xref: /netbsd-src/sbin/savecore/savecore.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: savecore.c,v 1.67 2006/06/07 20:56:19 kardel Exp $	*/
2 
3 /*-
4  * Copyright (c) 1986, 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41 #else
42 __RCSID("$NetBSD: savecore.c,v 1.67 2006/06/07 20:56:19 kardel Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/mount.h>
48 #include <sys/msgbuf.h>
49 #include <sys/syslog.h>
50 #include <sys/time.h>
51 
52 #include <dirent.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <nlist.h>
56 #include <paths.h>
57 #include <stddef.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <time.h>
62 #include <tzfile.h>
63 #include <unistd.h>
64 #include <util.h>
65 #include <limits.h>
66 #include <kvm.h>
67 
68 extern FILE *zopen(const char *fname, const char *mode);
69 
70 #define	KREAD(kd, addr, p)\
71 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
72 
73 struct nlist current_nl[] = {	/* Namelist for currently running system. */
74 #define	X_DUMPDEV	0
75 	{ "_dumpdev" },
76 #define	X_DUMPLO	1
77 	{ "_dumplo" },
78 #define	X_TIME_SECOND	2
79 #ifdef __HAVE_TIMECOUNTER
80 	{ "_time_second" },
81 #else
82 	{ "_time" },	/* XXX uses same array slot as "X_TIME_SECOND" */
83 #endif
84 #define	X_DUMPSIZE	3
85 	{ "_dumpsize" },
86 #define	X_VERSION	4
87 	{ "_version" },
88 #define	X_DUMPMAG	5
89 	{ "_dumpmag" },
90 #define	X_PANICSTR	6
91 	{ "_panicstr" },
92 #define	X_PANICSTART	7
93 	{ "_panicstart" },
94 #define	X_PANICEND	8
95 	{ "_panicend" },
96 #define	X_MSGBUF	9
97 	{ "_msgbufp" },
98 	{ NULL },
99 };
100 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
101 int dumpsyms[] = { X_TIME_SECOND, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG,
102     -1 };
103 
104 struct nlist dump_nl[] = {	/* Name list for dumped system. */
105 	{ "_dumpdev" },		/* Entries MUST be the same as */
106 	{ "_dumplo" },		/*	those in current_nl[].  */
107 #ifdef __HAVE_TIMECOUNTER
108 	{ "_time_second" },
109 #else
110 	{ "_time" },	/* XXX uses same array slot as "X_TIME_SECOND" */
111 #endif
112 	{ "_dumpsize" },
113 	{ "_version" },
114 	{ "_dumpmag" },
115 	{ "_panicstr" },
116 	{ "_panicstart" },
117 	{ "_panicend" },
118 	{ "_msgbufp" },
119 	{ NULL },
120 };
121 
122 /* Types match kernel declarations. */
123 off_t	dumplo;				/* where dump starts on dumpdev */
124 u_int32_t dumpmag;			/* magic number in dump */
125 int	dumpsize;			/* amount of memory dumped */
126 off_t dumpbytes;			/* in bytes */
127 
128 const char	*kernel;		/* name of used kernel */
129 char	*dirname;			/* directory to save dumps in */
130 char	*ddname;			/* name of dump device */
131 dev_t	dumpdev;			/* dump device */
132 int	dumpfd;				/* read/write descriptor on block dev */
133 kvm_t	*kd_dump;			/* kvm descriptor on block dev	*/
134 time_t	now;				/* current date */
135 char	panic_mesg[1024];
136 long	panicstr;
137 char	vers[1024];
138 char	gzmode[3];
139 
140 static int	clear, compress, force, verbose;	/* flags */
141 
142 void	check_kmem(void);
143 int	check_space(void);
144 void	clear_dump(void);
145 int	Create(char *, int);
146 int	dump_exists(void);
147 char	*find_dev(dev_t, int);
148 int	get_crashtime(void);
149 void	kmem_setup(void);
150 void	Lseek(int, off_t, int);
151 int	main(int, char *[]);
152 int	Open(const char *, int rw);
153 char	*rawname(char *s);
154 void	save_core(void);
155 void	usage(void);
156 void	Write(int, void *, int);
157 
158 int
159 main(int argc, char *argv[])
160 {
161 	int ch, level, testonly;
162 	char *ep;
163 
164 	dirname = NULL;
165 	kernel = NULL;
166 	level = 1;		/* default to fastest gzip compression */
167 	testonly = 0;
168 	gzmode[0] = 'w';
169 
170 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
171 
172 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
173 		switch(ch) {
174 		case 'c':
175 			clear = 1;
176 			break;
177 		case 'd':		/* Not documented. */
178 		case 'v':
179 			verbose = 1;
180 			break;
181 		case 'f':
182 			force = 1;
183 			break;
184 		case 'n':
185 			testonly = 1;
186 			break;
187 		case 'N':
