xref: /freebsd/sbin/savecore/savecore.c (revision 63d1fd5970ec814904aa0f4580b10a0d302d08b2)
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 <stdbool.h>
78 #include <stdio.h>
79 #include <stdlib.h>
80 #include <string.h>
81 #include <syslog.h>
82 #include <time.h>
83 #include <unistd.h>
84 #include <libxo/xo.h>
85 
86 /* The size of the buffer used for I/O. */
87 #define	BUFFERSIZE	(1024*1024)
88 
89 #define	STATUS_BAD	0
90 #define	STATUS_GOOD	1
91 #define	STATUS_UNKNOWN	2
92 
93 static int checkfor, compress, clear, force, keep, verbose;	/* flags */
94 static int nfound, nsaved, nerr;			/* statistics */
95 static int maxdumps;
96 
97 extern FILE *zopen(const char *, const char *);
98 
99 static sig_atomic_t got_siginfo;
100 static void infohandler(int);
101 
102 static void
103 printheader(xo_handle_t *xo, const struct kerneldumpheader *h, const char *device,
104     int bounds, const int status)
105 {
106 	uint64_t dumplen;
107 	time_t t;
108 	const char *stat_str;
109 
110 	xo_flush_h(xo);
111 	xo_emit_h(xo, "{Lwc:Dump header from device}{:dump_device/%s}\n", device);
112 	xo_emit_h(xo, "{P:  }{Lwc:Architecture}{:architecture/%s}\n", h->architecture);
113 	xo_emit_h(xo, "{P:  }{Lwc:Architecture Version}{:architecture_version/%u}\n", dtoh32(h->architectureversion));
114 	dumplen = dtoh64(h->dumplength);
115 	xo_emit_h(xo, "{P:  }{Lwc:Dump Length}{:dump_length_bytes/%lld}\n", (long long)dumplen);
116 	xo_emit_h(xo, "{P:  }{Lwc:Blocksize}{:blocksize/%d}\n", dtoh32(h->blocksize));
117 	t = dtoh64(h->dumptime);
118 	xo_emit_h(xo, "{P:  }{Lwc:Dumptime}{:dumptime/%s}", ctime(&t));
119 	xo_emit_h(xo, "{P:  }{Lwc:Hostname}{:hostname/%s}\n", h->hostname);
120 	xo_emit_h(xo, "{P:  }{Lwc:Magic}{:magic/%s}\n", h->magic);
121 	xo_emit_h(xo, "{P:  }{Lwc:Version String}{:version_string/%s}", h->versionstring);
122 	xo_emit_h(xo, "{P:  }{Lwc:Panic String}{:panic_string/%s}\n", h->panicstring);
123 	xo_emit_h(xo, "{P:  }{Lwc:Dump Parity}{:dump_parity/%u}\n", h->parity);
124 	xo_emit_h(xo, "{P:  }{Lwc:Bounds}{:bounds/%d}\n", bounds);
125 
126 	switch(status) {
127 	case STATUS_BAD:
128 		stat_str = "bad";
129 		break;
130 	case STATUS_GOOD:
131 		stat_str = "good";
132 		break;
133 	default:
134 		stat_str = "unknown";
135 	}
136 	xo_emit_h(xo, "{P:  }{Lwc:Dump Status}{:dump_status/%s}\n", stat_str);
137 	xo_flush_h(xo);
138 }
139 
140 static int
141 getbounds(void) {
142 	FILE *fp;
143 	char buf[6];
144 	int ret;
145 
146 	ret = 0;
147 
148 	if ((fp = fopen("bounds", "r")) == NULL) {
149 		if (verbose)
150 			printf("unable to open bounds file, using 0\n");
151 		return (ret);
152 	}
153 
154 	if (fgets(buf, sizeof buf, fp) == NULL) {
155 		if (feof(fp))
156 			syslog(LOG_WARNING, "bounds file is empty, using 0");
157 		else
158 			syslog(LOG_WARNING, "bounds file: %s", strerror(errno));
159 		fclose(fp);
160 		return (ret);
161 	}
162 
163 	errno = 0;
164 	ret = (int)strtol(buf, NULL, 10);
165 	if (ret == 0 && (errno == EINVAL || errno == ERANGE))
166 		syslog(LOG_WARNING, "invalid value found in bounds, using 0");
167 	fclose(fp);
168 	return (ret);
169 }
170 
171 static void
172 writebounds(int bounds) {
173 	FILE *fp;
174 
175 	if ((fp = fopen("bounds", "w")) == NULL) {
176 		syslog(LOG_WARNING, "unable to write to bounds file: %m");
