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   1 /*
   2  * extract_image.c
   3  *
   4  * Support for extracting WIM files.
   5  */
   6
   7 /*
   8  * Copyright (C) 2012, 2013 Eric Biggers
   9  *
  10  * This file is part of wimlib, a library for working with WIM files.
  11  *
  12  * wimlib is free software; you can redistribute it and/or modify it under the
  13  * terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 3 of the License, or (at your option)
  15  * any later version.
  16  *
  17  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  18  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  19  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  20  * details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <stdlib.h>
  29 #include <sys/stat.h>
  30 #include <errno.h>
  31 #include <unistd.h>
  32
  33 #ifdef __WIN32__
  34 #  include "win32.h"
  35 #endif
  36
  37 #include "wimlib_internal.h"
  38 #include "dentry.h"
  39 #include "lookup_table.h"
  40 #include "xml.h"
  41
  42 #ifdef WITH_NTFS_3G
  43 #  include <ntfs-3g/volume.h>
  44 #endif
  45
  46 static int
  47 do_apply_op(struct wim_dentry *dentry, struct apply_args *args,
  48             int (*apply_dentry_func)(const tchar *, size_t,
  49                                      struct wim_dentry *, struct apply_args *))
  50 {
  51         tchar *p;
  52         const tchar *full_path;
  53         size_t full_path_nchars;
  54
  55         wimlib_assert(dentry->_full_path != NULL);
  56         full_path = dentry->_full_path + 1;
  57         full_path_nchars = dentry->full_path_nbytes / sizeof(tchar) - 1;
  58         tchar output_path[args->target_nchars + 1 +
  59                          (full_path_nchars - args->wim_source_path_nchars) + 1];
  60         p = output_path;
  61
  62         tmemcpy(p, args->target, args->target_nchars);
  63         p += args->target_nchars;
  64
  65         if (dentry != args->extract_root) {
  66                 *p++ = T('/');
  67                 tmemcpy(p, full_path + args->wim_source_path_nchars,
  68                         full_path_nchars - args->wim_source_path_nchars);
  69                 p += full_path_nchars - args->wim_source_path_nchars;
  70         }
  71         *p = T('\0');
  72         return (*apply_dentry_func)(output_path, p - output_path,
  73                                     dentry, args);
  74 }
  75
  76
  77 /* Extracts a file, directory, or symbolic link from the WIM archive. */
  78 static int
  79 apply_dentry_normal(struct wim_dentry *dentry, void *arg)
  80 {
  81 #ifdef __WIN32__
  82         return do_apply_op(dentry, arg, win32_do_apply_dentry);
  83 #else
  84         return do_apply_op(dentry, arg, unix_do_apply_dentry);
  85 #endif
  86 }
  87
  88
  89 /* Apply timestamps to an extracted file or directory */
  90 static int
  91 apply_dentry_timestamps_normal(struct wim_dentry *dentry, void *arg)
  92 {
  93 #ifdef __WIN32__
  94         return do_apply_op(dentry, arg, win32_do_apply_dentry_timestamps);
  95 #else
  96         return do_apply_op(dentry, arg, unix_do_apply_dentry_timestamps);
  97 #endif
  98 }
  99
 100 /* Extract a dentry if it hasn't already been extracted and either
 101  * WIMLIB_EXTRACT_FLAG_NO_STREAMS is not specified, or the dentry is a directory
 102  * and/or has no unnamed stream. */
 103 static int
 104 maybe_apply_dentry(struct wim_dentry *dentry, void *arg)
 105 {
 106         struct apply_args *args = arg;
 107         int ret;
 108
 109         if (!dentry->needs_extraction)
 110                 return 0;
 111
 112         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_NO_STREAMS &&
 113             !dentry_is_directory(dentry) &&
 114             inode_unnamed_lte_resolved(dentry->d_inode) != NULL)
 115                 return 0;
 116
 117         if ((args->extract_flags & WIMLIB_EXTRACT_FLAG_VERBOSE) &&
 118              args->progress_func) {
 119                 args->progress.extract.cur_path = dentry->_full_path;
 120                 args->progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DENTRY,
 121                                     &args->progress);
 122         }
 123         ret = args->apply_dentry(dentry, args);
 124         if (ret == 0)
 125                 dentry->needs_extraction = 0;
 126         return ret;
 127 }
 128
 129 static void
 130 calculate_bytes_to_extract(struct list_head *stream_list,
 131                            int extract_flags,
 132                            union wimlib_progress_info *progress)
 133 {
 134         struct wim_lookup_table_entry *lte;
 135         u64 total_bytes = 0;
 136         u64 num_streams = 0;
 137
 138         /* For each stream to be extracted... */
 139         list_for_each_entry(lte, stream_list, extraction_list) {
 140                 if (extract_flags &
 141                     (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
 142                 {
 143                         /* In the symlink or hard link extraction mode, each
