Home | History | Annotate | Line # | Download | only in savecore
savecore.c revision 1.32
      1 /*	$NetBSD: savecore.c,v 1.32 1997/09/15 11:08:45 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)savecore.c	8.3 (Berkeley) 1/2/94";
     45 #else
     46 __RCSID("$NetBSD: savecore.c,v 1.32 1997/09/15 11:08:45 lukem Exp $");
     47 #endif
     48 #endif /* not lint */
     49 
     50 #include <sys/param.h>
     51 #include <sys/stat.h>
     52 #include <sys/mount.h>
     53 #include <sys/syslog.h>
     54 #include <sys/time.h>
     55 
     56 #include <dirent.h>
     57 #include <errno.h>
     58 #include <fcntl.h>
     59 #include <nlist.h>
     60 #include <paths.h>
     61 #include <stdio.h>
     62 #include <stdlib.h>
     63 #include <string.h>
     64 #include <tzfile.h>
     65 #include <unistd.h>
     66 #include <limits.h>
     67 #include <kvm.h>
     68 
     69 extern FILE *zopen __P((const char *fname, const char *mode, int bits));
     70 
     71 #define KREAD(kd, addr, p)\
     72 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
     73 
     74 struct nlist current_nl[] = {	/* Namelist for currently running system. */
     75 #define X_DUMPDEV	0
     76 	{ "_dumpdev" },
     77 #define X_DUMPLO	1
     78 	{ "_dumplo" },
     79 #define X_TIME		2
     80 	{ "_time" },
     81 #define	X_DUMPSIZE	3
     82 	{ "_dumpsize" },
     83 #define X_VERSION	4
     84 	{ "_version" },
     85 #define X_PANICSTR	5
     86 	{ "_panicstr" },
     87 #define	X_DUMPMAG	6
     88 	{ "_dumpmag" },
     89 	{ NULL },
     90 };
     91 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
     92 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
     93 
     94 struct nlist dump_nl[] = {	/* Name list for dumped system. */
     95 	{ "_dumpdev" },		/* Entries MUST be the same as */
     96 	{ "_dumplo" },		/*	those in current_nl[].  */
     97 	{ "_time" },
     98 	{ "_dumpsize" },
     99 	{ "_version" },
    100 	{ "_panicstr" },
    101 	{ "_dumpmag" },
    102 	{ NULL },
    103 };
    104 
    105 /* Types match kernel declarations. */
    106 long	dumplo;				/* where dump starts on dumpdev */
    107 int	dumpmag;			/* magic number in dump */
    108 int	dumpsize;			/* amount of memory dumped */
    109 
    110 char	*kernel;
    111 char	*dirname;			/* directory to save dumps in */
    112 char	*ddname;			/* name of dump device */
    113 dev_t	dumpdev;			/* dump device */
    114 int	dumpfd;				/* read/write descriptor on block dev */
    115 kvm_t	*kd_dump;			/* kvm descriptor on block dev	*/
    116 time_t	now;				/* current date */
    117 char	panic_mesg[1024];
    118 long	panicstr;
    119 char	vers[1024];
    120 
    121 int	clear, compress, force, verbose;	/* flags */
    122 
    123 void	 check_kmem __P((void));
    124 int	 check_space __P((void));
    125 void	 clear_dump __P((void));
    126 int	 Create __P((char *, int));
    127 int	 dump_exists __P((void));
    128 char	*find_dev __P((dev_t, int));
    129 int	 get_crashtime __P((void));
    130 void	 kmem_setup __P((void));
    131 void	 log __P((int, char *, ...));
    132 void	 Lseek __P((int, off_t, int));
    133 int	 main __P((int, char *[]));
    134 int	 Open __P((char *, int rw));
    135 char	*rawname __P((char *s));
    136 void	 save_core __P((void));
    137 void	 usage __P((void));
    138 void	 Write __P((int, void *, int));
    139 
    140 int
    141 main(argc, argv)
    142 	int argc;
    143 	char *argv[];
    144 {
    145 	int ch;
    146 
    147 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
    148 
    149 	while ((ch = getopt(argc, argv, "cdfN:vz")) != -1)
    150 		switch(ch) {
    151 		case 'c':
    152 			clear = 1;
    153 			break;
    154 		case 'd':		/* Not documented. */
    155 		case 'v':
    156 			verbose = 1;
    157 			break;
    158 		case 'f':
    159 			force = 1;
    160 			break;
    161 		case 'N':
    162 			kernel = optarg;
    163 			break;
    164 		case 'z':
    165 			compress = 1;
    166 			break;
    167 		case '?':
    168 		default:
