1, sizeof(struct wim_lookup_table_entry));
  65         if (lte) {
  66                 lte->part_number  = 1;
  67                 lte->refcnt       = 1;
  68         } else {
  69                 ERROR("Out of memory (tried to allocate %zu bytes for "
  70                       "lookup table entry)",
  71                       sizeof(struct wim_lookup_table_entry));
  72         }
  73         return lte;
  74 }
  75
  76 struct wim_lookup_table_entry *
  77 clone_lookup_table_entry(const struct wim_lookup_table_entry *old)
  78 {
  79         struct wim_lookup_table_entry *new;
  80
  81         new = MALLOC(sizeof(*new));
  82         if (!new)
  83                 return NULL;
  84
  85         memcpy(new, old, sizeof(*old));
  86         new->extracted_file = NULL;
  87         switch (new->resource_location) {
  88 #ifdef __WIN32__
  89         case RESOURCE_WIN32:
  90 #endif
  91         case RESOURCE_IN_STAGING_FILE:
  92         case RESOURCE_IN_FILE_ON_DISK:
  93                 BUILD_BUG_ON((void*)&old->file_on_disk !=
  94                              (void*)&old->staging_file_name);
  95                 new->staging_file_name = TSTRDUP(old->staging_file_name);
  96                 if (!new->staging_file_name)
  97                         goto out_free;
  98                 break;
  99         case RESOURCE_IN_ATTACHED_BUFFER:
 100                 new->attached_buffer = MALLOC(wim_resource_size(old));
 101                 if (!new->attached_buffer)
 102                         goto out_free;
 103                 memcpy(new->attached_buffer, old->attached_buffer,
 104                        wim_resource_size(old));
 105                 break;
 106 #ifdef WITH_NTFS_3G
 107         case RESOURCE_IN_NTFS_VOLUME:
 108                 if (old->ntfs_loc) {
 109                         struct ntfs_location *loc;
 110                         loc = MALLOC(sizeof(*loc));
 111                         if (!loc)
 112                                 goto out_free;
 113                         memcpy(loc, old->ntfs_loc, sizeof(*loc));
 114                         loc->path = NULL;
 115                         loc->stream_name = NULL;
 116                         new->ntfs_loc = loc;
 117                         loc->path = STRDUP(old->ntfs_loc->path);
 118                         if (!loc->path)
 119                                 goto out_free;
 120                         loc->stream_name = MALLOC((loc->stream_name_nchars + 1) * 2);
 121                         if (!loc->stream_name)
 122                                 goto out_free;
 123                         memcpy(loc->stream_name,
 124                                old->ntfs_loc->stream_name,
 125                                (loc->stream_name_nchars + 1) * 2);
 126                 }
 127                 break;
 128 #endif
 129         default:
 130                 break;
 131         }
 132         return new;
 133 out_free:
 134         free_lookup_table_entry(new);
 135         return NULL;
 136 }
 137
 138 void
 139 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 140 {
 141         if (lte) {
 142                 switch (lte->resource_location) {
 143                 case RESOURCE_IN_STAGING_FILE:
 144                 case RESOURCE_IN_ATTACHED_BUFFER:
 145                 case RESOURCE_IN_FILE_ON_DISK:
 146 #ifdef __WIN32__
 147                 case RESOURCE_WIN32:
 148 #endif
 149                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 150                                      (void*)&lte->staging_file_name);
 151                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 152                                      (void*)&lte->attached_buffer);
 153                         FREE(lte->file_on_disk);
 154                         break;
 155 #ifdef WITH_NTFS_3G
 156                 case RESOURCE_IN_NTFS_VOLUME:
 157                         if (lte->ntfs_loc) {
 158                                 FREE(lte->ntfs_loc->path);
 159                                 FREE(lte->ntfs_loc->stream_name);
 160                                 FREE(lte->ntfs_loc);
 161                         }
 162                         break;
 163 #endif
 164                 default:
 165                         break;
 166                 }
 167                 FREE(lte);
 168         }
 169 }
 170
 171 static int
 172 do_free_lookup_table_entry(struct wim_lookup_table_entry *entry, void *ignore)
 173 {
 174         free_lookup_table_entry(entry);
 175         return 0;
 176 }
 177
 178
 179 void
 180 free_lookup_table(struct wim_lookup_table *table)
 181 {
 182         DEBUG2("Freeing lookup table");
 183         if (table) {
 184                 if (table->array) {
 185                         for_lookup_table_entry(table,
 186                                                do_free_lookup_table_entry,
 187                                                NULL);
 188                         FREE(table->array);
 189                 }
 190                 FREE(table);
 191         }
 192 }
 193
 194 /*
 195  * Inserts an entry into the lookup table.