 144                          * stream will be extracted one time regardless of how
 145                          * many dentries share the stream. */
 146                         wimlib_assert(!(extract_flags & WIMLIB_EXTRACT_FLAG_NTFS));
 147                         if (!lte->extracted_file) {
 148                                 num_streams++;
 149                                 total_bytes += wim_resource_size(lte);
 150                         }
 151                 } else {
 152                         num_streams += lte->out_refcnt;
 153                         total_bytes += lte->out_refcnt * wim_resource_size(lte);
 154                 }
 155         }
 156         progress->extract.num_streams = num_streams;
 157         progress->extract.total_bytes = total_bytes;
 158         progress->extract.completed_bytes = 0;
 159 }
 160
 161 static void
 162 maybe_add_stream_for_extraction(struct wim_lookup_table_entry *lte,
 163                                 struct list_head *stream_list)
 164 {
 165         if (++lte->out_refcnt == 1) {
 166                 INIT_LIST_HEAD(&lte->lte_dentry_list);
 167                 list_add_tail(&lte->extraction_list, stream_list);
 168         }
 169 }
 170
 171 struct find_streams_ctx {
 172         struct list_head stream_list;
 173         int extract_flags;
 174 };
 175
 176 static int
 177 dentry_find_streams_to_extract(struct wim_dentry *dentry, void *_ctx)
 178 {
 179         struct find_streams_ctx *ctx = _ctx;
 180         struct wim_inode *inode = dentry->d_inode;
 181         struct wim_lookup_table_entry *lte;
 182         bool dentry_added = false;
 183         struct list_head *stream_list = &ctx->stream_list;
 184         int extract_flags = ctx->extract_flags;
 185
 186         dentry->needs_extraction = 1;
 187
 188         lte = inode_unnamed_lte_resolved(inode);
 189         if (lte) {
 190                 if (!inode->i_visited)
 191                         maybe_add_stream_for_extraction(lte, stream_list);
 192                 list_add_tail(&dentry->tmp_list, &lte->lte_dentry_list);
 193                 dentry_added = true;
 194         }
 195
 196         /* Determine whether to include alternate data stream entries or not.
 197          *
 198          * UNIX:  Include them if extracting using NTFS-3g.
 199          *
 200          * Windows: Include them undconditionally, although if the filesystem is
 201          * not NTFS we won't actually be able to extract them. */
 202 #if defined(WITH_NTFS_3G)
 203         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
 204 #elif defined(__WIN32__)
 205         if (1)
 206 #else
 207         if (0)
 208 #endif
 209         {
 210                 for (unsigned i = 0; i < inode->i_num_ads; i++) {
 211                         if (inode->i_ads_entries[i].stream_name_nbytes != 0) {
 212                                 lte = inode->i_ads_entries[i].lte;
 213                                 if (lte) {
 214                                         if (!inode->i_visited) {
 215                                                 maybe_add_stream_for_extraction(lte,
 216                                                                                 stream_list);
 217                                         }
 218                                         if (!dentry_added) {
 219                                                 list_add_tail(&dentry->tmp_list,
 220                                                               &lte->lte_dentry_list);
 221                                                 dentry_added = true;
 222                                         }
 223                                 }
 224                         }
 225                 }
 226         }
 227         inode->i_visited = 1;
 228         return 0;
 229 }
 230
 231 static int
 232 dentry_resolve_and_zero_lte_refcnt(struct wim_dentry *dentry, void *_lookup_table)
 233 {
 234         struct wim_inode *inode = dentry->d_inode;
 235         struct wim_lookup_table *lookup_table = _lookup_table;
 236         struct wim_lookup_table_entry *lte;
 237
 238         inode_resolve_ltes(inode, lookup_table);
 239         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
 240                 lte = inode_stream_lte_resolved(inode, i);
 241                 if (lte)
 242                         lte->out_refcnt = 0;
 243         }
 244         return 0;
 245 }
 246
 247 static void
 248 find_streams_for_extraction(struct wim_dentry *root,
 249                             struct list_head *stream_list,
 250                             struct wim_lookup_table *lookup_table,
 251                             int extract_flags)
 252 {
 253         struct find_streams_ctx ctx;
 254
 255         INIT_LIST_HEAD(&ctx.stream_list);
 256         ctx.extract_flags = extract_flags;
 257         for_dentry_in_tree(root, dentry_resolve_and_zero_lte_refcnt, lookup_table);
 258         for_dentry_in_tree(root, dentry_find_streams_to_extract, &ctx);
