xref: /freebsd/sbin/savecore/savecore.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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 <signal.h>
76 #include <stdarg.h>
77 #include <stdio.h>
78 #include <stdlib.h>
79 #include <string.h>
80 #include <syslog.h>
81 #include <time.h>
82 #include <unistd.h>
83 #include <libxo/xo.h>
84 
85 /* The size of the buffer used for I/O. */
86 #define	BUFFERSIZE	(1024*1024)
87 
88 #define	STATUS_BAD	0
89 #define	STATUS_GOOD	1
90 #define	STATUS_UNKNOWN	2
91 
92 static int checkfor, compress, clear, force, keep, verbose;	/* flags */
93 static int nfound, nsaved, nerr;			/* statistics */
94 static int maxdumps;
95 
96 extern FILE *zopen(const char *, const char *);
97 
98 static sig_atomic_t got_siginfo;
99 static void infohandler(int);
100 
101 static void
102 printheader(xo_handle_t *xo, const struct kerneldumpheader *h, const char *device,
103     int bounds, const int status)
104 {
105 	uint64_t dumplen;
106 	time_t t;
107 	const char *stat_str;
108 
109 	xo_flush_h(xo);
110 	xo_emit_h(xo, "{Lwc:Dump header from device}{:dump_device/%s}\n", device);
111 	xo_emit_h(xo, "{P:  }{Lwc:Architecture}{:architecture/%s}\n", h->architecture);
112 	xo_emit_h(xo, "{P:  }{Lwc:Architecture Version}{:architecture_version/%u}\n", dtoh32(h->architectureversion));
113 	dumplen = dtoh64(h->dumplength);
114 	xo_emit_h(xo, "{P:  }{Lwc:Dump Length}{:dump_length_bytes/%lld}\n", (long long)dumplen);
115 	xo_emit_h(xo, "{P:  }{Lwc:Blocksize}{:blocksize/%d}\n", dtoh32(h->blocksize));
116 	t = dtoh64(h->dumptime);
117 	xo_emit_h(xo, "{P:  }{Lwc:Dumptime}{:dumptime/%s}", ctime(&t));
118 	xo_emit_h(xo, "{P:  }{Lwc:Hostname}{:hostname/%s}\n", h->hostname);
119 	xo_emit_h(xo, "{P:  }{Lwc:Magic}{:magic/%s}\n", h->magic);
120 	xo_emit_h(xo, "{P:  }{Lwc:Version String}{:version_string/%s}", h->versionstring);
121 	xo_emit_h(xo, "{P:  }{Lwc:Panic String}{:panic_string/%s}\n", h->panicstring);
122 	xo_emit_h(xo, "{P:  }{Lwc:Dump Parity}{:dump_parity/%u}\n", h->parity);
123 	xo_emit_h(xo, "{P:  }{Lwc:Bounds}{:bounds/%d}\n", bounds);
124 
125 	switch(status) {
126 	case STATUS_BAD:
127 		stat_str = "bad";
128 		break;
129 	case STATUS_GOOD:
130 		stat_str = "good";
131 		break;
132 	default:
133 		stat_str = "unknown";
134 	}
135 	xo_emit_h(xo, "{P:  }{Lwc:Dump Status}{:dump_status/%s}\n", stat_str);
136 	xo_flush_h(xo);
137 }
138 
139 static int
140 getbounds(void) {
141 	FILE *fp;
142 	char buf[6];
143 	int ret;
144 
145 	ret = 0;
146 
147 	if ((fp = fopen("bounds", "r")) == NULL) {
148 		if (verbose)
149 			printf("unable to open bounds file, using 0\n");
150 		return (ret);
151 	}
152 
153 	if (fgets(buf, sizeof buf, fp) == NULL) {
154 		if (feof(fp))
155 			syslog(LOG_WARNING, "bounds file is empty, using 0");
156 		else
157 			syslog(LOG_WARNING, "bounds file: %s", strerror(errno));
158 		fclose(fp);
159 		return (ret);
160 	}
161 
162 	errno = 0;
163 	ret = (int)strtol(buf, NULL, 10);
164 	if (ret == 0 && (errno == EINVAL || errno == ERANGE))
