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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         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                 void *symlink_buf = make_symlink_reparse_data_buf(deref_name_buf,
 157                                                                   &symlink_buf_len);
 158                 if (!symlink_buf)
 159                         return WIMLIB_ERR_NOMEM;
 160                 DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
 161                                 symlink_buf_len, ret);
 162
 163                 u8 symlink_buf_hash[WIM_HASH_SIZE];
 164                 sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
 165
 166                 ret = dentry_set_symlink_buf(root, symlink_buf_hash);
 167
 168                 if (ret != 0) {
 169                         FREE(symlink_buf);
 170                         return ret;
 171                 }
 172                 DEBUG("Created symlink buf");
 173
 174                 struct lookup_table_entry *lte;
 175                 struct lookup_table_entry *existing_lte;
 176
 177                 existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
 178                 if (existing_lte) {
 179                         existing_lte->refcnt++;
 180                 } else {
 181                         DEBUG("Creating new lookup table entry");
 182                         lte = new_lookup_table_entry();
 183                         if (!lte) {
 184                                 FREE(symlink_buf);
 185                                 return WIMLIB_ERR_NOMEM;
 186                         }
 187                         lte->symlink_buf = symlink_buf;
 188                         lte->resource_entry.original_size = symlink_buf_len;
 189                         lte->resource_entry.size = symlink_buf_len;
 190                         lte->is_symlink = true;
 191                         memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
 192                         lookup_table_insert(lookup_table, lte);
 193                 }
 194         } else {
 195                 /* Regular file */
 196                 struct lookup_table_entry *lte;
 197
 198                 /* For each regular file, we must check to see if the file is in
 199                  * the lookup table already; if it is, we increment its refcnt;
 200                  * otherwise, we create a new lookup table entry and insert it.
 201                  * */
 202                 ret = sha1sum(root_disk_path, root->hash);
 203                 if (ret != 0)
 204                         return ret;
 205
 206                 lte = __lookup_resource(lookup_table, root->hash);
 207                 if (lte) {
 208                         lte->refcnt++;
 209                 } else {
 210                         char *file_on_disk = STRDUP(root_disk_path);
 211                         if (!file_on_disk) {
 212                                 ERROR("Failed to allocate memory for file path");
 213                                 return WIMLIB_ERR_NOMEM;
 214                         }
 215                         lte = new_lookup_table_entry();
 216                         if (!lte) {
 217                                 FREE(file_on_disk);
 218                                 return WIMLIB_ERR_NOMEM;
 219                         }
 220                         lte->file_on_disk = file_on_disk;
 221                         lte->resource_entry.original_size = root_stbuf.st_size;
 222                         lte->resource_entry.size = root_stbuf.st_size;
 223                         memcpy(lte->hash, root->hash, WIM_HASH_SIZE);
 224                         lookup_table_insert(lookup_table, lte);
 225                 }
 226         }
 227         return ret;
 228 }
 229
 230 struct wim_pair {
 231         WIMStruct *src_wim;
 232         WIMStruct *dest_wim;
 233 };
 234
 235 /*
 236  * This function takes in a dentry that was previously located only in image(s)
 237  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 238  * lookup table entry for this file in the lookup table of the destination WIM
 239  * file, we simply increment its reference count.  Otherwise, a new lookup table
 240  * entry is created that references the location of the file resource in the
 241  * source WIM file through the other_wim_fp field of the lookup table entry.
