xref: /freebsd/sbin/savecore/savecore.c (revision 8e537d168674d6b65869f73c20813001af875738)
1 /*-
2  * Copyright (c) 1986, 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static char copyright[] =
36 "@(#) Copyright (c) 1986, 1992, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static char sccsid[] = "@(#)savecore.c	8.3 (Berkeley) 1/2/94";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/stat.h>
46 #include <sys/mount.h>
47 #include <sys/syslog.h>
48 #include <sys/time.h>
49 
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <vm/pmap.h>
53 
54 #include <dirent.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <nlist.h>
58 #include <paths.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <unistd.h>
63 #include "zopen.h"
64 
65 #define ok(number) ((number) - KERNBASE)
66 
67 struct nlist current_nl[] = {	/* Namelist for currently running system. */
68 #define X_DUMPDEV	0
69 	{ "_dumpdev" },
70 #define X_DUMPLO	1
71 	{ "_dumplo" },
72 #define X_TIME		2
73 	{ "_time" },
74 #define	X_DUMPSIZE	3
75 	{ "_dumpsize" },
76 #define X_VERSION	4
77 	{ "_version" },
78 #define X_PANICSTR	5
79 	{ "_panicstr" },
80 #define	X_DUMPMAG	6
81 	{ "_dumpmag" },
82 	{ "" },
83 };
84 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
85 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
86 
87 struct nlist dump_nl[] = {	/* Name list for dumped system. */
88 	{ "_dumpdev" },		/* Entries MUST be the same as */
89 	{ "_dumplo" },		/*	those in current_nl[].  */
90 	{ "_time" },
91 	{ "_dumpsize" },
92 	{ "_version" },
93 	{ "_panicstr" },
94 	{ "_dumpmag" },
95 	{ "" },
96 };
97 
98 /* Types match kernel declarations. */
99 long	dumplo;				/* where dump starts on dumpdev */
100 int	dumpmag;			/* magic number in dump */
101 int	dumpsize;			/* amount of memory dumped */
102 
103 char	*kernel;
104 char	*dirname;			/* directory to save dumps in */
105 char	*ddname;			/* name of dump device */
106 dev_t	dumpdev;			/* dump device */
107 int	dumpfd;				/* read/write descriptor on block dev */
108 time_t	now;				/* current date */
109 char	panic_mesg[1024];
110 int	panicstr;
111 char	vers[1024];
112 
113 int	clear, compress, force, verbose;	/* flags */
114 
115 void	 check_kmem __P((void));
116 int	 check_space __P((void));
117 void	 clear_dump __P((void));
118 int	 Create __P((char *, int));
119 int	 dump_exists __P((void));
120 char	*find_dev __P((dev_t, int));
121 int	 get_crashtime __P((void));
122 void	 kmem_setup __P((void));
123 void	 log __P((int, char *, ...));
124 void	 Lseek __P((int, off_t, int));
125 int	 Open __P((const char *, int rw));
126 int	 Read __P((int, void *, int));
127 char	*rawname __P((char *s));
128 void	 save_core __P((void));
129 void	 usage __P((void));
130 void	 Write __P((int, void *, int));
131 
132 int
133 main(argc, argv)
134 	int argc;
135 	char *argv[];
136 {
137 	int ch;
138 
139 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
140 
141 	while ((ch = getopt(argc, argv, "cdfN:vz")) != EOF)
142 		switch(ch) {
143 		case 'c':
144 			clear = 1;
145 			break;
146 		case 'd':		/* Not documented. */
147 		case 'v':
148 			verbose = 1;
149 			break;
150 		case 'f':
151 			force = 1;
152 			break;
153 		case 'N':
154 			kernel = optarg;
155 			break;
156 		case 'z':
157 			compress = 1;
158 			break;
159 		case '?':
160 		default:
161 			usage();
162 		}
163 	argc -= optind;
164 	argv += optind;
165 
166 	if (!clear) {
167 		if (argc != 1 && argc != 2)
168 			usage();
169 		dirname = argv[0];
170 	}
171 	if (argc == 2)
172 		kernel = argv[1];
173 
174 	(void)time(&now);
175 	kmem_setup();
176 
177 	if (clear) {
178 		clear_dump();
179 		exit(0);
180 	}
181 
182 	if (!dump_exists() && !force)
183 		exit(1);
184 
185 	check_kmem();
186 
187 	if (panicstr)
188 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
189 	else
190 		syslog(LOG_ALERT, "reboot");
191 
192 	if ((!get_crashtime() || !check_space()) && !force)
193 		exit(1);
194 
195 	save_core();
196 
197 	clear_dump();
198 	exit(0);
199 }
200 
201 void
202 kmem_setup()
203 {
204 	FILE *fp;
205 	int kmem, i;
206 	const char *dump_sys;
207 
208 	/*
209 	 * Some names we need for the currently running system, others for
210 	 * the system that was running when the dump was made.  The values
211 	 * obtained from the current system are used to look for things in
212 	 * /dev/kmem that cannot be found in the dump_sys namelist, but are
213 	 * presumed to be the same (since the disk partitions are probably
214 	 * the same!)
