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[dragonfly.git] / bin / pax / ar_io.c
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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. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
1de703da
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36 *
37 * @(#)ar_io.c 8.2 (Berkeley) 4/18/94
38 * $FreeBSD: src/bin/pax/ar_io.c,v 1.12.2.1 2001/08/01 05:03:11 obrien Exp $
39 * $DragonFly: src/bin/pax/ar_io.c,v 1.2 2003/06/17 04:22:50 dillon Exp $
984263bc
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40 */
41
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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 <stdio.h>
52#include <string.h>
53#include <stdlib.h>
54#include <unistd.h>
55#include "pax.h"
56#include "options.h"
57#include "extern.h"
58
59/*
60 * Routines which deal directly with the archive I/O device/file.
61 */
62
63#define DMOD 0666 /* default mode of created archives */
64#define EXT_MODE O_RDONLY /* open mode for list/extract */
65#define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */
66#define APP_MODE O_RDWR /* mode for append */
67#define STDO "<STDOUT>" /* pseudo name for stdout */
68#define STDN "<STDIN>" /* pseudo name for stdin */
69static int arfd = -1; /* archive file descriptor */
70static int artyp = ISREG; /* archive type: file/FIFO/tape */
71static int arvol = 1; /* archive volume number */
72static int lstrval = -1; /* return value from last i/o */
73static int io_ok; /* i/o worked on volume after resync */
74static int did_io; /* did i/o ever occur on volume? */
75static int done; /* set via tty termination */
76static struct stat arsb; /* stat of archive device at open */
77static int invld_rec; /* tape has out of spec record size */
78static int wr_trail = 1; /* trailer was rewritten in append */
79static int can_unlnk = 0; /* do we unlink null archives? */
80char *arcname; /* printable name of archive */
81const char *gzip_program; /* name of gzip program */
82static pid_t zpid = -1; /* pid of child process */
83
84static int get_phys __P((void));
85extern sigset_t s_mask;
86static void ar_start_gzip __P((int, const char *, int));
87
88/*
89 * ar_open()
90 * Opens the next archive volume. Determines the type of the device and
91 * sets up block sizes as required by the archive device and the format.
92 * Note: we may be called with name == NULL on the first open only.
93 * Return:
94 * -1 on failure, 0 otherwise
95 */
96
97#ifdef __STDC__
98int
99ar_open(char *name)
100#else
101int
102ar_open(name)
103 char *name;
104#endif
105{
106 struct mtget mb;
107
108 if (arfd != -1)
109 (void)close(arfd);
110 arfd = -1;
111 can_unlnk = did_io = io_ok = invld_rec = 0;
112 artyp = ISREG;
113 flcnt = 0;
114
115 /*
116 * open based on overall operation mode
117 */
118 switch (act) {
119 case LIST:
120 case EXTRACT:
121 if (name == NULL) {
122 arfd = STDIN_FILENO;
123 arcname = STDN;
124 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0)
125 syswarn(0, errno, "Failed open to read on %s", name);
126 if (arfd != -1 && gzip_program != NULL)
127 ar_start_gzip(arfd, gzip_program, 0);
128 break;
129 case ARCHIVE:
130 if (name == NULL) {
131 arfd = STDOUT_FILENO;
132 arcname = STDO;
133 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0)
134 syswarn(0, errno, "Failed open to write on %s", name);
135 else
136 can_unlnk = 1;
137 if (arfd != -1 && gzip_program != NULL)
138 ar_start_gzip(arfd, gzip_program, 1);
139 break;
140 case APPND:
141 if (name == NULL) {
142 arfd = STDOUT_FILENO;
143 arcname = STDO;
144 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0)
145 syswarn(0, errno, "Failed open to read/write on %s",
146 name);
147 break;
148 case COPY:
149 /*
150 * arfd not used in COPY mode
151 */
152 arcname = "<NONE>";
153 lstrval = 1;
154 return(0);
155 }
156 if (arfd < 0)
157 return(-1);
158
159 if (chdname != NULL)
160 if (chdir(chdname) != 0)
161 syswarn(1, errno, "Failed chdir to %s", chdname);
162 /*
163 * set up is based on device type
164 */
165 if (fstat(arfd, &arsb) < 0) {
166 syswarn(0, errno, "Failed stat on %s", arcname);
167 (void)close(arfd);
168 arfd = -1;
169 can_unlnk = 0;
170 return(-1);
171 }
172 if (S_ISDIR(arsb.st_mode)) {
173 paxwarn(0, "Cannot write an archive on top of a directory %s",
174 arcname);
175 (void)close(arfd);
176 arfd = -1;
177 can_unlnk = 0;
178 return(-1);
179 }
180
181 if (S_ISCHR(arsb.st_mode))
182 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE;
183 else if (S_ISBLK(arsb.st_mode))
184 artyp = ISBLK;
185 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE))
186 artyp = ISPIPE;
187 else
188 artyp = ISREG;
189
190 /*
191 * make sure we beyond any doubt that we only can unlink regular files
192 * we created
193 */
194 if (artyp != ISREG)
195 can_unlnk = 0;
196 /*
197 * if we are writing, we are done
198 */
199 if (act == ARCHIVE) {
200 blksz = rdblksz = wrblksz;
201 lstrval = 1;
202 return(0);
203 }
204
205 /*
206 * set default blksz on read. APPNDs writes rdblksz on the last volume
207 * On all new archive volumes, we shift to wrblksz (if the user
208 * specified one, otherwize we will continue to use rdblksz). We
209 * must to set blocksize based on what kind of device the archive is
210 * stored.
