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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
  40 /*
  41  * Recursively builds a dentry tree from a directory tree on disk, outside the
  42  * WIM file.
  43  *
  44  * @root:  A dentry that has already been created for the root of the dentry
  45  *      tree.
  46  * @source_path:  The path to the root of the tree on disk.
  47  * @root_stat:   A pointer to a `struct stat' that contains the metadata for the
  48  *      root of the tree on disk.
  49  * @lookup_table: The lookup table for the WIM file.  For each file added to the
  50  *              dentry tree being built, an entry is added to the lookup table,
  51  *              unless an identical file is already in the lookup table.  These
  52  *              lookup table entries that are added point to the file on disk.
  53  *
  54  * @return:     0 on success, nonzero on failure.  It is a failure if any of
  55  *              the files cannot be `stat'ed, or if any of the needed
  56  *              directories cannot be opened or read.  Failure to add the files
  57  *              to the WIM may still occur later when trying to actually read
  58  *              the regular files in the tree into the WIM as file resources.
  59  */
  60 static int build_dentry_tree(struct dentry *root, const char *source_path,
  61                         struct stat *root_stat, struct lookup_table* lookup_table)
  62 {
  63         int ret = 0;
  64
  65         stbuf_to_dentry(root_stat, root);
  66         if (dentry_is_directory(root)) {
  67                 /* Open the directory on disk */
  68                 DIR *dir;
  69                 struct dirent *p;
  70                 struct stat child_stat;
  71                 struct dentry *child;
  72
  73                 dir = opendir(source_path);
  74                 if (!dir) {
  75                         ERROR("Failed to open the directory `%s': %m\n",
  76                                         source_path);
  77                         return WIMLIB_ERR_OPEN;
  78                 }
  79
  80                 /* Buffer for names of files in directory. */
  81                 size_t len = strlen(source_path);
  82                 char name[len + 1 + FILENAME_MAX + 1];
  83                 memcpy(name, source_path, len);
  84                 name[len] = '/';
  85                 errno = 0;
  86
  87                 /* Create a dentry for each entry in the directory on disk, and recurse
  88                  * to any subdirectories. */
  89                 while ((p = readdir(dir)) != NULL) {
  90                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
  91                                 || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
  92                                         continue;
  93                         strcpy(name + len + 1, p->d_name);
  94                         if (stat(name, &child_stat) != 0) {
  95                                 ERROR("cannot stat `%s': %m\n", name);
  96                                 ret = WIMLIB_ERR_STAT;
  97                                 break;
  98                         }
  99                         child = new_dentry(p->d_name);
 100                         ret = build_dentry_tree(child, name, &child_stat,
 101                                                 lookup_table);
 102                         if (ret != 0)
 103                                 break;
 104                         link_dentry(child, root);
 105                 }
 106                 closedir(dir);
 107         } else {
 108                 struct lookup_table_entry *lte;
 109
 110                 /* For each non-directory, we must check to see if the file is
 111                  * in the lookup table already; if it is, we increment its
 112                  * refcnt; otherwise, we create a new lookup table entry and
 113                  * insert it. */
 114                 ret = sha1sum(source_path, root->hash);
 115                 if (ret != 0) {
 116                         ERROR("Failed to calculate sha1sum for file `%s'\n",
 117                                                 source_path);
 118                         return ret;
 119                 }
 120
 121                 lte = lookup_resource(lookup_table, root->hash);
 122                 if (lte) {
 123                         lte->refcnt++;
 124                 } else {
 125                         char *file_on_disk = STRDUP(source_path);
 126                         if (!file_on_disk) {
 127                                 ERROR("Failed to allocate memory for file "
 128                                                 "path!\n");
 129                                 return WIMLIB_ERR_NOMEM;
 130                         }
 131                         lte = new_lookup_table_entry();
 132                         if (!lte) {
 133                                 ERROR("Failed to allocate memory for new "
 134                                                 "lookup table entry!\n");
 135                                 FREE(file_on_disk);
 136                                 return WIMLIB_ERR_NOMEM;
 137                         }
 138                         lte->file_on_disk = file_on_disk;
 139                         lte->resource_entry.flags = 0;
 140                         lte->refcnt       = 1;
 141                         lte->part_number  = 1;
 142                         lte->resource_entry.original_size = root_stat->st_size;
 143                         lte->resource_entry.size = root_stat->st_size;
 144                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 145                         lookup_table_insert(lookup_table, lte);
 146                 }
 147         }
 148         return ret;
 149 }
 150
 151 struct wim_pair {
 152         WIMStruct *src_wim;
 153         WIMStruct *dest_wim;
 154 };
 155
 156 /*
 157  * This function takes in a dentry that was previously located only in image(s)
 158  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 159  * lookup table entry for this file in the lookup table of the destination WIM
 160  * file, we simply increment its reference count.  Otherwise, a new lookup table
 161  * entry is created that references the location of the file resource in the
 162  * source WIM file through the other_wim_fp field of the lookup table entry.
