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   1 /*
   2  * modify.c
   3  *
   4  * Support for modifying WIM files with image-level operations (delete an image,
   5  * add an image, export an imagex from one WIM to another.)  There is nothing
   6  * here that lets you change individual files in the WIM; for that you will need
   7  * to look at the filesystem implementation in mount.c.
   8  */
   9
  10 /*
  11  * Copyright (C) 2012 Eric Biggers
  12  *
  13  * This file is part of wimlib, a library for working with WIM files.
  14  *
  15  * wimlib is free software; you can redistribute it and/or modify it under the
  16  * terms of the GNU Lesser General Public License as published by the Free
  17  * Software Foundation; either version 2.1 of the License, or (at your option)
  18  * any later version.
  19  *
  20  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  21  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  22  * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  23  * details.
  24  *
  25  * You should have received a copy of the GNU Lesser General Public License
  26  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  27  */
  28
  29 #include "wimlib_internal.h"
  30 #include "util.h"
  31 #include "sha1.h"
  32 #include "dentry.h"
  33 #include "xml.h"
  34 #include "lookup_table.h"
  35 #include <sys/stat.h>
  36 #include <dirent.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #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;
  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
  90         ret = (*stat_fn)(root_disk_path, &root_stbuf);
  91         if (ret != 0) {
  92                 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
  93                 return WIMLIB_ERR_STAT;
  94         }
  95
  96         if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
  97               !S_ISDIR(root_stbuf.st_mode)) {
  98                 ERROR("`%s' is not a directory", root_disk_path);
  99                 return WIMLIB_ERR_NOTDIR;
 100         }
 101         stbuf_to_dentry(&root_stbuf, root);
 102         add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
 103
 104         if (dentry_is_directory(root)) {
 105                 /* Open the directory on disk */
 106                 DIR *dir;
 107                 struct dirent *p;
 108                 struct dentry *child;
 109
 110                 dir = opendir(root_disk_path);
 111                 if (!dir) {
 112                         ERROR_WITH_ERRNO("Failed to open the directory `%s'",
 113                                          root_disk_path);
 114                         return WIMLIB_ERR_OPEN;
 115                 }
 116
 117                 /* Buffer for names of files in directory. */
 118                 size_t len = strlen(root_disk_path);
 119                 char name[len + 1 + FILENAME_MAX + 1];
 120                 memcpy(name, root_disk_path, len);
 121                 name[len] = '/';
 122
 123                 /* Create a dentry for each entry in the directory on disk, and recurse
 124                  * to any subdirectories. */
 125                 while ((p = readdir(dir)) != NULL) {
 126                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
 127                               || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
 128                                         continue;
 129                         strcpy(name + len + 1, p->d_name);
 130                         child = new_dentry(p->d_name);
 131                         if (!child)
 132                                 return WIMLIB_ERR_NOMEM;
 133                         ret = build_dentry_tree(child, name, lookup_table,
 134                                                 add_flags);
 135                         link_dentry(child, root);
 136                         if (ret != 0)
 137                                 break;
 138                 }
 139                 closedir(dir);
 140         } else if (dentry_is_symlink(root)) {
 141                 /* Archiving a symbolic link */
 142                 size_t symlink_buf_len;
 143                 char deref_name_buf[4096];
 144                 ssize_t ret = readlink(root_disk_path, deref_name_buf,
 145                                        sizeof(deref_name_buf) - 1);
 146                 if (ret == -1) {
 147                         ERROR_WITH_ERRNO("Failed to read target of "
 148                                          "symbolic link `%s'", root_disk_path);
 149                         return WIMLIB_ERR_STAT;
 150                 }
 151                 deref_name_buf[ret] = '\0';
 152                 DEBUG("Read symlink `%s'", deref_name_buf);
 153                 ret = dentry_set_symlink(root, deref_name_buf,
 154                                          lookup_table, NULL);
 155         } else {
 156                 /* Regular file */
 157                 struct lookup_table_entry *lte;
 158
 159                 /* For each regular file, we must check to see if the file is in
 160                  * the lookup table already; if it is, we increment its refcnt;
 161                  * otherwise, we create a new lookup table entry and insert it.
