xref: /netbsd-src/sbin/savecore/savecore.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: savecore.c,v 1.74 2008/07/20 01:20:23 lukem 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\
35  The Regents of the University of California.  All rights reserved.");
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 1.74 2008/07/20 01:20:23 lukem 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 	{ .n_name = "_dumpdev" },
76 #define	X_DUMPLO	1
77 	{ .n_name = "_dumplo" },
78 #define	X_TIME_SECOND	2
79 	{ .n_name = "_time_second" },
80 #define X_TIME		3
81 	{ .n_name = "_time" },
82 #define	X_DUMPSIZE	4
83 	{ .n_name = "_dumpsize" },
84 #define	X_VERSION	5
85 	{ .n_name = "_version" },
86 #define	X_DUMPMAG	6
87 	{ .n_name = "_dumpmag" },
88 #define	X_PANICSTR	7
89 	{ .n_name = "_panicstr" },
90 #define	X_PANICSTART	8
91 	{ .n_name = "_panicstart" },
92 #define	X_PANICEND	9
93 	{ .n_name = "_panicend" },
94 #define	X_MSGBUF	10
95 	{ .n_name = "_msgbufp" },
96 #define	X_DUMPCDEV	11
97 	{ .n_name = "_dumpcdev" },
98 	{ .n_name = NULL },
99 };
100 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, X_DUMPCDEV, -1 };
101 int dumpsyms[] = { X_TIME_SECOND, X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR,
102     X_DUMPMAG, -1 };
103 
104 struct nlist dump_nl[] = {	/* Name list for dumped system. */
105 	{ .n_name = "_dumpdev" },	/* Entries MUST be the same as */
106 	{ .n_name = "_dumplo" },	/*	those in current_nl[].  */
107 	{ .n_name = "_time_second" },
108 	{ .n_name = "_time" },
109 	{ .n_name = "_dumpsize" },
110 	{ .n_name = "_version" },
111 	{ .n_name = "_dumpmag" },
112 	{ .n_name = "_panicstr" },
113 	{ .n_name = "_panicstart" },
114 	{ .n_name = "_panicend" },
115 	{ .n_name = "_msgbufp" },
116 	{ .n_name = "_dumpcdev" },
117 	{ .n_name = NULL },
118 };
119 
120 /* Types match kernel declarations. */
121 off_t	dumplo;				/* where dump starts on dumpdev */
122 u_int32_t dumpmag;			/* magic number in dump */
123 int	dumpsize;			/* amount of memory dumped */
124 off_t dumpbytes;			/* in bytes */
125 
126 const char	*kernel;		/* name of used kernel */
127 char	*dirname;			/* directory to save dumps in */
128 char	*ddname;			/* name of dump device */
129 dev_t	dumpdev;			/* dump device */
130 dev_t	dumpcdev = NODEV;		/* dump device (char equivalent) */
131 int	dumpfd;				/* read/write descriptor on dev */
132 kvm_t	*kd_dump;			/* kvm descriptor on dev	*/
133 time_t	now;				/* current date */
134 char	panic_mesg[1024];
135 long	panicstr;
136 char	vers[1024];
137 char	gzmode[3];
138 
139 static int	clear, compress, force, verbose;	/* flags */
140 
141 void	check_kmem(void);
142 int	check_space(void);
143 void	clear_dump(void);
144 int	Create(char *, int);
145 int	dump_exists(void);
146 char	*find_dev(dev_t, int);
147 int	get_crashtime(void);
148 void	kmem_setup(void);
149 void	Lseek(int, off_t, int);
150 int	main(int, char *[]);
151 int	Open(const char *, int rw);
152 char	*rawname(char *s);
153 void	save_core(void);
154 void	usage(void);
155 void	Write(int, void *, int);
156 
157 int
158 main(int argc, char *argv[])
159 {
160 	int ch, level, testonly;
161 	char *ep;
162 
163 	dirname = NULL;
164 	kernel = NULL;
165 	level = 1;		/* default to fastest gzip compression */
166 	testonly = 0;
167 	gzmode[0] = 'w';
168 
169 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
170 
171 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
172 		switch(ch) {
173 		case 'c':
174 			clear = 1;
175 			break;
176 		case 'd':		/* Not documented. */
177 		case 'v':
178 			verbose = 1;
179 			break;
180 		case 'f':
181 			force = 1;
182 			break;
183 		case 'n':
184 			testonly = 1;
185 			break;
186 		case 'N':
187 			kernel = optarg;
188 			break;
189 		case 'z':
190 			compress = 1;
191 			break;
192 		case 'Z':
193 			level = (int)strtol(optarg, &ep, 10);
194 			if (level < 0 || level > 9) {
195 				(void)syslog(LOG_ERR, "invalid compression %s",
196 				    optarg);
197 				usage();
198 			}
199 			break;
200 		case '?':
201 		default:
202 			usage();
203 		}
204 	argc -= optind;
205 	argv += optind;
206 
