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 * @(#) Copyright (c) 1986, 1992, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)savecore.c 8.3 (Berkeley) 1/2/94 35 * $FreeBSD: src/sbin/savecore/savecore.c,v 1.28.2.13 2002/04/07 21:17:50 asmodai Exp $ 36 * $DragonFly: src/sbin/savecore/savecore.c,v 1.2 2003/06/17 04:27:34 dillon Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 #include <sys/mount.h> 42 #include <sys/syslog.h> 43 #include <sys/sysctl.h> 44 45 #include <vm/vm.h> 46 #include <vm/vm_param.h> 47 #include <vm/pmap.h> 48 49 #include <dirent.h> 50 #include <fcntl.h> 51 #include <nlist.h> 52 #include <paths.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 extern FILE *zopen(const char *fname, const char *mode); 59 60 #ifdef __alpha__ 61 #define ok(number) ALPHA_K0SEG_TO_PHYS(number) 62 #endif 63 64 #ifdef __i386__ 65 #define ok(number) ((number) - kernbase) 66 #endif 67 68 struct nlist current_nl[] = { /* Namelist for currently running system. */ 69 #define X_DUMPLO 0 70 { "_dumplo" }, 71 #define X_TIME 1 72 { "_time_second" }, 73 #define X_DUMPSIZE 2 74 { "_dumpsize" }, 75 #define X_VERSION 3 76 { "_version" }, 77 #define X_PANICSTR 4 78 { "_panicstr" }, 79 #define X_DUMPMAG 5 80 { "_dumpmag" }, 81 #define X_KERNBASE 6 82 { "_kernbase" }, 83 { "" }, 84 }; 85 int cursyms[] = { X_DUMPLO, X_VERSION, X_DUMPMAG, -1 }; 86 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 }; 87 88 struct nlist dump_nl[] = { /* Name list for dumped system. */ 89 { "_dumplo" }, /* Entries MUST be the same as */ 90 { "_time_second" }, /* those in current_nl[]. */ 91 { "_dumpsize" }, 92 { "_version" }, 93 { "_panicstr" }, 94 { "_dumpmag" }, 95 { "_kernbase" }, 96 { "" }, 97 }; 98 99 /* Types match kernel declarations. */ 100 u_long dumpmag; /* magic number in dump */ 101 102 /* Based on kernel variables, but with more convenient types. */ 103 off_t dumplo; /* where dump starts on dumpdev */ 104 off_t dumpsize; /* amount of memory dumped */ 105 106 char *kernel; /* user-specified kernel */ 107 char *savedir; /* directory to save dumps in */ 108 char ddname[MAXPATHLEN]; /* name of dump device */ 109 dev_t dumpdev; /* dump device */ 110 int dumpfd; /* read/write descriptor on char dev */ 111 time_t now; /* current date */ 112 char panic_mesg[1024]; /* panic message */ 113 int panicstr; /* flag: dump was caused by panic */ 114 char vers[1024]; /* version of kernel that crashed */ 115 116 #ifdef __i386__ 117 u_long kernbase; /* offset of kvm to core file */ 118 #endif 119 120 int clear, compress, force, verbose; /* flags */ 121 int keep; /* keep dump on device */ 122 123 void check_kmem __P((void)); 124 int check_space __P((void)); 125 void clear_dump __P((void)); 126 void DumpRead __P((int fd, void *bp, int size, off_t off, int flag)); 127 void DumpWrite __P((int fd, void *bp, int size, off_t off, int flag)); 128 int dump_exists __P((void)); 129 void find_dev __P((dev_t)); 130 int get_crashtime __P((void)); 131 void get_dumpsize __P((void)); 132 void kmem_setup __P((void)); 133 void log __P((int, char *, ...)) __printf0like(2, 