]> Dogcows Code - chaz/tar/blob - src/extract.c
Revamp initial name collection functions to ensure proper argument ordering.
[chaz/tar] / src / extract.c
1 /* Extract files from a tar archive.
2
3 Copyright 1988, 1992-1994, 1996-2001, 2003-2007, 2010, 2012-2013
4 Free Software Foundation, Inc.
5
6 This file is part of GNU tar.
7
8 GNU tar is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 GNU tar is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20
21 Written by John Gilmore, on 1985-11-19. */
22
23 #include <system.h>
24 #include <quotearg.h>
25 #include <errno.h>
26 #include <priv-set.h>
27 #include <root-uid.h>
28 #include <utimens.h>
29
30 #include "common.h"
31
32 static bool we_are_root; /* true if our effective uid == 0 */
33 static mode_t newdir_umask; /* umask when creating new directories */
34 static mode_t current_umask; /* current umask (which is set to 0 if -p) */
35
36 #define ALL_MODE_BITS ((mode_t) ~ (mode_t) 0)
37
38 #if ! HAVE_FCHMOD && ! defined fchmod
39 # define fchmod(fd, mode) (errno = ENOSYS, -1)
40 #endif
41 #if ! HAVE_FCHOWN && ! defined fchown
42 # define fchown(fd, uid, gid) (errno = ENOSYS, -1)
43 #endif
44
45 /* Return true if an error number ERR means the system call is
46 supported in this case. */
47 static bool
48 implemented (int err)
49 {
50 return ! (err == ENOSYS
51 || err == ENOTSUP
52 || (EOPNOTSUPP != ENOTSUP && err == EOPNOTSUPP));
53 }
54
55 /* List of directories whose statuses we need to extract after we've
56 finished extracting their subsidiary files. If you consider each
57 contiguous subsequence of elements of the form [D]?[^D]*, where [D]
58 represents an element where AFTER_LINKS is nonzero and [^D]
59 represents an element where AFTER_LINKS is zero, then the head
60 of the subsequence has the longest name, and each non-head element
61 in the prefix is an ancestor (in the directory hierarchy) of the
62 preceding element. */
63
64 struct delayed_set_stat
65 {
66 /* Next directory in list. */
67 struct delayed_set_stat *next;
68
69 /* Metadata for this directory. */
70 dev_t dev;
71 ino_t ino;
72 mode_t mode; /* The desired mode is MODE & ~ current_umask. */
73 uid_t uid;
74 gid_t gid;
75 struct timespec atime;
76 struct timespec mtime;
77
78 /* An estimate of the directory's current mode, along with a mask
79 specifying which bits of this estimate are known to be correct.
80 If CURRENT_MODE_MASK is zero, CURRENT_MODE's value doesn't
81 matter. */
82 mode_t current_mode;
83 mode_t current_mode_mask;
84
85 /* This directory is an intermediate directory that was created
86 as an ancestor of some other directory; it was not mentioned
87 in the archive, so do not set its uid, gid, atime, or mtime,
88 and don't alter its mode outside of MODE_RWX. */
89 bool interdir;
90
91 /* Whether symbolic links should be followed when accessing the
92 directory. */
93 int atflag;
94
95 /* Do not set the status of this directory until after delayed
96 links are created. */
97 bool after_links;
98
99 /* Directory that the name is relative to. */
100 int change_dir;
101
102 /* extended attributes*/
103 char *cntx_name;
104 char *acls_a_ptr;
105 size_t acls_a_len;
106 char *acls_d_ptr;
107 size_t acls_d_len;
108 size_t xattr_map_size;
109 struct xattr_array *xattr_map;
110 /* Length and contents of name. */
111 size_t file_name_len;
112 char file_name[1];
113 };
114
115 static struct delayed_set_stat *delayed_set_stat_head;
116
117 /* List of links whose creation we have delayed. */
118 struct delayed_link
119 {
120 /* The next delayed link in the list. */
121 struct delayed_link *next;
122
123 /* The device, inode number and birthtime of the placeholder.
124 birthtime.tv_nsec is negative if the birthtime is not available.
125 Don't use mtime as this would allow for false matches if some
126 other process removes the placeholder. Don't use ctime as
127 this would cause race conditions and other screwups, e.g.,
128 when restoring hard-linked symlinks. */
129 dev_t dev;
130 ino_t ino;
131 struct timespec birthtime;
132
133 /* True if the link is symbolic. */
134 bool is_symlink;
135
136 /* The desired metadata, valid only the link is symbolic. */
137 mode_t mode;
138 uid_t uid;
139 gid_t gid;
140 struct timespec atime;
141 struct timespec mtime;
142
143 /* The directory that the sources and target are relative to. */
144 int change_dir;
145
146 /* A list of sources for this link. The sources are all to be
147 hard-linked together. */
148 struct string_list *sources;
149
150 /* SELinux context */
151 char *cntx_name;
152
153 /* ACLs */
154 char *acls_a_ptr;
155 size_t acls_a_len;
156 char *acls_d_ptr;
157 size_t acls_d_len;
158
159 size_t xattr_map_size;
160 struct xattr_array *xattr_map;
161
162 /* The desired target of the desired link. */
163 char target[1];
164 };
165
166 static struct delayed_link *delayed_link_head;
167
168 struct string_list
169 {
170 struct string_list *next;
171 char string[1];
172 };
173
174 /* Set up to extract files. */
175 void
176 extr_init (void)
177 {
178 we_are_root = geteuid () == ROOT_UID;
179 same_permissions_option += we_are_root;
180 same_owner_option += we_are_root;
181
182 /* Option -p clears the kernel umask, so it does not affect proper
183 restoration of file permissions. New intermediate directories will
184 comply with umask at start of program. */
185
186 newdir_umask = umask (0);
187 if (0 < same_permissions_option)
188 current_umask = 0;
189 else
190 {
191 umask (newdir_umask); /* restore the kernel umask */
192 current_umask = newdir_umask;
193 }
194 }
195
196 /* Use fchmod if possible, fchmodat otherwise. */
197 static int
198 fd_chmod (int fd, char const *file, mode_t mode, int atflag)
199 {
200 if (0 <= fd)
201 {
202 int result = fchmod (fd, mode);
203 if (result == 0 || implemented (errno))
204 return result;
205 }
206 return fchmodat (chdir_fd, file, mode, atflag);
207 }
208
209 /* Use fchown if possible, fchownat otherwise. */
210 static int
211 fd_chown (int fd, char const *file, uid_t uid, gid_t gid, int atflag)
212 {
213 if (0 <= fd)
214 {
215 int result = fchown (fd, uid, gid);
216 if (result == 0 || implemented (errno))
217 return result;
218 }
219 return fchownat (chdir_fd, file, uid, gid, atflag);
220 }
221
222 /* Use fstat if possible, fstatat otherwise. */
223 static int
224 fd_stat (int fd, char const *file, struct stat *st, int atflag)
225 {
226 return (0 <= fd
227 ? fstat (fd, st)
228 : fstatat (chdir_fd, file, st, atflag));
229 }
230
231 /* Set the mode for FILE_NAME to MODE.