177 		return;
178 	}
179 
180 	if (verbose)
181 		printf("bounds number: %d\n", bounds);
182 
183 	fprintf(fp, "%d\n", bounds);
184 	fclose(fp);
185 }
186 
187 static bool
188 writekey(const char *keyname, uint8_t *dumpkey, uint32_t dumpkeysize)
189 {
190 	int fd;
191 
192 	fd = open(keyname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
193 	if (fd == -1) {
194 		syslog(LOG_ERR, "Unable to open %s to write the key: %m.",
195 		    keyname);
196 		return (false);
197 	}
198 
199 	if (write(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
200 		syslog(LOG_ERR, "Unable to write the key to %s: %m.", keyname);
201 		close(fd);
202 		return (false);
203 	}
204 
205 	close(fd);
206 	return (true);
207 }
208 
209 static off_t
210 file_size(const char *path)
211 {
212 	struct stat sb;
213 
214 	/* Ignore all errors, those file may not exists. */
215 	if (stat(path, &sb) == -1)
216 		return (0);
217 	return (sb.st_size);
218 }
219 
220 static off_t
221 saved_dump_size(int bounds)
222 {
223 	static char path[PATH_MAX];
224 	off_t dumpsize;
225 
226 	dumpsize = 0;
227 
228 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
229 	dumpsize += file_size(path);
230 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
231 	dumpsize += file_size(path);
232 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
233 	dumpsize += file_size(path);
234 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
235 	dumpsize += file_size(path);
236 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
237 	dumpsize += file_size(path);
238 
239 	return (dumpsize);
240 }
241 
242 static void
243 saved_dump_remove(int bounds)
244 {
245 	static char path[PATH_MAX];
246 
247 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
248 	(void)unlink(path);
249 	(void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
250 	(void)unlink(path);
251 	(void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
252 	(void)unlink(path);
253 	(void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
254 	(void)unlink(path);
255 	(void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
256 	(void)unlink(path);
257 }
258 
259 static void
260 symlinks_remove(void)
261 {
262 
263 	(void)unlink("info.last");
264 	(void)unlink("key.last");
265 	(void)unlink("vmcore.last");
266 	(void)unlink("vmcore.last.gz");
267 	(void)unlink("vmcore_encrypted.last");
268 	(void)unlink("vmcore_encrypted.last.gz");
269 	(void)unlink("textdump.tar.last");
270 	(void)unlink("textdump.tar.last.gz");
271 }
272 
273 /*
274  * Check that sufficient space is available on the disk that holds the
275  * save directory.
276  */
277 static int
278 check_space(const char *savedir, off_t dumpsize, int bounds)
279 {
280 	FILE *fp;
281 	off_t minfree, spacefree, totfree, needed;
282 	struct statfs fsbuf;
283 	char buf[100];
284 
285 	if (statfs(".", &fsbuf) < 0) {
286 		syslog(LOG_ERR, "%s: %m", savedir);
287 		exit(1);
288 	}
289 	spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
290 	totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
291 
292 	if ((fp = fopen("minfree", "r")) == NULL)
293 		minfree = 0;
294 	else {
295 		if (fgets(buf, sizeof(buf), fp) == NULL)
296 			minfree = 0;
297 		else
298 			minfree = atoi(buf);
299 		(void)fclose(fp);
300 	}
301 