    169 			usage();
    170 		}
    171 	argc -= optind;
    172 	argv += optind;
    173 
    174 	if (!clear) {
    175 		if (argc != 1 && argc != 2)
    176 			usage();
    177 		dirname = argv[0];
    178 	}
    179 	if (argc == 2)
    180 		kernel = argv[1];
    181 
    182 	(void)time(&now);
    183 	kmem_setup();
    184 
    185 	if (clear) {
    186 		clear_dump();
    187 		exit(0);
    188 	}
    189 
    190 	if (!dump_exists() && !force)
    191 		exit(1);
    192 
    193 	check_kmem();
    194 
    195 	if (panicstr)
    196 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
    197 	else
    198 		syslog(LOG_ALERT, "reboot");
    199 
    200 	if ((!get_crashtime() || !check_space()) && !force)
    201 		exit(1);
    202 
    203 	save_core();
    204 
    205 	clear_dump();
    206 	exit(0);
    207 }
    208 
    209 void
    210 kmem_setup()
    211 {
    212 	kvm_t	*kd_kern;
    213 	char	errbuf[_POSIX2_LINE_MAX];
    214 	int	i, hdrsz;
    215 	char	*dump_sys;
    216 
    217 	/*
    218 	 * Some names we need for the currently running system, others for
    219 	 * the system that was running when the dump was made.  The values
    220 	 * obtained from the current system are used to look for things in
    221 	 * /dev/kmem that cannot be found in the dump_sys namelist, but are
    222 	 * presumed to be the same (since the disk partitions are probably
    223 	 * the same!)
    224 	 */
    225 	kd_kern = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
    226 	if (kd_kern == NULL) {
    227 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", _PATH_UNIX, errbuf);
    228 		exit(1);
    229 	}
    230 	if (kvm_nlist(kd_kern, current_nl) == -1)
    231 		syslog(LOG_ERR, "%s: kvm_nlist: %s", _PATH_UNIX,
    232 			kvm_geterr(kd_kern));
    233 
    234 	for (i = 0; cursyms[i] != -1; i++)
    235 		if (current_nl[cursyms[i]].n_value == 0) {
    236 			syslog(LOG_ERR, "%s: %s not in namelist",
    237 			    _PATH_UNIX, current_nl[cursyms[i]].n_name);
    238 			exit(1);
    239 		}
    240 
    241 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
    242 		if (verbose)
    243 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    244 		exit(1);
    245 	}
    246 	if (dumpdev == NODEV) {
    247 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
    248 		exit(1);
    249 	}
    250 	if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &dumplo) != 0) {
    251 		if (verbose)
    252 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    253 		exit(1);
    254 	}
    255 	dumplo *= DEV_BSIZE;
    256 	if (verbose)
    257 		(void)printf("dumplo = %ld (%ld * %ld)\n",
    258 		    (long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
    259 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
    260 		if (verbose)
    261 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    262 		exit(1);
    263 	}
    264 
    265 	if (kernel == NULL) {
    266 		(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value,
    267 			vers, sizeof(vers));
    268 		vers[sizeof(vers) - 1] = '\0';
    269 	}
    270 
    271 	ddname = find_dev(dumpdev, S_IFBLK);
    272 	dumpfd = Open(ddname, O_RDWR);
    273 
    274 	dump_sys = kernel ? kernel : _PATH_UNIX;
    275 
    276 	kd_dump = kvm_openfiles(dump_sys, ddname, NULL, O_RDWR, errbuf);
    277 	if (kd_dump == NULL) {
    278 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", dump_sys, errbuf);
    279 		exit(1);
    280 	}
    281 
    282 	if (kvm_nlist(kd_dump, dump_nl) == -1)
    283 		syslog(LOG_ERR, "%s: kvm_nlist: %s", dump_sys,
    284 			kvm_geterr(kd_dump));
    285 
    286 	for (i = 0; dumpsyms[i] != -1; i++)
    287 		if (dump_nl[dumpsyms[i]].n_value == 0) {
    288 			syslog(LOG_ERR, "%s: %s not in namelist",
    289 			    dump_sys, dump_nl[dumpsyms[i]].n_name);
    290 			exit(1);
    291 		}
    292 	hdrsz = kvm_dump_mkheader(kd_dump, (off_t)dumplo);
    293 
    294 	/*
    295 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
    296 	 * checks, ergo no dump is present...
