xref: /netbsd-src/sbin/savecore/savecore.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: savecore.c,v 1.86 2013/05/13 18:44:11 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\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41 #else
42 __RCSID("$NetBSD: savecore.c,v 1.86 2013/05/13 18:44:11 christos Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #define _KSYMS_PRIVATE
47 
48 #include <stdbool.h>
49 
50 #include <sys/param.h>
51 #include <sys/mount.h>
52 #include <sys/msgbuf.h>
53 #include <sys/syslog.h>
54 #include <sys/time.h>
55 #include <sys/ksyms.h>
56 
57 #include <dirent.h>
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <nlist.h>
61 #include <paths.h>
62 #include <stddef.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <time.h>
67 #include <tzfile.h>
68 #include <unistd.h>
69 #include <util.h>
70 #include <limits.h>
71 #include <stdarg.h>
72 #include <kvm.h>
73 
74 extern FILE *zopen(const char *fname, const char *mode);
75 
76 #define	KREAD(kd, addr, p)\
77 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
78 
79 static struct nlist current_nl[] = {	/* Namelist for currently running system. */
80 #define	X_DUMPDEV	0
81 	{ .n_name = "_dumpdev" },
82 #define	X_DUMPLO	1
83 	{ .n_name = "_dumplo" },
84 #define	X_TIME_SECOND	2
85 	{ .n_name = "_time_second" },
86 #define X_TIME		3
87 	{ .n_name = "_time" },
88 #define	X_DUMPSIZE	4
89 	{ .n_name = "_dumpsize" },
90 #define	X_VERSION	5
91 	{ .n_name = "_version" },
92 #define	X_DUMPMAG	6
93 	{ .n_name = "_dumpmag" },
94 #define	X_PANICSTR	7
95 	{ .n_name = "_panicstr" },
96 #define	X_PANICSTART	8
97 	{ .n_name = "_panicstart" },
98 #define	X_PANICEND	9
99 	{ .n_name = "_panicend" },
100 #define	X_MSGBUF	10
101 	{ .n_name = "_msgbufp" },
102 #define	X_DUMPCDEV	11
103 	{ .n_name = "_dumpcdev" },
104 #define X_SYMSZ		12
105 	{ .n_name = "_ksyms_symsz" },
106 #define X_STRSZ		13
107 	{ .n_name = "_ksyms_strsz" },
108 #define X_KHDR		14
109 	{ .n_name = "_ksyms_hdr" },
110 #define X_SYMTABS	15
111 	{ .n_name = "_ksyms_symtabs" },
112 	{ .n_name = NULL },
113 };
114 static int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, X_DUMPCDEV, -1 };
115 static int dumpsyms[] = { X_TIME_SECOND, X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR,
116     X_DUMPMAG, X_SYMSZ, X_STRSZ, X_KHDR, X_SYMTABS, -1 };
117 
118 static struct nlist dump_nl[] = {	/* Name list for dumped system. */
119 	{ .n_name = "_dumpdev" },	/* Entries MUST be the same as */
120 	{ .n_name = "_dumplo" },	/*	those in current_nl[].  */
121 	{ .n_name = "_time_second" },
122 	{ .n_name = "_time" },
123 	{ .n_name = "_dumpsize" },
124 	{ .n_name = "_version" },
125 	{ .n_name = "_dumpmag" },
126 	{ .n_name = "_panicstr" },
127 	{ .n_name = "_panicstart" },
128 	{ .n_name = "_panicend" },
129 	{ .n_name = "_msgbufp" },
130 	{ .n_name = "_dumpcdev" },
131 	{ .n_name = "_ksyms_symsz" },
132 	{ .n_name = "_ksyms_strsz" },
133 	{ .n_name = "_ksyms_hdr" },
134 	{ .n_name = "_ksyms_symtabs" },
135 	{ .n_name = NULL },
136 };
137 
138 /* Types match kernel declarations. */
139 static off_t	dumplo;				/* where dump starts on dumpdev */
140 static u_int32_t dumpmag;			/* magic number in dump */
141 static int	dumpsize;			/* amount of memory dumped */
142 static off_t dumpbytes;			/* in bytes */
143 
144 static const char	*kernel;		/* name of used kernel */
