savecore.c revision 1.88
1/*	$NetBSD: savecore.c,v 1.88 2018/12/27 21:25:46 mrg 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
40static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41#else
42__RCSID("$NetBSD: savecore.c,v 1.88 2018/12/27 21:25:46 mrg 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
74extern FILE *zopen(const char *fname, const char *mode);
75
76/*
77 * Note that KREAD_LOGWARN takes a variable name, not pointer to it, unlike
78 * KREAD() itself.
79 */
80#define	KREAD(kd, addr, p)\
81	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
82#define KREAD_LOGWARN(kd, addr, p, err)					\
83do {									\
84	if (KREAD(kd, addr, &(p)) != 0) {				\
85		syslog(LOG_WARNING, "%s:%d: kvm_read " #p ": %s",	\
86			__func__, __LINE__, kvm_geterr(kd));		\
87		err;							\
88	}								\
89} while (0)
90
91static struct nlist current_nl[] = {	/* Namelist for currently running system. */
92#define	X_DUMPDEV	0
93	{ .n_name = "_dumpdev" },
94#define	X_DUMPLO	1
95	{ .n_name = "_dumplo" },
96#define	X_TIME_SECOND	2
97	{ .n_name = "_time_second" },
98#define X_TIME		3
99	{ .n_name = "_time" },
100#define	X_DUMPSIZE	4
101	{ .n_name = "_dumpsize" },
102#define	X_VERSION	5
103	{ .n_name = "_version" },
104#define	X_DUMPMAG	6
105	{ .n_name = "_dumpmag" },
106#define	X_PANICSTR	7
107	{ .n_name = "_panicstr" },
108#define	X_PANICSTART	8
109	{ .n_name = "_panicstart" },
110#define	X_PANICEND	9
111	{ .n_name = "_panicend" },
112#define	X_MSGBUF	10
113	{ .n_name = "_msgbufp" },
114#define	X_DUMPCDEV	11
115	{ .n_name = "_dumpcdev" },
116#define X_SYMSZ		12
117	{ .n_name = "_ksyms_symsz" },
118#define X_STRSZ		13
119	{ .n_name = "_ksyms_strsz" },
120#define X_KHDR		14
121	{ .n_name = "_ksyms_hdr" },
122#define X_SYMTABS	15
123	{ .n_name = "_ksyms_symtabs" },
124	{ .n_name = NULL },
125};
126static int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, X_DUMPCDEV, -1 };
127static int dumpsyms[] = { X_TIME_SECOND, X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR,
128    X_DUMPMAG, X_SYMSZ, X_STRSZ, X_KHDR, X_SYMTABS, -1 };
129
130static struct nlist dump_nl[] = {	/* Name list for dumped system. */
131	{ .n_name = "_dumpdev" },	/* Entries MUST be the same as */
132	{ .n_name = "_dumplo" },	/*	those in current_nl[].  */
133	{ .n_name = "_time_second" },
134	{ .n_name = "_time" },
135	{ .n_name = "_dumpsize" },
136	{ .n_name = "_version" },
137	{ .n_name = "_dumpmag" },
138	{ .n_name = "_panicstr" },
139	{ .n_name = "_panicstart" },
140	{ .n_name = "_panicend" },
141	{ .n_name = "_msgbufp" },
142	{ .n_name = "_dumpcdev" },
143	{ .n_name = "_ksyms_symsz" },
144	{ .n_name = "_ksyms_strsz" },
145	{ .n_name = "_ksyms_hdr" },
146	{ .n_name = "_ksyms_symtabs" },
147	{ .n_name = NULL },
148};
149
150/* Types match kernel declarations. */
151static off_t	dumplo;				/* where dump starts on dumpdev */
152static u_int32_t dumpmag;			/* magic number in dump */
153static int	dumpsize;			/* amount of memory dumped */
154static off_t dumpbytes;			/* in bytes */
155
156static const char	*kernel;		/* name of used kernel */
157static const char	*dirname;		/* directory to save dumps in */
158static char	*ddname;			/* name of dump device */
