wimlib.net Git - wimlib/blob - src/extract.c

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