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   1 /*
   2  * extract.c
   3  *
   4  * Support for extracting WIM files.
   5  *
   6  * This code does NOT contain any filesystem-specific features.  In particular,
   7  * security information (i.e. file permissions) and alternate data streams are
   8  * ignored, except possibly to read an alternate data stream that contains
   9  * symbolic link data.
  10  */
  11
  12 /*
  13  * Copyright (C) 2010 Carl Thijssen
  14  * Copyright (C) 2012 Eric Biggers
  15  *
  16  * This file is part of wimlib, a library for working with WIM files.
  17  *
  18  * wimlib is free software; you can redistribute it and/or modify it under the
  19  * terms of the GNU General Public License as published by the Free
  20  * Software Foundation; either version 3 of the License, or (at your option)
  21  * any later version.
  22  *
  23  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  24  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  25  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  26  * details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  30  */
  31
  32
  33 #include "config.h"
  34
  35 #include <dirent.h>
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <string.h>
  39 #include <sys/stat.h>
  40 #include <stdlib.h>
  41 #include <sys/time.h>
  42
  43 #ifdef HAVE_UTIME_H
  44 #include <utime.h>
  45 #endif
  46
  47 #include <unistd.h>
  48
  49 #include "dentry.h"
  50 #include "lookup_table.h"
  51 #include "timestamp.h"
  52 #include "wimlib_internal.h"
  53 #include "xml.h"
  54
  55
  56 static int extract_regular_file_linked(const struct dentry *dentry,
  57                                        const char *output_dir,
  58                                        const char *output_path,
  59                                        int extract_flags,
  60                                        struct lookup_table_entry *lte)
  61 {
  62         /* This mode overrides the normal hard-link extraction and
  63          * instead either symlinks or hardlinks *all* identical files in
  64          * the WIM, even if they are in a different image (in the case
  65          * of a multi-image extraction) */
  66         wimlib_assert(lte->extracted_file);
  67
  68         if (extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK) {
  69                 if (link(lte->extracted_file, output_path) != 0) {
  70                         ERROR_WITH_ERRNO("Failed to hard link "
  71                                          "`%s' to `%s'",
  72                                          output_path, lte->extracted_file);
  73                         return WIMLIB_ERR_LINK;
  74                 }
  75         } else {
  76                 int num_path_components;
  77                 int num_output_dir_path_components;
  78                 size_t extracted_file_len;
  79                 char *p;
  80                 const char *p2;
  81                 size_t i;
  82
  83                 wimlib_assert(extract_flags & WIMLIB_EXTRACT_FLAG_SYMLINK);
  84
  85                 num_path_components =
  86                         get_num_path_components(dentry->full_path_utf8) - 1;
  87                 num_output_dir_path_components =
  88                         get_num_path_components(output_dir);
  89
  90                 if (extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
  91                         num_path_components++;
  92                         num_output_dir_path_components--;
  93                 }
  94                 extracted_file_len = strlen(lte->extracted_file);
  95
  96                 char buf[extracted_file_len + 3 * num_path_components + 1];
  97                 p = &buf[0];
  98
  99                 for (i = 0; i < num_path_components; i++) {
 100                         *p++ = '.';
 101                         *p++ = '.';
 102                         *p++ = '/';
 103                 }
 104                 p2 = lte->extracted_file;
 105                 while (*p2 == '/')
 106                         p2++;
 107                 while (num_output_dir_path_components--)
 108                         p2 = path_next_part(p2, NULL);
 109                 strcpy(p, p2);
 110                 if (symlink(buf, output_path) != 0) {
 111                         ERROR_WITH_ERRNO("Failed to symlink `%s' to "
 112                                          "`%s'",
 113                                          buf, lte->extracted_file);
 114                         return WIMLIB_ERR_LINK;
 115                 }
 116
 117         }
 118         return 0;
 119 }
 120
 121 static int extract_regular_file_unlinked(WIMStruct *w,
 122                                          struct dentry *dentry,
 123                                          const char *output_path,
 124                                          int extract_flags,
 125                                          struct lookup_table_entry *lte)
 126 {
 127         /* Normal mode of extraction.  Regular files and hard links are
 128          * extracted in the way that they appear in the WIM. */
 129
 130         int out_fd;
 131         int ret;
 132         struct inode *inode = dentry->d_inode;
 133
 134         if (!((extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE)
