g_part_mbr.c revision 222243
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: head/sys/geom/part/g_part_mbr.c 222243 2011-05-24 06:44:16Z 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/part/g_part.h> 46 47#include "g_part_if.h" 48 49FEATURE(geom_part_mbr, "GEOM partitioning class for MBR support"); 50 51#define MBRSIZE 512 52 53struct g_part_mbr_table { 54 struct g_part_table base; 55 u_char mbr[MBRSIZE]; 56}; 57 58struct g_part_mbr_entry { 59 struct g_part_entry base; 60 struct dos_partition ent; 61}; 62 63static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *, 64 struct g_part_parms *); 65static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *); 66static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *); 67static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *); 68static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *, 69 struct sbuf *, const char *); 70static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *); 71static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *, 72 struct g_part_parms *); 73static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *, 74 char *, size_t); 75static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *); 76static int g_part_mbr_read(struct g_part_table *, struct g_consumer *); 77static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *, 78 const char *, unsigned int); 79static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *, 80 char *, size_t); 81static int g_part_mbr_write(struct g_part_table *, struct g_consumer *); 82static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *, 83 struct g_part_parms *); 84 85static kobj_method_t g_part_mbr_methods[] = { 86 KOBJMETHOD(g_part_add, g_part_mbr_add), 87 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode), 88 KOBJMETHOD(g_part_create, g_part_mbr_create), 89 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy), 90 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf), 91 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto), 92 KOBJMETHOD(g_part_modify, g_part_mbr_modify), 93 KOBJMETHOD(g_part_resize, g_part_mbr_resize), 94 KOBJMETHOD(g_part_name, g_part_mbr_name), 95 KOBJMETHOD(g_part_probe, g_part_mbr_probe), 96 KOBJMETHOD(g_part_read, g_part_mbr_read), 97 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset), 98 KOBJMETHOD(g_part_type, g_part_mbr_type), 99 KOBJMETHOD(g_part_write, g_part_mbr_write), 100 { 0, 0 } 101}; 102 103static struct g_part_scheme g_part_mbr_scheme = { 104 "MBR", 105 g_part_mbr_methods, 106 sizeof(struct g_part_mbr_table), 107 .gps_entrysz = sizeof(struct g_part_mbr_entry), 108 .gps_minent = NDOSPART, 109 .gps_maxent = NDOSPART, 110 .gps_bootcodesz = MBRSIZE, 111}; 112G_PART_SCHEME_DECLARE(g_part_mbr); 113 114static struct g_part_mbr_alias { 115 u_char typ; 116 int alias; 117} mbr_alias_match[] = { 118 { DOSPTYP_386BSD, G_PART_ALIAS_FREEBSD }, 119 { DOSPTYP_EXT, G_PART_ALIAS_EBR }, 120 { DOSPTYP_NTFS, G_PART_ALIAS_MS_NTFS }, 121 { DOSPTYP_FAT32, G_PART_ALIAS_MS_FAT32 }, 122 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP }, 123 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA }, 124 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM }, 125 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID }, 126}; 127 128static int 129mbr_parse_type(const char *type, u_char *dp_typ) 130{ 131 const char *alias; 132 char *endp; 133 long lt; 134 int i; 135 136 if (type[0] == '!') { 137 lt = strtol(type + 1, &endp, 0); 138 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256) 139 return (EINVAL); 140 *dp_typ = (u_char)lt; 141 return (0); 142 } 143 for (i = 0; 144 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 145 alias = g_part_alias_name(mbr_alias_match[i].alias); 146 if (strcasecmp(type, alias) == 0) { 147 *dp_typ = mbr_alias_match[i].typ; 148 return (0); 149 } 150 } 151 return (EINVAL); 152} 153 154static