232 MODE_MASK specifies the bits of MODE that we care about;
233 thus if MODE_MASK is zero, do nothing.
234 If FD is nonnegative, it is a file descriptor for the file.
235 CURRENT_MODE and CURRENT_MODE_MASK specify information known about
236 the file's current mode, using the style of struct delayed_set_stat.
237 TYPEFLAG specifies the type of the file.
238 ATFLAG specifies the flag to use when statting the file. */
239 static void
240 set_mode (char const *file_name,
241 mode_t mode, mode_t mode_mask, int fd,
242 mode_t current_mode, mode_t current_mode_mask,
243 char typeflag, int atflag)
244 {
245 if (((current_mode ^ mode) | ~ current_mode_mask) & mode_mask)
246 {
247 if (MODE_ALL & ~ mode_mask & ~ current_mode_mask)
248 {
249 struct stat st;
250 if (fd_stat (fd, file_name, &st, atflag) != 0)
251 {
252 stat_error (file_name);
253 return;
254 }
255 current_mode = st.st_mode;
256 }
257
258 current_mode &= MODE_ALL;
259 mode = (current_mode & ~ mode_mask) | (mode & mode_mask);
260
261 if (current_mode != mode)
262 {
263 int chmod_errno =
264 fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
265
266 /* On Solaris, chmod may fail if we don't have PRIV_ALL, because
267 setuid-root files would otherwise be a backdoor. See
268 http://opensolaris.org/jive/thread.jspa?threadID=95826
269 (2009-09-03). */
270 if (chmod_errno == EPERM && (mode & S_ISUID)
271 && priv_set_restore_linkdir () == 0)
272 {
273 chmod_errno =
274 fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
275 priv_set_remove_linkdir ();
276 }
277
278 /* Linux fchmodat does not support AT_SYMLINK_NOFOLLOW, and
279 returns ENOTSUP even when operating on non-symlinks, try
280 again with the flag disabled if it does not appear to be
281 supported and if the file is not a symlink. This
282 introduces a race, alas. */
283 if (atflag && typeflag != SYMTYPE && ! implemented (chmod_errno))
284 chmod_errno = fd_chmod (fd, file_name, mode, 0) == 0 ? 0 : errno;
285
286 if (chmod_errno
287 && (typeflag != SYMTYPE || implemented (chmod_errno)))
288 {
289 errno = chmod_errno;
290 chmod_error_details (file_name, mode);
291 }
292 }
293 }
294 }
295
296 /* Check time after successfully setting FILE_NAME's time stamp to T. */
297 static void
298 check_time (char const *file_name, struct timespec t)
299 {
300 if (t.tv_sec <= 0)
301 WARNOPT (WARN_TIMESTAMP,
302 (0, 0, _("%s: implausibly old time stamp %s"),
303 file_name, tartime (t, true)));
304 else if (timespec_cmp (volume_start_time, t) < 0)
305 {
306 struct timespec now;
307 gettime (&now);
308 if (timespec_cmp (now, t) < 0)
309 {
310 char buf[TIMESPEC_STRSIZE_BOUND];
311 struct timespec diff;
312 diff.tv_sec = t.tv_sec - now.tv_sec;
313 diff.tv_nsec = t.tv_nsec - now.tv_nsec;
314 if (diff.tv_nsec < 0)
315 {
316 diff.tv_nsec += BILLION;
317 diff.tv_sec--;
318 }
319 WARNOPT (WARN_TIMESTAMP,
320 (0, 0, _("%s: time stamp %s is %s s in the future"),
321 file_name, tartime (t, true), code_timespec (diff, buf)));
322 }
323 }
324 }
325
326 /* Restore stat attributes (owner, group, mode and times) for
327 FILE_NAME, using information given in *ST.
328 If FD is nonnegative, it is a file descriptor for the file.
329 CURRENT_MODE and CURRENT_MODE_MASK specify information known about
330 the file's current mode, using the style of struct delayed_set_stat.
331 TYPEFLAG specifies the type of the file.
332 If INTERDIR, this is an intermediate directory.
333 ATFLAG specifies the flag to use when statting the file. */
334
335 static void
336 set_stat (char const *file_name,
337 struct tar_stat_info const *st,
338 int fd, mode_t current_mode, mode_t current_mode_mask,
339 char typeflag, bool interdir, int atflag)
340 {
341 /* Do the utime before the chmod because some versions of utime are
342 broken and trash the modes of the file. */
343
344 if (! touch_option && ! interdir)
345 {
346 struct timespec ts[2];
347 if (incremental_option)
348 ts[0] = st->atime;
349 else
350 ts[0].tv_nsec = UTIME_OMIT;
351 ts[1] = st->mtime;
352
353 if (fdutimensat (fd, chdir_fd, file_name, ts, atflag) == 0)
354 {
355 if (incremental_option)
356 check_time (file_name, ts[0]);
357 check_time (file_name, ts[1]);
358 }
359 else if (typeflag != SYMTYPE || implemented (errno))
360 utime_error (file_name);
361 }
362
363 if (0 < same_owner_option && ! interdir)
364 {
365 /* Some systems allow non-root users to give files away. Once this
366 done, it is not possible anymore to change file permissions.
367 However, setting file permissions now would be incorrect, since
368 they would apply to the wrong user, and there would be a race
369 condition. So, don't use systems that allow non-root users to
370 give files away. */
371 uid_t uid = st->stat.st_uid;
372 gid_t gid = st->stat.st_gid;
373
374 if (fd_chown (fd, file_name, uid, gid, atflag) == 0)
375 {
376 /* Changing the owner can clear st_mode bits in some cases. */
377 if ((current_mode | ~ current_mode_mask) & S_IXUGO)
378 current_mode_mask &= ~ (current_mode & (S_ISUID | S_ISGID));
379 }
380 else if (typeflag != SYMTYPE || implemented (errno))
381 chown_error_details (file_name, uid, gid);
382 }
383
384 set_mode (file_name,
385 st->stat.st_mode & ~ current_umask,
386 0 < same_permissions_option && ! interdir ? MODE_ALL : MODE_RWX,
387 fd, current_mode, current_mode_mask, typeflag, atflag);
388
389 /* these three calls must be done *after* fd_chown() call because fd_chown
390 causes that linux capabilities becomes cleared. */
391 xattrs_xattrs_set (st, file_name, typeflag, 1);
392 xattrs_acls_set (st, file_name, typeflag);
393 xattrs_selinux_set (st, file_name, typeflag);
394 }
395
396 /* For each entry H in the leading prefix of entries in HEAD that do
397 not have after_links marked, mark H and fill in its dev and ino
398 members. Assume HEAD && ! HEAD->after_links. */
399 static void
400 mark_after_links (struct delayed_set_stat *head)
401 {
402 struct delayed_set_stat *h = head;
403
404 do
405 {
406 struct stat st;
407 h->after_links = 1;
408
409 if (deref_stat (h->file_name, &st) != 0)
410 stat_error (h->file_name);
411 else
412 {
413 h->dev = st.st_dev;
414 h->ino = st.st_ino;
415 }
416 }
417 while ((h = h->next) && ! h->after_links);
418 }
419
420 /* Remember to restore stat attributes (owner, group, mode and times)
421 for the directory FILE_NAME, using information given in *ST,
422 once we stop extracting files into that directory.
