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 * 3. 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 * @(#)ar_io.c 8.2 (Berkeley) 4/18/94
34 * $FreeBSD: src/bin/pax/ar_io.c,v 1.12.2.1 2001/08/01 05:03:11 obrien Exp $
35 * $DragonFly: src/bin/pax/ar_io.c,v 1.11 2006/09/27 21:58:08 pavalos Exp $
36 */
37
38 #include <sys/types.h>
39 #include <sys/ioctl.h>
40 #include <sys/mtio.h>
41 #include <sys/stat.h>
42 #include <sys/wait.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 #include "pax.h"
52 #include "options.h"
53 #include "extern.h"
54
55 /*
56 * Routines which deal directly with the archive I/O device/file.
57 */
58
59 #define DMOD 0666 /* default mode of created archives */
60 #define EXT_MODE O_RDONLY /* open mode for list/extract */
61 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */
62 #define APP_MODE O_RDWR /* mode for append */
63 #define STDO "<STDOUT>" /* pseudo name for stdout */
64 #define STDN "<STDIN>" /* pseudo name for stdin */
65 static int arfd = -1; /* archive file descriptor */
66 static int artyp = ISREG; /* archive type: file/FIFO/tape */
67 static int arvol = 1; /* archive volume number */
68 static int lstrval = -1; /* return value from last i/o */
69 static int io_ok; /* i/o worked on volume after resync */
70 static int did_io; /* did i/o ever occur on volume? */
71 static int done; /* set via tty termination */
72 static struct stat arsb; /* stat of archive device at open */
73 static int invld_rec; /* tape has out of spec record size */
74 static int wr_trail = 1; /* trailer was rewritten in append */
75 static int can_unlnk = 0; /* do we unlink null archives? */
76 char *arcname; /* printable name of archive */
77 const char *gzip_program; /* name of gzip program */
78 static pid_t zpid = -1; /* pid of child process */
79 int force_one_volume; /* 1 if we ignore volume changes */
80
81 static int get_phys (void);
82 extern sigset_t s_mask;
83 static void ar_start_gzip (int, const char *, int);
84
85 /*
86 * ar_open()
87 * Opens the next archive volume. Determines the type of the device and
88 * sets up block sizes as required by the archive device and the format.
89 * Note: we may be called with name == NULL on the first open only.
90 * Return:
91 * -1 on failure, 0 otherwise
92 */
93
94 int
ar_open(char * name)95 ar_open(char *name)
96 {
97 struct mtget mb;
98
99 if (arfd != -1)
100 close(arfd);
101 arfd = -1;
102 can_unlnk = did_io = io_ok = invld_rec = 0;
103 artyp = ISREG;
104 flcnt = 0;
105
106 /*
107 * open based on overall operation mode
108 */
109 switch (act) {
110 case LIST:
111 case EXTRACT:
112 if (name == NULL) {
113 arfd = STDIN_FILENO;
114 arcname = STDN;
115 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0)
116 syswarn(0, errno, "Failed open to read on %s", name);
117 if (arfd != -1 && gzip_program != NULL)
118 ar_start_gzip(arfd, gzip_program, 0);
119 break;
120 case ARCHIVE:
121 if (name == NULL) {
122 arfd = STDOUT_FILENO;
123 arcname = STDO;
124 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0)
125 syswarn(0, errno, "Failed open to write on %s", name);
126 else
127 can_unlnk = 1;
128 if (arfd != -1 && gzip_program != NULL)
129 ar_start_gzip(arfd, gzip_program, 1);
130 break;
131 case APPND:
132 if (name == NULL) {
133 arfd = STDOUT_FILENO;
134 arcname = STDO;
135 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0)
136 syswarn(0, errno, "Failed open to read/write on %s",
137 name);
138 break;
139 case COPY:
140 /*
141 * arfd not used in COPY mode
142 */
143 arcname = "<NONE>";
144 lstrval = 1;
145 return(0);
146 }
147 if (arfd < 0)
148 return(-1);
149
150 if (chdname != NULL) {
151 if (chdir(chdname) != 0) {
152 syswarn(1, errno, "Failed chdir to %s", chdname);
153 return(-1);
154 }
155 }
156 /*
157 * set up is based on device type
158 */
159 if (fstat(arfd, &arsb) < 0) {
160 syswarn(0, errno, "Failed stat on %s", arcname);
161 close(arfd);
162 arfd = -1;
163 can_unlnk = 0;
164 return(-1);
165 }
166 if (S_ISDIR(arsb.st_mode)) {
167 paxwarn(0, "Cannot write an archive on top of a directory %s",
168 arcname);
169 close(arfd);
170 arfd = -1;
171 can_unlnk = 0;
172 return(-1);
173 }
174
175 if (S_ISCHR(arsb.st_mode))
176 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE;
177 else if (S_ISBLK(arsb.st_mode))
178 artyp = ISBLK;
179 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE))
180 artyp = ISPIPE;
181 else
182 artyp = ISREG;
183
184 /*
185 * make sure we beyond any doubt that we only can unlink regular files
186 * we created
187 */
188 if (artyp != ISREG)
189 can_unlnk = 0;
190 /*
191 * if we are writing, we are done
192 */
193 if (act == ARCHIVE) {
194 blksz = rdblksz = wrblksz;
195 lstrval = 1;
196 return(0);
197 }
198
199 /*
200 * set default blksz on read. APPNDs writes rdblksz on the last volume
201 * On all new archive volumes, we shift to wrblksz (if the user
202 * specified one, otherwise we will continue to use rdblksz). We
203 * must set blocksize based on what kind of device the archive is
204 * stored.
