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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 33 * from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $ 34 * $FreeBSD: src/sys/kern/subr_diskmbr.c,v 1.45 2000/01/28 10:22:07 bde Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/buf.h> 40 #include <sys/conf.h> 41 #include <sys/diskslice.h> 42 #define DOSPTYP_EXTENDED 5 43 #define DOSPTYP_EXTENDEDX 15 44 #define DOSPTYP_ONTRACK 84 45 #include <sys/diskmbr.h> 46 #include <sys/disk.h> 47 #include <sys/malloc.h> 48 #include <sys/syslog.h> 49 #include <sys/device.h> 50 51 #define TRACE(str) do { if (dsi_debug) kprintf str; } while (0) 52 53 static volatile u_char dsi_debug; 54 55 /* 56 * This is what we have embedded in every boot1 for supporting the bogus 57 * "Dangerously Dedicated" mode. However, the old table is broken because 58 * it has an illegal geometry in it - it specifies 256 heads (heads = end 59 * head + 1) which causes nasty stuff when that wraps to zero in bios code. 60 * eg: divide by zero etc. This caused the dead-thinkpad problem, numerous 61 * SCSI bios crashes, EFI to crash, etc. 62 * 63 * We still have to recognize the old table though, even though we stopped 64 * inflicting it upon the world. 65 */ 66 static struct dos_partition historical_bogus_partition_table[NDOSPART] = { 67 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 68 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 69 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 70 { 0x80, 0, 1, 0, DOSPTYP_DFLYBSD, 255, 255, 255, 0, 50000, }, 71 }; 72 static struct dos_partition historical_bogus_partition_table_fixed[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_DFLYBSD, 254, 255, 255, 0, 50000, }, 77 }; 78 79 static int check_part (char *sname, struct dos_partition *dp, 80 u_int64_t offset, int nsectors, int ntracks, 81 u_int64_t mbr_offset); 82 static void mbr_extended (cdev_t dev, struct disk_info *info, 83 struct diskslices *ssp, u_int64_t ext_offset, 84 u_int64_t ext_size, u_int64_t base_ext_offset, 85 int nsectors, int ntracks, u_int64_t mbr_offset, 86 int level); 87 static int mbr_setslice (char *sname, struct disk_info *info, 88 struct diskslice *sp, struct dos_partition *dp, 89 u_int64_t br_offset); 90 91 92 int 93 mbrinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp) 94 { 95 struct buf *bp; 96 u_char *cp; 97 int dospart; 98 struct dos_partition *dp; 99 struct dos_partition *dp0; 100 struct dos_partition dpcopy[NDOSPART]; 101 int error; 102 int max_ncyls; 103 int max_nsectors; 104 int max_ntracks; 105 u_int64_t mbr_offset; 106 char partname[2]; 107 u_long secpercyl; 108 char *sname = "tempname"; 109 struct diskslice *sp; 110 struct diskslices *ssp; 111 cdev_t wdev; 112 113 mbr_offset = DOSBBSECTOR; 114 reread_mbr: 115 /* 116 * Don't bother if the block size is weird or the 117 * media size is 0 (probably means no media present). 118 */ 119 if (info->d_media_blksize & DEV_BMASK) 120 return (EIO); 121 if (info->d_media_size == 0) 122 return (EIO); 123 124 /* 125 * Read master boot record. 126 */ 127 wdev = dev; 128 bp = getpbuf_mem(NULL); 129 KKASSERT((int)info->d_media_blksize <= bp->b_bufsize); 130 bp->b_bio1.bio_offset = (off_t)mbr_offset * info->d_media_blksize; 131 bp->b_bio1.bio_done = biodone_sync; 132 bp->b_bio1.bio_flags |= BIO_SYNC; 133 bp->b_bcount = info->d_media_blksize; 134 bp->b_cmd = BUF_CMD_READ; 135 bp->b_flags |= B_FAILONDIS; 136 dev_dstrategy(wdev, &bp->b_bio1); 137 if (biowait(&bp->b_bio1, "mbrrd") != 0) { 138 if ((info->d_dsflags & DSO_MBRQUIET) == 0) { 139 diskerr(&bp->b_bio1, wdev, 140 "reading primary partition table: error", 141 LOG_PRINTF, 0); 142 kprintf("\n"); 143 } 144 error = EIO; 145 goto done; 146 } 147 148 /* Weakly verify it. */ 149 cp = bp->b_data; 150 sname = dsname(dev, 0, 0, 0, NULL); 151 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 152 if (bootverbose) 153 kprintf("%s: invalid primary partition table: no magic\n", 154 sname); 155 error = EINVAL; 156 goto done; 157 } 158 159 /* Make a copy of the partition table to avoid alignment problems. */ 160 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 161 162 dp0 = &dpcopy[0]; 163 164 /* 165 * Check for "Ontrack Diskmanager" or GPT. If a GPT is found in 166 * the first dos partition, ignore the rest of the MBR and go 167 * to GPT processing. 