 163  */
 164 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 165 {
 166         WIMStruct *src_wim, *dest_wim;
 167         struct lookup_table_entry *src_table_entry;
 168         struct lookup_table_entry *dest_table_entry;
 169
 170         src_wim = ((struct wim_pair*)arg)->src_wim;
 171         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 172
 173         if (dentry_is_directory(dentry))
 174                 return 0;
 175
 176         src_table_entry = wim_lookup_resource(src_wim, dentry);
 177         if (!src_table_entry)
 178                 return 0;
 179
 180         dest_table_entry = wim_lookup_resource(dest_wim, dentry);
 181         if (dest_table_entry) {
 182                 dest_table_entry->refcnt++;
 183         } else {
 184                 dest_table_entry = new_lookup_table_entry();
 185                 if (!dest_table_entry) {
 186                         ERROR("Could not allocate lookup table entry!\n");
 187                         return WIMLIB_ERR_NOMEM;
 188                 }
 189                 dest_table_entry->other_wim_fp = src_wim->fp;
 190                 dest_table_entry->other_wim_ctype =
 191                                 wimlib_get_compression_type(src_wim);
 192                 dest_table_entry->refcnt = 1;
 193                 memcpy(&dest_table_entry->resource_entry,
 194                        &src_table_entry->resource_entry,
 195                        sizeof(struct resource_entry));
 196                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 197                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 198         }
 199         return 0;
 200 }
 201
 202 /*
 203  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 204  * file, adds an entry to the lookup table for the image metadata, updates the
 205  * image count in the header, and selects the new image.
 206  *
 207  * Does not update the XML data.
 208  *
 209  * @w:            The WIMStruct for the WIM file.
 210  * @root_dentry:  The root of the directory tree for the image.
 211  */
 212 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 213 {
 214         struct lookup_table_entry *imd_lookup_entry;
 215         struct image_metadata *imd;
 216         struct image_metadata *new_imd;
 217
 218         DEBUG("Reallocing image metadata array for image_count = %u\n",
 219                         w->hdr.image_count + 1);
 220         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 221
 222         if (!imd) {
 223                 ERROR("Failed to allocate memory for new image metadata "
 224                                 "array!\n");
 225                 return WIMLIB_ERR_NOMEM;
 226         }
 227
 228         memcpy(imd, w->image_metadata,
 229                w->hdr.image_count * sizeof(struct image_metadata));
 230
 231         imd_lookup_entry = new_lookup_table_entry();
 232         if (!imd_lookup_entry) {
 233                 ERROR("Failed to allocate new lookup table entry!\n");
 234                 FREE(imd);
 235                 return WIMLIB_ERR_NOMEM;
 236         }
 237
 238         imd_lookup_entry->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 239         randomize_byte_array(imd_lookup_entry->hash, WIM_HASH_SIZE);
 240         lookup_table_insert(w->lookup_table, imd_lookup_entry);
 241
 242         w->hdr.image_count++;
 243
 244         new_imd = &imd[w->hdr.image_count - 1];
 245         new_imd->lookup_table_entry = imd_lookup_entry;
 246         new_imd->modified           = true;
 247         new_imd->root_dentry        = root_dentry;
 248         w->image_metadata = imd;
 249
 250         /* Change the current image to the new one. */
 251         return wimlib_select_image(w, w->hdr.image_count);
 252 }
 253
 254 /*
 255  * Copies an image, or all the images, from a WIM file, into another WIM file.
