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   1 /*
   2  * extract.c
   3  *
   4  * Support for extracting WIM images, or files or directories contained in a WIM
   5  * image.
   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/apply.h"
  32 #include "wimlib/dentry.h"
  33 #include "wimlib/encoding.h"
  34 #include "wimlib/endianness.h"
  35 #include "wimlib/error.h"
  36 #include "wimlib/lookup_table.h"
  37 #include "wimlib/paths.h"
  38 #include "wimlib/resource.h"
  39 #include "wimlib/swm.h"
  40 #ifdef __WIN32__
  41 #  include "wimlib/win32.h" /* for realpath() equivalent */
  42 #endif
  43 #include "wimlib/xml.h"
  44
  45 #include <errno.h>
  46 #include <limits.h>
  47 #ifdef WITH_NTFS_3G
  48 #  include <ntfs-3g/volume.h> /* for ntfs_mount(), ntfs_umount() */
  49 #endif
  50 #include <stdlib.h>
  51 #include <sys/stat.h>
  52 #include <unistd.h>
  53
  54 static int
  55 do_apply_op(struct wim_dentry *dentry, struct apply_args *args,
  56             int (*apply_dentry_func)(const tchar *, size_t,
  57                                      struct wim_dentry *, struct apply_args *))
  58 {
  59         tchar *p;
  60         size_t extraction_path_nchars;
  61         struct wim_dentry *d;
  62         LIST_HEAD(ancestor_list);
  63
  64         extraction_path_nchars = args->target_nchars;
  65
  66         for (d = dentry; d != args->extract_root; d = d->parent) {
  67                 if (d->not_extracted)
  68                         return 0;
  69                 extraction_path_nchars += d->extraction_name_nchars + 1;
  70                 list_add(&d->tmp_list, &ancestor_list);
  71         }
  72
  73         tchar extraction_path[extraction_path_nchars + 1];
  74         p = tmempcpy(extraction_path, args->target, args->target_nchars);
  75
  76         list_for_each_entry(d, &ancestor_list, tmp_list) {
  77                 *p++ = OS_PREFERRED_PATH_SEPARATOR;
  78                 p = tmempcpy(p, d->extraction_name, d->extraction_name_nchars);
  79         }
  80         *p = T('\0');
  81         return (*apply_dentry_func)(extraction_path, extraction_path_nchars,
  82                                     dentry, args);
  83 }
  84
  85
  86 /* Extracts a file, directory, or symbolic link from the WIM archive. */
  87 static int
  88 apply_dentry_normal(struct wim_dentry *dentry, void *arg)
  89 {
  90 #ifdef __WIN32__
  91         return do_apply_op(dentry, arg, win32_do_apply_dentry);
  92 #else
  93         return do_apply_op(dentry, arg, unix_do_apply_dentry);
  94 #endif
  95 }
  96
  97
  98 /* Apply timestamps to an extracted file or directory */
  99 static int
 100 apply_dentry_timestamps_normal(struct wim_dentry *dentry, void *arg)
 101 {
 102 #ifdef __WIN32__
 103         return do_apply_op(dentry, arg, win32_do_apply_dentry_timestamps);
 104 #else
 105         return do_apply_op(dentry, arg, unix_do_apply_dentry_timestamps);
 106 #endif
 107 }
 108
 109 static bool
 110 dentry_is_dot_or_dotdot(const struct wim_dentry *dentry)
 111 {
 112         const utf16lechar *file_name = dentry->file_name;
 113         return file_name != NULL &&
 114                 file_name[0] == cpu_to_le16('.') &&
 115                 (file_name[1] == cpu_to_le16('\0') ||
 116                  (file_name[1] == cpu_to_le16('.') &&
 117                   file_name[2] == cpu_to_le16('\0')));
 118 }
 119
 120 /* Extract a dentry if it hasn't already been extracted and either
 121  * WIMLIB_EXTRACT_FLAG_NO_STREAMS is not specified, or the dentry is a directory
 122  * and/or has no unnamed stream. */
 123 static int
 124 maybe_apply_dentry(struct wim_dentry *dentry, void *arg)
 125 {
 126         struct apply_args *args = arg;
 127         int ret;
 128
 129         if (!dentry->needs_extraction)
 130                 return 0;
 131
 132         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_NO_STREAMS &&
 133             !dentry_is_directory(dentry) &&
 134             inode_unnamed_lte_resolved(dentry->d_inode) != NULL)
 135                 return 0;
 136
 137         if ((args->extract_flags & WIMLIB_EXTRACT_FLAG_VERBOSE) &&
 138              args->progress_func) {
 139                 ret = calculate_dentry_full_path(dentry);
 140                 if (ret)
 141                         return ret;
 142                 args->progress.extract.cur_path = dentry->_full_path;
 143                 args->progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DENTRY,
 144                                     &args->progress);
 145         }
 146         ret = args->apply_dentry(dentry, args);
 147         if (ret == 0)
 148                 dentry->needs_extraction = 0;
 149         return ret;
 150 }
 151
 152 static void
 153 calculate_bytes_to_extract(struct list_head *stream_list,
 154                            int extract_flags,
 155                            union wimlib_progress_info *progress)
 156 {
 157         struct wim_lookup_table_entry *lte;
 158         u64 total_bytes = 0;
 159         u64 num_streams = 0;
 160
 161         /* For each stream to be extracted... */
 162         list_for_each_entry(lte, stream_list, extraction_list) {
 163                 if (extract_flags &
 164                     (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
 165                 {
 166                         /* In the symlink or hard link extraction mode, each
 167                          * stream will be extracted one time regardless of how
 168                          * many dentries share the stream. */
 169                         wimlib_assert(!(extract_flags & WIMLIB_EXTRACT_FLAG_NTFS));
 170                         if (!lte->extracted_file) {
 171                                 num_streams++;
 172                                 total_bytes += wim_resource_size(lte);
 173                         }
 174                 } else {
 175                         num_streams += lte->out_refcnt;
