savecore.c revision 1.64
1/*	$NetBSD: savecore.c,v 1.64 2004/07/14 07:26:12 tls 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
40static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41#else
42__RCSID("$NetBSD: savecore.c,v 1.64 2004/07/14 07:26:12 tls 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
68extern 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
73struct 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		2
79	{ "_time" },
80#define	X_DUMPSIZE	3
81	{ "_dumpsize" },
82#define	X_VERSION	4
83	{ "_version" },
84#define	X_DUMPMAG	5
85	{ "_dumpmag" },
86#define	X_PANICSTR	6
87	{ "_panicstr" },
88#define	X_PANICSTART	7
89	{ "_panicstart" },
90#define	X_PANICEND	8
91	{ "_panicend" },
92#define	X_MSGBUF	9
93	{ "_msgbufp" },
94	{ NULL },
95};
96int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
97int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
98
99struct nlist dump_nl[] = {	/* Name list for dumped system. */
100	{ "_dumpdev" },		/* Entries MUST be the same as */
101	{ "_dumplo" },		/*	those in current_nl[].  */
102	{ "_time" },
103	{ "_dumpsize" },
104	{ "_version" },
105	{ "_dumpmag" },
106	{ "_panicstr" },
107	{ "_panicstart" },
108	{ "_panicend" },
109	{ "_msgbufp" },
110	{ NULL },
111};
112
113/* Types match kernel declarations. */
114off_t	dumplo;				/* where dump starts on dumpdev */
115u_int32_t dumpmag;			/* magic number in dump */
116int	dumpsize;			/* amount of memory dumped */
117off_t dumpbytes;			/* in bytes */
118
119const char	*kernel;		/* name of used kernel */
120char	*dirname;			/* directory to save dumps in */
121char	*ddname;			/* name of dump device */
122dev_t	dumpdev;			/* dump device */
123int	dumpfd;				/* read/write descriptor on block dev */
124kvm_t	*kd_dump;			/* kvm descriptor on block dev	*/
125time_t	now;				/* current date */
126char	panic_mesg[1024];
127long	panicstr;
128char	vers[1024];
129char	gzmode[3];
130
131static int	clear, compress, force, verbose;	/* flags */
132
133void	check_kmem(void);
134int	check_space(void);
135void	clear_dump(void);
136int	Create(char *, int);
137int	dump_exists(void);
138char	*find_dev(dev_t, int);
139int	get_crashtime(void);
140void	kmem_setup(void);
141void	Lseek(int, off_t, int);
142int	main(int, char *[]);
143int	Open(const char *, int rw);
144char	*rawname(char *s);
145void	save_core(void);
146void	usage(void);
147void	Write(int, void *, int);
148
149int
150main(int argc, char *argv[])
151{
152	int ch, level;
153	char *ep;
154
155	dirname = NULL;
156	kernel = NULL;
157	level = 1;		/* default to fastest gzip compression */
158	gzmode[0] = 'w';
159
160	openlog("savecore", LOG_PERROR, LOG_DAEMON);
161
162	while ((ch = getopt(argc, argv, "cdfN:vzZ:")) != -1)
163		switch(ch) {
164		case 'c':
165			clear = 1;
166			break;
167		case 'd':		/* Not documented. */
168		case 'v':
169			verbose = 1;
170			break;
171		case 'f':
172			force = 1;
173			break;
174		case 'N':
175			kernel = optarg;
176			break;
177		case 'z':
178			compress = 1;
179			break;
180		case 'Z':
181			level = (int)strtol(optarg, &ep, 10);
182			if (level < 0 || level > 9) {
183				(void)syslog(LOG_ERR, "invalid compression %s",
184				    optarg);
185				usage();
186			}
187			break;
188		case '?':
189		default:
190			usage();
191		}
192	argc -= optind;
193	argv += optind;
194
195	if (argc != (clear ? 0 : 1))
196		usage();
197
198	gzmode[1] = level + '0';
199	if (!clear)
200		dirname = argv[0];
201
202	if (kernel == NULL) {
203		kernel = getbootfile();
204	}
205
206	(void)time(&now);
207	kmem_setup();
208
209	if (clear) {
210		clear_dump();
211		exit(0);
212	}
213
214	if (!dump_exists() && !force)
215		exit(1);
216
217	check_kmem();
218
219	if (panicstr)
220		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
221	else
222		syslog(LOG_ALERT, "reboot");
223
224	if ((!get_crashtime() || !check_space()) && !force)
225		exit(1);
226
227	save_core();
228
229	clear_dump();
230	exit(0);
231}
232
233void
234kmem_setup(void)
235{
236	kvm_t *kd_kern;
237	char errbuf[_POSIX2_LINE_MAX];
238	int i, hdrsz;
239
240	/*
241	 * Some names we need for the currently running system, others for
242	 * the system that was running when the dump was made.  The values
243	 * obtained from the current system are used to look for things in
244	 * /dev/kmem that cannot be found in the kernel namelist, but are
245	 * presumed to be the same (since the disk partitions are probably
246	 * the same!)
