xref: /netbsd-src/sbin/savecore/savecore.c (revision a4ddc2c8fb9af816efe3b1c375a5530aef0e89e9)
1 /*	$NetBSD: savecore.c,v 1.85 2012/04/07 16:44:10 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 1.85 2012/04/07 16:44:10 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 int	clear, compress, force, verbose;	/* flags */
158 
159 static void	check_kmem(void);
160 static int	check_space(void);
161 static void	clear_dump(void);
162 static int	Create(char *, int);
163 static int	dump_exists(void);
164 static char	*find_dev(dev_t, mode_t);
165 static int	get_crashtime(void);
166 static void	kmem_setup(void);
167 static void	Lseek(int, off_t, int);
168 static int	Open(const char *, int rw);
169 static void	save_core(void);
170 __dead static void	usage(const char *fmt, ...) __printflike(1, 2);
171 
172 int
173 main(int argc, char *argv[])
174 {
175 	int ch, level, testonly;
176 	char *ep;
177 
178 	kernel = NULL;
179 	level = 1;		/* default to fastest gzip compression */
180 	testonly = 0;
181 	gzmode[0] = 'w';
182 
183 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
184 
185 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
186 		switch(ch) {
187 		case 'c':
188 			clear = 1;
189 			break;
190 		case 'd':		/* Not documented. */
191 		case 'v':
192 			verbose = 1;
193 			break;
194 		case 'f':
195 			force = 1;
196 			break;
197 		case 'n':
198 			testonly = 1;
199 			break;
200 		case 'N':
201 			kernel = optarg;
202 			break;
203 		case 'z':
204 			compress = 1;
205 			break;
206 		case 'Z':
207 			level = (int)strtol(optarg, &ep, 10);
208 			if (level < 0 || level > 9)
209 				usage("Invalid compression `%s'", optarg);
210 			break;
211 		case '?':
212 			usage("Missing argument for flag `%c'", optopt);
213 		default:
214 			usage("Unknown flag `%c'", ch);
215 		}
216 	argc -= optind;
217 	argv += optind;
218 
219 	if (argc != 0)
220 		dirname = argv[0];
221 	else
222 		dirname = "/var/crash";
223 
224 	gzmode[1] = level + '0';
225 
226 	(void)time(&now);
227 	kmem_setup();
228 
229 	if (clear && !testonly) {
230 		clear_dump();
231 		exit(0);
232 	}
233 
234 	if (!dump_exists() && !force)
235 		exit(1);
236 
237 	if (testonly)
238 		/* If -n was passed and there was a dump, exit at level 0 */
239 		exit(0);
240 
241 	check_kmem();
242 
243 	if (panicstr)
244 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
245 	else
246 		syslog(LOG_ALERT, "reboot");
247 
248 	if ((!get_crashtime() || !check_space()) && !force)
249 		exit(1);
250 
251 	save_core();
252 
253 	clear_dump();
254 	exit(0);
255 }
256 
257 static void
258 kmem_setup(void)
259 {
260 	kvm_t *kd_kern;
261 	char errbuf[_POSIX2_LINE_MAX];
262 	int i, hdrsz;
263 
264 	/*
265 	 * Some names we need for the currently running system, others for
266 	 * the system that was running when the dump was made.  The values
267 	 * obtained from the current system are used to look for things in
268 	 * /dev/kmem that cannot be found in the kernel namelist, but are
269 	 * presumed to be the same (since the disk partitions are probably
270 	 * the same!)