145 static const char	*dirname;		/* directory to save dumps in */
146 static char	*ddname;			/* name of dump device */
147 static dev_t	dumpdev;			/* dump device */
148 static dev_t	dumpcdev = NODEV;		/* dump device (char equivalent) */
149 static int	dumpfd;				/* read/write descriptor on dev */
150 static kvm_t	*kd_dump;			/* kvm descriptor on dev	*/
151 static time_t	now;				/* current date */
152 static char	panic_mesg[1024];
153 static long	panicstr;
154 static char	vers[1024];
155 static char	gzmode[3];
156 
157 static void	check_kmem(void);
158 static int	check_space(void);
159 static void	clear_dump(void);
160 static int	Create(char *, int);
161 static int	dump_exists(int);
162 static char	*find_dev(dev_t, mode_t);
163 static int	get_crashtime(void);
164 static void	kmem_setup(int);
165 static void	Lseek(int, off_t, int);
166 static int	Open(const char *, int rw);
167 static void	save_core(int);
168 __dead static void	usage(const char *fmt, ...) __printflike(1, 2);
169 
170 int
171 main(int argc, char *argv[])
172 {
173 	int ch, level, testonly, compress, force, clear, verbose;
174 	char *ep;
175 
176 	kernel = NULL;
177 	level = 1;		/* default to fastest gzip compression */
178 	force = 0;
179 	clear = 0;
180 	testonly = 0;
181 	verbose = 0;
182 	compress = 0;
183 	gzmode[0] = 'w';
184 
185 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
186 
187 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
188 		switch(ch) {
189 		case 'c':
190 			clear = 1;
191 			break;
192 		case 'd':		/* Not documented. */
193 		case 'v':
194 			verbose = 1;
195 			break;
196 		case 'f':
197 			force = 1;
198 			break;
199 		case 'n':
200 			testonly = 1;
201 			break;
202 		case 'N':
203 			kernel = optarg;
204 			break;
205 		case 'z':
206 			compress = 1;
207 			break;
208 		case 'Z':
209 			level = (int)strtol(optarg, &ep, 10);
210 			if (level < 0 || level > 9)
211 				usage("Invalid compression `%s'", optarg);
212 			break;
213 		case '?':
214 			usage("Missing argument for flag `%c'", optopt);
215 		default:
216 			usage("Unknown flag `%c'", ch);
217 		}
218 	argc -= optind;
219 	argv += optind;
220 
221 	if (argc != 0)
222 		dirname = argv[0];
223 	else
224 		dirname = "/var/crash";
225 
226 	gzmode[1] = level + '0';
227 
228 	(void)time(&now);
229 	kmem_setup(verbose);
230 
231 	if (clear && !testonly) {
232 		clear_dump();
233 		exit(0);
234 	}
235 
236 	if (!dump_exists(verbose) && !force)
237 		exit(1);
238 
239 	if (testonly)
240 		/* If -n was passed and there was a dump, exit at level 0 */
241 		exit(0);
242 
243 	check_kmem();
244 
245 	if (panicstr)
246 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
247 	else
248 		syslog(LOG_ALERT, "reboot");
249 
250 	if ((!get_crashtime() || !check_space()) && !force)
251 		exit(1);
252 
253 	save_core(compress);
254 
255 	clear_dump();
256 	exit(0);
257 }
258 
259 static void
260 kmem_setup(int verbose)
261 {
262 	kvm_t *kd_kern;
263 	char errbuf[_POSIX2_LINE_MAX];
264 	int i, hdrsz;
265 
266 	/*
267 	 * Some names we need for the currently running system, others for
268 	 * the system that was running when the dump was made.  The values
269 	 * obtained from the current system are used to look for things in
270 	 * /dev/kmem that cannot be found in the kernel namelist, but are
271 	 * presumed to be the same (since the disk partitions are probably
272 	 * the same!)
