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) 2012-2017 Eric Biggers
  10  *
  11  * This file is free software; you can redistribute it and/or modify it under
  12  * the terms of the GNU Lesser General Public License as published by the Free
  13  * Software Foundation; either version 3 of the License, or (at your option) any
  14  * later version.
  15  *
  16  * This file is distributed in the hope that it will be useful, but WITHOUT
  17  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  18  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this file; if not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 /*
  26  * This file provides the API functions wimlib_extract_image(),
  27  * wimlib_extract_image_from_pipe(), wimlib_extract_paths(), and
  28  * wimlib_extract_pathlist().  Internally, all end up calling
  29  * do_wimlib_extract_paths() and extract_trees().
  30  *
  31  * Although wimlib supports multiple extraction modes/backends (NTFS-3G, UNIX,
  32  * Win32), this file does not itself have code to extract files or directories
  33  * to any specific target; instead, it handles generic functionality and relies
  34  * on lower-level callback functions declared in `struct apply_operations' to do
  35  * the actual extraction.
  36  */
  37
  38 #ifdef HAVE_CONFIG_H
  39 #  include "config.h"
  40 #endif
  41
  42 #include <errno.h>
  43 #include <fcntl.h>
  44 #include <stdlib.h>
  45 #include <sys/stat.h>
  46 #include <unistd.h>
  47
  48 #include "wimlib/apply.h"
  49 #include "wimlib/assert.h"
  50 #include "wimlib/blob_table.h"
  51 #include "wimlib/dentry.h"
  52 #include "wimlib/encoding.h"
  53 #include "wimlib/endianness.h"
  54 #include "wimlib/error.h"
  55 #include "wimlib/metadata.h"
  56 #include "wimlib/object_id.h"
  57 #include "wimlib/pathlist.h"
  58 #include "wimlib/paths.h"
  59 #include "wimlib/pattern.h"
  60 #include "wimlib/reparse.h"
  61 #include "wimlib/resource.h"
  62 #include "wimlib/security.h"
  63 #include "wimlib/unix_data.h"
  64 #include "wimlib/wim.h"
  65 #include "wimlib/win32.h" /* for realpath() equivalent */
  66 #include "wimlib/xattr.h"
  67 #include "wimlib/xml.h"
  68
  69 #define WIMLIB_EXTRACT_FLAG_FROM_PIPE   0x80000000
  70 #define WIMLIB_EXTRACT_FLAG_IMAGEMODE   0x40000000
  71
  72 /* Keep in sync with wimlib.h  */
  73 #define WIMLIB_EXTRACT_MASK_PUBLIC                              \
  74         (WIMLIB_EXTRACT_FLAG_NTFS                       |       \
  75          WIMLIB_EXTRACT_FLAG_UNIX_DATA                  |       \
  76          WIMLIB_EXTRACT_FLAG_NO_ACLS                    |       \
  77          WIMLIB_EXTRACT_FLAG_STRICT_ACLS                |       \
  78          WIMLIB_EXTRACT_FLAG_RPFIX                      |       \
  79          WIMLIB_EXTRACT_FLAG_NORPFIX                    |       \
  80          WIMLIB_EXTRACT_FLAG_TO_STDOUT                  |       \
  81          WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES  |       \
  82          WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS         |       \
  83          WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS          |       \
  84          WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES         |       \
  85          WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS            |       \
  86          WIMLIB_EXTRACT_FLAG_GLOB_PATHS                 |       \
  87          WIMLIB_EXTRACT_FLAG_STRICT_GLOB                |       \
  88          WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES              |       \
  89          WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE  |       \
  90          WIMLIB_EXTRACT_FLAG_WIMBOOT                    |       \
  91          WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS4K           |       \
  92          WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS8K           |       \
  93          WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS16K          |       \
  94          WIMLIB_EXTRACT_FLAG_COMPACT_LZX                        \
  95          )
  96
  97 /* Send WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE or
  98  * WIMLIB_PROGRESS_MSG_EXTRACT_METADATA.  */
  99 int
 100 do_file_extract_progress(struct apply_ctx *ctx, enum wimlib_progress_msg msg)
 101 {
 102         ctx->count_until_file_progress = 500;  /* Arbitrary value to limit calls  */
 103         return extract_progress(ctx, msg);
 104 }
 105
 106 static int
 107 start_file_phase(struct apply_ctx *ctx, u64 end_file_count, enum wimlib_progress_msg msg)
 108 {
 109         ctx->progress.extract.current_file_count = 0;
 110         ctx->progress.extract.end_file_count = end_file_count;
 111         return do_file_extract_progress(ctx, msg);
 112 }
 113
 114 int
 115 start_file_structure_phase(struct apply_ctx *ctx, u64 end_file_count)
 116 {
 117         return start_file_phase(ctx, end_file_count, WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE);
 118 }
 119
 120 int
 121 start_file_metadata_phase(struct apply_ctx *ctx, u64 end_file_count)
 122 {
 123         return start_file_phase(ctx, end_file_count, WIMLIB_PROGRESS_MSG_EXTRACT_METADATA);
 124 }
 125
 126 static int
 127 end_file_phase(struct apply_ctx *ctx, enum wimlib_progress_msg msg)
 128 {
 129         ctx->progress.extract.current_file_count = ctx->progress.extract.end_file_count;
 130         return do_file_extract_progress(ctx, msg);
 131 }
 132
 133 int
 134 end_file_structure_phase(struct apply_ctx *ctx)
 135 {
 136         return end_file_phase(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_FILE_STRUCTURE);
 137 }
 138
 139 int
 140 end_file_metadata_phase(struct apply_ctx *ctx)
 141 {
 142         return end_file_phase(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_METADATA);
 143 }
 144
 145 /* Are all bytes in the specified buffer zero? */
 146 static bool
 147 is_all_zeroes(const u8 *p, const size_t size)
 148 {
 149         const u8 * const end = p + size;
 150
 151         for (; (uintptr_t)p % WORDBYTES && p != end; p++)
 152                 if (*p)
 153                         return false;
 154
 155         for (; end - p >= WORDBYTES; p += WORDBYTES)
 156                 if (*(const machine_word_t *)p)
 157                         return false;
 158
 159         for (; p != end; p++)
 160                 if (*p)
 161                         return false;
 162
 163         return true;
 164 }
 165
 166 /*
 167  * Sparse regions should be detected at the granularity of the filesystem block
 168  * size.  For now just assume 4096 bytes, which is the default block size on
 169  * NTFS and most Linux filesystems.
 170  */
 171 #define SPARSE_UNIT 4096
 172
 173 /*
 174  * Detect whether the specified buffer begins with a region of all zero bytes.
 175  * Return %true if a zero region was found or %false if a nonzero region was
 176  * found, and sets *len_ret to the length of the region.  This operates at a
 177  * granularity of SPARSE_UNIT bytes, meaning that to extend a zero region, there
 178  * must be SPARSE_UNIT zero bytes with no interruption, but to extend a nonzero
 179  * region, just one nonzero byte in the next SPARSE_UNIT bytes is sufficient.
 180  *
 181  * Note: besides compression, the WIM format doesn't yet have a way to
 182  * efficiently represent zero regions, so that's why we need to detect them
 183  * ourselves.  Things will still fall apart badly on extremely large sparse
 184  * files, but this is a start...
