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