423
424 If ST is null, merely create a placeholder node for an intermediate
425 directory that was created by make_directories.
426
427 NOTICE: this works only if the archive has usual member order, i.e.
428 directory, then the files in that directory. Incremental archive have
429 somewhat reversed order: first go subdirectories, then all other
430 members. To help cope with this case the variable
431 delay_directory_restore_option is set by prepare_to_extract.
432
433 If an archive was explicitely created so that its member order is
434 reversed, some directory timestamps can be restored incorrectly,
435 e.g.:
436 tar --no-recursion -cf archive dir dir/file1 foo dir/file2
437 */
438 static void
439 delay_set_stat (char const *file_name, struct tar_stat_info const *st,
440 mode_t current_mode, mode_t current_mode_mask,
441 mode_t mode, int atflag)
442 {
443 size_t file_name_len = strlen (file_name);
444 struct delayed_set_stat *data =
445 xmalloc (offsetof (struct delayed_set_stat, file_name)
446 + file_name_len + 1);
447 data->next = delayed_set_stat_head;
448 data->mode = mode;
449 if (st)
450 {
451 data->dev = st->stat.st_dev;
452 data->ino = st->stat.st_ino;
453 data->uid = st->stat.st_uid;
454 data->gid = st->stat.st_gid;
455 data->atime = st->atime;
456 data->mtime = st->mtime;
457 }
458 data->file_name_len = file_name_len;
459 data->current_mode = current_mode;
460 data->current_mode_mask = current_mode_mask;
461 data->interdir = ! st;
462 data->atflag = atflag;
463 data->after_links = 0;
464 data->change_dir = chdir_current;
465 data->cntx_name = NULL;
466 if (st)
467 assign_string (&data->cntx_name, st->cntx_name);
468 if (st && st->acls_a_ptr)
469 {
470 data->acls_a_ptr = xmemdup (st->acls_a_ptr, st->acls_a_len + 1);
471 data->acls_a_len = st->acls_a_len;
472 }
473 else
474 {
475 data->acls_a_ptr = NULL;
476 data->acls_a_len = 0;
477 }
478 if (st && st->acls_d_ptr)
479 {
480 data->acls_d_ptr = xmemdup (st->acls_d_ptr, st->acls_d_len + 1);
481 data->acls_d_len = st->acls_d_len;
482 }
483 else
484 {
485 data->acls_d_ptr = NULL;
486 data->acls_d_len = 0;
487 }
488 if (st)
489 xheader_xattr_copy (st, &data->xattr_map, &data->xattr_map_size);
490 else
491 {
492 data->xattr_map = NULL;
493 data->xattr_map_size = 0;
494 }
495 strcpy (data->file_name, file_name);
496 delayed_set_stat_head = data;
497 if (must_be_dot_or_slash (file_name))
498 mark_after_links (data);
499 }
500
501 /* Update the delayed_set_stat info for an intermediate directory
502 created within the file name of DIR. The intermediate directory turned
503 out to be the same as this directory, e.g. due to ".." or symbolic
504 links. *DIR_STAT_INFO is the status of the directory. */
505 static void
506 repair_delayed_set_stat (char const *dir,
507 struct stat const *dir_stat_info)
508 {
509 struct delayed_set_stat *data;
510 for (data = delayed_set_stat_head; data; data = data->next)
511 {
512 struct stat st;
513 if (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 0)
514 {
515 stat_error (data->file_name);
516 return;
517 }
518
519 if (st.st_dev == dir_stat_info->st_dev
520 && st.st_ino == dir_stat_info->st_ino)
521 {
522 data->dev = current_stat_info.stat.st_dev;
523 data->ino = current_stat_info.stat.st_ino;
524 data->mode = current_stat_info.stat.st_mode;
525 data->uid = current_stat_info.stat.st_uid;
526 data->gid = current_stat_info.stat.st_gid;
527 data->atime = current_stat_info.atime;
528 data->mtime = current_stat_info.mtime;
529 data->current_mode = st.st_mode;
530 data->current_mode_mask = ALL_MODE_BITS;
531 data->interdir = false;
532 return;
533 }
534 }
535
536 ERROR ((0, 0, _("%s: Unexpected inconsistency when making directory"),
537 quotearg_colon (dir)));
538 }
539
540 /* After a file/link/directory creation has failed, see if
541 it's because some required directory was not present, and if so,
542 create all required directories. Return zero if all the required
543 directories were created, nonzero (issuing a diagnostic) otherwise.
544 Set *INTERDIR_MADE if at least one directory was created. */
545 static int
546 make_directories (char *file_name, bool *interdir_made)
547 {
548 char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
549 char *cursor; /* points into the file name */
550
551 for (cursor = cursor0; *cursor; cursor++)
552 {
553 mode_t mode;
554 mode_t desired_mode;
555 int status;
556
557 if (! ISSLASH (*cursor))
558 continue;
559
560 /* Avoid mkdir of empty string, if leading or double '/'. */
561
562 if (cursor == cursor0 || ISSLASH (cursor[-1]))
563 continue;
564
565 /* Avoid mkdir where last part of file name is "." or "..". */
566
567 if (cursor[-1] == '.'
568 && (cursor == cursor0 + 1 || ISSLASH (cursor[-2])
569 || (cursor[-2] == '.'
570 && (cursor == cursor0 + 2 || ISSLASH (cursor[-3])))))
571 continue;
572
573 *cursor = '\0'; /* truncate the name there */
574 desired_mode = MODE_RWX & ~ newdir_umask;
575 mode = desired_mode | (we_are_root ? 0 : MODE_WXUSR);
576 status = mkdirat (chdir_fd, file_name, mode);
577
578 if (status == 0)
579 {
580 /* Create a struct delayed_set_stat even if
581 mode == desired_mode, because
582 repair_delayed_set_stat may need to update the struct. */
583 delay_set_stat (file_name,
584 0, mode & ~ current_umask, MODE_RWX,
585 desired_mode, AT_SYMLINK_NOFOLLOW);
586
587 print_for_mkdir (file_name, cursor - file_name, desired_mode);
588 *interdir_made = true;
589 }
590 else if (errno == EEXIST)
591 status = 0;
592 else
593 {
594 /* Check whether the desired file exists. Even when the
595 file exists, mkdir can fail with some errno value E other
596 than EEXIST, so long as E describes an error condition
597 that also applies. */
598 int e = errno;
599 struct stat st;
600 status = fstatat (chdir_fd, file_name, &st, 0);
601 if (status)
602 {
603 errno = e;
604 mkdir_error (file_name);
605 }
606 }
607
608 *cursor = '/';
609 if (status)
610 return status;
611 }
612
613 return 0;
614 }
615
616 /* Return true if FILE_NAME (with status *STP, if STP) is not a
617 directory, and has a time stamp newer than (or equal to) that of
618 TAR_STAT. */
619 static bool
620 file_newer_p (const char *file_name, struct stat const *stp,
621 struct tar_stat_info *tar_stat)
622 {
623 struct stat st;
624
625 if (!stp)
626 {
627 if (deref_stat (file_name, &st) != 0)
628 {
629 if (errno != ENOENT)
630 {
631 stat_warn (file_name);
632 /* Be safer: if the file exists, assume it is newer. */
633 return true;
634 }
635 return false;
636 }
637 stp = &st;
638 }
639
640 return (! S_ISDIR (stp->st_mode)
641 && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (stp)) <= 0);
642 }
643
644 #define RECOVER_NO 0
645 #define RECOVER_OK 1
646 #define RECOVER_SKIP 2
647
648 /* Attempt repairing what went wrong with the extraction. Delete an
649 already existing file or create missing intermediate directories.
