xref: /freebsd/sbin/savecore/savecore.c (revision d6b92ffa990dc57d8a969a98e3ca4e25ba39cbb2)
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  * 3. 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 <ctype.h>
72 #include <errno.h>
73 #include <fcntl.h>
74 #include <fstab.h>
75 #include <paths.h>
76 #include <signal.h>
77 #include <stdarg.h>
78 #include <stdbool.h>
79 #include <stdio.h>
80 #include <stdlib.h>
81 #include <string.h>
82 #include <syslog.h>
83 #include <time.h>
84 #include <unistd.h>
85 #include <libxo/xo.h>
86 
87 /* The size of the buffer used for I/O. */
88 #define	BUFFERSIZE	(1024*1024)
89 
90 #define	STATUS_BAD	0
91 #define	STATUS_GOOD	1
92 #define	STATUS_UNKNOWN	2
93 
94 static int checkfor, compress, clear, force, keep, verbose;	/* flags */
95 static int nfound, nsaved, nerr;			/* statistics */
96 static int maxdumps;
97 
98 extern FILE *zopen(const char *, const char *);
99 
100 static sig_atomic_t got_siginfo;
101 static void infohandler(int);
102 
103 static void
104 printheader(xo_handle_t *xo, const struct kerneldumpheader *h, const char *device,
105     int bounds, const int status)
106 {
107 	uint64_t dumplen;
108 	time_t t;
109 	const char *stat_str;
110 
111 	xo_flush_h(xo);
112 	xo_emit_h(xo, "{Lwc:Dump header from device}{:dump_device/%s}\n", device);
113 	xo_emit_h(xo, "{P:  }{Lwc:Architecture}{:architecture/%s}\n", h->architecture);
114 	xo_emit_h(xo, "{P:  }{Lwc:Architecture Version}{:architecture_version/%u}\n", dtoh32(h->architectureversion));
115 	dumplen = dtoh64(h->dumplength);
116 	xo_emit_h(xo, "{P:  }{Lwc:Dump Length}{:dump_length_bytes/%lld}\n", (long long)dumplen);
117 	xo_emit_h(xo, "{P:  }{Lwc:Blocksize}{:blocksize/%d}\n", dtoh32(h->blocksize));
118 	t = dtoh64(h->dumptime);
119 	xo_emit_h(xo, "{P:  }{Lwc:Dumptime}{:dumptime/%s}", ctime(&t));
120 	xo_emit_h(xo, "{P:  }{Lwc:Hostname}{:hostname/%s}\n", h->hostname);
121 	xo_emit_h(xo, "{P:  }{Lwc:Magic}{:magic/%s}\n", h->magic);
122 	xo_emit_h(xo, "{P:  }{Lwc:Version String}{:version_string/%s}", h->versionstring);
123 	xo_emit_h(xo, "{P:  }{Lwc:Panic String}{:panic_string/%s}\n", h->panicstring);
124 	xo_emit_h(xo, "{P:  }{Lwc:Dump Parity}{:dump_parity/%u}\n", h->parity);
125 	xo_emit_h(xo, "{P:  }{Lwc:Bounds}{:bounds/%d}\n", bounds);
126 
127 	switch(status) {
128 	case STATUS_BAD:
129 		stat_str = "bad";
130 		break;
131 	case STATUS_GOOD:
132 		stat_str = "good";
133 		break;
134 	default:
135 		stat_str = "unknown";
136 	}
137 	xo_emit_h(xo, "{P:  }{Lwc:Dump Status}{:dump_status/%s}\n", stat_str);
138 	xo_flush_h(xo);
139 }
140 
141 static int
142 getbounds(void) {
143 	FILE *fp;
144 	char buf[6];
145 	int ret;
146 
147 	ret = 0;
148 
149 	if ((fp = fopen("bounds", "r")) == NULL) {
150 		if (verbose)
151 			printf("unable to open bounds file, using 0\n");
152 		return (ret);
153 	}
154 
155 	if (fgets(buf, sizeof buf, fp) == NULL) {
156 		if (feof(fp))
157 			syslog(LOG_WARNING, "bounds file is empty, using 0");
158 		else
159 			syslog(LOG_WARNING, "bounds file: %s", strerror(errno));
160 		fclose(fp);
161 		return (ret);
162 	}
163 
164 	errno = 0;
165 	ret = (int)strtol(buf, NULL, 10);
166 	if (ret == 0 && (errno == EINVAL || errno == ERANGE))
167 		syslog(LOG_WARNING, "invalid value found in bounds, using 0");
168 	fclose(fp);
169 	return (ret);
170 }
171 
172 static void
173 writebounds(int bounds) {
174 	FILE *fp;
175 
176 	if ((fp = fopen("bounds", "w")) == NULL) {
177 		syslog(LOG_WARNING, "unable to write to bounds file: %m");
178 		return;
179 	}
180 
181 	if (verbose)
182 		printf("bounds number: %d\n", bounds);