188 			kernel = optarg;
189 			break;
190 		case 'z':
191 			compress = 1;
192 			break;
193 		case 'Z':
194 			level = (int)strtol(optarg, &ep, 10);
195 			if (level < 0 || level > 9) {
196 				(void)syslog(LOG_ERR, "invalid compression %s",
197 				    optarg);
198 				usage();
199 			}
200 			break;
201 		case '?':
202 		default:
203 			usage();
204 		}
205 	argc -= optind;
206 	argv += optind;
207 
208 	if (argc != ((clear || testonly) ? 0 : 1))
209 		usage();
210 
211 	gzmode[1] = level + '0';
212 	if (!clear)
213 		dirname = argv[0];
214 
215 	if (kernel == NULL) {
216 		kernel = getbootfile();
217 	}
218 
219 	(void)time(&now);
220 	kmem_setup();
221 
222 	if (clear && !testonly) {
223 		clear_dump();
224 		exit(0);
225 	}
226 
227 	if (!dump_exists() && !force)
228 		exit(1);
229 
230 	if (testonly)
231 		/* If -n was passed and there was a dump, exit at level 0 */
232 		exit(0);
233 
234 	check_kmem();
235 
236 	if (panicstr)
237 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
238 	else
239 		syslog(LOG_ALERT, "reboot");
240 
241 	if ((!get_crashtime() || !check_space()) && !force)
242 		exit(1);
243 
244 	save_core();
245 
246 	clear_dump();
247 	exit(0);
248 }
249 
250 void
251 kmem_setup(void)
252 {
253 	kvm_t *kd_kern;
254 	char errbuf[_POSIX2_LINE_MAX];
255 	int i, hdrsz;
256 
257 	/*
258 	 * Some names we need for the currently running system, others for
259 	 * the system that was running when the dump was made.  The values
260 	 * obtained from the current system are used to look for things in
261 	 * /dev/kmem that cannot be found in the kernel namelist, but are
262 	 * presumed to be the same (since the disk partitions are probably
263 	 * the same!)
264 	 */
265 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
266 	if (kd_kern == NULL) {
267 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
268 		exit(1);
269 	}
270 	if (kvm_nlist(kd_kern, current_nl) == -1)
271 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
272 		    kvm_geterr(kd_kern));
273 
274 	for (i = 0; cursyms[i] != -1; i++)
275 		if (current_nl[cursyms[i]].n_value == 0) {
276 			syslog(LOG_ERR, "%s: %s not in namelist",
277 			    kernel, current_nl[cursyms[i]].n_name);
278 			exit(1);
279 		}
280 
281 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
282 		if (verbose)
283 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
284 		exit(1);
285 	}
286 	if (dumpdev == NODEV) {
287 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
288 		exit(1);
289 	}
290 	{
291 	    long l_dumplo;
292 
293 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
294 		    if (verbose)
295 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
296 		    exit(1);
297 	    }
298 	    if (l_dumplo == -1) {
299 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
300 		exit(1);
301 	    }
302 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
303 	}
304 
305 	if (verbose)
306 		(void)printf("dumplo = %lld (%ld * %ld)\n",
307 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
308 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
309 		if (verbose)
310 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
311 		exit(1);
312 	}
313 
314 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
315 	    sizeof(vers));
316 	vers[sizeof(vers) - 1] = '\0';
317 
318 	ddname = find_dev(dumpdev, S_IFBLK);
319 	dumpfd = Open(ddname, O_RDWR);
320 
321 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
322 	if (kd_dump == NULL) {
323 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
324 		exit(1);
325 	}
326 
327 	if (kvm_nlist(kd_dump, dump_nl) == -1)
328 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
329 		    kvm_geterr(kd_dump));
330 
331 	for (i = 0; dumpsyms[i] != -1; i++)
332 		if (dump_nl[dumpsyms[i]].n_value == 0) {
333 			syslog(LOG_ERR, "%s: %s not in namelist",
334 			    kernel, dump_nl[dumpsyms[i]].n_name);
335 			exit(1);
336 		}
337 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
338 
339 	/*
340 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
341 	 * checks, ergo no dump is present...
