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