g_part_mbr.c revision 209536
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 209536 2010-06-26 13:20:40Z rpaulo $"); 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 <geom/geom.h> 44#include <geom/part/g_part.h> 45 46#include "g_part_if.h" 47 48#define MBRSIZE 512 49 50struct g_part_mbr_table { 51 struct g_part_table base; 52 u_char mbr[MBRSIZE]; 53}; 54 55struct g_part_mbr_entry { 56 struct g_part_entry base; 57 struct dos_partition ent; 58}; 59 60static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *, 61 struct g_part_parms *); 62static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *); 63static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *); 64static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *); 65static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *, 66 struct sbuf *, const char *); 67static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *); 68static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *, 69 struct g_part_parms *); 70static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *, 71 char *, size_t); 72static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *); 73static int g_part_mbr_read(struct g_part_table *, struct g_consumer *); 74static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *, 75 const char *, unsigned int); 76static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *, 77 char *, size_t); 78static int g_part_mbr_write(struct g_part_table *, struct g_consumer *); 79static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *, 80 struct g_part_parms *); 81 82static kobj_method_t g_part_mbr_methods[] = { 83 KOBJMETHOD(g_part_add, g_part_mbr_add), 84 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode), 85 KOBJMETHOD(g_part_create, g_part_mbr_create), 86 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy), 87 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf), 88 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto), 89 KOBJMETHOD(g_part_modify, g_part_mbr_modify), 90 KOBJMETHOD(g_part_resize, g_part_mbr_resize), 91 KOBJMETHOD(g_part_name, g_part_mbr_name), 92 KOBJMETHOD(g_part_probe, g_part_mbr_probe), 93 KOBJMETHOD(g_part_read, g_part_mbr_read), 94 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset), 95 KOBJMETHOD(g_part_type, g_part_mbr_type), 96 KOBJMETHOD(g_part_write, g_part_mbr_write), 97 { 0, 0 } 98}; 99 100static struct g_part_scheme g_part_mbr_scheme = { 101 "MBR", 102 g_part_mbr_methods, 103 sizeof(struct g_part_mbr_table), 104 .gps_entrysz = sizeof(struct g_part_mbr_entry), 105 .gps_minent = NDOSPART, 106 .gps_maxent = NDOSPART, 107 .gps_bootcodesz = MBRSIZE, 108}; 109G_PART_SCHEME_DECLARE(g_part_mbr); 110 111static int 112mbr_parse_type(const char *type, u_char *dp_typ) 113{ 114 const char *alias; 115 char *endp; 116 long lt; 117 118 if (type[0] == '!') { 119 lt = strtol(type + 1, &endp, 0); 120 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256) 121 return (EINVAL); 122 *dp_typ = (u_char)lt; 123 return (0); 124 } 125 alias = g_part_alias_name(G_PART_ALIAS_FREEBSD); 126 if (!strcasecmp(type, alias)) { 127 *dp_typ = DOSPTYP_386BSD; 128 return (0); 129 } 130 alias = g_part_alias_name(G_PART_ALIAS_MS_NTFS); 131 if (!strcasecmp(type, alias)) { 132 *dp_typ = DOSPTYP_NTFS; 133 return (0); 134 } 135 return (EINVAL); 136} 137 138static int 139mbr_probe_bpb(u_char *bpb) 140{ 141 uint16_t secsz; 142 uint8_t clstsz; 143 144#define PO2(x) ((x & (x - 1)) == 0) 145 secsz = le16dec(bpb); 146 if (secsz < 512 || secsz > 4096 || !PO2(secsz)) 147 return (0); 148 clstsz = bpb[2]; 149 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz)) 150 return (0); 151#undef PO2 152 153 return (1); 154} 155 156static void 157mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp, 158 u_char *secp) 159{ 160 uint32_t cyl, hd, sec; 161 162 sec = lba % table->gpt_sectors + 1; 163 lba /= table->gpt_sectors; 164 hd = lba % table->gpt_heads; 165 lba /= table->gpt_heads; 166 cyl = lba; 167 if (cyl > 1023) 168 sec = hd = cyl = ~0; 169 170 *cylp = cyl & 0xff; 171 *hdp = hd & 0xff; 172 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 173} 174 175static int 176g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry, 177 struct g_part_parms *gpp) 178{ 179 struct g_part_mbr_entry *entry; 180 struct g_part_mbr_table *table; 181 uint32_t start, size, sectors; 182 183 if (gpp->gpp_parms & G_PART_PARM_LABEL) 184 return (EINVAL); 185 186 sectors = basetable->gpt_sectors; 187 188 entry = (struct g_part_mbr_entry *)baseentry; 189 table = (struct g_part_mbr_table *)basetable; 190 191 start = gpp->gpp_start; 192 size = gpp->gpp_size; 193 if (size < sectors) 194 return (EINVAL); 195 if (start % sectors) { 196 size = size - sectors + (start % sectors); 197 start = start - (start % sectors) + sectors; 198 } 199 if (size % sectors) 200 size = size - (size % sectors); 201 if (size < sectors) 202 return (EINVAL); 203 204 if (baseentry->gpe_deleted) 205 bzero(&entry->ent, sizeof(entry->ent)); 206 207 KASSERT(baseentry->gpe_start <= start, (__func__)); 208 KASSERT(baseentry->gpe_end >= start + size - 1, (__func__)); 209 baseentry->gpe_start = start; 210 baseentry->gpe_end = start + size - 1; 211 entry->ent.dp_start = start; 212 entry->ent.dp_size = size; 213 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl, 214 &entry->ent.dp_shd, &entry->ent.dp_ssect); 215 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 216 &entry->ent.dp_ehd, &entry->ent.dp_esect); 217 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 218} 219 220static int 221g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp) 222{ 223 struct g_part_mbr_table *table; 224 size_t codesz; 225 226 codesz = DOSPARTOFF; 227 table = (struct g_part_mbr_table *)basetable; 228 bzero(table->mbr, codesz); 229 codesz = MIN(codesz, gpp->gpp_codesize); 230 if (codesz > 0) 231 bcopy(gpp->gpp_codeptr, table->mbr, codesz); 232 return (0); 233} 234 235static int 236g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp) 237{ 238 struct g_consumer *cp; 239 struct g_provider *pp; 240 struct g_part_mbr_table *table; 241 uint32_t msize; 242 243 pp = gpp->gpp_provider; 244 cp = LIST_FIRST(&pp->consumers); 245 246 if (pp->sectorsize < MBRSIZE) 247 return (ENOSPC); 248 249 msize = MIN(pp->mediasize / pp->sectorsize, 0xffffffff); 250 basetable->gpt_first = basetable->gpt_sectors; 251 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 252 253 table = (struct g_part_mbr_table *)basetable; 254 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC); 255 return (0); 256} 257 258static int 259g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp) 260{ 261 262 /* Wipe the first sector to clear the partitioning. */ 263 basetable->gpt_smhead |= 1; 264 return (0); 265} 266 267static void 268g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 269 struct sbuf *sb, const char *indent) 270{ 271 struct g_part_mbr_entry *entry; 272 273 entry = (struct g_part_mbr_entry *)baseentry; 274 if (indent == NULL) { 275 /* conftxt: libdisk compatibility */ 276 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ); 277 } else if (entry != NULL) { 278 /* confxml: partition entry information */ 279 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent, 280 entry->ent.dp_typ); 281 if (entry->ent.dp_flag & 0x80) 282 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent); 283 } else { 284 /* confxml: scheme information */ 285 } 286} 287 288static int 289g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry) 290{ 291 struct g_part_mbr_entry *entry; 292 293 /* Allow dumping to a FreeBSD partition only. */ 294 entry = (struct g_part_mbr_entry *)baseentry; 295 return ((entry->ent.dp_typ == DOSPTYP_386BSD) ? 