]> Dogcows Code - chaz/tar/blob - src/extract.c
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[chaz/tar] / src / extract.c
1 /* Extract files from a tar archive.
2
3 Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000,
4 2001, 2003, 2004 Free Software Foundation, Inc.
5
6 Written by John Gilmore, on 1985-11-19.
7
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 2, or (at your option) any later
11 version.
12
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.
17
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 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21
22 #include "system.h"
23 #include <quotearg.h>
24 #include <errno.h>
25
26 #if HAVE_UTIME_H
27 # include <utime.h>
28 #else
29 struct utimbuf
30 {
31 long actime;
32 long modtime;
33 };
34 #endif
35
36 #include "common.h"
37
38 bool we_are_root; /* true if our effective uid == 0 */
39 static mode_t newdir_umask; /* umask when creating new directories */
40 static mode_t current_umask; /* current umask (which is set to 0 if -p) */
41
42 /* Status of the permissions of a file that we are extracting. */
43 enum permstatus
44 {
45 /* This file may have existed already; its permissions are unknown. */
46 UNKNOWN_PERMSTATUS,
47
48 /* This file was created using the permissions from the archive. */
49 ARCHIVED_PERMSTATUS,
50
51 /* This is an intermediate directory; the archive did not specify
52 its permissions. */
53 INTERDIR_PERMSTATUS
54 };
55
56 /* List of directories whose statuses we need to extract after we've
57 finished extracting their subsidiary files. If you consider each
58 contiguous subsequence of elements of the form [D]?[^D]*, where [D]
59 represents an element where AFTER_SYMLINKS is nonzero and [^D]
60 represents an element where AFTER_SYMLINKS is zero, then the head
61 of the subsequence has the longest name, and each non-head element
62 in the prefix is an ancestor (in the directory hierarchy) of the
63 preceding element. */
64
65 struct delayed_set_stat
66 {
67 struct delayed_set_stat *next;
68 struct stat stat_info;
69 size_t file_name_len;
70 mode_t invert_permissions;
71 enum permstatus permstatus;
72 bool after_symlinks;
73 char file_name[1];
74 };
75
76 static struct delayed_set_stat *delayed_set_stat_head;
77
78 /* List of symbolic links whose creation we have delayed. */
79 struct delayed_symlink
80 {
81 /* The next delayed symbolic link in the list. */
82 struct delayed_symlink *next;
83
84 /* The device, inode number and last-modified time of the placeholder. */
85 dev_t dev;
86 ino_t ino;
87 time_t mtime;
88
89 /* The desired owner and group of the symbolic link. */
90 uid_t uid;
91 gid_t gid;
92
93 /* A list of sources for this symlink. The sources are all to be
94 hard-linked together. */
95 struct string_list *sources;
96
97 /* The desired target of the desired link. */
98 char target[1];
99 };
100
101 static struct delayed_symlink *delayed_symlink_head;
102
103 struct string_list
104 {
105 struct string_list *next;
106 char string[1];
107 };
108
109 /* Set up to extract files. */
110 void
111 extr_init (void)
112 {
113 we_are_root = geteuid () == 0;
114 same_permissions_option += we_are_root;
115 same_owner_option += we_are_root;
116 xalloc_fail_func = extract_finish;
117
118 /* Save 'root device' to avoid purging mount points.
119 FIXME: Should the same be done after handling -C option ? */
120 if (one_file_system_option)
121 {
122 struct stat st;
123 char *dir = xgetcwd ();
124
125 if (deref_stat (true, dir, &st))
126 stat_diag (dir);
127 else
128 root_device = st.st_dev;
129 }
130
131 /* Option -p clears the kernel umask, so it does not affect proper
132 restoration of file permissions. New intermediate directories will
133 comply with umask at start of program. */
134
135 newdir_umask = umask (0);
136 if (0 < same_permissions_option)
137 current_umask = 0;
138 else
139 {
140 umask (newdir_umask); /* restore the kernel umask */
141 current_umask = newdir_umask;
142 }
143 }
144
145 /* If restoring permissions, restore the mode for FILE_NAME from
146 information given in *STAT_INFO (where *CUR_INFO gives
147 the current status if CUR_INFO is nonzero); otherwise invert the
148 INVERT_PERMISSIONS bits from the file's current permissions.
149 PERMSTATUS specifies the status of the file's permissions.
150 TYPEFLAG specifies the type of the file. */
151 static void
152 set_mode (char const *file_name,
153 struct stat const *stat_info,
154 struct stat const *cur_info,
155 mode_t invert_permissions, enum permstatus permstatus,
156 char typeflag)
157 {
158 mode_t mode;
159
160 if (0 < same_permissions_option
161 && permstatus != INTERDIR_PERMSTATUS)
162 {
163 mode = stat_info->st_mode;
164
165 /* If we created the file and it has a usual mode, then its mode
166 is normally set correctly already. But on many hosts, some
167 directories inherit the setgid bits from their parents, so we
168 we must set directories' modes explicitly. */
169 if (permstatus == ARCHIVED_PERMSTATUS
170 && ! (mode & ~ MODE_RWX)
171 && typeflag != DIRTYPE
172 && typeflag != GNUTYPE_DUMPDIR)
173 return;
174 }
175 else if (! invert_permissions)
176 return;
177 else
178 {
179 /* We must inspect a directory's current permissions, since the
180 directory may have inherited its setgid bit from its parent.