 185  */
 186 bool
 187 detect_sparse_region(const void *data, size_t size, size_t *len_ret)
 188 {
 189         const void *p = data;
 190         const void * const end = data + size;
 191         size_t len = 0;
 192         bool zeroes = false;
 193
 194         while (p != end) {
 195                 size_t n = min(end - p, SPARSE_UNIT);
 196                 bool z = is_all_zeroes(p, n);
 197
 198                 if (len != 0 && z != zeroes)
 199                         break;
 200                 zeroes = z;
 201                 len += n;
 202                 p += n;
 203         }
 204
 205         *len_ret = len;
 206         return zeroes;
 207 }
 208
 209 #define PWM_FOUND_WIM_HDR (-1)
 210
 211 /* Read the header for a blob in a pipable WIM.  If @pwm_hdr_ret is not NULL,
 212  * also look for a pipable WIM header and return PWM_FOUND_WIM_HDR if found.  */
 213 static int
 214 read_pwm_blob_header(WIMStruct *pwm, u8 hash_ret[SHA1_HASH_SIZE],
 215                      struct wim_reshdr *reshdr_ret,
 216                      struct wim_header_disk *pwm_hdr_ret)
 217 {
 218         int ret;
 219         struct pwm_blob_hdr blob_hdr;
 220         u64 magic;
 221
 222         ret = full_read(&pwm->in_fd, &blob_hdr, sizeof(blob_hdr));
 223         if (unlikely(ret))
 224                 goto read_error;
 225
 226         magic = le64_to_cpu(blob_hdr.magic);
 227
 228         if (magic == PWM_MAGIC && pwm_hdr_ret != NULL) {
 229                 memcpy(pwm_hdr_ret, &blob_hdr, sizeof(blob_hdr));
 230                 ret = full_read(&pwm->in_fd,
 231                                 (u8 *)pwm_hdr_ret + sizeof(blob_hdr),
 232                                 sizeof(*pwm_hdr_ret) - sizeof(blob_hdr));
 233                 if (unlikely(ret))
 234                         goto read_error;
 235                 return PWM_FOUND_WIM_HDR;
 236         }
 237
 238         if (unlikely(magic != PWM_BLOB_MAGIC)) {
 239                 ERROR("Data read on pipe is invalid (expected blob header)");
 240                 return WIMLIB_ERR_INVALID_PIPABLE_WIM;
 241         }
 242
 243         copy_hash(hash_ret, blob_hdr.hash);
 244
 245         reshdr_ret->size_in_wim = 0; /* Not available  */
 246         reshdr_ret->flags = le32_to_cpu(blob_hdr.flags);
 247         reshdr_ret->offset_in_wim = pwm->in_fd.offset;
 248         reshdr_ret->uncompressed_size = le64_to_cpu(blob_hdr.uncompressed_size);
 249
 250         if (unlikely(reshdr_ret->uncompressed_size == 0)) {
 251                 ERROR("Data read on pipe is invalid (resource is of 0 size)");
 252                 return WIMLIB_ERR_INVALID_PIPABLE_WIM;
 253         }
 254
 255         return 0;
 256
 257 read_error:
 258         if (ret == WIMLIB_ERR_UNEXPECTED_END_OF_FILE)
 259                 ERROR("The pipe ended before all needed data was sent!");
 260         else
 261                 ERROR_WITH_ERRNO("Error reading pipable WIM from pipe");
 262         return ret;
 263 }
 264
 265 static int
 266 read_blobs_from_pipe(struct apply_ctx *ctx, const struct read_blob_callbacks *cbs)
 267 {
 268         int ret;
 269         u8 hash[SHA1_HASH_SIZE];
 270         struct wim_reshdr reshdr;
 271         struct wim_header_disk pwm_hdr;
 272         struct wim_resource_descriptor rdesc;
 273         struct blob_descriptor *blob;
 274
 275         copy_guid(ctx->progress.extract.guid, ctx->wim->hdr.guid);
 276         ctx->progress.extract.part_number = ctx->wim->hdr.part_number;
 277         ctx->progress.extract.total_parts = ctx->wim->hdr.total_parts;
 278         ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN);
 279         if (ret)
 280                 return ret;
 281
 282         while (ctx->num_blobs_remaining) {
 283
 284                 ret = read_pwm_blob_header(ctx->wim, hash, &reshdr, &pwm_hdr);
 285
 286                 if (ret == PWM_FOUND_WIM_HDR) {
 287                         u16 part_number = le16_to_cpu(pwm_hdr.part_number);
 288                         u16 total_parts = le16_to_cpu(pwm_hdr.total_parts);
 289
 290                         if (part_number == ctx->progress.extract.part_number &&
 291                             total_parts == ctx->progress.extract.total_parts &&
 292                             guids_equal(pwm_hdr.guid, ctx->progress.extract.guid))
 293                                 continue;
 294
 295                         copy_guid(ctx->progress.extract.guid, pwm_hdr.guid);
 296                         ctx->progress.extract.part_number = part_number;
 297                         ctx->progress.extract.total_parts = total_parts;
 298                         ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN);
 299                         if (ret)
 300                                 return ret;
 301
 302                         continue;
 303                 }
 304
 305                 if (ret)
 306                         return ret;
 307
 308                 if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)
 309                     && (blob = lookup_blob(ctx->wim->blob_table, hash))
 310                     && (blob->out_refcnt))
 311                 {
 312                         wim_reshdr_to_desc_and_blob(&reshdr, ctx->wim, &rdesc, blob);
 313                         ret = read_blob_with_sha1(blob, cbs);
 314                         blob_unset_is_located_in_wim_resource(blob);
 315                         if (ret)
 316                                 return ret;
 317                         ctx->num_blobs_remaining--;
 318                 } else {
 319                         wim_reshdr_to_desc(&reshdr, ctx->wim, &rdesc);
 320                         ret = skip_wim_resource(&rdesc);
 321                         if (ret)
 322                                 return ret;
 323                 }
 324         }
 325
 326         return 0;
 327 }
 328
 329 static int
 330 handle_pwm_metadata_resource(WIMStruct *pwm, int image, bool is_needed)
 331 {
 332         struct blob_descriptor *blob;
 333         struct wim_reshdr reshdr;
 334         struct wim_resource_descriptor *rdesc;
 335         int ret;
 336
 337         ret = WIMLIB_ERR_NOMEM;
 338         blob = new_blob_descriptor();
 339         if (!blob)
 340                 goto out;
 341
 342         ret = read_pwm_blob_header(pwm, blob->hash, &reshdr, NULL);
 343         if (ret)
 344                 goto out;
 345
 346         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
 347         if (!(reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
 348                 ERROR("Expected metadata resource, but found non-metadata "
 349                       "resource");
 350                 goto out;
 351         }
 352
 353         ret = WIMLIB_ERR_NOMEM;
 354         rdesc = MALLOC(sizeof(*rdesc));
 355         if (!rdesc)
 356                 goto out;
 357
 358         wim_reshdr_to_desc_and_blob(&reshdr, pwm, rdesc, blob);
 359         pwm->refcnt++;
 360
 361         ret = WIMLIB_ERR_NOMEM;
 362         pwm->image_metadata[image - 1] = new_unloaded_image_metadata(blob);
 363         if (!pwm->image_metadata[image - 1])
 364                 goto out;
 365         blob = NULL;
 366
 367         /* If the metadata resource is for the image being extracted, then parse
 368          * it and save the metadata in memory.  Otherwise, skip over it.  */
 369         if (is_needed)
 370                 ret = select_wim_image(pwm, image);
 371         else
 372                 ret = skip_wim_resource(rdesc);
 373 out:
 374         free_blob_descriptor(blob);
 375         return ret;
 376 }
 377
 378 /* Creates a temporary file opened for writing.  The open file descriptor is
 379  * returned in @fd_ret and its name is returned in @name_ret (dynamically
 380  * allocated).  */
 381 static int
 382 create_temporary_file(struct filedes *fd_ret, tchar **name_ret)
 383 {
 384         tchar *name;
 385         int raw_fd;
 386
 387 #ifdef __WIN32__
 388 retry:
 389         name = _wtempnam(NULL, L"wimlib");
 390         if (!name) {
 391                 ERROR_WITH_ERRNO("Failed to create temporary filename");
 392                 return WIMLIB_ERR_NOMEM;
 393         }
 394         raw_fd = _wopen(name, O_WRONLY | O_CREAT | O_EXCL | O_BINARY |
 395                         _O_SHORT_LIVED, 0600);
 396         if (raw_fd < 0 && errno == EEXIST) {
 397                 FREE(name);
 398                 goto retry;
 399         }
 400 #else /* __WIN32__ */
 401         const char *tmpdir = getenv("TMPDIR");
 402         if (!tmpdir)
 403                 tmpdir = P_tmpdir;
 404         name = MALLOC(strlen(tmpdir) + 1 + 6 + 6 + 1);
 405         if (!name)
 406                 return WIMLIB_ERR_NOMEM;
 407         sprintf(name, "%s/wimlibXXXXXX", tmpdir);
 408         raw_fd = mkstemp(name);
 409 #endif /* !__WIN32__ */
 410
 411         if (raw_fd < 0) {
 412                 ERROR_WITH_ERRNO("Failed to create temporary file "
 413                                  "\"%"TS"\"", name);
 414                 FREE(name);
 415                 return WIMLIB_ERR_OPEN;
 416         }
 417
 418         filedes_init(fd_ret, raw_fd);
 419         *name_ret = name;
 420         return 0;
 421 }
 422
 423 static int
 424 begin_extract_blob(struct blob_descriptor *blob, void *_ctx)
 425 {
 426         struct apply_ctx *ctx = _ctx;
 427
 428         if (unlikely(blob->out_refcnt > MAX_OPEN_FILES))
 429                 return create_temporary_file(&ctx->tmpfile_fd, &ctx->tmpfile_name);
 430
 431         return call_begin_blob(blob, ctx->saved_cbs);
 432 }
 433
 434 static int
 435 extract_chunk(const struct blob_descriptor *blob, u64 offset,
 436               const void *chunk, size_t size, void *_ctx)
 437 {
 438         struct apply_ctx *ctx = _ctx;
 439         union wimlib_progress_info *progress = &ctx->progress;
 440         bool last = (offset + size == blob->size);
 441         int ret;
 442
 443         if (likely(ctx->supported_features.hard_links)) {
 444                 progress->extract.completed_bytes +=
 445                         (u64)size * blob->out_refcnt;
 446                 if (last)
 447                         progress->extract.completed_streams += blob->out_refcnt;
 448         } else {
 449                 const struct blob_extraction_target *targets =
 450                         blob_extraction_targets(blob);
 451                 for (u32 i = 0; i < blob->out_refcnt; i++) {
 452                         const struct wim_inode *inode = targets[i].inode;
 453                         const struct wim_dentry *dentry;
 454
 455                         inode_for_each_extraction_alias(dentry, inode) {
 456                                 progress->extract.completed_bytes += size;
 457                                 if (last)
 458                                         progress->extract.completed_streams++;
 459                         }
 460                 }
 461         }
 462         if (progress->extract.completed_bytes >= ctx->next_progress) {
 463
 464                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
 465                 if (ret)
 466                         return ret;
 467
 468                 set_next_progress(progress->extract.completed_bytes,
 469                                   progress->extract.total_bytes,
 470                                   &ctx->next_progress);
 471         }
 472
 473         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
 474                 /* Just extracting to temporary file for now.  */
 475                 ret = full_write(&ctx->tmpfile_fd, chunk, size);
 476                 if (ret) {
 477                         ERROR_WITH_ERRNO("Error writing data to "
 478                                          "temporary file \"%"TS"\"",
 479                                          ctx->tmpfile_name);
 480                 }
 481                 return ret;
 482         }
 483
 484         return call_continue_blob(blob, offset, chunk, size, ctx->saved_cbs);
 485 }
 486
 487 /* Copy the blob's data from the temporary file to each of its targets.
