xref: /minix/bin/pax/ar_io.c (revision 0a6a1f1d)
1 /*	$NetBSD: ar_io.c,v 1.56 2015/03/09 23:38:08 sevan Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992 Keith Muller.
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Keith Muller of the University of California, San Diego.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if HAVE_NBTOOL_CONFIG_H
37 #include "nbtool_config.h"
38 #endif
39 
40 #include <sys/cdefs.h>
41 #if !defined(lint)
42 #if 0
43 static char sccsid[] = "@(#)ar_io.c	8.2 (Berkeley) 4/18/94";
44 #else
45 __RCSID("$NetBSD: ar_io.c,v 1.56 2015/03/09 23:38:08 sevan Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 #include <sys/param.h>
51 #include <sys/time.h>
52 #include <sys/stat.h>
53 #include <sys/ioctl.h>
54 #ifdef HAVE_SYS_MTIO_H
55 #include <sys/mtio.h>
56 #endif
57 #include <sys/wait.h>
58 #include <signal.h>
59 #include <string.h>
60 #include <fcntl.h>
61 #include <unistd.h>
62 #include <stdio.h>
63 #include <ctype.h>
64 #include <errno.h>
65 #include <stdlib.h>
66 #ifdef SUPPORT_RMT
67 #define __RMTLIB_PRIVATE
68 #include <rmt.h>
69 #endif /* SUPPORT_RMT */
70 #include "pax.h"
71 #include "options.h"
72 #include "extern.h"
73 
74 /*
75  * Routines which deal directly with the archive I/O device/file.
76  */
77 
78 #define DMOD		0666		/* default mode of created archives */
79 #define EXT_MODE	O_RDONLY	/* open mode for list/extract */
80 #define AR_MODE		(O_WRONLY | O_CREAT | O_TRUNC)	/* mode for archive */
81 #define APP_MODE	O_RDWR		/* mode for append */
82 static char STDO[] =	"<STDOUT>";	/* pseudo name for stdout */
83 static char STDN[] =	"<STDIN>";	/* pseudo name for stdin */
84 static char NONE[] =	"<NONE>";	/* pseudo name for none */
85 static int arfd = -1;			/* archive file descriptor */
86 static int artyp = ISREG;		/* archive type: file/FIFO/tape */
87 static int arvol = 1;			/* archive volume number */
88 static int lstrval = -1;		/* return value from last i/o */
89 static int io_ok;			/* i/o worked on volume after resync */
90 static int did_io;			/* did i/o ever occur on volume? */
91 static int done;			/* set via tty termination */
92 static struct stat arsb;		/* stat of archive device at open */
93 static int invld_rec;			/* tape has out of spec record size */
94 static int wr_trail = 1;		/* trailer was rewritten in append */
95 static int can_unlnk = 0;		/* do we unlink null archives?  */
96 const char *arcname;			/* printable name of archive */
97 const char *gzip_program;		/* name of gzip program */
98 static pid_t zpid = -1;			/* pid of child process */
99 time_t starttime;			/* time the run started */
100 int force_one_volume;			/* 1 if we ignore volume changes */
101 
102 #ifdef HAVE_SYS_MTIO_H
103 static int get_phys(void);
104 #endif
105 extern sigset_t s_mask;
106 static void ar_start_gzip(int, const char *, int);
107 static const char *timefmt(char *, size_t, off_t, time_t, const char *);
108 static const char *sizefmt(char *, size_t, off_t);
109 
110 #ifdef SUPPORT_RMT
111 #ifdef SYS_NO_RESTART
112 static int rmtread_with_restart(int, void *, int);
113 static int rmtwrite_with_restart(int, void *, int);
114 #else
115 #define rmtread_with_restart(a, b, c) rmtread((a), (b), (c))
116 #define rmtwrite_with_restart(a, b, c) rmtwrite((a), (b), (c))
117 #endif
118 #endif /* SUPPORT_RMT */
119 
120 /*
121  * ar_open()
122  *	Opens the next archive volume. Determines the type of the device and
123  *	sets up block sizes as required by the archive device and the format.
124  *	Note: we may be called with name == NULL on the first open only.
125  * Return:
126  *	-1 on failure, 0 otherwise
127  */
128 
129 int
ar_open(const char * name)130 ar_open(const char *name)
131 {
132 #ifdef HAVE_SYS_MTIO_H
133 	struct mtget mb;
134 #endif
135 
136 	if (arfd != -1)
137 		(void)close(arfd);
138 	arfd = -1;
139 	can_unlnk = did_io = io_ok = invld_rec = 0;
140 	artyp = ISREG;
141 	flcnt = 0;
142 
143 #ifdef SUPPORT_RMT
144 	if (name && strchr(name, ':') != NULL && !forcelocal) {
145 		artyp = ISRMT;
146 		if ((arfd = rmtopen(name, O_RDWR, DMOD)) == -1) {
147 			syswarn(0, errno, "Failed open on %s", name);
148 			return -1;
149 		}
150 		if (!isrmt(arfd)) {
151 			rmtclose(arfd);
152 			tty_warn(0, "Not a remote file: %s", name);
153 			return -1;
154 		}
155 		blksz = rdblksz = 8192;
156 		lstrval = 1;
157 		return 0;
158 	}
159 #endif /* SUPPORT_RMT */
160 
161 	/*
162 	 * open based on overall operation mode
163 	 */
164 	switch (act) {
165 	case LIST:
166 	case EXTRACT:
167 		if (name == NULL) {
168 			arfd = STDIN_FILENO;
169 			arcname = STDN;
170 		} else if ((arfd = open(name, EXT_MODE, DMOD)) < 0)
171 			syswarn(0, errno, "Failed open to read on %s", name);
172 		if (arfd != -1 && gzip_program != NULL)
173 			ar_start_gzip(arfd, gzip_program, 0);
174 		break;
175 	case ARCHIVE:
176 		if (name == NULL) {
177 			arfd = STDOUT_FILENO;
178 			arcname = STDO;
179 		} else if ((arfd = open(name, AR_MODE, DMOD)) < 0)
180 			syswarn(0, errno, "Failed open to write on %s", name);
181 		else
182 			can_unlnk = 1;
183 		if (arfd != -1 && gzip_program != NULL)
184 			ar_start_gzip(arfd, gzip_program, 1);
185 		break;
186 	case APPND:
187 		if (name == NULL) {
188 			arfd = STDOUT_FILENO;
189 			arcname = STDO;
190 		} else if ((arfd = open(name, APP_MODE, DMOD)) < 0)
191 			syswarn(0, errno, "Failed open to read/write on %s",
192 				name);
193 		break;
194 	case COPY:
195 		/*
196 		 * arfd not used in COPY mode
197 		 */
198 		arcname = NONE;
199 		lstrval = 1;
200 		return 0;
201 	}
202 	if (arfd < 0)
203 		return -1;
204 
205 	if (chdname != NULL)
206 		if (dochdir(chdname) == -1)
207 			return -1;
208 	/*
209 	 * set up is based on device type
210 	 */
211 	if (fstat(arfd, &arsb) < 0) {
212 		syswarn(0, errno, "Failed stat on %s", arcname);
213 		(void)close(arfd);
214 		arfd = -1;
215 		can_unlnk = 0;
216 		return -1;
217 	}
218 	if (S_ISDIR(arsb.st_mode)) {
219 		tty_warn(0, "Cannot write an archive on top of a directory %s",
220 		    arcname);
221 		(void)close(arfd);
222 		arfd = -1;
223 		can_unlnk = 0;
224 		return -1;
225 	}
226 
227 	if (S_ISCHR(arsb.st_mode)) {
228 #ifdef HAVE_SYS_MTIO_H
229 		artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE;
230 #else
231 		tty_warn(1, "System does not have tape support");
232 		artyp = ISREG;
233 #endif
234 	} else if (S_ISBLK(arsb.st_mode))
235 		artyp = ISBLK;
236 	else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE))
237 		artyp = ISPIPE;
238 	else
239 		artyp = ISREG;
240 
241 	/*
242 	 * Special handling for empty files.
