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savecore.c revision 1.72
      1 /*	$NetBSD: savecore.c,v 1.72 2008/01/15 14:26:42 ad 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 1.72 2008/01/15 14:26:42 ad 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 char *
    658 find_dev(dev_t dev, int type)
    659 {
    660 	DIR *dfd;
    661 	struct dirent *dir;
    662 	struct stat sb;
    663 	char *dp, device[MAXPATHLEN + 1], *p;
    664 	size_t l;
    665 
    666 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
    667 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
    668 		exit(1);
    669 	}
    670 	strlcpy(device, _PATH_DEV, sizeof(device));
    671 	p = &device[strlen(device)];
    672 	l = sizeof(device) - strlen(device);
    673 	while ((dir = readdir(dfd))) {
    674 		strlcpy(p, dir->d_name, l);
    675 		if (lstat(device, &sb)) {
    676 			syslog(LOG_ERR, "%s: %m", device);
    677 			continue;
    678 		}
    679 		if ((sb.st_mode & S_IFMT) != type)
    680 			continue;
    681 		if (dev == sb.st_rdev) {
    682 			closedir(dfd);
    683 			if ((dp = strdup(device)) == NULL) {
    684 				syslog(LOG_ERR, "%m");
    685 				exit(1);
    686 			}
    687 			return (dp);
    688 		}
    689 	}
    690 	closedir(dfd);
    691 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
    692 	exit(1);
    693 }
    694 
    695 char *
    696 rawname(char *s)
    697 {
    698 	char *sl;
    699 	char name[MAXPATHLEN];
    700 
    701 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
    702 		syslog(LOG_ERR,
    703 		    "can't make raw dump device name from %s", s);
    704 		return (s);
    705 	}
    706 	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
    707 	    sl + 1);
    708 	if ((sl = strdup(name)) == NULL) {
    709 		syslog(LOG_ERR, "%m");
    710 		exit(1);
    711 	}
    712 	return (sl);
    713 }
    714 
    715 int
    716 get_crashtime(void)
    717 {
    718 	time_t dumptime;			/* Time the dump was taken. */
    719 	struct timeval dtime;
    720 
    721 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
    722 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
    723 			if (verbose)
    724 				syslog(LOG_WARNING, "kvm_read: %s (and _time_second is not defined also)", kvm_geterr(kd_dump));
    725 			return (0);
    726 		}
    727 		dumptime = dtime.tv_sec;
    728 	}
    729 	if (dumptime == 0) {
    730 		if (verbose)
    731 			syslog(LOG_ERR, "dump time is zero");
    732 		return (0);
    733 	}
    734 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
    735 #define	LEEWAY	(60 * SECSPERDAY)
    736 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
    737 		(void)printf("dump time is unreasonable\n");
    738 		return (0);
    739 	}
    740 	return (1);
    741 }
    742 
    743 int
    744 check_space(void)
    745 {
    746 	FILE *fp;
    747 	off_t minfree, spacefree, kernelsize, needed;
    748 	struct stat st;
    749 	struct statvfs fsbuf;
    750 	char mbuf[100], path[MAXPATHLEN];
    751 
    752 	if (stat(kernel, &st) < 0) {
    753 		syslog(LOG_ERR, "%s: %m", kernel);
    754 		exit(1);
    755 	}
    756 	kernelsize = st.st_blocks * S_BLKSIZE;
    757 	if (statvfs(dirname, &fsbuf) < 0) {
    758 		syslog(LOG_ERR, "%s: %m", dirname);
    759 		exit(1);
    760 	}
    761 	spacefree = fsbuf.f_bavail;
    762 	spacefree *= fsbuf.f_frsize;
    763 	spacefree /= 1024;
    764 
    765 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
    766 	if ((fp = fopen(path, "r")) == NULL)
    767 		minfree = 0;
    768 	else {
    769 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
    770 			minfree = 0;
    771 		else
    772 			minfree = atoi(mbuf);
    773 		(void)fclose(fp);
    774 	}
    775 
    776 	needed = (dumpbytes + kernelsize) / 1024;
    777  	if (minfree > 0 && spacefree - needed < minfree) {
    778 		syslog(LOG_WARNING,
    779 		    "no dump, not enough free space in %s", dirname);
    780 		return (0);
    781 	}
    782 	if (spacefree - needed < minfree)
    783 		syslog(LOG_WARNING,
    784 		    "dump performed, but free space threshold crossed");
    785 	return (1);
    786 }
    787 
    788 int
    789 Open(const char *name, int rw)
    790 {
    791 	int fd;
    792 
    793 	if ((fd = open(name, rw, 0)) < 0) {
    794 		syslog(LOG_ERR, "%s: %m", name);
    795 		exit(1);
    796 	}
    797 	return (fd);
    798 }
    799 
    800 void
    801 Lseek(int fd, off_t off, int flag)
    802 {
    803 	off_t ret;
    804 
    805 	ret = lseek(fd, off, flag);
    806 	if (ret == -1) {
    807 		syslog(LOG_ERR, "lseek: %m");
    808 		exit(1);
    809 	}
    810 }
    811 
    812 int
    813 Create(char *file, int mode)
    814 {
    815 	int fd;
    816 
    817 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
    818 	if (fd < 0) {
    819 		syslog(LOG_ERR, "%s: %m", file);
    820 		exit(1);
    821 	}
    822 	return (fd);
    823 }
    824 
    825 void
    826 Write(int fd, void *bp, int size)
    827 {
    828 	int n;
    829 
    830 	if ((n = write(fd, bp, size)) < size) {
    831 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
    832 		exit(1);
    833 	}
    834 }
    835 
    836 void
    837 usage(void)
    838 {
    839 	(void)syslog(LOG_ERR,
    840 	    "usage: savecore [-cfnvz] [-N system] [-Z level] directory");
    841 	exit(1);
    842 }
    843