 488  *
 489  * This is executed only in the very uncommon case that a blob is being
 490  * extracted to more than MAX_OPEN_FILES targets!  */
 491 static int
 492 extract_from_tmpfile(const tchar *tmpfile_name,
 493                      const struct blob_descriptor *orig_blob,
 494                      const struct read_blob_callbacks *cbs)
 495 {
 496         struct blob_descriptor tmpfile_blob;
 497         const struct blob_extraction_target *targets = blob_extraction_targets(orig_blob);
 498         int ret;
 499
 500         memcpy(&tmpfile_blob, orig_blob, sizeof(struct blob_descriptor));
 501         tmpfile_blob.blob_location = BLOB_IN_FILE_ON_DISK;
 502         tmpfile_blob.file_on_disk = (tchar *)tmpfile_name;
 503         tmpfile_blob.out_refcnt = 1;
 504
 505         for (u32 i = 0; i < orig_blob->out_refcnt; i++) {
 506                 tmpfile_blob.inline_blob_extraction_targets[0] = targets[i];
 507                 ret = read_blob_with_cbs(&tmpfile_blob, cbs);
 508                 if (ret)
 509                         return ret;
 510         }
 511         return 0;
 512 }
 513
 514 static int
 515 end_extract_blob(struct blob_descriptor *blob, int status, void *_ctx)
 516 {
 517         struct apply_ctx *ctx = _ctx;
 518
 519         if (unlikely(filedes_valid(&ctx->tmpfile_fd))) {
 520                 filedes_close(&ctx->tmpfile_fd);
 521                 if (!status)
 522                         status = extract_from_tmpfile(ctx->tmpfile_name, blob,
 523                                                       ctx->saved_cbs);
 524                 filedes_invalidate(&ctx->tmpfile_fd);
 525                 tunlink(ctx->tmpfile_name);
 526                 FREE(ctx->tmpfile_name);
 527                 return status;
 528         }
 529
 530         return call_end_blob(blob, status, ctx->saved_cbs);
 531 }
 532
 533 /*
 534  * Read the list of blobs to extract and feed their data into the specified
 535  * callback functions.
 536  *
 537  * This handles checksumming each blob.
 538  *
 539  * This also handles sending WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS.
 540  *
 541  * This also works if the WIM is being read from a pipe.
 542  *
 543  * This also will split up blobs that will need to be extracted to more than
 544  * MAX_OPEN_FILES locations, as measured by the 'out_refcnt' of each blob.
 545  * Therefore, the apply_operations implementation need not worry about running
 546  * out of file descriptors, unless it might open more than one file descriptor
 547  * per 'blob_extraction_target' (e.g. Win32 currently might because the
 548  * destination file system might not support hard links).
 549  */
 550 int
 551 extract_blob_list(struct apply_ctx *ctx, const struct read_blob_callbacks *cbs)
 552 {
 553         struct read_blob_callbacks wrapper_cbs = {
 554                 .begin_blob     = begin_extract_blob,
 555                 .continue_blob  = extract_chunk,
 556                 .end_blob       = end_extract_blob,
 557                 .ctx            = ctx,
 558         };
 559         ctx->saved_cbs = cbs;
 560         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
 561                 return read_blobs_from_pipe(ctx, &wrapper_cbs);
 562         } else {
 563                 return read_blob_list(&ctx->blob_list,
 564                                       offsetof(struct blob_descriptor,
 565                                                extraction_list),
 566                                       &wrapper_cbs, VERIFY_BLOB_HASHES);
 567         }
 568 }
 569
 570 /* Extract a WIM dentry to standard output.
 571  *
 572  * This obviously doesn't make sense in all cases.  We return an error if the
 573  * dentry does not correspond to a regular file.  Otherwise we extract the
 574  * unnamed data stream only.  */
 575 static int
 576 extract_dentry_to_stdout(struct wim_dentry *dentry,
 577                          const struct blob_table *blob_table)
 578 {
 579         struct wim_inode *inode = dentry->d_inode;
 580         struct blob_descriptor *blob;
 581         struct filedes _stdout;
 582
 583         if (inode->i_attributes & (FILE_ATTRIBUTE_REPARSE_POINT |
 584                                    FILE_ATTRIBUTE_DIRECTORY |
 585                                    FILE_ATTRIBUTE_ENCRYPTED))
 586         {
 587                 ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
 588                       "extracted to standard output", dentry_full_path(dentry));
 589                 return WIMLIB_ERR_NOT_A_REGULAR_FILE;
 590         }
 591
 592         blob = inode_get_blob_for_unnamed_data_stream(inode, blob_table);
 593         if (!blob) {
 594                 const u8 *hash = inode_get_hash_of_unnamed_data_stream(inode);
 595                 if (!is_zero_hash(hash))
 596                         return blob_not_found_error(inode, hash);
 597                 return 0;
 598         }
 599
 600         filedes_init(&_stdout, STDOUT_FILENO);
 601         return extract_blob_to_fd(blob, &_stdout);
 602 }
 603
 604 static int
 605 extract_dentries_to_stdout(struct wim_dentry **dentries, size_t num_dentries,
 606                            const struct blob_table *blob_table)
 607 {
 608         for (size_t i = 0; i < num_dentries; i++) {
 609                 int ret = extract_dentry_to_stdout(dentries[i], blob_table);
 610                 if (ret)
 611                         return ret;
 612         }
 613         return 0;
 614 }
 615
 616 /**********************************************************************/
 617
 618 /*
 619  * Removes duplicate dentries from the array.
 620  *
 621  * Returns the new number of dentries, packed at the front of the array.
 622  */
 623 static size_t
 624 remove_duplicate_trees(struct wim_dentry **trees, size_t num_trees)
 625 {
 626         size_t i, j = 0;
 627         for (i = 0; i < num_trees; i++) {
 628                 if (!trees[i]->d_tmp_flag) {
 629                         /* Found distinct dentry.  */
 630                         trees[i]->d_tmp_flag = 1;
 631                         trees[j++] = trees[i];
 632                 }
 633         }
 634         for (i = 0; i < j; i++)
 635                 trees[i]->d_tmp_flag = 0;
 636         return j;
 637 }
 638
 639 /*
 640  * Remove dentries that are descendants of other dentries in the array.
 641  *
 642  * Returns the new number of dentries, packed at the front of the array.
 643  */
 644 static size_t
 645 remove_contained_trees(struct wim_dentry **trees, size_t num_trees)
 646 {
 647         size_t i, j = 0;
 648         for (i = 0; i < num_trees; i++)
 649                 trees[i]->d_tmp_flag = 1;
 650         for (i = 0; i < num_trees; i++) {
 651                 struct wim_dentry *d = trees[i];
 652                 while (!dentry_is_root(d)) {
 653                         d = d->d_parent;
 654                         if (d->d_tmp_flag)
 655                                 goto tree_contained;
 656                 }
 657                 trees[j++] = trees[i];
 658                 continue;
 659
 660         tree_contained:
 661                 trees[i]->d_tmp_flag = 0;
 662         }
 663
 664         for (i = 0; i < j; i++)
 665                 trees[i]->d_tmp_flag = 0;
 666         return j;
 667 }
 668
 669 static int
 670 dentry_append_to_list(struct wim_dentry *dentry, void *_dentry_list)
 671 {
 672         struct list_head *dentry_list = _dentry_list;
 673         list_add_tail(&dentry->d_extraction_list_node, dentry_list);
 674         return 0;
 675 }
 676
 677 static void
 678 dentry_reset_extraction_list_node(struct wim_dentry *dentry)
 679 {
 680         dentry->d_extraction_list_node = (struct list_head){NULL, NULL};
 681 }
 682
 683 static int
 684 dentry_delete_from_list(struct wim_dentry *dentry, void *_ignore)
 685 {
 686         if (will_extract_dentry(dentry)) {
 687                 list_del(&dentry->d_extraction_list_node);
 688                 dentry_reset_extraction_list_node(dentry);
 689         }
 690         return 0;
 691 }
 692
 693 /*
 694  * Build the preliminary list of dentries to be extracted.
 695  *
 696  * The list maintains the invariant that if d1 and d2 are in the list and d1 is
 697  * an ancestor of d2, then d1 appears before d2 in the list.