215 	 */
216 	if ((nlist(getbootfile(), current_nl)) == -1)
217 		syslog(LOG_ERR, "%s: nlist: %s", getbootfile(),
218 		       strerror(errno));
219 	for (i = 0; cursyms[i] != -1; i++)
220 		if (current_nl[cursyms[i]].n_value == 0) {
221 			syslog(LOG_ERR, "%s: %s not in namelist",
222 			    getbootfile(), current_nl[cursyms[i]].n_name);
223 			exit(1);
224 		}
225 
226 	dump_sys = kernel ? kernel : getbootfile();
227 	if ((nlist(dump_sys, dump_nl)) == -1)
228 		syslog(LOG_ERR, "%s: nlist: %s", dump_sys, strerror(errno));
229 	for (i = 0; dumpsyms[i] != -1; i++)
230 		if (dump_nl[dumpsyms[i]].n_value == 0) {
231 			syslog(LOG_ERR, "%s: %s not in namelist",
232 			    dump_sys, dump_nl[dumpsyms[i]].n_name);
233 			exit(1);
234 		}
235 
236 	kmem = Open(_PATH_KMEM, O_RDONLY);
237 	Lseek(kmem, (off_t)current_nl[X_DUMPDEV].n_value, L_SET);
238 	(void)Read(kmem, &dumpdev, sizeof(dumpdev));
239 	if (dumpdev == NODEV) {
240 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
241 		exit(1);
242 	}
243 	Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET);
244 	(void)Read(kmem, &dumplo, sizeof(dumplo));
245 	if (verbose)
246 		(void)printf("dumplo = %d (%d * %d)\n",
247 		    dumplo, dumplo/DEV_BSIZE, DEV_BSIZE);
248 	Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET);
249 	(void)Read(kmem, &dumpmag, sizeof(dumpmag));
250 	dumplo *= DEV_BSIZE;
251 	ddname = find_dev(dumpdev, S_IFBLK);
252 	dumpfd = Open(ddname, O_RDWR);
253 	fp = fdopen(kmem, "r");
254 	if (fp == NULL) {
255 		syslog(LOG_ERR, "%s: fdopen: %m", _PATH_KMEM);
256 		exit(1);
257 	}
258 	if (kernel)
259 		return;
260 	(void)fseek(fp, (off_t)current_nl[X_VERSION].n_value, L_SET);
261 	(void)fgets(vers, sizeof(vers), fp);
262 
263 	/* Don't fclose(fp), we use dumpfd later. */
264 }
265 
266 void
267 check_kmem()
268 {
269 	register char *cp;
270 	FILE *fp;
271 	char core_vers[1024];
272 
273 	fp = fdopen(dumpfd, "r");
274 	if (fp == NULL) {
275 		syslog(LOG_ERR, "%s: fdopen: %m", ddname);
276 		exit(1);
277 	}
278 	fseek(fp, (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET);
279 	fgets(core_vers, sizeof(core_vers), fp);
280 	if (strcmp(vers, core_vers) && kernel == 0)
281 		syslog(LOG_WARNING,
282 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
283 		    getbootfile(), vers, core_vers);
284 	(void)fseek(fp,
285 	    (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET);
286 	(void)fread(&panicstr, sizeof(panicstr), 1, fp);
287 	if (panicstr) {
288 		(void)fseek(fp, dumplo + ok(panicstr), L_SET);
289 		cp = panic_mesg;
290 		do
291 			*cp = getc(fp);
292 		while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)]);
293 	}
294 	/* Don't fclose(fp), we use dumpfd later. */
295 }
296 
297 void
298 clear_dump()
299 {
300 	long newdumplo;
301 
302 	newdumplo = 0;
303 	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
304 	Write(dumpfd, &newdumplo, sizeof(newdumplo));
305 }
306 
