xref: /netbsd-src/sbin/savecore/savecore.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: savecore.c,v 1.65 2004/10/16 03:48:15 dsainty Exp $	*/
2 
3 /*-
4  * Copyright (c) 1986, 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
41 #else
42 __RCSID("$NetBSD: savecore.c,v 1.65 2004/10/16 03:48:15 dsainty Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/mount.h>
48 #include <sys/msgbuf.h>
49 #include <sys/syslog.h>
50 #include <sys/time.h>
51 
52 #include <dirent.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <nlist.h>
56 #include <paths.h>
57 #include <stddef.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <time.h>
62 #include <tzfile.h>
63 #include <unistd.h>
64 #include <util.h>
65 #include <limits.h>
66 #include <kvm.h>
67 
68 extern FILE *zopen(const char *fname, const char *mode);
69 
70 #define	KREAD(kd, addr, p)\
71 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
72 
73 struct nlist current_nl[] = {	/* Namelist for currently running system. */
74 #define	X_DUMPDEV	0
75 	{ "_dumpdev" },
76 #define	X_DUMPLO	1
77 	{ "_dumplo" },
78 #define	X_TIME		2
79 	{ "_time" },
80 #define	X_DUMPSIZE	3
81 	{ "_dumpsize" },
82 #define	X_VERSION	4
83 	{ "_version" },
84 #define	X_DUMPMAG	5
85 	{ "_dumpmag" },
86 #define	X_PANICSTR	6
87 	{ "_panicstr" },
88 #define	X_PANICSTART	7
89 	{ "_panicstart" },
90 #define	X_PANICEND	8
91 	{ "_panicend" },
92 #define	X_MSGBUF	9
93 	{ "_msgbufp" },
94 	{ NULL },
95 };
96 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
97 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
98 
99 struct nlist dump_nl[] = {	/* Name list for dumped system. */
100 	{ "_dumpdev" },		/* Entries MUST be the same as */
101 	{ "_dumplo" },		/*	those in current_nl[].  */
102 	{ "_time" },
103 	{ "_dumpsize" },
104 	{ "_version" },
105 	{ "_dumpmag" },
106 	{ "_panicstr" },
107 	{ "_panicstart" },
108 	{ "_panicend" },
109 	{ "_msgbufp" },
110 	{ NULL },
111 };
112 
113 /* Types match kernel declarations. */
114 off_t	dumplo;				/* where dump starts on dumpdev */
115 u_int32_t dumpmag;			/* magic number in dump */
116 int	dumpsize;			/* amount of memory dumped */
117 off_t dumpbytes;			/* in bytes */
118 
119 const char	*kernel;		/* name of used kernel */
120 char	*dirname;			/* directory to save dumps in */
121 char	*ddname;			/* name of dump device */
122 dev_t	dumpdev;			/* dump device */
123 int	dumpfd;				/* read/write descriptor on block dev */
124 kvm_t	*kd_dump;			/* kvm descriptor on block dev	*/
125 time_t	now;				/* current date */
126 char	panic_mesg[1024];
127 long	panicstr;
128 char	vers[1024];
129 char	gzmode[3];
130 
131 static int	clear, compress, force, verbose;	/* flags */
132 
133 void	check_kmem(void);
134 int	check_space(void);
135 void	clear_dump(void);
136 int	Create(char *, int);
137 int	dump_exists(void);
138 char	*find_dev(dev_t, int);
139 int	get_crashtime(void);
140 void	kmem_setup(void);
141 void	Lseek(int, off_t, int);
142 int	main(int, char *[]);
143 int	Open(const char *, int rw);
144 char	*rawname(char *s);
145 void	save_core(void);
146 void	usage(void);
147 void	Write(int, void *, int);
148 
149 int
150 main(int argc, char *argv[])
151 {
152 	int ch, level, testonly;
153 	char *ep;
154 
155 	dirname = NULL;
156 	kernel = NULL;
157 	level = 1;		/* default to fastest gzip compression */
158 	testonly = 0;
159 	gzmode[0] = 'w';
160 
161 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
162 
163 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
164 		switch(ch) {
165 		case 'c':
166 			clear = 1;
167 			break;
168 		case 'd':		/* Not documented. */
169 		case 'v':
170 			verbose = 1;
171 			break;
172 		case 'f':
173 			force = 1;
174 			break;
175 		case 'n':
176 			testonly = 1;
177 			break;
178 		case 'N':
179 			kernel = optarg;
180 			break;
181 		case 'z':
182 			compress = 1;
183 			break;
184 		case 'Z':
185 			level = (int)strtol(optarg, &ep, 10);
