sbin/savecore/savecore.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 2002 Poul-Henning Kamp
   5  * Copyright (c) 2002 Networks Associates Technology, Inc.
   6  * All rights reserved.
   7  *
   8  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
   9  * and NAI Labs, the Security Research Division of Network Associates, Inc.
  10  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
  11  * DARPA CHATS research program.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. The names of the authors may not be used to endorse or promote
  22  *    products derived from this software without specific prior written
  23  *    permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  * Copyright (c) 1986, 1992, 1993
  38  *      The Regents of the University of California.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #include <sys/param.h>
  69 #include <sys/disk.h>
  70 #include <sys/kerneldump.h>
  71 #include <sys/mount.h>
  72 #include <sys/stat.h>
  73 #include <ctype.h>
  74 #include <errno.h>
  75 #include <fcntl.h>
  76 #include <fstab.h>
  77 #include <paths.h>
  78 #include <signal.h>
  79 #include <stdarg.h>
  80 #include <stdbool.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 #include <libxo/xo.h>
  88
  89 /* The size of the buffer used for I/O. */
  90 #define BUFFERSIZE      (1024*1024)
  91
  92 #define STATUS_BAD      0
  93 #define STATUS_GOOD     1
  94 #define STATUS_UNKNOWN  2
  95
  96 static int checkfor, compress, clear, force, keep, verbose;     /* flags */
  97 static int nfound, nsaved, nerr;                        /* statistics */
  98 static int maxdumps;
  99
 100 extern FILE *zopen(const char *, const char *);
 101
 102 static sig_atomic_t got_siginfo;
 103 static void infohandler(int);
 104
 105 static void
 106 printheader(xo_handle_t *xo, const struct kerneldumpheader *h,
 107     const char *device, int bounds, const int status)
 108 {
 109         uint64_t dumplen;
 110         time_t t;
 111         const char *stat_str;
 112         const char *comp_str;
 113
 114         xo_flush_h(xo);
 115         xo_emit_h(xo, "{Lwc:Dump header from device}{:dump_device/%s}\n",
 116             device);
 117         xo_emit_h(xo, "{P:  }{Lwc:Architecture}{:architecture/%s}\n",
 118             h->architecture);
 119         xo_emit_h(xo,
 120             "{P:  }{Lwc:Architecture Version}{:architecture_version/%u}\n",
 121             dtoh32(h->architectureversion));
 122         dumplen = dtoh64(h->dumplength);
 123         xo_emit_h(xo, "{P:  }{Lwc:Dump Length}{:dump_length_bytes/%lld}\n",
 124             (long long)dumplen);
 125         xo_emit_h(xo, "{P:  }{Lwc:Blocksize}{:blocksize/%d}\n",
 126             dtoh32(h->blocksize));
 127         switch (h->compression) {
 128         case KERNELDUMP_COMP_NONE:
 129                 comp_str = "none";
 130                 break;
 131         case KERNELDUMP_COMP_GZIP:
 132                 comp_str = "gzip";
 133                 break;
 134         case KERNELDUMP_COMP_ZSTD:
 135                 comp_str = "zstd";
 136                 break;
 137         default:
 138                 comp_str = "???";
 139                 break;
 140         }
 141         xo_emit_h(xo, "{P:  }{Lwc:Compression}{:compression/%s}\n", comp_str);
 142         t = dtoh64(h->dumptime);
 143         xo_emit_h(xo, "{P:  }{Lwc:Dumptime}{:dumptime/%s}", ctime(&t));
 144         xo_emit_h(xo, "{P:  }{Lwc:Hostname}{:hostname/%s}\n", h->hostname);
 145         xo_emit_h(xo, "{P:  }{Lwc:Magic}{:magic/%s}\n", h->magic);
 146         xo_emit_h(xo, "{P:  }{Lwc:Version String}{:version_string/%s}",
 147             h->versionstring);
 148         xo_emit_h(xo, "{P:  }{Lwc:Panic String}{:panic_string/%s}\n",
 149             h->panicstring);
 150         xo_emit_h(xo, "{P:  }{Lwc:Dump Parity}{:dump_parity/%u}\n", h->parity);
 151         xo_emit_h(xo, "{P:  }{Lwc:Bounds}{:bounds/%d}\n", bounds);
 152
 153         switch (status) {
 154         case STATUS_BAD:
 155                 stat_str = "bad";
 156                 break;
 157         case STATUS_GOOD:
 158                 stat_str = "good";
 159                 break;
 160         default:
 161                 stat_str = "unknown";
 162                 break;
 163         }
 164         xo_emit_h(xo, "{P:  }{Lwc:Dump Status}{:dump_status/%s}\n", stat_str);
 165         xo_flush_h(xo);
 166 }
 167
 168 static int
 169 getbounds(void)
 170 {
 171         FILE *fp;
 172         char buf[6];
 173         int ret;
 174
 175         /*
 176          * If we are just checking, then we haven't done a chdir to the dump
 177          * directory and we should not try to read a bounds file.