181
182 INVERT_PERMISSIONS happens to be nonzero only for directories
183 that we created, so there's no point optimizing this code for
184 other cases. */
185 struct stat st;
186 if (! cur_info)
187 {
188 if (stat (file_name, &st) != 0)
189 {
190 stat_error (file_name);
191 return;
192 }
193 cur_info = &st;
194 }
195 mode = cur_info->st_mode ^ invert_permissions;
196 }
197
198 if (chmod (file_name, mode) != 0)
199 chmod_error_details (file_name, mode);
200 }
201
202 /* Check time after successfully setting FILE_NAME's time stamp to T. */
203 static void
204 check_time (char const *file_name, time_t t)
205 {
206 time_t now;
207 if (t <= 0)
208 WARN ((0, 0, _("%s: implausibly old time stamp %s"),
209 file_name, tartime (t)));
210 else if (start_time < t && (now = time (0)) < t)
211 WARN ((0, 0, _("%s: time stamp %s is %lu s in the future"),
212 file_name, tartime (t), (unsigned long) (t - now)));
213 }
214
215 /* Restore stat attributes (owner, group, mode and times) for
216 FILE_NAME, using information given in *STAT_INFO.
217 If CUR_INFO is nonzero, *CUR_INFO is the
218 file's currernt status.
219 If not restoring permissions, invert the
220 INVERT_PERMISSIONS bits from the file's current permissions.
221 PERMSTATUS specifies the status of the file's permissions.
222 TYPEFLAG specifies the type of the file. */
223
224 /* FIXME: About proper restoration of symbolic link attributes, we still do
225 not have it right. Pretesters' reports tell us we need further study and
226 probably more configuration. For now, just use lchown if it exists, and
227 punt for the rest. Sigh! */
228
229 static void
230 set_stat (char const *file_name,
231 struct stat const *stat_info,
232 struct stat const *cur_info,
233 mode_t invert_permissions, enum permstatus permstatus,
234 char typeflag)
235 {
236 struct utimbuf utimbuf;
237
238 if (typeflag != SYMTYPE)
239 {
240 /* We do the utime before the chmod because some versions of utime are
241 broken and trash the modes of the file. */
242
243 if (! touch_option && permstatus != INTERDIR_PERMSTATUS)
244 {
245 /* We set the accessed time to `now', which is really the time we
246 started extracting files, unless incremental_option is used, in
247 which case .st_atime is used. */
248
249 /* FIXME: incremental_option should set ctime too, but how? */
250
251 if (incremental_option)
252 utimbuf.actime = stat_info->st_atime;
253 else
254 utimbuf.actime = start_time;
255
256 utimbuf.modtime = stat_info->st_mtime;
257
258 if (utime (file_name, &utimbuf) < 0)
259 utime_error (file_name);
260 else
261 {
262 check_time (file_name, utimbuf.actime);
263 check_time (file_name, utimbuf.modtime);
264 }
265 }
266
267 /* Some systems allow non-root users to give files away. Once this
268 done, it is not possible anymore to change file permissions, so we
269 have to set permissions prior to possibly giving files away. */
270
271 set_mode (file_name, stat_info, cur_info,
272 invert_permissions, permstatus, typeflag);
273 }
274
275 if (0 < same_owner_option && permstatus != INTERDIR_PERMSTATUS)
276 {
277 /* When lchown exists, it should be used to change the attributes of
278 the symbolic link itself. In this case, a mere chown would change
279 the attributes of the file the symbolic link is pointing to, and
280 should be avoided. */
281
282 if (typeflag == SYMTYPE)
283 {
284 #if HAVE_LCHOWN
285 if (lchown (file_name, stat_info->st_uid, stat_info->st_gid) < 0)
286 chown_error_details (file_name,
287 stat_info->st_uid, stat_info->st_gid);
288 #endif
289 }
290 else
291 {
292 if (chown (file_name, stat_info->st_uid, stat_info->st_gid) < 0)
293 chown_error_details (file_name,
294 stat_info->st_uid, stat_info->st_gid);
295
296 /* On a few systems, and in particular, those allowing to give files
297 away, changing the owner or group destroys the suid or sgid bits.
