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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 Lesser General Public License as published by the Free
  16  * Software Foundation; either version 2.1 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 Lesser General Public License for more
  22  * details.
  23  *
  24  * You should have received a copy of the GNU Lesser 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 /* Reopens the FILE* for a WIM read-write. */
  36 static int reopen_rw(WIMStruct *w)
  37 {
  38         FILE *fp;
  39
  40         if (fclose(w->fp) != 0)
  41                 ERROR_WITH_ERRNO("Failed to close the file `%s'", w->filename);
  42         fp = fopen(w->filename, "r+b");
  43         if (!fp) {
  44                 ERROR_WITH_ERRNO("Failed to open `%s' for reading and writing",
  45                                  w->filename);
  46                 return WIMLIB_ERR_OPEN;
  47         }
  48         w->fp = fp;
  49         return 0;
  50 }
  51
  52
  53
  54 /*
  55  * Writes a WIM file to the original file that it was read from, overwriting it.
  56  */
  57 WIMLIBAPI int wimlib_overwrite(WIMStruct *w, int flags)
  58 {
  59         const char *wimfile_name;
  60         size_t wim_name_len;
  61         int ret;
  62
  63         wimfile_name = w->filename;
  64
  65         DEBUG("Replacing WIM file `%s'.", wimfile_name);
  66
  67         if (!wimfile_name)
  68                 return WIMLIB_ERR_NO_FILENAME;
  69
  70         /* Write the WIM to a temporary file. */
  71         /* XXX should the temporary file be somewhere else? */
  72         wim_name_len = strlen(wimfile_name);
  73         char tmpfile[wim_name_len + 10];
  74         memcpy(tmpfile, wimfile_name, wim_name_len);
  75         randomize_char_array_with_alnum(tmpfile + wim_name_len, 9);
  76         tmpfile[wim_name_len + 9] = '\0';
  77
  78         ret = wimlib_write(w, tmpfile, WIM_ALL_IMAGES, flags);
  79         if (ret != 0) {
  80                 ERROR("Failed to write the WIM file `%s'", tmpfile);
  81                 return ret;
  82         }
  83
  84         DEBUG("Closing original WIM file.");
  85         /* Close the original WIM file that was opened for reading. */
  86         if (w->fp) {
  87                 if (fclose(w->fp) != 0) {
  88                         WARNING("Failed to close the file `%s'", wimfile_name);
  89                 }
  90                 w->fp = NULL;
  91         }
  92
  93         DEBUG("Renaming `%s' to `%s'", tmpfile, wimfile_name);
  94
  95         /* Rename the new file to the old file .*/
  96         if (rename(tmpfile, wimfile_name) != 0) {
  97                 ERROR_WITH_ERRNO("Failed to rename `%s' to `%s'",
  98                                  tmpfile, wimfile_name);
  99                 /* Remove temporary file. */
 100                 if (unlink(tmpfile) != 0)
 101                         ERROR_WITH_ERRNO("Failed to remove `%s'", tmpfile);
 102                 return WIMLIB_ERR_RENAME;
 103         }
 104
 105         return 0;
 106 }
 107
 108
 109 WIMLIBAPI int wimlib_overwrite_xml_and_header(WIMStruct *w, int flags)
 110 {
 111         int ret;
 112         FILE *fp;
 113         u8 *integrity_table = NULL;
 114         off_t xml_end;
 115         off_t xml_size;
 116         size_t bytes_written;
 117
 118         DEBUG("Overwriting XML and header of `%s', flags = %d",
 119               w->filename, flags);
 120         if (!w->filename)
 121                 return WIMLIB_ERR_NO_FILENAME;
 122
 123         ret = reopen_rw(w);
 124         if (ret != 0)
 125                 return ret;
 126
 127         fp = w->fp;
 128
 129         /* The old integrity table is still OK, as the SHA1 message digests in
 130          * the integrity table include neither the header nor the XML data.
 131          * Save it for later if it exists and an integrity table was required.
