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
36 static char sccsid[] = "@(#)ar_io.c 8.2 (Berkeley) 4/18/94";
37 #endif
38 #endif /* not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include <sys/types.h>
43 #include <sys/ioctl.h>
44 #include <sys/mtio.h>
45 #include <sys/stat.h>
46 #include <sys/wait.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <signal.h>
51 #include <stdint.h>
52 #include <stdio.h>
53 #include <string.h>
54 #include <stdlib.h>
55 #include <unistd.h>
56 #include "pax.h"
57 #include "options.h"
58 #include "extern.h"
59
60 /*
61 * Routines which deal directly with the archive I/O device/file.
62 */
63
64 #define DMOD 0666 /* default mode of created archives */
65 #define EXT_MODE O_RDONLY /* open mode for list/extract */
66 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */
67 #define APP_MODE O_RDWR /* mode for append */
68
69 static char none[] = "<NONE>"; /* pseudo name for no file */
70 static char stdo[] = "<STDOUT>"; /* pseudo name for stdout */
71 static char stdn[] = "<STDIN>"; /* pseudo name for stdin */
72 static int arfd = -1; /* archive file descriptor */
73 static int artyp = ISREG; /* archive type: file/FIFO/tape */
74 static int arvol = 1; /* archive volume number */
75 static int lstrval = -1; /* return value from last i/o */
76 static int io_ok; /* i/o worked on volume after resync */
77 static int did_io; /* did i/o ever occur on volume? */
78 static int done; /* set via tty termination */
79 static struct stat arsb; /* stat of archive device at open */
80 static int invld_rec; /* tape has out of spec record size */
81 static int wr_trail = 1; /* trailer was rewritten in append */
82 static int can_unlnk = 0; /* do we unlink null archives? */
83 const char *arcname; /* printable name of archive */
84 const char *gzip_program; /* name of gzip program */
85 static pid_t zpid = -1; /* pid of child process */
86
87 static int get_phys(void);
88 static void ar_start_gzip(int, const char *, int);
89
90 /*
91 * ar_open()
92 * Opens the next archive volume. Determines the type of the device and
93 * sets up block sizes as required by the archive device and the format.
94 * Note: we may be called with name == NULL on the first open only.
95 * Return:
96 * -1 on failure, 0 otherwise
97 */
98
99 int
ar_open(const char * name)100 ar_open(const char *name)
101 {
102 struct mtget mb;
103
104 if (arfd != -1)
105 (void)close(arfd);
106 arfd = -1;
107 can_unlnk = did_io = io_ok = invld_rec = 0;
108 artyp = ISREG;
109 flcnt = 0;
110
111 /*
112 * open based on overall operation mode
113 */
114 switch (act) {
115 case LIST:
116 case EXTRACT:
117 if (name == NULL) {
118 arfd = STDIN_FILENO;
119 arcname = stdn;
120 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0)
121 syswarn(0, errno, "Failed open to read on %s", name);
122 if (arfd != -1 && gzip_program != NULL)
123 ar_start_gzip(arfd, gzip_program, 0);
124 break;
125 case ARCHIVE:
126 if (name == NULL) {
127 arfd = STDOUT_FILENO;
128 arcname = stdo;
129 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0)
130 syswarn(0, errno, "Failed open to write on %s", name);
131 else
132 can_unlnk = 1;
133 if (arfd != -1 && gzip_program != NULL)
134 ar_start_gzip(arfd, gzip_program, 1);
135 break;
136 case APPND:
137 if (name == NULL) {
138 arfd = STDOUT_FILENO;
139 arcname = stdo;
140 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0)
141 syswarn(0, errno, "Failed open to read/write on %s",
142 name);
143 break;
144 case COPY:
145 /*
146 * arfd not used in COPY mode
147 */
148 arcname = none;
149 lstrval = 1;
150 return(0);
151 }
152 if (arfd < 0)
153 return(-1);
154
155 if (chdname != NULL)
156 if (chdir(chdname) != 0) {
157 syswarn(1, errno, "Failed chdir to %s", chdname);
158 return(-1);
159 }
160 /*
161 * set up is based on device type
162 */
163 if (fstat(arfd, &arsb) < 0) {
164 syswarn(0, errno, "Failed stat on %s", arcname);
165 (void)close(arfd);
166 arfd = -1;
167 can_unlnk = 0;
168 return(-1);
169 }
170 if (S_ISDIR(arsb.st_mode)) {
171 paxwarn(0, "Cannot write an archive on top of a directory %s",
172 arcname);
173 (void)close(arfd);
174 arfd = -1;
175 can_unlnk = 0;
176 return(-1);
177 }
178
179 if (S_ISCHR(arsb.st_mode))
180 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE;
181 else if (S_ISBLK(arsb.st_mode))
182 artyp = ISBLK;
183 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE))
184 artyp = ISPIPE;
185 else
186 artyp = ISREG;
187
188 /*
189 * make sure we beyond any doubt that we only can unlink regular files
190 * we created
191 */
192 if (artyp != ISREG)
193 can_unlnk = 0;
194 /*
195 * if we are writing, we are done
196 */
197 if (act == ARCHIVE) {
198 blksz = rdblksz = wrblksz;
199 lstrval = 1;
200 return(0);
201 }
202
203 /*
204 * set default blksz on read. APPNDs writes rdblksz on the last volume
205 * On all new archive volumes, we shift to wrblksz (if the user
206 * specified one, otherwise we will continue to use rdblksz). We
207 * must to set blocksize based on what kind of device the archive is
208 * stored.
