savecore.c revision 1.83
1/*	$NetBSD: savecore.c,v 1.83 2011/09/12 21:22:07 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
40static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41#else
42__RCSID("$NetBSD: savecore.c,v 1.83 2011/09/12 21:22:07 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
74extern 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
79static 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};
114static int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, X_DUMPCDEV, -1 };
115static 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
118static 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. */
139static off_t	dumplo;				/* where dump starts on dumpdev */
140static u_int32_t dumpmag;			/* magic number in dump */
141static int	dumpsize;			/* amount of memory dumped */
142static off_t dumpbytes;			/* in bytes */
143
144static const char	*kernel;		/* name of used kernel */
145static const char	*dirname;		/* directory to save dumps in */
146static char	*ddname;			/* name of dump device */
147static dev_t	dumpdev;			/* dump device */
148static dev_t	dumpcdev = NODEV;		/* dump device (char equivalent) */
149static int	dumpfd;				/* read/write descriptor on dev */
150static kvm_t	*kd_dump;			/* kvm descriptor on dev	*/
151static time_t	now;				/* current date */
152static char	panic_mesg[1024];
153static long	panicstr;
154static char	vers[1024];
155static char	gzmode[3];
156
157static int	clear, compress, force, verbose;	/* flags */
158
159static void	check_kmem(void);
160static int	check_space(void);
161static void	clear_dump(void);
162static int	Create(char *, int);
163static int	dump_exists(void);
164static char	*find_dev(dev_t, mode_t);
165static int	get_crashtime(void);
166static void	kmem_setup(void);
167static void	Lseek(int, off_t, int);
168static int	Open(const char *, int rw);
169static char	*rawname(char *s);
170static void	save_core(void);
171__dead static void	usage(const char *fmt, ...) __printflike(1, 2);
172
173int
174main(int argc, char *argv[])
175{
176	int ch, level, testonly;
177	char *ep;
178
179	kernel = NULL;
180	level = 1;		/* default to fastest gzip compression */
181	testonly = 0;
182	gzmode[0] = 'w';
183
184	openlog("savecore", LOG_PERROR, LOG_DAEMON);
185
186	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
187		switch(ch) {
188		case 'c':
189			clear = 1;
190			break;
191		case 'd':		/* Not documented. */
192		case 'v':
193			verbose = 1;
194			break;
195		case 'f':
196			force = 1;
197			break;
198		case 'n':
199			testonly = 1;
200			break;
201		case 'N':
202			kernel = optarg;
203			break;
204		case 'z':
205			compress = 1;
206			break;
207		case 'Z':
208			level = (int)strtol(optarg, &ep, 10);
209			if (level < 0 || level > 9)
210				usage("Invalid compression `%s'", optarg);
211			break;
212		case '?':
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
257static void
258kmem_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
386static void
387check_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	}
455nomsguf:
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
475static int
476dump_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
507static void
508clear_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
516static char buf[1024 * 1024];
517
518static void
519save_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
544static int
545ksymsget(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
555static int
556save_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
653static void
654save_core(void)
655{
656	FILE *fp;
657	int bounds, ifd, nr, nw, ofd, tryksyms;
658	char *rawp, path[MAXPATHLEN];
659
660	ofd = -1;
661	/*
662	 * Get the current number and update the bounds file.  Do the update
663	 * now, because may fail later and don't want to overwrite anything.