168 */ 169 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 170 if (dospart == 0 && dp->dp_typ == DOSPTYP_PMBR) { 171 if (bootverbose) 172 kprintf( 173 "%s: Found GPT in slice #%d\n", sname, dospart + 1); 174 error = gptinit(dev, info, sspp); 175 goto done; 176 } 177 178 if (dp->dp_typ == DOSPTYP_ONTRACK) { 179 if (bootverbose) 180 kprintf( 181 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname); 182 bp->b_flags |= B_INVAL | B_AGE; 183 brelse(bp); 184 mbr_offset = 63; 185 goto reread_mbr; 186 } 187 } 188 189 if (bcmp(dp0, historical_bogus_partition_table, 190 sizeof historical_bogus_partition_table) == 0 || 191 bcmp(dp0, historical_bogus_partition_table_fixed, 192 sizeof historical_bogus_partition_table_fixed) == 0) { 193 #if 0 194 TRACE(("%s: invalid primary partition table: historical\n", 195 sname)); 196 #endif /* 0 */ 197 if (bootverbose) 198 kprintf( 199 "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n", 200 sname); 201 error = EINVAL; 202 goto done; 203 } 204 205 /* Guess the geometry. */ 206 /* 207 * TODO: 208 * Perhaps skip entries with 0 size. 209 * Perhaps only look at entries of type DOSPTYP_386BSD or 210 * DOSPTYP_DFLYBSD 211 */ 212 max_ncyls = 0; 213 max_nsectors = 0; 214 max_ntracks = 0; 215 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 216 int ncyls; 217 int nsectors; 218 int ntracks; 219 220 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1; 221 if (max_ncyls < ncyls) 222 max_ncyls = ncyls; 223 nsectors = DPSECT(dp->dp_esect); 224 if (max_nsectors < nsectors) 225 max_nsectors = nsectors; 226 ntracks = dp->dp_ehd + 1; 227 if (max_ntracks < ntracks) 228 max_ntracks = ntracks; 229 } 230 231 /* 232 * Check that we have guessed the geometry right by checking the 233 * partition entries. 234 */ 235 /* 236 * TODO: 237 * As above. 238 * Check for overlaps. 239 * Check against d_secperunit if the latter is reliable. 240 */ 241 error = 0; 242 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 243 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 244 && dp->dp_start == 0 && dp->dp_size == 0) 245 continue; 246 //sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 247 // WHOLE_SLICE_PART, partname); 248 249 /* 250 * Temporarily ignore errors from this check. We could 251 * simplify things by accepting the table eariler if we 252 * always ignore errors here. Perhaps we should always 253 * accept the table if the magic is right but not let 254 * bad entries affect the geometry. 255 */ 256 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks, 257 mbr_offset); 258 } 259 if (error != 0) 260 goto done; 261 262 /* 263 * Accept the DOS partition table. 264 * 265 * Adjust the disk information structure with updated CHS 266 * conversion parameters, but only use values extracted from 267 * the primary partition table. 268 * 269 * NOTE! Regardless of our having to deal with this old cruft, 270 * we do not screw around with the info->d_media* parameters. 271 */ 272 secpercyl = (u_long)max_nsectors * max_ntracks; 273 if (secpercyl != 0 && mbr_offset == DOSBBSECTOR) { 274 info->d_secpertrack = max_nsectors; 275 info->d_nheads = max_ntracks; 276 info->d_secpercyl = secpercyl; 277 info->d_ncylinders = info->d_media_blocks / secpercyl; 278 } 279 280 /* 281 * We are passed a pointer to a suitably initialized minimal 282 * slices "struct" with no dangling pointers in it. Replace it 283 * by a maximal one. This usually oversizes the "struct", but 284 * enlarging it while searching for logical drives would be 285 * inconvenient. 