 132          * */
 133         if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY &&
 134                         w->hdr.integrity.offset != 0) {
 135                 DEBUG("Reading existing integrity table.");
 136                 integrity_table = MALLOC(w->hdr.integrity.size);
 137                 if (!integrity_table)
 138                         return WIMLIB_ERR_NOMEM;
 139
 140                 ret = read_uncompressed_resource(fp, w->hdr.integrity.offset,
 141                                                  w->hdr.integrity.original_size,
 142                                                  integrity_table);
 143                 if (ret != 0)
 144                         goto err;
 145                 DEBUG("Done reading existing integrity table.");
 146         }
 147
 148         DEBUG("Overwriting XML data.");
 149         /* Overwrite the XML data. */
 150         if (fseeko(fp, w->hdr.xml_res_entry.offset, SEEK_SET) != 0) {
 151                 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" "
 152                                  "for XML data", w->hdr.xml_res_entry.offset);
 153                 ret = WIMLIB_ERR_WRITE;
 154                 goto err;
 155         }
 156         ret = write_xml_data(w->wim_info, WIM_ALL_IMAGES, fp, 0);
 157         if (ret != 0)
 158                 goto err;
 159
 160         DEBUG("Updating XML resource entry.");
 161         /* Update the XML resource entry in the WIM header. */
 162         xml_end = ftello(fp);
 163         if (xml_end == -1) {
 164                 ret = WIMLIB_ERR_WRITE;
 165                 goto err;
 166         }
 167         xml_size = xml_end - w->hdr.xml_res_entry.offset;
 168         w->hdr.xml_res_entry.size = xml_size;
 169         w->hdr.xml_res_entry.original_size = xml_size;
 170
 171         if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) {
 172                 DEBUG("Writing integrity table.");
 173                 w->hdr.integrity.offset        = xml_end;
 174                 if (integrity_table) {
 175                         /* The existing integrity table was saved. */
 176                         bytes_written = fwrite(integrity_table, 1,
 177                                                w->hdr.integrity.size, fp);
 178                         if (bytes_written != w->hdr.integrity.size) {
 179                                 ERROR_WITH_ERRNO("Failed to write integrity "
 180                                                  "table");
 181                                 ret = WIMLIB_ERR_WRITE;
 182                                 goto err;
 183                         }
 184                         FREE(integrity_table);
 185                 } else {
 186                         /* There was no existing integrity table, so a new one
 187                          * must be calculated. */
 188                         ret = write_integrity_table(fp, WIM_HEADER_DISK_SIZE,
 189                                         w->hdr.lookup_table_res_entry.offset +
 190                                         w->hdr.lookup_table_res_entry.size,
 191                                         flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS);
 192                         if (ret != 0)
 193                                 goto err;
 194
 195                         off_t integrity_size           = ftello(fp) - xml_end;
 196                         w->hdr.integrity.size          = integrity_size;
 197                         w->hdr.integrity.original_size = integrity_size;
 198                         w->hdr.integrity.flags         = 0;
 199                 }
 200         } else {
 201                 DEBUG("Truncating file to end of XML data.");
 202                 /* No integrity table to write.  The file should be truncated
 203                  * because it's possible that the old file was longer (due to it
 204                  * including an integrity table, or due to its XML data being
 205                  * longer) */
 206                 if (fflush(fp) != 0) {
 207                         ERROR_WITH_ERRNO("Failed to flush stream for file `%s'",
 208                                          w->filename);
 209                         return WIMLIB_ERR_WRITE;
 210                 }
 211                 if (ftruncate(fileno(fp), xml_end) != 0) {
 212                         ERROR_WITH_ERRNO("Failed to truncate `%s' to %"PRIu64" "
 213                                          "bytes", w->filename, xml_end);
 214                         return WIMLIB_ERR_WRITE;
 215                 }
 216                 memset(&w->hdr.integrity, 0, sizeof(struct resource_entry));
 217         }
 218
 219         DEBUG("Overwriting header.");
 220         /* Overwrite the header. */
 221         if (fseeko(fp, 0, SEEK_SET) != 0) {
 222                 ERROR_WITH_ERRNO("Failed to seek to beginning of `%s'",
 223                                  w->filename);
 224                 return WIMLIB_ERR_WRITE;
 225         }
 226
 227         ret = write_header(&w->hdr, fp);
 228         if (ret != 0)
 229                 return ret;
 230
 231         DEBUG("Closing `%s'.", w->filename);
 232         if (fclose(fp) != 0) {
 233                 ERROR_WITH_ERRNO("Failed to close `%s'", w->filename);
 234                 return WIMLIB_ERR_WRITE;
 235         }
 236         w->fp = NULL;
 237         DEBUG("Done.");
 238         return 0;
 239 err:
 240         FREE(integrity_table);
 241         return ret;
 242 }
 243
 244
 245 /* Write the file resources for the current image. */
 246 static int write_file_resources(WIMStruct *w)
 247 {
 248
 249         DEBUG("Writing file resources for image %u.", w->current_image);
 250         return for_dentry_in_tree(wim_root_dentry(w), write_dentry_resources, w);
 251 }
 252
 253 /* Write the lookup table, xml data, and integrity table, then overwrite the WIM
 254  * header.
