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 1.18 2006/12/23 00:35:04 swildner 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/disklabel.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/malloc.h> 53 #include <sys/syslog.h> 54 #include <sys/device.h> 55 56 #define TRACE(str) do { if (dsi_debug) kprintf str; } while (0) 57 58 static volatile u_char dsi_debug; 59 60 /* 61 * This is what we have embedded in every boot1 for supporting the bogus 62 * "Dangerously Dedicated" mode. However, the old table is broken because 63 * it has an illegal geometry in it - it specifies 256 heads (heads = end 64 * head + 1) which causes nasty stuff when that wraps to zero in bios code. 65 * eg: divide by zero etc. This caused the dead-thinkpad problem, numerous 66 * SCSI bios crashes, EFI to crash, etc. 67 * 68 * We still have to recognize the old table though, even though we stopped 69 * inflicting it upon the world. 70 */ 71 static struct dos_partition historical_bogus_partition_table[NDOSPART] = { 72 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 73 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 74 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 75 { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, }, 76 }; 77 static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = { 78 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 79 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 80 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 81 { 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, }, 82 }; 83 84 static int check_part (char *sname, struct dos_partition *dp, 85 u_long offset, int nsectors, int ntracks, 86 u_long mbr_offset); 87 static void mbr_extended (cdev_t dev, struct disklabel *lp, 88 struct diskslices *ssp, u_long ext_offset, 89 u_long ext_size, u_long base_ext_offset, 90 int nsectors, int ntracks, u_long mbr_offset, 91 int level); 92 static int mbr_setslice (char *sname, struct disklabel *lp, 93 struct diskslice *sp, struct dos_partition *dp, 94 u_long br_offset); 95 96 static int 97 check_part(char *sname, struct dos_partition *dp, u_long offset, 98 int nsectors, int ntracks, u_long mbr_offset) 99 { 100 int chs_ecyl; 101 int chs_esect; 102 int chs_scyl; 103 int chs_ssect; 104 int error; 105 u_long esector; 106 u_long esector1; 107 u_long secpercyl; 108 u_long ssector; 109 u_long ssector1; 110 111 secpercyl = (u_long)nsectors * ntracks; 112 chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect); 113 chs_ssect = DPSECT(dp->dp_ssect); 114 ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl 115 + mbr_offset; 116 ssector1 = offset + dp->dp_start; 117 118 /* 119 * If ssector1 is on a cylinder >= 1024, then ssector can't be right. 120 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct 121 * apart from the cylinder being reduced modulo 1024. Always allow 122 * 1023/255/63, because this is the official way to represent 123 * pure-LBA for the starting position. 124 */ 125 if ((ssector < ssector1 126 && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1 127 && chs_scyl == 1023) 128 || (secpercyl != 0 129 && (ssector1 - ssector) % (1024 * secpercyl) == 0))) 130 || (dp->dp_scyl == 255 && dp->dp_shd == 255 131 && dp->dp_ssect == 255)) { 132 TRACE(("%s: C/H/S start %d/%d/%d, start %lu: allow\n", 133 sname, chs_scyl, dp->dp_shd, chs_ssect, ssector1)); 134 ssector = ssector1; 135 } 136 137 chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect); 138 chs_esect = DPSECT(dp->dp_esect); 139 esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl 140 + mbr_offset; 141 esector1 = ssector1 + dp->dp_size - 1; 142 143 /* 144 * Allow certain bogus C/H/S values for esector, as above. However, 145 * heads == 255 isn't really legal and causes some BIOS crashes. The 146 * correct value to indicate a pure-LBA end is 1023/heads-1/sectors - 147 * usually 1023/254/63. "heads" is base 0, "sectors" is base 1. 