307 int
308 dump_exists()
309 {
310 	int newdumpmag;
311 
312 	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
313 	(void)Read(dumpfd, &newdumpmag, sizeof(newdumpmag));
314 	if (newdumpmag != dumpmag) {
315 		if (verbose)
316 			syslog(LOG_WARNING, "magic number mismatch (%x != %x)",
317 			    newdumpmag, dumpmag);
318 		syslog(LOG_WARNING, "no core dump");
319 		return (0);
320 	}
321 	return (1);
322 }
323 
324 char buf[1024 * 1024];
325 
326 void
327 save_core()
328 {
329 	register FILE *fp;
330 	register int bounds, ifd, nr, nw, ofd;
331 	char *rawp, path[MAXPATHLEN];
332 
333 	/*
334 	 * Get the current number and update the bounds file.  Do the update
335 	 * now, because may fail later and don't want to overwrite anything.
336 	 */
337 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
338 	if ((fp = fopen(path, "r")) == NULL)
339 		goto err1;
340 	if (fgets(buf, sizeof(buf), fp) == NULL) {
341 		if (ferror(fp))
342 err1:			syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
343 		bounds = 0;
344 	} else
345 		bounds = atoi(buf);
346 	if (fp != NULL)
347 		(void)fclose(fp);
348 	if ((fp = fopen(path, "w")) == NULL)
349 		syslog(LOG_ERR, "%s: %m", path);
350 	else {
351 		(void)fprintf(fp, "%d\n", bounds + 1);
352 		(void)fclose(fp);
353 	}
354 
355 	/* Create the core file. */
356 	(void)snprintf(path, sizeof(path), "%s/vmcore.%d%s",
357 	    dirname, bounds, compress ? ".Z" : "");
358 	if (compress) {
359 		if ((fp = zopen(path, "w", 0)) == NULL) {
360 			syslog(LOG_ERR, "%s: %s", path, strerror(errno));
361 			exit(1);
362 		}
363 	} else
364 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
365 
366 	/* Open the raw device. */
367 	rawp = rawname(ddname);
368 	if ((ifd = open(rawp, O_RDONLY)) == -1) {
369 		syslog(LOG_WARNING, "%s: %m; using block device", rawp);
370 		ifd = dumpfd;
371 	}
372 
373 	/* Read the dump size. */
374 	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET);
375 	(void)Read(dumpfd, &dumpsize, sizeof(dumpsize));
376 
377 	/* Seek to the start of the core. */
378 	Lseek(ifd, (off_t)dumplo, L_SET);
379 
380 	/* Copy the core file. */
381 	dumpsize *= getpagesize();
382 	syslog(LOG_NOTICE, "writing %score to %s",
383 	    compress ? "compressed " : "", path);
384 	for (; dumpsize > 0; dumpsize -= nr) {
385 		(void)printf("%6dK\r", dumpsize / 1024);
386 		(void)fflush(stdout);
387 		nr = read(ifd, buf, MIN(dumpsize, sizeof(buf)));
388 		if (nr <= 0) {
389 			if (nr == 0)
390 				syslog(LOG_WARNING,
391 				    "WARNING: EOF on dump device");
392 			else
393 				syslog(LOG_ERR, "%s: %m", rawp);
394 			goto err2;
395 		}
396 		if (compress)
397 			nw = fwrite(buf, 1, nr, fp);
398 		else
399 			nw = write(ofd, buf, nr);
400 		if (nw != nr) {
401 			syslog(LOG_ERR, "%s: %s",
402 			    path, strerror(nw == 0 ? EIO : errno));
403 err2:			syslog(LOG_WARNING,
404 			    "WARNING: vmcore may be incomplete");
405 			(void)printf("\n");
