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savecore.c revision 1.69
      1 /*	$NetBSD: savecore.c,v 1.69 2006/10/16 02:56:56 christos 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 1.69 2006/10/16 02:56:56 christos 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 	{ .n_name = NULL },
     97 };
     98 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
     99 int dumpsyms[] = { X_TIME_SECOND, X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG,
    100     -1 };
    101 
    102 struct nlist dump_nl[] = {	/* Name list for dumped system. */
    103 	{ .n_name = "_dumpdev" },	/* Entries MUST be the same as */
    104 	{ .n_name = "_dumplo" },	/*	those in current_nl[].  */
    105 	{ .n_name = "_time_second" },
    106 	{ .n_name = "_time" },
    107 	{ .n_name = "_dumpsize" },
    108 	{ .n_name = "_version" },
    109 	{ .n_name = "_dumpmag" },
    110 	{ .n_name = "_panicstr" },
    111 	{ .n_name = "_panicstart" },
    112 	{ .n_name = "_panicend" },
    113 	{ .n_name = "_msgbufp" },
    114 	{ .n_name = NULL },
    115 };
    116 
    117 /* Types match kernel declarations. */
    118 off_t	dumplo;				/* where dump starts on dumpdev */
    119 u_int32_t dumpmag;			/* magic number in dump */
    120 int	dumpsize;			/* amount of memory dumped */
    121 off_t dumpbytes;			/* in bytes */
    122 
    123 const char	*kernel;		/* name of used kernel */
    124 char	*dirname;			/* directory to save dumps in */
    125 char	*ddname;			/* name of dump device */
    126 dev_t	dumpdev;			/* dump device */
    127 int	dumpfd;				/* read/write descriptor on block dev */
    128 kvm_t	*kd_dump;			/* kvm descriptor on block dev	*/
    129 time_t	now;				/* current date */
    130 char	panic_mesg[1024];
    131 long	panicstr;
    132 char	vers[1024];
    133 char	gzmode[3];
    134 
    135 static int	clear, compress, force, verbose;	/* flags */
    136 
    137 void	check_kmem(void);
    138 int	check_space(void);
    139 void	clear_dump(void);
    140 int	Create(char *, int);
    141 int	dump_exists(void);
    142 char	*find_dev(dev_t, int);
    143 int	get_crashtime(void);
    144 void	kmem_setup(void);
    145 void	Lseek(int, off_t, int);
    146 int	main(int, char *[]);
    147 int	Open(const char *, int rw);
    148 char	*rawname(char *s);
    149 void	save_core(void);
    150 void	usage(void);
    151 void	Write(int, void *, int);
    152 
    153 int
    154 main(int argc, char *argv[])
    155 {
    156 	int ch, level, testonly;
    157 	char *ep;
    158 
    159 	dirname = NULL;
    160 	kernel = NULL;
    161 	level = 1;		/* default to fastest gzip compression */
    162 	testonly = 0;
    163 	gzmode[0] = 'w';
    164 
    165 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
    166 
    167 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
    168 		switch(ch) {
    169 		case 'c':
    170 			clear = 1;
    171 			break;
    172 		case 'd':		/* Not documented. */
    173 		case 'v':
    174 			verbose = 1;
    175 			break;
    176 		case 'f':
    177 			force = 1;
    178 			break;
    179 		case 'n':
    180 			testonly = 1;
    181 			break;
    182 		case 'N':
    183 			kernel = optarg;
    184 			break;
    185 		case 'z':
    186 			compress = 1;
    187 			break;
    188 		case 'Z':
    189 			level = (int)strtol(optarg, &ep, 10);
    190 			if (level < 0 || level > 9) {
    191 				(void)syslog(LOG_ERR, "invalid compression %s",
    192 				    optarg);
    193 				usage();
    194 			}
    195 			break;
    196 		case '?':
    197 		default:
    198 			usage();
    199 		}
    200 	argc -= optind;
    201 	argv += optind;
    202 
    203 	if (argc != ((clear || testonly) ? 0 : 1))
    204 		usage();
    205 
    206 	gzmode[1] = level + '0';
    207 	if (!clear)
    208 		dirname = argv[0];
    209 
    210 	if (kernel == NULL) {
    211 		kernel = getbootfile();
    212 	}
    213 
    214 	(void)time(&now);
    215 	kmem_setup();
    216 
    217 	if (clear && !testonly) {