148 */ 149 if ((esector < esector1 150 && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1 151 && chs_ecyl == 1023) 152 || (secpercyl != 0 153 && (esector1 - esector) % (1024 * secpercyl) == 0))) 154 || (dp->dp_ecyl == 255 && dp->dp_ehd == 255 155 && dp->dp_esect == 255)) { 156 TRACE(("%s: C/H/S end %d/%d/%d, end %lu: allow\n", 157 sname, chs_ecyl, dp->dp_ehd, chs_esect, esector1)); 158 esector = esector1; 159 } 160 161 error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL; 162 if (bootverbose) 163 kprintf("%s: type 0x%x, start %lu, end = %lu, size %lu %s\n", 164 sname, dp->dp_typ, ssector1, esector1, 165 (u_long)dp->dp_size, error ? "" : ": OK"); 166 if (ssector != ssector1 && bootverbose) 167 kprintf("%s: C/H/S start %d/%d/%d (%lu) != start %lu: invalid\n", 168 sname, chs_scyl, dp->dp_shd, chs_ssect, 169 ssector, ssector1); 170 if (esector != esector1 && bootverbose) 171 kprintf("%s: C/H/S end %d/%d/%d (%lu) != end %lu: invalid\n", 172 sname, chs_ecyl, dp->dp_ehd, chs_esect, 173 esector, esector1); 174 return (error); 175 } 176 177 int 178 dsinit(cdev_t dev, struct disklabel *lp, struct diskslices **sspp) 179 { 180 struct buf *bp; 181 u_char *cp; 182 int dospart; 183 struct dos_partition *dp; 184 struct dos_partition *dp0; 185 struct dos_partition dpcopy[NDOSPART]; 186 int error; 187 int max_ncyls; 188 int max_nsectors; 189 int max_ntracks; 190 u_long mbr_offset; 191 char partname[2]; 192 u_long secpercyl; 193 char *sname; 194 struct diskslice *sp; 195 struct diskslices *ssp; 196 cdev_t wdev; 197 198 mbr_offset = DOSBBSECTOR; 199 reread_mbr: 200 /* Read master boot record. */ 201 wdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART); 202 bp = geteblk((int)lp->d_secsize); 203 bp->b_bio1.bio_offset = (off_t)mbr_offset * lp->d_secsize; 204 bp->b_bcount = lp->d_secsize; 205 bp->b_cmd = BUF_CMD_READ; 206 dev_dstrategy(wdev, &bp->b_bio1); 207 if (biowait(bp) != 0) { 208 diskerr(&bp->b_bio1, wdev, 209 "reading primary partition table: error", 210 LOG_PRINTF, 0, NULL); 211 kprintf("\n"); 212 error = EIO; 213 goto done; 214 } 215 216 /* Weakly verify it. */ 217 cp = bp->b_data; 218 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART, partname); 219 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 220 if (bootverbose) 221 kprintf("%s: invalid primary partition table: no magic\n", 222 sname); 223 error = EINVAL; 224 goto done; 225 } 226 227 /* Make a copy of the partition table to avoid alignment problems. */ 228 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 229 230 dp0 = &dpcopy[0]; 231 232 /* Check for "Ontrack Diskmanager". */ 233 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 234 if (dp->dp_typ == DOSPTYP_ONTRACK) { 235 if (bootverbose) 236 kprintf( 237 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname); 238 bp->b_flags |= B_INVAL | B_AGE; 239 brelse(bp); 240 mbr_offset = 63; 241 goto reread_mbr; 242 } 243 } 244 245 if (bcmp(dp0, historical_bogus_partition_table, 246 sizeof historical_bogus_partition_table) == 0 || 247 bcmp(dp0, historical_bogus_partition_table_fixed, 248 sizeof historical_bogus_partition_table_fixed) == 0) { 249 #if 0 250 TRACE(("%s: invalid primary partition table: historical\n", 251 sname)); 252 #endif /* 0 */ 253 if (bootverbose) 254 kprintf( 255 "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n", 256 sname); 257 error = EINVAL; 258 goto done; 259 } 260 261 /* Guess the geometry. */ 262 /* 263 * TODO: 264 * Perhaps skip entries with 0 size. 265 * Perhaps only look at entries of type DOSPTYP_386BSD. 266 */ 267 max_ncyls = 0; 268 max_nsectors = 0; 269 max_ntracks = 0; 270 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 271 int ncyls; 272 int nsectors; 273 int ntracks; 274 275 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1; 276 if (max_ncyls < ncyls) 277 max_ncyls = ncyls; 278 nsectors = DPSECT(dp->dp_esect); 279 if (max_nsectors < nsectors) 280 max_nsectors = nsectors; 281 ntracks = dp->dp_ehd + 1; 282 if (max_ntracks < ntracks) 283 max_ntracks = ntracks; 284 } 285 286 /* 287 * Check that we have guessed the geometry right by checking the 288 * partition entries. 