183 
184 	fprintf(fp, "%d\n", bounds);
185 	fclose(fp);
186 }
187 
188 static bool
189 writekey(const char *keyname, uint8_t *dumpkey, uint32_t dumpkeysize)
190 {
191 	int fd;
192 
193 	fd = open(keyname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
194 	if (fd == -1) {
195 		syslog(LOG_ERR, "Unable to open %s to write the key: %m.",
196 		    keyname);
197 		return (false);
198 	}
199 
200 	if (write(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
201 		syslog(LOG_ERR, "Unable to write the key to %s: %m.", keyname);
202 		close(fd);
203 		return (false);
204 	}
205 
206 	close(fd);
207 	return (true);
208 }
209 
210 static off_t
211 file_size(const char *path)
212 {
213 	struct stat sb;
214 
215 	/* Ignore all errors, those file may not exists. */
216 	if (stat(path, &sb) == -1)
217 		return (0);
218 	return (sb.st_size);
219 }
220 
221 static off_t
222 saved_dump_size(int bounds)
223 {
224 	static char path[PATH_MAX];
225 	off_t dumpsize;
226 
227 	dumpsize = 0;
228 
229 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
230 	dumpsize += file_size(path);
231 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
232 	dumpsize += file_size(path);
233 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
234 	dumpsize += file_size(path);
235 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
236 	dumpsize += file_size(path);
237 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
238 	dumpsize += file_size(path);
239 
240 	return (dumpsize);
241 }
242 
243 static void
244 saved_dump_remove(int bounds)
245 {
246 	static char path[PATH_MAX];
247 
248 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
249 	(void)unlink(path);
250 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
251 	(void)unlink(path);
252 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
253 	(void)unlink(path);
254 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
255 	(void)unlink(path);
256 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
257 	(void)unlink(path);
258 }
259 
260 static void
261 symlinks_remove(void)
262 {
263 
264 	(void)unlink("info.last");
265 	(void)unlink("key.last");
266 	(void)unlink("vmcore.last");
267 	(void)unlink("vmcore.last.gz");
268 	(void)unlink("vmcore_encrypted.last");
269 	(void)unlink("vmcore_encrypted.last.gz");
270 	(void)unlink("textdump.tar.last");
271 	(void)unlink("textdump.tar.last.gz");
272 }
273 
274 /*
275  * Check that sufficient space is available on the disk that holds the
276  * save directory.
277  */
278 static int
279 check_space(const char *savedir, off_t dumpsize, int bounds)
280 {
281 	FILE *fp;
282 	off_t available, minfree, spacefree, totfree, needed;
283 	struct statfs fsbuf;
284 	char buf[100];
285 
286 	if (statfs(".", &fsbuf) < 0) {
287 		syslog(LOG_ERR, "%s: %m", savedir);
288 		exit(1);
289 	}
290 	spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
291 	totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
292 
293 	if ((fp = fopen("minfree", "r")) == NULL)
294 		minfree = 0;
295 	else {
296 		if (fgets(buf, sizeof(buf), fp) == NULL)
297 			minfree = 0;
298 		else {
299 			char *endp;
300 
301 			errno = 0;
302 			minfree = strtoll(buf, &endp, 10);
303 			if (minfree == 0 && errno != 0)
304 				minfree = -1;
305 			else {
306 				while (*endp != '\0' && isspace(*endp))
307 					endp++;
308 				if (*endp != '\0' || minfree < 0)
309 					minfree = -1;
310 			}
311 			if (minfree < 0)
312 				syslog(LOG_WARNING,
313 				    "`minfree` didn't contain a valid size "
314 				    "(`%s`). Defaulting to 0", buf);
315 		}
316 		(void)fclose(fp);
