savecore.c revision 150818
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. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 */ 66 67#include <sys/cdefs.h> 68__FBSDID("$FreeBSD: head/sbin/savecore/savecore.c 150818 2005-10-02 11:31:45Z maxim $"); 69 70#include <sys/param.h> 71#include <sys/disk.h> 72#include <sys/kerneldump.h> 73#include <sys/param.h> 74#include <sys/mount.h> 75#include <sys/stat.h> 76#include <errno.h> 77#include <fcntl.h> 78#include <fstab.h> 79#include <paths.h> 80#include <stdarg.h> 81#include <stdio.h> 82#include <stdlib.h> 83#include <string.h> 84#include <syslog.h> 85#include <time.h> 86#include <unistd.h> 87 88/* The size of the buffer used for I/O. */ 89#define BUFFERSIZE (1024*1024) 90 91#define STATUS_BAD 0 92#define STATUS_GOOD 1 93#define STATUS_UNKNOWN 2 94 95static int checkfor, compress, clear, force, keep, verbose; /* flags */ 96static int nfound, nsaved, nerr; /* statistics */ 97 98extern FILE *zopen(const char *, const char *); 99 100static void 101printheader(FILE *f, const struct kerneldumpheader *h, const char *device, 102 int bounds, const int status) 103{ 104 uint64_t dumplen; 105 time_t t; 106 const char *stat_str; 107 108 fprintf(f, "Dump header from device %s\n", device); 109 fprintf(f, " Architecture: %s\n", h->architecture); 110 fprintf(f, " Architecture Version: %u\n", 111 dtoh32(h->architectureversion)); 112 dumplen = dtoh64(h->dumplength); 113 fprintf(f, " Dump Length: %lldB (%lld MB)\n", (long long)dumplen, 114 (long long)(dumplen >> 20)); 115 fprintf(f, " Blocksize: %d\n", dtoh32(h->blocksize)); 116 t = dtoh64(h->dumptime); 117 fprintf(f, " Dumptime: %s", ctime(&t)); 118 fprintf(f, " Hostname: %s\n", h->hostname); 119 fprintf(f, " Magic: %s\n", h->magic); 120 fprintf(f, " Version String: %s", h->versionstring); 121 fprintf(f, " Panic String: %s\n", h->panicstring); 122 fprintf(f, " Dump Parity: %u\n", h->parity); 123 fprintf(f, " Bounds: %d\n", bounds); 124 125 switch(status) { 126 case STATUS_BAD: 127 stat_str = "bad"; 128 break; 129 case STATUS_GOOD: 130 stat_str = "good"; 131 break; 132 default: 133 stat_str = "unknown"; 134 } 135 fprintf(f, " Dump Status: %s\n", stat_str); 136 fflush(f); 137} 138 139static int 140getbounds(void) { 141 FILE *fp; 142 char buf[6]; 143 int ret; 144 145 ret = 0; 146 147 if ((fp = fopen("bounds", "r")) == NULL) { 148 if (verbose) 149 printf("unable to open bounds file, using 0\n"); 150 return (ret); 151 } 152 153 if (fgets(buf, sizeof buf, fp) == NULL) { 154 syslog(LOG_WARNING, "unable to read from bounds, using 0"); 155 fclose(fp); 156 return (ret); 157 } 158 159 errno = 0; 160 ret = (int)strtol(buf, NULL, 10); 161 if (ret == 0 && (errno == EINVAL || errno == ERANGE)) 162 syslog(LOG_WARNING, "invalid value found in bounds, using 0"); 163 return (ret); 164} 165 166static void 167writebounds(int bounds) { 168 FILE *fp; 169 170 if ((fp = fopen("bounds", "w")) == NULL) { 171 syslog(LOG_WARNING, "unable to write to bounds file: %m"); 172 return; 173 } 174 175 if (verbose) 176 printf("bounds number: %d\n", bounds); 177 178 fprintf(fp, "%d\n", bounds); 179 fclose(fp); 180} 181 182/* 183 * Check that sufficient space is available on the disk that holds the 184 * save directory. 