 242  */
 243 static int add_lookup_table_entry_to_dest_wim(struct dentry *dentry, void *arg)
 244 {
 245         WIMStruct *src_wim, *dest_wim;
 246         struct lookup_table_entry *src_table_entry;
 247         struct lookup_table_entry *dest_table_entry;
 248
 249         src_wim = ((struct wim_pair*)arg)->src_wim;
 250         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 251
 252         if (dentry_is_directory(dentry))
 253                 return 0;
 254
 255         /* XXX ADS */
 256         src_table_entry = __lookup_resource(src_wim->lookup_table, dentry->hash);
 257         if (!src_table_entry)
 258                 return 0;
 259
 260         /* XXX ADS */
 261         dest_table_entry = __lookup_resource(dest_wim->lookup_table, dentry->hash);
 262         if (dest_table_entry) {
 263                 dest_table_entry->refcnt++;
 264         } else {
 265                 dest_table_entry = new_lookup_table_entry();
 266                 if (!dest_table_entry)
 267                         return WIMLIB_ERR_NOMEM;
 268                 dest_table_entry->other_wim_fp = src_wim->fp;
 269                 dest_table_entry->other_wim_ctype =
 270                                 wimlib_get_compression_type(src_wim);
 271                 dest_table_entry->refcnt = 1;
 272                 memcpy(&dest_table_entry->resource_entry,
 273                        &src_table_entry->resource_entry,
 274                        sizeof(struct resource_entry));
 275                 memcpy(dest_table_entry->hash, dentry->hash, WIM_HASH_SIZE);
 276                 lookup_table_insert(dest_wim->lookup_table, dest_table_entry);
 277         }
 278         return 0;
 279 }
 280
 281 /*
 282  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 283  * file, adds an entry to the lookup table for the image metadata, updates the
 284  * image count in the header, and selects the new image.
 285  *
 286  * Does not update the XML data.
 287  *
 288  * @w:            The WIMStruct for the WIM file.
 289  * @root_dentry:  The root of the directory tree for the image.
 290  */
 291 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry)
 292 {
 293         struct lookup_table_entry *metadata_lte;
 294         struct image_metadata *imd;
 295         struct image_metadata *new_imd;
 296         struct wim_security_data *sd;
 297         struct link_group_table *lgt;
 298
 299         DEBUG("Reallocating image metadata array for image_count = %u",
 300               w->hdr.image_count + 1);
 301         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 302
 303         if (!imd) {
 304                 ERROR("Failed to allocate memory for new image metadata array");
 305                 return WIMLIB_ERR_NOMEM;
 306         }
 307
 308         memcpy(imd, w->image_metadata,
 309                w->hdr.image_count * sizeof(struct image_metadata));
 310
 311         metadata_lte = new_lookup_table_entry();
 312         if (!metadata_lte)
 313                 goto out_free_imd;
 314         sd = CALLOC(1, sizeof(struct wim_security_data));
 315         if (!sd)
 316                 goto out_free_metadata_lte;
 317         sd->refcnt = 1;
 318         sd->total_length = 8;
 319
 320         lgt = new_link_group_table(9001);
 321         if (!lgt)
 322                 goto out_free_security_data;
 323
 324         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 325         randomize_byte_array(metadata_lte->hash, WIM_HASH_SIZE);
 326         lookup_table_insert(w->lookup_table, metadata_lte);
 327
 328         new_imd = &imd[w->hdr.image_count];
 329
 330         new_imd->root_dentry    = root_dentry;
 331         new_imd->metadata_lte   = metadata_lte;
 332         new_imd->security_data  = sd;
 333         new_imd->lgt            = lgt;
 334         new_imd->modified       = true;
 335
 336         FREE(w->image_metadata);
 337         w->image_metadata       = imd;
 338         w->hdr.image_count++;
 339
 340         /* Change the current image to the new one. */
 341         return wimlib_select_image(w, w->hdr.image_count);
 342 out_free_security_data:
 343         FREE(sd);
 344 out_free_metadata_lte:
 345         FREE(metadata_lte);
 346 out_free_imd:
 347         FREE(imd);
 348         return WIMLIB_ERR_NOMEM;
 349
 350 }
 351
 352 /*
 353  * Copies an image, or all the images, from a WIM file, into another WIM file.
