wimlib.net Git - wimlib/blob - src/unix_apply.c

   1 /*
   2  * unix_apply.c - Code to apply files from a WIM image on UNIX.
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013 Eric Biggers
   7  *
   8  * This file is part of wimlib, a library for working with WIM files.
   9  *
  10  * wimlib is free software; you can redistribute it and/or modify it under the
  11  * terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 3 of the License, or (at your option)
  13  * any later version.
  14  *
  15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #include "config.h"
  25
  26 #ifdef HAVE_UTIME_H
  27 #  include <utime.h>
  28 #endif
  29 #include <dirent.h>
  30 #include <errno.h>
  31 #include <fcntl.h>
  32 #include <string.h>
  33 #include <sys/stat.h>
  34 #include <sys/time.h>
  35 #include <unistd.h>
  36
  37 #include "timestamp.h"
  38 #include "wimlib_internal.h"
  39 #include "lookup_table.h"
  40
  41 /* Returns the number of components of @path.  */
  42 static unsigned
  43 get_num_path_components(const char *path)
  44 {
  45         unsigned num_components = 0;
  46         while (*path) {
  47                 while (*path == '/')
  48                         path++;
  49                 if (*path)
  50                         num_components++;
  51                 while (*path && *path != '/')
  52                         path++;
  53         }
  54         return num_components;
  55 }
  56
  57 static const char *
  58 path_next_part(const char *path)
  59 {
  60         while (*path && *path != '/')
  61                 path++;
  62         while (*path && *path == '/')
  63                 path++;
  64         return path;
  65 }
  66
  67 static int
  68 unix_extract_regular_file_linked(struct wim_dentry *dentry,
  69                                  const char *output_path,
  70                                  struct apply_args *args,
  71                                  struct wim_lookup_table_entry *lte)
  72 {
  73         /* This mode overrides the normal hard-link extraction and
  74          * instead either symlinks or hardlinks *all* identical files in
  75          * the WIM, even if they are in a different image (in the case
  76          * of a multi-image extraction) */
  77
  78         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK) {
  79                 if (link(lte->extracted_file, output_path) != 0) {
  80                         ERROR_WITH_ERRNO("Failed to hard link "
  81                                          "`%s' to `%s'",
  82                                          output_path, lte->extracted_file);
  83                         return WIMLIB_ERR_LINK;
  84                 }
  85         } else {
  86                 int num_path_components;
  87                 int num_output_dir_path_components;
  88                 size_t extracted_file_len;
  89                 char *p;
  90                 const char *p2;
  91                 size_t i;
  92
  93                 num_path_components = get_num_path_components(dentry->_full_path) - 1;
  94                 num_output_dir_path_components = get_num_path_components(args->target);
  95
  96                 if (args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
  97                         num_path_components++;
  98                         num_output_dir_path_components--;
  99                 }
 100                 extracted_file_len = strlen(lte->extracted_file);
 101
 102                 char buf[extracted_file_len + 3 * num_path_components + 1];
 103                 p = &buf[0];
 104
 105                 for (i = 0; i < num_path_components; i++) {
 106                         *p++ = '.';
 107                         *p++ = '.';
 108                         *p++ = '/';
 109                 }
 110                 p2 = lte->extracted_file;
 111                 while (*p2 == '/')
 112                         p2++;
 113                 while (num_output_dir_path_components > 0) {
 114                         p2 = path_next_part(p2);
 115                         num_output_dir_path_components--;
 116                 }
 117                 strcpy(p, p2);
 118                 if (symlink(buf, output_path) != 0) {
 119                         ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 120                                          buf, lte->extracted_file);
 121                         return WIMLIB_ERR_LINK;
 122                 }
 123         }
 124         return 0;
 125 }
 126
 127 static int
 128 symlink_apply_unix_data(const char *link,
 129                         const struct wimlib_unix_data *unix_data)
 130 {
 131         if (lchown(link, unix_data->uid, unix_data->gid)) {
 132                 if (errno == EPERM) {
 133                         /* Ignore */
 134                         WARNING_WITH_ERRNO("failed to set symlink UNIX "
 135                                            "owner/group on \"%s\"", link);
 136                 } else {
 137                         ERROR_WITH_ERRNO("failed to set symlink UNIX "
 138                                          "owner/group on \"%s\"", link);
 139                         return WIMLIB_ERR_INVALID_DENTRY;
 140                 }
 141         }
 142         return 0;