 176                         total_bytes += lte->out_refcnt * wim_resource_size(lte);
 177                 }
 178         }
 179         progress->extract.num_streams = num_streams;
 180         progress->extract.total_bytes = total_bytes;
 181         progress->extract.completed_bytes = 0;
 182 }
 183
 184 static void
 185 maybe_add_stream_for_extraction(struct wim_lookup_table_entry *lte,
 186                                 struct list_head *stream_list)
 187 {
 188         if (++lte->out_refcnt == 1) {
 189                 INIT_LIST_HEAD(&lte->lte_dentry_list);
 190                 list_add_tail(&lte->extraction_list, stream_list);
 191         }
 192 }
 193
 194 struct find_streams_ctx {
 195         struct list_head stream_list;
 196         int extract_flags;
 197 };
 198
 199 static int
 200 dentry_find_streams_to_extract(struct wim_dentry *dentry, void *_ctx)
 201 {
 202         struct find_streams_ctx *ctx = _ctx;
 203         struct wim_inode *inode = dentry->d_inode;
 204         struct wim_lookup_table_entry *lte;
 205         bool dentry_added = false;
 206         struct list_head *stream_list = &ctx->stream_list;
 207         int extract_flags = ctx->extract_flags;
 208
 209         if (!dentry->needs_extraction)
 210                 return 0;
 211
 212         lte = inode_unnamed_lte_resolved(inode);
 213         if (lte) {
 214                 if (!inode->i_visited)
 215                         maybe_add_stream_for_extraction(lte, stream_list);
 216                 list_add_tail(&dentry->extraction_stream_list, &lte->lte_dentry_list);
 217                 dentry_added = true;
 218         }
 219
 220         /* Determine whether to include alternate data stream entries or not.
 221          *
 222          * UNIX:  Include them if extracting using NTFS-3g.
 223          *
 224          * Windows: Include them undconditionally, although if the filesystem is
 225          * not NTFS we won't actually be able to extract them. */
 226 #if defined(WITH_NTFS_3G)
 227         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
 228 #elif defined(__WIN32__)
 229         if (1)
 230 #else
 231         if (0)
 232 #endif
 233         {
 234                 for (unsigned i = 0; i < inode->i_num_ads; i++) {
 235                         if (inode->i_ads_entries[i].stream_name_nbytes != 0) {
 236                                 lte = inode->i_ads_entries[i].lte;
 237                                 if (lte) {
 238                                         if (!inode->i_visited) {
 239                                                 maybe_add_stream_for_extraction(lte,
 240                                                                                 stream_list);
 241                                         }
 242                                         if (!dentry_added) {
 243                                                 list_add_tail(&dentry->extraction_stream_list,
 244                                                               &lte->lte_dentry_list);
 245                                                 dentry_added = true;
 246                                         }
 247                                 }
 248                         }
 249                 }
 250         }
 251         inode->i_visited = 1;
 252         return 0;
 253 }
 254
 255 static int
 256 dentry_resolve_and_zero_lte_refcnt(struct wim_dentry *dentry, void *_lookup_table)
 257 {
 258         struct wim_inode *inode = dentry->d_inode;
 259         struct wim_lookup_table *lookup_table = _lookup_table;
 260         struct wim_lookup_table_entry *lte;
 261
 262         inode_resolve_ltes(inode, lookup_table);
 263         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
 264                 lte = inode_stream_lte_resolved(inode, i);
 265                 if (lte)
 266                         lte->out_refcnt = 0;
 267         }
 268         return 0;
 269 }
 270
 271 static void
 272 find_streams_for_extraction(struct wim_dentry *root,
 273                             struct list_head *stream_list,
 274                             struct wim_lookup_table *lookup_table,
 275                             int extract_flags)
 276 {
 277         struct find_streams_ctx ctx;
 278
 279         INIT_LIST_HEAD(&ctx.stream_list);
 280         ctx.extract_flags = extract_flags;
 281         for_dentry_in_tree(root, dentry_resolve_and_zero_lte_refcnt, lookup_table);
 282         for_dentry_in_tree(root, dentry_find_streams_to_extract, &ctx);
 283         list_transfer(&ctx.stream_list, stream_list);
 284 }
 285
 286 struct apply_operations {
 287         int (*apply_dentry)(struct wim_dentry *dentry, void *arg);
 288         int (*apply_dentry_timestamps)(struct wim_dentry *dentry, void *arg);
 289 };
 290
 291 static const struct apply_operations normal_apply_operations = {
 292         .apply_dentry = apply_dentry_normal,
 293         .apply_dentry_timestamps = apply_dentry_timestamps_normal,
 294 };
 295
 296 #ifdef WITH_NTFS_3G
 297 static const struct apply_operations ntfs_apply_operations = {
 298         .apply_dentry = apply_dentry_ntfs,
 299         .apply_dentry_timestamps = apply_dentry_timestamps_ntfs,
 300 };
 301 #endif
 302
 303 static int
 304 apply_stream_list(struct list_head *stream_list,
 305                   struct apply_args *args,
 306                   const struct apply_operations *ops,
 307                   wimlib_progress_func_t progress_func)
 308 {
 309         uint64_t bytes_per_progress = args->progress.extract.total_bytes / 100;
 310         uint64_t next_progress = bytes_per_progress;
 311         struct wim_lookup_table_entry *lte;
 312         struct wim_dentry *dentry;
 313         int ret;
 314
 315         /* This complicated loop is essentially looping through the dentries,
 316          * although dentries may be visited more than once (if a dentry contains
 317          * two different nonempty streams) or not at all (if a dentry contains
 318          * no non-empty streams).