1 : 0); 296} 297 298static int 299g_part_mbr_modify(struct g_part_table *basetable, 300 struct g_part_entry *baseentry, struct g_part_parms *gpp) 301{ 302 struct g_part_mbr_entry *entry; 303 304 if (gpp->gpp_parms & G_PART_PARM_LABEL) 305 return (EINVAL); 306 307 entry = (struct g_part_mbr_entry *)baseentry; 308 if (gpp->gpp_parms & G_PART_PARM_TYPE) 309 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 310 return (0); 311} 312 313static int 314g_part_mbr_resize(struct g_part_table *basetable, 315 struct g_part_entry *baseentry, struct g_part_parms *gpp) 316{ 317 struct g_part_mbr_entry *entry; 318 uint32_t size, sectors; 319 320 sectors = basetable->gpt_sectors; 321 size = gpp->gpp_size; 322 323 if (size < sectors) 324 return (EINVAL); 325 if (size % sectors) 326 size = size - (size % sectors); 327 if (size < sectors) 328 return (EINVAL); 329 330 entry = (struct g_part_mbr_entry *)baseentry; 331 baseentry->gpe_end = baseentry->gpe_start + size - 1; 332 entry->ent.dp_size = size; 333 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 334 &entry->ent.dp_ehd, &entry->ent.dp_esect); 335 return (0); 336} 337 338static const char * 339g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry, 340 char *buf, size_t bufsz) 341{ 342 343 snprintf(buf, bufsz, "s%d", baseentry->gpe_index); 344 return (buf); 345} 346 347static int 348g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp) 349{ 350 char psn[8]; 351 struct g_provider *pp; 352 u_char *buf, *p; 353 int error, index, res, sum; 354 uint16_t magic; 355 356 pp = cp->provider; 357 358 /* Sanity-check the provider. */ 359 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize) 360 return (ENOSPC); 361 if (pp->sectorsize > 4096) 362 return (ENXIO); 363 364 /* We don't nest under an MBR (see EBR instead). */ 365 error = g_getattr("PART::scheme", cp, &psn); 366 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0) 367 return (ELOOP); 368 369 /* Check that there's a MBR. */ 370 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 371 if (buf == NULL) 372 return (error); 373 374 /* We goto out on mismatch. */ 375 res = ENXIO; 376 377 magic = le16dec(buf + DOSMAGICOFFSET); 378 if (magic != DOSMAGIC) 379 goto out; 380 381 for (index = 0; index < NDOSPART; index++) { 382 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 383 if (p[0] != 0 && p[0] != 0x80) 384 goto out; 385 } 386 387 /* 388 * If the partition table does not consist of all zeroes, 389 * assume we have a MBR. If it's all zeroes, we could have 390 * a boot sector. For example, a boot sector that doesn't 391 * have boot code -- common on non-i386 hardware. In that 392 * case we check if we have a possible BPB. If so, then we 393 * assume we have a boot sector instead. 394 */ 395 sum = 0; 396 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++) 397 sum += buf[DOSPARTOFF + index]; 398 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b)) 399 res = G_PART_PROBE_PRI_NORM; 400 401 out: 402 g_free(buf); 403 return (res); 404} 405 406static int 407g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp) 408{ 409 struct dos_partition ent; 410 struct g_provider *pp; 411 struct g_part_mbr_table *table; 412 struct g_part_mbr_entry *entry; 413 u_char *buf, *p; 414 off_t chs, msize; 415 u_int sectors, heads; 416 int error, index; 417 418 pp = cp->provider; 419 table = (struct g_part_mbr_table *)basetable; 420 msize = pp->mediasize / pp->sectorsize; 421 422 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 423 if (buf == NULL) 424 return (error); 425 426 bcopy(buf, table->mbr, sizeof(table->mbr)); 427 for (index = NDOSPART - 1; index >= 0; index--) { 428 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 429 ent.dp_flag = p[0]; 430 ent.dp_shd = p[1]; 431 ent.dp_ssect = p[2]; 432 ent.dp_scyl = p[3]; 433 ent.dp_typ = p[4]; 434 