1 /*-
2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7 * and NAI Labs, the Security Research Division of Network Associates, Inc.
8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9 * DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. The names of the authors may not be used to endorse or promote
20 * products derived from this software without specific prior written
21 * permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * Copyright (c) 1986, 1992, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 */
62
63 #include <sys/param.h>
64 #include <sys/kerneldump.h>
65 #include <sys/diskslice.h>
66 #include <sys/ioctl.h>
67 #include <sys/mount.h>
68 #include <sys/stat.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <fstab.h>
72 #include <paths.h>
73 #include <stdarg.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <syslog.h>
78 #include <time.h>
79 #include <unistd.h>
80
81 /* The size of the buffer used for I/O. */
82 #define BUFFERSIZE (1024*1024)
83
84 #define STATUS_BAD 0
85 #define STATUS_GOOD 1
86 #define STATUS_UNKNOWN 2
87
88 static int checkfor, compress, clear, force, keep, verbose; /* flags */
89 static int nfound, nsaved, nerr; /* statistics */
90
91 extern FILE *zopen(const char *, const char *);
92
93 static void
printheader(FILE * f,const struct kerneldumpheader * h,const char * device,int bounds,const int status)94 printheader(FILE *f, const struct kerneldumpheader *h, const char *device,
95 int bounds, const int status)
96 {
97 uint64_t dumplen;
98 time_t t;
99 const char *stat_str;
100
101 fprintf(f, "Dump header from device %s\n", device);
102 fprintf(f, " Architecture: %s\n", h->architecture);
103 fprintf(f, " Architecture Version: %u\n",
104 dtoh32(h->architectureversion));
105 dumplen = dtoh64(h->dumplength);
106 fprintf(f, " Dump Length: %lldB (%lld MB)\n", (long long)dumplen,
107 (long long)(dumplen >> 20));
108 fprintf(f, " Blocksize: %d\n", dtoh32(h->blocksize));
109 t = dtoh64(h->dumptime);
110 fprintf(f, " Dumptime: %s", ctime(&t));
111 fprintf(f, " Hostname: %s\n", h->hostname);
112 fprintf(f, " Magic: %s\n", h->magic);
113 fprintf(f, " Version String: %s", h->versionstring);
114 fprintf(f, " Panic String: %s\n", h->panicstring);
115 fprintf(f, " Dump Parity: %u\n", h->parity);
116 fprintf(f, " Bounds: %d\n", bounds);
117
118 switch(status) {
119 case STATUS_BAD:
120 stat_str = "bad";
121 break;
122 case STATUS_GOOD:
123 stat_str = "good";
124 break;
125 default:
126 stat_str = "unknown";
127 }
128 fprintf(f, " Dump Status: %s\n", stat_str);
129 fflush(f);
130 }
131
132 static int
getbounds(void)133 getbounds(void) {
134 FILE *fp;
135 char buf[6];
136 int ret;
137
138 ret = 0;
139
140 if ((fp = fopen("bounds", "r")) == NULL) {
141 if (verbose)
142 printf("unable to open bounds file, using 0\n");
143 return (ret);
144 }
145
146 if (fgets(buf, sizeof buf, fp) == NULL) {
147 syslog(LOG_WARNING, "unable to read from bounds, using 0");
148 fclose(fp);
149 return (ret);
150 }
151
152 errno = 0;
153 ret = (int)strtol(buf, NULL, 10);
154 if (ret == 0 && (errno == EINVAL || errno == ERANGE))
155 syslog(LOG_WARNING, "invalid value found in bounds, using 0");
156 fclose(fp);
157 return (ret);
158 }
159
160 static void
writebounds(int bounds)161 writebounds(int bounds) {
162 FILE *fp;
163
164 if ((fp = fopen("bounds", "w")) == NULL) {
165 syslog(LOG_WARNING, "unable to write to bounds file: %m");
166 return;
167 }
168
169 if (verbose)
170 printf("bounds number: %d\n", bounds);
171
172 fprintf(fp, "%d\n", bounds);
173 fclose(fp);
174 }
175
176 /*
177 * Check that sufficient space is available on the disk that holds the
178 * save directory.