243 	 */
244 	if (artyp == ISREG && arsb.st_size == 0) {
245 		switch (act) {
246 		case LIST:
247 		case EXTRACT:
248 			return -1;
249 		case APPND:
250 			act = -ARCHIVE;
251 			return -1;
252 		case ARCHIVE:
253 			break;
254 		}
255 	}
256 
257 	/*
258 	 * make sure beyond any doubt that we can unlink only regular files
259 	 * we created
260 	 */
261 	if (artyp != ISREG)
262 		can_unlnk = 0;
263 
264 	/*
265 	 * if we are writing, we are done
266 	 */
267 	if (act == ARCHIVE) {
268 		blksz = rdblksz = wrblksz;
269 		lstrval = 1;
270 		return 0;
271 	}
272 
273 	/*
274 	 * set default blksz on read. APPNDs writes rdblksz on the last volume
275 	 * On all new archive volumes, we shift to wrblksz (if the user
276 	 * specified one, otherwize we will continue to use rdblksz). We
277 	 * must set blocksize based on what kind of device the archive is
278 	 * stored.
279 	 */
280 	switch(artyp) {
281 	case ISTAPE:
282 		/*
283 		 * Tape drives come in at least two flavors. Those that support
284 		 * variable sized records and those that have fixed sized
285 		 * records. They must be treated differently. For tape drives
286 		 * that support variable sized records, we must make large
287 		 * reads to make sure we get the entire record, otherwise we
288 		 * will just get the first part of the record (up to size we
289 		 * asked). Tapes with fixed sized records may or may not return
290 		 * multiple records in a single read. We really do not care
291 		 * what the physical record size is UNLESS we are going to
292 		 * append. (We will need the physical block size to rewrite
293 		 * the trailer). Only when we are appending do we go to the
294 		 * effort to figure out the true PHYSICAL record size.
295 		 */
296 		blksz = rdblksz = MAXBLK;
297 		break;
298 	case ISPIPE:
299 	case ISBLK:
300 	case ISCHR:
301 		/*
302 		 * Blocksize is not a major issue with these devices (but must
303 		 * be kept a multiple of 512). If the user specified a write
304 		 * block size, we use that to read. Under append, we must
305 		 * always keep blksz == rdblksz. Otherwise we go ahead and use
306 		 * the device optimal blocksize as (and if) returned by stat
307 		 * and if it is within pax specs.
308 		 */
309 		if ((act == APPND) && wrblksz) {
310 			blksz = rdblksz = wrblksz;
311 			break;
312 		}
313 
314 		if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) &&
315 		    ((arsb.st_blksize % BLKMULT) == 0))
316 			rdblksz = arsb.st_blksize;
317 		else
318 			rdblksz = DEVBLK;
319 		/*
320 		 * For performance go for large reads when we can without harm
321 		 */
322 		if ((act == APPND) || (artyp == ISCHR))
323 			blksz = rdblksz;
324 		else
325 			blksz = MAXBLK;
326 		break;
327 	case ISREG:
328 		/*
329 		 * if the user specified wrblksz works, use it. Under appends
330 		 * we must always keep blksz == rdblksz
331 		 */
332 		if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){
333 			blksz = rdblksz = wrblksz;
334 			break;
335 		}
336 		/*
337 		 * See if we can find the blocking factor from the file size
338 		 */
339 		for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT)
340 			if ((arsb.st_size % rdblksz) == 0)
341 				break;
342 		/*
343 		 * When we cannot find a match, we may have a flawed archive.
344 		 */
345 		if (rdblksz <= 0)
346 			rdblksz = FILEBLK;
347 		/*
348 		 * for performance go for large reads when we can
349 		 */
350 		if (act == APPND)
351 			blksz = rdblksz;
352 		else
353 			blksz = MAXBLK;
354 		break;
355 	default:
356 		/*
357 		 * should never happen, worst case, slow...
358 		 */
359 		blksz = rdblksz = BLKMULT;
360 		break;
361 	}
362 	lstrval = 1;
363 	return 0;
364 }
365 
366 /*
367  * ar_close()
368  *	closes archive device, increments volume number, and prints i/o summary
369  */
370 void
ar_close(void)371 ar_close(void)
372 {
373 	int status;
374 
375 	if (arfd < 0) {
376 		did_io = io_ok = flcnt = 0;
377 		return;
378 	}
379 
380 
381 	/*
382 	 * Close archive file. This may take a LONG while on tapes (we may be
383 	 * forced to wait for the rewind to complete) so tell the user what is
384 	 * going on (this avoids the user hitting control-c thinking pax is
385 	 * broken).
386 	 */
387 	if ((vflag || Vflag) && (artyp == ISTAPE)) {
388 		if (vfpart)
389 			(void)putc('\n', listf);
390 		(void)fprintf(listf,
391 			"%s: Waiting for tape drive close to complete...",
392 			argv0);
393 		(void)fflush(listf);
394 	}
395 
396 	/*
397 	 * if nothing was written to the archive (and we created it), we remove
398 	 * it
399 	 */
400 	if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) &&
401 	    (arsb.st_size == 0)) {
402 		(void)unlink(arcname);
403 		can_unlnk = 0;
404 	}
405 
406 	/*
407 	 * for a quick extract/list, pax frequently exits before the child
408 	 * process is done
409 	 */
410 	if ((act == LIST || act == EXTRACT) && nflag && zpid > 0)
411 		kill(zpid, SIGINT);
412 
413 #ifdef SUPPORT_RMT
414 	if (artyp == ISRMT)
415 		(void)rmtclose(arfd);
416 	else
417 #endif /* SUPPORT_RMT */
418 		(void)close(arfd);
419 
420 	/* Do not exit before child to ensure data integrity */
421 	if (zpid > 0)
422 		waitpid(zpid, &status, 0);
423 
424 	if ((vflag || Vflag) && (artyp == ISTAPE)) {
425 		(void)fputs("done.\n", listf);
426 		vfpart = 0;
427 		(void)fflush(listf);
428 	}
429 	arfd = -1;
430 
431 	if (!io_ok && !did_io) {
432 		flcnt = 0;
433 		return;
434 	}
435 	did_io = io_ok = 0;
436 
437 	/*
438 	 * The volume number is only increased when the last device has data
439 	 * and we have already determined the archive format.
440 	 */
441 	if (frmt != NULL)
442 		++arvol;
443 
444 	if (!vflag && !Vflag) {
445 		flcnt = 0;
446 		return;
447 	}
448 
449 	/*
450 	 * Print out a summary of I/O for this archive volume.