int 155mbr_probe_bpb(u_char *bpb) 156{ 157 uint16_t secsz; 158 uint8_t clstsz; 159 160#define PO2(x) ((x & (x - 1)) == 0) 161 secsz = le16dec(bpb); 162 if (secsz < 512 || secsz > 4096 || !PO2(secsz)) 163 return (0); 164 clstsz = bpb[2]; 165 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz)) 166 return (0); 167#undef PO2 168 169 return (1); 170} 171 172static void 173mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp, 174 u_char *secp) 175{ 176 uint32_t cyl, hd, sec; 177 178 sec = lba % table->gpt_sectors + 1; 179 lba /= table->gpt_sectors; 180 hd = lba % table->gpt_heads; 181 lba /= table->gpt_heads; 182 cyl = lba; 183 if (cyl > 1023) 184 sec = hd = cyl = ~0; 185 186 *cylp = cyl & 0xff; 187 *hdp = hd & 0xff; 188 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 189} 190 191static int 192g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry, 193 struct g_part_parms *gpp) 194{ 195 struct g_part_mbr_entry *entry; 196 struct g_part_mbr_table *table; 197 uint32_t start, size, sectors; 198 199 if (gpp->gpp_parms & G_PART_PARM_LABEL) 200 return (EINVAL); 201 202 sectors = basetable->gpt_sectors; 203 204 entry = (struct g_part_mbr_entry *)baseentry; 205 table = (struct g_part_mbr_table *)basetable; 206 207 start = gpp->gpp_start; 208 size = gpp->gpp_size; 209 if (size < sectors) 210 return (EINVAL); 211 if (start % sectors) { 212 size = size - sectors + (start % sectors); 213 start = start - (start % sectors) + sectors; 214 } 215 if (size % sectors) 216 size = size - (size % sectors); 217 if (size < sectors) 218 return (EINVAL); 219 220 if (baseentry->gpe_deleted) 221 bzero(&entry->ent, sizeof(entry->ent)); 222 223 KASSERT(baseentry->gpe_start <= start, ("%s", __func__)); 224 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__)); 225 baseentry->gpe_start = start; 226 baseentry->gpe_end = start + size - 1; 227 entry->ent.dp_start = start; 228 entry->ent.dp_size = size; 229 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl, 230 &entry->ent.dp_shd, &entry->ent.dp_ssect); 231 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 232 &entry->ent.dp_ehd, &entry->ent.dp_esect); 233 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 234} 235 236static int 237g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp) 238{ 239 struct g_part_mbr_table *table; 240 size_t codesz; 241 242 codesz = DOSPARTOFF; 243 table = (struct g_part_mbr_table *)basetable; 244 bzero(table->mbr, codesz); 245 codesz = MIN(codesz, gpp->gpp_codesize); 246 if (codesz > 0) 247 bcopy(gpp->gpp_codeptr, table->mbr, codesz); 248 return (0); 249} 250 251static int 252g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp) 253{ 254 struct g_provider *pp; 255 struct g_part_mbr_table *table; 256 uint32_t msize; 257 258 pp = gpp->gpp_provider; 259 if (pp->sectorsize < MBRSIZE) 260 return (ENOSPC); 261 262 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX); 263 basetable->gpt_first = basetable->gpt_sectors; 264 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 265 266 table = (struct g_part_mbr_table *)basetable; 267 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC); 268 return (0); 269} 270 271static int 272g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp) 273{ 274 275 /* Wipe the first sector to clear the partitioning. */ 276 basetable->gpt_smhead |= 1; 277 return (0); 278} 279 280static void 281g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 282 struct sbuf *sb, const char *indent) 283{ 284 struct g_part_mbr_entry *entry; 285 286 entry = (struct g_part_mbr_entry *)baseentry; 287 if (indent == NULL) { 288 /* conftxt: libdisk compatibility */ 289 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ); 290 } else if (entry != NULL) { 291 /* confxml: partition entry information */ 292 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent, 293 entry->ent.dp_typ); 294 if (entry->ent.dp_flag & 0x80) 295 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent); 296 } else { 297 /* confxml: scheme information */ 298 } 299} 300 301static int 302g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry) 303{ 304 struct g_part_mbr_entry *entry; 305 306 /* Allow dumping to a FreeBSD partition only. */ 307 entry = (struct g_part_mbr_entry *)baseentry; 308 return ((entry->ent.dp_typ == DOSPTYP_386BSD) ? 