179 */
180 static int
check_space(const char * savedir,off_t dumpsize)181 check_space(const char *savedir, off_t dumpsize)
182 {
183 FILE *fp;
184 off_t minfree, spacefree, totfree, needed;
185 struct statfs fsbuf;
186 char buf[100], path[MAXPATHLEN];
187
188 if (statfs(savedir, &fsbuf) < 0) {
189 syslog(LOG_ERR, "%s: %m", savedir);
190 exit(1);
191 }
192 spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
193 totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
194
195 (void)snprintf(path, sizeof(path), "%s/minfree", savedir);
196 if ((fp = fopen(path, "r")) == NULL)
197 minfree = 0;
198 else {
199 if (fgets(buf, sizeof(buf), fp) == NULL)
200 minfree = 0;
201 else
202 minfree = atoi(buf);
203 (void)fclose(fp);
204 }
205
206 needed = dumpsize / 1024 + 2; /* 2 for info file */
207 if (((minfree > 0) ? spacefree : totfree) - needed < minfree) {
208 syslog(LOG_WARNING,
209 "no dump, not enough free space on device (%lld available, need %lld)",
210 (long long)(minfree > 0 ? spacefree : totfree),
211 (long long)needed);
212 return (0);
213 }
214 if (spacefree - needed < 0)
215 syslog(LOG_WARNING,
216 "dump performed, but free space threshold crossed");
217 return (1);
218 }
219
220 #define BLOCKSIZE (1<<12)
221 #define BLOCKMASK (~(BLOCKSIZE-1))
222
223 static void
DoFile(const char * savedir,const char * device)224 DoFile(const char *savedir, const char *device)
225 {
226 static char *buf = NULL;
227 struct partinfo dpart;
228 struct kerneldumpheader kdhf, kdhl;
229 off_t mediasize, dumpsize, firsthd, lasthd, dmpcnt;
230 FILE *info, *fp, *fpkern;
231 mode_t oumask;
232 int fd, fdinfo, fdkernin, error, wl;
233 int nr, nw, hs, he = 0;
234 int bounds, status;
235 u_int sectorsize;
236
237 bounds = getbounds();
238 dmpcnt = 0;
239 mediasize = 0;
240 status = STATUS_UNKNOWN;
241
242 if (buf == NULL) {
243 buf = malloc(BUFFERSIZE);
244 if (buf == NULL) {
245 syslog(LOG_ERR, "%m");
246 return;
247 }
248 }
249
250 if (verbose)
251 printf("checking for kernel dump on device %s\n", device);
252
253 fd = open(device, O_RDWR);
254 if (fd < 0) {
255 syslog(LOG_ERR, "%s: %m", device);
256 return;
257 }
258
259 bzero(&dpart, sizeof(dpart));
260 error = ioctl(fd, DIOCGPART, &dpart);
261 if (error) {
262 syslog(LOG_ERR,
263 "couldn't find media and/or sector size of %s: %m", device);
264 goto closefd;
265 }
266 mediasize = dpart.media_size;
267 sectorsize = dpart.media_blksize;
268
269 if (verbose) {
270 printf("mediasize = %lld\n", (long long)mediasize);
271 printf("sectorsize = %u\n", sectorsize);
272 }
273
274 lasthd = mediasize - sectorsize;
275 lseek(fd, lasthd, SEEK_SET);
276 error = read(fd, &kdhl, sizeof kdhl);
277 if (error != sizeof kdhl) {
278 syslog(LOG_ERR,
279 "error reading last dump header at offset %lld in %s: %m",
280 (long long)lasthd, device);
281 goto closefd;
282 }
283 if (memcmp(kdhl.magic, KERNELDUMPMAGIC, sizeof kdhl.magic)) {
284 if (verbose)
285 printf("magic mismatch on last dump header on %s\n",
286 device);
287
288 status = STATUS_BAD;
289 if (force == 0)
290 goto closefd;
291
292 if (memcmp(kdhl.magic, KERNELDUMPMAGIC_CLEARED,
293 sizeof kdhl.magic) == 0) {
294 if (verbose)
295 printf("forcing magic on %s\n", device);
296 memcpy(kdhl.magic, KERNELDUMPMAGIC,
297 sizeof kdhl.magic);
298 } else {
299 syslog(LOG_ERR, "unable to force dump - bad magic");
300 goto closefd;
301 }
302 }
303 if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
304 syslog(LOG_ERR,
305 "unknown version (%d) in last dump header on %s",
306 dtoh32(kdhl.version), device);
307
308 status = STATUS_BAD;
309 if (force == 0)
310 goto closefd;
311 }
312
313 nfound++;
314 if (clear)
315 goto nuke;
316
317 if (kerneldump_parity(&kdhl)) {
318 syslog(LOG_ERR,
319 "parity error on last dump header on %s", device);
320 nerr++;
321 status = STATUS_BAD;
322 if (force == 0)
323 goto closefd;
324 }
325 dumpsize = dtoh64(kdhl.dumplength);
326 firsthd = lasthd - dumpsize - sizeof kdhf;
327 lseek(fd, firsthd, SEEK_SET);
328 error = read(fd, &kdhf, sizeof kdhf);
329 if (error != sizeof kdhf) {
330 syslog(LOG_ERR,
331 "error reading first dump header at offset %lld in %s: %m",
332 (long long)firsthd, device);
333 nerr++;
334 goto closefd;
335 }
336
337 if (verbose >= 2) {
338 printf("First dump headers:\n");
339 printheader(stdout, &kdhf, device, bounds, -1);
340
341 printf("\nLast dump headers:\n");
342 printheader(stdout, &kdhl, device, bounds, -1);
343 printf("\n");
344 }
345
346 if (memcmp(&kdhl, &kdhf, sizeof kdhl)) {
347 syslog(LOG_ERR,
348 "first and last dump headers disagree on %s", device);
349 nerr++;
350 status = STATUS_BAD;
351 if (force == 0)
352 goto closefd;
353 } else {
354 status = STATUS_GOOD;
355 }
356
357 if (checkfor) {
358 printf("A dump exists on %s\n", device);
359 close(fd);
360 exit(0);
361 }
362
363 if (kdhl.panicstring[0])
364 syslog(LOG_ALERT, "reboot after panic: %s", kdhl.panicstring);
365 else
366 syslog(LOG_ALERT, "reboot");
367
368 if (verbose)
369 printf("Checking for available free space\n");
370 if (!check_space(savedir, dumpsize)) {
371 nerr++;
372 goto closefd;
373 }
374
375 writebounds(bounds + 1);
376
377 /*
378 * Write kernel file.