 178          */
 179         if (checkfor)
 180                 return (0);
 181
 182         ret = 0;
 183
 184         if ((fp = fopen("bounds", "r")) == NULL) {
 185                 if (verbose)
 186                         printf("unable to open bounds file, using 0\n");
 187                 return (ret);
 188         }
 189
 190         if (fgets(buf, sizeof buf, fp) == NULL) {
 191                 if (feof(fp))
 192                         syslog(LOG_WARNING, "bounds file is empty, using 0");
 193                 else
 194                         syslog(LOG_WARNING, "bounds file: %s", strerror(errno));
 195                 fclose(fp);
 196                 return (ret);
 197         }
 198
 199         errno = 0;
 200         ret = (int)strtol(buf, NULL, 10);
 201         if (ret == 0 && (errno == EINVAL || errno == ERANGE))
 202                 syslog(LOG_WARNING, "invalid value found in bounds, using 0");
 203         fclose(fp);
 204         return (ret);
 205 }
 206
 207 static void
 208 writebounds(int bounds)
 209 {
 210         FILE *fp;
 211
 212         if ((fp = fopen("bounds", "w")) == NULL) {
 213                 syslog(LOG_WARNING, "unable to write to bounds file: %m");
 214                 return;
 215         }
 216
 217         if (verbose)
 218                 printf("bounds number: %d\n", bounds);
 219
 220         fprintf(fp, "%d\n", bounds);
 221         fclose(fp);
 222 }
 223
 224 static bool
 225 writekey(const char *keyname, uint8_t *dumpkey, uint32_t dumpkeysize)
 226 {
 227         int fd;
 228
 229         fd = open(keyname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 230         if (fd == -1) {
 231                 syslog(LOG_ERR, "Unable to open %s to write the key: %m.",
 232                     keyname);
 233                 return (false);
 234         }
 235
 236         if (write(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
 237                 syslog(LOG_ERR, "Unable to write the key to %s: %m.", keyname);
 238                 close(fd);
 239                 return (false);
 240         }
 241
 242         close(fd);
 243         return (true);
 244 }
 245
 246 static off_t
 247 file_size(const char *path)
 248 {
 249         struct stat sb;
 250
 251         /* Ignore all errors, those file may not exists. */
 252         if (stat(path, &sb) == -1)
 253                 return (0);
 254         return (sb.st_size);
 255 }
 256
 257 static off_t
 258 saved_dump_size(int bounds)
 259 {
 260         static char path[PATH_MAX];
 261         off_t dumpsize;
 262
 263         dumpsize = 0;
 264
 265         (void)snprintf(path, sizeof(path), "info.%d", bounds);
 266         dumpsize += file_size(path);
 267         (void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
 268         dumpsize += file_size(path);
 269         (void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
 270         dumpsize += file_size(path);
 271         (void)snprintf(path, sizeof(path), "vmcore.%d.zst", bounds);
 272         dumpsize += file_size(path);
 273         (void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
 274         dumpsize += file_size(path);
 275         (void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
 276         dumpsize += file_size(path);
 277
 278         return (dumpsize);
 279 }
 280
 281 static void
 282 saved_dump_remove(int bounds)
 283 {
 284         static char path[PATH_MAX];
 285
 286         (void)snprintf(path, sizeof(path), "info.%d", bounds);
 287         (void)unlink(path);
 288         (void)snprintf(path, sizeof(path), "vmcore.%d", bounds);
 289         (void)unlink(path);
 290         (void)snprintf(path, sizeof(path), "vmcore.%d.gz", bounds);
 291         (void)unlink(path);
 292         (void)snprintf(path, sizeof(path), "vmcore.%d.zst", bounds);
 293         (void)unlink(path);
 294         (void)snprintf(path, sizeof(path), "textdump.tar.%d", bounds);
 295         (void)unlink(path);
 296         (void)snprintf(path, sizeof(path), "textdump.tar.%d.gz", bounds);
 297         (void)unlink(path);
 298 }
 299
 300 static void
 301 symlinks_remove(void)
 302 {
 303
 304         (void)unlink("info.last");
 305         (void)unlink("key.last");
 306         (void)unlink("vmcore.last");
 307         (void)unlink("vmcore.last.gz");
 308         (void)unlink("vmcore.last.zst");
 309         (void)unlink("vmcore_encrypted.last");
 310         (void)unlink("vmcore_encrypted.last.gz");
 311         (void)unlink("textdump.tar.last");
 312         (void)unlink("textdump.tar.last.gz");
 313 }
 314
 315 /*
 316  * Check that sufficient space is available on the disk that holds the
 317  * save directory.