273 	 */
274 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
275 	if (kd_kern == NULL) {
276 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
277 		exit(1);
278 	}
279 	if (kvm_nlist(kd_kern, current_nl) == -1)
280 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
281 		    kvm_geterr(kd_kern));
282 
283 	for (i = 0; cursyms[i] != -1; i++) {
284 		if (current_nl[cursyms[i]].n_value != 0)
285 			continue;
286 		switch (cursyms[i]) {
287 		case X_TIME_SECOND:
288 		case X_TIME:
289 		case X_DUMPCDEV:
290 			break;
291 		default:
292 			syslog(LOG_ERR, "%s: %s not in namelist",
293 			    kernel, current_nl[cursyms[i]].n_name);
294 			exit(1);
295 		}
296 	}
297 
298 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
299 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
300 		exit(1);
301 	}
302 	if (dumpdev == NODEV) {
303 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
304 		exit(1);
305 	}
306 	{
307 	    long l_dumplo;
308 
309 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
310 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
311 		    exit(1);
312 	    }
313 	    if (l_dumplo == -1) {
314 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
315 		exit(1);
316 	    }
317 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
318 	}
319 
320 	if (verbose)
321 		(void)printf("dumplo = %lld (%ld * %ld)\n",
322 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
323 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
324 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
325 		exit(1);
326 	}
327 
328 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
329 	    sizeof(vers));
330 	vers[sizeof(vers) - 1] = '\0';
331 
332 	if (current_nl[X_DUMPCDEV].n_value != 0) {
333 		if (KREAD(kd_kern, current_nl[X_DUMPCDEV].n_value,
334 		    &dumpcdev) != 0) {
335 			syslog(LOG_WARNING, "kvm_read: %s",
336 			    kvm_geterr(kd_kern));
337 			exit(1);
338 		}
339 		ddname = find_dev(dumpcdev, S_IFCHR);
340 	} else
341 		ddname = find_dev(dumpdev, S_IFBLK);
342 	if (strncmp(ddname, "/dev/cons", 8) == 0 ||
343 	    strncmp(ddname, "/dev/tty", 7) == 0 ||
344 	    strncmp(ddname, "/dev/pty", 7) == 0 ||
345 	    strncmp(ddname, "/dev/pts", 7) == 0) {
346 		syslog(LOG_ERR, "dumpdev %s is tty; override kernel", ddname);
347 		exit(1);
348 	}
349 	dumpfd = Open(ddname, O_RDWR);
350 
351 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
352 	if (kd_dump == NULL) {
353 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
354 		exit(1);
355 	}
356 
357 	if (kvm_nlist(kd_dump, dump_nl) == -1)
358 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
359 		    kvm_geterr(kd_dump));
360 
361 	for (i = 0; dumpsyms[i] != -1; i++)
362 		if (dump_nl[dumpsyms[i]].n_value == 0 &&
363 			dumpsyms[i] != X_TIME_SECOND &&
364 			dumpsyms[i] != X_TIME) {
365 			syslog(LOG_ERR, "%s: %s not in namelist",
366 			    kernel, dump_nl[dumpsyms[i]].n_name);
367 			exit(1);
368 		}
369 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
370 
371 	/*
372 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
373 	 * checks, ergo no dump is present...
374 	 */
375 	if (hdrsz == 0) {
376 		syslog(LOG_WARNING, "no core dump");
377 		exit(1);
378 	}
379 	if (hdrsz == -1) {
380 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
381 		    kvm_geterr(kd_dump));
382 		exit(1);
383 	}
384 	dumplo += hdrsz;
385 	kvm_close(kd_kern);
386 }
387 
388 static void
389 check_kmem(void)
390 {
391 	char *cp, *bufdata;
392 	struct kern_msgbuf msgbuf, *bufp;
393 	long panicloc, panicstart, panicend;
394 	char core_vers[1024];
395 
396 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
397 	    sizeof(core_vers));
398 	core_vers[sizeof(core_vers) - 1] = '\0';
399 
400 	if (strcmp(vers, core_vers) != 0)