 255  *
 256  * write_lt is zero iff the lookup table is not to be written; i.e. it is
 257  * handled elsewhere. */
 258 int finish_write(WIMStruct *w, int image, int flags, int write_lt)
 259 {
 260         off_t lookup_table_offset;
 261         off_t xml_data_offset;
 262         off_t lookup_table_size;
 263         off_t integrity_offset;
 264         off_t xml_data_size;
 265         off_t end_offset;
 266         off_t integrity_size;
 267         int ret;
 268         struct wim_header hdr;
 269         FILE *out = w->out_fp;
 270
 271         if (write_lt) {
 272                 lookup_table_offset = ftello(out);
 273                 if (lookup_table_offset == -1)
 274                         return WIMLIB_ERR_WRITE;
 275
 276                 DEBUG("Writing lookup table (offset %"PRIu64")", lookup_table_offset);
 277                 /* Write the lookup table. */
 278                 ret = write_lookup_table(w->lookup_table, out);
 279                 if (ret != 0)
 280                         return ret;
 281         }
 282
 283
 284         xml_data_offset = ftello(out);
 285         if (xml_data_offset == -1)
 286                 return WIMLIB_ERR_WRITE;
 287         DEBUG("Writing XML data (offset %"PRIu64")", xml_data_offset);
 288
 289         /* @hdr will be the header for the new WIM.  First copy all the data
 290          * from the header in the WIMStruct; then set all the fields that may
 291          * have changed, including the resource entries, boot index, and image
 292          * count.  */
 293         memcpy(&hdr, &w->hdr, sizeof(struct wim_header));
 294         if (write_lt) {
 295                 lookup_table_size = xml_data_offset - lookup_table_offset;
 296                 hdr.lookup_table_res_entry.offset        = lookup_table_offset;
 297                 hdr.lookup_table_res_entry.size          = lookup_table_size;
 298         }
 299         hdr.lookup_table_res_entry.original_size = hdr.lookup_table_res_entry.size;
 300         hdr.lookup_table_res_entry.flags         = WIM_RESHDR_FLAG_METADATA;
 301
 302         ret = write_xml_data(w->wim_info, image, out,
 303                              write_lt ? 0 : wim_info_get_total_bytes(w->wim_info));
 304         if (ret != 0)
 305                 return ret;
 306
 307         integrity_offset = ftello(out);
 308         if (integrity_offset == -1)
 309                 return WIMLIB_ERR_WRITE;
 310         xml_data_size = integrity_offset - xml_data_offset;
 311
 312         hdr.xml_res_entry.offset                 = xml_data_offset;
 313         hdr.xml_res_entry.size                   = xml_data_size;
 314         hdr.xml_res_entry.original_size          = xml_data_size;
 315         hdr.xml_res_entry.flags                  = 0;
 316
 317         if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) {
 318                 ret = write_integrity_table(out, WIM_HEADER_DISK_SIZE,
 319                                             xml_data_offset,
 320                                             flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS);
 321                 if (ret != 0)
 322                         return ret;
 323                 end_offset = ftello(out);
 324                 if (end_offset == -1)
 325                         return WIMLIB_ERR_WRITE;
 326                 integrity_size = end_offset - integrity_offset;
 327                 hdr.integrity.offset = integrity_offset;
 328                 hdr.integrity.size   = integrity_size;
 329                 hdr.integrity.original_size = integrity_size;
 330         } else {
 331                 hdr.integrity.offset        = 0;
 332                 hdr.integrity.size          = 0;
 333                 hdr.integrity.original_size = 0;
 334         }
 335         hdr.integrity.flags = 0;
 336
 337         DEBUG("Updating WIM header.");
 338
 339         /*
 340          * In the WIM header, there is room for the resource entry for a
 341          * metadata resource labeled as the "boot metadata".  This entry should
 342          * be zeroed out if there is no bootable image (boot_idx 0).  Otherwise,
 343          * it should be a copy of the resource entry for the image that is
 344          * marked as bootable.  This is not well documented...
