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   1 /*
   2  * modify.c
   3  *
   4  * Support for modifying WIM files with image-level operations (delete an image,
   5  * add an image, export an imagex from one WIM to another.)  There is nothing
   6  * here that lets you change individual files in the WIM; for that you will need
   7  * to look at the filesystem implementation in mount.c.
   8  */
   9
  10 /*
  11  * Copyright (C) 2012 Eric Biggers
  12  *
  13  * This file is part of wimlib, a library for working with WIM files.
  14  *
  15  * wimlib is free software; you can redistribute it and/or modify it under the
  16  * terms of the GNU Lesser General Public License as published by the Free
  17  * Software Foundation; either version 2.1 of the License, or (at your option)
  18  * any later version.
  19  *
  20  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  21  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  22  * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  23  * details.
  24  *
  25  * You should have received a copy of the GNU Lesser General Public License
  26  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  27  */
  28
  29 #include "wimlib_internal.h"
  30 #include "util.h"
  31 #include "sha1.h"
  32 #include "dentry.h"
  33 #include "xml.h"
  34 #include "lookup_table.h"
  35 #include <sys/stat.h>
  36 #include <dirent.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #include <unistd.h>
  40
  41 /** Private flag: Used to mark that we currently adding the root directory of
  42  * the WIM. */
  43 #define WIMLIB_ADD_IMAGE_FLAG_ROOT 0x80000000
  44
  45 static void destroy_image_metadata(struct image_metadata *imd,
  46                                    struct lookup_table *lt)
  47 {
  48         free_dentry_tree(imd->root_dentry, lt, true);
  49         free_security_data(imd->security_data);
  50         free_link_group_table(imd->lgt);
  51
  52         /* Get rid of the lookup table entry for this image's metadata resource
  53          * */
  54         lookup_table_remove(lt, imd->metadata_lte);
  55 }
  56
  57 /*
  58  * Recursively builds a dentry tree from a directory tree on disk, outside the
  59  * WIM file.
  60  *
  61  * @root:  A dentry that has already been created for the root of the dentry
  62  *         tree.
  63  * @source_path:  The path to the root of the tree on disk.
  64  * @root_stat:   A pointer to a `struct stat' that contains the metadata for the
  65  *                      root of the tree on disk.
  66  * @lookup_table: The lookup table for the WIM file.  For each file added to the
  67  *              dentry tree being built, an entry is added to the lookup table,
  68  *              unless an identical file is already in the lookup table.  These
  69  *              lookup table entries that are added point to the file on disk.
  70  *
  71  * @return:     0 on success, nonzero on failure.  It is a failure if any of
  72  *              the files cannot be `stat'ed, or if any of the needed
  73  *              directories cannot be opened or read.  Failure to add the files
  74  *              to the WIM may still occur later when trying to actually read
  75  *              the regular files in the tree into the WIM as file resources.
  76  */
  77 static int build_dentry_tree(struct dentry *root, const char *root_disk_path,
  78                              struct lookup_table* lookup_table,
  79                              int add_flags)
  80 {
  81         DEBUG("`%s'", root_disk_path);
  82         struct stat root_stbuf;
  83         int ret;
  84         int (*stat_fn)(const char *restrict, struct stat *restrict);
  85
  86         if (add_flags & WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)
  87                 stat_fn = stat;
  88         else
  89                 stat_fn = lstat;
  90
  91
  92         ret = (*stat_fn)(root_disk_path, &root_stbuf);
  93         if (ret != 0) {
  94                 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
  95                 return WIMLIB_ERR_STAT;
  96         }
  97
  98         if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
  99               !S_ISDIR(root_stbuf.st_mode)) {
 100                 ERROR("`%s' is not a directory", root_disk_path);
 101                 return WIMLIB_ERR_NOTDIR;
 102         }
 103         stbuf_to_dentry(&root_stbuf, root);
 104         add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
 105
 106         if (dentry_is_directory(root)) {
 107                 /* Open the directory on disk */
 108                 DIR *dir;
 109                 struct dirent *p;
 110                 struct dentry *child;
 111