159static dev_t	dumpdev;			/* dump device */
160static dev_t	dumpcdev = NODEV;		/* dump device (char equivalent) */
161static int	dumpfd;				/* read/write descriptor on dev */
162static kvm_t	*kd_dump;			/* kvm descriptor on dev	*/
163static time_t	now;				/* current date */
164static char	panic_mesg[1024];
165static long	panicstr;
166static char	vers[1024];
167static char	gzmode[3];
168
169static void	check_kmem(void);
170static int	check_space(void);
171static void	clear_dump(void);
172static int	Create(char *, int);
173static int	dump_exists(int);
174static char	*find_dev(dev_t, mode_t);
175static int	get_crashtime(void);
176static void	kmem_setup(int);
177static void	Lseek(int, off_t, int);
178static int	Open(const char *, int rw);
179static void	save_core(int);
180__dead static void	usage(const char *fmt, ...) __printflike(1, 2);
181
182int
183main(int argc, char *argv[])
184{
185	int ch, level, testonly, compress, force, clear, verbose;
186	char *ep;
187
188	kernel = NULL;
189	level = 1;		/* default to fastest gzip compression */
190	force = 0;
191	clear = 0;
192	testonly = 0;
193	verbose = 0;
194	compress = 0;
195	gzmode[0] = 'w';
196
197	openlog("savecore", LOG_PERROR, LOG_DAEMON);
198
199	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
200		switch(ch) {
201		case 'c':
202			clear = 1;
203			break;
204		case 'd':		/* Not documented. */
205		case 'v':
206			verbose = 1;
207			break;
208		case 'f':
209			force = 1;
210			break;
211		case 'n':
212			testonly = 1;
213			break;
214		case 'N':
215			kernel = optarg;
216			break;
217		case 'z':
218			compress = 1;
219			break;
220		case 'Z':
221			level = (int)strtol(optarg, &ep, 10);
222			if (level < 0 || level > 9)
223				usage("Invalid compression `%s'", optarg);
224			break;
225		case '?':
226			usage("Missing argument for flag `%c'", optopt);
227		default:
228			usage("Unknown flag `%c'", ch);
229		}
230	argc -= optind;
231	argv += optind;
232
233	if (argc != 0)
234		dirname = argv[0];
235	else
236		dirname = "/var/crash";
237
238	gzmode[1] = level + '0';
239
240	(void)time(&now);
241	kmem_setup(verbose);
242
243	if (clear && !testonly) {
244		clear_dump();
245		exit(0);
246	}
247
248	if (!dump_exists(verbose) && !force)
249		exit(1);
250
251	if (testonly)
252		/* If -n was passed and there was a dump, exit at level 0 */
253		exit(0);
254
255	check_kmem();
256
257	if (panicstr)
258		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
259	else
260		syslog(LOG_ALERT, "reboot");
261
262	if ((!get_crashtime() || !check_space()) && !force)
263		exit(1);
264
265	save_core(compress);
266
267	clear_dump();
268	exit(0);
269}
270
271static void
272kmem_setup(int verbose)
273{
274	long l_dumplo;
275	kvm_t *kd_kern;
276	char errbuf[_POSIX2_LINE_MAX];
277	int i, hdrsz;
278
279	/*
280	 * Some names we need for the currently running system, others for
281	 * the system that was running when the dump was made.  The values
282	 * obtained from the current system are used to look for things in
283	 * /dev/kmem that cannot be found in the kernel namelist, but are
284	 * presumed to be the same (since the disk partitions are probably
285	 * the same!)