    218 		clear_dump();
    219 		exit(0);
    220 	}
    221 
    222 	if (!dump_exists() && !force)
    223 		exit(1);
    224 
    225 	if (testonly)
    226 		/* If -n was passed and there was a dump, exit at level 0 */
    227 		exit(0);
    228 
    229 	check_kmem();
    230 
    231 	if (panicstr)
    232 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
    233 	else
    234 		syslog(LOG_ALERT, "reboot");
    235 
    236 	if ((!get_crashtime() || !check_space()) && !force)
    237 		exit(1);
    238 
    239 	save_core();
    240 
    241 	clear_dump();
    242 	exit(0);
    243 }
    244 
    245 void
    246 kmem_setup(void)
    247 {
    248 	kvm_t *kd_kern;
    249 	char errbuf[_POSIX2_LINE_MAX];
    250 	int i, hdrsz;
    251 
    252 	/*
    253 	 * Some names we need for the currently running system, others for
    254 	 * the system that was running when the dump was made.  The values
    255 	 * obtained from the current system are used to look for things in
    256 	 * /dev/kmem that cannot be found in the kernel namelist, but are
    257 	 * presumed to be the same (since the disk partitions are probably
    258 	 * the same!)
    259 	 */
    260 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
    261 	if (kd_kern == NULL) {
    262 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
    263 		exit(1);
    264 	}
    265 	if (kvm_nlist(kd_kern, current_nl) == -1)
    266 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
    267 		    kvm_geterr(kd_kern));
    268 
    269 	for (i = 0; cursyms[i] != -1; i++)
    270 		if (current_nl[cursyms[i]].n_value == 0 &&
    271 			cursyms[i] != X_TIME_SECOND &&
    272 		        cursyms[i] != X_TIME) {
    273 			syslog(LOG_ERR, "%s: %s not in namelist",
    274 			    kernel, current_nl[cursyms[i]].n_name);
    275 			exit(1);
    276 		}
    277 
    278 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
    279 		if (verbose)
    280 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    281 		exit(1);
    282 	}
    283 	if (dumpdev == NODEV) {
    284 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
    285 		exit(1);
    286 	}
    287 	{
    288 	    long l_dumplo;
    289 
    290 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
    291 		    if (verbose)
    292 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    293 		    exit(1);
    294 	    }
    295 	    if (l_dumplo == -1) {
    296 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
    297 		exit(1);
    298 	    }
    299 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
    300 	}
    301 
    302 	if (verbose)
    303 		(void)printf("dumplo = %lld (%ld * %ld)\n",
    304 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
    305 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
    306 		if (verbose)
    307 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    308 		exit(1);
    309 	}
    310 
    311 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
    312 	    sizeof(vers));
    313 	vers[sizeof(vers) - 1] = '\0';
    314 
    315 	ddname = find_dev(dumpdev, S_IFBLK);
    316 	dumpfd = Open(ddname, O_RDWR);
    317 
    318 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
    319 	if (kd_dump == NULL) {
    320 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
    321 		exit(1);
    322 	}
    323 
    324 	if (kvm_nlist(kd_dump, dump_nl) == -1)
    325 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
    326 		    kvm_geterr(kd_dump));
    327 
    328 	for (i = 0; dumpsyms[i] != -1; i++)
    329 		if (dump_nl[dumpsyms[i]].n_value == 0 &&
    330 			dumpsyms[i] != X_TIME_SECOND &&
    331 			dumpsyms[i] != X_TIME) {
    332 			syslog(LOG_ERR, "%s: %s not in namelist",
    333 			    kernel, dump_nl[dumpsyms[i]].n_name);
    334 			exit(1);
    335 		}
    336 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
    337 
    338 	/*
    339 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
    340 	 * checks, ergo no dump is present...