298 So let's attempt setting these bits once more. */
299 if (stat_info->st_mode & (S_ISUID | S_ISGID | S_ISVTX))
300 set_mode (file_name, stat_info, 0,
301 invert_permissions, permstatus, typeflag);
302 }
303 }
304 }
305
306 /* Remember to restore stat attributes (owner, group, mode and times)
307 for the directory FILE_NAME, using information given in *STAT_INFO,
308 once we stop extracting files into that directory.
309 If not restoring permissions, remember to invert the
310 INVERT_PERMISSIONS bits from the file's current permissions.
311 PERMSTATUS specifies the status of the file's permissions. */
312 static void
313 delay_set_stat (char const *file_name, struct stat const *stat_info,
314 mode_t invert_permissions, enum permstatus permstatus)
315 {
316 size_t file_name_len = strlen (file_name);
317 struct delayed_set_stat *data =
318 xmalloc (offsetof (struct delayed_set_stat, file_name)
319 + file_name_len + 1);
320 data->file_name_len = file_name_len;
321 strcpy (data->file_name, file_name);
322 data->invert_permissions = invert_permissions;
323 data->permstatus = permstatus;
324 data->after_symlinks = 0;
325 data->stat_info = *stat_info;
326 data->next = delayed_set_stat_head;
327 delayed_set_stat_head = data;
328 }
329
330 /* Update the delayed_set_stat info for an intermediate directory
331 created within the file name of DIR. The intermediate directory turned
332 out to be the same as this directory, e.g. due to ".." or symbolic
333 links. *DIR_STAT_INFO is the status of the directory. */
334 static void
335 repair_delayed_set_stat (char const *dir,
336 struct stat const *dir_stat_info)
337 {
338 struct delayed_set_stat *data;
339 for (data = delayed_set_stat_head; data; data = data->next)
340 {
341 struct stat st;
342 if (stat (data->file_name, &st) != 0)
343 {
344 stat_error (data->file_name);
345 return;
346 }
347
348 if (st.st_dev == dir_stat_info->st_dev
349 && st.st_ino == dir_stat_info->st_ino)
350 {
351 data->stat_info = current_stat_info.stat;
352 data->invert_permissions =
353 (MODE_RWX & (current_stat_info.stat.st_mode ^ st.st_mode));
354 data->permstatus = ARCHIVED_PERMSTATUS;
355 return;
356 }
357 }
358
359 ERROR ((0, 0, _("%s: Unexpected inconsistency when making directory"),
360 quotearg_colon (dir)));
361 }
362
363 /* After a file/link/symlink/directory creation has failed, see if
364 it's because some required directory was not present, and if so,
365 create all required directories. Return non-zero if a directory
366 was created. */
367 static int
368 make_directories (char *file_name)
369 {
370 char *cursor0 = file_name + FILESYSTEM_PREFIX_LEN (file_name);
371 char *cursor; /* points into the file name */
372 int did_something = 0; /* did we do anything yet? */
373 int mode;
374 int invert_permissions;
375 int status;
376
377
378 for (cursor = cursor0; *cursor; cursor++)
379 {
380 if (! ISSLASH (*cursor))
381 continue;
382
383 /* Avoid mkdir of empty string, if leading or double '/'. */
384
385 if (cursor == cursor0 || ISSLASH (cursor[-1]))
386 continue;
387
388 /* Avoid mkdir where last part of file name is "." or "..". */
389
390 if (cursor[-1] == '.'
391 && (cursor == cursor0 + 1 || ISSLASH (cursor[-2])
392 || (cursor[-2] == '.'
393 && (cursor == cursor0 + 2 || ISSLASH (cursor[-3])))))
394 continue;
395
396 *cursor = '\0'; /* truncate the name there */
397 mode = MODE_RWX & ~ newdir_umask;
398 invert_permissions = we_are_root ? 0 : MODE_WXUSR & ~ mode;
399 status = mkdir (file_name, mode ^ invert_permissions);
400
401 if (status == 0)
402 {
403 /* Create a struct delayed_set_stat even if
404 invert_permissions is zero, because
405 repair_delayed_set_stat may need to update the struct. */
406 delay_set_stat (file_name,
407 &current_stat_info.stat /* ignored */,
408 invert_permissions, INTERDIR_PERMSTATUS);
409
410 print_for_mkdir (file_name, cursor - file_name, mode);
411 did_something = 1;
412
413 *cursor = '/';
414 continue;
415 }
416
417 *cursor = '/';
418
419 if (errno == EEXIST)
420 continue; /* Directory already exists. */
421 else if ((errno == ENOSYS /* Automounted dirs on Solaris return
422 this. Reported by Warren Hyde
423 <Warren.Hyde@motorola.com> */
424 || ERRNO_IS_EACCES) /* Turbo C mkdir gives a funny errno. */
425 && access (file_name, W_OK) == 0)
426 continue;
427
428 /* Some other error in the mkdir. We return to the caller. */
429 break;
430 }
431
432 return did_something; /* tell them to retry if we made one */
433 }
434
435 static bool
436 file_newer_p (const char *file_name, struct tar_stat_info *tar_stat)
437 {
438 struct stat st;
439
440 if (stat (file_name, &st))
441 {
442 stat_warn (file_name);
443 return true; /* Be on the safe side */
444 }
445 if (!S_ISDIR (st.st_mode)
446 && st.st_mtime >= tar_stat->stat.st_mtime)
447 {
448 return true;
449 }
450 return false;
451 }
452
453 /* Prepare to extract a file.