1 : 0); 309} 310 311static int 312g_part_mbr_modify(struct g_part_table *basetable, 313 struct g_part_entry *baseentry, struct g_part_parms *gpp) 314{ 315 struct g_part_mbr_entry *entry; 316 317 if (gpp->gpp_parms & G_PART_PARM_LABEL) 318 return (EINVAL); 319 320 entry = (struct g_part_mbr_entry *)baseentry; 321 if (gpp->gpp_parms & G_PART_PARM_TYPE) 322 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 323 return (0); 324} 325 326static int 327g_part_mbr_resize(struct g_part_table *basetable, 328 struct g_part_entry *baseentry, struct g_part_parms *gpp) 329{ 330 struct g_part_mbr_entry *entry; 331 uint32_t size, sectors; 332 333 sectors = basetable->gpt_sectors; 334 size = gpp->gpp_size; 335 336 if (size < sectors) 337 return (EINVAL); 338 if (size % sectors) 339 size = size - (size % sectors); 340 if (size < sectors) 341 return (EINVAL); 342 343 entry = (struct g_part_mbr_entry *)baseentry; 344 baseentry->gpe_end = baseentry->gpe_start + size - 1; 345 entry->ent.dp_size = size; 346 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 347 &entry->ent.dp_ehd, &entry->ent.dp_esect); 348 return (0); 349} 350 351static const char * 352g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry, 353 char *buf, size_t bufsz) 354{ 355 356 snprintf(buf, bufsz, "s%d", baseentry->gpe_index); 357 return (buf); 358} 359 360static int 361g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp) 362{ 363 char psn[8]; 364 struct g_provider *pp; 365 u_char *buf, *p; 366 int error, index, res, sum; 367 uint16_t magic; 368 369 pp = cp->provider; 370 371 /* Sanity-check the provider. */ 372 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize) 373 return (ENOSPC); 374 if (pp->sectorsize > 4096) 375 return (ENXIO); 376 377 /* We don't nest under an MBR (see EBR instead). */ 378 error = g_getattr("PART::scheme", cp, &psn); 379 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0) 380 return (ELOOP); 381 382 /* Check that there's a MBR. */ 383 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 384 if (buf == NULL) 385 return (error); 386 387 /* We goto out on mismatch. */ 388 res = ENXIO; 389 390 magic = le16dec(buf + DOSMAGICOFFSET); 391 if (magic != DOSMAGIC) 392 goto out; 393 394 for (index = 0; index < NDOSPART; index++) { 395 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 396 if (p[0] != 0 && p[0] != 0x80) 397 goto out; 398 } 399 400 /* 401 * If the partition table does not consist of all zeroes, 402 * assume we have a MBR. If it's all zeroes, we could have 403 * a boot sector. For example, a boot sector that doesn't 404 * have boot code -- common on non-i386 hardware. In that 405 * case we check if we have a possible BPB. If so, then we 406 * assume we have a boot sector instead. 407 */ 408 sum = 0; 409 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++) 410 sum += buf[DOSPARTOFF + index]; 411 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b)) 412 res = G_PART_PROBE_PRI_NORM; 413 414 out: 415 g_free(buf); 416 return (res); 417} 418 419static int 420g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp) 421{ 422 struct dos_partition ent; 423 struct g_provider *pp; 424 struct g_part_mbr_table *table; 425 struct g_part_mbr_entry *entry; 426 u_char *buf, *p; 427 off_t chs, msize; 428 u_int sectors, heads; 429 int error, index; 430 431 pp = cp->provider; 432 table = (struct g_part_mbr_table *)basetable; 433 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX); 434 435 