 259         list_transfer(&ctx.stream_list, stream_list);
 260 }
 261
 262 static int
 263 dentry_reset_needs_extraction(struct wim_dentry *dentry, void *_ignore)
 264 {
 265         dentry->needs_extraction = 0;
 266         dentry->d_inode->i_visited = 0;
 267         return 0;
 268 }
 269
 270 struct apply_operations {
 271         int (*apply_dentry)(struct wim_dentry *dentry, void *arg);
 272         int (*apply_dentry_timestamps)(struct wim_dentry *dentry, void *arg);
 273 };
 274
 275 static const struct apply_operations normal_apply_operations = {
 276         .apply_dentry = apply_dentry_normal,
 277         .apply_dentry_timestamps = apply_dentry_timestamps_normal,
 278 };
 279
 280 #ifdef WITH_NTFS_3G
 281 static const struct apply_operations ntfs_apply_operations = {
 282         .apply_dentry = apply_dentry_ntfs,
 283         .apply_dentry_timestamps = apply_dentry_timestamps_ntfs,
 284 };
 285 #endif
 286
 287 static int
 288 apply_stream_list(struct list_head *stream_list,
 289                   struct apply_args *args,
 290                   const struct apply_operations *ops,
 291                   wimlib_progress_func_t progress_func)
 292 {
 293         uint64_t bytes_per_progress = args->progress.extract.total_bytes / 100;
 294         uint64_t next_progress = bytes_per_progress;
 295         struct wim_lookup_table_entry *lte;
 296         struct wim_dentry *dentry;
 297         int ret;
 298
 299         /* This complicated loop is essentially looping through the dentries,
 300          * although dentries may be visited more than once (if a dentry contains
 301          * two different nonempty streams) or not at all (if a dentry contains
 302          * no non-empty streams).
 303          *
 304          * The outer loop is over the distinct streams to be extracted so that
 305          * sequential reading of the WIM can be implemented. */
 306
 307         /* For each distinct stream to be extracted */
 308         list_for_each_entry(lte, stream_list, extraction_list) {
 309                 /* For each dentry to be extracted that is a name for an inode
 310                  * containing the stream */
 311                 list_for_each_entry(dentry, &lte->lte_dentry_list, tmp_list) {
 312                         /* Extract the dentry if it was not already
 313                          * extracted */
 314                         ret = maybe_apply_dentry(dentry, args);
 315                         if (ret)
 316                                 return ret;
 317                         if (progress_func &&
 318                             args->progress.extract.completed_bytes >= next_progress)
 319                         {
 320                                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS,
 321                                               &args->progress);
 322                                 if (args->progress.extract.completed_bytes >=
 323                                     args->progress.extract.total_bytes)
 324                                 {
 325                                         next_progress = ~0ULL;
 326                                 } else {
 327                                         next_progress =
 328                                                 min (args->progress.extract.completed_bytes +
 329                                                      bytes_per_progress,
 330                                                      args->progress.extract.total_bytes);
 331                                 }
 332                         }
 333                 }
 334         }
 335         return 0;
 336 }
 337
 338 static int
 339 sort_stream_list_by_wim_position(struct list_head *stream_list)
 340 {
 341         struct list_head *cur;
 342         size_t num_streams;
 343         struct wim_lookup_table_entry **array;
 344         size_t i;
 345         size_t array_size;
 346
 347         num_streams = 0;
 348         list_for_each(cur, stream_list)
 349                 num_streams++;
 350         array_size = num_streams * sizeof(array[0]);
 351         array = MALLOC(array_size);
 352         if (!array) {
 353                 ERROR("Failed to allocate %zu bytes to sort stream entries",
 354                       array_size);
 355                 return WIMLIB_ERR_NOMEM;
 356         }
 357         cur = stream_list->next;
 358         for (i = 0; i < num_streams; i++) {
 359                 array[i] = container_of(cur, struct wim_lookup_table_entry, extraction_list);
 360                 cur = cur->next;
 361         }
 362
 363         qsort(array, num_streams, sizeof(array[0]), cmp_streams_by_wim_position);
 364
 365         INIT_LIST_HEAD(stream_list);
 366         for (i = 0; i < num_streams; i++)
 367                 list_add_tail(&array[i]->extraction_list, stream_list);
 368         FREE(array);
 369         return 0;
 370 }
 371
 372 /*
 373  * Extract a dentry to standard output.