    341 	 */
    342 	if (hdrsz == 0) {
    343 		syslog(LOG_WARNING, "no core dump");
    344 		exit(1);
    345 	}
    346 	if (hdrsz == -1) {
    347 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
    348 		    kvm_geterr(kd_dump));
    349 		exit(1);
    350 	}
    351 	dumplo += hdrsz;
    352 	kvm_close(kd_kern);
    353 }
    354 
    355 void
    356 check_kmem(void)
    357 {
    358 	char *cp, *bufdata;
    359 	struct kern_msgbuf msgbuf, *bufp;
    360 	long panicloc, panicstart, panicend;
    361 	char core_vers[1024];
    362 
    363 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
    364 	    sizeof(core_vers));
    365 	core_vers[sizeof(core_vers) - 1] = '\0';
    366 
    367 	if (strcmp(vers, core_vers) != 0)
    368 		syslog(LOG_WARNING,
    369 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
    370 		    kernel, vers, core_vers);
    371 
    372 	panicstart = panicend = 0;
    373 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
    374 		if (verbose)
    375 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    376 		goto nomsguf;
    377 	}
    378 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
    379 		if (verbose)
    380 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    381 		goto nomsguf;
    382 	}
    383 	if (panicstart != 0 && panicend != 0) {
    384 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
    385 			if (verbose)
    386 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    387 			goto nomsguf;
    388 		}
    389 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
    390 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
    391 		    offsetof(struct kern_msgbuf, msg_bufc)) {
    392 			if (verbose)
    393 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    394 			goto nomsguf;
    395 		}
    396 		if (msgbuf.msg_magic != MSG_MAGIC) {
    397 			if (verbose)
    398 				syslog(LOG_WARNING, "msgbuf magic incorrect");
    399 			goto nomsguf;
    400 		}
    401 		bufdata = malloc(msgbuf.msg_bufs);
    402 		if (bufdata == NULL) {
    403 			if (verbose)
    404 				syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
    405 			goto nomsguf;
    406 		}
    407 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
    408 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
    409 			if (verbose)
    410 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    411 			free(bufdata);
    412 			goto nomsguf;
    413 		}
    414 		cp = panic_mesg;
    415 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
    416 			*cp++ = bufdata[panicstart];
    417 			panicstart++;
    418 			if (panicstart >= msgbuf.msg_bufs)
    419 				panicstart = 0;
    420 		}
    421 		/* Don't end in a new-line */
    422 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
    423 		if (*cp == '\n')
    424 			*cp = '\0';
    425 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
    426 		free(bufdata);
    427 
    428 		panicstr = 1;	/* anything not zero */
    429 		return;
    430 	}
    431 nomsguf:
    432 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
    433 		if (verbose)
    434 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    435 		return;
    436 	}
    437 	if (panicstr) {
    438 		cp = panic_mesg;
    439 		panicloc = panicstr;
    440 		do {
    441 			if (KREAD(kd_dump, panicloc, cp) != 0) {
    442 				if (verbose)
    443 				    syslog(LOG_WARNING, "kvm_read: %s",
    444 					kvm_geterr(kd_dump));
    445 				break;
    446 			}
    447 			panicloc++;
    448 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
    449 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
    450 	}
    451 }
    452 
    453 int
    454 dump_exists(void)
    455 {
    456 	u_int32_t newdumpmag;
    457 
    458 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
    459 		if (verbose)
    460 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    461 		return (0);
    462 	}
    463 
    464 	/* Read the dump size. */
    465 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
    466 		if (verbose)
    467 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    468 		return (0);
    469 	}
    470 	dumpbytes = (off_t)dumpsize * getpagesize();
    471 
    472 	/*
    473 	 * Return zero if core dump doesn't seem to be there, and note
    474 	 * it for syslog.  This check and return happens after the dump size
    475 	 * is read, so dumpsize is whether or not the core is valid (for -f).
