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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                 const struct wim_dentry *d;
  99
 100                 num_path_components = 0;
 101                 for (d = dentry; d != args->extract_root; d = d->parent)
 102                         num_path_components++;
 103                 wimlib_assert(num_path_components > 0);
 104                 num_path_components--;
 105                 num_output_dir_path_components = get_num_path_components(args->target);
 106
 107                 if (args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
 108                         num_path_components++;
 109                         num_output_dir_path_components--;
 110                 }
 111                 extracted_file_len = strlen(lte->extracted_file);
 112
 113                 char buf[extracted_file_len + 3 * num_path_components + 1];
 114                 p = &buf[0];
 115
 116                 for (i = 0; i < num_path_components; i++) {
 117                         *p++ = '.';
 118                         *p++ = '.';
 119                         *p++ = '/';
 120                 }
 121                 p2 = lte->extracted_file;
 122                 while (*p2 == '/')
 123                         p2++;
 124                 while (num_output_dir_path_components > 0) {
 125                         p2 = path_next_part(p2);
 126                         num_output_dir_path_components--;
 127                 }
 128                 strcpy(p, p2);
 129                 if (symlink(buf, output_path) != 0) {
 130                         ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 131                                          buf, lte->extracted_file);
 132                         return WIMLIB_ERR_LINK;
 133                 }
 134         }
 135         return 0;
 136 }
 137
 138 static int
 139 symlink_apply_unix_data(const char *link,
 140                         const struct wimlib_unix_data *unix_data)
 141 {
 142         if (lchown(link, unix_data->uid, unix_data->gid)) {
 143                 if (errno == EPERM) {
 144                         /* Ignore */
 145                         WARNING_WITH_ERRNO("failed to set symlink UNIX "
 146                                            "owner/group on \"%s\"", link);
 147                 } else {
 148                         ERROR_WITH_ERRNO("failed to set symlink UNIX "
 149                                          "owner/group on \"%s\"", link);
 150                         return WIMLIB_ERR_INVALID_DENTRY;
 151                 }
 152         }
 153         return 0;
 154 }
 155
 156 static int
 157 fd_apply_unix_data(int fd, const char *path,
 158                    const struct wimlib_unix_data *unix_data,
 159                    int extract_flags)
 160 {
 161         if (extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS)
 162                 return 0;
 163
 164         if (fchown(fd, unix_data->uid, unix_data->gid)) {
 165                 if (errno == EPERM &&
 166                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 167                 {
 168                         WARNING_WITH_ERRNO("failed to set file UNIX "
 169                                            "owner/group on \"%s\"", path);
 170                 } else {
 171                         ERROR_WITH_ERRNO("failed to set file UNIX "
 172                                          "owner/group on \"%s\"", path);
 173                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 174                                 WIMLIB_ERR_WRITE;
 175                 }
 176         }
 177
 178         if (fchmod(fd, unix_data->mode)) {
 179                 if (errno == EPERM &&
 180                     !(extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
 181                 {
 182                         WARNING_WITH_ERRNO("failed to set UNIX file mode "
 183                                            "on \"%s\"", path);
 184                 } else {
 185                         ERROR_WITH_ERRNO("failed to set UNIX file mode "
 186                                          "on \"%s\"", path);
 187                         return (errno == EPERM) ? WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT :
 188                                 WIMLIB_ERR_WRITE;
 189                 }
 190         }
 191         return 0;
 192 }
 193
 194 static int
 195 dir_apply_unix_data(const char *dir, const struct wimlib_unix_data *unix_data,
 196                     int extract_flags)
 197 {
 198         int dfd = open(dir, O_RDONLY);