 374  *
 375  * This obviously doesn't make sense in all cases.  We return an error if the
 376  * dentry does not correspond to a regular file.  Otherwise we extract the
 377  * unnamed data stream only.
 378  */
 379 static int
 380 extract_dentry_to_stdout(struct wim_dentry *dentry)
 381 {
 382         int ret = 0;
 383         if (!dentry_is_regular_file(dentry)) {
 384                 ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
 385                       "extracted to standard output", dentry->_full_path);
 386                 ret = WIMLIB_ERR_NOT_A_REGULAR_FILE;
 387         } else {
 388                 struct wim_lookup_table_entry *lte;
 389
 390                 lte = inode_unnamed_lte_resolved(dentry->d_inode);
 391                 if (lte) {
 392                         ret = extract_wim_resource_to_fd(lte, STDOUT_FILENO,
 393                                                          wim_resource_size(lte));
 394                 }
 395         }
 396         return ret;
 397 }
 398
 399 /*
 400  * extract_tree - Extract a file or directory tree from the currently selected
 401  *                WIM image.
 402  *
 403  * @wim:        WIMStruct for the WIM file, with the desired image selected
 404  *              (as wim->current_image).
 405  * @wim_source_path:
 406  *              "Canonical" (i.e. no leading or trailing slashes, path
 407  *              separators forwald slashes) path inside the WIM image to
 408  *              extract.  An empty string means the full image.
 409  * @target:
 410  *              Filesystem path to extract the file or directory tree to.
 411  *
 412  * @extract_flags:
 413  *              WIMLIB_EXTRACT_FLAG_*.  Also, the private flag
 414  *              WIMLIB_EXTRACT_FLAG_MULTI_IMAGE will be set if this is being
 415  *              called through wimlib_extract_image() with WIMLIB_ALL_IMAGES as
 416  *              the image.
 417  *
 418  * @progress_func:
 419  *              If non-NULL, progress function for the extraction.  The messages
 420  *              we may in this function are:
 421  *
 422  *              WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN or
 423  *                      WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN;
 424  *              WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN;
 425  *              WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END;
 426  *              WIMLIB_PROGRESS_MSG_EXTRACT_DENTRY;
 427  *              WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS;
 428  *              WIMLIB_PROGRESS_MSG_APPLY_TIMESTAMPS;
 429  *              WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END or
 430  *                      WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END.
 431  *
 432  * Returns 0 on success; nonzero on failure.
 433  */
 434 static int
 435 extract_tree(WIMStruct *wim, const tchar *wim_source_path, const tchar *target,
 436              int extract_flags, wimlib_progress_func_t progress_func)
 437 {
 438         int ret;
 439         struct list_head stream_list;
 440         struct apply_args args;
 441         const struct apply_operations *ops;
 442         struct wim_dentry *root;
 443
 444         memset(&args, 0, sizeof(args));
 445
 446         args.w                      = wim;
 447         args.target                 = target;
 448         args.extract_flags          = extract_flags;
 449         args.progress_func          = progress_func;
 450         args.target_nchars          = tstrlen(target);
 451         args.wim_source_path_nchars = tstrlen(wim_source_path);
 452
 453         if (progress_func) {
 454                 args.progress.extract.wimfile_name = wim->filename;
 455                 args.progress.extract.image = wim->current_image;
 456                 args.progress.extract.extract_flags = (extract_flags &
 457                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
 458                 args.progress.extract.image_name = wimlib_get_image_name(wim,
 459                                                                          wim->current_image);
 460                 args.progress.extract.extract_root_wim_source_path = wim_source_path;
 461                 args.progress.extract.target = target;
 462         }
 463
 464 #ifdef WITH_NTFS_3G
 465         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 466                 args.vol = ntfs_mount(target, 0);
 467                 if (!args.vol) {
 468                         ERROR_WITH_ERRNO("Failed to mount NTFS volume `%"TS"'",
 469                                          target);
 470                         ret = WIMLIB_ERR_NTFS_3G;
 471                         goto out;
 472                 }
 473                 ops = &ntfs_apply_operations;
 474         } else
 475 #endif
 476                 ops = &normal_apply_operations;
 477
 478         root = get_dentry(wim, wim_source_path);
 479         if (!root) {
 480                 ERROR("Path \"%"TS"\" does not exist in WIM image %d",
