g_part_mbr.c revision 265910
1/*- 2 * Copyright (c) 2007, 2008 Marcel Moolenaar 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 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: stable/10/sys/geom/part/g_part_mbr.c 265910 2014-05-12 10:19:31Z ae $"); 29 30#include <sys/param.h> 31#include <sys/bio.h> 32#include <sys/diskmbr.h> 33#include <sys/endian.h> 34#include <sys/kernel.h> 35#include <sys/kobj.h> 36#include <sys/limits.h> 37#include <sys/lock.h> 38#include <sys/malloc.h> 39#include <sys/mutex.h> 40#include <sys/queue.h> 41#include <sys/sbuf.h> 42#include <sys/systm.h> 43#include <sys/sysctl.h> 44#include <geom/geom.h> 45#include <geom/geom_int.h> 46#include <geom/part/g_part.h> 47 48#include "g_part_if.h" 49 50FEATURE(geom_part_mbr, "GEOM partitioning class for MBR support"); 51 52#define MBRSIZE 512 53 54struct g_part_mbr_table { 55 struct g_part_table base; 56 u_char mbr[MBRSIZE]; 57}; 58 59struct g_part_mbr_entry { 60 struct g_part_entry base; 61 struct dos_partition ent; 62}; 63 64static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *, 65 struct g_part_parms *); 66static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *); 67static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *); 68static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *); 69static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *, 70 struct sbuf *, const char *); 71static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *); 72static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *, 73 struct g_part_parms *); 74static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *, 75 char *, size_t); 76static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *); 77static int g_part_mbr_read(struct g_part_table *, struct g_consumer *); 78static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *, 79 const char *, unsigned int); 80static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *, 81 char *, size_t); 82static int g_part_mbr_write(struct g_part_table *, struct g_consumer *); 83static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *, 84 struct g_part_parms *); 85 86static kobj_method_t g_part_mbr_methods[] = { 87 KOBJMETHOD(g_part_add, g_part_mbr_add), 88 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode), 89 KOBJMETHOD(g_part_create, g_part_mbr_create), 90 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy), 91 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf), 92 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto), 93 KOBJMETHOD(g_part_modify, g_part_mbr_modify), 94 KOBJMETHOD(g_part_resize, g_part_mbr_resize), 95 KOBJMETHOD(g_part_name, g_part_mbr_name), 96 KOBJMETHOD(g_part_probe, g_part_mbr_probe), 97 KOBJMETHOD(g_part_read, g_part_mbr_read), 98 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset), 99 KOBJMETHOD(g_part_type, g_part_mbr_type), 100 KOBJMETHOD(g_part_write, g_part_mbr_write), 101 { 0, 0 } 102}; 103 104static struct g_part_scheme g_part_mbr_scheme = { 105 "MBR", 106 g_part_mbr_methods, 107 sizeof(struct g_part_mbr_table), 108 .gps_entrysz = sizeof(struct g_part_mbr_entry), 109 .gps_minent = NDOSPART, 110 .gps_maxent = NDOSPART, 111 .gps_bootcodesz = MBRSIZE, 112}; 113G_PART_SCHEME_DECLARE(g_part_mbr); 114 115static struct g_part_mbr_alias { 116 u_char typ; 117 int alias; 118} mbr_alias_match[] = { 119 { DOSPTYP_386BSD, G_PART_ALIAS_FREEBSD }, 120 { DOSPTYP_EXT, G_PART_ALIAS_EBR }, 121 { DOSPTYP_NTFS, G_PART_ALIAS_MS_NTFS }, 122 { DOSPTYP_FAT16, G_PART_ALIAS_MS_FAT16 }, 123 { DOSPTYP_FAT32, G_PART_ALIAS_MS_FAT32 }, 124 { DOSPTYP_EXTLBA, G_PART_ALIAS_EBR }, 125 { DOSPTYP_LDM, G_PART_ALIAS_MS_LDM_DATA }, 126 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP }, 127 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA }, 128 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM }, 129 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID }, 130 { DOSPTYP_PPCBOOT, G_PART_ALIAS_FREEBSD_BOOT }, 131 { DOSPTYP_VMFS, G_PART_ALIAS_VMFS }, 132 { DOSPTYP_VMKDIAG, G_PART_ALIAS_VMKDIAG }, 133}; 134 135static int 136mbr_parse_type(const char *type, u_char *dp_typ) 137{ 138 const char *alias; 139 char *endp; 140 long lt; 141 int i; 142 143 if (type[0] == '!') { 144 lt = strtol(type + 1, &endp, 0); 145 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256) 146 return (EINVAL); 147 *dp_typ = (u_char)lt; 148 return (0); 149 } 150 for (i = 0; 151 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 152 alias = g_part_alias_name(mbr_alias_match[i].alias); 153 if (strcasecmp(type, alias) == 0) { 154 *dp_typ = mbr_alias_match[i].typ; 155 return (0); 156 } 157 } 158 return (EINVAL); 159} 160 161static int 162mbr_probe_bpb(u_char *bpb) 163{ 164 uint16_t secsz; 165 uint8_t clstsz; 166 167#define PO2(x) ((x & (x - 1)) == 0) 168 secsz = le16dec(bpb); 169 if (secsz < 512 || secsz > 4096 || !PO2(secsz)) 170 return (0); 171 clstsz = bpb[2]; 172 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz)) 173 return (0); 174#undef PO2 175 176 return (1); 177} 178 179static void 180mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp, 181 u_char *secp) 182{ 183 uint32_t cyl, hd, sec; 184 185 sec = lba % table->gpt_sectors + 1; 186 lba /= table->gpt_sectors; 187 hd = lba % table->gpt_heads; 188 lba /= table->gpt_heads; 189 cyl = lba; 190 if (cyl > 1023) 191 sec = hd = cyl = ~0; 192 193 *cylp = cyl & 0xff; 194 *hdp = hd & 0xff; 195 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 196} 197 198static int 199mbr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size) 200{ 201 uint32_t sectors; 202 203 sectors = basetable->gpt_sectors; 204 if (*size < sectors) 205 return (EINVAL); 206 if (start != NULL && (*start % sectors)) { 207 *size += (*start % sectors) - sectors; 208 *start -= (*start % sectors) - sectors; 209 } 210 if (*size % sectors) 211 *size -= (*size % sectors); 212 if (*size < sectors) 213 return (EINVAL); 214 return (0); 215} 216 217static int 218g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry, 219 struct g_part_parms *gpp) 220{ 221 struct g_part_mbr_entry *entry; 222 uint32_t start, size; 223 224 if (gpp->gpp_parms & G_PART_PARM_LABEL) 225 return (EINVAL); 226 227 entry = (struct g_part_mbr_entry *)baseentry; 228 start = gpp->gpp_start; 229 size = gpp->gpp_size; 230 if (mbr_align(basetable, &start, &size) != 0) 231 return (EINVAL); 232 if (baseentry->gpe_deleted) 233 bzero(&entry->ent, sizeof(entry->ent)); 234 235 KASSERT(baseentry->gpe_start <= start, ("%s", __func__)); 236 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__)); 237 baseentry->gpe_start = start; 238 baseentry->gpe_end = start + size - 1; 239 entry->ent.dp_start = start; 240 entry->ent.dp_size = size; 241 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl, 242 &entry->ent.dp_shd, &entry->ent.dp_ssect); 243 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 244 &entry->ent.dp_ehd, &entry->ent.dp_esect); 245 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 246} 247 248static int 249g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp) 250{ 251 struct g_part_mbr_table *table; 252 uint32_t dsn; 253 254 if (gpp->gpp_codesize != MBRSIZE) 255 return (ENODEV); 256 257 table = (struct g_part_mbr_table *)basetable; 258 dsn = *(uint32_t *)(table->mbr + DOSDSNOFF); 259 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF); 260 if (dsn != 0) 261 *(uint32_t *)(table->mbr + DOSDSNOFF) = dsn; 262 return (0); 263} 264 265static int 266g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp) 267{ 268 struct g_provider *pp; 269 struct g_part_mbr_table *table; 270 271 pp = gpp->gpp_provider; 272 if (pp->sectorsize < MBRSIZE) 273 return (ENOSPC); 274 275 basetable->gpt_first = basetable->gpt_sectors; 276 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize, 277 UINT32_MAX) - 1; 278 279 table = (struct g_part_mbr_table *)basetable; 280 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC); 281 return (0); 282} 283 284static int 285g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp) 286{ 287 288 /* Wipe the first sector to clear the partitioning. */ 289 basetable->gpt_smhead |= 1; 290 return (0); 291} 292 293static void 294g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 295 struct sbuf *sb, const char *indent) 296{ 297 struct g_part_mbr_entry *entry; 298 299 entry = (struct g_part_mbr_entry *)baseentry; 300 if (indent == NULL) { 301 /* conftxt: libdisk compatibility */ 302 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ); 303 } else if (entry != NULL) { 304 /* confxml: partition entry information */ 305 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent, 306 entry->ent.dp_typ); 307 if (entry->ent.dp_flag & 0x80) 308 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent); 309 } else { 310 /* confxml: scheme information */ 311 } 312} 313 314static int 315g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry) 316{ 317 struct g_part_mbr_entry *entry; 318 319 /* Allow dumping to a FreeBSD partition or Linux swap partition only. */ 320 entry = (struct g_part_mbr_entry *)baseentry; 321 return ((entry->ent.dp_typ == DOSPTYP_386BSD || 322 entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0); 323} 324 325static int 326g_part_mbr_modify(struct g_part_table *basetable, 327 struct g_part_entry *baseentry, struct g_part_parms *gpp) 328{ 329 struct g_part_mbr_entry *entry; 330 331 if (gpp->gpp_parms & G_PART_PARM_LABEL) 332 return (EINVAL); 333 334 entry = (struct g_part_mbr_entry *)baseentry; 335 if (gpp->gpp_parms & G_PART_PARM_TYPE) 336 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 337 return (0); 338} 339 340static int 341g_part_mbr_resize(struct g_part_table *basetable, 342 struct g_part_entry *baseentry, struct g_part_parms *gpp) 343{ 344 struct g_part_mbr_entry *entry; 345 struct g_provider *pp; 346 uint32_t size; 347 348 size = gpp->gpp_size; 349 if (mbr_align(basetable, NULL, &size) != 0) 350 return (EINVAL); 351 /* XXX: prevent unexpected shrinking. */ 352 pp = baseentry->gpe_pp; 353 if ((g_debugflags & 0x10) == 0 && size < gpp->gpp_size && 354 pp->mediasize / pp->sectorsize > size) 355 return (EBUSY); 356 entry = (struct g_part_mbr_entry *)baseentry; 357 baseentry->gpe_end = baseentry->gpe_start + size - 1; 358 entry->ent.dp_size = size; 359 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 360 &entry->ent.dp_ehd, &entry->ent.dp_esect); 361 return (0); 362} 363 364static const char * 365g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry, 366 char *buf, size_t bufsz) 367{ 368 369 snprintf(buf, bufsz, "s%d", baseentry->gpe_index); 370 return (buf); 371} 372 373static int 374g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp) 375{ 376 char psn[8]; 377 struct g_provider *pp; 378 u_char *buf, *p; 379 int error, index, res, sum; 380 uint16_t magic; 381 382 pp = cp->provider; 383 384 /* Sanity-check the provider. */ 385 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize) 386 return (ENOSPC); 387 if (pp->sectorsize > 4096) 388 return (ENXIO); 389 390 /* We don't nest under an MBR (see EBR instead). */ 391 error = g_getattr("PART::scheme", cp, &psn); 392 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0) 393 return (ELOOP); 394 395 /* Check that there's a MBR. */ 396 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 397 if (buf == NULL) 398 return (error); 399 400 /* We goto out on mismatch. */ 401 res = ENXIO; 402 403 magic = le16dec(buf + DOSMAGICOFFSET); 404 if (magic != DOSMAGIC) 405 goto out; 406 407 for (index = 0; index < NDOSPART; index++) { 408 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 409 if (p[0] != 0 && p[0] != 0x80) 410 goto out; 411 } 412 413 /* 414 * If the partition table does not consist of all zeroes, 415 * assume we have a MBR. If it's all zeroes, we could have 416 * a boot sector. For example, a boot sector that doesn't 417 * have boot code -- common on non-i386 hardware. In that 418 * case we check if we have a possible BPB. If so, then we 419 * assume we have a boot sector instead. 