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   1 /*
   2  * write.c
   3  *
   4  * Support for writing WIM files; write a WIM file, overwrite a WIM file, write
   5  * compressed file resources, etc.
   6  */
   7
   8 /*
   9  * Copyright (C) 2010 Carl Thijssen
  10  * Copyright (C) 2012 Eric Biggers
  11  *
  12  * This file is part of wimlib, a library for working with WIM files.
  13  *
  14  * wimlib is free software; you can redistribute it and/or modify it under the
  15  * terms of the GNU General Public License as published by the Free
  16  * Software Foundation; either version 3 of the License, or (at your option)
  17  * any later version.
  18  *
  19  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  20  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  21  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  22  * details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  26  */
  27
  28 #include "wimlib_internal.h"
  29 #include "io.h"
  30 #include "dentry.h"
  31 #include "lookup_table.h"
  32 #include "xml.h"
  33 #include <unistd.h>
  34
  35
  36 /* Reopens the FILE* for a WIM read-write. */
  37 static int reopen_rw(WIMStruct *w)
  38 {
  39         FILE *fp;
  40
  41         if (fclose(w->fp) != 0)
  42                 ERROR_WITH_ERRNO("Failed to close the file `%s'", w->filename);
  43         w->fp = NULL;
  44         fp = fopen(w->filename, "r+b");
  45         if (!fp) {
  46                 ERROR_WITH_ERRNO("Failed to open `%s' for reading and writing",
  47                                  w->filename);
  48                 return WIMLIB_ERR_OPEN;
  49         }
  50         w->fp = fp;
  51         return 0;
  52 }
  53
  54
  55
  56 /*
  57  * Writes a WIM file to the original file that it was read from, overwriting it.
  58  */
  59 WIMLIBAPI int wimlib_overwrite(WIMStruct *w, int write_flags)
  60 {
  61         const char *wimfile_name;
  62         size_t wim_name_len;
  63         int ret;
  64
  65         if (!w)
  66                 return WIMLIB_ERR_INVALID_PARAM;
  67
  68         write_flags &= ~WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE;
  69
  70         wimfile_name = w->filename;
  71
  72         DEBUG("Replacing WIM file `%s'.", wimfile_name);
  73
  74         if (!wimfile_name)
  75                 return WIMLIB_ERR_NO_FILENAME;
  76
  77         /* Write the WIM to a temporary file. */
  78         /* XXX should the temporary file be somewhere else? */
  79         wim_name_len = strlen(wimfile_name);
  80         char tmpfile[wim_name_len + 10];
  81         memcpy(tmpfile, wimfile_name, wim_name_len);
  82         randomize_char_array_with_alnum(tmpfile + wim_name_len, 9);
  83         tmpfile[wim_name_len + 9] = '\0';
  84
  85         ret = wimlib_write(w, tmpfile, WIM_ALL_IMAGES, write_flags);
  86         if (ret != 0) {
  87                 ERROR("Failed to write the WIM file `%s'", tmpfile);
  88                 return ret;
  89         }
  90
  91         DEBUG("Closing original WIM file.");
  92         /* Close the original WIM file that was opened for reading. */
  93         if (w->fp) {
  94                 if (fclose(w->fp) != 0) {
  95                         WARNING("Failed to close the file `%s'", wimfile_name);
  96                 }
  97                 w->fp = NULL;
  98         }
  99
 100         DEBUG("Renaming `%s' to `%s'", tmpfile, wimfile_name);
 101
 102         /* Rename the new file to the old file .*/
 103         if (rename(tmpfile, wimfile_name) != 0) {
 104                 ERROR_WITH_ERRNO("Failed to rename `%s' to `%s'",
 105                                  tmpfile, wimfile_name);
 106                 /* Remove temporary file. */
 107                 if (unlink(tmpfile) != 0)
 108                         ERROR_WITH_ERRNO("Failed to remove `%s'", tmpfile);
 109                 return WIMLIB_ERR_RENAME;
 110         }
 111
 112         return 0;
 113 }
 114
 115 static int check_resource_offset(struct lookup_table_entry *lte, void *arg)
 116 {
 117         u64 xml_data_offset = *(u64*)arg;
 118         if (lte->resource_entry.offset > xml_data_offset) {