 319          *
 320          * The outer loop is over the distinct streams to be extracted so that
 321          * sequential reading of the WIM can be implemented. */
 322
 323         /* For each distinct stream to be extracted */
 324         list_for_each_entry(lte, stream_list, extraction_list) {
 325                 /* For each dentry to be extracted that is a name for an inode
 326                  * containing the stream */
 327                 list_for_each_entry(dentry, &lte->lte_dentry_list, extraction_stream_list) {
 328                         /* Extract the dentry if it was not already
 329                          * extracted */
 330                         ret = maybe_apply_dentry(dentry, args);
 331                         if (ret)
 332                                 return ret;
 333                         if (progress_func &&
 334                             args->progress.extract.completed_bytes >= next_progress)
 335                         {
 336                                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS,
 337                                               &args->progress);
 338                                 if (args->progress.extract.completed_bytes >=
 339                                     args->progress.extract.total_bytes)
 340                                 {
 341                                         next_progress = ~0ULL;
 342                                 } else {
 343                                         next_progress =
 344                                                 min (args->progress.extract.completed_bytes +
 345                                                      bytes_per_progress,
 346                                                      args->progress.extract.total_bytes);
 347                                 }
 348                         }
 349                 }
 350         }
 351         return 0;
 352 }
 353
 354 static int
 355 sort_stream_list_by_wim_position(struct list_head *stream_list)
 356 {
 357         struct list_head *cur;
 358         size_t num_streams;
 359         struct wim_lookup_table_entry **array;
 360         size_t i;
 361         size_t array_size;
 362
 363         num_streams = 0;
 364         list_for_each(cur, stream_list)
 365                 num_streams++;
 366         array_size = num_streams * sizeof(array[0]);
 367         array = MALLOC(array_size);
 368         if (!array) {
 369                 ERROR("Failed to allocate %zu bytes to sort stream entries",
 370                       array_size);
 371                 return WIMLIB_ERR_NOMEM;
 372         }
 373         cur = stream_list->next;
 374         for (i = 0; i < num_streams; i++) {
 375                 array[i] = container_of(cur, struct wim_lookup_table_entry, extraction_list);
 376                 cur = cur->next;
 377         }
 378
 379         qsort(array, num_streams, sizeof(array[0]), cmp_streams_by_wim_position);
 380
 381         INIT_LIST_HEAD(stream_list);
 382         for (i = 0; i < num_streams; i++)
 383                 list_add_tail(&array[i]->extraction_list, stream_list);
 384         FREE(array);
 385         return 0;
 386 }
 387
 388 /*
 389  * Extract a dentry to standard output.
 390  *
 391  * This obviously doesn't make sense in all cases.  We return an error if the
 392  * dentry does not correspond to a regular file.  Otherwise we extract the
 393  * unnamed data stream only.
 394  */
 395 static int
 396 extract_dentry_to_stdout(struct wim_dentry *dentry)
 397 {
 398         int ret = 0;
 399         if (!dentry_is_regular_file(dentry)) {
 400                 ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
 401                       "extracted to standard output", dentry->_full_path);
 402                 ret = WIMLIB_ERR_NOT_A_REGULAR_FILE;
 403         } else {
 404                 struct wim_lookup_table_entry *lte;
 405
 406                 lte = inode_unnamed_lte_resolved(dentry->d_inode);
 407                 if (lte) {
 408                         ret = extract_wim_resource_to_fd(lte, STDOUT_FILENO,
 409                                                          wim_resource_size(lte));
 410                 }
 411         }
 412         return ret;
 413 }
 414
 415 #ifdef __WIN32__
 416 static const utf16lechar replacement_char = cpu_to_le16(0xfffd);
 417 #else
 418 static const utf16lechar replacement_char = cpu_to_le16('?');
 419 #endif
 420
 421 static bool
 422 file_name_valid(utf16lechar *name, size_t num_chars, bool fix)
 423 {
 424         size_t i;
 425
 426         if (num_chars == 0)
 427                 return true;
 428         for (i = 0; i < num_chars; i++) {
 429                 switch (name[i]) {
 430         #ifdef __WIN32__
 431                 case cpu_to_le16('\\'):
 432                 case cpu_to_le16(':'):
 433                 case cpu_to_le16('*'):
 434                 case cpu_to_le16('?'):
 435                 case cpu_to_le16('"'):
 436                 case cpu_to_le16('<'):
 437                 case cpu_to_le16('>'):
 438                 case cpu_to_le16('|'):
 439         #endif
 440                 case cpu_to_le16('/'):
 441                 case cpu_to_le16('\0'):
 442                         if (fix)
 443                                 name[i] = replacement_char;
 444                         else
 445                                 return false;
 446                 }
 447         }
 448
 449 #ifdef __WIN32__
 450         if (name[num_chars - 1] == cpu_to_le16(' ') ||
 451             name[num_chars - 1] == cpu_to_le16('.'))
 452         {
 453                 if (fix)
 454                         name[num_chars - 1] = replacement_char;
 455                 else
 456                         return false;
 457         }
 458 #endif
 459         return true;
 460 }
 461
 462 /*
 463  * dentry_calculate_extraction_path-
 464  *
 465  * Calculate the actual filename component at which a WIM dentry will be
 466  * extracted, handling invalid filenames "properly".