317 	}
318 
319 	available = minfree > 0 ? spacefree - minfree : totfree;
320 	needed = dumpsize / 1024 + 2;	/* 2 for info file */
321 	needed -= saved_dump_size(bounds);
322 	if (available < needed) {
323 		syslog(LOG_WARNING,
324 		    "no dump: not enough free space on device (need at least "
325 		    "%jdkB for dump; %jdkB available; %jdkB reserved)",
326 		    (intmax_t)needed,
327 		    (intmax_t)available + minfree,
328 		    (intmax_t)minfree);
329 		return (0);
330 	}
331 	if (spacefree - needed < 0)
332 		syslog(LOG_WARNING,
333 		    "dump performed, but free space threshold crossed");
334 	return (1);
335 }
336 
337 static bool
338 compare_magic(const struct kerneldumpheader *kdh, const char *magic)
339 {
340 
341 	return (strncmp(kdh->magic, magic, sizeof(kdh->magic)) == 0);
342 }
343 
344 #define BLOCKSIZE (1<<12)
345 #define BLOCKMASK (~(BLOCKSIZE-1))
346 
347 static int
348 DoRegularFile(int fd, bool isencrypted, off_t dumpsize, char *buf,
349     const char *device, const char *filename, FILE *fp)
350 {
351 	int he, hs, nr, nw, wl;
352 	off_t dmpcnt, origsize;
353 
354 	dmpcnt = 0;
355 	origsize = dumpsize;
356 	he = 0;
357 	while (dumpsize > 0) {
358 		wl = BUFFERSIZE;
359 		if (wl > dumpsize)
360 			wl = dumpsize;
361 		nr = read(fd, buf, wl);
362 		if (nr != wl) {
363 			if (nr == 0)
364 				syslog(LOG_WARNING,
365 				    "WARNING: EOF on dump device");
366 			else
367 				syslog(LOG_ERR, "read error on %s: %m", device);
368 			nerr++;
369 			return (-1);
370 		}
371 		if (compress || isencrypted) {
372 			nw = fwrite(buf, 1, wl, fp);
373 		} else {
374 			for (nw = 0; nw < nr; nw = he) {
375 				/* find a contiguous block of zeroes */
376 				for (hs = nw; hs < nr; hs += BLOCKSIZE) {
377 					for (he = hs; he < nr && buf[he] == 0;
378 					    ++he)
379 						/* nothing */ ;
380 					/* is the hole long enough to matter? */
381 					if (he >= hs + BLOCKSIZE)
382 						break;
383 				}
384 
385 				/* back down to a block boundary */
386 				he &= BLOCKMASK;
387 
388 				/*
389 				 * 1) Don't go beyond the end of the buffer.
390 				 * 2) If the end of the buffer is less than
391 				 *    BLOCKSIZE bytes away, we're at the end
392 				 *    of the file, so just grab what's left.
393 				 */
394 				if (hs + BLOCKSIZE > nr)
395 					hs = he = nr;
396 
397 				/*
398 				 * At this point, we have a partial ordering:
399 				 *     nw <= hs <= he <= nr
400 				 * If hs > nw, buf[nw..hs] contains non-zero data.
401 				 * If he > hs, buf[hs..he] is all zeroes.
402 				 */
403 				if (hs > nw)
404 					if (fwrite(buf + nw, hs - nw, 1, fp)
405 					    != 1)
406 					break;
407 				if (he > hs)
408 					if (fseeko(fp, he - hs, SEEK_CUR) == -1)
409 						break;
410 			}
411 		}
412 		if (nw != wl) {
413 			syslog(LOG_ERR,
414 			    "write error on %s file: %m", filename);
415 			syslog(LOG_WARNING,
416 			    "WARNING: vmcore may be incomplete");
417 			nerr++;
418 			return (-1);
419 		}
420 		if (verbose) {
421 			dmpcnt += wl;
422 			printf("%llu\r", (unsigned long long)dmpcnt);
423 			fflush(stdout);
424 		}
425 		dumpsize -= wl;
426 		if (got_siginfo) {
427 			printf("%s %.1lf%%\n", filename, (100.0 - (100.0 *
428 			    (double)dumpsize / (double)origsize)));
429 			got_siginfo = 0;
430 		}
431 	}
432 	return (0);
433 }
434 
435 /*
436  * Specialized version of dump-reading logic for use with textdumps, which
437  * are written backwards from the end of the partition, and must be reversed
438  * before being written to the file.  Textdumps are small, so do a bit less
439  * work to optimize/sparsify.
