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
  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 void destroy_image_metadata(struct image_metadata *imd,struct lookup_table *lt)
  46 {
  47         free_dentry_tree(imd->root_dentry, lt);
  48         free_security_data(imd->security_data);
  49         free_link_group_table(imd->lgt);
  50
  51         /* Get rid of the lookup table entry for this image's metadata resource
  52          * */
  53         if (lt)
  54                 lookup_table_remove(lt, imd->metadata_lte);
  55 }
  56
  57 /*
  58  * Recursively builds a dentry tree from a directory tree on disk, outside the
  59  * WIM file.
  60  *
  61  * @root:  A dentry that has already been created for the root of the dentry
  62  *         tree.
  63  * @root_disk_path:  The path to the root of the tree on disk.
  64  * @lookup_table: The lookup table for the WIM file.  For each file added to the
  65  *              dentry tree being built, an entry is added to the lookup table,
  66  *              unless an identical file is already in the lookup table.  These
  67  *              lookup table entries that are added point to the file on disk.
  68  *
  69  * @return:     0 on success, nonzero on failure.  It is a failure if any of
  70  *              the files cannot be `stat'ed, or if any of the needed
  71  *              directories cannot be opened or read.  Failure to add the files
  72  *              to the WIM may still occur later when trying to actually read
  73  *              the regular files in the tree into the WIM as file resources.
  74  */
  75 static int build_dentry_tree(struct dentry *root, const char *root_disk_path,
  76                              struct lookup_table* lookup_table,
  77                              int add_flags)
  78 {
  79         DEBUG("%s", root_disk_path);
  80         struct stat root_stbuf;
  81         int ret = 0;
  82         int (*stat_fn)(const char *restrict, struct stat *restrict);
  83
  84         if (add_flags & WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)
  85                 stat_fn = stat;
  86         else
  87                 stat_fn = lstat;
  88
  89         if (add_flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE)
  90                 printf("Scanning `%s'\n", root_disk_path);
  91
  92
  93         ret = (*stat_fn)(root_disk_path, &root_stbuf);
  94         if (ret != 0) {
  95                 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
  96                 return WIMLIB_ERR_STAT;
  97         }
  98
  99         if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
 100               !S_ISDIR(root_stbuf.st_mode)) {
 101                 ERROR("`%s' is not a directory", root_disk_path);
 102                 return WIMLIB_ERR_NOTDIR;
 103         }
 104         if (!S_ISREG(root_stbuf.st_mode) && !S_ISDIR(root_stbuf.st_mode)
 105             && !S_ISLNK(root_stbuf.st_mode)) {
 106                 ERROR("`%s' is not a regular file, directory, or symbolic link.");
 107                 return WIMLIB_ERR_SPECIAL_FILE;
 108         }
 109         stbuf_to_dentry(&root_stbuf, root);
 110         add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
 111         root->resolved = true;
 112
 113         if (dentry_is_directory(root)) {
 114                 /* Open the directory on disk */
 115                 DIR *dir;
 116                 struct dirent *p;
 117                 struct dentry *child;
 118
 119                 dir = opendir(root_disk_path);
 120                 if (!dir) {
 121                         ERROR_WITH_ERRNO("Failed to open the directory `%s'",
 122                                          root_disk_path);
 123                         return WIMLIB_ERR_OPEN;
 124                 }
 125
 126                 /* Buffer for names of files in directory. */
 127                 size_t len = strlen(root_disk_path);
 128                 char name[len + 1 + FILENAME_MAX + 1];
 129                 memcpy(name, root_disk_path, len);
 130                 name[len] = '/';
 131
 132                 /* Create a dentry for each entry in the directory on disk, and recurse
 133                  * to any subdirectories. */
 134                 while ((p = readdir(dir)) != NULL) {
 135                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
 136                               || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
 137                                         continue;
 138                         strcpy(name + len + 1, p->d_name);
 139                         child = new_dentry(p->d_name);
 140                         if (!child)
 141                                 return WIMLIB_ERR_NOMEM;
 142                         ret = build_dentry_tree(child, name, lookup_table,
 143                                                 add_flags);
 144                         link_dentry(child, root);
 145                         if (ret != 0)
 146                                 break;
 147                 }
 148                 closedir(dir);
 149         } else if (dentry_is_symlink(root)) {
 150                 /* Archiving a symbolic link */
 151                 size_t symlink_buf_len;
 152                 char deref_name_buf[4096];
 153                 ssize_t deref_name_len;
 154
 155                 deref_name_len = readlink(root_disk_path, deref_name_buf,
 156                                           sizeof(deref_name_buf) - 1);
 157                 if (deref_name_len == -1) {
 158                         ERROR_WITH_ERRNO("Failed to read target of "
 159                                          "symbolic link `%s'", root_disk_path);
 160                         return WIMLIB_ERR_READLINK;
 161                 }
 162                 deref_name_buf[deref_name_len] = '\0';
 163                 DEBUG("Read symlink `%s'", deref_name_buf);
 164                 ret = dentry_set_symlink(root, deref_name_buf,
 165                                          lookup_table, NULL);
 166         } else {
 167                 /* Regular file */
 168                 struct lookup_table_entry *lte;
 169                 u8 hash[SHA1_HASH_SIZE];
 170
 171                 /* For each regular file, we must check to see if the file is in
 172                  * the lookup table already; if it is, we increment its refcnt;
 173                  * otherwise, we create a new lookup table entry and insert it.