 119                 ERROR("The following resource is *after* the XML data:");
 120                 print_lookup_table_entry(lte);
 121                 return WIMLIB_ERR_RESOURCE_ORDER;
 122         }
 123         return 0;
 124 }
 125
 126 WIMLIBAPI int wimlib_overwrite_xml_and_header(WIMStruct *w, int write_flags)
 127 {
 128         int ret;
 129         FILE *fp;
 130         u8 *integrity_table = NULL;
 131         off_t xml_end;
 132         off_t xml_size;
 133         size_t bytes_written;
 134
 135         DEBUG("Overwriting XML and header of `%s', write_flags = %#x",
 136               w->filename, write_flags);
 137
 138         if (!w->filename)
 139                 return WIMLIB_ERR_NO_FILENAME;
 140
 141         write_flags &= ~WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE;
 142
 143         /* Make sure that the integrity table (if present) is after the XML
 144          * data, and that there are no stream resources, metadata resources, or
 145          * lookup tables after the XML data.  Otherwise, these data would be
 146          * destroyed by this function. */
 147         if (w->hdr.integrity.offset != 0 &&
 148             w->hdr.integrity.offset < w->hdr.xml_res_entry.offset) {
 149                 ERROR("Didn't expect the integrity table to be before the XML data");
 150                 return WIMLIB_ERR_RESOURCE_ORDER;
 151         }
 152
 153         if (w->hdr.lookup_table_res_entry.offset >
 154             w->hdr.xml_res_entry.offset) {
 155                 ERROR("Didn't expect the lookup table to be after the XML data");
 156                 return WIMLIB_ERR_RESOURCE_ORDER;
 157         }
 158
 159         ret = for_lookup_table_entry(w->lookup_table, check_resource_offset,
 160                                      &w->hdr.xml_res_entry.offset);
 161         if (ret != 0)
 162                 return ret;
 163
 164         ret = reopen_rw(w);
 165         if (ret != 0)
 166                 return ret;
 167
 168         fp = w->fp;
 169
 170         /* The old integrity table is still OK, as the SHA1 message digests in
 171          * the integrity table include neither the header nor the XML data.
 172          * Save it for later if it exists and an integrity table was required.
 173          * */
 174         if ((write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY)
 175              && w->hdr.integrity.offset != 0)
 176         {
 177                 DEBUG("Reading existing integrity table.");
 178                 integrity_table = MALLOC(w->hdr.integrity.size);
 179                 if (!integrity_table)
 180                         return WIMLIB_ERR_NOMEM;
 181
 182                 ret = read_uncompressed_resource(fp, w->hdr.integrity.offset,
 183                                                  w->hdr.integrity.original_size,
 184                                                  integrity_table);
 185                 if (ret != 0)
 186                         goto err;
 187                 DEBUG("Done reading existing integrity table.");
 188         }
 189
 190         DEBUG("Overwriting XML data.");
 191         /* Overwrite the XML data. */
 192         if (fseeko(fp, w->hdr.xml_res_entry.offset, SEEK_SET) != 0) {
 193                 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" "
 194                                  "for XML data", w->hdr.xml_res_entry.offset);
 195                 ret = WIMLIB_ERR_WRITE;
 196                 goto err;
 197         }
 198         ret = write_xml_data(w->wim_info, WIM_ALL_IMAGES, fp, 0);
 199         if (ret != 0)
 200                 goto err;
 201
 202         DEBUG("Updating XML resource entry.");
 203         /* Update the XML resource entry in the WIM header. */
 204         xml_end = ftello(fp);
 205         if (xml_end == -1) {
 206                 ret = WIMLIB_ERR_WRITE;
 207                 goto err;
 208         }
 209         xml_size = xml_end - w->hdr.xml_res_entry.offset;
 210         w->hdr.xml_res_entry.size = xml_size;
 211         w->hdr.xml_res_entry.original_size = xml_size;
 212         /* XML data offset is unchanged. */
 213
 214         if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) {