247	 */
248	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
249	if (kd_kern == NULL) {
250		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
251		exit(1);
252	}
253	if (kvm_nlist(kd_kern, current_nl) == -1)
254		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
255		    kvm_geterr(kd_kern));
256
257	for (i = 0; cursyms[i] != -1; i++)
258		if (current_nl[cursyms[i]].n_value == 0) {
259			syslog(LOG_ERR, "%s: %s not in namelist",
260			    kernel, current_nl[cursyms[i]].n_name);
261			exit(1);
262		}
263
264	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
265		if (verbose)
266		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
267		exit(1);
268	}
269	if (dumpdev == NODEV) {
270		syslog(LOG_WARNING, "no core dump (no dumpdev)");
271		exit(1);
272	}
273	{
274	    long l_dumplo;
275
276	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
277		    if (verbose)
278			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
279		    exit(1);
280	    }
281	    if (l_dumplo == -1) {
282		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
283		exit(1);
284	    }
285	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
286	}
287
288	if (verbose)
289		(void)printf("dumplo = %lld (%ld * %ld)\n",
290		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
291	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
292		if (verbose)
293		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
294		exit(1);
295	}
296
297	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
298	    sizeof(vers));
299	vers[sizeof(vers) - 1] = '\0';
300
301	ddname = find_dev(dumpdev, S_IFBLK);
302	dumpfd = Open(ddname, O_RDWR);
303
304	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
305	if (kd_dump == NULL) {
306		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
307		exit(1);
308	}
309
310	if (kvm_nlist(kd_dump, dump_nl) == -1)
311		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
312		    kvm_geterr(kd_dump));
313
314	for (i = 0; dumpsyms[i] != -1; i++)
315		if (dump_nl[dumpsyms[i]].n_value == 0) {
316			syslog(LOG_ERR, "%s: %s not in namelist",
317			    kernel, dump_nl[dumpsyms[i]].n_name);
318			exit(1);
319		}
320	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
321
322	/*
323	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
324	 * checks, ergo no dump is present...