286	 */
287	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
288	if (kd_kern == NULL) {
289		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
290		exit(1);
291	}
292	if (kvm_nlist(kd_kern, current_nl) == -1)
293		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
294		    kvm_geterr(kd_kern));
295
296	for (i = 0; cursyms[i] != -1; i++) {
297		if (current_nl[cursyms[i]].n_value != 0)
298			continue;
299		switch (cursyms[i]) {
300		case X_TIME_SECOND:
301		case X_TIME:
302		case X_DUMPCDEV:
303			break;
304		default:
305			syslog(LOG_ERR, "%s: %s not in namelist",
306			    kernel, current_nl[cursyms[i]].n_name);
307			exit(1);
308		}
309	}
310
311	KREAD_LOGWARN(kd_kern, current_nl[X_DUMPDEV].n_value, dumpdev, exit(1));
312	if (dumpdev == NODEV) {
313		syslog(LOG_WARNING, "no core dump (no dumpdev)");
314		exit(1);
315	}
316	KREAD_LOGWARN(kd_kern, current_nl[X_DUMPLO].n_value, l_dumplo, exit(1));
317	if (l_dumplo == -1) {
318		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
319		exit(1);
320	}
321	dumplo = DEV_BSIZE * (off_t) l_dumplo;
322
323	if (verbose)
324		(void)printf("dumplo = %lld (%ld * %ld)\n",
325		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
326	KREAD_LOGWARN(kd_kern, current_nl[X_DUMPMAG].n_value, dumpmag, exit(1));
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		KREAD_LOGWARN(kd_kern, current_nl[X_DUMPCDEV].n_value, dumpcdev,
334		    exit(1));
335		ddname = find_dev(dumpcdev, S_IFCHR);
336	} else
337		ddname = find_dev(dumpdev, S_IFBLK);
338	if (strncmp(ddname, "/dev/cons", 8) == 0 ||
339	    strncmp(ddname, "/dev/tty", 7) == 0 ||
340	    strncmp(ddname, "/dev/pty", 7) == 0 ||
341	    strncmp(ddname, "/dev/pts", 7) == 0) {
342		syslog(LOG_ERR, "dumpdev %s is tty; override kernel", ddname);
343		exit(1);
344	}
345	dumpfd = Open(ddname, O_RDWR);
346
347	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
348	if (kd_dump == NULL) {
349		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
350		exit(1);
351	}
352
353	if (kvm_nlist(kd_dump, dump_nl) == -1)
354		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
355		    kvm_geterr(kd_dump));
356
357	for (i = 0; dumpsyms[i] != -1; i++)
358		if (dump_nl[dumpsyms[i]].n_value == 0 &&
359			dumpsyms[i] != X_TIME_SECOND &&
360			dumpsyms[i] != X_TIME) {
361			syslog(LOG_ERR, "%s: %s not in namelist",
362			    kernel, dump_nl[dumpsyms[i]].n_name);
363			exit(1);
364		}
365	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
366
367	/*
368	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
369	 * checks, ergo no dump is present...
370	 */
371	if (hdrsz == 0) {
372		syslog(LOG_WARNING, "no core dump");
373		exit(1);
374	}
375	if (hdrsz == -1) {
376		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
377		    kvm_geterr(kd_dump));
378		exit(1);
379	}
380	dumplo += hdrsz;
381	kvm_close(kd_kern);
382}
383
384static void
385check_kmem(void)
386{
387	char *cp, *bufdata;
388	struct kern_msgbuf msgbuf, *bufp;
389	long panicloc, panicstart, panicend;
390	char core_vers[1024];
391
392	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
393	    sizeof(core_vers));
394	core_vers[sizeof(core_vers) - 1] = '\0';
395
396	if (strcmp(vers, core_vers) != 0)
397		syslog(LOG_WARNING,
398		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
399		    kvm_getkernelname(kd_dump), vers, core_vers);