 215                 DEBUG("Writing integrity table.");
 216                 w->hdr.integrity.offset = xml_end;
 217                 if (integrity_table) {
 218                         /* The existing integrity table was saved. */
 219                         bytes_written = fwrite(integrity_table, 1,
 220                                                w->hdr.integrity.size, fp);
 221                         if (bytes_written != w->hdr.integrity.size) {
 222                                 ERROR_WITH_ERRNO("Failed to write integrity "
 223                                                  "table");
 224                                 ret = WIMLIB_ERR_WRITE;
 225                                 goto err;
 226                         }
 227                         FREE(integrity_table);
 228                 } else {
 229                         /* There was no existing integrity table, so a new one
 230                          * must be calculated. */
 231                         ret = write_integrity_table(fp, WIM_HEADER_DISK_SIZE,
 232                                         w->hdr.lookup_table_res_entry.offset +
 233                                         w->hdr.lookup_table_res_entry.size,
 234                                         write_flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS);
 235                         if (ret != 0)
 236                                 return ret;
 237
 238                         off_t end_integrity = ftello(fp);
 239                         if (end_integrity == -1)
 240                                 return WIMLIB_ERR_WRITE;
 241
 242                         off_t integrity_size           = end_integrity - xml_end;
 243                         w->hdr.integrity.size          = integrity_size;
 244                         w->hdr.integrity.original_size = integrity_size;
 245                         w->hdr.integrity.flags         = 0;
 246                 }
 247         } else {
 248                 DEBUG("Truncating file to end of XML data.");
 249                 /* No integrity table to write.  The file should be truncated
 250                  * because it's possible that the old file was longer (due to it
 251                  * including an integrity table, or due to its XML data being
 252                  * longer) */
 253                 if (fflush(fp) != 0) {
 254                         ERROR_WITH_ERRNO("Failed to flush stream for file `%s'",
 255                                          w->filename);
 256                         return WIMLIB_ERR_WRITE;
 257                 }
 258                 if (ftruncate(fileno(fp), xml_end) != 0) {
 259                         ERROR_WITH_ERRNO("Failed to truncate `%s' to %"PRIu64" "
 260                                          "bytes", w->filename, xml_end);
 261                         return WIMLIB_ERR_WRITE;
 262                 }
 263                 memset(&w->hdr.integrity, 0, sizeof(struct resource_entry));
 264         }
 265
 266         DEBUG("Overwriting header.");
 267         /* Overwrite the header. */
 268         if (fseeko(fp, 0, SEEK_SET) != 0) {
 269                 ERROR_WITH_ERRNO("Failed to seek to beginning of `%s'",
 270                                  w->filename);
 271                 return WIMLIB_ERR_WRITE;
 272         }
 273
 274         ret = write_header(&w->hdr, fp);
 275         if (ret != 0)
 276                 return ret;
 277
 278         DEBUG("Closing `%s'.", w->filename);
 279         if (fclose(fp) != 0) {
 280                 ERROR_WITH_ERRNO("Failed to close `%s'", w->filename);
 281                 return WIMLIB_ERR_WRITE;
 282         }
 283         w->fp = NULL;
 284         DEBUG("Done.");
 285         return 0;
 286 err:
 287         FREE(integrity_table);
 288         return ret;
 289 }
 290
 291
 292 /* Write the file resources for the current image. */
 293 static int write_file_resources(WIMStruct *w)
 294 {
 295         DEBUG("Writing file resources for image %u.", w->current_image);
 296         return for_dentry_in_tree(wim_root_dentry(w), write_dentry_resources, w);
 297 }
 298
 299 /*
 300  * Write the lookup table, xml data, and integrity table, then overwrite the WIM
 301  * header.
