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

   1 /*
   2  * wim.c - Stuff that doesn't fit into any other file
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013 Eric Biggers
   7  *
   8  * This file is part of wimlib, a library for working with WIM files.
   9  *
  10  * wimlib is free software; you can redistribute it and/or modify it under the
  11  * terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 3 of the License, or (at your option)
  13  * any later version.
  14  *
  15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include "config.h"
  26 #endif
  27
  28 #include "wimlib/error.h"
  29 #include "wimlib/dentry.h"
  30 #include "wimlib/encoding.h"
  31 #include "wimlib/file_io.h"
  32 #include "wimlib/integrity.h"
  33 #include "wimlib/lookup_table.h"
  34 #include "wimlib/metadata.h"
  35 #ifdef WITH_NTFS_3G
  36 #  include "wimlib/ntfs_3g.h" /* for do_ntfs_umount() */
  37 #endif
  38 #include "wimlib/security.h"
  39 #include "wimlib/wim.h"
  40 #include "wimlib/xml.h"
  41
  42 #ifdef __WIN32__
  43 #  include "wimlib/win32.h" /* for realpath() replacement */
  44 #endif
  45
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #ifndef __WIN32__
  49 #  include <langinfo.h>
  50 #endif
  51 #include <limits.h>
  52 #include <stdarg.h>
  53 #include <stdlib.h>
  54 #include <unistd.h>
  55
  56 static int
  57 image_print_metadata(WIMStruct *wim)
  58 {
  59         DEBUG("Printing metadata for image %d", wim->current_image);
  60         print_wim_security_data(wim_security_data(wim));
  61         return for_dentry_in_tree(wim_root_dentry(wim), print_dentry,
  62                                   wim->lookup_table);
  63 }
  64
  65
  66 static WIMStruct *
  67 new_wim_struct(void)
  68 {
  69         WIMStruct *wim = CALLOC(1, sizeof(WIMStruct));
  70         if (wim) {
  71                 wim->in_fd.fd = -1;
  72                 wim->out_fd.fd = -1;
  73                 INIT_LIST_HEAD(&wim->subwims);
  74         }
  75         return wim;
  76 }
  77
  78 /* Determine if the chunk size is valid for the specified compression type.  */
  79 static bool
  80 wim_chunk_size_valid(u32 chunk_size, int ctype)
  81 {
  82         u32 order;
  83
  84         /* Chunk size is meaningless for uncompressed WIMs --- any value is
  85          * okay.  */
  86         if (ctype == WIMLIB_COMPRESSION_TYPE_NONE)
  87                 return true;
  88
  89         /* Chunk size must be power of 2.  */
  90         if (chunk_size == 0)
  91                 return false;
  92         order = bsr32(chunk_size);
  93         if (chunk_size != 1U << order)
  94                 return false;
  95
  96         /* Order        Size
  97          * =====        ====
  98          * 15           32768
  99          * 16           65536
 100          * 17           131072
 101          * 18           262144
 102          * 19           524288
 103          * 20           1048576
 104          * 21           2097152
 105          * 22           4194304
 106          * 23           8388608
 107          * 24           16777216
 108          * 25           33554432
 109          * 26           67108864
 110          */
 111         switch (ctype) {
 112         case WIMLIB_COMPRESSION_TYPE_LZX:
 113                 /* For LZX compression, the chunk size corresponds to the LZX
 114                  * window size, which according the LZX specification can be any
 115                  * power of 2 between 2^15 and 2^21, inclusively.  All these are
 116                  * supported by wimlib; however, unfortunately only 2^15 is
 117                  * supported by WIMGAPI[1] so this value is used by default.
 118                  *
 119                  * [1] WIMGAPI (Windows 7) attempts to decompress LZX chunk
 120                  * sizes > 2^15 but seems to have bug(s) that cause it to fail
 121                  * or crash.  (I tried several tweaks to the LZX data but none
 122                  * resulted in successful decompression.)  WIMGAPI (Windows 8)
 123                  * appears to refuse to open WIMs with chunk size > 2^15
 124                  * entirely.  */
 125                 return order >= 15 && order <= 21;
 126
 127         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 128                 /* WIMGAPI (Windows 7) didn't seem to support XPRESS chunk size
 129                  * below 32768 bytes, but larger power-of-two sizes appear to be
 130                  * supported.  67108864 was the largest size that worked.
 131                  * (Note, however, that the offsets of XPRESS matches are still
 132                  * limited to 65535 bytes even when a much larger chunk size is
 133                  * used!)
 134                  *
 135                  * WIMGAPI (Windows 8) seemed to have removed the support for
 136                  * larger XPRESS chunk sizes and will refuse to open such WIMs.
 137                  *
 138                  * 2^15 = 32768 is the default value used for compatibility, but
 139                  * wimlib can actually use up to 2^26.  */
 140                 return order >= 15 && order <= 26;
 141
 142         case WIMLIB_COMPRESSION_TYPE_LZMS:
 143                 return order >= 15 && order <= 26;
 144         }
 145         return false;
 146 }
 147
 148 /* Return the default chunk size to use for the specified compression type.