185 */ 186static int 187check_space(const char *savedir, off_t dumpsize) 188{ 189 FILE *fp; 190 off_t minfree, spacefree, totfree, needed; 191 struct statfs fsbuf; 192 char buf[100], path[MAXPATHLEN]; 193 194 if (statfs(savedir, &fsbuf) < 0) { 195 syslog(LOG_ERR, "%s: %m", savedir); 196 exit(1); 197 } 198 spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024; 199 totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024; 200 201 (void)snprintf(path, sizeof(path), "%s/minfree", savedir); 202 if ((fp = fopen(path, "r")) == NULL) 203 minfree = 0; 204 else { 205 if (fgets(buf, sizeof(buf), fp) == NULL) 206 minfree = 0; 207 else 208 minfree = atoi(buf); 209 (void)fclose(fp); 210 } 211 212 needed = dumpsize / 1024 + 2; /* 2 for info file */ 213 if (((minfree > 0) ? spacefree : totfree) - needed < minfree) { 214 syslog(LOG_WARNING, 215 "no dump, not enough free space on device (%lld available, need %lld)", 216 (long long)(minfree > 0 ? spacefree : totfree), 217 (long long)needed); 218 return (0); 219 } 220 if (spacefree - needed < 0) 221 syslog(LOG_WARNING, 222 "dump performed, but free space threshold crossed"); 223 return (1); 224} 225 226#define BLOCKSIZE (1<<12) 227#define BLOCKMASK (~(BLOCKSIZE-1)) 228 229static void 230DoFile(const char *savedir, const char *device) 231{ 232 static char *buf = NULL; 233 struct kerneldumpheader kdhf, kdhl; 234 off_t mediasize, dumpsize, firsthd, lasthd, dmpcnt; 235 FILE *info, *fp; 236 mode_t oumask; 237 int fd, fdinfo, error, wl; 238 int nr, nw, hs, he = 0; 239 int bounds, status; 240 u_int sectorsize; 241 242 bounds = getbounds(); 243 dmpcnt = 0; 244 mediasize = 0; 245 status = STATUS_UNKNOWN; 246 247 if (buf == NULL) { 248 buf = malloc(BUFFERSIZE); 249 if (buf == NULL) { 250 syslog(LOG_ERR, "%m"); 251 return; 252 } 253 } 254 255 if (verbose) 256 printf("checking for kernel dump on device %s\n", device); 257 258 fd = open(device, O_RDWR); 259 if (fd < 0) { 260 syslog(LOG_ERR, "%s: %m", device); 261 return; 262 } 263 264 error = ioctl(fd, DIOCGMEDIASIZE, &mediasize); 265 if (!error) 266 error = ioctl(fd, DIOCGSECTORSIZE, §orsize); 267 if (error) { 268 syslog(LOG_ERR, 269 "couldn't find media and/or sector size of %s: %m", device); 270 goto closefd; 271 } 272 273 if (verbose) { 274 printf("mediasize = %lld\n", (long long)mediasize); 275 printf("sectorsize = %u\n", sectorsize); 276 } 277 278 lasthd = mediasize - sectorsize; 279 lseek(fd, lasthd, SEEK_SET); 280 error = read(fd, &kdhl, sizeof kdhl); 281 if (error != sizeof kdhl) { 282 syslog(LOG_ERR, 283 "error reading last dump header at offset %lld in %s: %m", 284 (long long)lasthd, device); 285 goto closefd; 286 } 287 if (memcmp(kdhl.magic, KERNELDUMPMAGIC, sizeof kdhl.magic)) { 288 if (verbose) 289 printf("magic mismatch on last dump header on %s\n", 290 device); 291 292 status = STATUS_BAD; 293 if (force == 0) 294 goto closefd; 295 296 if (memcmp(kdhl.magic, KERNELDUMPMAGIC_CLEARED, 297 sizeof kdhl.magic) == 0) { 298 if (verbose) 299 printf("forcing magic on %s\n", device); 300 memcpy(kdhl.magic, KERNELDUMPMAGIC, 301 sizeof kdhl.magic); 302 } else { 303 syslog(LOG_ERR, "unable to force dump - bad magic"); 304 goto closefd; 305 } 306 } 307 if (dtoh32(kdhl.version) != KERNELDUMPVERSION) { 308 syslog(LOG_ERR, 309 "unknown version (%d) in last dump header on %s", 310 dtoh32(kdhl.version), device); 311 312 status = STATUS_BAD; 313 if (force == 0) 314 