406 			exit(1);
407 		}
408 	}
409 	(void)close(ifd);
410 	if (compress)
411 		(void)fclose(fp);
412 	else
413 		(void)close(ofd);
414 
415 	/* Copy the kernel. */
416 	ifd = Open(kernel ? kernel : getbootfile(), O_RDONLY);
417 	(void)snprintf(path, sizeof(path), "%s/kernel.%d%s",
418 	    dirname, bounds, compress ? ".Z" : "");
419 	if (compress) {
420 		if ((fp = zopen(path, "w", 0)) == NULL) {
421 			syslog(LOG_ERR, "%s: %s", path, strerror(errno));
422 			exit(1);
423 		}
424 	} else
425 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
426 	syslog(LOG_NOTICE, "writing %skernel to %s",
427 	    compress ? "compressed " : "", path);
428 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
429 		if (compress)
430 			nw = fwrite(buf, 1, nr, fp);
431 		else
432 			nw = write(ofd, buf, nr);
433 		if (nw != nr) {
434 			syslog(LOG_ERR, "%s: %s",
435 			    path, strerror(nw == 0 ? EIO : errno));
436 			syslog(LOG_WARNING,
437 			    "WARNING: kernel may be incomplete");
438 			exit(1);
439 		}
440 	}
441 	if (nr < 0) {
442 		syslog(LOG_ERR, "%s: %s",
443 		    kernel ? kernel : getbootfile(), strerror(errno));
444 		syslog(LOG_WARNING,
445 		    "WARNING: kernel may be incomplete");
446 		exit(1);
447 	}
448 	if (compress)
449 		(void)fclose(fp);
450 	else
451 		(void)close(ofd);
452 }
453 
454 char *
455 find_dev(dev, type)
456 	register dev_t dev;
457 	register int type;
458 {
459 	register DIR *dfd;
460 	struct dirent *dir;
461 	struct stat sb;
462 	char *dp, devname[MAXPATHLEN + 1];
463 
464 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
465 		syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno));
466 		exit(1);
467 	}
468 	(void)strcpy(devname, _PATH_DEV);
469 	while ((dir = readdir(dfd))) {
470 		(void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name);
471 		if (lstat(devname, &sb)) {
472 			syslog(LOG_ERR, "%s: %s", devname, strerror(errno));
473 			continue;
474 		}
475 		if ((sb.st_mode & S_IFMT) != type)
476 			continue;
477 		if (dev == sb.st_rdev) {
478 			closedir(dfd);
479 			if ((dp = strdup(devname)) == NULL) {
480 				syslog(LOG_ERR, "%s", strerror(errno));
481 				exit(1);
482 			}
483 			return (dp);
484 		}
485 	}
486 	closedir(dfd);
487 	syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
488 	exit(1);
489 }
490 
491 char *
492 rawname(s)
493 	char *s;
494 {
495 	char *sl, name[MAXPATHLEN];
496 
497 	if ((sl = rindex(s, '/')) == NULL || sl[1] == '0') {
498 		syslog(LOG_ERR,
499 		    "can't make raw dump device name from %s", s);
500 		return (s);
501 	}
502 	(void)snprintf(name, sizeof(name), "%.*s/r%s", sl - s, s, sl + 1);
503 	if ((sl = strdup(name)) == NULL) {
504 		syslog(LOG_ERR, "%s", strerror(errno));
505 		exit(1);
506 	}
507 	return (sl);
508 }
509 
510 int
511 get_crashtime()
512 {
513 	time_t dumptime;			/* Time the dump was taken. */
514 
515 	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET);