205 */
206 switch(artyp) {
207 case ISTAPE:
208 /*
209 * Tape drives come in at least two flavors. Those that support
210 * variable sized records and those that have fixed sized
211 * records. They must be treated differently. For tape drives
212 * that support variable sized records, we must make large
213 * reads to make sure we get the entire record, otherwise we
214 * will just get the first part of the record (up to size we
215 * asked). Tapes with fixed sized records may or may not return
216 * multiple records in a single read. We really do not care
217 * what the physical record size is UNLESS we are going to
218 * append. (We will need the physical block size to rewrite
219 * the trailer). Only when we are appending do we go to the
220 * effort to figure out the true PHYSICAL record size.
221 */
222 blksz = rdblksz = MAXBLK;
223 break;
224 case ISPIPE:
225 case ISBLK:
226 case ISCHR:
227 /*
228 * Blocksize is not a major issue with these devices (but must
229 * be kept a multiple of 512). If the user specified a write
230 * block size, we use that to read. Under append, we must
231 * always keep blksz == rdblksz. Otherwise we go ahead and use
232 * the device optimal blocksize as (and if) returned by stat
233 * and if it is within pax specs.
234 */
235 if ((act == APPND) && wrblksz) {
236 blksz = rdblksz = wrblksz;
237 break;
238 }
239
240 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) &&
241 ((arsb.st_blksize % BLKMULT) == 0))
242 rdblksz = arsb.st_blksize;
243 else
244 rdblksz = DEVBLK;
245 /*
246 * For performance go for large reads when we can without harm
247 */
248 if ((act == APPND) || (artyp == ISCHR))
249 blksz = rdblksz;
250 else
251 blksz = MAXBLK;
252 break;
253 case ISREG:
254 /*
255 * if the user specified wrblksz works, use it. Under appends
256 * we must always keep blksz == rdblksz
257 */
258 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){
259 blksz = rdblksz = wrblksz;
260 break;
261 }
262 /*
263 * See if we can find the blocking factor from the file size
264 */
265 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT)
266 if ((arsb.st_size % rdblksz) == 0)
267 break;
268 /*
269 * When we cannot find a match, we may have a flawed archive.
270 */
271 if (rdblksz <= 0)
272 rdblksz = FILEBLK;
273 /*
274 * for performance go for large reads when we can
275 */
276 if (act == APPND)
277 blksz = rdblksz;
278 else
279 blksz = MAXBLK;
280 break;
281 default:
282 /*
283 * should never happen, worst case, slow...
284 */
285 blksz = rdblksz = BLKMULT;
286 break;
287 }
288 lstrval = 1;
289 return(0);
290 }
291
292 /*
293 * ar_close()
294 * closes archive device, increments volume number, and prints i/o summary
295 */
296 void
ar_close(void)297 ar_close(void)
298 {
299 int status;
300
301 if (arfd < 0) {
302 did_io = io_ok = flcnt = 0;
303 return;
304 }
305
306 /*
307 * Close archive file. This may take a LONG while on tapes (we may be
308 * forced to wait for the rewind to complete) so tell the user what is
309 * going on (this avoids the user hitting control-c thinking pax is
310 * broken).