 174                  * */
 175                 ret = sha1sum(root_disk_path, hash);
 176                 if (ret != 0)
 177                         return ret;
 178
 179                 lte = __lookup_resource(lookup_table, hash);
 180                 if (lte) {
 181                         lte->refcnt++;
 182                         DEBUG("Add lte reference %u for `%s'", lte->refcnt,
 183                               root_disk_path);
 184                 } else {
 185                         char *file_on_disk = STRDUP(root_disk_path);
 186                         if (!file_on_disk) {
 187                                 ERROR("Failed to allocate memory for file path");
 188                                 return WIMLIB_ERR_NOMEM;
 189                         }
 190                         lte = new_lookup_table_entry();
 191                         if (!lte) {
 192                                 FREE(file_on_disk);
 193                                 return WIMLIB_ERR_NOMEM;
 194                         }
 195                         lte->file_on_disk = file_on_disk;
 196                         lte->resource_location = RESOURCE_IN_FILE_ON_DISK;
 197                         lte->resource_entry.original_size = root_stbuf.st_size;
 198                         lte->resource_entry.size = root_stbuf.st_size;
 199                         copy_hash(lte->hash, hash);
 200                         lookup_table_insert(lookup_table, lte);
 201                 }
 202                 root->lte = lte;
 203         }
 204         return ret;
 205 }
 206
 207 struct wim_pair {
 208         WIMStruct *src_wim;
 209         WIMStruct *dest_wim;
 210 };
 211
 212 /*
 213  * This function takes in a dentry that was previously located only in image(s)
 214  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 215  * lookup table entry for this file in the lookup table of the destination WIM
 216  * file, we simply increment its reference count.  Otherwise, a new lookup table
 217  * entry is created that references the location of the file resource in the
 218  * source WIM file through the other_wim_fp field of the lookup table entry.
 219  */
 220 static int add_lte_to_dest_wim(struct dentry *dentry, void *arg)
 221 {
 222         WIMStruct *src_wim, *dest_wim;
 223
 224         src_wim = ((struct wim_pair*)arg)->src_wim;
 225         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 226
 227         wimlib_assert(!dentry->resolved);
 228
 229         for (unsigned i = 0; i < (unsigned)dentry->num_ads + 1; i++) {
 230                 struct lookup_table_entry *src_lte, *dest_lte;
 231                 src_lte = dentry_stream_lte_unresolved(dentry, i,
 232                                                        src_wim->lookup_table);
 233                 if (!src_lte)
 234                         continue;
 235                 dest_lte = dentry_stream_lte_unresolved(dentry, i,
 236                                                         dest_wim->lookup_table);
 237                 if (dest_lte) {
 238                         dest_lte->refcnt++;
 239                 } else {
 240                         dest_lte = new_lookup_table_entry();
 241                         if (!dest_lte)
 242                                 return WIMLIB_ERR_NOMEM;
 243                         dest_lte->resource_location = RESOURCE_IN_WIM;
 244                         dest_lte->wim = src_wim;
 245                         memcpy(&dest_lte->resource_entry,
 246                                &src_lte->resource_entry,
 247                                sizeof(struct resource_entry));
 248                         copy_hash(dest_lte->hash,
 249                                   dentry_stream_hash_unresolved(dentry, i));
 250                         lookup_table_insert(dest_wim->lookup_table, dest_lte);
 251                 }
 252         }
 253         return 0;
 254 }
 255
 256 /*
 257  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 258  * file, adds an entry to the lookup table for the image metadata, updates the
 259  * image count in the header, and selects the new image.
 260  *
 261  * Does not update the XML data.
 262  *
 263  * @w:            The WIMStruct for the WIM file.
 264  * @root_dentry:  The root of the directory tree for the image.
