wimlib.net Git - wimlib/blob - src/modify.c

   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  * Copyright (C) 2012 Eric Biggers
  10  *
  11  * wimlib - Library for working with WIM files
  12  *
  13  * This library is free software; you can redistribute it and/or modify it under
  14  * the terms of the GNU Lesser General Public License as published by the Free
  15  * Software Foundation; either version 2.1 of the License, or (at your option) any
  16  * later version.
  17  *
  18  * This library is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
  20  * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License along
  23  * with this library; if not, write to the Free Software Foundation, Inc., 59
  24  * Temple Place, Suite 330, Boston, MA 02111-1307 USA
  25  */
  26
  27 #include "wimlib_internal.h"
  28 #include "util.h"
  29 #include "dentry.h"
  30 #include "xml.h"
  31 #include "lookup_table.h"
  32 #include <sys/stat.h>
  33 #include <dirent.h>
  34 #include <string.h>
  35 #include <errno.h>
  36
  37 /*
  38  * Recursively builds a dentry tree from a directory tree on disk, outside the
  39  * WIM file.
  40  *
  41  * @root:  A dentry that has already been created for the root of the dentry
  42  *      tree.
  43  * @source_path:  The path to the root of the tree on disk.
  44  * @root_stat:   A pointer to a `struct stat' that contains the metadata for the
  45  *      root of the tree on disk.
  46  * @lookup_table: The lookup table for the WIM file.  For each file added to the
  47  *              dentry tree being built, an entry is added to the lookup table,
  48  *              unless an identical file is already in the lookup table.  These
  49  *              lookup table entries that are added point to the file on disk.
  50  *
  51  * @return:     0 on success, nonzero on failure.  It is a failure if any of
  52  *              the files cannot be `stat'ed, or if any of the needed
  53  *              directories cannot be opened or read.  Failure to add the files
  54  *              to the WIM may still occur later when trying to actually read
  55  *              the regular files in the tree into the WIM as file resources.
  56  */
  57 static int build_dentry_tree(struct dentry *root, const char *source_path,
  58                         struct stat *root_stat, struct lookup_table* lookup_table)
  59 {
  60         int ret = 0;
  61
  62         stbuf_to_dentry(root_stat, root);
  63         if (dentry_is_directory(root)) {
  64                 /* Open the directory on disk */
  65                 DIR *dir;
  66                 struct dirent *p;
  67                 struct stat child_stat;
  68                 struct dentry *child;
  69
  70                 dir = opendir(source_path);
  71                 if (!dir) {
  72                         ERROR("Failed to open the directory `%s': %m\n",
  73                                         source_path);
  74                         return WIMLIB_ERR_OPEN;
  75                 }
  76
  77                 /* Buffer for names of files in directory. */
  78                 size_t len = strlen(source_path);
  79                 char name[len + 1 + FILENAME_MAX + 1];
  80                 memcpy(name, source_path, len);
  81                 name[len] = '/';
  82                 errno = 0;
  83
  84                 /* Create a dentry for each entry in the directory on disk, and recurse
  85                  * to any subdirectories. */
  86                 while ((p = readdir(dir)) != NULL) {
  87                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
  88                                 || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
  89                                         continue;
  90                         strcpy(name + len + 1, p->d_name);
  91                         if (stat(name, &child_stat) != 0) {
  92                                 ERROR("cannot stat `%s': %m\n", name);
  93                                 ret = WIMLIB_ERR_STAT;
  94                                 break;
  95                         }
  96                         child = new_dentry(p->d_name);
  97                         ret = build_dentry_tree(child, name, &child_stat,
  98                                                 lookup_table);
  99                         if (ret != 0)
 100                                 break;
 101                         link_dentry(child, root);
 102                 }
 103                 closedir(dir);
 104         } else {
 105                 struct lookup_table_entry *lte;
 106
 107                 /* For each non-directory, we must check to see if the file is