209 */
210 switch(artyp) {
211 case ISTAPE:
212 /*
213 * Tape drives come in at least two flavors. Those that support
214 * variable sized records and those that have fixed sized
215 * records. They must be treated differently. For tape drives
216 * that support variable sized records, we must make large
217 * reads to make sure we get the entire record, otherwise we
218 * will just get the first part of the record (up to size we
219 * asked). Tapes with fixed sized records may or may not return
220 * multiple records in a single read. We really do not care
221 * what the physical record size is UNLESS we are going to
222 * append. (We will need the physical block size to rewrite
223 * the trailer). Only when we are appending do we go to the
224 * effort to figure out the true PHYSICAL record size.
225 */
226 blksz = rdblksz = MAXBLK;
227 break;
228 case ISPIPE:
229 case ISBLK:
230 case ISCHR:
231 /*
232 * Blocksize is not a major issue with these devices (but must
233 * be kept a multiple of 512). If the user specified a write
234 * block size, we use that to read. Under append, we must
235 * always keep blksz == rdblksz. Otherwise we go ahead and use
236 * the device optimal blocksize as (and if) returned by stat
237 * and if it is within pax specs.
238 */
239 if ((act == APPND) && wrblksz) {
240 blksz = rdblksz = wrblksz;
241 break;
242 }
243
244 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) &&
245 ((arsb.st_blksize % BLKMULT) == 0))
246 rdblksz = arsb.st_blksize;
247 else
248 rdblksz = DEVBLK;
249 /*
250 * For performance go for large reads when we can without harm
251 */
252 if ((act == APPND) || (artyp == ISCHR))
253 blksz = rdblksz;
254 else
255 blksz = MAXBLK;
256 break;
257 case ISREG:
258 /*
259 * if the user specified wrblksz works, use it. Under appends
260 * we must always keep blksz == rdblksz
261 */
262 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){
263 blksz = rdblksz = wrblksz;
264 break;
265 }
266 /*
267 * See if we can find the blocking factor from the file size
268 */
269 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT)
270 if ((arsb.st_size % rdblksz) == 0)
271 break;
272 /*
273 * When we cannot find a match, we may have a flawed archive.
274 */
275 if (rdblksz <= 0)
276 rdblksz = FILEBLK;
277 /*
278 * for performance go for large reads when we can
279 */
280 if (act == APPND)
281 blksz = rdblksz;
282 else
283 blksz = MAXBLK;
284 break;
285 default:
286 /*
287 * should never happen, worse case, slow...
288 */
289 blksz = rdblksz = BLKMULT;
290 break;
291 }
292 lstrval = 1;
293 return(0);
294 }
295
296 /*
297 * ar_close()
298 * closes archive device, increments volume number, and prints i/o summary
299 */
300 void
ar_close(void)301 ar_close(void)
302 {
303 int status;
304
305 if (arfd < 0) {
306 did_io = io_ok = flcnt = 0;
307 return;
308 }
309
310 /*
311 * Close archive file. This may take a LONG while on tapes (we may be
312 * forced to wait for the rewind to complete) so tell the user what is
313 * going on (this avoids the user hitting control-c thinking pax is
314 * broken).
315 */
316 if (vflag && (artyp == ISTAPE)) {
317 if (vfpart)
318 (void)putc('\n', listf);
319 (void)fprintf(listf,
320 "%s: Waiting for tape drive close to complete...",
321 argv0);
322 (void)fflush(listf);
323 }
324
325 /*
326 * if nothing was written to the archive (and we created it), we remove
327 * it
328 */
329 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) &&
330 (arsb.st_size == 0)) {
331 (void)unlink(arcname);
332 can_unlnk = 0;
333 }
334
335 /*
336 * for a quick extract/list, pax frequently exits before the child
337 * process is done
338 */
339 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0)
340 kill(zpid, SIGINT);
341
342 (void)close(arfd);
343
344 /* Do not exit before child to ensure data integrity */
345 if (zpid > 0)
346 waitpid(zpid, &status, 0);
347
348 if (vflag && (artyp == ISTAPE)) {
349 (void)fputs("done.\n", listf);
350 vfpart = 0;
351 (void)fflush(listf);
352 }
353 arfd = -1;
354
355 if (!io_ok && !did_io) {
356 flcnt = 0;
357 return;
358 }
359 did_io = io_ok = 0;
360
361 /*
362 * The volume number is only increased when the last device has data
363 * and we have already determined the archive format.
