source: trunk/minix/commands/pax/ar_subs.c@ 11

Last change on this file since 11 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 30.7 KB
RevLine 
[9]1/*-
2 * Copyright (c) 1992 Keith Muller.
3 * Copyright (c) 1992, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Keith Muller of the University of California, San Diego.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)ar_subs.c 8.2 (Berkeley) 4/18/94";
37#endif
38#endif /* not lint */
39
40#include <sys/types.h>
41#include <sys/time.h>
42#include <sys/stat.h>
43#include <signal.h>
44#include <string.h>
45#include <time.h>
46#include <stdio.h>
47#include <fcntl.h>
48#include <errno.h>
49#include <unistd.h>
50#include <stdlib.h>
51#include "pax.h"
52#include "extern.h"
53
54static void wr_archive(ARCHD *, int is_app);
55static int get_arc(void);
56static int next_head(ARCHD *);
57extern sigset_t s_mask;
58
59/*
60 * Routines which control the overall operation modes of pax as specified by
61 * the user: list, append, read ...
62 */
63
64static char hdbuf[BLKMULT]; /* space for archive header on read */
65u_long flcnt; /* number of files processed */
66
67/*
68 * list()
69 * list the contents of an archive which match user supplied pattern(s)
70 * (no pattern matches all).
71 */
72
73void
74list(void)
75{
76 ARCHD *arcn;
77 int res;
78 ARCHD archd;
79 time_t now;
80
81 arcn = &archd;
82 /*
83 * figure out archive type; pass any format specific options to the
84 * archive option processing routine; call the format init routine. We
85 * also save current time for ls_list() so we do not make a system
86 * call for each file we need to print. If verbose (vflag) start up
87 * the name and group caches.
88 */
89 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
90 ((*frmt->st_rd)() < 0))
91 return;
92
93 if (vflag && ((uidtb_start() < 0) || (gidtb_start() < 0)))
94 return;
95
96 now = time(NULL);
97
98 /*
99 * step through the archive until the format says it is done
100 */
101 while (next_head(arcn) == 0) {
102 /*
103 * check for pattern, and user specified options match.
104 * When all patterns are matched we are done.
105 */
106 if ((res = pat_match(arcn)) < 0)
107 break;
108
109 if ((res == 0) && (sel_chk(arcn) == 0)) {
110 /*
111 * pattern resulted in a selected file
112 */
113 if (pat_sel(arcn) < 0)
114 break;
115
116 /*
117 * modify the name as requested by the user if name
118 * survives modification, do a listing of the file
119 */
120 if ((res = mod_name(arcn)) < 0)
121 break;
122 if (res == 0)
123 ls_list(arcn, now, stdout);
124 }
125
126 /*
127 * skip to next archive format header using values calculated
128 * by the format header read routine
129 */
130 if (rd_skip(arcn->skip + arcn->pad) == 1)
131 break;
132 }
133
134 /*
135 * all done, let format have a chance to cleanup, and make sure that
136 * the patterns supplied by the user were all matched
137 */
138 (void)(*frmt->end_rd)();
139 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
140 ar_close();
141 pat_chk();
142}
143
144/*
145 * extract()
146 * extract the member(s) of an archive as specified by user supplied
147 * pattern(s) (no patterns extracts all members)
148 */
149
150void
151extract(void)
152{
153 ARCHD *arcn;
154 int res;
155 off_t cnt;
156 ARCHD archd;
157 struct stat sb;
158 int fd;
159 time_t now;
160
161 arcn = &archd;
162 /*
163 * figure out archive type; pass any format specific options to the
164 * archive option processing routine; call the format init routine;
165 * start up the directory modification time and access mode database
166 */
167 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
168 ((*frmt->st_rd)() < 0) || (dir_start() < 0))
169 return;
170
171 /*
172 * When we are doing interactive rename, we store the mapping of names
173 * so we can fix up hard links files later in the archive.
174 */
175 if (iflag && (name_start() < 0))
176 return;
177
178 now = time(NULL);
179
180 /*
181 * step through each entry on the archive until the format read routine
182 * says it is done
183 */
184 while (next_head(arcn) == 0) {
185
186 /*
187 * check for pattern, and user specified options match. When
188 * all the patterns are matched we are done
189 */
190 if ((res = pat_match(arcn)) < 0)
191 break;
192
193 if ((res > 0) || (sel_chk(arcn) != 0)) {
194 /*
195 * file is not selected. skip past any file data and
196 * padding and go back for the next archive member
197 */
198 (void)rd_skip(arcn->skip + arcn->pad);
199 continue;
200 }
201
202 /*
203 * with -u or -D only extract when the archive member is newer
204 * than the file with the same name in the file system (nos
205 * test of being the same type is required).