440  */
441 static int
442 DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
443     const char *device, const char *filename, FILE *fp)
444 {
445 	int nr, nw, wl;
446 	off_t dmpcnt, totsize;
447 
448 	totsize = dumpsize;
449 	dmpcnt = 0;
450 	wl = 512;
451 	if ((dumpsize % wl) != 0) {
452 		syslog(LOG_ERR, "textdump uneven multiple of 512 on %s",
453 		    device);
454 		nerr++;
455 		return (-1);
456 	}
457 	while (dumpsize > 0) {
458 		nr = pread(fd, buf, wl, lasthd - (totsize - dumpsize) - wl);
459 		if (nr != wl) {
460 			if (nr == 0)
461 				syslog(LOG_WARNING,
462 				    "WARNING: EOF on dump device");
463 			else
464 				syslog(LOG_ERR, "read error on %s: %m", device);
465 			nerr++;
466 			return (-1);
467 		}
468 		nw = fwrite(buf, 1, wl, fp);
469 		if (nw != wl) {
470 			syslog(LOG_ERR,
471 			    "write error on %s file: %m", filename);
472 			syslog(LOG_WARNING,
473 			    "WARNING: textdump may be incomplete");
474 			nerr++;
475 			return (-1);
476 		}
477 		if (verbose) {
478 			dmpcnt += wl;
479 			printf("%llu\r", (unsigned long long)dmpcnt);
480 			fflush(stdout);
481 		}
482 		dumpsize -= wl;
483 	}
484 	return (0);
485 }
486 
487 static void
488 DoFile(const char *savedir, const char *device)
489 {
490 	xo_handle_t *xostdout, *xoinfo;
491 	static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
492 	static char keyname[PATH_MAX];
493 	static char *buf = NULL;
494 	char *temp = NULL;
495 	struct kerneldumpheader kdhf, kdhl;
496 	uint8_t *dumpkey;
497 	off_t mediasize, dumpsize, firsthd, lasthd;
498 	FILE *info, *fp;
499 	mode_t oumask;
500 	int fd, fdinfo, error;
501 	int bounds, status;
502 	u_int sectorsize, xostyle;
503 	int istextdump;
504 	uint32_t dumpkeysize;
505 	bool isencrypted, ret;
506 
507 	bounds = getbounds();
508 	dumpkey = NULL;
509 	mediasize = 0;
510 	status = STATUS_UNKNOWN;
511 
512 	xostdout = xo_create_to_file(stdout, XO_STYLE_TEXT, 0);
513 	if (xostdout == NULL) {
514 		syslog(LOG_ERR, "%s: %m", infoname);
515 		return;
516 	}
517 
518 	if (maxdumps > 0 && bounds == maxdumps)
519 		bounds = 0;
520 
521 	if (buf == NULL) {
522 		buf = malloc(BUFFERSIZE);
523 		if (buf == NULL) {
524 			syslog(LOG_ERR, "%m");
525 			return;
526 		}
527 	}
528 
529 	if (verbose)
530 		printf("checking for kernel dump on device %s\n", device);
531 
532 	fd = open(device, (checkfor || keep) ? O_RDONLY : O_RDWR);
533 	if (fd < 0) {
534 		syslog(LOG_ERR, "%s: %m", device);
535 		return;
536 	}
537 
538 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
539 	if (!error)
540 		error = ioctl(fd, DIOCGSECTORSIZE, &sectorsize);
541 	if (error) {
542 		syslog(LOG_ERR,
543 		    "couldn't find media and/or sector size of %s: %m", device);
544 		goto closefd;
545 	}
546 
547 	if (verbose) {
548 		printf("mediasize = %lld bytes\n", (long long)mediasize);
549 		printf("sectorsize = %u bytes\n", sectorsize);
550 	}
551 
552 	if (sectorsize < sizeof(kdhl)) {
553 		syslog(LOG_ERR,
554 		    "Sector size is less the kernel dump header %zu",
555 		    sizeof(kdhl));
556 		goto closefd;
557 	}
558 
559 	lasthd = mediasize - sectorsize;
560 	temp = malloc(sectorsize);
561 	if (temp == NULL) {
562 		syslog(LOG_ERR, "%m");
563 		goto closefd;
564 	}
565 	if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
566 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
567 		syslog(LOG_ERR,
568 		    "error reading last dump header at offset %lld in %s: %m",
569 		    (long long)lasthd, device);
570 		goto closefd;
571 	}
572 	memcpy(&kdhl, temp, sizeof(kdhl));