302 	needed = dumpsize / 1024 + 2;	/* 2 for info file */
303 	needed -= saved_dump_size(bounds);
304 	if ((minfree > 0 ? spacefree : totfree) - needed < minfree) {
305 		syslog(LOG_WARNING,
306 	"no dump, not enough free space on device (%lld available, need %lld)",
307 		    (long long)(minfree > 0 ? spacefree : totfree),
308 		    (long long)needed);
309 		return (0);
310 	}
311 	if (spacefree - needed < 0)
312 		syslog(LOG_WARNING,
313 		    "dump performed, but free space threshold crossed");
314 	return (1);
315 }
316 
317 #define BLOCKSIZE (1<<12)
318 #define BLOCKMASK (~(BLOCKSIZE-1))
319 
320 static int
321 DoRegularFile(int fd, bool isencrypted, off_t dumpsize, char *buf,
322     const char *device, const char *filename, FILE *fp)
323 {
324 	int he, hs, nr, nw, wl;
325 	off_t dmpcnt, origsize;
326 
327 	dmpcnt = 0;
328 	origsize = dumpsize;
329 	he = 0;
330 	while (dumpsize > 0) {
331 		wl = BUFFERSIZE;
332 		if (wl > dumpsize)
333 			wl = dumpsize;
334 		nr = read(fd, buf, wl);
335 		if (nr != wl) {
336 			if (nr == 0)
337 				syslog(LOG_WARNING,
338 				    "WARNING: EOF on dump device");
339 			else
340 				syslog(LOG_ERR, "read error on %s: %m", device);
341 			nerr++;
342 			return (-1);
343 		}
344 		if (compress || isencrypted) {
345 			nw = fwrite(buf, 1, wl, fp);
346 		} else {
347 			for (nw = 0; nw < nr; nw = he) {
348 				/* find a contiguous block of zeroes */
349 				for (hs = nw; hs < nr; hs += BLOCKSIZE) {
350 					for (he = hs; he < nr && buf[he] == 0;
351 					    ++he)
352 						/* nothing */ ;
353 					/* is the hole long enough to matter? */
354 					if (he >= hs + BLOCKSIZE)
355 						break;
356 				}
357 
358 				/* back down to a block boundary */
359 				he &= BLOCKMASK;
360 
361 				/*
362 				 * 1) Don't go beyond the end of the buffer.
363 				 * 2) If the end of the buffer is less than
364 				 *    BLOCKSIZE bytes away, we're at the end
365 				 *    of the file, so just grab what's left.
366 				 */
367 				if (hs + BLOCKSIZE > nr)
368 					hs = he = nr;
369 
370 				/*
371 				 * At this point, we have a partial ordering:
372 				 *     nw <= hs <= he <= nr
373 				 * If hs > nw, buf[nw..hs] contains non-zero data.
374 				 * If he > hs, buf[hs..he] is all zeroes.
375 				 */
376 				if (hs > nw)
377 					if (fwrite(buf + nw, hs - nw, 1, fp)
378 					    != 1)
379 					break;
380 				if (he > hs)
381 					if (fseeko(fp, he - hs, SEEK_CUR) == -1)
382 						break;
383 			}
384 		}
385 		if (nw != wl) {
386 			syslog(LOG_ERR,
387 			    "write error on %s file: %m", filename);
388 			syslog(LOG_WARNING,
389 			    "WARNING: vmcore may be incomplete");
390 			nerr++;
391 			return (-1);
392 		}
393 		if (verbose) {
394 			dmpcnt += wl;
395 			printf("%llu\r", (unsigned long long)dmpcnt);
396 			fflush(stdout);
397 		}
398 		dumpsize -= wl;
399 		if (got_siginfo) {
400 			printf("%s %.1lf%%\n", filename, (100.0 - (100.0 *
401 			    (double)dumpsize / (double)origsize)));
402 			got_siginfo = 0;
403 		}
404 	}
405 	return (0);
406 }
407 
408 /*
409  * Specialized version of dump-reading logic for use with textdumps, which
410  * are written backwards from the end of the partition, and must be reversed
411  * before being written to the file.  Textdumps are small, so do a bit less
412  * work to optimize/sparsify.
