1 /*- 2 * Copyright (c) 1994 Bruce D. Evans. 3 * All rights reserved. 4 * 5 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 37 * from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $ 38 * $FreeBSD: src/sys/kern/subr_diskmbr.c,v 1.45 2000/01/28 10:22:07 bde Exp $ 39 * $DragonFly: src/sys/kern/subr_diskmbr.c,v 1.24 2007/05/19 09:46:18 dillon Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/buf.h> 45 #include <sys/conf.h> 46 #include <sys/diskslice.h> 47 #define DOSPTYP_EXTENDED 5 48 #define DOSPTYP_EXTENDEDX 15 49 #define DOSPTYP_ONTRACK 84 50 #include <sys/diskslice.h> 51 #include <sys/diskmbr.h> 52 #include <sys/disk.h> 53 #include <sys/malloc.h> 54 #include <sys/syslog.h> 55 #include <sys/device.h> 56 57 #define TRACE(str) do { if (dsi_debug) kprintf str; } while (0) 58 59 static volatile u_char dsi_debug; 60 61 /* 62 * This is what we have embedded in every boot1 for supporting the bogus 63 * "Dangerously Dedicated" mode. However, the old table is broken because 64 * it has an illegal geometry in it - it specifies 256 heads (heads = end 65 * head + 1) which causes nasty stuff when that wraps to zero in bios code. 66 * eg: divide by zero etc. This caused the dead-thinkpad problem, numerous 67 * SCSI bios crashes, EFI to crash, etc. 68 * 69 * We still have to recognize the old table though, even though we stopped 70 * inflicting it upon the world. 71 */ 72 static struct dos_partition historical_bogus_partition_table[NDOSPART] = { 73 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 74 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 75 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 76 { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, }, 77 }; 78 static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = { 79 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 80 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 81 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 82 { 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, }, 83 }; 84 85 static int check_part (char *sname, struct dos_partition *dp, 86 u_int64_t offset, int nsectors, int ntracks, 87 u_int64_t mbr_offset); 88 static void mbr_extended (cdev_t dev, struct disk_info *info, 89 struct diskslices *ssp, u_int64_t ext_offset, 90 u_int64_t ext_size, u_int64_t base_ext_offset, 91 int nsectors, int ntracks, u_int64_t mbr_offset, 92 int level); 93 static int mbr_setslice (char *sname, struct disk_info *info, 94 struct diskslice *sp, struct dos_partition *dp, 95 u_int64_t br_offset); 96 97 98 int 99 mbrinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp) 100 { 101 struct buf *bp; 102 u_char *cp; 103 int dospart; 104 struct dos_partition *dp; 105 struct dos_partition *dp0; 106 struct dos_partition dpcopy[NDOSPART]; 107 int error; 108 int max_ncyls; 109 int max_nsectors; 110 int max_ntracks; 111 u_int64_t mbr_offset; 112 char partname[2]; 113 u_long secpercyl; 114 char *sname; 115 struct diskslice *sp; 116 struct diskslices *ssp; 117 cdev_t wdev; 118 119 mbr_offset = DOSBBSECTOR; 120 reread_mbr: 121 if (info->d_media_blksize & DEV_BMASK) 122 return (EIO); 123 /* Read master boot record. */ 124 wdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), WHOLE_SLICE_PART); 125 bp = geteblk((int)info->d_media_blksize); 126 bp->b_bio1.bio_offset = (off_t)mbr_offset * info->d_media_blksize; 127 bp->b_bcount = info->d_media_blksize; 128 bp->b_cmd = BUF_CMD_READ; 129 dev_dstrategy(wdev, &bp->b_bio1); 130 if (biowait(bp) != 0) { 131 diskerr(&bp->b_bio1, wdev, 132 "reading primary partition table: error", 133 LOG_PRINTF, 0); 134 kprintf("\n"); 135 error = EIO; 136 goto done; 137 } 138 139 /* Weakly verify it. */ 140 cp = bp->b_data; 141 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, WHOLE_SLICE_PART, partname); 142 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 143 if (bootverbose) 144 kprintf("%s: invalid primary partition table: no magic\n", 145 sname); 146 error = EINVAL; 147 goto done; 148 } 149 150 /* Make a copy of the partition table to avoid alignment problems. */ 151 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 152 153 dp0 = &dpcopy[0]; 154 155 /* Check for "Ontrack Diskmanager". */ 156 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 157 if (dp->dp_typ == DOSPTYP_ONTRACK) { 158 if (bootverbose) 159 kprintf( 160 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname); 161 bp->b_flags |= B_INVAL | B_AGE; 162 brelse(bp); 163 mbr_offset = 63; 164 goto reread_mbr; 165 } 166 } 167 168 if (bcmp(dp0, historical_bogus_partition_table, 169 sizeof historical_bogus_partition_table) == 0 || 170 bcmp(dp0, historical_bogus_partition_table_fixed, 171 sizeof historical_bogus_partition_table_fixed) == 0) { 172 #if 0 173 TRACE(("%s: invalid primary partition table: historical\n", 174 sname)); 175 #endif /* 0 */ 176 if (bootverbose) 177 kprintf( 178 "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n", 179 sname); 180 error = EINVAL; 181 goto done; 182 } 183 184 /* Guess the geometry. */ 185 /* 186 * TODO: 187 * Perhaps skip entries with 0 size. 188 * Perhaps only look at entries of type DOSPTYP_386BSD. 189 */ 190 max_ncyls = 0; 191 max_nsectors = 0; 192 max_ntracks = 0; 193 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 194 int ncyls; 195 int nsectors; 196 int ntracks; 197 198 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1; 199 if (max_ncyls < ncyls) 200 max_ncyls = ncyls; 201 nsectors = DPSECT(dp->dp_esect); 202 if (max_nsectors < nsectors) 203 max_nsectors = nsectors; 204 ntracks = dp->dp_ehd + 1; 205 if (max_ntracks < ntracks) 206 max_ntracks = ntracks; 207 } 208 209 /* 210 * Check that we have guessed the geometry right by checking the 211 * partition entries. 212 */ 213 /* 214 * TODO: 215 * As above. 216 * Check for overlaps. 217 * Check against d_secperunit if the latter is reliable. 218 */ 219 error = 0; 220 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 221 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 222 && dp->dp_start == 0 && dp->dp_size == 0) 223 continue; 224 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 225 WHOLE_SLICE_PART, partname); 226 227 /* 228 * Temporarily ignore errors from this check. We could 229 * simplify things by accepting the table eariler if we 230 * always ignore errors here. Perhaps we should always 231 * accept the table if the magic is right but not let 232 * bad entries affect the geometry. 233 */ 234 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks, 235 mbr_offset); 236 } 237 if (error != 0) 238 goto done; 239 240 /* 241 * Accept the DOS partition table. 242 * 243 * Adjust the disk information structure with updated CHS 244 * conversion parameters, but only use values extracted from 245 * the primary partition table. 246 * 247 * NOTE! Regardless of our having to deal with this old cruft, 248 * we do not screw around with the info->d_media* parameters. 249 */ 250 secpercyl = (u_long)max_nsectors * max_ntracks; 251 if (secpercyl != 0 && mbr_offset == DOSBBSECTOR) { 252 info->d_secpertrack = max_nsectors; 253 info->d_nheads = max_ntracks; 254 info->d_secpercyl = secpercyl; 255 info->d_ncylinders = info->d_media_blocks / secpercyl; 256 } 257 258 /* 259 * We are passed a pointer to a suitably initialized minimal 260 * slices "struct" with no dangling pointers in it. Replace it 261 * by a maximal one. This usually oversizes the "struct", but 262 * enlarging it while searching for logical drives would be 263 * inconvenient. 