451 	 */
452 	if (vfpart) {
453 		(void)putc('\n', listf);
454 		vfpart = 0;
455 	}
456 
457 	/* mimic cpio's block count first */
458 	if (frmt && strcmp(NM_CPIO, argv0) == 0) {
459 		(void)fprintf(listf, OFFT_F " blocks\n",
460 		    (rdcnt ? rdcnt : wrcnt) / 5120);
461 	}
462 
463 	ar_summary(0);
464 
465 	(void)fflush(listf);
466 	flcnt = 0;
467 }
468 
469 /*
470  * ar_drain()
471  *	drain any archive format independent padding from an archive read
472  *	from a socket or a pipe. This is to prevent the process on the
473  *	other side of the pipe from getting a SIGPIPE (pax will stop
474  *	reading an archive once a format dependent trailer is detected).
475  */
476 void
ar_drain(void)477 ar_drain(void)
478 {
479 	int res;
480 	char drbuf[MAXBLK];
481 
482 	/*
483 	 * we only drain from a pipe/socket. Other devices can be closed
484 	 * without reading up to end of file. We sure hope that pipe is closed
485 	 * on the other side so we will get an EOF.
486 	 */
487 	if ((artyp != ISPIPE) || (lstrval <= 0))
488 		return;
489 
490 	/*
491 	 * keep reading until pipe is drained
492 	 */
493 #ifdef SUPPORT_RMT
494 	if (artyp == ISRMT) {
495 		while ((res = rmtread_with_restart(arfd,
496 						   drbuf, sizeof(drbuf))) > 0)
497 			continue;
498 	} else {
499 #endif /* SUPPORT_RMT */
500 		while ((res = read_with_restart(arfd,
501 						drbuf, sizeof(drbuf))) > 0)
502 			continue;
503 #ifdef SUPPORT_RMT
504 	}
505 #endif /* SUPPORT_RMT */
506 	lstrval = res;
507 }
508 
509 /*
510  * ar_set_wr()
511  *	Set up device right before switching from read to write in an append.
512  *	device dependent code (if required) to do this should be added here.
513  *	For all archive devices we are already positioned at the place we want
514  *	to start writing when this routine is called.
515  * Return:
516  *	0 if all ready to write, -1 otherwise
517  */
518 
519 int
ar_set_wr(void)520 ar_set_wr(void)
521 {
522 	off_t cpos;
523 
524 	/*
525 	 * we must make sure the trailer is rewritten on append, ar_next()
526 	 * will stop us if the archive containing the trailer was not written
527 	 */
528 	wr_trail = 0;
529 
530 	/*
531 	 * Add any device dependent code as required here
532 	 */
533 	if (artyp != ISREG)
534 		return 0;
535 	/*
536 	 * Ok we have an archive in a regular file. If we were rewriting a
537 	 * file, we must get rid of all the stuff after the current offset
538 	 * (it was not written by pax).
539 	 */
540 	if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) ||
541 	    (ftruncate(arfd, cpos) < 0)) {
542 		syswarn(1, errno, "Unable to truncate archive file");
543 		return -1;
544 	}
545 	return 0;
546 }
547 
548 /*
549  * ar_app_ok()
550  *	check if the last volume in the archive allows appends. We cannot check
551  *	this until we are ready to write since there is no spec that says all
552  *	volumes in a single archive have to be of the same type...
553  * Return:
554  *	0 if we can append, -1 otherwise.
555  */
556 
557 int
ar_app_ok(void)558 ar_app_ok(void)
559 {
560 	if (artyp == ISPIPE) {
561 		tty_warn(1,
562 		    "Cannot append to an archive obtained from a pipe.");
563 		return -1;
564 	}
565 
566 	if (!invld_rec)
567 		return 0;
568 	tty_warn(1,
569 	    "Cannot append, device record size %d does not support %s spec",
570 	    rdblksz, argv0);
571 	return -1;
572 }
573 
574 #ifdef SYS_NO_RESTART
575 /*
576  * read_with_restart()
577  *	Equivalent to read() but does retry on signals.
578  *	This function is not needed on 4.2BSD and later.
579  * Return:
580  *	Number of bytes written.  -1 indicates an error.
581  */
582 
583 int
read_with_restart(int fd,void * buf,int bsz)584 read_with_restart(int fd, void *buf, int bsz)
585 {
586 	int r;
587 
588 	while (((r = read(fd, buf, bsz)) < 0) && errno == EINTR)
589 		continue;
590 
591 	return r;
592 }
593 
594 /*
595  * rmtread_with_restart()
596  *	Equivalent to rmtread() but does retry on signals.
597  *	This function is not needed on 4.2BSD and later.
598  * Return:
599  *	Number of bytes written.  -1 indicates an error.
600  */
601 static int
rmtread_with_restart(int fd,void * buf,int bsz)602 rmtread_with_restart(int fd, void *buf, int bsz)
603 {
604 	int r;
605 
606 	while (((r = rmtread(fd, buf, bsz)) < 0) && errno == EINTR)
607 		continue;
608 
609 	return r;
610 }
611 #endif
612 
613 /*
614  * xread()
615  *	Equivalent to read() but does retry on partial read, which may occur
616  *	on signals.
617  * Return:
618  *	Number of bytes read.  0 for end of file, -1 for an error.
619  */
620 
621 int
xread(int fd,void * buf,int bsz)622 xread(int fd, void *buf, int bsz)
623 {
624 	char *b = buf;
625 	int nread = 0;
626 	int r;
627 
628 	do {
629 #ifdef SUPPORT_RMT
630 		if ((r = rmtread_with_restart(fd, b, bsz)) <= 0)
631 			break;
632 #else
633 		if ((r = read_with_restart(fd, b, bsz)) <= 0)
634 			break;
635 #endif /* SUPPORT_RMT */
636 		b += r;
637 		bsz -= r;
638 		nread += r;
639 	} while (bsz > 0);
640 
641 	return nread ? nread : r;
642 }
643 
644 #ifdef SYS_NO_RESTART
645 /*
646  * write_with_restart()
647  *	Equivalent to write() but does retry on signals.
648  *	This function is not needed on 4.2BSD and later.
649  * Return:
650  *	Number of bytes written.  -1 indicates an error.
651  */
652 
653 int
write_with_restart(int fd,void * buf,int bsz)654 write_with_restart(int fd, void *buf, int bsz)
655 {
656 	int r;
657 
658 	while (((r = write(fd, buf, bsz)) < 0) && errno == EINTR)
659 		;
660 
661 	return r;
662 }
663 
664 /*
665  * rmtwrite_with_restart()
666  *	Equivalent to write() but does retry on signals.
667  *	This function is not needed on 4.2BSD and later.
668  * Return:
669  *	Number of bytes written.  -1 indicates an error.
670  */
671 
672 static int
rmtwrite_with_restart(int fd,void * buf,int bsz)673 rmtwrite_with_restart(int fd, void *buf, int bsz)
674 {
675 	int r;
676 
677 	while (((r = rmtwrite(fd, buf, bsz)) < 0) && errno == EINTR)
678 		;
679 
680 	return r;
681 }
682 #endif
683 
684 /*
685  * xwrite()
686  *	Equivalent to write() but does retry on partial write, which may occur
687  *	on signals.