573 	istextdump = 0;
574 	if (compare_magic(&kdhl, TEXTDUMPMAGIC)) {
575 		if (verbose)
576 			printf("textdump magic on last dump header on %s\n",
577 			    device);
578 		istextdump = 1;
579 		if (dtoh32(kdhl.version) != KERNELDUMP_TEXT_VERSION) {
580 			syslog(LOG_ERR,
581 			    "unknown version (%d) in last dump header on %s",
582 			    dtoh32(kdhl.version), device);
583 
584 			status = STATUS_BAD;
585 			if (force == 0)
586 				goto closefd;
587 		}
588 	} else if (compare_magic(&kdhl, KERNELDUMPMAGIC)) {
589 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
590 			syslog(LOG_ERR,
591 			    "unknown version (%d) in last dump header on %s",
592 			    dtoh32(kdhl.version), device);
593 
594 			status = STATUS_BAD;
595 			if (force == 0)
596 				goto closefd;
597 		}
598 	} else {
599 		if (verbose)
600 			printf("magic mismatch on last dump header on %s\n",
601 			    device);
602 
603 		status = STATUS_BAD;
604 		if (force == 0)
605 			goto closefd;
606 
607 		if (compare_magic(&kdhl, KERNELDUMPMAGIC_CLEARED)) {
608 			if (verbose)
609 				printf("forcing magic on %s\n", device);
610 			memcpy(kdhl.magic, KERNELDUMPMAGIC,
611 			    sizeof kdhl.magic);
612 		} else {
613 			syslog(LOG_ERR, "unable to force dump - bad magic");
614 			goto closefd;
615 		}
616 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
617 			syslog(LOG_ERR,
618 			    "unknown version (%d) in last dump header on %s",
619 			    dtoh32(kdhl.version), device);
620 
621 			status = STATUS_BAD;
622 			if (force == 0)
623 				goto closefd;
624 		}
625 	}
626 
627 	nfound++;
628 	if (clear)
629 		goto nuke;
630 
631 	if (kerneldump_parity(&kdhl)) {
632 		syslog(LOG_ERR,
633 		    "parity error on last dump header on %s", device);
634 		nerr++;
635 		status = STATUS_BAD;
636 		if (force == 0)
637 			goto closefd;
638 	}
639 	dumpsize = dtoh64(kdhl.dumplength);
640 	dumpkeysize = dtoh32(kdhl.dumpkeysize);
641 	firsthd = lasthd - dumpsize - sectorsize - dumpkeysize;
642 	if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
643 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
644 		syslog(LOG_ERR,
645 		    "error reading first dump header at offset %lld in %s: %m",
646 		    (long long)firsthd, device);
647 		nerr++;
648 		goto closefd;
649 	}
650 	memcpy(&kdhf, temp, sizeof(kdhf));
651 
652 	if (verbose >= 2) {
653 		printf("First dump headers:\n");
654 		printheader(xostdout, &kdhf, device, bounds, -1);
655 
656 		printf("\nLast dump headers:\n");
657 		printheader(xostdout, &kdhl, device, bounds, -1);
658 		printf("\n");
659 	}
660 
661 	if (memcmp(&kdhl, &kdhf, sizeof(kdhl))) {
662 		syslog(LOG_ERR,
663 		    "first and last dump headers disagree on %s", device);
664 		nerr++;
665 		status = STATUS_BAD;
666 		if (force == 0)
667 			goto closefd;
668 	} else {
669 		status = STATUS_GOOD;
670 	}
671 
672 	if (checkfor) {
673 		printf("A dump exists on %s\n", device);
674 		close(fd);
675 		exit(0);
676 	}
677 
678 	if (kdhl.panicstring[0] != '\0')
679 		syslog(LOG_ALERT, "reboot after panic: %.*s",
680 		    (int)sizeof(kdhl.panicstring), kdhl.panicstring);
681 	else
682 		syslog(LOG_ALERT, "reboot");
683 
684 	if (verbose)
685 		printf("Checking for available free space\n");
686 
687 	if (!check_space(savedir, dumpsize, bounds)) {
688 		nerr++;
689 		goto closefd;
690 	}
691 
692 	writebounds(bounds + 1);
693 
694 	saved_dump_remove(bounds);
695 
696 	snprintf(infoname, sizeof(infoname), "info.%d", bounds);
697 
698 	/*
699 	 * Create or overwrite any existing dump header files.