 256  */
 257 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 258                                   int src_image,
 259                                   WIMStruct *dest_wim,
 260                                   const char *dest_name,
 261                                   const char *dest_description,
 262                                   int flags)
 263 {
 264         int i;
 265         int ret;
 266         struct dentry *root;
 267         struct wim_pair wims;
 268
 269         if (src_image == WIM_ALL_IMAGES) {
 270                 if (src_wim->hdr.image_count > 1) {
 271
 272                         /* multi-image export. */
 273
 274                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 275                             (src_wim->hdr.boot_idx == 0))
 276                         {
 277                                 /* Specifying the boot flag on a multi-image
 278                                  * source WIM makes the boot index default to
 279                                  * the bootable image in the source WIM.  It is
 280                                  * an error if there is no such bootable image.
 281                                  * */
 282                                 ERROR("Cannot specify `boot' flag when "
 283                                       "exporting multiple images from a WIM "
 284                                       "with no bootable images!\n");
 285                                 return WIMLIB_ERR_INVALID_PARAM;
 286                         }
 287                         if (dest_name || dest_description) {
 288                                 ERROR("Image name or image description was "
 289                                       "specified, but we are exporting "
 290                                       "multiple images!\n");
 291                                 return WIMLIB_ERR_INVALID_PARAM;
 292                         }
 293                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 294                                 int export_flags = flags;
 295
 296                                 if (i != src_wim->hdr.boot_idx)
 297                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 298
 299                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 300                                                         NULL, dest_description,
 301                                                         export_flags);
 302                                 if (ret != 0)
 303                                         return ret;
 304                         }
 305                         return 0;
 306                 } else {
 307                         src_image = 1;
 308                 }
 309         }
 310
 311         ret = wimlib_select_image(src_wim, src_image);
 312         if (ret != 0) {
 313                 ERROR("Could not select image %d from the WIM `%s' "
 314                         "to export it!\n", src_image, src_wim->filename);
 315                 return ret;
 316         }
 317
 318         if (!dest_name) {
 319                 dest_name = wimlib_get_image_name(src_wim, src_image);
 320                 DEBUG("Using name `%s' for source image %d\n",
 321                                 dest_name, src_image);
 322         }
 323
 324         DEBUG("Exporting image %d from `%s'\n", src_image, src_wim->filename);
 325
 326         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 327                 ERROR("There is already an image named `%s' "
 328                         "in the destination WIM!\n", dest_name);
 329                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 330         }
 331
 332
 333         root = wim_root_dentry(src_wim);
 334         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 335         wims.src_wim = src_wim;
 336         wims.dest_wim = dest_wim;
 337         for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 338         ret = add_new_dentry_tree(dest_wim, root);
 339 #ifdef ENABLE_SECURITY_DATA
 340         struct wim_security_data *sd = wim_security_data(src_wim);
 341         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 342         new_imd->security_data = sd;
 343         if (sd)
 344                 sd->refcnt++;
 345 #endif
 346         if (ret != 0)
 347                 return ret;
 348
 349         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 350                 DEBUG("Setting boot_idx to %d\n", dest_wim->hdr.image_count);
 351                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 352         }
 353
 354         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 355                         dest_name, dest_description);
 356 }
 357
 358 /*
 359  * Deletes an image from the WIM.
