xref: /freebsd/sbin/savecore/savecore.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
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. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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  * Copyright (c) 1986, 1992, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 4. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include <sys/param.h>
67 #include <sys/disk.h>
68 #include <sys/kerneldump.h>
69 #include <sys/mount.h>
70 #include <sys/stat.h>
71 #include <errno.h>
72 #include <fcntl.h>
73 #include <fstab.h>
74 #include <paths.h>
75 #include <stdarg.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <syslog.h>
80 #include <time.h>
81 #include <unistd.h>
82 
83 /* The size of the buffer used for I/O. */
84 #define	BUFFERSIZE	(1024*1024)
85 
86 #define	STATUS_BAD	0
87 #define	STATUS_GOOD	1
88 #define	STATUS_UNKNOWN	2
89 
90 static int checkfor, compress, clear, force, keep, verbose;	/* flags */
91 static int nfound, nsaved, nerr;			/* statistics */
92 
93 extern FILE *zopen(const char *, const char *);
94 
95 static sig_atomic_t got_siginfo;
96 static void infohandler(int);
97 
98 static void
99 printheader(FILE *f, const struct kerneldumpheader *h, const char *device,
100     int bounds, const int status)
101 {
102 	uint64_t dumplen;
103 	time_t t;
104 	const char *stat_str;
105 
106 	fprintf(f, "Dump header from device %s\n", device);
107 	fprintf(f, "  Architecture: %s\n", h->architecture);
108 	fprintf(f, "  Architecture Version: %u\n",
109 	    dtoh32(h->architectureversion));
110 	dumplen = dtoh64(h->dumplength);
111 	fprintf(f, "  Dump Length: %lldB (%lld MB)\n", (long long)dumplen,
112 	    (long long)(dumplen >> 20));
113 	fprintf(f, "  Blocksize: %d\n", dtoh32(h->blocksize));
114 	t = dtoh64(h->dumptime);
115 	fprintf(f, "  Dumptime: %s", ctime(&t));
116 	fprintf(f, "  Hostname: %s\n", h->hostname);
117 	fprintf(f, "  Magic: %s\n", h->magic);
118 	fprintf(f, "  Version String: %s", h->versionstring);
119 	fprintf(f, "  Panic String: %s\n", h->panicstring);
120 	fprintf(f, "  Dump Parity: %u\n", h->parity);
121 	fprintf(f, "  Bounds: %d\n", bounds);
122 
123 	switch(status) {
124 	case STATUS_BAD:
125 		stat_str = "bad";
126 		break;
127 	case STATUS_GOOD:
128 		stat_str = "good";
129 		break;
130 	default:
131 		stat_str = "unknown";
132 	}
133 	fprintf(f, "  Dump Status: %s\n", stat_str);
134 	fflush(f);
135 }
136 
137 static int
138 getbounds(void) {
139 	FILE *fp;
140 	char buf[6];
141 	int ret;
142 
143 	ret = 0;
144 
145 	if ((fp = fopen("bounds", "r")) == NULL) {
146 		if (verbose)
147 			printf("unable to open bounds file, using 0\n");
148 		return (ret);
149 	}
150 
151 	if (fgets(buf, sizeof buf, fp) == NULL) {
152 		syslog(LOG_WARNING, "unable to read from bounds, using 0");
153 		fclose(fp);
154 		return (ret);
155 	}
156 
157 	errno = 0;
158 	ret = (int)strtol(buf, NULL, 10);
159 	if (ret == 0 && (errno == EINVAL || errno == ERANGE))
160 		syslog(LOG_WARNING, "invalid value found in bounds, using 0");
161 	return (ret);
162 }
163 
164 static void
165 writebounds(int bounds) {
166 	FILE *fp;
167 
168 	if ((fp = fopen("bounds", "w")) == NULL) {
169 		syslog(LOG_WARNING, "unable to write to bounds file: %m");
170 		return;
171 	}
172 
173 	if (verbose)
174 		printf("bounds number: %d\n", bounds);
175 
176 	fprintf(fp, "%d\n", bounds);
177 	fclose(fp);
178 }
179 
180 /*
181  * Check that sufficient space is available on the disk that holds the
182  * save directory.