211 */
212 switch(artyp) {
213 case ISTAPE:
214 /*
215 * Tape drives come in at least two flavors. Those that support
216 * variable sized records and those that have fixed sized
217 * records. They must be treated differently. For tape drives
218 * that support variable sized records, we must make large
219 * reads to make sure we get the entire record, otherwise we
220 * will just get the first part of the record (up to size we
221 * asked). Tapes with fixed sized records may or may not return
222 * multiple records in a single read. We really do not care
223 * what the physical record size is UNLESS we are going to
224 * append. (We will need the physical block size to rewrite
225 * the trailer). Only when we are appending do we go to the
226 * effort to figure out the true PHYSICAL record size.
227 */
228 blksz = rdblksz = MAXBLK;
229 break;
230 case ISPIPE:
231 case ISBLK:
232 case ISCHR:
233 /*
234 * Blocksize is not a major issue with these devices (but must
235 * be kept a multiple of 512). If the user specified a write
236 * block size, we use that to read. Under append, we must
237 * always keep blksz == rdblksz. Otherwise we go ahead and use
238 * the device optimal blocksize as (and if) returned by stat
239 * and if it is within pax specs.
240 */
241 if ((act == APPND) && wrblksz) {
242 blksz = rdblksz = wrblksz;
243 break;
244 }
245
246 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) &&
247 ((arsb.st_blksize % BLKMULT) == 0))
248 rdblksz = arsb.st_blksize;
249 else
250 rdblksz = DEVBLK;
251 /*
252 * For performance go for large reads when we can without harm
253 */
254 if ((act == APPND) || (artyp == ISCHR))
255 blksz = rdblksz;
256 else
257 blksz = MAXBLK;
258 break;
259 case ISREG:
260 /*
261 * if the user specified wrblksz works, use it. Under appends
262 * we must always keep blksz == rdblksz
263 */
264 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){
265 blksz = rdblksz = wrblksz;
266 break;
267 }
268 /*
269 * See if we can find the blocking factor from the file size
270 */
271 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT)
272 if ((arsb.st_size % rdblksz) == 0)
273 break;
274 /*
275 * When we cannot find a match, we may have a flawed archive.
276 */
277 if (rdblksz <= 0)
278 rdblksz = FILEBLK;
279 /*
280 * for performance go for large reads when we can
281 */
282 if (act == APPND)
283 blksz = rdblksz;
284 else
285 blksz = MAXBLK;
286 break;
287 default:
288 /*
289 * should never happen, worse case, slow...
290 */
291 blksz = rdblksz = BLKMULT;
292 break;
293 }
294 lstrval = 1;
295 return(0);
296}
297
298/*
299 * ar_close()
300 * closes archive device, increments volume number, and prints i/o summary
301 */
302#ifdef __STDC__
303void
304ar_close(void)
305#else
306void
307ar_close()
308#endif
309{
310
311 if (arfd < 0) {
312 did_io = io_ok = flcnt = 0;
313 return;
314 }
315
316 /*
317 * Close archive file. This may take a LONG while on tapes (we may be
318 * forced to wait for the rewind to complete) so tell the user what is
319 * going on (this avoids the user hitting control-c thinking pax is
320 * broken).
321 */
322 if (vflag && (artyp == ISTAPE)) {
323 if (vfpart)
324 (void)putc('\n', listf);
325 (void)fprintf(listf,
326 "%s: Waiting for tape drive close to complete...",
327 argv0);
328 (void)fflush(listf);
329 }
330
331 /*
332 * if nothing was written to the archive (and we created it), we remove
333 * it
334 */
335 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) &&
336 (arsb.st_size == 0)) {
337 (void)unlink(arcname);
338 can_unlnk = 0;
339 }
340
341 /*
342 * for a quick extract/list, pax frequently exits before the child
343 * process is done
344 */
345 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) {
346 int status;
347 kill(zpid, SIGINT);
348 waitpid(zpid, &status, 0);
349 }
350
351 (void)close(arfd);
352
353 if (vflag && (artyp == ISTAPE)) {
354 (void)fputs("done.\n", listf);
355 vfpart = 0;
356 (void)fflush(listf);
357 }
358 arfd = -1;
359
360 if (!io_ok && !did_io) {
361 flcnt = 0;
362 return;
363 }
364 did_io = io_ok = 0;
365
366 /*
367 * The volume number is only increased when the last device has data
368 * and we have already determined the archive format.