400
401	panicstart = panicend = 0;
402	KREAD_LOGWARN(kd_dump, dump_nl[X_PANICSTART].n_value, panicstart,
403	    goto nomsguf);
404	KREAD_LOGWARN(kd_dump, dump_nl[X_PANICEND].n_value, panicend,
405	    goto nomsguf);
406
407	if (panicstart != 0 && panicend != 0) {
408		KREAD_LOGWARN(kd_dump, dump_nl[X_MSGBUF].n_value, bufp,
409		    goto nomsguf);
410		/* Reads msg_bufs[1], but doesn't matter. */
411		KREAD_LOGWARN(kd_dump, (long)bufp, msgbuf,
412		    goto nomsguf);
413		if (msgbuf.msg_magic != MSG_MAGIC) {
414			syslog(LOG_WARNING, "msgbuf magic incorrect (%lx != %lx)",
415			    msgbuf.msg_magic, (long)MSG_MAGIC);
416			goto nomsguf;
417		}
418		bufdata = malloc(msgbuf.msg_bufs);
419		if (bufdata == NULL) {
420			syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
421			goto nomsguf;
422		}
423		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
424		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
425			syslog(LOG_WARNING, "kvm_read dmesg buffer: %s",
426			    kvm_geterr(kd_dump));
427			free(bufdata);
428			goto nomsguf;
429		}
430		cp = panic_mesg;
431		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
432			*cp++ = bufdata[panicstart];
433			panicstart++;
434			if (panicstart >= msgbuf.msg_bufs)
435				panicstart = 0;
436		}
437		/* Don't end in a new-line */
438		cp = &panic_mesg[strlen(panic_mesg)] - 1;
439		if (*cp == '\n')
440			*cp = '\0';
441		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
442		free(bufdata);
443
444		panicstr = 1;	/* anything not zero */
445		return;
446	}
447nomsguf:
448	KREAD_LOGWARN(kd_dump, dump_nl[X_PANICSTR].n_value, panicstr,
449	    return);
450	if (panicstr) {
451		cp = panic_mesg;
452		panicloc = panicstr;
453		do {
454			if (KREAD(kd_dump, panicloc, cp) != 0) {
455				syslog(LOG_WARNING, "kvm_read msgbuf: %s",
456				    kvm_geterr(kd_dump));
457				break;
458			}
459			panicloc++;
460		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
461		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
462	}
463}
464
465static int
466dump_exists(int verbose)
467{
468	u_int32_t newdumpmag;
469
470	/* Read the dump magic and size. */
471	KREAD_LOGWARN(kd_dump, dump_nl[X_DUMPMAG].n_value, newdumpmag, return 0);
472	KREAD_LOGWARN(kd_dump, dump_nl[X_DUMPSIZE].n_value, dumpsize, return 0);
473
474	dumpbytes = (off_t)dumpsize * getpagesize();
475
476	/*
477	 * Return zero if core dump doesn't seem to be there, and note
478	 * it for syslog.  This check and return happens after the dump size
479	 * is read, so dumpsize is whether or not the core is valid (for -f).
480	 */
481	if (newdumpmag != dumpmag) {
482		if (verbose)
483			syslog(LOG_WARNING, "magic number mismatch "
484			    "(%#x != %#x)", newdumpmag, dumpmag);
485		syslog(LOG_WARNING, "no core dump");
486		return (0);
487	}
488	return (1);
489}
490
491static void
492clear_dump(void)
493{
494	if (kvm_dump_inval(kd_dump) == -1)
495		syslog(LOG_ERR, "%s: kvm_dump_inval: %s", ddname,
496		    kvm_geterr(kd_dump));
497
498}
499
500static char buf[1024 * 1024];
501
502static void
503save_kernel(FILE *fp, char *path)
504{
505	int nw, nr, ifd;
506
507	ifd = Open(kernel, O_RDONLY);
508	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
509		nw = fwrite(buf, 1, nr, fp);
510		if (nw != nr) {
511			syslog(LOG_ERR, "%s: %s",
512			    path, strerror(nw == 0 ? EIO : errno));