 354  */
 355 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 356                                   int src_image,
 357                                   WIMStruct *dest_wim,
 358                                   const char *dest_name,
 359                                   const char *dest_description,
 360                                   int flags)
 361 {
 362         int i;
 363         int ret;
 364         struct dentry *root;
 365         struct wim_pair wims;
 366
 367         if (src_image == WIM_ALL_IMAGES) {
 368                 if (src_wim->hdr.image_count > 1) {
 369
 370                         /* multi-image export. */
 371
 372                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 373                               (src_wim->hdr.boot_idx == 0))
 374                         {
 375                                 /* Specifying the boot flag on a multi-image
 376                                  * source WIM makes the boot index default to
 377                                  * the bootable image in the source WIM.  It is
 378                                  * an error if there is no such bootable image.
 379                                  * */
 380                                 ERROR("Cannot specify `boot' flag when "
 381                                       "exporting multiple images from a WIM "
 382                                       "with no bootable images");
 383                                 return WIMLIB_ERR_INVALID_PARAM;
 384                         }
 385                         if (dest_name || dest_description) {
 386                                 ERROR("Image name or image description was "
 387                                       "specified, but we are exporting "
 388                                       "multiple images");
 389                                 return WIMLIB_ERR_INVALID_PARAM;
 390                         }
 391                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 392                                 int export_flags = flags;
 393
 394                                 if (i != src_wim->hdr.boot_idx)
 395                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 396
 397                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 398                                                           NULL,
 399                                                           dest_description,
 400                                                           export_flags);
 401                                 if (ret != 0)
 402                                         return ret;
 403                         }
 404                         return 0;
 405                 } else {
 406                         src_image = 1;
 407                 }
 408         }
 409
 410         ret = wimlib_select_image(src_wim, src_image);
 411         if (ret != 0) {
 412                 ERROR("Could not select image %d from the WIM `%s' "
 413                       "to export it", src_image, src_wim->filename);
 414                 return ret;
 415         }
 416
 417         if (!dest_name) {
 418                 dest_name = wimlib_get_image_name(src_wim, src_image);
 419                 DEBUG("Using name `%s' for source image %d",
 420                       dest_name, src_image);
 421         }
 422
 423         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 424
 425         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 426                 ERROR("There is already an image named `%s' in the "
 427                       "destination WIM", dest_name);
 428                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 429         }
 430
 431
 432         /* Cleaning up here on failure would be hard.  For example, we could
 433          * fail to allocate memory in add_lookup_table_entry_to_dest_wim(),
 434          * leaving the lookup table entries in the destination WIM in an
 435          * inconsistent state.  Until these issues can be resolved,
 436          * wimlib_export_image() is documented as leaving dest_wim is an
 437          * indeterminate state.  */
 438         root = wim_root_dentry(src_wim);
 439         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 440         wims.src_wim = src_wim;
 441         wims.dest_wim = dest_wim;
 442         ret = for_dentry_in_tree(root, add_lookup_table_entry_to_dest_wim, &wims);
 443         if (ret != 0)
 444                 return ret;
 445         ret = add_new_dentry_tree(dest_wim, root);
 446         if (ret != 0)
 447                 return ret;
 448         /* Bring over old security data */
 449         struct wim_security_data *sd = wim_security_data(src_wim);
 450         struct image_metadata *new_imd = wim_get_current_image_metadata(dest_wim);
 451         wimlib_assert(sd);
 452         free_security_data(new_imd->security_data);
 453         new_imd->security_data = sd;
 454         sd->refcnt++;
 455
 456         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 457                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 458                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 459         }
 460
 461         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 462                                 dest_name, dest_description);
 463 }
 464
 465 /*
 466  * Deletes an image from the WIM.
