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