454 Return zero if extraction should not proceed. */
455
456 static int
457 prepare_to_extract (char const *file_name)
458 {
459 if (to_stdout_option)
460 return 0;
461
462 switch (old_files_option)
463 {
464 case UNLINK_FIRST_OLD_FILES:
465 if (!remove_any_file (file_name, recursive_unlink_option)
466 && errno && errno != ENOENT)
467 {
468 unlink_error (file_name);
469 return 0;
470 }
471 break;
472
473 case KEEP_NEWER_FILES:
474 if (file_newer_p (file_name, &current_stat_info))
475 {
476 WARN ((0, 0, _("Current `%s' is newer"), file_name));
477 return 0;
478 }
479 break;
480
481 default:
482 break;
483 }
484
485 return 1;
486 }
487
488 /* Attempt repairing what went wrong with the extraction. Delete an
489 already existing file or create missing intermediate directories.
490 Return nonzero if we somewhat increased our chances at a successful
491 extraction. errno is properly restored on zero return. */
492 static int
493 maybe_recoverable (char *file_name, int *interdir_made)
494 {
495 int e = errno;
496
497 if (*interdir_made)
498 return 0;
499
500 switch (errno)
501 {
502 case EEXIST:
503 /* Remove an old file, if the options allow this. */
504
505 switch (old_files_option)
506 {
507 case KEEP_OLD_FILES:
508 return 0;
509
510 case KEEP_NEWER_FILES:
511 if (file_newer_p (file_name, &current_stat_info))
512 {
513 errno = e;
514 return 0;
515 }
516 /* FALL THROUGH */
517
518 case DEFAULT_OLD_FILES:
519 case NO_OVERWRITE_DIR_OLD_FILES:
520 case OVERWRITE_OLD_FILES:
521 {
522 int r = remove_any_file (file_name, 0);
523 errno = EEXIST;
524 return r;
525 }
526
527 case UNLINK_FIRST_OLD_FILES:
528 break;
529 }
530
531 case ENOENT:
532 /* Attempt creating missing intermediate directories. */
533 if (! make_directories (file_name))
534 {
535 errno = ENOENT;
536 return 0;
537 }
538 *interdir_made = 1;
539 return 1;
540
541 default:
542 /* Just say we can't do anything about it... */
543
544 return 0;
545 }
546 }
547
548 /* Fix the statuses of all directories whose statuses need fixing, and
549 which are not ancestors of FILE_NAME. If AFTER_SYMLINKS is
550 nonzero, do this for all such directories; otherwise, stop at the
551 first directory that is marked to be fixed up only after delayed
552 symlinks are applied. */
553 static void
554 apply_nonancestor_delayed_set_stat (char const *file_name, bool after_symlinks)
555 {
556 size_t file_name_len = strlen (file_name);
557 bool check_for_renamed_directories = 0;
558
559 while (delayed_set_stat_head)
560 {
561 struct delayed_set_stat *data = delayed_set_stat_head;
562 bool skip_this_one = 0;
563 struct stat st;
564 struct stat const *cur_info = 0;
565
566 check_for_renamed_directories |= data->after_symlinks;
567
568 if (after_symlinks < data->after_symlinks
569 || (data->file_name_len < file_name_len
570 && file_name[data->file_name_len]
571 && (ISSLASH (file_name[data->file_name_len])
572 || ISSLASH (file_name[data->file_name_len - 1]))
573 && memcmp (file_name, data->file_name, data->file_name_len) == 0))
574 break;
575
576 if (check_for_renamed_directories)
577 {
578 cur_info = &st;
579 if (stat (data->file_name, &st) != 0)
580 {
581 stat_error (data->file_name);
582 skip_this_one = 1;
583 }
584 else if (! (st.st_dev == data->stat_info.st_dev
585 && (st.st_ino == data->stat_info.st_ino)))
586 {
587 ERROR ((0, 0,
588 _("%s: Directory renamed before its status could be extracted"),
589 quotearg_colon (data->file_name)));
590 skip_this_one = 1;
591 }
592 }
593
594 if (! skip_this_one)
595 set_stat (data->file_name, &data->stat_info, cur_info,
596 data->invert_permissions, data->permstatus, DIRTYPE);
597
598 delayed_set_stat_head = data->next;
599 free (data);
600 }
601 }
602
603 /* Extract a file from the archive. */
604 void