165 		syslog(LOG_WARNING, "invalid value found in bounds, using 0");
166 	fclose(fp);
167 	return (ret);
168 }
169 
170 static void
171 writebounds(int bounds) {
172 	FILE *fp;
173 
174 	if ((fp = fopen("bounds", "w")) == NULL) {
175 		syslog(LOG_WARNING, "unable to write to bounds file: %m");
176 		return;
177 	}
178 
179 	if (verbose)
180 		printf("bounds number: %d\n", bounds);
181 
182 	fprintf(fp, "%d\n", bounds);
183 	fclose(fp);
184 }
185 
186 static off_t
187 file_size(const char *path)
188 {
189 	struct stat sb;
190 
191 	/* Ignore all errors, those file may not exists. */
192 	if (stat(path, &sb) == -1)
193 		return (0);
194 	return (sb.st_size);
195 }
196 
197 static off_t
198 saved_dump_size(int bounds)
199 {
200 	static char path[PATH_MAX];
201 	off_t dumpsize;
202 
203 	dumpsize = 0;
204 
205 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
206 	dumpsize += file_size(path);
207 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
208 	dumpsize += file_size(path);
209 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
210 	dumpsize += file_size(path);
211 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
212 	dumpsize += file_size(path);
213 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
214 	dumpsize += file_size(path);
215 
216 	return (dumpsize);
217 }
218 
219 static void
220 saved_dump_remove(int bounds)
221 {
222 	static char path[PATH_MAX];
223 
224 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
225 	(void)unlink(path);
226 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
227 	(void)unlink(path);
228 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
229 	(void)unlink(path);
230 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
231 	(void)unlink(path);
232 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
233 	(void)unlink(path);
234 }
235 
236 static void
237 symlinks_remove(void)
238 {
239 
240 	(void)unlink("info.last");
241 	(void)unlink("vmcore.last");
242 	(void)unlink("vmcore.last.gz");
243 	(void)unlink("textdump.tar.last");
244 	(void)unlink("textdump.tar.last.gz");
245 }
246 
247 /*
248  * Check that sufficient space is available on the disk that holds the
249  * save directory.
250  */
251 static int
252 check_space(const char *savedir, off_t dumpsize, int bounds)
253 {
254 	FILE *fp;
255 	off_t minfree, spacefree, totfree, needed;
256 	struct statfs fsbuf;
257 	char buf[100];
258 
259 	if (statfs(".", &fsbuf) < 0) {
260 		syslog(LOG_ERR, "%s: %m", savedir);
261 		exit(1);
262 	}
263 	spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
264 	totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
265 
266 	if ((fp = fopen("minfree", "r")) == NULL)
267 		minfree = 0;
268 	else {
269 		if (fgets(buf, sizeof(buf), fp) == NULL)
270 			minfree = 0;
271 		else
272 			minfree = atoi(buf);
273 		(void)fclose(fp);
274 	}
275 
276 	needed = dumpsize / 1024 + 2;	/* 2 for info file */
277 	needed -= saved_dump_size(bounds);
278 	if ((minfree > 0 ? spacefree : totfree) - needed < minfree) {
279 		syslog(LOG_WARNING,
280 	"no dump, not enough free space on device (%lld available, need %lld)",