183  */
184 static int
185 check_space(const char *savedir, off_t dumpsize)
186 {
187 	FILE *fp;
188 	off_t minfree, spacefree, totfree, needed;
189 	struct statfs fsbuf;
190 	char buf[100], path[MAXPATHLEN];
191 
192 	if (statfs(savedir, &fsbuf) < 0) {
193 		syslog(LOG_ERR, "%s: %m", savedir);
194 		exit(1);
195 	}
196  	spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
197 	totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
198 
199 	(void)snprintf(path, sizeof(path), "%s/minfree", savedir);
200 	if ((fp = fopen(path, "r")) == NULL)
201 		minfree = 0;
202 	else {
203 		if (fgets(buf, sizeof(buf), fp) == NULL)
204 			minfree = 0;
205 		else
206 			minfree = atoi(buf);
207 		(void)fclose(fp);
208 	}
209 
210 	needed = dumpsize / 1024 + 2;	/* 2 for info file */
211  	if (((minfree > 0) ? spacefree : totfree) - needed < minfree) {
212 		syslog(LOG_WARNING,
213 	"no dump, not enough free space on device (%lld available, need %lld)",
214 		    (long long)(minfree > 0 ? spacefree : totfree),
215 		    (long long)needed);
216 		return (0);
217 	}
218 	if (spacefree - needed < 0)
219 		syslog(LOG_WARNING,
220 		    "dump performed, but free space threshold crossed");
221 	return (1);
222 }
223 
224 #define BLOCKSIZE (1<<12)
225 #define BLOCKMASK (~(BLOCKSIZE-1))
226 
227 static int
228 DoRegularFile(int fd, off_t dumpsize, char *buf, const char *device,
229     const char *filename, FILE *fp)
230 {
231 	int he, hs, nr, nw, wl;
232 	off_t dmpcnt, origsize;
233 
234 	dmpcnt = 0;
235 	origsize = dumpsize;
236 	he = 0;
237 	while (dumpsize > 0) {
238 		wl = BUFFERSIZE;
239 		if (wl > dumpsize)
240 			wl = dumpsize;
241 		nr = read(fd, buf, wl);
242 		if (nr != wl) {
243 			if (nr == 0)
244 				syslog(LOG_WARNING,
245 				    "WARNING: EOF on dump device");
246 			else
247 				syslog(LOG_ERR, "read error on %s: %m", device);
248 			nerr++;
249 			return (-1);
250 		}
251 		if (compress) {
252 			nw = fwrite(buf, 1, wl, fp);
253 		} else {
254 			for (nw = 0; nw < nr; nw = he) {
255 				/* find a contiguous block of zeroes */
256 				for (hs = nw; hs < nr; hs += BLOCKSIZE) {
257 					for (he = hs; he < nr && buf[he] == 0;
258 					    ++he)
259 						/* nothing */ ;
260 					/* is the hole long enough to matter? */
261 					if (he >= hs + BLOCKSIZE)
262 						break;
263 				}
264 
265 				/* back down to a block boundary */
266 				he &= BLOCKMASK;
267 
268 				/*
269 				 * 1) Don't go beyond the end of the buffer.
270 				 * 2) If the end of the buffer is less than
271 				 *    BLOCKSIZE bytes away, we're at the end
272 				 *    of the file, so just grab what's left.
273 				 */
274 				if (hs + BLOCKSIZE > nr)
275 					hs = he = nr;
276 
277 				/*
278 				 * At this point, we have a partial ordering:
279 				 *     nw <= hs <= he <= nr
280 				 * If hs > nw, buf[nw..hs] contains non-zero data.
281 				 * If he > hs, buf[hs..he] is all zeroes.
282 				 */
283 				if (hs > nw)
284 					if (fwrite(buf + nw, hs - nw, 1, fp)
285 					    != 1)
286 					break;
287 				if (he > hs)
288 					if (fseeko(fp, he - hs, SEEK_CUR) == -1)
289 						break;
290 			}
291 		}
292 		if (nw != wl) {
293 			syslog(LOG_ERR,
294 			    "write error on %s file: %m", filename);
295 			syslog(LOG_WARNING,
296 			    "WARNING: vmcore may be incomplete");
297 			nerr++;
298 			return (-1);
299 		}
300 		if (verbose) {
301 			dmpcnt += wl;
302 			printf("%llu\r", (unsigned long long)dmpcnt);
303 			fflush(stdout);
304 		}
305 		dumpsize -= wl;
306 		if (got_siginfo) {
307 			printf("%s %.1lf%%\n", filename, (100.0 - (100.0 *
308 			    (double)dumpsize / (double)origsize)));
309 			got_siginfo = 0;
310 		}
311 	}
312 	return (0);
313 }
314 
315 /*
316  * Specialized version of dump-reading logic for use with textdumps, which
317  * are written backwards from the end of the partition, and must be reversed
318  * before being written to the file.  Textdumps are small, so do a bit less
319  * work to optimize/sparsify.