605 extract_archive (void)
606 {
607 union block *data_block;
608 int fd;
609 int status;
610 size_t count;
611 size_t written;
612 int openflag;
613 mode_t mode;
614 off_t size;
615 int interdir_made = 0;
616 char typeflag;
617 char *file_name;
618
619 set_next_block_after (current_header);
620 decode_header (current_header, &current_stat_info, &current_format, 1);
621
622 if (interactive_option && !confirm ("extract", current_stat_info.file_name))
623 {
624 skip_member ();
625 return;
626 }
627
628 /* Print the block from current_header and current_stat. */
629
630 if (verbose_option)
631 print_header (&current_stat_info, -1);
632
633 file_name = safer_name_suffix (current_stat_info.file_name, false);
634 if (strip_name_components)
635 {
636 size_t prefix_len = stripped_prefix_len (file_name, strip_name_components);
637 if (prefix_len == (size_t) -1)
638 {
639 skip_member ();
640 return;
641 }
642 file_name += prefix_len;
643 }
644
645 apply_nonancestor_delayed_set_stat (file_name, 0);
646
647 /* Take a safety backup of a previously existing file. */
648
649 if (backup_option && !to_stdout_option)
650 if (!maybe_backup_file (file_name, 0))
651 {
652 int e = errno;
653 ERROR ((0, e, _("%s: Was unable to backup this file"),
654 quotearg_colon (file_name)));
655 skip_member ();
656 return;
657 }
658
659 /* Extract the archive entry according to its type. */
660
661 /* KLUDGE */
662 typeflag = sparse_member_p (&current_stat_info) ?
663 GNUTYPE_SPARSE : current_header->header.typeflag;
664
665 switch (typeflag)
666 {
667 case GNUTYPE_SPARSE:
668 /* Fall through. */
669
670 case AREGTYPE:
671 case REGTYPE:
672 case CONTTYPE:
673
674 /* Appears to be a file. But BSD tar uses the convention that a slash
675 suffix means a directory. */
676
677 if (current_stat_info.had_trailing_slash)
678 goto really_dir;
679
680 /* FIXME: deal with protection issues. */
681
682 again_file:
683 openflag = (O_WRONLY | O_BINARY | O_CREAT
684 | (old_files_option == OVERWRITE_OLD_FILES
685 ? O_TRUNC
686 : O_EXCL));
687 mode = current_stat_info.stat.st_mode & MODE_RWX & ~ current_umask;
688
689 if (to_stdout_option)
690 {
691 fd = STDOUT_FILENO;
692 goto extract_file;
693 }
694
695 if (! prepare_to_extract (file_name))
696 {
697 skip_member ();
698 if (backup_option)
699 undo_last_backup ();
700 break;
701 }
702
703 #if O_CTG
704 /* Contiguous files (on the Masscomp) have to specify the size in
705 the open call that creates them. */
706
707 if (typeflag == CONTTYPE)
708 fd = open (file_name, openflag | O_CTG, mode, current_stat_info.stat.st_size);
709 else
710 fd = open (file_name, openflag, mode);
711
712 #else /* not O_CTG */
713 if (typeflag == CONTTYPE)
714 {
715 static int conttype_diagnosed;
716
717 if (!conttype_diagnosed)
718 {
719 conttype_diagnosed = 1;
720 WARN ((0, 0, _("Extracting contiguous files as regular files")));
721 }
722 }
723 fd = open (file_name, openflag, mode);
724
725 #endif /* not O_CTG */
726
727 if (fd < 0)
728 {
729 if (maybe_recoverable (file_name, &interdir_made))
730 goto again_file;
731
732 open_error (file_name);
733 skip_member ();
734 if (backup_option)
735 undo_last_backup ();
736 break;
737 }
738
739 extract_file:
740 if (current_stat_info.is_sparse)
741 {
742 sparse_extract_file (fd, &current_stat_info, &size);
743 }
744 else
745 for (size = current_stat_info.stat.st_size; size > 0; )
746 {
747 if (multi_volume_option)
748 {
749 assign_string (&save_name, current_stat_info.file_name);
750 save_totsize = current_stat_info.stat.st_size;
751 save_sizeleft = size;
752 }
753
754 /* Locate data, determine max length writeable, write it,
755 block that we have used the data, then check if the write
756 worked. */
757
758 data_block = find_next_block ();
759 if (! data_block)
760 {