281 		    (long long)(minfree > 0 ? spacefree : totfree),
282 		    (long long)needed);
283 		return (0);
284 	}
285 	if (spacefree - needed < 0)
286 		syslog(LOG_WARNING,
287 		    "dump performed, but free space threshold crossed");
288 	return (1);
289 }
290 
291 #define BLOCKSIZE (1<<12)
292 #define BLOCKMASK (~(BLOCKSIZE-1))
293 
294 static int
295 DoRegularFile(int fd, off_t dumpsize, char *buf, const char *device,
296     const char *filename, FILE *fp)
297 {
298 	int he, hs, nr, nw, wl;
299 	off_t dmpcnt, origsize;
300 
301 	dmpcnt = 0;
302 	origsize = dumpsize;
303 	he = 0;
304 	while (dumpsize > 0) {
305 		wl = BUFFERSIZE;
306 		if (wl > dumpsize)
307 			wl = dumpsize;
308 		nr = read(fd, buf, wl);
309 		if (nr != wl) {
310 			if (nr == 0)
311 				syslog(LOG_WARNING,
312 				    "WARNING: EOF on dump device");
313 			else
314 				syslog(LOG_ERR, "read error on %s: %m", device);
315 			nerr++;
316 			return (-1);
317 		}
318 		if (compress) {
319 			nw = fwrite(buf, 1, wl, fp);
320 		} else {
321 			for (nw = 0; nw < nr; nw = he) {
322 				/* find a contiguous block of zeroes */
323 				for (hs = nw; hs < nr; hs += BLOCKSIZE) {
324 					for (he = hs; he < nr && buf[he] == 0;
325 					    ++he)
326 						/* nothing */ ;
327 					/* is the hole long enough to matter? */
328 					if (he >= hs + BLOCKSIZE)
329 						break;
330 				}
331 
332 				/* back down to a block boundary */
333 				he &= BLOCKMASK;
334 
335 				/*
336 				 * 1) Don't go beyond the end of the buffer.
337 				 * 2) If the end of the buffer is less than
338 				 *    BLOCKSIZE bytes away, we're at the end
339 				 *    of the file, so just grab what's left.
340 				 */
341 				if (hs + BLOCKSIZE > nr)
342 					hs = he = nr;
343 
344 				/*
345 				 * At this point, we have a partial ordering:
346 				 *     nw <= hs <= he <= nr
347 				 * If hs > nw, buf[nw..hs] contains non-zero data.
348 				 * If he > hs, buf[hs..he] is all zeroes.
349 				 */
350 				if (hs > nw)
351 					if (fwrite(buf + nw, hs - nw, 1, fp)
352 					    != 1)
353 					break;
354 				if (he > hs)
355 					if (fseeko(fp, he - hs, SEEK_CUR) == -1)
356 						break;
357 			}
358 		}
359 		if (nw != wl) {
360 			syslog(LOG_ERR,
361 			    "write error on %s file: %m", filename);
362 			syslog(LOG_WARNING,
363 			    "WARNING: vmcore may be incomplete");
364 			nerr++;
365 			return (-1);
366 		}
367 		if (verbose) {
368 			dmpcnt += wl;
369 			printf("%llu\r", (unsigned long long)dmpcnt);
370 			fflush(stdout);
371 		}
372 		dumpsize -= wl;
373 		if (got_siginfo) {
374 			printf("%s %.1lf%%\n", filename, (100.0 - (100.0 *
375 			    (double)dumpsize / (double)origsize)));
376 			got_siginfo = 0;
377 		}
378 	}
379 	return (0);
380 }
381 
382 /*
383  * Specialized version of dump-reading logic for use with textdumps, which
384  * are written backwards from the end of the partition, and must be reversed
385  * before being written to the file.  Textdumps are small, so do a bit less
386  * work to optimize/sparsify.