271 	 */
272 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
273 	if (kd_kern == NULL) {
274 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
275 		exit(1);
276 	}
277 	if (kvm_nlist(kd_kern, current_nl) == -1)
278 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
279 		    kvm_geterr(kd_kern));
280 
281 	for (i = 0; cursyms[i] != -1; i++) {
282 		if (current_nl[cursyms[i]].n_value != 0)
283 			continue;
284 		switch (cursyms[i]) {
285 		case X_TIME_SECOND:
286 		case X_TIME:
287 		case X_DUMPCDEV:
288 			break;
289 		default:
290 			syslog(LOG_ERR, "%s: %s not in namelist",
291 			    kernel, current_nl[cursyms[i]].n_name);
292 			exit(1);
293 		}
294 	}
295 
296 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
297 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
298 		exit(1);
299 	}
300 	if (dumpdev == NODEV) {
301 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
302 		exit(1);
303 	}
304 	{
305 	    long l_dumplo;
306 
307 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
308 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
309 		    exit(1);
310 	    }
311 	    if (l_dumplo == -1) {
312 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
313 		exit(1);
314 	    }
315 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
316 	}
317 
318 	if (verbose)
319 		(void)printf("dumplo = %lld (%ld * %ld)\n",
320 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
321 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
322 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
323 		exit(1);
324 	}
325 
326 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
327 	    sizeof(vers));
328 	vers[sizeof(vers) - 1] = '\0';
329 
330 	if (current_nl[X_DUMPCDEV].n_value != 0) {
331 		if (KREAD(kd_kern, current_nl[X_DUMPCDEV].n_value,
332 		    &dumpcdev) != 0) {
333 			syslog(LOG_WARNING, "kvm_read: %s",
334 			    kvm_geterr(kd_kern));
335 			exit(1);
336 		}
337 		ddname = find_dev(dumpcdev, S_IFCHR);
338 	} else
339 		ddname = find_dev(dumpdev, S_IFBLK);
340 	if (strncmp(ddname, "/dev/cons", 8) == 0 ||
341 	    strncmp(ddname, "/dev/tty", 7) == 0 ||
342 	    strncmp(ddname, "/dev/pty", 7) == 0 ||
343 	    strncmp(ddname, "/dev/pts", 7) == 0) {
344 		syslog(LOG_ERR, "dumpdev %s is tty; override kernel", ddname);
345 		exit(1);
346 	}
347 	dumpfd = Open(ddname, O_RDWR);
348 
349 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
350 	if (kd_dump == NULL) {
351 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
352 		exit(1);
353 	}
354 
355 	if (kvm_nlist(kd_dump, dump_nl) == -1)
356 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
357 		    kvm_geterr(kd_dump));
358 
359 	for (i = 0; dumpsyms[i] != -1; i++)
360 		if (dump_nl[dumpsyms[i]].n_value == 0 &&
361 			dumpsyms[i] != X_TIME_SECOND &&
362 			dumpsyms[i] != X_TIME) {
363 			syslog(LOG_ERR, "%s: %s not in namelist",
364 			    kernel, dump_nl[dumpsyms[i]].n_name);
365 			exit(1);
366 		}
367 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
368 
369 	/*
370 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
371 	 * checks, ergo no dump is present...
372 	 */
373 	if (hdrsz == 0) {
374 		syslog(LOG_WARNING, "no core dump");
375 		exit(1);
376 	}
377 	if (hdrsz == -1) {
378 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
379 		    kvm_geterr(kd_dump));
380 		exit(1);
381 	}
382 	dumplo += hdrsz;
383 	kvm_close(kd_kern);
384 }
385 
386 static void
387 check_kmem(void)
388 {
389 	char *cp, *bufdata;
390 	struct kern_msgbuf msgbuf, *bufp;
391 	long panicloc, panicstart, panicend;
392 	char core_vers[1024];
393 
394 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
395 	    sizeof(core_vers));
396 	core_vers[sizeof(core_vers) - 1] = '\0';
397 
