1 /* 2 * Copyright (c) 1999 Robert Nordier 3 * 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 18 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 19 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 20 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 21 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 23 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 24 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD: src/usr.sbin/boot0cfg/boot0cfg.c,v 1.7.2.4 2002/03/16 01:06:51 mikeh Exp $ 27 * $DragonFly: src/usr.sbin/boot0cfg/boot0cfg.c,v 1.5 2007/05/20 23:21:37 dillon Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/diskmbr.h> 32 #include <sys/stat.h> 33 34 #include <err.h> 35 #include <errno.h> 36 #include <fcntl.h> 37 #include <paths.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #define MBRSIZE 512 /* master boot record size */ 44 45 #define OFF_VERSION 0x1b0 /* offset: version number */ 46 #define OFF_OPT 0x1b9 /* offset: default boot option */ 47 #define OFF_DRIVE 0x1ba /* offset: setdrv drive */ 48 #define OFF_FLAGS 0x1bb /* offset: option flags */ 49 #define OFF_TICKS 0x1bc /* offset: clock ticks */ 50 #define OFF_PTBL 0x1be /* offset: partition table */ 51 #define OFF_MAGIC 0x1fe /* offset: magic number */ 52 53 #define cv2(p) ((p)[0] | (p)[1] << 010) 54 55 #define mk2(p, x) \ 56 (p)[0] = (u_int8_t)(x), \ 57 (p)[1] = (u_int8_t)((x) >> 010) 58 59 static const struct { 60 const char *tok; 61 int def; 62 } opttbl[] = { 63 {"packet", 0}, 64 {"update", 1}, 65 {"setdrv", 0} 66 }; 67 static const int nopt = sizeof(opttbl) / sizeof(opttbl[0]); 68 69 static const char fmt0[] = "# flag start chs type" 70 " end chs offset size\n"; 71 72 static const char fmt1[] = "%d 0x%02x %4u:%3u:%2u 0x%02x" 73 " %4u:%3u:%2u %10u %10u\n"; 74 75 static int read_mbr(const char *, u_int8_t **, int); 76 static void write_mbr(const char *, int, u_int8_t *, int); 77 static void display_mbr(u_int8_t *); 78 static int boot0version(const u_int8_t *); 79 static int boot0bs(const u_int8_t *); 80 static void stropt(const char *, int *, int *); 81 static char *mkrdev(const char *); 82 static int argtoi(const char *, int, int, int); 83 static void usage(void); 84 85 /* 86 * Boot manager installation/configuration utility. 87 */ 88 int 89 main(int argc, char *argv[]) 90 { 91 u_int8_t *mbr, *boot0; 92 int boot0_size, mbr_size; 93 const char *bpath, *fpath; 94 char *disk; 95 int B_flag, v_flag, o_flag; 96 int d_arg, m_arg, s_arg, t_arg; 97 int o_and, o_or; 98 int up, c; 99 100 bpath = "/boot/boot0"; 101 fpath = NULL; 102 B_flag = v_flag = o_flag = 0; 103 d_arg = m_arg = s_arg = t_arg = -1; 104 o_and = 0xff; 105 o_or = 0; 106 while ((c = getopt(argc, argv, "Bvb:d:f:m:o:s:t:")) != -1) 107 switch (c) { 108 case 'B': 109 B_flag = 1; 110 break; 111 case 'v': 112 v_flag = 1; 113 break; 114 case 'b': 115 bpath = optarg; 116 break; 117 case 'd': 118 d_arg = argtoi(optarg, 0, 0xff, 'd'); 119 break; 120 case 'f': 121 fpath = optarg; 122 break; 123 case 'm': 124 m_arg = argtoi(optarg, 0, 0xf, 'm'); 125 break; 126 case 'o': 127 stropt(optarg, &o_and, &o_or); 128 o_flag = 1; 129 break; 130 case 's': 131 s_arg = argtoi(optarg, 1, 5, 's'); 132 break; 133 case 't': 134 t_arg = argtoi(optarg, 1, 0xffff, 't'); 135 break; 136 default: 137 usage(); 138 } 139 argc -= optind; 140 argv += optind; 141 if (argc != 1) 142 usage(); 143 disk = mkrdev(*argv); 144 up = B_flag || d_arg != -1 || m_arg != -1 || o_flag || s_arg != -1 145 || t_arg != -1; 146 147 /* open the disk and read in the existing mbr */ 148 mbr_size = read_mbr(disk, &mbr, !B_flag); 149 150 /* save the existing MBR if we are asked to do so */ 151 if (fpath) 152 write_mbr(fpath, O_CREAT | O_TRUNC, mbr, mbr_size); 153 154 /* 155 * If we are installing the boot loader, read it from disk and copy the 156 * slice table over from the existing MBR. If not, then point boot0 157 * back at the MBR we just read in. After this, boot0 is the data to 158 * write back to disk if we are going to do a write. 