207 	if (argc != ((clear || testonly) ? 0 : 1))
208 		usage();
209 
210 	gzmode[1] = level + '0';
211 	if (!clear)
212 		dirname = argv[0];
213 
214 	if (kernel == NULL) {
215 		kernel = getbootfile();
216 	}
217 
218 	(void)time(&now);
219 	kmem_setup();
220 
221 	if (clear && !testonly) {
222 		clear_dump();
223 		exit(0);
224 	}
225 
226 	if (!dump_exists() && !force)
227 		exit(1);
228 
229 	if (testonly)
230 		/* If -n was passed and there was a dump, exit at level 0 */
231 		exit(0);
232 
233 	check_kmem();
234 
235 	if (panicstr)
236 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
237 	else
238 		syslog(LOG_ALERT, "reboot");
239 
240 	if ((!get_crashtime() || !check_space()) && !force)
241 		exit(1);
242 
243 	save_core();
244 
245 	clear_dump();
246 	exit(0);
247 }
248 
249 void
250 kmem_setup(void)
251 {
252 	kvm_t *kd_kern;
253 	char errbuf[_POSIX2_LINE_MAX];
254 	int i, hdrsz;
255 
256 	/*
257 	 * Some names we need for the currently running system, others for
258 	 * the system that was running when the dump was made.  The values
259 	 * obtained from the current system are used to look for things in
260 	 * /dev/kmem that cannot be found in the kernel namelist, but are
261 	 * presumed to be the same (since the disk partitions are probably
262 	 * the same!)
263 	 */
264 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
265 	if (kd_kern == NULL) {
266 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
267 		exit(1);
268 	}
269 	if (kvm_nlist(kd_kern, current_nl) == -1)
270 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
271 		    kvm_geterr(kd_kern));
272 
273 	for (i = 0; cursyms[i] != -1; i++) {
274 		if (current_nl[cursyms[i]].n_value != 0)
275 			continue;
276 		switch (cursyms[i]) {
277 		case X_TIME_SECOND:
278 		case X_TIME:
279 		case X_DUMPCDEV:
280 			break;
281 		default:
282 			syslog(LOG_ERR, "%s: %s not in namelist",
283 			    kernel, current_nl[cursyms[i]].n_name);
284 			exit(1);
285 		}
286 	}
287 
288 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
289 		if (verbose)
290 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
291 		exit(1);
292 	}
293 	if (dumpdev == NODEV) {
294 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
295 		exit(1);
296 	}
297 	{
298 	    long l_dumplo;
299 
300 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
301 		    if (verbose)
302 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
303 		    exit(1);
304 	    }
305 	    if (l_dumplo == -1) {
306 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
307 		exit(1);
308 	    }
309 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
310 	}
311 
312 	if (verbose)
313 		(void)printf("dumplo = %lld (%ld * %ld)\n",
314 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
315 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
316 		if (verbose)
317 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
318 		exit(1);
319 	}
320 
321 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
322 	    sizeof(vers));
323 	vers[sizeof(vers) - 1] = '\0';
324 
325 	if (current_nl[X_DUMPCDEV].n_value != 0) {
326 		if (KREAD(kd_kern, current_nl[X_DUMPCDEV].n_value,
327 		    &dumpcdev) != 0) {
328 			if (verbose)
329 				syslog(LOG_WARNING, "kvm_read: %s",
330 			            kvm_geterr(kd_kern));
331 			exit(1);
332 		}
333 		ddname = find_dev(dumpcdev, S_IFCHR);
334 	} else
335 		ddname = find_dev(dumpdev, S_IFBLK);
336 	dumpfd = Open(ddname, O_RDWR);
337 
338 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
339 	if (kd_dump == NULL) {
340 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
341 		exit(1);
342 	}
343 
344 	if (kvm_nlist(kd_dump, dump_nl) == -1)
345 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
346 		    kvm_geterr(kd_dump));
347 
348 	for (i = 0; dumpsyms[i] != -1; i++)
349 		if (dump_nl[dumpsyms[i]].n_value == 0 &&
350 			dumpsyms[i] != X_TIME_SECOND &&
351 			dumpsyms[i] != X_TIME) {
352 			syslog(LOG_ERR, "%s: %s not in namelist",
353 			    kernel, dump_nl[dumpsyms[i]].n_name);
354 			exit(1);
355 		}
356 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