206 * NOTE: this test is done BEFORE name modifications as
207 * specified by pax. this operation can be confusing to the
208 * user who might expect the test to be done on an existing
209 * file AFTER the name mod. In honesty the pax spec is probably
210 * flawed in this respect.
211 */
212 if ((uflag || Dflag) && ((lstat(arcn->name, &sb) == 0))) {
213 if (uflag && Dflag) {
214 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
215 (arcn->sb.st_ctime <= sb.st_ctime)) {
216 (void)rd_skip(arcn->skip + arcn->pad);
217 continue;
218 }
219 } else if (Dflag) {
220 if (arcn->sb.st_ctime <= sb.st_ctime) {
221 (void)rd_skip(arcn->skip + arcn->pad);
222 continue;
223 }
224 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
225 (void)rd_skip(arcn->skip + arcn->pad);
226 continue;
227 }
228 }
229
230 /*
231 * this archive member is now been selected. modify the name.
232 */
233 if ((pat_sel(arcn) < 0) || ((res = mod_name(arcn)) < 0))
234 break;
235 if (res > 0) {
236 /*
237 * a bad name mod, skip and purge name from link table
238 */
239 purg_lnk(arcn);
240 (void)rd_skip(arcn->skip + arcn->pad);
241 continue;
242 }
243
244 /*
245 * Non standard -Y and -Z flag. When the existing file is
246 * same age or newer skip
247 */
248 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
249 if (Yflag && Zflag) {
250 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
251 (arcn->sb.st_ctime <= sb.st_ctime)) {
252 (void)rd_skip(arcn->skip + arcn->pad);
253 continue;
254 }
255 } else if (Yflag) {
256 if (arcn->sb.st_ctime <= sb.st_ctime) {
257 (void)rd_skip(arcn->skip + arcn->pad);
258 continue;
259 }
260 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
261 (void)rd_skip(arcn->skip + arcn->pad);
262 continue;
263 }
264 }
265
266 if (vflag) {
267 if (vflag > 1)
268 ls_list(arcn, now, listf);
269 else {
270 (void)fputs(arcn->name, listf);
271 vfpart = 1;
272 }
273 }
274
275 /*
276 * if required, chdir around.
277 */
278 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
279 if (chdir(arcn->pat->chdname) != 0)
280 syswarn(1, errno, "Cannot chdir to %s",
281 arcn->pat->chdname);
282
283 /*
284 * all ok, extract this member based on type
285 */
286 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
287 /*
288 * process archive members that are not regular files.
289 * throw out padding and any data that might follow the
290 * header (as determined by the format).
291 */
292 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
293 res = lnk_creat(arcn);
294 else
295 res = node_creat(arcn);
296
297 (void)rd_skip(arcn->skip + arcn->pad);
298 if (res < 0)
299 purg_lnk(arcn);
300
301 if (vflag && vfpart) {
302 (void)putc('\n', listf);
303 vfpart = 0;
304 }
305 continue;
306 }
307 /*
308 * we have a file with data here. If we can not create it, skip
309 * over the data and purge the name from hard link table
310 */
311 if ((fd = file_creat(arcn)) < 0) {
312 (void)rd_skip(arcn->skip + arcn->pad);
313 purg_lnk(arcn);
314 continue;
315 }
316 /*
317 * extract the file from the archive and skip over padding and
318 * any unprocessed data
319 */
320 res = (*frmt->rd_data)(arcn, fd, &cnt);
321 file_close(arcn, fd);
322 if (vflag && vfpart) {
323 (void)putc('\n', listf);
324 vfpart = 0;
325 }
326 if (!res)
327 (void)rd_skip(cnt + arcn->pad);
328
329 /*
330 * if required, chdir around.
331 */
332 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
333 if (fchdir(cwdfd) != 0)
334 syswarn(1, errno,
335 "Can't fchdir to starting directory");
336 }
337
338 /*
339 * all done, restore directory modes and times as required; make sure
340 * all patterns supplied by the user were matched; block off signals
341 * to avoid chance for multiple entry into the cleanup code.