186 			if (level < 0 || level > 9) {
187 				(void)syslog(LOG_ERR, "invalid compression %s",
188 				    optarg);
189 				usage();
190 			}
191 			break;
192 		case '?':
193 		default:
194 			usage();
195 		}
196 	argc -= optind;
197 	argv += optind;
198 
199 	if (argc != ((clear || testonly) ? 0 : 1))
200 		usage();
201 
202 	gzmode[1] = level + '0';
203 	if (!clear)
204 		dirname = argv[0];
205 
206 	if (kernel == NULL) {
207 		kernel = getbootfile();
208 	}
209 
210 	(void)time(&now);
211 	kmem_setup();
212 
213 	if (clear && !testonly) {
214 		clear_dump();
215 		exit(0);
216 	}
217 
218 	if (!dump_exists() && !force)
219 		exit(1);
220 
221 	if (testonly)
222 		/* If -n was passed and there was a dump, exit at level 0 */
223 		exit(0);
224 
225 	check_kmem();
226 
227 	if (panicstr)
228 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
229 	else
230 		syslog(LOG_ALERT, "reboot");
231 
232 	if ((!get_crashtime() || !check_space()) && !force)
233 		exit(1);
234 
235 	save_core();
236 
237 	clear_dump();
238 	exit(0);
239 }
240 
241 void
242 kmem_setup(void)
243 {
244 	kvm_t *kd_kern;
245 	char errbuf[_POSIX2_LINE_MAX];
246 	int i, hdrsz;
247 
248 	/*
249 	 * Some names we need for the currently running system, others for
250 	 * the system that was running when the dump was made.  The values
251 	 * obtained from the current system are used to look for things in
252 	 * /dev/kmem that cannot be found in the kernel namelist, but are
253 	 * presumed to be the same (since the disk partitions are probably
254 	 * the same!)
255 	 */
256 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
257 	if (kd_kern == NULL) {
258 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
259 		exit(1);
260 	}
261 	if (kvm_nlist(kd_kern, current_nl) == -1)
262 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
263 		    kvm_geterr(kd_kern));
264 
265 	for (i = 0; cursyms[i] != -1; i++)
266 		if (current_nl[cursyms[i]].n_value == 0) {
267 			syslog(LOG_ERR, "%s: %s not in namelist",
268 			    kernel, current_nl[cursyms[i]].n_name);
269 			exit(1);
270 		}
271 
272 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
273 		if (verbose)
274 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
275 		exit(1);
276 	}
277 	if (dumpdev == NODEV) {
278 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
279 		exit(1);
280 	}
281 	{
282 	    long l_dumplo;
283 
284 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
285 		    if (verbose)
286 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
287 		    exit(1);
288 	    }
289 	    if (l_dumplo == -1) {
290 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
291 		exit(1);
292 	    }
293 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
294 	}
295 
296 	if (verbose)
297 		(void)printf("dumplo = %lld (%ld * %ld)\n",
298 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
299 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
300 		if (verbose)
301 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
302 		exit(1);
303 	}
304 
305 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
306 	    sizeof(vers));
307 	vers[sizeof(vers) - 1] = '\0';
308 
309 	ddname = find_dev(dumpdev, S_IFBLK);
310 	dumpfd = Open(ddname, O_RDWR);
311 
312 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
313 	if (kd_dump == NULL) {
314 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
315 		exit(1);
316 	}
317 
318 	if (kvm_nlist(kd_dump, dump_nl) == -1)
319 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
320 		    kvm_geterr(kd_dump));
321 
322 	for (i = 0; dumpsyms[i] != -1; i++)
323 		if (dump_nl[dumpsyms[i]].n_value == 0) {
324 			syslog(LOG_ERR, "%s: %s not in namelist",
325 			    kernel, dump_nl[dumpsyms[i]].n_name);
326 			exit(1);
327 		}
328 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
329 
330 	/*
331 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
332 	 * checks, ergo no dump is present...