401 		syslog(LOG_WARNING,
402 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
403 		    kvm_getkernelname(kd_dump), vers, core_vers);
404 
405 	panicstart = panicend = 0;
406 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
407 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
408 		goto nomsguf;
409 	}
410 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
411 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
412 		goto nomsguf;
413 	}
414 	if (panicstart != 0 && panicend != 0) {
415 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
416 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
417 			goto nomsguf;
418 		}
419 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
420 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
421 		    offsetof(struct kern_msgbuf, msg_bufc)) {
422 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
423 			goto nomsguf;
424 		}
425 		if (msgbuf.msg_magic != MSG_MAGIC) {
426 			syslog(LOG_WARNING, "msgbuf magic incorrect");
427 			goto nomsguf;
428 		}
429 		bufdata = malloc(msgbuf.msg_bufs);
430 		if (bufdata == NULL) {
431 			syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
432 			goto nomsguf;
433 		}
434 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
435 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
436 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
437 			free(bufdata);
438 			goto nomsguf;
439 		}
440 		cp = panic_mesg;
441 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
442 			*cp++ = bufdata[panicstart];
443 			panicstart++;
444 			if (panicstart >= msgbuf.msg_bufs)
445 				panicstart = 0;
446 		}
447 		/* Don't end in a new-line */
448 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
449 		if (*cp == '\n')
450 			*cp = '\0';
451 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
452 		free(bufdata);
453 
454 		panicstr = 1;	/* anything not zero */
455 		return;
456 	}
457 nomsguf:
458 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
459 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
460 		return;
461 	}
462 	if (panicstr) {
463 		cp = panic_mesg;
464 		panicloc = panicstr;
465 		do {
466 			if (KREAD(kd_dump, panicloc, cp) != 0) {
467 				syslog(LOG_WARNING, "kvm_read: %s",
468 				    kvm_geterr(kd_dump));
469 				break;
470 			}
471 			panicloc++;
472 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
473 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
474 	}
475 }
476 
477 static int
478 dump_exists(int verbose)
479 {
480 	u_int32_t newdumpmag;
481 
482 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
483 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
484 		return (0);
485 	}
486 
487 	/* Read the dump size. */
488 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
489 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
490 		return (0);
491 	}
492 	dumpbytes = (off_t)dumpsize * getpagesize();
493 
494 	/*
495 	 * Return zero if core dump doesn't seem to be there, and note
496 	 * it for syslog.  This check and return happens after the dump size
497 	 * is read, so dumpsize is whether or not the core is valid (for -f).
498 	 */
499 	if (newdumpmag != dumpmag) {
500 		if (verbose)
501 			syslog(LOG_WARNING, "magic number mismatch "
502 			    "(0x%x != 0x%x)", newdumpmag, dumpmag);
503 		syslog(LOG_WARNING, "no core dump");
504 		return (0);
505 	}
506 	return (1);
507 }
508 
509 static void
510 clear_dump(void)
511 {
512 	if (kvm_dump_inval(kd_dump) == -1)
513 		syslog(LOG_ERR, "%s: kvm_dump_inval: %s", ddname,
514 		    kvm_geterr(kd_dump));
515 
516 }
517 
518 static char buf[1024 * 1024];
519 
520 static void
521 save_kernel(FILE *fp, char *path)
522 {
523 	int nw, nr, ifd;
524 
525 	ifd = Open(kernel, O_RDONLY);