 199         int ret;
 200         if (dfd >= 0) {
 201                 ret = fd_apply_unix_data(dfd, dir, unix_data, extract_flags);
 202                 if (close(dfd) && ret == 0) {
 203                         ERROR_WITH_ERRNO("can't close directory `%s'", dir);
 204                         ret = WIMLIB_ERR_WRITE;
 205                 }
 206         } else {
 207                 ERROR_WITH_ERRNO("can't open directory `%s'", dir);
 208                 ret = WIMLIB_ERR_OPENDIR;
 209         }
 210         return ret;
 211 }
 212
 213 static int
 214 unix_extract_regular_file_unlinked(struct wim_dentry *dentry,
 215                                    struct apply_args *args,
 216                                    const char *output_path,
 217                                    struct wim_lookup_table_entry *lte)
 218 {
 219         /* Normal mode of extraction.  Regular files and hard links are
 220          * extracted in the way that they appear in the WIM. */
 221
 222         int out_fd;
 223         int ret;
 224         struct wim_inode *inode = dentry->d_inode;
 225
 226         if (!((args->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE)
 227                 && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 228                                      WIMLIB_EXTRACT_FLAG_HARDLINK))))
 229         {
 230                 /* If the dentry is part of a hard link set of at least 2
 231                  * dentries and one of the other dentries has already been
 232                  * extracted, make a hard link to the file corresponding to this
 233                  * already-extracted directory.  Otherwise, extract the file and
 234                  * set the inode->i_extracted_file field so that other dentries
 235                  * in the hard link group can link to it. */
 236                 if (inode->i_nlink > 1) {
 237                         if (inode->i_extracted_file) {
 238                                 DEBUG("Extracting hard link `%s' => `%s'",
 239                                       output_path, inode->i_extracted_file);
 240                                 if (link(inode->i_extracted_file, output_path) != 0) {
 241                                         ERROR_WITH_ERRNO("Failed to hard link "
 242                                                          "`%s' to `%s'",
 243                                                          output_path,
 244                                                          inode->i_extracted_file);
 245                                         return WIMLIB_ERR_LINK;
 246                                 }
 247                                 return 0;
 248                         }
 249                         FREE(inode->i_extracted_file);
 250                         inode->i_extracted_file = STRDUP(output_path);
 251                         if (!inode->i_extracted_file) {
 252                                 ERROR("Failed to allocate memory for filename");
 253                                 return WIMLIB_ERR_NOMEM;
 254                         }
 255                 }
 256         }
 257
 258         /* Extract the contents of the file to @output_path. */
 259
 260         out_fd = open(output_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 261         if (out_fd == -1) {
 262                 ERROR_WITH_ERRNO("Failed to open the file `%s' for writing",
 263                                  output_path);
 264                 return WIMLIB_ERR_OPEN;
 265         }
 266
 267         if (!lte) {
 268                 /* Empty file with no lookup table entry */
 269                 DEBUG("Empty file `%s'.", output_path);
 270                 ret = 0;
 271                 goto out_extract_unix_data;
 272         }
 273
 274         ret = extract_wim_resource_to_fd(lte, out_fd, wim_resource_size(lte));
 275         if (ret) {
 276                 ERROR("Failed to extract resource to `%s'", output_path);
 277                 goto out;
 278         }
 279
 280 out_extract_unix_data:
 281         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 282                 struct wimlib_unix_data unix_data;
 283                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 284                 if (ret > 0)
 285                         ;
 286                 else if (ret < 0)
 287                         ret = 0;
 288                 else
 289                         ret = fd_apply_unix_data(out_fd, output_path, &unix_data,
 290                                                  args->extract_flags);
 291                 if (ret)