688  * Return:
689  *	Number of bytes written.  -1 indicates an error.
690  */
691 
692 int
xwrite(int fd,void * buf,int bsz)693 xwrite(int fd, void *buf, int bsz)
694 {
695 	char *b = buf;
696 	int written = 0;
697 	int r;
698 
699 	do {
700 #ifdef SUPPORT_RMT
701 		if ((r = rmtwrite_with_restart(fd, b, bsz)) <= 0)
702 			break;
703 #else
704 		if ((r = write_with_restart(fd, b, bsz)) <= 0)
705 			break;
706 #endif /* SUPPORT_RMT */
707 		b += r;
708 		bsz -= r;
709 		written += r;
710 	} while (bsz > 0);
711 
712 	return written ? written : r;
713 }
714 
715 /*
716  * ar_read()
717  *	read up to a specified number of bytes from the archive into the
718  *	supplied buffer. When dealing with tapes we may not always be able to
719  *	read what we want.
720  * Return:
721  *	Number of bytes in buffer. 0 for end of file, -1 for a read error.
722  */
723 
724 int
ar_read(char * buf,int cnt)725 ar_read(char *buf, int cnt)
726 {
727 	int res = 0;
728 
729 	/*
730 	 * if last i/o was in error, no more reads until reset or new volume
731 	 */
732 	if (lstrval <= 0)
733 		return lstrval;
734 
735 	/*
736 	 * how we read must be based on device type
737 	 */
738 	switch (artyp) {
739 #ifdef SUPPORT_RMT
740 	case ISRMT:
741 		if ((res = rmtread_with_restart(arfd, buf, cnt)) > 0) {
742 			io_ok = 1;
743 			return res;
744 		}
745 		break;
746 #endif /* SUPPORT_RMT */
747 	case ISTAPE:
748 		if ((res = read_with_restart(arfd, buf, cnt)) > 0) {
749 			/*
750 			 * CAUTION: tape systems may not always return the same
751 			 * sized records so we leave blksz == MAXBLK. The
752 			 * physical record size that a tape drive supports is
753 			 * very hard to determine in a uniform and portable
754 			 * manner.
755 			 */
756 			io_ok = 1;
757 			if (res != rdblksz) {
758 				/*
759 				 * Record size changed. If this happens on
760 				 * any record after the first, we probably have
761 				 * a tape drive which has a fixed record size
762 				 * (we are getting multiple records in a single
763 				 * read). Watch out for record blocking that
764 				 * violates pax spec (must be a multiple of
765 				 * BLKMULT).
766 				 */
767 				rdblksz = res;
768 				if (rdblksz % BLKMULT)
769 					invld_rec = 1;
770 			}
771 			return res;
772 		}
773 		break;
774 	case ISREG:
775 	case ISBLK:
776 	case ISCHR:
777 	case ISPIPE:
778 	default:
779 		/*
780 		 * Files are so easy to deal with. These other things cannot
781 		 * be trusted at all. So when we are dealing with character
782 		 * devices and pipes we just take what they have ready for us
783 		 * and return. Trying to do anything else with them runs the
784 		 * risk of failure.
785 		 */
786 		if ((res = read_with_restart(arfd, buf, cnt)) > 0) {
787 			io_ok = 1;
788 			return res;
789 		}
790 		break;
791 	}
792 
793 	/*
794 	 * We are in trouble at this point, something is broken...
795 	 */
796 	lstrval = res;
797 	if (res < 0)
798 		syswarn(1, errno, "Failed read on archive volume %d", arvol);
799 	else
800 		tty_warn(0, "End of archive volume %d reached", arvol);
801 	return res;
802 }
803 
804 /*
805  * ar_write()
806  *	Write a specified number of bytes in supplied buffer to the archive
807  *	device so it appears as a single "block". Deals with errors and tries
808  *	to recover when faced with short writes.
809  * Return:
810  *	Number of bytes written. 0 indicates end of volume reached and with no
811  *	flaws (as best that can be detected). A -1 indicates an unrecoverable
812  *	error in the archive occurred.
813  */
814 
815 int
ar_write(char * buf,int bsz)816 ar_write(char *buf, int bsz)
817 {
818 	int res;
819 	off_t cpos;
820 
821 	/*
822 	 * do not allow pax to create a "bad" archive. Once a write fails on
823 	 * an archive volume prevent further writes to it.
824 	 */
825 	if (lstrval <= 0)
826 		return lstrval;
827 
828 	if ((res = xwrite(arfd, buf, bsz)) == bsz) {
829 		wr_trail = 1;
830 		io_ok = 1;
831 		return bsz;
832 	}
833 	/*
834 	 * write broke, see what we can do with it. We try to send any partial
835 	 * writes that may violate pax spec to the next archive volume.
836 	 */
837 	if (res < 0)
838 		lstrval = res;
839 	else
840 		lstrval = 0;
841 
842 	switch (artyp) {
843 	case ISREG:
844 		if ((res > 0) && (res % BLKMULT)) {
845 			/*
846 			 * try to fix up partial writes which are not BLKMULT
847 			 * in size by forcing the runt record to next archive
848 			 * volume
849 			 */
850 			if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
851 				break;
852 			cpos -= (off_t)res;
853 			if (ftruncate(arfd, cpos) < 0)
854 				break;
855 			res = lstrval = 0;
856 			break;
857 		}
858 		if (res >= 0)
859 			break;
860 		/*
861 		 * if file is out of space, handle it like a return of 0
862 		 */
863 		if ((errno == ENOSPC) || (errno == EFBIG))
864 			res = lstrval = 0;
865 #ifdef EDQUOT
866 		if (errno == EDQUOT)
867 			res = lstrval = 0;
868 #endif
869 		break;
870 	case ISTAPE:
871 	case ISCHR:
872 	case ISBLK:
873 #ifdef SUPPORT_RMT
874 	case ISRMT:
875 #endif /* SUPPORT_RMT */
876 		if (res >= 0)
877 			break;
878 		if (errno == EACCES) {
879 			tty_warn(0,
880 			    "Write failed, archive is write protected.");
881 			res = lstrval = 0;
882 			return 0;
883 		}
884 		/*
885 		 * see if we reached the end of media, if so force a change to
886 		 * the next volume
887 		 */
888 		if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO))
889 			res = lstrval = 0;
890 		break;
891 	case ISPIPE:
892 	default:
893 		/*
894 		 * we cannot fix errors to these devices
895 		 */
896 		break;
897 	}
898 
899 	/*
900 	 * Better tell the user the bad news...
901 	 * if this is a block aligned archive format, we may have a bad archive
902 	 * if the format wants the header to start at a BLKMULT boundary. While
903 	 * we can deal with the mis-aligned data, it violates spec and other
904 	 * archive readers will likely fail. if the format is not block
905 	 * aligned, the user may be lucky (and the archive is ok).
906 	 */
907 	if (res >= 0) {
908 		if (res > 0)
909 			wr_trail = 1;
910 		io_ok = 1;
911 	}
912 
913 	/*
914 	 * If we were trying to rewrite the trailer and it didn't work, we
915 	 * must quit right away.