664	 */
665	umask(066);
666	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
667	if ((fp = fopen(path, "r")) == NULL)
668		goto err1;
669	if (fgets(buf, sizeof(buf), fp) == NULL) {
670		if (ferror(fp))
671err1:			syslog(LOG_WARNING, "%s: %m", path);
672		bounds = 0;
673	} else
674		bounds = atoi(buf);
675	if (fp != NULL)
676		(void)fclose(fp);
677	if ((fp = fopen(path, "w")) == NULL)
678		syslog(LOG_ERR, "%s: %m", path);
679	else {
680		(void)fprintf(fp, "%d\n", bounds + 1);
681		(void)fclose(fp);
682	}
683
684	/* Create the core file. */
685	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
686	    dirname, bounds, compress ? ".gz" : "");
687	if (compress) {
688		if ((fp = zopen(path, gzmode)) == NULL) {
689			syslog(LOG_ERR, "%s: %m", path);
690			exit(1);
691		}
692	} else {
693		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
694		fp  = fdopen(ofd, "w");
695		if (fp == NULL) {
696			syslog(LOG_ERR, "%s: fdopen: %m", path);
697			exit(1);
698		}
699	}
700
701	if (dumpcdev == NODEV) {
702		/* Open the raw device. */
703		rawp = rawname(ddname);
704		if ((ifd = open(rawp, O_RDONLY)) == -1) {
705			syslog(LOG_WARNING, "%s: %m; using block device",
706			    rawp);
707			ifd = dumpfd;
708		}
709	} else {
710		rawp = ddname;
711		ifd = dumpfd;
712	}
713
714	/* Seek to the start of the core. */
715	Lseek(ifd, dumplo, SEEK_SET);
716
717	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
718		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
719		    kvm_geterr(kd_dump));
720		exit(1);
721	}
722
723	/* Copy the core file. */
724	syslog(LOG_NOTICE, "writing %score to %s",
725	    compress ? "compressed " : "", path);
726	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
727		char nbuf[7];
728		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
729		(void)printf("%7s\r", nbuf);
730		(void)fflush(stdout);
731		nr = read(ifd, buf, MIN(dumpbytes, (off_t)sizeof(buf)));
732		if (nr <= 0) {
733			if (nr == 0)
734				syslog(LOG_WARNING,
735				    "WARNING: EOF on dump device");
736			else
737				syslog(LOG_ERR, "%s: %m", rawp);
738			goto err2;
739		}
740		nw = fwrite(buf, 1, nr, fp);
741		if (nw != nr) {
742			syslog(LOG_ERR, "%s: %s",
743			    path, strerror(nw == 0 ? EIO : errno));
744err2:			syslog(LOG_WARNING,
745			    "WARNING: core may be incomplete");
746			(void)printf("\n");
747			exit(1);
748		}
749	}
750	if (dumpcdev == NODEV)
751		(void)close(ifd);
752	(void)fclose(fp);
753
754	/* Create a kernel. */
755	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
756	    dirname, bounds, compress ? ".gz" : "");
757	syslog(LOG_NOTICE, "writing %skernel to %s",
758	    compress ? "compressed " : "", path);
759	for (tryksyms = 1;; tryksyms = 0) {
760		if (compress) {
761			if ((fp = zopen(path, gzmode)) == NULL) {
762				syslog(LOG_ERR, "%s: %m", path);
763				exit(1);
764			}
765		} else
766			ofd = Create(path, S_IRUSR | S_IWUSR);
767		if (tryksyms) {
768			if (!save_ksyms(ofd, fp, path))
769				break;
770			if (compress)
771				(void)fclose(fp);
772			else
773				(void)close(ofd);
774			unlink(path);
775		} else {
776			save_kernel(ofd, fp, path);
777			break;
778		}
779	}
780	if (compress)
781		(void)fclose(fp);
782	else
783		(void)close(ofd);
784
785	/*
786	 * For development systems where the crash occurs during boot
787	 * to multiuser.