    297 	 */
    298 	if (hdrsz == 0) {
    299 		syslog(LOG_WARNING, "no core dump");
    300 		exit(1);
    301 	}
    302 	if (hdrsz == -1) {
    303 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", dump_sys,
    304 			kvm_geterr(kd_dump));
    305 		exit(1);
    306 	}
    307 	dumplo += hdrsz;
    308 	kvm_close(kd_kern);
    309 }
    310 
    311 void
    312 check_kmem()
    313 {
    314 	char	*cp;
    315 	long	panicloc;
    316 	char core_vers[1024];
    317 
    318 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
    319 		sizeof(core_vers));
    320 	core_vers[sizeof(core_vers) - 1] = '\0';
    321 
    322 	if (strcmp(vers, core_vers) && kernel == 0)
    323 		syslog(LOG_WARNING,
    324 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
    325 		    _PATH_UNIX, vers, core_vers);
    326 
    327 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
    328 		if (verbose)
    329 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    330 		return;
    331 	}
    332 	if (panicstr) {
    333 		cp       = panic_mesg;
    334 		panicloc = panicstr;
    335 		do {
    336 			if (KREAD(kd_dump, panicloc, cp) != 0) {
    337 				if (verbose)
    338 				    syslog(LOG_WARNING, "kvm_read: %s",
    339 					   kvm_geterr(kd_dump));
    340 				break;
    341 			}
    342 			panicloc++;
    343 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
    344 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
    345 	}
    346 }
    347 
    348 int
    349 dump_exists()
    350 {
    351 	int newdumpmag;
    352 
    353 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
    354 		if (verbose)
    355 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    356 		return (0);
    357 	}
    358 
    359 	/* Read the dump size. */
    360 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
    361 		if (verbose)
    362 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    363 		return (0);
    364 	}
    365 	dumpsize *= getpagesize();
    366 
    367 	/*
    368 	 * Return zero if core dump doesn't seem to be there, and note
    369 	 * it for syslog.  This check and return happens after the dump size
    370 	 * is read, so dumpsize is whether or not the core is valid (for -f).
    371 	 */
    372 	if (newdumpmag != dumpmag) {
    373 		if (verbose)
    374 			syslog(LOG_WARNING,
    375 			    "magic number mismatch (0x%x != 0x%x)",
    376 			    newdumpmag, dumpmag);
    377 		syslog(LOG_WARNING, "no core dump");
    378 		return (0);
    379 	}
    380 	return (1);
    381 }
    382 
    383 void
    384 clear_dump()
    385 {
    386 	if (kvm_dump_inval(kd_dump) == -1)
    387 		syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
    388 			kvm_geterr(kd_dump));
    389 
    390 }
    391 
    392 char buf[1024 * 1024];
    393 
    394 void
    395 save_core()
    396 {
    397 	FILE *fp;
    398 	int bounds, ifd, nr, nw, ofd;
    399 	char *rawp, path[MAXPATHLEN];
    400 
    401 	ofd = -1;
    402 	/*
    403 	 * Get the current number and update the bounds file.  Do the update
    404 	 * now, because may fail later and don't want to overwrite anything.
    405 	 */
    406 	umask(002);
    407 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
    408 	if ((fp = fopen(path, "r")) == NULL)
    409 		goto err1;
    410 	if (fgets(buf, sizeof(buf), fp) == NULL) {
    411 		if (ferror(fp))
    412 err1:			syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
    413 		bounds = 0;
    414 	} else
    415 		bounds = atoi(buf);
    416 	if (fp != NULL)
    417 		(void)fclose(fp);
    418 	if ((fp = fopen(path, "w")) == NULL)
    419 		syslog(LOG_ERR, "%s: %m", path);
    420 	else {
    421 		(void)fprintf(fp, "%d\n", bounds + 1);
    422 		(void)fclose(fp);
    423 	}
    424 	(void)fclose(fp);
    425 
    426 	/* Create the core file. */
    427 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
    428 	    dirname, bounds, compress ? ".Z" : "");
    429 	if (compress) {
    430 		if ((fp = zopen(path, "w", 0)) == NULL) {
    431 			syslog(LOG_ERR, "%s: %s", path, strerror(errno));