379 */
380 fdkernin = open(getbootfile(), O_RDONLY, 0);
381 if (fdkernin < 0) {
382 syslog(LOG_ERR, "%s: %m", getbootfile());
383 }
384
385 if (compress) {
386 sprintf(buf, "kern.%d.gz", bounds);
387 fpkern = zopen(buf, "w");
388 } else {
389 sprintf(buf, "kern.%d", bounds);
390 fpkern = fopen(buf, "w");
391 }
392 if (fpkern == NULL) {
393 syslog(LOG_ERR, "%s: %m", buf);
394 close(fdkernin);
395 }
396
397 syslog(LOG_NOTICE, "writing %skernel to %s",
398 compress ? "compressed " : "", buf);
399
400 while ((nr = read(fdkernin, buf, BUFFERSIZE)) > 0) {
401 nw = fwrite(buf, 1, nr, fpkern);
402 if (nw != nr) {
403 syslog(LOG_ERR, "kern.%d: %m", bounds);
404 syslog(LOG_WARNING,
405 "WARNING: kernel may be incomplete");
406 exit(1);
407 }
408 }
409 if (nr < 0) {
410 syslog(LOG_ERR, "%s: %m", getbootfile());
411 syslog(LOG_WARNING,
412 "WARNING: kernel may be incomplete");
413 exit(1);
414 }
415 fclose(fpkern);
416 close(fdkernin);
417
418
419 sprintf(buf, "info.%d", bounds);
420
421 /*
422 * Create or overwrite any existing dump header files.
423 */
424 fdinfo = open(buf, O_WRONLY | O_CREAT | O_TRUNC, 0600);
425 if (fdinfo < 0) {
426 syslog(LOG_ERR, "%s: %m", buf);
427 nerr++;
428 goto closefd;
429 }
430 oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
431 if (compress) {
432 sprintf(buf, "vmcore.%d.gz", bounds);
433 fp = zopen(buf, "w");
434 } else {
435 sprintf(buf, "vmcore.%d", bounds);
436 fp = fopen(buf, "w");
437 }
438 if (fp == NULL) {
439 syslog(LOG_ERR, "%s: %m", buf);
440 close(fdinfo);
441 nerr++;
442 goto closefd;
443 }
444 (void)umask(oumask);
445
446 info = fdopen(fdinfo, "w");
447
448 if (info == NULL) {
449 syslog(LOG_ERR, "fdopen failed: %m");
450 nerr++;
451 goto closefd;
452 }
453
454 if (verbose)
455 printheader(stdout, &kdhl, device, bounds, status);
456
457 printheader(info, &kdhl, device, bounds, status);
458 fclose(info);
459
460 syslog(LOG_NOTICE, "writing %score to %s",
461 compress ? "compressed " : "", buf);
462
463 while (dumpsize > 0) {
464 wl = BUFFERSIZE;
465 if (wl > dumpsize)
466 wl = dumpsize;
467 nr = read(fd, buf, wl);
468 if (nr != wl) {
469 if (nr == 0)
470 syslog(LOG_WARNING,
471 "WARNING: EOF on dump device");
472 else
473 syslog(LOG_ERR, "read error on %s: %m", device);
474 nerr++;
475 goto closeall;
476 }
477 if (compress) {
478 nw = fwrite(buf, 1, wl, fp);
479 } else {
480 for (nw = 0; nw < nr; nw = he) {
481 /* find a contiguous block of zeroes */
482 for (hs = nw; hs < nr; hs += BLOCKSIZE) {
483 for (he = hs; he < nr && buf[he] == 0;
484 ++he)
485 /* nothing */ ;
486 /* is the hole long enough to matter? */
487 if (he >= hs + BLOCKSIZE)
488 break;
489 }
490
491 /* back down to a block boundary */
492 he &= BLOCKMASK;
493
494 /*
495 * 1) Don't go beyond the end of the buffer.
