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

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