311 */
312 if (vflag && (artyp == ISTAPE)) {
313 if (vfpart)
314 putc('\n', listf);
315 fprintf(listf,
316 "%s: Waiting for tape drive close to complete...",
317 argv0);
318 fflush(listf);
319 }
320
321 /*
322 * if nothing was written to the archive (and we created it), we remove
323 * it
324 */
325 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) &&
326 (arsb.st_size == 0)) {
327 unlink(arcname);
328 can_unlnk = 0;
329 }
330
331 /*
332 * for a quick extract/list, pax frequently exits before the child
333 * process is done
334 */
335 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0)
336 kill(zpid, SIGINT);
337
338 close(arfd);
339
340 /* Do not exit before child to ensure data integrity */
341 if (zpid > 0)
342 waitpid(zpid, &status, 0);
343
344 if (vflag && (artyp == ISTAPE)) {
345 fputs("done.\n", listf);
346 vfpart = 0;
347 fflush(listf);
348 }
349 arfd = -1;
350
351 if (!io_ok && !did_io) {
352 flcnt = 0;
353 return;
354 }
355 did_io = io_ok = 0;
356
357 /*
358 * The volume number is only increased when the last device has data
359 * and we have already determined the archive format.
360 */
361 if (frmt != NULL)
362 ++arvol;
363
364 if (!vflag) {
365 flcnt = 0;
366 return;
367 }
368
369 /*
370 * Print out a summary of I/O for this archive volume.
371 */
372 if (vfpart) {
373 putc('\n', listf);
374 vfpart = 0;
375 }
376
377 /*
378 * If we have not determined the format yet, we just say how many bytes
379 * we have skipped over looking for a header to id. there is no way we
380 * could have written anything yet.
381 */
382 if (frmt == NULL) {
383 fprintf(listf, "%s: unknown format, %jd bytes skipped.\n",
384 argv0, (intmax_t)rdcnt);
385 fflush(listf);
386 flcnt = 0;
387 return;
388 }
389
390 if (strcmp(NM_CPIO, argv0) == 0)
391 fprintf(listf, "%jdu blocks\n", (intmax_t)((rdcnt ? rdcnt : wrcnt) / 5120));
392 else if (strcmp(NM_TAR, argv0) != 0)
393 fprintf(listf,
394 "%s: %s vol %d, %lu files, %jd bytes read, %jd bytes written.\n",
395 argv0, frmt->name, arvol-1, flcnt,
396 (intmax_t)rdcnt, (intmax_t)wrcnt);
397 fflush(listf);
398 flcnt = 0;
399 }
400
401 /*
402 * ar_drain()
403 * drain any archive format independent padding from an archive read
404 * from a socket or a pipe. This is to prevent the process on the
405 * other side of the pipe from getting a SIGPIPE (pax will stop
406 * reading an archive once a format dependent trailer is detected).
407 */
408 void
ar_drain(void)409 ar_drain(void)
410 {
411 int res;
412 char drbuf[MAXBLK];
413
414 /*
415 * we only drain from a pipe/socket. Other devices can be closed
416 * without reading up to end of file. We sure hope that pipe is closed
417 * on the other side so we will get an EOF.
418 */
419 if ((artyp != ISPIPE) || (lstrval <= 0))
420 return;
421
422 /*
423 * keep reading until pipe is drained
424 */
425 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0)
426 ;
427 lstrval = res;
428 }
429
430 /*
431 * ar_set_wr()
432 * Set up device right before switching from read to write in an append.
433 * device dependent code (if required) to do this should be added here.
434 * For all archive devices we are already positioned at the place we want
435 * to start writing when this routine is called.
436 * Return:
437 * 0 if all ready to write, -1 otherwise
438 */
439
440 int
ar_set_wr(void)441 ar_set_wr(void)
442 {
443 off_t cpos;
444
445 /*
446 * we must make sure the trailer is rewritten on append, ar_next()
447 * will stop us if the archive containing the trailer was not written
448 */
449 wr_trail = 0;
450
451 /*
452 * Add any device dependent code as required here
453 */
454 if (artyp != ISREG)
455 return(0);
456 /*
457 * Ok we have an archive in a regular file. If we were rewriting a
458 * file, we must get rid of all the stuff after the current offset
459 * (it was not written by pax).
460 */
461 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) ||
462 (ftruncate(arfd, cpos) < 0)) {
463 syswarn(1, errno, "Unable to truncate archive file");
464 return(-1);
465 }
466 return(0);
467 }
468
469 /*
470 * ar_app_ok()
471 * check if the last volume in the archive allows appends. We cannot check
472 * this until we are ready to write since there is no spec that says all
473 * volumes in a single archive have to be of the same type...
474 * Return:
475 * 0 if we can append, -1 otherwise.
476 */
477
478 int
ar_app_ok(void)479 ar_app_ok(void)
480 {
481 if (artyp == ISPIPE) {
482 paxwarn(1, "Cannot append to an archive obtained from a pipe.");
483 return(-1);
484 }
485
486 if (!invld_rec)
487 return(0);
488 paxwarn(1,"Cannot append, device record size %d does not support %s spec",
489 rdblksz, argv0);
490 return(-1);
491 }
492
493 /*
494 * ar_read()
495 * read up to a specified number of bytes from the archive into the
496 * supplied buffer. When dealing with tapes we may not always be able to
497 * read what we want.