 143 }
 144
 145 static int
 146 fd_apply_unix_data(int fd, const char *path,
 147                    const struct wimlib_unix_data *unix_data,
 148                    int extract_flags)
 149 {
 150         if (extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS)
 151                 return 0;
 152
 153         if (fchown(fd, unix_data->uid, unix_data->gid)) {
 154                 if (errno == EPERM &&
 155                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 156                 {
 157                         WARNING_WITH_ERRNO("failed to set file UNIX "
 158                                            "owner/group on \"%s\"", path);
 159                 } else {
 160                         ERROR_WITH_ERRNO("failed to set file UNIX "
 161                                          "owner/group on \"%s\"", path);
 162                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 163                                 WIMLIB_ERR_WRITE;
 164                 }
 165         }
 166
 167         if (fchmod(fd, unix_data->mode)) {
 168                 if (errno == EPERM &&
 169                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 170                 {
 171                         WARNING_WITH_ERRNO("failed to set UNIX file mode "
 172                                            "on \"%s\"", path);
 173                 } else {
 174                         ERROR_WITH_ERRNO("failed to set UNIX file mode "
 175                                          "on \"%s\"", path);
 176                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 177                                 WIMLIB_ERR_WRITE;
 178                 }
 179         }
 180         return 0;
 181 }
 182
 183 static int
 184 dir_apply_unix_data(const char *dir, const struct wimlib_unix_data *unix_data,
 185                     int extract_flags)
 186 {
 187         int dfd = open(dir, O_RDONLY);
 188         int ret;
 189         if (dfd >= 0) {
 190                 ret = fd_apply_unix_data(dfd, dir, unix_data, extract_flags);
 191                 if (close(dfd) && ret == 0) {
 192                         ERROR_WITH_ERRNO("can't close directory `%s'", dir);
 193                         ret = WIMLIB_ERR_WRITE;
 194                 }
 195         } else {
 196                 ERROR_WITH_ERRNO("can't open directory `%s'", dir);
 197                 ret = WIMLIB_ERR_OPENDIR;
 198         }
 199         return ret;
 200 }
 201
 202 static int
 203 unix_extract_regular_file_unlinked(struct wim_dentry *dentry,
 204                                    struct apply_args *args,
 205                                    const char *output_path,
 206                                    struct wim_lookup_table_entry *lte)
 207 {
 208         /* Normal mode of extraction.  Regular files and hard links are
 209          * extracted in the way that they appear in the WIM. */
 210
 211         int out_fd;
 212         int ret;
 213         struct wim_inode *inode = dentry->d_inode;
 214
 215         if (!((args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE)
 216                 && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 217                                      WIMLIB_EXTRACT_FLAG_HARDLINK))))
 218         {
 219                 /* If the dentry is part of a hard link set of at least 2
 220                  * dentries and one of the other dentries has already been
 221                  * extracted, make a hard link to the file corresponding to this
 222                  * already-extracted directory.  Otherwise, extract the file and
 223                  * set the inode->i_extracted_file field so that other dentries
 224                  * in the hard link group can link to it. */
 225                 if (inode->i_nlink > 1) {
 226                         if (inode->i_extracted_file) {
 227                                 DEBUG("Extracting hard link `%s' => `%s'",
 228                                       output_path, inode->i_extracted_file);
 229                                 if (link(inode->i_extracted_file, output_path) != 0) {
 230                                         ERROR_WITH_ERRNO("Failed to hard link "
 231                                                          "`%s' to `%s'",
 232                                                          output_path,
 233                                                          inode->i_extracted_file);
 234                                         return WIMLIB_ERR_LINK;
 235                                 }
 236                                 return 0;
 237                         }
 238                         FREE(inode->i_extracted_file);
 239                         inode->i_extracted_file = STRDUP(output_path);
 240                         if (!inode->i_extracted_file) {
 241                                 ERROR("Failed to allocate memory for filename");
 242                                 return WIMLIB_ERR_NOMEM;
 243                         }
 244                 }
 245         }
 246
 247         /* Extract the contents of the file to @output_path. */
 248
 249         out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 250         if (out_fd == -1) {
