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