 481                       wim_source_path, wim->current_image);
 482                 ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
 483                 goto out_ntfs_umount;
 484         }
 485         args.extract_root = root;
 486
 487         ret = calculate_dentry_tree_full_paths(root);
 488         if (ret)
 489                 goto out_ntfs_umount;
 490
 491         /* Build a list of the streams that need to be extracted */
 492         find_streams_for_extraction(root,
 493                                     &stream_list,
 494                                     wim->lookup_table, extract_flags);
 495
 496         /* Calculate the number of bytes of data that will be extracted */
 497         calculate_bytes_to_extract(&stream_list, extract_flags,
 498                                    &args.progress);
 499
 500         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
 501                 ret = extract_dentry_to_stdout(root);
 502                 goto out_dentry_reset_needs_extraction;
 503         }
 504
 505         if (progress_func) {
 506                 progress_func(*wim_source_path ? WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN :
 507                               WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN,
 508                               &args.progress);
 509         }
 510
 511         /* If a sequential extraction was specified, sort the streams to be
 512          * extracted by their position in the WIM file, so that the WIM file can
 513          * be read sequentially. */
 514         if (extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL) {
 515                 ret = sort_stream_list_by_wim_position(&stream_list);
 516                 if (ret != 0) {
 517                         WARNING("Falling back to non-sequential extraction");
 518                         extract_flags &= ~WIMLIB_EXTRACT_FLAG_SEQUENTIAL;
 519                 }
 520         }
 521
 522         if (progress_func) {
 523                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN,
 524                               &args.progress);
 525         }
 526
 527         /* Make the directory structure and extract empty files */
 528         args.extract_flags |= WIMLIB_EXTRACT_FLAG_NO_STREAMS;
 529         args.apply_dentry = ops->apply_dentry;
 530         ret = for_dentry_in_tree(root, maybe_apply_dentry, &args);
 531         args.extract_flags &= ~WIMLIB_EXTRACT_FLAG_NO_STREAMS;
 532         if (ret)
 533                 goto out_dentry_reset_needs_extraction;
 534
 535         if (progress_func) {
 536                 progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END,
 537                               &args.progress);
 538         }
 539
 540         if (extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) {
 541                 args.target_realpath = realpath(target, NULL);
 542                 if (!args.target_realpath) {
 543                         ret = WIMLIB_ERR_NOMEM;
 544                         goto out_dentry_reset_needs_extraction;
 545                 }
 546                 args.target_realpath_len = tstrlen(args.target_realpath);
 547         }
 548
 549         /* Extract non-empty files */
 550         ret = apply_stream_list(&stream_list, &args, ops, progress_func);
 551         if (ret)
 552                 goto out_free_target_realpath;
 553
 554         if (progress_func) {
 555                 progress_func(WIMLIB_PROGRESS_MSG_APPLY_TIMESTAMPS,
 556                               &args.progress);
 557         }
 558
 559         /* Apply timestamps */
 560         ret = for_dentry_in_tree_depth(root,
 561                                        ops->apply_dentry_timestamps, &args);
 562         if (ret)
 563                 goto out_free_target_realpath;
 564
 565         if (progress_func) {
 566                 progress_func(*wim_source_path ? WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END :
 567                               WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END,
 568                               &args.progress);
 569         }
 570 out_free_target_realpath:
 571         FREE(args.target_realpath);
 572 out_dentry_reset_needs_extraction:
 573         for_dentry_in_tree(root, dentry_reset_needs_extraction, NULL);
 574 out_ntfs_umount:
 575 #ifdef WITH_NTFS_3G
 576         /* Unmount the NTFS volume */
 577         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 578                 if (ntfs_umount(args.vol, FALSE) != 0) {
 579                         ERROR_WITH_ERRNO("Failed to unmount NTFS volume `%"TS"'",
 580                                          args.target);
 581                         if (ret == 0)
 582                                 ret = WIMLIB_ERR_NTFS_3G;
 583                 }
 584         }
 585 #endif
 586 out:
 587         return ret;
 588 }
 589
 590 /* Validates a single wimlib_extract_command, mostly checking to make sure the
 591  * extract flags make sense. */
 592 static int
 593 check_extract_command(struct wimlib_extract_command *cmd, int wim_header_flags)