342 */
343 (void)(*frmt->end_rd)();
344 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
345 ar_close();
346 proc_dir();
347 pat_chk();
348}
349
350/*
351 * wr_archive()
352 * Write an archive. used in both creating a new archive and appends on
353 * previously written archive.
354 */
355
356static void
357wr_archive(ARCHD *arcn, int is_app)
358{
359 int res;
360 int hlk;
361 int wr_one;
362 off_t cnt;
363 int (*wrf)(ARCHD *);
364 int fd = -1;
365 time_t now;
366
367 /*
368 * if this format supports hard link storage, start up the database
369 * that detects them.
370 */
371 if (((hlk = frmt->hlk) == 1) && (lnk_start() < 0))
372 return;
373
374 /*
375 * start up the file traversal code and format specific write
376 */
377 if ((ftree_start() < 0) || ((*frmt->st_wr)() < 0))
378 return;
379 wrf = frmt->wr;
380
381 /*
382 * When we are doing interactive rename, we store the mapping of names
383 * so we can fix up hard links files later in the archive.
384 */
385 if (iflag && (name_start() < 0))
386 return;
387
388 /*
389 * if this not append, and there are no files, we do no write a trailer
390 */
391 wr_one = is_app;
392
393 now = time(NULL);
394
395 /*
396 * while there are files to archive, process them one at at time
397 */
398 while (next_file(arcn) == 0) {
399 /*
400 * check if this file meets user specified options match.
401 */
402 if (sel_chk(arcn) != 0) {
403 ftree_notsel();
404 continue;
405 }
406 fd = -1;
407 if (uflag) {
408 /*
409 * only archive if this file is newer than a file with
410 * the same name that is already stored on the archive
411 */
412 if ((res = chk_ftime(arcn)) < 0)
413 break;
414 if (res > 0)
415 continue;
416 }
417
418 /*
419 * this file is considered selected now. see if this is a hard
420 * link to a file already stored
421 */
422 ftree_sel(arcn);
423 if (hlk && (chk_lnk(arcn) < 0))
424 break;
425
426 if ((arcn->type == PAX_REG) || (arcn->type == PAX_HRG) ||
427 (arcn->type == PAX_CTG)) {
428 /*
429 * we will have to read this file. by opening it now we
430 * can avoid writing a header to the archive for a file
431 * we were later unable to read (we also purge it from
432 * the link table).
433 */
434 if ((fd = open(arcn->org_name, O_RDONLY, 0)) < 0) {
435 syswarn(1,errno, "Unable to open %s to read",
436 arcn->org_name);
437 purg_lnk(arcn);
438 continue;
439 }
440 }
441
442 /*
443 * Now modify the name as requested by the user
444 */
445 if ((res = mod_name(arcn)) < 0) {
446 /*
447 * name modification says to skip this file, close the
448 * file and purge link table entry
449 */
450 rdfile_close(arcn, &fd);
451 purg_lnk(arcn);
452 break;
453 }
454
455 if ((res > 0) || (docrc && (set_crc(arcn, fd) < 0))) {
456 /*
457 * unable to obtain the crc we need, close the file,
458 * purge link table entry
459 */
460 rdfile_close(arcn, &fd);
461 purg_lnk(arcn);
462 continue;
463 }
464
465 if (vflag) {
466 if (vflag > 1)
467 ls_list(arcn, now, listf);
468 else {
469 (void)fputs(arcn->name, listf);
470 vfpart = 1;
471 }
472 }
473 ++flcnt;
474
475 /*
476 * looks safe to store the file, have the format specific
477 * routine write routine store the file header on the archive
478 */
479 if ((res = (*wrf)(arcn)) < 0) {
480 rdfile_close(arcn, &fd);
481 break;
482 }
483 wr_one = 1;
484 if (res > 0) {
485 /*
486 * format write says no file data needs to be stored
487 * so we are done messing with this file
488 */
489 if (vflag && vfpart) {
490 (void)putc('\n', listf);
491 vfpart = 0;
492 }
493 rdfile_close(arcn, &fd);
494 continue;
495 }
496
497 /*
498 * Add file data to the archive, quit on write error. if we
499 * cannot write the entire file contents to the archive we
500 * must pad the archive to replace the missing file data
501 * (otherwise during an extract the file header for the file
502 * which FOLLOWS this one will not be where we expect it to
503 * be).
