1 /* 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2008 Luigi Rizzo 5 * Copyright (c) 1999 Robert Nordier 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 23 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 24 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 26 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 27 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #include <sys/param.h> 32 #include <sys/disklabel.h> 33 #include <sys/diskmbr.h> 34 #include <sys/stat.h> 35 36 #include <err.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <libgeom.h> 40 #include <paths.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #define MBRSIZE 512 /* master boot record size */ 47 48 #define OFF_VERSION 0x1b0 /* offset: version number, only boot0version */ 49 #define OFF_SERIAL 0x1b8 /* offset: volume serial number */ 50 #define OFF_PTBL 0x1be /* offset: partition table */ 51 #define OFF_MAGIC 0x1fe /* offset: magic number */ 52 /* 53 * Offsets to the parameters of the 512-byte boot block. 54 * For historical reasons they are set as macros 55 */ 56 struct opt_offsets { 57 int opt; 58 int drive; 59 int flags; 60 int ticks; 61 }; 62 63 static struct opt_offsets b0_ofs[] = { 64 { 0x0, 0x0, 0x0, 0x0 }, /* no boot block */ 65 { 0x1b9, 0x1ba, 0x1bb, 0x1bc }, /* original block */ 66 { 0x1b5, 0x1b6, 0x1b7, 0x1bc }, /* NT_SERIAL block */ 67 }; 68 69 static int b0_ver; /* boot block version set by boot0bs */ 70 71 #define OFF_OPT (b0_ofs[b0_ver].opt) /* default boot option */ 72 #define OFF_DRIVE (b0_ofs[b0_ver].drive) /* setdrv drive */ 73 #define OFF_FLAGS (b0_ofs[b0_ver].flags) /* option flags */ 74 #define OFF_TICKS (b0_ofs[b0_ver].ticks) /* clock ticks */ 75 76 77 #define cv2(p) ((p)[0] | (p)[1] << 010) 78 79 #define mk2(p, x) \ 80 (p)[0] = (u_int8_t)(x), \ 81 (p)[1] = (u_int8_t)((x) >> 010) 82 83 static const struct { 84 const char *tok; 85 int def; 86 } opttbl[] = { 87 {"packet", 0}, 88 {"update", 1}, 89 {"setdrv", 0} 90 }; 91 static const int nopt = nitems(opttbl); 92 93 static const char fmt0[] = "# flag start chs type" 94 " end chs offset size\n"; 95 96 static const char fmt1[] = "%d 0x%02x %4u:%3u:%2u 0x%02x" 97 " %4u:%3u:%2u %10u %10u\n"; 98 99 static int geom_class_available(const char *); 100 static int read_mbr(const char *, u_int8_t **, int); 101 static void write_mbr(const char *, int, u_int8_t *, int, int); 102 static void display_mbr(u_int8_t *); 103 static int boot0version(const u_int8_t *); 104 static int boot0bs(const u_int8_t *); 105 static void stropt(const char *, int *, int *); 106 static int argtoi(const char *, int, int, int); 107 static int set_bell(u_int8_t *, int, int); 108 static void usage(void) __dead2; 109 110 static unsigned vol_id[5]; /* 4 plus 1 for flag */ 111 112 static int v_flag; 113 /* 114 * Boot manager installation/configuration utility. 