325	 */
326	if (hdrsz == 0) {
327		syslog(LOG_WARNING, "no core dump");
328		exit(1);
329	}
330	if (hdrsz == -1) {
331		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
332		    kvm_geterr(kd_dump));
333		exit(1);
334	}
335	dumplo += hdrsz;
336	kvm_close(kd_kern);
337}
338
339void
340check_kmem(void)
341{
342	char *cp, *bufdata;
343	struct kern_msgbuf msgbuf, *bufp;
344	long panicloc, panicstart, panicend;
345	char core_vers[1024];
346
347	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
348	    sizeof(core_vers));
349	core_vers[sizeof(core_vers) - 1] = '\0';
350
351	if (strcmp(vers, core_vers) != 0)
352		syslog(LOG_WARNING,
353		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
354		    kernel, vers, core_vers);
355
356	panicstart = panicend = 0;
357	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
358		if (verbose)
359		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
360		goto nomsguf;
361	}
362	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
363		if (verbose)
364		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
365		goto nomsguf;
366	}
367	if (panicstart != 0 && panicend != 0) {
368		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
369			if (verbose)
370				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
371			goto nomsguf;
372		}
373		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
374		    offsetof(struct kern_msgbuf, msg_bufc)) !=
375		    offsetof(struct kern_msgbuf, msg_bufc)) {
376			if (verbose)
377				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
378			goto nomsguf;
379		}
380		if (msgbuf.msg_magic != MSG_MAGIC) {
381			if (verbose)
382				syslog(LOG_WARNING, "msgbuf magic incorrect");
383			goto nomsguf;
384		}
385		bufdata = malloc(msgbuf.msg_bufs);
386		if (bufdata == NULL) {
387			if (verbose)
388				syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
389			goto nomsguf;
390		}
391		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
392		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
393			if (verbose)
394				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
395			goto nomsguf;
396		}
397		cp = panic_mesg;
398		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
399			*cp++ = bufdata[panicstart];
400			panicstart++;
401			if (panicstart >= msgbuf.msg_bufs)
402				panicstart = 0;
403		}
404		/* Don't end in a new-line */
405		cp = &panic_mesg[strlen(panic_mesg)] - 1;
406		if (*cp == '\n')
407			*cp = '\0';
408		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
409
410		panicstr = 1;	/* anything not zero */
411		return;
412	}
413nomsguf:
414	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
415		if (verbose)
416		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
417		return;
418	}
419	if (panicstr) {
420		cp = panic_mesg;
421		panicloc = panicstr;
422		do {
423			if (KREAD(kd_dump, panicloc, cp) != 0) {
424				if (verbose)
425				    syslog(LOG_WARNING, "kvm_read: %s",
426					kvm_geterr(kd_dump));
427				break;
428			}
429			panicloc++;
430		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
431		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
432	}
433}
434
435int
436dump_exists(void)
437{
438	u_int32_t newdumpmag;
439
440	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
441		if (verbose)
442		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
443		return (0);
444	}
445
446	/* Read the dump size. */
447	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
448		if (verbose)
449		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
450		return (0);
451	}
452	dumpbytes = (off_t)dumpsize * getpagesize();
453
454	/*
455	 * Return zero if core dump doesn't seem to be there, and note
456	 * it for syslog.  This check and return happens after the dump size
457	 * is read, so dumpsize is whether or not the core is valid (for -f).
458	 */
459	if (newdumpmag != dumpmag) {
460		if (verbose)
461			syslog(LOG_WARNING,
462			    "magic number mismatch (0x%x != 0x%x)",
463			    newdumpmag, dumpmag);
464		syslog(LOG_WARNING, "no core dump");
465		return (0);
466	}
467	return (1);
468}
469
470void
471clear_dump(void)
472{
473	if (kvm_dump_inval(kd_dump) == -1)
474		syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
475		    kvm_geterr(kd_dump));
476
477}
478
479char buf[1024 * 1024];
480
481void
482save_core(void)
483{
484	FILE *fp;
485	int bounds, ifd, nr, nw, ofd;
486	char *rawp, path[MAXPATHLEN];
487
488	ofd = -1;
489	/*
490	 * Get the current number and update the bounds file.  Do the update
491	 * now, because may fail later and don't want to overwrite anything.