413  */
414 static int
415 DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
416     const char *device, const char *filename, FILE *fp)
417 {
418 	int nr, nw, wl;
419 	off_t dmpcnt, totsize;
420 
421 	totsize = dumpsize;
422 	dmpcnt = 0;
423 	wl = 512;
424 	if ((dumpsize % wl) != 0) {
425 		syslog(LOG_ERR, "textdump uneven multiple of 512 on %s",
426 		    device);
427 		nerr++;
428 		return (-1);
429 	}
430 	while (dumpsize > 0) {
431 		nr = pread(fd, buf, wl, lasthd - (totsize - dumpsize) - wl);
432 		if (nr != wl) {
433 			if (nr == 0)
434 				syslog(LOG_WARNING,
435 				    "WARNING: EOF on dump device");
436 			else
437 				syslog(LOG_ERR, "read error on %s: %m", device);
438 			nerr++;
439 			return (-1);
440 		}
441 		nw = fwrite(buf, 1, wl, fp);
442 		if (nw != wl) {
443 			syslog(LOG_ERR,
444 			    "write error on %s file: %m", filename);
445 			syslog(LOG_WARNING,
446 			    "WARNING: textdump may be incomplete");
447 			nerr++;
448 			return (-1);
449 		}
450 		if (verbose) {
451 			dmpcnt += wl;
452 			printf("%llu\r", (unsigned long long)dmpcnt);
453 			fflush(stdout);
454 		}
455 		dumpsize -= wl;
456 	}
457 	return (0);
458 }
459 
460 static void
461 DoFile(const char *savedir, const char *device)
462 {
463 	xo_handle_t *xostdout, *xoinfo;
464 	static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
465 	static char keyname[PATH_MAX];
466 	static char *buf = NULL;
467 	char *temp = NULL;
468 	struct kerneldumpheader kdhf, kdhl;
469 	uint8_t *dumpkey;
470 	off_t mediasize, dumpsize, firsthd, lasthd;
471 	FILE *info, *fp;
472 	mode_t oumask;
473 	int fd, fdinfo, error;
474 	int bounds, status;
475 	u_int sectorsize, xostyle;
476 	int istextdump;
477 	uint32_t dumpkeysize;
478 	bool isencrypted, ret;
479 
480 	bounds = getbounds();
481 	mediasize = 0;
482 	status = STATUS_UNKNOWN;
483 
484 	xostdout = xo_create_to_file(stdout, XO_STYLE_TEXT, 0);
485 	if (xostdout == NULL) {
486 		syslog(LOG_ERR, "%s: %m", infoname);
487 		return;
488 	}
489 
490 	if (maxdumps > 0 && bounds == maxdumps)
491 		bounds = 0;
492 
493 	if (buf == NULL) {
494 		buf = malloc(BUFFERSIZE);
495 		if (buf == NULL) {
496 			syslog(LOG_ERR, "%m");
497 			return;
498 		}
499 	}
500 
501 	if (verbose)
502 		printf("checking for kernel dump on device %s\n", device);
503 
504 	fd = open(device, (checkfor || keep) ? O_RDONLY : O_RDWR);
505 	if (fd < 0) {
506 		syslog(LOG_ERR, "%s: %m", device);
507 		return;
508 	}
509 
510 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
511 	if (!error)
512 		error = ioctl(fd, DIOCGSECTORSIZE, &sectorsize);
513 	if (error) {
514 		syslog(LOG_ERR,
515 		    "couldn't find media and/or sector size of %s: %m", device);
516 		goto closefd;
517 	}
518 
519 	if (verbose) {
520 		printf("mediasize = %lld\n", (long long)mediasize);
521 		printf("sectorsize = %u\n", sectorsize);
522 	}
523 
524 	if (sectorsize < sizeof(kdhl)) {
525 		syslog(LOG_ERR,
526 		    "Sector size is less the kernel dump header %zu",
527 		    sizeof(kdhl));
528 		goto closefd;
529 	}
530 
531 	lasthd = mediasize - sectorsize;
532 	temp = malloc(sectorsize);
533 	if (temp == NULL) {
534 		syslog(LOG_ERR, "%m");
535 		goto closefd;
536 	}
537 	if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
538 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
539 		syslog(LOG_ERR,
540 		    "error reading last dump header at offset %lld in %s: %m",
541 		    (long long)lasthd, device);
542 		goto closefd;
543 	}
544 	memcpy(&kdhl, temp, sizeof(kdhl));
545 	istextdump = 0;
546 	if (strncmp(kdhl.magic, TEXTDUMPMAGIC, sizeof kdhl) == 0) {