320  */
321 static int
322 DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
323     const char *device, const char *filename, FILE *fp)
324 {
325 	int nr, nw, wl;
326 	off_t dmpcnt, totsize;
327 
328 	totsize = dumpsize;
329 	dmpcnt = 0;
330 	wl = 512;
331 	if ((dumpsize % wl) != 0) {
332 		syslog(LOG_ERR, "textdump uneven multiple of 512 on %s",
333 		    device);
334 		nerr++;
335 		return (-1);
336 	}
337 	while (dumpsize > 0) {
338 		nr = pread(fd, buf, wl, lasthd - (totsize - dumpsize) - wl);
339 		if (nr != wl) {
340 			if (nr == 0)
341 				syslog(LOG_WARNING,
342 				    "WARNING: EOF on dump device");
343 			else
344 				syslog(LOG_ERR, "read error on %s: %m", device);
345 			nerr++;
346 			return (-1);
347 		}
348 		nw = fwrite(buf, 1, wl, fp);
349 		if (nw != wl) {
350 			syslog(LOG_ERR,
351 			    "write error on %s file: %m", filename);
352 			syslog(LOG_WARNING,
353 			    "WARNING: textdump may be incomplete");
354 			nerr++;
355 			return (-1);
356 		}
357 		if (verbose) {
358 			dmpcnt += wl;
359 			printf("%llu\r", (unsigned long long)dmpcnt);
360 			fflush(stdout);
361 		}
362 		dumpsize -= wl;
363 	}
364 	return (0);
365 }
366 
367 static void
368 DoFile(const char *savedir, const char *device)
369 {
370 	static char filename[PATH_MAX];
371 	static char *buf = NULL;
372 	struct kerneldumpheader kdhf, kdhl;
373 	off_t mediasize, dumpsize, firsthd, lasthd;
374 	FILE *info, *fp;
375 	mode_t oumask;
376 	int fd, fdinfo, error;
377 	int bounds, status;
378 	u_int sectorsize;
379 	int istextdump;
380 
381 	bounds = getbounds();
382 	mediasize = 0;
383 	status = STATUS_UNKNOWN;
384 
385 	if (buf == NULL) {
386 		buf = malloc(BUFFERSIZE);
387 		if (buf == NULL) {
388 			syslog(LOG_ERR, "%m");
389 			return;
390 		}
391 	}
392 
393 	if (verbose)
394 		printf("checking for kernel dump on device %s\n", device);
395 
396 	fd = open(device, O_RDWR);
397 	if (fd < 0) {
398 		syslog(LOG_ERR, "%s: %m", device);
399 		return;
400 	}
401 
402 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
403 	if (!error)
404 		error = ioctl(fd, DIOCGSECTORSIZE, &sectorsize);
405 	if (error) {
406 		syslog(LOG_ERR,
407 		    "couldn't find media and/or sector size of %s: %m", device);
408 		goto closefd;
409 	}
410 
411 	if (verbose) {
412 		printf("mediasize = %lld\n", (long long)mediasize);
413 		printf("sectorsize = %u\n", sectorsize);
414 	}
415 
416 	lasthd = mediasize - sectorsize;
417 	lseek(fd, lasthd, SEEK_SET);
418 	error = read(fd, &kdhl, sizeof kdhl);
419 	if (error != sizeof kdhl) {
420 		syslog(LOG_ERR,
421 		    "error reading last dump header at offset %lld in %s: %m",
422 		    (long long)lasthd, device);
423 		goto closefd;
424 	}
425 	istextdump = 0;
426 	if (strncmp(kdhl.magic, TEXTDUMPMAGIC, sizeof kdhl) == 0) {
427 		if (verbose)
428 			printf("textdump magic on last dump header on %s\n",
429 			    device);
430 		istextdump = 1;
431 		if (dtoh32(kdhl.version) != KERNELDUMP_TEXT_VERSION) {
432 			syslog(LOG_ERR,
433 			    "unknown version (%d) in last dump header on %s",