 196  *
 197  * @table:      A pointer to the lookup table.
 198  * @lte:        A pointer to the entry to insert.
 199  */
 200 void
 201 lookup_table_insert(struct wim_lookup_table *table,
 202                     struct wim_lookup_table_entry *lte)
 203 {
 204         size_t i = lte->hash_short % table->capacity;
 205         hlist_add_head(&lte->hash_list, &table->array[i]);
 206
 207         /* XXX Make the table grow when too many entries have been inserted. */
 208         table->num_entries++;
 209 }
 210
 211 static void
 212 finalize_lte(struct wim_lookup_table_entry *lte)
 213 {
 214         #ifdef WITH_FUSE
 215         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 216                 unlink(lte->staging_file_name);
 217                 list_del(&lte->staging_list);
 218         }
 219         #endif
 220         free_lookup_table_entry(lte);
 221 }
 222
 223 /* Decrements the reference count for the lookup table entry @lte.  If its
 224  * reference count reaches 0, it is unlinked from the lookup table.  If,
 225  * furthermore, the entry has no opened file descriptors associated with it, the
 226  * entry is freed.  */
 227 void
 228 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 229                      struct wim_lookup_table *table)
 230 {
 231         wimlib_assert(lte != NULL);
 232         wimlib_assert(lte->refcnt != 0);
 233         if (--lte->refcnt == 0) {
 234                 lookup_table_unlink(table, lte);
 235         #ifdef WITH_FUSE
 236                 if (lte->num_opened_fds == 0)
 237         #endif
 238                         finalize_lte(lte);
 239         }
 240 }
 241
 242 #ifdef WITH_FUSE
 243 void
 244 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 245 {
 246         if (lte->num_opened_fds != 0)
 247                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 248                         finalize_lte(lte);
 249 }
 250 #endif
 251
 252 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 253  * return nonzero if any call to the function returns nonzero. */
 254 int
 255 for_lookup_table_entry(struct wim_lookup_table *table,
 256                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 257                        void *arg)
 258 {
 259         struct wim_lookup_table_entry *lte;
 260         struct hlist_node *pos, *tmp;
 261         int ret;
 262
 263         for (size_t i = 0; i < table->capacity; i++) {
 264                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 265                                           hash_list)
 266                 {
 267                         wimlib_assert2(!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA));
 268                         ret = visitor(lte, arg);
 269                         if (ret != 0)
 270                                 return ret;
 271                 }
 272         }
 273         return 0;
 274 }
 275
 276
 277 /*
 278  * Reads the lookup table from a WIM file.
 279  *
 280  * Saves lookup table entries for non-metadata streams in a hash table, and
 281  * saves the metadata entry for each image in a special per-image location (the
 282  * image_metadata array).