 108                  * in the lookup table already; if it is, we increment its
 109                  * refcnt; otherwise, we create a new lookup table entry and
 110                  * insert it. */
 111                 ret = sha1sum(source_path, root->hash);
 112                 if (ret != 0) {
 113                         ERROR("Failed to calculate sha1sum for file `%s'\n",
 114                                                 source_path);
 115                         return ret;
 116                 }
 117
 118                 lte = lookup_resource(lookup_table, root->hash);
 119                 if (lte) {
 120                         lte->refcnt++;
 121                 } else {
 122                         char *file_on_disk = STRDUP(source_path);
 123                         if (!file_on_disk) {
 124                                 ERROR("Failed to allocate memory for file "
 125                                                 "path!\n");
 126                                 return WIMLIB_ERR_NOMEM;
 127                         }
 128                         lte = new_lookup_table_entry();
 129                         if (!lte) {
 130                                 ERROR("Failed to allocate memory for new "
 131                                                 "lookup table entry!\n");
 132                                 FREE(file_on_disk);
 133                                 return WIMLIB_ERR_NOMEM;
 134                         }
 135                         lte->file_on_disk = file_on_disk;
 136                         lte->resource_entry.flags = 0;
 137                         lte->refcnt       = 1;
 138                         lte->part_number  = 1;
 139                         lte->resource_entry.original_size = root_stat->st_size;
 140                         lte->resource_entry.size = root_stat->st_size;
 141                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 142                         lookup_table_insert(lookup_table, lte);
 143                 }
 144         }
 145         return ret;
 146 }
 147
 148 struct wim_pair {
 149         WIMStruct *src_wim;
 150         WIMStruct *dest_wim;
 151 };
 152
 153 /*
 154  * This function takes in a dentry that was previously located only in image(s)
 155  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 156  * lookup table entry for this file in the lookup table of the destination WIM
 157  * file, we simply increment its reference count.  Otherwise, a new lookup table
 158  * entry is created that references the location of the file resource in the
 159  * source WIM file through the other_wim_fp field of the lookup table entry.
 160  */
 161 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 162 {
 163         WIMStruct *src_wim, *dest_wim;
 164         struct lookup_table_entry *src_table_entry;
 165         struct lookup_table_entry *dest_table_entry;
 166
 167         src_wim = ((struct wim_pair*)arg)->src_wim;
 168         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 169
 170         if (dentry_is_directory(dentry))
 171                 return 0;
 172
 173         src_table_entry = wim_lookup_resource(src_wim, dentry);
 174         if (!src_table_entry)
 175                 return 0;
 176
 177         dest_table_entry = wim_lookup_resource(dest_wim, dentry);
 178         if (dest_table_entry) {
 179                 dest_table_entry->refcnt++;
 180         } else {
 181                 dest_table_entry = new_lookup_table_entry();
 182                 if (!dest_table_entry) {
 183                         ERROR("Could not allocate lookup table entry!\n");
 184                         return WIMLIB_ERR_NOMEM;
 185                 }
 186                 dest_table_entry->other_wim_fp = src_wim->fp;
 187                 dest_table_entry->other_wim_ctype =
 188                                 wimlib_get_compression_type(src_wim);
 189                 dest_table_entry->refcnt = 1;
 190                 memcpy(&dest_table_entry->resource_entry,
 191                        &src_table_entry->resource_entry,
 192                        sizeof(struct resource_entry));
 193                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 194                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 195         }
 196         return 0;
 197 }
 198
 199 /*
 200  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 201  * file, adds an entry to the lookup table for the image metadata, updates the
 202  * image count in the header, and selects the new image.
 203  *
 204  * Does not update the XML data.
 205  *
 206  * @w:            The WIMStruct for the WIM file.
 207  * @root_dentry:  The root of the directory tree for the image.
