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