1 /* Extract files from a tar archive.
3 Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000,
4 2001, 2003, 2004, 2005, 2006, 2007, 2010 Free Software Foundation, Inc.
6 Written by John Gilmore, on 1985-11-19.
8 This program is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 3, or (at your option) any later
13 This program is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
16 Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
30 static bool we_are_root; /* true if our effective uid == 0 */
31 static mode_t newdir_umask; /* umask when creating new directories */
32 static mode_t current_umask; /* current umask (which is set to 0 if -p) */
34 #define ALL_MODE_BITS ((mode_t) ~ (mode_t) 0)
36 #if ! HAVE_FCHMOD && ! defined fchmod
37 # define fchmod(fd, mode) (errno = ENOSYS, -1)
39 #if ! HAVE_FCHOWN && ! defined fchown
40 # define fchown(fd, uid, gid) (errno = ENOSYS, -1)
43 /* Return true if an error number ERR means the system call is
44 supported in this case. */
48 return ! (err == ENOSYS
50 || (EOPNOTSUPP != ENOTSUP && err == EOPNOTSUPP));
53 /* List of directories whose statuses we need to extract after we've
54 finished extracting their subsidiary files. If you consider each
55 contiguous subsequence of elements of the form [D]?[^D]*, where [D]
56 represents an element where AFTER_LINKS is nonzero and [^D]
57 represents an element where AFTER_LINKS is zero, then the head
58 of the subsequence has the longest name, and each non-head element
59 in the prefix is an ancestor (in the directory hierarchy) of the
62 struct delayed_set_stat
64 /* Next directory in list. */
65 struct delayed_set_stat *next;
67 /* Metadata for this directory. */
70 mode_t mode; /* The desired mode is MODE & ~ current_umask. */
73 struct timespec atime;
74 struct timespec mtime;
76 /* An estimate of the directory's current mode, along with a mask
77 specifying which bits of this estimate are known to be correct.
78 If CURRENT_MODE_MASK is zero, CURRENT_MODE's value doesn't
81 mode_t current_mode_mask;
83 /* This directory is an intermediate directory that was created
84 as an ancestor of some other directory; it was not mentioned
85 in the archive, so do not set its uid, gid, atime, or mtime,
86 and don't alter its mode outside of MODE_RWX. */
89 /* Whether symbolic links should be followed when accessing the
93 /* Do not set the status of this directory until after delayed
97 /* Directory that the name is relative to. */
100 /* Length and contents of name. */
101 size_t file_name_len;
105 static struct delayed_set_stat *delayed_set_stat_head;
107 /* List of links whose creation we have delayed. */
110 /* The next delayed link in the list. */
111 struct delayed_link *next;
113 /* The device, inode number and ctime of the placeholder. Use
114 ctime, not mtime, to make false matches less likely if some
115 other process removes the placeholder. */
118 struct timespec ctime;
120 /* True if the link is symbolic. */
123 /* The desired metadata, valid only the link is symbolic. */
127 struct timespec atime;
128 struct timespec mtime;
130 /* The directory that the sources and target are relative to. */
133 /* A list of sources for this link. The sources are all to be
134 hard-linked together. */
135 struct string_list *sources;
137 /* The desired target of the desired link. */
141 static struct delayed_link *delayed_link_head;
145 struct string_list *next;
149 /* Set up to extract files. */
153 we_are_root = geteuid () == 0;
154 same_permissions_option += we_are_root;
155 same_owner_option += we_are_root;
157 /* Option -p clears the kernel umask, so it does not affect proper
158 restoration of file permissions. New intermediate directories will
159 comply with umask at start of program. */
161 newdir_umask = umask (0);
162 if (0 < same_permissions_option)
166 umask (newdir_umask); /* restore the kernel umask */
167 current_umask = newdir_umask;
171 /* Use fchmod if possible, fchmodat otherwise. */
173 fd_chmod (int fd, char const *file, mode_t mode, int atflag)
177 int result = fchmod (fd, mode);
178 if (result == 0 || implemented (errno))
181 return fchmodat (chdir_fd, file, mode, atflag);
184 /* Use fchown if possible, fchownat otherwise. */
186 fd_chown (int fd, char const *file, uid_t uid, gid_t gid, int atflag)
190 int result = fchown (fd, uid, gid);
191 if (result == 0 || implemented (errno))
194 return fchownat (chdir_fd, file, uid, gid, atflag);
197 /* Use fstat if possible, fstatat otherwise. */
199 fd_stat (int fd, char const *file, struct stat *st, int atflag)
203 : fstatat (chdir_fd, file, st, atflag));
206 /* Set the mode for FILE_NAME to MODE.
207 MODE_MASK specifies the bits of MODE that we care about;
208 thus if MODE_MASK is zero, do nothing.