916 	 */
917 	if (!wr_trail && (res <= 0)) {
918 		tty_warn(1,
919 		    "Unable to append, trailer re-write failed. Quitting.");
920 		return res;
921 	}
922 
923 	if (res == 0)
924 		tty_warn(0, "End of archive volume %d reached", arvol);
925 	else if (res < 0)
926 		syswarn(1, errno, "Failed write to archive volume: %d", arvol);
927 	else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0))
928 		tty_warn(0,
929 		    "WARNING: partial archive write. Archive MAY BE FLAWED");
930 	else
931 		tty_warn(1,"WARNING: partial archive write. Archive IS FLAWED");
932 	return res;
933 }
934 
935 /*
936  * ar_rdsync()
937  *	Try to move past a bad spot on a flawed archive as needed to continue
938  *	I/O. Clears error flags to allow I/O to continue.
939  * Return:
940  *	0 when ok to try i/o again, -1 otherwise.
941  */
942 
943 int
ar_rdsync(void)944 ar_rdsync(void)
945 {
946 	long fsbz;
947 	off_t cpos;
948 	off_t mpos;
949 #ifdef HAVE_SYS_MTIO_H
950 	struct mtop mb;
951 #endif
952 
953 	/*
954 	 * Fail resync attempts at user request (done) or if this is going to be
955 	 * an update/append to a existing archive. if last i/o hit media end,
956 	 * we need to go to the next volume not try a resync
957 	 */
958 	if ((done > 0) || (lstrval == 0))
959 		return -1;
960 
961 	if ((act == APPND) || (act == ARCHIVE)) {
962 		tty_warn(1, "Cannot allow updates to an archive with flaws.");
963 		return -1;
964 	}
965 	if (io_ok)
966 		did_io = 1;
967 
968 	switch(artyp) {
969 #ifdef SUPPORT_RMT
970 	case ISRMT:
971 #endif /* SUPPORT_RMT */
972 	case ISTAPE:
973 #ifdef HAVE_SYS_MTIO_H
974 		/*
975 		 * if the last i/o was a successful data transfer, we assume
976 		 * the fault is just a bad record on the tape that we are now
977 		 * past. If we did not get any data since the last resync try
978 		 * to move the tape forward one PHYSICAL record past any
979 		 * damaged tape section. Some tape drives are stubborn and need
980 		 * to be pushed.
981 		 */
982 		if (io_ok) {
983 			io_ok = 0;
984 			lstrval = 1;
985 			break;
986 		}
987 		mb.mt_op = MTFSR;
988 		mb.mt_count = 1;
989 #ifdef SUPPORT_RMT
990 		if (artyp == ISRMT) {
991 			if (rmtioctl(arfd, MTIOCTOP, &mb) < 0)
992 				break;
993 		} else {
994 #endif /* SUPPORT_RMT */
995 			if (ioctl(arfd, MTIOCTOP, &mb) < 0)
996 				break;
997 #ifdef SUPPORT_RMT
998 		}
999 #endif /* SUPPORT_RMT */
1000 		lstrval = 1;
1001 #else
1002 		tty_warn(1, "System does not have tape support");
1003 #endif
1004 		break;
1005 	case ISREG:
1006 	case ISCHR:
1007 	case ISBLK:
1008 		/*
1009 		 * try to step over the bad part of the device.
1010 		 */
1011 		io_ok = 0;
1012 		if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG))
1013 			fsbz = BLKMULT;
1014 		if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0)
1015 			break;
1016 		mpos = fsbz - (cpos % (off_t)fsbz);
1017 		if (lseek(arfd, mpos, SEEK_CUR) < 0)
1018 			break;
1019 		lstrval = 1;
1020 		break;
1021 	case ISPIPE:
1022 	default:
1023 		/*
1024 		 * cannot recover on these archive device types
1025 		 */
1026 		io_ok = 0;
1027 		break;
1028 	}
1029 	if (lstrval <= 0) {
1030 		tty_warn(1, "Unable to recover from an archive read failure.");
1031 		return -1;
1032 	}
1033 	tty_warn(0, "Attempting to recover from an archive read failure.");
1034 	return 0;
1035 }
1036 
1037 /*
1038  * ar_fow()
1039  *	Move the I/O position within the archive forward the specified number of
1040  *	bytes as supported by the device. If we cannot move the requested
1041  *	number of bytes, return the actual number of bytes moved in skipped.
1042  * Return:
1043  *	0 if moved the requested distance, -1 on complete failure, 1 on
1044  *	partial move (the amount moved is in skipped)
1045  */
1046 
1047 int
ar_fow(off_t sksz,off_t * skipped)1048 ar_fow(off_t sksz, off_t *skipped)
1049 {
1050 	off_t cpos;
1051 	off_t mpos;
1052 
1053 	*skipped = 0;
1054 	if (sksz <= 0)
1055 		return 0;
1056 
1057 	/*
1058 	 * we cannot move forward at EOF or error
1059 	 */
1060 	if (lstrval <= 0)
1061 		return lstrval;
1062 
1063 	/*
1064 	 * Safer to read forward on devices where it is hard to find the end of
1065 	 * the media without reading to it. With tapes we cannot be sure of the
1066 	 * number of physical blocks to skip (we do not know physical block
1067 	 * size at this point), so we must only read forward on tapes!
1068 	 */
1069 	if (artyp == ISTAPE || artyp == ISPIPE
1070 #ifdef SUPPORT_RMT
1071 	    || artyp == ISRMT
1072 #endif /* SUPPORT_RMT */
1073 	    )
1074 		return 0;
1075 
1076 	/*
1077 	 * figure out where we are in the archive
1078 	 */
1079 	if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) {
1080 		/*
1081 		 * we can be asked to move farther than there are bytes in this
1082 		 * volume, if so, just go to file end and let normal buf_fill()
1083 		 * deal with the end of file (it will go to next volume by
1084 		 * itself)
1085 		 */
1086 		mpos = cpos + sksz;
1087 		if (artyp == ISREG && mpos > arsb.st_size)
1088 			mpos = arsb.st_size;
1089 		if ((mpos = lseek(arfd, mpos, SEEK_SET)) >= 0) {
1090 			*skipped = mpos - cpos;
1091 			return 0;
1092 		}
1093 	} else {
1094 		if (artyp != ISREG)
1095 			return 0;		/* non-seekable device */
1096 	}
1097 	syswarn(1, errno, "Forward positioning operation on archive failed");
1098 	lstrval = -1;
1099 	return -1;
1100 }
1101 
1102 /*
1103  * ar_rev()
1104  *	move the i/o position within the archive backwards the specified byte
1105  *	count as supported by the device. With tapes drives we RESET rdblksz to
1106  *	the PHYSICAL blocksize.
1107  *	NOTE: We should only be called to move backwards so we can rewrite the
1108  *	last records (the trailer) of an archive (APPEND).
1109  * Return:
1110  *	0 if moved the requested distance, -1 on complete failure
1111  */
1112 
1113 int
ar_rev(off_t sksz)1114 ar_rev(off_t sksz)
1115 {
1116 	off_t cpos;
1117 #ifdef HAVE_SYS_MTIO_H
1118 	int phyblk;
1119 	struct mtop mb;
1120 #endif
1121 
1122 	/*
1123 	 * make sure we do not have try to reverse on a flawed archive
1124 	 */
1125 	if (lstrval < 0)
1126 		return lstrval;
1127 
1128 	switch(artyp) {
1129 	case ISPIPE:
1130 		if (sksz <= 0)
1131 			break;
1132 		/*
1133 		 * cannot go backwards on these critters
1134 		 */
1135 		tty_warn(1, "Reverse positioning on pipes is not supported.");
1136 		lstrval = -1;
1137 		return -1;
1138 	case ISREG:
1139 	case ISBLK:
1140 	case ISCHR:
1141 	default:
1142 		if (sksz <= 0)
1143 			break;
1144 
1145 		/*
1146 		 * For things other than files, backwards movement has a very
1147 		 * high probability of failure as we really do not know the
1148 		 * true attributes of the device we are talking to (the device
1149 		 * may not even have the ability to lseek() in any direction).