 467  *
 468  * dentry->extraction_name usually will be set the same as dentry->file_name (on
 469  * UNIX, converted into the platform's multibyte encoding).  However, if the
 470  * file name contains characters that are not valid on the current platform or
 471  * has some other format that is not valid, leave dentry->extraction_name as
 472  * NULL and clear dentry->needs_extraction to indicate that this dentry should
 473  * not be extracted, unless the appropriate flag
 474  * WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES is set in the extract flags, in
 475  * which case a substitute filename will be created and set instead.
 476  *
 477  * Conflicts with case-insensitive names on Windows are handled similarly; see
 478  * below.
 479  */
 480 static int
 481 dentry_calculate_extraction_path(struct wim_dentry *dentry, void *_args)
 482 {
 483         struct apply_args *args = _args;
 484         int ret;
 485
 486         dentry->needs_extraction = 1;
 487
 488         if (dentry == args->extract_root)
 489                 return 0;
 490
 491         if (dentry_is_dot_or_dotdot(dentry)) {
 492                 /* WIM files shouldn't contain . or .. entries.  But if they are
 493                  * there, don't attempt to extract them. */
 494                 WARNING("Skipping extraction of unexpected . or .. file \"%"TS"\"",
 495                         dentry_full_path(dentry));
 496                 goto skip_dentry;
 497         }
 498
 499 #ifdef __WIN32__
 500         struct wim_dentry *other;
 501         list_for_each_entry(other, &dentry->case_insensitive_conflict_list,
 502                             case_insensitive_conflict_list)
 503         {
 504                 if (other->needs_extraction) {
 505                         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS)
 506                         {
 507                                 WARNING("\"%"TS"\" has the same case-insensitive "
 508                                         "name as \"%"TS"\"; extracting dummy name instead",
 509                                         dentry_full_path(dentry),
 510                                         dentry_full_path(other));
 511                                 goto out_replace;
 512                         } else {
 513                                 WARNING("Not extracting \"%"TS"\": has same case-insensitive "
 514                                         "name as \"%"TS"\"",
 515                                         dentry_full_path(dentry),
 516                                         dentry_full_path(other));
 517                                 goto skip_dentry;
 518                         }
 519                 }
 520         }
 521 #endif
 522
 523         if (file_name_valid(dentry->file_name, dentry->file_name_nbytes / 2, false)) {
 524 #ifdef __WIN32__
 525                 dentry->extraction_name = dentry->file_name;
 526                 dentry->extraction_name_nchars = dentry->file_name_nbytes / 2;
 527                 return 0;
 528 #else
 529                 return utf16le_to_tstr(dentry->file_name,
 530                                        dentry->file_name_nbytes,
 531                                        &dentry->extraction_name,
 532                                        &dentry->extraction_name_nchars);
 533 #endif
 534         } else {
 535                 if (args->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
 536                 {
 537                         WARNING("\"%"TS"\" has an invalid filename "
 538                                 "that is not supported on this platform; "
 539                                 "extracting dummy name instead",
 540                                 dentry_full_path(dentry));
 541                         goto out_replace;
 542                 } else {
 543                         WARNING("Not extracting \"%"TS"\": has an invalid filename "
 544                                 "that is not supported on this platform",
 545                                 dentry_full_path(dentry));
 546                         goto skip_dentry;
 547                 }
 548         }
 549
 550 out_replace:
 551         {
 552                 utf16lechar utf16_name_copy[dentry->file_name_nbytes / 2];
 553
 554                 memcpy(utf16_name_copy, dentry->file_name, dentry->file_name_nbytes);
 555                 file_name_valid(utf16_name_copy, dentry->file_name_nbytes / 2, true);
 556
 557                 tchar *tchar_name;
 558                 size_t tchar_nchars;
 559         #ifdef __WIN32__
 560                 tchar_name = utf16_name_copy;
 561                 tchar_nchars = dentry->file_name_nbytes / 2;
 562         #else
 563                 ret = utf16le_to_tstr(utf16_name_copy,
 564                                       dentry->file_name_nbytes,
 565                                       &tchar_name, &tchar_nchars);
 566                 if (ret)
 567                         return ret;
 568         #endif
 569                 size_t fixed_name_num_chars = tchar_nchars;
 570                 tchar fixed_name[tchar_nchars + 50];
 571
 572                 tmemcpy(fixed_name, tchar_name, tchar_nchars);
 573                 fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
 574                                                  T(" (invalid filename #%lu)"),
 575                                                  ++args->invalid_sequence);
 576         #ifndef __WIN32__
 577                 FREE(tchar_name);
 578         #endif
 579                 dentry->extraction_name = memdup(fixed_name, 2 * fixed_name_num_chars + 2);
 580                 if (!dentry->extraction_name)
 581                         return WIMLIB_ERR_NOMEM;
 582                 dentry->extraction_name_nchars = fixed_name_num_chars;
 583         }
 584         return 0;
 585 skip_dentry:
 586         dentry->needs_extraction = 0;
 587         dentry->not_extracted = 1;
 588         return 0;
 589 }
 590
 591 static int
 592 dentry_reset_needs_extraction(struct wim_dentry *dentry, void *_ignore)
 593 {
 594         dentry->needs_extraction = 0;
 595         dentry->not_extracted = 0;
 596         dentry->is_win32_name = 0;
 597         dentry->d_inode->i_visited = 0;
 598         dentry->d_inode->i_dos_name_extracted = 0;
 599         FREE(dentry->d_inode->i_extracted_file);
 600         dentry->d_inode->i_extracted_file = NULL;
 601         if ((void*)dentry->extraction_name != (void*)dentry->file_name)
 602                 FREE(dentry->extraction_name);
 603         dentry->extraction_name = NULL;
 604         return 0;
 605 }
 606
 607 /*
 608  * extract_tree - Extract a file or directory tree from the currently selected
 609  *                WIM image.