650 Return RECOVER_OK if we somewhat increased our chances at a successful
651 extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the
652 caller should skip extraction of that member. The value of errno is
653 properly restored on returning RECOVER_NO.
654
655 If REGULAR, the caller was trying to extract onto a regular file.
656
657 Set *INTERDIR_MADE if an intermediate directory is made as part of
658 the recovery process. */
659
660 static int
661 maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
662 {
663 int e = errno;
664 struct stat st;
665 struct stat const *stp = 0;
666
667 if (*interdir_made)
668 return RECOVER_NO;
669
670 switch (e)
671 {
672 case ELOOP:
673
674 /* With open ("symlink", O_NOFOLLOW|...), POSIX says errno == ELOOP,
675 but some operating systems do not conform to the standard. */
676 #ifdef EFTYPE
677 /* NetBSD uses errno == EFTYPE; see <http://gnats.netbsd.org/43154>. */
678 case EFTYPE:
679 #endif
680 /* FreeBSD 8.1 uses errno == EMLINK. */
681 case EMLINK:
682 /* Tru64 5.1B uses errno == ENOTSUP. */
683 case ENOTSUP:
684
685 if (! regular
686 || old_files_option != OVERWRITE_OLD_FILES || dereference_option)
687 break;
688 if (strchr (file_name, '/'))
689 {
690 if (deref_stat (file_name, &st) != 0)
691 break;
692 stp = &st;
693 }
694
695 /* The caller tried to open a symbolic link with O_NOFOLLOW.
696 Fall through, treating it as an already-existing file. */
697
698 case EEXIST:
699 /* Remove an old file, if the options allow this. */
700
701 switch (old_files_option)
702 {
703 case SKIP_OLD_FILES:
704 WARNOPT (WARN_EXISTING_FILE,
705 (0, 0, _("%s: skipping existing file"), file_name));
706 return RECOVER_SKIP;
707
708 case KEEP_OLD_FILES:
709 return RECOVER_NO;
710
711 case KEEP_NEWER_FILES:
712 if (file_newer_p (file_name, stp, &current_stat_info))
713 break;
714 /* FALL THROUGH */
715
716 case DEFAULT_OLD_FILES:
717 case NO_OVERWRITE_DIR_OLD_FILES:
718 case OVERWRITE_OLD_FILES:
719 if (0 < remove_any_file (file_name, ORDINARY_REMOVE_OPTION))
720 return RECOVER_OK;
721 break;
722
723 case UNLINK_FIRST_OLD_FILES:
724 break;
725 }
726
727 case ENOENT:
728 /* Attempt creating missing intermediate directories. */
729 if (make_directories (file_name, interdir_made) == 0 && *interdir_made)
730 return RECOVER_OK;
731 break;
732
733 default:
734 /* Just say we can't do anything about it... */
735 break;
736 }
737
738 errno = e;
739 return RECOVER_NO;
740 }
741
742 /* Restore stat extended attributes (xattr) for FILE_NAME, using information
743 given in *ST. Restore before extraction because they may affect file layout
744 (e.g. on Lustre distributed parallel filesystem - setting info about how many
745 servers is this file striped over, stripe size, mirror copies, etc.
746 in advance dramatically improves the following performance of reading and
747 writing a file). If not restoring permissions, invert the INVERT_PERMISSIONS
748 bits from the file's current permissions. TYPEFLAG specifies the type of the
749 file. FILE_CREATED indicates set_xattr has created the file */
750 static int
751 set_xattr (char const *file_name, struct tar_stat_info const *st,
752 mode_t invert_permissions, char typeflag, int *file_created)
753 {
754 int status = 0;
755
756 #ifdef HAVE_XATTRS
757 bool interdir_made = false;
758
759 if ((xattrs_option > 0) && st->xattr_map_size)
760 {
761 mode_t mode = current_stat_info.stat.st_mode & MODE_RWX & ~ current_umask;
762
763 do
764 status = mknodat (chdir_fd, file_name, mode ^ invert_permissions, 0);
765 while (status && maybe_recoverable ((char *)file_name, false,
766 &interdir_made));
767
768 xattrs_xattrs_set (st, file_name, typeflag, 0);
769 *file_created = 1;
770 }
771 #endif
772
773 return(status);
774 }
775
776 /* Fix the statuses of all directories whose statuses need fixing, and
777 which are not ancestors of FILE_NAME. If AFTER_LINKS is
778 nonzero, do this for all such directories; otherwise, stop at the
779 first directory that is marked to be fixed up only after delayed
780 links are applied. */
781 static void
782 apply_nonancestor_delayed_set_stat (char const *file_name, bool after_links)
783 {
784 size_t file_name_len = strlen (file_name);
785 bool check_for_renamed_directories = 0;
786
787 while (delayed_set_stat_head)
788 {
789 struct delayed_set_stat *data = delayed_set_stat_head;
790 bool skip_this_one = 0;
791 struct stat st;
792 mode_t current_mode = data->current_mode;
793 mode_t current_mode_mask = data->current_mode_mask;
794
795 check_for_renamed_directories |= data->after_links;
796
797 if (after_links < data->after_links
798 || (data->file_name_len < file_name_len
799 && file_name[data->file_name_len]
800 && (ISSLASH (file_name[data->file_name_len])
801 || ISSLASH (file_name[data->file_name_len - 1]))
802 && memcmp (file_name, data->file_name, data->file_name_len) == 0))
803 break;
804
805 chdir_do (data->change_dir);
806
807 if (check_for_renamed_directories)
808 {
809 if (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 0)
810 {
811 stat_error (data->file_name);
812 skip_this_one = 1;
813 }
814 else
815 {
816 current_mode = st.st_mode;
817 current_mode_mask = ALL_MODE_BITS;
818 if (! (st.st_dev == data->dev && st.st_ino == data->ino))
819 {
820 ERROR ((0, 0,
821 _("%s: Directory renamed before its status could be extracted"),
822 quotearg_colon (data->file_name)));
823 skip_this_one = 1;
824 }
825 }
826 }
827
828 if (! skip_this_one)
829 {
830 struct tar_stat_info sb;
831 sb.stat.st_mode = data->mode;
832 sb.stat.st_uid = data->uid;
833 sb.stat.st_gid = data->gid;
834 sb.atime = data->atime;
835 sb.mtime = data->mtime;
836 sb.cntx_name = data->cntx_name;
837 sb.acls_a_ptr = data->acls_a_ptr;
838 sb.acls_a_len = data->acls_a_len;
839 sb.acls_d_ptr = data->acls_d_ptr;
840 sb.acls_d_len = data->acls_d_len;
841 sb.xattr_map = data->xattr_map;
842 sb.xattr_map_size = data->xattr_map_size;
843 set_stat (data->file_name, &sb,
844 -1, current_mode, current_mode_mask,
845 DIRTYPE, data->interdir, data->atflag);
846 }
847
848 delayed_set_stat_head = data->next;
849 xheader_xattr_free (data->xattr_map, data->xattr_map_size);