398 	if (strcmp(vers, core_vers) != 0)
399 		syslog(LOG_WARNING,
400 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
401 		    kvm_getkernelname(kd_dump), vers, core_vers);
402 
403 	panicstart = panicend = 0;
404 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
405 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
406 		goto nomsguf;
407 	}
408 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
409 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
410 		goto nomsguf;
411 	}
412 	if (panicstart != 0 && panicend != 0) {
413 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
414 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
415 			goto nomsguf;
416 		}
417 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
418 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
419 		    offsetof(struct kern_msgbuf, msg_bufc)) {
420 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
421 			goto nomsguf;
422 		}
423 		if (msgbuf.msg_magic != MSG_MAGIC) {
424 			syslog(LOG_WARNING, "msgbuf magic incorrect");
425 			goto nomsguf;
426 		}
427 		bufdata = malloc(msgbuf.msg_bufs);
428 		if (bufdata == NULL) {
429 			syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
430 			goto nomsguf;
431 		}
432 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
433 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
434 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
435 			free(bufdata);
436 			goto nomsguf;
437 		}
438 		cp = panic_mesg;
439 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
440 			*cp++ = bufdata[panicstart];
441 			panicstart++;
442 			if (panicstart >= msgbuf.msg_bufs)
443 				panicstart = 0;
444 		}
445 		/* Don't end in a new-line */
446 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
447 		if (*cp == '\n')
448 			*cp = '\0';
449 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
450 		free(bufdata);
451 
452 		panicstr = 1;	/* anything not zero */
453 		return;
454 	}
455 nomsguf:
456 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
457 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
458 		return;
459 	}
460 	if (panicstr) {
461 		cp = panic_mesg;
462 		panicloc = panicstr;
463 		do {
464 			if (KREAD(kd_dump, panicloc, cp) != 0) {
465 				syslog(LOG_WARNING, "kvm_read: %s",
466 				    kvm_geterr(kd_dump));
467 				break;
468 			}
469 			panicloc++;
470 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
471 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
472 	}
473 }
474 
475 static int
476 dump_exists(void)
477 {
478 	u_int32_t newdumpmag;
479 
480 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
481 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
482 		return (0);
483 	}
484 
485 	/* Read the dump size. */
486 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
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, "magic number mismatch "
500 			    "(0x%x != 0x%x)", newdumpmag, dumpmag);
501 		syslog(LOG_WARNING, "no core dump");
502 		return (0);
503 	}
504 	return (1);
505 }
506 
507 static void
508 clear_dump(void)
509 {
510 	if (kvm_dump_inval(kd_dump) == -1)
511 		syslog(LOG_ERR, "%s: kvm_dump_inval: %s", ddname,
512 		    kvm_geterr(kd_dump));
513 
514 }
515 
516 static char buf[1024 * 1024];
517 
518 static void
519 save_kernel(int ofd, FILE *fp, char *path)
520 {
521 	int nw, nr, ifd;
522 
523 	ifd = Open(kernel, O_RDONLY);
524 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
525 		if (compress)
526 			nw = fwrite(buf, 1, nr, fp);
527 		else
528 			nw = write(ofd, buf, nr);
529 		if (nw != nr) {
530 			syslog(LOG_ERR, "%s: %s",
531 			    path, strerror(nw == 0 ? EIO : errno));
532 			syslog(LOG_WARNING,
533 			    "WARNING: kernel may be incomplete");
