savecore.c revision 1.22
1/* $NetBSD: savecore.c,v 1.22 1995/06/25 06:28:13 cgd 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 36#ifndef lint 37static char copyright[] = 38"@(#) Copyright (c) 1986, 1992, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"; 40#endif /* not lint */ 41 42#ifndef lint 43#if 0 44static char sccsid[] = "@(#)savecore.c 8.3 (Berkeley) 1/2/94"; 45#else 46static char rcsid[] = "$NetBSD: savecore.c,v 1.22 1995/06/25 06:28:13 cgd Exp $"; 47#endif 48#endif /* not lint */ 49 50#include <sys/param.h> 51#include <sys/stat.h> 52#include <sys/mount.h> 53#include <sys/syslog.h> 54#include <sys/time.h> 55 56#include <dirent.h> 57#include <errno.h> 58#include <fcntl.h> 59#include <nlist.h> 60#include <paths.h> 61#include <stdio.h> 62#include <stdlib.h> 63#include <string.h> 64#include <tzfile.h> 65#include <unistd.h> 66 67extern FILE *zopen __P((const char *fname, const char *mode, int bits)); 68 69#define ok(number) ((number) - KERNBASE) 70 71struct nlist current_nl[] = { /* Namelist for currently running system. */ 72#define X_DUMPDEV 0 73 { "_dumpdev" }, 74#define X_DUMPLO 1 75 { "_dumplo" }, 76#define X_TIME 2 77 { "_time" }, 78#define X_DUMPSIZE 3 79 { "_dumpsize" }, 80#define X_VERSION 4 81 { "_version" }, 82#define X_PANICSTR 5 83 { "_panicstr" }, 84#define X_DUMPMAG 6 85 { "_dumpmag" }, 86 { "" }, 87}; 88int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 }; 89int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 }; 90 91struct nlist dump_nl[] = { /* Name list for dumped system. */ 92 { "_dumpdev" }, /* Entries MUST be the same as */ 93 { "_dumplo" }, /* those in current_nl[]. */ 94 { "_time" }, 95 { "_dumpsize" }, 96 { "_version" }, 97 { "_panicstr" }, 98 { "_dumpmag" }, 99 { "" }, 100}; 101 102/* Types match kernel declarations. */ 103long dumplo; /* where dump starts on dumpdev */ 104int dumpmag; /* magic number in dump */ 105int dumpsize; /* amount of memory dumped */ 106 107char *kernel; 108char *dirname; /* directory to save dumps in */ 109char *ddname; /* name of dump device */ 110dev_t dumpdev; /* dump device */ 111int dumpfd; /* read/write descriptor on block dev */ 112time_t now; /* current date */ 113char panic_mesg[1024]; 114int panicstr; 115char vers[1024]; 116 117int clear, compress, force, verbose; /* flags */ 118 119void check_kmem __P((void)); 120int check_space __P((void)); 121void clear_dump __P((void)); 122int Create __P((char *, int)); 123int dump_exists __P((void)); 124char *find_dev __P((dev_t, int)); 125int get_crashtime __P((void)); 126void kmem_setup __P((void)); 127void log __P((int, char *, ...)); 128void Lseek __P((int, off_t, int)); 129int Open __P((char *, int rw)); 130int Read __P((int, void *, int)); 131char *rawname __P((char *s)); 132void save_core __P((void)); 133void usage __P((void)); 134void Write __P((int, void *, int)); 135 136int 137main(argc, argv) 138 int argc; 139 char *argv[]; 140{ 141 int ch; 142 143 openlog("savecore", LOG_PERROR, LOG_DAEMON); 144 145 while ((ch = getopt(argc, argv, "cdfN:vz")) != -1) 146 switch(ch) { 147 case 'c': 148 clear = 1; 149 break; 150 case 'd': /* Not documented. */ 151 case 'v': 152 verbose = 1; 153 break; 154 case 'f': 155 force = 1; 156 break; 157 case 'N': 158 kernel = optarg; 159 break; 160 case 'z': 161 compress = 1; 162 break; 163 case '?': 164 default: 165 usage(); 166 } 167 argc -= optind; 168 argv += optind; 169 170 if (!clear) { 171 if (argc != 1 && argc != 2) 172 usage(); 173 dirname = argv[0]; 174 } 175 if (argc == 2) 176 kernel = argv[1]; 177 178 (void)time(&now); 179 kmem_setup(); 180 181 if (clear) { 182 clear_dump(); 183 exit(0); 184 } 185 186 if (!dump_exists() && !force) 187 exit(1); 188 189 check_kmem(); 190 191 if (panicstr) 192 syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg); 193 else 194 syslog(LOG_ALERT, "reboot"); 195 196 if ((!get_crashtime() || !check_space()) && !force) 197 exit(1); 198 199 save_core(); 200 201 clear_dump(); 202 exit(0); 203} 204 205void 206kmem_setup() 207{ 208 FILE *fp; 209 int kmem, i; 210 char *dump_sys; 211 212 /* 213 * Some names we need for the currently running system, others for 214 * the system that was running when the dump was made. The values 215 * obtained from the current system are used to look for things in 216 * /dev/kmem that cannot be found in the dump_sys namelist, but are 217 * presumed to be the same (since the disk partitions are probably 218 * the same!) 219 */ 220 if ((nlist(_PATH_UNIX, current_nl)) == -1) 221 syslog(LOG_ERR, "%s: nlist: %s", _PATH_UNIX, strerror(errno)); 222 for (i = 0; cursyms[i] != -1; i++) 223 if (current_nl[cursyms[i]].n_value == 0) { 224 syslog(LOG_ERR, "%s: %s not in namelist", 225 _PATH_UNIX, current_nl[cursyms[i]].n_name); 226 exit(1); 227 } 228 229 dump_sys = kernel ? kernel : _PATH_UNIX; 230 if ((nlist(dump_sys, dump_nl)) == -1) 231 syslog(LOG_ERR, "%s: nlist: %s", dump_sys, strerror(errno)); 232 for (i = 0; dumpsyms[i] != -1; i++) 233 if (dump_nl[dumpsyms[i]].n_value == 0) { 234 syslog(LOG_ERR, "%s: %s not in namelist", 235 dump_sys, dump_nl[dumpsyms[i]].n_name); 236 exit(1); 237 } 238 239 kmem = Open(_PATH_KMEM, O_RDONLY); 240 Lseek(kmem, (off_t)current_nl[X_DUMPDEV].n_value, L_SET); 241 (void)Read(kmem, &dumpdev, sizeof(dumpdev)); 242 if (dumpdev == NODEV) { 243 syslog(LOG_WARNING, "no core dump (no dumpdev)"); 244 exit(1); 245 } 246 Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET); 247 (void)Read(kmem, &dumplo, sizeof(dumplo)); 248 dumplo *= DEV_BSIZE; 249 if (verbose) 250 (void)printf("dumplo = %d (%d * %d)\n", 251 dumplo, dumplo / DEV_BSIZE, DEV_BSIZE); 252 Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET); 253 (void)Read(kmem, &dumpmag, sizeof(dumpmag)); 254 ddname = find_dev(dumpdev, S_IFBLK); 255 dumpfd = Open(ddname, O_RDWR); 256 fp = fdopen(kmem, "r"); 257 if (fp == NULL) { 258 syslog(LOG_ERR, "%s: fdopen: %m", _PATH_KMEM); 259 exit(1); 260 } 261 if (kernel) 262 return; 263 (void)fseek(fp, (off_t)current_nl[X_VERSION].n_value, L_SET); 264 (void)fgets(vers, sizeof(vers), fp); 265 266 /* Don't fclose(fp), we use dumpfd later. */ 267} 268 269void 270check_kmem() 271{ 272 register char *cp; 273 FILE *fp; 