342 	 */
343 	if (hdrsz == 0) {
344 		syslog(LOG_WARNING, "no core dump");
345 		exit(1);
346 	}
347 	if (hdrsz == -1) {
348 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
349 		    kvm_geterr(kd_dump));
350 		exit(1);
351 	}
352 	dumplo += hdrsz;
353 	kvm_close(kd_kern);
354 }
355 
356 void
357 check_kmem(void)
358 {
359 	char *cp, *bufdata;
360 	struct kern_msgbuf msgbuf, *bufp;
361 	long panicloc, panicstart, panicend;
362 	char core_vers[1024];
363 
364 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
365 	    sizeof(core_vers));
366 	core_vers[sizeof(core_vers) - 1] = '\0';
367 
368 	if (strcmp(vers, core_vers) != 0)
369 		syslog(LOG_WARNING,
370 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
371 		    kernel, vers, core_vers);
372 
373 	panicstart = panicend = 0;
374 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
375 		if (verbose)
376 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
377 		goto nomsguf;
378 	}
379 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
380 		if (verbose)
381 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
382 		goto nomsguf;
383 	}
384 	if (panicstart != 0 && panicend != 0) {
385 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
386 			if (verbose)
387 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
388 			goto nomsguf;
389 		}
390 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
391 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
392 		    offsetof(struct kern_msgbuf, msg_bufc)) {
393 			if (verbose)
394 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
395 			goto nomsguf;
396 		}
397 		if (msgbuf.msg_magic != MSG_MAGIC) {
398 			if (verbose)
399 				syslog(LOG_WARNING, "msgbuf magic incorrect");
400 			goto nomsguf;
401 		}
402 		bufdata = malloc(msgbuf.msg_bufs);
403 		if (bufdata == NULL) {
404 			if (verbose)
405 				syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
406 			goto nomsguf;
407 		}
408 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
409 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
410 			if (verbose)
411 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
412 			free(bufdata);
413 			goto nomsguf;
414 		}
415 		cp = panic_mesg;
416 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
417 			*cp++ = bufdata[panicstart];
418 			panicstart++;
419 			if (panicstart >= msgbuf.msg_bufs)
420 				panicstart = 0;
421 		}
422 		/* Don't end in a new-line */
423 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
424 		if (*cp == '\n')
425 			*cp = '\0';
426 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
427 		free(bufdata);
428 
429 		panicstr = 1;	/* anything not zero */
430 		return;
431 	}
432 nomsguf:
433 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
434 		if (verbose)
435 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
436 		return;
437 	}
438 	if (panicstr) {
439 		cp = panic_mesg;
440 		panicloc = panicstr;
441 		do {
442 			if (KREAD(kd_dump, panicloc, cp) != 0) {
443 				if (verbose)
444 				    syslog(LOG_WARNING, "kvm_read: %s",
445 					kvm_geterr(kd_dump));
446 				break;
447 			}
448 			panicloc++;
449 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
450 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
451 	}
452 }
453 
454 int
455 dump_exists(void)
456 {
457 	u_int32_t newdumpmag;
458 
459 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
460 		if (verbose)
461 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
462 		return (0);
463 	}
464 
465 	/* Read the dump size. */
466 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
467 		if (verbose)
468 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
469 		return (0);
470 	}
471 	dumpbytes = (off_t)dumpsize * getpagesize();
472 
473 	/*
474 	 * Return zero if core dump doesn't seem to be there, and note
475 	 * it for syslog.  This check and return happens after the dump size
476 	 * is read, so dumpsize is whether or not the core is valid (for -f).
477 	 */
478 	if (newdumpmag != dumpmag) {
479 		if (verbose)
480 			syslog(LOG_WARNING,
481 			    "magic number mismatch (0x%x != 0x%x)",
482 			    newdumpmag, dumpmag);
483 		syslog(LOG_WARNING, "no core dump");
484 		return (0);
485 	}
486 	return (1);
487 }
488 
489 void
490 clear_dump(void)
491 {
492 	if (kvm_dump_inval(kd_dump) == -1)
493 		syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
494 		    kvm_geterr(kd_dump));
495 
496 }
497 
498 char buf[1024 * 1024];
499 
500 void
501 save_core(void)
502 {
503 	FILE *fp;
504 	int bounds, ifd, nr, nw, ofd;
505 	char *rawp, path[MAXPATHLEN];
506 
507 	ofd = -1;
508 	/*
509 	 * Get the current number and update the bounds file.  Do the update
510 	 * now, because may fail later and don't want to overwrite anything.
