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 1.11 2006/02/17 19:18:06 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/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) printf str; } while (0) 57 58 static volatile u_char dsi_debug; 59 60 static struct dos_partition historical_bogus_partition_table[NDOSPART] = { 61 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 62 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 63 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, 64 { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, }, 65 }; 66 67 static int check_part (char *sname, struct dos_partition *dp, 68 u_long offset, int nsectors, int ntracks, 69 u_long mbr_offset); 70 static void mbr_extended (dev_t dev, struct disklabel *lp, 71 struct diskslices *ssp, u_long ext_offset, 72 u_long ext_size, u_long base_ext_offset, 73 int nsectors, int ntracks, u_long mbr_offset, 74 int level); 75 static int mbr_setslice (char *sname, struct disklabel *lp, 76 struct diskslice *sp, struct dos_partition *dp, 77 u_long br_offset); 78 79 static int 80 check_part(char *sname, struct dos_partition *dp, u_long offset, 81 int nsectors, int ntracks, u_long mbr_offset) 82 { 83 int chs_ecyl; 84 int chs_esect; 85 int chs_scyl; 86 int chs_ssect; 87 int error; 88 u_long esector; 89 u_long esector1; 90 u_long secpercyl; 91 u_long ssector; 92 u_long ssector1; 93 94 secpercyl = (u_long)nsectors * ntracks; 95 chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect); 96 chs_ssect = DPSECT(dp->dp_ssect); 97 ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl 98 + mbr_offset; 99 ssector1 = offset + dp->dp_start; 100 101 /* 102 * If ssector1 is on a cylinder >= 1024, then ssector can't be right. 103 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct 104 * apart from the cylinder being reduced modulo 1024. Always allow 105 * 1023/255/63. 106 */ 107 if ((ssector < ssector1 108 && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1 109 && chs_scyl == 1023) 110 || (secpercyl != 0 111 && (ssector1 - ssector) % (1024 * secpercyl) == 0))) 112 || (dp->dp_scyl == 255 && dp->dp_shd == 255 113 && dp->dp_ssect == 255)) { 114 TRACE(("%s: C/H/S start %d/%d/%d, start %lu: allow\n", 115 sname, chs_scyl, dp->dp_shd, chs_ssect, ssector1)); 116 ssector = ssector1; 117 } 118 119 chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect); 120 chs_esect = DPSECT(dp->dp_esect); 121 esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl 122 + mbr_offset; 123 esector1 = ssector1 + dp->dp_size - 1; 124 125 /* Allow certain bogus C/H/S values for esector, as above. */ 126 if ((esector < esector1 127 && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1 128 && chs_ecyl == 1023) 129 || (secpercyl != 0 130 && (esector1 - esector) % (1024 * secpercyl) == 0))) 131 || (dp->dp_ecyl == 255 && dp->dp_ehd == 255 132 && dp->dp_esect == 255)) { 133 TRACE(("%s: C/H/S end %d/%d/%d, end %lu: allow\n", 134 sname, chs_ecyl, dp->dp_ehd, chs_esect, esector1)); 135 esector = esector1; 136 } 137 138 error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL; 139 if (bootverbose) 140 printf("%s: type 0x%x, start %lu, end = %lu, size %lu %s\n", 141 sname, dp->dp_typ, ssector1, esector1, 142 (u_long)dp->dp_size, error ? "" : ": OK"); 143 if (ssector != ssector1 && bootverbose) 144 printf("%s: C/H/S start %d/%d/%d (%lu) != start %lu: invalid\n", 145 