504 */
505 res = (*frmt->wr_data)(arcn, fd, &cnt);
506 rdfile_close(arcn, &fd);
507 if (vflag && vfpart) {
508 (void)putc('\n', listf);
509 vfpart = 0;
510 }
511 if (res < 0)
512 break;
513
514 /*
515 * pad as required, cnt is number of bytes not written
516 */
517 if (((cnt > 0) && (wr_skip(cnt) < 0)) ||
518 ((arcn->pad > 0) && (wr_skip(arcn->pad) < 0)))
519 break;
520 }
521
522 /*
523 * tell format to write trailer; pad to block boundary; reset directory
524 * mode/access times, and check if all patterns supplied by the user
525 * were matched. block off signals to avoid chance for multiple entry
526 * into the cleanup code
527 */
528 if (wr_one) {
529 (*frmt->end_wr)();
530 wr_fin();
531 }
532 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
533 ar_close();
534 if (tflag)
535 proc_dir();
536 ftree_chk();
537}
538
539/*
540 * append()
541 * Add file to previously written archive. Archive format specified by the
542 * user must agree with archive. The archive is read first to collect
543 * modification times (if -u) and locate the archive trailer. The archive
544 * is positioned in front of the record with the trailer and wr_archive()
545 * is called to add the new members.
546 * PAX IMPLEMENTATION DETAIL NOTE:
547 * -u is implemented by adding the new members to the end of the archive.
548 * Care is taken so that these do not end up as links to the older
549 * version of the same file already stored in the archive. It is expected
550 * when extraction occurs these newer versions will over-write the older
551 * ones stored "earlier" in the archive (this may be a bad assumption as
552 * it depends on the implementation of the program doing the extraction).
553 * It is really difficult to splice in members without either re-writing
554 * the entire archive (from the point were the old version was), or having
555 * assistance of the format specification in terms of a special update
556 * header that invalidates a previous archive record. The POSIX spec left
557 * the method used to implement -u unspecified. This pax is able to
558 * over write existing files that it creates.
559 */
560
561void
562append(void)
563{
564 ARCHD *arcn;
565 int res;
566 ARCHD archd;
567 FSUB *orgfrmt;
568 int udev;
569 off_t tlen;
570
571 arcn = &archd;
572 orgfrmt = frmt;
573
574 /*
575 * Do not allow an append operation if the actual archive is of a
576 * different format than the user specified format.
577 */
578 if (get_arc() < 0)
579 return;
580 if ((orgfrmt != NULL) && (orgfrmt != frmt)) {
581 paxwarn(1, "Cannot mix current archive format %s with %s",
582 frmt->name, orgfrmt->name);
583 return;
584 }
585
586 /*
587 * pass the format any options and start up format
588 */
589 if (((*frmt->options)() < 0) || ((*frmt->st_rd)() < 0))
590 return;
591
592 /*
593 * if we only are adding members that are newer, we need to save the
594 * mod times for all files we see.
595 */
596 if (uflag && (ftime_start() < 0))
597 return;
598
599 /*
600 * some archive formats encode hard links by recording the device and
601 * file serial number (inode) but copy the file anyway (multiple times)
602 * to the archive. When we append, we run the risk that newly added
603 * files may have the same device and inode numbers as those recorded
604 * on the archive but during a previous run. If this happens, when the
605 * archive is extracted we get INCORRECT hard links. We avoid this by
606 * remapping the device numbers so that newly added files will never
607 * use the same device number as one found on the archive. remapping
608 * allows new members to safely have links among themselves. remapping
609 * also avoids problems with file inode (serial number) truncations
610 * when the inode number is larger than storage space in the archive
611 * header. See the remap routines for more details.
612 */
613 if ((udev = frmt->udev) && (dev_start() < 0))
614 return;
615
616 /*
617 * reading the archive may take a long time. If verbose tell the user
618 */
619 if (vflag) {
620 (void)fprintf(listf,
621 "%s: Reading archive to position at the end...", argv0);
622 vfpart = 1;
623 }
624
625 /*
626 * step through the archive until the format says it is done
627 */
628 while (next_head(arcn) == 0) {
629 /*
630 * check if this file meets user specified options.
631 */
632 if (sel_chk(arcn) != 0) {
633 if (rd_skip(arcn->skip + arcn->pad) == 1)
634 break;
635 continue;
636 }
637
638 if (uflag) {
639 /*
640 * see if this is the newest version of this file has
641 * already been seen, if so skip.