 149  *
 150  * See notes above in wim_chunk_size_valid().  */
 151 static u32
 152 wim_default_chunk_size(int ctype)
 153 {
 154         switch (ctype) {
 155         case WIMLIB_COMPRESSION_TYPE_LZMS:
 156                 return 131072;
 157         default:
 158                 return 32768;
 159         }
 160 }
 161
 162 /*
 163  * Calls a function on images in the WIM.  If @image is WIMLIB_ALL_IMAGES, @visitor
 164  * is called on the WIM once for each image, with each image selected as the
 165  * current image in turn.  If @image is a certain image, @visitor is called on
 166  * the WIM only once, with that image selected.
 167  */
 168 int
 169 for_image(WIMStruct *wim, int image, int (*visitor)(WIMStruct *))
 170 {
 171         int ret;
 172         int start;
 173         int end;
 174         int i;
 175
 176         if (image == WIMLIB_ALL_IMAGES) {
 177                 start = 1;
 178                 end = wim->hdr.image_count;
 179         } else if (image >= 1 && image <= wim->hdr.image_count) {
 180                 start = image;
 181                 end = image;
 182         } else {
 183                 return WIMLIB_ERR_INVALID_IMAGE;
 184         }
 185         for (i = start; i <= end; i++) {
 186                 ret = select_wim_image(wim, i);
 187                 if (ret != 0)
 188                         return ret;
 189                 ret = visitor(wim);
 190                 if (ret != 0)
 191                         return ret;
 192         }
 193         return 0;
 194 }
 195
 196 /* API function documented in wimlib.h  */
 197 WIMLIBAPI int
 198 wimlib_create_new_wim(int ctype, WIMStruct **wim_ret)
 199 {
 200         WIMStruct *wim;
 201         struct wim_lookup_table *table;
 202         int ret;
 203
 204         wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
 205
 206         DEBUG("Creating new WIM with %"TS" compression.",
 207               wimlib_get_compression_type_string(ctype));
 208
 209         /* Allocate the WIMStruct. */
 210         wim = new_wim_struct();
 211         if (wim == NULL)
 212                 return WIMLIB_ERR_NOMEM;
 213
 214         ret = init_wim_header(&wim->hdr, ctype, wim_default_chunk_size(ctype));
 215         if (ret)
 216                 goto out_free;
 217
 218         table = new_lookup_table(9001);
 219         if (table == NULL) {
 220                 ret = WIMLIB_ERR_NOMEM;
 221                 goto out_free;
 222         }
 223         wim->lookup_table = table;
 224         wim->refcnts_ok = 1;
 225         wim->compression_type = ctype;
 226         wim->out_compression_type = ctype;
 227         wim->chunk_size = wim->hdr.chunk_size;
 228         wim->out_chunk_size = wim->hdr.chunk_size;
 229         *wim_ret = wim;
 230         return 0;
 231 out_free:
 232         FREE(wim);
 233         return ret;
 234 }
 235
 236 int
 237 select_wim_image(WIMStruct *wim, int image)
 238 {
 239         struct wim_image_metadata *imd;
 240         int ret;
 241
 242         DEBUG("Selecting image %d", image);
 243
 244         if (image == WIMLIB_NO_IMAGE) {
 245                 ERROR("Invalid image: %d", WIMLIB_NO_IMAGE);
 246                 return WIMLIB_ERR_INVALID_IMAGE;
 247         }
 248
 249         if (image == wim->current_image)
 250                 return 0;
 251
 252         if (image < 1 || image > wim->hdr.image_count) {
 253                 ERROR("Cannot select image %d: There are only %u images",
 254                       image, wim->hdr.image_count);
 255                 return WIMLIB_ERR_INVALID_IMAGE;
 256         }
 257
 258         if (!wim_has_metadata(wim)) {
 259                 ERROR("\"%"TS"\" does not contain metadata resources!", wim->filename);
 260                 if (wim->hdr.part_number != 1)
 261                         ERROR("Specify the first part of the split WIM instead.");
 262                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 263         }
 264
 265         /* If a valid image is currently selected, it can be freed if it is not
 266          * modified.  */
 267         if (wim->current_image != WIMLIB_NO_IMAGE) {
 268                 imd = wim_get_current_image_metadata(wim);
 269                 if (!imd->modified) {
 270                         wimlib_assert(list_empty(&imd->unhashed_streams));
 271                         DEBUG("Freeing image %u", wim->current_image);
 272                         destroy_image_metadata(imd, NULL, false);
 273                 }
 274         }
 275         wim->current_image = image;
 276         imd = wim_get_current_image_metadata(wim);
 277         if (imd->root_dentry || imd->modified) {
 278                 ret = 0;
 279         } else {
 280                 #ifdef ENABLE_DEBUG
 281                 DEBUG("Reading metadata resource specified by the following "
 282                       "lookup table entry:");
 283                 print_lookup_table_entry(imd->metadata_lte, stderr);
 284                 #endif
 285                 ret = read_metadata_resource(wim, imd);
 286                 if (ret)
 287                         wim->current_image = WIMLIB_NO_IMAGE;