 302  */
 303 int finish_write(WIMStruct *w, int image, int write_flags)
 304 {
 305         off_t lookup_table_offset;
 306         off_t xml_data_offset;
 307         off_t lookup_table_size;
 308         off_t integrity_offset;
 309         off_t xml_data_size;
 310         off_t end_offset;
 311         off_t integrity_size;
 312         int ret;
 313         struct wim_header hdr;
 314         FILE *out = w->out_fp;
 315
 316         if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) {
 317                 /* Write the lookup table. */
 318                 lookup_table_offset = ftello(out);
 319                 if (lookup_table_offset == -1)
 320                         return WIMLIB_ERR_WRITE;
 321
 322                 DEBUG("Writing lookup table (offset %"PRIu64")",
 323                       lookup_table_offset);
 324                 ret = write_lookup_table(w->lookup_table, out);
 325                 if (ret != 0)
 326                         return ret;
 327         }
 328
 329         xml_data_offset = ftello(out);
 330         if (xml_data_offset == -1)
 331                 return WIMLIB_ERR_WRITE;
 332
 333         /* @hdr will be the header for the new WIM.  First copy all the data
 334          * from the header in the WIMStruct; then set all the fields that may
 335          * have changed, including the resource entries, boot index, and image
 336          * count.  */
 337         memcpy(&hdr, &w->hdr, sizeof(struct wim_header));
 338         if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) {
 339                 lookup_table_size = xml_data_offset - lookup_table_offset;
 340                 hdr.lookup_table_res_entry.offset = lookup_table_offset;
 341                 hdr.lookup_table_res_entry.size = lookup_table_size;
 342         }
 343         hdr.lookup_table_res_entry.original_size = hdr.lookup_table_res_entry.size;
 344         hdr.lookup_table_res_entry.flags = WIM_RESHDR_FLAG_METADATA;
 345
 346         DEBUG("Writing XML data (offset %"PRIu64")", xml_data_offset);
 347         ret = write_xml_data(w->wim_info, image, out,
 348                              (write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE) ?
 349                                 wim_info_get_total_bytes(w->wim_info) : 0);
 350         if (ret != 0)
 351                 return ret;
 352
 353         integrity_offset = ftello(out);
 354         if (integrity_offset == -1)
 355                 return WIMLIB_ERR_WRITE;
 356         xml_data_size = integrity_offset - xml_data_offset;
 357
 358         hdr.xml_res_entry.offset                 = xml_data_offset;
 359         hdr.xml_res_entry.size                   = xml_data_size;
 360         hdr.xml_res_entry.original_size          = xml_data_size;
 361         hdr.xml_res_entry.flags                  = 0;
 362
 363         if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) {
 364                 ret = write_integrity_table(out, WIM_HEADER_DISK_SIZE,
 365                                             xml_data_offset,
 366                                             write_flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS);
 367                 if (ret != 0)
 368                         return ret;
 369                 end_offset = ftello(out);
 370                 if (end_offset == -1)
 371                         return WIMLIB_ERR_WRITE;
 372                 integrity_size              = end_offset - integrity_offset;
 373                 hdr.integrity.offset        = integrity_offset;
 374                 hdr.integrity.size          = integrity_size;
 375                 hdr.integrity.original_size = integrity_size;
 376         } else {
 377                 hdr.integrity.offset        = 0;
 378                 hdr.integrity.size          = 0;
 379                 hdr.integrity.original_size = 0;
 380         }
 381         hdr.integrity.flags = 0;
 382
 383         DEBUG("Updating WIM header.");
 384
 385         /*
 386          * In the WIM header, there is room for the resource entry for a
 387          * metadata resource labeled as the "boot metadata".  This entry should
 388          * be zeroed out if there is no bootable image (boot_idx 0).  Otherwise,
 389          * it should be a copy of the resource entry for the image that is
 390          * marked as bootable.  This is not well documented...