498 * Return:
499 * Number of bytes in buffer. 0 for end of file, -1 for a read error.
500 */
501
502 int
ar_read(char * buf,int cnt)503 ar_read(char *buf, int cnt)
504 {
505 int res = 0;
506
507 /*
508 * if last i/o was in error, no more reads until reset or new volume
509 */
510 if (lstrval <= 0)
511 return(lstrval);
512
513 /*
514 * how we read must be based on device type
515 */
516 switch (artyp) {
517 case ISTAPE:
518 if ((res = read(arfd, buf, cnt)) > 0) {
519 /*
520 * CAUTION: tape systems may not always return the same
521 * sized records so we leave blksz == MAXBLK. The
522 * physical record size that a tape drive supports is
523 * very hard to determine in a uniform and portable
524 * manner.
525 */
526 io_ok = 1;
527 if (res != rdblksz) {
528 /*
529 * Record size changed. If this happens on
530 * any record after the first, we probably have
531 * a tape drive which has a fixed record size
532 * (we are getting multiple records in a single
533 * read). Watch out for record blocking that
534 * violates pax spec (must be a multiple of
535 * BLKMULT).
536 */
537 rdblksz = res;
538 if (rdblksz % BLKMULT)
539 invld_rec = 1;
540 }
541 return(res);
542 }
543 break;
544 case ISREG:
545 case ISBLK:
546 case ISCHR:
547 case ISPIPE:
548 default:
549 /*
550 * Files are so easy to deal with. These other things cannot
551 * be trusted at all. So when we are dealing with character
552 * devices and pipes we just take what they have ready for us
553 * and return. Trying to do anything else with them runs the
554 * risk of failure.
555 */
556 if ((res = read(arfd, buf, cnt)) > 0) {
557 io_ok = 1;
558 return(res);
559 }
560 break;
561 }
562
563 /*
564 * We are in trouble at this point, something is broken...
565 */
566 lstrval = res;
567 if (res < 0)
568 syswarn(1, errno, "Failed read on archive volume %d", arvol);
569 else
570 paxwarn(0, "End of archive volume %d reached", arvol);
571 return(res);
572 }
573
574 /*
575 * ar_write()
576 * Write a specified number of bytes in supplied buffer to the archive
577 * device so it appears as a single "block". Deals with errors and tries
578 * to recover when faced with short writes.
579 * Return:
580 * Number of bytes written. 0 indicates end of volume reached and with no
581 * flaws (as best that can be detected). A -1 indicates an unrecoverable
582 * error in the archive occurred.
583 */
584
585 int
ar_write(char * buf,int bsz)586 ar_write(char *buf, int bsz)
587 {
588 int res;
589 off_t cpos;
590
591 /*
592 * do not allow pax to create a "bad" archive. Once a write fails on
593 * an archive volume prevent further writes to it.
594 */
595 if (lstrval <= 0)
596 return(lstrval);
597
598 if ((res = write(arfd, buf, bsz)) == bsz) {
599 wr_trail = 1;
600 io_ok = 1;
601 return(bsz);
602 }
603 /*
604 * write broke, see what we can do with it. We try to send any partial
605 * writes that may violate pax spec to the next archive volume.
606 */
607 if (res < 0)
608 lstrval = res;
609 else
610 lstrval = 0;
611
612 switch (artyp) {
613 case ISREG:
614 if ((res > 0) && (res % BLKMULT)) {
615 /*
616 * try to fix up partial writes which are not BLKMULT
617 * in size by forcing the runt record to next archive
618 * volume
619 */
620 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
621 break;
622 cpos -= (off_t)res;
623 if (ftruncate(arfd, cpos) < 0)
624 break;
625 res = lstrval = 0;
626 break;
627 }
628 if (res >= 0)
629 break;
630 /*
631 * if file is out of space, handle it like a return of 0
632 */
633 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT))
634 res = lstrval = 0;
635 break;
636 case ISTAPE:
637 case ISCHR:
638 case ISBLK:
639 if (res >= 0)
640 break;
641 if (errno == EACCES) {
642 paxwarn(0, "Write failed, archive is write protected.");
643 lstrval = 0;
644 return(0);
645 }
646 /*
647 * see if we reached the end of media, if so force a change to
648 * the next volume
649 */
650 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO))
651 res = lstrval = 0;
652 break;
653 case ISPIPE:
654 default:
655 /*
656 * we cannot fix errors to these devices
657 */
658 break;
659 }
660
661 /*
662 * Better tell the user the bad news...