357 
358 	/*
359 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
360 	 * checks, ergo no dump is present...
361 	 */
362 	if (hdrsz == 0) {
363 		syslog(LOG_WARNING, "no core dump");
364 		exit(1);
365 	}
366 	if (hdrsz == -1) {
367 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
368 		    kvm_geterr(kd_dump));
369 		exit(1);
370 	}
371 	dumplo += hdrsz;
372 	kvm_close(kd_kern);
373 }
374 
375 void
376 check_kmem(void)
377 {
378 	char *cp, *bufdata;
379 	struct kern_msgbuf msgbuf, *bufp;
380 	long panicloc, panicstart, panicend;
381 	char core_vers[1024];
382 
383 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
384 	    sizeof(core_vers));
385 	core_vers[sizeof(core_vers) - 1] = '\0';
386 
387 	if (strcmp(vers, core_vers) != 0)
388 		syslog(LOG_WARNING,
389 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
390 		    kernel, vers, core_vers);
391 
392 	panicstart = panicend = 0;
393 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
394 		if (verbose)
395 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
396 		goto nomsguf;
397 	}
398 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
399 		if (verbose)
400 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
401 		goto nomsguf;
402 	}
403 	if (panicstart != 0 && panicend != 0) {
404 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
405 			if (verbose)
406 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
407 			goto nomsguf;
408 		}
409 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
410 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
411 		    offsetof(struct kern_msgbuf, msg_bufc)) {
412 			if (verbose)
413 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
414 			goto nomsguf;
415 		}
416 		if (msgbuf.msg_magic != MSG_MAGIC) {
417 			if (verbose)
418 				syslog(LOG_WARNING, "msgbuf magic incorrect");
419 			goto nomsguf;
420 		}
421 		bufdata = malloc(msgbuf.msg_bufs);
422 		if (bufdata == NULL) {
423 			if (verbose)
424 				syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
425 			goto nomsguf;
426 		}
427 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
428 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
429 			if (verbose)
430 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
431 			free(bufdata);
432 			goto nomsguf;
433 		}
434 		cp = panic_mesg;
435 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
436 			*cp++ = bufdata[panicstart];
437 			panicstart++;
438 			if (panicstart >= msgbuf.msg_bufs)
439 				panicstart = 0;
440 		}
441 		/* Don't end in a new-line */
442 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
443 		if (*cp == '\n')
444 			*cp = '\0';
445 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
446 		free(bufdata);
447 
448 		panicstr = 1;	/* anything not zero */
449 		return;
450 	}
451 nomsguf:
452 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
453 		if (verbose)
454 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
455 		return;
456 	}
457 	if (panicstr) {
458 		cp = panic_mesg;
459 		panicloc = panicstr;
460 		do {
461 			if (KREAD(kd_dump, panicloc, cp) != 0) {
462 				if (verbose)
463 				    syslog(LOG_WARNING, "kvm_read: %s",
464 					kvm_geterr(kd_dump));
465 				break;
466 			}
467 			panicloc++;
468 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
469 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
470 	}
471 }
472 
473 int
474 dump_exists(void)
475 {
476 	u_int32_t newdumpmag;
477 
478 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
479 		if (verbose)
480 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
481 		return (0);
482 	}
483 
484 	/* Read the dump size. */
485 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
486 		if (verbose)
487 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
488 		return (0);
489 	}
490 	dumpbytes = (off_t)dumpsize * getpagesize();
491 
492 	/*
493 	 * Return zero if core dump doesn't seem to be there, and note
494 	 * it for syslog.  This check and return happens after the dump size
495 	 * is read, so dumpsize is whether or not the core is valid (for -f).