369 */
370 if (frmt != NULL)
371 ++arvol;
372
373 if (!vflag) {
374 flcnt = 0;
375 return;
376 }
377
378 /*
379 * Print out a summary of I/O for this archive volume.
380 */
381 if (vfpart) {
382 (void)putc('\n', listf);
383 vfpart = 0;
384 }
385
386 /*
387 * If we have not determined the format yet, we just say how many bytes
388 * we have skipped over looking for a header to id. there is no way we
389 * could have written anything yet.
390 */
391 if (frmt == NULL) {
392# ifdef NET2_STAT
393 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n",
394# else
395 (void)fprintf(listf, "%s: unknown format, %qu bytes skipped.\n",
396# endif
397 argv0, rdcnt);
398 (void)fflush(listf);
399 flcnt = 0;
400 return;
401 }
402
403 if (strcmp(NM_CPIO, argv0) == 0)
404 (void)fprintf(listf, "%qu blocks\n", (rdcnt ? rdcnt : wrcnt) / 5120);
405 else if (strcmp(NM_TAR, argv0) != 0)
406 (void)fprintf(listf,
407# ifdef NET2_STAT
408 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n",
409# else
410 "%s: %s vol %d, %lu files, %qu bytes read, %qu bytes written.\n",
411# endif
412 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt);
413 (void)fflush(listf);
414 flcnt = 0;
415}
416
417/*
418 * ar_drain()
419 * drain any archive format independent padding from an archive read
420 * from a socket or a pipe. This is to prevent the process on the
421 * other side of the pipe from getting a SIGPIPE (pax will stop
422 * reading an archive once a format dependent trailer is detected).
423 */
424#ifdef __STDC__
425void
426ar_drain(void)
427#else
428void
429ar_drain()
430#endif
431{
432 register int res;
433 char drbuf[MAXBLK];
434
435 /*
436 * we only drain from a pipe/socket. Other devices can be closed
437 * without reading up to end of file. We sure hope that pipe is closed
438 * on the other side so we will get an EOF.
439 */
440 if ((artyp != ISPIPE) || (lstrval <= 0))
441 return;
442
443 /*
444 * keep reading until pipe is drained
445 */
446 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0)
447 ;
448 lstrval = res;
449}
450
451/*
452 * ar_set_wr()
453 * Set up device right before switching from read to write in an append.
454 * device dependent code (if required) to do this should be added here.
455 * For all archive devices we are already positioned at the place we want
456 * to start writing when this routine is called.
457 * Return:
458 * 0 if all ready to write, -1 otherwise
459 */
460
461#ifdef __STDC__
462int
463ar_set_wr(void)
464#else
465int
466ar_set_wr()
467#endif
468{
469 off_t cpos;
470
471 /*
472 * we must make sure the trailer is rewritten on append, ar_next()
473 * will stop us if the archive containing the trailer was not written
474 */
475 wr_trail = 0;
476
477 /*
478 * Add any device dependent code as required here
479 */
480 if (artyp != ISREG)
481 return(0);
482 /*
483 * Ok we have an archive in a regular file. If we were rewriting a
484 * file, we must get rid of all the stuff after the current offset
485 * (it was not written by pax).
486 */
487 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) ||
488 (ftruncate(arfd, cpos) < 0)) {
489 syswarn(1, errno, "Unable to truncate archive file");
490 return(-1);
491 }
492 return(0);
493}
494
495/*
496 * ar_app_ok()
497 * check if the last volume in the archive allows appends. We cannot check
498 * this until we are ready to write since there is no spec that says all
499 * volumes in a single archive have to be of the same type...
500 * Return:
501 * 0 if we can append, -1 otherwise.
502 */
503
504#ifdef __STDC__
505int
506ar_app_ok(void)
507#else
508int
509ar_app_ok()
510#endif
511{
512 if (artyp == ISPIPE) {
513 paxwarn(1, "Cannot append to an archive obtained from a pipe.");
514 return(-1);
515 }
516
517 if (!invld_rec)
518 return(0);
519 paxwarn(1,"Cannot append, device record size %d does not support %s spec",
520 rdblksz, argv0);
521 return(-1);
522}
523
524/*
525 * ar_read()
526 * read up to a specified number of bytes from the archive into the
527 * supplied buffer. When dealing with tapes we may not always be able to
528 * read what we want.