511 	 */
512 	umask(066);
513 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
514 	if ((fp = fopen(path, "r")) == NULL)
515 		goto err1;
516 	if (fgets(buf, sizeof(buf), fp) == NULL) {
517 		if (ferror(fp))
518 err1:			syslog(LOG_WARNING, "%s: %m", path);
519 		bounds = 0;
520 	} else
521 		bounds = atoi(buf);
522 	if (fp != NULL)
523 		(void)fclose(fp);
524 	if ((fp = fopen(path, "w")) == NULL)
525 		syslog(LOG_ERR, "%s: %m", path);
526 	else {
527 		(void)fprintf(fp, "%d\n", bounds + 1);
528 		(void)fclose(fp);
529 	}
530 
531 	/* Create the core file. */
532 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
533 	    dirname, bounds, compress ? ".gz" : "");
534 	if (compress) {
535 		if ((fp = zopen(path, gzmode)) == NULL) {
536 			syslog(LOG_ERR, "%s: %m", path);
537 			exit(1);
538 		}
539 	} else {
540 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
541 		fp  = fdopen(ofd, "w");
542 		if (fp == NULL) {
543 			syslog(LOG_ERR, "%s: fdopen: %m", path);
544 			exit(1);
545 		}
546 	}
547 
548 	/* Open the raw device. */
549 	rawp = rawname(ddname);
550 	if ((ifd = open(rawp, O_RDONLY)) == -1) {
551 		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
552 		ifd = dumpfd;
553 	}
554 
555 	/* Seek to the start of the core. */
556 	Lseek(ifd, dumplo, SEEK_SET);
557 
558 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
559 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
560 		    kvm_geterr(kd_dump));
561 		exit(1);
562 	}
563 
564 	/* Copy the core file. */
565 	syslog(LOG_NOTICE, "writing %score to %s",
566 	    compress ? "compressed " : "", path);
567 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
568 		char nbuf[7];
569 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
570 		(void)printf("%7s\r", nbuf);
571 		(void)fflush(stdout);
572 		nr = read(ifd, buf, MIN(dumpbytes, sizeof(buf)));
573 		if (nr <= 0) {
574 			if (nr == 0)
575 				syslog(LOG_WARNING,
576 				    "WARNING: EOF on dump device");
577 			else
578 				syslog(LOG_ERR, "%s: %m", rawp);
579 			goto err2;
580 		}
581 		nw = fwrite(buf, 1, nr, fp);
582 		if (nw != nr) {
583 			syslog(LOG_ERR, "%s: %s",
584 			    path, strerror(nw == 0 ? EIO : errno));
585 err2:			syslog(LOG_WARNING,
586 			    "WARNING: core may be incomplete");
587 			(void)printf("\n");
588 			exit(1);
589 		}
590 	}
591 	(void)close(ifd);
592 	(void)fclose(fp);
593 
594 	/* Copy the kernel. */
595 	ifd = Open(kernel, O_RDONLY);
596 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
597 	    dirname, bounds, compress ? ".gz" : "");
598 	if (compress) {
599 		if ((fp = zopen(path, gzmode)) == NULL) {
600 			syslog(LOG_ERR, "%s: %m", path);
601 			exit(1);
602 		}
603 	} else
604 		ofd = Create(path, S_IRUSR | S_IWUSR);
605 	syslog(LOG_NOTICE, "writing %skernel to %s",
606 	    compress ? "compressed " : "", path);
607 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
608 		if (compress)
609 			nw = fwrite(buf, 1, nr, fp);
610 		else
611 			nw = write(ofd, buf, nr);
612 		if (nw != nr) {
613 			syslog(LOG_ERR, "%s: %s",
614 			    path, strerror(nw == 0 ? EIO : errno));
615 			syslog(LOG_WARNING,
616 			    "WARNING: kernel may be incomplete");
617 			exit(1);
618 		}
619 	}
620 	if (nr < 0) {
621 		syslog(LOG_ERR, "%s: %m", kernel);
622 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
623 		exit(1);
624 	}
625 	if (compress)
626 		(void)fclose(fp);
627 	else
628 		(void)close(ofd);
629 }
630 
631 char *
632 find_dev(dev_t dev, int type)
633 {
634 	DIR *dfd;
635 	struct dirent *dir;
636 	struct stat sb;
637 	char *dp, device[MAXPATHLEN + 1], *p;
638 	size_t l;
639 
640 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
641 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
642 		exit(1);
643 	}
644 	strlcpy(device, _PATH_DEV, sizeof(device));
645 	p = &device[strlen(device)];
646 	l = sizeof(device) - strlen(device);
647 	while ((dir = readdir(dfd))) {
648 		strlcpy(p, dir->d_name, l);
649 		if (lstat(device, &sb)) {
650 			syslog(LOG_ERR, "%s: %m", device);