 135                 && (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 136                                      WIMLIB_EXTRACT_FLAG_HARDLINK))))
 137         {
 138                 /* If the dentry is one of a hard link set of at least 2
 139                  * dentries and one of the other dentries has already been
 140                  * extracted, make a hard link to the file corresponding to this
 141                  * already-extracted directory.  Otherwise, extract the file,
 142                  * and set the inode->extracted_file field so that other
 143                  * dentries in the hard link group can link to it. */
 144                 if (inode->link_count > 1) {
 145                         if (inode->extracted_file) {
 146                                 DEBUG("Extracting hard link `%s' => `%s'",
 147                                       output_path, inode->extracted_file);
 148                                 if (link(inode->extracted_file, output_path) != 0) {
 149                                         ERROR_WITH_ERRNO("Failed to hard link "
 150                                                          "`%s' to `%s'",
 151                                                          output_path,
 152                                                          inode->extracted_file);
 153                                         return WIMLIB_ERR_LINK;
 154                                 }
 155                                 return 0;
 156                         }
 157                         FREE(inode->extracted_file);
 158                         inode->extracted_file = STRDUP(output_path);
 159                         if (!inode->extracted_file) {
 160                                 ERROR("Failed to allocate memory for filename");
 161                                 return WIMLIB_ERR_NOMEM;
 162                         }
 163                 }
 164         }
 165
 166         /* Extract the contents of the file to @output_path. */
 167
 168         out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 169         if (out_fd == -1) {
 170                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 171                                  output_path);
 172                 return WIMLIB_ERR_OPEN;
 173         }
 174
 175         if (!lte) {
 176                 /* Empty file with no lookup table entry */
 177                 DEBUG("Empty file `%s'.", output_path);
 178                 ret = 0;
 179                 goto out;
 180         }
 181
 182         ret = extract_full_wim_resource_to_fd(lte, out_fd);
 183         if (ret != 0) {
 184                 ERROR("Failed to extract resource to `%s'", output_path);
 185                 goto out;
 186         }
 187
 188 out:
 189         if (close(out_fd) != 0) {
 190                 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
 191                 ret = WIMLIB_ERR_WRITE;
 192         }
 193         return ret;
 194 }
 195
 196 /*
 197  * Extracts a regular file from the WIM archive.
 198  */
 199 static int extract_regular_file(WIMStruct *w,
 200                                 struct dentry *dentry,
 201                                 const char *output_dir,
 202                                 const char *output_path,
 203                                 int extract_flags)
 204 {
 205         struct lookup_table_entry *lte;
 206         const struct inode *inode = dentry->d_inode;
 207
 208         lte = inode_unnamed_lte(inode, w->lookup_table);
 209
 210         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 211                               WIMLIB_EXTRACT_FLAG_HARDLINK)) && lte) {
 212                 if (lte->extracted_file) {
 213                         return extract_regular_file_linked(dentry, output_dir,
 214                                                            output_path,
 215                                                            extract_flags, lte);
 216                 } else {
 217                         lte->extracted_file = STRDUP(output_path);
 218                         if (!lte->extracted_file)
 219                                 return WIMLIB_ERR_NOMEM;
 220                 }
 221         }
 222
 223         return extract_regular_file_unlinked(w, dentry, output_path,
 224                                              extract_flags, lte);
 225
 226 }
 227
 228 static int extract_symlink(const struct dentry *dentry, const char *output_path,
 229                            const WIMStruct *w)
 230 {
 231         char target[4096];
 232         ssize_t ret = inode_readlink(dentry->d_inode, target,
 233                                      sizeof(target), w, 0);
 234         if (ret <= 0) {
 235                 ERROR("Could not read the symbolic link from dentry `%s'",
 236                       dentry->full_path_utf8);
 237                 return WIMLIB_ERR_INVALID_DENTRY;
 238         }
 239         ret = symlink(target, output_path);
 240         if (ret != 0) {
 241                 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 242                                  output_path, target);
 243                 return WIMLIB_ERR_LINK;
 244         }
 245         return 0;
 246 }
 247
 248 /*
 249  * Extracts a directory from the WIM archive.