547 		if (verbose)
548 			printf("textdump magic on last dump header on %s\n",
549 			    device);
550 		istextdump = 1;
551 		if (dtoh32(kdhl.version) != KERNELDUMP_TEXT_VERSION) {
552 			syslog(LOG_ERR,
553 			    "unknown version (%d) in last dump header on %s",
554 			    dtoh32(kdhl.version), device);
555 
556 			status = STATUS_BAD;
557 			if (force == 0)
558 				goto closefd;
559 		}
560 	} else if (memcmp(kdhl.magic, KERNELDUMPMAGIC, sizeof kdhl.magic) ==
561 	    0) {
562 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
563 			syslog(LOG_ERR,
564 			    "unknown version (%d) in last dump header on %s",
565 			    dtoh32(kdhl.version), device);
566 
567 			status = STATUS_BAD;
568 			if (force == 0)
569 				goto closefd;
570 		}
571 	} else {
572 		if (verbose)
573 			printf("magic mismatch on last dump header on %s\n",
574 			    device);
575 
576 		status = STATUS_BAD;
577 		if (force == 0)
578 			goto closefd;
579 
580 		if (memcmp(kdhl.magic, KERNELDUMPMAGIC_CLEARED,
581 			    sizeof kdhl.magic) == 0) {
582 			if (verbose)
583 				printf("forcing magic on %s\n", device);
584 			memcpy(kdhl.magic, KERNELDUMPMAGIC,
585 			    sizeof kdhl.magic);
586 		} else {
587 			syslog(LOG_ERR, "unable to force dump - bad magic");
588 			goto closefd;
589 		}
590 		if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
591 			syslog(LOG_ERR,
592 			    "unknown version (%d) in last dump header on %s",
593 			    dtoh32(kdhl.version), device);
594 
595 			status = STATUS_BAD;
596 			if (force == 0)
597 				goto closefd;
598 		}
599 	}
600 
601 	nfound++;
602 	if (clear)
603 		goto nuke;
604 
605 	if (kerneldump_parity(&kdhl)) {
606 		syslog(LOG_ERR,
607 		    "parity error on last dump header on %s", device);
608 		nerr++;
609 		status = STATUS_BAD;
610 		if (force == 0)
611 			goto closefd;
612 	}
613 	dumpsize = dtoh64(kdhl.dumplength);
614 	dumpkeysize = dtoh32(kdhl.dumpkeysize);
615 	firsthd = lasthd - dumpsize - sectorsize - dumpkeysize;
616 	if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
617 	    read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
618 		syslog(LOG_ERR,
619 		    "error reading first dump header at offset %lld in %s: %m",
620 		    (long long)firsthd, device);
621 		nerr++;
622 		goto closefd;
623 	}
624 	memcpy(&kdhf, temp, sizeof(kdhf));
625 
626 	if (verbose >= 2) {
627 		printf("First dump headers:\n");
628 		printheader(xostdout, &kdhf, device, bounds, -1);
629 
630 		printf("\nLast dump headers:\n");
631 		printheader(xostdout, &kdhl, device, bounds, -1);
632 		printf("\n");
633 	}
634 
635 	if (memcmp(&kdhl, &kdhf, sizeof(kdhl))) {
636 		syslog(LOG_ERR,
637 		    "first and last dump headers disagree on %s", device);
638 		nerr++;
639 		status = STATUS_BAD;
640 		if (force == 0)
641 			goto closefd;
642 	} else {
643 		status = STATUS_GOOD;
644 	}
645 
646 	if (checkfor) {
647 		printf("A dump exists on %s\n", device);
648 		close(fd);
649 		exit(0);
650 	}
651 
652 	if (kdhl.panicstring[0] != '\0')
653 		syslog(LOG_ALERT, "reboot after panic: %*s",
654 		    (int)sizeof(kdhl.panicstring), kdhl.panicstring);
655 	else
656 		syslog(LOG_ALERT, "reboot");
657 
658 	if (verbose)
659 		printf("Checking for available free space\n");
660 
661 	if (!check_space(savedir, dumpsize, bounds)) {
662 		nerr++;
663 		goto closefd;
664 	}
665 
666 	writebounds(bounds + 1);
667 
668 	saved_dump_remove(bounds);
669 
670 	snprintf(infoname, sizeof(infoname), "info.%d", bounds);
671 
672 	/*
673 	 * Create or overwrite any existing dump header files.