sname, chs_scyl, dp->dp_shd, chs_ssect, 146 ssector, ssector1); 147 if (esector != esector1 && bootverbose) 148 printf("%s: C/H/S end %d/%d/%d (%lu) != end %lu: invalid\n", 149 sname, chs_ecyl, dp->dp_ehd, chs_esect, 150 esector, esector1); 151 return (error); 152 } 153 154 int 155 dsinit(dev_t dev, struct disklabel *lp, struct diskslices **sspp) 156 { 157 struct buf *bp; 158 u_char *cp; 159 int dospart; 160 struct dos_partition *dp; 161 struct dos_partition *dp0; 162 struct dos_partition dpcopy[NDOSPART]; 163 int error; 164 int max_ncyls; 165 int max_nsectors; 166 int max_ntracks; 167 u_long mbr_offset; 168 char partname[2]; 169 u_long secpercyl; 170 char *sname; 171 struct diskslice *sp; 172 struct diskslices *ssp; 173 dev_t wdev; 174 175 mbr_offset = DOSBBSECTOR; 176 reread_mbr: 177 /* Read master boot record. */ 178 wdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART); 179 bp = geteblk((int)lp->d_secsize); 180 bp->b_bio1.bio_blkno = mbr_offset; 181 bp->b_bcount = lp->d_secsize; 182 bp->b_flags |= B_READ; 183 dev_dstrategy(wdev, &bp->b_bio1); 184 if (biowait(bp) != 0) { 185 diskerr(&bp->b_bio1, wdev, 186 "reading primary partition table: error", 187 LOG_PRINTF, 0, (struct disklabel *)NULL); 188 printf("\n"); 189 error = EIO; 190 goto done; 191 } 192 193 /* Weakly verify it. */ 194 cp = bp->b_data; 195 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART, partname); 196 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 197 if (bootverbose) 198 printf("%s: invalid primary partition table: no magic\n", 199 sname); 200 error = EINVAL; 201 goto done; 202 } 203 204 /* Make a copy of the partition table to avoid alignment problems. */ 205 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 206 207 dp0 = &dpcopy[0]; 208 209 /* Check for "Ontrack Diskmanager". */ 210 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 211 if (dp->dp_typ == DOSPTYP_ONTRACK) { 212 if (bootverbose) 213 printf( 214 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname); 215 bp->b_flags |= B_INVAL | B_AGE; 216 brelse(bp); 217 mbr_offset = 63; 218 goto reread_mbr; 219 } 220 } 221 222 if (bcmp(dp0, historical_bogus_partition_table, 223 sizeof historical_bogus_partition_table) == 0) { 224 TRACE(("%s: invalid primary partition table: historical\n", 225 sname)); 226 error = EINVAL; 227 goto done; 228 } 229 230 /* Guess the geometry. */ 231 /* 232 * TODO: 233 * Perhaps skip entries with 0 size. 234 * Perhaps only look at entries of type DOSPTYP_386BSD. 235 */ 236 max_ncyls = 0; 237 max_nsectors = 0; 238 max_ntracks = 0; 239 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 240 int ncyls; 241 int nsectors; 242 int ntracks; 243 244 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1; 245 if (max_ncyls < ncyls) 246 max_ncyls = ncyls; 247 nsectors = DPSECT(dp->dp_esect); 248 if (max_nsectors < nsectors) 249 max_nsectors = nsectors; 250 ntracks = dp->dp_ehd + 1; 251 if (max_ntracks < ntracks) 252 max_ntracks = ntracks; 253 } 254 255 /* 256 * Check that we have guessed the geometry right by checking the 257 * partition entries. 258 */ 259 /* 260 * TODO: 261 * As above. 262 * Check for overlaps. 263 * Check against d_secperunit if the latter is reliable. 