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   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 #ifndef __WIN32__
  25
  26 #ifdef HAVE_CONFIG_H
  27 #  include "config.h"
  28 #endif
  29
  30 #include <dirent.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <string.h>
  34 #include <sys/stat.h>
  35 #include <sys/time.h>
  36 #include <unistd.h>
  37 #ifdef HAVE_UTIME_H
  38 #  include <utime.h>
  39 #endif
  40
  41 #include "wimlib/apply.h"
  42 #include "wimlib/error.h"
  43 #include "wimlib/lookup_table.h"
  44 #include "wimlib/reparse.h"
  45 #include "wimlib/timestamp.h"
  46
  47 /* Returns the number of components of @path.  */
  48 static unsigned
  49 get_num_path_components(const char *path)
  50 {
  51         unsigned num_components = 0;
  52         while (*path) {
  53                 while (*path == '/')
  54                         path++;
  55                 if (*path)
  56                         num_components++;
  57                 while (*path && *path != '/')
  58                         path++;
  59         }
  60         return num_components;
  61 }
  62
  63 static const char *
  64 path_next_part(const char *path)
  65 {
  66         while (*path && *path != '/')
  67                 path++;
  68         while (*path && *path == '/')
  69                 path++;
  70         return path;
  71 }
  72
  73 static int
  74 unix_extract_regular_file_linked(struct wim_dentry *dentry,
  75                                  const char *output_path,
  76                                  struct apply_args *args,
  77                                  struct wim_lookup_table_entry *lte)
  78 {
  79         /* This mode overrides the normal hard-link extraction and
  80          * instead either symlinks or hardlinks *all* identical files in
  81          * the WIM, even if they are in a different image (in the case
  82          * of a multi-image extraction) */
  83
  84         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK) {
  85                 if (link(lte->extracted_file, output_path) != 0) {
  86                         ERROR_WITH_ERRNO("Failed to hard link "
  87                                          "`%s' to `%s'",
  88                                          output_path, lte->extracted_file);
  89                         return WIMLIB_ERR_LINK;
  90                 }
  91         } else {
  92                 int num_path_components;
  93                 int num_output_dir_path_components;
  94                 size_t extracted_file_len;
  95                 char *p;
  96                 const char *p2;
  97                 size_t i;
  98
  99                 num_path_components = get_num_path_components(dentry->_full_path) - 1;
 100                 num_output_dir_path_components = get_num_path_components(args->target);
 101
 102                 if (args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
 103                         num_path_components++;
 104                         num_output_dir_path_components--;
 105                 }
 106                 extracted_file_len = strlen(lte->extracted_file);
 107
 108                 char buf[extracted_file_len + 3 * num_path_components + 1];
 109                 p = &buf[0];
 110
 111                 for (i = 0; i < num_path_components; i++) {
 112                         *p++ = '.';
 113                         *p++ = '.';
 114                         *p++ = '/';
 115                 }
 116                 p2 = lte->extracted_file;
 117                 while (*p2 == '/')
 118                         p2++;
 119                 while (num_output_dir_path_components > 0) {
 120                         p2 = path_next_part(p2);
 121                         num_output_dir_path_components--;
 122                 }
 123                 strcpy(p, p2);
 124                 if (symlink(buf, output_path) != 0) {
 125                         ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 126                                          buf, lte->extracted_file);
 127                         return WIMLIB_ERR_LINK;
 128                 }
 129         }
 130         return 0;
 131 }
 132
 133 static int
 134 symlink_apply_unix_data(const char *link,
 135                         const struct wimlib_unix_data *unix_data)
 136 {
 137         if (lchown(link, unix_data->uid, unix_data->gid)) {
 138                 if (errno == EPERM) {
 139                         /* Ignore */
 140                         WARNING_WITH_ERRNO("failed to set symlink UNIX "
 141                                            "owner/group on \"%s\"", link);
 142                 } else {
 143                         ERROR_WITH_ERRNO("failed to set symlink UNIX "
 144                                          "owner/group on \"%s\"", link);
 145                         return WIMLIB_ERR_INVALID_DENTRY;
 146                 }
 147         }
 148         return 0;
 149 }
 150
 151 static int
 152 fd_apply_unix_data(int fd, const char *path,
 153                    const struct wimlib_unix_data *unix_data,
 154                    int extract_flags)
 155 {