333 	 */
334 	if (hdrsz == 0) {
335 		syslog(LOG_WARNING, "no core dump");
336 		exit(1);
337 	}
338 	if (hdrsz == -1) {
339 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
340 		    kvm_geterr(kd_dump));
341 		exit(1);
342 	}
343 	dumplo += hdrsz;
344 	kvm_close(kd_kern);
345 }
346 
347 void
348 check_kmem(void)
349 {
350 	char *cp, *bufdata;
351 	struct kern_msgbuf msgbuf, *bufp;
352 	long panicloc, panicstart, panicend;
353 	char core_vers[1024];
354 
355 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
356 	    sizeof(core_vers));
357 	core_vers[sizeof(core_vers) - 1] = '\0';
358 
359 	if (strcmp(vers, core_vers) != 0)
360 		syslog(LOG_WARNING,
361 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
362 		    kernel, vers, core_vers);
363 
364 	panicstart = panicend = 0;
365 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
366 		if (verbose)
367 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
368 		goto nomsguf;
369 	}
370 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
371 		if (verbose)
372 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
373 		goto nomsguf;
374 	}
375 	if (panicstart != 0 && panicend != 0) {
376 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
377 			if (verbose)
378 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
379 			goto nomsguf;
380 		}
381 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
382 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
383 		    offsetof(struct kern_msgbuf, msg_bufc)) {
384 			if (verbose)
385 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
386 			goto nomsguf;
387 		}
388 		if (msgbuf.msg_magic != MSG_MAGIC) {
389 			if (verbose)
390 				syslog(LOG_WARNING, "msgbuf magic incorrect");
391 			goto nomsguf;
392 		}
393 		bufdata = malloc(msgbuf.msg_bufs);
394 		if (bufdata == NULL) {
395 			if (verbose)
396 				syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
397 			goto nomsguf;
398 		}
399 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
400 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
401 			if (verbose)
402 				syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
403 			goto nomsguf;
404 		}
405 		cp = panic_mesg;
406 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
407 			*cp++ = bufdata[panicstart];
408 			panicstart++;
409 			if (panicstart >= msgbuf.msg_bufs)
410 				panicstart = 0;
411 		}
412 		/* Don't end in a new-line */
413 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
414 		if (*cp == '\n')
415 			*cp = '\0';
416 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
417 
418 		panicstr = 1;	/* anything not zero */
419 		return;
420 	}
421 nomsguf:
422 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
423 		if (verbose)
424 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
425 		return;
426 	}
427 	if (panicstr) {
428 		cp = panic_mesg;
429 		panicloc = panicstr;
430 		do {
431 			if (KREAD(kd_dump, panicloc, cp) != 0) {
432 				if (verbose)
433 				    syslog(LOG_WARNING, "kvm_read: %s",
434 					kvm_geterr(kd_dump));
435 				break;
436 			}
437 			panicloc++;
438 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
439 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
440 	}
441 }
442 
443 int
444 dump_exists(void)
445 {
446 	u_int32_t newdumpmag;
447 
448 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
449 		if (verbose)
450 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
451 		return (0);
452 	}
453 
454 	/* Read the dump size. */
455 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
456 		if (verbose)
457 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
458 		return (0);
459 	}
460 	dumpbytes = (off_t)dumpsize * getpagesize();
461 
462 	/*
463 	 * Return zero if core dump doesn't seem to be there, and note
464 	 * it for syslog.  This check and return happens after the dump size
465 	 * is read, so dumpsize is whether or not the core is valid (for -f).
466 	 */
467 	if (newdumpmag != dumpmag) {
468 		if (verbose)
469 			syslog(LOG_WARNING,
470 			    "magic number mismatch (0x%x != 0x%x)",
471 			    newdumpmag, dumpmag);
472 		syslog(LOG_WARNING, "no core dump");
473 		return (0);
474 	}
475 	return (1);
476 }
477 
478 void
479 clear_dump(void)
480 {
481 	if (kvm_dump_inval(kd_dump) == -1)
482 		syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
483 		    kvm_geterr(kd_dump));
484 
485 }
486 
487 char buf[1024 * 1024];
488 
489 void
490 save_core(void)
491 {
492 	FILE *fp;
493 	int bounds, ifd, nr, nw, ofd;
494 	char *rawp, path[MAXPATHLEN];
495 
496 	ofd = -1;
497 	/*
498 	 * Get the current number and update the bounds file.  Do the update
499 	 * now, because may fail later and don't want to overwrite anything.