 288         }
 289         return ret;
 290 }
 291
 292
 293 /* API function documented in wimlib.h  */
 294 WIMLIBAPI const tchar *
 295 wimlib_get_compression_type_string(int ctype)
 296 {
 297         switch (ctype) {
 298                 case WIMLIB_COMPRESSION_TYPE_NONE:
 299                         return T("None");
 300                 case WIMLIB_COMPRESSION_TYPE_LZX:
 301                         return T("LZX");
 302                 case WIMLIB_COMPRESSION_TYPE_XPRESS:
 303                         return T("XPRESS");
 304                 case WIMLIB_COMPRESSION_TYPE_LZMS:
 305                         return T("LZMS");
 306                 default:
 307                         return T("Invalid");
 308         }
 309 }
 310
 311 /* API function documented in wimlib.h  */
 312 WIMLIBAPI int
 313 wimlib_resolve_image(WIMStruct *wim, const tchar *image_name_or_num)
 314 {
 315         tchar *p;
 316         long image;
 317         int i;
 318
 319         if (!image_name_or_num || !*image_name_or_num)
 320                 return WIMLIB_NO_IMAGE;
 321
 322         if (!tstrcasecmp(image_name_or_num, T("all"))
 323             || !tstrcasecmp(image_name_or_num, T("*")))
 324                 return WIMLIB_ALL_IMAGES;
 325         image = tstrtol(image_name_or_num, &p, 10);
 326         if (p != image_name_or_num && *p == T('\0') && image > 0) {
 327                 if (image > wim->hdr.image_count)
 328                         return WIMLIB_NO_IMAGE;
 329                 return image;
 330         } else {
 331                 for (i = 1; i <= wim->hdr.image_count; i++) {
 332                         if (!tstrcmp(image_name_or_num,
 333                                      wimlib_get_image_name(wim, i)))
 334                                 return i;
 335                 }
 336                 return WIMLIB_NO_IMAGE;
 337         }
 338 }
 339
 340 /* API function documented in wimlib.h  */
 341 WIMLIBAPI void
 342 wimlib_print_available_images(const WIMStruct *wim, int image)
 343 {
 344         int first;
 345         int last;
 346         int i;
 347         int n;
 348         if (image == WIMLIB_ALL_IMAGES) {
 349                 n = tprintf(T("Available Images:\n"));
 350                 first = 1;
 351                 last = wim->hdr.image_count;
 352         } else if (image >= 1 && image <= wim->hdr.image_count) {
 353                 n = tprintf(T("Information for Image %d\n"), image);
 354                 first = image;
 355                 last = image;
 356         } else {
 357                 tprintf(T("wimlib_print_available_images(): Invalid image %d"),
 358                         image);
 359                 return;
 360         }
 361         for (i = 0; i < n - 1; i++)
 362                 tputchar(T('-'));
 363         tputchar(T('\n'));
 364         for (i = first; i <= last; i++)
 365                 print_image_info(wim->wim_info, i);
 366 }
 367
 368
 369 /* API function documented in wimlib.h  */
 370 WIMLIBAPI int
 371 wimlib_print_metadata(WIMStruct *wim, int image)
 372 {
 373         return for_image(wim, image, image_print_metadata);
 374 }
 375
 376 /* API function documented in wimlib.h  */
 377 WIMLIBAPI int
 378 wimlib_get_wim_info(WIMStruct *wim, struct wimlib_wim_info *info)
 379 {
 380         memset(info, 0, sizeof(struct wimlib_wim_info));
 381         memcpy(info->guid, wim->hdr.guid, WIMLIB_GUID_LEN);
 382         info->image_count = wim->hdr.image_count;
 383         info->boot_index = wim->hdr.boot_idx;
 384         info->wim_version = wim->hdr.wim_version;
 385         info->chunk_size = wim->hdr.chunk_size;
 386         info->part_number = wim->hdr.part_number;
 387         info->total_parts = wim->hdr.total_parts;
 388         info->compression_type = wim->compression_type;
 389         info->total_bytes = wim_info_get_total_bytes(wim->wim_info);
 390         info->has_integrity_table = wim_has_integrity_table(wim);
 391         info->opened_from_file = (wim->filename != NULL);
 392         info->is_readonly = (wim->hdr.flags & WIM_HDR_FLAG_READONLY) ||
 393                              (wim->hdr.total_parts != 1) ||
 394                              (wim->filename && taccess(wim->filename, W_OK));
 395         info->has_rpfix = (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX) != 0;
 396         info->is_marked_readonly = (wim->hdr.flags & WIM_HDR_FLAG_READONLY) != 0;
 397         info->write_in_progress = (wim->hdr.flags & WIM_HDR_FLAG_WRITE_IN_PROGRESS) != 0;
 398         info->metadata_only = (wim->hdr.flags & WIM_HDR_FLAG_METADATA_ONLY) != 0;
 399         info->resource_only = (wim->hdr.flags & WIM_HDR_FLAG_RESOURCE_ONLY) != 0;
 400         info->spanned = (wim->hdr.flags & WIM_HDR_FLAG_SPANNED) != 0;
 401         info->pipable = wim_is_pipable(wim);
 402         return 0;
 403 }
 404
 405 /* API function documented in wimlib.h  */
 406 WIMLIBAPI int
 407 wimlib_set_wim_info(WIMStruct *wim, const struct wimlib_wim_info *info, int which)
 408 {
 409         int ret;
 410
 411         if (which & WIMLIB_CHANGE_READONLY_FLAG) {
 412                 if (info->is_marked_readonly)