674 	 */
675 	fdinfo = open(infoname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
676 	if (fdinfo < 0) {
677 		syslog(LOG_ERR, "%s: %m", infoname);
678 		nerr++;
679 		goto closefd;
680 	}
681 
682 	oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
683 	isencrypted = (dumpkeysize > 0);
684 	if (compress) {
685 		snprintf(corename, sizeof(corename), "%s.%d.gz",
686 		    istextdump ? "textdump.tar" :
687 		    (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
688 		fp = zopen(corename, "w");
689 	} else {
690 		snprintf(corename, sizeof(corename), "%s.%d",
691 		    istextdump ? "textdump.tar" :
692 		    (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
693 		fp = fopen(corename, "w");
694 	}
695 	if (fp == NULL) {
696 		syslog(LOG_ERR, "%s: %m", corename);
697 		close(fdinfo);
698 		nerr++;
699 		goto closefd;
700 	}
701 	(void)umask(oumask);
702 
703 	info = fdopen(fdinfo, "w");
704 
705 	if (info == NULL) {
706 		syslog(LOG_ERR, "fdopen failed: %m");
707 		nerr++;
708 		goto closeall;
709 	}
710 
711 	xostyle = xo_get_style(NULL);
712 	xoinfo = xo_create_to_file(info, xostyle, 0);
713 	if (xoinfo == NULL) {
714 		syslog(LOG_ERR, "%s: %m", infoname);
715 		nerr++;
716 		goto closeall;
717 	}
718 	xo_open_container_h(xoinfo, "crashdump");
719 
720 	if (verbose)
721 		printheader(xostdout, &kdhl, device, bounds, status);
722 
723 	printheader(xoinfo, &kdhl, device, bounds, status);
724 	xo_close_container_h(xoinfo, "crashdump");
725 	xo_flush_h(xoinfo);
726 	xo_finish_h(xoinfo);
727 	fclose(info);
728 
729 	if (isencrypted) {
730 		dumpkey = calloc(1, dumpkeysize);
731 		if (dumpkey == NULL) {
732 			syslog(LOG_ERR, "Unable to allocate kernel dump key.");
733 			nerr++;
734 			goto closeall;
735 		}
736 
737 		if (read(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
738 			syslog(LOG_ERR, "Unable to read kernel dump key: %m.");
739 			nerr++;
740 			goto closeall;
741 		}
742 
743 		snprintf(keyname, sizeof(keyname), "key.%d", bounds);
744 		ret = writekey(keyname, dumpkey, dumpkeysize);
745 		explicit_bzero(dumpkey, dumpkeysize);
746 		if (!ret) {
747 			nerr++;
748 			goto closeall;
749 		}
750 	}
751 
752 	syslog(LOG_NOTICE, "writing %s%score to %s/%s",
753 	    isencrypted ? "encrypted " : "", compress ? "compressed " : "",
754 	    savedir, corename);
755 
756 	if (istextdump) {
757 		if (DoTextdumpFile(fd, dumpsize, lasthd, buf, device,
758 		    corename, fp) < 0)
759 			goto closeall;
760 	} else {
761 		if (DoRegularFile(fd, isencrypted, dumpsize, buf, device,
762 		    corename, fp) < 0) {
763 			goto closeall;
764 		}
765 	}
766 	if (verbose)
767 		printf("\n");
768 
769 	if (fclose(fp) < 0) {
770 		syslog(LOG_ERR, "error on %s: %m", corename);
771 		nerr++;
772 		goto closefd;
773 	}
774 
775 	symlinks_remove();
776 	if (symlink(infoname, "info.last") == -1) {
777 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
778 		    savedir, "info.last");
779 	}
780 	if (isencrypted) {
781 		if (symlink(keyname, "key.last") == -1) {
782 			syslog(LOG_WARNING,
783 			    "unable to create symlink %s/%s: %m", savedir,
784 			    "key.last");
785 		}
786 	}
787 	if (compress) {
788 		snprintf(linkname, sizeof(linkname), "%s.last.gz",
789 		    istextdump ? "textdump.tar" :
790 		    (isencrypted ? "vmcore_encrypted" : "vmcore"));
791 	} else {
792 		snprintf(linkname, sizeof(linkname), "%s.last",
793 		    istextdump ? "textdump.tar" :
794 		    (isencrypted ? "vmcore_encrypted" : "vmcore"));
795 	}