115 */ 116 int 117 main(int argc, char *argv[]) 118 { 119 u_int8_t *mbr, *boot0; 120 int boot0_size, mbr_size; 121 const char *bpath, *fpath; 122 char *disk; 123 int B_flag, o_flag; 124 int d_arg, m_arg, s_arg, t_arg; 125 int o_and, o_or, o_e = -1; 126 int up, c; 127 128 bpath = "/boot/boot0"; 129 fpath = NULL; 130 B_flag = v_flag = o_flag = 0; 131 d_arg = m_arg = s_arg = t_arg = -1; 132 o_and = 0xff; 133 o_or = 0; 134 while ((c = getopt(argc, argv, "Bvb:d:e:f:i:m:o:s:t:")) != -1) 135 switch (c) { 136 case 'B': 137 B_flag = 1; 138 break; 139 case 'v': 140 v_flag = 1; 141 break; 142 case 'b': 143 bpath = optarg; 144 break; 145 case 'd': 146 d_arg = argtoi(optarg, 0, 0xff, 'd'); 147 break; 148 case 'e': 149 if (optarg[0] == '0' && optarg[1] == 'x') 150 sscanf(optarg, "0x%02x", &o_e); 151 else 152 o_e = optarg[0]; 153 break; 154 case 'f': 155 fpath = optarg; 156 break; 157 case 'i': 158 if (sscanf(optarg, "%02x%02x-%02x%02x", 159 vol_id, vol_id+1, vol_id+2, vol_id+3) == 4) 160 vol_id[4] = 1; 161 else 162 errx(1, "bad argument %s", optarg); 163 break; 164 case 'm': 165 m_arg = argtoi(optarg, 0, 0xf, 'm'); 166 break; 167 case 'o': 168 stropt(optarg, &o_and, &o_or); 169 o_flag = 1; 170 break; 171 case 's': 172 if (strcasecmp(optarg, "pxe") == 0) 173 s_arg = 6; 174 else 175 s_arg = argtoi(optarg, 1, 6, 's'); 176 break; 177 case 't': 178 t_arg = argtoi(optarg, 1, 0xffff, 't'); 179 break; 180 default: 181 usage(); 182 } 183 argc -= optind; 184 argv += optind; 185 if (argc != 1) 186 usage(); 187 disk = g_device_path(*argv); 188 if (disk == NULL) 189 errx(1, "Unable to get providername for %s\n", *argv); 190 up = B_flag || d_arg != -1 || m_arg != -1 || o_flag || s_arg != -1 191 || t_arg != -1; 192 193 /* open the disk and read in the existing mbr. Either here or 194 * when reading the block from disk, we do check for the version 195 * and abort if a suitable block is not found. 196 */ 197 mbr_size = read_mbr(disk, &mbr, !B_flag); 198 199 /* save the existing MBR if we are asked to do so */ 200 if (fpath) 201 write_mbr(fpath, O_CREAT | O_TRUNC, mbr, mbr_size, 0); 202 203 /* 204 * If we are installing the boot loader, read it from disk and copy the 205 * slice table over from the existing MBR. If not, then point boot0 206 * back at the MBR we just read in. After this, boot0 is the data to 207 * write back to disk if we are going to do a write. 208 */ 209 if (B_flag) { 210 boot0_size = read_mbr(bpath, &boot0, 1); 211 memcpy(boot0 + OFF_PTBL, mbr + OFF_PTBL, 212 sizeof(struct dos_partition) * NDOSPART); 213 if (b0_ver == 2) /* volume serial number support */ 214 memcpy(boot0 + OFF_SERIAL, mbr + OFF_SERIAL, 4); 215 } else { 216 boot0 = mbr; 217 boot0_size = mbr_size; 218 } 219 220 /* set the drive */ 221 if (d_arg != -1) 222 boot0[OFF_DRIVE] = d_arg; 223 224 /* set various flags */ 225 if (m_arg != -1) { 226 boot0[OFF_FLAGS] &= 0xf0; 227 boot0[OFF_FLAGS] |= m_arg; 228 } 229 if (o_flag) { 230 boot0[OFF_FLAGS] &= o_and; 231 boot0[OFF_FLAGS] |= o_or; 232 } 233 234 /* set the default boot selection */ 235 if (s_arg != -1) 236 boot0[OFF_OPT] = s_arg - 1; 237 238 /* set the timeout */ 239 if (t_arg != -1) 240 mk2(boot0 + OFF_TICKS, t_arg); 241 242 /* set the bell char */ 243 if (o_e != -1 && set_bell(boot0, o_e, 0) != -1) 244 up = 1; 245 246 if (vol_id[4]) { 247 if (b0_ver != 2) 248 errx(1, "incompatible boot block, cannot set volume ID"); 249 