 283  */
 284 int
 285 read_lookup_table(WIMStruct *w)
 286 {
 287         u64 num_entries;
 288         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 289         int ret;
 290         struct wim_lookup_table *table;
 291         struct wim_lookup_table_entry *cur_entry, *duplicate_entry;
 292
 293         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
 294                 ERROR("Didn't expect a compressed lookup table!");
 295                 ERROR("Ask the author to implement support for this.");
 296                 return WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
 297         }
 298
 299         DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
 300               w->hdr.lookup_table_res_entry.offset,
 301               w->hdr.lookup_table_res_entry.original_size);
 302
 303         if (fseeko(w->fp, w->hdr.lookup_table_res_entry.offset, SEEK_SET) != 0)
 304         {
 305                 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
 306                                  "lookup table",
 307                                  w->hdr.lookup_table_res_entry.offset);
 308                 return WIMLIB_ERR_READ;
 309         }
 310
 311         num_entries = w->hdr.lookup_table_res_entry.original_size /
 312                       WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE;
 313         table = new_lookup_table(num_entries * 2 + 1);
 314         if (!table)
 315                 return WIMLIB_ERR_NOMEM;
 316
 317         w->current_image = 0;
 318         while (num_entries--) {
 319                 const u8 *p;
 320
 321                 if (fread(buf, 1, sizeof(buf), w->fp) != sizeof(buf)) {
 322                         if (feof(w->fp)) {
 323                                 ERROR("Unexpected EOF in WIM lookup table!");
 324                         } else {
 325                                 ERROR_WITH_ERRNO("Error reading WIM lookup "
 326                                                  "table");
 327                         }
 328                         ret = WIMLIB_ERR_READ;
 329                         goto out_free_lookup_table;
 330                 }
 331                 cur_entry = new_lookup_table_entry();
 332                 if (!cur_entry) {
 333                         ret = WIMLIB_ERR_NOMEM;
 334                         goto out_free_lookup_table;
 335                 }
 336
 337                 cur_entry->wim = w;
 338                 cur_entry->resource_location = RESOURCE_IN_WIM;
 339                 p = get_resource_entry(buf, &cur_entry->resource_entry);
 340                 p = get_u16(p, &cur_entry->part_number);
 341                 p = get_u32(p, &cur_entry->refcnt);
 342                 p = get_bytes(p, SHA1_HASH_SIZE, cur_entry->hash);
 343
 344                 if (cur_entry->part_number != w->hdr.part_number) {
 345                         ERROR("A lookup table entry in part %hu of the WIM "
 346                               "points to part %hu",
 347                               w->hdr.part_number, cur_entry->part_number);
 348                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 349                         goto out_free_cur_entry;
 350                 }
 351
 352                 if (is_zero_hash(cur_entry->hash)) {
 353                         ERROR("The WIM lookup table contains an entry with a "
 354                               "SHA1 message digest of all 0's");
 355                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 356                         goto out_free_cur_entry;
 357                 }
 358
 359                 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 360                     && (cur_entry->resource_entry.size !=
 361                         cur_entry->resource_entry.original_size))
 362                 {
 363                 #ifdef ENABLE_ERROR_MESSAGES
 364                         ERROR("Found uncompressed resource with original size "
 365                               "not the same as compressed size");
 366                         ERROR("The lookup table entry for the resource is as follows:");
 367                         print_lookup_table_entry(cur_entry, stderr);
 368                 #endif
 369                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 370                         goto out_free_cur_entry;
 371                 }
 372
 373                 if (cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 374                         /* Lookup table entry for a metadata resource */
 375                         if (cur_entry->refcnt != 1) {
 376                         #ifdef ENABLE_ERROR_MESSAGES
 377                                 ERROR("Found metadata resource with refcnt != 1:");
 378                                 print_lookup_table_entry(cur_entry, stderr);
 379                         #endif
 380                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 381                                 goto out_free_cur_entry;
 382                         }
 383
 384                         if (w->hdr.part_number != 1) {