274 char core_vers[1024]; 275 276 fp = fdopen(dumpfd, "r"); 277 if (fp == NULL) { 278 syslog(LOG_ERR, "%s: fdopen: %m", ddname); 279 exit(1); 280 } 281 fseek(fp, (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET); 282 fgets(core_vers, sizeof(core_vers), fp); 283 if (strcmp(vers, core_vers) && kernel == 0) 284 syslog(LOG_WARNING, 285 "warning: %s version mismatch:\n\t%s\nand\t%s\n", 286 _PATH_UNIX, vers, core_vers); 287 (void)fseek(fp, 288 (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET); 289 (void)fread(&panicstr, sizeof(panicstr), 1, fp); 290 if (panicstr) { 291 (void)fseek(fp, dumplo + ok(panicstr), L_SET); 292 cp = panic_mesg; 293 do 294 *cp = getc(fp); 295 while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)]); 296 } 297 /* Don't fclose(fp), we use dumpfd later. */ 298} 299 300void 301clear_dump() 302{ 303 long newdumplo; 304 305 newdumplo = 0; 306 Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 307 Write(dumpfd, &newdumplo, sizeof(newdumplo)); 308} 309 310int 311dump_exists() 312{ 313 int newdumpmag; 314 315 Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 316 (void)Read(dumpfd, &newdumpmag, sizeof(newdumpmag)); 317 if (newdumpmag != dumpmag) { 318 if (verbose) 319 syslog(LOG_WARNING, "magic number mismatch (%x != %x)", 320 newdumpmag, dumpmag); 321 syslog(LOG_WARNING, "no core dump"); 322 return (0); 323 } 324 return (1); 325} 326 327char buf[1024 * 1024]; 328 329void 330save_core() 331{ 332 register FILE *fp; 333 register int bounds, ifd, nr, nw, ofd; 334 char *rawp, path[MAXPATHLEN]; 335 336 /* 337 * Get the current number and update the bounds file. Do the update 338 * now, because may fail later and don't want to overwrite anything. 339 */ 340 (void)snprintf(path, sizeof(path), "%s/bounds", dirname); 341 if ((fp = fopen(path, "r")) == NULL) 342 goto err1; 343 if (fgets(buf, sizeof(buf), fp) == NULL) { 344 if (ferror(fp)) 345err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno)); 346 bounds = 0; 347 } else 348 bounds = atoi(buf); 349 if (fp != NULL) 350 (void)fclose(fp); 351 if ((fp = fopen(path, "w")) == NULL) 352 syslog(LOG_ERR, "%s: %m", path); 353 else { 354 (void)fprintf(fp, "%d\n", bounds + 1); 355 (void)fclose(fp); 356 } 357 (void)fclose(fp); 358 359 /* Create the core file. */ 360 (void)snprintf(path, sizeof(path), "%s/netbsd.%d%s.core", 361 dirname, bounds, compress ? ".Z" : ""); 362 if (compress) { 363 if ((fp = zopen(path, "w", 0)) == NULL) { 364 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 365 exit(1); 366 } 367 } else 368 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 369 370 /* Open the raw device. */ 371 rawp = rawname(ddname); 372 if ((ifd = open(rawp, O_RDONLY)) == -1) { 373 syslog(LOG_WARNING, "%s: %m; using block device", rawp); 374 ifd = dumpfd; 375 } 376 377 /* Read the dump size. */ 378 Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET); 379 (void)Read(dumpfd, &dumpsize, sizeof(dumpsize)); 380 381 /* Seek to the start of the core. */ 382 Lseek(ifd, (off_t)dumplo, L_SET); 383 384 /* Copy the core file. */ 385 dumpsize *= getpagesize(); 