496 	 */
497 	if (newdumpmag != dumpmag) {
498 		if (verbose)
499 			syslog(LOG_WARNING,
500 			    "magic number mismatch (0x%x != 0x%x)",
501 			    newdumpmag, dumpmag);
502 		syslog(LOG_WARNING, "no core dump");
503 		return (0);
504 	}
505 	return (1);
506 }
507 
508 void
509 clear_dump(void)
510 {
511 	if (kvm_dump_inval(kd_dump) == -1)
512 		syslog(LOG_ERR, "%s: kvm_dump_inval: %s", ddname,
513 		    kvm_geterr(kd_dump));
514 
515 }
516 
517 char buf[1024 * 1024];
518 
519 void
520 save_core(void)
521 {
522 	FILE *fp;
523 	int bounds, ifd, nr, nw, ofd;
524 	char *rawp, path[MAXPATHLEN];
525 
526 	ofd = -1;
527 	/*
528 	 * Get the current number and update the bounds file.  Do the update
529 	 * now, because may fail later and don't want to overwrite anything.
530 	 */
531 	umask(066);
532 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
533 	if ((fp = fopen(path, "r")) == NULL)
534 		goto err1;
535 	if (fgets(buf, sizeof(buf), fp) == NULL) {
536 		if (ferror(fp))
537 err1:			syslog(LOG_WARNING, "%s: %m", path);
538 		bounds = 0;
539 	} else
540 		bounds = atoi(buf);
541 	if (fp != NULL)
542 		(void)fclose(fp);
543 	if ((fp = fopen(path, "w")) == NULL)
544 		syslog(LOG_ERR, "%s: %m", path);
545 	else {
546 		(void)fprintf(fp, "%d\n", bounds + 1);
547 		(void)fclose(fp);
548 	}
549 
550 	/* Create the core file. */
551 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
552 	    dirname, bounds, compress ? ".gz" : "");
553 	if (compress) {
554 		if ((fp = zopen(path, gzmode)) == NULL) {
555 			syslog(LOG_ERR, "%s: %m", path);
556 			exit(1);
557 		}
558 	} else {
559 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
560 		fp  = fdopen(ofd, "w");
561 		if (fp == NULL) {
562 			syslog(LOG_ERR, "%s: fdopen: %m", path);
563 			exit(1);
564 		}
565 	}
566 
567 	if (dumpcdev == NODEV) {
568 		/* Open the raw device. */
569 		rawp = rawname(ddname);
570 		if ((ifd = open(rawp, O_RDONLY)) == -1) {
571 			syslog(LOG_WARNING, "%s: %m; using block device",
572 			    rawp);
573 			ifd = dumpfd;
574 		}
575 	} else {
576 		rawp = ddname;
577 		ifd = dumpfd;
578 	}
579 
580 	/* Seek to the start of the core. */
581 	Lseek(ifd, dumplo, SEEK_SET);
582 
583 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
584 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
585 		    kvm_geterr(kd_dump));
586 		exit(1);
587 	}
588 
589 	/* Copy the core file. */
590 	syslog(LOG_NOTICE, "writing %score to %s",
591 	    compress ? "compressed " : "", path);
592 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
593 		char nbuf[7];
594 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
595 		(void)printf("%7s\r", nbuf);
596 		(void)fflush(stdout);
597 		nr = read(ifd, buf, MIN(dumpbytes, sizeof(buf)));
598 		if (nr <= 0) {
599 			if (nr == 0)
600 				syslog(LOG_WARNING,
601 				    "WARNING: EOF on dump device");
602 			else
603 				syslog(LOG_ERR, "%s: %m", rawp);
604 			goto err2;
605 		}
606 		nw = fwrite(buf, 1, nr, fp);