 265  */
 266 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 267 {
 268         struct lookup_table_entry *metadata_lte;
 269         struct image_metadata *imd;
 270         struct image_metadata *new_imd;
 271         struct wim_security_data *sd;
 272         struct link_group_table *lgt;
 273
 274         DEBUG("Reallocating image metadata array for image_count = %u",
 275               w->hdr.image_count + 1);
 276         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 277
 278         if (!imd) {
 279                 ERROR("Failed to allocate memory for new image metadata array");
 280                 return WIMLIB_ERR_NOMEM;
 281         }
 282
 283         memcpy(imd, w->image_metadata,
 284                w->hdr.image_count * sizeof(struct image_metadata));
 285
 286         metadata_lte = new_lookup_table_entry();
 287         if (!metadata_lte)
 288                 goto out_free_imd;
 289         sd = CALLOC(1, sizeof(struct wim_security_data));
 290         if (!sd)
 291                 goto out_free_metadata_lte;
 292         sd->refcnt = 1;
 293         sd->total_length = 8;
 294
 295         lgt = new_link_group_table(9001);
 296         if (!lgt)
 297                 goto out_free_security_data;
 298
 299         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 300         random_hash(metadata_lte->hash);
 301         lookup_table_insert(w->lookup_table, metadata_lte);
 302
 303         new_imd = &imd[w->hdr.image_count];
 304
 305         new_imd->root_dentry    = root_dentry;
 306         new_imd->metadata_lte   = metadata_lte;
 307         new_imd->security_data  = sd;
 308         new_imd->lgt            = lgt;
 309         new_imd->modified       = true;
 310
 311         FREE(w->image_metadata);
 312         w->image_metadata       = imd;
 313         w->hdr.image_count++;
 314
 315         /* Change the current image to the new one. */
 316         return wimlib_select_image(w, w->hdr.image_count);
 317 out_free_security_data:
 318         FREE(sd);
 319 out_free_metadata_lte:
 320         FREE(metadata_lte);
 321 out_free_imd:
 322         FREE(imd);
 323         return WIMLIB_ERR_NOMEM;
 324
 325 }
 326
 327 /*
 328  * Copies an image, or all the images, from a WIM file, into another WIM file.
 329  */
 330 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 331                                   int src_image,
 332                                   WIMStruct *dest_wim,
 333                                   const char *dest_name,
 334                                   const char *dest_description,
 335                                   int flags)
 336 {
 337         int i;
 338         int ret;
 339         struct dentry *root;
 340         struct wim_pair wims;
 341
 342         if (src_image == WIM_ALL_IMAGES) {
 343                 if (src_wim->hdr.image_count > 1) {
 344
 345                         /* multi-image export. */
 346
 347                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 348                               (src_wim->hdr.boot_idx == 0))
 349                         {
 350                                 /* Specifying the boot flag on a multi-image
 351                                  * source WIM makes the boot index default to
 352                                  * the bootable image in the source WIM.  It is
 353                                  * an error if there is no such bootable image.
 354                                  * */
 355                                 ERROR("Cannot specify `boot' flag when "
 356                                       "exporting multiple images from a WIM "
 357                                       "with no bootable images");
 358                                 return WIMLIB_ERR_INVALID_PARAM;
 359                         }
 360                         if (dest_name || dest_description) {
 361                                 ERROR("Image name or image description was "
 362                                       "specified, but we are exporting "
 363                                       "multiple images");
 364                                 return WIMLIB_ERR_INVALID_PARAM;
 365                         }
 366                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 367                                 int export_flags = flags;
 368
 369                                 if (i != src_wim->hdr.boot_idx)
 370                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 371
 372                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 373                                                           NULL,
 374                                                           dest_description,
 375                                                           export_flags);
 376                                 if (ret != 0)
 377                                         return ret;
 378                         }
 379                         return 0;
 380                 } else {
 381                         src_image = 1;
 382                 }
 383         }
 384
 385         ret = wimlib_select_image(src_wim, src_image);
 386         if (ret != 0) {
 387                 ERROR("Could not select image %d from the WIM `%s' "
 388                       "to export it", src_image, src_wim->filename);
 389                 return ret;
 390         }
 391
 392         if (!dest_name) {
 393                 dest_name = wimlib_get_image_name(src_wim, src_image);
 394                 DEBUG("Using name `%s' for source image %d",
 395                       dest_name, src_image);
 396         }
 397
 398         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 399
 400         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 401                 ERROR("There is already an image named `%s' in the "
 402                       "destination WIM", dest_name);
 403                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 404         }
 405
 406
 407         /* Cleaning up here on failure would be hard.  For example, we could
 408          * fail to allocate memory in add_lte_to_dest_wim(),
 409          * leaving the lookup table entries in the destination WIM in an
 410          * inconsistent state.  Until these issues can be resolved,
 411          * wimlib_export_image() is documented as leaving dest_wim is an
 412          * indeterminate state.  */
 413         root = wim_root_dentry(src_wim);
 414         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 415         wims.src_wim = src_wim;
 416         wims.dest_wim = dest_wim;
 417         ret = for_dentry_in_tree(root, add_lte_to_dest_wim, &wims);
 418         if (ret != 0)
 419                 return ret;
 420         ret = add_new_dentry_tree(dest_wim, root);
 421         if (ret != 0)
 422                 return ret;
 423         /* Bring over old security data */
 424         struct wim_security_data *sd = wim_security_data(src_wim);
 425         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 426         wimlib_assert(sd);
 427         free_security_data(new_imd->security_data);
 428         new_imd->security_data = sd;
 429         sd->refcnt++;
 430
 431         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 432                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 433                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 434         }
 435
 436         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 437                                 dest_name, dest_description);
 438 }
 439
 440 /*
 441  * Deletes an image from the WIM.