 698  */
 699 static void
 700 build_dentry_list(struct list_head *dentry_list, struct wim_dentry **trees,
 701                   size_t num_trees, bool add_ancestors)
 702 {
 703         INIT_LIST_HEAD(dentry_list);
 704
 705         /* Add the trees recursively.  */
 706         for (size_t i = 0; i < num_trees; i++)
 707                 for_dentry_in_tree(trees[i], dentry_append_to_list, dentry_list);
 708
 709         /* If requested, add ancestors of the trees.  */
 710         if (add_ancestors) {
 711                 for (size_t i = 0; i < num_trees; i++) {
 712                         struct wim_dentry *dentry = trees[i];
 713                         struct wim_dentry *ancestor;
 714                         struct list_head *place_after;
 715
 716                         if (dentry_is_root(dentry))
 717                                 continue;
 718
 719                         place_after = dentry_list;
 720                         ancestor = dentry;
 721                         do {
 722                                 ancestor = ancestor->d_parent;
 723                                 if (will_extract_dentry(ancestor)) {
 724                                         place_after = &ancestor->d_extraction_list_node;
 725                                         break;
 726                                 }
 727                         } while (!dentry_is_root(ancestor));
 728
 729                         ancestor = dentry;
 730                         do {
 731                                 ancestor = ancestor->d_parent;
 732                                 if (will_extract_dentry(ancestor))
 733                                         break;
 734                                 list_add(&ancestor->d_extraction_list_node, place_after);
 735                         } while (!dentry_is_root(ancestor));
 736                 }
 737         }
 738 }
 739
 740 static void
 741 destroy_dentry_list(struct list_head *dentry_list)
 742 {
 743         struct wim_dentry *dentry, *tmp;
 744         struct wim_inode *inode;
 745
 746         list_for_each_entry_safe(dentry, tmp, dentry_list, d_extraction_list_node) {
 747                 inode = dentry->d_inode;
 748                 dentry_reset_extraction_list_node(dentry);
 749                 inode->i_visited = 0;
 750                 inode->i_can_externally_back = 0;
 751                 if ((void *)dentry->d_extraction_name != (void *)dentry->d_name)
 752                         FREE(dentry->d_extraction_name);
 753                 dentry->d_extraction_name = NULL;
 754                 dentry->d_extraction_name_nchars = 0;
 755         }
 756 }
 757
 758 static void
 759 destroy_blob_list(struct list_head *blob_list)
 760 {
 761         struct blob_descriptor *blob;
 762
 763         list_for_each_entry(blob, blob_list, extraction_list)
 764                 if (blob->out_refcnt > ARRAY_LEN(blob->inline_blob_extraction_targets))
 765                         FREE(blob->blob_extraction_targets);
 766 }
 767
 768 #ifdef __WIN32__
 769 static const utf16lechar replacement_char = cpu_to_le16(0xfffd);
 770 #else
 771 static const utf16lechar replacement_char = cpu_to_le16('?');
 772 #endif
 773
 774 static bool
 775 file_name_valid(utf16lechar *name, size_t num_chars, bool fix)
 776 {
 777         size_t i;
 778
 779         if (num_chars == 0)
 780                 return true;
 781         for (i = 0; i < num_chars; i++) {
 782                 switch (le16_to_cpu(name[i])) {
 783         #ifdef __WIN32__
 784                 case '\x01'...'\x1F':
 785                 case '\\':
 786                 case ':':
 787                 case '*':
 788                 case '?':
 789                 case '"':
 790                 case '<':
 791                 case '>':
 792                 case '|':
 793         #endif
 794                 case '/':
 795                 case '\0':
 796                         if (fix)
 797                                 name[i] = replacement_char;
 798                         else
 799                                 return false;
 800                 }
 801         }
 802
 803         return true;
 804 }
 805
 806 static int
 807 dentry_calculate_extraction_name(struct wim_dentry *dentry,
 808                                  struct apply_ctx *ctx)
 809 {
 810         int ret;
 811
 812         if (dentry_is_root(dentry))
 813                 return 0;
 814
 815 #ifdef WITH_NTFS_3G
 816         if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
 817                 dentry->d_extraction_name = dentry->d_name;
 818                 dentry->d_extraction_name_nchars = dentry->d_name_nbytes /
 819                                                    sizeof(utf16lechar);
 820                 return 0;
 821         }
 822 #endif
 823
 824         if (!ctx->supported_features.case_sensitive_filenames) {
 825                 struct wim_dentry *other;
 826                 dentry_for_each_ci_match(other, dentry) {
 827                         if (will_extract_dentry(other)) {
 828                                 if (ctx->extract_flags &
 829                                     WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS) {
 830                                         WARNING("\"%"TS"\" has the same "
 831                                                 "case-insensitive name as "
 832                                                 "\"%"TS"\"; extracting "
 833                                                 "dummy name instead",
 834                                                 dentry_full_path(dentry),
 835                                                 dentry_full_path(other));
 836                                         goto out_replace;
 837                                 } else {
 838                                         WARNING("Not extracting \"%"TS"\": "
 839                                                 "has same case-insensitive "
 840                                                 "name as \"%"TS"\"",
 841                                                 dentry_full_path(dentry),
 842                                                 dentry_full_path(other));
 843                                         goto skip_dentry;
 844                                 }
 845                         }
 846                 }
 847         }
 848
 849         if (file_name_valid(dentry->d_name, dentry->d_name_nbytes / 2, false)) {
 850                 size_t nbytes = 0;
 851                 ret = utf16le_get_tstr(dentry->d_name,
 852                                        dentry->d_name_nbytes,
 853                                        (const tchar **)&dentry->d_extraction_name,
 854                                        &nbytes);
 855                 dentry->d_extraction_name_nchars = nbytes / sizeof(tchar);
 856                 return ret;
 857         } else {
 858                 if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
 859                 {
 860                         WARNING("\"%"TS"\" has an invalid filename "
 861                                 "that is not supported on this platform; "
 862                                 "extracting dummy name instead",
 863                                 dentry_full_path(dentry));
 864                         goto out_replace;
 865                 } else {
 866                         WARNING("Not extracting \"%"TS"\": has an invalid filename "
 867                                 "that is not supported on this platform",
 868                                 dentry_full_path(dentry));
 869                         goto skip_dentry;
 870                 }
 871         }
 872
 873 out_replace:
 874         {
 875                 utf16lechar utf16_name_copy[dentry->d_name_nbytes / 2];
 876
 877                 memcpy(utf16_name_copy, dentry->d_name, dentry->d_name_nbytes);
 878                 file_name_valid(utf16_name_copy, dentry->d_name_nbytes / 2, true);
 879
 880                 const tchar *tchar_name;
 881                 size_t tchar_nchars;
 882
 883                 ret = utf16le_get_tstr(utf16_name_copy,
 884                                        dentry->d_name_nbytes,
 885                                        &tchar_name, &tchar_nchars);
 886                 if (ret)
 887                         return ret;
 888
 889                 tchar_nchars /= sizeof(tchar);
 890
 891                 size_t fixed_name_num_chars = tchar_nchars;
 892                 tchar fixed_name[tchar_nchars + 50];
 893
 894                 tmemcpy(fixed_name, tchar_name, tchar_nchars);
 895                 fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
 896                                                  T(" (invalid filename #%lu)"),
 897                                                  ++ctx->invalid_sequence);
 898
 899                 utf16le_put_tstr(tchar_name);
 900
 901                 dentry->d_extraction_name = TSTRDUP(fixed_name);
 902                 if (!dentry->d_extraction_name)
 903                         return WIMLIB_ERR_NOMEM;
 904                 dentry->d_extraction_name_nchars = fixed_name_num_chars;
 905         }
 906         return 0;
 907
 908 skip_dentry:
 909         for_dentry_in_tree(dentry, dentry_delete_from_list, NULL);
 910         return 0;
 911 }
 912
 913 /*
 914  * Calculate the actual filename component at which each WIM dentry will be
 915  * extracted, with special handling for dentries that are unsupported by the
 916  * extraction backend or have invalid names.
 917  *
 918  * ctx->supported_features must be filled in.
 919  *
 920  * Possible error codes: WIMLIB_ERR_NOMEM, WIMLIB_ERR_INVALID_UTF16_STRING
 921  */
 922 static int
 923 dentry_list_calculate_extraction_names(struct list_head *dentry_list,
 924                                        struct apply_ctx *ctx)
 925 {
 926         struct list_head *prev, *cur;
 927
 928         /* Can't use list_for_each_entry() because a call to
 929          * dentry_calculate_extraction_name() may delete the current dentry and
 930          * its children from the list.  */
 931
 932         prev = dentry_list;
 933         for (;;) {
 934                 struct wim_dentry *dentry;
 935                 int ret;
 936
 937                 cur = prev->next;
 938                 if (cur == dentry_list)
 939                         break;
 940
 941                 dentry = list_entry(cur, struct wim_dentry, d_extraction_list_node);
 942
 943                 ret = dentry_calculate_extraction_name(dentry, ctx);
 944                 if (ret)
 945                         return ret;
 946
 947                 if (prev->next == cur)
 948                         prev = cur;
 949                 else
 950                         ; /* Current dentry and its children (which follow in
 951                              the list) were deleted.  prev stays the same.  */
 952         }
 953         return 0;
 954 }
 955
 956 static int
 957 dentry_resolve_streams(struct wim_dentry *dentry, int extract_flags,
 958                        struct blob_table *blob_table)
 959 {
 960         struct wim_inode *inode = dentry->d_inode;
 961         struct blob_descriptor *blob;
 962         int ret;
 963         bool force = false;
 964
 965         /* Special case:  when extracting from a pipe, the WIM blob table is
 966          * initially empty, so "resolving" an inode's streams is initially not
 967          * possible.  However, we still need to keep track of which blobs,
 968          * identified by SHA-1 message digests, need to be extracted, so we
 969          * "resolve" the inode's streams anyway by allocating a 'struct
 970          * blob_descriptor' for each one.  */
 971         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
 972                 force = true;
 973         ret = inode_resolve_streams(inode, blob_table, force);
 974         if (ret)
 975                 return ret;
 976         for (unsigned i = 0; i < inode->i_num_streams; i++) {
 977                 blob = stream_blob_resolved(&inode->i_streams[i]);
 978                 if (blob)
 979                         blob->out_refcnt = 0;
 980         }
 981         return 0;
 982 }
 983
 984 /*
 985  * For each dentry to be extracted, resolve all streams in the corresponding
 986  * inode and set 'out_refcnt' in all referenced blob_descriptors to 0.
 987  *
 988  * Possible error codes: WIMLIB_ERR_RESOURCE_NOT_FOUND, WIMLIB_ERR_NOMEM.