850 free (data->cntx_name);
851 free (data->acls_a_ptr);
852 free (data->acls_d_ptr);
853 free (data);
854 }
855 }
856
857 \f
858
859 /* Extractor functions for various member types */
860
861 static int
862 extract_dir (char *file_name, int typeflag)
863 {
864 int status;
865 mode_t mode;
866 mode_t current_mode = 0;
867 mode_t current_mode_mask = 0;
868 int atflag = 0;
869 bool interdir_made = false;
870
871 /* Save 'root device' to avoid purging mount points. */
872 if (one_file_system_option && root_device == 0)
873 {
874 struct stat st;
875
876 if (fstatat (chdir_fd, ".", &st, 0) != 0)
877 stat_diag (".");
878 else
879 root_device = st.st_dev;
880 }
881
882 if (incremental_option)
883 /* Read the entry and delete files that aren't listed in the archive. */
884 purge_directory (file_name);
885 else if (typeflag == GNUTYPE_DUMPDIR)
886 skip_member ();
887
888 /* If ownership or permissions will be restored later, create the
889 directory with restrictive permissions at first, so that in the
890 meantime processes owned by other users do not inadvertently
891 create files under this directory that inherit the wrong owner,
892 group, or permissions from the directory. If not root, though,
893 make the directory writeable and searchable at first, so that
894 files can be created under it. */
895 mode = ((current_stat_info.stat.st_mode
896 & (0 < same_owner_option || 0 < same_permissions_option
897 ? S_IRWXU
898 : MODE_RWX))
899 | (we_are_root ? 0 : MODE_WXUSR));
900
901 for (;;)
902 {
903 status = mkdirat (chdir_fd, file_name, mode);
904 if (status == 0)
905 {
906 current_mode = mode & ~ current_umask;
907 current_mode_mask = MODE_RWX;
908 atflag = AT_SYMLINK_NOFOLLOW;
909 break;
910 }
911
912 if (errno == EEXIST
913 && (interdir_made
914 || old_files_option == DEFAULT_OLD_FILES
915 || old_files_option == OVERWRITE_OLD_FILES))
916 {
917 struct stat st;
918 if (deref_stat (file_name, &st) == 0)
919 {
920 current_mode = st.st_mode;
921 current_mode_mask = ALL_MODE_BITS;
922
923 if (S_ISDIR (current_mode))
924 {
925 if (interdir_made)
926 {
927 repair_delayed_set_stat (file_name, &st);
928 return 0;
929 }
930 break;
931 }
932 }
933 errno = EEXIST;
934 }
935
936 switch (maybe_recoverable (file_name, false, &interdir_made))
937 {
938 case RECOVER_OK:
939 continue;
940
941 case RECOVER_SKIP:
942 break;
943
944 case RECOVER_NO:
945 if (errno != EEXIST)
946 {
947 mkdir_error (file_name);
948 return 1;
949 }
950 break;
951 }
952 break;
953 }
954
955 if (status == 0
956 || old_files_option == DEFAULT_OLD_FILES
957 || old_files_option == OVERWRITE_OLD_FILES)
958 delay_set_stat (file_name, &current_stat_info,
959 current_mode, current_mode_mask,
960 current_stat_info.stat.st_mode, atflag);
961 return status;
962 }
963
964
965
966 static int
967 open_output_file (char const *file_name, int typeflag, mode_t mode,
968 int file_created, mode_t *current_mode,
969 mode_t *current_mode_mask)
970 {
971 int fd;
972 bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES;
973 int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK
974 | O_CREAT
975 | (overwriting_old_files
976 ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW)
977 : O_EXCL));
978
979 /* File might be created in set_xattr. So clear O_EXCL to avoid open() fail */
980 if (file_created)
981 openflag = openflag & ~O_EXCL;
982
983 if (typeflag == CONTTYPE)
984 {
985 static int conttype_diagnosed;
986
987 if (!conttype_diagnosed)
988 {
989 conttype_diagnosed = 1;
990 WARNOPT (WARN_CONTIGUOUS_CAST,
991 (0, 0, _("Extracting contiguous files as regular files")));
992 }
993 }
994
995 /* If O_NOFOLLOW is needed but does not work, check for a symlink
996 separately. There's a race condition, but that cannot be avoided
997 on hosts lacking O_NOFOLLOW. */
998 if (! HAVE_WORKING_O_NOFOLLOW
999 && overwriting_old_files && ! dereference_option)
1000 {
1001 struct stat st;
1002 if (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0
1003 && S_ISLNK (st.st_mode))
1004 {
1005 errno = ELOOP;
1006 return -1;
1007 }
1008 }
1009
1010 fd = openat (chdir_fd, file_name, openflag, mode);
1011 if (0 <= fd)
1012 {
1013 if (overwriting_old_files)
1014 {
1015 struct stat st;
1016 if (fstat (fd, &st) != 0)
1017 {
1018 int e = errno;
1019 close (fd);
1020 errno = e;
1021 return -1;
1022 }
1023 if (! S_ISREG (st.st_mode))
1024 {
1025 close (fd);
1026 errno = EEXIST;
1027 return -1;
1028 }
1029 *current_mode = st.st_mode;
1030 *current_mode_mask = ALL_MODE_BITS;
1031 }
1032 else
1033 {
1034 *current_mode = mode & ~ current_umask;
1035 *current_mode_mask = MODE_RWX;
1036 }
1037 }
1038
1039 return fd;
1040 }
1041
1042 static int
1043 extract_file (char *file_name, int typeflag)
1044 {
1045 int fd;
1046 off_t size;
1047 union block *data_block;
1048 int status;
1049 size_t count;
1050 size_t written;
1051 bool interdir_made = false;
1052 mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX
1053 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
1054 mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO)
1055 : 0;
1056 mode_t current_mode = 0;
1057 mode_t current_mode_mask = 0;
1058
1059 if (to_stdout_option)
1060 fd = STDOUT_FILENO;
1061 else if (to_command_option)
1062 {
1063 fd = sys_exec_command (file_name, 'f', &current_stat_info);
1064 if (fd < 0)
1065 {
1066 skip_member ();
1067 return 0;
1068 }
1069 }
1070 else
1071 {
1072 int file_created = 0;
1073 if (set_xattr (file_name, &current_stat_info, invert_permissions,
1074 typeflag, &file_created))
1075 {
1076 skip_member ();
1077 open_error (file_name);
1078 return 1;
1079 }
1080
1081 while ((fd = open_output_file (file_name, typeflag, mode,
1082 file_created, &current_mode,
1083 &current_mode_mask))
1084 < 0)
1085 {
1086 int recover = maybe_recoverable (file_name, true, &interdir_made);
1087 if (recover != RECOVER_OK)
1088 {
1089 skip_member ();
1090 if (recover == RECOVER_SKIP)
1091 return 0;
1092 open_error (file_name);
1093 return 1;
1094 }
1095 }
1096 }
1097
1098 mv_begin_read (&current_stat_info);
1099 if (current_stat_info.is_sparse)
1100 sparse_extract_file (fd, &current_stat_info, &size);
1101 else