761 ERROR ((0, 0, _("Unexpected EOF in archive")));
762 break; /* FIXME: What happens, then? */
763 }
764
765 written = available_space_after (data_block);
766
767 if (written > size)
768 written = size;
769 errno = 0;
770 count = full_write (fd, data_block->buffer, written);
771 size -= count;
772
773 set_next_block_after ((union block *)
774 (data_block->buffer + written - 1));
775 if (count != written)
776 {
777 write_error_details (file_name, count, written);
778 break;
779 }
780 }
781
782 skip_file (size);
783
784 if (multi_volume_option)
785 assign_string (&save_name, 0);
786
787 /* If writing to stdout, don't try to do anything to the filename;
788 it doesn't exist, or we don't want to touch it anyway. */
789
790 if (to_stdout_option)
791 break;
792
793 status = close (fd);
794 if (status < 0)
795 {
796 close_error (file_name);
797 if (backup_option)
798 undo_last_backup ();
799 }
800
801 set_stat (file_name, &current_stat_info.stat, 0, 0,
802 (old_files_option == OVERWRITE_OLD_FILES
803 ? UNKNOWN_PERMSTATUS
804 : ARCHIVED_PERMSTATUS),
805 typeflag);
806 break;
807
808 case SYMTYPE:
809 #ifdef HAVE_SYMLINK
810 if (! prepare_to_extract (file_name))
811 break;
812
813 if (absolute_names_option
814 || ! (ISSLASH (current_stat_info.link_name
815 [FILESYSTEM_PREFIX_LEN (current_stat_info.link_name)])
816 || contains_dot_dot (current_stat_info.link_name)))
817 {
818 while (status = symlink (current_stat_info.link_name, file_name),
819 status != 0)
820 if (!maybe_recoverable (file_name, &interdir_made))
821 break;
822
823 if (status == 0)
824 set_stat (file_name, &current_stat_info.stat, 0, 0, 0, SYMTYPE);
825 else
826 symlink_error (current_stat_info.link_name, file_name);
827 }
828 else
829 {
830 /* This symbolic link is potentially dangerous. Don't
831 create it now; instead, create a placeholder file, which
832 will be replaced after other extraction is done. */
833 struct stat st;
834
835 while (fd = open (file_name, O_WRONLY | O_CREAT | O_EXCL, 0),
836 fd < 0)
837 if (! maybe_recoverable (file_name, &interdir_made))
838 break;
839
840 status = -1;
841 if (fd < 0)
842 open_error (file_name);
843 else if (fstat (fd, &st) != 0)
844 {
845 stat_error (file_name);
846 close (fd);
847 }
848 else if (close (fd) != 0)
849 close_error (file_name);
850 else
851 {
852 struct delayed_set_stat *h;
853 struct delayed_symlink *p =
854 xmalloc (offsetof (struct delayed_symlink, target)
855 + strlen (current_stat_info.link_name) + 1);
856 p->next = delayed_symlink_head;
857 delayed_symlink_head = p;
858 p->dev = st.st_dev;
859 p->ino = st.st_ino;
860 p->mtime = st.st_mtime;
861 p->uid = current_stat_info.stat.st_uid;
862 p->gid = current_stat_info.stat.st_gid;
863 p->sources = xmalloc (offsetof (struct string_list, string)
864 + strlen (file_name) + 1);
865 p->sources->next = 0;
866 strcpy (p->sources->string, file_name);
867 strcpy (p->target, current_stat_info.link_name);
868
869 h = delayed_set_stat_head;
870 if (h && ! h->after_symlinks
871 && strncmp (file_name, h->file_name, h->file_name_len) == 0
872 && ISSLASH (file_name[h->file_name_len])
873 && (base_name (file_name)
874 == file_name + h->file_name_len + 1))
875 {
876 do
877 {
878 h->after_symlinks = 1;
879
880 if (stat (h->file_name, &st) != 0)
881 stat_error (h->file_name);
882 else
883 {
884 h->stat_info.st_dev = st.st_dev;
885 h->stat_info.st_ino = st.st_ino;
886 }
887 }
888 while ((h = h->next) && ! h->after_symlinks);
889 }
890
891 status = 0;
892 }
893 }
894
895 if (status != 0 && backup_option)
896 undo_last_backup ();
897 break;
898
899 #else
900 {
901 static int warned_once;
902
903 if (!warned_once)
904 {
905 warned_once = 1;
906 WARN ((0, 0,
907 _("Attempting extraction of symbolic links as hard links")));
908 }
909 }