goto closefd; 315 } 316 317 nfound++; 318 if (clear) 319 goto nuke; 320 321 if (kerneldump_parity(&kdhl)) { 322 syslog(LOG_ERR, 323 "parity error on last dump header on %s", device); 324 nerr++; 325 status = STATUS_BAD; 326 if (force == 0) 327 goto closefd; 328 } 329 dumpsize = dtoh64(kdhl.dumplength); 330 firsthd = lasthd - dumpsize - sizeof kdhf; 331 lseek(fd, firsthd, SEEK_SET); 332 error = read(fd, &kdhf, sizeof kdhf); 333 if (error != sizeof kdhf) { 334 syslog(LOG_ERR, 335 "error reading first dump header at offset %lld in %s: %m", 336 (long long)firsthd, device); 337 nerr++; 338 goto closefd; 339 } 340 341 if (verbose >= 2) { 342 printf("First dump headers:\n"); 343 printheader(stdout, &kdhf, device, bounds, -1); 344 345 printf("\nLast dump headers:\n"); 346 printheader(stdout, &kdhl, device, bounds, -1); 347 printf("\n"); 348 } 349 350 if (memcmp(&kdhl, &kdhf, sizeof kdhl)) { 351 syslog(LOG_ERR, 352 "first and last dump headers disagree on %s", device); 353 nerr++; 354 status = STATUS_BAD; 355 if (force == 0) 356 goto closefd; 357 } else { 358 status = STATUS_GOOD; 359 } 360 361 if (checkfor) { 362 printf("A dump exists on %s\n", device); 363 close(fd); 364 exit(0); 365 } 366 367 if (kdhl.panicstring[0]) 368 syslog(LOG_ALERT, "reboot after panic: %s", kdhl.panicstring); 369 else 370 syslog(LOG_ALERT, "reboot"); 371 372 if (verbose) 373 printf("Checking for available free space\n"); 374 if (!check_space(savedir, dumpsize)) { 375 nerr++; 376 goto closefd; 377 } 378 379 writebounds(bounds + 1); 380 381 sprintf(buf, "info.%d", bounds); 382 383 /* 384 * Create or overwrite any existing dump header files. 385 */ 386 fdinfo = open(buf, O_WRONLY | O_CREAT | O_TRUNC, 0600); 387 if (fdinfo < 0) { 388 syslog(LOG_ERR, "%s: %m", buf); 389 nerr++; 390 goto closefd; 391 } 392 oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/ 393 if (compress) { 394 sprintf(buf, "vmcore.%d.gz", bounds); 395 fp = zopen(buf, "w"); 396 } else { 397 sprintf(buf, "vmcore.%d", bounds); 398 fp = fopen(buf, "w"); 399 } 400 if (fp == NULL) { 401 syslog(LOG_ERR, "%s: %m", buf); 402 close(fdinfo); 403 nerr++; 404 goto closefd; 405 } 406 (void)umask(oumask); 407 408 info = fdopen(fdinfo, "w"); 409 410 if (verbose) 411 printheader(stdout, &kdhl, device, bounds, status); 412 413 printheader(info, &kdhl, device, bounds, status); 414 fclose(info); 415 416 syslog(LOG_NOTICE, "writing %score to %s", 417 compress ? "compressed " : "", buf); 418 419 while (dumpsize > 0) { 420 wl = BUFFERSIZE; 421 if (wl > dumpsize) 422 wl = dumpsize; 423 nr = read(fd, buf, wl); 424 if (nr != wl) { 425 if (nr == 0) 426 syslog(LOG_WARNING, 427 "WARNING: EOF on dump device"); 428 else 429 syslog(LOG_ERR, "read error on %s: %m", device); 430 nerr++; 431 goto closeall; 432 } 433 if (compress) { 434 nw = fwrite(buf, 1, wl, fp); 435 } else { 436 for (nw = 0; nw < nr; nw = he) { 437 /* find a contiguous block of zeroes */ 438 for (hs = nw; hs < nr; hs += BLOCKSIZE) { 439 for (he = hs; he < nr && buf[he] == 0; 440 ++he) 441 /* nothing */ ; 442 /* is the hole long enough to matter? */ 443 if (he >= hs + BLOCKSIZE) 444 break; 445 } 446 447 /* back down to a block boundary */ 448 he &= BLOCKMASK; 449 450 /* 451 * 1) Don't go beyond the end of the buffer. 