 156         if (extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS)
 157                 return 0;
 158
 159         if (fchown(fd, unix_data->uid, unix_data->gid)) {
 160                 if (errno == EPERM &&
 161                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 162                 {
 163                         WARNING_WITH_ERRNO("failed to set file UNIX "
 164                                            "owner/group on \"%s\"", path);
 165                 } else {
 166                         ERROR_WITH_ERRNO("failed to set file UNIX "
 167                                          "owner/group on \"%s\"", path);
 168                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 169                                 WIMLIB_ERR_WRITE;
 170                 }
 171         }
 172
 173         if (fchmod(fd, unix_data->mode)) {
 174                 if (errno == EPERM &&
 175                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 176                 {
 177                         WARNING_WITH_ERRNO("failed to set UNIX file mode "
 178                                            "on \"%s\"", path);
 179                 } else {
 180                         ERROR_WITH_ERRNO("failed to set UNIX file mode "
 181                                          "on \"%s\"", path);
 182                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 183                                 WIMLIB_ERR_WRITE;
 184                 }
 185         }
 186         return 0;
 187 }
 188
 189 static int
 190 dir_apply_unix_data(const char *dir, const struct wimlib_unix_data *unix_data,
 191                     int extract_flags)
 192 {
 193         int dfd = open(dir, O_RDONLY);
 194         int ret;
 195         if (dfd >= 0) {
 196                 ret = fd_apply_unix_data(dfd, dir, unix_data, extract_flags);
 197                 if (close(dfd) && ret == 0) {
 198                         ERROR_WITH_ERRNO("can't close directory `%s'", dir);
 199                         ret = WIMLIB_ERR_WRITE;
 200                 }
 201         } else {
 202                 ERROR_WITH_ERRNO("can't open directory `%s'", dir);
 203                 ret = WIMLIB_ERR_OPENDIR;
 204         }
 205         return ret;
 206 }
 207
 208 static int
 209 unix_extract_regular_file_unlinked(struct wim_dentry *dentry,
 210                                    struct apply_args *args,
 211                                    const char *output_path,
 212                                    struct wim_lookup_table_entry *lte)
 213 {
 214         /* Normal mode of extraction.  Regular files and hard links are
 215          * extracted in the way that they appear in the WIM. */
 216
 217         int out_fd;
 218         int ret;
 219         struct wim_inode *inode = dentry->d_inode;
 220
 221         if (!((args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE)
 222                 && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 223                                      WIMLIB_EXTRACT_FLAG_HARDLINK))))
 224         {
 225                 /* If the dentry is part of a hard link set of at least 2
 226                  * dentries and one of the other dentries has already been
 227                  * extracted, make a hard link to the file corresponding to this
 228                  * already-extracted directory.  Otherwise, extract the file and
 229                  * set the inode->i_extracted_file field so that other dentries
 230                  * in the hard link group can link to it. */
 231                 if (inode->i_nlink > 1) {
 232                         if (inode->i_extracted_file) {
 233                                 DEBUG("Extracting hard link `%s' => `%s'",
 234                                       output_path, inode->i_extracted_file);
 235                                 if (link(inode->i_extracted_file, output_path) != 0) {
 236                                         ERROR_WITH_ERRNO("Failed to hard link "
 237                                                          "`%s' to `%s'",
 238                                                          output_path,
 239                                                          inode->i_extracted_file);
 240                                         return WIMLIB_ERR_LINK;
 241                                 }
 242                                 return 0;
 243                         }
 244                         FREE(inode->i_extracted_file);
 245                         inode->i_extracted_file = STRDUP(output_path);
 246                         if (!inode->i_extracted_file) {
 247                                 ERROR("Failed to allocate memory for filename");
 248                                 return WIMLIB_ERR_NOMEM;
 249                         }
 250                 }
 251         }
 252
 253         /* Extract the contents of the file to @output_path. */
 254
 255         out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 256         if (out_fd == -1) {
 257                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 258                                  output_path);
 259                 return WIMLIB_ERR_OPEN;