 989  */
 990 static int
 991 dentry_list_resolve_streams(struct list_head *dentry_list,
 992                             struct apply_ctx *ctx)
 993 {
 994         struct wim_dentry *dentry;
 995         int ret;
 996
 997         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
 998                 ret = dentry_resolve_streams(dentry,
 999                                              ctx->extract_flags,
1000                                              ctx->wim->blob_table);
1001                 if (ret)
1002                         return ret;
1003         }
1004         return 0;
1005 }
1006
1007 static int
1008 ref_stream(struct wim_inode_stream *strm, struct wim_dentry *dentry,
1009            struct apply_ctx *ctx)
1010 {
1011         struct wim_inode *inode = dentry->d_inode;
1012         struct blob_descriptor *blob = stream_blob_resolved(strm);
1013         struct blob_extraction_target *targets;
1014
1015         if (!blob)
1016                 return 0;
1017
1018         /* Tally the size only for each actual extraction of the stream (not
1019          * additional hard links to the inode).  */
1020         if (inode->i_visited && ctx->supported_features.hard_links)
1021                 return 0;
1022
1023         ctx->progress.extract.total_bytes += blob->size;
1024         ctx->progress.extract.total_streams++;
1025
1026         if (inode->i_visited)
1027                 return 0;
1028
1029         /* Add each blob to 'ctx->blob_list' only one time, regardless of how
1030          * many extraction targets it will have.  */
1031         if (blob->out_refcnt == 0) {
1032                 list_add_tail(&blob->extraction_list, &ctx->blob_list);
1033                 ctx->num_blobs_remaining++;
1034         }
1035
1036         /* Set this stream as an extraction target of 'blob'.  */
1037
1038         if (blob->out_refcnt < ARRAY_LEN(blob->inline_blob_extraction_targets)) {
1039                 targets = blob->inline_blob_extraction_targets;
1040         } else {
1041                 struct blob_extraction_target *prev_targets;
1042                 size_t alloc_blob_extraction_targets;
1043
1044                 if (blob->out_refcnt == ARRAY_LEN(blob->inline_blob_extraction_targets)) {
1045                         prev_targets = NULL;
1046                         alloc_blob_extraction_targets = ARRAY_LEN(blob->inline_blob_extraction_targets);
1047                 } else {
1048                         prev_targets = blob->blob_extraction_targets;
1049                         alloc_blob_extraction_targets = blob->alloc_blob_extraction_targets;
1050                 }
1051
1052                 if (blob->out_refcnt == alloc_blob_extraction_targets) {
1053                         alloc_blob_extraction_targets *= 2;
1054                         targets = REALLOC(prev_targets,
1055                                           alloc_blob_extraction_targets *
1056                                           sizeof(targets[0]));
1057                         if (!targets)
1058                                 return WIMLIB_ERR_NOMEM;
1059                         if (!prev_targets) {
1060                                 memcpy(targets,
1061                                        blob->inline_blob_extraction_targets,
1062                                        sizeof(blob->inline_blob_extraction_targets));
1063                         }
1064                         blob->blob_extraction_targets = targets;
1065                         blob->alloc_blob_extraction_targets = alloc_blob_extraction_targets;
1066                 }
1067                 targets = blob->blob_extraction_targets;
1068         }
1069         targets[blob->out_refcnt].inode = inode;
1070         targets[blob->out_refcnt].stream = strm;
1071         blob->out_refcnt++;
1072         return 0;
1073 }
1074
1075 static int
1076 ref_stream_if_needed(struct wim_dentry *dentry, struct wim_inode *inode,
1077                      struct wim_inode_stream *strm, struct apply_ctx *ctx)
1078 {
1079         bool need_stream = false;
1080         switch (strm->stream_type) {
1081         case STREAM_TYPE_DATA:
1082                 if (stream_is_named(strm)) {
1083                         /* Named data stream  */
1084                         if (ctx->supported_features.named_data_streams)
1085                                 need_stream = true;
1086                 } else if (!(inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
1087                                                     FILE_ATTRIBUTE_ENCRYPTED))
1088                            && !(inode_is_symlink(inode)
1089                                 && !ctx->supported_features.reparse_points
1090                                 && ctx->supported_features.symlink_reparse_points))
1091                 {
1092                         /*
1093                          * Unnamed data stream.  Skip if any of the following is true:
1094                          *
1095                          * - file is a directory
1096                          * - file is encrypted
1097                          * - backend needs to create the file as UNIX symlink
1098                          * - backend will extract the stream as externally
1099                          *   backed from the WIM archive itself
1100                          */
1101                         if (ctx->apply_ops->will_back_from_wim) {
1102                                 int ret = (*ctx->apply_ops->will_back_from_wim)(dentry, ctx);
1103                                 if (ret > 0) /* Error?  */
1104                                         return ret;
1105                                 if (ret < 0) /* Won't externally back?  */
1106                                         need_stream = true;
1107                         } else {
1108                                 need_stream = true;
1109                         }
1110                 }
1111                 break;
1112         case STREAM_TYPE_REPARSE_POINT:
1113                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT);
1114                 if (ctx->supported_features.reparse_points ||
1115                     (inode_is_symlink(inode) &&
1116                      ctx->supported_features.symlink_reparse_points))
1117                         need_stream = true;
1118                 break;
1119         case STREAM_TYPE_EFSRPC_RAW_DATA:
1120                 wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED);
1121                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
1122                         if (ctx->supported_features.encrypted_directories)
1123                                 need_stream = true;
1124                 } else {
1125                         if (ctx->supported_features.encrypted_files)
1126                                 need_stream = true;
1127                 }
1128                 break;
1129         }
1130         if (need_stream)
1131                 return ref_stream(strm, dentry, ctx);
1132         return 0;
1133 }
1134
1135 static int
1136 dentry_ref_streams(struct wim_dentry *dentry, struct apply_ctx *ctx)
1137 {
1138         struct wim_inode *inode = dentry->d_inode;
1139         for (unsigned i = 0; i < inode->i_num_streams; i++) {
1140                 int ret = ref_stream_if_needed(dentry, inode,
1141                                                &inode->i_streams[i], ctx);
1142                 if (ret)
1143                         return ret;
1144         }
1145         inode->i_visited = 1;
1146         return 0;
1147 }
1148
1149 /*
1150  * Given a list of dentries to be extracted, build the list of blobs that need
1151  * to be extracted, and for each blob determine the streams to which that blob
1152  * will be extracted.
1153  *
1154  * This also initializes the extract progress info with byte and blob
1155  * information.
1156  *
1157  * ctx->supported_features must be filled in.
1158  */
1159 static int
1160 dentry_list_ref_streams(struct list_head *dentry_list, struct apply_ctx *ctx)
1161 {
1162         struct wim_dentry *dentry;
1163         int ret;
1164
1165         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1166                 ret = dentry_ref_streams(dentry, ctx);
1167                 if (ret)
1168                         return ret;
1169         }
1170         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1171                 dentry->d_inode->i_visited = 0;
1172         return 0;
1173 }
1174
1175 static void
1176 dentry_list_build_inode_alias_lists(struct list_head *dentry_list)
1177 {
1178         struct wim_dentry *dentry;
1179
1180         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1181                 dentry->d_inode->i_first_extraction_alias = NULL;
1182
1183         list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
1184                 dentry->d_next_extraction_alias = dentry->d_inode->i_first_extraction_alias;
1185                 dentry->d_inode->i_first_extraction_alias = dentry;
1186         }
1187 }
1188
1189 static void
1190 inode_tally_features(const struct wim_inode *inode,
1191                      struct wim_features *features)
1192 {
1193         if (inode->i_attributes & FILE_ATTRIBUTE_READONLY)
1194                 features->readonly_files++;
1195         if (inode->i_attributes & FILE_ATTRIBUTE_HIDDEN)
1196                 features->hidden_files++;
1197         if (inode->i_attributes & FILE_ATTRIBUTE_SYSTEM)
1198                 features->system_files++;
1199         if (inode->i_attributes & FILE_ATTRIBUTE_ARCHIVE)
1200                 features->archive_files++;
1201         if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED)
1202                 features->compressed_files++;
1203         if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
1204                 if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
1205                         features->encrypted_directories++;
1206                 else
1207                         features->encrypted_files++;
1208         }
1209         if (inode->i_attributes & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
1210                 features->not_context_indexed_files++;
1211         if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE)
1212                 features->sparse_files++;
1213         if (inode_has_named_data_stream(inode))
1214                 features->named_data_streams++;
1215         if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1216                 features->reparse_points++;
1217                 if (inode_is_symlink(inode))
1218                         features->symlink_reparse_points++;
1219                 else
1220                         features->other_reparse_points++;
1221         }
1222         if (inode_has_security_descriptor(inode))
1223                 features->security_descriptors++;
1224         if (inode_has_unix_data(inode))
1225                 features->unix_data++;
1226         if (inode_has_object_id(inode))
1227                 features->object_ids++;
1228         if (inode_has_linux_xattrs(inode))
1229                 features->linux_xattrs++;
1230 }
1231
1232 /* Tally features necessary to extract a dentry and the corresponding inode.  */
1233 static void
1234 dentry_tally_features(struct wim_dentry *dentry, struct wim_features *features)
1235 {
1236         struct wim_inode *inode = dentry->d_inode;
1237
1238         if (dentry_has_short_name(dentry))
1239                 features->short_names++;
1240
1241         if (inode->i_visited) {
1242                 features->hard_links++;
1243         } else {
1244                 inode_tally_features(inode, features);
1245                 inode->i_visited = 1;
1246         }
1247 }
1248
1249 /* Tally the features necessary to extract the specified dentries.  */
1250 static void
1251 dentry_list_get_features(struct list_head *dentry_list,
1252                          struct wim_features *features)
1253 {
1254         struct wim_dentry *dentry;
1255
1256         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1257                 dentry_tally_features(dentry, features);
1258
1259         list_for_each_entry(dentry, dentry_list, d_extraction_list_node)
1260                 dentry->d_inode->i_visited = 0;
1261 }
1262
1263 static int
1264 do_feature_check(const struct wim_features *required_features,
1265                  const struct wim_features *supported_features,
1266                  int extract_flags)
1267 {
1268         /* Encrypted files.  */
1269         if (required_features->encrypted_files &&
1270             !supported_features->encrypted_files)
1271                 WARNING("Ignoring EFS-encrypted data of %lu files",
1272                         required_features->encrypted_files);
1273
1274         /* Named data streams.  */
1275         if (required_features->named_data_streams &&
1276             !supported_features->named_data_streams)
1277                 WARNING("Ignoring named data streams of %lu files",
1278                         required_features->named_data_streams);
1279
1280         /* File attributes.  */
1281         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
1282
1283                 if (required_features->readonly_files &&
1284                     !supported_features->readonly_files)
1285                         WARNING("Ignoring FILE_ATTRIBUTE_READONLY of %lu files",
1286                                 required_features->readonly_files);
1287
1288                 if (required_features->hidden_files &&
1289                     !supported_features->hidden_files)
1290                         WARNING("Ignoring FILE_ATTRIBUTE_HIDDEN of %lu files",
1291                                 required_features->hidden_files);
1292
1293                 if (required_features->system_files &&
1294                     !supported_features->system_files)
1295                         WARNING("Ignoring FILE_ATTRIBUTE_SYSTEM of %lu files",
1296                                 required_features->system_files);
1297
1298                 /* Note: Don't bother the user about FILE_ATTRIBUTE_ARCHIVE.
