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