 292                         goto out;
 293         }
 294         if (lte)
 295                 args->progress.extract.completed_bytes += wim_resource_size(lte);
 296 out:
 297         if (close(out_fd) != 0) {
 298                 ERROR_WITH_ERRNO("Failed to close file `%s'", output_path);
 299                 if (ret == 0)
 300                         ret = WIMLIB_ERR_WRITE;
 301         }
 302         return ret;
 303 }
 304
 305 static int
 306 unix_extract_regular_file(struct wim_dentry *dentry,
 307                           struct apply_args *args,
 308                           const char *output_path)
 309 {
 310         struct wim_lookup_table_entry *lte;
 311         const struct wim_inode *inode = dentry->d_inode;
 312
 313         lte = inode_unnamed_lte_resolved(inode);
 314
 315         if (lte && (args->extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
 316                                            WIMLIB_EXTRACT_FLAG_HARDLINK)))
 317         {
 318                 if (lte->extracted_file) {
 319                         return unix_extract_regular_file_linked(dentry,
 320                                                                 output_path,
 321                                                                 args, lte);
 322                 } else {
 323                         lte->extracted_file = STRDUP(output_path);
 324                         if (!lte->extracted_file)
 325                                 return WIMLIB_ERR_NOMEM;
 326                 }
 327         }
 328         return unix_extract_regular_file_unlinked(dentry, args, output_path, lte);
 329 }
 330
 331 static int
 332 unix_extract_symlink(struct wim_dentry *dentry,
 333                      struct apply_args *args,
 334                      const char *output_path)
 335 {
 336         char target[4096 + args->target_realpath_len];
 337         char *fixed_target;
 338         const struct wim_inode *inode = dentry->d_inode;
 339
 340         ssize_t ret = wim_inode_readlink(inode,
 341                                          target + args->target_realpath_len,
 342                                          sizeof(target) - args->target_realpath_len - 1);
 343         struct wim_lookup_table_entry *lte;
 344
 345         if (ret <= 0) {
 346                 ERROR("Could not read the symbolic link from dentry `%s'",
 347                       dentry_full_path(dentry));
 348                 return WIMLIB_ERR_INVALID_DENTRY;
 349         }
 350         target[args->target_realpath_len + ret] = '\0';
 351         if (target[args->target_realpath_len] == '/' &&
 352             args->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)
 353         {
 354                 /* Fix absolute symbolic link target to point into the actual
 355                  * extraction destination */
 356                 memcpy(target, args->target_realpath,
 357                        args->target_realpath_len);
 358                 fixed_target = target;
 359         } else {
 360                 /* Keep same link target */
 361                 fixed_target = target + args->target_realpath_len;
 362         }
 363         ret = symlink(fixed_target, output_path);
 364         if (ret) {
 365                 ERROR_WITH_ERRNO("Failed to symlink `%s' to `%s'",
 366                                  output_path, fixed_target);
 367                 return WIMLIB_ERR_LINK;
 368         }
 369         if (args->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 370                 struct wimlib_unix_data unix_data;
 371                 ret = inode_get_unix_data(inode, &unix_data, NULL);
 372                 if (ret > 0)
 373                         ;
 374                 else if (ret < 0)
 375                         ret = 0;
 376                 else
 377                         ret = symlink_apply_unix_data(output_path, &unix_data);
 378                 if (ret)
 379                         return ret;
 380         }
 381         lte = inode_unnamed_lte_resolved(inode);
 382         wimlib_assert(lte != NULL);
 383         args->progress.extract.completed_bytes += wim_resource_size(lte);
 384         return 0;
 385 }
 386
 387 static int
 388 unix_extract_directory(struct wim_dentry *dentry, const char *output_path,
 389                        int extract_flags)
 390 {
 391         int ret;
 392         struct stat stbuf;
 393
 394         ret = stat(output_path, &stbuf);
 395         if (ret == 0) {
 396                 if (S_ISDIR(stbuf.st_mode)) {
 397                         goto dir_exists;
 398                 } else {