364 */
365 if (frmt != NULL)
366 ++arvol;
367
368 if (!vflag) {
369 flcnt = 0;
370 return;
371 }
372
373 /*
374 * Print out a summary of I/O for this archive volume.
375 */
376 if (vfpart) {
377 (void)putc('\n', listf);
378 vfpart = 0;
379 }
380
381 /*
382 * If we have not determined the format yet, we just say how many bytes
383 * we have skipped over looking for a header to id. There is no way we
384 * could have written anything yet.
385 */
386 if (frmt == NULL) {
387 # ifdef NET2_STAT
388 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n",
389 argv0, rdcnt);
390 # else
391 (void)fprintf(listf, "%s: unknown format, %ju bytes skipped.\n",
392 argv0, (uintmax_t)rdcnt);
393 # endif
394 (void)fflush(listf);
395 flcnt = 0;
396 return;
397 }
398
399 if (strcmp(NM_CPIO, argv0) == 0)
400 (void)fprintf(listf, "%llu blocks\n",
401 (unsigned long long)((rdcnt ? rdcnt : wrcnt) / 5120));
402 else if (strcmp(NM_TAR, argv0) != 0)
403 (void)fprintf(listf,
404 # ifdef NET2_STAT
405 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n",
406 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt);
407 # else
408 "%s: %s vol %d, %ju files, %ju bytes read, %ju bytes written.\n",
409 argv0, frmt->name, arvol-1, (uintmax_t)flcnt,
410 (uintmax_t)rdcnt, (uintmax_t)wrcnt);
411 # endif
412 (void)fflush(listf);
413 flcnt = 0;
414 }
415
416 /*
417 * ar_drain()
418 * drain any archive format independent padding from an archive read
419 * from a socket or a pipe. This is to prevent the process on the
420 * other side of the pipe from getting a SIGPIPE (pax will stop
421 * reading an archive once a format dependent trailer is detected).
422 */
423 void
ar_drain(void)424 ar_drain(void)
425 {
426 int res;
427 char drbuf[MAXBLK];
428
429 /*
430 * we only drain from a pipe/socket. Other devices can be closed
431 * without reading up to end of file. We sure hope that pipe is closed
432 * on the other side so we will get an EOF.
433 */
434 if ((artyp != ISPIPE) || (lstrval <= 0))
435 return;
436
437 /*
438 * keep reading until pipe is drained
439 */
440 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0)
441 ;
442 lstrval = res;
443 }
444
445 /*
446 * ar_set_wr()
447 * Set up device right before switching from read to write in an append.
448 * device dependent code (if required) to do this should be added here.
449 * For all archive devices we are already positioned at the place we want
450 * to start writing when this routine is called.
451 * Return:
452 * 0 if all ready to write, -1 otherwise
453 */
454
455 int
ar_set_wr(void)456 ar_set_wr(void)
457 {
458 off_t cpos;
459
460 /*
461 * we must make sure the trailer is rewritten on append, ar_next()
462 * will stop us if the archive containing the trailer was not written
463 */
464 wr_trail = 0;
465
466 /*
467 * Add any device dependent code as required here
468 */
469 if (artyp != ISREG)
470 return(0);
471 /*
472 * Ok we have an archive in a regular file. If we were rewriting a
473 * file, we must get rid of all the stuff after the current offset
474 * (it was not written by pax).
475 */
476 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) ||
477 (ftruncate(arfd, cpos) < 0)) {
478 syswarn(1, errno, "Unable to truncate archive file");
479 return(-1);
480 }
481 return(0);
482 }
483
484 /*
485 * ar_app_ok()
486 * check if the last volume in the archive allows appends. We cannot check
487 * this until we are ready to write since there is no spec that says all
488 * volumes in a single archive have to be of the same type...
489 * Return:
490 * 0 if we can append, -1 otherwise.