 345          */
 346         if (hdr.boot_idx == 0 || !w->image_metadata
 347                         || (image != WIM_ALL_IMAGES && image != hdr.boot_idx)) {
 348                 memset(&hdr.boot_metadata_res_entry, 0,
 349                        sizeof(struct resource_entry));
 350         } else {
 351                 memcpy(&hdr.boot_metadata_res_entry,
 352                        &w->image_metadata[
 353                           hdr.boot_idx - 1].metadata_lte->output_resource_entry,
 354                        sizeof(struct resource_entry));
 355         }
 356
 357         /* Set image count and boot index correctly for single image writes */
 358         if (image != WIM_ALL_IMAGES) {
 359                 hdr.image_count = 1;
 360                 if (hdr.boot_idx == image)
 361                         hdr.boot_idx = 1;
 362                 else
 363                         hdr.boot_idx = 0;
 364         }
 365
 366
 367         if (fseeko(out, 0, SEEK_SET) != 0)
 368                 return WIMLIB_ERR_WRITE;
 369
 370         return write_header(&hdr, out);
 371 }
 372
 373 /* Open file stream and write dummy header for WIM. */
 374 int begin_write(WIMStruct *w, const char *path, int flags)
 375 {
 376         const char *mode;
 377         DEBUG("Opening `%s' for new WIM", path);
 378
 379         /* checking the integrity requires going back over the file to read it.
 380          * XXX
 381          * (It also would be possible to keep a running sha1sum as the file
 382          * as written-- this would be faster, but a bit more complicated) */
 383         if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY)
 384                 mode = "w+b";
 385         else
 386                 mode = "wb";
 387
 388         w->out_fp = fopen(path, mode);
 389         if (!w->out_fp) {
 390                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 391                                  path);
 392                 return WIMLIB_ERR_OPEN;
 393         }
 394
 395         /* Write dummy header. It will be overwritten later. */
 396         return write_header(&w->hdr, w->out_fp);
 397 }
 398
 399 /* Writes the WIM to a file.  */
 400 WIMLIBAPI int wimlib_write(WIMStruct *w, const char *path, int image, int flags)
 401 {
 402         int ret;
 403
 404         if (image != WIM_ALL_IMAGES &&
 405              (image < 1 || image > w->hdr.image_count))
 406                 return WIMLIB_ERR_INVALID_IMAGE;
 407
 408         if (image == WIM_ALL_IMAGES)
 409                 DEBUG("Writing all images to `%s'.", path);
 410         else
 411                 DEBUG("Writing image %d to `%s'.", image, path);
 412
 413         ret = begin_write(w, path, flags);
 414         if (ret != 0)
 415                 goto done;
 416
 417         for_lookup_table_entry(w->lookup_table, zero_out_refcnts, NULL);
 418
 419         ret = for_image(w, image, write_file_resources);
 420         if (ret != 0) {
 421                 ERROR("Failed to write WIM file resources to `%s'", path);
 422                 goto done;
 423         }
 424
 425         ret = for_image(w, image, write_metadata_resource);
 426
 427         if (ret != 0) {
 428                 ERROR("Failed to write WIM image metadata to `%s'", path);
 429                 goto done;
 430         }
 431
 432         ret = finish_write(w, image, flags, 1);
 433
 434 done:
 435         DEBUG("Closing output file.");
 436         if (w->out_fp != NULL) {
 437                 if (fclose(w->out_fp) != 0) {
 438                         ERROR_WITH_ERRNO("Failed to close the file `%s'", path);
 439                         ret = WIMLIB_ERR_WRITE;
 440                 }
 441                 w->out_fp = NULL;
 442         }
 443         return ret;
 444 }