 112                 dir = opendir(root_disk_path);
 113                 if (!dir) {
 114                         ERROR_WITH_ERRNO("Failed to open the directory `%s'",
 115                                          root_disk_path);
 116                         return WIMLIB_ERR_OPEN;
 117                 }
 118
 119                 /* Buffer for names of files in directory. */
 120                 size_t len = strlen(root_disk_path);
 121                 char name[len + 1 + FILENAME_MAX + 1];
 122                 memcpy(name, root_disk_path, len);
 123                 name[len] = '/';
 124
 125                 /* Create a dentry for each entry in the directory on disk, and recurse
 126                  * to any subdirectories. */
 127                 while ((p = readdir(dir)) != NULL) {
 128                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
 129                               || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
 130                                         continue;
 131                         strcpy(name + len + 1, p->d_name);
 132                         child = new_dentry(p->d_name);
 133                         if (!child) {
 134                                 ERROR("No memory to allocate new dentry");
 135                                 return WIMLIB_ERR_NOMEM;
 136                         }
 137                         ret = build_dentry_tree(child, name, lookup_table,
 138                                                 add_flags);
 139                         link_dentry(child, root);
 140                         if (ret != 0)
 141                                 break;
 142                 }
 143                 closedir(dir);
 144         } else if (dentry_is_symlink(root)) {
 145                 /* Archiving a symbolic link */
 146                 size_t symlink_buf_len;
 147                 char deref_name_buf[4096];
 148                 ssize_t ret = readlink(root_disk_path, deref_name_buf,
 149                                        sizeof(deref_name_buf) - 1);
 150                 if (ret == -1) {
 151                         ERROR_WITH_ERRNO("Failed to read target of "
 152                                          "symbolic link `%s'", root_disk_path);
 153                         return WIMLIB_ERR_STAT;
 154                 }
 155                 deref_name_buf[ret] = '\0';
 156                 DEBUG("Read symlink `%s'", deref_name_buf);
 157                 void *symlink_buf = make_symlink_reparse_data_buf(deref_name_buf,
 158                                                                   &symlink_buf_len);
 159                 if (!symlink_buf)
 160                         return WIMLIB_ERR_NOMEM;
 161                 DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
 162                                 symlink_buf_len, ret);
 163
 164                 u8 symlink_buf_hash[WIM_HASH_SIZE];
 165                 sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
 166
 167                 ret = dentry_set_symlink_buf(root, symlink_buf_hash);
 168
 169                 if (ret != 0) {
 170                         FREE(symlink_buf);
 171                         return ret;
 172                 }
 173                 DEBUG("Created symlink buf");
 174
 175                 struct lookup_table_entry *lte;
 176                 struct lookup_table_entry *existing_lte;
 177
 178                 existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
 179                 if (existing_lte) {
 180                         existing_lte->refcnt++;
 181                 } else {
 182                         DEBUG("Creating new lookup table entry");
 183                         lte = new_lookup_table_entry();
 184                         if (!lte) {
 185                                 FREE(symlink_buf);
 186                                 return WIMLIB_ERR_NOMEM;
 187                         }
 188                         lte->symlink_buf = symlink_buf;
 189                         lte->resource_entry.original_size = symlink_buf_len;
 190                         lte->resource_entry.size = symlink_buf_len;
 191                         lte->is_symlink = true;
 192                         memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
 193                         lookup_table_insert(lookup_table, lte);
 194                 }
 195         } else {
 196                 /* Regular file */
 197                 struct lookup_table_entry *lte;
 198
 199                 /* For each regular file, we must check to see if the file is in
 200                  * the lookup table already; if it is, we increment its refcnt;
 201                  * otherwise, we create a new lookup table entry and insert it.