 250  *
 251  * @dentry:             The directory entry for the directory.
 252  * @output_path:        The path to which the directory is to be extracted to.
 253  * @return:             True on success, false on failure.
 254  */
 255 static int extract_directory(const char *output_path, bool is_root)
 256 {
 257         int ret;
 258         struct stat stbuf;
 259         ret = stat(output_path, &stbuf);
 260         if (ret == 0) {
 261                 if (S_ISDIR(stbuf.st_mode)) {
 262                         /*if (!is_root)*/
 263                                 /*WARNING("`%s' already exists", output_path);*/
 264                         return 0;
 265                 } else {
 266                         ERROR("`%s' is not a directory", output_path);
 267                         return WIMLIB_ERR_MKDIR;
 268                 }
 269         } else {
 270                 if (errno != ENOENT) {
 271                         ERROR_WITH_ERRNO("Failed to stat `%s'", output_path);
 272                         return WIMLIB_ERR_STAT;
 273                 }
 274         }
 275         /* Compute the output path directory to the directory. */
 276         if (mkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP |
 277                                S_IROTH | S_IXOTH) != 0) {
 278                 ERROR_WITH_ERRNO("Cannot create directory `%s'",
 279                                  output_path);
 280                 return WIMLIB_ERR_MKDIR;
 281         }
 282         return 0;
 283 }
 284
 285 struct extract_args {
 286         WIMStruct *w;
 287         int extract_flags;
 288         const char *output_dir;
 289         unsigned num_lutimes_warnings;
 290 };
 291
 292 /*
 293  * Extracts a file, directory, or symbolic link from the WIM archive.  For use
 294  * in for_dentry_in_tree().
 295  */
 296 static int extract_dentry(struct dentry *dentry, void *arg)
 297 {
 298         struct extract_args *args = arg;
 299         WIMStruct *w = args->w;
 300         int extract_flags = args->extract_flags;
 301         size_t len = strlen(args->output_dir);
 302         char output_path[len + dentry->full_path_utf8_len + 1];
 303
 304         if (dentry_is_directory(dentry)) {
 305                 if (extract_flags & WIMLIB_EXTRACT_FLAG_SKIP_DIRS)
 306                         return 0;
 307         } else {
 308                 if (extract_flags & WIMLIB_EXTRACT_FLAG_DIRS_ONLY)
 309                         return 0;
 310         }
 311
 312         if ((extract_flags & WIMLIB_EXTRACT_FLAG_EMPTY_ONLY)
 313             && (!dentry_is_regular_file(dentry) ||
 314                  inode_unnamed_lte(dentry->d_inode, w->lookup_table) != NULL))
 315                 return 0;
 316
 317         if (extract_flags & WIMLIB_EXTRACT_FLAG_VERBOSE) {
 318                 wimlib_assert(dentry->full_path_utf8);
 319                 puts(dentry->full_path_utf8);
 320         }
 321
 322         memcpy(output_path, args->output_dir, len);
 323         memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
 324         output_path[len + dentry->full_path_utf8_len] = '\0';
 325
 326
 327         if (dentry_is_symlink(dentry))
 328                 return extract_symlink(dentry, output_path, w);
 329         else if (dentry_is_directory(dentry))
 330                 return extract_directory(output_path, dentry_is_root(dentry));
 331         else
 332                 return extract_regular_file(w, dentry, args->output_dir,
 333                                             output_path, extract_flags);
 334 }
 335
 336 /* Apply timestamp to extracted file */
 337 static int apply_dentry_timestamps(struct dentry *dentry, void *arg)
 338 {
 339         struct extract_args *args = arg;
 340         size_t len = strlen(args->output_dir);
 341         char output_path[len + dentry->full_path_utf8_len + 1];
 342         const struct inode *inode = dentry->d_inode;
 343         int ret;
 344