642 */
643 if ((res = chk_ftime(arcn)) < 0)
644 break;
645 if (res > 0) {
646 if (rd_skip(arcn->skip + arcn->pad) == 1)
647 break;
648 continue;
649 }
650 }
651
652 /*
653 * Store this device number. Device numbers seen during the
654 * read phase of append will cause newly appended files with a
655 * device number seen in the old part of the archive to be
656 * remapped to an unused device number.
657 */
658 if ((udev && (add_dev(arcn) < 0)) ||
659 (rd_skip(arcn->skip + arcn->pad) == 1))
660 break;
661 }
662
663 /*
664 * done, finish up read and get the number of bytes to back up so we
665 * can add new members. The format might have used the hard link table,
666 * purge it.
667 */
668 tlen = (*frmt->end_rd)();
669 lnk_end();
670
671 /*
672 * try to position for write, if this fails quit. if any error occurs,
673 * we will refuse to write
674 */
675 if (appnd_start(tlen) < 0)
676 return;
677
678 /*
679 * tell the user we are done reading.
680 */
681 if (vflag && vfpart) {
682 (void)fputs("done.\n", listf);
683 vfpart = 0;
684 }
685
686 /*
687 * go to the writing phase to add the new members
688 */
689 wr_archive(arcn, 1);
690}
691
692/*
693 * archive()
694 * write a new archive
695 */
696
697void
698archive(void)
699{
700 ARCHD archd;
701
702 /*
703 * if we only are adding members that are newer, we need to save the
704 * mod times for all files; set up for writing; pass the format any
705 * options write the archive
706 */
707 if ((uflag && (ftime_start() < 0)) || (wr_start() < 0))
708 return;
709 if ((*frmt->options)() < 0)
710 return;
711
712 wr_archive(&archd, 0);
713}
714
715/*
716 * copy()
717 * copy files from one part of the file system to another. this does not
718 * use any archive storage. The EFFECT OF THE COPY IS THE SAME as if an
719 * archive was written and then extracted in the destination directory
720 * (except the files are forced to be under the destination directory).
721 */
722
723void
724copy(void)
725{
726 ARCHD *arcn;
727 int res;
728 int fddest;
729 char *dest_pt;
730 int dlen;
731 int drem;
732 int fdsrc = -1;
733 struct stat sb;
734 ARCHD archd;
735 char dirbuf[PAXPATHLEN+1];
736
737 arcn = &archd;
738 /*
739 * set up the destination dir path and make sure it is a directory. We
740 * make sure we have a trailing / on the destination
741 */
742 dlen = l_strncpy(dirbuf, dirptr, sizeof(dirbuf) - 1);
743 dest_pt = dirbuf + dlen;
744 if (*(dest_pt-1) != '/') {
745 *dest_pt++ = '/';
746 ++dlen;
747 }
748 *dest_pt = '\0';
749 drem = PAXPATHLEN - dlen;
750
751 if (stat(dirptr, &sb) < 0) {
752 syswarn(1, errno, "Cannot access destination directory %s",
753 dirptr);
754 return;
755 }
756 if (!S_ISDIR(sb.st_mode)) {
757 paxwarn(1, "Destination is not a directory %s", dirptr);
758 return;
759 }
760
761 /*
762 * start up the hard link table; file traversal routines and the
763 * modification time and access mode database
764 */
765 if ((lnk_start() < 0) || (ftree_start() < 0) || (dir_start() < 0))
766 return;
767
768 /*
769 * When we are doing interactive rename, we store the mapping of names
770 * so we can fix up hard links files later in the archive.
771 */
772 if (iflag && (name_start() < 0))
773 return;
774
775 /*
776 * set up to cp file trees
777 */
778 cp_start();
779
780 /*
781 * while there are files to archive, process them
782 */
783 while (next_file(arcn) == 0) {
784 fdsrc = -1;
785
786 /*
787 * check if this file meets user specified options
788 */
789 if (sel_chk(arcn) != 0) {
790 ftree_notsel();
791 continue;
792 }
793
794 /*
795 * if there is already a file in the destination directory with
796 * the same name and it is newer, skip the one stored on the
797 * archive.