 385                                 ERROR("Found a metadata resource in a "
 386                                       "non-first part of the split WIM!");
 387                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 388                                 goto out_free_cur_entry;
 389                         }
 390                         if (w->current_image == w->hdr.image_count) {
 391                                 ERROR("The WIM header says there are %u images "
 392                                       "in the WIM, but we found more metadata "
 393                                       "resources than this", w->hdr.image_count);
 394                                 ret = WIMLIB_ERR_IMAGE_COUNT;
 395                                 goto out_free_cur_entry;
 396                         }
 397
 398                         /* Notice very carefully:  We are assigning the metadata
 399                          * resources in the exact order mirrored by their lookup
 400                          * table entries on disk, which is the behavior of
 401                          * Microsoft's software.  In particular, this overrides
 402                          * the actual locations of the metadata resources
 403                          * themselves in the WIM file as well as any information
 404                          * written in the XML data. */
 405                         DEBUG("Found metadata resource for image %u at "
 406                               "offset %"PRIu64".",
 407                               w->current_image + 1,
 408                               cur_entry->resource_entry.offset);
 409                         w->image_metadata[
 410                                 w->current_image++].metadata_lte = cur_entry;
 411                 } else {
 412                         /* Lookup table entry for a stream that is not a
 413                          * metadata resource */
 414                         duplicate_entry = __lookup_resource(table, cur_entry->hash);
 415                         if (duplicate_entry) {
 416                         #ifdef ENABLE_ERROR_MESSAGES
 417                                 ERROR("The WIM lookup table contains two entries with the "
 418                                       "same SHA1 message digest!");
 419                                 ERROR("The first entry is:");
 420                                 print_lookup_table_entry(duplicate_entry, stderr);
 421                                 ERROR("The second entry is:");
 422                                 print_lookup_table_entry(cur_entry, stderr);
 423                         #endif
 424                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 425                                 goto out_free_cur_entry;
 426                         }
 427                         lookup_table_insert(table, cur_entry);
 428                 }
 429         }
 430
 431         if (w->hdr.part_number == 1 &&
 432             w->current_image != w->hdr.image_count)
 433         {
 434                 ERROR("The WIM header says there are %u images "
 435                       "in the WIM, but we only found %d metadata "
 436                       "resources!", w->hdr.image_count, w->current_image);
 437                 ret = WIMLIB_ERR_IMAGE_COUNT;
 438                 goto out_free_lookup_table;
 439         }
 440         DEBUG("Done reading lookup table.");
 441         w->lookup_table = table;
 442         ret = 0;
 443         goto out;
 444 out_free_cur_entry:
 445         FREE(cur_entry);
 446 out_free_lookup_table:
 447         free_lookup_table(table);
 448 out:
 449         w->current_image = 0;
 450         return ret;
 451 }
 452
 453
 454 /*
 455  * Writes a lookup table entry to the output file.
 456  */
 457 int
 458 write_lookup_table_entry(struct wim_lookup_table_entry *lte, void *_out)
 459 {
 460         FILE *out;
 461         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 462         u8 *p;
 463
 464         out = _out;
 465
 466         /* Don't write entries that have not had file resources or metadata
 467          * resources written for them. */
 468         if (lte->out_refcnt == 0)
 469                 return 0;
 470
 471         if (lte->output_resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 472                 DEBUG("Writing metadata entry at %"PRIu64" "
 473                       "(orig size = %"PRIu64")",
 474                       ftello(out), lte->output_resource_entry.original_size);
 475         }
 476
 477         p = put_resource_entry(buf, &lte->output_resource_entry);
 478         p = put_u16(p, lte->part_number);
 479         p = put_u32(p, lte->out_refcnt);
 480         p = put_bytes(p, SHA1_HASH_SIZE, lte->hash);
 481         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 482                 ERROR_WITH_ERRNO("Failed to write lookup table entry");
 483                 return WIMLIB_ERR_WRITE;
 484         }
 485         return 0;
 486 }
 487
 488 /* Writes the WIM lookup table to the output file. */
 489 int
 490 write_lookup_table(WIMStruct *w, int image, struct resource_entry *out_res_entry)