1102 for (size = current_stat_info.stat.st_size; size > 0; )
1103 {
1104 mv_size_left (size);
1105
1106 /* Locate data, determine max length writeable, write it,
1107 block that we have used the data, then check if the write
1108 worked. */
1109
1110 data_block = find_next_block ();
1111 if (! data_block)
1112 {
1113 ERROR ((0, 0, _("Unexpected EOF in archive")));
1114 break; /* FIXME: What happens, then? */
1115 }
1116
1117 written = available_space_after (data_block);
1118
1119 if (written > size)
1120 written = size;
1121 errno = 0;
1122 count = blocking_write (fd, data_block->buffer, written);
1123 size -= written;
1124
1125 set_next_block_after ((union block *)
1126 (data_block->buffer + written - 1));
1127 if (count != written)
1128 {
1129 if (!to_command_option)
1130 write_error_details (file_name, count, written);
1131 /* FIXME: shouldn't we restore from backup? */
1132 break;
1133 }
1134 }
1135
1136 skip_file (size);
1137
1138 mv_end ();
1139
1140 /* If writing to stdout, don't try to do anything to the filename;
1141 it doesn't exist, or we don't want to touch it anyway. */
1142
1143 if (to_stdout_option)
1144 return 0;
1145
1146 if (! to_command_option)
1147 set_stat (file_name, &current_stat_info, fd,
1148 current_mode, current_mode_mask, typeflag, false,
1149 (old_files_option == OVERWRITE_OLD_FILES
1150 ? 0 : AT_SYMLINK_NOFOLLOW));
1151
1152 status = close (fd);
1153 if (status < 0)
1154 close_error (file_name);
1155
1156 if (to_command_option)
1157 sys_wait_command ();
1158
1159 return status;
1160 }
1161
1162 /* Create a placeholder file with name FILE_NAME, which will be
1163 replaced after other extraction is done by a symbolic link if
1164 IS_SYMLINK is true, and by a hard link otherwise. Set
1165 *INTERDIR_MADE if an intermediate directory is made in the
1166 process. */
1167
1168 static int
1169 create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made)
1170 {
1171 int fd;
1172 struct stat st;
1173
1174 while ((fd = openat (chdir_fd, file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0)
1175 {
1176 switch (maybe_recoverable (file_name, false, interdir_made))
1177 {
1178 case RECOVER_OK:
1179 continue;
1180
1181 case RECOVER_SKIP:
1182 return 0;
1183
1184 case RECOVER_NO:
1185 open_error (file_name);
1186 return -1;
1187 }
1188 }
1189
1190 if (fstat (fd, &st) != 0)
1191 {
1192 stat_error (file_name);
1193 close (fd);
1194 }
1195 else if (close (fd) != 0)
1196 close_error (file_name);
1197 else
1198 {
1199 struct delayed_set_stat *h;
1200 struct delayed_link *p =
1201 xmalloc (offsetof (struct delayed_link, target)
1202 + strlen (current_stat_info.link_name)
1203 + 1);
1204 p->next = delayed_link_head;
1205 delayed_link_head = p;
1206 p->dev = st.st_dev;
1207 p->ino = st.st_ino;
1208 p->birthtime = get_stat_birthtime (&st);
1209 p->is_symlink = is_symlink;
1210 if (is_symlink)
1211 {
1212 p->mode = current_stat_info.stat.st_mode;
1213 p->uid = current_stat_info.stat.st_uid;
1214 p->gid = current_stat_info.stat.st_gid;
1215 p->atime = current_stat_info.atime;
1216 p->mtime = current_stat_info.mtime;
1217 }
1218 p->change_dir = chdir_current;
1219 p->sources = xmalloc (offsetof (struct string_list, string)
1220 + strlen (file_name) + 1);
1221 p->sources->next = 0;
1222 strcpy (p->sources->string, file_name);
1223 p->cntx_name = NULL;
1224 assign_string (&p->cntx_name, current_stat_info.cntx_name);
1225 p->acls_a_ptr = NULL;
1226 p->acls_a_len = 0;
1227 p->acls_d_ptr = NULL;
1228 p->acls_d_len = 0;
1229 xheader_xattr_copy (&current_stat_info, &p->xattr_map, &p->xattr_map_size);
1230 strcpy (p->target, current_stat_info.link_name);
1231
1232 h = delayed_set_stat_head;
1233 if (h && ! h->after_links
1234 && strncmp (file_name, h->file_name, h->file_name_len) == 0
1235 && ISSLASH (file_name[h->file_name_len])
1236 && (last_component (file_name) == file_name + h->file_name_len + 1))
1237 mark_after_links (h);
1238
1239 return 0;
1240 }
1241
1242 return -1;
1243 }
1244
1245 static int
1246 extract_link (char *file_name, int typeflag)
1247 {
1248 bool interdir_made = false;
1249 char const *link_name;
1250 int rc;
1251
1252 link_name = current_stat_info.link_name;
1253
1254 if (! absolute_names_option && contains_dot_dot (link_name))
1255 return create_placeholder_file (file_name, false, &interdir_made);
1256
1257 do
1258 {
1259 struct stat st1, st2;
1260 int e;
1261 int status = linkat (chdir_fd, link_name, chdir_fd, file_name, 0);
1262 e = errno;
1263
1264 if (status == 0)
1265 {
1266 struct delayed_link *ds = delayed_link_head;
1267 if (ds
1268 && fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW) == 0)
1269 for (; ds; ds = ds->next)
1270 if (ds->change_dir == chdir_current
1271 && ds->dev == st1.st_dev
1272 && ds->ino == st1.st_ino
1273 && (timespec_cmp (ds->birthtime, get_stat_birthtime (&st1))
1274 == 0))
1275 {
1276 struct string_list *p = xmalloc (offsetof (struct string_list, string)
1277 + strlen (file_name) + 1);
1278 strcpy (p->string, file_name);
1279 p->next = ds->sources;
1280 ds->sources = p;
1281 break;
1282 }
1283 return 0;
1284 }
1285 else if ((e == EEXIST && strcmp (link_name, file_name) == 0)
1286 || ((fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW)
1287 == 0)
1288 && (fstatat (chdir_fd, file_name, &st2, AT_SYMLINK_NOFOLLOW)
1289 == 0)
1290 && st1.st_dev == st2.st_dev
1291 && st1.st_ino == st2.st_ino))
1292 return 0;
1293
1294 errno = e;
1295 }
1296 while ((rc = maybe_recoverable (file_name, false, &interdir_made))
1297 == RECOVER_OK);
1298
1299 if (rc == RECOVER_SKIP)
1300 return 0;
1301 if (!(incremental_option && errno == EEXIST))
1302 {
1303 link_error (link_name, file_name);
1304 return 1;
1305 }
1306 return 0;
1307 }
1308
1309 static int
1310 extract_symlink (char *file_name, int typeflag)
1311 {
1312 #ifdef HAVE_SYMLINK
1313 bool interdir_made = false;
1314
1315 if (! absolute_names_option
1316 && (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name)
1317 || contains_dot_dot (current_stat_info.link_name)))
1318 return create_placeholder_file (file_name, true, &interdir_made);
1319
1320 while (symlinkat (current_stat_info.link_name, chdir_fd, file_name) != 0)