798 * NOTE: this test is done BEFORE name modifications as
799 * specified by pax. this can be confusing to the user who
800 * might expect the test to be done on an existing file AFTER
801 * the name mod. In honesty the pax spec is probably flawed in
802 * this respect
803 */
804 if (uflag || Dflag) {
805 /*
806 * create the destination name
807 */
808 if (*(arcn->name) == '/')
809 res = 1;
810 else
811 res = 0;
812 if ((arcn->nlen - res) > drem) {
813 paxwarn(1, "Destination pathname too long %s",
814 arcn->name);
815 continue;
816 }
817 (void)strncpy(dest_pt, arcn->name + res, drem);
818 dirbuf[PAXPATHLEN] = '\0';
819
820 /*
821 * if existing file is same age or newer skip
822 */
823 res = lstat(dirbuf, &sb);
824 *dest_pt = '\0';
825
826 if (res == 0) {
827 if (uflag && Dflag) {
828 if ((arcn->sb.st_mtime<=sb.st_mtime) &&
829 (arcn->sb.st_ctime<=sb.st_ctime))
830 continue;
831 } else if (Dflag) {
832 if (arcn->sb.st_ctime <= sb.st_ctime)
833 continue;
834 } else if (arcn->sb.st_mtime <= sb.st_mtime)
835 continue;
836 }
837 }
838
839 /*
840 * this file is considered selected. See if this is a hard link
841 * to a previous file; modify the name as requested by the
842 * user; set the final destination.
843 */
844 ftree_sel(arcn);
845 if ((chk_lnk(arcn) < 0) || ((res = mod_name(arcn)) < 0))
846 break;
847 if ((res > 0) || (set_dest(arcn, dirbuf, dlen) < 0)) {
848 /*
849 * skip file, purge from link table
850 */
851 purg_lnk(arcn);
852 continue;
853 }
854
855 /*
856 * Non standard -Y and -Z flag. When the exisiting file is
857 * same age or newer skip
858 */
859 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
860 if (Yflag && Zflag) {
861 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
862 (arcn->sb.st_ctime <= sb.st_ctime))
863 continue;
864 } else if (Yflag) {
865 if (arcn->sb.st_ctime <= sb.st_ctime)
866 continue;
867 } else if (arcn->sb.st_mtime <= sb.st_mtime)
868 continue;
869 }
870
871 if (vflag) {
872 (void)fputs(arcn->name, listf);
873 vfpart = 1;
874 }
875 ++flcnt;
876
877 /*
878 * try to create a hard link to the src file if requested
879 * but make sure we are not trying to overwrite ourselves.
880 */
881 if (lflag)
882 res = cross_lnk(arcn);
883 else
884 res = chk_same(arcn);
885 if (res <= 0) {
886 if (vflag && vfpart) {
887 (void)putc('\n', listf);
888 vfpart = 0;
889 }
890 continue;
891 }
892
893 /*
894 * have to create a new file
895 */
896 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
897 /*
898 * create a link or special file
899 */
900 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
901 res = lnk_creat(arcn);
902 else
903 res = node_creat(arcn);
904 if (res < 0)
905 purg_lnk(arcn);
906 if (vflag && vfpart) {
907 (void)putc('\n', listf);
908 vfpart = 0;
909 }
910 continue;
911 }
912
913 /*
914 * have to copy a regular file to the destination directory.
915 * first open source file and then create the destination file
916 */
917 if ((fdsrc = open(arcn->org_name, O_RDONLY, 0)) < 0) {
918 syswarn(1, errno, "Unable to open %s to read",
919 arcn->org_name);
920 purg_lnk(arcn);
921 continue;
922 }
923 if ((fddest = file_creat(arcn)) < 0) {
924 rdfile_close(arcn, &fdsrc);
925 purg_lnk(arcn);
926 continue;
927 }
928
929 /*
930 * copy source file data to the destination file
931 */
932 cp_file(arcn, fdsrc, fddest);
933 file_close(arcn, fddest);
934 rdfile_close(arcn, &fdsrc);
935
936 if (vflag && vfpart) {
937 (void)putc('\n', listf);
938 vfpart = 0;
939 }
940 }
941
942 /*
943 * restore directory modes and times as required; make sure all
944 * patterns were selected block off signals to avoid chance for
945 * multiple entry into the cleanup code.
946 */
947 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
948 ar_close();
949 proc_dir();
950 ftree_chk();
951}
952
953/*
954 * next_head()
955 * try to find a valid header in the archive. Uses format specific
956 * routines to extract the header and id the trailer. Trailers may be
957 * located within a valid header or in an invalid header (the location
958 * is format specific. The inhead field from the option table tells us
959 * where to look for the trailer).
960 * We keep reading (and resyncing) until we get enough contiguous data
961 * to check for a header. If we cannot find one, we shift by a byte
962 * add a new byte from the archive to the end of the buffer and try again.