452 * 2) If the end of the buffer is less than 453 * BLOCKSIZE bytes away, we're at the end 454 * of the file, so just grab what's left. 455 */ 456 if (hs + BLOCKSIZE > nr) 457 hs = he = nr; 458 459 /* 460 * At this point, we have a partial ordering: 461 * nw <= hs <= he <= nr 462 * If hs > nw, buf[nw..hs] contains non-zero data. 463 * If he > hs, buf[hs..he] is all zeroes. 464 */ 465 if (hs > nw) 466 if (fwrite(buf + nw, hs - nw, 1, fp) 467 != 1) 468 break; 469 if (he > hs) 470 if (fseeko(fp, he - hs, SEEK_CUR) == -1) 471 break; 472 } 473 } 474 if (nw != wl) { 475 syslog(LOG_ERR, 476 "write error on vmcore.%d file: %m", bounds); 477 syslog(LOG_WARNING, 478 "WARNING: vmcore may be incomplete"); 479 nerr++; 480 goto closeall; 481 } 482 if (verbose) { 483 dmpcnt += wl; 484 printf("%llu\r", (unsigned long long)dmpcnt); 485 fflush(stdout); 486 } 487 dumpsize -= wl; 488 } 489 if (verbose) 490 printf("\n"); 491 492 if (fclose(fp) < 0) { 493 syslog(LOG_ERR, "error on vmcore.%d: %m", bounds); 494 nerr++; 495 goto closeall; 496 } 497 nsaved++; 498 499 if (verbose) 500 printf("dump saved\n"); 501 502nuke: 503 if (clear || !keep) { 504 if (verbose) 505 printf("clearing dump header\n"); 506 memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof kdhl.magic); 507 lseek(fd, lasthd, SEEK_SET); 508 error = write(fd, &kdhl, sizeof kdhl); 509 if (error != sizeof kdhl) 510 syslog(LOG_ERR, 511 "error while clearing the dump header: %m"); 512 } 513 close(fd); 514 return; 515 516closeall: 517 fclose(fp); 518 519closefd: 520 close(fd); 521} 522 523static void 524usage(void) 525{ 526 fprintf(stderr, "%s\n%s\n%s\n", 527 "usage: savecore -c", 528 " savecore -C [-v] [directory device]", 529 " savecore [-fkvz] [directory [device ...]]"); 530 exit (1); 531} 532 533int 534main(int argc, char **argv) 535{ 536 const char *savedir = "."; 537 struct fstab *fsp; 538 int i, ch, error; 539 540 checkfor = compress = clear = force = keep = verbose = 0; 541 nfound = nsaved = nerr = 0; 542 543 openlog("savecore", LOG_PERROR, LOG_DAEMON); 544 545 while ((ch = getopt(argc, argv, "Ccfkvz")) != -1) 546 switch(ch) { 547 case 'C': 548 checkfor = 1; 549 break; 550 case 'c': 551 clear = 1; 552 break; 553 case 'k': 554 keep = 1; 555 break; 556 case 'v': 557 verbose++; 558 break; 559 case 'f': 560 force = 1; 561 break; 562 case 'z': 563 compress = 1; 564 break; 565 case '?': 566 default: 567 usage(); 568 } 569 if (checkfor && (clear || force || keep)) 570 usage(); 571 argc -= optind; 572 argv += optind; 573 if (argc >= 1) { 574 error = chdir(argv[0]); 575 if (error) { 576 syslog(LOG_ERR, "chdir(%s): %m", argv[0]); 577 exit(1); 578 } 579 savedir = argv[0]; 580 argc--; 581 argv++; 582 } 583 if (argc == 0) { 584 for (;;) { 585 fsp = getfsent(); 586 if (fsp == NULL) 587 break; 588 if (strcmp(fsp->fs_vfstype, "swap") && 589 strcmp(fsp->fs_vfstype, "dump")) 590 continue; 591 DoFile(savedir, fsp->fs_spec); 592 } 593 } else { 594 for (i = 0; i < argc; i++) 595 DoFile(savedir, argv[i]); 596 } 597 598 /* Emit minimal output. */ 599 if (nfound == 0) { 600 if (checkfor) { 601 printf("No dump exists\n"); 602 exit(1); 603 } 604 syslog(LOG_WARNING, "no dumps found"); 605 } 606 else if (nsaved == 0) { 607 if (nerr != 0) 608 syslog(LOG_WARNING, "unsaved dumps found but not saved"); 609 else 610 syslog(LOG_WARNING, "no unsaved dumps found"); 611 } 612 613 return (0); 614} 615