516 	(void)Read(dumpfd, &dumptime, sizeof(dumptime));
517 	if (dumptime == 0) {
518 		if (verbose)
519 			syslog(LOG_ERR, "dump time is zero");
520 		return (0);
521 	}
522 	(void)printf("savecore: system went down at %s", ctime(&dumptime));
523 #define	LEEWAY	(7 * 86400)
524 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
525 		(void)printf("dump time is unreasonable\n");
526 		return (0);
527 	}
528 	return (1);
529 }
530 
531 int
532 check_space()
533 {
534 	register FILE *fp;
535 	const char *tkernel;
536 	off_t minfree, spacefree, kernelsize, needed;
537 	struct stat st;
538 	struct statfs fsbuf;
539 	char buf[100], path[MAXPATHLEN];
540 
541 	tkernel = kernel ? kernel : getbootfile();
542 	if (stat(tkernel, &st) < 0) {
543 		syslog(LOG_ERR, "%s: %m", tkernel);
544 		exit(1);
545 	}
546 	kernelsize = st.st_blocks * S_BLKSIZE;
547 	if (statfs(dirname, &fsbuf) < 0) {
548 		syslog(LOG_ERR, "%s: %m", dirname);
549 		exit(1);
550 	}
551  	spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
552 
553 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
554 	if ((fp = fopen(path, "r")) == NULL)
555 		minfree = 0;
556 	else {
557 		if (fgets(buf, sizeof(buf), fp) == NULL)
558 			minfree = 0;
559 		else
560 			minfree = atoi(buf);
561 		(void)fclose(fp);
562 	}
563 
564 	needed = (dumpsize + kernelsize) / 1024;
565  	if (minfree > 0 && spacefree - needed < minfree) {
566 		syslog(LOG_WARNING,
567 		    "no dump, not enough free space on device");
568 		return (0);
569 	}
570 	if (spacefree - needed < minfree)
571 		syslog(LOG_WARNING,
572 		    "dump performed, but free space threshold crossed");
573 	return (1);
574 }
575 
576 int
577 Open(name, rw)
578 	const char *name;
579 	int rw;
580 {
581 	int fd;
582 
583 	if ((fd = open(name, rw, 0)) < 0) {
584 		syslog(LOG_ERR, "%s: %m", name);
585 		exit(1);
586 	}
587 	return (fd);
588 }
589 
590 int
591 Read(fd, bp, size)
592 	int fd, size;
593 	void *bp;
594 {
595 	int nr;
596 
597 	nr = read(fd, bp, size);
598 	if (nr != size) {
599 		syslog(LOG_ERR, "read: %m");
600 		exit(1);
601 	}
602 	return (nr);
603 }
604 
605 void
606 Lseek(fd, off, flag)
607 	int fd, flag;
608 	off_t off;
609 {
610 	off_t ret;
611 
612 	ret = lseek(fd, off, flag);
613 	if (ret == -1) {
614 		syslog(LOG_ERR, "lseek: %m");
615 		exit(1);
616 	}
617 }
618 
619 int
620 Create(file, mode)
621 	char *file;
622 	int mode;
623 {
624 	register int fd;
625 
626 	fd = creat(file, mode);
627 	if (fd < 0) {
628 		syslog(LOG_ERR, "%s: %m", file);
629 		exit(1);
630 	}
631 	return (fd);
632 }
633 
634 void
635 Write(fd, bp, size)
636 	int fd, size;
637 	void *bp;
638 {
639 	int n;
640 
641 	if ((n = write(fd, bp, size)) < size) {
642 		syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
643 		exit(1);
644 	}
645 }
646 
647 void
648 usage()
649 {
650 	(void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory");
651 	exit(1);
652 }
653