 345         memcpy(output_path, args->output_dir, len);
 346         memcpy(output_path + len, dentry->full_path_utf8, dentry->full_path_utf8_len);
 347         output_path[len + dentry->full_path_utf8_len] = '\0';
 348
 349         struct timeval tv[2];
 350         wim_timestamp_to_timeval(inode->last_access_time, &tv[0]);
 351         wim_timestamp_to_timeval(inode->last_write_time, &tv[1]);
 352         #ifdef HAVE_LUTIMES
 353         ret = lutimes(output_path, tv);
 354         #else
 355         ret = -1;
 356         errno = ENOSYS;
 357         #endif
 358         if (ret != 0) {
 359                 #ifdef HAVE_UTIME
 360                 if (errno == ENOSYS) {
 361                         struct utimbuf buf;
 362                         buf.actime = wim_timestamp_to_unix(inode->last_access_time);
 363                         buf.modtime = wim_timestamp_to_unix(inode->last_write_time);
 364                         if (utime(output_path, &buf) == 0)
 365                                 return 0;
 366                 }
 367                 #endif
 368                 if (errno != ENOSYS || args->num_lutimes_warnings < 10) {
 369                         /*WARNING("Failed to set timestamp on file `%s': %s",*/
 370                                 /*output_path, strerror(errno));*/
 371                         args->num_lutimes_warnings++;
 372                 }
 373         }
 374         return 0;
 375 }
 376
 377
 378 static int dentry_add_streams_for_extraction(struct dentry *dentry,
 379                                              void *wim)
 380 {
 381         WIMStruct *w = wim;
 382         struct list_head *stream_list;
 383         struct lookup_table_entry *lte;
 384
 385         lte = inode_unnamed_lte(dentry->d_inode, w->lookup_table);
 386         if (lte) {
 387                 if (++lte->out_refcnt == 1) {
 388                         INIT_LIST_HEAD(&lte->dentry_list);
 389                         stream_list = w->private;
 390                         list_add_tail(&lte->staging_list, stream_list);
 391                 }
 392                 list_add_tail(&dentry->tmp_list, &lte->dentry_list);
 393         }
 394         return 0;
 395 }
 396
 397 static int cmp_streams_by_wim_position(const void *p1, const void *p2)
 398 {
 399         const struct lookup_table_entry *lte1, *lte2;
 400         lte1 = *(const struct lookup_table_entry**)p1;
 401         lte2 = *(const struct lookup_table_entry**)p2;
 402         if (lte1->resource_entry.offset < lte2->resource_entry.offset)
 403                 return -1;
 404         else if (lte1->resource_entry.offset > lte2->resource_entry.offset)
 405                 return 1;
 406         else
 407                 return 0;
 408 }
 409
 410 static int sort_stream_list_by_wim_position(struct list_head *stream_list)
 411 {
 412         struct list_head *cur;
 413         size_t num_streams;
 414         struct lookup_table_entry **array;
 415         size_t i;
 416         size_t array_size;
 417
 418         DEBUG("Sorting stream list by wim position");
 419
 420         num_streams = 0;
 421         list_for_each(cur, stream_list)
 422                 num_streams++;
 423         array_size = num_streams * sizeof(array[0]);
 424
 425         DEBUG("num_streams = %zu", num_streams);
 426
 427         array = MALLOC(array_size);
 428         if (!array) {
 429                 ERROR("Failed to allocate %zu bytes to sort stream entries",
 430                       array_size);
 431                 return WIMLIB_ERR_NOMEM;
 432         }
 433         cur = stream_list->next;
 434         for (i = 0; i < num_streams; i++) {
 435                 array[i] = container_of(cur, struct lookup_table_entry, staging_list);
 436                 cur = cur->next;
 437         }
 438
 439         qsort(array, num_streams, sizeof(array[0]), cmp_streams_by_wim_position);
 440
 441         INIT_LIST_HEAD(stream_list);
 442         for (i = 0; i < num_streams; i++)