3); 134 void Lseek __P((int, off_t, int)); 135 int Open __P((const char *, int rw)); 136 int Read __P((int, void *, int)); 137 void save_core __P((void)); 138 void usage __P((void)); 139 void Write __P((int, void *, int)); 140 141 int 142 main(argc, argv) 143 int argc; 144 char *argv[]; 145 { 146 int ch; 147 148 openlog("savecore", LOG_PERROR, LOG_DAEMON); 149 150 while ((ch = getopt(argc, argv, "cdfkN:vz")) != -1) 151 switch(ch) { 152 case 'c': 153 clear = 1; 154 break; 155 case 'd': /* Not documented. */ 156 case 'v': 157 verbose = 1; 158 break; 159 case 'f': 160 force = 1; 161 break; 162 case 'k': 163 keep = 1; 164 break; 165 case 'N': 166 kernel = optarg; 167 break; 168 case 'z': 169 compress = 1; 170 break; 171 case '?': 172 default: 173 usage(); 174 } 175 argc -= optind; 176 argv += optind; 177 178 if (!clear) { 179 if (argc != 1 && argc != 2) 180 usage(); 181 savedir = argv[0]; 182 } 183 if (argc == 2) 184 kernel = argv[1]; 185 186 (void)time(&now); 187 kmem_setup(); 188 189 if (clear) { 190 clear_dump(); 191 exit(0); 192 } 193 194 if (!dump_exists() && !force) 195 exit(1); 196 197 check_kmem(); 198 199 if (panicstr) 200 syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg); 201 else 202 syslog(LOG_ALERT, "reboot"); 203 204 get_dumpsize(); 205 206 if ((!get_crashtime() || !check_space()) && !force) 207 exit(1); 208 209 save_core(); 210 211 if (!keep) 212 clear_dump(); 213 214 exit(0); 215 } 216 217 void 218 kmem_setup() 219 { 220 int kmem, i; 221 const char *dump_sys; 222 size_t len; 223 long kdumplo; /* block number where dump starts on dumpdev */ 224 char *p; 225 226 /* 227 * Some names we need for the currently running system, others for 228 * the system that was running when the dump was made. The values 229 * obtained from the current system are used to look for things in 230 * /dev/kmem that cannot be found in the dump_sys namelist, but are 231 * presumed to be the same (since the disk partitions are probably 232 * the same!) 233 */ 234 if ((nlist(getbootfile(), current_nl)) == -1) 235 syslog(LOG_ERR, "%s: nlist: %m", getbootfile()); 236 for (i = 0; cursyms[i] != -1; i++) 237 if (current_nl[cursyms[i]].n_value == 0) { 238 syslog(LOG_ERR, "%s: %s not in namelist", 239 getbootfile(), current_nl[cursyms[i]].n_name); 240 exit(1); 241 } 242 243 dump_sys = kernel ? kernel : getbootfile(); 244 if ((nlist(dump_sys, dump_nl)) == -1) 245 syslog(LOG_ERR, "%s: nlist: %m", dump_sys); 246 for (i = 0; dumpsyms[i] != -1; i++) 247 if (dump_nl[dumpsyms[i]].n_value == 0) { 248 syslog(LOG_ERR, "%s: %s not in namelist", 249 dump_sys, dump_nl[dumpsyms[i]].n_name); 250 exit(1); 251 } 252 253 #ifdef __i386__ 254 if (dump_nl[X_KERNBASE].n_value != 0) 255 kernbase = dump_nl[X_KERNBASE].n_value; 256 else 257 kernbase = KERNBASE; 258 #endif 259 260 len = sizeof dumpdev; 261 if (sysctlbyname("kern.dumpdev", &dumpdev, &len, NULL, 0) == -1) { 262 syslog(LOG_ERR, "sysctl: kern.dumpdev: %m"); 263 exit(1); 264 } 265 if (dumpdev == NODEV) { 266 syslog(LOG_WARNING, "no core dump (no dumpdev)"); 267 exit(1); 268 } 269 270 kmem = Open(_PATH_KMEM, O_RDONLY); 271 Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET); 272 (void)Read(kmem, &kdumplo, sizeof(kdumplo)); 273 dumplo = (off_t)kdumplo * DEV_BSIZE; 274 if (verbose) 275 (void)printf("dumplo = %lld (%ld * %d)\n", 276 (long long)dumplo, kdumplo, DEV_BSIZE); 277 Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET); 278 (void)Read(kmem, &dumpmag, sizeof(dumpmag)); 279 find_dev(dumpdev); 280 dumpfd = Open(ddname, O_RDWR); 281 if (kernel) 282 return; 283 284 lseek(kmem, (off_t)current_nl[X_VERSION].n_value, SEEK_SET); 285 Read(kmem, vers, sizeof(vers)); 286 vers[sizeof(vers) - 1] = '\0'; 287 p = strchr(vers, '\n'); 288 if (p) 289 p[1] = '\0'; 290 291 /* Don't fclose(fp), we use kmem later. */ 292 } 293 294 void 295 check_kmem() 296 { 297 char core_vers[1024], *p; 298 299 DumpRead(dumpfd, core_vers, sizeof(core_vers), 300 (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET); 301 core_vers[sizeof(core_vers) - 1] = '\0'; 302 p = strchr(core_vers, '\n'); 303 if (p) 304 p[1] = '\0'; 305 if (strcmp(vers, core_vers) && kernel == 0) 306 syslog(LOG_WARNING, 307 "warning: %s version mismatch:\n\t\"%s\"\nand\t\"%s\"\n", 308 getbootfile(), vers, core_vers); 309 DumpRead(dumpfd, &panicstr, sizeof(panicstr), 310 (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET); 311 if (panicstr) { 312 DumpRead(dumpfd, panic_mesg, sizeof(panic_mesg), 313 (off_t)(dumplo + ok(panicstr)), L_SET); 314 } 315 } 316 317 /* 318 * Clear the magic number in the dump header. 319 */ 320 void 321 clear_dump() 322 { 323 u_long newdumpmag; 324 325 newdumpmag = 0; 326 DumpWrite(dumpfd, &newdumpmag, sizeof(newdumpmag), 327 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 328 close(dumpfd); 329 } 330 331 /* 332 * Check if a dump exists by looking for a magic number in the dump 333 * header. 334 */ 335 int 336 dump_exists() 337 { 338 u_long newdumpmag; 339 340 DumpRead(dumpfd, &newdumpmag, sizeof(newdumpmag), 341 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 342 if (newdumpmag != dumpmag) { 343 if (verbose) 344 syslog(LOG_WARNING, "magic number mismatch (%x != %x)", 345 newdumpmag, dumpmag); 346 syslog(LOG_WARNING, "no core dump"); 347 return (0); 348 } 349 return (1); 350 } 351 352 char buf[1024 * 1024]; 353 #define BLOCKSIZE (1<<12) 354 #define BLOCKMASK (~(BLOCKSIZE-1)) 355 356 /* 357 * Save the core dump. 358 */ 359 void 360 save_core() 361 { 362 register FILE *fp; 363 register int bounds, ifd, nr, nw; 364 int hs, he; /* start and end of hole */ 365 char path[MAXPATHLEN]; 366 mode_t oumask; 367 368 /* 369 * Get the current number and update the bounds file. Do the update 370 * now, because may fail later and don't want to overwrite anything. 371 */ 372 (void)snprintf(path, sizeof(path), "%s/bounds", savedir); 373 if ((fp = fopen(path, "r")) == NULL) 374 goto err1; 375 if (fgets(buf, sizeof(buf), fp) == NULL) { 376 if (ferror(fp)) 377 err1: syslog(LOG_WARNING, "%s: %m", path); 378 bounds = 0; 379 } else 380 bounds = atoi(buf); 381 if (fp != NULL) 382 (void)fclose(fp); 383 if ((fp = fopen(path, "w")) == NULL) 384 syslog(LOG_ERR, "%s: %m", path); 385 else { 386 (void)fprintf(fp, "%d\n", bounds + 1); 387 (void)fclose(fp); 388 } 389 390 /* Create the core file. */ 391 oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/ 392 (void)snprintf(path, sizeof(path), "%s/vmcore.