1299                  * We're an archive program, so theoretically we can do what we
1300                  * want with it.  */
1301
1302                 if (required_features->compressed_files &&
1303                     !supported_features->compressed_files)
1304                         WARNING("Ignoring FILE_ATTRIBUTE_COMPRESSED of %lu files",
1305                                 required_features->compressed_files);
1306
1307                 if (required_features->not_context_indexed_files &&
1308                     !supported_features->not_context_indexed_files)
1309                         WARNING("Ignoring FILE_ATTRIBUTE_NOT_CONTENT_INDEXED of %lu files",
1310                                 required_features->not_context_indexed_files);
1311
1312                 if (required_features->sparse_files &&
1313                     !supported_features->sparse_files)
1314                         WARNING("Ignoring FILE_ATTRIBUTE_SPARSE_FILE of %lu files",
1315                                 required_features->sparse_files);
1316
1317                 if (required_features->encrypted_directories &&
1318                     !supported_features->encrypted_directories)
1319                         WARNING("Ignoring FILE_ATTRIBUTE_ENCRYPTED of %lu directories",
1320                                 required_features->encrypted_directories);
1321         }
1322
1323         /* Hard links.  */
1324         if (required_features->hard_links && !supported_features->hard_links)
1325                 WARNING("Extracting %lu hard links as independent files",
1326                         required_features->hard_links);
1327
1328         /* Symbolic links and reparse points.  */
1329         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS) &&
1330             required_features->symlink_reparse_points &&
1331             !supported_features->symlink_reparse_points &&
1332             !supported_features->reparse_points)
1333         {
1334                 ERROR("Extraction backend does not support symbolic links!");
1335                 return WIMLIB_ERR_UNSUPPORTED;
1336         }
1337         if (required_features->reparse_points &&
1338             !supported_features->reparse_points)
1339         {
1340                 if (supported_features->symlink_reparse_points) {
1341                         if (required_features->other_reparse_points) {
1342                                 WARNING("Ignoring reparse data of %lu non-symlink/junction files",
1343                                         required_features->other_reparse_points);
1344                         }
1345                 } else {
1346                         WARNING("Ignoring reparse data of %lu files",
1347                                 required_features->reparse_points);
1348                 }
1349         }
1350
1351         /* Security descriptors.  */
1352         if (((extract_flags & (WIMLIB_EXTRACT_FLAG_STRICT_ACLS |
1353                                WIMLIB_EXTRACT_FLAG_UNIX_DATA))
1354              == WIMLIB_EXTRACT_FLAG_STRICT_ACLS) &&
1355             required_features->security_descriptors &&
1356             !supported_features->security_descriptors)
1357         {
1358                 ERROR("Extraction backend does not support security descriptors!");
1359                 return WIMLIB_ERR_UNSUPPORTED;
1360         }
1361         if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS) &&
1362             required_features->security_descriptors &&
1363             !supported_features->security_descriptors)
1364                 WARNING("Ignoring Windows NT security descriptors of %lu files",
1365                         required_features->security_descriptors);
1366
1367         /* Standard UNIX metadata */
1368         if (required_features->unix_data &&
1369             (!supported_features->unix_data ||
1370              !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA)))
1371         {
1372                 if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
1373                         ERROR("Requested UNIX metadata extraction, but "
1374                               "extraction backend does not support it!");
1375                         return WIMLIB_ERR_UNSUPPORTED;
1376                 }
1377                 WARNING("Ignoring UNIX metadata (uid/gid/mode/rdev) of %lu files%"TS,
1378                         required_features->unix_data,
1379                         (supported_features->unix_data ?
1380                          T("\n          (use --unix-data mode to extract these)") : T("")));
1381         }
1382
1383         /* Linux-style extended attributes */
1384         if (required_features->linux_xattrs &&
1385             (!supported_features->linux_xattrs ||
1386              !(extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA)))
1387         {
1388                 WARNING("Ignoring Linux-style extended attributes of %lu files%"TS,
1389                         required_features->linux_xattrs,
1390                         (supported_features->linux_xattrs ?
1391                          T("\n          (use --unix-data mode to extract these)") : T("")));
1392         }
1393
1394         /* Object IDs.  */
1395         if (required_features->object_ids && !supported_features->object_ids) {
1396                 WARNING("Ignoring object IDs of %lu files",
1397                         required_features->object_ids);
1398         }
1399
1400         /* DOS Names.  */
1401         if (required_features->short_names &&
1402             !supported_features->short_names)
1403         {
1404                 if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES) {
1405                         ERROR("Extraction backend does not support DOS names!");
1406                         return WIMLIB_ERR_UNSUPPORTED;
1407                 }
1408                 WARNING("Ignoring DOS names of %lu files",
1409                         required_features->short_names);
1410         }
1411
1412         /* Timestamps.  */
1413         if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) &&
1414             !supported_features->timestamps)
1415         {
1416                 ERROR("Extraction backend does not support timestamps!");
1417                 return WIMLIB_ERR_UNSUPPORTED;
1418         }
1419
1420         return 0;
1421 }
1422
1423 static const struct apply_operations *
1424 select_apply_operations(int extract_flags)
1425 {
1426 #ifdef WITH_NTFS_3G
1427         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
1428                 return &ntfs_3g_apply_ops;
1429 #endif
1430 #ifdef __WIN32__
1431         return &win32_apply_ops;
1432 #else
1433         return &unix_apply_ops;
1434 #endif
1435 }
1436
1437 static int
1438 extract_trees(WIMStruct *wim, struct wim_dentry **trees, size_t num_trees,
1439               const tchar *target, int extract_flags)
1440 {
1441         const struct apply_operations *ops;
1442         struct apply_ctx *ctx;
1443         int ret;
1444         LIST_HEAD(dentry_list);
1445
1446         if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT) {
1447                 ret = extract_dentries_to_stdout(trees, num_trees,
1448                                                  wim->blob_table);
1449                 goto out;
1450         }
1451
1452         num_trees = remove_duplicate_trees(trees, num_trees);
1453         num_trees = remove_contained_trees(trees, num_trees);
1454
1455         ops = select_apply_operations(extract_flags);
1456
1457         if (num_trees > 1 && ops->single_tree_only) {
1458                 ERROR("Extracting multiple directory trees "
1459                       "at once is not supported in %s extraction mode!",
1460                       ops->name);
1461                 ret = WIMLIB_ERR_UNSUPPORTED;
1462                 goto out;
1463         }
1464
1465         ctx = CALLOC(1, ops->context_size);
1466         if (!ctx) {
1467                 ret = WIMLIB_ERR_NOMEM;
1468                 goto out;
1469         }
1470
1471         ctx->wim = wim;
1472         ctx->target = target;
1473         ctx->target_nchars = tstrlen(target);
1474         ctx->extract_flags = extract_flags;
1475         if (ctx->wim->progfunc) {
1476                 ctx->progfunc = ctx->wim->progfunc;
1477                 ctx->progctx = ctx->wim->progctx;
1478                 ctx->progress.extract.image = wim->current_image;
1479                 ctx->progress.extract.extract_flags = (extract_flags &
1480                                                        WIMLIB_EXTRACT_MASK_PUBLIC);
1481                 ctx->progress.extract.wimfile_name = wim->filename;
1482                 ctx->progress.extract.image_name = wimlib_get_image_name(wim,
1483                                                                          wim->current_image);
1484                 ctx->progress.extract.target = target;
1485         }
1486         INIT_LIST_HEAD(&ctx->blob_list);
1487         filedes_invalidate(&ctx->tmpfile_fd);
1488         ctx->apply_ops = ops;
1489
1490         ret = (*ops->get_supported_features)(target, &ctx->supported_features);
1491         if (ret)
1492                 goto out_cleanup;
1493
1494         build_dentry_list(&dentry_list, trees, num_trees,
1495                           !(extract_flags &
1496                             WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE));
1497
1498         dentry_list_get_features(&dentry_list, &ctx->required_features);
1499
1500         ret = do_feature_check(&ctx->required_features, &ctx->supported_features,
1501                                ctx->extract_flags);
1502         if (ret)
1503                 goto out_cleanup;
1504
1505         ret = dentry_list_calculate_extraction_names(&dentry_list, ctx);
1506         if (ret)
1507                 goto out_cleanup;
1508
1509         if (unlikely(list_empty(&dentry_list))) {
1510                 WARNING("There is nothing to extract!");
1511                 goto out_cleanup;
1512         }
1513
1514         ret = dentry_list_resolve_streams(&dentry_list, ctx);
1515         if (ret)
1516                 goto out_cleanup;
1517
1518         dentry_list_build_inode_alias_lists(&dentry_list);
1519
1520         ret = dentry_list_ref_streams(&dentry_list, ctx);
1521         if (ret)
1522                 goto out_cleanup;
1523
1524         if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
1525                 /* When extracting from a pipe, the number of bytes of data to
1526                  * extract can't be determined in the normal way (examining the
1527                  * blob table), since at this point all we have is a set of
1528                  * SHA-1 message digests of blobs that need to be extracted.
1529                  * However, we can get a reasonably accurate estimate by taking
1530                  * <TOTALBYTES> from the corresponding <IMAGE> in the WIM XML
1531                  * data.  This does assume that a full image is being extracted,
1532                  * but currently there is no API for doing otherwise.  (Also,
1533                  * subtract <HARDLINKBYTES> from this if hard links are
1534                  * supported by the extraction mode.)  */
1535                 ctx->progress.extract.total_bytes =
1536                         xml_get_image_total_bytes(wim->xml_info,
1537                                                   wim->current_image);
1538                 if (ctx->supported_features.hard_links) {
1539                         ctx->progress.extract.total_bytes -=
1540                                 xml_get_image_hard_link_bytes(wim->xml_info,
1541                                                               wim->current_image);
1542                 }
1543         }
1544
1545         ret = extract_progress(ctx,
1546                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1547                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN :
1548                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN));
1549         if (ret)
1550                 goto out_cleanup;
1551
1552         ret = (*ops->extract)(&dentry_list, ctx);
1553         if (ret)
1554                 goto out_cleanup;
1555
1556         if (ctx->progress.extract.completed_bytes <
1557             ctx->progress.extract.total_bytes)
1558         {
1559                 ctx->progress.extract.completed_bytes =
1560                         ctx->progress.extract.total_bytes;
1561                 ret = extract_progress(ctx, WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS);
1562                 if (ret)
1563                         goto out_cleanup;
1564         }
1565
1566         ret = extract_progress(ctx,
1567                                ((extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE) ?