387  */
388 static int
389 DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
390     const char *device, const char *filename, FILE *fp)
391 {
392 	int nr, nw, wl;
393 	off_t dmpcnt, totsize;
394 
395 	totsize = dumpsize;
396 	dmpcnt = 0;
397 	wl = 512;
398 	if ((dumpsize % wl) != 0) {
399 		syslog(LOG_ERR, "textdump uneven multiple of 512 on %s",
400 		    device);
401 		nerr++;
402 		return (-1);
403 	}
404 	while (dumpsize > 0) {
405 		nr = pread(fd, buf, wl, lasthd - (totsize - dumpsize) - wl);
406 		if (nr != wl) {
407 			if (nr == 0)
408 				syslog(LOG_WARNING,
409 				    "WARNING: EOF on dump device");
410 			else
411 				syslog(LOG_ERR, "read error on %s: %m", device);
412 			nerr++;
413 			return (-1);
414 		}
415 		nw = fwrite(buf, 1, wl, fp);
416 		if (nw != wl) {
417 			syslog(LOG_ERR,
418 			    "write error on %s file: %m", filename);
419 			syslog(LOG_WARNING,
420 			    "WARNING: textdump may be incomplete");
421 			nerr++;
422 			return (-1);
423 		}
424 		if (verbose) {
425 			dmpcnt += wl;
426 			printf("%llu\r", (unsigned long long)dmpcnt);
427 			fflush(stdout);
428 		}
429 		dumpsize -= wl;
430 	}
431 	return (0);
432 }
433 
434 static void
435 DoFile(const char *savedir, const char *device)
436 {
437 	xo_handle_t *xostdout, *xoinfo;
438 	static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
439 	static char *buf = NULL;
440 	char *temp = NULL;
441 	struct kerneldumpheader kdhf, kdhl;
442 	off_t mediasize, dumpsize, firsthd, lasthd;
443 	FILE *info, *fp;
444 	mode_t oumask;
445 	int fd, fdinfo, error;
446 	int bounds, status;
447 	u_int sectorsize, xostyle;
448 	int istextdump;
449 
450 	bounds = getbounds();
451 	mediasize = 0;
452 	status = STATUS_UNKNOWN;
453 
454 	xostdout = xo_create_to_file(stdout, XO_STYLE_TEXT, 0);
455 	if (xostdout == NULL) {
456 		syslog(LOG_ERR, "%s: %m", infoname);
457 		return;
458 	}
459 
460 	if (maxdumps > 0 && bounds == maxdumps)
461 		bounds = 0;
462 
463 	if (buf == NULL) {
464 		buf = malloc(BUFFERSIZE);
465 		if (buf == NULL) {
466 			syslog(LOG_ERR, "%m");
467 			return;
468 		}
469 	}
470 
471 	if (verbose)
472 		printf("checking for kernel dump on device %s\n", device);
473 
474 	fd = open(device, (checkfor || keep) ? O_RDONLY : O_RDWR);
475 	if (fd < 0) {
476 		syslog(LOG_ERR, "%s: %m", device);
477 		return;
478 	}
479 
480 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
481 	if (!error)
482 		error = ioctl(fd, DIOCGSECTORSIZE, &sectorsize);
483 	if (error) {
484 		syslog(LOG_ERR,
485 		    "couldn't find media and/or sector size of %s: %m", device);
486 		goto closefd;
487 	}
488 
489 	if (verbose) {
490 		printf("mediasize = %lld\n", (long long)mediasize);
491 		printf("sectorsize = %u\n", sectorsize);
492 	}
493 
494 	if (sectorsize < sizeof(kdhl)) {
495 		syslog(LOG_ERR,
496 		    "Sector size is less the kernel dump header %zu",
497 		    sizeof(kdhl));
498 		goto closefd;
499 	}
500 
501 	lasthd = mediasize - sectorsize;
502 	temp = malloc(sectorsize);
503 	if (temp == NULL) {
504 		syslog(LOG_ERR, "%m");
505 		goto closefd;
506 	}
507 	if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
508 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
509 		syslog(LOG_ERR,
510 		    "error reading last dump header at offset %lld in %s: %m",
511 		    (long long)lasthd, device);
512 		goto closefd;
513 	}
514 	memcpy(&kdhl, temp, sizeof(kdhl));
515 	istextdump = 0;
516 	if (strncmp(kdhl.magic, TEXTDUMPMAGIC, sizeof kdhl) == 0) {