963 * If we get a read error, we throw out what we have (as we must have
964 * contiguous data) and start over again.
965 * ASSUMED: headers fit within a BLKMULT header.
966 * Return:
967 * 0 if we got a header, -1 if we are unable to ever find another one
968 * (we reached the end of input, or we reached the limit on retries. see
969 * the specs for rd_wrbuf() for more details)
970 */
971
972static int
973next_head(ARCHD *arcn)
974{
975 int ret;
976 char *hdend;
977 int res;
978 int shftsz;
979 int hsz;
980 int in_resync = 0; /* set when we are in resync mode */
981 int cnt = 0; /* counter for trailer function */
982 int first = 1; /* on 1st read, EOF isn't premature. */
983
984 /*
985 * set up initial conditions, we want a whole frmt->hsz block as we
986 * have no data yet.
987 */
988 res = hsz = frmt->hsz;
989 hdend = hdbuf;
990 shftsz = hsz - 1;
991 for(;;) {
992 /*
993 * keep looping until we get a contiguous FULL buffer
994 * (frmt->hsz is the proper size)
995 */
996 for (;;) {
997 if ((ret = rd_wrbuf(hdend, res)) == res)
998 break;
999
1000 /*
1001 * If we read 0 bytes (EOF) from an archive when we
1002 * expect to find a header, we have stepped upon
1003 * an archive without the customary block of zeroes
1004 * end marker. It's just stupid to error out on
1005 * them, so exit gracefully.
1006 */
1007 if (first && ret == 0)
1008 return(-1);
1009 first = 0;
1010
1011 /*
1012 * some kind of archive read problem, try to resync the
1013 * storage device, better give the user the bad news.
1014 */
1015 if ((ret == 0) || (rd_sync() < 0)) {
1016 paxwarn(1,"Premature end of file on archive read");
1017 return(-1);
1018 }
1019 if (!in_resync) {
1020 if (act == APPND) {
1021 paxwarn(1,
1022 "Archive I/O error, cannot continue");
1023 return(-1);
1024 }
1025 paxwarn(1,"Archive I/O error. Trying to recover.");
1026 ++in_resync;
1027 }
1028
1029 /*
1030 * oh well, throw it all out and start over
1031 */
1032 res = hsz;
1033 hdend = hdbuf;
1034 }
1035
1036 /*
1037 * ok we have a contiguous buffer of the right size. Call the
1038 * format read routine. If this was not a valid header and this
1039 * format stores trailers outside of the header, call the
1040 * format specific trailer routine to check for a trailer. We
1041 * have to watch out that we do not mis-identify file data or
1042 * block padding as a header or trailer. Format specific
1043 * trailer functions must NOT check for the trailer while we
1044 * are running in resync mode. Some trailer functions may tell
1045 * us that this block cannot contain a valid header either, so
1046 * we then throw out the entire block and start over.
1047 */
1048 if ((*frmt->rd)(arcn, hdbuf) == 0)
1049 break;
1050
1051 if (!frmt->inhead) {
1052 /*
1053 * this format has trailers outside of valid headers
1054 */
1055 if ((ret = (*frmt->trail_tar)(hdbuf,in_resync,&cnt)) == 0){
1056 /*
1057 * valid trailer found, drain input as required
1058 */
1059 ar_drain();
1060 return(-1);
1061 }
1062
1063 if (ret == 1) {
1064 /*
1065 * we are in resync and we were told to throw
1066 * the whole block out because none of the
1067 * bytes in this block can be used to form a
1068 * valid header
1069 */
1070 res = hsz;
1071 hdend = hdbuf;
1072 continue;
1073 }
1074 }
1075
1076 /*
1077 * Brute force section.
1078 * not a valid header. We may be able to find a header yet. So
1079 * we shift over by one byte, and set up to read one byte at a
1080 * time from the archive and place it at the end of the buffer.
1081 * We will keep moving byte at a time until we find a header or
1082 * get a read error and have to start over.
1083 */
1084 if (!in_resync) {
1085 if (act == APPND) {
1086 paxwarn(1,"Unable to append, archive header flaw");
1087 return(-1);
1088 }
1089 paxwarn(1,"Invalid header, starting valid header search.");
1090 ++in_resync;
1091 }
1092 memmove(hdbuf, hdbuf+1, shftsz);
1093 res = 1;
1094 hdend = hdbuf + shftsz;
1095 }
1096
1097 /*
1098 * ok got a valid header, check for trailer if format encodes it in the
1099 * the header.