700 	 */
701 	fdinfo = open(infoname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
702 	if (fdinfo < 0) {
703 		syslog(LOG_ERR, "%s: %m", infoname);
704 		nerr++;
705 		goto closefd;
706 	}
707 
708 	oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
709 	isencrypted = (dumpkeysize > 0);
710 	if (compress) {
711 		snprintf(corename, sizeof(corename), "%s.%d.gz",
712 		    istextdump ? "textdump.tar" :
713 		    (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
714 		fp = zopen(corename, "w");
715 	} else {
716 		snprintf(corename, sizeof(corename), "%s.%d",
717 		    istextdump ? "textdump.tar" :
718 		    (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
719 		fp = fopen(corename, "w");
720 	}
721 	if (fp == NULL) {
722 		syslog(LOG_ERR, "%s: %m", corename);
723 		close(fdinfo);
724 		nerr++;
725 		goto closefd;
726 	}
727 	(void)umask(oumask);
728 
729 	info = fdopen(fdinfo, "w");
730 
731 	if (info == NULL) {
732 		syslog(LOG_ERR, "fdopen failed: %m");
733 		nerr++;
734 		goto closeall;
735 	}
736 
737 	xostyle = xo_get_style(NULL);
738 	xoinfo = xo_create_to_file(info, xostyle, 0);
739 	if (xoinfo == NULL) {
740 		syslog(LOG_ERR, "%s: %m", infoname);
741 		nerr++;
742 		goto closeall;
743 	}
744 	xo_open_container_h(xoinfo, "crashdump");
745 
746 	if (verbose)
747 		printheader(xostdout, &kdhl, device, bounds, status);
748 
749 	printheader(xoinfo, &kdhl, device, bounds, status);
750 	xo_close_container_h(xoinfo, "crashdump");
751 	xo_flush_h(xoinfo);
752 	xo_finish_h(xoinfo);
753 	fclose(info);
754 
755 	if (isencrypted) {
756 		dumpkey = calloc(1, dumpkeysize);
757 		if (dumpkey == NULL) {
758 			syslog(LOG_ERR, "Unable to allocate kernel dump key.");
759 			nerr++;
760 			goto closeall;
761 		}
762 
763 		if (read(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
764 			syslog(LOG_ERR, "Unable to read kernel dump key: %m.");
765 			nerr++;
766 			goto closeall;
767 		}
768 
769 		snprintf(keyname, sizeof(keyname), "key.%d", bounds);
770 		ret = writekey(keyname, dumpkey, dumpkeysize);
771 		explicit_bzero(dumpkey, dumpkeysize);
772 		if (!ret) {
773 			nerr++;
774 			goto closeall;
775 		}
776 	}
777 
778 	syslog(LOG_NOTICE, "writing %s%score to %s/%s",
779 	    isencrypted ? "encrypted " : "", compress ? "compressed " : "",
780 	    savedir, corename);
781 
782 	if (istextdump) {
783 		if (DoTextdumpFile(fd, dumpsize, lasthd, buf, device,
784 		    corename, fp) < 0)
785 			goto closeall;
786 	} else {
787 		if (DoRegularFile(fd, isencrypted, dumpsize, buf, device,
788 		    corename, fp) < 0) {
789 			goto closeall;
790 		}
791 	}
792 	if (verbose)
793 		printf("\n");
794 
795 	if (fclose(fp) < 0) {
796 		syslog(LOG_ERR, "error on %s: %m", corename);
797 		nerr++;
798 		goto closefd;
799 	}
800 
801 	symlinks_remove();
802 	if (symlink(infoname, "info.last") == -1) {
803 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
804 		    savedir, "info.last");
805 	}
806 	if (isencrypted) {
807 		if (symlink(keyname, "key.last") == -1) {
808 			syslog(LOG_WARNING,
809 			    "unable to create symlink %s/%s: %m", savedir,
810 			    "key.last");
811 		}
812 	}
813 	if (compress) {
814 		snprintf(linkname, sizeof(linkname), "%s.last.gz",
815 		    istextdump ? "textdump.tar" :
816 		    (isencrypted ? "vmcore_encrypted" : "vmcore"));
817 	} else {
818 		snprintf(linkname, sizeof(linkname), "%s.last",
819 		    istextdump ? "textdump.tar" :
820 		    (isencrypted ? "vmcore_encrypted" : "vmcore"));
821 	}
822 	if (symlink(corename, linkname) == -1) {