209 If FD is nonnegative, it is a file descriptor for the file.
210 CURRENT_MODE and CURRENT_MODE_MASK specify information known about
211 the file's current mode, using the style of struct delayed_set_stat.
212 TYPEFLAG specifies the type of the file.
213 ATFLAG specifies the flag to use when statting the file. */
215 set_mode (char const *file_name,
216 mode_t mode, mode_t mode_mask, int fd,
217 mode_t current_mode, mode_t current_mode_mask,
218 char typeflag, int atflag)
220 if (((current_mode ^ mode) | ~ current_mode_mask) & mode_mask)
222 if (MODE_ALL & ~ mode_mask & ~ current_mode_mask)
225 if (fd_stat (fd, file_name, &st, atflag) != 0)
227 stat_error (file_name);
230 current_mode = st.st_mode;
233 current_mode &= MODE_ALL;
234 mode = (current_mode & ~ mode_mask) | (mode & mode_mask);
236 if (current_mode != mode)
239 fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
241 /* On Solaris, chmod may fail if we don't have PRIV_ALL, because
242 setuid-root files would otherwise be a backdoor. See
243 http://opensolaris.org/jive/thread.jspa?threadID=95826
245 if (chmod_errno == EPERM && (mode & S_ISUID)
246 && priv_set_restore_linkdir () == 0)
249 fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
250 priv_set_remove_linkdir ();
253 /* Linux fchmodat does not support AT_SYMLINK_NOFOLLOW, and
254 returns ENOTSUP even when operating on non-symlinks, try
255 again with the flag disabled if it does not appear to be
256 supported and if the file is not a symlink. This
257 introduces a race, alas. */
258 if (atflag && typeflag != SYMTYPE && ! implemented (chmod_errno))
259 chmod_errno = fd_chmod (fd, file_name, mode, 0) == 0 ? 0 : errno;
262 && (typeflag != SYMTYPE || implemented (chmod_errno)))
265 chmod_error_details (file_name, mode);
271 /* Check time after successfully setting FILE_NAME's time stamp to T. */
273 check_time (char const *file_name, struct timespec t)
276 WARNOPT (WARN_TIMESTAMP,
277 (0, 0, _("%s: implausibly old time stamp %s"),
278 file_name, tartime (t, true)));
279 else if (timespec_cmp (volume_start_time, t) < 0)
283 if (timespec_cmp (now, t) < 0)
285 char buf[TIMESPEC_STRSIZE_BOUND];
286 struct timespec diff;
287 diff.tv_sec = t.tv_sec - now.tv_sec;
288 diff.tv_nsec = t.tv_nsec - now.tv_nsec;
289 if (diff.tv_nsec < 0)
291 diff.tv_nsec += BILLION;
294 WARNOPT (WARN_TIMESTAMP,
295 (0, 0, _("%s: time stamp %s is %s s in the future"),
296 file_name, tartime (t, true), code_timespec (diff, buf)));
301 /* Restore stat attributes (owner, group, mode and times) for
302 FILE_NAME, using information given in *ST.
303 If FD is nonnegative, it is a file descriptor for the file.
304 CURRENT_MODE and CURRENT_MODE_MASK specify information known about
305 the file's current mode, using the style of struct delayed_set_stat.
306 TYPEFLAG specifies the type of the file.
307 If INTERDIR, this is an intermediate directory.
308 ATFLAG specifies the flag to use when statting the file. */
311 set_stat (char const *file_name,
312 struct tar_stat_info const *st,
313 int fd, mode_t current_mode, mode_t current_mode_mask,
314 char typeflag, bool interdir, int atflag)
316 /* Do the utime before the chmod because some versions of utime are
317 broken and trash the modes of the file. */
319 if (! touch_option && ! interdir)
321 struct timespec ts[2];
322 if (incremental_option)
325 ts[0].tv_nsec = UTIME_OMIT;
328 if (fdutimensat (fd, chdir_fd, file_name, ts, atflag) == 0)
330 if (incremental_option)
331 check_time (file_name, ts[0]);
332 check_time (file_name, ts[1]);
334 else if (typeflag != SYMTYPE || implemented (errno))
335 utime_error (file_name);
338 if (0 < same_owner_option && ! interdir)
340 /* Some systems allow non-root users to give files away. Once this
341 done, it is not possible anymore to change file permissions.