529 * Return:
530 * Number of bytes in buffer. 0 for end of file, -1 for a read error.
531 */
532
533#ifdef __STDC__
534int
535ar_read(register char *buf, register int cnt)
536#else
537int
538ar_read(buf, cnt)
539 register char *buf;
540 register int cnt;
541#endif
542{
543 register int res = 0;
544
545 /*
546 * if last i/o was in error, no more reads until reset or new volume
547 */
548 if (lstrval <= 0)
549 return(lstrval);
550
551 /*
552 * how we read must be based on device type
553 */
554 switch (artyp) {
555 case ISTAPE:
556 if ((res = read(arfd, buf, cnt)) > 0) {
557 /*
558 * CAUTION: tape systems may not always return the same
559 * sized records so we leave blksz == MAXBLK. The
560 * physical record size that a tape drive supports is
561 * very hard to determine in a uniform and portable
562 * manner.
563 */
564 io_ok = 1;
565 if (res != rdblksz) {
566 /*
567 * Record size changed. If this is happens on
568 * any record after the first, we probably have
569 * a tape drive which has a fixed record size
570 * we are getting multiple records in a single
571 * read). Watch out for record blocking that
572 * violates pax spec (must be a multiple of
573 * BLKMULT).
574 */
575 rdblksz = res;
576 if (rdblksz % BLKMULT)
577 invld_rec = 1;
578 }
579 return(res);
580 }
581 break;
582 case ISREG:
583 case ISBLK:
584 case ISCHR:
585 case ISPIPE:
586 default:
587 /*
588 * Files are so easy to deal with. These other things cannot
589 * be trusted at all. So when we are dealing with character
590 * devices and pipes we just take what they have ready for us
591 * and return. Trying to do anything else with them runs the
592 * risk of failure.
593 */
594 if ((res = read(arfd, buf, cnt)) > 0) {
595 io_ok = 1;
596 return(res);
597 }
598 break;
599 }
600
601 /*
602 * We are in trouble at this point, something is broken...
603 */
604 lstrval = res;
605 if (res < 0)
606 syswarn(1, errno, "Failed read on archive volume %d", arvol);
607 else
608 paxwarn(0, "End of archive volume %d reached", arvol);
609 return(res);
610}
611
612/*
613 * ar_write()
614 * Write a specified number of bytes in supplied buffer to the archive
615 * device so it appears as a single "block". Deals with errors and tries
616 * to recover when faced with short writes.
617 * Return:
618 * Number of bytes written. 0 indicates end of volume reached and with no
619 * flaws (as best that can be detected). A -1 indicates an unrecoverable
620 * error in the archive occured.
621 */
622
623#ifdef __STDC__
624int
625ar_write(register char *buf, register int bsz)
626#else
627int
628ar_write(buf, bsz)
629 register char *buf;
630 register int bsz;
631#endif
632{
633 register int res;
634 off_t cpos;
635
636 /*
637 * do not allow pax to create a "bad" archive. Once a write fails on
638 * an archive volume prevent further writes to it.
639 */
640 if (lstrval <= 0)
641 return(lstrval);
642
643 if ((res = write(arfd, buf, bsz)) == bsz) {
644 wr_trail = 1;
645 io_ok = 1;
646 return(bsz);
647 }
648 /*
649 * write broke, see what we can do with it. We try to send any partial
650 * writes that may violate pax spec to the next archive volume.
651 */
652 if (res < 0)
653 lstrval = res;
654 else
655 lstrval = 0;
656
657 switch (artyp) {
658 case ISREG:
659 if ((res > 0) && (res % BLKMULT)) {
660 /*
661 * try to fix up partial writes which are not BLKMULT
662 * in size by forcing the runt record to next archive
663 * volume
664 */
665 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
666 break;
667 cpos -= (off_t)res;
668 if (ftruncate(arfd, cpos) < 0)
669 break;
670 res = lstrval = 0;
671 break;
672 }
673 if (res >= 0)
674 break;
675 /*
676 * if file is out of space, handle it like a return of 0
677 */
678 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT))
679 res = lstrval = 0;
680 break;
681 case ISTAPE:
682 case ISCHR:
683 case ISBLK:
684 if (res >= 0)
685 break;
686 if (errno == EACCES) {
687 paxwarn(0, "Write failed, archive is write protected.");
688 res = lstrval = 0;
689 return(0);
690 }
691 /*
692 * see if we reached the end of media, if so force a change to
693 * the next volume
694 */
695 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO))
696 res = lstrval = 0;
697 break;
698 case ISPIPE:
699 default:
700 /*
701 * we cannot fix errors to these devices
702 */
703 break;
704 }
705
706 /*
707 * Better tell the user the bad news...