 594 {
 595         int extract_flags;
 596         bool is_entire_image = (cmd->wim_source_path[0] == T('\0'));
 597
 598         /* Empty destination path? */
 599         if (cmd->fs_dest_path[0] == T('\0'))
 600                 return WIMLIB_ERR_INVALID_PARAM;
 601
 602         extract_flags = cmd->extract_flags;
 603
 604         /* Specified both symlink and hardlink modes? */
 605         if ((extract_flags &
 606              (WIMLIB_EXTRACT_FLAG_SYMLINK |
 607               WIMLIB_EXTRACT_FLAG_HARDLINK)) == (WIMLIB_EXTRACT_FLAG_SYMLINK |
 608                                                  WIMLIB_EXTRACT_FLAG_HARDLINK))
 609                 return WIMLIB_ERR_INVALID_PARAM;
 610
 611 #ifdef __WIN32__
 612         /* Wanted UNIX data on Windows? */
 613         if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 614                 ERROR("Extracting UNIX data is not supported on Windows");
 615                 return WIMLIB_ERR_INVALID_PARAM;
 616         }
 617         /* Wanted linked extraction on Windows?  (XXX This is possible, just not
 618          * implemented yet.) */
 619         if (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 620                              WIMLIB_EXTRACT_FLAG_HARDLINK))
 621         {
 622                 ERROR("Linked extraction modes are not supported on Windows");
 623                 return WIMLIB_ERR_INVALID_PARAM;
 624         }
 625 #endif
 626
 627         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 628                 /* NTFS-3g extraction mode requested */
 629 #ifdef WITH_NTFS_3G
 630                 if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 631                                       WIMLIB_EXTRACT_FLAG_HARDLINK))) {
 632                         ERROR("Cannot specify symlink or hardlink flags when applying\n"
 633                               "        directly to a NTFS volume");
 634                         return WIMLIB_ERR_INVALID_PARAM;
 635                 }
 636                 if (!is_entire_image &&
 637                     (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS))
 638                 {
 639                         ERROR("When applying directly to a NTFS volume you can "
 640                               "only extract a full image, not part of one");
 641                         return WIMLIB_ERR_INVALID_PARAM;
 642                 }
 643                 if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 644                         ERROR("Cannot restore UNIX-specific data in "
 645                               "the NTFS extraction mode");
 646                         return WIMLIB_ERR_INVALID_PARAM;
 647                 }
 648 #else
 649                 ERROR("wimlib was compiled without support for NTFS-3g, so");
 650                 ERROR("we cannot apply a WIM image directly to a NTFS volume");
 651                 return WIMLIB_ERR_UNSUPPORTED;
 652 #endif
 653         }
 654
 655         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
 656                               WIMLIB_EXTRACT_FLAG_NORPFIX)) ==
 657                 (WIMLIB_EXTRACT_FLAG_RPFIX | WIMLIB_EXTRACT_FLAG_NORPFIX))
 658         {
 659                 ERROR("Cannot specify RPFIX and NORPFIX flags at the same time!");
 660                 return WIMLIB_ERR_INVALID_PARAM;
 661         }
 662
 663         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
 664                               WIMLIB_EXTRACT_FLAG_NORPFIX)) == 0)
 665         {
 666                 /* Do reparse point fixups by default if the WIM header says
 667                  * they are enabled and we are extracting a full image. */
 668                 if ((wim_header_flags & WIM_HDR_FLAG_RP_FIX) && is_entire_image)
 669                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
 670         }
 671
 672         if (!is_entire_image && (extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)) {
 673                 ERROR("Cannot specify --rpfix when not extracting entire image");
 674                 return WIMLIB_ERR_INVALID_PARAM;
 675         }
 676
 677         cmd->extract_flags = extract_flags;
 678         return 0;
 679 }
 680
 681
 682 /* Internal function to execute extraction commands for a WIM image. */
 683 static int
 684 do_wimlib_extract_files(WIMStruct *wim,
 685                         int image,
 686                         struct wimlib_extract_command *cmds,
 687                         size_t num_cmds,
 688                         wimlib_progress_func_t progress_func)
 689 {
 690         int ret;
 691         bool found_link_cmd = false;
 692         bool found_nolink_cmd = false;
 693
 694         /* Select the image from which we are extracting files */
 695         ret = select_wim_image(wim, image);
 696         if (ret)
 697                 return ret;
 698
 699         /* Make sure there are no streams in the WIM that have not been
 700          * checksummed yet. */
 701         ret = wim_checksum_unhashed_streams(wim);
 702         if (ret)