513			syslog(LOG_WARNING,
514			    "WARNING: kernel may be incomplete");
515			exit(1);
516		}
517	}
518	if (nr < 0) {
519		syslog(LOG_ERR, "%s: %m", kernel);
520		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
521		exit(1);
522	}
523}
524
525static int
526ksymsget(u_long addr, void *ptr, size_t size)
527{
528
529	if ((size_t)kvm_read(kd_dump, addr, ptr, size) != size) {
530		syslog(LOG_WARNING, "kvm_read ksyms: %s", kvm_geterr(kd_dump));
531		return 1;
532	}
533	return 0;
534}
535
536static int
537save_ksyms(FILE *fp, char *path)
538{
539	struct ksyms_hdr khdr;
540	int nw, symsz, strsz;
541	TAILQ_HEAD(, ksyms_symtab) symtabs;
542	struct ksyms_symtab st, *stptr;
543	void *p;
544
545	/* Get basic info and ELF headers, check if ksyms was on. */
546	if (ksymsget(dump_nl[X_KHDR].n_value, &khdr, sizeof(khdr)))
547		return 1;
548	if (ksymsget(dump_nl[X_SYMSZ].n_value, &symsz, sizeof(symsz)))
549		return 1;
550	if (ksymsget(dump_nl[X_STRSZ].n_value, &strsz, sizeof(strsz)))
551		return 1;
552	if (symsz == 0 || strsz == 0)
553		return 1;
554
555	/* Update the ELF section headers for symbols/strings. */
556	khdr.kh_shdr[SYMTAB].sh_size = symsz;
557	khdr.kh_shdr[SYMTAB].sh_info = symsz / sizeof(Elf_Sym);
558	khdr.kh_shdr[STRTAB].sh_offset = symsz +
559	    khdr.kh_shdr[SYMTAB].sh_offset;
560	khdr.kh_shdr[STRTAB].sh_size = strsz;
561
562	/* Write out the ELF headers. */
563	nw = fwrite(&khdr, 1, sizeof(khdr), fp);
564	if (nw != sizeof(khdr)) {
565		syslog(LOG_ERR, "%s: %s",
566		    path, strerror(nw == 0 ? EIO : errno));
567		syslog(LOG_WARNING,
568		    "WARNING: kernel may be incomplete");
569		exit(1);
570        }
571
572        /* Dump symbol table. */
573	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
574		return 1;
575	stptr = TAILQ_FIRST(&symtabs);
576	while (stptr != NULL) {
577		if (ksymsget((u_long)stptr, &st, sizeof(st)))
578			return 1;
579		stptr = TAILQ_NEXT(&st, sd_queue);
580		if ((p = malloc(st.sd_symsize)) == NULL)
581			return 1;
582		if (ksymsget((u_long)st.sd_symstart, p, st.sd_symsize)) {
583			free(p);
584			return 1;
585		}
586		nw = fwrite(p, 1, st.sd_symsize, fp);
587		free(p);
588		if (nw != st.sd_symsize) {
589			syslog(LOG_ERR, "%s: %s",
590			    path, strerror(nw == 0 ? EIO : errno));
591			syslog(LOG_WARNING,
592			    "WARNING: kernel may be incomplete");
593			exit(1);
594		}
595	}
596
597	/* Dump string table. */
598	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
599		return 1;
600	stptr = TAILQ_FIRST(&symtabs);
601	while (stptr != NULL) {
602		if (ksymsget((u_long)stptr, &st, sizeof(st)))
603			return 1;
604		stptr = TAILQ_NEXT(&st, sd_queue);
605		if ((p = malloc(st.sd_symsize)) == NULL)
606			return 1;
607		if (ksymsget((u_long)st.sd_strstart, p, st.sd_strsize)) {
608			free(p);
609			return 1;
610		}
611		nw = fwrite(p, 1, st.sd_strsize, fp);
612		free(p);
613		if (nw != st.sd_strsize) {
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	return 0;
623}
624
625static void
626save_core(int compress)
627{
628	FILE *fp;
629	int bounds, ifd, nr, nw, ofd, tryksyms;
630	char path[MAXPATHLEN], rbuf[MAXPATHLEN];
631	const char *rawp;
632
633	ofd = -1;
634	/*
635	 * Get the current number and update the bounds file.  Do the update
636	 * now, because may fail later and don't want to overwrite anything.