500 	 */
501 	umask(066);
502 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
503 	if ((fp = fopen(path, "r")) == NULL)
504 		goto err1;
505 	if (fgets(buf, sizeof(buf), fp) == NULL) {
506 		if (ferror(fp))
507 err1:			syslog(LOG_WARNING, "%s: %m", path);
508 		bounds = 0;
509 	} else
510 		bounds = atoi(buf);
511 	if (fp != NULL)
512 		(void)fclose(fp);
513 	if ((fp = fopen(path, "w")) == NULL)
514 		syslog(LOG_ERR, "%s: %m", path);
515 	else {
516 		(void)fprintf(fp, "%d\n", bounds + 1);
517 		(void)fclose(fp);
518 	}
519 
520 	/* Create the core file. */
521 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
522 	    dirname, bounds, compress ? ".gz" : "");
523 	if (compress) {
524 		if ((fp = zopen(path, gzmode)) == NULL) {
525 			syslog(LOG_ERR, "%s: %m", path);
526 			exit(1);
527 		}
528 	} else {
529 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
530 		fp  = fdopen(ofd, "w");
531 		if (fp == NULL) {
532 			syslog(LOG_ERR, "%s: fdopen: %m", path);
533 			exit(1);
534 		}
535 	}
536 
537 	/* Open the raw device. */
538 	rawp = rawname(ddname);
539 	if ((ifd = open(rawp, O_RDONLY)) == -1) {
540 		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
541 		ifd = dumpfd;
542 	}
543 
544 	/* Seek to the start of the core. */
545 	Lseek(ifd, dumplo, SEEK_SET);
546 
547 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
548 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
549 		    kvm_geterr(kd_dump));
550 		exit(1);
551 	}
552 
553 	/* Copy the core file. */
554 	syslog(LOG_NOTICE, "writing %score to %s",
555 	    compress ? "compressed " : "", path);
556 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
557 		char nbuf[7];
558 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
559 		(void)printf("%7s\r", nbuf);
560 		(void)fflush(stdout);
561 		nr = read(ifd, buf, MIN(dumpbytes, sizeof(buf)));
562 		if (nr <= 0) {
563 			if (nr == 0)
564 				syslog(LOG_WARNING,
565 				    "WARNING: EOF on dump device");
566 			else
567 				syslog(LOG_ERR, "%s: %m", rawp);
568 			goto err2;
569 		}
570 		nw = fwrite(buf, 1, nr, fp);
571 		if (nw != nr) {
572 			syslog(LOG_ERR, "%s: %s",
573 			    path, strerror(nw == 0 ? EIO : errno));
574 err2:			syslog(LOG_WARNING,
575 			    "WARNING: core may be incomplete");
576 			(void)printf("\n");
577 			exit(1);
578 		}
579 	}
580 	(void)close(ifd);
581 	(void)fclose(fp);
582 
583 	/* Copy the kernel. */
584 	ifd = Open(kernel, O_RDONLY);
585 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
586 	    dirname, bounds, compress ? ".gz" : "");
587 	if (compress) {
588 		if ((fp = zopen(path, gzmode)) == NULL) {
589 			syslog(LOG_ERR, "%s: %m", path);
590 			exit(1);
591 		}
592 	} else
593 		ofd = Create(path, S_IRUSR | S_IWUSR);
594 	syslog(LOG_NOTICE, "writing %skernel to %s",
595 	    compress ? "compressed " : "", path);
596 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
597 		if (compress)
598 			nw = fwrite(buf, 1, nr, fp);
599 		else
600 			nw = write(ofd, buf, nr);
601 		if (nw != nr) {
602 			syslog(LOG_ERR, "%s: %s",
603 			    path, strerror(nw == 0 ? EIO : errno));
604 			syslog(LOG_WARNING,
605 			    "WARNING: kernel may be incomplete");
606 			exit(1);
607 		}
608 	}
609 	if (nr < 0) {
610 		syslog(LOG_ERR, "%s: %m", kernel);
611 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
612 		exit(1);
613 	}
614 	if (compress)
615 		(void)fclose(fp);
616 	else
617 		(void)close(ofd);
618 }
619 
620 char *
621 find_dev(dev_t dev, int type)
622 {
623 	DIR *dfd;
624 	struct dirent *dir;
625 	struct stat sb;
626 	char *dp, device[MAXPATHLEN + 1], *p;
627 	size_t l;
628 
629 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
630 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
631 		exit(1);
632 	}
633 	strlcpy(device, _PATH_DEV, sizeof(device));
634 	p = &device[strlen(device)];
635 	l = sizeof(device) - strlen(device);