 162                  * */
 163                 ret = sha1sum(root_disk_path, root->hash);
 164                 if (ret != 0)
 165                         return ret;
 166
 167                 lte = __lookup_resource(lookup_table, root->hash);
 168                 if (lte) {
 169                         lte->refcnt++;
 170                 } else {
 171                         char *file_on_disk = STRDUP(root_disk_path);
 172                         if (!file_on_disk) {
 173                                 ERROR("Failed to allocate memory for file path");
 174                                 return WIMLIB_ERR_NOMEM;
 175                         }
 176                         lte = new_lookup_table_entry();
 177                         if (!lte) {
 178                                 FREE(file_on_disk);
 179                                 return WIMLIB_ERR_NOMEM;
 180                         }
 181                         lte->file_on_disk = file_on_disk;
 182                         lte->resource_entry.original_size = root_stbuf.st_size;
 183                         lte->resource_entry.size = root_stbuf.st_size;
 184                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 185                         lookup_table_insert(lookup_table, lte);
 186                 }
 187         }
 188         return ret;
 189 }
 190
 191 struct wim_pair {
 192         WIMStruct *src_wim;
 193         WIMStruct *dest_wim;
 194 };
 195
 196 /*
 197  * This function takes in a dentry that was previously located only in image(s)
 198  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 199  * lookup table entry for this file in the lookup table of the destination WIM
 200  * file, we simply increment its reference count.  Otherwise, a new lookup table
 201  * entry is created that references the location of the file resource in the
 202  * source WIM file through the other_wim_fp field of the lookup table entry.
 203  */
 204 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 205 {
 206         WIMStruct *src_wim, *dest_wim;
 207         struct lookup_table_entry *src_table_entry;
 208         struct lookup_table_entry *dest_table_entry;
 209
 210         src_wim = ((struct wim_pair*)arg)->src_wim;
 211         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 212
 213         if (dentry_is_directory(dentry))
 214                 return 0;
 215
 216         /* XXX ADS */
 217         src_table_entry = __lookup_resource(src_wim->lookup_table, dentry->hash);
 218         if (!src_table_entry)
 219                 return 0;
 220
 221         /* XXX ADS */
 222         dest_table_entry = __lookup_resource(dest_wim->lookup_table, dentry->hash);
 223         if (dest_table_entry) {
 224                 dest_table_entry->refcnt++;
 225         } else {
 226                 dest_table_entry = new_lookup_table_entry();
 227                 if (!dest_table_entry)
 228                         return WIMLIB_ERR_NOMEM;
 229                 dest_table_entry->other_wim_fp = src_wim->fp;
 230                 dest_table_entry->other_wim_ctype =
 231                                 wimlib_get_compression_type(src_wim);
 232                 dest_table_entry->refcnt = 1;
 233                 memcpy(&dest_table_entry->resource_entry,
 234                        &src_table_entry->resource_entry,
 235                        sizeof(struct resource_entry));
 236                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 237                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 238         }
 239         return 0;
 240 }
 241
 242 /*
 243  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 244  * file, adds an entry to the lookup table for the image metadata, updates the
 245  * image count in the header, and selects the new image.
 246  *
 247  * Does not update the XML data.
 248  *
 249  * @w:            The WIMStruct for the WIM file.
 250  * @root_dentry:  The root of the directory tree for the image.
 251  */
 252 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 253 {
 254         struct lookup_table_entry *metadata_lte;
 255         struct image_metadata *imd;
 256         struct image_metadata *new_imd;
 257         struct wim_security_data *sd;
 258         struct link_group_table *lgt;
 259
 260         DEBUG("Reallocating image metadata array for image_count = %u",
 261               w->hdr.image_count + 1);
 262         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 263
 264         if (!imd) {
 265                 ERROR("Failed to allocate memory for new image metadata array");
 266                 return WIMLIB_ERR_NOMEM;
 267         }
 268
 269         memcpy(imd, w->image_metadata,
 270                w->hdr.image_count * sizeof(struct image_metadata));
 271
 272         metadata_lte = new_lookup_table_entry();
 273         if (!metadata_lte)
 274                 goto out_free_imd;
 275         sd = CALLOC(1, sizeof(struct wim_security_data));
 276         if (!sd)
 277                 goto out_free_metadata_lte;
 278         sd->refcnt = 1;
 279         sd->total_length = 8;
 280
 281         lgt = new_link_group_table(9001);
 282         if (!lgt)
 283                 goto out_free_security_data;
 284
 285         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 286         randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
 287         lookup_table_insert(w->lookup_table, metadata_lte);
 288
 289         new_imd = &imd[w->hdr.image_count];
 290
 291         new_imd->root_dentry    = root_dentry;
 292         new_imd->metadata_lte   = metadata_lte;
 293         new_imd->security_data  = sd;
 294         new_imd->lgt            = lgt;
 295         new_imd->modified       = true;
 296
 297         FREE(w->image_metadata);
 298         w->image_metadata       = imd;
 299         w->hdr.image_count++;
 300
 301         /* Change the current image to the new one. */
 302         return wimlib_select_image(w, w->hdr.image_count);
 303 out_free_security_data:
 304         FREE(sd);
 305 out_free_metadata_lte:
 306         FREE(metadata_lte);
 307 out_free_imd:
 308         FREE(imd);
 309         return WIMLIB_ERR_NOMEM;
 310
 311 }
 312
 313 /*
 314  * Copies an image, or all the images, from a WIM file, into another WIM file.