342 However, setting file permissions now would be incorrect, since
343 they would apply to the wrong user, and there would be a race
344 condition. So, don't use systems that allow non-root users to
346 uid_t uid = st->stat.st_uid;
347 gid_t gid = st->stat.st_gid;
349 if (fd_chown (fd, file_name, uid, gid, atflag) == 0)
351 /* Changing the owner can clear st_mode bits in some cases. */
352 if ((current_mode | ~ current_mode_mask) & S_IXUGO)
353 current_mode_mask &= ~ (current_mode & (S_ISUID | S_ISGID));
355 else if (typeflag != SYMTYPE || implemented (errno))
356 chown_error_details (file_name, uid, gid);
360 st->stat.st_mode & ~ current_umask,
361 0 < same_permissions_option && ! interdir ? MODE_ALL : MODE_RWX,
362 fd, current_mode, current_mode_mask, typeflag, atflag);
365 /* For each entry H in the leading prefix of entries in HEAD that do
366 not have after_links marked, mark H and fill in its dev and ino
367 members. Assume HEAD && ! HEAD->after_links. */
369 mark_after_links (struct delayed_set_stat *head)
371 struct delayed_set_stat *h = head;
378 if (deref_stat (h->file_name, &st) != 0)
379 stat_error (h->file_name);
386 while ((h = h->next) && ! h->after_links);
389 /* Remember to restore stat attributes (owner, group, mode and times)
390 for the directory FILE_NAME, using information given in *ST,
391 once we stop extracting files into that directory.
393 If ST is null, merely create a placeholder node for an intermediate
394 directory that was created by make_directories.
396 NOTICE: this works only if the archive has usual member order, i.e.
397 directory, then the files in that directory. Incremental archive have
398 somewhat reversed order: first go subdirectories, then all other
399 members. To help cope with this case the variable
400 delay_directory_restore_option is set by prepare_to_extract.
402 If an archive was explicitely created so that its member order is
403 reversed, some directory timestamps can be restored incorrectly,
405 tar --no-recursion -cf archive dir dir/file1 foo dir/file2
408 delay_set_stat (char const *file_name, struct tar_stat_info const *st,
409 mode_t current_mode, mode_t current_mode_mask,
410 mode_t mode, int atflag)
412 size_t file_name_len = strlen (file_name);
413 struct delayed_set_stat *data =
414 xmalloc (offsetof (struct delayed_set_stat, file_name)
415 + file_name_len + 1);
416 data->next = delayed_set_stat_head;
420 data->dev = st->stat.st_dev;
421 data->ino = st->stat.st_ino;
422 data->uid = st->stat.st_uid;
423 data->gid = st->stat.st_gid;
424 data->atime = st->atime;
425 data->mtime = st->mtime;
427 data->file_name_len = file_name_len;
428 data->current_mode = current_mode;
429 data->current_mode_mask = current_mode_mask;
430 data->interdir = ! st;
431 data->atflag = atflag;
432 data->after_links = 0;
433 data->change_dir = chdir_current;
434 strcpy (data->file_name, file_name);
435 delayed_set_stat_head = data;
436 if (must_be_dot_or_slash (file_name))
437 mark_after_links (data);
440 /* Update the delayed_set_stat info for an intermediate directory
441 created within the file name of DIR. The intermediate directory turned
442 out to be the same as this directory, e.g. due to ".." or symbolic
443 links. *DIR_STAT_INFO is the status of the directory. */
445 repair_delayed_set_stat (char const *dir,
446 struct stat const *dir_stat_info)
448 struct delayed_set_stat *data;
449 for (data = delayed_set_stat_head; data; data = data->next)
452 if (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 0)
454 stat_error (data->file_name);
458 if (st.st_dev == dir_stat_info->st_dev
459 && st.st_ino == dir_stat_info->st_ino)
461 data->dev = current_stat_info.stat.st_dev;
462 data->ino = current_stat_info.stat.st_ino;
463 data->mode = current_stat_info.stat.st_mode;
464 data->uid = current_stat_info.stat.st_uid;
465 data->gid = current_stat_info.stat.st_gid;
466 data->atime = current_stat_info.atime;
467 data->mtime = current_stat_info.mtime;
468 data->current_mode = st.st_mode;
469 data->current_mode_mask = ALL_MODE_BITS;
470 data->interdir = false;
475 ERROR ((0, 0, _("%s: Unexpected inconsistency when making directory"),
476 quotearg_colon (dir)));
479 /* After a file/link/directory creation has failed, see if
480 it's because some required directory was not present, and if so,
481 create all required directories. Return zero if all the required
482 directories were created, nonzero (issuing a diagnostic) otherwise.
483 Set *INTERDIR_MADE if at least one directory was created. */
485 make_directories (char *file_name, bool *interdir_made)
487 char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
488 char *cursor; /* points into the file name */
490 for (cursor = cursor0; *cursor; cursor++)
496 if (! ISSLASH (*cursor))
499 /* Avoid mkdir of empty string, if leading or double '/'. */
501 if (cursor == cursor0 || ISSLASH (cursor[-1]))
504 /* Avoid mkdir where last part of file name is "." or "..". */
506 if (cursor[-1] == '.'