496 * 2) If the end of the buffer is less than
497 * BLOCKSIZE bytes away, we're at the end
498 * of the file, so just grab what's left.
499 */
500 if (hs + BLOCKSIZE > nr)
501 hs = he = nr;
502
503 /*
504 * At this point, we have a partial ordering:
505 * nw <= hs <= he <= nr
506 * If hs > nw, buf[nw..hs] contains non-zero data.
507 * If he > hs, buf[hs..he] is all zeroes.
508 */
509 if (hs > nw)
510 if (fwrite(buf + nw, hs - nw, 1, fp)
511 != 1)
512 break;
513 if (he > hs)
514 if (fseeko(fp, he - hs, SEEK_CUR) == -1)
515 break;
516 }
517 }
518 if (nw != wl) {
519 syslog(LOG_ERR,
520 "write error on vmcore.%d file: %m", bounds);
521 syslog(LOG_WARNING,
522 "WARNING: vmcore may be incomplete");
523 nerr++;
524 goto closeall;
525 }
526 if (verbose) {
527 dmpcnt += wl;
528 printf("%llu\r", (unsigned long long)dmpcnt);
529 fflush(stdout);
530 }
531 dumpsize -= wl;
532 }
533 if (verbose)
534 printf("\n");
535
536 if (fclose(fp) < 0) {
537 syslog(LOG_ERR, "error on vmcore.%d: %m", bounds);
538 nerr++;
539 goto closeall;
540 }
541 nsaved++;
542
543 if (verbose)
544 printf("dump saved\n");
545
546 nuke:
547 if (clear || !keep) {
548 if (verbose)
549 printf("clearing dump header\n");
550 memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof kdhl.magic);
551 lseek(fd, lasthd, SEEK_SET);
552 error = write(fd, &kdhl, sizeof kdhl);
553 if (error != sizeof kdhl)
554 syslog(LOG_ERR,
555 "error while clearing the dump header: %m");
556 }
557 close(fd);
558 return;
559
560 closeall:
561 fclose(fp);
562
563 closefd:
564 close(fd);
565 }
566
567 static void
usage(void)568 usage(void)
569 {
570 fprintf(stderr, "%s\n%s\n%s\n",
571 "usage: savecore -c",
572 " savecore -C [-v] [directory device]",
573 " savecore [-fkvz] [directory [device ...]]");
574 exit (1);
575 }
576
577 int
main(int argc,char ** argv)578 main(int argc, char **argv)
579 {
580 const char *savedir = ".";
581 struct fstab *fsp;
582 int i, ch, error;
583
584 checkfor = compress = clear = force = keep = verbose = 0;
585 nfound = nsaved = nerr = 0;
586
587 openlog("savecore", LOG_PERROR, LOG_DAEMON);
588
589 while ((ch = getopt(argc, argv, "Ccfkvz")) != -1)
590 switch(ch) {
591 case 'C':
592 checkfor = 1;
593 break;
594 case 'c':
595 clear = 1;
596 break;
597 case 'k':
598 keep = 1;
599 break;
600 case 'v':
601 verbose++;
602 break;
603 case 'f':
604 force = 1;
605 break;
606 case 'z':
607 compress = 1;
608 break;
609 case '?':
610 default:
611 usage();
612 }
613 if (checkfor && (clear || force || keep))
614 usage();
615 argc -= optind;
616 argv += optind;
617 if (argc >= 1) {
618 error = chdir(argv[0]);
619 if (error) {
620 syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
621 exit(1);
622 }
623 savedir = argv[0];
624 argc--;
625 argv++;
626 }
627 if (argc == 0) {
628 for (;;) {
629 fsp = getfsent();
630 if (fsp == NULL)
631 break;
632 if (strcmp(fsp->fs_vfstype, "swap") &&
633 strcmp(fsp->fs_vfstype, "dump"))
634 continue;
635 DoFile(savedir, fsp->fs_spec);
636 }
637 } else {
638 for (i = 0; i < argc; i++)
639 DoFile(savedir, argv[i]);
640 }
641
642 /* Emit minimal output. */
643 if (nfound == 0) {
644 if (checkfor) {
645 printf("No dump exists\n");
646 exit(1);
647 }
648 syslog(LOG_WARNING, "no dumps found");
649 }
650 else if (nsaved == 0) {
651 if (nerr != 0)
652 syslog(LOG_WARNING, "unsaved dumps found but not saved");
653 else
654 syslog(LOG_WARNING, "no unsaved dumps found");
655 }
656
657 return (0);
658 }
659