264 */ 265 kfree(*sspp, M_DEVBUF); 266 ssp = dsmakeslicestruct(MAX_SLICES, info); 267 *sspp = ssp; 268 269 /* Initialize normal slices. */ 270 sp = &ssp->dss_slices[BASE_SLICE]; 271 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) { 272 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 273 WHOLE_SLICE_PART, partname); 274 (void)mbr_setslice(sname, info, sp, dp, mbr_offset); 275 } 276 ssp->dss_nslices = BASE_SLICE + NDOSPART; 277 278 /* Handle extended partitions. */ 279 sp -= NDOSPART; 280 for (dospart = 0; dospart < NDOSPART; dospart++, sp++) { 281 if (sp->ds_type == DOSPTYP_EXTENDED || 282 sp->ds_type == DOSPTYP_EXTENDEDX) { 283 mbr_extended(wdev, info, ssp, 284 sp->ds_offset, sp->ds_size, sp->ds_offset, 285 max_nsectors, max_ntracks, mbr_offset, 1); 286 } 287 } 288 289 /* 290 * mbr_extended() abuses ssp->dss_nslices for the number of slices 291 * that would be found if there were no limit on the number of slices 292 * in *ssp. Cut it back now. 293 */ 294 if (ssp->dss_nslices > MAX_SLICES) 295 ssp->dss_nslices = MAX_SLICES; 296 297 done: 298 bp->b_flags |= B_INVAL | B_AGE; 299 brelse(bp); 300 if (error == EINVAL) 301 error = 0; 302 return (error); 303 } 304 305 static int 306 check_part(char *sname, struct dos_partition *dp, u_int64_t offset, 307 int nsectors, int ntracks, u_int64_t mbr_offset) 308 { 309 int chs_ecyl; 310 int chs_esect; 311 int chs_scyl; 312 int chs_ssect; 313 int error; 314 u_long secpercyl; 315 u_int64_t esector; 316 u_int64_t esector1; 317 u_int64_t ssector; 318 u_int64_t ssector1; 319 320 secpercyl = (u_long)nsectors * ntracks; 321 chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect); 322 chs_ssect = DPSECT(dp->dp_ssect); 323 ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl 324 + mbr_offset; 325 ssector1 = offset + dp->dp_start; 326 327 /* 328 * If ssector1 is on a cylinder >= 1024, then ssector can't be right. 329 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct 330 * apart from the cylinder being reduced modulo 1024. Always allow 331 * 1023/255/63, because this is the official way to represent 332 * pure-LBA for the starting position. 333 */ 334 if ((ssector < ssector1 335 && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1 336 && chs_scyl == 1023) 337 || (secpercyl != 0 338 && (ssector1 - ssector) % (1024 * secpercyl) == 0))) 339 || (dp->dp_scyl == 255 && dp->dp_shd == 255 340 && dp->dp_ssect == 255)) { 341 TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n", 342 sname, chs_scyl, dp->dp_shd, chs_ssect, ssector1)); 343 ssector = ssector1; 344 } 345 346 chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect); 347 chs_esect = DPSECT(dp->dp_esect); 348 esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl 349 + mbr_offset; 350 esector1 = ssector1 + dp->dp_size - 1; 351 352 /* 353 * Allow certain bogus C/H/S values for esector, as above. However, 354 * heads == 255 isn't really legal and causes some BIOS crashes. The 355 * correct value to indicate a pure-LBA end is 1023/heads-1/sectors - 356 * usually 1023/254/63. "heads" is base 0, "sectors" is base 1. 357 */ 358 if ((esector < esector1 359 && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1 360 && chs_ecyl == 1023) 361 || (secpercyl != 0 362 && (esector1 - esector) % (1024 * secpercyl) == 0))) 363 || (dp->dp_ecyl == 255 && dp->dp_ehd == 255 364 && dp->dp_esect == 255)) { 365 TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n", 366 sname, chs_ecyl, dp->dp_ehd, chs_esect, esector1)); 367 esector = esector1; 368 } 369 370 error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL; 371 if (bootverbose) 372 kprintf("%s: type 0x%x, start %llu, end = %llu, size %lu %s\n", 373 sname, dp->dp_typ, ssector1, esector1, 374 (u_long)dp->dp_size, error ? "" : ": OK"); 375 if (ssector != ssector1 && bootverbose) 376 kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n", 377 sname, chs_scyl, dp->dp_shd, chs_ssect, 378 ssector, ssector1); 379 if (esector != esector1 && bootverbose) 380 kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n", 381 sname, chs_ecyl, dp->dp_ehd, chs_esect, 382 esector, esector1); 383 return (error); 384 } 385 386 static 387 void 388 mbr_extended(cdev_t dev, struct disk_info *info, struct diskslices *ssp, 389 u_int64_t ext_offset, u_int64_t ext_size, u_int64_t base_ext_offset, 390 int nsectors, int ntracks, u_int64_t mbr_offset, int level) 391 { 392 struct buf *bp; 393 u_char *cp; 394 int dospart; 395 struct dos_partition *dp; 396 struct dos_partition dpcopy[NDOSPART]; 397 u_int64_t ext_offsets[NDOSPART]; 398 u_int64_t ext_sizes[NDOSPART]; 399 char partname[2]; 400 int slice; 401 char *sname; 402 struct diskslice *sp; 403 404 if (level >= 16) { 405 kprintf( 406 "%s: excessive recursion in search for slices; aborting search\n", 407 devtoname(dev)); 408 return; 409 } 410 411 /* Read extended boot record. */ 412 bp = geteblk((int)info->d_media_blksize); 413 bp->b_bio1.bio_offset = (off_t)ext_offset * info->d_media_blksize; 414 bp->b_bcount = info->d_media_blksize; 415 bp->b_cmd = BUF_CMD_READ; 416 dev_dstrategy(dev, &bp->b_bio1); 417 if (biowait(bp) != 0) { 418 diskerr(&bp->b_bio1, dev, 419 "reading extended partition table: error", 420 LOG_PRINTF, 0); 421 kprintf("\n"); 422 goto done; 423 } 424 425 /* Weakly verify it. */ 426 cp = bp->b_data; 427 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 428 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, WHOLE_SLICE_PART, 429 partname); 430 if (bootverbose) 431 kprintf("%s: invalid extended partition table: no magic\n", 432 sname); 433 goto done; 434 } 435 436 /* Make a copy of the partition table to avoid alignment problems. */ 437 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 438 439 slice = ssp->dss_nslices; 440 for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART; 441 dospart++, dp++) { 442 ext_sizes[dospart] = 0; 443 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 444 && dp->dp_start == 0 && dp->dp_size == 0) 445 continue; 446 if (dp->dp_typ == DOSPTYP_EXTENDED || 447 dp->dp_typ == DOSPTYP_EXTENDEDX) { 448 static char buf[32]; 449 450 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, 451 WHOLE_SLICE_PART, partname); 452 ksnprintf(buf, sizeof(buf), "%s", sname); 453 if (strlen(buf) < sizeof buf - 11) 454 strcat(buf, "<extended>"); 455 check_part(buf, dp, base_ext_offset, nsectors, 456 ntracks, mbr_offset); 457 ext_offsets[dospart] = base_ext_offset + dp->dp_start; 458 ext_sizes[dospart] = dp->dp_size; 459 } else { 460 sname = dsname(dev, dkunit(dev), slice, WHOLE_SLICE_PART, 461 partname); 462 check_part(sname, dp, ext_offset, nsectors, ntracks, 463 mbr_offset); 464 if (slice >= MAX_SLICES) { 465 kprintf("%s: too many slices\n", sname); 466 slice++; 467 continue; 468 } 469 sp = &ssp->dss_slices[slice]; 470 if (mbr_setslice(sname, info, sp, dp, ext_offset) != 0) 471 continue; 472 slice++; 473 } 474 } 475 ssp->dss_nslices = slice; 476 477 /* If we found any more slices, recursively find all the subslices. */ 478 for (dospart = 0; dospart < NDOSPART; dospart++) { 479 if (ext_sizes[dospart] != 0) { 480 mbr_extended(dev, info, ssp, ext_offsets[dospart], 481 ext_sizes[dospart], base_ext_offset, 482 nsectors, ntracks, mbr_offset, ++level); 483 } 484 } 485 486 done: 487 bp->b_flags |= B_INVAL | B_AGE; 488 brelse(bp); 489 } 490 491 static int 492 mbr_setslice(char *sname, struct disk_info *info, struct diskslice *sp, 493 struct dos_partition *dp, u_int64_t br_offset) 494 { 495 u_int64_t offset; 496 u_int64_t size; 497 498 offset = br_offset + dp->dp_start; 499 if (offset > info->d_media_blocks || offset < br_offset) { 500 kprintf( 501 "%s: slice starts beyond end of the disk: rejecting it\n", 502 sname); 503 return (1); 504 } 505 size = info->d_media_blocks - offset; 506 if (size >= dp->dp_size) 507 size = dp->dp_size; 508 else 509 kprintf( 510 "%s: slice extends beyond end of disk: truncating from %lu to %llu sectors\n", 511 sname, (u_long)dp->dp_size, size); 512 sp->ds_offset = offset; 513 sp->ds_size = size; 514 sp->ds_type = dp->dp_typ; 515 516 /* 517 * The first sector in each slice is reserved for a system boot 518 * sector. ds_skip_bsdlabel is always inclusive of ds_skip_platform, 519 * if they are the same then there is no label present (or yet 520 * loaded). 521 */ 522 sp->ds_skip_platform = 1; 523 sp->ds_skip_bsdlabel = 1; 524 return (0); 525 } 526