663 * if this is a block aligned archive format, we may have a bad archive
664 * if the format wants the header to start at a BLKMULT boundary. While
665 * we can deal with the mis-aligned data, it violates spec and other
666 * archive readers will likely fail. if the format is not block
667 * aligned, the user may be lucky (and the archive is ok).
668 */
669 if (res >= 0) {
670 if (res > 0)
671 wr_trail = 1;
672 io_ok = 1;
673 }
674
675 /*
676 * If we were trying to rewrite the trailer and it didn't work, we
677 * must quit right away.
678 */
679 if (!wr_trail && (res <= 0)) {
680 paxwarn(1,"Unable to append, trailer re-write failed. Quitting.");
681 return(res);
682 }
683
684 if (res == 0)
685 paxwarn(0, "End of archive volume %d reached", arvol);
686 else if (res < 0)
687 syswarn(1, errno, "Failed write to archive volume: %d", arvol);
688 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0))
689 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED");
690 else
691 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED");
692 return(res);
693 }
694
695 /*
696 * ar_rdsync()
697 * Try to move past a bad spot on a flawed archive as needed to continue
698 * I/O. Clears error flags to allow I/O to continue.
699 * Return:
700 * 0 when ok to try i/o again, -1 otherwise.
701 */
702
703 int
ar_rdsync(void)704 ar_rdsync(void)
705 {
706 long fsbz;
707 off_t cpos;
708 off_t mpos;
709 struct mtop mb;
710
711 /*
712 * Fail resync attempts at user request (done) or if this is going to be
713 * an update/append to a existing archive. if last i/o hit media end,
714 * we need to go to the next volume not try a resync
715 */
716 if ((done > 0) || (lstrval == 0))
717 return(-1);
718
719 if ((act == APPND) || (act == ARCHIVE)) {
720 paxwarn(1, "Cannot allow updates to an archive with flaws.");
721 return(-1);
722 }
723 if (io_ok)
724 did_io = 1;
725
726 switch(artyp) {
727 case ISTAPE:
728 /*
729 * if the last i/o was a successful data transfer, we assume
730 * the fault is just a bad record on the tape that we are now
731 * past. If we did not get any data since the last resync try
732 * to move the tape forward one PHYSICAL record past any
733 * damaged tape section. Some tape drives are stubborn and need
734 * to be pushed.
735 */
736 if (io_ok) {
737 io_ok = 0;
738 lstrval = 1;
739 break;
740 }
741 mb.mt_op = MTFSR;
742 mb.mt_count = 1;
743 if (ioctl(arfd, MTIOCTOP, &mb) < 0)
744 break;
745 lstrval = 1;
746 break;
747 case ISREG:
748 case ISCHR:
749 case ISBLK:
750 /*
751 * try to step over the bad part of the device.
752 */
753 io_ok = 0;
754 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG))
755 fsbz = BLKMULT;
756 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
757 break;
758 mpos = fsbz - (cpos % (off_t)fsbz);
759 if (lseek(arfd, mpos, SEEK_CUR) < 0)
760 break;
761 lstrval = 1;
762 break;
763 case ISPIPE:
764 default:
765 /*
766 * cannot recover on these archive device types
767 */
768 io_ok = 0;
769 break;
770 }
771 if (lstrval <= 0) {
772 paxwarn(1, "Unable to recover from an archive read failure.");
773 return(-1);
774 }
775 paxwarn(0, "Attempting to recover from an archive read failure.");
776 return(0);
777 }
778
779 /*
780 * ar_fow()
781 * Move the I/O position within the archive forward the specified number of
782 * bytes as supported by the device. If we cannot move the requested
783 * number of bytes, return the actual number of bytes moved in skipped.
784 * Return:
785 * 0 if moved the requested distance, -1 on complete failure, 1 on
786 * partial move (the amount moved is in skipped)
787 */
788
789 int
ar_fow(off_t sksz,off_t * skipped)790 ar_fow(off_t sksz, off_t *skipped)
791 {
792 off_t cpos;
793 off_t mpos;
794
795 *skipped = 0;
796 if (sksz <= 0)
797 return(0);
798
799 /*
800 * we cannot move forward at EOF or error
801 */
802 if (lstrval <= 0)
803 return(lstrval);
804
805 /*
806 * Safer to read forward on devices where it is hard to find the end of
807 * the media without reading to it. With tapes we cannot be sure of the
808 * number of physical blocks to skip (we do not know physical block
809 * size at this point), so we must only read forward on tapes!