534 			exit(1);
535 		}
536 	}
537 	if (nr < 0) {
538 		syslog(LOG_ERR, "%s: %m", kernel);
539 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
540 		exit(1);
541 	}
542 }
543 
544 static int
545 ksymsget(u_long addr, void *ptr, size_t size)
546 {
547 
548 	if ((size_t)kvm_read(kd_dump, addr, ptr, size) != size) {
549 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
550 		return 1;
551 	}
552 	return 0;
553 }
554 
555 static int
556 save_ksyms(int ofd, FILE *fp, char *path)
557 {
558 	struct ksyms_hdr khdr;
559 	int nw, symsz, strsz;
560 	TAILQ_HEAD(, ksyms_symtab) symtabs;
561 	struct ksyms_symtab st, *stptr;
562 	void *p;
563 
564 	/* Get basic info and ELF headers, check if ksyms was on. */
565 	if (ksymsget(dump_nl[X_KHDR].n_value, &khdr, sizeof(khdr)))
566 		return 1;
567 	if (ksymsget(dump_nl[X_SYMSZ].n_value, &symsz, sizeof(symsz)))
568 		return 1;
569 	if (ksymsget(dump_nl[X_STRSZ].n_value, &strsz, sizeof(strsz)))
570 		return 1;
571 	if (symsz == 0 || strsz == 0)
572 		return 1;
573 
574 	/* Update the ELF section headers for symbols/strings. */
575 	khdr.kh_shdr[SYMTAB].sh_size = symsz;
576 	khdr.kh_shdr[SYMTAB].sh_info = symsz / sizeof(Elf_Sym);
577 	khdr.kh_shdr[STRTAB].sh_offset = symsz +
578 	    khdr.kh_shdr[SYMTAB].sh_offset;
579 	khdr.kh_shdr[STRTAB].sh_size = strsz;
580 
581 	/* Write out the ELF headers. */
582 	if (compress)
583 		nw = fwrite(&khdr, 1, sizeof(khdr), fp);
584 	else
585 		nw = write(ofd, &khdr, sizeof(khdr));
586 	if (nw != sizeof(khdr)) {
587 		syslog(LOG_ERR, "%s: %s",
588 		    path, strerror(nw == 0 ? EIO : errno));
589 		syslog(LOG_WARNING,
590 		    "WARNING: kernel may be incomplete");
591 		exit(1);
592         }
593 
594         /* Dump symbol table. */
595 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
596 		return 1;
597 	stptr = TAILQ_FIRST(&symtabs);
598 	while (stptr != NULL) {
599 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
600 			return 1;
601 		stptr = TAILQ_NEXT(&st, sd_queue);
602 		if ((p = malloc(st.sd_symsize)) == NULL)
603 			return 1;
604 		if (ksymsget((u_long)st.sd_symstart, p, st.sd_symsize)) {
605 			free(p);
606 			return 1;
607 		}
608 		if (compress)
609 			nw = fwrite(p, 1, st.sd_symsize, fp);
610 		else
611 			nw = write(ofd, p, st.sd_symsize);
612 		free(p);
613 		if (nw != st.sd_symsize) {
614 			syslog(LOG_ERR, "%s: %s",
615 			    path, strerror(nw == 0 ? EIO : errno));
616 			syslog(LOG_WARNING,
617 			    "WARNING: kernel may be incomplete");
618 			exit(1);
619 		}
620 	}
621 
622 	/* Dump string table. */
623 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
624 		return 1;
625 	stptr = TAILQ_FIRST(&symtabs);
626 	while (stptr != NULL) {
627 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
628 			return 1;
629 		stptr = TAILQ_NEXT(&st, sd_queue);
630 		if ((p = malloc(st.sd_symsize)) == NULL)
631 			return 1;
632 		if (ksymsget((u_long)st.sd_strstart, p, st.sd_strsize)) {
633 			free(p);
634 			return 1;
635 		}
636 		if (compress)
637 			nw = fwrite(p, 1, st.sd_strsize, fp);
638 		else
639 			nw = write(ofd, p, st.sd_strsize);
640 		free(p);
641 		if (nw != st.sd_strsize) {
642 			syslog(LOG_ERR, "%s: %s",
643 			    path, strerror(nw == 0 ? EIO : errno));
644 			syslog(LOG_WARNING,
645 			    "WARNING: kernel may be incomplete");
646 			exit(1);
647 		}
648 	}
649 
650 	return 0;
651 }
652 
653 static void
654 save_core(void)
655 {
656 	FILE *fp;
657 	int bounds, ifd, nr, nw, ofd, tryksyms;
658 	char path[MAXPATHLEN], rbuf[MAXPATHLEN];
659 	const char *rawp;
660 
661 	ofd = -1;
662 	/*
663 	 * Get the current number and update the bounds file.  Do the update
664 	 * now, because may fail later and don't want to overwrite anything.
