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         new_imd->lookup_table_entry = imd_lookup_entry;
 243         new_imd->modified           = true;
 244         new_imd->root_dentry        = root_dentry;
 245         w->image_metadata = imd;
 246
 247         /* Change the current image to the new one. */
 248         return wimlib_select_image(w, w->hdr.image_count);
 249 }
 250
 251 /*
 252  * Copies an image, or all the images, from a WIM file, into another WIM file.
 253  */
 254 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 255                                   int src_image,
 256                                   WIMStruct *dest_wim,
 257                                   const char *dest_name,
 258                                   const char *dest_description,
 259                                   int flags)
 260 {
 261         int boot_idx;
 262         int i;
 263         int ret;
 264         struct dentry *root;
 265         struct wim_pair wims;
 266
 267         if (src_image == WIM_ALL_IMAGES) {
 268                 if (src_wim->hdr.image_count > 1) {
 269
 270                         /* multi-image export. */
 271
 272                         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 273
 274                                 /* Specifying the boot flag on a multi-image
 275                                  * source WIM makes the boot index default to
 276                                  * the bootable image in the source WIM.  It is
 277                                  * an error if there is no such bootable image.
 278                                  * */
 279
 280                                 if (src_wim->hdr.boot_idx == 0) {
 281                                         ERROR("Cannot specify `boot' flag "
 282                                                         "when exporting multiple "
 283                                                         "images from a WIM with no "
 284                                                         "bootable images!\n");
 285                                         return WIMLIB_ERR_INVALID_PARAM;
 286                                 } else {
 287                                         boot_idx = src_wim->hdr.boot_idx;
 288                                 }
 289                         }
 290                         if (dest_name || dest_description) {
 291                                 ERROR("Image name or image description "
 292                                                 "was specified, but we are exporting "
 293                                                 "multiple images!\n");
 294                                 return WIMLIB_ERR_INVALID_PARAM;
 295                         }
 296                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 297                                 int export_flags = flags;
 298
 299                                 if (i != boot_idx)
 300                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 301
 302                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 303                                                         NULL, dest_description,
 304                                                         export_flags);
 305                                 if (ret != 0)
 306                                         return ret;
 307                         }
 308                         return 0;
 309                 } else {
 310                         src_image = 1;
 311                 }
 312         }
 313
 314         ret = wimlib_select_image(src_wim, src_image);
 315         if (ret != 0) {
 316                 ERROR("Could not select image %d from the WIM `%s' "
 317                         "to export it!\n", src_image, src_wim->filename);
 318                 return ret;
 319         }
 320
 321         if (!dest_name) {
 322                 dest_name = wimlib_get_image_name(src_wim, src_image);
 323                 DEBUG("Using name `%s' for source image %d\n",
 324                                 dest_name, src_image);
 325         }
 326
 327         DEBUG("Exporting image %d from `%s'\n", src_image, src_wim->filename);
 328
 329         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 330                 ERROR("There is already an image named `%s' "
 331                         "in the destination WIM!\n", dest_name);
 332                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 333         }
 334
 335
 336         root = wim_root_dentry(src_wim);
 337         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 338         wims.src_wim = src_wim;
 339         wims.dest_wim = dest_wim;
 340         for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 341         ret = add_new_dentry_tree(dest_wim, root);
 342 #ifdef ENABLE_SECURITY_DATA
 343         struct wim_security_data *sd = wim_security_data(src_wim);
 344         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 345         new_imd->security_data = sd;
 346         if (sd)
 347                 sd->refcnt++;
 348 #endif
 349         if (ret != 0)
 350                 return ret;
 351
 352         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 353                 DEBUG("Setting boot_idx to %d\n", dest_wim->hdr.image_count);
 354                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 355         }
 356
 357         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 358                         dest_name, dest_description);
 359 }
 360
 361 /*
 362  * Deletes an image from the WIM.