 202                  * */
 203                 ret = sha1sum(root_disk_path, root->hash);
 204                 if (ret != 0)
 205                         return ret;
 206
 207                 lte = __lookup_resource(lookup_table, root->hash);
 208                 if (lte) {
 209                         lte->refcnt++;
 210                 } else {
 211                         char *file_on_disk = STRDUP(root_disk_path);
 212                         if (!file_on_disk) {
 213                                 ERROR("Failed to allocate memory for file path");
 214                                 return WIMLIB_ERR_NOMEM;
 215                         }
 216                         lte = new_lookup_table_entry();
 217                         if (!lte) {
 218                                 FREE(file_on_disk);
 219                                 return WIMLIB_ERR_NOMEM;
 220                         }
 221                         lte->file_on_disk = file_on_disk;
 222                         lte->resource_entry.original_size = root_stbuf.st_size;
 223                         lte->resource_entry.size = root_stbuf.st_size;
 224                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 225                         lookup_table_insert(lookup_table, lte);
 226                 }
 227         }
 228         return ret;
 229 }
 230
 231 struct wim_pair {
 232         WIMStruct *src_wim;
 233         WIMStruct *dest_wim;
 234 };
 235
 236 /*
 237  * This function takes in a dentry that was previously located only in image(s)
 238  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 239  * lookup table entry for this file in the lookup table of the destination WIM
 240  * file, we simply increment its reference count.  Otherwise, a new lookup table
 241  * entry is created that references the location of the file resource in the
 242  * source WIM file through the other_wim_fp field of the lookup table entry.
 243  */
 244 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 245 {
 246         WIMStruct *src_wim, *dest_wim;
 247         struct lookup_table_entry *src_table_entry;
 248         struct lookup_table_entry *dest_table_entry;
 249
 250         src_wim = ((struct wim_pair*)arg)->src_wim;
 251         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 252
 253         if (dentry_is_directory(dentry))
 254                 return 0;
 255
 256         /* XXX ADS */
 257         src_table_entry = __lookup_resource(src_wim->lookup_table, dentry->hash);
 258         if (!src_table_entry)
 259                 return 0;
 260
 261         /* XXX ADS */
 262         dest_table_entry = __lookup_resource(dest_wim->lookup_table, dentry->hash);
 263         if (dest_table_entry) {
 264                 dest_table_entry->refcnt++;
 265         } else {
 266                 dest_table_entry = new_lookup_table_entry();
 267                 if (!dest_table_entry)
 268                         return WIMLIB_ERR_NOMEM;
 269                 dest_table_entry->other_wim_fp = src_wim->fp;
 270                 dest_table_entry->other_wim_ctype =
 271                                 wimlib_get_compression_type(src_wim);
 272                 dest_table_entry->refcnt = 1;
 273                 memcpy(&dest_table_entry->resource_entry,
 274                        &src_table_entry->resource_entry,
 275                        sizeof(struct resource_entry));
 276                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 277                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 278         }
 279         return 0;
 280 }
 281
 282 /*
 283  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 284  * file, adds an entry to the lookup table for the image metadata, updates the
 285  * image count in the header, and selects the new image.
 286  *
 287  * Does not update the XML data.
 288  *
 289  * @w:            The WIMStruct for the WIM file.
 290  * @root_dentry:  The root of the directory tree for the image.
 291  */
 292 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 293 {
 294         struct lookup_table_entry *metadata_lte;
 295         struct image_metadata *imd;
 296         struct image_metadata *new_imd;
 297         struct wim_security_data *sd;
 298
 299         DEBUG("Reallocating image metadata array for image_count = %u",
 300               w->hdr.image_count + 1);
 301         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 302
 303         if (!imd) {
 304                 ERROR("Failed to allocate memory for new image metadata array");
 305                 return WIMLIB_ERR_NOMEM;
 306         }
 307
 308         memcpy(imd, w->image_metadata,
 309                w->hdr.image_count * sizeof(struct image_metadata));
 310
 311         metadata_lte = new_lookup_table_entry();
 312         if (!metadata_lte)
 313                 goto out_free_imd;
 314         sd = CALLOC(1, sizeof(struct wim_security_data));
 315         if (!sd)
 316                 goto out_free_metadata_lte;
 317         sd->refcnt = 1;
 318         sd->total_length = 8;
 319
 320         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 321         randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
 322         lookup_table_insert(w->lookup_table, metadata_lte);
 323
 324         w->hdr.image_count++;
 325
 326         new_imd                 = &imd[w->hdr.image_count - 1];
 327         new_imd->metadata_lte   = metadata_lte;
 328         new_imd->modified       = true;
 329         new_imd->root_dentry    = root_dentry;
 330         new_imd->security_data  = sd;
 331         FREE(w->image_metadata);
 332         w->image_metadata       = imd;
 333
 334         /* Change the current image to the new one. */
 335         return wimlib_select_image(w, w->hdr.image_count);
 336 out_free_metadata_lte:
 337         FREE(metadata_lte);
 338 out_free_imd:
 339         FREE(imd);
 340         return WIMLIB_ERR_NOMEM;
 341
 342 }
 343
 344 /*
 345  * Copies an image, or all the images, from a WIM file, into another WIM file.