 360  */
 361 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 362 {
 363         int num_images;
 364         int i;
 365         int ret;
 366         struct image_metadata *imd;
 367
 368         if (image == WIM_ALL_IMAGES) {
 369                 num_images = w->hdr.image_count;
 370                 for (i = 1; i <= num_images; i++) {
 371                         /* Always delete the first image, since by the end
 372                          * there won't be any more than that!  */
 373                         ret = wimlib_delete_image(w, 1);
 374                         if (ret != 0)
 375                                 return ret;
 376                 }
 377                 return 0;
 378         }
 379
 380         DEBUG("Deleting image %d\n", image);
 381
 382         /* Even if the dentry tree is not allocated, we must select it (and
 383          * therefore allocate it) so that we can decrement the reference counts
 384          * in the lookup table.  */
 385         ret = wimlib_select_image(w, image);
 386         if (ret != 0)
 387                 return ret;
 388
 389         /* Free the dentry tree, any lookup table entries that have their
 390          * refcnt decremented to 0, and the security data. */
 391         imd = wim_get_current_image_metadata(w);
 392         free_dentry_tree(imd->root_dentry, w->lookup_table, true);
 393 #ifdef ENABLE_SECURITY_DATA
 394         free_security_data(imd->security_data);
 395 #endif
 396
 397         /* Get rid of the lookup table entry for this image's metadata resource
 398          * */
 399         lookup_table_remove(w->lookup_table, imd->lookup_table_entry);
 400
 401         /* Get rid of the empty slot in the image metadata array. */
 402         for (i = image - 1; i < w->hdr.image_count - 1; i++)
 403                 memcpy(&w->image_metadata[i], &w->image_metadata[i + 1],
 404                                 sizeof(struct image_metadata));
 405
 406         /* Decrement the image count. */
 407         w->hdr.image_count--;
 408         if (w->hdr.image_count == 0) {
 409                 FREE(w->image_metadata);
 410                 w->image_metadata = NULL;
 411         }
 412
 413         /* Fix the boot index. */
 414         if (w->hdr.boot_idx == image)
 415                 w->hdr.boot_idx = 0;
 416         else if (w->hdr.boot_idx > image)
 417                 w->hdr.boot_idx--;
 418
 419         w->current_image = WIM_NO_IMAGE;
 420
 421         /* Remove the image from the XML information. */
 422         xml_delete_image(&w->wim_info, image);
 423         return 0;
 424 }
 425
 426 /*
 427  * Adds an image to a WIM file from a directory tree on disk.
 428  */
 429 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 430                                const char *name, const char *description,
 431                                const char *flags_element, int flags)
 432 {
 433         struct dentry *root_dentry;
 434         struct stat root_stat;
 435         int ret;
 436
 437         DEBUG("Adding dentry tree from dir `%s'\n", dir);
 438
 439         if (!name || !*name) {
 440                 ERROR("Must specify a non-empty string for the image name!\n");
 441                 return WIMLIB_ERR_INVALID_PARAM;
 442         }
 443         if (!dir) {
 444                 ERROR("Must specify the name of a directory!\n");
 445                 return WIMLIB_ERR_INVALID_PARAM;
 446         }
 447
 448         if (wimlib_image_name_in_use(w, name)) {
 449                 ERROR("There is already an image named `%s' in %s!\n",
 450                                 name, w->filename);
 451                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 452         }
 453
 454         DEBUG("Creating root dentry.\n");
 455
 456         root_dentry = new_dentry("");
 457         ret = calculate_dentry_full_path(root_dentry, NULL);
 458         if (ret != 0)
 459                 return ret;
 460         root_dentry->attributes |= WIM_FILE_ATTRIBUTE_DIRECTORY;
 461
 462         /* Construct the dentry tree from the outside filesystem. */
 463         if (stat(dir, &root_stat) != 0) {
 464                 ERROR("Failed to stat `%s': %m\n", dir);
 465                 return WIMLIB_ERR_STAT;
 466         }
 467         if (!S_ISDIR(root_stat.st_mode)) {
 468                 ERROR("`%s' is not a directory!\n", dir);
 469                 return WIMLIB_ERR_NOTDIR;
 470         }
 471         DEBUG("Building dentry tree.\n");
 472         ret = build_dentry_tree(root_dentry, dir, &root_stat,
 473                                 w->lookup_table);
 474
 475         if (ret != 0) {
 476                 ERROR("Failed to build dentry tree for `%s'!\n", dir);
 477                 goto err1;
 478         }
 479
 480         DEBUG("Recalculating full paths of dentries.\n");
 481         ret = for_dentry_in_tree(root_dentry,
 482                                  calculate_dentry_full_path, NULL);
 483         if (ret != 0) {
 484                 ERROR("Failed to calculate full paths of dentry tree.\n");
 485                 goto err1;
 486         }
 487
 488         ret = add_new_dentry_tree(w, root_dentry);
 489         if (ret != 0)
 490                 goto err1;
 491
 492         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT) {
 493                 /* Call wimlib_set_boot_idx rather than set boot_idx directly so
 494                  * that the boot metadata resource entry in the header gets
 495                  * updated. */
 496                 wimlib_set_boot_idx(w, w->hdr.image_count);
 497         }
 498
 499         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 500         if (ret != 0)
 501                 goto err1;
 502
 503         return 0;
 504 err1:
 505         free_dentry_tree(root_dentry, w->lookup_table, true);
 506         return ret;
 507 }