420 */ 421 sum = 0; 422 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++) 423 sum += buf[DOSPARTOFF + index]; 424 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b)) 425 res = G_PART_PROBE_PRI_NORM; 426 427 out: 428 g_free(buf); 429 return (res); 430} 431 432static int 433g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp) 434{ 435 struct dos_partition ent; 436 struct g_provider *pp; 437 struct g_part_mbr_table *table; 438 struct g_part_mbr_entry *entry; 439 u_char *buf, *p; 440 off_t chs, msize, first; 441 u_int sectors, heads; 442 int error, index; 443 444 pp = cp->provider; 445 table = (struct g_part_mbr_table *)basetable; 446 first = basetable->gpt_sectors; 447 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX); 448 449 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 450 if (buf == NULL) 451 return (error); 452 453 bcopy(buf, table->mbr, sizeof(table->mbr)); 454 for (index = NDOSPART - 1; index >= 0; index--) { 455 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 456 ent.dp_flag = p[0]; 457 ent.dp_shd = p[1]; 458 ent.dp_ssect = p[2]; 459 ent.dp_scyl = p[3]; 460 ent.dp_typ = p[4]; 461 ent.dp_ehd = p[5]; 462 ent.dp_esect = p[6]; 463 ent.dp_ecyl = p[7]; 464 ent.dp_start = le32dec(p + 8); 465 ent.dp_size = le32dec(p + 12); 466 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR) 467 continue; 468 if (ent.dp_start == 0 || ent.dp_size == 0) 469 continue; 470 sectors = ent.dp_esect & 0x3f; 471 if (sectors > basetable->gpt_sectors && 472 !basetable->gpt_fixgeom) { 473 g_part_geometry_heads(msize, sectors, &chs, &heads); 474 if (chs != 0) { 475 basetable->gpt_sectors = sectors; 476 basetable->gpt_heads = heads; 477 } 478 } 479 if (ent.dp_start < first) 480 first = ent.dp_start; 481 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable, 482 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1); 483 entry->ent = ent; 484 } 485 486 basetable->gpt_entries = NDOSPART; 487 basetable->gpt_first = basetable->gpt_sectors; 488 basetable->gpt_last = msize - 1; 489 490 if (first < basetable->gpt_first) 491 basetable->gpt_first = 1; 492 493 g_free(buf); 494 return (0); 495} 496 497static int 498g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry, 499 const char *attrib, unsigned int set) 500{ 501 struct g_part_entry *iter; 502 struct g_part_mbr_entry *entry; 503 int changed; 504 505 if (baseentry == NULL) 506 return (ENODEV); 507 if (strcasecmp(attrib, "active") != 0) 508 return (EINVAL); 509 510 /* Only one entry can have the active attribute. */ 511 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) { 512 if (iter->gpe_deleted) 513 continue; 514 changed = 0; 515 entry = (struct g_part_mbr_entry *)iter; 516 if (iter == baseentry) { 517 if (set && (entry->ent.dp_flag & 0x80) == 0) { 518 entry->ent.dp_flag |= 0x80; 519 changed = 1; 520 } else if (!set && (entry->ent.dp_flag & 0x80)) { 521 entry->ent.dp_flag &= ~0x80; 522 changed = 1; 523 } 524 } else { 525 if (set && (entry->ent.dp_flag & 0x80)) { 526 entry->ent.dp_flag &= ~0x80; 527 changed = 1; 528 } 529 } 530 if (changed && !iter->gpe_created) 531 iter->gpe_modified = 1; 532 } 533 return (0); 534} 535 536static const char * 537g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 538 char *buf, size_t bufsz) 539{ 540 struct g_part_mbr_entry *entry; 541 int i; 542 543 entry = (struct g_part_mbr_entry *)baseentry; 544 for (i = 0; 545 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 546 if (mbr_alias_match[i].typ == entry->ent.dp_typ) 547 return (g_part_alias_name(mbr_alias_match[i].alias)); 548 } 549 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ); 550 return (buf); 551} 552 553static int 554g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp) 555{ 556 struct g_part_entry *baseentry; 557 struct g_part_mbr_entry *entry; 558 struct g_part_mbr_table *table; 559 u_char *p; 560 int error, index; 561 562 table = (struct g_part_mbr_table *)basetable; 563 baseentry = LIST_FIRST(&basetable->gpt_entry); 564 for (index = 1; index <= basetable->gpt_entries; index++) { 565 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE; 566 entry = (baseentry != NULL && index == baseentry->gpe_index) 567 ? (struct g_part_mbr_entry *)baseentry : NULL; 568 if (entry != NULL && !baseentry->gpe_deleted) { 569 p[0] = entry->ent.dp_flag; 570 p[1] = entry->ent.dp_shd; 571 p[2] = entry->ent.dp_ssect; 572 p[3] = entry->ent.dp_scyl; 573 p[4] = entry->ent.dp_typ; 574 p[5] = entry->ent.dp_ehd; 575 p[6] = entry->ent.dp_esect; 576 p[7] = entry->ent.dp_ecyl; 577 le32enc(p + 8, entry->ent.dp_start); 578 le32enc(p + 12, entry->ent.dp_size); 579 } else 580 bzero(p, DOSPARTSIZE); 581 582 if (entry != NULL) 583 baseentry = LIST_NEXT(baseentry, gpe_entry); 584 } 585 586 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize); 587 return (error); 588} 589