289 */ 290 /* 291 * TODO: 292 * As above. 293 * Check for overlaps. 294 * Check against d_secperunit if the latter is reliable. 295 */ 296 error = 0; 297 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 298 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 299 && dp->dp_start == 0 && dp->dp_size == 0) 300 continue; 301 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 302 RAW_PART, partname); 303 304 /* 305 * Temporarily ignore errors from this check. We could 306 * simplify things by accepting the table eariler if we 307 * always ignore errors here. Perhaps we should always 308 * accept the table if the magic is right but not let 309 * bad entries affect the geometry. 310 */ 311 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks, 312 mbr_offset); 313 } 314 if (error != 0) 315 goto done; 316 317 /* 318 * Accept the DOS partition table. 319 * First adjust the label (we have been careful not to change it 320 * before we can guarantee success). 321 */ 322 secpercyl = (u_long)max_nsectors * max_ntracks; 323 if (secpercyl != 0) { 324 #if 0 325 u_long secperunit; 326 #endif 327 328 lp->d_nsectors = max_nsectors; 329 lp->d_ntracks = max_ntracks; 330 lp->d_secpercyl = secpercyl; 331 /* 332 * Temporarily, don't even consider adjusting the drive's 333 * size, since the adjusted size may exceed the hardware's 334 * addressing capabilities. The adjustment helped mainly 335 * for ancient MFM drives with > 1024 cylinders, but now 336 * breaks at least IDE drives with 63*16*65536 sectors if 337 * they are controlled by the wd driver in CHS mode. 338 */ 339 #if 0 340 secperunit = secpercyl * max_ncyls; 341 if (lp->d_secperunit < secperunit) 342 lp->d_secperunit = secperunit; 343 #endif 344 lp->d_ncylinders = lp->d_secperunit / secpercyl; 345 } 346 347 /* 348 * We are passed a pointer to a suitably initialized minimal 349 * slices "struct" with no dangling pointers in it. Replace it 350 * by a maximal one. This usually oversizes the "struct", but 351 * enlarging it while searching for logical drives would be 352 * inconvenient. 353 */ 354 kfree(*sspp, M_DEVBUF); 355 ssp = dsmakeslicestruct(MAX_SLICES, lp); 356 *sspp = ssp; 357 358 /* Initialize normal slices. */ 359 sp = &ssp->dss_slices[BASE_SLICE]; 360 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) { 361 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 362 RAW_PART, partname); 363 (void)mbr_setslice(sname, lp, sp, dp, mbr_offset); 364 } 365 ssp->dss_nslices = BASE_SLICE + NDOSPART; 366 367 /* Handle extended partitions. */ 368 sp -= NDOSPART; 369 for (dospart = 0; dospart < NDOSPART; dospart++, sp++) { 370 if (sp->ds_type == DOSPTYP_EXTENDED || 371 sp->ds_type == DOSPTYP_EXTENDEDX) { 372 mbr_extended(wdev, lp, ssp, 373 sp->ds_offset, sp->ds_size, sp->ds_offset, 374 max_nsectors, max_ntracks, mbr_offset, 1); 375 } 376 } 377 378 /* 379 * mbr_extended() abuses ssp->dss_nslices for the number of slices 380 * that would be found if there were no limit on the number of slices 381 * in *ssp. Cut it back now. 382 */ 383 if (ssp->dss_nslices > MAX_SLICES) 384 ssp->dss_nslices = MAX_SLICES; 385 386 done: 387 bp->b_flags |= B_INVAL | B_AGE; 388 brelse(bp); 389 if (error == EINVAL) 390 error = 0; 391 return (error); 392 } 393 394 void 395 mbr_extended(cdev_t dev, struct disklabel *lp, struct diskslices *ssp, 396 u_long