796 	if (symlink(corename, linkname) == -1) {
797 		syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
798 		    savedir, linkname);
799 	}
800 
801 	nsaved++;
802 
803 	if (verbose)
804 		printf("dump saved\n");
805 
806 nuke:
807 	if (!keep) {
808 		if (verbose)
809 			printf("clearing dump header\n");
810 		memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof(kdhl.magic));
811 		memcpy(temp, &kdhl, sizeof(kdhl));
812 		if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
813 		    write(fd, temp, sectorsize) != (ssize_t)sectorsize)
814 			syslog(LOG_ERR,
815 			    "error while clearing the dump header: %m");
816 	}
817 	xo_close_container_h(xostdout, "crashdump");
818 	xo_finish_h(xostdout);
819 	free(temp);
820 	close(fd);
821 	return;
822 
823 closeall:
824 	fclose(fp);
825 
826 closefd:
827 	free(temp);
828 	close(fd);
829 }
830 
831 static void
832 usage(void)
833 {
834 	xo_error("%s\n%s\n%s\n",
835 	    "usage: savecore -c [-v] [device ...]",
836 	    "       savecore -C [-v] [device ...]",
837 	    "       savecore [-fkvz] [-m maxdumps] [directory [device ...]]");
838 	exit(1);
839 }
840 
841 int
842 main(int argc, char **argv)
843 {
844 	const char *savedir = ".";
845 	struct fstab *fsp;
846 	int i, ch, error;
847 
848 	checkfor = compress = clear = force = keep = verbose = 0;
849 	nfound = nsaved = nerr = 0;
850 
851 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
852 	signal(SIGINFO, infohandler);
853 
854 	argc = xo_parse_args(argc, argv);
855 	if (argc < 0)
856 		exit(1);
857 
858 	while ((ch = getopt(argc, argv, "Ccfkm:vz")) != -1)
859 		switch(ch) {
860 		case 'C':
861 			checkfor = 1;
862 			break;
863 		case 'c':
864 			clear = 1;
865 			break;
866 		case 'f':
867 			force = 1;
868 			break;
869 		case 'k':
870 			keep = 1;
871 			break;
872 		case 'm':
873 			maxdumps = atoi(optarg);
874 			if (maxdumps <= 0) {
875 				syslog(LOG_ERR, "Invalid maxdump value");
876 				exit(1);
877 			}
878 			break;
879 		case 'v':
880 			verbose++;
881 			break;
882 		case 'z':
883 			compress = 1;
884 			break;
885 		case '?':
886 		default:
887 			usage();
888 		}
889 	if (checkfor && (clear || force || keep))
890 		usage();
891 	if (clear && (compress || keep))
892 		usage();
893 	if (maxdumps > 0 && (checkfor || clear))
894 		usage();
895 	argc -= optind;
896 	argv += optind;
897 	if (argc >= 1 && !checkfor && !clear) {
898 		error = chdir(argv[0]);
899 		if (error) {
900 			syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
901 			exit(1);
902 		}
903 		savedir = argv[0];
904 		argc--;
905 		argv++;
906 	}
907 	if (argc == 0) {
908 		for (;;) {
909 			fsp = getfsent();
910 			if (fsp == NULL)
911 				break;
912 			if (strcmp(fsp->fs_vfstype, "swap") &&
913 			    strcmp(fsp->fs_vfstype, "dump"))
914 				continue;
915 			DoFile(savedir, fsp->fs_spec);
916 		}
917 		endfsent();
918 	} else {
919 		for (i = 0; i < argc; i++)
920 			DoFile(savedir, argv[i]);
921 	}
922 
923 	/* Emit minimal output. */
924 	if (nfound == 0) {
925 		if (checkfor) {
926 			if (verbose)
927 				printf("No dump exists\n");
928 			exit(1);
929 		}
930 		if (verbose)
931 			syslog(LOG_WARNING, "no dumps found");
932 	} else if (nsaved == 0) {
933 		if (nerr != 0) {
934 			if (verbose)
935 				syslog(LOG_WARNING, "unsaved dumps found but not saved");
936 			exit(1);
937 		} else if (verbose)
938 			syslog(LOG_WARNING, "no unsaved dumps found");
939 	}
940 
941 	return (0);
942 }
943 
944 static void
945 infohandler(int sig __unused)
946 {
947 	got_siginfo = 1;
948 }
949