1150 		 * First we figure out where we are in the archive.
1151 		 */
1152 		if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) {
1153 			syswarn(1, errno,
1154 			   "Unable to obtain current archive byte offset");
1155 			lstrval = -1;
1156 			return -1;
1157 		}
1158 
1159 		/*
1160 		 * we may try to go backwards past the start when the archive
1161 		 * is only a single record. If this happens and we are on a
1162 		 * multi-volume archive, we need to go to the end of the
1163 		 * previous volume and continue our movement backwards from
1164 		 * there.
1165 		 */
1166 		if ((cpos -= sksz) < (off_t)0L) {
1167 			if (arvol > 1) {
1168 				/*
1169 				 * this should never happen
1170 				 */
1171 				tty_warn(1,
1172 				    "Reverse position on previous volume.");
1173 				lstrval = -1;
1174 				return -1;
1175 			}
1176 			cpos = (off_t)0L;
1177 		}
1178 		if (lseek(arfd, cpos, SEEK_SET) < 0) {
1179 			syswarn(1, errno, "Unable to seek archive backwards");
1180 			lstrval = -1;
1181 			return -1;
1182 		}
1183 		break;
1184 	case ISTAPE:
1185 #ifdef SUPPORT_RMT
1186 	case ISRMT:
1187 #endif /* SUPPORT_RMT */
1188 #ifdef HAVE_SYS_MTIO_H
1189 		/*
1190 		 * Calculate and move the proper number of PHYSICAL tape
1191 		 * blocks. If the sksz is not an even multiple of the physical
1192 		 * tape size, we cannot do the move (this should never happen).
1193 		 * (We also cannot handle trailers spread over two vols).
1194 		 * get_phys() also makes sure we are in front of the filemark.
1195 		 */
1196 		if ((phyblk = get_phys()) <= 0) {
1197 			lstrval = -1;
1198 			return -1;
1199 		}
1200 
1201 		/*
1202 		 * make sure future tape reads only go by physical tape block
1203 		 * size (set rdblksz to the real size).
1204 		 */
1205 		rdblksz = phyblk;
1206 
1207 		/*
1208 		 * if no movement is required, just return (we must be after
1209 		 * get_phys() so the physical blocksize is properly set)
1210 		 */
1211 		if (sksz <= 0)
1212 			break;
1213 
1214 		/*
1215 		 * ok we have to move. Make sure the tape drive can do it.
1216 		 */
1217 		if (sksz % phyblk) {
1218 			tty_warn(1,
1219 			    "Tape drive unable to backspace requested amount");
1220 			lstrval = -1;
1221 			return -1;
1222 		}
1223 
1224 		/*
1225 		 * move backwards the requested number of bytes
1226 		 */
1227 		mb.mt_op = MTBSR;
1228 		mb.mt_count = sksz/phyblk;
1229 		if (
1230 #ifdef SUPPORT_RMT
1231 		    rmtioctl(arfd, MTIOCTOP, &mb)
1232 #else
1233 		    ioctl(arfd, MTIOCTOP, &mb)
1234 #endif /* SUPPORT_RMT */
1235 		    < 0) {
1236 			syswarn(1, errno, "Unable to backspace tape %ld blocks.",
1237 			    (long) mb.mt_count);
1238 			lstrval = -1;
1239 			return -1;
1240 		}
1241 #else
1242 		tty_warn(1, "System does not have tape support");
1243 #endif
1244 		break;
1245 	}
1246 	lstrval = 1;
1247 	return 0;
1248 }
1249 
1250 #ifdef HAVE_SYS_MTIO_H
1251 /*
1252  * get_phys()
1253  *	Determine the physical block size on a tape drive. We need the physical
1254  *	block size so we know how many bytes we skip over when we move with
1255  *	mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when
1256  *	return.
1257  *	This is one really SLOW routine...
1258  * Return:
1259  *	physical block size if ok (ok > 0), -1 otherwise
1260  */
1261 
1262 static int
get_phys(void)1263 get_phys(void)
1264 {
1265 	int padsz = 0;
1266 	int res;
1267 	int phyblk;
1268 	struct mtop mb;
1269 	char scbuf[MAXBLK];
1270 
1271 	/*
1272 	 * move to the file mark, and then back up one record and read it.
1273 	 * this should tell us the physical record size the tape is using.
1274 	 */
1275 	if (lstrval == 1) {
1276 		/*
1277 		 * we know we are at file mark when we get back a 0 from
1278 		 * read()
1279 		 */
1280 #ifdef SUPPORT_RMT
1281 		while ((res = rmtread_with_restart(arfd,
1282 						   scbuf, sizeof(scbuf))) > 0)
1283 #else
1284 		while ((res = read_with_restart(arfd,
1285 						scbuf, sizeof(scbuf))) > 0)
1286 #endif /* SUPPORT_RMT */
1287 			padsz += res;
1288 		if (res < 0) {
1289 			syswarn(1, errno, "Unable to locate tape filemark.");
1290 			return -1;
1291 		}
1292 	}
1293 
1294 	/*
1295 	 * move backwards over the file mark so we are at the end of the
1296 	 * last record.
1297 	 */
1298 	mb.mt_op = MTBSF;
1299 	mb.mt_count = 1;
1300 	if (
1301 #ifdef SUPPORT_RMT
1302 	    rmtioctl(arfd, MTIOCTOP, &mb)
1303 #else
1304 	    ioctl(arfd, MTIOCTOP, &mb)
1305 #endif /* SUPPORT_RMT */
1306 	    < 0) {
1307 		syswarn(1, errno, "Unable to backspace over tape filemark.");
1308 		return -1;
1309 	}
1310 
1311 	/*
1312 	 * move backwards so we are in front of the last record and read it to
1313 	 * get physical tape blocksize.
1314 	 */
1315 	mb.mt_op = MTBSR;
1316 	mb.mt_count = 1;
1317 	if (
1318 #ifdef SUPPORT_RMT
1319 	    rmtioctl(arfd, MTIOCTOP, &mb)
1320 #else
1321 	    ioctl(arfd, MTIOCTOP, &mb)
1322 #endif /* SUPPORT_RMT */
1323 	    < 0) {
1324 		syswarn(1, errno, "Unable to backspace over last tape block.");
1325 		return -1;
1326 	}
1327 	if ((phyblk =
1328 #ifdef SUPPORT_RMT
1329 	     rmtread_with_restart(arfd, scbuf, sizeof(scbuf))
1330 #else
1331 	     read_with_restart(arfd, scbuf, sizeof(scbuf))
1332 #endif /* SUPPORT_RMT */
1333 	    ) <= 0) {
1334 		syswarn(1, errno, "Cannot determine archive tape blocksize.");
1335 		return -1;
1336 	}
1337 
1338 	/*
1339 	 * read forward to the file mark, then back up in front of the filemark
1340 	 * (this is a bit paranoid, but should be safe to do).