823 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
824 		    savedir, linkname);
825 	}
826 
827 	nsaved++;
828 
829 	if (verbose)
830 		printf("dump saved\n");
831 
832 nuke:
833 	if (!keep) {
834 		if (verbose)
835 			printf("clearing dump header\n");
836 		memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof(kdhl.magic));
837 		memcpy(temp, &kdhl, sizeof(kdhl));
838 		if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
839 		    write(fd, temp, sectorsize) != (ssize_t)sectorsize)
840 			syslog(LOG_ERR,
841 			    "error while clearing the dump header: %m");
842 	}
843 	xo_close_container_h(xostdout, "crashdump");
844 	xo_finish_h(xostdout);
845 	free(dumpkey);
846 	free(temp);
847 	close(fd);
848 	return;
849 
850 closeall:
851 	fclose(fp);
852 
853 closefd:
854 	free(dumpkey);
855 	free(temp);
856 	close(fd);
857 }
858 
859 static void
860 usage(void)
861 {
862 	xo_error("%s\n%s\n%s\n",
863 	    "usage: savecore -c [-v] [device ...]",
864 	    "       savecore -C [-v] [device ...]",
865 	    "       savecore [-fkvz] [-m maxdumps] [directory [device ...]]");
866 	exit(1);
867 }
868 
869 int
870 main(int argc, char **argv)
871 {
872 	const char *savedir = ".";
873 	struct fstab *fsp;
874 	int i, ch, error;
875 
876 	checkfor = compress = clear = force = keep = verbose = 0;
877 	nfound = nsaved = nerr = 0;
878 
879 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
880 	signal(SIGINFO, infohandler);
881 
882 	argc = xo_parse_args(argc, argv);
883 	if (argc < 0)
884 		exit(1);
885 
886 	while ((ch = getopt(argc, argv, "Ccfkm:vz")) != -1)
887 		switch(ch) {
888 		case 'C':
889 			checkfor = 1;
890 			break;
891 		case 'c':
892 			clear = 1;
893 			break;
894 		case 'f':
895 			force = 1;
896 			break;
897 		case 'k':
898 			keep = 1;
899 			break;
900 		case 'm':
901 			maxdumps = atoi(optarg);
902 			if (maxdumps <= 0) {
903 				syslog(LOG_ERR, "Invalid maxdump value");
904 				exit(1);
905 			}
906 			break;
907 		case 'v':
908 			verbose++;
909 			break;
910 		case 'z':
911 			compress = 1;
912 			break;
913 		case '?':
914 		default:
915 			usage();
916 		}
917 	if (checkfor && (clear || force || keep))
918 		usage();
919 	if (clear && (compress || keep))
920 		usage();
921 	if (maxdumps > 0 && (checkfor || clear))
922 		usage();
923 	argc -= optind;
924 	argv += optind;
925 	if (argc >= 1 && !checkfor && !clear) {
926 		error = chdir(argv[0]);
927 		if (error) {
928 			syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
929 			exit(1);
930 		}
931 		savedir = argv[0];
932 		argc--;
933 		argv++;
934 	}
935 	if (argc == 0) {
936 		for (;;) {
937 			fsp = getfsent();
938 			if (fsp == NULL)
939 				break;
940 			if (strcmp(fsp->fs_vfstype, "swap") &&
941 			    strcmp(fsp->fs_vfstype, "dump"))
942 				continue;
943 			DoFile(savedir, fsp->fs_spec);
944 		}
945 		endfsent();
946 	} else {
947 		for (i = 0; i < argc; i++)
948 			DoFile(savedir, argv[i]);
949 	}
950 
951 	/* Emit minimal output. */
952 	if (nfound == 0) {
953 		if (checkfor) {
954 			if (verbose)
955 				printf("No dump exists\n");
956 			exit(1);
957 		}
958 		if (verbose)
959 			syslog(LOG_WARNING, "no dumps found");
960 	} else if (nsaved == 0) {
961 		if (nerr != 0) {
962 			if (verbose)
963 				syslog(LOG_WARNING, "unsaved dumps found but not saved");
964 			exit(1);
965 		} else if (verbose)
966 			syslog(LOG_WARNING, "no unsaved dumps found");
967 	}
968 
969 	return (0);
970 }
971 
972 static void
973 infohandler(int sig __unused)
974 {
975 	got_siginfo = 1;
976 }
977