1321 switch (maybe_recoverable (file_name, false, &interdir_made))
1322 {
1323 case RECOVER_OK:
1324 continue;
1325
1326 case RECOVER_SKIP:
1327 return 0;
1328
1329 case RECOVER_NO:
1330 symlink_error (current_stat_info.link_name, file_name);
1331 return -1;
1332 }
1333
1334 set_stat (file_name, &current_stat_info, -1, 0, 0,
1335 SYMTYPE, false, AT_SYMLINK_NOFOLLOW);
1336 return 0;
1337
1338 #else
1339 static int warned_once;
1340
1341 if (!warned_once)
1342 {
1343 warned_once = 1;
1344 WARNOPT (WARN_SYMLINK_CAST,
1345 (0, 0,
1346 _("Attempting extraction of symbolic links as hard links")));
1347 }
1348 return extract_link (file_name, typeflag);
1349 #endif
1350 }
1351
1352 #if S_IFCHR || S_IFBLK
1353 static int
1354 extract_node (char *file_name, int typeflag)
1355 {
1356 bool interdir_made = false;
1357 mode_t mode = (current_stat_info.stat.st_mode & (MODE_RWX | S_IFBLK | S_IFCHR)
1358 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
1359
1360 while (mknodat (chdir_fd, file_name, mode, current_stat_info.stat.st_rdev)
1361 != 0)
1362 switch (maybe_recoverable (file_name, false, &interdir_made))
1363 {
1364 case RECOVER_OK:
1365 continue;
1366
1367 case RECOVER_SKIP:
1368 return 0;
1369
1370 case RECOVER_NO:
1371 mknod_error (file_name);
1372 return -1;
1373 }
1374
1375 set_stat (file_name, &current_stat_info, -1,
1376 mode & ~ current_umask, MODE_RWX,
1377 typeflag, false, AT_SYMLINK_NOFOLLOW);
1378 return 0;
1379 }
1380 #endif
1381
1382 #if HAVE_MKFIFO || defined mkfifo
1383 static int
1384 extract_fifo (char *file_name, int typeflag)
1385 {
1386 bool interdir_made = false;
1387 mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX
1388 & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0));
1389
1390 while (mkfifoat (chdir_fd, file_name, mode) != 0)
1391 switch (maybe_recoverable (file_name, false, &interdir_made))
1392 {
1393 case RECOVER_OK:
1394 continue;
1395
1396 case RECOVER_SKIP:
1397 return 0;
1398
1399 case RECOVER_NO:
1400 mkfifo_error (file_name);
1401 return -1;
1402 }
1403
1404 set_stat (file_name, &current_stat_info, -1,
1405 mode & ~ current_umask, MODE_RWX,
1406 typeflag, false, AT_SYMLINK_NOFOLLOW);
1407 return 0;
1408 }
1409 #endif
1410
1411 static int
1412 extract_volhdr (char *file_name, int typeflag)
1413 {
1414 skip_member ();
1415 return 0;
1416 }
1417
1418 static int
1419 extract_failure (char *file_name, int typeflag)
1420 {
1421 return 1;
1422 }
1423
1424 static int
1425 extract_skip (char *file_name, int typeflag)
1426 {
1427 skip_member ();
1428 return 0;
1429 }
1430
1431 typedef int (*tar_extractor_t) (char *file_name, int typeflag);
1432
1433 \f
1434
1435 /* Prepare to extract a file. Find extractor function.
1436 Return zero if extraction should not proceed. */
1437
1438 static int
1439 prepare_to_extract (char const *file_name, int typeflag, tar_extractor_t *fun)
1440 {
1441 int rc = 1;
1442
1443 if (EXTRACT_OVER_PIPE)
1444 rc = 0;
1445
1446 /* Select the extractor */
1447 switch (typeflag)
1448 {
1449 case GNUTYPE_SPARSE:
1450 *fun = extract_file;
1451 rc = 1;
1452 break;
1453
1454 case AREGTYPE:
1455 case REGTYPE:
1456 case CONTTYPE:
1457 /* Appears to be a file. But BSD tar uses the convention that a slash
1458 suffix means a directory. */
1459 if (current_stat_info.had_trailing_slash)
1460 *fun = extract_dir;
1461 else
1462 {
1463 *fun = extract_file;
1464 rc = 1;
1465 }
1466 break;
1467
1468 case SYMTYPE:
1469 *fun = extract_symlink;
1470 break;
1471
1472 case LNKTYPE:
1473 *fun = extract_link;
1474 break;
1475
1476 #if S_IFCHR
1477 case CHRTYPE:
1478 current_stat_info.stat.st_mode |= S_IFCHR;
1479 *fun = extract_node;
1480 break;
1481 #endif
1482
1483 #if S_IFBLK
1484 case BLKTYPE:
1485 current_stat_info.stat.st_mode |= S_IFBLK;
1486 *fun = extract_node;
1487 break;
1488 #endif
1489
1490 #if HAVE_MKFIFO || defined mkfifo
1491 case FIFOTYPE:
1492 *fun = extract_fifo;
1493 break;
1494 #endif
1495
1496 case DIRTYPE:
1497 case GNUTYPE_DUMPDIR:
1498 *fun = extract_dir;
1499 if (current_stat_info.is_dumpdir)
1500 delay_directory_restore_option = true;
1501 break;
1502
1503 case GNUTYPE_VOLHDR:
1504 *fun = extract_volhdr;
1505 break;
1506
1507 case GNUTYPE_MULTIVOL:
1508 ERROR ((0, 0,
1509 _("%s: Cannot extract -- file is continued from another volume"),
1510 quotearg_colon (current_stat_info.file_name)));
1511 *fun = extract_skip;
1512 break;
1513
1514 case GNUTYPE_LONGNAME:
1515 case GNUTYPE_LONGLINK:
1516 ERROR ((0, 0, _("Unexpected long name header")));
1517 *fun = extract_failure;
1518 break;
1519
1520 default:
1521 WARNOPT (WARN_UNKNOWN_CAST,
1522 (0, 0,
1523 _("%s: Unknown file type '%c', extracted as normal file"),
1524 quotearg_colon (file_name), typeflag));
1525 *fun = extract_file;
1526 }
1527
1528 /* Determine whether the extraction should proceed */
1529 if (rc == 0)
1530 return 0;
1531
1532 switch (old_files_option)
1533 {
1534 case UNLINK_FIRST_OLD_FILES:
1535 if (!remove_any_file (file_name,
1536 recursive_unlink_option ? RECURSIVE_REMOVE_OPTION
1537 : ORDINARY_REMOVE_OPTION)
1538 && errno && errno != ENOENT)
1539 {
1540 unlink_error (file_name);
1541 return 0;
1542 }
1543 break;
1544
1545 case KEEP_NEWER_FILES:
1546 if (file_newer_p (file_name, 0, &current_stat_info))
1547 {
1548 WARNOPT (WARN_IGNORE_NEWER,
1549 (0, 0, _("Current %s is newer or same age"),
1550 quote (file_name)));
1551 return 0;
1552 }
1553 break;
1554
1555 default:
1556 break;
1557 }
1558
1559 return 1;
1560 }
1561
1562 /* Extract a file from the archive. */
1563 void
1564 extract_archive (void)
1565 {
1566 char typeflag;
1567 tar_extractor_t fun;
1568
1569 fatal_exit_hook = extract_finish;
1570
1571 set_next_block_after (current_header);
1572
1573 if (!current_stat_info.file_name[0]
1574 || (interactive_option
1575 && !confirm ("extract", current_stat_info.file_name)))
1576 {
1577 skip_member ();
1578 return;
1579 }
1580
1581 /* Print the block from current_header and current_stat. */
1582 if (verbose_option)
1583 print_header (&current_stat_info, current_header, -1);
1584
1585 /* Restore stats for all non-ancestor directories, unless
1586 it is an incremental archive.