491 */
492
493 int
ar_app_ok(void)494 ar_app_ok(void)
495 {
496 if (artyp == ISPIPE) {
497 paxwarn(1, "Cannot append to an archive obtained from a pipe.");
498 return(-1);
499 }
500
501 if (!invld_rec)
502 return(0);
503 paxwarn(1,"Cannot append, device record size %d does not support %s spec",
504 rdblksz, argv0);
505 return(-1);
506 }
507
508 /*
509 * ar_read()
510 * read up to a specified number of bytes from the archive into the
511 * supplied buffer. When dealing with tapes we may not always be able to
512 * read what we want.
513 * Return:
514 * Number of bytes in buffer. 0 for end of file, -1 for a read error.
515 */
516
517 int
ar_read(char * buf,int cnt)518 ar_read(char *buf, int cnt)
519 {
520 int res = 0;
521
522 /*
523 * if last i/o was in error, no more reads until reset or new volume
524 */
525 if (lstrval <= 0)
526 return(lstrval);
527
528 /*
529 * how we read must be based on device type
530 */
531 switch (artyp) {
532 case ISTAPE:
533 if ((res = read(arfd, buf, cnt)) > 0) {
534 /*
535 * CAUTION: tape systems may not always return the same
536 * sized records so we leave blksz == MAXBLK. The
537 * physical record size that a tape drive supports is
538 * very hard to determine in a uniform and portable
539 * manner.
540 */
541 io_ok = 1;
542 if (res != rdblksz) {
543 /*
544 * Record size changed. If this is happens on
545 * any record after the first, we probably have
546 * a tape drive which has a fixed record size
547 * we are getting multiple records in a single
548 * read). Watch out for record blocking that
549 * violates pax spec (must be a multiple of
550 * BLKMULT).
551 */
552 rdblksz = res;
553 if (rdblksz % BLKMULT)
554 invld_rec = 1;
555 }
556 return(res);
557 }
558 break;
559 case ISREG:
560 case ISBLK:
561 case ISCHR:
562 case ISPIPE:
563 default:
564 /*
565 * Files are so easy to deal with. These other things cannot
566 * be trusted at all. So when we are dealing with character
567 * devices and pipes we just take what they have ready for us
568 * and return. Trying to do anything else with them runs the
569 * risk of failure.
570 */
571 if ((res = read(arfd, buf, cnt)) > 0) {
572 io_ok = 1;
573 return(res);
574 }
575 break;
576 }
577
578 /*
579 * We are in trouble at this point, something is broken...
580 */
581 lstrval = res;
582 if (res < 0)
583 syswarn(1, errno, "Failed read on archive volume %d", arvol);
584 else
585 paxwarn(0, "End of archive volume %d reached", arvol);
586 return(res);
587 }
588
589 /*
590 * ar_write()
591 * Write a specified number of bytes in supplied buffer to the archive
592 * device so it appears as a single "block". Deals with errors and tries
593 * to recover when faced with short writes.
594 * Return:
595 * Number of bytes written. 0 indicates end of volume reached and with no
596 * flaws (as best that can be detected). A -1 indicates an unrecoverable
597 * error in the archive occurred.
598 */
599
600 int
ar_write(char * buf,int bsz)601 ar_write(char *buf, int bsz)
602 {
603 int res;
604 off_t cpos;
605
606 /*
607 * do not allow pax to create a "bad" archive. Once a write fails on
608 * an archive volume prevent further writes to it.
609 */
610 if (lstrval <= 0)
611 return(lstrval);
612
613 if ((res = write(arfd, buf, bsz)) == bsz) {
614 wr_trail = 1;
615 io_ok = 1;
616 return(bsz);
617 }
618 /*
619 * write broke, see what we can do with it. We try to send any partial
620 * writes that may violate pax spec to the next archive volume.
621 */
622 if (res < 0)
623 lstrval = res;
624 else
625 lstrval = 0;
626
627 switch (artyp) {
628 case ISREG:
629 if ((res > 0) && (res % BLKMULT)) {
630 /*
631 * try to fix up partial writes which are not BLKMULT
632 * in size by forcing the runt record to next archive
633 * volume
634 */
635 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
636 break;
637 cpos -= (off_t)res;
638 if (ftruncate(arfd, cpos) < 0)
639 break;
640 res = lstrval = 0;
641 break;
642 }
643 if (res >= 0)
644 break;
645 /*
646 * if file is out of space, handle it like a return of 0
647 */
648 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT))
649 res = lstrval = 0;
650 break;
651 case ISTAPE:
652 case ISCHR:
653 case ISBLK:
654 if (res >= 0)
655 break;
656 if (errno == EACCES) {
657 paxwarn(0, "Write failed, archive is write protected.");
658 res = lstrval = 0;
659 return(0);
660 }
661 /*
662 * see if we reached the end of media, if so force a change to
663 * the next volume
664 */
665 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO))
666 res = lstrval = 0;
667 break;
668 case ISPIPE:
669 default:
670 /*
671 * we cannot fix errors to these devices
672 */
673 break;
674 }
675
676 /*
677 * Better tell the user the bad news...