    476 	 */
    477 	if (newdumpmag != dumpmag) {
    478 		if (verbose)
    479 			syslog(LOG_WARNING,
    480 			    "magic number mismatch (0x%x != 0x%x)",
    481 			    newdumpmag, dumpmag);
    482 		syslog(LOG_WARNING, "no core dump");
    483 		return (0);
    484 	}
    485 	return (1);
    486 }
    487 
    488 void
    489 clear_dump(void)
    490 {
    491 	if (kvm_dump_inval(kd_dump) == -1)
    492 		syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
    493 		    kvm_geterr(kd_dump));
    494 
    495 }
    496 
    497 char buf[1024 * 1024];
    498 
    499 void
    500 save_core(void)
    501 {
    502 	FILE *fp;
    503 	int bounds, ifd, nr, nw, ofd;
    504 	char *rawp, path[MAXPATHLEN];
    505 
    506 	ofd = -1;
    507 	/*
    508 	 * Get the current number and update the bounds file.  Do the update
    509 	 * now, because may fail later and don't want to overwrite anything.
    510 	 */
    511 	umask(066);
    512 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
    513 	if ((fp = fopen(path, "r")) == NULL)
    514 		goto err1;
    515 	if (fgets(buf, sizeof(buf), fp) == NULL) {
    516 		if (ferror(fp))
    517 err1:			syslog(LOG_WARNING, "%s: %m", path);
    518 		bounds = 0;
    519 	} else
    520 		bounds = atoi(buf);
    521 	if (fp != NULL)
    522 		(void)fclose(fp);
    523 	if ((fp = fopen(path, "w")) == NULL)
    524 		syslog(LOG_ERR, "%s: %m", path);
    525 	else {
    526 		(void)fprintf(fp, "%d\n", bounds + 1);
    527 		(void)fclose(fp);
    528 	}
    529 
    530 	/* Create the core file. */
    531 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
    532 	    dirname, bounds, compress ? ".gz" : "");
    533 	if (compress) {
    534 		if ((fp = zopen(path, gzmode)) == NULL) {
    535 			syslog(LOG_ERR, "%s: %m", path);
    536 			exit(1);
    537 		}
    538 	} else {
    539 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
    540 		fp  = fdopen(ofd, "w");
    541 		if (fp == NULL) {
    542 			syslog(LOG_ERR, "%s: fdopen: %m", path);
    543 			exit(1);
    544 		}
    545 	}
    546 
    547 	/* Open the raw device. */
    548 	rawp = rawname(ddname);
    549 	if ((ifd = open(rawp, O_RDONLY)) == -1) {
    550 		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
    551 		ifd = dumpfd;
    552 	}
    553 
    554 	/* Seek to the start of the core. */
    555 	Lseek(ifd, dumplo, SEEK_SET);
    556 
    557 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
    558 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
    559 		    kvm_geterr(kd_dump));
    560 		exit(1);
    561 	}
    562 
    563 	/* Copy the core file. */
    564 	syslog(LOG_NOTICE, "writing %score to %s",
    565 	    compress ? "compressed " : "", path);
    566 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
    567 		char nbuf[7];
    568 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
    569 		(void)printf("%7s\r", nbuf);
    570 		(void)fflush(stdout);
    571 		nr = read(ifd, buf, MIN(dumpbytes, sizeof(buf)));
    572 		if (nr <= 0) {
    573 			if (nr == 0)
    574 				syslog(LOG_WARNING,
    575 				    "WARNING: EOF on dump device");
    576 			else
    577 				syslog(LOG_ERR, "%s: %m", rawp);
    578 			goto err2;
    579 		}
    580 		nw = fwrite(buf, 1, nr, fp);
    581 		if (nw != nr) {
    582 			syslog(LOG_ERR, "%s: %s",