 318  */
 319 static int
 320 check_space(const char *savedir, off_t dumpsize, int bounds)
 321 {
 322         FILE *fp;
 323         off_t available, minfree, spacefree, totfree, needed;
 324         struct statfs fsbuf;
 325         char buf[100];
 326
 327         if (statfs(".", &fsbuf) < 0) {
 328                 syslog(LOG_ERR, "%s: %m", savedir);
 329                 exit(1);
 330         }
 331         spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
 332         totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
 333
 334         if ((fp = fopen("minfree", "r")) == NULL)
 335                 minfree = 0;
 336         else {
 337                 if (fgets(buf, sizeof(buf), fp) == NULL)
 338                         minfree = 0;
 339                 else {
 340                         char *endp;
 341
 342                         errno = 0;
 343                         minfree = strtoll(buf, &endp, 10);
 344                         if (minfree == 0 && errno != 0)
 345                                 minfree = -1;
 346                         else {
 347                                 while (*endp != '\0' && isspace(*endp))
 348                                         endp++;
 349                                 if (*endp != '\0' || minfree < 0)
 350                                         minfree = -1;
 351                         }
 352                         if (minfree < 0)
 353                                 syslog(LOG_WARNING,
 354                                     "`minfree` didn't contain a valid size "
 355                                     "(`%s`). Defaulting to 0", buf);
 356                 }
 357                 (void)fclose(fp);
 358         }
 359
 360         available = minfree > 0 ? spacefree - minfree : totfree;
 361         needed = dumpsize / 1024 + 2;   /* 2 for info file */
 362         needed -= saved_dump_size(bounds);
 363         if (available < needed) {
 364                 syslog(LOG_WARNING,
 365                     "no dump: not enough free space on device (need at least "
 366                     "%jdkB for dump; %jdkB available; %jdkB reserved)",
 367                     (intmax_t)needed,
 368                     (intmax_t)available + minfree,
 369                     (intmax_t)minfree);
 370                 return (0);
 371         }
 372         if (spacefree - needed < 0)
 373                 syslog(LOG_WARNING,
 374                     "dump performed, but free space threshold crossed");
 375         return (1);
 376 }
 377
 378 static bool
 379 compare_magic(const struct kerneldumpheader *kdh, const char *magic)
 380 {
 381
 382         return (strncmp(kdh->magic, magic, sizeof(kdh->magic)) == 0);
 383 }
 384
 385 #define BLOCKSIZE (1<<12)
 386 #define BLOCKMASK (~(BLOCKSIZE-1))
 387
 388 static int
 389 DoRegularFile(int fd, off_t dumpsize, u_int sectorsize, bool sparse, char *buf,
 390     const char *device, const char *filename, FILE *fp)
 391 {
 392         int he, hs, nr, nw, wl;
 393         off_t dmpcnt, origsize;
 394
 395         dmpcnt = 0;
 396         origsize = dumpsize;
 397         he = 0;
 398         while (dumpsize > 0) {
 399                 wl = BUFFERSIZE;
 400                 if (wl > dumpsize)
 401                         wl = dumpsize;
 402                 nr = read(fd, buf, roundup(wl, sectorsize));
 403                 if (nr != (int)roundup(wl, sectorsize)) {
 404                         if (nr == 0)
 405                                 syslog(LOG_WARNING,
 406                                     "WARNING: EOF on dump device");
 407                         else
 408                                 syslog(LOG_ERR, "read error on %s: %m", device);
 409                         nerr++;
 410                         return (-1);
 411                 }
 412                 if (!sparse) {
 413                         nw = fwrite(buf, 1, wl, fp);
 414                 } else {
 415                         for (nw = 0; nw < nr; nw = he) {
 416                                 /* find a contiguous block of zeroes */
 417                                 for (hs = nw; hs < nr; hs += BLOCKSIZE) {
 418                                         for (he = hs; he < nr && buf[he] == 0;
 419                                             ++he)
 420                                                 /* nothing */ ;
 421                                         /* is the hole long enough to matter? */
 422                                         if (he >= hs + BLOCKSIZE)
 423                                                 break;
 424                                 }
 425
 426                                 /* back down to a block boundary */
 427                                 he &= BLOCKMASK;
 428
 429                                 /*
 430                                  * 1) Don't go beyond the end of the buffer.