1568                                        WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END :
1569                                        WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END));
1570 out_cleanup:
1571         destroy_blob_list(&ctx->blob_list);
1572         destroy_dentry_list(&dentry_list);
1573         FREE(ctx);
1574 out:
1575         return ret;
1576 }
1577
1578 static int
1579 mkdir_if_needed(const tchar *target)
1580 {
1581         if (!tmkdir(target, 0755))
1582                 return 0;
1583
1584         if (errno == EEXIST)
1585                 return 0;
1586
1587 #ifdef __WIN32__
1588         /* _wmkdir() fails with EACCES if called on a drive root directory.  */
1589         if (errno == EACCES)
1590                 return 0;
1591 #endif
1592
1593         ERROR_WITH_ERRNO("Failed to create directory \"%"TS"\"", target);
1594         return WIMLIB_ERR_MKDIR;
1595 }
1596
1597 /* Make sure the extraction flags make sense, and update them if needed.  */
1598 static int
1599 check_extract_flags(const WIMStruct *wim, int *extract_flags_p)
1600 {
1601         int extract_flags = *extract_flags_p;
1602
1603         /* Check for invalid flag combinations  */
1604
1605         if ((extract_flags &
1606              (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1607               WIMLIB_EXTRACT_FLAG_STRICT_ACLS)) == (WIMLIB_EXTRACT_FLAG_NO_ACLS |
1608                                                     WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
1609                 return WIMLIB_ERR_INVALID_PARAM;
1610
1611         if ((extract_flags &
1612              (WIMLIB_EXTRACT_FLAG_RPFIX |
1613               WIMLIB_EXTRACT_FLAG_NORPFIX)) == (WIMLIB_EXTRACT_FLAG_RPFIX |
1614                                                 WIMLIB_EXTRACT_FLAG_NORPFIX))
1615                 return WIMLIB_ERR_INVALID_PARAM;
1616
1617 #ifndef WITH_NTFS_3G
1618         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1619                 ERROR("wimlib was compiled without support for NTFS-3G, so\n"
1620                       "        it cannot apply a WIM image directly to an NTFS volume.");
1621                 return WIMLIB_ERR_UNSUPPORTED;
1622         }
1623 #endif
1624
1625         if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
1626 #ifdef __WIN32__
1627                 if (!wim->filename)
1628                         return WIMLIB_ERR_NO_FILENAME;
1629 #else
1630                 ERROR("WIMBoot extraction is only supported on Windows!");
1631                 return WIMLIB_ERR_UNSUPPORTED;
1632 #endif
1633         }
1634
1635         if (extract_flags & (WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS4K |
1636                              WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS8K |
1637                              WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS16K |
1638                              WIMLIB_EXTRACT_FLAG_COMPACT_LZX))
1639         {
1640         #ifdef __WIN32__
1641                 int count = 0;
1642                 count += ((extract_flags & WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS4K) != 0);
1643                 count += ((extract_flags & WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS8K) != 0);
1644                 count += ((extract_flags & WIMLIB_EXTRACT_FLAG_COMPACT_XPRESS16K) != 0);
1645                 count += ((extract_flags & WIMLIB_EXTRACT_FLAG_COMPACT_LZX) != 0);
1646                 if (count != 1) {
1647                         ERROR("Only one compression format can be specified "
1648                               "for compact-mode extraction!");
1649                         return WIMLIB_ERR_INVALID_PARAM;
1650                 }
1651                 if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
1652                         ERROR("Compact-mode extraction and WIMBoot-mode "
1653                               "extraction are mutually exclusive!");
1654                         return WIMLIB_ERR_INVALID_PARAM;
1655                 }
1656         #else
1657                 ERROR("Compact-mode extraction (System Compression) "
1658                       "is only supported on Windows!");
1659                 return WIMLIB_ERR_UNSUPPORTED;
1660         #endif
1661         }
1662
1663
1664         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
1665                               WIMLIB_EXTRACT_FLAG_NORPFIX |
1666                               WIMLIB_EXTRACT_FLAG_IMAGEMODE)) ==
1667                                         WIMLIB_EXTRACT_FLAG_IMAGEMODE)
1668         {
1669                 /* For full-image extraction, do reparse point fixups by default
1670                  * if the WIM header says they are enabled.  */
1671                 if (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
1672                         extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
1673         }
1674
1675         *extract_flags_p = extract_flags;
1676         return 0;
1677 }
1678
1679 struct append_dentry_ctx {
1680         struct wim_dentry **dentries;
1681         size_t num_dentries;
1682         size_t num_alloc_dentries;
1683 };
1684
1685 static int
1686 append_dentry_cb(struct wim_dentry *dentry, void *_ctx)
1687 {
1688         struct append_dentry_ctx *ctx = _ctx;
1689
1690         if (ctx->num_dentries == ctx->num_alloc_dentries) {
1691                 struct wim_dentry **new_dentries;
1692                 size_t new_length;
1693
1694                 new_length = max(ctx->num_alloc_dentries + 8,
1695                                  ctx->num_alloc_dentries * 3 / 2);
1696                 new_dentries = REALLOC(ctx->dentries,
1697                                        new_length * sizeof(ctx->dentries[0]));
1698                 if (new_dentries == NULL)
1699                         return WIMLIB_ERR_NOMEM;
1700                 ctx->dentries = new_dentries;
1701                 ctx->num_alloc_dentries = new_length;
1702         }
1703         ctx->dentries[ctx->num_dentries++] = dentry;
1704         return 0;
1705 }
1706
1707 /* Append dentries matched by a path which can contain wildcard characters.  */
1708 static int
1709 append_matched_dentries(WIMStruct *wim, const tchar *orig_pattern,
1710                         int extract_flags, struct append_dentry_ctx *ctx)
1711 {
1712         const size_t count_before = ctx->num_dentries;
1713         tchar *pattern;
1714         int ret;
1715
1716         pattern = canonicalize_wim_path(orig_pattern);
1717         if (!pattern)
1718                 return WIMLIB_ERR_NOMEM;
1719         ret = expand_path_pattern(wim_get_current_root_dentry(wim), pattern,
1720                                   append_dentry_cb, ctx);
1721         FREE(pattern);
1722         if (ret || ctx->num_dentries > count_before)
1723                 return ret;
1724         if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_GLOB) {
1725                 ERROR("No matches for path pattern \"%"TS"\"", orig_pattern);
1726                 return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1727         }
1728         WARNING("No matches for path pattern \"%"TS"\"", orig_pattern);
1729         return 0;
1730 }
1731
1732 static int
1733 do_wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1734                         const tchar * const *paths, size_t num_paths,
1735                         int extract_flags)
1736 {
1737         int ret;
1738         struct wim_dentry **trees;
1739         size_t num_trees;
1740
1741         if (wim == NULL || target == NULL || target[0] == T('\0') ||
1742             (num_paths != 0 && paths == NULL))
1743                 return WIMLIB_ERR_INVALID_PARAM;
1744
1745         ret = check_extract_flags(wim, &extract_flags);
1746         if (ret)
1747                 return ret;
1748
1749         ret = select_wim_image(wim, image);
1750         if (ret)
1751                 return ret;
1752
1753         ret = wim_checksum_unhashed_blobs(wim);
1754         if (ret)
1755                 return ret;
1756
1757         if ((extract_flags & (WIMLIB_EXTRACT_FLAG_NTFS |
1758                               WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE)) ==
1759             (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE))
1760         {
1761                 ret = mkdir_if_needed(target);
1762                 if (ret)
1763                         return ret;
1764         }
1765
1766         if (extract_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {
1767
1768                 struct append_dentry_ctx append_dentry_ctx = {
1769                         .dentries = NULL,
1770                         .num_dentries = 0,
1771                         .num_alloc_dentries = 0,
1772                 };
1773
1774                 for (size_t i = 0; i < num_paths; i++) {
1775                         ret = append_matched_dentries(wim, paths[i],
1776                                                       extract_flags,
1777                                                       &append_dentry_ctx);
1778                         if (ret) {
1779                                 trees = append_dentry_ctx.dentries;
1780                                 goto out_free_trees;
1781                         }
1782                 }
1783                 trees = append_dentry_ctx.dentries;
1784                 num_trees = append_dentry_ctx.num_dentries;
1785         } else {
1786                 trees = MALLOC(num_paths * sizeof(trees[0]));
1787                 if (trees == NULL)
1788                         return WIMLIB_ERR_NOMEM;
1789
1790                 for (size_t i = 0; i < num_paths; i++) {
1791
1792                         tchar *path = canonicalize_wim_path(paths[i]);
1793                         if (path == NULL) {
1794                                 ret = WIMLIB_ERR_NOMEM;
1795                                 goto out_free_trees;
1796                         }
1797
1798                         trees[i] = get_dentry(wim, path,
1799                                               WIMLIB_CASE_PLATFORM_DEFAULT);
1800                         FREE(path);
1801                         if (trees[i] == NULL) {
1802                                   ERROR("Path \"%"TS"\" does not exist "
1803                                         "in WIM image %d",
1804                                         paths[i], wim->current_image);
1805                                   ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
1806                                   goto out_free_trees;
1807                         }
1808                 }
1809                 num_trees = num_paths;
1810         }
1811
1812         if (num_trees == 0) {
1813                 ret = 0;
1814                 goto out_free_trees;
1815         }
1816
1817         ret = extract_trees(wim, trees, num_trees, target, extract_flags);
1818 out_free_trees:
1819         FREE(trees);
1820         return ret;
1821 }
1822
1823 static int
1824 extract_single_image(WIMStruct *wim, int image,
1825                      const tchar *target, int extract_flags)
1826 {
1827         const tchar *path = WIMLIB_WIM_ROOT_PATH;
1828         extract_flags |= WIMLIB_EXTRACT_FLAG_IMAGEMODE;
1829         return do_wimlib_extract_paths(wim, image, target, &path, 1, extract_flags);
1830 }
1831
1832 static const tchar * const filename_forbidden_chars =
1833 #ifdef __WIN32__
1834 T("<>:\"/\\|?*");
1835 #else
1836 T("/");
1837 #endif
1838
1839 /* This function checks if it is okay to use a WIM image's name as a directory
1840  * name.  */
1841 static bool
1842 image_name_ok_as_dir(const tchar *image_name)
1843 {
1844         return image_name && *image_name &&
1845                 !tstrpbrk(image_name, filename_forbidden_chars) &&
1846                 tstrcmp(image_name, T(".")) &&
1847                 tstrcmp(image_name, T("..")) &&
1848                 tstrlen(image_name) <= 128;
1849 }
1850
1851 /* Extracts all images from the WIM to the directory @target, with the images
1852  * placed in subdirectories named by their image names. */
1853 static int
1854 extract_all_images(WIMStruct *wim, const tchar *target, int extract_flags)
1855 {
1856         size_t output_path_len = tstrlen(target);
1857         tchar buf[output_path_len + 1 + 128 + 1];
1858         int ret;
1859         int image;
1860         const tchar *image_name;
1861
1862         if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
1863                 ERROR("Cannot extract multiple images in NTFS extraction mode.");
1864                 return WIMLIB_ERR_INVALID_PARAM;
1865         }
1866
1867         ret = mkdir_if_needed(target);
1868         if (ret)
1869                 return ret;
1870         tmemcpy(buf, target, output_path_len);
1871         buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
1872         for (image = 1; image <= wim->hdr.image_count; image++) {
1873                 image_name = wimlib_get_image_name(wim, image);
1874                 if (image_name_ok_as_dir(image_name)) {
1875                         tstrcpy(buf + output_path_len + 1, image_name);
1876                 } else {
1877                         /* Image name is empty or contains forbidden characters.