526 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
527 		nw = fwrite(buf, 1, nr, fp);
528 		if (nw != nr) {
529 			syslog(LOG_ERR, "%s: %s",
530 			    path, strerror(nw == 0 ? EIO : errno));
531 			syslog(LOG_WARNING,
532 			    "WARNING: kernel may be incomplete");
533 			exit(1);
534 		}
535 	}
536 	if (nr < 0) {
537 		syslog(LOG_ERR, "%s: %m", kernel);
538 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
539 		exit(1);
540 	}
541 }
542 
543 static int
544 ksymsget(u_long addr, void *ptr, size_t size)
545 {
546 
547 	if ((size_t)kvm_read(kd_dump, addr, ptr, size) != size) {
548 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
549 		return 1;
550 	}
551 	return 0;
552 }
553 
554 static int
555 save_ksyms(FILE *fp, char *path)
556 {
557 	struct ksyms_hdr khdr;
558 	int nw, symsz, strsz;
559 	TAILQ_HEAD(, ksyms_symtab) symtabs;
560 	struct ksyms_symtab st, *stptr;
561 	void *p;
562 
563 	/* Get basic info and ELF headers, check if ksyms was on. */
564 	if (ksymsget(dump_nl[X_KHDR].n_value, &khdr, sizeof(khdr)))
565 		return 1;
566 	if (ksymsget(dump_nl[X_SYMSZ].n_value, &symsz, sizeof(symsz)))
567 		return 1;
568 	if (ksymsget(dump_nl[X_STRSZ].n_value, &strsz, sizeof(strsz)))
569 		return 1;
570 	if (symsz == 0 || strsz == 0)
571 		return 1;
572 
573 	/* Update the ELF section headers for symbols/strings. */
574 	khdr.kh_shdr[SYMTAB].sh_size = symsz;
575 	khdr.kh_shdr[SYMTAB].sh_info = symsz / sizeof(Elf_Sym);
576 	khdr.kh_shdr[STRTAB].sh_offset = symsz +
577 	    khdr.kh_shdr[SYMTAB].sh_offset;
578 	khdr.kh_shdr[STRTAB].sh_size = strsz;
579 
580 	/* Write out the ELF headers. */
581 	nw = fwrite(&khdr, 1, sizeof(khdr), fp);
582 	if (nw != sizeof(khdr)) {
583 		syslog(LOG_ERR, "%s: %s",
584 		    path, strerror(nw == 0 ? EIO : errno));
585 		syslog(LOG_WARNING,
586 		    "WARNING: kernel may be incomplete");
587 		exit(1);
588         }
589 
590         /* Dump symbol table. */
591 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
592 		return 1;
593 	stptr = TAILQ_FIRST(&symtabs);
594 	while (stptr != NULL) {
595 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
596 			return 1;
597 		stptr = TAILQ_NEXT(&st, sd_queue);
598 		if ((p = malloc(st.sd_symsize)) == NULL)
599 			return 1;
600 		if (ksymsget((u_long)st.sd_symstart, p, st.sd_symsize)) {
601 			free(p);
602 			return 1;
603 		}
604 		nw = fwrite(p, 1, st.sd_symsize, fp);
605 		free(p);
606 		if (nw != st.sd_symsize) {
607 			syslog(LOG_ERR, "%s: %s",
608 			    path, strerror(nw == 0 ? EIO : errno));
609 			syslog(LOG_WARNING,
610 			    "WARNING: kernel may be incomplete");
611 			exit(1);
612 		}
613 	}
614 
615 	/* Dump string table. */
616 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
617 		return 1;
618 	stptr = TAILQ_FIRST(&symtabs);
619 	while (stptr != NULL) {
620 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
621 			return 1;
622 		stptr = TAILQ_NEXT(&st, sd_queue);
623 		if ((p = malloc(st.sd_symsize)) == NULL)
624 			return 1;
625 		if (ksymsget((u_long)st.sd_strstart, p, st.sd_strsize)) {
626 			free(p);
627 			return 1;
628 		}
629 		nw = fwrite(p, 1, st.sd_strsize, fp);
630 		free(p);
631 		if (nw != st.sd_strsize) {
632 			syslog(LOG_ERR, "%s: %s",
633 			    path, strerror(nw == 0 ? EIO : errno));
634 			syslog(LOG_WARNING,
635 			    "WARNING: kernel may be incomplete");
636 			exit(1);
637 		}
638 	}
639 
640 	return 0;
641 }
642 
643 static void
644 save_core(int compress)
645 {
646 	FILE *fp;
647 	int bounds, ifd, nr, nw, ofd, tryksyms;
648 	char path[MAXPATHLEN], rbuf[MAXPATHLEN];
649 	const char *rawp;
650 
651 	ofd = -1;
652 	/*
653 	 * Get the current number and update the bounds file.  Do the update
654 	 * now, because may fail later and don't want to overwrite anything.