665 	 */
666 	umask(066);
667 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
668 	if ((fp = fopen(path, "r")) == NULL)
669 		goto err1;
670 	if (fgets(buf, sizeof(buf), fp) == NULL) {
671 		if (ferror(fp))
672 err1:			syslog(LOG_WARNING, "%s: %m", path);
673 		bounds = 0;
674 	} else
675 		bounds = atoi(buf);
676 	if (fp != NULL)
677 		(void)fclose(fp);
678 	if ((fp = fopen(path, "w")) == NULL)
679 		syslog(LOG_ERR, "%s: %m", path);
680 	else {
681 		(void)fprintf(fp, "%d\n", bounds + 1);
682 		(void)fclose(fp);
683 	}
684 
685 	/* Create the core file. */
686 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
687 	    dirname, bounds, compress ? ".gz" : "");
688 	if (compress) {
689 		if ((fp = zopen(path, gzmode)) == NULL) {
690 			syslog(LOG_ERR, "%s: %m", path);
691 			exit(1);
692 		}
693 	} else {
694 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
695 		fp  = fdopen(ofd, "w");
696 		if (fp == NULL) {
697 			syslog(LOG_ERR, "%s: fdopen: %m", path);
698 			exit(1);
699 		}
700 	}
701 
702 	if (dumpcdev == NODEV) {
703 		/* Open the raw device. */
704 		rawp = getdiskrawname(rbuf, sizeof(rbuf), ddname);
705 		if (rawp == NULL) {
706 			syslog(LOG_WARNING, "%s: %m; can't convert to raw",
707 			    ddname);
708 			rawp = ddname;
709 		}
710 		if ((ifd = open(rawp, O_RDONLY)) == -1) {
711 			syslog(LOG_WARNING, "%s: %m; using block device",
712 			    rawp);
713 			ifd = dumpfd;
714 		}
715 	} else {
716 		rawp = ddname;
717 		ifd = dumpfd;
718 	}
719 
720 	/* Seek to the start of the core. */
721 	Lseek(ifd, dumplo, SEEK_SET);
722 
723 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
724 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
725 		    kvm_geterr(kd_dump));
726 		exit(1);
727 	}
728 
729 	/* Copy the core file. */
730 	syslog(LOG_NOTICE, "writing %score to %s",
731 	    compress ? "compressed " : "", path);
732 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
733 		char nbuf[7];
734 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
735 		(void)printf("%7s\r", nbuf);
736 		(void)fflush(stdout);
737 		nr = read(ifd, buf, MIN(dumpbytes, (off_t)sizeof(buf)));
738 		if (nr <= 0) {
739 			if (nr == 0)
740 				syslog(LOG_WARNING,
741 				    "WARNING: EOF on dump device");
742 			else
743 				syslog(LOG_ERR, "%s: %m", rawp);
744 			goto err2;
745 		}
746 		nw = fwrite(buf, 1, nr, fp);
747 		if (nw != nr) {
748 			syslog(LOG_ERR, "%s: %s",
749 			    path, strerror(nw == 0 ? EIO : errno));
750 err2:			syslog(LOG_WARNING,
751 			    "WARNING: core may be incomplete");
752 			(void)printf("\n");
753 			exit(1);
754 		}
755 	}
756 	if (dumpcdev == NODEV)
757 		(void)close(ifd);
758 	(void)fclose(fp);
759 
760 	/* Create a kernel. */
761 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
762 	    dirname, bounds, compress ? ".gz" : "");
763 	syslog(LOG_NOTICE, "writing %skernel to %s",
764 	    compress ? "compressed " : "", path);
765 	for (tryksyms = 1;; tryksyms = 0) {
766 		if (compress) {
767 			if ((fp = zopen(path, gzmode)) == NULL) {
768 				syslog(LOG_ERR, "%s: %m", path);
769 				exit(1);
770 			}
771 		} else
772 			ofd = Create(path, S_IRUSR | S_IWUSR);
773 		if (tryksyms) {
774 			if (!save_ksyms(ofd, fp, path))
775 				break;
776 			if (compress)
777 				(void)fclose(fp);
778 			else
779 				(void)close(ofd);
780 			unlink(path);
781 		} else {
782 			save_kernel(ofd, fp, path);
783 			break;
784 		}
785 	}
786 	if (compress)
787 		(void)fclose(fp);
788 	else
789 		(void)close(ofd);
790 
791 	/*
792 	 * For development systems where the crash occurs during boot
793 	 * to multiuser.