159 */ 160 if (B_flag) { 161 boot0_size = read_mbr(bpath, &boot0, 1); 162 memcpy(boot0 + OFF_PTBL, mbr + OFF_PTBL, 163 sizeof(struct dos_partition) * NDOSPART); 164 } else { 165 boot0 = mbr; 166 boot0_size = mbr_size; 167 } 168 169 /* set the drive */ 170 if (d_arg != -1) 171 boot0[OFF_DRIVE] = d_arg; 172 173 /* set various flags */ 174 if (m_arg != -1) { 175 boot0[OFF_FLAGS] &= 0xf0; 176 boot0[OFF_FLAGS] |= m_arg; 177 } 178 if (o_flag) { 179 boot0[OFF_FLAGS] &= o_and; 180 boot0[OFF_FLAGS] |= o_or; 181 } 182 183 /* set the default boot selection */ 184 if (s_arg != -1) 185 boot0[OFF_OPT] = s_arg - 1; 186 187 /* set the timeout */ 188 if (t_arg != -1) 189 mk2(boot0 + OFF_TICKS, t_arg); 190 191 /* write the MBR back to disk */ 192 if (up) 193 write_mbr(disk, 0, boot0, boot0_size); 194 195 /* display the MBR */ 196 if (v_flag) 197 display_mbr(boot0); 198 199 /* clean up */ 200 if (mbr != boot0) 201 free(boot0); 202 free(mbr); 203 free(disk); 204 205 return 0; 206 } 207 208 /* 209 * Read in the MBR of the disk. If it is boot0, then use the version to 210 * read in all of it if necessary. Use pointers to return a malloc'd 211 * buffer containing the MBR and then return its size. 212 */ 213 static int 214 read_mbr(const char *disk, u_int8_t **mbr, int check_version) 215 { 216 u_int8_t buf[MBRSIZE]; 217 int mbr_size, fd; 218 ssize_t n; 219 220 if ((fd = open(disk, O_RDONLY)) == -1) 221 err(1, "%s", disk); 222 if ((n = read(fd, buf, MBRSIZE)) == -1) 223 err(1, "%s", disk); 224 if (n != MBRSIZE) 225 errx(1, "%s: short read", disk); 226 if (cv2(buf + OFF_MAGIC) != 0xaa55) 227 errx(1, "%s: bad magic", disk); 228 229 if (!boot0bs(buf)) { 230 if (check_version) 231 errx(1, "%s: unknown or incompatible boot code", disk); 232 } else if (boot0version(buf) == 0x101) { 233 mbr_size = 1024; 234 if ((*mbr = malloc(mbr_size)) == NULL) 235 errx(1, "%s: unable to allocate read buffer", disk); 236 if (lseek(fd, 0, SEEK_SET) == -1 || 237 (n = read(fd, *mbr, mbr_size)) == -1) 238 err(1, "%s", disk); 239 if (n != mbr_size) 240 errx(1, "%s: short read", disk); 241 return (mbr_size); 242 } 243 *mbr = malloc(sizeof(buf)); 244 memcpy(*mbr, buf, sizeof(buf)); 245 246 return sizeof(buf); 247 } 248 249 /* 250 * Write out the mbr to the specified file. 251 */ 252 static void 253 write_mbr(const char *fname, int flags, u_int8_t *mbr, int mbr_size) 254 { 255 int fd; 256 ssize_t n; 257 258 if ((fd = open(fname, O_WRONLY | flags, 0666)) == -1 || 259 (n = write(fd, mbr, mbr_size)) == -1 || close(fd)) 260 err(1, "%s", fname); 261 if (n != mbr_size) 262 errx(1, "%s: short write", fname); 263 } 264 265 /* 266 * Outputs an informative dump of the data in the MBR to stdout. 267 */ 268 static void 269 display_mbr(u_int8_t *mbr) 270 { 271 struct dos_partition *part; 272 int i, version; 273 274 part = (struct dos_partition *)(mbr + DOSPARTOFF); 275 printf(fmt0); 276 for (i = 0; i < NDOSPART; i++) 277 if (part[i].dp_typ) 278 printf(fmt1, 1 + i, part[i].dp_flag, 279 part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2), 280 part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ, 281 part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2), 282 part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start, 283 part[i].dp_size); 284 printf("\n"); 285 version = boot0version(mbr); 