607 		if (nw != nr) {
608 			syslog(LOG_ERR, "%s: %s",
609 			    path, strerror(nw == 0 ? EIO : errno));
610 err2:			syslog(LOG_WARNING,
611 			    "WARNING: core may be incomplete");
612 			(void)printf("\n");
613 			exit(1);
614 		}
615 	}
616 	if (dumpcdev == NODEV)
617 		(void)close(ifd);
618 	(void)fclose(fp);
619 
620 	/* Copy the kernel. */
621 	ifd = Open(kernel, O_RDONLY);
622 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
623 	    dirname, bounds, compress ? ".gz" : "");
624 	if (compress) {
625 		if ((fp = zopen(path, gzmode)) == NULL) {
626 			syslog(LOG_ERR, "%s: %m", path);
627 			exit(1);
628 		}
629 	} else
630 		ofd = Create(path, S_IRUSR | S_IWUSR);
631 	syslog(LOG_NOTICE, "writing %skernel to %s",
632 	    compress ? "compressed " : "", path);
633 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
634 		if (compress)
635 			nw = fwrite(buf, 1, nr, fp);
636 		else
637 			nw = write(ofd, buf, nr);
638 		if (nw != nr) {
639 			syslog(LOG_ERR, "%s: %s",
640 			    path, strerror(nw == 0 ? EIO : errno));
641 			syslog(LOG_WARNING,
642 			    "WARNING: kernel may be incomplete");
643 			exit(1);
644 		}
645 	}
646 	if (nr < 0) {
647 		syslog(LOG_ERR, "%s: %m", kernel);
648 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
649 		exit(1);
650 	}
651 	if (compress)
652 		(void)fclose(fp);
653 	else
654 		(void)close(ofd);
655 
656 	/*
657 	 * For development systems where the crash occurs during boot
658 	 * to multiuser.
659 	 */
660 	sync();
661 	sleep(1);
662 	sync();
663 	sleep(1);
664 }
665 
666 char *
667 find_dev(dev_t dev, int type)
668 {
669 	DIR *dfd;
670 	struct dirent *dir;
671 	struct stat sb;
672 	char *dp, device[MAXPATHLEN + 1], *p;
673 	size_t l;
674 
675 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
676 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
677 		exit(1);
678 	}
679 	strlcpy(device, _PATH_DEV, sizeof(device));
680 	p = &device[strlen(device)];
681 	l = sizeof(device) - strlen(device);
682 	while ((dir = readdir(dfd))) {
683 		strlcpy(p, dir->d_name, l);
684 		if (lstat(device, &sb)) {
685 			syslog(LOG_ERR, "%s: %m", device);
686 			continue;
687 		}
688 		if ((sb.st_mode & S_IFMT) != type)
689 			continue;
690 		if (dev == sb.st_rdev) {
691 			closedir(dfd);
692 			if ((dp = strdup(device)) == NULL) {
693 				syslog(LOG_ERR, "%m");
694 				exit(1);
695 			}
696 			return (dp);
697 		}
698 	}
699 	closedir(dfd);
700 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
701 	exit(1);
702 }
703 
704 char *
705 rawname(char *s)
706 {
707 	char *sl;
708 	char name[MAXPATHLEN];
709 
710 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
711 		syslog(LOG_ERR,
712 		    "can't make raw dump device name from %s", s);
713 		return (s);
714 	}
715 	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
716 	    sl + 1);
717 	if ((sl = strdup(name)) == NULL) {
718 		syslog(LOG_ERR, "%m");
719 		exit(1);
720 	}
721 	return (sl);
722 }
723 
724 int