    432 			exit(1);
    433 		}
    434 	} else {
    435 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
    436 		fp  = fdopen(ofd, "w");
    437 		if (fp == NULL) {
    438 			syslog(LOG_ERR, "%s: fdopen: %s", path,
    439 			    strerror(errno));
    440 			exit(1);
    441 		}
    442 	}
    443 
    444 	/* Open the raw device. */
    445 	rawp = rawname(ddname);
    446 	if ((ifd = open(rawp, O_RDONLY)) == -1) {
    447 		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
    448 		ifd = dumpfd;
    449 	}
    450 
    451 	/* Seek to the start of the core. */
    452 	Lseek(ifd, (off_t)dumplo, SEEK_SET);
    453 
    454 	if (kvm_dump_wrtheader(kd_dump, fp, dumpsize) == -1) {
    455 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
    456 			kvm_geterr(kd_dump));
    457 		exit(1);
    458 	}
    459 
    460 	/* Copy the core file. */
    461 	syslog(LOG_NOTICE, "writing %score to %s",
    462 	    compress ? "compressed " : "", path);
    463 	for (; dumpsize > 0; dumpsize -= nr) {
    464 		(void)printf("%6dK\r", dumpsize / 1024);
    465 		(void)fflush(stdout);
    466 		nr = read(ifd, buf, MIN(dumpsize, sizeof(buf)));
    467 		if (nr <= 0) {
    468 			if (nr == 0)
    469 				syslog(LOG_WARNING,
    470 				    "WARNING: EOF on dump device");
    471 			else
    472 				syslog(LOG_ERR, "%s: %m", rawp);
    473 			goto err2;
    474 		}
    475 		nw = fwrite(buf, 1, nr, fp);
    476 		if (nw != nr) {
    477 			syslog(LOG_ERR, "%s: %s",
    478 			    path, strerror(nw == 0 ? EIO : errno));
    479 err2:			syslog(LOG_WARNING,
    480 			    "WARNING: core may be incomplete");
    481 			(void)printf("\n");
    482 			exit(1);
    483 		}
    484 	}
    485 	(void)close(ifd);
    486 	(void)fclose(fp);
    487 
    488 	/* Copy the kernel. */
    489 	ifd = Open(kernel ? kernel : _PATH_UNIX, O_RDONLY);
    490 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
    491 	    dirname, bounds, compress ? ".Z" : "");
    492 	if (compress) {
    493 		if ((fp = zopen(path, "w", 0)) == NULL) {
    494 			syslog(LOG_ERR, "%s: %s", path, strerror(errno));
    495 			exit(1);
    496 		}
    497 	} else
    498 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
    499 	syslog(LOG_NOTICE, "writing %skernel to %s",
    500 	    compress ? "compressed " : "", path);
    501 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
    502 		if (compress)
    503 			nw = fwrite(buf, 1, nr, fp);
    504 		else
    505 			nw = write(ofd, buf, nr);
    506 		if (nw != nr) {
    507 			syslog(LOG_ERR, "%s: %s",
    508 			    path, strerror(nw == 0 ? EIO : errno));
    509 			syslog(LOG_WARNING,
    510 			    "WARNING: kernel may be incomplete");
    511 			exit(1);
    512 		}
    513 	}
    514 	if (nr < 0) {
    515 		syslog(LOG_ERR, "%s: %s",
    516 		    kernel ? kernel : _PATH_UNIX, strerror(errno));
    517 		syslog(LOG_WARNING,
    518 		    "WARNING: kernel may be incomplete");
    519 		exit(1);
    520 	}
    521 	if (compress)
    522 		(void)fclose(fp);
    523 	else
    524 		(void)close(ofd);
    525 }
    526 
    527 char *
    528 find_dev(dev, type)
    529 	dev_t dev;
    530 	int type;
    531 {
    532 	DIR *dfd;
    533 	struct dirent *dir;
    534 	struct stat sb;
    535 	char *dp, devname[MAXPATHLEN + 1];
    536 
    537 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
    538 		syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno));
    539 		exit(1);
    540 	}
    541 	(void)strcpy(devname, _PATH_DEV);
    542 	while ((dir = readdir(dfd))) {
    543 		(void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name);
    544 		if (lstat(devname, &sb)) {
    545 			syslog(LOG_ERR, "%s: %s", devname, strerror(errno));
    546 			continue;
    547 		}
    548 		if ((sb.st_mode & S_IFMT) != type)
    549 			continue;
    550 		if (dev == sb.st_rdev) {
    551 			closedir(dfd);
    552 			if ((dp = strdup(devname)) == NULL) {
    553 				syslog(LOG_ERR, "%s", strerror(errno));
    554 				exit(1);
    555 			}
    556 			return (dp);
    557 		}
