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