 315  */
 316 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 317                                   int src_image,
 318                                   WIMStruct *dest_wim,
 319                                   const char *dest_name,
 320                                   const char *dest_description,
 321                                   int flags)
 322 {
 323         int i;
 324         int ret;
 325         struct dentry *root;
 326         struct wim_pair wims;
 327
 328         if (src_image == WIM_ALL_IMAGES) {
 329                 if (src_wim->hdr.image_count > 1) {
 330
 331                         /* multi-image export. */
 332
 333                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 334                               (src_wim->hdr.boot_idx == 0))
 335                         {
 336                                 /* Specifying the boot flag on a multi-image
 337                                  * source WIM makes the boot index default to
 338                                  * the bootable image in the source WIM.  It is
 339                                  * an error if there is no such bootable image.
 340                                  * */
 341                                 ERROR("Cannot specify `boot' flag when "
 342                                       "exporting multiple images from a WIM "
 343                                       "with no bootable images");
 344                                 return WIMLIB_ERR_INVALID_PARAM;
 345                         }
 346                         if (dest_name || dest_description) {
 347                                 ERROR("Image name or image description was "
 348                                       "specified, but we are exporting "
 349                                       "multiple images");
 350                                 return WIMLIB_ERR_INVALID_PARAM;
 351                         }
 352                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 353                                 int export_flags = flags;
 354
 355                                 if (i != src_wim->hdr.boot_idx)
 356                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 357
 358                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 359                                                           NULL,
 360                                                           dest_description,
 361                                                           export_flags);
 362                                 if (ret != 0)
 363                                         return ret;
 364                         }
 365                         return 0;
 366                 } else {
 367                         src_image = 1;
 368                 }
 369         }
 370
 371         ret = wimlib_select_image(src_wim, src_image);
 372         if (ret != 0) {
 373                 ERROR("Could not select image %d from the WIM `%s' "
 374                       "to export it", src_image, src_wim->filename);
 375                 return ret;
 376         }
 377
 378         if (!dest_name) {
 379                 dest_name = wimlib_get_image_name(src_wim, src_image);
 380                 DEBUG("Using name `%s' for source image %d",
 381                       dest_name, src_image);
 382         }
 383
 384         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 385
 386         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 387                 ERROR("There is already an image named `%s' in the "
 388                       "destination WIM", dest_name);
 389                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 390         }
 391
 392
 393         /* Cleaning up here on failure would be hard.  For example, we could
 394          * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
 395          * leaving the lookup table entries in the destination WIM in an
 396          * inconsistent state.  Until these issues can be resolved,
 397          * wimlib_export_image() is documented as leaving dest_wim is an
 398          * indeterminate state.  */
 399         root = wim_root_dentry(src_wim);
 400         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 401         wims.src_wim = src_wim;
 402         wims.dest_wim = dest_wim;
 403         ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 404         if (ret != 0)
 405                 return ret;
 406         ret = add_new_dentry_tree(dest_wim, root);
 407         if (ret != 0)
 408                 return ret;
 409         /* Bring over old security data */
 410         struct wim_security_data *sd = wim_security_data(src_wim);
 411         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 412         wimlib_assert(sd);
 413         free_security_data(new_imd->security_data);
 414         new_imd->security_data = sd;
 415         sd->refcnt++;
 416
 417         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 418                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 419                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 420         }
 421
 422         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 423                                 dest_name, dest_description);
 424 }
 425
 426 /*
 427  * Deletes an image from the WIM.