 443                 list_add(&array[i]->staging_list, stream_list);
 444         FREE(array);
 445         return 0;
 446 }
 447
 448 static int extract_single_image(WIMStruct *w, int image,
 449                                 const char *output_dir, int extract_flags)
 450 {
 451         int ret;
 452         struct dentry *root;
 453
 454         DEBUG("Extracting image %d", image);
 455
 456         ret = select_wim_image(w, image);
 457         if (ret != 0)
 458                 return ret;
 459
 460         root = wim_root_dentry(w);
 461
 462         struct extract_args args = {
 463                 .w                    = w,
 464                 .extract_flags        = extract_flags,
 465                 .output_dir           = output_dir,
 466                 .num_lutimes_warnings = 0,
 467         };
 468
 469         if (extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL)
 470                 args.extract_flags |= WIMLIB_EXTRACT_FLAG_DIRS_ONLY;
 471
 472         ret = for_dentry_in_tree(root, extract_dentry, &args);
 473         if (ret != 0)
 474                 return ret;
 475
 476         if (extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL) {
 477                 struct list_head stream_list;
 478                 INIT_LIST_HEAD(&stream_list);
 479                 w->private = &stream_list;
 480                 for_dentry_in_tree(root, dentry_add_streams_for_extraction, w);
 481                 ret = sort_stream_list_by_wim_position(&stream_list);
 482                 args.extract_flags &= ~WIMLIB_EXTRACT_FLAG_DIRS_ONLY;
 483                 if (ret == 0) {
 484                         args.extract_flags |= WIMLIB_EXTRACT_FLAG_SKIP_DIRS;
 485                         struct lookup_table_entry *lte;
 486                         struct lookup_table_entry *tmp;
 487                         struct dentry *dentry;
 488                         list_for_each_entry_safe(lte, tmp, &stream_list, staging_list) {
 489                                 list_del(&lte->staging_list);
 490                                 lte->extracted_file = NULL;
 491                                 list_for_each_entry(dentry, &lte->dentry_list, tmp_list) {
 492                                         ret = extract_dentry(dentry, &args);
 493                                         if (ret != 0)
 494                                                 return ret;
 495                                 }
 496                                 FREE(lte->extracted_file);
 497                         }
 498                         args.extract_flags |= WIMLIB_EXTRACT_FLAG_EMPTY_ONLY;
 499                         ret = for_dentry_in_tree(root, extract_dentry, &args);
 500                         if (ret != 0)
 501                                 return ret;
 502                         args.extract_flags &= ~(WIMLIB_EXTRACT_FLAG_SKIP_DIRS |
 503                                                 WIMLIB_EXTRACT_FLAG_EMPTY_ONLY);
 504                 } else {
 505                         WARNING("Falling back to non-sequential image extraction");
 506                         ret = for_dentry_in_tree(root, extract_dentry, &args);
 507                         if (ret != 0)
 508                                 return ret;
 509                 }
 510         }
 511
 512         return for_dentry_in_tree_depth(root, apply_dentry_timestamps, &args);
 513
 514 }
 515
 516
 517 /* Extracts all images from the WIM to @output_dir, with the images placed in
 518  * subdirectories named by their image names. */
 519 static int extract_all_images(WIMStruct *w, const char *output_dir,
 520                               int extract_flags)
 521 {
 522         size_t image_name_max_len = max(xml_get_max_image_name_len(w), 20);
 523         size_t output_path_len = strlen(output_dir);
 524         char buf[output_path_len + 1 + image_name_max_len + 1];
 525         int ret;
 526         int image;