910 typeflag = LNKTYPE;
911 /* Fall through. */
912 #endif
913
914 case LNKTYPE:
915 if (! prepare_to_extract (file_name))
916 break;
917
918 again_link:
919 {
920 char const *link_name = safer_name_suffix (current_stat_info.link_name,
921 true);
922 struct stat st1, st2;
923 int e;
924
925 /* MSDOS does not implement links. However, djgpp's link() actually
926 copies the file. */
927 status = link (link_name, file_name);
928 e = errno;
929
930 if (status == 0)
931 {
932 struct delayed_symlink *ds = delayed_symlink_head;
933 if (ds && lstat (link_name, &st1) == 0)
934 for (; ds; ds = ds->next)
935 if (ds->dev == st1.st_dev
936 && ds->ino == st1.st_ino
937 && ds->mtime == st1.st_mtime)
938 {
939 struct string_list *p =
940 xmalloc (offsetof (struct string_list, string)
941 + strlen (file_name) + 1);
942 strcpy (p->string, file_name);
943 p->next = ds->sources;
944 ds->sources = p;
945 break;
946 }
947 break;
948 }
949
950 if ((e == EEXIST && strcmp (link_name, file_name) == 0)
951 || (lstat (link_name, &st1) == 0
952 && lstat (file_name, &st2) == 0
953 && st1.st_dev == st2.st_dev
954 && st1.st_ino == st2.st_ino))
955 break;
956
957 errno = e;
958 if (maybe_recoverable (file_name, &interdir_made))
959 goto again_link;
960
961 if (incremental_option && errno == EEXIST)
962 break;
963
964 link_error (link_name, file_name);
965 if (backup_option)
966 undo_last_backup ();
967 }
968 break;
969
970 #if S_IFCHR
971 case CHRTYPE:
972 current_stat_info.stat.st_mode |= S_IFCHR;
973 goto make_node;
974 #endif
975
976 #if S_IFBLK
977 case BLKTYPE:
978 current_stat_info.stat.st_mode |= S_IFBLK;
979 #endif
980
981 #if S_IFCHR || S_IFBLK
982 make_node:
983 if (! prepare_to_extract (file_name))
984 break;
985
986 status = mknod (file_name, current_stat_info.stat.st_mode,
987 current_stat_info.stat.st_rdev);
988 if (status != 0)
989 {
990 if (maybe_recoverable (file_name, &interdir_made))
991 goto make_node;
992 mknod_error (file_name);
993 if (backup_option)
994 undo_last_backup ();
995 break;
996 };
997 set_stat (file_name, &current_stat_info.stat, 0, 0,
998 ARCHIVED_PERMSTATUS, typeflag);
999 break;
1000 #endif
1001
1002 #if HAVE_MKFIFO || defined mkfifo
1003 case FIFOTYPE:
1004 if (! prepare_to_extract (file_name))
1005 break;
1006
1007 while (status = mkfifo (file_name, current_stat_info.stat.st_mode),
1008 status != 0)
1009 if (!maybe_recoverable (file_name, &interdir_made))
1010 break;
1011
1012 if (status == 0)
1013 set_stat (file_name, &current_stat_info.stat, NULL, 0,
1014 ARCHIVED_PERMSTATUS, typeflag);
1015 else
1016 {
1017 mkfifo_error (file_name);
1018 if (backup_option)
1019 undo_last_backup ();
1020 }
1021 break;
1022 #endif
1023
1024 case DIRTYPE:
1025 case GNUTYPE_DUMPDIR:
1026 really_dir:
1027 if (incremental_option)
1028 {
1029 /* Read the entry and delete files that aren't listed in the
1030 archive. */
1031
1032 purge_directory (file_name);
1033 }
1034 else if (typeflag == GNUTYPE_DUMPDIR)
1035 skip_member ();
1036
1037 mode = ((current_stat_info.stat.st_mode
1038 | (we_are_root ? 0 : MODE_WXUSR))
1039 & MODE_RWX);
1040
1041 status = prepare_to_extract (file_name);
1042 if (status == 0)
1043 break;
1044 if (status < 0)
1045 goto directory_exists;
1046
1047 again_dir:
1048 status = mkdir (file_name, mode);
1049
1050 if (status != 0)
1051 {
1052 if (errno == EEXIST
1053 && (interdir_made
1054 || old_files_option == DEFAULT_OLD_FILES
1055 || old_files_option == OVERWRITE_OLD_FILES))
1056 {
1057 struct stat st;
1058 if (stat (file_name, &st) == 0)
1059 {
1060 if (interdir_made)
1061 {
1062 repair_delayed_set_stat (file_name, &st);
1063 break;
1064 }
1065 if (S_ISDIR (st.st_mode))
1066 {
1067 mode = st.st_mode & ~ current_umask;
1068 goto directory_exists;
1069 }
1070 }