788	 */
789	sync();
790	sleep(1);
791	sync();
792	sleep(1);
793}
794
795static char *
796find_dev(dev_t dev, mode_t type)
797{
798	DIR *dfd;
799	struct dirent *dir;
800	struct stat sb;
801	char *dp, device[MAXPATHLEN + 1], *p;
802	size_t l;
803
804	if ((dfd = opendir(_PATH_DEV)) == NULL) {
805		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
806		exit(1);
807	}
808	strlcpy(device, _PATH_DEV, sizeof(device));
809	p = &device[strlen(device)];
810	l = sizeof(device) - strlen(device);
811	while ((dir = readdir(dfd))) {
812		strlcpy(p, dir->d_name, l);
813		if (lstat(device, &sb)) {
814			syslog(LOG_ERR, "%s: %m", device);
815			continue;
816		}
817		if ((sb.st_mode & S_IFMT) != type)
818			continue;
819		if (dev == sb.st_rdev) {
820			closedir(dfd);
821			if ((dp = strdup(device)) == NULL) {
822				syslog(LOG_ERR, "%m");
823				exit(1);
824			}
825			return (dp);
826		}
827	}
828	closedir(dfd);
829	syslog(LOG_ERR, "can't find device %lld/%lld",
830	    (long long)major(dev), (long long)minor(dev));
831	exit(1);
832}
833
834static char *
835rawname(char *s)
836{
837	char *sl;
838	char name[MAXPATHLEN];
839
840	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
841		syslog(LOG_ERR,
842		    "can't make raw dump device name from %s", s);
843		return (s);
844	}
845	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
846	    sl + 1);
847	if ((sl = strdup(name)) == NULL) {
848		syslog(LOG_ERR, "%m");
849		exit(1);
850	}
851	return (sl);
852}
853
854static int
855get_crashtime(void)
856{
857	time_t dumptime;			/* Time the dump was taken. */
858	struct timeval dtime;
859
860	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
861		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
862			syslog(LOG_WARNING, "kvm_read: %s (and _time_second "
863			    "is not defined also)", kvm_geterr(kd_dump));
864			return (0);
865		}
866		dumptime = dtime.tv_sec;
867	}
868	if (dumptime == 0) {
869		syslog(LOG_WARNING, "dump time is zero");
870		return (0);
871	}
872	syslog(LOG_INFO, "system went down at %s", ctime(&dumptime));
873#define	LEEWAY	(60 * SECSPERDAY)
874	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
875		syslog(LOG_WARNING, "dump time is unreasonable");
876		return (0);
877	}
878	return (1);
879}
880
881static int
882check_space(void)
883{
884	FILE *fp;
885	off_t minfree, spacefree, kernelsize, needed;
886	struct stat st;
887	struct statvfs fsbuf;
888	char mbuf[100], path[MAXPATHLEN];
889
890	/* XXX assume a reasonable default, unless we find a kernel. */
891	kernelsize = 20 * 1024 * 1024;
892	if (!stat(kernel, &st)) kernelsize = st.st_blocks * S_BLKSIZE;
893	if (statvfs(dirname, &fsbuf) < 0) {
894		syslog(LOG_ERR, "%s: %m", dirname);
895		exit(1);
896	}
897	spacefree = fsbuf.f_bavail;
898	spacefree *= fsbuf.f_frsize;
899	spacefree /= 1024;
900
901	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
902	if ((fp = fopen(path, "r")) == NULL)
903		minfree = 0;
904	else {
905		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
906			minfree = 0;
907		else
908			minfree = atoi(mbuf);
909		(void)fclose(fp);
910	}
911
912	needed = (dumpbytes + kernelsize) / 1024;
913 	if (minfree > 0 && spacefree - needed < minfree) {
914		syslog(LOG_WARNING,
915		    "no dump, not enough free space in %s", dirname);
916		return (0);
917	}
918	if (spacefree - needed < minfree)
919		syslog(LOG_WARNING,
920		    "dump performed, but free space threshold crossed");
921	return (1);
922}
923
924static int
925Open(const char *name, int rw)
926{
927	int fd;
928
929	if ((fd = open(name, rw, 0)) < 0) {
930		syslog(LOG_ERR, "%s: %m", name);
931		exit(1);
932	}
933	return (fd);
934}
935
936static void
937Lseek(int fd, off_t off, int flag)
938{
939	off_t ret;
940
941	ret = lseek(fd, off, flag);
942	if (ret == -1) {
943		syslog(LOG_ERR, "lseek: %m");
944		exit(1);
945	}
946}
947
948static int
949Create(char *file, int mode)
950{
951	int fd;
952
953	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
954	if (fd < 0) {
955		syslog(LOG_ERR, "%s: %m", file);
956		exit(1);
957	}
958	return (fd);
959}
960
961static void
962usage(const char *fmt, ...)
963{
964	va_list ap;
965	va_start(ap, fmt);
966	(void)vsyslog(LOG_ERR, fmt, ap);
967	va_end(ap);
968	(void)syslog(LOG_ERR,
969	    "Usage: %s [-cfnvz] [-N system] [-Z level] [directory]",
970	    getprogname());
971	exit(1);
972}
973