ext_offset, u_long ext_size, u_long base_ext_offset, 397 int nsectors, int ntracks, u_long mbr_offset, int level) 398 { 399 struct buf *bp; 400 u_char *cp; 401 int dospart; 402 struct dos_partition *dp; 403 struct dos_partition dpcopy[NDOSPART]; 404 u_long ext_offsets[NDOSPART]; 405 u_long ext_sizes[NDOSPART]; 406 char partname[2]; 407 int slice; 408 char *sname; 409 struct diskslice *sp; 410 411 if (level >= 16) { 412 kprintf( 413 "%s: excessive recursion in search for slices; aborting search\n", 414 devtoname(dev)); 415 return; 416 } 417 418 /* Read extended boot record. */ 419 bp = geteblk((int)lp->d_secsize); 420 bp->b_bio1.bio_offset = (off_t)ext_offset * lp->d_secsize; 421 bp->b_bcount = lp->d_secsize; 422 bp->b_cmd = BUF_CMD_READ; 423 dev_dstrategy(dev, &bp->b_bio1); 424 if (biowait(bp) != 0) { 425 diskerr(&bp->b_bio1, dev, 426 "reading extended partition table: error", 427 LOG_PRINTF, 0, NULL); 428 kprintf("\n"); 429 goto done; 430 } 431 432 /* Weakly verify it. */ 433 cp = bp->b_data; 434 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 435 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART, 436 partname); 437 if (bootverbose) 438 kprintf("%s: invalid extended partition table: no magic\n", 439 sname); 440 goto done; 441 } 442 443 /* Make a copy of the partition table to avoid alignment problems. */ 444 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 445 446 slice = ssp->dss_nslices; 447 for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART; 448 dospart++, dp++) { 449 ext_sizes[dospart] = 0; 450 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 451 && dp->dp_start == 0 && dp->dp_size == 0) 452 continue; 453 if (dp->dp_typ == DOSPTYP_EXTENDED || 454 dp->dp_typ == DOSPTYP_EXTENDEDX) { 455 static char buf[32]; 456 457 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, 458 RAW_PART, partname); 459 ksnprintf(buf, sizeof(buf), "%s", sname); 460 if (strlen(buf) < sizeof buf - 11) 461 strcat(buf, "<extended>"); 462 check_part(buf, dp, base_ext_offset, nsectors, 463 ntracks, mbr_offset); 464 ext_offsets[dospart] = base_ext_offset + dp->dp_start; 465 ext_sizes[dospart] = dp->dp_size; 466 } else { 467 sname = dsname(dev, dkunit(dev), slice, RAW_PART, 468 partname); 469 check_part(sname, dp, ext_offset, nsectors, ntracks, 470 mbr_offset); 471 if (slice >= MAX_SLICES) { 472 kprintf("%s: too many slices\n", sname); 473 slice++; 474 continue; 475 } 476 sp = &ssp->dss_slices[slice]; 477 if (mbr_setslice(sname, lp, sp, dp, ext_offset) != 0) 478 continue; 479 slice++; 480 } 481 } 482 ssp->dss_nslices = slice; 483 484 /* If we found any more slices, recursively find all the subslices. */ 485 for (dospart = 0; dospart < NDOSPART; dospart++) { 486 if (ext_sizes[dospart] != 0) { 487 mbr_extended(dev, lp, ssp, ext_offsets[dospart], 488 ext_sizes[dospart], base_ext_offset, 489 nsectors, ntracks, mbr_offset, ++level); 490 } 491 } 492 493 done: 494 bp->b_flags |= B_INVAL | B_AGE; 495 brelse(bp); 496 } 497 498 static int 499 mbr_setslice(char *sname, struct disklabel *lp, struct diskslice *sp, 500 struct dos_partition *dp, u_long br_offset) 501 { 502 u_long offset; 503 u_long size; 504 505 offset = br_offset + dp->dp_start; 506 if (offset > lp->d_secperunit || offset < br_offset) { 507 kprintf( 508 "%s: slice starts beyond end of the disk: rejecting it\n", 509 sname); 510 return (1); 511 } 512 size = lp->d_secperunit - offset; 513 if (size >= dp->dp_size) 514 size = dp->dp_size; 515 else 516 kprintf( 517 "%s: slice extends beyond end of disk: truncating from %lu to %lu sectors\n", 518 sname, (u_long)dp->dp_size, size); 519 sp->ds_offset = offset; 520 sp->ds_size = size; 521 sp->ds_type = dp->dp_typ; 522 #if 0 523 lp->d_subtype |= (lp->d_subtype & 3) | dospart | DSTYPE_INDOSPART; 524 #endif 525 return (0); 526 } 527