708 * if this is a block aligned archive format, we may have a bad archive
709 * if the format wants the header to start at a BLKMULT boundary. While
710 * we can deal with the mis-aligned data, it violates spec and other
711 * archive readers will likely fail. if the format is not block
712 * aligned, the user may be lucky (and the archive is ok).
713 */
714 if (res >= 0) {
715 if (res > 0)
716 wr_trail = 1;
717 io_ok = 1;
718 }
719
720 /*
721 * If we were trying to rewrite the trailer and it didn't work, we
722 * must quit right away.
723 */
724 if (!wr_trail && (res <= 0)) {
725 paxwarn(1,"Unable to append, trailer re-write failed. Quitting.");
726 return(res);
727 }
728
729 if (res == 0)
730 paxwarn(0, "End of archive volume %d reached", arvol);
731 else if (res < 0)
732 syswarn(1, errno, "Failed write to archive volume: %d", arvol);
733 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0))
734 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED");
735 else
736 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED");
737 return(res);
738}
739
740/*
741 * ar_rdsync()
742 * Try to move past a bad spot on a flawed archive as needed to continue
743 * I/O. Clears error flags to allow I/O to continue.
744 * Return:
745 * 0 when ok to try i/o again, -1 otherwise.
746 */
747
748#ifdef __STDC__
749int
750ar_rdsync(void)
751#else
752int
753ar_rdsync()
754#endif
755{
756 long fsbz;
757 off_t cpos;
758 off_t mpos;
759 struct mtop mb;
760
761 /*
762 * Fail resync attempts at user request (done) or this is going to be
763 * an update/append to a existing archive. if last i/o hit media end,
764 * we need to go to the next volume not try a resync
765 */
766 if ((done > 0) || (lstrval == 0))
767 return(-1);
768
769 if ((act == APPND) || (act == ARCHIVE)) {
770 paxwarn(1, "Cannot allow updates to an archive with flaws.");
771 return(-1);
772 }
773 if (io_ok)
774 did_io = 1;
775
776 switch(artyp) {
777 case ISTAPE:
778 /*
779 * if the last i/o was a successful data transfer, we assume
780 * the fault is just a bad record on the tape that we are now
781 * past. If we did not get any data since the last resync try
782 * to move the tape forward one PHYSICAL record past any
783 * damaged tape section. Some tape drives are stubborn and need
784 * to be pushed.
785 */
786 if (io_ok) {
787 io_ok = 0;
788 lstrval = 1;
789 break;
790 }
791 mb.mt_op = MTFSR;
792 mb.mt_count = 1;
793 if (ioctl(arfd, MTIOCTOP, &mb) < 0)
794 break;
795 lstrval = 1;
796 break;
797 case ISREG:
798 case ISCHR:
799 case ISBLK:
800 /*
801 * try to step over the bad part of the device.
802 */
803 io_ok = 0;
804 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG))
805 fsbz = BLKMULT;
806 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
807 break;
808 mpos = fsbz - (cpos % (off_t)fsbz);
809 if (lseek(arfd, mpos, SEEK_CUR) < 0)
810 break;
811 lstrval = 1;
812 break;
813 case ISPIPE:
814 default:
815 /*
816 * cannot recover on these archive device types
817 */
818 io_ok = 0;
819 break;
820 }
821 if (lstrval <= 0) {
822 paxwarn(1, "Unable to recover from an archive read failure.");
823 return(-1);
824 }
825 paxwarn(0, "Attempting to recover from an archive read failure.");
826 return(0);
827}
828
829/*
830 * ar_fow()
831 * Move the I/O position within the archive foward the specified number of
832 * bytes as supported by the device. If we cannot move the requested
833 * number of bytes, return the actual number of bytes moved in skipped.
834 * Return:
835 * 0 if moved the requested distance, -1 on complete failure, 1 on
836 * partial move (the amount moved is in skipped)
837 */
838
839#ifdef __STDC__
840int
841ar_fow(off_t sksz, off_t *skipped)
842#else
843int
844ar_fow(sksz, skipped)
845 off_t sksz;
846 off_t *skipped;
847#endif
848{
849 off_t cpos;
850 off_t mpos;
851
852 *skipped = 0;
853 if (sksz <= 0)
854 return(0);
855
856 /*
857 * we cannot move foward at EOF or error
858 */
859 if (lstrval <= 0)
860 return(lstrval);
861
862 /*
863 * Safer to read forward on devices where it is hard to find the end of
864 * the media without reading to it. With tapes we cannot be sure of the
865 * number of physical blocks to skip (we do not know physical block
866 * size at this point), so we must only read foward on tapes!