286 printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u\noptions=", 287 version >> 8, version & 0xff, mbr[OFF_DRIVE], 288 mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS)); 289 for (i = 0; i < nopt; i++) { 290 if (i) 291 printf(","); 292 if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def) 293 printf("no"); 294 printf("%s", opttbl[i].tok); 295 } 296 printf("\n"); 297 printf("default_selection=F%d (", mbr[OFF_OPT] + 1); 298 if (mbr[OFF_OPT] < 4) 299 printf("Slice %d", mbr[OFF_OPT] + 1); 300 else 301 printf("Drive 1"); 302 printf(")\n"); 303 } 304 305 /* 306 * Return the boot0 version with the minor revision in the low byte, and 307 * the major revision in the next higher byte. 308 */ 309 static int 310 boot0version(const u_int8_t *bs) 311 { 312 static u_int8_t idold[] = {0xfe, 0x45, 0xf2, 0xe9, 0x00, 0x8a}; 313 314 /* Check for old version, and return 0x100 if found. */ 315 if (memcmp(bs + 0x1c, idold, sizeof(idold)) == 0) 316 return 0x100; 317 318 /* We have a newer boot0, so extract the version number and return it. */ 319 return *(const int *)(bs + OFF_VERSION) & 0xffff; 320 } 321 322 /* 323 * Decide if we have valid boot0 boot code by looking for 324 * characteristic byte sequences at fixed offsets. 325 */ 326 static int 327 boot0bs(const u_int8_t *bs) 328 { 329 static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8, 330 0x8e, 0xd0, 0xbc, 0x00, 0x7c }; 331 static u_int8_t id1[] = {0xfc, 0xb8, 0x00, 0x09, 0x8e, 0xc0, 0x8e, 332 0xd0, 0xbc, 0x00, 0x10 ,0x31 }; 333 static u_int8_t id2[] = {'D', 'r', 'i', 'v', 'e', ' '}; 334 static struct { 335 unsigned off; 336 unsigned len; 337 u_int8_t *key; 338 } ident[] = { 339 {0x0, sizeof(id0), id0}, 340 {0x0, sizeof(id1), id1}, 341 {0x1b2, sizeof(id2), id2} 342 }; 343 unsigned int i; 344 int count = 0; 345 346 for (i = 0; i < sizeof(ident) / sizeof(ident[0]); i++) { 347 if (memcmp(bs + ident[i].off, ident[i].key, ident[i].len) == 0) 348 ++count; 349 } 350 if (count >= 2) 351 return 1; 352 return 0; 353 }; 354 355 /* 356 * Adjust "and" and "or" masks for a -o option argument. 357 */ 358 static void 359 stropt(const char *arg, int *xa, int *xo) 360 { 361 const char *q; 362 char *s, *s1; 363 int inv, i, x; 364 365 if (!(s = strdup(arg))) 366 err(1, NULL); 367 for (s1 = s; (q = strtok(s1, ",")); s1 = NULL) { 368 if ((inv = !strncmp(q, "no", 2))) 369 q += 2; 370 for (i = 0; i < nopt; i++) 371 if (!strcmp(q, opttbl[i].tok)) 372 break; 373 if (i == nopt) 374 errx(1, "%s: Unknown -o option", q); 375 if (opttbl[i].def) 376 inv ^= 1; 377 x = 1 << (7 - i); 378 if (inv) 379 *xa &= ~x; 380 else 381 *xo |= x; 382 } 383 free(s); 384 } 385 386 /* 387 * Produce a device path for a "canonical" name, where appropriate. 388 */ 389 static char * 390 mkrdev(const char *fname) 391 { 392 char buf[MAXPATHLEN]; 393 char *s; 394 395 if (!strchr(fname, '/')) { 396 snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname); 397 s = strdup(buf); 398 } else 399 s = strdup(fname); 400 401 if (s == NULL) 402 errx(1, "No more memory"); 403 return s; 404 } 405 406 /* 407 * Convert and check an option argument. 408 */ 409 static int 410 argtoi(const char *arg, int lo, int hi, int opt) 411 { 412 char *s; 413 long x; 414 415 errno = 0; 416 x = strtol(arg, &s, 0); 417 if (errno || !*arg || *s || x < lo || x > hi) 418 errx(1, "%s: Bad argument to -%c option", arg, opt); 419 return x; 420 } 421 422 /* 423 * Display usage information. 424 */ 425 static void 426 usage(void) 427 { 428 fprintf(stderr, "%s\n%s\n", 429 "usage: boot0cfg [-Bv] [-b boot0] [-d drive] [-f file] [-m mask]", 430 " [-o options] [-s slice] [-t ticks] disk"); 431 exit(1); 432 } 433