434 			    dtoh32(kdhl.version), device);
435 
436 			status = STATUS_BAD;
437 			if (force == 0)
438 				goto closefd;
439 		}
440 	} else if (memcmp(kdhl.magic, KERNELDUMPMAGIC, sizeof kdhl.magic) ==
441 	    0) {
442 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
443 			syslog(LOG_ERR,
444 			    "unknown version (%d) in last dump header on %s",
445 			    dtoh32(kdhl.version), device);
446 
447 			status = STATUS_BAD;
448 			if (force == 0)
449 				goto closefd;
450 		}
451 	} else {
452 		if (verbose)
453 			printf("magic mismatch on last dump header on %s\n",
454 			    device);
455 
456 		status = STATUS_BAD;
457 		if (force == 0)
458 			goto closefd;
459 
460 		if (memcmp(kdhl.magic, KERNELDUMPMAGIC_CLEARED,
461 			    sizeof kdhl.magic) == 0) {
462 			if (verbose)
463 				printf("forcing magic on %s\n", device);
464 			memcpy(kdhl.magic, KERNELDUMPMAGIC,
465 			    sizeof kdhl.magic);
466 		} else {
467 			syslog(LOG_ERR, "unable to force dump - bad magic");
468 			goto closefd;
469 		}
470 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
471 			syslog(LOG_ERR,
472 			    "unknown version (%d) in last dump header on %s",
473 			    dtoh32(kdhl.version), device);
474 
475 			status = STATUS_BAD;
476 			if (force == 0)
477 				goto closefd;
478 		}
479 	}
480 
481 	nfound++;
482 	if (clear)
483 		goto nuke;
484 
485 	if (kerneldump_parity(&kdhl)) {
486 		syslog(LOG_ERR,
487 		    "parity error on last dump header on %s", device);
488 		nerr++;
489 		status = STATUS_BAD;
490 		if (force == 0)
491 			goto closefd;
492 	}
493 	dumpsize = dtoh64(kdhl.dumplength);
494 	firsthd = lasthd - dumpsize - sizeof kdhf;
495 	lseek(fd, firsthd, SEEK_SET);
496 	error = read(fd, &kdhf, sizeof kdhf);
497 	if (error != sizeof kdhf) {
498 		syslog(LOG_ERR,
499 		    "error reading first dump header at offset %lld in %s: %m",
500 		    (long long)firsthd, device);
501 		nerr++;
502 		goto closefd;
503 	}
504 
505 	if (verbose >= 2) {
506 		printf("First dump headers:\n");
507 		printheader(stdout, &kdhf, device, bounds, -1);
508 
509 		printf("\nLast dump headers:\n");
510 		printheader(stdout, &kdhl, device, bounds, -1);
511 		printf("\n");
512 	}
513 
514 	if (memcmp(&kdhl, &kdhf, sizeof kdhl)) {
515 		syslog(LOG_ERR,
516 		    "first and last dump headers disagree on %s", device);
517 		nerr++;
518 		status = STATUS_BAD;
519 		if (force == 0)
520 			goto closefd;
521 	} else {
522 		status = STATUS_GOOD;
523 	}
524 
525 	if (checkfor) {
526 		printf("A dump exists on %s\n", device);
527 		close(fd);
528 		exit(0);
529 	}
530 
531 	if (kdhl.panicstring[0])
532 		syslog(LOG_ALERT, "reboot after panic: %s", kdhl.panicstring);
533 	else
534 		syslog(LOG_ALERT, "reboot");
535 
536 	if (verbose)
537 		printf("Checking for available free space\n");
538 	if (!check_space(savedir, dumpsize)) {
539 		nerr++;
540 		goto closefd;
541 	}
542 
543 	writebounds(bounds + 1);
544 
545 	sprintf(buf, "info.%d", bounds);
546 
547 	/*
548 	 * Create or overwrite any existing dump header files.