636 	while ((dir = readdir(dfd))) {
637 		strlcpy(p, dir->d_name, l);
638 		if (lstat(device, &sb)) {
639 			syslog(LOG_ERR, "%s: %m", device);
640 			continue;
641 		}
642 		if ((sb.st_mode & S_IFMT) != type)
643 			continue;
644 		if (dev == sb.st_rdev) {
645 			closedir(dfd);
646 			if ((dp = strdup(device)) == NULL) {
647 				syslog(LOG_ERR, "%m");
648 				exit(1);
649 			}
650 			return (dp);
651 		}
652 	}
653 	closedir(dfd);
654 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
655 	exit(1);
656 }
657 
658 char *
659 rawname(char *s)
660 {
661 	char *sl;
662 	char name[MAXPATHLEN];
663 
664 	if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
665 		syslog(LOG_ERR,
666 		    "can't make raw dump device name from %s", s);
667 		return (s);
668 	}
669 	(void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
670 	    sl + 1);
671 	if ((sl = strdup(name)) == NULL) {
672 		syslog(LOG_ERR, "%m");
673 		exit(1);
674 	}
675 	return (sl);
676 }
677 
678 int
679 get_crashtime(void)
680 {
681 	struct timeval dtime;
682 	time_t dumptime;			/* Time the dump was taken. */
683 
684 	if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
685 		if (verbose)
686 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
687 		return (0);
688 	}
689 	dumptime = dtime.tv_sec;
690 	if (dumptime == 0) {
691 		if (verbose)
692 			syslog(LOG_ERR, "dump time is zero");
693 		return (0);
694 	}
695 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
696 #define	LEEWAY	(60 * SECSPERDAY)
697 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
698 		(void)printf("dump time is unreasonable\n");
699 		return (0);
700 	}
701 	return (1);
702 }
703 
704 int
705 check_space(void)
706 {
707 	FILE *fp;
708 	off_t minfree, spacefree, kernelsize, needed;
709 	struct stat st;
710 	struct statvfs fsbuf;
711 	char mbuf[100], path[MAXPATHLEN];
712 
713 #ifdef __GNUC__
714 	(void) &minfree;
715 #endif
716 
717 	if (stat(kernel, &st) < 0) {
718 		syslog(LOG_ERR, "%s: %m", kernel);
719 		exit(1);
720 	}
721 	kernelsize = st.st_blocks * S_BLKSIZE;
722 	if (statvfs(dirname, &fsbuf) < 0) {
723 		syslog(LOG_ERR, "%s: %m", dirname);
724 		exit(1);
725 	}
726 	spacefree = fsbuf.f_bavail;
727 	spacefree *= fsbuf.f_frsize;
728 	spacefree /= 1024;
729 
730 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
731 	if ((fp = fopen(path, "r")) == NULL)
732 		minfree = 0;
733 	else {
734 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
735 			minfree = 0;
736 		else
737 			minfree = atoi(mbuf);
738 		(void)fclose(fp);
739 	}
740 
741 	needed = (dumpbytes + kernelsize) / 1024;
742  	if (minfree > 0 && spacefree - needed < minfree) {
743 		syslog(LOG_WARNING,
744 		    "no dump, not enough free space in %s", dirname);
745 		return (0);
746 	}
747 	if (spacefree - needed < minfree)
748 		syslog(LOG_WARNING,
749 		    "dump performed, but free space threshold crossed");
750 	return (1);
751 }
752 
753 int
754 Open(const char *name, int rw)
755 {
756 	int fd;
757 
758 	if ((fd = open(name, rw, 0)) < 0) {
759 		syslog(LOG_ERR, "%s: %m", name);
760 		exit(1);
761 	}
762 	return (fd);
763 }
764 
765 void
766 Lseek(int fd, off_t off, int flag)
767 {
768 	off_t ret;
769 
770 	ret = lseek(fd, off, flag);
771 	if (ret == -1) {
772 		syslog(LOG_ERR, "lseek: %m");
773 		exit(1);
774 	}
775 }
776 
777 int
778 Create(char *file, int mode)
779 {
780 	int fd;
781 
782 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
783 	if (fd < 0) {
784 		syslog(LOG_ERR, "%s: %m", file);
785 		exit(1);
786 	}
787 	return (fd);
788 }
789 
790 void
791 Write(int fd, void *bp, int size)
792 {
793 	int n;
794 
795 	if ((n = write(fd, bp, size)) < size) {
796 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
797 		exit(1);
798 	}
799 }
800 
801 void
802 usage(void)
803 {
804 	(void)syslog(LOG_ERR,
805 	    "usage: savecore [-cfnvz] [-N system] [-Z level] directory");
806 	exit(1);
807 }
808