1878                          * Use image number instead. */
1879                         tsprintf(buf + output_path_len + 1, T("%d"), image);
1880                 }
1881                 ret = extract_single_image(wim, image, buf, extract_flags);
1882                 if (ret)
1883                         return ret;
1884         }
1885         return 0;
1886 }
1887
1888 static int
1889 do_wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
1890                         int extract_flags)
1891 {
1892         if (extract_flags & (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
1893                              WIMLIB_EXTRACT_FLAG_TO_STDOUT |
1894                              WIMLIB_EXTRACT_FLAG_GLOB_PATHS))
1895                 return WIMLIB_ERR_INVALID_PARAM;
1896
1897         if (image == WIMLIB_ALL_IMAGES)
1898                 return extract_all_images(wim, target, extract_flags);
1899         else
1900                 return extract_single_image(wim, image, target, extract_flags);
1901 }
1902
1903
1904 /****************************************************************************
1905  *                          Extraction API                                  *
1906  ****************************************************************************/
1907
1908 WIMLIBAPI int
1909 wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
1910                      const tchar * const *paths, size_t num_paths,
1911                      int extract_flags)
1912 {
1913         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1914                 return WIMLIB_ERR_INVALID_PARAM;
1915
1916         return do_wimlib_extract_paths(wim, image, target, paths, num_paths,
1917                                        extract_flags);
1918 }
1919
1920 WIMLIBAPI int
1921 wimlib_extract_pathlist(WIMStruct *wim, int image, const tchar *target,
1922                         const tchar *path_list_file, int extract_flags)
1923 {
1924         int ret;
1925         tchar **paths;
1926         size_t num_paths;
1927         void *mem;
1928
1929         ret = read_path_list_file(path_list_file, &paths, &num_paths, &mem);
1930         if (ret) {
1931                 ERROR("Failed to read path list file \"%"TS"\"",
1932                       path_list_file);
1933                 return ret;
1934         }
1935
1936         ret = wimlib_extract_paths(wim, image, target,
1937                                    (const tchar * const *)paths, num_paths,
1938                                    extract_flags);
1939         FREE(paths);
1940         FREE(mem);
1941         return ret;
1942 }
1943
1944 WIMLIBAPI int
1945 wimlib_extract_image_from_pipe_with_progress(int pipe_fd,
1946                                              const tchar *image_num_or_name,
1947                                              const tchar *target,
1948                                              int extract_flags,
1949                                              wimlib_progress_func_t progfunc,
1950                                              void *progctx)
1951 {
1952         int ret;
1953         WIMStruct *pwm;
1954         struct filedes *in_fd;
1955         int image;
1956         unsigned i;
1957
1958         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
1959                 return WIMLIB_ERR_INVALID_PARAM;
1960
1961         /* Read the WIM header from the pipe and get a WIMStruct to represent
1962          * the pipable WIM.  Caveats:  Unlike getting a WIMStruct with
1963          * wimlib_open_wim(), getting a WIMStruct in this way will result in an
1964          * empty blob table, no XML data read, and no filename set.  */
1965         ret = open_wim_as_WIMStruct(&pipe_fd, WIMLIB_OPEN_FLAG_FROM_PIPE, &pwm,
1966                                     progfunc, progctx);
1967         if (ret)
1968                 return ret;
1969
1970         /* Sanity check to make sure this is a pipable WIM.  */
1971         if (pwm->hdr.magic != PWM_MAGIC) {
1972                 ERROR("The WIM being read from file descriptor %d "
1973                       "is not pipable!", pipe_fd);
1974                 ret = WIMLIB_ERR_NOT_PIPABLE;
1975                 goto out_wimlib_free;
1976         }
1977
1978         /* Sanity check to make sure the first part of a pipable split WIM is
1979          * sent over the pipe first.  */
1980         if (pwm->hdr.part_number != 1) {
1981                 ERROR("The first part of the split WIM must be "
1982                       "sent over the pipe first.");
1983                 ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
1984                 goto out_wimlib_free;
1985         }
1986
1987         in_fd = &pwm->in_fd;
1988         wimlib_assert(in_fd->offset == WIM_HEADER_DISK_SIZE);
1989
1990         /* As mentioned, the WIMStruct we created from the pipe does not have
1991          * XML data yet.  Fix this by reading the extra copy of the XML data
1992          * that directly follows the header in pipable WIMs.  (Note: see
1993          * write_pipable_wim() for more details about the format of pipable
1994          * WIMs.)  */
1995         {
1996                 u8 hash[SHA1_HASH_SIZE];
1997
1998                 ret = read_pwm_blob_header(pwm, hash,
1999                                            &pwm->hdr.xml_data_reshdr, NULL);
2000                 if (ret)
2001                         goto out_wimlib_free;
2002
2003                 if (!(pwm->hdr.xml_data_reshdr.flags & WIM_RESHDR_FLAG_METADATA)) {
2004                         ERROR("Expected XML data, but found non-metadata resource.");
2005                         ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
2006                         goto out_wimlib_free;
2007                 }
2008
2009                 ret = read_wim_xml_data(pwm);
2010                 if (ret)
2011                         goto out_wimlib_free;
2012
2013                 if (xml_get_image_count(pwm->xml_info) != pwm->hdr.image_count) {
2014                         ERROR("Image count in XML data is not the same as in WIM header.");
2015                         ret = WIMLIB_ERR_IMAGE_COUNT;
2016                         goto out_wimlib_free;
2017                 }
2018         }
2019
2020         /* Get image index (this may use the XML data that was just read to
2021          * resolve an image name).  */
2022         if (image_num_or_name) {
2023                 image = wimlib_resolve_image(pwm, image_num_or_name);
2024                 if (image == WIMLIB_NO_IMAGE) {
2025                         ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
2026                               image_num_or_name);
2027                         ret = WIMLIB_ERR_INVALID_IMAGE;
2028                         goto out_wimlib_free;
2029                 } else if (image == WIMLIB_ALL_IMAGES) {
2030                         ERROR("Applying all images from a pipe is not supported!");
2031                         ret = WIMLIB_ERR_INVALID_IMAGE;
2032                         goto out_wimlib_free;
2033                 }
2034         } else {
2035                 if (pwm->hdr.image_count != 1) {
2036                         ERROR("No image was specified, but the pipable WIM "
2037                               "did not contain exactly 1 image");
2038                         ret = WIMLIB_ERR_INVALID_IMAGE;
2039                         goto out_wimlib_free;
2040                 }
2041                 image = 1;
2042         }
2043
2044         /* Load the needed metadata resource.  */
2045         for (i = 1; i <= pwm->hdr.image_count; i++) {
2046                 ret = handle_pwm_metadata_resource(pwm, i, i == image);
2047                 if (ret)
2048                         goto out_wimlib_free;
2049         }
2050         /* Extract the image.  */
2051         extract_flags |= WIMLIB_EXTRACT_FLAG_FROM_PIPE;
2052         ret = do_wimlib_extract_image(pwm, image, target, extract_flags);
2053         /* Clean up and return.  */
2054 out_wimlib_free:
2055         wimlib_free(pwm);
2056         return ret;
2057 }
2058
2059
2060 WIMLIBAPI int
2061 wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
2062                                const tchar *target, int extract_flags)
2063 {
2064         return wimlib_extract_image_from_pipe_with_progress(pipe_fd,
2065                                                             image_num_or_name,
2066                                                             target,
2067                                                             extract_flags,
2068                                                             NULL,
2069                                                             NULL);
2070 }
2071
2072 WIMLIBAPI int
2073 wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
2074                      int extract_flags)
2075 {
2076         if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
2077                 return WIMLIB_ERR_INVALID_PARAM;
2078         return do_wimlib_extract_image(wim, image, target, extract_flags);
2079 }