794 	 */
795 	sync();
796 	sleep(1);
797 	sync();
798 	sleep(1);
799 }
800 
801 static char *
802 find_dev(dev_t dev, mode_t type)
803 {
804 	DIR *dfd;
805 	struct dirent *dir;
806 	struct stat sb;
807 	char *dp, device[MAXPATHLEN + 1], *p;
808 	size_t l;
809 
810 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
811 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
812 		exit(1);
813 	}
814 	strlcpy(device, _PATH_DEV, sizeof(device));
815 	p = &device[strlen(device)];
816 	l = sizeof(device) - strlen(device);
817 	while ((dir = readdir(dfd))) {
818 		strlcpy(p, dir->d_name, l);
819 		if (lstat(device, &sb)) {
820 			syslog(LOG_ERR, "%s: %m", device);
821 			continue;
822 		}
823 		if ((sb.st_mode & S_IFMT) != type)
824 			continue;
825 		if (dev == sb.st_rdev) {
826 			closedir(dfd);
827 			if ((dp = strdup(device)) == NULL) {
828 				syslog(LOG_ERR, "%m");
829 				exit(1);
830 			}
831 			return (dp);
832 		}
833 	}
834 	closedir(dfd);
835 	syslog(LOG_ERR, "can't find device %lld/%lld",
836 	    (long long)major(dev), (long long)minor(dev));
837 	exit(1);
838 }
839 
840 static int
841 get_crashtime(void)
842 {
843 	time_t dumptime;			/* Time the dump was taken. */
844 	struct timeval dtime;
845 
846 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
847 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
848 			syslog(LOG_WARNING, "kvm_read: %s (and _time_second "
849 			    "is not defined also)", kvm_geterr(kd_dump));
850 			return (0);
851 		}
852 		dumptime = dtime.tv_sec;
853 	}
854 	if (dumptime == 0) {
855 		syslog(LOG_WARNING, "dump time is zero");
856 		return (0);
857 	}
858 	syslog(LOG_INFO, "system went down at %s", ctime(&dumptime));
859 #define	LEEWAY	(60 * SECSPERDAY)
860 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
861 		syslog(LOG_WARNING, "dump time is unreasonable");
862 		return (0);
863 	}
864 	return (1);
865 }
866 
867 static int
868 check_space(void)
869 {
870 	FILE *fp;
871 	off_t minfree, spacefree, kernelsize, needed;
872 	struct stat st;
873 	struct statvfs fsbuf;
874 	char mbuf[100], path[MAXPATHLEN];
875 
876 	/* XXX assume a reasonable default, unless we find a kernel. */
877 	kernelsize = 20 * 1024 * 1024;
878 	if (!stat(kernel, &st)) kernelsize = st.st_blocks * S_BLKSIZE;
879 	if (statvfs(dirname, &fsbuf) < 0) {
880 		syslog(LOG_ERR, "%s: %m", dirname);
881 		exit(1);
882 	}
883 	spacefree = fsbuf.f_bavail;
884 	spacefree *= fsbuf.f_frsize;
885 	spacefree /= 1024;
886 
887 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
888 	if ((fp = fopen(path, "r")) == NULL)
889 		minfree = 0;
890 	else {
891 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
892 			minfree = 0;
893 		else
894 			minfree = atoi(mbuf);
895 		(void)fclose(fp);
896 	}
897 
898 	needed = (dumpbytes + kernelsize) / 1024;
899  	if (minfree > 0 && spacefree - needed < minfree) {
900 		syslog(LOG_WARNING,
901 		    "no dump, not enough free space in %s", dirname);
902 		return (0);
903 	}
904 	if (spacefree - needed < minfree)
905 		syslog(LOG_WARNING,
906 		    "dump performed, but free space threshold crossed");
907 	return (1);
908 }
909 
910 static int
911 Open(const char *name, int rw)
912 {
913 	int fd;
914 
915 	if ((fd = open(name, rw, 0)) < 0) {
916 		syslog(LOG_ERR, "%s: %m", name);
917 		exit(1);
918 	}
919 	return (fd);
920 }
921 
922 static void
923 Lseek(int fd, off_t off, int flag)
924 {
925 	off_t ret;
926 
927 	ret = lseek(fd, off, flag);
928 	if (ret == -1) {
929 		syslog(LOG_ERR, "lseek: %m");
930 		exit(1);
931 	}
932 }
933 
934 static int
935 Create(char *file, int mode)
936 {
937 	int fd;
938 
939 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
940 	if (fd < 0) {
941 		syslog(LOG_ERR, "%s: %m", file);
942 		exit(1);
943 	}
944 	return (fd);
945 }
946 
947 static void
948 usage(const char *fmt, ...)
949 {
950 	va_list ap;
951 	va_start(ap, fmt);
952 	(void)vsyslog(LOG_ERR, fmt, ap);
953 	va_end(ap);
954 	(void)syslog(LOG_ERR,
955 	    "Usage: %s [-cfnvz] [-N system] [-Z level] [directory]",
956 	    getprogname());
957 	exit(1);
958 }
959