655 	 */
656 	umask(066);
657 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
658 	if ((fp = fopen(path, "r")) == NULL)
659 		goto err1;
660 	if (fgets(buf, sizeof(buf), fp) == NULL) {
661 		if (ferror(fp))
662 err1:			syslog(LOG_WARNING, "%s: %m", path);
663 		bounds = 0;
664 	} else
665 		bounds = atoi(buf);
666 	if (fp != NULL)
667 		(void)fclose(fp);
668 	if ((fp = fopen(path, "w")) == NULL)
669 		syslog(LOG_ERR, "%s: %m", path);
670 	else {
671 		(void)fprintf(fp, "%d\n", bounds + 1);
672 		(void)fclose(fp);
673 	}
674 
675 	/* Create the core file. */
676 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
677 	    dirname, bounds, compress ? ".gz" : "");
678 	if (compress) {
679 		if ((fp = zopen(path, gzmode)) == NULL) {
680 			syslog(LOG_ERR, "%s: %m", path);
681 			exit(1);
682 		}
683 	} else {
684 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
685 		fp  = fdopen(ofd, "w");
686 		if (fp == NULL) {
687 			syslog(LOG_ERR, "%s: fdopen: %m", path);
688 			exit(1);
689 		}
690 	}
691 
692 	if (dumpcdev == NODEV) {
693 		/* Open the raw device. */
694 		rawp = getdiskrawname(rbuf, sizeof(rbuf), ddname);
695 		if (rawp == NULL) {
696 			syslog(LOG_WARNING, "%s: %m; can't convert to raw",
697 			    ddname);
698 			rawp = ddname;
699 		}
700 		if ((ifd = open(rawp, O_RDONLY)) == -1) {
701 			syslog(LOG_WARNING, "%s: %m; using block device",
702 			    rawp);
703 			ifd = dumpfd;
704 		}
705 	} else {
706 		rawp = ddname;
707 		ifd = dumpfd;
708 	}
709 
710 	/* Seek to the start of the core. */
711 	Lseek(ifd, dumplo, SEEK_SET);
712 
713 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
714 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
715 		    kvm_geterr(kd_dump));
716 		exit(1);
717 	}
718 
719 	/* Copy the core file. */
720 	syslog(LOG_NOTICE, "writing %score to %s",
721 	    compress ? "compressed " : "", path);
722 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
723 		char nbuf[7];
724 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
725 		(void)printf("%7s\r", nbuf);
726 		(void)fflush(stdout);
727 		nr = read(ifd, buf, MIN(dumpbytes, (off_t)sizeof(buf)));
728 		if (nr <= 0) {
729 			if (nr == 0)
730 				syslog(LOG_WARNING,
731 				    "WARNING: EOF on dump device");
732 			else
733 				syslog(LOG_ERR, "%s: %m", rawp);
734 			goto err2;
735 		}
736 		nw = fwrite(buf, 1, nr, fp);
737 		if (nw != nr) {
738 			syslog(LOG_ERR, "%s: %s",
739 			    path, strerror(nw == 0 ? EIO : errno));
740 err2:			syslog(LOG_WARNING,
741 			    "WARNING: core may be incomplete");
742 			(void)printf("\n");
743 			exit(1);
744 		}
745 	}
746 	if (dumpcdev == NODEV)
747 		(void)close(ifd);
748 	(void)fclose(fp);
749 
750 	/* Create a kernel. */
751 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
752 	    dirname, bounds, compress ? ".gz" : "");
753 	syslog(LOG_NOTICE, "writing %skernel to %s",
754 	    compress ? "compressed " : "", path);
755 	for (tryksyms = 1;; tryksyms = 0) {
756 		if (compress) {
757 			if ((fp = zopen(path, gzmode)) == NULL) {
758 				syslog(LOG_ERR, "%s: %m", path);
759 				exit(1);
760 			}
761 		} else {
762 			ofd = Create(path, S_IRUSR | S_IWUSR);
763 			fp  = fdopen(ofd, "w");
764 			if (fp == NULL) {
765 				syslog(LOG_ERR, "fdopen: %m");
766 				exit(1);
767 			}
768 		}
769 		if (tryksyms) {
770 			if (!save_ksyms(fp, path))
771 				break;
772 			(void)fclose(fp);
773 			unlink(path);
774 		} else {
775 			save_kernel(fp, path);
776 			break;
777 		}
778 	}
779 	(void)fclose(fp);
780 
781 	/*
782 	 * For development systems where the crash occurs during boot
783 	 * to multiuser.