637	 */
638	umask(066);
639	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
640	if ((fp = fopen(path, "r")) == NULL)
641		goto err1;
642	if (fgets(buf, sizeof(buf), fp) == NULL) {
643		if (ferror(fp))
644err1:			syslog(LOG_WARNING, "%s: %m", path);
645		bounds = 0;
646	} else
647		bounds = atoi(buf);
648	if (fp != NULL)
649		(void)fclose(fp);
650	if ((fp = fopen(path, "w")) == NULL)
651		syslog(LOG_ERR, "%s: %m", path);
652	else {
653		(void)fprintf(fp, "%d\n", bounds + 1);
654		(void)fclose(fp);
655	}
656
657	/* Create the core file. */
658	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
659	    dirname, bounds, compress ? ".gz" : "");
660	if (compress) {
661		if ((fp = zopen(path, gzmode)) == NULL) {
662			syslog(LOG_ERR, "%s: %m", path);
663			exit(1);
664		}
665	} else {
666		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
667		fp  = fdopen(ofd, "w");
668		if (fp == NULL) {
669			syslog(LOG_ERR, "%s: fdopen: %m", path);
670			exit(1);
671		}
672	}
673
674	if (dumpcdev == NODEV) {
675		/* Open the raw device. */
676		rawp = getdiskrawname(rbuf, sizeof(rbuf), ddname);
677		if (rawp == NULL) {
678			syslog(LOG_WARNING, "%s: %m; can't convert to raw",
679			    ddname);
680			rawp = ddname;
681		}
682		if ((ifd = open(rawp, O_RDONLY)) == -1) {
683			syslog(LOG_WARNING, "%s: %m; using block device",
684			    rawp);
685			ifd = dumpfd;
686		}
687	} else {
688		rawp = ddname;
689		ifd = dumpfd;
690	}
691
692	/* Seek to the start of the core. */
693	Lseek(ifd, dumplo, SEEK_SET);
694
695	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
696		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
697		    kvm_geterr(kd_dump));
698		exit(1);
699	}
700
701	/* Copy the core file. */
702	syslog(LOG_NOTICE, "writing %score to %s",
703	    compress ? "compressed " : "", path);
704	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
705		char nbuf[7];
706		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
707		(void)printf("%7s\r", nbuf);
708		(void)fflush(stdout);
709		nr = read(ifd, buf, MIN(dumpbytes, (off_t)sizeof(buf)));
710		if (nr <= 0) {
711			if (nr == 0)
712				syslog(LOG_WARNING,
713				    "WARNING: EOF on dump device");
714			else
715				syslog(LOG_ERR, "%s: %m", rawp);
716			goto err2;
717		}
718		nw = fwrite(buf, 1, nr, fp);
719		if (nw != nr) {
720			syslog(LOG_ERR, "%s: %s",
721			    path, strerror(nw == 0 ? EIO : errno));
722err2:			syslog(LOG_WARNING,
723			    "WARNING: core may be incomplete");
724			(void)printf("\n");
725			exit(1);
726		}
727	}
728	if (dumpcdev == NODEV)
729		(void)close(ifd);
730	(void)fclose(fp);
731
732	/* Create a kernel. */
733	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
734	    dirname, bounds, compress ? ".gz" : "");
735	syslog(LOG_NOTICE, "writing %skernel to %s",
736	    compress ? "compressed " : "", path);
737	for (tryksyms = 1;; tryksyms = 0) {
738		if (compress) {
739			if ((fp = zopen(path, gzmode)) == NULL) {
740				syslog(LOG_ERR, "%s: %m", path);
741				exit(1);
742			}
743		} else {
744			ofd = Create(path, S_IRUSR | S_IWUSR);
745			fp  = fdopen(ofd, "w");
746			if (fp == NULL) {
747				syslog(LOG_ERR, "fdopen: %m");
748				exit(1);
749			}
750		}
751		if (tryksyms) {
752			if (!save_ksyms(fp, path))
753				break;
754			(void)fclose(fp);
755			unlink(path);
756		} else {
757			save_kernel(fp, path);
758			break;
759		}
760	}
761	(void)fclose(fp);
762
763	/*
764	 * For development systems where the crash occurs during boot
765	 * to multiuser.