%d%s", 393 savedir, bounds, compress ? ".gz" : ""); 394 if (compress) 395 fp = zopen(path, "w"); 396 else 397 fp = fopen(path, "w"); 398 if (fp == NULL) { 399 syslog(LOG_ERR, "%s: %m", path); 400 exit(1); 401 } 402 (void)umask(oumask); 403 404 /* Seek to the start of the core. */ 405 Lseek(dumpfd, (off_t)dumplo, L_SET); 406 407 /* Copy the core file. */ 408 syslog(LOG_NOTICE, "writing %score to %s", 409 compress ? "compressed " : "", path); 410 for (; dumpsize > 0; dumpsize -= nr) { 411 (void)printf("%6dK\r", dumpsize / 1024); 412 (void)fflush(stdout); 413 nr = read(dumpfd, buf, MIN(dumpsize, sizeof(buf))); 414 if (nr <= 0) { 415 if (nr == 0) 416 syslog(LOG_WARNING, 417 "WARNING: EOF on dump device"); 418 else 419 syslog(LOG_ERR, "%s: %m", ddname); 420 goto err2; 421 } 422 for (nw = 0; nw < nr; nw = he) { 423 /* find a contiguous block of zeroes */ 424 for (hs = nw; hs < nr; hs += BLOCKSIZE) { 425 for (he = hs; he < nr && buf[he] == 0; ++he) 426 /* nothing */ ; 427 428 /* is the hole long enough to matter? */ 429 if (he >= hs + BLOCKSIZE) 430 break; 431 } 432 433 /* back down to a block boundary */ 434 he &= BLOCKMASK; 435 436 /* 437 * 1) Don't go beyond the end of the buffer. 438 * 2) If the end of the buffer is less than 439 * BLOCKSIZE bytes away, we're at the end 440 * of the file, so just grab what's left. 441 */ 442 if (hs + BLOCKSIZE > nr) 443 hs = he = nr; 444 445 /* 446 * At this point, we have a partial ordering: 447 * nw <= hs <= he <= nr 448 * If hs > nw, buf[nw..hs] contains non-zero data. 449 * If he > hs, buf[hs..he] is all zeroes. 450 */ 451 if (hs > nw) 452 if (fwrite(buf + nw, hs - nw, 1, fp) != 1) 453 break; 454 if (he > hs) 455 if (fseeko(fp, he - hs, SEEK_CUR) == -1) 456 break; 457 } 458 if (nw != nr) { 459 syslog(LOG_ERR, "%s: %m", path); 460 err2: syslog(LOG_WARNING, 461 "WARNING: vmcore may be incomplete"); 462 (void)printf("\n"); 463 exit(1); 464 } 465 } 466 467 (void)fclose(fp); 468 469 /* Copy the kernel. */ 470 ifd = Open(kernel ? kernel : getbootfile(), O_RDONLY); 471 (void)snprintf(path, sizeof(path), "%s/kernel.%d%s", 472 savedir, bounds, compress ? ".gz" : ""); 473 if (compress) 474 fp = zopen(path, "w"); 475 else 476 fp = fopen(path, "w"); 477 if (fp == NULL) { 478 syslog(LOG_ERR, "%s: %m", path); 479 exit(1); 480 } 481 syslog(LOG_NOTICE, "writing %skernel to %s", 482 compress ? "compressed " : "", path); 483 while ((nr = read(ifd, buf, sizeof(buf))) > 0) { 484 nw = fwrite(buf, 1, nr, fp); 485 if (nw != nr) { 486 syslog(LOG_ERR, "%s: %m", path); 487 syslog(LOG_WARNING, 488 "WARNING: kernel may be incomplete"); 489 exit(1); 490 } 491 } 492 if (nr < 0) { 493 syslog(LOG_ERR, "%s: %m", kernel ? kernel : getbootfile()); 494 syslog(LOG_WARNING, 495 "WARNING: kernel may be incomplete"); 496 exit(1); 497 } 498 (void)fclose(fp); 499 close(ifd); 500 } 501 502 /* 503 * Verify that the specified device node exists and matches the 504 * specified device. 