 260         }
 261
 262         if (!lte) {
 263                 /* Empty file with no lookup table entry */
 264                 DEBUG("Empty file `%s'.", output_path);
 265                 ret = 0;
 266                 goto out_extract_unix_data;
 267         }
 268
 269         ret = extract_wim_resource_to_fd(lte, out_fd, wim_resource_size(lte));
 270         if (ret) {
 271                 ERROR("Failed to extract resource to `%s'", output_path);
 272                 goto out;
 273         }
 274
 275 out_extract_unix_data:
 276         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 277                 struct wimlib_unix_data unix_data;
 278                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 279                 if (ret > 0)
 280                         ;
 281                 else if (ret < 0)
 282                         ret = 0;
 283                 else
 284                         ret = fd_apply_unix_data(out_fd, output_path, &unix_data,
 285                                                  args->extract_flags);
 286                 if (ret)
 287                         goto out;
 288         }
 289         if (lte)
 290                 args->progress.extract.completed_bytes += wim_resource_size(lte);
 291 out:
 292         if (close(out_fd) != 0) {
 293                 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
 294                 if (ret == 0)
 295                         ret = WIMLIB_ERR_WRITE;
 296         }
 297         return ret;
 298 }
 299
 300 static int
 301 unix_extract_regular_file(struct wim_dentry *dentry,
 302                           struct apply_args *args,
 303                           const char *output_path)
 304 {
 305         struct wim_lookup_table_entry *lte;
 306         const struct wim_inode *inode = dentry->d_inode;
 307
 308         lte = inode_unnamed_lte_resolved(inode);
 309
 310         if (lte && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 311                                            WIMLIB_EXTRACT_FLAG_HARDLINK)))
 312         {
 313                 if (lte->extracted_file) {
 314                         return unix_extract_regular_file_linked(dentry,
 315                                                                 output_path,
 316                                                                 args, lte);
 317                 } else {
 318                         lte->extracted_file = STRDUP(output_path);
 319                         if (!lte->extracted_file)
 320                                 return WIMLIB_ERR_NOMEM;
 321                 }
 322         }
 323         return unix_extract_regular_file_unlinked(dentry, args, output_path, lte);
 324 }
 325
 326 static int
 327 unix_extract_symlink(struct wim_dentry *dentry,
 328                      struct apply_args *args,
 329                      const char *output_path)
 330 {
 331         char target[4096 + args->target_realpath_len];
 332         char *fixed_target;
 333         const struct wim_inode *inode = dentry->d_inode;
 334
 335         ssize_t ret = wim_inode_readlink(inode,
 336                                          target + args->target_realpath_len,
 337                                          sizeof(target) - args->target_realpath_len - 1);
 338         struct wim_lookup_table_entry *lte;
 339
 340         if (ret <= 0) {
 341                 ERROR("Could not read the symbolic link from dentry `%s'",
 342                       dentry->_full_path);
 343                 return WIMLIB_ERR_INVALID_DENTRY;
 344         }
 345         target[args->target_realpath_len + ret] = '\0';
 346         if (target[args->target_realpath_len] == '/' &&
 347             args->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)
 348         {
 349                 /* Fix absolute symbolic link target to point into the actual
 350                  * extraction destination */
 351                 memcpy(target, args->target_realpath,
 352                        args->target_realpath_len);
 353                 fixed_target = target;
 354         } else {
 355                 /* Keep same link target */
 356                 fixed_target = target + args->target_realpath_len;
 357         }
 358         ret = symlink(fixed_target, output_path);
 359         if (ret) {
 360                 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 361                                  output_path, fixed_target);
 362                 return WIMLIB_ERR_LINK;
 363         }
 364         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 365                 struct wimlib_unix_data unix_data;
 366                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 367                 if (ret > 0)
 368                         ;
 369                 else if (ret < 0)
 370                         ret = 0;
 371                 else
 372                         ret = symlink_apply_unix_data(output_path, &unix_data);
 373                 if (ret)
 374                         return ret;
 375         }
 376         lte = inode_unnamed_lte_resolved(inode);
 377         wimlib_assert(lte != NULL);