264 */ 265 error = 0; 266 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) { 267 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 268 && dp->dp_start == 0 && dp->dp_size == 0) 269 continue; 270 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 271 RAW_PART, partname); 272 273 /* 274 * Temporarily ignore errors from this check. We could 275 * simplify things by accepting the table eariler if we 276 * always ignore errors here. Perhaps we should always 277 * accept the table if the magic is right but not let 278 * bad entries affect the geometry. 279 */ 280 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks, 281 mbr_offset); 282 } 283 if (error != 0) 284 goto done; 285 286 /* 287 * Accept the DOS partition table. 288 * First adjust the label (we have been careful not to change it 289 * before we can guarantee success). 290 */ 291 secpercyl = (u_long)max_nsectors * max_ntracks; 292 if (secpercyl != 0) { 293 #if 0 294 u_long secperunit; 295 #endif 296 297 lp->d_nsectors = max_nsectors; 298 lp->d_ntracks = max_ntracks; 299 lp->d_secpercyl = secpercyl; 300 /* 301 * Temporarily, don't even consider adjusting the drive's 302 * size, since the adjusted size may exceed the hardware's 303 * addressing capabilities. The adjustment helped mainly 304 * for ancient MFM drives with > 1024 cylinders, but now 305 * breaks at least IDE drives with 63*16*65536 sectors if 306 * they are controlled by the wd driver in CHS mode. 307 */ 308 #if 0 309 secperunit = secpercyl * max_ncyls; 310 if (lp->d_secperunit < secperunit) 311 lp->d_secperunit = secperunit; 312 #endif 313 lp->d_ncylinders = lp->d_secperunit / secpercyl; 314 } 315 316 /* 317 * We are passed a pointer to a suitably initialized minimal 318 * slices "struct" with no dangling pointers in it. Replace it 319 * by a maximal one. This usually oversizes the "struct", but 320 * enlarging it while searching for logical drives would be 321 * inconvenient. 322 */ 323 free(*sspp, M_DEVBUF); 324 ssp = dsmakeslicestruct(MAX_SLICES, lp); 325 *sspp = ssp; 326 327 /* Initialize normal slices. */ 328 sp = &ssp->dss_slices[BASE_SLICE]; 329 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) { 330 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart, 331 RAW_PART, partname); 332 (void)mbr_setslice(sname, lp, sp, dp, mbr_offset); 333 } 334 ssp->dss_nslices = BASE_SLICE + NDOSPART; 335 336 /* Handle extended partitions. */ 337 sp -= NDOSPART; 338 for (dospart = 0; dospart < NDOSPART; dospart++, sp++) { 339 if (sp->ds_type == DOSPTYP_EXTENDED || 340 sp->ds_type == DOSPTYP_EXTENDEDX) { 341 mbr_extended(wdev, lp, ssp, 342 sp->ds_offset, sp->ds_size, sp->ds_offset, 343 max_nsectors, max_ntracks, mbr_offset, 1); 344 } 345 } 346 347 /* 348 * mbr_extended() abuses ssp->dss_nslices for the number of slices 349 * that would be found if there were no limit on the number of slices 350 * in *ssp. Cut it back now. 351 */ 352 if (ssp->dss_nslices > MAX_SLICES) 353 ssp->dss_nslices = MAX_SLICES; 354 355 done: 356 bp->b_flags |= B_INVAL | B_AGE; 357 brelse(bp); 358 if (error == EINVAL) 359 error = 0; 360 return (error); 361 } 362 363 void 364 mbr_extended(dev_t dev, struct disklabel *lp, struct diskslices *ssp, 365 u_long ext_offset, u_long ext_size, u_long base_ext_offset, 366 int nsectors, int ntracks, u_long mbr_offset, int level) 367 { 368 struct buf *bp; 369 u_char *cp; 370 int dospart; 371 struct dos_partition *dp; 372 struct dos_partition dpcopy[NDOSPART]; 373 u_long ext_offsets[NDOSPART]; 374 u_long ext_sizes[NDOSPART]; 375 char partname[2]; 376 int slice; 377 char *sname; 378 struct diskslice *sp; 379 