517 		if (verbose)
518 			printf("textdump magic on last dump header on %s\n",
519 			    device);
520 		istextdump = 1;
521 		if (dtoh32(kdhl.version) != KERNELDUMP_TEXT_VERSION) {
522 			syslog(LOG_ERR,
523 			    "unknown version (%d) in last dump header on %s",
524 			    dtoh32(kdhl.version), device);
525 
526 			status = STATUS_BAD;
527 			if (force == 0)
528 				goto closefd;
529 		}
530 	} else if (memcmp(kdhl.magic, KERNELDUMPMAGIC, sizeof kdhl.magic) ==
531 	    0) {
532 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
533 			syslog(LOG_ERR,
534 			    "unknown version (%d) in last dump header on %s",
535 			    dtoh32(kdhl.version), device);
536 
537 			status = STATUS_BAD;
538 			if (force == 0)
539 				goto closefd;
540 		}
541 	} else {
542 		if (verbose)
543 			printf("magic mismatch on last dump header on %s\n",
544 			    device);
545 
546 		status = STATUS_BAD;
547 		if (force == 0)
548 			goto closefd;
549 
550 		if (memcmp(kdhl.magic, KERNELDUMPMAGIC_CLEARED,
551 			    sizeof kdhl.magic) == 0) {
552 			if (verbose)
553 				printf("forcing magic on %s\n", device);
554 			memcpy(kdhl.magic, KERNELDUMPMAGIC,
555 			    sizeof kdhl.magic);
556 		} else {
557 			syslog(LOG_ERR, "unable to force dump - bad magic");
558 			goto closefd;
559 		}
560 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
561 			syslog(LOG_ERR,
562 			    "unknown version (%d) in last dump header on %s",
563 			    dtoh32(kdhl.version), device);
564 
565 			status = STATUS_BAD;
566 			if (force == 0)
567 				goto closefd;
568 		}
569 	}
570 
571 	nfound++;
572 	if (clear)
573 		goto nuke;
574 
575 	if (kerneldump_parity(&kdhl)) {
576 		syslog(LOG_ERR,
577 		    "parity error on last dump header on %s", device);
578 		nerr++;
579 		status = STATUS_BAD;
580 		if (force == 0)
581 			goto closefd;
582 	}
583 	dumpsize = dtoh64(kdhl.dumplength);
584 	firsthd = lasthd - dumpsize - sectorsize;
585 	if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
586 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
587 		syslog(LOG_ERR,
588 		    "error reading first dump header at offset %lld in %s: %m",
589 		    (long long)firsthd, device);
590 		nerr++;
591 		goto closefd;
592 	}
593 	memcpy(&kdhf, temp, sizeof(kdhf));
594 
595 	if (verbose >= 2) {
596 		printf("First dump headers:\n");
597 		printheader(xostdout, &kdhf, device, bounds, -1);
598 
599 		printf("\nLast dump headers:\n");
600 		printheader(xostdout, &kdhl, device, bounds, -1);
601 		printf("\n");
602 	}
603 
604 	if (memcmp(&kdhl, &kdhf, sizeof(kdhl))) {
605 		syslog(LOG_ERR,
606 		    "first and last dump headers disagree on %s", device);
607 		nerr++;
608 		status = STATUS_BAD;
609 		if (force == 0)
610 			goto closefd;
611 	} else {
612 		status = STATUS_GOOD;
613 	}
614 
615 	if (checkfor) {
616 		printf("A dump exists on %s\n", device);
617 		close(fd);
618 		exit(0);
619 	}
620 
621 	if (kdhl.panicstring[0] != '\0')
622 		syslog(LOG_ALERT, "reboot after panic: %*s",
623 		    (int)sizeof(kdhl.panicstring), kdhl.panicstring);
624 	else
625 		syslog(LOG_ALERT, "reboot");
626 
627 	if (verbose)
628 		printf("Checking for available free space\n");
629 
630 	if (!check_space(savedir, dumpsize, bounds)) {
631 		nerr++;
632 		goto closefd;
633 	}
634 
635 	writebounds(bounds + 1);
636 
637 	saved_dump_remove(bounds);
638 
639 	snprintf(infoname, sizeof(infoname), "info.%d", bounds);
640 
641 	/*
642 	 * Create or overwrite any existing dump header files.