505 */ 506 int 507 verify_dev(name, dev) 508 char *name; 509 register dev_t dev; 510 { 511 struct stat sb; 512 513 if (lstat(name, &sb) == -1) 514 return (-1); 515 if (!S_ISCHR(sb.st_mode) || sb.st_rdev != dev) 516 return (-1); 517 return (0); 518 } 519 520 /* 521 * Find the dump device. 522 * 523 * 1) try devname(3); see if it returns something sensible 524 * 2) scan /dev for the desired node 525 * 3) as a last resort, try to create the node we need 526 */ 527 void 528 find_dev(dev) 529 register dev_t dev; 530 { 531 struct dirent *ent; 532 char *dn, *dnp; 533 DIR *d; 534 535 strcpy(ddname, _PATH_DEV); 536 dnp = ddname + sizeof _PATH_DEV - 1; 537 if ((dn = devname(dev, S_IFCHR)) != NULL) { 538 strcpy(dnp, dn); 539 if (verify_dev(ddname, dev) == 0) 540 return; 541 } 542 if ((d = opendir(_PATH_DEV)) != NULL) { 543 while ((ent = readdir(d))) { 544 strcpy(dnp, ent->d_name); 545 if (verify_dev(ddname, dev) == 0) { 546 closedir(d); 547 return; 548 } 549 } 550 closedir(d); 551 } 552 strcpy(dnp, "dump"); 553 if (mknod(ddname, S_IFCHR|S_IRUSR|S_IWUSR, dev) == 0) 554 return; 555 syslog(LOG_ERR, "can't find device %d/%#x", major(dev), minor(dev)); 556 exit(1); 557 } 558 559 /* 560 * Extract the date and time of the crash from the dump header, and 561 * make sure it looks sane (within one week of current date and time). 562 */ 563 int 564 get_crashtime() 565 { 566 time_t dumptime; /* Time the dump was taken. */ 567 568 DumpRead(dumpfd, &dumptime, sizeof(dumptime), 569 (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET); 570 if (dumptime == 0) { 571 if (verbose) 572 syslog(LOG_ERR, "dump time is zero"); 573 return (0); 574 } 575 (void)printf("savecore: system went down at %s", ctime(&dumptime)); 576 #define LEEWAY (7 * 86400) 577 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) { 578 (void)printf("dump time is unreasonable\n"); 579 return (0); 580 } 581 return (1); 582 } 583 584 /* 585 * Extract the size of the dump from the dump header. 586 */ 587 void 588 get_dumpsize() 589 { 590 int kdumpsize; /* Number of pages in dump. */ 591 592 /* Read the dump size. */ 593 DumpRead(dumpfd, &kdumpsize, sizeof(kdumpsize), 594 (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET); 595 dumpsize = (off_t)kdumpsize * getpagesize(); 596 } 597 598 /* 599 * Check that sufficient space is available on the disk that holds the 600 * save directory. 601 */ 602 int 603 check_space() 604 { 605 register FILE *fp; 606 const char *tkernel; 607 off_t minfree, spacefree, totfree, kernelsize, needed; 608 struct stat st; 609 struct statfs fsbuf; 610 char buf[100], path[MAXPATHLEN]; 611 612 tkernel = kernel ? kernel : getbootfile(); 613 if (stat(tkernel, &st) < 0) { 614 syslog(LOG_ERR, "%s: %m", tkernel); 615 exit(1); 616 } 617 kernelsize = st.st_blocks * S_BLKSIZE; 618 619 if (statfs(savedir, &fsbuf) < 0) { 620 syslog(LOG_ERR, "%s: %m", savedir); 621 exit(1); 622 } 623 spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024; 624 totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024; 625 626 (void)snprintf(path, sizeof(path), "%s/minfree", savedir); 627 if ((fp = fopen(path, "r")) == NULL) 628 minfree = 0; 629 else { 630 if (fgets(buf, sizeof(buf), fp) == NULL) 631 minfree = 0; 632 else 633 minfree = atoi(buf); 634 (void)fclose(fp); 635 } 636 637 needed = (dumpsize + kernelsize) / 1024; 638 if (((minfree > 0) ? spacefree : totfree) - needed < minfree) { 639 syslog(LOG_WARNING, 640 "no dump, not enough free space on device (%lld available, need %lld)", 641 (long long)(minfree > 0 ? spacefree : totfree), 642 (long long)needed); 643 return (0); 644 } 645 if (spacefree - needed < 0) 646 syslog(LOG_WARNING, 647 "dump performed, but free space threshold crossed"); 648 return (1); 649 } 650 651 int 652 Open(name, rw) 653 const char *name; 654 int rw; 655 { 656 int fd; 657 658 if ((fd = open(name, rw, 0)) < 0) { 659 syslog(LOG_ERR, "%s: %m", name); 660 exit(1); 661 } 662 return (fd); 663 } 664 665 int 666 Read(fd, bp, size) 667 int fd, size; 668 void *bp; 669 { 670 int nr; 671 672 nr = read(fd, bp, size); 673 if (nr != size) { 674 syslog(LOG_ERR, "read: %m"); 675 exit(1); 676 } 677 return (nr); 678 } 679 680 void 681 Lseek(fd, off, flag) 682 int fd, flag; 683 off_t off; 684 { 685 off_t ret; 686 687 ret = lseek(fd, off, flag); 688 if (ret == -1) { 689 syslog(LOG_ERR, "lseek: %m"); 690 exit(1); 691 } 692 } 693 694 /* 695 * DumpWrite and DumpRead block io requests to the * dump device. 696 */ 697 #define DUMPBUFSIZE 8192 698 void 699 DumpWrite(fd, bp, size, off, flag) 700 int fd, size, flag; 701 void *bp; 702 off_t off; 703 { 704 unsigned char buf[DUMPBUFSIZE], *p, *q; 705 off_t pos; 706 int i, j; 707 708 if (flag != L_SET) { 709 syslog(LOG_ERR, "lseek: not LSET"); 710 exit(2); 711 } 712 q = bp; 713 while (size) { 714 pos = off & ~(DUMPBUFSIZE - 1); 715 Lseek(fd, pos, flag); 716 (void)Read(fd, buf, sizeof(buf)); 717 j = off & (DUMPBUFSIZE - 1); 718 p = buf + j; 719 i = size; 720 if (i > DUMPBUFSIZE - j) 721 i = DUMPBUFSIZE - j; 722 memcpy(p, q, i); 723 Lseek(fd, pos, flag); 724 (void)Write(fd, buf, sizeof(buf)); 725 size -= i; 726 q += i; 727 off += i; 728 } 729 } 730 731 void 732 DumpRead(fd, bp, size, off, flag) 733 int fd, size, flag; 734 void *bp; 735 off_t off; 736 { 737 unsigned char buf[DUMPBUFSIZE], *p, *q; 738 off_t pos; 739 int i, j; 740 741 if (flag != L_SET) { 742 syslog(LOG_ERR, "lseek: not LSET"); 743 exit(2); 744 } 745 q = bp; 746 while (size) { 747 pos = off & ~(DUMPBUFSIZE - 1); 748 Lseek(fd, pos, flag); 749 (void)Read(fd, buf, sizeof(buf)); 750 j = off & (DUMPBUFSIZE - 1); 751 p = buf + j; 752 i = size; 753 if (i > DUMPBUFSIZE - j) 754 i = DUMPBUFSIZE - j; 755 memcpy(q, p, i); 756 size -= i; 757 q += i; 758 off += i; 759 } 760 } 761 762 void 763 Write(fd, bp, size) 764 int fd, size; 765 void *bp; 766 { 767 int n; 768 769 if ((n = write(fd, bp, size)) < size) { 770 syslog(LOG_ERR, "write: %m"); 771 exit(1); 772 } 773 } 774 775 void 776 usage() 777 { 778 (void)syslog(LOG_ERR, "usage: savecore [-cfkvz] [-N system] directory"); 779 exit(1); 780 } 781