1100 */
1101 if (frmt->inhead && ((*frmt->trail_cpio)(arcn) == 0)) {
1102 /*
1103 * valid trailer found, drain input as required
1104 */
1105 ar_drain();
1106 return(-1);
1107 }
1108
1109 ++flcnt;
1110 return(0);
1111}
1112
1113/*
1114 * get_arc()
1115 * Figure out what format an archive is. Handles archive with flaws by
1116 * brute force searches for a legal header in any supported format. The
1117 * format id routines have to be careful to NOT mis-identify a format.
1118 * ASSUMED: headers fit within a BLKMULT header.
1119 * Return:
1120 * 0 if archive found -1 otherwise
1121 */
1122
1123static int
1124get_arc(void)
1125{
1126 int i;
1127 int hdsz = 0;
1128 int res;
1129 int minhd = BLKMULT;
1130 char *hdend;
1131 int notice = 0;
1132
1133 /*
1134 * find the smallest header size in all archive formats and then set up
1135 * to read the archive.
1136 */
1137 for (i = 0; ford[i] >= 0; ++i) {
1138 if (fsub[ford[i]].hsz < minhd)
1139 minhd = fsub[ford[i]].hsz;
1140 }
1141 if (rd_start() < 0)
1142 return(-1);
1143 res = BLKMULT;
1144 hdsz = 0;
1145 hdend = hdbuf;
1146 for(;;) {
1147 for (;;) {
1148 /*
1149 * fill the buffer with at least the smallest header
1150 */
1151 i = rd_wrbuf(hdend, res);
1152 if (i > 0)
1153 hdsz += i;
1154 if (hdsz >= minhd)
1155 break;
1156
1157 /*
1158 * if we cannot recover from a read error quit
1159 */
1160 if ((i == 0) || (rd_sync() < 0))
1161 goto out;
1162
1163 /*
1164 * when we get an error none of the data we already
1165 * have can be used to create a legal header (we just
1166 * got an error in the middle), so we throw it all out
1167 * and refill the buffer with fresh data.
1168 */
1169 res = BLKMULT;
1170 hdsz = 0;
1171 hdend = hdbuf;
1172 if (!notice) {
1173 if (act == APPND)
1174 return(-1);
1175 paxwarn(1,"Cannot identify format. Searching...");
1176 ++notice;
1177 }
1178 }
1179
1180 /*
1181 * we have at least the size of the smallest header in any
1182 * archive format. Look to see if we have a match. The array
1183 * ford[] is used to specify the header id order to reduce the
1184 * chance of incorrectly id'ing a valid header (some formats
1185 * may be subsets of each other and the order would then be
1186 * important).
1187 */
1188 for (i = 0; ford[i] >= 0; ++i) {
1189 if ((*fsub[ford[i]].id)(hdbuf, hdsz) < 0)
1190 continue;
1191 frmt = &(fsub[ford[i]]);
1192 /*
1193 * yuck, to avoid slow special case code in the extract
1194 * routines, just push this header back as if it was
1195 * not seen. We have left extra space at start of the
1196 * buffer for this purpose. This is a bit ugly, but
1197 * adding all the special case code is far worse.
1198 */
1199 pback(hdbuf, hdsz);
1200 return(0);
1201 }
1202
1203 /*
1204 * We have a flawed archive, no match. we start searching, but
1205 * we never allow additions to flawed archives
1206 */
1207 if (!notice) {
1208 if (act == APPND)
1209 return(-1);
1210 paxwarn(1, "Cannot identify format. Searching...");
1211 ++notice;
1212 }
1213
1214 /*
1215 * brute force search for a header that we can id.
1216 * we shift through byte at a time. this is slow, but we cannot
1217 * determine the nature of the flaw in the archive in a
1218 * portable manner
1219 */
1220 if (--hdsz > 0) {
1221 memmove(hdbuf, hdbuf+1, hdsz);
1222 res = BLKMULT - hdsz;
1223 hdend = hdbuf + hdsz;
1224 } else {
1225 res = BLKMULT;
1226 hdend = hdbuf;
1227 hdsz = 0;
1228 }
1229 }
1230
1231 out:
1232 /*
1233 * we cannot find a header, bow, apologize and quit
1234 */
1235 paxwarn(1, "Sorry, unable to determine archive format.");
1236 return(-1);
1237}
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