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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                 /* Regular file */
 196                 struct lookup_table_entry *lte;
 197
 198                 /* For each regular file, we must check to see if the file is in
 199                  * the lookup table already; if it is, we increment its refcnt;
 200                  * otherwise, we create a new lookup table entry and insert it.
 201                  * */
 202                 ret = sha1sum(root_disk_path, root->hash);
 203                 if (ret != 0)
 204                         return ret;
 205
 206                 lte = __lookup_resource(lookup_table, root->hash);
 207                 if (lte) {
 208                         lte->refcnt++;
 209                 } else {
 210                         char *file_on_disk = STRDUP(root_disk_path);
 211                         if (!file_on_disk) {
 212                                 ERROR("Failed to allocate memory for file path");
 213                                 return WIMLIB_ERR_NOMEM;
 214                         }
 215                         lte = new_lookup_table_entry();
 216                         if (!lte) {
 217                                 FREE(file_on_disk);
 218                                 return WIMLIB_ERR_NOMEM;
 219                         }
 220                         lte->file_on_disk = file_on_disk;
 221                         lte->resource_entry.original_size = root_stbuf.st_size;
 222                         lte->resource_entry.size = root_stbuf.st_size;
 223                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 224                         lookup_table_insert(lookup_table, lte);
 225                 }
 226         }
 227         return ret;
 228 }
 229
 230 struct wim_pair {
 231         WIMStruct *src_wim;
 232         WIMStruct *dest_wim;
 233 };
 234
 235 /*
 236  * This function takes in a dentry that was previously located only in image(s)
 237  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 238  * lookup table entry for this file in the lookup table of the destination WIM
 239  * file, we simply increment its reference count.  Otherwise, a new lookup table
 240  * entry is created that references the location of the file resource in the
 241  * source WIM file through the other_wim_fp field of the lookup table entry.
 242  */
 243 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 244 {
 245         WIMStruct *src_wim, *dest_wim;
 246         struct lookup_table_entry *src_table_entry;
 247         struct lookup_table_entry *dest_table_entry;
 248
 249         src_wim = ((struct wim_pair*)arg)->src_wim;
 250         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 251
 252         if (dentry_is_directory(dentry))
 253                 return 0;
 254
 255         src_table_entry = wim_lookup_resource(src_wim, dentry);
 256         if (!src_table_entry)
 257                 return 0;
 258
 259         dest_table_entry = wim_lookup_resource(dest_wim, dentry);
 260         if (dest_table_entry) {
 261                 dest_table_entry->refcnt++;
 262         } else {
 263                 dest_table_entry = new_lookup_table_entry();
 264                 if (!dest_table_entry)
 265                         return WIMLIB_ERR_NOMEM;
 266                 dest_table_entry->other_wim_fp = src_wim->fp;
 267                 dest_table_entry->other_wim_ctype =
 268                                 wimlib_get_compression_type(src_wim);
 269                 dest_table_entry->refcnt = 1;
 270                 memcpy(&dest_table_entry->resource_entry,
 271                        &src_table_entry->resource_entry,
 272                        sizeof(struct resource_entry));
 273                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 274                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 275         }
 276         return 0;
 277 }
 278
 279 /*
 280  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 281  * file, adds an entry to the lookup table for the image metadata, updates the
 282  * image count in the header, and selects the new image.
 283  *
 284  * Does not update the XML data.
 285  *
 286  * @w:            The WIMStruct for the WIM file.
 287  * @root_dentry:  The root of the directory tree for the image.