 431                                  * 2) If the end of the buffer is less than
 432                                  *    BLOCKSIZE bytes away, we're at the end
 433                                  *    of the file, so just grab what's left.
 434                                  */
 435                                 if (hs + BLOCKSIZE > nr)
 436                                         hs = he = nr;
 437
 438                                 /*
 439                                  * At this point, we have a partial ordering:
 440                                  *     nw <= hs <= he <= nr
 441                                  * If hs > nw, buf[nw..hs] contains non-zero
 442                                  * data. If he > hs, buf[hs..he] is all zeroes.
 443                                  */
 444                                 if (hs > nw)
 445                                         if (fwrite(buf + nw, hs - nw, 1, fp)
 446                                             != 1)
 447                                         break;
 448                                 if (he > hs)
 449                                         if (fseeko(fp, he - hs, SEEK_CUR) == -1)
 450                                                 break;
 451                         }
 452                 }
 453                 if (nw != wl) {
 454                         syslog(LOG_ERR,
 455                             "write error on %s file: %m", filename);
 456                         syslog(LOG_WARNING,
 457                             "WARNING: vmcore may be incomplete");
 458                         nerr++;
 459                         return (-1);
 460                 }
 461                 if (verbose) {
 462                         dmpcnt += wl;
 463                         printf("%llu\r", (unsigned long long)dmpcnt);
 464                         fflush(stdout);
 465                 }
 466                 dumpsize -= wl;
 467                 if (got_siginfo) {
 468                         printf("%s %.1lf%%\n", filename, (100.0 - (100.0 *
 469                             (double)dumpsize / (double)origsize)));
 470                         got_siginfo = 0;
 471                 }
 472         }
 473         return (0);
 474 }
 475
 476 /*
 477  * Specialized version of dump-reading logic for use with textdumps, which
 478  * are written backwards from the end of the partition, and must be reversed
 479  * before being written to the file.  Textdumps are small, so do a bit less
 480  * work to optimize/sparsify.
 481  */
 482 static int
 483 DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
 484     const char *device, const char *filename, FILE *fp)
 485 {
 486         int nr, nw, wl;
 487         off_t dmpcnt, totsize;
 488
 489         totsize = dumpsize;
 490         dmpcnt = 0;
 491         wl = 512;
 492         if ((dumpsize % wl) != 0) {
 493                 syslog(LOG_ERR, "textdump uneven multiple of 512 on %s",
 494                     device);
 495                 nerr++;
 496                 return (-1);
 497         }
 498         while (dumpsize > 0) {
 499                 nr = pread(fd, buf, wl, lasthd - (totsize - dumpsize) - wl);
 500                 if (nr != wl) {
 501                         if (nr == 0)
 502                                 syslog(LOG_WARNING,
 503                                     "WARNING: EOF on dump device");
 504                         else
 505                                 syslog(LOG_ERR, "read error on %s: %m", device);
 506                         nerr++;
 507                         return (-1);
 508                 }
 509                 nw = fwrite(buf, 1, wl, fp);
 510                 if (nw != wl) {
 511                         syslog(LOG_ERR,
 512                             "write error on %s file: %m", filename);
 513                         syslog(LOG_WARNING,
 514                             "WARNING: textdump may be incomplete");
 515                         nerr++;
 516                         return (-1);
 517                 }
 518                 if (verbose) {
 519                         dmpcnt += wl;
 520                         printf("%llu\r", (unsigned long long)dmpcnt);
 521                         fflush(stdout);
 522                 }
 523                 dumpsize -= wl;
 524         }
 525         return (0);
 526 }
 527
 528 static void
 529 DoFile(const char *savedir, const char *device)
 530 {
 531         xo_handle_t *xostdout, *xoinfo;