    558 	}
    559 	closedir(dfd);
    560 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
    561 	exit(1);
    562 }
    563 
    564 char *
    565 rawname(s)
    566 	char *s;
    567 {
    568 	char *sl, name[MAXPATHLEN];
    569 
    570 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
    571 		syslog(LOG_ERR,
    572 		    "can't make raw dump device name from %s", s);
    573 		return (s);
    574 	}
    575 	(void)snprintf(name, sizeof(name), "%.*s/r%s", sl - s, s, sl + 1);
    576 	if ((sl = strdup(name)) == NULL) {
    577 		syslog(LOG_ERR, "%s", strerror(errno));
    578 		exit(1);
    579 	}
    580 	return (sl);
    581 }
    582 
    583 int
    584 get_crashtime()
    585 {
    586 	time_t dumptime;			/* Time the dump was taken. */
    587 
    588 	if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dumptime) != 0) {
    589 		if (verbose)
    590 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    591 		return (0);
    592 	}
    593 	if (dumptime == 0) {
    594 		if (verbose)
    595 			syslog(LOG_ERR, "dump time is zero");
    596 		return (0);
    597 	}
    598 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
    599 #define	LEEWAY	(7 * SECSPERDAY)
    600 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
    601 		(void)printf("dump time is unreasonable\n");
    602 		return (0);
    603 	}
    604 	return (1);
    605 }
    606 
    607 int
    608 check_space()
    609 {
    610 	FILE *fp;
    611 	char *tkernel;
    612 	off_t minfree, spacefree, kernelsize, needed;
    613 	struct stat st;
    614 	struct statfs fsbuf;
    615 	char buf[100], path[MAXPATHLEN];
    616 
    617 	tkernel = kernel ? kernel : _PATH_UNIX;
    618 	if (stat(tkernel, &st) < 0) {
    619 		syslog(LOG_ERR, "%s: %m", tkernel);
    620 		exit(1);
    621 	}
    622 	kernelsize = st.st_blocks * S_BLKSIZE;
    623 	if (statfs(dirname, &fsbuf) < 0) {
    624 		syslog(LOG_ERR, "%s: %m", dirname);
    625 		exit(1);
    626 	}
    627  	spacefree = (fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
    628 
    629 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
    630 	if ((fp = fopen(path, "r")) == NULL)
    631 		minfree = 0;
    632 	else {
    633 		if (fgets(buf, sizeof(buf), fp) == NULL)
    634 			minfree = 0;
    635 		else
    636 			minfree = atoi(buf);
    637 		(void)fclose(fp);
    638 	}
    639 
    640 	needed = (dumpsize + kernelsize) / 1024;
    641  	if (minfree > 0 && spacefree - needed < minfree) {
    642 		syslog(LOG_WARNING,
    643 		    "no dump, not enough free space on device");
    644 		return (0);
    645 	}
    646 	if (spacefree - needed < minfree)
    647 		syslog(LOG_WARNING,
    648 		    "dump performed, but free space threshold crossed");
    649 	return (1);
    650 }
    651 
    652 int
    653 Open(name, rw)
    654 	char *name;
    655 	int rw;
    656 {
    657 	int fd;
    658 
    659 	if ((fd = open(name, rw, 0)) < 0) {
    660 		syslog(LOG_ERR, "%s: %m", name);
    661 		exit(1);
    662 	}
    663 	return (fd);
    664 }
    665 
    666 void
    667 Lseek(fd, off, flag)
    668 	int fd, flag;
    669 	off_t off;
    670 {
    671 	off_t ret;
    672 
    673 	ret = lseek(fd, off, flag);
    674 	if (ret == -1) {
    675 		syslog(LOG_ERR, "lseek: %m");
    676 		exit(1);
    677 	}
    678 }
    679 
    680 int
    681 Create(file, mode)
    682 	char *file;
    683 	int mode;
    684 {
    685 	int fd;
    686 
    687 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
    688 	if (fd < 0) {
    689 		syslog(LOG_ERR, "%s: %m", file);
    690 		exit(1);
    691 	}
    692 	return (fd);
    693 }
    694 
    695 void
    696 Write(fd, bp, size)
    697 	int fd, size;
    698 	void *bp;
    699 {
    700 	int n;
    701 
    702 	if ((n = write(fd, bp, size)) < size) {
    703 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
    704 		exit(1);
    705 	}
    706 }
    707 
    708 void
    709 usage()
    710 {
    711 	(void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory");
    712 	exit(1);
    713 }
    714