867 */
868 if (artyp != ISREG)
869 return(0);
870
871 /*
872 * figure out where we are in the archive
873 */
874 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) {
875 /*
876 * we can be asked to move farther than there are bytes in this
877 * volume, if so, just go to file end and let normal buf_fill()
878 * deal with the end of file (it will go to next volume by
879 * itself)
880 */
881 if ((mpos = cpos + sksz) > arsb.st_size) {
882 *skipped = arsb.st_size - cpos;
883 mpos = arsb.st_size;
884 } else
885 *skipped = sksz;
886 if (lseek(arfd, mpos, SEEK_SET) >= 0)
887 return(0);
888 }
889 syswarn(1, errno, "Forward positioning operation on archive failed");
890 lstrval = -1;
891 return(-1);
892}
893
894/*
895 * ar_rev()
896 * move the i/o position within the archive backwards the specified byte
897 * count as supported by the device. With tapes drives we RESET rdblksz to
898 * the PHYSICAL blocksize.
899 * NOTE: We should only be called to move backwards so we can rewrite the
900 * last records (the trailer) of an archive (APPEND).
901 * Return:
902 * 0 if moved the requested distance, -1 on complete failure
903 */
904
905#ifdef __STDC__
906int
907ar_rev(off_t sksz)
908#else
909int
910ar_rev(sksz)
911 off_t sksz;
912#endif
913{
914 off_t cpos;
915 struct mtop mb;
916 register int phyblk;
917
918 /*
919 * make sure we do not have try to reverse on a flawed archive
920 */
921 if (lstrval < 0)
922 return(lstrval);
923
924 switch(artyp) {
925 case ISPIPE:
926 if (sksz <= 0)
927 break;
928 /*
929 * cannot go backwards on these critters
930 */
931 paxwarn(1, "Reverse positioning on pipes is not supported.");
932 lstrval = -1;
933 return(-1);
934 case ISREG:
935 case ISBLK:
936 case ISCHR:
937 default:
938 if (sksz <= 0)
939 break;
940
941 /*
942 * For things other than files, backwards movement has a very
943 * high probability of failure as we really do not know the
944 * true attributes of the device we are talking to (the device
945 * may not even have the ability to lseek() in any direction).
946 * First we figure out where we are in the archive.
947 */
948 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) {
949 syswarn(1, errno,
950 "Unable to obtain current archive byte offset");
951 lstrval = -1;
952 return(-1);
953 }
954
955 /*
956 * we may try to go backwards past the start when the archive
957 * is only a single record. If this hapens and we are on a
958 * multi volume archive, we need to go to the end of the
959 * previous volume and continue our movement backwards from
960 * there.
961 */
962 if ((cpos -= sksz) < (off_t)0L) {
963 if (arvol > 1) {
964 /*
965 * this should never happen
966 */
967 paxwarn(1,"Reverse position on previous volume.");
968 lstrval = -1;
969 return(-1);
970 }
971 cpos = (off_t)0L;
972 }
973 if (lseek(arfd, cpos, SEEK_SET) < 0) {
974 syswarn(1, errno, "Unable to seek archive backwards");
975 lstrval = -1;
976 return(-1);
977 }
978 break;
979 case ISTAPE:
980 /*
981 * Calculate and move the proper number of PHYSICAL tape
982 * blocks. If the sksz is not an even multiple of the physical
983 * tape size, we cannot do the move (this should never happen).
984 * (We also cannot handler trailers spread over two vols).
985 * get_phys() also makes sure we are in front of the filemark.
986 */
987 if ((phyblk = get_phys()) <= 0) {
988 lstrval = -1;
989 return(-1);
990 }
991
992 /*
993 * make sure future tape reads only go by physical tape block
994 * size (set rdblksz to the real size).
995 */
996 rdblksz = phyblk;
997
998 /*
999 * if no movement is required, just return (we must be after
1000 * get_phys() so the physical blocksize is properly set)
1001 */
1002 if (sksz <= 0)
1003 break;
1004
1005 /*
1006 * ok we have to move. Make sure the tape drive can do it.
1007 */
1008 if (sksz % phyblk) {
1009 paxwarn(1,
1010 "Tape drive unable to backspace requested amount");
1011 lstrval = -1;
1012 return(-1);
1013 }
1014
1015 /*
1016 * move backwards the requested number of bytes
1017 */
1018 mb.mt_op = MTBSR;
1019 mb.mt_count = sksz/phyblk;
1020 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1021 syswarn(1,errno, "Unable to backspace tape %d blocks.",
1022 mb.mt_count);
1023 lstrval = -1;
1024 return(-1);
1025 }
1026 break;
1027 }
1028 lstrval = 1;
1029 return(0);
1030}
1031
1032/*
1033 * get_phys()
1034 * Determine the physical block size on a tape drive. We need the physical
1035 * block size so we know how many bytes we skip over when we move with
1036 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when
1037 * return.