784 	 */
785 	sync();
786 	sleep(1);
787 	sync();
788 	sleep(1);
789 }
790 
791 static char *
792 find_dev(dev_t dev, mode_t type)
793 {
794 	DIR *dfd;
795 	struct dirent *dir;
796 	struct stat sb;
797 	char *dp, device[MAXPATHLEN + 1], *p;
798 	size_t l;
799 
800 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
801 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
802 		exit(1);
803 	}
804 	strlcpy(device, _PATH_DEV, sizeof(device));
805 	p = &device[strlen(device)];
806 	l = sizeof(device) - strlen(device);
807 	while ((dir = readdir(dfd))) {
808 		strlcpy(p, dir->d_name, l);
809 		if (lstat(device, &sb)) {
810 			syslog(LOG_ERR, "%s: %m", device);
811 			continue;
812 		}
813 		if ((sb.st_mode & S_IFMT) != type)
814 			continue;
815 		if (dev == sb.st_rdev) {
816 			closedir(dfd);
817 			if ((dp = strdup(device)) == NULL) {
818 				syslog(LOG_ERR, "%m");
819 				exit(1);
820 			}
821 			return (dp);
822 		}
823 	}
824 	closedir(dfd);
825 	syslog(LOG_ERR, "can't find device %lld/%lld",
826 	    (long long)major(dev), (long long)minor(dev));
827 	exit(1);
828 }
829 
830 static int
831 get_crashtime(void)
832 {
833 	time_t dumptime;			/* Time the dump was taken. */
834 	struct timeval dtime;
835 
836 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
837 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
838 			syslog(LOG_WARNING, "kvm_read: %s (and _time_second "
839 			    "is not defined also)", kvm_geterr(kd_dump));
840 			return (0);
841 		}
842 		dumptime = dtime.tv_sec;
843 	}
844 	if (dumptime == 0) {
845 		syslog(LOG_WARNING, "dump time is zero");
846 		return (0);
847 	}
848 	syslog(LOG_INFO, "system went down at %s", ctime(&dumptime));
849 #define	LEEWAY	(60 * SECSPERDAY)
850 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
851 		syslog(LOG_WARNING, "dump time is unreasonable");
852 		return (0);
853 	}
854 	return (1);
855 }
856 
857 static int
858 check_space(void)
859 {
860 	FILE *fp;
861 	off_t minfree, spacefree, kernelsize, needed;
862 	struct stat st;
863 	struct statvfs fsbuf;
864 	char mbuf[100], path[MAXPATHLEN];
865 
866 	/* XXX assume a reasonable default, unless we find a kernel. */
867 	kernelsize = 20 * 1024 * 1024;
868 	if (!stat(kernel, &st)) kernelsize = st.st_blocks * S_BLKSIZE;
869 	if (statvfs(dirname, &fsbuf) < 0) {
870 		syslog(LOG_ERR, "%s: %m", dirname);
871 		exit(1);
872 	}
873 	spacefree = fsbuf.f_bavail;
874 	spacefree *= fsbuf.f_frsize;
875 	spacefree /= 1024;
876 
877 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
878 	if ((fp = fopen(path, "r")) == NULL)
879 		minfree = 0;
880 	else {
881 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
882 			minfree = 0;
883 		else
884 			minfree = atoi(mbuf);
885 		(void)fclose(fp);
886 	}
887 
888 	needed = (dumpbytes + kernelsize) / 1024;
889  	if (minfree > 0 && spacefree - needed < minfree) {
890 		syslog(LOG_WARNING,
891 		    "no dump, not enough free space in %s", dirname);
892 		return (0);
893 	}
894 	if (spacefree - needed < minfree)
895 		syslog(LOG_WARNING,
896 		    "dump performed, but free space threshold crossed");
897 	return (1);
898 }
899 
900 static int
901 Open(const char *name, int rw)
902 {
903 	int fd;
904 
905 	if ((fd = open(name, rw, 0)) < 0) {
906 		syslog(LOG_ERR, "%s: %m", name);
907 		exit(1);
908 	}
909 	return (fd);
910 }
911 
912 static void
913 Lseek(int fd, off_t off, int flag)
914 {
915 	off_t ret;
916 
917 	ret = lseek(fd, off, flag);
918 	if (ret == -1) {
919 		syslog(LOG_ERR, "lseek: %m");
920 		exit(1);
921 	}
922 }
923 
924 static int
925 Create(char *file, int mode)
926 {
927 	int fd;
928 
929 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
930 	if (fd < 0) {
931 		syslog(LOG_ERR, "%s: %m", file);
932 		exit(1);
933 	}
934 	return (fd);
935 }
936 
937 static void
938 usage(const char *fmt, ...)
939 {
940 	va_list ap;
941 	va_start(ap, fmt);
942 	(void)vsyslog(LOG_ERR, fmt, ap);
943 	va_end(ap);
944 	(void)syslog(LOG_ERR,
945 	    "Usage: %s [-cfnvz] [-N system] [-Z level] [directory]",
946 	    getprogname());
947 	exit(1);
948 }
949