 413                         wim->hdr.flags |= WIM_HDR_FLAG_READONLY;
 414                 else
 415                         wim->hdr.flags &= ~WIM_HDR_FLAG_READONLY;
 416         }
 417
 418         if ((which & ~WIMLIB_CHANGE_READONLY_FLAG) == 0)
 419                 return 0;
 420
 421         ret = can_modify_wim(wim);
 422         if (ret)
 423                 return ret;
 424
 425         if (which & WIMLIB_CHANGE_GUID) {
 426                 memcpy(wim->hdr.guid, info->guid, WIM_GID_LEN);
 427                 wim->guid_set_explicitly = 1;
 428         }
 429
 430         if (which & WIMLIB_CHANGE_BOOT_INDEX) {
 431                 if (info->boot_index > wim->hdr.image_count) {
 432                         ERROR("%u is not 0 or a valid image in the WIM to mark as bootable",
 433                               info->boot_index);
 434                         return WIMLIB_ERR_INVALID_IMAGE;
 435                 }
 436                 wim->hdr.boot_idx = info->boot_index;
 437         }
 438
 439         if (which & WIMLIB_CHANGE_RPFIX_FLAG) {
 440                 if (info->has_rpfix)
 441                         wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 442                 else
 443                         wim->hdr.flags &= ~WIM_HDR_FLAG_RP_FIX;
 444         }
 445         return 0;
 446 }
 447
 448 /* API function documented in wimlib.h  */
 449 WIMLIBAPI int
 450 wimlib_set_output_compression_type(WIMStruct *wim, int ctype)
 451 {
 452         switch (ctype) {
 453         case WIMLIB_COMPRESSION_TYPE_INVALID:
 454                 break;
 455         case WIMLIB_COMPRESSION_TYPE_NONE:
 456         case WIMLIB_COMPRESSION_TYPE_LZX:
 457         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 458         case WIMLIB_COMPRESSION_TYPE_LZMS:
 459                 wim->out_compression_type = ctype;
 460
 461                 /* Reset the chunk size if it's no longer valid.  */
 462                 if (!wim_chunk_size_valid(wim->out_chunk_size,
 463                                           wim->out_compression_type))
 464                         wim->out_chunk_size = wim_default_chunk_size(wim->out_compression_type);
 465                 return 0;
 466         }
 467         return WIMLIB_ERR_INVALID_PARAM;
 468 }
 469
 470 /* API function documented in wimlib.h  */
 471 WIMLIBAPI int
 472 wimlib_set_output_chunk_size(WIMStruct *wim, uint32_t chunk_size)
 473 {
 474         if (!wim_chunk_size_valid(chunk_size, wim->out_compression_type)) {
 475                 ERROR("Invalid chunk size (%"PRIu32" bytes) "
 476                       "for compression type %"TS"!",
 477                       chunk_size,
 478                       wimlib_get_compression_type_string(wim->out_compression_type));
 479                 switch (wim->out_compression_type) {
 480                 case WIMLIB_COMPRESSION_TYPE_XPRESS:
 481                         ERROR("Valid chunk sizes for XPRESS are "
 482                               "32768, 65536, 131072, ..., 67108864.");
 483                         break;
 484                 case WIMLIB_COMPRESSION_TYPE_LZX:
 485                         ERROR("Valid chunk sizes for LZX are "
 486                               "32768, 65536, 131072, ..., 2097152.");
 487                         break;
 488                 case WIMLIB_COMPRESSION_TYPE_LZMS:
 489                         ERROR("Valid chunk sizes for LZMS are "
 490                               "32768, 65536, 131072, ..., 67108864.");
 491                         break;
 492                 }
 493                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 494         }
 495         if (chunk_size != 32768 &&
 496             wim->out_compression_type != WIMLIB_COMPRESSION_TYPE_LZMS)
 497         {
 498                 WARNING  ("Changing the compression chunk size to any value other than\n"
 499                 "          the default of 32768 bytes eliminates compatibility with\n"
 500                 "          Microsoft's software!");
 501         }
 502         wim->out_chunk_size = chunk_size;
 503         return 0;
 504 }
 505
 506 static int
 507 do_open_wim(const tchar *filename, struct filedes *fd_ret)
 508 {
 509         int raw_fd;
 510
 511         raw_fd = topen(filename, O_RDONLY | O_BINARY);
 512         if (raw_fd < 0) {
 513                 ERROR_WITH_ERRNO("Can't open \"%"TS"\" read-only", filename);
 514                 return WIMLIB_ERR_OPEN;
 515         }
 516         filedes_init(fd_ret, raw_fd);
 517         return 0;
 518 }
 519
 520 int
 521 reopen_wim(WIMStruct *wim)
 522 {
 523         wimlib_assert(!filedes_valid(&wim->in_fd));
 524         return do_open_wim(wim->filename, &wim->in_fd);
 525 }
 526
 527 int
 528 close_wim(WIMStruct *wim)
 529 {
 530         if (filedes_valid(&wim->in_fd)) {
 531                 filedes_close(&wim->in_fd);
 532                 filedes_invalidate(&wim->in_fd);
 533         }
 534         return 0;
 535 }
 536
 537 /*
 538  * Begins the reading of a WIM file; opens the file and reads its header and
 539  * lookup table, and optionally checks the integrity.