1341 	 */
1342 	while ((res =
1343 #ifdef SUPPORT_RMT
1344 		rmtread_with_restart(arfd, scbuf, sizeof(scbuf))
1345 #else
1346 		read_with_restart(arfd, scbuf, sizeof(scbuf))
1347 #endif /* SUPPORT_RMT */
1348 	       ) > 0)
1349 		;
1350 	if (res < 0) {
1351 		syswarn(1, errno, "Unable to locate tape filemark.");
1352 		return -1;
1353 	}
1354 	mb.mt_op = MTBSF;
1355 	mb.mt_count = 1;
1356 	if (
1357 #ifdef SUPPORT_RMT
1358 	    rmtioctl(arfd, MTIOCTOP, &mb)
1359 #else
1360 	    ioctl(arfd, MTIOCTOP, &mb)
1361 #endif /* SUPPORT_RMT */
1362 	    < 0) {
1363 		syswarn(1, errno, "Unable to backspace over tape filemark.");
1364 		return -1;
1365 	}
1366 
1367 	/*
1368 	 * set lstrval so we know that the filemark has not been seen
1369 	 */
1370 	lstrval = 1;
1371 
1372 	/*
1373 	 * return if there was no padding
1374 	 */
1375 	if (padsz == 0)
1376 		return phyblk;
1377 
1378 	/*
1379 	 * make sure we can move backwards over the padding. (this should
1380 	 * never fail).
1381 	 */
1382 	if (padsz % phyblk) {
1383 		tty_warn(1, "Tape drive unable to backspace requested amount");
1384 		return -1;
1385 	}
1386 
1387 	/*
1388 	 * move backwards over the padding so the head is where it was when
1389 	 * we were first called (if required).
1390 	 */
1391 	mb.mt_op = MTBSR;
1392 	mb.mt_count = padsz/phyblk;
1393 	if (
1394 #ifdef SUPPORT_RMT
1395 	    rmtioctl(arfd, MTIOCTOP, &mb)
1396 #else
1397 	    ioctl(arfd, MTIOCTOP, &mb)
1398 #endif /* SUPPORT_RMT */
1399 	    < 0) {
1400 		syswarn(1, errno,
1401 		    "Unable to backspace tape over %ld pad blocks",
1402 		    (long)mb.mt_count);
1403 		return -1;
1404 	}
1405 	return phyblk;
1406 }
1407 #endif
1408 
1409 /*
1410  * ar_next()
1411  *	prompts the user for the next volume in this archive. For some devices
1412  *	we may allow the media to be changed. Otherwise a new archive is
1413  *	prompted for. By pax spec, if there is no controlling tty or an eof is
1414  *	read on tty input, we must quit pax.
1415  * Return:
1416  *	0 when ready to continue, -1 when all done
1417  */
1418 
1419 int
ar_next(void)1420 ar_next(void)
1421 {
1422 	char buf[PAXPATHLEN+2];
1423 	static char *arcfree = NULL;
1424 	sigset_t o_mask;
1425 
1426 	/*
1427 	 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so
1428 	 * things like writing EOF etc will be done) (Watch out ar_close() can
1429 	 * also be called via a signal handler, so we must prevent a race.
1430 	 */
1431 	if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0)
1432 		syswarn(0, errno, "Unable to set signal mask");
1433 	ar_close();
1434 	if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0)
1435 		syswarn(0, errno, "Unable to restore signal mask");
1436 
1437 	if (done || !wr_trail || force_one_volume)
1438 		return -1;
1439 
1440 	if (!is_gnutar)
1441 		tty_prnt("\nATTENTION! %s archive volume change required.\n",
1442 		    argv0);
1443 
1444 	/*
1445 	 * if i/o is on stdin or stdout, we cannot reopen it (we do not know
1446 	 * the name), the user will be forced to type it in.
1447 	 */
1448 	if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG)
1449 	    && (artyp != ISPIPE)) {
1450 		if (artyp == ISTAPE
1451 #ifdef SUPPORT_RMT
1452 		    || artyp == ISRMT
1453 #endif /* SUPPORT_RMT */
1454 		    ) {
1455 			tty_prnt("%s ready for archive tape volume: %d\n",
1456 				arcname, arvol);
1457 			tty_prnt("Load the NEXT TAPE on the tape drive");
1458 		} else {
1459 			tty_prnt("%s ready for archive volume: %d\n",
1460 				arcname, arvol);
1461 			tty_prnt("Load the NEXT STORAGE MEDIA (if required)");
1462 		}
1463 
1464 		if ((act == ARCHIVE) || (act == APPND))
1465 			tty_prnt(" and make sure it is WRITE ENABLED.\n");
1466 		else
1467 			tty_prnt("\n");
1468 
1469 		for(;;) {
1470 			tty_prnt("Type \"y\" to continue, \".\" to quit %s,",
1471 				argv0);
1472 			tty_prnt(" or \"s\" to switch to new device.\nIf you");
1473 			tty_prnt(" cannot change storage media, type \"s\"\n");
1474 			tty_prnt("Is the device ready and online? > ");
1475 
1476 			if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){
1477 				done = 1;
1478 				lstrval = -1;
1479 				tty_prnt("Quitting %s!\n", argv0);
1480 				vfpart = 0;
1481 				return -1;
1482 			}
1483 
1484 			if ((buf[0] == '\0') || (buf[1] != '\0')) {
1485 				tty_prnt("%s unknown command, try again\n",buf);
1486 				continue;
1487 			}
1488 
1489 			switch (buf[0]) {
1490 			case 'y':
1491 			case 'Y':
1492 				/*
1493 				 * we are to continue with the same device
1494 				 */
1495 				if (ar_open(arcname) >= 0)
1496 					return 0;
1497 				tty_prnt("Cannot re-open %s, try again\n",
1498 					arcname);
1499 				continue;
1500 			case 's':
1501 			case 'S':
1502 				/*
1503 				 * user wants to open a different device
1504 				 */
1505 				tty_prnt("Switching to a different archive\n");
1506 				break;
1507 			default:
1508 				tty_prnt("%s unknown command, try again\n",buf);
1509 				continue;
1510 			}
1511 			break;
1512 		}
1513 	} else {
1514 		if (is_gnutar) {
1515 			tty_warn(1, "Unexpected EOF on archive file");
1516 			return -1;
1517 		}
1518 		tty_prnt("Ready for archive volume: %d\n", arvol);
1519 	}
1520 
1521 	/*
1522 	 * have to go to a different archive
1523 	 */
1524 	for (;;) {
1525 		tty_prnt("Input archive name or \".\" to quit %s.\n", argv0);
1526 		tty_prnt("Archive name > ");
1527 
1528 		if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) {
1529 			done = 1;
1530 			lstrval = -1;
1531 			tty_prnt("Quitting %s!\n", argv0);
1532 			vfpart = 0;
1533 			return -1;
1534 		}
1535 		if (buf[0] == '\0') {
1536 			tty_prnt("Empty file name, try again\n");
1537 			continue;
1538 		}
1539 		if (!strcmp(buf, "..")) {
1540 			tty_prnt("Illegal file name: .. try again\n");
1541 			continue;
1542 		}
1543 		if (strlen(buf) > PAXPATHLEN) {
1544 			tty_prnt("File name too long, try again\n");
1545 			continue;
1546 		}
1547 
1548 		/*
1549 		 * try to open new archive
1550 		 */
1551 		if (ar_open(buf) >= 0) {
1552 			if (arcfree) {
1553 				(void)free(arcfree);
1554 				arcfree = NULL;
1555 			}
1556 			if ((arcfree = strdup(buf)) == NULL) {
1557 				done = 1;
1558 				lstrval = -1;
1559 				tty_warn(0, "Cannot save archive name.");
1560 				return -1;
1561 			}
1562 			arcname = arcfree;
1563 			break;
1564 		}
1565 		tty_prnt("Cannot open %s, try again\n", buf);
1566 		continue;
1567 	}
1568 	return 0;
1569 }
1570 
1571 /*
1572  * ar_start_gzip()
1573  * starts the compression/decompression process as a child, using magic
1574  * to keep the fd the same in the calling function (parent). possible
1575  * programs are GZIP_CMD, BZIP2_CMD, and COMPRESS_CMD.