 288  */
 289 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 290 {
 291         struct lookup_table_entry *metadata_lte;
 292         struct image_metadata *imd;
 293         struct image_metadata *new_imd;
 294         struct wim_security_data *sd;
 295
 296         DEBUG("Reallocating image metadata array for image_count = %u",
 297               w->hdr.image_count + 1);
 298         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 299
 300         if (!imd) {
 301                 ERROR("Failed to allocate memory for new image metadata array");
 302                 return WIMLIB_ERR_NOMEM;
 303         }
 304
 305         memcpy(imd, w->image_metadata,
 306                w->hdr.image_count * sizeof(struct image_metadata));
 307
 308         metadata_lte = new_lookup_table_entry();
 309         if (!metadata_lte)
 310                 goto out_free_imd;
 311         sd = CALLOC(1, sizeof(struct wim_security_data));
 312         if (!sd)
 313                 goto out_free_metadata_lte;
 314         sd->refcnt = 1;
 315         sd->total_length = 8;
 316
 317         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 318         randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
 319         lookup_table_insert(w->lookup_table, metadata_lte);
 320
 321         w->hdr.image_count++;
 322
 323         new_imd                 = &imd[w->hdr.image_count - 1];
 324         new_imd->metadata_lte   = metadata_lte;
 325         new_imd->modified       = true;
 326         new_imd->root_dentry    = root_dentry;
 327         new_imd->security_data  = sd;
 328         FREE(w->image_metadata);
 329         w->image_metadata       = imd;
 330
 331         /* Change the current image to the new one. */
 332         return wimlib_select_image(w, w->hdr.image_count);
 333 out_free_metadata_lte:
 334         FREE(metadata_lte);
 335 out_free_imd:
 336         FREE(imd);
 337         return WIMLIB_ERR_NOMEM;
 338
 339 }
 340
 341 /*
 342  * Copies an image, or all the images, from a WIM file, into another WIM file.
 343  */
 344 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 345                                   int src_image,
 346                                   WIMStruct *dest_wim,
 347                                   const char *dest_name,
 348                                   const char *dest_description,
 349                                   int flags)
 350 {
 351         int i;
 352         int ret;
 353         struct dentry *root;
 354         struct wim_pair wims;
 355
 356         if (src_image == WIM_ALL_IMAGES) {
 357                 if (src_wim->hdr.image_count > 1) {
 358
 359                         /* multi-image export. */
 360
 361                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 362                               (src_wim->hdr.boot_idx == 0))
 363                         {
 364                                 /* Specifying the boot flag on a multi-image
 365                                  * source WIM makes the boot index default to
 366                                  * the bootable image in the source WIM.  It is
 367                                  * an error if there is no such bootable image.
 368                                  * */
 369                                 ERROR("Cannot specify `boot' flag when "
 370                                       "exporting multiple images from a WIM "
 371                                       "with no bootable images");
 372                                 return WIMLIB_ERR_INVALID_PARAM;
 373                         }
 374                         if (dest_name || dest_description) {
 375                                 ERROR("Image name or image description was "
 376                                       "specified, but we are exporting "
 377                                       "multiple images");
 378                                 return WIMLIB_ERR_INVALID_PARAM;
 379                         }
 380                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 381                                 int export_flags = flags;
 382
 383                                 if (i != src_wim->hdr.boot_idx)
 384                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 385
 386                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 387                                                           NULL,
 388                                                           dest_description,
 389                                                           export_flags);
 390                                 if (ret != 0)
 391                                         return ret;
 392                         }
 393                         return 0;
 394                 } else {
 395                         src_image = 1;
 396                 }
 397         }
 398
 399         ret = wimlib_select_image(src_wim, src_image);
 400         if (ret != 0) {
 401                 ERROR("Could not select image %d from the WIM `%s' "
 402                       "to export it", src_image, src_wim->filename);
 403                 return ret;
 404         }
 405
 406         if (!dest_name) {
 407                 dest_name = wimlib_get_image_name(src_wim, src_image);
 408                 DEBUG("Using name `%s' for source image %d",
 409                       dest_name, src_image);
 410         }
 411
 412         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 413
 414         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 415                 ERROR("There is already an image named `%s' in the "
 416                       "destination WIM", dest_name);
 417                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 418         }
 419
 420
 421         /* Cleaning up here on failure would be hard.  For example, we could
 422          * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
 423          * leaving the lookup table entries in the destination WIM in an
 424          * inconsistent state.  Until these issues can be resolved,
 425          * wimlib_export_image() is documented as leaving dest_wim is an
 426          * indeterminate state.  */
 427         root = wim_root_dentry(src_wim);
 428         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 429         wims.src_wim = src_wim;
 430         wims.dest_wim = dest_wim;
 431         ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 432         if (ret != 0)
 433                 return ret;
 434         ret = add_new_dentry_tree(dest_wim, root);
 435         if (ret != 0)
 436                 return ret;
 437         /* Bring over old security data */
 438         struct wim_security_data *sd = wim_security_data(src_wim);
 439         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 440         wimlib_assert(sd);
 441         free_security_data(new_imd->security_data);
 442         new_imd->security_data = sd;
 443         sd->refcnt++;
 444
 445         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 446                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 447                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 448         }
 449
 450         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 451                                 dest_name, dest_description);
 452 }
 453
 454 /*
 455  * Deletes an image from the WIM.