492	 */
493	umask(066);
494	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
495	if ((fp = fopen(path, "r")) == NULL)
496		goto err1;
497	if (fgets(buf, sizeof(buf), fp) == NULL) {
498		if (ferror(fp))
499err1:			syslog(LOG_WARNING, "%s: %m", path);
500		bounds = 0;
501	} else
502		bounds = atoi(buf);
503	if (fp != NULL)
504		(void)fclose(fp);
505	if ((fp = fopen(path, "w")) == NULL)
506		syslog(LOG_ERR, "%s: %m", path);
507	else {
508		(void)fprintf(fp, "%d\n", bounds + 1);
509		(void)fclose(fp);
510	}
511
512	/* Create the core file. */
513	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
514	    dirname, bounds, compress ? ".gz" : "");
515	if (compress) {
516		if ((fp = zopen(path, gzmode)) == NULL) {
517			syslog(LOG_ERR, "%s: %m", path);
518			exit(1);
519		}
520	} else {
521		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
522		fp  = fdopen(ofd, "w");
523		if (fp == NULL) {
524			syslog(LOG_ERR, "%s: fdopen: %m", path);
525			exit(1);
526		}
527	}
528
529	/* Open the raw device. */
530	rawp = rawname(ddname);
531	if ((ifd = open(rawp, O_RDONLY)) == -1) {
532		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
533		ifd = dumpfd;
534	}
535
536	/* Seek to the start of the core. */
537	Lseek(ifd, dumplo, SEEK_SET);
538
539	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
540		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
541		    kvm_geterr(kd_dump));
542		exit(1);
543	}
544
545	/* Copy the core file. */
546	syslog(LOG_NOTICE, "writing %score to %s",
547	    compress ? "compressed " : "", path);
548	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
549		char nbuf[7];
550		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
551		(void)printf("%7s\r", nbuf);
552		(void)fflush(stdout);
553		nr = read(ifd, buf, MIN(dumpbytes, sizeof(buf)));
554		if (nr <= 0) {
555			if (nr == 0)
556				syslog(LOG_WARNING,
557				    "WARNING: EOF on dump device");
558			else
559				syslog(LOG_ERR, "%s: %m", rawp);
560			goto err2;
561		}
562		nw = fwrite(buf, 1, nr, fp);
563		if (nw != nr) {
564			syslog(LOG_ERR, "%s: %s",
565			    path, strerror(nw == 0 ? EIO : errno));
566err2:			syslog(LOG_WARNING,
567			    "WARNING: core may be incomplete");
568			(void)printf("\n");
569			exit(1);
570		}
571	}
572	(void)close(ifd);
573	(void)fclose(fp);
574
575	/* Copy the kernel. */
576	ifd = Open(kernel, O_RDONLY);
577	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
578	    dirname, bounds, compress ? ".gz" : "");
579	if (compress) {
580		if ((fp = zopen(path, gzmode)) == NULL) {
581			syslog(LOG_ERR, "%s: %m", path);
582			exit(1);
583		}
584	} else
585		ofd = Create(path, S_IRUSR | S_IWUSR);
586	syslog(LOG_NOTICE, "writing %skernel to %s",
587	    compress ? "compressed " : "", path);
588	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
589		if (compress)
590			nw = fwrite(buf, 1, nr, fp);
591		else
592			nw = write(ofd, buf, nr);
593		if (nw != nr) {
594			syslog(LOG_ERR, "%s: %s",
595			    path, strerror(nw == 0 ? EIO : errno));
596			syslog(LOG_WARNING,
597			    "WARNING: kernel may be incomplete");
598			exit(1);
599		}
600	}
601	if (nr < 0) {
602		syslog(LOG_ERR, "%s: %m", kernel);
603		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
604		exit(1);
605	}
606	if (compress)
607		(void)fclose(fp);
608	else
609		(void)close(ofd);
610}
611
612char *
613find_dev(dev_t dev, int type)
614{
615	DIR *dfd;
616	struct dirent *dir;
617	struct stat sb;
618	char *dp, device[MAXPATHLEN + 1], *p;
619	size_t l;
620
621	if ((dfd = opendir(_PATH_DEV)) == NULL) {
622		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
623		exit(1);
624	}
625	strlcpy(device, _PATH_DEV, sizeof(device));
626	p = &device[strlen(device)];
627	l = sizeof(device) - strlen(device);