810 */
811 if (artyp != ISREG)
812 return(0);
813
814 /*
815 * figure out where we are in the archive
816 */
817 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) {
818 /*
819 * we can be asked to move farther than there are bytes in this
820 * volume, if so, just go to file end and let normal buf_fill()
821 * deal with the end of file (it will go to next volume by
822 * itself)
823 */
824 if ((mpos = cpos + sksz) > arsb.st_size) {
825 *skipped = arsb.st_size - cpos;
826 mpos = arsb.st_size;
827 } else
828 *skipped = sksz;
829 if (lseek(arfd, mpos, SEEK_SET) >= 0)
830 return(0);
831 }
832 syswarn(1, errno, "Forward positioning operation on archive failed");
833 lstrval = -1;
834 return(-1);
835 }
836
837 /*
838 * ar_rev()
839 * move the i/o position within the archive backwards the specified byte
840 * count as supported by the device. With tapes drives we RESET rdblksz to
841 * the PHYSICAL blocksize.
842 * NOTE: We should only be called to move backwards so we can rewrite the
843 * last records (the trailer) of an archive (APPEND).
844 * Return:
845 * 0 if moved the requested distance, -1 on complete failure
846 */
847
848 int
ar_rev(off_t sksz)849 ar_rev(off_t sksz)
850 {
851 off_t cpos;
852 struct mtop mb;
853 int phyblk;
854
855 /*
856 * make sure we do not have try to reverse on a flawed archive
857 */
858 if (lstrval < 0)
859 return(lstrval);
860
861 switch(artyp) {
862 case ISPIPE:
863 if (sksz <= 0)
864 break;
865 /*
866 * cannot go backwards on these critters
867 */
868 paxwarn(1, "Reverse positioning on pipes is not supported.");
869 lstrval = -1;
870 return(-1);
871 case ISREG:
872 case ISBLK:
873 case ISCHR:
874 default:
875 if (sksz <= 0)
876 break;
877
878 /*
879 * For things other than files, backwards movement has a very
880 * high probability of failure as we really do not know the
881 * true attributes of the device we are talking to (the device
882 * may not even have the ability to lseek() in any direction).
883 * First we figure out where we are in the archive.
884 */
885 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) {
886 syswarn(1, errno,
887 "Unable to obtain current archive byte offset");
888 lstrval = -1;
889 return(-1);
890 }
891
892 /*
893 * we may try to go backwards past the start when the archive
894 * is only a single record. If this happens and we are on a
895 * multi-volume archive, we need to go to the end of the
896 * previous volume and continue our movement backwards from
897 * there.
898 */
899 if ((cpos -= sksz) < (off_t)0L) {
900 if (arvol > 1) {
901 /*
902 * this should never happen
903 */
904 paxwarn(1,"Reverse position on previous volume.");
905 lstrval = -1;
906 return(-1);
907 }
908 cpos = (off_t)0L;
909 }
910 if (lseek(arfd, cpos, SEEK_SET) < 0) {
911 syswarn(1, errno, "Unable to seek archive backwards");
912 lstrval = -1;
913 return(-1);
914 }
915 break;
916 case ISTAPE:
917 /*
918 * Calculate and move the proper number of PHYSICAL tape
919 * blocks. If the sksz is not an even multiple of the physical
920 * tape size, we cannot do the move (this should never happen).
921 * (We also cannot handle trailers spread over two vols.)
922 * get_phys() also makes sure we are in front of the filemark.
923 */
924 if ((phyblk = get_phys()) <= 0) {
925 lstrval = -1;
926 return(-1);
927 }
928
929 /*
930 * make sure future tape reads only go by physical tape block
931 * size (set rdblksz to the real size).
932 */
933 rdblksz = phyblk;
934
935 /*
936 * if no movement is required, just return (we must be after
937 * get_phys() so the physical blocksize is properly set)
938 */
939 if (sksz <= 0)
940 break;
941
942 /*
943 * ok we have to move. Make sure the tape drive can do it.
944 */
945 if (sksz % phyblk) {
946 paxwarn(1,
947 "Tape drive unable to backspace requested amount");
948 lstrval = -1;
949 return(-1);
950 }
951
952 /*
953 * move backwards the requested number of bytes
954 */
955 mb.mt_op = MTBSR;
956 mb.mt_count = sksz/phyblk;
957 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
958 syswarn(1,errno, "Unable to backspace tape %d blocks.",
959 mb.mt_count);
960 lstrval = -1;
961 return(-1);
962 }
963 break;
964 }
965 lstrval = 1;
966 return(0);
967 }
968
969 /*
970 * get_phys()
971 * Determine the physical block size on a tape drive. We need the physical
972 * block size so we know how many bytes we skip over when we move with
973 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when
974 * return.