 540  */
 541 static int
 542 begin_read(WIMStruct *wim, const void *wim_filename_or_fd,
 543            int open_flags, wimlib_progress_func_t progress_func)
 544 {
 545         int ret;
 546         int xml_num_images;
 547         const tchar *wimfile;
 548
 549         if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE) {
 550                 wimfile = NULL;
 551                 filedes_init(&wim->in_fd, *(const int*)wim_filename_or_fd);
 552                 wim->in_fd.is_pipe = 1;
 553         } else {
 554                 wimfile = wim_filename_or_fd;
 555                 ret = do_open_wim(wimfile, &wim->in_fd);
 556                 if (ret)
 557                         return ret;
 558
 559                 /* The absolute path to the WIM is requested so that
 560                  * wimlib_overwrite() still works even if the process changes
 561                  * its working directory.  This actually happens if a WIM is
 562                  * mounted read-write, since the FUSE thread changes directory
 563                  * to "/", and it needs to be able to find the WIM file again.
 564                  *
 565                  * This will break if the full path to the WIM changes in the
 566                  * intervening time...
 567                  *
 568                  * Warning: in Windows native builds, realpath() calls the
 569                  * replacement function in win32_replacements.c.
 570                  */
 571                 wim->filename = realpath(wimfile, NULL);
 572                 if (wim->filename == NULL) {
 573                         ERROR_WITH_ERRNO("Failed to resolve WIM filename");
 574                         if (errno == ENOMEM)
 575                                 return WIMLIB_ERR_NOMEM;
 576                         else
 577                                 return WIMLIB_ERR_OPEN;
 578                 }
 579         }
 580
 581         ret = read_wim_header(wim, &wim->hdr);
 582         if (ret)
 583                 return ret;
 584
 585         if (wim->hdr.flags & WIM_HDR_FLAG_WRITE_IN_PROGRESS) {
 586                 WARNING("The WIM_HDR_FLAG_WRITE_IN_PROGRESS flag is set in the header of\n"
 587                         "          \"%"TS"\".  It may be being changed by another process,\n"
 588                         "          or a process may have crashed while writing the WIM.",
 589                         wimfile);
 590         }
 591
 592         if (open_flags & WIMLIB_OPEN_FLAG_WRITE_ACCESS) {
 593                 ret = can_modify_wim(wim);
 594                 if (ret)
 595                         return ret;
 596         }
 597
 598         if ((open_flags & WIMLIB_OPEN_FLAG_ERROR_IF_SPLIT) &&
 599             (wim->hdr.total_parts != 1))
 600                 return WIMLIB_ERR_IS_SPLIT_WIM;
 601
 602         DEBUG("According to header, WIM contains %u images", wim->hdr.image_count);
 603
 604         /* If the boot index is invalid, print a warning and set it to 0 */
 605         if (wim->hdr.boot_idx > wim->hdr.image_count) {
 606                 WARNING("In `%"TS"', image %u is marked as bootable, "
 607                         "but there are only %u images in the WIM",
 608                         wimfile, wim->hdr.boot_idx, wim->hdr.image_count);
 609                 wim->hdr.boot_idx = 0;
 610         }
 611
 612         /* Check and cache the compression type */
 613         if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESSION) {
 614                 if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_LZX) {
 615                         wim->compression_type = WIMLIB_COMPRESSION_TYPE_LZX;
 616                 } else if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_XPRESS) {
 617                         wim->compression_type = WIMLIB_COMPRESSION_TYPE_XPRESS;
 618                 } else if (wim->hdr.flags & WIM_HDR_FLAG_COMPRESS_LZMS) {
 619                         wim->compression_type = WIMLIB_COMPRESSION_TYPE_LZMS;
 620                 } else {
 621                         ERROR("The compression flag is set on \"%"TS"\", but "
 622                               "a flag for a recognized format is not",
 623                               wimfile);
 624                         return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 625                 }
 626         } else {
 627                 wim->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
 628         }
 629         wim->out_compression_type = wim->compression_type;
 630
 631         /* Check and cache the chunk size.  */
 632         wim->chunk_size = wim->out_chunk_size = wim->hdr.chunk_size;
 633         if (!wim_chunk_size_valid(wim->chunk_size, wim->compression_type)) {