286 */ 287 kfree(*sspp, M_DEVBUF); 288 ssp = dsmakeslicestruct(MAX_SLICES, info); 289 *sspp = ssp; 290 291 /* Initialize normal slices. */ 292 sp = &ssp->dss_slices[BASE_SLICE]; 293 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) { 294 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 295 WHOLE_SLICE_PART, partname); 296 (void)mbr_setslice(sname, info, sp, dp, mbr_offset); 297 } 298 ssp->dss_nslices = BASE_SLICE + NDOSPART; 299 300 /* Handle extended partitions. */ 301 sp -= NDOSPART; 302 for (dospart = 0; dospart < NDOSPART; dospart++, sp++) { 303 if (sp->ds_type == DOSPTYP_EXTENDED || 304 sp->ds_type == DOSPTYP_EXTENDEDX) { 305 mbr_extended(wdev, info, ssp, 306 sp->ds_offset, sp->ds_size, sp->ds_offset, 307 max_nsectors, max_ntracks, mbr_offset, 1); 308 } 309 } 310 311 /* 312 * mbr_extended() abuses ssp->dss_nslices for the number of slices 313 * that would be found if there were no limit on the number of slices 314 * in *ssp. Cut it back now. 315 */ 316 if (ssp->dss_nslices > MAX_SLICES) 317 ssp->dss_nslices = MAX_SLICES; 318 319 done: 320 bp->b_flags |= B_INVAL | B_AGE; 321 relpbuf(bp, NULL); 322 if (error == EINVAL) 323 error = 0; 324 return (error); 325 } 326 327 static int 328 check_part(char *sname, struct dos_partition *dp, u_int64_t offset, 329 int nsectors, int ntracks, u_int64_t mbr_offset) 330 { 331 int chs_ecyl; 332 int chs_esect; 333 int chs_scyl; 334 int chs_ssect; 335 int error; 336 u_long secpercyl; 337 u_int64_t esector; 338 u_int64_t esector1; 339 u_int64_t ssector; 340 u_int64_t ssector1; 341 342 secpercyl = (u_long)nsectors * ntracks; 343 chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect); 344 chs_ssect = DPSECT(dp->dp_ssect); 345 ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl 346 + mbr_offset; 347 ssector1 = offset + dp->dp_start; 348 349 /* 350 * If ssector1 is on a cylinder >= 1024, then ssector can't be right. 351 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct 352 * apart from the cylinder being reduced modulo 1024. Always allow 353 * 1023/255/63, because this is the official way to represent 354 * pure-LBA for the starting position. 355 */ 356 if ((ssector < ssector1 357 && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1 358 && chs_scyl == 1023) 359 || (secpercyl != 0 360 && (ssector1 - ssector) % (1024 * secpercyl) == 0))) 361 || (dp->dp_scyl == 255 && dp->dp_shd == 255 362 && dp->dp_ssect == 255)) { 363 TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n", 364 sname, chs_scyl, dp->dp_shd, chs_ssect, 365 (long long)ssector1)); 366 ssector = ssector1; 367 } 368 369 chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect); 370 chs_esect = DPSECT(dp->dp_esect); 371 esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl 372 + mbr_offset; 373 esector1 = ssector1 + dp->dp_size - 1; 374 375 /* 376 * Allow certain bogus C/H/S values for esector, as above. However, 377 * heads == 255 isn't really legal and causes some BIOS crashes. The 378 * correct value to indicate a pure-LBA end is 1023/heads-1/sectors - 379 * usually 1023/254/63. "heads" is base 0, "sectors" is base 1. 380 */ 381 if ((esector < esector1 382 && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1 383 && chs_ecyl == 1023) 384 || (secpercyl != 0 385 && (esector1 - esector) % (1024 * secpercyl) == 0))) 386 || (dp->dp_ecyl == 255 && dp->dp_ehd == 255 387 && dp->dp_esect == 255)) { 388 TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n", 389 sname, chs_ecyl, dp->dp_ehd, chs_esect, 390 (long long)esector1)); 391 esector = esector1; 392 } 393 394 error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL; 395 if (bootverbose) 396 kprintf("%s: type 0x%x, start %llu, end = %llu, size %u %s\n", 397 sname, dp->dp_typ, 398 (long long)ssector1, (long long)esector1, 399 dp->dp_size, (error ? "" : ": OK")); 400 if (ssector != ssector1 && bootverbose) 401 kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n", 402 sname, chs_scyl, dp->dp_shd, chs_ssect, 403 (long long)ssector, (long long)ssector1); 404 if (esector != esector1 && bootverbose) 405 kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n", 406 sname, chs_ecyl, dp->dp_ehd, chs_esect, 407 (long long)esector, (long long)esector1); 408 return (error); 409 } 410 411 static 412 void 413 mbr_extended(cdev_t dev, struct disk_info *info, struct diskslices *ssp, 414 u_int64_t ext_offset, u_int64_t ext_size, u_int64_t base_ext_offset, 415 int nsectors, int ntracks, u_int64_t mbr_offset, int level) 416 { 417 struct buf *bp; 418 u_char *cp; 419 int dospart; 420 struct dos_partition *dp; 421 