1038 * This is one really SLOW routine...
1039 * Return:
1040 * physical block size if ok (ok > 0), -1 otherwise
1041 */
1042
1043#ifdef __STDC__
1044static int
1045get_phys(void)
1046#else
1047static int
1048get_phys()
1049#endif
1050{
1051 register int padsz = 0;
1052 register int res;
1053 register int phyblk;
1054 struct mtop mb;
1055 char scbuf[MAXBLK];
1056
1057 /*
1058 * move to the file mark, and then back up one record and read it.
1059 * this should tell us the physical record size the tape is using.
1060 */
1061 if (lstrval == 1) {
1062 /*
1063 * we know we are at file mark when we get back a 0 from
1064 * read()
1065 */
1066 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
1067 padsz += res;
1068 if (res < 0) {
1069 syswarn(1, errno, "Unable to locate tape filemark.");
1070 return(-1);
1071 }
1072 }
1073
1074 /*
1075 * move backwards over the file mark so we are at the end of the
1076 * last record.
1077 */
1078 mb.mt_op = MTBSF;
1079 mb.mt_count = 1;
1080 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1081 syswarn(1, errno, "Unable to backspace over tape filemark.");
1082 return(-1);
1083 }
1084
1085 /*
1086 * move backwards so we are in front of the last record and read it to
1087 * get physical tape blocksize.
1088 */
1089 mb.mt_op = MTBSR;
1090 mb.mt_count = 1;
1091 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1092 syswarn(1, errno, "Unable to backspace over last tape block.");
1093 return(-1);
1094 }
1095 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) {
1096 syswarn(1, errno, "Cannot determine archive tape blocksize.");
1097 return(-1);
1098 }
1099
1100 /*
1101 * read foward to the file mark, then back up in front of the filemark
1102 * (this is a bit paranoid, but should be safe to do).
1103 */
1104 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
1105 ;
1106 if (res < 0) {
1107 syswarn(1, errno, "Unable to locate tape filemark.");
1108 return(-1);
1109 }
1110 mb.mt_op = MTBSF;
1111 mb.mt_count = 1;
1112 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1113 syswarn(1, errno, "Unable to backspace over tape filemark.");
1114 return(-1);
1115 }
1116
1117 /*
1118 * set lstrval so we know that the filemark has not been seen
1119 */
1120 lstrval = 1;
1121
1122 /*
1123 * return if there was no padding
1124 */
1125 if (padsz == 0)
1126 return(phyblk);
1127
1128 /*
1129 * make sure we can move backwards over the padding. (this should
1130 * never fail).
1131 */
1132 if (padsz % phyblk) {
1133 paxwarn(1, "Tape drive unable to backspace requested amount");
1134 return(-1);
1135 }
1136
1137 /*
1138 * move backwards over the padding so the head is where it was when
1139 * we were first called (if required).
1140 */
1141 mb.mt_op = MTBSR;
1142 mb.mt_count = padsz/phyblk;
1143 if (ioctl(arfd, MTIOCTOP, &mb) < 0) {
1144 syswarn(1,errno,"Unable to backspace tape over %d pad blocks",
1145 mb.mt_count);
1146 return(-1);
1147 }
1148 return(phyblk);
1149}
1150
1151/*
1152 * ar_next()
1153 * prompts the user for the next volume in this archive. For some devices
1154 * we may allow the media to be changed. Otherwise a new archive is
1155 * prompted for. By pax spec, if there is no controlling tty or an eof is
1156 * read on tty input, we must quit pax.
1157 * Return:
1158 * 0 when ready to continue, -1 when all done
1159 */
1160
1161#ifdef __STDC__
1162int
1163ar_next(void)
1164#else
1165int
1166ar_next()
1167#endif
1168{
1169 char buf[PAXPATHLEN+2];
1170 static int freeit = 0;
1171 sigset_t o_mask;
1172
1173 /*
1174 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so
1175 * things like writing EOF etc will be done) (Watch out ar_close() can
1176 * also be called via a signal handler, so we must prevent a race.
1177 */
1178 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0)
1179 syswarn(0, errno, "Unable to set signal mask");
1180 ar_close();
1181 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0)
1182 syswarn(0, errno, "Unable to restore signal mask");
1183
1184 if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0)
1185 return(-1);
1186
1187 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0);
1188
1189 /*
1190 * if i/o is on stdin or stdout, we cannot reopen it (we do not know
1191 * the name), the user will be forced to type it in.