 634                 ERROR("Invalid chunk size (%"PRIu32" bytes) "
 635                       "for compression type %"TS"!",
 636                       wim->chunk_size,
 637                       wimlib_get_compression_type_string(wim->compression_type));
 638                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 639         }
 640
 641         if (open_flags & WIMLIB_OPEN_FLAG_CHECK_INTEGRITY) {
 642                 ret = check_wim_integrity(wim, progress_func);
 643                 if (ret == WIM_INTEGRITY_NONEXISTENT) {
 644                         WARNING("No integrity information for `%"TS"'; skipping "
 645                                 "integrity check.", wimfile);
 646                 } else if (ret == WIM_INTEGRITY_NOT_OK) {
 647                         ERROR("WIM is not intact! (Failed integrity check)");
 648                         return WIMLIB_ERR_INTEGRITY;
 649                 } else if (ret != WIM_INTEGRITY_OK) {
 650                         return ret;
 651                 }
 652         }
 653
 654         if (wim->hdr.image_count != 0 && wim->hdr.part_number == 1) {
 655                 wim->image_metadata = new_image_metadata_array(wim->hdr.image_count);
 656                 if (wim->image_metadata == NULL)
 657                         return WIMLIB_ERR_NOMEM;
 658         }
 659
 660         if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE) {
 661                 wim->lookup_table = new_lookup_table(9001);
 662                 if (wim->lookup_table == NULL)
 663                         return WIMLIB_ERR_NOMEM;
 664         } else {
 665                 ret = read_wim_lookup_table(wim);
 666                 if (ret)
 667                         return ret;
 668
 669                 ret = read_wim_xml_data(wim);
 670                 if (ret)
 671                         return ret;
 672
 673                 xml_num_images = wim_info_get_num_images(wim->wim_info);
 674                 if (xml_num_images != wim->hdr.image_count) {
 675                         ERROR("In the file `%"TS"', there are %u <IMAGE> elements "
 676                               "in the XML data,", wimfile, xml_num_images);
 677                         ERROR("but %u images in the WIM!  There must be exactly one "
 678                               "<IMAGE> element per image.", wim->hdr.image_count);
 679                         return WIMLIB_ERR_IMAGE_COUNT;
 680                 }
 681                 DEBUG("Done beginning read of WIM file `%"TS"'.", wimfile);
 682         }
 683         return 0;
 684 }
 685
 686 int
 687 open_wim_as_WIMStruct(const void *wim_filename_or_fd, int open_flags,
 688                       WIMStruct **wim_ret, wimlib_progress_func_t progress_func)
 689 {
 690         WIMStruct *wim;
 691         int ret;
 692
 693         if (open_flags & WIMLIB_OPEN_FLAG_FROM_PIPE)
 694                 DEBUG("Opening pipable WIM from file descriptor %d.", *(const int*)wim_filename_or_fd);
 695         else
 696                 DEBUG("Opening WIM file \"%"TS"\"", (const tchar*)wim_filename_or_fd);
 697
 698         wimlib_global_init(WIMLIB_INIT_FLAG_ASSUME_UTF8);
 699
 700         if (wim_ret == NULL)
 701                 return WIMLIB_ERR_INVALID_PARAM;
 702
 703         wim = new_wim_struct();
 704         if (wim == NULL)
 705                 return WIMLIB_ERR_NOMEM;
 706
 707         ret = begin_read(wim, wim_filename_or_fd, open_flags, progress_func);
 708         if (ret) {
 709                 wimlib_free(wim);
 710                 return ret;
 711         }
 712
 713         DEBUG("Successfully opened WIM and created WIMStruct.");
 714         *wim_ret = wim;
 715         return 0;
 716 }
 717
 718 /* API function documented in wimlib.h  */
 719 WIMLIBAPI int
 720 wimlib_open_wim(const tchar *wimfile, int open_flags,
 721                 WIMStruct **wim_ret, wimlib_progress_func_t progress_func)
 722 {
 723         open_flags &= WIMLIB_OPEN_MASK_PUBLIC;
 724         return open_wim_as_WIMStruct(wimfile, open_flags, wim_ret,
 725                                      progress_func);
 726 }
 727
 728 void
 729 destroy_image_metadata(struct wim_image_metadata *imd,
 730                        struct wim_lookup_table *table,
 731                        bool free_metadata_lte)
 732 {
 733         free_dentry_tree(imd->root_dentry, table);
 734         imd->root_dentry = NULL;
 735         free_wim_security_data(imd->security_data);
 736         imd->security_data = NULL;
 737
 738         if (free_metadata_lte) {
 739                 free_lookup_table_entry(imd->metadata_lte);
 740                 imd->metadata_lte = NULL;
 741         }
 742         if (table == NULL) {
 743                 struct wim_lookup_table_entry *lte, *tmp;