 346  */
 347 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 348                                   int src_image,
 349                                   WIMStruct *dest_wim,
 350                                   const char *dest_name,
 351                                   const char *dest_description,
 352                                   int flags)
 353 {
 354         int i;
 355         int ret;
 356         struct dentry *root;
 357         struct wim_pair wims;
 358
 359         if (src_image == WIM_ALL_IMAGES) {
 360                 if (src_wim->hdr.image_count > 1) {
 361
 362                         /* multi-image export. */
 363
 364                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 365                               (src_wim->hdr.boot_idx == 0))
 366                         {
 367                                 /* Specifying the boot flag on a multi-image
 368                                  * source WIM makes the boot index default to
 369                                  * the bootable image in the source WIM.  It is
 370                                  * an error if there is no such bootable image.
 371                                  * */
 372                                 ERROR("Cannot specify `boot' flag when "
 373                                       "exporting multiple images from a WIM "
 374                                       "with no bootable images");
 375                                 return WIMLIB_ERR_INVALID_PARAM;
 376                         }
 377                         if (dest_name || dest_description) {
 378                                 ERROR("Image name or image description was "
 379                                       "specified, but we are exporting "
 380                                       "multiple images");
 381                                 return WIMLIB_ERR_INVALID_PARAM;
 382                         }
 383                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 384                                 int export_flags = flags;
 385
 386                                 if (i != src_wim->hdr.boot_idx)
 387                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 388
 389                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 390                                                           NULL,
 391                                                           dest_description,
 392                                                           export_flags);
 393                                 if (ret != 0)
 394                                         return ret;
 395                         }
 396                         return 0;
 397                 } else {
 398                         src_image = 1;
 399                 }
 400         }
 401
 402         ret = wimlib_select_image(src_wim, src_image);
 403         if (ret != 0) {
 404                 ERROR("Could not select image %d from the WIM `%s' "
 405                       "to export it", src_image, src_wim->filename);
 406                 return ret;
 407         }
 408
 409         if (!dest_name) {
 410                 dest_name = wimlib_get_image_name(src_wim, src_image);
 411                 DEBUG("Using name `%s' for source image %d",
 412                       dest_name, src_image);
 413         }
 414
 415         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 416
 417         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 418                 ERROR("There is already an image named `%s' in the "
 419                       "destination WIM", dest_name);
 420                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 421         }
 422
 423
 424         /* Cleaning up here on failure would be hard.  For example, we could
 425          * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
 426          * leaving the lookup table entries in the destination WIM in an
 427          * inconsistent state.  Until these issues can be resolved,
 428          * wimlib_export_image() is documented as leaving dest_wim is an
 429          * indeterminate state.  */
 430         root = wim_root_dentry(src_wim);
 431         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 432         wims.src_wim = src_wim;
 433         wims.dest_wim = dest_wim;
 434         ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 435         if (ret != 0)
 436                 return ret;
 437         ret = add_new_dentry_tree(dest_wim, root);
 438         if (ret != 0)
 439                 return ret;
 440         /* Bring over old security data */
 441         struct wim_security_data *sd = wim_security_data(src_wim);
 442         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 443         wimlib_assert(sd);
 444         free_security_data(new_imd->security_data);
 445         new_imd->security_data = sd;
 446         sd->refcnt++;
 447
 448         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 449                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 450                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 451         }
 452
 453         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 454                                 dest_name, dest_description);
 455 }
 456
 457 /*
 458  * Deletes an image from the WIM.