 251                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 252                                  output_path);
 253                 return WIMLIB_ERR_OPEN;
 254         }
 255
 256         if (!lte) {
 257                 /* Empty file with no lookup table entry */
 258                 DEBUG("Empty file `%s'.", output_path);
 259                 ret = 0;
 260                 goto out_extract_unix_data;
 261         }
 262
 263         ret = extract_wim_resource_to_fd(lte, out_fd, wim_resource_size(lte));
 264         if (ret) {
 265                 ERROR("Failed to extract resource to `%s'", output_path);
 266                 goto out;
 267         }
 268
 269 out_extract_unix_data:
 270         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 271                 struct wimlib_unix_data unix_data;
 272                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 273                 if (ret > 0)
 274                         ;
 275                 else if (ret < 0)
 276                         ret = 0;
 277                 else
 278                         ret = fd_apply_unix_data(out_fd, output_path, &unix_data,
 279                                                  args->extract_flags);
 280                 if (ret)
 281                         goto out;
 282         }
 283         if (lte)
 284                 args->progress.extract.completed_bytes += wim_resource_size(lte);
 285 out:
 286         if (close(out_fd) != 0) {
 287                 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
 288                 if (ret == 0)
 289                         ret = WIMLIB_ERR_WRITE;
 290         }
 291         return ret;
 292 }
 293
 294 static int
 295 unix_extract_regular_file(struct wim_dentry *dentry,
 296                           struct apply_args *args,
 297                           const char *output_path)
 298 {
 299         struct wim_lookup_table_entry *lte;
 300         const struct wim_inode *inode = dentry->d_inode;
 301
 302         lte = inode_unnamed_lte_resolved(inode);
 303
 304         if (lte && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 305                                            WIMLIB_EXTRACT_FLAG_HARDLINK)))
 306         {
 307                 if (lte->extracted_file) {
 308                         return unix_extract_regular_file_linked(dentry,
 309                                                                 output_path,
 310                                                                 args, lte);
 311                 } else {
 312                         lte->extracted_file = STRDUP(output_path);
 313                         if (!lte->extracted_file)
 314                                 return WIMLIB_ERR_NOMEM;
 315                 }
 316         }
 317         return unix_extract_regular_file_unlinked(dentry, args, output_path, lte);
 318 }
 319
 320 static int
 321 unix_extract_symlink(struct wim_dentry *dentry,
 322                      struct apply_args *args,
 323                      const char *output_path)
 324 {
 325         char target[4096 + args->target_realpath_len];
 326         char *fixed_target;
 327         const struct wim_inode *inode = dentry->d_inode;
 328
 329         ssize_t ret = wim_inode_readlink(inode,
 330                                          target + args->target_realpath_len,
 331                                          sizeof(target) - args->target_realpath_len - 1);
 332         struct wim_lookup_table_entry *lte;
 333
 334         if (ret <= 0) {
 335                 ERROR("Could not read the symbolic link from dentry `%s'",
 336                       dentry->_full_path);
 337                 return WIMLIB_ERR_INVALID_DENTRY;
 338         }
 339         target[args->target_realpath_len + ret] = '\0';
 340         if (target[args->target_realpath_len] == '/' &&
 341             args->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)
 342         {
 343                 /* Fix absolute symbolic link target to point into the actual
 344                  * extraction destination */
 345                 memcpy(target, args->target_realpath,
 346                        args->target_realpath_len);
 347                 fixed_target = target;
 348         } else {
 349                 /* Keep same link target */
 350                 fixed_target = target + args->target_realpath_len;
 351         }
 352         ret = symlink(fixed_target, output_path);
 353         if (ret) {
 354                 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 355                                  output_path, fixed_target);
 356                 return WIMLIB_ERR_LINK;
 357         }
 358         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 359                 struct wimlib_unix_data unix_data;
 360                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 361                 if (ret > 0)
 362                         ;
 363                 else if (ret < 0)
 364                         ret = 0;
 365                 else
 366                         ret = symlink_apply_unix_data(output_path, &unix_data);
 367                 if (ret)
 368                         return ret;
 369         }
 370         lte = inode_unnamed_lte_resolved(inode);
 371         wimlib_assert(lte != NULL);