 744                 list_for_each_entry_safe(lte, tmp, &imd->unhashed_streams, unhashed_list)
 745                         free_lookup_table_entry(lte);
 746         }
 747         INIT_LIST_HEAD(&imd->unhashed_streams);
 748         INIT_LIST_HEAD(&imd->inode_list);
 749 #ifdef WITH_NTFS_3G
 750         if (imd->ntfs_vol) {
 751                 do_ntfs_umount(imd->ntfs_vol);
 752                 imd->ntfs_vol = NULL;
 753         }
 754 #endif
 755 }
 756
 757 void
 758 put_image_metadata(struct wim_image_metadata *imd,
 759                    struct wim_lookup_table *table)
 760 {
 761         if (imd && --imd->refcnt == 0) {
 762                 destroy_image_metadata(imd, table, true);
 763                 FREE(imd);
 764         }
 765 }
 766
 767 /* Appends the specified image metadata structure to the array of image metadata
 768  * for a WIM, and increments the image count. */
 769 int
 770 append_image_metadata(WIMStruct *wim, struct wim_image_metadata *imd)
 771 {
 772         struct wim_image_metadata **imd_array;
 773
 774         DEBUG("Reallocating image metadata array for image_count = %u",
 775               wim->hdr.image_count + 1);
 776         imd_array = REALLOC(wim->image_metadata,
 777                             sizeof(wim->image_metadata[0]) * (wim->hdr.image_count + 1));
 778
 779         if (imd_array == NULL)
 780                 return WIMLIB_ERR_NOMEM;
 781         wim->image_metadata = imd_array;
 782         imd_array[wim->hdr.image_count++] = imd;
 783         return 0;
 784 }
 785
 786
 787 struct wim_image_metadata *
 788 new_image_metadata(void)
 789 {
 790         struct wim_image_metadata *imd;
 791
 792         imd = CALLOC(1, sizeof(*imd));
 793         if (imd) {
 794                 imd->refcnt = 1;
 795                 INIT_LIST_HEAD(&imd->inode_list);
 796                 INIT_LIST_HEAD(&imd->unhashed_streams);
 797                 DEBUG("Created new image metadata (refcnt=1)");
 798         } else {
 799                 ERROR_WITH_ERRNO("Failed to allocate new image metadata structure");
 800         }
 801         return imd;
 802 }
 803
 804 struct wim_image_metadata **
 805 new_image_metadata_array(unsigned num_images)
 806 {
 807         struct wim_image_metadata **imd_array;
 808
 809         DEBUG("Creating new image metadata array for %u images",
 810               num_images);
 811
 812         imd_array = CALLOC(num_images, sizeof(imd_array[0]));
 813
 814         if (imd_array == NULL) {
 815                 ERROR("Failed to allocate memory for %u image metadata structures",
 816                       num_images);
 817                 return NULL;
 818         }
 819         for (unsigned i = 0; i < num_images; i++) {
 820                 imd_array[i] = new_image_metadata();
 821                 if (imd_array[i] == NULL) {
 822                         for (unsigned j = 0; j < i; j++)
 823                                 put_image_metadata(imd_array[j], NULL);
 824                         FREE(imd_array);
 825                         return NULL;
 826                 }
 827         }
 828         return imd_array;
 829 }
 830
 831 /* Checksum all streams that are unhashed (other than the metadata streams),
 832  * merging them into the lookup table as needed.  This is a no-op unless the
 833  * library has previously used to add or mount an image using the same
 834  * WIMStruct. */
 835 int
 836 wim_checksum_unhashed_streams(WIMStruct *wim)
 837 {
 838         int ret;
 839
 840         if (!wim_has_metadata(wim))
 841                 return 0;
 842         for (int i = 0; i < wim->hdr.image_count; i++) {
 843                 struct wim_lookup_table_entry *lte, *tmp;
 844                 struct wim_image_metadata *imd = wim->image_metadata[i];
 845                 image_for_each_unhashed_stream_safe(lte, tmp, imd) {
 846                         struct wim_lookup_table_entry *new_lte;
 847                         ret = hash_unhashed_stream(lte, wim->lookup_table, &new_lte);
 848                         if (ret)
 849                                 return ret;
 850                         if (new_lte != lte)
 851                                 free_lookup_table_entry(lte);
 852                 }
 853         }
 854         return 0;
 855 }
 856
 857 /*
 858  * can_modify_wim - Check if a given WIM is writeable.  This is only the case if
 859  * it meets the following three conditions:
 860  *
 861  * 1. Write access is allowed to the underlying file (if any) at the filesystem level.
 862  * 2. The WIM is not part of a spanned set.
 863  * 3. The WIM_HDR_FLAG_READONLY flag is not set in the WIM header.
 864  *
 865  * Return value is 0 if writable; WIMLIB_ERR_WIM_IS_READONLY otherwise.