 532         static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
 533         static char keyname[PATH_MAX];
 534         static char *buf = NULL;
 535         char *temp = NULL;
 536         struct kerneldumpheader kdhf, kdhl;
 537         uint8_t *dumpkey;
 538         off_t mediasize, dumpextent, dumplength, firsthd, lasthd;
 539         FILE *info, *fp;
 540         mode_t oumask;
 541         int fd, fdinfo, error;
 542         int bounds, status;
 543         u_int sectorsize, xostyle;
 544         uint32_t dumpkeysize;
 545         bool iscompressed, isencrypted, istextdump, ret;
 546
 547         bounds = getbounds();
 548         dumpkey = NULL;
 549         mediasize = 0;
 550         status = STATUS_UNKNOWN;
 551
 552         xostdout = xo_create_to_file(stdout, XO_STYLE_TEXT, 0);
 553         if (xostdout == NULL) {
 554                 syslog(LOG_ERR, "%s: %m", infoname);
 555                 return;
 556         }
 557
 558         if (maxdumps > 0 && bounds == maxdumps)
 559                 bounds = 0;
 560
 561         if (buf == NULL) {
 562                 buf = malloc(BUFFERSIZE);
 563                 if (buf == NULL) {
 564                         syslog(LOG_ERR, "%m");
 565                         return;
 566                 }
 567         }
 568
 569         if (verbose)
 570                 printf("checking for kernel dump on device %s\n", device);
 571
 572         fd = open(device, (checkfor || keep) ? O_RDONLY : O_RDWR);
 573         if (fd < 0) {
 574                 syslog(LOG_ERR, "%s: %m", device);
 575                 return;
 576         }
 577
 578         error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
 579         if (!error)
 580                 error = ioctl(fd, DIOCGSECTORSIZE, &sectorsize);
 581         if (error) {
 582                 syslog(LOG_ERR,
 583                     "couldn't find media and/or sector size of %s: %m", device);
 584                 goto closefd;
 585         }
 586
 587         if (verbose) {
 588                 printf("mediasize = %lld bytes\n", (long long)mediasize);
 589                 printf("sectorsize = %u bytes\n", sectorsize);
 590         }
 591
 592         if (sectorsize < sizeof(kdhl)) {
 593                 syslog(LOG_ERR,
 594                     "Sector size is less the kernel dump header %zu",
 595                     sizeof(kdhl));
 596                 goto closefd;
 597         }
 598
 599         lasthd = mediasize - sectorsize;
 600         temp = malloc(sectorsize);
 601         if (temp == NULL) {
 602                 syslog(LOG_ERR, "%m");
 603                 goto closefd;
 604         }
 605         if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
 606             read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
 607                 syslog(LOG_ERR,
 608                     "error reading last dump header at offset %lld in %s: %m",
 609                     (long long)lasthd, device);
 610                 goto closefd;
 611         }
 612         memcpy(&kdhl, temp, sizeof(kdhl));
 613         iscompressed = istextdump = false;
 614         if (compare_magic(&kdhl, TEXTDUMPMAGIC)) {
 615                 if (verbose)
 616                         printf("textdump magic on last dump header on %s\n",
 617                             device);
 618                 istextdump = true;
 619                 if (dtoh32(kdhl.version) != KERNELDUMP_TEXT_VERSION) {
 620                         syslog(LOG_ERR,
 621                             "unknown version (%d) in last dump header on %s",
 622                             dtoh32(kdhl.version), device);
 623
 624                         status = STATUS_BAD;
 625                         if (force == 0)
 626                                 goto closefd;
 627                 }
 628         } else if (compare_magic(&kdhl, KERNELDUMPMAGIC)) {
 629                 if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
 630                         syslog(LOG_ERR,
 631                             "unknown version (%d) in last dump header on %s",
 632                             dtoh32(kdhl.version), device);
 633
 634                         status = STATUS_BAD;
 635                         if (force == 0)
 636                                 goto closefd;
 637                 }
 638                 switch (kdhl.compression) {
 639                 case KERNELDUMP_COMP_NONE:
 640                         break;
 641                 case KERNELDUMP_COMP_GZIP:
 642                 case KERNELDUMP_COMP_ZSTD:
 643                         if (compress && verbose)
 644                                 printf("dump is already compressed\n");
 645                         compress = false;
 646                         iscompressed = true;
 647                         break;
 648                 default:
 649                         syslog(LOG_ERR, "unknown compression type %d on %s",
 650                             kdhl.compression, device);
 651                         break;
 652                 }
 653         } else {
 654                 if (verbose)
 655                         printf("magic mismatch on last dump header on %s\n",
 656                             device);
 657
 658                 status = STATUS_BAD;
 659                 if (force == 0)
 660                         goto closefd;
 661
 662                 if (compare_magic(&kdhl, KERNELDUMPMAGIC_CLEARED)) {
 663                         if (verbose)
 664                                 printf("forcing magic on %s\n", device);
 665                         memcpy(kdhl.magic, KERNELDUMPMAGIC, sizeof(kdhl.magic));
 666                 } else {
 667                         syslog(LOG_ERR, "unable to force dump - bad magic");
 668                         goto closefd;
 669                 }
 670                 if (dtoh32(kdhl.version) != KERNELDUMPVERSION) {
 671                         syslog(LOG_ERR,
 672                             "unknown version (%d) in last dump header on %s",
 673                             dtoh32(kdhl.version), device);
 674
 675                         status = STATUS_BAD;
 676                         if (force == 0)
 677                                 goto closefd;
 678                 }
 679         }
 680
 681         nfound++;
 682         if (clear)
 683                 goto nuke;
 684
 685         if (kerneldump_parity(&kdhl)) {
 686                 syslog(LOG_ERR,
 687                     "parity error on last dump header on %s", device);
 688                 nerr++;
 689                 status = STATUS_BAD;
 690                 if (force == 0)
 691                         goto closefd;
 692         }
 693         dumpextent = dtoh64(kdhl.dumpextent);
 694         dumplength = dtoh64(kdhl.dumplength);
 695         dumpkeysize = dtoh32(kdhl.dumpkeysize);
 696         firsthd = lasthd - dumpextent - sectorsize - dumpkeysize;
 697         if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
 698             read(fd, temp, sectorsize) != (ssize_t)sectorsize) {
 699                 syslog(LOG_ERR,
 700                     "error reading first dump header at offset %lld in %s: %m",
 701                     (long long)firsthd, device);
 702                 nerr++;
 703                 goto closefd;
 704         }
 705         memcpy(&kdhf, temp, sizeof(kdhf));
 706
 707         if (verbose >= 2) {
 708                 printf("First dump headers:\n");
 709                 printheader(xostdout, &kdhf, device, bounds, -1);
 710
 711                 printf("\nLast dump headers:\n");
 712                 printheader(xostdout, &kdhl, device, bounds, -1);
 713                 printf("\n");
 714         }
 715
 716         if (memcmp(&kdhl, &kdhf, sizeof(kdhl))) {
 717                 syslog(LOG_ERR,
 718                     "first and last dump headers disagree on %s", device);
 719                 nerr++;
 720                 status = STATUS_BAD;
 721                 if (force == 0)
 722                         goto closefd;
 723         } else {
 724                 status = STATUS_GOOD;
 725         }
 726
 727         if (checkfor) {
 728                 printf("A dump exists on %s\n", device);
 729                 close(fd);
 730                 exit(0);
 731         }
 732
 733         if (kdhl.panicstring[0] != '\0')
 734                 syslog(LOG_ALERT, "reboot after panic: %.*s",
 735                     (int)sizeof(kdhl.panicstring), kdhl.panicstring);
 736         else
 737                 syslog(LOG_ALERT, "reboot");
 738
 739         if (verbose)
 740                 printf("Checking for available free space\n");
 741
 742         if (!check_space(savedir, dumplength, bounds)) {
 743                 nerr++;
 744                 goto closefd;
 745         }
 746
 747         writebounds(bounds + 1);
 748
 749         saved_dump_remove(bounds);
 750
 751         snprintf(infoname, sizeof(infoname), "info.%d", bounds);
 752
 753         /*
 754          * Create or overwrite any existing dump header files.