 391          */
 392         if (hdr.boot_idx == 0 || !w->image_metadata
 393                         || (image != WIM_ALL_IMAGES && image != hdr.boot_idx)) {
 394                 memset(&hdr.boot_metadata_res_entry, 0,
 395                        sizeof(struct resource_entry));
 396         } else {
 397                 memcpy(&hdr.boot_metadata_res_entry,
 398                        &w->image_metadata[
 399                           hdr.boot_idx - 1].metadata_lte->output_resource_entry,
 400                        sizeof(struct resource_entry));
 401         }
 402
 403         /* Set image count and boot index correctly for single image writes */
 404         if (image != WIM_ALL_IMAGES) {
 405                 hdr.image_count = 1;
 406                 if (hdr.boot_idx == image)
 407                         hdr.boot_idx = 1;
 408                 else
 409                         hdr.boot_idx = 0;
 410         }
 411
 412
 413         if (fseeko(out, 0, SEEK_SET) != 0)
 414                 return WIMLIB_ERR_WRITE;
 415
 416         return write_header(&hdr, out);
 417 }
 418
 419 /* Open file stream and write dummy header for WIM. */
 420 int begin_write(WIMStruct *w, const char *path, int write_flags)
 421 {
 422         const char *mode;
 423         DEBUG("Opening `%s' for new WIM", path);
 424
 425         /* checking the integrity requires going back over the file to read it.
 426          * XXX
 427          * (It also would be possible to keep a running sha1sum as the file is
 428          * written-- this would be faster, but a bit more complicated) */
 429         if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY)
 430                 mode = "w+b";
 431         else
 432                 mode = "wb";
 433
 434         w->out_fp = fopen(path, mode);
 435         if (!w->out_fp) {
 436                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 437                                  path);
 438                 return WIMLIB_ERR_OPEN;
 439         }
 440
 441         /* Write dummy header. It will be overwritten later. */
 442         return write_header(&w->hdr, w->out_fp);
 443 }
 444
 445 /* Writes a stand-alone WIM to a file.  */
 446 WIMLIBAPI int wimlib_write(WIMStruct *w, const char *path,
 447                            int image, int write_flags)
 448 {
 449         int ret;
 450
 451         if (!w || !path)
 452                 return WIMLIB_ERR_INVALID_PARAM;
 453
 454         write_flags &= ~WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE;
 455
 456         if (image != WIM_ALL_IMAGES &&
 457              (image < 1 || image > w->hdr.image_count))
 458                 return WIMLIB_ERR_INVALID_IMAGE;
 459
 460
 461         if (w->hdr.total_parts != 1) {
 462                 ERROR("Cannot call wimlib_write() on part of a split WIM");
 463                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 464         }
 465
 466         if (image == WIM_ALL_IMAGES)
 467                 DEBUG("Writing all images to `%s'.", path);
 468         else
 469                 DEBUG("Writing image %d to `%s'.", image, path);
 470
 471         ret = begin_write(w, path, write_flags);
 472         if (ret != 0)
 473                 goto out;
 474
 475         for_lookup_table_entry(w->lookup_table, lte_zero_out_refcnt, NULL);
 476
 477         w->write_flags = write_flags;
 478
 479         ret = for_image(w, image, write_file_resources);
 480         if (ret != 0) {
 481                 ERROR("Failed to write WIM file resources to `%s'", path);
 482                 goto out;
 483         }
 484
 485         ret = for_image(w, image, write_metadata_resource);
 486
 487         if (ret != 0) {
 488                 ERROR("Failed to write WIM image metadata to `%s'", path);
 489                 goto out;
 490         }
 491
 492         ret = finish_write(w, image, write_flags);
 493
 494 out:
 495         DEBUG("Closing output file.");
 496         if (w->out_fp != NULL) {
 497                 if (fclose(w->out_fp) != 0) {
 498                         ERROR_WITH_ERRNO("Failed to close the file `%s'", path);
 499                         ret = WIMLIB_ERR_WRITE;
 500                 }
 501                 w->out_fp = NULL;
 502         }
 503         return ret;
 504 }