 703                 return ret;
 704
 705         /* Check for problems with the extraction commands */
 706         for (size_t i = 0; i < num_cmds; i++) {
 707                 ret = check_extract_command(&cmds[i], wim->hdr.flags);
 708                 if (ret)
 709                         return ret;
 710                 if (cmds[i].extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 711                                              WIMLIB_EXTRACT_FLAG_HARDLINK)) {
 712                         found_link_cmd = true;
 713                 } else {
 714                         found_nolink_cmd = true;
 715                 }
 716                 if (found_link_cmd && found_nolink_cmd) {
 717                         ERROR("Symlink or hardlink extraction mode must "
 718                               "be set on all extraction commands");
 719                         return WIMLIB_ERR_INVALID_PARAM;
 720                 }
 721         }
 722
 723         /* Execute the extraction commands */
 724         for (size_t i = 0; i < num_cmds; i++) {
 725                 ret = extract_tree(wim,
 726                                    cmds[i].wim_source_path,
 727                                    cmds[i].fs_dest_path,
 728                                    cmds[i].extract_flags,
 729                                    progress_func);
 730                 if (ret)
 731                         return ret;
 732         }
 733         return 0;
 734 }
 735
 736 /* Extract files or directories from a WIM image. */
 737 WIMLIBAPI int
 738 wimlib_extract_files(WIMStruct *wim,
 739                      int image,
 740                      const struct wimlib_extract_command *cmds,
 741                      size_t num_cmds,
 742                      int default_extract_flags,
 743                      WIMStruct **additional_swms,
 744                      unsigned num_additional_swms,
 745                      wimlib_progress_func_t progress_func)
 746 {
 747         int ret;
 748         struct wimlib_extract_command *cmds_copy;
 749         int all_flags = 0;
 750
 751         default_extract_flags &= WIMLIB_EXTRACT_MASK_PUBLIC;
 752
 753         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
 754         if (ret)
 755                 goto out;
 756
 757         if (num_cmds == 0)
 758                 goto out;
 759
 760         if (num_additional_swms)
 761                 merge_lookup_tables(wim, additional_swms, num_additional_swms);
 762
 763         cmds_copy = CALLOC(num_cmds, sizeof(cmds[0]));
 764         if (!cmds_copy) {
 765                 ret = WIMLIB_ERR_NOMEM;
 766                 goto out_restore_lookup_table;
 767         }
 768
 769         for (size_t i = 0; i < num_cmds; i++) {
 770                 cmds_copy[i].extract_flags = (default_extract_flags |
 771                                                  cmds[i].extract_flags)
 772                                                 & WIMLIB_EXTRACT_MASK_PUBLIC;
 773                 all_flags |= cmds_copy[i].extract_flags;
 774
 775                 cmds_copy[i].wim_source_path = canonicalize_wim_path(cmds[i].wim_source_path);
 776                 if (!cmds_copy[i].wim_source_path) {
 777                         ret = WIMLIB_ERR_NOMEM;
 778                         goto out_free_cmds_copy;
 779                 }
 780
 781                 cmds_copy[i].fs_dest_path = canonicalize_fs_path(cmds[i].fs_dest_path);
 782                 if (!cmds_copy[i].fs_dest_path) {
 783                         ret = WIMLIB_ERR_NOMEM;
 784                         goto out_free_cmds_copy;
 785                 }
 786
 787         }
 788         ret = do_wimlib_extract_files(wim, image,
 789                                       cmds_copy, num_cmds,
 790                                       progress_func);
 791
 792         if (all_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 793                          WIMLIB_EXTRACT_FLAG_HARDLINK))
 794         {
 795                 for_lookup_table_entry(wim->lookup_table,
 796                                        lte_free_extracted_file, NULL);
 797         }
 798 out_free_cmds_copy:
 799         for (size_t i = 0; i < num_cmds; i++) {
 800                 FREE(cmds_copy[i].wim_source_path);
 801                 FREE(cmds_copy[i].fs_dest_path);
 802         }
 803         FREE(cmds_copy);
 804 out_restore_lookup_table:
 805         if (num_additional_swms)
 806                 unmerge_lookup_table(wim);
 807 out:
 808         return ret;
 809 }
 810
 811 /*
 812  * Extracts an image from a WIM file.
 813  *
 814  * @wim:                WIMStruct for the WIM file.
 815  *
 816  * @image:              Number of the single image to extract.
 817  *
 818  * @target:             Directory or NTFS volume to extract the image to.
 819  *
 820  * @extract_flags:      Bitwise or of WIMLIB_EXTRACT_FLAG_*.
 821  *
 822  * @progress_func:      If non-NULL, a progress function to be called
 823  *                      periodically.
 824  *
 825  * Returns 0 on success; nonzero on failure.