 491 {
 492         FILE *out = w->out_fp;
 493         off_t start_offset, end_offset;
 494         int ret;
 495         int start_image, end_image;
 496
 497         start_offset = ftello(out);
 498         if (start_offset == -1)
 499                 return WIMLIB_ERR_WRITE;
 500
 501         /* Write lookup table entries for metadata resources */
 502         if (image == WIMLIB_ALL_IMAGES) {
 503                 start_image = 1;
 504                 end_image = w->hdr.image_count;
 505         } else {
 506                 start_image = image;
 507                 end_image = image;
 508         }
 509         for (int i = start_image; i <= end_image; i++) {
 510                 struct wim_lookup_table_entry *metadata_lte;
 511
 512                 metadata_lte = w->image_metadata[i - 1].metadata_lte;
 513                 metadata_lte->out_refcnt = 1;
 514                 metadata_lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
 515                 ret = write_lookup_table_entry(metadata_lte, out);
 516                 if (ret)
 517                         return ret;
 518         }
 519
 520         /* Write lookup table entries for other resources */
 521         ret = for_lookup_table_entry(w->lookup_table, write_lookup_table_entry, out);
 522         if (ret)
 523                 return ret;
 524
 525         /* Fill in the resource entry for the lookup table itself */
 526         end_offset = ftello(out);
 527         if (end_offset == -1)
 528                 return WIMLIB_ERR_WRITE;
 529
 530         out_res_entry->offset        = start_offset;
 531         out_res_entry->size          = end_offset - start_offset;
 532         out_res_entry->original_size = end_offset - start_offset;
 533         out_res_entry->flags         = WIM_RESHDR_FLAG_METADATA;
 534         return 0;
 535 }
 536
 537
 538 int
 539 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 540 {
 541         lte->real_refcnt = 0;
 542         return 0;
 543 }
 544
 545 int
 546 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 547 {
 548         lte->out_refcnt = 0;
 549         return 0;
 550 }
 551
 552 int
 553 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *ignore)
 554 {
 555         if (lte->extracted_file != NULL) {
 556                 FREE(lte->extracted_file);
 557                 lte->extracted_file = NULL;
 558         }
 559         return 0;
 560 }
 561
 562 void
 563 print_lookup_table_entry(const struct wim_lookup_table_entry *lte, FILE *out)
 564 {
 565         if (!lte) {
 566                 tputc(T('\n'), out);
 567                 return;
 568         }
 569         tfprintf(out, T("Offset            = %"PRIu64" bytes\n"),
 570                  lte->resource_entry.offset);
 571
 572         tfprintf(out, T("Size              = %"PRIu64" bytes\n"),
 573                  (u64)lte->resource_entry.size);
 574
 575         tfprintf(out, T("Original size     = %"PRIu64" bytes\n"),
 576                  lte->resource_entry.original_size);
 577
 578         tfprintf(out, T("Part Number       = %hu\n"), lte->part_number);
 579         tfprintf(out, T("Reference Count   = %u\n"), lte->refcnt);
 580
 581         tfprintf(out, T("Hash              = 0x"));
 582         print_hash(lte->hash, out);
 583         tputc(T('\n'), out);
 584
 585         tfprintf(out, T("Flags             = "));
 586         u8 flags = lte->resource_entry.flags;
 587         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 588                 tfputs(T("WIM_RESHDR_FLAG_COMPRESSED, "), out);
 589         if (flags & WIM_RESHDR_FLAG_FREE)
 590                 tfputs(T("WIM_RESHDR_FLAG_FREE, "), out);
 591         if (flags & WIM_RESHDR_FLAG_METADATA)
 592                 tfputs(T("WIM_RESHDR_FLAG_METADATA, "), out);
 593         if (flags & WIM_RESHDR_FLAG_SPANNED)
 594                 tfputs(T("WIM_RESHDR_FLAG_SPANNED, "), out);
 595         tputc(T('\n'), out);
 596         switch (lte->resource_location) {
 597         case RESOURCE_IN_WIM:
 598                 if (lte->wim->filename) {
 599                         tfprintf(out, T("WIM file          = `%"TS"'\n"),
 600                                  lte->wim->filename);
 601                 }
 602                 break;
 603 #ifdef __WIN32__
 604         case RESOURCE_WIN32:
 605 #endif
 606         case RESOURCE_IN_FILE_ON_DISK:
 607                 tfprintf(out, T("File on Disk      = `%"TS"'\n"),
 608                          lte->file_on_disk);
 609                 break;
 610         case RESOURCE_IN_STAGING_FILE:
 611                 tfprintf(out, T("Staging File      = `%"TS"'\n"),
 612                                 lte->staging_file_name);
 613                 break;
 614         default:
 615                 break;
 616         }
 617         tputc(T('\n'), out);
 618 }
 619
 620 static int
 621 do_print_lookup_table_entry(struct wim_lookup_table_entry *lte, void *fp)
 622 {
 623         print_lookup_table_entry(lte, (FILE*)fp);
 624         return 0;
 625 }
 626
 627 /*
 628  * Prints the lookup table of a WIM file.