boot0[OFF_SERIAL] = vol_id[0]; 250 boot0[OFF_SERIAL+1] = vol_id[1]; 251 boot0[OFF_SERIAL+2] = vol_id[2]; 252 boot0[OFF_SERIAL+3] = vol_id[3]; 253 up = 1; /* force update */ 254 } 255 /* write the MBR back to disk */ 256 if (up) 257 write_mbr(disk, 0, boot0, boot0_size, vol_id[4] || b0_ver == 1); 258 259 /* display the MBR */ 260 if (v_flag) 261 display_mbr(boot0); 262 263 /* clean up */ 264 if (mbr != boot0) 265 free(boot0); 266 free(mbr); 267 free(disk); 268 269 return 0; 270 } 271 272 /* get or set the 'bell' character to be used in case of errors. 273 * Lookup for a certain code sequence, return -1 if not found. 274 */ 275 static int 276 set_bell(u_int8_t *mbr, int new_bell, int report) 277 { 278 /* lookup sequence: 0x100 means skip, 0x200 means done */ 279 static unsigned seq[] = 280 { 0xb0, 0x100, 0xe8, 0x100, 0x100, 0x30, 0xe4, 0x200 }; 281 int ofs, i, c; 282 for (ofs = 0x60; ofs < 0x180; ofs++) { /* search range */ 283 if (mbr[ofs] != seq[0]) /* search initial pattern */ 284 continue; 285 for (i=0;; i++) { 286 if (seq[i] == 0x200) { /* found */ 287 c = mbr[ofs+1]; 288 if (!report) 289 mbr[ofs+1] = c = new_bell; 290 else 291 printf(" bell=%c (0x%x)", 292 (c >= ' ' && c < 0x7f) ? c : ' ', c); 293 return c; 294 } 295 if (seq[i] != 0x100 && seq[i] != mbr[ofs+i]) 296 break; 297 } 298 } 299 warn("bell not found"); 300 return -1; 301 } 302 /* 303 * Read in the MBR of the disk. If it is boot0, then use the version to 304 * read in all of it if necessary. Use pointers to return a malloc'd 305 * buffer containing the MBR and then return its size. 306 */ 307 static int 308 read_mbr(const char *disk, u_int8_t **mbr, int check_version) 309 { 310 u_int8_t buf[MBRSIZE]; 311 int mbr_size, fd; 312 int ver; 313 ssize_t n; 314 315 if ((fd = open(disk, O_RDONLY)) == -1) 316 err(1, "open %s", disk); 317 if ((n = read(fd, buf, MBRSIZE)) == -1) 318 err(1, "read %s", disk); 319 if (n != MBRSIZE) 320 errx(1, "%s: short read", disk); 321 if (cv2(buf + OFF_MAGIC) != 0xaa55) 322 errx(1, "%s: bad magic", disk); 323 324 if (! (ver = boot0bs(buf))) { 325 if (check_version) 326 errx(1, "%s: unknown or incompatible boot code", disk); 327 } else if (boot0version(buf) == 0x101) { 328 mbr_size = 1024; 329 if ((*mbr = malloc(mbr_size)) == NULL) 330 errx(1, "%s: unable to allocate read buffer", disk); 331 if (lseek(fd, 0, SEEK_SET) == -1 || 332 (n = read(fd, *mbr, mbr_size)) == -1) 333 err(1, "%s", disk); 334 if (n != mbr_size) 335 errx(1, "%s: short read", disk); 336 close(fd); 337 return (mbr_size); 338 } 339 if ((*mbr = malloc(sizeof(buf))) == NULL) 340 errx(1, "%s: unable to allocate MBR buffer", disk); 341 memcpy(*mbr, buf, sizeof(buf)); 342 close(fd); 343 344 return sizeof(buf); 345 } 346 347 static int 348 geom_class_available(const char *name) 349 { 350 struct gclass *class; 351 struct gmesh mesh; 352 int error; 353 354 error = geom_gettree(&mesh); 355 if (error != 0) 356 errc(1, error, "Cannot get GEOM tree"); 357 358 LIST_FOREACH(class, &mesh.lg_class, lg_class) { 359 if (strcmp(class->lg_name, name) == 0) { 360 geom_deletetree(&mesh); 361 return (1); 362 } 363 } 364 365 geom_deletetree(&mesh); 