 866  */
 867 int
 868 can_modify_wim(WIMStruct *wim)
 869 {
 870         if (wim->filename) {
 871                 if (taccess(wim->filename, W_OK)) {
 872                         ERROR_WITH_ERRNO("Can't modify \"%"TS"\"", wim->filename);
 873                         return WIMLIB_ERR_WIM_IS_READONLY;
 874                 }
 875         }
 876         if (wim->hdr.total_parts != 1) {
 877                 ERROR("Cannot modify \"%"TS"\": is part of a split WIM",
 878                       wim->filename);
 879                 return WIMLIB_ERR_WIM_IS_READONLY;
 880         }
 881         if (wim->hdr.flags & WIM_HDR_FLAG_READONLY) {
 882                 ERROR("Cannot modify \"%"TS"\": is marked read-only",
 883                       wim->filename);
 884                 return WIMLIB_ERR_WIM_IS_READONLY;
 885         }
 886         return 0;
 887 }
 888
 889 /*
 890  * can_delete_from_wim - Check if files or images can be deleted from a given
 891  * WIM file.
 892  *
 893  * This theoretically should be exactly the same as can_modify_wim(), but
 894  * unfortunately, due to bugs in Microsoft's software that generate incorrect
 895  * reference counts for some WIM resources, we need to run expensive
 896  * verifications to make sure the reference counts are correct on all WIM
 897  * resources.  Otherwise we might delete a WIM resource whose reference count
 898  * has fallen to 0, but is actually still referenced somewhere.
 899  */
 900 int
 901 can_delete_from_wim(WIMStruct *wim)
 902 {
 903         int ret;
 904
 905         ret = can_modify_wim(wim);
 906         if (ret)
 907                 return ret;
 908         if (!wim->refcnts_ok) {
 909                 ret = wim_recalculate_refcnts(wim);
 910                 if (ret)
 911                         return ret;
 912         }
 913         return 0;
 914 }
 915
 916 /* API function documented in wimlib.h  */
 917 WIMLIBAPI void
 918 wimlib_free(WIMStruct *wim)
 919 {
 920         if (wim == NULL)
 921                 return;
 922
 923         DEBUG("Freeing WIMStruct (filename=\"%"TS"\", image_count=%u)",
 924               wim->filename, wim->hdr.image_count);
 925
 926         while (!list_empty(&wim->subwims)) {
 927                 WIMStruct *subwim;
 928
 929                 subwim = list_entry(wim->subwims.next, WIMStruct, subwim_node);
 930                 list_del(&subwim->subwim_node);
 931                 DEBUG("Freeing subwim.");
 932                 wimlib_free(subwim);
 933         }
 934
 935         if (filedes_valid(&wim->in_fd))
 936                 filedes_close(&wim->in_fd);
 937         if (filedes_valid(&wim->out_fd))
 938                 filedes_close(&wim->out_fd);
 939
 940         wimlib_lzx_free_context(wim->lzx_context);
 941
 942         free_lookup_table(wim->lookup_table);
 943
 944         FREE(wim->filename);
 945         free_wim_info(wim->wim_info);
 946         if (wim->image_metadata) {
 947                 for (unsigned i = 0; i < wim->hdr.image_count; i++)
 948                         put_image_metadata(wim->image_metadata[i], NULL);
 949                 FREE(wim->image_metadata);
 950         }
 951         FREE(wim);
 952 }
 953
 954 static bool
 955 test_locale_ctype_utf8(void)
 956 {
 957 #ifdef __WIN32__
 958         return false;
 959 #else
 960         char *ctype = nl_langinfo(CODESET);
 961
 962         return (!strstr(ctype, "UTF-8") ||
 963                 !strstr(ctype, "UTF8") ||
 964                 !strstr(ctype, "utf8") ||
 965                 !strstr(ctype, "utf-8"));
 966 #endif
 967 }
 968
 969 /* API function documented in wimlib.h  */
 970 WIMLIBAPI int
 971 wimlib_global_init(int init_flags)
 972 {
 973         static bool already_inited = false;
 974         int ret;
 975
 976         if (already_inited)
 977                 return 0;
 978         libxml_global_init();
 979         if (!(init_flags & WIMLIB_INIT_FLAG_ASSUME_UTF8)) {
 980                 wimlib_mbs_is_utf8 = test_locale_ctype_utf8();
 981         #ifdef WITH_NTFS_3G
 982                 if (!wimlib_mbs_is_utf8)
 983                         libntfs3g_global_init();
 984         #endif
 985         }
 986 #ifdef __WIN32__
 987         ret = win32_global_init(init_flags);
 988         if (ret)
 989                 return ret;
 990 #else
 991         ret = 0;
 992 #endif
 993         already_inited = true;
 994         return ret;
 995 }
 996
 997 /* API function documented in wimlib.h  */
 998 WIMLIBAPI void
 999 wimlib_global_cleanup(void)
1000 {
1001         libxml_global_cleanup();
1002         iconv_global_cleanup();
1003 #ifdef __WIN32__
1004         win32_global_cleanup();
1005 #endif
1006 }