    583 			    path, strerror(nw == 0 ? EIO : errno));
    584 err2:			syslog(LOG_WARNING,
    585 			    "WARNING: core may be incomplete");
    586 			(void)printf("\n");
    587 			exit(1);
    588 		}
    589 	}
    590 	(void)close(ifd);
    591 	(void)fclose(fp);
    592 
    593 	/* Copy the kernel. */
    594 	ifd = Open(kernel, O_RDONLY);
    595 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
    596 	    dirname, bounds, compress ? ".gz" : "");
    597 	if (compress) {
    598 		if ((fp = zopen(path, gzmode)) == NULL) {
    599 			syslog(LOG_ERR, "%s: %m", path);
    600 			exit(1);
    601 		}
    602 	} else
    603 		ofd = Create(path, S_IRUSR | S_IWUSR);
    604 	syslog(LOG_NOTICE, "writing %skernel to %s",
    605 	    compress ? "compressed " : "", path);
    606 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
    607 		if (compress)
    608 			nw = fwrite(buf, 1, nr, fp);
    609 		else
    610 			nw = write(ofd, buf, nr);
    611 		if (nw != nr) {
    612 			syslog(LOG_ERR, "%s: %s",
    613 			    path, strerror(nw == 0 ? EIO : errno));
    614 			syslog(LOG_WARNING,
    615 			    "WARNING: kernel may be incomplete");
    616 			exit(1);
    617 		}
    618 	}
    619 	if (nr < 0) {
    620 		syslog(LOG_ERR, "%s: %m", kernel);
    621 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
    622 		exit(1);
    623 	}
    624 	if (compress)
    625 		(void)fclose(fp);
    626 	else
    627 		(void)close(ofd);
    628 }
    629 
    630 char *
    631 find_dev(dev_t dev, int type)
    632 {
    633 	DIR *dfd;
    634 	struct dirent *dir;
    635 	struct stat sb;
    636 	char *dp, device[MAXPATHLEN + 1], *p;
    637 	size_t l;
    638 
    639 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
    640 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
    641 		exit(1);
    642 	}
    643 	strlcpy(device, _PATH_DEV, sizeof(device));
    644 	p = &device[strlen(device)];
    645 	l = sizeof(device) - strlen(device);
    646 	while ((dir = readdir(dfd))) {
    647 		strlcpy(p, dir->d_name, l);
    648 		if (lstat(device, &sb)) {
    649 			syslog(LOG_ERR, "%s: %m", device);
    650 			continue;
    651 		}
    652 		if ((sb.st_mode & S_IFMT) != type)
    653 			continue;
    654 		if (dev == sb.st_rdev) {
    655 			closedir(dfd);
    656 			if ((dp = strdup(device)) == NULL) {
    657 				syslog(LOG_ERR, "%m");
    658 				exit(1);
    659 			}
    660 			return (dp);
    661 		}
    662 	}
    663 	closedir(dfd);
    664 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
    665 	exit(1);
    666 }
    667 
    668 char *
    669 rawname(char *s)
    670 {
    671 	char *sl;
    672 	char name[MAXPATHLEN];
    673 
    674 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
    675 		syslog(LOG_ERR,
    676 		    "can't make raw dump device name from %s", s);
    677 		return (s);
    678 	}
    679 	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
    680 	    sl + 1);
    681 	if ((sl = strdup(name)) == NULL) {
    682 		syslog(LOG_ERR, "%m");
    683 		exit(1);
    684 	}
    685 	return (sl);
    686 }
    687 
    688 int
    689 get_crashtime(void)
    690 {
    691 	time_t dumptime;			/* Time the dump was taken. */
    692 	struct timeval dtime;
    693 
    694 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