507 && (cursor == cursor0 + 1 || ISSLASH (cursor[-2])
508 || (cursor[-2] == '.'
509 && (cursor == cursor0 + 2 || ISSLASH (cursor[-3])))))
512 *cursor = '\0'; /* truncate the name there */
513 desired_mode = MODE_RWX & ~ newdir_umask;
514 mode = desired_mode | (we_are_root ? 0 : MODE_WXUSR);
515 status = mkdirat (chdir_fd, file_name, mode);
519 /* Create a struct delayed_set_stat even if
520 mode == desired_mode, because
521 repair_delayed_set_stat may need to update the struct. */
522 delay_set_stat (file_name,
523 0, mode & ~ current_umask, MODE_RWX,
524 desired_mode, AT_SYMLINK_NOFOLLOW);
526 print_for_mkdir (file_name, cursor - file_name, desired_mode);
527 *interdir_made = true;
529 else if (errno == EEXIST)
533 /* Check whether the desired file exists. Even when the
534 file exists, mkdir can fail with some errno value E other
535 than EEXIST, so long as E describes an error condition
536 that also applies. */
539 status = fstatat (chdir_fd, file_name, &st, 0);
543 mkdir_error (file_name);
555 /* Return true if FILE_NAME (with status *STP, if STP) is not a
556 directory, and has a time stamp newer than (or equal to) that of
559 file_newer_p (const char *file_name, struct stat const *stp,
560 struct tar_stat_info *tar_stat)
566 if (deref_stat (file_name, &st) != 0)
570 stat_warn (file_name);
571 /* Be safer: if the file exists, assume it is newer. */
579 return (! S_ISDIR (stp->st_mode)
580 && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (stp)) <= 0);
585 #define RECOVER_SKIP 2
587 /* Attempt repairing what went wrong with the extraction. Delete an
588 already existing file or create missing intermediate directories.
589 Return RECOVER_OK if we somewhat increased our chances at a successful
590 extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the
591 caller should skip extraction of that member. The value of errno is
592 properly restored on returning RECOVER_NO.
594 If REGULAR, the caller was trying to extract onto a regular file.
596 Set *INTERDIR_MADE if an intermediate directory is made as part of
597 the recovery process. */
600 maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
604 struct stat const *stp = 0;
613 /* With open ("symlink", O_NOFOLLOW|...), POSIX says errno == ELOOP,
614 but some operating systems do not conform to the standard. */
616 /* NetBSD uses errno == EFTYPE; see <http://gnats.netbsd.org/43154>. */
619 /* FreeBSD 8.1 uses errno == EMLINK. */
621 /* Tru64 5.1B uses errno == ENOTSUP. */
625 || old_files_option != OVERWRITE_OLD_FILES || dereference_option)
627 if (strchr (file_name, '/'))
629 if (deref_stat (file_name, &st) != 0)
634 /* The caller tried to open a symbolic link with O_NOFOLLOW.
635 Fall through, treating it as an already-existing file. */
638 /* Remove an old file, if the options allow this. */
640 switch (old_files_option)
645 case KEEP_NEWER_FILES:
646 if (file_newer_p (file_name, stp, ¤t_stat_info))
650 case DEFAULT_OLD_FILES:
651 case NO_OVERWRITE_DIR_OLD_FILES:
652 case OVERWRITE_OLD_FILES:
653 if (0 < remove_any_file (file_name, ORDINARY_REMOVE_OPTION))
657 case UNLINK_FIRST_OLD_FILES:
662 /* Attempt creating missing intermediate directories. */
663 if (make_directories (file_name, interdir_made) == 0 && *interdir_made)
668 /* Just say we can't do anything about it... */
676 /* Fix the statuses of all directories whose statuses need fixing, and
677 which are not ancestors of FILE_NAME. If AFTER_LINKS is
678 nonzero, do this for all such directories; otherwise, stop at the
679 first directory that is marked to be fixed up only after delayed
680 links are applied. */
682 apply_nonancestor_delayed_set_stat (char const *file_name, bool after_links)
684 size_t file_name_len = strlen (file_name);
685 bool check_for_renamed_directories = 0;
687 while (delayed_set_stat_head)
689 struct delayed_set_stat *data = delayed_set_stat_head;
690 bool skip_this_one = 0;
692 mode_t current_mode = data->current_mode;
693 mode_t current_mode_mask = data->current_mode_mask;
695 check_for_renamed_directories |= data->after_links;
697 if (after_links < data->after_links
698 || (data->file_name_len < file_name_len
699 && file_name[data->file_name_len]
700 && (ISSLASH (file_name[data->file_name_len])
701 || ISSLASH (file_name[data->file_name_len - 1]))
702 && memcmp (file_name, data->file_name, data->file_name_len) == 0))
705 chdir_do (data->change_dir);
707 if (check_for_renamed_directories)