1587 (see NOTICE in the comment to delay_set_stat above) */
1588 if (!delay_directory_restore_option)
1589 {
1590 int dir = chdir_current;
1591 apply_nonancestor_delayed_set_stat (current_stat_info.file_name, 0);
1592 chdir_do (dir);
1593 }
1594
1595 /* Take a safety backup of a previously existing file. */
1596
1597 if (backup_option)
1598 if (!maybe_backup_file (current_stat_info.file_name, 0))
1599 {
1600 int e = errno;
1601 ERROR ((0, e, _("%s: Was unable to backup this file"),
1602 quotearg_colon (current_stat_info.file_name)));
1603 skip_member ();
1604 return;
1605 }
1606
1607 /* Extract the archive entry according to its type. */
1608 /* KLUDGE */
1609 typeflag = sparse_member_p (&current_stat_info) ?
1610 GNUTYPE_SPARSE : current_header->header.typeflag;
1611
1612 if (prepare_to_extract (current_stat_info.file_name, typeflag, &fun))
1613 {
1614 if (fun && (*fun) (current_stat_info.file_name, typeflag)
1615 && backup_option)
1616 undo_last_backup ();
1617 }
1618 else
1619 skip_member ();
1620
1621 }
1622
1623 /* Extract the links whose final extraction were delayed. */
1624 static void
1625 apply_delayed_links (void)
1626 {
1627 struct delayed_link *ds;
1628
1629 for (ds = delayed_link_head; ds; )
1630 {
1631 struct string_list *sources = ds->sources;
1632 char const *valid_source = 0;
1633
1634 chdir_do (ds->change_dir);
1635
1636 for (sources = ds->sources; sources; sources = sources->next)
1637 {
1638 char const *source = sources->string;
1639 struct stat st;
1640
1641 /* Make sure the placeholder file is still there. If not,
1642 don't create a link, as the placeholder was probably
1643 removed by a later extraction. */
1644 if (fstatat (chdir_fd, source, &st, AT_SYMLINK_NOFOLLOW) == 0
1645 && st.st_dev == ds->dev
1646 && st.st_ino == ds->ino
1647 && timespec_cmp (get_stat_birthtime (&st), ds->birthtime) == 0)
1648 {
1649 /* Unlink the placeholder, then create a hard link if possible,
1650 a symbolic link otherwise. */
1651 if (unlinkat (chdir_fd, source, 0) != 0)
1652 unlink_error (source);
1653 else if (valid_source
1654 && (linkat (chdir_fd, valid_source, chdir_fd, source, 0)
1655 == 0))
1656 ;
1657 else if (!ds->is_symlink)
1658 {
1659 if (linkat (chdir_fd, ds->target, chdir_fd, source, 0) != 0)
1660 link_error (ds->target, source);
1661 }
1662 else if (symlinkat (ds->target, chdir_fd, source) != 0)
1663 symlink_error (ds->target, source);
1664 else
1665 {
1666 struct tar_stat_info st1;
1667 st1.stat.st_mode = ds->mode;
1668 st1.stat.st_uid = ds->uid;
1669 st1.stat.st_gid = ds->gid;
1670 st1.atime = ds->atime;
1671 st1.mtime = ds->mtime;
1672 st1.cntx_name = ds->cntx_name;
1673 st1.acls_a_ptr = ds->acls_a_ptr;
1674 st1.acls_a_len = ds->acls_a_len;
1675 st1.acls_d_ptr = ds->acls_d_ptr;
1676 st1.acls_d_len = ds->acls_d_len;
1677 st1.xattr_map = ds->xattr_map;
1678 st1.xattr_map_size = ds->xattr_map_size;
1679 set_stat (source, &st1, -1, 0, 0, SYMTYPE,
1680 false, AT_SYMLINK_NOFOLLOW);
1681 valid_source = source;
1682 }
1683 }
1684 }
1685
1686 for (sources = ds->sources; sources; )
1687 {
1688 struct string_list *next = sources->next;
1689 free (sources);
1690 sources = next;
1691 }
1692
1693 xheader_xattr_free (ds->xattr_map, ds->xattr_map_size);
1694 free (ds->cntx_name);
1695
1696 {
1697 struct delayed_link *next = ds->next;
1698 free (ds);
1699 ds = next;
1700 }
1701 }
1702
1703 delayed_link_head = 0;
1704 }
1705
1706 /* Finish the extraction of an archive. */
1707 void
1708 extract_finish (void)
1709 {
1710 /* First, fix the status of ordinary directories that need fixing. */
1711 apply_nonancestor_delayed_set_stat ("", 0);
1712
1713 /* Then, apply delayed links, so that they don't affect delayed
1714 directory status-setting for ordinary directories. */
1715 apply_delayed_links ();
1716
1717 /* Finally, fix the status of directories that are ancestors
1718 of delayed links. */
1719 apply_nonancestor_delayed_set_stat ("", 1);
1720 }
1721
1722 bool
1723 rename_directory (char *src, char *dst)
1724 {
1725 if (renameat (chdir_fd, src, chdir_fd, dst) != 0)
1726 {
1727 int e = errno;
1728 bool interdir_made;
1729
1730 switch (e)
1731 {
1732 case ENOENT:
1733 if (make_directories (dst, &interdir_made) == 0)
1734 {
1735 if (renameat (chdir_fd, src, chdir_fd, dst) == 0)
1736 return true;
1737 e = errno;
1738 }
1739 break;
1740
1741 case EXDEV:
1742 /* FIXME: Fall back to recursive copying */
1743
1744 default:
1745 break;
1746 }
1747
1748 ERROR ((0, e, _("Cannot rename %s to %s"),
1749 quote_n (0, src),
1750 quote_n (1, dst)));
1751 return false;
1752 }
1753 return true;
1754 }
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