 428  */
 429 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 430 {
 431         int num_images;
 432         int i;
 433         int ret;
 434
 435         if (image == WIM_ALL_IMAGES) {
 436                 num_images = w->hdr.image_count;
 437                 for (i = 1; i <= num_images; i++) {
 438                         /* Always delete the first image, since by the end
 439                          * there won't be any more than that!  */
 440                         ret = wimlib_delete_image(w, 1);
 441                         if (ret != 0)
 442                                 return ret;
 443                 }
 444                 return 0;
 445         }
 446
 447         DEBUG("Deleting image %d", image);
 448
 449         /* Even if the dentry tree is not allocated, we must select it (and
 450          * therefore allocate it) so that we can decrement the reference counts
 451          * in the lookup table.  */
 452         ret = wimlib_select_image(w, image);
 453         if (ret != 0)
 454                 return ret;
 455
 456         /* Free the dentry tree, any lookup table entries that have their
 457          * refcnt decremented to 0, and the security data. */
 458         destroy_image_metadata(wim_get_current_image_metadata(w),
 459                                w->lookup_table);
 460
 461         /* Get rid of the empty slot in the image metadata array. */
 462         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 463                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 464
 465         /* Decrement the image count. */
 466         if (--w->hdr.image_count == 0) {
 467                 FREE(w->image_metadata);
 468                 w->image_metadata = NULL;
 469         }
 470
 471         /* Fix the boot index. */
 472         if (w->hdr.boot_idx == image)
 473                 w->hdr.boot_idx = 0;
 474         else if (w->hdr.boot_idx > image)
 475                 w->hdr.boot_idx--;
 476
 477         w->current_image = WIM_NO_IMAGE;
 478
 479         /* Remove the image from the XML information. */
 480         xml_delete_image(&w->wim_info, image);
 481         return 0;
 482 }
 483
 484 /*
 485  * Adds an image to a WIM file from a directory tree on disk.
 486  */
 487 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 488                                const char *name, const char *description,
 489                                const char *flags_element, int flags)
 490 {
 491         struct dentry *root_dentry;
 492         struct image_metadata *imd;
 493         int ret;
 494
 495         DEBUG("Adding dentry tree from dir `%s'.", dir);
 496
 497         if (!name || !*name) {
 498                 ERROR("Must specify a non-empty string for the image name");
 499                 return WIMLIB_ERR_INVALID_PARAM;
 500         }
 501         if (!dir) {
 502                 ERROR("Must specify the name of a directory");
 503                 return WIMLIB_ERR_INVALID_PARAM;
 504         }
 505
 506         if (wimlib_image_name_in_use(w, name)) {
 507                 ERROR("There is already an image named \"%s\" in `%s'",
 508                       name, w->filename);
 509                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 510         }
 511
 512         DEBUG("Creating root dentry.");
 513
 514         root_dentry = new_dentry("");
 515         if (!root_dentry)
 516                 return WIMLIB_ERR_NOMEM;
 517         ret = calculate_dentry_full_path(root_dentry, NULL);
 518
 519         if (ret != 0)
 520                 goto out_free_dentry_tree;
 521
 522         root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
 523
 524         DEBUG("Building dentry tree.");
 525         ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
 526                                 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
 527
 528         if (ret != 0) {
 529                 ERROR("Failed to build dentry tree for `%s'", dir);
 530                 goto out_free_dentry_tree;
 531         }
 532
 533         DEBUG("Recalculating full paths of dentries.");
 534         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 535         if (ret != 0)
 536                 goto out_free_dentry_tree;
 537
 538         ret = add_new_dentry_tree(w, root_dentry);
 539         if (ret != 0)
 540                 goto out_free_dentry_tree;
 541
 542         DEBUG("Inserting dentries into hard link group table");
 543         ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
 544                                  w->image_metadata[w->hdr.image_count - 1].lgt);
 545         if (ret != 0)
 546                 goto out_destroy_imd;
 547         DEBUG("Assigning hard link groups");
 548         assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
 549
 550         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 551                 wimlib_set_boot_idx(w, w->hdr.image_count);
 552
 553         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 554         if (ret != 0)
 555                 goto out_destroy_imd;
 556
 557         return 0;
 558 out_destroy_imd:
 559         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 560                                w->lookup_table);
 561         w->hdr.image_count--;
 562         return ret;
 563 out_free_dentry_tree:
 564         free_dentry_tree(root_dentry, w->lookup_table);
 565         return ret;
 566 }