678 * if this is a block aligned archive format, we may have a bad archive
679 * if the format wants the header to start at a BLKMULT boundary. While
680 * we can deal with the mis-aligned data, it violates spec and other
681 * archive readers will likely fail. If the format is not block
682 * aligned, the user may be lucky (and the archive is ok).
683 */
684 if (res >= 0) {
685 if (res > 0)
686 wr_trail = 1;
687 io_ok = 1;
688 }
689
690 /*
691 * If we were trying to rewrite the trailer and it didn't work, we
692 * must quit right away.
693 */
694 if (!wr_trail && (res <= 0)) {
695 paxwarn(1,"Unable to append, trailer re-write failed. Quitting.");
696 return(res);
697 }
698
699 if (res == 0)
700 paxwarn(0, "End of archive volume %d reached", arvol);
701 else if (res < 0)
702 syswarn(1, errno, "Failed write to archive volume: %d", arvol);
703 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0))
704 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED");
705 else
706 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED");
707 return(res);
708 }
709
710 /*
711 * ar_rdsync()
712 * Try to move past a bad spot on a flawed archive as needed to continue
713 * I/O. Clears error flags to allow I/O to continue.
714 * Return:
715 * 0 when ok to try i/o again, -1 otherwise.
716 */
717
718 int
ar_rdsync(void)719 ar_rdsync(void)
720 {
721 long fsbz;
722 off_t cpos;
723 off_t mpos;
724 struct mtop mb;
725
726 /*
727 * Fail resync attempts at user request (done) or this is going to be
728 * an update/append to an existing archive. If last i/o hit media end,
729 * we need to go to the next volume not try a resync.
730 */
731 if ((done > 0) || (lstrval == 0))
732 return(-1);
733
734 if ((act == APPND) || (act == ARCHIVE)) {
735 paxwarn(1, "Cannot allow updates to an archive with flaws.");
736 return(-1);
737 }
738 if (io_ok)
739 did_io = 1;
740
741 switch(artyp) {
742 case ISTAPE:
743 /*
744 * if the last i/o was a successful data transfer, we assume
745 * the fault is just a bad record on the tape that we are now
746 * past. If we did not get any data since the last resync try
747 * to move the tape forward one PHYSICAL record past any
748 * damaged tape section. Some tape drives are stubborn and need
749 * to be pushed.
750 */
751 if (io_ok) {
752 io_ok = 0;
753 lstrval = 1;
754 break;
755 }
756 mb.mt_op = MTFSR;
757 mb.mt_count = 1;
758 if (ioctl(arfd, MTIOCTOP, &mb) < 0)
759 break;
760 lstrval = 1;
761 break;
762 case ISREG:
763 case ISCHR:
764 case ISBLK:
765 /*
766 * try to step over the bad part of the device.
767 */
768 io_ok = 0;
769 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG))
770 fsbz = BLKMULT;
771 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
772 break;
773 mpos = fsbz - (cpos % (off_t)fsbz);
774 if (lseek(arfd, mpos, SEEK_CUR) < 0)
775 break;
776 lstrval = 1;
777 break;
778 case ISPIPE:
779 default:
780 /*
781 * cannot recover on these archive device types
782 */
783 io_ok = 0;
784 break;
785 }
786 if (lstrval <= 0) {
787 paxwarn(1, "Unable to recover from an archive read failure.");
788 return(-1);
789 }
790 paxwarn(0, "Attempting to recover from an archive read failure.");
791 return(0);
792 }
793
794 /*
795 * ar_fow()
796 * Move the I/O position within the archive forward the specified number of
797 * bytes as supported by the device. If we cannot move the requested
798 * number of bytes, return the actual number of bytes moved in skipped.
799 * Return:
800 * 0 if moved the requested distance, -1 on complete failure, 1 on
801 * partial move (the amount moved is in skipped)
802 */
803
804 int
ar_fow(off_t sksz,off_t * skipped)805 ar_fow(off_t sksz, off_t *skipped)
806 {
807 off_t cpos;
808 off_t mpos;
809
810 *skipped = 0;
811 if (sksz <= 0)
812 return(0);
813
814 /*
815 * we cannot move forward at EOF or error
816 */
817 if (lstrval <= 0)
818 return(lstrval);
819
820 /*
821 * Safer to read forward on devices where it is hard to find the end of
822 * the media without reading to it. With tapes we cannot be sure of the
823 * number of physical blocks to skip (we do not know physical block
824 * size at this point), so we must only read forward on tapes!