ent.dp_ehd = p[5]; 435 ent.dp_esect = p[6]; 436 ent.dp_ecyl = p[7]; 437 ent.dp_start = le32dec(p + 8); 438 ent.dp_size = le32dec(p + 12); 439 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR) 440 continue; 441 if (ent.dp_start == 0 || ent.dp_size == 0) 442 continue; 443 sectors = ent.dp_esect & 0x3f; 444 if (sectors > basetable->gpt_sectors && 445 !basetable->gpt_fixgeom) { 446 g_part_geometry_heads(msize, sectors, &chs, &heads); 447 if (chs != 0) { 448 basetable->gpt_sectors = sectors; 449 basetable->gpt_heads = heads; 450 } 451 } 452 if ((ent.dp_start % basetable->gpt_sectors) != 0) 453 printf("GEOM: %s: partition %d does not start on a " 454 "track boundary.\n", pp->name, index + 1); 455 if ((ent.dp_size % basetable->gpt_sectors) != 0) 456 printf("GEOM: %s: partition %d does not end on a " 457 "track boundary.\n", pp->name, index + 1); 458 459 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable, 460 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1); 461 entry->ent = ent; 462 } 463 464 basetable->gpt_entries = NDOSPART; 465 basetable->gpt_first = basetable->gpt_sectors; 466 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 467 468 return (0); 469} 470 471static int 472g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry, 473 const char *attrib, unsigned int set) 474{ 475 struct g_part_entry *iter; 476 struct g_part_mbr_entry *entry; 477 int changed; 478 479 if (strcasecmp(attrib, "active") != 0) 480 return (EINVAL); 481 482 /* Only one entry can have the active attribute. */ 483 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) { 484 if (iter->gpe_deleted) 485 continue; 486 changed = 0; 487 entry = (struct g_part_mbr_entry *)iter; 488 if (iter == baseentry) { 489 if (set && (entry->ent.dp_flag & 0x80) == 0) { 490 entry->ent.dp_flag |= 0x80; 491 changed = 1; 492 } else if (!set && (entry->ent.dp_flag & 0x80)) { 493 entry->ent.dp_flag &= ~0x80; 494 changed = 1; 495 } 496 } else { 497 if (set && (entry->ent.dp_flag & 0x80)) { 498 entry->ent.dp_flag &= ~0x80; 499 changed = 1; 500 } 501 } 502 if (changed && !iter->gpe_created) 503 iter->gpe_modified = 1; 504 } 505 return (0); 506} 507 508static const char * 509g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 510 char *buf, size_t bufsz) 511{ 512 struct g_part_mbr_entry *entry; 513 int type; 514 515 entry = (struct g_part_mbr_entry *)baseentry; 516 type = entry->ent.dp_typ; 517 switch (type) { 518 case DOSPTYP_386BSD: 519 return (g_part_alias_name(G_PART_ALIAS_FREEBSD)); 520 case DOSPTYP_NTFS: 521 return (g_part_alias_name(G_PART_ALIAS_MS_NTFS)); 522 default: 523 snprintf(buf, bufsz, "!%d", type); 524 } 525 return (buf); 526} 527 528static int 529g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp) 530{ 531 struct g_part_entry *baseentry; 532 struct g_part_mbr_entry *entry; 533 struct g_part_mbr_table *table; 534 u_char *p; 535 int error, index; 536 537 table = (struct g_part_mbr_table *)basetable; 538 baseentry = LIST_FIRST(&basetable->gpt_entry); 539 for (index = 1; index <= basetable->gpt_entries; index++) { 540 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE; 541 entry = (baseentry != NULL && index == baseentry->gpe_index) 542 ? (struct g_part_mbr_entry *)baseentry : NULL; 543 if (entry != NULL && !baseentry->gpe_deleted) { 544 p[0] = entry->ent.dp_flag; 545 p[1] = entry->ent.dp_shd; 546 p[2] = entry->ent.dp_ssect; 547 p[3] = entry->ent.dp_scyl; 548 p[4] = entry->ent.dp_typ; 549 p[5] = entry->ent.dp_ehd; 550 p[6] = entry->ent.dp_esect; 551 p[7] = entry->ent.dp_ecyl; 552 le32enc(p + 8, entry->ent.dp_start); 553 le32enc(p + 12, entry->ent.dp_size); 554 } else 555 bzero(p, DOSPARTSIZE); 556 557 if (entry != NULL) 558 baseentry = LIST_NEXT(baseentry, gpe_entry); 559 } 560 561 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize); 562 return (error); 563} 564