366 return (0); 367 } 368 369 /* 370 * Write out the mbr to the specified file. 371 */ 372 static void 373 write_mbr(const char *fname, int flags, u_int8_t *mbr, int mbr_size, 374 int disable_dsn) 375 { 376 struct gctl_req *grq; 377 const char *errmsg; 378 char *pname; 379 ssize_t n; 380 int fd; 381 382 fd = open(fname, O_WRONLY | flags, 0666); 383 if (fd != -1) { 384 n = write(fd, mbr, mbr_size); 385 close(fd); 386 if (n != mbr_size) 387 errx(1, "%s: short write", fname); 388 return; 389 } 390 391 /* 392 * If we're called to write to a backup file, don't try to 393 * write through GEOM. 394 */ 395 if (flags != 0) 396 err(1, "can't open file %s to write backup", fname); 397 398 /* Try open it read only. */ 399 fd = open(fname, O_RDONLY); 400 if (fd == -1) { 401 warn("error opening %s", fname); 402 return; 403 } 404 405 pname = g_providername(fd); 406 if (pname == NULL) { 407 warn("error getting providername for %s", fname); 408 return; 409 } 410 411 /* First check that GEOM_PART is available */ 412 if (geom_class_available("PART") != 0) { 413 grq = gctl_get_handle(); 414 gctl_ro_param(grq, "class", -1, "PART"); 415 gctl_ro_param(grq, "arg0", -1, pname); 416 gctl_ro_param(grq, "verb", -1, "bootcode"); 417 gctl_ro_param(grq, "bootcode", mbr_size, mbr); 418 gctl_ro_param(grq, "flags", -1, "C"); 419 if (disable_dsn) 420 gctl_ro_param(grq, "skip_dsn", sizeof(int), 421 &disable_dsn); 422 errmsg = gctl_issue(grq); 423 if (errmsg != NULL && errmsg[0] != '\0') 424 errx(1, "GEOM_PART: write bootcode to %s failed: %s", 425 fname, errmsg); 426 gctl_free(grq); 427 } else 428 errx(1, "can't write MBR to %s", fname); 429 free(pname); 430 } 431 432 /* 433 * Outputs an informative dump of the data in the MBR to stdout. 434 */ 435 static void 436 display_mbr(u_int8_t *mbr) 437 { 438 struct dos_partition *part; 439 int i, version; 440 441 part = (struct dos_partition *)(mbr + DOSPARTOFF); 442 printf(fmt0); 443 for (i = 0; i < NDOSPART; i++) 444 if (part[i].dp_typ) 445 printf(fmt1, 1 + i, part[i].dp_flag, 446 part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2), 447 part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ, 448 part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2), 449 part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start, 450 part[i].dp_size); 451 printf("\n"); 452 version = boot0version(mbr); 453 printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u", 454 version >> 8, version & 0xff, mbr[OFF_DRIVE], 455 mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS)); 456 set_bell(mbr, 0, 1); 457 printf("\noptions="); 458 for (i = 0; i < nopt; i++) { 459 if (i) 460 printf(","); 461 if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def) 462 printf("no"); 463 printf("%s", opttbl[i].tok); 464 } 465 printf("\n"); 466 if (b0_ver == 2) 467 printf("volume serial ID %02x%02x-%02x%02x\n", 468 mbr[OFF_SERIAL], mbr[OFF_SERIAL+1], 469 mbr[OFF_SERIAL+2], mbr[OFF_SERIAL+3]); 470 printf("default_selection=F%d (", mbr[OFF_OPT] + 1); 471 if (mbr[OFF_OPT] < 4) 472 printf("Slice %d", mbr[OFF_OPT] + 1); 473 else if (mbr[OFF_OPT] == 4) 474 printf("Drive 1"); 