825 */
826 if (artyp != ISREG)
827 return(0);
828
829 /*
830 * figure out where we are in the archive
831 */
832 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) {
833 /*
834 * we can be asked to move farther than there are bytes in this
835 * volume, if so, just go to file end and let normal buf_fill()
836 * deal with the end of file (it will go to next volume by
837 * itself)
838 */
839 if ((mpos = cpos + sksz) > arsb.st_size) {
840 *skipped = arsb.st_size - cpos;
841 mpos = arsb.st_size;
842 } else
843 *skipped = sksz;
844 if (lseek(arfd, mpos, SEEK_SET) >= 0)
845 return(0);
846 }
847 syswarn(1, errno, "Forward positioning operation on archive failed");
848 lstrval = -1;
849 return(-1);
850 }
851
852 /*
853 * ar_rev()
854 * move the i/o position within the archive backwards the specified byte
855 * count as supported by the device. With tapes drives we RESET rdblksz to
856 * the PHYSICAL blocksize.
857 * NOTE: We should only be called to move backwards so we can rewrite the
858 * last records (the trailer) of an archive (APPEND).
859 * Return:
860 * 0 if moved the requested distance, -1 on complete failure
861 */
862
863 int
ar_rev(off_t sksz)864 ar_rev(off_t sksz)
865 {
866 off_t cpos;
867 struct mtop mb;
868 int phyblk;
869
870 /*
871 * make sure we do not have try to reverse on a flawed archive
872 */
873 if (lstrval < 0)
874 return(lstrval);
875
876 switch(artyp) {
877 case ISPIPE:
878 if (sksz <= 0)
879 break;
880 /*
881 * cannot go backwards on these critters
882 */
883 paxwarn(1, "Reverse positioning on pipes is not supported.");
884 lstrval = -1;
885 return(-1);
886 case ISREG:
887 case ISBLK:
888 case ISCHR:
889 default:
890 if (sksz <= 0)
891 break;
892
893 /*
894 * For things other than files, backwards movement has a very
895 * high probability of failure as we really do not know the
896 * true attributes of the device we are talking to (the device
897 * may not even have the ability to lseek() in any direction).
898 * First we figure out where we are in the archive.
899 */
900 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) {
901 syswarn(1, errno,
902 "Unable to obtain current archive byte offset");
903 lstrval = -1;
904 return(-1);
905 }
906
907 /*
908 * we may try to go backwards past the start when the archive
909 * is only a single record. If this happens and we are on a
910 * multi volume archive, we need to go to the end of the
911 * previous volume and continue our movement backwards from
912 * there.
913 */
914 if ((cpos -= sksz) < (off_t)0L) {
915 if (arvol > 1) {
916 /*
917 * this should never happen
918 */
919 paxwarn(1,"Reverse position on previous volume.");
920 lstrval = -1;
921 return(-1);
922 }
923 cpos = (off_t)0L;
924 }
925 if (lseek(arfd, cpos, SEEK_SET) < 0) {
926 syswarn(1, errno, "Unable to seek archive backwards");
927 lstrval = -1;
928 return(-1);
929 }
930 break;
931 case ISTAPE:
932 /*
933 * Calculate and move the proper number of PHYSICAL tape
934 * blocks. If the sksz is not an even multiple of the physical
935 * tape size, we cannot do the move (this should never happen).
936 * (We also cannot handler trailers spread over two vols).
937 * get_phys() also makes sure we are in front of the filemark.
938 */
939 if ((phyblk = get_phys()) <= 0) {
940 lstrval = -1;
941 return(-1);
942 }
943
944 /*
945 * make sure future tape reads only go by physical tape block
946 * size (set rdblksz to the real size).
947 */
948 rdblksz = phyblk;
949
950 /*
951 * if no movement is required, just return (we must be after
952 * get_phys() so the physical blocksize is properly set)
953 */
954 if (sksz <= 0)
955 break;
956
957 /*
958 * ok we have to move. Make sure the tape drive can do it.
959 */
960 if (sksz % phyblk) {
961 paxwarn(1,
962 "Tape drive unable to backspace requested amount");
963 lstrval = -1;
964 return(-1);
965 }
966
967 /*
968 * move backwards the requested number of bytes
969 */
970 mb.mt_op = MTBSR;
971 mb.mt_count = sksz/phyblk;
972 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
973 syswarn(1,errno, "Unable to backspace tape %d blocks.",
974 mb.mt_count);
975 lstrval = -1;
976 return(-1);
977 }
978 break;
979 }
980 lstrval = 1;
981 return(0);
982 }
983
984 /*
985 * get_phys()
986 * Determine the physical block size on a tape drive. We need the physical
987 * block size so we know how many bytes we skip over when we move with
988 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when
989 * return.