    695 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
    696 			if (verbose)
    697 				syslog(LOG_WARNING, "kvm_read: %s (and _time_seconf is not defined also)", kvm_geterr(kd_dump));
    698 			return (0);
    699 		}
    700 		dumptime = dtime.tv_sec;
    701 	}
    702 	if (dumptime == 0) {
    703 		if (verbose)
    704 			syslog(LOG_ERR, "dump time is zero");
    705 		return (0);
    706 	}
    707 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
    708 #define	LEEWAY	(60 * SECSPERDAY)
    709 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
    710 		(void)printf("dump time is unreasonable\n");
    711 		return (0);
    712 	}
    713 	return (1);
    714 }
    715 
    716 int
    717 check_space(void)
    718 {
    719 	FILE *fp;
    720 	off_t minfree, spacefree, kernelsize, needed;
    721 	struct stat st;
    722 	struct statvfs fsbuf;
    723 	char mbuf[100], path[MAXPATHLEN];
    724 
    725 #ifdef __GNUC__
    726 	(void) &minfree;
    727 #endif
    728 
    729 	if (stat(kernel, &st) < 0) {
    730 		syslog(LOG_ERR, "%s: %m", kernel);
    731 		exit(1);
    732 	}
    733 	kernelsize = st.st_blocks * S_BLKSIZE;
    734 	if (statvfs(dirname, &fsbuf) < 0) {
    735 		syslog(LOG_ERR, "%s: %m", dirname);
    736 		exit(1);
    737 	}
    738 	spacefree = fsbuf.f_bavail;
    739 	spacefree *= fsbuf.f_frsize;
    740 	spacefree /= 1024;
    741 
    742 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
    743 	if ((fp = fopen(path, "r")) == NULL)
    744 		minfree = 0;
    745 	else {
    746 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
    747 			minfree = 0;
    748 		else
    749 			minfree = atoi(mbuf);
    750 		(void)fclose(fp);
    751 	}
    752 
    753 	needed = (dumpbytes + kernelsize) / 1024;
    754  	if (minfree > 0 && spacefree - needed < minfree) {
    755 		syslog(LOG_WARNING,
    756 		    "no dump, not enough free space in %s", dirname);
    757 		return (0);
    758 	}
    759 	if (spacefree - needed < minfree)
    760 		syslog(LOG_WARNING,
    761 		    "dump performed, but free space threshold crossed");
    762 	return (1);
    763 }
    764 
    765 int
    766 Open(const char *name, int rw)
    767 {
    768 	int fd;
    769 
    770 	if ((fd = open(name, rw, 0)) < 0) {
    771 		syslog(LOG_ERR, "%s: %m", name);
    772 		exit(1);
    773 	}
    774 	return (fd);
    775 }
    776 
    777 void
    778 Lseek(int fd, off_t off, int flag)
    779 {
    780 	off_t ret;
    781 
    782 	ret = lseek(fd, off, flag);
    783 	if (ret == -1) {
    784 		syslog(LOG_ERR, "lseek: %m");
    785 		exit(1);
    786 	}
    787 }
    788 
    789 int
    790 Create(char *file, int mode)
    791 {
    792 	int fd;
    793 
    794 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
    795 	if (fd < 0) {
    796 		syslog(LOG_ERR, "%s: %m", file);
    797 		exit(1);
    798 	}
    799 	return (fd);
    800 }
    801 
    802 void
    803 Write(int fd, void *bp, int size)
    804 {
    805 	int n;
    806 
    807 	if ((n = write(fd, bp, size)) < size) {
    808 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
    809 		exit(1);
    810 	}
    811 }
    812 
    813 void
    814 usage(void)
    815 {
    816 	(void)syslog(LOG_ERR,
    817 	    "usage: savecore [-cfnvz] [-N system] [-Z level] directory");
    818 	exit(1);
    819 }
    820