 456  */
 457 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 458 {
 459         int num_images;
 460         int i;
 461         int ret;
 462
 463         if (image == WIM_ALL_IMAGES) {
 464                 num_images = w->hdr.image_count;
 465                 for (i = 1; i <= num_images; i++) {
 466                         /* Always delete the first image, since by the end
 467                          * there won't be any more than that!  */
 468                         ret = wimlib_delete_image(w, 1);
 469                         if (ret != 0)
 470                                 return ret;
 471                 }
 472                 return 0;
 473         }
 474
 475         DEBUG("Deleting image %d", image);
 476
 477         /* Even if the dentry tree is not allocated, we must select it (and
 478          * therefore allocate it) so that we can decrement the reference counts
 479          * in the lookup table.  */
 480         ret = wimlib_select_image(w, image);
 481         if (ret != 0)
 482                 return ret;
 483
 484         /* Free the dentry tree, any lookup table entries that have their
 485          * refcnt decremented to 0, and the security data. */
 486         destroy_image_metadata(wim_get_current_image_metadata(w),
 487                                w->lookup_table);
 488
 489         /* Get rid of the empty slot in the image metadata array. */
 490         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 491                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 492
 493         /* Decrement the image count. */
 494         if (--w->hdr.image_count == 0) {
 495                 FREE(w->image_metadata);
 496                 w->image_metadata = NULL;
 497         }
 498
 499         /* Fix the boot index. */
 500         if (w->hdr.boot_idx == image)
 501                 w->hdr.boot_idx = 0;
 502         else if (w->hdr.boot_idx > image)
 503                 w->hdr.boot_idx--;
 504
 505         w->current_image = WIM_NO_IMAGE;
 506
 507         /* Remove the image from the XML information. */
 508         xml_delete_image(&w->wim_info, image);
 509         return 0;
 510 }
 511
 512 /*
 513  * Adds an image to a WIM file from a directory tree on disk.
 514  */
 515 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 516                                const char *name, const char *description,
 517                                const char *flags_element, int flags)
 518 {
 519         struct dentry *root_dentry;
 520         struct stat root_stat;
 521         struct image_metadata *imd;
 522         int ret;
 523
 524         DEBUG("Adding dentry tree from dir `%s'.", dir);
 525
 526         if (!name || !*name) {
 527                 ERROR("Must specify a non-empty string for the image name");
 528                 return WIMLIB_ERR_INVALID_PARAM;
 529         }
 530         if (!dir) {
 531                 ERROR("Must specify the name of a directory");
 532                 return WIMLIB_ERR_INVALID_PARAM;
 533         }
 534
 535         if (wimlib_image_name_in_use(w, name)) {
 536                 ERROR("There is already an image named \"%s\" in `%s'",
 537                       name, w->filename);
 538                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 539         }
 540
 541         DEBUG("Creating root dentry.");
 542
 543         root_dentry = new_dentry("");
 544         if (!root_dentry)
 545                 return WIMLIB_ERR_NOMEM;
 546         ret = calculate_dentry_full_path(root_dentry, NULL);
 547
 548         if (ret != 0)
 549                 goto out_free_dentry_tree;
 550
 551         root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
 552
 553         DEBUG("Building dentry tree.");
 554         ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
 555                                 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
 556
 557         if (ret != 0) {
 558                 ERROR("Failed to build dentry tree for `%s'", dir);
 559                 goto out_free_dentry_tree;
 560         }
 561
 562         DEBUG("Recalculating full paths of dentries.");
 563         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 564         if (ret != 0)
 565                 goto out_free_dentry_tree;
 566
 567         ret = add_new_dentry_tree(w, root_dentry);
 568         if (ret != 0)
 569                 goto out_free_dentry_tree;
 570
 571         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 572                 wimlib_set_boot_idx(w, w->hdr.image_count);
 573
 574         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 575         if (ret != 0)
 576                 goto out_destroy_imd;
 577
 578         return 0;
 579 out_destroy_imd:
 580         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 581                                w->lookup_table);
 582         return ret;
 583 out_free_dentry_tree:
 584         free_dentry_tree(root_dentry, w->lookup_table, true);
 585         return ret;
 586 }