386 syslog(LOG_NOTICE, "writing %score to %s", 387 compress ? "compressed " : "", path); 388 for (; dumpsize > 0; dumpsize -= nr) { 389 (void)printf("%6dK\r", dumpsize / 1024); 390 (void)fflush(stdout); 391 nr = read(ifd, buf, MIN(dumpsize, sizeof(buf))); 392 if (nr <= 0) { 393 if (nr == 0) 394 syslog(LOG_WARNING, 395 "WARNING: EOF on dump device"); 396 else 397 syslog(LOG_ERR, "%s: %m", rawp); 398 goto err2; 399 } 400 if (compress) 401 nw = fwrite(buf, 1, nr, fp); 402 else 403 nw = write(ofd, buf, nr); 404 if (nw != nr) { 405 syslog(LOG_ERR, "%s: %s", 406 path, strerror(nw == 0 ? EIO : errno)); 407err2: syslog(LOG_WARNING, 408 "WARNING: core may be incomplete"); 409 (void)printf("\n"); 410 exit(1); 411 } 412 } 413 (void)close(ifd); 414 if (compress) 415 (void)fclose(fp); 416 else 417 (void)close(ofd); 418 419 /* Copy the kernel. */ 420 ifd = Open(kernel ? kernel : _PATH_UNIX, O_RDONLY); 421 (void)snprintf(path, sizeof(path), "%s/netbsd.%d%s", 422 dirname, bounds, compress ? ".Z" : ""); 423 if (compress) { 424 if ((fp = zopen(path, "w", 0)) == NULL) { 425 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 426 exit(1); 427 } 428 } else 429 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 430 syslog(LOG_NOTICE, "writing %skernel to %s", 431 compress ? "compressed " : "", path); 432 while ((nr = read(ifd, buf, sizeof(buf))) > 0) { 433 if (compress) 434 nw = fwrite(buf, 1, nr, fp); 435 else 436 nw = write(ofd, buf, nr); 437 if (nw != nr) { 438 syslog(LOG_ERR, "%s: %s", 439 path, strerror(nw == 0 ? EIO : errno)); 440 syslog(LOG_WARNING, 441 "WARNING: kernel may be incomplete"); 442 exit(1); 443 } 444 } 445 if (nr < 0) { 446 syslog(LOG_ERR, "%s: %s", 447 kernel ? kernel : _PATH_UNIX, strerror(errno)); 448 syslog(LOG_WARNING, 449 "WARNING: kernel may be incomplete"); 450 exit(1); 451 } 452 if (compress) 453 (void)fclose(fp); 454 else 455 (void)close(ofd); 456} 457 458char * 459find_dev(dev, type) 460 register dev_t dev; 461 register int type; 462{ 463 register DIR *dfd; 464 struct dirent *dir; 465 struct stat sb; 466 char *dp, devname[MAXPATHLEN + 1]; 467 468 if ((dfd = opendir(_PATH_DEV)) == NULL) { 469 syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno)); 470 exit(1); 471 } 472 (void)strcpy(devname, _PATH_DEV); 473 while ((dir = readdir(dfd))) { 474 (void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name); 475 if (lstat(devname, &sb)) { 476 syslog(LOG_ERR, "%s: %s", devname, strerror(errno)); 477 continue; 478 } 479 if ((sb.st_mode & S_IFMT) != type) 480 continue; 481 if (dev == sb.st_rdev) { 482 closedir(dfd); 483 if ((dp = strdup(devname)) == NULL) { 484 syslog(LOG_ERR, "%s", strerror(errno)); 485 exit(1); 486 } 487 return (dp); 488 } 489 } 490 closedir(dfd); 491 syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev)); 492 exit(1); 493} 494 495char * 496rawname(s) 497 char *s; 498{ 499 char *sl, name[MAXPATHLEN]; 500 501 if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') { 502 syslog(LOG_ERR, 503 "can't make raw dump device name from %s", s); 504 return (s); 505 } 506 (void)snprintf(name, sizeof(name), "%.