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 436 if (buf == NULL) 437 return (error); 438 439 bcopy(buf, table->mbr, sizeof(table->mbr)); 440 for (index = NDOSPART - 1; index >= 0; index--) { 441 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 442 ent.dp_flag = p[0]; 443 ent.dp_shd = p[1]; 444 ent.dp_ssect = p[2]; 445 ent.dp_scyl = p[3]; 446 ent.dp_typ = p[4]; 447 ent.dp_ehd = p[5]; 448 ent.dp_esect = p[6]; 449 ent.dp_ecyl = p[7]; 450 ent.dp_start = le32dec(p + 8); 451 ent.dp_size = le32dec(p + 12); 452 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR) 453 continue; 454 if (ent.dp_start == 0 || ent.dp_size == 0) 455 continue; 456 sectors = ent.dp_esect & 0x3f; 457 if (sectors > basetable->gpt_sectors && 458 !basetable->gpt_fixgeom) { 459 g_part_geometry_heads(msize, sectors, &chs, &heads); 460 if (chs != 0) { 461 basetable->gpt_sectors = sectors; 462 basetable->gpt_heads = heads; 463 } 464 } 465 466 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable, 467 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1); 468 entry->ent = ent; 469 } 470 471 basetable->gpt_entries = NDOSPART; 472 basetable->gpt_first = basetable->gpt_sectors; 473 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 474 475 g_free(buf); 476 return (0); 477} 478 479static int 480g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry, 481 const char *attrib, unsigned int set) 482{ 483 struct g_part_entry *iter; 484 struct g_part_mbr_entry *entry; 485 int changed; 486 487 if (strcasecmp(attrib, "active") != 0) 488 return (EINVAL); 489 490 /* Only one entry can have the active attribute. */ 491 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) { 492 if (iter->gpe_deleted) 493 continue; 494 changed = 0; 495 entry = (struct g_part_mbr_entry *)iter; 496 if (iter == baseentry) { 497 if (set && (entry->ent.dp_flag & 0x80) == 0) { 498 entry->ent.dp_flag |= 0x80; 499 changed = 1; 500 } else if (!set && (entry->ent.dp_flag & 0x80)) { 501 entry->ent.dp_flag &= ~0x80; 502 changed = 1; 503 } 504 } else { 505 if (set && (entry->ent.dp_flag & 0x80)) { 506 entry->ent.dp_flag &= ~0x80; 507 changed = 1; 508 } 509 } 510 if (changed && !iter->gpe_created) 511 iter->gpe_modified = 1; 512 } 513 return (0); 514} 515 516static const char * 517g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 518 char *buf, size_t bufsz) 519{ 520 struct g_part_mbr_entry *entry; 521 int i; 522 523 entry = (struct g_part_mbr_entry *)baseentry; 524 for (i = 0; 525 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 526 if (mbr_alias_match[i].typ == entry->ent.dp_typ) 527 return (g_part_alias_name(mbr_alias_match[i].alias)); 528 } 529 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ); 530 return (buf); 531} 532 533static int 534g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp) 535{ 536 struct g_part_entry *baseentry; 537 struct g_part_mbr_entry *entry; 538 struct g_part_mbr_table *table; 539 u_char *p; 540 int error, index; 541 542 table = (struct g_part_mbr_table *)basetable; 543 baseentry = LIST_FIRST(&basetable->gpt_entry); 544 for (index = 1; index <= basetable->gpt_entries; index++) { 545 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE; 546 entry = (baseentry != NULL && index == baseentry->gpe_index) 547 ? (struct g_part_mbr_entry *)baseentry : NULL; 548 if (entry != NULL && !baseentry->gpe_deleted) { 549 p[0] = entry->ent.dp_flag; 550 p[1] = entry->ent.dp_shd; 551 p[2] = entry->ent.dp_ssect; 552 p[3] = entry->ent.dp_scyl; 553 p[4] = entry->ent.dp_typ; 554 p[5] = entry->ent.dp_ehd; 555 p[6] = entry->ent.dp_esect; 556 p[7] = entry->ent.dp_ecyl; 557 le32enc(p + 8, entry->ent.dp_start); 558 le32enc(p + 12, entry->ent.dp_size); 559 } else 560 bzero(p, DOSPARTSIZE); 561 562 if (entry != NULL) 563 baseentry = LIST_NEXT(baseentry, gpe_entry); 564 } 565 566 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize); 567 return (error); 568} 569