 442  */
 443 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 444 {
 445         int num_images;
 446         int i;
 447         int ret;
 448
 449         if (image == WIM_ALL_IMAGES) {
 450                 num_images = w->hdr.image_count;
 451                 for (i = 1; i <= num_images; i++) {
 452                         /* Always delete the first image, since by the end
 453                          * there won't be any more than that!  */
 454                         ret = wimlib_delete_image(w, 1);
 455                         if (ret != 0)
 456                                 return ret;
 457                 }
 458                 return 0;
 459         }
 460
 461         DEBUG("Deleting image %d", image);
 462
 463         /* Even if the dentry tree is not allocated, we must select it (and
 464          * therefore allocate it) so that we can decrement the reference counts
 465          * in the lookup table.  */
 466         ret = wimlib_select_image(w, image);
 467         if (ret != 0)
 468                 return ret;
 469
 470         /* Free the dentry tree, any lookup table entries that have their
 471          * refcnt decremented to 0, and the security data. */
 472         destroy_image_metadata(wim_get_current_image_metadata(w),
 473                                w->lookup_table);
 474
 475         /* Get rid of the empty slot in the image metadata array. */
 476         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 477                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 478
 479         /* Decrement the image count. */
 480         if (--w->hdr.image_count == 0) {
 481                 FREE(w->image_metadata);
 482                 w->image_metadata = NULL;
 483         }
 484
 485         /* Fix the boot index. */
 486         if (w->hdr.boot_idx == image)
 487                 w->hdr.boot_idx = 0;
 488         else if (w->hdr.boot_idx > image)
 489                 w->hdr.boot_idx--;
 490
 491         w->current_image = WIM_NO_IMAGE;
 492
 493         /* Remove the image from the XML information. */
 494         xml_delete_image(&w->wim_info, image);
 495         return 0;
 496 }
 497
 498 /*
 499  * Adds an image to a WIM file from a directory tree on disk.
 500  */
 501 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 502                                const char *name, const char *description,
 503                                const char *flags_element, int flags)
 504 {
 505         struct dentry *root_dentry;
 506         struct image_metadata *imd;
 507         int ret;
 508
 509         DEBUG("Adding dentry tree from dir `%s'.", dir);
 510
 511         if (!name || !*name) {
 512                 ERROR("Must specify a non-empty string for the image name");
 513                 return WIMLIB_ERR_INVALID_PARAM;
 514         }
 515         if (!dir) {
 516                 ERROR("Must specify the name of a directory");
 517                 return WIMLIB_ERR_INVALID_PARAM;
 518         }
 519
 520         if (wimlib_image_name_in_use(w, name)) {
 521                 ERROR("There is already an image named \"%s\" in `%s'",
 522                       name, w->filename);
 523                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 524         }
 525
 526         DEBUG("Creating root dentry.");
 527
 528         root_dentry = new_dentry("");
 529         if (!root_dentry)
 530                 return WIMLIB_ERR_NOMEM;
 531
 532         DEBUG("Building dentry tree.");
 533         ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
 534                                 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
 535
 536         if (ret != 0) {
 537                 ERROR("Failed to build dentry tree for `%s'", dir);
 538                 goto out_free_dentry_tree;
 539         }
 540
 541         DEBUG("Calculating full paths of dentries.");
 542         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 543         if (ret != 0)
 544                 goto out_free_dentry_tree;
 545
 546         ret = add_new_dentry_tree(w, root_dentry);
 547         if (ret != 0)
 548                 goto out_free_dentry_tree;
 549
 550         DEBUG("Inserting dentries into hard link group table");
 551         ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
 552                                  w->image_metadata[w->hdr.image_count - 1].lgt);
 553         if (ret != 0)
 554                 goto out_destroy_imd;
 555         DEBUG("Assigning hard link groups");
 556         assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
 557
 558         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 559                 wimlib_set_boot_idx(w, w->hdr.image_count);
 560
 561         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 562         if (ret != 0)
 563                 goto out_destroy_imd;
 564
 565         return 0;
 566 out_destroy_imd:
 567         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 568                                w->lookup_table);
 569         w->hdr.image_count--;
 570         return ret;
 571 out_free_dentry_tree:
 572         free_dentry_tree(root_dentry, w->lookup_table);
 573         return ret;
 574 }