 610  *
 611  * @wim:        WIMStruct for the WIM file, with the desired image selected
 612  *              (as wim->current_image).
 613  * @wim_source_path:
 614  *              "Canonical" (i.e. no leading or trailing slashes, path
 615  *              separators forwald slashes) path inside the WIM image to
 616  *              extract.  An empty string means the full image.
 617  * @target:
 618  *              Filesystem path to extract the file or directory tree to.
 619  *
 620  * @extract_flags:
 621  *              WIMLIB_EXTRACT_FLAG_*.  Also, the private flag
 622  *              WIMLIB_EXTRACT_FLAG_MULTI_IMAGE will be set if this is being
 623  *              called through wimlib_extract_image() with WIMLIB_ALL_IMAGES as
 624  *              the image.
 625  *
 626  * @progress_func:
 627  *              If non-NULL, progress function for the extraction.  The messages
 628  *              we may in this function are:
 629  *
 630  *              WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN or
 631  *                      WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN;
 632  *              WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN;
 633  *              WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END;
 634  *              WIMLIB_PROGRESS_MSG_EXTRACT_DENTRY;
 635  *              WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS;
 636  *              WIMLIB_PROGRESS_MSG_APPLY_TIMESTAMPS;
 637  *              WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END or
 638  *                      WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END.
 639  *
 640  * Returns 0 on success; nonzero on failure.
 641  */
 642 static int
 643 extract_tree(WIMStruct *wim, const tchar *wim_source_path, const tchar *target,
 644              int extract_flags, wimlib_progress_func_t progress_func)
 645 {
 646         int ret;
 647         struct list_head stream_list;
 648         struct apply_args args;
 649         const struct apply_operations *ops;
 650         struct wim_dentry *root;
 651
 652         memset(&args, 0, sizeof(args));
 653
 654         args.w                      = wim;
 655         args.target                 = target;
 656         args.extract_flags          = extract_flags;
 657         args.progress_func          = progress_func;
 658         args.target_nchars          = tstrlen(target);
 659
 660         if (progress_func) {
 661                 args.progress.extract.wimfile_name = wim->filename;
 662                 args.progress.extract.image = wim->current_image;
 663                 args.progress.extract.extract_flags = (extract_flags &
 664                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
 665                 args.progress.extract.image_name = wimlib_get_image_name(wim,
 666                                                                          wim->current_image);
 667                 args.progress.extract.extract_root_wim_source_path = wim_source_path;
 668                 args.progress.extract.target = target;
 669         }
 670
 671 #ifdef WITH_NTFS_3G
 672         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 673                 args.vol = ntfs_mount(target, 0);
 674                 if (!args.vol) {
 675                         ERROR_WITH_ERRNO("Failed to mount NTFS volume `%"TS"'",
 676                                          target);
 677                         ret = WIMLIB_ERR_NTFS_3G;
 678                         goto out;
 679                 }
 680                 ops = &ntfs_apply_operations;
 681         } else
 682 #endif
 683                 ops = &normal_apply_operations;
 684
 685         root = get_dentry(wim, wim_source_path);
 686         if (!root) {
 687                 ERROR("Path \"%"TS"\" does not exist in WIM image %d",
 688                       wim_source_path, wim->current_image);
 689                 ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
 690                 goto out_ntfs_umount;
 691         }
 692         args.extract_root = root;
 693
 694         /* Calculate the actual filename component of each extracted dentry, and
 695          * in the process set the dentry->needs_extraction flag on dentries that
 696          * will be extracted. */
 697         ret = for_dentry_in_tree(root, dentry_calculate_extraction_path, &args);
 698         if (ret)
 699                 goto out_dentry_reset_needs_extraction;
 700
 701         /* Build a list of the streams that need to be extracted */
 702         find_streams_for_extraction(root,
 703                                     &stream_list,
 704                                     wim->lookup_table, extract_flags);
 705
 706         /* Calculate the number of bytes of data that will be extracted */
 707         calculate_bytes_to_extract(&stream_list, extract_flags,
 708                                    &args.progress);
 709
 710         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
 711                 ret = extract_dentry_to_stdout(root);
 712                 goto out_dentry_reset_needs_extraction;
 713         }
 714
 715         if (progress_func) {
 716                 progress_func(*wim_source_path ? WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN :
 717                               WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN,
 718                               &args.progress);
 719         }
 720
 721         /* If a sequential extraction was specified, sort the streams to be
 722          * extracted by their position in the WIM file, so that the WIM file can
 723          * be read sequentially. */
 724         if (extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL) {
 725                 ret = sort_stream_list_by_wim_position(&stream_list);
 726                 if (ret != 0) {
 727                         WARNING("Falling back to non-sequential extraction");
 728                         extract_flags &= ~WIMLIB_EXTRACT_FLAG_SEQUENTIAL;
 729                 }
 730         }
 731
 732         if (progress_func) {
 733                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN,
 734                               &args.progress);
 735         }
 736