 399                         ERROR("\"%s\" is not a directory", output_path);
 400                         return WIMLIB_ERR_MKDIR;
 401                 }
 402         } else {
 403                 if (errno != ENOENT) {
 404                         ERROR_WITH_ERRNO("Failed to stat \"%s\"", output_path);
 405                         return WIMLIB_ERR_STAT;
 406                 }
 407         }
 408
 409         if (mkdir(output_path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH)) {
 410                 ERROR_WITH_ERRNO("Cannot create directory \"%s\"", output_path);
 411                 return WIMLIB_ERR_MKDIR;
 412         }
 413 dir_exists:
 414         ret = 0;
 415         if (extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
 416                 struct wimlib_unix_data unix_data;
 417                 ret = inode_get_unix_data(dentry->d_inode, &unix_data, NULL);
 418                 if (ret > 0)
 419                         ;
 420                 else if (ret < 0)
 421                         ret = 0;
 422                 else
 423                         ret = dir_apply_unix_data(output_path, &unix_data,
 424                                                   extract_flags);
 425         }
 426         return ret;
 427 }
 428
 429 int
 430 unix_do_apply_dentry(const char *output_path, size_t output_path_len,
 431                      struct wim_dentry *dentry, struct apply_args *args)
 432 {
 433         const struct wim_inode *inode = dentry->d_inode;
 434
 435         if (inode_is_symlink(inode))
 436                 return unix_extract_symlink(dentry, args, output_path);
 437         else if (inode_is_directory(inode))
 438                 return unix_extract_directory(dentry, output_path, args->extract_flags);
 439         else
 440                 return unix_extract_regular_file(dentry, args, output_path);
 441 }
 442
 443 int
 444 unix_do_apply_dentry_timestamps(const char *output_path,
 445                                 size_t output_path_len,
 446                                 struct wim_dentry *dentry,
 447                                 struct apply_args *args)
 448 {
 449         int ret;
 450         const struct wim_inode *inode = dentry->d_inode;
 451
 452 #ifdef HAVE_UTIMENSAT
 453         /* Convert the WIM timestamps, which are accurate to 100 nanoseconds,
 454          * into `struct timespec's for passing to utimensat(), which is accurate
 455          * to 1 nanosecond. */
 456
 457         struct timespec ts[2];
 458         ts[0] = wim_timestamp_to_timespec(inode->i_last_access_time);
 459         ts[1] = wim_timestamp_to_timespec(inode->i_last_write_time);
 460         ret = utimensat(AT_FDCWD, output_path, ts, AT_SYMLINK_NOFOLLOW);
 461         if (ret)
 462                 ret = errno;
 463 #else
 464         ret = ENOSYS;
 465 #endif
 466
 467         if (ret == ENOSYS) {
 468                 /* utimensat() not implemented or not available */
 469         #ifdef HAVE_LUTIMES
 470                 /* Convert the WIM timestamps, which are accurate to 100
 471                  * nanoseconds, into `struct timeval's for passing to lutimes(),
 472                  * which is accurate to 1 microsecond. */
 473                 struct timeval tv[2];
 474                 tv[0] = wim_timestamp_to_timeval(inode->i_last_access_time);
 475                 tv[1] = wim_timestamp_to_timeval(inode->i_last_write_time);
 476                 ret = lutimes(output_path, tv);
 477                 if (ret)
 478                         ret = errno;
 479         #endif
 480         }
 481
 482         if (ret == ENOSYS) {
 483                 /* utimensat() and lutimes() both not implemented or not
 484                  * available */
 485         #ifdef HAVE_UTIME
 486                 /* Convert the WIM timestamps, which are accurate to 100
 487                  * nanoseconds, into a `struct utimbuf's for passing to
 488                  * utime(), which is accurate to 1 second. */
 489                 struct utimbuf buf;
 490                 buf.actime = wim_timestamp_to_unix(inode->i_last_access_time);
 491                 buf.modtime = wim_timestamp_to_unix(inode->i_last_write_time);
 492                 ret = utime(output_path, &buf);
 493         #endif
 494         }
 495         if (ret && args->num_utime_warnings < 10) {
 496                 WARNING_WITH_ERRNO("Failed to set timestamp on file `%s'",
 497                                     output_path);
 498                 args->num_utime_warnings++;
 499         }
 500         return 0;
 501 }
 502
 503 #endif /* !__WIN32__ */