651 			continue;
652 		}
653 		if ((sb.st_mode & S_IFMT) != type)
654 			continue;
655 		if (dev == sb.st_rdev) {
656 			closedir(dfd);
657 			if ((dp = strdup(device)) == NULL) {
658 				syslog(LOG_ERR, "%m");
659 				exit(1);
660 			}
661 			return (dp);
662 		}
663 	}
664 	closedir(dfd);
665 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
666 	exit(1);
667 }
668 
669 char *
670 rawname(char *s)
671 {
672 	char *sl;
673 	char name[MAXPATHLEN];
674 
675 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
676 		syslog(LOG_ERR,
677 		    "can't make raw dump device name from %s", s);
678 		return (s);
679 	}
680 	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
681 	    sl + 1);
682 	if ((sl = strdup(name)) == NULL) {
683 		syslog(LOG_ERR, "%m");
684 		exit(1);
685 	}
686 	return (sl);
687 }
688 
689 int
690 get_crashtime(void)
691 {
692 	time_t dumptime;			/* Time the dump was taken. */
693 #ifndef __HAVE_TIMECOUNTER
694 	struct timeval dtime;
695 #endif
696 
697 #ifdef __HAVE_TIMECOUNTER
698 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
699 		if (verbose)
700 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
701 		return (0);
702 	}
703 #else
704 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dtime) != 0) {
705 		if (verbose)
706 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
707 		return (0);
708 	}
709 	dumptime = dtime.tv_sec;
710 #endif
711 	if (dumptime == 0) {
712 		if (verbose)
713 			syslog(LOG_ERR, "dump time is zero");
714 		return (0);
715 	}
716 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
717 #define	LEEWAY	(60 * SECSPERDAY)
718 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
719 		(void)printf("dump time is unreasonable\n");
720 		return (0);
721 	}
722 	return (1);
723 }
724 
725 int
726 check_space(void)
727 {
728 	FILE *fp;
729 	off_t minfree, spacefree, kernelsize, needed;
730 	struct stat st;
731 	struct statvfs fsbuf;
732 	char mbuf[100], path[MAXPATHLEN];
733 
734 #ifdef __GNUC__
735 	(void) &minfree;
736 #endif
737 
738 	if (stat(kernel, &st) < 0) {
739 		syslog(LOG_ERR, "%s: %m", kernel);
740 		exit(1);
741 	}
742 	kernelsize = st.st_blocks * S_BLKSIZE;
743 	if (statvfs(dirname, &fsbuf) < 0) {
744 		syslog(LOG_ERR, "%s: %m", dirname);
745 		exit(1);
746 	}
747 	spacefree = fsbuf.f_bavail;
748 	spacefree *= fsbuf.f_frsize;
749 	spacefree /= 1024;
750 
751 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
752 	if ((fp = fopen(path, "r")) == NULL)
753 		minfree = 0;
754 	else {
755 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
756 			minfree = 0;
757 		else
758 			minfree = atoi(mbuf);
759 		(void)fclose(fp);
760 	}
761 
762 	needed = (dumpbytes + kernelsize) / 1024;
763  	if (minfree > 0 && spacefree - needed < minfree) {
764 		syslog(LOG_WARNING,
765 		    "no dump, not enough free space in %s", dirname);
766 		return (0);
767 	}
768 	if (spacefree - needed < minfree)
769 		syslog(LOG_WARNING,
770 		    "dump performed, but free space threshold crossed");
771 	return (1);
772 }
773 
774 int
775 Open(const char *name, int rw)
776 {
777 	int fd;
778 
779 	if ((fd = open(name, rw, 0)) < 0) {
780 		syslog(LOG_ERR, "%s: %m", name);
781 		exit(1);
782 	}
783 	return (fd);
784 }
785 
786 void
787 Lseek(int fd, off_t off, int flag)
788 {
789 	off_t ret;
790 
791 	ret = lseek(fd, off, flag);
792 	if (ret == -1) {
793 		syslog(LOG_ERR, "lseek: %m");
794 		exit(1);
795 	}
796 }
797 
798 int
799 Create(char *file, int mode)
800 {
801 	int fd;
802 
803 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
804 	if (fd < 0) {
805 		syslog(LOG_ERR, "%s: %m", file);
806 		exit(1);
807 	}
808 	return (fd);
809 }
810 
811 void
812 Write(int fd, void *bp, int size)
813 {
814 	int n;
815 
816 	if ((n = write(fd, bp, size)) < size) {
817 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
818 		exit(1);
819 	}
820 }
821 
822 void
823 usage(void)
824 {
825 	(void)syslog(LOG_ERR,
826 	    "usage: savecore [-cfnvz] [-N system] [-Z level] directory");
827 	exit(1);
828 }
829