 737         /* Make the directory structure and extract empty files */
 738         args.extract_flags |= WIMLIB_EXTRACT_FLAG_NO_STREAMS;
 739         args.apply_dentry = ops->apply_dentry;
 740         ret = for_dentry_in_tree(root, maybe_apply_dentry, &args);
 741         args.extract_flags &= ~WIMLIB_EXTRACT_FLAG_NO_STREAMS;
 742         if (ret)
 743                 goto out_dentry_reset_needs_extraction;
 744
 745         if (progress_func) {
 746                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END,
 747                               &args.progress);
 748         }
 749
 750         if (extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) {
 751                 args.target_realpath = realpath(target, NULL);
 752                 if (!args.target_realpath) {
 753                         ret = WIMLIB_ERR_NOMEM;
 754                         goto out_dentry_reset_needs_extraction;
 755                 }
 756                 args.target_realpath_len = tstrlen(args.target_realpath);
 757         }
 758
 759         /* Extract non-empty files */
 760         ret = apply_stream_list(&stream_list, &args, ops, progress_func);
 761         if (ret)
 762                 goto out_free_target_realpath;
 763
 764         if (progress_func) {
 765                 progress_func(WIMLIB_PROGRESS_MSG_APPLY_TIMESTAMPS,
 766                               &args.progress);
 767         }
 768
 769         /* Apply timestamps */
 770         ret = for_dentry_in_tree_depth(root,
 771                                        ops->apply_dentry_timestamps, &args);
 772         if (ret)
 773                 goto out_free_target_realpath;
 774
 775         if (progress_func) {
 776                 progress_func(*wim_source_path ? WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END :
 777                               WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END,
 778                               &args.progress);
 779         }
 780 out_free_target_realpath:
 781         FREE(args.target_realpath);
 782 out_dentry_reset_needs_extraction:
 783         for_dentry_in_tree(root, dentry_reset_needs_extraction, NULL);
 784 out_ntfs_umount:
 785 #ifdef WITH_NTFS_3G
 786         /* Unmount the NTFS volume */
 787         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 788                 if (ntfs_umount(args.vol, FALSE) != 0) {
 789                         ERROR_WITH_ERRNO("Failed to unmount NTFS volume `%"TS"'",
 790                                          args.target);
 791                         if (ret == 0)
 792                                 ret = WIMLIB_ERR_NTFS_3G;
 793                 }
 794         }
 795 #endif
 796 out:
 797         return ret;
 798 }
 799
 800 /* Validates a single wimlib_extract_command, mostly checking to make sure the
 801  * extract flags make sense. */
 802 static int
 803 check_extract_command(struct wimlib_extract_command *cmd, int wim_header_flags)
 804 {
 805         int extract_flags;
 806         bool is_entire_image = (cmd->wim_source_path[0] == T('\0'));
 807
 808         /* Empty destination path? */
 809         if (cmd->fs_dest_path[0] == T('\0'))
 810                 return WIMLIB_ERR_INVALID_PARAM;
 811
 812         extract_flags = cmd->extract_flags;
 813
 814         /* Specified both symlink and hardlink modes? */
 815         if ((extract_flags &
 816              (WIMLIB_EXTRACT_FLAG_SYMLINK |
 817               WIMLIB_EXTRACT_FLAG_HARDLINK)) == (WIMLIB_EXTRACT_FLAG_SYMLINK |
 818                                                  WIMLIB_EXTRACT_FLAG_HARDLINK))
 819                 return WIMLIB_ERR_INVALID_PARAM;
 820
 821 #ifdef __WIN32__
 822         /* Wanted UNIX data on Windows? */
 823         if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 824                 ERROR("Extracting UNIX data is not supported on Windows");
 825                 return WIMLIB_ERR_INVALID_PARAM;
 826         }
 827         /* Wanted linked extraction on Windows?  (XXX This is possible, just not
 828          * implemented yet.) */
 829         if (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 830                              WIMLIB_EXTRACT_FLAG_HARDLINK))
 831         {
 832                 ERROR("Linked extraction modes are not supported on Windows");
 833                 return WIMLIB_ERR_INVALID_PARAM;
 834         }
 835 #endif
 836
 837         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 838                 /* NTFS-3g extraction mode requested */
 839 #ifdef WITH_NTFS_3G
 840                 if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 841                                       WIMLIB_EXTRACT_FLAG_HARDLINK))) {
 842                         ERROR("Cannot specify symlink or hardlink flags when applying\n"
 843                               "        directly to a NTFS volume");
 844                         return WIMLIB_ERR_INVALID_PARAM;
 845                 }
 846                 if (!is_entire_image &&
 847                     (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS))
 848                 {
 849                         ERROR("When applying directly to a NTFS volume you can "
 850                               "only extract a full image, not part of one");
 851                         return WIMLIB_ERR_INVALID_PARAM;
 852                 }
 853                 if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 854                         ERROR("Cannot restore UNIX-specific data in "
 855                               "the NTFS extraction mode");
 856                         return WIMLIB_ERR_INVALID_PARAM;
 857                 }
 858 #else
 859                 ERROR("wimlib was compiled without support for NTFS-3g, so");
 860                 ERROR("we cannot apply a WIM image directly to a NTFS volume");
 861                 return WIMLIB_ERR_UNSUPPORTED;
 862 #endif
 863         }
 864
 865         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
 866                               WIMLIB_EXTRACT_FLAG_NORPFIX)) ==
 867                 (WIMLIB_EXTRACT_FLAG_RPFIX | WIMLIB_EXTRACT_FLAG_NORPFIX))
 868         {
 869                 ERROR("Cannot specify RPFIX and NORPFIX flags at the same time!");
 870                 return WIMLIB_ERR_INVALID_PARAM;
 871         }
 872