1071 errno = EEXIST;
1072 }
1073
1074 if (maybe_recoverable (file_name, &interdir_made))
1075 goto again_dir;
1076
1077 if (errno != EEXIST)
1078 {
1079 mkdir_error (file_name);
1080 if (backup_option)
1081 undo_last_backup ();
1082 break;
1083 }
1084 }
1085
1086 directory_exists:
1087 if (status == 0
1088 || old_files_option == DEFAULT_OLD_FILES
1089 || old_files_option == OVERWRITE_OLD_FILES)
1090 delay_set_stat (file_name, &current_stat_info.stat,
1091 MODE_RWX & (mode ^ current_stat_info.stat.st_mode),
1092 (status == 0
1093 ? ARCHIVED_PERMSTATUS
1094 : UNKNOWN_PERMSTATUS));
1095 break;
1096
1097 case GNUTYPE_VOLHDR:
1098 if (verbose_option)
1099 fprintf (stdlis, _("Reading %s\n"), quote (current_stat_info.file_name));
1100 break;
1101
1102 case GNUTYPE_NAMES:
1103 extract_mangle ();
1104 break;
1105
1106 case GNUTYPE_MULTIVOL:
1107 ERROR ((0, 0,
1108 _("%s: Cannot extract -- file is continued from another volume"),
1109 quotearg_colon (current_stat_info.file_name)));
1110 skip_member ();
1111 if (backup_option)
1112 undo_last_backup ();
1113 break;
1114
1115 case GNUTYPE_LONGNAME:
1116 case GNUTYPE_LONGLINK:
1117 ERROR ((0, 0, _("Visible long name error")));
1118 skip_member ();
1119 if (backup_option)
1120 undo_last_backup ();
1121 break;
1122
1123 default:
1124 WARN ((0, 0,
1125 _("%s: Unknown file type '%c', extracted as normal file"),
1126 quotearg_colon (file_name), typeflag));
1127 goto again_file;
1128 }
1129 }
1130
1131 /* Extract the symbolic links whose final extraction were delayed. */
1132 static void
1133 apply_delayed_symlinks (void)
1134 {
1135 struct delayed_symlink *ds;
1136
1137 for (ds = delayed_symlink_head; ds; )
1138 {
1139 struct string_list *sources = ds->sources;
1140 char const *valid_source = 0;
1141
1142 for (sources = ds->sources; sources; sources = sources->next)
1143 {
1144 char const *source = sources->string;
1145 struct stat st;
1146
1147 /* Make sure the placeholder file is still there. If not,
1148 don't create a symlink, as the placeholder was probably
1149 removed by a later extraction. */
1150 if (lstat (source, &st) == 0
1151 && st.st_dev == ds->dev
1152 && st.st_ino == ds->ino
1153 && st.st_mtime == ds->mtime)
1154 {
1155 /* Unlink the placeholder, then create a hard link if possible,
1156 a symbolic link otherwise. */
1157 if (unlink (source) != 0)
1158 unlink_error (source);
1159 else if (valid_source && link (valid_source, source) == 0)
1160 ;
1161 else if (symlink (ds->target, source) != 0)
1162 symlink_error (ds->target, source);
1163 else
1164 {
1165 valid_source = source;
1166 st.st_uid = ds->uid;
1167 st.st_gid = ds->gid;
1168 set_stat (source, &st, 0, 0, 0, SYMTYPE);
1169 }
1170 }
1171 }
1172
1173 for (sources = ds->sources; sources; )
1174 {
1175 struct string_list *next = sources->next;
1176 free (sources);
1177 sources = next;
1178 }
1179
1180 {
1181 struct delayed_symlink *next = ds->next;
1182 free (ds);
1183 ds = next;
1184 }
1185 }
1186
1187 delayed_symlink_head = 0;
1188 }
1189
1190 /* Finish the extraction of an archive. */
1191 void
1192 extract_finish (void)
1193 {
1194 /* First, fix the status of ordinary directories that need fixing. */
1195 apply_nonancestor_delayed_set_stat ("", 0);
1196
1197 /* Then, apply delayed symlinks, so that they don't affect delayed
1198 directory status-setting for ordinary directories. */
1199 apply_delayed_symlinks ();
1200
1201 /* Finally, fix the status of directories that are ancestors
1202 of delayed symlinks. */
1203 apply_nonancestor_delayed_set_stat ("", 1);
1204 }
1205
1206 void
1207 fatal_exit (void)
1208 {
1209 extract_finish ();
1210 error (TAREXIT_FAILURE, 0, _("Error is not recoverable: exiting now"));
1211 abort ();
1212 }
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