990 * This is one really SLOW routine...
991 * Return:
992 * physical block size if ok (ok > 0), -1 otherwise
993 */
994
995 static int
get_phys(void)996 get_phys(void)
997 {
998 int padsz = 0;
999 int res;
1000 int phyblk;
1001 struct mtop mb;
1002 char scbuf[MAXBLK];
1003
1004 /*
1005 * move to the file mark, and then back up one record and read it.
1006 * this should tell us the physical record size the tape is using.
1007 */
1008 if (lstrval == 1) {
1009 /*
1010 * we know we are at file mark when we get back a 0 from
1011 * read()
1012 */
1013 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
1014 padsz += res;
1015 if (res < 0) {
1016 syswarn(1, errno, "Unable to locate tape filemark.");
1017 return(-1);
1018 }
1019 }
1020
1021 /*
1022 * move backwards over the file mark so we are at the end of the
1023 * last record.
1024 */
1025 mb.mt_op = MTBSF;
1026 mb.mt_count = 1;
1027 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1028 syswarn(1, errno, "Unable to backspace over tape filemark.");
1029 return(-1);
1030 }
1031
1032 /*
1033 * move backwards so we are in front of the last record and read it to
1034 * get physical tape blocksize.
1035 */
1036 mb.mt_op = MTBSR;
1037 mb.mt_count = 1;
1038 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1039 syswarn(1, errno, "Unable to backspace over last tape block.");
1040 return(-1);
1041 }
1042 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) {
1043 syswarn(1, errno, "Cannot determine archive tape blocksize.");
1044 return(-1);
1045 }
1046
1047 /*
1048 * read forward to the file mark, then back up in front of the filemark
1049 * (this is a bit paranoid, but should be safe to do).
1050 */
1051 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
1052 ;
1053 if (res < 0) {
1054 syswarn(1, errno, "Unable to locate tape filemark.");
1055 return(-1);
1056 }
1057 mb.mt_op = MTBSF;
1058 mb.mt_count = 1;
1059 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1060 syswarn(1, errno, "Unable to backspace over tape filemark.");
1061 return(-1);
1062 }
1063
1064 /*
1065 * set lstrval so we know that the filemark has not been seen
1066 */
1067 lstrval = 1;
1068
1069 /*
1070 * return if there was no padding
1071 */
1072 if (padsz == 0)
1073 return(phyblk);
1074
1075 /*
1076 * make sure we can move backwards over the padding. (this should
1077 * never fail).
1078 */
1079 if (padsz % phyblk) {
1080 paxwarn(1, "Tape drive unable to backspace requested amount");
1081 return(-1);
1082 }
1083
1084 /*
1085 * move backwards over the padding so the head is where it was when
1086 * we were first called (if required).
1087 */
1088 mb.mt_op = MTBSR;
1089 mb.mt_count = padsz/phyblk;
1090 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1091 syswarn(1,errno,"Unable to backspace tape over %d pad blocks",
1092 mb.mt_count);
1093 return(-1);
1094 }
1095 return(phyblk);
1096 }
1097
1098 /*
1099 * ar_next()
1100 * prompts the user for the next volume in this archive. For some devices
1101 * we may allow the media to be changed. Otherwise a new archive is
1102 * prompted for. By pax spec, if there is no controlling tty or an eof is
1103 * read on tty input, we must quit pax.
1104 * Return:
1105 * 0 when ready to continue, -1 when all done
1106 */
1107
1108 int
ar_next(void)1109 ar_next(void)
1110 {
1111 static char *arcbuf;
1112 char buf[PAXPATHLEN+2];
1113 sigset_t o_mask;
1114
1115 /*
1116 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so
1117 * things like writing EOF etc will be done) (Watch out ar_close() can
1118 * also be called via a signal handler, so we must prevent a race.
1119 */
1120 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0)
1121 syswarn(0, errno, "Unable to set signal mask");
1122 ar_close();
1123 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0)
1124 syswarn(0, errno, "Unable to restore signal mask");
1125
1126 if (done || !wr_trail || Oflag || strcmp(NM_TAR, argv0) == 0)
1127 return(-1);
1128
1129 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0);
1130
1131 /*
1132 * if i/o is on stdin or stdout, we cannot reopen it (we do not know
1133 * the name), the user will be forced to type it in.