709 if (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 0)
711 stat_error (data->file_name);
716 current_mode = st.st_mode;
717 current_mode_mask = ALL_MODE_BITS;
718 if (! (st.st_dev == data->dev && st.st_ino == data->ino))
721 _("%s: Directory renamed before its status could be extracted"),
722 quotearg_colon (data->file_name)));
730 struct tar_stat_info sb;
731 sb.stat.st_mode = data->mode;
732 sb.stat.st_uid = data->uid;
733 sb.stat.st_gid = data->gid;
734 sb.atime = data->atime;
735 sb.mtime = data->mtime;
736 set_stat (data->file_name, &sb,
737 -1, current_mode, current_mode_mask,
738 DIRTYPE, data->interdir, data->atflag);
741 delayed_set_stat_head = data->next;
748 /* Extractor functions for various member types */
751 extract_dir (char *file_name, int typeflag)
755 mode_t current_mode = 0;
756 mode_t current_mode_mask = 0;
758 bool interdir_made = false;
760 /* Save 'root device' to avoid purging mount points. */
761 if (one_file_system_option && root_device == 0)
765 if (fstatat (chdir_fd, ".", &st, 0) != 0)
768 root_device = st.st_dev;
771 if (incremental_option)
772 /* Read the entry and delete files that aren't listed in the archive. */
773 purge_directory (file_name);
774 else if (typeflag == GNUTYPE_DUMPDIR)
777 /* If ownership or permissions will be restored later, create the
778 directory with restrictive permissions at first, so that in the
779 meantime processes owned by other users do not inadvertently
780 create files under this directory that inherit the wrong owner,
781 group, or permissions from the directory. If not root, though,
782 make the directory writeable and searchable at first, so that
783 files can be created under it. */
784 mode = ((current_stat_info.stat.st_mode
785 & (0 < same_owner_option || 0 < same_permissions_option
788 | (we_are_root ? 0 : MODE_WXUSR));
792 status = mkdirat (chdir_fd, file_name, mode);
795 current_mode = mode & ~ current_umask;
796 current_mode_mask = MODE_RWX;
797 atflag = AT_SYMLINK_NOFOLLOW;
803 || old_files_option == DEFAULT_OLD_FILES
804 || old_files_option == OVERWRITE_OLD_FILES))
807 if (deref_stat (file_name, &st) == 0)
809 current_mode = st.st_mode;
810 current_mode_mask = ALL_MODE_BITS;
812 if (S_ISDIR (current_mode))
816 repair_delayed_set_stat (file_name, &st);
825 switch (maybe_recoverable (file_name, false, &interdir_made))
836 mkdir_error (file_name);
845 || old_files_option == DEFAULT_OLD_FILES
846 || old_files_option == OVERWRITE_OLD_FILES)
847 delay_set_stat (file_name, ¤t_stat_info,
848 current_mode, current_mode_mask,
849 current_stat_info.stat.st_mode, atflag);
856 open_output_file (char const *file_name, int typeflag, mode_t mode,
857 mode_t *current_mode, mode_t *current_mode_mask)
860 bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES;
861 int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK
863 | (overwriting_old_files
864 ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW)
867 if (typeflag == CONTTYPE)
869 static int conttype_diagnosed;
871 if (!conttype_diagnosed)
873 conttype_diagnosed = 1;
874 WARNOPT (WARN_CONTIGUOUS_CAST,
875 (0, 0, _("Extracting contiguous files as regular files")));
879 /* If O_NOFOLLOW is needed but does not work, check for a symlink
880 separately. There's a race condition, but that cannot be avoided
881 on hosts lacking O_NOFOLLOW. */
882 if (! O_NOFOLLOW && overwriting_old_files && ! dereference_option)
885 if (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0
886 && S_ISLNK (st.st_mode))
893 fd = openat (chdir_fd, file_name, openflag, mode);
896 if (overwriting_old_files)
899 if (fstat (fd, &st) != 0)
906 if (! S_ISREG (st.st_mode))
912 *current_mode = st.st_mode;
913 *current_mode_mask = ALL_MODE_BITS;
917 *current_mode = mode & ~ current_umask;
918 *current_mode_mask = MODE_RWX;
926 extract_file (char *file_name, int typeflag)
930 union block *data_block;
934 bool interdir_made = false;
935 mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX
936 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
937 mode_t current_mode = 0;
938 mode_t current_mode_mask = 0;
940 if (to_stdout_option)
942 else if (to_command_option)
944 fd = sys_exec_command (file_name, 'f', ¤t_stat_info);
953 while ((fd = open_output_file (file_name, typeflag, mode,
954 ¤t_mode, ¤t_mode_mask))
957 int recover = maybe_recoverable (file_name, true, &interdir_made);
958 if (recover != RECOVER_OK)
961 if (recover == RECOVER_SKIP)