643 	 */
644 	fdinfo = open(infoname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
645 	if (fdinfo < 0) {
646 		syslog(LOG_ERR, "%s: %m", infoname);
647 		nerr++;
648 		goto closefd;
649 	}
650 
651 	oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
652 	if (compress) {
653 		snprintf(corename, sizeof(corename), "%s.%d.gz",
654 		    istextdump ? "textdump.tar" : "vmcore", bounds);
655 		fp = zopen(corename, "w");
656 	} else {
657 		snprintf(corename, sizeof(corename), "%s.%d",
658 		    istextdump ? "textdump.tar" : "vmcore", bounds);
659 		fp = fopen(corename, "w");
660 	}
661 	if (fp == NULL) {
662 		syslog(LOG_ERR, "%s: %m", corename);
663 		close(fdinfo);
664 		nerr++;
665 		goto closefd;
666 	}
667 	(void)umask(oumask);
668 
669 	info = fdopen(fdinfo, "w");
670 
671 	if (info == NULL) {
672 		syslog(LOG_ERR, "fdopen failed: %m");
673 		nerr++;
674 		goto closeall;
675 	}
676 
677 	xostyle = xo_get_style(NULL);
678 	xoinfo = xo_create_to_file(info, xostyle, 0);
679 	if (xoinfo == NULL) {
680 		syslog(LOG_ERR, "%s: %m", infoname);
681 		nerr++;
682 		goto closeall;
683 	}
684 	xo_open_container_h(xoinfo, "crashdump");
685 
686 	if (verbose)
687 		printheader(xostdout, &kdhl, device, bounds, status);
688 
689 	printheader(xoinfo, &kdhl, device, bounds, status);
690 	xo_close_container_h(xoinfo, "crashdump");
691 	xo_flush_h(xoinfo);
692 	xo_finish_h(xoinfo);
693 	fclose(info);
694 
695 	syslog(LOG_NOTICE, "writing %score to %s/%s",
696 	    compress ? "compressed " : "", savedir, corename);
697 
698 	if (istextdump) {
699 		if (DoTextdumpFile(fd, dumpsize, lasthd, buf, device,
700 		    corename, fp) < 0)
701 			goto closeall;
702 	} else {
703 		if (DoRegularFile(fd, dumpsize, buf, device, corename, fp)
704 		    < 0)
705 			goto closeall;
706 	}
707 	if (verbose)
708 		printf("\n");
709 
710 	if (fclose(fp) < 0) {
711 		syslog(LOG_ERR, "error on %s: %m", corename);
712 		nerr++;
713 		goto closefd;
714 	}
715 
716 	symlinks_remove();
717 	if (symlink(infoname, "info.last") == -1) {
718 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
719 		    savedir, "info.last");
720 	}
721 	if (compress) {
722 		snprintf(linkname, sizeof(linkname), "%s.last.gz",
723 		    istextdump ? "textdump.tar" : "vmcore");
724 	} else {
725 		snprintf(linkname, sizeof(linkname), "%s.last",
726 		    istextdump ? "textdump.tar" : "vmcore");
727 	}
728 	if (symlink(corename, linkname) == -1) {
729 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
730 		    savedir, linkname);
731 	}
732 
733 	nsaved++;
734 
735 	if (verbose)
736 		printf("dump saved\n");
737 
738 nuke:
739 	if (!keep) {
740 		if (verbose)
741 			printf("clearing dump header\n");
742 		memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof(kdhl.magic));
743 		memcpy(temp, &kdhl, sizeof(kdhl));
744 		if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
745 		    write(fd, temp, sectorsize) != (ssize_t)sectorsize)
746 			syslog(LOG_ERR,