 372         args->progress.extract.completed_bytes += wim_resource_size(lte);
 373         return 0;
 374 }
 375
 376 static int
 377 unix_extract_directory(struct wim_dentry *dentry, const tchar *output_path,
 378                        int extract_flags)
 379 {
 380         int ret;
 381         struct stat stbuf;
 382
 383         ret = tstat(output_path, &stbuf);
 384         if (ret == 0) {
 385                 if (S_ISDIR(stbuf.st_mode)) {
 386                         /*if (!is_root)*/
 387                                 /*WARNING("`%s' already exists", output_path);*/
 388                         goto dir_exists;
 389                 } else {
 390                         ERROR("`%"TS"' is not a directory", output_path);
 391                         return WIMLIB_ERR_MKDIR;
 392                 }
 393         } else {
 394                 if (errno != ENOENT) {
 395                         ERROR_WITH_ERRNO("Failed to stat `%"TS"'", output_path);
 396                         return WIMLIB_ERR_STAT;
 397                 }
 398         }
 399
 400         if (tmkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH))
 401         {
 402                 ERROR_WITH_ERRNO("Cannot create directory `%"TS"'", output_path);
 403                 return WIMLIB_ERR_MKDIR;
 404         }
 405 dir_exists:
 406         ret = 0;
 407 #ifndef __WIN32__
 408         if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 409                 struct wimlib_unix_data unix_data;
 410                 ret = inode_get_unix_data(dentry->d_inode, &unix_data, NULL);
 411                 if (ret > 0)
 412                         ;
 413                 else if (ret < 0)
 414                         ret = 0;
 415                 else
 416                         ret = dir_apply_unix_data(output_path, &unix_data,
 417                                                   extract_flags);
 418         }
 419 #endif
 420         return ret;
 421 }
 422
 423 int
 424 unix_do_apply_dentry(const char *output_path, size_t output_path_len,
 425                      struct wim_dentry *dentry, struct apply_args *args)
 426 {
 427         const struct wim_inode *inode = dentry->d_inode;
 428
 429         if (inode_is_symlink(inode))
 430                 return unix_extract_symlink(dentry, args, output_path);
 431         else if (inode_is_directory(inode))
 432                 return unix_extract_directory(dentry, output_path, args->extract_flags);
 433         else
 434                 return unix_extract_regular_file(dentry, args, output_path);
 435 }
 436
 437 int
 438 unix_do_apply_dentry_timestamps(const char *output_path,
 439                                 size_t output_path_len,
 440                                 struct wim_dentry *dentry,
 441                                 struct apply_args *args)
 442 {
 443         int ret;
 444         const struct wim_inode *inode = dentry->d_inode;
 445
 446 #ifdef HAVE_UTIMENSAT
 447         /* Convert the WIM timestamps, which are accurate to 100 nanoseconds,
 448          * into `struct timespec's for passing to utimensat(), which is accurate
 449          * to 1 nanosecond. */
 450
 451         struct timespec ts[2];
 452         ts[0] = wim_timestamp_to_timespec(inode->i_last_access_time);
 453         ts[1] = wim_timestamp_to_timespec(inode->i_last_write_time);
 454         ret = utimensat(AT_FDCWD, output_path, ts, AT_SYMLINK_NOFOLLOW);
 455         if (ret)
 456                 ret = errno;
 457 #else
 458         ret = ENOSYS;
 459 #endif
 460
 461         if (ret == ENOSYS) {
 462                 /* utimensat() not implemented or not available */
 463         #ifdef HAVE_LUTIMES
 464                 /* Convert the WIM timestamps, which are accurate to 100
 465                  * nanoseconds, into `struct timeval's for passing to lutimes(),
 466                  * which is accurate to 1 microsecond. */
 467                 struct timeval tv[2];
 468                 tv[0] = wim_timestamp_to_timeval(inode->i_last_access_time);
 469                 tv[1] = wim_timestamp_to_timeval(inode->i_last_write_time);
 470                 ret = lutimes(output_path, tv);
 471                 if (ret)
 472                         ret = errno;
 473         #endif
 474         }
 475
 476         if (ret == ENOSYS) {
 477                 /* utimensat() and lutimes() both not implemented or not
 478                  * available */
 479         #ifdef HAVE_UTIME
 480                 /* Convert the WIM timestamps, which are accurate to 100
 481                  * nanoseconds, into a `struct utimbuf's for passing to
 482                  * utime(), which is accurate to 1 second. */
 483                 struct utimbuf buf;
 484                 buf.actime = wim_timestamp_to_unix(inode->i_last_access_time);
 485                 buf.modtime = wim_timestamp_to_unix(inode->i_last_write_time);
 486                 ret = utime(output_path, &buf);
 487         #endif
 488         }
 489         if (ret && args->num_utime_warnings < 10) {
 490                 WARNING_WITH_ERRNO("Failed to set timestamp on file `%s'",
 491                                     output_path);
 492                 args->num_utime_warnings++;
 493         }
 494         return 0;
 495 }