 755          */
 756         fdinfo = open(infoname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 757         if (fdinfo < 0) {
 758                 syslog(LOG_ERR, "%s: %m", infoname);
 759                 nerr++;
 760                 goto closefd;
 761         }
 762
 763         oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file. */
 764         isencrypted = (dumpkeysize > 0);
 765         if (compress) {
 766                 snprintf(corename, sizeof(corename), "%s.%d.gz",
 767                     istextdump ? "textdump.tar" :
 768                     (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
 769                 fp = zopen(corename, "w");
 770         } else if (iscompressed && !isencrypted) {
 771                 snprintf(corename, sizeof(corename), "vmcore.%d.%s", bounds,
 772                     (kdhl.compression == KERNELDUMP_COMP_GZIP) ? "gz" : "zst");
 773                 fp = fopen(corename, "w");
 774         } else {
 775                 snprintf(corename, sizeof(corename), "%s.%d",
 776                     istextdump ? "textdump.tar" :
 777                     (isencrypted ? "vmcore_encrypted" : "vmcore"), bounds);
 778                 fp = fopen(corename, "w");
 779         }
 780         if (fp == NULL) {
 781                 syslog(LOG_ERR, "%s: %m", corename);
 782                 close(fdinfo);
 783                 nerr++;
 784                 goto closefd;
 785         }
 786         (void)umask(oumask);
 787
 788         info = fdopen(fdinfo, "w");
 789
 790         if (info == NULL) {
 791                 syslog(LOG_ERR, "fdopen failed: %m");
 792                 nerr++;
 793                 goto closeall;
 794         }
 795
 796         xostyle = xo_get_style(NULL);
 797         xoinfo = xo_create_to_file(info, xostyle, 0);
 798         if (xoinfo == NULL) {
 799                 syslog(LOG_ERR, "%s: %m", infoname);
 800                 nerr++;
 801                 goto closeall;
 802         }
 803         xo_open_container_h(xoinfo, "crashdump");
 804
 805         if (verbose)
 806                 printheader(xostdout, &kdhl, device, bounds, status);
 807
 808         printheader(xoinfo, &kdhl, device, bounds, status);
 809         xo_close_container_h(xoinfo, "crashdump");
 810         xo_flush_h(xoinfo);
 811         xo_finish_h(xoinfo);
 812         fclose(info);
 813
 814         if (isencrypted) {
 815                 dumpkey = calloc(1, dumpkeysize);
 816                 if (dumpkey == NULL) {
 817                         syslog(LOG_ERR, "Unable to allocate kernel dump key.");
 818                         nerr++;
 819                         goto closeall;
 820                 }
 821
 822                 if (read(fd, dumpkey, dumpkeysize) != (ssize_t)dumpkeysize) {
 823                         syslog(LOG_ERR, "Unable to read kernel dump key: %m.");
 824                         nerr++;
 825                         goto closeall;
 826                 }
 827
 828                 snprintf(keyname, sizeof(keyname), "key.%d", bounds);
 829                 ret = writekey(keyname, dumpkey, dumpkeysize);
 830                 explicit_bzero(dumpkey, dumpkeysize);
 831                 if (!ret) {
 832                         nerr++;
 833                         goto closeall;
 834                 }
 835         }
 836
 837         syslog(LOG_NOTICE, "writing %s%score to %s/%s",
 838             isencrypted ? "encrypted " : "", compress ? "compressed " : "",
 839             savedir, corename);
 840
 841         if (istextdump) {
 842                 if (DoTextdumpFile(fd, dumplength, lasthd, buf, device,
 843                     corename, fp) < 0)
 844                         goto closeall;
 845         } else {
 846                 if (DoRegularFile(fd, dumplength, sectorsize,
 847                     !(compress || iscompressed || isencrypted), buf, device,
 848                     corename, fp) < 0) {
 849                         goto closeall;
 850                 }
 851         }
 852         if (verbose)
 853                 printf("\n");
 854
 855         if (fclose(fp) < 0) {
 856                 syslog(LOG_ERR, "error on %s: %m", corename);
 857                 nerr++;
 858                 goto closefd;
 859         }
 860
 861         symlinks_remove();
 862         if (symlink(infoname, "info.last") == -1) {
 863                 syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
 864                     savedir, "info.last");
 865         }
 866         if (isencrypted) {
 867                 if (symlink(keyname, "key.last") == -1) {
 868                         syslog(LOG_WARNING,
 869                             "unable to create symlink %s/%s: %m", savedir,
 870                             "key.last");
 871                 }
 872         }
 873         if (compress || iscompressed) {
 874                 snprintf(linkname, sizeof(linkname), "%s.last.%s",
 875                     istextdump ? "textdump.tar" :
 876                     (isencrypted ? "vmcore_encrypted" : "vmcore"),
 877                     (kdhl.compression == KERNELDUMP_COMP_ZSTD) ? "zst" : "gz");
 878         } else {
 879                 snprintf(linkname, sizeof(linkname), "%s.last",
 880                     istextdump ? "textdump.tar" :
 881                     (isencrypted ? "vmcore_encrypted" : "vmcore"));
 882         }
 883         if (symlink(corename, linkname) == -1) {