 459  */
 460 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 461 {
 462         int num_images;
 463         int i;
 464         int ret;
 465
 466         if (image == WIM_ALL_IMAGES) {
 467                 num_images = w->hdr.image_count;
 468                 for (i = 1; i <= num_images; i++) {
 469                         /* Always delete the first image, since by the end
 470                          * there won't be any more than that!  */
 471                         ret = wimlib_delete_image(w, 1);
 472                         if (ret != 0)
 473                                 return ret;
 474                 }
 475                 return 0;
 476         }
 477
 478         DEBUG("Deleting image %d", image);
 479
 480         /* Even if the dentry tree is not allocated, we must select it (and
 481          * therefore allocate it) so that we can decrement the reference counts
 482          * in the lookup table.  */
 483         ret = wimlib_select_image(w, image);
 484         if (ret != 0)
 485                 return ret;
 486
 487         /* Free the dentry tree, any lookup table entries that have their
 488          * refcnt decremented to 0, and the security data. */
 489         destroy_image_metadata(wim_get_current_image_metadata(w),
 490                                w->lookup_table);
 491
 492         /* Get rid of the empty slot in the image metadata array. */
 493         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 494                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 495
 496         /* Decrement the image count. */
 497         if (--w->hdr.image_count == 0) {
 498                 FREE(w->image_metadata);
 499                 w->image_metadata = NULL;
 500         }
 501
 502         /* Fix the boot index. */
 503         if (w->hdr.boot_idx == image)
 504                 w->hdr.boot_idx = 0;
 505         else if (w->hdr.boot_idx > image)
 506                 w->hdr.boot_idx--;
 507
 508         w->current_image = WIM_NO_IMAGE;
 509
 510         /* Remove the image from the XML information. */
 511         xml_delete_image(&w->wim_info, image);
 512         return 0;
 513 }
 514
 515 /*
 516  * Adds an image to a WIM file from a directory tree on disk.
 517  */
 518 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 519                                const char *name, const char *description,
 520                                const char *flags_element, int flags)
 521 {
 522         struct dentry *root_dentry;
 523         struct stat root_stat;
 524         struct image_metadata *imd;
 525         int ret;
 526
 527         DEBUG("Adding dentry tree from dir `%s'.", dir);
 528
 529         if (!name || !*name) {
 530                 ERROR("Must specify a non-empty string for the image name");
 531                 return WIMLIB_ERR_INVALID_PARAM;
 532         }
 533         if (!dir) {
 534                 ERROR("Must specify the name of a directory");
 535                 return WIMLIB_ERR_INVALID_PARAM;
 536         }
 537
 538         if (wimlib_image_name_in_use(w, name)) {
 539                 ERROR("There is already an image named \"%s\" in `%s'",
 540                       name, w->filename);
 541                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 542         }
 543
 544         DEBUG("Creating root dentry.");
 545
 546         root_dentry = new_dentry("");
 547         if (!root_dentry)
 548                 return WIMLIB_ERR_NOMEM;
 549         ret = calculate_dentry_full_path(root_dentry, NULL);
 550
 551         if (ret != 0)
 552                 goto out_free_dentry_tree;
 553
 554         root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
 555
 556         DEBUG("Building dentry tree.");
 557         ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
 558                                 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
 559
 560         if (ret != 0) {
 561                 ERROR("Failed to build dentry tree for `%s'", dir);
 562                 goto out_free_dentry_tree;
 563         }
 564
 565         DEBUG("Recalculating full paths of dentries.");
 566         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 567         if (ret != 0)
 568                 goto out_free_dentry_tree;
 569
 570         ret = add_new_dentry_tree(w, root_dentry);
 571         if (ret != 0)
 572                 goto out_free_dentry_tree;
 573
 574         ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
 575                                  &w->image_metadata[w->hdr.image_count - 1].lgt);
 576         if (ret != 0)
 577                 goto out_destroy_imd;
 578         assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
 579
 580         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 581                 wimlib_set_boot_idx(w, w->hdr.image_count);
 582
 583         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 584         if (ret != 0)
 585                 goto out_destroy_imd;
 586
 587         return 0;
 588 out_destroy_imd:
 589         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 590                                w->lookup_table);
 591         return ret;
 592 out_free_dentry_tree:
 593         free_dentry_tree(root_dentry, w->lookup_table, true);
 594         return ret;
 595 }