766	 */
767	sync();
768	sleep(1);
769	sync();
770	sleep(1);
771}
772
773static char *
774find_dev(dev_t dev, mode_t type)
775{
776	DIR *dfd;
777	struct dirent *dir;
778	struct stat sb;
779	char *dp, device[MAXPATHLEN + 1], *p;
780	size_t l;
781
782	if ((dfd = opendir(_PATH_DEV)) == NULL) {
783		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
784		exit(1);
785	}
786	strlcpy(device, _PATH_DEV, sizeof(device));
787	p = &device[strlen(device)];
788	l = sizeof(device) - strlen(device);
789	while ((dir = readdir(dfd))) {
790		strlcpy(p, dir->d_name, l);
791		if (lstat(device, &sb)) {
792			syslog(LOG_ERR, "%s: %m", device);
793			continue;
794		}
795		if ((sb.st_mode & S_IFMT) != type)
796			continue;
797		if (dev == sb.st_rdev) {
798			closedir(dfd);
799			if ((dp = strdup(device)) == NULL) {
800				syslog(LOG_ERR, "%m");
801				exit(1);
802			}
803			return (dp);
804		}
805	}
806	closedir(dfd);
807	syslog(LOG_ERR, "can't find device %lld/%lld",
808	    (long long)major(dev), (long long)minor(dev));
809	exit(1);
810}
811
812static int
813get_crashtime(void)
814{
815	time_t dumptime;			/* Time the dump was taken. */
816	struct timeval dtime;
817
818	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
819		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
820			syslog(LOG_WARNING, "kvm_read dumptime: %s (and _time_second "
821			    "is not defined also)", kvm_geterr(kd_dump));
822			return (0);
823		}
824		dumptime = dtime.tv_sec;
825	}
826	if (dumptime == 0) {
827		syslog(LOG_WARNING, "dump time is zero");
828		return (0);
829	}
830	syslog(LOG_INFO, "system went down at %s", ctime(&dumptime));
831#define	LEEWAY	(60 * SECSPERDAY)
832	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
833		syslog(LOG_WARNING, "dump time is unreasonable");
834		return (0);
835	}
836	return (1);
837}
838
839static int
840check_space(void)
841{
842	FILE *fp;
843	off_t minfree, spacefree, kernelsize, needed;
844	struct stat st;
845	struct statvfs fsbuf;
846	char mbuf[100], path[MAXPATHLEN];
847
848	/* XXX assume a reasonable default, unless we find a kernel. */
849	kernelsize = 20 * 1024 * 1024;
850	if (!stat(kernel, &st)) kernelsize = st.st_blocks * S_BLKSIZE;
851	if (statvfs(dirname, &fsbuf) < 0) {
852		syslog(LOG_ERR, "%s: %m", dirname);
853		exit(1);
854	}
855	spacefree = fsbuf.f_bavail;
856	spacefree *= fsbuf.f_frsize;
857	spacefree /= 1024;
858
859	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
860	if ((fp = fopen(path, "r")) == NULL)
861		minfree = 0;
862	else {
863		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
864			minfree = 0;
865		else
866			minfree = atoi(mbuf);
867		(void)fclose(fp);
868	}
869
870	needed = (dumpbytes + kernelsize) / 1024;
871 	if (minfree > 0 && spacefree - needed < minfree) {
872		syslog(LOG_WARNING,
873		    "no dump, not enough free space in %s", dirname);
874		return (0);
875	}
876	if (spacefree - needed < minfree)
877		syslog(LOG_WARNING,
878		    "dump performed, but free space threshold crossed");
879	return (1);
880}
881
882static int
883Open(const char *name, int rw)
884{
885	int fd;
886
887	if ((fd = open(name, rw, 0)) < 0) {
888		syslog(LOG_ERR, "%s: %m", name);
889		exit(1);
890	}
891	return (fd);
892}
893
894static void
895Lseek(int fd, off_t off, int flag)
896{
897	off_t ret;
898
899	ret = lseek(fd, off, flag);
900	if (ret == -1) {
901		syslog(LOG_ERR, "lseek: %m");
902		exit(1);
903	}
904}
905
906static int
907Create(char *file, int mode)
908{
909	int fd;
910
911	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
912	if (fd < 0) {
913		syslog(LOG_ERR, "%s: %m", file);
914		exit(1);
915	}
916	return (fd);
917}
918
919static void
920usage(const char *fmt, ...)
921{
922	va_list ap;
923	va_start(ap, fmt);
924	(void)vsyslog(LOG_ERR, fmt, ap);
925	va_end(ap);
926	(void)syslog(LOG_ERR,
927	    "Usage: %s [-cfnvz] [-N system] [-Z level] [directory]",
928	    getprogname());
929	exit(1);
930}
931