 826  */
 827 static int
 828 extract_single_image(WIMStruct *wim, int image,
 829                      const tchar *target, int extract_flags,
 830                      wimlib_progress_func_t progress_func)
 831 {
 832         int ret;
 833         tchar *target_copy = canonicalize_fs_path(target);
 834         if (!target_copy)
 835                 return WIMLIB_ERR_NOMEM;
 836         struct wimlib_extract_command cmd = {
 837                 .wim_source_path = T(""),
 838                 .fs_dest_path = target_copy,
 839                 .extract_flags = extract_flags,
 840         };
 841         ret = do_wimlib_extract_files(wim, image, &cmd, 1, progress_func);
 842         FREE(target_copy);
 843         return ret;
 844 }
 845
 846 static const tchar * const filename_forbidden_chars =
 847 T(
 848 #ifdef __WIN32__
 849 "<>:\"/\\|?*"
 850 #else
 851 "/"
 852 #endif
 853 );
 854
 855 /* This function checks if it is okay to use a WIM image's name as a directory
 856  * name.  */
 857 static bool
 858 image_name_ok_as_dir(const tchar *image_name)
 859 {
 860         return image_name && *image_name &&
 861                 !tstrpbrk(image_name, filename_forbidden_chars) &&
 862                 tstrcmp(image_name, T(".")) &&
 863                 tstrcmp(image_name, T(".."));
 864 }
 865
 866 /* Extracts all images from the WIM to the directory @target, with the images
 867  * placed in subdirectories named by their image names. */
 868 static int
 869 extract_all_images(WIMStruct *wim,
 870                    const tchar *target,
 871                    int extract_flags,
 872                    wimlib_progress_func_t progress_func)
 873 {
 874         size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
 875         size_t output_path_len = tstrlen(target);
 876         tchar buf[output_path_len + 1 + image_name_max_len + 1];
 877         int ret;
 878         int image;
 879         const tchar *image_name;
 880         struct stat stbuf;
 881
 882         if (tstat(target, &stbuf)) {
 883                 if (errno == ENOENT)
 884                 {
 885                         if (tmkdir(target, S_IRWXU | S_IRGRP | S_IXGRP |
 886                                            S_IROTH | S_IXOTH))
 887                         {
 888                                 ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
 889                                 return WIMLIB_ERR_MKDIR;
 890                         }
 891                 } else {
 892                         ERROR_WITH_ERRNO("Failed to stat \"%"TS"\"", target);
 893                         return WIMLIB_ERR_STAT;
 894                 }
 895         } else if (!S_ISDIR(stbuf.st_mode)) {
 896                 ERROR("\"%"TS"\" is not a directory", target);
 897                 return WIMLIB_ERR_NOTDIR;
 898         }
 899
 900         tmemcpy(buf, target, output_path_len);
 901         buf[output_path_len] = T('/');
 902         for (image = 1; image <= wim->hdr.image_count; image++) {
 903                 image_name = wimlib_get_image_name(wim, image);
 904                 if (image_name_ok_as_dir(image_name)) {
 905                         tstrcpy(buf + output_path_len + 1, image_name);
 906                 } else {
 907                         /* Image name is empty or contains forbidden characters.
 908                          * Use image number instead. */
 909                         tsprintf(buf + output_path_len + 1, T("%d"), image);
 910                 }
 911                 ret = extract_single_image(wim, image, buf, extract_flags,
 912                                            progress_func);
 913                 if (ret)
 914                         return ret;
 915         }
 916         return 0;
 917 }
 918
 919 /* Extracts a single image or all images from a WIM file to a directory or NTFS
 920  * volume. */
 921 WIMLIBAPI int
 922 wimlib_extract_image(WIMStruct *wim,
 923                      int image,
 924                      const tchar *target,
 925                      int extract_flags,
 926                      WIMStruct **additional_swms,
 927                      unsigned num_additional_swms,
 928                      wimlib_progress_func_t progress_func)
 929 {
 930         int ret;
 931
 932         extract_flags &= WIMLIB_EXTRACT_MASK_PUBLIC;
 933
 934         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
 935         if (ret)
 936                 return ret;
 937
 938         if (num_additional_swms)
 939                 merge_lookup_tables(wim, additional_swms, num_additional_swms);
 940
 941         if (image == WIMLIB_ALL_IMAGES) {
 942                 ret = extract_all_images(wim, target,
 943                                          extract_flags | WIMLIB_EXTRACT_FLAG_MULTI_IMAGE,
 944                                          progress_func);
 945         } else {
 946                 ret = extract_single_image(wim, image, target, extract_flags,
 947                                            progress_func);
 948         }
 949
 950         if (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 951                              WIMLIB_EXTRACT_FLAG_HARDLINK))
 952         {
 953                 for_lookup_table_entry(wim->lookup_table,
 954                                        lte_free_extracted_file,
 955                                        NULL);
 956         }
 957         if (num_additional_swms)
 958                 unmerge_lookup_table(wim);
 959         return ret;
 960 }