 363  */
 364 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 365 {
 366         int num_images;
 367         int i;
 368         int ret;
 369         struct image_metadata *imd;
 370
 371         if (image == WIM_ALL_IMAGES) {
 372                 num_images = w->hdr.image_count;
 373                 for (i = 1; i <= num_images; i++) {
 374                         /* Always delete the first image, since by the end
 375                          * there won't be any more than that!  */
 376                         ret = wimlib_delete_image(w, 1);
 377                         if (ret != 0)
 378                                 return ret;
 379                 }
 380                 return 0;
 381         }
 382
 383         DEBUG("Deleting image %d\n", image);
 384
 385         /* Even if the dentry tree is not allocated, we must select it (and
 386          * therefore allocate it) so that we can decrement the reference counts
 387          * in the lookup table.  */
 388         ret = wimlib_select_image(w, image);
 389         if (ret != 0)
 390                 return ret;
 391
 392         /* Free the dentry tree, any lookup table entries that have their
 393          * refcnt decremented to 0, and the security data. */
 394         imd = wim_get_current_image_metadata(w);
 395         free_dentry_tree(imd->root_dentry, w->lookup_table, true);
 396 #ifdef ENABLE_SECURITY_DATA
 397         free_security_data(imd->security_data);
 398 #endif
 399
 400         /* Get rid of the lookup table entry for this image's metadata resource
 401          * */
 402         lookup_table_remove(w->lookup_table, imd->lookup_table_entry);
 403
 404         /* Get rid of the empty slot in the image metadata array. */
 405         for (i = image - 1; i < w->hdr.image_count - 1; i++)
 406                 memcpy(&w->image_metadata[i], &w->image_metadata[i + 1],
 407                                 sizeof(struct image_metadata));
 408
 409         /* Decrement the image count. */
 410         w->hdr.image_count--;
 411         if (w->hdr.image_count == 0) {
 412                 FREE(w->image_metadata);
 413                 w->image_metadata = NULL;
 414         }
 415
 416         /* Fix the boot index. */
 417         if (w->hdr.boot_idx == image)
 418                 w->hdr.boot_idx = 0;
 419         else if (w->hdr.boot_idx > image)
 420                 w->hdr.boot_idx--;
 421
 422         w->current_image = WIM_NO_IMAGE;
 423
 424         /* Remove the image from the XML information. */
 425         xml_delete_image(&w->wim_info, image);
 426         return 0;
 427 }
 428
 429 /*
 430  * Adds an image to a WIM file from a directory tree on disk.
 431  */
 432 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 433                                const char *name, const char *description,
 434                                const char *flags_element, int flags)
 435 {
 436         struct dentry *root_dentry;
 437         struct stat root_stat;
 438         int ret;
 439
 440         DEBUG("Adding dentry tree from dir `%s'\n", dir);
 441
 442         if (!name || !*name) {
 443                 ERROR("Must specify a non-empty string for the image name!\n");
 444                 return WIMLIB_ERR_INVALID_PARAM;
 445         }
 446         if (!dir) {
 447                 ERROR("Must specify the name of a directory!\n");
 448                 return WIMLIB_ERR_INVALID_PARAM;
 449         }
 450
 451         if (wimlib_image_name_in_use(w, name)) {
 452                 ERROR("There is already an image named `%s' in %s!\n",
 453                                 name, w->filename);
 454                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 455         }
 456
 457         DEBUG("Creating root dentry.\n");
 458
 459         root_dentry = new_dentry("");
 460         ret = calculate_dentry_full_path(root_dentry, NULL);
 461         if (ret != 0)
 462                 return ret;
 463         root_dentry->attributes |= WIM_FILE_ATTRIBUTE_DIRECTORY;
 464
 465         /* Construct the dentry tree from the outside filesystem. */
 466         if (stat(dir, &root_stat) != 0) {
 467                 ERROR("Failed to stat `%s': %m\n", dir);
 468                 return WIMLIB_ERR_STAT;
 469         }
 470         if (!S_ISDIR(root_stat.st_mode)) {
 471                 ERROR("`%s' is not a directory!\n", dir);
 472                 return WIMLIB_ERR_NOTDIR;
 473         }
 474         DEBUG("Building dentry tree.\n");
 475         ret = build_dentry_tree(root_dentry, dir, &root_stat,
 476                                 w->lookup_table);
 477
 478         if (ret != 0) {
 479                 ERROR("Failed to build dentry tree for `%s'!\n", dir);
 480                 goto err1;
 481         }
 482
 483         DEBUG("Recalculating full paths of dentries.\n");
 484         ret = for_dentry_in_tree(root_dentry,
 485                                  calculate_dentry_full_path, NULL);
 486         if (ret != 0) {
 487                 ERROR("Failed to calculate full paths of dentry tree.\n");
 488                 goto err1;
 489         }
 490
 491         ret = add_new_dentry_tree(w, root_dentry);
 492         if (ret != 0)
 493                 goto err1;
 494
 495         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT) {
 496                 /* Call wimlib_set_boot_idx rather than set boot_idx directly so
 497                  * that the boot metadata resource entry in the header gets
 498                  * updated. */
 499                 wimlib_set_boot_idx(w, w->hdr.image_count);
 500         }
 501
 502         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 503         if (ret != 0)
 504                 goto err1;
 505
 506         return 0;
 507 err1:
 508         free_dentry_tree(root_dentry, w->lookup_table, true);
 509         return ret;
 510 }