549 	 */
550 	fdinfo = open(buf, O_WRONLY | O_CREAT | O_TRUNC, 0600);
551 	if (fdinfo < 0) {
552 		syslog(LOG_ERR, "%s: %m", buf);
553 		nerr++;
554 		goto closefd;
555 	}
556 	oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
557 	if (compress) {
558 		sprintf(filename, "%s.%d.gz", istextdump ? "textdump.tar" :
559 		    "vmcore", bounds);
560 		fp = zopen(filename, "w");
561 	} else {
562 		sprintf(filename, "%s.%d", istextdump ? "textdump.tar" :
563 		    "vmcore", bounds);
564 		fp = fopen(filename, "w");
565 	}
566 	if (fp == NULL) {
567 		syslog(LOG_ERR, "%s: %m", filename);
568 		close(fdinfo);
569 		nerr++;
570 		goto closefd;
571 	}
572 	(void)umask(oumask);
573 
574 	info = fdopen(fdinfo, "w");
575 
576 	if (info == NULL) {
577 		syslog(LOG_ERR, "fdopen failed: %m");
578 		nerr++;
579 		goto closefd;
580 	}
581 
582 	if (verbose)
583 		printheader(stdout, &kdhl, device, bounds, status);
584 
585 	printheader(info, &kdhl, device, bounds, status);
586 	fclose(info);
587 
588 	syslog(LOG_NOTICE, "writing %score to %s",
589 	    compress ? "compressed " : "", filename);
590 
591 	if (istextdump) {
592 		if (DoTextdumpFile(fd, dumpsize, lasthd, buf, device,
593 		    filename, fp) < 0)
594 			goto closeall;
595 	} else {
596 		if (DoRegularFile(fd, dumpsize, buf, device, filename, fp)
597 		    < 0)
598 			goto closeall;
599 	}
600 	if (verbose)
601 		printf("\n");
602 
603 	if (fclose(fp) < 0) {
604 		syslog(LOG_ERR, "error on %s: %m", filename);
605 		nerr++;
606 		goto closeall;
607 	}
608 	nsaved++;
609 
610 	if (verbose)
611 		printf("dump saved\n");
612 
613 nuke:
614 	if (clear || !keep) {
615 		if (verbose)
616 			printf("clearing dump header\n");
617 		memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof kdhl.magic);
618 		lseek(fd, lasthd, SEEK_SET);
619 		error = write(fd, &kdhl, sizeof kdhl);
620 		if (error != sizeof kdhl)
621 			syslog(LOG_ERR,
622 			    "error while clearing the dump header: %m");
623 	}
624 	close(fd);
625 	return;
626 
627 closeall:
628 	fclose(fp);
629 
630 closefd:
631 	close(fd);
632 }
633 
634 static void
635 usage(void)
636 {
637 	fprintf(stderr, "%s\n%s\n%s\n",
638 	    "usage: savecore -c",
639 	    "       savecore -C [-v] [directory device]",
640 	    "       savecore [-fkvz] [directory [device ...]]");
641 	exit (1);
642 }
643 
644 int
645 main(int argc, char **argv)
646 {
647 	const char *savedir = ".";
648 	struct fstab *fsp;
649 	int i, ch, error;
650 
651 	checkfor = compress = clear = force = keep = verbose = 0;
652 	nfound = nsaved = nerr = 0;
653 
654 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
655 	signal(SIGINFO, infohandler);
656 
657 	while ((ch = getopt(argc, argv, "Ccfkvz")) != -1)
658 		switch(ch) {
659 		case 'C':
660 			checkfor = 1;
661 			break;
662 		case 'c':
663 			clear = 1;
664 			break;
665 		case 'k':
666 			keep = 1;
667 			break;
668 		case 'v':
669 			verbose++;
670 			break;
671 		case 'f':
672 			force = 1;
673 			break;
674 		case 'z':
675 			compress = 1;
676 			break;
677 		case '?':
678 		default:
679 			usage();
680 		}
681 	if (checkfor && (clear || force || keep))
682 		usage();
683 	argc -= optind;
684 	argv += optind;
685 	if (argc >= 1) {
686 		error = chdir(argv[0]);
687 		if (error) {
688 			syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
689 			exit(1);
690 		}
691 		savedir = argv[0];
692 		argc--;
693 		argv++;
694 	}
695 	if (argc == 0) {
696 		for (;;) {
697 			fsp = getfsent();
698 			if (fsp == NULL)
699 				break;
700 			if (strcmp(fsp->fs_vfstype, "swap") &&
701 			    strcmp(fsp->fs_vfstype, "dump"))
702 				continue;
703 			DoFile(savedir, fsp->fs_spec);
704 		}
705 	} else {
706 		for (i = 0; i < argc; i++)
707 			DoFile(savedir, argv[i]);
708 	}
709 
710 	/* Emit minimal output. */
711 	if (nfound == 0) {
712 		if (checkfor) {
713 			printf("No dump exists\n");
714 			exit(1);
715 		}
716 		syslog(LOG_WARNING, "no dumps found");
717 	}
718 	else if (nsaved == 0) {
719 		if (nerr != 0)
720 			syslog(LOG_WARNING, "unsaved dumps found but not saved");
721 		else
722 			syslog(LOG_WARNING, "no unsaved dumps found");
723 	}
724 
725 	return (0);
726 }
727 
728 static void
729 infohandler(int sig __unused)
730 {
731 	got_siginfo = 1;
732 }
733