963 open_error (file_name);
969 mv_begin_read (¤t_stat_info);
970 if (current_stat_info.is_sparse)
971 sparse_extract_file (fd, ¤t_stat_info, &size);
973 for (size = current_stat_info.stat.st_size; size > 0; )
977 /* Locate data, determine max length writeable, write it,
978 block that we have used the data, then check if the write
981 data_block = find_next_block ();
984 ERROR ((0, 0, _("Unexpected EOF in archive")));
985 break; /* FIXME: What happens, then? */
988 written = available_space_after (data_block);
993 count = full_write (fd, data_block->buffer, written);
996 set_next_block_after ((union block *)
997 (data_block->buffer + written - 1));
998 if (count != written)
1000 if (!to_command_option)
1001 write_error_details (file_name, count, written);
1002 /* FIXME: shouldn't we restore from backup? */
1011 /* If writing to stdout, don't try to do anything to the filename;
1012 it doesn't exist, or we don't want to touch it anyway. */
1014 if (to_stdout_option)
1017 if (! to_command_option)
1018 set_stat (file_name, ¤t_stat_info, fd,
1019 current_mode, current_mode_mask, typeflag, false,
1020 (old_files_option == OVERWRITE_OLD_FILES
1021 ? 0 : AT_SYMLINK_NOFOLLOW));
1023 status = close (fd);
1025 close_error (file_name);
1027 if (to_command_option)
1028 sys_wait_command ();
1033 /* Create a placeholder file with name FILE_NAME, which will be
1034 replaced after other extraction is done by a symbolic link if
1035 IS_SYMLINK is true, and by a hard link otherwise. Set
1036 *INTERDIR_MADE if an intermediate directory is made in the
1040 create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made)
1045 while ((fd = openat (chdir_fd, file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0)
1047 switch (maybe_recoverable (file_name, false, interdir_made))
1056 open_error (file_name);
1061 if (fstat (fd, &st) != 0)
1063 stat_error (file_name);
1066 else if (close (fd) != 0)
1067 close_error (file_name);
1070 struct delayed_set_stat *h;
1071 struct delayed_link *p =
1072 xmalloc (offsetof (struct delayed_link, target)
1073 + strlen (current_stat_info.link_name)
1075 p->next = delayed_link_head;
1076 delayed_link_head = p;
1079 p->ctime = get_stat_ctime (&st);
1080 p->is_symlink = is_symlink;
1083 p->mode = current_stat_info.stat.st_mode;
1084 p->uid = current_stat_info.stat.st_uid;
1085 p->gid = current_stat_info.stat.st_gid;
1086 p->atime = current_stat_info.atime;
1087 p->mtime = current_stat_info.mtime;
1089 p->change_dir = chdir_current;
1090 p->sources = xmalloc (offsetof (struct string_list, string)
1091 + strlen (file_name) + 1);
1092 p->sources->next = 0;
1093 strcpy (p->sources->string, file_name);
1094 strcpy (p->target, current_stat_info.link_name);
1096 h = delayed_set_stat_head;
1097 if (h && ! h->after_links
1098 && strncmp (file_name, h->file_name, h->file_name_len) == 0
1099 && ISSLASH (file_name[h->file_name_len])
1100 && (last_component (file_name) == file_name + h->file_name_len + 1))
1101 mark_after_links (h);
1110 extract_link (char *file_name, int typeflag)
1112 bool interdir_made = false;
1113 char const *link_name;
1116 link_name = current_stat_info.link_name;
1118 if (! absolute_names_option && contains_dot_dot (link_name))
1119 return create_placeholder_file (file_name, false, &interdir_made);
1123 struct stat st1, st2;
1125 int status = linkat (chdir_fd, link_name, chdir_fd, file_name, 0);
1130 struct delayed_link *ds = delayed_link_head;
1132 && fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW) == 0)
1133 for (; ds; ds = ds->next)
1134 if (ds->change_dir == chdir_current
1135 && ds->dev == st1.st_dev
1136 && ds->ino == st1.st_ino
1137 && timespec_cmp (ds->ctime, get_stat_ctime (&st1)) == 0)
1139 struct string_list *p = xmalloc (offsetof (struct string_list, string)
1140 + strlen (file_name) + 1);
1141 strcpy (p->string, file_name);
1142 p->next = ds->sources;
1148 else if ((e == EEXIST && strcmp (link_name, file_name) == 0)
1149 || ((fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW)
1151 && (fstatat (chdir_fd, file_name, &st2, AT_SYMLINK_NOFOLLOW)
1153 && st1.st_dev == st2.st_dev
1154 && st1.st_ino == st2.st_ino))
1159 while ((rc = maybe_recoverable (file_name, false, &interdir_made))
1162 if (rc == RECOVER_SKIP)
1164 if (!(incremental_option && errno == EEXIST))
1166 link_error (link_name, file_name);
1173 extract_symlink (char *file_name, int typeflag)
1176 bool interdir_made = false;