 208  */
 209 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 210 {
 211         struct lookup_table_entry *imd_lookup_entry;
 212         struct image_metadata *imd;
 213         struct image_metadata *new_imd;
 214
 215         DEBUG("Reallocing image metadata array for image_count = %u\n",
 216                         w->hdr.image_count + 1);
 217         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 218
 219         if (!imd) {
 220                 ERROR("Failed to allocate memory for new image metadata "
 221                                 "array!\n");
 222                 return WIMLIB_ERR_NOMEM;
 223         }
 224
 225         memcpy(imd, w->image_metadata,
 226                w->hdr.image_count * sizeof(struct image_metadata));
 227
 228         imd_lookup_entry = new_lookup_table_entry();
 229         if (!imd_lookup_entry) {
 230                 ERROR("Failed to allocate new lookup table entry!\n");
 231                 FREE(imd);
 232                 return WIMLIB_ERR_NOMEM;
 233         }
 234
 235         imd_lookup_entry->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 236         randomize_byte_array(imd_lookup_entry->hash, WIM_HASH_SIZE);
 237         lookup_table_insert(w->lookup_table, imd_lookup_entry);
 238
 239         w->hdr.image_count++;
 240
 241         new_imd = &imd[w->hdr.image_count - 1];
 242
 243 #if 0
 244         init_security_data(&new_imd->security_data);
 245 #endif
 246         new_imd->lookup_table_entry = imd_lookup_entry;
 247         new_imd->modified           = true;
 248         new_imd->root_dentry        = root_dentry;
 249         w->image_metadata = imd;
 250
 251         /* Change the current image to the new one. */
 252         return wimlib_select_image(w, w->hdr.image_count);
 253 }
 254
 255 /*
 256  * Copies an image, or all the images, from a WIM file, into another WIM file.
 257  */
 258 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 259                                   int src_image,
 260                                   WIMStruct *dest_wim,
 261                                   const char *dest_name,
 262                                   const char *dest_description,
 263                                   int flags)
 264 {
 265         int boot_idx;
 266         int i;
 267         int ret;
 268         struct dentry *root;
 269         struct wim_pair wims;
 270
 271         if (src_image == WIM_ALL_IMAGES) {
 272                 if (src_wim->hdr.image_count > 1) {
 273
 274                         /* multi-image export. */
 275
 276                         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 277
 278                                 /* Specifying the boot flag on a multi-image
 279                                  * source WIM makes the boot index default to
 280                                  * the bootable image in the source WIM.  It is
 281                                  * an error if there is no such bootable image.
 282                                  * */
 283
 284                                 if (src_wim->hdr.boot_idx == 0) {
 285                                         ERROR("Cannot specify `boot' flag "
 286                                                         "when exporting multiple "
 287                                                         "images from a WIM with no "
 288                                                         "bootable images!\n");
 289                                         return WIMLIB_ERR_INVALID_PARAM;
 290                                 } else {
 291                                         boot_idx = src_wim->hdr.boot_idx;
 292                                 }
 293                         }
 294                         if (dest_name || dest_description) {
 295                                 ERROR("Image name or image description "
 296                                                 "was specified, but we are exporting "
 297                                                 "multiple images!\n");
 298                                 return WIMLIB_ERR_INVALID_PARAM;
 299                         }
 300                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 301                                 int export_flags = flags;
 302
 303                                 if (i != boot_idx)
 304                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 305
 306                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 307                                                         NULL, dest_description,
 308                                                         export_flags);
 309                                 if (ret != 0)
 310                                         return ret;
 311                         }
 312                         return 0;
 313                 } else {
 314                         src_image = 1;
 315                 }
 316         }
 317
 318         ret = wimlib_select_image(src_wim, src_image);
 319         if (ret != 0) {
 320                 ERROR("Could not select image %d from the WIM `%s' "
 321                         "to export it!\n", src_image, src_wim->filename);
 322                 return ret;
 323         }
 324
 325         if (!dest_name) {
 326                 dest_name = wimlib_get_image_name(src_wim, src_image);
 327                 DEBUG("Using name `%s' for source image %d\n",
 328                                 dest_name, src_image);
 329         }
 330
 331         DEBUG("Exporting image %d from `%s'\n", src_image, src_wim->filename);
 332
 333         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 334                 ERROR("There is already an image named `%s' "
 335                         "in the destination WIM!\n", dest_name);
 336                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 337         }
 338
 339
 340         root = wim_root_dentry(src_wim);
 341         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 342         wims.src_wim = src_wim;
 343         wims.dest_wim = dest_wim;
 344         for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 345         ret = add_new_dentry_tree(dest_wim, root);
 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 #if 0
 394         destroy_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 }