 467  */
 468 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 469 {
 470         int num_images;
 471         int i;
 472         int ret;
 473
 474         if (image == WIM_ALL_IMAGES) {
 475                 num_images = w->hdr.image_count;
 476                 for (i = 1; i <= num_images; i++) {
 477                         /* Always delete the first image, since by the end
 478                          * there won't be any more than that!  */
 479                         ret = wimlib_delete_image(w, 1);
 480                         if (ret != 0)
 481                                 return ret;
 482                 }
 483                 return 0;
 484         }
 485
 486         DEBUG("Deleting image %d", image);
 487
 488         /* Even if the dentry tree is not allocated, we must select it (and
 489          * therefore allocate it) so that we can decrement the reference counts
 490          * in the lookup table.  */
 491         ret = wimlib_select_image(w, image);
 492         if (ret != 0)
 493                 return ret;
 494
 495         /* Free the dentry tree, any lookup table entries that have their
 496          * refcnt decremented to 0, and the security data. */
 497         destroy_image_metadata(wim_get_current_image_metadata(w),
 498                                w->lookup_table);
 499
 500         /* Get rid of the empty slot in the image metadata array. */
 501         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 502                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 503
 504         /* Decrement the image count. */
 505         if (--w->hdr.image_count == 0) {
 506                 FREE(w->image_metadata);
 507                 w->image_metadata = NULL;
 508         }
 509
 510         /* Fix the boot index. */
 511         if (w->hdr.boot_idx == image)
 512                 w->hdr.boot_idx = 0;
 513         else if (w->hdr.boot_idx > image)
 514                 w->hdr.boot_idx--;
 515
 516         w->current_image = WIM_NO_IMAGE;
 517
 518         /* Remove the image from the XML information. */
 519         xml_delete_image(&w->wim_info, image);
 520         return 0;
 521 }
 522
 523 /*
 524  * Adds an image to a WIM file from a directory tree on disk.
 525  */
 526 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 527                                const char *name, const char *description,
 528                                const char *flags_element, int flags)
 529 {
 530         struct dentry *root_dentry;
 531         struct image_metadata *imd;
 532         int ret;
 533
 534         DEBUG("Adding dentry tree from dir `%s'.", dir);
 535
 536         if (!name || !*name) {
 537                 ERROR("Must specify a non-empty string for the image name");
 538                 return WIMLIB_ERR_INVALID_PARAM;
 539         }
 540         if (!dir) {
 541                 ERROR("Must specify the name of a directory");
 542                 return WIMLIB_ERR_INVALID_PARAM;
 543         }
 544
 545         if (wimlib_image_name_in_use(w, name)) {
 546                 ERROR("There is already an image named \"%s\" in `%s'",
 547                       name, w->filename);
 548                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 549         }
 550
 551         DEBUG("Creating root dentry.");
 552
 553         root_dentry = new_dentry("");
 554         if (!root_dentry)
 555                 return WIMLIB_ERR_NOMEM;
 556         ret = calculate_dentry_full_path(root_dentry, NULL);
 557
 558         if (ret != 0)
 559                 goto out_free_dentry_tree;
 560
 561         root_dentry->attributes |= FILE_ATTRIBUTE_DIRECTORY;
 562
 563         DEBUG("Building dentry tree.");
 564         ret = build_dentry_tree(root_dentry, dir, w->lookup_table,
 565                                 flags | WIMLIB_ADD_IMAGE_FLAG_ROOT);
 566
 567         if (ret != 0) {
 568                 ERROR("Failed to build dentry tree for `%s'", dir);
 569                 goto out_free_dentry_tree;
 570         }
 571
 572         DEBUG("Recalculating full paths of dentries.");
 573         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 574         if (ret != 0)
 575                 goto out_free_dentry_tree;
 576
 577         ret = add_new_dentry_tree(w, root_dentry);
 578         if (ret != 0)
 579                 goto out_free_dentry_tree;
 580
 581         DEBUG("Inserting dentries into hard link group table");
 582         ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
 583                                  w->image_metadata[w->hdr.image_count - 1].lgt);
 584         if (ret != 0)
 585                 goto out_destroy_imd;
 586         DEBUG("Assigning hard link groups");
 587         assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
 588
 589         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 590                 wimlib_set_boot_idx(w, w->hdr.image_count);
 591
 592         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 593         if (ret != 0)
 594                 goto out_destroy_imd;
 595
 596         return 0;
 597 out_destroy_imd:
 598         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 599                                w->lookup_table);
 600         w->hdr.image_count--;
 601         return ret;
 602 out_free_dentry_tree:
 603         free_dentry_tree(root_dentry, w->lookup_table, true);
 604         return ret;
 605 }