 884                 syslog(LOG_WARNING, "unable to create symlink %s/%s: %m",
 885                     savedir, linkname);
 886         }
 887
 888         nsaved++;
 889
 890         if (verbose)
 891                 printf("dump saved\n");
 892
 893 nuke:
 894         if (!keep) {
 895                 if (verbose)
 896                         printf("clearing dump header\n");
 897                 memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof(kdhl.magic));
 898                 memcpy(temp, &kdhl, sizeof(kdhl));
 899                 if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
 900                     write(fd, temp, sectorsize) != (ssize_t)sectorsize)
 901                         syslog(LOG_ERR,
 902                             "error while clearing the dump header: %m");
 903         }
 904         xo_close_container_h(xostdout, "crashdump");
 905         xo_finish_h(xostdout);
 906         free(dumpkey);
 907         free(temp);
 908         close(fd);
 909         return;
 910
 911 closeall:
 912         fclose(fp);
 913
 914 closefd:
 915         free(dumpkey);
 916         free(temp);
 917         close(fd);
 918 }
 919
 920 static void
 921 usage(void)
 922 {
 923         xo_error("%s\n%s\n%s\n",
 924             "usage: savecore -c [-v] [device ...]",
 925             "       savecore -C [-v] [device ...]",
 926             "       savecore [-fkvz] [-m maxdumps] [directory [device ...]]");
 927         exit(1);
 928 }
 929
 930 int
 931 main(int argc, char **argv)
 932 {
 933         const char *savedir = ".";
 934         struct fstab *fsp;
 935         int i, ch, error;
 936
 937         checkfor = compress = clear = force = keep = verbose = 0;
 938         nfound = nsaved = nerr = 0;
 939
 940         openlog("savecore", LOG_PERROR, LOG_DAEMON);
 941         signal(SIGINFO, infohandler);
 942
 943         argc = xo_parse_args(argc, argv);
 944         if (argc < 0)
 945                 exit(1);
 946
 947         while ((ch = getopt(argc, argv, "Ccfkm:vz")) != -1)
 948                 switch(ch) {
 949                 case 'C':
 950                         checkfor = 1;
 951                         break;
 952                 case 'c':
 953                         clear = 1;
 954                         break;
 955                 case 'f':
 956                         force = 1;
 957                         break;
 958                 case 'k':
 959                         keep = 1;
 960                         break;
 961                 case 'm':
 962                         maxdumps = atoi(optarg);
 963                         if (maxdumps <= 0) {
 964                                 syslog(LOG_ERR, "Invalid maxdump value");
 965                                 exit(1);
 966                         }
 967                         break;
 968                 case 'v':
 969                         verbose++;
 970                         break;
 971                 case 'z':
 972                         compress = 1;
 973                         break;
 974                 case '?':
 975                 default:
 976                         usage();
 977                 }
 978         if (checkfor && (clear || force || keep))
 979                 usage();
 980         if (clear && (compress || keep))
 981                 usage();
 982         if (maxdumps > 0 && (checkfor || clear))
 983                 usage();
 984         argc -= optind;
 985         argv += optind;
 986         if (argc >= 1 && !checkfor && !clear) {
 987                 error = chdir(argv[0]);
 988                 if (error) {
 989                         syslog(LOG_ERR, "chdir(%s): %m", argv[0]);
 990                         exit(1);
 991                 }
 992                 savedir = argv[0];
 993                 argc--;
 994                 argv++;
 995         }
 996         if (argc == 0) {
 997                 for (;;) {
 998                         fsp = getfsent();
 999                         if (fsp == NULL)
1000                                 break;
1001                         if (strcmp(fsp->fs_vfstype, "swap") &&
1002                             strcmp(fsp->fs_vfstype, "dump"))
1003                                 continue;
1004                         DoFile(savedir, fsp->fs_spec);
1005                 }
1006                 endfsent();
1007         } else {
1008                 for (i = 0; i < argc; i++)
1009                         DoFile(savedir, argv[i]);
1010         }
1011
1012         /* Emit minimal output. */
1013         if (nfound == 0) {
1014                 if (checkfor) {
1015                         if (verbose)
1016                                 printf("No dump exists\n");
1017                         exit(1);
1018                 }
1019                 if (verbose)
1020                         syslog(LOG_WARNING, "no dumps found");
1021         } else if (nsaved == 0) {
1022                 if (nerr != 0) {
1023                         if (verbose)
1024                                 syslog(LOG_WARNING,
1025                                     "unsaved dumps found but not saved");
1026                         exit(1);
1027                 } else if (verbose)
1028                         syslog(LOG_WARNING, "no unsaved dumps found");
1029         }
1030
1031         return (0);
1032 }
1033
1034 static void
1035 infohandler(int sig __unused)
1036 {
1037         got_siginfo = 1;
1038 }