747 			    "error while clearing the dump header: %m");
748 	}
749 	xo_close_container_h(xostdout, "crashdump");
750 	xo_finish_h(xostdout);
751 	free(temp);
752 	close(fd);
753 	return;
754 
755 closeall:
756 	fclose(fp);
757 
758 closefd:
759 	free(temp);
760 	close(fd);
761 }
762 
763 static void
764 usage(void)
765 {
766 	xo_error("%s\n%s\n%s\n",
767 	    "usage: savecore -c [-v] [device ...]",
768 	    "       savecore -C [-v] [device ...]",
769 	    "       savecore [-fkvz] [-m maxdumps] [directory [device ...]]");
770 	exit(1);
771 }
772 
773 int
774 main(int argc, char **argv)
775 {
776 	const char *savedir = ".";
777 	struct fstab *fsp;
778 	int i, ch, error;
779 
780 	checkfor = compress = clear = force = keep = verbose = 0;
781 	nfound = nsaved = nerr = 0;
782 
783 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
784 	signal(SIGINFO, infohandler);
785 
786 	argc = xo_parse_args(argc, argv);
787 	if (argc < 0)
788 		exit(1);
789 
790 	while ((ch = getopt(argc, argv, "Ccfkm:vz")) != -1)
791 		switch(ch) {
792 		case 'C':
793 			checkfor = 1;
794 			break;
795 		case 'c':
796 			clear = 1;
797 			break;
798 		case 'f':
799 			force = 1;
800 			break;
801 		case 'k':
802 			keep = 1;
803 			break;
804 		case 'm':
805 			maxdumps = atoi(optarg);
806 			if (maxdumps <= 0) {
807 				syslog(LOG_ERR, "Invalid maxdump value");
808 				exit(1);
809 			}
810 			break;
811 		case 'v':
812 			verbose++;
813 			break;
814 		case 'z':
815 			compress = 1;
816 			break;
817 		case '?':
818 		default:
819 			usage();
820 		}
821 	if (checkfor && (clear || force || keep))
822 		usage();
823 	if (clear && (compress || keep))
824 		usage();
825 	if (maxdumps > 0 && (checkfor || clear))
826 		usage();
827 	argc -= optind;
828 	argv += optind;
829 	if (argc >= 1 && !checkfor && !clear) {
830 		error = chdir(argv[0]);
831 		if (error) {
832 			syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
833 			exit(1);
834 		}
835 		savedir = argv[0];
836 		argc--;
837 		argv++;
838 	}
839 	if (argc == 0) {
840 		for (;;) {
841 			fsp = getfsent();
842 			if (fsp == NULL)
843 				break;
844 			if (strcmp(fsp->fs_vfstype, "swap") &&
845 			    strcmp(fsp->fs_vfstype, "dump"))
846 				continue;
847 			DoFile(savedir, fsp->fs_spec);
848 		}
849 		endfsent();
850 	} else {
851 		for (i = 0; i < argc; i++)
852 			DoFile(savedir, argv[i]);
853 	}
854 
855 	/* Emit minimal output. */
856 	if (nfound == 0) {
857 		if (checkfor) {
858 			if (verbose)
859 				printf("No dump exists\n");
860 			exit(1);
861 		}
862 		if (verbose)
863 			syslog(LOG_WARNING, "no dumps found");
864 	} else if (nsaved == 0) {
865 		if (nerr != 0) {
866 			if (verbose)
867 				syslog(LOG_WARNING, "unsaved dumps found but not saved");
868 			exit(1);
869 		} else if (verbose)
870 			syslog(LOG_WARNING, "no unsaved dumps found");
871 	}
872 
873 	return (0);
874 }
875 
876 static void
877 infohandler(int sig __unused)
878 {
879 	got_siginfo = 1;
880 }
881