struct dos_partition dpcopy[NDOSPART]; 422 u_int64_t ext_offsets[NDOSPART]; 423 u_int64_t ext_sizes[NDOSPART]; 424 char partname[2]; 425 int slice; 426 char *sname; 427 struct diskslice *sp; 428 429 if (level >= 16) { 430 kprintf( 431 "%s: excessive recursion in search for slices; aborting search\n", 432 devtoname(dev)); 433 return; 434 } 435 436 /* Read extended boot record. */ 437 bp = getpbuf_mem(NULL); 438 KKASSERT((int)info->d_media_blksize <= bp->b_bufsize); 439 bp->b_bio1.bio_offset = (off_t)ext_offset * info->d_media_blksize; 440 bp->b_bio1.bio_done = biodone_sync; 441 bp->b_bio1.bio_flags |= BIO_SYNC; 442 bp->b_bcount = info->d_media_blksize; 443 bp->b_cmd = BUF_CMD_READ; 444 bp->b_flags |= B_FAILONDIS; 445 dev_dstrategy(dev, &bp->b_bio1); 446 if (biowait(&bp->b_bio1, "mbrrd") != 0) { 447 diskerr(&bp->b_bio1, dev, 448 "reading extended partition table: error", 449 LOG_PRINTF, 0); 450 kprintf("\n"); 451 goto done; 452 } 453 454 /* Weakly verify it. */ 455 cp = bp->b_data; 456 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 457 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, WHOLE_SLICE_PART, 458 partname); 459 if (bootverbose) 460 kprintf("%s: invalid extended partition table: no magic\n", 461 sname); 462 goto done; 463 } 464 465 /* Make a copy of the partition table to avoid alignment problems. */ 466 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 467 468 slice = ssp->dss_nslices; 469 for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART; 470 dospart++, dp++) { 471 ext_sizes[dospart] = 0; 472 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 473 && dp->dp_start == 0 && dp->dp_size == 0) 474 continue; 475 if (dp->dp_typ == DOSPTYP_EXTENDED || 476 dp->dp_typ == DOSPTYP_EXTENDEDX) { 477 static char buf[32]; 478 479 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, 480 WHOLE_SLICE_PART, partname); 481 ksnprintf(buf, sizeof(buf), "%s", sname); 482 if (strlen(buf) < sizeof buf - 11) 483 strcat(buf, "<extended>"); 484 check_part(buf, dp, base_ext_offset, nsectors, 485 ntracks, mbr_offset); 486 ext_offsets[dospart] = base_ext_offset + dp->dp_start; 487 ext_sizes[dospart] = dp->dp_size; 488 } else { 489 sname = dsname(dev, dkunit(dev), slice, WHOLE_SLICE_PART, 490 partname); 491 check_part(sname, dp, ext_offset, nsectors, ntracks, 492 mbr_offset); 493 if (slice >= MAX_SLICES) { 494 kprintf("%s: too many slices\n", sname); 495 slice++; 496 continue; 497 } 498 sp = &ssp->dss_slices[slice]; 499 if (mbr_setslice(sname, info, sp, dp, ext_offset) != 0) 500 continue; 501 slice++; 502 } 503 } 504 ssp->dss_nslices = slice; 505 506 /* If we found any more slices, recursively find all the subslices. */ 507 for (dospart = 0; dospart < NDOSPART; dospart++) { 508 if (ext_sizes[dospart] != 0) { 509 mbr_extended(dev, info, ssp, ext_offsets[dospart], 510 ext_sizes[dospart], base_ext_offset, 511 nsectors, ntracks, mbr_offset, ++level); 512 } 513 } 514 515 done: 516 bp->b_flags |= B_INVAL | B_AGE; 517 relpbuf(bp, NULL); 518 } 519 520 static int 521 mbr_setslice(char *sname, struct disk_info *info, struct diskslice *sp, 522 struct dos_partition *dp, u_int64_t br_offset) 523 { 524 u_int64_t offset; 525 u_int64_t size; 526 527 offset = br_offset + dp->dp_start; 528 if (offset > info->d_media_blocks || offset < br_offset) { 529 kprintf( 530 "%s: slice starts beyond end of the disk: rejecting it\n", 531 sname); 532 return (1); 533 } 534 size = info->d_media_blocks - offset; 535 if (size >= dp->dp_size) { 536 if (dp->dp_size == 0xFFFFFFFFU) { 537 kprintf("%s: slice >2TB, using media size instead " 538 "of slice table size\n", sname); 539 } else { 540 size = dp->dp_size; 541 } 542 } else { 543 kprintf("%s: slice extends beyond end of disk: " 544 "truncating from %u to %llu sectors\n", 545 sname, dp->dp_size, (unsigned long long)size); 546 } 547 sp->ds_offset = offset; 548 sp->ds_size = size; 549 sp->ds_type = dp->dp_typ; 550 bzero(&sp->ds_type_uuid, sizeof(sp->ds_type_uuid)); 551 bzero(&sp->ds_stor_uuid, sizeof(sp->ds_type_uuid)); 552 553 /* 554 * Slices do not overlap with the parent (if any). 555 */ 556 sp->ds_reserved = 0; 557 return (0); 558 } 559