*s/r%s", sl - s, s, sl + 1); 507 if ((sl = strdup(name)) == NULL) { 508 syslog(LOG_ERR, "%s", strerror(errno)); 509 exit(1); 510 } 511 return (sl); 512} 513 514int 515get_crashtime() 516{ 517 time_t dumptime; /* Time the dump was taken. */ 518 519 Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET); 520 (void)Read(dumpfd, &dumptime, sizeof(dumptime)); 521 if (dumptime == 0) { 522 if (verbose) 523 syslog(LOG_ERR, "dump time is zero"); 524 return (0); 525 } 526 (void)printf("savecore: system went down at %s", ctime(&dumptime)); 527#define LEEWAY (7 * SECSPERDAY) 528 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) { 529 (void)printf("dump time is unreasonable\n"); 530 return (0); 531 } 532 return (1); 533} 534 535int 536check_space() 537{ 538 register FILE *fp; 539 char *tkernel; 540 off_t minfree, spacefree, kernelsize, needed; 541 struct stat st; 542 struct statfs fsbuf; 543 char buf[100], path[MAXPATHLEN]; 544 545 tkernel = kernel ? kernel : _PATH_UNIX; 546 if (stat(tkernel, &st) < 0) { 547 syslog(LOG_ERR, "%s: %m", tkernel); 548 exit(1); 549 } 550 kernelsize = st.st_blocks * S_BLKSIZE; 551 if (statfs(dirname, &fsbuf) < 0) { 552 syslog(LOG_ERR, "%s: %m", dirname); 553 exit(1); 554 } 555 spacefree = (fsbuf.f_bavail * fsbuf.f_bsize) / 1024; 556 557 (void)snprintf(path, sizeof(path), "%s/minfree", dirname); 558 if ((fp = fopen(path, "r")) == NULL) 559 minfree = 0; 560 else { 561 if (fgets(buf, sizeof(buf), fp) == NULL) 562 minfree = 0; 563 else 564 minfree = atoi(buf); 565 (void)fclose(fp); 566 } 567 568 needed = (dumpsize + kernelsize) / 1024; 569 if (minfree > 0 && spacefree - needed < minfree) { 570 syslog(LOG_WARNING, 571 "no dump, not enough free space on device"); 572 return (0); 573 } 574 if (spacefree - needed < minfree) 575 syslog(LOG_WARNING, 576 "dump performed, but free space threshold crossed"); 577 return (1); 578} 579 580int 581Open(name, rw) 582 char *name; 583 int rw; 584{ 585 int fd; 586 587 if ((fd = open(name, rw, 0)) < 0) { 588 syslog(LOG_ERR, "%s: %m", name); 589 exit(1); 590 } 591 return (fd); 592} 593 594int 595Read(fd, bp, size) 596 int fd, size; 597 void *bp; 598{ 599 int nr; 600 601 nr = read(fd, bp, size); 602 if (nr != size) { 603 syslog(LOG_ERR, "read: %m"); 604 exit(1); 605 } 606 return (nr); 607} 608 609void 610Lseek(fd, off, flag) 611 int fd, flag; 612 off_t off; 613{ 614 off_t ret; 615 616 ret = lseek(fd, off, flag); 617 if (ret == -1) { 618 syslog(LOG_ERR, "lseek: %m"); 619 exit(1); 620 } 621} 622 623int 624Create(file, mode) 625 char *file; 626 int mode; 627{ 628 register int fd; 629 630 fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode); 631 if (fd < 0) { 632 syslog(LOG_ERR, "%s: %m", file); 633 exit(1); 634 } 635 return (fd); 636} 637 638void 639Write(fd, bp, size) 640 int fd, size; 641 void *bp; 642{ 643 int n; 644 645 if ((n = write(fd, bp, size)) < size) { 646 syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO)); 647 exit(1); 648 } 649} 650 651void 652usage() 653{ 654 (void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory"); 655 exit(1); 656} 657