628	while ((dir = readdir(dfd))) {
629		strlcpy(p, dir->d_name, l);
630		if (lstat(device, &sb)) {
631			syslog(LOG_ERR, "%s: %m", device);
632			continue;
633		}
634		if ((sb.st_mode & S_IFMT) != type)
635			continue;
636		if (dev == sb.st_rdev) {
637			closedir(dfd);
638			if ((dp = strdup(device)) == NULL) {
639				syslog(LOG_ERR, "%m");
640				exit(1);
641			}
642			return (dp);
643		}
644	}
645	closedir(dfd);
646	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
647	exit(1);
648}
649
650char *
651rawname(char *s)
652{
653	char *sl;
654	char name[MAXPATHLEN];
655
656	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
657		syslog(LOG_ERR,
658		    "can't make raw dump device name from %s", s);
659		return (s);
660	}
661	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
662	    sl + 1);
663	if ((sl = strdup(name)) == NULL) {
664		syslog(LOG_ERR, "%m");
665		exit(1);
666	}
667	return (sl);
668}
669
670int
671get_crashtime(void)
672{
673	struct timeval dtime;
674	time_t dumptime;			/* Time the dump was taken. */
675
676	if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
677		if (verbose)
678		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
679		return (0);
680	}
681	dumptime = dtime.tv_sec;
682	if (dumptime == 0) {
683		if (verbose)
684			syslog(LOG_ERR, "dump time is zero");
685		return (0);
686	}
687	(void)printf("savecore: system went down at %s", ctime(&dumptime));
688#define	LEEWAY	(60 * SECSPERDAY)
689	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
690		(void)printf("dump time is unreasonable\n");
691		return (0);
692	}
693	return (1);
694}
695
696int
697check_space(void)
698{
699	FILE *fp;
700	off_t minfree, spacefree, kernelsize, needed;
701	struct stat st;
702	struct statvfs fsbuf;
703	char mbuf[100], path[MAXPATHLEN];
704
705#ifdef __GNUC__
706	(void) &minfree;
707#endif
708
709	if (stat(kernel, &st) < 0) {
710		syslog(LOG_ERR, "%s: %m", kernel);
711		exit(1);
712	}
713	kernelsize = st.st_blocks * S_BLKSIZE;
714	if (statvfs(dirname, &fsbuf) < 0) {
715		syslog(LOG_ERR, "%s: %m", dirname);
716		exit(1);
717	}
718	spacefree = fsbuf.f_bavail;
719	spacefree *= fsbuf.f_frsize;
720	spacefree /= 1024;
721
722	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
723	if ((fp = fopen(path, "r")) == NULL)
724		minfree = 0;
725	else {
726		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
727			minfree = 0;
728		else
729			minfree = atoi(mbuf);
730		(void)fclose(fp);
731	}
732
733	needed = (dumpbytes + kernelsize) / 1024;
734 	if (minfree > 0 && spacefree - needed < minfree) {
735		syslog(LOG_WARNING,
736		    "no dump, not enough free space in %s", dirname);
737		return (0);
738	}
739	if (spacefree - needed < minfree)
740		syslog(LOG_WARNING,
741		    "dump performed, but free space threshold crossed");
742	return (1);
743}
744
745int
746Open(const char *name, int rw)
747{
748	int fd;
749
750	if ((fd = open(name, rw, 0)) < 0) {
751		syslog(LOG_ERR, "%s: %m", name);
752		exit(1);
753	}
754	return (fd);
755}
756
757void
758Lseek(int fd, off_t off, int flag)
759{
760	off_t ret;
761
762	ret = lseek(fd, off, flag);
763	if (ret == -1) {
764		syslog(LOG_ERR, "lseek: %m");
765		exit(1);
766	}
767}
768
769int
770Create(char *file, int mode)
771{
772	int fd;
773
774	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
775	if (fd < 0) {
776		syslog(LOG_ERR, "%s: %m", file);
777		exit(1);
778	}
779	return (fd);
780}
781
782void
783Write(int fd, void *bp, int size)
784{
785	int n;
786
787	if ((n = write(fd, bp, size)) < size) {
788		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
789		exit(1);
790	}
791}
792
793void
794usage(void)
795{
796	(void)syslog(LOG_ERR,
797	    "usage: savecore [-cfvz] [-N system] [-Z level] directory");
798	exit(1);
799}
800