1178 if (! absolute_names_option
1179 && (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name)
1180 || contains_dot_dot (current_stat_info.link_name)))
1181 return create_placeholder_file (file_name, true, &interdir_made);
1183 while (symlinkat (current_stat_info.link_name, chdir_fd, file_name) != 0)
1184 switch (maybe_recoverable (file_name, false, &interdir_made))
1193 symlink_error (current_stat_info.link_name, file_name);
1197 set_stat (file_name, ¤t_stat_info, -1, 0, 0,
1198 SYMTYPE, false, AT_SYMLINK_NOFOLLOW);
1202 static int warned_once;
1207 WARNOPT (WARN_SYMBOLIC_CAST,
1209 _("Attempting extraction of symbolic links as hard links")));
1211 return extract_link (file_name, typeflag);
1215 #if S_IFCHR || S_IFBLK
1217 extract_node (char *file_name, int typeflag)
1219 bool interdir_made = false;
1220 mode_t mode = (current_stat_info.stat.st_mode & (MODE_RWX | S_IFBLK | S_IFCHR)
1221 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
1223 while (mknodat (chdir_fd, file_name, mode, current_stat_info.stat.st_rdev)
1225 switch (maybe_recoverable (file_name, false, &interdir_made))
1234 mknod_error (file_name);
1238 set_stat (file_name, ¤t_stat_info, -1,
1239 mode & ~ current_umask, MODE_RWX,
1240 typeflag, false, AT_SYMLINK_NOFOLLOW);
1245 #if HAVE_MKFIFO || defined mkfifo
1247 extract_fifo (char *file_name, int typeflag)
1249 bool interdir_made = false;
1250 mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX
1251 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
1253 while (mkfifoat (chdir_fd, file_name, mode) != 0)
1254 switch (maybe_recoverable (file_name, false, &interdir_made))
1263 mkfifo_error (file_name);
1267 set_stat (file_name, ¤t_stat_info, -1,
1268 mode & ~ current_umask, MODE_RWX,
1269 typeflag, false, AT_SYMLINK_NOFOLLOW);
1275 extract_volhdr (char *file_name, int typeflag)
1282 extract_failure (char *file_name, int typeflag)
1287 typedef int (*tar_extractor_t) (char *file_name, int typeflag);
1291 /* Prepare to extract a file. Find extractor function.
1292 Return zero if extraction should not proceed. */
1295 prepare_to_extract (char const *file_name, int typeflag, tar_extractor_t *fun)
1299 if (EXTRACT_OVER_PIPE)
1302 /* Select the extractor */
1305 case GNUTYPE_SPARSE:
1306 *fun = extract_file;
1313 /* Appears to be a file. But BSD tar uses the convention that a slash
1314 suffix means a directory. */
1315 if (current_stat_info.had_trailing_slash)
1319 *fun = extract_file;
1325 *fun = extract_symlink;
1329 *fun = extract_link;
1334 current_stat_info.stat.st_mode |= S_IFCHR;
1335 *fun = extract_node;
1341 current_stat_info.stat.st_mode |= S_IFBLK;
1342 *fun = extract_node;
1346 #if HAVE_MKFIFO || defined mkfifo
1348 *fun = extract_fifo;
1353 case GNUTYPE_DUMPDIR:
1355 if (current_stat_info.is_dumpdir)
1356 delay_directory_restore_option = true;
1359 case GNUTYPE_VOLHDR:
1360 *fun = extract_volhdr;
1363 case GNUTYPE_MULTIVOL:
1365 _("%s: Cannot extract -- file is continued from another volume"),
1366 quotearg_colon (current_stat_info.file_name)));
1367 *fun = extract_failure;
1370 case GNUTYPE_LONGNAME:
1371 case GNUTYPE_LONGLINK:
1372 ERROR ((0, 0, _("Unexpected long name header")));
1373 *fun = extract_failure;
1377 WARNOPT (WARN_UNKNOWN_CAST,
1379 _("%s: Unknown file type `%c', extracted as normal file"),
1380 quotearg_colon (file_name), typeflag));
1381 *fun = extract_file;
1384 /* Determine whether the extraction should proceed */
1388 switch (old_files_option)
1390 case UNLINK_FIRST_OLD_FILES:
1391 if (!remove_any_file (file_name,
1392 recursive_unlink_option ? RECURSIVE_REMOVE_OPTION
1393 : ORDINARY_REMOVE_OPTION)
1394 && errno && errno != ENOENT)
1396 unlink_error (file_name);
1401 case KEEP_NEWER_FILES:
1402 if (file_newer_p (file_name, 0, ¤t_stat_info))
1404 WARNOPT (WARN_IGNORE_NEWER,
1405 (0, 0, _("Current %s is newer or same age"),
1406 quote (file_name)));
1418 /* Extract a file from the archive. */
1420 extract_archive (void)
1423 tar_extractor_t fun;
1425 fatal_exit_hook = extract_finish;
1427 set_next_block_after (current_header);
1429 if (!current_stat_info.file_name[0]
1430 || (interactive_option
1431 && !confirm ("extract", current_stat_info.file_name)))
1437 /* Print the block from current_header and current_stat. */
1439 print_header (¤t_stat_info, current_header, -1);
1441 /* Restore stats for all non-ancestor directories, unless
1442 it is an incremental archive.