975 * This is one really SLOW routine...
976 * Return:
977 * physical block size if ok (ok > 0), -1 otherwise
978 */
979
980 static int
get_phys(void)981 get_phys(void)
982 {
983 int padsz = 0;
984 int res;
985 int phyblk;
986 struct mtop mb;
987 char scbuf[MAXBLK];
988
989 /*
990 * move to the file mark, and then back up one record and read it.
991 * this should tell us the physical record size the tape is using.
992 */
993 if (lstrval == 1) {
994 /*
995 * we know we are at file mark when we get back a 0 from
996 * read()
997 */
998 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
999 padsz += res;
1000 if (res < 0) {
1001 syswarn(1, errno, "Unable to locate tape filemark.");
1002 return(-1);
1003 }
1004 }
1005
1006 /*
1007 * move backwards over the file mark so we are at the end of the
1008 * last record.
1009 */
1010 mb.mt_op = MTBSF;
1011 mb.mt_count = 1;
1012 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1013 syswarn(1, errno, "Unable to backspace over tape filemark.");
1014 return(-1);
1015 }
1016
1017 /*
1018 * move backwards so we are in front of the last record and read it to
1019 * get physical tape blocksize.
1020 */
1021 mb.mt_op = MTBSR;
1022 mb.mt_count = 1;
1023 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1024 syswarn(1, errno, "Unable to backspace over last tape block.");
1025 return(-1);
1026 }
1027 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) {
1028 syswarn(1, errno, "Cannot determine archive tape blocksize.");
1029 return(-1);
1030 }
1031
1032 /*
1033 * read forward to the file mark, then back up in front of the filemark
1034 * (this is a bit paranoid, but should be safe to do).
1035 */
1036 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
1037 ;
1038 if (res < 0) {
1039 syswarn(1, errno, "Unable to locate tape filemark.");
1040 return(-1);
1041 }
1042 mb.mt_op = MTBSF;
1043 mb.mt_count = 1;
1044 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1045 syswarn(1, errno, "Unable to backspace over tape filemark.");
1046 return(-1);
1047 }
1048
1049 /*
1050 * set lstrval so we know that the filemark has not been seen
1051 */
1052 lstrval = 1;
1053
1054 /*
1055 * return if there was no padding
1056 */
1057 if (padsz == 0)
1058 return(phyblk);
1059
1060 /*
1061 * make sure we can move backwards over the padding. (this should
1062 * never fail).
1063 */
1064 if (padsz % phyblk) {
1065 paxwarn(1, "Tape drive unable to backspace requested amount");
1066 return(-1);
1067 }
1068
1069 /*
1070 * move backwards over the padding so the head is where it was when
1071 * we were first called (if required).
1072 */
1073 mb.mt_op = MTBSR;
1074 mb.mt_count = padsz/phyblk;
1075 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1076 syswarn(1,errno,"Unable to backspace tape over %d pad blocks",
1077 mb.mt_count);
1078 return(-1);
1079 }
1080 return(phyblk);
1081 }
1082
1083 /*
1084 * ar_next()
1085 * prompts the user for the next volume in this archive. For some devices
1086 * we may allow the media to be changed. Otherwise a new archive is
1087 * prompted for. By pax spec, if there is no controlling tty or an eof is
1088 * read on tty input, we must quit pax.
1089 * Return:
1090 * 0 when ready to continue, -1 when all done
1091 */
1092
1093 int
ar_next(void)1094 ar_next(void)
1095 {
1096 char buf[PAXPATHLEN+2];
1097 static int freeit = 0;
1098 sigset_t o_mask;
1099
1100 /*
1101 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so
1102 * things like writing EOF etc will be done) (Watch out ar_close() can
1103 * also be called via a signal handler, so we must prevent a race.
1104 */
1105 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0)
1106 syswarn(0, errno, "Unable to set signal mask");
1107 ar_close();
1108 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0)
1109 syswarn(0, errno, "Unable to restore signal mask");
1110
1111 if (done || !wr_trail || force_one_volume || strcmp(NM_TAR, argv0) == 0)
1112 return(-1);
1113
1114 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0);
1115
1116 /*
1117 * if i/o is on stdin or stdout, we cannot reopen it (we do not know
1118 * the name), the user will be forced to type it in.