 629  */
 630 WIMLIBAPI void
 631 wimlib_print_lookup_table(WIMStruct *w)
 632 {
 633         for_lookup_table_entry(w->lookup_table,
 634                                do_print_lookup_table_entry,
 635                                stdout);
 636 }
 637
 638 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 639  * lookup table, or NULL if there is none.  */
 640 struct wim_lookup_table_entry *
 641 __lookup_resource(const struct wim_lookup_table *table, const u8 hash[])
 642 {
 643         size_t i;
 644         struct wim_lookup_table_entry *lte;
 645         struct hlist_node *pos;
 646
 647         wimlib_assert(table != NULL);
 648         wimlib_assert(hash != NULL);
 649
 650         i = *(size_t*)hash % table->capacity;
 651         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 652                 if (hashes_equal(hash, lte->hash))
 653                         return lte;
 654         return NULL;
 655 }
 656
 657 #ifdef WITH_FUSE
 658 /*
 659  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 660  * given a path name.
 661  *
 662  * This is only for pre-resolved inodes.
 663  */
 664 int
 665 lookup_resource(WIMStruct *w,
 666                 const tchar *path,
 667                 int lookup_flags,
 668                 struct wim_dentry **dentry_ret,
 669                 struct wim_lookup_table_entry **lte_ret,
 670                 u16 *stream_idx_ret)
 671 {
 672         struct wim_dentry *dentry;
 673         struct wim_lookup_table_entry *lte;
 674         u16 stream_idx;
 675         const tchar *stream_name = NULL;
 676         struct wim_inode *inode;
 677         tchar *p = NULL;
 678
 679         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 680                 stream_name = path_stream_name(path);
 681                 if (stream_name) {
 682                         p = (tchar*)stream_name - 1;
 683                         *p = T('\0');
 684                 }
 685         }
 686
 687         dentry = get_dentry(w, path);
 688         if (p)
 689                 *p = T(':');
 690         if (!dentry)
 691                 return -errno;
 692
 693         inode = dentry->d_inode;
 694
 695         wimlib_assert(inode->i_resolved);
 696
 697         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
 698               && inode_is_directory(inode))
 699                 return -EISDIR;
 700
 701         if (stream_name) {
 702                 struct wim_ads_entry *ads_entry;
 703                 u16 ads_idx;
 704                 ads_entry = inode_get_ads_entry(inode, stream_name,
 705                                                 &ads_idx);
 706                 if (ads_entry) {
 707                         stream_idx = ads_idx + 1;
 708                         lte = ads_entry->lte;
 709                         goto out;
 710                 } else {
 711                         return -ENOENT;
 712                 }
 713         } else {
 714                 lte = inode->i_lte;
 715                 stream_idx = 0;
 716         }
 717 out:
 718         if (dentry_ret)
 719                 *dentry_ret = dentry;
 720         if (lte_ret)
 721                 *lte_ret = lte;
 722         if (stream_idx_ret)
 723                 *stream_idx_ret = stream_idx;
 724         return 0;
 725 }
 726 #endif
 727
 728 /* Resolve an inode's lookup table entries
 729  *
 730  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
 731  * lookup table) with pointers directly to the lookup table entries.  A circular
 732  * linked list of streams sharing the same lookup table entry is created.