 527         const char *image_name;
 528
 529         DEBUG("Attempting to extract all images from `%s' to `%s'",
 530               w->filename, output_dir);
 531
 532         ret = extract_directory(output_dir, true);
 533         if (ret != 0)
 534                 return ret;
 535
 536         memcpy(buf, output_dir, output_path_len);
 537         buf[output_path_len] = '/';
 538         for (image = 1; image <= w->hdr.image_count; image++) {
 539
 540                 image_name = wimlib_get_image_name(w, image);
 541                 if (*image_name) {
 542                         strcpy(buf + output_path_len + 1, image_name);
 543                 } else {
 544                         /* Image name is empty. Use image number instead */
 545                         sprintf(buf + output_path_len + 1, "%d", image);
 546                 }
 547                 ret = extract_single_image(w, image, buf, extract_flags);
 548                 if (ret != 0)
 549                         return ret;
 550         }
 551         return 0;
 552 }
 553
 554 /* Extracts a single image or all images from a WIM file. */
 555 WIMLIBAPI int wimlib_extract_image(WIMStruct *w, int image,
 556                                    const char *output_dir,
 557                                    int extract_flags,
 558                                    WIMStruct **additional_swms,
 559                                    unsigned num_additional_swms)
 560 {
 561         struct lookup_table *joined_tab, *w_tab_save;
 562         int ret;
 563
 564         DEBUG("w->filename = %s, image = %d, output_dir = %s, flags = 0x%x, "
 565               "num_additional_swms = %u",
 566               w->filename, image, output_dir, extract_flags, num_additional_swms);
 567
 568         if (!w || !output_dir)
 569                 return WIMLIB_ERR_INVALID_PARAM;
 570
 571         extract_flags &= WIMLIB_EXTRACT_MASK_PUBLIC;
 572
 573         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
 574                         == (WIMLIB_EXTRACT_FLAG_SYMLINK | WIMLIB_EXTRACT_FLAG_HARDLINK))
 575                 return WIMLIB_ERR_INVALID_PARAM;
 576
 577         ret = verify_swm_set(w, additional_swms, num_additional_swms);
 578         if (ret != 0)
 579                 return ret;
 580
 581         if (num_additional_swms) {
 582                 ret = new_joined_lookup_table(w, additional_swms,
 583                                               num_additional_swms, &joined_tab);
 584                 if (ret != 0)
 585                         return ret;
 586                 w_tab_save = w->lookup_table;
 587                 w->lookup_table = joined_tab;
 588         }
 589
 590         for_lookup_table_entry(w->lookup_table, lte_zero_out_refcnt, NULL);
 591
 592         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL)) {
 593                 for_lookup_table_entry(w->lookup_table,
 594                                        lte_zero_extracted_file,
 595                                        NULL);
 596         }
 597
 598         if (image == WIM_ALL_IMAGES) {
 599                 extract_flags |= WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
 600                 ret = extract_all_images(w, output_dir, extract_flags);
 601         } else {
 602                 extract_flags &= ~WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;
 603                 ret = extract_single_image(w, image, output_dir, extract_flags);
 604         }
 605         if (num_additional_swms) {
 606                 free_lookup_table(w->lookup_table);
 607                 w->lookup_table = w_tab_save;
 608         }
 609         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_SEQUENTIAL)) {
 610                 for_lookup_table_entry(w->lookup_table,
 611                                        lte_free_extracted_file,
 612                                        NULL);
 613         }
 614         return ret;
 615
 616 }