1576  */
1577 void
ar_start_gzip(int fd,const char * gzp,int wr)1578 ar_start_gzip(int fd, const char *gzp, int wr)
1579 {
1580 	int fds[2];
1581 	const char *gzip_flags;
1582 
1583 	if (pipe(fds) < 0)
1584 		err(1, "could not pipe");
1585 	zpid = fork();
1586 	if (zpid < 0)
1587 		err(1, "could not fork");
1588 
1589 	/* parent */
1590 	if (zpid) {
1591 		if (wr)
1592 			dup2(fds[1], fd);
1593 		else
1594 			dup2(fds[0], fd);
1595 		close(fds[0]);
1596 		close(fds[1]);
1597 	} else {
1598 		if (wr) {
1599 			dup2(fds[0], STDIN_FILENO);
1600 			dup2(fd, STDOUT_FILENO);
1601 			gzip_flags = "-c";
1602 		} else {
1603 			dup2(fds[1], STDOUT_FILENO);
1604 			dup2(fd, STDIN_FILENO);
1605 			gzip_flags = "-dc";
1606 		}
1607 		close(fds[0]);
1608 		close(fds[1]);
1609 		if (execlp(gzp, gzp, gzip_flags, NULL) < 0)
1610 			err(1, "could not exec");
1611 		/* NOTREACHED */
1612 	}
1613 }
1614 
1615 static const char *
timefmt(char * buf,size_t size,off_t sz,time_t tm,const char * unitstr)1616 timefmt(char *buf, size_t size, off_t sz, time_t tm, const char *unitstr)
1617 {
1618 	(void)snprintf(buf, size, "%lu secs (" OFFT_F " %s/sec)",
1619 	    (unsigned long)tm, (OFFT_T)(sz / tm), unitstr);
1620 	return buf;
1621 }
1622 
1623 static const char *
sizefmt(char * buf,size_t size,off_t sz)1624 sizefmt(char *buf, size_t size, off_t sz)
1625 {
1626 	(void)snprintf(buf, size, OFFT_F " bytes", (OFFT_T)sz);
1627 	return buf;
1628 }
1629 
1630 void
ar_summary(int n)1631 ar_summary(int n)
1632 {
1633 	time_t secs;
1634 	int len;
1635 	char buf[BUFSIZ];
1636 	char tbuf[MAXPATHLEN/4];	/* XXX silly size! */
1637 	char s1buf[MAXPATHLEN/8];	/* XXX very silly size! */
1638 	char s2buf[MAXPATHLEN/8];	/* XXX very silly size! */
1639 	FILE *outf;
1640 
1641 	if (act == LIST)
1642 		outf = stdout;
1643 	else
1644 		outf = stderr;
1645 
1646 	/*
1647 	 * If we are called from a signal (n != 0), use snprintf(3) so that we
1648 	 * don't reenter stdio(3).
1649 	 */
1650 	(void)time(&secs);
1651 	if ((secs -= starttime) == 0)
1652 		secs = 1;
1653 
1654 	/*
1655 	 * If we have not determined the format yet, we just say how many bytes
1656 	 * we have skipped over looking for a header to id. there is no way we
1657 	 * could have written anything yet.
1658 	 */
1659 	if (frmt == NULL && act != COPY) {
1660 		len = snprintf(buf, sizeof(buf),
1661 		    "unknown format, %s skipped in %s\n",
1662 		    sizefmt(s1buf, sizeof(s1buf), rdcnt),
1663 		    timefmt(tbuf, sizeof(tbuf), rdcnt, secs, "bytes"));
1664 		if (n == 0)
1665 			(void)fprintf(outf, "%s: %s", argv0, buf);
1666 		else
1667 			(void)write(STDERR_FILENO, buf, len);
1668 		return;
1669 	}
1670 
1671 
1672 	if (n != 0 && *archd.name) {
1673 		len = snprintf(buf, sizeof(buf), "Working on `%s' (%s)\n",
1674 		    archd.name, sizefmt(s1buf, sizeof(s1buf), archd.sb.st_size));
1675 		(void)write(STDERR_FILENO, buf, len);
1676 		len = 0;
1677 	}
1678 
1679 
1680 	if (act == COPY) {
1681 		len = snprintf(buf, sizeof(buf),
1682 		    "%lu files in %s\n",
1683 		    (unsigned long)flcnt,
1684 		    timefmt(tbuf, sizeof(tbuf), flcnt, secs, "files"));
1685 	} else {
1686 		len = snprintf(buf, sizeof(buf),
1687 		    "%s vol %d, %lu files, %s read, %s written in %s\n",
1688 		    frmt->name, arvol-1, (unsigned long)flcnt,
1689 		    sizefmt(s1buf, sizeof(s1buf), rdcnt),
1690 		    sizefmt(s2buf, sizeof(s2buf), wrcnt),
1691 		    timefmt(tbuf, sizeof(tbuf), rdcnt + wrcnt, secs, "bytes"));
1692 	}
1693 	if (n == 0)
1694 		(void)fprintf(outf, "%s: %s", argv0, buf);
1695 	else
1696 		(void)write(STDERR_FILENO, buf, strlen(buf));
1697 }
1698 
1699 /*
1700  * ar_dochdir(name)
1701  *	change directory to name, and remember where we came from and
1702  *	where we change to (for ar_open).
1703  *
1704  *	Maybe we could try to be smart and only do the actual chdir
1705  *	when necessary to write a file read from the archive, but this
1706  *	is not easy to get right given the pax code structure.
1707  *
1708  *	Be sure to not leak descriptors!
1709  *
1710  *	We are called N * M times when extracting, and N times when
1711  *	writing archives, where
1712  *	N:	number of -C options
1713  *	M:	number of files in archive
1714  *
1715  * Returns 0 if all went well, else -1.
1716  */
1717 
1718 int
ar_dochdir(const char * name)1719 ar_dochdir(const char *name)
1720 {
1721 	/* First fdochdir() back... */
1722 	if (fdochdir(cwdfd) == -1)
1723 		return -1;
1724 	if (dochdir(name) == -1)
1725 		return -1;
1726 	return 0;
1727 }
1728