475 else 476 printf("PXE"); 477 printf(")\n"); 478 } 479 480 /* 481 * Return the boot0 version with the minor revision in the low byte, and 482 * the major revision in the next higher byte. 483 */ 484 static int 485 boot0version(const u_int8_t *bs) 486 { 487 /* Check for old version, and return 0x100 if found. */ 488 int v = boot0bs(bs); 489 if (v != 0) 490 return v << 8; 491 492 /* We have a newer boot0, so extract the version number and return it. */ 493 return *(const int *)(bs + OFF_VERSION) & 0xffff; 494 } 495 496 /* descriptor of a pattern to match. 497 * Start from the first entry trying to match the chunk of bytes, 498 * if you hit an entry with len=0 terminate the search and report 499 * off as the version. Otherwise skip to the next block after len=0 500 * An entry with len=0, off=0 is the end marker. 501 */ 502 struct byte_pattern { 503 unsigned off; 504 unsigned len; 505 u_int8_t *key; 506 }; 507 508 /* 509 * Decide if we have valid boot0 boot code by looking for 510 * characteristic byte sequences at fixed offsets. 511 */ 512 static int 513 boot0bs(const u_int8_t *bs) 514 { 515 /* the initial code sequence */ 516 static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8, 517 0x8e, 0xd0, 0xbc, 0x00, 0x7c }; 518 /* the drive id */ 519 static u_int8_t id1[] = {'D', 'r', 'i', 'v', 'e', ' '}; 520 static struct byte_pattern patterns[] = { 521 {0x0, sizeof(id0), id0}, 522 {0x1b2, sizeof(id1), id1}, 523 {1, 0, NULL}, 524 {0x0, sizeof(id0), id0}, /* version with NT support */ 525 {0x1ae, sizeof(id1), id1}, 526 {2, 0, NULL}, 527 {0, 0, NULL}, 528 }; 529 struct byte_pattern *p = patterns; 530 531 for (; p->off || p->len; p++) { 532 if (p->len == 0) 533 break; 534 if (!memcmp(bs + p->off, p->key, p->len)) /* match */ 535 continue; 536 while (p->len) /* skip to next block */ 537 p++; 538 } 539 b0_ver = p->off; /* XXX ugly side effect */ 540 return p->off; 541 } 542 543 /* 544 * Adjust "and" and "or" masks for a -o option argument. 545 */ 546 static void 547 stropt(const char *arg, int *xa, int *xo) 548 { 549 const char *q; 550 char *s, *s1; 551 int inv, i, x; 552 553 if (!(s = strdup(arg))) 554 err(1, NULL); 555 for (s1 = s; (q = strtok(s1, ",")); s1 = NULL) { 556 if ((inv = !strncmp(q, "no", 2))) 557 q += 2; 558 for (i = 0; i < nopt; i++) 559 if (!strcmp(q, opttbl[i].tok)) 560 break; 561 if (i == nopt) 562 errx(1, "%s: Unknown -o option", q); 563 if (opttbl[i].def) 564 inv ^= 1; 565 x = 1 << (7 - i); 566 if (inv) 567 *xa &= ~x; 568 else 569 *xo |= x; 570 } 571 free(s); 572 } 573 574 /* 575 * Convert and check an option argument. 576 */ 577 static int 578 argtoi(const char *arg, int lo, int hi, int opt) 579 { 580 char *s; 581 long x; 582 583 errno = 0; 584 x = strtol(arg, &s, 0); 585 if (errno || !*arg || *s || x < lo || x > hi) 586 errx(1, "%s: Bad argument to -%c option", arg, opt); 587 return x; 588 } 589 590 /* 591 * Display usage information. 592 */ 593 static void 594 usage(void) 595 { 596 fprintf(stderr, "%s\n%s\n", 597 "usage: boot0cfg [-Bv] [-b boot0] [-d drive] [-f file] [-m mask]", 598 " [-o options] [-s slice] [-t ticks] disk"); 599 exit(1); 600 } 601