380 if (level >= 16) { 381 printf( 382 "%s: excessive recursion in search for slices; aborting search\n", 383 devtoname(dev)); 384 return; 385 } 386 387 /* Read extended boot record. */ 388 bp = geteblk((int)lp->d_secsize); 389 bp->b_bio1.bio_blkno = ext_offset; 390 bp->b_bcount = lp->d_secsize; 391 bp->b_flags |= B_READ; 392 dev_dstrategy(dev, &bp->b_bio1); 393 if (biowait(bp) != 0) { 394 diskerr(&bp->b_bio1, dev, 395 "reading extended partition table: error", 396 LOG_PRINTF, 0, (struct disklabel *)NULL); 397 printf("\n"); 398 goto done; 399 } 400 401 /* Weakly verify it. */ 402 cp = bp->b_data; 403 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) { 404 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART, 405 partname); 406 if (bootverbose) 407 printf("%s: invalid extended partition table: no magic\n", 408 sname); 409 goto done; 410 } 411 412 /* Make a copy of the partition table to avoid alignment problems. */ 413 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy)); 414 415 slice = ssp->dss_nslices; 416 for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART; 417 dospart++, dp++) { 418 ext_sizes[dospart] = 0; 419 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0 420 && dp->dp_start == 0 && dp->dp_size == 0) 421 continue; 422 if (dp->dp_typ == DOSPTYP_EXTENDED || 423 dp->dp_typ == DOSPTYP_EXTENDEDX) { 424 static char buf[32]; 425 426 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, 427 RAW_PART, partname); 428 snprintf(buf, sizeof(buf), "%s", sname); 429 if (strlen(buf) < sizeof buf - 11) 430 strcat(buf, "<extended>"); 431 check_part(buf, dp, base_ext_offset, nsectors, 432 ntracks, mbr_offset); 433 ext_offsets[dospart] = base_ext_offset + dp->dp_start; 434 ext_sizes[dospart] = dp->dp_size; 435 } else { 436 sname = dsname(dev, dkunit(dev), slice, RAW_PART, 437 partname); 438 check_part(sname, dp, ext_offset, nsectors, ntracks, 439 mbr_offset); 440 if (slice >= MAX_SLICES) { 441 printf("%s: too many slices\n", sname); 442 slice++; 443 continue; 444 } 445 sp = &ssp->dss_slices[slice]; 446 if (mbr_setslice(sname, lp, sp, dp, ext_offset) != 0) 447 continue; 448 slice++; 449 } 450 } 451 ssp->dss_nslices = slice; 452 453 /* If we found any more slices, recursively find all the subslices. */ 454 for (dospart = 0; dospart < NDOSPART; dospart++) { 455 if (ext_sizes[dospart] != 0) { 456 mbr_extended(dev, lp, ssp, ext_offsets[dospart], 457 ext_sizes[dospart], base_ext_offset, 458 nsectors, ntracks, mbr_offset, ++level); 459 } 460 } 461 462 done: 463 bp->b_flags |= B_INVAL | B_AGE; 464 brelse(bp); 465 } 466 467 static int 468 mbr_setslice(char *sname, struct disklabel *lp, struct diskslice *sp, 469 struct dos_partition *dp, u_long br_offset) 470 { 471 u_long offset; 472 u_long size; 473 474 offset = br_offset + dp->dp_start; 475 if (offset > lp->d_secperunit || offset < br_offset) { 476 printf( 477 "%s: slice starts beyond end of the disk: rejecting it\n", 478 sname); 479 return (1); 480 } 481 size = lp->d_secperunit - offset; 482 if (size >= dp->dp_size) 483 size = dp->dp_size; 484 else 485 printf( 486 "%s: slice extends beyond end of disk: truncating from %lu to %lu sectors\n", 487 sname, (u_long)dp->dp_size, size); 488 sp->ds_offset = offset; 489 sp->ds_size = size; 490 sp->ds_type = dp->dp_typ; 491 #if 0 492 lp->d_subtype |= (lp->d_subtype & 3) | dospart | DSTYPE_INDOSPART; 493 #endif 494 return (0); 495 } 496