 378         args->progress.extract.completed_bytes += wim_resource_size(lte);
 379         return 0;
 380 }
 381
 382 static int
 383 unix_extract_directory(struct wim_dentry *dentry, const tchar *output_path,
 384                        int extract_flags)
 385 {
 386         int ret;
 387         struct stat stbuf;
 388
 389         ret = tstat(output_path, &stbuf);
 390         if (ret == 0) {
 391                 if (S_ISDIR(stbuf.st_mode)) {
 392                         goto dir_exists;
 393                 } else {
 394                         ERROR("`%"TS"' is not a directory", output_path);
 395                         return WIMLIB_ERR_MKDIR;
 396                 }
 397         } else {
 398                 if (errno != ENOENT) {
 399                         ERROR_WITH_ERRNO("Failed to stat `%"TS"'", output_path);
 400                         return WIMLIB_ERR_STAT;
 401                 }
 402         }
 403
 404         if (tmkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH))
 405         {
 406                 ERROR_WITH_ERRNO("Cannot create directory `%"TS"'", output_path);
 407                 return WIMLIB_ERR_MKDIR;
 408         }
 409 dir_exists:
 410         ret = 0;
 411 #ifndef __WIN32__
 412         if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 413                 struct wimlib_unix_data unix_data;
 414                 ret = inode_get_unix_data(dentry->d_inode, &unix_data, NULL);
 415                 if (ret > 0)
 416                         ;
 417                 else if (ret < 0)
 418                         ret = 0;
 419                 else
 420                         ret = dir_apply_unix_data(output_path, &unix_data,
 421                                                   extract_flags);
 422         }
 423 #endif
 424         return ret;
 425 }
 426
 427 int
 428 unix_do_apply_dentry(const char *output_path, size_t output_path_len,
 429                      struct wim_dentry *dentry, struct apply_args *args)
 430 {
 431         const struct wim_inode *inode = dentry->d_inode;
 432
 433         if (inode_is_symlink(inode))
 434                 return unix_extract_symlink(dentry, args, output_path);
 435         else if (inode_is_directory(inode))
 436                 return unix_extract_directory(dentry, output_path, args->extract_flags);
 437         else
 438                 return unix_extract_regular_file(dentry, args, output_path);
 439 }
 440
 441 int
 442 unix_do_apply_dentry_timestamps(const char *output_path,
 443                                 size_t output_path_len,
 444                                 struct wim_dentry *dentry,
 445                                 struct apply_args *args)
 446 {
 447         int ret;
 448         const struct wim_inode *inode = dentry->d_inode;
 449
 450 #ifdef HAVE_UTIMENSAT
 451         /* Convert the WIM timestamps, which are accurate to 100 nanoseconds,
 452          * into `struct timespec's for passing to utimensat(), which is accurate
 453          * to 1 nanosecond. */
 454
 455         struct timespec ts[2];
 456         ts[0] = wim_timestamp_to_timespec(inode->i_last_access_time);
 457         ts[1] = wim_timestamp_to_timespec(inode->i_last_write_time);
 458         ret = utimensat(AT_FDCWD, output_path, ts, AT_SYMLINK_NOFOLLOW);
 459         if (ret)
 460                 ret = errno;
 461 #else
 462         ret = ENOSYS;
 463 #endif
 464
 465         if (ret == ENOSYS) {
 466                 /* utimensat() not implemented or not available */
 467         #ifdef HAVE_LUTIMES
 468                 /* Convert the WIM timestamps, which are accurate to 100
 469                  * nanoseconds, into `struct timeval's for passing to lutimes(),
 470                  * which is accurate to 1 microsecond. */
 471                 struct timeval tv[2];
 472                 tv[0] = wim_timestamp_to_timeval(inode->i_last_access_time);
 473                 tv[1] = wim_timestamp_to_timeval(inode->i_last_write_time);
 474                 ret = lutimes(output_path, tv);
 475                 if (ret)
 476                         ret = errno;
 477         #endif
 478         }
 479
 480         if (ret == ENOSYS) {
 481                 /* utimensat() and lutimes() both not implemented or not
 482                  * available */
 483         #ifdef HAVE_UTIME
 484                 /* Convert the WIM timestamps, which are accurate to 100
 485                  * nanoseconds, into a `struct utimbuf's for passing to
 486                  * utime(), which is accurate to 1 second. */
 487                 struct utimbuf buf;
 488                 buf.actime = wim_timestamp_to_unix(inode->i_last_access_time);
 489                 buf.modtime = wim_timestamp_to_unix(inode->i_last_write_time);
 490                 ret = utime(output_path, &buf);
 491         #endif
 492         }
 493         if (ret && args->num_utime_warnings < 10) {
 494                 WARNING_WITH_ERRNO("Failed to set timestamp on file `%s'",
 495                                     output_path);
 496                 args->num_utime_warnings++;
 497         }
 498         return 0;
 499 }
 500
 501 #endif /* !__WIN32__ */