 873         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
 874                               WIMLIB_EXTRACT_FLAG_NORPFIX)) == 0)
 875         {
 876                 /* Do reparse point fixups by default if the WIM header says
 877                  * they are enabled and we are extracting a full image. */
 878                 if ((wim_header_flags & WIM_HDR_FLAG_RP_FIX) && is_entire_image)
 879                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
 880         }
 881
 882         if (!is_entire_image && (extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)) {
 883                 ERROR("Cannot specify --rpfix when not extracting entire image");
 884                 return WIMLIB_ERR_INVALID_PARAM;
 885         }
 886
 887         cmd->extract_flags = extract_flags;
 888         return 0;
 889 }
 890
 891
 892 /* Internal function to execute extraction commands for a WIM image. */
 893 static int
 894 do_wimlib_extract_files(WIMStruct *wim,
 895                         int image,
 896                         struct wimlib_extract_command *cmds,
 897                         size_t num_cmds,
 898                         wimlib_progress_func_t progress_func)
 899 {
 900         int ret;
 901         bool found_link_cmd = false;
 902         bool found_nolink_cmd = false;
 903
 904         /* Select the image from which we are extracting files */
 905         ret = select_wim_image(wim, image);
 906         if (ret)
 907                 return ret;
 908
 909         /* Make sure there are no streams in the WIM that have not been
 910          * checksummed yet. */
 911         ret = wim_checksum_unhashed_streams(wim);
 912         if (ret)
 913                 return ret;
 914
 915         /* Check for problems with the extraction commands */
 916         for (size_t i = 0; i < num_cmds; i++) {
 917                 ret = check_extract_command(&cmds[i], wim->hdr.flags);
 918                 if (ret)
 919                         return ret;
 920                 if (cmds[i].extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 921                                              WIMLIB_EXTRACT_FLAG_HARDLINK)) {
 922                         found_link_cmd = true;
 923                 } else {
 924                         found_nolink_cmd = true;
 925                 }
 926                 if (found_link_cmd && found_nolink_cmd) {
 927                         ERROR("Symlink or hardlink extraction mode must "
 928                               "be set on all extraction commands");
 929                         return WIMLIB_ERR_INVALID_PARAM;
 930                 }
 931         }
 932
 933         /* Execute the extraction commands */
 934         for (size_t i = 0; i < num_cmds; i++) {
 935                 ret = extract_tree(wim,
 936                                    cmds[i].wim_source_path,
 937                                    cmds[i].fs_dest_path,
 938                                    cmds[i].extract_flags,
 939                                    progress_func);
 940                 if (ret)
 941                         return ret;
 942         }
 943         return 0;
 944 }
 945
 946 /* Extract files or directories from a WIM image. */
 947 WIMLIBAPI int
 948 wimlib_extract_files(WIMStruct *wim,
 949                      int image,
 950                      const struct wimlib_extract_command *cmds,
 951                      size_t num_cmds,
 952                      int default_extract_flags,
 953                      WIMStruct **additional_swms,
 954                      unsigned num_additional_swms,
 955                      wimlib_progress_func_t progress_func)
 956 {
 957         int ret;
 958         struct wimlib_extract_command *cmds_copy;
 959         int all_flags = 0;
 960
 961         default_extract_flags &= WIMLIB_EXTRACT_MASK_PUBLIC;
 962
 963         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
 964         if (ret)
 965                 goto out;
 966
 967         if (num_cmds == 0)
 968                 goto out;
 969
 970         if (num_additional_swms)
 971                 merge_lookup_tables(wim, additional_swms, num_additional_swms);
 972
 973         cmds_copy = CALLOC(num_cmds, sizeof(cmds[0]));
 974         if (!cmds_copy) {
 975                 ret = WIMLIB_ERR_NOMEM;
 976                 goto out_restore_lookup_table;
 977         }
 978
 979         for (size_t i = 0; i < num_cmds; i++) {
 980                 cmds_copy[i].extract_flags = (default_extract_flags |
 981                                                  cmds[i].extract_flags)
 982                                                 & WIMLIB_EXTRACT_MASK_PUBLIC;
 983                 all_flags |= cmds_copy[i].extract_flags;
 984
 985                 cmds_copy[i].wim_source_path = canonicalize_wim_path(cmds[i].wim_source_path);
 986                 if (!cmds_copy[i].wim_source_path) {
 987                         ret = WIMLIB_ERR_NOMEM;
 988                         goto out_free_cmds_copy;
 989                 }
 990
 991                 cmds_copy[i].fs_dest_path = canonicalize_fs_path(cmds[i].fs_dest_path);
 992                 if (!cmds_copy[i].fs_dest_path) {
 993                         ret = WIMLIB_ERR_NOMEM;
 994                         goto out_free_cmds_copy;
 995                 }
 996
 997         }
 998         ret = do_wimlib_extract_files(wim, image,
 999                                       cmds_copy, num_cmds,
1000                                       progress_func);
1001
1002         if (all_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
1003                          WIMLIB_EXTRACT_FLAG_HARDLINK))
1004         {
1005                 for_lookup_table_entry(wim->lookup_table,
1006                                        lte_free_extracted_file, NULL);
1007         }
1008 out_free_cmds_copy:
1009         for (size_t i = 0; i < num_cmds; i++) {
1010                 FREE(cmds_copy[i].wim_source_path);
1011                 FREE(cmds_copy[i].fs_dest_path);
1012         }
1013         FREE(cmds_copy);
1014 out_restore_lookup_table:
1015         if (num_additional_swms)
1016                 unmerge_lookup_table(wim);
1017 out:
1018         return ret;
1019 }
1020
1021 /*
1022  * Extracts an image from a WIM file.