1119 */
1120 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG)
1121 && (artyp != ISPIPE)) {
1122 if (artyp == ISTAPE) {
1123 tty_prnt("%s ready for archive tape volume: %d\n",
1124 arcname, arvol);
1125 tty_prnt("Load the NEXT TAPE on the tape drive");
1126 } else {
1127 tty_prnt("%s ready for archive volume: %d\n",
1128 arcname, arvol);
1129 tty_prnt("Load the NEXT STORAGE MEDIA (if required)");
1130 }
1131
1132 if ((act == ARCHIVE) || (act == APPND))
1133 tty_prnt(" and make sure it is WRITE ENABLED.\n");
1134 else
1135 tty_prnt("\n");
1136
1137 for(;;) {
1138 tty_prnt("Type \"y\" to continue, \".\" to quit %s,",
1139 argv0);
1140 tty_prnt(" or \"s\" to switch to new device.\nIf you");
1141 tty_prnt(" cannot change storage media, type \"s\"\n");
1142 tty_prnt("Is the device ready and online? > ");
1143
1144 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){
1145 done = 1;
1146 lstrval = -1;
1147 tty_prnt("Quitting %s!\n", argv0);
1148 vfpart = 0;
1149 return(-1);
1150 }
1151
1152 if ((buf[0] == '\0') || (buf[1] != '\0')) {
1153 tty_prnt("%s unknown command, try again\n",buf);
1154 continue;
1155 }
1156
1157 switch (buf[0]) {
1158 case 'y':
1159 case 'Y':
1160 /*
1161 * we are to continue with the same device
1162 */
1163 if (ar_open(arcname) >= 0)
1164 return(0);
1165 tty_prnt("Cannot re-open %s, try again\n",
1166 arcname);
1167 continue;
1168 case 's':
1169 case 'S':
1170 /*
1171 * user wants to open a different device
1172 */
1173 tty_prnt("Switching to a different archive\n");
1174 break;
1175 default:
1176 tty_prnt("%s unknown command, try again\n",buf);
1177 continue;
1178 }
1179 break;
1180 }
1181 } else
1182 tty_prnt("Ready for archive volume: %d\n", arvol);
1183
1184 /*
1185 * have to go to a different archive
1186 */
1187 for (;;) {
1188 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0);
1189 tty_prnt("Archive name > ");
1190
1191 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) {
1192 done = 1;
1193 lstrval = -1;
1194 tty_prnt("Quitting %s!\n", argv0);
1195 vfpart = 0;
1196 return(-1);
1197 }
1198 if (buf[0] == '\0') {
1199 tty_prnt("Empty file name, try again\n");
1200 continue;
1201 }
1202 if (!strcmp(buf, "..")) {
1203 tty_prnt("Illegal file name: .. try again\n");
1204 continue;
1205 }
1206 if (strlen(buf) > PAXPATHLEN) {
1207 tty_prnt("File name too long, try again\n");
1208 continue;
1209 }
1210
1211 /*
1212 * try to open new archive
1213 */
1214 if (ar_open(buf) >= 0) {
1215 if (freeit) {
1216 free(arcname);
1217 freeit = 0;
1218 }
1219 if ((arcname = strdup(buf)) == NULL) {
1220 done = 1;
1221 lstrval = -1;
1222 paxwarn(0, "Cannot save archive name.");
1223 return(-1);
1224 }
1225 freeit = 1;
1226 break;
1227 }
1228 tty_prnt("Cannot open %s, try again\n", buf);
1229 continue;
1230 }
1231 return(0);
1232 }
1233
1234 /*
1235 * ar_start_gzip()
1236 * starts the gzip compression/decompression process as a child, using magic
1237 * to keep the fd the same in the calling function (parent).
1238 */
1239 void
ar_start_gzip(int fd,const char * gzip_program,int wr)1240 ar_start_gzip(int fd, const char *gzip_program, int wr)
1241 {
1242 int fds[2];
1243 char *gzip_flags;
1244
1245 if (pipe(fds) < 0)
1246 err(1, "could not pipe");
1247 zpid = fork();
1248 if (zpid < 0)
1249 err(1, "could not fork");
1250
1251 /* parent */
1252 if (zpid) {
1253 if (wr)
1254 dup2(fds[1], fd);
1255 else
1256 dup2(fds[0], fd);
1257 close(fds[0]);
1258 close(fds[1]);
1259 } else {
1260 if (wr) {
1261 dup2(fds[0], STDIN_FILENO);
1262 dup2(fd, STDOUT_FILENO);
1263 gzip_flags = "-c";
1264 } else {
1265 dup2(fds[1], STDOUT_FILENO);
1266 dup2(fd, STDIN_FILENO);
1267 gzip_flags = "-dc";
1268 }
1269 close(fds[0]);
1270 close(fds[1]);
1271 if (execlp(gzip_program, gzip_program, gzip_flags, NULL) < 0)
1272 err(1, "could not exec");
1273 /* NOTREACHED */
1274 }
1275 }
1276