1134 */
1135 if (strcmp(arcname, stdo) && strcmp(arcname, stdn) && (artyp != ISREG)
1136 && (artyp != ISPIPE)) {
1137 if (artyp == ISTAPE) {
1138 tty_prnt("%s ready for archive tape volume: %d\n",
1139 arcname, arvol);
1140 tty_prnt("Load the NEXT TAPE on the tape drive");
1141 } else {
1142 tty_prnt("%s ready for archive volume: %d\n",
1143 arcname, arvol);
1144 tty_prnt("Load the NEXT STORAGE MEDIA (if required)");
1145 }
1146
1147 if ((act == ARCHIVE) || (act == APPND))
1148 tty_prnt(" and make sure it is WRITE ENABLED.\n");
1149 else
1150 tty_prnt("\n");
1151
1152 for(;;) {
1153 tty_prnt("Type \"y\" to continue, \".\" to quit %s,",
1154 argv0);
1155 tty_prnt(" or \"s\" to switch to new device.\nIf you");
1156 tty_prnt(" cannot change storage media, type \"s\"\n");
1157 tty_prnt("Is the device ready and online? > ");
1158
1159 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){
1160 done = 1;
1161 lstrval = -1;
1162 tty_prnt("Quitting %s!\n", argv0);
1163 vfpart = 0;
1164 return(-1);
1165 }
1166
1167 if ((buf[0] == '\0') || (buf[1] != '\0')) {
1168 tty_prnt("%s unknown command, try again\n",buf);
1169 continue;
1170 }
1171
1172 switch (buf[0]) {
1173 case 'y':
1174 case 'Y':
1175 /*
1176 * we are to continue with the same device
1177 */
1178 if (ar_open(arcname) >= 0)
1179 return(0);
1180 tty_prnt("Cannot re-open %s, try again\n",
1181 arcname);
1182 continue;
1183 case 's':
1184 case 'S':
1185 /*
1186 * user wants to open a different device
1187 */
1188 tty_prnt("Switching to a different archive\n");
1189 break;
1190 default:
1191 tty_prnt("%s unknown command, try again\n",buf);
1192 continue;
1193 }
1194 break;
1195 }
1196 } else
1197 tty_prnt("Ready for archive volume: %d\n", arvol);
1198
1199 /*
1200 * have to go to a different archive
1201 */
1202 for (;;) {
1203 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0);
1204 tty_prnt("Archive name > ");
1205
1206 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) {
1207 done = 1;
1208 lstrval = -1;
1209 tty_prnt("Quitting %s!\n", argv0);
1210 vfpart = 0;
1211 return(-1);
1212 }
1213 if (buf[0] == '\0') {
1214 tty_prnt("Empty file name, try again\n");
1215 continue;
1216 }
1217 if (!strcmp(buf, "..")) {
1218 tty_prnt("Illegal file name: .. try again\n");
1219 continue;
1220 }
1221 if (strlen(buf) > PAXPATHLEN) {
1222 tty_prnt("File name too long, try again\n");
1223 continue;
1224 }
1225
1226 /*
1227 * try to open new archive
1228 */
1229 if (ar_open(buf) >= 0) {
1230 free(arcbuf);
1231 if ((arcbuf = strdup(buf)) == NULL) {
1232 done = 1;
1233 lstrval = -1;
1234 paxwarn(0, "Cannot save archive name.");
1235 return(-1);
1236 }
1237 arcname = arcbuf;
1238 break;
1239 }
1240 tty_prnt("Cannot open %s, try again\n", buf);
1241 continue;
1242 }
1243 return(0);
1244 }
1245
1246 /*
1247 * ar_start_gzip()
1248 * starts the gzip compression/decompression process as a child, using magic
1249 * to keep the fd the same in the calling function (parent).
1250 */
1251 void
ar_start_gzip(int fd,const char * gzip_prog,int wr)1252 ar_start_gzip(int fd, const char *gzip_prog, int wr)
1253 {
1254 int fds[2];
1255 const char *gzip_flags;
1256
1257 if (pipe(fds) < 0)
1258 err(1, "could not pipe");
1259 zpid = fork();
1260 if (zpid < 0)
1261 err(1, "could not fork");
1262
1263 /* parent */
1264 if (zpid) {
1265 if (wr)
1266 dup2(fds[1], fd);
1267 else
1268 dup2(fds[0], fd);
1269 close(fds[0]);
1270 close(fds[1]);
1271 } else {
1272 if (wr) {
1273 dup2(fds[0], STDIN_FILENO);
1274 dup2(fd, STDOUT_FILENO);
1275 gzip_flags = "-c";
1276 } else {
1277 dup2(fds[1], STDOUT_FILENO);
1278 dup2(fd, STDIN_FILENO);
1279 gzip_flags = "-dc";
1280 }
1281 close(fds[0]);
1282 close(fds[1]);
1283 if (execlp(gzip_prog, gzip_prog, gzip_flags,
1284 (char *)NULL) < 0)
1285 err(1, "could not exec");
1286 /* NOTREACHED */
1287 }
1288 }
1289