1023  *
1024  * @wim:                WIMStruct for the WIM file.
1025  *
1026  * @image:              Number of the single image to extract.
1027  *
1028  * @target:             Directory or NTFS volume to extract the image to.
1029  *
1030  * @extract_flags:      Bitwise or of WIMLIB_EXTRACT_FLAG_*.
1031  *
1032  * @progress_func:      If non-NULL, a progress function to be called
1033  *                      periodically.
1034  *
1035  * Returns 0 on success; nonzero on failure.
1036  */
1037 static int
1038 extract_single_image(WIMStruct *wim, int image,
1039                      const tchar *target, int extract_flags,
1040                      wimlib_progress_func_t progress_func)
1041 {
1042         int ret;
1043         tchar *target_copy = canonicalize_fs_path(target);
1044         if (!target_copy)
1045                 return WIMLIB_ERR_NOMEM;
1046         struct wimlib_extract_command cmd = {
1047                 .wim_source_path = T(""),
1048                 .fs_dest_path = target_copy,
1049                 .extract_flags = extract_flags,
1050         };
1051         ret = do_wimlib_extract_files(wim, image, &cmd, 1, progress_func);
1052         FREE(target_copy);
1053         return ret;
1054 }
1055
1056 static const tchar * const filename_forbidden_chars =
1057 T(
1058 #ifdef __WIN32__
1059 "<>:\"/\\|?*"
1060 #else
1061 "/"
1062 #endif
1063 );
1064
1065 /* This function checks if it is okay to use a WIM image's name as a directory
1066  * name.  */
1067 static bool
1068 image_name_ok_as_dir(const tchar *image_name)
1069 {
1070         return image_name && *image_name &&
1071                 !tstrpbrk(image_name, filename_forbidden_chars) &&
1072                 tstrcmp(image_name, T(".")) &&
1073                 tstrcmp(image_name, T(".."));
1074 }
1075
1076 /* Extracts all images from the WIM to the directory @target, with the images
1077  * placed in subdirectories named by their image names. */
1078 static int
1079 extract_all_images(WIMStruct *wim,
1080                    const tchar *target,
1081                    int extract_flags,
1082                    wimlib_progress_func_t progress_func)
1083 {
1084         size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
1085         size_t output_path_len = tstrlen(target);
1086         tchar buf[output_path_len + 1 + image_name_max_len + 1];
1087         int ret;
1088         int image;
1089         const tchar *image_name;
1090         struct stat stbuf;
1091
1092         if (tstat(target, &stbuf)) {
1093                 if (errno == ENOENT)
1094                 {
1095                         if (tmkdir(target, S_IRWXU | S_IRGRP | S_IXGRP |
1096                                            S_IROTH | S_IXOTH))
1097                         {
1098                                 ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
1099                                 return WIMLIB_ERR_MKDIR;
1100                         }
1101                 } else {
1102                         ERROR_WITH_ERRNO("Failed to stat \"%"TS"\"", target);
1103                         return WIMLIB_ERR_STAT;
1104                 }
1105         } else if (!S_ISDIR(stbuf.st_mode)) {
1106                 ERROR("\"%"TS"\" is not a directory", target);
1107                 return WIMLIB_ERR_NOTDIR;
1108         }
1109
1110         tmemcpy(buf, target, output_path_len);
1111         buf[output_path_len] = T('/');
1112         for (image = 1; image <= wim->hdr.image_count; image++) {
1113                 image_name = wimlib_get_image_name(wim, image);
1114                 if (image_name_ok_as_dir(image_name)) {
1115                         tstrcpy(buf + output_path_len + 1, image_name);
1116                 } else {
1117                         /* Image name is empty or contains forbidden characters.
1118                          * Use image number instead. */
1119                         tsprintf(buf + output_path_len + 1, T("%d"), image);
1120                 }
1121                 ret = extract_single_image(wim, image, buf, extract_flags,
1122                                            progress_func);
1123                 if (ret)
1124                         return ret;
1125         }
1126         return 0;
1127 }
1128
1129 /* Extracts a single image or all images from a WIM file to a directory or NTFS
1130  * volume. */
1131 WIMLIBAPI int
1132 wimlib_extract_image(WIMStruct *wim,
1133                      int image,
1134                      const tchar *target,
1135                      int extract_flags,
1136                      WIMStruct **additional_swms,
1137                      unsigned num_additional_swms,
1138                      wimlib_progress_func_t progress_func)
1139 {
1140         int ret;
1141
1142         extract_flags &= WIMLIB_EXTRACT_MASK_PUBLIC;
1143
1144         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
1145         if (ret)
1146                 return ret;
1147
1148         if (num_additional_swms)
1149                 merge_lookup_tables(wim, additional_swms, num_additional_swms);
1150
1151         if (image == WIMLIB_ALL_IMAGES) {
1152                 ret = extract_all_images(wim, target,
1153                                          extract_flags | WIMLIB_EXTRACT_FLAG_MULTI_IMAGE,
1154                                          progress_func);
1155         } else {
1156                 ret = extract_single_image(wim, image, target, extract_flags,
1157                                            progress_func);
1158         }
1159
1160         if (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
1161                              WIMLIB_EXTRACT_FLAG_HARDLINK))
1162         {
1163                 for_lookup_table_entry(wim->lookup_table,
1164                                        lte_free_extracted_file,
1165                                        NULL);
1166         }
1167         if (num_additional_swms)
1168                 unmerge_lookup_table(wim);
1169         return ret;
1170 }