725 get_crashtime(void)
726 {
727 	time_t dumptime;			/* Time the dump was taken. */
728 	struct timeval dtime;
729 
730 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
731 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
732 			if (verbose)
733 				syslog(LOG_WARNING, "kvm_read: %s (and _time_second is not defined also)", kvm_geterr(kd_dump));
734 			return (0);
735 		}
736 		dumptime = dtime.tv_sec;
737 	}
738 	if (dumptime == 0) {
739 		if (verbose)
740 			syslog(LOG_ERR, "dump time is zero");
741 		return (0);
742 	}
743 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
744 #define	LEEWAY	(60 * SECSPERDAY)
745 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
746 		(void)printf("dump time is unreasonable\n");
747 		return (0);
748 	}
749 	return (1);
750 }
751 
752 int
753 check_space(void)
754 {
755 	FILE *fp;
756 	off_t minfree, spacefree, kernelsize, needed;
757 	struct stat st;
758 	struct statvfs fsbuf;
759 	char mbuf[100], path[MAXPATHLEN];
760 
761 	if (stat(kernel, &st) < 0) {
762 		syslog(LOG_ERR, "%s: %m", kernel);
763 		exit(1);
764 	}
765 	kernelsize = st.st_blocks * S_BLKSIZE;
766 	if (statvfs(dirname, &fsbuf) < 0) {
767 		syslog(LOG_ERR, "%s: %m", dirname);
768 		exit(1);
769 	}
770 	spacefree = fsbuf.f_bavail;
771 	spacefree *= fsbuf.f_frsize;
772 	spacefree /= 1024;
773 
774 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
775 	if ((fp = fopen(path, "r")) == NULL)
776 		minfree = 0;
777 	else {
778 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
779 			minfree = 0;
780 		else
781 			minfree = atoi(mbuf);
782 		(void)fclose(fp);
783 	}
784 
785 	needed = (dumpbytes + kernelsize) / 1024;
786  	if (minfree > 0 && spacefree - needed < minfree) {
787 		syslog(LOG_WARNING,
788 		    "no dump, not enough free space in %s", dirname);
789 		return (0);
790 	}
791 	if (spacefree - needed < minfree)
792 		syslog(LOG_WARNING,
793 		    "dump performed, but free space threshold crossed");
794 	return (1);
795 }
796 
797 int
798 Open(const char *name, int rw)
799 {
800 	int fd;
801 
802 	if ((fd = open(name, rw, 0)) < 0) {
803 		syslog(LOG_ERR, "%s: %m", name);
804 		exit(1);
805 	}
806 	return (fd);
807 }
808 
809 void
810 Lseek(int fd, off_t off, int flag)
811 {
812 	off_t ret;
813 
814 	ret = lseek(fd, off, flag);
815 	if (ret == -1) {
816 		syslog(LOG_ERR, "lseek: %m");
817 		exit(1);
818 	}
819 }
820 
821 int
822 Create(char *file, int mode)
823 {
824 	int fd;
825 
826 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
827 	if (fd < 0) {
828 		syslog(LOG_ERR, "%s: %m", file);
829 		exit(1);
830 	}
831 	return (fd);
832 }
833 
834 void
835 Write(int fd, void *bp, int size)
836 {
837 	int n;
838 
839 	if ((n = write(fd, bp, size)) < size) {
840 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
841 		exit(1);
842 	}
843 }
844 
845 void
846 usage(void)
847 {
848 	(void)syslog(LOG_ERR,
849 	    "usage: savecore [-cfnvz] [-N system] [-Z level] directory");
850 	exit(1);
851 }
852