1443 (see NOTICE in the comment to delay_set_stat above) */
1444 if (!delay_directory_restore_option)
1446 int dir = chdir_current;
1447 apply_nonancestor_delayed_set_stat (current_stat_info.file_name, 0);
1451 /* Take a safety backup of a previously existing file. */
1454 if (!maybe_backup_file (current_stat_info.file_name, 0))
1457 ERROR ((0, e, _("%s: Was unable to backup this file"),
1458 quotearg_colon (current_stat_info.file_name)));
1463 /* Extract the archive entry according to its type. */
1465 typeflag = sparse_member_p (¤t_stat_info) ?
1466 GNUTYPE_SPARSE : current_header->header.typeflag;
1468 if (prepare_to_extract (current_stat_info.file_name, typeflag, &fun))
1470 if (fun && (*fun) (current_stat_info.file_name, typeflag)
1472 undo_last_backup ();
1479 /* Extract the links whose final extraction were delayed. */
1481 apply_delayed_links (void)
1483 struct delayed_link *ds;
1485 for (ds = delayed_link_head; ds; )
1487 struct string_list *sources = ds->sources;
1488 char const *valid_source = 0;
1490 chdir_do (ds->change_dir);
1492 for (sources = ds->sources; sources; sources = sources->next)
1494 char const *source = sources->string;
1497 /* Make sure the placeholder file is still there. If not,
1498 don't create a link, as the placeholder was probably
1499 removed by a later extraction. */
1500 if (fstatat (chdir_fd, source, &st, AT_SYMLINK_NOFOLLOW) == 0
1501 && st.st_dev == ds->dev
1502 && st.st_ino == ds->ino
1503 && timespec_cmp (get_stat_ctime (&st), ds->ctime) == 0)
1505 /* Unlink the placeholder, then create a hard link if possible,
1506 a symbolic link otherwise. */
1507 if (unlinkat (chdir_fd, source, 0) != 0)
1508 unlink_error (source);
1509 else if (valid_source
1510 && (linkat (chdir_fd, valid_source, chdir_fd, source, 0)
1513 else if (!ds->is_symlink)
1515 if (linkat (chdir_fd, ds->target, chdir_fd, source, 0) != 0)
1516 link_error (ds->target, source);
1518 else if (symlinkat (ds->target, chdir_fd, source) != 0)
1519 symlink_error (ds->target, source);
1522 struct tar_stat_info st1;
1523 st1.stat.st_mode = ds->mode;
1524 st1.stat.st_uid = ds->uid;
1525 st1.stat.st_gid = ds->gid;
1526 st1.atime = ds->atime;
1527 st1.mtime = ds->mtime;
1528 set_stat (source, &st1, -1, 0, 0, SYMTYPE,
1529 false, AT_SYMLINK_NOFOLLOW);
1530 valid_source = source;
1535 for (sources = ds->sources; sources; )
1537 struct string_list *next = sources->next;
1543 struct delayed_link *next = ds->next;
1549 delayed_link_head = 0;
1552 /* Finish the extraction of an archive. */
1554 extract_finish (void)
1556 /* First, fix the status of ordinary directories that need fixing. */
1557 apply_nonancestor_delayed_set_stat ("", 0);
1559 /* Then, apply delayed links, so that they don't affect delayed
1560 directory status-setting for ordinary directories. */
1561 apply_delayed_links ();
1563 /* Finally, fix the status of directories that are ancestors
1564 of delayed links. */
1565 apply_nonancestor_delayed_set_stat ("", 1);
1569 rename_directory (char *src, char *dst)
1571 if (renameat (chdir_fd, src, chdir_fd, dst) != 0)
1579 if (make_directories (dst, &interdir_made) == 0)
1581 if (renameat (chdir_fd, src, chdir_fd, dst) == 0)
1588 /* FIXME: Fall back to recursive copying */
1594 ERROR ((0, e, _("Cannot rename %s to %s"),