1192 */
1193 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG)
1194 && (artyp != ISPIPE)) {
1195 if (artyp == ISTAPE) {
1196 tty_prnt("%s ready for archive tape volume: %d\n",
1197 arcname, arvol);
1198 tty_prnt("Load the NEXT TAPE on the tape drive");
1199 } else {
1200 tty_prnt("%s ready for archive volume: %d\n",
1201 arcname, arvol);
1202 tty_prnt("Load the NEXT STORAGE MEDIA (if required)");
1203 }
1204
1205 if ((act == ARCHIVE) || (act == APPND))
1206 tty_prnt(" and make sure it is WRITE ENABLED.\n");
1207 else
1208 tty_prnt("\n");
1209
1210 for(;;) {
1211 tty_prnt("Type \"y\" to continue, \".\" to quit %s,",
1212 argv0);
1213 tty_prnt(" or \"s\" to switch to new device.\nIf you");
1214 tty_prnt(" cannot change storage media, type \"s\"\n");
1215 tty_prnt("Is the device ready and online? > ");
1216
1217 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){
1218 done = 1;
1219 lstrval = -1;
1220 tty_prnt("Quitting %s!\n", argv0);
1221 vfpart = 0;
1222 return(-1);
1223 }
1224
1225 if ((buf[0] == '\0') || (buf[1] != '\0')) {
1226 tty_prnt("%s unknown command, try again\n",buf);
1227 continue;
1228 }
1229
1230 switch (buf[0]) {
1231 case 'y':
1232 case 'Y':
1233 /*
1234 * we are to continue with the same device
1235 */
1236 if (ar_open(arcname) >= 0)
1237 return(0);
1238 tty_prnt("Cannot re-open %s, try again\n",
1239 arcname);
1240 continue;
1241 case 's':
1242 case 'S':
1243 /*
1244 * user wants to open a different device
1245 */
1246 tty_prnt("Switching to a different archive\n");
1247 break;
1248 default:
1249 tty_prnt("%s unknown command, try again\n",buf);
1250 continue;
1251 }
1252 break;
1253 }
1254 } else
1255 tty_prnt("Ready for archive volume: %d\n", arvol);
1256
1257 /*
1258 * have to go to a different archive
1259 */
1260 for (;;) {
1261 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0);
1262 tty_prnt("Archive name > ");
1263
1264 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) {
1265 done = 1;
1266 lstrval = -1;
1267 tty_prnt("Quitting %s!\n", argv0);
1268 vfpart = 0;
1269 return(-1);
1270 }
1271 if (buf[0] == '\0') {
1272 tty_prnt("Empty file name, try again\n");
1273 continue;
1274 }
1275 if (!strcmp(buf, "..")) {
1276 tty_prnt("Illegal file name: .. try again\n");
1277 continue;
1278 }
1279 if (strlen(buf) > PAXPATHLEN) {
1280 tty_prnt("File name too long, try again\n");
1281 continue;
1282 }
1283
1284 /*
1285 * try to open new archive
1286 */
1287 if (ar_open(buf) >= 0) {
1288 if (freeit) {
1289 (void)free(arcname);
1290 freeit = 0;
1291 }
1292 if ((arcname = strdup(buf)) == NULL) {
1293 done = 1;
1294 lstrval = -1;
1295 paxwarn(0, "Cannot save archive name.");
1296 return(-1);
1297 }
1298 freeit = 1;
1299 break;
1300 }
1301 tty_prnt("Cannot open %s, try again\n", buf);
1302 continue;
1303 }
1304 return(0);
1305}
1306
1307/*
1308 * ar_start_gzip()
1309 * starts the gzip compression/decompression process as a child, using magic
1310 * to keep the fd the same in the calling function (parent).
1311 */
1312void
1313ar_start_gzip(int fd, const char *gzip_program, int wr)
1314{
1315 int fds[2];
1316 char *gzip_flags;
1317
1318 if (pipe(fds) < 0)
1319 err(1, "could not pipe");
1320 zpid = fork();
1321 if (zpid < 0)
1322 err(1, "could not fork");
1323
1324 /* parent */
1325 if (zpid) {
1326 if (wr)
1327 dup2(fds[1], fd);
1328 else
1329 dup2(fds[0], fd);
1330 close(fds[0]);
1331 close(fds[1]);
1332 } else {
1333 if (wr) {
1334 dup2(fds[0], STDIN_FILENO);
1335 dup2(fd, STDOUT_FILENO);
1336 gzip_flags = "-c";
1337 } else {
1338 dup2(fds[1], STDOUT_FILENO);
1339 dup2(fd, STDIN_FILENO);
1340 gzip_flags = "-dc";
1341 }
1342 close(fds[0]);
1343 close(fds[1]);
1344 if (execlp(gzip_program, gzip_program, gzip_flags,
1345 (char *)NULL) < 0)
1346 err(1, "could not exec");
1347 /* NOTREACHED */
1348 }
1349}