 733  *
 734  * This function always succeeds; unresolved lookup table entries are given a
 735  * NULL pointer.
 736  */
 737 void
 738 inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table)
 739 {
 740
 741         if (!inode->i_resolved) {
 742                 struct wim_lookup_table_entry *lte;
 743                 /* Resolve the default file stream */
 744                 lte = __lookup_resource(table, inode->i_hash);
 745                 inode->i_lte = lte;
 746                 inode->i_resolved = 1;
 747
 748                 /* Resolve the alternate data streams */
 749                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 750                         struct wim_ads_entry *cur_entry = &inode->i_ads_entries[i];
 751                         lte = __lookup_resource(table, cur_entry->hash);
 752                         cur_entry->lte = lte;
 753                 }
 754         }
 755 }
 756
 757 void
 758 inode_unresolve_ltes(struct wim_inode *inode)
 759 {
 760         if (inode->i_resolved) {
 761                 if (inode->i_lte)
 762                         copy_hash(inode->i_hash, inode->i_lte->hash);
 763                 else
 764                         zero_out_hash(inode->i_hash);
 765
 766                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 767                         if (inode->i_ads_entries[i].lte)
 768                                 copy_hash(inode->i_ads_entries[i].hash,
 769                                           inode->i_ads_entries[i].lte->hash);
 770                         else
 771                                 zero_out_hash(inode->i_ads_entries[i].hash);
 772                 }
 773                 inode->i_resolved = 0;
 774         }
 775 }
 776
 777 /*
 778  * Returns the lookup table entry for stream @stream_idx of the inode, where
 779  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
 780  * corresponds to an alternate data stream.
 781  *
 782  * This works for both resolved and un-resolved inodes.
 783  */
 784 struct wim_lookup_table_entry *
 785 inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx,
 786                  const struct wim_lookup_table *table)
 787 {
 788         if (inode->i_resolved)
 789                 return inode_stream_lte_resolved(inode, stream_idx);
 790         else
 791                 return inode_stream_lte_unresolved(inode, stream_idx, table);
 792 }
 793
 794
 795 /* Return the lookup table entry for the unnamed data stream of an inode, or
 796  * NULL if there is none.
 797  *
 798  * You'd think this would be easier than it actually is, since the unnamed data
 799  * stream should be the one referenced from the inode itself.  Alas, if there
 800  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
 801  * data stream in one of the alternate data streams instead of inside the WIM
 802  * dentry itself.  So we need to check the alternate data streams too.
 803  *
 804  * Also, note that a dentry may appear to have more than one unnamed stream, but
 805  * if the SHA1 message digest is all 0's then the corresponding stream does not
 806  * really "count" (this is the case for the inode's own file stream when the
 807  * file stream that should be there is actually in one of the alternate stream
 808  * entries.).  This is despite the fact that we may need to extract such a
 809  * missing entry as an empty file or empty named data stream.
 810  */
 811 struct wim_lookup_table_entry *
 812 inode_unnamed_lte(const struct wim_inode *inode,
 813                   const struct wim_lookup_table *table)
 814 {
 815         if (inode->i_resolved)
 816                 return inode_unnamed_lte_resolved(inode);
 817         else
 818                 return inode_unnamed_lte_unresolved(inode, table);
 819 }
 820
 821 static int
 822 lte_add_stream_size(struct wim_lookup_table_entry *lte, void *total_bytes_p)
 823 {
 824         *(u64*)total_bytes_p += lte->resource_entry.size;
 825         return 0;
 826 }
 827
 828 u64
 829 lookup_table_total_stream_size(struct wim_lookup_table *table)
 830 {
 831         u64 total_size = 0;
 832         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
 833         return total_size;
 834 }